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Biomedical subjects

K Kumar

Publications and source records attributed to K Kumar.

At least 163 records · Page 9Linked to original sources
PubMed1990

Giant axonal neuropathy: clinical, electrophysiologic, and neuropathologic features in two siblings.

Giant axonal neuropathy is a progressive central-peripheral axonopathy characterized by distention of axons by aggregated neurofilaments. We report two female siblings with giant axonal neuropathy. Both patients developed symptoms of a chronic progressive polyneuropathy at age 3 years. Clinical evidence of central nervous system involvement was present in both cases. Autopsy neuropathologic examination of the older sibling at the age of 11 years revealed numerous giant axons, Rosenthal fibers, and gliosis throughout the brain and spinal cord and typical giant axons in the peripheral nerves. Electrophysiologic studies in the younger sibling indicated brain stem dysfunction, and her sural nerve biopsy revealed enlarged axons packed with neurofilaments. These patients illustrate that neurologic deficits of giant axonal neuropathy result from widespread lesions in the central, as well as peripheral (including autonomic), nervous systems. This occurrence of giant axonal neuropathy in two siblings supports a genetic origin of this disease. This is the first report of autopsy findings in giant axonal neuropathy in an affected sibling.

Axons↗
PubMed1990

Efficacy of prolonged therapy with stibogluconate in post kala-azar dermal leishmaniasis.

Fifty three (30 male and 23 female), previously untreated, patients with post kala-azar dermal leishmaniasis (PKDL) were treated with sodium stibogluconate, at the dose of 20 mg/kg/bw/d/im/(with a maximum of 8.5 ml) for 120 days (or more, if necessary). All the patients were followed up for 12 months. The patients were assessed after 40 days and thereafter at an interval of 20 days. The mean age of onset was 24 yr, maximum number of patients developed the disease within 3 yr of apparent cure of kala-azar. Maximum number of patients sought treatment within 5 yr of the onset of PKDL. The disease affected the face (98%), trunk (83%), upper limb (72%), lower limb (40%), genetalia (6%), and mucus membrane of the tongue 40%. The lesions observed were nodules (19%), papules (30%), and hypopigmented (45%) and reddish macules (7%). The parasites could be demonstrated in the nodules (100%), papules (69%) and macules (59%). The response to treatment started in 72 per cent of patients in the first 20 days and in 40 days in all patients. All the nodules and papules disappeared in 120 days, and the macules within 200 days. The side effects of treatment noted were changes in S T and T in electrocardiogram (7%), arthralgia (11%), allergic rash (7%), swelling at the site of injection (5%), neuralgia (4%) and metalic taste (6%). The S T and T changes reverted to normal when the drug was discontinued for 20 days. Arthralgia improved with indomethacin. The higher dosages and longer course of treatment were well tolerated and resulted in a cure in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Standardisation of multiple-choice questionnaire for evaluating medical officers' training in psychiatry.

This study reports the standardisation of a multiple choice questionnaire (MCQ) for evaluating the training of primary care physicians in psychiatry. An item pool of 104 multiple-choice questions of the 'single best response' type was written. This item pool along with an 'MCQ assessment sheet' was mailed to 90 psychiatrists with a request to evaluate the questionnaire. Twenty five psychiatrists responded to the enquiry, of which 22 gave their detailed comments regarding the MCQ. Based on the responses that were received, 14 items were discarded, 77 items were modified and 13 items accepted without any modification. The final pool of 90 items was split into two comparable sets, one for pre-training assessment and the other for post-training assessment. The questionnaire was administered to a group of 32 medical officers and was found to be sensitive in detecting gains in knowledge following training.

Educational Measurement↗
PubMed1989

Cell-cycle radiation response: role of intracellular factors.

We have been studying variations of radiosensitivity and endogenous cellular factors during the course of progression through the human and hamster cell cycle. After exposure to low-LET radiations, the most radiosensitive cell stages are mitosis and the G1/S interface. The increased activity of a specific antioxidant enzyme such as superoxide dismutase in G1-phase, and the variations of endogenous thiols during cell division are thought to be intracellular factors of importance to the radiation survival response. These factors may contribute to modifying the age-dependent yield of lesions or more likely, to the efficiency of the repair processes. These molecular factors have been implicated in our cellular measurements of the larger values for the radiobiological oxygen effect late in the cycle compared to earlier cell ages. Low-LET radiation also delays progression through S phase which may allow more time for repair and hence contribute to radioresistance in late-S-phase. The cytoplasmic and intranuclear milieu of the cell appears to have less significant effects on lesions produced by high-LET radiation compared to those made by low-LET radiation. High-LET radiation fails to slow progression through S phase, and there is much less repair of lesions evident at all cell ages; however, high-LET particles cause a more profound block in G2 phase than that observed after low-LET radiation. Hazards posed by the interaction of damage from sequential doses of radiations of different qualities have been evaluated and are shown to lead to a cell-cycle-dependent enhancement of radiobiological effects. A summary comparison of various cell-cycle-dependent endpoints measured with low- or high-LET radiations is given and includes a discussion of the possible additional effects introduced by microgravity.

Cell Cycle↗
PubMed1989

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↗
PubMed1989

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↗
PubMed1989

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

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↗