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C Chartier

Publications and source records attributed to C Chartier.

At least 37 records · Page 2Linked to original sources
PubMed2000

Susceptibility of high and low producer dairy goats to single experimental infection with Trichostrongylus colubriformis.

Culled dry dairy goats, which differed in their level of production in previous lactations, received a single infection with Trichostrongylus colubriformis. The objectives of the study were twofold. First, the study aimed at examining the ability of dairy goats to develop an immune response to trichostrongyle infection and the associated cellular changes developing within the intestinal mucosa. Second, a comparison between animals differing in their level of production was assessed, in order to determine whether these differed in their susceptibility to infection. No difference occurred in egg excretion, worm burden and local inflammatory cell responses between high (HP) and low (LP) producer dairy goats, in contrast to observations in previous studies. Because their nutrition was controlled and milk production absent in the goats employed in the present study, these results suggest that any genetic component associated with the selection of HP and LP goats had little influence on the development of acquired resistance to T. colubriformis. The analysis of the relationship between different cell types in the mucosa and some characteristics of the worm population show that eosinophils are negatively related to worm burden. Also, a role is suggested for mast cells and globule leukocytes in the modulation of egg excretion.

Animals↗
PubMed2000

Efficacy of copper oxide needles for the control of nematode parasites in dairy goats.

The spread of benzimidazole-resistant nematodes in dairy goat farms is of a great concern as probably more than 70% of the flocks are involved. As there are very few other anthelmintic options during the lactating period, we have evaluated the efficacy of copper oxide needles (CON, Copinox, Bayer, UK) in both experimental and natural infections in goats. The curative effect of CON (2-4 g) on existing worm burdens was assessed in goats experimentally infected with Teladorsagia circumcincta, Haemonchus contortus and Trichostrongyus colubriformis, compared to controls. The preventive effect of CON (4 g) on worm establishment was monitored for 2 months in animals experimentally infected with H. contortus and for 3 months in naturally infected animals on a farm exhibiting predominant infections with T. circumcincta and Oesophagostomum venulosum. In both experimental and natural conditions, the efficacy of CON was nil against Teladorsagia, Trichostrongylus and Oesophagostomum infections. In contrast, the efficacy of CON against Haemonchus was clearly established in reducing the worm burden (75%) as well as in lowering the egg output (37-95%) in relation to the establishment of new infections over several weeks. Copper oxide needles may represent an alternative to conventional anthelmintics in the control of Haemonchus infection in some goat farms.

Administration, Oral↗
PubMed2000

A questionnaire survey on the practices adopted to control gastrointestinal nematode parasitism in dairy goat farms in France.

To evaluate the efficacy with which recommendations of means to avoid the spread of anthelmintic resistance in parasitic nematode populations are communicated to farmers on dairy goat farms in France, a questionnaire survey was undertaken on their use of antiparasitic drugs. Information was collected from 73 farms in two main areas of dairy goat production. The data referred to three years. Anthelmintics were used in 69 farms, the mean number of treatments per year being 2.74. Changing the drug from one year to another was not practised. Moreover, of the 58 farms using two or more treatments per year, only 37% used anthelmintics from different classes in the lactation and drying-off periods. Benzimidazoles and probenzimidazoles were given in all except two farms and these substances represented more than 80% of all the treatments. Levamisole/pyrantel or avermectins were used in 15% and 27% of the farms, respectively. Double the ovine dose, as recommended in goats to ensure efficacy of benzimidazoles, was applied in 55% of the farms. In addition, in all the flocks, the substances were given on the basis of a mean estimated live weight and not by reference to the heaviest animal. These results indicate that errors in the use of anthelmintics are still frequent in dairy goat farms in France, with probable consequences for the spread of anthelmintic resistance in the populations of parasites.

Animal Husbandry↗
PubMed1999

Some pharmacokinetic parameters of eprinomectin in goats following pour-on administration.

