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Biomedical subjects

M Pépin

Publications and source records attributed to M Pépin.

At least 19 recordsLinked to original sources
PubMed2006

Detection of ovine lentivirus in the cumulus cells, but not in the oocytes or follicular fluid, of naturally infected sheep.

The aim of this study was to examine the Maedi-Visna virus (MVV) infection status of oocytes, cumulus cells, and follicular fluid taken from 140 ewes from breeding flocks. MVV proviral-DNA and MVV RNA were detected using nested-PCR and RT-PCR MVV gene amplification, respectively in the gag gene. Nested-PCR analysis for MVV proviral-DNA was positive in peripheral blood mononuclear cells in 37.1% (52/140) of ewes and in 44.6% (125/280) of ovarian cortex samples. The examination of samples taken from ovarian follicles demonstrated that 8/280 batches of cumulus cells contained MVV proviral-DNA, whereas none of the 280 batches of oocytes taken from the same ovaries and whose cumulus cells has been removed, was found to be PCR positive. This was confirmed by RT-PCR analysis showing no MVV-viral RNA detection in all batches of oocytes without cumulus cells (0/280) and follicular fluid samples taken from the last 88 ovaries (0/88). The purity of the oocyte fraction and the efficacy of cumulus cell removal from oocytes was proved by absence of granulosa cell-specific mRNA in all batches of oocytes lacking the cumulus cells, using RT-PCR. This is the first demonstration that ewe cumulus cells harbor MVV genome and despite being in contact with these infected-cumulus cells, the oocytes and follicular fluid remain free from infection. In addition, the enzymatic and mechanical procedures we used to remove infected-cumulus cells surrounding the oocytes, are effective to generate MVV free-oocytes from MVV-infected ewes.

Animals↗
PubMed2006

Comparison of four diagnostic tests for the identification of serum antibodies in small ruminants infected with Mycoplasma agalactiae.

AIM: To determine the diagnostic capability of a newly developed Western blot (WB) assay for the detection of serum antibodies against Mycoplasma agalactiae compared with conventional serological tests, and to identify the best test for routine diagnostic use. METHODS: The serological test methods used were: two commercial indirect enzyme-linked immunosorbent assays (ELISA), viz ELISA-1, using a bacterial antigen preparation, and ELISA-2, using a recombinant protein (lipoprotein p48) antigen; the complement fixation test (CFT); and a newly developed WB assay, the latter both using a bacterial antigen preparation. Thirty sera from goats infected with M. agalactiae and 97 sera from non-infected sheep were tested using all four methods. RESULTS: Staining patterns in the WB were quite variable. An immuno-dominant band of 41 kDa was detected in 63% of sera from infected animals. The same band also appeared, although mostly very weakly, in 10% of sera from non-infected animals. When suspicious or very weak reactors were omitted, the diagnostic sensitivity (DSE) and diagnostic specificity (DSP), respectively, for the four assays were: WB=56.7%, 97.9%; ELISA-1=76.7%, 99.0%; ELISA-2=56.7%, 100%; and CFT=40.0%, 94.8%. CONCLUSIONS: ELISA-1 performed best in this comparison. While the WB can be used, it did not have a technical advantage over the ELISA. The CFT should be discouraged as the primary screening method for contagious agalactia and should be replaced by ELISA-1. Results from this study confirm that serological test methods for contagious agalactia are useful for the detection of infected flocks but will not detect every individual infected animal.

Animals↗
PubMed2005

Nasal carriage of Staphylococcus aureus in dairy sheep.

The purpose of this study was to assess the prevalence of Staphylococcus aureus nasal carriage of dairy sheep in farms producing cheeses manufactured with raw ewe's milk. The study showed that 29% of ewes carried S. aureus in their nares. The genetic diversity of the 136 isolates recovered from the anterior nares of the ewes, from the ambient air of the milking parlour and from cheeses was investigated using pulsed-field gel electrophoresis (PFGE) of DNA SmaI digests. The genotyping results showed that 75 out of 106 isolates recovered from nasal carriage in dairy sheep belonged to a dominant pattern (previously named OV) and a genetically related pattern (named OV'). The same profile (OV or OV') was found in the ambient air and cheeses, suggesting a continuum between isolates within these different compartments.

Air Microbiology↗
PubMed2004

Detection of a novel border disease virus subgroup in Tunisian sheep.

Nine pestiviruses isolated from different batches of a contaminated Tunisian sheep pox vaccine and one Tunisian field ovine isolate of border disease virus (BDV) were studied at the antigenic and molecular levels. Seroneutralization tests were carried out on three vaccine isolates, the Tunisian field isolate and representative reference strains of the different pestivirus groups. The antigenic study showed that the Tunisian isolates were closer to the two BDV reference strains than to the Alfort-187 and the NADL reference strains. Comparison of the nucleotide sequences of the 5'-non coding regions of all the Tunisian isolates to those of other pestiviruses have shown that these isolates were distinct from the established pestivirus species. The entire N(pro)-E2 coding sequences of four Tunisian isolates were determined and compared to other pestiviruses. Segregation of these pestiviruses based on the N(pro)-E2 region was identical to that obtained with the 5'UTR sequences. The phylogenetic tree obtained with these sequences showed that the Tunisian isolates formed a separate branch between the BDV and CSFV groups, and consequently a possible new species within the pestivirus genus. However, as indicated by the antigenic study and the host origin of the isolates, the Tunisian isolates were assigned to a novel subgroup within the BDV species.

Animals↗
PubMed2003

Genotyping of Staphylococcus aureus isolated from various sites on farms with dairy sheep using pulsed-field gel electrophoresis.

We investigated the genetic diversity of 179 Staphylococcus aureus isolates recovered from various sites in 10 farms producing cheeses manufactured with raw ewe's milk. Isolates were collected from handcrafted cheeses, bulk tank milk, milk from half-udders, skin abscesses on the udder if present, hands and anterior nares of farmers, and air of the milking area. The isolates were typed using pulsed-field gel electrophoresis (PFGE) of DNA SmaI digests and compared to other isolates of S. aureus isolated in different hosts or in different locations. The results showed that nine farms were contaminated by S. aureus isolates with identical banding patterns (named OV) or by genetically related isolates (named OV'). These dominant banding patterns were found in a variable proportion of the samples from each farm (range: 11-100%). Most of the strains isolated from nasal carriage or strains isolated from other regions or from other animal species had different PFGE patterns to OV or OV', except for three strains. These results show that a single clone of S. aureus is widely distributed both in infected mammary glands and in cheese produced from raw milk. This study confirms that infected mammary glands are the main source of the contamination of dairy products in sheep.

Animals↗
PubMed2001

Evaluation of copper availability to plants in copper-contaminated vineyard soils.

The repeated use of copper (Cu) fungicides to control vine downy mildew has led to long-term accumulation of Cu in vineyard soils which now raises the issue of the potential bioavailability of Cu for various living organisms including plant species. The bioavailable Cu can be defined as the portion of soil Cu that can be taken up by roots, for a given plant species. In order to evaluate the bioavailability of Cu to plants, a pot experiment was conducted in glasshouse conditions with a crop species (maize) and 12 soils sampled in the upper horizon of 10 vineyard plots (total Cu ranging from 38 to 251 mg kg-1) and two woodland plots (control soils that had not received any Cu application; total Cu amounting to 20-26 mg kg-1). These soils were selected for their diverse physical (large range of particle size distribution) and chemical (from acid to calcareous soils) properties. After 35 days of growth, plant shoots were harvested for analysis. The roots were separated from soil particles for further analysis. The concentrations of Cu in the roots and aerial parts of the maize were then compared with the amounts of Cu extracted from the soil by a range of conventional extractants. Observed Cu concentrations in maize roots which have grown in contaminated vineyard soils were very high (between 90 and 600 mg kg-1), whereas Cu concentrations in the aerial parts varied only slightly and remained low (< 18 mg kg-1). Root Cu concentrations observed for maize increased with increasing total Cu content in the soil and with decreasing soil CEC. Cu accumulation in maize roots may be as high in calcareous soils as in acid soils, suggesting that soil pH had little influence. In the case of the vineyard soils studied, the lack of correlation found for maize between Cu concentrations in roots and in the aerial parts, suggests that an analysis of the aerial parts would not be a good indicator of plant Cu uptake, as it provides no insight into the real amount of Cu transferred from the soil to the plant. For maize, our results show that extraction with organic complexing agents (EDTA, DTPA) and extraction with ammonium acetate seem to provide a reasonably good estimate of root Cu concentration.

