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Biomedical subjects

I Singh

Publications and source records attributed to I Singh.

At least 343 records · Page 19Linked to original sources

Hydatid cyst causing spinal compression.

This report deals with two cases of spinal cord compression, one secondary to hydatid disease of C4 vertebra and the other due to a posterior mediastinal hydatid with an intraspinal component. After a brief review of the pertinent literature and pathogenesis of the disease, the distinguishing radiological features have been brought out.

Adult↗

A direct binding assay for rheumatoid factor serum antiglobulins using fluorescein-labelled Fc fragment of human immunoglobulin-G.

A simple routine method is described for the quantitation of antiglobulin (rheumatoid factor) in human serum irrespective of its immunoglobulin class. Papain Fc fragment of human IgG is labelled with fluorescein isothiocyanate and incubated with the serum. Bound Fc is separated from free Fc by precipitation with polyethylene glycol and measured by the fluorescence of the precipitate. Results are expressed as a percentage of the binding obtained with a normal pool serum. About 60% of seronegative rheumatoid sera and 96% of seropositive rheumatoid sera gave results more than 2SD above the mean value for normal sera. Only 17% of osteoarthritis sera gave positive results by the same criterion. A relationship is also deduced to show that if the test is carried out at a number of Fc concentrations a double reciprocal plot of bound Fc against free Fc enables both the total antiglobulin and the ratio of binding constants of antiglobulin for Fc and for IgG to be calculated. This ratio is approximately unity. Under the standard conditions the results correspond to a measurement of approximately 30% of the total antiglobulins present.

Adult↗

Treatment rationale of fractured posterior teeth.

The four types of fractures most frequently encountered in posterior teeth--obliquely directed complete fractures, vertically directed complete fractures, obliquely directed incomplete fractures, and vertically directed incomplete fractures--have been described. A detailed treatment approach for each type has been presented.

Cracked Tooth Syndrome↗

A quantitative estimation of the depletion of the granules of argyrophile cells in the gastrointestinal tract of reserpine treated Rhesus monkeys.

The depletion of the granules of argyrophile cells following administration of reserpine has been studied at various levels of the gastrointestinal tract of the Rhesus monkey. Granulation of the cells has been estimated by the photometric method of SINGH(1976). The argyrophile cells that persist after reserpine administration show a statistically significant reduction in their granulation as compared to cells of untreated controls (P less than 0.001).

Animals↗

Placenta-like alkaline phosphatases from human osteosarcoma cells.

Hormone-induced alkaline phosphatases in human osteosarcoma cells (LM) were extracted and purified. Characterization of the purified enzyme showed two distinct isoenzymes. One isoenzyme was heat labile, was homoarginine inhibited, and had the electrophoretic migration of alkaline phosphatase of human osseous origin. Immunodiffusion showed that this isoenzyme reacted positively only against anti-bone alkaline phosphatase antibodies. The second isoenzyme was heat stable, was inhibited by phenylalanie, and had the same electrophoretic migration as did alkaline phosphatase extracted from mature normal human placenta. This second isoenzyme had the same antigenicity as did the normal placental enzyme. Like the D-variant placental phenotype, this second isoenzyme was inhibited by L-leucine and ethylenediaminetetraacetic acid.

Alkaline Phosphatase↗

Resistant level of houseflies to six kinds of synthetic insecticides in Malaysia.

The resistant level of the houseflies to six kinds of insecticides, DDT, Resmethrin, DDVP, Baytex, Sumithion and Diazinon, was examined on the seven strains collected in Malaysia. It was found that their susceptibility is rather higher than that of the Takatsuki strain which is a standard strain in Japan. However, their susceptibility to Sumithion was the same or slightly lower than that of the Takatsuki strain. The resistant level to five of six kinds of insecticides was the highest in the strain of Cameron Highland. The values were close to Singh's data in 1973, and this means that the resistance of the houseflies to the insecticides is increasing in Malaysia.

Animals↗

The architecture of cancellous bone.

The architecture of cancellous bone has been studied in macerated human bones. A number of distinct types of architecture can be recognized as follows: Type I consists of a very delicate meshwork of fine rods. Type II is made up of both rods and plates. Sub-type IIa is a meshwork similar to Type I, but a varying proportion of rad are replaced by delicate plates. Sub-type IIb shows the presence of thin but large fenestrated plates with a well marked orientation in preferred planes; these are interconnected by smaller plates and rods. Sub-type IIc is made up of relatively thick and extensive arranged for the most part parallel to one another, the plates being connected to each other by fine rods. Type III is made up entirely of plates. Delicate plates may form a meshwork in which a directional orientation may or may not be apparent (Sub-type IIIa). Elsewhere better defined, larger plates may enclose tubular spaces (Sub-type IIIb). In some areas (where cancellous bone is very dense) small relatively thick plates enclose irregular spaces; the appearance may closely resemble that of a honeycomb when the spaces are small, but elsewhere the spaces may show a definite directional orientation. The wall of the marrow cavity of long bones is seldom smooth. It is characterized by the presence of plates and rods in various configurations. A distinct marrow cavity is seen in the majority of clavicles examined.

