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Biomedical subjects

M Gagner

Publications and source records attributed to M Gagner.

118 records · Page 7Linked to original sources
PubMed1989

The effect of Escherichia coli endotoxin on the adrenergic control of lipolysis in the human adipocyte.

We investigated the effect of Escherichia coli O127:B8 endotoxins on the adrenergic control of lipolysis in the human adipocyte. Adipose tissue was incubated in vitro with isoproterenol to stimulate the beta-1 receptors, clonidine to stimulate the alpha-2 receptors, and theophylline to stimulate the subreceptor mechanism. Using a dual radioisotope technique, a lipolysis factor was calculated for each sample. The basal lipolysis factor was significantly (P less than 0.006) decreased 31% with endotoxin. beta-1 adrenergic receptor stimulation (isoproterenol, 1 X 10(-8) to 1 X 10(-4) M) was significantly decreased an average of 31% with E. coli endotoxin. The beta-1 receptor responsiveness was also significantly (P less than 0.02) decreased but not the receptor sensitivity. This indicated an alteration in the post beta receptor mechanism. The various components of the post beta-1 adrenergic mechanism were stimulated including the beta-1 receptor, the G protein, adenylase cyclase, and the lipase phosphorylase. The results indicated a significant 24.2% reduction of the beta-1 receptor and a 25.4% reduction in G protein stimulation. Thus the E. coli endotoxin effect on the beta adrenergic mechanism is at the G protein. The endotoxin had no effect on the alpha-2 receptor stimulation nor the theophylline stimulation of the subreceptor lipolysis. This study indicates that E. coli endotoxin (O127:B8) decreases in vitro beta adrenergic stimulation of human adipocyte lipolysis, and this effect can be partially reversed by theophylline.

Adipose Tissue↗
PubMed1986

The effect of interleukin-1 and interleukin-2 on the adrenergic control of hormone-sensitive lipase in the human adipocyte.

The effect of interleukin-1 and interleukin-2 on lipolysis and the adrenergic control of lipolysis was studied. Biopsy specimens of human adipose tissue were incubated in media containing 3H-palmitate and 14C-glucose, and the ratio of these isotopes was used to determine adipocyte lipolysis. Isoproterenol, clonidine, and theophylline were used in the media to stimulate the beta 1- and alpha 2-receptors and the subreceptor mechanism, respectively. Interleukin-1 had no effect on basal lipolysis, and at maximal receptor stimulation, it had no effect on the adrenergic receptor control of lipolysis. Interleukin-2 had no effect on basal lipolysis or on the beta-adrenergic receptor. Interleukin-2 significantly (p less than 0.02) decreased the alpha 2-inhibition of lipolysis by 68%. The effect of interleukin-2 on the alpha-receptor was demonstrated to be a significant 45% decrease (p less than 0.03) in the receptor responsiveness (a measure of the postreceptor mechanism) with no alteration in receptor sensitivity (a measure of receptor number). This data suggest that interleukin-2 stimulates lipolysis by decreasing the alpha 2-adrenergic inhibition of hormone-sensitive lipase.

Adipose Tissue↗
PubMedDate not supplied

Laparoscopic cryoablation of hepatic metastases.

Cryosurgery for liver metastases may improve survival for unresectable hepatic metastases. The laparoscopic approach to managing these tumors is a novel method fostered by increasing surgeon and patient interest in minimally invasive surgical techniques and the development of laparoscopic ultrasound and cryoprobes. A retrospective review of our patients who underwent laparoscopic cryoablation of hepatic tumors from April 1996 to December 1997 was conducted. We report on this experience and comment on the feasibility and safety of the procedure based on this early trial.

Cryosurgery↗
PubMedDate not supplied

Radical operations for carcinoma of the gallbladder: present status in North America.

Experience in the United States of America with the use of radical operations for carcinoma of the gallbladder was reviewed. Four studies using the Nevin clinicopathologic classification were combined for analysis. The 5-year survival rate for patients with stage I disease was 59%; stage II disease, 40%; stage III disease, 9%; stage IV disease, 7%; and stage V disease, 1%. Only one study analyzed the results of surgical procedures according to Nevin staging. No conclusions can be drawn from retrospective studies on the value of operations more radical than simple cholecystectomy. Responses to a questionnaire sent to prominent North American surgeons emphasized the controversial management of patients with this disease.

