Search PubMed⌕ Search

Biomedical subjects

S Ali

Publications and source records attributed to S Ali.

At least 343 records · Page 19Linked to original sources

Biochemical studies on the toxicity of slate mine dust.

As part of a detailed experimental study of the pathogenicity of disease of slate dust workers, the early biochemical changes in rat lung from 1 to 90 days after intratracheal inoculation of slate dust of particle size below 5 micron were investigated. A severalfold increase in free cell population (initially macrophages) was elicited by the dust. The free activity of acid phosphatase tended to increase along with a break of lysosomal latency with increasing exposure period. However, actual release of enzyme activity into the acellular fraction was low. The phospholipid content varied both in cellular and acellular fractions, indicating altered turnover of membrane lipids and surfactants. At advanced periods of the study, sialic was found to be released into the acellular fraction, indicating membrane damage. Considerable decrease in glucose-6-phosphate dehydrogenase activity and free sulfhydryl content and enhanced osmotic fragility of erythrocytes were also recorded. These results indicate the potential toxicity of slate mine dust.

Acid Phosphatase↗

The auditory-visual integration test: intersensory or temporal-spatial?

Forty-two children, twenty-one boys and twenty-one girls, were tested at the beginning and end of grade one using Birch's auditory-visual integration test (AVIT) and a parallel visual-visual integration test (VVIT). Reading tests were administered at the end of grade one. No significant differences between the means of the two integration tests were observed at the beginning of the year. A differential development of the AVIT and the VVIT resulted in a significant difference between the means at the end of the year when a common variance of 58% was observed between the two tests. At the conclusion of the school year each function correlated significantly with reading (decoding), with the correlation between AVIT and reading being significantly larger than the correlation between VVIT and reading. Implications for the optometric treatment of children with learning disabilities are discussed.

Auditory Perceptual Disorders↗

Insect sex chromosomes. VI. A presumptive hyperactivation of the male X chromosome in Acheta domesticus (L.).

The functional status of the X chromosome in Acheta domesticus has been analysed at the whole chromosome level on the basis of (1) 3H-thymidine autoradiography, (2) 5-BrdU/AO fluorescence microscopy (3) in vivo 5-BrdU incorporation and (4) 3H-UdR induced aberrations. The rationale of these techniques in relation to the functional aspect of the X chromosome is that the inactive X chromosome would (1) show asynchrony in DNA synthesis, (2) show differential fluorescence, (3) respond differentially to in vivo 5-BrdU treatment and (4) the active X chromosome would show aberrations when treated with 3H-Uridine. From the results, it appears that the X chromosomes in both male (XO) and female (XX) somatic cells of Acheta are euchromatic (active). Further, the single X in the male is transcriptionally as active as the two X chromosomes in the female. In other words, the single X in the male is hyperactive when compared with the single X in the female. From this it is inferred that the male X chromosome is differentially regulated in order to bring about an equalization of it's gene product(s) to that produced by both Xs in the female. Drosophila melanogaster has a comparable system of dosage compensation. Thus, Acheta is yet another insect showing evidence for an X chromosome regulatory mechanism of dosage compensation. Additionally, it is surmised that sex determination in Acheta is based on an autosomes/X chromosome balance mechanism.

Animals↗

Pleural plaques in asbestosis: effect of Candida albicans.

Effect of chrysotile dust alone or together with Candida albicans administered intratracheally in guinea pigs was studied in the genesis of pleural plaques over a period of 12 months. A significant increase of mucopolysaccharides, phosphorus, calcium and -SH content was detected in pleural fluid of animals treated with chrysotile and Candida albicans together than in those treated with chrysotile or Candida albicans alone. The results suggest that an infection of Candida albicans accentuates the effect of chrysotile by altering the biochemical parameters preceding to the formation of pleural plaques.

Animals↗

The effects of ginseng saponins on the growth and metabolism of human diploid fibroblasts.

The action of ginseng saponins on cell numbers, glucose uptake and lactate production and the activities of specific enzymes associated with glucose oxidation, was tested using a human diploid fibroblast strain. No augmentation of cell numbers was observed. There was a significant increase in the level of cellular lactate levels and in the specific activities of enzymes associated with an anaerobic shift in metabolism. The possible relationship between these findings and the reputed efficacy of ginseng administration in the elderly is discussed.

Fibroblasts↗

Epidemiological study and comparison of pyrantel and levamisole in the treatment of roundworm and hookworm infestations.

