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Biomedical subjects

A Sharma

Publications and source records attributed to A Sharma.

At least 865 records · Page 48Linked to original sources

Profiles of type-II pneumocytes in rats inoculated intratracheally with bacterial lipopolysaccharide.

Ultrastructural and morphometric profiles of type-II pneumocytes (P-II) were investigated in rats killed 18 or 24 hours after a single intratracheal inoculation of bacterial (Escherichia coli) lipopolysaccharide (LPS). Inoculation with LPS induced pulmonary injury and inflammation, as measured by increased lactate dehydrogenase and alkaline phosphatase activities and increased numbers of polymorphonuclear neutrophils in fluid collected by bronchoalveolar lavage. Marked ultrastructural changes and desquamation of a few P-II developed at the time of high activity of lactate dehydrogenase and alkaline phosphatase in bronchoalveolar lavage fluid. Ultrastructural changes included swollen mitochondria and localized cisternal dilatation of the endoplasmic reticulum in which was contained membrane-bound homogenous material of medium electron density. Twenty-four hours after LPS inoculation, point-count stereologic analysis and digitizing morphometry revealed greater than 50% increase in P-II size. Changes in cell size corresponded with ultrastructural finding of swollen cells. Results obtained by point-count stereologic analysis and digitizing morphometry were highly correlated (r = 0.95). Lamellar bodies (LB) comprised 12 to 15% of P-II volume. Volume density and number of LB remained unaltered in LPS-injured P-II, and evidence of accelerated release of LB was not detected after LPS inoculation. Exudated polymorphonuclear neutrophils and pulmonary alveolar macrophages were involved actively in the phagocytosis of LB originating from necrotic and desquamated P-II. On the basis of measurement of enzyme activity (enzymes released into the bronchoalveolar space), considerable ultrastructural alterations developed in P-II when maximal LPS-induced pulmonary cell injury took place.

Animals↗

Sulphinpyrazone and the platelet serotoninergic mechanism in ischaemic heart disease.

A double blind study in 25 patients with ischaemic heart disease and 20 matched healthy controls examined the effect of sulphinpyrazone on the uptake of serotonin by platelets and the basal concentrations of serotonin in platelets. Uptake was measured using tritium labelled serotonin and basal concentrations estimated spectrophotofluorometrically. Serotonin uptake was significantly increased both in the patients with chronic stable angina of effort and in those with a history of myocardial infarction six months or more previously. Sulphinpyrazone reduced serotonin uptake from 94.25 (SE 8.65) to 57.86 (5.37) cpm/10(8) platelets after 24 weeks of treatment in the group with stable angina and from 137.45 (16.26) to 68.08 (8.38) cpm/10(8) platelets in the myocardial infarction group. Raised basal concentrations in the two groups were also reduced by sulphinpyrazone. Placebo had no effect on serotonin uptake or basal concentrations in either group of patients. The ability of sulphinpyrazone to inhibit uptake and reduce basal concentrations of serotonin in patients with ischaemic heart disease may be yet another mechanism through which this drug exerts its beneficial antiplatelet effect.

Adult↗

On-line clarification for the measurement of serum glucose in hyperlipidemic specimens.

The optical aberrations due to the presence of the turbidity caused by hyperlipidemia has been eliminated in two serum glucose procedures. This has been accomplished by incorporating lipase and alpha-cyclodextrin into the two glucose reagents. The hydrolytic action of the lipase generates water soluble glycerol and insoluble fatty acids. By including the chemical scavenger alpha-cyclodextrin into the reagent the fatty acids are solubilized and thus the production of a second turbidity is avoided. Because the clearing reagents are incorporated into the glucose reagents, this is an on-line process and no additional labor is required to clear the sample-reagent mixture. Furthermore, no additional time is required as the clearing occurs in the same period of time that it takes for the indicator reactions to reach equilibrium.

