65 YEARS OF THE DOUBLE HELIX: Genetics informs precision practice in the diagnosis and management of pheochromocytoma.

Although the authors of the present review have contributed to genetic discoveries in the field of pheochromocytoma research, we can legitimately ask whether these advances have led to improvements in the diagnosis and management of patients with pheochromocytoma. The answer to this question is an emphatic Yes! In the field of molecular genetics, the well-established axiom that familial (genetic) pheochromocytoma represents 10% of all cases has been overturned, with >35% of cases now attributable to germline disease-causing mutations. Furthermore, genetic pheochromocytoma can now be grouped into five different clinical presentation types in the context of the ten known susceptibility genes for pheochromocytoma-associated syndromes. We now have the tools to diagnose patients with genetic pheochromocytoma, identify germline mutation carriers and to offer gene-informed medical management including enhanced surveillance and prevention. Clinically, we now treat an entire family of tumors of the paraganglia, with the exact phenotype varying by specific gene. In terms of detection and classification, simultaneous advances in biochemical detection and imaging localization have taken place, and the histopathology of the paraganglioma tumor family has been revised by immunohistochemical-genetic classification by gene-specific antibody immunohistochemistry. Treatment options have also been substantially enriched by the application of minimally invasive and adrenal-sparing surgery. Finally and most importantly, it is now widely recognized that patients with genetic pheochromocytoma/paraganglioma syndromes should be treated in specialized centers dedicated to the diagnosis, treatment and surveillance of this rare neoplasm.

Multiple endocrine neoplasia type 1 associated with a new germline Men1 mutation in a family with atypical tumor phenotype.

BACKGROUND: Multiple endocrine neoplasia type 1 (MEN1) is an autosomal-dominant hereditary disorder associated with the development of endocrine tumors due to reduced expression of the tumor suppressor protein menin. Recent studies indicate a general role of menin in carcinogenesis, affecting the prevalence and clinical course of common non-endocrine tumors such as breast cancer, hepatocellular carcinoma and melanoma. Here we report a new germline missense mutation of Men1 in a German family with atypical tumor phenotype over three generations. Based on the type of mutation, we discuss possible changes in menin function leading to atypical tumorigenesis and present the clinical significance of such findings. CASE PRESENTATION: A German family with a history of primary hyperparathyroidism presented to our Hospital for further evaluation. Members of the family demonstrated many different atypical tumors, such as renal cell carcinoma, papillary thyroid cancer and prostate cancer. DNA sequencing from peripheral blood revealed a novel mutation: Ser38Cys [TCC>TGC] in exon 2, codon 38 of Men1. This novel mutation is located in a region of menin which is responsible for interactions with the transcription factor JunD. This factor has recently been associated with prostate cancer. DNA sequencing of two of the atypical tumors (prostate cancer, papillary thyroid cancer) did not reveal a loss of heterozygosity, indicating an impact on menin expression and function in the heterozygous state, in line with results in +/-Men1 mutant mice developing prostate cancer. CONCLUSION: The results and clinical course of disease in this case indicate the potential role of menin in the development of non-endocrine or atypical-endocrine tumors in MEN1 patients. Further investigations are needed to clarify both the general role of menin and the importance of specific mutations in carcinogenesis. Nevertheless, in families with uncommon manifestations of the syndrome early diagnostic adjustments should be considered.

Everolimus Improves Microcirculatory Derangements in Experimental Postischemic Pancreatitis Modulating the Expression of Vascular Endothelial Growth Factor, Interleukin 6, and Toll-Like Receptor 4.

