Renal neuroendocrine tumors: clinical and molecular pathology with an emphasis on frequent association with ectopic Cushing syndrome.

Renal neuroendocrine tumors (RenNETs) are rare malignancies with largely unknown biology, hormone expression, and genetic abnormalities. This study aims to improve our understanding of the RenNETs with emphasis of functional, hormonal, and genetic features. Surgically resected RenNETs (N = 13) were retrieved, and immunohistochemistry and next-generation sequencing (NGS) were performed in all cases. In addition, all published RenNETs were systematically reviewed. Our cohort (4 men and 9 women, mean age 42, mean tumor size 7.6 cm) included 2 patients with Cushing syndrome (CS). WHO grade (23% G1, 54% G2, and 23% G3) and tumor progression did not correlate. CS-associated RenNETs (CS-RenNETs) showed a solid and eosinophilic histology and stained for ACTH, while the remaining non-functioning tumors had a trabecular pattern and expressed variably hormones somatostatin (91%), pancreatic polypeptide (63%), glucagon (54%), and serotonin (18%). The transcription factors ISL1 and SATB2 were expressed in all non-functioning, but not in CS-RenNETs. NGS revealed no pathogenic alterations or gene fusions. In the literature review (N = 194), 15 (8%) of the patients had hormonal syndromes, in which CS being the most frequent (7/15). Large tumor size and presence of metastasis were associated with shorter patients' survival (p < 0.01). RenNETs present as large tumors with metastases. CS-RenNETs differ through ACTH production and solid-eosinophilic histology from the non-functioning trabecular RenNETs that produce pancreas-related hormones and express ISL1 and SATB2. MEN1 or DAXX/ARTX abnormalities and fusion genes are not detected in RenNETs, indicating a distinct yet unknown molecular pathogenesis.

Gene fusions are frequent in ACTH-secreting neuroendocrine neoplasms of the pancreas, but not in their non-pancreatic counterparts.

Ectopic Cushing syndrome is a rare clinical disorder resulting from excessive adrenocorticotrophic hormone (ACTH) produced by non-pituitary neoplasms, mainly neuroendocrine neoplasms (NENs) of the lung, pancreas, and gastrointestinal tract, and other less common sites. The genetic background of ACTH-producing NENs has not been well studied. Inspired by an index case of ACTH-producing pancreatic NEN carrying a gene fusion, we postulated that ACTH-producing NENs might be enriched for gene fusions. We herein examined 21 ACTH-secreting NENs of the pancreas (10), lung (9), thymus (1), and kidney (1) using targeted RNA sequencing. The tumors were classified according to the most recent WHO classification as NET-G1/typical carcinoid (n = 4), NETG-2/atypical carcinoid (n = 14), and NET-G3 (n = 3). Overall, targeted RNA sequencing was successful in 11 cases (4 of 10 pancreatic tumors, 5 of 9 pulmonary tumors, and in the one renal and one thymic tumor). All four successfully tested pancreatic tumors revealed a gene fusion: two had a EWSR1::BEND2 and one case each had a KMT2A::BCOR and a TFG::ADGRG7 fusion, respectively. EWSR1 rearrangements were confirmed in both tumors with a EWSR1::BEND2 by FISH. Gene fusions were mutually exclusive with ATRX, DAXX, and MEN1 mutations (the most frequently mutated genes in NETs) in all four cases. Using RNA-based variant assessment (n = 16) or via the TSO500 panel (n = 5), no pathogenic BCOR mutations were detected in any of the cases. Taken together, gene fusions were detected in 4/4 (100%) pancreatic versus 0/7 (0%) non-pancreatic tumors, respectively. These results suggest a potential role for gene fusions in triggering the ACTH production in pancreatic NENs presenting with ectopic Cushing syndrome. While the exact mechanisms responsible for the ectopic ACTH secretion are beyond the scope of this study, overexpressed fusion proteins might be involved in promoter-mediated overexpression of pre-ACTH precursors in analogy to the mechanisms postulated for EWSR1::CREB1-mediated paraneoplastic phenomena in certain mesenchymal neoplasms. The genetic background of the ACTH-producing non-pancreatic NENs remains to be further studied.

