The epigenetic EZH2/H3K27me3 axis modulates lactotroph tumor cell proliferation.

Interest in epigenetics has gained substantial momentum as a result of their identified role in the regulation of tumor progression as well as their ability to pharmacologically target genes. Pituitary neuroendocrine tumors (PitNETs) tend to be inactivated via epigenetic modification, and although emerging evidence has suggested a role for epigenetic factors in PitNET tumorigenesis, the degree to which these factors may be targeted by new therapeutic strategies still remains poorly understood. The objective of the present study was to examine the participation of the EZH2/H3K27me3 axis in the proliferation of lactotroph tumor cells. We demonstrated that the levels of EZH2 and H3K27me3 were increased in murine experimental prolactin (PRL) tumors with respect to a control pituitary, in contrast with the low p21 mRNA levels encountered, with an H3K27me3 enrichment being observed in its promoter region in a GH3 tumor cell. Furthermore, specific EZH2/H3K27me3 axis inhibition blocked the proliferation of primary tumor cell culture and GH3 cells, thereby making it an attractive therapeutic target for PRL PitNETs.

Impact of 10-Day Fulbright Specialist Program and Project Pink Blue Education Sessions on Medical Oncology Knowledge Among Physicians Who Treat Cancer in Nigeria.

Despite an estimated population of over 201 million and over 115,950 yearly diagnosed new cases of cancer, Nigeria does not have dedicated medical oncologists. Most oncology care is delivered through surgical and clinical oncologists, who are trained in both radiation and medical oncology and they number fewer than 50 in the country. With a limited number of oncology professionals, cancer patients in Nigeria experience poor health outcomes, with an estimated cancer mortality rate of 75,000 deaths per year. Participants from 15 Nigerian states were selected to attend the medical oncology training. Through the support of Fulbright Specialist Program and Project PINK BLUE, two of the authors delivered 10 days of lectures based on ASCO, ESMO, and NCCN guidelines. Mean scores of both the pre- and post-course tests as well as a 1-year follow-up test were compared using GraphPad Prism 7.0a by paired t-tests. Forty-four clinical oncologists were selected for participation. Twenty-five (57%) completed the pre- and post-course tests. Of the 25 that completed both tests, percentage of correct answers increased from 45 to 59% (2-sided p-value < 0.0001). Improvements were seen in attending doctors 45 to 59% (p = 0.0046) and resident doctors 45 to 59% (0.0007). Eleven doctors responded to the 1-year follow-up test. Although not statistically significant, a numerical pattern for the benefits was maintained 1 year after the program (45% pre-course versus 52% post-course correct answers, Fisher's exact, p = 0.4185). In the short term, the training improved medical oncology knowledge in Nigeria, regardless of the participant's carrier stage. Long-term benefits were not sustained in a small sample of participants, and continuing education strategies are necessary. Similar models may be employed across Africa.

OSIRIS-REx Contamination Control Strategy and Implementation.

OSIRIS-REx will return pristine samples of carbonaceous asteroid Bennu. This article describes how pristine was defined based on expectations of Bennu and on a realistic understanding of what is achievable with a constrained schedule and budget, and how that definition flowed to requirements and implementation. To return a pristine sample, the OSIRIS-REx spacecraft sampling hardware was maintained at level 100 A/2 and <180 ng/cm2 of amino acids and hydrazine on the sampler head through precision cleaning, control of materials, and vigilance. Contamination is further characterized via witness material exposed to the spacecraft assembly and testing environment as well as in space. This characterization provided knowledge of the expected background and will be used in conjunction with archived spacecraft components for comparison with the samples when they are delivered to Earth for analysis. Most of all, the cleanliness of the OSIRIS-REx spacecraft was achieved through communication among scientists, engineers, managers, and technicians.

Magnetic resonance diffusion tensor imaging for the pedunculopontine nucleus: proof of concept and histological correlation.

