RESUMEN
BACKGROUND: Patients undergoing hematopoietic cell transplantation (HCT) often require use of an unrelated donor or cord blood unit (CBU). An understanding of evolving practices in graft selection is needed for optimization of donor recruitment and cord blood collection. STUDY DESIGN AND METHODS: Each donor workup (WU) requested in 2018 involving a Canadian (CDN) patient and unique donor product or CBU was reviewed (n = 598). Degree of HLA match; product origin (domestic or international [INT]); and non-HLA factors including donor age, sex, cytomegalovirus (CMV), and ABO compatibility were analyzed for WUs that proceeded to transplant (n = 414). We also analyzed changes compared to a similar analysis performed in 2013. RESULTS: The majority of transplants used matched unrelated donors (MUDs; n = 323; 78%) and were most often young (≤35 years), male, INT donors (n = 136). The proportion of transplants involving MUDs, as opposed to mismatched unrelated donors or CBUs, increased by 12.4% compared with 2013. When young, male, CDN MUDs were identified in patient search reports but not selected, CMV mismatching and ABO incompatibility were most likely to have influenced the decision to use an INT MUD. Consistent with global trends, CBU transplants decreased compared to 2013; however, the degree of HLA matching improved significantly, and 27% of transplanted CBUs were procured from the Canadian Blood Services Cord Blood Bank. CONCLUSIONS: Access to MUDs and better HLA-matched CBUs by CDN patients has increased since 2013. Ongoing recruitment of young registrants and cord blood donors with diverse HLA haplotypes will support selection of donors with optimal non-HLA characteristics.
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Trasplante de Células Madre de Sangre del Cordón Umbilical , Antígenos HLA/sangre , Haplotipos , Trasplante de Células Madre Hematopoyéticas , Prueba de Histocompatibilidad , Donante no Emparentado , Aloinjertos , Canadá , Femenino , Sangre Fetal , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Utilization of unrelated donors and cord blood units (CBUs) for allogeneic hematopoietic cell transplantation continues to increase. Understanding the practices of donor selection by transplant centers is critical for unrelated donor registries and cord blood banks to optimize registry composition and inventory to meet patient need. STUDY DESIGN AND METHODS: Unrelated donor and CBU selection practices of Canadian transplant centers served by Canadian Blood Services' OneMatch Stem Cell & Marrow Network (OM) were reviewed, including HLA match level, locus of disparity, age, sex, and product choice (donor vs. CBU). RESULTS: HLA-matched donors within OM and/or international (INT) registries were preferentially investigated, underscoring the primary importance of HLA matching. In the case of HLA-mismatched donors, HLA-A disparities were most common while DRB1 mismatches were least common. Advanced age, sex, and lack of donor availability were the most frequent reasons that high-probability OM donors were overlooked in favor of INT donors. High-probability 10 of 10 HLA-matched female donors from OM were often avoided in favor of INT male donors. Use of female donors, however, increased in cases restricted to more HLA-disparate donor options. Caucasian patients were more likely to find 10 of 10 matched donors, whereas use of mismatched donors and CBUs were more prevalent among non-Caucasian patients. CONCLUSIONS: Recruitment and retention of young, male donors from diverse ethnic backgrounds may increase the usage of histocompatible OM donors for patients in need.
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Selección de Donante , Trasplante de Células Madre Hematopoyéticas , Donante no Emparentado , Adulto , Factores de Edad , Aloinjertos , Canadá , Femenino , Prueba de Histocompatibilidad , Humanos , Masculino , Factores SexualesRESUMEN
BACKGROUND: The platelet (PLT) storage environment triggers the formation of surface-attached aggregates known as biofilms by the common PLT contaminant Staphylococcus epidermidis. The biofilm matrix is largely composed of polysaccharide intercellular adhesin (PIA) mediated by the icaADBC operon. However, PIA-negative S. epidermidis has been reported to form biofilms in PLT concentrates (PCs). Since biofilm formation is associated with increased virulence, this study was aimed at determining if PIA-negative S. epidermidis grown in PCs presents enhanced virulence using the nematode Caenorhabditis elegans as a host model for bacterial pathogenesis. STUDY DESIGN AND METHODS: Biofilm-positive S. epidermidisâ ATCC 35984 and 9142, which carry the icaADBC operon, and biofilm-negative S. epidermidisâ ATCC 12228 and 9142 ΔicaA were grown in regular media and in PCs and biofilm formation was quantified using a crystal violet assay. The virulence of these strains after passage through PCs was tested using nematode killing assays. Nematode survival was calculated using the Kaplan-Meier method and statistical differences were determined by log-rank analysis. RESULTS: All S. epidermidis strains were able to form biofilms in PCs. Although persistence of a biofilm-positive phenotype in the biofilm-negative strains grown in PCs was not observed after passage in regular medium, the virulence of all strains was significantly increased as demonstrated by shortened life spans of the nematodes in C. elegans killing assays. CONCLUSION: Our findings highlight the potential of an increased risk of nosocomial infections caused by S. epidermidis in transfusion recipients since PC storage conditions promote biofilm formation, and possibly pathogenicity, of strains traditionally known to be attenuated for virulence.
