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Biomedical subjects

L A Khan

Publications and source records attributed to L A Khan.

At least 19 recordsLinked to original sources
PubMed2005

Hydrogen peroxide production by Mycoplasma bovis and Mycoplasma agalactiae and effect of in vitro passage on a Mycoplasma bovis strain producing high levels of H2O2.

Hydrogen peroxide (H2O2) production and oxygen uptake during the oxidation of NADH and L-alpha-glycerophosphate (GP) by lysed cells was determined for the type and field strains of Mycoplasma bovis and M. agalactiae. NADH oxidation by all the strains showed variable production of H2O2 ranging from 0 to 1.21 mol/mol O2 taken up. All strains were unable to oxidize GP, showing absence of GP oxidase activity. Some strains were identified that produced relatively high levels of H2O2 (> 1.0 mol/ mol O2 taken up). In vitro passage of M. bovis strain 119B96 showed reduced H2O2 production: 0.52, 0.16, and 0.07 mol/mol O2 taken up after the 50th, 100th and 200th passages, respectively. SDS-PAGE analysis showed the loss of a protein band of 32 kDa after 50 passages. These preliminary studies show that not only does H2O2 production by potentially pathogenic Mycoplasma spp. vary in the field but also that similar alterations can be induced by passage in culture. In the latter case, at least in one M. bovis strain, this alteration has been shown by SDS-PAGE to be associated with a loss of specific protein production. Further study of these phenomena is essential background for the production of more efficient vaccines for mycoplasmas.

Animals↗
PubMed2004

Serum profiles of luteinizing hormone, oestradiol and cholesterol and ovarian functions in layer poultry birds (Gallus domesticus) fed diets containing furazolidone.

This study was carried out to assess the serum profiles of luteinizing hormone (LH), oestradiol, cholesterol and ovarian functions in layer poultry birds (Rhode Island Red: Gallus domesticus) fed a diet containing various concentrations of furazolidone (FZ). A total of 40 birds were randomly assigned to receive FZ 0, 200, 400 or 800 mg/kg feed (ppm) daily during the pre-laying age, i.e. 13-18 weeks (for 5 weeks). Blood samples were collected at weekly intervals. Concentrations of LH and oestradiol in serum were estimated at alternate weeks using radioimmunoassays. Serum cholesterol levels were analysed by an enzymatic calorimetric method. Furazolidone administration was terminated at the 18th week of age. The birds were sacrificed at 22nd week of age and ovarian tissues were processed for morphometric studies. Serum LH, oestradiol and cholesterol levels were affected by age (p < 0.001) and FZ dose (p < 0.001). Serum LH and oestradiol levels were lower (p < 0.05) in birds receiving FZ 800 mg/kg feed daily compared with the controls, whereas serum cholesterol profiles were lower (p < 0.05) in all FZ-administered groups than in the control group. The mean weight of ovaries having no yolky follicles observed in the group receiving FZ 400 or 800 mg/kg feed per day was reduced (p < 0.05) compared with the control group. Dosing FZ at 800 mg/kg feed per day reduced (p < 0.05) the mean volume of ovaries having no yolky follicles compared with the control group. In birds receiving FZ 800 mg/kg feed per day, the mean length of the oviduct was reduced (p < 0.05) as compared with the control group. Morphometric studies revealed that the mean number of oocytes with diameter in the range 401-800 microm decreased (p < 0.05) in birds fed FZ 400 or 800 mg/kg feed per day. Initial egg production was affected by age (p < 0.001) and dose (p < 0.001) of FZ. The mean number of eggs laid by different groups revealed that egg production was reduced (p < 0.05) in birds receiving FZ 800 mg/kg feed per day as compared with the controls. The present data suggest that FZ causes suppression in serum profiles of LH, oestradiol, cholesterol and ovarian functions in Rhode Island Red layer poultry birds. Therefore, great care must be taken with use of FZ in layer poultry birds (Gallius domesticus) with regard to dosage and duration of administration.

