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Biomedical subjects

D Rey

Publications and source records attributed to D Rey.

At least 37 records · Page 2Linked to original sources
PubMed2001

Efavirenz as a substitute for protease inhibitors in HIV-1-infected patients with undetectable plasma viral load on HAART: a median follow-up of 64 weeks.

We investigated, in a prospective cohort follow-up study, whether substituting efavirenz (EFV) for protease inhibitors (PIs) could be safe in HIV-infected patients with optimal viral suppression achieved on PI-containing regimens. In patients with undetectable plasma viral load (pVL) <50 copies/ml who were naive to therapy with nonnucleoside reverse transcriptase inhibitors (NNRTIs), PIs were replaced by EFV whereas associated nucleoside analogs (NAs) were retained. 62 patients were enrolled. Median follow-up on EFV was 64 weeks (2-88 weeks). Side effects due to EFV occurred in 48 patients. Two patients experienced a high level viral rebound due to diminished compliance; 55 (88.7%) maintained a pVL <50 copies/ml; 3 showed one episode of viremia (52-89 copies/ml); 2 stopped EFV before any VL control. Mean CD4 cell count did not change significantly. One AIDS patient experienced a single cutaneous recurrence of Kaposi's sarcoma after 40 weeks on EFV. Replacing PI with EFV in patients with optimal pVL suppression appears to be safe both virologically and immunologically.

Adult↗
PubMed2001

Mapping of resistance to vegetable polyphenols among Aedes taxa (Diptera, Culicidae) on a molecular phylogeny.

To recover some evolutionary aspects of the interaction between culicine larvae and dietary polyphenols of the vegetation surrounding mosquito breeding sites, we constructed a phylogeny of the most common French Aedes species, chosen as reference species. We also evaluated the differential resistance of these larval taxa to the polyphenols of leaf litter from the riparian vegetation used as a food source. Mitochondrial DNA sequence analysis was performed among 14 different taxa and ecotypes (Aedes aegypti, Ae. albopictus, Ae. cantans, Ae. caspius, Ae. cataphylla, Ae. cinereus, Ae. detritus, Ae. geniculatus, Ae. mariae, Ae. pullatus, Ae. punctor, Ae. rusticus, Ae. sticticus, and Ae. vexans) through direct sequencing of a 763-base segment of the cytochrome oxidase subunit I gene. Phylogenetic analysis, based on nucleotide and amino acid sequences, was conducted by means of parsimony and distance methods. The differential tolerance of larvae to vegetable leaf litter was comparatively tested by use of 10-month-old alder leaf litter as an experimental standard. The absence of correlation between resistance to polyphenols and molecular phylogeny suggests that larval adaptation to polyphenol-rich vegetable breeding sites is a labile character. The acquisition of such resistance appears not to be ancestrally inherited, but rather to be a dynamic adaptation to the environment. Molecular data also support the classical morphological classification within the Aedes genus.

Aedes↗
PubMed2001

[Structured therapeutic interruption in patients infected with HIV-1 experiencing a block in their antiretroviral treatment: preliminary results].

Structured therapeutic interruption (STI) has been offered to HIV-1 infected patients with virological failure (viral load > 1500 copies/mL) of potent antiretroviral therapy (ART) (three or four drugs for at least one year). CD4 lymphocyte count, HIV-1 viral load, clinical status, were assessed every month during STI and after ART reintroduction. Genotype analysis by plasma virus sequencing was done before and after treatment interruption. The results of 14 patients who resumed ART for at least two months are presented. Median duration of STI was 7.5 months (range: 2-13 months). Median CD4 count was low (45/mm3) when treatment was stopped, and decreased during STI (-37/mm3 after six months). Several patients exhibited important CD4 diminutions. Viral load slightly increased (+0.83 log at M6). Few clinical events occurred: one: severe HIV-related prurigo and one CMV viremia. Reversion of resistance mutations was only seen in 2/13 (15: 4%) patients (who had previously a major CD4 deficiency, and a long treatment history), a partial reversion occurred in 5/13 (38.5%) subjects, and the mutations didn't change in the other cases (genotyping non interpretable in the last patient). ART reintroduction induced a good immune response: CD4/mm3 after six months, with significant increases in 10/14 subjects. There was an initial viral response (median viral load: -2.34 log at M1), but a quick rebound most often occurred. However, viral load remained < 50 copies/mL in four patients. In conclusion, a rapid and important decline in CD4 cell count can occur when treatment is discontinued, in patients with virological failure of ART, but the clinical risk appears to be limited. Treatment re-initiation induces a good response, but virologically transient in most cases. Patients with a shift to wild-type virus seem to have a better response.

