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Biomedical subjects

R Porcher

Publications and source records attributed to R Porcher.

At least 19 recordsLinked to original sources
PubMed2007

Misspecified regression model for the subdistribution hazard of a competing risk.

We consider a competing risks setting, when evaluating the prognostic influence of an exposure on a specific cause of failure. Two main regression models are used in such analyses, the Cox cause-specific proportional hazards model and the subdistribution proportional hazards model. They are exemplified in a real data example focusing on relapse-free interval in acute leukaemia patients. We examine the properties of the estimator based on the latter model when the true model is the former. An explicit relationship between subdistribution hazards ratio and cause-specific hazards ratio is derived, assuming a flexible parametric distribution for latent failure times.

Acute Disease↗
PubMed2006

A prospective randomized study to assess the benefit of partial zona pellucida digestion before frozen-thawed embryo transfers.

BACKGROUND: Assisted hatching (AH) in fresh embryo transfer (ET) could be associated with increased implantation rates. However, very few prospective randomized studies have specifically addressed the issue of AH during frozen-thawed embryo transfers (FET) cycles, those that have reported controversial results. The aim of this study was to evaluate the benefit of an enzymatic zona pellucida treatment of frozen-thawed embryos before transfer. METHODS: This was a prospective study including 125 non-donor FET cycles from 125 infertile couples. FETs were randomly allocated into AH group (n = 61, embryos pretreated with pronase 5 IU/ml for 1 min at 37 degrees C) or control group (n = 64, untreated embryos). Zona pellucida thickness was measured for each transferred embryo. The main outcome parameters were clinical pregnancy and implantation rates. RESULTS: The two groups were comparable regarding mean women's age, duration and indications of infertility, IVF outcome after fresh ETs, numbers and quality of fresh and frozen embryos, frozen-thawed embryo survival rates and blastomeres survival indexes. Despite a statistically significant decrease of zona pellucida thickness after pronase treatment [(mean +/- SD) 18.5 +/- 2.25 versus 14.5 +/- 2.75 microm; P < 0.0001], implantation (9.6 versus 9.2%) and clinical pregnancy rates (18.0 versus 17.2%) were not statistically different after FETs, with a similar mean number of embryos transferred between AH and control groups, respectively. CONCLUSION: Within the constraints of our protocol, partial enzymatic digestion of zona pellucida by pronase was not related with any benefit of the FET outcome especially concerning the implantation ability of frozen-thawed embryos.

Adult↗
PubMed2006

[Vaginal mesh extrusion after transvaginal repair of cystocele using a prosthetic mesh: Treatment and functional outcomes].

OBJECTIVE: To describe management of vaginal mesh erosion following transvaginal repair of acystocele by placement of a polypropylene mesh. MATERIALS AND METHOD: Retrospective analysis of 34 consecutive cases of vaginal mesh erosion following transvaginal repair of cystocele using synthetic mesh (Gynemesh or Gynemesh-Soft). We have analyzed the results of both medical and surgical management of this complication. Furthermore, we also assessed sexual and urinary morbidity in women with mesh erosion (n = 34) and in women who had undergone the same procedure but without mesh erosion (n = 111). RESULTS: Among the 34 patients with vaginal mesh erosion, 23 (68%) have undergone local therapy using Colposeptine (Chlorquinaldol + Promestriène). In 12 (52%) cases no modification of the surface of the erosion was observed. In 6 (26%) cases, a decrease of the surface of the mesh erosion was observed. In 5 (22%) cases the mesh erosion had completely disappeared, with a follow-up of 2 to 9 months. Nineteen symptomatic patients (19/32, 59%) required partial (n = 18) or complete (n = 1) excision of the mesh, associated with vaginal mucosal closure, under general anaesthesia. Duration of operation ranged from 15 to 40 minutes for partial excision of the mesh. This procedure was successful in 14 cases (77%). Four women required repeated resection of the mesh because of recurrence. The incidence of de novo dyspareunia was 12% in patients with vaginal mesh erosion, and 11% in patients without mesh erosion (p = 0.81). The incidence of urge urinary symptoms and voiding dysfunction symptoms was respectively 8% versus 9% (p = 0.95), and 8% versus 10% (p = 0.81) in the 2 groups. CONCLUSION: Management of vaginal mesh erosion is simple and is associated with a low rate of morbidity. However, patients should be informed that vaginal erosion of the mesh can occur.

