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M S Khan

Publications and source records attributed to M S Khan.

At least 55 records · Page 3Linked to original sources
PubMed1998

Evaluation and comparison of two immunodiagnostic assays for Helicobacter pylori antibodies with culture results.

Several commercially available serological kits have been used as an alternative to endoscopy for the diagnosis of Helicobacter pylori infection. We evaluated the performance of two such kits, Serion H. pylori immunotab kit (Serion, Wurzberg, West Germany) and Pyloragen H. pylori test kit (Hypcor Biomedical Inc., Irvine, CA). Gastric biopsy and serum samples were collected from 345 consecutive dyspeptic patients. The culture and or direct smear of the biopsy was positive for H. pylori in 228 patients (66%), whereas 117 patients (34%) were found to be H. pylori negative. We determined the serological response of the patients using the two kits, both of which are based on the principle of enzyme-linked immunosorbent assay. Comparing the serum immunoglobin G (IgG) and IgA (in a limited number of cases) responses to H. pylori status, the sensitivity, the specificity, positive predictive value, and negative predictive value were calculated. The corresponding data for the different tests were 64%, 79%, 84%, and 56% for Serion IgC, 32%, 94%, 88%, and 52% for Serion IgA, and 88%, 17%, 62%, and 46% for Pyloragen IgG, respectively. We conclude that there is a poor correlation between the presence of H. pylori infection and the antibody response, which could be explained either because of low sensitivities and specificities of the commercial kits used for the measurement of antibodies to H. pylori in the serum or because of poor immunological response in our patients to H. pylori antigens.

Adolescent↗
PubMed1998

An evaluation of pharmacokinetics and pharmacodynamics of leuprorelin acetate 3M-depot in patients with advanced and metastatic carcinoma of the prostate.

OBJECTIVES: The investigational objectives of this open, noncomparative phase I study were to determine the pharmacokinetic profile of a single dose of 11.25 mg leuprorelin acetate, the effective duration of the chemical castration (serum testosterone < or = 1.73 nmol/l) and safety in patients with locally advanced and/or metastatic carcinoma of the prostate foreseen for chemical castration, in the hope that such a dose of leuprorelin acetate may be suitable as a depot formulation to be administered 3-monthly to these patients. METHODS: A total of 24 males up to 85 years old with histologically proven advanced carcinoma of the prostate were enrolled in the study to obtain 18 eligible patients. Each patient was given 11.25 mg of leuprorelin acetate in a depot formulation subcutaneously after reconstitution in 2 ml of a special suspension vehicle. The study period lasted 24 weeks. Patients whose serum testosterone levels reincreased prior to the end of the observation period of 24 weeks were withdrawn from the study and received the monthly depot formulation of 3.75 mg of leuprorelin acetate. RESULTS: The 3M-depot formulation of leuprorelin acetate ensured continuous and constant drug release and effective suppression of testosterone serum levels to castration range for at least 13 weeks. After an initial rise, 5 alpha-dihydrotestosterone as well as the gonadotropin serum levels of luteinizing hormone and follicular stimulating hormone reflected the testosterone serum pattern. CONCLUSION: The results of this study show that the 3M-depot preparation of leuprorelin acetate is effective in suppressing the serum testosterone levels to the castration range for a targeted period of at least 13 weeks.

Adult↗
PubMed1997

Chronic aluminum intoxication in rats: dose-dependent morphological changes.

The objective of the study was to evaluate the chronic cytotoxic effect of very low nontoxic aluminum (Al) in the drinking water of rats. The control group (10 rats) received deionized water, whereas the two experimental groups (10 rats each) received Al in a dose of 5 mg and 20 mg/kg bw/day, respectively. Al was applied in their drinking water during the 6-month duration of the study. Light and electron microscopy (EM) was performed on several body tissues (i.e., kidney, liver muscle, brain). The results showed distinct dose-dependent changes in kidney and brain. In tubulo-interstitial part of the kidney many proximal tubules were hyperdilated. Their cells were swollen and the microvilli were largely lost. Atrophy of some tubules, surrounded by focal areas of interstitial fibrosis was also observed. Some of the glomeruli were undergoing partial sclerosis and in many focal mesangial hypercellularity was found. No distinct morphological changes in other peripheral tissues were observed. In brain, most pronounced changes were observed in hippocampus: they include spongioform changes in pyramidal layer, nuclear deformity and presence of vaculoes in the nuclei. Neurofibrillary degeneration, similar to neurofibrillary tangles in Alzheimer's disease, was also observed. It can thus be concluded that despite very low gastrointestinal absorption (less than 1%), Al in drinking water might accumulate in the long term in vital organs such as kidney and brain, with distinct cytotoxic and neurotoxic effects.

