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PDX1 (pancreatic and duodenal homeobox 1) is overexpressed in pancreatic cancer, and its reduction results in tumor regression. Bi-functional pbi-shRNA PDX1 nanoparticle (OFHIRNA-PDX1) utilizes the endogenous micro-RNA biogenesis pathway to effect cleavage- and non-cleavage-dependent degradation of PDX1 mRNA. We have shown that OFHIRNA-PDX1 reduces pancreatic tumor volume in xenograft models. Thus, we are now exploring biorelevant large animal safety of OFHIRNA-PDX1. Mini pigs were chosen as the biorelevant species based on the similarity of human and pig PDX1 target sequence. In the initial study, animals developed fever, lethargy, hyporexia and cutaneous hyperemia following administration of OFHIRNA-PDX1. Twenty-one days later, the same animals demonstrated less toxicity with a second OFHIRNA-PDX1 infusion in conjunction with a prophylactic regimen involving dexamethasone, diphenhydramine, Indocin and ranitidine. In a new group of animals, PDX1 protein (31 kDa) expression in the pancreas was significantly repressed at 48 and 72 h (85%, P=0.018 and 88%, P=0.013; respectively) following a single infusion of OFHIRNA-PDX1 but recovered to normal state within 7 days. In conclusion, a single intravenous infusion of OFHIRNA-PDX1 in conjunction with premedication in pigs was well tolerated and demonstrated significant PDX1 knockdown.

Deregulated expression of zinc transporters was linked to several cancers. However, the detailed expression profile of all human zinc transporters in normal human organs and in human cancer, especially in pancreatic cancer is not available. The objectives of this study are to investigate the complete expression patterns of 14 ZIP and 10 ZnT transporters in a large number of normal human organs and in human pancreatic cancer tissues and cell lines. We examined the expression patterns of ZIP and ZnT transporters in 22 different human organs and tissues, 11 pairs of clinical human pancreatic cancer specimens and surrounding normal/benign tissues, as well as 10 established human pancreatic cancer cell lines plus normal human pancreatic ductal epithelium (HPDE) cells, using real time RT-PCR and immunohistochemistry. The results indicate that human zinc transporters have tissue specific expression patterns, and may play different roles in different organs or tissues. Almost all the ZIPs except for ZIP4, and most ZnTs were down-regulated in human pancreatic cancer tissues compared to the surrounding benign tissues. The expression patterns of individual ZIPs and ZnTs are similar among different pancreatic cancer lines. Those results and our previous studies suggest that ZIP4 is the only zinc transporter that is significantly up-regulated in human pancreatic cancer and might be the major zinc transporter that plays an important role in pancreatic cancer growth. ZIP4 might serve as a novel molecular target for pancreatic cancer diagnosis and therapy.

Pancreatic cancer is a multiple genetic disorder with many mutations identified during the progression. Two mouse pancreatic cancer cell lines were established which showed different phenotype in vivo: a non-metastatic cell line, Panc02, and a highly metastatic cell line, Panc02-H7, a derivative of Panc02. In order to investigate whether the genetic mutations of key genes in pancreatic cancer such as KRAS, TP53 (p53), CDKN2A (p16), SMAD4, ZIP4, and PDX-1 contribute to the phenotypic difference of these two mouse pancreatic cancer cells, we sequenced the exonic regions of these key genes in both cell lines and in the normal syngeneic mouse pancreas and compared them with the reference mouse genome sequence. The exons of KRAS, SMAD4, CDKN2A (p16), TP53 (p53), ZIP4, and PDX-1 genes were amplified and the genotype of these genes was determined by Sanger sequencing. The sequences were analyzed with Sequencher software. A mutation in SMAD4 was identified in both cell lines. This homozygote G to T mutation in the first position of codon 174 (GAA) generated a stop codon resulting in the translation of a truncated protein. Further functional analysis indicates that different TGF-β/SMAD signaling pathways were involved in those two mouse cell lines, which may explain the phonotypic difference between the two cells. A single nucleotide polymorphism (SNP) in KRAS gene (TAT to TAC at codon 32) was also identified in the normal pancreas DNA of the syngenic mouse and in both derived tumoral Panc02 and Panc02-H7 cells. No mutation or SNP was found in CDKN2A (p16), TP53 (p53), ZIP4, and PDX-1 genes in these two cell lines. The absence of mutations in genes such as KRAS, TP53, and CDKN2A, which are considered as key genes in the development of human pancreatic cancer suggests that SMAD4 might play a central and decisive role in mouse pancreatic cancer. These results also suggest that other mechanisms are involved in the substantial phenotypic difference between these two mouse pancreatic cancer cell lines. Further studies are warranted to elucidate the molecular pathways that lead to the aggressive metastatic potential of Panc02-H7.