The pedunculopontine nucleus (PPN) has been proposed as target for deep brain stimulation (DBS) in patients with postural instability and gait disorders due to its involvement in muscle tonus adjustments and control of locomotion. However, it is a deep-seated brainstem nucleus without clear imaging or electrophysiological markers. Some studies suggested that diffusion tensor imaging (DTI) may help guiding electrode placement in the PPN by showing the surrounding fiber bundles, but none have provided a direct histological correlation. We investigated DTI fractional anisotropy (FA) maps from in vivo and in situ post-mortem magnetic resonance images (MRI) compared to histological evaluations for improving PPN targeting in humans. A post-mortem brain was scanned in a clinical 3T MR system in situ. Thereafter, the brain was processed with a special method ideally suited for cytoarchitectonic analyses. Also, nine volunteers had in vivo brain scanning using the same MRI protocol. Images from volunteers were compared to those obtained in the post-mortem study. FA values of the volunteers were obtained from PPN, inferior colliculus, cerebellar crossing fibers and medial lemniscus using histological data and atlas information. FA values in the PPN were significantly lower than in the surrounding white matter region and higher than in areas with predominantly gray matter. In Nissl-stained histologic sections, the PPN extended for more than 10 mm in the rostro-caudal axis being closely attached to the lateral parabrachial nucleus. Our DTI analyses and the spatial correlation with histological findings proposed a location for PPN that matched the position assigned to this nucleus in the literature. Coregistration of neuroimaging and cytoarchitectonic features can add value to help establishing functional architectonics of the PPN and facilitate neurosurgical targeting of this extended nucleus.

PCSK1 Variants and Human Obesity.

PCSK1, encoding prohormone convertase 1/3 (PC1/3), was one of the first genes linked to monogenic early-onset obesity. PC1/3 is a protease involved in the biosynthetic processing of a variety of neuropeptides and prohormones in endocrine tissues. PC1/3 activity is essential for the activating cleavage of many peptide hormone precursors implicated in the regulation of food ingestion, glucose homeostasis, and energy homeostasis, for example, proopiomelanocortin, proinsulin, proglucagon, and proghrelin. A large number of genome-wide association studies in a variety of different populations have now firmly established a link between three PCSK1 polymorphisms frequent in the population and increased risk of obesity. Human subjects with PC1/3 deficiency, a rare autosomal-recessive disorder caused by the presence of loss-of-function mutations in both alleles, are obese and display a complex set of endocrinopathies. Increasing numbers of genetic diagnoses of infants with persistent diarrhea has recently led to the finding of many novel PCSK1 mutations. PCSK1-deficient infants experience severe intestinal malabsorption during the first years of life, requiring controlled nutrition; these children then become hyperphagic, with associated obesity. The biochemical characterization of novel loss-of-function PCSK1 mutations has resulted in the discovery of new pathological mechanisms affecting the cell biology of the endocrine cell beyond simple loss of enzyme activity, for example, dominant-negative effects of certain mutants on wild-type PC1/3 protein, and activation of the cellular unfolded protein response by endoplasmic reticulum-retained mutants. A better understanding of these molecular and cellular pathologies may illuminate possible treatments for the complex endocrinopathy of PCSK1 deficiency, including obesity.

Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars.

The Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of Mars at Gale Crater. Central to this task is the development of an inventory of any organic molecules present to elucidate processes associated with their origin, diagenesis, concentration, and long-term preservation. This will guide the future search for biosignatures. Here we report the definitive identification of chlorobenzene (150-300 parts per billion by weight (ppbw)) and C2 to C4 dichloroalkanes (up to 70 ppbw) with the SAM gas chromatograph mass spectrometer (GCMS) and detection of chlorobenzene in the direct evolved gas analysis (EGA) mode, in multiple portions of the fines from the Cumberland drill hole in the Sheepbed mudstone at Yellowknife Bay. When combined with GCMS and EGA data from multiple scooped and drilled samples, blank runs, and supporting laboratory analog studies, the elevated levels of chlorobenzene and the dichloroalkanes cannot be solely explained by instrument background sources known to be present in SAM. We conclude that these chlorinated hydrocarbons are the reaction products of Martian chlorine and organic carbon derived from Martian sources (e.g., igneous, hydrothermal, atmospheric, or biological) or exogenous sources such as meteorites, comets, or interplanetary dust particles. KEY POINTS: First in situ evidence of nonterrestrial organics in Martian surface sediments Chlorinated hydrocarbons identified in the Sheepbed mudstone by SAM Organics preserved in sample exposed to ionizing radiation and oxidative condition.

