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BACKGROUND: With addiction rates and opioid deaths increasing, health care providers are obligated to help stem the opioid crisis. As limited studies examine the comparative effectiveness of fixed-dose combination nonopioid analgesia to opioid-containing analgesia, a comparative effectiveness study was planned and refined by conducting a pilot study. METHODS: The Opioid Analgesic Reduction Study (OARS) pilot, a stratified, randomized, multisite, double-blind clinical trial, was designed to test technology and procedures to be used in the full OARS trial. Participants engaged in the full protocol, enabling the collection of OARS outcome data. Eligible participants reporting to 1 of 5 sites for partial or full bony impacted mandibular third molar extraction were stratified by biologic sex and randomized to 1 of 2 treatment groups, OPIOID or NONOPIOID. OPIOID participants were provided 20 doses of hydrocodone 5 mg/acetaminophen 300 mg. NONOPIOID participants were provided 20 doses of ibuprofen 400 mg/acetaminophen 500 mg. OARS outcomes data, including pain experience, adverse effects, sleep quality, pain interference, overall satisfaction, and remaining opioid tablets available for diversion, were collected via surveys, electronic medication bottles, eDiary, and activity/sleep monitor. RESULTS: Fifty-three participants were randomized with 50 completing the OARS pilot protocol. Across all outcome pain domains, in all but 1 time period, NONOPIOID was better in managing pain than OPIOID (P < 0.05 level). Other outcomes suggest less pain interference, less adverse events, better sleep quality, better overall satisfaction, and fewer opioid-containing tablets available for diversion. DISCUSSION: Results suggest patients requiring impacted mandibular third molar extraction would benefit from fixed-dose combination nonopioid analgesia. KNOWLEDGE TRANSFER STATEMENT: Study results suggest fixed-dose nonopioid combination ibuprofen 400 mg/acetaminophen 500 mg is superior to opioid-containing analgesic (hydrocodone 5 mg/acetaminophen 500 mg). This knowledge should inform surgeons and patients in the selection of postsurgical analgesia.
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Analgésicos no Narcóticos , Analgésicos Opioides , Humanos , Analgésicos Opioides/uso terapéutico , Analgésicos Opioides/efectos adversos , Acetaminofén/uso terapéutico , Acetaminofén/efectos adversos , Ibuprofeno/uso terapéutico , Ibuprofeno/efectos adversos , Hidrocodona/efectos adversos , Proyectos Piloto , Combinación de Medicamentos , Analgésicos no Narcóticos/uso terapéutico , Analgésicos no Narcóticos/efectos adversos , Dolor/inducido químicamente , Dolor/tratamiento farmacológico , Método Doble CiegoRESUMEN
OBJECTIVES: To estimate the association between safety perception on vaccine acceptance and adoptions of risk mitigation strategies among dental health care workers (DHCWs). METHODS: A survey was emailed to DHCWs in the New Jersey area from December 2020 to January 2021. Perceived safety from regular SARS-CoV-2 testing of self, coworkers, and patients and its association with vaccine hesitancy and risk mitigation were ascertained. Risk Mitigation Strategy (RiMS) scores were computed from groupings of office measures: 1) physical distancing (reduced occupancy, traffic flow, donning of masks, minimal room crowding), 2) personal protective equipment (fitted for N95; donning N95 masks; use of face shields; coverings for head, body, and feet), and 3) environmental disinfection (suction, air filtration, ultraviolet, surface wiping). RESULTS: SARS-CoV-2 testing of dental professionals, coworkers, and patients were perceived to provide safety at 49%, 55%, and 68%, respectively. While dentists were least likely to feel safe with regular self-testing for SARS-CoV-2 (P < 0.001) as compared with hygienists and assistants, they were more willing than hygienists (P = 0.004; odds ratio, 1.79 [95% CI, 1.21 to 2.66]) and assistants (P < 0.001; odds ratio, 3.32 [95% CI, 1.93 to 5.71]) to receive the vaccine. RiMS scores ranged from 0 to 19 for 467 participants (mean [SD], 10.9 [2.9]). RiMS scores did not significantly differ among groups of DHCWs; however, mean RiMS scores were higher among those who received or planned to receive the COVID-19 vaccine than those with who did not (P = 0.004). DHCWs who felt safer with regular testing had greater RiMS scores than those who did not (11.0 vs. 10.3, P = 0.01). CONCLUSIONS: Understanding DHCWs' perception of risk and safety is crucial, as it likely influences attitudes toward testing and implementation of office risk mitigation policies. Clinical studies that correlate risk perception and RiMS with SARS-CoV-2 testing are needed to demonstrate the effectiveness of RiMS in dental care settings. KNOWLEDGE TRANSFER STATEMENT: Educators, clinicians, and policy makers can use the results of this study when improving attitudes toward testing and implementation of risk mitigation policies within dental offices, for current and future pandemics.