Some pharmacokinetic parameters of eprinomectin were determined in goats following topical application at a dose rate of 0.5 mg/kg. The plasma concentration versus time data for the drug were analysed using a one-compartment model. The maximum plasma concentration of 5.60+/-1.01 ng/ml occurred 2.55 days after administration. The area under the concentration-time curve (AUC) was 72.31+/-1.15 ng day/ml and the mean residence time (MRT) was 9.42+/-0.43 days. Thus, the systemic availability of eprinomectin to goats was significantly lower than that for cows. The low concentration of eprinomectin in the plasma of goats suggests that the pour-on dose of 0.5 mg/kg would be less effective in this species than in cows. Further relevant information about the optimal dosage and residues in the milk of dairy goats is needed before eprinomectin should be used in this species.

Administration, Topical↗
PubMed1998

Response to challenge infection with Haemonchus contortus and Trichostrongylus colubriformis in dairy goats. Consequences on milk production.

The objective of the study was to examine the ability of dairy goats to develop a response to nematode parasites of the digestive tract after a previous contact with the worms. One hundred dairy goats were initially divided into 2 groups. One remained free of parasites (not previously infected: NPI). The second group was infected thrice at 50 days interval with a mixture of Haemonchus contortus and Trichostrongylus colubriformis (previously infected: PI). After this initial exposure to nematodes, the goats were drenched with fenbendazole to eliminate the worms and remained free of parasites for 2 months around kidding. One month after kidding, 24 lactating dairy goats from each initial group were challenged with a mixture of H. contortus and T. colubriformis and parasitological, pathophysiological and milk production parameters were measured fortnightly to assess the effects of challenge infection and the response of the goats. No difference in parasite egg excretion was found between group NPI and PI after challenge infection. Similarly, no difference in worm counts was detected in 5 culled goats from each group killed one month post challenge. In contrast, differences between both groups were detected when considering the pathophysiological parameters (packed cell volume, inorganic phosphate and pepsinogen concentrations) with consequences of infection being more severe in the previously infected animals. Moreover, the milk production was also depressed in the PI group when compared to the NPI one. These results indicate that the response developed by adult dairy goats after the challenge infection was unable to limit the worm populations but could have pathophysiological repercussions and consequences on production.

Analysis of Variance↗
PubMed1998

Repeated infections with Haemonchus contortus and Trichostrongylus colubriformis in dairy goats: comparison of resistant and susceptible animals.

A total of 70 strongyle-free French Alpine dairy goats were exposed to a combination of sequential and challenge infections with Haemonchus contortus and Trichostrongylus colubriformis third-stage larvae. The sequential infection consisted of three inoculations at 50-day intervals, each infection being abbreviated by anthelmintic treatment at 40 days postinoculation. The challenge infection, composed of the same nematode strains, was undertaken 2 months later, when goats were at their 1st month of lactation. Fecal egg counts (FECs), packed cell volumes (PCVs), pepsinogen concentrations, inorganic phosphate concentrations, and peripheral eosinophil numbers were measured at 30-40 days after each inoculation. Goats were defined as being resistant or susceptible according to their level of nematode egg output following the first inoculation. Significant differences in FECs were recorded between the two groups throughout the further inoculations and the challenge infection. The reliability of FECs was supported by the high repeatability values found within and between infections. With regard to blood constituents, only PCVs related to H. contortus infection showed values that differed significantly between the two groups, resistant goats having higher PCVs after the first and the third inoculations than did susceptible animals. However, this difference was not detectable after the challenge infection. The milk production yield for the current lactation was significantly lower in the resistant goats. Moreover, resistant animals exhibited constantly greater body condition scores as compared with susceptible animals. These results indicate that the individual responsiveness of dairy goats to experimental nematode infection can be estimated on the basis of FECs and PCVs (for H. contortus) and is negatively related to the level of milk production of the animals.

Analysis of Variance↗
PubMed1998

Periparturient rise in fecal egg counts associated with prolactin concentration increase in French Alpine dairy goats.

