Purification and characterization of tannin acyl hydrolase from Aspergillus niger MTCC 2425

The present investigation was carried out for increasing the yield of tannase of Aspergillus niger and the physico-chemical characterization of this enzyme. the extraction of enzyme protein. However, extraction of fungal pigments and proteins was observed to have high pH dependence, and maximum enzyme extraction was obtained at pH 5.5. The two-step purification protocol gave 51-fold purified enzyme with a yield of 20%. The total tannase activity was made up of nearly equal activity of esterase and depsidase. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of purified tannase protein indicated it to be made up of two polypeptides of molecular weight 102 and 83 kDa. Based on the Michaelis-Menten constant (Km) of tannase for three substrates tested, tannic acid was the best substrate with Km of 2.8 x 10(-4) M, followed by methyl gallate and propyl gallate. The inhibition was maximum for CaCl2 (58%) whereas EDTA had no modulatory effect on tannase activity. The inhibitor binding constant (KI) of CaCl2 was 5.9 x 10(-4) M Homogenization and detergent pretreatments did not have any remarkable effect on and the inhibition was of noncompetitive type.     

Chromatin interactions in differentiating keratinocytes reveal novel atopic dermatitis– and psoriasis-associated genes

1. Download : Download high-res image (202KB)
2. Download : Download full-size image

     

Cadmium and zinc induced nuclear changes in the liver and kidney of rats

When administered to animals cadmium is known to accumulate in the liver and kidney causing indentifiable toxicity. However, its binding with cell sap and nucleus and effects on their constituents are poorly known. Since nuclear changes reflect some of the metabolic disturbances and are of value in diagnosis, an attempt has been made to analyse their morphology and chemistry in the liver and kidney of rat after individual and combined treatment with Cd and Zn. Present observations clearly show that cadmium inhibits DNA synthesis by blocking the formation of the enzyme thymidine triphosphate which is prerequisite for DNA synthesis. Zinc exerted a stimulatory effect on DNA and RNA both by increasing the activity of thymidine kinase. Their combined effects were found to be less injurious to the cell. Though these changes could be a secondary or generalized response of nuclei to altered physiological conditions, specific reasons for these changes have been discussed.     

Efficiency of cross presentation of vaccinia virus-derived antigens by human dendritic cells.

Dendritic cells (DC) utilize at least two pathways to process viral antigens onto MHC class I molecules. The conventional endogenous route is used to acquire antigens from both infectious and non-replicating virions. Exogenous pathways are used by DC to acquire and "cross-present" antigens derived from virus-infected donor cells that by themselves lack the ability to activate T cells directly. We analyzed the role of this pathway for antigens derived from vaccinia, a virus which inhibits DC maturation and causes extensive apoptosis of infected cells, yet is highly immunogenic. Using recombinant vaccinia virus encoding the influenza matrix protein as model vector, DC were shown to cross-present vaccinia-derived antigens from both apoptotic and necrotic infected cells to antigen-specific CD8(+) T cells. Efficient cross presentation required uptake of dead cells by immature DC and exposure to maturation stimuli, especially CD40 ligand. The responding CD8(+) T cells secreted IL-2 and IFN-gamma, proliferated and developed into cytotoxic effectors. Quantification of the cross presentation of vaccinia-derived antigens showed this pathway to be highly efficient, corresponding to a peptide pulse of 10-100 nM. While monocytes also phagocytosed apoptotic and necrotic cells, they were far less efficient at cross-presenting vaccinia-derived antigens to CD8(+) T cells. The ability of DC to cross-present vaccinia-derived antigens from infected apoptotic cells or necrotic cell lysates, bypasses the deleterious effects of direct infection of DC and provides one explanation for this pathogen's immunogenicity.     

IL-4–BATF signaling directly modulates IL-9 producing mucosal mast cell (MMC9) function in experimental food allergy

1. Download : Download high-res image (233KB)
2. Download : Download full-size image

     

Needle necropsy in AIDS

The value of autopsy in understanding the natural course of any disease is beyond any argument. The reluctance of pathologists to perform autopsy in HIV infected cadavers is justified due to the risks involved to the prosector and the morgue attendants. A relative low risk needle necropsy protocol is proposed using fine needle aspiration cytology, tru-cut biopsies and microbiological examination. Diagnosis could be offered in all the forty-four needle necropsies performed. Disseminated tuberculosis in 18/44 (40.9%) cases, disseminated cryptococcosis in 12/44 (27.2%) cases, poly-microbial infections in 27.2% cases and non-Hodgkin's lymphoma in 9% cases were detected in the study. Infectious agents like Histoplasma capsulatum, Isospora belli, tachyzoites of Toxoplasma gondii, Candida sp and Cryptococcus sp could be demonstrated in the samples obtained in the study. Lack of material for study of gross pathology, inaccessibility of deep-seated lesions and risk of needle stick injury to the prosector though low are the limitations of this procedure.     

