PKA Mediates Constitutive Activation of CFTR in Human Sweat Duct

The cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channels are constitutively activated in sweat ducts. Since phosphorylation-dependent and -independent mechanisms can activate CFTR, we sought to determine the actual mechanism responsible for constitutive activation of these channels in vivo. We show that the constitutively activated CFTR Cl− conductance (gCFTR) in the apical membrane is completely deactivated following α-toxin permeabilization of the basolateral membrane. We investigated whether such inhibition of gCFTR following permeabilization is due to the loss of cytoplasmic glutamate or due to dephosphorylation of CFTR by an endogenous phosphatase in the absence of kinase activity (due to the loss of kinase agonist cAMP, cGMP or GTP through α-toxin pores). In order to distinguish between these two possibilities, we examined the effect of inhibiting the endogenous phosphatase activity with okadaic acid (10−8 M) on the permeabilization-induced deactivation of gCFTR. We show that okadaic acid (1) inhibits an endogenous phosphatase responsible for dephosphorylating cAMP but not cGMP or G protein-activated CFTR and (2) prevents deactivation of CFTR following permeabilization of the basolateral membrane. These results indicate that distinctly different phosphatases may be responsible for dephosphorylating different kinase-specific sites on CFTR. We conclude that the phosphorylation by PKA alone appears to be primarily responsible for constitutive activation of gCFTR in vivo

Functional Copy-Number Alterations in Cancer

Understanding the molecular basis of cancer requires characterization of its genetic defects. DNA microarray technologies can provide detailed raw data about chromosomal aberrations in tumor samples. Computational analysis is needed (1) to deduce from raw array data actual amplification or deletion events for chromosomal fragments and (2) to distinguish causal chromosomal alterations from functionally neutral ones. We present a comprehensive computational approach, RAE, designed to robustly map chromosomal alterations in tumor samples and assess their functional importance in cancer. To demonstrate the methodology, we experimentally profile copy number changes in a clinically aggressive subtype of soft-tissue sarcoma, pleomorphic liposarcoma, and computationally derive a portrait of candidate oncogenic alterations and their target genes. Many affected genes are known to be involved in sarcomagenesis; others are novel, including mediators of adipocyte differentiation, and may include valuable therapeutic targets. Taken together, we present a statistically robust methodology applicable to high-resolution genomic data to assess the extent and function of copy-number alterations in cancer

Setores de cuidado à saúde e sua inter-relação na assistência domiciliar ao doente crônico Sectores de cuidado a la salud y su interrelación en la asistencia domiciliar al enfermo crónico Health care sectors and their interrelation in the context of nursing care of the chronic patient

