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Biomedical subjects

V Singh

Publications and source records attributed to V Singh.

At least 199 records · Page 11Linked to original sources
PubMed1995

Pattern of hepatitis A and hepatitis B virus markers in cases of acute sporadic hepatitis and in healthy school children from north west India.

The pattern of viral markers in acute sporadic hepatitis in 329 children and those in 334 healthy school children from North West India were studied. Hepatitis A was found to be the commonest infection in sporadic cases (78 per cent). Of these, 86 per cent were under 10 years and 50 per cent less than 5 years of age. Hepatitis B was positive in 8 per cent, non-A non-B in 13 per cent, A as well as B in 1 per cent, and none had Delta virus infection. Viral markers in healthy school children showed anti-HAV IgG positivity in 96 and 85 per cent in those belonging to low and high socio-economic groups, respectively, indicating past infection. HBsAg was positive in 1 per cent of cases. Viral hepatitis is an important public health problem in children and warrants active immunization.

Adolescent↗
PubMed1995

A study of hepatitis delta virus infection in patients with acute and chronic liver disease from northern India.

To assess the prevalence of hepatitis delta virus (H delta V) in northern India, 204 adult patients with acute and chronic liver disease who were positive for hepatitis B virus (HBV) markers were screened for anti-H delta V antibody by enzyme-linked immunosorbent assay (ELISA). Anti-H delta V antibodies were positive in 29 (14.2%) patients. The incidence of H delta V infection was higher (21.4%) in patients with chronic liver disease when compared with those with acute viral hepatitis (10.7%) (P < 0.05). H delta V antibodies were positive in 16.6% of patients with fulminant hepatic failure (FHF) and in 25% of cases with hepatocellular carcinoma. Co-infections were significantly higher in acute hepatitis (80%), while superinfections predominated (66.7%) in chronic liver disease (P < 0.05). Our data show that H delta V is endemic in northern India and should be considered a major health problem.

Acute Disease↗
PubMed1995

Serum 25-hydroxyvitamin D3 is related to physical activity and ethnicity but not obesity in a multicultural workforce.

BACKGROUND: Recent research suggests that body vitamin D levels are decreased in coronary heart disease and diabetes, but it is unclear which cardiovascular risk factors are related to vitamin D status. AIMS: To examine the relation between vitamin D status and major cardiovascular risk factors. METHODS: Serum 25-hydroxyvitamin D3, a marker of recent sun exposure and vitamin D status, was measured in 390 New Zealand residents (95 Pacific Islanders, 74 Maori and 221 others mostly of European descent), who were part of a larger cross-sectional survey of a workforce (n = 5677) aged 40-64 years. RESULTS: Serum 25-hydroxyvitamin D3 levels were significantly lower in Pacific Islanders (mean (SE) = 56 (3) nmol/L; p = 0.0001) and Maoris (68 (3) nmol/L; p = 0.036) compared with Europeans (75 (2) nmol/L) after adjusting for age, sex and time of year. Also adjusting for ethnic group, 25-hydroxyvitamin D3 was higher in people doing vigorous (aerobic) leisure physical activities (71 (2) nmol/L; p = 0.0066) and moderate (non-aerobic) activities (68 (3) nmol/L; p = 0.12) compared with those who were inactive (63 (2) nmol/L). However, 25-hydroxyvitamin D3 was unrelated to body mass index, serum lipids, blood pressure or cigarette smoking. CONCLUSIONS: People with increased skin pigmentation, such as Polynesians, and people who are inactive, have decreased body levels of vitamin D; this might partly explain their increased risk of cardiovascular disease.

Adult↗
PubMed1995

Significance of inflammatory cervical smears.

