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C Clavel

Publications and source records attributed to C Clavel.

At least 19 recordsLinked to original sources
PubMed2006

Identification of type-specific and cross-reactive neutralizing conformational epitopes on the major capsid protein of human papillomavirus type 31.

The majority of the neutralizing epitopes of papillomaviruses (PV) are conformation-specific and have not been fully characterised. Studies have, to date, been limited to a few HPV types only. We analysed the epitopes on the major capsid protein (L1) of Human papillomavirus (HPV) type 31 using monoclonal antibodies (MAbs) generated against HPV-31 virus-like particles (VLPs). The type-specific MAbs against HPV-31 were all found to be neutralizing and recognized conformation-dependent epitopes. Two other MAbs directed against a conformational epitope were found to be cross-reactive with other HPV types, and one of them was found to be cross-neutralizing. Cross-reactive antibodies were further investigated using wild-type HPV-16 L1 VLPs and two mutants. The results obtained suggested the existence of a cross-neutralizing conformational epitope at the N-terminal part of the FG loop of the major capsid protein, and the other four cross-reactive MAbs recognized epitopes also located at the N-terminal part of the FG loop.

Amino Acid Sequence↗
PubMed2006

. Association of HindIII and PvuII genetic polymorphisms of lipoprotein lipase with lipid metabolism and macrovascular events in type 2 diabetic patients.

AIM: Lipoprotein lipase (LPL) is a key enzyme of lipid metabolism, and its genetic polymorphism may be a candidate for modulating lipid parameters in type 2 diabetic subjects (D2). METHODS: In a group of 404 type 2 diabetic patients, aged 59.5+/-10.8y, BMI=28.9+/-5.3 kg/m2, HbA1c=8.2+/-1.9%, we studied the H and P polymorphisms at the LPL locus detectable with the restriction enzymes HindIII and PvuII. Patients were separated into 229 males (17H1H1, 84H1H2, 128H2H2 and 51P1P1, 110P1P2, 68P2P2) and 175 females (16H1H1, 69H1H2, 90H2H2 and 51P1P1, 85P1P2, 39P2P2), and compared on the basis of their lipid parameters and their macrovascular complications. RESULTS: Triglyceride (TG) and HDL-cholesterol(c) concentrations differed between patients with and without coronary heart disease (CHD) (3.44+/-2.09 and 1.96+/-1.40 mmol/l for TGs and 1.05+/-0.24 and 1.34+/-0.40 mmol/l for HDL-c, P<0.001). HDL-c concentrations were lower in male H2H2 and P2P2 subjects (P<0.001), and TG levels were higher in male H2H2 and P2P2 subjects (P<0.0001 for Hind III and P<0.05 for PvuII). Allele frequency of the HindIII and PvuII restriction site was similar to those reported in other Caucasian populations and the presence of the H2/P2 variants was significantly higher in CHD patients. The prevalence of CHD in this population was 18% but was 29% in H2H2 and 38% in P2P2 subjects (P<0.02). CONCLUSION: Thus, HindIII and PvuII polymorphisms seem to exert a modulating role on lipid profile particularly in male D2, contributing to increase the risk of macrovascular events.

Aged↗
PubMed2006

In the rat, citrullinated autologous fibrinogen is immunogenic but the induced autoimmune response is not arthritogenic.

