The most important role of the mentor is to guide the mentee in finding own solutions to problems. An interview with Prof. Henri Sarles. Interview by Martín E. Fernández-Zapico

In this interview for Pancreatology, Professor Henri Sarles shares his life experiences as clinical expert and scientist in pancreatic research. He is a pancreatologist recognized worldwide for his contribution to the understanding of pancreatic diseases. In particular, he led the way in the pancreatitis field with the characterization of pathogenesis of chronic pancreatitis.

'The most important duty of a mentor remains his availability'. An interview with Dr. Jean Morisset. Interview by Martin E Fernandez-Zapico

We interview Dr. Jean Morisset, an internationally recognized leader in the field of pancreatic physiology. His work on the regulation of pancreatic secretion by hormones and the parasympathetic nervous system has been fundamental to the understanding of pancreatic adaptation to diet in normal as well as pathological conditions. Here he provides advices for young investigators starting in the field of pancreatic research and emphasizes the key role of the relationship mentor-mentee during the career development. and IAP.

Characterization of insulin adsorption in the presence of albumin by time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy

With a view to develop an encapsulation membrane for a bioartificial pancreas, we have studied the adsorption of insulin and human serum albumin (HSA) on it. The aim of this study was to determine the possibility of insulin detection on a polycarbonate membrane surface in the presence of HSA, an abundant blood protein. The first step of the work consisted in the identification of time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS) specific signals for insulin and albumin. For this purpose, adsorption isotherms in physiological conditions (pH = 7.2, T = 37 degrees ) were established for the two proteins by looking at the SIMS intensity variations of the characteristic protein and substrate fragments when increasing the protein concentration in the solution. The CHS+ ToF-SIMS fragment and the S2p XPS peak were identified as representative insulin signals. The second step of the work consisted in performing simultaneous adsorption of the two proteins with increasing insulin concentration. We observed an increase of the insulin signal in ToF-SIMS and XPS for insulin concentration beyond 5 microg/mL. Principal component analysis (PCA) of the ToF-SIMS results permits us to obtain information about the protein layer composition. The results show that at low relative insulin concentration in solution, the mixed adsorbed layers are enriched in insulin compared to the solution.

The anatomy and physiology of the avian endocrine system

The endocrine system of birds is comparable to that of mammals, although there are many unique aspects to consider when studying the anatomy, physiology, and biochemistry. Avian endocrinology is a field of veterinary medicine that is unfamiliar to many practitioners; however, it is important to have a comprehensive understanding when evaluating companion birds in clinical practice. This article covers the anatomy and physiology of the normal avian, and readers are referred to other articles for a more detailed explanation of altered physiology and pathology.

Experimenting with chymical bodies: Reinier de Graaf's investigations of the pancreas

In the late seventeenth century, traditions in anatomy and chymistry came together to ground new theoretical and experimental approaches to understanding the animal body. The researches of Dutch experimenters Reinier de Graaf and his mentor Franciscus Sylvius provide keen insight into the ways experiments were constructed, negotiated, and thought about by leading anatomists and physicians of the time. The objects and approaches de Graaf used in the laboratory--ligature, inflation, injection, tubes, vessels, tasting--were derived from broadly Harveian anatomical and Helmontian chymical traditions. Experimental traditions and a comprehensive and materialistic chymical theory of acid-alkali interactions unified the artificial and the natural and allowed de Graaf to create and use hybrid animal-apparatus constructions as tools to collect and assay the key ingredients of digestion and disease.

The avian pancreas in health and disease

The avian endocrine pancreas shares some similarities with mammals but also some clinically relevant differences in anatomy and physiology. Diabetes mellitus, an uncommon disease of pet birds, is a challenging condition because of lack of knowledge of the exact pathophysiology and responses to insulin therapy. This article reviews the anatomy and physiology of the avian pancreas and describes the etiology, diagnosis, and treatment of diabetes mellitus in pet birds.

[Morphofunctional condition of the pancreas in children and teenagers with obesity and metabolic syndrome]

30 childs and teenagers (6- 15-years-old) were examined (16 boys and 14 girls). The signs of metabolic syndrome were revealed in 13 persons (43%) (VOZ, 1999). Echogenicity of pancreatic acinar tissue was reinforced in all persons with obesity, (80%) hyperechogenic inclusions were observed in 67% of the patients. Trustworthy correlation of the pancreatic head size, pancreatic tail size and the obesity degree as well as the disease duration was demonstrated. Postprandial pancreatic reaction was reduced in the most part of the patients with obesity (77%). Postprandial pancreatic reaction was more significantly reduced in the children with obesity and metabolic syndrome than in the children with obesity, who hasn't the signs of metabolic syndrome (15,3% and 7,5%). So, it is necessary the special examination of the children with obesity to reveal chronic pancreatitis.

The future of pancreatology: how to go where we have never been before

The current article is part of a series of manuscripts, which together serve as a never-perfect yet candid attempt to honor the remarkable scientific stature of Professor Hans Gunther Beger. The challenge posed to the author has been to meditate on the future of pancreatology. In the following paragraphs, to the exclusion of no other, we provide an approach to future discoveries in our field. This approach combines the large scope of the new biology (eg, genomics) with the analytical power of conventional, hypothesis-driven, molecular cell biology of individual laboratories to build comprehensive functional models of normal and diseased pancreatic cell populations. In addition, the potential challenges that both the size of our field and current research funding offer to scientists focused on the pancreas are discussed. It is the author's hope that the readers will not only meditate on the reflections offered here but, when in agreement with the positions stated, will help to implement a road map that can make our scientific field better. Never forget--the lives of our patients depend on what we do.

New pancreas from old: microregulators of pancreas regeneration

MicroRNAs (miRNAs) are 18-22 nucleotide RNA molecules that mediate post-transcriptional gene silencing, primarily by binding to the 3' untranslated region of their target mRNA. Several studies have demonstrated the role of miRNAs in mouse pancreas development (miR-124a, miR-503, miR-541, miR-214) as well as in insulin secretion (miR-375, miR-9). Pancreatic transcription factors that are temporally expressed during early pancreas development are re-expressed during pancreas regeneration following pancreatectomy in mice. The only exception to this is Neurogenin3 (NGN3). Here, we discuss recent evidence for miRNA-mediated silencing of ngn3, which inhibits endocrine cell development via the classical 'stem cell pathway' during mouse pancreatic regeneration, thereby favoring beta-cell regeneration.