Adult↗
PubMed2001

Involvement of ligninlike compounds in toxicity of dietary alder leaf litter against mosquito larvae.

The toxicological characteristics of dietary decomposed alder leaf litter against mosquito larvae were further investigated through enzymatic and chemical purification of a phenoliclike cell-wall fraction isolated from crude litter. The toxicity of the subfractions obtained was controlled by standard bioassays on third instars of Aedes aegypti chosen as a reference target species. Enzymatic hydrolyses of the cell-wall fraction were performed with caylase, pectolyase, esterase, and beta-glycosidase, in order to release, respectively, cellulose material and phenolic compounds bound to lignins. These treatments did not affect the larvicidal activity and the phenolic activity of the cell-wall fraction. Chemical alkaline and acid hydrolyses were carried out to break ester and glycosidic bonds of the cell-wall fraction. Comparison of HPLC profiles of the hydrolysates from both toxic and nontoxic fractions did not reveal differences between the phenolic acids released. Aluminum chloride, known for its phenolic complexing activity, counteracted the larvicidal activity of the cell-wall fraction. Altogether, these results suggest the involvement of ligninlike compounds in the toxicity of dietary alder leaf litter against larval mosquitoes. The toxicity of this fraction, which was very sensitive to drastic and smooth oxidations, seemed to be associated with a strong oxidative potential. These results are discussed in relation to a possible mode of action of lignins in the plant-mosquito interactions.

Aedes↗
PubMed2001

Quantitation of hepatitis C virus RNA in saliva and serum of patients coinfected with HCV and human immunodeficiency virus.

The presence and the quantity of hepatitis C virus (HCV) RNA were investigated in saliva and serum of patients infected with both HCV and human immunodeficiency virus (HIV). Paired serum and saliva samples were collected from 59 HIV-HCV coinfected patients. HCV RNA was detected by nested-PCR, using primers derived from the 5' non-coding region of HCV, and positive results were quantified using the b-DNA method. HCV RNA was detected in the saliva of 22/59 (37.3%) patients, with a mean level of 1.15 x 10(6) genome equivalents/ml; there was no correlation of salivary positivity with immune status (CD4 cell count), age or HIV risk group, but there was with gender (19/38 [50%] positive results in male, compared to 3/21 [14.3%] in female, P = 0.007). HCV RNA was detected in the serum of 45/59 (76.3%) patients at a higher level (mean of 2.52 x 10(7) genome equivalents/ml) compared to saliva. Positivity was not correlated with age, gender or CD4 + cell count. There was a correlation between qualitative saliva and serum results (P = 0.003), but not between quantifications (P = 0.57). This first study reporting significant amounts of HCV RNA in saliva could have important implications for HCV epidemiology.

Adult↗
PubMed2000

Increasing the number of hepatitis B vaccine injections augments anti-HBs response rate in HIV-infected patients. Effects on HIV-1 viral load.

Preventing hepatitis B by vaccination is essential in HIV-infected patients (higher progression rate of HBV infection to chronicity, lower rate of serum HBe Ag loss). However, it has been shown a decreased anti-HBs response in these individuals after a standard vaccination (3 doses of 20 micrograms). Thus, we tested the hypothesis that doubling the number of hepatitis B vaccine injections might increase anti-HBs response rate. HIV-infected patients with CD4 > 200/microliter, who were on stable antiretroviral treatment, as well as seronegative for HBV markers, and who have never been vaccinated against HBV, were given 3 intramuscular injections of Genhevac B 20 micrograms at 1 month intervals. Initial non responders were given 3 additional monthly injections. Anti-HBs titer was followed. We also evaluated the effects on HIV-1 viral load. Twenty patients with a median CD4 cell count of 470/microliter were enrolled. The response rate after three 20 micrograms injections was 55% (11/20), lower in individuals with CD4 between 200 and 500/microliter (4/12 = 33.3%), compared to patients with CD4 above 500/microliter (7/8 = 87.5%, P = 0.02). Among 9 initial non-responders, only 2 did not respond to 3 additional doses; thus, the overall response rate was 90% (18/20). Geometric mean titers of anti-HBs were 133 IU/l and 77.5 IU/l, after 3 and 6 Genhevac doses, respectively (P = 0.38). One year later, only 10/17 (58.8%) patients had protective anti-HBs. Five patients experienced a significant viral load increase, transient in 3 cases. These preliminary results suggest that doubling the number of hepatitis B vaccinations in HIV-infected patients might significantly improve anti-HBs response rate; however, close monitoring of anti-HBs is necessary because of its short-lived persistence. The effects on HIV-1 viral load are limited.

