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P Vincent

Publications and source records attributed to P Vincent.

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

Electrical impedance of cultured endothelium under fluid flow.

The morphological and functional status of organs, tissues, and cells can be assessed by evaluating their electrical impedance. Fluid shear stress regulates the morphology and function of endothelial cells in vitro. In this study, an electrical biosensor was used to investigate the dynamics of flow-induced alterations in endothelial cell morphology in vitro. Quantitative, real-time changes in the electrical impedance of endothelial monolayers were evaluated using a modified electric cell-substrate impedance sensing (ECIS) system. This ECIS/Flow system allows for a continuous evaluation of the cell monolayer impedance upon exposure to physiological fluid shear stress forces. Bovine aortic endothelial cells grown to confluence on thin film gold electrodes were exposed to fluid shear stress of 10 dynes/cm2 for a single uninterrupted 5 h time period or for two consecutive 30 min time periods separated by a 2 h no-flow interval. At the onset of flow, the monolayer electrical resistance sharply increased reaching 1.2 to 1.3 times the baseline in about 15 min followed by a sustained decrease in resistance to 1.1 and 0.85 times the baseline value after 30 min and 5 h of flow, respectively. The capacitance decreased at the onset of flow, started to recover after 15 min and after slightly overshooting the baseline values, decreased again with a prolonged exposure to flow. Measured changes in capacitance were in the order of 5% of the baseline values. The observed changes in endothelial impedance were reversible upon flow removal with a recovery rate that varied with the duration of the preceding flow exposure. These results demonstrate that the impedance of endothelial monolayers changes dynamically with flow indicating morphological and/or functional changes in the cell layer. This in vitro model system (ECIS/Flow) may be a very useful tool in the quantitative evaluation of flow-induced dynamic changes in cultured cells when used in conjunction with biological or biochemical assays able to determine the nature and mechanisms of the observed changes.

Animals↗
PubMed2001

[Standards, Options and Recommendations for the surgical management of carcinoma of the endometrium].

CONTEXT: The "Standards, Options and Recommendations" (SOR) project, started in 1993, is a collaboration between the Federation of the French Cancer Centres (FNCLCC), the 20 French Cancer Centres and specialists from French Public Universities, General Hospitals and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcome for cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary group of experts, with feedback from specialists in cancer care delivery. OBJECTIVES: To develop clinical practice guidelines according to the definitions of the Standards, Options and Recommendations project for the surgical management of carcinoma of the endometrium. METHODS: Data were identified by searching Medline and personal reference lists of members of the expert groups. Once the guidelines were defined, the document was submitted for review to independent reviewers, and to the medical committees of the 20 French Cancer Centres. RESULTS: The main recommendations for the surgical management of carcinoma of the endometrium are: 1) where-ever possible, surgery is the primary treatment of both localised and advanced disease; 2) surgery is performed according to the stage of the cancer and the status of the patient; 3) surgery for stages I and II disease entails total abdominal hysterectomy and bilateral salpingo-oophorectomy. A modified radical hysterectomy is undertaken in cases of macroscopic cervical involvement. An omenectomy is recommended for serous papillary types. Pelvic lymphadenectomy for the purposes of precise staging is undertaken if the patient is of good performance status and without bad pronostic factors. Para-aortic lymphadenectomy can be undertaken to determine involvement of para-aortic nodes; 4) surgery for stages III and IV: radical surgery must be undertaken if at all possible with additional treatment as indicated. In the case of advanced disease, debulking surgery is indicated.

Algorithms↗
PubMed2001

[Standards, options, and recommendations for the radiotherapy of patients with endometrial cancer. FNCLCC (National Federation of Cancer Campaign Centers) and CRLCC (Regional Cancer Campaign Centers)].

OBJECTIVES: To develop clinical practice guidelines according to the definitions of the Standards, Options and Recommendations project for the radiotherapy of carcinoma of the endometrium. METHODS: Data were identified by searching Medline and personal reference lists of members of the expert groups. Once the guidelines were defined, the document was submitted for review to independent reviewers, and to the medical committees of the 20 French Cancer Centres. RESULTS: The main recommendations for the radiotherapy of carcinoma of the endometrium are: 1) For grade 1 and 2 stage IA tumours, follow-up alone is standard as additional treatment. For grade 1 and 2 stage IB tumours, vaginal brachytherapy or follow-up alone are options. For grade 3, stage IB tumours and stage IC disease, there are two treatment options: external pelvic radiotherapy with a brachytherapy boost or vaginal brachytherapy. 2) Treatment for stage II disease can be preoperative when stage II disease has been suggested by a positive endometrial curettage. Postoperative vaginal brachytherapy is given for stage IIA tumours if the penetration of the myometrium is less than 50% or if the tumour is grade 1 or 2. In the case of deep penetration, or higher grade disease, or for stage IIB external radiotherapy with brachytherapy boosting must be undertaken routinely. 3) After surgery, for stage IIIA disease, either external pelvic radiotherapy or abdomino-pelvic radiotherapy is indicated, along with medical treatment in certain patients. For stage IIIB tumours, postoperative external radiotherapy with brachytherapy (if possible) should be undertaken. For stage IIIC tumours, standard treatment is external (pelvic or pelvic and para-aortic) radiotherapy followed or not by a brachytherapy boost. In case of extrauterine sites involved abdomino-pelvic irradiation is recommended. 4) Standard treatment for inoperable stage I and II disease is external radiotherapy and brachytherapy. For patients with inoperable stage III or IV disease, treatment is often symptomatic, combining external radiotherapy and medical treatment.

