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Biomedical subjects

N A Ismail

Publications and source records attributed to N A Ismail.

At least 19 recordsLinked to original sources
PubMed2006

Peritoneal dialysis: a clinical update congestive heart failure and PD.

BACKGROUND: There is a belief that peritoneal dialysis may be an important treatment modality for refractory heart failure, allowing at least an improvement in quality if not quantity of life during the last stage of this debilitating chronic disease. This paper examines the rationale behind this modality, critically appraises the available literature, calls for more research in the area and puts forward a framework for considering peritoneal dialysis in refractory heart failure. CONCLUSION: When faced with a patient with refractory heart failure admitted to hospital on multiple occasions because of complications of volume overload, the following approach to initiating peritoneal dialysis should be considered: subjects for dialysis must have a minimal blood pressure, and those whose hemodynamic status improves with diuresis, even though they develop a pre-renal picture, may be the best candidates.

Diuretics↗
PubMed2004

Modeling of hemoglobin in dengue fever and dengue hemorrhagic fever using bioelectrical impedance.

This paper describes a model for predicting hemoglobin (Hb) by using bioelectrical impedance analysis (BIA) in dengue patients in the Hospital Universiti Kebangsaan Malaysia (HUKM). Bioelectrical impedance measurements were conducted on 83 (47 males and 36 females) serologically confirmed dengue fever (DF) and dengue hemorrhagic fever (DHF) patients during their hospitalization. The predictive equation for Hb was derived using multivariate analysis. We investigated all the parameters in BIA, patients' symptom and demographic data. In this developed model, four predictors (reactance (XC), sex, weight and vomiting) were found to be the best predictive factors for modeling Hb in dengue patients. However, the model can only explain approximately 42% of the variation in Hb status, thus single frequency bio-impedance stand-alone technique is insufficient to monitor Hb for the DF and DHF patients. Further investigation using multi-frequency BIA is recommended in modeling Hb to achieve the most parsimonious model.

Adolescent↗
PubMed2002

Impact of life style on the nutritional status of medical students at Ain Shams University.

This cross sectional study was carried out to assess the nutritional status of medical students and to determine its relation to their life style. The study involved 317 students at, Am Shams University. Anthropometric measurements such as weight, height, mid-arm circumference, triceps skin fold thickness and body mass index were measured. The students completed a self-administered questionnaire including data about some life style factors and food-frequency consumption. The study revealed that 41.3% of the students were of normal weight while 9.5% of the sample were underweight, 36.9% were overweight and 12.5% were obese. The mean mid upper arm circumference (MUAC) and mid arm muscle circumference (MAMC) of males was significant higher than that of females, while the mean triceps skin fold (TSF) of females was significant higher than that of males. The food frequency questionnaire analysis showed that most of students consume all food groups items faire. There was no statistical significant difference between the body mass index (BMI) of students and different types of food consumption. About two thirds of the students used to practice exercise, 26.9% of the students practiced exercise for less than 2 hours per week, while 33.9% of them for more than 2 hours. There was no statistical significant difference between the BMI of students and different types of exercise. However, there was significant higher percentage of males play sports and practice running (44.7% and 19.4% respectively) compared to (11.7% and 8.1%) of females. Sixty four percent of the students usually have regular meals. About 87.2% of obese compared to 64.9% of normal weight students eat snacks between meals, the difference was statistically significant. Obese individuals eat more during watching television and during feeling of stress compared to non-obese and the difference was statistically significant. The duration of practicing exercise, sports and playing computer was significantly higher in males than females. However, the duration of watching television was significantly higher in females than males. Logistic regression analysis results showed that family history of obesity and some life style factors as duration of computer use, eating more during stress time and snacking between meals were important risk factors for obesity. We concluded that about half of medical students were overweight and obese. The most important life style factors responsible for obesity were longer time spent using computer, eating more during time of stress and snacking between meals. Also, genetic factors played an important role in development of obesity. It is recommended to develop nutritional education and physical activities programs to face the problem of increasing the rate of overweight and obesity among university students.

