Lessons learned from Jordan's response to the Syria refugee crisis

The number of refugees across the world has jumped from 15.7 million to 34.6 million in the past 10 years, and their forced displacement situation remain for an average period of 20 years. To ensure sustainable benefits, health system strengthening through development cooperation should be a priority in parallel to humanitarian aid early on in refugee crises.

mRNA translational specialization by RBPMS presets the competence for cardiac commitment in hESCs

The blueprints of developing organs are preset at the early stages of embryogenesis. Transcriptional and epigenetic mechanisms are proposed to preset developmental trajectories. However, we reveal that the competence for the future cardiac fate of human embryonic stem cells (hESCs) is preset in pluripotency by a specialized mRNA translation circuit controlled by RBPMS. RBPMS is recruited to active ribosomes in hESCs to control the translation of essential factors needed for cardiac commitment program, including Wingless/Integrated (WNT) signaling. Consequently, RBPMS loss specifically and severely impedes cardiac mesoderm specification, leading to patterning and morphogenetic defects in human cardiac organoids. Mechanistically, RBPMS specializes mRNA translation, selectively via 3'UTR binding and globally by promoting translation initiation. Accordingly, RBPMS loss causes translation initiation defects highlighted by aberrant retention of the EIF3 complex and depletion of EIF5A from mRNAs, thereby abrogating ribosome recruitment. We demonstrate how future fate trajectories are programmed during embryogenesis by specialized mRNA translation.

Impaired mitochondrial maturation of sulfite oxidase in a patient with severe sulfite oxidase deficiency

Sulfite oxidase (SO) is encoded by the nuclear SUOX gene and catalyzes the final step in cysteine catabolism thereby oxidizing sulfite to sulfate. Oxidation of sulfite is dependent on two cofactors within SO, a heme and the molybdenum cofactor (Moco), the latter forming the catalytic site of sulfite oxidation. SO localizes to the intermembrane space of mitochondria where both—pre-SO processing and cofactor insertion—are essential steps during SO maturation. Isolated SO deficiency (iSOD) is a rare inborn error of metabolism caused by mutations in the SUOX gene that lead to non-functional SO. ISOD is characterized by rapidly progressive neurodegeneration and death in early infancy. We diagnosed an iSOD patient with homozygous mutation of SUOX at c.1084G>A replacing Gly362 to serine. To understand the mechanism of disease, we expressed patient-derived G362S SO in Escherichia coli and surprisingly found full catalytic activity, while in patient fibroblasts no SO activity was detected, suggesting differences between bacterial and human expression. Moco reconstitution of apo-G362S SO was found to be approximately 90-fold reduced in comparison to apo-WT SO in vitro. In line, levels of SO-bound Moco in cells overexpressing G362S SO were significantly reduced compared to cells expressing WT SO providing evidence for compromised maturation of G362S SO in cellulo. Addition of molybdate to culture medium partially rescued impaired Moco binding of G362S SO and restored SO activity in patient fibroblasts. Thus, this study demonstrates the importance of the orchestrated maturation of SO and provides a first case of Moco-responsive iSOD.

Loss of genomic integrity induced by lysosphingolipid imbalance drives ageing in the heart

Cardiac dysfunctions dramatically increase with age. Revealing a currently unknown contributor to cardiac ageing, we report the age-dependent, cardiac-specific accumulation of the lysosphingolipid sphinganine (dihydrosphingosine, DHS) as an evolutionarily conserved hallmark of the aged vertebrate heart. Mechanistically, the DHS-derivative sphinganine-1-phosphate (DHS1P) directly inhibits HDAC1, causing an aberrant elevation in histone acetylation and transcription levels, leading to DNA damage. Accordingly, the pharmacological interventions, preventing (i) the accumulation of DHS1P using SPHK2 inhibitors, (ii) the aberrant increase in histone acetylation using histone acetyltransferase (HAT) inhibitors, (iii) the DHS1P-dependent increase in transcription using an RNA polymerase II inhibitor, block DHS-induced DNA damage in human cardiomyocytes. Importantly, an increase in DHS levels in the hearts of healthy young adult mice leads to an impairment in cardiac functionality indicated by a significant reduction in left ventricular fractional shortening and ejection fraction, mimicking the functional deterioration of aged hearts. These molecular and functional defects can be partially prevented in vivo using HAT inhibitors. Together, we report an evolutionarily conserved mechanism by which increased DHS levels drive the decline in cardiac health.

yylncT Defines a Class of Divergently Transcribed lncRNAs and Safeguards the T-mediated Mesodermal Commitment of Human PSCs

Human protein-coding genes are often accompanied by divergently transcribed non-coding RNAs whose functions, especially in cell fate decisions, are poorly understood. Using an hESC-based cardiac differentiation model, we define a class of divergent lncRNAs, termed yin yang lncRNAs (yylncRNAs), that mirror the cell-type-specific expression pattern of their protein-coding counterparts. yylncRNAs are preferentially encoded from the genomic loci of key developmental cell fate regulators. Most yylncRNAs are spliced polyadenylated transcripts showing comparable expression patterns in vivo in mouse and in human embryos. Signifying their developmental function, the key mesoderm specifier BRACHYURY (T) is accompanied by yylncT, which localizes to the active T locus during mesoderm commitment. yylncT binds the de novo DNA methyltransferase DNMT3B, and its transcript is required for activation of the T locus, with yylncT depletion specifically abolishing mesodermal commitment. Collectively, we report a lncRNA-mediated regulatory layer safeguarding embryonic cell fate transitions.

