Search PubMed⌕ Search

Biomedical subjects

J B Hanks

Publications and source records attributed to J B Hanks.

At least 37 records · Page 2Linked to original sources
PubMed1992

Pancreas transplantation. An initial experience with systemic and portal drainage of pancreatic allografts.

Pancreas transplantation has evolved dramatically since its introduction in 1966. As new centers for transplantation have developed, the evaluation of complications associated with pancreas transplantation has led to advances in surgical technique. Furthermore, surgical alterations of the pancreas resulting from transplantation (systemic release of insulin and denervation) are of unproven consequence on glucose metabolism. Since 1988, the authors have performed 21 transplants (16 combined pancreas/kidney, 3 pancreas alone, which includes 1 retransplantation, 1 pancreas after previous kidney transplant, and 1 "cluster") in 20 patients aged 18 to 49 years; mean, 35 +/- 1 years. Overall patient survival is 95%. Three pancreatic grafts failed within the first year because of technical failure; one additional pancreas was lost to an immunologic event on postoperative day 449, for an overall pancreatic graft survival of 81%. No renal grafts were lost. To evaluate causes of graft failure, demographic data were compared, which included age and sex of the donor and the recipient, operative time, intraoperative blood transfusion, and ischemic time of the graft. No statistically significant differences were found between groups except for ischemic time (11.7 +/- 6.4 hours for the technical success group versus 19.8 +/- 3.7 hours for the technical failure group; p less than 0.05 by unpaired Student's t test). Quadruple immunosuppression was used, which included prednisone, cyclosporine, azathioprine, and antilymphoblast globulin. A mean of 1.2 (range, 0 to 3) rejection episodes per patient occurred. Mean hospital stay was 24 +/- 11 days. Surgical and infectious complications were evaluated by comparing the technical success (TS) group (n = 17) with the technical failure (TF) group. Surgical complications in the TS group revealed a mean of 1.3 episodes per patient, whereas the TF group had 3.7 episodes per patient. The TS also had a reduced incidence of infectious complications compared with the TF (1.7 versus 4.3 episodes per patient). Cytomegalovirus was common in both groups, accounting for 11 infectious episodes, and occurred on a mean postoperative day of 38. Mean postoperative HbA1C levels dropped to 5 +/- 1% from 11 +/- 3%. The authors developed a new technique that incorporates portal drainage of the pancreatic venous effluent in three recipients. Preoperative metabolic studies disclosed a mean fasting glucose of 211 +/- 27 mg/dL and a mean stimulated glucose value of 434 +/- 41 mg/dL for all patients; the mean fasting insulin was 23 +/- 4 microU/mL.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1992

Laparoscopic cholecystectomy in the obese patient.

The authors' experience with laparoscopic cholecystectomy (LC) in obese (O, n = 96) and morbidly obese (MO, n = 27) patient groups was compared with that in the normal weight (NW, n = 174) group of patients as well as the whole group (WG). There were no operative deaths. There were no significant differences between groups for any of the following: successful intraoperative cholangiography (WG, 52.2%; NW, 52.9%; O, 51.1%; MO, 55.6%), conversion to open cholecystectomy (WG, 9.6%; NW, 9.2%; O, 10.4%; MO, 11.1%), incidence of major complications (WG, 4.1%; NW, 3.4%, O, 5.2%; MO, 0%), incidence of minor complications (WG, 7.4%, NW, 7.5%; O, 6.3%; MO, 3.7%), and length of hospitalization after successful LC (WG, 1.25 days; NW, 1.31 days; O, 1.16 days; MO, 1.13 days). Duration of operation did not differ except LC in the MO group (136.4 +/- 6.9 minutes) was longer when compared with NW patients (123.0 +/- 2.9 minutes, p less than 0.05). The authors conclude LC is a safe and effective treatment for obese patients with symptomatic cholelithiasis.

