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Biomedical subjects

P Vincent

Publications and source records attributed to P Vincent.

At least 127 records · Page 7Linked to original sources
PubMed1992

[Current role of chemotherapy in the treatment of invasive cancers of the bladder].

Treatment of bladder carcinoma with cystectomy and or radiotherapy provide 5-year survival rates of 28-50%. Phase II chemotherapy trials have proven its efficacy with a partial and complete response rate of 20% and 10% respectively for drugs such as cisplatin or methotrexate. Recent phase III studies have demonstrated the superiority of associations such as CMV, CISCA or M-VAC with complete response rates of 28-39%. Neoadjuvant chemotherapy may increase local control and offer the possibility of conservative treatment after complete tumor regression (one third of cases). The positive effect of neoadjuvant chemotherapy on survival has not yet been demonstrated and randomized trials are now in progress. The concomitant association of cisplatin or fluorouracil with radiation therapy provides high complete response rates (65-88%) in all published studies. A longer follow-up period is necessary to confirm these results in terms of local control gain and survival benefit, but this strategy seems to constitute a major advancement for patients unable to undergo radical cystectomy. Further studies are needed before extending this conservative approach to less advanced invasive bladder carcinoma. Adjuvant chemotherapy may decrease metastasis rate, but survival benefit has not yet been definitively established by randomized studies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

[Bacterial translocation in Crohn disease].

Bacterial translocation is the passage of viable endogenous bacteria from the gastrointestinal tract to mesenteric lymph nodes and other internal organs. The aim of this work was to study bacterial translocation in patients operated on for Crohn's disease. Twenty-eight patients, mean age 29 years, not having received any antibiotics since at least 8 days, presenting with ileal (n = 12), ileo-colonic (n = 14) or colonic (n = 2) Crohn's disease were studied. In 25 out of 28 cases (89%) indication for surgery was strictures inducing an upper small bowel distension in 9 out of 25 patients. Mesenteric lymph nodes and liver biopsies, portal blood samples and peritoneum swabs were harvested after laparotomy and before gut opening. Bacterial translocation, defined as the presence of intestinal bacteria in at least one of the specimens, was present in 8 out of 28 patients. This was found in lymph nodes draining surgical territories in 7 out of 8 cases. Bacterial strains involved in translocation included E. coli (n = 5), Enterococcus (n = 3), Clostridium perfringens (n = 2), Proteus (n = 2), and Bacteroides fragilis (n = 1). The rate of translocation differed neither according to Crohn's disease site nor with perforating or non perforating type of the disease. Five out of 9 patients operated on for strictures with proximal distension had a translocation. In conclusion, bacterial translocation was identified in 29% of patients operated on for Crohn's disease in this series. Distension of the intestine proximal to a digestive stricture could favor the occurrence of bacterial translocation in Crohn's disease.

Adolescent↗
PubMed1992

The dimensional approach to clinical psychopharmacology: a polysemous concept.

The last decade has seen significant progress in the development and specific clinical application of selective psychotropes. The dimensional approach to clinical psychopharmacology views the behavioral targets of psychotropes as phenomena existing on a continuum and as components, in varying degrees, of most psychopathologies. The modern concept of dimension has been used in different contexts. In psychology it has a mathematical sense, whereas in biological psychiatry it is associated more with biological function. This paper reviews these two concepts and the recent models attempting to merge them into one. The heuristic value of the dimensional approach, as well as some of its pitfalls and new avenues of research, are discussed.

Adult↗
PubMed1991

Corpus callosum agenesis and psychosis in Andermann syndrome.

Recent illustrations by cerebral magnetic resonance imaging of anomalies of the corpus callosum in schizophrenics have kindled renewed interest in this association. We studied 62 patients affected by the Andermann syndrome, a polymalformative familial syndrome combining frequent congenital corpus callosum agenesis, mental retardation, psychotic episodes, peripheral neuropathy, and some dysmorphic features. Twenty of 62 patients presenting with psychosis were compared with 20 nonpsychotic patients matched according to sex and age. The psychotic patients presented an atypical psychosis as defined by the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, beginning in postadolescence. No significant relationship was observed between corpus callosum agenesis and psychosis. However, a significant association between posterior fossa atrophy and psychosis was established in our study. Although there are limitations in using cross-sectional data for this purpose, the findings suggest an association between cerebellar anomalies and schizophrenialike syndrome and rule out an implication of developmental callosal defects in such psychiatric disorders.

Adolescent↗
PubMed1991

Proteolysis of gelatin-bound fibronectin by activated leukocytes: a role for leukocyte elastase.