Targeted overexpression of CRH receptor subtype 1 in central amygdala neurons: effect on alcohol-seeking behavior

RATIONALE

The corticotropin-releasing hormone (CRH) system is a key mediator of stress-induced responses in alcohol-seeking behavior. Recent research has identified the central nucleus of the amygdala (CeA), a brain region involved in the regulation of fear and stress-induced responses that is especially rich in CRH-positive neurons, as a key player in mediating excessive alcohol seeking. However, detailed characterization of the specific influences that local neuronal populations exert in mediating alcohol responses is hampered by current limitations in pharmacological and immunohistochemical tools for targeting CRH receptor subtype 1 (CRHR1).

OBJECTIVE

In this study, we investigated the effect of cell- and region-specific overexpression of CRHR1 in the CeA using a novel transgenic tool.

METHODS

Co-expression of CRHR1 in calcium-calmodulin-dependent kinase II (αCaMKII) neurons of the amygdala was demonstrated by double immunohistochemistry using a Crhr1-GFP reporter mouse line. A Cre-inducible Crhr1-expressing adeno-associated virus (AAV) was site-specifically injected into the CeA of αCaMKII-Cre^ERT2 transgenic rats to analyze the role of CRHR1 in αCaMKII neurons on alcohol self-administration and reinstatement behavior.

RESULTS

Forty-eight percent of CRHR1-containing cells showed co-expression of αCaMKII in the CeA. AAV-mediated gene transfer in αCaMKII neurons induced a 24-fold increase of Crhr1 mRNA in the CeA which had no effect on locomotor activity, alcohol self-administration, or cue-induced reinstatement. However, rats overexpressing Crhr1 in the CeA increased responding in the stress-induced reinstatement task with yohimbine serving as a pharmacological stressor.

CONCLUSION

We demonstrate that CRHR1 overexpression in CeA-αCaMKII neurons is sufficient to mediate increased vulnerability to stress-triggered relapse into alcohol seeking.

Sense-Antisense lncRNA Pair Encoded by Locus 6p22.3 Determines Neuroblastoma Susceptibility via the USP36-CHD7-SOX9 Regulatory Axis

Trait-associated loci often map to genomic regions encoding long noncoding RNAs (lncRNAs), but the role of these lncRNAs in disease etiology is largely unexplored. We show that a pair of sense/antisense lncRNA (6p22lncRNAs) encoded by CASC15 and NBAT1 located at the neuroblastoma (NB) risk-associated 6p22.3 locus are tumor suppressors and show reduced expression in high-risk NBs. Loss of functional synergy between 6p22lncRNAs results in an undifferentiated state that is maintained by a gene-regulatory network, including SOX9 located on 17q, a region frequently gained in NB. 6p22lncRNAs regulate SOX9 expression by controlling CHD7 stability via modulating the cellular localization of USP36, encoded by another 17q gene. This regulatory nexus between 6p22.3 and 17q regions may lead to potential NB treatment strategies.

Characterization of Circular RNAs (circRNA) Associated with the Translation Machinery

A substantial proportion of the currently annotated genes in eukaryotes are proposed to function as RNA molecules (>200 bp) with no significant protein coding potential, currently classified as long noncoding RNAs (lncRNA). A distinct subgroup of lncRNAs is circular RNAs (circRNAs), which can be easily identified by unique junction reads, resulting from their biogenesis. CircRNAs are largely cytosolic and thought to either code for micro-peptides or facilitate gene regulation by sequestering microRNAs (miRNAs) or RNA-binding proteins (RBPs) from their targets. Interrogation of the interaction of circRNAs with cellular macromolecular machineries could indicate their mode of action. Here, we detail a sucrose gradient-based method to pinpoint association of a given circRNA (or any transcript of interest) with distinct ribosomal fractions. This method can evaluate the coding potential of candidate circRNAs (or any transcript of interest) and its association with the translation machinery.

Dicer1-miR-328-Bace1 signalling controls brown adipose tissue differentiation and function

Activation of brown adipose tissue (BAT) controls energy homeostasis in rodents and humans and has emerged as an innovative strategy for the treatment of obesity and type 2 diabetes mellitus. Here we show that ageing- and obesity-associated dysfunction of brown fat coincides with global microRNA downregulation due to reduced expression of the microRNA-processing node Dicer1. Consequently, heterozygosity of Dicer1 in BAT aggravated diet-induced-obesity (DIO)-evoked deterioration of glucose metabolism. Analyses of differential microRNA expression during preadipocyte commitment and mouse models of progeria, longevity and DIO identified miR-328 as a regulator of BAT differentiation. Reducing miR-328 blocked preadipocyte commitment, whereas miR-328 overexpression instigated BAT differentiation and impaired muscle progenitor commitment-partly through silencing of the β-secretase Bace1. Loss of Bace1 enhanced brown preadipocyte specification in vitro and was overexpressed in BAT of obese and progeroid mice. In vivo Bace1 inhibition delayed DIO-induced weight gain and improved glucose tolerance and insulin sensitivity. These experiments reveal Dicer1-miR-328-Bace1 signalling as a determinant of BAT function, and highlight the potential of Bace1 inhibition as a therapeutic approach to improve not only neurodegenerative diseases but also ageing- and obesity-associated impairments of BAT function.

