摘要:

A multicapsid nuclear polyhedrosis virus (MNPV) of the Douglas-fir tussock moth,Orgyia pseudotsugata, propagated in larvae of the white-marked tussock moth,O.leucostigma, was successfully grown in two continuous cell lines developed from minced neonate larvae ofO.leucostigma. Polyhedral inclusion bodies (PIBs) appeared in the nuclei of cells within 24 h after inoculation. Cytopathological changes, as revealed by light and electron microscopy, were typical of an MNPV. The virus has been passaged in the cell cultures 55 times. The level of infection during passaging has varied from 15 to 98% of the cells, and the number of PIBs per cell from 10 to 40. The PIBs from the fourth passage of the virus in cell cultures were almost as pathogenic toO.leucostigmalarvae as the PIBs produced in larvae.

ISSN:0008-4166    

DOI:10.1139/m81-178

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Membrane-associated cytidine 5′-diphospho-1,2-diacyl-sn-glycerol (CDP-diacylglycerol):L-serineO-phosphatidyltransferase (phosphatidylserine synthase, EC 2.7.8.8.) and CDP-diacylglycerol:myo-inositol phosphatidyltransferase (phosphatidyl-inositol synthase, EC 2.7.8.11) were solubilized from the microsomal fraction ofSaccharomyces cerevisiae. A variety of detergents were examined for their ability to release phosphatidylserine synthase and phosphatidylinositol synthase activities from the microsome fraction. Both enzymes were solubilized from the microsome fraction with Renex 690 in yields over 80% with increases in specific activity of 1.6-fold. Both solubilized enzymatic activities were dependent on manganese ions and Triton X-100 for maximum activity. The pH optimum for each reaction was 8.0. The apparentKmvalues for CDP-diacylglycerol and serine for the phosphatidylserine synthase reaction were 0.1 and 0.25 mM, respectively. The apparentKmvalues for CDP-diacylglycerol and inositol for the phosphatidylinositol synthase reaction were 70 μMand 0.1 mM, respectively. Thiore-active agents inhibited both enzymatic activities. Both solubilized enzymatic activities were thermally inactivated at temperatures above 30 °C.

ISSN:0008-4166    

DOI:10.1139/m81-179

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

The successful production of disease in mice by a type III group B streptococcus is described in this report. When injected intravenously, 106organisms produced a fulminating sepsis and resulted in 100% mortality within 48 h. Inoculation of 108–109organisms directly onto the surface of the oropharynx progressed to bacteremia and meningitis in greater than 50% of animals. It*** a group of mice treated with penicillin immediately after oropharyngeal inoculation, the incidence of invasive bacteremia was reduced to 30%. The use of this animal model for studying the pathogenesis and treatment of experimentally produced meningitis and eradication of oropharyngeal colonization is discussed.

ISSN:0008-4166    

DOI:10.1139/m81-180

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Scrapings ofCandida albicansplaques from the tongue and buccal mucosa of patients with oral candidiasis were examined electron microscopy. In addition, urine sediment from patients with infection of their catheterized urinary tracts was similar examined. Three types ofC.albicans– oral epithelial cell interactions were noted: a loose adherence apparently mediated by ruthenium red positive matrix, a "tight" adherence where no space could be seen between the host and yeast cell, and invasions host cells by yeast hyphal elements. Adhesion ofCandidablastospores to hyphal elements and adhesion of bacteria toCandidacells was also frequently observed.Urine sediments from patients with mixed bacteria–yeast infections demonstrated adhesion of the bacteria to the yeast cells. This phenomenon was also demonstrated inin vitroexperiments and fibrous ruthenium red material invariably occupied the zo*** of adhesion.Phagocytosis of yeast by polymorphonuclear leukocytes was found in urinary, but not in oral, candidiasis. Ourin vivoandvitroobservations indicate that a ruthenium red positive matrix covers the surfaces involved in the yeast to yeast, yeast to ho and yeast to bacteria adhesion.

ISSN:0008-4166    

DOI:10.1139/m81-181

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Diurnal shifts in the predominant species of heterotrophic bacteria in a freshwater river have been detected by numerical taxonomy testing procedures. Owing to the modifications in the database which were required to accommodate the range of species in a natural system, it was necessary to substantiate the genetic homology of the clustering procedure. DNA hybridization of a cluster ofAeromonas hydrophilastrains indicated that the cluster was 88.6% genetically homologous. The numerical methods grouped strains by physiological characteristics and this phenotypic similarity did not always coincide with the genetic relatedness of the strains. However, the diurnal changes in the predominant bacterial types can be demonstrated effectively by the database.