Previous data on periparturient relaxation of immunity during gastrointestinal nematode infection in goats are scarce and conflicting; one study carried out in fiber (Angora) goats showed a positive association of fecal egg counts with prolactin concentrations around parturition, whereas the two other available studies dealing with dairy goats, gave divergent results. The objectives of the study were thus to assess the occurrence of a periparturient rise in fecal egg counts in dairy goats and to examine a possible relationship between the level of milk production and the intensity of the periparturient rise. A total of 28 French Alpine grazing dairy goats naturally infected with Teladorsagia, Trichostrongylus, and Oesophagostomum were allocated into two groups according to their reproductive status; group 1 (n = 7) consisted of nonpregnant lactating animals in the 3rd month of lactation, whereas group 2 (n = 21) was composed of dry goats at 6 weeks before term. Fecal egg counts, pepsinogen and phosphate blood concentrations, blood eosinophil counts, and prolactin concentrations were individually monitored at weekly intervals for 12 weeks (from midwinter to early spring). The mean fecal egg counts were significantly higher in pregnant goats during the 2 weeks before (668 versus 242 eggs per gram of feces (epg), P < 0.05) and the 2 weeks after (962 versus 279 epg, P < 0.01) parturition as compared with nonpregnant lactating animals. No significant difference was seen in the composition of larval cultures between the two groups of animals, with Oesophagostomum infective larvae being found predominantly, particularly at the time of parturition. Pepsinogen and phosphate concentrations as well as blood eosinophil counts were similar between the two groups throughout the survey and indicated a moderate larval challenge. The mean prolactin concentration measured in pregnant goats was significantly higher (P < 0.01) at the time of parturition (298 versus 130 ng ml(-1)) and at 4 weeks after parturition (387 versus 193 ng ml(-1)) than that determined in nonpregnant animals. Furthermore, a significant correlation (rs = 0.30, df = 79; P < 0.01) between fecal egg counts and prolactin concentrations was recorded for the pregnant goats during the 4-weeks period around parturition.

Animals↗
PubMed1998

Determination of eprinomectin in plasma by high-performance liquid chromatography with automated solid phase extraction and fluorescence detection.

A method is described for the determination of eprinomectin in plasma using high-performance liquid chromatography with fluorescence detection (excitation and emission wavelengths 355 and 465 nm, respectively). The fluorescent derivative was obtained by a condensation reaction with trifluoroacetic anhydride and N-methylimidazole. The method employs 1 ml plasma samples and gives linear calibration graphs (r = 0.999) over the concentration range studied (0.5-50 ng ml-1). Solid extraction using the benchmate procedure was used for sample preparation. This method permits the determination of eprinomectin at levels as low as 0.1 ng ml-1 and is suitable for the pharmacokinetic study of eprinomectin in animals.

Animals↗
PubMed1997

Response to challenge infection with Haemonchus contortus and Trichostrongylus colubriformis in dairy goats. Differences between high and low-producers.

The objective of the study was to analyse the influence of the level of milk production in dairy goats on the ability to develop resistance to gastrointestinal nematode infection. Two groups of 50 goats were initially exposed (Group 'Previously Infected' PI) or not exposed (Group 'Not Previously Infected' NPI) to repeated infections with a mixture of Haemonchus contortus and Trichostrongylus colubriformis. After anthelmintic treatment, goats from both groups remained free of parasites for 2 months around kidding. One month after kidding, 24 lactating goats in each group were challenged with Haemonchus contortus and Trichostrongylus colubriformis. Parasitological, pathophysiological and milk production parameters were then examined fortnightly for 3 months following challenge. Within the PI and NPI group, the response to challenge was compared between the 25% goats exhibiting the lowest level of milk production and the 25% with the highest level of production. In the low producers, previous contact with the parasites was associated with a decrease in egg excretion which was not apparent in the high producers. Previous exposure to parasites was also associated with more severe pathophysiological disturbances in the high producers. Lastly, the response to challenge also induced more severe depression in milk production after previous infection in the animals with the highest productive potential. These results confirmed that the level of milk production in dairy goats could influence the resistance and/or resilience to parasitism with more severe consequences detected in the high producers. In addition, the results suggest that such differences could in fact be mainly related to differences in the host response to parasites.