Reliability of maximal lactate-steady-state

The aim of this study was the analysis of reliability and day-to-day-variability of power (PMLSS), blood lactate concentration (BLCMLSS) and heart rate (HRMLSS) in maximal lactate- steady-state during cycle ergometry. 32 male subjects (25±3 years, 180±7 cm, 76±8 kg) have undergone several constant-load-tests lasting 30 min to determine 4 PMLSS. During the test, blood-samples were taken from the earlobe after 4, 8,10, 14, 18, 22, 26 und 30 min for detecting the BLCMLSS. PMLSS was defined as the highest workload that can be maintained without accumulation of BLC by more than 0.05 mmol/l/min during the last 20 min. Mean PMLSS was 244±45 W, according to 75% of VO2max. Mean of BLCMLSS was 5.3±1.5 mmol/l/min, mean of HRMLSS was 166±10 1/min. The coefficient of variability (CV) was calculated for PMLSS, BLCMLSS and HRMLSS with 3%, 16.6% and 6.3%, respectively. The Intra-Class-Coefficient for PMLSS, BLCMLSS and for HRMLSS was determined with 0.98 (p≤0.001), 0.71 (p≤0.001), 0.92 (p≤0.001) respectively. PMLSS and HRMLSS are characterized by a low day-to-day variability that is comparable with results of different lactate threshold concepts. In comparison to PMLSS, BLCMLSS shows a greater day-to-day-variability.

Search for lepton flavour violation in the eμ continuum with the ATLAS detector in [Formula: see text]pp collisions at the LHC

This paper presents a search for the t-channel exchange of an R-parity violating scalar top quark ([Formula: see text]) in the e±μ∓ continuum using 2.1 fb-1 of data collected by the ATLAS detector in [Formula: see text]pp collisions at the Large Hadron Collider. Data are found to be consistent with the expectation from the Standard Model backgrounds. Limits on R-parity-violating couplings at 95 % C.L. are calculated as a function of the scalar top mass ([Formula: see text]). The upper limits on the production cross section for pp→eμX, through the t-channel exchange of a scalar top quark, ranges from 170 fb for [Formula: see text] to 30 fb for [Formula: see text].

Peripheral bone mineral density in correlation to disease-related predisposing conditions in patients with multiple endocrine neoplasia type 1

BACKGROUND AND AIM

Patients with multiple endocrine neoplasia type 1 (MEN1) often have low bone mineral density (BMD) attributed to primary hyperparathyroidism (pHPT). However, in MEN1 patients, other endocrine dysfunctions and conditions such as hypercortisolism, hypogonadism, and GH deficiency due to pituitary manifestation, and surgery on the upper gastrointestinal tract may affect BMD.

SUBJECTS AND METHODS

In 23 patients with MEN1 (10 females, 13 males; 46±12 yr), BMD was determined by quantitative computed tomography at the forearm (pqCT), compared to a reference population and related to different conditions suspected to affect bone metabolism in MEN1.

RESULTS

In this cohort, Z-score for trabecular BMD was -0.85±1.18 and for total BMD -1.16±1.04. There was a similar trend towards lower BMD in uncontrolled hyperparathyroidism, hypercortisolism, hypogonadism/GH deficiency and the state after surgery at the upper gastrointestinal tract.

CONCLUSIONS

These data while confirming previous observations on reduced BMD in patients with MEN1, however, challenge its only or even predominant association with pHPT. Other conditions such as hypercortisolism, somatotrophic/ gonadotrophic pituitary insufficiency, and previous upper gastrointestinal surgery seem to be factors contributing to the risk of developing osteoporosis.

A mathematical model of exposure of non-target Lepidoptera to Bt-maize pollen expressing Cry1Ab within Europe

Genetically modified (GM) maize MON810 expresses a Cry1Ab insecticidal protein, derived from Bacillus thuringiensis (Bt), toxic to lepidopteran target pests such as Ostrinia nubilalis. An environmental risk to non-target Lepidoptera from this GM crop is exposure to harmful amounts of Bt-containing pollen deposited on host plants in or near MON810 fields. An 11-parameter mathematical model analysed exposure of larvae of three non-target species: the butterflies Inachis io (L.), Vanessa atalanta (L.) and moth Plutella xylostella (L.), in 11 representative maize cultivation regions in four European countries. A mortality-dose relationship was integrated with a dose-distance relationship to estimate mortality both within the maize MON810 crop and within the field margin at varying distances from the crop edge. Mortality estimates were adjusted to allow for physical effects; the lack of temporal coincidence between the susceptible larval stage concerned and the period over which maize MON810 pollen is shed; and seven further parameters concerned with maize agronomy and host-plant ecology. Sublethal effects were estimated and allowance made for aggregated pollen deposition. Estimated environmental impact was low: in all regions, the calculated mortality rate for worst-case scenarios was less than one individual in every 1572 for the butterflies and one in 392 for the moth.

