Basic aspects of GABA-transaminase in neuropsychiatric disorders

Over the last two decades, there have been several studies suggesting the major inhibitory amino acid neurotransmitter gamma-aminobutyric acid (GABA) is involved directly and/or indirectly in the pathogenesis of many neurologic diseases and psychiatric disorders. GABA is mainly degradated to succinic semialdehyde in a reaction catalyzed by the enzyme GABA-transaminase (GABA-T). Inhibition of this enzyme produces considerable elevation of GABA contents in the brain, and such elevation has been found to correlate with pharmacologic and behavioral effects. We focus attention, from the basic aspects, on brain and platelet GABA-T activities in various species, with a special reference to neuropsychiatric disorders. It seems that the activity of GABA-T in the brain and/or in the blood platelets is correlated to certain neuropsychiatric disorders such as alcoholism, epilepsy, and Alzheimer's disease. In animal and human studies, platelet GABA-T was identified with similar kinetic and inhibitor characteristics to those of the brain. Therefore, in this way, studies of the activity of the enzyme GABA-T in relation to neuropsychiatric disorders could be undertaken to understand, diagnose, and treat GABA-related disorders of the central nervous system.

Induction of murine gamma delta T cells cytotoxic for xenogeneic rat cells

C57BL/6 mice deprived or nondeprived of CD4+ and CD8+ T cells by mAbs were challenged with a rat T cell line, W7TM-1. Spleen cells obtained from CD4- and CD8-depleted animals rejecting W7TM-1 were examined by cytofluorometry, which demonstrated the presence of highly increased gamma delta type CD4-CD8- T cell population (30 to 50% of entire T cells). In vitro sensitization of these spleen cells with W7TM-1 generated a mixture of gamma delta and alpha beta type CD4-CD8- CTL for W7TM-1. Repeated stimulation of these cells with W7TM-1 resulted in a gamma delta-type T cell population with more than 95% purity by day 45. In contrast, alpha beta type CD8+ CTL for W7TM-1 were induced from mice nondeprived of CD4+ and CD8+ T cells. Both gamma delta-type CD4-CD8- CTL and alpha beta type CD8+ CTL were cytotoxic for rat cells in a species-specific manner. However, only reactivity of gamma delta type CD4-CD8- CTL, but not alpha beta type CTL, was inhibited by a mAb for TCR-gamma delta. The gamma delta type CD4-CD8- CTL clones were also prepared from spleen cells derived from CD4- and CD8-depleted mice. They were also reactive for xenogeneic cells in a species-specific manner. Spleen cells derived from CD4- and CD8-depleted mice rejecting the whole-layer rat skin grafts were in vitro sensitized with rat spleen cells, which also generated gamma delta type CD4-CD8- CTL specific for rat cells. V gamma 1 was detected as a major V gamma gene expressed in this gamma delta population by reverse transcriptase-PCR. Cytotoxicity for xenogeneic cells may represent one of major function of gamma delta T cells.

Induction of murine gamma delta T cells cytotoxic for xenogeneic rat cells

C57BL/6 mice deprived or nondeprived of CD4+ and CD8+ T cells by mAbs were challenged with a rat T cell line, W7TM-1. Spleen cells obtained from CD4- and CD8-depleted animals rejecting W7TM-1 were examined by cytofluorometry, which demonstrated the presence of highly increased gamma delta type CD4-CD8- T cell population (30 to 50% of entire T cells). In vitro sensitization of these spleen cells with W7TM-1 generated a mixture of gamma delta and alpha beta type CD4-CD8- CTL for W7TM-1. Repeated stimulation of these cells with W7TM-1 resulted in a gamma delta-type T cell population with more than 95% purity by day 45. In contrast, alpha beta type CD8+ CTL for W7TM-1 were induced from mice nondeprived of CD4+ and CD8+ T cells. Both gamma delta-type CD4-CD8- CTL and alpha beta type CD8+ CTL were cytotoxic for rat cells in a species-specific manner. However, only reactivity of gamma delta type CD4-CD8- CTL, but not alpha beta type CTL, was inhibited by a mAb for TCR-gamma delta. The gamma delta type CD4-CD8- CTL clones were also prepared from spleen cells derived from CD4- and CD8-depleted mice. They were also reactive for xenogeneic cells in a species-specific manner. Spleen cells derived from CD4- and CD8-depleted mice rejecting the whole-layer rat skin grafts were in vitro sensitized with rat spleen cells, which also generated gamma delta type CD4-CD8- CTL specific for rat cells. V gamma 1 was detected as a major V gamma gene expressed in this gamma delta population by reverse transcriptase-PCR. Cytotoxicity for xenogeneic cells may represent one of major function of gamma delta T cells.

