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Biomedical subjects

B Singh

Publications and source records attributed to B Singh.

At least 577 records · Page 32Linked to original sources
PubMed1992

v-mos proteins encoded by myeloproliferative sarcoma virus and its ts159 mutant.

The myeloproliferative sarcoma virus (MPSV) v-mos protein was predicted to be identical in size to p39c-mos because of an observed one-base deletion in the seventh codon of the env-mos open reading frame, which would allow translation to initiate at the methionine equivalent to codon 32 of the env-mos gene. On the basis of published results, p39c-mos is known to have greatly reduced in vitro protein kinase activity compared with p37env-mos encoded by Moloney murine sarcoma virus. Unexpectedly, the relative activity of the MPSV v-mos protein kinase was comparable to that of p37env-mos. Consistent with this finding, the size of MPSV v-mos protein was found to be similar to the size of p37env-mos. Moreover, the pattern and sizes of phosphorylated bands produced by autophosphorylation of the MPSV v-mos protein were similar to those of p37env-mos. These results were confirmed by in vitro transcription-translation of the MPSV v-mos gene. Resequencing portions of the MPSV mos gene failed to show the deletion within codon 7. Except for the codon 262 deletion, other mutations characteristic of MPSV and temperature-sensitive MPSV v-mos genes were confirmed. A glycine-to-arginine mutation at residue 338 of the MPSV env-mos sequence, previously shown to cause thermosensitivity of the mutant virus (termed ts159) transforming function, yielded a v-mos protein that had significantly reduced protein kinase activity in vitro. These findings indicate that MPSV, like other Moloney murine sarcoma virus strains, also encodes a functional env-mos protein.

Amino Acid Sequence↗
PubMed1992

Cardiovascular complications of parenteral nutrition.

During a 3 year period, 1987-1989, we encountered three major complications associated with parenteral nutrition leading to congestive cardiac failure--acute beriberi, right atrial and superior vena caval thrombosis, and fungal endocarditis. Unrecognized, these are invariably fatal. Persistent vomiting from intestinal obstruction led to the development of thiamine deficiency in the patient with beriberi. Recurrent catheter tip sepsis probably accounted for thrombosis and endocarditis in the second and third cases, respectively. These conditions are preventable with careful attention to nutritional replenishment and aseptic technique. In patients with catheter-related sepsis early, repeated blood culture is of diagnostic value. Patients with Staphylococcus aureus catheter-associated bacteraemia require at least 4 weeks of appropriate antibiotic therapy. Recurrent sepsis, especially when associated with pulmonary embolic phenomena, is an indication for echocardiography.

Adult↗
PubMed1992

Use of warm local anaesthetic solution for caudal blocks.

A double-blind study was undertaken to investigate the effect of prewarmed local anaesthetic solution on the latency of onset of caudal blocks. Forty-four (ASA I-II) patients were allocated into two equal groups. In Group A, the local anaesthetic solutions were injected at room temperature (25 degrees C), while in Group B, they were injected at 37 degrees C. All the caudal blocks were performed using 20 ml of lignocaine 1.5% with adrenaline 1:200,000. The speed of onset of perianal analgesia was found to be significantly faster (39%) with the prewarmed local anaesthetic solution (P < 0.05). No adverse effects were observed.

Adult↗
PubMed1992

A high-risk community study of paternal alcohol consumption and adolescents' psychosocial characteristics.

A prospective community study looked at drinking behavior and biopsychosocial correlates of adolescents (in years 9 and 10 and again in years 11 and 12 at 23 high schools) and their parents. Heavy drinkers were compared to nil/low drinkers. Sons were more likely to drink heavily if fathers drank heavily and mothers who drank heavily were more likely to cohabit with heavy drinkers. Differences in psychological characteristics and home environment were defined in regard to heavy drinking fathers and drinking sons. Difficulty in settling disagreements and reduced time spent with family were the main correlates associated with drinking by both boys who did not necessarily have a heavy drinking father and those who did.

Adolescent↗
PubMed1992

Prevention of recurrence of IDDM in islet-transplanted diabetic NOD mice by adjuvant immunotherapy.