Animals↗
PubMed2001

Medical surfing.

The Internet has revolutionized information technology. Vast amounts of latest information are available on the Internet to medical professionals. Medical surfing is fast becoming part of a doctor's profession. But the way to approach the Internet and retrieve useful information from myriads of medical websites seems a daunting task to many. This review aims to help the newcomer, the medical students and doctors in obtaining fruitful medical information while surfing. It will prevent them from the feeling of getting drowned in the ocean of medical information. As medical information is not restricted to books and journals, providing Internet addresses of different medical bodies with few salient features, will go a long way in helping attain the required information without wasting time. The Internet will soon become a universal library. Medical surfing should be included in the curriculum of all medical schools and universities.

Education, Medical, Continuing↗
PubMed2000

Adult Kawasaki disease.

Kawasaki disease was first described from Japan in 1967. Most of the patients reported have been under 3 years of age. We are reporting a typical case of Kawasaki disease in an adult Yemeni male, who had all criteria for diagnosis. Additionally our patient had tricuspid regurgitation as well as tricuspid valve endocarditis, which is only rarely reported in literature. We also noted a rise in monocyte and eosinophil count up to 10%, which may have pathophysiologic significance in this disease. At two year follow up our patient had persistent right bundle branch black which he had developed during the course of his illness. Mortality of the disease is related to cardiac complications especially coronary arteritis and aneurysms in children. In adults too once diagnosis is established patients should be followed for a long period of time to look for any possible cardiac complications.

Adult↗
PubMed1999

Serum and urinary magnesium in young diabetic subjects in Bangladesh.

BACKGROUND: Magnesium imbalance, implicated in diabetes mellitus both as a cause and a consequence, has not yet been investigated in subgroups of subjects with malnutrition-related diabetes mellitus. which is prevalent in young patients in tropical developing countries such as Bangladesh. OBJECTIVE: The present study evaluated the serum and urinary magnesium concentrations in groups of young diabetic subjects in Bangladesh. DESIGN: Forty patients newly diagnosed with diabetes [13 with fibrocalculus pancreatic diabetes (FCPD), 13 with protein-deficient diabetes (PDDM), and 14 with type 2 diabetes mellitus] were studied along with 13 healthy control and 13 malnourished control subjects [body mass index (in kg/m2) < 19]. Magnesium was measured by atomic absorption spectrophotometry. RESULTS: Malnutrition itself was not related to the serum glucose (fasting: 3.68+/-0.74 and 4.11+/-0.29 mmol/L; postprandial: 6.30+/-0.41 and 6.00+/-0.24 mmol/L for healthy and malnourished control subjects, respectively) or serum or urinary magnesium (serum: 0.73+/-0.03 and 0.75+/-0.05 mmol/L: urinary: 232+/-124 and 243+/-88 mmol Mg/mol creatinine for healthy and malnourished control subjects, respectively) concentration. Subjects with FCPD and PDDM had significantly lower serum magnesium concentrations (PDDM: 0.68+/-0.06 mmol/L, FCPD: 0.66+/-0.07 mmol/L) than those in both control groups. In contrast with 0% of healthy and 7.7% of malnourished control subjects, 42.85% of type 2 diabetic subjects, 61.54% of those with PDDM, and 69.23% of those with FCPD were hypomagnesemic. Subjects with FCPD and PDDM had significantly higher urinary excretion of magnesium than the healthy and malnourished control subjects and the type 2 diabetic subjects. Hypermagnesuria paralleled hypomagnesemia. CONCLUSIONS: Malnutrition may not itself give rise to glucose intolerance, and serum magnesium deficiency seems to be a consequence rather than a cause of diabetes mellitus.

Adolescent↗
PubMed1999

Pre-steady state kinetic studies on H(+)-ATPase from Candida albicans.

