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D Couturier

Publications and source records attributed to D Couturier.

At least 55 records · Page 3Linked to original sources
PubMed1997

Endothelial calcium-calmodulin dependent nitric oxide synthase in the in vitro vascular hyporeactivity of portal hypertensive rats.

BACKGROUND/AIMS: Increased nitric oxide production has been implicated in impaired vascular responsiveness to vasoconstrictors in portal hypertension. However, there is no firm evidence concerning the involved nitric oxide synthase isoform. The present study investigated the possible contribution of one nitric oxide synthase isoform, the endothelial constitutive Ca2+-calmodulin dependent, in the overproduction of nitric oxide in portal hypertension. METHODS: Vascular responses to norepinephrine and acetylcholine were evaluated in isolated thoracic aortic rings from normal and portal vein stenosed rats. RESULTS: An impaired concentration-dependent contraction to norepinephrine was observed in intact rings from portal hypertensive rats compared to controls. The hyporeactivity to norepinephrine was reversed after endothelium denudation, the inhibition of nitric oxide synthase with L-NOARG or the inhibition of calmodulin with W-7, but not after pre-incubation with indomethacin. Stimulation of intact rings with norepinephrine after the inhibition of calmodulin with calmidazolium was followed by a decreased vascular response in vessels from normal rats but not in those from portal hypertensive rats. Stimulation of intact rings with norepinephrine in a Ca2+-free medium was followed by a decreased vascular response in vessels from both portal hypertensive and normal rats. No difference in vasoconstrictive responses was observed between the two groups after calmidazolium or in a Ca2+-free medium. Relaxation induced by acetylcholine in norepinephrine-precontracted rings was more marked in rings from portal hypertensive rats than in controls. No differences in the vasodilator responses were observed after relaxations had been inhibited by the removal of the endothelium, pre-incubation with L-NOARG, indomethacin, W-7 or calmidazolium and in a Ca2+-free medium. CONCLUSIONS: This study demonstrates the involvement of the endothelial constitutive Ca2+-calmodulin dependent nitric oxide synthase isoform in the overproduction of nitric oxide in portal hypertension.

Animals↗
PubMed1997

Endosonographic features of esophageal granular cell tumors.

BACKGROUND AND STUDY AIMS: Granular cell tumors of the esophagus are rare tumors. A definite diagnosis is achieved by endoscopic biopsies in only 50% of cases. Endoscopic ultrasonography (EUS) is the best procedure in the evaluation of upper gastrointestinal tract submucosal tumors. The aim of this study was to describe the endosonographic findings of esophageal granular cell tumors. METHODS: From January 1989 to March 1994, 15 patients with 21 granular cell tumors which had negative biopsies were examined by EUS (Olympus GF UM3 or GF UM20,7,5 and 12 MHz). In five cases, the tumor was also studied with a 20 MHz Olympus miniprobe. The final histological diagnoses were obtained by subsequent endoscopic snare resection in 20 cases and surgically in one case. RESULTS: The endosonographic features (with the GF UM3 or GF UM20) of esophageal granular cell tumors were: a) a tumor size of less than 2 cm in 95% of cases; b) an hypoechoic solid pattern in 100% of cases; c) a tumor arising in the inner layers in 95% (second echo-poor layer n=15; third echo-rich layer n=5). In one case, the endosonographic finding was transmural malignant infiltration of the esophageal wall (histologically confirmed). CONCLUSION: When a granular cell tumor of the esophagus is suspected, EUS can show the inner layer location of the tumor and thus contribute to planning the endoscopic resection or follow up. When the tumor also invades the outer layers, EUS can contribute to planning the surgical resection.

Endosonography↗
PubMed1997

Bone assessment in patients with ileal pouch-anal anastomosis for inflammatory bowel disease.