Animals↗
PubMed1997

Species diversity in gastrointestinal nematode communities of dairy goats: species-area and species-climate relationships.

Gastrointestinal nematode communities (12 species) of dairy goats were studied in four regions located in the centre of the western part of France. These regions had very similar annual mean temperatures (11 to 12.5 degrees C) but had rainfall accumulations ranging from 600 to 1330 mm per year. Breeding management (area of pastures, number of goats in the flock, the age of the farm, and the size of the initial goat population) was investigated only in the driest region. The number of helminth species and Shannon diversity index were positively correlated to the permanent pasture area and negatively to the age of the farm. Evenness was negatively correlated to the age of the farm and increased with the increasing levels of rainfall. The results are interpreted in the following terms: i) large areas of permanent pasture include a large array of environments favourable to the development of the free-living stages of various species of nematodes; ii) age of the farm is unfavourable to the maintenance of all introduced species as the farms are helminth-isolated and infestation can only occur during the grazing season thus imposing the necessity of successive annual recolonization of the pastures; and iii) free-living stages are very susceptible to dryness and survive better in areas with heavy rainfall.

Analysis of Variance↗
PubMed1997

[Chronic edema, monoclonal dysglobulinemia and profuse telangiectasia: a distinct entity?].

INTRODUCTION: Monoclonal gammopathy and edema are features encountered during several diseases, especially systemic capillary leak syndrome. The diagnoses of POEMS syndrome, edematous systemic scleroderma and a fortuitous association may be also discussed. We report the cases of two patients which did not fulfill the criteria for such diagnoses. CASE REPORT: Although the 2 cases share some discrepancies, they have also similar and particular features: association of chronic edema, monoclonal gammopathy and profuse and acquired telangiectasias. DISCUSSION: The meaning of these cases remains to be clarified. It might be an entity close to the systemic capillary leak syndrome but characterized by the chronicity of edema and by a distinct cutaneous sign, the occurrence of numerous telangiectasias. These cases emphasize that the acquired and profuse telangiectasias belong to the wide range of cutaneous abnormalities which may be associated with monoclonal paraproteinemia.

Capillary Leak Syndrome↗
PubMed1996

Efficacy of an albendazole slow-release capsule for the control of susceptible or resistant nematode parasites of dairy goats.

The efficacy of albendazole slow release capsules-ASRC- (Proftril-Captec) on gastro-intestinal nematodes of dairy-goats was assessed both for benzimidazole (BZ) susceptible and resistant strains. For BZ susceptible strains, the efficacy of ASRC, assessed by controlled test, ranged from 92% for Trichostrongylus colubriformis to more than 99% for Haemonchus contortus on existing worm burdens. The administration of the ASRC prevented infection with the same strains for 85 to 91 days post treatment. In a dairy goat farm, where both in vitro and in vivo tests indicated a high level of BZ resistance, the efficacy of ASRC on present infections, assessed by Faecal Egg Count Reduction test, ranged from 20 to 60% according to the sampling date (13 to 88 days post treatment). On the same farm the ASRC given at turnout to non infected (primiparous) goats prevented egg shedding up to 72 days (30 for controls). In contrast the ASRC given to infected (multiparous) goats did not prevent egg shedding. The present results show that the ASRC is an efficient device for controlling BZ susceptible nematodes. The ASRC prevents infection with BZ resistant larvae whereas existing infections are not reduced.

Albendazole↗
PubMed1996

Efficient generation of recombinant adenovirus vectors by homologous recombination in Escherichia coli.

