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BACKGROUND AND PURPOSE: Quantitative ultrasound (QUS) performed at the distal radius shows potential as an effective tool for evaluating fracture risk, especially in postmenopausal women, but the reliability of this tool has not been reported in this patient population. This study investigated the within-day intrarater and interrater reliability of trained raters performing QUS measures at the distal radius of postmenopausal community-dwelling women. METHODS: Eighteen women between the ages of 56 and 87 years were recruited from senior centers in the Greenville area of South Carolina and consented to participate. A QUS bone sonometer was used in this study; the trained raters performed 3 repeated speed of sound (SOS) measures at the nondominant radius of each participant on the same day. Intraclass correlation coefficients (ICCs) were calculated (model 3,1 for intrarater and 2,3 for interrater reliability) to determine the reliability within and between raters. In addition, we calculated the standard error of measurement (SEM) and the minimal detectable change at 95% confidence interval (MDC95). RESULTS: The within-day intrarater reliability was excellent for both physical therapist raters (ICC(3,1) ranging from 0.93 to 0.91). The SEM and MDC for the within-day intrarater reliability measures were small for both raters (SEM = 36.79-38.75 or 0.92%-0.97% of the pooled mean; MDC95 = 101.99-107.40). The interrater reliability for SOS measurements using radial QUS was good with an ICC(2,3) of 0.77 (95% CI, 0.36-0.92) for 3 averaged measures. The SEM and MDC were larger for the interrater reliability measures (SEM = 62.79 or 1.57% of the pooled mean; MDC95 = 174.05). CONCLUSIONS: Quantitative ultrasound SOS measurement at the distal radius showed excellent within-day intrarater and good interrater (when 3 measures were averaged) reliability in community-dwelling postmenopausal women. The SEM and MDC95 were also low for interrater reliability when a mean of 3 trials was used. This study is the first to demonstrate that this particular QUS device at the radius may be a reliable fracture risk screening tool for postmenopausal women.
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Approximately 20% of breast cancer cases are attributed to increased family risk, yet variation in BRCA1/2 can only explain 20%-25% of cases. Historically, only single gene or single variant testing were common in at-risk family members, and further sequencing studies were rarely offered after negative results. In this study, we applied an efficient and inexpensive targeted sequencing approach to provide molecular diagnoses in 245 human samples representing 134 BRCA mutation-negative (BRCAX) hereditary breast and ovarian cancer (HBOC) families recruited from 1973 to 2019 by Dr. Henry Lynch. Sequencing identified 391 variants, which were functionally annotated and ranked based on their predicted clinical impact. Known pathogenic CHEK2 breast cancer variants were identified in five BRCAX families in this study. While BRCAX was an inclusion criterion for this study, we still identified a pathogenic BRCA2 variant (p.Met192ValfsTer13) in one family. A portion of BRCAX families could be explained by other hereditary cancer syndromes that increase HBOC risk: Li-Fraumeni syndrome (gene: TP53) and Lynch syndrome (gene: MSH6). Interestingly, many families carried additional variants of undetermined significance (VOUSs) that may further modify phenotypes of syndromic family members. Ten families carried more than one potential VOUS, suggesting the presence of complex multi-variant families. Overall, nine BRCAX HBOC families in our study may be explained by known likely pathogenic/pathogenic variants, and six families carried potential VOUSs, which require further functional testing. To address this, we developed a functional assay where we successfully re-classified one family's PMS2 VOUS as benign.