BACKGROUND: Patients with ulcerative colitis are at risk of low bone mineral density (BMD). Proctocolectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative colitis diminishes the risk of bone disease. The aims of this study were to assess the mechanism of low BMD and to measure bone density changes after IPAA. METHODS: Twenty patients with IPAA for ulcerative colitis, of mean(s.d.) age 38(9) (range 21-58) years, had measurements of lumbar spine and femoral neck BMD by dual energy X-ray absorptiometry, a mean(s.d.) 28(23) (range 3-84) months after proctocolectomy. Serum levels of calcium, phosphate, parathyroid hormone, osteocalcin and 25-hydroxy vitamin D were determined. Fifteen patients were followed for 28(12) (range 8-50) months. RESULTS: At baseline, six patients had spine BMD more than two standard deviations below the normal value, and three had vertebral crush fractures. Mean vitamin D values were normal and no patient had osteomalacia. BMD increased with time elapsed since IPAA (spine: r = 0.71, P = 0.005). During follow-up, mean(s.d.) changes in bone density were +2.3(3.8) and +2.1(5.6) per cent per year at the spine and femoral neck respectively. CONCLUSION: These results suggest that in patients with IPAA for ulcerative colitis, low BMD is not associated with vitamin D malabsorption and may be reversible after surgery.

Adult↗
PubMed1997

[Colorectal carcinogenesis, frequency and significance of genetic alterations: deletion of the short arm of chromosome 1, and initiating event].

Cytogenetic anomalies described in colo-rectal tumors are numerous. Despite the complexity and the number of the anomalies observed, a combined study of their frequency and of the stage of prognosis of the tumors suggests that the evolution from colonic adenoma to carcinoma often follows a sequence of events comprising a 5q15-22 deletion (DCC), and a 17p deletion (P53). It even seems likely that in many cases, these events are not constant and that others might lead to the same phenotypic transformation. Chromosome 1 involvement in structural rearrangements has been demonstrated in numerous forms of cancers, malignant blood disorders and in solid tumors. In colorectal adenocarcinoma anomalies have been described on short and/or long arms. In a case of adenoma with mild dysplasia a deletion of the distal part of the short arm of chromosome 1 was observed as an isolated cytogenetic anomaly, suggesting it would be an early, perhaps triggering, event for the tumour development. A cytogenetic study in a series of colo-rectal tumours, researches on loss of heterozygosity and microsatellite instability lead to consider deletions at chromosome 1p as an early event in human colorectal tumourigenesis.

Chromosome Deletion↗
PubMed1996

Endosonographic features of pancreatic metastases.

BACKGROUND: Pancreatic metastasis is a rare event. Surgical resection can provide long-term survival in selected cases. The aim of this study was to describe the endosonographic features of pancreatic metastases. METHODS: Among the 7000 endoscopic ultrasound (EUS) examinations of the pancreas performed between 1989 and 1993, 7 were performed in patients with pancreatic metastases that were histologically confirmed (6 by surgery, 1 by CT biopsy). Videotapes of the EUS procedures were re-examined. Metastases were from four renal cell carcinomas, one ovary carcinoma, one chondrosarcoma, and one neuroendocrine carcinoma of the gallbladder. RESULTS: A solitary lesion was imaged by EUS in six cases and 10 lesions were seen in one case. Fifteen of 16 lesions were slightly hypoechoic or isoechoic in comparison with the adjacent pancreas. They were homogeneous, round, well circumscribed and were associated with an enhancement of the ultrasonic beam. The association of these ultrasonographic patterns was different from that usually observed in cases of primary pancreatic carcinoma. In one case (ovary carcinoma), the lesion was hypoechoic, with heterogeneous infiltration and indistinct margins and with the marked attenuation of the ultrasonic beam that is commonly noticed in primary pancreatic carcinoma or in focal chronic pancreatitis. CONCLUSION: Endosonographic features of pancreatic metastasis are usually different from those observed in cases of pancreatic carcinoma.

Adult↗
PubMed1996

Could oral erythromycin optimize high energy continuous enteral nutrition?