Carbohydrate-based polyesters made from bicyclic acetalized galactaric acid.

The dimethyl ester of 2,3:4,5-di-O-methylene-galactaric acid (Galx) was made to react in the melt with 1,n-alkanediols HO(CH(2))(n)OH containing even numbers of methylenes (n from 6 to 12) to produce linear polycyclic polyesters. Two sets of poly(alkylene 2,3:4,5-di-O-methylene-galactarate) polyesters (PE-nGalx) with weight-average molecular weights in the ∼ 5000-10000 and ∼ 35000-45000 ranges were obtained using TBT and DBTO catalysts, respectively. For comparative purposes a set of poly(alkylene adipate) polyesters (PE-nAd) was also synthesized with molecular weights in the higher range using a similar procedure. The thermal stability of PE-nGalx was greater than that of PE-nAd although it notably decayed as molecular weight decreased. The replacement of Ad by Galx in the polyesters caused increases in T(g) of up to 70 °C, and almost doubled the tensile mechanical parameters. All PE-nGalx were semicrystalline but only those made from 1,12-dodecanediol were able to crystallize from the melt with a crystallization rate that diminished as the molecular weight increased. In general, the galactarate containing polyesters displayed higher solubility and wettability than polyadipates, they hydrolyzed faster and exhibited comparable sensitivity to the action of lipases.

Synthetic polymers from readily available monosaccharides.

The low degradability of petroleum-based polymers and the massive use of these materials constitute a serious problem because of the environmental pollution that they can cause. Thus, sustained efforts have been extensively devoted to produce new polymers based on natural renewing resources and with higher degradability. Of the different natural sources, carbohydrates stand out as highly convenient raw materials because they are inexpensive, readily available, and provide great stereochemical diversity. New polymers, analogous to the more accredited technical polymers, but based on chiral monomers, have been synthesized from natural and available sugars. This chapter describes the potential of sugar-based monomers as precursors to a wide variety of macromolecular materials.

Allo-SCT conditioning for myelodysplastic syndrome and acute myeloid leukemia with clofarabine, cytarabine and ATG.

The application of myeloablative Allo-SCT is limited by its associated morbidity and mortality. Reduced-intensity conditioning regimens attempt to diminish these, but are associated with a higher risk of disease relapse. Given the evidence of activity of clofarabine and cytarabine in myelodysplastic syndrome/acute myeloid leukemia (MDS/AML), we explored a novel reduced-intensity conditioning regimen based on this backbone. Patients received clofarabine 40 mg/m(2) i.v. on days -6 to -2, cytarabine 1 g/m(2) i.v. on days -6 to -2 and anti-thymocyte globulin (ATG) 1 mg/kg on day -4 and 2.5 mg/kg x 2 days on days -3 and -2. Seven patients were enrolled. Their median age was 54 years; three were with MDS and four with AML. The median duration of neutropenia was 14 days and that of thrombocytopenia was 22 days. Toxicities included hand-foot syndrome (57% grade 2), elevated alanine aminotransferase (ALT) (57% grade 3), elevated aspartate aminotransferase (AST) (86% grade 3) and hyperbilirubinemia (29% grade 3-5). No acute GVHD was observed. Enrollment to the trial was halted after three of the first seven patients expired on days +15, +26 and +32. Three of the four surviving patients have relapsed with a median TTP of 152 days. This regimen was not sufficiently immunosuppressive to ensure engraftment, and was associated with substantial morbidity and mortality.

No effect of 50 Hz 2.45 mT magnetic field on the potency of cisplatin, mitomycin C, and methotrexate in S. cerevisiae.

