RESUMO
BACKGROUND: Pharmacogenomics is the study of how genes affect a person's response to drugs. This descriptive study assessed whether popular drug information resources provide clinically useful pharmacogenomic (PGx) information. METHODS: Four resources (package inserts, Lexicomp, Micromedex 2.0, and Epocrates) were evaluated for information about twenty-seven drugs. RESULTS: There was wide variability of PGx information. Whereas Lexicomp included relevant PGx biomarker information for all 27 drugs, Epocrates did in less than 50% of the drugs. None of the resources had monographs that fully incorporated Clinical Pharmacogenomics Implementation Consortium (CPIC) recommendations in more than 30% of the drugs. CONCLUSION: Lexicomp appears to be most useful PGx drug information resource, but none of the resources are sufficient.
Assuntos
Bases de Dados como Assunto , Bases de Dados Factuais/normas , Serviços de Informação sobre Medicamentos/normas , Farmacogenética/educação , Humanos , Sensibilidade e EspecificidadeRESUMO
Decoupling of transcription and translation during postmeiotic germ cell differentiation is critical for successful spermatogenesis. Here we establish that the interaction between microRNAs and actin-associated protein Arpc5 sets the stage for an elaborate translational control mechanism by facilitating the sequestration of germ cell mRNAs into translationally inert ribonucleoprotein particles until they are later translated. Our studies reveal that loss of microRNA-dependent regulation of Arpc5, which controls the distribution of germ cell mRNAs between translationally active and inactive pools, results in abnormal round spermatid differentiation and impaired fertility. Interestingly, Arpc5 functions as a broadly acting translational suppressor, as it inhibits translation initiation by blocking 80S formation and facilitates the transport of mRNAs to chromatoid/P bodies. These findings identify a unique role for actin-associated proteins in translational regulation, and suggest that mRNA-specific and general translational control mechanisms work in tandem to regulate critical germ cell differentiation events and diverse somatic cell functions.
Assuntos
Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Diferenciação Celular/genética , MicroRNAs/metabolismo , Espermatozoides/metabolismo , Espermatozoides/patologia , Animais , Sequência de Bases , Cromatina/metabolismo , Ativação Enzimática , Regulação da Expressão Gênica , Haploidia , Células HeLa , Humanos , Masculino , Meiose/genética , Camundongos , MicroRNAs/genética , Dados de Sequência Molecular , Protaminas/metabolismo , Ligação Proteica , Biossíntese de Proteínas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reprodução , Ribonuclease III/metabolismo , Ribossomos/metabolismo , Cabeça do Espermatozoide/metabolismo , Cabeça do Espermatozoide/patologia , Cabeça do Espermatozoide/ultraestrutura , Testículo/anormalidades , Testículo/patologia , Testículo/ultraestruturaRESUMO
In Saccharomyces cerevisiae, transcriptional silencing occurs at three classes of genomic regions: near the telomeres, at the silent mating type loci, and within the ribosomal DNA (rDNA) repeats. In all three cases, silencing depends upon several factors, including specific types of histone modifications. In this work we have investigated the roles in silencing for Spt10 and Spt21, two proteins previously shown to control transcription of particular histone genes. Building on a recent study showing that Spt10 is required for telomeric silencing, our results show that in both spt10 and spt21 mutants, silencing is reduced near telomeres and at HMLα, while it is increased at the rDNA. Both spt10 and spt21 mutations cause modest effects on Sir protein recruitment and histone modifications at telomeric regions, and they cause significant changes in chromatin structure, as judged by its accessibility to dam methylase. These silencing and chromatin changes are not seen upon deletion of HTA2-HTB2, the primary histone locus regulated by Spt10 and Spt21. These results suggest that Spt10 and Spt21 control silencing in S. cerevisiae by altering chromatin structure through roles beyond the control of histone gene expression.
