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M Trudel

Publications and source records attributed to M Trudel.

At least 91 records · Page 5Linked to original sources
PubMed1986

Immunovirological studies on human respiratory syncytial virus structural proteins.

Immunovirological studies suggest that human respiratory syncytial virus may well be composed of five structural proteins as are other members of the Paramyxoviridae family: the two external membrane glycoproteins H (90 000) and Fo (F1, 49 000; F2, 20 000; disulfide linked), the internal membrane protein M (34 000), the nucleoprotein N (42 000), and a protein (78 000) designated P that could be the equivalent of the polymerase of the morbillivirus and paramyxovirus genus. Neutralizing monoclonal antibodies showed, by immunoprecipitation and immunoblotting, that the fusion protein carries neutralizing epitopes. One monoclonal antibody, which shows a high neutralizing titer, immunoblotted directly with the F1 fragment (49 000) of the fusion protein. Analysis in mice of the immunogenicity of the structural proteins separated on sodium dodecyl sulphate gels indicated that, under our conditions, only the fusion protein dimer Fo and its F1 fragment were capable of inducing neutralizing antibodies.

Animals↗
PubMed1986

Elimination of human enteric viruses during conventional waste water treatment by activated sludge.

The present study was undertaken to determine if viruses were selectively eliminated during waste water treatment. Human enteric viruses were detected at all steps of treatment in a conventional activated sludge waste water treatment plant. Liquid overlays and large volume sampling with multiple passages on BGM cells permitted the detection of poliovirus (serotypes 1, 2, and 3), coxsackievirus B (serotypes 1, 2, 3, 4, and 5), and echovirus (serotypes 3, 14, and 22), as well as reoviruses. The mean virus concentration was 95.1 most probable number of infectious units per litre (mpniu/L) in raw sewage, 23.3 in settled water, 1.4 in effluent after activated sludge treatment, and 40.3 mpniu/L in sludge samples. All samples of raw sewage and settled water, 79% of effluent water, and 94% of sludge samples contained viruses. The mean reduction was 75% after settling and 98% after activated sludge treatment. Poliovirus type 3 was rarely isolated after the activated sludge treatment, but was still detected in about one-third of the sludge samples. Reoviruses and coxsackieviruses were detected at similar rates from all samples and appear to be more resistant to the activated sludge treatment than poliovirus type 3. Poliovirus types 1 and 2 were present in almost every sample of raw sewage and settled water and still found in about half of the effluent and sludge samples, indicating a level of resistance similar to that of reoviruses and coxsackieviruses.

Cell Line↗
PubMed1985

An enteric coronavirus of the rabbit: detection by immunoelectron microscopy and identification of structural polypeptides.

The immunoelectron microscopy (IEM) technique has been used for the detection of a rabbit enteric coronavirus (RECV). Immune serum was prepared in guinea pigs; the viral antigen used for the immunization procedure was obtained from the caecum of a sick rabbit, concentrated by centrifugation and purified on Percoll gradient. In order to identify the viral particles used in the immunization procedure, the protein pattern of the particles was determined by electrophoresis and compared with the pattern of other known coronaviruses. Analysis of structural polypeptides of the purified viral particles revealed a pattern similar to that reported for other coronaviruses. These polypeptides cross reacted with two other coronavirus specific immune sera (IBV and TGE). IEM assay of fecal samples collected from healthy and sick rabbits showed the presence of immune aggregates in specimens from both sick and healthy rabbits. Those aggregates contained viral particles sharing morphological characteristics with other coronaviruses. Furthermore, IEM assay was shown to be more sensitive than a direct EM procedure to detect coronavirus particles in rabbit feces. This assay also allowed the detection of a larger number of chronic carriers.

Animals↗
PubMed1985

E1 glycoprotein of rubella virus carries an epitope that binds a neutralizing antibody.

We identified by immunoprecipitation and Western blot analysis, using a monoclonal antibody that neutralizes rubella virus, that E1 glycoprotein carries an epitope linked with neutralization. Glycosidase treatment of virus does not prevent blotting of this monoclonal antibody with the E1 glycoprotein, dissociating this epitope from the hemagglutination epitope which is linked with the oligosaccharide side chains. We also investigated by Western blot analysis human serum reactivity toward E1 glycoprotein and the two other structural proteins of rubella virus, E2 and C: all positive sera detected E1 and C, irrespective of their titers, indicating the importance of glycoprotein E1 in immunity. Frequent lack of reactivity against E2 might suggest that this glycoprotein is either less exposed or less immunogenic.

Antibodies, Monoclonal↗
PubMed1985

Hemagglutinating activity associated with bovine herpesvirus type 1.

Using C57BL/HPB mouse erythrocytes, hemagglutination has been observed with the Los Angeles and Colorado-1 strains of bovine herpesvirus type 1 and with 12 other Canadian field isolates as well. The specificity of the hemagglutination observed with the viral strains has been confirmed by a hemagglutination-inhibition assay.

Animals↗
PubMed1985

Relative resistance to chlorine of poliovirus and coxsackievirus isolates from environmental sources and drinking water.

