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Biomedical subjects

B Singh

Publications and source records attributed to B Singh.

At least 451 records · Page 25Linked to original sources
PubMed1995

Reading-induced absence seizures.

Reading epilepsy usually presents with jaw myoclonus and generalized tonic-clonic seizures. We report a 12-year-old girl with absence seizures induced by reading, which were diagnosed by video EEG. An absence seizure with generalized 3-Hz spike-and-wave discharge occurred within 30 seconds of each reading session. Treatment with valproate caused complete seizure control, with therapy successfully discontinued after 2 years.

Child↗
PubMed1995

Effect of preoperative oral fluids on gastric volume and pH in postpartum patients.

The effect of preoperative oral fluids to postpartum patients on the gastric volume and pH was compared with normally fasting postpartum and non-pregnant patients undergoing sterilisation. Forty consecutive postpartum patients and twenty non-pregnant patients scheduled for sterilisation procedure were selected for the study. All patients were fasted overnight. Twenty postpartum patients were randomly allocated to receive 150 ml of plain water two and half hours before surgery (Group 1), while the remaining postpartum patients (Group 2) and non-pregnant patients (Group 3) continued their overnight fast as usual. After induction of anesthesia, gastric volume and pH was measured in all the patients. The mean gastric volume was found to be 21.9 +/- 8.49 ml in Group 1, 22.55 +/- 8.30 ml in Group 2 and 22.65 +/- 8.17 ml in Group 3. The mean pH was found to be 2.21 +/- 0.98 in Group 1, 2.18 +/- 0.88 in Group 2 and 2.12 +/- 1.02 in Group 3. The difference in the volume and pH in all the three groups was statistically insignificant. The difference in the incidence of patients with combined high risk factors of acid aspiration syndrome (gastric fluid volume > 25 ml and pH < 2.5) among the three groups was also insignificant. The authors conclude that ingestion of 150 ml of plain water approximately two and half hours before scheduled time of surgery in overnight fasted postpartum patients does not increase the risk of aspiration syndrome.

Adult↗
PubMed1995

Treatment of lead toxicity in calves.

Thiamine hydrochloride alone or in combination with calcium edetate (Ca-EDTA) was used to treat experimentally-induced lead toxicity in calves. In 12 calves lead toxicity was induced by po administration of 5 mg lead acetate/kg/d until the development of overt signs. The calves were divided into 3 groups: untreated control; thiamine-treated; and thiamine+Ca-EDTA-treated. The use of 25 mg thiamine/kg sc twice daily cured 2/4 calves, whereas 4/4 calves recovered with 25 mg thiamine+110 mg Ca-EDTA/kg iv twice daily. Lead concentrations in blood and tissues were significantly lower and histopathologic lesions were less pronounced in the treated calves. Treatment with thiamine+Ca-EDTA was more effective than the use of thiamine alone.

Administration, Oral↗
PubMed1995

Surface coat of sheep pulmonary intravascular macrophages is reconstituted following brefeldin A-mediated endocytosis.

Pulmonary intravascular macrophages (PIMs) of sheep have a globular coat on their surface which is mobilized by heparin and halothane, and is implicated in the endocytosis of tracer particles and Escherichia coli lipopolysaccharide. Brefeldin A (BFA) was used in vivo to investigate the effects of a pre-Golgi secretion blocker on the integrity of surface coat, and to know whether PIMs produce coat globules. Sheep were injected intravenously with BFA to reach a one time concentration of 2-5 microgram/ml of plasma, and euthanised at 10, 30, 45, 120 and 180 min (n = 1) post-treatment. Lungs were fixed in situ with 2% glutaraldehyde and 2.5% paraformaldehyde for 30 min. Lung tissues were processed for routine ultrastructural examination including treatment with tannic acid (0.1%), and for the acid phosphatase (ACPase) cytochemistry to identify Golgi complex and enzyme-rich endocytic vesicles. Surface coat was endocytosed by the PIMs within 10 min of BFA treatment through long ACPase-negative endocytic channels and degraded in the acid hydrolase-rich lysosomes. Golgi complex membranes were tubulated and were associated with prominent microtubules, centrioles and secretory vesicles. However, trans-Golgi network was not affected by BFA administration. The coat of PIMs was reconstituted within three hours of BFA-induced endocytosis, in concurrence with signs of enhanced biosynthetic activity. It seems that PIMs do not synthesize the globules, and rather sequester from the plasma to organize a surface coat. It is possible that PIMs contribute a membrane anchor or a receptor to facilitate reconstitution of the coat to perform multiple rounds of globule-mediated cell functions.

Animals↗
PubMed1995

Crohn's disease of the esophagus.

A 26-yr-old woman presented with odynophagia, dysphagia, and intermittent bloody stools. Clinical, endoscopic, and microscopic evidence confirmed the diagnosis of severe Crohn's disease of the oropharynx, esophagus, proximal stomach, terminal ileum, and colon.

Adult↗
PubMed1995

Nutritional support in the management of external pancreatic fistulas.

A prospective analysis of 20 patients with external pancreatic fistulas was undertaken over a 5-year period to evaluate the response of pancreatic fistulas to non-operative management. In 90% of patients fistula followed external trauma to the pancreas. There were 18 males and 2 females and the average age was 30.3 years. Fifteen patients were given enteral nutrition alone and 5 received total parenteral nutrition; 2 of these received somatostatin as well. All the fistulas healed spontaneously within 7-80 days, with no deaths. We conclude that if the patient's condition is stable external pancreatic fistulas can be managed safely and effectively by non-operative means. Nutritional support, especially via the enteral route if possible, is beneficial.

