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N Rousseau

Publications and source records attributed to N Rousseau.

At least 37 records · Page 2Linked to original sources
PubMed1993

[In search of nursing practices].

This article is based on a research begun in 1990 to gain a portrait of persons in the various holistic occupations in Québec. From this research, the author came to question the motivation that pushed so many nurses to go into holistic practices. The goal of the research was not to collect specific data about nurses but to identify those individuals now working in holistic therapies. The author summarizes the theoretical framework of the first project and outlines the research methods used. Since the results identified those therapists with a nursing background, it was possible for her to review part of the data to identify certain characteristics of this group. The most popular holistic therapy practised was acupuncture, usually accompanied by complimentary therapies such as relaxation techniques, massage therapy, polarity and therapeutic touch. The author presents the hypothesis that nurses choose this type of practice partly to find a holistic concept that is coherent with health care, and partly to find concrete interventions compatible with traditional nursing values. She is of the opinion that it is not through this type of practice that nurses will find a solution to their professional identity problem. The study consisted of a pre-tested 29 page questionnaire with a total of 89 questions sent to 954 individuals. Not all of the 89 questions were applicable to all the respondents. Of the 954 questionnaires mailed out, 11.8 percent were returned marked "incorrect address". Of the 841 therapists who received the questionnaire, 319 returned completed forms. Of these 319 respondents, 86 individuals indicated they had a nursing education.

Complementary Therapies↗
PubMed1992

Effect of beta-lactams on peptidoglycan metabolism of Haemophilus influenzae grown in animals.

We have examined bacterial determinants that influence beta-lactam activity in Haemophilus influenzae cells cultivated in a system that reproduces in vivo growth conditions. Bacteria grown in diffusion chambers were recovered from the peritoneal cavities of rats, and their cell properties were compared with those of bacteria grown in broth cultures by various tests performed in vitro. The rate of peptidoglycan synthesis was measured as the incorporation of [14C]alanine into cell wall material in the presence of chloramphenicol. The total incorporation of [14C]alanine into peptidoglycan was markedly increased in cells grown in rats prior to the assay but was efficiently reduced by the beta-lactams. The extent of cross-linking was lower in the peptidoglycan of in vivo-grown bacteria, as estimated by sodium dodecyl sulfate- to trichloroacetic acid-insoluble radioactive cell wall material ratios. A whole-cell labeling assay with 125I-penicillin was used to characterize the penicillin-binding proteins (PBPs). Four PBPs showed a striking reduction in the binding of the labeled penicillin in cells grown in rats. Such changes resembled the PBP alterations seen in beta-lactamase-negative clinical strains that were resistant to the beta-lactams. Although ampicillin and moxalactam showed delayed inhibitory activities in vitro for cells collected from rats, cells recovered from beta-lactam-treated rats showed evidence of antibiotic effectiveness (binding of the beta-lactams to PBPs in vivo and altered morphology), and the killing of cells exposed to antibiotics in broth or in peritoneal fluid was equally good. Finally, the frequencies of spontaneous resistance or tolerance to ampicillin or moxalactam were estimated, and there was no significant difference for in vitro- or in vivo-grown cells. These data demonstrated that the cultivation of H. influenzae in animals created changes in PBPs and the overall peptidoglycan metabolism. Such alterations did not impair the bactericidal activities of the beta-lactams, although they resulted in delayed bacterial inhibition, a phenomenon that may have important consequences in antibiotherapy.

Alanine↗
PubMed1992

Molecular basis of the non-beta-lactamase-mediated resistance to beta-lactam antibiotics in strains of Haemophilus influenzae isolated in Canada.

A study recently conducted across Canada showed that 64 of 2,503 clinical isolates of Haemophilus influenzae were resistant to beta-lactams without production of a beta-lactamase (L. D. Tremblay, J. L'Ecuyer, P. Provencher, M. G. Bergeron, and Canadian Study Group, Can. Med. Assoc. J. 143:895-900, 1990). The beta-lactamase-negative strains formed three distinct groups, with ampicillin MICs of 0.5 to 1, 2 to 4, and greater than or equal to 8 micrograms/ml for groups I, II, and III, respectively. We have investigated the mechanisms of resistance for eight strains originating from different infections and geographic areas. These strains were representative of groups I to III. Five strains were nontypeable, two were type B, and one was non-B. Chromosomal DNA extracted from each strain was used to transform the laboratory strain Rd. Transformants were selected on beta-lactam-containing plates and showed the same level of resistance to ampicillin as the donor strains. Differences in outer membrane proteins, porins, and lipopolysaccharide profiles on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) did not change with resistance. Functional analyses of purified porins in artificial lipid bilayer experiments did not explain resistance. Peptidoglycan synthesis was measured by incorporation of [14C]alanine into trichloroacetic acid-insoluble cell wall material in the presence of chloramphenicol. The growth rate and the rate of peptidoglycan synthesis observed for the transformants of the isogenic set did not correlate with resistance. Whole-cell labeling with 125I-penicillin revealed modifications in penicillin-binding proteins (PBPs) among the transformants. In particular, PBPs 3A and 3B (65 and 63 kDa, respectively) showed a decrease in affinity for beta-lactams in all transformants (groups I, II, and III) and correlated with an increased MIC except in the transformant of group III, which showed higher levels of resistance. Partial purification and proteolytic digestion of 125I-penicillin-labeled PBP 3B led to two types of CnBr peptide profiles on SDS-PAGE, the profiles of the transformed strains from groups I and II being different from those of the control group and group III. Finally, electron microscopy revealed a distinct cell filamentation for the group III transformants. These data clearly indicate that changes in PBPs are a common mechanism that results in a significant level of non-beta-lactamase-mediated beta-lactam resistance in H. influenzae despite serotype, origin of isolation, or geographic distribution.

