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Biomedical subjects

R Husain

Publications and source records attributed to R Husain.

At least 37 records · Page 2Linked to original sources
PubMed1993

Perinatal effects of two pyrethroid insecticides on brain neurotransmitter function in the neonatal rat.

The influence of 2 synthetic pyrethroid insecticide formulations, ie 10 mg fenvalerate/kg bw and 15 mg cypermethrin/kg bw, given during gestation and lactation periods to pregnant and nursing dams by gavage in corn oil on the morphological development and neurochemical indices was studied in neonatal rats. Exposed pups showed a significant increase in the levels of dopamine and muscarinic receptors of striatal membrane in both treatment groups. Alterations in these parameters were more marked in lactationally exposed pups. These pups also showed a significant decrease in the activity of brain monoamine oxidase and Na+, K(+)-ATPase and a significant increase in acetylcholinesterase from gestational exposure to fenvalerate. Significant decreases were observed during lactation in monoamine oxidase and acetylcholinesterase in fenvalerate-exposed pups and in acetylcholinesterase and Na+, K(+)-ATPase in cypermethrin-exposed pups. These results suggest disturbances in dopaminergic and cholinergic pathways which are more pronounced during the "growth spurt" period and may lead to a functional delay in brain maturation.

Acetylcholinesterase↗
PubMed1992

Protein malnourishment: a predisposing factor in acrylamide toxicity in pregnant rats.

Exposure to acrylamide (3-10 mg/kg body weight) was found to be lethal for protein-deficient pregnant rats as evidenced by their increased mortality. It had no such effect on the normal protein diet fed pregnant and nonpregnant rats and the protein-malnourished nonpregnant rats. Protein deficiency during pregnancy caused a significant decrease in the activity of brain monoamine oxidase and acetylcholinesterase and striatal [3H]spiperone binding, known to label dopamine receptors; had no significant effect on the binding of 3H-QNB (quinuclidinyl benzilate) to cerebellar and [3H]diazepam to frontocortical membranes, known to label muscarinic and benzodiazepine receptors, respectively; and had no significant effect on brain glutathione (GSH) levels in comparison with pregnant rats fed normal protein diet. Exposure to acrylamide (2 mg/kg body weight) in protein-malnourished pregnant rats caused a marked decrease in the activity of monoamine oxidase and acetylcholinesterase and also in the binding of [3H]spiperone, [3H]QNB, and [3H]diazepam to striatal, cerebellar, and frontocortical membranes, respectively. Kinetic studies revealed that decreased binding of these ligands in the specific brain regions were due to decreased receptor sites (Bmax). A reduction in the brain glutathione content was also observed in these animals in comparison with those fed a low-protein diet during pregnancy. Pregnant rats fed a normal-protein diet on acrylamide exposure, however, showed no such biochemical changes in comparison with the pregnant rats fed normal protein diet. Also, no effect on any of the parameters studied was observed in the adult nonpregnant rats fed a low-protein diet (for 18 d) and those exposed to the monomer (d 6-17) fed either a normal- or low-protein diet in comparison with respective controls. The results indicate that pregnancy under conditions of malnutrition modifies the susceptibility of pregnant rats toward acrylamide.

Acetylcholinesterase↗
PubMed1991

Effect of dibutyltin dilaurate on regional brain polyamines in rats.

Administration of dibutyltin dilaurate (DBTL; 0, 20 or 40 mg/kg body wt.) by gavage to rats for 3 consecutive days produced a significant increase in polyamine levels in selected brain areas. At the higher dose of DBTL (40 mg/kg) spermidine levels were raised in pons-medulla, hypothalamus and frontal cortex while spermine levels increased in pons-medulla, hippocampus and frontal cortex regions. At the lower dose (20 mg/kg) only a slight increase in polyamine levels occurred. The observed induction in regional brain polyamines in DBTL-treated rats may lead to disturbances in synaptic function and further enhance its neurotoxic potential.

Animals↗
PubMed1991

Reduction of phosphoinositides and diacylglycerol levels in repeatedly dibutyltin-dilaurate-treated rat brain.

Oral administration of a single dose of dibutyltin dilaurate (DBTL, 80 mg/kg body wt.), 2 or 24 h after treatment, caused no significant change in the levels of diacylglycerol and phosphoinositides in rat cerebrum (forebrain), whereas daily administration of DBTL (40 or 80 mg/kg body wt.) for 3 days (24 h after the final treatment) decreased the levels of diacylglycerol and phosphoinositides (phosphatidylinositol, phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate) in a concentration-dependent manner without influencing the levels of phosphatidylcholine in rat cerebrum. These studies indicate impairment of the phosphoinositide messenger system in rat cerebrum following repeated exposure to DBTL.

