RESUMEN
Pericardial effusion or the accumulation of fluid in the pericardial sac, can result from infectious, malignant, or autoimmune processes such as systemic lupus erythematous (SLE). However, pericardial effusion is infrequently the first presentation of SLE. Here, we describe the case of a 54-year-old African American woman who presented with hypertensive emergency and was found to have pericardial effusion on echocardiogram. Her hypertensive symptoms resolved with medical management and a work up were positive for serum markers of SLE and mesothelioma cell markers (calretinin, CK 5/6) and adenocarcinoma marker MOC31 in the pericardial fluid. Her effusion ultimately improved on high-dose steroid therapy and has not recurred in one year. Given normal pleura and pericardium on computed tomography (CT) imaging and long-term clinical improvement in SLE therapy, we hypothesize that she had false-positive mesothelioma markers in the setting of SLE.
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Intracerebroventricular (ICV) injection of streptozotocin (STZ) is a well established procedure to induce neuroinflammation leading to dementia in experimental animals. However, the optimal dose of STZ has not been determined. In the present study, rats were ICV injected with 1.5, 3 and 6 mg of STZ per kg of body weight. After 21 days, neuroinflammatory markers i.e. TNF-α, IL-1ß, ROS and nitrite were quantified in the hippocampus. Memory function was assessed by the radial arm maze test after 9, 12, 15, 18, 21 days following STZ injection. STZ treatment significantly increased neuroinflammatory markers and decreased memory functions in a dose dependent manner showing optimum effects at the dose of 3 mg/kg.
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Mediadores de Inflamación/metabolismo , Trastornos de la Memoria/inducido químicamente , Trastornos de la Memoria/metabolismo , Estreptozocina/administración & dosificación , Estreptozocina/toxicidad , Animales , Relación Dosis-Respuesta a Droga , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Inyecciones Intraventriculares , Masculino , Ratas , Especies Reactivas de Oxígeno/metabolismoRESUMEN
BACKGROUND: Studies have shown that higher body mass index (BMI) is associated with improved prognosis in heart failure (HF), and this is often termed the obesity paradox. HYPOTHESIS: Analysis of body composition may reveal that muscle mass rather than adipose tissue accounts for the obesity paradox. METHODS: Bioelectrical impedance analysis of body composition in 359 outpatients with HF was performed using an In Body 520 body composition scale (Biospace Inc., California). Body fat and lean mass were indexed by height (m2 ). The cohort was stratified by median fat and lean mass indexed by height. RESULTS: The mean age of patients studied was 56 ± 14; mean left ventricular ejection fraction was 38 ± 16%. Patients with higher indexed body fat mass had improved 5-year survival over patients with lower indexed body fat mass (90.2% vs 80.1%, P = 0.008). There was also improved survival in patients with high vs low indexed lean body mass (89.3% vs 80.9%, P = 0.036). On multivariable analysis, higher indexed body fat mass, but not lean body mass, was independently associated with improved survival (HR 0.89, per kg/m2 increase in indexed body fat mass, P = 0.044); however, this was attenuated after adjustment for diabetes. The combination of low lean with low-fat mass was independently associated with poor prognosis. CONCLUSIONS: Our data suggest that higher fat mass-and to a lesser extent higher lean mass-is associated with improved outcomes in HF. Further investigations of specific components of body composition and outcomes in HF are warranted.
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Insuficiencia Cardíaca/fisiopatología , Obesidad/epidemiología , Volumen Sistólico/fisiología , Composición Corporal , Comorbilidad , Impedancia Eléctrica , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Obesidad/fisiopatología , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia/tendencias , Factores de Tiempo , Estados Unidos/epidemiologíaRESUMEN
An important marker in Alzheimer disease (AD) is the abnormal production and accumulation of ß-amyloid peptide (Aß) in brain. It produces oxidative damage in neurons and inflammation due to its neurotoxic properties. The present study was designed to investigate neuroinflammation (hippocampal levels of ROS, nitrite, TNF-α, and IL-1ß), neurodegeneration (plaques and chromatolysis in hippocampus), and memory impairments (working memory and reference memory) and the effect of this neuroinflammation on some peripheral immunological parameters such as phagocytic activity of blood WBC and splenic polymorphonuclear (PMN) cells, leucocyte adhesion inhibition index (LAI), and cytotoxicity of splenic mononuclear cells (MNC) after the intracebroventricular injection of aggregated Aß(1-42)in a 4week study. The results showed that the hippocampal and serum levels of ROS, nitrite, TNF-α, and IL-1ß were significantly higher in the AD animals along with increased chromatolysis and impairments of memory. There was also a significant increase in the phagocytic activity of splenic PMN and cytotoxicity of splenic MNC and a decrease in the phagocytic activity of blood WBC and LAI of splenic MNC in the Aß(1-42)-injected AD rats compared to that of control and sham-operated rats. The results indicate that the increased levels of inflammatory markers in the hippocampus may provide signals to the periphery and can alter the systemic immune responses.
