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Biomedical subjects

M Hasan

Publications and source records attributed to M Hasan.

At least 145 records · Page 8Linked to original sources

Zinc, copper and lead levels in blood, spinal cord and different parts of the brain in rabbit: effect of zinc-intoxication.

The effect of zinc (8 mg/kg body weight, intraperitoneally) administration daily for 7 consecutive days was studied on the levels of Zn++, Cu++ and Pb++ in the blood, spinal cord and different regions of the brain in rabbits. It was found that with increase in Zn++ concentration there was a decrease in copper levels and an increase in lead levels in almost all parts of the brain. In the blood, both copper and lead levels were significantly decreased. No definite mechanism for the changes can be postulated. The study suggests that changes of Zn++ concentration beyond physiological limits can affect the concentration of other essential and non-essential metal ions.

Animals↗

Misguided wire.

Explore the source record for details and available documents.

Adult↗

The factors determining success or failure of cimetidine treatment of peptic ulcer.

Why a substantial proportion of peptic ulcers fails to heal in clinical trials of drugs remains uncertain. We therefore made a prospective study of biological and social factors which might influence healing. 160 patients who were treated with cimetidine for various types of peptic ulceration were grouped into successes or failures by serial endoscopic review. There were 80 patients in each group. Significant differences between the two groups emerged. The mean age and mean age of onset of symptoms were lower in the failure group. The proportion of manual workers and artisans, the frequency of family history of peptic ulcer, the proportion of smokers, alcohol users, analgesic takers, and the frequency of acid hypersecretion were all higher in the failure group. The "degree" of abuse of smoking, alcohol, and analgesics was also greater in the failures than in the successes. The proportional reduction of maximal acid output after a dose of cimetidine was not different between the groups.

Age Factors↗

Duodenal mucosal architecture in non-specific and ulcer-associated duodenitis.

This study was done to determine the severity and extent of abnormalities of duodenal mucosal architecture in non-specific (non-ulcerative) and ulcer-associated duodenitis. The effect of successful treatment with cimetidine on these changes has also been assessed. A method of microdissection and measurement of villus height, crypt depth, and mitotic figure count per crypt was applied to endoscopic biopsies from the duodenum. Five groups of patients were studied: untreated ulcer-associated duodenitis, untreated non-specific duodenitis, healed ulcer-associated and non-specific duodenitis after cimetidine treatment, and controls. Significant reduction in villus height, increase in crypt length, and increase in mitotic figure count per crypt were all found in both ulcer-associated and severe non-specific duodenitis as compared with controls. These changes were localised to visually inflamed areas and regressed after healing of these lesions with cimetidine. This is the first quantitative comparison of the architectural features between diseased states in the duodenum and control in the same study. Identical morphological changes in the form of crypt hyperplasia and villus atrophy were demonstrated in areas of non-specific and ulcer-associated duodenitis. No evidence could be found from this study that non-specific duodenitis constitutes a different disease from ulcer-associated duodenitis.

Cimetidine↗

Measurements of intestinal villi non-specific and ulcer-associated duodenitis-correlation between area of microdissected villus and villus epithelial cell count.

Measurements of villus height, villus area, together with counts of epithelial cells in individual villi, were performed on endoscopic duodenal biopsies from five groups of patients: controls, ulcer-associated duodenitis, mild and severe non-specific (non-ulcerative) duodenitis, cimetidine healed ulcer-associated duodenitis and cimetidine healed non-specific duodenitis. The objectives of the study were two-fold: to establish if epithelial cell count correlated with simpler measurements of villus height or area; and to compare the findings in ulcer-associated and in non-specific duodenitis. Villus area correlated well with epithelial cell count per villus (r = 0.96); villus height correlated less well (r = 0.66). When compared with controls, there was a significant decrease in the epithelial cell count per villus in ulcer-associated and severe non-specific duodenitis, but this was confined to the visually inflamed area of the duodenal bulb. After healing of inflammation with cimetidine villus height, area, and epithelial cell count returned to values similar to those in controls. This study confirms that the effects of ulcer-associated and severe non-specific duodenitis on duodenal villi are identical.

Cell Count↗

Organophosphate pesticide dichlorvos-induced increase in the rate of lipid peroxidation in the different regions of the rat brain: supporting ultrastructural findings.