Inclusive K(S);(0)K(S);(0) resonance production in ep collisions at HERA

Inclusive K_{S};{0}K_{S};{0} production in ep collisions at the DESY ep collider HERA was studied with the ZEUS detector using an integrated luminosity of 0.5 fb;{-1}. Enhancements in the mass spectrum were observed and are attributed to the production of f_{2}(1270)/a_{2};{0}(1320), f_{2};{'}(1525) and f_{0}(1710). Masses and widths were obtained using a fit which takes into account theoretical predictions based on SU(3) symmetry arguments, and are consistent with the Particle Data Group values. The f_{0}(1710) state, which has a mass consistent with a glueball candidate, was observed with a statistical significance of 5 standard deviations. However, if this state is the same as that seen in gammagamma-->K_{S};{0}K_{S};{0}, it is unlikely to be a pure glueball state.

Pancreatitis in primary hyperparathyroidism-related hypercalcaemia is not associated with mutations in the CASR gene

BACKGROUND

Primary hyperparathyroidism (pHPT) related hypercalcaemia is considered to represent a risk factor for the development of pancreatitis. We therefore explored whether mutations in the calcium-sensing receptor gene ( CASR) coding for the calcium-sensing receptor (CaR), an essential regulator of the calcium homeostasis in parathyroid chief cells, exist in a cohort of patients with pHPT and pancreatitis.

METHODS

Among 826 patients prospectively studied between 1987 and 2002 with pHPT, 38 patients were identified with pancreatitis (4.6%). DNA was available of 25 patients (13 females and 12 males). These individuals were analysed for mutations in the CASR by single-strand conformation polymorphism (SSCP) analysis and DNA sequencing.

RESULTS

None of the 25 patients with pHPT and pancreatitis carried a CASR mutation and only one had a known heterozygous polymorphism R990G.

CONCLUSIONS

Pancreatitis in primary hyperparathyroidism is not associated with mutations in the CASR gene, while it remains to be determined why the polymorphisms A986S, R990G and Q1011E were less often present in that subgroup than in the normal population.

Monitoring the Cry1Ab susceptibility of European corn borer in Germany

The European corn borer, Ostrinia nubilalis (Hübner), is one of the most important insect pests in corn, Zea mays L. Transgenic corn cultivars expressing Bacillus thuringiensis (Bt) toxin provide a promising crop protection strategy against European corn borer; however, management is needed to avoid resistance development of the target pest species. The aim of this work was to establish the baseline susceptibility of different European corn borer populations in Germany to be able to forecast a possible development of resistance at an early stage. To standardize test procedures for future resistance management, the efficiency of Cry1Ab toxins from different suppliers and different production was assessed. Furthermore, two different test methods, surface treatment and the incorporation method, were compared with regard to their practicability and efficiency. Neither method provided significant differences in the baseline susceptibility of populations from different German regions. Overall, the data suggested little differentiation among German populations in terms of their susceptibility to Bt toxin and their genetic background. Future monitoring could therefore use a single European corn borer population as a representative for southwestern Germany. However, toxins from different suppliers and different production batches produced a vast range of LC50 values. Changes because of different toxin batches may be mistaken as a change in baseline susceptibility or even as the start of a resistance development. Thus, it is important throughout insect resistance management that the same toxin batches will be available for baseline susceptibility bioassays and for future tests.

Stress-induced hyperlocomotion as a confounding factor in anxiety and depression models in mice

Chronic stress is broadly used to model anxiety and depression. However, in chronic stress models, anxiety- and depression-like behaviors might be masked by unspecific effects of stress. We tested whether chronic stress in mice can induce unspecific changes in locomotion, and whether these changes interfere with the measurement of anxiety and forced-swimming behaviors. Also, we studied these latter behaviors in relation to the duration of stress, the lighting conditions during testing, and after the injection of diazepam. We employed a 4-week chronic stress paradigm, adopted from a model of stress-induced anhedonia and a 1-week subchronic stress, both consisting of rat exposure, restraint stress and tail suspension. Chronically stressed mice, tested under bright and moderate illumination, exhibited 'anxiolytic-like' behavior along with prolonged swimming and hyperactivity. These behaviors were not detectable under weak illumination or after the injection of diazepam (0.25 mg/kg). Instead, normal locomotion, increased anxiety and inhibited swimming were revealed under these conditions. Thus, chronic stress can induce hyperlocomotion in mice, which is triggered by acute stressors such as light, and interferes with the evaluation of anxiety and forced swimming. One week of stress did not change locomotion and forced swimming, and increased anxiety irrespective of illumination applied during testing. Our data can possibly explain previously reported contradictions in the behavioral testing of mice with chronic stress models of anxiety and depression.

