HLA associations with Hashimoto's thyroiditis

There is disagreement over the HLA-DR associations of Hashimoto's (goitrous) thyroiditis. We have studied 86 English Caucasian patients with this condition whose DR types were determined by restriction fragment polymorphism analysis. HLA-DR3 was significantly more frequent in these patients than in 100 controls (chi 2 = 7.09; P less than 0.01). The relative risk was 2.23 and aetiological fraction 0.29. HLA-DPB and DQB alleles were analysed in a proportion of these subjects by enzymatic DNA amplification and oligonucleotide probing. The only significant finding was an excess of HLA-DQw2 (in linkage disequilibrium with DR3) in the Hashimoto group (chi 2 = 7.43, P less than 0.007). These results do not support a difference between goitrous and atrophic thyroiditis based on respective associations with HLA-DR5 and DR3, but confirm a recent study in which HLA-DR3 was associated with Hashimoto's thyroiditis. However, it is possible that genes telomeric to DR3 may be involved in determining which type of thyroiditis a patient with autoimmune hypothyroidism develops.

Constrictive pericarditis masquerading as Budd-Chiari syndrome

Budd-Chiari syndrome (BCS) and constrictive pericarditis (CP) share many common clinical features. Over the last year we encountered three patients in whom CP clinically mimicked BCS. Two of the three did not even have raised jugular venous pressure. One patient with severe jaundice and hepatic coma ultimately died. Liver biopsy features were not discriminating. The final diagnosis of CP was established by echocardiography, chest computed tomography (CT), or cardiac catheterization. We conclude that in all patients with apparent BCS and atypical features, a noninvasive test like echocardiography or chest CT should be done to rule out treatable illness like CP before embarking on such invasive procedures as liver biopsy for diagnosis.

Mosquito fauna of certain areas of deltaic West Bengal--a preliminary report

Survey of mosquito fauna in certain areas of deltaic Bengal was conducted between September 1989 to February 1990. Anopheles vagus predominated in Canning study area and Anopheles hyrcanus in Budge Budge. Comparatively low densities of Anopheles annularis were recorded from Canning (6.05% of the total anophelines) and Budge Budge (7.36% of the total anophelines), respectively. C. vishnui, C. pseudovishnui and C. tritaeniorhynchus were collected from both Canning and Budge Budge study areas. C. pseudovishnui predominated in Canning and C. vishnui in Budge Budge. Amongst the three species of C. vishnui complex, C. triateniorhynchus ranked third in order of preponderance at both the study areas.

HLA antigens in Asian Indian patients with Graves' disease

A study of 57 Asian Indian patients with Graves' disease revealed a significant increase in the frequency of HLA-DQW2 (61.4%) as compared to the control population (22.6%) giving a relative risk of 5.4. Less prominent but statistically significant increase in the frequency of HLA-A10 (29.8% patients as opposed to 10.5% controls) and HLA-B8 (28.1% patients as opposed to 8.7% controls) was also observed. Further, patients carrying the phenotypes HLA-A10 and HLA-B8 were more prone to develop the disease at a younger age. Two HLA haplotypes, namely A10-B8 and B8-DR3, were found in significant linkage disequilibrium in our patients with Graves' disease. Patients carrying these haplotypes also had a tendency to develop the disease at an earlier age.

Role of cockroaches in allergy to house dust in Calcutta, India

Prick skin tests on 200 patients with a history of sensitivity to dust were done against house dust, cockroach, D. pteronyssinus, and D. farinae antigenic extracts. The frequency of positive reaction was 35% to cockroach, 59% to house dust, 84.7% to D. farinae, and 54% to D. pteronyssinus. Distinctively different prevalence of the three antigens, cockroach, house dust, and mites suggest that cockroach antigen is a specific antigen independent from house dust and mite antigens.

Clinical significance of IgE in bronchial asthma

Total mean serum IgE levels of 63 patients (aged 16-49 years) suffering from bronchial asthma and 64 control subjects (aged 19-40 years) were estimated by RIA method. Mean serum IgE level of patients and control subjects was 1132 +/- 643 units/ml and 43 +/- 26 units/ml respectively. The difference between the two values was statistically significant (p less than 0.001). Four per cent of the patients had serum IgE levels within normal limits. No significant correlation was found between mean serum IgE level of the patients and the duration of the disease. Differences in mean serum IgE level of male and female patients and control subjects was not statistically significant. The mean serum IgE level of patients in the age group of 21-40 years was highest (F = 1.33, p less than 0.05). Significantly elevated levels of serum IgE were observed in patients with both personal and family history of atopic disease in comparison to patients with only personal or family history only (p less than 0.05). As such the estimated raised level of IgE was significant in view of the severity of atopic asthma.