Animals↗
PubMed1991

Neurotoxicological effects of a pyrethroid formulation, fenvalerate in rats.

The effect of systemic treatment of a synthetic pyrethroid insecticide, fenvalerate (FV) was examined in adult female rats at different doses i.e. 5, 10, 20 mg/kg body weight by gavage for 21 consecutive days on regional brain levels of noradrenaline (NA), dopamine (DA), their acid metabolites: dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) by HPLC-EC system. Our results demonstrate pronounced inhibition of NA, DA, HVA & DOPAC levels in several brain regions which were neither dose related nor region specific.

Animals↗
PubMed1990

Effects of fasting during Ramadan on urinary excretion in Malaysian Muslims.

Urine analysis was conducted on male Muslims before, during and after Ramadan. Various changes in urine volume, osmolality, total solute, sodium, potassium, titratable acidity and urea in response to altered feeding and activity regimens were found. There were no detectable levels of ketones, protein, glucose, urobilinogen and haemoglobin. It was concluded that the body adapted to fasting during Ramadan and that there were no adverse effects on renal function.

Acids↗
PubMed1990

Ventilatory function in Malay Muslims during normal activity and the Ramadan fast.

Pulmonary function parameters were examined in a Malay Muslim population during normal activity and Ramadan fasting conditions. The validity of employing various lung function prediction formulae for the subjects was also assessed. Present findings indicate that the water deprivation regime and resultant dehydration during Ramadan did not cause significant changes in ventilatory functions. Although pulmonary prediction formulae based on Caucasian and African populations were inapplicable to the subjects examined, the equations derived from the neighbouring populations in Singapore could be employed.

Adult↗
PubMed1989

Effect of altered eating pattern on serum fructosamine: total protein ratio and plasma glucose level.

The effect of alteration of eating pattern during Ramadan on body mass index (BMI), serum fructosamine: total protein ratio (F/TP), and glucose level in 18 healthy male Asiatic Moslems were studied. The results showed a significant decrease (p less than 0.025) in F/TP at the second week of Ramadan in 11 subjects who experienced continuous decrease in BMI throughout Ramadan. The remaining 7 subjects showed no significant changes in BMI and F/TP. No evidence of hypoglycaemia was observed in the subjects during the study. Serum fructosamine: total protein ratio in subjects with altered eating pattern preferably should be interpreted along with the change in body mass index.

Adult↗
PubMed1988

Influence of di-butyltin dilaurate on brain neurotransmitter systems and behavior in rats.

Exposure to DBTL (20, 40 or 80 mg/kg body weight) caused a decrease in levels of noradrenaline (NA), dopamine (DA) and serotonin (5-HT) at all treatment levels. Hypothalamus and frontal cortex appeared to be most affected, since levels of all the three amines examined showed changes in these areas. Maximum decrease of DA was found in corpus striatum, NA in pons medulla and of 5-HT in frontal cortex. These animals also showed a decrease in spontaneous locomotor activity and learning at all the doses. The data indicates involvement of hypothalamus and frontal cortical regions of the brain in the neurotoxicity of DBTL.

Amphetamine↗
PubMed1988

Low protein diet modifies acrylamide neurotoxicity.

The present study deals with the role of protein deficiency in the neurobehavioural effects of acrylamide in rat pups exposed during pregnancy and early infancy. The data indicated that acrylamide could be more toxic in protein-deficient hosts as it significantly decreased the dopamine and benzodiazepine receptor binding and delayed the development of reflexes and land marks in these pups.

Acrylamide↗
PubMed1987

Effects of fasting in Ramadan on tropical Asiatic Moslems.

1. Anthropometric variables, resting heart rate and respiratory gas exchange were measured in twelve male and nine female Asiatic adult Moslems during the month of Ramadan, the week before and the month after Ramadan. 2. Energy intakes were estimated from dietary recall during fasting and non-fasting conditions. 3. Both male and female subjects experienced a decrease in body mass with the reduction in energy intake during fasting. Males experienced a greater reduction than females in resting heart rate; females lost more body-weight and subcutaneous fat than males. 4. Urine output and fluid intake were measured in twelve male subjects for 1 d during each week of fasting and 1 d during the pre-fasting control period. Among the subjects examined, the Ramadan regimen did not result in changes in the pattern of fluid exchange.

Adult↗
PubMed1987

A rationale for selecting suitable physiology topics for the basic sciences curriculum in dentistry.

The suitability of physiology topics taught in the first-year dental curriculum needs to be investigated in the light of the view of the present generation of clinical and preclinical teachers, and students. This was studied in the University of Malaya in order to propose a rational physiology curriculum with proper identification of priority topics. Oral physiology, blood and the cardiovascular system were found to be the most relevant for dental students. Among the systems, high and low priority topics were identified and their relative importance is discussed.

Attitude of Health Personnel↗