Biomedical subjects
Publications and source records attributed to M Hasan.
A population based epidemiologic study carried out in a lower socioeconomic suburb of Karachi, identified 23 children with epilepsy among 994 children (3-9 year old) surveyed for childhood disabilities. Nineteen had major epilepsy, 2 petitmal and one each had focal motor and myoclonic attacks. The high frequency of epilepsy may be due to consanguinity, central nervous system, infections and birth and accidental trauma.
In a population survey, the point prevalence of duodenal ulcer disease (DUD) was found to be 11.98 percent which is the highest prevalence rate so far reported in the literature. The prevalence of duodenal ulcer dyspepsia in the first degree relatives of groups of subjects with proven duodenal ulcer, non ulcer dyspepsia (NUD) (duodenal ulcer dyspepsia but without evidence of ulcer at endoscopy) and normal healthy control (HC), all matched by age and sex and all from the population with the high prevalence of duodenal ulcer disease, were studied. Both DUD and NUD subjects had a significantly higher family history of duodenal ulcer dyspepsia than the control subjects.
Monoamine levels, MAO activity and neurobehavioral perturbations were studied in albino rats intoxicated with Dimecron i.e., phosphamidon (2.0 mg/kg b wt, ip x 7 days). Open field behaviour (OFB) of the rats was examined thrice a day for seven days. Significant depletion in DA, NE and 5-HT, and enhancement of MAO were found in various regions of the central nervous system (CNS) on the 7th day. Daily decrease was observed in ambulation, rearing and preening responses, with maximum decrement on the seventh day of Dimecron intoxication.
Fifteen human cerebral cortical biopsies from children treated for hycrocephalus by shunt operation and one non-hydrocephalic "control" biopsy specimen were studied by electron microscopy. Marked differences between the ultrastructural features of oligodendrocytes and microgliacytes in the maturing and hydrocephalic material and the ultrastructure of control and adult specimens were seen. Proliferation of oligodendrocytes was commonly discernible. Microgliacytes exhibiting plesomorphic vacuoles and bundles of microfilaments were often observed.
We report the results of a randomized controlled trial of intravenous streptokinase in a subset of patients with unstable angina. Seventy-six patients were admitted with prolonged (more than 20 minutes) angina at rest of less than 3 weeks onset. Fifty-two patients continued to have more than 3 episodes of prolonged angina in 48 hours on medical therapy with metoprolol, isosorbide dinitrate, nifedipine and intravenous nitroglycerin. Forty-eight patients consented to enter the study and were randomized into two groups. The first group, of 24 patients, received 1.5 million units of streptokinase infusion and the second group, also of 24 patients, received a placebo. Pain relief within 48 hours was achieved in 19/24 (79.1%) patients after streptokinase infusion as compared to 9/24 (37.5%) of the controls (P less than 0.05). Approximately 90% (17/19) of patients responding to streptokinase therapy were relieved of chest pain within the first six hours as against none in the controls. The incidence of acute myocardial infarction within six months was 12.5% (3/24) in those receiving streptokinase and 25% (6/24) in the controls. Mortality at six months stood at 8.33% (2/24) in the treated patients and 16.6% (4/24) in the controls. Intravenous streptokinase thus appears to be of benefit in patients with angina at rest of recent onset which does not respond to conventional medical therapy.
A study was carried out on the effect of gentamicin on the central auditory pathway in rats. Rats were administered graded doses of gentamicin (60 mg, 100 mg and 160 mg/kg b.wt., i.m.) daily for 21 days. Levels of total lipids, phospholipids and cholesterol showed dose related increment in the central auditory pathway. On the other hand, the rate of lipid peroxidation was inhibited in all regions of the central auditory pathway of the rat.
