The endocrine pancreas in chronic pancreatitis. Immunocytochemical and ultrastructural studies

Diabetes of the Exocrine Pancreas: Implications for Pharmacological Management

Post-pancreatitis diabetes mellitus, pancreatic cancer-related diabetes, and cystic fibrosis-related diabetes are often underappreciated. As a result, a substantial proportion of people with these sub-types of diabetes receive antidiabetic medications that may be suboptimal, if not harmful, in the context of their underlying disease of the exocrine pancreas. The present article delineates both classical (biguanides, insulin, sulfonylureas, α-glucosidase inhibitors, thiazolidinediones, and meglitinides) and newer (glucagon-like peptide-1 receptor agonists, amylin analogs, dipeptidyl peptidase-4 inhibitors, sodium-glucose co-transporter-2 inhibitors, D2 receptor agonists, bile acid sequestrants, and dual glucagon-like peptide-1 receptor and glucose-dependent insulinotropic polypeptide receptor co-agonists) therapies and provides recommendations for managing people with diabetes of the exocrine pancreas based on the most up-to-date clinical evidence. Also, several emerging directions (lipid-enriched pathways, Y4 receptor agonism, glucagon-like peptide-1 and glucagon receptor co-agonism) are presented with a view to informing the process of new drug discovery and development.

Pancreatic polypeptide revisited: Potential therapeutic effects in obesity-diabetes

Pancreatic polypeptide (PP), a member of the neuropeptide Y (NPY) family of peptides, is a hormone secreted from the endocrine pancreas with established actions on appetite regulation. Thus, through activation of hypothalamic neuropeptide Y4 (NPY4R or Y4) receptors PP induces satiety in animals and humans, suggesting potential anti-obesity actions. In addition, despite being actively secreted from pancreatic islets and evidence of local Y4 receptor expression, PP mediated effects on the endocrine pancreas have not been fully elucidated. To date, it appears that PP possesses an acute insulinostatic effect, similar to the impact of other peptides from the NPY family. However, it is interesting that prolonged activation of pancreatic Y1 receptors leads to established benefits on beta-cell turnover, preservation of beta-cell identity and improved insulin secretory responsiveness. This may hint towards possible similar anti-diabetic actions of sustained Y4 receptor modulation, since the Y1 and Y4 receptors trigger comparable cell signalling pathways. In terms of exploiting the prospective therapeutic promise of PP, this is severely restricted by a short circulating half-life as is the case for many regulatory peptide hormones. It follows that long-acting, enzyme resistant, forms of PP will be required to determine viability of the Y4 receptor as an anti-obesity and -diabetes drug target. The current review aims to refocus interest on the biology of PP and highlight opportunities for therapeutic development.

Molecular signaling in pancreatic ductal metaplasia: emerging biomarkers for detection and intervention of early pancreatic cancer

Pancreatic ductal metaplasia (PDM) is the transformation of potentially various types of cells in the pancreas into ductal or ductal-like cells, which eventually replace the existing differentiated somatic cell type(s). PDM is usually triggered by and manifests its ability to adapt to environmental stimuli and genetic insults. The development of PDM to atypical hyperplasia or dysplasia is an important risk factor for pancreatic intraepithelial neoplasia (PanIN) and pancreatic ductal adenocarcinoma (PDA). Recent studies using genetically engineered mouse models, cell lineage tracing, single-cell sequencing and others have unraveled novel cellular and molecular insights in PDM formation and evolution. Those novel findings help better understand the cellular origins and functional significance of PDM and its regulation at cellular and molecular levels. Given that PDM represents the earliest pathological changes in PDA initiation and development, translational studies are beginning to define PDM-associated cell and molecular biomarkers that can be used to screen and detect early PDA and to enable its effective intervention, thereby truly and significantly reducing the dreadful mortality rate of PDA. This review will describe recent advances in the understanding of PDM biology with a focus on its underlying cellular and molecular mechanisms, and in biomarker discovery with clinical implications for the management of pancreatic regeneration and tumorigenesis.

Outcomes of Islet Autotransplantation in Chronic Pancreatitis Patients with Complete Acinar Atrophy

Total pancreatectomy with islet autotransplantation (TPIAT) is a promising treatment for refractory chronic pancreatitis (CP). Pathological features of CP include progressive fibrosis in pancreas parenchyma, atrophy, and/or ductal occlusion. Complete acinar atrophy (CAA) caused by chronic fibrosis and necroinflammation results in exocrine sufficiency and may influence islet isolation characteristics during TPIAT. In this analysis of patients who underwent TPIAT at our center, we compared transplant outcomes among those with CAA (n = 5) vs non-acinar atrophy (NAA; matching controls, n = 36). Data were analyzed using one-way analysis of variance with Bonferroni post hoc test or Student's t test. Pancreas digestion was longer in CAA than in NAA cases (18.6 vs 14.6 min) despite a lower pancreas weight (55.2 vs 91.2 g). Obtained tissue volume was 1.0 ml in the CAA group and 12.1 ml in the NAA group. Both groups had similar islet viability (96%) and islet dose (CAA, 3,391 IEQ/kg; NAA, 4141.1 IEQ/kg). During islet infusion, serum cytokine (IL-6, IL-8, and MCP-1) levels and plasma hsa-miR-375 levels were lower in the CAA group than in the NAA group, but not significantly. Serum tumor necrosis factor α levels at 3 h after infusion were significantly higher in CAA group than in NAA group. After TPIAT, the metabolic outcomes of the CAA group were comparable with that of the NAA group. Narcotics usage decreased significantly over 24 months in both groups, with the CAA group reporting being pain free at 12 months. Complete atrophy of acinar cells of pancreas did not significantly impact islet yield or endocrine function after TPIAT.

Pilot study examining the impact of a specialist multidisciplinary team clinic for patients with chronic pancreatitis

OBJECTIVE

-To assess the efficacy of a pilot Chronic Pancreatitis (CP) Multidisciplinary (MDT) clinic.

METHODS

- 60 patients referred to a pilot MDT CP clinic were analysed. Anthropometric data, nutrition status, malabsorption evidence, glycaemic control, opiate use, bone mineral density (BMD) assessment and quality of life (QoL) were examined.

RESULTS

-The average age was 51.27 (±12.75). The commonest aetiology was alcohol (55%). Ninety one point five percent had evidence of ongoing pancreatic exocrine insufficiency, with 88.1% requiring initiation or up-titration of pancreatic enzyme replacement (PERT). Up to half of the patients exhibited micronutrient deficiency. Twenty eight percent were diagnosed with type IIIc diabetes. There was an average daily reduction of 6 mg of morphine usage per patient with a concurrent decline in median pain scores from 83.3 to 63.3, which was non-significant. The median QoL score was 33.3 compared to a score of 75 from the reference population. QoL scores increased from 31.0 to 37.3 at follow up appointments. Seventy two point five percent of patients had undiagnosed low BMD.

CONCLUSION

The data suggest that CP patients have significant nutritional deficiencies as well as undiagnosed diabetes, poor pain and glycaemic control which negatively impacts QoL. Assessment in a multi-disciplinary clinic ensures appropriate management.

Pancreatic Islet Changes in Human Whole Organ Pancreas Explants: What Can Be Learned From Explanted Samples?

Background.

Whole pancreas transplantation (Tx) is a successful treatment for type 1 diabetes resulting in independence from antidiabetic therapies. Transplant-related factors contributing to pancreatic islet failure are largely unknown; both recurring insulitis and pancreatitis have been implicated. The aim was to determine if cellular changes in islets and exocrine tissue are evident early in Tx, which could contribute to eventual graft failure using well-preserved tissue of grafts explanted from largely normoglycemic recipients.

Methods.