Brachytherapy↗
PubMed2001

[Are there physical, technical and morphological limits to conformational radiotherapy?].

Conformal radiotherapy results from several technical and data processing advances. The treatment planning and the daily treatments have benefited from a significant improvement of the quality control. However, all the steps of the process contain various limitations of varying effects. It appear important to identify, describe and exploit those limits to better drive the procedures and optimise the quality. Identifying the limits of the conformal radiotherapy should be an important help to implement intensity modulation radiotherapy.

Anthropometry↗
PubMed2000

Optical imaging of calcium transients in neurons and pharyngeal muscle of C. elegans.

Electrophysiology and optical indicators have been used in vertebrate systems to investigate excitable cell firing and calcium transients, but both techniques have been difficult to apply in organisms with powerful reverse genetics. To overcome this limitation, we expressed cameleon proteins, genetically encoded calcium indicators, in the pharyngeal muscle of the nematode worm Caenorhabditis elegans. In intact transgenic animals expressing cameleons, fluorescence ratio changes accompanied muscular contraction, verifying detection of calcium transients. By comparing the magnitude and duration of calcium influx in wild-type and mutant animals, we were able to determine the effects of calcium channel proteins on pharyngeal calcium transients. We also successfully used cameleons to detect electrically evoked calcium transients in individual C. elegans neurons. This technique therefore should have broad applications in analyzing the regulation of excitable cell activity in genetically tractable organisms.

Animals↗
PubMed2000

[Carboplatin in cancer of the ovary].

Platinum is the standard drug in the treatment of patients with ovarian cancer. The sample of more than 2,000 patients enrolled in randomised trials and 2 meta-analyses were largely sufficient to prove that carboplatin and cisplatin are equally effective. Carboplatin dose adaptation according to renal function and AUC decreases drug induced thrombopenia and has allowed carboplatin to be used widely and safely. Combining carboplatin with paclitaxel has brought additional protection against thrombopenia. The carboplatin-paclitaxel regimen can be safely administered every 3 weeks in an outpatient setting assuring a better quality of life than the combination of cisplatin and paclitaxel with equal efficacy. Carboplatin-paclitaxel has thus recently become the standard chemotherapy regimen for patients with advanced ovarian cancer. Forthcoming results of ongoing trials will determine if high carboplatin doses with peripheral hematopoeitic stem cell support in consolidation after first line treatment can benefit patients with advanced disease.

Antineoplastic Agents↗
PubMed1999

One of the origins of plasma membrane phosphatidylserine in plant cells is a local synthesis by a serine exchange activity.

In plant cells, as in animal cells, the endoplasmic reticulum (ER) is considered to be the major site of phospholipid synthesis, and it has been shown that phosphatidylserine (PS) reaches the plasma membrane via the vesicular ER-Golgi-plasma membrane pathway in leek cells. However, it has never been determined whether the plasma membrane of leek cells is able to synthesize PS. We have analyzed the distribution of PS synthesizing enzymes along the vesicular pathway. In ER, Golgi and plasma membrane fractions isolated from leek cells, we have measured the activity of the two biosynthetic pathways leading to the synthesis of PS, i.e. serine exchange and CTP cytidylyltransferase plus PS synthase. We have found a high serine exchange activity in the plasma membrane fraction, and then determined that this membrane is able to synthesize both long chain fatty acid- and very long chain fatty acid-containing PS. Therefore, the PS in the plasma membrane of leek cells has two different origins: the intracellular vesicular pathway from the ER and a local synthesis in the plasma membrane.

CDPdiacylglycerol-Serine O-Phosphatidyltransferase↗
PubMed1999

The accordionist

Explore the source record for details and available documents.

Journal Article↗
PubMed1999

Wagner vitreoretinal degeneration with genetic linkage refinement on chromosome 5q13-q14.

