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Biomedical subjects

M Gupta

Publications and source records attributed to M Gupta.

At least 397 records · Page 22Linked to original sources
PubMed1986

Effect of the mycotoxin citrinin on some hormones and on enzymes and substrates of the Embden-Meyerhof pathway in mice.

The effects of six weeks treatment with multiple i.p. doses of citrinin (15, 25 and 35 mg/kg) on some hormonal activities and on enzymes and substrates of the Embden--Meyerhof pathway in mice were studied. Adenosine triphosphatase, hexokinase, lactate dehydrogenase, lactic acid and pyruvic acid decreased in blood, liver, kidney and brain of citrinin-treated mice. Glucose levels in blood, kidney and brain increased and glycogen content of liver decreased. Cortisol, triiodothyronine and thyroxine levels of serum increased, but insulin levels decreased.

Anaerobiosis↗
PubMed1986

Changes of lipid spectrum in different tissues of Furadan-treated mice.

The effects of multiple intraperitoneal doses of Furadan (0.125 mg/kg, 0.25 mg/kg and 0.50 mg/kg, respectively) for the 2nd week, 4th week and 6th week of treatment on the concentrations of total lipid and its different fractions and lipase activity in mice were studied. The following were measured in liver, kidney, brain and serum; total lipid, cholesterol (total and free), phospholipid (total and its fractions--lecithin, lysolecithin, phosphatidyl ethanolamine and lysophosphatidylethanolamine), triglyceride, free fatty acid. Lipase activity was measured in liver and serum. Furadan caused biochemical disorders of the tissues. All the aforesaid lipid fractions (except free fatty acid) are elevated significantly in liver, kidney and serum of Furadan-treated mice. Free fatty acid increased significantly in serum and remain constant in other tissues of pesticide-treated mice. All the lipid fractions except phospholipid and its fractions remained constant in brain of treated mice; total phospholipid and its fractions decreased significantly in brain of treated mice. Lipase activity decreased significantly in liver and serum of treated mice. Such disorders of lipid levels in the aforesaid tissues might be associated with CNS depressant action and structural and functional toxicity of other tissues induced by Furadan.

Animals↗
PubMed1985

Mouse ornithine decarboxylase. Complete amino acid sequence deduced from cDNA.

cDNA containing the full coding region of mouse ornithine decarboxylase was isolated. The complete nucleotide sequence of the cDNA was determined by the dideoxy method, and the amino acid sequence of ornithine decarboxylase was thereby deduced. The protein contains 461 amino acids and has a molecular weight of 51,172. The isoelectric point is predicted from the deduced amino acid sequence to be 5.1. On the basis of its amino acid sequence, the protein is predicted to be comprised predominantly of alternating domains of alpha-helix and beta-sheet.

Amino Acid Sequence↗
PubMed1985

Differentiation characteristics of human neuroblastoma cells in the presence of growth modulators and antimitotic drugs.

Morphological characteristics of undifferentiated and differentiated human neuroblastoma cells were studied. Monolayer cultures of a human neuroblastoma, IMR-32 clone, were grown in Eagle's minimum essential medium with fetal calf serum in tissue culture dishes with polystyrene film liners. After 48 h, cultures were treated with either mitomycin C and 5-bromodeoxyuridine or prostaglandin E1 (PGE1) and dibutyryl adenosine 3',5'-cyclophosphate (cAMP). A third dish was untreated to study as an undifferentiated control. Three days later, all cultures were processed for acetylcholinesterase staining, scanning and transmission electron microscopy and high performance liquid chromatography. Treatment with mitomycin/5-bromodeoxyuridine and PGE1/cAMP inhibited growth as seen by the growth curves and caused morphological differentiation as seen by the extension of long neurites. The treated cells showed increased acetylcholinesterase staining compared to the controls. With the scanning electron microscope, the differentiated cells showed long neurites, processes with beaded varicosities and growth cones. By transmission electron microscopy, these cells contained a large number of neurosecretory granules in their cytoplasm and neurites. Specialized cell contacts were also observed between the treated cells. This is the first study demonstrating that both the treated and control cells of IMR-32 clone contain large quantities of serotonin and comparatively small amounts of norepinephrine and dopamine.

Acetylcholinesterase↗
PubMed1985

Lipid spectrum in different tissues of MT81 toxin-treated mice.