Adolescent↗
PubMed1988

A study of the B-Z transition of the AC-rich region of the repeat unit of a satellite DNA from Cebus by means of chemical probes.

The conformational changes induced by negative supercoiling in the AC-rich region of the repeat unit of a Cebus satellite DNA has been studied by chemical probes sensitive to alterations in DNA conformation. This region is constituted of a (GT/CA)n stretch (15 less than or equal to n less than or equal to 18) associated to a sequence rich in GT/CA. At high superhelical density, at least 100 base pairs in the AC-rich region adopt the Z conformation as judged by diethyl pyrocarbonate reactivity. This is confirmed by diethyl pyrocarbonate footprinting of the complex between antibodies to Z-DNA and the AC-rich region. Osmium tetroxide and hydroxylamine reveal some distortions of the Z double helix in the (GT/CA)n stretch also. The terminal T residues of the stretch are hyperreactive with osmium tetroxide; the terminal left C residues but not the terminal right C residues are hyperreactive with hydroxylamine. Substitution of a few base pairs in the middle of the (GT/CA)n stretch induces also some distortions of the Z double helix. In the GT/CA-rich sequence, distortion of the Z double helix is also supported by the hyperreactivity of osmium tetroxide with several T and C residues.

Animals↗
PubMed1988

Chloroacetaldehyde reacts with Z-DNA.

We show that chloroacetaldehyde, a chemical compound known to be reactive with unpaired adenine and cytosine residues, reacts with adenine residues (syn conformation) but not with cytosine residues (anti conformation) within Z-DNA. These modified residues are sensitive to cleavage by piperidine, which allows mapping at the single nucleotide level.

Acetaldehyde↗
PubMed1987

[Notes on a definition for alternatives practices and therapies in Quebec.].

The phenomenon of non-traditional therapies is firstly analyzed within the context of an increasing number of approaches in the therapeutic field in Quebec and the Western hemisphere and of the development of health care alternatives. The growth and diversity of alternative therapies legitimizes the need to establish an operational definition of this phenomenon, which is the framework of this article.

English Abstract↗
PubMed1986

Nucleotide sequence of an heterochromatic segment recognized by the antibodies to Z-DNA in fixed metaphase chromosomes.

The purpose of this work was to analyse at the molecular level the DNA recognized by the antibodies to Z-DNA in in situ experiments. Antibodies to Z-DNA interact strongly with R-band positive heterochromatic segments of fixed metaphase chromosomes of Cebus (Viegas-Pequignot et al., 1983). These segments are constituted of a satellite DNA the repeat unit of which is about 1520 base pairs long. The base sequence of the repeat unit has been determined. It contains a (AC)n rich region which, in vitro, adopts the Z conformation under topological constraints. Experiments with nuclei suggest that this sequence is not predominantly in the Z conformation in vivo. The polymorphic structure of the (AC)n rich region argues for an active recombination sequence.

Animals↗
PubMed1982

Interaction between antibodies to Z-form deoxyribonucleic acid and double-stranded polynucleotides.

Antibodies to Z-DNA have been elicited in rabbits immunized with chloro(diethylenetriamine)platinum(II)chloride (Cl2dienPt) modified poly(dG-dC).poly(dG-dC). Under physiological conditions this polynucleotide in which 12% of the bases were substituted is in the Z form. The antibodies are mainly immunoglobulins G as shown by gel filtration of the antiserum and by ultracentrifugation of the antibodies purified on a Sepharose--poly(dG-dC).poly(dG-dC) column. From the quantitative precipitin curve, it is concluded that each binding site of the antibody covers four nucleotide residues. The Z-form DNA-antibody complex is stabilized by electrostatic interactions. There was no interaction between poly(dI-br5dC).poly(dI-br5dC) in the Z form and the antibodies, which strongly suggests that the exocyclic amino group of guanine residues in Z-poly(dG-dC).poly(dG-dC) interacts with the antibody binding site. The modification of poly(dG-dC).poly(dG-dC) by 2-(acetylamino)fluorene residues decreases but does not prevent the binding to the antibodies. It is also shown that the polynucleotide poly(dG-br5dC).poly(dG-br5dC) adopts the Z form over a large range of salt concentration [5 mM tris(hydroxymethyl)aminomethane hydrochloride, pH 7.5, to 3 M NaCl].

