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M Dagenais

Publications and source records attributed to M Dagenais.

At least 19 recordsLinked to original sources
PubMed2003

Comparison of gemcitabine versus the matrix metalloproteinase inhibitor BAY 12-9566 in patients with advanced or metastatic adenocarcinoma of the pancreas: a phase III trial of the National Cancer Institute of Canada Clinical Trials Group.

PURPOSE: To compare the selective matrix metalloproteinase inhibitor BAY 12-9566 with the nucleoside analog gemcitabine in the treatment of advanced pancreatic cancer. METHODS: Patients with advanced pancreatic adenocarcinoma who had not previously received chemotherapy were randomly assigned to receive BAY 12-9566 800 mg orally bid continuously or gemcitabine 1,000 mg/m2 administered intravenously on days 1, 8, 15, 22, 29, 36, and 43 for the first 8 weeks, and then days 1, 8, and 15 of each subsequent 28-day cycle. The primary end point was overall survival; secondary end points were progression-free survival, tumor response, quality of life, and clinical benefit. The planned sample size of the study was 350 patients. Two formal interim analyses were planned. RESULTS: The study was closed to accrual after the second interim analysis on the basis of the recommendation of the National Cancer Institute of Canada Clinical Trials Group Data Safety Monitoring Committee. There were 277 patients enrolled onto the study, 138 in the BAY 12-9566 arm and 139 in the gemcitabine arm. The rates of serious toxicity were low in both arms. The median survival for the BAY 12-9566 arm and the gemcitabine arm was 3.74 months and 6.59 months, respectively (P <.001; stratified log-rank test). The median progression-free survival for the BAY 12-9566 and gemcitabine arms was 1.68 and 3.5 months, respectively (P <.001). Quality-of-life analysis also favored gemcitabine. CONCLUSION: Gemcitabine is significantly superior to BAY 12-9566 in advanced pancreatic cancer.

Adenocarcinoma↗
PubMed2000

Motilin receptors in the human antrum.

Motilin is an intestinal peptide that stimulates contraction of gut smooth muscle. The motilin receptor has not been cloned yet, but motilin-receptor agonists appear to be potent prokinetic agents for the treatment of dysmotility disorders. The aim of this study was to determine neural or muscular localization of motilin receptors in human upper gastrointestinal tract and to investigate their pharmacological characteristics. The binding of (125)I-labeled motilin to tissue membranes prepared from human stomach and duodenum was studied; rabbit tissues were used for comparison. Solutions enriched in neural synaptosomes or in smooth muscle plasma membranes were obtained. Various motilin analogs were used to displace the motilin radioligand from the various tissue membranes. The highest concentration of human motilin receptors was found in the antrum, predominantly in the neural preparation. Human motilin receptors were sensitive to the NH(2)-terminal portion of the motilin molecule, but comparison with rabbit showed that both species had specific affinities for various motilin analogs [i.e., Mot-(1-9), Mot-(1-12), Mot-(1-12) (CH(2)NH)(10-11), and erythromycin]. Motilin receptors obtained from synaptosomes or muscular plasma membranes of human antrum expressed different affinity for two motilin-receptor agonists, Mot-(1-12) and Mot-(1-12) (CH(2)NH)(10-11), suggesting that they correspond to specific receptor subtypes. We conclude that human motilin receptors are located predominantly in nerves of the antral wall, are functionally (and probably structurally) different from those found in other species such as the rabbit, and express specific functional (and probably structural) characteristics dependent on their localization on antral nerves or muscles, suggesting the existence of specific receptor subtypes, potentially of significant physiological or pharmacological relevance.

Animals↗
PubMed2000

A case of giant cell hepatitis recurring after liver transplantation and treated with ribavirin.

A patient who underwent orthotopic liver transplantation for giant cell hepatitis with cirrhosis and in whom giant cell hepatitis recurred twice after orthotopic liver transplantation is reported. He was treated with ribavirin with an excellent result. The literature on this subject is reviewed. This observation clearly confirms the efficacy of ribavirin for the treatment of giant cell hepatitis, thus providing evidence for its viral origin.

Adult↗
PubMed1999

Hypocalcemia induced during major and minor abdominal surgery in humans.

