Modulation, in vivo and in vitro, of surface expression of CD18 by bovine neutrophils. A series of experiments was designed to elucidate some of the factors that may influence surface expression of CD18 by bovine neutrophils. Expression of CD18 was determined by immunofluorescence flow cytometry. Neutrophils recovered from the uterus of cows (n = 9) after intrauterine administration of sterile oyster glycogen solution expressed (mean +/- SD) 123 +/- 21% more CD18 than did circulating neutrophils recovered simultaneously from the same cows (P = 0.003). In 8 cows given 20 mg of dexamethasone IM daily for 3 days, expression of CD18 on blood neutrophils was 29.6 +/- 8% less after treatment than before treatment (P = 0.0078). Neutrophils from 12 cows or bulls exposed to phorbol myristate acetate in vitro increased expression of CD18 by 137 +/- 37% (P = 0.0035). Likewise, exposure of neutrophils from 8 cattle to zymosan-activated bovine plasma increased CD18 exposure by 10.6 +/- 3.8% (P = 0.029). These findings indicate that expression of CD18 by bovine neutrophils is a dynamic system, capable of responding to inflammatory stimuli. Inadvertent activation of neutrophils may be responsible for some of the variance in expression observed when examining large groups of cattle for CD18 expression by neutrophils. The ability of bovine neutrophils to respond rapidly to various stimuli by increasing surface expression of CD18 indicates that a pool of intracellular CD18 may be available for inclusion in the plasmalemma, as has been reported for human neutrophils.


In vitro studies of the antirhinovirus activity of soluble intercellular adhesion molecule-1. We studied the in vitro antirhinovirus activity of a soluble form of intercellular adhesion molecule-1 (sICAM-1). sICAM-1 inhibited the cytopathic effect of 10 representative human rhinovirus (HRV) serotypes of the major receptor group with, 50% effective concentrations (EC50s) of 0.1 to 7.9 micrograms/ml. Cell type-dependent variation in the inhibitory activity of sICAM-1 was observed for two major receptor group serotypes in HeLa cells (EC50, greater than 32 micrograms/ml), and no inhibitory effect was observed for two serotypes which use different cell receptors. Yield reduction assays showed that sICAM-1 inhibited the replication of HRV serotype 39 (HRV-39) in human adenoid explants in a concentration-dependent manner. No direct inactivation of infectivity of HRV-39 (EC50, 0.5 microgram/ml) was observed after incubation with sICAM-1 (32 micrograms/ml) for up to 24 h. Single-cycle-of-replication experiments with the addition of sICAM-1 at 10 micrograms/ml at different times showed that the inhibitory effect occurs only when sICAM-1 is added within 30 min after infection. In experiments in which absorption was carried out at 4 degrees C and then a single cycle of replication incubation was carried out at 33 degrees C, it was found that sICAM-1 at 10 micrograms/ml was inhibitory only when it was present during the absorption period. Our data show that sICAM-1 is inhibitory for representative major receptor group serotypes of HRV in two cell lines and human respiratory epithelium, that the interaction of sICAM-1 with HRV is readily reversible by dilution, and that the inhibitory effect of sICAM-1 on virus replication is present early in the infection cycle.


Development of resistance to zidovudine in HIV strains isolated from CD4+ lymphocytes and plasma during therapy. An assay based on production of HIV antigen in cultures of CD4+ lymphocytes infected 'in vitro' with cell-free virus was established. Using this assay it was possible to isolate, propagate and reliably determine the zidovudine susceptibility of HIV isolates from all patients despite differences in cellular tropism and syncytium inducing capacity. Using this assay, differences in zidovudine susceptibility of 52 serial isolates obtained from 16 patients before and after initiation of therapy were examined. HIV with a 10- to 100-fold reduced susceptibility to zidovudine were isolated from 13 patients as early as 4 months after initiation of therapy. Number of months of zidovudine treatment was strongly associated with development of viral resistance, and high CD4 cell counts tended to be associated with lower rates of development of resistance. That patients can harbor mixtures of virus strains with different susceptibility to zidovudine was confirmed by the differences in susceptibility between isolates obtained simultaneously from CD4+ lymphocyte and plasma, and by the differences in susceptibility between virus strains isolated from clones of CD4+ lymphocytes.


Regulation of urea uptake in Pseudomonas aeruginosa. The energy-dependent urea permease was studied in two strains of Pseudomonas aeruginosa, measuring the uptake (transport and metabolism) of 14C-urea. In both strains urea uptake in vivo and urease activity in vitro differed significantly with respect to kinetic parameters, temperature and pH dependence and response to metabolic inhibitors. Ammonium strongly interfered both with the expression of the urea uptake system and its activity. The inhibition of the uptake activity by ammonium was partially relieved by hydraziniumsulfate, which prevented the translocation of ammonium into the cell, and in a methylammonium/ammonium transport-defective mutant of strain DSM 50071. Furthermore, methionine-sulfoximine, which prevented the intracellular glutamine formation from ammonium via inhibition of glutamine synthetase, relieved the inhibition of urea uptake by ammonium. These findings suggested that urea uptake activity in P. aeruginosa is regulated by intracellular glutamine.


Genomic studies on killer yeasts belonging to the genus Pichia. Twenty-four species belonging to the genus Pichia were investigated using restriction fragment length polymorphism (RFLP) and Southern blot hybridization of their genomic DNA. Saccharomyces cerevisiae, Kluyveromyces lactis, Williopsis mrakii and Candida albicans were also included in this study. The RFLP patterns were obtained from digestion of yeast DNA with several restriction endonuclease enzymes, and showed various bands with different mobility; in most isolates, the more deeply stained bands were species-specific. This observation was confirmed by the results obtained from Southern blot hybridization of the EcoRI and XhoI RFLP patterns with P. anomala UCSC 25F DNA, digested with the same enzymes, used as probes. These bands are likely to be ribosomal DNA as shown by hybridization of digested DNA from unrelated yeast species (S. cerevisiae, K. lactis and C. albicans). However, one hybridized band, located at 3.9-4.1 Kb, seems to be peculiar to the Pichia species. Our study confirms the usefulness of molecular tools in studying genetic relatedness among yeasts.


Insulin-mediated inhibition of the induction of tyrosine aminotransferase by dexamethasone. Insulin-mediated regulation of glucocorticoid-induced expression of the liver-specific gene tyrosine aminotransferase was studied in a clone of the Reuber rat hepatoma cells. Insulin inhibited dexamethasone-induced chloramphenicol acetyltransferase expression from approximately 4 kb of TAT 5' flanking sequence. The degree of this inhibition was comparable to the response of the endogenous gene. A construct of approximately 3 kbp of 5' flanking sequence exhibited no significant basal expression but retained sensitivity to glucocorticoids and to insulin inhibition of the glucocorticoid response. Results of further analysis of the insulin response in deletion constructs and constructs containing glucocorticoid responsive elements ligated to a heterologous promoter suggest that in addition to the glucocorticoid response elements a region close to the start site in the TAT promoter is necessary for insulin to inhibit glucocorticoid-mediated induction of expression.


(6R)-5,6,7,8-tetrahydro-L-biopterin modulates nitric oxide-associated soluble guanylate cyclase activity in the rat cerebellum. (6R)-5,6,7,8-Tetrahydro-L-biopterin (R-THBP) is a cofactor not only for aromatic amino acid hydroxylases in mammalian tissues but also for nitric oxide synthase (NOS) induced by endotoxins or cytokines in some kinds of cells. Recently it has been reported that nitric oxide (NO) has biological activity in endothelium and in brain as well. NO activates soluble guanylate cyclase (sGC). Superoxide reacts with NO easily and shortens the half-life of NO actions. We found, in a study using rat cerebellar cytosol fraction, that R-THBP itself did not directly activate sGC, but activated sGC at concentrations ranging from 0.1 to 10 microM only under NO generating conditions of activated NOS and in the presence of sodium nitroprusside. In addition, R-THBP (1 microM) did not alter the NOS activity, which was determined by L-citrulline formation. These results suggest that R-THBP may regulate sGC activity associated with NO formation in the central nervous system.


[Genetic alterations in the genesis and development of ovarian cancer]. Genetic alterations of various cancers have been clarified by recent development of molecular biology. Multiple genetic alterations occur through the development of cancer. Both activation of proto-oncogenes and inactivation of tumor suppressor genes are important for the development of cancer. Alterations of oncogenes such as K-ras, c-erbB-2/HER-2/neu and c-myc, and those of tumor suppressor genes such as p53, RB and DCC have been reported in ovarian cancer. Allelic losses of the specific chromosomes, which suggest the existence of tumor suppressor genes on those chromosomes, also have been reported in ovarian cancer. Further studies on genetic alterations of ovarian cancer will clarify the mechanisms for the development of ovarian cancer and also will develop new methods for prevention, diagnosis and treatment in clinical.


[Treatment of recurrent ovarian cancer]. Significant prolongation of survival time among the patients with advanced ovarian cancer has been brought under the development of surgery and chemotherapy, but even those with clinical remission shows sometimes recurrence. For the recurrent ovarian cancer patients at present there are no definite strategy to treat the recurrent cases. Under these circumstance, we have reviewed the current treatment of cytoreductive surgery and chemotherapy for the recurrent cases. 1) surgical treatment Generally, in the cases of recurrent ovarian cancer, cytoreductive surgery is required to minimize the residual tumour in the abdomen. But sometimes we can find the distant metastasis including liver, lung, and lymph node. This means that surgery is not sufficient for control of recurrent tumor. Further adjuvant chemotherapy will be required to control metastatic tumors. 2) chemotherapy After the detail assessment of the initial treatment of cases, at first we should think about retreatment with CDDP-based regimen and secondly about dose-intensification of CDDP or CBDCA for the CDDP-resistant cases. And as combination regimens, topoisomerase inhibitors, etoposide or CPT-11 are also preferable to use, alkylating agents such as ifosfamide, 5-fluorouracil, and some current trials with new drug, taxol are effective for recurrent cases. In conclusion, further active chemotherapy using platinum compounds, topoisomerase inhibitors, taxol will be achieved for the control of the recurrent cases of ovarian cancer.


Accidental ingestion of 'Ecstasy' (3,4-methylenedioxymethylamphetamine). There is no report of the effects of 'Ecstasy' (3,4-methylenedioxymethylamphetamine) poisoning in childhood. The case of a 13 month old boy who ingested one capsule of Ecstasy is reported. Neurological and cardiovascular side effects predominated, which responded well to treatment with a chlormethiazole infusion.


Incidence of hereditary porphyria cutanea tarda (PCT) in a sample of the Italian population. The determination of the enzymatic activity of URO-D in erythrocytes is the screening method used for differentiation between hereditary and non-hereditary forms of porphyria cutanea tarda (PCT). The aim of the present work was to establish the relative frequencies of the symptomatic and hereditary forms by the determination of the URO-D enzyme in the PCT patients who were regularly treated at the Centre for Porphyrins in our Institute. In the course of this work we also examined the statistical properties of the distributions of both normal and porphyric subjects, so as to be able to suggest values for discriminating between normal subjects and the various types of porphyric subjects.