Cystocele↗
PubMed2006

Hyperglycaemia acutely decreases circulating dehydroepiandrosterone levels in healthy men.

OBJECTIVE: This study was conducted in order to evaluate the effect of glucose-insulin homeostasis on adrenal steroids and was designed to separate the effects of hyperglycaemia from those of insulin. DESIGN: Eight healthy men aged 22.6 +/- 3.4 (SD) underwent an 80 mU/m2/min hyperinsulinaemic euglycaemic 100-min clamp, a 200-min graded glucose infusion at 2-16 mg/kg/min and a measurement of fat mass. MEASUREMENTS: Circulating glucose, insulin and adrenal steroid levels including dehydroepiandrosterone (DHEA) were determined before and during both infusion tests. Steroid variations in relation to insulinaemia and glycaemia were analysed using univariate, multivariate tests and nonlinear mixed models. RESULTS: Hyperinsulinaemia induced no significant modification of adrenal steroid levels. By contrast, hyperglycaemia decreased all adrenal steroids except DHEA-sulphate by 47-66%. The drop occurred early, averaging 51% for 17OH pregnenolone and 57% for DHEA at the 80th minute of glucose infusion, whereas blood glucose was 7.1 +/- 1.2 mmol/1. This effect was independent of insulinaemia, fat mass and waist circumference. Thus, we estimated models that could best predict steroid variations according to blood glucose. At thresholds defining impaired fasting glycaemia and diabetes, the estimated decrease in DHEA was 40% and 45%, respectively, culminating at 60% at 9.3 mmol/1 glycaemia, with no detectable further decrease. CONCLUSIONS: Our data suggest that hyperglycaemia dramatically decreases adrenal androgen levels in men, possibly by acting at early steps of synthesis, independently of insulinaemia and fat mass.

17-alpha-Hydroxypregnenolone↗
PubMed2006

Cognitive profile in CADASIL.

BACKGROUND: The spectrum of cognitive alterations associated with CADASIL, a model of pure vascular dementia, has not been thoroughly evaluated. OBJECTIVES: The aims of this study were: (i) to describe the cognitive profile in CADASIL patients according to age; (ii) to compare the profile of patients with dementia with that of patients without dementia; and (iii) to determine the association between alterations in performance in different cognitive domains. METHODS: Forty two consecutive individuals with CADASIL (35-73 years old) were investigated. Cognitive skills were analysed in five domains (executive functions, reasoning, attention, memory, visuospatial abilities) according to age and compared between patients with and without dementia. Associations between cognitive performance and stroke were tested. RESULTS: The youngest patients presented with attention (69%), memory (70%), and executive disturbances (100%). Visuospatial abilities and reasoning deteriorated with age, mainly after the age of 60. About one quarter of patients had dementia, and 75% of these were >60 years of age. Age >60 years was associated with a Rankin score >3 and a significant deficit in all cognitive domains. No association was found between dementia and the number of ischaemic attacks. Episodic memory disorder was characterised by difficulties in retrieval rather than impairment of the encoding process. CONCLUSION: Cognitive decline in CADASIL is dominated by early impairment of executive functions. Skills in other cognitive domains deteriorate with age and are found to be diffusely impaired in patients with dementia. The relative preservation of the encoding process in episodic memory impairment, even in individuals with dementia, is noteworthy.

