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1.
Hong Kong Med J ; 30(4): 281-290, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39009479

RESUMEN

INTRODUCTION: Human immunodeficiency virus (HIV)-associated tuberculosis (TB) remains an important health challenge worldwide. Although TB prevalence has decreased in the general population, there is limited information regarding temporal trends in the incidence of HIV-associated TB in Hong Kong. There are also insufficient data regarding changes in clinical manifestation patterns among HIV-associated TB patients over time. This study aimed to describe temporal trends in the epidemiology and clinical manifestations of HIV-associated TB in Hong Kong. METHODS: We retrospectively reviewed data regarding HIV-associated TB patients that were reported to the TB-HIV Registry of the Department of Health during the period 2007 to 2020. Trends of TB as a primary acquired immunodeficiency syndrome (AIDS)-defining illness, as well as changes in demographic features and clinical manifestations of HIV-associated TB during this period were examined using Cochran-Armitage trend test. RESULTS: A decreasing trend was observed in the proportion of all reported cases of AIDS in which TB was a primary AIDS-defining illness during the study period. The proportions of female patients and patients with extrapulmonary involvement significantly increased, whereas the proportions of ever-smokers and patients with sputum smear positivity significantly decreased during the same period. A decreasing trend was observed in the proportion of patients with pulmonary TB in which the lower zone was the predominant site of lung parenchymal lesions. Among patients with a diagnosis of HIV infection before TB, an increasing trend was observed in the proportion of patients receiving antiretroviral therapy. CONCLUSION: Important temporal changes were observed in the epidemiology and clinical manifestations of HIV-associated TB. These results highlight the need for continued surveillance regarding the patterns of demographic features and clinical manifestations to inform policymakers when planning control strategies for HIV-associated TB.


Asunto(s)
Infecciones por VIH , Humanos , Hong Kong/epidemiología , Femenino , Masculino , Estudios Retrospectivos , Adulto , Infecciones por VIH/epidemiología , Infecciones por VIH/complicaciones , Persona de Mediana Edad , Incidencia , Tuberculosis/epidemiología , Prevalencia , Infecciones Oportunistas Relacionadas con el SIDA/epidemiología , Tuberculosis Pulmonar/epidemiología , Adulto Joven , Sistema de Registros
2.
Hum Reprod ; 35(6): 1332-1345, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32474592