Renin producing neuroendocrine pancreatic carcinoma--a case report and review of the literature

A 44 year old male patient presented with severe hypertension. The diagnostic work-up revealed elevated levels of plasma renin activity (about 10 times the upper limit of normal) in the presence of normal plasma aldosterone levels and serum potassium concentrations. Renovascular disease was excluded by angiography. Selective renal vein sampling did not show any renin gradient. CT-scans of the abdomen demonstrated normal morphology of the kidneys and adrenals but revealed a big mass in the pancreatic corpus and tail with infiltration of the splenic vein and the presence of enlarged local lymph nodes. The endocrine nature of the pancreatic mass was further supported by a positive octreotide scintigraphy scan. Surgical removal of the tumor by left sided pancreatectomy combined with splenectomy resulted in rapid normalization of elevated renin concentrations as well as blood pressure. Histological examination of the tumor tissue revealed the presence of a neuroendocrine pancreatic carcinoma. Highly (x 70) elevated renin levels were detected by radioimmunoassay in the tumor tissue. To our knowledge this is the first renin-producing neuroendocrine pancreatic carcinoma described in the literature. The present paper describes the case in detail and reviews the available literature on clinical symptomatology, diagnosis and treatment of renin-producing tumors.

Tumor suppressor genes in the 9p21 gene cluster are selective targets of inactivation in neuroendocrine gastroenteropancreatic tumors

Functional inactivation of the Rb and p53 pathways appears to be a rite of passage for all cancerous cells. However, p53 and Rb alterations are rare events in neuroendocrine gastroenteropancreatic (GEP) tumors. The CDKN2 locus on chromosome 9p21 sits at the nexus of both pathways harboring tumor suppressor genes, which restrain cell growth by affecting the function of pRb and p53. Therefore, we analyzed the implication of their inactivation in 37 primary neuroendocrine GEP tumors and two cell culture models. RT-PCR analysis revealed loss of expression of at least one of the tumor suppressor genes CDKN2A/p16, CDKN2B/p15, and CDKN2D/p14 with distinct genetic profiles, most frequently in nonfunctional pancreatic tumors (57%) and small intestinal carcinoids (44%), and less commonly in insulinomas (30%) and gastrinomas (22%). DNA analysis and methylation-specific PCR attributed loss of expression to either homozygous deletion or 5'CpG island hypermethylation. 5-Aza-2-deoxycytidine treatment reversed CDKN2A/p16 and CDKN2B/p15 silencing with concurrent growth restraint. Thus, tumor suppressor genes localized in the 9p21 gene cluster are specific targets of inactivation in neuroendocrine GEP tumors, and demethylating agents might hold promise for selective therapy.

Predictive Genetic Screening and Clinical Findings in Multiple Endocrine Neoplasia Type I Families

Germline mutations of the MEN1 gene have been identified as the causative genetic defect of multiple endocrine neoplasia type I (MEN-I), an autosomal dominantly inherited condition. To establish the basis for predictive family screening we evaluated the spectrum of MEN1 gene mutations in MEN-I patients treated at our institution. Relatives at risk were subjected to predictive genetic screening after genetic counseling. Gene carriers were subjected to extensive clinical screening for MEN-I, including biochemical tests for basal hormone concentrations in blood and urine, a standardized meal stimulation test and imaging procedures (ultrasonography, computed tomography, magnetic resonance imaging). Among index patients of 15 independent MEN-I kindreds, 14 heterozygous MEN1 germline mutations were identified by single-strand conformational variant analysis (SSCV) and direct DNA sequence analysis. Of 51 individuals at risk, 26 predictively tested relatives with the wild-type MEN1 gene could be excluded from further screening procedures because they had not inherited the disease. In all previously presumed unaffected relatives with the mutant gene, our extensive clinical screening program revealed at least one manifestation of MEN-I. Furthermore, 22 additional diagnoses could be established in identified MEN-I patients. We show that mutation analysis enables predictive genetic screening for MEN-I families, providing a valuable tool for genetic counseling and clinical management. An extensive clinical screening program focusing on genetically proven individuals at risk allows detection of MEN-I manifestations at an early, asymptomatic stage of the disease. Controlled, prospective studies are now required to prove whether timely appropriate treatment on the basis of predictive screening might help improve disease-related quality of life and prolong life expectancy in MEN-I kindreds.

Transgenic activation of Ras in neurons promotes hypertrophy and protects from lesion-induced degeneration

Ras is a universal eukaryotic intracellular protein integrating extracellular signals from multiple receptor types. To investigate its role in the adult central nervous system, constitutively activated V12-Ha-Ras was expressed selectively in neurons of transgenic mice via a synapsin promoter. Ras-transgene protein expression increased postnatally, reaching a four- to fivefold elevation at day 40 and persisting at this level, thereafter. Neuronal Ras was constitutively active and a corresponding activating phosphorylation of mitogen-activated kinase was observed, but there were no changes in the activity of phosphoinositide 3-kinase, the phosphorylation of its target kinase Akt/PKB, or expression of the anti-apoptotic proteins Bcl-2 or Bcl-X(L). Neuronal Ras activation did not alter the total number of neurons, but induced cell soma hypertrophy, which resulted in a 14.5% increase of total brain volume. Choline acetyltransferase and tyrosine hydroxylase activities were increased, as well as neuropeptide Y expression. Degeneration of motorneurons was completely prevented after facial nerve lesion in Ras-transgenic mice. Furthermore, neurotoxin-induced degeneration of dopaminergic substantia nigra neurons and their striatal projections was greatly attenuated. Thus, the Ras signaling pathway mimics neurotrophic effects and triggers neuroprotective mechanisms in adult mice. Neuronal Ras activation might become a tool to stabilize donor neurons for neural transplantation and to protect neuronal populations in neurodegenerative diseases.

