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Biomedical subjects

G S Gupta

Publications and source records attributed to G S Gupta.

At least 37 records · Page 2Linked to original sources
PubMed1993

Modulation of allo-immune responses in vivo and in vitro by sperm specific lactate dehydrogenase-C4.

The role of sperm specific lactate dehydrogenase-C4 (LDH-C4) in allo-immune responses using mixed lymphocyte cultures (MLC) and cytotoxic T cell (CTL) generation in vitro and local graft versus host (LGVH) reaction and allograft enhancement in vivo has been ascertained. LDH was purified from testes (LDH-C4) and kidney (LDH-B4) of C57Bl/Ks mice. MLC and CTL were performed using C57Bl/Ks-anti A/J lymphocytes in presence of 10(-3)-1 micrograms LDH-B4 or LDH-C4 per culture. The MLC and CTL responses showed biphasic action depending on the dose of LDH-C4. Early MLC culture gave significantly low stimulation index at 10(-2)-10(-1) micrograms LDH-C4 as compared to non-treated control cultures. However, the MLC response in presence of LDH-C4 was not different from the LDH-B4 treated one which showed a similar biphasic trend. On the other hand, 51Cr release from YAC-222 target cells was practically abolished by LDH-C4 at 10(-3)-1(-1) micrograms, and this was strikingly different from LDH-B4 or non-treated cultures. LGVH reactivity as performed by using C57Bl/Ks lymphocytes along with LDH-C4 in (C57Bl/Ks x A/J) F1 hybrids indicated a suppression of stimulation index in primary and secondary (i.e. preimmunized in presence of LDH-C4 or LDH-B4) LGVH. Allograft enhancement of Sa I (A/J) in C57Bl/Ks mice in presence of LDH-C4, was delayed slightly but significantly during primary or secondary transplantation reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Modulation of biochemical and cytological profile of bronchoalveolar lavage constituents in rats following split-dose multiple inhalation exposure to methyl isocyanate.

1. Studies were carried out to explore the acute pulmonary effects of equal, split-dose, multiple inhalation exposures of rats to methyl isocyanate (MIC), (0.32 mg l-1, 8 min x 10 exposures) as reflected by alterations in bronchoalveolar lavage fluid (BALF) constituents and to evaluate recovery, if any, following survival in a MIC-free environment, 10 d after the last MIC exposure. 2. In the BALF of MIC-exposed rats, there was an increase in the total number of cells and the number of cells showing enhanced dye uptake and reduction of nitroblue tetrazolium chloride. The cell-free BALF showed increases in total protein, sialic acids and lactic acid contents and lactate dehydrogenase activity. 3. In rats exposed to MIC and sacrificed 10 d after survival in a MIC-free environment, there was a reduction in the cellular and biochemical constituents of BALF. The phagocytic potential of macrophages was, however, also decreased under this regime.

Administration, Inhalation↗
PubMed1993

Expression and regulation of insulin-like growth factor-I in the rat incisor.

Growth factors play an important role in the regulation of cell growth, division and differentiation. In this study the distribution and regulation of insulin-like growth factor-I (IGF-I) in the continuously erupting rat incisor was determined by immunohistochemistry. Results were evaluated both visually and with a computer-based image analysis system. The distribution and intensity of IGF-I immunoreactivity varied with developmental stage of the rat incisor. Strong IGF-I immunoreactivity was observed in differentiating odontoblasts and ameloblasts. The most intense immunoreactivity was observed in secretory ameloblasts, secretory odontoblasts and in maturation ameloblasts. Staining was weak or absent in post-secretory ameloblasts but persisted in post-secretory odontoblasts. Weak to moderate immunoreactivity was also seen in cells of the stratum intermedium and in the reduced enamel epithelium. Surrounding alveolar bone showed strong IGF-I immunoreactivity in osteoblasts and in the stratum basale and stratum spinosum of the adjacent labial gingival epithelium. In order to assess the role of GH in IGF-I expression, GH (65 micrograms/100 g bw) was administered for six days to dwarf GH deficient rats, producing a significant increase in body weight (P < 0.01). Measurements at different stages of odontogenesis showed that the staining intensity of secretory ameloblasts (P < 0.01) and maturation ameloblasts (P < 0.001) was significantly different between untreated and treated animals. These results indicate that IGF-I is present in cell populations of the enamel organ of the rat incisor found previously to exhibit growth hormone receptors, and that expression of IGF is GH dependent.(ABSTRACT TRUNCATED AT 250 WORDS)

Ameloblasts↗
PubMed1993

Histomorphological changes in lung of rats following exposure to wood smoke.