Drug resistance is an obstacle for chemotherapy success. Because of this, this work aims to improve the cell killing effect of antineoplastic drugs by magnetic field (MF) co-exposure. S. cerevisiae cells were exposed to 2.45 mT, sinusoidal 50 Hz MF, during 48 h, and the drugs cisplatin (cisPt), mitomycin C (MMC), or methotrexate (MTX); 100 and 1,000 microg/ml. Survival was assayed by the drop test. The results showed that MF exposures do not induce alterations in the potency of cisPt, MMC, and MTX on these cells in relation to untreated controls. In addition, a strong correlation between temperature and potency of cisPt was found, which contribute to the establishment of the importance of an exhaustive control of temperature in experiments carried out with temperature sensitive antineoplastic agents in co-exposure with MF; avoiding differences between MF-exposed samples and unexposed controls and contributing to the performance of experiments under well-defined and controlled conditions.

Rejection and steroid dependence: unique risk factors in the development of pediatric posttransplant de novo autoimmune hepatitis.

Posttransplant de novo autoimmune hepatitis (d-AIH) is increasingly described as a long-term complication after pediatric liver transplantation (LT). d-AIH is characterized by graft dysfunction, the development of autoimmune antibodies and histologic evidence of hepatitis in liver transplant recipients without previous history of autoimmune liver disease. This study is a matched case-control, univariate analysis aimed at identifying risk factors for the development of d-AIH and evaluating response to treatment. From 1984 to 2003, 619 children received 788 LTs at a single center. Forty-one patients developed d-AIH and were matched with controls for year of LT, age at time of LT and diagnosis. The following variables were insignificant in the development of d-AIH: age, gender, race, initial diagnosis, ischemia time, graft type, Epstein-Barr virus and cytomegalovirus status, HLA typing and primary immunosuppression. Compared to controls, d-AIH patients were less likely to be on monotherapy immunosuppression or weaned off prednisone at the time of diagnosis. The d-AIH group relative to the controls had statistically significant greater numbers of rejection episodes. d-AIH was treated with prednisone and/or MMF in 39 of 41 patients and lead to significant improvements in liver function tests. Thirty-nine patients are alive at a mean of 4.0 years follow-up after diagnosis. Three have required retransplantation.

Artifact simulating subarachnoid and intraventricular hemorrhage on single-shot, fast spin-echo fluid-attenuated inversion recovery images caused by head movement: A trap for the unwary.

BACKGROUND AND PURPOSE: Single-shot, fast spin-echo, fluid attenuated inversion recovery (SS-FSE-FLAIR) images are frequently used to detect disease in the brain and subarachnoid space in confused or uncooperative patients who may move during the examination. In some of these patients, high signal intensity areas are seen on good-quality images in the subarachnoid space and ventricular system in locations not associated with high CSF flow. These artifacts may simulate hemorrhage or leptomeningeal disease. The purpose of this article was to determine the cause of these artifacts, describe ways to recognize them, and find methods to reduce or eliminate them. METHODS: Healthy volunteers were studied on 6 occasions with conventional multisection FSE-FLAIR images and SS-FSE-FLAIR images while at rest and while nodding and rotating their heads at different speeds. In addition, SS-FSE-FLAIR images with different section widths of the initial inverting pulse and a non-section-selective initial inversion pulse were performed with the subjects moving their heads in the same way. The scans of 30 successive patients with acute neurologic syndromes who had been studied with SS-FSE-FLAIR sequences were reviewed for evidence of high signal intensity in the CSF in regions not associated with high CSF flow. RESULTS: Each of the volunteers showed areas of increased signal intensity in CSF at sites apart from those associated with rapid pulsatile CSF flow on SS-FSE-FLAIR images acquired during head motion. The images were otherwise virtually free of motion artifact. The use of a wider initial inversion pulse section and a non-section-selected initial inversion pulse reduced the extent of these artifacts. Nineteen of the 30 patients showed areas of high signal intensity in the CSF in regions not associated with highly pulsatile CSF flow. Six of these patients had negative lumbar punctures for blood and xanthochromia and normal CSF protein levels. CONCLUSION: High signal intensity artifacts may be seen in CSF as a result of head movement on otherwise artifact-free images when imaging uncooperative patients with SS-FSE-FLAIR sequences. These artifacts have a different mechanism and distribution from those caused by CSF pulsation and may simulate subarachnoid and intraventricular hemorrhage. Artifact recognition is aided by signs of patient motion during the examination. The artifacts can be reduced by use of increased section width and non-section-selective initial inversion pulses. Recognition of these artifacts is important, because the circumstances in which the SS-FSE-FLAIR sequence is used and the particular properties of the sequence may conspire to produce a trap for the unwary.