Monitoring gene flow from transgenic sugar beet using cytoplasmic male-sterile bait plants

One of the most discussed environmental effects associated with the use of transgenic plants is the flow of genes to plants in the environment. The flow of genes may occur through pollen since it is the reproductive system that is designed for gene movement. Pollen-mediated gene escape is hard to control in mating plants. Pollen from a wind pollinator can move over distances of more than 1000 m. To investigate the efficiency of transgenic pollen movement under realistic environmental conditions, the use of bait plants might be an effective tool. In this study, cytoplasmic male-sterile (CMS) sugar beets were tested with regard to their potential for monitoring transgene flow. As the pollen source, transgenic sugar beets were used that express recombinant DNA encoding viral (beet necrotic yellow vein virus) resistance, and antibiotic (kanamycin) and herbicide (glufosinate) tolerance genes. In a field trial, the effectiveness of a hemp (Cannabis sativa) stripe containment strategy was tested by measuring the frequency of pollinated CMS bait plants placed at different distances and directions from a transgenic pollen source. The results demonstrated the ineffectiveness of the containment strategy. Physiological and molecular tests confirmed the escape and production of transgenic offspring more than 200 m behind the hemp containment. Since absolute containment is unlikely to be effective, the CMS-bait plant detection system is a useful tool for other monitoring purposes.

Imaging physiologic dysfunction of individual hippocampal subregions in humans and genetically modified mice

We have developed a variant of functional magnetic resonance imaging (fMRI) designed to be sensitive to static neuronal function. This method is based on resting instead of dynamic changes in oxygen-dependent signal and therefore allows for a spatial resolution that can detect signal from different hippocampal subregions in human subjects as well as in mice. We found that hippocampal signal was significantly diminished in elderly subjects with memory decline compared to age-matched controls, and different subjects showed dysfunction in different subregions. Among healthy elders, signal intensity from the subiculum was correlated selectively with memory performance. This method does not require an activation task; it can be used in anesthetized normal and in genetically modified and cognitively impaired mice. In mice the signal was found to be sufficiently sensitive to detect functional changes in the absence of underlying anatomical changes.

Enhancement of memory-related long-term facilitation by ApAF, a novel transcription factor that acts downstream from both CREB1 and CREB2

The memory for sensitization of the gill withdrawal reflex in Aplysia is reflected in facilitation of the monosynaptic connection between the sensory and motor neurons of the reflex. The switch from short- to long-term facilitation requires activation of CREB1, derepression of ApCREB2, and induction of ApC/EBP. In search for genes that act downstream from CREB1, we have identified a transcription activator, ApAF, which is stimulated by protein kinase A and can dimerize with both ApC/EBP and ApCREB2. ApAF is necessary for long-term facilitation induced by five pulses of serotonin, by activation of CREB1, or by derepression of ApCREB2. Overexpression of ApAF enhances the long-term facilitation further. Thus, ApAF is a candidate memory enhancer gene downstream from both CREB1 and ApCREB2.

Adrenocortical carcinoma--our experience with 11 cases

BACKGROUND AND AIMS

Adrenocortical carcinoma (ACC) is a rare tumour with an incidence of approximately 0.5-2 cases per million per year. Diagnosis is mostly delayed and prognosis is poor. We report our experiences with 11 patients operated on within the last 10 years.

PATIENTS/METHODS

The data of the patients with ACC were reviewed and presenting symptoms, diagnostic procedures, treatment and results of follow-up were evaluated.

RESULTS

The group of patients consisted of eight women and three men with a mean age of 40.2 (15-57) years. Median follow-up was 16 (1-71) months. Six patients presented with Cushing's syndrome, two presented with virilism and hirsutism caused by androgen-producing tumours. Three patients had hormonally inactive tumours. At the time of diagnosis, five tumours were classified as stage II, two as stage III and four as stage IV. Four patients had tumours with intravascular extension, prompting recurrence in two cases. Eight adrenalectomies, one resection of local recurrence, one adrenalectomy with splenectomy and one adrenalectomy and resection of a liver metastasis were performed. Five patients received additional chemotherapy. Five of the 11 patients are still alive (three stage II, one stage III and one stage IV at the time of diagnosis), three of whom have no evidence of disease (14, 48 and 71 months after surgery). The other six patients died after a median postoperative period of 10 (1-21) months.

CONCLUSIONS

Venography should be performed prior to surgery to detect or exclude thrombotic tumour masses in the suprarenal vein, renal vein or inferior vena cava. Radical surgery is the only curative approach and is recommended for all patients with resectable tumours, including those patients with recurrent disease. There is no consensus concerning adjuvant therapy. The value of multidisciplinary strategies needs to be assessed in multicentre trials.

[Diagnosis and therapy of well-differentiated neuroendocrine lung tumors]

INTRODUCTION

Neuroendocrine tumours of the lung are uncommon malignant neoplasms. They represent a heterogeneous spectrum of disease, encompassing the well-differentiated neuroendocrine tumours through to small-cell lung cancer, which has a poor prognosis and only palliative therapeutic options for most patients. Due to the low incidence of well-differentiated lung tumours there is as yet little experience.

METHODS

Clinical records of 14 patients with well-differentiated neuroendocrine tumours of the lung were assessed retrospectively for patients' initial symptomatology, diagnostic procedures, therapy and results.

