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N Kumar

Publications and source records attributed to N Kumar.

At least 307 records · Page 17Linked to original sources
PubMed1990

The effect of adrenalectomy and dexamethasone on interleukin-1 alpha induced responses in RIF-1 tumours.

In the present studies the effect of bilateral adrenalectomy on the pathophysiologic responses to recombinant human interleukin-1 alpha (rHIL-1 alpha) was determined in RIF-1 tumour models. Acute vascular injury and haemorrhagic responses were quantitated by the intra-tumour accumulation of 59Fe radiolabelled erythrocytes. In vivo clonogenic tumour cell kill was determined by an excision assay. A single, intraperitoneal rHIL-1 alpha treatment (6.25 x 10(7) D10 units kg-1, 25 micrograms kg-1) resulted in acute tumour haemorrhage and approximately 55% clonogenic tumour cell kill (24 h). Bilateral adrenalectomy, 24 h before rHIL-1 alpha, significantly increased haemorrhagic responses, but haemodynamic toxicity was severe. This toxicity could be ameliorated by giving dexamethasone (5 mg kg-1) before or up to 3 h after rHIL-1 alpha. The effect of dexamethasone on rHIL-1 alpha induced tumour responses in adrenalectomised mice was sequence dependent. Given before rHIL-1 alpha, dexamethasone inhibited tumour haemorrhage. When dexamethasone was given up to 3 h after rHIL-1 alpha, tumour haemorrhage was directly related to sequence interval. Although adrenalectomy and dexamethasone alone had little effect on RIF-1 tumours, adrenalectomy increased rHIL-1 alpha mediated clonogenic tumour cell kill. The surviving fraction 24 h after rHIL-1 alpha (6.25 x 10(7) D10 units kg-1, 25 micrograms kg-1) and dexamethasone (5 mg kg-1, 2 h after rHIL-1 alpha) was 1.3 +/- 0.4%. The surviving fraction after this combination in intact mice (36.7 +/- 1.4%) was approximately 30-fold higher than that seen in adrenalectomised mice. The results indicate that adrenal responses secondary to rHIL-1 alpha treatment exert a negative feedback on rHIL-1 alpha mediated responses in solid tumours.

Adrenalectomy↗
PubMed1990

Modulation of gap junction transcript and protein expression during pregnancy in the rat.

The expression of three different gap junction transcripts, alpha 1 (Cx43), beta 1 (Cx32), and beta 2 (Cx26) was examined in several organs during pregnancy in the rat. In all of the organs that were examined--uterus, ovary, heart, and liver--there was a strong correlation between levels of gap junction mRNA and gap junction antigens that were detected at different stages of pregnancy. A striking change in alpha 1 transcript levels (a 5.5-fold increase) was detected in the uterine myometrium on the day before parturition. This elevation of the alpha 1 transcript is thought to be associated with the formation of gap junctions that are required for synchronizing the contractility of the myometrial cells during parturition. 2 d before parturition, there was a detectable elevation of beta 2 transcripts and protein in the endometrial epithelium, which was then followed by a dramatic decrease in beta 2 gap junctional protein on the day before parturition. There was also a substantial elevation of alpha 1 transcripts (a 6.7-fold increase) in the stromal regions of the ovary on the day before parturition that was identical to the temporal pattern of alpha 1 expression in the myometrium. In all three instances--the alpha 1 transcripts in the myometrium, beta 2 transcripts in the endometrium, and alpha 1 transcripts in the ovary--the transcript modulation appeared to be cell specific, because the changes in transcript levels of these three gene products occurred independently of the poly(A) + RNA concentrations at the same pregnancy stages in the respective organs. There were no specific changes detected in gap junction transcript levels in the heart and liver during pregnancy. These observations indicate that a cell-specific modulation of gap junction expression occurs in two regions of the uterus and the ovary during pregnancy. Further, it appears that the same gap junction gene in different organs, such as the alpha 1 gene in the uterine myometrium and the heart, can be differentially regulated.

Animals↗
PubMed1990

Aspirin concurrently administered with ranitidine does not delay healing of duodenal ulcer.