Adult↗
PubMed1991

Glipizide treatment of pancreas autotransplantation: effects on alterations in glucose-insulin relationships.

Pancreas transplantation has been proven effective in supplying an endogenous insulin supply in diabetics. However, alterations in glucose metabolism after transplantation suggest a possible "insensitivity" to its action in the periphery. We hypothesized that sulfonylurea treatment of canines who had received segmental pancreas autotransplants would correct these alterations by altering peripheral insulin sensitivity. Glipizide therapy (5 mg p.o. b.i.d.) did appear, in fact, to enhance basal insulin sensitivity by lowering fasting glucose (100 +/- 3 to 81 +/- 11 mg/dl pre-treatment to post-treatment) while not affecting basal insulin levels. However, glipizide therapy was associated with decreased insulin response to challenge by either oral glucose (2 gm/kg) or sustained intravenous hyperglycemia (150 mg/dl above basal). We conclude that our model of pancreas autotransplantation documents alterations in glucose metabolism which are devoid of the effect of immunosuppression. Glipizide treatment appears to affect fasting sensitivity to insulin, but results in a decrement of insulin response to oral or intravenous glucose challenge.

Animals↗
PubMed1991

Glucose metabolism after pancreas autotransplantation. The effect of open duct versus urinary bladder drainage technique.

Glucose metabolism and insulin secretion after pancreas transplantation may be affected by the technique used for ductal drainage. We evaluated peripheral glucose and insulin levels after oral (oral glucose tolerance test [OGTT]) and sustained stable hyperglycemic challenge (clamp) in dogs who had undergone pancreas autotransplantation with intraperitoneal drainage (PAT) or with urinary bladder to pancreatic duct anastomosis (PAT/B). Both groups had basal glucose values comparable to normal controls; PAT/B animals had fasting hyperinsulinemia. Pancreas autotransplantation animals had an increased integrated glucose response to OGTT and blunted insulin response to hyperglycemic clamp. Urinary bladder to pancreatic duct anastomosis animals had a significantly decreased integrated glucose response to OGTT compared to PAT and an exaggerated insulin response to hyperglycemic challenge, which approximated normal control values by the last 30-minute period of the clamp. Interestingly M values, which approximate glucose metabolized during the hyperglycemic challenge, were depressed in both surgical groups. It is concluded that the technique of bladder drainage allows a 'normalization' of peripheral levels of insulin that is associated with amelioration of an altered glucose response after oral challenge. However the clamp studies show that, despite the improvement in insulin response, an insensitivity may exist to a wide range of endogenous levels after pancreas transplantation.

Anastomosis, Surgical↗
PubMed1991

Laparoscopic cholecystectomy. Treatment of choice for symptomatic cholelithiasis.

Our initial experience with laparoscopic cholecystectomy (LC) for symptomatic cholelithiasis has involved 152 patients. Patient age ranged from 17 to 83 years; most were female (78%). Their average weight was 170 pounds (range, 75 to 365 lbs.). Twenty-two per cent had a single gallstone, while 9% had two to three stones and 64% had more than three stones. Exclusion criteria initially included upper abdominal scarring, severe acute cholecystitis, choledocholithiasis, and inability to tolerate general anesthesia. The first two of these are now only relative contraindications with increased experience. Thirteen of the one hundred fifty-two procedures (8.5%) required conversion to an open operation. Average time of operation was 138 minutes. Intraoperative cholangiography was attempted in 78% of cases and was completed successfully in 66% of those attempted. There have been no deaths. The complication rate has been low: 4% major, 0% life-threatening, and 7.2% minor complications. Postoperative analgesic requirements are remarkably low: 36% of patients required no narcotics after leaving the recovery room. Eighty-seven per cent of patients successfully undergoing LC were discharged by the first postoperative day. Most patients resumed normal activities within 1 week after discharge. Laparoscopic cholecystectomy offers the majority of patients with symptomatic cholelithiasis an improved treatment option, resulting in significantly less postoperative pain, hospitalization, and recuperation time.