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COVID-19 , SARS-CoV-2 , Humanos , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19 , Prueba de COVID-19 , Atención a la Salud , PercepciónRESUMEN
AIMS: Gulf War Illness (GWI), a chronic debilitating disorder characterized by fatigue, joint pain, cognitive, gastrointestinal, respiratory, and skin problems, is currently diagnosed by self-reported symptoms. The Boston Biorepository, Recruitment, and Integrative Network (BBRAIN) is the collaborative effort of expert Gulf War Illness (GWI) researchers who are creating objective diagnostic and pathobiological markers and recommend common data elements for GWI research. MAIN METHODS: BBRAIN is recruiting 300 GWI cases and 200 GW veteran controls for the prospective study. Key data and biological samples from prior GWI studies are being merged and combined into retrospective datasets. They will be made available for data mining by the BBRAIN network and the GWI research community. Prospective questionnaire data include general health and chronic symptoms, demographics, measures of pain, fatigue, medical conditions, deployment and exposure histories. Available repository biospecimens include blood, plasma, serum, saliva, stool, urine, human induced pluripotent stem cells and cerebrospinal fluid. KEY FINDINGS: To date, multiple datasets have been merged and combined from 15 participating study sites. These data and samples have been collated and an online request form for repository requests as well as recommended common data elements have been created. Data and biospecimen sample requests are reviewed by the BBRAIN steering committee members for approval as they are received. SIGNIFICANCE: The BBRAIN repository network serves as a much needed resource for GWI researchers to utilize for identification and validation of objective diagnostic and pathobiological markers of the illness.
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Síndrome del Golfo Pérsico/patología , Boston , Humanos , Difusión de la Información , Imagen por Resonancia Magnética , Síndrome del Golfo Pérsico/sangre , Tomografía de Emisión de Positrones , Saliva/metabolismoRESUMEN
BACKGROUND: Brain metastases are frequent in HER2-positive breast cancer. ONT-380 (tucatinib) is a potent selective inhibitor of HER2 with intracranial activity in preclinical models. PATIENTS AND METHODS: This was a phase I study of tucatinib with trastuzumab, without chemotherapy, in patients with progressive, measurable HER2-positive brain metastases. The study tested two schedules of tucatinib: cohort A was twice daily and cohort B was once daily. The primary objective was determination of the maximum tolerated dose (MTD). Secondary end points included objective response (intracranial and extracranial) using modified RECIST and clinical benefit rate (CBR). RESULTS: Overall, 41 patients were enrolled (cohort A, n = 22; cohort B, n = 19). Patients had a median of two prior treatments for metastatic breast cancer and 83% had progressed after prior brain radiation. The MTD of tucatinib for cohort A was 300 mg twice daily and for cohort B was 750 mg once daily. The most common dose-limiting toxicities included thrombocytopenia and aspartate transaminase/alanine aminotransferase elevation. Grade 3/4 aspartate transaminase/alanine aminotransferase elevation occurred in nine of 41 patients (22%). Intracranial responses were observed in two of 17 (12%) patients in cohort A and one of 17 (6%) patients in cohort B treated at the MTD. In cohort A, CBR at 16 weeks was 35% (n = 6). In cohort B, CBR at 16 weeks was 53% (n = 9). Of 15 patients overall who experienced clinical benefit, 12 (80%) had received prior neratinib and/or lapatinib. Median progression-free survival for cohorts A and B was 3.4 and 4.1 months, respectively. CONCLUSION: The combination of tucatinib and trastuzumab is tolerable and demonstrated preliminary evidence of efficacy in patients with HER2-positive brain metastases. CLINICAL TRIAL REGISTRATION: NCT01921335.
