Characterization of predominant bacteria from the colons of normal and dysenteric pigs.

Bacterial populations adherent to the mucosa of the proximal colons of weaned, healthy pigs were compared with populations from pigs with dysentery induced by inoculation with a culture of Treponema hyodysenteriae. Isolates (136) representative of the predominant flora adherent to colonic epithelia of normal pigs and isolates (162) from pigs with dysentery were cultured anaerobically on a rumen fluid-based medium and characterized. Most (71%) of the isolates from colonic epithelia of normal pigs were gram positive, whereas 88% of the epithelia-associated isolates from pigs with dysentery were gram negative. The geometric mean of colony counts was 5.7 X 10(7)/cm2 of colonic tissue from three normal pigs and 7.7 X 10(8)/cm2 from four pigs with dysentery. A number of isolates obtained from contents of the lumens of normal pigs with dysentery were also characterized. Comparison of isolates from epithelial tissue and from contents of the lumens of the same pig indicated that these populations were different. Our results indicate that physiological changes that occur in the colons of pigs with dysentery are accompanied by marked changes in the microbial populations in the colons. The factors which regulate the population changes are not yet understood.     

Saccharomyces cerevisiae synthesizes proteins related to the p21 gene product of ras genes found in mammals.

A family of normal vertebrate genes and oncogenes has been called the ras gene family. The name ras was assigned to this gene family based on the species of origin of the viral oncogenes of the rat-derived Harvey and Kirsten murine sarcoma viruses. There are now three known functional members of the ras gene family, and genes homologous to ras genes have been detected in the DNA of a wide variety of mammals and in Drosophila melanogaster. Prior experiments have detected proteins coded for by ras genes in a large number of normal cells, cell lines, and tumors. We report here the detection of ras-related proteins in D. melanogaster, a result predicted by the earlier detection of ras-related genes in the Drosophila genome. We also report for the first time the detection of ras-related proteins in a single-cell eucaryocyte, Saccharomyces cerevisiae. These proteins, approximately 30K in size, are recognized by both a monoclonal antibody which binds to the p21 coded for by mammalian ras genes and a polyclonal rat serum made by transplanting a v-Ha-ras-induced tumor in Osborne-Mendel rats. The p21 of v-Ha-ras and the 30K proteins from S. cerevisiae share methionine-labeled peptides as detected by two-dimensional tryptic peptide maps. The results indicate that S. cerevisiae synthesizes ras-related proteins. A genetic analysis of the function of these proteins for yeast cells may now be possible.     

Oxygen participation in the in vivo and in vitro aging of collagen fibres

We have examined, as a function of oxygen concentration, the in vivo and in vitro aging rates of tendon from animal species with widely differing life-spans. The results suggest that concomitant with the genetically determined aldimine type cross-linking reactions which probably are complete by the time the animal has reached physiological maturity, there is an on-going oxygen-mediated system of reactions which also effectively cross-link the structure. These reactions appear to proceed with their own intrinsic rate dependent only upon oxygen concentration, and independent of the particular species involved. They may not be required by connective tissues, but are an unavoidable consequence of the presence of free oxygen in tissues with a low rate of turnover.     

Melampolides from Enhydra fluctuans var. Fluctuans

The investigation of the aerial parts of a variety of Enhydra fluctuans afforded in addition to 4-hydroxyfarnesyl acetate and fluctuadin five new melampolides elucidated by high field ¹H NMR spectroscopy. The chemotaxonomic situation is discussed briefly.     

A dimeric germacranolide and other sesquiterpene lactones from Mikania species

The investigation of two Mikania species, both previously placed in the genus Kanimia, afforded in addition to known compounds several new germ     

Comparison of the alpha-mannosidases in fibroblast cultures from patients with mannosidosis and mucolipidosis II and from controls.

Normal human spleen contains two forms of membrane-bound beta-glucosidase, distinguishable by their thermostability and kinetic properties. The spleen from a patient with adult Gaucher's disease was deficient in the major, thermolabile, form of the enzyme.     