Adult↗
PubMed2000

Comparative ability to detoxify alder leaf litter in field larval mosquito collections.

The larvicidal effects of polyphenols from dietary alder leaf litter were investigated in different field collections of three detritivorous Aedes taxa (Ae. detritus, Ae. cataphylla, Ae. rusticus) and compared to the cytochrome P450 monooxygenase, glutathione S-transferase, and esterase activities. Larvae from polyphenol-rich habitats had a higher tolerance for polyphenols and higher midgut cytochrome P450 and esterase activities than larvae from polyphenol-poor habitats. Furthermore, the role of P450 enzymes in the mechanism of resistance to alder polyphenols was suggested by the synergistic effect in vivo of piperonyl butoxide in the resistant Ae. rusticus. This confirms the importance of polyphenols to larval mosquito performance, and provides evidence for the importance of specific detoxification mechanisms for tolerance to dietary polyphenols. Arch.

Aedes↗
PubMed2000

Toxicity of vegetable tannins on crustacea associated with alpine mosquito breeding sites.

The impact of tannins from the environmental vegetation naturally polluting Alpine mosquito breeding sites was experimentally investigated by studying the toxicity of tannic acid, a natural hydrolyzable tannin, on the nontarget crustacean fauna associated with culicine populations. Bioassays indicate that exposure to tannic acid at concentrations from 0.06 to 2.0 mM is more deleterious to Chydorus sphaericus, Diaptomus castor, and Eucypris fuscata, than to Daphnia pulex, Acanthocyclops robustus, and Eucypris virens. Histopathological investigations after treatment with tannic acid at concentrations from 0.125 to 0.500 mM reveal sequential degenerative patterns of the midgut epithelium depending on the taxon, duration of the treatment, and concentrations assayed. These differential toxic effects on Crustacea are compared with those previously observed in larval Diptera, in order to evaluate the plant tannins as potentially useful products in integrated mosquito management programs.

Animals↗
PubMed2000

Differential toxicity of leaf litter to dipteran larvae of mosquito developmental sites.

The relative toxicity of leaf litter to nematocerous dipteran larvae characteristic of mosquito developmental sites was investigated. Culicidae, Chironomidae, and Simuliidae taxa originating from alpine hydrosystems were tested together with two laboratory nonindigenous culicid taxa. Bioassays indicate that ingestion of 10-month-old decaying leaves from Alnus glutinosa, Populus nigra, and Quercus robur by larvae is more deleterious for Aedes aegypti, A. albopictus, Culex pipiens, Simulium variegatum, and Chironomus annularius than for A. rusticus. Histopathological observations reveal that the midgut epithelium is the main target organ of the toxic effect of dietary leaf litter, which appears to be stronger than that of previously reported tannic acid. There is a general response of the nematocerous larval midgut epithelium to dietary tannins-phenolic compounds: clear cells of the anterior midgut showing symptoms of intoxication before dark cells of the posterior midgut.

Animals↗
PubMed2000

High prevalence of GB virus C/hepatitis G virus RNA and antibodies in patients infected with human immunodeficiency virus type 1.

The prevalence of GB virus C (GBV-C)/ hepatitis G virus (HGV) RNA and antibodies to the structural E2 protein was investigated in a cohort of HIV-1 infected patients. Of 346 individuals, RNA was detected in 143 and E2 antibodies were detected in 73, for an overall prevalence of 62.4%. Intravenous drug use and homosexuality were identified as major transmission risk factors. GBV-C/HGV RNA prevalence was associated with hepatitis B coinfection, whereas antibodies to E2 were associated with older age and lower CD4+ cell counts. GBV-C/HGV infection was frequent in this group of HIV-infected patients and was associated with older age, lower CD4 + cell counts, and the presence of hepatitis B surface antigen.