Histological specimens of explants (n = 31), Tx duration 1 day–8 years (median 29 d), cold ischemia time 7.2–17.3 hours (median 11.1 h), donor age 13–54 years (median 38 y) were examined; sections were labeled for inflammation, islet amyloidosis, and tissue fibrosis, and morphometry performed on immunolabeled insulin and glucagon positive islet cells. Data were related to clinical details of donor, recipient, and features of Tx.

Results.

Islet inflammation consistent with recurrent insulitis was not seen in any sample. Insulin-labeled islet cell proportion decreased with donor age (P < 0.05) and cold ischemia (P < 0.01) in explants from 26 normoglycemic patients; glucagon-labeled area proportion increased with cold ischemia (P < 0.05). Clinical pancreatitis was the explant reason in 12 of 28 normoglycemic cases. Exocrine fibrotic area/pancreas was variable (0.7%–55%) and unrelated to clinical/pathological features. Islet amyloid was present in 3 normoglycemic cases (donor ages 58, 42, and 31 y; Tx duration 8 y, 31 and 33 d, respectively). In 1 patient receiving antidiabetic therapy, the insulin-labeled area was reduced but with no evidence of islet inflammation.

Conclusions.

Explant histological changes after short-term Tx are similar to those seen in type 2 diabetes and occur in the absence of immunologic rejection without causing hyperglycemia. This suggests that factors associated with Tx affect islet stability; persistent deterioration of islet integrity and exocrine tissue fibrosis could impact on sustainability of islet function.

A tale of two pancreases: exocrine pathology and endocrine dysfunction

The islets of Langerhans are well embedded within the exocrine pancreas (the latter comprised of ducts and acini), but the nature of interactions between these pancreatic compartments and their role in determining normal islet function and survival are poorly understood. However, these interactions appear to be critical, as when pancreatic exocrine disease occurs, islet function and insulin secretion frequently decline to the point that diabetes ensues, termed pancreatogenic diabetes. The most common forms of pancreatogenic diabetes involve sustained exocrine disease leading to ductal obstruction, acinar inflammation, and fibro-fatty replacement of the exocrine pancreas that predates the development of dysfunction of the endocrine pancreas, as seen in chronic pancreatitis-associated diabetes and cystic fibrosis-related diabetes and, more rarely, MODY type 8. Intriguingly, a form of tumour-induced diabetes has been described that is associated with pancreatic ductal adenocarcinoma. Here, we review the similarities and differences among these forms of pancreatogenic diabetes, with the goal of highlighting the importance of exocrine/ductal homeostasis for the maintenance of pancreatic islet function and survival and to highlight the need for a better understanding of the mechanisms underlying these diverse conditions. Graphical abstract.

Type-3c Diabetes Mellitus, Diabetes of Exocrine Pancreas - An Update

BACKGROUND

The incidence of diabetes is increasing steeply; the number of diabetics has doubled over the past three decades. Surprisingly, the knowledge of type 3c diabetes mellitus (T3cDM) is still unclear to the researchers, scientist and medical practitioners, leading towards erroneous diagnosis, which is sometimes misdiagnosed as type 1 diabetes mellitus (T1DM), or more frequently type 2 diabetes mellitus (T2DM). This review is aimed to outline recent information on the etiology, pathophysiology, diagnostic procedures, and therapeutic management of T3cDM patients.

METHODS

The literature related to T3cDM was thoroughly searched from the public domains and reviewed extensively to construct this article. Further, existing literature related to the other forms of diabetes is reviewed for projecting the differences among the different forms of diabetes. Detailed and updated information related to epidemiological evidence, risk factors, symptoms, diagnosis, pathogenesis and management is structured in this review.

RESULTS

T3cDM is often misdiagnosed as T2DM due to the insufficient knowledge differentiating between T2DM and T3cDM. The pathogenesis of T3cDM is explained which is often linked to the history of chronic pancreatitis, pancreatic cancer. Inflammation, and fibrosis in pancreatic tissue lead to damage both endocrine and exocrine functions, thus leading to insulin/glucagon insufficiency and pancreatic enzyme deficiency.

CONCLUSION

Future advancements should be accompanied by the establishment of a quick diagnostic tool through the understanding of potential biomarkers of the disease and newer treatments for better control of the diseased condition.

Glucose homeostasis dependency on acini-islet-acinar (AIA) axis communication: a new possible pathophysiological hypothesis regarding diabetes mellitus

Studies have highlighted the existence of two intra-pancreatic axes of communication: one involved in the regulation of enzyme production by insulin-the insular-acinar axis; and another involved in the regulation of insulin release by pancreatic enzymes-the acini-insular axis. Previous studies by our laboratory show that pancreatic enzymes can affect blood glucose homeostasis and insulin secretion independently of their digestive functions, both from the gut lumen and probably from the blood. As a result we would like to introduce here the concept of acini-islet-acinar (AIA) axis communication (feedback), which could play an important role in the development of obesity and diabetes type 2. The AIA feedback links the endocrine and exocrine parts of the pancreas and emphasizes the essential role that the pancreas plays, as a single organ, in the regulation of glucose homeostasis by amylase most probably in gut epithelium and by insulin and glucagon in peripheral blood.

An Increase in Chromogranin A-Positive, Hormone-Negative Endocrine Cells in Pancreas in Cystic Fibrosis

We sought to establish whether an increase in chromogranin A-positive, hormone-negative (CPHN) endocrine cells occurs in the pancreas of patients with cystic fibrosis (CF), as potential evidence of neogenesis. Pancreata were obtained at autopsy from nondiabetic patients with CF (n = 12) and age-matched nondiabetic control subject (CS) individuals without CF (n = 12). In addition, pancreas from three diabetic patients with CF was obtained. Pancreas sections were stained for chromogranin A, insulin, and a cocktail of glucagon, somatostatin, pancreatic polypeptide, and ghrelin and evaluated for the frequency of CPHN cells. There was a higher frequency of CPHN cells in islets of the patients with CF compared with the CS group. Moreover, CPHN cells occurring as single cells or clusters scattered in the exocrine pancreas were also more frequent in patients with CF. The increased frequency of CPHN cells in pancreas of patients with CF may indicate an attempt at endocrine cell regeneration.

Increased Chromogranin A-Positive Hormone-Negative Cells in Chronic Pancreatitis

CONTEXT

Chronic pancreatitis (CP) is characterized by inflammation, fibrosis, and a loss of pancreatic acinar cells, which can result in exocrine and eventually endocrine deficiency. Pancreatitis has been reported to induce formation of new endocrine cells (neogenesis) in mice. Our recent data have implicated chromogranin A-positive hormone-negative (CPHN) cells as potential evidence of neogenesis in humans.

OBJECTIVE

We sought to establish if CPHN cells were more abundant in CP in humans.

DESIGN, SETTING, AND PARTICIPANTS

We investigated the frequency and distribution of CPHN cells and the expression of the chemokine C-X-C motif ligand 10 (CXCL10) and its receptor chemokine C-X-C motif receptor 3 in pancreas of nondiabetic subjects with CP.

RESULTS

CPHN cell frequency in islets was increased sevenfold in CP [2.1% ± 0.67% vs 0.35% ± 0.09% CPHN cells in islets, CP vs nonpancreatitis (NP), P < 0.01], as were the CPHN cells found as scattered cells in the exocrine areas (17.4 ± 2.9 vs 4.2 ± 0.6, CP vs NP, P < 0.001). Polyhormonal endocrine cells were also increased in CP (2.7 ± 1.2 vs 0.1 ± 0.04, CP vs NP, % of polyhormonal cells of total endocrine cells, P < 0.01), as was expression of CXCL10 in α and β cells.