RESUMEN

STUDY QUESTION: Does women's age affect the DNA methylation (DNAm) profile differently in mural granulosa cells (MGCs) from other somatic cells? SUMMARY ANSWER: Accumulation of epimutations by age and a higher number of age-related differentially methylated regions (DMR) in MGCs were found compared to leukocytes from the same woman, suggesting that the MGCs have a distinctive epigenetic profile. WHAT IS KNOWN ALREADY: The mechanisms underlying the decline in women's fertility from the mid-30s remain to be fully elucidated. The DNAm age of many healthy tissues changes predictably with and follows chronological age, but DNAm age in some reproductive tissues has been shown to depart from chronological age (older: endometrium; younger: cumulus cells, spermatozoa). STUDY DESIGN, SIZE, DURATION: This study is a multicenter cohort study based on retrospective analysis of prospectively collected data and material derived from healthy women undergoing IVF or ICSI treatment following ovarian stimulation with antagonist protocol. One hundred and nineteen women were included from September 2016 to June 2018 from four clinics in Denmark and Sweden. PARTICIPANTS/MATERIALS, SETTING, METHODS: Blood samples were obtained from 118 healthy women with varying ovarian reserve status. MGCs were collected from 63 of the 119 women by isolation from pooled follicles immediately after oocyte retrieval. DNA from leukocytes and MGCs was extracted and analysed with a genome-wide methylation array. Data from the methylation array were processed using the ENmix package. Subsequently, DNAm age was calculated using established and tailored age predictors and DMRs were analysed with the DMRcate package. MAIN RESULTS AND ROLE OF CHANCE: Using established age predictors, DNAm age in MGCs was found to be considerable younger and constant (average: 2.7 years) compared to chronological age (average: 33.9 years). A Granulosa Cell clock able to predict the age of both MGCs (average: 32.4 years) and leukocytes (average: 38.8 years) was successfully developed. MGCs differed from leukocytes in having a higher number of epimutations (P = 0.003) but predicted telomere lengths unaffected by age (Pearson's correlation coefficient = -0.1, P = 0.47). DMRs associated with age (age-DMRs) were identified in MGCs (n = 335) and in leukocytes (n = 1) with a significant enrichment in MGCs for genes involved in RNA processing (45 genes, P = 3.96 × 10-08) and gene expression (152 genes, P = 2.3 × 10-06). The top age-DMRs included the metastable epiallele VTRNA2-1, the DNAm regulator ZFP57 and the anti-Müllerian hormone (AMH) gene. The apparent discordance between different epigenetic measures of age in MGCs suggests that they reflect difference stages in the MGC life cycle. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: No gene expression data were available to associate with the epigenetic findings. The MGCs are collected during ovarian stimulation, which may influence DNAm; however, no correlation between FSH dose and number of epimutations was found. WIDER IMPLICATIONS OF THE FINDINGS: Our findings underline that the somatic compartment of the follicle follows a different methylation trajectory with age than other somatic cells. The higher number of epimutations and age-DMRs in MGCs suggest that their function is affected by age. STUDY FUNDING/COMPETING INTEREST(S): This project is part of ReproUnion collaborative study, co-financed by the European Union, Interreg V ÖKS, the Danish National Research Foundation and the European Research Council. The authors declare no conflict of interest.


Asunto(s)
Envejecimiento , Células de la Granulosa , Adulto , Envejecimiento/genética , Preescolar , Estudios de Cohortes , Epigénesis Genética , Femenino , Humanos , Masculino , Estudios Retrospectivos , Suecia
3.
Soc Psychiatry Psychiatr Epidemiol ; 55(3): 339-349, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31501908

RESUMEN

INTRODUCTION: Adverse childhood experiences (ACEs) constitute a significant global mental health burden. Prior studies typically investigated the impact of ACEs on mental health using a cumulative risk approach; most ACEs studies were also conducted in Western settings. PURPOSE: This study aimed to examine ACEs using a pattern-based approach and assess their associations with mental health outcomes by early adulthood in East Asia. METHODS: The present study included measures of exposure to 13 categories of ACEs, depression, anxiety, maladjustment, and posttraumatic stress in a sample of 1346 university students from Hong Kong, China, Taiwan, and Japan. RESULTS: Latent class analysis indicated three distinct patterns of ACE exposure: Class 1: Low ACEs (76.0%); Class 2: Household Violence (20.6%); and Class 3: Household Dysfunction (3.4%). Those representing Class 3 had significantly more ACEs compared with those in Classes 1 or 2. Controlling for age and sex, those in Class 2 reported significantly higher depression and maladjustment symptoms compared with those in Class 1; both Classes 2 and 3 had significantly higher anxiety symptoms and odds for meeting diagnostic criteria for posttraumatic stress disorders compared with those in Class 1. CONCLUSIONS: Study findings suggest that young adults' mental health, at least under certain contexts, is more closely linked with the nature and pattern of ACE co-occurrence, rather than the number of ACEs.