Assuntos
Histona Acetiltransferases/fisiologia , Proteínas de Saccharomyces cerevisiae/fisiologia , Saccharomyces cerevisiae/genética , Fatores de Transcrição/fisiologia , Cromatina/química , Cromatina/metabolismo , DNA Ribossômico/genética , Regulação para Baixo , Inativação Gênica , Histonas/metabolismo , Processamento de Proteína Pós-Traducional , Saccharomyces cerevisiae/metabolismo , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/metabolismo , Telômero/genética , Telômero/metabolismoRESUMO
Specialized oxygen-sensing cells in the nervous system generate rapid behavioural responses to oxygen. We show here that the nematode Caenorhabditis elegans exhibits a strong behavioural preference for 5-12% oxygen, avoiding higher and lower oxygen levels. 3',5'-cyclic guanosine monophosphate (cGMP) is a common second messenger in sensory transduction and is implicated in oxygen sensation. Avoidance of high oxygen levels by C. elegans requires the sensory cGMP-gated channel tax-2/tax-4 and a specific soluble guanylate cyclase homologue, gcy-35. The GCY-35 haem domain binds molecular oxygen, unlike the haem domains of classical nitric-oxide-regulated guanylate cyclases. GCY-35 and TAX-4 mediate oxygen sensation in four sensory neurons that control a naturally polymorphic social feeding behaviour in C. elegans. Social feeding and related behaviours occur only when oxygen exceeds C. elegans' preferred level, and require gcy-35 activity. Our results suggest that GCY-35 is regulated by molecular oxygen, and that social feeding can be a behavioural strategy for responding to hyperoxic environments.
Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/fisiologia , Comportamento Alimentar/fisiologia , Guanilato Ciclase/metabolismo , Oxigênio/metabolismo , Comportamento Social , Animais , Bactérias/genética , Bactérias/metabolismo , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/genética , Agregação Celular/efeitos dos fármacos , GMP Cíclico/metabolismo , Comportamento Alimentar/efeitos dos fármacos , Alimentos , Gases/metabolismo , Guanilato Ciclase/química , Guanilato Ciclase/genética , Heme/metabolismo , Hiperóxia/enzimologia , Hiperóxia/genética , Hiperóxia/metabolismo , Canais Iônicos/metabolismo , Mutação/genética , Neurônios Aferentes/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico/farmacologia , Oxigênio/farmacologia , Ligação Proteica , Estrutura Terciária de ProteínaRESUMO
PURPOSE: The purpose of this study is to explore the feasibility of the use of titanium fiducial markers to minimize the metallic artifact seen with tantalum markers which causes significant distortion on postoperative orbital CT scans. METHOD: We designed and constructed the titanium markers in the shop of Crocker Nuclear Laboratory, UC Davis, CA. The markers were placed on an eyeball phantom. The eyeball was inserted into the Rando phantom in the orbital space. The Rando phantom was imaged with coplanar x rays on Nucletron simulator at UCSF, on digital panel on the eye beam line at CNL eye treatment facility and on CT scanner at UCSF. RESULTS: The titanium markers can be clearly seen on the hard copy of x rays and on digital panel. The CT scan of an orbit using tantalum markers on the right eye and titanium markers on the left eye shows the metal artifact from tantalum markers. Titanium markers show very little distortion on CT images. CONCLUSION: The present study describes these markers and their relative benefit in comparison with tantalum marker, which has been used for localizing ocular tumor for decades.
Assuntos
Neoplasias da Coroide/radioterapia , Marcadores Fiduciais , Melanoma/radioterapia , Terapia com Prótons , Titânio , Neoplasias da Coroide/diagnóstico por imagem , Estudos de Viabilidade , Humanos , Melanoma/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
Stereotactic radiosurgery provides conformal treatment of intracranial lesions, but when multiple lesions are treated, cumulative dose to structures such as the hippocampi may be increased. We analyzed hippocampal dose for patients treated with radiosurgery for multiple brain metastases. We then investigated a means to minimize hippocampal dose. We randomly selected 8 patients treated with single-session, frame-based radiosurgery for 6 to 12 intracranial metastases. Standard planning was employed to deliver 16 to 20 Gy to each lesion without hippocampal avoidance. Each case was replanned using the software's dynamic shaping function to minimize direct beam hippocampal irradiation, while maintaining conformality and target coverage. With standard planning, the maximum hippocampal dose varied from 0.8 to 9.0 Gy but was >3 Gy only when a lesion was <10 mm from the hippocampus. There was no clear correlation between hippocampal dose and the number or the total volume of lesions. Replanning with direct beam avoidance decreased the mean hippocampal dose by an average of 35% but increased treatment time by a mean of 20%. Sparing was most pronounced when the closest lesion was in close proximity to the hippocampus. This is the first study reporting hippocampal dose for multilesion intracranial radiosurgery. It illustrates that when multiple intracranial targets are treated with radiosurgery, substantial hippocampal dose can result. Active beam shielding and optimization can lower hippocampal dose, especially with lesions <10 mm from the hippocampus. These results raise the prospect that the risk of neurocognitive side effects may be further decreased with a hippocampal-sparing approach.
