Experimental Absidia corymbifera infection in rabbits: sequential pathological studies.

Intravenous inoculation of young rabbits with 1.4 x 10(5) spores ml-1 of Absidia corymbifera produced gross and microscopic changes principally in the kidneys. Grossly, there was congestion, haemorrhages and greyish-white necrotic foci giving a mottled appearance to the kidneys. Microscopically, besides congestion and haemorrhages, there was a granulomatous reaction characterized by a central necrotic mass containing mycelium surrounded by a reactive zone of neutrophils, lymphocytes, a few macrophages and giant cells. Fibrous tissue proliferation was also present. Characteristic dichotomously branched non-septate fungal hyphae could be demonstrated in the sections of kidneys up to 14 days of infection. In one rabbit, which had died on the 8th day, small granulomatous lesions with fungal hyphae were noticed in the liver's parenchyma.

Experimental Absidia corymbifera infection in rabbits: clinicopathological studies.

Absidiosis was produced experimentally in rabbits by intravenous inoculation of 1.4 x 10(5) spores of Absidia corymbifera. Infected rabbits exhibited a rise in body temperature, anorexia, dullness, listlessness, diarrhoea, occasional blindness, convulsions and death in some cases. Mortality occurred mainly between 6 to 9 days post infection (DPI) and overall mortality was 50 per cent during the three week observation period. No significant difference was observed in erythrocytic indices viz., Hb, PCV, TEC in control and infected rabbits. However, erythrocyte sedimentation rate was considerably increased in the infected rabbits. A state of leucocytosis was observed in the infected rabbits, which was due to increase in the relative percentage of neutrophils and decrease in lymphocytes. There was a significant increase in blood urea nitrogen concentrations of infected rabbits from 3 to 14 DPI as compared to controls, but serum creatinine values were not significantly altered at any stage of infection. The cause of death was attributed to kidney failure and uraemia in infected rabbits. The rabbit was found to be a suitable model for the study of absidiosis.

Hypertension and myocarditis in rabbits exposed to hexachlorocyclohexane and endosulfan.

Male albino rabbits were exposed to the organochlorinated pesticides hexachlorocyclohexane (HCH) and endosulfan (2.5 and 5.0 mg/kg, ip) twice a week for 12 mo. The mean body weight of the rabbits at 12 mo was lower than that of the controls. There was rise in blood pressure and heart rate. Electrocardiograms (ECG) in both the exposed groups showed increases in PR, QT and RR intervals. Extensive myocardial damage was recorded with marked degeneration of muscle fibers vacuolization and leucocytic infiltration. Adrenals had thickened capsules and hyperplasia of cortical cells. Both pesticides produced significant increases (p less than 0.001) of 11-hydroxycortisone at all time intervals. Hypertension and myocarditis occurred in rabbits exposed to HCH and endosulfan.

Comparison of dot enzyme-linked immunosorbent assay (dot-ELISA) with other serological tests for the detection of Brucella antibodies in bovine sera.

A dot Enzyme-linked Immunosorbent Assay (dot-ELISA), using whole cell Brucella abortus antigen dotted on the nitrocellulose membrane bound to a plastic strip (dipstick) was employed for the detection of Brucella antibodies in bovine sera. The results were compared with that of serum agglutination (SAT), Rose Bengal plate agglutination (RBPT) and Complement Fixation test (CFT). All the four tests gave negative reaction in 127 sera obtained from a brucellosis free herd. Testing of 549 sera from a chronically infected herd revealed 57 positive and 447 negative animals in all the four assays. Of the remaining 45 sera, 34 were positive in dot-ELISA. Six of these cases were independently detected by dot-ELISA while 28 showed positive reactions in combination with other tests. When serum samples from 158 aborted cases were subjected to dot-ELISA, 79 were found positive. Of these dot-ELISA positive cases, 71 gave positive reaction in SAT, 72 in RBPT and 78 in CFT. B. abortus biotype 3 was isolated from 34 of the 98 aborted fetuses examined.

Effect of repeated exposure to lindane and cadmium on lindane metabolism in rats.

The effects of daily administration of cadmium and lindane for 35 days on the metabolism of lindane in rats were investigated. The results indicate that cadmium induces a significant inhibition of lindane metabolism, since the group dosed with lindane plus cadmium had a significantly higher concentration of lindane in plasma and tissues than the group dosed with lindane alone. The inhibition in the metabolic rate of lindane is associated with the cadmium-induced alterations in the disposition of essential trace elements, Zn, Cu and Fe, in the liver.

Counter-immunoelectrophoresis for the detection of Brucella antigen and antibodies in the diagnosis of brucellosis in buffaloes.

Counter-immunoelectrophoresis was employed for the detection of Brucella antigen in stomach contents of aborted buffalo fetuses and antibody in aborted as well as apparently healthy in contact buffaloes. Five of 16 aborted cases were serologically positive for brucellosis but isolation of Brucella abortus was successful in only two cases. By counter-immunoelectrophoresis, Brucella antigen was detected in the fetal stomach contents of four serologically positive cases. Of the 68 serum samples from in contact healthy buffaloes, 10 were positive with counter-immunoelectrophoresis: more than were detected by tube agglutination, Rose Bengal plate agglutination, complement fixation and agar gel precipitation test.