Asunto(s)
Experiencias Adversas de la Infancia , Salud Mental , Estudiantes , Adolescente , China , Depresión , Femenino , Hong Kong , Humanos , Japón , Masculino , Trastornos Mentales , Estudiantes/psicología , Encuestas y Cuestionarios , Taiwán , Universidades , Violencia , Adulto Joven
6.
Br J Surg ; 104(13): 1775-1784, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29091283

RESUMEN

BACKGROUND: Hepatic resection and radiofrequency ablation (RFA) are treatment options for early-stage hepatocellular carcinoma (HCC). Whether tumour recurrence and long-term survival favour either treatment has not been established. This randomized trial aimed to test the hypothesis that RFA is superior to hepatic resection in terms of lower tumour recurrence rate and better long-term survival. METHODS: Patients with early-stage HCC (solitary tumour no larger than 5 cm; or no more than 3 tumours, each 3 cm or smaller) were randomized into hepatic resection and RFA groups. Demographic and clinical characteristics, and short- and long-term outcome measures were compared between groups. Primary and secondary outcome measures were overall tumour recurrence and survival respectively. RESULTS: Clinicopathological data were similar in the two groups, which each contained 109 patients. The RFA group had a shorter treatment duration, less blood loss and shorter hospital stay than the resection group. Mortality and morbidity rates were similar in the two groups. The overall tumour recurrence rate was similar in the resection and RFA groups (71·3 versus 81·7 per cent respectively). The 1-, 3-, 5- and 10-year overall survival rates were 94·5, 80·6, 66·5 and 47·6 per cent respectively in the resection group, compared with 95·4, 82·3, 66·4 and 41·8 per cent in the RFA group (P = 0·531). Corresponding disease-free survival rates were 74·1, 50·9, 41·5 and 31·9 per cent in the resection group, and 70·6, 46·6, 33·6 and 18·6 per cent in the RFA group (P = 0·072). CONCLUSION: RFA for early-stage HCC is not superior to hepatic resection, in terms of tumour recurrence, overall survival and disease-free survival. Registration number: HKUCTR-10 (http://www.hkuctr.com).


Asunto(s)
Carcinoma Hepatocelular/mortalidad , Carcinoma Hepatocelular/cirugía , Ablación por Catéter , Hepatectomía , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/cirugía , Recurrencia Local de Neoplasia , Adulto , Anciano , Anciano de 80 o más Años , Pérdida de Sangre Quirúrgica , Carcinoma Hepatocelular/patología , Colorantes , Supervivencia sin Enfermedad , Femenino , Hepatitis C/complicaciones , Hong Kong/epidemiología , Humanos , Verde de Indocianina , Tiempo de Internación , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pronóstico , Adulto Joven
7.
Ann Surg Oncol ; 23(4): 1335-43, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26646946

RESUMEN

BACKGROUND: Extended liver resections in patients with hepatocellular carcinoma (HCC) are problematic due to hepatitis, fibrosis, and cirrhosis. Associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) has been promoted as a novel method to induce hypertrophy for patients with extensive colorectal liver metastases, but outcomes in HCC have not been well investigated. METHODS: All patients registered in the international ALPPS Registry ( www.alpps.org ) from 2010 to 2015 were studied. Hypertrophy of the future liver remnant, perioperative morbidity and mortality, age, overall survival, and other parameters were compared between patients with HCC and patients with colorectal liver metastases (CRLM). RESULTS: The study compared 35 patients with HCC and 225 patients with CRLM. The majority of patients undergoing ALPPS for HCC fall into the intermediate-stage category of the Barcelona clinic algorithm. In this study, hypertrophy was rapid and extensive for the HCC patients, albeit lower than for the CRLM patients (47 vs. 76 %; p < 0.002). Hypertrophy showed a linear negative correlation with the degrees of fibrosis. The 90-day mortality for ALPPS used to treat HCC was almost fivefold higher than for CRLM (31 vs. 7 %; p < 0.001). Multivariate analysis showed that patients older than 61 years had a significantly reduced overall survival (p < 0.004). CONCLUSION: The ALPPS approach induces a considerable hypertrophic response in HCC patients and allows resection of intermediate-stage HCC, albeit at the cost of a 31 % perioperative mortality rate. The use of ALPPS for HCC remains prohibitive for most patients and should be performed only for a highly selected patient population younger than 60 years with low-grade fibrosis.