Adolescent↗
PubMed1990

Effect of verapamil on insulin-stimulated choleresis.

Insulin is one of several neurohumoral substances known to have a choleretic effect in vivo and in the isolated perfused rat liver. Infusion of insulin in the perfused rat liver preparation results in stimulation of bile acid-independent bile flow evidenced by increased bile flow, decreased bile acid concentration, and stable bile acid output. The mechanism of insulin-stimulated choleresis is unknown but may involve calcium as an intracellular second messenger. The present studies were performed to assess the role of membrane calcium channels in mediating choleresis and insulin-stimulated bile acid-independent bile flow in the in situ perfused rat liver. We have shown that verapamil, a specific calcium channel blocker, has no effect on bile flow, bile acid concentration, or bile acid output during bile acid-stimulated choleresis at a taurocholate infusion rate of 40 or 80 nmole/g liver/min. Insulin caused a significant increase in bile flow (18-30%) and a decrease in bile acid concentration (13-21%) without affecting bile acid output at a taurocholate infusion rate of 40 or 80 nmole/g liver/min. Verapamil failed to inhibit insulin-stimulated choleresis at a taurocholate infusion rate of 80 nmole/g liver/min. Although we observed an insulin-stimulated increase in bile flow and a decrease in bile acid concentration in the presence of verapamil at a taurocholate infusion rate of 40 nmole/g liver/min, these changes failed to reach statistical significance. We conclude that verapamil has no effect on choleresis or insulin-stimulated bile flow in the perfused rat liver and that the mechanism by which insulin promotes bile acid-independent bile flow is not mediated by verapamil-sensitive calcium channels.

Animals↗
PubMed1989

Effect of glipizide on the surgically altered pancreas.

Surgical alterations of the pancreas affect peripheral glucose, insulin, and glucagon levels with accompanying changes in carbohydrate metabolism. The sulfonylurea glipizide has been used to treat insulin-deficient states; however, its mechanism is not completely known. We hypothesized that glipizide would correct postoperative changes in glucose handling in a way that would allow more complete understanding of the drug's action. Two surgical groups (Group 1:80 percent proximal pancreatectomy; Group 2: proximal pancreatectomy plus splenocaval diversion) were compared with a healthy control group (Group 3). We have concluded that glipizide may have affected basal insulin sensitivity in the control group and Group 2 animals without affecting insulin secretion in response to oral or intravenous glucose stimulation. Glipizide does not correct the alterations in glucose handling or insulin secretion after reduction in beta-cell mass.

Animals↗
PubMed1989

Great expectations: stress and the medical family. 1987 Committee on Issues, Association for Academic Surgery.

The high divorce rate and significant stress experienced by families of academic surgeons stimulated the Committee on Issues of the Association of Academic Surgery to choose medical family stress as the topic for the 1987 Committee presentation at the annual meeting. The Committee hoped to provide insight into the cause of this stress and new strategies for coping with this pervasive problem. Forty-three percent of the 505 surgeons who entered the Association from 1981 through 1984 and 38% of their spouses responded to a questionnaire covering issues of time management, response to stress, child rearing, financial security, and spouse career. A panel consisting of Shirley P. Levine, M.D., Hiram C. Polk, Jr., M.D., and Lane A. Gerber, Ph.D., after discussing the questionnaire results, recommended realistic goal setting, specific prioritization of activities, recognition of the considerable contributions of the spouse, and insight into personal limitations as mechanisms for improving family function.

Female↗
PubMed1989

Insulin-dependent and insulin-independent effects after surgical alterations of the pancreas.

