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1.
J Asthma ; 58(2): 160-169, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-31638844

RESUMEN

Introduction: Asthma is a common childhood respiratory disorder characterized by wheeze, cough and respiratory distress responsive to bronchodilator therapy. Asthma severity can be determined by subjective, manual scoring systems such as the Pulmonary Score (PS). These systems require significant medical training and expertise to rate clinical findings such as wheeze characteristics, and work of breathing. In this study, we report the development of an objective method of assessing acute asthma severity based on the automated analysis of cough sounds.Methods: We collected a cough sound dataset from 224 children; 103 without acute asthma and 121 with acute asthma. Using this database coupled with clinical diagnoses and PS determined by a clinical panel, we developed a machine classifier algorithm to characterize the severity of airway constriction. The performance of our algorithm was then evaluated against the PS from a separate set of patients, independent of the training set.Results: The cough-only model discriminated no/mild disease (PS 0-1) from severe disease (PS 5,6) but required a modified respiratory rate calculation to separate very severe disease (PS > 6). Asymptomatic children (PS 0) were separated from moderate asthma (PS 2-4) by the cough-only model without the need for clinical inputs.Conclusions: The PS provides information in managing childhood asthma but is not readily usable by non-medical personnel. Our method offers an objective measurement of asthma severity which does not rely on clinician-dependent inputs. It holds potential for use in clinical settings including improving the performance of existing asthma-rating scales and in community-management programs.AbbreviationsAMaccessory muscleBIbreathing indexCIconfidence intervalFEV1forced expiratory volume in one secondLRlogistic regressionPEFRpeak expiratory flow ratePSpulmonary scoreRRrespiratory rateSDstandard deviationSEstandard errorWAWestern Australia.


Asunto(s)
Asma/fisiopatología , Tos/fisiopatología , Índice de Severidad de la Enfermedad , Factores de Edad , Algoritmos , Australia , Niño , Preescolar , Femenino , Humanos , Masculino , Estudios Prospectivos , Pruebas de Función Respiratoria , Ruidos Respiratorios
2.
Respir Res ; 20(1): 81, 2019 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-31167662

RESUMEN

BACKGROUND: The differential diagnosis of paediatric respiratory conditions is difficult and suboptimal. Existing diagnostic algorithms are associated with significant error rates, resulting in misdiagnoses, inappropriate use of antibiotics and unacceptable morbidity and mortality. Recent advances in acoustic engineering and artificial intelligence have shown promise in the identification of respiratory conditions based on sound analysis, reducing dependence on diagnostic support services and clinical expertise. We present the results of a diagnostic accuracy study for paediatric respiratory disease using an automated cough-sound analyser. METHODS: We recorded cough sounds in typical clinical environments and the first five coughs were used in analyses. Analyses were performed using cough data and up to five-symptom input derived from patient/parent-reported history. Comparison was made between the automated cough analyser diagnoses and consensus clinical diagnoses reached by a panel of paediatricians after review of hospital charts and all available investigations. RESULTS: A total of 585 subjects aged 29 days to 12 years were included for analysis. The Positive Percent and Negative Percent Agreement values between the automated analyser and the clinical reference were as follows: asthma (97, 91%); pneumonia (87, 85%); lower respiratory tract disease (83, 82%); croup (85, 82%); bronchiolitis (84, 81%). CONCLUSION: The results indicate that this technology has a role as a high-level diagnostic aid in the assessment of common childhood respiratory disorders. TRIAL REGISTRATION: Australian and New Zealand Clinical Trial Registry (retrospective) - ACTRN12618001521213 : 11.09.2018.