Polyploidy in the Australian leptodactylid frog genus Neobatrachus

Karyotypic analysis of six species of the Australian leptodactylid frog genus Neobatrachus showed that N. pictus, N. centralis, N. pelobatoides and N. wilsmorei are diploid (2n=24) while N. sudelli and N. sutor are tetraploid (4n=48). Polyploidy has not been reported previously among Australian anurans. Idiograms of the six species indicate that they are similar to the other Australian leptodactylids so far discribed. DNA values of the tetraploids are approximately double the values for diploids. Tetraploid nuclear and cell sizes are greater compared with diploids but total body size shows no increase. At diakinesis in primary spermatocytes of tetraploids, mainly tetravalents together with a few bivalents are present. Silver staining of metaphase spreads clearly demonstrates the location of NORs at the secondary constrictions and their frequent association in the tetraploid N. sutor. Nucleolar number in interphase nuclei provides a reliable guide for distinguishing tetraploid from diploid frogs in the absence of chromosome analysis and can be determined for both living and preserved specimens. The possible origins and relationships of the tetraploid species are discussed.     

Gs, an allele of chickens for endogenous avian leukosis viral antigens, segregates with ev 3, a genetic locus that contains structural genes for virus.

Gs is an allele of chickens for the expression of endogenous avian leukosis virus-related core (gs) and envelope (chf) antigens. Progeny of a genetic cross in which Gs was segregating were analyzed for endogenous viral DNA as well as for the expression of endogenous viral antigens. Viral genetic information was identified by cleavage of embryo DNA with restriction endonucleases, electrophoretic separation of the resulting fragments, and identification of bands containing viral sequences by hybridization of the DNA to 32P-labeled viral RNA. Four different chromosomal sites of residence of endogenous viral sequences were identified by this method. These sites were the same as those previously assigned to the endogenous viral loci ev 1, ev 3, ev 4, and ev 5. ev 1 was present in all of the progeny of the cross. ev 3, ev 4, and ev5 were present in various combinations with ev 1. ev 3 cosegregated with the gs+chf+ phenotpye. Cells which did not contain ev 3 but contained ev 1, ev 4, and/or ev 5, did not express detectable levels of viral antigens. We suggest that Gs contains the structural genes for endogenous virus which reside at ev 3 and that these structural genes code for gs and chf in gs+chf+ cells.     

Acute pulmonary hemodynamic effects of intravenous copper sulfate: role of alpha-adrenergic system

We investigated the acute pulmonary hemodynamic effects of intravenous copper sulfate (CuSO4) infusion and its mechanism of action in six groups of conscious sheep (total 40). After 300 mg CuSO4 alone, mean pulmonary artery pressure (Ppa) increased from 10.3 to 22.5 Torr and pulmonary artery wedge pressure (Ppaw) from 3.5 to 7.6 Torr, whereas systemic arterial pressure (Psa) increased from 95 to 102 Torr. Cardiac output (Qp) decreased from 4.7 to 3.3 l/min. Pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR) increased to 320 and 160% of base line, respectively. The hemodynamic changes correlated well with serum copper, which increased from a base-line value of 0.12 to 3.5 mg/dl after the CuSO4. Serum dopamine beta-hydroxylase increased from 3.2 U/l before CuSO4 injection to 5.7 after its administration, signifying activation of adrenergic nervous system. H1-histamine receptor blockade with chlorpheniramine failed to prevent the effects of CuSO4. Pretreatment with methysergide, a serotonin antagonist, partially attenuated the effects of CuSO4. Phenoxybenzamine, an alpha-adrenergic receptor blocker, and 6-hydroxydopamine, a catecholamine depleting agent, completely blocked the effects of CuSO4. beta-Adrenergic receptor blockade with propranolol enhanced the effects of CuSO4. We conclude, that, in conscious sheep, acute infusion of CuSO4 caused a marked reversible increase in PVR with a slight transient increase in SVR, and this pulmonary hypertension was produced by stimulation of the alpha-adrenergic nervous system.