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G-protein-coupled receptors (GPCRs) are the largest family of membrane proteins, regulate a plethora of physiological responses and are the therapeutic target for 30-40% of clinically-prescribed drugs. They are integral membrane proteins deeply embedded in the plasma membrane where they activate intracellular signalling via coupling to G-proteins and ß-arrestin. GPCRs are in intimate association with the bilayer lipids and that lipid environment regulates the signalling functions of GPCRs. This complex lipid 'landscape' is both heterogeneous and dynamic. GPCR function is modulated by bulk membrane properties including membrane fluidity, microdomains, curvature, thickness and asymmetry but GPCRs are also regulated by specific lipid:GPCR binding, including cholesterol and anionic lipids. Understanding the molecular mechanisms whereby GPCR signalling is regulated by lipids is a very active area of research currently. A major advance in membrane protein research in recent years was the application of poly(styrene-co-maleic acid) (SMA) copolymers. These spontaneously generate SMA lipid particles (SMALPs) encapsulating membrane protein in a nano-scale disc of cell membrane, thereby removing the historical need for detergent and preserving lipid:GPCR interaction. The focus of this review is how GPCR-SMALPs are increasing our understanding of GPCR structure and function at the molecular level. Furthermore, an increasing number of 'second generation' SMA-like copolymers have been reported recently. These are reviewed from the context of increasing our understanding of GPCR molecular mechanisms. Moreover, their potential as a novel platform for downstream biophysical and structural analyses is assessed and looking ahead, the translational application of SMA-like copolymers to GPCR drug discovery programmes in the future is considered.
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Receptores Acoplados a Proteínas G , Membrana Celular , Lípidos/química , Proteínas de la Membrana/químicaRESUMEN
This study aimed to consider childhood poverty in relation to a count measure of adverse childhood experiences (ACEs) as a predictor of adult health outcomes and to determine whether associations are sensitive to how childhood poverty is operationalized. A sample of 10,784 adult residents was derived using data 2014-2015 Wisconsin annual Behavioral Risk Factor Survey data, derived from the Centers for Disease Control and Prevention (CDC) Behavioral Risk Factor Surveillance System (BRFSS). Adult health outcomes (health risk behaviors, general health problems, chronic health problems, and depression) were predicted using a more conservative and severe indicator of childhood poverty, and authors tested whether observed associations were attenuated by the inclusion of an ACE count variable. Findings showed that severe indicators of childhood poverty are associated with general and chronic health problems as well as adult depression. These associations are attenuated, but remain intact, when ACEs are included in regression models. Using the CDC BRFSS data for Wisconsin, the study showed that associations between childhood poverty and adult health are sensitive to the way in which childhood poverty is operationalized. The relationship between childhood poverty and other ACEs is complex and thus warrants treating the former as a distinct childhood adversity rather than an item in an ACE summary score.
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Experiencias Adversas de la Infancia , Adulto , Sistema de Vigilancia de Factor de Riesgo Conductual , Humanos , Evaluación de Resultado en la Atención de Salud , Pobreza , Factores de RiesgoRESUMEN
Membrane contact sites (MCS) are zones of contact between the membranes of two organelles. At MCS, specific proteins tether the organelles in close proximity and mediate the nonvesicular trafficking of lipids and ions between the two organelles. The endoplasmic reticulum (ER) integral membrane protein VAP is a common component of MCS involved in both tethering and lipid transfer by binding directly to proteins containing a FFAT [two phenylalanines (FF) in an acidic tract (AT)] motif. In addition to maintaining cell homeostasis, MCS formation recently emerged as a mechanism by which intracellular pathogens hijack cellular resources and establish their replication niche. Here, we investigated the mechanism by which the Chlamydia-containing vacuole, termed the inclusion, establishes direct contact with the ER. We show that the Chlamydia protein IncV, which is inserted into the inclusion membrane, displays one canonical and one noncanonical FFAT motif that cooperatively mediated the interaction of IncV with VAP. IncV overexpression was sufficient to bring the ER in close proximity of IncV-containing membranes. Although IncV deletion partially decreased VAP association with the inclusion, it did not suppress the formation of ER-inclusion MCS, suggesting the existence of redundant mechanisms in MCS formation. We propose a model in which IncV acts as one of the primary tethers that contribute to the formation of ER-inclusion MCS. Our results highlight a previously unidentified mechanism of bacterial pathogenesis and support the notion that cooperation of two FFAT motifs may be a common feature of VAP-mediated MCS formation. Chlamydia-host cell interaction therefore constitutes a unique system to decipher the molecular mechanisms underlying MCS formation.