Asunto(s)
Algoritmos , Tos/diagnóstico , Tos/epidemiología , Trastornos Respiratorios/diagnóstico , Trastornos Respiratorios/epidemiología , Teléfono Inteligente , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Estudios Prospectivos , Australia Occidental/epidemiología
4.
Ann Acad Med Singap ; 53(3): 170-186, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38920244

RESUMEN

Introduction: Tuberculosis (TB) remains endemic in Singapore. Singapore's clinical practice guidelines for the management of tuberculosis were first published in 2016. Since then, there have been major new advances in the clinical management of TB, ranging from diagnostics to new drugs and treatment regimens. The National TB Programme convened a multidisciplinary panel to update guidelines for the clinical management of drug-susceptible TB infection and disease in Singapore, contextualising current evidence for local practice. Method: Following the ADAPTE framework, the panel systematically reviewed, scored and synthesised English-language national and international TB clinical guidelines published from 2016, adapting recommendations for a prioritised list of clinical decisions. For questions related to more recent advances, an additional primary literature review was conducted via a targeted search approach. A 2-round modified Delphi process was implemented to achieve consensus for each recommendation, with a final round of edits after consultation with external stakeholders. Results: Recommendations for 25 clinical questions spanning screening, diagnosis, selection of drug regimen, monitoring and follow-up of TB infection and disease were formulated. The availability of results from recent clinical trials led to the inclusion of shorter treatment regimens for TB infection and disease, as well as consensus positions on the role of newer technologies, such as computer-aided detection-artificial intelligence products for radiological screening of TB disease, next-generation sequencing for drug-susceptibility testing, and video observation of treatment. Conclusion: The panel updated recommendations on the management of drug-susceptible TB infection and disease in Singapore.


Asunto(s)
Antituberculosos , Técnica Delphi , Tuberculosis Pulmonar , Tuberculosis , Humanos , Singapur , Antituberculosos/uso terapéutico , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/diagnóstico , Tuberculosis/tratamiento farmacológico , Tuberculosis/diagnóstico , Consenso
5.
Bioengineering (Basel) ; 10(8)2023 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-37627823

RESUMEN

This work demonstrated the feasibility of an industrial-scale aerated static pile composting system for treating one of the common biowastes-soybean curd residue. The mixing ratios of the feedstock were optimized to achieve a carbon-nitrogen ratio and a moisture level in the ranges of 25-35 and 60-70%, respectively. This open-air composting system required 6-7 months to obtain a mature compost. Solvita and seed germination tests further confirmed the maturity of the compost, with 25% compost extract concentration yielding the best germination index in the absence of phytotoxicity. The bacterial and fungal compositions of the compost piles were further examined with metagenomic analysis. Thermoactinomyces spp., Oceanobacillus spp., and Kroppenstedtia spp. were among the unique bacteria found, and Diutina rugosa, Thermomyces dupontii, and Candida taylorii were among the unique fungi found in the compost piles, suggesting the presence of good microorganisms for degrading the organic biowastes.

6.
Nat Commun ; 14(1): 906, 2023 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-36810735

RESUMEN

Osteoclasts are giant bone-digesting cells that harbor specialized lysosome-related organelles termed secretory lysosomes (SLs). SLs store cathepsin K and serve as a membrane precursor to the ruffled border, the osteoclast's 'resorptive apparatus'. Yet, the molecular composition and spatiotemporal organization of SLs remains incompletely understood. Here, using organelle-resolution proteomics, we identify member a2 of the solute carrier 37 family (Slc37a2) as a SL sugar transporter. We demonstrate in mice that Slc37a2 localizes to the SL limiting membrane and that these organelles adopt a hitherto unnoticed but dynamic tubular network in living osteoclasts that is required for bone digestion. Accordingly, mice lacking Slc37a2 accrue high bone mass owing to uncoupled bone metabolism and disturbances in SL export of monosaccharide sugars, a prerequisite for SL delivery to the bone-lining osteoclast plasma membrane. Thus, Slc37a2 is a physiological component of the osteoclast's unique secretory organelle and a potential therapeutic target for metabolic bone diseases.


