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Biomedical subjects

C Sauvé

Publications and source records attributed to C Sauvé.

12 recordsLinked to original sources
PubMed2002

Evolution of nematode community in grazing sheep selected for resistance and susceptibility to Teladorsagia circumcincta and Trichostrongylus colubriformis: a 4-year experiment.

Field trials were undertaken to compare nematode population dynamics in two experimental flocks of rams selected for high and for low faecal egg counts (FECs) following two doses with 20000 infective larvae, 12000 Teladorsagia circumcincta (Tcirc) and 8000 Trichostrongylus colubriformis (Tcol) separated by a treatment. The selection was done by dosing 200 ram lambs (INRA 401 breed) and FECs proceeded with egg identification on days 28 and 35 post-each-infection. The 30 lambs with the lowest FECs constituted the group of permanent resistant rams (R), the 30 with the highest values the group of susceptible ones (S). Each group grazed separated pastures from April to November, this during 4 consecutive years. The contamination (number of eggs deposited) was estimated every 3 weeks on each pasture. The larval populations was measured by successive groups of tracer lambs. The infection of the permanent rams was done by slaughtering eight R and S rams on mid and end of each grazing season. Each autumn, new R and S ram lambs were selected to complete the R and S groups before turning out in spring. On third year, a third species (Haemonchus contortus, Hcon) was added to compare its behaviour with the two others. The regulation of parasite populations were studied by comparing what happens in R rams and pasture to S ones. The selected R ram lambs had a FEC of Tcirc 50% lower than S ones. This induced a similar lowered pasture contamination, a 25% decrease of infective larval population in years 2 and 3, and the worm burdens in R rams were the half of that in S rams after 2 years. The FEC of Tcol was 75% lower at the selection and induced similar difference in pasture contamination, but 65 and 96% reduction in L3 population, respectively, after 1 and 2 years. The worm burden was reduced by 99%. Adding Hcon species during the third year, in year 4, the L3 population was half in R pasture compared with S one, and R rams had 60% less worms of this species than S ones. This selection without any drench prevent outbreaks observed in young tracer lambs on S pasture. The comparison of selected resistant rams to selected susceptible ones and not to unselected controls gave more rapid information about the tendency of the regulation of the communities of nematode parasites.

Animal Husbandry↗
PubMed2001

Acute pericarditis with transient constriction.

Transient constrictive pericarditis is a rare entity. It is characterized by clinical and echocardiographic features similar to constrictive pericarditis, but is distinguished by its transient nature. This feature is important to recognize for avoiding unnecessary pericardectomy. The case of a patient who presented with acute myopericarditis and typical echocardiographic features of constriction is described. Within weeks, all signs of constriction disappeared spontaneously.

Acute Disease↗
PubMed2000

Relationship between helminth species diversity, intensity of infection and breeding management in dairy goats.

Helminth infection, species diversity (proportion of each species in the community), species number, intensity of infection and anthelmintic resistance were investigated in 16 dairy-goat farms of south-western France. The aim of the study was to estimate which breeding management factors may affect diversity and intensity of infection. Anthelmintic resistance was investigated because this factor may modify composition of nematode communities. Farm history and breeding management were recorded by means of a questionnaire. Natural and experimental infections were compared to determine which strategy was the best to estimate diversity index and number of species from nematode community of a whole herd. A total of 17 species of helminths, among which 14 nematodes, one cestode (Moniezia spp.) and two trematodes (Paramphistomum daubneyi and Dicrocoelium lanceolatum) were recovered in the 26 necropsied culled goats. One culled goat worm burden represented conveniently species number but not species diversity (Shannon index) of parasite community harboured in the whole herd. Experimental sheep infection with larvae from pooled faeces of 15 goats was the best strategy to estimate species diversity in farms. Diversity could be predicted from the number of farms from which goats originated at constitution of the herd, the duration of goat winter withdrawal from pastures, and intensity of infection. Anthelmintic resistance was correlated with the number of farms of origin, area of permanent pastures and intensity of infection. The strategy adopted for the herd constitution was a critical step as species diversity and risk of anthelmintic resistance increased with the number of farms of origin. Intensity of infection was negatively correlated with species diversity. This suggested that more diverse communities were better controlled by the host, in agreement with the widespread statement that diversity would beget stability.

Abomasum↗
PubMed1999

Segmental myocardial contractility versus perfusion in Kawasaki disease with coronary arterial aneurysm.

