Differential release of mast cell mediators and the pathogenesis of inflammation

Summary:  Mast cells are well known for their involvement in allergic and anaphylactic reactions, during which immunoglobulin E (IgE) receptor (FcɛRI) aggregation leads to exocytosis of the content of secretory granules (1000 nm), commonly known as degranulation, and secretion of multiple mediators. Recent findings implicate mast cells also in inflammatory diseases, such as multiple sclerosis, where mast cells appear to be intact by light microscopy. Mast cells can be activated by bacterial or viral antigens, cytokines, growth factors, and hormones, leading to differential release of distinct mediators without degranulation. This process appears to involve de novo synthesis of mediators, such as interleukin-6 and vascular endothelial growth factor, with release through secretory vesicles (50 nm), similar to those in synaptic transmission. Moreover, the signal transduction steps necessary for this process appear to be largely distinct from those known in FcɛRI-dependent degranulation. How these differential mast cell responses are controlled is still unresolved. No clinically available pharmacological agents can inhibit either degranulation or mast cell mediator release. Understanding this process could help develop mast cell inhibitors of selective mediator release with novel therapeutic applications.     

Statistical Optimization of Bioprocess Parameters for Improved Production of L-Asparaginase from Lactobacillus plantarum

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - L-asparaginase (ASNase), a tetrameric enzyme, holds comprehensive applications in food industries as a...     

Nonobese diabetic mice,hypoglycaemia and liver necrosis: a case report

This study investigates a case in a type I diabetic animal model, using nonobese diabetic mice, affected with hypoglycaemia and liver necrosis with other symptomatic complications. This particular animal was markedly different from other animals in the colony, and the investigations we carried out diagnosed various conditions such as growth retardation, frank diabetes, hypoinsulinaemia, hypoglycaemia and multiple foci liver necrosis with nucleomegaly. From the differential diagnosis, we hypothesize that this abnormality might be due to carbohydrate metabolic deficiency giving rise to diabetes and liver necrosis. We postulate that in these conditions, the liver controls the pancreas and that the liver should be the key target organ to control diabetes coupled with hypoglycaemia. Further investigations into the relationship between the carbohydrate metabolism, liver failure and overt diabetes in nonobese diabetic (NOD) animal models might have relevance to human disease.     

Making the decision to donate eyes: Perspectives from the families of the deceased in Madurai,India

Purpose:To identify factors affecting family members'' decision whether to donate eye organs.Methods:A community-based case-control study based on in-home interviews with families of deceased individuals who had or had not donated eye organs, in Madurai district, Tamil Nadu, India. Data collected were knowledge and awareness of eye donations, whether the deceased individual had expressed or pledged willingness to donate, and family members'' attitudes and willingness to donate their own eye organs.Results:Seventy-six families of donors and 256 families of non-donors completed the survey. Multivariable analysis showed that the following variables were significantly associated with a donation: age, whether the deceased had registered for eye donation, pre-expressed willingness of deceased to donate, whether family members personally know beneficiaries of eye donations, and higher score on a scale evaluating knowledge and awareness about eye donation. The majority of donors'' families (71%) had been encouraged by someone to donate. Among non-donor families, a substantially larger fraction (52.8%) indicated they would have donated had someone reminded or encouraged them to do so, in comparison with those who indicated lack of awareness or knowledge (14.5%).Conclusion:Community programs are likely to be effective if they encourage individuals to pledge their eyes or express their willingness to donate their eyes to family members in advance of death; they increase public awareness of the value of eye donation. A friend, family member, neighbor or counselor approaching bereaved families and having a dialogue about eye donation would substantially increase the probability of a decision to donate.