Rats were exposed to repeated, intermittent exposure to smoke generated from combustion of 1g wood/15 min, total period for 75 min daily under dynamic exposure conditions, over a period of 15, 30 and 45 days. First 15 days exposure caused mild bronchiolitis, hyperplasia and hypertrophy of bronchiolar epithelial lining cells, some necrosed lining cells desquamated into lumens, congestion of parenchymatous blood vessels, oedema, hyperplasia of lymphoid follicles, peribronchiolar and perivascular infiltration of polymorphonuclear cells, and mild emphysema. These lesions progressed further during 30 and 45 days of exposure, though emphysematous changes remain constant. By 30 days and 45 days, hyperplastic and hypertrophic changes of bronchioles become quite marked, with mononuclear cells infiltration and alveolar septa thickening. Hematological studies show marginal alterations in hemoglobin levels, ESR, PCV and TLCS during 15 days, where as significant changes in eosinophil were observed during 30 and 45 days, and ESR during 45 days only. The results indicate progressive pathomorphological pulmonary lesions with subsequent exposure to wood smoke in controlled conditions.

Animals↗
PubMed1992

Toxic effects of omega chrome red ME and its treatment by adsorption.

Toxic effects of Omega Chrome Red ME, a popular textile dye, on the nitrogen fixing cyanobacterium Nostoc calcicola were studied. The growth of N. calcicola was found to be suppressed at 10 and 20 mg liter-1 initial concentrations of dye, whereas a low initial concentration of 5 mg liter-1 slightly favors growth. Removal of the dye was carried out by adsorption using some cheap and unconventional adsorbents like coal, fly ash, wollastonite, and china clay. It has been observed that, in all cases, the low adsorbate concentration, the low temperature, and an acidic medium favor the dye removal process. The process of uptake follows first-order adsorption rate expression and obeys Langmuir's model of adsorption. The removal process is also partially diffusion controlled. Thermodynamic and pH studies were run to explain the results.

Adsorption↗
PubMed1992

Ranking toxicity of industrial dusts by bronchoalveolar lavage fluid analysis.

Female wistar rats were inoculated intratracheally with 10 mg/ml suspensions of various dusts, viz: quartz, fly ash, mica and corundum in physiological saline. Biochemical markers of bronchoalveolar lavage fluid (BALF) were analysed 8 days after the instillation of the dusts. Elevated levels of proteins, sialic acid and phospholipid contents and the activity of lactate dehydrogenase correlated well with the degree of the known fibrogenic potential of different dusts in the lungs in the following order, quartz greater than fly ash greater than mica greater than corundum. beta-glucuronidase activity, was however, only elevated in the quartz inoculated group of rats. It is suggested that biochemical constituents of BALF analysed shortly after the exposure to different dusts can be useful to mirror alterations in the tissue response to mineral dusts.

Aluminum Oxide↗
PubMed1992

Modulation of T cell functions by sperm-specific lactate dehydrogenase: fluorescence analysis of immune competent cells and local graft versus host reaction.

Immune responses to a well-defined sperm-specific isogenic lactate dehydrogenase-C4 (LDH-C4) have been studied in C57Bl/Ks (H-2d) mice after immunization through intra-rectal route. Presence of anti-LDH-C4-antibodies in the sera of females immunized in presence or absence of adjuvant suggested that the immune system of mice becomes exposed to sperm antigens following intrarectal insemination. LDH-C4 primed lymphocytes from both males and females, when transferred in F1 hybrids, suppressed stimulation index of local graft versus host reaction. However, contrary to females, male counterparts which did not elicit measurable anti-LDH-C4-antibody titer, showed the presence of a higher proportion of Ly2+ and Ia+ fluorescence labelled cells in the spleen of LDH-C4 administered mice. Results suggest that males are more susceptible for immune suppression of T cell functions through generation of T suppressor cells. Sex differences in relation to immune deviation by intra-rectal administration of sperm-specific LDH-C4 in mice and their consequences in AIDS and AIDS-related complex diseases are described.

