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1.
Nature ; 574(7776): 63-68, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31554967

RESUMEN

The gp130 receptor cytokines IL-6 and CNTF improve metabolic homeostasis but have limited therapeutic use for the treatment of type 2 diabetes. Accordingly, we engineered the gp130 ligand IC7Fc, in which one gp130-binding site is removed from IL-6 and replaced with the LIF-receptor-binding site from CNTF, fused with the Fc domain of immunoglobulin G, creating a cytokine with CNTF-like, but IL-6-receptor-dependent, signalling. Here we show that IC7Fc improves glucose tolerance and hyperglycaemia and prevents weight gain and liver steatosis in mice. In addition, IC7Fc either increases, or prevents the loss of, skeletal muscle mass by activation of the transcriptional regulator YAP1. In human-cell-based assays, and in non-human primates, IC7Fc treatment results in no signs of inflammation or immunogenicity. Thus, IC7Fc is a realistic next-generation biological agent for the treatment of type 2 diabetes and muscle atrophy, disorders that are currently pandemic.


Asunto(s)
Receptor gp130 de Citocinas/metabolismo , Citocinas/síntesis química , Citocinas/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Inmunoglobulina G/uso terapéutico , Proteínas Recombinantes de Fusión/uso terapéutico , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Unión Competitiva , Citocinas/química , Diabetes Mellitus Tipo 2/metabolismo , Diseño de Fármacos , Hígado Graso/prevención & control , Prueba de Tolerancia a la Glucosa , Humanos , Hiperglucemia/tratamiento farmacológico , Hiperglucemia/metabolismo , Incretinas/metabolismo , Interleucina-6/antagonistas & inhibidores , Interleucina-6/metabolismo , Masculino , Ratones , Músculo Esquelético/efectos de los fármacos , Obesidad/metabolismo , Páncreas/metabolismo , Fosfoproteínas/metabolismo , Ingeniería de Proteínas , Receptores de Interleucina-6/metabolismo , Transducción de Señal , Factores de Transcripción , Aumento de Peso/efectos de los fármacos , Proteínas Señalizadoras YAP
2.
Med Care ; 62(3): 189-195, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38180051

RESUMEN

BACKGROUND: Studies of nurse staffing frequently use data aggregated at the hospital level that do not provide the appropriate context to inform unit-level decisions, such as nurse staffing. OBJECTIVES: Describe a method to link patient data collected during the provision of routine care and recorded in the electronic health record (EHR) to the nursing units where care occurred in a national dataset. RESEARCH DESIGN: We identified all Veterans Health Administration acute care hospitalizations in the calendar year 2019 nationwide. We linked patient-level EHR and bar code medication administration data to nursing units using a crosswalk. We divided hospitalizations into segments based on the patient's time-stamped location (ward stays). We calculated the number of ward stays and medication administrations linked to a nursing unit and the unit-level and facility-level mean patient risk scores. RESULTS: We extracted data on 1117 nursing units, 3782 EHR patient locations associated with 1,137,391 ward stays, and 67,772 bar code medication administration locations associated with 147,686,996 medication administrations across 125 Veterans Health Administration facilities. We linked 89.46% of ward stays and 93.10% of medication administrations to a nursing unit. The average (standard deviation) unit-level patient severity across all facilities is 4.71 (1.52), versus 4.53 (0.88) at the facility level. CONCLUSIONS: Identification of units is indispensable for using EHR data to understand unit-level phenomena in nursing research and can provide the context-specific information needed by managers making frontline decisions about staffing.


Asunto(s)
Investigación en Enfermería , Personal de Enfermería en Hospital , Humanos , Admisión y Programación de Personal , Registros Electrónicos de Salud , Hospitales
3.
Diabetes Obes Metab ; 26(5): 1731-1745, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38351663