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Proteína BRCA1 , Proteína BRCA2 , Neoplasias da Mama , Predisposição Genética para Doença , Neoplasias Ovarianas , Linhagem , Humanos , Feminino , Proteína BRCA2/genética , Predisposição Genética para Doença/genética , Proteína BRCA1/genética , Neoplasias da Mama/genética , Neoplasias Ovarianas/genética , Síndrome Hereditária de Câncer de Mama e Ovário/genética , Síndrome Hereditária de Câncer de Mama e Ovário/diagnóstico , Adulto , Pessoa de Meia-Idade , Testes Genéticos/métodos , Fenótipo , Mutação , Quinase do Ponto de Checagem 2/genéticaRESUMO
Previous studies support links among maternal-fetal attachment, psychological symptoms, and hormones during pregnancy and the post-partum period. Other studies connect maternal feelings and behaviors to oxytocin and suggest that an increase in oxytocin during pregnancy may prime maternal-fetal attachment. To date, researchers have not examined a possible association between maternal-fetal attachment with human placental lactogen although animal models are suggestive. In the current study, we sought to describe oxytocin and human placental lactogen levels as related to psychological constructs across pregnancy. Seventy women participated in the study. At each of three time-points (early, mid, and late pregnancy), the women had their blood drawn to assess oxytocin and human placental lactogen levels, and they completed psychological assessments measuring maternal-fetal attachment, anxiety, and depression. Our results indicate that oxytocin levels were statistically similar across pregnancy, but that human placental lactogen significantly increased across pregnancy. Results did not indicate significant associations of within-person (comparing individuals to themselves) oxytocin or human placental lactogen levels with maternal-fetal attachment. Additionally, results did not show between-person (comparing individuals to other individuals) oxytocin or human placental lactogen levels with maternal-fetal attachment. Oxytocin levels were not associated with anxiety; rather the stage of pregnancy moderated the effect of the within-person OT level on depression. Notably, increasing levels of human placental lactogen were significantly associated with increasing levels of both anxiety and depression in between subject analyses. The current study is important because it describes typical hormonal and maternal fetal attachment levels during each stage of pregnancy, and because it suggests an association between human placental lactogen and psychological symptoms during pregnancy. Future research should further elucidate these relationships.
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Ansiedade , Depressão , Relações Materno-Fetais , Ocitocina , Lactogênio Placentário , Humanos , Feminino , Ocitocina/sangue , Gravidez , Lactogênio Placentário/sangue , Adulto , Ansiedade/sangue , Ansiedade/psicologia , Depressão/sangue , Depressão/psicologia , Relações Materno-Fetais/psicologia , Relações Materno-Fetais/fisiologia , Adulto Jovem , Apego ao ObjetoRESUMO
Lynch syndrome (LS) is the most common hereditary cancer syndrome. Heterozygous loss-of-function variants in PMS2 are linked to LS. While these variants are not directly cancer causing, reduced PMS2 function results in the accumulation of somatic variants and increased cancer risk over time due to DNA mismatch repair dysfunction. It is reasonable that other types of genetic variation that impact the expression of PMS2 may also contribute to cancer risk. The Kozak sequence is a highly conserved translation initiation motif among higher eukaryotes and is defined as the nine base pairs upstream of the translation start codon through the first four bases of the translated sequence (5'-[GTT]GCATCCATGG-3'; human PMS2: NM_000535.7). While Kozak sequence variants in PMS2 have been reported in ClinVar in patients with suspected hereditary cancer, all variants upstream of the translation start site are currently classified as variants of undetermined significance (VUSs). We hypothesized that variants significantly disrupting the Kozak sequence of PMS2 would decrease PMS2 protein expression, contributing to increased cancer risk over time. Using a dual-luciferase reporter plasmid and site-directed mutagenesis, we generated the wild-type human PMS2 and the ClinVar VUSs within the PMS2 Kozak sequence. Besides the c.1A>C variant, which is already known to be pathogenic, we implicate six additional variants as American College of Medical Genetics and Genomics (ACMG)/Association for Molecular Pathology (AMP) pathogenic supporting (PP) variants and classify ten as benign supporting (BP). In summary, we present a method developed for the classification of human PMS2 Kozak sequence variants that can contribute to the re-classification of VUSs identified in patients.
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Neoplasias Colorretais Hereditárias sem Polipose , Endonuclease PMS2 de Reparo de Erro de Pareamento , Humanos , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Mutação , Predisposição Genética para Doença/genética , Reparo de Erro de Pareamento de DNA/genéticaRESUMO
BACKGROUND: Clinical experiences are foundational learning components for prelicensure nursing students. Given the complexities of modern nursing practice in an aging America, clinical educators must teach nursing students to reason when engaging in patient care. Contemporary pedagogy to enhance reasoning relies on case studies and simulation. Specific and standardized methods for clinical education are largely absent in the literature. METHOD: This pilot study measured the clinical reasoning ability of nursing students using the Health Sciences Reasoning Test (HSRT). Participants completed the test before their first clinical day and again after their last clinical day. Pre- and posttest HSRT scores were analyzed by control and intervention groups as well as student levels. RESULTS: Posttest HSRT scores improved significantly in the intervention group at the end of the semester. CONCLUSION: The PREP framework is a novel approach to clinical education and improved the clinical reasoning of prelicensure nursing students. [J Nurs Educ. 2023;62(8):467-470.].
