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AIMS: High-quality evidence is lacking for the impact on healthcare utilisation of short-stay alternatives to psychiatric inpatient services for people experiencing acute and/or complex mental health crises (known in England as psychiatric decision units [PDUs]). We assessed the extent to which changes in psychiatric hospital and emergency department (ED) activity were explained by implementation of PDUs in England using a quasi-experimental approach. METHODS: We conducted an interrupted time series (ITS) analysis of weekly aggregated data pre- and post-PDU implementation in one rural and two urban sites using segmented regression, adjusting for temporal and seasonal trends. Primary outcomes were changes in the number of voluntary inpatient admissions to (acute) adult psychiatric wards and number of ED adult mental health-related attendances in the 24 months post-PDU implementation compared to that in the 24 months pre-PDU implementation. RESULTS: The two PDUs (one urban and one rural) with longer (average) stays and high staff-to-patient ratios observed post-PDU decreases in the pattern of weekly voluntary psychiatric admissions relative to pre-PDU trend (Rural: -0.45%/week, 95% confidence interval [CI] = -0.78%, -0.12%; Urban: -0.49%/week, 95% CI = -0.73%, -0.25%); PDU implementation in each was associated with an estimated 35-38% reduction in total voluntary admissions in the post-PDU period. The (urban) PDU with the highest throughput, lowest staff-to-patient ratio and shortest average stay observed a 20% (-20.4%, CI = -29.7%, -10.0%) level reduction in mental health-related ED attendances post-PDU, although there was little impact on long-term trend. Pooled analyses across sites indicated a significant reduction in the number of voluntary admissions following PDU implementation (-16.6%, 95% CI = -23.9%, -8.5%) but no significant (long-term) trend change (-0.20%/week, 95% CI = -0.74%, 0.34%) and no short- (-2.8%, 95% CI = -19.3%, 17.0%) or long-term (0.08%/week, 95% CI = -0.13, 0.28%) effects on mental health-related ED attendances. Findings were largely unchanged in secondary (ITS) analyses that considered the introduction of other service initiatives in the study period. CONCLUSIONS: The introduction of PDUs was associated with an immediate reduction of voluntary psychiatric inpatient admissions. The extent to which PDUs change long-term trends of voluntary psychiatric admissions or impact on psychiatric presentations at ED may be linked to their configuration. PDUs with a large capacity, short length of stay and low staff-to-patient ratio can positively impact ED mental health presentations, while PDUs with longer length of stay and higher staff-to-patient ratios have potential to reduce voluntary psychiatric admissions over an extended period. Taken as a whole, our analyses suggest that when establishing a PDU, consideration of the primary crisis-care need that underlies the creation of the unit is key.
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Pacientes Internos , Salud Mental , Adulto , Humanos , Análisis de Series de Tiempo Interrumpido , Ciudades , Inglaterra , Servicio de Urgencia en HospitalRESUMEN
PURPOSE: Evidence suggests that the distinctive relational qualities of peer support-compared to clinical-patient relationships-can be eroded in regulated healthcare environments. Measurement of fidelity in trials of peer support is lacking. This paper reports the development and testing of a fidelity index for one-to-one peer support in mental health services, designed to assess fidelity to principles that characterise the distinctiveness of peer support. METHODS: A draft index was developed using expert panels of service user researchers and people doing peer support, informed by an evidence-based, peer support principles framework. Two rounds of testing took place in 24 mental health services providing peer support in a range of settings. Fidelity was assessed through interviews with peer workers, their supervisors and people receiving peer support. Responses were tested for spread and internal consistency, independently double rated for inter-rater reliability, with feedback from interviewees and service user researchers used to refine the index. RESULTS: A fidelity index for one-to-one peer support in mental health services was produced with good psychometric properties. Fidelity is assessed in four principle-based domains; building trusting relationships based on shared lived experience; reciprocity and mutuality; leadership, choice and control; building strengths and making connections to community. CONCLUSIONS: The index offers potential to improve the evidence base for peer support in mental health services, enabling future trials to assess fidelity of interventions to peer support principles, and service providers a means of ensuring that peer support retains its distinctive qualities as it is introduced into mental health services.
