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Biomedical subjects

M Gupta

Publications and source records attributed to M Gupta.

At least 505 records · Page 28Linked to original sources

Reduced myocardial injury due to exogenous oxidants in pressure induced heart hypertrophy.

Changes in myocardial function, structure, high energy phosphates and lipid peroxide content were examined in hypertrophied hearts exposed to partially reduced forms of oxygen (PRFO) in an ex vivo system. Heart hypertrophy in rats was produced by narrowing of the abdominal aorta for 6, 12, 24, and 48 weeks. During this period, a stable hypertrophy and hyperfunction with no clinical signs of heart failure is reported to be accompanied by an increase in myocardial superoxide dismutase and glutathione peroxidase activities and a decrease in lipid peroxide content (Gupta and Singal, Circ. Res. 64:398-406, 1989). A 10-min perfusion of sham control hearts with PRFO caused a significant decline in the developed force, +/- dF/dt and a rise in resting tension. These changes due to PRFO were significantly less in all groups of hypertrophied hearts. PRFO produced 80.8 +/- 4.2% increase in malondialdehyde (MDA) content in sham controls, while different groups of hypertrophied hearts showed significantly lesser increase (range 45-50%) in MDA. PRFO resulted in loss of myocardial ATP and CP in control and hypertrophied groups, but this loss was significantly less in all groups of hypertrophied hearts. Both quantitative and qualitative ultrastructural changes due to PRFO were also found to be less in hypertrophied hearts. There were no significant differences among 6- to 48-week hypertrophy groups in their response to PRFO. The study suggests that endogenous antioxidants may serve as putative stabilizers of myocardial subcellular as well as contractile functions against oxidative stress.

Adenosine Triphosphate↗

Mumps hemiplegia.

Neurological involvement of mumps is commonly restricted to aseptic meningitis. However, rarely mumps is associated with more severe encephalitic illness; other known associations described with mumps are cases of transverse myelitis and Gullain Barre like illness. We report a case of hemiplegia due to mumps parotitis probably caused by involvement of carotid artery.

Carotid Artery, Internal↗

Milk progesterone determination in buffaloes post-insemination.

Milk progesterone levels were studied in 17 buffaloes between post-insemination and 30 days thereafter. Six animals were confirmed pregnant. Seven of 10 animals took greater than 24 days to return to oestrus and the pattern of change of progesterone levels indicated a steady increase from 1 ng/ml on day 2 to 20 ng/ml on day 14 post-insemination, falling subsequently to about 5 ng/ml, 2 days prior to oestrus. In pregnant buffaloes, the milk progesterone levels showed a continuous increase up to 20 days post-insemination but did not decline thereafter. In individual buffaloes returning to oestrus, a cut-off milk progesterone level of greater than 10 ng/ml was considered for pregnancy diagnosis, 20, 22 and 24 days post-insemination. The test was 60, 75 and 75% accurate for detection of pregnancy on days 20, 22 and 24 respectively and 100% for non-pregnancy diagnosis on all three days. Individual animals showed a highly variable oestrous cycle length, which has been suggested as a contributory factor for false pregnancy diagnosis by milk progesterone test in this species. Milk progesterone assay may also identify silent heats, and clinical disorders.

Animals↗

Chronic treatment of aged mice with L-deprenyl produces marked striatal MAO-B inhibition but no beneficial effects on survival, motor performance, or nigral lipofuscin accumulation.

Male C57BL/6J mice were provided I-deprenyl (at 0, 0.5 mg/kg or 1.0 mg/kg per day) in their drinking water beginning at 18 months of age. A battery of motor tests, including open-field, tightrope, rotorod, inclined screen, runwheel, and rotodrum tests, was administered before treatment and then 6 months later at 24 months of age. A subsample of mice was retested again at 27 months of age. An untreated group of 9-month-old mice served as young controls. Deprenyl treatment reduced striatal MAO-B activity by up to 60% after 6 months on treatment but had no significant effects on striatal catecholamine levels. No significant effects of deprenyl treatment were observed on body weight, fluid intake, or survival of the mice. Chronic deprenyl treatment also did not affect motor performance in any test, except rotodrum performance at 27 months of age, which was significantly better in the 1.0 mg/kg group treated group compared to controls. No age or deprenyl effects were observed with respect to cell counts in the substantia nigra. However, nigral cells containing lipofuscin increased with age, but this neurohistochemical parameter was also unaffected by deprenyl treatment.

Aging↗

Similarity of the Cin1 repetitive family of Zea mays to eukaryotic transposable elements.

It has been suggested that the middle repetitive class of sequences that make up a large proportion of the eukaryotic genome have been amplified and dispersed by DNA transposition. Transposition is a phenomenon first postulated by Barbara McClintock on the basis of her genetic analysis of mutants in Zea mays. Since then, DNA transposition has been studied genetically in various plant systems and is well documented on the molecular level in both prokaryotes and eukaryotes. This has included the isolation of DNA inserts at various loci in several plants; however, the prevalence of transposition in plants is not established. We report here DNA nucleotide sequence data which show that some members of the Cin1 middle repetitive family of maize have features characteristic of known transposable elements. One cloned Cin1 repeat has a 6-base pair (bp) perfect inverted repeat sequence at its ends. The terminal five base pairs (5' TGTTG . . . CAACA 3') are identical to the termini of Drosophila copia transposable elements. Two other Cin1 alleles are flanked by 5-bp direct repeats. A comparison is made with the long terminal repeat (LTR) of the copia-Ty1-retrovirus families of moveable genetic elements.