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Secuencias de Aminoácidos/fisiología , Proteínas Bacterianas/metabolismo , Chlamydia/metabolismo , Retículo Endoplásmico/metabolismo , Vacuolas/metabolismo , Sitios de Unión/fisiología , Proteínas Portadoras/metabolismo , Línea Celular , Línea Celular Tumoral , Retículo Endoplásmico/microbiología , Células HEK293 , Células HeLa , Humanos , Cuerpos de Inclusión/metabolismo , Cuerpos de Inclusión/microbiología , Proteínas de la Membrana/metabolismo , Unión Proteica/fisiología , Transporte de Proteínas/fisiología , Vacuolas/microbiología , Proteínas de Transporte Vesicular/metabolismoRESUMEN
BACKGROUND: The relationship between a clinician and their client-the "therapeutic alliance" is a robust predictor of outcome in healthcare settings; yet, few interventions to improve alliance have been tested. Motivational interviewing is a client-centered approach that embodies many principles and strategies consistent with a strong therapeutic alliance. PURPOSE: To examine whether alliance is enhanced by training dietitians to deliver a motivational interviewing informed health behavior change intervention ("Eating as Treatment"; EAT) as part of routine consultations with patients with head and neck cancer. The predictive ability of motivational interviewing techniques was also assessed. METHODS: A secondary analysis of the EAT stepped-wedge cluster-randomized controlled trial was conducted. Patients with head and neck cancer undergoing radiotherapy (n = 307) were treated by radiotherapy dietitians (n = 29) during the control (Treatment as Usual) or intervention (EAT) phase. Alliance was rated during the first and final weeks of radiotherapy, and again 4 and 12 weeks post-radiotherapy. Dietetic sessions were audiotaped. Week one sessions were objectively rated for dietitians' use of motivational interviewing techniques. RESULTS: Generalized linear-mixed effects regressions found no effect of EAT on dietitian-rated alliance (p = .237). After excluding outliers, patient-rated alliance was 0.29 points lower after EAT training (p = .016). Post hoc analyses revealed lower patient ratings on perceived support and dietitian confidence. Hierarchical multiple regressions found that no specific motivational interviewing techniques predicted patient-rated alliance. Dietitian acknowledgment of patient challenges was related to dietitian-rated alliance (ß =.15, p =.035). CONCLUSIONS: Patient and dietitian ratings of alliance were high after EAT training, but not significantly improved. Further research is needed to better understand the differential impact of intervention training and delivery on patient and clinician ratings of therapeutic alliance. CLINICAL TRIAL INFORMATION: Trial registration number ACTRN12613000320752.
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Neoplasias de Cabeza y Cuello/psicología , Conductas Relacionadas con la Salud , Nutricionistas/psicología , Alianza Terapéutica , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Entrevista Motivacional , Evaluación de Programas y Proyectos de Salud/estadística & datos numéricos , Ensayos Clínicos Controlados Aleatorios como Asunto , EnseñanzaRESUMEN
Our laboratory has recently demonstrated that low concentrations of ouabain increase blood pressure in rats associated with stimulation of NaK ATPase activity and activation of the Src signaling cascade in NHE1-dependent manner. Proteomic analysis of human kidney proximal tubule cells (HKC11) suggested that the Angiotensin II type 1 receptor (AT1R) as an ouabain-associating protein. We hypothesize that ouabain-induced stimulation of NaK ATPase activity is mediated through AT1R. To test this hypothesis, we examined the effect of ouabain on renal cell angiotensin II production, the effect of AT1R inhibition on ouabain-stimulated NKA activity, and the effect of ouabain on NKA-AT1R association. Ouabain increased plasma angiotensin II levels in rats treated with ouabain (1µg/kg body wt./day) for 9days and increased angiotensin II levels in cell culture media after 24h treatment with ouabain in human (HKC11), mouse (MRPT), and human adrenal cells. Ouabain 10pM stimulated NKA-mediated 86Rb uptake and phosphorylation of EGFR, Src, and ERK1/2. These effects were prevented by the AT1R receptor blocker candesartan. FRET and TIRF microscopy using Bodipy-labeled ouabain and mCherry-NKA or mCherry-AT1R demonstrated association of ouabain with AT1R and NKA. Further our FRET and TIRF studies demonstrated increased association between AT1R and NKA upon treatment with low dose ouabain. We conclude that ouabain stimulates NKA in renal proximal tubule cells through an angiotensin/AT1R-dependent mechanism and that this pathway contributes to cardiac glycoside associated hypertension.
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Activadores de Enzimas/farmacología , Túbulos Renales Proximales/efectos de los fármacos , Ouabaína/farmacología , Receptor de Angiotensina Tipo 1/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Angiotensina II/metabolismo , Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Angiotensinógeno/metabolismo , Animales , Línea Celular , Relación Dosis-Respuesta a Droga , Activación Enzimática , Activadores de Enzimas/toxicidad , Hipertensión/inducido químicamente , Hipertensión/enzimología , Túbulos Renales Proximales/enzimología , Ratones , Ouabaína/toxicidad , Peptidil-Dipeptidasa A/metabolismo , Fosforilación , Unión Proteica , Ratas Sprague-Dawley , Receptor de Angiotensina Tipo 1/genética , Transducción de Señal/efectos de los fármacos , ATPasa Intercambiadora de Sodio-Potasio/genética , TransfecciónRESUMEN
BACKGROUND: Clinical guidelines support decision-making at the point-of-care but the onus is often on individual users such as physicians to implement them. Research shows that the inclusion of implementation tools in or with guidelines (GItools) is associated with guideline use. However, there is little research on which GItools best support implementation by individual physicians. The purpose of this study was to investigate naturalistic access and use of GItools produced by the American Academy of Neurology (AAN) to inform future tool development. METHODS: Website accesses over six months were summarized for eight AAN guidelines and associated GItools published between July 2012 and August 2013. Academy members were surveyed about use of tools accompanying the sport concussion guideline. Data were analyzed using summary statistics and the Chi-square test. RESULTS: The clinician summary was accessed more frequently (29.0%, p < 0.001) compared with the slide presentation (26.8%), patient summary (23.2%) or case study (20.9%), although this varied by guideline topic. For the sport concussion guideline, which was accompanied by a greater variety of GItools, the mobile phone quick reference check application was most frequently accessed, followed by the clinician summary, patient summary, and slide presentation. For the sports concussion guideline survey, most respondents (response rate 21.8%, 168/797) were aware of the guideline (88.1%) and had read the guideline (78.6%). For GItool use, respondents indicated reading the reference card (51.2%), clinician summary (45.2%), patient summary (28.0%), mobile phone application (26.2%), and coach/athletic trainer summary (20.2%). Patterns of sports concussion GItool use were similar between respondents who said they had and had not yet implemented the guideline. CONCLUSIONS: Developers faced with resource limitations may wish to prioritize the development of printable or mobile application clinician summaries, which were accessed significantly more than other types of GItools. Further research is needed to understand how to optimize the design of such GItools.
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Sistemas de Apoyo a Decisiones Clínicas/estadística & datos numéricos , Aplicaciones de la Informática Médica , Médicos/estadística & datos numéricos , Guías de Práctica Clínica como Asunto , Pautas de la Práctica en Medicina/estadística & datos numéricos , Humanos , Neurología/normas , Sociedades Médicas/normasRESUMEN
Parathyroid hormone (PTH) is a key regulator of the expression and function of the type IIa sodium-phosphate cotransporter (Npt2a), the protein responsible for regulated renal phosphate reabsorption. We previously showed that PTH induces rapid decay of Npt2a mRNA through posttranscriptional mechanisms. We hypothesized that PTH-induced changes in RNA-binding protein (RBP) activity mediate the degradation of Npt2a mRNA. To address this aim, we treated opossum kidney (OK) cells, a PTH-sensitive proximal tubule cell culture model, with 100 nM PTH for 30 min and 2 h, followed by mass spectrometry characterization of the PTH-stimulated phosphoproteome. We identified 1,182 proteins differentially phosphorylated in response to PTH, including 68 RBPs. Preliminary analysis identified a phospho-RBP, hnRNPK-homology-type-splicing regulatory protein (KSRP), with predicted binding sites for the 3'-untranslated region (UTR) of Npt2a mRNA. Western blot analysis confirmed expression of KSRP in OK cells and showed PTH-dependent translocation to the nucleus. Immunoprecipitation of KSRP from control and PTH-treated cells followed by RNA isolation and RT-quantitative PCR analysis identified Npt2a mRNA from both control and PTH-treated KSRP pulldowns. Knockdown of KSRP followed by PTH treatment showed that KSRP is required for mediating PTH-stimulated reduction in sodium/hydrogen exchanger 3 mRNA, but not Npt2a mRNA. We conclude that 1) PTH is a major regulator of both transcription and translation, and 2) KSRP binds Npt2a mRNA but its role in PTH regulation of Npt2a mRNA is not clear.
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Túbulos Renales Proximales/efectos de los fármacos , Hormona Paratiroidea/farmacología , Estabilidad del ARN , ARN Mensajero/genética , Proteínas de Unión al ARN/metabolismo , Proteínas Cotransportadoras de Sodio-Fosfato de Tipo IIa/genética , Regiones no Traducidas 3' , Animales , Sitios de Unión , Línea Celular , Biología Computacional , Bases de Datos Genéticas , Túbulos Renales Proximales/metabolismo , Espectrometría de Masas , Zarigüeyas , Fosforilación , Unión Proteica , Proteómica/métodos , Interferencia de ARN , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/genética , Proteínas Cotransportadoras de Sodio-Fosfato de Tipo IIa/metabolismo , Factores de Tiempo , Transactivadores/genética , Transactivadores/metabolismo , TransfecciónRESUMEN
BACKGROUND/AIMS: Phosphate homeostasis is controlled by the renal reabsorption of Pi by the type IIa sodium phosphate cotransporter, Npt2a, which is localized in the proximal tubule brush border membrane. Regulation of Npt2a expression is a key control point to maintain phosphate homeostasis with most studies focused on regulating protein levels in the brush border membrane. Molecular mechanisms that control Npt2a mRNA, however, remain to be defined. We have reported that Npt2a mRNA and protein levels correlate directly with the expression of the Na+/H+ exchanger regulatory factor 1 (NHERF-1) using opossum kidney (OK) cells and the NHERF-1-deficient OK-H cells. The goal of this study was to determine whether NHERF-1 contributes to transcriptional and/or post-transcriptional mechanisms controlling Npt2a mRNA levels. METHODS: Npt2a mRNA half-life was compared between OK and NHERF-1 deficient OK-H cell lines. oNpt2a promoter-reporter gene assays and electrophoretic mobility shift assays (EMSA) were used identify a NHERF-1 responsive region within the oNpt2a proximal promoter. RESULTS: Npt2a mRNA half-life is the same in OK and OK-H cells. The NHERF-1 responsive region lies within the proximal promoter in a region that contains a highly conserved CAATT box and G-rich element. Specific protein-DNA complex formation with the CAATT element is altered by the absence of NHERF-1 (OK v OK-H EMSA) although NHERF-1 does not directly contribute to complex formation. CONCLUSION: NHERF-1 helps maintain steady-state Npt2a mRNA levels in OK cells through indirect mechanisms that help promote protein-DNA interactions at the Npt2a proximal promoter.
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ADN/genética , Fosfoproteínas/genética , Regiones Promotoras Genéticas/genética , Intercambiadores de Sodio-Hidrógeno/genética , Proteínas Cotransportadoras de Sodio-Fosfato de Tipo IIa/genética , Animales , Secuencia de Bases , Sitios de Unión/genética , Línea Celular , ADN/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Túbulos Renales Proximales/citología , Túbulos Renales Proximales/efectos de los fármacos , Túbulos Renales Proximales/metabolismo , Zarigüeyas , Fosfatos/metabolismo , Fosfatos/farmacología , Fosfoproteínas/metabolismo , Unión Proteica , Estabilidad del ARN/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Intercambiadores de Sodio-Hidrógeno/metabolismo , Proteínas Cotransportadoras de Sodio-Fosfato de Tipo IIa/metabolismoRESUMEN
Recent studies suggest that at low concentrations, ouabain increases Na-K ATPase and NHE1 activity and activates the Src signaling cascade in proximal tubule cells. Our laboratory demonstrated that low concentrations of ouabain increase blood pressure in rats. We hypothesize that ouabain-induced increase in blood pressure and Na-K ATPase activity requires NHE1 activity and association. To test this hypothesis we treated rats with ouabain (1µgkg body wt(-1)day(-1)) for 9days in the presence or absence of the NHE1 inhibitor, zoniporide. Ouabain stimulated a significant increase in blood pressure which was prevented by zoniporide. Using NHE1-expressing Human Kidney cells 2 (HK2), 8 (HK8) and 11 (HK11) and Mouse Kidney cells from Wild type (WT) and NHE1 knock-out mice (SWE) cell lines, we show that ouabain stimulated Na-K ATPase activity and surface expression in a Src-dependent manner in NHE1-expressing cells but not in NHE1-deplete cells. Zoniporide prevented ouabain-induced stimulation of (86)Rb uptake in the NHE1-expressing cells. FRET and TIRF microscopy showed that ouabain increased association between GFP-NHE1 and mCherry-Na-K ATPase transfected into NHE1-deficient SWE cells. Mutational analysis demonstrated that the caveolin binding motif (CBM) of Na-K ATPase α1 is required for translocation of both Na-K ATPase α1 and NHE1 to the basolateral membrane. Mutations in activity or scaffold domains of NHE1 resulted in loss of ouabain-mediated regulation of Na-K ATPase. These results support that NHE1 is required for the ouabain-induced increase in blood pressure, and that the caveolin binding motif of Na-K ATPase α1 as well as the activity and scaffolding domains of NHE1 are required for their functional association.
