Cytomegalovirus and pregnancy.

Cytomegalovirus and pregnancy. Cytomegalovirus remains the most common congenital infection worldwide, with approximately 1% of all newborns infected in utero. Of those infected in utero, approximately 10% will have signs and symptoms of cytomegalovirus infection at birth and develop sequelae, especially mental retardation, hearing deficit, or both. Recent data indicate that more than 90% of symptomatic infections or infections causing sequelae occur following a primary maternal infection during pregnancy. The overall risk of delivering an infant who will develop significant handicaps following a primary maternal infection is between 10% and 20%. Between 1% and 2% of seronegative women may acquire a primary cytomegalovirus infection during pregnancy, but seronegative women at high risk include day-care workers, who have a 10% to 20% annual infection rate, and the seronegative mothers of infected children under 2 years of age, 50% of whom will acquire cytomegalovirus annually from their children. Adolescents are another group who may have a high infection rate during pregnancy. Although a cytomegalovirus vaccine is still many years from introduction, these observations strengthen the need and feasibility for a cytomegalovirus vaccine. Pending vaccine development and evaluation, several possible strategies for intervention to prevent primary infection for high-risk pregnancies are suggested.


Production of activated species of oxygen during the chromate(VI)-ascorbate reaction: implication in carcinogenesis. The reaction of chromate and ascorbate in a 1:1 molar ratio at pH 7.4 and 37 degrees C produces a Cr(V) signal observable by EPR at g = 1.980. When this reaction is carried out in aerated media and in the presence of formate, carboxylate radicals (COO.-) can be trapped as DMPO-COO.- spin adducts (DMPO, 5,5-dimethyl-1-pyrroline N-oxide). The use of a known complexant of Cr(V), 2-ethyl-2-hydroxybutyric acid, produces a different Cr(V) signal at g = 1.978 and a decrease of the DMPO-COO.- signal. Hydroxyl radicals are not detected in the media. The oxidizing behavior is suggested to be produced by activation of molecular oxygen present in the reaction mixture.


Herpes simplex virus infections.

Herpes simplex virus infections. This review discusses current reports on herpes simplex virus infections as they relate to the use of laboratory testing, infections in the neonate, herpes simplex virus association with human immunodeficiency virus infection, and updating the current therapy and management of genital herpes. Findings over the past year are important in the clinical management of patients with genital herpes. All health care workers who manage patients with genital herpes need to know the limitations of serologic testing. Current information suggests that serologic commercial testing that is most commonly available cannot discriminate between infections caused by herpes simplex virus type 1 and type 2. Laboratory methods still rely on culturing herpes simplex virus in living cells in vitro. However, the availability of monoclonal antibodies allows for rapid assays for the confirmation of cultured herpes simplex virus. In addition, assays have been developed and tested, suggesting that perhaps antigen-detection systems may be available that could replace culturing the virus in living cells. New information on neonatal herpes points out the predictors of morbidity and mortality in newborns who contract herpes within the first few weeks of life. Information concerning asymptomatic shedding in labor will provide the clinician with a better understanding of this disease entity in the pregnant woman. Several studies have confirmed that herpes simplex virus infection is a risk factor for developing human immunodeficiency virus infection. A new study clearly shows that treatment using daily acyclovir therapy over a prolonged period of time can control and may modify herpesvirus infection.


Effects of parathyroid hormone on cyclic AMP-formation and cytoplasmic free Ca2+ in the osteosarcoma cell line UMR 106-01. The effects of parathyroid hormone (PTH) on cytoplasmic free Ca2+ (Cai2+) and cAMP-formation were investigated in the rat osteosarcoma cell line UMR 106-01. In fura-2 loaded adherent single cells bPTH 1-34 (10 nM - 1 microM) induced a rapid transient increase in Cai2+ in 11% of the studied cells. In fura-2 tracings from UMR 106-01 cells in suspension, bPTH 1-34 (0.1 microM) induced a transient increase in Cai2+ in 20% of the experiments. The transient increase in Cai2+ seen in suspensions of cells was not abolished by addition of EGTA (2.5 mM) prior to challenge with PTH, suggesting that the increase in Cai2+ was derived from intracellular stores. A marked rapid increase in cAMP-formation was observed in all experiments with cells in suspension, also in the experiments where PTH did not affect Cai2+. These data show that PTH causes a release of Ca2+ from intracellular stores in a small percentage of osteosarcoma UMR 106-01 cells, and that PTH is capable of inducing an increase in cAMP-formation without affecting Cai2+ in osteoblasts.


Activation of the carcinogen N-hydroxy-N-(2-fluorenyl)benzamide via chemical and enzymatic oxidations. Comparison to oxidations of the structural analogue N-hydroxy-N-(2-fluorenyl)acetamide. Chemical or enzymatic oxidations of the carcinogen N-hydroxy-N-(2- fluorenyl)benzamide (N-OH-2-FBA) were investigated under the conditions facilitating one-electron oxidation or oxidative cleavage of N-hydroxy-N-(2-fluorenyl)acetamide (N-OH-2-FAA). HPLC methods were developed for separation and quantitation of the above hydroxamic acids and their respective oxidation products. To identify the products of oxidation of N-OH-2-FBA, N-(benzoyloxy)-2-FBA (N-BzO-2-FBA) was synthesized and shown to undergo ortho rearrangement to 1- and 3-BzO-2-FBA. Oxidation of N-OH-2-FBA (4.88 mM) with alkaline K3Fe(CN)6 in benzene was complete and yielded equimolar amounts of 2-nitrosofluorene (2-NOF) and the ester (chiefly N-BzO-2-FBA), indicative of one-electron oxidation to nitroxyl free radical which undergoes bimolecular dismutation. However, one-electron oxidation of N-OH-2-FBA (30 or 10 microM) by horseradish peroxidase/H2O2 at pH 7 or myeloperoxidase/H2O2 at pH 6.5 yielded only approximately 10% as much product as N-OH-2-FAA (30 microM). The addition of 0.1 mM Br- +/- 0.1 M Cl- at pH 4 to 6.5 increased 2-NOF formation in MPO/H2O2-catalyzed oxidations. Simulations of these oxidations with HOCl/Cl- or HOBr/Br- showed that the latter was more efficient, converting N-OH-2-FAA almost completely and less than or equal to 62% of N-OH-2-FBA to 2-NOF. The amounts of the ester (N- and o-BzO-2-FBA), which by itself did not contribute to 2-NOF formation or significant substrate regeneration, indicated that approximately 10% of 2-NOF originated from one-electron oxidation.(ABSTRACT TRUNCATED AT 250 WORDS)


Gene mapping in experimental hypertension. In the rat, the results of genetic linkage studies by "candidate" gene or "positional mapping" approaches have suggested that DNA sequences that regulate blood pressure may be located in the vicinity of the kallikrein gene family on chromosome 1, the gene for angiotensin-converting enzyme on chromosome 10, the renin gene on chromosome 13, and the major histocompatibility complex on chromosome 20. Some studies have also suggested that blood pressure regulatory genes may be located on the sex chromosomes. Pending the results of confirmatory studies, these experiments should be interpreted with caution. However, with confirmation of these studies, it should be possible to create a variety of new animal models that will provide excellent opportunities for investigating the molecular, biochemical, and physiologic determinants of high blood pressure. In addition, in genetic studies in humans with essential hypertension, it may be worthwhile to target chromosome regions that are homologous to those implicated in linkage studies of hypertension in rodents. By narrowing the focus on selected areas of the genome, experimental linkage studies in the rat may also be used to guide the detailed molecular approaches ultimately required to identify the specific DNA sequence alterations that give rise to increased blood pressure.


Characterization of cholinergic receptors in Madin-Darby canine kidney cells. Muscarinic-type cholinergic receptors coupled to the phosphoinositide (PI) second messenger system are reported to be present in the inner medullary collecting duct cells. Madin-Darby canine kidney (MDCK) cells have several characteristics of collecting duct cells and have been shown to respond to muscarinic agonists. To determine if MDCK cells have PI-coupled muscarinic receptors, the radioligand binding and the effects of cholinergic agonists and antagonists on PI hydrolysis in MDCK cells were studied. The specific binding of [3H]1-quinuclidinyl benzilate ([3H]QNB), a muscarinic antagonist, to MDCK cell membranes had a Kd = 88 +/- 7 pM and a Bmax = 1464 +/- 88 fmol/mg of protein. The displacement of [3H]QNB from MDCK cell membranes by various cholinergic antagonists and agonists showed the order of potency: atropine greater than 4-diphenylacetoxy N-methylpiperidine (4-DAMP) greater than p-fluorohexahydrosiladifenidol greater than pirenzepine greater than metoctramine greater than arecoline greater than carbachol. The cholinergic agonists carbachol and arecoline stimulated PI hydrolysis in a concentration-dependent manner with an EC50 of 3.7 and 1.3 microM, respectively. Muscarinic antagonists abolished carbachol-stimulated PI hydrolysis in the following order of potency: atropine greater than 4-DAMP greater than pirenzepine much greater than methoctramine. The order of potency of muscarinic antagonists is consistent with the characteristics of the M3 subtype of muscarinic receptors. It is concluded that: (1) muscarinic receptor density in MDCK cells is 50 times higher than that in inner medullary collecting duct cells; (2) muscarinic receptors in MDCK cells are putative M3 subtype; and (3) muscarinic receptors in MDCK cells are functionally coupled to the PI second messenger system. This intracellular messenger system may, at least, be partially responsible for the action of cholinergic agonists in these cells and in the kidney.


Effects of angiotensin II and arginine vasopressin on F-actin content of cultured mesangial cells. The actin cytoskeleton of mesangial cells (MC) plays an important role in the contractile response to agonists as well as in the endocytosis of macromolecules. A quantitative study of the F-actin content of MC by the rhodamine-phalloidin binding assay was carried out. Angiotensin II (ANG II) (10(-6) M) significantly increased the F-actin content of MC by 30 min and at later time periods, with increases ranging from 31 to 46%. Arginine vasopressin (10(-8) M) produced a transient decrease of F-actin content of MC at 30 s but then significantly enhanced the F-actin content at later time periods. There was no change in total actin and protein content of MC at 30 min in the presence of either agent. Thus, the increase in F-actin is related to a shift in the G- to F-actin ratio and not to the synthesis of new F-actin. Because the incubation of MC with 1 (5-isoquinolinylsulfonyl)-2-methylpiperazine, an inhibitor of protein kinase C, did not attenuate the ANG II-induced increase in the F-actin content of MC, the shift does not appear to be mediated by the activation of protein kinase C. The removal of external calcium did not prevent the increase in F-actin. Dibutyryl cAMP (5 x 10(-4) M), a smooth muscle cell and MC relaxant, did not alter the F-actin content in MC, and 10(-5) M cytochalasin B significantly lowered F-actin content.(ABSTRACT TRUNCATED AT 250 WORDS)


Distribution of TNF endogenously induced by various immunopotentiators and Lactobacillus casei in mice. Intravenous administration of heat-killed Lactobacillus casei YIT 9018 (LC) elicited endogenous cytotoxic factor (CF) production in ICR mice, peaking in serum after 2 h and declining gradually to basal level at 23 h. The endogenous CF production was significantly enhanced by priming with high molecular-weight lignins and glucans, but not by phenylpropenoid precursors or partially hydrolyzed products of glucans. The extent of stimulation of CF production by these priming agents was positively related to that of tumor necrosis factor (TNF) production, as judged by enzyme-linked immunosorbent assay. Endogenously produced TNF was concentrated more in liver, lung and intestine, as well as in serum, than in other organs. Histochemical examination revealed a significant increase in the number and swelling of Kupffer cells and sinusoidal endothelium in the liver of the treated mice.