Stool examined for presence of nematodes from 467 school students in Dacca city showed 48% ova positive cases with 22% among them cases of mixed nematode infection. Highest prevalence of 58% was observed with roundworm and 5% was hookworm infestations. Among hookworm cases, Necator americana (68%) appears to be the predominant species. Two anthelmintics-pyrantel and levamisole achieved similar high cure rate (around 97%) and Egg reduction rate of 99% in roundworm infection. However, pyrantel was observed to be more effective in hookworm infestation (87% against 60%) particularly in Necator americana cases.

Adolescent↗

Intracranial traumatic aneurysm following hypophysectomy.

A case of traumatic aneurysm of the ICa following an attempted hypophysectomy is reported, and the management of the case is discussed. Extensive review of the English literature and personal communications (Angell-James, Bateman, Symon, Richards) have revealed only four other proven cases of intracranial aneurysms following operations on the ear and nose, one each following nasal polypectomy and partial intra-nasal ethmoidectomy, trans-antral ethmoidectomy, hypophysectomy, and mastoidectomy.

Carotid Artery Injuries↗

Leptospirosis in patients from Grenada, West Indies.

Evidence of leptospirosis in humans from Grenada, W.I., is reported here for the first time. Of 139 hospital patients with pyrexia of undetermined origin, 94 were jaundiced, and 16 (17%) of these were positive for hepatitis B antigen (HBsAg) and not examined further. 20 of the remaining 123 (16%) febrile patients were positive for leptospiral antibodies; 11 of them were current or recent cases. 25 of 182 (14%) afebrile out-patients showed evidence of previous exposure to leptospiral organisms. The most frequently encountered serogroups in the 45 seropositive in- and out-patients were Icterohaemorrhagiae (38%), Panama (24%) and Canicola (11%).

Adolescent↗

Granular cell myoblastoma: another unusual esophageal lesion.

The case is presented of a 48-year-old woman with esophageal granular cell myoblastoma who was treated by local excision. A review of the literature is also included. So far as we can determine, this is the thirteenth such case reported.

Esophageal Neoplasms↗

Guanine deaminase inhibitor from rat liver. Isolation and characterization.

1. An inhibitor of cytoplasmic guanine deaminase of rat liver was isolated from liver ;heavy mitochondrial' fraction after freezing and thawing and treatment with Triton X-100. 2. Submitochondrial fractionation revealed that the inhibitor was localized in the outer-membrane fraction. 3. The method of purification of inhibitor, involving precipitation with (NH(4))(2)SO(4) and chromatography on DEAE-cellulose, its precipitability by trichloroacetic acid and the pattern of absorption in the u.v. indicated that the inhibitor was a protein. In confirmation, tryptic digestion of the isolated material resulted in destruction of the inhibitor activity. The inhibitor was stable to acid, but labile to heat. 4. The isolated inhibitor required phosphatidylcholine (lecithin) for activity. Phosphatidylcholine also partially protected the inhibitor against heat inactivation. 5. When detergent treatment was omitted, the inhibitor activity of frozen mitochondria was precipitated by (NH(4))(2)SO(4) in a fully active form without supplementation with phosphatidylcholine, indicating that Triton X-100 ruptured the linkage between inhibitor and lipid. 6. A reconstituted sample of inhibitor-phosphatidylcholine complex was precipitated in a fully active form by dialysis against 2-mercaptoethanol, but treatment of the precipitate with NaCl yielded an extract which was inactive unless supplemented with fresh phosphatidylcholine. 7. We interpret the results as evidence that the inhibitor was present in vivo as a lipoprotein and that once the complex was dissociated by the action of detergent and the protein precipitated, there was an absolute need for exogenous phosphatidylcholine for its activity. The manner in which inhibitor associated with the outer membrane of rat liver mitochondria might regulate the activity of the enzyme in the supernatant has been suggested.

Aminohydrolases↗

Induction of guanine deaminase and its inhibitor in rodent liver and brain.

1. Guanine deaminase activities in homogenates and supernatant fractions of liver and brain of rat and mouse were elevated by administration of guanine to the animals. The maximum induction in mouse tissues occurred within 24h and in rat tissues within 48h. 2. Mitochondria of rat (but not mouse) liver and brain contain an inhibitor of supernatant guanine deaminase, and this was also increased by guanine treatment. 3. Administration of ethionine, cycloheximide or actinomycin D prevented the guanine-dependent increase in deaminase activity and also the increase in mitochondrial inhibitory activity; chloramphenicol suppressed only the latter.

Aminohydrolases↗