Hypocalcemia has only been rarely reported during surgical procedures not involving massive blood transfusions. The frequent observation in our hospital of a low serum ionized calcium level during surgery in nonacutely ill patients prompted us to investigate the calcium-PTH axis in three groups of subjects undergoing major (hepatectomy; n = 10), moderately severe, or minor surgery under general anesthesia (colectomy; n = 7, herniorrhaphy; n = 9) compared to that in one group of minor surgery cases under epidural anesthesia (herniorrhaphy; n = 15). Serum samples were obtained before anesthesia, after anesthesia but before surgery, and 40 and 120 min after the beginning of surgery in all groups of patients and for up to 3 days in major and moderately severe cases. Significant falls (P < 0.01), always proportional to the severity of the surgical/anesthesia procedure, were observed for ionized calcium (6-20%), total calcium (8-19%), and albumin (8-23%) accompanied by increases in intact PTH (105-635%). The decrease in ionized and total calcium correlated with a decrease in albumin (P < 0.001). Phosphorus, pH, and magnesium levels remained within the normal range. Adjustment of ionized calcium for variation in albumin revealed that 50-100% of the variation in ionized calcium could be attributed to a fall in albumin resulting from fluid administration to patients before admission to the surgery ward and between the onset of anesthesia and the end of surgery (1.2-5.6 L). Albumin- and pH-independent residual ionized calcium decreases of 12.2% in the hepatectomy group, 4.6% in the group of moderately severe and minor cases under general anesthesia, and 3.7% in the control group reflected the severity of the surgical/anesthesia procedure.

Abdomen↗
PubMed1997

Lack of relationship between preoperative measures of the severity of cirrhosis and short-term survival after liver transplantation.

The purpose of this study was to evaluate the prognostic value of clinical measures of the severity of disease in cirrhotic patients who were candidates for liver transplantation at our institution. The records of the 132 cirrhotic patients who were candidates for a first transplantation between January 1, 1987, and December 31, 1994, were reviewed. One hundred nine patients (82.6%) received grafts, and 23 (17.4%) died while on the waiting list. The variables examined included level of medical urgency at the time of enlistment, date of transplantation, serum creatinine level, variables that constitute the Child-Pugh score and Shaw's risk score (serum bilirubin and albumin, prothrombin time, ascites, encephalopathy, nutritional status, age, and operative blood loss), and 6-month survival status after transplantation. The proportion of patients who died awaiting a graft increased as a function of the Child-Pugh score at enlistment (score 5-6, 0%, n = 6; score 7-9, 7%, n = 54; score 10-11, 18%, n = 33; score 12-15, 33%, n = 39; P = .01). Six-month survival rates after transplantation were similar irrespective of the Child-Pugh score or Shaw's risk score. Stepwise multiple logistic regression models identified the degree of ascites, serum bilirubin, and operative blood loss as significant variables for the prediction of overall mortality 6 months posttransplantation (model chi 2 = 12.8; P = .025; r = 0.32), but the model explained only 10% of the outcomes observed. We concluded that the Child-Pugh score is a valid prognostic index for survival up to the time of transplantation for cirrhotic patients on the waiting list; however, clinical measures of the severity of cirrhosis are poor predictors of 6-month survival after transplantation.

Adolescent↗
PubMed1997

Linear tomography's clinical accuracy and validity for presurgical dental implant analysis.

Accurate assessment of alveolar ridge morphology and inferior alveolar canal location is critical in the presurgical planning phase for dental implant therapy. This study examined the accuracy and validity of linear tomography in the presurgical assessment of potential mandibular implant sites. Seven subjects (six oral and maxillofacial surgeons and one oral radiologist) traced the mandibular cortical bone and inferior alveolar canal on linear tomographic images taken from five mandibles on five separate occasions over 5 weeks. Tracings and the sectioned mandibles were scanned into a computer and assessed for eight measurement criteria. Statistically significant findings were present for intraobserver variability, interobserver variability, and differences between the perceived and actual anatomic structures within the assessed plane of section. These findings demonstrate that the inherent dimensional instability of linear tomography severely limits its diagnostic and clinical role in preoperative implant site assessment.

Alveolar Process↗
PubMed1997

Left hepaticogastrostomy for biliary obstruction: long-term results.