CONCLUSION

There is increased islet endogenous expression of the inflammation marker CXCL10 in islets in the setting of nondiabetic CP and an increase in polyhormonal (insulin-glucagon expressing) cells. The increase in CPHN cells in CP, often in a lobular distribution, may indicate foci of attempted endocrine cell regeneration.

Elevated Levels of Alpha Cells Emanating from the Pancreatic Ducts of a Patient with a Low BMI and Chronic Pancreatitis

Chronic pancreatitis (CP) is an inflammatory disease that causes progressive damage to the pancreatic parenchyma with irreversible morphological changes and fibrotic replacement of the gland. The risk factors associated with developing CP have been described as toxic (e.g., alcohol and tobacco); idiopathic (e.g., unknown); genetic, autoimmune, recurrent acute pancreatitis, and obstructive (the TIGAR-O system). Upon histological screening of the pancreata from a cohort of CP patients who had undergone pancreatectomy for the treatment of intractable pain in Leicester, UK, one sample showed a striking change in the morphological balance toward an endocrine phenotype, most notably there was evidence of substantial α cell genesis enveloping entire cross sections of ductal epithelium and the presence of α cells within the ductal lumens. This patient had previously undergone a partial pancreatectomy, had severe sclerosing CP, an exceptionally low body mass index (15.2), and diabetes at the time the pancreas was removed, and although these factors have been shown to induce tissue remodeling, such high levels of α cells was an unusual finding within our series of patients. Due to the fact that α cells have been shown to be the first endocrine cell type that emerges during islet neogenesis, future research profiling the factors that caused such marked α cell genesis may prove useful in the field of islet transplantation.

Exocrine Dysfunction Correlates with Endocrinal Impairment of Pancreas in Type 2 Diabetes Mellitus

BACKGROUND

Diabetes mellitus (DM) is a chronic abnormal metabolic condition, which manifests elevated blood sugar level over a prolonged period. The pancreatic endocrine system generally gets affected during diabetes, but often abnormal exocrine functions are also manifested due to its proximity to the endocrine system. Fecal elastase-1 (FE-1) is found to be an ideal biomarker to reflect the exocrine insufficiency of the pancreas.

AIM

The aim of this study was conducted to assess exocrine dysfunction of the pancreas in patients with type-2 DM (T2DM) by measuring FE levels and to associate the level of hyperglycemia with exocrine pancreatic dysfunction.

METHODOLOGY

A prospective, cross-sectional comparative study was conducted on both T2DM patients and healthy nondiabetic volunteers. FE-1 levels were measured using a commercial kit (Human Pancreatic Elastase ELISA BS 86-01 from Bioserv Diagnostics). Data analysis was performed based on the important statistical parameters such as mean, standard deviation, standard error, t-test-independent samples, and Chi-square test/cross tabulation using SPSS for Windows version 20.0.

RESULTS

Statistically nonsignificant (P = 0.5051) relationship between FE-1 deficiency and age was obtained, which implied age as a noncontributing factor toward exocrine pancreatic insufficiency among diabetic patients. Statistically significant correlation (P = 0.003) between glycated hemoglobin and FE-1 levels was also noted. The association between retinopathy (P = 0.001) and peripheral pulses (P = 0.001) with FE-1 levels were found to be statistically significant.

CONCLUSION

This study validates the benefit of FE-1 estimation, as a surrogate marker of exocrine pancreatic insufficiency, which remains unmanifest and subclinical.

Pancreas Atrophy and Islet Amyloid Deposition in Patients With Elderly-Onset Type 2 Diabetes

CONTEXT

With prolonged life expectancy, we often encounter patients with elderly-onset type 2 diabetes mellitus (eT2DM). Although the clinical features of eT2DM are suggested to be different from those in patients with middle-age-onset type 2 diabetes mellitus (mT2DM), the islet pathologic features in eT2DM have not been addressed.

OBJECTIVE

We attempted to characterize the pancreatic pathology in eT2DM and sought its clinical implications.

MATERIALS AND METHODS

Pancreata from 13 young nondiabetic (age, 20 to 29 years), 27 patients with mT2DM (age, 45 to 87 years), 22 middle-age subjects without T2DM, 15 subjects with eT2DM (age, 85 to 100 years), and 30 elderly subjects without T2DM were investigated. Together with conventional microscopic observations, morphometric analysis on the islet, islet endocrine cells, and amyloid deposition was conducted on immunostained sections.

RESULTS

The estimated age of diabetes onset was 80.8 ± 1.4 years (mean ± standard error) in the eT2DM group and that of the mT2DM group was 48.3 ± 2.4 years. The pancreatic weight was nearly 50% less in the eT2DM group than in the other groups, showing duct obstruction with epithelial hyperplasia, marked acinar atrophy, fibrosis, and amyloid deposition in the islet. The islet mass was significantly reduced in the eT2DM group. The amyloid volume density correlated inversely with the β-cell volume density but not with the body mass index in the eT2DM group. Laboratory data showed mild elevation of serum amylase in the eT2DM group, although clinical signs and symptoms of pancreatitis were not apparent.

CONCLUSIONS

eT2DM is distinct from mT2DM and characterized by pancreas atrophy, ductal lesions, and amyloid deposition.

Somatostatin expression in the pancreatic cells of smoking and non-smoking chronic pancreatitis patients with or without diabetes

OBJECTIVES

The aim of the analysis is to determine the location and degree of the hormone immunoreactivity in tissues of patients with chronic pancreatitis and diabetes.

METHODS

The study was performed on 11 non-smoking and 12 smoking patients with chronic pancreatitis (CP) with/without diabetes. The hormone was located in the pancreatic tissues by means of the immunohistochemical method using somatostatin antibodies. The histopathological evaluation of the hormone expression intensity in tissue sections was carried out using the semi-quantitative method and was calculated by means of a digital image analysis.

RESULTS

The hormone's strong immunohistochemical reaction and the modified D-cell location may be a result of the pancreatic tissue fibrosis process prevention in patients with CP. Changes in the intensity of SS immunoreactivity and the D-cell distribution in the pancreas of patients with CP and diabetes may possibly result from the additional hormone compensatory effect in the excessive glucagon secretion inhibition. Smoking patients with diabetes showed significantly higher hormone immunostaining in the pancreas compared to non-smoking patients without diabetes and healthy persons.

CONCLUSIONS

The severity of histopathological changes in smoking CP patients indicates that the cigarette smoke components may further exacerbate the inflammatory reactions. Patients with CP were found to have a strong immunohistochemical reaction to SS and changes in the distribution of D cells when compared to healthy patients. The strongest immunohistochemical SS reaction has been identified in the pancreatic tissue from smoking patients with diabetes.

Chronic Pancreatitis and Diabetes Mellitus

OPINION STATEMENT

Patients with chronic pancreatitis should be screening at least annually for diabetes. Lifestyle modifications remain to be an important part of treatment for diabetic control. Unless contraindicated or not tolerated, metformin can be initiated and continued concurrently with other anti-diabetic agents or insulin. All anti-diabetic agents should be used based on their physiology and adverse effect profiles, along with the metabolic status of patients. Insulin therapy should be initiated without delay for any of the following: symptomatic or overt hyperglycemia, catabolic state secondary to uncontrolled diabetes, history of diabetic ketoacidosis, hospitalization or acute exacerbation of pancreatitis, or hyperglycemia that cannot be otherwise controlled. Dose adjustment should be done conservatively as these patients are more likely to be insulin sensitive and have loss of counter regulatory hormones. Insulin pump and continuous glucose monitoring should be considered early during therapy in selected patients. For patients undergoing total pancreatectomy or extensive partial pancreatectomy, evaluations to determine the eligibilities for islet cell autotransplantation should be considered.