Adenovirus E2 Proteins↗
PubMed2000

Seroprevalence of antibodies to Coxiella burnetti among pregnant women in South Eastern France.

OBJECTIVES: To estimate the seroprevalence of antibodies to Coxiella burnetii among pregnant women and to assess the effect of Q fever on pregnancy outcome. STUDY DESIGN: Anonymous seroprevalence survey between March and May 1996 in all gynecological and obstetrical medical departments of South Eastern France. Women were included irrespective of pregnancy outcome (N=12,716, response rate=96.1%). RESULTS: The seroprevalence rate was 0.15% with a global prevalence and a prevalence of recent or chronic infections, respectively, two and three times higher among women who had a spontaneous abortion than among those who delivered although the differences were not statistically significant. The highest proportion of preterm births (6.8%) was found in high prevalence areas (0.57%). CONCLUSION: The seroprevalence was higher than expected but data were not sufficient to confirm the suspected negative impact of Q fever on pregnancy outcome.

Abortion, Spontaneous↗
PubMed2000

Role of vegetable tannins in habitat selection among mosquito communities from the Alpine hydrosystems.

The role of vegetable tannins in habitat selection among mosquito communities in Alpine hydrosystems was investigated through ecotoxicological comparison of 19 arthropod species characteristic of 12 breeding sites known for their abiotic environmental factors and their different riparian vegetation. The toxicity of tannins was experimentally compared among species representative of both the dipteran fauna and the crustacean fauna associated with the mosquito breeding sites. Bioassays using tannic acid solutions at concentrations from 0.1 to 11 mM separated the dipteran taxa into five groups of differential sensitivity and the crustacean taxa into four groups. The different levels of sensitivity among taxa were correlated with the various amounts of total phenolics and tannins found in the most prominent plant types associated with the different breeding sites. This suggested that tannins and, more generally, phenolic compounds may be involved in plant-arthropod interactions in Alpine hydrosystems.

Animal Feed↗
PubMed2000

Hepatitis C virus co-infection is a negative prognostic factor for clinical evolution in human immunodeficiency virus-positive patients.

A longitudinal study of human immunodeficiency virus (HIV)-infected individuals followed-up in 13 centres was performed to assess the influence of hepatitis C virus (HCV) on the clinical and immunological evolution of HIV-infected patients. Eight-hundred and twelve HIV-infected patients with known HIV acquisition date, 89 co-infected with HCV, were included in the cohort. Clinical progression was defined as: 30% decrease of Karnofsky's index; and/or 20% body weight loss; and/or acquired immune deficiency syndrome (AIDS)-defining illness; and/or death (except by accident, suicide, or overdose). Immunological progression was defined as a decrease of initial CD4 count to below 200 mm(-3). If immunological progression was not statistically different between groups (P=0.25), clinical progression was significantly faster in HCV-HIV co-infected patients in univariate (P=0.02) and multivariable survival analysis (hazard ratio=1.63, P=0.03). This argues for active management of hepatitis C chronic infection among HCV-HIV co-infected patients.

Adult↗
PubMed2000

Post-exposure prophylaxis after occupational and non-occupational exposures to HIV: an overview of the policies implemented in 27 European countries.

The aim of this survey, which was part of an English-French project supported by the Commission of the European Communities, was to compare access to HIV post-exposure prophylaxis (PEP) in the occupational and non-occupational contexts in 27 European countries. A protocol was designed in May 1998 in collaboration with all country consultants. Data were collected at country level by each consultant through interviews, review of local and national recommendations and results of national or local surveys. The final comparative analysis was carried out from the individual country reports and a review of the literature. The large majority of European countries have detailed procedures regarding occupational PEP: 20/27 have produced national guidelines, three have adopted the US CDC recommendations and only four have no official recommendations. Although no standard protocol exists, the more common one is a four-week implementation of a triple combination therapy. In the context of non-occupational exposure to HIV, only five countries have guidelines with specific recommendations and one country has adopted the CDC recommendations. In the majority of cases (13 countries), PEP is never recommended but is only available in a few circumstances, sometimes with major limitations. In the last eight countries, such PEP is not currently available. Although the estimations of HIV transmission risks in occupational and non-occupational contexts are really comparables, easy access to PEP after accidental sexual or blood exposures is not guaranteed for the general population in the majority of European countries.

