Search PubMed⌕ Search

Biomedical subjects

S Mohamed

Publications and source records attributed to S Mohamed.

At least 55 records · Page 3Linked to original sources
PubMed1995

Is sex a factor in determining operative risk for aortocoronary bypass graft surgery?

BACKGROUND: This study examines trends and sex differences in characteristics of patients referred for bypass graft surgery to identify factors associated with operative morbidity and mortality. METHODS AND RESULTS: Data were collected prospectively on consecutive patients (1132 men and 355 women). Over time, the proportion of patients > 65 years old, with diabetes, or requiring urgent surgery, increased. Predictors of mortality were age > 75 years, urgent surgery, and poor left ventricular (LV) grade. Women were older (62 +/- 9 versus 59 +/- 9 years, P < .001) and had more varicose veins (18% versus 7%, P < .001), diabetes (27% versus 18%, P < .001), hypertension (48% versus 41%, P < .05), peripheral vascular disease (16% versus 12%, P < .05), and more severe angina (P < .001). There were no sex differences in prior myocardial infarction (59% versus 62%) or need for urgent surgery (17% versus 18%). Women had a higher ejection fraction (51% +/- 12% versus 47% +/- 14%, P < .001) and fewer diseased vessels (2.4 +/- 0.7 versus 2.6 +/- 0.6, P < .001) and received fewer grafts (2.9 +/- 0.9 versus 3.3 +/- 0.8, P < .001). Women had smaller body size but were no more likely to have small target vessels (< 1.5 mm). There was no sex difference in operative mortality (1.4% versus 1.1%), perioperative myocardial infarction (4.8% versus 3.5%), need for intra-aortic balloon pump (10% versus 8%), stroke (1.7% versus 1.4%), reexploration for bleeding (1.7% versus 1.7%), or leg infection (2.0% versus 1.4%). Women had fewer sternal wound infections (0.6% versus 2.2%, P < .05). CONCLUSIONS: Predictors of mortality include advanced age, decreased LV function, and need for urgent surgery. With time, despite increasing age, associated diabetes, and increased urgent surgery, operative mortality has decreased. Women were older and had more diabetes and hypertension but less extensive disease and better LV function. Bypass graft surgery was associated with equally low mortality in women and men (1.4% versus 1.1%). Concern over increased operative mortality in women should not bias referral patterns for angiography and coronary bypass graft surgery.

Aged↗
PubMed1994

Are patients receiving amiodarone at increased risk for cardiac operations?

Amiodarone therapy has been implicated as a risk factor for cardiothoracic surgical procedures. In patients undergoing map-guided surgical procedures for the treatment of ventricular tachycardia, we compared the perioperative course of those receiving long-term amiodarone therapy (n = 36) versus that in those not receiving the drug (n = 31). The two groups were similar with respect to age, sex, presenting symptoms, functional class, extent of coronary artery disease, presence of a ventricular aneurysm, technique of ventricular tachycardia ablation, cross-clamp or pump time, the number of vessels grafted, the operative fluid balance, and a need for intraaortic balloon pump or inotropic agent support. In 5 patients receiving amiodarone, epinephrine was required to maintain a normal systemic vascular resistance and adequate arterial pressure. Postoperatively, 6 patients (17%) on amiodarone therapy suffered acute respiratory failure. In spite of aggressive therapy, 3 of these patients died. Only 1 patient not receiving amiodarone died of a stroke. We conclude that amiodarone therapy in patients undergoing open heart operations is associated with an increased risk of severe pulmonary complications (p = 0.03 by Fisher's exact test). Amiodarone therapy should be withheld in patients with ventricular tachycardia until they have been assessed as candidates for possible surgical intervention.

Aged↗
PubMed1994

Conductance catheter measurements of left ventricular volume in the intact dog: parallel conductance is independent of left ventricular size.