Assuntos
Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/radioterapia , Hipocampo/patologia , Hipocampo/efeitos da radiação , Radiocirurgia , Dosagem Radioterapêutica , Neoplasias Encefálicas/secundário , Humanos , Tratamentos com Preservação do Órgão , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador , Carga TumoralRESUMO
PURPOSE/OBJECTIVES: Whole-brain radiation for brain metastases can result in cognitive side effects. Hippocampal-sparing techniques have been developed to decrease morbidity, but they carry the risk of underdosing lesions near the hippocampus due to the unavoidable dose gradient from the hippocampal surface to the prescription isodose surface. This study examines the impact of variable levels of hippocampal sparing on the underdosing of potential brain metastases. MATERIALS/METHODS: Helical intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans were developed for hippocampal-sparing whole-brain treatment. For all plans, 30Gy was prescribed in 10 fractions to result in mean hippocampal doses of 6-12Gy. From a series of expanded shells, we determined the distance from the hippocampus at which the parenchyma would receive less than specified doses. Then, using published data, a mathematical model was constructed to predict the incident probability of potential brain metastases receiving different doses for different levels of hippocampal sparing. RESULTS: Whole-brain radiation plans were able to spare the hippocampi to mean doses of 7-12Gy under our planning constraints; more stringent constraints compromised brain coverage. The dose gradients were â¼4% per mm, regardless of the hippocampal constraint, and they decreased sharply by a factor of almost 4 at approximately 15mm from the hippocampi. A mathematical model was constructed and combined the plan information with published data on the distribution of brain metastases, to determine the percentage of potential brain metastases receiving specified doses, as a function of technique and level of hippocampal sparing. CONCLUSIONS: Our results describe the characteristics of an array of hippocampal-sparing whole-brain radiation dose distributions. These can be used as a decision-making guideline for weighing the benefit of decreased dose to the hippocampi against the cost of decreased dose to potential brain metastases when deciding on a hippocampal-sparing whole-brain irradiation treatment approach.
Assuntos
Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundário , Hipocampo/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias Encefálicas/diagnóstico por imagem , Irradiação Craniana/métodos , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Humanos , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/métodosRESUMO
INTRODUCTION/BACKGROUND: We evaluated heart dose from left breast radiotherapy with 2-dimensional (2D) versus 3-dimensional (3D) plans. PATIENTS AND METHODS: Treatment plans from patients treated with standard fractionation for left breast cancer from 2003 to 2013 were reviewed, with patients grouped into 3 cohorts: 2003 to 2004 ("2D", with computed tomography scans for dose calculation but fields defined using simulation films; n = 29), 2005 to 2006 ("2D-post," after several influential articles on heart dose were published; n = 31), and 2007 to 2013 ("3D"; n = 256). All patients were treated with free-breathing technique. Heart volumes were retrospectively contoured for the earlier 2 cohorts. Mean heart dose (MHD) and percentage of structure receiving at least 25 Gy (V25 Gy) and percentage of structure receiving at least 5 Gy for the whole heart, left ventricle (LV), right ventricle (RV), and both ventricles were recorded and compared among cohorts. RESULTS: MHD was 345 cGy (2D), 213 cGy (2D-post) and 213 cGy (3D). LV V25 Gy was 6.3%, 1.5%, and 1.1%, respectively. Lower doses were seen over time for all indices (analysis of variance, P < .0001). Post hoc tests indicated significantly higher doses for 2D versus 2D-post or 3D cohorts (P ≤ .001) for all parameters except RV V25 Gy (P = .24). CONCLUSION: Heart doses were higher with 2D versus 3D plans. Cardiac doses and resulting toxicity with modern 3D planning might be lower than those in previous reports.