Asunto(s)
Resorción Ósea , Osteoclastos , Ratones , Animales , Osteoclastos/metabolismo , Transporte Biológico , Lisosomas/metabolismo , Huesos/metabolismo , Membrana Celular/metabolismo , Resorción Ósea/metabolismo
7.
Front Pediatr ; 9: 736018, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34869099

RESUMEN

Background: Diagnostic errors are a global health priority and a common cause of preventable harm. There is limited data available for the prevalence of misdiagnosis in pediatric acute-care settings. Respiratory illnesses, which are particularly challenging to diagnose, are the most frequent reason for presentation to pediatric emergency departments. Objective: To evaluate the diagnostic accuracy of emergency department clinicians in diagnosing acute childhood respiratory diseases, as compared with expert panel consensus (reference standard). Methods: Prospective, multicenter, single-blinded, diagnostic accuracy study in two well-resourced pediatric emergency departments in a large Australian city. Between September 2016 and August 2018, a convenience sample of children aged 29 days to 12 years who presented with respiratory symptoms was enrolled. The emergency department discharge diagnoses were reported by clinicians based upon standard clinical diagnostic definitions. These diagnoses were compared against consensus diagnoses given by an expert panel of pediatric specialists using standardized disease definitions after they reviewed all medical records. Results: For 620 participants, the sensitivity and specificity (%, [95% CI]) of the emergency department compared with the expert panel diagnoses were generally poor: isolated upper respiratory tract disease (64.9 [54.6, 74.4], 91.0 [88.2, 93.3]), croup (76.8 [66.2, 85.4], 97.9 [96.2, 98.9]), lower respiratory tract disease (86.6 [83.1, 89.6], 92.9 [87.6, 96.4]), bronchiolitis (66.9 [58.6, 74.5], 94.3 [80.8, 99.3]), asthma/reactive airway disease (91.0 [85.8, 94.8], 93.0 [90.1, 95.3]), clinical pneumonia (63·9 [50.6, 75·8], 95·0 [92·8, 96·7]), focal (consolidative) pneumonia (54·8 [38·7, 70·2], 86.2 [79.3, 91.5]). Only 59% of chest x-rays with consolidation were correctly identified. Between 6.9 and 14.5% of children were inappropriately prescribed based on their eventual diagnosis. Conclusion: In well-resourced emergency departments, we have identified a previously unrecognized high diagnostic error rate for acute childhood respiratory disorders, particularly in pneumonia and bronchiolitis. These errors lead to the potential of avoidable harm and the administration of inappropriate treatment.

8.
Mol Endocrinol ; 23(1): 35-46, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19008464

RESUMEN

Receptor activator of nuclear factor-kappaB ligand (RANKL) is a key factor necessary for osteoclast differentiation and activation. Mutations within the TNF-like core domain of RANKL have been recently reported in patients with osteoclast-poor autosomal recessive osteopetrosis. However, the functional consequence owing to RANKL mutations has not been well characterized. Here we describe the functional propensity of RANKL mutants in osteoclast differentiation and their impact on RANKL-mediated signaling cascades. Recombinant RANKL (rRANKL) mutants within the TNF-like core domain exhibited diminished osteoclastogenic potential as compared with wild-type rRANKL1 encoding the full TNF-like core domain [amino acids (aa) 160-318]. Consistent with the insufficient activities on osteoclastogenesis, rRANKL mutants showed reduced activation of nuclear factor-kappaB, IkappaBalpha degradation, and ERK phosphorylation. In addition, we found that rRANKL mutants interfered with wild-type rRANKL-induced osteoclastogenesis with deletion mutant rRANKL5 (aa 246-318) exhibiting the greatest inhibitory effect. The same mutant also significantly reduced wild-type rRANKL1 (aa 160-318)-induced osteoclastic bone resorption in vitro. BIAcore assays demonstrated that rRANKL5 alone, lacking the AA'' and CD loops, weakly binds to receptor activator of nuclear factor-kappaB (RANK). Intriguingly, preincubation of mutant rRANKL5 with rRANKL1 before exposure to RANK enhanced the maximal binding level to RANK, indicating that rRANKL5 forms hybrid trimeric complexes with rRANKL1. Furthermore, RANKL mutant mimicking human RANKL V277 mutation in patients, impairs osteoclast differentiation and signaling. Taken together, these data lend support to the notion that the TNF-like core domain of RANKL contains structural determinants that are crucial for osteoclast differentiation and activation, thus providing a possible mechanistic explanation for the observed phenotype in osteopetrotic patients harboring RANKL mutations.