Sixty-nine patients with endoscopically diagnosed duodenal ulcer were randomised to either Group I or Group II. Group I patients (n = 35) received tablet ranitidine 150 mg twice daily along with tablet aspirin 600 mg three times a day while Group II patients received only tablet ranitidine 150 mg twice daily. Eight patients (four in each group) dropped out of the trial but were included in the final analysis as failure of treatment. At the end of four weeks 51.4% ulcers healed in Group I compared to 58.8% in Group II. The difference between the two groups was not significant. There was also no statistical difference in the time required for relief of pain, number of patients relieved of pain and the complication rate. It is concluded that aspirin concurrently administered with ranitidine is safe and does not delay the healing of uncomplicated duodenal ulcers.

Adult↗
PubMed1990

Human immune response directed against Plasmodium falciparum heat shock-related proteins.

Heat shock-related stress proteins present in all eucaryotes and procaryotes have been shown to be immune targets in a broad range of infections. We have analyzed sera from people exposed primarily to Plasmodium falciparum for specific antibodies against two heat shock-related proteins (proteins similar to the heat shock protein with a molecular weight of 75,000 [Pfhsp] and a glucose-regulated protein with a molecular weight of 72,000 [Pfgrp]). In an immunoprecipitation analysis with metabolically labeled parasites and synthetic peptides in an enzyme-linked immunosorbent assay, specific antibodies against Pfhsp and Pfgrp were detected in the sera of these individuals. Sera from people exposed to a different human malarial parasite, Plasmodium vivax, did not react with the peptides in an enzyme-linked immunosorbent assay. Southern blot analysis with DNA isolated from P. falciparum from different geographical locations showed a conservation of genes for these stress proteins; thus, they are likely to be immune targets in various endemic areas. Lymphocytes from two tested immune donors responded in proliferation assays to purified Pfhsp and Pfgrp and purified recombinant proteins. However, a similar response was also seen in lymphocytes from nonimmune individuals and has raised questions pertaining to a generalized responsiveness of lymphocytes to some common determinants present in heat shock-related proteins in various pathogens.

Animals↗
PubMed1990

The spectrum of neurologic disease associated with anti-GM1 antibodies.

We compared anti-GM1 IgM antibody titers in patients with various neurologic diseases and in normal subjects. We found increased titers in patients with lower motor neuron disease, sensorimotor neuropathy, or motor neuropathy with or without multifocal conduction block. In patients with other diseases, titers are similar to those in normal individuals, suggesting that anti-GM1 antibody levels are not increased nonspecifically after neural injury or inflammatory diseases. Anti-GM1 antibodies in many of the patients occur as monoclonal gammopathies, predominantly of lambda light-chain type, but the antibodies are sometimes polyclonal with normal or increased serum IgM concentrations. Most of the anti-GM1 antibodies appear to react with the Gal(beta 1-3)GalNAc epitope which is shared with asialo-GM1 and GD1b, but in some patients the antibodies are more specific for GM1 and associated with motor neuropathy. Patients with motor or sensorimotor peripheral neuropathy or lower motor neuron disease should be tested for anti-GM1 antibodies or anti-Gal(beta 1-3)GalNAc antibodies, as therapeutic reduction in antibody concentrations was reported to result in clinical improvement in some patients.

Adult↗
PubMed1990

A study of dietary cholesterol induced changes in serum lipid lipoproteins in healthy male children, adolescents and middle aged volunteers.

The present study comprised of 16 healthy male subjects of 8-12 years (Group A), 18 adolescent males (13-19 years) (Group B) and 20 middle aged volunteers (45-55 years) (Group C), who were fed a high cholesterol high fat diet (HCFD) consecutively for seven days. The serum lipid changes were noted. The diet was then withdrawn. Seven days later the lipid changes were again recorded. At basal stage, serum total cholesterol (STC), high density lipoprotein (HDL) and low density lipoprotein (LDL) were significantly higher in group C in comparison to Group A. LDL/HDL ratio was significantly lower in Group C than that of Group A. Seven days after feeding of HCFD significant elevations occurred in all the lipid subfractions of Groups AB. The rise in STC was mainly because of predominant rise in HDL leading to a significant fall in LDL/HDL ratio. In Group C, elevations occurred in all the lipid fractions except HDL that showed an insignificant rise. LDL/HDL ratio was insignificantly affected. After withdrawal of HCFD, all the lipid levels returned to normal except in Group A, where STC and LDL remained elevated. The LDL/HDL ratio again increased significantly. In conclusion, the serum lipid lipoprotein behaviour in response to HCFD is qualitatively different in young persons as compared to middle aged persons.

