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Biomedical subjects

K Kumar

Publications and source records attributed to K Kumar.

At least 73 records · Page 4Linked to original sources

Anomalous course and branches of human coronary arteries.

132 hearts obtained from cadavers were dissected in order to study anomalies in the course and branches of human coronary arteries. Only in 1 heart was a deviation of the circumflex branch of the left coronary artery taking a course inferior to the coronary sulcus observed. The right coronary artery travelled the entire length of the coronary sulcus on the back of the heart and gave both a posterior ventricular and a collateral branch. Circumflex branches of the right and left coronary arteries did not anastomose.

Arteries

Experimental selenium toxicity in guinea pigs: biochemical studies.

Biochemical studies were conducted in experimentally induced selenium toxicity in recently weaned guinea pigs. A significant drop in blood glucose level, in comparison to controls, was observed in animals fed selenium-enriched barley (organic form) as well as those fed ordinary barley mixed with sodium selenite (inorganic form). Estimation of total serum proteins also revealed a significant drop in both these groups. SGOT (EC 2.6.1.1) activity was comparatively lower but no significant alteration was noticed in SGPT (EC 2.6.1.2). The erythrocytic glutathione peroxidase activity was significantly increased in inorganic selenosis followed by that in organic one, in comparison to controls. All these alterations were of mild degree in guinea pigs which were given sodium arsenite (10 ppm) along with sodium selenite (30 ppm) in the feed.

Animals

Glycosylated haemoglobin(HbA1C) and serum protein bound hexose in diabetes mellitus.

Glycosylated haemoglobin (HbA1C) and serum protein bound hexose (SPBH) levels were estimated in 35 healthy control subjects and 35 diabetic subjects. The mean levels of SPBH in control subjects was 161.69 +/- 3.84 mg/dl. The SPBH levels in diabetic subjects were found to be increased (P less than 0.001). It was not influenced by age and sex of the patients, complications, type of diabetes and treatment received. HbA1C levels in control subjects were 5.33 +/- 0.38/dl. The HbA1C levels in diabetic subjects was found to be markedly elevated (11.95 +/- 0.46/dl) and was found to be highly significant (P less than 0.001). The levels were found to be on higher side in juvenile diabetics. A progressive linear correlation was observed between fasting blood sugar levels and concentration of SPBH and glycosylated haemoglobin concentration. A significant correlation was also observed between the levels of glycosylated haemoglobin and SPBH levels (P less than 0.05).

Blood Glucose

Diazinon toxicity: effect on protein and nucleic acid metabolism in the liver of zebrafish, Brachydanio rerio (Cyprinidae).

Four-month old adult siblings of zebrafish were exposed to four concentrations of diazinon for up to 168 h. DNA, RNA, protein and total free amino acid content were monitored in the liver. The DNA, RNA and protein contents were significantly reduced, whereas the amino acid content was significantly enhanced. All these changes showed dose- as well as time-dependent response.

Animals

Cypermethrin toxicity: effect on the carbohydrate metabolism of the Indian catfish, Heteropneustes fossilis.

Toxicity tests revealed that the Indian catfish, Heteropneustes fossilis, is highly sensitive to cypermethrin, a synthetic pyrethroid. The LC50 value decreased with increasing exposure time, revealing a time-dependent action of cypermethrin. Biochemical studies confirmed this, showing that the effects on carbohydrate metabolites also revealed a time-dependent response. The probable reasons for the disturbance in the homeostatic mechanisms of carbohydrate metabolism are discussed.

Animals

Multifocal osteoarticular tuberculosis.

Multifocal osteoarticular tuberculosis is uncommonly reported despite its incidence of 7 to 10% in the Indian population. We describe the clinical features and management of 48 patients seen in the last nine years.

Adolescent

The effect of cardiopulmonary bypass on plasma protein binding of alfentanil.

The effect of cardiopulmonary bypass (CPB) on plasma concentration and protein binding of alfentanil was studied during continuous infusions in five cardiac surgical patients. Patients were given a loading infusion of 10 micrograms.min-1.kg-1 lean body mass (LBM) over 30 s followed by a fixed rate maintenance infusion of 1 microgram.min-1.kg-1 LBM for the duration of surgery. Prior to the commencement of CPB the total plasma alfentanil concentration was 177 micrograms.l-1. This fell to 92 micrograms.l-1 2 min after commencement of CPB and rose to 155 micrograms.l-1 at the end of CPB 2.01 h later. During the same period the unbound fraction of alfentanil rose from 0.16 to 0.35 two min after the start of CPB and fell gradually to 0.22 at the end of CPB. The unbound concentration prior to CPB was 29 micrograms.l-1 and was essentially unchanged by the onset of CPB, being 35 micrograms.l-1 at two min and then 31 micrograms.l-1 at the end of CPB. There was a good correlation between alfentanil bound/unbound concentration ratio and plasma albumin concentration (r = 0.57) and plasma alpha 1-acid glycoprotein concentration (r = 0.80), indicating that the decrease in binding during CPB was due primarily to haemodilution. In assessing the effects of CPB on plasma drug concentrations, it is therefore necessary to monitor unbound as well as total concentrations because the effects on these differ greatly.

Aged

A quantitative morphological assessment of the effect of lidoflazine and deferoxamine therapy on global brain ischaemia.

