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Biomedical subjects

C Laurent

Publications and source records attributed to C Laurent.

At least 73 records · Page 4Linked to original sources

DiHA (dextranomers in hyaluronan) injections for treatment of insufficient closure of the vocal folds: early clinical experiences.

OBJECTIVE: To determine the clinical effects of injecting DiHA (a mixture of dextranomer molecules and 1% hyaluronan solution in equal proportions) as a "space filler" into the vocal folds of patients experiencing insufficient closure of the vocal folds resulting from either unilateral vocal fold paralysis or bowed vocal folds. STUDY DESIGN: A consecutive series of patients with insufficient closure of the vocal folds treated with DiHA injections and prospectively followed up with videostroboscopy and voice recordings that were evaluated by expert panels. METHODS: During a 21/2-year period, 14 patients with insufficient closure of the vocal folds were included. Six had a unilateral vocal fold palsy and 8 patients had "bowed" vocal folds. DiHA was injected into one vocal fold. Laryngoscopic examination and voice recordings were performed pre- and postoperatively. Expert panels did the evaluation of the stroboscopy examination and the perceptual voice analysis. RESULTS: Three patients were operated on with local and 11 under general anesthesia. All patients with unilateral palsy improved their stroboscopic status regarding both the wave and the closure after injection. Also, their voice parameters were significantly improved. Among the patients with bowed vocal folds, all except 2 showed an improvement in the glottic wave, 5 of 8 improved in glottic closure, and 3 improved their voice parameters significantly. CONCLUSION: This early clinical experience indicates that DiHA fulfills most of the requirements of an ideal "space-filling" substance for voice restoration in patients experiencing insufficient vocal fold closure.

Adult↗

[Benign hepatic tumors: diagnostic management and therapeutic outcome].

The number of non-malignant tumors of the liver diagnosis has greatly increased with widespread use of abdominal ultrasonography. Unlike hemangioma and focal nodular hyperplasia does not require surgery as does hepatocellular adenoma due to the risk of fatal complications. Differentiation between these three kinds of benign tumors is of prime importance to avoid unnecessary surgical interventions. Progress in medical imaging facilitates identification of hemangioma and focal nodular hyperplasia, but in case of doubt, histological proof must be obtained. Laparoscopy may be indicated not only for diagnostic but also for therapeutic purposes.

Humans↗

Multicenter linkage study of schizophrenia candidate regions on chromosomes 5q, 6q, 10p, and 13q: schizophrenia linkage collaborative group III.

Schizophrenia candidate regions 33-51 cM in length on chromosomes 5q, 6q, 10p, and 13q were investigated for genetic linkage with mapped markers with an average spacing of 5.64 cM. We studied 734 informative multiplex pedigrees (824 independent affected sibling pairs [ASPs], or 1,003 ASPs when all possible pairs are counted), which were collected in eight centers. Cases with diagnoses of schizophrenia or schizoaffective disorder (DSM-IIIR criteria) were considered affected (n=1,937). Data were analyzed with multipoint methods, including nonparametric linkage (NPL), ASP analysis using the possible-triangle method, and logistic-regression analysis of identity-by-descent (IBD) sharing in ASPs with sample as a covariate, in a test for intersample heterogeneity and for linkage with allowance for intersample heterogeneity. The data most supportive for linkage to schizophrenia were from chromosome 6q; logistic-regression analysis of linkage allowing for intersample heterogeneity produced an empirical P value <.0002 with, or P=.0004 without, inclusion of the sample that produced the first positive report in this region; the maximum NPL score in this region was 2.47 (P=.0046), the maximum LOD score (MLS) from ASP analysis was 3.10 (empirical P=.0036), and there was significant evidence for intersample heterogeneity (empirical P=.0038). More-modest support for linkage was observed for chromosome 10p, with logistic-regression analysis of linkage producing an empirical P=. 045 and with significant evidence for intersample heterogeneity (empirical P=.0096).

Chromosome Mapping↗

HPV oncoprotein E6 is a structure-dependent DNA-binding protein that recognizes four-way junctions.