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Cardiotónicos/farmacología , Proteínas de Transporte de Catión/fisiología , Túbulos Renales Proximales/efectos de los fármacos , Ouabaína/farmacología , Intercambiadores de Sodio-Hidrógeno/fisiología , ATPasa Intercambiadora de Sodio-Potasio/química , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Biotinilación , Presión Sanguínea/efectos de los fármacos , Western Blotting , Caveolina 1/metabolismo , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Células Cultivadas , Transferencia Resonante de Energía de Fluorescencia , Humanos , Hidrólisis , Técnicas para Inmunoenzimas , Transporte Iónico/efectos de los fármacos , Túbulos Renales Proximales/citología , Túbulos Renales Proximales/metabolismo , Masculino , Ratones , Ratones Noqueados , Fosforilación/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Intercambiador 1 de Sodio-Hidrógeno , Familia-src Quinasas/metabolismoRESUMEN
Na+/H+ exchanger regulatory factor (NHERF1) plays a critical role in the renal transport of phosphate by binding to Na+-Pi cotransporter (NpT2a) in the proximal tubule. While the association between NpT2a and NHERF1 in the apical membrane is known, the role of NHERF1 to regulate the trafficking of NpT2a has not been studied. To address this question, we performed cell fractionation by sucrose gradient centrifugation in opossum kidney (OK) cells placed in low-Pi medium to stimulate forward trafficking of NpT2a. Immunoblot analysis demonstrated expression of NpT2a and NHERF1 in the endoplasmic reticulum (ER)/Golgi. Coimmunoprecipitation demonstrated a NpT2a-NHERF1 interaction in the ER/Golgi. Low-Pi medium for 4 and 8 h triggered a decrease in NHERF1 in the plasma membrane with a corresponding increase in the ER/Golgi. Time-lapse total internal reflection fluorescence imaging of OK cells placed in low-Pi medium, paired with particle tracking and mean square displacement analysis, indicated active directed movement of NHERF1 at early and late time points, whereas NpT2a showed active movement only at later times. Silence of NHERF1 in OK cells expressing green fluorescent protein (GFP)-NpT2a resulted in an intracellular accumulation of GFP-NpT2a. Transfection with GFP-labeled COOH-terminal (TRL) PDZ-binding motif deleted or wild-type NpT2a in OK cells followed by cell fractionation and immunoprecipitation confirmed that the interaction between NpT2a and NHERF1 was dependent on the TRL motif of NpT2a. We conclude that appropriate trafficking of NpT2a to the plasma membrane is dependent on the initial association between NpT2a and NHERF1 through the COOH-terminal TRL motif of NpT2a in the ER/Golgi and requires redistribution of NHERF1 to the ER/Golgi.
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Retículo Endoplásmico/metabolismo , Aparato de Golgi/metabolismo , Riñón/metabolismo , Fosfoproteínas/metabolismo , Intercambiadores de Sodio-Hidrógeno/metabolismo , Proteínas Cotransportadoras de Sodio-Fosfato de Tipo IIa/metabolismo , Animales , Línea Celular , DidelphisRESUMEN
BACKGROUND: Evidence-based clinical practice guidelines (CPGs) are statements that provide recommendations to optimize patient care for a specific clinical problem or question. Merely reading a guideline rarely leads to implementation of recommendations. The American Academy of Neurology (AAN) has a formal process of guideline development and dissemination. The last few years have seen a burgeoning of social media such as Facebook, Twitter, and LinkedIn, and newer methods of dissemination such as podcasts and webinars. The role of these media in guideline dissemination has not been studied. Systematic evaluation of dissemination methods and comparison of the effectiveness of newer methods with traditional methods is not available. It is also not known whether specific dissemination methods may be more effectively targeted to specific audiences. OBJECTIVE: Our aim was to (1) develop an innovative dissemination strategy by adding social media-based dissemination methods to traditional methods for the AAN clinical practice guidelines "Complementary and alternative medicine in multiple sclerosis" ("CAM in MS") and (2) evaluate whether the addition of social media outreach improves awareness of the CPG and knowledge of CPG recommendations, and affects implementation of those recommendations. METHODS: Outcomes were measured by four surveys in each of the two target populations: patients and physicians/clinicians ("physicians"). The primary outcome was the difference in participants' intent to discuss use of complementary and alternative medicine (CAM) with their physicians or patients, respectively, after novel dissemination, as compared with that after traditional dissemination. Secondary outcomes were changes in awareness of the CPG, knowledge of CPG content, and behavior regarding CAM use in multiple sclerosis (MS). RESULTS: Response rates were 25.08% (622/2480) for physicians and 43.5% (348/800) for patients. Awareness of the CPG increased after traditional dissemination (absolute difference, 95% confidence interval: physicians 36%, 95% CI 25-46, and patients 10%, 95% CI 1-11) but did not increase further after novel dissemination (physicians 0%, 95% CI -11 to 11, and patients -4%, 95% CI -6 to 14). Intent to discuss CAM also increased after traditional dissemination but did not change after novel dissemination (traditional: physicians 12%, 95% CI 2-22, and patients 19%, 95% CI 3-33; novel: physicians 11%, 95% CI -1 to -21, and patients -8%, 95% CI -22 to 8). Knowledge of CPG recommendations and behavior regarding CAM use in MS did not change after either traditional dissemination or novel dissemination. CONCLUSIONS: Social media-based dissemination methods did not confer additional benefit over print-, email-, and Internet-based methods in increasing CPG awareness and changing intent in physicians or patients. Research on audience selection, message formatting, and message delivery is required to utilize Web 2.0 technologies optimally for dissemination.
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Terapias Complementarias/estadística & datos numéricos , Difusión de la Información/métodos , Esclerosis Múltiple/terapia , Guías de Práctica Clínica como Asunto , Medios de Comunicación Sociales , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana EdadRESUMEN
The acute inhibitory effects of parathyroid hormone (PTH) on proximal tubule Na(+)-K(+)-ATPase (Na-K) and sodium-dependent phosphate (NaPi) transport have been extensively studied, while little is known about the chronic effects of PTH. Patients with primary hyperparathyroidism, a condition characterized by chronic elevations in PTH, exhibit persistent hypophosphatemia but not significant evidence of salt wasting. We postulate that chronic PTH stimulation results in differential desensitization of PTH responses. To address this hypothesis, we compared the effects of chronic PTH stimulation on Na-P(i) cotransporter (Npt2a) expression and Na-K activity and expression in Sprague Dawley rats, transgenic mice featuring parathyroid-specific cyclin D1 overexpression (PTH-D1), and proximal tubule cell culture models. We demonstrated a progressive decrease in brush-border membrane (BBM) expression of Npt2a from rats treated with PTH for 6 h or 4 days, while Na-K expression and activity in the basolateral membranes (BLM) exhibited an initial decrease followed by recovery to control levels by 4 days. Npt2a protein expression in PTH-D1 mice was decreased relative to control animals, whereas levels of Na-K, NHERF-1, and PTH receptor remained unchanged. In PTH-D1 mice, NpT2a mRNA expression was reduced by 50% relative to control mice. In opossum kidney proximal tubule cells, PTH decreased Npt2a mRNA levels. Both actinomycin D and cycloheximide treatment prevented the PTH-mediated decrease in Npt2a mRNA, suggesting that the PTH response requires transcription and translation. These findings suggest that responses to chronic PTH exposure are selectively regulated at a posttranscriptional level. The persistence of the phosphaturic response to PTH occurs through posttranscriptional mechanisms.