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Trastornos Mentales , Servicios de Salud Mental , Consejo , Humanos , Trastornos Mentales/terapia , Grupo Paritario , Psicometría , Reproducibilidad de los ResultadosRESUMEN
AIMS: Family carers supporting an individual with psychosis often experience poorer mental health, however, little is known about specific risk factors among these carers. We investigated the associations between demographic, caregiving characteristics and mental health outcomes in family carers supporting an individual with psychosis and compared carers' outcomes with general population norms. METHODS: We analysed baseline data from the COPe-support randomised controlled trial of online psychoeducation and peer support for adult carers supporting an individual with psychosis between 2018 and 2020. We collected carers' demographic and health outcome data, including wellbeing using Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS as primary outcome), quality of life using EQ-5D-5L and caregiving experience assessed with Experience of Caregiving Inventory. We tested associations between carers' demographic and caregiving characteristics for each outcome in turn and meta-analysed carers' WEMWBS and EQ-5D-5L with Health Survey England (HSE) general population data from 2016 and 2017, respectively. RESULTS: The 407 carers of people with psychosis had a mean WEMWBS score of 42.2 (s.d. 9.21) and their overall weighted pooled WEMWBS score was 7.3 (95% confidence interval (CI) -8.6 to -6.0, p < 0.01) lower than the HSE general population sample, indicating carers have poorer mental wellbeing by more than double the minimum clinically important difference of 3 points on WEMWBS. Among all caring relationships, partners had poorer wellbeing compared to parents with lower WEMWBS score (-6.8, -16.9 to 3.3, p = 0.03). Single carers had significantly poorer wellbeing (-3.6, -5.6 to -1.5, p < 0.01) and a more negative caregiving experience than those who were cohabiting. Spending more than 35 h per week caregiving increased carers' negative experience significantly (p = 0.01). CONCLUSION: Carers of people with psychosis have poorer mental health than non-carers. Partners, lone carers and those spending more than 35 h per week on caring were found to be most at risk of poor mental health. Based on the results, we advocate that the details of carers for individuals with psychosis should be added to the existing carers or severe mental illness registers at all general practitioner surgeries and for their wellbeing screened routinely. Future large-scale prospective studies are needed to develop a predictive model to determine risk factors, hence to aid early identification of carers' support needs. Such understandings are also useful to inform tailored intervention development.
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Cuidadores/psicología , Familia/psicología , Salud Mental/estadística & datos numéricos , Trastornos Psicóticos/psicología , Calidad de Vida/psicología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
BACKGROUND: The UK mental health system is stretched to breaking point. Individuals presenting with mental health problems wait longer at the ED than those presenting with physical concerns and finding a bed when needed is difficult - 91% of psychiatric wards are operating at above the recommended occupancy rate. To address the pressure, a new type of facility - psychiatric decision units (also known as mental health decision units) - have been introduced in some areas. These are short-stay facilities, available upon referral, targeted to help individuals who may be able to avoid an inpatient admission or lengthy ED visit. To advance knowledge about the effectiveness of this service for this purpose, we will examine the effect of the service on the mental health crisis care pathway over a 4-year time period; the 2 years proceeding and following the introduction of the service. We use aggregate service level data of key indicators of the performance of this pathway. METHODS: Data from four mental health Trusts in England will be analysed using an interrupted time series (ITS) design with the primary outcomes of the rate of (i) ED psychiatric presentations and (ii) voluntary admissions to mental health wards. This will be supplemented with a synthetic control study with the same primary outcomes, in which a comparable control group is generated for each outcome using a donor pool of suitable National Health Service Trusts in England. The methods are well suited to an evaluation of an intervention at a service delivery level targeting population-level health outcome and the randomisation or 'trialability' of the intervention is limited. The synthetic control study controls for national trends over time, increasing our confidence in the results. The study has been designed and will be carried out with the involvement of service users and carers. DISCUSSION: This will be the first formal evaluation of psychiatric decision units in England. The analysis will provide estimates of the effect of the decision units on a number of important service use indicators, providing much-needed information for those designing service pathways. TRIAL REGISTRATION: primary registry: isrctn.com Identifying number: ISRCTN77588384 Link: Date of registration in primary registry: 27/02/2020. PRIMARY SPONSOR: St George's, University of London, Cramner Road, Tooting, SW17 ORE. Primary contact: Joe Montebello.
