132 research outputs found
Dynamical Bonding Driving Mixed Valency in a Metal Boride
Samarium hexaboride is an anomaly, having many exotic and seemingly mutually
incompatible properties. It was proposed to be a mixed-valent semiconductor,
and later - a topological Kondo insulator, and yet has a Fermi surface despite
being an insulator. We propose a new and unified understanding of SmB
centered on the hitherto unrecognized dynamical bonding effect: the coexistence
of two Sm-B bonding modes within SmB, corresponding to different oxidation
states of the Sm. The mixed valency arises in SmB from thermal population
of these distinct minima enabled by motion of B. Our model simultaneously
explains the thermal valence fluctuations, appearance of magnetic Fermi
surface, excess entropy at low temperatures, pressure-induced phase
transitions, and related features in Raman spectra and their unexpected
dependence on temperature and boron isotope
FRECUENCIA EN EL USO DE MEDICAMENTOS POR LAS GESTANTES QUE ACUDEN AL C.S. CIUDAD NUEVA EN EL AÑO 2000
El presente trabajo de Investigación determina la Frecuencia en el Uso de Medicamentos bajo Prescripción por Gestantes que acudieron al Centro de Salud de Ciudad Nueva durante el año 2000. Es una Investigación Descriptiva con un Diseño No experimental Transversal, y se realizó en una población de 475 gestantes, de las cuales se tomó como muestra representativa 190 pacientes, que represente el 40% del universo.
El tratamiento con medicamentos en gestantes presenta características particulares, ya que son dos organismos a los que puede afectar la acción de los medicamentos con distinta sensibilidad.
La administración de medicamentos supone un riesgo para la embarazada y el embrión o el feto. Sin embargo, otro principio importante es que no debe omitirse un tratamiento farmacológico indicado desde el punto de vista médico a la gestante.
El paso de medicamentos desde la madre al embrión o al feto a través de la placenta, podría originar en ciertos casos una afección teratogénica para este último. Es muy importante tener en cuenta el paso de éstos a través de la placenta para evitar su llegada o el uso innecesario, capaces de producir efectos adversos.
En nuestro estudio se encontró que el 57.90% de gestantes tomaron por lo menos un medicamento, valor mayor al encontrado por Whittle en Estados Unidos el año 85 y por Rubin en 1986, menor a los valores encontrados por la International Journal Of Gynecology Obstetrics los 80 y por De Jong Van den Berg, los años 1987-88 ere Holanda.
Se encontró que el 31.58% de gestantes que toman medicamentos son convivientes, el 52.62% del total de gestantes, que acuden al C.S. son convivientes.
Los medicamentos prescritos más tomados por las gestantes son el sulfato ferroso y Amoxicilina en tabletas, con 22.22% y 21.11% respectivamente
Parent-reported health care expenditures associated with autism spectrum disorders in Heilongjiang province, China
<p>Abstract</p> <p>Background</p> <p>The aim of this study was to determine the health expenses incurred by families with children with autism spectrum disorder (ASD) and those expenses' relation to total household income and expenditures.</p> <p>Methods</p> <p>In this cross-sectional study, health care expenditure data were collected through face-to-face interviews. Expenses included annual costs for clinic visits, medication, behavioral therapy, transportation, and accommodations. Health care costs as a percentage of total household income and expenditures were also determined. The participants included 290 families with ASD children who were treated at the Children Development and Behavior Research Center, Harbin Medical University, China.</p> <p>Results</p> <p>Families with ASD children from urban and rural areas had higher per-capita household expenditures by 60.8% and 74.7%, respectively, compared with provincial statistics for 2007. Behavioral therapy accounted for the largest proportion of health expenses (54.3%) for ASD children. In 19.9% of urban and 38.2% of rural families, health care costs exceeded the total annual household income. Most families (89.3% of urban families; 88.1% of rural families) in that province reported higher health care expenditures than the provincial household average.</p> <p>Conclusion</p> <p>For families with ASD children, the economic burden of health care is substantially higher than the provincial average.</p
Cross-linguistic adaptations of The Comprehensive Aphasia Test: Challenges and solutions
Comparative research on aphasia and aphasia rehabilitation is challenged by the lack of comparable assessment tools across different languages. In English, a large array of tools is available, while in most other languages, the selection is more limited. Importantly, assessment tools are often simple translations and do not take into consideration specific linguistic and psycholinguistic parameters of the target languages. As a first step in meeting the needs for comparable assessment tools, the Comprehensive Aphasia Test is currently being adapted into a number of languages spoken in Europe. In this article, some key challenges encountered in the adaptation process and the solutions to ensure that the resulting assessment tools are linguistically and culturally equivalent, are proposed. Specifically, we focus on challenges and solutions related to the use of imageability, frequency, word length, spelling-to-sound regularity and sentence length and complexity as underlying properties in the selection of the testing material