The effect of the combination of two drugs, i.e. lidoflazine (a calcium antagonist), and deferoxamine (an iron chelator) was evaluated following 15 min global brain ischaemia (GBI) and reperfusion in dogs in a randomized blind study. GBI was produced by complete cardiac arrest of 15 min duration. Histopathological analysis performed on in situ fixed brains 40 h post-resuscitation revealed diffuse microhaemorrhages in the control group. These were noted rarely in the treatment group, the mean value of foci of microhaemorrhages/20 low power fields (LPF) being 5.2 in the treatment group versus 28 in the control group (p less than 0.001). Diffuse coagulative necrosis of neurons (ischaemic cell change) in the cerebral cortex, especially lamina 3, hippocampus, striatum, brain stem and cerebellum was present in all cases. Quantitation of the degree of cellular damage obtained by counting the number of anoxic neurons (in consistent regions of the brain) with the use of an image analysis system, revealed no significant difference between the 2 groups. The mean percentages of the ischaemic neurons in the control group in the various areas studied were: parietal cortex, 22.25; hippocampus, 50.37 and cerebellum (Purkinje cells), 66.75; and in the treatment group 25.3, 55.04 and 70.6 respectively. Thus, the lidoflazine-deferoxamine regimen significantly reduced the incidence of microhaemorrhages in the brain, but it did not have any protective effect against anoxic neuronal injury 40 h post-ischaemia in this experimental model of GBI of 15 min duration.

Animals

Extended blood collection period required to define distribution and elimination kinetics of propofol.

The pharmacokinetics of propofol were investigated following bolus intravenous administration of 2-3 mg kg-1 of drug to eight surgical patients. Apparent elimination half-life, volume of distribution and systemic blood clearance of propofol correlated strongly with the sampling period, which ranged from 8 to 52 h, depending on the time taken for the propofol concentration to reach the detection limit of the assay. In the three patients in whom the sampling period exceeded 42 h, apparent elimination half-life (55.6 h) and apparent volume of distribution (1370 l) greatly exceeded previously published estimates and systemic blood clearance (1020 ml min-1) was much less than previous estimates. This suggests that previous estimates were biased by the relatively short duration of blood collection in those studies (8 to 12 h).

Adult

Effect of maternal alcohol consumption on the lipid composition of CNS in the offspring.

Maternal alcohol consumption at a level that does not affect calorie intake increases cholesterol concentration and content as well as incorporation of labeled glucose into cholesterol in the brain and spinal cord of newborn rat pups. Continued consumption of alcohol during lactation also affects the galactolipid concentration in the brain and spinal cord of pups at 21 days of age, and this increase seems mainly to be due to an increase in content of myelin lipids. Analysis of myelin shows that the concentration of phospholipids also increases in this fraction. The increase in incorporation of labeled glucose into these membrane lipids suggests an increase in the synthesis of these lipids, which prevents fluidization of the membrane by alcohol. That in the brainstem the increase in levels of cholesterol and galactolipids is higher than in other regions and that there is also an increase in content of sphingomyelin, phosphatidylcholine, and phosphatidylethanolamine suggest that the brainstem needs better protection against fluidization.

Animals

Tetanus booster every 5 years: an unnecessary routine?

The various guidelines for the administration of tetanus toxoid and antitetanus immunoglobulin are not only complicated, but also have never been supported by any scientific experimental studies. This study has measured the antibody levels in a random sample of 157 patients presenting to an accident and emergency department. Levels were measured before and after boosting doses. The results show that, in the sample analyzed, even those patients who had their last 'booster' over 10 years ago, had a satisfactory immunoglobulin level. In fact, no patient in the study had a level below the 'protective level'. Bearing in mind the small number of patients in the study, it could be argued that the level of immunity against tetanus in the United Kingdom is likely to be higher than assumed. If this is proven to be correct, then the length of time between booster injections of toxoid can be extended and the use of Human Antitetanus Immunoglobulin can be further restricted.

Adolescent

Neuromuscular pedicle graft for restoration of arytenoid abductor function in dogs with experimentally induced laryngeal hemiplegia.

Left laryngeal hemiplegia was induced by resection of the left recurrent laryngeal nerve in 12 dogs. A neuromuscular pedicle graft formed from the first cervical nerve and sternothyroideus muscle was transplanted after 1 week to the denervated cricoarytenoideus dorsalis muscle in 8 dogs. The remaining 4 dogs served as controls. Left arytenoid abduction was blindly evaluated by laryngoscopy with video photography at time 0, at 1 week, and at 19 weeks in all dogs. At 19 weeks, biopsy specimens of the left cricoarytenoideus dorsalis muscle and the neuromuscular pedicle were taken from 4 of the treatment dogs, and biopsy specimens of the left cricoarytenoideus dorsalis muscle were taken from the 4 control dogs. All biopsy specimens were blindly evaluated by histologic and histochemical examination. At 36 to 44 weeks, the remaining 4 treatment dogs, from which biopsy specimens had not been taken, were reevaluated by use of laryngoscopy with video photography. Complications and difficulties encountered during surgery included hemorrhage in the area of the cricoarytenoideus dorsalis muscle, location of a branch of the first cervical nerve that was long enough to prevent tension at the graft site, orientation of the muscle pedicle in the cricoarytenoideus dorsalis muscle without the use of an operating microscope, and preservation of the terminal portion of the first cervical nerve while forming the neuromuscular pedicle. Results of the arytenoid movement evaluations revealed improvement in arytenoid abductor function in the treatment group, compared with that in the control group at 19 weeks. Arytenoid abduction in the treatment group at this time, however, was still significantly decreased (P less than 0.05), compared with presurgical movement evaluations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals