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S Gosselin

Publications and source records attributed to S Gosselin.

15 recordsLinked to original sources
PubMed2000

Impact of a specific program focusing on the psychological autonomy and actualization of potential of residents in a long term care unit.

In 1996, the Sherbrooke Geriatric University Institute introduced a specific health and services program focusing on actualization of potential and psychological autonomy designed for long term care clients presenting few or no cognitive deficits. Some 30 residents who met specific criteria were moved to the same unit. To determine the impact of this specific program on the residents, a study was done using a quasi-experimental design with a control group. The residents in the experimental and control groups were evaluated three times: at the beginning of the program (1996), 1 year (1997) and 2 years (1998) later. The main variables measured were: actualization of potential, psychological autonomy, psychological well-being, satisfaction with care and services, social relations, and perception of the freedom allowed by the institution in regard to their choices and decisions. The results indicate that the new program had no effect on the residents' psychological autonomy, actualization of potential and social relations. In addition, the residents in the experimental group indicated less well-being and less satisfaction than those in the control group. Despite these negative elements, the experimental residents like being and want to stay together on the same unit but seem somewhat concerned about the program objectives. These results led the research team to propose that the program objectives and activities be reviewed.

Journal Article↗
PubMed1996

The myocardial lesions produced by the potassium channel opener aprikalim in monkeys and rats are prevented by blockade of cardiac beta-adrenoceptors.

Aprikalim is a potent, specific, and selective opener of ATP-sensitive K+ (KATP) channels. By virtue of this pharmacological property, aprikalim affords cardioprotection in experimental models of ischemia/reperfusion injury, and, at higher doses, also causes peripheral or coronary vasodilatation. Direct-acting peripheral vasodilators can cause myocardial lesions, particularly in rats and dogs. However, unexpectedly, aprikalim produced this effect also in monkeys. Thus, the primary aim of this investigation was to assess whether in monkeys these myocardial lesions were the direct or indirect consequence of the vascular effects of aprikalim. Cynomologus monkeys were given the beta-adrenoceptor antagonist nadolol (2 mg/kg p.o., twice daily) for 4 consecutive days. On the third and fourth day of the experiment, they received aprikalim (1 mg/kg p.o.). In another series, two monkeys carrying telemetry transmitters for blood pressure and heart rate measurements were also given aprikalim or its vehicle. Finally, aprikalim (1 mg/kg p.o. for 2 days) or its vehicle was administered to rats which were concurrently treated with the beta-adrenoceptor antagonist atenolol (5 mg/kg s.c.) or its vehicle. In cynomologus monkeys, aprikalim produced focal and multifocal myocardial necrosis of minimal to moderate intensity in or near the papillary muscles of the left ventricle. These effects were abrogated by nadolol. Similarly, necrotic lesions were caused by aprikalim only in those rats which had not been pretreated with atenolol. In monkeys, aprikalim produced a marked and long-lasting decrease in aortic blood pressure, accompanied by an even more prolonged tachycardia. These results demonstrate that aprikalim can produce myocardial necrosis not only in rats but also in monkeys. To our knowledge, this is the first time that such adverse effects are reported for a vasodilator in monkeys. More importantly, these effects were prevented by blocking cardiac beta-adrenoceptors. Thus, the myocardial lesions produced by aprikalim may be attributed to its profound and prolonged hemodynamic effects.

Adrenergic beta-Antagonists↗
PubMed1996

Acceptor hydroxyl group mapping for human milk alpha 1-3 and alpha 1-3/4 fucosyltransferases.

Two different fucosyltransferases (Fuc-Ts) have been isolated from human milk, an alpha 1-3 Fuc-T and an alpha 1-3/4 Fuc-T, for mapping of their acceptor binding sites. Kinetic studies employing a series of monodeoxygenated and modified Gal beta 1-->4Glc-NAc beta OR and Gal beta 1-->3GlcNAc beta OR acceptor substrates showed that modifications are tolerated at every hydroxyl group in these substrates except for 6-OH of galactose and 3- or 4-OH of N-acetylglucosamine. Deoxygenation at these positions rendered these compounds inactive as both substrates and inhibitors. These essential hydroxyl groups, which are required for recognition of the substrates, are identical to the key polar groups that have previously been reported for cloned FucTs III, IV and V.

Fucosyltransferases↗
PubMed1994

HTLV-I/II infection in a high viral endemic area of Zaire, Central Africa: comparative evaluation of serology, PCR, and significance of indeterminate western blot pattern.

The frequency of indeterminate Western blot (WB) seroreactivities against HTLV-I "gag encoded proteins" only, and the use of low specific diagnostic WB criteria led to the overestimation of HTLV-I seroprevalence in initial studies in intertropical Africa and Papua New Guinea. In order to clarify the meaning of such seroreactivity, 98 blood samples of individuals from a high HTLV-I endemic area in Zaire, Central Africa were studied by a WB assay containing HTLV-I disrupted virions enriched with a gp 21 recombinant protein and a synthetic peptide from the gp 46 region (MTA-1), and by the polymerase chain reaction (PCR) with 3 primers pairs and 4 different HTLV-I and or HTLV-II-specific probes. These 98 samples were taken mainly from patients with neurological diseases and from their relatives. Using stringent WB criteria, 28 sera (29%) were considered as HTLV-I-positive, 3 as negative and 67 (68%) as indeterminate. A large proportion of these indeterminate sera would have been considered as HTLV-I-positive samples according to previous low specific WB diagnostic criteria. After PCR, 35 samples (36%) were considered as positive for the presence of HTLV-I proviral DNA. Out of the 67 WB seroindeterminate, 10 (15%) were found HTLV-I-positive by PCR. These 10 individuals exhibited in WB multiple band reactivity with p19 and/or p24 (7 cases of both) associated in 6 cases with rgp 21, but never with MTA-1. No samples were found PCR-positive for HTLV-II despite the findings of 11 sera suggestive of HTLV-II by WB.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

A continuous spectrophotometric assay for glycosyltransferases.

This paper describes a continuous spectrophotometric assay for glycosyltransferases. In this assay, a nucleotide diphosphate is coupled to NADH oxidation via pyruvate kinase and lactate dehydrogenase. The nucleotide diphosphate is produced either directly during the glycosyltransferase mediated reaction, or indirectly by the production of a nucleotide monophosphate during the glycosyltransferase mediated reaction, and subsequent conversion of the nucleotide monophosphate to nucleotide diphosphate using nucleoside monophosphate kinase. Using this assay, kinetic parameters for fucosyl-, sialyl-, and N-acetylglucosaminyltransferases were determined. The assay not only allows continual monitoring of the enzymatic reaction, but is rapid and allows the processing of 96 samples at once since it is performed in 96-well microtiter plates. In addition, the procedure provides a means of monitoring the activity of these enzymes using sugar-nucleotide donor analogs, where radiochemical procedures cannot be used.

Cytidine Monophosphate N-Acetylneuraminic Acid↗
PubMed1994

Detection of 100 molecules of product formed in a fucosyltransferase reaction.

We present the detection of 100 molecules of enzyme substrate and product. A fucosyltransferase and a fucosidase were used to add and remove, respectively, a monosaccharide from a synthetic oligosaccharide fluorescently labelled with tetramethylrhodamine. The reaction was followed by use of capillary zone electrophoresis, to separate the product and reactant, with laser-induced fluorescence detection. These are the most sensitive enzyme assays reported to date and six orders of magnitude more sensitive than any reported for these two enzymes. This simple technology allows high-sensitivity determination of the activity of any enzyme for which a fluorescent substrate can be synthesized, and brings within reach the ability to assay glycosyltransferase activities in single cells.

Carbohydrate Conformation↗
PubMed1992

Flavobacterium meningosepticum peptide:N-glycosidase: influence of ionic strength on enzymatic activity.

Flavobacterium meningosepticum peptide:N-glycosidase-mediated deglycosylation of N-linked glycan strands of glycoproteins has been found to be strongly influenced by the ionic strength of the assay medium. By use of a modification of a previously published assay procedure for quantitative analysis of glycan release we have been able to improve reproducibility and thus to compare the extent of deglycosylation achieved under a variety of conditions of ionic strength. We have observed that enzyme activity is adversely affected by high ionic strength buffers such as those recommended for deglycosylation of various glycoproteins and recommend the use of low ionic strength buffers for routine use.

Amidohydrolases↗
PubMed1991

Plasma exchange in polyneuropathy associated with monoclonal gammopathy of undetermined significance.

BACKGROUND: Polyneuropathy associated with monoclonal gammopathy of undetermined significance (MGUS) has been treated with plasma exchange, intravenous immune globulin, and chemotherapy, but the effectiveness of these treatments remains uncertain. METHODS: We randomly assigned 39 patients with stable or worsening neuropathy and MGUS of the IgG, IgA, or IgM type to receive either plasma exchange twice weekly for three weeks or sham plasma exchange, in a double-blind trial. The patients who initially underwent sham plasma exchange subsequently underwent plasma exchange in an open trial. RESULTS: In the double-blind trial, the average neuropathy disability score improved by 2 points from base line (from 62.5 to 60.5) in the sham-exchange group and by 12 points (from 58.3 to 46.3) in the plasma-exchange group (P = 0.06). A similar difference was observed in the weakness score, a component of the neuropathy disability score (improvement, 1 and 10 points, respectively; P = 0.07). After treatment the summed compound muscle action potentials of motor nerves were 1.2 mV lower (worse) than at base line in the sham-exchange group and 0.4 mV higher (better) in the plasma-exchange group (P = 0.07). The greater degree of improvement with plasma exchange was equal in magnitude to or greater than the difference between not being able to walk on the heels or toes and being able to perform these activities. Changes in the vibratory detection threshold, summed motor-nerve conduction velocity, and sensory-nerve action potentials did not differ significantly between the treatment groups. In the open trial, in which patients who initially underwent sham exchange were treated with plasma exchange, the neuropathy disability score (P = 0.04), weakness score (P = 0.07), and summed compound muscle action potentials (P = 0.07) improved more with plasma exchange than they had with sham exchange. In both the double-blind and the open trial, those with IgG or IgA gammopathy had a better response to plasma exchange than those with IgM gammopathy. CONCLUSIONS: Plasma exchange appears to be efficacious in neuropathy associated with MGUS, especially of the IgG or IgA type.

