Bi-allelic inactivation of the MEN1 tumor suppressor gene in human grade II astrocytoma

In humans and gene-targeted mice, loss of multiple endocrine neoplasia type 1 (MEN1) tumor suppressor gene function causes neuroendocrine tumors, frequently of the parathyroid and pituitary glands and the pancreas. The MEN1 gene product interacts with glial fibrillary acidic protein (GFAP) in the brain. We here demonstrate bi-allelic MEN1 inactivation in a grade II astrocytoma in an individual carrying a heterozygous MEN1 germ line deletion mutation (788del6). This tumor represents a novel, non-endocrine MEN1-phenotype, compatible with a role of MEN1-GFAP in glial oncogenesis. Clinically, a genetic predisposition to variant neoplasias should be considered in the management of MEN1 patients.     

High-dose intravenous immunoglobulin pulse therapy in patients with progressive immunoglobulin A nephropathy: a long-term follow-up

In progressive immunoglobulin A nephropathy (IgAN), intravenous immunoglobulin (IVIg) treatment has been used to delay disease progression, but the long-term efficacy is largely unknown. We report the clinical outcomes after IVIg therapy in six male patients with progressive IgAN [median glomerular filtration rate (GFR) 31 ml/min per 1.73 m(2)] followed for a median observation period of 8 years. In this single-arm, non-randomized study, IVIg was given monthly at a dose of 2 g/kg body weight for 6 months. The course of renal function was assessed by linear regression analysis of GFR and proteinuria, and was compared to eight patients with IgAN (median GFR 29 ml/min per 1.73 m(2)) without IVIg as a contemporaneous control group. IgAN disease progression was delayed after IVIg therapy on average for 3 years. The mean loss of renal function decreased from -1.05 ml/min per month to -0.15 ml/min per month (P = 0.024) and proteinuria decreased from 2.4 g/l to 1.0 g/l (P = 0.015). The primary end-point (GFR < 10 ml/min or relapse) occurred 5.2 years (median; range 0.4-8.8) after the first IVIg pulse, and after 1.3 years (median; range 0.8-2.4) in the control group (P = 0.043). In Kaplan-Meier analysis, the median renal survival time with IVIg was prolonged by 3.5 years (IVIg 4.7 years versus control 1.2 years; P = 0.006). IVIg pulse therapy may be considered as a treatment option to reduce the loss of renal function and improve proteinuria in patients with progressive IgAN.     

Mycophenolic acid therapy after cyclophosphamide pulses in progressive IgA nephropathy

BACKGROUND: In progressive IgA nephropathy (IgAN), cyclophosphamide or steroids have been used to reduce the loss of renal function, but disease progression may occur after the end of treatment. The value of mycophenolic acid (MPA) maintenance therapy following initial immunosuppression in progressive IgAN is largely unknown. METHODS: In a prospective single-center trial, 20 patients with advanced IgAN (median glomerular filtration rate [GFR], 22 ml/min) and disease progression after cyclophosphamide pulse (CyP; n=18) or steroid pulse therapy (n=2) were treated with MPA for a median of 27 months. MPA dosages (initially mycophenolate mofetil 500 mg twice daily) were adjusted according to predose plasma concentrations (target concentrations 1.5 to 4 microg/mL). The course of renal function was assessed by linear regression of glomerular filtration rates. RESULTS: Median loss of renal function per month was significantly reduced from -0.8 ml/min to -0.03 ml/min per month after 6 months, to -0.05 ml/min per month after 12 months, and to -0.12 ml/min per month at the end of the study after median 27 months (p<0.05). An improved or stable GFR was observed in 16 of 20 patients during the first 12 months, and sustained in 10 patients during 24 months of follow-up. Proteinuria decreased significantly from 1.1 g/L to 0.4 g/L during MPA treatment (p=0.018). CONCLUSION: Our results indicate that MPA may be beneficial to slow down the loss of renal function in patients with progressive IgAN after previous immunosuppressive treatment.     

Effects of overnight fasting on working memory‐related brain network: An fMRI study

Glucose metabolism serves as the central source of energy for the human brain. Little is known about the effects of blood glucose level (BGL) on higher‐order cognitive functions within a physiological range (e.g., after overnight fasting). In this randomized, placebo‐controlled, double blind study, we assessed the impact of overnight fasting (14h) on brain activation during a working memory task. We sought to mimic BGLs that occur naturally in healthy humans after overnight fasting. After standardized periods of food restriction, 40 (20 male) healthy participants were randomly assigned to receive either glucagon to balance the BGL or placebo (NaCl). A parametric fMRI paradigm, including 2‐back and 0‐back tasks, was used. Subclinically low BGL following overnight fasting was found to be linked to reduced involvement of the bilateral dorsal midline thalamus and the bilateral basal ganglia, suggesting high sensitivity of those regions to minimal changes in BGLs. Our results indicate that overnight fasting leads to physiologically low levels of glucose, impacting brain activation during working memory tasks even when there are no differences in cognitive performance. Hum Brain Mapp 36:839–851, 2015. © 2014 Wiley Periodicals, Inc.     

