Cardiovascular reactivity in Malay Moslems during Ramadan

The investigation examined the possibility that observance of Ramadan by Moslems in Malaysia is associated with modification of circulatory parameters. Cardiovascular reactivity was investigated employing the cold hand immersion test as the stressor stimulus. Resultant data showed increased blood pressures and vascular resistance during Ramadan in the absence of cold stimulus while the magnitude of the maximal cardiac and vascular response to the applied stressor which served as indicators of reactivity was not affected by the Ramadan situation.

Neurobehavioral, neurochemical and electrophysiological studies in 6-hydroxydopamine lesioned and neural transplanted rats

Unilateral injection of 6-hydroxydopamine (6-OHDA) into the caudate nucleus of rat caused degeneration of dopaminergic terminals, evidenced by significant (P < 0.05) elevation of spontaneous and drug-induced motor behaviour, enhanced DA receptor binding and significant increase in the neuronal firing rate of caudate neurons, suggesting supersensitivity of dopaminergic receptors. Eight weeks following the transplantation of embryonic cell suspensions from caudate at the lesioned site, a significant restoration of the enhanced 3H spiperone binding and neuronal activity of caudate neurons was observed in comparison with lesioned rats. These results clearly demonstrate that transplanted embryonic neuronal tissue at the lesioned site is capable of restoring the neuronal deficits caused by 6-OHDA as evidenced by significant amelioration in neurochemical, behavioral and electrophysiological alterations.

Modulation of acrylamide-induced neurochemical and behavioral deficits by cerebellar transplants in rats

Acrylamide (30 mg/kg body wt.) administered intraperitoneally daily to young adult male rats, five times a week for 3 consecutive weeks, affected the cerebellar functions, as exhibited by a significant reduction in rotarod performance, spontaneous locomotor activity, glutathione-S-transferase activity, and 3H-flunitrazepam binding in cerebellum. Transplantation of dissociated fetal cerebellar cells (E14) to cerebellum resulted in a significant recovery in behavioral and neurochemical parameters evaluated 9 weeks after transplantation. Light- and electron-microscopic studies confirmed the viability and specificity of cerebellar grafts.

Effect of protein malnutrition on the neurobehavioural toxicity of styrene in young rats

Neurotoxic effects of styrene on certain biochemical and behavioural indices were studied in young rats kept deficient in protein during the weaning period. Young rats fed a low-protein diet showed a significant decrease in the level of dopamine and an increase in frontocortical [3H]serotonin binding in comparison to the group of rats fed a normal protein diet. These rats also showed a significant increase in foot shock-induced aggressive behaviour, while no changes in amphetamine-induced locomotor activity, levels of norepinephrine and serotonin and binding of [3H]spiperone to striatal membrane were observed. On exposure to styrene, rats fed a normal protein diet showed a decrease in dopamine level and an increase in foot shock-induced aggressive behaviour only, with no significant change in other parameters, in comparison to the respective controls. It was, however, interesting to note that when rats fed a low-protein diet were exposed to styrene they showed a significant decrease in the levels of norepinephrine, dopamine and serotonin and an increase in the binding of [3H]spiperone and [3H]5-HT to striatal and frontocortical membranes, respectively. A significant increase in foot shock-induced aggressive behaviour and amphetamine-induced locomotor activity was also observed in this group of animals in comparison to those fed a low-protein diet. The biochemical and behavioural data indicate that protein deficiency makes young animals more vulnerable and it is an important predisposing factor in the neurobehavioural toxicity of styrene.

Acrylamide induced immunosuppression in rats and its modulation by 6-MFA, an interferon inducer

In the present communication, we describe acrylamide (ACR) induced immunotoxicity and its modulation by an interferon inducer, the 6th mycelial fraction acetone (6-MFA) of Aspergillus ochraceus ATCC 28706. ACR administration to rats produced a significant decrease in the weight of spleen (p < 0.001), thymus (p < 0.001) and mesenteric lymph nodes (p < 0.05). A decrease in cellularity of spleen (p < 0.001), thymus (p < 0.001), bone marrow (p < 0.001) and circulating blood lymphocyte population (p < 0.001) was also recorded. ACR suppressed the humoral as well as cell mediated immunity as assessed by erythrocyte antibody complement (EAC)-rosettes (p < 0.001), hemagglutination titre (p < 0.001), PFC (p < 0.001) and the delayed type hypersensitivity response against sheep red blood cells (SRBC, p < 0.001). ACR treated immunosuppressed rats when treated with 6-MFA restored the circulating lymphocyte number to the normal level and a partial recovery in the weight of spleen and thymus. Potentiation of EAC-rosettes, hemagglutination titre, IgM-PFC and DTH response against SRBC was observed. It is concluded that 6-MFA ameliorate the ACR induced toxicity. This study may be of significance in prevention of ACR toxicity.

Suppurative corneal ulceration in Bangladesh. A study of 142 cases examining the microbiological diagnosis, clinical and epidemiological features of bacterial and fungal keratitis

Suppurative keratitis is an important preventable cause of blindness, particularly in the developing world. This study analyses 142 cases of suppurative keratitis referred to Chittagong Eye Infirmary Bangladesh. Some 53.5% of cases were bacterial and 35.9% were fungal. The five most common pathogens were: Pseudomonas sp. 24%, Streptococcus pneumoniae 17%, Aspergillus sp. 13%, Fusarium sp. 7% and Curvularia sp. 6%. Gram stain and culture results were consistent in 62.6% of cases. Previous antibiotic treatment was a significant factor for failure of culture isolation and less so for Gram stain failure. On Gram stain, 55.9% of pseudomonal cases were missed, but only 2% of fungal cases were missed. Over all, Gram stain had a sensitivity of 62% and positive predictive value of 84% for bacterial cases, and 98% and 94% for fungal cases, respectively. Fungal ulcers were typically filamentous, but an antecedent history of trauma was not common. The most frequent injury was due to rice grains, but the inoculum appeared to be introduced during eye washing with contaminated water. Pseudomonal ulcers occurred most frequently in the monsoon season, and Fusarium cases were seen only in the hot, dry season.

