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Biomedical subjects

M Ismail

Publications and source records attributed to M Ismail.

At least 91 records · Page 5Linked to original sources
PubMed1993

The ocular effects of spitting cobras: II. Evidence that cardiotoxins are responsible for the corneal opacification syndrome.

Fractionation of H. haemachatus, N. nigricollis, N. nivea and N. melanoleuca venoms using Amberlite CG-50 and (NH4)HCO3 elution gradient chromatography yielded 11-13 fractions for each venom. One fraction, F X, from H. haemachatus, two fractions, F X and F XI, from N. nigricollis and one fraction, F VIII, from N. melanoleuca venoms possessed the whole of ocular activity of the venoms. The fractions were the only venom fractions that caused cardiac depressant activity; their effect was reversed by raising Ca++ concentration in the physiological solution; they did not influence the twitches of the phrenic nerve hemidiaphragm and guinea-pig ileum preparations. Further purification of the fractions on Sephadex G-50 followed by fractionation on Amberlite CG-50 yielded fractions free from phospholipase A2 activity but possessing the same ocular effects. Similarly, the cardiotoxin from commercial N. nigricollis venom caused the same ocular effects as the crude venom and its purified cardiotoxic fractions. All cardiotoxic fractions as well as N. nigricollis cardiotoxin, caused extensive chemosis, blepharitis and corneal opacification with corneal and subconjunctival neovascularization. On a weight basis, the cardiotoxins were weaker in their oculotoxic activity than the corresponding parent crude venoms possibly because of the potentiating effect of phospholipase A2 in the crude venoms. It is postulated that in spitting cobras the cardiotoxins are responsible for the corneal opacification syndrome. In other cobra venoms the stable binding of cardiotoxins with acidic proteins limits their possible ocular effects. Only in the venoms of the spitting species are the cardiotoxins present in an appropriately free form to cause the ocular opacification syndrome.

Animals↗
PubMed1993

Pregnancy outcome after expectant management of premature rupture of the membranes in the second trimester.

Because management of premature rupture of the membranes (PROM) at or before 26 weeks is controversial, we examined maternal and perinatal outcome after expectant management of 44 pregnancies complicated by this problem. Mean gestational age at preterm PROM was 23.9 +/- 1.7 (SD) weeks. The latency period between preterm PROM and delivery ranged from 1 to 68 days, with a medium of 6. Of the patients, 54.6% delivered within a week of PROM, and 79.5% delivered by four weeks; 77.2% developed chorioamnionitis, but despite this high incidence, there was no maternal sepsis or pelvic thrombophlebitis, and no maternal surgery was necessary. Perinatal outcome was 60.5% neonatal survival, 54.2% perinatal survival and a stillbirth rate of 10.4%. Respiratory distress syndrome, bronchopulmonary dysplasia, sepsis and intraventricular hemorrhage were common types of neonatal morbidity. There was no pulmonary hypoplasia, and limb deformity was seen in only two neonates. Costs of expectant management in pregnancies complicated by second-trimester PROM were estimated, and a strategy to reduce cost is suggested.

Adult↗
PubMed1992

Experimental treatment protocols for scorpion envenomation: a review of common therapies and an effect of kallikrein-kinin inhibitors.