Agriculture↗
PubMed2001

[Psychometric properties of a psychological well-being test for people with physical impairments].

Measuring the psychological well-being of people with physical impairments could provide relevant information to occupational therapists. The aim of this study was to verify psychometric properties of a psychological well-being test called Test de personnalité PER (PER). This test was administered to two samples of people with physical impairments. Two time measurements were collected within a group of 36 individuals and one single measure within another group of 79 individuals. Comparisons between time measurements, between groups and with the normative group of the PER were performed in an attempt to verify the sensitivity, the capacity to discriminate between known groups, and the construct validity of the PER. One section of the Sickness Impact Profile measuring psychological well-being was administered to the same groups to verify the concurrent criterion validity of the PER. The results indicate that the PER has sufficient psychometric qualities.

Persons with Disabilities↗
PubMed2000

Relationship between cognitive capabilities and social participation among people with traumatic brain injury.

This study attempts to determine the relationship between cognitive capabilities and social participation, over a 1-year period, among people who have experienced traumatic brain-injury (TBI). Using the Disability Creation Process as a basis for making hypotheses, three research questions were examined: (1) Do cognitive capabilities improve over time?; (2) Does social participation improve over time?; and (3) Are these two concepts related over time? The results and their clinical implications on rehabilitation are discussed, along with the limitations of this study.

Adolescent↗
PubMed2000

Information-processing speed and assessment of early response latency among stroke patients.

The development of assessment methods for estimating and predicting amount of functional impairment among stroke patients is important for planning rehabilitation. This study explored the contribution of speed of information processing and response latency in the assessment of 39 stroke patients. Functional impairment was assessed among these patients using the Functional Independence Measure, administered within 72 hours of admission to a rehabilitation center. The correlations between the scores on this measure and on a computerized measure of speed of information processing, Cognitive Performance Test, were examined. The Functional Independence Measure can be used with an acute stroke population. Scores are correlated with cognitive indicators of functional impairment, and scores discriminate between severity of functional impairment. These results are discussed with regard to their implication in monitoring stroke patients throughout rehabilitation.

Activities of Daily Living↗
PubMed1998

Salmonella abortusovis, strain Rv6, a new vaccinal vehicle for small ruminants.

Salmonella abortusovis strain Rv6 (Sao Rv6) is a live attenuated vaccine used for a few years to protect ewes against abortive salmonellosis. As Salmonellae, particularly Salmonella aro mutants, have considerable potential as vehicles for the presentation of heterologous vaccine antigens, Sao Rv6 was tested in order to develop a vaccinal vehicle for small ruminants. Five vector plasmids were tested in Sao Rv6; these plasmids, which carry Maltose Binding Protein (MBP) expressed as protein, but differ in their promotors, had been previously tested in S. typhimurium strain SL3261, and were transferred into Sao Rv6. The five plasmids were stable in vitro, and the recombinant Sao Rv6 expressed MBP at various levels. Intraperitoneal infection of OF1 mice with the recombinant bacteria did not modify the characteristics of Sao Rv6; dissemination and infection levels were similar in all groups and all mice developed antibodies to Salmonella antigens as measured by ELISA. In contrast, only animals immunized with Sao Rv6 carrying the pNTE plasmid developed a serum antibody response to MBP. This plasmid was then tested in sheep; following subcutaneous immunization with Sao Rv6-pNTE, dissemination and infection levels were not modified in comparison with sheep immunized with Sao Rv6 lacking plasmid. Antibodies specific to MBP were detected in sera of sheep immunized with Sao Rv6-pNTE, purified MBP, and with S. typhimurium SL3261-pNTE as positive controls. These results demonstrate that Sao Rv6 can be used as a vehicle for heterologous antigens in sheep with pNTE as plasmid vector.

Abortion, Veterinary↗
PubMed1997

Analysis of the immune response in sheep efferent lymph during Salmonella abortusovis infection.