OBJECTIVE: It has recently been suggested that conductance catheter parallel conductance (alpha Vc) is a function of left ventricular volume. To confirm this, alpha Vc was measured in this study over a wide range of steady state volumes. In addition, conductance derived volumes were compared to those obtained by radionuclide angiography to determine if the conductance catheter can be used to measure absolute left ventricular volume accurately in the intact dog heart. METHODS: Seven dogs were anaesthetised and instrumented with left ventricular conductance and pressure tip catheters, a flow through rho cuvette to continually measure blood resistance, a thermodilution catheter, and a venous catheter for volume infusion/withdrawal. Conductance and angiographic data were acquired at 8(SD 1) variably loaded states. Parallel conductance was measured twice at each state using a saline dilution technique and a new non-linear algorithm that allows variability in the observations of both maximum and minimum conductance volumes. RESULTS: The mean value of alpha Vc was 89.1(18.0) ml (71.8 to 111.3 ml) with a mean within-animal coefficient of variation of 7.3(3.4)%. Multiple linear regression using dummy variables to account for the large interanimal variability did not reveal any relationship between alpha Vc and either maximum or minimum left ventricular volume. Furthermore, no difference was found when alpha Vc values measured at the lowest and highest loading levels in each dog were compared. Linear regression showed good agreement between conductance and radionuclide derived end diastolic volumes (slope = 0.94, R = 0.9, p < 0.001). CONCLUSIONS: While alpha Vc varies between animals, it remains constant within any given animal over a broad range of left ventricular volumes. Thus the conductance catheter can provide reliable absolute left ventricular volume measurements under steady state conditions.

Animals↗
PubMed1994

Results of left ventricular aneurysmectomy with a tailored scar excision and primary closure technique.

Controversy exists concerning which surgical technique is optimal for ventricular aneurysm repair. In 92 (97%) of 95 patients, we tailored scar excision to remove nonfunctioning wall and restore left ventricular geometry and shape toward normal while allowing linear closure. Preoperative and/or postoperative multiple gated acquisition scans were obtained in 76 (83%) of 92 patients and Doppler echocardiograms in 79 (86%) of 92. Before operation 78 patients (85%) were in New York Heart Association class III or IV with congestive heart failure in 58 (63%), angina in 69 (75%) and syncope in 46 (50%) of the 92 patients. Additional operative procedures included aorta-coronary bypass grafting in 81 patients (88%), septoplasty in 4 (4%), and arrhythmia ablation in 54 (59%). Hospital mortality was 3 (3%) of 92 patients. There have been 15 late deaths caused by congestive heart failure with or without mitral regurgitation (7 of 15). Among survivors 66 (89%) of 74 were symptomatically improved with 25 (34%) of 74 in New York Heart Association class I, 24 (32%) of 74 in class II, 19 (26%) of 74 in class III, and 6 (8%) of 74 in class IV. Actuarial survival was 88%, 86%, and 80% at 1, 2, and 5 years, respectively, and was not different for patients with a preoperative left ventricular ejection fraction less than 20%. In 47 patients with an anterior aneurysm who had preoperative and postoperative studies, multiple gated acquisition scans showed improvement in left ventricular ejection fraction from 23% to 30% (p < 0.001). Preoperative Doppler echocardiograms showed significant mitral regurgitation (2+ or more) in 26 (36%) of 72 patients studied. Of these, 21 had postoperative studies and mitral regurgitation was improved by at least one grade in 12 (57%) of 21 patients. We conclude that aneurysm repair with a tailored scar excision and linear closure is associated with low operative mortality, objective evidence of improvement in left ventricular function, symptomatic relief, and long-term survival even in patients with advanced left ventricular dysfunction and mitral regurgitation.

Echocardiography, Doppler↗
PubMed1993

Ecology of Biomphalaria alexandrina the snail vector of Schistosoma mansoni in Egypt.

The patterns of spreading and seasonal variation of population density of Biomphalaria alexandrina, the snail vector of Schistosoma mansoni in Egypt, in correlation with some environmental parameters were studied for 1988-1990 in four irrigation canals in Giza and Qalyoubiya Governorates. Results shown that the spreading patterns of snails along canals are changeable because of water current and irrigation activities. The snail population density showed two peaks, different in height, in April-May and November-December separated by two bottoms following the Winter Closure and during the hot summer season. The height of the peaks appears to be dependent on the extent of the "Winter Closure" and the prevailing water temperature. Two snail sampling tools, the dip-net and drag scoop, were used concurrently in this study. No considerable difference in sampling efficacy was recognized between these tools in the case of Biomphalaria. However, the dip-net appears to be more efficient in sampling other pulmonates while the drag scoop is more efficient in sampling prosobranchs. It is also realized that double sampling of 50% of sampling sites the next day should be satisfactory as a quality control system in snail population studies.

Animals↗
PubMed1990

Inbreeding effects on reproductive outcome in a Sudanese population.