Adult↗
PubMed2006

Virological, serological and epidemiological study of 255 consecutive cases of genital herpes in a sexually transmitted disease clinic of Paris (France): a prospective study.

Some studies (mostly retrospective) have pointed to an increasing frequency (up to 60%) of herpes simplex virus type 1 (HSV-1) in genital herpes (GH), but they were biased towards severe or atypical cases. We wished to evaluate the frequency of HSV-1 in patients attending our clinic for both first and recurrent episodes of GH. All patients (men and women) with genital lesions compatible with GH were included in a prospective study between May 1999 and April 2002. For all patients a standardized questionnaire, clinical examination, MRC5 culture (Dade Behring), polymerase chain reaction (PCR)-herpes consensus (Argène Biosoft) in case of negative culture and type-specific herpes serology HSV-1 and HSV-2 (Elisa Eurobio) were obtained. Predictive factors associated with HSV-1 and HSV-2 GH were studied by uni- and multivariable analyses. In all, 255 patients had a positive culture (n = 216) or PCR (n = 39). A total of 248 patients had typable herpes (148 men and 100 women). Median age was 33 (27-43); 20% had anal herpes; 48% had clinically recurrent lesions; 21% were HIV +; 20% of men were homosexual; 77% practised oral sex. In all, 36 were HSV-1 (14.5%): more in women, 25/100 (25%), than in men, 11/148 (7.5%) (odds ratio [OR]: 4 [1.8-9.1], P = 0.008). HSV-1 accounted for 23% of cases of first clinical episodes (women: 31.5%; men: 14.7%) (P = 0.02) and 6% of clinically recurrent episodes (women: 15%; men: 1.2%) (OR: 3.8 [1.6-9.1], P = 0.0033). Serological study was done in 239: primary infection was disclosed in 33 (HSV-1: 61%), HSV-2 non-primary first episode in 22 and recurrence in 184 (HSV-1: 8%). In all, 37% of recurrent episodes presented as a first clinical episode. HSV-1 was linked in men with homosexuality (P<0.01) and anilingus (P<0.01), in women with younger age (P<0.01), more sexual intercourses (P<0.0001) and more oral sex (P<0.001). Although HSV-1 is frequent in first clinical (23%) and primary (61%) episodes of GH, recurrent GH remains mostly due to HSV-2 (94%).

Adult↗
PubMed2005

World Health Organization grade 'a' motility and zona-binding test accurately predict IVF outcome for mild male factor and unexplained infertilities.

BACKGROUND: The aim of this study was to determine the pronostic value of a sperm-zona pellucida (ZP) binding assay, combined with World Health Organization (WHO) grade 'a' sperm motility on the day of the IVF attempt, to predict sperm fertilizing ability in unexplained and moderate male factor infertilities. METHODS: In total, 84 couples (64 unexplained infertility; 20 male factor) underwent both a sperm-ZP binding assay and an IVF attempt, irrespective of the test's result. The test was negative when grade 'a' motility was #5% and/or the ZP binding index was <0.7. Fertilization and pregnancy rates were related to the test's results. RESULTS: Thirty-one patients had a negative test (group N) and 53 a positive test (group P). A difference was observed concerning the fertilization rate [median (range): 0 (0-75%) versus 50 (0-100%); P = 0.0001] and the number of cycles with fertilization rate <20% (65 versus 23%; P = 0.0002) between groups N and P respectively. In the group of unexplained and male factor infertilities, the test showed a sensitivity of 83 and 60%, specificity of 50 and 90%, positive predictive value of 76 and 86%, and negative predictive value of 61 and 69% respectively. CONCLUSION: Sperm-ZP binding test, combined with WHO grade 'a' motility assessment, is relevant to prevent IVF fertilization failures in unexplained infertility and, most particularly, in moderate male factor infertility.

Adult↗
PubMed2005

[Recording expulsive forces during childbirth using intercostal muscle electromyogram: a pilot study].