Blood Glucose↗

Serodiagnosis of intestinal tuberculosis by enzyme immunoassay and soluble antigen fluorescent antibody tests using a saline extracted antigen.

The efficacy of enzyme-linked immunosorbent assay (ELISA) and soluble antigen fluorescent antibody (SAFA) tests in the diagnosis of intestinal tuberculosis was compared using saline extracted surface antigen of M. tuberculosis H37Ra. Of the 24 proved cases of intestinal tuberculosis ELISA detected positivity in 92% compared with 83% detected by the SAFA test. The 2 tests showed a strong correlation with each other and yielded a clear cut difference between patients and controls, although there was some degree of overlap.

Enzyme-Linked Immunosorbent Assay↗

Occurrence and aeruginocine typing of Pseudomonas aeruginosa in buffaloes and their environment.

The occurrence and distribution of Pseudomonas aeruginosa in buffaloes and their environment was studied. Environmental sources included milkers, milking utensils, watering troughs, animal shed floor, barn-yard soil and drains. Of the different body sites examined, the organism could only be isolated from 15% of the muzzle and 5% of the belly samples. The organism was widely prevalent in the animal environment and could be isolated from milking utensils (56.67%), watering troughs (44.00%), drains (36.37%), shed floor (4.00%), barnyard soil (3.33%), and milkers' throats (50.00%) and hands before and after milking (7.14 and 10.71%, respectively). Aeruginocine typing revealed that of the 68 strains of P. aeruginosa, 65 (95.59%) were typable. Amongst the typable strains, 21 (32.30%) were classifiable and 44 (67.69%) unclassifiable. Unclassifiable pattern 23478- was most predominant and common to animals and environmental sources. Different aeruginocine types encountered were: A(2), B(4), F(1), L(1), P(4), 1(1), 8(1), 9(1), 11(3), 12(1), 14(1) and 17(1). This is of significance as most of the types encountered have been reported from clinical specimens of animal and human origin.

Animals↗

Effects of dyes (indigo carmine, metanil yellow, fast green FCF) and nitrite in vivo on bone marrow chromosomes of mice.

Effects of 3 dyes in combination with nitrite were studied on bone marrow chromosomes of mice following prolonged oral treatment. The dyes were namely, Indigo Carmine and Metanil Yellow, both of which contain a secondary amino group, and Fast Green FCF, which has a tertiary amino group. All dyes produced aberrations but Metanil Yellow showed stronger clastogenic activity than Fast Green FCF and Indigo Carmine. Nitrite alone also induced strong clastogenic activity. A combination of dye and nitrite half the normal concentrations produced synergistic effects, which may be ascribed to the formation of nitrosamines.

Animals↗

Sister chromatid exchange induced by metanil yellow and nitrite singly and in combination in vivo on mice.

In vivo sister chromatid exchanges (SCEs) induced by metanil yellow (a dye containing secondary amino group), sodium nitrite, and dye in combination with nitrite following treatment with acute doses were studied on mice. The incidence of SCEs was significantly high in both dye- and nitrite-treated series. However, a combination of half the concentrations of dye and nitrite, when used together, gave a frequency of SCE higher than that of either chemical, when given in full dose, indicating the stronger clastogenicity of the nitrosamine formed.

Animals↗

Basic fibroblast growth factor supports the survival of cerebral cortical neurons in primary culture.

Bovine basic fibroblast growth factor (bFGF) is a potent mitogen isolated from bovine pituitary glands and brain. The addition of homogeneous bFGF to primary cultures of rat cerebral cortical neurons markedly enhances cell survival and elaboration of neurites. These effects are dose-dependent, with optimal stimulation occurring at a concentration of 500 pg/ml. Maintenance of survival and neurite outgrowth require the continuous presence of bFGF. Other growth factors, such as thrombin, platelet-derived growth factor, beta nerve growth factor, and interleukin 2, have no effect on neuronal survival or process formation. Although the cellular site(s) of bFGF synthesis has not yet been established, these results suggest that bFGF may function as a neurotrophic agent in the central nervous system.

