Tuesday, May 10, 2011

THE AUTODESTRUCTION OF PEPSIN IN RELATION TO ITS IONIZATION






Arthur M. Goulding, Henry Borsook, and Hardolph Wasteneys
From the Department of Biochemistry, University of Toronto, Toronto, Canada.
Accepted September 30, 1926.

1. Evidence is presented that pepsin is a univalent acid with a value for pK of 6.85 (or a base, with pK 7.39). 2. The autodestruction of the pepsin is shown to be dependent in part upon an instantaneous irreversible change occurring in the ionized form of the enzyme (if it be an acid) or in the unionized form (if it be a base). 3. A further progressive autodestruction of pepsin at any given hydrogen ion concentration and temperature is defined by the mass law equation for a monomolecular reaction 4. The velocity of autodestruction of pepsin is directly proportional to the hydroxyl ion concentration. It is much less in the range of hydroxyl ion concentration from pOH 9.89-7.7, than in the range greater than pOH 7.7. In both of these ranges variations in pK with pOH may be represented by straight lines.

Monday, May 09, 2011

DocMarCell’s laboratory

DocMarCell’s laboratory, containing his archive of texts and images, reveals a distorted vision on ordinary, harmless objects. It is a space defined by all the fears of the contemporary man, obsessed with hygiene and aseptic environment, living in the presence of genetic experiments and fatal germs.

DocMarCell is first of all a witness; but at the same time, through analysis and his fake constructs related to the collective "virused" subconsciusness, he becomes a valve for letting off steam.




The Journal Of Immunology by DocMarCell





Friday, April 15, 2011

Adaptive Immune Regulation in the Gut: T Cell–Dependent and T Cell–Independent IgA Synthesis



In mammals, the gastrointestinal tract harbors an extraordinarily dense and complex community of microorganisms. The gut microbiota provide strong selective pressure to the host to evolve adaptive immune responses required for the maintenance of local and systemic homeostasis. The continuous antigenic presence in the gut imposes a dynamic remodeling of gut-associated lymphoid tissues (GALT) and the selection of multiple layered strategies for immunoglobulin (Ig) A production. The composite and dynamic gut environment also necessitates heterogeneous, versatile, and convertible T cells, capable of inhibiting (Foxp3+ T cells) or helping (TFH cells) local immune responses. In this review, we describe recent advances in our understanding of dynamic pathways that lead to IgA synthesis, in gut follicular structures and in extrafollicular sites, by T cell–dependent and T cell–independent mechanisms. We discuss the finely tuned regulatory mechanisms for IgA production and emphasize the role of mucosal IgA in the selection and maintenance of the appropriate microbial composition that is necessary for immune homeostasis.