Biomedical subjects

M Trudel

Publications and source records attributed to M Trudel.

At least 55 records · Page 3Linked to original sources

PubMed1992

Lectin characterization of cystogenesis in the SBM transgenic model of polycystic kidney disease.

The generation of a novel transgenic mouse model of polycystic kidney disease with a construct (SBM) that links the coding region of the c-myc proto-oncogene to the simian virus 40 enhancer and beta-globin promoter was previously reported (see reference 1). In order to determine the site of origin and histogenesis of renal cysts in this model, lectin/immunohistochemical and electron microscopic studies on mice of varying ages (from birth to adulthood) are described here. Cysts are detectable at birth and increase in number and diameter with age. Cysts predominantly involve the collecting tubules of young transgenic mice but progressively affect the proximal tubules with advancing age. A minority of cysts are of distal tubular origin in all age groups studied. Tubular hyperplasias are primarily reactive with proximal tubular markers and appear to precede the development of proximal tubular cysts in adult mice. This particular phenotypic evolution of polycystic kidney disease with advancing age suggests that the cystogenic potential of the transgene is modulated by yet unidentified tubular segment-specific responses.

Animals↗

PubMed1991

Towards a transgenic mouse model of sickle cell disease: hemoglobin SAD.

In order to obtain a transgenic mouse model of sickle cell disease, we have synthesized a novel human beta-globin gene, beta SAD, designed to increase the polymerization of the transgenic human hemoglobin S (Hb S) in vivo. beta SAD (beta S-Antilles-D Punjab) includes the beta 6Val substitution of the beta S chain, as well as two other mutations, Antilles (beta 23Ile) and D Punjab (beta 121Gln) each of which promotes the polymerization of Hb S in human. The beta SAD gene and the human alpha 2-globin gene, each linked to the beta-globin locus control region (LCR) were co-introduced into the mouse germ line. In one of the five transgenic lines obtained, SAD-1, red blood cells contained 19% human Hb SAD (alpha 2 human 1 beta 2SAD) and mouse-human hybrids in addition to mouse hemoglobin. Adult SAD-1 transgenic mice were not anemic but had some abnormal features of erythrocytes and slightly enlarged spleens. Their erythrocytes displayed sickling upon deoxygenation in vitro. SAD-1 neonates were anemic and many did not survive. In order to generate adult mice with a more severe sickle cell syndrome, crosses between the SAD progeny and homozygous for beta-thalassemic mice were performed. Hemoglobin SAD was increased to 26% in beta-thal/SAD-1 mice which exhibited: (i) abnormal erythrocytes with regard to shape and density; (ii) an enlarged spleen and a high reticulocyte count indicating an increased erythropoiesis; (iii) mortality upon hypoxia; (iv) polymerization of hemolysate similar to that obtained in human homozygous sickle cell disease; and (v) anemia and mortality during development.

Anemia, Sickle Cell↗

PubMed1991

Synthetic peptides corresponding to the F protein of RSV stimulate murine B and T cells but fail to confer protection.

We have previously located a major neutralization site of the fusion protein of respiratory syncytial virus (RSV) in the polypeptide region extending from amino acids Ile221 to Glu232. In this report, 8 peptides corresponding to the six major hydrophilic regions of the F1 subunit were selected to analyse their immunogenic and protective capacities as well as their ability to block the high neutralization activities of 4 monoclonal antibodies (MAbs). Only 5 of the 8 peptides tested induced specific antibodies while all induced an in vitro interleukin-2 response of splenocytes from immunized mice. Peptide 3 (Ile221-Phe237) was able to elicit neutralizing antibodies, confirming our previous hypothesis concerning the location of a neutralization site. However, immunization with the latter did not induce significant reduction of virus in lungs of BALB/c mice upon challenge, probably due to an inadequate level of circulating neutralizing antibodies. Interestingly, peptides 2 (Asn216-Glu232), 3 (Ile221-Phe237), and 5 (Ser275-Ile288) blocked in vitro neutralization by four different F1 specific MAbs. A hypothesis is proposed to explain these results.

Amino Acid Sequence↗

PubMed1991

Protection of BALB/c mice from respiratory syncytial virus infection by immunization with a synthetic peptide derived from the G glycoprotein.