[Laser lithotripsy in the treatment of ureteral lithiasis]. Laser lithotripsy constitutes a safe method with a success rate of 95% in the treatment of ureteral calculi. The photoacoustic properties of the laser permit stone fragmentation without injury to tissue. The major disadvantage of this technique is its cost. The availability of increasingly smaller electrohydraulic systems that are less costly questions the routine use of the laser system. Another aspect that must be considered is the rapid development of endourologic techniques and instruments in recent years. The use of laser-induced shock waves is not exclusive to the field of Urology. In other surgical specialties where electrohydraulic energy is difficult to use, it constitutes a necessary technique. Such is the case of endoscopy of the bile ducts, fragmentation of pancreatic calculi and lithiasis of the salivary glands. Another possible field of application of laser-induced shock waves is coronary angioplasty.


Circulating cytokine levels in patients with rheumatoid arthritis: results of a double blind trial with sulphasalazine. Interleukin 1 (IL-1), IL-6, and tumour necrosis factor (TNF) alpha are pleiotropic cytokines produced predominantly by macrophages which have been implicated in the pathogenesis of rheumatoid arthritis (RA). Sulphasalazine has been shown to have disease modifying properties and to inhibit the production of cytokines in vitro. To evaluate the effect of sulphasalazine on cytokine production in vivo, serum cytokine levels were measured in a group of patients with RA entered into a randomised controlled trial. Serum levels of IL-1 alpha, IL-1 beta, IL-6, and TNF alpha were measured at baseline and at two monthly intervals for six months in 17 patients receiving sulphasalazine and in 22 patients treated with placebo. The two groups of patients had a similar age and sex distribution, had had RA for less than a year, had no joint erosions, and had not been treated previously with any other disease modifying drugs. In the 39 patients studied IL-1 alpha was detected (> 0.1 ng/ml) at baseline in 14 patients (median 0.24 ng/ml), IL-1 beta in 25 patients (median 1.0 ng/ml), TNF alpha in 27 patients (median 1.2 ng/ml), and IL-6 in 33 patients (median 0.44 ng/ml). In the group treated with sulphasalazine there was a progressive and significant decline in serum IL-1 alpha, IL-1 beta, and TNF alpha levels over the six month period (median levels at six months were < 0.1, 0.12, and 0.44 ng/ml respectively). Interleukin 6 levels were significantly reduced only at the four month time point (median level of 0.23 ng/ml). These reductions were associated with improvements in clinical and laboratory measures of disease activity. In contrast patients receiving the placebo showed no changes in serum cytokine levels and no improvement in clinical and laboratory indices of disease activity. These results suggest that sulphasalazine may exert its disease modifying effect partly by suppressing cytokine production in vivo.


Evaluation of sulphasalazine in the treatment of spondyloarthropathies. Sulphasalazine has been shown to have an effect in patients with spondyloarthropathies, but the clinical indication for its use is controversial and its long term effect has not yet been evaluated. Treatment with sulphasalazine was analysed retrospectively in a group of 372 patients with a wide range of spondyloarthropathies to determine subsets of patients showing differential effects of the drug. One hundred and one patients received sulphasalazine at a mean daily dose of 2 g (ankylosing spondylitis, 54 patients; psoriatic arthritis, 21 patients; reactive arthritis, four patients; arthritis related to inflammatory bowel disease, six patients; undifferentiated spondyloarthropathy, 16 patients). A comparison between treated and untreated patients suggests that only patients with active and severe disease were treated whatever the precise diagnosis or the amount of axial disease in the spondyloarthropathy. After six months of treatment improvement was noted in 59 patients unrelated to their subgroup or amount of axial disease. After a mean follow up of 20 months, 37 patients were still receiving treatment, 33 had discontinued the drug because of inefficacy, 14 because of side effects, six because of remission of the disease, and 11 for other reasons. Comparison between the beginning and end of treatment showed a statistically significant decrease in morning stiffness, erythrocyte sedimentation rate, and daily dose of non-steroidal anti-inflammatory drugs (NSAIDs). It is concluded that: (a) a low percentage of patients with spondyloarthropathy have active disease requiring treatment with sulphasalazine despite the use of NSAIDs (27% in this study); (b) in this subgroup of patients sulphasalazine seems to be of clinically relevant benefit in 59%; and (c) this benefit does not seem to be correlated with either the precise diagnosis of spondyloarthropathy or the amount of axial disease.


Retrovirus infections in the south of Cameroon. The results of a national HIV seroprevalence survey carried out in 1986/87 showed a 1% HIV seroprevalence in the South of Cameroon, which is higher than in the other regions of the country. We here demonstrate the presence of HTLV-I infections in the South of Cameroon with possible clustering of infection in some villages. Some evidence suggestive of the presence of HTLV-II was obtained. Sera from patients with onchocerciasis did not react on HTLV testing. No HTLV associated haematological or neurological syndromes were observed during this survey. Regarding the human immunodeficiency viruses, the HIV-1 prevalence varied from 0 to 3% in the different populations studied. None of the subjects was HIV-2 positive.


Revival of the radial artery for coronary artery bypass grafting. Eighteen years after its first introduction for coronary artery revascularization, the radial artery (RA) was reinvestigated because of unexpected good long-term results in the early series. Since July 1989, 104 patients underwent myocardial revascularization using 122 RA grafts (18 patients received two grafts). The left internal mammary artery (IMA) was concomitantly used as a pedicled graft in 100 cases and the right IMA in 19 cases; a free IMA graft was used in 29 cases and a saphenous vein graft in 24 cases. A mean of 2.8 grafts per patient were performed. Nine patients underwent associated procedures: carotid endarterectomy (3), aortic valve replacement (3), Bigelow procedure (1), and mitral valve repair (2). The target artery receiving the RA was the circumflex (n = 59), diagonal (n = 29), right coronary (n = 27), and left anterior descending (n = 7). One patient died (0.96%) and 2 had perioperative myocardial infarct. Sternal wound infection was noted in 3 cases of double IMA implantation. No ischemia of the hand was observed. All patients received diltiazem started intraoperatively and continued after discharge. In addition aspirin (100 mg/day) was given at discharge. Early angiographic controls (less than 2 weeks) were obtained in the first 50 consecutive patients and revealed 56 of 56 patent RA grafts, 48 of 48 patent left IMA grafts, 11 of 11 patent right IMA grafts, 14 of 18 patent free IMA grafts, and 8 of 9 patent vein grafts.(ABSTRACT TRUNCATED AT 250 WORDS)


Systolic hypertension in the elderly. Pathophysiology and management. Isolated systolic hypertension occurs with increased prevalence in the elderly population. It is characterized by reduced vascular compliance, often combined with increased peripheral resistance. These changes are not specific to patients with systolic hypertension, occurring, perhaps to a lesser extent, in the normotensive aging population as well. Systolic hypertension is associated with a risk of cardiovascular morbidity and mortality that possibly exceeds that associated with systolic-diastolic hypertension. However, until the recent report of the Systolic Hypertension in the Elderly Program, the benefit of treatment of this population was undocumented. The Systolic Hypertension in the Elderly Program demonstrated that lowering of blood pressure with a diuretic, combined, when necessary, with a beta blocker, reduced the rate of myocardial infarction and stroke. Other agents may also be effective in lowering blood pressure, although their ability to reduce cardiovascular morbidity and mortality in this population remains to be documented. The results suggest that pharmacologic treatment be considered for patients older than 60 years whose systolic blood pressure remains above 160 mm Hg (with a diastolic pressure below 90 mm Hg). Whether treatment should be recommended for all patients with systolic hypertension, or, alternatively, for only those at higher risk for cardiovascular events, remains controversial.


Survival in a cohort of human immunodeficiency virus-infected tuberculosis patients in New York City. Implications for the expansion of the AIDS case definition. The occurrence of pulmonary tuberculosis in human immunodeficiency virus (HIV)-infected persons is believed to represent a less severe stage of HIV-related disease with a more favorable prognosis than other acquired immunodeficiency syndrome (AIDS)-defining conditions; therefore, it has been excluded from the AIDS definition established by the Centers for Disease Control (Atlanta, Ga) criteria. To determine the prognosis of patients with HIV-related tuberculosis, we assessed the clinical, immunologic, and HIV infection status of a cohort of male subjects aged 20 to 44 years who were hospitalized with tuberculosis but without AIDS in New York City hospitals from 1985 through 1986, and we determined their mortality through May 1991. The 58 patients who agreed to participate were largely (90%) nonwhite and had a high prevalence of pulmonary tuberculosis (90%) and HIV infection (53%). Patients who were HIV seropositive had significantly lower CD4 cell counts (median, 0.136 x 10(9)/L; range, 0.013 x 10(9) to 2.314 x 10(9)/L vs median, 0.765 x 10(9)/L; range, 0.284 x 10(9) to 2.333 x 10(9)/L), and, during the follow-up period, an 83% mortality rate that was 7.5 times higher than the 11% rate in seronegative subjects. Survival analyses revealed that for all HIV-seropositive subjects the probability of death at 30 months was 72% and the median survival was 21 months (95% confidence interval, 15.5 to 26.5 months), while for HIV-seropositive subjects with CD4 cell counts of 0.2 x 10(9)/L or less, the probability of death at 30 months was 92% and the median survival was 15.75 months (95% confidence interval, 14.0 to 17.6 months). The prognosis for patients with HIV-related pulmonary tuberculosis is poor, and those with CD4 cell counts of 0.2 x 10(9)/L or less have survival patterns similar to that of patients with AIDS. We believe that these data support the expansion of the AIDS case definition to include persons with both pulmonary tuberculosis and severe HIV-related immunosuppression.


Familial hyperinsulinism presenting in adults. Two adult siblings presented with recurrent syncope due to severe hyperinsulinemic hypoglycemia. Exploratory laparotomy in the elder sibling showed a grossly normal pancreas, but histologic examination revealed islet cell hyperplasia. Neither sibling has any evidence of the multiple endocrine neoplasia type 1 syndrome, nor is there any other family history to suggest this diagnosis. To our knowledge, this is the first report of adult-onset familial hyperinsulinism without other manifestations of multiple endocrine neoplasia type 1 syndrome. A simple provocative test for hyperinsulinism was also suggested by these cases. Because the initial patient related his symptoms to exercise, we used treadmill exercise in both patients to diagnose hyperinsulinism and observe its response to therapy.


