Supragingival cleaning 3 times a week. The microbiological effects in moderately deep pockets. It is generally believed that supragingival plaque control has little effect on the subgingival microflora of deep periodontal pockets. However, this may not be true for moderately deep pockets (4-5 mm), which may represent a pathological state between gingivitis and marginal periodontitis. In 6 patients with poor oral hygiene and severe gingival inflammation, 4 matched sites (1 in each quadrant), were chosen which demonstrated at least 20% spirochetes and 15% black-pigmented Gram-negative bacilli. During the first 12 weeks (phase 1), supragingival calculus was removed from the right half of the mouth and then the teeth were professionally cleaned three times a week. At the beginning of phase 2, supragingival calculus was also removed from the left quadrants and the entire mouth was subjected to the same protocol used in phase 1. At no time did patients receive oral hygiene instructions. Clinical parameters were assessed and microbiological samples were taken at 3-week intervals. Samples were submitted to darkfield microscopy and anaerobic culturing. Analysis by multiple linear regression and the Wilcoxon signed-rank test revealed significant changes in the composition of the subgingival microbiota at cleaned sites. While Gram-positive organisms increased proportionally, a number of putative periodontal pathogens, such as P. gingivalis and spirochetes decreased.


An aromatase-associated cytoplasmic inclusion, the "stigmoid body," in the rat brain: I. Distribution in the forebrain. An aromatase-containing neural system was examined in the rat forebrain, using a polyclonal antibody against aromatase-associated human placental antigen X-P2 (hPAX-P2). Numerous dot-like structures, which we have called stigmoid bodies, were immunostained in the preoptico-hypothalamic region, the bed nucleus of the stria terminalis, the medial amygdala, the arcuate nucleus, the subfornical organ, and the area extending from the hypothalamic area to the central gray through the medial forebrain bundle and the periventricular fiber system of the posterior diencephalon. The stigmoid bodies were always found as inclusions in the neuronal cytoplasm. Their diameter was usually 1-3 microns, but exceptionally large forms, over 3 microns, were found in some brain regions, including the area extending from the median preoptic nucleus surrounding the organosum vasculosum laminae terminalis to the anterior medial preoptic nucleus, the periventricular nucleus of the preoptic area, and some parts of the medial preoptic nucleus. Most of these nuclei show sexual dimorphism. The distribution pattern of the hPAX-P2 immunoreactive stigmoid bodies agreed well with that of aromatase activity previously reported in many biochemical studies. Brain regions where the stigmoid bodies were prominent largely coincide with steroid binding locations common to both androgen and estrogen, or regions where both sex steroid receptors are present. Although it still remains to be determined whether aromatase is localized within these stigmoid bodies, it appears likely that they are closely associated with the function of sex steroids at their target sites in the brain.


A comparison of glycogen phosphorylase a and cytochrome oxidase histochemical staining in rat brain. The utility of metabolic markers that index functional neuronal circuits is widely appreciated. The present study asks whether patterns of the metabolic enzyme, active glycogen phosphorylase, parallel those of the neuronal marker, cytochrome oxidase. Fresh frozen rat brain sections (30 microns) were processed for either active glycogen phosphorylase or cytochrome oxidase at each of ten levels of the neuraxis. Although these metabolic markers predominate in different cellular compartments--glycogen phosphorylase in the astrocytic compartment and cytochrome oxidase in the neuronal compartment--the patterns of high, moderate, and low levels of activity for both enzymes were generally parallel. These similarities extended to detailed patterns of heterogeneous staining within structures, in particular, to laminated and modular distribution within cerebral and cerebellar cortical structures. The modular distribution was evident in barrel structures in the cerebral cortex and in parasagittal compartments in the vermis of the cerebellum. Conspicuous differences between the two patterns occurred in white matter, in subcortical grey matter regions such as the nucleus accumbens, diagonal band, amygdala, and globus pallidus, and in the superior olivary nuclei of the brainstem as well as in nonneural structures such as the choroid plexus and ependyma. Discrete patchiness was characteristic of active glycogen phosphorylase distribution in the limbic neuropil of the dentate gyrus and entorhinal cortex. The strong parallels between active glycogen phosphorylase and cytochrome oxidase distribution support the view that glycogen phosphorylase, despite its glial localization, can reflect neuronal metabolic demands.


Eccrine porocarcinoma of the face.

Eccrine porocarcinoma of the face. Eccrine porocarcinoma is a rare tumor of the skin. We report a case on the chin that was successfully treated with Mohs surgery. In our review of the world's literature 105 cases were compiled. The tumor most often occurs in the elderly and affects men more frequently than women. It may develop from a preexisting benign poroma and may also appear as a verrucous or nodular, ulcerative growth. Approximately 50% of the tumors occur on the lower extremities; the leg is the most common site. Microscopically the tumor demonstrates both intraepidermal and dermal invasion and is capable of forming satellite lesions and in-transit metastases when lymphatic vessels are invaded. The local recurrence and regional metastatic rates are both approximately 20%. Distant metastasis occurs in 12% of cases. The mortality rate is more than 65% when regional nodes are involved.


Human papillomavirus in an epidermoid cyst of the sole in a non-Japanese patient. Several patients with an epidermoid cyst of the sole have recently been described in Japan. In these cases human papillomavirus was found in the wall and in the content of the cyst. We report the first documented case outside of Japan in which human papillomavirus has been demonstrated in an epidermoid cyst of the sole.


Thymostimulin administration modulates polymorph metabolic pathway in patients with chronic obstructive pulmonary disease. Several studies outline the imbalance of phagocyte functions in chronic obstructive pulmonary disease (COPD). In this regard, here, we have assessed either monocyte- and polymorphonuclear cell (PMN)-mediated chemotactic, phagocytic and killing capacities or PMN-triggered metabolic pathway in a group of COPD patients before and at different times after thymostimulin administration. Before therapy, an increase of O2-generation and a decrease of myeloperoxidase release were found in these individuals when compared to controls. Moreover, a reduction of either PMN-mediated chemotaxis and killing or monocyte chemotactic capacities was observed. By contrast, no differences were seen in terms of beta-glucuronidase release, monocyte-mediated killing and PMN or monocyte phagocytic function. During a one-year monitoring following immunotherapy, O2- production and myeloperoxidase activity fell within normal values, while phagocyte functional capacities were unaffected by such a treatment. Furthermore, COPD subjects exhibited a significant improvement of their clinical status as assessed during a one-year followup. All together, these findings suggest a potential role for thymostimulin in the treatment of COPD patients.


Mechanism of action of maternal serum on the interleukin2 receptor expression. Neoplastic Jurkat cells were submitted to a PHA stimulation test after a preincubation in maternal or nulliparous serum (10% dilution). The Il2R expression was significantly downregulated among maternal serum treated cells. Retroplacental serum was significantly more inhibitive than peripheral maternal serum (P less than 0.01). The maternal IgG fractions and mostly the retroplacental IgG fraction proved to contain a factor mainly responsible for the Il2R expression inhibitive property. The molecular mechanism of this phenomenon was further studied. It was shown that H7 (acting as a protein kinase inhibitor) could not influence the Il2R modulation. E.G.T.A., a calcium chelator, was not able to interfere with the inhibitive influence of maternal serum. It was suggested that the maternal serum mediated inhibition of the IL2R expression is not influenced by the hydrolysis of membrane bound phosphatidyl inositol. In contrast, pertussis toxin markedly enhanced, in a dose dependent way, the suppressive influence of maternal serum as compared to nulliparous serum. At low concentrations, pertussis toxin lost its stimulating property and retained its ability to ADP ribosylate the alpha subunit of G proteins inducing a release of adenylcyclase mediating cAMP synthesis. This mechanism has been further studied by the addition of dbc AMP or dbc GMP to Jurkat cells preparations stimulated by PHA. dbc AMP, in a dose-related way, induced a downregulation of the IL2R expression of stimulated neoplastic cells preincubated in nulliparous or maternal serum. dbc GMP did not influence the IL2R expression in the same experimental conditions. The maternal serum mediated cells showed the most pronounced IL2R inhibition. Finally, it was shown that the cAMP synthesis by PHA stimulated Jurkat cells was upregulated in a dose dependent way, after a previous cellular incubation in progressive concentrations of maternal serum. In contrast, among nulliparous serum pretreated cells, cAMP synthesis remained significantly lower, after a lectin stimulation, as compared to the cAMP production derived from retroplacental serum treated and stimulated cells. Taken together, these experiments suggest that the maternal serum dependent suppression of the IL2R expression is related to a protein G stimulation followed by an enhanced cAMP synthesis.


Interaction between (-)naloxone and morphine in modifying superoxide generation from human granulocytes. The effect of the opioid agonist morphine and of the (-) and (+) stereoisomers of the antagonist naloxone were studied on superoxide generation from human granulocytes. Morphine or naloxone had no effect on basal or phorbol 12-myristate 13-acetate (PMA)-stimulated superoxide generation. Combined equimolar (-)naloxone and morphine concentrations (0.1 pM-0.1 microM) inhibited PMA-stimulated superoxide generation, while combined (+)naloxone and morphine had no effect. The stereospecific effect of naloxone suggests the involvement of opioid receptors. Thus, inhibition of superoxide generation by combined (-)naloxone and morphine could result from the unmasking of non opioid effects of morphine. It is suggested that the opioid control of oxidative metabolism in human granulocytes could involve multiple receptors mediating opposite effects.


Inhibition of the neutrophil NADPH oxidase by folic acid and antagonists of the folic acid metabolism. The influence of folic acid and several antagonists of the folic acid metabolism on neutrophil superoxide generation was investigated with the cytochrome c reduction assay. The compounds were found to be partial competitive inhibitors of the NADPH oxidase, their activity apparently increasing with larger substituents at the 10 position. There is evidence that compounds with a 4-oxo substituent are taken up more slowly by neutrophils than those with a 4-amino functionality. Scavenging properties could be excluded from control measurements with the xanthine/xanthine oxidase assay.


Contrasting effects of THC on adult murine lymph node and spleen cell populations stimulated with mitogen or anti-CD3 antibody. Marijuana, and specifically its psychoactive component, THC, can up or down regulate lymphocyte proliferation in murine spleen cells depending in part on the method used to stimulate the cells. This study identifies a difference in THC induced disregulation using cells derived from two different secondary lymphoid organs, the spleen and the lymph node. It was found that THC treatment of mitogen (concanavalin A or phytohemagglutinin) stimulated cells derived from either organ resulted in suppression of the proliferative response. In contrast, spleen cells stimulated with anti-CD3 antibody and treated with low doses of THC displayed an enhanced proliferation whereas the response in lymph nodes did not change. The cell type involved with this THC immunoenhancement in spleen cells was found to be the Ly2 cell. Further differences in the THC modulation of Ly2 spleen cells as compared to lymph node cells were noted following stimulation with PHA. Proliferation of Ly2 cells of splenic origin was inhibited with low doses of THC whereas the Ly2 cells of lymph node origin were more resistant to this drug induced suppression. This study, therefore, demonstrates differences in the immunomodulatory capability of THC dependent upon the organ source of the lymphocytes.