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Neoplasias Encefálicas , Neoplasias de la Mama , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias de la Mama/tratamiento farmacológico , Humanos , Oxazoles , Piridinas , Quinazolinas , Receptor ErbB-2/genética , Trastuzumab/efectos adversos , Resultado del TratamientoRESUMEN
BACKGROUND: African Americans are reported to be more sensitive to pain than European Americans. Pain sensitivity has been shown to be genetically linked in animal models and is likely to be in humans. METHODS: Exactly, 11,239 self-identified African American post-menopausal women enrolled in the Women's Health Initiative had percentage African ancestry determined by ancestry informative markers, "Pain Construct" measurements and covariate information. They answered five questions about specific types and location of pain, such as joint, neck, low back, headache and urinary. They also answered two questions which were used to derive a "Pain Construct", a measure of general pain scored on a scale of 1-100. Associations were tested in linear regression models adjusting for age, self-reported medical conditions, neighbourhood socio-economic status, education and depression. RESULTS: In the unadjusted model of the five specific types of pain measures, greater pain perception was associated with a higher proportion of African ancestry. However, some of the specific types of pain measures were no longer associated with African ancestry after adjustment for other study covariates. The Pain Construct was statistically significantly associated with African ancestry in both the unadjusted [ß = -0.132, 95% confidence interval (CI) = -099 to -0.164; r = -0.075, 95% CI -0.056 to -0.093] and the adjusted models (ß = -0.069 95% CI = -0.04 to -0.10). CONCLUSIONS: Greater African ancestry was associated with higher levels of self-reported pain, although this accounted for only a minor fraction of the overall variation in the Pain Construct.
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Negro o Afroamericano/genética , Dolor Crónico/genética , Mujeres , Anciano , Población Negra , Dolor Crónico/epidemiología , Depresión/complicaciones , Depresión/psicología , Escolaridad , Femenino , Humanos , Persona de Mediana Edad , Dimensión del Dolor , Características de la Residencia , Clase SocialRESUMEN
PURPOSE: The association between pronuclear (PN) scoring of embryos from assisted reproductive technology (ART) and clinical pregnancy remains controversial. We hypothesized that embryos with PNs scored on the day of fertilization check offer better embryo selection on day 3 and higher CPR compared to non-PN scored embryos. METHODS: Patients (19-46 years) undergoing IVF/ICSI cycles at Montefiore's Institute for Reproductive Medicine and Health between January 2006 and December 2009 were included in our study. We analyzed fresh day 3 cycles only with autologous oocytes and partner's fresh sperm (n = 344). A total of 1,899 embryos were included. We compared CPR from non-PN scored embryos (Group 1, n = 835) with PN scored embryos (Group 2, n = 1,064). Composite scores by patient were developed based on embryo disposition. We also assessed traditional embryo grading derived from cell number, fragmentation and cell symmetry. Data analysis included chi square and t test to determine if PN scoring was associated with improved CPR, and to compare the additional variables. RESULTS: CPR between Group 1 and Group 2 were not different (p = 0.91). CPR was significantly associated with female age, number of mature oocytes retrieved, number of day 3 embryos and grade of embryos transferred on day 3 (p < 0.05). CONCLUSION: PN scoring was not associated with improved CPR in day 3 embryo transfers. Mean grade of transferred embryos continues to be a well-established, independent predictor of CPR. We conclude that further refinement of embryo grading by PN scoring is not beneficial.