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Biopelículas/crecimiento & desarrollo , Plaquetas/microbiología , Caenorhabditis elegans/microbiología , Transfusión de Plaquetas/normas , Infecciones Estafilocócicas/sangre , Staphylococcus epidermidis/patogenicidad , Animales , Proteínas Bacterianas/genética , Bioensayo/métodos , Eliminación de Gen , Humanos , Polisacáridos Bacterianos/metabolismo , Infecciones Estafilocócicas/prevención & control , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/aislamiento & purificación , VirulenciaRESUMEN
BACKGROUND: A one-step skin disinfection method containing 2% chlorhexidine-gluconate (CHG) and 70% isopropyl alcohol (IPA) is currently used by blood suppliers worldwide. Reports of bacterially contaminated platelet concentrates (PCs) indicate that skin disinfection is not fully effective. Approximately 20% of skin microflora exist as surface-attached aggregates (biofilms), known for displaying increased resistance to disinfectants. This study was aimed at determining whether skin microflora biofilm-positive Staphylococcus epidermidis and Staphylococcus capitis are resistant to CHG and/or IPA. STUDY DESIGN AND METHODS: Free-floating cells and mono or dual (1 : 1 ratio) biofilms of S. epidermidis and S. capitis were exposed to CHG, IPA, or CHG/IPA for 30 seconds, simulating skin disinfection practices. Residual viable cells were quantified by colony counting. Morphology of disinfectant-treated S. epidermidis biofilms was examined by scanning electron microscopy. Treated S. epidermidis and S. capitis biofilms were inoculated into PCs and bacterial concentrations were determined on Days 0 and 5 of storage. RESULTS: Treatment of staphylococcal biofilm cells with all disinfectants caused cell damage and significant reduction in viability, with CHG/IPA being the most effective. However, biofilms were significantly more resistant to treatment than free-floating cells. Disinfectant-treated S. epidermidis proliferated better in PCs than S. capitis, especially when grown as monospecies biofilms. CONCLUSION: Although CHG/IPA is effective in reducing the viability of S. epidermidis and S. capitis biofilms, these organisms are not completely eliminated. Furthermore, disinfectant-treated staphylococcal biofilms multiply well in PCs. These results demonstrate that the biofilm-forming capability of the skin microflora reduces the bactericidal efficiency of blood donor skin disinfectants.
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Antiinfecciosos Locales/farmacología , Biopelículas/crecimiento & desarrollo , Donantes de Sangre , Clorhexidina/análogos & derivados , Farmacorresistencia Bacteriana , Piel/microbiología , Staphylococcus epidermidis/fisiología , 2-Propanol , Clorhexidina/farmacología , HumanosRESUMEN
Hematopoietic cell transplantation (HCT) has undergone many advances over the decades. Trends in HCT utilization have been impacted by research based on the data and samples collected by the Center for International Blood and Marrow Transplant Research (CIBMTR). Here, we provide a summary report of the CIBMTR Biorepository resource and describe the biospecimen inventory along with collection and request procedures. The diversity captured in this inventory reflects transplant activity, and these samples can be leveraged for secondary analyses to generate more data and insights to advance the field. We describe how our resources have already impacted HCT practice and elaborate on possibilities for further collaboration and utilization to maximize capabilities and research opportunities. Hematopoietic cell transplant data and biorepository resources at the CIBMTR have been and continue to be leveraged to improve patient outcomes.