Many transcription factors are critical for ensuring proper embryonic development of the endocrine pancreas and normal islet function. The transcription factor pancreatic duodenal homeobox 1 (PDX-1) is uniformly expressed in early pancreatic buds of embryos as well as the beta and delta cells of the islets of Langerhans. PDX-1 has also been found in dispersed endocrine cells of the duodenum in adults and plays a key role in pancreas formation. It has been reported that null mutation of PDX-1 in mice results in a failure of the pancreatic bud to expand; thus, the mice die 2-3 days after birth from hyperglycemia and dehydration. Heterozygous PDX-1 mice developed a pancreas but were diabetic. It has been shown that PDX-1 is required for maintaining the pancreatic islet functions by activating gene transcriptions including insulin, somatostatin (SST), islet amyloid polypeptide, glucose transporter type 2, and glucokinase. PDX-1 serves a dual role in pancreatic development. It initially contributes to pancreatic formation during embryogenesis and subsequently regulates the pancreatic islet cell physiology in mature islet cells. Understanding the underlying molecular mechanisms of pancreas formation, especially the function of PDX-1, may contribute to the enhanced treatment and prevention of debilitating diseases such as diabetes, insulinomas, and pancreatic carcinomas.

Laparoscopic techniques for the repair of inguinal hernias have become an increasingly popular alternative to open techniques. No clear consensus has emerged as to the best laparoscopic technique, but the body of evidence increasingly favors a total extraperitoneal (TEP) approach.We report the case of an adult man with an incarcerated right indirect inguinal sliding hernia involving the first known instance of a retroperitoneal ileum, and the novel use of a laparoscopic combined TEP approach and transabdominal preperitoneal (TAPP) approach to repair his hernia without complications. The literature is reviewed and TEP and TAPP techniques for the treatment of inguinal hernias are discussed and compared.When faced with an unforeseen anomaly during herniorrhaphy in which improved abdominal visualization is necessary, a surgeon may convert from a TEP to a transabdominal laparoscopic approach safely and effectively.

RNA interference (RNAi) represents a powerful, new tool for scientific investigation as well as a promising new form of targeted gene therapy, with applications currently in clinical trials. Bifunctional short hairpin RNA (shRNA) are synthetic RNAi molecules, engineered to utilize multiple endogenous RNAi pathways to specifically silence target genes. Pancreatic and duodenal homeobox 1 (PDX1) is a key regulator of pancreatic development, β-cell differentiation, normal β-cell function and pancreatic cancer. Our aim is to review the process of identifying PDX1 as a specific, potential RNAi target in pancreatic cancer, as well as the underlying mechanisms and various forms of RNAi, with subsequent testing and development of PDX1-targeted bifunctional shRNA therapy.