E6 is an oncoprotein implicated in cervical cancers, produced by "high-risk" human papillomaviruses. E6 is thought to promote tumorigenesis by stimulating cellular degradation of the tumour suppressor p53, but it might display other activities. Sequence similarity was recently detected between E6 and endonuclease VII, a protein of phage T4 that recognizes and cleaves four-way DNA junctions. Here, we purified recombinant E6 proteins and demonstrated that high-risk E6 s bind selectively to four-way junctions in a structure-dependent manner. Several residues in the C-terminal zinc-binding domain, the region of E6 similar to endonuclease VII, are necessary for the junction-binding activity. E6 binds to the junction as a monomer. Comparative electrophoresis shows that E6-bound junctions migrate in an extended square conformation. Magnesium inhibits the electrophoretic migration of the complexes but does not seem to influence their formation at equilibrium. This work is the first demonstration of specific binding of purified active E6 to a well-characterized DNA ligand, and suggests new modes of action of E6 in oncogenesis.

Amino Acid Sequence↗

Dichlorvos and carcinogenicity: a systematic approach to a regulatory decision.

On the request of the Belgian Health Council, the authors performed a systematic review of the available evidence in the literature and in expert panel reports, with regard to a possible carcinogenic effect of dichlorvos. Following the evaluation procedure developed by IARC, they first concluded that dichlorvos should be classified as a possible carcinogen for man. This preliminary conclusion, and its possible consequences of withdrawal of several product authorizations, was then communicated by the Health Council to all stakeholders. As a result, the interpretation of the animal experimental data was confronted with the conclusions of a U.S. "Blue Ribbon Panel" of independent experts, who reviewed all the data that were available to them. After an exchange of views, the Health Council downgraded its classification of dichlorvos toward nonclassifiable with regard to cancer in man. This paper describes the review and decision-making processes, focusing on the major arguments underlying the original interpretation of the animal data and its eventual modification.

Carcinogens↗

[Conservative treatment of adenocarcinomas of the anorectal junction by preoperative radiotherapy and intersphincteral resection].

AIM: Adenocarcinomas of the anorectal junction, especially T3 lesions, are usually treated by abdominoperineal resection. The aim of this study was to evaluate oncologic and functional results following conservative radiosurgical treatment of cancers of the anorectal junction. METHODS: From 1990 to 1999, among 395 patients with rectal carcinoma, 31 had sphincter-saving resection for a tumour located between 2 to 4.5 cm (mean 3.6) from the anal verge. There were 16 men and 15 women, mean age 62 years (range 30-86). There were 5 T2, 23 T3 and 3 T4 tumours; 17 were N1 and 3 were M1. Preoperative radiotherapy was performed in 26 patients (dose: 46 Gy, range: 36-54), with concomitant chemotherapy in 14 cases. Intersphincteric resection was performed six weeks after neoadjuvant treatment. Coloanal anastomoses were associated with a colonic pouch in 22 cases and with a protecting stoma in all cases. RESULTS: There was no postoperative mortality. Seven complications occurred: 3 anastomotic fistulas, 3 pelvic haemorrhages and 1 acute pancreatitis. Three patients had a definitive stoma. After preoperative radiotherapy, down-staging (pT0-2 N0) occurred in 46% of cases (12/26). Distal margin was 2.2 cm (range: 1-3) and was microscopically safe in all cases. Lateral margin was safe (> or = 1 mm) in 97% of cases. With a mean follow-up of 36 months, no local recurrence was suspected. Twenty-six patients (84%) were alive, 23 free of disease. Half of the patients had perfect continence, whereas the other half had occasional minor soiling. Functional results were better in patients with a colonic pouch. CONCLUSION: Conservative treatment of carcinomas of the anorectal junction is possible without compromising pelvic control and patient survival. Pelvic control was probably achieved by using preoperative radiotherapy with intersphincteric resection, ensuring safe distal and lateral margins.

Adenocarcinoma↗

The immunocytochemical versus cytosol measurement of the oestrogen receptor in invasive breast cancer tissue.

To compare two methods of measurement of oestrogen receptor (ER)-expression in invasive breast cancer tissue. Sections from 299 breast cancer cases were stained for the ER by immunocytochemical assay (ICA), using mouse monoclonal antibody (MAb) NCL-ER-6SF11, and by the dextran-coated charcoal assay (DCC). Concordant results were observed in 230 of the 299 cases (77%), 69 patients had discordant results (kappa=0.537). We found a moderate concordance between ICA and DCC for ER measurement in breast cancer tissue. If we change the golden standard from DCC to ICA, 23% of patients would receive a different therapeutic approach.

Biomarkers, Tumor↗

Morbidity and functional outcome after double dynamic graciloplasty for anorectal reconstruction.