RESUMEN

AIM: Acyl-coenzyme A dehydrogenase family member 10 (ACAD10) is a mitochondrial protein purported to be involved in the fatty acid oxidation pathway. Metformin is the most prescribed therapy for type 2 diabetes; however, its precise mechanisms of action(s) are still being uncovered. Upregulation of ACAD10 is a requirement for metformin's ability to inhibit growth in cancer cells and extend lifespan in Caenorhabditis elegans. However, it is unknown whether ACAD10 plays a role in metformin's metabolic actions. MATERIALS AND METHODS: We assessed the role for ACAD10 on whole-body metabolism and metformin action by generating ACAD10KO mice on a C57BL/6J background via CRISPR-Cas9 technology. In-depth metabolic phenotyping was conducted in both sexes on a normal chow and high fat-high sucrose diet. RESULTS: Compared with wildtype mice, we detected no difference in body composition, energy expenditure or glucose tolerance in male or female ACAD10KO mice, on a chow diet or high-fat, high-sucrose diet (p ≥ .05). Hepatic mitochondrial function and insulin signalling was not different between genotypes under basal or insulin-stimulated conditions (p ≥ .05). Glucose excursions following acute administration of metformin before a glucose tolerance test were not different between genotypes nor was body composition or energy expenditure altered after 4 weeks of daily metformin treatment (p ≥ .05). Despite the lack of a metabolic phenotype, liver lipidomic analysis suggests ACAD10 depletion influences the abundance of specific ceramide species containing very long chain fatty acids, while metformin treatment altered clusters of cholesterol ester, plasmalogen, phosphatidylcholine and ceramide species. CONCLUSIONS: Loss of ACAD10 does not alter whole-body metabolism or impact the acute or chronic metabolic actions of metformin in this model.


Asunto(s)
Diabetes Mellitus Tipo 2 , Metformina , Masculino , Femenino , Ratones , Animales , Diabetes Mellitus Tipo 2/metabolismo , Ratones Endogámicos C57BL , Metformina/farmacología , Glucosa/metabolismo , Insulina , Ceramidas , Sacarosa , Dieta Alta en Grasa/efectos adversos
4.
Artif Organs ; 2024 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-39377154

RESUMEN

BACKGROUND: No clear guidelines exist for perioperative anticoagulation management after durable left ventricular assist device insertion. In this study, we sought to compare outcomes between anti-factor Xa (FXa) and activated partial thromboplastin time (aPTT) in monitoring unfractionated heparin (UFH) dosing after HeartMate 3 (HM3) insertion. METHODS: This is a single-center retrospective review of patients who received UFH after HM3 insertion between 01/2020-12/2022. Post-operative UFH dose was titrated by aPTT goal 45-60 sec (n = 53) or FXa goal 0.1-0.2 U/mL (n = 59). Baseline differences between cohorts were balanced by inverse probability treatment weighting. RESULTS: At baseline, unadjusted FXa patients were more likely to be white (47.5% vs. 35.8%, p < 0.001), INTERMACS 1-2 (69.5% vs. 47.2%, p = 0.013), have history of coronary artery disease (66.1% vs. 43.4%, p = 0.026), and lower eGFR (54.1 vs. 63.7 mL/min/1.73 m2, p = 0.029) compared to the aPTT group. After adjusting for several bleeding/thrombosis risk factors, 97.5% of FXa and 91.0% of aPTT patients reached therapeutic levels with comparable UFH duration and maximum dose. Moreover, in-hospital mortality (2.5% vs. 3.1%, p = 0.842), major bleeding events (4.2% vs. 9.2%, p = 0.360), and thromboembolic events (21.8% vs. 10.1%, p = 0.151) remained without significant differences between FXa and aPTT cohorts. There was a high degree of variability in FXa (r2 = 0.20) and aPTT (r2 = 0.22) values for any given UFH dose. CONCLUSIONS: No differences in frequency of bleeding or thromboembolic events were observed in this study between FXa versus aPTT cohorts after HM3 implantation. More longitudinal studies are warranted to determine whether or not one assay is superior to the other.

5.
Comput Inform Nurs ; 41(9): 679-686, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-36648170

RESUMEN

Healthcare systems and nursing leaders aim to make evidence-based nurse staffing decisions. Understanding how nurses use and perceive available data to support safe staffing can strengthen learning healthcare systems and support evidence-based practice, particularly given emerging data availability and specific nursing challenges in data usability. However, current literature offers sparse insight into the nature of data use and challenges in the inpatient nurse staffing management context. We aimed to investigate how nurse leaders experience using data to guide their inpatient staffing management decisions in the Veterans Health Administration, the largest integrated healthcare system in the United States. We conducted semistructured interviews with 27 Veterans Health Administration nurse leaders across five management levels, using a constant comparative approach for analysis. Participants primarily reported using data for quality improvement, organizational learning, and organizational monitoring and support. Challenges included data fragmentation, unavailability and unsuitability to user need, lack of knowledge about available data, and untimely reporting. Our findings suggest that prioritizing end-user experience and needs is necessary to better govern evidence-based data tools for improving nursing care. Continuous nurse leader involvement in data governance is integral to ensuring high-quality data for end-user nurses to guide their decisions impacting patient care.