Anterior Pituitary Hormones in Blood and Cerebrospinal Fluid of Patients in Neurocritical Care.

BACKGROUND: Anterior pituitary hormones in blood follow a circadian rhythm, which may be influenced by various factors such as intracranial pathologies. In cerebrospinal fluid (CSF), pituitary hormones have been collected only selectively and circadian rhythm has not yet been investigated. This pilot study analysed diurnal variations of anterior pituitary hormones in patients in neurocritical care to determine whether circadian rhythmicity exists in these patients. Possible influences of intracranial pathologies were also investigated. Blood and CSF concentrations were assessed simultaneously to explore the value of blood concentrations as a surrogate parameter for CSF levels. METHODS: Blood and CSF samples of 20 non-sedated patients were collected at 06:00, noon, 18:00 and midnight, and analysed for adrenocorticotropic hormone (ACTH), cortisol, thyroid-stimulating hormone (TSH) and insulin-like growth factor-1 (IGF-1) concentrations at each of the four time points. ACTH and IGF-1 were measured by sandwich chemiluminescence immunoassay. Cortisol and TSH were measured by electrochemiluminescence immunoassay. RESULTS: Results showed inconsistent circadian rhythms. Less than 50% of the patients showed a circadian rhythmicity of ACTH, cortisol, TSH or IGF-1. Significance of diurnal variations was only present for blood concentrations of TSH. Correlations between blood and CSF concentrations were strong for cortisol and TSH. CONCLUSIONS: CSF concentrations were only in the measurable range in some of the patients. No clear circadian rhythmicity could be identified, except for TSH in blood. Absence of significant diurnal variations could be explained by the underlying pathologies or disturbing influences of the intensive care unit. Blood concentrations of cortisol and TSH may be suitable surrogate parameters for CSF.

Obesity and Impaired Metabolic Health Increase Risk of COVID-19-Related Mortality in Young and Middle-Aged Adults to the Level Observed in Older People: The LEOSS Registry.

Advanced age, followed by male sex, by far poses the greatest risk for severe COVID-19. An unresolved question is the extent to which modifiable comorbidities increase the risk of COVID-19-related mortality among younger patients, in whom COVID-19-related hospitalization strongly increased in 2021. A total of 3,163 patients with SARS-COV-2 diagnosis in the Lean European Open Survey on SARS-CoV-2-Infected Patients (LEOSS) cohort were studied. LEOSS is a European non-interventional multi-center cohort study established in March 2020 to investigate the epidemiology and clinical course of SARS-CoV-2 infection. Data from hospitalized patients and those who received ambulatory care, with a positive SARS-CoV-2 test, were included in the study. An additive effect of obesity, diabetes and hypertension on the risk of mortality was observed, which was particularly strong in young and middle-aged patients. Compared to young and middle-aged (18-55 years) patients without obesity, diabetes and hypertension (non-obese and metabolically healthy; n = 593), young and middle-aged adult patients with all three risk parameters (obese and metabolically unhealthy; n = 31) had a similar adjusted increased risk of mortality [OR 7.42 (95% CI 1.55-27.3)] as older (56-75 years) non-obese and metabolically healthy patients [n = 339; OR 8.21 (95% CI 4.10-18.3)]. Furthermore, increased CRP levels explained part of the elevated risk of COVID-19-related mortality with age, specifically in the absence of obesity and impaired metabolic health. In conclusion, the modifiable risk factors obesity, diabetes and hypertension increase the risk of COVID-19-related mortality in young and middle-aged patients to the level of risk observed in advanced age.

Transsphenoidal pituitary adenoma resection: do early post-operative cortisol levels predict permanent long-term hypocortisolism?