Patterns of cerebral activation during lexical and phonological reading in Portuguese

According to the concepts of cognitive neuropsychology, there are two principal routes of reading processing: a lexical route, in which global reading of words occurs and a phonological route, responsible for the conversion of the graphemes into their respective phonemes. In the present study, functional magnetic resonance imaging (fMRI) was used to investigate the patterns of cerebral activation in lexical and phonological reading by 13 healthy women with a formal educational level greater than 11 years. Participants were submitted to a silent reading task containing three types of stimuli: real words (irregular and foreign words), nonwords and illegitimate graphic stimuli. An increased number of activated voxels were identified by fMRI in the word reading (lexical processing) than in the nonword reading (phonological processing) task. In word reading, activation was greater than for nonwords in the following areas: superior, middle and inferior frontal gyri, and bilateral superior temporal gyrus, right cerebellum and the left precentral gyrus, as indicated by fMRI. In the reading of nonwords, the activation was predominant in the right cerebellum and in the left superior temporal gyrus. The results of the present study suggest the existence of differences in the patterns of cerebral activation during lexical and phonological reading, with greater involvement of the right hemisphere in reading words than nonwords.

Patterns of cerebral activation during lexical and phonological reading in Portuguese.

According to the concepts of cognitive neuropsychology, there are two principal routes of reading processing: a lexical route, in which global reading of words occurs and a phonological route, responsible for the conversion of the graphemes into their respective phonemes. In the present study, functional magnetic resonance imaging (fMRI) was used to investigate the patterns of cerebral activation in lexical and phonological reading by 13 healthy women with a formal educational level greater than 11 years. Participants were submitted to a silent reading task containing three types of stimuli: real words (irregular and foreign words), nonwords and illegitimate graphic stimuli. An increased number of activated voxels were identified by fMRI in the word reading (lexical processing) than in the nonword reading (phonological processing) task. In word reading, activation was greater than for nonwords in the following areas: superior, middle and inferior frontal gyri, and bilateral superior temporal gyrus, right cerebellum and the left precentral gyrus, as indicated by fMRI. In the reading of nonwords, the activation was predominant in the right cerebellum and in the left superior temporal gyrus. The results of the present study suggest the existence of differences in the patterns of cerebral activation during lexical and phonological reading, with greater involvement of the right hemisphere in reading words than nonwords.

Epitaxy and magnetic properties of surfactant-mediated growth of bcc cobalt.

High resolution core level photoemission spectroscopy, photoelectron diffraction, and x-ray magnetic circular dicroism (XMCD) have been used to characterize the structural and magnetic properties of bcc-cobalt films grown on GaAs(110) substrates by using Sb as a surfactant. We have unambiguously disentangled the surfactant role played by the Sb which improves the crystallinity and reduces the lattice distortion of the metallic films as well as changes the interdiffusion process at the interface compared to the Co/GaAs(110) system. As a consequence of these combined effects, an improvement on the magnetic response of the grown Co thin films has been observed by XMCD measurements.

Synthesis and secondary structure of oligo(alpha-isobutyl beta,L-aspartate)s.

The oligo(beta-peptide)s, hexa(alpha-isobutyl beta,L-aspartate) (Hex-AIBLA) and octa(alpha-isobutyl beta,L-aspartate) (Oct-AIBLA), were synthesized in solution by using standard coupling methods. Powder x-ray diffraction showed that the octamer crystallized in the two helical crystal forms known to exist in the homologous poly(beta-peptide), whereas the hexamer seemed to adopt an extended conformation. Both CD and 1H-NMR spectra of Oct-AIBLA in MeOH revealed the presence of a regularly folded conformation in this solvent, presumably the 3(14) helix. The helix-to-coil transition of Oct-AIBLA was observed to take place upon heating in both MeOH and CHCl3, in the second case associated with a not-well-defined aggregation-disaggregation process. The spectroscopic evidence obtained on the presence of folded structures in Hex-AIBLA were much weaker than for the octamer.