Trefoil factor family peptides in normal and diseased human pancreas

OBJECTIVES

Trefoil factor family (TFF) peptides promote wound healing in the gut. Recent evidence has suggested that TFF3 may be a pancreatic mitogen, an unusual role for TFF peptides. We sought to clarify human pancreatic TFF and mucin expression and performed in vitro experiments to see how pancreatic cell lines respond to TFF3 in particular.

METHODS

Samples of normal and diseased pancreas (chronic pancreatitis, pancreatic intraepithelial neoplasia, neuroendocrine tumors, and pancreatic ductal adenocarcinoma [PDAC]) were studied by immunohistochemistry and in situ hybridization. Pancreatic cell lines were challenged with TFF2 and TFF3 in wound and migration assays.

RESULTS

In normal islets, colocalization of insulin or glucagon with TFF3 was common. All TFF messenger RNAs were seen in ductal epithelium. Adenocarcinomas expressed all TFF messenger RNAs. Normal ducts were mucin free; MUC5AC was strongest in pancreatic intraepithelial neoplasia and chronic pancreatitis but was reduced in PDAC. TFF2 induced Panc-1 migration and accelerated wound closure in Capan-2 and COLO-357. Double immunohistochemistry for insulin or TFF3 and Ki67 colabeled only very rare islet cells. TFF3-positive PDAC ducts showed some Ki67 colocalization.

CONCLUSIONS

No correlation between TFF3 or insulin and Ki67 was seen without ductal hyperplasia. TFF2 may assist pancreatic tumor cell movement, but TFF3 may not be a pancreatic mitogen.

The complex exocrine-endocrine relationship and secondary diabetes in exocrine pancreatic disorders

The pancreas is a dual organ with exocrine and endocrine functions. The interrelationship of the endocrine-exocrine parts of the pancreas is a complex one, but recent clinical and experimental studies have expanded our knowledge. Many disorders primarily of the exocrine pancreas, often solely in the clinical realm of gastroenterologists are associated with diabetes mellitus (DM). Although, the DM becoming disorders are often grouped with type 2 diabetes, the pathogenesis, clinical manifestations and management differ. We review here data on the association of exocrine-endocrine pancreas, the many hormones of the pancreas and their possible effects on the exocrine functions followed by data on the epidemiology, pathogenesis, and management of DM in chronic pancreatitis, cystic fibrosis, pancreatic cancer, and clinical states after pancreatic surgery.

Correlation of histopathology, islet yield, and islet graft function after islet autotransplantation in chronic pancreatitis

OBJECTIVE

The number of islets available (yield) is an important predictor of insulin independence after islet autotransplantation (IAT) done at the time of total pancreatectomy to treat painful chronic pancreatitis. The aim of this study was to correlate histopathologic findings with islet yield and graft function.

METHODS

Pancreatic histopathology was examined in 105 adults who underwent pancreatectomy and IAT; postoperative insulin use was known in 53 cases. Histologic degree of fibrosis, acinar atrophy, inflammation, and nesidioblastosis were scored by a surgical pathologist. The correlation of histopathology with islet yield and graft function was evaluated.

RESULTS

Patients received a median of 2968 islet equivalents per kilogram. Fibrosis and acinar atrophy correlated negatively with islet yield (P < G 0.001, r =0.67), as did inflammation (P < G 0.001, r =0.43). There was a positive correlation of islet yield (P < G 0.0001, r = 0.64) and a negative correlation of fibrosis (P = 0.006, r = 0.43) and acinar atrophy (P = 0.006, r = 0.42) with islet graft function.

CONCLUSION

More severe histopathologic changes were associated with a lower islet yield and lower likelihood of insulin independence. Total pancreatectomy and IAT should not be delayed in patients with painful chronic pancreatitis refractory to medical therapy; otherwise progressive damage to the pancreas may limit islet yield and increase the risk of diabetes.

Implication of pancreatic image findings in total pancreatectomy with islet autotransplantation for chronic pancreatitis

OBJECTIVE

To clarify the implication of pancreatic findings on transabdominal ultrasound and/or abdominal computed tomographic scan on outcomes of islet isolation and endocrine function after total pancreatectomy (TP) with islet autotransplantation (IAT).

METHODS

Retrospective review of islet isolations and graft functions in a cohort of patients with chronic pancreatitis who received TP with IAT from December 2007 to September 2009. Patients were categorized into the following 2 groups on the basis of their transabdominal ultrasound or computed tomographic findings before IAT: early group (normal or equivocal of Cambridge classification) and advanced group (mild to marked).

RESULTS

A total of 12 patients (early group, n=6; advanced group, n=6) were included. Total islet yield per pancreas weight and per patient body weight in the early group was significantly higher compared with that in the advanced group (6989±659 vs 3567±615 islet equivalents per gram, P<0.01; 8556±953 vs 3847±739 islet equivalents per kilogram, P<0.01, respectively). Four patients (67%) in the early group became insulin-free, whereas 2 patients (33%) in the advanced group obtained insulin independence. However, both groups maintained islet graft function and similar glycated hemoglobin levels after transplantation.

CONCLUSIONS

Excellent glycemic control was observed in both groups of patients who received TP with IAT, although the early group showed a significantly better outcome of islet isolation.

Correlation of pancreatic histopathologic findings and islet yield in children with chronic pancreatitis undergoing total pancreatectomy and islet autotransplantation

OBJECTIVES

The probability of insulin independence after intraportal islet autotransplantation (IAT) for chronic pancreatitis (CP) treated by total pancreatectomy (TP) relates to the number of islets isolated from the excised pancreas. Our goal was to correlate the islet yield with the histopathologic findings and the clinical parameters in pediatric (age, <19 years) CP patients undergoing TP-IAT.

METHODS

Eighteen pediatric CP patients aged 5 to 18 years (median, 15.6 years) who underwent TP-IAT were studied. Demographics and clinical history came from medical records. Histopathologic specimens from the pancreas were evaluated for presence and severity of fibrosis, acinar cell atrophy, inflammation, and nesidioblastosis by a surgical pathologist blinded to clinical information.

RESULTS

Fibrosis and acinar atrophy negatively correlated with islet yield (P = 0.02, r = -0.50), particularly in hereditary CP (P = 0.01). Previous duct drainage surgeries also had a strong negative correlation (P = 0.01). Islet yield was better in younger (preteen) children (P = 0.02, r = -0.61) and in those with pancreatitis of shorter duration (P = 0.04, r = -0.39).

CONCLUSIONS

For preserving beta cell mass, it is best to perform TP-IAT early in the course of CP in children, and prior drainage procedures should be avoided to maximize the number of islets available, especially in hereditary disease.

Reduced pancreatic volume and beta-cell area in patients with chronic pancreatitis

BACKGROUND & AIMS

Chronic pancreatitis (CP) often leads to the development of diabetes. To understand better this pathogenic mechanism, we investigated whether islet cell area and pancreatic volume are reduced in CP patients, islet cell turnover increases in CP patients, and islet cells are less vulnerable to apoptosis than acinar cells.

METHODS

Pancreatic tissues from 43 patients with CP and 27 controls were examined by immunohistochemistry and quantitative morphometry. Pancreas volume was determined using abdominal computed tomography data.

RESULTS

The pancreatic volumes were 64.9 +/- 4.3 cm(3) in CP patients and 82.3 +/- 6.7 cm(3) in controls (P = .035). beta-cell areas were 0.69% +/- 0.08% in CP patients and 0.97% +/- 0.08% in controls (P = .017), whereas alpha-cell areas did not differ between the groups (P = .47). There were no differences in the frequencies of replication among groups of alpha-cells, beta-cells, duct cells, or acinar cells nor were there differences in numbers of apoptotic alpha-cells or beta-cells between CP patients and controls. However, CP patients had an approximately 10-fold increase in numbers of apoptotic acinar cells compared with controls (P < .0001).