Asunto(s)
Atención a la Salud , Salud de los Veteranos , Humanos , Estados Unidos , Recursos Humanos
6.
J Aging Phys Act ; 30(2): 297-307, 2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-34453024

RESUMEN

Individuals with mild cognitive impairment are at risk of cognitive and physical decline. Virtual reality (VR) exercise may provide beneficial physical and cognitive exercise. The objectives of this study were to assess the feasibility and safety of home-based VR exercise and to provide pilot data for physical and cognitive efficacy. Eleven individuals with mild cognitive impairment (seven males/four females, average 78 years old, and average 3 years since diagnosis) performed a 30-min home-based VR exercise program 5 days a week for 6 weeks. The VR platform was successfully installed in participants' homes, and all participants were able to learn the VR program and progress. Participants completed 99% of the prescribed exercise. There were no major adverse events. Most participants enjoyed the VR program and reported physical benefits; fewer reported cognitive benefits. No physical or cognitive outcome measures showed change after 6 weeks. Home-based VR exercise is safe and feasible in individuals with mild cognitive impairment.


Asunto(s)
Disfunción Cognitiva , Realidad Virtual , Anciano , Cognición , Disfunción Cognitiva/terapia , Ejercicio Físico , Estudios de Factibilidad , Femenino , Humanos , Masculino
7.
Med Care ; 59(9): 816-823, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-33999572

RESUMEN

BACKGROUND: Hospital performance comparisons for transparency initiatives may be inadequate if peer comparison groups are poorly defined. OBJECTIVE: The objective of this study was to evaluate a new approach identifying hospital peers for comparison. DESIGN/SETTING: We used Mahalanobis distance as a new method of developing peer-specific groupings for hospitals to incorporate both external and internal complexity. We compared the overlap in groups with an existing method used by the Veterans' Health Administration's Office for Productivity, Efficiency, and Staffing (OPES). PARTICIPANTS: One hundred twenty-two acute-care Veterans' Health Administration's Medical Facilities as defined in the OPES fiscal year 2014 report. MEASURES: Using 15 variables in 9 categories developed from expert input, including both hospital internal measures and community-based external measures, we used principal components analysis and calculated Mahalanobis distance between each hospital pair. This method accounts for correlation between variables and allows for variables having different variances. We identified the 50 closest hospitals, then eliminated any potential peer whose score on the first component was >1 SD from the reference hospital. We compared overlap with OPES measures. RESULTS: Of 15 variables, 12 have SDs exceeding 25% of their means. The first 2 components of our analysis explain 24.8% and 18.5% of variation among hospitals. Eight of 9 variables scaling positively on the first component measure internal complexity, aligning with OPES groups. Four of 5 variables scaling positively on the second component but not the first are factors from the policy environment; this component reflects a dimension not considered in OPES groups. CONCLUSION: Individualized peers that incorporate external complexity generate more nuanced comparators to evaluate quality.


Asunto(s)
Atención a la Salud , Hospitales/clasificación , Calidad de la Atención de Salud , Hospitales/normas , Humanos , Proyectos de Investigación , Estados Unidos , United States Department of Veterans Affairs
8.
Clin Sci (Lond) ; 135(2): 367-385, 2021 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-33409538

RESUMEN

Diabetes increases the risk for ischemic vascular diseases, which is further elevated in older adults. Bone marrow-derived hematopoietic CD34+ stem/progenitor cells have the potential of revascularization; however, diabetes attenuates vasoreparative functions. Angiotensin-converting enzyme 2 (ACE2) is the vasoprotective enzyme of renin-angiotensin system in contrast with the canonical angiotensin-converting enzyme (ACE). The present study tested the hypothesis that diabetic dysfunction is associated with ACE2/ACE imbalance in hematopoietic stem/progenitor cells (HSPCs) and that increasing ACE2 expression would restore reparative functions. Blood samples from male and female diabetic (n=71) or nondiabetic (n=62) individuals were obtained and CD34+ cells were enumerated by flow cytometry. ACE and ACE2 enzyme activities were determined in cell lysates. Lentiviral (LV) approach was used to increase the expression of soluble ACE2 protein. Cells from diabetic older adults (DB) or nondiabetic individuals (Control) were evaluated for their ability to stimulate revascularization in a mouse model of hindlimb ischemia (HLI). DB cells attenuated the recovery of blood flow to ischemic areas in nondiabetic mice compared with that observed with Control cells. Administration of DB cells modified with LV-ACE2 resulted in complete restoration of blood flow. HLI in diabetic mice resulted in poor recovery with amputations, which was not reversed by either Control or DB cells. LV-ACE2 modification of Control or DB cells resulted in blood flow recovery in diabetic mice. In vitro treatment with Ang-(1-7) modified paracrine profile in diabetic CD34+ cells. The present study suggests that vasoreparative dysfunction in CD34+ cells from diabetic older adults is associated with ACE2/ACE imbalance and that increased ACE2 expression enhances the revascularization potential.