Nine fatal cases from the sting of the scorpion Leiurus quinquestriatus are presented. All victims showed association of CNS and cardiovascular manifestations. Either the CNS or the cardiovascular effects could occur first in the early phases of the scorpion envenoming syndrome; the CNS manifestations, however, always preceded the terminal hypotension and cardiac arrest. Pharmacokinetic studies in rabbits following s.c. injection of the labelled venom showed that rapid absorption took place with about 70% of the maximum blood concentration reached within 15 min. Intramuscular injection of antivenom did not significantly affect the absorption of the venom or the other pharmacokinetic parameters. The total area under concentration time curve was not significantly different from that following i.v. injection, showing that nearly complete absorption of the venom from the s.c. site would occur in 7-8 hr. The i.v. infusion of venom into anaesthetized rats, at a rate comparable to the absorption rate from s.c. sites, allowed the determination of the minimum lethal dose (MLD) with reasonable accuracy. In rescue experiments, anaesthetized rats were injected s.c. with multiple MLD of venom and infused i.v. with drugs commonly used in the treatment of scorpion envenomation. The prepared potent specific antivenoms, but not the commercial polyvalent antivenom, rescued all animals from the lethal effect of the venom, even when injected late. Atropine, atropine+phentolamine, chlorpromazine, hydrocortisone and indomethacin were able, in varying degrees, to rescue some rats injected with 2 MLD of venom. Phentolamine, propranolol, hydralazine and calcium gluconate significantly prolonged the survival time, but did not rescue any animals. Chlorpheniramine, saline and 1/4 saline + 5% dextrose were without any effect. Aprotinin, the kallikrein-kinin inhibitor, was able to rescue half of the animals from the lethal action of the venom. Electrocardiographic studies showed that L. quinquestriatus venom, irrespective of the route of administration, causes myocardial ischaemia and either inferior or anterior wall infarction. This was associated with an initial moderate and a terminal severe bradycardia together with a variety of rhythm and conduction defects. Except for minor and transient electrocardiographic changes, either the prepared antivenoms or aprotinin protected rabbits and rats from the cardiac effects of the venom.

Adolescent↗
PubMed1992

Blood coagulation, fibrinolytic and inhibitory profiles in renal transplant recipients: comparison of cyclosporine and azathioprine.

Renal transplant recipients treated with cyclosporine (CS) have been reported to be at increased risk of thrombotic complications. The present study was intended to examine the blood coagulation, fibrinolytic, and inhibitory systems in such patients. Eight transplant recipients on maintenance immunosuppression with CS and prednisone were studied. Five transplant recipients maintained on azathioprine (AZA) and prednisone and 32 normal volunteers served as controls. Plasma antigen concentrations and/or activities of various proteins in the above pathways were measured. Both the CS and AZA groups exhibited significant elevations of factor IX activity, von Willebrand factor (vWF), D-dimer, protein C and tissue type plasminogen activator (t-PA) levels when compared with the normal controls. In addition, CS group showed a significant elevation of alpha 2-macroglobulin activity and AZA group showed a significant reduction in factor XII activity when compared with the normal controls. Comparison of data from CS and AZA groups revealed higher factor XII activity and vWF concentration in the former group. In conclusion, transplant recipients treated with long-term cyclosporine and prednisone exhibited significant elevation of plasma vWF, D-dimer and protein C concentrations. In addition, both CS and AZA-treated transplant recipients showed increased plasma concentrations of D-dimer and t-PA. The latter observations suggest in vivo thrombin generation, fibrin formation and degradation.

Adult↗
PubMed1991

Abdominal aortic aneurysm repair after renal transplantation with extracorporeal bypass.

The successful resection of an abdominal aortic aneurysm is presented in a patient who had undergone kidney transplantation 4 years previously. Because the transplanted kidney is more sensitive to ischemia than a normal one, a femoro-femoral bypass with a pump oxygenator was used for perfusion of the transplanted kidney during crossclamping. During the clamping time of 40 minutes kidney perfusion was maintained with a perfusion pressure of 60 to 80 mmHg and the flow was 600 to 1000 ml/min. A collagen-seeded Dacron graft (diameter: 18 mm, length: 12 mm) was interposed. The postoperative course was uncomplicated. We believe that performing the femoro-femoral bypass with a pump oxygenator is an effective and simple method for kidney protection in such operations.

Aorta, Abdominal↗
PubMed1991

Trauma management in a war zone: the Lebanese war experience.

