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Biomedical subjects

M Ashraf

Publications and source records attributed to M Ashraf.

196 records · Page 11Linked to original sources
PubMed1973

The effect of glucose-insulin-potassium on cardiac ultrastructure following acute experimental coronary occlusion.

The effects of glucose-insulin-potassium (GIK) on cardiac ultrastructure following acute experimental coronary occlusion were studied in dogs. Epicardial ST segment elevations at multiple sites on the anterior surface of the left ventricle 15 minutes after ligation of the left anterior descending coronary artery were used to predict infarct development. Biopsies removed from sites of known ST segment elevation were examined with the electron microscope, and the degree of injury was correlated with the ST segment elevation. The animals receiving GIK showed significantly less necrosis than was seen in dogs with occlusion alone at corresponding levels of ST segment elevation. Other evidence suggesting a beneficial effect of GIK was the presence of a fibrillar material in several biopsies from the treated animals, which may indicate the regeneration of myofilaments.

Animals↗
PubMedDate not supplied

Morphological and smooth muscle cell phenotypic changes in fetal rabbit aorta during early development.

Previous studies from our laboratory noted a) high aortic cholesterol esterification activity in the fetal rabbit, and b) increased susceptibility of fetal aortic explants to smooth muscle cell proliferation in culture, two features commonly associated with atherogenesis. This prompted us to examine in detail morphological development of fetal aorta and its relationship to fetal plasma cholesterol levels. Our studies made three important observations: 1) plasma cholesterol levels were high in early fetus which decreased at term; 2) in early fetus aortic endothelial cells appear to protrude into the lumen, whereas at birth the cells become flat, forming a continuous endothelium sheet; 3) in early fetus, smooth muscle cells exist predominantly in synthetic phenotype, while at birth the cells appear contractile. Despite the presence of synthetic smooth muscle cells and hypercholesterolemia in early fetal life, no accumulation of lipids was evident under transmission electron microscopy.

Animals↗
PubMedDate not supplied

Beneficial effects of low doses of ethanol on reoxygenation injury following anoxia in rat hearts.

We investigated the effect of ethanol on adverse effects of anoxia and reoxygenation in isolated rat hearts. Perfusion of the anoxic Krebs-Henseleit medium for 40 min followed by 30 min of perfusion with aerobic medium produced considerable myocardial cell injury. Incorporation of ethanol (21.7 mM), in both anoxic and aerobic perfusion media resulted in a significant reduction of cell injury and inhibition of creatine phosphokinase release. The contraction bands were reduced to 0.24 as compared to 1.14 per field in the non-treated hearts. The tissue Ca++ was decreased to 8.72 mumol/gm/dry dry wt as compared to 20.17 mumol/gm/dry wt), as compared to the nontreated anoxic tissue (4.41 mumol/gm/dry wt). However, the inclusion of only ethanol in the anoxic medium did not decrease the damage, suggesting that maximal injury occurred during reoxygenation. Ethanol appears to inhibit myofibril contractures and preserve the structural integrity of plasma membrane during anoxia and reoxygenation. This study suggests a beneficial effect of ethanol in low doses on the post anoxic reperfusion injury in the myocardium.

Adenosine Triphosphate↗
PubMedDate not supplied

Retrospective audit of standards and quality in colposcopy services in a district hospital.

A retrospective audit to compare the performance of a colposcopy clinic with the standards set by National Health Service Cervical Screening Programme (NHSCSP) was carried out at Caerphilly District Miners Hospital, South Wales, United Kingdom. The study sample size consisted of 150 women who underwent colposcopy and diathermy large loop excision of the transformation zone (LLETZ) for abnormal cytology during January l995 to January 1998. The results showed deficiencies in the areas of communication for clinic appointments for women with high-grade cytology and in information given to general practitioners about test results. The services fell short of the standards in recording of colposcopy findings and grading of lesions. The rest of the parameters audited reached the NHSCSP standards. Recommendations to improve communication and to increase the objectivity of recording colposcopy findings were made. A more practical approach to set standards in areas of communication was suggested.