Adolescent↗
PubMed1990

Long term behaviour of healed duodenal ulcer with and without maintenance therapy.

Seventy six patients who showed complete ulcer healing at endoscopy were treated within 48 hr with either placebo (41 patients) or cimetidine 400 mg nocte (35 patients) as a maintenance therapy for a period of one year in a double blind controlled study. Patients were reviewed every month and an endoscopy was performed every 3 months after starting the treatment or earlier if there was recurrence of symptoms. During the first three months of treatment the relapse rate in the two treatment groups were similar. The difference between the two first became obvious at 4 mo, but statistically significant difference appeared only at 6 mo: 70.7% in the placebo group suffered a relapse compared to 42.9% in the cimetidine group (x2 = 6.01; p less than 0.02). The difference remained significant until the 10th mo (78.1% vs 48.6%; x2 = 7.16; p less than 0.01). At 12 mo, the difference was not significant (80.5% vs 62.9%; x2 = 2.93). The age, sex, duration of illness, previous treatment and blood group status did not influence ulcer relapse. However, two factors had an influence on the relapse rate: a) in patients receiving placebo the relapse rate was significantly greater in smokers compared to non smokers; no such difference was observed in the cimetidine group. Moreover, smokers on cimetidine had a significantly lower relapse rate at 6.9 and 12 mo compared to smokers on placebo (50% vs 88.9%, 50% vs 94.4% and 53.3% vs 94.4%; p less than 0.01 for each).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Post heparin lipoprotein lipase activity in patients of ischaemic heart disease and in controls.

A single high fat meal diet (66 gm fat) was given to 30 healthy males and 20 male patients of ischaemic heart disease (IHD). Ten minutes prior to the 4th postprandial hour, 500 units of heparin--a lipoprotein lipase (LPL) activator--was given, and its effect seen on serum triglyceride (STG) levels observed. Besides higher fasting STG levels, the decline in 4 hour post-prandial STG level was significantly lower in patients of IHD. One explanation for higher fasting STG values and prolonged postprandial lipaemia in these subjects could be deficient LPL activity.

Adult↗
PubMed1990

Papillary carcinoma of a thyroglossal duct remnant with Hashimoto's thyroiditis.

A rare case of papillary carcinoma of the thyroglossal duct remnant with Hashimoto's thyroiditis of the nonneoplastic ectopic thyroid tissue and the thyroid gland is described. The need for fine-needle aspiration cytologic examination in the management is stressed. The prognosis is excellent when the tumor is limited to the ectopic thyroid tissue and managed by a combination of the Sistrunk procedure and subtotal thyroidectomy followed by long-term thyroid suppression.

Adult↗
PubMed1990

Colonoscopic polypectomy. North Indian experience.

Colonoscopic snare polypectomy was carried out in 70 patients (40 children, 30 adults). There was a male preponderance in both the groups with a combined male: female ratio of 4.4:1. The majority of patients (85%) were aged 20 years or below. All patients presented with intermittent bleeding per rectum, ranging from 2 months - 6 years (mean 1.2 +/- 1.1 years) in children and 1-14 years (1.9 +/- 2.3) in adults. The majority of patients polyps were located in the rectum (73%) or in the rectosigmoid region (21%). Polyps were significantly more common in the rectum (80% vs 63%; P less than 0.01) and less frequent in the rectosigmoid (15% vs 30%; p less than 0.01) in children as compared to adults. A single polyp was present in 49 (70%) patients; 17 (24%) had 2-10 polyps, while 4 patients (2 children, 2 adults) had more than ten polyps. Most patients (94%) had polyps of less than 2 cm size. Histologically, the most polyps (91.5%) were of the juvenile variety; 39 (97.5%) children and 25 (83%) adults had this variety of polyp. The remaining 5 (17%) adults and one (2.5%) child had adenomatous polyps. The difference in the polyp histology between the two age groups was statistically significant (p less than 0.05). Only one patient (1.4%) had excessive bleeding following polypectomy. The present study suggests two important differences in the nature of polyps as compared to the West: 1) our patients were much younger, and polyps were rare after 40 years; and (2) histologically, the commonest polyps were of the juvenile variety (91.5%) while adenomatous polyps were rare (8.5%).