Conversion of arginyl to citrullyl residues (citrullination) is essential for the formation of the epitopes recognized by rheumatoid arthritis (RA)-associated autoantibodies to citrullinated proteins (ACPA). ACPA are secreted by plasma cells of the rheumatoid synovial tissue where their major target, citrullinated fibrin, is abundant. Although numerous arguments suggest that ACPA play an important role in RA, their pathological relevance remains to be established. In the present study, we assessed the immunogenicity and arthritogenicity of complete Freund's adjuvant-emulsified autologous citrullinated (C-rFBG) or non-citrullinated (NC-rFBG) fibrinogen in Lewis (LEW) and Brown-Norway rats, which exhibit drastic differences in their susceptibility to induced autoimmune diseases. NC-rFBG induced no antibody response. In contrast, a single injection of C-rFBG induced an IgG response directed mainly to citrullinated determinants of rFBG. However, all rat strains remained devoid of clinical and histological signs of arthritis up to 3 months after C-rFBG inoculation. Next, in LEW rats, we tested whether autoimmunity to C-rFBG could aggravate acute ankle arthritis triggered by intra-articular injection of incomplete Freund's adjuvant (IFA). However, such arthritis evolved identically in the presence or absence of anti-C-rFBG autoantibodies. However, IFA-injected joints were devoid of citrullinated fibrin deposits. Therefore, citrullination allows breakdown of immunological tolerance but the autoimmune response developed is not spontaneously arthritogenic. Whether or not it can aggravate arthritis with citrullinated fibrin deposits remains to be evaluated.

Animals↗
PubMed2005

IgG subclass distribution of the rheumatoid arthritis-specific autoantibodies to citrullinated fibrin.

In the rheumatoid synovium, deiminated ('citrullinated') forms of fibrin are the major targets of IgG autoantibodies to citrullinated proteins (ACPA), the most specific serological markers of rheumatoid arthritis (RA). To further the characterization of ACPA, we determined their subclass distribution. From a previously validated highly sensitive and specific enzyme-linked immunosorbent assay (ELISA) onto in vitro deiminated human fibrinogen - antihuman fibrin(ogen) autoantibodies (AhFibA)-ELISA - we derived and calibrated four ELISAs, using monoclonal antibodies to each of the four IgG subclasses, to determine the proportions of AhFibA subclasses in the sera. A series of 186 serum samples from RA patients was analysed. All AhFibA-positive sera contained IgG1-AhFibA, which reached the highest titres and accounted for more than 80% of AhFibA in three-quarters of the sera. One or two other subclasses were associated with IgG1 in 39% of the sera, IgG4-AhFibA being observed much more frequently and at higher titres than IgG3- or IgG2-AhFibA. IgG1 alone or IgG(1 + 4)-AhFibA were the AhFibA subclass profiles found in more than 80% of patients. AhFibA are mainly IgG1 and, to a lesser extent, IgG4. Such IgG subclass profiles may influence the effector phases of the immunological conflict between ACPA and deiminated fibrin that takes place specifically in the rheumatoid synovium and therefore may play a critical role in the self-maintenance of rheumatoid inflammation.

Adolescent↗
PubMed2005

Usefulness of HPV testing in the follow-up of untreated cervical low grade lesions.

The aim of the present work was to evaluate the usefulness of high-risk human papillomavirus (HR-HPV) testing for the follow-up of women with untreated low grade cervical squamous cell lesions (LSIL). For that, 412 women with a cytological diagnosis of LSIL at entry were monitored by cytology, HR-HPV testing with the Hybrid Capture II assay (HC-II) and colposcopy. Our primary endpoint was clinical progression defined by the presence of a high grade cervical intraepithelial neoplasia (CIN2 and CIN3) at the biopsy. At baseline, histological control revealed 10 CIN2 and 11 CIN3 only in the cohort of women HR-HPV+. In the follow-up, 4 CIN2 and 8 CIN3 were detected, always in the women initially HR-HPV+. Thus, the recurrence of a HR-HPV+ infection clearly selects a population at high-risk for CIN2-3. The semi-quantitative appreciation of the viral load with HC-II could not be used as a good prognostic factor for the follow-up of women with LSIL. HR-HPV testing reduces the number of cytology and colposcopy examinations in the follow-up of women aged >35 years when HPV testing is initially negative. Thus HR-HPV testing should be reserved for the follow-up of this population of women initially HR-HPV+ and proposed 6 to 12 months after the cytological diagnosis of LSIL.

Adolescent↗
PubMed2004

Negative human papillomavirus testing in normal smears selects a population at low risk for developing high-grade cervical lesions.