CONCLUSIONS

Pancreatic volume was reduced by 21%, and the area comprising beta-cells was reduced by 29% in patients with CP. The lack of increased beta-cells turnover in CP patients, despite an approximately 10-fold increase in the number of apoptotic acinar cells, suggests that the damage to the pancreas is highly specific for the exocrine compartment and affects the endocrine islets to a lesser extent.

Pancreatic regenerating protein I in chronic pancreatitis and aging: implications for new therapeutic approaches to diabetes

OBJECTIVES

We investigated the relationship of pancreatic regenerating protein (reg) in models of acinar cell atrophy and aging, and the effect of reg I protein replacement on glucose tolerance.

METHODS

Rats underwent pancreatic duct ligation (PDL) and were followed through 12 months. Aging rats were studied at 12 and 20 months. Intraperitoneal glucose tolerance tests (IPGTTs) were performed, pancreatic reg I, reg I receptor, insulin gene expression, and reg I protein levels were measured. Pancreatic duct ligation and aged animals were treated with exogenous reg I protein and assessed for glucose metabolism.

RESULTS

After PDL, chronic atrophic pancreatitis developed, with a progressive loss of acinar cells and pancreatic reg I. During aging, a similar depression of reg I gene expression was also noted. The reg I levels correlated with pancreatic insulin levels. Twelve months after PDL, IPGTT results were abnormal, which were significantly improved by administration of reg I protein. Aged animals demonstrated depressed IPGTT, which marginally improved after reg I administration. Anti-reg antibody administration to young rats depressed IPGTT to elderly levels.

CONCLUSIONS

Depletion of the acinar product reg I is associated with the pathogenesis of impaired glucose tolerance of pancreatitis-associated diabetes and aging, and replacement therapy could be useful in these patients. Reg I is an acinar cell product, which affects islet function.

Mechanisms and emerging treatments of the metabolic complications of chronic pancreatitis

OBJECTIVES

Exocrine and endocrine abnormalities in chronic pancreatitis contribute to the morbidity and mortality risks of the disease. Complications of exocrine insufficiency include malabsorption, vitamin deficiency syndromes, and weight loss. Oral enzyme replacement therapy is usually effective if attention is paid to factors that affect the bioavailability of enzyme preparations. Complications of endocrine insufficiency can be more difficult to treat due in part to an incomplete knowledge of their etiology.

METHODS

This review focuses on the endocrine aspects of chronic pancreatitis and highlights the observations of our laboratory on the pathogenesis of the metabolic complications of the disease.

RESULTS

In addition to decreased insulin secretory capacity, pancreatogenic (or apancreatic) diabetes is characterized by decreased or absent glucagon and pancreatic polypeptide (PP) secretion, a loss of hepatic insulin receptor (IR) expression/availability, and an impairment in hepatic IR function (phosphorylation and endocytosis). Diminished hepatic IR expression in chronic pancreatitis appears to be because of PP deficiency; laboratory animals and patients with PP deficiency demonstrate decreased hepatic IR availability that is reversed by prolonged (8-hour) PP administration. The impairment in hepatic IR function appears independent of PP deficiency but is reversed by prolonged (28-day) treatment with the insulinotropic/insulinomimetic hormone glucagon-like peptide 1. The endocytosis of hepatic IR is linked to the endocytosis of the glucose transporter 2 from the hepatocyte plasma membrane, and studies suggest that the 2 plasma membrane-bound proteins are complexed noncovalently to function and translocate as a unit after insulin binding to the hepatic IR. The process appears vigorous and sensitive enough to account for a significant reduction in hepatic glucose output and may represent a major mechanism for insulin regulation of hepatic glucose production.

CONCLUSIONS

The regulatory mechanisms of PP-mediated hepatic IR expression and combined IR and GLUT2 endocytosis after insulin binding are defective in chronic pancreatitis and contribute to the apancreatic diabetes, which characterizes this disease.

Chronic pancreatitis, pseudotumors and other tumor-like lesions

Chronic pancreatitis is a fibroinflammatory disease of the pancreas. Etiologically, most cases are related to alcohol abuse and smoking. Recently, gene mutations have been identified as the cause of hereditary pancreatitis. Other chronic pancreatitis types that were defined in recent years are autoimmune pancreatitis (lymphoplasmacytic sclerosing pancreatitis) and paraduodenal pancreatitis ('groove pancreatitis', 'cystic dystrophy of heterotopic pancreas'). This review describes and discusses the main histological findings, the pathogenesis and the clinical features of the various types of chronic pancreatitis. In addition, pseudotumors and other tumor-like lesions are briefly mentioned.

Dysfunction of the pancreas in healthy smoking persons and patients with chronic pancreatitis

OBJECTIVES

The aim of the study was to assess the effect of cigarette smoking on the endocrine pancreatic function by determining the levels of serum glucose and plasma insulin as well as by defining immunohistochemical localization of insulin and glucagon in tissue specimens of the pancreata derived from healthy persons and smoking and nonsmoking patients with diagnosed chronic pancreatitis (CP).

METHODS

The oxidative method was used to measure fasting glycemia in blood plasma and the method enzyme-linked immunoassay to determine the level of insulin in plasma. Immunohistochemical localization of hormones in paraffin tissue specimens of the pancreas was performed using the LSAB2-HRP visual test with polyclonal insulin and glucagon antibodies. The intensity of immunohistochemical reaction was calculated with digital imaging methodology.

RESULTS

The study revealed a substantially higher level of serum glucose in smoking CP patients and in healthy persons compared with nonsmoking patients and healthy persons, whereas insulin concentration in smoking patients was statistically lower than in nonsmokers. Smoking patients showed significantly lower expression of insulin and glucagon in the pancreas compared with nonsmoking patients and healthy persons.

CONCLUSIONS

Impairment of the endocrine function of beta and alpha cells in the pancreatic islets is frequently manifested by complications in pancreatitis resulting among others from long-term smoking.

Clinical features and morphological characterization of 10 patients with noninsulinoma pancreatogenous hypoglycaemia syndrome (NIPHS)

OBJECTIVE

Noninsulinoma pancreatogenous hypoglycaemia syndrome (NIPHS), characterized by postprandial neuroglycopaenia, negative prolonged fasts and negative perioperative localization studies for insulinoma, but positive selective arterial calcium stimulation tests and nesidioblastosis in the gradient-guided resected pancreas, is a rare hypoglycaemic disorder of undetermined aetiology. We analysed the clinical, morphological and immunohistological features to further clarify the aetiology and pathogenesis of this rare disease.

PATIENTS

Ten consecutive patients with NIPHS (nine men and one woman, aged 29-78 years) were included in the study. Six of the 10 received a gradient-guided subtotal (70%) or distal (50%) pancreatectomy. In the remaining four patients, diazoxide treatment was initiated and the precise mechanism of its action was assessed by meal tests.

RESULTS

All of the patients showed a combination of postprandial neuroglycopaenia, negative prolonged fasts (except one patient) and negative localization studies for insulinoma, but positive calcium stimulation tests and nesidioblastosis in the gradient-guided resected pancreas. Immunohistological studies of the resected pancreatic tissues revealed neither an increased rate of proliferation of beta-cells nor an abnormal synthesis and/or processing of either proinsulin or amylin. Evidence of overexpression of the two pancreatic differentiation factors, PDX-1 and Nkx-6.1, as well as the calcium sensing receptor (CaSR) was absent. Nevertheless, abnormal expression of islet neogenesis-associated protein (INGAP), a human cytokine expressed only in the presence of islet neogenesis, in ducts and/or islets, was identified in three of the five patients studied. All of the six patients who received a surgical operation were relieved of further neuroglycopaenic attacks, but one patient who received a subtotal pancreatectomy developed diabetes. In the remaining four patients who received diazoxide treatment, hypoglycaemic episodes were satisfactorily controlled with an attenuated response of beta-cell peptides to meal stimulation.