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Toma de Decisiones Clínicas , Análisis de Series de Tiempo Interrumpido/métodos , Trastornos Mentales/terapia , Salud Mental , Inglaterra , Humanos , Admisión del Paciente , Medicina EstatalRESUMEN
STUDY DESIGN: Cross-sectional repeated measures. OBJECTIVES: To quantify the effects of posture and measurement site on the inter-recti distance (IRD) and investigate the reliability of IRD measurement using ultrasound imaging in different postures. BACKGROUND: The linea alba connects the rectus abdominis muscles anteriorly and the width is known as the IRD. The IRD is usually measured in crook-lying and is the primary outcome measure to assess for a divarication of recti abdominis (DRA). The effects of posture and measurement site on the IRD have not been investigated. METHODS: Ultrasound imaging was used to measure IRD in 41 women ≥8 weeks postpartum. The IRD was measured at three sites (superior-umbilicus, umbilicus and inferior-umbilicus), in three postures (crook-lying, sitting and standing), and repeated one-week later. The effects of posture and site were investigated using one-way ANOVAs. Reliability was analysed using Intraclass correlation coefficients (ICCs), Bland Altman analyses, standard error of measurement and minimal detectable change. RESULTS: The IRD was wider when standing vs. lying at both the superior-umbilicus and umbilicus by 0.30 cm (95% CI 0.21 to 0.39) and 0.20 cm (0.11-0.30) respectively (p < 0.001). Measurements at the inferior-umbilicus were, on average, 1.6 and 2.1 cm narrower than superior-umbilicus and umbilicus sites, respectively (p < 0.001). There was high intra-rater reliability within-session (ICC3.3) and between-session (ICC3.1) at all sites measured. CONCLUSION: The IRD can be measured reliably at all sites and postures. The IRD is wider at superior-umbilicus and umbilicus when upright compared with lying. There is a difference in IRD between all sites measured.
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Periodo Posparto , Postura/fisiología , Recto del Abdomen/citología , Recto del Abdomen/diagnóstico por imagen , Adulto , Estudios Transversales , Femenino , Humanos , Persona de Mediana Edad , Recto del Abdomen/fisiología , Reproducibilidad de los Resultados , UltrasonografíaRESUMEN
AIMS: A range of peer worker roles are being introduced into mental health services internationally. There is some evidence that attests to the benefits of peer workers for the people they support but formal trial evidence in inconclusive, in part because the change model underpinning peer support-based interventions is underdeveloped. Complex intervention evaluation guidance suggests that understandings of how an intervention is associated with change in outcomes should be modelled, theoretically and empirically, before the intervention can be robustly evaluated. This paper aims to model the change mechanisms underlying peer worker interventions. METHODS: In a qualitative, comparative case study of ten peer worker initiatives in statutory and voluntary sector mental health services in England in-depth interviews were carried out with 71 peer workers, service users, staff and managers, exploring their experiences of peer working. Using a Grounded Theory approach we identified core processes within the peer worker role that were productive of change for service users supported by peer workers. RESULTS: Key change mechanisms were: (i) building trusting relationships based on shared lived experience; (ii) role-modelling individual recovery and living well with mental health problems; (iii) engaging service users with mental health services and the community. Mechanisms could be further explained by theoretical literature on role-modelling and relationship in mental health services. We were able to model process and downstream outcomes potentially associated with peer worker interventions. CONCLUSIONS: An empirically and theoretically grounded change model can be articulated that usefully informs the development, evaluation and planning of peer worker interventions.
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This paper describes key components of a mental health practice development training programme, which aimed to translate into practice a deeper, more evidence-based understanding of the lived experience of service users detained under the Mental Health Act (1983/2007), using action research as the underpinning paradigm. The programme explored the myriad applications of the six categories of intervention initially proposed by Heron and the widespread applicability of solution-focused brief therapy. The programme evaluation used open-ended questionnaires in order to obtain participants' views on facilitation and workshop content, in addition to two focus groups. The aim of the evaluation was to provide insight into participants' experience of the programme. Feedback from participants reflected a high degree of skill acquisition and enhancement and a noticeable change in ward culture after completing the programme. Service user researchers were intimately involved during all stages of the design, implementation and analysis including service user interviews for Phase 1 and the education intervention element of the practice development programme. Implications for evidence-based mental health nursing practice, service user involvement in research and directions for future research are discussed.