Rapid inactivation of infectious pathogens by chlorhexidine-coated gloves. Gloves containing chlorhexidine gluconate in an instant-release matrix on their inner surface (CHG gloves) were tested to determine their ability to rapidly inactivate infectious pathogens that may permeate or leak through the latex surface. CHG gloves were exposed for 1 to 10 minutes to blood or media containing infectious pathogens (e.g., bacteria, fungi, parasites, and viruses) as well as to lymphocytes and macrophages that are known to be the primary carriers of human immunodeficiency virus (HIV). Inactivation of pathogens was determined either by in vitro assay or in vivo infectivity. Stressed control and CHG glove fingers were submerged in a viral pool (retrovirus or bacteriophage) and after a set time, the glove interiors were checked for presence of permeated virions. CHG gloves rapidly inactivate all the pathogens tested including retrovirus and hepatitis B virus (90% to 100%). In the stressed glove fingers, live virus was detected in 26% of the control group but not in any of the CHG group. The use of CHG gloves may reduce the risk of exposure to infectious fluid-borne pathogens should the integrity of the latex barrier be compromised by overt failure or by permeation of viruses. Rapid destruction of lymphocytes and macrophages may facilitate inactivation of HIV associated with these cells. Tests have shown that CHG coating does not alter physical properties of the glove, and, furthermore, CHG gloves do not show potential for dermal irritation or sensitization.


Investigation of an outbreak of methicillin-resistant Staphylococcus aureus in patients with skin disease using DNA restriction patterns. To investigate an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) among patients using chromosomal typing of the isolates. Comparison of epidemiological and clinical data to endonuclease restriction fragmentation analysis (RFA) of the MRSA isolates associated with an outbreak. Total DNA from the MRSA isolates was restricted with HINDIII and HAEIII for typing. Tertiary care academic medical center. An epidemiological investigation of an outbreak of MRSA among patients in private rooms was evaluated by routine infection control methods. The MRSA isolates from blood cultures of 7 patients and the nares of a nurse were collected during the outbreak. MRSA isolates from 23 patients not associated with the outbreak also were collected. The total DNA of the MRSA isolates were restricted with HINDIII and HAEIII and electrophoresed on 0.6% agarose gels. MRSA from 4 of the 7 bacteremic patients and the nurse on the outbreak unit had the same endonuclease restriction pattern. The patients were linked in that they were compromised by severe psoriasis or skin ulcers, were on the unit during the same period, and had oatmeal baths in a common bathtub. Of 50 staff members screened, the nurse was the only person detected as colonized by the strain. The other 3 patients on the unit as well as the 23 patients in other locations not associated with the outbreak had MRSA isolates with different RFA patterns. The use of the bathtub was discontinued and further transmission of MRSA was stopped. A comparison of the relatedness of MRSA by RFA demonstrated the uniqueness of the epidemiologically linked isolates and the utility of the RFA technique in the performance of routine infection control investigations.


Quantitative analysis of renin gene expression in extrarenal tissues by polymerase chain reaction method. To evaluate the significance of locally synthesized renin in the pathogenesis of hypertension, we investigated modulation of the renin gene expression in extrarenal tissues. Expression levels of renin messenger (m)RNA in various tissues were determined in the genetically hypertensive rats and their control strains. Effects of salt, captopril and clonidine upon renin gene expression were also investigated. Due to the very low expression level of renin mRNA in extrarenal tissues, a competitive polymerase chain reaction method of assessment was applied. Total RNA from various tissues combined with a synthetic deletion-mutated renin RNA were reverse-transcribed and the resultant complementary DNA mixtures were amplified in one reaction in which the same primers were used. Expression levels of the renin mRNA in various parts of the central nervous system of 4-week-old spontaneously hypertensive rats were approximately twofold higher than those of age-matched Wistar-Kyoto rats and expression levels in the brain were positively modulated by the administration of either captopril or clonidine. The importance of the brain renin angiotensin system in the pathogenesis of hypertension in spontaneously hypertensive rats was strongly suggested.


In vivo left ventricular anatomy in rats with two-kidney, one clip and one-kidney, one clip renovascular hypertension. To evaluate differences in left ventricular structural changes related to different hemodynamic patterns. One-kidney, one clip (1K1C; volume-dependent hypertension) rats were two-kidney, one clip (2K1C; high-resistance hypertension) to determine whether these two types of Goldblatt rats showed different types of left ventricular adaptation. M-mode echocardiography was used to study 28 2K1C and 19 1K1C Wistar rats 8 weeks after surgery and 55 age-matched control animals. Systolic blood pressure was equally high in the two models; the 1K1C rats had a larger left ventricular chamber and normal plasma renin activity (PRA), whereas in the 2K1C rats PRA was increased and the left ventricular chamber was normal. The atrial natriuretic factor was significantly increased only in the 2K1C rats and was related to PRA. The left ventricular mass index was increased in both models, but more in the 1K1C than the 2K1C rats. In both models the degree of left ventricular hypertrophy was associated with the interacting effects of the hemodynamic component superimposed on the primary hemodynamic pattern (i.e. blood pressure as an expression of pressure overload in the primarily volume-dependent 1K1C rats and the left ventricular chamber size as an expression of volume overload in the high-resistance 2K1C rats). The interaction between pressure and volume increased the left ventricular wall thickness in both models, with additional chamber enlargement in the 1K1C rats. In these rats, the increase in left ventricular mass was more pronounced due to the greater volume load on the heart.


Na(+)-K+ pump and Na(+)-K+ co-transport in cultured vascular smooth muscle cells from spontaneously hypertensive and normotensive rats: baseline activity and regulation. This paper examines the hypothesis that aberrations in vascular smooth muscle univalent ion transport systems play an important role in the pathogenesis of hypertension. Baseline Na(+)-K+ pump and Na(+)-K(+)-2Cl- co-transport activities and the regulation of these ion transport systems by angiotensin II and second messenger molecules have been studied in cultured aortic smooth muscle cells (VSMC) from normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). Ion transport was studied using isotopic univalent cations (86Rb and 22Na). Baseline Na(+)-K+ pump activity was comparable between SHR- and WKY-derived VSMC. Baseline Na(+)-K(+)-2Cl- and K(+)-Cl- co-transport activity as well as K+ leakage were significantly greater in SHR VSMC. Baseline Na(+)-K(+)-2Cl- co-transport was sensitive to inhibition by forskolin and ethyleneglycol-bis-(beta-amino ethylester)-N,N,N',N'-tetraacetic acid, whereas cyclic guanosine monophosphate and phorbol 12-myristate, 13-acetate had no effect. Angiotensin II-stimulated Na(+)-K(+)-2Cl- co-transport activity did not differ between WKY and SHR VSMC. Angiotensin II increased Na(+)-K(+)-pump activity to a significantly greater extent in SHR VSMC. The stimulatory effect of angiotensin II upon Na(+)-K+ pump activity was reduced under Na(+)-free buffer conditions and in the presence of the Na(+)-H+ exchange inhibitor, ethylisopropyl amiloride. Na(+)-K+ pump activity was also stimulated by the protein kinase C activator, phorbol 12-myristate, 13-acetate, and this was completely inhibited under Na(+)-free buffer conditions. SHR VSMC exhibit anomalous Na(+)-K(+)-pump and Na(+)-K(+)-2Cl- co-transport activities. The influence of these univalent ion transport systems upon cellular Na+ and Ca2+ homeostasis invoke their participation in the pathogenesis of hypertension.


Cerebrospinal fluid sodium and enhanced hypertension in salt-loaded spontaneously hypertensive rats. The present study was designed to determine whether increases in sodium concentration in the cerebrospinal fluid (CSF) play a role in the augmented hypertension induced by long-term salt loading in spontaneously hypertensive rats (SHR), and whether the enhanced arginine vasopressin (AVP) activity and/or the sympathetic nervous system contribute to the increased hypertension. Measurement of CSF sodium concentration and systolic blood pressure of SHR during salt loading, with or without uninephrectomy, for 7 weeks. Assessment of the hypotensive response to AVP antagonist and hexamethonium, and the plasma levels of AVP and catecholamines. Salt-loading for 7 weeks led to gradual increase in hypertension in SHR. CSF sodium in the SHR was increased by a combination of uninephrectomy and saline-drinking after 7 weeks, but not 3 weeks. The difference in mean arterial pressure (MAP) among the three groups of SHR disappeared after the combined blockade of AVP and sympathetic nervous function. CSF sodium correlated with both resting MAP and the fall in MAP induced by the combined administration of AVP antagonist and hexamethonium. Plasma levels of AVP were significantly elevated in the salt-loaded uninephrectomized SHR. Plasma catecholamines did not change significantly as a result of treatment. We tentatively conclude that chronic salt loading may lead to an increase in CSF sodium, in association with an enhancement of sympathetic nerve activity and, to some extent, of AVP release. These events may explain the augmented development of hypertension in SHR.


Effect of antihypertensive therapy upon myosin isozyme distribution in spontaneously hypertensive rats. Myosin isozymes have been known to become altered during the development and regression of myocardial hypertrophy, but the mechanism by which the shifting takes place is not known. The present paper describes the effects of antihypertensive drugs, with a known mechanism of action, upon myocardial mass, blood pressure and myosin isoforms in spontaneously hypertensive rats (SHR). SHR were treated with antihypertensive drugs and their blood pressure, myocardial mass and myosin isoforms determined. A shift of myosin isoform from the V3 to the V1 type and normalization of myocardial hypertrophy were seen in rats treated with captopril but not in those treated with diuretics. Clonidine and guanethidine increased the V3 form in association with moderate control of blood pressure and no change in myocardial mass. Treatment with a beta-blocker regressed hypertrophy, controlled hypertension but increased the V3 form. Treatment with minoxidil normalized blood pressure, increased cardiac mass and increased the V3 type. Treatment with different antihypertensive drugs does not cause similar types of shifts in myosin isoform and has divergent effects upon blood pressure and heart weight. Furthermore, there is no correlation between myocardial mass, blood pressure and myosin isozyme shifts. We conclude that factors other than blood pressure, myocardial mass and catecholamines modulate the shifting of myosin isoforms. Since captopril had a greater remedial effect upon myosin isoforms in our study than the more commonly used agents, we recommend that the current criteria for selection of antihypertensive drugs and the relation between those drugs and cardiac function be re-evaluated.