RESULTS

Eight lobectomies, 2 bronchoplastic lobectomies, 2 segmental resections, 1 bilobectomy and 1 wedge resection were performed; seven of them without regional lymphadenectomy. All patients were alive after a mean follow-up of 38 (2-96) months. Thirteen of 14 patients were free of complaints, twelve had no recurrences and returned to work.

CONCLUSIONS

Well-differentiated NET of the lung have an excellent prognosis after curative resection. Limited resections even without lymphadenectomy can be performed in some cases.

Analysis of beta-catenin gene mutations in pancreatic tumors

BACKGROUND/AIM

Mutations of the adenomatous polyposis coli (APC) tumor suppressor gene have been described in a subset of pancreatic carcinomas. The APC gene modulates the beta-catenin-Tcf pathway. The major player in this pathway is the beta-catenin protein encoded by the beta-catenin gene. A variety of different tumors, including colon, prostate, endometrial, and hepatocellular carcinomas, carry mutations in exon 3 of the beta-catenin gene. The aim of this study was to determine the role of the beta-catenin gene in the genesis of exocrine and endocrine tumors of the pancreas.

METHODS

78 ductal pancreatic adenocarcinomas, 14 ductal pancreatic cancer cell lines, and 33 endocrine pancreatic tumors were evaluated for mutations in exon 3 of the beta-catenin gene by single-strand conformation polymorphism analysis and direct DNA sequencing. In addition, 40 ductal pancreatic adenocarcinomas were analyzed for intracellular beta-catenin accumulation by immunohistochemistry, indicating alterations of the beta-catenin gene.

RESULTS

Neither the 111 exocrine and endocrine pancreatic tumors nor the 14 pancreatic cancer cell lines carried mutations in exon 3 of the beta-catenin gene. Intracellular beta-catenin accumulation was not identified in any of the 40 pancreatic adenocarcinomas.

CONCLUSION

These data suggest that the beta-catenin gene as the major player of the beta-catenin-Tcf pathway does not play an important role in the genesis of pancreatic tumors.

A transient, neuron-wide form of CREB-mediated long-term facilitation can be stabilized at specific synapses by local protein synthesis

In a culture system where a bifurcated Aplysia sensory neuron makes synapses with two motor neurons, repeated application of serotonin (5-HT) to one synapse produces a CREB-mediated, synapse-specific, long-term facilitation, which can be captured at the opposite synapse by a single pulse of 5-HT. Repeated pulses of 5-HT applied to the cell body of the sensory neuron produce a CREB-dependent, cell-wide facilitation, which, unlike synapse-specific facilitation, is not associated with growth and does not persist beyond 48 hr. Persistent facilitation and synapse-specific growth can be induced by a single pulse of 5-HT applied to a peripheral synapse. Thus, the short-term process initiated by a single pulse of 5-HT serves not only to produce transient facilitation, but also to mark and stabilize any synapse of the neuron for long-term facilitation by means of a covalent mark and rapamycin-sensitive local protein synthesis.

Impact of gene flow from cultivated beet on genetic diversity of wild sea beet populations

Gene flow and introgression from cultivated plants may have important consequences for the conservation of wild plant populations. Cultivated beets (sugar beet, red beet and Swiss chard: Beta vulgaris ssp. vulgaris) are of particular concern because they are cross-compatible with the wild taxon, sea beet (B.vs. ssp. maritima). Cultivated beet seed production areas are sometimes adjacent to sea beet populations; the numbers of flowering individuals in the former typically outnumber those in the populations of the latter. In such situations, gene flow from cultivated beets has the potential to alter the genetic composition of the nearby wild populations. In this study we measured isozyme allele frequencies of 11 polymorphic loci in 26 accessions of cultivated beet, in 20 sea beet accessions growing near a cultivated beet seed production region in northeastern Italy, and 19 wild beet accessions growing far from seed production areas. We found one allele that is specific to sugar beet, relative to other cultivated types, and a second that has a much higher frequency in Swiss chard and red beet than in sugar beet. Both alleles are typically rare in sea beet populations that are distant from seed production areas, but both are common in those that are near the Italian cultivated beet seed production region, supporting the contention that gene flow from the crop to the wild species can be substantial when both grow in proximity. Interestingly, the introgressed populations have higher genetic diversity than those that are isolated from the crop. The crop-to-wild gene flow rates are unknown, as are the fitness consequences of such alleles in the wild. Thus, we are unable to assess the long-term impact of such introgression. However, it is clear that gene flow from a crop to a wild taxon does not necessarily result in a decrease in the genetic diversity of the native plant.

Malignant fibrous histiocytoma of the pancreas: a case report with genetic analysis

BACKGROUND

Malignant fibrous histiocytoma (MFH) is the most common type of soft tissue sarcoma in adults; it occurs frequently in the extremities, the trunk, or retroperitoneal tissues. MFH rarely is detected in digestive organs, such as the liver or stomach.

METHODS

The authors report a patient with MFH of the pancreas who was treated with surgery alone. The tumor was studied for genetic alterations in the p53, p16ink4a, and DPC4 tumor suppressor genes as well as the K-ras oncogene by immunohistochemistry, single strand conformation variant (SSCV) analysis, and direct DNA sequencing.