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Bacharelado em Enfermagem , Estudantes de Enfermagem , Humanos , Projetos Piloto , Bacharelado em Enfermagem/métodos , Pesquisa em Educação em Enfermagem , Resolução de Problemas , Competência ClínicaRESUMO
Pathogenic variants in KMT5B, a lysine methyltransferase, are associated with global developmental delay, macrocephaly, autism, and congenital anomalies (OMIM# 617788). Given the relatively recent discovery of this disorder, it has not been fully characterized. Deep phenotyping of the largest (n = 43) patient cohort to date identified that hypotonia and congenital heart defects are prominent features that were previously not associated with this syndrome. Both missense variants and putative loss-of-function variants resulted in slow growth in patient-derived cell lines. KMT5B homozygous knockout mice were smaller in size than their wild-type littermates but did not have significantly smaller brains, suggesting relative macrocephaly, also noted as a prominent clinical feature. RNA sequencing of patient lymphoblasts and Kmt5b haploinsufficient mouse brains identified differentially expressed pathways associated with nervous system development and function including axon guidance signaling. Overall, we identified additional pathogenic variants and clinical features in KMT5B-related neurodevelopmental disorder and provide insights into the molecular mechanisms of the disorder using multiple model systems.
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Megalencefalia , Transtornos do Neurodesenvolvimento , Animais , Humanos , Camundongos , Haploinsuficiência , Metiltransferases/genética , Camundongos Knockout , Transtornos do Neurodesenvolvimento/genética , FenótipoRESUMO
BACKGROUND: When the COVID-19 pandemic forced colleges and universities to rapidly transition from face-to-face teaching to online teaching/learning environments, different instructional methods were employed to deliver course content and help students remain engaged in learning. With the transition back to the on-campus environment, select online teaching modalities may be effective in the face-to-face environment as well. While online and distance learning have been extensively studied, little research is available to guide faculty in using technologies designed for distance learning in the face-to face environment. PURPOSE: The purpose of this study was to determine pre-licensure baccalaureate nursing student and nursing faculty perceptions of the effectiveness of various online teaching modalities. METHOD: A mixed-methods study using a convenience sample of students and faculty at two universities was conducted. Students and faculty completed a researcher-developed survey to rate a variety of online teaching methods and technologies from a scale of one (not effective at all) through six (extremely effective). Participants also provided comments within the survey and in focus groups of randomly selected students and faculty. Surveyed items included modes of asynchronous and synchronous instruction, instructional technology, and instructional activities. RESULTS: There were significant differences as well as similarities in student and faculty perceptions of effectiveness. Students demonstrated a clear preference for pre-recorded lectures, while faculty perceived synchronous lectures and assigned readings to be equally as effective as pre-recorded lectures. Synchronous activities such as case studies and student presentations were rated as more effective by faculty than by students. Both groups perceived instructional games, especially quiz games, as very or extremely effective. CONCLUSIONS: Students were more engaged with instructional activities that they perceived as effective for learning. The results of this study will assist faculty in developing effective online and in-person instruction which will optimize the teaching/learning experience.
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COVID-19 , Educação a Distância , Estudantes de Enfermagem , Humanos , Pandemias , Docentes de Enfermagem , EnsinoRESUMO
COVID-19 emerged at varying intervals in different regions of the United States in 2020. This report details the epidemiologic and genetic evolution of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the first year of the epidemic in the state of Nebraska using data collected from the Creighton Catholic Health Initiatives (CHI) health system. Statistical modelling identified age, gender, and previous history of diabetes and/or stroke as significant risk factors associated with mortality in COVID-19 patients. In parallel, the viral genomes of over 1,000 samples were sequenced. The overall rate of viral variation in the population was 0.07 mutations/day. Genetically, the first 9 months of the outbreak, which include the initial outbreak, a small surge in August and a major outbreak in November 2020 were primarily characterized by B.1. lineage viruses. In early 2021, the United Kingdom variant (B.1.1.7 or alpha) quickly became the dominant variant. Notably, surveillance of non-consensus variants detected B.1.1.7 defining mutations months earlier in Fall 2020. This work provides insights into the regional variance and evolution of SARS-CoV-2 in the Nebraska region during the first year of the pandemic.
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The 2020 COVID-19 pandemic required schools of nursing to change content delivery to a remote platform. For those who had little or no previous online educational experiences, this change created an array of feelings and emotions in both students and faculty. METHODS: A mixed method exploratory study was used to explore the feelings and emotions of students and faculty associated with the rapid adjustment to changes in delivery of content and its impact on their emotional well-being. RESULTS: Feelings of frustration, stress, and anxiety at the pandemic in general, and toward remote learning in particular were found. The inability to see others in person was also a source of stress. DISCUSSION: Major themes such as increased workload and the displeasure with having didactic content delivery online were major themes. Students prefer mandatory synchronous didactic delivery and were concerned that online clinical experiences may not be as effective as in-person clinical experiences.