High-risk human papillomaviruses (HR-HPV) are the necessary cause of cervical carcinomas and there is an increasing interest in using HR-HPV DNA detection in adjunction to cytological examination for primary cervical screening. To determine whether women with a normal smear negative for HR-HPV DNA detection with the Hybrid Capture II assay might represent a low-risk population for developing a high-grade squamous intraepithelial lesion (HSIL), 4401 women have been followed in a period of 12-72 months (median=34 months). During this follow-up, four HSIL and one microinvasive carcinoma have been detected in this cohort (three in the cohort of 3526 women >29 years). The global negative predictive value (NPV) of double-negative tests is thus of 99.9% (ninety-five percent confidence interval (95% CI): 99.8-100%), whereas cytology alone gives an NPV of 99.2% (95% CI: 98.9-99.5%). If we obtain a second negative HR-HPV test 1-2 years after the initial test, the NPV is 100%. The NPV is also of 100% in the cohort of women >49 years. We conclude that all these women could be safely screened at longer intervals between 3 and 5 years. This policy will offset the increased costs induced by an additional HR-HPV testing in primary screening.

Adolescent↗
PubMed2003

Lichen sclerosus is frequently present in penile squamous cell carcinomas but is not always associated with oncogenic human papillomavirus.

BACKGROUND: Penile squamous cell carcinoma (SCC) may occur on pre-existing lesions of lichen sclerosus (LS). However, the prevalence of histological changes of LS in penile SCC is not well established. Moreover, mucosal oncogenic human papillomaviruses (HPVs) are sometimes detected in penile SCC, but have not been systematically sought in LS-associated penile SCC. OBJECTIVES: To establish the prevalence of LS histological changes and of mucosal oncogenic HPV in a series of patients with penile SCC. METHODS: Consecutive cases of histologically proven penile SCC from a single university hospital over a 14-year period were retrospectively selected and reviewed. Histological signs of LS were systematically sought. HPV was detected by polymerase chain reaction (PCR) amplification of DNA from paraffin-embedded skin samples using general primers GP5+/GP6+ (allowing detection of mucosal HPV) and oncogenic type 16-, 18-, 31- and 33-specific primers. RESULTS: Eighteen cases of penile SCC were found. The mean +/- SD age of patients at diagnosis was 67.3 (14.5 years). In eight of 18 (44%) cases, SCC was associated with histological features of LS. Seventeen skin biopsy specimens of SCC (nine without and eight with LS histology) were subjected to PCR amplification for HPV. Mucosal HPV was detected in six of them (35%). Five of nine SCCs without histological features of LS were positive for mucosal HPV: three with HPV type 16 and two with only general primers. In contrast, all eight SCCs associated with LS were negative for oncogenic HPV types, although one was positive with general primers. CONCLUSIONS: Penile SCC seems to be frequently associated with LS histological changes. As with vulval SCC, we found that non-LS-associated penile SCC tended to be frequently associated with oncogenic HPV infection, whereas LS-associated penile SCC was not. Larger series are needed to confirm this association.

Adult↗
PubMed2001

Quantitative cell dispersion analysis: new test to measure tumor cell aggressiveness.

Tumor progression requires the dispersion of epithelial cells from neoplastic clusters and cell invasion of adjacent stromal connective tissue. Aiming at demonstrating the precise relationships between cell dispersion and cell invasion, related respectively to expression of E-cadherin/catenin complex and matrix metalloproteinases (MMPs), we developed an original in vitro model of cell dispersion analysis. Our study reports the validation of this model that allowed us to analyze and quantify the cell cohesion level by means of time-lapse videomicroscopy and computer analysis based on the observation of spatial and temporal cell distribution. Our model was able to distinguish 2 groups among different human bronchial and mammary epithelial cells previously characterized for the expression of E-cadherin/catenin complex and MMPs and their invasive capacity in the Boyden chamber assay. The first group (16HBE14o(-), MCF-7, T47D) that expressed membranous E-cadherin and beta-catenin, and was negative for MMP-2 expression and non-invasive, displayed a highly cohesive pattern corresponding to a cluster spatial distribution. The second group (Beas2B, BZR, BZR-T33, MDA-MB-231, MDA-MB-435, BT549 and HS578T) that was invasive and showed lack of expression of E-cadherin and a cytoplasmic redistribution of beta-catenin, displayed a dispersed pattern corresponding to a random spatial distribution. Downregulation of E-cadherin by a blocking antibody induced a more random distribution. Conversely, expression of E-cadherin by cDNA transfection induced a cluster distribution. Moreover, tumor cell lines that co-expressed MT1-MMP and MMP-2 (Beas2B, BZR, BZR-T33, MDA-MB-435, BT549 and HS578T) showed a more dispersed pattern than tumor cell lines that did not express MMP-2 (MDA-MB-231). In conclusion, we demonstrated that the spatial group behavior of cell lines, i.e., their cohesion/dispersion ability, reflects their invasive properties. Thus, this model of cell dispersion analysis may represent a new test to measure tumor cell aggressiveness.