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Hipofosfatemia/genética , Túbulos Renales Proximales/fisiología , Hormona Paratiroidea/metabolismo , Estabilidad del ARN/fisiología , Proteínas Cotransportadoras de Sodio-Fosfato de Tipo IIa/genética , Animales , Células Cultivadas , Ciclina D1/genética , Ciclina D1/metabolismo , Modelos Animales de Enfermedad , Hipofosfatemia/metabolismo , Corteza Renal/citología , Corteza Renal/fisiología , Túbulos Renales Proximales/citología , Ratones , Ratones Transgénicos , Zarigüeyas , Hormona Paratiroidea/farmacología , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Procesamiento Postranscripcional del ARN/efectos de los fármacos , Procesamiento Postranscripcional del ARN/fisiología , Estabilidad del ARN/efectos de los fármacos , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Receptor de Hormona Paratiroídea Tipo 1/metabolismo , Intercambiadores de Sodio-Hidrógeno/genética , Intercambiadores de Sodio-Hidrógeno/metabolismo , Proteínas Cotransportadoras de Sodio-Fosfato de Tipo IIa/metabolismoRESUMEN
OBJECTIVE: To explore the crisis of identity in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) through the lens of Communities of Practice. METHODS: A closed Facebook group was created to gather qualitative data from participants diagnosed with CFS/ME (n = 22). Data were analysed using a theoretical thematic analysis. RESULTS: The current research revealed the reality of enabling and disabling communities in the lived experience of CFS/ME and the role of participation in developing empowered identities. Learning how to be alongside CFS/ME aligned with participants' experiences of purpose and meaning. New identities may be developed which are not centrally defined by loss or stigma. DISCUSSION: Participation in supportive communities enables CFS/ME identities to emerge as a platform for positive change. Engaging with the CFS/ME virtual community may be a way for both families and health professionals to reflect on current practice.
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Síndrome de Fatiga Crónica , Humanos , Investigación Cualitativa , Estigma SocialRESUMEN
Combined magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) may enhance diagnosis, aid surgical planning and intra-operative orientation for prostate biopsy and radical prostatectomy. Although PET-MRI may provide these benefits, PET-MRI machines are not widely available. Image fusion of Prostate specific membrane antigen PET/CT and MRI acquired separately may be a suitable clinical alternative. This study compares CT-MR registration algorithms for urological prostate cancer care. Paired whole-pelvis MR and CT scan data were used (n = 20). A manual prostate CTV contour was performed independently on each patients MR and CT image. A semi-automated rigid-, automated rigid- and automated non-rigid registration technique was applied to align the MR and CT data. Dice Similarity Index (DSI), 95% Hausdorff distance (95%HD) and average surface distance (ASD) measures were used to assess the closeness of the manual and registered contours. The automated non-rigid approach had a significantly improved performance compared to the automated rigid- and semi-automated rigid-registration, having better average scores and decreased spread for the DSI, 95%HD and ASD (all p < 0.001). Additionally, the automated rigid approach had similar significantly improved performance compared to the semi-automated rigid registration across all accuracy metrics observed (all p < 0.001). Overall, all registration techniques studied here demonstrated sufficient accuracy for exploring their clinical use. While the fully automated non-rigid registration algorithm in the present study provided the most accurate registration, the semi-automated rigid registration is a quick, feasible, and accessible method to perform image registration for prostate cancer care by urologists and radiation oncologists now.
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Próstata , Neoplasias de la Próstata , Masculino , Humanos , Próstata/diagnóstico por imagen , Próstata/cirugía , Tomografía Computarizada por Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X/métodos , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/cirugía , PelvisRESUMEN
Membrane contact sites (MCS) are crucial for nonvesicular trafficking-based interorganelle communication. Endoplasmic reticulum (ER)-organelle tethering occurs in part through the interaction of the ER resident protein VAP with FFAT motif-containing proteins. FFAT motifs are characterized by a seven amino acidic core surrounded by acid tracks. We have previously shown that the human intracellular bacterial pathogen Chlamydia trachomatis establishes MCS between its vacuole (the inclusion) and the ER through expression of a bacterial tether, IncV, displaying molecular mimicry of eukaryotic FFAT motif cores. Here, we show that multiple layers of host cell kinase-mediated phosphorylation events govern the assembly of the IncV-VAP tethering complex and the formation of ER-Inclusion MCS. Via a C-terminal region containing three CK2 phosphorylation motifs, IncV recruits CK2 to the inclusion leading to IncV hyperphosphorylation of the noncanonical FFAT motif core and serine-rich tracts immediately upstream of IncV FFAT motif cores. Phosphorylatable serine tracts, rather than genetically encoded acidic tracts, accommodate Type III-mediated translocation of IncV to the inclusion membrane, while achieving full mimicry of FFAT motifs. Thus, regulatory components and post-translational modifications are integral to MCS biology, and intracellular pathogens such as C. trachomatis have evolved complex molecular mimicry of these eukaryotic features.