RESULTS

The authors believe that this is the 13th report of primary pancreatic MFH in the world literature and the first genetic analysis of this rare tumor. The patient is alive with no evidence of recurrence 34 months after surgery. Immunohistochemistry revealed no abnormal accumulation of the p53 protein and normal nuclear p16 expression. Mutation analysis of the p53, p16, DPC4, and K-ras genes showed only a polymorphism at codon 72 of the p53 gene and no mutations in any of the genes.

CONCLUSIONS

Genotypically, MFH of the pancreas is clearly different from other malignant pancreatic tumors, which further supports the hypothesis that this tumor is a rare but distinct entity.

Higher frequency of DPC4/Smad4 alterations in pancreatic cancer cell lines than in primary pancreatic adenocarcinomas

The tumor suppressor gene DPC4/Smad4 at 18q21.1 is inactive in about 50% of pancreatic carcinoma xenografts and cell lines. However, the role of DPC4 in the multistep carcinogenesis of primary pancreatic adenocarcinomas remains uncertain. Therefore, we examined 45 primary human pancreatic adenocarcinomas and 12 pancreatic cancer cell lines for DPC4 alterations by single-strand conformational variant (SSCV) analysis and a PCR-based deletion assay. DPC4 was inactivated by either homozygous deletion or point mutation in 6 of 12 cell lines (50%). None of the primary pancreatic carcinomas carried a DPC4 mutation, although 66% revealed LOH of 18q21 sequences. These findings suggest that inactivation of DPC4 occurs more frequently in tumor-derived cell lines than in primary pancreatic adenocarcinomas. In addition, another, yet unidentified, tumor suppressor gene(s) may be linked with the frequent LOH of 18q21 in primary pancreatic adenocarcinomas.

Mutations of the DPC4/Smad4 gene in neuroendocrine pancreatic tumors

Tumors of the endocrine pancreas are extremely rare, and molecular mechanisms leading to their development are not well understood. A candidate tumor suppressor gene, DPC4, located at 18q21, has recently been shown to be inactivated in half of pancreatic adenocarcinoma xenografts. The close anatomical relationship of the exocrine and endocrine pancreas prompted us to determine the role of DPC4 in the tumorigenesis of 25 pancreatic islet cell tumors (11 insulinomas, nine non-functioning endocrine carcinomas, three gastrinomas, two vipomas). A mutation screening of the highly conserved COOH-terminal domain of DPC4 (exons 8-11) was performed by single-strand conformational variant (SSCP) analysis and a PCR-based deletion assay. Five of nine (55%) non-functioning endocrine pancreatic carcinomas revealed either point mutations, small intragenic deletions or homozygous deletion of DPC4 sequences compared to none of the insulinomas, gastrinomas or vipomas. These results suggest that DPC4 is an important target gene promoting tumorigenesis of non-functioning neuroendocrine pancreatic carcinomas.

Mechanisms for generating the autonomous cAMP-dependent protein kinase required for long-term facilitation in Aplysia

The formation of a persistently active cAMP-dependent protein kinase (PKA) is critical for establishing long-term synaptic facilitation (LTF) in Aplysia. The injection of bovine catalytic (C) subunits into sensory neurons is sufficient to produce protein synthesis-dependent LTF. Early in the LTF induced by serotonin (5-HT), an autonomous PKA is generated through the ubiquitin-proteasome-mediated proteolysis of regulatory (R) subunits. The degradation of R occurs during an early time window and appears to be a key function of proteasomes in LTF. Lactacystin, a specific proteasome inhibitor, blocks the facilitation induced by 5-HT, and this block is rescued by injecting C subunits. R is degraded through an allosteric mechanism requiring an elevation of cAMP coincident with the induction of a ubiquitin carboxy-terminal hydrolase.

[Germline mutations in the MEN1 gene: basis for predictive genetic screening and clinical management of multiple endocrine neoplasia type 1 (MEN1) families]

BACKGROUND AND OBJECTIVE

Mutations in the MEN 1 gene were recently discovered as the causative genetic defect of the autosomal dominantly inherited multiple endocrine neoplasia type 1. It was the aim of this study to evaluate the spectrum of MEN 1 mutations in our own series of patients in order to obtain a basis for predictive family screening.

PATIENTS AND METHODS

Genomic DNA from peripheral blood of 21 patients with MEN 1, members of 14 non-related MEN 1 families, was examined for MEN 1 germ-line mutations by means of single-strand conformation variant analysis (SSCP) and direct DNA sequencing. In addition, blood from 20 asymptomatic family members of five families was tested for its predictive value.

RESULTS

Eleven different heterozygotic germ-line mutations, among them eight frameshift, two missense and one nonsense mutations, were identified. In four of the 20 asymptomatic members from five MEN 1 families who had been tested after appropriate genetic counselling, the MEN 1 mutation characteristic for the particular family was found. Clinical screening programme in three mutation carriers revealed abnormal findings in all three: one primary hyperparathyroidism, one prolactinoma and one nonfunctioning pancreatic tumour each. The 16 family members without MEN 1 mutation were spared further unnecessary screening investigations.

CONCLUSION

Although the function of the MEN 1 gene is not yet known, molecular genetic tests provide a basis for genetic counselling, predictive genetic screening and clinical management of MEN 1 families.