Missed opportunities for immunization in children under 2 years attending an urban teaching hospital

A cross-sectional survey was done to assess the missed opportunity for immunization (MOI) in children under two years of age attending Medical Outpatient, Newborn Follow-up Service and Immunization Clinic of Institute of Child Health and to evaluate interventions. Baseline survey phase-I was done and two interventions: (i) education and awareness of immunization among health personnel; and (ii) attaching immunization slip to the outpatient form were done. After each intervention phase-II and phase-III surveys were carried out. The data from the different phases were analyzed for the effect of interventions. The total number of children surveyed were 634; 423 from Medical Outpatients, 108 from Newborn Follow-up Service and 103 from immunization Clinic. MOI was 35.5%, 23.1% and 9.7% in the above health facilities, respectively. After intervention I, the MOI was 24.5% and 12.2% in Medical Outpatient and Newborn Follow-up Service and none in Immunization Clinic. After intervention-II there was an improvement in immunization of 18.4%, 30.4% and 16.0% in the three health facilities mentioned above. MOI was avoided because the medical officers advised immunization in the above children. The difference in the MOI among Medical Outpatient and Immunization Clinic between baseline, phase-I and phase-II were significant (p < 0.001). It is concluded that MOI can be brought down by creating awareness periodically and that attaching an immunization schedule to the outpatient forms is an effective method of reducing MOI.

Etiological agents of acute poliomyelitis in south India

This study was done to identify the specific etiological agents that cause acute poliomyelitis (APM). All the children newly diagnosed clinically as APM at the Institute of Child Health, Madras, during the period May 1988 to May 1989 were recruited. Stool specimen collection, transportation and identification of viruses by culture were done by standard procedures. The total number of children recruited was 312. Specimens were contaminated/insufficient in 10. Analysis was done for 302 cases. Polio virus type II was identified in 25.5% children, type I in 18.5%, type III in 15.9%, multiple polioviruses in 6.3% and non-polio enteroviruses (NPEV) in 20.2% cases. No virus was identified in 13.6%. Among the APM cases clinically diagnosed, the proportion of NPEV has increased considerably from 5% in 1984 to 20.2% in 1988-89. The age distribution was not significantly different between polio viruses and NPEV. The distribution of polio viruses and NPEV did not differ significantly in relation to immunization status, source of water supply, method of excreta disposal and the clinical types. For surveillance and control/eradication program of poliomyelitis, laboratory confirmation is essential.

Effect of cutting, phosphorus and potassium fertilization on guar plant (Cyamoposis tetragonoloba) in newly reclaimed soil in Egypt

A two year experiment was carried out in newly reclaimed soils (sandy soils) to investigate the effect of cutting and phosphorus and potassium fertilization on the growth, yield, seed mucilage content and seed protein content of guar plant. The results revealed that different cutting treatments significantly decreased the plant weight, seed yield, seed mucilage content and seed protein content. Phosphorus fertilization up to 350 kg super-phosphate (15% P2O5)/feddan* significantly increased plant weight, seed yield, seed mucilage content and seed protein content. Fertilization with 150 kg potassium sulfate (48% K2O)/feddan was quite capable to meet guar plant potassium demands in this kind of soil. Without cutting plants, fertilization with 350 kg super-phosphate and 150 kg potassium sulfate/feddan resulted in the highest seed yield, seed muculage content and seed protein content.