Animals↗

Biogenesis of some antibiotics in the presence of 2-chloroethylphosphonic acid.

2-Chloroethylphosphonic acid (CEPA) affected both the growth of and antibiotic production in Streptomyces aureofaciens, S. griseus, S. antibioticus, and Penicillium citrinum. Streptomyces strains seemed to be more sensitive to the presence of CEPA in the medium than did the fungus. A decrease in both growth and antibiotic production was observed with a concomitant increase in the concentration of the ethylene-releasing compound in the medium. Higher concentrations of CEPA completely inhibited the growth of the above microorganisms.

Anti-Bacterial Agents↗

Enzymic clearing of lipaemic serum following total parenteral nutrition: determination of neonatal bilirubin as a model.

Bilirubin determinations in the newborn infant are one of the many analytical tests that can yield misleading results when the specimen is either iatrogenically or naturally lipaemic. Incorporation of a recently reported enzymic clarification system into a commercially available test kit enables one to conveniently and accurately quantify both total and direct bilirubin within the present procedural characteristics of the Bilirubin Stat Analyser Photometer. This instrument measures the former directly with bichromatic spectrophotometry and the latter with a conventional diazo-type reaction. The proposed modification of existing reagents allows one to apply the assay to samples with as much as, and possibly more than 16 g/l of triglycerides which has been introduced into the vascular circulation as intravenous total parenteral nutrition.

Bilirubin↗

Macrophage spreading inhibition test as an alternate method for in vitro assessment of cell-mediated immunity against Entamoeba histolytica.

During cellular immune responses sensitized lymphocytes release a number of mediators collectively known as 'lymphokines'. The assaying of macrophage spreading inhibition (MSI) factor released by sensitized lymphocytes was employed as an alternative procedure for in vitro detection of cell-mediated immunity (CMI) in animals immunized with amoeba antigen preparation. The MSI test was compared with macrophage migration inhibition test. A well defined CMI was detectable in animals immunized by amoebic antigen in combination with Freund's complete adjuvant (FCA). Macrophage spreading was found greatly inhibited when peritoneal exudate cells from these animals were cultured in the presence of specific antigen. The optimal time for the development of typical reaction was 30 min. Incubation for a longer time resulted in macrophage clumping.

Amebiasis↗

Effect of sex, age, number of bronchoalveolar lavages and quantitation methods on the bronchoalveolar cell counts in rats.

This study was conducted to investigate the effect of sex, age, number of bronchoalveolar lavages and method of quantitation on the number of bronchoalveolar cells in rats. Forty Long Evans rats were divided into four age-sex subgroups of ten animals each. Nine consecutive bronchoalveolar lavages were done in every rat and the number of bronchoalveolar cells/mL in lavages 1-3 (L1), 4-6 (L2) and 7-9 (L3) were determined by hemocytometer and electronic cell counts (Coulter Counter). The sex or age of the rats did not show a significant effect (p less than 0.05) in the number of bronchoalveolar cells recovered from the lungs; however, there was a significant difference (p less than 0.05) in the number of cells/mL among lavages 1-3, 4-6 and 7-9 (L1 approximately equal to L2 greater than L3). A discrepancy of approximately 8% in the counts of bronchoalveolar cells was found between the hemocytometer and the Coulter Counter; however, these two methods of cell quantitation showed a significant (p less than 0.01) positive correlation (r = 0.89). No significant (p greater than 0.05) differences were found in the percentage of fluid recovery (overall mean = 94.5%) among lavages L1, L2 and L3. It was concluded that the electronic cell counting of bronchoalveolar cells is as reliable as manual counting. Although sex or age did not significantly affect the number of cells recovered from the lung, caution should be used in the number of lavages done per rat since this variable may significantly affect the results.

Age Factors↗