Chronic pancreatitis (CP) is associated with lowered plasma levels and a blunted nutrient-induced release of pancreatic polypeptide (PP). To investigate the possible role of PP on glucose metabolism, we studied male patients with documented CP (n = 5) and obesity-matched control subjects (NL) (n = 6). Hepatic glucose production (HGP) and overall glucose disposal rates were determined by [3-3H]glucose infusion during a hyperinsulinemic-euglycemic clamp during three separate admissions. Basal rates of HGP were higher in CP patients. In response to an infusion of insulin (60 pmol.m-2.min-1), HGP fell 91 +/- 5% in NL subjects but only 68 +/- 8% in CP subjects (P < 0.05). One month later, the clamp was repeated during the final 2 h of an 8-h infusion of bovine PP (2 pmol.kg-1.min-1). HGP before the insulin infusion and its subsequent suppression (NL: 83 +/- 5%; CP: 86 +/- 15%) were nearly identical between groups. In follow-up studies 1 month after the PP infusion, HGP both basally and in response to insulin alone were similar to the first study. During oral glucose tolerance tests (OGTT) performed 18 h after the PP infusion, subjects with normal (n = 7) baseline OGTT responses showed no effect. All patients with diabetic (n = 3) or nondiagnostic (n = 1) OGTT responses, however, demonstrated lowered mean plasma glucose levels (approximately -2.3 mmol/L; range: -0.6 to -7.2 mmol/L). OGTTs repeated 1 month after the PP treatment showed a return to pretreatment responses. We conclude that chronic pancreatitis accompanied by PP deficiency is associated with partial hepatic resistance both in the basal state and in response to hyperinsulinemia. This impairment is reversed after iv PP administration. PP deficiency may therefore play a role in the development of pancreatogenic diabetes caused by pancreatic injury.

To test the effect of endogenous pancreatic polypeptide (PP) on rat hepatic glucose homeostasis by immunoneutralization, a rat PP-specific monoclonal antibody (MAb) was produced. Binding of this IgG1 monoclonal antibody was inhibited 50% by 350 pM rat PP. Immunohistochemistry showed that the antibody produced the expected pattern of endocrine cell staining in rat pancreas. Groups of six adult male Sprague-Dawley rats were given 5 mg of Protein-A-purified anti-PP MAb or anti-KLH MAb (control) ip every 48 hr for 5 dosing intervals. The rate of hepatic glucose output during isolated liver perfusion was 0.25 +/- 0.03 mg/g/min for the PP MAb-treated rats and 0.17 +/- 0.02 mg/g/min for the control group (p0.05). Liver glycogen content was 21.8 +/- 2.9 mg/g for the PP MAb-treated rats and 14.7 +/- 2.4 mg/g for the control group (N = 5). Chronic in vivo immunoneutralization of PP with this new monoclonal antibody suggests that PP influences glucose homeostasis in the rat by affecting hepatic glucose output.

The human immunodeficiency virus (HIV) causes acquired immunodeficiency syndrome, which remains uniformly fatal in affected individuals. A common route of HIV transmission is via inoculation of contaminated blood, which may occur during surgical procedures. Surgeons may estimate their risk of HIV infection over a 30-year surgical career based on HIV prevalence among surgical patients, percutaneous injury rate per operation, and seroconversion rate. Surgeons can reduce their risk by various means, but the most pragmatic is by reducing the rate of percutaneous injury through optimal surgical technique and proper precautions.