[Non invasive evaluation of cardiovascular effects of nebivolol in patients with cardiac insufficiency]. The results of several studies, mostly without controls, have suggested that betablockers, administered at progressively increasing doses, may be beneficial in cardiac failure. Based on this hypothesis, betablockers with a peripheral vasodilator effect, such as Nebivolol, could be particularly valuable in this indication. A preliminary study of its tolerance, haemodynamic and neurohormonal effects was carried out with a noninvasive methodology in 12 patients with cardiac failure in sinus rhythm, 8 men and 4 women (average age 53 +/- 12 years), all of whom had Class III or IV symptoms according to the NYHA Classification. The protocol had 2 phases: the first was an open phase during which Nebivolol was administered at a dose of 1 mg/day for 48 hours then 2.5 mg/day for 72 h. In the second phase, the patients were randomly separated into 2 groups, one to receive placebo and the other 2.5 mg for one week then 5 mg of Nebivolol for the 5 remaining weeks. The heart rate decreased significantly from 70 +/- 3 to 63 +/- 4 beats/min (p < 0.01) with Nebivolol 1 mg/day without further slowing at the 2.5 mg dosage. During the randomised phase, the heart rate remained stable in the Nebivolol group but increased to its initial value in the group given placebo. No aggravation of symptoms was observed in the Nebivolol group. No significant changes in cardiac output, parameters of cardiac loading or contractility could be demonstrated after 6 weeks' treatment. During submaximal exercise testing, plasma concentrations of catecholamines and atrial natriuretic factor tended to be higher with Nebivolol than with placebo.(ABSTRACT TRUNCATED AT 250 WORDS)


Overexpression of the c-erbB-2 oncogene in sarcomas and small round-cell tumors of childhood. An immunohistochemical investigation. Amplification and overexpression of the c-erbB-2 oncogene have been associated with a poor prognosis in breast cancer. The present study evaluates c-erbB-2 protein over-production in sarcomas and in small round-cell tumors of childhood by applying an immunohistochemical technique to formalin-fixed, paraffin-embedded tissues. This technique had previously demonstrated high sensitivity for the detection of c-erbB-2 activation. One peripheral neuroepithelioma demonstrated equivocal immunoreactivity for c-erbB-2 protein. There was no evidence of c-erbB-2 protein overproduction in 11 angiosarcomas, 21 chondrosarcomas, 10 epithelioid sarcomas, 14 Ewing's sarcomas, 20 hepatoblastomas, nine leiomyosarcomas, 12 liposarcomas, 13 malignant fibrous histiocytomas, nine malignant lymphomas, 15 neuroblastomas/ganglioneuroblastomas, 16 neurofibrosarcomas, 10 osteosarcomas, seven peripheral neuroepitheliomas, 10 rhabdomyosarcomas, six synovial sarcomas, and 20 Wilm's tumors. We conclude that overproduction of the c-erbB-2 protein is rare or absent in these neoplasms and that its detection is therefore not likely to be of practical utility in their pathologic evaluation and prognostication.


The effect of lipophilic substituents on the H2-histaminergic activity of some close analogues of impromidine. The cimetidine-like moiety of the potent H2-agonist impromidine (9a) and three closely related guanidines (10a, 11a, and 12a) which are modified in the imidazolylpropyl portion, has been replaced by 2-[(2-pyridyl)methylthio]ethyl, 2-(benzylthio)ethyl and 3,3-diphenylpropyl substituents. Guanidines 10-12 were obtained from acidic hydrolysis of corresponding N-benzoyl guanidines 7, 8, and 15, accessible by successive aminolysis of diphenyl N-benzoyl carbonimidate (2) according to known methods. Compared with leads 10a and 11a lipophilic substitution affords almost equipotent H2-agonists 10b-d and 11b-d, while substituents with increasing lipophilicity enhance both intrinsic activity and potency of the weak partial agonist 12a at guinea-pig atrial H2-receptors. Guanidines 10-12 are weak H1-antagonists on the isolated guinea-pig ileum.


Effects of major and minor surgery on plasma glutamine and cytokine levels. The plasma levels of glutamine and cytokines have been measured frequently in patients before, during, and after elective abdominal aortic aneurysm surgery ("major surgery") or inguinal hernia repair ("minor surgery"). The plasma glutamine level declined rapidly following major surgery and remained markedly below preoperative levels until at least 7 days after surgery. This response of the plasma glutamine levels was significantly correlated with the production of interleukin 6 but not with that of interleukin 1, tumor necrosis factor, or interferon gamma. In contrast, following minor surgery, the plasma glutamine level was unchanged and the elaboration of interleukin 6 was attenuated. The decrease in the plasma glutamine level following major surgery may contribute to the state of immunosuppression, which follows major surgery, and the relationship between amino acid and cytokine metabolism is worthy of further study.


Identification of muscarinic acetylcholine receptors in isolated canine lingual epithelia via voltage clamp measurements. Acetylcholine (ACh), muscarine and methacholine all decreased the short-circuit current (Isc) measured across isolated canine lingual epithelia bathed in symmetrical solutions of Krebs-Henseleit buffer when added to the serosal, but not mucosal, solutions. Atropine inhibited the ACh-induced decrease in Isc whereas serosal solutions of 1 mM hexamethonium or 1 mM nicotine did not. Addition of a membrane-permeable analogue of cAMP also reduced Isc and, in the presence of this analogue, the decrease in Isc produced by ACh was markedly reduced. These data suggested the presence of muscarinic acetylcholine receptors in the serosal membranes of isolated canine lingual epithelia. The decrease in Isc induced by ACh may involve the inhibition of Ba(2+)-inhibitable K+ currents, as the addition of 100 microM BaCl2 to the serosal solution inhibited Isc and also completely inhibited the response produced by ACh. These findings suggest that responses of sensory fibres in lingual epithelia elicited by ACh may involve an interaction of ACh with epithelial cells rather than a direct interaction of ACh with receptors on sensory nerves.


Oro-facial trauma in children.

Oro-facial trauma in children. Dentoalveolar trauma is unfortunately a regular part of medical practice. The prompt management of such injuries is vital in re-establishing a healthy dentition. As well, the promotion of preventive equipment is paramount: from seat belts and bike helmets to mouthguards. The purchase of over the counter one-size-fits-all mouthguards is not only a waste of money but dangerous. Well made mouthguards fitted by a dentist are a sensible investment to reduce the frequency and severity of costly dental injury and to preserve the attractive aesthetics of natural teeth (Figures 21 and 22). They must be worn in competition and at practice.


Distribution of tyrosine hydroxylase-like immunofluorescence in guinea pig vestibular ganglia and sensory areas. The distribution of tyrosine hydroxylase (TH)-like immunofluorescence was analyzed in the guinea pig vestibular ganglia and end organs using a monoclonal antibody to TH. TH was chosen as a marker for the sympathetic fibers because TH regulates the first step of catecholamine synthesis by converting tyrosine to dopa. In the vestibular ganglia, there were TH-positive nerve fibers having distinct varicosities surrounding the vestibular ganglion cells. In the sensory areas, there was a sympathetic plexus in the subepithelial tissue of the saccule, the utricle, and the crista ampullaris. We speculated that the sympathetic innervation has a direct influence on the vestibular ganglion cells and diffuse influence on the capillary permeability.


The biology of personality.

The biology of personality. Historically, models of personality have generally postulated, or assumed, a link with biology. This century has witnessed a major revision of these ideas with both behavioural and psychoanalytic theorists emphasising life experiences as being largely responsible for behaviour as adults. Challenges to this assumption of the overwhelming importance of life experiences are reviewed. An extensive body of data now exists suggesting that biology contributes significantly to individual variability. This biological contribution occurs at a relatively low level in the central nervous system, best defined as temperament. Further research has suffered from the lack of a cohesive psychobiological model. Cloninger's tridimensional theory of personality is presented as a model which attempts to bridge the gap between theoretical temperamental traits, neurotransmitter function and clinical psychiatry. It is to be hoped that new theoretical models will be formulated which will focus on the importance of temperamental variables in psychiatric disorders.


Symptomatic response to antipsychotics differs between recent onset and recurrent chronic schizophrenic patients. The symptomatic response to standard antipsychotic treatment was assessed over the first 4 weeks of hospitalisation in 39 patients with DSM-III schizophrenia, active phase, using the Brief Psychiatric Rating Scale (BPRS). While highly significant improvement was noted overall, 36% of patients either did not improve or worsened. Furthermore there was no diminution in the withdrawal-retardation factor of the BPRS. Patients experiencing their first admission to hospital, all with recent-onset illness, were then compared with patients who presented with a recurrence and had illness of at least 3 years duration. Despite similarities in overall response, withdrawal-retardation scores did not diminish in recent-onset patients, in contrast to multiple admissions who demonstrated significant improvement. These findings suggest greater responsiveness of negative symptoms to treatment in patients with longstanding illness, and possibly a poorer prognosis in first admission patients with deficit manifestations.


Neurotransmitter receptors involved in post-training memory processing by the amygdala, medial septum, and hippocampus of the rat. Rats were trained and tested in habituation to a novel environment and step-down inhibitory avoidance. Immediately after training in each task the animals received intra-amygdala, intraseptal, or intrahippocampal micro-injections of agonists and antagonists of various neurotransmitter receptors. In the habitation task, intrahippocampal, but not intra-amygdala or intraseptal administration of the NMDA receptor antagonist aminophosphornopentanoic acid (AP5, 5.0 micrograms) or of the muscarinic receptor antagonist, scopolamine (2.0 micrograms) caused amnesia and the indirect antagonist of GABA-A receptors, picrotoxin (0.08 microgram), caused retrograde facilitation. Intrahippocampal administration of the respective agonists, glutamate, oxotremorine, and muscimol, had effects of their own opposite to those of the blockers, and norepinephrine (0.3 microgram) caused memory facilitation. In the avoidance task, results obtained with drug infusions given into the three structures were very similar: in all cases, AP5, scopolamine, and muscimol were amnestic, and glutamate, oxotremorine, norepinephrine, and picrotoxin caused memory facilitation. In addition, also in the three structures, picrotoxin counteracted the amnestic effect of AP5 and/or scopolamine and the beta-adrenoceptor blocker, timolol (0.3 microgram), while ineffective on its own, attenuated all the effects of picrotoxin. The results suggest that similar synaptic mechanisms in the amygdala, medial septum, and hippocampus are involved in memory consolidation: NMDA, muscarinic, and beta-noradrenergic receptors stimulate and GABA-A receptors inhibit this process, and beta-noradrenergic receptors modulate the GABAergic synapses. In the avoidance task these mechanisms operate in the three structures: in habituation only those in the hippocampus are operative. Possibly in each structure these mechanisms regulate, if not actually consolidate, a different aspect, component, or form of memory.


Strain-dependent effects of post-training dopamine receptor agonists and antagonists on memory storage in mice. Post-training administration of the selective D1 or D2 agonists SKF 38393 and LY 171555 dose dependently impairs retention of an inhibitory avoidance response in DBA/2 mice. In agreement, the selective D1 or D2 antagonists SCH 23390 and (-)-sulpiride improve retention. These effects are opposite to those observed in the C57BL/6 strain, as previously reported. Moreover, B6D2F1 hybrids present a response to SKF 38393, LY 171555, SCH 23390, and (-)-sulpiride that parallels that of the C57BL/6 strain, thus suggesting that the neural mechanisms underlying the effects of DA agonists or antagonists on memory processes may be inherited through a dominant mode of inheritance.