Adrenochrome reaction implicates oxygen radicals in metabolism of cyclosporine A and FK-506 in rat and human liver microsomes

The role of oxygen radicals in the metabolism of cyclosporine A (CyA), FR900506 (FK-506) and carbon tetrachloride (CCl4) catalyzed by the cytochrome P450 system was investigated in vitro in rat and human microsomal preparations. Varying concentrations of CyA, FK-506 and CCl4 (100 microM-1.0 mM) were added to microsomal preparations, and lipid peroxidation was measured by malondialdehyde (MDA) formation as detected by the thiobarbituric acid assay. The effects of oxygen radical scavengers [superoxide dismutase (SOD) and catalase (CAT)] and an antioxidant [glutathione (GLUT)] were tested on various incubations of CyA, FK-506 and CCl4 to assess the role of oxygen radicals in lipid peroxidation. CyA-dependent MDA formation was moderately inhibited by SOD in the rat model and increased by SOD in the human model. In both models, CAT slightly inhibited CyA-dependent MDA formation and GLUT significantly inhibited MDA formation. FK-506-dependent MDA formation, studied only in the rat model, paralleled CyA-induced MDA formation but showed greater inhibition with CAT and less inhibition with SOD or GLUT. In both models, CCl4-dependent MDA formation was significantly inhibited by GLUT and showed no sensitivity to SOD or CAT. In addition, the adrenochrome reaction, which measures the oxidation of epinephrine to adrenochrome, was used to measure the increased oxygen radical-flux resulting from the metabolism of CyA, FK-506 and CCl4. CyA with epinephrine showed the highest oxidative activity, followed by FK-506 and then CCl4, which showed the least formation of adrenochrome. These results indicated a role for oxygen radicals in CyA and FK-506 metabolism.

Influence of maternal nutritional status on mode of delivery and asphyxia neonatorum

To assess the influence of maternal malnutrition on the mode of delivery and asphyxia neonatorum, a cross sectional survey of 615 women in the age group of 20-28 yrs at the time of delivery was done. Women with chronic ailments and complicated pregnancies were excluded. The mothers were then classified into three groups based on Weight Height Product Index (WHPI) namely well nourished (WN), moderately malnourished (MMN) and severely malnourished (SMN). The proportion of asphyxiated babies among the three groups did not differ (P greater than 0.05). Abnormal deliveries like caesarean section were more common among SMN group compared to WN group ((P less than 0.01). No such difference was made out between MMN and WN groups (P greater than 0.05).

Potency of oral polio vaccine stored at distribution centers in Madras

This study was done with the objective to measure, monitor, and document the potency of oral polio vaccine and the storage conditions in the city of Madras for a period of one year from May 88. The Corporation of Madras which takes care of indenting and supplying the vaccine has 87 centers for storage and distribution. We took 12 samples a month from these centers by stratified random sampling technique adopting proportionate sampling. The samples were coded and sent to the laboratory. The investigator noted the storage conditions in a specially designed data card. Results were notified to the managers concerned. 122 samples were tested out of which 28 (23%) showed loss of potency (less than log 10(5.84]. The loss of potency is statistically significant in centers not having dial thermometer and where inappropriate carrier was used for transport of vaccine. It was least in Maternity and Child Health Centers probably due to the orientation of the personnel. The frequency of loss of potency was more in the beginning of the study and decreased as the study progressed. Monitoring of storage conditions and potency of vaccine along with periodic training and reorientation of health personnel are stressed.