OBJECTIVE: The somatostatin-secreting delta cells in the islets of Langerhans appear to be regulated by neural mechanisms that have not been defined clearly. In this study, the celiac neural bundle of the human pancreas was electrically stimulated in the presence and absence of selective neural antagonists. SUMMARY BACKGROUND DATA: The authors previously reported on studies of the splanchnic neural regulation of insulin, glucagon, and pancreatic polypeptide secretion. In these studies, alpha-adrenergic fibers appeared to have a predominant effect, strongly inhibiting the secretion of insulin, glucagon, and pancreatic polypeptide secretion. Cholinergic fibers appeared to stimulate strongly, although beta-adrenergic fibers weakly stimulated, the secretion of these hormones. Investigations of neural regulatory mechanisms governing human somatostatin release in vitro have not been previously reported. METHODS: Pancreata were obtained from eight cadaveric organ donors. The isolated perfused human pancreas technique was used to assess the regulation of somatostatin secretion by the various neural fibers contained within the celiac plexus. The secretory response of somatostatin was examined in the presence of 16.7 mmol/L glucose, with and without neural stimulation, and specific neural antagonists. RESULTS: The basal somatostatin secretion was 88 +/- 26 fmol/g/min and increased 131 +/- 23% (n = 8, p < 0.01) in response to 16.7 mmol/L glucose. The augmentation seen with glucose was inhibited 66 +/- 22% (n = 8, p < 0.05) during celiac neural bundle stimulation. Alpha-adrenergic blockade resulted in a 90 +/- 30% (n = 6, p < 0.01) augmentation of somatostatin release. Beta-adrenergic blockade caused a 13 +/- 2% (n = 6, p < 0.05) suppression of somatostatin release. Complete adrenergic blockade resulted in a 25 +/- 23% (n = 5, p = not significant) inhibition of somatostatin release. Cholinergic blockade resulted in a 40 +/- 10% (n = 6, p < 0.02) suppression of somatostatin release. CONCLUSIONS: The predominant effect of celiac neural bundle stimulation was inhibition of somatostatin secretion through an alpha-adrenergic effect. Beta-adrenergic fibers stimulate somatostatin secretion; cholinergic fibers have a negligible effect on somatostatin secretion. These data suggest that the splanchnic innervation of the pancreas has a potent regulatory role in somatostatin release in this in vitro human model.

In the pancreas, calcitonin gene-related peptide (CGRP) immunoreactivity has been described in nerve fibers and in distinct types of islet cells. This unique, apparently species-specific cell-type expression prompted the present investigation to clarify further the pattern of CGRP immunoreactivity in different mammalian species (i.e., different strains of rats, mice, guinea pigs, rabbits, cats, dogs, pigs, and humans) commonly used for functional and anatomical studies of the pancreas by means of immunohistochemistry using three different CGRP antibodies. In each species, CGRP-immunoreactive neurites innervate the exocrine and endocrine compartments, the vasculature, and the intrapancreatic ganglia, where they form dense networks encircling unstained cell bodies. The only exception is the pig pancreas, where the islets appear to be devoid of immunoreactive fibers. The overall density of immunoreactive pancreatic axons in different species is as follows: rat, mouse, and rabbit greater than guinea pig greater than or equal to pig and cat much greater than dog and human. CGRP-immunoreactive endocrine cells appear to be restricted to the rat pancreas, where they form a subpopulation of somatostatin-containing D cells. In contrast, in mouse, guinea pig, cat, dog, and human pancreas, a homogeneous staining of the core of the islets, where insulin-producing B cells are located, was visualized in sections incubated with the rabbit CGRP antiserum at 4 degrees C, but not at 37 degrees C (an incubation temperature that does not affect the islet cell staining in the rat nor the fiber labeling in any species). Furthermore, the staining of islet B cells was not reproducible with all the CGRP antibodies used, all of which comparably stain nerve fibers in each species, and islet D cells in the rat. Immunoreactive islet cells were not visualized in pig and rabbit pancreas. These results are consistent with the hypothesis that the expression of CGRP in nerve fibers is a common feature of mammalian pancreas, whereas its expression in endocrine cells appears to be restricted to the D cells of the rat pancreas.

The purpose of this study was to examine the effect of global gene ablation of SSTR5 on the endocrine pancreas, insulin secretion, and glucose tolerance in aging mice, as SSTR5 is a primary regulator of insulin secretion in the mouse pancreas.Global SSTR5-/- mice were generated and genotypes were verified using Southern blot and RT-PCR. Glucose tolerance and in vivo insulin secretion in SSTR5-/- and WT mice were examined using intraperitoneal glucose tolerance test (IPGTT;1.2-2.0 mg/kg) at 3 and 12 months of age (n = 8 per group). Basal and glucose-stimulated insulin secretion in vitro was studied using the isolated perfused mouse pancreas model at 3 and 12 months. Pancreata were removed and levels of insulin, glucagon, somatostatin, and SSTR1 were studied using immunohistochemical analysis along with HE staining of the pancreata.Genotyping verified the absence of SSTR5 in SSTR5-/- mice. IPGTT demonstrated that 3-month-old SSTR5-/- mice were glucose intolerant despite similar insulin secretion both in vivo and in vitro and enlarged islets. At 12 months of age, SSTR5-/- mice had basal hypoglycemia and improved glucose intolerance associated with hyperinsulinemia in vivo and in vitro and enlarged islets. SSTR5-/- mice had increased insulin clearance at 3 and 12 months of age. SSTR1 expression was significantly increased in islets at 3 months of age, but was nearly absent in islets at 12 months of age, as was somatostatin staining in SSTR5-/- mice.These results suggest that both SSTR5 and SSTR1 play a pivotal role in insulin secretion and glucose regulation in mice and that their regulatory effects are age-related.