Transsphenoidal surgery provides a minimal invasive treatment for pituitary adenoma. Our aim is to evaluate the endocrinological outcomes after adenoma resection focusing on the corticotroph function, and to identify prognostic factors for an impaired hypothalamic-pituitary-adrenal-axis function (HPA) and the reliability of postoperative early morning serum cortisol measurements. We performed a retrospective analysis of all patients treated for pituitary adenoma from April 2006 to January 2019 in our neurosurgical department. Pituitary function was assessed pre- and postoperatively as well as at 6 weeks to 12 weeks and at 1-year follow-up. Two hundred eleven patients were included. Nine percent of the patients recovered from a preoperative adrenal insufficiency, 10.4% developed a new need for hormone substitution, and a long-term deficiency of the hypothalamic-pituitary-adrenal-axis was observed in 30.9%. Cortisol measurements 5 days after surgery had a lower area under the curve (AUC) than cortisol levels detected after 6 to 12 weeks (AUC 0.740 vs. AUC 0.808) in predicting an intact corticotrope function. The cut-off value determined for cortisol measured after 6 weeks was 6.95 µg/dl (sensitivity of 94%, specificity of 68%). Postoperative early morning cortisol levels seem to be less sensitive and specific in predicting long-term corticotroph function than measurements after 6 weeks and 1 year, emphasizing the importance of endocrine follow-up testing.

Visual acuity and its postoperative outcome after transsphenoidal adenoma resection.

Transsphenoidal surgery (TSS) represents the gold standard of pituitary adenoma resection, providing a safe and minimal invasive treatment for patients suffering from symptoms of mass effect. The aim of this study is to analyze the postoperative improvement of visual function after adenoma resection and to identify prognostic factors for the postoperative clinical recovery. We performed a retrospective analysis of all consecutive patients treated via a transsphenoidal approach for pituitary adenomas from April 2006 to December 2019 in a high-volume neurosurgical department. Our primary outcome was postoperative visual acuity and visual field impairment; the clinical findings were followed up to 3 months after surgery and correlated with clinical and radiographic findings. In total, 440 surgeries were performed in our department for tumors of the sella region in a time period of 13 years via transsphenoidal approach, and 191 patients included in the analysis. Mean age was 55 years, and 98% were macroadenomas. Mean preoperative visual acuity in patients with preoperative impairment (n = 133) improved significantly from 0.64/0.65 to 0.72/0.75 and 0.76/0.8 (right eye R/left eye L) postoperatively and at 3 months follow-up (p < 0.001). Visual acuity significantly depended on Knosp classification but not Hardy grading. The strongest predictor for visual function recovery was age. Transsphenoidal pituitary tumor resection remains a safe and effective treatment in patients with preoperative visual impairment. It significantly improves visual acuity and field defects after surgery, and recovery continues at the 3 months follow-up examination.

First Experience Using 18F-Flubrobenguane PET Imaging in Patients with Suspected Pheochromocytoma or Paraganglioma.