Two hundred and fifty-seven women attending a Maternal and Child Health Centre (MCH) were examined for different colposcopic and histological patterns associated with cervical inflammation as detected by cytology and for their association with different gynaecological infections. The cytodiagnosis revealed inflammation in 207 women (80.5%) and non-inflammation in 49 (19.5%); one smear was inadequate for evaluation. Fifty-six per cent of the women with inflammation and 20% with non-inflammation had an atypical transformation zone (ATZ), the risk of ATZ being 4.9-fold higher in those with inflammation. Biopsies from 128 women with abnormal colposcopy revealed morphological changes suggestive of human papillomavirus (HPV) in 89 (69.5%) and dysplasia of varying grades in 8 (6.3%). Seventy per cent of histologically diagnosed HPV lesions stained immunohistochemically, whereas 84% reacted with a biotinylated Pan-HPV probe by DNA in situ hybridization (DISH). In addition to HPV, chlamydia (OR 15.6, 95% CI 2.2, 311.6), T. vaginalis (OR 18.4), bacterial vaginosis (OR 24.7, 95% CI 3.5, 492) and herpes simplex virus (OR 4.9, 95% CI 1.4, 20.9) were significantly associated with inflammatory smears. Of 11 dysplasias detected by colposcopy and confirmed by biopsy, 8 (72.7%) had inflammatory cytology in the initial Pap smears. Thus a large proportion of women with inflammatory smears had multiple gynaecological infections and may be at increased risk of developing preneoplastic or neoplastic changes. Furthermore, they risk transmitting the infections to their partners.

Adolescent↗
PubMed1995

Expanded bed adsorption process for protein recovery from whole mammalian cell culture broth.

An expanded bed process for the recovery of soluble protein from whole mammalian cell culture broth by adsorption on specially-designed cation exchange resin is described. A bed of large, dense resin particles in a 5 cm ID column was expanded 2.45 times by the upward flow of three-fold dilute broth. The void space was sufficient to permit cells to flow through the column as the protein was adsorbed. The liquid flow in the column was distributed to minimize back-mixing and create a multiplate adsorption process. During elution, the liquid flow was reversed and the resin bed was packed. In contrast to conventional filtration, the expanded bed process combines clarification, product recovery and concentration into a single-step process. Residence time distribution analysis showed a small degree of axial dispersion and the generation of 22 theoretical plates in the expanded bed (170 ml resin with an unexpanded height of 8.6 cm). Two pilot runs of the process were done with 26 and 36 liters of whole broth at a linear velocity of 135 cm h-1. More than 95% adsorption of the antibody product was achieved without breakthrough in a single pass through the column. Elution recovered 70-85% of the antibody at a concentration as much as 39 times higher than in the broth. The antibody was purified seven-fold in the recovery process mainly because adsorption conditions prevented the binding of 80% of the undesired protein. Because it is less labor-intensive, the expanded bed process is potentially more economical than the filtration recovery process. Although processing time with the expanded bed is considerable, it does not require constant monitoring as does filtration.

Adsorption↗
PubMed1995

Airway response to acid instillation in esophagus in bronchial asthma.

OBJECTIVE: An increased incidence of gastroesophageal reflux has been reported in patients with bronchial asthma. We studied the pulmonary effects of acid instillation in the esophagus. METHODS: Fifteen patients with bronchial asthma and 15 healthy adults in the age group 15-50 years were studied. The control subjects were first screened for bronchial hyperreactivity by a methacholine challenge test. Patients and controls were both subjected to modified Bernstein test. Spirometry was done at baseline and after each instillation of either acid or saline. Respiratory and reflux symptoms were noted after each infusion and antacid administration. RESULTS: Five patients and one control subject had history of reflux symptoms (p < 0.05) and six patients had nocturnal asthma. There was a significant fall in FEV1/FVC after acid infusion patients; this improved significantly after antacid administration. All six patients with nocturnal asthma had respiratory signs or symptoms and had more than 20% fall in FEV1 on acid instillation in the esophagus, while none in the control group developed the same. CONCLUSIONS: Gastroesophageal reflux occurs more frequently in patients with bronchial asthma and acid instillation in the esophagus triggers bronchoconstriction.

Adult↗
PubMed1995

Effect of sucralfate on gastric bicarbonate secretion in patients with duodenal ulcer.

BACKGROUND: Sucralfate is known to protect gastroduodenal mucosa and thereby facilitate healing of peptic ulcer. The mechanism of action of this drug is still not fully known. METHODS: We studied the effect of sucralfate treatment on gastric bicarbonate secretion in 16 patients with duodenal ulcer. RESULTS: Sucralfate administration (3 g daily for 4 weeks) stimulated bicarbonate secretion from 3.1 +/- 1.2 mmol/h to 4.6 +/- 2.0 mmol/h (p < 0.05). Gastric juice volume as well as non-parietal volume secretion also increased significantly after sucralfate therapy (p < 0.05). CONCLUSION: Sucralfate causes stimulation of non-parietal volume-dependent gastric bicarbonate secretion.

Adult↗
PubMed1994

Prooxidant and antioxidant properties of iron-hydroquinone and iron-1,2,4-benzenetriol complex. Implications for benzene toxicity.