Asunto(s)
Chlamydia , Proteínas de Transporte Vesicular , Secuencias de Aminoácidos , Chlamydia/metabolismo , Retículo Endoplásmico/metabolismo , Humanos , Proteínas de la Membrana/metabolismo , Unión Proteica , Serina/metabolismo , Proteínas de Transporte Vesicular/metabolismoRESUMEN
To address the increasing demand for safe and effective treatment options for pelvic organ prolapse (POP) due to the worldwide ban of the traditional polypropylene meshes, this study introduced degradable polycaprolactone (PCL)/polyethylene glycol (PEG) composite meshes fabricated with melt-electrowriting (MEW). Two PCL/PEG mesh groups: 90:10 and 75:25 (PCL:PEG, wt%) were fabricated and characterized for their degradation rate and mechanical properties, with PCL meshes used as a control. The PCL/PEG composites showed controllable degradation rates by adjusting the PEG content and produced mechanical properties, such as maximal forces, that were higher than PCL alone. The antibacterial properties of the meshes were elicited by coating them with a commonly used antibiotic: azithromycin. Two dosage levels were used for the coating: 0.5 mg and 1 mg per mesh, and both dosage levels were found to be effective in suppressing the growth of S. aureus bacteria. The biocompatibility of the meshes was assessed using human immortalized adipose derived mesenchymal stem cells (hMSC). In vitro assays were used to assess the cell viability (LIVE/DEAD assay), cell metabolic activity (alamarBlue assay) and cell morphology on the meshes (fluorescent and electron microscopy). The cell attachment was found to decrease with increased PEG content. The freshly drug-coated meshes showed signs of cytotoxicity during the cell study process. However, when pre-released for 14 days in phosphate buffered saline, the initial delay in cell attachment on the drug-coated mesh groups showed full recovery at the 14-day cell culture time point. These results indicated that the PCL/PEG meshes with antibiotics coating will be an effective anti-infectious device when first implanted into the patients, and, after about 2 weeks of drug release, the mesh will be supporting cell attachment and proliferation. These meshes demonstrated a potential effective treatment option for POP that may circumvent the issues related to the traditional polypropylene meshes.
RESUMEN
BACKGROUND: Cannabis use among reproductive-aged Canadians is increasing, but our understanding of its impacts on fertility, pregnancy, and breast milk is still evolving. Despite the availability of many web-based resources, informed decision-making and patient counseling are challenging for expectant families and providers alike. OBJECTIVE: We aimed to conduct a scoping review of publicly available web-based Canadian resources to provide information on the effects of cannabis on fertility, pregnancy, and breast milk. METHODS: Following PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews), we systematically searched 8 databases between January 1, 2010, and November 30, 2020, and web pages of 71 Canadian obstetrical, government, and public health organizations. We included English resources discussing the effects of cannabis on fertility, pregnancy, breastfeeding, or the exposed fetus and infant. Epidemiological characteristics, readability, and content information were extracted and summarized. RESULTS: A total of 183 resources met our inclusion criteria. Resources included content for public audiences (163/183, 89.1%) and health care providers (HCPs; 31/183, 16.9%). The resources were authored by national-level (46/183, 25.1%), provincial or territorial (65/183, 35.5%), and regional (72/183, 39.3%) organizations. All provinces and territories had at least one resource attributed to them. The majority (125/183, 68.3%) were written at a >10 grade reading level, and a few (7/183, 3.8%) were available in languages other than English or French. The breadth of content on fertility (55/183, 30.1%), pregnancy (173/183, 94.5%), and breast milk or breastfeeding (133/183, 72.7%) varied across resources. Common themes included citing a need for more research into the effects of cannabis on reproductive health and recommending that patients avoid or discontinue cannabis use. Although resources for providers were consistent in recommending patient counseling, resources targeting the public were less likely to encourage seeking advice from HCPs (23/163, 14.1%). CONCLUSIONS: Canadian resources consistently identify that there is no known safe amount of cannabis that can be consumed in the context of fertility, pregnancy, and breastfeeding. Areas of improvement include increasing readability and language accessibility and encouraging bidirectional communication between HCPs and patients. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1136/bmjopen-2020-045006.