Effect of dietary fiber on mammary tumorigenesis, estrogen metabolism, and lipid excretion in female rats. We previously reported that supplementary dietary wheat bran significantly reduced the incidence of N-nitrosomethylurea (NMU) induced mammary tumors in rats fed a high fat (HF) diet and reduced to a lesser extent the incidence in rats fed a low fat (LF) diet compared to their unsupplemented controls. Using the same cohort of experimental animals, we here report the results of biochemical analyses designed to investigate the effect of supplemental dietary fiber on estrogen metabolism and lipid excretion. Serum, hepatic tissue, urine, and feces were obtained from rats which had been fed a HF (23.5% corn oil) diet, a HF plus fiber (HF + F, 10% soft white wheat bran, SWWB) diet, a LF (5.0% corn oil) diet, or a LF plus fiber (LF + F) diet for 15 weeks beginning 3 days after a single dose of NMU. Our working hypotheses to explain how dietary fiber protects against mammary tumorigenesis were that fiber may: 1) act as an antiestrogen; 2) decrease circulating estrogens; 3) alter the enterohepatic recirculation of estrogens; and 4) physically bind to lipid and remove it in the feces. Therefore, various indices of estrogen metabolism were assessed including: 1) circulating estradiol (E2) and progesterone; 2) hepatic estrogen receptor (ER) protein; 3) excretion of estrogen in the urine and feces; 4) the in vitro estrogen binding properties of SWWB; 5) fecal lipid content; and 6) the in vitro lipid binding capacity of SWWB. Serum 17 beta-estradiol and progesterone remained unchanged as did hepatic cytosolic (cER) and nuclear (nER) estrogen receptor protein content, in the fiber supplemented groups compared to their respective controls.(ABSTRACT TRUNCATED AT 250 WORDS)


Studies on the preventive action of neurotensin on dexamethasone-induced adrenocortical atrophy. The effects of neurotensin (NT) and ACTH on the dexamethasone (Dx)-induced atrophy of the rat adrenal cortex (120 micrograms Dx/rat/day for 4 days) were investigated. NT at a dose of 8 micrograms/rat/day for 2 days prevented Dx-induced adrenal atrophy, and a similar effect was exerted by 10 micrograms/rat/day of ACTH for 2 days. Lower doses of NT were ineffective. ACTH markedly enhanced 3H-thymidine incorporation by adrenal slices, while NT did not. Neither ACTH nor NT had any effect on the number of metaphases per section of the adrenal gland. These findings indicate that NT, like ACTH, prevents Dx-induced adrenocortical atrophy, and that this effect does not depend, as does that of ACTH, upon the stimulation of proliferation of adrenocortical cells.


Regulation of platelet clearance receptors for atrial natriuretic peptide in diabetic nephropathy. The findings that circulating levels of atrial natriuretic peptide (ANP) are elevated in diabetic nephropathy and that the magnitude of the urinary excretion rate of cGMP in response to hypervolemia-induced ANP release is blunted have recently been reported. The purpose of this study was to determine whether these abnormalities are associated with the down-regulation of ANP receptors. Because biologically active (A) ANP receptors in the kidney are inaccessible, we have examined the binding of (125I alpha)ANP to clearance (C) receptors on platelets obtained from patients with diabetic nephropathy. Scatchard analysis revealed a reduction in such binding sites compared with those in healthy controls: 12 +/- 2 versus 19 +/- 2 per platelet, respectively (P less than 0.001). The dissociation constant, Kd, was higher: 66.7 +/- 33.1 versus 38.5 +/- 11 pM, respectively (P less than 0.02). The reduced number of receptors could reflect the down-regulation of ANP C receptors in response to an elevation of plasma levels of ANP, the median value of which was 10.6 versus 7.1 pmol/L in controls (P less than 0.05). Alternatively, the findings could represent a primary adaptation by C receptors to elevate plasma ANP levels and increase the availability of the peptide to biologically active renal receptors. The latter adaptation would serve to mitigate the sodium retention that attends diabetic nephropathy.


Sequential tubular cell and basement membrane changes in polycystic kidney disease. Tubular basement membrane (BM) changes (dysmorphogenesis), cell proliferation, and fluid accumulation related to the altered location of Na,K-ATPase are purported essential key events in the development and progression of renal cysts. These changes were assessed daily in Phenol II (2-amino-4-hydroxyphenyl-5-phenyl thiazole)-treated rats, which rapidly develop marked and progressive cystic change of all collecting tubules (CT). At Day 1, 12% of CT were cystic and their BM were thickened severalfold. At Day 4, 30% of CT were cystic and their BM remained thickened. BM of cystic tubules showed decreased staining for heparan sulfate proteoglycan and increased staining for fibronectin. Proliferation, as determined by (3H)thymidine, incorporation, was not significant until Day 2 and involved cystic and noncystic tubular cells as well as interstitial cells. As cystic changes progressed, cell proliferation decreased. By immunohistochemistry, the altered location of Na,K-ATPase in epithelial cells lining cysts was primarily detected after Day 2 and consisted of focal loss from basal and/or lateral cell membranes and localization in the cell cytoplasm. Only rarely was Na,K-ATPase localized to the apical cell membrane. After the removal of Phenol II, cystic tubular cells, BM, and Na,K-ATPase returned to normal. Thus, in this model of polycystic kidney disease, initial cyst formation occurred in tandem with BM structural change whereas cell proliferation and altered location of Na,K-ATPase occurred after the appearance of cysts.


Ex vivo effects of SR 27417, a novel PAF antagonist, on rabbit platelet aggregation and [3H]-PAF binding. Pharmacodynamics of SR 27417, a novel, specific platelet-activating factor (PAF) antagonist was monitored with ex vivo PAF-induced platelet aggregation in the rabbit. Single per os administration of SR 27417 (5 mg/kg) resulted in complete inhibition of this aggregation for at least 3 days. The magnitude of this inhibitory effect was dose-dependent with a maximum effect 1-3 h after oral administration. IC50 values for PAF-induced platelet aggregation were 80, 35, 50 and 1250 micrograms/kg, 1, 3, 24 and 72 h after oral intake of SR 27417 respectively. This effect was irreversible in nature since it could not be overcome by prolonged incubation of platelets isolated from treated animals in plasma from controls or in buffer. Examination of [3H]-PAF binding to washed platelets isolated 5 min after i.v. administration of increasing concentrations of SR 27417 revealed a competitive-type of inhibition whereas 24 h after p.o. administration, SR 27417 antagonized [3H]-PAF binding in a non-competitive manner.


Characterization of platelet-activating factor induced superoxide anion generation by guinea-pig alveolar macrophages. Guinea-pig alveolar macrophages (AM) exhibited a concentration dependent superoxide anion (.O2-) generation as measured by means of lucigenin-chemiluminescence (CL) in response to platelet-activating factor (PAF) in the range of 1 nM to 100 nM. PAF effects on .O2(-)-generation were specific to the form of PAF that is biologically active in most systems; lyso-PAF had no effect. The CL-response was inhibited following incubation with EDTA (IC50: 859 microM), the intracellular Ca(2+)-antagonist TMB-8 (IC50: 73 microM), or the calmodulin antagonists W-7 (IC50: 13 microM) and trifluoperazine (IC50: 14 microM) indicating the involvement of Ca2+ in the signal transduction pathway. Increasing the intracellular cAMP-levels by PGE2 or forskolin resulted in an inhibition of the CL-response, whereas the beta-adrenoceptor agonist salbutamol showed no effect. On the other hand phosphodiesterase inhibition by IBMX (10 microM: 25%) or zardaverine (10 microM: 29%) also resulted in a transient inhibition of the CL-response. Protein kinase C (PKC) seemed not to be involved in the signal transduction, since the PKC-inhibitors staurosporine, H-7 and D-sphingosine were inactive. In contrast, the PAF receptor antagonists WEB-2086 (IC50: 700 nM) and WEB-2170 (IC50: 176 nM) exerted a strong inhibitory activity. The antiallergic/antiasthmatic drug azelastine also reduced the PAF induced CL-response (IC50: 12 microM), whereas the other antiallergic/antiasthmatic compounds showed almost no inhibition.


Inhibition of platelet arachidonic acid liberation by endothelium-derived relaxing factor (EDRF) as studied with sin-1, a nitric oxide generating drug. Evidence for calcium-dependent and calcium-independent mechanisms. In order to investigate possible effects of endothelium-derived relaxing factor (EDRF or NO.) on platelet phospholipase A2 activity, human platelets labelled with [3H]arachidonic acid ([3H]AA) were stimulated with thrombin (0.5 IU/ml) in the absence or in the presence of sin-1, a vasodilator and platelet inhibitor releasing NO. by spontaneous decomposition at physiological pH. Sin-1 promoted a dose-dependent inhibition of [3H]AA liberation, which was identical in the presence or in the absence of 1 mM Ca2+ in the external medium, suggesting that a reduction of Ca2+ influx was not responsible for this metabolic effect. Using fura-2 as a fluorescent Ca2+ indicator, sin-1 was found to inhibit similarly both Ca2+ influx and Ca2+ mobilization, the latter effect being directly related to a reduction of inositol 1,4,5-tris phosphate production by phospholipase C. However, comparison of cytoplasmic free calcium concentrations ([Ca2+]i) and of [3H]AA liberation attained by platelets treated under various experimental conditions indicated the lack of a direct relationship between [Ca2+]i and platelet phospholipase A2 activity. The effects of sin-1 on [3H]AA liberation could be reproduced by a membrane-permeant analogue of cGMP (8-bromo cyclic GMP), with no evidence of additional effects of sin-1 under these conditions. These data bring further support to the view that Ca2+, although being a necessary cofactor of intracellular phospholipase A2, is not the only regulator of the enzyme. Owing to the multiple effects of this drug on various events involved in membrane-signal transduction (Ca2+ influx, phospholipase C and phospholipase A2 activation), it is suggested that sin-1 inhibits platelet function at an early step of signal transduction, probably by elevating cGMP through a direct effect of NO. on cytosolic guanylate cyclase.