Animals↗
PubMed1991

Inhalation toxicity of methyl isocyanate: biochemical and cytological profile of bronchoalveolar lavage fluid in rats.

Acute pulmonary injury in rats following a single inhalation exposure to methyl isocyanate (3.2 mg l-1) was reflected by alterations in the biochemical and cytological constituents of bronchoalveolar lavage fluid (BALF) over a period of 30 days. Total protein, sialic acid and lactic acid contents of BALF were increased followed by a gradual decline to normalcy between day 3 and day 30 post-exposure. The activity of lactic dehydrogenase also increased progressively with time. The cellularity of BALF was increased significantly and primarily comprised of polymorphonuclear neutrophils at 8 days. The adherence of macrophages was unchanged but their viability was lowered at 30 days post-exposure. The results indicate the significance of bronchoalveolar lavage analysis in monitoring pulmonary toxicity by methyl isocyanate, which is characterized by the hypoxic condition and reduced cellular defence. Some toxic manifestations are potentially reversible with time after cessation of exposure.

Administration, Inhalation↗
PubMed1991

Chronobiology of urinary citrate excretion amongst stone-formers and healthy males from north western India.

Urinary citrate excretion was estimated colorimetrically from urine samples collected every 3 h for 24 h from 25 healthy adult males (non-stone formers; mean age 39 +/- 7 years) and 25 male patients suffering from calcium nephrolithiasis (stone formers; mean age 41 +/- 6 years). The 24 h citrate excretion was 2.47 +/- 0.65 mmol in non-stone formers and 2.02 +/- 0.71 mmol in stone formers. This difference was not significant. However, cosinor rhythmometry revealed a significant circadian rhythmicity in urinary citrate excretion in the healthy males which was absent in the stone formers; the amplitude was 0.06 mmol in non-stone formers and 0.017 mmol in stone formers. The acrophase was located at 14:25 h in non-stone formers and at 23:30 h in stone formers.

Adult↗
PubMed1991

Oxidative damage and changes in the glutathione redox system in erythrocytes from rats treated with hexachlorocyclohexane.

The concentration of reduced glutathione in the erythrocytes of rats was significantly decreased 24-72 hr after the rats were treated with 300 mg commercial hexachlorocyclohexane/kg body weight (one-third of the LD50), given ip. The activities of glutathione reductase, glutathione-S-transferase and glucose-6-phosphate dehydrogenase were also significantly decreased 24 hr after treatment but there was no change in glutathione peroxidase activity. The results suggest that hexachlorocyclohexane produces significant changes in the glutathione redox system of rat erythrocytes leading to oxidative membrane damage.

Animals↗
PubMed1991

Cellular and biochemical indices of bronchoalveolar lavage for detection of lung injury following insult by airborne toxicants.

Cellular and biochemical profiles of bronchoalveolar lavage (BAL) material after inhalation or intratracheal exposure to various airborne toxicants clearly reflect that BAL has the potential of being a useful tool for the rapid screening of lung injury. The cellular and biochemical responses not only predict inflammation, extent of tissue damage and toxic nature of the substances, but could also help in understanding the molecular mechanisms of pathogenicity. Depending upon the changes of BAL in animals acutely exposed to a pulmonary toxicant, future in-depth studies along with complete histopathological evaluations could be made. Also, the assessment of macromolecules of pharmacological importance in the lavage, especially the secretory products of alveolar macrophages and other lung cell types, could be very useful in predicting the toxic potential of various airborne substances and could also serve as important indicators of developing chronic lung diseases and, therefore, necessitate further studies.

Air Pollutants↗
PubMed1990

Effect of methyl isocyanate (MIC) on rat erythrocytes.

Changes in surface morphology of rat erythrocytes were studied by scanning electron microscopy after a single and repeated exposure of methyl isocyanate under static conditions. Marked morphological changes (echinocytes and spherocytes) were observed, followed by an increase in osmotic fragility of the erythrocyte membrane. The activity of the membrane bound enzyme adenosine triphosphatase (Na+, K+, Mg++) was inhibited.