Fragmentation of subendothelial matrix-bound fibronectin by proteases released from stimulated leukocytes has been implicated in lung vascular injury. We studied the degradation of fibronectin bound to denatured collagen by inflammatory polymorphonuclear leukocytes (PMNL). Tissue culture wells coated with denatured collagen (gelatin) were pretreated with 125I rat plasma fibronectin to allow for fibronectin binding prior to the addition of rat inflammatory PMNL. The release of both intact and fragmented fibronectin from the 125I-labelled artificial matrix was quantified following the addition of PMNL stimulated by the phagocytosis of opsonized zymosan as well as leukocyte elastase. Stimulated PMNL released three times more radiolabelled fibronectin from the denatured collagen surface during a 4 h incubation as compared with unstimulated PMNL. This pattern of 125I-fibronectin release could also be elicited by the addition of purified leukocyte elastase alone, in the absence of PMNL. The release of radiolabelled fibronectin by stimulated PMNL was blocked in a dose-dependent manner by the addition of both methoxysuccinyl-alanine-alanine-valine chloromethyl ketone (AAPVCK), a leukocyte elastase specific inhibitor as well as phenylmethylsulfonylfluoride (PMSF), a non-specific serine protease inhibitor. Western blot analysis coupled with autoradiography confirmed the presence of fibronectin fragments in the medium after addition of PMNL or leukocyte elastase. The large molecular weight fragments (60-200 kD) were not labelled, but the smaller molecular weight fragments (less than 45 kD), derived from the artificial matrix, were labelled. Thus, fibronectin complexed with denatured collagen is susceptible to proteolytic degradation by stimulated inflammatory PMNL. Such a process may have a role in the pathogenesis of acute vascular injury following microvascular margination of activated blood leukocytes.

Amino Acid Chloromethyl Ketones↗
PubMed1991

Inhibitory effect of norcantharidin on K562 human myeloid leukemia cells in vitro.

Mylabris, the dried body of the Chinese blister beetle, has been used as a Chinese medicinal for over 2000 years. Its active constituent, cantharidin, has antitumor properties and causes leukocytosis. Norcantharidin (NCTD), the demethylated form of cantharidin, is easier to synthesize and is less toxic. NCTD irreversibly reduced the clonogenic efficiency of parental and drug-resistant K562 sublines, with drug-resistant sublines showing greater susceptibility to NCTD than parental cells. NCTD inhibited DNA synthesis by blocking cells at the G2/M phase of the cell cycle. The data suggest that NCTD may be suitable in the treatment of drug-resistant leukemia.

Antineoplastic Agents↗
PubMed1991

[Nitrates in the drinking water and cancer].

Nitrates originating from food and particularly from water are supposedly precursors of carcinogenic N-nitroso compound (NOC) formed within the organism. According to Correa and al. these transformations could be a consequence of bacterial gastric pullulation resulting from certain hypochlorhydric conditions. Much epidemiological research has tried to establish a relationship between exposure to nitrates in drinking water and cases of gastric cancer. The present article deals with research into this relationship in France, in a region where the rate of nitrates in water supplies is among the highest. Death statistics (from cancers of the digestive and urinal tracts) are issued by INSERM and these of the population by INSEE. Towns are classified according to nitrate concentration and the number of deaths is established according to tumour detection by sex and age. Research into death rate divergencies is found by chi 2 and the correlated coefficient. The average relative risk for any age group is calculated for all types of cancer. Research on frequency is carried out from tumour records. Comparative frequency rates are established by direct standardisation according to the structural age of any one European population. Results are analysed in relation to (1) mortality rates and (2) incidence rates. (1) None of the cancers studied, of the digestive or urinary systems, whatever the age on sex, is significantly linked to the quantity of nitrates in water supplies. When all these cancers are taken into account, the death rate does not vary significantly for increasing concentration of nitrates. Towns exceeding the maximum concentration permitted by law do not have a higher mortality rate than other towns.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Anti-Helicobacter pylori IgG levels in abattoir workers.

The aim of our study was to detect antibodies against Helicobacter pylori (H. pylori) in abattoir workers whose activity was variable (pig, poultry-carcasses, poultry-intestinal organs treatment). An adsorption of all sera with H. pylori and Campylobacter species known to be ubiquitous and responsible for zoonosis was included in the ELISA reaction to eliminate possible cross-reactions between these species. Statistically higher specific titres of IgG antibodies against H. pylori were observed in men and women who had only worked for 1 or 2 years versus matched controls, indicating a possible transmission of H. pylori from animal to man. The role of poultry or pigs as contaminants alone or in association remains to be determined.