Dopaminergic modulation of the pressure-natriuresis response in rats. The present study was carried out to examine the involvement of dopamine in the pressure-natriuresis phenomenon which has been postulated as a major regulator of extracellular fluid volume and thereby arterial pressure. Dopaminergic modulation of the pressure-natriuresis response was studied in the innervated and denervated rat kidney, to allow a distinction between the effects of neural and extraneural dopamine. The pressure-natriuresis response was studied in anesthetized Sprague-Dawley rats, in which neural and hormonal influences on the kidney were fixed by denervating the kidney and by intravenous infusion of aldosterone, hydrocortisone, vasopressin and norepinephrine. The innervation to the kidney remained intact in some experiments with the selective dopamine-1 antagonist SCH 23390. Urinary excretion of dopamine during the pressure-natriuresis response was also examined in the innervated and denervated rat kidney. Although infusion of dopamine at a dose of 2 micrograms/kg per min had no effect on the pressure-natriuresis response in rats in which neural and hormonal influences on the kidney were fixed, the slopes of the relations between urine flow, sodium excretion and mean arterial pressure in rats given 10 micrograms/kg per min dopamine were significantly greater than those found in the control rats. Renal plasma flow increased significantly in the dopamine-treated rats whilst glomerular filtration rate did not differ between the control and dopamine-treated rats. The dopamine-induced increase in the slope of pressure-natriuresis relationship and renal plasma flow were completely blocked by 0.5 micrograms/kg per min SCH 23390. However, infusion of SCH 23390 alone at 0.5 micrograms/kg per min did not significantly alter the pressure-natriuresis response in rats with either denervated or innervated kidney. In addition, urinary excretion of dopamine derived from neither neural nor extraneural origins was altered in parallel with variations in mean arterial pressure. These results suggest that exogenous administration of dopamine may affect the pressure-natriuresis response by altering the magnitude of arterial pressure-induced changes in tubular sodium reabsorption, via an action of dopamine-1 receptors. However, endogenous dopamine does not appear to be capable of modulating the pressure-natriuresis response.


Platelet neuropeptide Y in spontaneously hypertensive rats. To investigate the pathological role of platelet neuropeptide Y (NPY) in genetically hypertensive rats, we measured the platelet content and plasma concentration of immunoreactive (ir)-NPY in hypertensive and normotensive rats and examined the aggregating ability of rat platelets and the NPY releasing reaction in each of these rat types. In addition, we purified platelet NPY and determined its amino acid sequence. To characterize immunoreactive NPY in rat platelets, rat platelet NPY was purified to homogeneity and the purified peptide was analysed by gas-phase sequencer. Platelet content and plasma concentration of NPY was measured by a sensitive radioimmunoassay for NPY. Aggregating ability was examined by a turbidimetric method; aggregation was recorded for 5 min and the maximum aggregation was read. Rat platelet NPY was purified and the amino acid sequence was determined to be YPSKPDNPGEDAPAEDMARYYSALRHYINLITRQRY. The platelet content of ir-NPY in 5-, 10-, and 15-week-old spontaneously hypertensive rats (SHR) was higher than that in Wistar-Kyoto (WKY) rats of the same age. The platelet content of ir-NPY in 10-week-old stroke prone-SHR was also higher than that in 10-week-old WKY rats. No differences were observed between any of the pairs in any WKY rats, SHR or stroke-prone SHR group with regard to the plasma concentration of ir-NPY. Ir-NPY was not released from rat platelets when adenosine diphosphate was used for aggregation. However, NPY was released from the platelets when they were aggregated by collagen and, furthermore, in this case the amount of NPY released from platelets was greater in SHR than in WKY rats. That the platelet content of NPY in SHR (and stroke-prone SHR) was higher than that in WKY rats seems to be an important genetic characteristic of SHR. As NPY is a potent vasoconstrictor, it may be involved in the progression of vascular lesions.


Alterations in circulating levels and cardiovascular tissue content of neuropeptide Y-like immunoreactivity during the development of deoxycorticosterone acetate-salt hypertension in the rat. To investigate the modification of plasma and tissue neuropeptide Y-like immunoreactivity (NPY-li) concentrations, in relation to blood pressure and plasma catecholamine levels, during the development of deoxycorticosterone acetate (DOCA)-salt hypertension. Mean arterial pressure (MAP), heart rate, tissue and plasma NPY-li levels, and aortic norepinephrine and epinephrine plasma levels were measured in conscious DOCA-salt hypertensive rats treated for 1, 2 and 3 weeks, and in their respective normotensive controls. Both norepinephrine and NPY-li plasma levels increased significantly in parallel with blood pressure during DOCA-salt treatment, so that MAP was significantly correlated with plasma norepinephrine and NPY-li levels in hypertensive rats. Plasma NPY-li levels were also correlated with norepinephrine levels only in hypertensive rats, but were correlated with epinephrine levels only in normotensive animals. Tissue NPY-li content was lower in the mesenteric artery and heart ventricles after 1-3 weeks of DOCA-salt treatment, but the content in the adrenal gland was not significantly different from that in normotensive rats. In DOCA-salt hypertensive rats, increased plasma NPY-li levels originate primarily from the sympathetic nerves, since those levels were correlated exclusively with circulating norepinephrine levels and they were associated with a reduction in NPY-li content of the heart and mesenteric artery. It is thus possible that the enhanced release of NPY-li from sympathetic nerves could contribute to the rise in blood pressure and to the maintenance of hypertension in this experimental model.


Endothelin-specific antibodies decrease blood pressure and increase glomerular filtration rate and renal plasma flow in spontaneously hypertensive rats. Studies were undertaken to clarify the pathophysiologic significance of endogenous endothelin in the control of blood pressure and renal hemodynamics in spontaneously hypertensive rats (SHR). The technique of passive immunization was used to neutralize endogenous endothelin in order to estimate the contribution of endothelin to the in vivo control of blood pressure and renal hemodynamics. Endothelin-specific antibodies were administered intravenously into anesthetized SHR and Wistar-Kyoto (WKY) rats, and the effects upon blood pressure and renal function (renal plasma flow and glomerular filtration rate) assessed. Using the same antibodies, baseline plasma levels of endothelin in both strains of rats were determined by radioimmunoassay. Infusion of endothelin-specific antibodies into SHR decreased mean arterial pressure by approximately 10% and renal vascular resistance and renal vascular resistance by approximately 35%. Glomerular filtration rate and renal plasma flow both increased by approximately 50% over control. In contrast, infusion of normal rabbit serum into SHR or of endothelin-specific antibodies into WKY rats did not result in any significant change in renal hemodynamics or arterial blood pressure. Baseline plasma levels of immunoreactive endothelin in SHR were significantly lower than those in WKY rats. These results suggest that endothelin plays an important role in the modulation of systemic blood pressure and renal function in SHR.


Effects of endothelin upon blood pressure in normotensive rabbits and in perinephritis hypertension. The effects of endothelin upon blood pressure were investigated in normotensive and hypertensive rabbits. Endothelin was injected intravenously into conscious animals and blood pressure was monitored. Groups were pretreated with vehicle, calcium antagonists, indomethacin to block prostaglandin release, or NG-nitro-L-arginine methyl ester (L-NAME) to block endothelium-derived relaxing factor (EDRF) production in order to study the mechanisms of action of endothelin in normotensive and hypertensive animals. Intravenous endothelin caused a rapid depressor response lasting less than 1 min followed by a prolonged pressor response. Calcium antagonists attenuated this pressor response. Hypertensive animals showed a greater sensitivity to calcium antagonists than normotensives. High concentrations of calcium antagonists abolished the pressor response, revealing a more prolonged depressor response lasting up to 5 min. Indomethacin pretreatment caused an apparent dose-related increase in pressor responses in all animals. L-NAME pretreatment enhanced responses in normotensives but caused no change or a decrease in these responses in hypertensive animals. Neither calcium antagonists, indomethacin or L-NAME modified the initial depressor response to endothelin. However when given together with nifedipine infusion, which abolished the pressor response, indomethacin and L-NAME decreased the duration of the depressor response. In conscious rabbits extracellular calcium influx is important in mediating pressor responses to endothelin. In normotensive rabbits endothelin apparently causes release of prostaglandin and EDRF modifying responses. In hypertensive rabbits, a role for prostaglandins but not EDRF was observed in modulating responses to endothelin. Thus, the measured response to endothelin is the sum of a number of effects, the relative importance of which may be altered in pathological conditions.


Relation between inhibition of renal angiotensin II production and hemodynamic effect of captopril in anesthetized rabbit. This study was conducted in order to determine the relation between the renal hemodynamic effect of an angiotensin converting enzyme (ACE) inhibitor and its effect upon plasma angiotensin II levels in the rabbit. The effect of captopril upon arterial and renal venous plasma angiotensin II concentrations was assumed to reflect the systemic and renal actions of ACE inhibition. Systemic blood pressure, renal blood flow (RBF), and arterial and renal venous plasma concentrations of angiotensin II and angiotensin I were measured in five groups of anesthetized rabbits; groups Ia and Ib consisted of sodium-replete and group II sodium-deplete rabbits in which captopril was administered in a maximal ACE inhibiting dose of 2 mg/kg, intravenously, followed by an intra-arterial (group Ia) or an intravenous (group Ib) infusion of 1 mg/kg per h; group III consisted of sodium-replete rabbits given a low captopril dose of 10 micrograms/kg per min, intra-arterially; and group IV represented control levels. In a separate group of rabbits (group V) the effects of a low dose of 10 micrograms/kg per min captopril in the presence of the angiotensin II antagonist DuP 753 were studied. The high dose of captopril decreased blood pressure and increased RBF in both sodium-replete and sodium-deplete rabbits. Arterial and renal venous angiotensin II levels were low in group Ia compared with groups Ib and II; however, in all three groups angiotensin II levels were markedly decreased during high-dose captopril administration. The low dose of captopril caused approximately the same increase in RBF, despite no change in angiotensin II levels. Angiotensin I concentrations tended to increase during high-dose captopril administration due to blockade of negative feedback of renin release. A time trend did not account for the results, since blood pressure, RBF and angiotensin II were stable over a 1-h period in control experiments. These results suggest that different pools of renal angiotensin II may exist, and that a small critically located pool, possibly in the endothelium, may be important in renal vascular control.


