Biomedical subjects
Publications and source records attributed to V Singh.
A 50-year-old woman presented with gastric inlet and outlet obstruction due to achalasia cardia and antral mucosal diaphragm, respectively. The diagnosis was based on typical radiological features, endoscopy and full-thickness histology of biopsy at postmortem.
To know prevalence of rotavirus diarrhea subgroups and serotypes, a prospective study was conducted in rural, periurban and urban communities at Chandigarh. Weekly surveillance for diarrheal episodes was carried out in 110 families each from rural, periurban and urban localities constituting 584 children < 5 years of age from October, 1988 to February, 1991. Stool samples of 218 diarrheal episodes occurring in 115 children were subjected to rotavirus detection by ELISA. Rotavirus positive samples were further analyzed for subgroups and serotypes using specific monoclonal antibodies. Overall prevalence of rotavirus diarrhea was 4.3% (25/584). Rotavirus constituted 11.5% (25/218) of total diarrheal episodes and 22% (25/115) among the children affected with acute diarrhea. Among rural, periurban and urban communities, the overall prevalences of rotavirus diarrhea were 7.3%, 3.2% and 2.3% and episode related prevalences of 31.8%, 7.4% and 5%, respectively (chi 2 test for trend was highly significant from rural to periurban to urban localities). Forty per cent (10/25 of rotavirus positive samples were subgroup I and 60% (15/25) sub-group II. Of the 25 rotavirus strains, 40% (10) were serotype 2, 24% (n = 6) serotype 3 and 36% (n = 9) serotype 4. No definite temporal or seasonal pattern of rotavirus was observed; however, more of rotavirus diarrheal episodes (16%) occurred during winter season. Subgroups and serotypes were observed to cocirculate during the rotavirus episodes. Demonstration of serotypes in our field study imply that the vaccine to be used in our country must be cross protective to have an effective impact on rotavirus infection.(ABSTRACT TRUNCATED AT 250 WORDS)
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We studied the gastric acid and bicarbonate secretion rates in 12 patients with duodenal ulcer and 6 age matched healthy controls. Measurements of gastric juice volume (nonparietal and parietal), acidity and osmolality were done. The ulcer patients secreted more acid, parietal and nonparietal fluid than controls under basal conditions and after subcutaneous pentagastrin injection (6 micrograms/kg body weight). However, the gastric bicarbonate secretion was similar in the duodenal ulcer patients and controls, both under basal state as well as after pentagastrin stimulation. The gastric acidity was similar in ulcer patients and control subjects under both the states (49.3 +2- 4.5 vs 50.0 +/- 6.0 mmol/l basally, 85.2 +/- 8.9 vs 63.4 +/- 6.6 mmol/l after pentagastrin injection respectively). Thus, gastric bicarbonate secretion was similar, whereas parietal and nonparietal volume secretions were increased in patients with duodenal ulcer as compared to controls.
Administration of benzene (ip, 0.5 ml/kg body wt or sc, 1 ml/kg body wt) consecutively for 10 days to male and female rats resulted in decrease in antioxidant potentials in serum. Serum uric acid and albumin showed significant decrease in all groups exposed to benzene. alpha-Tocopherol levels did not exhibit significant change in any of the groups when compared to control. Increase in liver lipid peroxidation and decrease in content of free sulphydryl group were observed in rats exposed to benzene. Serum ferroxidase activity, total iron content (TIC) and total iron binding capacity (TIBC) in female rats exposed to benzene showed significant decrease in ferroxidase activity without any change in TIC or TIBC when compared to control. The decrease in antioxidant potentials observed may be due to oxidation reactions exhibited by benzene metabolites, particularly, hydroquinone and 1, 2, 4-benzenetriol, resulting in oxidative stress in treated rats.
AIMS: To study the presentation of severe vitamin D deficiency in Auckland and to determine if appropriate therapy was given. METHODS: Retrospective review of records of patients with very low plasma 25 hydroxyvitamin D concentrations (< or = 12.5 nmol/L or 5 micrograms/L). RESULTS: Fifty cases were identified over a two year period. 28 subjects had recognised risk factors for vitamin D deficiency (such as gastrointestinal disease or greatly reduced food intake). The majority of the other 22 subjects were elderly residents of rest homes or private hospitals. Low body weight and reduced mobility were common features of both groups. Increased plasma alkaline phosphatase activity and hypocalcaemia were the most frequent biochemical findings. Appropriate treatment with high dose calciferol had been given to only 28% of the subjects. CONCLUSIONS: Severe vitamin D deficiency does occur in Auckland despite its low latitude. Low body weight, reduced mobility and lack of sun exposure are particular risk factors. Appropriate therapy is cheap, safe and effective but many patients with severe vitamin D deficiency are being managed suboptimally.