Animals↗
PubMed1982

Polynucleotide helix geometry and stability. Spectroscopic, antigenic and interferon-inducing properties of deoxyribose-, ribose-, or 2'-deoxy-2'-fluororibose-containing duplexes of poly(inosinic acid) . poly(cytidylic acid).

Circular dichroism, absorbance temperature profiles, antigenic properties, and interferon-inducing capacity of the nine double-stranded complexes between poly(inosinic acid) and poly(cytidylic acid) [(rI)n . (rC)n] and their deoxy- and 2'-deoxy-2'-fluoro-analogues were studied. The complexes containing only ribose or 2'-fluororibose chains showed similar CD spectra and thermal stabilities. Anti-(rI)n . (rC)n antibodies were well recognized by the duplexes containing 2'-fluororibose in either one strand. These two duplexes were also efficient interferon inducers. Presence of fluororibose in both strands decreased the affinity of anti-(rI)n . (rC)n antibodies slightly and abolished interferon-inducing activity. All polydeoxyriboside-containing complexes showed CD spectra significantly different from the previous group; they showed also 40- to 100-times lower affinity for the anti-(rI)n . (rC)n antibodies, and did not induce interferon. It is concluded that the structure of (rI)n . (rC)n, an A-type helix, is little perturbed by substitution of one or both strands by 2'-fluororibose. Substitution by deoxyribose in either strand considerably changes the structure of the helices. The hybrids containing poly(deoxycytidylic acid) retain at least some of the structural features of the B-type helix poly(deoxyinosinic acid) . poly(deoxycytidylic acid).

Animals↗
PubMed1977

Action of monovalent cations on the biological properties of PR toxin, a mycotoxin from Penicillium roqueforti.

PR toxin impairs liver cell metabolism by inhibiting RNA and protein synthesis. In vitro, the drug inhibits the transcription carried out by isolated rat liver nuclei and the translation promoted by polysomes. The action of monovalent cations on the biological activities of PR toxin has been studied. The increased ionic strength due to the presence of salt in the incubation medium, lowers the inhibitory action of PR toxin on in vitro transcription and translation activities; this action is reversible. Besides the overall effect of the ionic strength, ammonium salts possess a specific ability to suppress irreversibly the biological properties of PR toxin (in vivo toxicity and capacity of inhibiting RNA and protein synthesis). The mechanism of this action is discussed.

Ammonium Sulfate↗
PubMed1976

Mechanism of the inhibition of transcription by PR toxin, a mycotoxin from Penicillium roqueforti.

PR toxin, a mycotoxin synthesized by Penicillium roqueforti, impairs the transcriptional process in liver cells; the two main RNA polymerase systems (enzymes A and B) are affected by PR toxin. The toxin does not require an enzymic conversion before interfering with in vitro RNA synthesis. Addition of ammonium sulphate completely prevents the inhibition of transcription by PR toxin. In vitro results, using RNA polymerase purified from E. coli, suggest that PR toxin impairs the activity of the RNA polymerase itself. Regarding the step of the transcription process affected, it is shown that PR toxin inhibits both initiation and elongation of the polynucleotide chain.

Amanitins↗
PubMed1976

Transfer ribonucleic acid methylase activity in adult and foetal rat liver.

Foetal rat liver extracts were found to have higher tRNA methylene activities than corresponding extracts of adult liver. When the specific activities were expressed per mg of liver or per mg of protein, the foetal tRNA methylating enzymes were respectively 2.5 and 6 times higher than those of adult livers. The presence of an inhibitor in adult liver can be excluded, since the same recoveries of total tRNA methylase activity were obtained after partial purification of both adult and foetal liver extracts: yields were close to 100%. The apparent Km's for the substrates in the methylating reactions were the same when tRNA methylases from either adult or foetal liver were used: values were 0.2 muM for Escherichia coli tRNA and 2.1 muM for S-adenosyl-L-methionine. After T1-T2 ribonuclease digestion of an in vitro methylated tRNA, similar methyl nucleotide patterns were observed in foetal and adult enzymatic extracts. It is concluded that the same tRNA methylase pool is present in adult and foetal liver. In addition, it is hypothesized that the different reaction rates exhibited by these enzymes might be due to the tRNA functional requirements rather than to the presence of a tRNA methylase inhibitor.

Animals↗