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Trasplante de Células Madre Hematopoyéticas , Humanos , Bancos de Muestras Biológicas , Resultado del TratamientoRESUMEN
Proteomic profiling of Alzheimer's disease (AD) brains has identified numerous understudied proteins, including midkine (MDK), that are highly upregulated and correlated with Aß since the early disease stage, but their roles in disease progression are not fully understood. Here we present that MDK attenuates Aß assembly and influences amyloid formation in the 5xFAD amyloidosis mouse model. MDK protein mitigates fibril formation of both Aß40 and Aß42 peptides in Thioflavin T fluorescence assay, circular dichroism, negative stain electron microscopy, and NMR analysis. Knockout of Mdkgene in 5xFAD increases amyloid formation and microglial activation. Further comprehensive mass spectrometry-based profiling of whole proteome and aggregated proteome in these mouse models indicates significant accumulation of Aß and Aß-correlated proteins, along with microglial components. Thus, our structural and mouse model studies reveal a protective role of MDK in counteracting amyloid pathology in Alzheimer's disease.
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BACKGROUND: The electronic health record (EHR) used in the examination room, is becoming the primary method of medical data storage in primary care practice in the USA. One of the challenges in using EHRs is maintaining effective patient-provider communication. Many studies have focused on communication in the examination room. PURPOSE: Scant research exists on the best methods in educating nurse practitioners and other primary care providers (clinicians). The purpose of this study was to explore various health record training programmes for clinicians. METHODS: One researcher participated in and observed three health systems' EHR training programmes for ambulatory care providers in the Pacific Northwest. A focused ethnographic approach was used, emphasising patient-provider communication. RESULTS: Only one system had formalised communication training in their class, the other two systems emphasised only the software and data aspects of the EHR. CONCLUSIONS: The fact that clinicians are expected to use EHRs in the examination room necessitates the inclusion of communication training in EHR training programmes and/or as a part of primary care nurse practitioner education programmes.
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Comunicación , Registros Electrónicos de Salud , Capacitación en Servicio/organización & administración , Atención Primaria de Salud/organización & administración , Relaciones Profesional-Paciente , Actitud hacia los Computadores , Investigación sobre Servicios de Salud , Humanos , Investigación Cualitativa , Estados UnidosRESUMEN
Counseling the periviable pregnant woman presenting at the edge of viability can often be confusing for the patient and frustrating for the clinician. Although neonatal survival rates have improved dramatically over the last few decades, severe morbidity is still common. This is further complicated by the fact that the information provided to the parents regarding the outcomes may not be up to date or completely accurate. The counseling is also frequently influenced by personal beliefs and biases of the medical staff. An evidence-based approach may improve the experience for both the expectant parents and the health care team.
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Toma de Decisiones , Viabilidad Fetal/fisiología , Recien Nacido Prematuro/fisiología , Incertidumbre , Medicina Basada en la Evidencia , Femenino , Humanos , Recién Nacido , Cuidado Intensivo Neonatal , Relaciones Médico-Paciente , EmbarazoRESUMEN
BACKGROUND: During postpartum hospitalization, close physical interactions between mother and newborn facilitate attachment, breastfeeding, and relationship competence. The challenge during this time is to support these important interactions in the hospital while ensuring the safety of the newborn. A literature review indicated that newborn "falls" and drops--collectively referred to as falls-remains largely unaddressed. Experience of a seven-hospital system in Oregon offers a template for understanding how and why infant falls occur in hospitals and how to address the issue. IDENTIFYING THE PROBLEM: For a two-year period (January 2006-December 2007), a query of a live voluntary event database yielded 9 cases of newborn falls (from 22,866 births), for a rate of 3.94 falls per 10,000 births. RESPONDING TO NEWBORN FALLS: A newborn falls committee made preliminary recommendations for interventions to reduce newborn falls, including (1) expanding thel patient safety contract, (2) monitoring mothers more closely, (3) improving equipment safety, and (4) spreading information about newborn falls within the state and throughout the hospital system. For example, staff use the patient safety contract to improve awareness and prevention of falls. The mothers and significant family members are asked to review the safety information and sign the contract. CONCLUSION: Newborns experience in-hospital falls at a rate of approximately 1.6-4.14/10,000 live births, resulting in an estimated 600-1600 falls per year in the United States. Additional reports of rates of newborn falls are urgently needed to determine the true prevalence of this historically underreported event. Standardized evaluation and management guidelines need to be developed to aid the clinician in the appropriate care of newborns experiencing this infrequent event.