PURPOSE: To evaluate the long-term results of peripheral biliary diversion by means of anastomoses of the left lobe of the liver to the stomach. MATERIALS AND METHODS: Transhepatic perforation of the left lobe of the liver into the lesser curvature of the stomach was performed in 35 patients with a presumed diagnosis of malignant obstructive jaundice. Jaundice was found to be caused by a malignant stricture in 32 patients and a benign stricture in three. Perforation was performed under fluoroscopic, endoscopic, and laparoscopic guidance in 33 patients and without laparoscopy in the other two. The hepaticogastric anastomosis was secured with a gastrostomy tube; patency of the tract was maintained with placement of a metallic stent. Kaplan-Meier analysis was used to evaluate survival, anastomosis patency rate, and jaundice recurrence. RESULTS: Technical success was achieved in all patients. Two (6%) patients had anastomotic obstruction. The actuarial survival rate was 91%, 80%, 59%, and 26% at 1, 3, 6, and 12 months. The mean patency was 234 days +/- 252. The jaundice-free rate among surviving patients was 100%, 96%, 93%, and 80% at 1, 3, 6, and 12 months. The reintervention rate was 14%. Late cholangitis occurred in seven (20%) patients. CONCLUSION: This peripheral diversion procedure appears to be safe and shows good long-term patency.

Adult↗
PubMed1996

The hepatic microcirculation in the isolated perfused human liver.

In cirrhosis, capillarization of sinusoids could result in impaired exchanges between the hepatocytes and the blood perfusing the liver and contribute to liver failure irrespective of the metabolic capacity of the liver. To characterize anomalies of the hepatic microcirculation, we used the multiple-indicator dilution approach in isolated perfused livers obtained from patients with cirrhosis at the time of transplantation, and from organ donors with normal or near-normal livers or hepatic steatosis. In organ donors, the sinusoidal volume and the permeability of sinusoids to albumin, sucrose, and water were found to be comparable to that of normal dog and rat livers. The sinusoidal volume and the extravascular volume (EVV) accessible to diffusible tracers were larger after hepatic artery than after portal vein injection, probably because of an unshared arterial sinusoidal bed. In cirrhotic livers, two kinds of alterations were found: the appearance of a barrier between the sinusoids and the hepatocytes (capillarization) and intrahepatic shunts. The extravascular space accessible to albumin decreased with increasing severity of cirrhosis, and the diffusion of sucrose in the space of Disse showed a barrier-limited pattern, instead of the normal flow-limited behavior. In cirrhotic livers, a correlation was found between the hepatic extraction of indocyanine green (ICG) and the extravascular space accessible to albumin (r = .84, P < .05), suggesting that the impaired access of this protein-bound dye to the hepatocyte surface contributed to its impaired elimination. Intrahepatic shunts were found between portal and hepatic vein (21% +/- 16% of portal flow), but not between hepatic artery and hepatic veins. We conclude that (1) the behavior of diffusible tracers in human livers with normal liver architecture is comparable to that reported in normal animals; (2) the permeability of sinusoids in cirrhotic livers is abnormal, (3) permeability changes are related to changes in liver function in cirrhosis.

Adolescent↗
PubMed1996

[Reduction of blood loss in orthotopic liver transplantation with the use of aprotinin].

UNLABELLED: The impact of aprotinin on blood losses during orthotopic liver transplantation (OLT) has been studied retrospectively. PATIENTS AND METHODS: From September 1984 to July 1995, 152 patients underwent 168 OLT in our center. Seventy three patients (group I) received epsilon-aminocaproic acid as an antifibrinolytic agent and 95 patients (group II) received aprotinin. RESULTS: There was a significant reduction in the mean duration of the surgery (I = 743 +/- 25 min; II = 302 +/- 10 min; p < 0.001) and in the post reperfusion time (I = 282 +/- 13 min; II = 126 +/- 6 min; p < 0.001) in the group II. The need for blood products during the operation was also reduced (blood units; I = 21.7 +/- 2.3 units; II = 4.6 +/- 0.4 units; p < 0.001). There was less infectious and hemorrhagic complications requiring reoperation in group II. We have not seen an increased incidence of thrombotic complications in the patients receiving aprotinin. Other variables such as the use of hemoclips, veno-venous bypass and the type of preservation solution were also considered. CONCLUSION: Aprotinin use during OLT is efficient and superior to epsilon-aminocaproic acid in reducing blood losses. Combined with the non-utilisation of a veno-venous by-pass and the use of hemoclips, it helps reduce the operating time and the postoperative complications.