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BACKGROUND: Despite widespread interest in adoption, there has been limited systematic examination of Law Enforcement Assisted Diversion (LEAD) implementation, a model for police-led arrest diversion for those with substance use disorders (SUD). In the fall of 2017, the City of New Haven started a LEAD program. During the first 9 months of the pilot, only 2 clients were successfully diverted from arrest. Therefore, we examined the and barriers and facilitators of LEAD implementation. METHODS: We conducted semi-structured interviews and field observations of LEAD police officers and health care providers between August 2018 and June 2019. Interviews and field observations were analyzed using directed content analysis and guided by the Integrated Promoting Action on Research Implementation in Health Services framework. RESULTS: Lead professionals participated in 19 semi-structured interviews and three field observations. Barriers to arrest diversion implementation included procedural complexity of arrest diversion, concerns about reduced penalties for substance use among officers, stigma of SUDs, and a belief in a punitive role for policing. Facilitators included a positive longitudinal relationship with potential clients and an understanding of SUD as a chronic disease. CONCLUSION: We identified several barriers to LEAD implementation. Our results suggest promotion of SUD as a chronic disease, ongoing training of officers, and positive incentives for entering substance use treatment should be utilized to facilitate implementation.
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Aplicação da Lei , Transtornos Relacionados ao Uso de Substâncias , Humanos , Polícia , Avaliação de Programas e Projetos de Saúde , Pesquisa Qualitativa , Estigma SocialRESUMO
Staphylococcus pseudintermedius is a pathogen of veterinary importance, as it is the major causative agent of superficial pyoderma in dogs. We present the complete genome sequences of six strains of S. pseudintermedius derived from dogs affected with epidermal collarettes and superficial bacterial folliculitis, which are two variants of superficial pyoderma.
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Whole-genome sequencing (WGS) has changed our understanding of bacterial pathogens, aiding outbreak investigations and advancing our knowledge of their genetic features. However, there has been limited use of genomics to understand antimicrobial resistance of veterinary pathogens, which would help identify emerging resistance mechanisms and track their spread. The objectives of this study were to evaluate the correlation between resistance genotypes and phenotypes for Staphylococcus pseudintermedius, a major pathogen of companion animals, by comparing broth microdilution antimicrobial susceptibility testing and WGS. From 2017-2019, we conducted antimicrobial susceptibility testing and WGS on S. pseudintermedius isolates collected from dogs in the United States as a part of the Veterinary Laboratory Investigation and Response Network (Vet-LIRN) antimicrobial resistance monitoring program. Across thirteen antimicrobials in nine classes, resistance genotypes correlated with clinical resistance phenotypes 98.4 % of the time among a collection of 592 isolates. Our findings represent isolates from diverse lineages based on phylogenetic analyses, and these strong correlations are comparable to those from studies of several human pathogens such as Staphylococcus aureus and Salmonella enterica. We uncovered some important findings, including that 32.3 % of isolates had the mecA gene, which correlated with oxacillin resistance 97.0 % of the time. We also identified a novel rpoB mutation likely encoding rifampin resistance. These results show the value in using WGS to assess antimicrobial resistance in veterinary pathogens and to reveal putative new mechanisms of resistance.
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Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Monitoramento Epidemiológico/veterinária , Genômica/métodos , Infecções Estafilocócicas/veterinária , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética , Animais , Proteínas de Bactérias/genética , Canadá , Doenças do Cão/microbiologia , Cães/microbiologia , Genômica/normas , Genótipo , Testes de Sensibilidade Microbiana , Fenótipo , Filogenia , Reprodutibilidade dos Testes , Infecções Estafilocócicas/microbiologia , Staphylococcus/isolamento & purificação , Estados Unidos , Sequenciamento Completo do GenomaRESUMO
Transformative advances in metagenomics are providing an unprecedented ability to characterize the enormous diversity of microorganisms and invertebrates sustaining soil health and water quality. These advances are enabling a better recognition of the ecological linkages between soil and water, and the biodiversity exchanges between these two reservoirs. They are also providing new perspectives for understanding microorganisms and invertebrates as part of interacting communities (i.e. microbiomes and zoobiomes), and considering plants, animals, and humans as holobionts comprised of their own cells as well as diverse microorganisms and invertebrates often acquired from soil and water. The Government of Canada's Genomics Research and Development Initiative (GRDI) launched the Ecobiomics Project to coordinate metagenomics capacity building across federal departments, and to apply metagenomics to better characterize microbial and invertebrate biodiversity for advancing environmental assessment, monitoring, and remediation activities. The Project has adopted standard methods for soil, water, and invertebrate sampling, collection and provenance of metadata, and nucleic acid extraction. High-throughput sequencing is located at a centralized sequencing facility. A centralized Bioinformatics Platform was established to enable a novel government-wide approach to harmonize metagenomics data collection, storage and bioinformatics analyses. Sixteen research projects were initiated under Soil Microbiome, Aquatic Microbiome, and Invertebrate Zoobiome Themes. Genomic observatories were established at long-term environmental monitoring sites for providing more comprehensive biodiversity reference points to assess environmental change.