In order to assess the levels of fluoride ingestion through intake of tea, studies were conducted with four different brands of tea leaves commonly available in the Indian market. Four most prevalent methods for the preparation of tea with various contact times (2,4,6,8 and 10 min) of tea leaves with water show that: (a) leaching of fluoride is least in case of leaf tea as compared to powdered tea (F levels increasing with decreasing grain size); (b) leaching of fluoride reaches a maximum after a contact of about 6 min; (c) there is no difference between levels of fluoride with or without addition of milk in the English style where tea leaves are not boiled, while for the Indian style, addition of milk and subsequent boiling resulted in reduction of fluoride levels and (d) ingestion of fluoride per cup of tea ranged from 1.55 mg/l to 3.21 mg/l amounting to an intake per day per person of fluoride between 0.3 to 1.9 mg.
BACKGROUND: Infection with human papillomavirus (HPV) is considered to be the principal causal agent in the development of squamous cell carcinoma of the uterine cervix. Although adenocarcinoma of the cervix originates adjacent to the squamous epithelial neoplastic lesions, the etiopathogenesis of adenocarcinoma is not yet clearly understood. Recent studies have raised more controversy, rather than answering the question of whether specific HPV infection also plays a role in the development of adenocarcinoma of the cervix. Molecular DNA hybridization techniques were used to detect HPV types prevalent in both adenocarcinoma and squamous cell carcinoma of the uterine cervix, which is the most common cancer in Indian women. METHODS: Histologically confirmed, formaldehyde-fixed, paraffin-embedded tissue sections from 12 cases of adenocarcinoma and 30 cases of squamous cell carcinoma of the uterine cervix were analyzed retrospectively for the presence of HPV DNA types 6b, 11, 16, and 18 by both Southern blot hybridization and in situ hybridization. RESULTS: Of 12 adenocarcinomas, 5 (41.67%) tumors were positive for HPV DNA: All five cases were positive for HPV 16, and two (16.6%) of these were hybridized again to the HPV 18-specific DNA probe. All tumors were negative for HPV 6b and 11. In addition, no biopsy specimens were positive after hybridization with a mixed probe of HPV 31, 33, 35, 39, and 45. These results were compared to those obtained for 30 squamous cell carcinomas of the cervix. Although 20 (66%) were exclusively positive for HPV 16 and 6 (20%), more tumors were of HPV 16 related types as detected under nonstringent conditions of hybridization, only one (3%) was positive for HPV 18. The results of in situ hybridization were found to be in good agreement with those of Southern blotting. CONCLUSIONS: HPV 16 is the type present almost exclusively in squamous cell carcinoma of Indian women. A higher frequency of HPV 16 in adenocarcinoma of Indian women, in contrast to HPV 18, as reported from other regions, may be attributed to geographic variation rather than to histologic differences only, and both HPV 16 and 18 may be present in adenocarcinoma of the uterine cervix.