Breast↗
PubMed2001

Human papillomavirus testing in primary screening for the detection of high-grade cervical lesions: a study of 7932 women.

High-risk human papillomaviruses (HR-HPV) are the necessary cause of cervical carcinomas. To determine whether HPR-HPV DNA detection in primary routine screening could represent a sensitive and reliable technique for the detection of high-grade squamous intraepithelial lesions (HGSIL), laboratory analysis using 2 cytologic techniques (conventional and liquid-based), HPV testing with Hybrid Capture II assay (HC-II), followed by colposcopic examination of women with abnormal cervical finding and/or persistent HR-HPV infection, was conducted in 7932 women who had routine cervical examination. The sensitivity of HPV testing for detecting a histologically proven HGSIL was 100%, higher than that of conventional (68.1%) and liquid-based (87.8%) cytology. The low specificities of 85.6% and 87.3% of HPV testing slightly increased to 88.4% and 90.1% if HPV testing was reserved for woman >30 years old. The quantitative approach provided by the HC-II assay for the assessment of the viral load was not reliable for predicting HGSIL in normal smears. HR-HPV testing could be proposed in primary screening in association with cytology. With conventional cytology it significantly improves the detection of HGSIL. With the use of the same cervical scrape for HPV testing and liquid-based cytology, HR-HPV testing would allow to select positive samples treated in a second time for cytology which gives a good specificity.

Adolescent↗
PubMed2001

Human papillomavirus infection and anogenital condyloma in bone marrow transplant recipients.

BACKGROUND: Secondary malignant diseases are late complications after allogeneic bone marrow transplantation (BMT). Anogenital lesions associated with human papillomavirus (HPV) infection have been described in renal transplant recipients but not after BMT. HPV types 16 and 18 are strongly linked to the malignant transformation. METHODS: In a series of 238 patients with allogeneic BMT, three had anogenital lesions. We looked for HPV in DNA extracted from embedded tissue to study HPV genotypes, p53 expression, and ploidy. RESULTS: In two patients, HPV sequences were detected. One of them, with giant condyloma, had HPV type 18 and two aneuploid clones, but p53 expression was not found. CONCLUSION: As in solid organ transplant recipients, anogenital condyloma may develop after BMT. Because the oncoprotein of HPV is able to bind and to degrade p53, it may lead to genetic instability, and subsequently to malignant transformation.

Adult↗
PubMed2001

DNA image cytometry and human papillomavirus (HPV) detection help to select smears at high risk of high-grade cervical lesions.