Adolescent↗
PubMed2001

Pre-eclampsia: epidemiology and outcome of 995 cases.

OBJECTIVE: To study the epidemiology and pregnancy outcome of pre-eclampsia at Ain Shams University Hospital for Obstetrics and Gynecology. STUDY DESIGN: A case control study involved 995 cases of pre-eclampsia, 227 cases with chronic hypertension and 1375 cases with normal pregnancy delivered during the year 2000 at Ain Shams University Maternity Hospital. All these cases were critically analyzed regarding to some risk factors as age, parity, blood group, diabetes mellitus, Rhesus factor and multiple pregnancy. The outcomes of all these 3 groups were compared regarding to maternal and fetal morbidity and mortality. RESULTS: Pre-eclampsia was more common in elder age, blood group B, in Rhesus negative, during summer, multiple pregnancy and in patients with diabetes mellitus. The difference was statistically significant regarding all these risk factors (p < 0.01) when compared with cases of chronic hypertension and patients with normal pregnancies. CONCLUSIONS: In this work pre-eclampsia was found to be an important cause for maternal and fetal mortality. Also it was found to be an important cause for premature deliveries.

Egypt↗
PubMed2001

Development of weight gain charts for healthy Egyptian pregnant women.

A prospective study was conducted to develop weight gain charts for healthy Egyptian pregnant women and to determine the relationship between different anthropometric indicators and favorable birth weight. A total of 830 pregnant women were enrolled in the study. The mean total weight gain was 9.3 kg. The velocity growth chart that were developed for weight gain showed that the increment of weight was about one kg up to the 4th gestational month, then, a steady increase of 0.37 kg per week till the end of pregnancy. The mean total gain in mid upper arm circumference (MUAC) was 0.8 cm and in triceps skin fold was 1.9 mm. There was a highly positive correlation between all anthropometric indicators studied and the birth weight. However only total weight gain and weight of the mother at first trimester showed significant relation with birth weight after using multi regression analysis. It is recommended to use the developed weight gain charts for monitoring the nutritional status of pregnant women and the MUAC and triceps skin folds are to be used for screening women at risk for malnutrition.

Adult↗
PubMed1997

Nicotine and stress: effect on sex hormones and lipid profile in female rats.

This work aimed to study the changes in sex hormones and lipid profile in adult female albino rats subjected to treatment with nicotine (N), immobilization stress (S), or their combinations (N+S). These treatments were applied either for one day (T1) or daily for 10 days (T10), after which rats in the estrus stage were used for the determination of plasma corticosterone (CS), serum sex hormones as progesterone (P), estrogen (E), FSH, LH and serum lipid profile including total cholesterol (TC), HDL-C, LDL-C, triacylglycerol (TG) and non esterified fatty acids (NEFA). It was clear that either N or S raised plasma CS and serum P levels in both the treatment regimens and that N+S induced a higher level of these hormones compared to each treatment alone. Serum E level was only elevated during T10 regimen only. An increase in serum LH level was only observed after a single exposure to either N or S, however their combination abolished the stimulatory effect induced by each treatment alone. Serum FSH was not altered by exposure to either N or S alone in both regimens, but in the T10 regimen their combination significantly lowered FSH level. Regarding the effect on serum lipid profile, serum TC was increased in all T10 regimen groups. LDL-C was increased by N+S treatment in both regimens, however no change in HDL-C level was observed in all groups. Serum NEFA was increased in all the treated groups during T10 regimen, while in the T1 regimen NEFA level was only elevated by the combination N+S. Serum TG was insignificantly altered in all the treated groups. The observed changes in the lipid pattern were attributed to the alterations occurred in CS and female sex hormones that caused by N, S or their combinations.

Animals↗
PubMed1997

Injury-induced alterations in newly synthesized sulphated proteoglycans from rabbit arterial neointima covered by regenerated endothelium.