Light microscopic study of different body organs of cat-fish following exposure to HgCl2 0.2 mg/L in water for 30 days revealed that focal degeneration of liver cells and disorganization of hepatic cords occurred at places. Furthermore, centrilobular atrophy and compensatory hypertrophy of some hepatic cells were also observed. In the kidneys disintegration of renal epithelium along with displacement of nuclei, shrinkage of glomeruli, breakdown of Bowman's capsule and heavy infiltration by inflammatory cells were observed. The histopathological changes noted in the intestine included degeneration of lining epithelium, and diminution of goblet cells. Microscopic section of ovaries exhibited reduction of ooplasm leading to formation of atypical oocytes. An increase in the occurrence of atretic oocytes and interfolicular spaces was also discernible. No histopathological lesions could be detected in testes of male fish probably because of the difference in the maturity of the control and experimental groups. The pathomorphological alterations in relation to mercury toxicity in spleen were associated with the disorganization of the splenic cords resulting in the displacement of lymphatic tissue cells within the substance of splenic pulp. Marked depletion of the red pulp was noticeable.
This study was undertaken to investigate the effect of nitrogen dioxide on some neurochemical parameters. Guinea-pigs were exposed to NO2, 5 p.p.m. and 10 p.p.m. for 2 hr daily for five weeks. The results showed significant depletion of the total lipids and phospholipids content of the cerebral hemisphere, cerebellum, midbrain and spinal cord following nitrogen dioxide intoxication. The results further revealed significant diminution in the cholesterol content of the NO2 intoxicated animals in cerebral hemisphere, cerebellum and midbrain. But on the other hand the level was significantly enhanced in the spinal cord. Interestingly, the rate of lipid peroxidation was found enhanced in all the investigated brain areas, and with increasing dosage the effect was correspondingly pronounced.
Phosphamidon was detected by thin-layer chromatography (TLC) from various CNS regions of the rats intoxicated with three doses (1.0, 1.5 and 2.0 mg/kg body-weight) intraperitoneally daily for seven days. A distinct dose-related increase in its concentration was observed in all investigated areas of the CNS. Regions with higher gray matter composition showed greater uptake of phosphamidon compared to those rich in white matter. This is in accordance with our previous study (Naqvi et al. 1988) revealing similar pattern in the effect of phosphamidon on the phospholipids in the brain.
The flowers of Inula grantioides collected from the vicinity of University of Sindh, Jamshoro Campus, Pakistan were analysed for their fatty acid composition. The fatty acids were converted into methyl esters and identified by gas liquid chromatography-mass spectrometry as myristic, pentadecanoic, palmitic, margaric stearic, arachidic, behenic, tricosoic, lignoceric, hexadecanoic and heptacosoic acid.
An electron microscopic study has been made of the perivascular cerebral pericytes and juxtavascular phagocytes in the human cerebral cortex. Biopsies from 16 hydrocephalic children and one 4-year-old normal child were analyzed. Pericytes showed vesicular transport demonstrating pericyte brain barrier alteration in hydrocephalus, which might help in the resolution of edema. Aggregation of vesicles, so obvious in the hydrocephalic material, was not seen in the control pericytes. Intercapillary channel (bridge) was seen in one instance. Phagocytic cells containing lipid vacuoles cellular debris and lysosomes were often observed in the vicinity of the microvasculature of the hydrocephalic biopsies. Occasional separation of a phagocytic pericyte from the vessel wall suggests that some juxtavascular phagocytes may be derived from pericytes.
Four of 30 human cerebral cortex biopsies from infants ranging from four days to about ten years treated for hydrocephalus by shunt operations are described paying special attention to the vascular structures. The biopsy specimens were studied in semi-thin and ultrathin sections. Attention is drawn to the role of pinocytotic vesicles found in capillaries and smaller vessels as a possible transcellular route for the hydrocephalic oedema resolution. No intercellular dehiscences or the so called blisters were observed. With the passage of time, the number of membrane bound vesicles increased and arrays of pinocytotic vesicles were discernible both on the abluminal as well as luminal aspect of the capillary wall. Additionally, larger vacuoles containing electron-dense material, apparently undergoing autolysis, were also detected. The basal lamina was of uneven thickness and at places duplicated. Hypertrophic pericytes exhibited remarkable oedamatous changes, increased vesicular or vascular transport, demonstrating pericyte brain-barrier dysfunction. Swelling of the astrocytic end-feet bordering the capillaries was remarkable. These findings indicate that the CSF or oedema fluid is absorbed into the vascular system via a transendothelial pathway.