926 women attending the Obstetrics and Gynaecology Department of the Faculty of Medicine, Khartoum, were investigated to study the inbreeding effects on reproductive profiles and morbidity of the offspring. 49.5% of the women had married their first cousins and 13.8% had married more distant relatives. Altogether, 4,471 pregnancy outcomes were analysed including abortions, still births, neonatal and childhood deaths, physical deformity, mental retardation and other congenital abnormalities. No significant difference in the reproductive loss or net fertility was observed between the inbred and outbred groups. Only the proportions of childhood deaths were found to be significantly higher in the inbred marriages (p less than 0.005). The morbidity was also not affected by the practice of inbreeding.

Congenital Abnormalities↗
PubMed1989

Bioactivity of some chemotherapeutic agents in selected polyethylene glycol ointment bases.

Six different chemotherapeutic agents were individually incorporated in each of fourteen selected polyethylene glycol ointment bases, and their bioactivities were assessed using different diffusion techniques. The prepared medicated ointments were evaluated for drug release using the standard microbiological agar cup diffusion, the long period method and the short period method, as well as dialysis through artificial kidney membrane. On the basis of consistency, stability and diffusion results, formulation 11 was the most suitable base for ampicillin, formulation 14 for oxytetracycline HCl, formulation 10 and 9 for neomycin sulphate, and preparation 10 for chloramphenicol. On the basis of the results of drug release, it was evident that formulation 3 was the best for ampicillin and chloramphenicol, formulation 2 for erythromycin, formulation 4 for neomycin sulphate, formulation 12 for sulphadimidine, and formulation 14 for oxytetracycline HCl.

Anti-Bacterial Agents↗
PubMed1988

A diagnostic dilemma in Jordan: two child abuse case studies.

Child abuse was diagnosed in two Jordanian children. The first was a 15-month-old female infant admitted with a history of convulsions and loss of consciousness. The child had previous head and limb injuries resulting in bilateral subdural hematomas and fractures at different stages of healing of femur and pelvis. The second was a 3-year-old male admitted with history of head injury due to an alleged fall. Examination revealed fractured ribs, bruised eye and face, hemothorax, subperiosteal and subdural hematomas. Both children have sustained physical and mental handicaps. This is the first report of child abuse in Jordan. In Jordan, as in the rest of the world, a high index of suspicion is needed to diagnose child abuse early enough to save the affected child its serious sequelae.

Battered Child Syndrome↗
PubMed1986

Prenatal ethanol exposure and cerebellar development in rats.

Rats of Sprague-Dawley strain were fed a liquid ethanol diet that was nutritionally balanced and provided 35% of calories as ethanol. Control animals were pair-fed and received the same liquid diet with maltose-dextrins substituting for ethanol. At birth the pups of both the experimental and control groups were fostered by surrogate mothers which received normal rat chow ad libitum. An average of eight alcohol-fed and eight pair-fed pups were killed at 0-1, 5, 7, 10, 14, 21, 28, and 42 postnatal days. The fixed cerebella of these pups was bisected in the midvermal plane and one-half was embedded in paraffin and the other in Araldite. Projection drawings of hematoxylin and eosin-stained paraffin sections were made at 50X magnification. Using the graphics plate of an Apple II computer, the circumference and area of the vermal cerebellum was determined. We found that at all the time sequences studied the area and circumference of the cerebellum were significantly reduced in ethanol-exposed pups compared with the pair-fed controls.

Animals↗
PubMed1986

Wound healing properties of cimetidine in vitro.

Cimetidine was one of a variety of drugs frequently given to surgical patients perioperatively tested for their effect on gap closure of wounded monolayers of human fascia cells in vitro. Cimetidine-treated cultures closed faster and had greater cell proliferation than controls. Closure of cimetidine-treated cultures occurred at six hours compared to ten hours in controls. Cimetidine concentrations of 1000 micrograms/ml resulted in 13.5 +/- 0.67 (SEM) X 10(4) cells/cm2 at six hours compared to 7.9 +/- 0.48 X 10(4) cells/cm2 in controls (p less than 0.05); the area covered by cells was 6.5 +/- 0.02 mm2 in treated cultures compared to 3.0 +/- 0.01 mm2 in controls (p less than 0.05). It is concluded that cimetidine stimulates fibroblast proliferation in vitro.