Commonly used organophosphate pesticide dichlorvos is known to cause neurologic lesions. However, the exact mechanism of its neurotoxicity is, as yet, unclear. Using dose-dependent inhibition of acetylcholinesterase activity as an index of its neurotoxicity, effects of three different doses of dichlorvos (0.6 mg, 1.5 mg, and 3.0 mg/kg body weight i.p. daily for 10 days) have been observed on the rate of lipid-peroxidation in the cerebrum, cerebellum and brain stem of albino rats. Simultaneously, electron microscopic study of the dichlorvos intoxicated rat cerebellum was also carried out. Dose-dependent increase in the rate of lipid peroxidation was found in all the brain regions, and increased incidence of lipofuscin-like pigment granules was discernible in the Purkinie cells of the cerebellar cortex.

Acetylcholinesterase↗

Regional effects of sulfur dioxide exposure on the guinea pig brain lipids, lipid peroxidation and lipase activity.

Experiments to evaluate the neurochemical action of gaseous pollutants were performed in a specifically designed inhalation chamber. Exposure of guinea pigs to 10 ppm of SO2 for one hour daily for 21 days produced a significant depletion of total lipids and free fatty acids in all brain regions. Phospholipid and cholesterol content of the cerebellum and brain stem were also decreased, but were increased in cerebral hemisphere. Esterified fatty acids were depleted in the cerebral hemisphere and brain stem, but exhibited increment in the cerebellum. The rate of lipid peroxidation and the activity of lipase were increased significantly in all the regions of the brain. The results clearly indicate that SO2-exposure induces degradation of brain lipids. Interestingly, the lipid contents are affected differentially in the various parts of the brain.

Animals↗

Effects of an organophosphate (dichlorvos) on open field behavior and locomotor activity: correlation with regional brain monoamine levels.

Dichlorvos (O,O-dimethyl-2:2-dichlorovinyl phosphate) was administered IP (3 mg/kg) daily for 10 days to a group of albino rats. Open field behavior was significantly depressed below the mean of the control group. On day 7, ambulation was reduced to 24% of the mean but recovered to 60% on day 10. Similarly, rearing response was decreased on day 7 and showed a fast recovery on day 10 but the preening response further declined on day 10. Defecation, on the contrary, was suppressed to 0% on day 7 and showed complete recovery on day 10. Motor activity showed a significant depression and fine movements were reduced more than gross movements in the second phase. Dopamine was significantly decreased on days 5 and 7 but showed a 13% recovery in the brain stem on day 10. Norepinephrine was significantly reduced in the cerebral hemisphere while serotonin was decreased both in cerebral hemisphere and brain stem. Neither of thse two amines showed significant recovery on day 10. Interesting concordance of the open field behavioral changes with the levels of dopamine, norepinephrine, and serotonin in the various regions of the rat brain was noticeable and has been discussed.

Animals↗

Microanalysis of lipids in discrete brain areas of the rabbit following intramuscular administration of steroid contraceptive.

The effects of 60- and 90-day administration of a pill containing 0.05 mg ethinylestradiol and 0.5 mg norgestrel on the regional lipid levels of female albino rabbit brains have been investigated. Decreased levels of total lipids, phospholipids, cholesterol, free fatty acids and esterified fatty acids were observed in hypothalamus, hippocampus, amygadaloid nucleus, midline nuclei of thalamus and gyrus cinguli. However, the levels of esterified fatty acids only in the amygdaloid nucleus and that of cholesterol in hypothalamus were significantly increased.

Animals↗

Comparison of maximal acid output and gastrin response to meals in Chinese and Scottish normal and duodenal ulcer subjects.

Maximal acid output (MAO) after pentagastrin stimulation and gastrin response to a standard meal was studied in 100 control and 200 duodenal ulcer subjects from each of two ethnic groups, Scots and Chinese. The acid output was significantly higher in the Scots than in the Chinese for both controls and duodenal ulcer patients. Despite correction for differences in body stature by expressing MAO as a function of the body weight, these differences persisted. In 45 pairs of closely matched patients with duodenal ulcer, the differences between the two ethnic groups remained significant, irrespective of whether MAO was expressed in absolute or weight corrected values. This indicates that differences in age, sex, family history, or duration of illness did not account for differences in acid output. In 20 pairs of normal control and 45 pairs of duodenal ulcer patients the fasting and post-prandial serum gastrin levels did not differ, significantly between the two ethnic groups. The proportion of acid normosecretors was significantly higher in the Chinese duodenal ulcer patients than in the Scottish. The reason for these differences in the gastric acid output between the two ethnic groups is not known and needs to be studied further.

Adult↗