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Biomedical subjects

A Zaman

Publications and source records attributed to A Zaman.

44 records · Page 3Linked to original sources
PubMed1991

31P magnetic resonance spectroscopy study of cerebral metabolism in developing dog brain and its relationship to neuronal function.

Cerebral metabolism and neuronal function of prefrontal brain cortex were studied in 6 dog litters from birth to 3 months of age. Noninvasive phosphorus magnetic resonance spectroscopy (31P-MRS) was used to observe longitudinal biochemical changes in the phosphorus compounds associated with cerebral metabolism. Neurological tests, examining reflex, motor and sensory nerve function, were performed in conjunction with the 31P-MRS study. During the neonatal period, exponential increases in PCr, Pi, and phophodiesters preceded neurological changes. Phosphomonoesters showed an exponential, nearly linear, decrease and PCr/Pi was maintained during the 3-month period. Developmental increases in high energy phosphates and the maintenance of PCr/Pi indicate that the increased energy demands of the developing animal are met by increased mitochondrial function (ATP turnover).

Aging↗
PubMed1990

Microtiter plate assay for the measurement of glutathione and glutathione disulfide in large numbers of biological samples.

By combining the least complicated and expedient methods of sample handling with the sensitivity and specificity of the GSH assay by enzymatic recycling and the small volumes and software capabilities of microtiter plate technology we have devised a rapid, sensitive, and easy assay for GSH and GSSG in biological samples. The assay is sensitive to 5 pmol in sample volumes of 50 microliters, although other volumes could be used. The use of a computer-driven microplate with software capable of linear kinetic data storage and analysis on each well, Maxline series microplate readers and Softmax software, enables the user not only to assay large numbers of samples per day but also to have immediate calculated results. We suggest by examples that measurements of total GSH as well as changes in GSH:GSSG in vitro and in vivo are feasible with this technology.

Animals↗
PubMed1990

Measurement of regional cerebral blood flow in cat brain using intracarotid 2H2O and 2H NMR imaging.

Cerebral blood flow (CBF) was measured in cat brain in vivo at 2.7 T using 2H NMR to monitor the washout of deuterated saline injected into both carotid arteries via the lingual arteries. In anesthetized cats, global CBF varied directly with PaCO2 over a range of 20-50 mm Hg, and the corresponding global CBF values ranged from 25 to 125 ml.100 g-1.min-1. Regional CBF was measured in a 1-cm axial section of cat brain using intracarotid deuterated saline and gradient-echo 2H NMR imaging. Blood flow images with a maximum pixel resolution of 0.3 x 0.3 x 1.0 cm were generated from the deuterium signal washout at each pixel. Image derived values for CBF agreed well with other determinations, and decreased significantly with hypocapnia.

Animals↗
PubMed1990

Clostridium perfringens type C in bloody and watery diarrhea in Bangladesh.

A two-week age-matched case-control survey to detect Clostridium perfringens type C-associated illness was conducted among diarrheal patients hospitalized following the consumption of high protein meals on the occasion of an annual religious festival. From the stool of 33 patients screened, C. perfringens type C was isolated from one patient with bloody diarrhea and from two patients with watery diarrhea. In Bangladesh, C. perfringens type C has been isolated in both bloody and watery diarrhoeal illness and is not necessarily associated with necrotizing enteritis (pigbel).

Bangladesh↗
PubMed1989

Use of monoclonal antibodies to type Shigella flexneri in Bangladesh.

A panel of 10 mouse and rat monoclonal antibodies specific for different type- and group-specific O-antigenic determinants of Shigella flexneri lipopolysaccharide was used to serotype 240 isolates of S. flexneri from Bangladesh. Three immunoglobulin M antibodies were used in a direct slide agglutination test; seven immunoglobulin G antibodies were absorbed to Staphylococcus aureus and used in a coagglutination assay. All but 13 of the isolates could be serotyped by using the monclonal antibodies. The six most common serotypes were (in descending order) 2a, 2b, Y (E1037), 1a, 3a, and 1b and accounted for more than 80% of all isolates. Two of the nontypable strains were found to be of a new provisional serotype of S. flexneri (T. Wehler and N.I.A. Carlin, Eur. J. Biochem. 176:471-476, 1988). The 11 remaining strains were found to be rough and therefore nontypable. The serotyping scheme based on the panel of monoclonal antibodies is specific and holds the potential to be developed into a useful tool for epidemiological investigation. The study also demonstrates that the recently described E1037 antigen is commonly found among at least four serotypes (4a, 6, X, and Y) of S. flexneri.

Agglutination Tests↗
PubMed1988

Studies on the factors affecting the haemolysin production of Vibrio mimicus isolated from clinical and environmental sources.

The in vitro production of haemolysin by Vibrio mimicus, a newly described aetiological agent for human diarrhoea, was determined using sheep erythrocytes. The effects of medium composition and sodium chloride concentration on haemolysin production and its heat stability were investigated. The haemolysin was produced optimally in brain-heart infusion broth and was unaffected by salt concentration up to 1.5%. However, haemolysin production decreased gradually with increasing concentrations of salt above 1.5%, with no production at 5% NaCl. Haemolytic activity was completely lost when culture supernatants were heated at 56 degrees C for 30 min. In general, clinical strains were more haemolytic than environmental strains. The assay system described is simple and rapid, and can be used to study the pathogenic potential of V. mimicus and other noncholera vibrio strains.

DNA↗
PubMed1988

Immunobiological relationships between Vibrio fluvialis and Vibrio cholerae enterotoxins.

A total of 26 strains of Vibrio fluvialis was included in this study, which were isolated from patients with diarrhoea and other sources. The GM1 enzyme linked immunosorbent assays performed with the culture filtrates of V. fluvialis yielded negative results, indicating that their receptor site is different from that of the known labile toxin. The cholera antitoxin failed to neutralize the skin permeability factor activities of all the V. fluvialis culture filtrates and none of the concentrated culture filtrates gave any precipitin band, when tested against the cholera antitoxin in Ouchterlony's gel diffusion test. These observations suggest that the toxin of V. fluvialis differs from the known cholera toxin in receptor site, mode of action and antigenicity.

Cholera Toxin↗