Age for measles immunization seroconversion after measles vaccination at 6-8 months of age--a randomized controlled trial

The objective of the study was to compare the effectiveness of measles vaccine by seroconversion in vaccinated children with non-vaccinated children of 6 to 8 months age group in a city slum community so as to study the feasibility of advancing the age of immunization. Live attenuated lyophilized Schwartz strain of measles vaccine was used. Hemagglutination inhibition (HI) antibody was estimated. Seroconversion was defined as either the conversion of negative to positive or a two fold rise in titre. One hundred and thirty two children completed the study. There was no difference in the age, sex and nutritional status between vaccinated and non-vaccinated groups (p greater than 0.7). The seroconversion rate in the vaccinated group was 65% and in the non-vaccinated group was 26%. The age, sex and nutritional status did not significantly affect the seroconversion. Our data suggest that immunization with measles vaccine may be effective as early as 6 months of age. Immunization at 6 months may be needed at least for children in densely populated areas like cities and towns.

Prevalence of placentally transmitted antibodies for measles in infants 3 to 11 months old in an urban slum community

Upto 35% of infants aged between 6 and 11 months are infected with measles in India with its associated high morbidity and mortality. The objective of the study is to know the waning pattern of placentally transmitted antibodies (PTA) for measles so that the age at which children are likely to become susceptible to measles infection could be identified. A cross-sectional serological survey of children aged 3 to 11 months in one of the Integrated Child Development Service (ICDS) area in Madras city slums was done. Venous blood from 376 children was collected and was tested for Hemagglutination Inhibition (HI) antibodies by standard microtitration technique. Titre greater than or equal to 1:8 has been considered as protective. The proportion of children with immune level and the Geometric Mean Titre (GMT), declined to the least by 5 months which denotes that most of the infants become susceptible to measles infection from as early as 5 months of age. There is no significant difference in the waning pattern between different age groups, sex and nutritional status. A community study for effectiveness of measles vaccine at 6-8 months of age is needed to know the feasibility of immunization earlier than 9 months of age.

Osteoarthropathy in hereditary sensory radicular neuropathy. A case report

A young man had hereditary sensory radicular neuropathy with relapsing ulcer of the foot and, in addition to previously known clinical features, osteoarthropathy with hallux valgus, metatarsus primus varus, exostosis, and pes planus.

Interaction of chronic cigarette and ethanol use on myocardium

Chronic cigarette use is common in persons who habitually use other cardioactive agents that have been causally associated with heart disease. This study was undertaken to determine if cigarette use intensifies the abnormalities of myocardial function and composition observed in experimental alcoholism over an 18-month period. Young adult male beagles with tracheostomy were divided into four groups. There were 10 controls (group 1); 9 smoked seven cigarettes per day (group 2); 7 were fed ethanol as 20% of calories (group 3), and 6 received both ethanol and cigarettes (group 4). After a period of 18 months, left ventricular function was assessed under anesthesia. Heart rate, left ventricular end-diastolic pressures, and volumes (indicator dilution) did not differ in the four groups. An index of contractility derived by normalizing peak dP/dt for pre- and afterload was reduced significantly below the level of 2.41 +/- 0.7 cm/s in controls to 1.41 +/- 0.35 in group 2, 1.19 +/- 0.38 in group 3, and 1.28 +/- 0.17 in the ethanol cigarette group (each p less than 0.002). Arterial pressures were moderately elevated above group 1 in all three experimental groups without evidence of left ventricular hypertrophy. In contrast to smoking, which elicited no abnormalities of myocardial cation composition, ethanol reduced myocardial potassium and sodium in group 3 without a gain of water content. In group 4, no further decline of tissue cations was observed. Thus, cigarette use when combined with ethanol over a relatively long period produced no greater myocardial abnormalities than ethanol alone and may not be essential to the genesis of cardiomyopathy in alcoholics.

Cardiac function in alcoholics with cirrhosis: absence of overt cardiomyopathy--myth or fact?