Pheochromocytomas and paragangliomas are a rare tumor entity originating from adrenomedullary chromaffin cells in the adrenal medulla or in sympathetic, paravertebral ganglia outside the medulla. Small lesions are especially difficult to detect by conventional CT or MRI and even by SPECT with the currently available radiotracers (e.g., metaiodobenzylguanidine [MIBG]). The novel PET radiotracer 18F-flubrobenguane could change the diagnostic paradigm in suspected pheochromocytomas and paragangliomas because of its homology with MIBG and the general advantages of PET imaging. The aim of this retrospective analysis was to evaluate 18F-flubrobenguane in pheochromocytomas and paragangliomas and to investigate the biodistribution in patients. Methods: Twenty-three patients with suspected pheochromocytoma or paraganglioma underwent PET/CT or PET/MRI at 63 ± 24 min after injection of 256 ± 33 MBq of 18F-flubrobenguane. The SUVmean and SUVmax of organs were measured with spheric volumes of interest. Threshold-segmented volumes of interest were used to measure the SUVmean or SUVmax of the tumor lesions. One reader evaluated all cross-sectional imaging datasets (CT or MRI) separately, as well as the PET hybrid datasets, and reported the lesion number and size. The diagnostic certainty for a positive lesion was scored on a 3-point scale. Results:18F-flubrobenguane showed a reproducible, stable biodistribution, with the highest SUVmax and SUVmean being in the thyroid gland (30.3 ± 2.2 and 22.5 ± 1.6, respectively), pancreas (12.2 ± 0.8 and 9.5 ± 0.7, respectively), and tumor lesions (16.8 ± 1.7 and 10.1 ± 1.1, respectively) and the lowest SUVmax and SUVmean being in muscle (1.1 ± 0.06 and 0.7 ± 0.04, respectively) and the lung (2.5 ± 0.17 and 1.85 ± 0.13, respectively). In a subgroup analysis, a significantly higher average SUVmean was seen for both pheochromocytoma and paraganglioma than for healthy adrenal glands (11.9 ± 2.0 vs. 9.9 ± 1.5 vs. 3.7 ± 0.2, respectively). In total, 47 lesions were detected. The reader reported more and smaller lesions with higher certainty in PET hybrid imaging than in conventional imaging; however, statistical significance was not reached. Of the 23 (23/47, 49%) lesions smaller than 1 cm, 61% (14/23) were found on hybrid imaging only. Conclusion: Our preliminary data suggest 18F-flubrobenguane PET to be a new, effective staging tool for patients with suspected pheochromocytoma or paraganglioma. Major advantages are the fast acquisition and high spatial resolution of PET imaging and the intense uptake in tumor lesions, facilitating detection. Further studies are warranted to define the role of 18F-flubrobenguane PET, particularly in comparison to standard diagnostic procedures such as MRI or 123I-MIBG SPECT/CT.

MRI criteria of subtypes of adenomas and epithelial cysts of the pituitary gland.

This study aimed to assess the clinical applicability of MRI criteria for differentiation of pituitary adenomas and cystic pituitary lesions. One hundred ninety-eight consecutive patients with surgical resection of a pituitary adenoma/cystic pituitary lesion were retrospectively analyzed, blinded to clinical data and histopathological diagnosis. Different morphologic criteria were assessed: signal intensity in T2/T1w images, pattern of contrast enhancement, size, super-/infrasellar extension, and invasion of the cavernous sinus. For validation of the criteria, a second independent patient cohort (n = 102) was analyzed for diagnostic accuracy of the criteria. We identified differences between subtypes of pituitary adenomas regarding morphological MRI criteria. Especially, ACTH-producing adenomas and GH-producing adenomas showed partially specific imaging features. Application of our criteria on the second patient cohort (n = 102) did however not significantly improve diagnostic accuracy. Only differentiation between cystic pituitary lesions and adenomas was facilitated using these criteria, but did not reach statistical significance in this cohort (P = 0.352). MRI criteria might facilitate differentiation between pituitary adenomas and cystic pituitary lesions, but not between subtypes of pituitary adenomas. These subtypes show partially specific MR imaging features, however, due to a high variability knowledge of clinical symptoms and laboratory findings remain essential for the correct diagnosis.

Effects of antiretroviral combination therapies F/TAF, E/C/F/TAF and R/F/TAF on insulin resistance in healthy volunteers: the TAF-IR Study.

BACKGROUND: Increased insulin resistance (IR), associated with specific antiretroviral drugs or drug classes, is an established risk factor for type 2 diabetes in HIV patients, ultimately increasing morbidity and mortality. To date, data on the risk of IR in tenofovir alafenamide (TAF)-based protocols are unavailable. METHODS: This prospective randomized, open-label study evaluated the effects of IR on 30 healthy volunteers receiving fixed-dose combinations (FDCs) of emtricitabine/tenofovir alafenamide (F/TAF), elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) or rilpivirine/emtricitabine/tenofovir alafenamide (R/F/TAF). IR was measured before and after 14-day treatments using the hyperinsulinemic-euglycaemic clamp technique (HEGC). Changes in IR in each group were evaluated using the mean glucose disposal rate, normalized with body weight (MBW [mg glucose/(min×kg)]). RESULTS: A total of 30 subjects underwent randomization: one subject in the F/TAF arm withdrew consent after randomization and one in the R/F/TAF arm had to be excluded because of technical failure during HEGC, resulting in 28 subjects in the per-protocol population (F/TAF, n=9 subjects; E/C/F/TAF, n=10 subjects; R/F/TAF n=9 subjects). No significant differences were detected on the baseline characteristics. IR did not differ among the groups before treatment. None of the studied antiretroviral combinations resulted in a significant change in IR after 14 days compared with baseline values, as measured by MBW (F/TAF, 11.42 ±3.04 mean [±sd] versus 11.43 ±3.23, P=0.49; E/C/F/TAF, 10.04 ±2.49 versus 10.95 ±4.26, P=0.30; R/F/TAF, 11.03 ±1.96 versus 13.01 ±4.11, P=0.13). CONCLUSIONS: Short-term treatment for F/TAF, E/C/F/TAF or R/F/TAF did not increase IR in healthy male volunteers.