Lessons learned from the Vietnam and Korean conflicts have emphasized the necessity of an organized preparedness for optimal management of casualties. The present report summarizes the experience of a tertiary care center in the present Lebanese war. Between 1975 and 1986, approximately 30,000 war casualties were treated at the American University of Beirut Medical Center (AUBMC). A disaster plan was implemented whenever more than 25 major trauma victims were received within 1 hour. In-field stabilization and emergency room (ER) thoracotomy were not employed. The results are illustrated by an analysis of 1,500 cases of abdominal trauma, (1,314 high-velocity gunshot wounds, 29 stab wounds, 157 blunt injuries). A total of 1,420 patients were operated on within 6 hours of admission and 711 within the first hour. Overall mortality was 130, 8.7%; 9.5% for gunshot wounds, 3.4% for stab wounds, and 2.5% for blunt trauma. One hundred forty-five patients or 9.7% had negative findings at laparotomy. The factors affecting mortality were hypotension on admission (26.5% for a BP less than 90 mm Hg and 2.8% for a BP higher than 90 mm Hg) and the presence of extra-abdominal injuries (14.4% with and 4.4% without). The chief causes of death were hemorrhage (3.7%), sepsis (2.1%), and ARDS (1.2%).

Abdominal Injuries↗
PubMed1991

Haemophilus somnus as a bacterial cause of pneumonia in buffalo calves in Egypt.

Haemophilus (H.) somnus strains were isolated from nasopharyngeal swabs collected from buffalo calves showing respiratory symptoms as well from pneumonic lung tissue samples, the incidence being 4.7% and 10.4%, respectively. The organism was not recovered from samples obtained from apparently healthy buffalo calves. All isolated strains were highly virulent to mice, causing acute septicaemia and death within 3-5 days from intraperitoneal inoculation with 7.5 x 10(6) viable organisms. All tested strains were resistant to tetracycline and sulphafurazole, but most strains were highly sensitive to gentamicin, ampicillin, penicillin G, and colistin sulphate. H. somnus must not be neglected as a causative agent of respiratory disorders in buffalo calves, in addition to other incriminated organisms.

Animals↗
PubMed1990

Do changes in body temperature following envenomation by the scorpion Leiurus quinquestriatus influence the course of toxicity?

Four fatal cases following scorpion sting in children are presented. Two victims had rectal temperature above 41 degrees C, the third exhibited a temperature of 40.9 degrees C from the combined effects of scorpion sting and heat stroke, while the fourth was hypothermic. All victims developed hypothermia 48 hr following the sting. The hyperthermia was effectively treated by acetaminophen suppositories, ice packs and water sponges. All victims showed late hypotension that was refractory to dopamine infusion. This was explained by bradykinin released by the venom blocking the dopaminergic receptors. Deterioration of the cortical activity of the victims maintained on mechanical ventilation before the incidence of asystole suggests a central component in the cardiovascular manifestations of envenomation. A. amoreuxi venom was selected as a model for the pharmacokinetic and quantitative toxicological studies since it has no effect on body temperature. In hyperthermic rabbits injected with labelled lethal fraction of A. amoreuxi venom, there was a significant decrease in the elimination half-life, t1/2 beta, the apparent volume of the tissue compartment, Vt, the apparent volume of distribution, Vdss, and the intercompartmental rate constant, kCT. Hypothermic rabbits showed a significant decrease in the apparent first-order elimination rate constant, kd, and a significant increase in the elimination half-life. In both states a higher concentration of the lethal fraction in the blood was calculated. This would explain the rapidity of onset of the electrocardiographic effects and the decreased survival time in both the hyperthermic and hypothermic rabbits injected with venom when compared to normothermic animals. The s.c. LD50 in mice and the i.v. MLD in rats were significantly reduced in the hypothermic mice and hypothermic and hyperthermic rats.

Animals↗
PubMed1990

Dexamethasone treatment attenuates the development of ischaemic brain oedema in gerbils.

Transient global forebrain ischaemia was produced in Mongolian gerbils by occluding both common carotid arteries for 10 min followed by 48 h recirculation. Dexamethasone, 5 mg/kg i.p., was given 5 h before the occlusion and every 12 h thereafter. After occlusion an increase in water, sodium and calcium content was found in the parietal cortex and hippocampus, while the concentration of potassium decreased. Exudation of plasma albumin was not found in the brain. The activity of Na+, K(+)-ATPase decreased in the hippocampus. Morphological signs of cerebral oedema were also observed, both in the CA1 region of the hippocampus and in the cortex. Dexamethasone treatment prevented the accumulation of water, sodium and calcium in the ischaemic brain. It also attenuated the oedematous morphological changes of the blood-brain barrier. Thus dexamethasone treatment may also have therapeutic relevance in the acute, high-risk phase of patients suffering from repetitive, transitoric cerebral ischaemia.

