Histamine stimulates calcium-mediated protein phosphorylation in a colonic epithelial cell line

Protein phosphorylation responses in intact enterocytes were examined by stimulating 32Pi-labeled T84 cell monolayers with histamine and resolving proteins by two-dimensional gel electrophoresis. Histamine increases 32P-incorporation into two acidic proteins of Mr 83,000 and of Mr 29,000, designated p83 and p29. Labeling of p83 and p29 is also increased in cells exposed to ionomycin, but not in cells exposed to vasoactive intestinal peptide under conditions resulting in cAMP-mediated secretion and cAMP-stimulated protein phosphorylation. When T84 cell fractions are incubated with [gamma-32P]ATP, labeling of p83 is stimulated by Ca++, but not by cAMP. Thus, histamine stimulates Ca++-mediated protein phosphorylation during the regulation of Cl- secretion.     

CIRRHOSIS OF THE LIVER—Clinical Course in 2,377 Patients at San Francisco General Hospital

The records of 2,377 patients with Laennec''s cirrhosis were reviewed for the period 1947-1957. The chief presenting symptom was ascites in 46 per cent, bleeding in 23 per cent, coma in 18 per cent, jaundice in 9 per cent, and both jaundice and ascites in 4 per cent. Nearly half of the patients died during the period under study—one-third from hepatic failure, one-third from gastrointestinal bleeding, and one-third from other causes, most of which were related to alcoholism.Massive gastrointestinal bleeding occurred in 21 per cent of the patients at some time in their clinical course, and in the 10 per cent of these in whom ulcer was demonstrated, one-fifth died as a result of the hemorrhage. Of those presumed to be bleeding from esophageal varices, 64 per cent died at the first hemorrhage and 10 per cent at subsequent hemorrhages; 85 per cent of all those who bled from varices were dead at the end of one year, and 91 per cent were dead at the end of three years.The survival curve of a group of patients who bled once and were good operative risks but had received no operative treatment was compared to the survival curve for entire group who survived the first hemorrhage. The three-year survival in the good risk group was 47 per cent; for the group as a whole it was 30 per cent. The difference in mortality rate was primarily due to an increased number of deaths from hepatic failure in the combined group, whereas 60 per cent of the good risk group died of recurrent gastrointestinal hemorrhage.As 86 per cent of those who were to die of gastrointestinal bleeding did so at the first hemorrhage, it was concluded that any decided improvement in the salvage rate achievable by operation must come from some means of diagnostic forecast of the likelihood of bleeding, with resort to prophylactic operation in such cases.     

Identification and characterization of variants of Crithidia luciliae with altered morphological and surface properties

Variants of a cloned laboratory stock of the trypanosomatid parasite Crithidia luciliae have been distinguished from "parental type" organisms. These variants accumulated spontaneously over time as the protozoan was maintained by continuous passage in a chemically defined medium. Cloned lines of these variants have been isolated by plating on nutrient agar and partially characterized on the basis of their growth characteristics in culture, their colony and cellular morphology as well as their surface protein expression. One cloned line consisted of motile, flagellated forms which, unlike "parental type" organisms, did not adhere to the surface of culture flasks. Another cloned line was composed of non-adherent, nonmotile, amastigote-like forms which were further distinguished from "parental type" cells by virtue of their constitutive expression, in nutrient-replete medium, of high levels of a surface membrane associated 3'-nucleotidase/nuclease (3'-N'ase) activity. Both the motile, flagellated and amastigote-like variants, like the "parental type" organisms, exhibited elevated levels of the 3'-N'ase activity upon exposure to purine starvation conditions. The variants described are of potential importance in elucidating the mechanism of induction of the highly regulated 3'-N'ase activity as well as for understanding the cytoskeletal systems and the surface properties of these protozoa.     

PERIZONIUM AND INITIAL VALVE FORMATION IN THE DIATOM NAVICULA CUSPIDATA (BACILLARIOPHYCEAE)1

This paper describes the perizonium and initial valve formation in Navicula cuspidata Kütz., based on light microscope (LM) and scanning electron microscope (SEM) observations. The perizonium consists of concentric over-lapping bands, laid down sequentially at the tips of the expanding biconical auxospore during its elongation. The central perizonial band has fimbriate edges and is considerably more rigid than the more distal bands. During auxospore elongation and the band secretion, the chloroplasts continuously oscillate between the two ends of the cell; this oscillation ceases once the elongation is complete. The initial valves, formed within the perizonium, are molded into the basically biconical shape of the perizonium except for a central flattening of each valve face. In contrast to the raphes in gametangial and vegetative valves which are surrounded by a smooth axial area, the raphes in initial valves lie within a raised ridge running along the apical axis of the valve. The regular pattern of apically oriented ridges on the outer surface of vegetative valves is also lacking on initial valves. Comparison of pore–pore spacing within striae of gametangial valves, initial values and post-initial valves (first division and vegetative cells) reveals that the pore–pore distance within striae is conserved at all sexual stages. However, the distance between striae is considerably larger in initial valves than in gametangial and post-initial valves. Vegetative interstriae spacing as well as the planar morphology of the valve face is regained at the first division of the initial cell. This suggests that the spacing between striae is dependent on the sexual stage of the cell during valve formation (i.e. not directly dependent on the cell size) and can be altered independently of the pore–pore spacing.