A synthetic peptide homologous to amino acids 174-187 of the G glycoprotein of the A2 strain of human respiratory syncytial (RS) virus (G/174-187) was shown to induce protection from live virus challenge of BALB/c mice after immunization with three doses of 50 micrograms of peptide coupled to keyhole limpet hemocyanin. Immunized mice showed high levels of circulating RS-specific antibodies as detected by ELISA assay; however, no neutralizing antibodies were found. Moreover, an important short-term cytotoxic T-cell response was observed with lymphocytes isolated from the lungs but not from the spleen of immunized mice. This response was lost 24 weeks after immunization; however, mice remained protected against challenge with live RS virus. In addition, a monoclonal antibody that specifically binds to peptide G/174-187 was found efficient in conferring passive protection from challenge: this data further supports our results on the importance of the 174-187 region in protection. Another peptide, spanning amino acids 144 to 159, was shown to induce neutralizing antibodies but did not confer protection.

Animals↗

PubMed1991

C-myc as an inducer of polycystic kidney disease in transgenic mice.

In this study, a genetic model of polycystic kidney disease (PKD) has been produced in transgenic mice bearing the murine c-myc gene driven by the SV40 enhancer and the adult beta-globin promoter. These animals reproducibly develop PKD and die of renal failure. The phenotype appears to result from the overexpression of c-myc in the renal tubular epithelium and consequent abnormal cell proliferation. These transgenic mice represent a genetic model of PKD which bears similarities to human autosomal dominant PKD (ADPKD) with respect to renal morphology, renal functional alterations and dominant transmission. Study of these transgenic mice may offer valuable insights into the pathogenesis of PKD.

Animals↗

PubMed1991

Genomic heterogeneities in bovine herpesvirus type 1 viral isolates: a major variant selected from a field isolate.

We have analyzed viral DNA patterns, obtained following digestion of six different infectious bovine rhinotracheitis isolates, using a panel of restriction enzymes. Several differences in profiles were observed, particularly for a Canadian viral strain which presumably contained a genome that was larger than the other five infectious bovine rhinotracheitis genomes. Also, an insertion/deletion of a HindIII restriction site was found in the DNA of a Danish strain; this additional HindIII site was localized precisely within the original HindIII E fragment of the infectious bovine rhinotracheitis virus. Interestingly, results could be used to distinguish each viral strain examined from the others by simple digestion with the appropriate enzyme.

DNA, Viral↗

PubMed1991

Large-cell lymphoma presenting with hepatic sinusoidal infiltration.

We describe a case of large-cell lymphoma of B-cell phenotype with clinicopathologic features resembling malignant histiocytosis. The clinical presentation was characterized by fever, anemia, thrombocytopenia, coagulopathy, and elevated liver enzyme levels. These features and the finding of a predominantly sinusoidal infiltrate of neoplastic cells on liver biopsy raised the suspicion of malignant histiocytosis. The patient subsequently developed supraclavicular lymphadenopathy, which proved to be due to a diffuse large-cell lymphoma. Immunophenotypic studies performed on the lymph node and the original liver biopsy specimen established the B-cell nature of neoplastic cells at both sites. This case highlights a rare pattern of hepatic involvement by large-cell lymphoma, and contrasts the latter with other hematologic disorders associated with hepatic sinusoidal infiltrates.

Aged↗

PubMed1990

Gene mapping of infectious bovine rhinotracheitis viral DNA genome.

A bovine herpesvirus I (BHV-I) HindIII genomic bank spanning 89% of the entire genome was constructed and individual fragments analyzed for their capacity to select specific mRNAs which were then expressed by in vitro translation assays. This procedure allowed the mapping of more than 20 viral polypeptides to discrete regions of the DNA genome. Some polypeptides map in neighboring HindIII fragments while most seem encoded in single fragments. In particular, the coding sequences for an abundant 94 kDa polypeptide, which is the potential unglycosylated precursor of gII glycoprotein, have been assigned to the small 3.6 kbp HindIII genomic fragment M. The localization of structural and non-structural gene-coding sequences will help to characterize viral polypeptides and eventually, a better understanding of BHV-I infection will be gained.

Chromosome Mapping↗

PubMed1990

Towards a mouse model for sickle cell disease: HB SAD.

Very recently a high expression of human hemoglobin S, which causes sickle cell disease, has been obtained in transgenic mice. We have constructed a modified beta S gene, beta SAD which carries two additional mutations in order to induce polymerization of transgenic hemoglobin when diluted by endogenous mouse Hb. The transgenic SAD mice are not anemic but exhibit a low percentage of irreversible sickle cells. Sickling is induced by deoxygenation of erythrocytes in vitro. In addition, the anemia of neonates and the low incidence of SAD animals in the progeny suggest a deleterious effect of SAD Hb during development. Finally, hypoxia induces a high mortality in SAD adults suggesting the induction of vaso-occlusive events.