Action Potentials↗
PubMed1991

Neuropathy associated with monoclonal gammopathies of undetermined significance.

Monoclonal proteins (IgM, IgG, and IgA) in the serum or urine of patients with neuropathy may provide a marker for amyloidosis, myeloma, lymphoma, leukemia, Waldenström's macroglobulinemia, or monoclonal gammopathy of undetermined significance (MGUS). The clinical characteristics, course, and electromyographic features among neuropathies associated with monoclonal IgM (IgM-MGUS, 31 patients), monoclonal IgG (IgG-MGUS, 24 patients), and monoclonal IgA (IgA-MGUS, 10 patients) evaluated between 1980 and 1986 were compared. Four statistically significant differences set IgM-MGUS neuropathies apart from IgG-MGUS and IgA-MGUS neuropathies: (1) higher frequency of sensory loss and ataxia, (2) higher frequency of nerve conduction abnormality--10 attributes were significantly worse (none were significantly better), (3) higher frequency of dispersion of the compound muscle action potential, and (4) higher frequency of IgM-MGUS in the MGUS neuropathy cohort than is characteristic of MGUS without neuropathy seen at our institution or than is encountered in epidemiological surveys. These differences were not thought to be due to selection or severity biases. Neither the amount of IgM nor the estimated size of the monoclonal peak was associated with severity of neuropathy. The type and severity of IgM-MGUS neuropathies with anti-myelin-associated glycoprotein antibodies were not significantly different from those without anti-myelin-associated glycoprotein antibodies. A simple relationship between the presence and amount of IgM-MGUS or anti-myelin-associated glycoprotein antibodies and neuropathy cannot be assumed.

Action Potentials↗
PubMed1989

Expression of the ras-related rap genes in human tumors.

The expression of the recently described rap genes, closely related in the effector region to the ras proto-oncogenes, was examined by Northern blot analysis in 41 primary human tumors. The structural and in vitro biological properties of the rap gene products suggest their possible antagonistic action in the same effector pathway as the ras proteins. In order to determine whether a deregulation in the rap transcription levels could be involved per se in the multistep carcinogenic process, we chose to analyze tumors for which the ras mutation rate was previously reported to be extremely rare or unknown, i.e., non-Hodgkin's lymphomas, certain types of carcinoma, sarcomas, germinal neoplasms of the testes and various tumors of the nervous system. A severe decrease in the expression of the rap1A gene was shown in the fibrosarcomas and the adenocarcinoma of the salivary gland studied, as compared to their normal counterparts, whereas no rap2 expression was found in the polyadenylated RNA of sarcoma samples.

Blotting, Northern↗
PubMed1989

Rabbit blastocoelic fluid regulation of tumor-cell proliferation in vitro.

To determine whether rabbit blastocoelic fluid could inhibit tumor-cell proliferation, day-9 and day-12 embryonic fluids, together with autologous and homologous sera, were collected from pregnant or pseudopregnant rabbits and tested against 13 different cell lines and on human carcinoma cells in primary culture. An inhibitory effect on cell proliferation was observed in the presence of blastocoelic fluids, but not with homologous or heterologous sera. This suppression was higher with samples collected at day 12 than at day 9 of pregnancy. No such inhibition could be detected on one-cell rabbit embryos or on freshly prepared uterine stromal or myometrial cells. In addition, the inhibitory activity on tumor cells was completely reversible upon removal of the fluids. Incorporation of 3H-thymidine, 3H-uridine and 35S-methionine revealed that, in the presence of blastocoelic fluids, both DNA and RNA syntheses were rapidly inhibited. Inhibition of protein synthesis did not occur before 24 hr of treatment. We conclude that rabbit blastocoelic fluid suppresses the proliferation of tumor cells via inhibition of RNA and DNA synthesis by a process which may involve the expression of growth-suppression gene(s).

Animals↗
PubMed1988

Dominantly inherited spastic paraplegia and multifocal palmoplantar hyperkeratosis.

We have extended the study of a previously published kindred with spastic paraplegia and palmoplantar hyperkeratosis from 2 to 18 persons. Present evidence suggests that both neural and cutaneous manifestations are due to a single mutant gene, inherited as an autosomal dominant. Nerve conduction and EMG examination provide evidence for mild lower motor and primary sensory neuron (axon) involvement but these techniques are not useful for early detection. The disorder is a unique genetic disease which stands apart from other mostly recessively inherited varieties of neuroichthyosis.

Adult↗