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Accidentes por Caídas/prevención & control , Administración Hospitalaria/métodos , Atención Posnatal/métodos , Calidad de la Atención de Salud/organización & administración , Administración de la Seguridad/métodos , Seguridad de Equipos , Humanos , Recién Nacido , Estudios de Casos OrganizacionalesRESUMEN
This study estimates excess cost and length of stay associated with voluntary patient safety event reports at 3 hospitals. Voluntary patient safety event reporting has proliferated in hospitals in recent years, yet little is known about the cost of events captured by this type of system. Events captured in an electronic reporting system at 3 urban community hospitals in Portland, Oregon, are evaluated. Cost and length of stay are assessed by linking event reports to risk-adjusted administrative data. Hospital stays with an event report are 17% more costly and 22% longer than stays without events. Medication and treatment errors are the most expensive and most common events, representing 77% of all event types and 77% of added costs. Ninety percent of events result in no measurable harm. Patient safety events captured by voluntary event reporting reflect significant waste and inefficiency in hospital stays.
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Hospitales , Tiempo de Internación , Gestión de Riesgos/métodos , Administración de la Seguridad , Costos y Análisis de Costo , Humanos , Errores Médicos/economía , Errores de Medicación/economía , OregonRESUMEN
More than 8,000 genes are turned on or off as progenitor cells produce the 7 classes of retinal cell types during development. Thousands of enhancers are also active in the developing retinae, many having features of cell- and developmental stage-specific activity. We studied dynamic changes in the 3D chromatin landscape important for precisely orchestrated changes in gene expression during retinal development by ultra-deep in situ Hi-C analysis on murine retinae. We identified developmental-stage-specific changes in chromatin compartments and enhancer-promoter interactions. We developed a machine learning-based algorithm to map euchromatin and heterochromatin domains genome-wide and overlaid it with chromatin compartments identified by Hi-C. Single-cell ATAC-seq and RNA-seq were integrated with our Hi-C and previous ChIP-seq data to identify cell- and developmental-stage-specific super-enhancers (SEs). We identified a bipolar neuron-specific core regulatory circuit SE upstream of Vsx2, whose deletion in mice led to the loss of bipolar neurons.
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Eucromatina/metabolismo , Regulación del Desarrollo de la Expresión Génica/fisiología , Heterocromatina/metabolismo , Retina/embriología , Células Bipolares de la Retina/metabolismo , Animales , Cromatina/metabolismo , Secuenciación de Inmunoprecipitación de Cromatina , Elementos de Facilitación Genéticos , Redes Reguladoras de Genes , Proteínas de Homeodominio/genética , Aprendizaje Automático , Ratones , Lámina Nuclear/metabolismo , Regiones Promotoras Genéticas , RNA-Seq , Receptores Citoplasmáticos y Nucleares/genética , Retina/citología , Retina/metabolismo , Retina/ultraestructura , Células Bipolares de la Retina/citología , Células Fotorreceptoras Retinianas Bastones/citología , Células Fotorreceptoras Retinianas Bastones/metabolismo , Análisis de la Célula Individual , Factores de Transcripción/genética , Receptor de Lamina BRESUMEN
A Wave-II Paul Coverdell Prototype Acute Stroke Registry collected data from 16 hospitals of various sizes and types in Oregon. The goal of this study was to identify whether particular process or structural characteristics of stroke programs in these hospitals were related to the use of reports from the prototype registry to improve care. Researchers surveyed hospitals to ask whether ongoing data completeness reports and monthly comparative quality reports were used to make changes in the acute care process. These self-reports were then confirmed by using the registry data to construct objective run-chart measures over 12 months. Results showed several programmatic characteristics that distinguished programs that used quality reports to make improvements. Hospitals that ignored monthly reports of key performance indicators showed either zero or one positive trend across seven preselected quality indicators. This finding is in contrast to the range of one to four positive changes in quality indicators for report users. Three main characteristics seem to define report users who could translate ongoing findings into potential care improvements: (1) documentation of care processes across departments; (2) access to local or remote stroke teams; and (3) data-collection experiences such as clinical trials, National Institutes of Health Stroke Scale (NIHSS), and outcome feedback. This study could lead to a better understanding as to which characteristics of stroke programs are most important for making rapid improvements for stroke care.