Closed Transverse Pinning for Reduction and Fixation of Metatarsal Neck Fractures: Surgical Technique

Most metatarsal neck fractures can be successfully treated non-operatively in a cast boot. Displaced metatarsal neck fractures tend to be less stable and have a propensity for the distal fragment to angulate, secondary to the strong flexor tendons, which often forces the distal fracture fragment in a plantar direction and leads to relative metatarsal shortening. Most literature is focussed on antegrade fixation of metatarsal neck fractures using pre-bent K wires or thin elastic nails. Apart from the technical challenges, this technique is limited when bones are osteoporotic as the pre-bent distal end of the K-wire may penetrate the plantar cortex of the proximal metatarsal and prevent the wire from entering the medullary canal of the metatarsal and advancing to the fracture site. Furthermore, when the medullary canal is narrow especially in Asian patients, it may be difficult to pass a bent K-wire through the isthmus of the metatarsal shaft. We describe an innovative technique of closed transverse wiring of the metatarsal head necks that has a distinct advantage in Asian population with osteoporotic bones. With percutaneous manipulation using digital pressure, closed reduction of fracture fragments of the most displaced fracture is done under fluoroscopic guidance to achieve a satisfactory alignment followed by closed transverse wiring of the metatarsal heads. With this procedure, adjacent fractures remain stable within an acceptable range because of intermetatarsal ligaments connected to the adjacent intact head. Our technique has a relatively short operating time and allows for early motion of the metatarso-phalangeal joint. This is especially useful for those with osteoporosis, narrow canal, soft tissue compromise, intra-operative failure of ante-grade pinning and in scenarios of limited surgical equipment/expertise.     

Access to health care. A conceptual framework and its relevance to health care planning

Despite some serious past efforts to clarify its multiple dimensions and meanings, access to health care has remained a rather elusive concept, hampering the work of health care policymakers and professionals as they endeavor to effect meaningful health care reform. This article provides perhaps the most detailed clarification of the access concept, especially the crucial linkages among the various access dimensions, and presents a comprehensive conceptual framework for evaluation and planning activities as they relate to people's access to health care services. The proposed conceptual model recognizes access as the outcome of a process involving the interplay between the characteristics of the health care service system and of potential users in a specified area, and moderated by health care related public policy and planning efforts. An elaborate typology of access, incorporating four pairs of access dimensions, is also derived. This atomization of the concept allows us to focus on specific aspects of the access to health care problem, and to develop precise outcome indicators of health system performance for evaluative purposes. Further, it enables the access concept and its pertinent dimensions to be put into proper perspective when assessing the health care access situation in a specific national or regional context. The relevance of the proposed access model and the typology to health care planning in general, and to spatial planning of health care service systems in particular, is also discussed.     

Randomised controlled trial on modified squatting position of delivery

In 1992 at Vivekanand Hospital in Latur, Maharashtra State, India, researchers randomly allocated 326 pregnant women, 15-45 years old, at full term, to either the modified squatting position group (study group) or the normal lithotomy delivery position group (control group) to determine whether the modified squatting position using a birth cushion has any advantages over the normal delivery position. The U-shaped cushion is inexpensive, constructed with coir and foam, and has a washable cover. Its two handles provide the woman support as she pushes and delivers the newborn. There were 145 women in the study group and 181 in the control group. Women in the squatting position did not receive any episiotomies. They spent less time pushing (i.e., in second stage of labor) than those in the control group (median, 21.2 vs. 39.32 min; p 0.01), especially among gravidae 2 and above. The time required to perform vaginal operative delivery was much shorter for the squatting position than for the normal delivery position (11.6 vs. 28.86 min; p 0.01). Fetal stress was more common among newborns delivered by the normal delivery position than among those delivered by the squatting position (7.73% vs. 3.44%; p 0.05). Women in the squatting group were more likely to have an intact perineum after delivery than those in the control group. None of the women in the control group had postpartum vulval edema, while five in the study group did. The edema was mild, however, and resolved itself within 24 hours of delivery. Most women in the squatting position group were satisfied with this position. These findings suggest that the squatting position using a birth cushion has more benefits than the normal delivery position. It allows better coordination and more effective pushing. Traditional birth attendants and female health workers at subcenter and primary health center levels can be trained to use the birth cushion during labor.