Three samples were submitted from women undergoing routine screening (n=910): two smears (one for routine cytology and one for DNA image cytometry) and a scrape for human papillomavirus (HPV) testing. DNA histograms were classified as suspect in cases of aneuploidy, polyploidy, and/or diploidy with a high proliferation rate. Follow-up was available in 239 cases. The primary end-point was the presence of a high-grade squamous intraepithelial lesion (HGSIL) at biopsy. Seventy women (7.7%) had a high-risk (HR) HPV infection and a suspect DNA profile. In 77 women with cytological abnormalities, 28 HGSILs were detected: four with a prior diagnosis of ASCUS (all HR-HPV infected including three with a suspect DNA profile), three with smears evocative of LGSIL (all with HR-HPV infection and a suspect DNA profile), and 21 with smears evocative of HGSIL (all with HR-HPV infection and 20 with a suspect DNA profile). During the follow-up period, out of 239 women with a cytologically normal smear at first entry, five developed a HGSIL; all were HR-HPV-positive and four had a suspect DNA profile at the first smear. HR-HPV detection alone gives a sensitivity of 100% for the detection of HGSIL, with a specificity of 84.3%, whereas DNA measurement associated with HPV testing significantly enhances the specificity to 95.4%. Thus, the combination of HPV testing and DNA measurement provides a highly sensitive and specific evaluation of the risk of HGSIL on cervical smears.

Cervix Uteri↗
PubMed2000

Spectrum of CFTR mutations in cystic fibrosis and in congenital absence of the vas deferens in France.

We have collated the results of cystic fibrosis (CF) mutation analysis conducted in 19 laboratories in France. We have analyzed 7, 420 CF alleles, demonstrating a total of 310 different mutations including 24 not reported previously, accounting for 93.56% of CF genes. The most common were F508del (67.18%; range 61-80), G542X (2.86%; range 1-6.7%), N1303K (2.10%; range 0.75-4.6%), and 1717-1G>A (1.31%; range 0-2.8%). Only 11 mutations had relative frequencies >0. 4%, 140 mutations were found on a small number of CF alleles (from 29 to two), and 154 were unique. These data show a clear geographical and/or ethnic variation in the distribution of the most common CF mutations. This spectrum of CF mutations, the largest ever reported in one country, has generated 481 different genotypes. We also investigated a cohort of 800 French men with congenital bilateral absence of the vas deferens (CBAVD) and identified a total of 137 different CFTR mutations. Screening for the most common CF defects in addition to assessment for IVS8-5T allowed us to detect two mutations in 47.63% and one in 24.63% of CBAVD patients. In a subset of 327 CBAVD men who were more extensively investigated through the scanning of coding/flanking sequences, 516 of 654 (78. 90%) alleles were identified, with 15.90% and 70.95% of patients carrying one or two mutations, respectively, and only 13.15% without any detectable CFTR abnormality. The distribution of genotypes, classified according to the expected effect of their mutations on CFTR protein, clearly differed between both populations. CF patients had two severe mutations (87.77%) or one severe and one mild/variable mutation (11.33%), whereas CBAVD men had either a severe and a mild/variable (87.89%) or two mild/variable (11.57%) mutations.

Adult↗
PubMed2000

[Human papillomavirus typing in routine cervical smears. Results from a series of 3778 patients].

AIM: As human papillomavirus (HPV) infection is a significant risk factor for cervical cancer, the aim of this study was to assess the efficacy of HPV detection techniques in predicting the presence or the development of a high-grade squamous intra epithelial lesion. Additional reasons for carrying out this investigation were as follows. It was considered that the clinical value of HPV typing may have been underestimated in certain previous reports, which based their findings on first-generation assays. Moreover, until the present investigation most studies only investigated the cases with abnormal smear findings and did not include long-term follow-up, nor detailed follow-up of women with a normal smear but positive HPV typing, although this patient subgroup is of particular interest. The patient population included 3778 women who underwent routine cytological cervical screening and who gave their informed consent to participate in this study, consisting of a cervical smear, HPV testing via a second-generation Hybrid Capture II assay (which is more sensitive than first-generation tests, and can detect 18 different HPV types, i.e., 13 oncogenic and five non-oncogenic types); and in the case of abnormal smear findings, colposcopic examination and directed biopsies of the sites of suspected lesions. The women with cytomorphologically normal cervical smears but which who HPV-positive were reexamined six months later. RESULTS: HPV findings were positive in 66 cases where the initial smear indicated the presence of a high-grade lesion with the diagnosis confirmed by biopsy in 65 cases; in 155 cases (76.1%) where the initial smear indicated the presence of a low-grade lesion; in 44 (57.1%) out of 77 smears indicating the presence of ASCUS-type (atypical squamous cells of undetermined significance) lesions; and in 366 cases (10.5%) of apparently normal initial smears. After colposcopy and follow-up, a final diagnosis of high-grade lesion was made for 85 patients. All these patients were found to have high-risk (oncogene-positive) HPV at the first examination, but in only 65 cases (76.5%) was the initial smear indicative of a high-grade lesion. Finally, in the patient groups with low-grade or ASCUS-type smear findings or with an apparently normal smear, a high-grade lesion was only found in those patients with persistent high-risk HPV infection. In all, the sensitivity of the Hybrid Capture II assay in detecting high-grade lesions was 100% versus 85.9% for standard cytology. However, its specificity (86.3%) and positive predictive value were not as high as the latter. CONCLUSION: The results of this study indicate that HPV typing via this second-generation assay displays good sensitivity for the detection of at-risk cases, i.e., those involving the presence or development of high-grade cervical lesions. However, a number of issues have to be addressed before HPV typing is adopted in clinical practice, such as the fairly high HPV prevalence in women aged over 60 years, and whether the implications of this are the same as for younger age groups. Also, the present cost of complete typing remains too high for it to be used on a widespread scale. Nevertheless, HPV typing may have a useful role to play in the detection of cervical cancer.