The effect and choice of a drug to control heart rate for symptomatic improvement in patients with isolated mitral stenosis with normal sinus rhythm (n = 10) or atrial fibrillation (n = 10) were studied. Digoxin (0.25-0.5 mg daily), metoprolol (50-100 mg twice a day) and verapamil (40-80 mg three times a day) were evaluated for this purpose. An open randomised cross-over design was followed. The efficacy of a drug was evaluated by: (1) subjective improvement on a visual analog scale, and (2) objective improvement on repeated multi-stage symptom-limited treadmill exercise. In patients with sinus rhythm greater than or equal to 50% subjective improvement was seen in 90%, 40% and nil with metoprolol, verapamil and digoxin, respectively. The total work done by these patients was 1008 +/- 541 kpm (control), 2869 +/- 1418 kpm on metoprolol, 2369 +/- 884 kpm on verapamil and 1654 +/- 918 kpm on digoxin. In patients with atrial fibrillation greater than or equal to 50% subjective improvement was seen in 80%, 40% and 30% with verapamil, metoprolol and digoxin, respectively. The total work done by these patients was 555 +/- 232 kpm (control), 1379 +/- 553 kpm on verapamil, 1251 +/- 575 kpm on metoprolol and 716 +/- 340 kpm on digoxin. The degree of improvement on a drug appeared to be a function of its ability to control resting and exercise heart rates in two different rhythms in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)
The caudal part of the fourth ventricle in adult rhesus monkeys, of both sexes, revealed the area postrema (AP) to be composed of bilateral spindle-shaped elevations located ventromedial to the gracile tubercles. Supraependymal (SE) elements, comprised of SE cells and/or fibre processes could be seen near the medial margin of a narrow oligociliated strip separating the nonciliated AP from the profusely ciliated vagal triangle (VT). In general, these consisted of multilobed ganglion-like cell clusters interconnected by fasciculated fibre processes with varicosities along their lengths. Thinner processes radiating from the cell clusters and varicosities traversed towards the VT for short distances and often appeared to penetrate the underlying ependyma. The thicker fibre processes which exhibited a fasciculated configuration extended between raised nodule-like areas in the ventricular floor. The majority of such areas exhibited an uneven surface due to the presence of numerous membranous folds over them. Near the periphery of nodular areas as well as along the fasciculated fibre processes interconnecting them, a few bouton-like protrusions were discernible. The SE elements observed in the caudal portion of the fourth ventricular floor are suggestive of comprising some integrative pathways between the ventricular cerebrospinal fluid and subependymal functional centres in the vicinity of the AP, a circumventricular organ having diverse functions.
The effects of mercuric chloride (HgCl2) on lipid profiles and lipid peroxidation in different body organs of fresh water cat-fish Heteropneustes fossilis were studied. The daily exposure of HgCl2 0.2 mg/L for 10, 20 and 30 days depleted the total lipids in brain. But the content of phospholipids enhanced significantly at 30 days. Significant diminution in C/P ratio was discernible with 30 days of exposure following mercury toxicosis. Liver exhibited elevated levels of total lipids, phospholipids, cholesterol and C/P ratio. Interestingly kidney showed marked decrease in the concentration of total lipids, cholesterol and C/P ratio at higher exposure. However, the phospholipid values increased during the longer exposure. The content of total lipids and phospholipids was high in muscle but the level of cholesterol and C/P ratio were depleted. Significant increment in lipid peroxidation was discernible in brain, liver and muscle. In kidney the rate of lipid peroxidation was significantly reduced. The results suggest that exposure of HgCl2 enhances the peroxidation of endogenous lipids in brain, liver and muscle. Interestingly the lipid contents are affected differently in different body organs.
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Groups of rats were administered thallous acetate 5 mg/kg or acetyl-homocysteine-thiolactone (citiolone) 8 mg/kg body weight, i.p. daily for 6 days. A third group of rats received the same doses of both thallium and citiolone for 6 days. Total sulfhydryl radicals and glutathione content were estimated in the cerebral hemisphere, cerebellum and brain stem. The results were analyzed using Student's t test and 'ANOVA'. Glutathione decreased in all the brain regions with the greatest loss in the brain stem. Total sulfhydryl (SH) radicals were significantly depleted only in cerebellum and brain stem. The reduction of total SH radicals did not occur when citiolone and thallium were administered concurrently. Glutathione levels were protected by citiolone but were not returned to control levels.