The impact of Kawasaki-related coronary injury on the myocardium was evaluated in 13 patients with persistent coronary aneurysm after a follow-up period of 7.92+/-3.97 years (range 1.8 to 14.3). Myocardial segmental perfusion and contractility integrity were assessed by resting and exercise echocardiography and technetium-99 (Tc-99m) sestamibi scan. Eight patients (61.5%) had giant aneurysms (> or = 8 mm) and 9 had multivessel involvement; the mean diameter of the largest aneurysm was 8.6+/-2.5 mm (range 5 to 14). During the acute phase, myocardial infarction occurred in 1 patient and coronary thrombosis in another. At the latest echocardiographic evaluation, the mean aneurysm diameter was 6.8+/-2.4 mm (range 4.5 to 12), there was persistent giant aneurysms in 5 of 8 patients, and 3 of 9 patients had multivessel involvement. Coronary angiography demonstrated stenosis in 7 of 10 patients, with multiple levels in 2. At sestamibi scan, all 13 patients had perfusion anomalies at rest, whereas only 7 had detectable hypokinesia on echocardiography. With exercise, perfusion returned to near normal in 3 patients, improved in 3, remained unchanged in 4, and worsened in 3 patients. Segmental contractility similarly deteriorated in the latter 3 patients but also in 2 patients whose perfusion scan had improved with exercise. Three patients, normal at rest, developed segmental hypokinesia during exercise. When present, the location of observed changes in contractility on stress echocardiography corresponded to that of perfusion defect. In conclusion, abnormal myocardial perfusion is present long term after complicated Kawasaki disease, the worst anomalies accompanying persistent giant aneurysms. Unfavorable perfusion response was coupled with abnormal contractility; however, enhanced perfusion with exercise correlated poorly with segmental contractility response.

Adolescent↗
PubMed1998

Mitral valve repair: Intermediate to long-term echocardiographic follow-up.

OBJECTIVE: To review intermediate to long term echocardiographic follow-up after mitral valve repair for mitral regurgitation. DESIGN: Nonrandomized, retrospective and prospective observational study. SETTING: Sacré-Coeur Hospital, University of Montreal, Montreal, Quebec. PATIENTS: Echocardiographic findings in 37 patients (mean age 62.1 +/- 10 years) three to 197 months (median 45) after mitral valve repair were reviewed. INTERVENTIONS: Preoperative data were collated from hospital records. Between October 1994 and March 1995, all patients had a clinical evaluation and a complete transthoracic echocardiogram done by a cardiologist. RESULT: There was a significant reduction in the dimensions of the left-sided cavities compared with preoperative data. Left atrial diameter decreased from from 50.9 +/- 7.7 to 46.3 +/- 8.1 mm (P = 0.01), left ventricular end-diastolic diameter from 59.6 +/- 7.1 to 51.2 +/- 6.3 mm (P < 0.001) and left ventricular end-systolic diameter from 35.3 +/- 7.9 to 32.8 +/- 7.8 mm (P = 0.07). On colour Doppler echocardiography, nine patients had no mitral regurgitation, 25 had mitral regurgitation grade I to II/IV, and three had grade III/IV. The mean mitral valve gradient was 4.2 +/- 1.8 mmHg and the pressure half-time 121.9 +/- 48 ms. There was no difference in gradient, mitral valve area and mitral regurgitation in patients with degenerative (29) compared with rheumatic (five) mitral valve disease. CONCLUSIONS: Mitral valve repair is highly effective in reducing mitral regurgitation in the long term and is associated with a reduction in the dimensions of the left atrium and the left ventricle. However, it leaves a mild degree of mitral valve obstruction.

Aged↗
PubMed1997

Salmonella endocarditis of a ventricular aneurysm: a case report and review of the literature.

A 63-year-old man with salmonella endocarditis of a ventricular aneurysm is presented. The patient had a documented apical aneurysm with mural thrombus and left ventricular dysfunction following a previous myocardial infarction. His condition was unresponsive to maximal medical therapy and was cured by surgery. A review of the English-language literature revealed that only two other published cases of nonvalvular salmonella endocarditis resulted in patient survival. This report underscores the importance of suspecting a cardiovascular origin in cases of salmonella bacteremia to avoid delay in diagnosis and surgical intervention in this deadly condition.

Aneurysm, Infected↗
PubMed1996

Host, season and year do not play an important role on genetic variability in a trichostrongyle nematode as assessed from allozymes.