Filamentous forms of Bordetella avium: culture conditions and pathogenicity. Difficulties in preparing suitable antigen for the microagglutination (MA) test led to the discovery of a filamentous form of Bordetella avium. Broth media high in nutrients, vigorous shaking, and incubation at 37 C appeared to promote the development of filamentous forms of the organism. Peptone broth did not induce the development of filamentous forms. Eleven different isolates having both smooth and rough colony types were tested and observed to form filaments of various lengths. Filamentous forms of B. avium hemagglutinated guinea pig erythrocytes were motile, had pili and flagella, and were stable up to the fourth or fifth passage in broth media, at which time a predominance of typical coccobacillus organisms were observed. Filamentous forms of B. avium originating from smooth-colony types were pathogenic in turkey poults, whereas the filamentous forms of B. avium originating from rough-colony types were not pathogenic.


The homeotic gene spineless-aristapedia affects geotaxis in Drosophila melanogaster. The homeotic mutation spineless-aristapedia (ss(a)) transforms the aristae into second tarsi. Flies with a ss(a) phenotype also show extremely positive geotaxis as measured in a Hirsch-type geotaxis maze. Other antennal mutants and flies with their aristae amputated do not show such extreme positive geotaxis. Deletion analysis has comapped the geotaxis effect with ss(a) in band 89C on the third chromosome. Finally, a biometrical analysis has detected additional genes on the X chromosome that also affects geotaxis.


Medication use and the assessment of agoraphobic avoidance. Many anxiety disorder patients who present for behaviour therapy are already taking anxiolytic medications. The present study added a new subscale to the Mobility Inventory labelled 'Without Medication' to assess possible reliance on medication for coping with phobic situations. 121 Patients with panic-related disorders were administered the scale. The results supported the reliability and validity of the existing Mobility Inventory subscales in general and of the new subscale in particular. It appears to reliably assess a clinically important domain that is not measured in traditional self-report measures of phobic avoidance.


Fearful distortions.

Fearful distortions. Clinical observations suggesting that perceptual distortions can take place during episodes of fear are described, and two hypotheses are set out: (1) perceptual distortions occur during episodes of fear, and (2) such distortions decline after reduction of the pertinent fear. An experiment in which fearful subjects were asked to report their perceptions of a feared object during episodes of fear, and then again after fear-reduction, was carried out. Snake-phobic and spider-phobic subjects showed evidence of some distortions in the activity of the pertinent fear object, but no distortions of size. After the reduction of the relevant fear, the subjects reported significant declines in the activity of the pertinent animal. The two hypotheses received partial support.


Ethanol increases receptor-dependent cyclic AMP production in cultured hepatocytes by decreasing G(i)-mediated inhibition. Increasing evidence suggests that ethanol-induced changes in cyclic AMP (cAMP) signal transduction play a critical role in the acute and chronic effects of ethanol. Here we have investigated the effects of ethanol on cAMP signal transduction in primary cultures of rat hepatocytes. Acute exposure to ethanol had a biphasic effect on glucagon-receptor-dependent cAMP production in intact cells: 25-50 mM-ethanol decreased cAMP, whereas treatment with 100-200 mM-ethanol increased cAMP. After chronic exposure to 50-200 mM-ethanol for 48 h in culture, glucagon-receptor-dependent cAMP levels were increased, but no change in glucagon receptor number was observed. These effects of ethanol were independent of ethanol oxidation. Chronic ethanol treatment also increased adenosine-receptor- and forskolin-stimulated cAMP production. Increased cAMP production was also observed upon stimulation of adenylate cyclase with glucagon, forskolin and F- in membranes isolated from cells cultured with 100 mM-ethanol for 48 h. However, no differences were observed in basal and MnCl2-stimulated adenylate cyclase activity. The quantity of alpha i protein was decreased by 35% after chronic ethanol treatment, but no change in the quantity of alpha s protein was detected. Decreased alpha i protein was associated with a decrease in G(i) function, as assessed by the ability of 0.1 nM-guanosine 5'-[beta gamma-imido]triphosphate and 1 microM-somatostatin to inhibit forskolin-stimulated adenylate cyclase activity. Taken together, these results suggest that chronic exposure to ethanol increases receptor-dependent cAMP production in hepatocytes by decreasing the quantity of alpha i protein at the plasma membrane and thereby decreasing the inhibitory effects of G(i) on adenylate cyclase activity.


Modulation in vivo of beta-adrenergic-receptor subtypes in rat brown adipose tissue by the thermogenic agonist Ro 16-8714. The number of beta 3-adrenergic receptors (AR) in plasma membranes from interscapular brown adipose tissue (IBAT) was decreased by 62% in lean Zucker rats treated with the thermogenic beta-adrenergic agonist Ro 16-8714 as compared with controls after 72 h of treatment. The loss of beta 3-AR number was preceded by a 93% decrease in the steady-state level of beta 3-AR mRNA at 30 h. Similar results were obtained in obese (fa/fa) Zucker rats. Ro 16-8714 had no effect on the number of beta 1- and beta 2-ARs in IBAT. This is the first report to demonstrate that the beta 3-AR in IBAT can be specifically down-regulated in vivo by exposure to a thermogenic agonist.


Molecular modelling of D2-like dopamine receptors. Three-dimensional computer models of the rat D2, D3 and D4 dopamine receptor subtypes have been constructed based on the diffraction co-ordinates for bacteriorhodopsin, another membrane-bound protein containing seven transmembrane domains presumed to be arranged in a similar spatial orientation. Models were assembled by aligning the putative transmembrane domains of the dopamine receptors with those of bacteriorhodopsin using sequence similarities, and then superimposing these modelled alpha-helices on to the bacteriorhodopsin-derived co-ordinates. These models explore the potential hydrogen bonding, electrostatic and stacking interactions within the receptor which may be important for maintaining the conformation of these receptors, and thereby provide target sites for agonist binding. Proposed interactions between the catecholamine ligands and these receptors appear to account for the affinity, although not the specificity, of these agonist ligands for the different dopamine receptor subtypes. Such models will be useful for establishing structure-function relationships between ligands and the dopamine receptors, and may ultimately provide a template for the design of receptor-specific drugs.


A novel transglutaminase-catalyzed posttranslational modification of HIV-1 aspartyl protease. We demonstrate that HIV-1 aspartyl protease (AP), the enzyme essential for the maturation of the AIDS virus, covalently incorporates spermidine catalyzed by guinea pig liver transglutaminase (TGase) and human coagulation factor XIIIa. Preliminary evidence indicates that there are at least three reactive glutamyl and lysyl residues in AP which act as acyl donor and acceptor respectively in a TGase reaction. SDS-PAGE and chromatographic analyses indicate that the two TGases tested catalyze the incorporation of radioactive spermidine into pure HIV-1 AP. The chemical identification and quantitation of (gamma-glutamyl) spermidine isopeptide provide conclusive evidence that the formation of this derivative is catalyzed by TGase. These results imply that TGase-catalyzed post-translational modification of HIV-1 AP may take place in a manner similar to the ones demonstrated in porcine pancreatic phospholipase A2.


A model of cytosolic calcium regulation and autacoids production in vascular endothelial cell. A model of vascular endothelial cell is proposed to describe the mechanisms by which cytosolic calcium (Cai) is modulated and endothelium-derived relaxing factor (EDRF) and prostacyclin (PGI2) are released when the cell is stimulated by agonist. The intracellular Ca2+ store of the model cell is comprised of a superficial (sc) and a deep (dc) compartment. The dc Ca2+ content is refilled by the sc whose [Ca2+] is the same as extracellular Ca2+. Inositol (1,4,5)-trisphosphate (IP3) produced by agonist modifies the dc permeability which discharges its Ca2+ to the cytosol. The increase of Cai induces Ca2+ released from the sc. Ca(2+)-activated K+ current hyperpolarises the cell. The raised Cai releases PGI2 in the presence of IP3 while EDRF is released by Cai. The model explains satisfactorily the Ca2+ transient and autacoids production of the aortic endothelial cell without the need of calcium influx from extracellular space. The cytoplasmic Ca2+ oscillations observed in human endothelial cell from umbilical veins were reproduced by the model. Production of EDRF by the artery due to increase in pressure was also simulated.


Hypotensive effect associated with a phospholipase C-delta 1 gene mutation in the spontaneously hypertensive rat. To identify the genes responsible for blood pressure in the spontaneously hypertensive rat strain, we performed a cosegregation analysis between the genotype and blood pressure in a set of male F2 rats obtained by crossmating SHR with Wistar-Kyoto rats, a parental normotensive strain. Our investigation revealed that the phospholipase C-delta 1 polymorphism, which resulted in missense mutation, cosegregates with the lower blood pressure in SHR, and that PLC-delta 1 gene is located on chromosome 8. On the other hand, we found the lack of cosegregation between blood pressure and the nerve growth factor receptor gene, which is linked to a hypertensinogenic gene locus (denoted as BP/SP-1) on chromosome 10. We propose that PLC-delta 1 gene itself of closely linked gene on chromosome 8 is a new candidate with the hypotensive effect, and that BP-SP1 locus does not directly contribute to blood pressure elevation in original SHR.


Effect of the weak Ca(2+)-binding site of subtilisin J by site-directed mutagenesis on heat stability. The functional role of the negatively charged amino acid residue in subtilisin J from Bacillus stearothermophilus has been investigated by site-directed mutagenesis. Glu-195 located at the weak Ca2+-binding site was replaced with Gln to examine the role of Glu-195 in the heat stability of subtilisin J. Mutant enzyme was expressed in Bacillus subtilis and was purified from the culture supernatant. When the mutant enzyme was expressed at 37 degrees C in the presence of 2mM calcium chloride, the pattern of enzyme production was quite different from that of wild-type. The purified Gln-195 mutant enzyme was analyzed with respect to optimal temperature, optimal pH, and heat stability. The mutation was found to decrease the heat stability but not catalytic efficiency (kcat/Km) and optimal pH. These results demonstrate the important role of the negatively charged side chains at the weak Ca(2+)-binding site in the heat stability of subtilisin.


Expression of only one of two types of mRNA transcribed from the serine dehydratase gene is repressed in hepatoma cells. The expressions of mRNA for serine dehydratase in H4IIE, HTC, and HepG2 hepatoma cells were investigated. Of the two types of mRNA transcribed from the single copy of the rat serine dehydratase gene, expression of only that encoding 35 kDa serine dehydratase is repressed in these cells. The other type coding the 8.9 kDa truncated translation product is expressed at a similar level to that in hepatocytes in primary culture and is not under hormonal control.