Partial escape of angiotensin converting enzyme (ACE) inhibition during prolonged ACE inhibitor treatment: does it exist and does it affect the antihypertensive response? To investigate whether the compensatory rise in renin and plasma angiotensin I in response to repeated angiotensin converting enzyme (ACE) inhibitor treatment results in a partial escape of ACE inhibition over a 24-h dosing interval. A single-blind placebo-controlled study in two parallel groups of eight hypertensive subjects receiving a once-daily dose of the ACE inhibitor, spirapril, of either 12.5 or 25 mg. Detailed 24-h studies were performed at the end of 2 weeks of placebo, and after the first dose and 2 weeks administration of spirapril. Twenty-four-hour ambulatory blood pressure was measured invasively. True' angiotensins I and II were measured by radioimmunoassay after high-performance liquid chromatography separation. Both for the lower and higher doses of spirapril, the time-course of changes of spiraprilat, the active metabolite of spirapril, and ACE activity was similar but the maximal rise in angiotensin I was twofold higher after 2 weeks administration than after the first dose. Angiotensin II after the first dose of spirapril fell rapidly, with lowest values 2 to 4 h after dosing. At the end of dosing interval angiotensin II had returned to values seen under placebo with the 12.5-mg dose, but at the end of the 24-h period it was still suppressed with the 25-mg dose. Compared with these first-dose responses the initial maximal degree of angiotensin II suppression after 2 weeks administration of either dose was similar, but during the subsequent hours the degree of angiotensin II suppression tended to be less with the lower and was significantly less with the higher dose of spirapril. With the lower dose of spirapril responses of 24-h ambulatory blood pressure to the first dose and to 2 weeks of administration were almost superimposable, although blood pressures in the second half of the dosing interval tended to be higher during chronic treatment. With the higher dose the response of nocturnal blood pressure after 2 weeks administration was diminished by 8.8 mmHg systolic and 6.8 mmHg diastolic. Repeated ACE inhibitor treatment with once-daily spirapril leads to a partial escape of ACE inhibition, as reflected by a shorter duration of angiotensin II suppression. This escape also affects the antihypertensive response in the second half of the dosing interval.


Altered number of platelet angiotensin II receptors in relation to plasma agonist concentrations in normal and hypertensive pregnancy. The relation between plasma angiotensin II concentrations and the platelet angiotensin II receptor was examined in four different groups of subjects. Platelet receptors were used as representative of physiologically significant sites such as in vascular smooth muscle. A control group consisting of non-pregnant females was studied together with three pregnant groups: normal pregnant women in both early and then late gestation and women with diagnosed pregnancy-induced hypertension (PIH). Blood was collected from each subject for estimation of plasma angiotensin II concentration and isolation of platelets, which were then used in non-competitive binding studies. Both receptor capacity and affinity for the ligand were calculated for each subject. In the control group, a significant negative correlation between angiotensin II and receptor capacity was established. This was in marked contrast to the first trimester group which showed no such correlation and where there was a significant reduction or nil receptor capacity but only a slight elevation in mean plasma angiotensin II concentration. This phenomenon of reduced or absent binding persisted into the third trimester when plasma angiotensin II was significantly elevated compared with all other groups. PIH subjects had the lowest plasma angiotensin levels and 90% had clearly measurable binding to the platelet receptor, which was not however as high as that in the control group. Two normotensive subjects who demonstrated significant potentiation of receptor binding in the third trimester subsequently developed PIH. The inverse relation between plasma angiotensin II and its platelet receptor, found in non-pregnant subjects, is significantly altered in normal pregnancy. Reduced receptor capacity and lack of relation with circulating ligand observed in early gestation reflects an alteration at the receptor level which is independent of plasma angiotensin II concentration. This alteration appears to persist throughout pregnancy except in subjects predisposed to PIH when receptor binding is closer to non-pregnant values. Changes in receptor binding found in people who ultimately developed PIH but who were still clinically normal at the time suggest that binding to the platelet receptor could be used as a screening test for all primiparae to identify those predisposed to PIH later on in pregnancy.


Acute and chronic regulation of atrial natriuretic peptide in human pregnancy: a longitudinal study. To determine whether the increase in extracellular fluid volume (ECFV) that occurs during pregnancy alters: (1) the baseline regulation of atrial natriuretic peptide (ANP); or (2) the ANP response to intravascular volume expansion with either haemaccel or hypertonic saline. A group of normal pregnant subjects was studied longitudinally on three occasions, commencing before 16 weeks of gestation. They were compared with a group of age-matched non-pregnant women. Dietary sodium intake and posture were carefully controlled. Plasma volume and total ECFV were determined by tracer dilution methods, using Evans Blue and 20% mannitol, respectively. Plasma ANP and aldosterone concentrations were measured by radioimmunoassay. Plasma ANP did not increase during pregnancy despite increases in both plasma and total ECFV. The plasma ANP response to acute intravenous volume expansion in later pregnancy appears to be more sensitive than either in early pregnancy or in non-pregnant subjects. The initial ANP response to infusions of haemaccel during pregnancy was greater than the ANP response to saline. During a normal pregnancy, plasma ANP is maintained in the normal non-pregnant range, despite an increase in plasma volume when the effects of dietary sodium intake and posture are carefully accounted for. The ANP response to intravenous volume expansion is enhanced in late pregnancy. The greater ANP response to haemaccel infusions during pregnancy suggests that an increase in atrial stretch mediates the secretion of ANP following intravenous volume expansion.


Platelet alpha 2-adrenoceptor density in pregnancy-induced hypertensive patients: effect of epidural analgesia. Although pregnancy induced hypertension (PIH) is an important and relatively common medical problem, its pathophysiology remains unresolved and the search for a biochemical marker that precedes the hemodynamic abnormalities of PIH continues. Since human platelets contain alpha 2-adrenoceptors, these receptors were measured in women with PIH to determine whether patients with PIH have alpha 2-adrenoceptor abnormalities that might cause or exacerbate the hypertensive process. The effect of epidural analgesia upon blood pressure and its relation to changes in platelet alpha 2-adrenoceptor density were also investigated. Biochemical measurements and radioligand binding assays in platelets were performed on 33 patients with the criteria for PIH and on 26 healthy pregnant women. Blood pressure was significantly elevated in hypertensive women when compared with normotensive pregnant women although, in this group, blood pressure returned to normal levels in response to epidural analgesia. In drug-free hypertensive patients, the specific binding of 3H-yohimbine to platelet membranes increased significantly compared with that in control pregnant subjects. In contrast, the dissociation constant was not significantly different in the two groups. Furthermore, alpha 2-adrenoceptor density in the group with PIH returned to normal levels in response to epidural analgesia. Our findings indicate that PIH is characterized by an exaggerated response of platelet alpha 2-adrenoceptor density to a rise in blood pressure and that this alteration could be significant in the pathogenesis of hypertension. Furthermore, human alpha 2-adrenoceptors undergo regulatory mechanisms similar to those recently described for adrenergic receptors in a variety of animal models.


Platelet Na(+)-H+ exchanger activity in normotensive and hypertensive subjects: effect of enalapril therapy upon antiport activity. Primary hypertension has been reported to be associated with an enhancement of Na(+)-H+ exchange. However, details of the kinetic properties of the Na(+)-H+ exchanger in hypertensives and its dependence upon age and gender in normotensives are unknown. We determined the activity of the platelet Na(+)-H+ exchanger in 20 normotensives and 26 untreated primary hypertensives. In eight hypertensive individuals antihypertensive treatment was interrupted for 1 week. Treatment for 6 weeks with a daily single dose of 10 mg enalapril decreased mean arterial pressure to 105.7 +/- 11.6 mmHg. Platelets were loaded with the intracellular pH (pHi) indicator 2'-7'-bis-carboxyethyl-5(6)-carboxyfluorescein (BCECF) and acidified by propionic acid. Initial velocities of pH recovery were determined and used for calculation of maximum velocity (Vmax), baseline pHi and the pHi value for half maximal activation (pH0.5) of the Na(+)-H+ exchanger in each individual. In normotensives, Vmax averaged 0.05 +/- 0.01 dpHi/min independently of age, gender and actual diastolic blood pressure. In hypertensives, two different subgroups were defined bearing either low or high Na(+)-H+ exchange activity. Values of pHi and pH0.5 were identical in all subgroups irrespective of Vmax. The twofold enhancement of Na(+)-H+ exchange in the second group was preserved in thrombin-stimulated platelets. Vmax values remained unaffected by enalapril treatment. Enhanced Na(+)-H+ exchange activity in hypertensives is primarily characterized by an increase in Vmax. This enhancement is refractory to antihypertensive treatment and therefore appears to be a relatively fixed parameter.


Further investigation of platelet cytosolic alkalinization in essential hypertension. To verify that platelet cytosolic pH is altered in essential hypertension and to investigate the mechanisms involved. Cytosolic pH was determined in unstimulated platelets by the fluorescent indicator 2,7-bis-carboxyethyl-5(6)-carboxyfluorescein (BCECF). Membrane microviscosity was evaluated by the fluorescence anisotropies of diphenylhexatriene (DPH) and its cationic derivative trimethylamino-diphenylhexatriene (TMA-DPH). The cytosolic alkalinization previously observed in platelets from untreated hypertensive patients was confirmed. The buffering capacity appeared unaltered and the cytosolic pH was not modified by 50 mumol/l N-5-ethylisopropylamiloride, a specific inhibitor of the Na(+)-H+ exchange. Exposure to external Na(+)-free media produced an intracellular acidification that was similar in hypertensive and normotensive donors and maintained the cytosolic pH difference between the two groups. In the two blood pressure groups platelet cytosolic pH varied inversely with the steady-state anisotropy of TMA-DPH but not with that of DPH. Experimentally induced acidification of the cytosol by Na+ removal with or without nigericin treatment was accompanied by rises in TMA-DPH anisotropy. This study of platelet intracellular pH in essential hypertension confirms cytosolic alkalinization and demonstrates its association with changes in the dynamic properties of the platelet plasma membrane.


Plasma norepinephrine is a major determinant of hemodynamic alterations with sodium loading. To assess hemodynamic responses to 3 weeks of sodium loading and to evaluate factors which contribute to hemodynamic alterations. Analysis of patients' central hemodynamic and laboratory variables before and after sodium loading. A referral centre. Thirty-one elderly hypertensives. Doppler flowmetry and laboratory examinations were performed during different sodium intake; 120 mmol/day for 8 weeks and 344 mmol/day for 3 weeks. Patients were divided into three groups; those in whom sodium loading increased total peripheral resistance (SST); those in whom salt repletion increased cardiac index (SCC); a non-salt-sensitive group (NSS). The overwhelming reaction to salt loading is that, with time, the NSS and SSC groups became part of the SST group. When the SSC patients became SST with sodium loading, serum sodium and plasma arginine vasopressin decreased and haematocrit increased, suggesting that the excretion of sodium and water accompanied with a decrease in circulating plasma volume may be responsible for the hemodynamic alteration from SSC to SST. In those who remained in the SSC group throughout the 3 weeks of salt repletion, plasma norepinephrine decreased on all of days 7, 14 and 21 of the high-sodium diet compared with the regular-sodium regimen, whilst in patients in the SST group on day 21 of the high-sodium diet plasma norepinephrine remained unchanged throughout the 3 weeks of salt loading. We confirmed a changing pattern of initially high cardiac index giving way to a persistently elevated total peripheral resistance with sodium loading. Plasma norepinephrine proved to be the best predictor of which subjects were or became SST.