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Personal de Salud/educación , Hospitales Psiquiátricos/normas , Competencia Profesional/normas , Desarrollo de Programa/normas , Evaluación de Programas y Proyectos de Salud/normas , Adulto , Grupos Focales , HumanosRESUMEN
Section 136 of the Mental Health Act 1983 (amended) provides police officers in the United Kingdom with the authority to remove individuals who appear to be suffering from a mental illness from any public place to a designated 'place of safety' for appropriate assessment. A considerable amount of research has been dedicated to investigate who is detained under this section and how it is implemented. A review of the literature revealed a high prevalence of schizophrenia, personality disorders and mania in individuals detained under Section 136 and an over-representation of black detainees. Several studies also reported poor communication between different agencies and poor levels of knowledge regarding the implementation of the section. There is a lack of qualitative research exploring detainee and professional experience of Section 136 and in particular the patient pathway to mental health care via Section 136 experienced by black detainees. Implications for clinical practice, multi-agency collaboration and future research are discussed.
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Internamiento Obligatorio del Enfermo Mental/legislación & jurisprudencia , Policia , Humanos , Trastornos Mentales/diagnóstico , Trastornos Mentales/epidemiología , Competencia Profesional , Clase Social , Reino UnidoRESUMEN
The work-up of renovascular hypertension (10% of children hypertension cases) benefits from multiple imaging modalities. These two cases show the difficulties encountered with infant and underscore "the major role" of the computed tomography angiography within for diagnosis and management. Indeed CTA allows reproducible studies of abdominal vessels at the expense of radiation exposure.
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Hipertensión Renovascular/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Femenino , Humanos , Lactante , MasculinoRESUMEN
The current management of psoriasis and its associated resource use in the United Kingdom (UK) was investigated in this retrospective analysis of 789,300 primary care patient records. Most patients with psoriasis (94%) were managed on topical psoriasis agents only, 4% were prescribed systemic psoriasis agents and 2% had no recorded psoriasis treatment at all during the 12-month study period. Co-medications to treat physical or psychological comorbidities were required by 22% of patients. Referral rates into secondary care were low, 5% of patients prescribed systemic psoriasis agents and 0.7% of patients prescribed topical psoriasis agents had secondary care appointments documented in their medical records. This study demonstrates that most patients with psoriasis in UK primary care are managed on topical agents even though there are surrogate markers, such as resource use and co-medication prescriptions, which indicate that their psoriasis is not optimally controlled.
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Fármacos Dermatológicos/administración & dosificación , Atención Primaria de Salud/estadística & datos numéricos , Psoriasis/tratamiento farmacológico , Administración Cutánea , Adolescente , Adulto , Anciano , Niño , Preescolar , Prescripciones de Medicamentos/estadística & datos numéricos , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Polifarmacia , Pautas de la Práctica en Medicina/estadística & datos numéricos , Estudios Retrospectivos , Reino UnidoRESUMEN
Human immunodeficiency virus-1 (HIV-1) infection is associated with numerous effects on the nervous system, including pain and peripheral neuropathies. We now demonstrate that cultured rat dorsal root ganglion (DRG) neurons express a wide variety of chemokine receptors, including those that are thought to act as receptors for the HIV-1 coat protein glycoprotein120 (gp120). Chemokines that activate all of the known chemokine receptors increased [Ca(2+)](i) in subsets of cultured DRG cells. Many neurons responded to multiple chemokines and also to bradykinin, ATP, and capsaicin. Immunohistochemical studies demonstrated the expression of the CXCR4 and CCR4 chemokine receptors on populations of DRG neurons that also expressed substance P and the VR1 vanilloid receptor. RT-PCR analysis confirmed the expression of CXCR4, CX3CR1, CCR4, and CCR5 mRNAs in DRG neurons. Chemokines and gp120 produced excitatory effects on DRG neurons and also stimulated the release of substance P. Chemokines and gp120 also produced allodynia after injection into the rat paw. Thus these results provide evidence that chemokines and gp120 may produce painful effects via direct actions on chemokine receptors expressed by nociceptive neurons. Chemokine receptor antagonists may be important therapeutic interventions in the pain that is associated with HIV-1 infection and inflammation.