P-glycoprotein possesses a 1,4-dihydropyridine-selective drug acceptor site which is alloserically coupled to a vinca-alkaloid-selective binding site. [3H]Vinblastine bound with high affinity to surface membranes prepared from H69/LX4 cells which express P-glycoprotein (P-gp) and as a consequence are multidrug resistant (MDR). The KD was 9.8 +/- 1.5 nM and density of sites 31.2 +/- 8.6 pmol/mg of protein. [3H]Vinblastine binding was inhibited by cytotoxics and agents known to reverse MDR. 1,4-Dihydropyridine MDR reversing agents including nicardipine and nifedipine accelerated the dissociation of [3H]vinblastine from P-gp indicating a negative heterotropic allosteric effect. Cyclosporin A, vincristine and actinomycin D did not alter [3H]vinblastine dissociation kinetics. It is concluded that P-gp possesses at least two allosterically coupled drug acceptor sites, receptor site-1 that is selective for vinca alkaloids and cyclosporin A, and receptor site-2 that is selective for 1,4-dihydropyridines.


Isolation of [Pro2,Met13]somatostatin-14 and somatostatin-14 from the frog brain reveals the existence of a somatostatin gene family in a tetrapod. Two somatostatin-related peptides were isolated in pure form from an extract of the brain of the European green frog, Rana ridibunda. The primary structure of the most abundant component was identical to that of mammalian somatostatin-14. The primary structure of the second component, present in approximately 5% of the abundance of somatostatin-14, was established as Ala-Pro-Cys-Lys-Asn-Phe-Phe-Trp-Lys-Thr-Phe-Thr-Met-Cys. This sequence shows two substitutions (Pro for Gly2 and Met for Ser13) compared with mammalian somatostatin-14. The data provide evidence for a somatostatin gene family in tetrapods as well as in teleost fish.


Purification of testicular transglutaminase by hydrophobic chromatography on phenyl-sepharose. We developed a procedure for purification to homogeneity of cytosolic transglutaminase from bovine testes, by means of anion exchange, size exclusion and hydrophobic chromatography. The crucial step is chromatography on Phenyl sepharose, with specific elution by the inhibitor GTP. The enzyme displays the properties of type 2 transglutaminases.


Effects of aging on renal response to parathyroid hormone in vitro. Renal cortex homogenates from aged (greater than 5 y) rabbits showed decreased specific activities of brush border membrane enzymes compared to those from control young (6 m) rabbits but the specific enzyme activities of basolateral membrane, endoplasmic reticulum and mitochondria did not differ between the two groups. The stimulatory effects of parathyroid hormone (PTH) on the Ca(2+)-pump enzyme [(Ca(2+)+Mg2+)-ATPase] activity in kidney cortex homogenates were markedly less in aged rabbits, but the effect of cAMP on this enzyme activity was similar. Moreover, the production of cAMP induced by PTH was markedly less in the renal cortex homogenates from aged rabbits. From these results, we have proposed the following mechanism; aging--decrease in the response of cAMP to PTH in renal cortex--decrease in the stimulatory effect of PTH via cAMP on the Ca(2+)-pump enzyme--decreased reabsorption of Ca2+ from ureter--increased urinary Ca2+ secretion. This pathway may contribute to the worsening of senile osteoporosis.


Thiol-mediated generation of nitric oxide accounts for the vasodilator action of furoxans. Furoxans (1,2,5-oxadiazole-2-oxides) are widely used in organic chemistry as intermediate compounds for the synthesis of various heterocycles. Despite the fact that some furoxans have been found to possess remarkable biological activities, up to now no systematic study on their mode of action has been reported. The aim of the present study was to investigate the molecular mode of the vasodilator action of furoxans. Furoxans, but not the corresponding furazans, concentration-dependently increased coronary flow in an isolated working rat heart preparation. This effect was blunted upon coinfusion with methylene blue. All tested furoxans were demonstrated to increase potently the activity of soluble guanylate cyclase. Enzyme stimulation was found to be mediated by the generation of nitric oxide (NO) following chemical reaction of the furoxans with sulfhydryl groups of low molecular weight thiols and proteins. Furoxans are thus prodrugs which increase the level of cyclic GMP via formation of NO and may therefore be classified as nitrovasodilators. Along with the generation of NO, nitrite and nitrate ions and S-nitrosothiols were formed. The rates of formation of these metabolites, however, did not appear to be related to enzyme stimulation. A tentative reaction scheme that fits the obtained experimental data is proposed. Recently reported cytotoxic, mutagenic, immunosuppressive and anticancer effects of furoxans are discussed in the light of their ability to release NO upon reaction with thiols.


MY-1250, a major metabolite of the anti-allergic drug repirinast, induces phosphorylation of a 78-kDa protein in rat mast cells. Repirinast (MY-5116; isoamyl 5,6-dihydro-7,8-dimethyl-4,5-dioxo-4H-pyrano [3,2-c]quinoline-2-carboxylate) is an anti-allergic drug of demonstrated effectiveness for treating bronchial asthma in humans. MY-1250 (5,6-dihydro-7,8-dimethyl-4,5-dioxo-4H-pyrano [3,2-c]quinoline-2-carboxylic acid), the major active metabolite of repirinast, inhibits antigen-induced histamine release from sensitized rat peritoneal exudate cells (PEC). When purified rat mast cells were treated with MY-1250 (2.5 x 10(-5) M) for 1 min, phosphorylation of a specific mast cell protein of apparent molecular mass of 78 kDa was observed as previously reported for sodium cromoglycate (SCG). Phosphorylation of this protein induced by MY-1250 and SCG occurred in a concentration-dependent manner with IC50 values of 2.0 x 10(-7) and 1.4 x 10(-5) M, respectively. MY-1250 did not inhibit calcium ionophore A23187 (1 microgram/mL)-induced histamine release from rat PEC. In the presence of calcium ionophore A23187 (1 microgram/mL), phosphorylation of this protein induced by MY-1250 was not evident. In conclusion, MY-1250 induced phosphorylation of a 78-kDa protein in rat mast cells and MY-1250 may inhibit histamine release by regulating phosphorylation of this protein in rat mast cells.


Pharmacokinetics of steroidal muscle relaxants in isolated perfused rat liver. Both in humans and animals hepatic elimination is an important factor determining the duration of action of non-depolarizing neuromuscular blocking drugs. To elucidate the hepato-biliary disposition of muscle relaxants the pharmacokinetics of several structurally related but physicochemically distinct steroidal neuromuscular blocking drugs were studied in isolated perfused rat livers. Pharmacokinetics analysis with the DIFFIT computer program enabled the simultaneous fitting of independently measured perfusate disappearance and biliary excretion rate curves using a numerical approach. The hepatic disposition of the steroidal muscle relaxants could be adequately described by a three compartment model with elimination from the peripheral compartment V2 (biliary excretion) and storage in a deep compartment (V3) connected to V2. In addition, for vecuronium only slow ester hydrolysis occurring in V2 and V3 was included in the model. The lipophilicity rather than the relative mobility of the muscle relaxants showed a positive relationship with biliary clearance (Cl20) and the initial hepatic uptake (Cl12), indicating that hepato-biliary transport of these organic cations is highly dependent on the hydrophobic character of the compounds. In addition, net hepatic uptake of the steroidal cations was influenced markedly by transport from the liver to perfusate (hepatic efflux). This hepatic efflux (k21) decreased with increasing lipophilicity. In contrast, the extent of intracellular sequestration into deep compartments, indicated by high k23/k32 ratios, seemed to be inversely related to the lipophilicity of the muscle relaxants and might explain the observed prolonged hepatic storage of some of these compounds. In combination with data from subfractionation studies the results indicate that the pharmacokinetic analysis of the hepatic disposition of steroidal muscle relaxants may be used to evaluate actual transport phenomena participating in the hepatic disposition of these drugs.


Substituted imidazo[1,2-b]pyridazines. New compounds with activity at central and peripheral benzodiazepine receptors. A large range of substituted imidazo[1,2-b]pyridazines have been synthesized, and a number of potent ligands at central benzodiazepine (Bz) receptors on rat brain membranes have been identified in initial binding screens using [3H]diazepam. For those tested more extensively, binding studies conducted in the presence and absence of gamma-aminobutyric acid suggest that they were full receptor agonists. Some preliminary evidence was found suggesting some species selectivity, i.e. several of the compounds were more active in in vivo tests in rats than in mice. The agonist activity of these 2-phenyl (and substituted phenyl) imidazo[1,2-b]pyridazines is consistent with the model of Bz receptor ligands as proposed by Fryer [Raven Press, 1983, pp. 7-20]. Several compounds were identified which had more selective activity at peripheral-type (mitochondrial) Bz binding sites. Thus, substituted imidazo[1,2-b]pyridazines represent yet another class of low molecular mass compounds which have activity at Bz receptor sites.


Effects of acute alcohol intoxication on gluconeogenesis and its hormonal responsiveness in isolated, perfused rat liver. Rats were acutely administered ethanol as a primed constant infusion in order to produce sustained blood ethanol levels of 8-12 or 55-65 mM. At the end of ethanol infusion the livers were either freeze-clamped in vivo or isolated and perfused for metabolic studies. The rate of gluconeogenesis and its responsiveness to phenylephrine (10 microM), prostaglandin F2 alpha (5 microM) and glucagon (10 nM), as well as the redox state of the cytosolic NAD(+)-NADH system were assessed in livers isolated from acutely ethanol-treated rats, and subsequently perfused without ethanol. For liver clamped in vivo, high- but not low-ethanol treatment decreased the ATP content by 31% and slightly increased ADP and AMP content, resulting in a decreased energy charge (11%). Glutamate and aspartate content was also increased in high-dose ethanol-infused rats with no changes in malate and 2-oxoglutarate content. Gluconeogenesis with saturating concentrations of lactate (4 mM)+pyruvate (0.4 mM) was delayed in reaching a plateau in the livers of high-dose ethanol-treated rats and its response to all three stimulators was impaired. Low-dose ethanol treatment only decreased the liver response to phenylephrine. While the perfused livers of low-dose ethanol-treated rats displayed no changes in adenine nucleotide content, the livers of high-dose ethanol-treated rats had a decreased ATP (35%) and an increased AMP (77%) content, paralleled by a fall in the total adenine nucleotides (14%) and energy charge (14%). No differences were observed between the saline- and ethanol-treated rats with respect to malate-aspartate shuttle intermediate concentration in perfused livers. Also, the livers of high-, but not low-dose ethanol-treated rats had a more negative value of NAD(+)-NADH redox state as compared to the livers of control rats. The data suggest that acute ethanol intoxication produces changes in liver metabolism and its responsiveness to hormones/agonists that are demonstrable for at least 2 hr after isolation and perfusion of the liver.