Cardiovascular responses to stress in young hypertensive women. The aim of the study was to investigate the haemodynamic effects of hormonal changes during the menstrual cycle in 11 hypertensive women aged between 29 and 38 years. In randomized order, the subjects were examined on days 2-7 (follicular phase) and on days 20-24 (luteal phase). All medication was withdrawn on average 5 weeks prior to the experiment. The results in the hypertensive group were compared with those of a control group consisting of 11 normotensive women aged between 21 and 46 years who had earlier taken part in an identical experiment. A standardized mental stress test and a 24-h ambulatory blood pressure and heart rate recording were performed. RESULTS. Prestress resting heart rate was significantly higher in the hypertensive group and a significant difference was maintained throughout the entire stress experiment. Heart rate, systolic and diastolic blood pressure increased highly significantly in both groups during the exposure to mental stress, but no difference in heart rate or blood pressure reactivity between the normotensive and hypertensive groups was found in either phase. Heart rate reactivity did not differ during the two phases in the hypertensive group, in contrast to our previous findings in normotensives. During 24-h ambulatory recording both groups had slightly but significantly higher heart rate and systolic blood pressure in the luteal phase. In the hypertensives the diastolic blood pressure was also higher in this phase. Both groups had significantly higher serum oestradiol and progesterone levels in the luteal phase. The findings of the present study support the hypothesis that female sex hormones affect cardiovascular control in both normotensive and hypertensive women.


Urinary kallikrein excretion is low in malignant essential hypertension. To determine whether the urinary excretion of kallikrein is altered in patients with previously malignant hypertension. Twenty-two patients with malignant hypertension (fundus hypertonicus III or IV) in the Gothenburg area were studied over a 3-year period. After treatment had begun they were investigated for blood pressure control, family history of hypertension, renal function and urinary kallikrein and plasma prekallikrein concentrations. Twenty-two patients with treated non-malignant hypertension and 36 control subjects were investigated concomitantly. The two hypertensive groups were also separated into subgroups of essential and secondary hypertension. Prekallikrein was activated and kallikrein determined by a spectrophotometric assay using a synthetic chromogenic substrate. Renal function was estimated by serum creatinine and 51Cr-ethylenediaminetetraacetic acid clearance. Prekallikrein levels tended to be elevated in all groups of hypertensive patients compared with controls whilst urinary kallikrein was significantly decreased in malignant hypertensives. The most pronounced suppression of urinary kallikrein was seen in the group of patients with essential malignant hypertension. The differences persisted when urinary kallikrein was related to the degree of renal impairment or when urinary volume was taken into account. There was no relation between family history of hypertension and low levels of urinary kallikrein. Decreased urinary kallikrein could indicate depressed activity in the renal kallikrein-kinin system, which may be associated with the initiation of essential malignant hypertension.


Diurnal blood pressure variations and silent cerebrovascular damage in elderly patients with hypertension. To examine the effect of diurnal blood pressure changes upon cerebrovascular damage in elderly patients with hypertension. Fifty-four asymptomatic hypertensive and 34 normotensive elderly subjects underwent both 24-h non-invasive ambulatory blood pressure monitoring and brain magnetic resonance imaging. METHODS. Diurnal variation was defined as a difference of greater than or equal to 10 mmHg between mean awake and asleep systolic blood pressure. Hypertensives were thus classified as dippers or non-dippers. Low intense foci (lacunae) and advanced periventricular hyperintensity were identified as silent cerebrovascular damage. In the hypertensive group, lacunae were correlated more closely with mean asleep systolic blood pressure than with mean awake systolic blood pressure. Age, awake blood pressure, predicted whole blood viscosity, lipid profiles or quantity of sleep did not differ between the hypertensive dippers or non-dippers. The non-dippers, however, showed significantly higher grades of cerebrovascular damage as well as cardiac hypertrophy by electrocardiography than the dippers, whose results were similar to those of normotensives in this regard. An absent or lower nocturnal blood pressure fall in elderly hypertensives is associated with silent cerebrovascular damage. In contrast, the presence of a nocturnal fall could prevent the development of hypertensive vascular damage.


Does non-invasive ambulatory blood pressure monitoring disturb sleep? To assess the effects of non-invasive ambulatory blood pressure monitoring upon sleep in healthy men. Spontaneous variations in the quality of sleep were assessed by taking polygraph recordings in 44 healthy men aged 17-69 years. Subjects were allowed one night to become accustomed to the laboratory environment, and then their sleep was recorded for 4 consecutive nights. On day 4 blood pressure was measured every 10 min for 24 h. The blood pressure recording procedure caused a small but significant decrease in the amount of slow-wave sleep and an increase in the duration of nocturnal awakenings. As a result, sleep efficiency was decreased. The number of nocturnal awakenings was not affected by the blood pressure measurements. The effects of ambulatory blood pressure monitoring were qualitatively similar in young and older volunteers. Non-invasive ambulatory blood pressure monitoring induces modest sleep disturbances which are unlikely to artifactually distort the physiological 24-h blood pressure profile.


Difficulties in diagnosing hypertension: implications and alternatives. To estimate the magnitude of misclassification rates with commonly used algorithms for the detection of hypertensives and to suggest a sequential approach to screening. A conventional statistical model was used with several different algorithms to determine the number and types of errors made in categorizing two different populations, a general population sample and a population with a high risk of hypertension. The calculations were made for single-visit screens, similar to those used in epidemiologic studies, for three-visit screens commonly used in clinical practice and clinical trials for cutoff points of 85, 95 and 105 mmHg. A sequential probability ratio screen was proposed and the error rates estimated. Perhaps only one-third to two-thirds of people whose measured diastolic pressures exceed 95 mmHg actually have average pressures that high. The disparity between a single measured diastolic pressure and the mean of many pressure values also leads to errors in identifying individual subjects with mild hypertension. In a general population, single measurements of diastolic pressure exceed 95 mmHg in approximately equal numbers of normotensive, borderline and hypertensive subjects; moreover, one-third of those who are usually in the hypertensive range are not identified. All commonly used screening algorithms give too many false-positive and/or false-negative results. A sequential screening algorithm averaged 3.8 visits per subject and identified 95% of the hypertensives, with only 2.5% of those identified having usual diastolic pressures below 90 mmHg. Population-based surveys like the National Health and Nutrition Examination Survey (NHANES) may markedly overestimate the true prevalence of hypertension. This overestimate is greatest for mild hypertension and could significantly affect the cost/benefit analyses of public health policy. Alternative screening methods, such as the sequential algorithm proposed, may have significant benefits in providing a correct classification.


Both tumor necrosis factor and nitric oxide participate in lysis of simian virus 40-transformed cells by activated macrophages. SV40 transformation of rodent fibroblasts generally produces cells that are highly sensitive to killing by activated macrophages. The cell line SV-COL-E8 (E8) is typical of SV40-transformed mouse fibroblasts in that it is readily lysed when exposed to activated macrophages. This killing is not due solely to TNF, because soluble TNF alone is incapable of lysing these cells. TNF is, however, necessary for lysis since antibodies to TNF will prevent macrophage-mediated lysis. Similarly, E8 is not sensitive to nitric oxide (NO); however, NO is also necessary for lysis since inhibition of NO generation (by coincubation with the arginine analogue NG-monomethyl-1-arginine) with Fe(II)) blocks lysis of E8 by activated macrophages. Cytolysis by macrophages is contact dependent, suggesting that the cell-associated TNF precursor may be involved in mediating cytolysis. However, transfected cell lines bearing cell-associated TNF precursor do not mediate killing of E8. Thus, killing of E8 either involves both TNF and NO in addition to a third, as yet unidentified, lytic mechanism, or killing requires the contact-dependent delivery of TNF and NO from the macrophage to its target.


Study of the outbreak of Japanese encephalitis in Lakhimpur district of Assam in 1989. An outbreak of Japanese encephalitis was reported from Lakhimpur district of Assam in July-August, 1989. The outbreak affected 90 villages of the district, covering a population of approximately 36,000. There were 140 cases and 70 deaths due to the epidemic, giving a case fatality rate of 50%. There were no cases from Gogamukh area of the district, where a pilot Japanese encephalitis vaccination project was conducted in the population between July-August 1987, with Kasauli Japanese encephalitis vaccine. Serological examination of acute and convalescent cases showed Japanese encephalitis specific IgM indicating strong evidence of recent Japanese encephalitis infection.


Stromal cellular response in breast tumours and allied lesions. Histopathological study for stromal cellular response was made on 200 cases of benign and dysplastic lesions and malignancy of breast. Infiltrations with lymphocytes and plasma cells were observed in 64% cases of fibroadenoma, 66.6% cases of giant fibroadenoma, 61% cases of mammary dysplasia and 33.3% cases of gynaecomastia. While mast cell infiltration was not observed in giant fibroadenoma, its presence was observed in 92% cases of fibroadenoma, 77.8% cases of mammary dysplasia and 33.3% cases of gynaecomastia. Lymphocytes and plasma cells infiltrations were observed in 100% of cases of invasive duct carcinoma, medullary carcinoma and fibrosarcoma. Comedocarcinoma showed infiltration with these cells in 75% of cases while that for colloid carcinoma and Paget's disease of breast were observed in 50% of cases of each. Infiltrations with mast cells were observed in 92.3% cases of invasive duct carcinoma, 75% cases of comedocarcinoma and 25% cases of medullary carcinoma. Other malignant conditions of breast did not show mast cell infiltration. Degree of infiltration with lymphocytes and plasma cells was mainly of low grade in benign and dysplastic lesions compared to high degree of infiltration in malignancy. Mast cell infiltration was of low degree in both the types of lesions.


The spinal pharmacology of acutely and chronically administered opioids. Systematic studies on the pharmacology of the antinociceptive activity of spinally administered agents have emphasized the action in animal models of mu and delta opioid receptors. Importantly, aside from receptor selectivity, the opioid agonists differ in the property of efficacy. Agents with high efficacy (large receptor reserves) show smaller rightward shifts in their dose-response curves in the face of a given degree of opioid tolerance or when the stimulus intensity is elevated. With regard to loss of drug effect with long-term exposure (tolerance), multiple mechanisms may be considered, including changes in stimulus intensity, change in afferent processing, or changes in receptor number/coupling. Basic studies are providing insights into these several mechanisms.