Asunto(s)
Osteoclastos/citología , Osteoclastos/fisiología , Ligando RANK/química , Ligando RANK/fisiología , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Secuencia de Bases , Resorción Ósea/genética , Resorción Ósea/fisiopatología , Diferenciación Celular , Línea Celular , Cartilla de ADN/genética , Humanos , Proteínas I-kappa B/fisiología , Técnicas In Vitro , Sistema de Señalización de MAP Quinasas , Ratones , Modelos Moleculares , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Inhibidor NF-kappaB alfa , FN-kappa B/fisiología , Osteopetrosis/genética , Estructura Terciaria de Proteína , Ligando RANK/genética , Ratas , Ratas Wistar , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Eliminación de Secuencia , Transducción de Señal
9.
Rev Environ Health ; 35(3): 281-293, 2020 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-32853171

RESUMEN

Objectives Non-communicable diseases (NCDs) pose the greatest threat to human health globally. The dramatic rise in early onset NCDs - such as childhood obesity, the allergy epidemic and an increasing burden of mental ill health in children and youth - reflect the profound early impact of modern environments on developing systems. The ORIGINS Project is a research platform enabling world class investigation of early antecedent pathways to NCDs, and how to curtail these. As well as facilitating strategic long-term research capacity, ORIGINS is a pipeline for short-term productivity through a series of clinical trials, early interventions, mechanistic studies, and targeted research questions to improve maternal and paternal health and the early environment. Methods ORIGINS is a decade-long collaborative initiative between the Joondalup Health Campus (JHC) and the Telethon Kids Institute (TKI) to establish a Western Australian (WA) birth cohort of 10,000 families, enrolled during pregnancy. It is currently funded to follow up participating children and their families to five years of age. Comprehensive data and biological samples are collected from participants at up to 15 different timepoints, from the first antenatal clinic visit. In the process, ORIGINS is creating a major research platform, consisting of an extensive, world class biobank and databank. Of key strength and novelty, ORIGINS includes a series of harmonised nested sub-projects integrated with clinical and diagnostic services and providing real-time feedback to improve the health of individuals and the community. Conclusions At its core, ORIGINS aims to improve the health and quality of life of the next generation through improved pathways to optimise the early environment and reduce adversity by promoting primary prevention, early detection and early intervention. This dynamic, interactive, community-based project not only provides novel research capacity, productivity, collaboration and translational impact on future generations - it is also anticipated to have flow on benefits for community engagement, cohesion and purpose. This will provide a sentinel example for tailored replication in other communities around the world as part of interconnected grass root strategies to improve planetary health.


Asunto(s)
Salud Ambiental , Calidad de Vida , Preescolar , Estudios de Cohortes , Humanos , Lactante , Recién Nacido , Australia Occidental
10.
J Paediatr Child Health ; 45(12): 715-9, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19863711

RESUMEN

BACKGROUND: To guide the development of adolescent health training and the planning of future services, accurate data describing health service use by adolescents and young adults are needed. AIM: To describe admission rates for adolescents (12-17 years) and young adults (age 18 years and over) attending a specialist children's hospital over an 8-year period. Specific objectives were to describe the (i) proportion of adolescents and young adults admitted under different specialties; (ii) age range, with emphasis on those 18 years and over; and (iii) proportion of patients admitted to the general adolescent ward. METHODS: Data on adolescent and young adult admissions to Princess Margaret Hospital (PMH) were collected prospectively from July 2000 to June 2008. RESULTS: Adolescents and young adults accounted for one fifth (range 18-22%) of all admissions to PMH. Over the 8-year period, the number of adolescent and young adult admissions increased from 3935 (54% males) to 4967 (56% males) per year. The proportion admitted to the general adolescent ward ranged from 22% to 36%. The three specialties admitting the most adolescents and young adults were General Surgery (11-13%), Orthopaedics (11-13%) and Oncology/Haematology (10-14%). The age range was: 12-14 years (57-67%); 15-17 (30-39%); 18+ (2-5%). At least 15 patients aged 20 or over were admitted each year, mostly for Dental or Plastic Surgery. CONCLUSIONS: Adolescent and young adult health is part of the core business of paediatrics. This should be reflected in the planning of future paediatric services. All trainees require some basic training, regardless of heir specialty area.


