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Biomedical subjects

M Potvin

Publications and source records attributed to M Potvin.

At least 37 records · Page 2Linked to original sources
PubMed1991

Biliopancreatic Diversion with Gastrectomy as Surgical Treatment of Morbid Obesity.

The best procedure for the treatment of morbid obesity has not yet been defined. Biliopancreatic diversion is one of the techniques available, but its results have not been sufficiently documented and the addition of a subtotal gastrectomy to the diversion so as to avoid leaving a blind non-functioning stomach, is still questionable. The purpose of this paper is to report our experience with our first 149 consecutive patients who were treated by biliopancreatic diversion with subtotal gastrectomy for morbid obesity. Operative mortality was 3% and morbidity 12%. The weight loss was marked during the first 6 months and decreased during the following 12 months. The weight stabilized at 2 years and there was subsequently a small increase. In only two out of 48 cases was the weight loss less than 25% of the initial weight at 2 years. The undesirable side-effects were diarrhea in 6%, vomiting in 9% and dyspepsia in 4%. The intervention leads to a malabsorption of carotene, iron, albumin and calcium. Except for carotene the deficiencies were corrected by oral supplement. In two patients, with resistant deficiencies, the diversion was reversed. Eighty-eight percent of the patients are satisfied with this intervention. At 2 years, 70% have reached their weight loss objective without any major side-effects or nutritional deficiencies, but in 14% the outcome of the procedure must be considered unsatisfactory. Biliopancreatic diversion with subtotal gastrectomy is a major operation, but it gives encouraging results so far.

Journal Article↗
PubMed1990

Adjuvant therapy of Dukes' A, B, and C adenocarcinoma of the colon with portal-vein fluorouracil hepatic infusion: preliminary results of National Surgical Adjuvant Breast and Bowel Project Protocol C-02.

Between March 1984 and July 1988, 1,158 patients with Dukes' A, B, and C carcinoma of the colon were entered into National Surgical Adjuvant Breast and Bowel Project (NSABP) Protocol C-02. Patients were randomized to either no further treatment following curative resection or to postoperative fluorouracil (5-FU) and heparin administered via the portal vein. Therapy began on day of operation and consisted of constant infusion for 7 successive day. Average time on study was 41.8 months. A comparison between the two groups of patients indicated both an improvement in disease-free survival (74% v 64% at 4 years, overall P = .02) and a survival advantage (81% v 73% at 4 years, overall P = .07) in favor of the chemotherapy-treated group. When compared with the treated group, patients who received no further treatment had 1.26 times the risk of developing a treatment failure and 1.25 times the likelihood of dying after 4 years. Particularly significant was the failure to demonstrate an advantage from 5-FU in decreasing the incidence of hepatic metastases. The liver was the first site of treatment failure in 32.9% of 82 patients with documented recurrences in the control group and in 46.3% of 67 patients who received additional treatment. Therapy is administered via a regional route to affect the incidence of recurrence within the perfused anatomic boundary. Since, in this study, adjuvant portal-vein 5-FU infusion failed to reduce the incidence of hepatic metastases, it may be concluded that its use thus far is not justified. It may also be speculated that the disease-free survival and survival advantages (the latter of borderline significance) are a result of the systemic effects of 5-FU.

Adenocarcinoma↗
PubMed1987

Biological conversion of benzaldehyde to benzylmercapturic acid in the Sprague-Dawley rat.

The metabolism of benzaldehyde was investigated in Sprague-Dawley rats. After repeated oral administration of this compound (0.4-1.0 g/kg) for 13 consecutive days, urine was collected and analyzed for the presence of metabolites. The acidification of the pooled urine samples (pH:2.0) with 6 N H2SO4 was followed by ethyl acetate extraction, evaporation of the extract and methylation with diazomethane. Identification of the metabolite by comparison with a synthetic sample of benzylmercapturic acid (BENZM) was conducted by gas chromatography. Mass spectrometry examination of this metabolite revealed the following peaks characteristic of benzylmercapturic acid: m/z (%), 91(100), 176(27), 208(23), 43(20), 88(13), 117(10), 134(9), M+ 267(2). Monitoring of urines from both female and male rats showed a dose-related increase of benzylmercapturic acid which was found to be a reliable indicator of exposure to benzaldehyde.

Acetylcysteine↗
PubMed1986

Clinical experience with biliopancreatic bypass and gastrectomy or selective vagotomy for morbid obesity.

In 1980 Scopinaro described biliopancreatic bypass for the treatment of obesity. This procedure was aimed at selective malabsorption. The authors used Scopinaro's procedure in 33 patients, but in 17 they modified it by doing selective vagotomy with closure of the duodenum in continuity instead of a subtotal gastrectomy. Eighteen months after the operation, 88% of the patients had what the authors considered was a good to excellent result, that is a loss of more than 25% of the patient's initial weight. Morbidity of many kinds was encountered but most was self-limiting or easily corrected by medical means. From their experience the authors conclude that biliopancreatic bypass as a procedure for the treatment of morbid obesity should continue to be performed and evaluated.

Adult↗
PubMed1986

Long-term results of hyperselective vagotomy for duodenal ulcer.

Although considered by many as the operation of choice in the treatment of duodenal ulcer, hyperselective vagotomy without drainage is not unanimously accepted because little is known about its long-term efficiency in preventing ulcer recurrence. The long-term results of 203 patients with duodenal ulcer, treated by hyperselective vagotomy between 1974 and 1983 at the Hôpital Laval, are reported. Patients were followed at yearly intervals and questionnaires were used to determine whatever benefits they perceived. The procedure was found to be a safe one with an uncomplicated postoperative course. The overall recurrence rate was 12% over a mean follow-up of 64 months. Recurrences may occur 5 or more years after surgery. The operative technique is important in preventing recurrence. Dissection of the last 6 cm of esophagus lowered the recurrence rate at 5 years from 21% to 9%. Only four patients required reoperation. The majority of recurrences consisted of a single episode, the ulcer being easily controlled by short-course medical treatment. The authors found that 94% of patients were satisfied with the results of the operation.

