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Biomedical subjects

M R Khan

Publications and source records attributed to M R Khan.

At least 127 records · Page 7Linked to original sources
PubMed1983

Plasmid-borne multiple drug resistance in Vibrio cholerae serogroup O1, biotype El Tor: evidence for a point-source outbreak in Bangladesh.

In 1979, an outbreak of plasmid-borne, multiply drug-resistant Vibrio cholerae serogroup O1 biotype El Tor (V. cholerae O1) occurred in the Matlab area of Bangladesh. The outbreak could have resulted from the introduction into the area of a single resistant strain or from multiple conjugations of drug-sensitive V. cholerae O1 with C plasmids in other environmental flora. Resistant strains were phage typed to determine their relatedness, and plasmid studies were conducted to determine the frequency of C plasmids in nonvibrio flora of family contacts of cholera patients. Forty-one (85%) of 48 resistant strains of V. cholerae O1 examined belonged to two closely related phage types new to the area, whereas 59 drug-sensitive strains from the same period were primarily of two different phage types. Group C plasmids were in nonvibrio strains from five of 36 family contacts of patients with drug-resistant cholera but none of 82 family contacts of patients with sensitive cholera. This outbreak most likely began from the introduction into the area of a single, multiply drug-resistant strain of V. cholerae O1. C plasmids detected in the nonvibrio flora of family contacts probably came from the resistant strain of V. cholerae O1.

Anti-Bacterial Agents↗
PubMed1983

Phage types of Vibrio cholerae O1 biotype El Tor isolated from patients and family contacts in Bangladesh: epidemiologic implications.

The epidemiology of Vibrio cholerae O1 El Tor in rural Bangladesh was examined with a new phage-typing system for characterization of individual strains. During a two-year period, 537 strains were typed with a set of standard and experimental phages. Four major and many minor patterns were identified, some associated with discrete outbreaks of disease and others persisting for the entire period. One outbreak-related phage type was associated with a C plasmid bearing multiple drug resistance. The yearly cholera seasons began with the emergence of strains of many different phage types in many different locations; this pattern is consistent with an environmental reservoir for V cholerae. Each patient with cholera excreted only one phage type over time, whereas some family members were infected with strains of different phage types. Phage typing can be a useful marker with which the spread of cholera strains can be traced in endemic settings.

Bacteriophage Typing↗
PubMed1983

Partial Purification of Mucor pusillus Intracellular Proteases.

The intracellular protease extracted from the freeze-dried mycelia obtained after the growth of Mucor pusillus at 30 degrees C in corn steep liquor medium was chromatographed on DEAE-A50. Some characteristics of the protease fractions obtained after ion-exchange chromatography were determined and compared with those of the extracellular proteases reported previously. The mycelia were found to contain two acid proteases and an alkaline protease. The ratio of milk clotting to protease activity of one acid protease was greater than that of the other. The electrophoretic pattern of the alkaline protease fraction suggested that it was not a single species, but a mixture of proteolytic enzymes.

Journal Article↗
PubMed1982

Antibiotic use in a rural community in Bangladesh.

Antibiotic use by 175 000 people in the Matlab rural surveillance area (MSA) of the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) was studied to identify practices which might affect microbial drug resistance. We surveyed a 3% sample of drug purchases from pharmacies in the MSA over a four-week period in August and September 1980. Fifty-seven drug purchases were made per thousand Matlab residents per week; 9% of these were of tetracycline and 26% were antibiotics. Forty-eight per cent of the antibiotic tablets or capsules for persons aged 15 years or more were purchased in quantities which represented less than a single day's dose and rarely was a full course of therapy purchased at one time. The rate of tetracycline purchase for young children--in whom it is usually contraindicated--equalled the rate for older children and young adults. These practices have probably not led to improvements in health and may have promoted the emergence and persistence of drug-resistant micro-organisms. To optimize antibiotic use, control measures at government, producer, prescriber and consumer levels need to be pursued.

Adolescent↗
PubMed1982

Study of thyroid functions in protein energy malnutrition.

Thyroid functions were studied in eight children suffering from PEM. The assessment of thyroid functions were done by measuring serum T3 and T4 levels by radioimmunoassay. Both T3 and T4 levels in serum were significantly (P less than 0.001) reduced in PEM as compared to normal healthy children. These results suggest that thyroid functions are affected in PEM. The impairment of such functions may possibly be due to a deficiency of protein or to a blockade in the incorporation of iodine into thyroid hormone at some stage after iodide transport into the gland. The possibility of alteration of some biochemical or metabolic changes induced by PEM during biosynthesis of thyroid hormones cannot be excluded.