OBJECTIVES: Ischemia/reperfusion injury (IRI) of the pancreas is a serious complication following pancreatic transplantation and hemorrhagic shock. The present study was designed to investigate the influence of the potent mammalian target of rapamycin inhibitor everolimus interfering via microvascular permeability changing key proteins hypoxia-inducible factor (HIF) and vascular endothelial growth factor on pancreatic IRI-induced microvascular disturbances. METHODS: Anesthetized male Sprague-Dawley rats were assigned to 3 groups (n = 7/group): (1) sham, (2) 60-minute ischemia/reperfusion of the pancreas (I/R), and (3) I/R and everolimus (10 mg/kg BW orally). Quantification of the effective microvascular permeability (P), functional capillary density (FCD), and leukocyte-endothelial cell interaction (LEI) was performed using digital and analog intravital epifluorescence microscopy. Serum-amylase, lipase, interleukin 6, and vascular endothelial growth factor concentration were quantified using enzyme-linked immunosorbent assay. RESULTS: Sham compared with I/R (P: [×10 cm/s] 0.068 ± 0.079 vs 1.516 ± 0.314; FCD: [cm/cm] 357 ± 14 vs 258 ± 13; LEI: [cells/mm] 148 ± 25 vs 349 ± 75) demonstrates a significant increase in microcirculatory damage and all previously mentioned serum parameters. Except amylase, I/R + everolimus led to a statistically significant improvement of almost all increased parameters (P: 0.434 ± 0.296, FCD: 347 ± 16, LEI: 178 ± 30). CONCLUSIONS: Everolimus attenuated experimental microvascular and inflammatory IRI of the pancreas. Therefore, these results may warrant further investigation of everolimus as a therapeutic agent following clinical states with pancreatic ischemia/reperfusion.

A registry-based study of thyroid paraganglioma: histological and genetic characteristics.

The precise diagnosis of thyroid neoplasias will guide surgical management. Primary thyroid paraganglioma has been rarely reported. Data on prevalence, immunohistochemistry (IHC), and molecular genetics in a systematic series of such patients are pending. We performed a multinational population-based study on thyroid paraganglioma and analyzed prevalence, IHC, and molecular genetics. Patients with thyroid paraganglioma were recruited from the European-American-Head-and-Neck-Paraganglioma-Registry. Demographic and clinical data were registered. Histopathology and IHC were re-investigated. All patients with thyroid paraganglioma underwent molecular genetic analyses of the SDHA, SDHB, SDHC, SDHD, SDHAF2, VHL, RET, TMEM127, and MAX genes. Analyses included Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) for detection of large rearrangements. Of 947 registrants, eight candidates were initially identified. After immunohistochemical analyses of these eight subjects, 5 (0.5%) were confirmed to have thyroid paraganglioma. IHC was positive for chromogranin, synaptophysin, and S-100 and negative for calcitonin in all five thyroid paragangliomas, whereas the three excluded candidate tumors stained positive for pan-cytokeratin, a marker excluding endocrine tumors. Germline variants, probably representing mutations, were found in four of the five confirmed thyroid paraganglioma cases, two each in SDHA and SDHB, whereas the excluded cases had no mutations in the tested genes. Thyroid paraganglioma is a finite entity, which must be differentiated from medullary thyroid carcinoma, because medical, surgical, and genetic management for each is different. Notably, approximately 80% of thyroid paragangliomas are associated with germline variants, with implications for additional tumors and a potential risk for the family. As opposed to sporadic tumors, surgical management and extent of resection are different for heritable tumors, each guided by the precise gene involved.

Cytokine and radical inhibition in septic intestinal barrier failure.

BACKGROUND: Breakdown of the intestinal barrier is a driving force of sepsis and multiple organ failure. Radical scavengers or cytokine inhibitors may have a therapeutic impact on intestinal failure. Therapeutic effects on different sites of small intestine and colon have not been compared. Therefore, we investigated time-dependent intestinal permeability changes and their therapeutic inhibition in colon and small intestine with an ex vivo model. METHODS: Male Sprague-Dawley rats were either pretreated for 24 h with lipopolysaccharide (LPS) intraperitoneally alone or in combination with a radical scavenger (pyruvate or Tempol) or a cytokine inhibitor (parecoxib or vasoactive intestinal peptide). The gastrointestinal permeability was measured by time-dependent fluorescein isothiocyanate inulin diffusion using washed and everted tube-like gut segments. Blood and tissue samples were taken to investigate the development of inflammatory cytokine level (interleukin 6) in the context of cytokine inhibition and reactive oxygen species level via nicotinamide adenine dinucleotide phosphate oxidase activity in radical scavenger groups. RESULTS: After LPS treatment, mucosal permeability was enhanced up to 170% in small intestine and colon. In the small intestine the most significant reduction in permeability was found for pyruvate and parecoxib. Treatment with vasoactive intestinal peptide and parecoxib resulted in the most pronounced reduction of permeability in the colon. CONCLUSIONS: Our data suggest that cytokine inhibitors and radical scavengers have pronounced effects in LPS-induced disrupted intestinal barrier of the colon and small intestine. Our novel model comparing different anatomic sites and different points in time after the onset of sepsis may contribute to gain new insight into mechanisms and treatment options of sepsis-related gut mucosal breakdown.