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Quimiocinas/metabolismo , Proteína gp120 de Envoltorio del VIH/farmacología , Hiperalgesia/fisiopatología , Neuronas/metabolismo , Nociceptores/metabolismo , Adenosina Trifosfato/metabolismo , Adenosina Trifosfato/farmacología , Animales , Bradiquinina/farmacología , Calcio/metabolismo , Capsaicina/farmacología , Células Cultivadas , Quimiocinas/farmacología , Colorantes Fluorescentes , Ganglios Espinales/citología , Ganglios Espinales/efectos de los fármacos , Ganglios Espinales/metabolismo , Hiperalgesia/inducido químicamente , Inflamación/metabolismo , Líquido Intracelular/metabolismo , Masculino , Neuronas/citología , Neuronas/efectos de los fármacos , Nociceptores/citología , Nociceptores/efectos de los fármacos , ARN Mensajero/biosíntesis , Ratas , Ratas Sprague-Dawley , Receptores CCR4 , Receptores CXCR4/biosíntesis , Receptores de Quimiocina/biosíntesis , Receptores de Quimiocina/genética , Receptores de Quimiocina/metabolismo , Sustancia P/metabolismoRESUMEN
It has been hypothesized that R-type Ca currents result from the expression of the alpha(1E) gene. To test this hypothesis we examined the properties of voltage-dependent Ca channels in mice in which the alpha(1E) Ca channel subunit had been deleted. Application of omega-conotoxin GVIA, omega-agatoxin IVA, and nimodipine to cultured cerebellar granule neurons from wild-type mice inhibited components of the whole-cell Ba current, leaving a "residual" R current with an amplitude of approximately 30% of the total Ba current. A minor portion of this R current was inhibited by the alpha(1E)-selective toxin SNX-482, indicating that it resulted from the expression of alpha(1E). However, the majority of the R current was not inhibited by SNX-482. The SNX-482-sensitive portion of the granule cell R current was absent from alpha(1E) knock-out mice. We also identified a subpopulation of dorsal root ganglion (DRG) neurons from wild-type mice that expressed an SNX-482-sensitive component of the R current. However as with granule cells, most of the DRG R current was not blocked by SNX-482. We conclude that there exists a component of the R current that results from the expression of the alpha(1E) Ca channel subunit but that the majority of R currents must result from the expression of other Ca channel alpha subunits.
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Canales de Calcio Tipo R/genética , Canales de Calcio Tipo R/metabolismo , Animales , Bario/farmacología , Western Blotting , Calcio/metabolismo , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio Tipo R/efectos de los fármacos , Supervivencia Celular/genética , Células Cultivadas , Cerebelo/citología , Cerebelo/efectos de los fármacos , Cerebelo/metabolismo , Electrofisiología , Ganglios Espinales/citología , Ganglios Espinales/efectos de los fármacos , Ganglios Espinales/metabolismo , Transporte Iónico/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neuronas/citología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Nimodipina/farmacología , Técnicas de Placa-Clamp , Subunidades de Proteína , Venenos de Araña/farmacología , Transmisión Sináptica/efectos de los fármacos , omega-Agatoxina IVA/farmacología , omega-Conotoxina GVIA/farmacologíaAsunto(s)
Canales Iónicos/efectos de los fármacos , Neuronas/fisiología , Oligonucleótidos Antisentido/farmacología , Animales , Portadores de Fármacos , Diseño de Fármacos , Expresión Génica/efectos de los fármacos , Inmunohistoquímica , Hibridación in Situ , Canales Iónicos/genética , Oligonucleótidos Antisentido/síntesis química , Oocitos , Biosíntesis de Proteínas/efectos de los fármacos , Tionucleótidos/síntesis química , Tionucleótidos/farmacología , Transfección , XenopusRESUMEN
The pharmacological properties of voltage-dependent calcium channel (VDCC) subtypes appear mainly to be determined by the alpha1 pore-forming subunit but, whether P-and Q-type VDCCs are encoded by the same alpha1 gene presently is unresolved. To investigate this, we used IgG antibodies to presynaptic VDCCs at motor nerve terminals that underlie muscle weakness in the autoimmune Lambert-Eaton myasthenic syndrome (LEMS). We first studied their action on changes in intracellular free Ca2+ concentration [Ca2+]i in human embryonic kidney (HEK293) cell lines expressing different combinations of human recombinant VDCC subunits. Incubation for 18 h with LEMS IgG (2 mg/ml) caused a significant dose-dependent reduction in the K+-stimulated [Ca2+]i increase in the alpha1A cell line but not in the alpha1B, alpha1C, alpha1D, and alpha1E cell lines, establishing the alpha1A subunit as the target for these autoantibodies. Exploiting this specificity, we incubated cultured rat cerebellar neurones with LEMS IgG and observed a reduction in P-type current in Purkinje cells and both P- and Q-type currents in granule cells. These data are consistent with the hypothesis that the alpha1A gene encodes for the pore-forming subunit of both P-type and Q-type VDCCs.