Asunto(s)
Carcinoma Hepatocelular/cirugía , Neoplasias Colorrectales/cirugía , Hepatectomía , Neoplasias Hepáticas/cirugía , Vena Porta/cirugía , Procedimientos Quirúrgicos Vasculares/métodos , Anciano , Carcinoma Hepatocelular/patología , Neoplasias Colorrectales/patología , Femenino , Estudios de Seguimiento , Humanos , Ligadura , Neoplasias Hepáticas/secundario , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Estadificación de Neoplasias , Vena Porta/patología , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia
8.
Clin Exp Immunol ; 175(1): 49-58, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24032527

RESUMEN

The causes of multiple myeloma (MM) remain obscure and there are few known risk factors; however, natural killer T (NKT) cell abnormalities have been reported in patients with MM, and therapeutic targeting of NKT cells is promoted as a potential treatment. We characterized NKT cell defects in treated and untreated patients with MM and determined the impact of lenalidomide therapy on the NKT cell pool. Lenalidomide is an immunomodulatory drug with co-stimulatory effects on NKT cells in vitro and is an approved treatment for MM, although its mode of action in that context is not well defined. We find that patients with relapsed/progressive MM had a marked deficiency in NKT cell numbers. In contrast, newly diagnosed patients had relatively normal NKT cell frequency and function prior to treatment, although a specific NKT cell deficiency emerged after high-dose melphalan and autologous stem cell transplantation (ASCT) regimen. This also impacted NK cells and conventional T cells, but the recovery of NKT cells was considerably delayed, resulting in a prolonged, treatment-induced NKT cell deficit. Longitudinal analysis of individual patients revealed that lenalidomide therapy had no in-vivo impact on NKT cell numbers or cytokine production, either as induction therapy, or as maintenance therapy following ASCT, indicating that its clinical benefits in this setting are independent of NKT cell modulation.


Asunto(s)
Factores Inmunológicos/administración & dosificación , Mieloma Múltiple , Células T Asesinas Naturales , Talidomida/análogos & derivados , Citocinas/sangre , Citocinas/inmunología , Femenino , Humanos , Lenalidomida , Recuento de Linfocitos , Masculino , Mieloma Múltiple/sangre , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/inmunología , Mieloma Múltiple/patología , Células T Asesinas Naturales/inmunología , Células T Asesinas Naturales/metabolismo , Células T Asesinas Naturales/patología , Talidomida/administración & dosificación
9.
Clin Exp Immunol ; 172(1): 129-37, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23480193

RESUMEN

Our understanding of human type 1 natural killer T (NKT) cells has been heavily dependent on studies of cells from peripheral blood. These have identified two functionally distinct subsets defined by expression of CD4, although it is widely believed that this underestimates the true number of subsets. Two recent studies supporting this view have provided more detail about diversity of the human NKT cells, but relied on analysis of NKT cells from human blood that had been expanded in vitro prior to analysis. In this study we extend those findings by assessing the heterogeneity of CD4(+) and CD4(-) human NKT cell subsets from peripheral blood, cord blood, thymus and spleen without prior expansion ex vivo, and identifying for the first time cytokines expressed by human NKT cells from spleen and thymus. Our comparative analysis reveals highly heterogeneous expression of surface antigens by CD4(+) and CD4(-) NKT cell subsets and identifies several antigens whose differential expression correlates with the cytokine response. Collectively, our findings reveal that the common classification of NKT cells into CD4(+) and CD4(-) subsets fails to reflect the diversity of this lineage, and that more studies are needed to establish the functional significance of the antigen expression patterns and tissue residency of human NKT cells.