Schilddrüsenkarzinom – Klinik und Diagnostik

The diagnostics of thyroid cancer in Germany is part of the differential diagnostic management of thyroid nodules which are detectable at very high prevalence in this region. Clinical data, ultrasonography, laboratory tests including calcitonin measurement and thyroid scintigraphy all provide valuable information for the initial assessment of the malignancy risk. When used in the context of rational diagnostic algorithms these methods help to select patients requiring further diagnostic assessment by fine needle biopsy. The ultimate goal of fine needle cytology is to improve the pre-operative distinction of benign and malignant thyroid lesions in order to reduce the high rate of diagnostic surgical interventions.     

Investigating the impact of overnight fasting on intrinsic functional connectivity: a double-blind fMRI study

The human brain depends mainly on glucose supply from circulating blood as an energy substrate for its metabolism. Most of the energy produced by glucose catabolism in the brain is used to support intrinsic communication purposes in the absence of goal-directed activity. This intrinsic brain function can be detected with fMRI as synchronized fluctuations of the BOLD signal forming functional networks. Here, we report results from a double-blind, placebo controlled, cross-over study addressing changes in intrinsic brain activity in the context of very low, yet physiological, blood glucose levels after overnight fasting. Comparison of four major resting state networks in a fasting state and a state of elevated blood glucose levels after glucagon infusion revealed altered patterns of functional connectivity only in a small region of the posterior default mode network, while the rest of the networks appeared unaffected. Furthermore, low blood glucose was associated with changes in the right frontoparietal network after cognitive effort. Our results suggest that fasting has only limited impact on intrinsic brain activity, while a detrimental impact on a network related to attention is only observable following cognitive effort, which is in line with ego depletion and its reliance on glucose.     

Lung injury in acute experimental pancreatitis in rats. I. Morphological studies.

The pathogenesis of pancreatitis-related pulmonary injury was studied at the light- and electronmicroscopic level. Experimental pancreatitis was induced in rats by infusion of supramaximal doses of cerulein for 12 h. Investigations were carried out 3, 6, and 12 h after the start of infusion and 12, 48, and 72 h after the end of pancreatitis induction. Initial manifestations of pancreatitis-associated lung injury revealed a pronounced clustering of polymorphonuclear leukocytes in pulmonary microvessels, followed by severe damage of alveolar endothelial cells. Consecutively, the increase in vascular permeability of the lung resulted in interstitial edema formation. Structural changes were maximal after 12 h and reversed completely after 84 h. In conclusion, the structural appearance of pulmonary injury in cerulein-induced pancreatitis was similar to that reported in early stages of the adult respiratory distress syndrome (ARDS). It is suggested that polymorphonuclear granulocytes play a crucial role in the pathogenesis of pancreatitis-related lung injury.     

Concepts for screening and diagnostic follow-up in multiple endocrine neoplasia type 1 (MEN1).

The recent identification of MEN1 gene mutations as the molecular cause of familial multiple endocrine neoplasia type 1 syndrome (MEN1) has had a significant impact on clinical patient care. In the following consensus statement we will present recommendations for clinical screening and follow-up in patients and relatives with suspected or established MEN1 syndrome. MEN1 mutational analysis should be performed in individuals with newly diagnosed MEN1-typical endocrine neoplasia (e.g., primary hyperparathyroidism, gastroenteropancreatic tumor, pituitary adenoma) if additional diagnostic criteria are met (e.g., age <40 years; positive family history; multifocal or recurrent neoplasia; two or more organ systems affected). Genetic family screening is advisable in first degree relatives of MEN1 patients during early adolescence to reliably assess future MEN1 disease risk. In symptomatic individuals carrying MEN1 germ line mutations, annual clinical and biochemical (calcium, PTH, gastrin, prolactin) follow-up as well as routine pancreatic and pituitary imaging may be complemented as individually needed. In contrast, relatives without family-specific MEN1 mutation do not require routine follow-up. Diagnostic procedures and treatment in symptomatic MEN1 mutation carriers and patients may differ from that in sporadic endocrine neoplasia, calling for individual management. Genetic counselling and dedicated endocrine surgery should be integral parts of current medical care in MEN1 syndrome.