OBJECTIVE: The expulsive forces of childbirth can be included among the many potential risk factors implicated in the subsequent development of perineal disorders. The objective of this study was to devise a non-invasive way to measure abdominal pushing that would accurately represent the expulsive forces during childbirth. PATIENTS AND METHODS: By means of intravesical and intrauterine manometry, and electromyography (EMG) of intercostal muscles, we quantified these forces in 21 women during vaginal delivery. RESULTS: A mixed Ancova model showed the integral of intravesical pressure to be significantly associated (P<0.001) with the integral of intercostal muscle electrical activity during the first 6 uterine contractions during the phase of fetal expulsion. DISCUSSION AND CONCLUSION: Electromyography is a non-invasive measurement that can replace intravesical determinations to quantify these forces as it reflects the real intra-abdominal pressure.

Adult↗
PubMed2005

A note on including time-dependent covariate in regression model for competing risks data.

Recently, regression analysis of the cumulative incidence function has gained interest in competing risks data analysis, through the model proposed by Fine and Gray (JASA 1999; 94: 496-509). In this note, we point out that inclusion of time-dependent covariates in this model can lead to serious bias. We illustrate the problems arising in such a context, using bone marrow transplant data as a working example and numerical simulations. Practical advices are given, preventing the misuse of this model.

Algorithms↗
PubMed2005

Power calculation for the likelihood ratio-test when comparing two dependent intraclass correlation coefficients.

Comparing the reproducibility level of two devices with continuous outcome on a unique sample of subjects (each subject being assessed several times with both devices) comes down to compare two dependent intraclass correlation coefficients (ICCs). When planning such a reproducibility study, one has to specify both the number of subjects to be included and the number of replicates per subject associated to each device. We propose SAS and S-plus macros, which allow power calculations by implementing a simulation study where dependent ICCs are compared by means of a likelihood ratio-test.

Data Interpretation, Statistical↗
PubMed2005

[Setting up a data collection and assessment system of the Permanent Healthcare Access Activities (PASS)].

INTRODUCTION: Five years after introducing the Permanent Access to Healthcare activity (PASS), it became necessary to analyse how it works. MATERIAL AND METHODS: A computerized data collection and assessment system intended to evaluate the PASS health activities has been set up in 11 University Hospitals and ten General Hospitals. From January 1st to June, 30th 2003 data was captured in a computer. RESULTS: The patients requiring medical advice are young (with an average age of 35 years) and present several signs of poverty in terms of accommodation, social relationships and financial means. Besides, almost all of them are uninsured. The PASS public corresponds completely to the created system. Poverty risk factors vary according to the geographic origin. Indeed, French people often suffer from isolation, whereas foreign patients present financial problems. The major part of patients are foreigners and more than a third of them do not speak French, which is an additional obstacle to care. Most of the time, the PASS patients present digestive disorders, nevertheless there are some differences between French and foreign patients. Indeed, foreigners very frequently have digestive and osteoarticluar problems, whereas French patients suffer from psychic disorders and present addictive behaviours. Some patients are sent to physicians downtown (9%) and to external medicosocial assistance centres (39.5%). DISCUSSION: This study (first one in France) provides us with homogenous data regarding the activities of PASS centres nationwide. The usefulness of computers and its acceptability facilitate data diffusion, with possibilities of adapting to each centre while preserving a common basis.

Adult↗
PubMed2005

A meta-analysis of patellar replacement in total knee arthroplasty.