Anatomic alterations of the pancreas result in physiologic alterations that have not been completely analyzed. Insulin plays a major role in carbohydrate metabolism; nevertheless, as much as 50% of a hyperglycemic load may be metabolized independent of insulin. We analyzed the effects of surgical alterations of the pancreas on postoperative glucose metabolism, including insulin-independent effects. Mongrel female dogs underwent one of three procedures: proximal partial pancreatectomy (PPx), PPx plus diversion of pancreatic venous effluent to the systemic circulation (SC), or PPx plus segmental pancreatic autotransplantation (PAT). Intravenous glucose tolerance tests, with or without a background infusion of somatostatin (SST; 400 ng/kg/min) were performed on all animals preoperatively and postoperatively. SST completely suppressed secretion of assayable peripheral insulin. The rate of glucose disposal during SST suppression approximates the rate of insulin-independent glucose disposal (IIGD). Although there was a significant decrease in the rate of glucose disposal during SST infusion when compared with the rate without SST, no differences in IIGD were found between postoperative groups. IIGD was calculated at 50% to 55% for control, PPx, and SC groups and at 67% for PAT. Peripheral sensitivity to an exogenous insulin infusion (euglycemic clamp) was unchanged by any of the procedures. We conclude that surgical alteration of the pancreas, including pancreas transplantation, results in altered glucose handling in the face of "normal" peripheral levels of insulin. Changes in IIGD and analysis of peripheral sensitivity to insulin do not explain these alterations completely.

Animals↗
PubMed1988

Peripheral insulin release after pancreatic resection: the effect of decreased beta-cell mass with systemic or portal drainage.

Surgical alteration of the pancreas can result in several anatomic alterations which may affect insulin release. We evaluated the effects of resection, systemic drainage, and autotransplantation of the canine pancreas on peripheral insulin levels and glucose disposal as measured by iv glucose tolerance tests (IVGTT) and a steady state hyperglycemic challenge (clamp). Proximal pancreatectomy (PPx) with reduced beta-cell mass and intact portal drainage resulted in a modestly elevated fasting glucose level and increased integrated glucose response to IVGTT. Compared to preoperative normals, basal insulin was unchanged from preoperative controls; however, peak insulin and integrated insulin response to IVGTT were decreased in PPx animals. Splenocaval drainage or autotransplantation of the distal pancreas resulted in normalization of the severely altered insulin response and fasting glucose levels. K values were significantly reduced after all three procedures. Clamp studies confirmed the basal glucose and insulin findings of the IVGTT. During the clamp, PPx animals had peripheral insulin values approximately 50% of normal controls, while autotransplantation and splenocaval drainage animals had insulin values that approximate normal controls. All three postsurgical groups had blunted insulin levels during stable hyperglycemia. Glucose utilization rates were severely decreased in all three groups. Reduction of beta-cell mass with intact portal drainage resulted in reduced insulin response to glucose challenge by either IVGTT or clamp. Systemic drainage of this same reduced beta-cell mass resulted in peripheral insulin levels comparable to normal controls. Denervation (autotransplantation) had little additive effect. All three groups demonstrated severely decreased rates of glucose disappearance as measured by both IVGTT and clamp studies. Therefore, reduction in beta-cell mass, drained systemically or portally, results in altered glucose disposal regardless of the peripheral insulin levels.

Animals↗
PubMed1988

Choledochocele: a rare form of choledochal cyst.

Choledochocele is the least common form of cystic dilatation of the biliary tree. Whether this condition is a congenital abnormality or the result of inflammation at the papilla of Vater is not clear. In most cases, the clinical presentation is that of intermittent abdominal pain, nausea, and vomiting, with biliary colic and/or jaundice. As described in our case, choledochocele has characteristic radiologic features, but the lesion can be easily overlooked if one is not aware of its distinctive appearance.

Aged↗
PubMed1987

Experimental studies of biliary excretion of piperacillin.

