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Biomedical subjects

H Dumon

Publications and source records attributed to H Dumon.

At least 55 records · Page 3Linked to original sources
PubMed1996

Kinetic aspects of acetate metabolism in healthy humans using [1-13C] acetate.

Acetate metabolism in humans is not well known. Kinetic aspects of acetate were investigated in the postabsorptive state on healthy subjects. In a first study, six subjects were infused with a primed constant infusion of [1-13C]acetate for 3 h and a prime of NaH13CO3. No difference was found between arterialized and venous tracer enrichments from the arm, although arterialized acetate concentrations were higher (74 +/- 12 vs. 59 +/- 14 mumol/l, P < 0.05), suggesting that the hand muscles used but did not produce acetate in the postabsorptive state. Total body flux of acetate was 8.4 +/- 0.6 mumol.kg-1.min-1, of which 69 +/- 5% was oxidized. Acetate contributed to 6.5 +/- 0.4% of the basal energy expenditure. In a second study, five volunteers were submitted to a gastric infusion for 3 h followed by an intravenous infusion of [1-13C]acetate for 3 h. Higher fluxes were observed with the tracer gastric infusion, and the first-pass removal of acetate within the splanchnic bed was 60 +/- 7%. Acetate contributes significantly to the energy supply of the body. It is mainly used by the liver when produced in the gut.

Acetates↗
PubMed1995

Seasonal incidence and ecology of the tick Ixodes ricinus (Acari: Ixodidae) on grazing pastures in western France.

A longitudinal survey was carried out during a 2 year period in Western France to assess the infestation level of grazing pastures by Ixodes ricinus ticks. Four farms were visited once a month and each of the grazing pastures was sampled in the centre and at the border using the blanket dragging method. A total of 3562 I. ricinus (34 adults, 900 nymphs and 2628 larvae) were collected and the infestation was significantly higher during the first year (p < 0.0001). The infestation level by I. ricinus varied between grazing pastures and farms. Grazing pastures in the vicinity of forest were more infested than the others, all through the study. The seasonal distribution of ticks showed peaks, with low fluctuations between farms, years and stages. Tick abundance could not be related to vegetation, but only to the vicinity of woods.

Animals↗
PubMed1995

[Ocular toxoplasmosis: value of immunoblotting for the determination of an intra-ocular synthesis of antibodies].

The aim of this study was to demonstrate the intraocular synthesis of specific antibodies in case of Toxoplasma retinochoroiditis on the basis of immunoblot analysis. Vitreous or aqueous and serum were analyzed by immunoblot in four cases of toxoplasmic chorioretinitis. The same assays were performed on samples from 16 control subjects. Immunoblot analysis of serum and ocular fluid from patients with toxoplasmic chorioretinitis showed IgG and IgA specific antibodies. Recognition patterns were different and demonstrated neo-antibodies in ocular fluid. In control samples only IgG were found and the same patterns were observed in the two compartments. Immunoblot is a useful technique to demonstrate the local synthesis of antibodies in ocular toxoplasmosis by comparison of recognition patterns between serum and ocular fluids. Integration of immunoblot patterns allows quantification of antibodies specific for each Toxoplasma antigen in the two compartments.

Adult↗
PubMed1994

Composition of meal influences changes in postprandial incremental glucose and insulin in healthy dogs.

Postprandial hyperglycemia and insulin secretion depend on many factors, such as food composition, carbohydrate type and processing. The purpose of this study was to evaluate the effects of foods differing in composition in nonobese clinically normal dogs. These dogs were offered in a single meal one of the four foods. Blood samples were collected before feeding and during the 180 min after the meal. Plasma glucose and insulin concentrations were determined. The integrated areas under the postprandial glucose and insulin response curves were calculated. Times to response peaks, maximum plasma insulin elevation, area under the insulin response curve and the insulinemic index differed between dog foods. Crude fiber content had no significant effect. The time to glucose peak was higher and the time to insulin peak lower with the food highest in protein and ether extract content. The time to glucose peak was correlated to protein, fat and nitrogen-free extract content of foods, whereas the time to insulin peak and the area under the insulin curve were correlated to protein and nitrogen-free extract.