Since, linking of ovine luteinizing hormone (oLH) to ribosome inactivating protein gelonin (in oLH-gelonin conjugate) occur via the alpha-subunit, alpha oLH, an attempt has been made to develop a 'universal' hormonotoxin for selective targeting to specific cells in the gonads. Four different molar ratios of oLH and N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) were used to activate the epsilon amino (phi-NH2) groups of alpha oLH. The alpha oLH-SPDP derivatives recombine to native beta subunit of oLH (beta oLH) and the purified recombinants retained substantial receptor binding, steroidogenic activity and immunoreactivity to native oLH. The disulfide linked alpha oLH-S-S-gelonin conjugates prepared by SPDP method were purified by gel filtration chromatography and analysed by reverse-phase high performance liquid chromatography (RP-HPLC). In order to obtain specificity and bioeffectivity, the alpha oLH-S-S-gelonin conjugates were allowed to recombine to native beta oLH and the recombination mixture was further purified by gel-filtration chromatography. The RP-HPLC analysis of these recombinants indicated that alpha oLH-S-S-gelonin did not recombine to beta oLH. The failure of recombination may be due to the reasons. (i) The site of epsilon-NH2 activation by SPDP may be different in the alpha oLH than the native oLH. (ii) The activation site may be in close proximity to the annealing site which facilitates the recombination of beta-subunit but failed to reassociate to alpha oLH-S-S-gelonin conjugate.(ABSTRACT TRUNCATED AT 250 WORDS)
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Peptide M, an 18-amino acid fragment from position 303 to position 320 of retinal S-antigen, produces experimental autoimmune uveitis (EAU), similar to that produced by native S-antigen, in several vertebrate species including nonhuman primates. It was observed that 12 of the 39 (30.7%) patients with uveitis, 1 of the 29 (3.4%) patients with systemic connective tissue disorders (CTD) without eye involvement, 2 of the 7 (5.8%) patients of CTD with uveitis, 1 of the 17 (5.8%) patients with diabetic retinopathy, and none of the 19 normal healthy controls showed a significant lymphoproliferative response to peptide M (stimulation index of 3 or more). Yeast histone H3 peptide gave a positive response in 1 (2.5%), 2 (6.8%), 1 (14.2%), 2 (11.7%), and 2 (10.5%) individuals, respectively, in the different groups studied. In a few cases a positive response to yeast histone H3 peptide was observed without significant stimulation to peptide M. These findings indicate that peptide M could also be an immunogenic epitope of S-antigen in humans and be aetiopathologically related to uveitis in a subset of patients with this disease. However, unlike experimental animals, the responses to peptide M and yeast histone H3 were nonconcordant, necessitating further studies.
Two main nematode parasites, Haemonchus longistipes and Trichostrongylus colubriformis, have been reported to cause morbidity and mortality in camels. Although goats are usually reared with camels in the combined animal husbandry system prevailing in Northern India, these parasites have not been reported in goats. Therefore, it was planned to conduct an experimental cross-transmission study of H. longistipes and T. colubriformis isolated from camels and transferred to young goats. Twelve healthy kids (5-6 months) were divided into three groups of four each. Groups I and II were infected orally with third stage infective larvae of H. longistipes and T. colubriformis cultured in the laboratory from faecal isolates from camels, at the rate of 50,000 and 100,000 larvae, respectively; group III comprised uninfected healthy controls. Daily clinical and faecal examinations were made. Body weights and blood haematological indices were measured at weekly intervals. The infection became established in both infected groups, and the animals started passing ova 17 days postinfection. Egg counts varied from 275.00 +/- 248.74 to 6150 +/- 2830.63 eggs g-1. Animals were killed 28 days postinfection. On postmortem examination mature as well as immature worms were recovered from the abomasum and intestine with typical postmortem changes seen in both the groups. Clinical manifestations were weakness and loss of body weight but no diarrhoea. There was a marked fall in haemoglobin and packed cell volume, indicating anaemia in both infected groups.
Life tables of birth intervals and median birth intervals in two Indian states, Uttar Pradesh and Kerala, were computed for several subgroups of the study population. Multivariate hazards modelling technique was used to examine the net effect of each of the variables studied. The results show a substantial effect of socioeconomic variables in child-spacing after controlling for the major intermediate variables.
We evaluated nutritional risk factors for cataract in 660 subjects enrolled in the Baltimore Longitudinal Study on Aging. As a part of a regular cycle of visits, nuclear and cortical lens photographs were taken over a 2-year period. Measurements of plasma antioxidants (beta-carotene, ascorbic acid, and alpha-tocopherol) were obtained in this cohort as part of the study protocol up to 4 years before lens photographs were taken. We found that plasma beta-carotene and ascorbic acid levels were not associated with risk of nuclear or cortical lens opacities. Higher levels of plasma alpha-tocopherol, however, were associated with a reduced risk of nuclear opacity [odds ratio (OR) for highest quartile vs lowest quartile = 0.52, 95% confidence interval (CI) = 0.27-0.98; OR for middle two quartiles vs lowest quartile = 0.55, 95% CI = 0.30-0.98], after adjusting for age, sex, and history of diabetes. Middle levels of alpha-tocopherol were associated with a reduced risk of cortical opacity (OR = 0.57, 95% CI = 0.32-1.02), but no such association was observed for high levels of alpha-tocopherol. We constructed an index of overall antioxidant status, which indicated that higher levels of plasma antioxidants were not associated with risk of nuclear or cortical opacities.