Asunto(s)
Hospitalización/tendencias , Hospitales Pediátricos , Adolescente , Niño , Humanos , Estudios Prospectivos , Australia Occidental , Adulto Joven
11.
Artículo en Inglés | MEDLINE | ID: mdl-30792854

RESUMEN

Background: Healthcare-associated infections (HAIs) and antimicrobial resistance (AMR) affect patients in acute-care hospitals worldwide. No systematic review has been published on adoption and implementation of the infection prevention and control (IPC) key components. The objective of this systematic review was to assess adoption and implementation of the three areas issued by the "National Health Commission of the People's Republic of China" in acute-care hospitals in Mainland China, and to compare the findings with the key and core components on effective IPC, issued by the European Centre for Disease Prevention and Control (ECDC) and the World Health Organization (WHO). Methods: We searched PubMed and the Chinese National Knowledge Infrastructure for reports on the areas "structure, organisation and management of IPC", "education and training in IPC", and "surveillance of outcome and process indicators in IPC" in acute-care facilities in Mainland China, published between January 2012 and October 2017. Results were stratified into primary care hospitals and secondary/tertiary care hospitals. Results: A total of 6580 publications were retrieved, of which 56 were eligible for final analysis. Most of them were survey reports (n = 27), followed by observational studies (n = 17), and interventional studies (n = 12), either on hand hygiene promotion and best practice interventions (n = 7), or by applying education and training programmes (n = 5). More elements on IPC were reported by secondary/tertiary care hospitals than by primary care hospitals. Gaps were identified in the lack of detailing on organisation and management of IPC, education and training activities, and targets of surveillance such as central line-associated bloodstream infections, ventilator associated pneumonia, catheter-associated urinary tract infections, and Clostridium difficile infections. Information was available on adoption and implementation of 7 out of the 10 ECDC key components, and 7 out of the 8 WHO core components. Conclusion: To variable degrees, there is evidence on implementation of all NHCPRC areas and of most of the ECDC key components and the WHO core components in acute care hospitals in Mainland China. The results are encouraging, but gaps in effective IPC were identified that may be used to guide future national policy-making in Mainland China.


Asunto(s)
Infecciones Bacterianas/prevención & control , Infección Hospitalaria/prevención & control , Bacterias/clasificación , Bacterias/efectos de los fármacos , Bacterias/genética , Bacterias/aislamiento & purificación , Infecciones Bacterianas/epidemiología , Infecciones Bacterianas/microbiología , China/epidemiología , Cuidados Críticos/estadística & datos numéricos , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Farmacorresistencia Bacteriana , Higiene de las Manos , Humanos , Control de Infecciones
14.
Case Rep Infect Dis ; 2018: 3820513, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30073100

RESUMEN

Peritonitis is a common and serious complication of peritoneal dialysis (PD) with significant morbidity. We report the first case of relapsing Dokdonella koreensis peritonitis in a patient on peritoneal dialysis. A 63-year-old Chinese man, with history of renal failure on continuous ambulatory peritoneal dialysis, presented with cloudy peritoneal effluent and abdominal pain. There was no sign or symptom suggestive of exit-site/tunnel tract infection. Peritoneal effluent cultures yielded Dokdonella koreensis which was initially misidentified as Weeksella virosa and Brevundimonas species by the API® 20 NE and VITEK® 2 GN ID card, respectively. He was treated with intraperitoneal amikacin, but the infection relapsed within a few days upon completing each antibiotic course. He eventually required removal of catheter and was transferred to hemodialysis. Infections due to unusual organisms may pose a diagnostic issue as currently available commercial tests will not be able to identify them. There is a role for using 16S rRNA sequencing to help identify these organisms and guide patient management.