Gallbladder Neoplasms↗
PubMedDate not supplied

Laparoscopic pancreatic resection: Is it worthwhile?

A series of 23 patients who had undergone an attempted laparoscopic Whipple (n = 10) or laparoscopic distal pancreatectomy (n = 9) or laparoscopic enucleation (n = 4) since January 1992 were retrospectively reviewed. In the laparoscopic Whipple group (6 women and 4 men; mean age 71 [range 33 to 82] years), eight had malignant periampullary tumors and two had chronic pancreatitis. The rate of conversion to an open procedure was 40%, and complications were seen in the nonconverted group. The average operative time was 8.5 hours, and the hospital stay was 22.3 days. However, in the laparoscopic distal pancreatectomy and enucleation groups, there were seven women and six men (mean age 46.5 [range 27 to 75] years). Of these, nine patients had a planned laparoscopic distal pancreatectomy (8 for islet cell tumors and 1 for chronic pancreatitis) and four had a planned laparoscopic enucleation (all 4 for islet cell tumors). The conversion rate for these patients was 36%, and the mean operative time was 4.5 hours for laparoscopic distal pancreatectomy and 3 hours for laparoscopic enucleation. The hospital stay was 5 days and 4 days, respectively. Although this series was small, no benefit seemed to be derived from the use of a complete laparoscopic Whipple procedure. Laparoscopic distal pancreatectomy and enucleation were technically easier to perform and seemed to benefit patients by shortening their hospital stay with no recurrence of disease.

Adult↗
PubMedDate not supplied

Trends in bile duct injuries from laparoscopic cholecystectomy.

Bile duct injuries are a serious complication of cholecystectomy. Laparoscopic cholecystectomies (LC) were originally associated with an increased incidence of injuries. Patients referred to a tertiary center were reviewed to assess the trends in the number, presentation, and management. Seventy-three patients were referred over a 6-year period with a maximum of 17 patients referred in 1992, but the number has not declined substantially over time. The persistent number of referrals is a consequence of ongoing injuries. One third of injuries were diagnosed at LC, and the use of cholangiography has not increased. The number of cystic duct leaks has not decreased and they represent 25% of all cases. The level of injury has remained unchanged with Bismuth types I and II in 37% and types III and IV in 38%. Excluding patients with cystic duct leaks, 58% were referred after a failed ductal repair. Definitive treatment with biliary stenting was successful in 37%, and 34 patients (47%) required a biliary-enteric anastomosis. Complications occurred in 18 patients (25%) including seven with postoperative stricture or cholangitis. No biliary reoperations have been performed at a mean follow-up of 36 months.

Acute Disease↗
PubMedDate not supplied

Laparoscopic pancreatic resection.

The extent of reported laparoscopic resections vary from enucleation to pancreaticoduodenectomy. Although initial series have been reported with encouraging results, most patients with pancreatic disease requiring resection are still treated with an open approach. We present a review of our experience and of the world literature on laparoscopic pancreatic resection. Laparoscopic pancreaticoduodenectomy has been attempted in 12 patients with a conversion rate of 33%. Complications occurred in the laparoscopic group. The laparoscopic patients have experienced no benefit in the postoperative recovery and convalescence. Early experience with the hand-assisted approach is promising. Sixty-eight laparoscopic distal pancreatectomies and enucleations have been reported to date. They were 42 distal pancreatectomies and 26 enucleations. Thirteen procedures have been converted to open surgery (19.1%). There was no mortality and the main postoperative complication was pancreatic leak (5 patients, 7.3%). Average hospital stay was 9 days. These results compare favorably with the outcomes after open pancreatic resection. While laparoscopic pancreaticoduodenectomy is not associated with patient benefit and may be accompanied by increased morbidity, laparoscopic distal pancreatectomy and enucleation are safe, carry low morbidity and have encouraging results in terms of postoperative recovery.

Humans↗