Adolescent↗
PubMed1995

Conformational structure of some beta 1-blockers, their partitioning in lipid and the role of parasubstituents.

The conformational structure of beta1-blockers metoprolol, atenolol and practolol has been investigated by PCILO method. The aminoalkanol moiety adopts the same conformation in all these compounds. These beta-antagonists differ only in the conformation adopted by the substituent para to the aminoalkanol moiety. The graphical representation of the B1-antagonists for the final conformation reveals that only in the S-form, three interacting sites, namely, aromatic moiety, the beta-hydroxyl group and the -NH2(+) groups of aminoalkanol moiety are available for interactions with the receptor. The interaction of the aryloxy oxygen of the beta-antagonists with water molecule has also been taken into account. A linear relationship was obtained between log K (the partitioning of the beta-blocker in DMPC and also in octanol/water) and the potencies of these beta1-antagonists. Possibly, the role of para substituent is to act as an anchor by partitioning in the lipid bilayer so that the beta1-antagonist adopts the proper orientation for binding to the receptor.

Adrenergic beta-2 Receptor Antagonists↗
PubMed1995

Nifedipine-induced gingival enlargement around dental implants: a clinical report.

Calcium channel-blocking agents are used extensively for the management of cardiovascular conditions, including angina pectoris, coronary artery spasm, cardiac arrhythmias, and hypertension. Gingival overgrowth around natural teeth has been previously reported in the literature with patients taking calcium channel-blocking agents. This clinical report describes hyperplasia of tissues around titanium dental implants in a patient taking Nifedipine along with the multiphasic approach to treating this medication-induced hyperplasia of the peri-implant tissues.

Animals↗
PubMed1994

Phylogenetic analysis of 70 kD heat shock protein sequences suggests a chimeric origin for the eukaryotic cell nucleus.

BACKGROUND: The evolutionary relationships between archaebacteria, eubacteria and eukaryotic cells are of central importance in biology. The current view is that each of these three groups of organisms constitutes a monophyletic domain, and that eukaryotic cells have evolved fom an archaebacterial ancestor. Recent studies on a number of highly conserved protein sequences do not, however, support this view and raise important questions concerning the evolutionary relationships between all extant organisms, particularly regarding the origin of eukaryotic cells. RESULTS RESULTS: We have used sequences of 70 kD heat shock protein (hsp70)--the most conserved protein found to date in all species--to examine the evolutionary relationship between various species. We have obtained two new archaebacterial hsp70 sequences from the species, Thermoplasma acidophilum and Halobacterium cutirubrum. A global comparison of hsp70 sequences, including our two new sequences, shows that all known archaebacterial homologs share a number of sequence signatures with the Gram-positive group of bacteria that are not found in any other prokaryotic or eukaryotic species. In contrast, the eukaryotic homologs are shown to share a number of unique sequence features with the Gram-negative bacteria that are not present in any archaebacteria. Detailed phylogenetic analyses of hsp70 sequences strongly support a specific evolutionary relationship between archaebacteria and Gram-positive bacteria on the one hand, and Gram-negative bacteria and eukaryotes on the other. The phylogenetic analyses also indicate a polyphyletic branching of archaebacteria within the Gram-positive species. The possibility that the observed relationships are due to horizontal gene transfers can be excluded on the basis of sequence characteristics of different groups of homologs. CONCLUSIONS: Our results do not support the view that archaebacteria constitute a monophyletic domain, but instead suggest a close evolutionary linkage between archaebacteria and Gram-positive bacteria. Furthermore, in contrast to the presently accepted view, eukaryotic hsp70s show a close and specific relationship to those from Gram-negative species. To explain the phylogenies based on different gene sequences, a chimeric model for the origin of the eukaryotic cell nucleus involving fusion between an archaebacterium and a Gram-negative eubacterium is proposed. Several predictions from the chimeric model are discussed.

Amino Acid Sequence↗
PubMed1994

Evaluation of Geriforte, an herbal geriatric tonic, on antioxidant defense system in Wistar rats.

Geriforte, an herbomineral compound prepared from several herbs and minerals, is being used as a restorative tonic to solve the problems of old age in India. Since active oxygen species have been proposed to be involved in the aging process of the brain, alterations in the level of enzymes involved in the defense system against free radicals and other active oxygen species could substantially influence the aging process. Therefore, in the present study, this antistress adaptogenic Ayurvedic preparation has been evaluated for the activities of superoxide dismutase (SOD) and catalase (CAT), key enzymes of the cellular defense system, in the brain of aging Wistar male rats. The present study was carried out on 22-month-old rats. They were given Geriforte powder orally at a dosage of 900 mg/kg body weight once a day for two months. The Geriforte-treated rat brain had significantly high levels of SOD and CAT activities than those recorded in their respective controls. The contents of SOD and CAT in Geriforte-administered brain increased by 24% and 30%, respectively. In the present investigation, free radical damage was assessed by measuring thiobarbituric acid reactive substance (TBARS) in postmitochondrial fractions of brain homogenate. The magnitude of TBARS has been reported to be decreased by 26% in the Geriforte-treated rat brain. In conclusion, it seems logical to suppose that Geriforte, a combination of several plant ingredients and minerals, protects the body against the damaging effects of free radicals by producing large amounts of antioxidant enzymes.

Aging↗