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Implantación del Embrión , Transferencia de Embrión , Fertilización In Vitro , Inyecciones de Esperma Intracitoplasmáticas , Adulto , Fase de Segmentación del Huevo , Destinación del Embrión , Femenino , Humanos , Masculino , Persona de Mediana Edad , Embarazo , Técnicas Reproductivas Asistidas , Transferencia Intrafalopiana del CigotoRESUMEN
BACKGROUND: Competing resource demands have resulted in the de-escalation of vancomycin-resistant enterococcus (VRE) control programmes in some Canadian healthcare centres. AIM: To determine the attributable costs and length of stay (LOS) of VRE colonizations/infections in an acute care hospital in Canada. METHODS: Surveillance and financial hospital-based databases were used to conduct analyses with cases and controls from fiscal year 2008-2009 (1 April 2008 to 31 March 2009) at an acute care hospital in downtown Vancouver, Canada. A statistical analysis of attributable costs and LOS was conducted using a generalized linear model. In a secondary analysis, differences in costs and LOS were examined for VRE infections versus colonizations. FINDINGS: A total of 217 patients with VRE and a random sample of 1075 patients without VRE were examined. VRE has a positive and significant impact on patient hospitalization costs and LOS. Overall, the presence of VRE increased the estimated mean cost per patient by 61.9% (95% confidence interval: 42.3-84.3) in relative terms and $17,949 (13,949-21,464) in absolute Canadian dollars. For LOS, the attributable number of days associated with a VRE case mean was 68.0% (41.9-98.9) higher in relative terms and 13.8 days (10.0-16.9) in absolute days. In the secondary analysis comparing VRE infection and colonization costs, no statistically significant difference was found. CONCLUSIONS: Based on this analysis, the attributable cost and LOS of VRE are considerable. These factors should be considered before de-escalation of a hospital VRE control programme.
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Enterococcus/efectos de los fármacos , Infecciones por Bacterias Grampositivas/economía , Costos de la Atención en Salud/estadística & datos numéricos , Resistencia a la Vancomicina , Adulto , Anciano , Anciano de 80 o más Años , Canadá , Enterococcus/aislamiento & purificación , Femenino , Infecciones por Bacterias Grampositivas/microbiología , Hospitales , Humanos , Tiempo de Internación , Masculino , Persona de Mediana EdadRESUMEN
A recent study revealed that ES (embryonic stem) cell lines derived from the 129 murine strain carry an inactivating mutation within the caspase 11 gene (Casp4) locus [Kayagaki, Warming, Lamkanfi, Vande Walle, Louie, Dong, Newton, Qu, Liu, Heldens, Zhang, Lee, Roose-Girma and Dixit (2011) Nature 479, 117-121]. Thus, if 129 ES cells are used to target genes closely linked to caspase 11, the resulting mice might also carry the caspase 11 deficiency as a passenger mutation. In the present study, we examined the genetic loci of mice targeted for the closely linked c-IAP (cellular inhibitor of apoptosis) genes, which were generated in 129 ES cells, and found that, despite extensive backcrossing into a C57BL/6 background, c-IAP1(-/-) animals are also deficient in caspase 11. Consequently, data obtained from these mice should be re-evaluated in this new context.