Bleomycin-dependent degradation of DNA in bone marrow cells was studied in vitro in the presence of iron or iron polyphenol chelates which are formed during biotransformation of benzene. Iron polyphenol chelates markedly enhanced bleomycin-dependent DNA degradation in comparison to iron alone. About 1.5 and 2.5-fold increase was observed in the presence of iron hydroquinone (HQ) chelate and iron 1,2,4-benzenetriol (BT) chelate, respectively. Endogenous iron chelators such as glutamate, citrate, aspartate, glycine, cysteine, dithiothreitol, AMP, ADP and ATP did not enhance iron-catalysed bleomycin-dependent degradation of DNA. By bleomycin assay, the recovery of iron polyphenol chelate added externally to bone marrow lysate was complete. However, the presence of iron polyphenol chelate resulted in less thiobarbituric acid reactive products from glutamate or brain homogenate than with iron alone. The optical spectra of BT were modified in the presence of ferrous sulphate, revealing a new absorption peak at 259 nm indicating complexation with iron. Thus, the iron polyphenol chelate, on one hand, is a more potent DNA cleaving agent in the presence of bleomycin, and on the other hand, it is a less effective free radical generator as compared to iron alone.

Animals↗
PubMed1994

Effect of amino group modification of ovine luteinizing hormone (oLH) by N-succinimidyl 6-[3-(2-pyridyldithio)propionate]hexanoate, a long chain N-succinimidyl-3-(2-pyridyldithio) propionate (SPDP) on immunological and biological properties: a comparative study with SPDP modified oLH.

The epsilon-NH2 groups of ovine luteinizing hormone has been modified with the long chain N-succinimidyl-3-(2-pyridyl dithiopropionate (LC-SPDP). The LC-SPDP modification primarily occurs in -NH2 groups of the alpha-subunit. Although, the sequential modification of lysine residue in alpha-subunit led to progressive reduction in the receptor binding and immunological properties but the steroidogenic activity was relatively unaffected. The immunoreactivity and receptor binding properties of LC-SPDP modified oLH molecule were more affected comparative to SPDP modified derivatives. This suggested that the increase in hydrophobic carbon chain in LC-SPDP-oLH molecules resulted into the drastic inhibition in the immunological and biological properties. However, the steroidogenic potential of LC-SPDP/or SPDP-oLH derivative was comparable. The present study clearly demonstrate that a single -NH2 group modification with LC-SPDP would generate the site for the conjugation to the toxin/carrier proteins and the resultant oLH-S-S-toxin conjugate would retain significant immunological and biological properties of the hormone molecule.

Amino Acids↗
PubMed1994

Hormonotoxins: the role of positive charge of lysine residue on the immunological, biological and cytotoxic properties of ovine lutropin-S-S-gelonin conjugates.

Since the positive charge on the lysine residues plays an important role in the receptor recognition ability of oLH, the hormonotoxin has been synthesised with the use of 2-iminothiolane HC1 (2IT) and N-Succinimidyl-3-(2-pyridyldithio)-propionate (SPDP). The oLH activated with 2IT (oLH-10) was then mixed with SPDP activated gelonin (gelonin-30) in order to obtain a oLH-S-S-gelonin hormonotoxin. The conjugation mixture containing hormonotoxin was purified by gel-filtration chromatography according to the molecular weight and a complete physico-chemical, immunochemical and biochemical analysis were performed. The linkage occurred through the epsilon-NH2 groups of alpha-subunit of oLH as judged from RP-HPLC analysis. A1:1 (oLH:gelonin) molar ratio was obtained when determined with the use of several techniques. The hormonotoxins retained substantial receptor binding, steroidogenic activity and immunoreactivity. The competitive displacement analysis indicate that the binding occurs via the hormone part leaving the gelonin free which was probed with the gelonin antibodies. The presently described (C150A-02, C160A-02 and C170A-02) hormonotoxins exhibited higher receptor binding and toxicity to the target cells than the hormonotoxins prepared with the use of SPDP only. Therefore it is concluded that higher receptor binding and cytotoxicity may be due to the retention of positive charge on the lysine residues of oLH which was preserved during the conjugation process.

Animals↗
PubMed1994

An elemental correlation study in cancerous and normal breast tissue with successive clinical stages by neutron activation analysis.