15.
JMM Case Rep ; 3(5): e005068, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28348790

RESUMEN

INTRODUCTION: Invasive pneumococcal disease is an uncommon and notifiable disease in Singapore. It is often associated with significant morbidity and mortality. We report a rare case of invasive pneumococcal bacteraemia due to parotitis in a patient with systemic sclerosis and secondary Sjögren's syndrome. We also present a retrospective review of Streptococcus pneumoniae bacteraemia cases in Singapore General Hospital from January 2011 to April 2016. CASE PRESENTATION: A 59-year-old Malay lady with a history of systemic sclerosis with secondary Sjögren's syndrome presented with fever and left parotid gland swelling. Clinical examination revealed poor salivary pooling and left parotid swelling without fluctuance. Ultrasound of the left parotid gland confirmed acute parotitis without evidence of abscess or sialolithiasis. Blood cultures were positive for S. pneumoniae. She was diagnosed to have invasive pneumococcal bacteraemia secondary to acute parotitis, and treated with intravenous benzylpenicillin with clearance of bacteraemia after 3 days. Upon discharge, her antibiotics were changed to intravenous ceftriaxone to facilitate outpatient parenteral antibiotic therapy for another 2 weeks. She responded favourably to antibiotics at follow-up, with no complications from the bacteraemia. A review of the microbiological records of the Singapore General Hospital revealed 116 cases of pneumococcal bacteraemia, most (80.3 %) of which were due to pneumonia. None were due to parotitis. CONCLUSION: S. pneumoniae parotitis and subsequent bacteraemia is rare. Prompt recognition of the disease and appropriate use of antibiotics are important. This case highlights that close communication between healthcare workers (microbiologist, rheumatologist and infectious disease specialist) is essential in ensuring good clinical outcomes in patients with a potentially fatal disease.

16.
J Invest Dermatol ; 127(4): 915-24, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17068476

RESUMEN

The mechanisms by which erythemal UVB irradiation modulates systemic immune responses to antigens applied to non-irradiated sites are poorly understood. In this study, regulatory CD4+ T cells were identified in the skin-draining lymph nodes (SDLNs) of UVB-irradiated, but otherwise naive mice. A transgenic mouse strain (DO11.10) was utilized in which the majority of CD4+ T cells expressed the ovalbumin (OVA(323-339)) T-cell receptor. Thus, T-cell responses could be examined following erythemal UVB irradiation without further antigen sensitization. CD4+ T cells from the SDLNs of UVB-irradiated mice had significantly reduced capacity to respond to presentation of the OVA(323-339) peptide in vitro. Transfer of CD4+ T cells from the SDLNs of UVB-irradiated antigen-naive mice significantly reduced both OVA sensitization and contact hypersensitivity responses to an experimental hapten in the recipient mice. Depletion of CD4+CD25+ cells abrogated this UVB-suppressive effect in the in vitro proliferation assay. There was also a significant increase in the proportion of CD4+CD25+Foxp3+ cells in the SDLNs of UVB-irradiated mice. The potential of these regulatory cells poised to regulate responses to incoming antigens at distant non-irradiated sites broadens the biological impact of UVB irradiation of skin on immunity.


Asunto(s)
Formación de Anticuerpos/fisiología , Antígenos/inmunología , Linfocitos T CD4-Positivos/fisiología , Linfocitos T CD4-Positivos/efectos de la radiación , Ganglios Linfáticos/citología , Rayos Ultravioleta , Animales , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/metabolismo , Proliferación Celular , Células Cultivadas , Dermatitis por Contacto/prevención & control , Relación Dosis-Respuesta en la Radiación , Factores de Transcripción Forkhead/metabolismo , Inmunización , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Transgénicos , Ovalbúmina/genética , Ovalbúmina/inmunología , Ovalbúmina/metabolismo , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/inmunología , Fragmentos de Péptidos/metabolismo , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/metabolismo , Factores de Tiempo
17.
J Cell Physiol ; 212(3): 787-95, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17477372