Objetivou-se descrever a inter-relação e comunicação nos setores de cuidado à saúde sob a perspectiva de cuidadores familiares de adoecidos crônicos com doença incapacitante. Estudo qualitativo, descritivo e exploratório, realizado com 11 cuidadores familiares de pacientes adscritos em uma Estratégia de Saúde da Família localizada no município de Santa Maria, Rio Grande do Sul. Os cuidadores familiares foram indicados pela equipe de saúde da unidade. A coleta de dados ocorreu de julho a setembro de 2010 e desenvolveu-se com entrevistas narrativas, orientadas por eixos norteadores. Da análise de conteúdo temática surgiram categorias relacionadas à comunicação e às relações interpessoais entre profissionais, cuidadores familiares e doentes, além das interfaces entre os setores de cuidado à saúde. Há necessidade de uma comunicação efetiva entre os setores de cuidado, de maneira que atuem conjuntamente, permitindo troca de saberes que auxiliem no enfrentamento do processo de doença.<br>Se objetiva describir la interrelación y comunicación en los sectores de cuidado a la salud, bajo la perspectiva de cuidadores familiares de enfermos crónicos con enfermedad discapacitante. Estudio cualitativo, descriptivo y exploratorio, realizado con 11 cuidadores familiares de pacientes adscritos en una Estrategia de Salud de la Familia localizada en el municipio de Santa Maria, Rio Grande do Sul. Los cuidadores familiares fueron indicados por el equipo de salud de la unidad. La recolección de datos ocurrió de julio a septiembre de 2010 y se desarrolló con entrevistas narrativas, orientadas por ejes norteadores. Del análisis de contenido temática surgieron categorías relacionadas a la comunicación y a las relaciones interpersonales entre profesionales, cuidadores familiares y enfermos, además de las interfaces entre los sectores de cuidado a la salud. Hay necesidad de una comunicación efectiva entre los sectores de cuidado, de modo que actúen conjuntamente, permitiendo cambio de saber que auxilien en el enfrentamiento del proceso de enfermedad.<br>The aim of this article is to describe the inter-relation and communication regarding sectors of health care, under the perspective of family caregivers of chronic patients with a disease which causes disability. It is a qualitative, descriptive and exploratory study, with 11 family caregivers registered in a Family Health Strategy in Santa Maria, Rio Grande do Sul. Family caregivers were indicated by the health care team. Data collection happened from July to September of 2010 and was developed through narrative interviews, oriented by guiding themes. Thematic content analysis was carried out and the categories which emerged from such analysis concerned communication and interpersonal relationships among professionals, family caregivers and patients, and the interface among the health care sectors. The need of effective communication among the health care sectors is highlighted, allowing them to act together, enabling an exchange of knowledge that may help throughout the process of facing the disease

Active TGF-β signaling and decreased expression of PTEN separates angiosarcoma of bone from its soft tissue counterpart

Angiosarcomas constitute a heterogeneous group of highly malignant vascular tumors. Angiosarcoma of bone is rare and poorly characterized. For angiosarcoma of soft tissue, some pathways seem to be involved in tumor development. Our aim was to evaluate the role of these pathways in angiosarcoma of bone. We collected 37 primary angiosarcomas of bone and used 20 angiosarcomas of soft tissue for comparison. Immunohistochemistry was performed on constructed tissue microarrays to evaluate expression of CDKN2A, TP53, PTEN, BCL2, CDK4, MDM2, cyclin D1, β-catenin, transforming growth factor-β (TGF-β), CD105, phospho-Smad1, phospho-Smad2, hypoxia-inducible factor-1α, plasminogen activator inhibitor type 1 (PAI-1), VEGF, CD117 and glucose transporter--1. PIK3CA was screened for hotspot mutations in 19 angiosarcomas. In nearly 55% of the angiosarcoma of bone, the retinoblastoma (Rb) pathway was affected. Loss of CDKN2A expression was associated with a significantly worse prognosis. No overexpression of TP53 or MDM2 was found, suggesting that the TP53 pathway is not important in angiosarcoma of bone. Angiosarcoma of bone showed highly active TGF-β signaling with immunoreactivity for phospho-Smad2 and PAI-1. Although the phosphatidylinositol 3-kinase (PI3K)/Akt pathway seems to be active in both tumor groups, different mechanisms were involved: 41% of angiosarcoma of bone showed a decrease in expression of PTEN, whereas in angiosarcoma of soft tissue overexpression of KIT was found (90%). PIK3CA hotspot mutations were absent. In conclusion, the Rb pathway is involved in tumorigenesis of angiosarcoma of bone. The PI3K/Akt pathway is activated in both angiosarcoma of bone and soft tissue, however, with a different cause; PTEN expression is decreased in angiosarcoma of bone, whereas angiosarcomas of soft tissue show overexpression of KIT. Our findings support that angiosarcomas are a heterogeneous group of vascular malignancies. Both angiosarcoma of bone and soft tissue may benefit from therapeutic strategies targeting the PI3K/Akt pathway. However, interference with TGF-β signaling may be specifically relevant in angiosarcoma of bone.Modern Pathology advance online publication, 19 April 2013; doi:10.1038/modpathol.2013.56