Outcomes of adrenal-sparing surgery or total adrenalectomy in phaeochromocytoma associated with multiple endocrine neoplasia type 2: an international retrospective population-based study.

BACKGROUND: The prevention of medullary thyroid cancer in patients with multiple endocrine neoplasia type 2 syndrome has demonstrated the ability of molecular diagnosis and prophylactic surgery to improve patient outcomes. However, the other major neoplasia associated with multiple endocrine neoplasia type 2, phaeochromocytoma, is not as well characterised in terms of occurrence and treatment outcomes. In this study, we aimed to systematically characterise the outcomes of management of phaeochromocytoma associated with multiple endocrine neoplasia type 2. METHODS: This multinational observational retrospective population-based study compiled data on patients with multiple endocrine neoplasia type 2 from 30 academic medical centres across Europe, the Americas, and Asia. Patients were included if they were carriers of germline pathogenic mutations of the RET gene, or were first-degree relatives with histologically proven medullary thyroid cancer and phaeochromocytoma. We gathered clinical information about patients'RET genotype, type of treatment for phaeochromocytoma (ie, unilateral or bilateral operations as adrenalectomy or adrenal-sparing surgery, and as open or endoscopic operations), and postoperative outcomes (adrenal function, malignancy, and death). The type of surgery was decided by each investigator and the timing of surgery was patient driven. The primary aim of our analysis was to compare disease-free survival after either adrenal-sparing surgery or adrenalectomy. FINDINGS: 1210 patients with multiple endocrine neoplasia type 2 were included in our database, 563 of whom had phaeochromocytoma. Treatment was adrenalectomy in 438 (79%) of 552 operated patients, and adrenal-sparing surgery in 114 (21%). Phaeochromocytoma recurrence occurred in four (3%) of 153 of the operated glands after adrenal-sparing surgery after 6-13 years, compared with 11 (2%) of 717 glands operated by adrenalectomy (p=0.57). Postoperative adrenal insufficiency or steroid dependency developed in 292 (86%) of 339 patients with bilateral phaeochromocytoma who underwent surgery. However, 47 (57%) of 82 patients with bilateral phaeochromocytoma who underwent adrenal-sparing surgery did not become steroid dependent. INTERPRETATION: The treatment of multiple endocrine neoplasia type 2-related phaeochromocytoma continues to rely on adrenalectomies with their associated Addisonian-like complications and consequent lifelong dependency on steroids. Adrenal-sparing surgery, a highly successful treatment option in experienced centres, should be the surgical approach of choice to reduce these complications.

Long-term prognosis of patients with pediatric pheochromocytoma.

A third of patients with paraganglial tumors, pheochromocytoma, and paraganglioma, carry germline mutations in one of the susceptibility genes, RET, VHL, NF1, SDHAF2, SDHA, SDHB, SDHC, SDHD, TMEM127, and MAX. Despite increasing importance, data for long-term prognosis are scarce in pediatric presentations. The European-American-Pheochromocytoma-Paraganglioma-Registry, with a total of 2001 patients with confirmed paraganglial tumors, was the platform for this study. Molecular genetic and phenotypic classification and assessment of gene-specific long-term outcome with second and/or malignant paraganglial tumors and life expectancy were performed in patients diagnosed at <18 years. Of 177 eligible registrants, 80% had mutations, 49% VHL, 15% SDHB, 10% SDHD, 4% NF1, and one patient each in RET, SDHA, and SDHC. A second primary paraganglial tumor developed in 38% with increasing frequency over time, reaching 50% at 30 years after initial diagnosis. Their prevalence was associated with hereditary disease (P=0.001), particularly in VHL and SDHD mutation carriers (VHL vs others, P=0.001 and SDHD vs others, P=0.042). A total of 16 (9%) patients with hereditary disease had malignant tumors, ten at initial diagnosis and another six during follow-up. The highest prevalence was associated with SDHB (SDHB vs others, P<0.001). Eight patients died (5%), all of whom had germline mutations. Mean life expectancy was 62 years with hereditary disease. Hereditary disease and the underlying germline mutation define the long-term prognosis of pediatric patients in terms of prevalence and time of second primaries, malignant transformation, and survival. Based on these data, gene-adjusted, specific surveillance guidelines can help effective preventive medicine.

Blood modulates the kinetics of reactive oxygen release in pancreatic ischemia-reperfusion injury.