The nonrecirculating isolated perfused rat liver was used to study biliary antibiotic excretion by the liver in a steady-state, controlled environment in which bile flow, bile salt output, and antibiotic delivery were maintained under constant conditions. The effects of piperacillin, ampicillin, and gentamicin on bile flow and bile salt output were analyzed; none altered bile salt output, and only high concentrations of piperacillin (100 micrograms/mL) increased bile flow. The ratio of antibiotic concentration in bile and perfusate depended on the type of antibiotic and perfusate concentration. Piperacillin infusions at perfusate concentrations of 50 or 100 micrograms/mL (in the presence of 60 microM taurocholate) yielded bile to perfusate ratios of 112 +/- 10 versus 49 +/- 3, respectively. Using similar perfusate, the concentration ratios for ampicillin (20 micrograms/mL) and gentamicin (10 micrograms/mL) were only 3.4 +/- 0.5 and 0.5 +/- 0.1, respectively. By altering the perfusate to contain either 60 microM or 240 microM taurocholate, we found variance in bile salt output from 27 +/- 1 to 115 +/- 2 mumol/h, yet this alteration had little effect on the output of ampicillin (perfusate concentration of 20 micrograms/mL), 73 +/- 7 versus 74 +/- 12 micrograms/h, or piperacillin (perfusate concentration 100 micrograms/mL), 10 +/- 1 versus 11 +/- 2 mg/h. Thus, it appears ampicillin and piperacillin are excreted into bile at high concentrations by bile salt-independent pathways. Partial biliary obstruction (6 cm H2O) results in significant decreases in bile volume. Infusion of 50 micrograms/mL of piperacillin resulted in increased biliary flow that approached nonobstructed values. Obstruction resulted in significant decreases in bile piperacillin concentration. Whether the choleretic effect of high concentrations of piperacillin has any clinical significance in nonobstructed or obstructed conditions remains to be established.

Ampicillin↗
PubMed1986

Evaluation of insulin secretion after pancreas autotransplantation by oral or intravenous glucose challenge.

Segmental pancreatic autotransplantation is accompanied by surgical alterations to the pancreas that may have consequences for carbohydrate metabolism. Four mongrel dogs were evaluated before operation and sequentially until 40 weeks after total pancreatectomy and autotransplantation of the splenic lobe of the pancreas with bolus intravenous and oral administration. Intravenous glucose tolerance test (IVGTT) (0.5 g/kg) revealed maintenance of fasting euglycemia for as long as 40 weeks after operation. Peak glucose and integrated glucose values did not show significant changes as a result of autotransplantation. Following transplantation, a delayed peak insulin response was seen; however, basal, peak, and integrated insulin values were largely unaltered. Only K values, a measure of glucose disposal, showed severe alterations (2.44 +/- 0.21 before operation to 1.24 +/- 0.30 at 40 weeks after operation). Oral glucose tolerance tests (OGTT) (2.0 g/kg) demonstrated an increased peak hyperglycemic response after autotransplantation with increased integrated glucose responses. Insulin levels remained at those levels seen before operation, and glucose-dependent insulinotropic polypeptide (GIP) responses were unchanged during the OGTT as late as 20 weeks after operation. In conclusion, pancreas autotransplantation after total pancreatectomy results in significant metabolic alterations that the IVGTT fails to detect with absolute glucose or insulin levels. However, K values are significantly lowered, which indicates alterations in cellular glucose transport. The OGTT demonstrates hyperglycemia without increased insulin or GIP levels, which suggests an altered beta cell response to the enteric stimulus of insulin release. These changes are nonetheless well tolerated by animals that have remained clinically healthy and euglycemic in the basal state.

Animals↗
PubMed1986

Solitary hamartomatous polyp of the duodenum in the absence of familial polyposis.

A large hamartomatous polyp of the Peutz-Jegher type was discovered in the distal duodenum by endoscopy in a patient with occult gastrointestinal bleeding. There were no other polyps in the gastrointestinal tract and the patient lacked any stigmata associated with the familial polyposis syndromes. This is the second well-documented case of an isolated hamartomatous polyp of the Peutz-Jegher type in the small intestine occurring in the absence of familial polyposis.