The effects of different intraperitoneal doses of MT81 (2.5 mg/kg, 5.0 mg/kg and 7.5 mg/kg, respectively) for a 2-week, 4-week and 6-week treatment on concentration of total lipid and its different fractions of liver, brain, kidney, testis and serum in mice were studied. The following were measured: total lipid, free and total cholesterol, total phospholipid and its fractions (lecithin, lysolecithin, phosphotidylethanolamine and lysophosphotidylethanolamine), triglyceride, free fatty acid; lipase activity was also measured in serum, liver, and testis. Ascorbic acid content of testis was also measured. This mycotoxin (MT81) caused biochemical disorders of the tissues. Total cholesterol, free cholesterol, total phospholipid and its fractions, triglycerides and total lipids were elevated significantly in liver, serum, kidney and testis of toxin-treated animals. Free fatty acid increased significantly at a later stage in serum and remained constant in other tissues of toxin-treated mice. All the lipid fractions except total phospholipid and its fractions remained constant in brain of treated animals; total phospholipid and its fractions decreased significantly in brain of toxin-treated mice. Lipase activity decreased significantly in serum, liver and testis of treated mice. Ascorbic acid content of testis of treated animals increased significantly. Such disorders of lipid concentrations in the aforesaid tissues might be associated with the CNS depressant action and structural and functional toxicity of other tissues induced by the MT81 toxin.

Animals↗
PubMed1985

Estimation of major immunoglobulin profile in oral submucous fibrosis by radial immunodiffusion.

Oral submucous fibrosis is defined as a collagen disease. The major immunoglobulin profile of 10 patients of oral submucous fibrosis (OSF) is estimated by radial immunodiffusion technique. The possible existence of autoimmune phenomena is expressed. It was observed in the present study that the severity of oral submucous fibrosis was directly proportional to the estimated elevated levels of major immunoglobulins. This may be taken as an indicator to know the gravity of this oral condition and also to evaluate the various related gammopathies and their possible management. It is anticipated that the knowledge of the immunoprofile would open new avenues for exploration of the condition from a new dimension.

Adult↗
PubMed1985

Alterations in isoproterenol-induced cardiac metabolic changes by a quaternary analog of propranolol, UM-272.

Effect of UM-272, a dimethyl propranolol has been studied in experimental myocardial necrosis induced by isoproterenol (ISP, 85 mg/kg, SC X 2 days) in rats. Administration of ISP caused increased serum creatine phosphokinase (CPK), lactate dehydrogenase (LDH) and decreased myocardial glycogen, adenosine triphosphate (ATP) creatine phosphate (CP) and glycolysis through phosphofructokinase (PFK). Myocardial tissue lactate was markedly increased. All these changes resulted in development of myocardial necrosis as calculated from the CPK depletion from the injured myocardium. Rats given UM-272 (10 mg/kg or 20 mg/kg i.p.) 5 days before and 2 days during ISP administration showed significant improvement in all the parameters studied. Furthermore, UM-272 (20 mg/kg X 7 days) in control rats caused a significant (P less than .001) increase in ATP and CP content of the myocardium while other parameters remained unaltered. It would appear from the present study that the cardioprotective effect in ISP induced injury is not related to beta blockade as UM-272 is devoid of beta-blocking properties.

Animals↗
PubMed1985

Intraocular retinal transplants.

Embryonic rat retinae transplanted into the anterior chamber of adult rat eyes of the same or different strain survive and grow. Light and electron microscopic studies show that the transplants undergo histogenetic differentiation, resulting in the development of mature inner and outer layer neurons and Müller glial cells. Vascular connections develop between the host iris and the retinal transplant. These initial observations indicate that retinal transplantation to a recipient eye is a procedure which offers ample opportunities for the study of problems related to neural development, retinal plasticity and repair.

Animals↗
PubMed1984

Repetitive sequences and their organization on genomic clones of Zea mays.

Fourteen recombinant clones from Zea mays were studied with regard to their composition of unique and repetitive sequences. Southern hybridization experiments were used to classify restriction fragments of the clones into a unique, middle or highly repetitive class of reiteration frequency. All three classes were often found on the same genomic clone. Crosshybridization studies between clones showed that a given repeat might be present on several clones, and thus four families of highly repetitive elements were established. Heteroduplex analysis was used to show the arrangement and size of repeats common between several clones. A short interspersion pattern of unique, middle and highly repetitive DNA was found. The dispersed repetitive elements were 300-1300 bp in length. Analysis of the pattern produced by a given repeat in genomic Southern experiments suggests that some small dispersed repeats may also exist as part of a larger repeating unit elsewhere in the genome.

Journal Article↗
PubMed1984

Immunologic studies in two patients with persistent lymphocytic thyroiditis, thyrotoxicosis, and low radioactive iodine uptake.