CONCLUSIONS

Our results strengthen the existence of this unique clinical hypoglycaemic syndrome from beta-cell hyperfunction as well as the value of the selective arterial calcium stimulation test in its correct diagnosis and localization. The mechanisms underlying beta-cell hyperfunction and release of insulin to calcium, however, remain poorly characterized. Nevertheless, in a subset of patients with NIPHS, there exists some, as yet undefined, pancreatic humoral/paracrine factor(s) other than proinsulin, amylin, PDX-1, Nkx-6.1 and possibly glucagon-like peptide-1 (GLP-1) that are capable of inducing the INGAP gene and, if activated, will initiate ductal proliferation and islet neogenesis. As for the treatment, we recommend that diazoxide be tried first in each patient and, should it fail, a gradient-guided subtotal or distal pancreatectomy be attempted.

Chronic pancreatitis of alcoholic and nonalcoholic origin

Fibroinflammatory changes to the pancreatic tissue characterize chronic pancreatitis. This article summarizes the current state of knowledge on the pathology and pathogenesis of chronic pancreatitis associated with alcohol, hereditary factors, metabolic conditions, and anatomical abnormalities. Specifically, the pathogenetic mechanisms that lead to chronic pancreatitis in patients with alcohol abuse will be discussed. In addition, brief descriptions of the features of chronic pancreatitis of nonalcoholic origin and of the pancreatic fibrosis that is not associated with symptoms of chronic pancreatitis will be given.

Diagnostik und Therapie der chronischen Pankreatitis

Chronic pancreatitis is characterized by recurrent or persisting pain. As the exocrine pancreatic insufficiency occurs early in the progression of the disease, the endocrine function may persist intact. Imaging procedures and pancreatic function tests are used to make a diagnosis. Therapy consists of pain reduction, which might require endoscopic or surgical intervention. Treatment of exocrine and endocrine pancreatic insufficiency is based on diet and substitution of pancreatic enzymes, minerals and vitamins, as well as insulin.

Alcoholic pancreatitis

A history of excessive alcohol consumption is found in the majority of patients with chronic pancreatitis, and numerous research efforts revealed insights into the pathogenesis of alcohol-induced pancreatic damage. However, the exact mechanisms underlying the disease are not yet clarified, and the origin of alcoholic chronic pancreatitis continues to be the topic of speculation and investigation. This article provides an overview about the epidemiology of alcoholic chronic pancreatitis, the epidemiologic association of alcohol intake and pancreatitis and the clinical course of the disease. Finally, this article summarizes several hypothetical concepts that try to explain the early and late pathophysiological mechanisms of acute and chronic pancreatitis.

Nutritional effects of oesophageal, gastric and pancreatic carcinoma

Cancer of the oesophagus, stomach or pancreas has profound effects on the nutritional status of the individual as normal functioning of these digestive organs is essential to physiological well-being. Thus the cancer patient is subjected not only to the localized and systemic effects of carcinoma but to the body's inability to properly nourish itself. It is therefore surprising that there is such a dearth of knowledge with respect to the effects of cancer of these organs on the totality of nutritional status as the technology is now available to address this important issue. Furthermore, as the value of nutritional support for such patients is gaining widespread acknowledgement the use of such technology should be employed, not only to accurately and precisely define the changes in nutritional status, body composition, physiological function and psychological state, but to monitor the effect of established treatment and assess the efficacy of novel new treatments. The purpose of this review is to describe the technology which is available to achieve this, outline some of the published work on nutrition and cancer of the oesophagus, stomach and pancreas and, finally, to discuss possible future trends in this area of clinical practice.

Cystic fibrosis-related diabetes

Diabetes mellitus (DM) has been recognized as a complication of cystic fibrosis (CF) for almost 50 years and commonly develops around 20 years of age. The prevalence increases with age and, with improved survival of those with CF, approaches 30% in certain centres. Its development appears to have a significant impact on pulmonary function and may increase mortality by up to six-fold. Subjects with CF are rarely ketosis-prone and phenotypically lie between Type 1 and Type 2 DM. Microvascular complications are recognized, although paucity of data does not permit a clear description of their natural history. An annual oral glucose tolerance test from the age of 10 years is recommended for screening, but logistical difficulties have led some groups to develop specific algorithms to aid diagnosis. Insulin sensitivity in CF is much debated and may depend upon the degree of glucose intolerance. Insulin resistance occurs in the presence of infection, corticosteroid usage and hyperglycaemia, whilst hepatic insulin resistance is considered an adaptation to CF. There is no universal consensus on the treatment of hyperglycaemia. With increased longevity of individuals with CF, greater numbers will develop diabetes and the diabetes physician is destined to play a greater role in the multidisciplinary CF team.

Ductulo-insular pancreatic endocrine neoplasms: clinicopathologic analysis of a unique subtype of pancreatic endocrine neoplasms

Pancreatic neoplasms with mixed ductal and endocrine components are a heterogeneous group of tumors. The least recognized of these are pancreatic endocrine tumors (PETs) displaying benign-appearing tumor-associated ductules. To characterize these ductulo-insular pancreatic endocrine tumors (DI-PETs), we reviewed a series of 92 resected PETs. To be considered as a DI-PET we required the presence and tight intermingling of ductules with the dominant endocrine component (including the presence of ductulo-insular units). A total of 15 PETs fulfilled our criteria (16.3%). The average age of the DI-PET patients was similar to typical PETs (54 years vs 56 years). These tumors were smaller and more often insulin positive than typical PETs (p <0.05). Diffuse stromal fibrosis was more frequent in DI-PETs (11 of 15; 73.3.7%) compared with PETs (8 of 72; 11.1%) (p <0.05). The tumor-associated ductules were composed of cuboidal cells with dense eosinophilic cytoplasm and round nuclei without atypia or mitoses. They were positive for cytokeratin 7 and cytokeratin 19 and lacked any neuroendocrine markers. Reversibly, the endocrine component was negative for cytokeratin 7 and cytokeratin 19 and positive for neuroendocrine markers. Ultrastructural examination of ductulo-insular units confirmed a dual ductal and endocrine differentiation with amphicrine differentiation in one case. Follow-up was available in 12 cases with an average follow-up of 70.1 months (range 25-203 months). Ten patients are currently alive, and two patients died 81 and 158 months after surgery. We conclude that DI-PETs are not uncommon and that they are biologically similar to other PETs. We also hypothesize that the ductal cells develop by transdifferentiation of the endocrine cells.

Mixed ductal-endocrine carcinomas of the pancreas and ductal adenocarcinomas with scattered endocrine cells: characterization of the endocrine cells

We compared the histological and immunohistochemical features of mixed ductal-endocrine carcinomas of the pancreas with those of ductal adenocarcinomas (DACs) containing scattered tumor-associated endocrine cells (SECs). Three pancreatic neoplasms fulfilled the WHO criteria for mixed ductal-endocrine carcinomas. Two of them showed moderately to poorly differentiated glandular structures composed of both mucin producing and neuroendocrine cells. The third mixed ductal-endocrine carcinoma was of the composite type showing DAC structures and a solid component with small epithelial cells, most of them of neuroendocrine nature. In 32 of 34 cases of DAC located in the head (30 cases) and body to tail (4 cases) of the pancreas and showing lymph-node metastases, SECs were found, but they were few in number and irregularly distributed in the tumors. In three DACs a few SECs were also detected in lymph-node metastases. Double staining for chromogranin A and the proliferation marker Ki-S5 revealed that all SECs that were not intimately integrated into the neoplastic glandular epithelium failed to show proliferative activity and changes of the expression of tumor suppressor genes (p53 and DPC 4). These findings suggest that only those SECs that belong to the proliferative cell fraction may be of neoplastic origin, while the majority of SECs probably constitute a tumor-associated but non-neoplastic cell population. These features contrast with those of mixed ductal-endocrine carcinomas, in which all endocrine cells are a component of the neoplasm.