[Computer analysis and comparison of neurotoxin structures from snake and the anemone Radianthus macrodactylus]. Evolutionary trees of proteins analysed by means of computer comparative methods were reconstructed and the level of the structure and functional relationship was revealed. The distance between the percent amino acid contents was used to classify a group of toxins from the sea anemone Radianthus macrodactylus, which proved to belong to long neurotoxins. The scores were calculated by the pattern recognition method. By the use of the distance values, ten phospholipases A2 were divided into two groups, containing representatives of the most closely related organisms.


Use of short-term efficacy/toxicity tradeoffs to select second-line drugs in rheumatoid arthritis. A metaanalysis of published clinical trials. Preferred drugs for rheumatoid arthritis (RA) should be those that have maximal efficacy with the least toxicity. We evaluated the efficacy and toxicity tradeoffs for drugs frequently used in the treatment of RA. We updated 2 metaanalyses of published clinical trials, by adding trials published through 1990 and trials of azathioprine (AZA). We tested 3 different definitions of efficacy, each plotted against 3 different toxicity measures, for antimalarial drugs, methotrexate (MTX), auranofin, injectable gold, D-penicillamine, sulfasalazine (SSZ), AZA, and placebo. Efficacy measures included composite efficacy (a combination of joint count, grip strength, and erythrocyte sedimentation rate), tender joint count alone, and a measure based on how many patients dropped out due to inefficacy. Toxicity measures were the proportion dropping out due to toxicity, the same dropouts with side effects weighted for severity using a modification of a published toxicity index, and the proportion with severe toxicities (defined as a score of at least 7 of 10 on the toxicity index). The latter were usually organ toxicities (e.g., cytopenias and renal involvement). All 9 efficacy/toxicity tradeoff plots suggested that MTX and antimalarial drugs had the highest efficacy relative to toxicity. MTX scored among the most efficacious of the drugs and, of these, had the least toxicity. Antimalarial drugs, though showing only moderate efficacy, had the lowest toxicity rate of all the drugs. SSZ scored close to MTX but was, in general, slightly more toxic. In the short-term context of clinical trials, antimalarial drugs and MTX have the best efficacy/toxicity tradeoffs and may, therefore, be the preferred drugs.


Third International Conference on Systemic Lupus Erythematosus. A Fourth International Conference on Systemic Lupus Erythematosus will be held in Jerusalem in March 1995. We look forward to a better understanding of the molecular, genetic, immunologic, and clinical aspects of the disease and trust that this knowledge will result in improved treatment.


Neuroleptic activity of 10-(4-methyl-1-piperazinyl)-thieno[3,2-b] [1,5]benzoxazepine and benzothiazepine derivatives. Two series of compounds, structurally related to clozapine (CAS 5786-21-0), were tested for their neuroleptic activity. The derivatives 7-chloro-10-(4-methyl-1-piperazinyl)-thieno[3,2-b][1,5]benzoxazepine and 7-chloro-10-(4-methyl-1-piperazinyl)-thieno[3,2-b][1,5]benzothiazepine at high doses were not cataleptogenic and only very weakly antagonized the amphetamine-or apomorphine-induced stereotyped behaviour in the rat, whereas at low doses they antagonized the amphetamine-induced hypermotility in mice. Thus these compounds might be efficient neuroleptics with little propensity to cause extrapyramidal side effects. On the other hand, the unsubstituted compound 10-(4-methyl-1-piperazinyl)-thieno[3,2-b][1,5]benzothiazepine appeared to be an efficient neuroleptic agent with a greater propensity to cause these side effects.


Modification of lymphoid subsets by chronic ethanol consumption in C57Bl/6 mice infected with LP-BM5 murine leukemia virus. The relatively high incidence of infectious disease in alcoholics is attributed to the immunosuppressive effects of alcohol. The potential role of alcohol as cofactor in HIV infection and in the development and expression of AIDS is suggested but unknown. In order to understand better the contribution of alcohol to immune dysfunction following HIV infection, we assessed the presence of specific markers on thymus and spleen cells in C57B1/6 mice infected with LP-BM5 murine leukemia virus and fed ethanol-containing diets. In the first experiments, mice were fed diets containing 0, 4.5, 5.5, and 6% (v/v) ethanol for 14 weeks. High ethanol exposure (6%) resulted in severe dehydration and death after 7 weeks. Although moderately low intakes of ethanol did not significantly modify percentages of T and B cells, they increased the absolute number of mature T, B, and CD4+ cells and decreased percentages of Thy 1.2+ cells. In the second experiment, mice were infected with LP-BM5 murine leukemia retrovirus and fed diets containing 5% ethanol in a regimen of 5 days of ethanol diet and 2 days of diet without alcohol for 12 weeks. Ethanol exposure in the retrovirally infected mice showed a marked decrease in Thy 1.2+ (P < 0.05). Moderate decreases in percentages of CD4+, CD8+, CD5+ cells and an increase in Ia+ cells were also observed in the retrovirus/infected ethanol-treated mice. Moderate ethanol consumption during retroviral infection induced mild/moderate changes on lymphoid cells. Ethanol consumption may accelerate the progression of murine AIDS through such changes in the lymphoid cells of the spleen.


Polyamine metabolism in different pathological states of the brain. Biosynthesis of the polyamines spermidine and spermine and their precursor putrescine is controlled by the activity of the two key enzymes ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC). In the adult brain, polyamine synthesis is activated by a variety of physiological and pathological stimuli, resulting most prominently in an increase in ODC activity and putrescine levels. The sharp rise in putrescine levels observed following severe cellular stress is most probably the result of an increase in ODC activity and decrease in SAMDC activity or an activation of the interconversion of spermidine into putrescine via the enzymes spermidine N-acetyltransferase and polyamine oxidase. Spermidine and spermine levels are usually less affected by stress and are reduced in severely injured areas. Changes of polyamine synthesis and metabolism are most pronounced in those pathological conditions that induce cell injury, such as severe metabolic stress, exposure to neurotoxins or seizure. Putrescine levels correlate closely with the density of cell necrosis. Because of the close relationship between the extent of post-stress changes in polyamine metabolism and density of cellular injury, it has been suggested that polyamines play a role in the manifestation of structural defects. Four different mechanisms of polyamine-dependent cell injury are plausible: (1) an overactivation of calcium fluxes and neurotransmitter release in areas with an overshoot in putrescine formation; (2) disturbances of the calcium homeostasis resulting from an impairment of the calcium buffering capacity of mitochondria in regions in which spermine levels are reduced; (3) an overactivation of the NMDA receptor complex caused by a release of polyamines into the extracellular space during ischemia or after ischemia and prolonged recirculation in the tissue surrounding severely damaged areas; (4) an overproduction of hydrogen peroxide resulting from an activation of the interconversion of spermidine into putrescine via the enzymes spermidine N-acetyltransferase and polyamine oxidase. Insofar as a sharp activation of polyamine synthesis is a common response to a variety of physiological and pathological stimuli, studying stress-induced changes in polyamine synthesis and metabolism may help to elucidate the molecular mechanisms involved in the development of cell injury induced by severe stress.


Serotonin 5-HT1-like receptors mediate hyperactivity in rats induced by 3,4-methylenedioxymethamphetamine. This study was designed to evaluate the role of different serotonin (5-HT) receptor subtypes in mediating the effects of 3,4-methylenedioxymethamphetamine (MDMA) on rat exploration of a novel environment. The active enantiomer of MDMA, S-MDMA increases forward locomotion and suppresses investigatory behaviors and local movements. Previous studies indicate that S-MDMA-induced hyperactivity depends upon drug-induced 5-HT release. Propranolol and pindolol, beta-noradrenergic antagonists with affinity for 5-HT1 receptors, antagonized the S-MDMA-induced locomotor hyperactivity. The antagonism by propranolol was stereoselective. In contrast, a beta-noradrenergic antagonist that is a weaker antagonist of 5-HT receptors, betaxolol, was much less effective at blocking the behavioral response to S-MDMA. Among nonselective 5-HT antagonists, methiothepin was effective and methysergide and cyproheptadine were ineffective as antagonists of S-MDMA-induced hypermotility. In other systems, methiothepin has been found to be a good antagonist at 5-HT1B receptors where methysergide and cyproheptadine are ineffective. The 5-HT2 antagonist ritanserin was ineffective in blocking S-MDMA-induced hypermotility. However, ritanserin, methysergide, and cyproheptadine partially reversed the S-MDMA-induced suppression of investigatory responding, suggesting a contribution of 5-HT2 receptor activation to this component of the behavioral response to S-MDMA. This study indicates that S-MDMA produces a characteristic form of locomotor hyperactivity in rats that depends upon activation of 5-HT1-like receptors, possibly of the 5-HT1B subtype.


Progressive and selective impairment of IL-3 and IL-4 production by peripheral blood CD4+ T-lymphocytes during the course of HIV-1 infection. The amounts of interleukin 3 (IL-3), interleukin 4 (IL-4), tumor necrosis factor alpha (TNF-alpha), and tumor necrosis factor beta (TNF-beta) were evaluated by immunoenzymatic assays in the supernatant of short-term cultures of whole mononuclear cells and purified CD4+ T-lymphocytes, obtained from the peripheral blood (PB) of 35 HIV-1(+) asymptomatic individuals (stages I-II of the Walter Reed Classification), 20 HIV-1(+) symptomatic patients (WR V-VI), and 40 HIV-1(-) blood donors. TNF-alpha and TNF-beta production was similar in HIV-1(+) asymptomatic individuals, HIV-1(+) symptomatic patients, and HIV-1(-) controls. On the other hand, IL-3 and IL-4 production by either whole mononuclear cells or isolated CD4+ T-cells was decreased approximately 2-fold (p < 0.01) in HIV-1(+) asymptomatic subjects with respect to HIV-1(-) blood donors and was very low or almost absent in HIV-1(+) symptomatic individuals. The reduced IL-3 and IL-4 production in HIV-1-infected subjects correlated not only with the stage of the disease, but also with signs of active viral replication in PB cells, monitored by gag p24 antigen in plasma and viral isolation from PB mononuclear cells. This selective and progressive impairment in IL-3 and IL-4 production by CD4+ T-lymphocytes of HIV-1-infected subjects may contribute to explain the hematopoietic abnormalities and the derangement of the inflammatory/immune system characteristic of AIDS.


Programmed cell death and AIDS: from hypothesis to experiment. Here, Jean Claude Ameisen discusses new findings supporting the hypothesis that abnormal induction of programmed cell death (PCD) is relevant to AIDS pathogenesis. Recent evidence also suggests that the prevention of PCD is a factor in oncogenesis. Together, these ideas provide a framework for the reinterpretation of cell survival disorders in terms of PCD dysregulation, and suggest that in vivo control of cell signalling has wide-ranging therapeutic potential.