Animals↗
PubMed1989

Effect of roasting and autoclaving on phytic acid content of chickpea.

Chickpea cultivars CM-68, C-44, Kabuli, CM-72 and 6153 were analysed for phytic acid, phytate phosphorus and total phosphorus. The effect of roasting and autoclaving on these constituents of whole seed and cotyledons was determined. The data revealed that roasting and autoclaving significantly decreased (P less than 0.05) the phytic acid of chickpea cultivars. Phytic acid of whole seed was reduced to a range value of 16-60% and 16-64% by roasting and autoclaving respectively depending upon the cultivar. In the cotyledon, the phytic acid was reduced to a range value of 32-68% and 18-68% during roasting and autoclaving respectively. Similar effect of these treatments was observed in phytate phosphorus however, total phosphorus was little affected.

Cooking↗
PubMed1989

An evaluation of the BIOSELF 110 fertility indicator.

The BIOSELF 110 is a hand-held, non-invasive electronic instrument that measures basal body temperature and cycle length, and automatically identifies the fertile and infertile phases of the menstrual cycle with flashing red light and green light signals, respectively. The device was evaluated in 77 cycles from 33 ovulatory women in Kuala Lumpur, Malaysia. Ultrasound monitoring of maximum follicular diameter (MFD) and urinary LH measurements with Ovustick were used as reference methods to estimate the time of ovulation and the fertile period. Based on the MFD day, the BIOSELF correctly identified the entire fertile period, and at least four fertile days, in 89% and 94% of the cycles studied, respectively. The mean duration of the fertile period as determined by the number of flashing red light days was 11.0 days (SD 2.9). The device correctly identified the onset of the postovulatory infertile phase in 94% of cycles, with a mean duration of about 10 (green light) days. The results were similar using the LH peak day as the reference method. The mean interval from the onset of the fertile period (first flashing red light day) to the MFD day was 6.9 days (SD 2.6), and from the MFD day to the end of the fertile period, 3.1 days (SD 2.2). The BIOSELF 110 showed itself to be a reliable device for identifying the fertile and infertile phases of the menstrual cycle and, thus, should be a useful aid for couples seeking pregnancy. Prospective clinical trials are underway to assess the contraceptive effectiveness of the device.

Adult↗
PubMed1989

[Colorectal cancers in young adults: the reasons for poor prognosis].

Over an 18-year period, 2,600 patients were treated for colorectal carcinoma in the Montpellier Cancer Institute. Of the 93 patients younger than 40 years of age (3.6%), 78 records were retrospectively studied. The overall 5-year survival rate was 30%. Their survival was not significantly affected by the site of the primary tumor, the degree of tumor differentiation, or sex. The only significant parameter was Dukes staging at presentation (p less than 0.0001). An analysis of sites of recurrence revealed the frequency of liver metastases, ovarian metastasis in women, and local recurrence of rectal cancer. Although the high failure rate in these areas clearly justifies aggressive combined therapy, the high frequency of inaugural Stade D patients (27%) and their short mean survival time (5 months), underline the crucial importance of early detection. However, it is unfortunate that colorectal cancer screening in young patients is difficult because of the low rates of precancerous states (4%).

Adult↗
PubMed1988

Colorectal carcinoma in patients younger than 40 years of age. Montpellier Cancer Institute experience with 78 patients.

During an 18-year period, 2600 patients were treated for colorectal carcinoma in the Montpellier Cancer Institute. Of the 93 patients younger than 40 years of age (3.6%), 78 records were retrospectively studied. The overall 5-year survival rate was 30%. Their survival was not significantly affected by the site of the primary tumor, the degree of tumor differentiation, or sex. The only significant parameter was Dukes' staging at presentation (P less than 0.0001). An analysis of sites of recurrence revealed the frequency of liver metastasis, ovarian metastasis in women, and local recurrence of rectal cancer. Although the high failure rate in these areas clearly justifies aggressive combined therapy, the high frequency of inaugural Stage D patients (27%) and their short mean survival time (5 months), underline the crucial importance of early detection. However, it is unfortunate that colorectal cancer screening in young patients is difficult because of the low rates of precancerous states (4%).