From individual randomized studies it is unclear whether the patella should be replaced during total knee replacement. We did a meta-analysis to provide quantitative data to compare patellar resurfacing with nonresurfacing during total knee arthroplasty. Only randomized, controlled trials reported between January 1966 and August 2003 comparing patellar replacement with patella retention were included for a total of 12 studies. Two reviewers assessed trial quality and extracted data from papers. The outcomes identified were reoperations for patellar problems, anterior knee pain, knee scores, stair climbing, and patient satisfaction. The resurfaced patella performed better, and we found an increased relative risk (defined by the ratio of the risk of the event in the resurfaced group on the risk of the event in the nonresurfaced group) for reoperation, for significant anterior knee pain, and for significant pain during stair climbing when the patella was left unresurfaced. No differences were observed between the two groups for International Knee Society function score, Hospital for Special Surgery score, and for patient satisfaction. Despite these general findings, forming a definitive conclusion is difficult because many confounding factors, such as component design, surgeon experience, and technical aspects of the surgery, might influence the result in a patient.

Activities of Daily Living↗
PubMed2004

Vaginal misoprostol for cervical ripening before operative hysteroscopy in pre-menopausal women: a double-blind, placebo-controlled trial with three dose regimens.

BACKGROUND: To evaluate the effects of vaginal misoprostol on cervical dilatation before operative hysteroscopy in pre-menopausal women. METHODS: Four groups of 12 women were randomly assigned to receive either placebo or vaginal misoprostol in doses of 200, 400 or 800 micro g 4 h before the surgical procedure. The number of patients was calculated with an alpha = 0.01 and beta =0.20 for a difference of 50%. The primary outcome measure was cervical width, assessed by the largest size of Hegar dilator that could be inserted without resistance. The secondary outcomes were subjective assessments of the ease of dilatation and pre-operative pain, as well as adverse effects and complications. RESULTS: There was no difference in the baseline diameter of the cervical opening between the placebo group (6.1 +/- 1.4 cm) and the misoprostol groups (6.3 +/- 2.1 cm). The groups did not differ significantly in the time required for dilatation, ease of dilation, or the number of adverse effects. Pre-operative pain, evaluated by a pain scale, was greater in the treatment groups and was rated at 2.5 +/- 2.3 (P = 0.015), 2.4 +/- 1.2 (P = 0.073) and 2.8 +/- 2.9 (P = 0.012) respectively for each increasing dose group. CONCLUSIONS: Vaginal misoprostol applied 4 h before operative hysteroscopy at three different doses did not reduce the need for cervical dilatation, did not facilitate hysteroscopic surgery, and increased pre-operative pain.

Administration, Intravaginal↗
PubMed2004

Randomized clinical trial to assess the effect of an educational programme designed to improve nurses' assessment and recording of postoperative pain.

BACKGROUND: The aim of this study was to evaluate the impact of an intervention designed to improve postoperative pain assessment and recording by nurses. METHODS: This cluster randomized clinical trial included two intervals of 3 months each: a preintervention observational study (period 1) followed by a period of intervention (period 2). Six surgical wards were randomly assigned to receive either an experimental intervention, including educational seminars for nurses on pain, pain assessment and the use of a visual analogue scale (n = 3), or standard care (control group; n = 3). The main outcome measures were the percentage of patients in whom pain was assessed, number of pain assessments per patient and postoperative pain intensity scores. RESULTS: A total of 2278 patients were included. Significant improvements were found in the percentage of patients in whom pain was assessed and the number of daily pain assessments per patient in the intervention group between periods 1 and 2. In contrast, these outcomes were unchanged between the two intervals in wards randomized to standard care. During period 2, pain scores at 48 h were significantly decreased in the intervention wards compared with those in the control group. CONCLUSION: An educational programme dedicated to nurses strongly increased the use of regular pain assessment, and may have contributed to a modest improvement in postoperative analgesia.

Adolescent↗
PubMed2003

Predictive value of serum thymidine kinase level for Ig-V mutational status in B-CLL.