Post-transient ischemia increase in ubiquitin conjugates in the early reperfusion. Triton X-100-, digitonin- and urea-insoluble ubiquitin conjugates (UC) in the mitochondrial fractions of the gerbil cortex and hippocampus were analysed. In the cortex, following 5 min of forebrain ischemia, UC increased at 30 min of reperfusion and returned to the control level at 24 h. Although chronological changes in UC in the hippocampus were similar to the cortex, a more sustained increase of UC was observed. Immunoblot analysis showed that UC above 50 kDa increased in both regions. The results indicate that insoluble UC increase in the early recovery stage after ischemic neuronal damages.


Hydroxyl radical formation in human gastric juice. The hydroxyl radical is the most potent free radical derived from oxygen, and has been implicated in damage caused to the gastroduodenal mucosa. The ability of human gastric juice to generate hydroxyl radicals has been investigated in 54 adults with endoscopically normal gastroduodenal mucosa and in 39 patients with chronic duodenal ulcer. Hydroxyl radical production was measured by the formation of formaldehyde from dimethylsulfoxide. Unlike other body fluids, this reaction could proceed without the extraneous addition of catalysts such as hydrogen peroxide (H2O2), ascorbate and iron. Measurement of H2O2, iron and ascorbate showed that these catalysts are already present in the gastric juice. There was no significant difference in the concentration of these components in gastric juice between normal subjects and patients with duodenal ulcer, except that H2O2 levels were slightly higher in duodenal ulcer patients. Although generation of free radicals has been investigated in other body fluids, this is the first reported case regarding the production of these active species in normal human gastric juice. Since hydroxyl production is not significantly enhanced in duodenal ulcer, we suggest that attention may be turned to mucosal antioxidant defences in this disease.


Prevention of kainate-induced excitotoxicity by a purine analogue. The effect of a systematically administered adenosine analogue upon neuronal damage induced by kanic acid has been examined using the binding of a peripheral benzodiazepine receptor ligand as a marker for the gliosis following neuronal death. Intraperitoneal (i.p.) injections of R-phenylisopropyladenosine (R-PIA), at a dose of 100 micrograms kg-1 or 25 micrograms kg-1 reduced substantially the hippocampal neurotoxicity induced by intraperitoneal kainate 100 mg kg-1. The effect of R-PIA was prevented by 8-phenyl-theophylline, confirming the involvement of a purine P1 receptor.


Development and characterization of a generalized gene tagging system for higher plants using an engineered maize transposon Ac. This report describes a series of transposon tagging vectors for dicotyledonous plants based on the maize transposable element Ac. This binary system includes the transposase (Ts) and the tagging element (Ds) on separate T-DNA vectors. Ts elements include versions in which transcription is driven either by the endogenous Ac promoter or by the cauliflower mosaic virus (CaMV) 35S promoter. Ds tagging element includes a gene conferring methotrexate (Mtx) resistance for selection and a supF gene to facilitate cloning of tagged sequences. The Ds element is flanked by a CaMV 35S promoter and the beta-glucuronidase (GUS) coding sequence so that GUS expression occurs upon excision of the element. We have transformed these Ts and Ds elements into tobacco and demonstrated that the Ts is functional with either promoter, and that the artificial Ds elements are capable of transposition. The amount of excision was found to depend upon both the individual Ts and Ds primary transformants used. Somatic excision of Ds was seen in up to 100% of progeny seedlings containing Ts and Ds. Germinal excision was detected in up to 48% of the progeny of plants containing both elements. Hence, this system can generate a sufficient number of events to be useful in gene tagging.


Expression of stress-responsive ubiquitin genes in potato tubers. The stress-induced expression of four different ubiquitin-encoding cDNAs was characterized in potato tuber tissue. The four clones exhibited differences in both structure and expression. The first cDNA encoded a single ubiquitin unit fused to an 80 amino acid ribosomal extension protein identical to the extension protein from tomato. Accumulation of the fusion transcript was induced by injury or ethylene, but not by heat shock. The three remaining ubiquitin cDNAs encoded polyubiquitins with 6 to 7 ubiquitin repeats. The first polyubiquitin gene was induced by injury, heat, or ethylene treatments. The second was induced also by injury or heat, with limited ethylene-dependent accumulation of transcript. Transcript levels of the third polyubiquitin gene were highest in control tubers and decreased markedly with injury, heat shock, or ethylene treatment. The data demonstrate the independent regulation of the different members of the ubiquitin gene family in response to stress and exogenous ethylene.


CD30/Ki-1-positive anaplastic large cell lymphoma preceded by Hodgkin's disease. A 59-year-old man was initially diagnosed as having Hodgkin's disease, nodular sclerosis type, and complete remission was achieved after combination chemotherapy. One year later, he developed a high fever and recurrence of the Hodgkin's disease was diagnosed. Salvage chemotherapy was ineffective, and the patient died. Autopsy specimens showed infiltration of lymphoma cells into multiple organs. Lymph nodes showed characteristics of non-Hodgkin's lymphoma, with expansion of anaplastic large cells; this differed from the histological features at initial diagnosis. Immunohistochemical staining was positive for CD30/Ki-1, but negative for CD15 (LeuM1). These findings were compatible with Ki-1 lymphoma, suggesting that this may be a case of CD30/Ki-1 lymphoma preceded by Hodgkin's disease and that a certain proportion of Ki-1 lymphomas and Hodgkin's disease may share the same cellular origin.


[The proton MR spectroscopy of intracranial tumors. The differential diagnostic aspects for gliomas, metastases and meningiomas]. Twenty-two patients with intracranial tumours were examined by MR images and in vivo proton-MR-spectroscopy. The changes of relative concentrations of NAA, PCr/Cr, Cho, and Ins were measured spectroscopically and the amount of these metabolites were related to different tumour groups. Analysis of the results has shown that the spectra from all the tumours differed from normal spectra. All cerebral tumours showed marked reduction of the Pcr/Cho quotient and the NAA/Cho quotient was also reduced. The Ins/Cho quotient for meningiomas and metastases was also lower than in normals; in gliomas of low malignancy the quotient was slightly raised and in gliomas of greater malignancy it was significantly higher than normal. The spectra of cerebral metastases showed unusual high lipid signals of 0.9 ppm and 1.25 ppm. The only common feature for meningiomas was marked reduction of NAA concentration. In summary, localised in vivo proton-MR-spectroscopy can be used clinically to obtain valuable information for the differential diagnosis of gliomas and intracerebral metastases.


[Effects of paradoxical sleep deprivation on the activity of opiate receptors isolated from synaptic membranes of the rat brain]. The specific binding of 3H-naloxone with opiate receptors isolated from brain synaptic membranes of control and paradoxical sleep deprived rats were studied. This extreme state was shown to reduce the naloxone-binding activity of synaptic membranes by 35% and isolated receptors by 25-28%. The values of Kd and Bmax were calculated for isolated opiate receptors at different stages of purification. Considerable decrease of 3H-naloxone binding sites density (2 times) in the isolated opiate receptors with simultaneous increase of their affinity (3-4,5 times) was found following 24 hours paradoxical sleep deprivation. These findings suggest development of fixed alterations in the structure and functions of integral receptor proteins under extreme influences.


[Effects of the membrane potential level on serotonin-induced contraction of the pulmonary artery smooth muscle in rabbits]. The effects of changes in membrane potential level on the electrical and contractile responses induced by serotonin (10(-6) mol/l) were investigated in muscle strips from rabbit main pulmonary artery using sucrose-gap technique. In spite of the fact that serotonin-induced depolarization did not exceed the threshold level for development of contraction, it was followed by a strong tonic contraction. Nearly a half of this contraction could be relaxed by an electrotonic hyperpolarization of the membrane. A week preliminary depolarization of the muscle cells resulted in an increase while a strong depolarization--in dramatic decrease of serotonin-induced contraction. Nifedipine effectively blocked potassium-induced, but not serotonin induced contraction. We suggest that in addition to voltage-operated and receptor operated Ca channels in vascular smooth muscle cell membrane there is a separate class of nifedipine-insensitive Ca channels operated by both serotonin receptor and membrane potential.


[Changes in lectin-induced chemiluminescence of neutrophilic granulocytes after irradiation of blood with helium-neon lasers]. Blood obtained from 33 healthy donors was irradiated with He-Ne laser. During this process the count of segmented neutrophils decreased, while the content of radioimmunologically determined leukotriene B4 and thromboxane B2 increased in the other neutrophils. Application of mannose-specific lectins (Con A, PSL) as inductors caused the increase, while application of other carbohydrate-specific lectins caused the decrease of luminol-dependent chemiluminescence in neutrophilic granulocyte suspension after the irradiation. As a result of direct laser effect on the blood cells some portion of the less resistant cells were eliminated from the blood flow, i.e. "rejuvenation" of the neutrophilic granulocyte population in the cells takes place.


[Effects of GABA antagonist-induced seizures on 3H-muscimol and 3H-diazepam binding in the rat striatum]. The binding of 3H-muscimol and 3H-diazepam to rat striatum membranes after picrotoxin- and bicuculline-induced seizures was characterized. No alteration in the maximal binding capacity (Bmax) of 3H-muscimol was observed. However, bicuculline produced a 27% decrease in Kd. Both picrotoxin and bicuculline increased the binding capacity of 3H-diazepam. Bicuculline produced a 86% increase in Kd. These results suggest that the GABA antagonists-induced seizures may modulate 3H-muscimol and 3H-diazepam binding in rat striatum.


[Potential-dependent Ca2+ channels and contractile function of the heart in toxic-infectious shock caused plague]. Influence of intravenous administration to rats of murine toxin of Y. pestis (1 mg/ml, LD100) on the number of potential-operated Ca(2+)-channels, alpha- and beta-adrenergic and M1-cholinergic receptors of plasma membranes and heart contractility function has been studied in rats. The number of Ca(2+)-channels in plasma membranes and contractility of heart decreased by 50% in 1 hour after the i.v. administration of toxin and further decreased up to the lethal end. During the agonal stage of the shock desensitization of beta-adrenergic receptors has been discovered, while alpha-adrenergic and M1-cholinergic receptors remained unchanged throughout the experiments.


[Extracellular pH, [K+] and synaptic transmission in the dorsal horn of spinal cord of rats in hypercapnia]. In rats anaesthetized with +-chloralose the changes in extracellular pH and K+ in spinal cord dorsal horn were studied using pH and K+ ion-selective electrodes. The addition of 20% CO2 into inhaled air decreased the basal level of [pH]0 from 7.35 +/- 0.01 to 6.78 +/- 0.09 pH units and increased the basal level of [K+]0 from 3.1 +/- 0.1 to 5.14 +/- 0.8 mM. Electrocutaneous supramaximal (10 mA) simulation of both hind paws with the frequency 30 and 100 Hz induced the shift in the concentration of H+ and K+ by 0.15-0.2 unit and 2-2.5 mM, respectively. Under hypercapnia this shift of pH decreased by 36.9 +/- 8.5% at 30 Hz frequency of electrocutaneous stimulation and by 41.9 +/- 6.1% at 100 Hz frequency. The K+ shift decreased by 11.5 +/- 1.3% and by 17.3 +/- 1.5% under similar conditions. Hypercapnia induced by addition of 20% CO2 into inhaled air decreased also the focal potential amplitude by 16.8 +/- 4%. Thus, hypercapnia induces the increase of [K+]0 and [pH]0 and the decrease of recorded indicators in response to electrocutaneous stimulation. Total depression of synaptic transmission and analgetic effect occur due to these changes of ions distribution.