BACKGROUND: Intravenous erythromycin has previously been reported to stimulate gastric emptying, to inhibit gastric acid secretion and to stimulate pancreatic secretion during continuous gastric infusion of a liquid diet in healthy volunteers. AIM: The aim of this study was to evaluate the effects of oral erythromycin (160 mg/h) on gastrointestinal function under these conditions in seven healthy subjects. METHOD: This randomized double-blind cross-over study measured the gastric emptying rate of nutrients, gastric acid secretion, gastric pH, jejunal flow rate as well as biliopancreatic secretion and duodeno-caecal transit time during a 19.9 kJ/min continuous infusion of a nutrient solution (4.18 kJ/mL) in the antrum over a 6-h period by a perfusion method. RESULTS: The nutrition was well tolerated except by one subject with placebo perfusion. During the 6-period, total gastric volume and gastric volume of nutrient decreased during erythromycin administration by 22 +/- 8 and 22 +/- 6%, respectively. Gastric acid secretion was not modified by erythromycin. Lipase and bile salt outputs were significantly higher with erythromycin. The duodeno-caecal transit time was not statistically different with drug and placebo (169 +/- 15 and 146 +/- 19 min, respectively). CONCLUSION: During continuous gastric infusion of a liquid diet, the effect of oral erythromycin on gastric emptying could be useful to optimize cyclic enteral nutrition or to enhance the tolerance of enteral nutrition.

Administration, Oral↗
PubMed1996

Multifocal stenosing ulcerations of the small intestine revealing vasculitis associated with C2 deficiency.

A patient with cryptogenic multifocal ulcerous stenosing enteritis characterized by repeated bouts of intestinal obstruction, ulcerative stenosis of the small bowel relapsing after surgical resection, and steroid sensitivity is described. Fourteen strictures of the jejunum were found at laparotomy. Despite resection, abdominal pain persisted. Steroid therapy was effective but led to dependence. In our patient, cryptogenic multifocal ulcerous stenosing enteritis was associated with fever, asthma, Raynaud's phenomenon, sicca syndrome, heterozygous type I C2 deficiency (28-base pair gene deletion), stenosis, and aneurysms in selective mesenteric angiography. It is hypothesized that cryptogenic multifocal ulcerous stenosing enteritis might be related to a particular form of polyarteritis nodosa with mainly intestinal expression or to a yet unclassified independent vasculitis.

Adult↗
PubMed1996

Risk factors of oesophageal perforation during pneumatic dilatation for achalasia.

BACKGROUND/AIMS: Pneumatic dilatation of the oesophagus is a well established treatment for achalasia. Oesophageal perforation is the most serious complication that occurs in 2% to 6% of cases. The aim of this retrospective survey was to identify predictive risk factors for perforation in a consecutive series of 218 patients with achalasia. METHODS: Between 1983 and 1993, 270 pneumatic dilatations were performed in 218 patients. A Witzel dilator was used in 58 cases and a Rigiflex dilator in 212. Eight oesophageal perforations occurred (3%). The clinical, radiological, endoscopic, manometric, and technical data for the eight perforated patients were compared with those of 30 patients randomly sampled among those without perforation. RESULTS: All perforations occurred during the first dilatation. Perforations were fewer during dilatations with the Rigiflex dilator than with the Witzel dilator (2.4% v 5.2%). Perforations were all located above the cardia, on the left side of the oesophagus. In a multivariate analysis, a small weight loss and a high amplitude of oesophageal contractions in the group of patients with perforations were predictive of complications (respectively, p = 0.001 and p = 0.026). A contraction amplitude higher than 70 cm H2O in the lower part of the oesophagus was observed in three of eight patients with perforations but was not seen in any of the 30 patients without perforation (p < 0.01). CONCLUSIONS: This identification of risk factors should facilitate the choice between pneumatic dilatation or a surgical approach.

Aged↗
PubMed1996

[Peritoneal mesothelioma revealed by episodes of recurrent spontaneous peritonitis].

A case of a malignant peritoneal mesothelioma revealed by recurrent episodes of peritonitis is reported. This presentation had never been described. A 54 year-old man presented successive episodes of appendicitis, cholecystitis and sigmoiditis associated with purulent aseptic peritonitis. There were no signs of immunodepression or vasculitis. Initial analysis of peritoneal biopsies showed non specific inflammation. Because of long-term asbestos exposure, these biopsies were reviewed. A diagnosis of peritoneal mesothelioma was made on subserous infiltration by mesothelioma cells, and confirmed by immunohistochemistry. The patient died ten months after the diagnosis of mesothelioma despite chemotherapy (cisplatine+interferon).