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Autoanticuerpos/inmunología , Autoanticuerpos/farmacología , Canales de Calcio/inmunología , Calcio/metabolismo , Cerebelo/fisiología , Animales , Canales de Calcio/efectos de los fármacos , Línea Celular , Electrofisiología , Humanos , Transporte Iónico/efectos de los fármacos , Transporte Iónico/inmunología , Síndrome Miasténico de Lambert-Eaton/inmunología , Ratas , Proteínas Recombinantes/inmunología , TransfecciónRESUMEN
Neuronal voltage-dependent calcium channels (VDCCs) each comprising of alpha 1, alpha 2 delta, and beta subunits, are one mechanism by which excitable cells regulate the flux of calcium ions across the cell membrane following depolarisation Studies have shown the expression of several alpha 1 and beta subtypes within neuronal tissue. The comparative distribution of these in normal human brain is largely unknown. The aim of this work is to prepare antibodies directed specifically to selected subunits of human neuronal VDCCs for use in biochemical and mapping studies of calcium channel subtypes in the brain. Previous studies have defined DNA sequences specific for each subunit Comparison of these sequences allows the selection of unique amino acid sequences for use as immunogens which are prepared as glutathione-S-transferase (GST) fusion proteins in E. coli. Polyclonal antibodies raised against these fusion proteins are purified by Protein A chromatography, followed by immunoaffinity chromatography and extensive adsorptions using the appropriate fusion protein-GST Sepharose 4B columns. The resultant antibodies are analysed for specificity against the fusion proteins by ELISA, and by immunofluorescence and Western immunoblot analysis of recombinant HEK293 cells stably transfected with cDNAs encoding alpha 1, alpha 2 delta and beta subunits.
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Anticuerpos/inmunología , Anticuerpos/aislamiento & purificación , Canales de Calcio/inmunología , Canales de Calcio/fisiología , Neuronas/metabolismo , Animales , Especificidad de Anticuerpos , Antígenos/inmunología , Western Blotting , Línea Celular , Electrofisiología , Ensayo de Inmunoadsorción Enzimática , Escherichia coli/metabolismo , Técnica del Anticuerpo Fluorescente , Humanos , Inmunización , Conejos , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/metabolismoRESUMEN
We examined the ability of different G protein subunits to inhibit the activity of human alpha1B and alpha1E Ca2+ channels stably expressed in human embryonic kidney (HEK) 293 cells together with beta1B and alpha2Bdelta Ca2+ channel subunits. Under normal conditions, Ca2+ currents in alpha1B-expressing cells showed little facilitation after a depolarizing prepulse. However, when we overexpressed the beta2gamma2 subunits of heterotrimeric G proteins, the time course of activation of the Ca2+ currents was considerably slowed and a depolarizing prepulse produced a large facilitation of the current as well as an acceleration in its time course of activation. Similar effects were not observed when cells were transfected with constitutively active mutants of the G protein alpha subunits alpha s, alpha i1, and alpha o or with the G protein beta2 and gamma2 subunits alone. Studies carried out in cells expressing alpha1E currents showed that overexpression of beta2gamma2 subunits produced pre-pulse facilitation, although this was of lesser magnitude than that observed with Ca2+ currents in alpha1B-expressing cells. The subunits beta2 and gamma2 alone produced no effects, nor did constitutively active alpha s, alpha i1, and alpha o subunits. Phorbol esters enhanced alpha1E Ca2+ currents but had no effect on alpha1B currents, suggesting that protein kinase C activation was not responsible for the observed effects. When alpha1E Ca2+ currents were expressed without their beta subunits, they exhibited prepulse facilitation. These results demonstrate that alpha1E Ca2+ currents are less susceptible to direct modulation by G proteins than alpha1B currents and illustrate the antagonistic interactions between Ca2+ channel beta subunits and G proteins.