Dynamics of Adrenocorticotropin after Application of Metyrapone.

Purpose: To investigate the kinetics of adrenocorticotropin (ACTH) following oral metyrapone administration and describe differences between ACTH-deficient and non-ACTH-deficient subjects. Methods: Patients from a tertiary endocrine center at a University Hospital in Munich, Germany, were tested for secondary adrenal insufficiency in a regular patient care setting. Metyrapone (Metopirone, HRA Pharma, France) was administered with a dosage of 40 mg/kg bodyweight at 8 a.m. Consecutive levels of ACTH were determined at 0, 60, 120, 180, and 240 min. Patients were categorized according to their need of glucocorticoid substitution in the follow-up phase. Results: A significant rise in ACTH concentration compared to basal values was found at 60 and 120 min following oral metyrapone administration. ACTH concentrations at 60 and 120 min predicted patients without need for glucocorticoid substitution. ACTH concentrations determined later had no additional benefit. Conclusion: In contrast to previous reports, we found a significant rise in ACTH concentration as soon as one hour after oral metyrapone administration. ACTH values seem to estimate the pituitary corticotrophic function when correlating results to the further clinical course of subjects. Further studies are needed to investigate this finding as a potential basis for a ACTH-based metyrapone short test protocol.

Neither boosted elvitegravir nor darunavir with emtricitabine/tenofovir disoproxil fumarate increase insulin resistance in healthy volunteers: results from the STRIBILD-IR study.

BACKGROUND: Insulin resistance (IR) was one of the first reported complications in HIV-positive patients who were receiving antiretroviral therapy (ART). However, the metabolic effects of newer fixed-dose ART combinations are unclear. METHODS: This Phase I prospective randomized open-label study evaluated the effects on IR in 30 healthy volunteers who were receiving newer fixed-dose combinations of tenofovir disoproxil fumarate, emtricitabine, elvitegravir and cobicistat (E/C/F/TDF, 10 patients) or the established ART regimens, such as tenofovir disoproxil fumarate/emtricitabine with lopinavir/ritonavir (F/TDF+LPV/r, 9 patients) or darunavir/ritonavir (F/TDF+DRV/r, 9 patients). IR was measured before and after the 14-day treatments using the hyperinsulinemic-euglycemic clamp technique, and changes in IR were evaluated using the mean glucose disposal rate that was normalized to body weight (MBW) and lipid metabolism. RESULTS: The groups exhibited similar pretreatment IR, although MBW was significantly lower after the 14-day F/TDF+LPV/r treatment compared with baseline (12.5 ±3.3 versus 9.2 ±1.8 mg glucose/min×kg; P=0.037). No significant IR changes were observed for E/C/F/TDF (11.2 ±3.2 versus 11.3 ±2.5) or F/TDF+DRV/r (11.6 ±2.5 versus 11.3 ±2.4). Compared with baseline, F/TDF+LPV/r and F/TDF+DRV/r treatments significantly increased day 14 triglyceride levels (62 [54-73] versus 119 [77-147] mg/dl, P=0.0109; 75 [56-95] versus 96 [93-128] mg/dl, P=0.009, respectively). CONCLUSIONS: Short-term treatment using fixed-dose combinations of E/C/F/TDF or F/TDF+DRV/r did not affect IR, although IR significantly increased after treatment using F/TDF+LPV/r.