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Bone loss in patients with inflammatory bowel disease: a prospective study.

To assess the rate of bone loss in patients with inflammatory bowel disease, we prospectively studied 35 patients (17 women) aged 36 +/- 13 (range 17-60) years, 14 of whom had Crohn's disease and 21 with ulcerative colitis (including 12 with ileoanal anastomosis). Bone mineral density was measured by dual-energy X-ray absorptiometry at the lumbar spine and femoral neck. The follow-up was 19 +/- 8 months. During this period, 14 patients received oral steroids. Lumbar bone density changes expressed as a percentage per year were -3.1 +/- 4.9%, -6.4 +/- 7.5% and +2.0 +/- 4.0% in Crohn's disease and ulcerative colitis without and with ileoanal anastomosis respectively (p = 0.007). The same pattern was observed at the femoral neck. Mean annual lumbar bone density changes were -6.2 +/- 7.0% and +0.9 +/- 3.9% in patients with and without steroids during follow-up (p = 0.002). We conclude that patients with inflammatory bowel disease are at risk of lumbar and femoral bone loss. However, bone loss is not observed in patients with ileoanal anastomosis.

Absorptiometry, Photon↗
PubMed1995

Intraluminal excretion of PAF, lysoPAF, and acetylhydrolase in patients with ulcerative colitis.

PAF-acether (PAF) is a phospholipid synthesized by numerous inflammatory cells. PAF can produce several pathological changes in various organs, especially in the colon. In animals PAF causes colonic ulceration and inflammation, which are similar to the anatomic lesions seen in human ulcerative colitis. The aim of this study was to measure in vivo colonic production of PAF in active ulcerative colitis using a modified colonic perfusion method. Ten patients with active ulcerative colitis and six control patients were investigated. A colonic segment was continuously perfused with a buffer and the liquid was recovered 20 cm distally, after a 45-min period of equilibration, at 20-min intervals. PAF, lysoPAF, and acetylhydrolase were measured in the colonic samples. PAF and lysoPAF outputs were significantly higher in patients with active ulcerative colitis compared to controls patients. There was a significant correlation between colonic PAF output and, respectively, macroscopic mucosal lesions and myeloperoxidase colonic output. We thus conclude: (1) the colonic perfusion method allows in vivo study of the metabolism of PAF during ulcerative colitis and could also be used to study the efficiency of PAF antagonists in UC; and (2) colonic production of PAF is increased during ulcerative colitis and correlated to local injury and inflammation. Whether or not PAF plays a role in the pathogenesis of ulcerative colitis remains open for further investigations.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1995

Metabolic bone assessment in patients with inflammatory bowel disease.

BACKGROUND/AIMS: Patients with inflammatory bowel disease are at risk for osteopenia. To study the metabolic bone status of these patients, a cross-sectional study was conducted. METHODS: Eighty-four patients (49 women, 35 men) with inflammatory bowel disease, 34 of whom had Crohn's disease and 50 ulcerative colitis (including 18 with prior coloproctectomy and ileoanal anastomosis), underwent clinical, dietary, and spine radiological assessments. Bone metabolism was assessed by measuring serum levels of calcium, phosphate, parathyroid hormone (1-84), 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and osteocalcin. Lumbar and femoral neck bone mineral densities were measured by dual energy X-ray absorptiometry. RESULTS: Serum osteocalcin level was decreased in 29 patients (34%), 12 of whom had never undergone steroid therapy. The other biochemical markers of bone metabolism were in the normal range. Thirty-six patients (43%) had osteopenia, and 6 patients (7%) had vertebral crush fractures. Osteopenia was observed in 27 patients (52%) and 9 patients (28%) with and without corticosteroid therapy, respectively. No patient had clinical or biological signs of osteomalacia. Analysis of bone density (lumbar Z score) by a multiple regression analysis showed a statistically significant correlation with age, cumulative corticosteroid doses, sedimentation rate, and osteocalcin level (R2 = 0.76; P = 0.05). CONCLUSIONS: The results suggest that bone turnover in inflammatory bowel disease is characterized by low bone formation in the presence of normal levels of calcium-regulating hormones.