Anti-HIV Agents↗
PubMed2000

[Emergence of resistant hepatitis B virus strains during long-term lamivudine therapy in human immunodeficiency virus co-infected patients].

Seven patients co-infected with hepatitis B virus (HBsAg and HBeAg carriers, quantifiable HBV DNA with the bDNA technic) and human immunodeficiency virus received a triple antiretroviral combination therapy, including lamivudine (150 mg twice a day). Hepatitis B viral load rapidly became undetectable in 6/7 patients. It remained below the level of detection in 2 subjects, after 20 and 22 months of treatment, with one of them achieving HBeAg/anti-HBe seroconversion. However, in the other 4 individuals, hepatitis B viremia increased again after 8 to 16 months of lamivudine-containing regimen. The last patient was a non-responder. The 4 relapsers developed a double mutation Leu(528) for Met(528) and Met(552) for Val(552), on hepatitis B virus polymerase, either concomitant (M8 and M16) with a hepatitis B virus DNA increase, or 2 months earlier (M10 and M12). The high frequency of hepatitis B virus resistance to lamivudine emphasizes the necessity of identifying more effective strategies, such as double combination therapies.

Adult↗
PubMed1999

High prevalence of GB virus C/hepatitis G virus RNA in patients infected with human immunodeficiency virus.

Prevalence of GBV-C/HGV was determined in a cohort of HIV-infected patients, via a reverse transcription-polymerase chain reaction detection of RNA in serum, amplifying the NS5 region of GBV-C/HGV genome. GBV-C/HGV RNA was detected in 143 (37.7%) of 379 patients, with similar results in the different HIV risk groups: 25/56 (44.6%) in intravenous drug users, 66/161 (41%) in homo- and bisexual men, 35/108 (32.4%) in heterosexual patients, 6/20 (30%) in transfusion recipients (P=0.41). There was no difference according to the presence or absence of hepatitis C virus infection. In univariate analysis, GBV-C/HGV genome prevalence was lower in patients over 50 years old (18.2%), compared to other age groups (20-29 years: 34.2%; 30-39 years: 44.3%; 40-49 years: 36.7%, P=0.03), as well as in patients with normal CD4 cell count (29.2% vs. 45.4% between 200-500/mm3, and 35.3% below 200 CD4/mm3, P=0.012) and individuals with a chronic hepatitis B. However, in the multivariate analysis, the only prognostic factor of GBV-C/HGV RNA positivity was the presence of a chronic hepatitis B, compared to the absence of any HBV marker, or a previous exposition to HBV (presence of anti-HBc and/or anti-HBs, absence of HBsAg), or the presence of anti-HBs alone.

Adult↗
PubMed1999

Histopathological effects of tannic acid on the midgut epithelium of some aquatic Diptera larvae.

The impact of tannins on larval Nematocera was investigated by an extensive survey of the relative toxicity of tannic acid in Diptera larvae representative of mosquito communities from alpine hydrosystems (Culicidae, Chaoboridae, Chironomidae, and Simuliidae) together with a nonindigenous vector competent Culicidae species. Bioassays indicate that exposure to tannic acid at concentrations from 0.25 to 4 mM is deleterious for Culex pipiens, Simulium variegatum, and Chironomus annularius, but not for Aedes, Anopheles, Culiseta, and Chaoborus species. Histopathological observations reveal that, among the target organs of tannic acid, mainly the midgut epithelium is affected by treatment. However, the extent of degeneration varies according to the taxon, the duration of the treatment, and the concentrations assayed. The vulnerability of epithelial cells differs among cell types, clear cells of the anterior midgut showing symptoms of intoxication before dark cells of the posterior midgut. The toxic effects of tannic acid are discussed, particularly in comparison to those of insecticidal bacteria, in order to evaluate the potential for use of tannins in the regulation of larval populations of dipteran pests.

Animals↗