Adenosine Triphosphatases↗
PubMed1990

Hypertension and myocarditis in rabbits exposed to hexachlorocyclohexane and endosulfan.

Male albino rabbits were exposed to the organochlorinated pesticides hexachlorocyclohexane (HCH) and endosulfan (2.5 and 5.0 mg/kg, ip) twice a week for 12 mo. The mean body weight of the rabbits at 12 mo was lower than that of the controls. There was rise in blood pressure and heart rate. Electrocardiograms (ECG) in both the exposed groups showed increases in PR, QT and RR intervals. Extensive myocardial damage was recorded with marked degeneration of muscle fibers vacuolization and leucocytic infiltration. Adrenals had thickened capsules and hyperplasia of cortical cells. Both pesticides produced significant increases (p less than 0.001) of 11-hydroxycortisone at all time intervals. Hypertension and myocarditis occurred in rabbits exposed to HCH and endosulfan.

Adrenal Glands↗
PubMed1989

Kinetics and thermodynamic transitions of N-acetyl-beta-D-glucosaminidase A and B in free and bound forms: role of cellulose ion-exchangers.

The kinetic and thermodynamic properties of N-acetyl-beta-D-glucosaminidase A (Hex A) and N-acetyl-beta-D-glucosaminidase beta (Hex B) from goat testes were investigated in free and bound (after binding them on ion-exchangers such as DEAE- or CM-cellulose respectively) forms. The optimum pH of free Hex A and Hex B was at 4.2 and 5.4, whereas the bound forms showed the optimum pH at 4.0 and 5.2 respectively. While apparent Km of free and bound Hex A (0.8 and 1.0 mM respectively) did not differ, the Km of Hex B increased when bound on CM-cellulose (Km of free Hex B = 0.96 mM versus bound Hex B = 1.6 mM). Though the free Hex A was more thermo-labile than the free Hex B, both isozymes, on insoluble matrices decayed at faster rates on heating. Activation analysis revealed that the energy of activation (Eoa) for transition state of free Hex B (81 Kcal deg-1 mole-1) did not differ from Eoa of bound Hex B. On the other hand, Eoa of free Hex A declined from 77.2 to 71.1 Kcal deg-1 mole-1 when heat transitions were carried out in free and bound state respectively. Thermodynamic analysis suggested a change in entropy of activation (delta S) of free Hex A and Hex B as 200 and 211 eu respectively. While delta S of Hex B did not change after heat transitions, delta S of Hex A was 182.5 eu.

Animals↗
PubMed1989

Role of neurotransmitters in fenitrothion-induced aggressive behaviour in normal and lesioned rats.

Normal and brain-lesioned (amygdala, septal and nigral regions) rats exposed to fenitrothion (10 mg/kg) for 15 subsequent days showed elevated foot-shock fighting behaviour (septal and nigral lesioned rats). Treated animals failed to perform the rotorod test and showed decreased locomotor activity followed by convulsions. The brain-lesioned rats treated with 10 mg/kg fenitrothion showed a marked decrease in the level of norepinephrine (NE) and serotonin (5-HT).

Aggression↗
PubMed1989

The EEG response to diffuse and patterned photic stimulation during acute untreated alcohol withdrawal.

We studied the responses to diffuse and patterned stroboscopic light stimulation prospectively in 49 individuals during acute alcohol withdrawal prior to pharmacologic treatment. Photomyogenic responses (PMR) occurred in only two (4%) of those tested, and photoparoxysmal responses (PPR) never occurred. These findings suggest that PMR occur far less often during alcohol withdrawal than previously thought and that PPR may not be a direct manifestation of alcohol withdrawal.

Adult↗
PubMed1988

Effect of repeated exposure to lindane and cadmium on lindane metabolism in rats.

The effects of daily administration of cadmium and lindane for 35 days on the metabolism of lindane in rats were investigated. The results indicate that cadmium induces a significant inhibition of lindane metabolism, since the group dosed with lindane plus cadmium had a significantly higher concentration of lindane in plasma and tissues than the group dosed with lindane alone. The inhibition in the metabolic rate of lindane is associated with the cadmium-induced alterations in the disposition of essential trace elements, Zn, Cu and Fe, in the liver.

Animals↗