Base Sequence↗

Cyproterone acetate: I. Microquantity releasing device of cyproterone acetate and its failure in inducing functional sterility in male rats.

Prasad and his coworkers emphasized that microquantities of cyproterone acetate (CPA) when continuously available developed functional sterility in male rats by interfering the epididymal physiology. In our experimental rats either 2 or 3 capsules containing CPA as per the specification of Prasad were implanted subcutaneously and left for 300 and 250 days, respectively. Fertility test was made every month and it was observed that all the experimental animals were able to impregnate female rats throughout the experiment. Excepting the epididymis the weight of testes and other accessory glands did not differ from the controls in the animals which had 2 CPA capsules for 300 days; On the other hand, the animals which received 3 CPA capsules for 250 days showed significant reduction in weight of all the acessory glands including the testes.

Animals↗

Mapping of immunogenic domains on porcine zona pellucida 3 alpha and beta glycoproteins by murine monoclonal antibodies.

PROBLEM: Immunization with zona pellucida (ZP) leads to block in fertility with variable degree of ovarian dysfunctions. To design an immunocontraceptive vaccine based on synthetic peptides of zona pellucida, it is imperative to identify and define epitopes involved in sperm binding. METHOD: Epitopic domains recognized by monoclonal antibodies (MAbs) specific to either porcine ZP3 alpha or ZP3 beta glycoproteins were delineated in an enzyme-linked immunosorbent assay (ELISA) based on the ability of a MAb in solution to inhibit the binding of biotinylated ZP3 to another MAb coated on a microtitration plate. Immunoblot studies were carried out to determine the nature of reactive determinants. Porcine oocytes preincubated with MAbs were tested for sperm binding in vitro. RESULTS: Out of 23 MAbs generated, 10 had specificity for ZP3 alpha and 13 for ZP3 beta. By using these antibodies, eight epitopic domains on both ZP3 alpha and ZP3 beta were discernible. On ZP3 beta, epitopic domain DI partially overlaps with DII and DV with DVI, whereas on ZP3 alpha domains DI to DV were in close proximity with a partial overlap, suggesting the dominance of this region. All 10 MAbs against ZP3 alpha, and 10 out of 13 against ZP3 beta recognized deglycosylated forms of antigens. Seven antibodies having specificities for ZP3 alpha and ZP3 beta respectively recognized linear epitopes. MA-30, having specificity for ZP3 beta and MA-420 for ZP3 alpha and recognizing linear epitopes significantly inhibit the binding of boar sperm to porcine oocytes in vitro. CONCLUSIONS: Collectively, these studies indicate the value of utilizing MAbs for identifying and characterizing functionally significant ZP determinants. MAbs recognizing sequential epitopes will help in the elucidation of the amino acid sequence of the epitopes, which will subsequently help in design of synthetic immunocontraceptive vaccines.

Animals↗

Cytomorphology of giant cell tumor of tendon sheath. A report of two cases.

BACKGROUND: Giant cell tumor of tendon sheath (GCTTS), also known as localized nodular tenosynovitis, is a benign neoplasm that occurs principally on the digits. The cytomorphologic features of this lesion on fine needle aspiration (FNA) have not been fully characterized. CASES: In case 1, a 23-year-old female presented with a circumscribed soft tissue swelling in the left second toe. In case 2, a 16-year-old female presented with a tender swelling at the base of the right great toe. FNA smears in both instances were highly cellular, with mononuclear cells predominating and interspersed binucleated and multinucleated osteoclastlike giant cells along with hemosiderin-laden macrophages. CONCLUSION: When interpreted along with clinical data, the diagnosis of GCTTS can usually be made with certainty using FNA cytology.

Adolescent↗

Mechanism of antinociceptive effect of nimodipine in experimental diabetic neuropathic pain.

This study used streptozotocin-(STZ; 50 mg/kg, i.v.) diabetic rats and monitored the weekly thermal nociceptive thresholds for 8-week diabetes. Nimodipine (10 mg/kg i.p.) treatment initiated after 8 weeks of diabetes antagonized the hyperalgesic response in diabetic rats. However, insulin treatment showed a partial response in these animals. Thermal hyperalgesia showed reduced sensitivity to the antinociceptive effect of morphine (5 mg/kg, i.p.). Furthermore, a reduced sensitivity to the antinociceptive effect of baclofen (GABAB agonist; 4 mg/kg i.p.) was observed. Five days of treatment with MK-801 (N-methyl-D-aspartate [NMDA] receptor antagonist 0.5 mg/kg i.p.) completely reversed 8-week diabetes-induced thermal hyperalgesia. These data suggest that diabetes-induced hyperalgesia may be the consequence of increased excitatory tone within the spinal cord. An increased release of glutamate and activation of the NMDA receptor would maintain the hyperalgesic state. Reduced activity of both opioidergic and GABAB ergic inhibitory systems might accelerate the increased excitation, thus contributing to the ongoing pain in diabetic rats.

Analgesics↗