Search PubMed⌕ Search

Biomedical subjects

N Kumar

Publications and source records attributed to N Kumar.

At least 379 records · Page 21Linked to original sources
PubMed1985

Coagulopathy related to dilution and hypotension during massive transfusion.

A retrospective review of 64 patients receiving more than 10 units of red cell concentrate plus crystalloid within 12 h revealed two consecutive patterns of elevation of the partial thromboplastin time (PTT). The PTT at 3 to 4 h (PTT3-4) correlated with the number of liters of crystalloid (LC) infused over the first 3 h (PTT3-4 = 37 + 7 LC, r = .7643, p less than .001); the PTT thereafter (PTT4+) correlated with the number of hours of closely antecedent hypotension (AH) (PTT4+ = 37 + 21AH, r = .8680, p less than .001). These data indicate a transient dilutional coagulopathy, followed by coagulopathy related to the duration of closely AH. Whether this latter is due to impaired production, disseminated intravascular coagulation, or dilution due to internal shifts of fluids and/or proteins, remains to be clarified. Therapeutic implications of these data are discussed.

Adolescent↗
PubMed1985

Tuberous sclerosis.

Explore the source record for details and available documents.

Child, Preschool↗
PubMed1984

Phase separation of the receptor for immunoglobulin E and its subunits in Triton X-114.

Above its critical micelle concentration, Triton X-114 in solution forms two phases at room temperature: a lower phase containing supramicellar aggregates and an upper phase largely depleted of detergent. This property of the detergent is potentially useful for separating under mild conditions proteins that bind detergent from those that do not (Bordier, C. (1981) J. Biol. Chem. 256, 1604-1607). We studied the distribution of the receptor for immunoglobulin E (IgE) and its subunits in the two phases. IgE and IgE complexed either with intact receptors or with the alpha chains of the receptor alone are principally partitioned into the upper phase, whereas the unliganded receptor as well as the isolated alpha, and especially the beta and gamma chains of the receptor, preferentially partition into the lower detergent phase. Chromatography of IgE and of the subunits of the receptor on a hydrophobic support showed that the beta and gamma chains have a considerably greater hydrophobic surface than the alpha chains or IgE. These results indicate that the distribution of a protein in the two phases of phase-separated Triton X-114 is not an all-or-none effect based upon whether it binds detergent or not. Rather, it reflects the overall balance between the hydrophobic and hydrophilic properties of the protein's surface.

Animals↗
PubMed1984

Target antigens in malaria transmission blocking immunity.

Malaria transmission blocking immunity has been found to operate against two distinct phases of development of malaria parasites in the mosquito midgut: (i) against the extracellular gametes and newly fertilized zygotes shortly after ingestion by a mosquito of parasitized blood and (ii) against the zygotes during their subsequent development into ookinetes. Immunity is antibody-mediated and stage-specific. A set of three proteins, synthesized in the gametocytes, expressed on the surface of the gametes and newly fertilized zygotes and subsequently shed during later transformation of the zygotes, has been identified as the target antigens of anti-gamete fertilization blocking antibodies. A single protein, synthesized and expressed on the zygote surface during its development to ookinetes, has been identified as the target of antibodies which block the development of the fertilized parasites in the mosquito. Immunization of human populations against gamete or zygote antigens, while not directly protecting an immunized individual from inflection, would reduce the transfer of malaria within the population. Such immunity, in addition to reducing the overall rate of malaria transmission, would, if combined with a vaccine against the asexual (disease-causing) stages, reduce the chance of selection of parasites that are resistant to the asexual vaccine by preventing their entry into the mosquito population.

Animals↗
PubMed1984

Biosynthesis of the target antigens of antibodies blocking transmission of Plasmodium falciparum.

We have studied the biosynthesis of three proteins of Mr 260 000, 59 000 and 53 000 previously identified on the surface of extracellular gametes of Plasmodium falciparum as the targets of monoclonal antibodies which block infectivity of P. falciparum to mosquitoes. In cultures of P. falciparum pulse labeled with [35S]methionine we have found that these proteins are synthesized by gametocytes from an early stage in their maturation but are not synthesized by asexual blood stage parasites. The target proteins synthesized by the gametocytes become expressed on the surface of the extracellular gametes but the gametes themselves no longer synthesize these proteins. The 59 000 and 53 000 Mr proteins do not result from processing from the 260 000 Mr protein. The 59 000 and 53 000 Mr protein, but not the 260 000 Mr proteins, were glycosylated by either glucosamine or mannose.

Animals↗
PubMed1984

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↗
PubMed1984

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↗
PubMed1984

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↗
PubMed1984

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↗