Asunto(s)
Enzima Convertidora de Angiotensina 2/metabolismo , Diabetes Mellitus/fisiopatología , Células Madre Hematopoyéticas/enzimología , Peptidil-Dipeptidasa A/metabolismo , Adulto , Anciano , Enzima Convertidora de Angiotensina 2/genética , Animales , Antígenos CD34 , Femenino , Técnicas de Transferencia de Gen , Humanos , Isquemia , Lentivirus , Extremidad Inferior/irrigación sanguínea , Masculino , Ratones Desnudos , Persona de Mediana Edad , Peptidil-Dipeptidasa A/genética
9.
J Infect Dis ; 220(3): 361-369, 2019 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-30418598

RESUMEN

BACKGROUND: Liver failure of unknown etiology (LFUE) has a transplant-free survival rate <25%. Human herpesvirus 6 (HHV-6) may be associated with LFUE, but studies are limited by small sample size. METHODS: We identified all children who underwent liver transplant for LFUE at a single quaternary children's hospital; 51/65 cases could be age matched with controls (children who underwent liver transplant for metabolic liver disease). Quantitative polymerase chain reaction for HHV-6 was performed on DNA from formalin-fixed paraffin-embedded liver explant tissue. RESULTS: HHV-6 was detected in 34/51 cases (66.7%) and 19/51 controls (37.3%) (P = .005). Average HHV-6 viral load was 213207 copies/106 cells in positive cases (range: 7293-1102030) and 38115 copies/106 cells in positive controls (range: 1382-122375) (P = .0008). HHV-6 was present significantly more often in cases compared to controls in patients younger than 6 years. In particular, in patients younger than 3 years, HHV-6 was present in 13/27 cases (48.1%) and 2/27 controls (7.4%) (P = .0009). CONCLUSIONS: HHV-6 was detected in liver explants significantly more often and in higher quantities in children transplanted for LFUE compared to controls, suggesting HHV-6 should be evaluated in young children who present with LFUE.


Asunto(s)
Herpesvirus Humano 6 , Fallo Hepático/virología , Hígado/virología , Infecciones por Roseolovirus/virología , Trasplantes/virología , Adolescente , Niño , Preescolar , Estudios de Cohortes , Femenino , Herpesvirus Humano 6/genética , Herpesvirus Humano 6/aislamiento & purificación , Humanos , Lactante , Hígado/patología , Fallo Hepático/etiología , Fallo Hepático/patología , Fallo Hepático/cirugía , Trasplante de Hígado , Masculino , Infecciones por Roseolovirus/complicaciones , Infecciones por Roseolovirus/patología
10.
Am J Med Genet C Semin Med Genet ; 181(1): 28-35, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30779428

RESUMEN

X-chromosome inactivation generally results in dosage equivalence for expression of X-linked genes between 46,XY males and 46,XX females. The 20-30% of genes that escape silencing are thus candidates for having a role in the phenotype of Turner syndrome. Understanding which genes escape from silencing, and how they avoid this chromosome-wide inactivation is therefore an important step toward understanding Turner Syndrome. We have examined the mechanism of escape using a previously reported knock-in of a BAC containing the human escape gene RPS4X in mouse. We now demonstrate that escape from inactivation for RPS4X is already established by embryonic Day 9.5, and that both silencing and escape are faithfully maintained across the lifespan. No overt abnormalities were observed for transgenic mice up to 1 year of age despite robust transcription of the human RPS4X gene with no detectable downregulation of the mouse homolog. However, there was no significant increase in protein levels, suggesting translational compensation in the mouse. Finally, while many of the protein-coding genes have been assessed for their inactivation status, less is known about the X-linked RNA genes, and we propose that for many microRNA genes their inactivation status can be predicted as they are intronic to genes for which the inactivation status is known.


Asunto(s)
Proteínas Ribosómicas/genética , Síndrome de Turner/genética , Inactivación del Cromosoma X , Animales , Femenino , Genes Ligados a X , Genes de ARNr , Humanos , Ratones
11.
Semin Cell Dev Biol ; 56: 71-77, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-26849907

RESUMEN

The process of X-chromosome inactivation (XCI) randomly silences one of two X chromosomes in normal female cells. The ability to predict if there is a preference for one of the two Xs to be chosen (and survive) more often as the active X has important repercussions in human health and X-linked disease. Mice have a genetic component that modulates non-random skewing called the X-controlling element (Xce). Although the nature of the locus and its mechanisms of action are still under investigation, it is clear that different mouse strains carry unique Xce alleles on their X chromosomes, resulting in distinct skewing phenotypes in the F1 progeny of hybrid crosses. Whether a similar mechanism exists in humans is unclear, and challenges to identifying such a locus include the complexity and diversity of the human genome, the restricted time points and tissue(s) of examination in human subjects, and the lack of a model system recapitulating XCI in early development. In this review we consider the evidence for such a controlling locus in humans, in addition to discussing if we have the power to recognize it given the contribution of selective growth in causing skewed patterns of XCI.