Anemia, Sickle Cell↗

PubMed1989

Comparison of caprine, human and bovine strains of respiratory syncytial virus.

A new continuous ovine kidney cell line allowing the growth of caprine, human and bovine respiratory syncytial virus was used to minimize host cell related variations for the direct comparison of the viral ultrastructures, serological relationships and structural protein profiles. Results show that all three strains are closely related although a closer relationship was found between bovine and caprine RS.

Animals↗

PubMed1989

Experimental polyvalent ISCOMs subunit vaccine induces antibodies that neutralize human and bovine respiratory syncytial virus.

The purpose of the present study was to evaluate experimentally, in guinea-pigs, the immunogenicity of respiratory syncytial (RS) virus subunit vaccines. Immunostimulating complexes (ISCOMs), made from the surface proteins of both human (Long) and bovine (A-51908) RS strains adsorbed to the adjuvant Quil A, were assayed for their capacity to induce neutralizing antibodies, in comparison to experimental live virus vaccines. Serums from animals vaccinated with either the human or bovine RS subunit vaccines were equally efficient in neutralizing human or bovine RS virus. ISCOMs prepared with bovine RS virus proteins were significantly (p less than 0.05%) more efficient than their human counterpart, in inducing neutralizing antibodies, suggesting their greater potential as a subunit vaccine.

Adjuvants, Immunologic↗

PubMed1989

Rapid detection and identification of Legionella pneumophila by a membrane immunoassay.

Legionella pneumophila was detected and identified by an immunoblot assay using a monoclonal antibody specific to serogroups 1 to 8. Samples containing L. pneumophila were plated on buffered charcoal yeast extract agar supplemented with glycine, vancomycin, and polymyxin B. After incubation at 35 degrees C for 3 days, colonies were transferred to nitrocellulose membranes by blotting. Simultaneous detection and identification of L. pneumophila were done by treating the membrane with the monoclonal antibody and a peroxidase conjugate to mouse immunoglobulins. A diffuse cross-reaction was observed with Pseudomonas fluorescens colonies, but this was a low-level reaction that could easily be differentiated from the strong specific reactions to L. pneumophila.

Collodion↗

PubMed1989

Production and characterization of neutralizing monoclonal antibodies against poliovirus type 1, 2, and 3.

Neutralizing monoclonal antibodies were produced against a reference vaccine or a reference wild strain of poliovirus type 1, 2, and 3. After 26 fusions, 55 monoclonal antibodies were obtained with serotype 1 as the immunizing antigen, 180 with serotype 2, and 115 with serotype 3. The neutralizing activity of these monoclonal antibodies was tested first with the two reference strains and then if reactive, against a panel of 10 well-characterized strains of each serotype, 5 vaccinelike (VL) and 5 nonvaccinelike (NVL). All monoclonal antibodies were type specific without reactivity with any of the heterologous strains. There was a wide range of reactivity within the strains of each serotype. Several monoclonal antibodies to serotype 1 reacted with all type 1 strains, while several neutralized strongly all VL strains and weakly one or more of the NVL strains. Most of the 180 monoclonal antibodies to serotype 2 neutralized to various degrees all strains of this serotype and about half reacted very strongly with all homologous strains whether VL or NVL. None could differentiate all VL and NVL homologous strains. Of the 115 monoclonal antibodies to serotype 3, several monoclonal antibodies neutralize to various levels all homologous strains and some can differentiate VL and NVL strains.

Animals↗

PubMed1989

Concentration of Giardia lamblia cysts, Legionella pneumophila, Clostridium perfringens, human enteric viruses, and coliphages from large volumes of drinking water, using a single filtration.

Poliovirus, coliphages, Giardia lamblia cysts, Clostridium perfringens spores, and Legionella pneumophila were concentrated simultaneously in a single pass by sequential filtration of large volumes of drinking water through 3- and 1-micron wound electronegative fiberglass cartridge filters (25.4 cm). Filtration was performed under acidic conditions (pH 3.5) in the presence of 0.001 M aluminum chloride to enhance adsorption. Elution of all the microorganisms entrapped or adsorbed to the filters was obtained by a slow backwash elution with a 1.5% beef extract solution, pH 9.75, containing 0.5% Tween 80. Tween 80 was shown to enhance recovery of the bacteriophages, bacteria, and parasites. Giardia cysts were efficiently eluted (71%) and could be reconcentrated by low-speed centrifugation and purified by sucrose density gradient flotation at a final recovery of 52%. Legionella pneumophila cells were eluted at 64% and were further concentrated by low-speed centrifugation at an overall recovery of 55%. C. perfringens spores and coliphages were eluted at efficiencies of 82 and 86%, respectively, and reconcentrated with minimal loss by a detergent - protein flotation method. Poliovirus was eluted at 93% and reconcentrated at 78% efficiency by organic flocculation.