Serum eosinophil cationic protein is superior to mast cell tryptase as marker for response to topical corticosteroid therapy in eosinophilic esophagitis.

GOALS: We evaluated the serum levels of eosinophil cationic protein (ECP) and mast cell tryptase (MCT) as surrogate markers for response to treatment in adults with eosinophilic esophagitis (EoE) under topical steroid therapy with fluticasone. BACKGROUND: EoE is a chronic disease characterized histologically by eosinophilic inflammation of the esophagus. Esophageal mastocytosis and mast cell activation have been implicated in EoE pathogenesis. STUDY: Fifteen patients with EoE completed this prospective observational study. Before and after 3 months of therapy with fluticasone, eosinophilic and mast cell counts were analyzed from histologic samples of the esophagus and were correlated with serum markers ECP and MCT. RESULTS: Fluticasone-therapy significantly decreased mean eosinophils [from 42.2 to 16.2 eosinophils/high-power field (hpf); P=0.004] and mast cells (from 13.9 to 5.1 mast cells/hpf; P=0.001) in the esophageal epithelium. There was a significant decrease of mean ECP (from 15.6 to 5.5 µg/L; P=0.024) and MCT-serum-values (from 4.7 to 3.8 µg/L; P=0.029) under therapy. Serum-ECP correlated significantly with histologic eosinophilic counts after fluticasone-therapy (r=0.54; P=0.038) in contrast to serum-MCT. CONCLUSIONS: Serum-ECP but not serum-MCT could be a promising noninvasive biomarker to assess response to topical corticosteroid therapy in EoE. These findings should be confirmed by larger studies; ClincialTrials.gov number, NCT01624129.

Inhibition of telomerase induces alternative lengthening of telomeres during human esophageal carcinogenesis.

Immortalization is an important step toward the malignant transformation of human cells and is critically dependent upon telomere maintenance. Two mechanisms are known to maintain human telomeres. The process of telomere maintenance is either mediated through activation of the enzyme telomerase or through an alternative mechanism of telomere lengthening called alternative lengthening of telomeres (ALT). Whereas 85% of all human tumors show reactivation of telomerase, the remaining 15% are able to maintain telomeres via ALT. Telomerase inhibitors are already investigated in clinical trials, although the regulation as well as potential coexistence and redundancy of both telomere maintenance mechanisms during distinct steps of carcinogenesis are poorly understood. Herein, we demonstrate that telomerase activity and ALT alternate in a cell cycle dependent fashion in human esophageal epithelial cells, and can coexist in a genetically defined model of oral-esophageal squamous carcinogenesis. Moreover, we show that immortalized premalignant cells as well as cancer cells are able to switch from telomerase activation to ALT upon inhibition of telomerase. This indicates that cancer cells treated with telomerase inhibitors can use alternative and adaptive ways to maintain their telomeres and thereby escape telomere-based therapeutic strategies.

Production of avian retroviruses and tissue-specific somatic retroviral gene transfer in vivo using the RCAS/TVA system.

Spatiotemporal retroviral gene transfer into specific somatic mammalian cells using the avian RCAS (replication-competent avian sarcoma-leukosis virus long terminal repeat with splice acceptor)/tumor virus A (TVA) system is a versatile tool for performing lineage tracing and gene function analysis in vivo. RCAS retroviruses carrying the subgroup A envelope transduce only genetically engineered mammalian cells that express the cognate avian retroviral receptor TVA. The RCAS/TVA gene delivery system has been successfully used in various different mouse TVA-expression models. This protocol contains a detailed description of the production of high-titer RCAS retroviruses in chicken fibroblasts and the transduction of proliferating TVA-positive somatic mammalian cells in vivo. By taking advantage of the combination of the RCAS/TVA with the 'universal' Cre/loxP system, the protocol can be used in nearly every proliferating cell type in vivo. The protocol takes 4 weeks from transfection of chicken fibroblasts, which act as the host cells for viral production, to the transduction of TVA-transgenic mice.