Asunto(s)
Cromosoma X/genética , Animales , Sitios Genéticos , Humanos , Modelos Biológicos , Inactivación del Cromosoma X/genética
12.
Dermatol Ther ; 31(6): e12656, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30264512

RESUMEN

Lichen planopilaris (LPP) is an inflammatory cicatricial alopecia for which many different therapies are attempted with varying success. The Janus kinase (JAK) inhibitor, tofacitinib, has been shown to be effective in treating the noncicatricial alopecia, alopecia areata. As in alopecia areata, upregulation of interferon and JAK signaling may play a role in LPP. We retrospectively reviewed the cases of 10 patients with recalcitrant LPP who were treated with oral tofacitinib. Patients received oral tofacitinib 5 mg twice or three times daily for 2-19 months as either monotherapy or adjunctive therapy to other ongoing treatments including intralesional triamcinolone, hydroxychloroquine, and tacrolimus ointment. Eight patients had clinical improvement in LPP with tofacitinib as either monotherapy (4/10) or adjunctive therapy (4/10). LPP Activity Index (LPPAI) before and after treatment was measured in seven patients and was significantly different (6.22 before treatment, 3.08 after treatment; p value = .0014). Reduction in LPPAI ranged from 30 to 94%. One patient complained of 10 pound (4.5 kg) weight gain after 12 months on tofacitinib. No other adverse effects were reported. Treatment with oral tofacitinib either as monotherapy or adjunctive therapy can lead to measurable improvement in recalcitrant LPP.


Asunto(s)
Alopecia/tratamiento farmacológico , Fármacos Dermatológicos/administración & dosificación , Inhibidores de las Cinasas Janus/administración & dosificación , Liquen Plano/tratamiento farmacológico , Piperidinas/administración & dosificación , Pirimidinas/administración & dosificación , Pirroles/administración & dosificación , Dermatosis del Cuero Cabelludo/tratamiento farmacológico , Piel/efectos de los fármacos , Administración Oral , Adulto , Anciano , Alopecia/diagnóstico , Alopecia/enzimología , Fármacos Dermatológicos/efectos adversos , Esquema de Medicación , Femenino , Humanos , Inhibidores de las Cinasas Janus/efectos adversos , Liquen Plano/diagnóstico , Liquen Plano/enzimología , Masculino , Persona de Mediana Edad , Piperidinas/efectos adversos , Pirimidinas/efectos adversos , Pirroles/efectos adversos , Inducción de Remisión , Estudios Retrospectivos , Cuero Cabelludo , Dermatosis del Cuero Cabelludo/diagnóstico , Dermatosis del Cuero Cabelludo/enzimología , Piel/enzimología , Piel/patología , Factores de Tiempo , Resultado del Tratamiento
13.
Genes Dev ; 24(1): 21-32, 2010 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-20008927

RESUMEN

MacroH2A1 is a histone variant that is enriched on the inactive X chromosome (Xi) in mammals and is postulated to play an important, but unknown, role in the repression of gene expression. Here we show that, although macroH2A1 marks repressed autosomal chromatin, it positively regulates transcription when located in the transcribed regions of a subset of its target genes. We used chromatin immunoprecipitation (ChIP) coupled with tiling microarrays (ChIP-chip) to determine the genomic localization of macroH2A1 in IMR90 human primary lung fibroblasts and MCF-7 breast cancer cells. The patterns of macroH2A1 deposition are largely similar across the autosomes of both cell lines. Our studies revealed a genomic localization pattern unique among histone variants; namely, the occupation by macroH2A1 of large chromatin domains (>500 kb in some cases) that contain repressive chromatin marks (e.g., histone H3 Lys 27 trimethylation). The boundaries of macroH2A1-containing domains tend to occur in promoter-proximal regions. Not all promoters, however, serve as macroH2A1 boundaries; many macroH2A1-containing chromatin domains invade the transcribed regions of genes whose products play key roles in development and cell-cell signaling. Surprisingly, the expression of a subset of these genes is positively regulated by macroH2A1. MacroH2A1 also plays a role in augmenting signal-regulated transcription, specifically for genes responsive to serum starvation. Collectively, our results document an unexpected role for macroH2A1 in the escape from heterochromatin-associated silencing and the enhancement of autosomal gene transcription.