Abattoirs↗
PubMed1991

[Nitrates in drinking water and cancer].

Nitrates originating from food and particularly from water are supposedly precursors of carcinogenic N-nitroso compound (NOC) formed within the organism. According to Correa and al. these transformations could be a consequence of bacterial gastric pollution resulting from certain hypochlorhydric conditions. Much epidemiological research has tried to establish a relationship between exposure to nitrates in drinking water and cases of gastric cancer. The present article deals with research into this relationship in France, in a region where the rate of nitrates in water supplies is among the highest. Death statistics (from cancers of the digestive and urinal tracts) are issued by INSERM and these of the population by INSEE. Towns are classified according to nitrate concentration and the number of deaths is established according to tumour detection by sex and age. Research into death rate divergencies is found by chi 2 and the correlated coefficient. The average relative risk for any age group is calculated for all types of cancer. Research on frequency is carried out from tumour records. Comparative frequency rates are established by direct standardisation according to the structural age of any one European population. Results are analysed in relation to (1) mortality rates and (2) incidence rates. (1) None of the cancers studied, be they of the digestive or urinary systems, whatever the age on sex, is significantly linked to the quantity of nitrates in water supplies. When all these cancers are taken into account, the death rate does not vary significantly for increasing concentration of nitrates. Towns exceeding the maximum concentration permitted by law do not have a higher mortality rate than other towns. The overall can incidence rate in the Nord-Pas-de-Calais regions of France is 11.8 per 100,000 inhabitants. The average European rate is 18.3 per 100,000 for men in the Nord region and 20.5 in the Pas-de-Calais; for women, 5.9 and 7.2 respectively. These rates are comparable to those in other French regions. The incidence rate for gastric cancer is not significantly different for inhabitants of towns exposed to water containing more or less than 50 mg/l. The absence of links between cancer and nitrates water research into possible methodological expedients necessary. A certain number of factors (consumer habits, diet, population mobility) can, for the same concentration of nitrates, modify the actual quantity consumed, and so the corresponding long-term risk. However, no inverse effect of these factors which would be susceptible to counter the link to the extent of concealing it, is know for the moment.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1990

E.S.R. spin trapping analysis of gamma induced radicals in sucrose.

Radicals induced by gamma-irradiation in sucrose, in the solid state at different temperatures and in aqueous solution, have been studied by the spin-trapping method. Electron spin resonance (ESR) combined with high performance liquid chromatography (HPLC) then spectra analysis with a simulation program (VOYONS), revealed seven main radical species. Their nitrogen and hydrogen splitting constants were compared with those obtained from fructose and glucose units. Assignments of chemical structures are discussed for three radical species.

Chemical Phenomena↗
PubMed1990

Bacterial translocation in colorectal cancers.

Bacterial translocation, the passage of viable indigenous bacteria from the gastrointestinal tract to the mesenteric lymph nodes and other internal organs, has been poorly studied in man to date. Pericolonic lymph nodes, liver, portal blood, and peritoneum specimens were harvested before antibiotics were administered during 20 operations for colorectal cancer and compared with those obtained in 20 operations for non colorectal conditions. Bacterial translocation, defined as the presence of intestinal bacteria in at least one of the specimens, was found in 13 patients (65 percent) in the colorectal cancer group as compared to 6 (30 percent) in the control group (p less than 0.05). The increased incidence of bacterial translocation in colorectal cancers was mainly due to the presence of bacteria in the pericolonic lymph nodes adjacent to the cancer. These findings suggest that intestinal bacteria translocate from the bowel lumen in a high proportion of patients with colorectal cancer and further stress the need for prophylactic antibiotics in colorectal cancer surgery.

Adenocarcinoma↗
PubMed1990

[Causes of failure in the curative treatment of cancer of the exocrine pancreas].

Causes of relapse are related to diagnostic delay, disagreement between early clinical diagnosis and post-surgical classification, poor performance status of patients, biological features, treatment modalities and particularly subclinical disease left after radical surgery. Gastro-intestinal specialists, radiologists, surgeons, pathologists, radiation and medical oncologists must come together to propose the best strategy: exactness of pre- and post-operative staging; surgical resection performed with minimal and acceptable morbidity after due consideration of all associated risk factors; accurate pathological examination with mention of tumoral diameter, capsular invasion, multicentricity, lymph nodes and venous involvement, pTNM classification; precise systematic external beam radiotherapy, which may be enhanced by 5-FU.

Neoplasm Staging↗