Asunto(s)
Antígenos CD4/inmunología , Linfocitos T CD4-Positivos/inmunología , Heterogeneidad Genética , Células T Asesinas Naturales/inmunología , Subgrupos de Linfocitos T/inmunología , Timo/inmunología , Antígenos CD4/genética , Linfocitos T CD4-Positivos/citología , Células Cultivadas , Citocinas/biosíntesis , Citocinas/inmunología , Sangre Fetal/citología , Sangre Fetal/inmunología , Feto , Expresión Génica , Humanos , Inmunofenotipificación , Células T Asesinas Naturales/citología , Especificidad de Órganos , Subgrupos de Linfocitos T/citología , Timo/citología
10.
Med J Malaysia ; 68(3): 262-3, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23749019

RESUMEN

Chylous leakage after mastectomy & axillary clearance is a rare complication. The incidence is less than 0.5%. Anatomical variations in the termination of thoracic duct can occur, rendering it susceptible to injury during axillary dissection. Most chyle leaks in the axilla are managed through conservative measures. Surgical intervention is required in high output chylous leaks. We encountered a case of chylous leak post mastectomy with axillary clearance, which was successfully treated conservatively.


Asunto(s)
Axila , Mastectomía , Quilo , Humanos , Escisión del Ganglio Linfático , Complicaciones Posoperatorias/cirugía , Conducto Torácico
12.
J Interpers Violence ; 36(19-20): NP10345-NP10370, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-31524036

RESUMEN

Resilience is a key health protective factor for those with adverse childhood experiences (ACEs), but little research has explored how it manifests in early adulthood or across cultures. The purpose of this study was to generate a fuller understanding of resilience and its contribution to the relationships between mental health problems and ACEs among Chinese young adults in Hong Kong. Using a sequential explanatory mixed-methods design, 433 Chinese young adults aged 18 to 24 years were surveyed online to examine the relationships between ACEs, resilience, and mental health problems (depression, anxiety, maladjustment, and posttraumatic stress symptoms). Among them, 34 participants with ACEs were purposively selected and interviewed to explore cultural factors that influenced their resilience. Quantitative data were analyzed using multiple hierarchical regression analyses; qualitative data were analyzed using a qualitative descriptive approach. Higher cumulative ACE exposure was associated with higher severity of adjustment disorder and odds for screening positive for posttraumatic stress disorders, but not for symptoms of depression or anxiety. Resilience significantly contributed to explaining variances across all mental health outcomes over and beyond ACEs and in a protective fashion. Four themes emerged from qualitative interviews: (a) Privacy, emotional restraint, and "saving face"; (b) Conforming to preserve harmony; (c) A will to excel; and (d) Viewing adversity as a matter of luck. These findings suggest Chinese young adults' resilience was influenced by cultural norms of restraint, conformity, competition, and superstition. The present study provides a model for future studies using a mixed-methods design to deeply examine resilience among younger people exposed to early adversities within sociocultural, historical, or geographical contexts.


Asunto(s)
Experiencias Adversas de la Infancia , Trastornos por Estrés Postraumático , Adulto , Ansiedad/epidemiología , China , Humanos , Salud Mental , Adulto Joven
13.
J Exp Med ; 177(4): 1093-103, 1993 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-8459204

RESUMEN

A conserved sequence motif has been identified in a number of signaling subunits associated with hematopoietic cell antigen receptors. Here, we characterize signaling by a 17 amino acid motif that is triplicated in the T cell antigen receptor zeta chain. Analysis of zeta truncations and constructs containing the isolated motif demonstrates that this motif is sufficient for the induction of both proximal and distal events associated with T cell activation. Stimulation of truncations that contain either one, two, or three copies of the motif results in induction of an identical pattern of tyrosine phosphoproteins. Moreover, triplication of the NH2-terminal zeta motif results in enhanced signaling, suggesting a redundant role in signal amplification for the three motifs in zeta. Finally, we demonstrate the association of a recently identified protein tyrosine kinase ZAP-70 with this motif, and provide evidence for its involvement in zeta function.