Colposcopy↗
PubMedDate not supplied

Activation of mitochondrial K(ATP) channel elicits late preconditioning against myocardial infarction via protein kinase C signaling pathway.

Activation of mitochondrial K(ATP) (mitoK(ATP)) channel induces acute ischemic preconditioning (PC) against ischemic injury. The ability of this channel to elicit late PC remains unknown. The present study tests the hypothesis that stimulation of mitoK(ATP) channel induces late PC via the protein kinase C (PKC) signaling pathway. Rats were subjected to 30 minutes of regional ischemia and 120 minutes of reperfusion (I/R). In other groups, rats were pretreated with diazoxide, a specific opener of the mitoK(ATP) channel (7 mg/kg, IV), 12, 24, 48, and 72 hours before they were subjected to I/R. A maximum reduction in infarct size was observed after 24 hours (33.3+/-2.2% versus I/R group, 62.1 +/-2.4%). Pretreatment with diazoxide did not reduce the infarct size significantly after 12, 48, and 72 hours (50.2+/-4.3%, 50.5+/-4.6%, and 58.2+/-4.9%) compared with the I/R group. The protection was blocked with 5-hydroxydecanoic acid (5-HD, 5 mg/kg IV), a relatively selective mitoK(ATP) channel blocker (56.5+/-2.7%), and chelerythrine (5 mg/kg IV), an effective PKC inhibitor (57.1+/-3.4%) administered either on the first day before diazoxide pretreatment or 10 minutes before I/R on the second day. Cell necrosis was decreased by approximately 50% in the diazoxide preconditioned hearts compared with control I/R hearts. Cell death by apoptosis was also significantly decreased in diazoxide pretreated hearts (3.2%) as compared with I/R (11.3%). In conclusion, activation of mitoK(ATP) channel with diazoxide produces late PC against reperfusion injury. The effect of mitoK(ATP) channel appears to be dependent on the PKC-mediated signal pathway.

Adenosine Triphosphate↗
PubMedDate not supplied

Elemental composition of ischemic myocardium determined by x-ray microanalysis.

Elemental composition of ischemic myocardium was attempted with x-ray microanalysis. Energy dispersive spectrum exhibited calcium K alpha and phosphorus K alpha peaks from mitochondrial deposits, and Ca K alpha peaks from nucleus, contraction bands, and Z lines of the ischemic myocardial cell. Ca and P contents were confirmed with wavelength dipersive spectrometers. Mg was present in the mitochondrial deposits which lacked Ca. This study suggests a formation of phosphate salt of Ca at different intracellular sites and also of Mg with mitochondrial deposits.

Animals↗
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Cytotoxicity of TNT and its metabolites.

The production and storage of explosives has resulted in the environmental accumulation of 2,4,6-trinitrotoluene (TNT). The biotransformation products of the nitroaromatic compound TNT and metabolites in mammalian cells in culture and their cytotoxicity are studied. We report after our analysis by reverse phase high performance liquid chromatography (HPLC) that the most prevalent biotransformation product of TNT in the NG108 neuroblastoma cells is primarily monoamino-dinitrotoluene (2Am-DNT). It causes toxic effects based on trypan blue exclusion and LDH-release colorimetric assays.

Animals↗
PubMedDate not supplied

Delay in the diagnosis and prognosis of caecal carcinoma--a study of 20 cases.