In B-CLL IgV(H) genes mutational status is a major prognostic factor. Since sequencing of IgV(H) genes is not available in most laboratories, an easily performed surrogate assay is desirable. To identify the best surrogate assay, and to better discriminate prognostic subgroups we analyzed clinical and biological data from 58 typical CLL cases. A higher serum thymidine kinase level (>15 U/l) proved to be a strong predictor of mutational status, and the only independent one among the studied parameters. To further identify prognostic subgroups, cluster analysis was employed on 38 cases on which all data were available, which segregated two groups including 25 and 13 patients, respectively. These two clusters differed by their proliferative potential and appeared to discriminate patients with very different clinical course and outcome. s-TK was strikingly different among these two clusters, suggesting that s-TK level could be used routinely to identify patients at risk of progression.

Aged↗
PubMed2003

Changes in body composition during post-menopausal hormone therapy: a 2 year prospective study.

BACKGROUND: Post-menopausal hormone therapy (pHT) induces changes in both body composition and bone mineral density (BMD). METHODS: In 109 post-menopausal women beginning either tibolone 2.5 mg (n=29), tibolone 1.25 mg (n=42) or estradiol 2 mg plus norethisterone acetate 1 mg (E2 + NETA) (n=38), we assessed body composition, total and regional BMD by dual energy X-ray absorptiometry, and the serum bone alkaline phosphatase (BAP), osteocalcin and the urinary excretion to type I collagen C-telopeptide (CTX) at baseline and after 2 years. RESULTS: At baseline, BMD at all sites correlated negatively with age and years since menopause, and positively with lean mass and fat mass (r=0.42, P<0.001 and r=0.26, P=0.006 at the total femur). During treatment, BMD increased at all sites (P<0.001), and serum BAP, osteocalcin, and urinary CTX decreased in all groups (P<0.001). Lean mass increased whereas android fat and android obesity index decreased. The increase in BMD at all sites correlated positively with changes of lean mass at 2 years. CONCLUSIONS: Both fat mass and lean mass are related to BMD in post-menopausal women, the relationship being strongest with lean mass; an increase in lean mass and a change in distribution of body fat are observed during treatment with E2 + NETA and tibolone.

Adipose Tissue↗
PubMed2003

Hepatitis C virus detection in follicular fluid and culture media from HCV+ women, and viral risk during IVF procedures.

BACKGROUND: Hepatitis C virus (HCV) has been detected in sperm, but no data are available on follicular fluid (FF) collected on IVF procedures. The aim of this study was to: (i) search for HCV RNA in FF and in culture media at each step of IVF undergone by HCV(+) women; (ii) investigate the impact of blood contamination of FF induced by vascular injury associated with transvaginal ovarian puncture; (iii) assess risk for the embryo and the impact on the contamination rate of the newborn; and (iv) determine the viral risk presented by these fluids in order to define guidelines for the laboratory. METHODS: FF from 22 IVF procedures performed in 17 HCV(+) women were classified as either clear, lightly bloody or bloody FF. Oocytes from each FF were washed and incubated in separated fertilization media. At 20 h after puncture (day 1), the fertilized oocytes were washed and transferred to fresh media until embryo transfer. HCV RNA was detected and quantified in FF and media using Cobas Amplicor and Cobas Monitor HCV RNA kits. RESULTS: HCV RNA was positive in 39 of 44 FF samples, and viral loads increased with blood contamination. At day 1, after rinsing of oocyte-cumulus complexes, only 8 of 44 media were still positive. Viral loads were quantified in 5 of 8 positive media, were below the test sensitivity threshold in 4 of 5 HCV RNA-positive media, and just above it in the fifth medium. The day of transfer HCV RNA was undetectable in all media. CONCLUSIONS: HCV RNA was detected in 89% of FF irrespective of the degree of blood contamination, and in 25% of the media at day 1. FF must be considered as potentially infected. Blood contamination increases HCV load in the FF. Rinsing oocytes seems significantly to discard the HCV RNA. It is too early to assess the impact of IVF on the contamination rate of HCV mothers' offspring. After counselling, attempting IVF in HCV(+) women is justified. Universal guidelines prevent nosocomial infection, and IVF does not specifically increase the professional risk.

Adult↗