Asunto(s)
Proteínas de la Membrana/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Transducción de Señal , Linfocitos T/metabolismo , Secuencia de Aminoácidos , Antígenos CD8/genética , Antígenos CD8/metabolismo , Línea Celular , Secuencia Conservada , Citometría de Flujo , Humanos , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Datos de Secuencia Molecular , Fragmentos de Péptidos/metabolismo , Pruebas de Precipitina , Proteínas Tirosina Quinasas/metabolismo , Receptores de Antígenos de Linfocitos T/química , Receptores de Antígenos de Linfocitos T/genética , Transfección , Proteína Tirosina Quinasa ZAP-70
14.
J Exp Med ; 194(3): 255-64, 2001 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-11489945

RESUMEN

In latently infected B lymphocytes, the Epstein-Barr virus (EBV) suppresses signal transduction from the antigen receptor through expression of the integral latent membrane protein 2A (LMP2A). At the same time, LMP2A triggers B cell survival by a yet uncharacterized maintenance signal that is normally provided by the antigen receptor. The molecular mechanisms are unknown as LMP2A-regulated signaling cascades have not been described so far. Using a novel mouse model we have identified the intracellular adaptor protein Src homology 2 (SH2) domain-containing leukocyte protein (SLP)-65 as a critical downstream effector of LMP2A in vivo. Biochemical analysis of the underlying signaling pathways revealed that EBV infection causes constitutive tyrosine phosphorylation of one of the two SLP-65 isoforms and complex formation between SLP-65 and the protooncoprotein CrkL (CT10 regulator of kinase like). This leads to antigen receptor-independent phosphorylation of Cbl (Casitas B lineage lymphoma) and C3G. In contrast, phospholipase C-gamma2 (PLC-gamma2) activation is completely blocked. Our data show that in order to establish a latent EBV infection, LMP2A selectively activates or represses SLP-65-regulated signaling pathways.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Proteínas Portadoras/metabolismo , Herpesvirus Humano 4/metabolismo , Fosfoproteínas/metabolismo , Proteínas de la Matriz Viral/metabolismo , Animales , Linfocitos B/inmunología , Linfocitos B/metabolismo , Linfocitos B/virología , Secuencia de Bases , Proteínas Portadoras/química , Proteínas Portadoras/genética , Línea Celular , Cartilla de ADN/genética , Inhibidores Enzimáticos/farmacología , Precursores Enzimáticos/química , Precursores Enzimáticos/metabolismo , Infecciones por Virus de Epstein-Barr/inmunología , Infecciones por Virus de Epstein-Barr/metabolismo , Infecciones por Virus de Epstein-Barr/virología , Femenino , Humanos , Peróxido de Hidrógeno/farmacología , Péptidos y Proteínas de Señalización Intracelular , Isoenzimas/metabolismo , Masculino , Ratones , Ratones Noqueados , Ratones Transgénicos , Proteínas Nucleares/metabolismo , Fosfolipasa C gamma , Fosfoproteínas/química , Fosfoproteínas/genética , Fosforilación , Proteínas Tirosina Fosfatasas/antagonistas & inhibidores , Proteínas Tirosina Quinasas/química , Proteínas Tirosina Quinasas/metabolismo , Transducción de Señal , Quinasa Syk , Fosfolipasas de Tipo C/metabolismo , Tirosina/química , Vanadatos/farmacología , Proteínas de la Matriz Viral/química , Proteínas de la Matriz Viral/genética
15.
J Exp Med ; 192(6): 847-56, 2000 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-10993915