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Servicio de Urgencia en Hospital/normas , Auditoría Médica , Evaluación de Procesos y Resultados en Atención de Salud , Indicadores de Calidad de la Atención de Salud , Sistema de Registros , Accidente Cerebrovascular/tratamiento farmacológico , Enfermedad Aguda , Benchmarking , Humanos , Oregon , Desarrollo de Programa , Evaluación de Programas y Proyectos de Salud , Accidente Cerebrovascular/prevención & control , Encuestas y Cuestionarios , Factores de Tiempo , Estados UnidosRESUMEN
PURPOSE: Little is known about the effects of the electronic health record (EHR) on physician-patient encounters. The objectives of this study were to identify the factors that influence the manner by which physicians use the EHR with patients. METHODS: This ethnographic study included 4 qualitative components: 80 hours of participant observation in 4 primary care offices in the Pacific Northwest; individual interviews with 52 patients, 12 office staff members, 23 physicians, and 1 nurse-practitioner; videotaped reviews of 29 clinical encounters; and 5 focus-group interviews with physicians and computer advocates. The main outcome measures were factors that influence how physicians use the EHR. Researchers qualitatively derived these factors through serial reviews of data. RESULTS: This study identified 14 factors that influence how EHRs are used and perceived in medical practice today. These factors were categorized into 4 thematic domains: (1) spatial--effect of the physical presence and location of EHRs on interactions between physicians and patients; (2) relational--perceptions of physicians and patients about the EHR and how those perceptions affected its use; (3) educational--issues of developing physicians' proficiency with and improving patients' understandings about EHR use; and (4) structural--institutional and technological forces that influence how physicians perceived their use of EHR. CONCLUSIONS: This study found that the introduction of EHRs into practice influences multiple cognitive and social dimensions of the clinical encounter. It brings into focus important questions that through further inquiry can determine how to make best use of the EHR to enhance therapeutic relationships.
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Sistemas de Registros Médicos Computarizados , Relaciones Médico-Paciente , Pautas de la Práctica en Medicina/estadística & datos numéricos , Adulto , Antropología Cultural , Femenino , Encuestas de Atención de la Salud , Humanos , Masculino , Persona de Mediana Edad , Noroeste de Estados UnidosRESUMEN
BACKGROUND AND OBJECTIVES: The use of computers in medical examination rooms is growing. Advocates of this technology suggest that all family physicians should have and use examination room computers (ERCs) within the near future. This study explored how family physicians incorporate the use of ERCs in their interactions with patients. METHODS: This qualitative study involved five family physicians, one family nurse practitioner, and a convenience sample of 29 patients. Data included videotaped visits, clinician interviews, and videotape reviews. The setting was an urban family practice with a 7-year history of viewing electronic medical records. The main outcome measures were themes emergent from videotaped data. RESULTS: We identified three distinct practice styles that shaped the use of the ERC: informational, interpersonal, and managerial styles. Clinicians with an informational style are guided by their attention to gathering data as prompted by the computer screen. Clinicians with an interpersonal style focus their attention and body language on patients. Clinicians with a managerial style bridge informational and interpersonal styles by alternating their attention in defined intervals between patients and the computer. CONCLUSIONS: Family physicians have varying practice styles that affect the way they use examination room computers during visits with patients.
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Computadores/estadística & datos numéricos , Examen Físico/métodos , Médicos de Familia , Pautas de la Práctica en Medicina , Grabación de Cinta de Video , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Comunicación , Femenino , Humanos , Masculino , Aplicaciones de la Informática Médica , Persona de Mediana Edad , Enfermeras Practicantes , Relaciones Profesional-PacienteRESUMEN
Early stages of B cell development are dependent on the expression of a pre-B cell receptor (BCR), composed of a mu heavy chain (HC) in association with surrogate light chain (SLC) proteins and the signaling molecules, Igalpha and Igbeta. During the formation of the variable region of the mu chain by somatic gene rearrangement, a truncated form of the mu protein (called Dmu) is sometimes produced by the rearrangement of a D(H) segment to a J(H) segment using one of three reading frames (designated rf2). When a Dmu protein is formed, subsequent B cell development is blocked by down-regulation of further HC rearrangements, so that a full-length muHC cannot be formed. In this study, we demonstrate that in recombinase activating gene (RAG)-2-deficient B220(+) CD43(+) pro-B cells in which B lymphopoiesis has been arrested at fraction C, transgenic expression of Dmu promoted partial developmental progression to fraction C', but was unable to mediate the pro-B to pre-B cell transition to fraction D effected by full-length muHC protein. These data suggest that the intracellular signaling pathways engaged by the Dmu pre-BCR are insufficient to facilitate the expansion and/or survival of pre-B cells, and are distinct from those engaged by the pre-BCR-containing full-length muHC.