There is evidence of a local inhibitory effect of somatostatin on insulin secretion in the isolated human pancreas, but this has not been shown in a rat model. The possible phasic effect of somatostatin on insulin secretion has not been demonstrated.This study was undertaken to determine if somatostatin has a local regulatory effect on phasic insulin secretion within a rat pancreas model.The basal and glucose stimulated secretion of insulin was compared with and without immunoneutralization of somatostatin using a somatostatin antibody in an isolated perfused rat pancreas model. High concentration, high affinity monoclonal somatostatin antibody was perfused through isolated rat pancreata. Radioimmunoassay for insulin was performed on the portal effluent.Immunoneutralization of somatostatin during basal insulin secretion produced a rise in insulin secretion of 551 +/- 163% that approached significance. Immunoneutralization during glucose stimulated insulin secretion produced a significant rise in insulin secretion compared to the control group of 2,678 +/- 187% vs. 535 +/- 39% (p0.05). The phase I vs. the phase II response in the glucose stimulated pancreas was similar in the presence of control antibody, 867 +/- 351% vs. 900 +/- 398% (p = NS). With somatostatin immunoneutralization, the glucose stimulated pancreas had a significantly higher phase II response than phase I; 3,832 +/- 688% vs. 2,516 +/- 431% (p0.05).These data indicate that intraislet somatostatin is an inhibitor of insulin secretion in the isolated perfused rat pancreas. This effect occurs primarily in phase II of insulin secretion.

Nonfunctioning neuroendocrine tumors of the pancreas are rare slow-growing tumors with a more indolent natural history compared with pancreatic adenocarcinoma. This retrospective report reviews the surgical experience with nonfunctioning neuroendocrine tumors in an academic referral center. Statistical analysis was performed using Student's t test and Kaplan-Meier method compared with log-rank tests. Thirty-eight patients (24 males and 14 females) underwent surgery for a neuroendocrine tumor of the pancreas from 1984 through 1999. Twenty-eight patients with a mean age of 59.9 years had nonfunctioning islet cell tumors and 10 patients with a mean age of 59.1 years had functioning islet cell tumors (four gastrinomas, three glucagonomas, two insulinomas, and one vipoma). The nonfunctioning islet cell tumors were located in the head, neck, or uncinate process in 14 patients (50%), the body in seven (25%), and the tail in seven (25%). Operative procedures for the nonfunctioning islet cell tumors included nine pancreaticoduodenectomies, 12 distal pancreatectomies, three palliative bypasses, and four exploratory laparotomies without a resection or bypass. Mean survival for the four patients explored and not resected or bypassed was 7 months. Median survival for node-negative patients was 124 months, for node-positive patients 75 months, and for patients with metastasis to the liver 9 months. Estimated 2-year actuarial survival for the node-negative patients was 77.8 per cent, for node-positive patients 71.4 per cent, and for patients with metastasis to the liver 36.4 per cent. Six patients (60%) with node-negative disease, three (43%) with node-positive disease, and one (9%) with metastasis to the liver are alive at a mean follow-up of 41.8 months (range 1-167). Significant differences in median survival and 2-year survival were demonstrated between the node-positive/node-negative patients and those with metastasis to the liver (P = 0.003). Patients with localized nonmetastatic disease should be considered for pancreatic resection as estimated median survival is 75 months or greater. Hepatic metastasis is a major predictor of survival.