RESUMEN

B cell linker protein (BLNK) and Src homology 2 domain-containing leukocyte protein of 76 kD (SLP-76) are adaptor proteins required for B cell receptor (BCR) and T cell receptor function, respectively. Here, we show that expression of SLP-76 cannot reconstitute BCR function in Zap-70(+)BLNK(-) B cells. This could be attributable to inability of SLP-76 to be recruited into glycolipid-enriched microdomains (GEMs) after antigen receptor cross-linking. Supporting this idea, the BCR function was restored when a membrane-associated SLP-76 chimera was enforcedly localized to GEMs. Moreover, we demonstrate that addition of both linker for activation of T cells (LAT) and Grb2-related adaptor downstream of Shc (Gads) to SLP-76 allow SLP-76 to be recruited into GEMs, whereby the BCR function is reconstituted. The Gads function was able to be replaced by overexpression of Grb2. In contrast to SLP-76, BLNK did not require Grb2 families for its recruitment to GEMs. Hence, these data suggest a functional overlap between BLNK and SLP-76, while emphasizing the difference in requirement for additional adaptor molecules in their targeting to GEMs.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Linfocitos B/inmunología , Proteínas Portadoras/metabolismo , Membrana Celular/inmunología , Proteínas de la Membrana , Fosfoproteínas/metabolismo , Proteínas/metabolismo , Receptores de Antígenos de Linfocitos B/inmunología , Animales , Proteínas Portadoras/inmunología , Pollos , Receptores ErbB/fisiología , Proteína Adaptadora GRB2 , Biblioteca de Genes , Humanos , Fosfoproteínas/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/metabolismo , Transducción de Señal
16.
J Exp Med ; 194(4): 507-18, 2001 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-11514606

RESUMEN

Engagement of the T cell antigen receptor (TCR) induces the transphosphorylation of the zeta chain-associated protein of 70,000 Mr (ZAP-70) protein tyrosine kinase (PTK) by the CD4/8 coreceptor associated Lck PTK. Phosphorylation of Tyr 493 within ZAP-70's activation loop results in the enzymatic activation of ZAP-70. Additional tyrosines (Tyrs) within ZAP-70 are phosphorylated that play both positive and negative regulatory roles in TCR function. Phosphorylation of Tyr residues (Tyrs 315 and 319) within the Interdomain B region of the ZAP-70 PTK plays important roles in the generation of second messengers after TCR engagement. Here, we demonstrate that phosphorylation of these two Tyr residues also play important roles in mediating the positive and negative selection of T cells in the thymus.


Asunto(s)
Receptores de Antígenos de Linfocitos T gamma-delta/química , Linfocitos T/citología , Tirosina/química , Animales , Ratones , Ratones Transgénicos , Receptores de Antígenos de Linfocitos T gamma-delta/fisiología
17.
Compr Child Adolesc Nurs ; 43(1): 48-64, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30640560

RESUMEN

In the absence of a mandatory reporting (MR) structure, it is unclear how nurses perceive or exercise their role in child protection. This study examined knowledge and perceptions of child protection and MR among nurses working in Hong Kong. This cross-sectional web-based survey used the Child Abuse Report Intention Scale to measure nurses' child protection knowledge and attitudes, and their perceived norms, control, and intention to report suspected maltreatment. Nurses also indicated if they support MR and to provide an explanation for their preference. Quantitative data were described and analyzed using bivariate and regression analyses. Open-ended responses were analyzed using directed content analysis. A convenient sample of 91 nurses working in Hong Kong completed the survey. The majority (86%) were female with a mean of 9.5 years of nursing experience; their mean knowledge score was 6.64 out of 13 (range 2-10). Compared with other maltreatment types, sexual abuse was perceived to be most severe and most likely to be reported. Perceived severity and attitudes toward child maltreatment was significantly associated with nurses' intention to report. Over half (58%) supported MR; those against MR expressed concerns about lack of support from management. Although nurses working in Hong Kong still hold polarized views about MR, findings point to the importance of creating a supportive reporting culture, and designing training programs that focus on changing perceptions about child protection in order to improve their tendency to report.