Endoplasmic reticulum stress signaling in pancreatic beta-cells

Pancreatic beta-cells are specialized for the production and regulated secretion of insulin to control blood-glucose levels. Increasing evidence indicates that stress-signaling pathways emanating from the endoplasmic reticulum (ER) are important in the maintenance of beta-cell homeostasis. Under physiological conditions, ER stress signaling has beneficial effects on beta-cells. Timely and proper activation of ER stress signaling is crucial for generating the proper amount of insulin in proportion to the need for it. In contrast, chronic and strong activation of ER stress signaling has harmful effects, leading to beta-cell dysfunction and death. Therefore, to dissect the molecular mechanisms of beta-cell failure and death in diabetes, it is necessary to understand the complex network of ER stress-signaling pathways. This review focuses on the function of the ER stress-signaling network in pancreatic beta-cells.

Toward maximizing the success rates of human islet isolation: influence of donor and isolation factors

In order to make islet transplantation a therapeutic option for patients with diabetes there is an urgent need for more efficient islet cell processing to maximize islet recovery. Improved donor management, organ recovery techniques, implementation of more stringent donor criteria, and improved islet cell processing techniques may contribute to enhance organ utilization for transplantation. We have analyzed the effects of donor and islet processing factors on the success rate of human islet cell processing for transplantation performed at a single islet cell processing center. Islet isolation outcomes improved when vasopressors, and in particular pitressin, and steroids were used for the management of multiorgan donors. Higher islet yields were obtained from adult male donors, BMI >25 kg/m2, adequate glycemic control during hospital stay, and when the pancreas was retrieved by a local surgical team. Successful isolations were obtained in 58% of the cases when > or = 4 donor criteria were met, and even higher success rates (69%) were observed when considering > or = 5 criteria. Our data suggest that a sequential, integrated approach is highly desirable to improve the success rate of islet cell processing.

MTPA: A crustacean metallothionein that affects hepatopancreatic mitochondrial functions

Metallothioneins are cysteine-rich proteins, with a high capacity to bind metallic ions, and for which a precise biological role has not been established. Here we investigated the effects of MTPA, a metallothionein from the lobster Panulirus argus, on mitochondrial oxygen consumption and ROS production. An HPLC-RP-ESI-MS analysis of recombinant MTPA showed that despite its extra Cys, MTPA binds 6 Zn2+ per molecule akin to other crustacean metallothioneins with 18 Cys. The extra Cys is not involved in zinc binding, since its side-chain would be oriented to the outside of the molecule according to a preliminary model of the tridimensional structure of MTPA. MTPA-Zn2+(6) is imported into the hepatopancreatic mitochondria intermembrane space and inhibits mitochondrial oxygen consumption, increasing thereby ROS production. Nevertheless, the stimulation of ROS production by MT-bound Zn2+ is weaker compared to equivalent amounts of free Zn2+, suggesting that MTPA protects against oxidative stress. This constitutes the first report on metallothioneins effects on mitochondrial function in invertebrates and agrees with the results described for mammals, suggesting a connection between metallothioneins and energy metabolism.

Externally applied pressure activates pancreatic stellate cells through the generation of intracellular reactive oxygen species

Local tissue pressure is higher in chronic pancreatitis than in the normal pancreas. We reported recently that pressure application induces synthesis of extracellular matrix (ECM) and cytokines in pancreatic stellate cells (PSCs) and that epigallocatechin gallate (EGCG), a potent antioxidant, inhibits the transformation of PSCs from quiescent to activated phenotype and ethanol-induced synthesis of ECM and cytokines in PSCs. These results suggest that oxidative stress and reactive oxygen species (ROS) are important in PSC activation. The aim of this study was to clarify the effects of ROS on activation and functions of pressure-stimulated PSCs. We used freshly isolated rat PSCs and culture-activated PSCs. Pressure was applied on rat cultured PSCs by adding compressed helium gas into a pressure-loading apparatus. PSCs were cultured with or without antioxidants (EGCG and N-acetyl cysteine) under normal or elevated pressure. Externally applied high pressure (80 mmHg) resulted in a gradual decrease of superoxide dismutase activity in PSCs and increased intracellular ROS generation as early as 30 s, reaching a peak level at 1 h. Antioxidants significantly inhibited ROS generation. Pressure increased the expression levels of alpha-smooth muscle actin, alpha(1)(I)-procollagen, and TGF-beta1 in PSCs. EGCG suppressed these alterations, abolished pressure-induced phosphorylation of p38 MAPK, and suppressed pressure-induced PSC transformation to activated phenotype. Our results indicated that ROS is a key player in pressure-induced PSC activation and ECM synthesis. Antioxidants could be potentially effective against the development of pancreatic fibrosis in patients with chronic pancreatitis.

Pancreatic fat content and beta-cell function in men with and without type 2 diabetes

OBJECTIVE

Insulin resistance, associated with increased lipolysis, results in a high exposure of nonadipose tissue to lipids. Experimental data indicate that fatty infiltration of pancreatic islets may also contribute to beta-cell dysfunction, but whether this occurs in humans in vivo is unknown.

RESEARCH DESIGN AND METHODS

Using proton magnetic resonance spectroscopy and oral glucose tolerance tests, we studied the association of pancreatic lipid accumulation in vivo and various aspects of beta-cell function in 12 insulin-naive type 2 diabetic and 24 age- and BMI-matched nondiabetic men.

RESULTS

Patients versus control subjects had higher A1C, fasting plasma glucose, and insulin and triglyceride levels and lower HDL cholesterol, but similar waist circumference. Median (interquartile range) pancreatic fat content in patients and control subjects was 20.4% (13.4-43.6) and 9.7% (7.0-20.2), respectively (P = 0.032). Pancreatic fat correlated negatively with beta-cell function parameters, including the insulinogenic index adjusted for insulin resistance, early glucose-stimulated insulin secretion, beta-cell glucose sensitivity, and rate sensitivity (all P < 0.05), but not potentiation. However, these associations were significantly affected by the diabetic state, such that a significant association of pancreatic fat with beta-cell dysfunction was only present in the nondiabetic group (all P < 0.01), suggesting that once diabetes occurs, factors additional to pancreatic fat account for further beta-cell function decline. In control subjects, the association of pancreatic fat and beta-cell function remained significant after correction for BMI, fasting plasma glucose, and triglycerides (P = 0.006).

CONCLUSIONS

These findings indicate that pancreatic lipid content may contribute to beta-cell dysfunction and possibly to the subsequent development of type 2 diabetes in susceptible humans.

