Tumor necrosis factor-alpha levels in patients with HIV with wasting in South Asia.

Tumor necrosis factor (TNF)-alpha is thought to play an important role in wasting; but TNF-alpha levels have not been consistently found to be high in AIDS wasting. We conducted this study to determine any correlation between TNF-alpha levels and wasting in HIV-positive patients in a developing country. TNF-alpha levels were measured in four groups of patients: Group 1, HIV/AIDS with wasting (n = 25); group 2, HIV/AIDS without wasting (n = 47); group 3, HIV-negative patients with tuberculosis with wasting (n = 25); and group 4, healthy controls (n = 25). Wasting was defined as a body bass index (BMI)

Correlations of C-reactive protein levels with anthropometric profile, percentage of body fat and lipids in healthy adolescents and young adults in urban North India.

OBJECTIVE: To investigate the relationships of sub-clinical inflammation and regional and generalized obesity and lipids in adolescent and young adult Asian Indians in north India. METHODS: We determined serum levels of C-reactive protein (CRP), a marker for sub-clinical inflammation, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (W-HR), four skinfolds (biceps, triceps, subscapular and suprailiac), percentage of body fat (% BF) and lipid profile in 377 healthy adolescents and young adults (331 males and 46 females, age range: 14-25 years). RESULTS: Overweight subjects (BMI>85th percentile), and subjects with high values (>85th percentile) of WC and triceps skinfold thickness had significantly higher median CRP levels (P=0.04, P=0.001 and P=0.007, respectively) as compared with subjects with lower values of the variables. Elevated levels of CRP (>2.1 mg/l) were observed in 21.8% of the overweight subjects and 24.5% of the subjects with high (>85th percentile) % BF. After adjusting for age and gender, the odds ratios (95% CI) for elevated levels of CRP were 2.3 (1.1-4.7, P=0.02) for overweight subjects, 2.6 (1.2-5.4, P=0.01) for subjects with high % BF, and 3.7 (1.7-7.9, P=0.001) for subjects with high triceps skinfold thickness. Levels of CRP correlated significantly with % BF (r=0.13, P=0.009), W-HR (r=0.11, P=0.02), biceps skinfolds (r=0.13, P=0.01) and triceps skinfolds (r=0.13, P=0.01) for males only. CONCLUSIONS: The observations of substantial prevalence of elevated CRP levels in adolescents and young adults having increased generalized and abdominal adiposity may be important for the development of metabolic syndrome and atherosclerosis in Asian Indian adults.

A simplified ELISA for anti-receptor antibodies in myasthenia gravis.

Nicotinic acetylcholine receptor (nAchR) from triton extracts of muscle adsorbed specifically and optimally to microtitration plates at pH 7.4 rather than at pH 9.6. An ELISA for anti-receptor antibodies in myasthenia gravis based on direct adsorption of the receptor at pH 7.4 is described (direct assay). The direct assay compares very well in sensitivity and specificity with an indirect assay, in which the receptor was attached through alpha-bungarotoxin adsorbed on the solid phase (correlation coefficient 0.94).

alpha-Bungarotoxin aggregates on radioiodination with chloramine-T but not with iodogen.

The presence of polymer(s) of radioiodinated bungarotoxin (Bgt) in preparations iodinated with chloramine-T or with iodogen, was investigated by chromatography on Sephadex-G50. In addition to a monomeric peak (P2), chloramine-T preparations showed a high content of polymeric forms (16-43%) eluting in the void volume (P1), present only to the extent of 1-3% in iodogen preparations. In purified [125I]Bgt prepared by the iodogen method, the content of P1 increased on treatment with chloramine-T, in the absence of radioiodine. The nonspecific binding of [125I]Bgt to DE-81 filter discs was high in the case of chloramine-T preparations and proportional to the content of P1 in each batch. Purified P1 (polymer) but not P2 (monomer) showed a concentration-dependent high degree of binding to DE-81 discs.

Efficacy of antibodies generated by Pr-beta-hCG-TT to terminate pregnancy in baboons: its reversibility and rescue by medroxyprogesterone acetate.