Prediction of extubation failure in medical intensive care unit patients.

PURPOSE: The purpose of this study was to evaluate prediction factors for extubation failure (need for reintubation within 48 hours) in medical intensive care unit patients. MATERIALS AND METHODS: Sixty-one patients extubated after mechanical ventilation for more than 48 hours were included in the study. A retrospective analysis of medical records and a prospectively maintained database on respiratory parameters was conducted. RESULTS: Low serum anion gap (P = .001), low serum anion gap corrected for serum albumin (P = .010), and low arterial partial pressure of oxygen (Pao(2))/fraction of inspired oxygen (Fio(2)) ratio (P = .032) were significantly associated with extubation failure. Binary logistic regression analysis revealed low uncorrected and corrected serum anion gap (P = .006 and P = .025, respectively; odds ratio, 0.59 for both) and low Pao(2)/Fio(2) ratio (P = .038; odds ratio, 0.99) as risk factors for extubation failure. Regarding extubation failure, receiver operating characteristic curve (ROC) analysis demonstrated good predictive capabilities of serum anion gap (ROC area under the curve, 0.835; P = .004; cutoff, 7.7 mEq/L; sensitivity, 70.4%; specificity, 85.7%) and corrected serum anion gap (ROC area under the curve, 0.808; P = .009; cutoff, 8.8 mEq/L; sensitivity, 87.5%; specificity, 71.4%). A significantly higher risk for extubation failure was observed in patients with serum anion gap 5.2 mEq/L or less (relative risk, 8.8; 95% confidence interval, 2.4-32.4; P = .004) and corrected serum anion gap 8.6 mEq/L or less (relative risk, 10.0; 95% confidence interval, 2.2-44.9; P = .004). CONCLUSIONS: Low preextubation serum anion gap values and low preextubation Pao(2)/Fio(2) ratio might help to predict extubation failure in medical intensive care unit patients.

In vivo diagnosis of murine pancreatic intraepithelial neoplasia and early-stage pancreatic cancer by molecular imaging.

Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease with poor patient outcome often resulting from late diagnosis in advanced stages. To date methods to diagnose early-stage PDAC are limited and in vivo detection of pancreatic intraepithelial neoplasia (PanIN), a preinvasive precursor of PDAC, is impossible. Using a cathepsin-activatable near-infrared probe in combination with flexible confocal fluorescence lasermicroscopy (CFL) in a genetically defined mouse model of PDAC we were able to detect and grade murine PanIN lesions in real time in vivo. Our diagnostic approach is highly sensitive and specific and proved superior to clinically established fluorescein-enhanced imaging. Translation of this endoscopic technique into the clinic should tremendously improve detection of pancreatic neoplasia, thus reforming management of patients at risk for PDAC.

EGFR overexpression induces activation of telomerase via PI3K/AKT-mediated phosphorylation and transcriptional regulation through Hif1-alpha in a cellular model of oral-esophageal carcinogenesis.

Telomerase plays an important role during immortalization and malignant transformation as crucial steps in the development of human cancer. In a cellular model of oral-esophageal carcinogenesis, recapitulating the human disease, immortalization occurred independent of the activation of telomerase but through the recombination-based alternative lengthening of telomeres (ALT). In this stepwise model, additional overexpression of EGFR led to in vitro transformation and activation of telomerase with homogeneous telomere elongation in already immortalized oral squamous epithelial cells (OKF6-D1_dnp53). More interestingly, EGFR overexpression activated the PI3K/AKT pathway. This strongly suggested a role for telomerase in tumor progression in addition to just elongating telomeres and inferring an immortalized state. Therefore, we sought to identify the regulatory mechanisms involved in this activation of telomerase and in vitro transformation induced by EGFR. In the present study we demonstrate that telomerase expression and activity are induced through both direct phosphorylation of hTERT by phospho-AKT as well as PI3K-dependent transcriptional regulation involving Hif1-alpha as a key transcription factor. Furthermore, EGFR overexpression enhanced cell cycle progression and proliferation via phosphorylation and translocation of p21. Whereas immortalization was induced by ALT, in vitro transformation was associated with telomerase activation, supporting an additional role for telomerase in tumor progression besides elongating telomeres.

