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Biomedical subjects

I Singh

Publications and source records attributed to I Singh.

At least 361 records · Page 20Linked to original sources

Effect of furosemide on plasma fibrinolytic activity and urokinase excretion.

Plasma fibrinolytic activity, as measured by the fibrin-plate method, is enhanced after a single intravenous administration of 40 mg of furosemide. This effect becomes evident within 30 min and a peak response is attained 6 h after i.v. administration. On successive administration of furosemide, the fibrinolytic effect persists and the second peak becomes manifest again after 6 h. Following the parenteral administration of furosemide there is an initial decrease of urinary urokinase excretion which returns to a normal level after 3 to 6 h. Possible mechanisms which may explain the enhanced fibrinolytic activity after furosemide administration are discussed.

Endopeptidases↗

Studies on heat output from the hand of frostbite subjects.

We studied 12 subjects, who had suffered first- to third-degree frostbite at high altitude during winter, at Delhi, India. At normal sea level pressure there (PB 740 mm Hg) and in a decompression chamber at a simulated altitude of 4085 m, the studies were at both 26 degrees C and 6.8 degrees C. A group of control (non-frostbite) subjects of comparable age were also studied for their heat output at 26 degrees C, PB 740 mm Hg. Heat output from the hands of a group of mountaineers from the sea level was also studied at 2121 m at 25 degrees C and 4485 m at 7 degrees C. The results indicated that the frostbite subjects had a significantly higher heat ouput at PB 740 mm Hg and 26 degrees C than the non-frostbite subjects. When the former were tested at sea level (PB 740 mm Hg) at 6.8 degrees C, the hand heat output showed a marked and significant decrease. On testing them at a simulated altitude of 4085 m at 26 degrees C and at 6.8 degrees C, a very highly significant reduction in hand heat output was observed compared to their initial value at sea level (740 mm Hg) and 26 degrees C. Their hand heat output also showed a very highly significant decrease compared to mountaineers at 4485 m and 7 degrees C.

Adult↗

Anatomical evidence of one-sided forelimb dominance in the rhesus monkey.

1. Differences in muscle and bone weight in the right and left forelimbs have been studied in twelve Rhesus monkeys. 2. There is anatomical evidence suggestive of one-sided limb dominance in nine animals, dominance being right sided in six animals and left sided in three animals. 3. The mean weights of all muscles and bones are greater on the dominant side except for the pectoralis major, the teres major and the clavicle. 4. The mean weight of the pectoralis major is greater on the non-dominant side and that of teres major and clavicle is equal on the two sides. The significance of these findings has been discussed in the light of observations in human adults and foetuses.

Animals↗

Some properties of purified skeletal muscle alpha-actinin.

Highly purified alpha-actinin can be made by using the low ionic strength extraction procedure previously described (Arakawa N., Robson, R. M., and Goll, D. E. (1970) Biochim. Biophys. Acta 200, 284-295) and then subjecting the crude alpha-actinin fraction obtained with this extraction procedure to successive chromatography on DEAE-cellulose and hydroxyapatite. Hydrozyapatite chromatography specifically removes a protein having a subunit molecular weight of 42,000 on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Hydroxyapatite-purified alpha-actinin sediments entirely as a 6.21 S boundary in the analytical ultracentrifuge with no trace of the small 9 to 10 S boundary seen in earlier alpha-actinin preparations purified by DEAE-cellulose chromatography. In 100 mM KCl, 20 mM Tris-acetate, pH 7.5, hydroxyapatite-purified alpha-actinin has a diffusion coefficient (D020,w) of 2.71 X 10(-7) cm2-s-1, an intrinsic viscosity of 20.6 ml-g-1, a molecular weight of 201,000 +/- 4,300 (plus or minus least squares standard error) as determined by sedimentation equilibrium, and a molecular weight of 210,000 as determined by sedimentation diffusion. In 6 M guanidine HCl, hydroxyapatite-purified alpha-actinin has a molecular weight of 106,000 +/- 6,300 as determined by sedimentation equilibrium and a molecular weight of 100,000 as determined by a calibrated 4% agarose gel permeation column. SDS-polyacrylamide gel electrophoresis gives a molecular weight of 96,000 to 100,000 for hydroxyapatite-purified alpha-actinin. Rod-shaped particles 44 X 390 to 400 A are seen in electron micrographs of negatively stained alpha-actinin. By assuming 45% hydration and a molecular weight of 206,000, dimensions of approximately 40 X 500 A can be calculated for the alpha-actinin molecule by using either s 020, w, D 020, w, intrinsic viscosity, or a calibrated 6% agarose gel permeation column. Hydroxyapatite-purified alpha-actinin has an alpha-helical content of 74% as measured by circular dichroism at 208 nm.

