Thermodynamic study of guanylspecific ribonuclease C2

Guanylspecific RNAse C2 has been studied thermodynamically using a microcalorimetry technique. It is shown that at ph varying from 5,0 to 8,0 the RNAse C2 solution in a cacodylate buffer contains about 30% of monomeric and about 70% of dimeric forms of protein, each of them melting as a single cooperative system. Moreover, studies of the influence of phosphate ions have shown that they stabilize the system by 3-4 degrees and transform it into a monomeric form.     

Segmental distribution of the endocytosis receptor gp330 in renal proximal tubules

The subcellular distribution and segmental variations in location of gp330, a scavenger receptor for filtered proteins in renal proximal tubules, was analyzed. Kidney tissue from rats (4 different strains), rabbits and humans were analyzed by light- and electron microscope immunocytochemistry, using cryosections or Lowicryl sections from cryosubstituted tissue. Gp330 was located mainly in apical coated pits, small and large endocytic vacuoles and in dense apical tubules in the proximal tubule cells. The labeling density was markedly higher in segments 1 and 2 as compared to segment 3 of the proximal tubule. In addition to the location in the early part of the endocytic pathway, gp330 was also present in lysosomes, especially in segments 1 and 2. The lysosomal labeling was not restricted to the membrane, but was also seen in the matrix. Localization of gp330 in lysosomes was confirmed on sections from purified lysosomal fractions from rat renal cortex. The brush border localization of gp330 in proximal tubules exhibited a characteristic segmental variation. In the initial part of segment 1, there was virtually no brush border labeling. In the remaining part of segment 1 and in segment 2, there was a distinct but sometimes patchy labeling of the brush border. In segment 3, groups of microvilli of approximately 10 as seen in sections were intensively labeled from bottom to tip and there were often more than one of these groups on a single cell, the remaining microvilli were unlabeled. No differences in the cellular and subcellular localization of gp330 were observed between species or rat strains. In conclusion, the present study demonstrates that in addition to its location in the early endocytic and recycling pathway, gp330 is also present in microvilli and the protein and degradation products thereof is present in lysosomes, consistent with its role as a protein scavenger receptor.     

The association of population density, reduced space, and uncomfortable temperatures with misconduct in a prison community

This study investigated the relation of population size, amount of personal space, and population density to the incidence of disruptive behavior over a 3-year period in a correctional institution for male youthful offenders. Population size was significantly correlated with the number but not the rate of disciplinary violations. The total amount of personal space and the index of population density were significantly correlated with both the number and the rate of violations. A post hoc analysis showed that the incidence of uncomfortably hot days had no relation to disruptive behavior. These results are contrasted with laboratory data on human crowding reporting no relation between population density and behavior pathology. It is suggested that the chronic high density explored in the present field study differs from temporarily crowded conditions produced in laboratory research on human crowding.