Insulin-dependent diabetes mellitus (IDDM) involves the destruction of the insulin-producing cells in the islets of Langerhans. One possible cure is by transplanting the islet cells; however, transplanted islets, even between identical twins, are subject to autoimmune destruction by the disease process, resulting in diabetes recurrence. We recently reported that complete Freund's adjuvant (CFA), an immunomodulating agent, prevented development of autoimmune diabetes in the NOD mouse. In this study, we evaluated adjuvant therapy in prevention of autoimmune destruction and rejection of transplanted islets in diabetic NOD mice. After transplantation, untreated syngeneic islet recipients (n = 16) initially became normoglycemic and then hyperglycemic, with a median survival time (MST) of the graft of 17 days. When CFA was administered at the time of transplantation, 11 of 13 CFA-treated syngeneic islet recipients remained normoglycemic long term (greater than 100 days) with an MST greater than 107 days. Ten of 11 mice maintained indefinite normoglycemia until the conclusion of follow-up (101 to 172 days). When adjuvant therapy was used in conjunction with allogeneic islet transplantation, graft survival was not extended, with MST being similar to the untreated allogeneic islet recipients (12 [n = 5] and 13 [n = 5] days, respectively). The extended acceptance of second syngeneic islet grafts by CFA-treated mice indicates that the persistent autoimmunity against the transplanted islets can be reversed in the diabetic NOD mice after CFA treatment.

Animals↗
PubMed1992

Symptomatic response to antipsychotics differs between recent onset and recurrent chronic schizophrenic patients.

The symptomatic response to standard antipsychotic treatment was assessed over the first 4 weeks of hospitalisation in 39 patients with DSM-III schizophrenia, active phase, using the Brief Psychiatric Rating Scale (BPRS). While highly significant improvement was noted overall, 36% of patients either did not improve or worsened. Furthermore there was no diminution in the withdrawal-retardation factor of the BPRS. Patients experiencing their first admission to hospital, all with recent-onset illness, were then compared with patients who presented with a recurrence and had illness of at least 3 years duration. Despite similarities in overall response, withdrawal-retardation scores did not diminish in recent-onset patients, in contrast to multiple admissions who demonstrated significant improvement. These findings suggest greater responsiveness of negative symptoms to treatment in patients with longstanding illness, and possibly a poorer prognosis in first admission patients with deficit manifestations.

Acute Disease↗
PubMed1992

Evidence for interaction between v-Mos and a p34cdc2 isoform, p35cdk.

The c-mos gene product (c-Mos) encodes a serine/threonine kinase required for activation of pre-MPF (maturation-promoting factor) to MPF in oocytes undergoing meiosis and also for stabilization of MPF leading to metaphase arrest in unfertilized eggs. In order to determine whether the v-mos gene product (v-Mos) causes neoplastic transformation via interaction with cell cycle control elements, we have searched for proteins that interact with v-Mos. Extracts of NIH3T3 cells transformed by v-Mos encoded by Moloney murine sarcoma virus (Mo-MuSV) were examined by gel filtration, by immunoprecipitation with antibodies to a conserved region of p34cdc2, and by binding to beads that contain cross-linked p13suc1, a protein known to bind p34cdc2. Gel filtration detected a 500-kDa complex that contained v-Mos and a p34cdc2 isoform, termed p35cdk. The 500-kDa macromolecular complex also exhibited histone H1 phosphorylation activity, consistent with the presence of a cdc2 isoform. The identity of p35cdk is based on its recognition by anti-cdc2 PSTAIR but not by anti-cdc2 C-terminal antibodies, which detect authentic p34cdc2. Structures containing v-Mos and p35cdk were also detected by experiments involving co-immunoprecipitation of v-Mos with anti-cdc2 PSTAIR antibodies. Furthermore, both v-Mos and the p35cdk co-precipitated with p13suc1-Sepharose beads. Our findings raise the possibility of a v-Mos-p35cdk regulatory interaction in cells transformed by Mo-MuSV.

3T3 Cells↗
PubMed1992

Oak (Quercus incana) leaf poisoning in cattle.

Oak poisoning occurred in crossbred cattle due to eating immature tender oak (Quercus incana) leaves. Mortality was 70%. The animals exhibited anorexia, severe constipation and brisket edema. The feces were hard, pelleted and coated with blood and mucous. Significant reductions in blood hemoglobin and mean corpuscular hemoglobin, and significant elevations in serum bilirubin were observed. Serum urea nitrogen and creatinine were greatly increased. There was bilirubinuria, proteinuria, hypoproteinemia and hypocalcemia, and greatly increased activities of serum aspartate aminotransferase, lactate dehydrogenase and alkaline phosphatase. The levels of tannins and condensed tannins were 97.7 mg tannic acid equivalent and 5.8 mg catechin equivalent/g of dry leaves. There was extensive nephro- and hepatotoxicity in the affected cattle due to hydrolysable tannins and simple phenols in the oak leaves.