Adolescent↗
PubMed1995

Absence of human papillomavirus DNA detected by polymerase chain reaction in French patients with esophageal carcinoma.

BACKGROUND & AIMS: Recent studies have suggested that esophageal human papillomavirus infection could be a risk factor for esophageal squamous cell carcinoma. The aim of this study was to evaluate the prevalence of human papillomavirus DNA sequences in the esophagus of French patients with esophageal squamous cell carcinoma. METHODS: Multiplex polymerase chain reactions with consensus primers directed to the L1 gene or specific primers for human papillomavirus types 6, 11, 16, 18, 31, and 33 directed to E6 gene (40 cycles followed by restriction mapping of the amplified products) were used to determine the presence of human papillomavirus DNA sequences in esophageal squamous cell carcinoma (n = 75), normal adjacent mucosa (n = 49), and metastatic lymphadenopathies (n = 5). As an internal control, a target located in the embryonic myosin heavy-chain gene was used in each reaction. RESULTS: Human papillomavirus DNA sequences could not be detected in any of the tumoral samples, the normal adjacent mucosa, or the metastatic lymphadenopathies. CONCLUSIONS: Human papillomavirus seems not to be implicated in esophageal carcinogenesis, at least in French patients, because the viral genomes are not associated with esophageal squamous cell carcinomas.

Adult↗
PubMed1995

Value of endoscopic ultrasonography in the diagnosis of common bile duct stones: comparison with surgical exploration and ERCP.

An accurate and safe preoperative method of imaging the common bile duct is essential for the proper diagnosis of calculous biliary tract disease, especially in the current era of laparoscopic cholecystectomy. The value of endoscopic ultrasonography in detecting common duct stones has been reported, albeit in small series. The aim of this retrospective study was to assess the accuracy of EUS in a large series of patients. We compared EUS to direct cholangiography in the evaluation of 422 patients for common duct stones. Ductal stones were imaged by EUS in 168 patients (43.4%). No complications were encountered. EUS failed in 2.3% of cases, ERCP failed in 8.3%, and surgical exploration failed in 0.5%. Comparison of EUS with surgical exploration in 185 patients showed a sensitivity of 94.9%, a specificity of 97.8%, and an accuracy of 95.9%. EUS was compared to ERCP in 219 patients. All common duct stones found by ERCP were evident by EUS. Concordance was obtained in 91.3% of cases. Review of videotapes disclosed 3 false-positives and 16 unequivocal true-positives. We conclude that EUS is a safe and highly accurate means of detecting common duct stones and should be proposed before laparoscopic cholecystectomy in patients at risk of choledocholithiasis.

Adolescent↗
PubMed1995

Effects of erythromycin on gastric emptying, duodeno-caecal transit time, gastric and biliopancreatic secretion during continuous gastric infusion of a liquid diet in healthy volunteers.

OBJECTIVE: Erythromycin, a macrolide antibiotic, has been reported to increase gastric emptying. The aim of this study was to evaluate the effects of intravenous erythromycin (150 mg/h) on gastric emptying, small intestinal transit time, gastric and biliopancreatic secretions during gastric infusion of a liquid diet in healthy volunteers. DESIGN: A randomized double-blind crossover study (erythromycin versus placebo). METHODS: Gastric emptying rates of nutrients, gastric acid secretion, gastric pH, jejunal flow rates, as well as biliopancreatic secretions and duodeno-caecal transit time, were evaluated during a continuous infusion at 4.5 kcal/min of a nutrient solution (1 kcal/ml) in the antrum, over a 6 h period, by a perfusion method. RESULTS: During the 6 h period, total gastric volume and gastric acid secretion decreased during erythromycin administration of 37 and 22%, respectively (area under the curves). Lipase outputs were significantly higher with erythromycin than placebo. Bile salt output was not significantly different between erythromycin and placebo. Duodeno-caecal transit time increased significantly during erythromycin infusion compared with placebo (191 +/- 12 versus 159 +/- 17 min; P < 0.05). CONCLUSION: During continuous gastric infusion of a liquid diet, intravenous erythromycin has a powerful effect on gastrointestinal function. The motor and secretory effects may enhance the tolerance and the efficiency of enteral nutrition in humans.

Adult↗