Relapsing polychondritis: An autoimmune disease with many faces.

Relapsing polychondritis (RPC) is a rare immune mediated disease which is associated with inflammation in cartilaginous tissue throughout the body. Especially the cartilaginous structures of ear, nose, joints and respiratory tract are affected. In around 30% of the cases an association with other diseases especially systemic vasculitis or myelodysplatic syndrome can be detected. The relative rarity of RPC has not permitted clinical trials to determine the efficacy and safety of therapy strategies. Often the medication in current use is largely empiric and based on case reports. Therefore different immunosuppressants such as cyclophosphamide, azathioprine, cyclosporine, mycophenolate mofetil and also new approaches like tumor necrosis factor alpha blockers (TNF-alpha antagonists) have been used for the treatment of severe manifestations of RPC with varying degrees of efficacy. This review gives a close look to clinical manifestation, diagnosis and also therapy options of RPC.

E-cadherin regulates metastasis of pancreatic cancer in vivo and is suppressed by a SNAIL/HDAC1/HDAC2 repressor complex.

BACKGROUND & AIMS: Early metastasis is a hallmark of pancreatic ductal adenocarcinoma and responsible for >90% of pancreatic cancer death. Because little is known about the biology and genetics of the metastatic process, we desired to elucidate molecular pathways mediating pancreatic cancer metastasis in vivo by an unbiased forward genetic approach. METHODS: Highly metastatic pancreatic cancer cell populations were selected by serial in vivo passaging of parental cells with low metastatic potential and characterized by global gene expression profiling, chromatin immunoprecipitation, and in vivo metastatic assay. RESULTS: In vivo selection of highly metastatic pancreatic cancer cells induced epithelial-mesenchymal transition (EMT), loss of E-cadherin expression, and up-regulation of mesenchymal genes such as Snail. Genetic inactivation of E-cadherin in parental cells induced EMT and increased metastasis in vivo. Silencing of E-cadherin in highly metastatic cells is mediated by a transcriptional repressor complex containing Snail and histone deacetylase 1 (HDAC1) and HDAC2. In line, mesenchymal pancreatic cancer specimens and primary cell lines from genetically engineered Kras(G12D) mice showed HDAC-dependent down-regulation of E-cadherin and high metastatic potential. Finally, transforming growth factor beta-driven E-cadherin silencing and EMT of human pancreatic cancer cells depends on HDAC activity. CONCLUSIONS: We provide the first in vivo evidence that HDACs and Snail play an essential role in silencing E-cadherin during the metastatic process of pancreatic cancer cells. These data link the epigenetic HDAC machinery to EMT and metastasis and provide preclinical evidence that HDACs are promising targets for antimetastatic therapy.

RCAS-mediated retroviral gene delivery: a versatile tool for the study of gene function in a mouse model of pancreatic cancer.

Pancreatic cancer is one of the most common causes of cancer death in Western civilization and the 5-year survival rate is below 5%. To improve the prognosis of pancreatic cancer, there is the need to develop effective nonsurgical treatment options for the disease. In particular, in vivo models to validate potential targets at the genetic level are required. In this study we demonstrate that RCAS-mediated retroviral gene transfer into orthotopic pancreatic cancer tumor grafts is feasible. Furthermore, we show effective RCAS-dependent RNA interference in vivo. We validate in vivo bioluminescence imaging as a reliable tool to monitor tumor progression of orthotopic pancreatic cancer transplants longitudinally. In addition, we show that restoring expression of the tumor suppressor p53 by RCAS-mediated gene transfer and knockdown of the epidermal growth factor receptor by RCAS-dependent RNA interference impairs orthotopic pancreatic tumor growth in vivo. In conclusion, these data demonstrate that combining in vivo bioluminescence imaging with RCAS-mediated gene or short hairpin RNA transfer is a new model to investigate gene function in pancreatic cancer grafts and allows validation of potential new drug targets in vivo.