Asunto(s)
Conocimiento , Notificación Obligatoria/ética , Enfermeras y Enfermeros/psicología , Percepción , Adulto , Niño , Preescolar , Estudios Transversales , Femenino , Hong Kong , Humanos , Masculino , Enfermeras y Enfermeros/estadística & datos numéricos , Encuestas y Cuestionarios
18.
Clin Exp Immunol ; 156(2): 238-45, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19250277

RESUMEN

Natural killer T cells (NKT) are a regulatory subset of T lymphocytes whose frequency in peripheral blood is highly variable within the human population. Lower than normal NKT frequencies are associated with increased predisposition to a number of diseases, including type 1 diabetes and some forms of cancer, raising the possibility that an increased frequency may be protective. However, there is little or no understanding of how high NKT frequencies arise or, most importantly, whether the potential exists to boost and maintain NKT levels for therapeutic advantage. Here, we provide a detailed functional and phenotypic characterization of the NKT compartment of a human donor with NKT levels approximately 50 times greater than normal, including an analysis of NKT in her immediate family members. The study focuses upon the characteristics of this donor and her family, but demonstrates more broadly that the size and flexibility of the NKT niche is far greater than envisioned previously. This has important implications for understanding how the human NKT compartment is regulated, and supports the concept that the human NKT compartment might be expanded successfully for therapeutic benefit.


Asunto(s)
Diabetes Mellitus Tipo 1/inmunología , Células T Asesinas Naturales/inmunología , Adolescente , Autoinmunidad , Femenino , Citometría de Flujo , Humanos , Memoria Inmunológica , Interferón gamma/inmunología , Activación de Linfocitos , Recuento de Linfocitos , Riesgo , Linfocitos T/inmunología
19.
J Cell Biol ; 70(3): 685-91, 1976 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-821955

RESUMEN

Repair synthesis induced by 4-nitroquinoline-1-oxide (4NQO) in L6 myoblasts before and after cellular fusion was measured by [3H] thymidine incorporation into unreplicated DNA. The level of repair synthesis was reuced after the cells had fused into myotubes. The terminal addition of radioactive nucleotides into DNA strands occurred only to a minor extent, and the dilution of [3H] thymidine by intracellular nucleotide pools was shown not to be responsible for the observed difference in repair synthesis, Both the initial rate and the overall incorporation of [3H] thymidine were found to be 50% lower in the myotubes. 4NQO treatment of myoblasts and myotubes induced modifications in the DNA which were observed as single-strand breaks during alkaline sucrose sedimentation. After the myoblasts were allowed a post-treatment incubation, most of the single-strand breaks were not longer apparent. In contrast, a post-treatment incubation of myotubes did not change the extent of single-strand breakage seen. Both myoblasts and myotubes were equally effective in repairing single-strand breaks induced by X radiation. It would appear that when myoblasts fuse, a repair enzyme activity is lost, probably an endonuclease that recognizes one of the 4 NQO modifications of DNA. The result observed is a partial loss of repair synthetic ability and a complete loss of ability to remove the modification that appears as a single-strand break in alkali.


Asunto(s)
Diferenciación Celular , Reparación del ADN , ADN/biosíntesis , Músculos , 4-Nitroquinolina-1-Óxido , Fusión Celular , Línea Celular , ADN/efectos de la radiación , Cinética , Efectos de la Radiación , Timidina/metabolismo
20.
J Cell Biol ; 74(2): 365-70, 1977 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-407232

RESUMEN

Cultures of fibroblasts from newborn rats and successive subcultures of these cells were treated with 4-nitroquinoline-1-oxide to induce DNA repair. DNA from the cultures was examined by velocity sedimentation in alkaline sucrose gradients immediately after drug treatment and after a post-treatment incubation period of 3 h. Early passage cells were able to repair the damage that appeared as single strand breaks, however, by the seventh subculture this activity was not apparent. Measurements of repair synthesis showed a partial loss of this capacity with successive subculture. The results fit a model in which 4NQO causes two kinds of DNA modification, one of which is alkali labile and appears as a single-strand break. Both modifications are subject to excision repair, but each is recognized initially by a specific endonuclease. In the late passage cells, the endonuclease specific for the alkali labile modification is absent.


Asunto(s)
Técnicas de Cultivo , Reparación del ADN , ADN/biosíntesis , Fibroblastos/metabolismo , 4-Nitroquinolina-1-Óxido/farmacología , Animales , Fibroblastos/efectos de los fármacos , Ratas
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