Anemia in experimental visceral leishmaniasis in hamsters.

Experimental infection of hamsters with Leishmania donovani caused visceral leishmaniasis in which hematological changes occurred. The infected hamsters were anemic and reticulocyte counts were high. No significant change in the serum erythropoietin level was noted. Red cell membrane Na(+)-K(+)-ATPase and acetylcholinesterase activities increased. Osmotic fragility of the erythrocytes from infected animals increased. The level of 2,3-diphosphoglycerate of the red cells increased with the degree of anemia.     

Role of Ca2+ ion on Leishmania-macrophage attachment

Summary Leishmania donovani, the etiological agent for the disease visceral leishmaniasis, attach themselves to the macrophages for initiation of the disease. The attachment process has been found to be regulated by Ca²⁺ ions. Verapamil, a Ca²⁺-channel blocker inhibits Leishmania-macrophage attachment. The inhibitory effect is increased with time. Nifedipine, another Ca²⁺-channel blocker exhibits the same effect. The attachment process is stimulated by Ca²⁺-ionophore alone. The inhibitory effects of the calcium channel blockers are reversed by the ionophore.     

Leishmania donovani: a chemically defined medium suitable for cultivation and cloning of promastigotes and transformation of amastigotes to to promastigotes

A chemically defined medium using commercially available alpha-MEM supplemented with hemin, HEPES, L-glutamine, D-glucose, folic acid, D-biotin and adenine supports the luxuriant growth and propagation of Leishmania donovani promastigotes. A peak parasite population of about 7.0 x 10(7)/ml at stationary phase and a population doubling time of 11.4 h for high-subpassage promastigotes were obtained. The medium was suitable for transformation of isolated amastigotes from infected hamster spleen. Promastigotes could be detected by culturing kala-azar patients' bone-marrow aspirate or spleen puncture material in this medium. Four out of six freshly transformed isolates gradually adapted and grew well in this medium. Macroscopic colonies appeared on agar plates prepared with the medium within 16-20 days after inoculation. The cloning efficiency was increased about five-fold by glycerol supplementation.     

Identification of Novel Allelic Variants of Integrin Beta 2 (ITGB2) Gene and Screening for Bubaline Leukocyte Adhesion Deficiency Syndrome in Indian Water Buffaloes (Bubalus bubalis)

A fragment of 570 bp corresponding to exon 5 and 6 of integrin beta 2 (ITGB2) gene was amplified for screening D128G mutation in one hundred and fifty two buffaloes (Bubalus bubalis) which causes bovine leukocyte adhesion deficiency syndrome (BLAD) in cattle, as well as to ascertain polymorphism. TaqI PCR-RFLP revealed no such mutation thus indicating the absence of bubaline leukocyte adhesion deficiency (BuLAD) allele in animals under study. However, the polymorphism studies using MspI restriction enzyme revealed two genotypic patterns viz. AA pattern (bands of 293, 141, 105, and 31 bp) and BB pattern (bands of 293, 105, 77, 64, and 31 bp). The sequences of A and B alleles were submitted to the GenBank (EU853307 and AY821799).     

Modulation of serum cortisol by substance P in albino rats: evidence of a direct effect on adrenal gland

Effect of prolonged administration of substance P on the plasma cortisol level in the albino rats has been investigated. An inhibitory impact on intact individuals and a stimulatory effect in pharmacologically annulled rats has been observed. It is concluded that in normal conditions substance P presumably acts as a preventive agent for any excess secretion of cortisol while during stress or disturbed HPA or RAS conditions, it stimulates the secretion of cortisol. An intraglandular modulatory role of substance P has been suggested.     

Semiparametric analysis of two-level bivariate binary data

In medical studies, paired binary responses are often observed for each study subject over timepoints or clusters. A primary interest is to investigate how the bivariate association and marginal univariate risks are affected by repeated measurements on each subject. To achieve this we propose a very general class of semiparametric bivariate binary models. The subject-specific effects involved in the bivariate log odds ratio and the univariate logit components are assumed to follow a nonparametric Dirichlet process (DP). We propose a hybrid method to draw model-based inferences. In the framework of the proposed hybrid method, estimation of parameters is done by implementing the Monte Carlo expectation-maximization algorithm. The proposed methodology is illustrated through a study on the effectiveness of tibolone for reducing menopausal problems experienced by Indian women. A simulation study is also conducted to evaluate the efficiency of the new methodology.