OBJECTIVES: Reason for the unsuccessful use of antioxidants in transplantation might be the unknown kinetics of reactive oxygen species (ROS) release. In this study, we compared the kinetics of ROS release from rat pancreata in the presence and absence of blood. METHODS: In vivo, ischemia-reperfusion injury (IRI) was induced in pancreata of male Wistar rats by occlusion of the arterial blood supply for 1 or 2 hours. In vitro, isolated pancreata were single-pass perfused with Krebs-Henseleit bicarbonate solution. Reactive oxygen species were quantified by electron spin resonance spectroscopy using CMH (1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine) as spin label. Thiols (glutathione), nicotinamide adenine dinucleotide phosphate-oxidase activity, myeloperoxidase activity, and adenosine triphosphate content were measured. RESULTS: During reperfusion, an increase in IRI-induced ROS in arterial blood was noted after 2 hours of warm ischemia. In sharp contrast, ROS release was immediate and short lived in blood-free perfused organs. The degree of tissue damage correlated with nicotinamide adenine dinucleotide phosphate-oxidase activity and adenosine triphosphate content. Antioxidative capacity of tissues was reduced. CONCLUSIONS: Electron spin resonance spectroscopy in conjunction with spin labels allows for the detection of ROS kinetics in pancreatic IRI. Reactive oxygen species kinetics are dependent on the length of the ischemic period and the presence or absence of blood.

Antimetastatic effects of liposomal gemcitabine and empty liposomes in an orthotopic mouse model of pancreatic cancer.

OBJECTIVES: Test the efficacy of liposomal gemcitabine (GemLip) on primary tumor and metastases using the pancreatic tumor cell line AsPC1 implanted orthotopically into nude mice. METHODS: The efficacy of gemcitabine and GemLip cells was tested on luciferase-transduced AsPC1 cells in vitro as well as implanted orthotopically into the pancreata of nude mice. RESULTS: In vitro, the IC50s for GemLip and gemcitabine were 20 nM and 140 nM, respectively. However, when applied against established tumors, GemLip (8 mg/kg) blocked tumor growth for 5 consecutive weeks according to bioluminescence measurements in vivo. Gemcitabine (240 mg/kg) had no effect on luciferase-monitored tumor growth. When analyzed at the time of necropsy, GemLip strongly reduced tumor size (-64% +/- [SD] 27%; ***P < 0.0001), whereas gemcitabine only weakly (-36% +/- 37%) affected tumor size. Empty liposomes had no effect on the tumor size. GemLip and empty liposomes both significantly interfered with the metastatic spread to the liver, as measured using luciferase assays (GemLip, *P = 0.01; empty liposomes, *P = 0.036). In addition, they showed effects against spleen, as well as peritoneal metastases. CONCLUSIONS: GemLip presents an effective new formulation of gemcitabine, combining the targeting and protective features of the liposomes with their antimetastatic effects to target pancreatic cancer.

Octreotide attenuates impaired microcirculation in postischemic pancreatitis when administered before induction of ischemia.

BACKGROUND: Ischemia-reperfusion injury of the pancreas causes impairment of microcirculation leading to pancreatitis. Postischemic pancreatitis is the most common reason for graft failure in pancreas transplantation. In animal models, octreotide has been described to have beneficial effects on acute pancreatitis by reducing pancreatic enzyme release and edema formation by preventing the increase of macromolecular extravasation. In contrast to earlier experimental setups, this study investigated the influence of octreotide on ischemia-reperfusion pancreatitis when administered before induction of ischemia. METHODS: Sprague-Dawley rats were randomly assigned to three groups: (1) sham-operated animals (sham group, n=7); (2) 1 hr ischemia followed by 1 hr reperfusion (control group, n=7); (3) administration of 50 microg/kg octreotide intravenously 15 min before ischemia (octreotide group, n=7). At the end of reperfusion, intravital fluorescence microscopy was performed assessing the functional capillary density (FCD), leukocyte-endothelium interaction (LEI), and the microvascular permeability. Finally serum amylase and lipase were measured. RESULTS: The application of octreotide significantly reduced the ischemia-reperfusion-induced reduction of FCD (318.4+/-44.1 cm/cm vs. 257.4+/-11.7 cm/cm, P<0.001). The increase of LEI due to ischemia-reperfusion (466.9+/-52.2 cells/mm) was reduced in the octreotide group (264.4+/-55.1, P=0.001). Permeability was significantly lower in the octreotide group (0.56+/-0.57x10 cm/sec vs. 2.2.1+/-0.54x10 cm/sec, P<0.001). The level of serum lipase was reduced significantly after octreotide therapy (72.4+/-53.4 U/L vs. 136.7+/-66.5 U/L, P=0.026). CONCLUSION: Octreotide significantly attenuated pancreatic dysfunction caused by ischemia-reperfusion when given before ischemia. Furthermore, we could prove for the first time a beneficial role of octreotide on preservation of the microvascular barrier for macromolecules.