Effect of deltamethrin on regional brain polyamines and behaviour in young rats

The present study examines the mechanism of neurotoxic action of a synthetic pyrethroid formulation deltamethrin in young rats. Newly weaned Wistar Albino male rats received deltamethrin of technical grade at a dose of 7.0 mg/kg body weight/day in corn oil, orally from postnatal day 22 to postnatal day 37. Deltamethrin significantly decreased the wet weight of the hippocampus without much affecting the weight of cerebellum, pons medulla, hypothalamus, frontal cortex and corpus striatum in comparison to respective controls. A significant increase in the activities of mitochondrial monoamine oxidase and microsomal acetylcholinesterase without any effect on microsomal Na+, K(+)-ATPase activity was observed in the brain of experimental animals. Our results further indicate that deltamethrin markedly impaired learning function and significantly increased the spontaneous locomotor activity while aggressive behaviour remained unaffected. An overall enhancement of polyamine levels in hypothalamus and corpus striatum accompanied with an overall decline in pon medulla and cerebellum was also noted. Maximum decrease of spermine and spermidine was registered in hippocampus, while these polyamines showed an increase in frontal cortex. In striatal membranes the binding of 3H-spiperone decreased and 3H-quinuclidinyl benzilate was elevated significantly. Deltamethrin-induced deviations in regional brain polyamine levels may be a possible cause for altered pathophysiology of the neurone.

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.

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.

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.

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.

Increased neurobehavioral toxicity of styrene in protein-malnourished rats

Influence of protein deficiency on the neurobehavioral toxicity of styrene during gestation and early infancy was studied in rats. Eye opening and fur growth were delayed in rat pups born to dams receiving a low protein diet. These pups also showed a delay in the development of surface and air righting reflexes and cliff avoidance response and a marginal increase in the levels of dopamine and serotonin receptors in comparison to those born to dams receiving a normal protein diet. Alterations in these parameters were more marked in pups born to dams exposed to styrene and receiving a low protein diet. In addition, these pups also showed a significant decrease in the activity of monoamine oxidase, Na+, K(+)-ATPase and succinic dehydrogenase as well as significant increases in motor activity and receptor sensitivity when compared to rat pups born to dams receiving a low protein diet. No significant alterations in behavioral and biochemical parameters were observed in the pups born to dams exposed to styrene and receiving a normal protein diet at this dose level. These results suggest that protein deficiency during early life renders the animals more susceptible to styrene.

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.

Sixth mycelial fraction acetone (6-MFA), an interferon inducer modulates acrylamide neurotoxicity

A single i.p. administration of an immunomodulatory agent 6-MFA (a biological response modifier and antiviral agent of fungal origin, 10 mg/100g b.wt.), on 5th day of repeated acrylamide (ACR, 50 mg/kg b.wt.) treatment significantly protected rats against its specific neurotoxic effects. Corpus striatal 3H-spiperone binding elevated (24%) while glutathione-S-transferase (GST) activity decreased (33%) in ACR group but values were markedly restored in 6-MFA alone and co-exposed group. Development of hind limb paralysis was also protected by 6-MFA. Results warrant the possible involvement of immune mechanisms and certain other factors such as lymphokines, hormones and microglia at the target site, which in turn facilitate the repair mechanism suggesting a therapeutic role of 6-MFA in clinical cases of toxic neuropathies in future.

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.

Keratomycosis caused by Dichotomophthoropsis nymphaearum

A case of Dichotomophthoropsis nymphaearum, a dematiaceous hyphomycete, is described from Bangladesh. This species has not previously been reported as a human pathogen. Hyphae were observed in Gram stained corneal scrapings and the species was grown from cultured corneal material. Treatment with topical econazole and subconjunctival injections of miconazole was successful in the short term but long-term outcome could not be determined. The results of sensitivity tests for six antifungal drugs are reported for the isolate.

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.

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.

Protective effect of 6-MFA, an interferon inducer against acrylamide neurotoxicity

Protective effect of 6-MFA, an interferon inducer and antiviral agent of fungal origin, was investigated against the neurotoxic effects induced by acrylamide in rats. Animals of 6-MFA (2.5, 5, 10 mg/100 gm, i.p.) pretreated plus acrylamide (ACR) group exhibited a reduction in development of hind limb paralysis which was 34, 25 and 20 (%) with increasing doses of 6-MFA respectively. Corpus striatal dopamine binding was significantly raised in the ACR treated rats while 6-MFA (10 mg) plus ACR group showed no significant change, in comparison to respective controls. Increased binding in the 6-MFA (2.5, 5 mg) pretreated plus ACR group was also evident. Glutathione-s-transferase (GST) activity was markedly reduced (66%) in ACR alone rats while no change was noted in rats pretreated with either dose of 6-MFA alone. However, a significant reversal was noted in animals of 6-MFA plus ACR group in a dose related manner. Conservation of glutathione levels and involvement of microglia, gamma-interferon and other lymphokines has been suggested for the observed protective effect of 6-MFA against neurotoxicity of ACR.

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.

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.