Several poliovirus and coxsackievirus isolates from environmental sources were compared with laboratory strains to determine their rate of inactivation by chlorine. All viruses were tested for up to 1,000 min in the presence of an initial free residual chlorine level of ca. 0.4 mg/liter. Coxsackievirus B5 (CB-5) isolates were found to be more resistant to chlorine than coxsackievirus B4 (CB-4), followed by poliovirus 1, 2, and 3 in order of decreasing resistance to chlorine. Environmental isolates of CB-5 were more resistant than the laboratory strain tested, and for two strains 12 and 22% of the input virus was still infectious after 100 min in the presence of free residual chlorine. Although CB-4 isolates were less resistant to chlorine than CB-5 isolates, after 1,000 min of contact 0.01% of the input virus was still infectious. Except for CB-5 isolates, isolates from environmental sources did not appear to be more resistant to chlorine than laboratory strains. Viruses isolated at different phases during the preparation of drinking water were not more resistant to chlorine and must thus have been protected by other mechanisms.

Chlorine↗
PubMed1985

Elimination of viruses and indicator bacteria at each step of treatment during preparation of drinking water at seven water treatment plants.

Seven drinking water treatment plants were sampled twice a month for 12 months to evaluate the removal of indicator bacteria and cytopathogenic enteric viruses. Samples were obtained at each level of treatment: raw water, postchlorination, postsedimentation, postfiltration, postozonation, and finished (tap) water. Raw water quality was usually poor, with total coliform counts exceeding 105 to 106 CFU/liter and the average virus count in raw water of 3.3 most probable number of cytopathogenic units (MPNCU)/liter; several samples contained more than 100 MPNCU/liter. All plants distributed finished water that was essentially free of indicator bacteria as judged by analysis of 1 liter for total coliforms, fecal coliforms, fecal streptococci, coagulase-positive staphylococci, and Pseudomonas aeruginosa. The total plate counts at 20 and 35 degrees C were also evaluated as a measure of the total microbial population and were usually very low. Viruses were detected in 7% (11 of 155) of the finished water samples (1,000 liters) at an average density of 0.0006 MPNCU/liter the highest virus density measured being 0.2 MPNCU/liter. The average cumulative virus reduction was 95.15% after sedimentation and 99.97% after filtration and did not significantly decrease after ozonation or final chlorination. The viruses isolated from treated waters were all enteroviruses: poliovirus types 1, 2, and 3, coxsackievirus types B3, B4, and B5, echovirus type 7, and untyped picornaviruses.

Bacteria↗
PubMed1985

Immunoperoxidase method with human immune serum globulin for broad-spectrum detection of cultivable human enteric viruses: application to enumeration of cultivable viruses in environmental samples.

The detection and enumeration of most cultivable human enteric viruses from water is possible if samples are first inoculated onto a suitable cell line such as MA-104 or BGM. Virus growth is then detected by an indirect immunoperoxidase method with human immune serum globulin as the source of antibody to most enteric viruses. The number of positive cell cultures in the immunoperoxidase assay is used to calculate the virus titer (as a most probable number) in the sample assayed.

Cell Line↗
PubMed1985

Influence of inoculum size, incubation temperature, and cell culture density on virus detection in environmental samples.

The influence of inoculum size and cell culture density on virus titer by cytopathic effect or plaque assay was studied using poliovirus type 1 and BGM (Buffalo green monkey) cells as a model for this evaluation. With a plaque assay system, a linear relationship was observed for an inoculum size of up 1 mL/25 cm2; a marked decrease in the number of plaques was observed when over 1 mL of sample was inoculated on this surface area. Cell culture density also affected virus titer; maximal titers were observed when cells were seeded at 25 000 to 75 000 cells/mL and incubated for 6 days before infection with the virus. Viral density, evaluated as most-probable-number and measured by cytopathic effect under liquid overlay, revealed that the viral titer was similar up to 1 mL inoculum and increased only when over 1 mL was inoculated. Cell density had no significant effect on the viral titer measured by the most-probable-number method and cytopathic effect. Inactivation of inoculum due to an incubation temperature of 37 degrees C for a short period was shown to be minimal for poliovirus type 1, reovirus type 2, coxsackievirus B-5, and the simian rotavirus SA-11. Longer inactivation time led to a 2 logs reduction of the infectious titer of coxsackievirus B-5 (in 48 h) while the other viruses showed a significant reduction in titer only after 96 h.

Animals↗
PubMed1984

Regulation of E.coli phenylalanyl-tRNA synthetase operon in vivo.

The phenylalanyl-tRNA synthetase operon is composed of two adjacent, cotranscribed genes, pheS and pheT, corresponding respectively to the small and large subunit of phenylalanyl-tRNA synthetase. A fusion between the regulatory regions of phenylalanyl-tRNA synthetase operon and the lac structural genes has been constructed to study the regulation of the operon. The pheS,T operon was shown, using the fusion, to be derepressed when phenylalanine concentrations were limiting in a leaky auxotroph mutated in the phenylalanine biosynthetic pathway. Furthermore, a mutational alteration in the phenylalanyl-tRNA synthetase gene, bradytrophic for phenylalanine, was also found to be derepressed under phenylalanine starvation. These results indicate that the pheS,T operon is derepressed when the level of tRNAPhe aminoacylation is lowered. By analogy with other well-studied amino acid biosynthetic operons known to be controlled by attenuation, these in vivo results indicate that phenylalanyl-tRNA synthetase levels are controlled by an attenuation-like mechanism.