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Metagenômica , Solo , Animais , Biodiversidade , Canadá , Água Doce , HumanosRESUMO
BACKGROUND: IL-13 is a critical effector cytokine for allergic inflammation. It is produced by several cell types, including mast cells, basophils, and TH2 cells. In mast cells and basophils its induction can be stimulated by cross-linkage of immunoglobulin receptors or cytokines. The IL-1 family members IL-33 and IL-18 have been linked to induction of IL-13 production by mast cells and basophils. In CD4 TH2 cells IL-33-mediated production of IL-13 requires simultaneous signal transducer and activator of transcription (STAT) 5 activation. OBJECTIVE: Here we have addressed whether cytokine-induced IL-13 production in mast cells and basophils follows the same logic as in TH2 cells: requirement of 2 separate signals. METHODS: By generating a bacterial artificial chromosome (BAC) transgenic IL-13 reporter mouse, we measured IL-13 production in mast cells and basophils. RESULTS: In mast cells harvested from peritoneal cavities, 2 cytokine signals are required for IL-13 production: IL-33 and IL-3. In bone marrow mast cells IL-13 production requires IL-33, but the requirement for a STAT5 inducer is difficult to evaluate because these cells require the continuous presence of IL-3 (a STAT5 activator) for survival. Poorer STAT5 inducers in culture (IL-4 or stem cell factor) result in less IL-13 production on IL-33 challenge, but the addition of exogenous IL-3 enhances IL-13 production. This implies that bone marrow-derived mast cells, like peritoneal mast cells and TH2 cells, require stimulation both by an IL-1 family member and a STAT5 inducer to secrete IL-13. Basophils follow the same rule; splenic basophils produce IL-13 in response to IL-18 or IL-33 plus IL-3. CONCLUSION: Optimal IL-13 production from mast cells and basophils requires 2 cytokine signals.
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Basófilos/imunologia , Citocinas/imunologia , Mastócitos/imunologia , Animais , Basófilos/efeitos dos fármacos , Células da Medula Óssea/citologia , Células Cultivadas , Citocinas/farmacologia , Proteína 1 Semelhante a Receptor de Interleucina-1 , Mastócitos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores de Interleucina/imunologia , Receptores de Interleucina-18/imunologia , Fator de Transcrição STAT5/imunologiaRESUMO
STUDY DESIGN: Prospective methodological study of repeated measures using a sample of consecutive patients. OBJECTIVE: To determine the test-retest reliability and responsiveness of the Anterior Knee Pain Scale (AKPS) and the Lower Extremity Functional Scale (LEFS) in patients with anterior knee pain. BACKGROUND: Anterior knee pain is one of the most common orthopedic complaints affecting the knee. Yet there is currently no self-report outcome measure that has well-established reliability and responsiveness, specifically for this population. As a result, clinicians and researchers may be making inappropriate conclusions regarding patient outcomes by using questionnaires that are misleading. METHODS AND MEASURES: This multisite study involved 30 patients from 4 outpatient physical therapy clinics in Dallas, TX (24 women, 6 men; age range, 16-50 years; mean+/-SD age, 35.2+/-9.1 years). Patients receiving physical therapy for a chief complaint of anterior knee pain completed the AKPS and LEFS at their initial appointment and again 2 to 3 days later. Upon completion of physical therapy, the patients completed the AKPS, LEFS, and a global rating of change form. The treating therapist also completed a global rating of change form at the patient's final visit. The mean of the patient's and therapist's global rating of change was used as the criterion measure of change. RESULTS: Test-retest reliability was high for both questionnaires (ICC2,1 = 0.95 for the AKPS and 0.98 for the LEFS). A significant correlation was found between the criterion measure of change and both questionnaires. Receiver-operating characteristic curve analysis revealed that both questionnaires were moderately responsive with the area under the curve slightly higher for the LEFS (0.77) than the AKPS (0.69). CONCLUSION: The LEFS and the AKPS both demonstrated high test-retest reliability and appear to be moderately responsive to clinical change in patients with anterior knee pain. Reliability and responsiveness were slightly higher in the LEFS than the AKPS. Further research is needed to determine if these measures could be modified, or new measures created, to produce an even more sensitive tool for this population.