Lindane-induced changes in glucose and glutathione levels in cats.

Cats were given lindane (1 and 2 mg/kg i.v.) and the levels of glucose in blood and glutathione in blood and liver were measured at 30 min, 1, 2, 4 and 8 h. The results showed a sharp decrease in blood glutathione at an early interval with subsequent recovery, whereas there was no change in liver up to 2 h followed by a significant decrease at later intervals with no sign of recovery. The pesticide also showed a hypoglycemic effect at all intervals.

Detection of brucella antigen in bovine fetal stomach contents by agar gel precipitation and counter-immunoelectrophoresis.

Among 21 fetuses from serologically positive dams soluble brucella antigen was detected in the stomach contents in 14 instances by agar gel precipitation test and in 19 by counterimmunoelectrophoresis. Brucella abortus biotype 3 was isolated from the fetal stomach contents in 15 of these cases. None of 20 fetuses from serologically negative dams revealed brucella antigen in the stomach contents in either test.

Distribution, excretion and in-vivo metabolism of 14C-hexachlorobenzene and the influence of iron overload in C57BL/10 mice.

Iron overload did not greatly alter the distribution and total excretion of radioactivity from 14C-hexachlorobenzene (HCB) in male C57Bl/10 mice. An increase was observed in the urinary excretion of metabolites but its significance is unclear.

Fate of hexachlorobenzene in C57BL/10 mice with iron overload.

The distribution of radioactivity in male C57BL/10 mice dosed with [14C]hexachlorobenzene (HCB) was followed over 21 days and found to be high in adipose tissue and adrenals, moderate in thymus whereas liver was relatively poorly labelled. A predose of iron (500 mg/kg), which greatly promotes the porphyrogenic action of HCB in this strain, had only a small effect on the distribution of radioactivity in tissues and excreta. Iron induced excretion of urinary metabolites from HCB by C57BL/10 mice but not by the insensitive DBA/2 strain. However, there was no such difference in faecal metabolites, total metabolism was only slightly increased and there was no correlation between liver porphyrin levels and urinary excretion of metabolites by individual mice. At the end of 4 weeks exposure of iron-treated C57BL/10 mice to HCB urinary metabolites fell while porphyrin excretion continued to rise. Thus the considerable sensitisation of the C57BL/10 strain after iron overload to the induction of porphyria by HCB cannot be ascribed simply to enhancement of total metabolism but must be caused either by the formation of a specific undetected metabolite or induction of some other toxic process.

The acute toxicity of endosulfan to fresh-water organisms.

A static bioassay is performed for measuring the short-term (96 h) toxicity of endosulfan to juvenile catfish Clarias batrachus, insect nymph Enallagma sp. and frog tadpoles of Rana tigrina. Median Tolerance Limit, Slope Function, Confidence Limit, and Presumable Harmless Concentration were computed. The results showed that frog tadpoles are more susceptible to endosulfan than insect nymph and catfish. Morphological changes and behavioural alterations were evaluated as symptoms of endosulfan toxicity.

Effect of endosulfan of bioelectrical activity of brain in rats.

Bioelectrical activity of rat brain was studied after administration of endosulfan (5 mg/kg, ip) for 10 days. The pesticide produced rhythmic bursts of spikes and waves of seizure pattern that started 25-30 minutes after dosing and persisted for 60-minutes. The clonic convulsions were more marked over the head region and were mainly localized in the upper extremities. Histopathologic examination of the liver showed congestion of the central veins and its adjacent sinusoids. Concentration of the compound in brain parallelled the electrical activity.

Toxicological studies of ammonium sulfamate in rat after repeated oral administration.

A 90-day study involving administration of O (group 1), 100 (group 2), 250 (group 3) and 500 mg/kg (group 4) of ammonium sulfamate to rats 6 days a week was carried out. No adverse effect was observed in respect of appearance, behaviour or survival of animals. No significant difference in the body weights of rats was observed except in case of adult rats (group 4) where the body weight was significantly less than the controls after the end of 60 days. In all the groups food intake gradually reduced whereas water intake increased as the experiment proceeded. No significant change in relative organ weights were noticed in all groups of rats. Haematological examination conducted at 30, 60 and 90 days revealed non-significant increase in the neutrophils in the adults and male weanling rats (group 4) after 90 days. In the histological examination, organs in all the groups of animals appeared normal except that the liver of 1 rat in adults (group 4) showed slight fatty degenerative changes after 90 days.

Changes in brain acetylcholine of rats after dermal application of fenitrothion (Sumithion).

Fenitrothion (Sumithion), and organophosphorous insectide, was applied dermally to rats. Cholinesterase activity was measured in blood and brain. The concentration of the pesticide in blood plasma and acetylcholine in brain were estimated at different intervals. The maximum concentration of Fenitrothion in the plasma was found at 4 hrs while significantly elevated levels of acetylcholine were present in the brain till 24 hrs. The results suggest that the compound was readily absorbed by dermal route to produce inhibition of cholinesterase and a consequent persistent increase in brain acetylcholine.