Two patients with persistent lymphocytic thyroiditis and thyrotoxicosis were studied. Both patients presented with severe hyperthyroidism of nine months' duration and had nontender, small thyroid glands. Uptake of radioactive iodine (131I) was consistently low. Serum thyroxine and triiodothyronine levels remained elevated without remission until thyroidectomy. The serum thyroglobulin level was normal, but testing for microsomal antibody gave weakly positive results in one case. Thyroglobulin and thyroid stimulatory antibodies were not found. The ratio of helper to suppressor T cells was elevated in one case. Neither patient showed response to propranolol, prednisone, or iodine. Light microscopic and immunohistologic studies showed severe lymphocytic thyroiditis with formation of secondary lymphoid follicles. Lymphocytes were predominately T cells (OKT11-positive), primarily helper/inducer T cells (OKT4-positive). Hyperplastic nodules contained high immunoreactive thyroglobulin and thyroxine levels. Aberrant thymus was seen within the thyroid. These studies suggest the possibility of intrathyroidal stimulation and hydrolysis of thyroglobulin within thyroid cells and also support the hypothesis that T and B cell immunoregulatory defects are important in the pathogenesis of this disease.

Adult↗
PubMed1984

Changes of acetylcholine, catecholamines and amino acid in mice brain following treatment with Nuvacron and Furadan.

The effects of multiple intraperitoneal doses of Nuvacron (0.8 mg/kg) or Furadan (0.25 mg/kg) on the concentrations of brain neurotransmitters in mice were studied. The following were measured: acetylcholine, acetylcholinesterase, gamma-aminobutyric acid, epinephrine, norepinephrine, dopamine and 5-hydroxytryptamine. These pesticides caused a significant decrease in acetylcholinesterase activity and a significant increase in acetylcholine, gamma-amino-butyric acid, epinephrine, norepinephrine, dopamine and 5-hydroxy tryptamine concentrations. The increased concentrations of the neurotransmitters in mouse brain might be associated with CNS depressant action induced by the insecticides.

Acetylcholine↗
PubMed1984

MPTP alters central catecholamine neurons in addition to the nigrostriatal system.

The present studies were undertaken to determine if MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) treatment in mice alters catecholamine or serotonin systems of the brain in addition to reported effects on the dopaminergic nigrostriatal system. Male Swiss-Webster mice were injected with 30 mg/kg MPTP daily for three days. Treated and control animals were sacrificed 10 and 24 days after the last injection, and brains were prepared for serotonin immunocytochemistry and catecholamine histofluorescence. MPTP treatment resulted in a reduced number of neurons and a reduced intensity of the fluorescence in the remaining cell bodies of substantia nigra pars compacta. A reduced presence of catecholamine varicosities in the medullary raphe nuclei and the ventromedial reticular formation of the medulla was observed. Immunocytochemical studies revealed no alteration in the number of serotonin positive cell bodies in the dorsal and median raphe nuclei. We suggest that MPTP treatment selectively alters some non-nigrostriatal catecholamine systems of the brain stem in addition to its toxic effects on the dopaminergic nigrostriatal system, while leaving other non-nigrostriatal catecholamine systems intact.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1984

Molecular cloning and expression of the mouse ornithine decarboxylase gene.

We used mRNA from a mutant S49 mouse lymphoma cell line that produces ornithine decarboxylase (OrnDCase) as its major protein product to synthesize and clone cDNA. Plasmids containing OrnDCase cDNA were identified by hybrid selection of OrnDCase mRNA and in vitro translation. The two of these with the largest inserts together span 2.05 kilobases of cDNA. Southern blot analysis of DNA from wild-type or mutant S49 cells, cleaved with EcoRI or with BamHI, revealed multiple bands homologous to OrnD-Case cDNA, only one of which was amplified in the mutant cells. RNA transfer blot analysis showed that the major OrnD-Case mRNA in the mouse lymphoma cells is 2.0 kilobases long. A similar size mRNA was found in mouse kidney and was more abundant in the kidneys of mice treated with testosterone, an inducer of OrnDCase activity in that tissue.

Animals↗
PubMed1984

Fluorescence studies on the interaction of furocoumarins with DNA in the dark.

The dark interaction of furocoumarins with DNA has been studied by a fluorescence quenching technique. The intrinsic fluorescence of psoralen, 4,5', 8-trimethylpsoralen (TMP) and 8-methoxypsoralen (8-MOP) was quenched to an appreciable extent upon their noncovalent binding to DNA molecule. The analysis of the binding data revealed that TMP binds to DNA with higher efficiency than 8-MOP and psoralen, their apparent Scatchard binding constants being 13.2 X 10(5) M-1, 7.1 X 10(5) M-1, and 12.2 X 10(5) M-1, respectively. The interaction of furocoumarins with DNA was strongly dependent on the conformational stability of DNA in the particular interaction media. The perturbation of DNA structure by changing the ionic environment decreased its interaction with furocoumarins. However, the interaction was facilitated by the presence of an electron-donating moiety in the parent compound, psoralen.

Animals↗