[Dynamics of bioelectric activity of the brain and erythrocyte ultrastructure after intravenous infusion of sodium bicarbonate to oncologic patients]. 23 patients with malignant tumors of different location and histogenesis were investigated. There were no metastases in 9 cases. 10 patients had metastases in regional areas and 4--distant. The results were compared with those obtained in 4 patients with nonmalignant diseases. EEG, blood gases, plasma acid--base balance and ultrastructure of erythrocytes were explored before and after intravenous infusion of 4.2% sodium bicarbonate solution. The metabolic alkalosis induced amelioration of EEG, which was changed basically, the condense of pre-membrane layer disappeared or decreased in erythrocytes, and disaggregation of erythrocytes took place in cancer patients vs those with nonmalignant tumors. The results confirm the suggestion of generalized intracellular acidosis in malignant tumor patients. This acidosis can be temporarily avoided or diminished artificially by blood alkalosis.


[Adrenergic regulation of the contractility of the human and canine ureters]. Investigations on the isolated pieces from upper part of human ureters and upper and lower parts of dog ureters were performed. Isometric contractions during electrical stimulation in Lock solution (37 degrees C) and their changes after adrenomimetic drug and adrenoblocking drug perfusion were studied. The pieces of human ureters had more average weight and rest tension, but less isometric tension during rhythmic electrical stimulation and more pronounced hypersodium contracture in contrast to dog ureters. Adrenaline and noradrenaline augmented contractions of human and dog ureters. Isadrin increased the contractility of the upper parts of human ureters and the lower parts of dog ureters, but decreased--the upper segments of dog ureters. Adrenoblocking agents modified the action of adrenomimetics. After blockade of alpha-receptors by phentolamine, isadrin decreased the contractions of all studied pieces of ureters, however, adrenaline decreased contractility of human ureters but increased--dog ureters. It may be proposed, that there are alpha 1 and alpha 2 receptors, that stimulated the contractility of human and dog ureters, beta 1 adrenoreceptors, that inhibited the contractions during blockade of alpha-receptors, and beta 2-receptors, that in these conditions increased the contractions of dog ureter but decreased the contractions of human ureters.


Clonal evolution in a myeloid cell line transformed to interleukin-3 independent growth by retroviral transduction and expression of p210bcr/abl. Current evidence suggests that the expression of the tyrosine kinase p210bcr/abl in chronic myelogenous leukemia (CML) may directly induce the initial phase of granulocytic hyperplasia. However, the dysregulation of additional genes appears to be required for transition to the acute leukemic phase, as inferred by the appearance of recurrent secondary cytogenetic abnormalities in the majority of patients. To determine whether the expression of p210bcr/abl alone is responsible for this genetic instability, we introduced and expressed the bcr/abl gene from a retroviral vector in a clone of the interleukin-3 (IL-3) dependent myeloblastic 32D C13(G) cell line. Clonal and polyclonal cells transformed to IL-3 independent growth were observed for a period extending up to 6 months for changes in the expression of p210bcr/abl, cell proliferation, inhibition by prostaglandin E1 (PGE1), forskolin, and cyclic adenosine monophosphate (cAMP) analogues, regulation of the cell cycle, and karyotype. Whereas the properties of control vector infected 32D C13(G)' cells remained stable over time, cells expressing p210bcr/abl were phenotypically unstable. In cells expressing p210bcr/abl, we observed selective modulation of p210bcr/abl mRNA and protein expression, evolution from partial to full abrogation of IL-3 dependence, reduced serum requirements, increased cell proliferation, decreased inhibition by PGE1 and cAMP analogues, and the appearance of new structural and numerical chromosomal abnormalities with successive cell passages. These results indicate that expression of p210bcr/abl can directly predispose 32D C13(G)' cells to genetic instability, promotes the emergence of clones with an increased proliferative advantage, and may represent an in vitro model suitable for the study of mechanisms underlying progression to the acute leukemic phase in CML.


Heterogeneous Epstein-Barr virus infection patterns in peripheral T-cell lymphoma of angioimmunoblastic lymphadenopathy type. In this study, 32 cases of T-cell lymphoma of angioimmunoblastic lymphadenopathy type (AILD-TCL) were investigated for their association with Epstein-Barr virus (EBV). For this purpose, three different approaches were applied: polymerase chain reaction (PCR) for the presence of EBV-DNA, in situ hybridization (ISH) for EBV-encoded small nuclear RNAs (EBER), and immunohistology for EBV-encoded latent membrane protein (LMP). PCR and EBER-ISH produced almost identical results, showing that all but one case of AILD-TCL contained EBV genomes. Three distinctive patterns of EBV infection were observed after immunophenotypical characterization of EBER-positive cells: (1) in 26% of the cases, B and T cells were infected, the majority of which were B cells of immunoblastic morphology located in the remnants of lymphoid follicles; (2) in 42% of the cases, the vast majority of infected cells were neoplastic T cells diffusely distributed in the lymph nodes, but infected B cells were also present; and (3) in 32% of the cases, there were only a few infected small lymphoid cells. Detectable LMP was frequent in cases exhibiting patterns 1 and 2. These findings suggest that in AILD-TCL patients, B cells and especially T cells are highly susceptible to a persistent EBV infection, which often leads to a growth advantage of the infected cells. Thus EBV, in conjunction with genetic abnormalities and selective defects of the immune system, might be involved in the pathogenesis of AILD-TCL.


Retinoic acid-resistant HL-60R cells harbor a point mutation in the retinoic acid receptor ligand-binding domain that confers dominant negative activity. Retinoic acid (RA) induces granulocytic differentiation of acute promyelocytic leukemia (APL) cells and is a useful therapeutic agent for patients with this disease. In the HL-60 promyelocytic leukemia cell line, this RA-induced granulocytic differentiation appears to be directly mediated through the RA receptor (RAR-alpha). We have previously identified a mutant subclone of HL-60 (designated HL-60R) that exhibits relative resistance to RA and that harbors RA receptors with markedly reduced affinity for RA. In the present study, we have now identified the genetic basis for this aberrant RA receptor activity. DNA sequencing of polymerase chain reaction-amplified cDNA products corresponding to the RAR-alpha ligand-binding domain shows a point mutation in RAR-alpha codon 411 in this mutant HL-60R subclone. This specific C-->T mutation generates a termination codon resulting in the truncation of 52 amino acids at the COOH terminal end of RAR-alpha. In cotransfection studies, expression vectors harboring this mutated RAR-alpha exhibit dominant negative activity with respect to the trans-activating function of the normal RAR-alpha. Although our observations are limited to HL-60 cells, similar RA receptor mutations might play an important role in the acquisition of RA resistance in RA-treated APL patients.


Increased thromboxane biosynthesis in patients with polycythemia vera: evidence for aspirin-suppressible platelet activation in vivo. Increased thromboxane (TX) production and modified aspirin sensitivity has been detected in vitro in platelets isolated from patients with polycythemia vera. To verify the relevance of these capacity-related measurements to the actual rate of TXA2 biosynthesis in vivo and its suppression by oral aspirin, we have investigated the urinary excretion of major enzymatic metabolites of TXB2 in 17 patients with polycythemia vera and 23 gender- and age-matched controls. Urinary 11-dehydro-TXB2 and 2,3-dinor-TXB2 were measured by previously validated radioimmunoassays. In addition, urinary immunoreactive leukotriene (LT) E4 was measured to explore the 5-lipoxygenase pathway of arachidonate metabolism. Polycythemic patients had significantly (P < .001) higher excretion rates of both 11-dehydro-TXB2 (1,033 +/- 1,050 v 117 +/- 45 pmol/mmol creatinine; mean +/- SD) and 2,3-dinor-TXB2 (725 +/- 676 v 82 +/- 43 pmol/mmol creatinine) than controls. In contrast, urinary LTE4 was not significantly different. Enhanced metabolite excretion did not correlate with the platelet count or with the hematocrit value, and was not related to the current treatment or to a clinical history of thrombotic complications. Platelet TX receptor studies did not show any significant changes in the binding characteristics of two different ligands. A platelet-selective regimen of aspirin therapy (50 mg/d for 7 to 14 days) was associated with greater than 80% suppression in metabolite excretion in nine patients. These results are consistent with abnormal stimuli operating in polycythemia vera to induce a selective enhancement in the platelet biosynthesis of TXA2 without changes in receptor binding. This in vivo abnormality in platelet biochemistry can be largely suppressed by low doses of aspirin.


Role of tumor necrosis factor-alpha and its specific 55-Kd and 75-Kd receptors in patients with lymphoproliferative disease of granular lymphocytes. The role of tumor necrosis factor-alpha (TNF-alpha) in the development of in vitro proliferative and cytotoxic abilities of granular lymphocytes (GL) in patients with lymphoproliferative disease of GL (LDGL) has been investigated. To this aim, taking advantage of the recent generation of specific monoclonal antibodies (MoAbs) reacting with the p55 and p75 TNF receptors (TNF-R) (htr-9 and utr-1 MoAb, respectively), we evaluated the expression and the functional role of each TNF-R in freshly isolated highly purified GL from a series of 10 LDGL patients (six CD3+ T-lineage GL and four CD3- natural killer [NK]-lineage GL). The expression of TNF-alpha transcripts and the release of TNF-alpha in the culture medium at resting conditions and following cell activation were also studied. Our data indicate that at resting conditions both CD3+ and CD3- GL express only the p75 TNF-R. Accordingly, a specific inhibition of phycoerythrin (PE)-conjugated TNF-alpha binding was demonstrated by the anti-p75 TNF-R utr-1 MoAb, but not by the anti-p55 htr-9 MoAb. Following activation with interleukin-2 (IL-2), anti-CD3, or anti-CD16 MoAbs, an increased expression of the p75 TNF-R and a slight induction of the p55 TNF-R was observed. Weak expression of specific TNF-alpha transcripts was detected at resting conditions and on unstimulated cells, whereas both IL-2 or anti-CD3 MoAb induced TNF-alpha mRNA. Under these in vitro conditions, detectable amounts of this cytokine were demonstrated in the culture supernatant of GL. The cytotoxic and proliferating activities mediated by IL-2 or anti-CD3 MoAb were dampened by anti-TNF-alpha antibody, suggesting a role for endogenous TNF-alpha in these functions. Both utr-1 and htr-9 MoAbs showed a moderate inhibition of proliferative activity, whereas cytotoxicity was not reduced. Taken together, our results suggest that TNF-alpha plays a role in the mechanisms leading to CD3+ and CD3- GL in vitro activation in patients with LDGL.