A new approach, involving a two-step digestion process and Los Angeles preservation solution #1 (LAP-1), a cold storage solution, was developed for isolation of high-quality islets from human pancreata for transplantation. This approach markedly improves the islet yield, purity and viability, and the isolation success rate. In this method, the pancreas was digested first in warm collagenase solution for up to 20 minutes. After decanting the enzyme solution, partially digested tissue was dissociated by gentle agitation in cold LAP-1 solution without additional collagenase. The digested tissues were stored in cold LAP-1 solution until islet purification on Euro-Ficoll. Forty-six islet isolations were performed consecutively by the new method (group 1). These results were compared to those obtained earlier with 46 consecutive isolations, using our previous method that had been used before development of the new method (group 2). Our old method was a modification of Ricordi's method involving only warm collagenase digestion and the storage of digested tissues in cold Hanks balanced salt solution. All pancreata were partial, containing the body and tail. There were no significant differences in both groups with regard to the donor age, cold ischemic time, harvesting conditions, and pancreatic weight. Pancreas digestion was completed in approximately 1 hour in both groups. The isolation success rate as determined by viable islets after 2 days in culture was 93.5% (43 of 46 cases) in group 1, and 56.5% (26 of the 46) in group 2. Immediately after isolation, the new method yielded a total of 335,739 +/- 36,244 islets equivalent to 150 microm (IEQ) and 6,233 +/- 681 IEQ/g of pancreas with 83 +/- 2.5% purity, whereas the old method yielded a total of 195,587 +/- 25,242 IEQ and 3,763 +/- 5,509 IEQ/g with 69.2 +/- 4.7% purity. Isolated islets in group 1 maintained a good three-dimensional structure, displayed normal insulin release to high glucose stimulation in vitro, and restored euglycemia after transplantation into streptozotocin-diabetic athymic mice. The two-step digestion method provides a sufficient number of islets for transplantation from a single pancreas.

A laparoscopic Nissen fundoplication is more difficult in patients with excessive omental fat, particularly when the surgeon attempts to ligate the short gastric vessels, mobilizing the greater curvature of the stomach and exposing the left diaphragmatic crura. Most surgeons place the patient in steep reverse Trendelenberg to allow gravity to pull the omentum out of the operative field. Despite this maneuver, the omentum can still drape over the splenic hilum and left subphrenic space. Another alternative is to place an additional trocar for a hand-held retractor or grasper. However, this procedure is unnecessarily traumatic and can be avoided. There is a method of retracting the omentum during laparascopic Nissen fundoplications that uses readily available laparoscopic instruments and does not require the placement of an additional port. This simple technique for retracting the omentum during a laparoscopic Nissen fundoplication makes use of the Surgitie, a pretied laparoscopic suture, and the Endo Close (United States Surgical Corporation, Norwalk, CT, USA). A Surgitie is placed through one of the ports to lasso the offending piece of omentum along the greater curvature of the stomach. The suture is cut to its fullest length outside the body, then pulled through the trocar and into the abdomen. Gentle traction is placed on the free end of the secured suture with a laparoscopic grasper until the omentum is retracted to an optimal position for visualization. At this point, a 1-mm incision is made in the skin, and the Endo Close is placed through the abdominal wall and into the abdominal cavity. The location of the 1-mm incision should be at a site that will maintain adequate retraction on the omental fat but keep the pretied laparoscopic suture out of the operative field (usually along the left costal margin). The free end of the suture is grasped by the Endo Close and pulled back through the abdominal wall. The suture is secured outside the abdominal cavity by grasping it with a hemostat flush to the skin. More than one Surgitie can be used if needed. After completing the fundoplication, the suture is cut intracorporally near the secured knot and removed. During the past year, we have performed laparoscopic Nissen fundoplications in seven patients with morbid obesity (Body Mass Index >35). The technique we describe has allowed for improved visualization during ligation of the short gastric vessels, mobilization of the greater curvature of the stomach, and exposure of the left diaphragmatic crura. It has also obviated the need for another trocar. This will free up a pair of hands, decrease the amount of instrumentation in an already crowded operative field, and reduce the potential morbidity of using additional retractors and graspers.