Aluminum↗
PubMed1996

Effects of age on milk yield: time trends and method of adjustment.

Multiplicative adjustment factors for age that were used in the US from 1974 through 1994 were developed from performance records of the 1960s. Rapid genetic improvement and improved management may have altered the relationship between lactation yield and calving age. The purpose of this study was 1) to examine changes in age effects on lactation milk yield over time; 2) to compare multiplicative, additive, or a combined method to adjust records for calving age; and 3) to examine effect of adjustment method on estimates of genetic trend. Data were complete lactation records (n = 765,413) of 383,011 Holsteins from Wisconsin DHI. An animal model was used with fixed effects for herd-year and month of calving by period by age-lactation class and with random effects for EBV, permanent environment, and error. Correction factors were applied additively, multiplicatively, and in combinations. The combination of additive and multiplicative adjustments that minimized heterogeneity of standard deviations within age class was considered to be optimal. The increase in yield that was associated with advancing age and lactation number was greater during recent years than during earlier years. Heterogeneity of standard deviations within age class was nearly minimum with additive adjustment for lactations 1 to 3. For lactations 4 and 5, heterogeneity was not sensitive to method of adjustment; however, multiplicative adjustment was near the optimum. The genetic trend from records with multiplicative adjustment was substantially greater than additive and optimal adjustments, especially during recent years.

Aging↗
PubMed1995

The effect of extracts of the roots of the stinging nettle (Urtica dioica) on the interaction of SHBG with its receptor on human prostatic membranes.

Extracts from the roots of the stinging nettle (Urtica dioica) are used in the treatment of benign prostatic hyperplasia. The mechanisms underlying this treatment have not been elucidated. We set out to determine whether specific extracts from U. dioica had the ability to modulate the binding of sex hormone-binding globulin to its receptor on human prostatic membranes. Four substances contained in U. dioica were examined: an aqueous extract; an alcoholic extract; U. dioica agglutinin, and stigmasta-4-en-3-one. Of these, only the aqueous extract was active. It inhibited the binding of 125I-SHBG to its receptor. The inhibition was dose related, starting at about 0.6 mg/ml and completely inhibited binding at 10 mg/ml.

Cell Membrane↗
PubMed1995

The Bradford and Airedale baby hearing project. An assessment of the impact of screening on the earlier detection of infant hearing loss.

An infant screening programme based on auditory brain stem response testing (ABR) to detect hearing loss in high-risk babies has been introduced in West Yorkshire. In the 3 year period prior to the introduction of the screen hearing loss was diagnosed by the age of 9 months in only 12%. This increased to 85% for children screened by a high-risk register and ABR.

Evoked Potentials, Auditory, Brain Stem↗
PubMed1995

5 alpha-Androstan-3 alpha,17 beta-diol is a hormone: stimulation of cAMP accumulation in human and dog prostate.

5 alpha-Androstan-3 alpha, 17 beta-diol (3 alpha-diol) is a well known metabolite of dihydrostestosterone (DHT) and the concentration of its glucuronide in serum is looked upon as a marker of DHT activity in skin and prostate. The data in this communication show that 3 alpha-diol is a potent agonist of the human and canine prostatic SHBG-[SHBG receptor]. It causes a robust rise in intracellular cAMP within minutes; the 1/2 max. response occurs at a concentration equal to its concentration in male plasma. Estradiol is the only other agonist in this system. All other steroids that bind to SHBG are antagonists.

Androstane-3,17-diol↗