Influence of trace elements in body metabolism and their physiological importance in various diseases have motivated their accurate and quantitative determination in biological tissues and fluids. Instrumental Neutron Activation Analysis (INAA) using short and long term irradiation has been employed to determine five minor elements (Cl, K, Na, Mg, P) and 15 trace elements (As, Br, Co, Cr, Cs, Cu, Fe, Hg, Mn, Rb, Sb, Se, Sc, Sr, and Zn) in cancerous and normal breast tissue from 30 patients of four clinical stages. Several elements show enhancement in cancerous breast tissue. Selenium shows maximum enhancement of 94.7% followed by K (81.6%), Sc (66.7%), Cu (58.2%) Na (48.5%), P (44.4%), and Zn (39.2%). Some elements, such as Fe, Cr, and Mn, are depressed by 30.8, 30.1, and 12.8%, respectively. These elements compete for binding sites in the cell, change its enzymatic activity and exert direct or indirect action on the carcinogenic process accelerating the growth of tumors. This is further evidenced by histopathological examination of cancerous cells showing poor cytological differentiation. An attempt has been made to correlate trace element concentrations of Se, Cu, Zn, Rb, Br, Hg, As, Co, Fe, Cr, and Mn and the ratios of Se/Zn, K/P, Cu/Zn, Na/K, and Se/Fe with the clinical stages of cancer. Inhibition of enzymatic activity caused by variation in trace element concentrations results in immunological breakdown of the body system.

Adult↗
PubMed1994

Spectrum of dermatological lesions in renal allograft recipients in a tropical environment.

A total of 157 renal allograft recipients were followed for over 1-23 months for the development of dermatological lesions. The non-infective lesions related to immunosuppressive drugs included cushingoid features in 133 (84.7%), xerosis in 120 (76.4%), striae in 69 (43.9%), hypertrichosis in 65 (21.6%), facial erythema in 42 (26.7%) and friable skin in 34 (21.4%) patients. Of the infective lesions, cutaneous mycoses were the most frequent (82.6%) and included tinea corporis and cruris in 82 (52.2%), tinea versicolor in 21 (13.3%), candidiasis in 7 (4%), onychomycosis in 4 (2%) and cryptococcosis in 2 (1.2%) patients. Viral infections included those due to herpes zoster in 17 (10.8%), herpes simplex in 5 (3.1%) and viral warts in 13 (8.2%) patients. Cutaneous malignancy was seen in 1 patient only.

Adolescent↗
PubMed1994

Differential tropism of EB rotavirus (serotype 3) to small intestine of homologous murine model.

The 4-5 days-old NMRI strain infant mice were orally inoculated with EB rotavirus (serotype 3). The intestinal disaccharidases activity was studied separately in three segments of the small intestine i.e. duodenum, jejunum and ileum on day 1 to 7 post inoculation (p.i.). The severity of EB rotavirus infection correlated with a significant decrease of small intestinal lactase, maltase and sucrase on day 3 p.i. The level of maltase after the initial decline increased in all the three segments of small intestine of infected mice. However, the lactase activity remained suppressed for a relatively longer period in ileum of infected mice than in controls. These enzymes began to approach to normal value by day 5 p.i., but in ileum, lactase activity continued to be severely depressed even on day 7 p.i. Rotavirus was consistently detected in intestinal contents by ELISA on days 1 to 7 p.i. The infected mice showed a significant increase in rotavirus (serotype 3)-specific serum IgG and IgM antibody level during the declining (days 5-7 p.i.) phase of infection. Diarrhoea was noted up to day 6 p.i. The protracted suppression of the lactase activity in ileum in comparison to duodenum and jejunum showed a differential tropism of EB rotavirus (serotype 3) strain to the small intestine of homologous murine model.

Animals↗
PubMed1994

Multiple endocrine neoplasia type-1.

A 38-year-old man with multiple endocrine neoplasia type-1 (Wermer's syndrome) is described. The patient had refractory duodenal ulcers and raised basal acid output (55 mmol/hour) and fasting serum gastrin (1190 pg/ml). Abdominal CT scan revealed mass lesions (gastrinomas) in the head of the pancreas. He also had persistent hypercalcemia, hypophosphatemia, right ureteric calculi, increased urinary calcium and phosphorus and enlarged parathyroids on ultrasound and CT of the neck. Parathormone level was raised, but the pituitary gland was normal on CT scan of the head. The patient was managed initially with histamine H2-blockers, omeprazole and parathyroidectomy; enucleation of the tumor masses in the pancreas was done subsequently.

Adult↗