Antibodies produced by the vaccine Pr-beta-hCG-TT in monkeys were effective in terminating pregnancy in baboons on passive administration. The animals returned to cyclicity soon after the onset of vaginal bleeding. Fertility was regained. Globulins from non-immunized control monkeys in amounts, volume and injection schedule similar to those employed for passive termination did not intercept pregnancy. The abortifacient action of anti-CG antibodies could be counteracted by administration of medroxyprogesterone acetate.

An ELISA for quantitation of tetanus toxin.

A sandwich ELISA for quantitation of tetanus toxin was devised using commercially available horse antitetanus antiserum and its HRP-conjugate. With commercial toxoid as a standard the assay had a lower sensitivity of 100 ng/ml and was linear up to 100 micrograms/ml. In terms of Lf equivalents the ELISA assay was linear from 0.02 to 20 Lf/ml. The Lf activity in 20 preparations of tetanus toxin as determined by ELISA was comparable to the activity measured by conventional flocculation tests (r = 0.987).

Nonradioactive polynucleotide gene probe assay for the detection of three virulence toxin genes in diarrhoeal stools.

The present study describes a nonisotopic DNA-DNA hybridization assay for the detection of enterotoxigenic Escherichia coli (ETEC) in which the probes were labelled with the hapten molecule digoxigenin and after hybridization, DNA hybrids were detected by antidigoxigenin alkaline phosphatase conjugate. A blinded study carried out on a battery of enterotoxigenic and nonenterotoxigenic Esch. coli by dig-probe hybridization assay were compared with the results of a radiolabelled toxin gene probe hybridization assay (performed earlier). The three digoxigenin labelled probes gave a 100 per cent specificity and sensitivities of 95.45, 100 and 100 per cent for LT, STh and STp respectively. These results were comparable to those with the radioactive probes.

Sero-epidemiology of hepatitis E virus (HEV) in urban and rural children of North India.

OBJECTIVE: To estimate the prevalence of anti-HEV IgG and IgM antibodies to ORF3 peptide of Hepatitis E virus genome in an age stratified urban and rural population of children. DESIGN: Cross sectional survey. SETTING: Pediatric out-patient clinics in a tertiary hospital and a rural dispensary. METHODS: Study subjects between 6 months and 10 years with minor, non-hepatic illnesses were recruited for the study from March to December 1996. Baseline demographic details, drinking water source, sewage disposal methods, reasons for attending the hospital, histories of parenteral exposure in the past 12 months and acute hepatitis in the subjects and the family in the previous six months were obtained. Serum anti-HEV IgG antibodies were screened in all subjects, and in those who were positive, anti-HEV IgM antibodies were assayed as an indicator of recent infection. Serum aminotransferase (ALT) was estimated in those who were anti-HEV IgM antibody positive. RESULT: Out of 2160 subjects recruited, 2070 samples could be screened for anti-HEV IgG antibodies. In the urban population (n = 1065) anti-HEV IgG antibodies were detected in 306 subjects (28.7%; 95% CI 26.0-31.6) and of these 131 (42.8%; 95%CI 37.2-48.6) were anti-HEV IgM antibody positive. Amongst 1005 rural children, anti-HEV IgG antibodies were present in 239 (23.8%; 95% CI 21.1-26.4) and IgM antibodies in 113 (47.3%; 95% CI 40.9-53.7) children. The antibodies were present since the first year of age till 10 years of age and, increased with advancing age. Serum transaminases were raised in 7.5% (9/120) and 5.5% (5/88) of subjects with anti-HEV IgM antibodies in urban and rural centers respectively. Overall the seroprevalence of IgG antibodies against HEV were significantly more in urban as compared to that in rural subjects (p = 0.011). However, proportion of children with anti-HEV IgG carrying IgM antibodies was similar in the two study groups (p = 0.298). A model for estimating expected prevalence of anti-HEV IgG antibodies was developed. The observed antibody prevalence in both urban and rural subjects at each age interval after 48 months was less as compared to the expected levels and this gap increased with advancing age categories. It appeared that there was a decay of HEV antibodies with time. CONCLUSIONS: Children are susceptible to HEV infection since early infancy. The probability of exposure to HEV during childhood was higher in urban than rural population. Seropositivity to HEV antibodies increased by over 2 times beyond 4 years of age as compared to younger age. Anti-HEV IgG antibodies appear to wean off with increasing age.