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Caspasas/genética , Proteínas Inhibidoras de la Apoptosis/metabolismo , Mutación , Animales , Caspasas/metabolismo , Caspasas Iniciadoras , Línea Celular , Activación Enzimática , Proteínas Inhibidoras de la Apoptosis/deficiencia , Ratones , Ratones de la Cepa 129RESUMEN
Massive galaxies in the early Universe have been shown to be forming stars at surprisingly high rates. Prominent examples are dust-obscured galaxies which are luminous when observed at sub-millimetre wavelengths and which may be forming stars at a rate of 1,000 solar masses (M(middle dot in circle)) per year. These intense bursts of star formation are believed to be driven by mergers between gas-rich galaxies. Probing the properties of individual star-forming regions within these galaxies, however, is beyond the spatial resolution and sensitivity of even the largest telescopes at present. Here we report observations of the sub-millimetre galaxy SMMJ2135-0102 at redshift z = 2.3259, which has been gravitationally magnified by a factor of 32 by a massive foreground galaxy cluster lens. This magnification, when combined with high-resolution sub-millimetre imaging, resolves the star-forming regions at a linear scale of only 100 parsecs. We find that the luminosity densities of these star-forming regions are comparable to the dense cores of giant molecular clouds in the local Universe, but they are about a hundred times larger and 10(7) times more luminous. Although vigorously star-forming, the underlying physics of the star-formation processes at z approximately 2 appears to be similar to that seen in local galaxies, although the energetics are unlike anything found in the present-day Universe.
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The bacterial pathogen Klebsiella pneumoniae is a cause of community- and hospital-acquired lung, urinary tract and blood stream infections. It is a common contaminant of indwelling catheters and it is theorized in that context that systemic infection follows shedding of aggregates off of surface-adherent biofilm colonies. In an effort to better understand bacterial proliferation in the host bloodstream, we develop a PDE model for the flocculation dynamics of Klebsiella pneumoniae in suspension. Existence and uniqueness results are provided, as well as a brief description of the numerical approximation scheme. We generate artificial data and illustrate the requirements to accurately identify proliferation, aggregation, and fragmentation of flocs in the experimental domain of interest.
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Biopelículas/crecimiento & desarrollo , Klebsiella pneumoniae/fisiología , Modelos Biológicos , Simulación por Computador , Floculación , Análisis Numérico Asistido por ComputadorRESUMEN
OBJECTIVE: To determine the safety and diagnostic accuracy of adenosine-stress cardiac magnetic resonance (CMR) perfusion imaging early after acute ST elevation myocardial infarction (STEMI) compared with standard exercise tolerance testing (ETT). DESIGN AND SETTING: Cross sectional observational study in a university teaching hospital. PATIENTS: 35 patients admitted with first acute STEMI. INTERVENTIONS: All patients underwent a CMR imaging protocol which included rest and adenosine-stress perfusion, viability, and cardiac functional assessment. All patients also had an ETT (modified Bruce protocol) and x ray coronary angiography. MAIN OUTCOME MEASURES: Safety and diagnostic accuracy of adenosine-stress perfusion CMR vs ETT early after STEMI in identifying patients with significant coronary stenosis (>or=70%) and the need for coronary revascularisation. Also, to determine if CMR can distinguish between ischaemia in the peri-infarct zone and ischaemia in remote myocardium. RESULTS: CMR imaging was well tolerated (all patients completed the protocol) and no complications occurred. CMR was more sensitive (86% vs 48%, p = 0.0074) and more specific than ETT (100% vs 50%, p<0.0001) for detecting significant coronary stenosis, and more sensitive for predicting revascularisation (94% vs 56%, p = 0.039). Inducible ischaemia in the infarct related artery territory was seen in 21 of 35 patients and was associated with smaller infarct size and less transmurality of infarction. CONCLUSIONS: Adenosine-stress CMR imaging is safe early after acute STEMI and identifies patients with significant coronary stenosis more accurately than ETT.