BACKGROUND: After abdominoperineal resection (APR), anorectal reconstruction with dynamic graciloplasty has been proposed to avoid abdominal colostomy and improve quality of life. Graciloplasties involving one or two gracilis muscles with various configurations have been described. The aim of this study was to evaluate morbidity and functional results in a homogeneous series of patients undergoing double dynamic graciloplasty following APR for rectal cancer. PATIENTS AND METHODS: : From May 1995 to May 1998, 15 patients (ten men and five women; mean age 54 (range 39-77) years) underwent anorectal reconstruction with double dynamic graciloplasty after APR for low rectal carcinoma. All patients had preoperative radiotherapy (45 Gy), 11 with concomitant chemotherapy, eight had intraoperative radiotherapy (15 Gy) and ten received adjuvant chemotherapy for 6 months. The surgical procedure was performed in three stages: APR with coloperineal anastomosis and double graciloplasty (double muscle wrap); implantation of the stimulator 2 months later; and ileostomy closure after a training period. RESULTS: There was no operative death. At a mean of 28 (range 3-48) months of follow-up, there was no local recurrence; two patients had lung metastases. Early and late morbidity occurred in 11 patients, mainly related to the neosphincter (12 of 16 complications). The main complication was stenosis of the neosphincter (n = 6), which developed with electrical stimulation. Of 12 patients available for functional outcome, seven were continent, two were incontinent and three had an abdominal colostomy (two for incontinence, one for sepsis). Compared with patients without stenosis, patients with neosphincter stenosis required major reoperations (four versus zero) and had a poor outcome (two of six versus five of six with a good result). CONCLUSION: The double dynamic graciloplasty is associated with a high risk of neosphincter stenosis, which may entail morbidity, reintervention and poor functional results. The stenosis is a heterogeneous feature of the neosphincter induced by asymmetrical traction of both gracilis muscles. It is suggested that single dynamic graciloplasty should be used for anorectal reconstruction after APR. Presented to the 101st congress of the Association Française de Chirurgie in Paris, France, October 1999, and to the European Council of Coloproctology in Munich, Germany, October-November 1999

Adenocarcinoma↗

Liver iron excess in patients with hepatocellular carcinoma developed on viral C cirrhosis.

BACKGROUND: Liver iron deposits are frequent in viral C cirrhotic patients but their role is not well defined. AIMS: To investigate the effect of liver iron excess on the prevalence of hepatocellular carcinoma (HCC) in patients with viral C cirrhosis. METHODS: Hepatic iron was evaluated retrospectively using a semiquantitative method in liver biopsies of 104 viral C cirrhotic patients, 48 with HCC and 56 controls (HCC free). Corrected total iron score (0-60) was defined by the sum of three scores: hepatocytic iron score (0-36), sinusoidal iron score (0-12), and portal iron score (0-12), multiplied by 3/3, 2/3, or 1/3 according to the heterogeneous iron localisation in the nodules. RESULTS: After adjustment for known risk factors for HCC, regression analysis showed that iron deposits (corrected total iron score >0) were more frequent in HCC patients than in controls (odds ratio 4.94; 95% confidence interval 1.59-15. 32; p=0.0056). The median of corrected total iron score was significantly higher in HCC patients than in controls (odds ratio 1. 092; 95% confidence interval 1.01-1.13; p=0.021). This liver iron overload was sinusoidal (odds ratio 5.2; 95% confidence interval 1. 82-15.11; p=0.0022). CONCLUSIONS: Liver iron deposition was more frequent and more important in viral C cirrhotic patients with HCC than in HCC free controls. Liver iron overload seems to contribute to the development of HCC in patients with viral C cirrhosis.

Adult↗

[Dieulafoy's duodenal ulcer. Report of two cases].

Two cases of Dieulafoy's ulcer of the duodenum revealed by a severe digestive bleeding and histologically proved are reported. It is a rare localization of a rare disease which is particular by the presence of an abnormal vessel in the sub-mucosa layer of the digestive wall. Both patients were operated on and successfully treated by excision suture.

Adult↗

Biological monitoring in waste landfills studies.

The assessment of exposure to chemicals from waste landfills and their health impact is a crucial, yet extremely difficult task in waste landfill studies. Use of biological markers, both of exposure and of health effects, may be very helpful if adequately chosen and precisely applied. They must be validated before application in risk assessment studies by establishing the relationship between the biomarker, exposure and the health outcome. Biomarkers suitable for the application in the waste landfill studies are reviewed in this paper.

Environmental Exposure↗