Caveats and considerations for performing pancreas-specific gene manipulations in the mouse

Conditional gene targeting using the Cre/loxP strategy has proven to be very useful for studies of glucose homeostasis, tissue function and dysfunction in diabetes, and pancreas development. However, use of this strategy over the past decade has revealed a variety of experimental caveats, many of which are a direct consequence of the procedures used to generate Cre-driver lines. We discuss frequently encountered experimental artefacts, the advantages of using bacterial artificial chromosome-derived transgenes or performing a Cre knockin for improving the specificity of expression, and systems for regulating Cre activity. In addition, recent studies indicate that high amounts of Cre in the pancreatic beta-cell may cause glucose intolerance and impaired insulin secretion. However, these findings, while serving as a reminder for simple experimental controls, are unlikely to diminish utilization of this very powerful and useful technology.

Upregulated expression of PDGF receptor beta in endocrine pancreatic tumors and metastases compared to normal endocrine pancreas

Platelet-derived growth factor receptor (PDGFR) beta signaling is involved in autocrine growth stimulation of tumor cells, tumor angiogenesis and regulation of tumor interstitial fluid pressure. Development of PDGFR antagonists has further increased the interest for PDGFR as targets for anticancer treatments. Malignant endocrine pancreatic tumors (EPTs) express PDGFR beta both in stroma and on tumor cells. To investigate the role of PDGFR beta signaling in EPTs we compared PDGFR beta expression in normal endocrine pancreas to malignant EPTs and metastases. PDGFR beta expression was examined by immunohistochemistry using specific polyclonal antibodies in ten tissue samples from normal endocrine pancreas, 21 from primary EPTs and 19 from metastases. In eight patients we compared the expression in normal endocrine pancreas to the corresponding primary tumor and metastases, in two patients normal tissue to the primary tumor and in 11 patients primary tumors to the corresponding metastases. Six of ten tissues containing normal pancreas stained negative for PDGFR beta on endocrine cells, while seven of ten stained positive in the stroma. Eighteen of 21 (86%) primary tumors stained positive for PDGFR beta on tumor cells and all had positive stroma stainings. All 19 metastases stained positive for PDGFR beta on tumor cells and in evaluable stroma (n=16). We have found that PDGFR beta is more frequently expressed in primary EPTs and metastases as compared to normal endocrine pancreatic tissue. This is also true for PDGFR beta expression in the corresponding stroma. We suggest that new therapeutic options to inhibit the growth and spread of EPTs could include targeting of PDGFR beta.

Pancreas transcription factor 1alpha expression is regulated in pancreatitis

BACKGROUND

Expression of acinar cell-specific genes requires the pancreas transcription factor 1alpha (Ptf1alpha). p48 is the only component of Ptf1alpha that is involved in both acinar gene regulation and pancreatic ontogenesis.

MATERIALS AND METHODS

To determine whether Ptf1alpha/p48 expression is regulated during pancreatitis, acute pancreatitis was induced in rats by repeated caerulein injections; early chronic pancreatitis by the combined administration of caerulein and cyclosporin A; and focal pancreas fibrosis by trinitrobenzene sulfonic acid infusion into the pancreatic duct. AR42J cells were used to examine caerulein effects on acinar cells. Ptf1alpha/p48 expression was examined using immunohistochemistry, Western blotting, and qRT-PCR methods.

RESULTS

In acute pancreatitis, Ptf1alpha/p48 decreased markedly within 6 h as determined by Western blotting and immunohistochemistry. After 24 h, Ptf1alpha/p48 increased continuously and normalized at day six. In contrast, pancreas amylase reached a nadir at 48 h, when Ptf1alpha/p48 had largely recovered. In the early chronic pancreatitis model Ptf1alpha/p48 levels did not completely recover even at day 14, and this was associated with a failure to restore normal histology and amylase content. qRT-PCR showed that p48 mRNA were reduced after pancreatitis induction and were followed by a decrease in elastase mRNA. In the focal pancreas fibrosis model, Ptf1alpha/p48 expression was undetectable in areas with substantial acinar cell loss and tubular complexes. Caerulein did not affect Ptf1alpha/p48 expression in AR42J cells.

CONCLUSIONS

Ptf1alpha/p48 protein and mRNA levels are regulated in acute and chronic experimental pancreatitis. Inability to re-express Ptf1alpha/p48 after injury may preclude acinar cell differentiation and appropriate pancreatic regeneration.

Pancreas and cystic fibrosis: the implications of increased survival in cystic fibrosis

Pancreatitis affects 0.5% people with cystic fibrosis (CF) in the UK and 0.01% of the normal population. Why do some with CF get pancreatitis and some not? And does pancreatitis in neonates result in pancreatic failure with no further inflammation or risk of pancreatic cancer? Review of the literature would suggest that 85% of those with CF have pancreatic destruction as children with minimal risk of further inflammatory or neoplastic changes. Those with a functioning pancreas are at risk of developing pancreatitis. There are several case series of pancreatic cancer reported in CF patients, but overall the risk is unknown. As patients with CF and pancreatic sufficiency are living longer, further studies to assess the risk of developing pancreatic cancer in this subgroup should be considered.

'In a certain sense Dr. William Osler has been my best mentor'. An interview with Prof. Tadashi Takeuchi by Martin E. Fernandez-Zapico

Tadashi Takeuchi is a Professor Emeritus of the Tokyo Women's Hospital University, one of the founders of the Japan Pancreas Society and first Editor-in-Chief of its official journal. His research contributed enormously to the understanding of the role of gastrointestinal hormones in pancreatic physiology as well as disease. In this interview, Professor Takeuchi discusses the importance of mentorship during career development.

Basics of TGF-beta and pancreatic cancer

Pancreatic cancer is the 4th leading cause of cancer-related death in the United States. The number of diagnoses per year equals the number of deaths per year, making it the deadliest of all malignancies. Modern advances and breakthroughs in molecular oncology have allowed researchers to gain a better understanding of the mechanisms responsible for the pathogenesis of this disease. The transforming growth factor-beta (TGF-beta) pathway is one of the signaling systems that has been identified as a major contributor. TGF-beta plays a paradoxical role as both a tumor suppressor and a tumor promoter in pancreatic cancer. The purpose of this review is to provide the practicing clinician a thorough review of this molecule and its associated signaling partners in the context of its duplicitous role and behavior in patients with pancreatic cancer.