Proteoglycan (PG) synthesis is a highly regulated, dynamic process that is known to be altered during atherogenesis. Endothelial injury, which may be the primary event in atherosclerosis, has been reported to stimulate PG synthesis and accumulation in the arterial extracellular matrix. The objective of this investigation was to study injury-induced alterations in PG synthesis and accumulation in the neointima, developed in response to a selective balloon catheter de-endothelialization of aortas of normocholesterolaemic rabbits. One group of rabbit aortas was incubated with 35S-Na2SO4 for 8 h, to study in vitro the de novo synthesis of sulphated PG. Another group of rabbit aortas was used to study PG accumulated in aortic neointima vs. PG present in intima-media of normal aortas. Newly synthesized sulphated PG was characterized by light microscopic radioautography and size exclusion chromatography. Purified intimal-medial PG extracts from unlabelled aortas were analysed for protein and glycosaminoglycan (GAG) content and GAG distribution pattern. Results from this study revealed that the neointima of injured aortas synthesized sulphated PG at a significantly higher concentration than the intima of normal aortas. Size exclusion chromatography revealed that neointima synthesized higher molecular weight PG, and in a higher proportion, than its counterpart PG from normal aortas. PG accumulated in neointima of injured aortas showed a significantly altered GAG distribution pattern. These data confirm that neointima developed in response to injury synthesizes and accumulates PG which is altered compared to PG present in the intima-media of normal aorta.

Animals↗
PubMed1995

Effect of calcium channel antagonists in modifying the inhibitory influence of adenosine on insulin secretion.

The present work was performed to study the effect of two calcium channel antagonists, namely verapamil (CAS 52-53-9) and nifedipine (CAS 21829-25-4) in modifying the inhibitory influence of adenosine on insulin secretion from isolated rat pancreatic islets. The combined effect of adenosine and these agents on serum insulin and glucose levels in vivo was also investigated. Both verapamil and nifedipine at 100 mumol/l and 1 mumol/l, respectively, produced a significant inhibition of glucose-stimulated insulin secretion from pancreatic islets. Combination of these agents with adenosine 10 mumol/l did not modify the inhibitory effect of adenosine on insulin secretion. Verapamil (21.6 mg/kg b.wt.) and nifedipine (5.4 mg/kg b.wt.) intraperitoneally injected prior to glucose loading produced a significant increase in serum glucose with an accompanied decrease in serum insulin levels. Concurrent administration of verapamil with adenosine neither affected the hyperglycaemic nor the hypoinsulinaemic effects of adenosine, whereas combined administration of nifedipine and adenosine decreased the hyperglycaemic effect of adenosine but not its hypoinsulinaemic effect. These results may indicate that these calcium channel antagonists do not interact with adenosine receptors which mediate its inhibitory effect on insulin secretion.

Adenosine↗
PubMed1994

Combined effect of adenosine, alpha adrenergic and adenosine antagonists on serum insulin and insulin secretion from rat pancreatic islets.

1. The effect of adenosine separately or in combination with alpha-1 adrenergic antagonist prazosin and alpha-2 adrenergic antagonist yohimbine as well as adenosine antagonists 8-phenyltheophylline and xanthine amine conjugate on glucose-induced insulin secretion from isolated rat pancreatic islets was studied. 2. Their in vivo effects on serum glucose and insulin levels were also investigated. Adenosine at 10 and 100 microM inhibited significantly, insulin secretion from the isolated islets whereas at 10 mM slightly increased the secretion of insulin. 3. Prazosin used at 100 microM inhibited insulin secretion. When it combined with adenosine (10 microM) it augmented the inhibitory effect of adenosine. 4. In vivo prazosin (21 mg/kg body wt) caused a hyperglycaemia which was accompanied by hypoinsulinaemia. 5. Concurrent administration of this drug with adenosine neither affect the hyperglycaemic nor the hypoinsulinaemic effects of adenosine. 6. On the other hand, yohimbine (100 microM) has no effect neither separately nor in combination with adenosine (10 microM) in modulating the inhibitory effect of adenosine on insulin secretion. 7. When Yohimbine administered at 19.5 mg/kg body wt it did not alter serum glucose but it markedly increased the serum insulin level. Its combined administration with adenosine reduced the hyperglycaemic effect of adenosine with a remarkable increase in serum insulin. 8. Both adenosine-antagonists were ineffective in alteration of insulin secretion. 9. However, combination of 8-phenyltheophylline with adenosine (10 microM) totally blocked the inhibitory effect of adenosine on insulin secretion while xanthine amine conjugate failed to prevent this effect of adenosine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1994