Asunto(s)
Cromatina/genética , Silenciador del Gen , Histonas/genética , Histonas/metabolismo , Línea Celular Tumoral , Inmunoprecipitación de Cromatina , Regulación de la Expresión Génica , Crecimiento y Desarrollo/genética , Humanos , Metilación , Análisis de Secuencia por Matrices de Oligonucleótidos , Transducción de Señal/genética , Sitio de Iniciación de la Transcripción
14.
Anal Biochem ; 518: 9-15, 2017 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-27815077

RESUMEN

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has created an urgent need for new therapeutic agents capable of combating this threat. We have previously reported on the discovery of novel inhibitors targeting enzymes involved in the biosynthesis of wall teichoic acid (WTA) and demonstrated that these agents can restore ß-lactam efficacy against MRSA. In those previous reports pathway engagement of inhibitors was demonstrated by reduction in WTA levels measured by polyacrylamide gel electrophoresis. To enable a more rigorous analysis of these inhibitors we sought to develop a quantitative method for measuring whole-cell reductions in WTA. Herein we describe a robust methodology for hydrolyzing polymeric WTA to the monomeric component ribitol-N-acetylglucosamine coupled with measurement by LC-MS/MS. Critical elements of the protocol were found to include the time and temperature of hydrofluoric acid-mediated hydrolysis of polymeric WTA and optimization of these parameters is fully described. Most significantly, the assay enabled accurate and reproducible measurement of depletion EC50s for tunicamycin and representatives from the novel class of TarO inhibitors, the tarocins. The method described can readily be adapted to quantifying levels of WTA in tissue homogenates from a murine model of infection, highlighting the applicability for both in vitro and in vivo characterizations.


Asunto(s)
Espectrometría de Masas/métodos , Staphylococcus aureus Resistente a Meticilina/metabolismo , Ácidos Teicoicos/metabolismo , Cromatografía Liquida/métodos , Staphylococcus aureus Resistente a Meticilina/química , Ácidos Teicoicos/química , Tunicamicina/farmacología
15.
Am J Physiol Endocrinol Metab ; 310(10): E838-45, 2016 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-27006199

RESUMEN

Nitric oxide influences intramuscular signaling that affects skeletal muscle glucose uptake during exercise. The role of the main NO-producing enzyme isoform activated during skeletal muscle contraction, neuronal nitric oxide synthase-µ (nNOSµ), in modulating glucose uptake has not been investigated in a physiological exercise model. In this study, conscious and unrestrained chronically catheterized nNOSµ(+/+) and nNOSµ(-/-) mice either remained at rest or ran on a treadmill at 17 m/min for 30 min. Both groups of mice demonstrated similar exercise capacity during a maximal exercise test to exhaustion (17.7 ± 0.6 vs. 15.9 ± 0.9 min for nNOSµ(+/+) and nNOSµ(-/-), respectively, P > 0.05). Resting and exercise blood glucose levels were comparable between the genotypes. Very low levels of NOS activity were detected in skeletal muscle from nNOSµ(-/-) mice, and exercise increased NOS activity only in nNOSµ(+/+) mice (4.4 ± 0.3 to 5.2 ± 0.4 pmol·mg(-1)·min(-1), P < 0.05). Exercise significantly increased glucose uptake in gastrocnemius muscle (5- to 7-fold) and, surprisingly, more so in nNOSµ(-/-) than in nNOSµ(+/+) mice (P < 0.05). This is in parallel with a greater increase in AMPK phosphorylation during exercise in nNOSµ(-/-) mice. In conclusion, nNOSµ is not essential for skeletal muscle glucose uptake during exercise, and the higher skeletal muscle glucose uptake during exercise in nNOSµ(-/-) mice may be due to compensatory increases in AMPK activation.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Glucemia/metabolismo , Músculo Esquelético/metabolismo , Óxido Nítrico Sintasa de Tipo I/genética , Condicionamiento Físico Animal , Animales , Femenino , Glucosa/metabolismo , Masculino , Ratones , Ratones Noqueados , Fosforilación
16.
Bioorg Med Chem Lett ; 26(19): 4743-4747, 2016 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-27575474

RESUMEN

A series of benzimidazole analogs have been synthesized to improve the profile of the previous lead compounds tarocin B and 1. The syntheses, structure-activity relationships, and selected biochemical data of these analogs are described. The optimization efforts allowed the identification of 21, a fluoro-substituted benzimidazole, exhibiting potent TarO inhibitory activity and typical profile for a wall teichoic acid (WTA) biosynthesis inhibitor. Compound 21 displayed a potent synergistic and bactericidal effect in combination with imipenem against diverse methicillin-resistant Staphylococci.