Actinin↗

The depletion of the granules of argentaffin and argyrophile cells of monkey duodenum by reserpine.

The influence of reserpine (5 mg/kg) on the argentaffin and argyrophile cells has been studied in 4 monkeys, and in 4 controls. In the treated animals, there is a marked and obvious reduction in the number of argentaffin cells; the cells that remain also show signs of partial depletion. Reduction of the number of argyrophile cells is not obvious on casual examination, but cell counts reveal a statistically significant reduction. The persisting argyrophile cells show signs of partial depletion.

Animals↗

Isolation and partial purification of plasma membrane-associated antigens from human osteosarcoma (TE-85) cells in tissue culture.

The plasma membrane of a cloned line of TE-85 (human osteosarcoma) cells subcultured for the last 4 years was isolated. The isolation was by hypotonic swelling, cell homogenization, and discontinuous sucrose gradient ultracentrifugation for 16 hr. Tumor-specific water-soluble antigens were identified by limited papain digestion of the isolated plasma membrane. Fractionation by diethylamino-ethyl anion-exchange column chromatography yielded antigenic fractions that inhibited the reaction of immune serum (from an unrelated patient with osteosarcoma) with the plasma membrane of TE-85 cells in tissue culture by indirect immunofluorescence test. Microimmunodiffusion confirmed the specificity of the isolated antigen against the sera of other patients with osteosarcoma. The definition of the antigen fraction may permit evaluation of antigen-antibody interaction in tumor immunity.

Antigen-Antibody Complex↗

A photometric method for quantitative estimation of the area of irregular microscopic objects.

The area of small irregular microscopic objects can be estimated by projecting the image of the objects on to tracing paper, making a tracing using a fibre tipped sketch pen, eluting the ink from the paper, and estimating the colour photometrically. Similarly treated spots of known area are used as standards. The method can also be used to measure the lengths of lines that are too complicated to be measured by other means.

Biometry↗

Sodium acetate buffer: a diluent of choice in the clot lysis time technique.

Sodium acetate buffer, 0.12 M, pH 7.4 as a diluent in the low temperature technique of dilute clot lysis time, is more effective in accelerating the velocity of lysis than phosphate buffer of similar pH and molarity. A uniform shape of the clot is maintained throughout the digestion in sodium acetate buffer and the end point of lysis is characteristically marked by an abrupt and sharply defined disintegration. Sodium acetate buffer can be employed advantageously in this technique not only to improve the observation but also to shorten the lysis times.

Acetates↗

Fibrinolytic activity at high altitude and sodium acetate buffer.

At high altitude there is a tendency for fibrinolytic activity to be enhanced depending, perhaps, on the duration of exposure and this seems to be a protective mechanism against the development of high altitude pulmonary oedema which is associated with diminished fibrinolytic activity. The fibrinolytic response at high altitude seems to be fluctuated during the process of acclimatisation though being maintained at a plateau higher than that in the plains. It apparently results from hypoxic stress but more likely reflects the physiological response to the hypercoagulable state at high altitude. As clot lysis times in high altitude pulmonary oedema are unusually prolonged an attempt at shortening their observation in the test system is desirable. Sodium acetate, 0.12 M solution with pH 7.4 as a diluent in the low temperature technique of dilute clot lysis time is potentially effective to accelerate the lysis time by approximately 33% compared to phosphate buffer solution of similar pH and molarity. Also the end point of disintegration of clot is more abrupt and sharply defined. Sodium acetate buffer can advantageously replace phosphate buffer as a diluent in this technique.

Acetates↗