Pancreatic hepatocytes in hamsters (Mesocricetus auratus) infected with Trypanosoma cruzi

Hepatocytic metaplasia may be induced in hamsters by carcinogens, and associated with aging, diabetes or chronic pancreatitis. By means of histopathologic and immunohistochemic studies, we observed pancreatic hepatocytes in hamsters infected and reinfected with Trypanosoma cruzi. The change was seen in 18 (19%) out of 94 infected animals, and was not found among 53 controls, Normal islet cells were immunoreactive for neuron-specific enolase and not reactive for NCL-HAS. Metaplastic cells were immunoreactive for NCL-HAS and not reactive for islet hormones and enolase. No relationship was observed between number of inoculations and metaplasia; however, the intensity of the inflammatory process and sequels seems to favor the development of metaplastic cells. Hamsters infected with T. cruzi may be useful to study hepatocytic metaplasia, and contribute to clarify aspects of Chagas' disease and pancreatic changes. Our data indicate that aging, in addition to inflammation and atrophy, plays a role in this change.

Histopathology and immunohistochemistry of pancreatic islets in fibrocalculous pancreatic diabetes

The histopathology of Fibrocalculous Pancreatic Diabetes (FCPD) has been extensively studied, but there are no reports on alteration in patterns of hormone secreting cells using immunohistochemistry in islets of FCPD patients. In this study, we report on the histopathology and immunohistochemistry of islets of FCPD patients and its possible correlation with the clinical picture. Pancreatic biopsies were carried out in six patients with FCPD at the time of surgery for abdominal pain. Routine histopathology and immunohistochemistry studies were carried out with six primary antibodies namely insulin, glucagon, pancreatic polypeptide (PP), somatostatin, vasoactive intestinal peptide and gastrin. Histopathology of the pancreas showed a spectrum of changes ranging from moderate to severe atrophy, fibrosis of the parenchyma and degeneration of the ducts. Nesidioblastosis was present in three patients. Immunohistochemical studies showed a decrease in the number of islets but some patients showed evidence of hyperplasia. There was an overall decrease in the percent of insulin cells and the positivity in the islets correlated with plasma C-peptide levels and the duration of diabetes. There was no consistent relationship with glucagon with some patients showing increased and other decreased positivity. There was a marked decrease in PP and somatostatin positivity, the significance of which is not clear. The reduction, but partial preservation of insulin positivity is consistent with the ketosis resistance shown by patients with Fibrocalculous Pancreatic Diabetes.

Pancreatic exocrine-endocrine interrelationship. Clinical implications

The exocrine and endocrine pancreata are anatomically and functionally interrelated. As a result, exocrine pancreatic dysfunction often accompanies endocrine pancreatic dysfunction and vice versa. This article delineates the nature of these exocrine and endocrine pancreatic interrelationships and their clinical significance in the management of pancreatic disorders.

Progression from acute to chronic pancreatitis. A pathologist's view

The available morphologic data on ACP are consistent with the view that ACP evolves from acute pancreatitis. How alcohol abuse triggers pancreatic injury and which factors are responsible for the progression to chronic pancreatitis remain to be clarified, however.

Morphological study of pancreatic endocrine in an experimental chronic pancreatitis with diabetes induced by stress and cerulein

The purpose of this study was to investigate the morphological changes in the islets observed in a new chronic pancreatitis model with diabetes induced by repetition of cerulein injection plus water-immersion stress in rats. The rats of this model were treated with water-immersion stress for 5 h and two intraperitoneal injections of 20 micrograms/kg body weight of cerulein once a week for 16 weeks. In the stress and cerulein group, 62% of the islets exhibited infiltration of mononucleated cells, and/or peri- and intrainsular fibrosis. On immunohistochemical study, some islets showed reduced density of the insulin immunoreactivity. The glucagon-producing cells decreased in number. With electron microscopy, various endocrine changes were observed, mainly in the B cells. The changes included scattered debris damage with reduction of secretary granules, and vesiculation of the endoplasmic reticulum. Numerous fibroblasts clustered around the islets, and proliferating collagen fibers invaded the islets. The microvascular changes consisted of bleeding and damage to the endothels. In the pancreas treated with stress alone or cerulein alone, significant endocrine damage was not observed. In conclusion, chronic repetitive treatment with stress and cerulein, together with poor islet circulation due to fibrosis and vascular changes, resulted in the endocrine cellular damage.

Transdifferentiation versus stem cell hypothesis for the regeneration of islet beta-cells in the pancreas

The pancreas is composed of at least three types of differentiated tissue: the hormone-containing cells in islets (4 different cell types), the exocrine zymogen-containing acini, and the centroacinar cells, ductules and ducts (ductal tree). All of these cells appear to have a common origin during embryogenesis in the form of duct-like protodifferentiated cells. Later in life, the acinar and ductal cells retain a significant proliferative capacity that can ensure cell renewal and growth, whereas the islet cells become mitotically inactive. Interestingly, new islet cells, including the insulin-producing beta-cells, can regenerate after tissue injury by a process called neogenesis. The neogenetic process involves differentiation of duct-like (exocrine) epithelial cells to hormone-expressing cells. In this paper, we review the question whether islet beta-cell regeneration or neogenesis in the pancreas depends on "embryonic-like" stem cells or on transdifferentiation of "fully differentiated" cells. This issue is important to find the right model for in vitro research aiming at controlling the process of beta-cell neogenesis. The latter could lead to applications in the treatment of diabetes where functional beta-cells are deficient. We conclude from the available evidence that there is as yet no evidence for the existence of "dormant" stem cells in the adult pancreas. There is some evidence, however, that differentiated exocrine acinar and/or duct cells retain the capacity to transdifferentiate into insulin-expressing beta-cells.

Histometric analysis of the distal pancreas in pancreatic head cancer

To clarify the histological status of the pancreas tail after pancreatoduodenectomy (PD), fibrosis, islets of Langerhans, and A, B, and D cells were examined histometrically in surgical cases of pancreatic cancer. The same investigations were also performed during an autopsy examination of the pancreas tail of survivors of surgery who had received either PD or total pancreatectomy with segmental autotransplantation (SAT). In the surgical cases, fibrosis and the islet percentage compared with nonpancreatic cancer cases were significantly higher while the B cell ratio was significantly lower. In addition, in pancreatic cancer patients, the fibrosis and islet ratio in the group with a blocked pancreatic duct were higher while the B cell ratio was lower than in the group with an open pancreatic duct. A direct relationship between the islet ratio and the degree of fibrosis, and an inverse relationship between the B cell ratio and the degree of fibrosis, were thus found. From the autopsy cases, the fibrosis progressed and the islet ratio increased following PD, but after SAT only the islet ratio increased compared to the time of surgery. The progression of fibrosis after PD thus suggests the presence of some problems in both the surgical method and postoperative management.

