PubMed Health⌕ Search

Biomedical subjects

A A Ismail

Publications and source records attributed to A A Ismail.

At least 91 records · Page 5Linked to original sources
PubMed1984

Factorial design of experiment for stability studies in the development of a tablet formulation.

The stability of chlorpromazine hydrochloride in some hypothetical tablet formulations was evaluated through a fractional factorial design of the type N = 2(6-3). The factors studied were the type of filler (X1), lubricant (X2), binder (X3), disintegrant (X4), the absence or presence of light ( X5 ) and/or humidity ( X6 ). Statistical analysis of the stability data allowed the derivation of a regression equation which determined the magnitude and direction of change of each factor level to optimize drug stability. The significance of the factors could be arranged in the following order: X5 greater than X2 greater than X3 greater than X6 greater than X1. The effects of X4 and the two-factor interaction X2X3 were found to be insignificant. The best multi-component excipient mixture was evaluated on the basis of the information deduced from the factorial design.

Analysis of Variance↗
PubMed1983

Cytofluorescence localization of adriamycin-binding sites of cardiac tissue.

A study of the cardiotoxicity induced by adriamycin (ADR) was done on the heart tissue of Sprague-Dawley rats receiving a single intravenous dose (15 mg/kg). Condensed bright orange-red fluoresced chromatin was observed in the nuclei of the myocardial cells of the left ventricle 2 h after drug injection. Just then, the intensity of the fluorescence emission started to decrease until it reached its minimum after 21 days, and disappeared completely 28 days after drug injection.

Animals↗
PubMed1983

Immunoperoxidase localization of catechol-o-methyl transferase (COMT) in human breast cancer.

Immunoperoxidase reaction of appropriately fixed tissue with an antiserum to catechol-o-methyl transferase (COMT), as the primary step in the peroxidase-immunoglobulin bridge technique, has been utilized for the localization of COMT in biopsy specimens of human breast neoplasm and its metastases. Our immunocytochemical identification of a strong activity of COMT in all cases studied might have a diagnostic implication in breast cancer.

Breast↗
PubMed1983

Oestrogen-induced renal carcinogenesis in the hamster: ultrastructural and hormonal studies of the pars intermedia before and after withdrawal of oestrogen.

Long-term oestrogen treatment of male hamster induced renal carcinoma and pituitary enlargement due to hypertrophic and hyperplastic change in the pars intermedia. The latter effect was accompanied by ultrastructural abnormalities in pars intermedia cells and elevation of serum MSH concentration. Oestrogen treatment was stopped after 36 weeks and animals were killed at intervals from 8 to 36 weeks after oestrogen withdrawal. Nearly complete tumour regression occurred during the 36 weeks following cessation of oestrogen and by 28...36 weeks the pars intermedia cells regained normal ultrastructural appearance. However, pituitary enlargement and elevated serum MSH levels persisted throughout the post oestrogen recovery period.

Animals↗
PubMed1983

Effect of some selected salts and non-ionic surfactants on the antimicrobial activity of nalidixic acid.

The effect of different concentrations of some selected salts, namely, sodium chloride, potassium chloride, ammonium chloride, monosodium dihydrogen phosphate, calcium chloride, dibasic sodium phosphate, sodium sulphate, aluminium chloride and sodium citrate on the antimicrobial activity of nalidixic acid was investigated. It was found that all the salts tested, except aluminium chloride and sodium citrate, exert no antimicrobial activity. The effect of 10% non-ionic surface active agents, namely, Myrj 51, 52, 59, Brij 35, 58, 98, Tween 20, 40, 60, and 80 on the antimicrobial activity of nalidixic acid was studied. The results indicated that the activity of nalidixic acid was decreased in the presence of these surfactants. Furthermore, the effect of different concentrations of sodium chloride on the antimicrobial activity of nalidixic acid-surfactants systems was reported.

Bacteria↗
PubMed1982

An automated procedure for the determination of oxytetracycline.

An automated analytical system has been used to determine the amount of oxytetracycline in pharmaceutical products and fermentation broth at a level of 0.1 mg/mL. The method is based on the formation of a colour complex between the oxytetracycline and ammonium molybdate in acid media at 80 degrees C. The effect of temperature, concentration of HCl and ammonium molybdate upon the stability of the complex was determined. Standard error of difference is 0.43% for pharmaceutical products and the fermentation broth.

Colorimetry↗
PubMed1982

The value of a single serum progesterone measurement in the midluteal phase as a criterion of a potentially fertile cycle ("ovulation") derived form treated and untreated conception cycles.

A single midluteal serum progesterone concentration was obtained in 212 untreated cycles in 113 infertile patients, including 138 cycles in 72 patients in whom tubal, seminal, and cervical causes of infertility had been excluded. There were 16 conception cycles in the latter group. In an extended study a total of 21 untreated singleton conception cycles have been observed with a mean progesterone value of 40.7 nmol/l (12.8 ng/ml), 95% confidence limits of 28 to 53 nmol/l (8.8 to 16.7 ng/ml), and a range of 27 to 53 nmol/l (8.5 to 16.7 ng/ml), which extended significantly above as well as below the conception range, indicating that there is an optimal range for fertility with both an upper and a lower limit. The lower limit is of greater practical importance; and, partly to allow for assay variation, we suggest it should be taken as 30 nmol/l (9.4 ng/ml). It provided a clinically reliable criterion of potential fertility ("ovulation") in related studies. Our findings in treated conception cycles suggest that a higher value may be needed after treatment with clomiphene or gonadotropins because of the contribution from other stimulated follicles.

Adult↗
PubMed1982

Cytofluorescence evidence of adriamycin in liver.

Fluorescence study was carried out in Sprague-Dawley rats injected intravenously with the anti-cancer drug adriamycin (ADR) at a dose of 15 mg/kg to determine the site of its localization in liver. Significant fluorescence emission of ADR nuclear-binding appeared in the liver shortly after the drug administration. The occurrence of the nuclear fluorescence in our material was explained by the binding of ADR to DNA. The cytoplasmic drug loading of liver cells might reflect their role in the drug metabolism.

Animals↗
PubMed1981

An improved fully automated continuous-flow system for immunoassays.

A modification to the Southmead continuous-flow automated immunoassay system enables the bound ligand fraction to be quantitated. The bound fraction is sequentially collected, washed, and then eluted from the separating device as a bolus. The misclassification error at separation is of the order of 0.6%, and sample-to-sample interaction is negligible. The application of the modified system to the radioimmunoassay for thyroxine at a rate of 60 samples per hour is described, and satisfactory assay characteristics and performance are documented. The application of the Southmead system to the enzyme immunoassay of thyroxine and to assays for other ligands is discussed.

Humans↗
PubMed1981

Comparative dissolution rate studies of commercial furosemide tablets.

Five commercial brands of furosemide tablets from different manufacturers, namely, S, F, Ls, L and Fr were elected for this study. The dissolution rate studies of these brands demonstrated vast differences in drug release characteristics. Only two batches of Fr and one batch of F brands fulfilled the U.S.P. dissolution test, while the other failed to meet the requirements of this test. The dissolution rate studies of different batches the same commercial brand showed a larger interlot variation within certain brands. These interlot variations were by far smaller than the dissolution rate differences between the different brands. Studies on the drug content for each furosemide brand showed a great variation between the brands and also within the different batches of the same brand.

Chemistry, Pharmaceutical↗