A switch toward demethylation is associated with the expression of myeloperoxidase in acute myeloblastic and promyelocytic leukemias. Expression of numerous genes encoding myeloid-specific proteins is tightly regulated during normal myeloid differentiation. This heterogeneous group of genes thus offers a tool for dissection of different maturational steps of myelopoiesis. We have previously shown that the human myeloperoxidase (MPO) gene is modified at numerous CpG residues in normal myeloid cells and in myeloid cell lines in a development-specific and expression-associated manner. In the present work, we have applied this type of methylation analysis to primary leukemia myeloid cell samples. We found that expression of MPO messenger RNA (mRNA) is grossly limited to leukemias of late myeloblastic and promyelocytic stages; expression is thus associated with progressive demethylation in the 5' region of the MPO gene. This modification was not global. Low-level induction of MPO mRNA expression in very immature leukemic cells using phorbol ester was not accompanied by progressive demethylation. This type of methylation analysis of a myeloid-specific gene may yield a molecular indicator for different types of myeloid leukemias.


Correlation of messenger RNA levels with protein defects in specific granule deficiency. Neutrophil specific granule deficiency (SGD) is a rare congenital disorder of unknown cause associated with an impaired inflammatory response and an absence of neutrophil secondary granules. Reduced levels of several neutrophil proteins have led to the suggestion that the defect may lie at the level of transcription, a hypothesis that is supported by abnormally low levels of lactoferrin message in the bone marrow of two SGD patients. We have examined the level of seven granule protein RNAs in one SGD patient and have compared them with reported protein levels. We have found the RNA levels for all of these genes to be reduced in proportion to the decreased levels of their respective proteins. These data further support the hypothesis that the reduced protein levels reflect a defect in transcriptional control.


A rapid method for starting a culture for the establishment of Epstein-Barr virus-transformed human lymphoblastoid cell lines. We developed a simple and efficient procedure for the establishment of Epstein-Barr virus-transformed human lymphoblastoid cell lines. B-lymphocytes were obtained by centrifugation after hemolysis of red cells with a hemolysis buffer, instead of Ficoll-Parque gradient. We can start a primary culture within 15 min by using this method.


Managing breast cancer in an outpatient setting. The treatment of advanced breast cancer has undergone relatively little change in the past decade. Reasons for such a static situation are the sobering realization that even effective chemotherapeutic regimens have had a minor impact on survival, and the paucity of new effective agents that have been introduced since initial combination treatments. Based in part on this lack of progress, in recent years dose-intensification in search of a curative strategy has been widely adopted. Its role remains to be defined, but ultimately it is likely to be relegated to situations where tumor burdens have been effectively reduced. This reduction in burden may not currently be feasible in many advanced presentations. Outpatient efforts will therefore focus on the following: 1) employing single agents optimally (e.g. infusion 5-fluorouracil), 2) using regimens which integrate new drugs with activity (e.g. taxol), and 3) testing measures which may improve the quality of life (e.g. bisphosphonates in the presence of bone metastases). Although one cannot approach the treatment of advanced breast cancer with the (misplaced) optimism of two decades ago, the expanded armamentarium currently available should lead to a more rational application of chemotherapy. Treatments will increasingly be based on the biology of the cancer, and on the therapeutic index and action of the drugs.


Viral infections in dentistry.

Viral infections in dentistry. Viral diseases of relevance to dentistry have recently been reviewed with respect to human immunodeficiency virus disease, other immunocompromised persons, oral malignancies, infection control, and antiviral therapy. This review discusses the most recent advances in the understanding of aspects of human immunodeficiency virus relevant to dentistry and relevant aspects of the herpesviruses, human papillomaviruses, hepatitis viruses, and other viruses. Further detail is available in other recent reviews.


New cell lines of human breast cancer origin. Established human mammary tumor cell lines constitute an important tool in the study of breast cancer. The aim of this work was to isolate and characterize two new mammary tumor cell lines, JCK and GCS, which were obtained from the pleural effusion and ascitic fluid, respectively, from two breast cancer patients. Both cell lines had some properties of transformed cells, namely immortalization and growth in soft agar. The carcinoma cells presented epithelial morphology shown by light and electron microscopy, and antigenic properties shown by different tumor markers such as a cytokeratin cocktail, carcinoembryonic antigen, epithelial membrane antigen, and human milk fat globule membrane antigen. A significant increase was also found (P greater than 0.05) in cell growth and 3H-thymidine incorporation into DNA in the JCK and GCS cell lines in the presence of 17 beta estradiol at concentrations of 10(-9) and 10(-7) M, respectively, after 5 days in culture. These cells presented estradiol receptor levels which were similar in the biopsies and the resulting cell lines. The aromatase activity was also similar in the JCK cell line and the original patient biopsy. However, there was a considerably higher aromatase activity in the GCS cell line than in the biopsy specimen. Southern hybridizations with the neu oncogene showed an additional 12 kb fragment in both cell lines, as also seen in patients with breast cancer. We conclude from these studies that this in vitro system may provide us with a way to study metastatic cells and improve clinical management of breast cancer patients.


Surgical treatment of Krukenberg tumours: case reports and clinical consideration. The authors present 4 cases of Krukenberg tumour of the ovary, secondary to carcinoma of the stomach (3 cases) and carcinoma of the breast (1 case). Pathologically it is characterized by the presence of typical signet ring cells and a diffuse infiltration of the stroma that gives the appearance of a sarcoma. Clinical data, computed tomography (CT) and sonographic findings in these four cases are analyzed. A review of the literature concerning this condition is provided and the treatment of the disease is discussed emphasizing the role of prophylactic oophorectomy.


Transcription of the gene for the gap junctional protein connexin43 and expression of functional cell-to-cell channels are regulated by cAMP. We investigated the mechanism by which cyclic AMP (cAMP) induces gap junctional communication via cell-to-cell channels in a communication-deficient rat Morris hepatoma cell line. We found that under basal conditions, the cells transcribe cx43 at a low level but do not transcribe cx26 or cx32. Elevation of intracellular cAMP, which induced communication, increased cx43 mRNA 15- to 40-fold and the rate of cx43 transcription 6-fold. Cx43 protein was detected by immunostaining in junctions of only those cells in which communication had been induced. We found the regulation by cAMP also in other cell lines; namely, in those with a low basal level of cx43 mRNA.


Epidermal growth factor disrupts gap-junctional communication and induces phosphorylation of connexin43 on serine. Growth factors regulate cellular proliferation and differentiation by activating plasma membrane tyrosine kinase receptors and triggering a cascade of events mediated by intracellular signaling proteins. The mechanism underlying growth factor modification of cellular functions, such as gap-junctional communication (gjc), has not been established clearly. Addition of epidermal growth factor (EGF) to T51B rat liver epithelial cells resulted in the rapid activation of EGF receptor tyrosine kinase activity followed by a transient dose-dependent disruption of gjc. This change did not result from the gross disturbance of membrane gap junction plaques as measured by immunofluorescence microscopy, but instead correlated with markedly elevated phosphorylation of the connexin43 (cx43) gap junction protein, a profound shift to predominantly phosphorylated forms of cx43, and the appearance of a novel phosphorylated cx43 protein. These changes in cx43 phosphorylation involved only serine residues. On restoration of gjc, these alterations in cx43 phosphorylation reverted to the pre-EGF treatment state. Both events were inhibited by the serine/threonine protein phosphatase inhibitor, okadaic acid. Therefore, unlike the case for pp60v-src, EGF-induced disruption of gjc is not associated with tyrosine phosphorylation of cx43, but instead may result from phosphorylation of cx43 by activated intracellular signaling serine protein kinase(s).


Naloxone is an inappropriate antagonist of met-enkephalin-modulated superoxide anion release. Met-enkephalin (MENK) increased superoxide anion release by human polymorphonuclear cells (PMNs) at a physiological (10(-10) M) concentration and decreased release at a relatively high (10(-8) M) concentration. Surprisingly, naloxone (NAL), used as a specific antagonist in these experiments, displayed immunomodulatory actions of its own, increasing superoxide anion release at 10(-10) and 10(-8) M concentrations. Although both were effective, the dose-response curves were different for NAL and MENK. NAL and MENK also had a combined influence on O2- release. The stimulative effect of 10(-10) M MENK could be abolished by 10(-8) M NAL in seven of eight cases. Unexpectedly, the stimulatory effect of 10(-8) and 10(-10) M NAL could be abrogated by MENK in five of eight cases as well. The fact that NAL and MENK mutually interfere with one another in their effect upon O2- release by human PMNs discredits NAL as an appropriate antagonist in this system.


Signal recognition particle receptor is important for cell growth and protein secretion in Saccharomyces cerevisiae. In mammalian cells, the signal recognition particle (SRP) receptor is required for the targeting of nascent secretory proteins to the endoplasmic reticulum (ER) membrane. We have identified the Saccharomyces cerevisiae homologue of the alpha-subunit of the SRP receptor (SR alpha) and characterized its function in vivo. S. cerevisiae SR alpha is a 69-kDa peripheral membrane protein that is 32% identical (54% chemically similar) to its mammalian homologue and, like mammalian SR alpha, is predicted to contain a GTP binding domain. Yeast cells that contain the SR alpha gene (SRP101) under control of the GAL1 promoter show impaired translocation of soluble and membrane proteins across the ER membrane after depletion of SR alpha. The degree of the translocation defect varies for different proteins. The defects are similar to those observed in SRP deficient cells. Disruption of the SRP101 gene results in an approximately sixfold reduction in the growth rate of the cells. Disruption of the gene encoding SRP RNA (SCR1) or both SCR1 and SRP101 resulted in an indistinguishable growth phenotype, indicating that SRP receptor and SRP function in the same pathway. Taken together, these results suggest that the components and the mechanism of the SRP-dependent protein targeting pathway are evolutionarily conserved yet not essential for cell growth. Surprisingly, cells that are grown for a prolonged time in the absence of SRP or SRP receptor no longer show pronounced protein translocation defects. This adaptation is a physiological process and is not due to the accumulation of a suppressor mutation. The degree of this adaptation is strain dependent.