Adult↗
PubMed1996

Clearance by the liver in cirrhosis. III. Propranolol uptake by the isolated perfused human liver.

In cirrhosis, intrahepatic shunts and capillarization of sinusoids can result in impaired extraction of substrates by the liver irrespective of the metabolic capacity of the liver (intact hepatocyte theory). To evaluate the role of anomalies of uptake in impaired drug disposition, we studied the steady-state hepatic clearance and single-pass hepatic uptake of propranolol in isolated perfused livers obtained from patients with cirrhosis at the time of transplantation and from organ donors with normal liver architecture. The kinetics of propranolol transport in the liver were characterized by means of the multiple-indicator dilution technique, and the outflow pattern of propranolol in the hepatic veins was resolved into throughput material, which had swept past the hepatocytes along with albumin, and returning material, which had entered the cells but returned in the outflow after escaping cellular sequestration and metabolism. The steady-state clearance of propranolol was decreased in cirrhotics compared with organ donors, and the outflow profile differed between the two groups. In cirrhotic livers, half of the propranolol in the outflow consisted of throughput material and the other half of returning material; in organ donors, all of the propranolol in the outflow was returning material. In the presence of albumin and alpha 1-acid glycoprotein in the perfusate, about 80-85% of propranolol was protein bound; removal of albumin and alpha 1-acid glycoprotein from the perfusate it cirrhotic livers resulted in an increase in the free fraction of propranolol, an increase in steady-state extraction, and a decrease in the throughput component of propranolol in the outflow. We conclude that impaired uptake of protein-bound propranolol, as a result of capillarization and intrahepatic shunts, contributes to its impaired elimination in cirrhosis.

Biological Transport↗
PubMed1995

Cold ischemia-reperfusion injury of the liver. Role of the liver donor nutritional status in rats.

To verify the role of donor nutritional status on the quality of liver preservation after cold storage, we assessed hepatocyte and liver endothelial cell viabilities and functions in an isolated perfused rat liver model. Livers from fed and fasted Wistar rats were isolated and perfused either immediately after liver harvesting or after a 24-hr cold (4 degrees C) preservation in University of Wisconsin solution. Hyaluronic acid (150 ng/ml) and taurocholate (11.5 micrograms/ml) were infused into the reservoir, and their eliminations were assessed to evaluate liver endothelial cell function and hepatocyte function, respectively. Liver viability was estimated by intrahepatic resistance, oxygen consumption, bile secretion, and lactate dehydrogenase release. In addition, cell viabilities were evaluated by trypan blue staining. In fed-rat livers, glycogen content did not differ before or after the cold preservation, although a reduction was observed during the subsequent perfusion period. Liver glycogen content in fed rats was markedly higher than in the fasted rats at each time point studied. In fasted and fed rats, liver viability parameters and hepatocyte function were moderately altered, whereas liver endothelial cell function was markedly impaired after cold preservation. However, feeding had no influence on either hepatocyte or liver endothelial cell functions which were similarly altered in both nutritional conditions. The present data show that the nutritional status of liver donors does not play an important role in the preservation of liver endothelial cells after cold ischemia-reperfusion and, thus, should not affect the overall resistance of livers to hypothermic-ischemic injury.

Adenosine↗
PubMed1995

[Role of extracorporeal shock wave lithotripsy in the treatment of common bile duct and intrahepatic calculi].

The management of intrahepatic and common bile duct stones has been modified by the advent of endoscopic sphincterotomy and percutaneous extraction through a T-tube tract or transhepatic access. Occasionally, nonoperative extraction is incomplete. The use of extracorporeal lithotripsy is reviewed in this setting. From May 1990 to February 1994, 18 patients (age 68.4 +/- 4.6 years) were treated by extracorporeal shockwave lithotripsy combined with endoscopic sphincterotomy and retrograde extraction or percutaneous approach. 72% of patients had previously undergone a cholecystectomy and 44% exploration of the common duct. Patients were submitted to 1.56 +/- 0.17 session of lithotripsy (5.546 +/- 701 shockwaves). Hospital stay was 19.5 +/- 3.3 days. After the lithotripsy, 1.17 +/- 0.19 endoscopic or percutaneous procedures per patient were necessary to clear the biliary tract. Seventy-eight percent of patients became stone-free. The five failures were treated by endobiliary prosthesis (n = 4) or cholecystectomy and bile duct exploration (n = 1). Lithotripsy in association with the usual therapeutic modalities contributes to clearing the bile duct from stones and avoids surgery in the majority of patients. A multidisciplinary approach is necessary in order to obtain those results.