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Infarto del Miocardio/diagnóstico , Adenosina , Anciano , Angiografía Coronaria , Estenosis Coronaria/diagnóstico , Estenosis Coronaria/terapia , Estudios Transversales , Electrocardiografía , Prueba de Esfuerzo/métodos , Tolerancia al Ejercicio , Femenino , Humanos , Imagen por Resonancia Magnética/efectos adversos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/fisiopatología , Infarto del Miocardio/terapia , Revascularización Miocárdica , Selección de PacienteRESUMEN
INTRODUCTION: This paper describes the design, implementation and evaluation of a new professional role in surgery. The role of the perioperative specialist practitioner (PSP), conceived as a response to the Working Time Directive, provides integrated preoperative and postoperative care to patients undergoing surgery in hospital. METHODS: A 1-year training programme was designed, dealing with a wide range of knowledge, skills and attitudes. Effective communication was a key component. Nine intensive 5-day modules at Imperial College London (London, UK) alternated with supervised experience of the surgical team at each participant's home trust. Detailed evaluation of the role and the training programme was provided by an independent research team, using an interview-based qualitative approach. Observational data were provided by the project team. Data were analysed using standard qualitative methods. RESULTS: 27 PSPs across 12 National Health Service trusts took part in two PSP training programmes. A total of 124 interviews (94 individual and 30 group) were carried out with PSPs and their colleagues. Overall, the role was seen as successful and positive, with great potential for dealing with reductions in junior medical cover. Each site encountered different opportunities and problems. Lack of mentorship was a key issue, and the role provoked considerable opposition in trusts. The training programme was viewed as highly successful. DISCUSSION: PSPs can provide high levels of expertise, but within clear limits. Our training programme has been effective and is perceived to be of high quality. However, introducing a new role requires time and sensitivity if opposition is to be minimised.
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Empleos Relacionados con Salud/educación , Atención Perioperativa , Rol Profesional , Especialidades Quirúrgicas/educación , Desarrollo de Personal , Adulto , Empleos Relacionados con Salud/tendencias , Hospitales Públicos , Humanos , Londres , Persona de Mediana Edad , Grupo de Atención al Paciente , Atención Dirigida al Paciente , Atención Perioperativa/tendencias , Proyectos Piloto , Desarrollo de Programa , Evaluación de Programas y Proyectos de Salud , Investigación Cualitativa , Facultades de Medicina , Especialidades Quirúrgicas/tendencias , Medicina Estatal , Recursos HumanosRESUMEN
Cystic fibrosis arises from the misfolding and premature degradation of CFTR Delta F508, a Cl- ion channel with a single amino acid deletion. Yet, the quality-control machinery that selects CFTR Delta F508 for degradation and the mechanism for its misfolding are not well defined. We identified an ER membrane-associated ubiquitin ligase complex containing the E3 RMA1, the E2 Ubc6e, and Derlin-1 that cooperates with the cytosolic Hsc70/CHIP E3 complex to triage CFTR and CFTR Delta F508. Derlin-1 serves to retain CFTR in the ER membrane and interacts with RMA1 and Ubc6e to promote CFTR's proteasomal degradation. RMA1 is capable of recognizing folding defects in CFTR Delta F508 coincident with translation, whereas the CHIP E3 appears to act posttranslationally. A folding defect in CFTR Delta F508 detected by RMA1 involves the inability of CFTR's second membrane-spanning domain to productively interact with amino-terminal domains. Thus, the RMA1 and CHIP E3 ubiquitin ligases act sequentially in ER membrane and cytosol to monitor the folding status of CFTR and CFTR Delta F508.