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Canales de Calcio/fisiología , Proteínas de Unión al GTP/fisiología , Neuronas/fisiología , Línea Celular , Humanos , Activación del Canal Iónico , Técnicas de Placa-Clamp , Proteínas Recombinantes , Relación Estructura-Actividad , TransfecciónRESUMEN
Treatment of cerebellar neurones in culture with an antisense oligonucleotide (ODN) against alpha1A, reduced the whole-cell P-type calcium channel current relative to mismatch ODN treated controls (p < 0.001). Therefore, AgaIVA (50 nM) reduced whole-cell calcium current in mismatch and antisense treated cells by 70 +/- 4 and 19 +/- 3%, respectively.
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Canales de Calcio/efectos de los fármacos , Cerebelo/efectos de los fármacos , Oligonucleótidos Antisentido/farmacología , Células de Purkinje/efectos de los fármacos , Animales , Células Cultivadas/efectos de los fármacos , Femenino , Inmunohistoquímica , Ratones , Ratones Endogámicos BALB C , Embarazo , Ratas , Ratas WistarRESUMEN
This report describes a suitable model for analysing heterogeneous T cell responses to complex foreign antigens using coated polystyrene beads. The advantage of this technique is that it allows the simple removal of detergents from bound antigen so that biochemically separated antigens or crude antigen mixtures can be used. Furthermore, due to the enhanced uptake of latex-bound antigens by phagocytic antigen-presenting cells (APC), very small amounts of antigen will suffice for activation of T cells in vitro. The potential use of this technique to analyse relevant T cell responses to antigens which are difficult to obtain purified in bulk quantities, is discussed.
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Técnicas Inmunológicas , Activación de Linfocitos , Linfocitos T/inmunología , Animales , Células Presentadoras de Antígenos/inmunología , Antígenos/inmunología , Antígenos/aislamiento & purificación , Detergentes/farmacología , Femenino , Látex , Ratones , Ratones Endogámicos BALB C/inmunología , Ratones Endogámicos C57BL/inmunología , Microesferas , Fagocitosis , PoliestirenosRESUMEN
We have studied the role of CD4+ T cells in the immune response to Plasmodium chabaudi chabaudi. From in vivo experiments in which the different subsets of T cells were depleted, it is clear that CD4+ T cells are essential for the generation of protective immunity. Our limiting dilution analysis show that the CD4 T-cell response to P. chabaudi antigens is heterogeneous, in that distinct functions can be performed by different responding T cells, and these responses change during infection. During the first phase of the infection the predominant response is that of a TH1-type cell, producing IL-2 and IFN-gamma. This correlates with the appearance of IFN-gamma in the serum of infected animals. After the clearance of the acute parasitemia, i.e. in the second phase of the infection, the specific response is characterised by TH2 cells, which are effective helper cells for antibody production and presumably are necessary for the switch of IgM to IgG. CD4+ T cells are effector cells are not necessary in the second phase of the infection; mice which have been depleted of CD4+ T cells at this time are able to control their infection in a manner similar to untreated mice. This ability to control parasitemia coincides with the production of specific IgG but not IgM antibodies and the predominance of TH2 type helper cells. Therefore, our data suggest that malaria-specific IgG antibodies are important effectors in the second phase of an infection with P. chabaudi chabaudi.