Animal Feed↗
PubMed1994

Comparison of PCR with direct examination of bone marrow aspiration, myeloculture, and serology for diagnosis of visceral Leishmaniasis in immunocompromised patients.

A PCR assay amplifying a repeated sequence from the Leishmania infantum genome was compared with direct examination of bone marrow aspirate, myeloculture, and serology for the diagnosis of visceral leishmaniasis in immunocompromised patients. Of 73 patients living in an area endemic for leishmaniasis and where visceral leishmaniasis was suspected by physicians, only 10 had an indisputable diagnosis of visceral leishmaniasis. None of the diagnostic tests performed in the study achieved 100% sensitivity for diagnosing visceral leishmaniasis. PCR exhibited superior sensitivity (82%) in comparison with bone marrow aspirate examination (55%) and myeloculture (55%). Our PCR assay also showed good specificity (97%), negative predictive value (97%), and positive predictive value (82%) even when all unconfirmed PCR results were scored as false positives. Serology exhibited good sensitivity (80%) and excellent specificity (100%), negative predictive value (98%), and positive predictive value (100%) in diagnosing new cases of visceral leishmaniasis but failed to diagnose relapses. We also observed consistent negative serological results using several different immunological detection methods for 2 of the 10 patients with confirmed cases of visceral leishmaniasis. This lack of serological reactivity persisted throughout the course of their infections. These results demonstrate the importance of using PCR as an aid in the diagnosis of visceral leishmaniasis in immunocompromised patients.

AIDS-Related Opportunistic Infections↗
PubMed1993

Isolation and characterization of a repetitive DNA sequence from Leishmania infantum: development of a visceral leishmaniasis polymerase chain reaction.

To construct a DNA probe specific for protozoa that cause visceral leishmaniasis, we cloned Pst I fragments of Leishmania infantum genomic DNA into a Bluescript II SK vector. A clone of 4.3 kb that contained a highly repetitive sequence was isolated and cut with three restriction enzymes: Hae III, Rsa I, and Sau 3A. After a new molecular cloning step, we isolated and sequenced a 140-basepair (bp) fragment. Two oligonucleotides were synthesized to be used as primers for a polymerase chain reaction. Using this probe, we detected an amount of DNA equivalent to one promastigote of L. infantum. This probe showed a high specificity; all protozoa tested that cause visceral leishmaniasis and L. major (one of the causative agents of Old World cutaneous leishmaniasis) showed a 100-bp amplified sequence, whereas other Leishmania strains showed a signal of a different size or else no signal. Moreover, no amplified sequence was obtained with other pathogenic parasites tested (Trypanosoma brucei, T. cruzi, Plasmodium falciparum, Pneumocystis carinii, and Toxoplasma gondii).

Animals↗
PubMed1993

[Contribution of immunoblot to the diagnosis and monitoring of toxoplasmosis in acquired immunodeficiency syndrome].

This study evaluates the potential value of immunoblot for serological survey of toxoplasmosis infection in HIV infected patients. This technique was applied to the detection of IgG, IgM, IgA and IgE antibodies to Toxoplasma gondii in serum and cerebrospinal fluid. We compared the patterns obtained from sera of immunocompetent and HIV+ subjects in different situations: absence of toxoplasmosis, primo-infection, chronic infection and reactivation of toxoplasmosis. IgA antibodies were demonstrated in sera of all HIV+ patients with chronic infection: so, these antibodies have any diagnosis value in this group. IgE were only detected by immunoblot when clinical symptoms of toxoplasmosis occurred in cases of HIV+ patients with reactivation of the parasitosis; previously, these subjects presented a serological rise of IgG specific antibodies. In ten cases of neurotoxoplasmosis immunoblot allowed detection of IgA and IgE antibodies in serum and CSF and demonstrated their intrathecal synthesis in three cases. In conclusion immunoblot is a powerful technique for detection of IgA and IgE to Toxoplasma gondii. Demonstration of IgE antibodies seem to be a good criterion to evaluate the evolutivity of the parasitosis in HIV patients.

AIDS-Related Opportunistic Infections↗
PubMed1992

[Pseudo-tumoral form of urinary bilharziasis in a child].