Despite recent technical improvements, the construction of recombinant adenovirus vectors remains a time-consuming procedure which requires extensive manipulations of the viral genome in both Escherichia coli and eukaryotic cells. This report describes a novel system based on the cloning and manipulation of the full-length adenovirus genome as a stable plasmid in E. coli, by using the bacterial homologous recombination machinery. The efficiency and flexibility of the method are illustrated by the cloning of the wild-type adenovirus type 5 genome, the insertion of a constitutive promoter upstream from the E3 region, the replacement of the E1 region by an exogenous expression cassette, and the deletion of the E1 region. All recombinant viral DNAS were shown to be fully infectious in permissive cells, and the modified E3 region or the inserted foreign gene was correctly expressed in the infected cells.

Adenoviruses, Human↗
PubMed1996

Targeting cell-specific gene expression with an adenovirus vector containing the lacZ gene under the control of the CFTR promoter.

In vivo gene therapy requires the development of vectors able to deliver and express therapeutic genes preferentially into specific cell populations. This can be achieved by the manipulation of viral proteins mediating target-cell recognition, as well as by the introduction of tissue-specific promoters into viral vectors. As a first approach towards this goal, we describe here the construction and testing of a recombinant adenovirus expressing the lacZ gene encoding beta-galactosidase under the control of 2 kilobase pairs (kbp) of 5' untranslated DNA sequences of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. We show that such a recombinant virus directs beta-galactosidase expression in cell lines expressing CFTR, and in human and murine respiratory tract cells in vitro and in vivo. However, we were unable to demonstrate a cell-type specificity of expression strictly paralleling that of the endogenous CFTR gene. This data indicates that only part of the natural CFTR gene regulation is reconstituted in such a vector.

3T3 Cells↗
PubMed1996

Novel complementation cell lines derived from human lung carcinoma A549 cells support the growth of E1-deleted adenovirus vectors.

Replication-defective E1-deleted adenoviruses are attractive vectors for gene therapy or live vaccines. However, manufacturing methods required for their pharmaceutical development are not optimized. For example, the generation of E1-deleted adenovirus vectors relies on the complementation functions present in 293 cells. However, 293 cells are prone to the generation of replication competent particles as a result of recombination events between the viral DNA and the integrated adenovirus sequences present in the cell line. We report here that human lung A549 cells transformed with constitutive or inducible E1-expression vectors support the replication of E1-deficient adenoviruses. E1A transcription was elevated in most of the cell lines, and E1A proteins were expressed at levels similar to those of 293 cells. However, the levels of expression of E1A did not correlate with the efficiencies of complementation of E1-deleted viruses in A549 clones, since some clones complemented replication in the absence of induction of E1A expression. In addition, complementation of E1-deficient adenoviruses did not require expression of the E1B 55-kDa protein. Although these cell lines contain the coding and cis-acting regulatory sequences of the structural protein IX gene, they are not able to complement viruses in which this gene has been deleted. In contrast to 293 cells, such new complementation cell lines do not contain the left end of the adenoviral genome and thus represent a significant improvement over the currently used 293 cells, in which a single recombination event is sufficient to yield replication competent adenovirus.

Adenovirus E1 Proteins↗
PubMed1995

Efficacy of pyrantel tartrate against experimental infections with Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis in goats.

The efficacy of pyrantel tartrate was evaluated in goats against induced infections with Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis. All the strains were of sheep origin and tested for susceptibility to pyrantel tartrate in sheep at the standard dose rate (20 mg kg-1) prior to the infection of goats. Fifteen French Alpine female goats were inoculated with the three nematode species. On Day 25 post-infection, goats were randomized into an untreated control group and two pyrantel treatment groups (20 mg kg-1 bodyweight once, and 40 mg kg-1 bodyweight as two doses 24 h apart). The goats were killed and processed for worm recovery 10 days after treatment. The two dose rates achieved high and similar levels of efficacy (> 96%) against Haemonchus contortus and Teladorsagia circumcincta. Against Trichostrongylus colubriformis, however, pyrantel tartrate was less effective at both dose rates as worm reductions ranged from 55 to 62%.

Animals↗