Anemia, Hemolytic↗
PubMed1992

The physical interactions between p37env-mos and tubulin structures.

The c-mos protein has been reported to be complexed with tubulin and to co-localize with microtubules in unfertilized Xenopus eggs as well as in NIH3T3 cells transformed by the Xenopus c-mos gene. We performed experiments to determine whether the viral mos protein, p37v-mos, also associates with tubulin. Both mouse c-mos and v-mos proteins synthesized in vitro co-polymerized with tubulin. Upon incubation at 37 degrees C, essentially all of the mos protein (both viral and cellular) co-polymerized with tubulin, while more than 50% of the tubulin remained in the depolymerized state. The mos-tubulin interaction was specific, as indicated by the insolubility of the v-mos protein following a second cycle of temperature-dependent depolymerization/polymerization. Beta-tubulin was shown to co-precipitate with p37v-mos and to be phosphorylated by the mos kinase in vitro. Although both v-mos and c-mos proteins co-polymerize with tubulin, p37v-mos behaved differently from p39c-mos on gel filtration columns under conditions that favor disassembly of microtubules. Like Xenopus c-mos, the bulk of the mouse c-mos protein synthesized in vitro appeared in structures that fractionate at about 500 kDa. In contrast to c-mos, the majority of the v-mos protein, either isolated from stably transformed NIH3T3 cells or synthesized in vitro, eluted in the 100 kDa fraction, co-fractionating with tubulin dimers. Therefore, the v-mos protein appears to have a higher affinity for unpolymerized tubulin than c-mos, under conditions that favor disassembly of microtubules.

3T3 Cells↗
PubMed1992

Oxygen consumption and carbon dioxide elimination after release of unilateral lower limb pneumatic tourniquets.

Oxygen consumption (VO2), carbon dioxide elimination (VCO2), and respiratory exchange ratio (RQ) were continuously measured in 15 male and 15 female adults during knee surgery, with the leg exsanguinated by an inflatable tourniquet around the thigh. Arterial blood was also intermittently sampled for blood gas analysis, electrolytes, and lactate content before and after tourniquet deflation. There was a significant increase in VO2 and VCO2 after tourniquet deflation, which was more pronounced in the male (aged 29.5 +/- 14.8 yr, mean +/- SD) than the female (aged 56.9 +/- 15.6 yr) patients, both in terms of maximal increase (P less than 0.001) and percent of increase from values before deflation (P less than 0.001 and P = 0.01). The body weights and tourniquet inflation times were not significantly different between the male and female patients. Excess VO2 (O2 debt) and excess VCO2 over 12 min after deflation of the tourniquet were also significantly higher for male (593.5 +/- 222.9 mL and 714.9 +/- 463.8 mL, respectively) than for female patients (302 +/- 73.3 mL and 196 +/- 162.22 mL, respectively; P less than 0.01). There was no correlation between the duration of tourniquet inflation time and peak increase in VO2, peak increase in VCO2, and O2 debt over 12 min after deflation of the tourniquet; however, tourniquet time was weakly correlated with excess VCO2 over 12 min after tourniquet deflation (r = 0.55, P = 0.002). There was a significant decrease in pHa (P less than 0.001) from release of PaCO2 and lactate after tourniquet deflation. Plasma potassium levels also increased significantly after tourniquet release (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Prospective randomized comparison of sodium tetradecyl sulfate and polidocanol as variceal sclerosing agents.

A prospective randomized controlled study was designed to evaluate differences in efficacy and complication rate between the two most commonly used sclerosing agents, sodium tetradecyl sulfate (STD) and polidocanol. Of 52 patients with esophageal variceal bleeding, 26 were randomized to receive sclerotherapy with 1.5% STD and 26 to receive 1% polidocanol at weekly intervals. Eradication of varices was achieved in 88% patients each of the STD and polidocanol group. There was no significant difference between patients injected with STD and polidocanol with regard to re-bleeding (27% vs. 15%) and mortality (11.5% in both). The use of STD, in contrast to polidocanol, was associated with a higher incidence of complications in terms of severe retrosternal pain (27% vs. 4%), deep ulceration (53% vs. 23%), dysphagia (88% vs. 46%), and stricture formation (27% vs. 8%). It was concluded that these two agents were similar in efficacy. However, polidocanol was superior due to a lower incidence of complications.

Adolescent↗