Cells, Cultured↗
PubMed1982

Super viscous silicone liquid in retinal surgery.

Very high viscosity (12500 centistokes) liquid silicone was injected into the vitreous of 47 eyes of 46 patients with complicated retinal detachment over a two year period. Only eyes judged inoperable by scleral buckling and/or vitrectomy techniques were considered. Complete anatomical reattachment was achieved in 34 cases (72%) while partial reattachment was achieved in a further six cases (13%). All eyes in which complete or partial retinal reattachment was achieved showed improvement in vision but this was usually restricted to count fingers or 6/60 at 3 months to 2 years follow-up. Mounting evidence now suggests that previous clinical opinions claiming an unacceptable toxicity rate with liquid silicone may be misleading.

Child↗
PubMed1976

[Fetal haemoglobin levels in acquired and congenital haematological diseases and malignant tumours in adults (author's transl)].

Hb F values were estimated in 336 adults on 525 occasions. A variable elevation appeared not only in patients with a variety of haematological diseases, but also in conjunction with malignant neoplasms, liver disease etc. The highest values were encountered in cases of pernicious anaemia, haemolytic anaemia, panmyelopathy and plasmocytoma. The determination of Hb F in peripheral blood smears by means of this extremely simple elution method (Betke and Kleihauer) represents a useful tool in the diagnosis of haematological disorders in adults, especially the haemoglobinopathies. The possible causes of this biochemical redifferentiation of erythropoiesis are discussed.

Adult↗
PubMedDate not supplied

Effects of hypothalamically elicited emotional behaviors on the plasma levels of estradiol and IGF-1.

We examined changes in the plasma levels of estradiol (E2), insulin-like growth factor-1 (IGF-1), ACTH, cortisol and catecholamines accompanying various kinds of hypothalamically elicited emotional behaviors in female cats. The emotional behaviors consisting of restlessness, threat and searching-biting (S-B) were elicited intermittently for 6 h by electrical stimulation of the anterior hypothalamus (AH), ventromedial hypothalamus (VMH) and lateral hypothalamus (LH), respectively, in awake and free-moving conditions. The blood was sampled three times immediately before, 1 h after and 6 h after the start of stimulation. The plasma levels of ACTH, cortisol and catecholamines significantly increased in both restlessness and threat behaviors, whereas in the S-B behavior, the ACTH level significantly increased, while the cortisol level showed a slight nonsignificant increase. No changes were observed in the plasma catecholamine levels in the S-B behavior. The plasma E2 level significantly increased in threat behavior after 1 and 6 h of stimulation compared to the prestimulation levels, and the level also increased in comparison to the control group after 1 h. In contrast, the restlessness and S-B behaviors had little or no effect on the E2 level. No significant changes were observed in the plasma levels of IGF-1 in all behavior groups. These findings suggest that various hypothalamically elicited emotional behaviors have differential effects on the plasma E2, but not on the IGF-1 levels. Therefore, E2 and IGF-1 are regulated independently of each other.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

The use of novel antipsychotics in the older patient with neurodegenerative disorders in the long-term care setting.

Treating older patients with neurodegenerative disorders involves numerous challenges. The older patient population is expected to increase appreciably in the coming years; thus, there will be increasing numbers of these individuals requiring treatment. As a result, the appropriate choice of psychopharmacologic agents becomes an important decision in treating older patients with atypical antipsychotics. The atypical antipsychotic medications are replacing the high-potency conventional antipsychotics in the long-term care setting because of the lower risks of side effects. For instance, atypical antipsychotics have lower rates of extrapyramidal side effects and tardive dyskinesia. Double-blind placebo-controlled trials examining the use of risperidone and olanzapine have been published and indicate that both agents safely and effectively reduce agitation symptoms in long-term care patients with neurodegenerative disorders. For instance, based on these studies, the doses that appear efficacious in treating behavioral agitation in dementia are 0.5 to 1.5 mg per day of risperidone and 5 to 10 mg per day of olanzapine. In addition, there are open-label studies examining the use of quetiapine, which suggest that this agent is also safe and efficacious in patients with dementia. Doses used range approximately from 25 to 350 mg per day. Very few studies are available examining the newest atypical antipsychotics, ziprasidone and aripiprazole, in patients with neurodegenerative disorders. These studies do suggest that ziprasidone and aripiprazole are worth further study in the long-term care setting.

Aged↗