Adolescent↗
PubMed1989

31P-nuclear magnetic resonance studies of the effect of recombinant human interleukin 1 alpha on the bioenergetics of RIF-1 tumors.

The effect of a single injection of human recombinant interleukin 1 alpha (IL-1 alpha) on s.c. RIF-1 tumors in mice was studied by in vivo 31P nuclear magnetic resonance spectroscopy. Spectra were obtained before and up to 24 h after IL-1 alpha. At 2, 4, 6, and 8 h after IL-1 alpha injection, RIF-1 tumors exhibited a reduction in bioenergetic status compared to untreated controls. The Pi to beta-nucleoside triphosphate and the phosphomonoester to beta-nucleoside triphosphate ratios increased, while the phosphocreatine to Pi and phosphodiester to phosphomonoester ratios decreased. Tumor blood flow, estimated by 86RbCl uptake, decreased within 30 min after IL-1 alpha treatment. Minimum perfusion was detected at 4 h, with recovery between 6 and 12 h after IL-1 alpha treatment. Histological sections of the RIF-1 tumors revealed intravascular congestion by 2 h, extravascular hemorrhage by 4 h, and necrosis by 12 h after treatment with IL-1 alpha. The time course of bioenergetic changes in RIF-1 tumors determined by 31P-NMR spectroscopy was found to parallel the reduction and subsequent recovery of tumor blood flow.

Animals↗
PubMed1989

Subdural empyema--an unusual presentation. A report on 2 cases.

Two cases of subdural empyema with unusual clinical features are described. Both had an undetermined primary source of infection, the onset was insidious and the course was rather indolent, and both cases occurred after steroid therapy. Subdural empyema is a potentially lethal condition if inappropriately managed. A high index of suspicion and prompt definitive treatment remain the cornerstones of successful management. The aetiology and pathogenesis of subdural empyema and the merits and demerits of various investigative procedures are discussed; the factors that influence prognosis are highlighted.

Adult↗
PubMed1989

Nickel-induced histopathological alterations in the gill architecture of a tropical freshwater perch, Colisa fasciatus (Bloch & Schn.).

The effect of a sub-lethal concentration of 64 ppm (2.279 x 10(-4) mol l-1) of nickel sulphate (NiSO4.7H2O) on the gill of a freshwater tropical perch, Colisa fasciatus, was investigated after 96 h exposure. Prominent changes noticed were: hypertrophy of respiratory and mucous cells; separation of the epithelial layer from the pillar cell system; cauterization and sloughing; extensive necrosis of the epithelium; and hyperplasia leading to clubbing at the tip of the lamellae.

Animals↗
PubMed1989

Newer techniques of laryngeal reinnervation.

We relate the experience obtained in the use of the right superior laryngeal nerve (motor branch)--cricothyroid muscle pedicle flap in dogs in an attempt to reinnervate the right posterior cricoarytenoid muscle (PCA). The right vocal cord was paralyzed by severance and removal of 2.5 cm of the right recurrent laryngeal nerve. Evaluation 6 months postoperatively revealed the vocal fold remobilization on the right side to have an average of about one half the mobility of the left, normal side. After the recurrent laryngeal and superior laryngeal nerves on the left were severed, the vocal cord mobility dropped to only about one fourth. This suggests that the dogs had contralateral reinnervation. Nevertheless, the right vocal cord mobility, driven only by the right superior laryngeal nerve, was enough to secure an adequate airway without the need for a tracheotomy. This experiment was statistically significant on comparison with a control group. Electromyographic studies as well as PCA histochemistry were performed.

Animals↗
PubMed1989

Comparative pharmacokinetic and pharmacodynamic study of four different brands of propranolol in normal volunteers.

The pharmacokinetic and pharmacodynamic studies of four different brands of propranolol (Inderal, Ciplar, Corbeta and Propal) were carried out after single and multiple dosing on six normal adult healthy volunteers in a randomized crossover fashion to determine any inter-brand variations in bioavailability and pharmacodynamic effects. No significant difference was observed in any of the pharmacokinetic and pharmacodynamic parameters of four different brands of propranolol studied.

Adult↗