Assuntos
Coração/efeitos da radiação , Lesões por Radiação/prevenção & controle , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Adjuvante/efeitos adversos , Neoplasias Unilaterais da Mama/radioterapia , Mama/diagnóstico por imagem , Fracionamento da Dose de Radiação , Feminino , Humanos , Imageamento Tridimensional , Dosagem Radioterapêutica , Radioterapia Adjuvante/métodos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Neoplasias Unilaterais da Mama/diagnóstico por imagemRESUMO
Spt10 is a putative acetyltransferase of Saccharomyces cerevisiae that directly activates the transcription of histone genes. Deletion of SPT10 causes a severe slow growth phenotype, showing that Spt10 is critical for normal cell division. To gain insight into the function of Spt10, we identified mutations that impair or improve the growth of spt10 null (spt10Δ) mutants. Mutations that cause lethality in combination with spt10Δ include particular components of the SAGA complex as well as asf1Δ and hir1Δ. Partial suppressors of the spt10Δ growth defect include mutations that perturb cell-cycle progression through the G1/S transition, S phase, and G2/M. Consistent with these results, slowing of cell-cycle progression by treatment with hydroxyurea or growth on medium containing glycerol as the carbon source also partially suppresses the spt10Δ slow-growth defect. In addition, mutations that impair the Lsm1-7-Pat1 complex, which regulates decapping of polyadenylated mRNAs, also partially suppress the spt10Δ growth defect. Interestingly, suppression of the spt10Δ growth defect is not accompanied by a restoration of normal histone mRNA levels. These findings suggest that Spt10 has multiple roles during cell division.
Assuntos
Histona Acetiltransferases/metabolismo , Interfase , Mutação , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/citologia , Fatores de Transcrição/metabolismo , Meios de Cultura/metabolismo , Elementos de DNA Transponíveis , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Histona Acetiltransferases/genética , Histonas/genética , Histonas/metabolismo , Hidroxiureia/farmacologia , Viabilidade Microbiana , Mutagênese Insercional , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo , Proteínas de Ligação ao Cap de RNA/genética , Proteínas de Ligação ao Cap de RNA/metabolismo , RNA Fúngico/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Fatores de Transcrição/genéticaRESUMO
A thorough understanding of the events during mammalian spermatogenesis requires studying specific molecular signatures of individual testicular cell populations as well as their interaction in co-cultures. However, most purification techniques to isolate specific testicular cell populations are time-consuming, require large numbers of animals, and/or are only able to isolate a few cell types. Here we describe a cost-effective and timesaving approach that uses a single protocol to enrich multiple testicular cell populations (Sertoli, Leydig, and several spermatogenic cell populations) from as few as one mouse. Our protocol combines rigorous enzymatic digestion of seminiferous tubules with counter-current centrifugal elutriation, yielding specific testicular cell populations with >80%-95% purity.
Assuntos
Separação Celular/métodos , Células Intersticiais do Testículo/citologia , Células de Sertoli/citologia , Espermatogônias/citologia , Testículo/citologia , Animais , Separação Celular/economia , Masculino , Camundongos , Túbulos Seminíferos/metabolismoRESUMO
Though roles of ß-catenin signaling during testis development have been well established, relatively little is known about its role in postnatal testicular physiology. Even less is known about its role in post-meiotic germ cell development and differentiation. Here, we report that ß-catenin is highly expressed in post-meiotic germ cells and plays an important role during spermiogenesis in mice. Spermatid-specific deletion of ß-catenin resulted in significantly reduced sperm count, increased germ cell apoptosis and impaired fertility. In addition, ultrastructural studies show that the loss of ß-catenin in post-meiotic germ cells led to acrosomal defects, anomalous release of immature spermatids and disruption of adherens junctions between Sertoli cells and elongating spermatids (apical ectoplasmic specialization; ES). These defects are likely due to altered expression of several genes reportedly involved in Sertoli cell-germ cell adhesion and germ cell differentiation, as revealed by gene expression analysis. Taken together, our results suggest that ß-catenin is an important molecular link that integrates Sertoli cell-germ cell adhesion with the signaling events essential for post-meiotic germ cell development and maturation. Since ß-catenin is also highly expressed in the Sertoli cells, we propose that binding of germ cell ß-catenin complex to ß-catenin complex on Sertoli cell at the apical ES surface triggers a signaling cascade that regulates post-meiotic germ cell differentiation.