The isolates of the trichostrongyle nematode Teladorsagia circumcincta in sheep may vary from one site to another as assessed from allozyme studies. This genetic variability could be host (on the parasitic stages) or/and environmentally (on the free-living stages) induced. In the present study the role of host (susceptible to the establishment of the parasite and partly resistant ones) and environmental changes expressed by season (Autumn versus Spring) or year of sampling (1990 or 1992) were investigated. Five polymorphic enzymes were studied: glucose-phosphate-isomerase (GPI), lactate dehydrogenase (LDH), malate dehydrogenase (MHD), mannose-phosphate isomerase (MPI), and phosphoglucomutase (PGM). No significant difference in allelic frequencies was recorded between 4 susceptible lambs from a flock grazed in 1990 as well as in 3 lambs selected on their susceptibility or resistance to natural infection in a flock grazed in 1992. The mode of infection (natural--frequently repeated small infections, versus experimental--3 repeated large infections) did not modify the allelic frequencies of the nematodes. The allelic frequencies remained stable along the seasons and during the 2 years investigated. The largest distance of Rogers (0.07) and Fst (0.012) were recorded between worms originating from susceptible and resistant lambs or in Autumn versus Spring populations of worms (0.08 and Fst 0.010). A deficiency in heterozygotes of the same magnitude was recorded in the worm populations obtained from the different infections. The stability of allelic frequencies and genetic structure are surprising when one considers the evolution of the same parasite in several generations of laboratory conditions. This stability could be related to the fact that levels of disturbance on parasitic and free-living stages are neither too low (as in laboratory conditions) nor too high (as in farms when anthelmintic treatment are used regularly and destroy the adult stages).

Alleles↗
PubMed1995

Studies on multispecific resistance of gastrointestinal nematodes to benzimidazoles on dairy-goat farms.

Multispecific resistance to benzimidazoles was studied in three selected farms. These farms had bred dairy goats for more than 15 years. The helminths were introduced with the goats at the establishment of the farms which afterwards remained isolated. Nematode resistance could then be related to their own management practices. Faecal egg count tests and egg hatch assays were performed to assess intensity of resistance. The generic (infective larvae in faecal cultures) and specific richness (adult worms) were assessed. The resistant species were Trichostrongylus colubriformis, Teladorsagia circumcincta, Haemonchus contortus and Oesophagostomum venulosum. Faecal egg count reduction tests and egg-hatch assays did not match exactly. Faecal larval counts after treatments gave a distorted picture of multispecific resistance: Haemonchus and Oesophagostomum were very largely over represented. The number of species found in the three farms was relatively low compared with other reports in goat farms of the area. This reduction of diversity might also be due in part to characteristics of breeding management and history (use of permanent pasture and introduction of goats at the establishment of farm).

Animal Husbandry↗
PubMed1983

[Characterization of areas at parasitic risk for sheep reared under conditions of uncontrolled breeding on the ranges of the Causses. 1. Study methodology and its application to gastrointestinal strongyles].

A flock of 50 Lacaune ewes grazed three paddocks (approximately 17ha each) in rotation. Thirteen areas were defined in each of the two selected paddocks on the account of vegetation and spatial utilization by the ewes. These areas represented one tenth of the total area of the paddock. For each area the following measures were estimated: species of grasses, bushes, grass disponibility, amount of faeces deposited, infective larval population of strongyles, duration of the utilization by the ewes for resting or grazing. The measures were achieved during two rotational cycles from May to July 1981. Among the several methods utilized for the assessment of the various parameters influencing the probable infection of animals, one was unsatisfying (estimation of grass intake) and another was of particular good value (estimation of the amount of faeces deposited by an index method). The areas at risk were characterized by a vegetation with Bromus erectus associated either with Festuca duriuscula or Brachypodium pinnatum. The infectivity of each area (number of larvae X duration of grazing) was correlated to the number of strongyle eggs deposited, the amount of faeces accumulated and to an index of pasture quality (pastoral value X biomass of available grass). This work demonstrates that in heterogeneous pasture, even if the level of parasitism (Ostertagia sp. and Nematodirus sp.) is low, area at risk could be determined.

Animal Husbandry↗
PubMed1980

A study of ovine gastro-intestinal strongylosis in a sheep flock on permanent pasture. II. Population dynamics of parasites on the pasture in 1977 and an epidemiological interpretation.

An overall study of gastro-intestinal parasitism was initiated in a flock of sheep in the Western central region of France (Limousin) comprising studies on the animals and on the pasture. Results of the study on animal parasitism and the possibilities of using pepsinogen blood level measurements were published previously (Hubert, Kerboeuf and Gruner, 1979). This report is concerned with the distribution of parasites on the pasture and a discussion on the epidemiology of these strongyles. The pasture was contamined throughout most the year, first by the ewes and then by the lambs from the second month onwards of their presence on the land. Maximum contamination occurred in Summer, but a precocious wave of Ostertagia and Haemonchus larvae on the pasture was responsible for the high incidence of O. circumcincta infections. Unfavourable summer weather depressed the development of eggs and two secondary waves of larvae at the end of August and the end of September brought about peaks of H. contortus and Trichostrongylus in lambs at the end of the summer. Far less Nematodirus were found than normal. In comparison with the weight gain of lambs treated regularly, untreated animals suffered a drop in their rate of growth from the beginning of July to the beginning of September corresponding to the ingestion of a great number of infective larvae. These preliminary results for the year 1977 show the necessity of continuing these observations for several years to enable the effect of preceding year's contamination to be properly assessed.

Animals↗