Cardiomyopathy in alcoholics is considered to be associated with a low incidence of hepatic cirrhosis. To evaluate cardiac hemodynamics in alcoholic liver disease, left ventricular function in 37 patients with hepatic cirrhosis (group II) was compared with that in 13 normal subjects (group I) matched for age, sex and cardiac size. These groups were contrasted with group III, comprising 32 alcoholics without cirrhosis who had cardiac symptoms but no cardiomegaly or heart failure. Patients with cirrhosis as a group did not differ from normal subjects (group I) in terms of left ventricular filling pressure and cardiac muscle and pump function (cardiac index). However, subgroup IIA (n = 21) had a stroke index significantly less than normal, while subgroup IIB had a significantly increased stroke index and myocardial cardial contractility with a diminished systemic arterial resistance. Similar hepatic abnormalities were present in both subgroups. In group III, left ventricular end-diastolic and aortic mean pressures were significantly elevated compared with values in normal subjects, while cardiac index and indexes of ventricular contraction and relaxation were abnormal. Further examination of patients with cirrhosis indicated that the responses to volume or pressure increments in terms of the level of stroke work for a given filling pressure were most abnormal in group IIA, approximating those of group III. Thus, although overt cardiomyopathy is infrequent in patients with cirrhosis, asymptomatic myocardial disease may assume clinical importance during volume or pressure overload.

Are pressure-volume relations at end-systole a reflection of left ventricular myocardial contractility?

The pressure-volume relation at end-systole is reportedly altered by changes in contractility. To explore the potential of this ratio in man 185 subjects including 23 normals (Group I) were studied. In 35 patients of Group II (16 with mitral stenosis, 7 with atrial septal defect, and 12 with cor pulmonale) ESP/ESV like an index of contractility measuring force-velocity-length rela tionship (Cy Ix) was insignificantly different from Group I (ESP/ESV and Cy Ix in I = 1.73 ± .31 mmHg/sec, 1.46 ± .09 cm/sec/cm vs 1.44 ± .10, 1.31 ± .05 in II respectively.) With significantly reduced Cy Ix (1.03 ± .04, P<0.00001) ESP/ ESV was likewise reduced (1.16 ± .07, P<0.007) in 108 patients with compen sated LV disease (34 with alcoholic cardiomyopathy, 16 coronary artery dis ease, 30 aortic valve disease, 8 hypertension and 16 with other heart muscle disease.) Like the Cy Ix (0.70 ± .05, P<0.001) ESP/ESV was even lower (0.84 ± .13, P<0.05) in 14 patients with decompensated LV (Group IV). It was insensitive to changes in pressure (angiotensin and volume (dextran). However unlike the Cy Ix it did not vary with acute changes in inotropy (exercise and pacing).

The correlations between ESP/ESV and ejection fraction and contractility index in the entire series though weak, were significant (r = .50 and .20 respectively, each P<0.006). Exclusion of patients with aortic valve disease and hypertension in the analysis tended to improve the relationship between the contractility and end-systolic pressure-volume parameters. In the latter two subgroups neither the ESV nor the ESP/ESV ratio related to the contractil ity index, both parameters however did correlate significantly with the ejection fraction. These results indicate that end-systolic pressure-volume relations provide useful measures of LV performance in man, though not expressing the contractility either in all patients or under all situations.

Development of pulmonary edema related to heparin administration

Bleeding, thrombocytopenia, and osteopenia are recognized as the side effects of heparin administration. We recently noted occurrence of pulmonary edema in a patient with myelofibrosis with myeloid metaplasia being treated with heparin for pulmonary embolism. The hypertensive episodes preceding left ventricular failure were considered related to serotonin released from the immunologically mediated lowering of platelets.