The mechanism of ATP hydrolysis by plasma membrane H(+)-ATPase from Candida albicans has been investigated by following the kinetics of H(+) liberation/absorption and the UV difference spectrum in a stopped flow spectrophotometer. A distinct pre-steady state phase of ATP hydrolysis could be defined. While the rapid mixing of P(i) and ATPase produced no transient pH changes, the mixing of ADP leads to the release of 1 H(+) per molecule of ATPase. Rapid mixing of ATP with ATPase releases about 2 H(+) per molecule of ATPase, of which around 1.3 H(+) are reabsorbed. The magnitudes of both H(+) release and absorption were found to be independent of ATP concentration. The rate of H(+) release (k(f)) shows ATP dependence while the rate of H(+) absorption is independent of ATP concentration. The rate of H(+) liberation with ADP, on a concentration basis, was far less as compared with ATP, indicating a low affinity of the ATPase for ADP. No change in the difference spectrum was observed with ADP. The stoichiometry of ATP binding to PM-ATPase was found to be unity from UV-difference spectrum studies. The k(f) values for H(+) release and for the appearance of a difference spectrum following the addition of ATP were found to be similar beyond a 1:1 ratio of ATP:ATPase. The results obtained lead us to propose a 4-step kinetic scheme for the mechanism of ATP hydrolysis.

Adenosine Diphosphate↗
PubMed1994

The scope and place of ultrasound-monitored extracorporeal shock wave lithotripsy in a multimodality setting and the effects of experiential, audit-evoked changes on the management of ureteric calculi.

OBJECTIVE: To assess the results from ultrasound-monitored extracorporeal shock wave lithotripsy (ESWL) for ureteric stones, to compare the results with other treatment modalities and to evaluate experiential audit-evoked gains. PATIENTS AND METHODS: A review of the records of 109 patients with ureteric stones who were treated during 1990 (Group I) and 69 patients treated by ESWL during the first 10 months of 1991 (Group II), was carried out. All patients with a steinstrasse or fragments secondary to ESWL were excluded from the study. RESULTS: Of the 109 patients in Group I, 63 were treated with ESWL, nine underwent ureteroscopic push-up of the stone and 11 underwent catheter push-up prior to ESWL, 28 underwent ureteroscopic extraction/fragmentation, five underwent post-ESWL ureteroscopy and 29 underwent open ureterolithotomy (nine after failed ureteroscopy). Ureteroscopy was successful in fragmentation/extraction of 19 of 28 (68%) stones and 95% of patients were stone-free at 3 months. All patients who underwent ureterolithotomy and 84% who underwent ESWL (and post-ESWL ancillary procedures) were stone-free at 3 months. All patients who underwent ureterolithotomy, 51% of those who underwent ureteroscopy and 56% of patients who underwent ESWL needed only one treatment. The mean stone burdens of patients in Groups I and II were comparable but more patients presented with larger stones (> 15 mm length, > 100 mm2 surface area) in Group II. The stone-free rates for ESWL monotherapy with ESWL increased from 84% in 1990 to 92% in 1991. A higher proportion of stones were treated in situ in 1991 and a stent was used less frequently in obstructed ureters. Post-ESWL procedures fell from 8% in 1990 to 6% in 1991 and the proportion of patients who required more than one treatment fell from 44% in 1990 to 14% in 1991. CONCLUSIONS: The choice of treatment for patients with ureteric stones is critical but will vary depending on the individual's circumstances, the availability of equipment, costs and time required to perform the procedure. The results obtained using ESWL for ureteric stones improved considerably over the course of the study as a result of experience and refinement of the technique. Stones located in more difficult systems such as in kidneys with a thin cortex and those located above the ischial spine were no longer subjected to ESWL. Audit of the results obtained following treatment allows identification of problem areas, alerts physicians to alternative methods of treatment and gives an objective quantification of experience, assisting rational decision making with consequent improved success.

Adult↗