Amino Acyl-tRNA Synthetases↗
PubMed1984

Biochemical characterization of the hamster thy mutator gene and its revertants.

The thy- mutator phenotype of Chinese hamster ovary cells is distinguished by increased intracellular levels of dCTP, auxotrophy for thymidine, and elevated spontaneous mutational rates. To determine the biochemical lesion responsible for this complex phenotype, enzymes responsible for the synthesis of dCTP and dTTP were investigated. Levels of ribonucleotide reductase and dCMP deaminase were identical in mutant and wild type strains. In contrast, CTP synthetase activity in extracts from thy- strains was consistently altered in that 50% of enzyme activity was resistant to feedback inhibition by CTP. Additionally, thy- strains obtained by DNA transfection also had CTP-resistant CTP synthetase. Thy+ revertants lost the resistant enzyme, and total activity was reduced. CTP-resistant CTP synthetase was regained in thy- mutants reselected from thy+ revertants, but in these strains all activity was resistant. These experiments demonstrate that the thy- mutator phenotype is a consequence of a mutation of CTP synthetase and suggest that one pathway of reversion to the wild type state is by loss or inactivation of the mutant allele rendering the revertants hemizygous for the gene.

Animals↗
PubMed1984

Ferric chloride flocculation for nonflocculating beef extract preparations.

The addition of 2.5 mM ferric chloride to 0.5% beef extract solution at pH 3.5 was found to be highly efficient in the recovery of seeded poliovirus type 1 (Sabin) or indigenous viruses from environmental samples. This method was extremely useful to reconcentrate viruses from beef extract solutions that did not flocculate at pH 3.5.

Chlorides↗
PubMed1984

Virological examination of drinking water: a Canadian collaborative study.

A collaborative virological survey of drinking water was initiated in three major Canadian urban areas, Montreal, Ottawa, and Toronto. In each selected area, three water purification plants were sampled monthly for up to 18 months. The total population served by all nine plants was about 1 500 000. Samples of raw (100 L) and treated (1000 L) water were examined by virus concentration procedures based on adsorption-elution. Sample concentrates were assayed for cytopathic viruses on BS-C-1 cells and the results were expressed as the most probable number of cytopathic units (MPNCU). Viruses were detected in 57% (0-15.35 MPNCU/L) of the raw water samples from Montreal, 37% (0-46.0 MPNCU/L) in Ottawa, and 33% (0-4.91 MPNCU/L) in Toronto. The majority of isolates were reoviruses, but picornaviruses were also found. All finished waters (177 samples) met bacteriological, turbidity, and residual chlorine standards and were free of detectable viruses.

Canada↗
PubMed1983

Escherichia coli phenylalanyl-tRNA synthetase operon is controlled by attenuation in vivo.

The two subunits of phenylalanyl-tRNA synthetase are made from two adjacent, cotranscribed genes that constitute the pheS,T operon. Three different fusions between pheS,T and lac genes were constructed in order to study the regulation of the pheS,T operon in vivo. We show, using these fusions, that phenylalanyl-tRNA synthetase transcription is derepressed when the level of aminoacylated tRNAPhe is lowered by mutational alteration of the synthetase. The pheS,T operon is also derepressed in strains carrying a trpX mutation. The gene trpX codes for an enzyme that modifies both tRNATrp and tRNAPhe and a mutation in that gene causes derepression of the trp and pheA operons, both of which are controlled by attenuation. The in vivo features of the regulation of pheS,T expression described here in correlation with the DNA sequence and in vitro transcription results described in the accompanying paper by Fayat et al. indicate that phenylalanyl-tRNA synthetase is controlled by attenuation in a way analogous to several amino acid biosynthetic operons.

Alleles↗
PubMed1983

Modified immunoprecipitation procedure for the identification of human respiratory syncytial virus polypeptides.

When analysed by polyacrylamide gel electrophoresis, human respiratory syncytial virus harvested after a one step growth cycle and purified through a continuous sucrose density gradient was shown to be composed of nine structural proteins of 90, 68, 49, 42, 34, 28, 25, 19 an 13 kd. The 90, 49 and 19 kd polypeptides were identified as glycopolypeptides by glucosamine incorporation. A modified immunoprecipitation procedure confirmed the viral specificity of the 49, 42, 28, 25 and 19 kd polypeptides.

Centrifugation, Density Gradient↗
PubMed1983

T cell chronic lymphocytic leukemia with bullous manifestations.

Among chronic lymphocytic leukemias (CLLs), the B cell variant is the most common phenotype. The T cell is rare. A variety of cutaneous manifestations have been reported with B and T cell leukemias. We report a patient who presented with a bullous eruption and who was found to have T cell CLL. Despite different therapeutic approaches, the patient died. The cutaneous histology and autopsy findings are reviewed.

Humans↗