Assessment of left ventricular contractile performance from isovolumic relaxation phase in man

The rate of left ventricular (LV) pressure fall (dP/dtmin) is reportedly altered by contractility and LV stress. To explore the possibility that the ratio of dP/dtmin to dicrotic notch pressure (DTES) measures contractility, 243 subjects including 23 normals (group I) were studied. In 35 patients of group II (16 with mitral stenosis, 7 with atrial septal defect, and 12 with cor pulmonale) DTES, as an index of contractility (Cy Ix) measuring force-velocity-length relationship, was insignificantly different from group I (DTES and Cy Ix in group I = 21.6 +/- 0.6 s-1 and 1.34 +/- 0.04 muscle lengths/s/cm and 18.8 +/- 1.8 s-1 and 1.55 +/- 0.24 muscle lengths/s/cm in group II, respectively). With significantly reduced Cy Ix (1.05 +/- 0.04, p less than 0.01), DTES was likewise reduced (19.0 +/- 0.5, p less than 0.01) in 163 patients with compensated LV disease (47 with alcoholic cardiomyopathy, 24 coronary artery disease, 48 valve disease, 10 hypertensives and 34 with other heart muscle diseases). Like the Cy Ix (0.70 +/- 0.05, p less than 0.001), DTES was even lower (13.3 +/- 0.6, p less than 0.001) in 15 patients with decompensated LV (group IV). Like Cy Ix, this ratio changed significantly with acute changes in inotropy (exercise and pacing), but not with preload (dextran infusion). Basal heart rate, preload and afterload did not influence DTES. Furthermore, DTES correlated significantly in all groups and subgroups with two indices of contractility, VCE (velocity of contractile element) at peak isometric stress, and Cy Ix (r = 0.68 and 0.70, respectively, each p less than 0.001) measured in this study. These results indicate that DTES provides a simple, reliable, and useful measure of the contractile state of LV myocardium in man, independent of preload and afterload.

Isolation of alpha 1-protease inhibitor from human normal and malignant ovarian tissue

Proteolytic enzymes are associated with normal and neoplastic tissues. Therefore protease inhibitors might also be involved in the control of cell function. alpha 1-protease antigen and antitryptic activity have been found in normal and neoplastic human ovarian homogenate. The inhibitor has been localized to ovarian stromal cells or tumor cells by immunoperoxidase staining. The protein was purified to apparent homogeneity as judged by alkaline gel and sodium dodecyl sulfate (SDS) gel electrophoresis. Immunochemical studies revealed antigenic similarity of plasma alpha 1-protease inhibitor by double immunodiffusion and similar mobility on immunoelectrophoresis and two-dimensional electroimmunodiffusion. The molecular weight was similar to that described for plasma alpha 1-protease inhibitor: 60,000 by gel filtration and 53,500 by SDS electrophoresis. Furthermore, the phenotypic pattern as determined by acid starch gel electrophoresis and immunoprecipitation was PiMM, which is the predominant genetic variant in normal plasma alpha 1-protease inhibitor. An inhibitor ws isolated and purified from an ovarian carcinoma that exhibited functional, immunochemical, and physical similarity to the normal ovarian alpha 1-protease inhibitor. alpha 1-protease inhibitor from normal and malignant ovaries competitively inhibited bovine pancreatic trypsin at incubation times of 5 min at 30 degrees C. Inhibition constant (Ki) values were calculated at 0.67 and 0.51 inhibitory units, respectively. The alpha 1-protease inhibitor in malignant cells may be a factor in the control of proliferation in this tissue. Since ovulation is in part a proteolytic event, the alpha 1-protease inhibitor in ovarian cells may play a role in the control of this specialized tissue. Persistance of this protein in malignant ovarian tissue may be a vestige of its differentiated origin.

Cell sodium and the induction of myocardial injury after adrenaline

Accumulation of calcium in cardiac cells during catecholamine induced injury is considered a major pathogenetic factor but its mechanism has not been defined. During initiation of injury in an intact canine model, cell sodium was enhanced fourfold in myocardium after a local infusion of epinephrine via the left anterior descending coronary artery for a 60 min period. Tissue calcium was enhanced and a major role for the Na-Ca carrier system is suggested. Regional myocardial function, blood flow and electrocardiogram responses to toxic levels of the catecholamine have been contrasted with ischaemic injury.