ISSN:0008-4166    

DOI:10.1139/m81-182

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Ultraviolet (UV) irradiation of type I poliovirus resulted in a modified (M) particle that had lost infectivity, lacked ability to adsorb to HeLa cells, lacked VP4, and was reduced in S value. Additional irradiation resulted in the loss of VP2, further reduction in S value, and permeability of the capsid to RNAse, This particle (C) as well as M contain the genome. Acid pH (5.5–6.5) and sulfhydryl-reducing substances (dithiothreitol, reduced glutathione, andL-cysteine) inhibited UV-induced modification of the capsid. UV irradiation at alkaline pH (7.5–8.5) resulted in more extensive modification of the capsid than irradiation at neutral pH. Ionic compounds were found to inhibit the modifying reaction.

ISSN:0008-4166    

DOI:10.1139/m81-183

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

The complex interrelationships between the transport of inorganic cations and C4dicarboxylates were examined using mutants defective in potassium transport and retention, divalent cation transport, or phosphate transport. The potassium transport system, studied using86Rb+as a K+analogue, kinetically appeared as a single system (Km200 μMfor Rb+,Ki50 μMfor K+), the activity of which was only slightly reduced in K+retention mutants. Divalent cation transport, studied using54Mn2+,60Co2+, and45Ca2+, was more complex being represented by at least two systems, one with a high affinity for Mn2+(Km2.5 μM) and a more general one of low affinity (Km1.3–10 mM) for Mg2+, Mn2+, Ca2+, and Co2+. Divalent cation transport was repressed by Mg2+, derepressed in K+retention mutants, and defective in Co2+-resistant mutants. Phosphate was required for both divalent cation and succinate transport, and phosphate transport mutants (arsenate resistant) were found to be defective in both divalent cation and succinate transport. Divalent cations, especially Mg2+and Co2+, decreasedKmfor succinate transport approximately 20-fold over that achieved with K+; neither cation was required stoichiometrically for succinate transport.The loss of divalent cation transport in cobalt-resistant mutants has been correlated with the loss of a 55 000 molecular weight membrane protein. Similarly, the loss of phosphate transport in arsenate-resistant mutants has been correlated with the loss of a 35 000 molecular weight membrane component.

ISSN:0008-4166    

DOI:10.1139/m81-184

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Crude extracts ofRhizobium japonicumcontained a single superoxide dismutase (SOD) as revealed by polyacrylamide gel electrophoresis.Rhizobium japonicumSOD was determined to be iron-containing by criteria of sensitivity to 5 mMH2O2and 1 mMNaN3. Growth media strongly influenced SOD activity. The addition of methyl viologen to cultures ofR.japonicum61A76NS, growing in complex medium, caused induction of the enzyme. Yeast extract was essential for induction of SOD. Puromycin blocked the induction of the enzyme.Rhizobiumspp. were surveyed for SOD activity, electrophoretic mobility on polyacrylamide gels, and metal content.

ISSN:0008-4166    

DOI:10.1139/m81-185

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Cladosporium resinaewas grown on glucose and then transferred to medium with glucose or with kerosene as the sole carbon source. Growth on hydrocarbon was associated with thinner cell walls in both hyphae and spores, with the presence of large vacuoles in cells, with the synthesis of microbodies, and with increased synthesis of catalase. Some vacuoles in hydrocarbon-grown cells contained small, spherical, electron-dense inclusions which were not observed in cells from glucose medium. Large, electron-dense bodies within vacuoles were observed in glucose-grown and in hydrocarbon-grown cells. A working model is proposed for oxidation ofn-alkanes byC.resinae.

ISSN:0008-4166    

DOI:10.1139/m81-186

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Moose (Alces alces americanaClinton) blood collected by hunters during the 1977 and 1978 hunting seasons was tested for California group antibodies. Hemagglutination inhibition (HI) tests using snowshoe hare virus (SSH) as antigen yielded 37.02% HI-positive sera. Neutralization tests showed reactors (67.5% positive) to SSH and classified six reactors as Jamestown Canyon virus (JC). This study reports the first finding of JC in a moose population; it also provides the first evidence of JC in Atlantic Canada and supports previous findings of SSH in Nova Scotia.

ISSN:0008-4166    

DOI:10.1139/m81-187

出版商:NRC Research Press    

年代:1981

数据来源: NRC