Asunto(s)
Antibacterianos/farmacología , Bencimidazoles/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Ácidos Teicoicos/antagonistas & inhibidores , Animales , Antibacterianos/química , Bencimidazoles/química , Pruebas de Sensibilidad Microbiana , Ratas , Relación Estructura-Actividad , Ácidos Teicoicos/biosíntesis
17.
Bioorg Med Chem Lett ; 26(16): 3999-4002, 2016 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-27436582

RESUMEN

The widespread emergence of methicillin-resistant Staphylococcus aureus (MRSA) has dramatically eroded the efficacy of current ß-lactam antibiotics and created an urgent need for novel treatment options. Using an S. aureus phenotypic screening strategy, we have identified small molecule early stage wall teichoic acid (WTA) pathway-specific inhibitors predicted to be chemically synergistic with ß-lactams. These previously disclosed inhibitors, termed tarocins, demonstrate by genetic and biochemical means inhibition of TarO, the first step in WTA biosynthesis. Tarocins demonstrate potent bactericidal synergy in combination with broad spectrum ß-lactam antibiotics across diverse clinical isolates of methicillin-resistant Staphylococci. The synthesis and structure-activity relationships (SAR) of a tarocin series will be detailed. Tarocins and other WTA inhibitors may provide a rational strategy to develop Gram-positive bactericidal ß-lactam combination agents active against methicillin-resistant Staphylococci.


Asunto(s)
Antibacterianos/química , Ácidos Teicoicos/metabolismo , beta-Lactamas/antagonistas & inhibidores , Antibacterianos/síntesis química , Antibacterianos/farmacología , Pared Celular/efectos de los fármacos , Pared Celular/metabolismo , Evaluación Preclínica de Medicamentos , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Staphylococcus aureus/efectos de los fármacos , Relación Estructura-Actividad , beta-Lactamas/metabolismo
18.
Pediatr Transplant ; 20(3): 456-9, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26917412

RESUMEN

An eight-yr-old female with a history of multifocal lymphangioendotheliomatosis and thrombocytopenia presented for MVT. The patient had multiple vascular lesions in the skin and stomach in infancy. Although her cutaneous lesions resolved with vincristine and methylprednisolone, her gastric lesions persisted. Eight yr later, she was diagnosed with portal hypertension and decompensating liver function despite therapy with bevacizumab, propranolol, furosemide, and spironolactone. Upon presentation, she was found to have a Kasabach-Merritt-like coagulopathy in association with multiple lesions in her GI tract and persistent gastric lesions. Although treatment with methylprednisolone and sirolimus normalized her coagulation factors and d-dimer levels, she never developed sustained improvement in her thrombocytopenia. Her liver function continued to deteriorate and she developed hepatorenal syndrome. Given better outcomes after OLT in comparison with MVT, she underwent OLT, with the plan to manage her GI lesions with APC post-transplant. Post-transplant, her liver function and coagulopathy normalized, and GI tract lesions disappeared upon screening with capsule endoscopy. The patient is doing well, without recurrence of either GI lesions or thrombocytopenia, at 18 months after transplantation.


Asunto(s)
Trasplante de Hígado/métodos , Linfangioma/complicaciones , Linfangioma/cirugía , Trombocitopenia/complicaciones , Trombocitopenia/cirugía , Coagulación Sanguínea , Factores de Coagulación Sanguínea , Niño , Colestasis , Femenino , Productos de Degradación de Fibrina-Fibrinógeno/química , Tracto Gastrointestinal/patología , Síndrome Hepatorrenal/complicaciones , Humanos , Hipertensión Portal , Metilprednisolona/administración & dosificación , Estómago/patología , Resultado del Tratamiento , Vincristina/administración & dosificación
19.
Gynecol Oncol ; 138(3): 647-55, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26186909

