A multipronged approach for the detection of leptospirosis in captive sloth bears (Melursus ursinus) in Agra and Bannerghatta sloth bear rescue centers in India

Leptospirosis is an exacerbating factor responsible for the drastic decline of sloth bear population in India. In this study, a multipronged approach based on antigen detection using Polymerase Chain Reaction (PCR) employing G1/G2 and LigBF/LigBR primers, antibody detection using Microscopic Agglutination Test (MAT) and recombinant LigBCon1-5 antigen based Latex Agglutination Test (rLigBCon1-5 LAT), serum biochemistry using hepatic (serum glutamate oxalo acetic transaminase (SGOT) and serum glutamate pyruvic transaminase (SGPT) and renal biomarkers (blood urea nitrogen (BUN) and Creatinine) and gross/histopathological evidence in liver and kidneys were employed to investigate leptospirosis in captive sloth bears. A total of 133 serum samples collected from Agra (n=113) and Bannerghatta (n=20) sloth bear rescue centers were screened using MAT and rLigBCon1-5 LAT. A total of 87 and 78 sera tested positive by MAT and LAT respectively. Pyrogenes was the leading serovar obtained using MAT followed by Icterohaemorrhagiae, Javanica, Grippotyphosa, Canicola and Tarassovi. The relative sensitivity, specificity and accuracy of rLigBCon1-5 LAT in comparison to MAT were 89.66%, 100% and 93.23% respectively. PCR performed on hepatic and renal tissues showed amplicon of 285 and 219 base pairs for G1/G2 and LigBF/LigBR primers respectively. Gross evidence (icteric liver, severely engorged hepatic sinusoids, congested kidneys with necrotic white spots on sub capsular surface), histopathology (severe hepatic degeneration and tubulointerstitial nephritis) and elevated hepatic/renal biomarkers were suggestive of leptospirosis. This study suggests that rLigBCon1-5 LAT can be employed as a pen-side test for detecting leptospirosis in sloth bears.     

Leaching of a sorbed solute: A model for peak concentration displacement

Summary An investigation of the downward transport of a solute following a series of alternating irrigation/rainfall and evapotranspiration events is carried out. The principle of conservation of mass, and the concepts of partition chromatography are used in constructing a simple model which enables the peak solute concentration depth to be calculated at any particular time given the rainfall and evapotranspiration history. Prediction of the theory is compared with published data on solute transport.     

The fatty acid binding protein 6 gene (Fabp6) is expressed in murine granulosa cells and is involved in ovulatory response to superstimulation

The fatty acid binding protein 6 (Fabp6) is commonly regarded as a bile acid binding protein found in the distal portion of the small intestine and has been shown to be important in maintaining bile acid homeostasis. Previous studies have also reported the presence of Fabp6 in human, rat and fish ovaries, but the significance of Fabp6 in this organ is largely unknown. Therefore, we surveyed murine ovaries for Fabp6 gene expression and evaluated its role in ovarian function using mice with whole body Fabp6 deficiency. Here we show that the Fabp6 gene is expressed in granulosa and luteal cells of the mouse ovary. Treatment with gonadotropins stimulated Fabp6 gene expression in large antral follicles. The ovulation rate in response to superovulatory treatment in Fabp6-deficient mice was markedly decreased compared to wildtype (C57BL/6) mice. The results of this study suggest that expression of Fabp6 gene in granulosa cells serves an important and previously unrecognized function in fertility.     

Overexpression of parathion hydrolase in Escherichia coli stimulates the synthesis of outer membrane porin OmpF

Parathion hydrolase (PH), also known as organophosphorus acid anhydrase, hydrolyses the triester linkage found in organophosphates including organophosphate pesticides and the nerve gas sarin. The enzyme is reported to be membrane-associated and the immature protein has a signal sequence of 29 amino acids. In experiments designed to examine the post-translational processing of the enzyme and to assess the distribution of the precursor and mature forms of the protein, we induced expression of the Flavobacterium balustinum PH structural gene, opd, in Escherichia coli strain BL21. Western blotting revealed that the induced PH was predominantly membrane-associated in E. coli but a protein band equivalent in size to mature PH was also found to be induced specifically in periplasmic fractions. This periplasmic protein was not PH, as it did not cross-react in Western blots, and N-terminal sequencing of the induced protein showed it to have 100% homology to the outer membrane protein OmpF.     

Long-term solute dynamics and hydrology in irrigated slowly permeable soils

Summary A simple model is given, based on mass conservation of a non-transformed non-absorbed solute or ion (such as the chloride ion), which allows long term trends in the concentration of this solute to be predicted. The method involves solution of an implicit equation for the long term through-drainage flux below the maximum depth of sampling. A knowledge of the initial chloride ion concentration in the soil depth of interest, and its value after a known application via irrigation water provides sufficient information for the model to be applied. The model is applied to data from an irrigated slowly permeable swelling clay soil. A drainage flux of 8 cm yr^–1 beneath paddy rice was inferred, and some twenty-five years after commencement of irrigation an equilibrium soil salinity of 22 meq/l at saturation was predicted.