Effect of somatostatin on prolactin in rainbow trout (Oncorhynchus mykiss) pituitary cells in primary culture. To study the control of prolactin secretion in fish, an in-vitro technique using a monolayer cell culture system of rainbow trout pituitary glands was developed. Such secretion was characterized by measurement of both prolactin release and prolactin mRNA content using a trout prolactin cDNA as a probe. This cell culture technique, already used to study the regulation of gonadotrophin secretion in rainbow trout, was further validated by measuring total DNA and protein content. Both parameters appeared to be stable after 2 days of culture. Studying the effect of somatostatin (SRIF) on prolactin cells indicated that a maximal inhibitory effect (62%) was observed after 24 h of treatment. Significant inhibition of prolactin release was obtained for SRIF doses ranging from 50 nM to 1 microM. However, in the same experiment, SRIF was much more potent as an inhibitor of growth hormone release. Short-term (< 12 h) incubation with SRIF did not induce a significant change in prolactin release, whereas growth hormone release was reduced at as early as 1 h after SRIF exposure. SRIF did not have a significant effect on total prolactin content or prolactin mRNA levels, suggesting the absence of an effect on prolactin synthesis. No increase in the magnitude of the inhibitory effect of SRIF was observed when using pituitary cells from immature, mature male or mature female trout. When comparing effects on primary cultures containing cells from the whole pituitary with a prolactin cell-enriched population, SRIF appeared to have the same inhibitory effect on prolactin release, supporting a direct action of SRIF on prolactin cells. These results provide further support for SRIF being a prolactin-inhibiting factor in rainbow trout and acting as a modulator of a dominant stimulatory control of prolactin release.


Significant compatibility does not exist at the HLA-DQB gene locus in couples with unexplained recurrent abortions. The polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP) method was used for both examining compatibility at the HLA-DQB1 gene locus and determining HLA-DQ antigen polymorphism in spouses of unexplained recurrent abortions. Genomic DNA samples were prepared from peripheral mononuclear cells from patient and control couples. Two hundred and thirty base pair fragments of the second exon of the HLA-DQB genes were selectively amplified. Amplified DNAs were digested with the restriction endonucleases, Fok I, Hae III, Hha I, Rsa I and Sau3A I, and subjected to electrophoresis in a polyacrylamide gel. The RFLPs showed that habitual aborters and their husbands had neither significantly frequent alleles nor shared common alleles at the HLA-DQB locus when compared to the control group. Since significant HLA-DQB compatibility was not observed between the spouses and unexplained recurrent aborters, in order to determine whether or not HLA compatibility is responsible for the genesis of unexplained recurrent abortions, it is imperative to further examine the compatibility between other HLA gene loci.


The noisy elderly patient: prevalence, assessment, and response to the antidepressant doxepin. To measure the prevalence of noisy behavior as a nursing problem, a survey of head nurses was done in a chronic care hospital to identify patients whose vocalizing was frequently disturbing to other patients, staff, or visitors. We found 17 patients among the total of 154. Subsequently, the medical records of 13 surviving subjects were reviewed more exhaustively, and 11 were described as disruptive, usually when they were left alone. Of these "lonely" patients, eight had a previously documented diagnosis of depression. All were demented. Antipsychotic medication had previously been given to all 11 "lonely" patients, but had failed to control their disruptive behavior. Empirically, six patients were treated with doxepin, and in five, all with a history of previous depression, agitation and noisiness diminished. These observations suggest that the prevalence rate of disturbingly noisy behavior among long-term institutionalized elderly patients is about 11% and that the disturbingly noisy patient is often demonstrating depression in conjunction with dementia.


Biology of the chicken MHC (B complex).

Biology of the chicken MHC (B complex). The major histocompatibility complex (MHC) of chicken is the B complex, originally described as a blood group system. Its three classes of cell membrane antigens have been clearly defined by serological, histogenetic, biochemical, and molecular biological methods. Two of these classes are homologous to classes I and II of mammals (B-F and B-L respectively), while the third--B-G antigen--has not so far been detected in mammals. The possible role of this antigen is discussed. The genes of the MHC play important roles in the regulation of immune response, disease resistance, and regression of Rous sarcomas.


Interference of substrate quenching with the kinetics of placental peptidases. The study was undertaken to clarify the putative presence and influence of substrate inhibition and substrate quenching on the kinetic analysis of placental peptidases using naphthylamide substrates in a fluorometric assay. Using the appropriate naphthylamide substrates, we analysed microsomal alanine aminopeptidase (EC 3.4.11.2) and angiotensinase A (EC 3.4.11.7) in the presence or absence of inhibitors (1,10'-phenanthroline, EDTA) or activators (calcium) in the human and rat placenta. All substrates were shown to quench the fluorescence of the enzymatically released unspecific moiety. Since Michaelis-Menten-derived kinetic equations do not include quenching phenomena, we deduced a mathematical model integrating enzyme kinetics and quenching kinetics, thereby allowing simultaneous analysis of both processes from the same raw data. Curves derived from this expanded kinetic model fitted significantly better to velocity data than those derived from Michaelis-Menten-equation. According to the presented data, we assume that substrate inhibition for both enzymes, as previously proposed in the literature, in contrast may be due to formerly unconsidered substrate quenching. The presented kinetic model could serve as a useful tool in the study of putative physiological substrates of the investigated placental peptidases, characterizing the physiologic substrates by their competitive interaction with the synthetic naphthylamides. Additionally, this model may not only be important in fluorometric analysis of peptidases, but also of other enzymes which are analysed fluorometrically with synthetic substrates.


Aluminium administered in drinking water but not in the diet influences biopterin metabolism in the rodent. To investigate the neurotoxic effects of aluminium (Al) Al was administered: 1) in the diet of the rat (30 mg Al/kg body weight for 6 weeks); 2) as a suspension of aluminium acetate in drinking water of the rat for 3 months and 3) in a long-term study in the mouse in which aluminosilicates were incorporated into a pelleted diet (1035 mg/kg of food over 23 months). In the latter treatment, increased Al was combined with a reduction in calcium and magnesium; a treatment designed to increase absorption of Al into the body. Administration of Al in the drinking water significantly reduced total brain biopterins and BH4 synthesis. However, no significant affect of Al in the diet on total biopterins or BH4 synthesis was found either in the rat or in the long-term study in the mouse. In addition, in the mouse no significant effects of the Al diet on levels of noradrenaline, serotonin, dopamine, 5-HIAA or CAT could be demonstrated. Hence, the occurrence of brain alterations may depend on the Al species present and the method of administration. Al salts in drinking water may increase brain tissue levels compared with the administration of a more insoluble species. Since alterations in biopterin metabolism are also a feature of Alzheimer's disease (AD) these results support the hypothesis that Al in the water supply may be a factor in AD.


Large artery compliance in essential hypertension. Effects of calcium antagonism and beta-blocking. This study used 2D Doppler flowmetry to assess the effects on peripheral hemodynamics of effective treatment with nicardipine or atenolol in 40 patients with mild or moderate essential hypertension. Two groups of 20 patients received treatment with nicardipine or atenolol, respectively, for 8 months. Consequently, those patients considered to be responders (blood pressure less than 150/90 mm Hg) were monitored for another 4 weeks after the therapy was suspended in order to determine whether the changes, if any, in arterial compliance persisted. Following the 8-month therapy, four patients from each group were excluded from the study because of unsatisfactory blood pressure levels. After the treatment, there was a decrease in blood pressure in both groups (P less than .01). In the nicardipine group, there was a significant increase in diameter and compliance (P less than .01), whereas pulse wave velocity and resistance decreased (P less than .01). In the atenolol group, these parameters did not change significantly. After therapy was ended, blood pressure returned to baseline values in both groups. However, in the nicardipine group, the observed improvement in forearm hemodynamics persisted. This result may indicate that nicardipine is able to induce a regression of functional and/or structural changes in the large arteries of hypertensive patients.


Benzodiazepine antagonists. An update of their role in the emergency care of overdose patients. The benzodiazepine antagonist flumazenil is a very valuable tool in the diagnosis and treatment of intoxications in which benzodiazepines are involved. In case of a positive response, patients will regain consciousness immediately, thus verifying the diagnosis and making a brief history possible to identify other drugs that might be involved. Moreover, invasive diagnostic and therapeutic procedures like gastric lavage, lumbar puncture, mechanical ventilation, etc., may then be unnecessary. In cases of pure benzodiazepine overdose a single injection of flumazenil 0.2mg should be given, followed by individually titrated increments of 0.1 mg/min until the patient is awake and responsive. In these cases a total dose of 2mg is usually sufficient. Higher doses of flumazenil may be necessary in cases of combined drug overdose. Because of its high therapeutic index, the administration of flumazenil is usually not accompanied by serious adverse effects. Benzodiazepine withdrawal syndromes characterised by transient anxiety and depression can occur, but the incidence is low. Increases of blood pressure and heart rate due to a release of catecholamines are possible, which might endanger patients with cardiovascular diseases. In severe cases, seizures have been observed which usually respond well to small doses of benzodiazepine agonists. In all cases of successful treatment it should be remembered that the effect of flumazenil deteriorates after 1 to 2h, which usually leads at first to resedation. In these patients additional bolus injections or a continuous infusion (0.1 to 0.5 mg/h) may be necessary. The effectiveness of flumazenil in cases of alcohol (ethanol) poisoning is questionable and should be further investigated.


Pharmacologic properties of (-)-3PPP (preclamol) in man. The dopamine (DA) autoreceptor agonist (-)-3PPP (preclamol) was tested in male schizophrenic volunteers for safety. The drug was administered intramuscularly in a single rising dose design, crossed with a similar "rising dose" placebo period; all evaluations and raters were blind to drug or placebo administration. Pharmacokinetic, endocrine, safety, and mental status outcome measures were completed before and after each single dose of drug or placebo. Pharmacokinetic analysis showed blood levels between 200-500 pmoles/ml after the intramuscular drug doses of 30-40 mg. Drug half life is 2-2.5 hrs. Growth hormone (GH) levels were elevated in a linear fashion to the 30 mg dose; whereafter, the drug failed to affect GH at all. All safety evaluations were negative, including any untoward effects on the major organ systems. After single dose drug administration, evidence of antipsychotic action occurred in two of the four subjects. This study suggests that (-)-3PPP/preclamol is a safe drug for study in the treatment of schizophrenia and may have antipsychotic efficacy.