The Growth and Tumor Suppressors NORE1A and RASSF1A Are Targets for Calpain-Mediated Proteolysis
Background: NORE1A and RASSF1A are growth and tumour suppressors inactivated in a variety of cancers. Methylation of NORE1A and RASSF1A promoters is the predominant mechanism for downregulation of these proteins; however, other mechanisms are likely to exist. Methodology/Principal Findings: Here we describe a proteolysis of NORE1A and RASSF1A by calpains as alternative mechanism of their downregulation. Extracts of H358 cell line, a human bronchoalveolar carcinoma, and H460, a large cell carcinoma, were capable of proteolysis of NORE1A protein in the calpain-dependent manner. Likewise, RASSF1A tumor suppressor was proteolyzed by the H358 cell extract. Addition of calpain inhibitor to H358 and H460 cells growing in tissue culture resulted in re-expression of endogenous NORE1A. A survey of 10 human lung tumours revealed that three of them contain an activity capable of inducing NORE1A degradation. Conclusions/Significance: Thus, degradation by calpains is a novel mechanism for downregulation of NORE1A and RASSF1A proteins and might be the mechanism allowing cancer cells to escape growth suppression
Whole Exome Sequencing of Patients with Steroid-Resistant Nephrotic Syndrome
BACKGROUND AND OBJECTIVES: Steroid-resistant nephrotic syndrome overwhelmingly progresses to ESRD. More than 30 monogenic genes have been identified to cause steroid-resistant nephrotic syndrome. We previously detected causative mutations using targeted panel sequencing in 30% of patients with steroid-resistant nephrotic syndrome. Panel sequencing has a number of limitations when compared with whole exome sequencing. We employed whole exome sequencing to detect monogenic causes of steroid-resistant nephrotic syndrome in an international cohort of 300 families.
DESIGN, SETTING, PARTIIPANTS AND MEASUREMENTS: Three hundred thirty-five individuals with steroid-resistant nephrotic syndrome from 300 families were recruited from April of 1998 to June of 2016. Age of onset was restricted to <25 years of age. Exome data were evaluated for 33 known monogenic steroid-resistant nephrotic syndrome genes.
RESULTS: In 74 of 300 families (25%), we identified a causative mutation in one of 20 genes known to cause steroid-resistant nephrotic syndrome. In 11 families (3.7%), we detected a mutation in a gene that causes a phenocopy of steroid-resistant nephrotic syndrome. This is consistent with our previously published identification of mutations using a panel approach. We detected a causative mutation in a known steroid-resistant nephrotic syndrome gene in 38% of consanguineous families and in 13% of nonconsanguineous families, and 48% of children with congenital nephrotic syndrome. A total of 68 different mutations were detected in 20 of 33 steroid-resistant nephrotic syndrome genes. Fifteen of these mutations were novel. NPHS1, PLCE1, NPHS2, and SMARCAL1 were the most common genes in which we detected a mutation. In another 28% of families, we detected mutations in one or more candidate genes for steroid-resistant nephrotic syndrome.
CONCLUSIONS: Whole exome sequencing is a sensitive approach toward diagnosis of monogenic causes of steroid-resistant nephrotic syndrome. A molecular genetic diagnosis of steroid-resistant nephrotic syndrome may have important consequences for the management of treatment and kidney transplantation in steroid-resistant nephrotic syndrome
Predicting response and survival in chemotherapy-treated triple-negative breast cancer
In this study, we evaluated the ability of gene expression profiles to predict chemotherapy response and survival in triple-negative breast cancer (TNBC). Gene expression and clinical-pathological data were evaluated in five independent cohorts, including three randomised clinical trials for a total of 1055 patients with TNBC, basal-like disease (BLBC) or both. Previously defined intrinsic molecular subtype and a proliferation signature were determined and tested. Each signature was tested using multivariable logistic regression models (for pCR (pathological complete response)) and Cox models (for survival). Within TNBC, interactions between each signature and the basal-like subtype (vs other subtypes) for predicting either pCR or survival were investigated. Within TNBC, all intrinsic subtypes were identified but BLBC predominated (55-81%). Significant associations between genomic signatures and response and survival after chemotherapy were only identified within BLBC and not within TNBC as a whole. In particular, high expression of a previously identified proliferation signature, or low expression of the luminal A signature, was found independently associated with pCR and improved survival following chemotherapy across different cohorts. Significant interaction tests were only obtained between each signature and the BLBC subtype for prediction of chemotherapy response or survival. The proliferation signature predicts response and improved survival after chemotherapy, but only within BLBC. This highlights the clinical implications of TNBC heterogeneity, and suggests that future clinical trials focused on this phenotypic subtype should consider stratifying patients as having BLBC or not