BACKGROUND: It has been previously described that Wagner disease is linked to chromosome 5q13-q14. This study was carried out to describe the ophthalmological aspects and report the results of genetic linkage analysis in a large pedigree affected by Wagner disease. METHODS: Fourty members of one same family agreed to be examined. RESULTS: Twenty patients presented vitreoretinal degeneration in both eyes without any extra-ocular abnormalities. In young patients, visual acuity was usually normal after correction of frequent mild myopia. Presenile cataracts progressed by the third decade and required removal for visual rehabilitation. The primary disorder involved an abnormal vitreous. A few avascular vitreous bands were usually the only optical feature in the mostly empty vitreous cavity. A circumferential vitreous condensation formed in contact with the retina on many spots. Less common retinal findings included retinal detachment, abnormal retinal pigmentation, progressive atrophy of the RPE simulating choroideremia and lattice degeneration. Genetic analysis revealed a highly significant linkage (lod score >5.0) between the disease and 10 markers of the chromosome 5q13-q14 region. Two recombination events allowed us to refine the linked interval to 20 cM between the D5S650 and D5S618 markers. CONCLUSION: Ophthalmological aspects of Wagner's disease appear to progress with age. Regular ophthalmological examination is important for detecting retinal abnormalities. The gene involved in Wagner's disease lies in a 20 cM interval on chromosome 5q13-q14.

Adolescent↗
PubMed1999

13C-urea breath test and gastric mucosal colonization by Helicobacter pylori in children: quantitative relation and usefulness for diagnosis of infection.

OBJECTIVE: Because in children Helicobacter pylori colonization could differ as compared to that in adults, gastric metabolism of urea and the reliability of the breath test must be evaluated. The aim of this study was to quantify the relationship between breath test and colonization. METHODOLOGY: We studied data from 50 endoscopies performed in 39 children and adolescents (20 girls, 19 boys, aged 3-18 years); 28 were infected with H. pylori. Biopsies were analyzed for histological and microbiological diagnosis of infection and for quantitative antral culture of H. pylori. A 13C urea breath test was performed on the same day as that of endoscopy (n = 33) or delayed between 2 and 90 days (n = 17). RESULTS: Using a cut-off value of 3 delta/1000, sensitivity was 96.5%, and specificity was 91.5%. The three children showing discrepancies between breath test and biopsy results had a delta/1000 value close to the cut-off. For the 26 cases with a positive culture, we noted a significant correlation (r = 0.63; p < .001) that was not affected by the delay between breath test and gastroscopy. CONCLUSION: This quantitative relation between bacterial density and delta/1000 permits increasing the reliability of the test by interpreting carefully those results that approach the cut-off value.

Adolescent↗
PubMed1999

Molecular epidemiology of tuberculosis in the Nord Department of France during 1995.

In order to determine the current situation and to evaluate the human to human transmission of Mycobacterium tuberculosis in Northern France, the genetic polymorphism of strains was studied by using IS6110 fingerprint. One hundred and fifty-eight cases of bacteriologically confirmed tuberculosis were analyzed. One hundred and twenty-six patients (82%) were infected with genetically different isolates and 28 isolates (18%) were grouped into 14 clusters. No risk factors for recent Mycobacterium tuberculosis infections such as age, HIV status, immigrants, living in big cities were identified. This study shows that there was no major epidemic situation of tuberculosis in Northern France in 1995. Tuberculosis was characterized by a low proportion of HIV positive patients and a high proportion of elderly patients.

AIDS-Related Opportunistic Infections↗
PubMed1999

The treatment of negative symptoms: a clinical and methodological study.

The primary objective of this study was to evaluate the efficacy, safety and tolerability of remoxipride (controlled release) versus haloperidol in patients with negative symptoms. The study comprised a multicentre, randomised, double-blind, parallel-group clinical trial. Two hundred and five patients were randomised to either remoxipride or haloperidol. Patients eligible for this study were aged 18-65 years, met the DSM-III-R diagnosis for chronic schizophrenia and the Positive and Negative Symptoms Scale (PANSS) criteria for predominant negative symptoms. There was a statistically significant reduction in the PANSS scores of at least 20% from baseline to last rating for 39 remoxipride (49.4%) and 45 haloperidol (47.6%) treated patients. There were no statistical differences found between the two treatment groups with respect to improvement of negative symptoms and adverse events. The PANSS data suggest that both remoxipride and haloperidol improve the cluster of negative symptoms concerned with social functioning. In addition, the design of the study provides a methodology that is appropriate to the study of primary negative symptoms in schizophrenia.

Adult↗
PubMed1999

Characteristics and prevalence of Helicobacter heilmannii infection in children undergoing upper gastrointestinal endoscopy.