[Transition of drug receptor mechanisms]. It is generally accepted that the agonists, full agonist and partial agonist, interact with the same receptors according to the classical receptor mechanisms. We tried to modify the drug receptor mechanisms in muscarinic cholinoceptors, alpha 1-adrenoceptors and beta-adrenoceptors. In the muscarinic cholinoceptor, there are two subtypes of M3-cholinoceptors, propylbenzilylcholine mustard (PrBCM)-sensitive receptors and PrBCM-resistant ones. The full agonists contract the longitudinal muscle through the interaction of two cholinoceptors, PrBCM-sensitive and-resistant ones, while the partial agonists produce the contraction through only the activation of PrBCM-sensitive ones. Upon activation PrBCM-sensitive receptors may use cytosolic Ca2+ more effectively than PrBCM-resistant receptors. In the alpha 1-adrenoceptor, the full agonist induces contraction through both alpha 1A and alpha 1B subtypes and the partial agonist through only alpha 1A subtype. The adrenoceptors activated by full agonist may be partly different from that by partial agonist in the arteries. In both the common iliac artery and thoracic aorta treated with the irreversible antagonist, phenoxybenzamine the slopes of schild plots of the results obtained from an antagonism between full agonist (phenylephrine) and alpha 1A-selective competitive antagonist (WB4101) equal to 1, suggesting that phenoxybenzamine preferably interacts with alpha 1B subtype. In the beta-adrenoceptor, the pD2-values of the partial agonists obtained from the concentration-response curves are significantly different from their pA2-values against full agonist (isoprenaline). The Scatchard plot of the specific [3H]befunolol (the partial agonist) binding showed two affinity sites of the receptors in the absence of Gpp(NH)p but the low affinity site was reduced while the high affinity site was not affected in the presence of Gpp(NH) p. The beta-adrenergic partial agonists are able to discriminate these two different binding sites of the beta-adrenoceptors. Our results suggest that the receptors activated by full agonists are partly different from those by partial agonists in muscarinic cholinoceptors, alpha 1- and beta-adrenoceptors, and that the irreversible antagonist can discriminate between the sites interact with full agonists and those with partial agonists in muscarinic cholinoceptors and alpha 1-adrenoceptors.


Effect of ageing on alpha 1A-adrenoceptor mechanisms in rabbit isolated bronchial preparations. Effect of aging on alpha 1A-adrenoceptor mechanisms in rabbit bronchial preparations was studied. The potency (pD2 value) of norepinephrine increased with age from 5 to 13 weeks and thereafter did not alter with age from 13 to 180 weeks. The affinity of norepinephrine (pKA value) and of a selective alpha 1A-adrenoceptor blocker, 5-methylurapidil (pA2 value) did not alter with age. Efficacy of norepinephrine was proportional to receptor reserve (pD2-pKA). These results suggest that age-related changes in alpha 1A-adrenoceptor mechanisms are due to changes in receptor reserve or total concentration of receptors, but not to changes in affinity of drugs to alpha 1A-adrenoceptors and in contraction mechanisms.


Inflammatory and toxic myopathies.

Inflammatory and toxic myopathies. The major advances in the immunopathogenesis and treatment of inflammatory myopathies, and the main criteria that distinguish polymyositis (PM) from dermatomyositis (DM) or inclusion-body myositis (IBM) are presented. The origin and implications of the amyloid and ubiquitin deposits found within the vacuolated fibers of patients with IBM are considered. The pathogenesis of human immunodeficiency virus (HIV) and human T-cell lymphotrophic virus (HTLV)-I-associated PM is presented, and the role of retroviruses in triggering PM, even in the absence of detectable viral genome within the muscle fibers, is discussed. In addition, three toxic myopathies with distinct morphologic, biochemical, or molecular characteristics, caused by zidovudine [azidothymidine (AZT) myopathy], the cholesterol-lowering-agent myopathy (CLAM), and the combination of blocking agents with corticosteroids are presented.


Motor neuron diseases and viruses: poliovirus, retroviruses, and lymphomas. The viral theory of motor neuron disease (MND) has been rejuvenated in the last 5 years for several reasons. First, it is now recognized that enteroviruses and picornaviruses similar to poliovirus can persist and induce immune-mediated diseases. In some picornavirus animal models, the immune-mediated disease can occur and continue long after the infectious virus has been cleared, and in some cases of human MND an immune-mediated disease may occur. Second, the human retroviruses human immunodeficiency virus (HIV) and human T-cell lymphotrophic virus (HTLV) have caused isolated MND syndromes. Neither of these two specific viruses appear to be 'the amyotrophic lateral sclerosis (ALS) retrovirus', because they cause a plethora of neurologic syndromes unrelated to MND. Retroviruses of mice, however, can cause MND and lymphomas, and because there is an increased incidence of lymphomas in ALS patients, it has been suggested that retroviruses are another possible viral agent of human MND.


Nerve conduction and electromyography.

Nerve conduction and electromyography. The advent of computer-based methodology in routine electromyography has much improved the analysis of motor unit (MU) decomposition, of interference pattern study, and of MU counting. Measuring minimum motor and sensory conduction velocities is becoming more accessible and is considered an essential procedure in assessing the condition of peripheral nerves. A series of studies has shown that nerve resistance and vulnerability can be modified by a steep temperature gradient, by ciguatera toxin, or by hyperventilation-induced changes in the electrical properties of the axonal membrane. The controversy as to the diagnostic procedures to use in cases of radiculopathy and carpal tunnel syndrome (CTS) shows no sign of abating. There is, however, general consensus that electrophysiologic procedures must play a key diagnostic role in these conditions. Lastly, several interesting articles have been published describing the use of electrophysiologic tests in motor neurone diseases. Moreover, some advances have been made in the diagnostic yield of single-fibre electromyography (SFEMG) with axonal microstimulation in myasthenia gravis and Eaton-Lambert myasthenic syndrome.


Central conduction studies and magnetic stimulation. Magnetic stimulation of brain and spinal roots provides non-invasive evaluation of the propagation of nerve impulses as well as characteristics of excitability along the motor pathways. Physiology of motor performances and pathophysiology of movement disorders can be approached with this new technique. Moreover, transcranial stimulation (TCS) of non-motor areas of the brain represents a formidable probe for the evaluation of lateralized hemispheric properties connected with higher cortical functions.


Hepatocellular carcinoma producing carcinoembryonic antigen and carbohydrate antigen 19-9. A case of hepatocellular carcinoma producing carcinoembryonic antigen and carbohydrate antigen 19-9 is reported. The serum level of carcinoembryonic antigen was 26,800 ng/ml and carbohydrate antigen 19-9, 5,500 U/ml on the final day. Immunohistochemical study revealed positive monoclonal antibodies for these two antigens within the cytoplasm of the hepatocellular carcinoma cells.


Adrenal myelolipoma associated with congenital adrenal 21-hydroxylase deficiency. The occurrence of adrenal myelolipomas is reported in an untreated patient with congenital adrenal 21-hydroxylase deficiency. Laparotomy demonstrated the presence of two lesions, a large tumor which arose from an ectopic adrenal cortex and a smaller tumor in the left adrenal gland. Six cases of adrenal myelolipomas and congenital adrenal hyperplasia have been reported in the literature. All patients were associated with excessive ACTH secretion for a long period of time. The relative frequency of this association, coupled with the observation by Selye and Stone (Am J Pathol 26:211, 1950) that anterior pituitary extracts cause myelolipomatous changes in rats, may indicate a possible role for ACTH in the development of myelolipomas.


Giant hypertrophic gastritis and acute hepatitis associated with cytomegalovirus infection. A 38-year-old man developed prominent hypoproteinemia after acute elevation of serum transaminase levels. Giant hypertrophy of the gastric mucosa, a short serum albumin half-life, and the absence of massive hepatocyte necrosis established the diagnosis of protein-losing gastropathy. The hypoproteinemia, gastric fold hypertrophy and hepatitis remitted spontaneously within 4 months. A high antibody titer against cytomegalovirus suggested an association between the viral infection and the patient's disease.


Mucinous carcinomas involving the prostate: atypical findings at MR imaging. The magnetic resonance (MR) imaging findings in four patients with mucinous tumors involving the prostate are presented. The MR appearance of these tumors differed from that of typical prostatic adenocarcinomas in that the signal intensity on T2-weighted images approximated or exceeded that of the uninvolved peripheral zone. The unusual appearance of mucinous prostate tumors may present problems in diagnosis and staging with MR imaging.


Can liver transplantation be applied for the treatment of liver cancer? Unfavourable results and shortage of donor organs have led to restricted indication of liver transplantation for irresectable hepatocellular carcinoma. This review analyses the current state of experience in order to work out criteria for a more differentiated multimodal treatment including liver transplantation. New techniques of extended liver resection under hypothermic perfusion have to be considered in some conventionally irresectable tumors. Split-liver transplantation is a donor organ saving option which preserves the chance of transplantation in individual tumor patients without disadvantage for patients with benign diseases.


Low molecular weight heparins. An objective overview. The introduction of low molecular weight heparins has added a new dimension to the management of thrombotic disorders. Ten LMWHs are currently available for clinical use. Although these agents have been primarily developed and used in European countries, other countries, including the US, have started to evaluate their usefulness. Well designed clinical trials have been carried out for different clinical indications with several of these products. In contrast to other prophylactic antithrombotic drugs (heparin, warfarin, aspirin), LMWHs have provided consistently impressive clinical results. Moreover, the other products have less desirable tolerability profiles than that of LMWHs. As shown in both experimental and clinical settings, the prophylactic antithrombotic efficacy of each LMWH is distinct in itself being characteristic to only that particular drug. Besides the currently available LMWH preparations, some 14 other agents are under development at this time. Although both the original and newer products have similar basic characteristics, the physicochemical properties and the pharmacological actions of each of these agents may differ significantly. All manufacturers should follow the Food and Drug Administration (FDA) guidelines and conduct their own clinical trials on each of their products. Many significant developments of LMWHs will take place in the coming years; in addition to development for prophylactic use, LMWHs will be developed for therapeutic intervention.


A case of intraductal papillary adenocarcinoma of the pancreas associated with mass forming chronic pancreatitis. A case of intraductal papillary adenocarcinoma of the pancreas associated with mass forming chronic pancreatitis without calcifications is described. Pancreatolithiasis, or calcified pancreas, is recognized as a high risk factor for pancreatic cancer. However, epidemiologic studies have found that carcinoma of the pancreas associated with chronic pancreatitis was rare. The question is whether chronic pancreatitis without calcifications is actually a precancerous background lesion or not. This case suggests that hyperplasia of the pancreatic ductal epithelium may be a precancerous lesion for pancreatic cancer in some patients with chronic pancreatitis.


Expression of the cell surface antigen detected by the monoclonal antibody A7 in pancreatic carcinoma cell lines. In a previous study, we used a murine monoclonal antibody, A7, against human colon carcinoma as a drug-carrier to treat colorectal cancer. In the present study, we found that MAb A7 also reacted immunohistochemically with 73% of human pancreatic carcinoma cell lines, with the A7 antigen mainly being detected on the cell surface. However, the A7 antigen was found in only 9% of the spent media of these human pancreatic carcinoma cell lines by ELISA. On the other hand, the positive incidence of CA19-9, POA, ferritin, CEA, DU-PAN-2 and SLX in those spent media was 100%, 64%, 64%, 55%, 55% and 36%, respectively. These results suggest that the A7 antigen may only rarely be shed into the sera of pancreatic cancer patients, in which case MAb A7 could be a suitable drug-carrier in targeting chemotherapy for pancreatic cancer patients.


A case report of intraoperative ultrasonic exploration for an inferior vena cava thrombectomy of the right Wilms' tumor. The intraoperative ultrasonic explorations for a case of right Wilms' tumor with inferior vena cava thrombosis are reported. This method of assessment is most appropriate for cases of inferior vena cava thrombectomy of malignant tumors either with or without an inferior vena cava resection.