Adenomatous Polyposis Coli↗
PubMed1985

Bile duct carcinoma. Diagnosis and treatment.

Fifty-three patients were evaluated for carcinoma of the extrahepatic bile ducts at the University of Virginia from 1951 to April 1984. This population was retrospectively reviewed and 33 preoperative and postoperative variables were analyzed to evaluate the predictors of increased survival. No preoperative data, including symptoms, admitting laboratory data, or tumor location, predicted increased survival. Whipple resection yielded a median survival of 12 months; palliative resections, 1.5 months; and laparotomy, only 5.5 months; these differences were not statistically significant. Experience with six patients treated with internal radiation (iridium-192), plus as much as 4000 rads of external beam irradiation, suggests that this combination of radiation treatment may aid palliation.

Adenoma, Bile Duct↗
PubMed1985

Primary small bowel malignancies.

Fifty-five patients with primary small bowel malignancies were evaluated from 1955 to 1983. Twenty-seven patients (49%) had carcinoid tumors, 16 (29%) had adenocarcinomas, and 12 (22%) had leiomyosarcomas. The average age at presentation was 68 years (range: carcinoids, 27-82; leiomyosarcomas, 36-75; adenocarcinomas, 40-83). Carcinoids and leiomyosarcomas were 1.7 and 2.0 times, respectively, more common in men; adenocarcinomas showed no sex predominance. Eighty-nine per cent of all patients had symptoms: abdominal pain in 65 per cent, obstruction in 23 per cent, bleeding in 8 per cent, and palpable mass in 5 per cent. Although 27 per cent of carcinoid patients were asymptomatic, 40 per cent exhibited the carcinoid syndrome. Symptoms were longstanding in the majority of cases, and, at the time of diagnosis, 49 per cent of the carcinomas were metastatic. Fifty-five per cent of the tumors were in the ileum, 24 per cent in the jejunum, and 21 per cent in the duodenum. Fifty-five patients (89%) underwent resection for palliation or cure. Five adenocarcinoma patients (32%) survived 1 year, and one (6%) lived 10 years. Twenty-five per cent of leiomyosarcoma patients survived for 10 years. Eighty-seven per cent of patients with carcinoids survived for 1 year, 39 per cent for 5 years, and 22 per cent for 10 years. Previous reports have documented the difficulty of diagnosing these lesions, as does the present study. A higher degree of physician awareness and a more aggressive investigation of referable symptoms should lead to earlier treatment and better long-term results.

Adenocarcinoma↗
PubMed1984

Insulin's effect on bile flow and lipid excretion during euglycemia and hypoglycemia.

Mongrel dogs were prepared by cholecystectomy, ligation of the lesser pancreatic duct, and insertion of modified Thomas cannulas into the stomach and duodenum. When the dogs had recovered from surgery, studies were performed on them, conscious and unanesthetized after an overnight fast. The common bile duct was catheterized through the opened duodenal cannula for collection of hepatic bile. Bile flow was stabilized by the intravenous infusion of sodium taurocholate. After 2 hr of taurocholate infusion, insulin was added to the infusion and continued for the duration of the experiment. Glucose was administered intravenously during the first 120 min of insulin administration to maintain euglycemia; then the glucose was discontinued. The intravenous infusion of insulin during euglycemia maintained by glucose infusion caused a significant increase in bile flow and a decrease in bile salt concentration, but no change in bile salt output. There was a decrease in cholesterol concentration and output and in phospholipid concentration, but no significant change in phospholipid output. When glucose infusion was discontinued and hypoglycemia occurred, there was a further significant increase in bile flow, but no other change. These studies demonstrate that the choleretic action of insulin is not dependent upon hypoglycemia and that intravenously administered insulin may cause increased bile secretion without increase in serum glucagon concentration. These experiments also confirm that insulin choleresis may be associated with a decline in cholesterol output.

Animals↗