Role of lumican in cancer cells and adjacent stromal tissues in human pancreatic cancer

Lumican is a member of a small leucine-rich proteoglycan family and its overexpression has been reported in carcinoid tumor, breast, colorectal, neuroendocrine cell, uterine cervical and pancreatic cancers. The expression of lumican in stromal tissues in breast cancer is associated with a high tumor grade, a low estrogen receptor expression level and young age. Lumican expression in the cytoplasm in advanced colorectal cancer is correlated with a poor prognosis. Lumican expression was previously reported in pancreatic cancer, but the role of lumican in pancreatic cancer is still not well understood. In this study, we aimed to clarify the role of lumican in pancreatic cancer. Reverse-transcription polymerase chain reaction and Western blot analyses revealed lumican mRNA and protein expression in six pancreatic ductal adenocarcinoma cell lines (i.e. PANC-1, MIA PaCa-2, KLM-1, Capan-1, PK-1 and PK-8). On the basis of its immunoreactivity, lumican was found to be localized in islet cells of normal pancreatic tissues, but not in exocrine cells. In pancreatic cancer tissues, lumican was predominantly localized in the cytoplasm of cancer cells in 30 out of 53 (56.6%) cancer patients, whereas lumican was detected in stromal tissues in 36 out of 53 (67.9%) cancer patients. Lumican expression in pancreatic cancer cells did not correlate with clinicopathological factors, whereas lumican expression in stromal tissues correlated with the female gender, advanced stage, retroperitoneal and duodenal invasion and residual tumor (p=0.030, 0.038, 0.049, 0.049 and 0.048, respectively). Patients with lumican-positive cancer cells tended to survive longer than those with lumican-negative cancer cells (p=0.286), but patients with lumican-positive stromal tissues had shorter survival than those with lumican-negative stromal tissues (p=0.062). These results suggest that lumican in stromal tissues plays an important role in the growth and invasion of pancreatic cancer.

Morphological localisation of sulfonylurea receptor 1 in endocrine cells of human, mouse and rat pancreas

AIMS/HYPOTHESIS

Sulfonylurea receptor 1 (SUR1) is the regulatory subunit of ATP-sensitive K channels in beta cells. Morphological methods (immunohistochemistry and sulfonylurea binding) were used to establish the cellular and subcellular location of SUR1 in human and rodent islets.

RESULTS

In the human, mouse and rat pancreas, all endocrine cells of the islets were immunolabelled with an anti-SUR1 antibody, whereas tissues containing SUR2 were consistently negative, as were those from Sur1 (also known as Abcc8)(-/-) mice. In beta cells of the three species, the plasma membrane was distinctly stained, but SUR1 was mainly present over the cytoplasm, with an intensity that varied between cells. Electron microscopy showed that SUR1 was immunolocalised in insulin, glucagon and somatostatin granules. In rat beta cells degranulated by in vivo treatment with glibenclamide (known as glyburide in the USA and Canada), the insulin and SUR1 staining intensity was similarly decreased by approximately 45%, whereas SUR1 staining was not changed in non-beta cells. In all islet cells, binding of glibenclamide labelled with fluorescent dipyrromethane boron difluoride (BODIPY-FL) was punctate over the cytoplasm, compatible with the labelling of endocrine granules. A faint labelling persisted in Sur1 (-/-) mice, but it was not different from that obtained with BODIPY-FL alone used as negative control.

CONCLUSIONS/INTERPRETATION

Our study immunolocalised SUR1 in alpha, beta and delta cells of human, mouse and rat islets, and for the first time visualised it in the plasma membrane. We also show that SUR1 is abundant in endocrine granules, where its function remains to be established. No specific sulfonylurea-binding sites other than SUR1 are identified in islet cells by the glibenclamide-BODIPY-FL technique.

[State of the abdominal organs and vessels on the background of simulated venous plethora in the splanchnic vascular system]

Ultrasonic investigations of the abdominal organs and splanchnic veins were performed in essentially healthy subjects tilted at 12 degrees and 15 degrees for the period of 12 hrs. and 24 hrs. Tilting produced typical redistribution of venous blood and body liquids toward the cranial end. In its turn, blood redistribution caused excessive venous plethora and abdominal stasis. These were succeeded by expansion of large veins in the abdomen, enlargement of parenchymal organs and contraction of their echogenicity, and thickening of the hollow organs walls. Changes in the gastrointestinal functions before meal included elevated gastric, hepatic and pancreatic secretion, and an increased amount of intestinal content. The investigations demonstrated that stasis of the splanchnic veins altered functioning of the digestive organs in tilted human subjects.

Decreased GABAA Receptor Function in the Brain Stem during Pancreatic Regeneration in Rats

Gamma amino butyric acid is a major inhibitory neurotransmitter in the central nervous system. In the present study we have investigated the alteration of GABA receptors in the brain stem of rats during pancreatic regeneration. Three groups of rats were used for the study: sham operated, 72 h and 7 days partially pancreatectomised. GABA was quantified by [(3)H]GABA receptor displacement method. GABA receptor kinetic parameters were studied by using the binding of [(3)H]GABA as ligand to the Triton X-100 treated membranes and displacement with unlabelled GABA. GABA(A) receptor activity was studied by using the [(3)H]bicuculline and displacement with unlabelled bicuculline. GABA content significantly decreased (P < 0.001) in the brain stem during the regeneration of pancreas. The high affinity GABA receptor binding showed a significant decrease in B(max) (P < 0.01) and K(d) (P < 0.05) in 72 h and 7 days after partial pancreatectomy. [(3)H]bicuculline binding showed a significant decrease in B(max) and K(d) (P < 0.001) in 72 h pancreatectomised rats when compared with sham where as B(max) and K(d) reversed to near sham after 7 days of pancreatectomy. The results suggest that GABA through GABA receptors in brain stem has a regulatory role during active regeneration of pancreas which will have immense clinical significance in the treatment of diabetes.

Association of maternal pancreatic function and foetal growth in rats treated with DFU, a selective cyclooxygenase-2 inhibitor

Constitutive (COX-1) and inducible (COX-2) cyclooxygenase isoforms have been detected in various mammalian tissues. Their activity is blocked by non-steroidal anti-inflammatory drugs that may induce various side reactions. The aim of the study was to evaluate the effects of DFU, a selective COX-2 inhibitor, on exocrine and endocrine pancreatic function and the immunoexpression of both COX isoforms in maternal and foetal rat pancreases. The compound was administered to pregnant Wistar rats once daily from the 8th to the 21st day of gestation. Glucose level and amylase activity were determined in the maternal sera. Maternal and foetal pancreases were examined histologically. Immunoexpression of COX-1 and COX-2 was also evaluated. Both biochemical parameters, as well as the histological structure of the pancreas were undisturbed in the dams and their foetuses. The maternal glucose level was found to be an important factor for foetal growth. Strong cytoplasmic COX-1 immunostaining was observed in acinar secretory cells, whereas in islets the immune reaction was weak. Endocrine cells also revealed strong cytoplasmic COX-2 staining in the maternal and foetal pancreases. Acinar cells exhibited nuclear reaction, which was strong in the foetal but weak in the maternal pancreases. No differences in COX immunoexpression were found between the DFU-exposed and the control groups in either mothers or foetuses. It should be stressed that DFU administered throughout mid and late pregnancy in rats did not change maternal or foetal pancreatic morphology or immunoexpression of either of the main COX isoforms in the organ.