Adult↗
PubMed1984

Short-term antibiotherapy for peritonitis: prospective, randomized trial comparing cefotaxime-metronidazole and clindamycin-tobramycin.

The combination of cefotaxime and metronidazole has been suggested for the treatment of peritonitis. We compared their effectiveness with that of tobramycin and clindamycin. Since antibiotics have most of their beneficial effect within a few days a four day course was used and a randomized trial was undertaken. The effectiveness of the 4-day course was 86% and no difference was seen between the two groups of the study.

Cefotaxime↗
PubMed1984

Cerebral abnormalities in hepatectomized rats with acute hepatic coma.

When hepatectomized rats develop hepatic coma, they are found to have cerebral edema, together with a failure of the blood-brain barrier to contain materials usually limited to the circulation. The present studies were carried out to characterize the associated ultrastructural changes in the barrier. Rats were allowed to develop hepatic coma after a two-stage hepatectomy. Electrocortical and behavior monitoring during this period indicated deterioration similar to that seen in man with acute liver injury; the water contents of the brains of the animals in hepatic coma were increased. Electron microscopic examination of the brains from control rats and animals with hepatic coma were carried out after perfusion fixation. The examination of the brains from the comatose animals showed the appearance of greatly increased numbers of vesicles in the capillary endothelium and a marked watery swelling of adjacent astrocytes, which seemed to begin in foot processes and then to spread through the cell. Intravenous peroxidase was given to most rats in the late stages of coma, and the tracer was found to be included within the capillary endothelial vesicles. Occasional accumulations of peroxidase in the underlying capillary basement membrane were found. No interendothelial cell distruption was found. Low molecular weight microperoxidase was used as well as horseradish peroxidase; the results were the same with both compounds. The findings indicate as association between capillary endothelial vesicle formation and the cerebral edema found in animals with hepatic coma following hepatectomy.

Animals↗
PubMed1983

Biological conversion of N-phenyl-2-naphthylamine to 2-naphthylamine in the Sprague-Dawley rat.

The metabolism of a widely used plastic and rubber antioxidant, N-Phenyl-2-Naphthylamine, was investigated in Sprague-Dawley rats. After repeated oral administration of this compound, urine and feces were collected for several days and analyzed for the presence of metabolites. Identification techniques included a preliminary clean-up followed by thin-layer chromatography of amines and gas chromatography-mass spectrometry of their hexafluoroacyl derivatives (HFBA). The compounds identified in both urine and feces were characterized as N-Phenyl-2-Naphthylamine (PBNA) and 2-Naphthylamine (BNA). Data obtained on urinary excretion of BNA seem to indicate that repeated administration of PBNA enhances its own metabolism.

2-Naphthylamine↗
PubMed1980

Acidic metabolites of pseudocumene in rabbit urine.

In order to identify biological indicators of exposure to trimethylbenzenes, the metabolism of pseudocumene (1,2,4-trimethylbenzene) was investigated in rabbits. After oral administration of this compound, urine was collected for several days and analyzed for the presence of acidic metabolites. Isolation techniques included steam-distillation, direct extraction of urine by ethyl acetate, preparative thin-layer and column chromatography of the extract. The metabolites were identified by microanalysis, followed by TLC, gas chromatography-mass spectrometry, infrared and ultraviolet spectroscopy. Two major urinary metabolites were identified namely 2,4-dimethylbenzoic acid and 3,4-dimethylhippuric acid. The presence of these acidic metabolites in urine is a good indication of exposure to pseudocumene.

Animals↗
PubMed1980

Studies on inhalation toxicity of 2-propanol.

Biological effects of a single exposure to moderate or high concentrations of 2-propanol were investigated in Sprague-Dawley rats. Acute toxicity (LC50, t:8 hours) of this widely used solvent was determined and found to be 19000 ppm (17380-20760 ppm) for females and 22500 ppm (19200-26400 ppm) for males. Determination of blood levels of 2-propanol and its metabolite, acetone, was carried out during and after a single 4-hour exposure (Concentration range: 500 to 8000 ppm). The amount of acetone and 2-propanol was directly related to the various air concentrations of alcohol inhaled. Increase of exposure time to 8 hours enhanced considerably the amount of blood acetone which could be determined even 20 hours after exposure. These findings indicate a slow conversion of this alcohol to acetone which can be used as biochemical indicator to exposure. Histopathological examination of rats exposed to high levels of 2-propanol shows typical lesions of chemical pneumonitis and pulmonary edema accompanied by foamy vacuolization of liver cells and severe focal cytoplasmic degradation.

1-Propanol↗
PubMed1978

[Toxicological studies on dichloromethane, a solvent simulating carbon monoxide poisoning (author's transl)].

Acute oral and inhalation toxicity of dichloromethane was investigated in both male and female Sprague-Dawley rats. Oral LD50 was found to be 1.72 ml/kg for males and 1.06 ml/kg for females. LC50 was found to be 18 100 PPM (1 X 6 hours) for both male and female rats. Acute oral intoxication is characterized by severe vascular changes and depression of the central nervous system accompanied by gastro-intestinal hemorrhagy. A similar CNS depression is also found in acute intoxication by inhalation. The nature of the symptoms as well as the sequence of physiological (hypotension, hypothermia) and biochemical events observed (high COHb level, etc.) indicate that the combined action of dichloromethane and its metabolite, carbon monoxide, are responsible for the development of vascular and CNS disturbances and subsequently the sudden death of the animals.

Administration, Oral↗