The most critical factors that affect the outcome of clinical pancreatic islet transplantation are the number and quality of donor islets available for transplantation. Toward this goal, we attempted to obtain islets that are both of better quality and higher number than are obtainable by the islet-isolation process that is now widely used. We paid special attention to two critical components of the isolation procedure: minimizing the exposure of pancreatic tissue and freed islets to warm enzyme solution, and development of a preservation solution suitable for islets during cold storage of digested pancreatic tissue-free islets. For this purpose, we developed both a two-step procedure for pancreas digestion and a new cold preservation solution, the LAP-1 solution (Los Angeles preservation solution 1). In this study, we evaluated the effect of four preservation solutions by storing digested pancreatic tissues on ice for 90 min. After the cold storage, islets were purified on three layers of Euro-Ficoll solutions in a 50-ml tube, and the islet yield, viability, and function were determined. These experiments were performed by using samples from 10 consecutive islet isolations. Results with LAP-1, original University of Wisconsin solution (oUW), and modified UW solution (mUW;UW without hydroxyethyl starch) were compared with those obtained with Hank's balanced salt solution (HBSS). The islet yield was significantly higher in the LAP-1 and mUW groups as compared with the HBSS group (p < 0.01). The islet purity was significantly better in the LAP-1, oUW, and mUW groups than the HBSS (p < 0.001). The islet viability was lowest in the HBSS group immediately after purification (vs. LAP-1, oUW, and mUW, p < 0.05) and further decreased during culture (p < 0.01). Both the number and viability of cultured islets were the highest with LAP-1 solution but without statistical significance between mUW and oUW. Electron microscopic examination showed only slight damage to cell membranes immediately after purification of islets stored in LAP-1 solution and their complete recovery within 1-2 days of culture. These islets also exhibited normal insulin responses to high glucose by static incubation and perifusion assays.

Recently five somatostatin receptor subtypes (SSTRs) were cloned, allowing the development of highly specific agonists to these SSTRs. Previous studies have shown a species specificity phenomenon with respect to the inhibition of insulin secretion by these selective agonists. This study was undertaken to determine which SSTR (2 or 5) is responsible for the inhibitory effect of somatostatin on glucose-stimulated mouse insulin secretion.Intact mouse islets (n = 10) were stimulated with D-glucose in the presence or absence of receptor-specific somatostatin agonists.D-glucose (16.7 mmol/L) augmented insulin secretion by 158% above that seen with 3.9 mmol/L D-glucose. In the presence of DC 32-92 (SSTR5) selective agonist, D-glucose (16.7 mmol/L) augmented insulin secretion by 64% above that seen with 3.9 mmol/L D-glucose. The presence of SSTR 5 selective agonist resulted in a significant (P.05) inhibition of glucose-stimulated insulin secretion. The identification of SSTR5 within the mouse pancreas was established by reverse transcriptase polymerase chain reaction and confirmed by Southern blot analysis.These results suggest that the inhibitory effect of somatostatin on insulin secretion is mediated through the subtype 5 receptor within the mouse islet.

Laparoscopic hernia repairs have been demonstrated to be safe and effective, with less postoperative pain and earlier return to work than with open repairs. Modifications of the laparoscopic technique are evolving that attempt to reduce the overall complication rate while maintaining an effective repair. From January 1994 through July 1995, 67 inguinal hernias on 40 patients were repaired using the total extraperitoneal approach at UCLA Medical Center. Of the 67 hernias, four (6%) were pantaloon, 16 (24%) were indirect, and the remainder (70%) were direct. Three patients of 40 (7.5%) had complications that included seromas (two patients) and urinary retention (one patient). The early recurrence rate is zero, with a mean follow-up period of 6 months. The average time taken off from work was 2 days, with a range of zero to 10 days. Total extraperitoneal laparoscopic hernia repair is a modified technique associated with low early recurrence and few complications. In addition, earlier return to work results in less patient inconvenience, greater productivity, and reduction in medical disability expenses.