Human fibroblast growth factor receptor 1-IIIb is a functional fibroblast growth factor receptor expressed in the pancreas and involved in proliferation and movement of pancreatic ductal cells

OBJECTIVES

The possible functions of the human IIIb-messenger RNA splice variant of fibroblast growth factor (FGF) receptor 1 (FGFR-1 IIIb) are yet to be delineated. In this study, the expression and functionality of the human FGFR-1 IIIb were characterized in the pancreas.

METHODS

In situ hybridization with a specific FGFR-1 IIIb probe in human pancreatic tissues demonstrated that FGFR-1 IIIb localized in normal pancreatic acinar and in ductal-like pancreatic cancer cells. To further assess the potential role of this receptor, a full-length human FGFR-1 IIIb was stably expressed in TAKA-1 pancreatic ductal cells not expressing endogenous FGFR-1.

RESULTS

The FGFR-1 IIIb-expressing TAKA-1 cells synthesized a glycosylated 110-kd protein capable of inducing proliferation on incubation with exogenous FGF-1, -2, and -4. These effects were paralleled by tyrosine phosphorylation of FGFR substrate 2 and association of FGFR substrate 2 with FGFR-1 IIIb. The FGF-1, -2, and -10 induced the activation of p44/42 mitogen-activated protein kinase (MAPK), p38 MAPK, and c-Jun N-terminal kinase. Pharmacological inhibition revealed that FGF-induced proliferation was dependent on the concomitant activation of p44/42 MAPK and c-Jun N-terminal kinase. The FGFR-1 IIIb expression enhanced single-cell movement and plating efficacy.

CONCLUSIONS

Our results demonstrate that the human FGFR-1 IIIb variant is a functional FGFR expressed in the pancreas that can alter pancreatic functions that regulate proliferation, adhesion, and movement.

Early expression of adenosine 5'-triphosphate-gated P2X7 receptors in the developing rat pancreas

OBJECTIVES

Extracellular adenosine 5'-triphosphate modulates the functions of the adult pancreas via 2 nucleotide receptor families, the P2X and P2Y receptors. Expression of the P2X7 receptor has been demonstrated in islet cells of the pancreas, particularly the mature alpha cells that secrete glucagon. In the streptozotocin-induced diabetic model, a loss of insulin-secreting cells was accompanied by an increase in alpha cells that expressed the P2X7 receptor.

METHODS

In the present study, we have examined the expression of P2X7 receptors in the developing pancreas from embryonic days 10 (E10) to E18.

RESULTS

We detected P2X7 receptor-immunoreactive cells in pancreatic islet cells as early as E11' before glucagon expression. Subsequently, P2X7 receptors were expressed in glucagon-secreting cells at E12, and complete colocalization was observed at E14. Occasional colocalization of P2X7 receptors and insulin was observed in scattered cells at E12 and E14, but not at E18, when the glucagon- and insulin-secreting cells were almost completely segregated.

CONCLUSIONS

It was found that P2X7 receptors were expressed early in a subpopulation of glucagon- and insulin-immunopositive cells in developing islets and subsequently became restricted to glucagon-expressing cells as development proceeded. The possible functional significance of these changes is discussed.

Characterisation of CART-containing neurons and cells in the porcine pancreas, gastro-intestinal tract, adrenal and thyroid glands

BACKGROUND

The peptide CART is widely expressed in central and peripheral neurons, as well as in endocrine cells. Known peripheral sites of expression include the gastrointestinal (GI) tract, the pancreas, and the adrenal glands. In rodent pancreas CART is expressed both in islet endocrine cells and in nerve fibers, some of which innervate the islets. Recent data show that CART is a regulator of islet hormone secretion, and that CART null mutant mice have islet dysfunction. CART also effects GI motility, mainly via central routes. In addition, CART participates in the regulation of the hypothalamus-pituitary-adrenal-axis. We investigated CART expression in porcine pancreas, GI-tract, adrenal glands, and thyroid gland using immunocytochemistry.

RESULTS

CART immunoreactive (IR) nerve cell bodies and fibers were numerous in pancreatic and enteric ganglia. The majority of these were also VIP IR. The finding of intrinsic CART containing neurons indicates that pancreatic and GI CART IR nerve fibers have an intrinsic origin. No CART IR endocrine cells were detected in the pancreas or in the GI tract. The adrenal medulla harboured numerous CART IR endocrine cells, most of which were adrenaline producing. In addition CART IR fibers were frequently seen in the adrenal cortex and capsule. The capsule also contained CART IR nerve cell bodies. The majority of the adrenal CART IR neuronal elements were also VIP IR. CART IR was also seen in a substantial proportion of the C-cells in the thyroid gland. The majority of these cells were also somatostatin IR, and/or 5-HT IR, and/or VIP IR.

CONCLUSION

CART is a major neuropeptide in intrinsic neurons of the porcine GI-tract and pancreas, a major constituent of adrenaline producing adrenomedullary cells, and a novel peptide of the thyroid C-cells. CART is suggested to be a regulatory peptide in the porcine pancreas, GI-tract, adrenal gland and thyroid.

'Do research with seriousness and perseverance'. An interview with Prof. Lucio Gullo. Interview by Martin E. Fernandez-Zapico

In the current interview Prof. Lucio Gullo, a worldwide-recognized pancreatologist for his contribution on the understanding of the pathogenesis and clinical aspects of a number of pancreatic diseases including benign pancreatic hyperenzymemia, shares with Pancreatology his life experiences as a scientist in pancreatic research.

Retinoic acid-mediated patterning of the pre-pancreatic endoderm in Xenopus operates via direct and indirect mechanisms

Early patterning of the endoderm as a prerequisite for pancreas specification involves retinoic acid (RA) as a critical signalling molecule in gastrula stage Xenopus embryos. In extension of our previous studies, we made systematic use of early embryonic endodermal and mesodermal explants. We find RA to be sufficient to induce pancreas-specific gene expression in dorsal but not ventral endoderm. The differential expression of retinoic acid receptors (RARs) in gastrula stage endoderm is important for the distinct responsiveness of dorsal versus ventral explants. Furthermore, BMP signalling, that is repressed dorsally, prevents the formation of pancreatic precursor cells in the ventral endoderm of gastrula stage Xenopus embryos. An additional requirement for mesoderm suggests the production of one or more further pancreas inducing signals by this tissue. Finally, recombination of manipulated early embryonic explants, and also inhibition of RA activity in whole embryos, reveal that RA signalling, as it is relevant for pancreas development, operates simultaneously on both mesodermal and endodermal germ layers.