Aged↗
PubMed1994

Iatrogenic injury to the bile duct: a working classification for radiologists.

PURPOSE: To assess the usefulness of the Bismuth classification method in the preoperative localization of iatrogenic bile duct lesions with cholangiography and to correlate these cholangiographic findings with surgical findings. MATERIALS AND METHODS: The records of 33 patients who underwent open or laparoscopic cholecystectomy and who sustained injuries to the biliary tract during the course of these procedures were reviewed retrospectively. The accuracy of the cholangiographic localization of bile duct injury was assessed with the Bismuth classification method, which is based on the localization of the traumatic lesion according to the distance from the biliary confluence. RESULTS: An exact correspondence between cholangiographic and surgical findings was found in 85% of the subjects. A minimal discrepancy was found in the remainder. There was no interobserver variation. CONCLUSION: The use of the Bismuth classification method appears to be an accurate and practical method for the grading of postoperative bile duct lesions with cholangiography.

Bile Ducts↗
PubMed1994

Postoperative changes, complications, and recurrent disease after Whipple's operation: CT features.

Whipple's operation consists of resection of the pancreatic head and duodenum, followed by pancreaticojejunostomy, choledochojejunostomy, and gastrojejunostomy or duodenojejunostomy. Indications include neoplasms of the periampullary region, symptomatic chronic pancreatitis, and, occasionally, trauma CT is useful in diagnosing postoperative complications and in detecting disease recurrence during long-term follow-up. This complex surgical procedure causes alterations of the normal anatomy, which may lead to difficulty interpreting images. Familiarity with the appearance of postoperative changes and common complications and with patterns of disease recurrence is a prerequisite to accurate interpretation of CT scans in these patients.

Choledochostomy↗
PubMed1994

[Experience with the transjugular intrahepatic portocaval shunt].

Liver transplantation and the intrahepatic shunt have changed the management of variceal hemorrhage and refractory ascites. The purpose of this work is to review the results obtained with intrahepatic shunting. From January 1991 to May 1993, 45 patients underwent a transjugular intrahepatic portosystemic shunt. In 23 patients, liver insufficiency was considered moderate and in 21 severe. Indications for the procedure were: variceal bleeding (23), refractory ascites (19) and portal hypertensive gastritis (3). The portocaval gradient was lowered from 24.2 +/- 5.1 mm Hg to 12.9 +/- 3.9 (-47%). The procedure was effective in 78% of variceal bleeders and in 89% of patients with ascites. Thirty-day mortality was 22%. One-year survival was 39%. Liver failure or severe encephalopathy occurred in 27% of patients. Four patients (9%) presented intra-abdominal bleeding. Four patients developed renal failure. Transjugular intrahepatic portosystemic shunts are effective in lowering portal pressure and controlling complications of portal hypertension. However, important side effects are present and controlled studies are required to evaluate this new treatment.

Aged↗
PubMed1994

[Cystic tumors of the pancreas: apropos of 36 cases].

Cystadenomas and cystadenocarcinomas are rare cystic tumors of pancreas. Clinicopathological features and treatment of these neoplasms have been studied in 36 patients over a 10-year period (1983-1993). There were 19 cystadenomas (CA) either serous (n = 13) or mucinous (n = 6) and 17 cystadenocarcinomas (CAC). Eighteen CA (95%) were found in women. CAC were found equally between both sexes. Median age was 63 years and was the same for CA and CAC. Ultrasound gave correct diagnosis of CA or CAC in 64% and CT-scan in 77%. The majority of CAC (n = 15) were localized in the head of the pancreas. CA had no preferential localization. 24 patients (66%) underwent including resection (n = 20) and biopsy (n = 4). Four other patients had a percutaneous biopsy and 8 were observed. Hospital mortality was 8%. Complications included gastric atony (n = 4) and pancreatic fistula (n = 2). Four-year actuarial survival is 63% for resected CAC and 100% for resected CA. In conclusion, most cystic pancreatic tumors are found in women. Malignant lesions are found predominately in the head of the pancreas. Modern imaging technics combined with clinical presentation are reliable in obtaining a diagnosis. Resection remains the treatment of choice.

Adult↗