BACKGROUND: Helicobacter heilmannii, described in 1983 as a new cause of chronic gastritis, has been reported rarely in children. The purpose of this study was to determine the clinical characteristics and the prevalence of H. heilmannii infection, in comparison with Helicobacter pylori infection in children undergoing upper digestive endoscopy. METHODS: Diagnosis of H. heilmannii was based on its morphologic characteristics in gastric biopsy specimens (two from the antrum, one from the fundus), whereas H. pylori infection was defined by histology and/or culture (one specimen from the antrum, one from the fundus). Respective prevalences of H. heilmannii and H. pylori were calculated in 518 patients studied prospectively who underwent systematic biopsies. RESULTS: The prevalence of H. pylori was 8.9% (46/518) and increased with age (from 2% before 3 years of age to 18% after 10 years). On the contrary, the prevalence of H. heilmannii infection was low, 0.4% (2/518), and no different from that published in adults. After completion of the study period, a third H. heilmannii-infected child was diagnosed. Characteristics of H. heilmannii infection could be studied in these three children 5, 9, and 14 years old. Two of three had abdominal pain and one had dysphagia. Nodular gastritis was observed at endoscopy in two children. H. heilmannii chronic active gastritis (n = 3) was localized in the antrum, associated with an interstitial infiltrate, and could not be distinguished from H. pylori gastritis (n = 46). CONCLUSION: Clinical characteristics, endoscopic features and gastric histopathology did not allow H. heilmannii to be distinguished from H. pylori gastritis in our pediatric population. H. heilmannii infection should be considered and carefully looked for during histologic examination of gastric specimens in cases of H. pylori-negative gastritis.

Adolescent↗
PubMed1999

ATP-Dependent formation of phosphatidylserine-rich vesicles from the endoplasmic reticulum of leek cells

Leek (Allium porrum) plasma membrane is enriched in phosphatidylserine (PS) by the vesicular pathway, in a way similar to that already observed in animal cells (B. Sturbois-Balcerzak, D.J. Morre, O. Loreau, J.P. Noel, P. Moreau, C. Cassagne [1995] Plant Physiol Biochem 33: 625-637). In this paper we document the formation of PS-rich small vesicles from leek endoplasmic reticulum (ER) membranes upon addition of ATP and other factors. The omission of ATP or its replacement by ATPgamma-S prevents vesicle formation. These vesicles correspond to small structures (70-80 nm) and their phospholipid composition, characterized by a PS enrichment, is compatible with a role in PS transport. Moreover, the PS enrichment over phosphatidylinositol in the ER-derived vesicles is the first example, to our knowledge, of phospholipid sorting from the ER to ER-derived vesicles in plant cells.

Journal Article↗
PubMed1999

Natural outcome of Helicobacter pylori infection in asymptomatic children: a two-year follow-up study.

BACKGROUND AND OBJECTIVES: It is known that Helicobacter pylori can be acquired in early childhood. There is not enough data to know whether or not infected children should be treated. A better knowledge of the natural outcome and implications of H pylori infection may provide evidence that eradication therapy is beneficial in childhood. This prospective study looks at clinical symptoms, endoscopic, microbial, and histologic changes during a 2-year period in infected asymptomatic children. It is hoped that some prognostic indicators will be found that select out the children that later need therapy. PATIENTS AND METHODS: During epidemiologic study of the prevalence of H pylori infection, 18 children aged 7 +/- 4 years (mean +/- 1 SD) were discovered to have H pylori infection and enrolled in the 2-year follow-up study. These patients had received no eradication therapy because they were asymptomatic. The follow-up for each patient consisted of an initial assessment, a clinical examination every 6 months, and an endoscopic reevaluation at the end of the first and second years. Gastric mucosal samples were analyzed for bacteriologic and histologic changes. Various factors were initially recorded: individual factors included sex, age, and housing conditions; microbial factors included bacterial load and the presence of the CagA gene. Inflammatory changes were also noted, such as the presence of active gastritis and nodular formation, and these were correlated with the histology which was described using the Sydney classification. Typing polymerase chain reaction-restriction fragment length polymorphism was performed to check the persistence of the same strain of H pylori in each patient. RESULTS: All of the children were still infected after 2 years with the same strain as in the initial assessment with the exception of 1 child whose infection cleared spontaneously. The density of antral and fundal mucosal colonization with H pylori also remained stable. There were progressive inflammatory changes in this cohort, particularly between the first and second year (histologic score, 3.5 +/- 1.3 vs 5 +/- 1). Active antral gastritis occurred in 3 out of 14 and 1 out of 8 children during the first and second year, respectively. Gastritis became active in the fundus in 2 out of 14 and 2 out of 8 children during the same period. Increases in the histologic score were found particularly in male children, and children colonized by cagA- strains of H pylori during the follow-up. The frequency of nodular gastritis significantly rose from 11% (2 out of 18 children) to 64% (9 out of 14 children) after 1 year, and to 80% (8 out of 10 children) after 2 years. CONCLUSION: These findings demonstrate a deterioration in the histologic features of the gastric mucosa of infected children despite stable H pylori colonization and the absence of symptoms.

Antigens, Bacterial↗