Preexisting pancreatic acinar cells contribute to acinar cell, but not islet beta cell, regeneration

It has been suggested that pancreatic acinar cells can serve as progenitors for pancreatic islets, a concept with substantial implications for therapeutic efforts to increase insulin-producing beta cell mass in patients with diabetes. We report what we believe to be the first in vivo lineage tracing approach to determine the plasticity potential of pancreatic acinar cells. We developed an acinar cell-specific inducible Cre recombinase transgenic mouse, which, when mated with a reporter strain and pulsed with tamoxifen, resulted in permanent and specific labeling of acinar cells and their progeny. During various time periods of observation and using several models to provoke injury, we failed to observe any chase of the labeled cells into the endocrine compartment, indicating that acinar cells do not normally transdifferentiate into islet beta cells in vivo in adult mice. In contrast, we observed a substantial role for replication of preexisting acinar cells in the regeneration of new acinar cells after partial pancreatectomy. These results indicate that mature acinar cells harbor a facultative acinar but not endocrine progenitor capacity.

Putting pancreatic cell plasticity to the test

Diabetes results from the absolute or relative deficiency of insulin-producing beta cells. The prospect that non-beta pancreatic cells could be harnessed to become beta cells has led to interest in understanding the plasticity of pancreatic cells. Recent studies, however, have shown that adult beta cells are largely derived from preexisting beta cells. In this issue of the JCI, Desai et al. show that acinar cells, the major cell type in the pancreas, do not contribute to new beta cells formed during pancreatic regeneration (see the related article beginning on page 971). These studies suggest that the fate of adult pancreatic cell lineages is immutable. However, also in this issue of the JCI, Collombat et al. demonstrate that inducing a single transcription factor named Arx in adult beta cells causes these cells to undergo massive transdifferentiation into alpha and pancreatic polypeptide endocrine cells (see the related article beginning on page 961). This finding points to an unexpected plasticity of postnatal pancreatic endocrine cells.

Pancreatic deletion of insulin receptor substrate 2 reduces beta and alpha cell mass and impairs glucose homeostasis in mice

AIMS/HYPOTHESIS

Insulin signalling pathways regulate pancreatic beta cell function. Conditional gene targeting using the Cre/loxP system has demonstrated that mice lacking insulin receptor substrate 2 (IRS2) in the beta cell have reduced beta cell mass. However, these studies have been complicated by hypothalamic deletion when the RIPCre (B6.Cg-tg(Ins2-cre)25Mgn/J) transgenic mouse (expressing Cre recombinase under the control of the rat insulin II promoter) is used to delete floxed alleles in insulin-expressing cells. These features have led to marked insulin resistance making the beta cell-autonomous role of IRS2 difficult to determine. To establish the effect of deleting Irs2 only in the pancreas, we generated PIrs2KO mice in which Cre recombinase expression was driven by the promoter of the pancreatic and duodenal homeobox factor 1 (Pdx1, also known as Ipf1) gene.

MATERIALS AND METHODS

In vivo glucose homeostasis was examined in PIrs2KO mice using glucose tolerance and glucose-stimulated insulin secretion tests. Endocrine cell mass was determined by morphometric analysis. Islet function was examined in static cultures and by performing calcium imaging in Fluo3am-loaded beta cells. Islet gene expression was determined by RT-PCR.

RESULTS

The PIrs2KO mice displayed glucose intolerance and impaired glucose-stimulated insulin secretion in vivo. Pancreatic insulin and glucagon content and beta and alpha cell mass were reduced. Glucose-stimulated insulin secretion and calcium mobilisation were attenuated in PIrs2KO islets. Expression of the Glut2 gene (also known as Slc2a2) was also reduced in PIrs2KO mice.

CONCLUSIONS/INTERPRETATION

These studies suggest that IRS2-dependent signalling in pancreatic islets is required not only for the maintenance of normal beta and alpha cell mass but is also involved in the regulation of insulin secretion.

EUS elastography of the pancreas: feasibility and pattern description of the normal pancreas, chronic pancreatitis, and focal pancreatic lesions

BACKGROUND

Initial clinical applications have shown that US elastography might be able to distinguish tissues because of their specific consistency.

OBJECTIVE

(1) To investigate the feasibility of EUS elastography of the pancreas and (2) to describe elastographic patterns of the normal pancreas and the pancreas affected by inflammatory or focal disease.

DESIGN

Prospective single-center study.

SETTING

Academic center of the University of Witten/Herdecke.

PATIENTS

Twenty patients with normal pancreas, 20 patients with chronic pancreatitis, and 33 patients with focal pancreatic lesion, histologically later proven in 32 of these 33 cases.

INTERVENTIONS

Commercially available US equipment was used. The elasticity of tissue was reconstructed in real time within a sample area and was translated into a color scale imaging relative tissue elasticity within this area. Representative loops of at least 20 seconds were recorded regarding each region of interest.

RESULTS

Adequate elastographic recordings could be obtained in all 73 patients. Patients with hypoechoic and intermediately echogenic normal pancreas revealed a relatively homogeneous elastographic pattern. Thirty-one focal lesions, including 30 neoplasms and most of the chronically inflamed pancreata had a honeycomb pattern dominated by hard strands. This pattern showed analogies to the histologic structure of 10 resected tumors. Other patients with chronic pancreatitis and those with hyperechoic healthy pancreas had miscellaneous elastographic appearances.

CONCLUSIONS

EUS elastography of the pancreas is feasible and produces plausible results. The examination of homogeneous tissue is impaired by the relative scale used. Chronic pancreatitis and hard tumors cannot be distinguished by elastography, probably because of their similar fibrous structure.

Directed differentiation of human embryonic stem cells towards a pancreatic cell fate

AIMS/HYPOTHESIS

The relative lack of successful pancreatic differentiation of human embryonic stem cells (hESCs) may suggest that directed differentiation of hESCs into definitive endoderm and subsequent commitment towards a pancreatic fate are not readily achieved. The aim of this study was to investigate whether sequential exposure of hESCs to epigenetic signals that mimic in vivo pancreatic development can efficiently generate pancreatic endodermal cells, and whether these cells can be further matured and reverse hyperglycaemia upon transplantation.

MATERIALS AND METHODS

The hESCs were sequentially treated with serum, activin and retinoic acid (RA) during embryoid body formation. The patterns of gene expression and protein production associated with embryonic germ layers and pancreatic endoderm were analysed by RT-PCR and immunostaining. The developmental competence and function of hESC-derived PDX1-positive cells were evaluated after in vivo transplantation.