RESUMEN

Calcium/calmodulin-dependent protein kinase (CaMK) is a major down stream mediator of Ca(2+) signaling in a wide range of cellular functions, including ion channel and cell cycle regulation and neurotransmitter synthesis and release. Here we have investigated the role of the CaMK signaling pathway in osteoclast differentiation and bone resorption. We observed that the CaMKI, CaMKII gamma isoforms were present in both bone-marrow derived macrophages and RAW264.7 murine macrophage cell line, and that expression persisted during osteoclast differentiation in the presence of receptor activator of nuclear factor kappa B (NF-kappaB) ligand (RANKL). RANKL-induced differentiation was accompanied by increased cyclic AMP response element transcriptional activity, and ERK phosphorylation, which are both downstream targets of CaMK. Two selective inhibitors of CaMKs, KN-93 and KN-62, inhibited osteoclastogenesis in a time and concentration-dependent manner. This was accompanied by suppression of cathepsin K expression and osteoclastic bone resorption, which are markers for differentiated osteoclast function. KN-93 and KN-62 both inhibited RANKL-induced ERK phosphorylation and CREB transcriptional activity. These findings imply a role for CaMK in osteoclast differentiation and bone resorption.


Asunto(s)
Resorción Ósea/metabolismo , Señalización del Calcio , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Diferenciación Celular , Macrófagos/metabolismo , Osteoclastos/metabolismo , Ligando RANK/metabolismo , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/análogos & derivados , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/farmacología , Animales , Bencilaminas/farmacología , Resorción Ósea/enzimología , Resorción Ósea/genética , Resorción Ósea/prevención & control , Señalización del Calcio/efectos de los fármacos , Proteína Quinasa Tipo 1 Dependiente de Calcio Calmodulina , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina , Proteínas Quinasas Dependientes de Calcio-Calmodulina/antagonistas & inhibidores , Proteínas Quinasas Dependientes de Calcio-Calmodulina/genética , Catepsina K , Catepsinas/genética , Catepsinas/metabolismo , Diferenciación Celular/efectos de los fármacos , Línea Celular , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Relación Dosis-Respuesta a Droga , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Regulación Enzimológica de la Expresión Génica , Macrófagos/efectos de los fármacos , Macrófagos/enzimología , Ratones , Ratones Endogámicos C57BL , Osteoclastos/efectos de los fármacos , Osteoclastos/enzimología , Fosforilación , Inhibidores de Proteínas Quinasas/farmacología , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Sulfonamidas/farmacología , Factores de Tiempo , Transcripción Genética , Transfección
18.
J Immunol ; 178(5): 2794-802, 2007 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-17312123

RESUMEN

Exposure of skin to UVB radiation (290-320 nm) modulates the immune system, with most studies showing a suppression of Th1-driven immune responses. This study investigated the effects of UVB on Th2-associated immune responses using a murine model of allergic respiratory inflammation. C57BL/6, histamine receptor-1 knockout (H1RKO), and histamine receptor-2 knockout (H2RKO) mice were exposed to a single 4 kJ/m(2) dose of UVB (twice a minimal edemal dose) on shaved dorsal skin 3 days before intranasal sensitization with papain, a cysteine protease homologue of the dust mite allergen Der p 1. H1RKO mice demonstrated enhanced papain-specific inflammatory responses in the lung-draining lymph nodes (LDLNs), whereas the responses of H2RKO mice closely mimicked those of C57BL/6 mice. UVB irradiation 3 days before sensitization reduced in vitro papain-specific proliferation of LDLN cells of C57BL/6 and H1RKO mice but not H2RKO mice 24 h after challenge. The regulatory effect of UVB was transferred by adoptive transfer of unfractionated LDLN cells from UVB-irradiated, papain-sensitized C57BL/6 and H1RKO donor mice in naive recipients of the corresponding strain that were subsequently sensitized and challenged with papain. Additionally, UVB exposure suppressed papain-induced IL-5 and IL-10 production in vitro by LDLN cells from H1RKO mice but not from C57BL/6 mice or H2RKO mice. The results of this study demonstrate systemic immunomodulation of responses to intranasally delivered Ag by UVB irradiation and implicate a role for the H2 receptor in UVB-induced suppression of Ag-specific responses in the draining lymph nodes.