Correlation between pancreatic endocrine and exocrine function and characteristics of pancreatic endocrine function in patients with diabetes mellitus owing to chronic pancreatitis

CONCLUSION

Pancreatic endocrine capacities are remarkably disturbed in patients with pancreatic diabetes owing to calcific pancreatitis as opposed to those owing to noncalcific pancreatitis. Insulin secretion in calcific pancreatitis resembled that in insulin-dependent diabetes mellitus (IDDM), whereas insulin secretion in noncalcific pancreatitis resembled that in non-IDDM (NIDDM). The involvements of acinar cell and ductal cell function closely correlate with endocrine function (insulin and glucagon secretions) in chronic pancreatitis (pancreatic diabetes).

BACKGROUND

We sought to clarify the differences of pancreatic endocrine function between pancreatic diabetes and primary diabetes, and to verify the correlations between pancreatic exocrine and endocrine dysfunction in patients with chronic pancreatitis.

METHODS

Urinary C-peptide (CPR) excretion and fasting plasma glucagon levels in patients with pancreatic diabetes owing to calcific pancreatitis (19 cases) and owing to noncalcific pancreatitis (14 cases) were studied in comparison with those in patients with insulin-dependent diabetes mellitus (IDDM, 23 cases), noninsulin-dependent diabetes (NIDDM, 18 cases), and in healthy controls (11 cases). In addition, pancreatic exocrine function was investigated in patients with chronic pancreatitis (calcific and noncalcific) and in healthy controls. The correlation between pancreatic exocrine and endocrine function was studied.

RESULTS

The urinary CPR excretion in controls was 94.9 +/- 20.5 micrograms/d. The urinary CPR excretion in calcific pancreatitis was 12.8 +/- 7.4 micrograms/d and it resembled that in IDDM (9.4 +/- 5.8 micrograms/d). The urinary CPR excretion in noncalcific pancreatitis was 41.5 +/- 30.1 micrograms/d, being similar to that in NIDDM (49.3 +/- 21.0 micrograms/d). The plasma glucagon level in calcific pancreatitis was 64.1 +/- 15.9 rho g/mL, which was significantly lower than the values in IDDM (111.2 +/- 50.2 rho g/mL) and NIDDM (96.7 +/- 21.9 rho g/mL). The plasma glucagon level in calcific and noncalcific pancreratitis (88.4 +/- 29.6 rho g/mL) were significantly lower than that in controls (129.8 +/- 21.6 rho g/mL). The residual capacities of acinar cells and ductal cells were strongly correlated with urinary CPR excretion and plasma glucagon concentration.

Pancreatic regeneration (reg) gene expression in a rat model of islet hyperplasia

BACKGROUND

After pancreatectomy, regeneration of acinar and islet elements occurs. Recent data from a model of islet hyperplasia in the hamster suggested that induction of a local pancreatic factor stimulates islet formation. We postulate that the reg gene may be this factor.

METHODS

We studied reg expression during induction of islet growth by using a similar model in the rat. Rats underwent surgical wrapping of the splenic lobe of the pancreas or sham operation.

RESULTS

At 2 days ductular proliferation and immunohistochemical evidence of insulin within ductular epithelia were evident in the wrapped lobe. By 14 and 56 days islet number per square millimeter increased 63% and 43%, respectively. Reg mRNA levels, measured by Northern blot analysis with a rat reg cDNA probe (n = 5), increased 300% at 2 days in the wrapped lobe and decreased to that of unwrapped controls by 14 days. In situ hybridization showed localization of reg to the acinar cells. In unwrapped gastric lobes of animals who underwent surgical wrapping of the splenic lobe, no change in islet number per square millimeter or reg gene expression was noted.

CONCLUSIONS

Surgical wrapping of the pancreatic splenic lobe induces local reg gene expression that is temporally associated with duct cell hyperplasia. This is followed by islet formation within the wrapped lobe. Reg may play a role in the induction of new islets from ductular precursors and in maintenance of normal islet function.

Expression of endothelin-1 in pancreatic tissue of patients with chronic pancreatitis

Chronic pancreatitis is characterized by the presence of an inflammatory infiltrate, progressive destruction of acinar cells, and fibrosis. The finding that endothelin-1, an endothelium-derived peptide with vasoconstrictive and mitogenic properties, reduces pancreatic blood flow in normal rats suggested that the peptide may be associated with the reduced pancreatic flow seen in animal models of chronic pancreatitis and in the morphological abnormalities of the disease. The aim of this study was to investigate sites of endothelin-1 expression in the pancreas of normal subjects and patients with chronic pancreatitis. The techniques of immunohistochemistry, in situ hybridization, and Northern blotting were used. Endothelin-1-like immunoreactivity was localized predominantly to islet cells both in normal subjects and in patients with chronic pancreatitis. Semi-quantitative analyses of immunostaining showed that endothelin-1-like immunoreactivity in islet cells of patients with chronic pancreatitis was greater than in normal subjects. Co-localization studies with glucagon, insulin, somatostatin, and pancreatic polypeptide showed that endothelin-1-like immunoreactivity co-exists with glucagon and insulin. There was no apparent co-existence of endothelin-1-like immunoreactivity with somatostatin or pancreatic polypeptide. Endothelin-1 mRNA was expressed in sites similar to those of the immunostaining, as well as in vascular endothelial cells. Northern blot analysis showed an increase in the expression of endothelin-1 mRNA in the patient population. There was a significant correlation between intensity of endothelin-1 immunostaining and severity of fibrosis in the patients with chronic pancreatitis. These findings suggest that an elevation in local expression of endothelin-1 may be associated with the morphological and haemodynamic changes of chronic pancreatitis.

Atrio-ventricular nodal tumor associated with polyendocrine anomalies

We report the clinical and autopsy findings of a young female suffering of complete heart block since the age of 11 and who suddenly died at the age of 32 because of a polycystic atrio-ventricular node tumor. In association with this tumor, we observed a hyperplasia of the islets of Langherans, a true thymic hyperplasia, bilateral multicystic ovaries, adrenal tissue heterotopia and clear cell adenomatosis in the right kidney. We suggest that the polycystic atrio-ventricular node tumor may be part of a complex syndrome with endocrine disorders and heterotopias.

New chronic pancreatitis model with diabetes induced by cerulein plus stress in rats

To establish a new experimental model of chronic pancreatitis (CP) with diabetes, we investigated pancreatic endocrine function, blood flow, and histopathology in CP induced by repetition of cerulein injection plus water immersion stress in rats. CP rats were treated with water immersion stress for 5 hr and two intraperitoneal injections of 20 micrograms/kg body weight of cerulein once a week for 16 weeks. In the CP group, pancreatic contents of protein, amylase, elastase, and lipase significantly decreased to 64, 38, 23, and 68% of the control group, respectively. In oral glucose tolerance test (glucose 2 g/kg body wt), blood glucose level in the CP group was 212.1 +/- 97.8 mg/dl (mean +/- SD) at 30 min and was significantly higher than the control group (126.3 +/- 15.4 mg/dl)(P < 0.05). Two of seven rats in the CP group showed an obvious diabetic insulin in the CP group was 640.1 +/- 148.7 pM, significantly lower than in the control group (1133.4 +/- 242.0 pM)(P < 0.001). However, insulin content in the pancreas was 12.37 nmol/pancreas). In CP rats, winding and dilatation of surface blood vessels and gland atrophy were evident. Marked fibrosis, fatty changes, and destruction of lobular architecture were also demonstrated microscopically, although the structure of each pancreatic islet was preserved and each islet was fully stained with anti-insulin antibody. In the CP group, pancreatic blood flow by the hydrogen gas-clearance method was 197.6 +/- 33.0 ml/min/100 g, which was significantly less than the control group (276.2 +/- 19.1 ml/min/100 g) (P < 0.001). Thus, we conclude that the CP model induced by cerulein plus stress is a new CP model with diabetes in rats, in which the glucose tolerance was impaired without loss of insulin reserve.