In vivo quantification of oxygen-free radical release in experimental pancreas transplantation.

Reactive oxygen species (ROS) were drawn to the attention in the setting of organ transplantation when the 'injury hypothesis' postulated a link between oxidative stress and the activation of the innate immunity of the recipient. While the occurrence of ROS during organ transplantation is undoubted, their onset and magnitude remain largely unknown. We therefore measured ROS using a novel cyclic hydroxylamine spin probe CMH (1-hydroxy-3- methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine) during syngeneic experimental pancreas transplantation in rats in vivo. Organs were subjected to two different cold preservation methods [University of Wisconsin preservation solution (UW) or normal saline] for 18 h. During the first 90 min of reperfusion, samples were collected and analysed using electron paramagnetic resonance signalling. Isolated blood-free perfused organs (IPO) were used for comparison. Analysis showed that it is feasible to detect ROS using CMH spin probes. While IPO organs displayed a very early ROS release, there was no ROS increase in the UW preserved group compared to NaCl. These findings were in line with conventional markers of organ damage such as serum lactate, glucose, potassium as well as tissue ATP levels. CMH spin probes might become a useful tool for the in vivo animal testing of antioxidative substances in models of solid organ transplantation.

Protective role of heme oxygenase-1 in pancreatic microcirculatory dysfunction after ischemia/reperfusion in rats.

OBJECTIVES: Microcirculatory derangements caused by ischemia and reperfusion (I/R) play a pivotal role in acute and graft pancreatitis. The inducible enzyme heme oxygenase 1 (HO-1) has been shown to decrease I/R injury by modulation of capillary perfusion in other organs. It was the aim of this study to evaluate the effect of HO-1 induction on pancreatic microcirculation after I/R. METHODS: Rats were randomized into 4 groups: (1) sham controls; (2) 1-hour ischemia and 2-hour reperfusion (I/R); (3) I/R + cobalt protoporphyrin (CoPP), an HO-1 inducer; and (4) I/R + CoPP + tin protoporphyrin, an HO inhibitor. Functional capillary density (FCD) and leukocyte endothelium interaction were analyzed using intravital microscopy during reperfusion. Expression of HO-1 mRNA, HO-1 protein, and HO activity were assessed by Northern blot, Western blot, and an HO activity assay. RESULTS: Functional capillary density decreased significantly in the I/R group as compared with sham controls. Cobalt protoporphyrin treatment increased FCD to control values. In contrast, HO inhibition in CoPP-pretreated animals lowered FCD and increased leukocyte endothelium interaction significantly. Cobalt protoporphyrin administration increased HO-1 mRNA, protein, and HO activity, whereas activity of the enzyme was reduced after injection of tin protoporphyrin. CONCLUSIONS: Heme oxygenase 1 plays a beneficial role in pancreatic microcirculatory derangements after I/R. This could be of therapeutic relevance after pancreas transplantation and other forms of postischemic pancreatitis.

Targeting vascular endothelial growth factor pathway offers new possibilities to counteract microvascular disturbances during ischemia/reperfusion of the pancreas.