Cystic islet cell tumors of the pancreas. A clinico-pathological report of two nonfunctioning cases and review of the literature. Cystic islet cell tumors of the pancreas are extremely rare. The authors report their personal experience with two cases of nonfunctioning cystic endocrine neoplasms. The tumor was diagnosed preoperatively in one case by ultrasonography (US)-guided fine-needle aspiration cytology, while in the other it was identified only in the surgical specimen after a clinical-radiologic diagnosis of pancreatic mucinous cystic tumor. Immunohistochemical assay showed positivity for the generic neuroendocrine markers (neuron specific enolase, or NSE, synaptophysin, and chromogranin A) in both cases and also for glucagon in one case. The neoplasms were resected by distal pancreatectomy with splenectomy and intermediate pancreatectomy respectively. Both patients are alive and recurrence-free 6 mo and 2.5 yr, respectively, after surgery. The authors also review the existing literature, discussing the pathogenesis of such tumors and the imaging techniques and surgical strategies adopted in their management.


Angiotensin converting enzyme: an in vivo and in vitro marker of endothelial injury. An elevated level of von Willebrand factor (vWf) is a well-established marker for both in vivo and in vitro endothelial cell injury. Recent studies indicate that the plasma level of angiotensin-converting enzyme (ACE) in systemic sclerosis is reduced in association with elevated vWf levels. Because the endothelial cell is capable of producing both mediators, and because endothelial cell injury is a fundamental process in systemic sclerosis, we investigated in this study the effect of in vitro endothelial cell injury on the synthesis of both factors. Endothelial cells derived from human umbilical veins, in the second passage, were activated by exposure to interleukin-1 or lymphotoxin or were injured by radiation, actinomycin, or trypsin (each can be shown to induce dose-dependent endothelial cell cytotoxicity). ACE (spectrophotometric method) and vWf levels (enzyme-linked immunosorbent assay method) were determined in the supernatant and in the cell lysate 48 hours after cellular injury and activation. An increase in vWf levels was found in the lysate and in the supernatant from the cells that underwent injury or activation, whereas ACE levels were increased after activation but decreased after injury. Next, and as an in vivo clinical corollary to the in vitro endothelial cell injury, we evaluated ACE and vWf levels in the plasma of seven children in the acute phase of Kawasaki disease, a disorder characterized by widespread vascular injury. Plasma ACE levels were significantly lower than control levels, whereas vWf levels were increased, reflecting the known prominent endothelial cell injury in this disease.(ABSTRACT TRUNCATED AT 250 WORDS)


Production of leukotrienes and thromboxane by resident and activated rat alveolar macrophages: a possible role of protein kinase C. Arachidonic acid metabolism in resident rat alveolar macrophages and in those activated with complete Freund's adjuvant (CFA) was studied. Adult Sprague-Dawley rats were injected with 0.05 ml CFA, and macrophages were harvested 10 days later. Macrophages were labeled overnight with carbon 14-labeled arachidonic acid, washed, and then stimulated with calcium ionophore A23187 (IoA), phorbol myristate acetate (PMA), or zymosan for 30 minutes. Prostaglandins, thromboxane, and leukotrienes were extracted from the medium and analyzed by radioimmunoassay or radio high-pressure liquid chromatography. Cell lipids were analyzed by radio thin-layer chromatography. Medium and cell beta-glucuronidase activity and protein kinase C activity of the membrane fraction were also assayed. We found (1) lower leukotriene B4 (LTB4) production in stimulated resident macrophages when compared with resident macrophages after IoA stimulation--the suppressed LTB4 production was reversed by PMA; (2) unchanged or higher LTB4 production in activated macrophages when compared with resident macrophages after zymosan stimulation; (3) inhibition of zymosan-stimulated LTB4 production by staurosporine, a protein kinase C inhibitor, in both groups; and (4) lower diacylglycerol (DAG) production in activated macrophages when compared with resident macrophages after IoA stimulation, but not after zymosan stimulation. These results suggest that the reduced response of activated macrophages to IoA is due to decreased production of an endogenous protein kinase C activator. This hypothesis was further supported by the observation that protein kinase C activation in response to IoA was lower in activated macrophages than in resident macrophages. In contrast, zymosan stimulation resulted in higher protein kinase C activation in activated macrophages when compared with resident cells. We hypothesize that protein kinase activation is necessary for leukotriene production and that the preserved ability of zymosan to activate PKC via DAG accounts for the high leukotriene production in zymosan-activated macrophages. We also found that stimulated thromboxane production was higher in activated than resident cells, regardless of the stimulus, and that thromboxane production was not affected by staurosporine. Thus alterations of eicosanoid metabolism in immunologically activated macrophages depend on the stimulus used and the type of eicosanoid examined. Furthermore, leukotriene biosynthesis in rat alveolar macrophages may be regulated by protein kinase C.


Modulation of differentiation of rat granulosa cells in vitro by interferon-gamma. The effects of recombinant rat interferon-gamma (rRaIFN-gamma) and rat IFN (RaIFN, a mixture of IFN-gamma and -alpha) on basal and FSH-induced ovarian granulosa cell function were studied. Granulosa cells were harvested from diethylstilboestrol-treated immature rats and cultured (2 x 10(5) viable cells/well per 0.5 ml) in serum-free medium with or without treatment for 48 h. In the presence of FSH (20 ng/ml), rRaIFN-gamma (10-1000 U/ml) significantly inhibited FSH-stimulated aromatase activity (76.4 +/- 2.3% maximum inhibition compared with FSH treatment alone), inhibin (40.4 +/- 3.7%), progesterone (47.7 +/- 8.6%) and 20 alpha-hydroxypregn-4-en-3-one (20 alpha-OHP) (51.8 +/- 1.7%) production in a dose-dependent manner. Furthermore, rRaIFN-gamma inhibited FSH- and forskolin (FSK; 30 mumol/l)-induced extracellular cAMP accumulation (46.0 +/- 6.6% and 29.1 +/- 7.3% respectively). The inhibitory effect of rRaIFN-gamma on FSK-induced cAMP was accompanied by decreased FSK-induced aromatase activity, inhibin, progesterone and 20 alpha-OHP production. rRaIFN-gamma had no detectable effect on aromatase activity, progesterone production and 20 alpha-OHP production in the absence of FSH, but significantly stimulated basal inhibin production by 1.5-fold. rRaIFN-gamma alone also caused a small but significant increase in basal levels of cAMP. The time-course studies showed that FSH-induced aromatase activity and inhibin production were consistently suppressed by rRaIFN-gamma, FSH-induced progesterone and 20 alpha-OHP were inhibited at 1 and 2 days and then stimulated on days 3, 4 and 5 relative to FSH alone.(ABSTRACT TRUNCATED AT 250 WORDS)


Further characterization of the steroidogenic responsiveness of purified zona fasciculata/reticularis cells from bovine adrenal cortex before and after primary culture: changing responsiveness to phosphoinositidase C agonists. When bovine adrenocortical cells from the zona fasciculata/reticularis (zfr) are maintained in primary culture, cortisol secretion in response to acute stimulation with ACTH and adrenaline (which activate adenylate cyclase) is seen to increase steadily over the first 48 h, while secretion in response to angiotensin II and acetylcholine (which activate phosphoinositidase C) shows an initial decline in the first 24 h and a recovery to maximum after 48 h. We have investigated whether these discrepant changes in cortisol secretory response to the different agonists are due to changes in formation of the associated second messengers (cAMP or inositol phosphates), or altered coupling of these second messenger signals to steroid secretion. Increases in steroid secretion in response to ACTH and adrenaline were paralleled by increased cAMP. Steroid secretion in response to exogenous 8-bromoadenosine 3':5'-cyclic monophosphate also increased steadily during this 48-h period. Thus increased responsiveness was due to both increased second messenger formation and increased coupling to the steroid secretory response. The decreased steroid secretory response to angiotensin and acetylcholine after 24 h, and subsequent recovery after 48 h in culture, were accompanied by an increased formation of phosphoinositols after 24 h and a further increase by 48 h. However, the steroid secretory response to a combination of calcium ionophore and the protein kinase C activator, phorbol 12-myristate 13-acetate, was reduced after 24 h and recovered by 48 h of culture. Fura-2-loaded cells also showed an increase in intracellular [Ca2+] after 24 h in culture.(ABSTRACT TRUNCATED AT 250 WORDS)


Borate and molybdate inhibition of catechol estrogen and pyrocatechol methylation by catechol-O-methyltransferase. The possibility that boron and molybdenum anions can influence sex steroid metabolism by forming complexes with catechol estrogens has been studied in vitro. The formation of 2-methoxyestrone (2-OHE1 2-Me) from 2-hydroxyestrone (2-OHE1) by catechol-O-methyltransferase (COMT) was followed by measuring the transfer of the radiolabeled methyl group from S-adenosylmethionine. In the presence of both sodium tetraborate and sodium molybdate using a phosphate buffer medium, the formation of 2-OHE1 2-Me decreased as the anion:2-OHE1 molar ratio was increased. However, the reverse effect was observed when using a tris buffer medium and further investigation showed that phosphate and sulphate also enhanced COMT activity in a tris buffer medium. Boric acid affinity medium, used as a substitute for borate salt, also showed a negative relationship with enzyme activity in a phosphate buffer medium, and inhibition of methylation was more marked than with the free anion. Erythrocytes contain appreciable amounts of COMT, which is mostly responsible for the rapid O-methylation of catechol estrogens in blood. The methylation of a simple catechol compound, 1,2-dihydroxybenzene (pyrocatechol) was therefore studied using rat red blood cell lysates. Methylation was inhibited in a concentration-related manner by borate, as found in the studies of 2-OHE1. It is possible that high dietary intakes of boron or molybdenum could regulate the rate of catabolism, or even the metabolic fate of the major estrogens.


Vanadium effect on the activity of horseradish peroxidase, catalase, glutathione peroxidase, and superoxide dismutase in vitro. The effect of vanadium (V) on the activity of horseradish peroxidase, catalase, glutathione peroxidase, and superoxide dismutase has been studied. A competitive inhibition pattern was evident for vanadate ions on the activity of horseradish peroxidase (Ki = 41.2 microM). No significant inhibitory effects were found when V(V) was tested with catalase and when either V(IV) or V(V) were assayed with glutathione peroxidase. For the latter, the effect of V on the different components of the reaction system was investigated. V(V) did not significantly affect SOD activity when assayed with the sulfite method, which is devoid of interferences with V(V); however, there was an apparent inhibitory dose-response pattern for either V(IV) or V(V) using the pyrogallol assay, owing to an interference of pyrogallol with the metal. Besides, no significant binding of V(IV) or V(V) to the enzyme could be demonstrated. The lack of a direct inhibitory effect of V on the activity of the main antioxidant enzymes suggests that many biological and toxicological effects of V may be mediated more by oxidative reactions of the metal or of its complexes with physiologically relevant biomolecules than by a direct modulation of enzymatic activities.