Asunto(s)
Antígenos Dermatofagoides/inmunología , Hipersensibilidad/inmunología , Tolerancia Inmunológica/efectos de la radiación , Receptores Histamínicos/inmunología , Rayos Ultravioleta , Administración Intranasal , Traslado Adoptivo , Animales , Proteínas de Artrópodos , Cisteína Endopeptidasas , Femenino , Hipersensibilidad/prevención & control , Inflamación/inmunología , Inflamación/prevención & control , Ganglios Linfáticos/inmunología , Masculino , Ratones , Ratones Noqueados , Papaína/inmunología , Papaína/farmacología , Ratas , Ratas Sprague-Dawley , Receptores Histamínicos/deficiencia
19.
J Immunol ; 174(11): 6677-85, 2005 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-15905507

RESUMEN

UVB irradiation of the shaved dorsal skin of mice can cause both local and systemic suppression of contact hypersensitivity responses; the former demonstrated by administration of the sensitizing Ag/hapten to the irradiated site and the latter by its administration at least 72 h later to distal unirradiated sites. The immunological basis of systemic immunomodulation is not clear. When haptens (trinitrochlorobenzene, FITC) were administered to the shaved ventral skin 4 days after irradiation (8 kJ/m(2)) to the shaved dorsum of BALB/c mice, CD11c(+)/FITC(+) cells in the skin-draining lymph nodes from control and irradiated mice produced on a per cell basis similar levels of IL-12 and PGE(2) were phenotypically mature and efficient at presenting FITC to lymphocytes from FITC-sensitized mice. Ag presentation by FACS-sorted CD11c(+) lymph node cells isolated 4 days after UVB irradiation was as efficient as were cells from unirradiated mice at presentation in vitro of an OVA peptide (OVA(323-339)) to CD4(+) cells from OVA-TCR-transgenic DO11.10 mice. Further, IFN-gamma levels were increased in the cultures containing CD11c(+) cells from UVB-irradiated mice, suggesting that inflammation may precede downstream immunosuppression. These results suggest that the primary cause of reduced contact hypersensitivity responses in mice in which UV irradiation and the sensitizing Ag are applied to different sites several days apart must originate from cells other than CD11c(+) APCs that directly or by production of soluble mediators (IL-12, PGE(2)) affect cellular responses in the nodes of UVB-irradiated mice.


Asunto(s)
Células Presentadoras de Antígenos/inmunología , Células Presentadoras de Antígenos/efectos de la radiación , Diferenciación Celular/inmunología , Diferenciación Celular/efectos de la radiación , Factores Inmunológicos/biosíntesis , Factores Inmunológicos/efectos de la radiación , Ganglios Linfáticos/inmunología , Rayos Ultravioleta , Administración Tópica , Secuencia de Aminoácidos , Animales , Presentación de Antígeno/efectos de la radiación , Células Presentadoras de Antígenos/patología , Antígeno CD11c/biosíntesis , Movimiento Celular/inmunología , Movimiento Celular/efectos de la radiación , Técnicas de Cocultivo , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Células Dendríticas/efectos de la radiación , Dermatitis por Contacto/inmunología , Dermatitis por Contacto/patología , Dinoprostona/biosíntesis , Dinoprostona/fisiología , Dinoprostona/efectos de la radiación , Femenino , Fluoresceína-5-Isotiocianato/administración & dosificación , Fluoresceína-5-Isotiocianato/metabolismo , Fluoresceína-5-Isotiocianato/efectos de la radiación , Haptenos/administración & dosificación , Haptenos/biosíntesis , Haptenos/efectos de la radiación , Factores Inmunológicos/fisiología , Interleucina-12/biosíntesis , Interleucina-12/fisiología , Interleucina-12/efectos de la radiación , Ganglios Linfáticos/citología , Ganglios Linfáticos/patología , Ratones , Ratones Endogámicos BALB C , Ratones Transgénicos , Datos de Secuencia Molecular , Cloruro de Picrilo/administración & dosificación , Cloruro de Picrilo/inmunología , Piel/inmunología , Piel/patología , Piel/efectos de la radiación
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