BACKGROUND: It is of crucial importance to explore new therapeutic strategies capable of combating or even preventing pancreatic graft failure after transplantation caused by ischemia reperfusion damage. So far, the role of the hypoxia induced mediator vascular endothelial growth factor (VEGF) upon pancreatic microcirculation has not been described. Therefore the aim of this study was to investigate its influence, using the novel tyrosinekinase inhibitor PTK787/ZK222584 (PTK/ZK), upon functional capillary density (FCD), leukocyte-endothelium interaction (LEI), and macromolecular permeability (P) of normal and postischemic pancreas tissue. METHODS: Sprague-Dawley rats were anesthetized and randomly assigned to five groups (n=7/group): (a) sham, (b) ischemia/reperfusion (I/R) control, (c) I/R and PTK/ZK treatment, (d) VEGF-superfusion, (e) VEGF-superfusion and PTK/ZK-treatment. A recently established method of digital dynamic intravital epifluorescence microscopy was used for evaluating the effective microvascular permeability together with FCD and LEI. RESULTS: Comparison between sham vs. I/R shows a significant upregulation of VEGF-expression followed by deterioration of microcirculation with decreased FCD, increased P and LEI. Treatment with PTK/ZK resulted in a significant decrease of P under conditions of superfusion with VEGF as well as I/R compared to corresponding groups without treatment. CONCLUSION: VEGF plays a crucial causative role involving an increase in permeability in normal as well as in postischemic pancreatitis via tyrosinkinase receptors. VEGF seems to be partly accountable for a deterioration of FCD and an upregulation of LEI via VEGF-tyrosinekinase receptor independent mechanisms. VEGF might be a promising potential therapeutic target in order to minimize edema formation caused by I/R and pancreatitis in pancreas transplantation.

Nonoperative treatment of 15 benign esophageal perforations with self-expandable covered metal stents.

BACKGROUND: Spontaneous or iatrogenic esophageal perforations after endoscopic procedures are potentially life-threatening events with a considerable mortality rate. The aim of this study was to demonstrate that a nonoperative endoscopic treatment with self-expanding metal stents may have a lower morbidity and mortality rate compared with surgical treatment. METHODS: A nonrandomized observational study was conducted with 15 consecutive patients between January 1997 and June 2004. Benign spontaneous and iatrogenic esophageal perforations after endoscopic procedures were treated with self-expandable metal stents. RESULTS: Seven patients (group 1) underwent stent insertion with an average time delay of 45 minutes. In 8 patients (group 2), the median delay was 123 hours. All patients in group 1 had an uneventful recovery and left hospital 5 days (range, 3 to 9) after stent insertion. One patient in group 2 (1 of 8) died of pneumonia after 6 days. In any other cases, perforations healed successfully after stent placement, but the clinical course was generally complicated with sepsis and multiple organ failure. The average hospital stay was 44 days (range, 15 to 70). CONCLUSIONS: Immediate insertion of a self-expandable metal stent enables an excellent outcome with minimal mortality and morbidity without the need for operation. Even in cases of old esophageal perforations, sealing with self-expandable metal stents is still a good option although the clinical course is much less impressive than in early treated perforations.

Expression of connexin26 in islets of Langerhans is associated with impaired glucose tolerance in patients with pancreatic adenocarcinoma.

OBJECTIVES: Impairment of glucose tolerance is one of the leading clinical presentations in patients with pancreatic carcinoma. The mechanism of disturbed glucose metabolism, however, is still under debate. Using microarray technology, key mechanisms of deregulated molecular functions of cancer cell-specific mRNAs and tumor-induced mRNAs in peritumorous tissue should be identified in pancreatic ductal adenocarcinoma (PDAC) by comparison to chronic pancreatitis and normal pancreas. METHODS: Forty-three mRNAs were abundant in tissue specimens of patients operated due to pancreatic carcinoma but absent or of low abundance in chronic pancreatitis and normal pancreas. One of these mRNAs encodes the gap junction protein connexin26, known as a tumor suppressor, which was 10.8- and 6.9-fold more abundant in pancreatic carcinoma than in normal pancreas and chronic pancreatitis, respectively. Quantitative RT-PCR was performed for connexin26, with mRNA being expressed 26.7- and 2.9-fold more than in normal pancreas (n = 6), in pancreatic carcinoma (n = 7), and chronic pancreatitis (n = 8), respectively. RESULTS: By immunohistochemistry, connexin26 was predominantly localized to the islets in the vicinity of the pancreatic carcinoma tissue. Control sections of tissue with chronic pancreatitis and normal pancreas show connexin26 expression in the islets as well. Interestingly, the level of mRNA abundance (fold over normal pancreas) in RT-PCR correlates (r = 0.62) with the 2h value of the pre-operative oral glucose tolerance test of these patients. CONCLUSION: Whether overexpressed connexin26 in pancreatic cancer is a cause of impaired glucose tolerance remains to be elucidated in further experimental studies.

Giant ancient schwannoma of pancreatic head treated by extended pancreatoduodenectomy.