Animals↗

PubMed1989

[Pregnancy and work: apropos of sick leave].

A study of sick leave from work during pregnancy has been performed from data collected by Social Security's consulting doctors in 1985. The proportion of sick leave of a duration of less than six months during pregnancy may be estimated to be 18.6% of all the reasons for sick leave for all women aged less than fifty years, and so represents the second highest reason for sick leave after mental diseases. A socio-professional inequality exists with regard to sick leave during pregnancy: the estimated frequency of sick leave for pregnancy is thirteen times higher in workers than in managers, and seven times higher in employees.

Absenteeism↗

PubMed1988

Rapid titration of bovine, caprine and human RS virus by a micro-immunoperoxidase assay using a monoclonal antibody and a permissive ovine kidney cell line.

An indirect immunoperoxidase micro-assay, using a continuous cell line derived from ovine kidney cells (OK) and a previously characterized monoclonal antibody (7C2), specific for an exposed and highly conserved epitope of the fusion protein of different strains of RS virus, was used advantageously to rapidly titrate bovine, caprine and human strains of RSV by either quantal (TCID50) or plaque forming assays. Virus titers, obtained in less than 36 h, were in agreement with those obtained by the conventional plaque assays which required an incubation period of 4 days or more. This assay is also applicable to micro-neutralization of fusion inhibition assays for testing serum or screening monoclonal antibodies.

Animals↗

PubMed1988

Control of infectious bovine rhinotracheitis in calves with a BHV-1 subunit-ISCOM vaccine.

An ISCOM subunit vaccine was prepared by adsorption of purified viral membrane proteins of BHV-1 on the glycoside Quil A and assayed in six-month-old seronegative calves. Groups of five animals were given three intramuscular doses of 50 or 25 micrograms BHV-1/ISCOMs or a commercial attenuated vaccine. Both types of vaccine induced seroconversion: the ISCOM vaccine consistently gave a serological response superior to that of the attenuated vaccine with maximal titres of 1/608 in haemagglutination inhibition and 1/53 in neutralization for the 50 micrograms dose compared to 1/152 haemagglutination units and 1/16 neutralizing titres for the attenuated vaccine. Calves vaccinated with the ISCOM vaccine were protected upon challenge whereas control animals showed signs of respiratory distress, and calves vaccinated with the attenuated vaccine developed only mild respiratory tract infection and mild increased rectal temperature. Virus shedding was reduced 100-fold in the attenuated vaccine group compared to 10,000-fold reduction in the ISCOM vaccine groups. The high level of protection induced indicates the potential of BHV-1/ISCOM as a subunit vaccine.

Animals↗

PubMed1988

Further biological, serological and biochemical characterization of North American, European and Southeast Asian strains of bovine herpesvirus 1 compared with other alphaherpesvirinae members.

Hemagglutination activity, structural protein profiles and neutralization assays were used in a comparative study of bovine herpesvirus 1 strains from the U.S.A., Canada, Great Britain, Denmark and Malaysia with equine, feline and human herpesviruses in order to further characterize the bovine herpesvirus 1 hemagglutinin. Bovine herpesvirus 1 strains of different geographical origins all showed hemagglutinating activity for mouse erythrocytes; furthermore, feline herpesvirus 1 was also shown to hemagglutinate mouse erythrocytes. Analyses of partly purified viruses showed that a distinctive and specific polypeptides profile is associated with each species of herpesviruses used in our study; strains of bovine herpesvirus 1 from North America, Europe and Southeast Asia however, presented a remarkable similarity as to their electrophoretic protein patterns. A protein similar to the 97-kDa bovine viral hemagglutinin was not identified with the hemagglutinating feline herpesvirus. An important neutralization epitope on the bovine viral hemagglutinin was also not found on feline, equine and human herpesviruses but was identified on all bovine strains tested from North America, Europe and Southeast Asia stressing the importance of the bovine hemagglutinin for eventual prophylactic purposes.

Animals↗