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Traumatismos do Joelho/complicações , Traumatismos do Joelho/diagnóstico , Medição da Dor , Dor/etiologia , Inquéritos e Questionários , Adolescente , Adulto , Feminino , Humanos , Traumatismos do Joelho/patologia , Perna (Membro)/fisiologia , Masculino , Pessoa de Meia-Idade , Ortopedia/métodos , Estudos Prospectivos , Amplitude de Movimento Articular , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Expression of the transcription factor GATA-3 is strongly associated with T helper type 2 (T(H)2) differentiation, but genetic evidence for its involvement in this process has been lacking. Here, we generated a conditional GATA-3-deficient mouse line. In vitro deletion of Gata3 diminished both interleukin 4 (IL-4)-dependent and IL-4-independent T(H)2 cell differentiation; without GATA-3, T(H)1 differentiation occurred in the absence of IL-12 and interferon-gamma. Gata3 deletion limited the growth of T(H)2 cells but not T(H)1 cells. Deletion of Gata3 from established T(H)2 cells abolished IL-5 and IL-13 but not IL-4 production. In vivo deletion of Gata3 using OX40-Cre eliminated T(H)2 responses and allowed the development of interferon-gamma-producing cells in mice infected with Nippostrongylus brasiliensis. Thus, GATA-3 serves as a principal switch in determining T(H)1-T(H)2 responses.
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Proteínas de Ligação a DNA/genética , Células Th1/imunologia , Células Th2/imunologia , Transativadores/genética , Animais , Diferenciação Celular/imunologia , Diferenciação Celular/fisiologia , Divisão Celular/imunologia , Divisão Celular/fisiologia , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/imunologia , Fator de Transcrição GATA3 , Deleção de Genes , Camundongos , Células Th1/metabolismo , Células Th2/metabolismo , Células Th2/fisiologia , Transativadores/deficiência , Transativadores/imunologiaRESUMO
TH2 clones may produce very variable amounts of IL-4. Among six TH2 clones prepared from homozygous or heterozygous mice in which Gfp replaced the first exon of Il4, a range of patterns of CpG methylation in the Il4/Il13 locus was observed correlating with the degree of expression of IL-4 or green fluorescence protein. Patterns of histone acetylation also showed differences between "high" and "low" TH2 clones. These results indicate that in TH2 cells the Il4 locus may display variable patterns of chromatin accessibility associated with distinct degrees of IL-4 expression. This finding suggests a regulation of IL-4 expression keyed to the function of this cytokine in cell/cell interactions and in the regulation of threshold responses.
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Azacitidina/análogos & derivados , Metilação de DNA , Interleucina-4/genética , Células Th2/imunologia , Acetilação , Animais , Azacitidina/farmacologia , Células Cultivadas , Metilases de Modificação do DNA/antagonistas & inibidores , Decitabina , Expressão Gênica , Proteínas de Fluorescência Verde , Histonas/metabolismo , Interleucina-13/genética , Proteínas Luminescentes/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células Th1/imunologia , Células Th2/citologia , Fatores de Transcrição/genéticaRESUMO
IL-4 is important in Th2 differentiation and in cell expansion. Stat6 is necessary and sufficient for both functions. Although Gata3 is critical for Th2 polarization, it is not sufficient to mediate IL-4-driven cell expansion. We report that growth factor independent-1 (Gfi-1), a Stat6-dependent transcriptional repressor, strikingly increases Th2 cell expansion by promoting proliferation and preventing apoptosis. Cells infected with a Gfi-1 retrovirus show striking enhancement of IL-2-induced Stat5 phosphorylation and repression of p27(Kip-1) expression, suggesting a potential mechanism for the Gfi-1 growth effect. The synergy of Gfi-1 and Gata3 provides a mechanism through which IL-4 could selectively promote Th2 cell expansion.