Adenocarcinoma↗
PubMed1988

Effect of smokeless tobacco on the development of the CD-1 mouse fetus.

The objective of this study was to examine the effect of smokeless tobacco (ST) on the development of the CD-1 mouse fetus. ST was administered continuously via Alzet osmotic minipumps during the critical gestational days 7-14 and 6-13. Two ST dosages were administered, 3.2 mg/ml (Dosage I) and 6.4 mg/ml (Dosage II), which yielded plasma nicotine levels within the range comparable to those of an average ST user or smoker (36.0 ng/ml). Plasma nicotine levels were maintained in the range of 29.4 +/- 4.8 ng/ml to 44.3 +/- 16.0 ng/ml for the Dosage I group of dams, and in the range of 34.6 +/- 10.9 ng/ml of 75.5 +/- 19.9 ng/ml for the Dosage II group of dams. The main effect on the fetus was weight reduction, with Dosage I producing a tendency toward weight reduction (p = .08). Dosage II produced a significant 8.6% weight reduction from normal (p less than .0001) and an increase in fetal deaths (p less than .03). Dosage I produced an increase in the incidence of hemorrhages and supernumerary ribs, and a significant delay (p less than .05) in ossification of the supraoccipital bone, the sacrococcygeal vertebrae, and the bones of the forefoot and hindfoot. There were no significant differences between placental weights. Weights of dams were significantly reduced only at the higher ST exposure levels. We conclude that at plasma nicotine levels comparable to those of an average ST user, ST produces weight reduction, delayed ossification, and increase in hemorrhages and fetolethality in the CD-1 mouse fetus.

Animals↗
PubMed1988

Are the toxicological effects of scorpion envenomation related to tissue venom concentration?

The pharmacokinetics of 125I-labelled Androctonus amoreuxi venom and its lethal fraction was studied in rabbits. Comparative pharmacokinetic studies of labelled A. amoreuxi, Leisurus quinquestriatus and Buthotus judaicus venoms were carried out in guinea-pigs. The pharmacokinetics of A. amoreuxi venom was also studied in rats. Groups of rats were injected with labelled A. amoreuxi venom and killed at frequent time intervals for the determination of the relative tissue venom concentration as a function of time. Several groups of rabbits were injected with A. amoreuxi venom and serial blood samples withdrawn at time intervals comparable with those used in the pharmacokinetic studies for the determination of serum glucose, insulin, cortisol, total proteins, albumin, globulins, cholesterol, total bilirubin, urea, uric acid, bicarbonate, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, sodium, potassium, calcium and phosphorus. The packed cell volume, and total and differential leucocyte counts were also determined. In another series of experiments continuous monitoring of the electrocardiograms of rabbits following venom injection was made to correlate any abnormalities with tissue venom concentration. All three venoms and the lethal fraction showed an open two-compartment behaviour with rapid distribution half-lives ranging between 4 and 7 min and overall elimination half-lives of 4.2 to 13.4 hr. The behaviour of A. amoreuxi venom was not markedly different in the three species of animals used. In a given species (guinea-pigs) the behaviour of the three venoms was not markedly different. Correlation of the ECG changes with cardiac venom concentration showed that arrhythmias and infarction occurred at times when cardiac concentration was very low, indicating that the cardiac abnormalities might result from indirect factors. Comparison of the course of the biochemical changes with venom concentration in the central compartment indicated that the site of action of the venom is not located in the central compartment. Correlation of the intensity of the biochemical effects with venom concentration in the peripheral compartment revealed an apparent delay in the onset and peak of action. This was explained by assuming that the tissue compartment could be divided into a rapidly accessible and a slowly accessible compartment with the venom acting through the slowly accessible compartment. There was also the possibility of the venom acting indirectly through the release of other substances or transformation to an intermediate.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