Density of Culex vishnui and appearance of JE antibody in sentinel chicks and wild birds in relation to Japanese encephalitis cases

In the District of Burdwan, a rural area of West Bengal State, India, Japanese encephalitis (JE) virus is endemic. In one village a longitudinal survey was conducted in order to find out whether associations could be established between the density of the vector mosquito Culex vishnui in two types of resting places, the incidence of infections in sentinel chicks exposed at monthly intervals, the prevalence of antibodies in wild birds and the occurrence of clinical infections in the human population. The experiment lasted from August 1981 till August 1982. Meteorologically a summer season (March-June), a rainy season (July-October) and a winter season (November-February) are distinguished. In the sentinel chicks infections were observed in all three seasons; in wild birds antibodies were prevalent throughout the year; these observations suggest perennial transmission of the virus in its maintenance cycle. Human infections were observed periodically with, in August 1982, a pronounced peak; this may point to fluctuations in the level of circulation of the virus in its maintenance cycle and spillover to the human population at times of peak circulation. The peaks may be related to the influx of young non-immune birds and newborn mammals into the animal population in summer. Further studies, including virus isolation attempts from mosquitoes and nestling birds, are required to prove this hypothesis.

Thrombin receptors define responsiveness of cholesterol-modified platelets

The microviscosity of human platelet membranes was changed by incubating platelets with liposomes containing various ratios of cholesterol and lecithin. Binding of 125I-thrombin to the modified platelets was measured together with platelet aggregation and secretion. In cholesterol-normal platelets (mole ratio of cholesterol to phospholipid (C:PL) = 0.553; eta = 2.40 poise), weighted nonlinear least squares curve fitting indicated that a model involving two classes of sites was adequate to describe the binding isotherm (K1 = 8.3 X 10(8) M-1; R1 = 150 sites/platelet; K2 = 6.4 X 10(6) M-1; R2 = 16,000 sites/platelet). In cholesterol-enriched platelets (C:PL = 0.857; eta = 3.05 poise), the apparent affinities for the two classes of sites decreased to 55 and 53%, respectively, while the binding capacities increased to 170 and 160%, respectively. In contrast, in the cholesterol-depleted platelets (C:PL = 0.435; eta = 2.03 poise), the affinities increased to 220 and 180%, respectively, while the binding capacities decreased to 53 and 46%, respectively. In cholesterol-enriched, cholesterol-normal, and cholesterol-depleted platelets, the thrombin concentrations required for half-maximal aggregation were 0.17, 0.35, and 0.52 nM, respectively, while the values for half-maximal secretion of [14C]serotonin were 0.17, 0.40, and 0.55 nM, respectively. Plots of receptor occupancy versus biological response showed that maximum response in cholesterol-enriched, cholesterol-normal, and cholesterol-depleted platelets occurred with occupancy of 30, 50, and 70% of the high affinity sites, respectively. In all three treatment groups, occupancy of 40-50 high affinity sites results in 50% aggregation. These results show that (i) modification of platelet membrane microviscosity results in changes in the number and affinity of both high and low affinity thrombin receptors, (ii) the change in receptor number rather than affinity is the determinant for platelet responsiveness, and (iii) the changes in membrane microviscosity do not appear to alter the coupling between occupied receptor and subsequent bioresponse.

Fly borne Vibrio parahaemolyticus in Calcutta

V. parahaemolyticus has been detected from flies in all months of the year in Calcutta. The mean percentage of isolation is: housefly 14.1, blue bottle fly 18.5, external washing 10.1, viscera 22.6, flies of sweet shops 9.7 and those from fish market 22.7. Flies revealed higher (4.4%) isolation of Kanagawa postive V. parahaemolyticus strains than those of water and fish specimens (0.8%) studied previously. Strains negative to Kanagawa test but simulating enteropathogenic serotypes are recorded in 8.0% isolates. Possibility of fly borne contamination from the sources like human faeces, sewage and fish is discussed.