P73 regulates cisplatin-induced apoptosis in ovarian cancer cells via a calcium/calpain-dependent mechanism
P73 is important in drug-induced apoptosis in some cancer cells, yet its role in the regulation of chemosensitivity in ovarian cancer (OVCA) is poorly understood. Furthermore, if and how the deregulation of p73-mediated apoptosis confers resistance to cisplatin (CDDP) treatment is unclear. Here we demonstrate that TAp73α over-expression enhanced CDDP-induced PARP cleavage and apoptosis in both chemosensitive (OV2008 and A2780s) and their resistant counterparts (C13* and A2780cp) and another chemoresistant OVCA cells (Hey); in contrast, the effect of ΔNp73α over-expression was variable. P73α downregulation attenuated CDDP-induced PUMA and NOXA upregulation and apoptosis in OV2008 cells. CDDP decreased p73α steady-state protein levels in OV2008, but not in C13*, although the mRNA expression was identical. CDDP-induced p73α downregulation was mediated by a calpain-dependent pathway. CDDP induced calpain activation and enhanced its cytoplasmic interaction and co-localization with p73α in OV2008, but not C13* cells. CDDP increased the intracellular calcium concentration ([Ca2+]i) in OV2008 but not C13* whereas cyclopiazonic acid (CPA), a Ca2+-ATPase inhibitor, caused this response and calpain activation, p73α processing and apoptosis in both cell types. CDDP-induced [Ca2+]i increase in OV2008 cells was not effected by the elimination of extracellular Ca2+, but this was attenuated by the depletion of internal Ca2+ store, indicating that mobilization of intracellular Ca2+] stores was potentially involved. These findings demonstrate that p73α and its regulation by the Ca2+-mediated calpain pathway are involved in CDDP-induced apoptosis in OVCA cells and that dysregulation of Ca2+/calpain/p73 signaling may in part be the pathophysiology of CDDP resistance. Understanding the cellular and molecular mechanisms of chemoresistance will direct the development of effective strategies for the treatment of chemoresistant OVCA
SUMOylation by Pias1 Regulates the Activity of the Hedgehog Dependent Gli Transcription Factors
Hedgehog (Hh) signaling, a vital signaling pathway for the development and homeostasis of vertebrate tissues, is mediated by members of the Gli family of zinc finger transcription factors. Hh signaling increases the transcriptional activity of Gli proteins, at least in part, by inhibiting their proteolytic processing. Conversely, phosphorylation by cAMP-dependent protein kinase (PKA) inhibits Gli transcriptional activity by promoting their ubiquitination and proteolysis. Whether other post-translational modifications contribute to the regulation of Gli protein activity has been unclear.Here we provide evidence that all three Gli proteins are targets of small ubiquitin-related modifier (SUMO)-1 conjugation. Expression of SUMO-1 or the SUMO E3 ligase, Pias1, increased Gli transcriptional activity in cultured cells. Moreover, PKA activity reduced Gli protein SUMOylation. Strikingly, in the embryonic neural tube, the forced expression of Pias1 increased Gli activity and induced the ectopic expression of the Gli dependent gene Nkx2.2. Conversely, a point mutant of Pias1, that lacks ligase activity, blocked the endogenous expression of Nkx2.2.Together, these findings provide evidence that Pias1-dependent SUMOylation influences Gli protein activity and thereby identifies SUMOylation as a post-translational mechanism that regulates the hedgehog signaling pathway
Regulation of p73 activity by post-translational modifications
The transcription factor p73 is a member of the p53 family that can be expressed as at least 24 different isoforms with pro- or anti-apoptotic attributes. The TAp73 isoforms are expressed from an upstream promoter and are regarded as bona fide tumor suppressors; they can induce cell cycle arrest/apoptosis and protect against genomic instability. On the other hand, ΔNp73 isoforms lack the N-terminus transactivation domain; hence, cannot induce the expression of pro-apoptotic genes, but still can oligomerize with TAp73 or p53 to block their transcriptional activities. Therefore, the ratio of TAp73 isoforms to ΔNp73 isoforms is critical for the quality of the response to a genomic insult and needs to be delicately regulated at both transcriptional and post-translational level. In this review, we will summarize the current knowledge on the post-translational regulatory pathways involved to keep p73 protein under control. A comprehensive understanding of p73 post-translational modifications will be extremely useful for the development of new strategies for treating and preventing cancer
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