Hematological changes produced by lindane (gamma-HCH) in six species of birds

Hematological changes were studied after oral administration of lindane (gamma-hexachlorocyclohexane) at 5 mg/kg body weight twice in 1 week in 6 species of agriculturally important birds: house sparrow, baya weaver bird, common myna, rose-ringed parakeet, blue rock pigeon and domestic duck. Lindane induced anemia in the birds as judged by reduced RBC count, hematocrit and hemoglobin content with corresponding changes in MCV, MCH and MCHC. Bleeding and clotting time were markedly prolonged. Splenic cell counts were decreased with marginal increase of splenic weight in most of the lindane fed birds. Total leucocyte counts were increased while the differential counts of WBC show marked heterophilia and eosinophilia with a decrease in monocyte, lymphocyte and basophil numbers. Domestic duck appears to be somewhat resistant compared to the wild birds studied. Besides anemia the results suggest both immunosuppression and stress effects and indicate that early hematological changes induced by lindane may serve as an initial warning for pesticide toxicity.

Nucleic acids in the spermatozoa of pure and strain crosses of White Leghorn cockerels

Nucleic acids (DNA and RNA) were estimated in the spermatozoa of three pure strains (M, N and P) and three strain crosses (N X P, M X N and P X M) of White Leghorn cockerels. The average DNA content was 2.31 +/- 0.06 X 10(-9)mg/sperm. Most was found in the P X M strain cross and least in the P strain. The DNA content of the P strain was significantly lower than that in the other strains and it also had the lowest fertility and hatchability of all the strains. The average RNA content in poultry spermatozoa was 0.0522 +/- 0.0038 X 10(-9)mg/sperm. Again, most RNA was found in the P X M strain cross and least in the P strain. The P X M strain cross had a significantly higher RNA content than the rest of the strains. Thus, the P X M strain contained the most DNA and RNA whereas the P strain had least.

Density of Culex vishnui and appearance of JE antibody in sentinel chicks and wild birds in relation to Japanese encephalitis cases

In the District of Burdwan, a rural area of West Bengal State, India, Japanese encephalitis (JE) virus is endemic. In one village a longitudinal survey was conducted in order to find out whether associations could be established between the density of the vector mosquito Culex vishnui in two types of resting places, the incidence of infections in sentinel chicks exposed at monthly intervals, the prevalence of antibodies in wild birds and the occurrence of clinical infections in the human population. The experiment lasted from August 1981 till August 1982. Meteorologically a summer season (March-June), a rainy season (July-October) and a winter season (November-February) are distinguished. In the sentinel chicks infections were observed in all three seasons; in wild birds antibodies were prevalent throughout the year; these observations suggest perennial transmission of the virus in its maintenance cycle. Human infections were observed periodically with, in August 1982, a pronounced peak; this may point to fluctuations in the level of circulation of the virus in its maintenance cycle and spillover to the human population at times of peak circulation. The peaks may be related to the influx of young non-immune birds and newborn mammals into the animal population in summer. Further studies, including virus isolation attempts from mosquitoes and nestling birds, are required to prove this hypothesis.

Estradiol modulation of pineal gland activity in the wild bandicoot rat, Bandicota bengalensis

In the present study, the effect of estradiol dipropionate on the cytology and mitotic activity of the pineal gland was evaluated in adult ovariectomized and juvenile bandicoot rats, Bandicota bengalensis. Estradiol treatment for 5 days inhibited the ovariectomy-induced hypertrophy of the pineal gland, and increased the nuclear diameters of pinealocytes in juvenile males while having no effect on the pineal cytology of juvenile females. Estradiol injection induced mitosis in the pinealocytes of adult ovariectomized and juvenile bandicoot rats. Thus, estradiol exhibited a dual action (stimulatory and inhibitory) on the pineal gland of this wild rat.

The reduction of root colonization by mycorrhizal fungi by mycophagous amoebae

Two mycophagous amoebae, Saccamoeba sp. and Gephyramoeba sp., reduced the colonization of pine roots in soil by the ectomycorrhizal fungus, Rhizopogon luteolus, when added at the same time as the fungus or 2 weeks later. Another mycophagous amoeba, an unidentified leptomyxid, was unable to do so. When seedlings were grown in sterilized soil amended with different population levels of Saccamoeba, 42 and 85 amoebae g soil−1 had no effect but large reductions in root colonization by R. luteolus occurred when 430 and 860 amoebae g soil−1 were added. After 4 weeks, however, the protozoa population increased to a similarly high level in all treatments irrespective of the numbers added initially. Our results indicate that protozoa can have a large effect on the establishment of inoculated symbiotic fungi and could markedly affect the microbial composition of the rhizosphere.

Mitogenic action of prolactin on the pancreatic islet cells in the chick

A histological investigation was made to elucidate whether mammalian (ovine) prolactin can induce mitotic activity in pancreatic islet cell (in splenic lobe) of chicks. Prolactin treatment in different dosages (total dosage: 15, 50 and 100 IU per bird in 10 days) increased the mitotic frequency and also caused hypertrophy in the AF-positive cells of the B-islets in the splenic lobe. The increase in mitotic frequency was uniform for all doses applied. It is suggested that prolactin has a mitogenic action on the pancreatic islet cells of male chicks and that action is possibly not dose-dependent.

Cytophysiological responses of the pineal gland to intermale aggression in a wild rat

Intermale aggression by pairing bandicoot rats (Bandicota bengalensis) in their home cage, continuously for three hours, stimulated the pineal gland activity, cytologically measured by decreasing cell population density and increasing nuclear size of the pinealocytes, in the socially subordinate animals. The pineal gland of the dominant animal was not perceptibly affected by aggression. It is suggested that during aggression, the subordinate rats perhaps suffered from psychosocial stress that might have caused hyperactivity of their pineal gland.

Cytophysiological response of the pineal gland to long-term administration of norethisterone (a progestogen-only contraceptive) in rats

Chronic administration of norethisterone for 75 days caused a marked inhibition of the pineal gland activity of cycling albino rats. In addition to a decrease in the nuclear diameter, possibly the cell size also decreased. The progestin, however, failed to induce mitosis in this gland. It is suggested that prolonged administration of norethisterone exerts untoward effects on the pineal gland function in adult female albino rats.