Lipoprotein-proteoglycan complexes from injured rabbit aortas accelerate lipoprotein uptake by arterial smooth muscle cells.

Lipoprotein-proteoglycan (LP-PG) complexes are taken up more avidly by macrophages and smooth muscle cells (SMCs) than native lipoproteins (LPs). The enhanced uptake may contribute to lipid accumulation and foam cell formation during atherogenesis. Endothelial injury is known to alter proteoglycan (PG) synthesis and distribution in the neointima developed in response to injury. The present study examines the uptake and degradation of LP-PG complexes, derived from PG of injured aortas by arterial SMCs. Rabbit apo-B lipoprotein (LP), including VLDL, IDL and LDL was isolated by ultracentrifugation and coupled with PG extracted from normal aortas (NPG) or with PG from injured aortas (IPG). Rabbit aortic SMCs were cultured from intima-media explants, incubated with 125I-LP, 125I-LP-NPG or 125I-LP-IPG for 20 h at 37 degrees C. LP binding, internalization and degradation were markedly increased (P < 0.001) for LP-NPG and LP-IPG over native LP. Competition experiments indicated that more than 50% of the LP-PG complexes were taken up by the apo-B/E receptor pathway. Phagocytosis was the second important route of uptake of these complexes, whereas the scavenger receptor played a minor part in the uptake and degradation of LP-PG complexes. Data from this study indicate that LP-PG complexes accelerate LP uptake and degradation by SMC more than native LP. Therefore, these complexes may contribute to lipid accumulation by SMC, thus generating foam cells. Furthermore, LP-PG complexes prepared from PG of injured aortas are more effective in lipid accumulation than LP-PG complexes from PG of normal aortas.

Animals↗
PubMed1994

Isolation of lipoprotein-proteoglycan complexes from balloon catheter deendothelialized aortas and the uptake of these complexes by blood monocyte-derived macrophages.

Lipoprotein-Proteoglycan (LP-PG) complexes from the neointima, developed in response to injury, were studied to examine their ability to stimulate lipid accumulation in blood monocyte-derived macrophages (BMDM). LP-PG complexes were extracted from intimal-medial tissues from normal and balloon catheter deendothelialized aortas of normocholesterolemic rabbits, in 0.16 M NaCl for 24 h at 4 degrees C. The extract was purified through an anti-apo-B affinity column. Adsorbed material dissociated with 4 M Gu-HCI buffer was analyzed for lipoproteins (LP) and glycosaminoglycans (GAG). Results demonstrated that LP-PG complexes consisted of apo-B associated with chondroitin sulfate and hyaluronic acid. BMDM were incubated with 125I-LP, 125I-LP-NPG (from normal aortas) or 125I-LP-IPG (from injured aortas) for 20 h at 37 degrees C. LP binding, internalization and degradation was markedly increased for LP-NPG and LP-IPG over native LP. Phagocytosis appeared to be the primary route of uptake of LP-PG complexes. Competition experiments indicated that about 40% of the uptake of LP-PG complexes is mediated by the apo-B/E receptor pathway. The scavenger receptor played a minor part in the uptake of LP-PG complexes. Data from this study indicate that LP-PG complexes are present in normal and injured aortas of normocholesterolemic rabbits and these complexes accelerate LP uptake by BMDM more than native LP. Therefore, LP-PG complexes may contribute to lipid accumulation by BMDM, thus generating foam cells. Furthermore, LP-PG complexes prepared from PG of injured aortas are more effective in lipid accumulation than LP-PG complexes from PG of normal aortas.

