Developmental and neurobehavioural toxicity study of arsenic on rats following gestational exposure.

To characterize developmental and behavioral alterations induced by arsenic exposure, Albino rats were exposed to arsenic (0, 1.5, 3.0 and 4.5 mg/kg/day/po) from gestation day 8 to till parturition and the offspring were observed over the first 3 postnatal weeks, until they were weaned on post-natal day (PND) 21. Once the pups were delivered (PND0), the treatment was discontinued. All pups were assessed for physical development, reflex development, strength and motor coordination from standard neurobehavioural developmental test batteries beginning on PND1. Gestational administration of arsenic at tested dose levels, showed no significant changes in the day of appearance of eye opening, startle reflex, negative geotaxis and spontaneous alteration performance in comparison to the control group. The number of live fetuses, mean fetal body weight and percentages of resorptions or malformations per litter were not affected by arsenic exposure. No treatment-related malformations or developmental variations were noted at any exposure level, suggesting that arsenic exposure at this dose level did not adversely affect behavioural endpoints of developmental toxicity.

Following basal stem rot in young oil palm plantings.

The PCR primer GanET has previously been shown to be suitable for the specific amplification of DNA from Ganoderma boninense. A DNA extraction and PCR method has been developed that allows for the amplification of the G. boninense DNA from environmental samples of oil palm tissue. The GanET primer reaction was used in conjunction with a palm-sampling programme to investigate the possible infection of young palms through cut frond base surfaces. Ganoderma DNA was detected in frond base material at a greater frequency than would be expected by comparison with current infection levels. Comparisons are made between the height of the frond base infected, the number of frond bases infected, and subsequent development of basal stem rot. The preliminary results suggest that the development of basal stem rot may be more likely to occur when young lower frond bases are infected.

Differential diagnosis of byssinosis by blood histamine and pulmonary function test: a review and an appraisal.

A study was conducted on byssinotic (N = 8) and nonbyssinotic (N = 16) mill workers exposed to cotton dust and on controls (N = 15) from a cotton dust-free zone. They were examined for chest tightness and breathlessness during successive days from Mondays to Fridays. In addition to monitoring the workers only on Mondays after shift work, their blood histamine levels and pulmonary function tests such as FEV1, PEFR, and FEF25-75% (PEFR represents airflow of larger airways, FEF25-75% reflects airflow in smaller airways, and FEV1 represents airflow in both central and peripheral airways) were screened, but Monday data were only counted to appraise a contrast between these two parameters. The results showed that the histamine levels were significantly higher in the cotton dust-exposed workers in association with significantly decreased FEV1, PEFR, and FEF25-75%, indicating bronchoconstriction of the central, larger, and peripheral airways. Histamine can cause a severe constriction of the central as well as peripheral airways in cotton dust-exposed workers, enabling a paradoxical effect for a differential diagnosis of byssinosis.

Effect of lead on anorexia and body weight in albino rats.

Rats exposed to lead (lead acetate) in doses of 0.2 and 0.5 mg/ml in drinking water for a period of 90 days showed mild to moderate changes in food consumption compared to control group. Drug interactions in lead exposed rats with metoclopramide, atropine sulphate, propranolol, cyproheptadine and mepyramine maleate when administered intraperitoneally caused -30 to +30 percentage variation in food intake indicating the influence of adrenergic, serotonergic and cholinergic neurotransmitters with no change in mean body weight of lead treated rats.

Behavioural change in rats due to chronic oral and systemic formaldehyde.

Impact of chronic formaldehyde exposure in respect of route on behaviour was studied. Preconditioned (environmental) male albino rats (340-400 g) in 3 groups (n = 5) under 60 days oral and systemic exposure to 10 mg/kg/day HCHO were examined for their behavioural performance (i.e. short term memory) in Cook's apparatus. Twenty percent rats settled in grade III (unconditioned avoidance response) in the i.p. (i.e. systemic group) whereas in oral fed (HCHO route in drinking water) rats, 60% settled in grade II (conditioned avoidance response) at the end of sixty days.

In vitro study of rat uterus after chronic formaldehyde exposure.

To measure cholinergic, adrenergic and tryptaminergic receptor activity of formaldehyde (HCHO) in rat uterus, albino rats were treated with 5 and 10 mg/kg, ip HCHO for 30 days. Acetylcholine (ACh) in doses 1.33, 2 and 3 micrograms/ml produced mild to moderate contraction of isolated rat uterus in control group. HCHO had no effect on isolated rat uterus per se, however it reduced ACh and carbachol induced contraction and presence of adrenaline influences in respect of ACh and carbachol activity. Adrenaline per se had no effect in control preparations, but reduced carbachol induced contraction. Propranolol had no effect on rat uterus; but its presence in the bathing medium increased activity of adrenaline. 5-Hydroxytryptamine (5-HT) had no effect of its own on isolated rat uterus but its presence in the bathing medium enhanced contractions of carbachol and oxytocin.

Pharmacology of Acorus calamus L.

Water soluble dried powder of alcoholic extract of roots and rhizomes of A. calamus L. was used. The in vivo experiments involved strychnine convulsant activity in frogs, spontaneous motor activity and amphetamine hyperactivity in mice, pentobarbitone sleeping-time in rats and local anaesthetic activity in guinea pigs and rabbits. Frog skeletal muscle and heart preparations and rat phrenic nerve diaphragm constituted the in vitro experiments. Plant extracts at 10, 20 mg/kg ip did not afford protection to strychnine (1,5,2.5 mg/kg) induced convulsions and same effect was found on acetylcholine induced contractions of rectus muscle except that it inhibited caffeine citrate contractions in frog. At 1, 10 and 100 micrograms/ml doses, it caused negative iono- and chronotropic effects in frogs. Dosages of 10, 25, 50 mg/kg ip of herbal extract antagonize spontaneous motor activity and also amphetamine induced hyperactivity in mice. It was less potent than chloropromazine, though exerts sedative and tranquilizing action. Local anaesthetic activity was found to be absent at 0.5 and 1% dose levels.

Blood histamine levels in cotton-dust exposed workers in a textile mill of Ahmedabad.

Blood histamine levels were measured by the bioassay of histamine (on an isolated strip of guinea pig ileum) in workers exposed to cotton dust in a textile mill in Ahmedabad. Byssinotic subjects showed very high levels of blood histamine as compared to nonbyssinotic and control subjects. The blood histamine levels were not well correlated to the dust concentrations or duration of exposure but rather to the day of the week (ie, first, second, third, etc., after weekend break) on which the samples were collected. The blood histamine levels were high on the first day of the work week, when byssinotics complained most of their symptoms.