The efferent lymph duct of the ovine prescapular lymph node was cannulated, and Salmonella abortusovis (SAO), a specific pathogen for sheep inducing abortion and mortality of newborn lambs, was inoculated by the subcutaneous route in this lymph node drained area. While the prescapular lymph node draining the inoculation site represented an efficient barrier for the vaccinal SAO Rv6 strain spreading, SAO 15/5 virulent bacteria were steadily detected in efferent lymph of infected sheep. The inoculation of the virulent strain of SAO induced a greater increase of the cell output than did the attenuated vaccinal strain, but proportions of blast cells appearing in the efferent lymph were similar in both cases. Flow cytometry analysis showed that B and T cell outputs were both increased during SAO infections, but while T cell subset proportions slightly decreased, B cell percentages significantly rose, and, at the peak response, almost all of the lymphoblast cells were activated B cells. Typical antibody profiles characteristic of a primary immune response were observed, and antibody titres were greater in the efferent lymph of animals inoculated with the virulent strain of SAO. Many of the cytokine mRNAs we investigated were steadily detected by RT-PCR in efferent lymph cells of control sheep, but frequencies of detection of IL-2, IFN gamma, IL-1 beta and TNF alpha mRNAs were augmented in efferent lymph cells following inoculation of both SAO virulent or vaccinal strains. IL-10 and IL-8 mRNAs could only be detected after a SAO inoculation, while detection of IL-4 mRNAs was increased only in efferent lymph cells from SAO virulent strain-infected sheep. The efferent lymph cannulation technique thus appeared a very powerful way to study the in vivo development of the immune response to SAO, in its natural host, the sheep.

Animals↗
PubMed1997

Analysis of ovine IL-1 beta production in vivo and in vitro by enzyme immunoassay and immunohistochemistry.

A monoclonal antibody (mAb) specific for ovine IL-1 beta was produced and, in conjunction with a polyclonal rabbit antiserum, used to develop a sensitive enzyme immunoassay (EIA) for ovine interleukin 1 beta (IL-1 beta). The mAb neutralised the activity of recombinant ovine IL-1 beta (rOvIL-1 beta) and native OvIL-1 in an ovine thymocyte proliferation assay. However, it did not neutralise the biological activity of rOvIL-1 beta in the murine NOB1/CTLL assay. The mAb did not react with rOvIL-1 alpha, IL-2, IL-4, IL-8, tumor necrosis factor-alpha, gamma-interferon or recombinant human IL-1 beta in indirect EIA. Immunohistological staining of activated alveolar macrophages and frozen lymph node sections sections demonstrated that the mAb detected IL-1 beta secreted by ovine macrophages (CD11c-positive). The EIA was highly sensitive, detecting less than 50 pg ml-1 of rOvIL-1 beta and low levels of native IL-1 beta in supernatants from lipopolysaccharide-stimulated macrophages. The EIA did not detect heat-inactivated IL-1 beta.

Alkaline Phosphatase↗
PubMed1997

Public health hazards from small ruminant meat products in Europe.

Foodborne diseases, in particular those related to meat and meat products, have recently become a matter of great public concern. Sheep and goat meat can transmit infections and diseases either through handling during preparation procedures or as a result of ingestion by the consumer. The authors highlight the second route of contamination in relation to meat and meat products from small ruminants in European countries. Among the most important diseases transmitted by mutton and goat meat, toxoplasmosis remains the greatest threat, particularly in immuno-compromised people and in pregnant women. Other pathogens which may be associated with the consumption of meat from small ruminants include: Clostridium perfringens, Cryptosporidium parvum and Campylobacter jejuni. As with other ruminant species, Escherichia coli O157:H7 can be considered as an emerging pathogen, for which control efforts must be made. The classical zoonoses (brucellosis, Q fever, hydatidosis) are also presented here, although the major source of contamination for these diseases remains contact with infected animals or the handling of carcasses. The fact that the association of foodborne diseases with mutton and goat meat is less frequent than with the meat of other animal species should be noted, for the following reasons: a) lower levels of production; b) less intensive production, leading to a weaker microbial contamination; c) mutton and goat meat are subjected to processing less often than other meats; d) the usual boiling or cooking processes.

Animals↗
PubMed1997

Cytokine gene expression in sheep following experimental infection with various strains of Corynebacterium pseudotuberculosis differing in virulence.

Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis in sheep and goats. This disease is characterized by the development of pyogranulomas in the lymph nodes and lung tissue. To measure the cytokine gene expression in C pseudotuberculosis lesions, sheep were inoculated with two attenuated strains (Tox- and PLD-t) and a wild-type (WT) strain of C pseudotuberculosis and were necropsied at 7 or 28 days post-inoculation. The Tox- strain showed a strong reduction in virulence as assessed by the absence of disseminating lesions in the lymph nodes draining the inoculation site in contrast with the WT strain. The PLD-t strain showed an intermediate reduction in virulence. The two attenuated strains, however, induced the same amount of antibodies and IFN-gamma production as the WT strain. Using a semi-quantitative RT-PCR technique, the expression of inflammatory cytokines was found to be higher in the inoculation site, whereas expression of T-cell associated cytokines was more intense in the draining lymph node. On the whole, the infected sheep produced high levels of cytokines in at least one organ on days 7 or 28 post-inoculation. No significant differences in cytokine gene expression were shown between sheep infected with strains differing in virulence. Higher cytokine expression was measured in sheep with pyogranulomas in the draining lymph nodes as compared to those without, especially for interleukin-1 beta and interleukin-8. Overall, these results taken together confirmed the attenuation of virulence in Tox- and PLD-t strains of C pseudotuberculosis and showed the important role of PLD in disseminating the bacteria from the inoculation site to the draining lymph nodes. The pathogenesis of ovine caseious lymphadenitis was shown to be associated with production of cytokines at the pyogranuloma level, but the local cytokine patterns associated with different courses of infection were not distinguished.

Animals↗
PubMed1996

[Study on insomnia treatment by family physicians].

OBJECTIVES: To describe treatment of insomnia in general practice and to identify family physicians' training needs in this area. DESIGN: Mail survey using Dillman's total design method. PARTICIPANTS: A sampling of 484 general practitioners in the Quebec City area was done to provide roughly equal representation of six practice settings. The response rate was 65%; 295 of the 315 questionnaires returned were selected for analysis. RESULTS: Most physicians reported treating insomnia with general advice and lifestyle changes; 25% reported prescribing hypnotics frequently; 56% reported they prescribed them occasionally. Although 58% often recommend relaxation techniques, only 8% taught these techniques to their patients. Other cognitive and behavioral approaches are rarely used. Most felt that training in treating insomnia should be offered. CONCLUSION: Cognitive and behavioral approaches are very effective approaches are very effective nonpharmacological treatments for insomnia. General practitioners make little use of these treatments that could be easily integrated into clinical practice. Strategies for increasing their use discussed.

Adult↗
PubMed1994

Cellular composition of Corynebacterium pseudotuberculosis pyogranulomas in sheep.

The cellular composition of 46 pyogranulomas experimentally induced with Corynebacterium pseudotuberculosis in sheep was determined by immunohistochemistry. Lesions localized in inoculation sites or draining lymph nodes consisted of macrophage and lymphocyte layers distributed around a necrotic center and surrounded by a fibrous capsule. In immature lesions, T cells of the CD4+ subset predominated, whereas in mature lesions proportions of CD8+ T lymphocytes and cells expressing the gamma/delta chains for the T cell receptor increased. Numerous pyogranuloma cells expressed the interleukin-2 receptor. In addition to these general characteristics, a large individual variability in the proportions of macrophage and T cell subsets was observed for lesions of the same age, in particular for epithelioid macrophages. This heterogeneity suggests a different cellular pattern in relation to the persistence or the elimination of bacteria by the host.

Animals↗
PubMed1994

Comparative histopathology of draining lymph node after infection with virulent or attenuated strains of Salmonella abortusovis in lambs.

Histological responses to the early phase of infection were compared in parotid lymph nodes of lambs infected by the subcutaneous route into the right eyelid with either a virulent or an attenuated strain of Salmonella abortusovis. The right parotid lymph nodes showed a massive PMN infiltration for the first days of infection for both strains. From day 6, the infected lymph nodes developed a lymphoid hyperplasia with prominent germinal centers independent of strain type. The virulent strain of S. abortusovis induced focal lesions in 2 out of 6 lambs necropsied on days 6 and 10, and provoked a systemic infection evidenced by the regular colonization of spleen on day 6. In contrast, no focal lesion and a restricted bacterial dissemination were observed in lambs infected with the vaccinal strain.

Animals↗