Bone and Bones↗

N- and C-terminal amino acids of purified alpha-actinin.

Highly purified bovine cardiac alpha-actinin is obtained by successive chromatography on DEAE-cellulose and hydroxyapatite of a crude fraction obtained by salting out low ionic strength extracts of bovine cardiac muscle between 0 and 30% ammonium sulfate saturation. Hydroxyapatite chromatography removes a 43 000-dalton polypeptide chain that is difficult to remove by successive DEAE-cellulose columns. Removal of all 43 000-dalton material by hydroxyapatite chromatography is accompanied by disappearance of a very small 9 to 10 S boundary in analytical ultracentrifuge diagrams of DEAE-cellulose-purified 6.2S alpha-actinin. Approximately 95% of the protein in DEAE-cellulose and hydroxyapatite-purified alpha-actinin is the 100 000-dalton alpha-actinin polypeptide as estimated by SDS-polyacrylamide gel electrophoresis. Purified bovine cardiac, porcine skeletal, chicken gizzard, and chicken breast alpha-actinins all contain leucine as the C-terminal amino acid of both polypeptide chains in the alpha-actinin molecule. Bovine cardiac and porcine skeletal alpha-actinins contain arginine as the amino acid penultimate to C-terminal leucine. None of the four different alpha-actinins studied had a N-terminal amino group available for reaction with dansyl chloride, but all four alpha-actinins contained 1.6 to 1.8 acetate residues per molecule (200 000 daltons) of alpha-actinin. It seems likely that the N-terminal amino groups of both polypeptide chains in these four alpha-actinins are acetylated. A peptide having the composition N-Ac-Asp2-Glu4 was isolated from a proteolytic digest of bovine cardiac alpha-actinin. alpha-Actinin seems to be a conserved protein molecule found in many different motile systems.

Actinin↗

Effect of xenogeneic immune RNA on normal human lymphocytes against human osteosarcoma cells in vitro.

New Zealand White rabbits were immunized with whole-cell suspensions of TE-85 cells (from a human osteosarcoma) maintained in tissue culture. RNA was extracted from the lymphoid tissues of the immunized animals. Normal human peripheral blood lymphocytes were pretreated with both the whole-cell immune RNA (IRNA) and the Sephadex column-eluted fractions of the whole-cell IRNA. Significant stimulation of the cytotoxic effect of the lymphocytes was observed following whole-cell IRNA pretreatment and pretreatment with peak III fractions eluted from the column. This increase in inhibition was observed whether the target cells were TE-85 (the immunizing cells), L.M. and M.Mc. (two unrelated osteosarcoma primary cell cultures), or TE-85-M-MSV cells (a cell line capable of producing a human osteosarcoma in immunosuppressed hamsters). No inhibition was observed when cells from other types of human tumors were used as target cells. The results suggested that the transferred immunity was directed against tumor-specific osteosarcoma antigens.

Antigens, Neoplasm↗

Study of the pituitary-thyroid functions at high altitude in man.

The alterations in serum levels of T3, T4, TSH and TBG, TSH response to 100 mug iv TRH, and urinary excretion of T3 and T4 were studied in 8 healthy men at sea level (SL), on days 1, 2, 4, 8 and 16 after arrival by air at high altitude (3,700 m, HA), and during days 5 to 7 after their return to SL. No significant alterations in serum levels of TSH and TBG or TSH response to TRH were observed during exposure to HA or on return to SL. There was, however, an acute elevation in both serum total T3 and T4. Serum total T3 from a mean basal+/-SE value of 128+/-13 ng/dl increased to 320+/-18 on day 1 and remained significantly elevated at 225+/-48 up to day 8 after arrival at high altitude. Similarly serum total T4 increased from basal level of 9+/-0.92 mug/dl to 15.2+/-1.2 and remained elevated till day 16 and it was 11+/-1.19 mug/dl during days 5 to 7 after return to SL. The urinary excretion of both T3 and T4 was decreased. These changes perhaps were the result of complex physiologic adjustments on acute exposure to high altitude, like shrinkage of the T3 and T4 distribution pools, altered binding capacities of thyroid hormones binding proteins, and a reduction in clearance of thyroid hormones from the plasma compartment; and were probably not suggestive of an enhanced thyroid activity. Their actual significance in high altitude adaptation in man is not clearly understood.

Adult↗

An animal model for human osteosarcoma.

Osteosarcomas formed in antilymphocyte serum (ALS)-treated hamsters when 2x10(6) TE-85 human osteosarcoma cells (maintained in tissue culture) infected with M-MSV (RD-114) virus were injected adjacent to the femur or the scapula; undifferentiated sarcomas formed when 1 x 10(6) cells were injected subcutaneously. Tumors were palpable 10 to 14 days after the cells were injected and grew progressively until the animals died (mean survival time was 30 days). All animals had pulmonary metastases. Neither the subcutaneous sarcomas nor the metastases contained bone or osteoid; however, the osteosarcomas adjacent ot the femur and scapula contained collagen, osteoid and calcified bone when observed by light and electron microscopy. These results indicate that the TE-85-M-MSV cell-ALS hamster system is an animal model for the study of osteosarcomas of human cell origin.

Animals↗