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Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Proteínas de Unión al ADN/metabolismo , Retículo Endoplásmico/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Línea Celular , Fibrosis Quística/genética , Fibrosis Quística/metabolismo , Fibrosis Quística/fisiopatología , Regulador de Conductancia de Transmembrana de Fibrosis Quística/química , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Proteínas del Choque Térmico HSC70/metabolismo , Humanos , Membranas Intracelulares/metabolismo , Proteínas de la Membrana/metabolismo , Pliegue de Proteína , Procesamiento Proteico-Postraduccional/fisiología , Estructura Terciaria de Proteína/fisiología , Proteínas de Saccharomyces cerevisiae/metabolismo , Enzimas Ubiquitina-Conjugadoras/metabolismoRESUMEN
The complement cascade is activated and contributes to brain damage after intracerebral hemorrhage (ICH). The present study investigated ICH-induced brain damage in complement C3-deficient mice. This study was divided into 2 parts. Male C3-deficient and C3-sufficient mice received an infusion of 30-microl autologous whole blood into the right basal ganglia. In the first part of our study, mice were killed 3 days later for brain water content measurement. Behavioral assessments including forelimb use asymmetry and corner turn tests were also preformed before and after ICH. In the second part of the study, brain heme oxygenase-1 (HO-1) was measured by Western blot analysis and immunohistochemistry 3 days after the infusion. We found that brain water content in the ipsilateral basal ganglia 3 days after ICH was less in C3-deficient mice compared to C3-sufficient mice (p < 0.05). The C3-deficient mice had reduced ICH-induced forelimb use asymmetry deficits compared with C3-sufficient mice (p < 0.05), although there was no significant difference in the corner turn test score. Western blot analysis showed that HO-1 contents were significantly lower in C3-deficient mice (day 3: 2024 +/- 560 vs. 5140 +/- 1151 pixels in the C3-sufficient mice, p < 0.05). We conclude that ICH causes less brain edema and behavioral deficits in complement C3-deficient mice. These results suggest that complement C3 is a key factor contributing to brain injury following ICH.
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Edema Encefálico/inmunología , Encéfalo/inmunología , Hemorragia Cerebral/inmunología , Complemento C3/deficiencia , Complemento C3/inmunología , Modelos Animales de Enfermedad , Hemo-Oxigenasa 1/inmunología , Animales , Edema Encefálico/etiología , Lesiones Encefálicas/etiología , Lesiones Encefálicas/inmunología , Hemorragia Cerebral/complicaciones , Ratones , Ratones Endogámicos C57BLRESUMEN
The cytoplasm is protected against the perils of protein misfolding by two mechanisms: molecular chaperones (which facilitate proper folding) and the ubiquitin-proteasome system, which regulates degradation of misfolded proteins. CHIP (carboxyl terminus of Hsp70-interacting protein) is an Hsp70-associated ubiquitin ligase that participates in this process by ubiquitylating misfolded proteins associated with cytoplasmic chaperones. Mechanisms that regulate the activity of CHIP are, at present, poorly understood. Using a proteomics approach, we have identified BAG2, a previously uncharacterized BAG domain-containing protein, as a common component of CHIP holocomplexes in vivo. Binding assays indicate that BAG2 associates with CHIP as part of a ternary complex with Hsc70, and BAG2 colocalizes with CHIP under both quiescent conditions and after heat shock. In vitro and in vivo ubiquitylation assays indicate that BAG2 is an efficient and specific inhibitor of CHIP-dependent ubiquitin ligase activity. This activity is due, in part, to inhibition of interactions between CHIP and its cognate ubiquitin-conjugating enzyme, UbcH5a, which may in turn be facilitated by ATP-dependent remodeling of the BAG2-Hsc70-CHIP heterocomplex. The association of BAG2 with CHIP provides a cochaperone-dependent regulatory mechanism for preventing unregulated ubiquitylation of misfolded proteins by CHIP.
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Citoplasma/metabolismo , Regulación de la Expresión Génica , Proteínas HSP70 de Choque Térmico/metabolismo , Adenosina Trifosfato/química , Secuencia de Aminoácidos , Línea Celular , Cromatina/química , Inmunoprecipitación de Cromatina , Proteínas de Drosophila/química , Eliminación de Gen , Glutatión Transferasa/metabolismo , Proteínas HSP70 de Choque Térmico/química , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Proteínas de Unión a Hierro/química , Espectrometría de Masas , Modelos Biológicos , Chaperonas Moleculares/química , Chaperonas Moleculares/metabolismo , Datos de Secuencia Molecular , Proteínas Nucleares/química , Complejo de la Endopetidasa Proteasomal/química , Unión Proteica , Conformación Proteica , Pliegue de Proteína , Factores de Tiempo , Transfección , Ubiquitina/química , Enzimas Ubiquitina-Conjugadoras/química , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Components of the ubiquitin-proteasome system function on the surface of the endoplasmic reticulum (ER) to select misfolded proteins for degradation. Herein we describe methods that allow for the study of the pathway for proteasomal degradation of the cystic fibrosis transmembrane conductance regulator (CFTR). The experimental system described employs transiently transfected HEK-293 cells and is utilized to monitor the biogenesis of CFTR by Western blot and pulse-chase analysis.