Adult↗
PubMed2000

Human papillomavirus detection by the hybrid capture II assay: a reliable test to select women with normal cervical smears at risk for developing cervical lesions.

The reliability of the Hybrid Capture II (HC-II; Digene, Silver Spring, MD, U.S.A.) assay was tested in detecting 18 human Papillomavirus (HPV) types for the screening of cervical lesions. Cytology, HPV testing, colposcopy, and biopsy were used to monitor 204 women with normal smears at the first entry. The median follow-up was 15 months (range, 4-27 months). The primary endpoint was clinical progression defined as the presence of a cervical intraepithelial lesion at the biopsy. In the patient population of 204 HPV-infected women, 81 (39.7%) had a persistent HPV infection at two or three examinations with a final histologic diagnosis of 14 high-grade and 13 low-grade squamous intraepithelial lesions (SIL) within 4 to 22 months. Women with regressive HPV infection did not develop any lesion during the same period. The evaluation of the viral load of high-risk HPV by the HC-II did not represent a sensitive approach to predict the persistence or the apparition of high-grade lesions. Thus, persistent high-risk HPV infection detected with HC-II represents a reliable tool to select populations at risk for the development of high-grade cervical lesions.

Adolescent↗
PubMed2000

Human papillomaviruses and DNA ploidy in anal condylomata acuminata.

Previous studies have emphasized the usefulness of DNA ploidy measurement and Human Papillomavirus (HPV) detection as prognostic markers in low grade cervical lesions. We addressed the eventual relationship between HPV type, DNA profile, and p53 tumor suppressor protein expression in anal condylomata acuminata to eventually determine parameters which may be considered as predictive risk factors for the development of cancer. DNA ploidy was assessed by image cytometry after Feulgen staining of contiguous serial sections of 45 anal condylomata acuminata without atypia containing HPV detected by in situ hybridization and Polymerase Chain Reaction (PCR). p53 expression was detected by immunohistochemistry. DNA aneuploidy was found in 53.3% of these lesions, 48.9% containing non oncogenic HPV types 6 and/or 11 and 4.4% harbouring HPV types 11 and 18. The DNA diploid lesions were all associated with non oncogenic HPV types 6 and/or 11 and one case also contained HPV type 33. There was no significant correlation between the detection of DNA aneuploidy and the presence of immuno-detected p53. DNA aneuploidy was not related to the presence of oncogenic HPV in anal condylomata acuminata. The DNA aneuploid profile frequently observed, especially in lesions associated with non oncogenic HPV types, is not yet well explained and cannot be considered as a prognostic factor. In contrast, a more intensive clinical follow-up should be proposed in patients with oncogenic HPV associated to DNA aneuploidy.

Adult↗