We report a case of a 55-year-old woman who was transferred from another center to our university clinic after diagnostic laparotomy with a pancreatic head tumor which was seen to encase the portal vein. Although intraoperative biopsies were performed, a histologic diagnosis of the tumor was not possible before giving suspect to a malignant tumor being resectable only with a vascular resection. In a second operation we performed a pylorus-preserving pancreatoduodenectomy. Due to adhesion of the tumor to the portal vein, a segmental resection and end-to-end anastomosis of the portal vein was necessary. Postoperative histologic diagnosis revealed an ancient schwannoma which was removed in toto being a rare report of this benign tumor in the pancreatic head. Ten months after the operation the patient is without any health problems. Partial resection of the portal vein, which is considered to be a safe procedure in high volume centers, stands in contrary to surgical nihilism of pancreatic head tumors suspecting advanced tumors with vascular involvement.

Effects of organ preservation, ischemia time and caspase inhibition on apoptosis and microcirculation in rat pancreas transplantation.

This study was undertaken to examine the impact of ischemia-reperfusion (I/R) injury on microcirculation and apoptosis in experimental pancreas transplantation. Pancreatic grafts were subjected to different preservation solutions and cold ischemia times (CITs): University of Wisconsin (UW), 6-h CITs (group U6); UW, 18-h CITs (group U18); normal saline, 6-h CITs (group S6); and normal saline, 6-h CITs with Z-Asp-2,6-dichlorobenzoyloxymethylketone (pan-caspase inhibitor; group S6 & CI). Nontransplanted animals served as controls. At 1- and 2-h reperfusion microcirculation was assessed by means of intravital microscopy. Apoptosis was detected by in situ nick end-labeling method (TUNEL) at 2-h reperfusion. Deterioration of microcirculation was lowest in group U6 and highest in groups S6 and S6 & CI compared with controls. The apoptotic index (cells per high power fields) of groups U6, U18 and S6 correlated well with functional capillary density (r=- 0,70, p < 0.0001) and leucocyte sticking (r= 0,69, p < 0.0001) at 1-h reperfusion. Caspase inhibition had no impact on microcirculation but significantly reduced AI compared with group S6 (p < 0.001). These data suggest that pancreatic I/R injury-induced apoptotic cell death well predicts the extent of [corrected] microcirculatory impairment. Caspase inhibition might be a promising strategy in reducing I/R injury in pancreas transplantation.

Ischemic preconditioning fails to improve microcirculation but increases apoptotic cell death in experimental pancreas transplantation.

Brief periods of warm ischemia and subsequent short reperfusion before either long-term cold or warm ischemic insult (ischemic preconditioning, IPC) have proven to ameliorate ischemia/reperfusion (I/R) injury in various organs, such as the liver and lung. The aim of this study was to examine the effect of IPC on pancreatic cell apoptosis and microcirculatory impairments in experimental pancreas transplantation. Male Lewis rats served as donors and recipients of heterotopic syngeneic pancreaticoduodenal transplantation. Recipient animals were divided into two experimental groups: group Tx (n=7) received grafts without IPC, group Tx&IPC received grafts with IPC. Animals that had not undergone transplantation but whose pancreata had been exteriorized served as controls (n=5). All pancreatic grafts were preserved in University of Wisconsin solution for 6 h at 4 degrees C. IPC was induced by interruption of the arterial blood flow for 10 min followed by 10 min of reperfusion. One and two hours after reperfusion, graft microcirculation was assessed by means of intravital microscopy (IVM). Rats were immediately killed after the second measurement and DNA breaks of acinar cells were detected by in situ terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate digoxigenin nick end-labelling (TUNEL) assay and gel electrophoresis (laddering). The apoptotic index (AI) was defined as the number of apoptotic cells per high-power field. Analysis of both groups of transplanted grafts showed a significant decrease in functional capillary density (FCD) and a significant increase in leukocyte sticking to postcapillary venules (LAV) at 1 h and 2 h of reperfusion, compared with animals that had not undergone transplantation ( P<0.01). In parallel, AI was significantly increased in transplanted grafts compared to the controls ( P<0.01). Grafts subjected to IPC showed no significant differences, neither for FCD nor LAV, at both time points if compared with grafts of group Tx. However, IPC resulted in a significant increase in AI ( P<0.05). We can conclude that IPC has no effect on pancreatic microcirculation but enhances acinar cell apoptosis in experimental pancreas transplantation. These results indicate that IPC might increase I/R injury after pancreatic cold ischemia.