BACKGROUND: Caecum is the dilated part of the right colon situated in the right iliac fossa, therefore the etiology of this cancer is similar to those of the rest of the colon. Caecal carcinoma is more common in developed countries but it is not a rare disease in underdeveloped countries. This is more common in high socio-economic people who use less fibrous and purified diet. With improvement in health education and social status of the people of Pakistan, there is an emerging trend of Westernization in our society. This may increase the incidence of cancer in Pakistan. Carcinoma of caecum is curable disease is diagnosed early and treated. If we are aware of the pathogenesis, etiology, clinical presentation and management of the disease, we can offer a lot to these patients by diagnosing the caecal carcinoma at an earlier stage, this was the aim of this study. METHODS: 20 cases (15 males and 5 females) of Carcinoma of Caecum were studied from January 1997 to December 1999. Out of these six patients presented in emergency ward, 2 as acute appendicitis and 4 as intestinal obstruction. After routine non-specific investigations, our specific investigations included USG abdomen, barium contrast studies and colonoscopy, Barium study and USG remained of primary importance. RESULTS: Most of the patients were between age 45-65 years, oldest patient being 80 years old and the youngest was of only 30 years. Most of the patients presented as mass in the right iliac fossa and only some patients as intestinal obstruction. Right hemicolectomy with primary ileo-transverse anastomosis was our standard surgical procedure and was done in about 14 cases. But in some cases ileo-transverse by-pass operation was done as the growth was locally advanced. However, only the omental biopsy was taken in the cases where carcinoma was too advanced. CONCLUSIONS: We think that our sociodemographic factors put a hindrance in detection of this carcinoma at early stages and therefore curative procedures are difficult to bear good results.

Adenocarcinoma↗
PubMedDate not supplied

Effect of oral and injectable contraceptives on serum calcium, magnesium and phosphorus in women.

BACKGROUND: This study aims at evaluating serum calcium, magnesium and phosphorus levels in women taking oral and injectable contraceptives. METHODS: Serum calcium, magnesium and phosphorus were measured in 50 women taking oral contraceptives (Lofeminal) and 50 women taking injectable contraceptive (Depo-medroxy progesterone acetate and Norigest). These women were used as controls before starting these contraceptives. RESULTS: There was significant decrease in serum levels of calcium, magnesium and phosphorus in women taking oral contraceptives but there was significant increase in these minerals in women taking injectable contraceptives. CONCLUSIONS: It is suggested that these contraceptives should be used with due care and with proper investigations of the women before and during the therapy.

Adult↗
PubMedDate not supplied

Prevalence of Helicobacter pylori in Dhulikhel Hospital, Kathmandu University Teaching Hospital: a retrospective histopathologic study.

OBJECTIVE: The main objective of this study was to determine prevalence of Helicobacter pylori infection in Dhulikhel Hospital, Kathmandu University Teaching Hospital. METHODOLOGY: Endoscopic antral biopsies from January 1, 2004 to August 31, 2005 were studied retrospectively. Hematoxylin and eosin and Giemsa stained histological sections were examined. RESULTS: Out of 224 patients (Male 125 and female 99) who underwent endoscopic biopsy and included in the study, a total of 76 (33.9%) patients (Male 50 and female 26) were infected by H. pylori. The mean age of the H. pylori infected patients was 40.2 years (SD 16.0). The infection by H. pylori was significantly higher in males than females (p<0.05) with male to female ratio of 1.9:1. The most common (31.3%) histopathologic finding was chronic superficial gastritis followed by normal histology (30.8%). A total of 10 cases (4.5%) of adenocarcinoma and 16 cases (7.1%) of intestinal metaplasia were detected and neither of them showed presence of H. pylori. Two cases (0.9%) were diagnosed as suspected malignancy and both were negative for H. pylori infection. Among gastritis, H. pylori was most frequently observed in chronic active gastritis (86.1%). Two of 69 cases (2.9%) of normal gastric mucosa showed H. pylori.

Adolescent↗
PubMedDate not supplied

Determination of thiamphenicol in bovine plasma by liquid chromatography.

A liquid chromatographic method is described for the measurement of thiamphenicol in bovine plasma. The plasma (1 mL) is extracted with ethyl acetate. After the solvent is evaporated under a stream of nitrogen, the residue is reconstituted in methanol-water and analyzed by reverse-phase liquid chromatography with UV detection at 224 nm. The intra-day recoveries for bovine plasma spiked with 5 and 50 micrograms/mL of thiamphenicol were 102 and 101%, respectively, with coefficients of variation of 2.40 and 0.28%, respectively. The interday recoveries for the 5 and 50 micrograms/mL samples were 103 and 101%, respectively, with coefficients of variation of 3.40 and 0.94%, respectively. The sensitivity of the method allows quantitation to at least the 100 ng/mL level.

Animals↗