Animals↗
PubMed1983

Effects of alpha-adrenoceptor agonists and antagonists on insulin secretion, calcium uptake, and rubidium efflux in mouse pancreatic islets.

Epinephrine, norepinephrine or the more selective alpha-2 adrenoceptor agonist, clonidine, inhibited insulin release from isolated pancreatic islets of lean mice or obese mice homozygous for the gene ob. Clonidine was highly effective at 0.1 mumol/l. In contrast, the preferential alpha-1 adrenoceptor agonist, phenylephrine, had no or only a modest effect at 10 mumol/l. The effects of norepinephrine or clonidine were counteracted by yohimbine, a preferential blocker of alpha-2 receptors, but not by prazosine, an alpha-1 receptor blocker. The glucose-stimulated uptake of 45Ca2+ in the islets was only consistently inhibited by epinephrine. This effect was counteracted by yohimbine. Clonidine had no effect on the release of 86Rb+ from preloaded islets. It is concluded that insulin secretion is suppressed by alpha-2 receptor agonism in the pancreatic beta-cells and that this effect is mediated by mechanisms other than the transmembrane fluxes of calcium or potassium ions.

Adrenergic alpha-Agonists↗
PubMed1982

Bromocriptine and insulin secretion.

The dopaminergic drug bromocriptine inhibited the release of insulin from isolated mouse pancreatic islets. The effect was counteracted by haloperidol or pimozide. It is suggested that insulin release may be inhibited through activation of D-2 dopaminergic receptors in the pancreatic beta-cells.

Animals↗
PubMed1977

Effects of guanosine on insulin secretion and adenylyl and guanylyl cyclase activities of isolated rat islets of Langerhans.

The effect of guanosine on insulin secretion, adenylyl and guanylyl cyclase activities of isolated rat islets of Langerhans was investigated. Guanosine (1-100 micron) inhibited glucose, tolbutamide, theophylline and prostaglandin E2-stimulated insulin secretion although it failed to affect glucagon stimulated secretion. Prostaglandin E2-stimulated adenylyl cyclase activity of islets was inhibited by guanosine although guanosine had no effect on basal, fluoride, glucagon or GTP-stimulated activity. Guanosine markedly decreased basal guanylyl cyclase activity of islets. These results suggest that guanosine may affect insulin release by inhibiting adenylyl and guanylyl cyclase activities in the beta-cell thereby decreasing the intracellular concentrations of cyclic nucleotides. This effect may be important in modulating the secretory response of the islets to a variety of hormonal agents.

Adenylyl Cyclases↗
PubMed1977

Adenosine and the regulation of insulin secretion by isolated rat islets of Langerhans.

The effect of adenosine in insulin secretion and adenylate cyclase activity of rat islets of Langerhans was investigated. Adenosine inhibited insulin secretion stimulated by glucose, glucagon, prostaglandin E2, tolbutamine and theophylline. Adenosine decreased basal adenylate cyclase activity of the islets as well as that stimulated by glucagon prostaglandin E2 and GTP, although fluoride-stimulated activity was not affected. Neither insulin secretion nor adenylate cyclase activity of the islets was affected by adenine, AMP or ADP. The inhibitory effect of adenosine on adenylate cyclase activity was not altered by either phenoxybenzamine (alpha-adrenergic blocker) or propranolol (beta-adrenergic blocker), suggesting that the effect is not mediated through the adrenergic receptors of the islet cells. These results suggest that the intracellular concentration of adenosine in the beta-cell may play a role in regulating insulin secretion and that this effect may be mediated via alterations in the activity of adenylate cyclase in the beta-cell.

Adenosine↗