RESULTS

Sequential treatment with serum, activin and RA highly upregulated the expression of the genes encoding forkhead box protein A2 (FOXA2), SRY-box containing gene 17 (SOX17), pancreatic and duodenal homeobox 1 (PDX1) and homeobox HB9 (HLXB9). The population of pancreatic endodermal cells that produced PDX1 was significantly increased at the expense of ectodermal differentiation, and a subset of the PDX1-positive cells also produced FOXA2, caudal-type homeobox transcription factor 2 (CDX2), and nestin (NES). After transplantation, the PDX1-positive cells further differentiated into mature cell types producing insulin and glucagon, resulting in amelioration of hyperglycaemia and weight loss in streptozotocin-treated diabetic mice.

CONCLUSIONS/INTERPRETATION

Our strategy allows the progressive differentiation of hESCs into pancreatic endoderm capable of generating mature pancreatic cell types that function in vivo. These findings may establish the basis of further investigations for the purification of transplantable islet progenitors derived from hESCs.

Tocotrienols induce apoptosis and autophagy in rat pancreatic stellate cells through the mitochondrial death pathway

BACKGROUND & AIMS

Selective removal of activated pancreatic stellate cells (PSCs) through induction of their own programmed death is a goal of therapeutic interest in patients with chronic pancreatitis. Here, we investigated the effects of tocotrienols on PSC death outcomes.

METHODS

Activated and quiescent PSCs and acinar cells from rat pancreas were treated with vitamin E derivatives alpha-tocopherol; individual alpha-, beta-, gamma-, and delta-tocotrienols; and a tocotrienol rich fraction (TRF) from palm oil.

RESULTS

TRF, but not alpha-tocopherol, reduced viability of activated PSC by setting up a full death program, independent of cell cycle regulation. Activated PSCs died both through apoptosis, as indicated by increased DNA fragmentation and caspase activation, and through autophagy, as denoted by the formation of autophagic vacuoles and LC3-II accumulation. In contrast to alpha-tocopherol, TRF caused an intense and sustained mitochondrial membrane depolarization and extensive cytochrome c release. Caspase inhibition with zVAD-fmk suppressed TRF-induced apoptosis but enhanced autophagy. However, mitochondrial permeability transition pore blockade with cyclosporin A completely abolished the deadly effects of TRF. beta-, gamma-, and delta-tocotrienol, but not alpha-tocotrienol nor alpha-tocopherol, reproduced TRF actions on activated PSCs. TRF death induction was restricted to activated PSCs because it did not cause apoptosis either in quiescent PSCs or in acinar cells.

CONCLUSIONS

Tocotrienols selectively trigger activated pancreatic stellate cell death by targeting the mitochondrial permeability transition pore. Our findings unveil a novel potential for tocotrienols to ameliorate the fibrogenesis associated with chronic pancreatitis.

Cloning, expression, and functional characterization of zebrafish Mist1

The basic helix-loop-helix (bHLH) protein Mist1 is an important exocrine pancreas transcriptional factor expressed in the acinar cells of mammals. In the present study, we cloned the homologous Mist1 cDNA encoding a predicted protein of 184 amino acids in zebrafish. The typical bHLH domain of zebrafish Mist1 shares high identity with that of its orthologs in mouse, rat, and human. Expression analysis revealed that Mist1 maternal transcripts are distinct in the very beginning of embryogenesis and that endogenous Mist1 is chronologically expressed in polster, hatching gland, hindbrain and appears exclusively in the pancreas from 72 hpf onward. Knockdown of Mist1 conditionally causes mild morphological defects in embryos. In MO-treated embryos, midbrain-hindbrain boundary is missing and exocrine pancreas is significantly reduced and disorganized. These results suggest that Mist1 functions in an evolutionary conserved way as a key transcriptional regulator specific for exocrine pancreas development in zebrafish.

Pharmacological inhibition of glucosylceramide synthase enhances insulin sensitivity

A growing body of evidence implicates ceramide and/or its glycosphingolipid metabolites in the pathogenesis of insulin resistance. We have developed a highly specific small molecule inhibitor of glucosylceramide synthase, an enzyme that catalyzes a necessary step in the conversion of ceramide to glycosphingolipids. In cultured 3T3-L1 adipocytes, the iminosugar derivative N-(5'-adamantane-1'-yl-methoxy)-pentyl-1-deoxynojirimycin (AMP-DNM) counteracted tumor necrosis factor-alpha-induced abnormalities in glycosphingolipid concentrations and concomitantly reversed abnormalities in insulin signal transduction. When administered to mice and rats, AMP-DNM significantly reduced glycosphingolipid but not ceramide concentrations in various tissues. Treatment of ob/ob mice with AMP-DNM normalized their elevated tissue glucosylceramide levels, markedly lowered circulating glucose levels, improved oral glucose tolerance, reduced A1C, and improved insulin sensitivity in muscle and liver. Similarly beneficial metabolic effects were seen in high fat-fed mice and ZDF rats. These findings provide further evidence that glycosphingolipid metabolites of ceramide may be involved in mediating the link between obesity and insulin resistance and that interference with glycosphingolipid biosynthesis might present a novel approach to the therapy of states of impaired insulin action such as type 2 diabetes.

Control of beta-cell differentiation by the pancreatic mesenchyme

The importance of mesenchymal-epithelial interactions for normal development of the pancreas was recognized in the early 1960s, and mesenchymal signals have been shown to control the proliferation of early pancreatic progenitor cells. The mechanisms by which the mesenchyme coordinates cell proliferation and differentiation to produce the normal number of differentiated pancreatic cells are not fully understood. Here, we demonstrate that the mesenchyme positively controls the final number of beta-cells that develop from early pancreatic progenitor cells. In vitro, the number of beta-cells that developed from rat embryonic pancreatic epithelia was larger in cultures with mesenchyme than without mesenchyme. The effect of mesenchyme was not due to an increase in beta-cell proliferation but was due to increased proliferation of early pancreatic duodenal homeobox-1 (PDX1)-positive progenitor cells, as confirmed by bromodeoxyuridine incorporation. Consequently, the window during which early PDX1(+) pancreatic progenitor cells differentiated into endocrine progenitor cells expressing Ngn3 was extended. Fibroblast growth factor 10 mimicked mesenchyme effects on proliferation of early PDX1(+) progenitor cells and induction of Ngn3 expression. Taken together, our results indicate that expansion of early PDX1(+) pancreatic progenitor cells represents a way to increase the final number of beta-cells developing from early embryonic pancreas.

