Characterization and macromolecular association of proteoglycans produced by pig arterial smooth muscle cells in culture

1. Medium and cell-layer proteoglycans from pig aorta smooth muscle cells in culture were compared. In both compartments, the main proteoglycans contained chondroitin sulfate-dermatan sulfate chains of 40 kDalton. 2. However, cell-layer proteoglycans differed from those of the medium by the presence of: (a) some small-size proteoglycans; (b) a greater amount of heparan sulfate; (c) chondroitin sulfate-dermatan sulfate enriched in iduronate and in 4 sulfate- (instead of 6 sulfate-) residues. 3. During dissociation-reassociation assays of arterial proteoglycans with exogenous hyaluronate or "aggregate" proteoglycans, the in vitro formation of complexes appeared to involve inter-associations between proteoglycans molecules, in addition to aggregation with hyaluronate.     

Lipoxygenase and cyclooxygenase blockade by BW755C prevents endotoxin-induced hypotension but not changes in glucose metabolism

Arachidonic acid metabolites are mediators of various pathophysiologic events following endotoxin administration. However, their role in the endotoxin-induced increase in glucose metabolism has not been examined. Rats were administered either saline or BW755C (an inhibitor of both the cyclooxygenase and lipoxygenase pathways) 30 min prior to injection of E. coli endotoxin and whole body glucose kinetics assessed using a constant iv infusion of [6-3H] glucose. Treatment with BW755C prevented the endotoxin-induced hypotension and tachycardia. Endotoxin produced characteristic increases in the plasma glucose (23-70%) and lactate (2- to 9-fold) concentrations, as well as elevations in the rate of glucose appearance (34-63%) and metabolic clearance (40-92%). In contrast to the amelioration in hemodynamics, pretreatment with BW755C did not prevent these alterations in glucose metabolism normally seen after endotoxin. BW755C markedly reduced the endotoxin-induced increase in plasma catecholamine concentrations, but levels were still elevated 2- to 4-fold compared to control values. The results suggest that arachidonic acid metabolites mediate the early hypotensive response following endotoxin, but are not by themselves responsible for the elevated rates of glucose production and utilization.     

Insulin and other islet hormones (somatostatin, glucagon and PP) in the neuroendocrine system of some lower vertebrates and that of invertebrates--a minireview

Onto- and phylogenetical studies of the evolution of cells, producing regulatory peptides, belonging to the "hormone families" of insulin, somatostatin, glucagon, and PP (the pancreatic polypeptide), have shown that the islets of Langerhans in vertebrates form a substantial part of the large neuroendocrine system (NES). The NES consists of three major parts, viz. (i) neuronal cells of the central and peripheral nervous systems, (ii) disseminated cells in the mucosa of the alimentary tract (and that of other hollow organs), (iii) the parenchymal cells of the classical endocrine glands. In the NES of coelenterates no evidence of islet hormone production has been obtained, so far. In invertebrates, belonging to the protostomian evolution line, the neuronal parts of the NES predominate markedly, and in the most highly developed phyla, such as artropods and molluscs, clear-cut evidence has been obtained for the presence of cells producing members of the islet hormone families. A "brain-gut axis" for all the four islet hormones is well established in the NES of the pro-craniates, i.e. in the invertebrates of the deuterostomian evolution line. Here, the gut endocrine cells are cells of the disseminated type in the epithelium of the mucosa. A separate islet organ does not occur in the NES until the appearance of the first vertebrates, viz. the Agnatha, some 500 million years ago. Here, a grossly visible islet organ exists, free from exocrine, acinar, pancreatic parenchyma. It is a two-hormone organ with insulin and somatostatin cells only.(ABSTRACT TRUNCATED AT 250 WORDS)     

Studies of ionizing radiation as a promoter of neoplastic transformation in vitro

The induction of malignant transformation was examined in a standard promotion protocol in which BALB/3T3 cells were incubated continuously with tritiated water (3HOH) following acute treatment with various doses of either X-rays or benzo(a)pyrene (BP). In no case was there any evidence that protracted exposure to ionizing radiation from 3HOH enhanced the yield of transformants induced by the primary carcinogen over that predicted if the effects of the two agents were additive.     

A difficult cytogenetic diagnosis of 4p monosomy

Monosomy 4p is rare; cytogenetic diagnosis is difficult when it is not oriented by clinical signs such as severe hypotonia, profound encephalopathy and dysmorphism ("casque de guerrier grec"). Parenteral karyotype is indispensable in case of translocation.     

Marfan disease

After reviewing the main features of the Marfan syndrome (musculoskeletal, ocular, cardiovascular, pulmonary abnormalities), its autosomal dominant inheritance with high penetrance but variable phenotype and presence of "soft" conditions preventing an easy diagnosis, the authors report their own data relevant to 73 probands: ratio of each clinical manifestation, state of 34% of familial cases and display of a paternal age effect in the sporadic cases. The pathogenic defect is unknown as like the location of the gene. The difficulties of the genetic counseling are then approached: unpredictability of the severity and of the prognosis in the unborn children of an affected patient, benefit of the echocardiography in the management of people at risk.     

Gene organization in the region containing a new gene involved in chromosome partition in Escherichia coli.

A new mutation, parC, causing abnormal chromosome segregation was identified in two thermosensitive mutants of Escherichia coli. The thermosensitive growth of the mutants was corrected by pLC4-14 in the Clarke-Carbon collection. This plasmid carries a putative gene which can suppress the cell division defect due to ftsI (pbpB) and has hence been termed sufI (sui). The nearness of parC to metC was confirmed, and cotransduction frequency of parC was 59% with metC and 20% with glc. The parC-sufI region was analyzed by subcloning the chromosome region of pLC4-14. The parC and the sufI gene products were electrophoretically identified as proteins of 75 and 55 kilodaltons (kDa), respectively. The allelism of parC+ on pLC4-14 to parC1215 was confirmed by cloning parC1215. The sufI gene appeared to be dispensable for cell viability, and overproduction of its product caused suppression of ftsI. An essential gene coding for a 25-kDa protein was found between the parC and the sufI gene. These three genes were transcribed in the same direction and may be organized into an operon, with parC to the proximal side and with internal promoters at least for the distal genes. The localization of the gene products was examined in maxicells. The sufI protein was synthesized as a precursor which could be chased into a mature form. The major part of the mature form was found in the soluble fraction. The 25-kDa protein was found almost exclusively in the membrane fraction. The parC protein was associated with the membrane fraction in the presence of Mg2+ but found in the soluble fraction when Mg2+ was sequestered with EDTA.