Child↗
PubMed1981

The relationship of cholera to water source and use in rural Bangladesh.

The cholera experience of a sample of families in a rural area of Bangladesh is reported in relation to water supply and use. Tanks were the primary source for 65% of families, canals for 20% and the river for 14%. The highest attack rate was associated with access to canal water (13%). Attack rates did not vary markedly according to the purpose for which a source was used. The importance of cultural patterns in water use is identified.

Bangladesh↗
PubMed1979

Extracellular Proteases of Mucor pusillus.

Mucor pusillus was grown in different media for a period of 92 h, and the media were investigated for both milk-clotting and protease activities. It was observed that the ratio of extracellular milk-clotting activity to protease activity was the highest for 3% corn steep liquor containing 1% glucose as the source of carbon. Variation of both milk-clotting and protease activities was studied during the growth of the organism in the medium stated above. Separation of protease was carried out by ion-exchange chromatography at pH 8.0. Fractions collected were assayed for both activities simultaneously. The findings suggested that, instead of only one major acid protease, as reported by previous workers, two major acid proteases were produced. One of them had significant rennin-like activity, and the other lacked it. The former could be assumed to be the enzyme reported and studied by previous workers. The existence of two proteases was further confirmed by the appearance of two protease activity bands on polyacrylamide gels after electrophoresis. An attempt was made to separate the rennin-like enzyme from nonspecific protease activity by ammonium sulfate fractionation followed by ion-exchange chromatography at pH 6.0. The results indicated that the nonspecific protease activity due to the enzyme that lacked rennin action was substantially removed by the ammonium sulfate fractionation.

Journal Article↗
PubMed1978

Birth weight, length, head and chest circumference and haemoglobin level of new born.

The birth weight, length, head and chest circumference and haemoglobin level of 1002 full term new born babies (506 males and 496 females) were determined. The results were compared with similar data from other countries. The birth weight of the present series of newborns were similar to those of newborns from India, the crown-heel length agreed favourably with the data from India and Indonesia, and the head circumference were almost equal to those of the newborns from Sri Lanka, Jamaica and India.

Anthropometry↗
PubMed1976

Cholera transmission near a cholera hospital.

A review of the incidence of cholera from 1964 through 1974 in Matlab, Bangladesh, revealed that among the villages several had very high incidence-rates. Investigation indicated that high cholera-rates in two of these villages were probably related to water contamination from a nearby cholera hospital established in 1963. The data imply that heavy contamination can overcome any immunity resulting from repeated exposure.

Bangladesh↗
PubMed1974

Transthoracic electrical impedance in cases of high-altitude hypoxia.

Changes in transthoracic electrical impedance (T.E.I.) due to high-altitude hypoxia (3,658 m) have been measured in 20 young, healthy Indian soldiers. They were first studied at sea level (198 m) and then rapidly transported by air to 3,658 m, where they were studied daily from day 1 to day 5 and then on days 8 and 10. The mean (+/-S.D.) T.E.I. at sea level (34.6+/-0.6Omega) fell sharply to 29.6+/-0.8Omega, 30.3+/-0.9Omega, and 30.5+/-1.1Omega on days 1, 2, and 3 (P <0.001) and levelled off at 31.5+/-0.7Omega on day 10, which was comparable to the mean value obtained in 13 persons permanently resident at high altitude (32.2+/-0.7Omega). Five sea-level residents who had acute mountain sickness (A.M.S.) or high-altitude pulmonary oedema (H.A.P.O.) had a still lower mean value (22.5+/-1.1Omega). One normal healthy subject who at sea level had a T.E.I. of 34.7Omega developed H.A.P.O. when the T.E.I. fell to 21.1Omega. Ninety minutes after the administration of 80 mg of intravenous frusemide the value increased to 35.5Omega. In another subject with A.M.S. who received 40 mg of frusemide intravenously the T.E.I. rose from 21.9 to 33.2Omega.Since the study was non-invasive the changes in impedance could not be correlated objectively with alterations in either pulmonary blood volume or pulmonary extravascular water space. In the subject, however, with x-ray evidence of H.A.P.O. and a low T.E.I. intravenous frusemide produced a marked rise in T.E.I. together with clearing of the chest x-ray picture within 24 hours, indicating an inverse relationship between impedance and thoracic fluid volume. It is suggested that with further objective verification in man the measurement of T.E.I. may be a potentially promising technique for the early detection of increased pulmonary fluid volume.

Adult↗