The weakly virulent herpes simplex virus type 1 strain KOS-63 establishes peripheral and central nervous system latency following intranasal infection of rabbits, but poorly reactivates in vivo. The virological, clinical and electrophysiological manifestations of acute and experimentally reactivated infections of the rabbit central nervous system (CNS) and trigeminal ganglia have been studied after intranasal infection with herpes simplex virus type 1 (strain KOS-63). All animals shed virus in nasal secretions during the acute phase of infection. Although no rabbits developed clinical signs during the acute phase of infection, mild electroencephalographic (EEG) abnormalities consistent with viral invasion of the CNS were seen. KOS-63 produced only occasional gross and histopathologic herpetic lesions of the CNS and was very rarely recovered from the brain. These results indicate that KOS-63 was poorly neuroinvasive and only mildly neurovirulent during the acute phase of infection. However, KOS-63 did establish latency within the CNS and trigeminal ganglia of infected rabbits as demonstrated by in situ hybridization and by recovery of virus from co-cultivation cultures, but not from cell-free homogenates of nervous tissue. Cyclophosphamide and dexamethasone injections were used to reactivate latent CNS and trigeminal ganglionic infections. Following injection of the drugs, no animal shed virus in nasal secretions or developed obvious clinical or EEG changes. However, KOS-63 was recovered from co-cultivation cultures of brain and trigeminal ganglia at greater frequency following drug injection than during latency. These results indicate that KOS-63 was only poorly susceptible to drug-induced reactivation. In vivo experiments confirmed that the apparent poor neuroinvasiveness and weak neurovirulence of KOS-63 was not due to viral temperature-sensitive defects, deficient production of viral thymidine kinase, or abnormal defects in viral DNA polymerase function.


Radiosurgery as part of the initial management of patients with malignant gliomas. Between May 1988 and May 1991, 41 patients with malignant gliomas were enrolled onto a prospective study designed to evaluate the role of radiosurgery as a component of initial management. Thirty-seven patients underwent radiosurgery according to the protocol and were assessable for survival and complications of treatment. Diagnoses included glioblastoma multiforme (GBM) in 23 (62%) cases and anaplastic astrocytoma in 14 (38%) cases. In 20 (54%) cases, surgical resection was attempted initially, whereas 17 (46%) patients underwent biopsy only. Patients in the study group received external-beam radiotherapy that consisted of 5,940 cGy given in 33 fractions to partial brain fields that encompassed the primary tumor with a 3 to 4 cm margin. Radiosurgery, used as a technique for boosting the dose to any residual contrast-enhancing mass lesion, was given 2 to 4 weeks after the completion of conventional radiotherapy. Minimum radiosurgical doses ranged from 1,000 to 2,000 cGy (median, 1,200 cGy), whereas maximum doses ranged from 1,250 to 2,500 cGy (median, 1,500 cGy). The median tumor volume at the time of radiosurgery was 4.8 cm3 (range, 1.2 to 72 cm3). Adjuvant chemotherapy was not given. After a median follow-up of 19 months, only nine of 37 (24%) patients have died. Six patients (all glioblastoma multiforme) died of recurrent tumor, whereas death was attributable to complications of treatment in two cases and intercurrent disease in one case. Four patients with recurrent tumor failed at the margins of the radiosurgical treatment volume, whereas two patients progressed locally. One patient is alive with local and marginal failure. Seven (19%) patients underwent reoperation at a median time of 5 months (range, 1 to 14 months) after radiosurgery. We conclude that radiosurgery is a useful adjunct to other modalities in the initial management of patients with small, radiographically well-defined malignant gliomas.


Hypercholesterolemia after chemotherapy for testis cancer. The study was designed to determine prospectively the prevalence of fasting serum lipid abnormalities in patients who were treated with cisplatin-based chemotherapy for germ cell tumors. We unexpectedly had demonstrated hypercholesterolemia in 20 of 30 nonfasting patients in a prior study of long-term toxicity of chemotherapy for germ cell tumors. The present study was designed to explore this phenomenon further. Seventeen unselected patients with biopsy-proven germ cell tumors, who underwent cisplatin-based chemotherapy and who had no prior history of cardiac disease nor known hypercholesterolemia, were studied. In addition to the standard staging tests, blood was drawn for a pretreatment fasting lipid screen, which included cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, and apolipoproteins A1, B, and (a). Repeat samples were drawn 24 hours after the administration of cisplatin and at intervals of 6 to 24 months after the completion of treatment. Seven of 17 patients (41%) had higher than desirable levels of total serum cholesterol and low-density lipoprotein cholesterol. Two of them had normal levels before treatment, four had preexisting hypercholesterolemia that increased further, and one patient had an elevated pretreatment level that did not alter. Absolute increases in serum cholesterol were noted in 14 of 17 patients. No consistent patterns of change beyond the reference ranges were found for other serum lipids. We have confirmed our initial observation that serum cholesterol increases in patients who received cisplatin-containing chemotherapy regimens for germ cell tumors. Further studies will be necessary to define whether other lipid abnormalities occur and the biologic significance of these findings.


Systemic chemotherapy of brain metastases from small-cell lung cancer: a review. For decades the treatment of choice in small-cell lung cancer (SCLC) with brain metastases has been corticosteroids and radiotherapy (RT) because of a presumed lack of penetrance of cytostatic agents into parenchymatous brain metastases. In recent years, several reports have appeared on radiologic and clinical responses to systemic chemotherapy without additional RT in patients with metastatic SCLC in the brain. We reviewed the literature and focused on the methodologic aspects in comparison with RT data. We reviewed 12 patient series that included 116 patients and were published between 1981 and 1990. The overall brain response to chemotherapy without irradiation in patients with intracranial metastases at diagnosis was 76%, whereas the response rate of brain relapses was 43%. We conclude that intracranial metastases from SCLC seem to respond to chemotherapy as readily as other metastatic locations of SCLC do. Thus first-line cranial irradiation probably should be applied routinely only in cases of delayed brain metastases. Whether consolidating cranial RT should be given after a few courses of initial chemotherapy in SCLC patients with brain metastases at diagnosis is unclear and warrants a randomized evaluation.


Pre-radiation chemotherapy in glioma patients with poor prognostic factors. Nineteen patients in an age group from 56-67 years (mean age 62.5 years) with histologically verified glioblastoma multiforme were treated with chemotherapy consisting of two cycles of oral CCNU, intravenous vincristine and oral procarbazine prior to radiation therapy. Ten of the patients had stable disease, monitored by CT scan and neurological examination, and received whole brain radiation. The median survival was 12 months. Nine patients who had progressive disease during chemotherapy did not receive radiation treatment and were put on palliative treatment with dexamethasone. This group had a median survival of 3 months. The median survival in all of the 19 patients who entered the study was 9 months which was comparable to the survival of 56 patients with glioblastoma multiforme who, in a retrospective study, received post-operative radiotherapy. The most important factor predicting survival was steroid-dependency after surgery.


Clinicopathological evaluation of 78 astrocytomas in Taiwan with emphasis on a simple grading system. The grading systems of astrocytic tumors have long been the subject of controversy. A simple, objective and effective grading method is urgently needed for the evaluation of prognosis and the planning of treatment. This study investigated the relationship of clinical prognostic factors to the grading method of Daumas-Duport. This method determines the grade of tumor based on the presence or absence of four morphological criteria: nuclear atypia, mitosis, endothelial proliferation, and necrosis. A total of 143 astrocytic tumors were reviewed and screened, of which 65 ordinary and 13 pilocytic astrocytomas were selected for grading and comparison. Among ordinary astrocytomas, the grading method distinguished 9.2% grade 1, 26.2% grade 2, 36.9% grade 3, and 27.6% grade 4. At least 2-year follow-up was available on all surviving patients. Median survival was 57, 32, 12.5, and 8 months in grades 1, 2, 3, and 4 tumors, respectively. By a multiple regression model and analysis of variance, grade is significantly associated with survival (total regression coefficient r = 0.711). Age lost its significance on survival after multiple regression analysis. Sex, location, and surgical procedure were all unrelated to survival after regression. The age distribution and survival of patients with pilocytic astrocytomas revealed that this is a distinct disease entity and should not be admixed with ordinary astrocytomas in a grading scheme.


Proliferative potential and outcome in pediatric astrocytic tumors. In 43 pediatric patients (29 male, 14 female) with primary astrocytic tumors of the central nervous system (CNS), the correlation was evaluated between outcome and proliferative potential, measured by the bromodeoxyuridine (BrdU) labeling index (LI). Twenty-five patients had low-grade gliomas, 13 had anaplastic gliomas, and 5 had glioblastomas multiforme (GBM). All patients underwent surgery; 37 also had chemotherapy, radiation therapy, or both. The median BrdU LIs were less than 1% (range 0-9.3%) in low-grade gliomas, 2.3% (range 0-21.2%) in anaplastic gliomas, and 7.7% (range 0-21.3%) in GBM. Seven of eight patients with BrdU LI greater than 5% have died (median survival 29 weeks). Median survival has not been reached in patients with BrdU LI less than 1% (19/22 alive) or between 1% and 5% (12/13 alive) after median follow-up periods of 165 and 120 weeks, respectively. A high BrdU LI correlated with short survival (p = 0.0001); the association between malignant histology and short survival was weaker (p = 0.019). BrdU LI is therefore a significant predictor of outcome in patients with primary CNS astrocytomas and appears to be a stronger predictor than histology in patients with low-grade and anaplastic gliomas. More patients need to be studied to confirm these preliminary observations.


Carboplatin, vinblastine and mitomycin-C in the treatment of non-small cell bronchogenic carcinoma. Thirty patients with advanced non-small cell lung carcinoma were treated with carboplatin, vinblastine and mitomycin-C. Objective tumor regression was noted in 6 patients. Toxicity of this combination was moderate.