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OBJECTIVE: To review the literature on the efficacy and safety of antifungal agents for prophylaxis of fungal infections in populations of immunocompromised hosts (key words: hematology-oncology, surgical, solid organ transplant, HIV infection), and to develop guidelines and recommendations regarding safe and effective drug regimens for antifungal prophylaxis in this patient population. DATA EXTRACTION: Comprehensive review of clinical trials of antifungal prophylaxis published in the English literature, with an emphasis on controlled trials, and discussion of key clinical trials illustrating efficacy and safety of agents for antifungal prophylaxis in immunocompromised patients. RESULTS: Much of the clinical data evaluating the efficacy and safety of antifungal prophylaxis has been generated in cancer patients. The choice of antifungal agent for prophylaxis in this population remains controversial. However, azole compounds such as clotrimazole, ketoconazole and fluconazole appear to be more effective and better tolerated than nystatin suspension. Although ketoconazole has been shown to reduce fungal colonization in surgical patients, current data do not support the routine use of antifungal prophylaxis in this population. In renal transplant recipients, clotrimazole troches have been shown to be more effective than placebo or nystatin suspension. Selective bowel decontamination with nonabsorbable antibiotics and nystatin may be useful in reducing Candida colonization in liver transplant patients but no definitive recommendations may be made at this time regarding optimal antifungal prophylaxis in these patients. In patients with advanced HIV disease or history of prior fungal disease prophylaxis for oropharyngeal candidiasis is indicated, although the agent of choice remains controversial. Fluconazole is the drug of choice for prevention of relapse of cryptococcal meningitis in patients with AIDS. Finally, only limited data exist assessing the relationship between local colonization and systemic fungal infection. Adverse effects associated with antifungal prophylaxis, generally limited to nausea and vomiting and transient elevations in hepatic transaminases, occur with similar frequency among available oral or topical agents. However, the incidence of nausea and vomiting with resultant poor patient tolerance and compliance is usually higher with nystatin. CONCLUSIONS: Based on available data from controlled clinical trials, azole agents are currently the most effective and best-tolerated drugs for antifungal prophylaxis in immunocompromised hosts. Choice of one agent in this group over another may be dictated by cost. As new antifungal treatments are released onto the market, these drugs should be compared with existing agents in controlled clinical trials. Future studies should be designed to evaluate the relationship between local colonization and disseminated infection.
Infant mice (NMRI strain) showed the inhibition of hepatic extramedullary haemopoiesis by oral inoculation of a 100 ID50 dose of EB rotavirus and nucleoprotein of SA-11 rotavirus (serotype 3). The extramedullary haemopoiesis was observed by oral inoculation of surface protein VP7 of SA-11 rotavirus and in control (placebo administered) mice.
To fully understand immune competence in subjects with precancerous and cancerous lesions of the uterine cervix, various markers of T and B cells in peripheral blood were evaluated. The cellular measures were the absolute numbers of CD2, CD3, CD22, CD25, CD4, CD8 and CD4/CD8 T cell ratio and serologic measures were the levels of cellular products ie interleukin-2 (IL-2) and soluble interleukin-2 receptors (SIL2-R). Eighty-five subjects were analysed, and diagnosed histologically as CIN (n = 33) and invasive cancer (n = 22). Thirty women with normal Pap test results served as controls. Results on cellular markers showed a significant decrease in peripheral blood lymphocyte counts in patients with higher grades of cervical lesions as compared to controls (CIN III P < 0.05 and invasive cancer P < 0.001). Similar trends were observed for CD22 cell counts (P < 0.001). A consistent decrease was observed for CD2 positive T lymphocytes in patients with higher grade cervical lesions only. In addition, a decrease in CD4-T cells with a relative increase in CD8 and CD25 cell count was observed in these groups of patients, leading to a considerable reduction in CD4/CD8 T-cell ratio. Results obtained on soluble cellular products revealed that serum levels of IL-2 and SIL2-R in patient groups were significantly higher than controls (P < 0.001). Preliminary findings indicated a host-vested cellular impairment, evidenced by immune deficit and immune-stimulation, in women with pre-cancer and cancerous lesions of the cervix.