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Biomedical subjects

N Kumar

Publications and source records attributed to N Kumar.

At least 433 records · Page 24Linked to original sources

Long term course and outcome of the Agra cases in the International Pilot Study of Schizophrenia.

The course and outcome at a 13-14-year follow-up of the Agra cases in the International Pilot Study of Schizophrenia (IPSS) was observed by two methods: i) through a mailed questionnaire to assess the key respondents own perception of their state, ii) by a thorough clinical examination and assessment using standard instruments. The results of these two methods were compared and no significant difference found. Based on the second method it was found that 46% of schizophrenics and 43% of manic-depressives had one or two episodes during the first 5 years after inclusion and none in the subsequent period of 8 to 9 years (up to the present follow-up). The results indicate that the illness loses its intensity over a period of years. Mortality among schizophrenics was higher than the expected rate in a general population. The suicide rate was similar to that reported in other studies.

Adolescent↗

A surface protein expressed during the transformation of zygotes of Plasmodium gallinaceum is a target of transmission-blocking antibodies.

Antibodies against gametes of malarial parasites (Plasmodium spp.) have previously been shown to block infectivity of the parasites to mosquitoes by preventing fertilization of the parasites in the insect midgut. These antibodies did not have any effect on the development of fertilized parasites. We now report that a surface protein of Mr 26,000 synthesized by zygotes of P. gallinaceum is the target of antibodies which block infectivity of the fertilized parasites to mosquitoes. Identification of this target antigen offers a new stage of the parasite against which a malaria transmission-blocking vaccine could be developed.

Aedes↗

Controlled therapeutic trial to determine the optimum dose of antacids in duodenal ulcer.

Antacids are widely used in the management of duodenal ulcer but the optimum dose of antacid required for ulcer healing has not been determined. We therefore studied 107 patients with endoscopically diagnosed duodenal ulcer who were allotted at random to one of the following treatment groups; placebo (group P) and antacid (groups A, B and C). A liquid antacid (Aludrox MH, Wyeth) with neutralising capacity of 2.3 mmol HCl/ml was administered in graded doses of 7.5 ml (Group A), 15 ml (Group B), and 30 ml (Group C), one hour and three hours after each meal, six times a day for four weeks. Patients in group P received 15 ml liquid placebo in a similar fashion. Complete symptomatic relief was obtained in 33% of patients in the placebo group, 54% in antacid group A, 89% in group B, and 92% in group C. Endoscopic assessment at the end of four weeks of treatment gave an ulcer healing rate of 29% in the placebo group, 46% in group A (103.5 mmol antacid/day), 85% in group B (207 mmol/day), and 88% in group C (414 mmol/day). There was no significant difference in the healing rates and pain relief between placebo and antacid group A, while both groups B and C had significantly higher ulcer healing rates and pain relief compared with placebo (p less than 0.001) and antacid group A (p less than 0.01). Drug related unwanted effects were recorded only in group C - 28% of patients suffered from diarrhoea. It is concluded that the optimum antacid requirements for the treatment of duodenal ulcer is 90 ml (acid neutralising capacity, 207 mmol HCl) per day.

Adult↗

Anterior radial keratotomy experience in 600 cases of myopia.

Surgical results of anterior radial keratotomy in 1,200 eyes are presented. Of the eyes, 55% had an unaided visual acuity of 6/9 or better six months after surgery. An average of 1.90 D of myopia was corrected in these cases. It takes six weeks for the refraction to stabilize and to know the final success of surgery. There was no statistically significant influence of age or sex or preoperative refractive error on the amount of surgically induced change in refraction. The extent of myopia corrected is directly proportional to the change induced in the radius of curvature. The operative and postoperative complications were minimal and did not endanger vision.

Adolescent↗

Aggregation and calcium-induced fusion of phosphatidylcholine vesicle-tubulin complexes.

Insertion of tubulin into the bilayer of dipalmitoyl phosphatidylcholine vesicles at the phase transition results in the formation of stable vesicle-tubulin complexes (Klausner, R. D., Kumar, N., Weinstein, J. N., Blumenthal, R., and Flavin, M. (1981) J. Biol. Chem. 256, 5879-5885). These complexes aggregated when maintained below phase transition for 10-20 min. Addition of millimolar concentrations of Ca2+, Mn2+, Zn2+, and Co2+, but not Mg2+, caused the vesicle-tubulin complexes to fuse into larger structures as shown by (a) electron microscopy, (b) increased trapped volume, and (c) changes ion resonance energy transfer between two fluorescent lipid probes incorporated into the same vesicle. There was no loss of internal aqueous contents from the vesicle-tubulin complexes during Ca2+-induced fusion. Anti-tubulin drugs had no effect on the aggregation or fusion, and vesicle-bound tubulin did not associate with microtubules when tubulin was assembled in vitro. Trypsin-treated vesicle-tubulin complexes were incapable of supporting Ca2+-induced fusion. This system provides a model for Ca2+-induced and protein-mediated nonleaky fusion of uncharged lipid bilayers.

Animals↗

Gel filtration in 6 M guanidine hydrochloride of the alpha-subunit (and its fragments) of the receptor for immunoglobulin E.

The mol. wts of the alpha-chain of the receptor for immunoglobulin E and several of its enzyme-cleaved fragments have been evaluated by gel filtration on Sepharose 6B in 6 M guanidine HCl. The mol. wt of alpha-chains treated with endoglycosidase was 30% less than that of untreated alpha-chains. alpha-Chains digested with papain eluted in a single peak with a mol. wt approximately one-half of that of undigested alpha-chains. The results support the proposal that papain cleaves alpha-chains into two fragments of similar size [Goetze et al. (1981) Biochemistry 20, 6341-6349].

Chromatography, Gel↗

Modulation of some parameters of assembly of microtubules in vitro by tyrosinolation of tubulin.

Using tyrosinolated and detyrosinolated tubulins, we have compared several parameters of microtubule assembly in vitro. Rates and extents of polymerization were the same under all conditions, but microtubules assembled from detyrosinolated tubulin in the presence of crude microtubule-associated proteins (MAPs) or subsaturating MAP-2 contained a smaller proportion of the MAPs. Preliminary results indicate that this may be a function of the phosphorylation state of MAP-2. Tyrosinolated tubulin assembled into relatively shorter microtubules in the presence of saturating MAP-2. When assembly was induced with substoichiometric concentrations of taxol, in place of MAPs, the rate and extent of assembly were about twice as great with tyrosinolated tubulin.

Animals↗

"Makings of a dacoit".

A study of the dacoits of the Chambal River valley was undertaken to determine what special circumstances exist to make them to take to dacoity, or whether these outlaws had a psychopathic disposition. The study sample consisted of 50 dacoits, compared with 50 aggressive criminals and 50 normals (non-criminals) from the same region. Among the most important factors contributing to their choosing this particular criminal career were: insecure childhood, enemity, psychopathic or wayward tendencies, belonging to a family of outlaws, rejection by society, extremely discordant family conditions, and the influence of operating dacoits.

Antisocial Personality Disorder↗