A tumor-like form of urinary schistosomiasis is reported. Diagnosis was established intraoperatively. The finding of hematuria and of a stay in an area where schistosomiasis is endemic suggested the diagnosis but specific investigations were negative. Cystoscopy revealed a budding, hemorrhagic tumor lying against the posterior aspect of the bladder with no other lesions suggestive of schistosomiasis. The true prevalence of these tumor-like forms of urinary schistosomiasis is analyzed. Emphasis is put on the need for using several investigations to reach the correct diagnosis.

Child↗
PubMed1991

[Extrinsic allergic alveolitis. Apropos of a severe case].

A case of atypical extrinsic allergic alveolitis in a 13-year-old is reported. Onset was sudden with gradually increasing dyspnea on exertion over a four-day period. The chest film evidenced a reticulonodular syndrome with decreased respiratory movements. The patient's clinical status worsened over the next 48 hours with the development of respiratory distress. Under oxygen therapy (3 l/min), PO2 was 49 mmHg and SO2 was 82%. Dramatic improvement occurred after initiation of corticosteroid and antimicrobial therapy. Etiologic investigations were negative except for the immunofluorescence test with pigeon droppings which showed three precipitation arcs. A CT scan of the chest disclosed diffuse micronodular densities without thickening of connective tissue trabeculae, suggesting alveolar disease. Mediastinal lymph nodes were not enlarged. Vital capacity was 26% of the theoric value. Corticosteroids were given for one month. On follow-up chest films, the reticulomicronodular syndrome was seen to abate, globally at first, then from the apices to the bases of the lungs. However, a repeat CT scan at the 4th month showed that diffuse lesions were still present although the chest film was normal; 8 months after onset, there was only a bulla in the left lung base, with no evidence of fibrosis. Lung function tests slowly returned to normal, as did CT scan findings.

Adolescent↗
PubMed1990

[Diagnosis and treatment of hydatid cyst of the liver].

Hydatid cyst of the liver is not uncommon in France. Its various symptoms often include pain, but chance discovery is not exceptional. The diagnosis is helped by two paraclinical examinations, ultrasonography and computerized tomography, which have become indispensable as they provide invaluable information on the precise location and anatomical rapports of the cyst and on possible complications. Laboratory tests are useful for the diagnosis and post-operative follow-up of these cysts. For the time being at least, treatment is purely surgical. Percutaneous needle aspiration and drainage have not yet proved to be totally innocuous, and medicinal treatments seem to be helpful only in cases with intraperitoneal rupture. The choice of the operative technique--essentially a more or less complete cystectomy--has an impact on surgical results: the operative mortality is usually low (2 to 5 p. 100), but the morbidity, mainly due to biliary tract complications of the cysts, remains as high as 30 p. 100.

Echinococcosis, Hepatic↗
PubMed1989

[Aldehydes and ketones in silage: quantitative analysis by high performance liquid chromatography].

Carbonyl compound toxicity is known in several species but no study has been carried out with ruminants. Such volatile compounds exist in silages. After condensation of aldehydes and ketones with 2,4-dinitrophenylhydrazine, quantitative analysis was performed with 37 silages. It was found that quantities of carbonyl compounds varied from 36 mg/kg of dry matter (DM) to 1,535 mg/kg DM with a mean value of 642 mg/kg DM. Ethanal was 63% of the total amount of carbonyl compounds (mol/kg DM). Other molecules were propanal, propanone, butanal (n- and iso-), butanone and n- and iso- pentanal. The total amount of carbonyl compounds correlated positively with the dry matter percentage and negatively with the pH, crude fiber, ash content and volatile fatty acids. Thus, carbonyl compounds seem to be dependent up on silage storage conditions. Lactic flora could be involved in the synthesis of these compounds.

Aldehydes↗
PubMed1988

[A simple method for cloning Leishmania spp].

A rapid and simple technique for isolation of clones of Leishmania spp. was developed. This method consists to adapt promastigote forms of Leishmania infantum to an easily realized medium: the Panmede solid medium. We obtained cloned-population of this parasite for epidemiologic and toxonomic studies.

Animals↗