Kinetic and pharmacological properties of low voltage-activated Ca2+ current in rat clonal (GH3) pituitary cells. 1. Low voltage-activated (LVA) Ca2+ current in clonal (GH3) pituitary cells was studied with the use of the whole-cell recording technique. The use of internal fluoride to facilitate the rundown of high voltage-activated (HVA) Ca2+ current allowed the study of LVA current in virtual isolation. 2. In 10 mM [Ca2+]o, detectable LVA current begins to appear at about -50 mV, with half-maximal activation occurring at -33 mV. The time course of activation was best described by a Hodgkin-Huxley expression with n = 3, suggesting that at least three closed states must be traversed before channel opening. 3. Deactivation was found to vary exponentially with membrane potential between -60 and -160 mV, indicating that channel closing is rate-limited by a single, voltage-dependent transition. 4. Onset and removal of inactivation between -40 and -130 mV were best described by the sum of two exponentials. Between -80 and -130 mV, both components of removal of inactivation showed little voltage dependence, with time constants of approximately 200-300 ms and 1-2 s. At membrane potentials above -40 mV, a single component of inactivation onset was detected. This component was voltage independent between -20 and +20 mV (tau = 22 ms). Thus inactivation of LVA current is best described by multiple, voltage-in-dependent processes. 5. Significant inactivation of LVA current occurred at -65 mV without detectable macroscopic current. This suggests that inactivation is not strictly coupled to channel opening. 6. Peak LVA current increased with increasing [Ca2+]o, with saturation approximately 50 mM. The Ca(2+)-dependence of peak LVA current was reasonably well described by a single-site binding isotherm with half-maximal LVA current at approximately 7 mM. 7. LVA current in GH3 cells was largely resistant to blockade by Ni2+. The relative potency of inorganic cations in blocking GH3 LVA current was (concentrations which produced 50% block): La3+ (2.4 microM) greater than Cd2+ (188 microM) greater than Ni2+ (777 microM). 8. Several organic agents, including putative LVA blockers, HVA current blockers and various anesthetic agents, were tested for their ability to block LVA current. The concentrations that produced 50% block are as follows: nifedipine (approximately 50 microM), D600 (51 microM), diltiazem (131 microM), octanol (244 microM), pentobarbital (985 microM), methoxyflurane (1.41 mM), and amiloride (1.55 mM). Phenytoin and ethosuximide produced 36 and 10% block at 100 microM and 2.5 mM, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)


Synaptic proliferation in the motor cortex of adult cats after long-term thalamic stimulation. 1. One of the hypotheses for information storage in the CNS postulates the induction of structural changes in synaptic circuits. This postulate predicts that behavioral experiences produce changes in neural activity that subsequently induce synaptogenesis in the mature CNS. Available data indicate that the establishment of engrams for novel motor acts may involve alterations of synaptic interactions within the primary motor cortex. The present study examines the hypothesis that patterns of synaptic circuitry and of synaptic activation are rearranged after enhanced neural activity in pathways projecting to the motor cortex. 2. Electrodes implanted in the ventroposterolateral (VPL) nucleus of the thalamus were used for long-term stimulation (20 microA, 4 days) of afferents to the motor cortex in freely behaving, adult cats. This stimulation primarily affected corticocortical inputs from the somatosensory cortex (area 2) to area 4 gamma of the motor cortex. Electron microscopy and stereological procedures were used to compare the numerical density (Nv) of various types of synapses in layers II/III of the stimulated (experimental) motor cortex with the Nv of the corresponding synapses in the contralateral (control) hemisphere. 3. Long-term stimulation produced a significant increase (25.6%) in synaptic Nv in experimental motor cortex. This increase was due primarily to an increase in the Nv of asymmetrical synapses with dendritic spines. The numbers of symmetrical synapses, and of asymmetrical synapses with dendritic shafts, were not affected by long-term stimulation. 4. Synaptic active zones [calculated by measuring the lengths of postsynaptic densities (PSDs)] were significantly longer in experimental motor cortex. Lengthening of PSDs occurred selectively in asymmetrical synapses with dendritic shafts (28% increase). 5. The Nv of synapses having perforations in their PSDs (perforated synapses) was significantly higher in experimental hemispheres. Also increased was the incidence of synapse-associated polyribosomes, which are most commonly found at the base of dendritic spines. An increase in the number of perforated synapses and of polyribosomes are both morphological hallmarks of synaptogenesis. 6. The percentages of synapses having different curvatures (i.e., presynaptically concave, convex, or flat) were similar in experimental and in control motor cortex.(ABSTRACT TRUNCATED AT 400 WORDS)


Characterization of voltage-dependent calcium currents in mouse motoneurons. 1. Calcium channel currents were measured with the whole-cell patch clamp technique in cultured, identified mouse motoneurons. Three components of current were operationally defined on the basis of voltage dependence, kinetics, and pharmacology. 2. Test potentials to -50 mV or greater (10 mM external Ca2+) elicited a low-voltage activated T-type current that was transient (decaying to baseline in less than 200 ms) and had a relatively slow time to peak (20-50 ms). A 1-s prepulse to -45 mV produced approximately half-maximal inactivation of this T current. 3. Two high-voltage activated (HVA) components of current (1 transient and 1 sustained) were activated by test potentials to -20 mV or greater (10 mM external Ca2+). A 1-s prepulse to -35 mV produced approximately half-maximal inactivation of the transient component without affecting the sustained component. 4. When Ba2+ was substituted for Ca2+ as the charge carrier, activation of the HVA components was shifted in the hyperpolarizing direction, and the relative amplitude of the transient HVA component was reduced. 5. Amiloride (1-2 mM) caused a reversible, partial block of the T current without affecting the HVA components. 6. The dihydropyridine agonist isopropyl 4-(2,1,3-benzoxadiazol-4-yl)-1,4-dihydro-2,6-dimethyl-5-nitro-3- pyridine-carboxylate [(+)-SDZ 202-791, 100 nM-1 microM)] shifted the activation of the sustained component of HVA current to more negative potentials and increased its maximal amplitude. Additionally, (+)-SDZ 202-791 caused the appearance of a slowed component of tail current.(ABSTRACT TRUNCATED AT 250 WORDS)


Ammonium ions abolish excitatory synaptic transmission between cerebellar neurons in primary dissociated tissue culture. 1. Transmitter glutamate is thought to be derived from glutamine via cleavage by glutaminase. NH+4 inhibits glutaminase. Therefore the decrease of glutamatergic excitatory synaptic transmission by NH+4 was thought to be due to the inability of glutamine to serve as precursor for glutamate. However, in cat spinal cord, NH+4 abolished excitatory synaptic transmission by a conduction block for action potentials in presynaptic terminals. The conduction block prevented inferences as to the effects of NH+4 on the availability of glutamate for synaptic transmission. This study reexamines the effects of NH+4 on glutamatergic excitatory synaptic transmission in cerebellar neurons in tissue culture. 2. Whole-cell patch voltage-clamp recordings were obtained from presumed Purkinje cells. Extracellular stimulation of presumed granule cells produced mono- and polysynaptic excitatory postsynaptic currents (EPSCs). In addition, presumed Purkinje cells showed spontaneous EPSCs that occurred independently of the addition of tetrodotoxin (TTX) or Cd2+ to the extracellular solution. 3. NH+4 (5-10 mM) abolished evoked mono- and polysynaptic EPSCs without abolishing spontaneous EPSCs and without significant effects on action currents in the Purkinje cell soma. 4. Increase of K+ in the extracellular solution to 10-12 from 5 mM abolished evoked EPSCs without abolishing spontaneous EPSCs and without significant effects on action currents in the Purkinje cell soma. 5. Mixtures of NH+4 and K+, with each ion in a concentration insufficient to affect evoked EPSCs when given alone, abolished evoked EPSCs when the sum of NH+4 and K+ exceeded 10-12 mM. 6. Increase of intracellular pH by trimethylamine had no effect on evoked and spontaneous EPSCs.(ABSTRACT TRUNCATED AT 250 WORDS)


Successive infection of coxsackievirus B3 and encephalomyocarditis virus: an animal model of chronic myocarditis. Successive infection of coxsackievirus B3 and encephalomyocarditis virus was investigated as a disease model of chronic myocarditis. Four-week-old C3H/He mice were inoculated with coxsackievirus B3 and then inoculated with encephalomyocarditis virus at 8 weeks old. The hearts were evaluated on histopathological changes compared with those of non-infected mice and mice infected with either virus alone. At 10 weeks old, the hearts of the mice infected successively with both viruses showed co-existence of fibrosis surrounding calcified lesions and marked cellular infiltration with myocardial necrosis. These findings resembled chronic active myocarditis in humans, unlike the lesions due to either virus alone. At 12 weeks old, the hearts of all the infected mice showed fibrosis with scarce cellular infiltration. The successively infected hearts also showed a significantly higher heart weight to body weight ratio than that of the non-infected control mice, and localized wall thinning in the damaged regions. Thus, we conclude that successive infection additively causes myocardial damage that resembles chronic myocarditis and may produce a heart condition similar to dilated cardiomyopathy.


Selective decontamination of the digestive tract contributes to the control of disseminated intravascular coagulation in severe liver impairment. A premature neonate with severe Coxsackie B1 hepatitis acquired in utero developed disseminated intravascular coagulation a few days after birth. The neonate did not respond to conventional treatment. Eradication of aerobic gram-negative bacilli (Enterobacteriaceae) from the gut with oral nonabsorbable polymyxin E and tobramycin (selective decontamination of the digestive tract) was followed by clinical improvement; disseminated intravascular coagulation was controlled. After an unstable convalescence, the neonate recovered and was discharged in good general condition. A correlation between oral feeding, gut carriage of Enterobacteriaceae, fecal endotoxin pool, and platelet counts was observed. The eradication of gut carriage of aerobic gram-negative bacilli was associated with a significant decrease of the intestinal endotoxin pool and paralleled the recovery from thrombocytopenia. Selective decontamination is discussed as a method of possible value for controlling systemic endotoxin-induced symptoms in the critically ill with intestinal endotoxemia.


A basis for resistance of Blastomyces dermatitidis killing by human neutrophils: inefficient generation of myeloperoxidase system products. The mechanism by which the yeast form of Blastomyces dermatitidis resists killing by human peripheral blood polymorphonuclear neutrophils (PMN) was investigated. The metabolic products of the oxidative burst generated during the interaction of PMN and B. dermatitidis or Candida albicans were detected by lucigenin- or luminol-enhanced chemiluminescence (CL). Interaction of PMN and C. albicans resulted in luminol-enhanced CL 100-fold greater than that generated by PMN and B. dermatitidis. This correlated with killing of C. albicans and resistance of B. dermatitidis. Since B. dermatitidis and PMN interactions resulted in significant lucigenin-enhanced CL, deficient luminol CL was not due to a lack of products from the NADPH oxidase system. Killed B. dermatitidis cells at 37 degrees C were more efficient than live cells in stimulating PMN for luminol-enhanced CL; however, only fragmented B. dermatitidis cells elicited luminol-enhanced CL equivalent to that of C. albicans. Since lysates of PMN were active in a cell-free hydrogen peroxide-peroxidase-halide system, resistance of B. dermatitidis to PMN was not due to a defect in PMN peroxidase. Taken together, these findings indicate that resistance of B. dermatitidis to killing by PMN results from inefficient generation of products from the peroxidase-dependent PMN microbicidal system.