Distributions and colocalization of neuropeptide Y and somatostatin in the goldfish brain. The distributions of single- and double-labelled neuropeptide Y- (NPY-) and somatostatin-immunoreactive (SOM-IR) perikarya and processes were determined in the goldfish brain using immunoperoxidase and immunofluorescence techniques, respectively. In double-labelled material, it was evident that although these two peptides showed markedly similar distributions, they were colocalized in very few instances. A high degree of colocalization of NPY and SOM was noted in the neurons of the ventrolateral telencephalon (VI), the entopenduncular nucleus (NE) and, to a lesser extent, in the dorsocentral nucleus of the telencephalon (Dc). In Vl and NE, neurons showing NPY-IR displayed SOM-IR and vice versa. The only other instance of colocalization was that noted in the brainstem, where SOM and NPY were colocalized in the large cell bodies of the medial column of the vagal motor complex. Single-labelled SOM- and NPY-IR neurons shared a very similar distribution in various nuclei in the diencephalon and in the optic tectum. Colocalization was also noted within fibers throughout many nuclei of the telencephalon and within fibers innervating the swim bladder, one of the peripheral organs to which neurons of the medial column of the vagal motor complex project. Processes in the torus semicircularis and vagal lobe showed single-labelled immunoreactivity for both SOM and NPY in distinct laminar patterns. Large single-labelled SOM-IR terminals appeared to form pericellular baskets in the eminentia granularis of the cerebellum. Single-labelled NPY- or SOM-IR fibers were also found in the secondary gustatory nucleus and tract, the facial lobe, descending trigeminal tract, reticular formation and spinal cord. As in mammalian species, select groups of neurons in teleosts colocalize the neuropeptides SOM and NPY.


D1-receptor antagonists: comparison of [3H]SCH39166 to [3H]SCH23390. A radiolabeled form of the benzonaphthazephine, SCH39166 was used to characterize the binding of this D1 antagonist in cortex, and an autoradiographic comparison of the localization of [3H]SCH39166 to [3H]SCH23390 (D1 antagonist and forerunner of SCH39166) binding was performed. The Kd for [3H]SCH39166, calculated from dissociation and association rate constants (1.09 nM), was comparable to the Kd value derived from Scatchard analyses of saturation data (1.74 nM). [3H]SCH39166 binds to brain tissue in a saturable manner with high affinity and low non-specific binding. Inhibition of [3H]SCH39166 binding by dopaminergic and serotonergic agents supports the hypothesis that this is indeed a D1-specific compound with little overlap onto serotonin (5-HT) receptors. The affinity of [3H]SCH39166 for 5-HT2 and 5-HT1c receptors is at least an order of magnitude lower than the affinity of [3H]SCH23390 for these same receptor sites. Quantitative autoradiographic analysis of [3H]SCH39166 and [3H]SCH23390 binding indicates high D1-receptor density in the caudate-putamen, nucleus accumbens, olfactory tubercle, substantia nigra and entopeduncular nucleus. Low levels of binding (not significantly above background) were detected with [3H]SCH39166 in lamina IV of the cortex and in choroid plexus; areas which had significant [3H]SCH23390 binding and are known to have a high density of 5-HT (5-HT2 and 5-HT1c respectively) receptors.


Cholinergic mechanisms in physical dependence on barbiturates, ethanol and benzodiazepines. The aim of this review is to summarize the effects of acute and chronic treatment with barbiturates, ethanol and benzodiazepines on cholinergic mechanisms in the brains of experimental animals. A single dose of each of these substances reduces the turnover of ACh in the brain. Long-term treatment has the opposite effect; complicated interactions including decreased content of ACh are induced. Barbiturates have been shown to bind stereospecifically to muscarinic and nicotinic receptors in the brain, but this has not been observed for ethanol or the benzodiazepines. The effects on the cholinergic system are affected by the length of treatment and choice of treatment regimen. No effect on cholinergic parameters, such as muscarinic receptors, in the brain is observed on withdrawal of ethanol or barbiturate treatment when the animals are still tolerant towards the substances. The increase in the number of muscarinic receptors observed in several brain regions on withdrawal is seen as a sign of cholinergic supersensitivity. The number of receptors returns to normal when abstinence convulsions have occurred. The assumption of a cholinergic influence is supported by the finding that atropine, given as a single dose on the day of withdrawal of barbital, can prevent the muscarinic receptor changes. Furthermore, long-term barbital or ethanol treatment can induce permanent persistent changes in the cholinergic system in the brain. Cognitive defects and a significant permanent reduction in the content of ACh can be measured in rats which have had long-term barbital treatment. Similarly, a reduced number of muscarinic receptors has been measured in different brain regions of chronic alcoholics. Accumulating data support the role of the cholinergic system in expressing symptoms of physical dependence on barbiturates, ethanol and benzodiazepines as well as in the permanent long-term effects observed after end of treatment.


Interaction between glutamatergic and dopaminergic tone in the nucleus accumbens of mice: evidence for a dual glutamatergic function with respect to psychomotor control. The rotation induced by a unilateral injection of the competitive NMDA receptor antagonist AP-5 was studied in mice with different tone in the central dopaminergic systems. AP-5 induced contralateral rotation in monoamine-depleted mice and in monoamine-depleted mice treated with a dopamine D-1 receptor agonist. In contrast, AP-5 induced predominantly ipsilateral rotation in monoamine-depleted mice treated with a mixed D-1/D-2 or a D-2 selective dopamine agonist and in mice with intact monoaminergic systems.


Typical and atypical neuroleptics antagonize MK-801-induced locomotion and stereotypy in rats. The effects of typical and atypical neuroleptics on MK-801-induced locomotor activity and stereotyped sniffing were tested. Pretreatment with the typical neuroleptic haloperidol (0.01, 0.05, 0.1, 0.5 mg/kg SC) and the dopamine D2 receptor selective antagonist eticlopride (0.005, 0.01, 0.05 mg/kg SC) each resulted in significant and dose-dependent reductions of locomotor activity and sniffing. The atypical neuroleptic clozapine (1.0, 5.0, 10.0 mg/kg SC) was somewhat unique in that all doses reduced locomotor activity, but only the highest dose (10.0 mg/kg) significantly reduced sniffing. The data support a functional interaction between glutamate and dopamine systems, and suggest that the behavioral activation associated with MK-801 may represent a valid model for detecting potential therapeutic agents in the treatment of schizophrenia. The data should be viewed as preliminary, however, until neuroleptics are characterized in other glutamate-based models that minimized or exclude the possible influence of nonspecific motor effects.


Neurochemical evidence for a neuronal GABAergic system in the rat sympathetic superior cervical ganglion. Some characteristics of gamma aminobutyric acid (GABA) uptake and release in rat superior cervical ganglion (SCG) were investigated. Kinetic analysis of GABA uptake indicated the existence of both high affinity (Km = 18.6 microM) and low affinity (Km = 485 microM) uptake systems. 3H-GABA influx was decreased by inhibitors of glial (beta-alanine), neuronal (2,4-diaminobutyric acid, DABA), or glial and neuronal GABA uptake (nipecotic acid). 3H-GABA efflux was elicited by K+ depolarization in a dose-dependent manner, an effect unaltered by severing the preganglionic nerve fibers. Superfusion of SCG explants with DABA or beta-alanine resulted in increased 3H-GABA efflux from tissue, an effect amplified by the absence of calcium in the superfusion medium. 3H-GABA loading in the presence of DABA, but not in the presence of beta-alanine, resulted in abolition of K(+)-elicited 3H release. At 20 mM, but not at 50 mM K+, the release of 3H-GABA was inhibited by replacing Ca2+ by Mg2+ and by adding EGTA, or by incubating SCG in the presence of the Ca(2+)-channel blocker verapamil. Veratrine evoked GABA release in Ca(2+)-independent manner. None of several putative SCG autacoids or agonists (nicotine, muscarine, norepinephrine, dopamine, serotonin, baclofen, muscimol) significantly modified GABA release.


The importance of serotonin-dopamine interactions in the action of clozapine. Clozapine has an affinity for the dopamine (DA) D2 receptor which is relatively weak but is in line with its average clinical dose when compared with typical neuroleptic drugs. A few atypical antipsychotic drugs may have high absolute affinities for the D2 receptor, but most are weak D2 blockers. The atypical antipsychotic drugs also differ from the typical antipsychotic drugs by a relatively high affinity for the serotonin (5-HT2) receptor. This is evident on both in vitro and in vivo binding to cortical 5-HT2 receptors. The atypical antipsychotics are best distinguished from the typical antipsychotics on the basis of the relationship between strong 5-HT2 and weak D2 affinities. High D1 receptor binding is not characteristic of the group of atypical drugs. A new group of putative atypical antipsychotic drugs with high affinities for 5-HT2 compared to D2 receptors is under study.


PET analysis indicates atypical central dopamine receptor occupancy in clozapine-treated patients. D1 and D2 dopamine (DA) receptor occupancy was determined by PET in the basal ganglia of drug-treated schizophrenic patients. In 22 patients treated with classical neuroleptics at conventional doses, the average D2 occupancy was 78% (s.d. 6%). In five patients treated with the prototype atypical antipsychotic drug clozapine, a lower D2 occupancy of 48% (s.d. 11%, P less than 0.01) was found. Accordingly, clozapine is 'atypical' with respect to the striatal D2 DA receptor occupancy induced in patients. No obvious D1 DA receptor occupancy was induced by the classical neuroleptics haloperidol or sulpiride. The thioxanthene flupenthixol induced a 36-44% D1 occupancy in individual patients. In four patients treated with clozapine the D1 occupancy was 38-52%.


General pharmacology of clozapine.

General pharmacology of clozapine. Clozapine shows neuroleptic-like inhibition of locomotor activity and conditioned avoidance responding in rodents, although tolerance develops on repeated treatment. EEG-based studies show strong arousal-inhibiting activity of clozapine as well as neuroleptic-like effects on both caudate spindle duration and rat sleep-waking patterns. Effects such as apomorphine blockade, catalepsy and strong increases of plasma prolactin levels are not seen, however, and chronic treatment does not lead to dopamine D2 receptor supersensitivity. Binding studies show clozapine's highest affinities to be for dopamine D4, 5-HT1C, 5-HT2, alpha 1, muscarinic and histamine H1 receptors, but moderate affinity is also seen for many other receptor subtypes. Microdialysis studies indicate a preferential interaction with striatal D1 receptors, whereas autoradiographical studies indicate upregulation of D1 and downregulation of 5-HT2 receptors after chronic clozapine. Clarification of the mechanisms underlying clozapine's special attributes is often hampered by a failure to examine compounds which show a close chemical relationship to clozapine, but which produce extrapyramidal side-effects in man, such as clothiapine, loxapine and amoxapine.


Clinical management of clozapine patients in relation to efficacy and side-effects. Medical charts of 480 schizophrenic in-patients (581 treatments) were analysed to evaluate the efficacy and side-effects of clozapine. Clozapine treatment lasted for mean 49 (s.d. 38) days. Of the sample, 11.0% showed worsening or no change, 31.5% slight improvement, 53.0% marked improvement and 4.5% almost total reduction of symptoms. At least one major side-effect occurred in 68.0% of patients. A combination of clozapine with classical neuroleptics, antidepressants, benzodiazepines or lithium is tolerated by most patients, but increases the incidence of some side-effects. Clozapine treatment had to be discontinued because of severe side-effects in 8.6% of patients. In 81 schizophrenic out-patients, clozapine significantly reduced the days of in-patient treatment and number of hospital readmissions. Two patients developed leucopenia but had no complications after clozapine withdrawal. This study indicates a satisfactory benefit/risk ratio and compliance in most of the patients.