This article reviews the basic concepts and techniques of time management as they relate to a medical lifestyle. Essential tools are described to help the physician reassess and sharpen skills for handling intensifying demands and constraints of juggling patient care, research, teaching, and family responsibilities. The historical background and principles of time management for three popular "best selling" techniques are critiqued. In addition, a fourth technique, or model, of time management is introduced for physician use.

T o discuss the controversy of the current concept of islet microcirculation, an international symposium was held at the Long Beach Veterans Administration Regional Medical Education Center (Long Beach, C:A) and broadcast over the Internet via the world Wide Web to 14 international stations. Studies concerning three models of islet microcirculation, mantle-to-core, coreto-mantle, and polar, were presented. One presentation, including an interactive question and answer session, was broadcast from the Massachusetts Institute of Technology (Cambridge, MA) and received by the symposium participants in Long Beach, as well as by the 14 stations. The fundamental differences between the models, i.e., the relationship of the microcirculation flow pattern and the islet cell composition, were discussed in an open forum with critiques of techniques, results, and interpretations. Each islet has from one to five arterioles, which penetrate into the islet and divide into numerous capillaries (1-4). The capillaries, resembling a glomerulus, course through the islet in a tortuous fashion that is ideal for cell-blood and bloodcell interactions. The a-, p-, 6-, and PP-cells, which secrete glucagon, insulin, somatostatin, and pancreatic polypeptide, respectively, are nestled between the capillaries and receive their nutrient, hormonal, and neurohormonal regulatory signals across the capillary endothelium, as well as through the interstitial space (5,6). Since the cell types have specific locations within the islet, the pattern of blood flow through the islet should have a significant impact on the ability of cells to intercommunicate within the islet. It is this relationship that represents the controversial topic that was the focus of the symposium. The following is a review of the

In vivo fluorescent microscopy with direct observation of flow through the islet was used to investigate the islet microcirculation. In urethane-anesthetized rats (n = 18), the pancreas was exposed and an islet was identified under direct microscopy. The vertical illuminator for fluorescent microscopy was turned on and fluorescein-albumin conjugate or fluorescent microspheres were injected intravenously or intraarterially. Each study was videotaped; on slow motion playback, the flow of the conjugate or microspheres was followed through the islet, the islet capillaries, and then to venules exiting the islet. One islet in the head of the pancreas in 12 rats was studied. The arterioles first reached the surrounding mantle of the islet where they divided into capillaries that carried conjugate or microspheres to other portions of the mantle or the core of the islet. Flow of conjugate traversed the core and returned to different portions of the mantle. The fluorescent microsphere study permitted a more detailed study of the pathways followed, the individual microspheres being seen to travel through numerous tortuous pathways through the islet. The flow of microspheres was nonhomogeneous in that individual microspheres in one portion of the islet would stop, then move on, while other microspheres flowed freely. The capillaries joined two to six venules that carried the conjugate or microspheres out of the islet. One or two of the exiting microvessels entered the adjacent acinar microcirculation; the others entered larger collecting venules. In six tail islets studied, the microcirculation was similar to that of the islets in the head of the pancreas.(ABSTRACT TRUNCATED AT 250 WORDS)

Passing the stomach behind the esophagus during laparoscopic Nissen fundoplication is a common source of frustration for the laparoscopic surgeon. It often leads to an incorrect formation of the fundoplication, resulting in a wrapping or twisting of the fundus around the distal esophagus. The correct technique should result in the distal esophagus being enveloped inside the fundus without distorting the orientation of the greater curve. We have developed an easy, precise, and reproducible technique to perform this maneuver. The steps for performance of this maneuver are described.

Air embolism is a rare but potentially lethal complication of surgical procedures. We report an air embolus that occurred during pulsed saline lavage of a perineal laceration in a patient with an open pelvic fracture. Treatment consisted of aspiration of air from central venous lines and the patient recovered without sequelae.