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Linfocitos B/inmunología , Proteínas de Unión al ADN/inmunología , Cadenas mu de Inmunoglobulina/inmunología , Glicoproteínas de Membrana/inmunología , Animales , Linfocitos B/citología , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Proteínas de Unión al ADN/genética , Cadenas Ligeras de Inmunoglobulina/genética , Cadenas Ligeras de Inmunoglobulina/inmunología , Cadenas mu de Inmunoglobulina/genética , Glicoproteínas de Membrana/genética , Ratones , Ratones Transgénicos , Receptores de Células Precursoras de Linfocitos B , Receptores de Antígenos de Linfocitos B , Transducción de Señal/genética , Transducción de Señal/inmunologíaRESUMEN
We describe the genetic and neurological features of toppler, a spontaneous autosomal mutation that appeared in a colony of FVB/N mice and that manifests as severe ataxia appearing at around 12 days of age, worsening with age. The lifespan of affected mice is 8-12 months, with occasional mice living longer. Both homozygous males and females are fertile, and females are able to nurture litters. Histological examination of brain revealed no striking abnormalities other than the loss of cerebellar Purkinje cells. The toppler mutation was mapped to mouse chromosome 8, and to assess whether it was novel or a recurrence of a previously described chromosome 8 mouse mutant, toppler mice were crossed with the nervous and tottering mouse mutants. These studies demonstrate that toppler is a unique mouse mutation. Purkinje cell abnormalities in toppler mice were obvious around postnatal day (P) 14, i.e., toppler Purkinje cells already exhibited abnormal morphology. Staining for calbindin, a calcium binding protein enriched in Purkinje cells, showed altered dendritic morphology. Between P14 and P30, dramatic Purkinje cell loss occurred, although there were differences in the degree of Purkinje cell loss in each lobule. At P30, the surviving Purkinje cells expressed zebrin II. From P30 through 6 months, many of the remaining Purkinje cells gradually degenerated. Purkinje cell loss was analyzed by terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling (TUNEL), and Purkinje cells were TUNEL-positive most abundantly at P21. In addition, Bergmann glia were TUNEL positive at P21, and they expressed activated caspase-3 at earlier time points. Interestingly, despite the apparent death of some Bergmann glia, there was up-regulation of glial fibrillary acidic protein, expressed in astrocytes as well as Bergmann glia. Given the changes in both Purkinje cells and glia in toppler cerebellum, this may be a very useful model in which to investigate the developmental interaction of Purkinje cells and Bergmann glia.
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Ataxia/genética , Ataxia/patología , Cerebelo/patología , Ratones Mutantes Neurológicos , Células de Purkinje/patología , Animales , Animales Recién Nacidos/crecimiento & desarrollo , Animales Recién Nacidos/metabolismo , Ataxia/metabolismo , Ataxia/fisiopatología , Muerte Celular , Sistema Nervioso Central/patología , Cerebelo/fisiopatología , Mapeo Cromosómico , Cruzamientos Genéticos , Femenino , Fructosa-Bifosfato Aldolasa/metabolismo , Expresión Génica , Inmunohistoquímica , Masculino , Ratones , Mutación , Proteínas del Tejido Nervioso/metabolismo , Neuroglía/patología , Fenotipo , Células de Purkinje/metabolismo , Retina/patología , Degeneraciones Espinocerebelosas/genéticaRESUMEN
Bacterial contamination of platelet concentrates (PCs) poses the highest transfusion-associated infectious risk, with Staphylococcus epidermidis being a predominant contaminant. Herein, the growth dynamics of 20 S. epidermidis strains in PCs and regular media were characterized. Strains were categorized as fast (short lag phase) or slow (long lag phase) growers in PCs. All strains were evaluated for the presence of the biofilm-associated icaAD genes by PCR, their capability to produce extracellular polysaccharide (slime) on Congo red agar plates and their ability to form surface-attached aggregates (biofilms) in glucose-supplemented trypticase soy broth (TSBg) using a crystal violet staining assay. A subset of four strains (two slow growers and two fast growers) was further examined for the ability for biofilm formation in PCs. Two of these strains carried the icAD genes, formed slime and produced biofilms in TSBg and PCs, while the other two strains, which did not carry icaAD, did not produce slime or form biofilms in TSBg. Although the two ica-negative slime-negative strains did not form biofilms in media, they displayed a biofilm-positive phenotype in PCs. Although all four strains formed biofilms in PCs, the two slow growers formed significantly more biofilms than the fast growers. Furthermore, growth experiments of the two ica-positive strains in plasma-conditioned platelet bags containing TSBg revealed that a slow grower isolate was more likely to escape culture-based screening than a fast grower strain. Therefore, this study provides novel evidence that links S. epidermidis biofilm formation with slow growth in PCs and suggests that slow-growing biofilm-positive S. epidermidis would be more likely to be missed with automate culture.