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Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Retículo Endoplásmico/enzimología , Complejo de la Endopetidasa Proteasomal/metabolismo , Pliegue de Proteína , Línea Celular , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Expresión Génica , Humanos , Modelos Moleculares , TransfecciónRESUMEN
CFTRDeltaF508 exhibits a correctable protein-folding defect that leads to its misfolding and premature degradation, which is the cause of cystic fibrosis (CF). Herein we report on the characterization of the CFTRDeltaF508 biogenic intermediate that is selected for proteasomal degradation and identification of cellular components that polyubiquitinate CFTRDeltaF508. Nonubiquitinated CFTRDeltaF508 accumulates in a kinetically trapped, but folding competent conformation, that is maintained in a soluble state by cytosolic Hsc70. Ubiquitination of Hsc70-bound CFTRDeltaF508 requires CHIP, a U box containing cytosolic cochaperone. CHIP is demonstrated to function as a scaffold that nucleates the formation of a multisubunit E3 ubiquitin ligase whose reconstituted activity toward CFTR is dependent upon Hdj2, Hsc70, and the E2 UbcH5a. Inactivation of the Hsc70-CHIP E3 leads CFTRDeltaF508 to accumulate in a nonaggregated state, which upon lowering of cell growth temperatures, can fold and reach the cell surface. Inhibition of CFTRDeltaF508 ubiquitination can increase its cell surface expression and may provide an approach to treat CF.
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Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/farmacología , Proteínas HSP70 de Choque Térmico/metabolismo , Chaperonas Moleculares/metabolismo , Pliegue de Proteína , Ubiquitina-Proteína Ligasas/antagonistas & inhibidores , Animales , Células COS , Línea Celular , Chlorocebus aethiops , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Retículo Endoplásmico/metabolismo , Regulación de la Expresión Génica , Proteínas del Choque Térmico HSC70 , Humanos , Proteínas de Unión a Hierro/genética , Proteínas de Unión a Hierro/metabolismo , Enzimas Ubiquitina-Conjugadoras/genética , Enzimas Ubiquitina-Conjugadoras/metabolismo , Ubiquitina-Proteína Ligasas/metabolismoAsunto(s)
Geriatría , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori , Úlcera Péptica/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Infecciones por Helicobacter/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Úlcera Péptica/diagnóstico , Factores de RiesgoRESUMEN
The complement cascade is activated after experimental intracerebral hemorrhage (ICH) and may play an important, role in edema formation. This study investigated the effects of systemic complement depletion on brain edema formation following ICH. Thirty-six pentobarbital-anesthetized Sprague-Dawley rats were used. Treatment animals were complement-depleted with cobra venom factor (CVF) while controls received an equal volume of saline injection (i.p.). In both treatment and control rats, autologous blood (100-microL) was infused stereotactically into the right basal ganglia. Rats were sacrificed one and three days later for brain water and ion content measurements and immunohistochemical studies. Immunohistochemistry was used to detect complement C3d, C5a, and C9. Western blot analysis was applied for C9 semiquantitation. Perihematomal brain edema was reduced by systemic complement depletion at one and three days. The water content of the cerebellum (a tissue distant from the hematoma site) was unaffected by complement depletion. Immunocytochemistry found complement depletion significantly reduced perihematomal C9 deposition, C3d production, and C5a positive cell accumulation. In conclusion, complement depletion by CVF attenuates brain edema in ICH perhaps by inhibiting the inflammatory response and membrane attack complex (MAC) formation.