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Biomedical subjects

I H Khan

Publications and source records attributed to I H Khan.

At least 19 recordsLinked to original sources
PubMed1992

The cytoplasmic component of the bacterial flagellar motor.

We have used electron microscopy to examine freshly isolated Salmonella typhimurium and Escherichia coli basal flagellar fragments, purified without resort to extremes of pH or ionic strength. Such fragments contain the large bell-like basal structures visualized recently in freeze-substituted or fixed preparations. We have found mot (non-motile) mutants produced by lesions in fli genes (G, M, N) in which the bell structures do not coisolate with the flagellar basal body. The coisolation of the bell with the flagellar basal body was unaffected in strains lacking the genes for the motility-associated Mot proteins or for the Che family of proteins, which are necessary for chemotaxis. Proper assembly and interaction of the cytoplasmically located bell with the membrane-associated flagellar basal structures appears to be necessary for motor function. The FliG, FliM, and FliN proteins are thought to form a structural complex responsible for energization and switching of the flagellar motor. Our findings are consistent with the existence of such a complex and imply that it forms part of the flagellar bell.

Cell Fractionation↗
PubMed1992

Advance directives.

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Advance Directives↗
PubMed1992

Hyperpyrexia due to meningococcal septicaemia treated with cold peritoneal lavage.

An 18 year old male presented with fulminant meningococcal septicaemia and renal failure. He subsequently developed hyperpyrexia which failed to respond to conventional methods of treatment. Cold peritoneal lavage was employed which resulted in rapid lowering of his core temperature and helped manage his renal failure. The possible causes of the late onset of hyperpyrexia and the use of cold peritoneal lavage to treat refractory hyperpyrexia are discussed.

Acute Kidney Injury↗
PubMed1991

New structural features of the flagellar base in Salmonella typhimurium revealed by rapid-freeze electron microscopy.

The structure of the flagellar base in Salmonella typhimurium has been studied by rapid-freeze techniques. Freeze-substituted thin sections and freeze-etched replicas of cell envelope preparations have provided complementary information about the flagellar base. The flagellar base has a bell-shaped extension reaching as far as 50 nm into the bacterial cytoplasm. This structure can be recognized in intact bacteria but was studied in detail in cell envelopes, where some flagella lacking parts of the bell were helpful in understanding its substructure. Structural relationships may be inferred between this cytoplasmic component of the flagellum and the recently described flagellar intramembrane particle rings as well as the structures associated with the basal body in isolated, chemically fixed flagella.

Flagella↗
PubMed1991

High vaginal swab(HVS), routine microscopy and culture sensitivity in diabetic and non diabetic, a comparative retrospective study of five years.

Diabetic women are significantly more prone to develop vaginitis (both bacterial and fungal) than non diabetic. Among the positive cases predominant bacterial isolate being E. Coli. All fungus positive culture yielded the growth of candida species. Direct wet film preparation of the fungus positive cases revealed only 30% were positive for fungus, thus if candida vaginitis is suspected, the diagnosis cannot be ruled out on the basis of negative direct preparation. More over, diabetics should be advised maintain proper glycaemic control and personal hygiene to get rid of this distressing problem.

Bacteria↗
PubMed1990

Study of environmental pollutants in and around the city of Lahore. I. Determination of lead in blood of various population groups.

Lead concentrations in 102 blood samples collected from seven different population groups living in and around the city of Lahore were determined. Gender differences in blood lead were statistically insignificant for normal males and normal females and also for male and female cancer patients. The differences between exposed male industrial workers and exposed females were statistically significant (P = 0.05). No correlation was observed between age and blood lead for normal males and cancer patients of both sexes. Blood lead levels in the male groups were generally higher than in the corresponding female groups. Much higher blood lead concentrations for cancer patients of both sexes, i.e. 69.63 microgram dl-1 for males and 52.41 microgram dl-1 for females, were observed.

Age Factors↗
PubMed1988

Post mortem studies on infertile buffalo bulls: testicular histology.

Testicular tissues of 22 buffalo bulls (Bubalus bubalis) which suffered from three types of infertility were examined histologically. Nine bulls with no sexual libido showed underdeveloped seminiferous tubules; five of them also had various forms of germinal tissue hypoplasia (bilaterally complete, partial or incomplete) and in the other four the seminiferous tubules showed developed layers of germinal epithelium but no complete spermiogenesis. Among 11 bulls which had always produced poor quality semen one suffered from incomplete bilateral testicular hypoplasia and two had simple testicular degeneration; five showed marked testicular degeneration associated with fibrosis of intertubular spaces, and in three there was intertubular fibrosis and tubular stasis. In two bulls in which the quality of semen had deteriorated one showed bilateral partial testicular hypoplasia and the other had bilateral testicular degeneration with unilateral intertubular fibrosis and tubular stasis.

Animals↗
PubMed1985

Post mortem studies on infertile buffalo bulls: anatomical and microbiological findings.

Twenty-two buffalo bulls suffering from three different types of infertility were slaughtered and used for this study. Except for the reproductive system, no signs of localised or generalised disease were observed. Microbiological investigations were negative for brucellosis, vibriosis, mycoplasma and other non-specific microorganisms. Nine bulls with type 1 infertility had low bodyweights and underdevelopment of testes, accessory sex glands and endocrine glands. This picture suggests a total dysfunction of the pituitary-growth-gonadal axis. One bull of this type also showed bilateral epididymitis. Four out of 11 bulls with type 2 infertility had low bodyweights and most suffered from underdevelopment of testes, accessory sex glands and endocrine glands. Six bulls of this type had lesions of either epididymitis or orchitis or both. Two of these animals showed adhesions of periorchitis. One also showed seminal vesiculitis. In two bulls with type 3 infertility, bodyweights, reproductive organs and endocrine glands were normal. In later life, they yielded poor quality semen. Semen samples collected a few months before slaughter from nine bulls with type 2 and type 3 infertility were of poor quality and had higher percentages of abnormal spermatozoa in most cases.

Adrenal Glands↗
PubMed1976

Nutritional status of children in Nepal, 1975.

Using a random start, fixed interval method of population proportionate sampling, the survey teams visited 219 villages in rural Nepal and collected data on height, weight, and age from 6501 preschool children. During training and at specific times during the survey, systematic standardization methods were utilized to improve the quality of the collected data. Using 80% of the reference median weight-for-height as the cut-off point, the prevalence of acute undernutrition was 6.7%. Using 90% of the reference median height-for-age as the cut-off point, the prevalence of chronic undernutrition was 52%. The prevalence of chronic undernutrition was significantly higher in the hilly areas. Mean haemoglobin values of blood samples collected from one-fifth of the survey population increased with age with no difference between hill and terai areas. A Nepal urban elite population was measured for comparison. The survey method used indicators that are economical in terms of money, time, and personnel and that provide objective data on the extent and distribution of protein/energy undernutrition and of low haemoglobin values in preschool children.

Body Height↗