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Biopelículas/crecimiento & desarrollo , Plaquetas/microbiología , Staphylococcus epidermidis/aislamiento & purificación , Staphylococcus epidermidis/fisiología , Medios de Cultivo , Humanos , Polisacáridos Bacterianos/metabolismoRESUMEN
Bacterial contamination of platelet concentrates (PCs) poses the greatest infectious risk in modern transfusion medicine despite the implementation of measures such as improved skin disinfection and first aliquot diversion. The majority of PC contaminants are commensal skin flora introduced by venipuncture at the time of blood collection. The predominant organisms are Gram-positive coagulase-negative staphylococci such as Staphylococcus capitis. This bacterium has been implicated in numerous instances of infection and sepsis, likely for its ability to form surface-associated communities of micro-organisms encased in extracellular materials, known as biofilms. In the present study, five strains of S. capitis isolated from contaminated PCs were assessed for their ability to produce extracellular polysaccharide (slime), a canonical indicator of biofilm-formation ability, on Congo red agar plates. Biofilm formation was evaluated in both glucose-enriched trypticase soy broth (TSBg) and in PCs by using a crystal violet staining assay. The chemical nature of the biofilms was evaluated by disruption assays using sodium metaperiodate and proteinase K. In addition, biofilm architecture was observed by scanning electron microscopy. The presence of the biofilm-associated icaR and icaADBC genes was also examined by PCR. While only two out of the five S. capitis strains formed biofilms in TSBg, all strains formed biofilms in PCs. The ability of strains to produce extracellular polysaccharide and their possession of wild-type ica genes were not exclusive predictors of biofilm formation in TSBg or PCs; different profiles of biofilm markers were observed among isolates. This is likely due to the proteinaceous composition of the S. capitis biofilm matrix. Interestingly, an ica-negative, non-slime-producing isolate was capable of biofilm formation in PCs. Together, these data indicate that the platelet storage environment stimulates biofilm formation in S. capitis in the absence of extracellular polysaccharide production and that multiple bacterial factors and regulatory elements are likely involved in biofilm formation in this milieu.
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Biopelículas/crecimiento & desarrollo , Plaquetas/microbiología , Staphylococcus/fisiología , HumanosRESUMEN
Knowledge of the patient's perspective on medical error is limited. Research efforts have centered on how best to disclose error and how patients desire to have medical error disclosed. On the basis of a qualitative descriptive component of a mixed method study, a purposive sample of 30 community members told their stories of medical error. Their experiences focused on lack of communication, missed communication, or provider's poor interpersonal style of communication, greatly contrasting with the formal definition of error as failure to follow a set standard of care. For these participants, being a patient was more important than error or how an error is disclosed. The patient's understanding of error must be a key aspect of any quality improvement strategy.
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Errores Médicos , Satisfacción del Paciente , Adulto , Anciano , Comunicación , Femenino , Humanos , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
The hepatitis delta virus (HDV) is the smallest known RNA pathogen capable of propagation in the human host and causes substantial global morbidity and mortality. Due to its small size and limited protein coding capacity, HDV is exquisitely reliant upon host cellular proteins to facilitate its transcription and replication. Remarkably, HDV does not encode an RNA-dependent RNA polymerase which is traditionally required to catalyze RNA-templated RNA synthesis. Furthermore, HDV lacks enzymes responsible for post-transcriptional and -translational modification, processes which are integral to the HDV life cycle. This review summarizes the known HDV-interacting proteins and discusses their significance in HDV biology.