[Neurotrophic control in the development and function of two endocrine organs: the ovary and the pancreas]

Neurotrophins (NTs) are important for the survival, differentiation and function of sympathetic and sensorial neurons of central and peripheral nervous system. However, similar functions have been described of NTs in non-neural organs. Nerve Growth factor (NGF) participates in the foliculogenesis and ovulation in the ovary, as well as in the islet morphogenesis and insulin secretion of the pancreatic beta cell. The NTs act by binding to two distinct classes of transmembranal receptors: p75 and Trks. Both receptor types lead to activation of intracellular signaling cascades that end with cell survival or apoptosis. In this review different actions of the NTs in the ovarian and the pancreas are described.

The role of Islet Neogenesis-Associated Protein (INGAP) in islet neogenesis

Islet Neogenesis-Associated Protein (INGAP) is a member of the Reg family of proteins implicated in various settings of endogenous pancreatic regeneration. The expression of INGAP and other RegIII proteins has also been linked temporally and spatially with the induction of islet neogenesis in animal models of disease and regeneration. Furthermore, administration of a peptide fragment of INGAP (INGAP peptide) has been demonstrated to reverse chemically induced diabetes as well as improve glycemic control and survival in an animal model of type 1 diabetes. Cultured human pancreatic tissue has also been shown to be responsive to INGAP peptide, producing islet-like structures with function, architecture and gene expression matching that of freshly isolated islets. Likewise, studies in normoglycemic animals show evidence of islet neogenesis. Finally, recent clinical studies suggest an effect of INGAP peptide to improve insulin production in type 1 diabetes and glycemic control in type 2 diabetes.

Tissue characterization using dimensionality reduction and fluorescence imaging

Multidimensional fluorescence imaging is a powerful molecular imaging modality that is emerging as an important tool in the study of biological tissues. Due to the large volume of multi-spectral data associated with the technique, it is often difficult to find the best combination of parameters to maximize the contrast between different tissue types. This paper presents a novel framework for the characterization of tissue compositions based on the use of time resolved fluorescence imaging without the explicit modeling of the decays. The composition is characterized through soft clustering based on manifold embedding for reducing the dimensionality of the datasets and obtaining a consistent differentiation scheme for determining intrinsic constituents of the tissue. The proposed technique has the benefit of being fully automatic, which could have significant advantages for automated histopathology and increasing the speed of intraoperative decisions. Validation of the technique is carried out with both phantom data and tissue samples of the human pancreas.

Generation and characterization of novel tetracycline-inducible pancreatic transcription factor-expressing murine embryonic stem cell lines

Pancreatic development in mammals is controlled in part by the expression and function of numerous genes encoding transcription factors. Yet, how these regulate each other and their target genes is incompletely understood. Embryonic stem (ES) cells have recently been shown to be capable of differentiating into pancreatic progenitor cells and insulin-producing cells, representing a useful in vitro model system for studying pancreatic and islet development. To generate tools to study the relationships of transcription factors in pancreatic development we have established seven unique mouse ES cell lines with tetracycline-inducible expression of either Hnf4alpha, Hnf6, Nkx2.2, Nkx6.1, Pax4, Pdx1, and Ptf1a cDNAs. Each of the cell lines was characterized for induction of transgene expression after exposure to doxycycline (DOX) by quantitative real-time PCR and immunofluorescence microscopy. Transgene expression in the presence of DOX was at least 97-fold that seen in untreated cells. Immunofluorescent staining of DOX-treated cultures showed efficient (>95% of cells) transgene protein expression while showing <5% positive staining in uninduced cells. Each of the ES cell lines maintained their pluripotency as measured by teratoma formation. Furthermore, transgene expression can be efficiently achieved in vivo through DOX administration to mice. The establishment of ES cell lines with temporally controllable induction of critical pancreatic transcription factor genes provides a new set of tools that could be used to interrogate gene regulatory networks in pancreatic development and potentially generate greater numbers of beta cells from ES cells.

Ptf1a binds to and activates area III, a highly conserved region of the Pdx1 promoter that mediates early pancreas-wide Pdx1 expression

The critical pancreatic transcription factor Pdx1 is expressed throughout the pancreas early but enriched in insulin-producing beta cells postnatally. Previous studies showed that the 5' conserved promoter regions areas I and II (Pdx1(PB)) direct endocrine cell expression, while an adjacent region (Pdx1(XB)) containing conserved area III directs transient beta-cell expression. In this study, we used Cre-mediated lineage tracing to track cells that activated these regions. Pdx1(PB)Cre mediated only endocrine cell recombination, while Pdx1(XB)Cre directed broad and early recombination in the developing pancreas. Also, a reporter transgene containing areas I, II, and III was expressed throughout the embryonic day 10.5 (E10.5) pancreas and gradually became beta cell enriched, similar to endogenous Pdx1. These data suggested that sequences within area III mediate early pancreas-wide Pdx1 expression. Area III contains a binding site for PTF1, a transcription factor complex essential for pancreas development. This site contributed to area III-dependent reporter gene expression in the acinar AR42J cell line, while PTF1 specifically trans-activated area III-containing reporter expression in a nonpancreatic cell line. Importantly, Ptf1a occupied sequences spanning the endogenous PTF1 site in area III of E11.5 pancreatic buds. These data strongly suggest that PTF1 is an important early activator of Pdx1 in acinar and endocrine progenitor cells during pancreas development.

Pylorus-preserving pancreatoduodenectomy: preoperative pancreatic function and outcome

BACKGROUND/AIMS

To investigate the effects of preoperative pancreatic function on gastric emptying, body weight, and quality of life after pylorus-preserving pancreatoduodenectomy.

METHODOLOGY

Thirty-one patients who underwent pylorus-preserving pancreatoduodenectomy were divided into 2 groups according to preoperative pancreatic exocrine and endocrine function (normal vs. abnormal). Gastric emptying, body weight, and quality of life were evaluated before surgery, 1-2 months after surgery (short-term), and 6-12 months after surgery (long-term).

RESULTS

Short-term body weight was significantly decreased in comparison to preoperative body weight regardless of preoperative exocrine and endocrine pancreatic function. Body weight returned to the preoperative level by 12 months after surgery in patients with normal preoperative pancreatic function but not in patients with abnormal pancreatic function. In both groups, gastric emptying was delayed at 1-2 months after surgery and then returned to the preoperative value by 12 months. Short-term quality of life did not differ from preoperative quality of life in either group, but long-term quality of life improved to beyond the preoperative level in both groups.

CONCLUSIONS

Preoperative pancreatic function appears to significantly influence long-term body weight after pylorus-preserving pancreatoduodenectomy.