RESUMEN

OBJECTIVE: Resistance to platinum-based therapeutic agents represents a major hurdle in the treatment of epithelial ovarian cancer (EOC). There is an urgent need to better understand the underlying mechanisms. Here, we investigated the role of RUNX3 in carboplatin resistance in EOC cells. METHODS: Expression of RUNX3 was determined in human EOC cell line A2780s (cisplatin-sensitive) and A2780cp (cisplatin-resistant), human ovarian surface epithelium (OSE) and primary EOC cells. The effects of RUNX3 expression on sensitivity to carboplatin were determined in A2780s and A2780cp cells using neutral red uptake and clonogenic assays. Carboplatin-induced apoptosis was determined by measuring cleaved PARP using Western blotting. The expression of cellular inhibitor of apoptosis protein-2 (cIAP2) and its regulation by RUNX3 were assessed by quantitative RT-PCR and Western blotting. RESULTS: The expression of RUNX3 was elevated in A2780cp cells compared to A2780s cells and in EOC tissues from chemoresistant patients compared to those from chemosensitive patients. Overexpression of RUNX3 rendered A2780s cells more resistant to carboplatin, whereas inhibition of RUNX3 increased sensitivity to carboplatin in A2780cp cells. Inhibition of RUNX3 potentiated carboplatin-induced apoptosis in A2780cp cells as demonstrated by more pronounced PARP cleavage. Interestingly, the expression of cIAP2 was elevated in A2780cp cells compared to A2780s cells. Overexpression of RUNX3 increased cIAP2 expression in A2780s cells, whereas inhibition of RUNX3 decreased cIAP2 expression and potentiated carboplatin-induced decrease of cIAP2 in A2780cp cells. CONCLUSIONS: RUNX3 contributes to carboplatin resistance in EOC cells and may hold promise as a therapeutic target to treat EOC and/or a biomarker to predict chemoresistance.


Asunto(s)
Antineoplásicos/farmacología , Carboplatino/farmacología , Subunidad alfa 3 del Factor de Unión al Sitio Principal/biosíntesis , Neoplasias Glandulares y Epiteliales/tratamiento farmacológico , Neoplasias Glandulares y Epiteliales/metabolismo , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/metabolismo , Proteína 3 que Contiene Repeticiones IAP de Baculovirus , Carcinoma Epitelial de Ovario , Línea Celular Tumoral , Subunidad alfa 3 del Factor de Unión al Sitio Principal/genética , Resistencia a Antineoplásicos , Técnicas de Silenciamiento del Gen , Humanos , Proteínas Inhibidoras de la Apoptosis/biosíntesis , Proteínas Inhibidoras de la Apoptosis/genética , Neoplasias Glandulares y Epiteliales/genética , Neoplasias Ováricas/genética , Ubiquitina-Proteína Ligasas/biosíntesis , Ubiquitina-Proteína Ligasas/genética
20.
J Pediatr Gastroenterol Nutr ; 60(3): 308-11, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25714574

RESUMEN

OBJECTIVES: The North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition has formulated guidelines for managing functional constipation. There have been no studies that have investigated how pediatricians apply the constipation guideline since it was revised in 2006. The purpose of this study was to examine how pediatricians approach functional constipation and how closely their approaches adhere to the guidelines. METHODS: An anonymous multiple-choice questionnaire was developed by general pediatricians and pediatric gastroenterologists. This was distributed to pediatricians and pediatric residents at 7 academic institutions, and to the American Academy of Pediatrics section on medical students, residents, and fellowship trainees mailing list. RESULTS: A total of 1202 responses were received (952 trainees, 250 attendings). Of these, 84.3% reported being unfamiliar/slightly familiar with the guidelines. The most common initial interventions for constipation without fecal incontinence included fluids (92.1%), fiber (89.5%), juice (77.7%), behavioral interventions (71.2%), follow-up (53.4%), and reducing constipating foods (50.1%). The most common initial interventions for constipation with fecal incontinence included bowel cleanout (73.4%), maintenance medication (70.0%), fluids (67.9%), behavioral interventions (67.6%), fiber (66.1%), and follow-up (57.8%). Osmotics were the most commonly prescribed as needed (83.0%) and maintenance medications (96.8%), with stimulants prescribed PRN by 35.6% and as maintenance by 16.8%. Some individuals (39.7%) reported concern that osmotics could result in dependence, addiction, or electrolyte imbalances, compared with 73.0% for stimulants. CONCLUSIONS: Our results show that more education regarding medication in functional constipation is necessary, including the use of medication reducing time to remission, the necessity of disimpaction, and misconceptions regarding adverse effects.


Asunto(s)
Estreñimiento/terapia , Adhesión a Directriz , Conocimientos, Actitudes y Práctica en Salud , Intestinos/fisiopatología , Guías de Práctica Clínica como Asunto , Pautas de la Práctica en Medicina , Centros Médicos Académicos , California , Niño , Terapia Combinada/efectos adversos , Estreñimiento/fisiopatología , Becas , Gastroenterología/educación , Encuestas de Atención de la Salud , Humanos , Agencias Internacionales , Internet , Internado y Residencia , América del Norte , Pediatría/educación , Sociedades Médicas , Estudiantes de Medicina , Estados Unidos , Recursos Humanos
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