Impairment of the activity of the hepatic microsomal glucose-6-phosphatase system in three preterm infants. Three preterm infants born at 26-30 weeks' gestation who died between 103 and 266 days after birth were found to have elevated hepatic glycogen levels. Kinetic analysis of the hepatic microsomal glucose-6-phosphatase system demonstrated that one infant had abnormally low levels of activity of the glucose-6-phosphatase enzyme (partial type 1a glycogen storage disease) and two had deficiencies of T2, a microsomal phosphate/pyrophosphate transport protein (type 1c glycogen storage disease). In all three cases glycogen storage disease was not suspected prior to death even though both hypo- and hyperglycaemic episodes were recorded in the first 15 days after birth indicating that they had somewhat disordered blood glucose regulation. In the infant with low glucose-6-phosphatase enzyme activity, abnormal development of the glucose-6-phosphatase enzyme cannot be ruled out. This is the first description of abnormalities in the glucose-6-phosphatase system in preterm infants.


Increased protein absorption after acute gastroenteritis in children. We investigated the intestinal absorption of the macromolecule human alpha-lactalbumin during and after an episode of acute gastroenteritis in children. Twenty children were studied in the acute phase and 17 excreted rotavirus. Eleven children were studied again 5-8 weeks later (convalescent phase). Human alpha-lactalbumin serum concentrations in the acute phase were similar but in the convalescent phase they were significantly (p less than 0.001) higher than those in the reference children. The serum concentrations were also higher in the convalescent than in the acute phase (p = 0.021). This study suggests that there is an increased absorption of proteins from the gut into the circulation 5-8 weeks after rotavirus gastroenteritis.


Human cytomegalovirus (HCMV)-specific immunoglobulin E as a serologic marker for HCMV infection in immunocompromised patients. An antibody capture assay using an enzyme-linked human cytomegalovirus (HCMV) antigen for the detection of specific immunoglobulin E (IgE) was established. IgG, M, and E responses to HCMV were studied in 497 sera obtained from 44 renal transplant recipients and 51 acquired immunodeficiency syndrome (AIDS) patients. The results were compared with those obtained from 58 HCMV-seropositive healthy individuals. HCMV-specific IgE was detected in 11 (91.7%) renal transplant recipients with primary HCMV infection. In contrast, antibodies of the IgG and IgM classes were detected in only 6 (50.0%) of these patients. Specific IgE was detected in 10 (90.9%) out of 11 renal allograft recipients suffering from secondary HCMV infection. Significant IgG titer rises and IgM were detected in 2 (18.2%) and 6 (54.6%) of these patients, respectively. IgG titer rises and IgM and IgE antibodies were seen in 5 (12.2%), 1 (2.4%) and 18 (43.9%) AIDS patients respectively. All healthy immunocompetent HCMV-seropositive individuals were tested IgE negative. The results obtained in our study indicate that IgE against HCMV is a more reliable serologic marker for primary and secondary HCMV infection than IgM in immunocompromised individuals, especially in organ transplant recipients, since it is not affected by the prophylactic application of HCMV hyperimmune globulin preparations.


Comparison of shell viral culture and serology for the diagnosis of human cytomegalovirus infection in neonates and immunocompromised subjects. The present retrospective study compares the laboratory diagnosis of cytomegalic inclusion disease (CID) by the use of "shell vial culture" [i.e., immunoperoxidase staining of human cytomegalovirus (HCMV) early antigen in human fibroblasts 24 h postinoculation] to the results of serology (i.e. immunoglobulins IgG, IgM, and IgA HCMV antibody testing) in 21 infants with congenital or postnatally acquired HCMV infection, 5 patients with lymphoproliferative disorders, 35 human immunodeficiency virus (HIV)-seropositive patients who met the Centers for Disease Control (CDC) criteria for stages IVA and IVB of HIV infection, and 115 patients suffering from the acquired immunodeficiency syndrome, AIDS (stages IVC-IVE according to CDC criteria). HCMV infection was diagnosed by means of the shell vial culture inoculated with patient samples (e.g., urine, bronchoalveolar lavage, induced sputum, etc.) and serology in 163 (92.6%) and 65 (36.9%) patients, respectively. Viral shedding was detected by shell vial culture in 100% of the neonates, 80% of the patients suffering from lymphoproliferative disorders, 100% of the AIDS related complex (ARC) and 89.6% of the AIDS patients. In contrast, serologic testing for HCMV-specific antibodies was positive in only 28.6%, 42.9%, and 34.8% of the neonates, ARC, and AIDS patients, respectively. In lymphoma patients, serologic testing gave identical results (80%) to the shell vial culture technique. With the use of the shell vial procedure, active HCMV infection in immunocompromised subjects and neonates can be recognized more reliably than by serologic testing. Nevertheless, in a low percentage of patients (7.4%), virus isolation by the shell vial culture may fail to detect HCMV infection.


Neuromyotonia: report of a case.

Neuromyotonia: report of a case. Neuromyotonia is a rare condition of peripheral nerve dysfunction characterized by the signs of motor nerve hyperactivity, namely, myokymia, fasciculations, and muscular stiffness. Relaxation of voluntary muscle contraction is delayed, and fluid movements are impaired to a variable degree. Signs of sensory involvement are less frequent. Usually, therapy with carbamazepine or phenytoin provides rapid improvement. In the present communication, a typical case is reported, and the most important differential diagnoses are outlined.


Urinary free cortisol versus 17-hydroxycorticosteroids: a comparative study of their diagnostic value in Cushing's syndrome. We evaluated the usefulness of the basal urinary 24-h excretion rates of free cortisol versus 17-hydroxycorticosteroids in the diagnosis of Cushing's syndrome. On an outpatient basis, both urinary free cortisol and 17-hydroxycorticosteroids levels were determined in 48 patients with Cushing's syndrome, as well as in 95 obese and 94 healthy control persons of normal weight. Determination of the urinary free cortisol content allowed a clear-cut distinction between the patients with hypercortisolism and the controls, resulting in a sensitivity of 100% and specificity of 98% for the diagnosis of Cushing's syndrome. The diagnostic accuracy of urinary free cortisol was distinctly superior to that of 17-hydroxycorticosteroids, which showed a wide overlap of values between the groups, with a sensitivity of 73% and a specificity of 94%. In conclusion, the measurement of basal urinary free cortisol provided an excellent diagnostic sensitivity and specificity in the assessment of adrenocortical function. This simple and accurate test thus seems to be particularly useful in the outpatient evaluation of patients with suspected Cushing's syndrome.


Immunoglobulin preparations from hepatitis C antibody-positive plasma donors: influence on diagnosis and risk of infection in heart transplant recipients. All heart transplant patients in our clinic received intravenous immunoglobulins as a prophylaxis against cytomegalovirus infections or reactivations. Serum was sampled from 160 heart transplant patients within 4 months after surgery. In 98 samples (61%) hepatitis C virus (HCV)-specific antibodies could be detected by a "second generation" enzyme immunoassay. Of these HCV antibody-positive patients 89 were tested for a second time. At this time, 5-11 months later, in 66 patients (74%) the HCV antibody had disappeared. In the 23 still positively reacting patients, immunoglobulins were given in the last 6 months before serum sampling. Nine commercial immunoglobulin preparations were tested for HCV-specific antibodies and the presence of HCV RNA. Seven preparations were anti-HCV positive with titres in the range of 64-256, whereas reverse transcription and polymerase chain reaction did not detect HCV RNA in any immunoglobulin preparation. Passive antibody transfer rather than a HCV infection is the cause of HCV antibody detection in our patients. The presence of HCV antibodies in high concentrations in commercial immunoglobulin preparations may only be explained by an extremely high proportion of anti-HCV-positive single donations in the plasma pools used for immunoglobulin production. The passive HCV antibody transmission prevents anti-HCV serological monitoring of patients treated with these preparations. Additionally, there are reports on the transmission of hepatitis non-A, non-B via immunoglobulin preparations. Therefore, we recommend an anti-HCV screening of plasma donors.


[Mechanisms and therapeutic effect of Cordyceps sinensis (CS) on aminoglycoside induced acute renal failure (ARF) in rats]. Nephrotoxic ARF model of rat was induced by IP injection of either Gentamycin or Kanamycin and treated with CS. The results of study showed that the simultaneous administration of CS with Gentamycin could protect the proximal tubular cells from Gentamycin toxicity and the use of CS after the establishment of Kanamycin nephrotoxic ARF could prompt an earlier recovery from ARF as compared with the control group. The possible mechanisms of CS on ARF include: (1) protecting tubular cell sodium pump activity; (2) attenuating tubular cell lysosome overfunction stimulated by phagocytosis of aminoglycoside; (3) decreasing tubular cell lipoperoxidation in response to toxic injury.


The effectiveness of the air-powder abrasive device for root planing during periodontal surgery. The efficacy of the air-powder abrasive device (APAD) in root planing during flap surgery was assessed in vitro and in vivo. Two teeth on which full-thickness flaps were raised underwent root planing by hand-scaling alone and hand-scaling combined with APAD. One tooth extracted prior to surgery underwent unrestricted hand-scaling under a binocular microscope (control). The two teeth root planed in situ and the tooth root planed in vitro were observed by scanning electron microscopy (SEM). Then, 10 patients with periodontitis requiring flap surgery were selected for a clinical study. After raising full-thickness flaps, 29 sites from five patients underwent root planing using hand-scaling combined with APAD, whereas 22 sites from six patients underwent root planing by hand scalers only. SEM revealed that root surfaces planed in situ by hand-scaling combined with APAD were smoother than those root-planed using hand scalers alone. The control tooth surface was as smooth as those submitted to combined root planing. The clinical study showed that sites submitted to combined root planing displayed enhanced attachment level gain and pocket reduction. These results, associated with the shortened instrumentation time, suggest APAD as a useful instrument for root planing during flap surgery.


Inhalation of amorphous silica: morphological and morphometric evaluation of lung associated lymph nodes in rats. Male Wistar rats inhaled amorphous silica (quartz glass VP 203-006) for 12 months. Animals were sacrificed after 4, 8, and 12 months of inhalation and after a post-inhalation period of additional 12 months. Morphological as well as morphometric changes of lung associated lymph nodes are studied in comparison with findings due to crystalline quartz (DQ-12) and with a control group without dust exposure. Qualitatively, the lymph node morphology of the dust exposed groups is the same. During the first months mainly small quartz-typical reaction areas occur. From 12 months severe fibroses are detectable. Relative organ weights and the total lymph node area (LNA) are increased in all dust exposed groups. After inhalation of the amorphous quarz glass, the changes seem to appear with a certain delay. But, at the end of the experiment, the morphometric parameters (quartz-typical areas (QTA) and QTA/LNA-ratio) are more enlarged after the amorphous quartz glass than after crystalline quartz DQ-12. The results show that amorphous as well as crystalline silica can lead to severe lymph node fibrosis. This indicates that occupational exposure limits for amorphous silica are generally justified.


Translation inhibition by phosphorothioate oligodeoxynucleotides in cell-free systems. A detailed comparison was made of the concentration dependence of translation inhibition by phosphorothioate and phosphodiester oligodeoxynucleotides of the same anti-beta-globin sequence in cell-free systems using beta-globin mRNA and unrelated mRNAs as controls. The results confirm that at low concentrations the phosphorothioate oligomer is more potent as an antisense compound, while at higher concentration (greater than 4 microM) it exhibits more nonspecific inhibition than the phosphodiester oligomer for RNase H-mediated translation inhibition.


Antisense oligonucleotide inhibition of bovine leukemia virus tax expression in a cell-free system. Tax, the trans-activating protein of bovine leukemia virus, stimulates the long terminal repeat to promote viral transcription and also activates cellular genes that may be involved in tumorigenesis. To study Tax regulation, we identified antisense oligodeoxynucleotides that inhibit tax translation in rabbit reticulocyte lysate. Two antisense oligonucleotides directed toward the 5' end of tax RNA inhibited translation by 59% and 45%, when compared to the effect of a random sequence oligonucleotide. This inhibitory effect was independent of RNase H. In contrast, antisense directed at the middle of the tax RNA inhibited by only 12%, but, in the presence of RNase H, inhibited 38%. An antisense oligonucleotide directed at the 3' portion of tax RNA was not inhibitory and, in fact, stimulated translation. Identification of these inhibitory antisense sequences may allow elucidation of the biological role of Tax in BLV-persistent lymphocytosis and tumorigenesis.


Spectral change in heart rate variability in response to mental arithmetic before and after the beta-adrenoceptor blocker, carteolol. Spectral analysis of heart rate fluctuation was evaluated before and after administration of carteolol, a non-selective beta-adrenoceptor-blocker, to investigate the neural regulatory mechanisms underlying the haemodynamic changes induced by mental stress. Mental stress increased blood pressure and heart rate, with an increased low frequency band, and low frequency/high frequency ratio of the power spectral analysis which are indices of sympathetic activity. Carteolol did not change basal and pre-mental stress measurements of blood pressure, heart rate and spectral density. However, carteolol altered the response to mental stress with a decrease in spectral density of the low frequency band and low frequency/high frequency ratio, and an increase in the high frequency component. These results confirm that mental stress elevates blood pressure by activating the sympathetic nervous system, and suggest that blockade of the beta-adrenoceptor attenuates the pressor response by preventing the autonomic responses to mental stress.


Effect of alcoholism treatment on cirrhosis mortality: a 20-year multivariate time series analysis. Substantial empirical evidence suggests that alcohol consumption is an important cause of cirrhosis mortality levels. However, recent research has failed to find the expected positive relationship between consumption and cirrhosis mortality, in both the United States and Canada, when data from the mid-1970s through the late 1980s are analysed. Although recent studies have investigated a number of possible explanations, this study examines the hypothesis that an increase in the provision of treatment for alcoholism resulted in a disjuncture in the established relationship between consumption and cirrhosis deaths. This hypothesis is evaluated with a multivariate time series model in which the relationship between consumption and cirrhosis mortality is estimated with controls for treatment and the unemployment rate, using data from the US state of North Carolina. The results indicate that with treatment controlled, changes in cirrhosis mortality are independent of consumption. Further, treatment has a significant short-term lagged effect on cirrhosis mortality, suggesting that the impact of treatment on chronic alcohol abusers may be one of delaying the consequences of such abuse.


Elderly vs. younger problem drinker 'treatment' and recovery experiences. To address the question of whether or not elderly problem drinkers experience any treatment contact discrimination or recovery rate disadvantages, the programme utilization and recovery rate experiences of a representative sample of older and younger persons arrested for drinking and driving (OWI) in Iowa were compared. Subjects were interviewed by phone or mail shortly after their OWI arrest and then again approximately 12 months later. Younger persons (18-54 years old) were compared with elderly persons (55 and over and 65 and over). The elderly subjects were also dichotomized as early onset (at least one problem drinking indicator occurred prior to age 55) or late onset (all problem drinking indicators occurred at age 55 or later). The elderly were as likely as, or more likely than, their younger counterparts to make a treatment contact, to remain in treatment and to recover.


A comparison of women seeking drug and alcohol treatment in a specialist women's and two traditional mixed-sex treatment services. The paucity of research on the treatment needs of women with substance abuse problems has been a serious impediment to the development of empirically validated treatment programmes. Women continue to be seriously under-represented as research subjects and clients of treatment services. This study compares the characteristics of 80 women attending a specialist women's treatment service with those of eighty women attending two traditional mixed-sex treatment agencies. Women attending a gender-sensitive service were significantly more likely to have dependent children, to be lesbian, to have a maternal history for drug or alcohol problems and to have suffered sexual abuse in childhood. These results suggest that gender-sensitive treatment services may be recruiting women who might not otherwise have sought treatment for their substance dependence problems.


Binding receptors for alpha-L-fucosidase in human B-lymphoid cell lines. An established mechanism for directing newly made acid hydrolases to lysosomes involves acquisition of mannose 6-phosphate residues by the carbohydrate portion of acid hydrolases followed by binding to specific membrane-bound transport receptors and delivery to lysosomes. Two distinct phosphomannosyl receptors (CI-MPR and CD-MPR) have been identified. Alternative mechanisms for trafficking acid hydrolases exist. This report examines means for the possible receptor-mediated intracellular transport of alpha-L- fucosidase in lymphoid cells. The binding of alpha-L-fucosidase to intact cells and to total cell membrane preparations, in conjunction with immunoassays of solubilized membrane preparations, revealed the presence of CI-MPR and CD-MPR on human lymphoid and fibroblast cell lines. The mean level of CD-MPR in nine lymphoid cell lines was 7.2-fold greater than CI-MPR. The mean level of CI-MPR in two fibroblast lines was 3.8-fold greater than CD-MPR. The mean content of CI-MPR was 19.5-fold greater in the fibroblasts than in the lymphoid cells. The CD-MPR content of fibroblasts and lymphoid cells was nearly equivalent. Among these cell lines were a fibroblast and a lymphoid line from the same individual. These results indicate that human B-lymphoid cells are deficient in CI-MPR and suggest that modulation of expression of CI-MPR and CD-MPR in lymphoid cells differs from that in fibroblasts, including cell lines with identical genomes. No specific receptor capable of binding alpha-L-fucosidase independent of mannose 6-phosphate was demonstrable, despite published results that support the existence of a mannose 6-phosphate independent trafficking mechanism in lymphoid cells for this enzyme.


Diagnostic histopathology, cytogenetics, and molecular markers of pediatric brain tumors. The purpose of this article is to summarize some of the current issues in diagnostic histopathology and to provide an update of both molecular and cytogenetic studies of the most commonly encountered pediatric brain tumors. Most of the discussion focuses on astrocytomas, primitive neuroectodermal tumors and medulloblastomas, and ependymomas because they make up the majority of these neoplasms. A few comments on choroid plexus tumors are also included.


Alternative splicing induced by insertion of retrotransposons into the maize waxy gene. The molecular basis for the low level expression of three alleles of the maize waxy (Wx) gene has been described. Each allele contains a retrotransposon in intron sequences. These insertions represent previously undescribed elements, and their association with three wx alleles indicates that retrotransposon elements are important agents of spontaneous mutation in maize. For each allele, element sequences are spliced from pre-mRNA with the surrounding intron even though the insertions increase intron length by approximately 40- to 60-fold. In addition, despite differences in element sequences, insertion sites, and relative orientations, each element disrupts long-range splice site recognition leading to novel Wx transcripts where exons both upstream and downstream of the insertion site are skipped. The expression of wx alleles with large insertions in introns provides support for studies that indicate that the primary cis requirement for maize introns is the splice donor and acceptor sites.


A mutant lectin gene is rescued from an insertion element that blocks its expression. The soybean lectin gene Le1 encodes a prevalent seed protein and is highly regulated during the life cycle. The mutant lectin gene allele le1 is not transcribed detectably, contains a 3.5-kb Tgm1 insertion element within its coding region 0.6 kb 3' to the transcription start site, and leads to a lectinless phenotype. To determine whether the Tgm1 element or a secondary mutation was responsible for repressing le1 gene transcription, we eliminated the insertion element by constructing a chimeric lectin gene (le1/Le1) that contained the 5' half of the le1 gene and its promoter region and the 3' half of the wild-type Le1 gene. Transformed tobacco seed containing the le1/Le1 gene produced both lectin mRNA and protein, demonstrating that the mutant lectin gene control region is transcriptionally competent. By contrast, transformed seed containing the le1 gene produced no detectable lectin mRNA. We conclude that the absence of detectable transcription from the le1 gene is due to transcriptional inhibition by the Tgm1 insertion element and that this element acts at a distance to block transcription from an upstream promoter region.


Expression and purification of kringle 4-type 2 of human apolipoprotein (a) in Escherichia coli. The most frequently occurring kringle 4 domain of human apolipoprotein (a), Kringle 4-subtype 2 (K4(2)), was expressed as a fusion protein with the maltose binding protein in Escherichia coli using the "tac" promoter. Although the fusion protein was expressed without a signal sequence, 25% was secreted into the periplasmic space; the remainder was found associated with the soluble cytosolic fraction. The fusion protein was readily isolated from whole cell lysate by amylose agarose affinity chromatography. Although a factor Xa cleavage site was engineered into the fusion protein, it was found that release of the K4(2) protein was most conveniently achieved by proteolysis with subtilisin A. The cleavage product produced in this way was shown to be intact K4(2) with only the first three amino acid residues of the leading flanking peptide missing, as judged by N-terminal sequence analysis. K4(2) was isolated from the hydrolysate by FPLC on a Mono-Q column with a yield of 170 +/- 30 micrograms/g wet cells. The resulting protein was monomeric in phosphate-buffered saline as judged by size-exclusion chromatography and appeared to be folded as shown by spectroscopic and immunological assays. The recombinant K4(2) did not bind to either lysine- or proline-Sepharose, suggesting that the ligand binding activities of lipoprotein (a) may reside in the other kringle domains of apolipoprotein (a).


[Latent cervical virus infection as a possible cause of early abortion]. Cervical smears of 50 women who had an abortion were examined by dot-blot hybridization for human papillomavirus (HPV), herpes simplex virus (HSV) types 1 and 2, and cytomegalovirus (CMV) DNA. HPV DNA type 16 or 18 positivity was shown in 17.6% of the cases; in the aborted material, however, it amounted to 30.8%. IgM-positive titres were present in a few cases. In cervical smears of intact pregnancies, positivity for HPV DNA types 6 and 11 was detected in 9.5% and for the HSV DNA types 1 and 2 and CMV DNA in 48.0% of the cases. In this group of patients mostly positive IgM and IgG titers were present.