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Enfermedad de Alzheimer/inmunología , Hipocampo/inmunología , Inmunidad Innata , Fagocitosis , Bazo/inmunología , Enfermedad de Alzheimer/etiología , Enfermedad de Alzheimer/fisiopatología , Péptidos beta-Amiloides/administración & dosificación , Péptidos beta-Amiloides/toxicidad , Animales , Citocinas/metabolismo , Hipocampo/fisiopatología , Inflamación , Inyecciones Intraventriculares , Masculino , Memoria a Corto Plazo , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/toxicidad , Ratas , Especies Reactivas de Oxígeno/metabolismo , Bazo/citologíaRESUMEN
We describe a simple bioinformatics method for biomarker discovery that is based on the analysis of global transcript levels in a population of inbred mouse strains showing variation for disease-related traits. This method has advantages such as controlled environment and accessibility to heart and plasma tissue in the preclinical selection stage. We illustrate the approach by identifying candidate heart failure (HF) biomarkers by overlaying mouse transcriptome and clinical traits from 91 Hybrid Mouse Diversity Panel (HMDP) inbred strains and human HF transcriptome from the Myocardial Applied Genomics Network (MAGNet) consortium. We found that some of the top differentially expressed genes correlated with known human HF biomarkers, such as galectin-3 and tissue inhibitor of metalloproteinase 1. Using ELISA assays, we investigated one novel candidate, Glycoprotein NMB, in a mouse model of chronic ß-adrenergic stimulation by isoproterenol (ISO) induced HF. We observed significantly lower GPNMB plasma levels in the ISO model compared to the control group (p-value = 0.007). In addition, we assessed GPNMB plasma levels among 389 HF cases and controls from the METabolic Syndrome In Men (METSIM) study. Lower levels of GPNMB were also observed in patients with HF from the METSIM study compared to non-HF controls (p-value < 0.0001). In summary, we have identified several candidate biomarkers for HF using the cardiac transcriptome data in a population of mice that may be directly relevant and applicable to human populations.
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Proteínas del Ojo/metabolismo , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/metabolismo , Glicoproteínas de Membrana/sangre , Glicoproteínas de Membrana/metabolismo , Anciano , Animales , Biomarcadores/metabolismo , Biología Computacional , Modelos Animales de Enfermedad , Femenino , Galectina 3/genética , Humanos , Masculino , Ratones Endogámicos C57BL , Persona de Mediana Edad , Inhibidor Tisular de Metaloproteinasa-1/genética , TranscriptomaRESUMEN
BACKGROUND: Approximately 4% of the African-American population possess a valine-to-isoleucine (V122I) substitution within the transthyretin protein that results in a tendency for a normally tetrameric protein to dissociate into misfolded, monomeric subunits. These misfolded proteins can then accumulate pathologically and cause an autosomal dominant amyloid cardiomyopathy. Homozygous patients are infrequently documented in case reports, and though there are larger studies among heterozygous patients, there is a lack of studies or reports comparing disease within a family. CASE SUMMARY: In this case series, we discuss a 61-year-old African-American male who succumbed to heart failure secondary to cardiac amyloidosis while awaiting orthotopic heart transplantation. We compare his case with that of his sister, a 65-year-old African-American woman with a history of recurrent supraventricular tachycardia requiring radiofrequency ablation, and intermittent chest pain with chronically elevated troponin despite no evidence of coronary artery disease. The sister in question was found to be homozygous for the transthyretin (TTR) V122I mutation with evidence of infiltrative process on cardiac magnetic resonance imaging, while clinical testing verified a heterozygous genotype in the brother. Here, we compare the clinical course and imaging data for the aforementioned brother-sister pair in the context of the amyloidogenic transthyretin V122I gene variant. DISCUSSION: Through this familial report, we aim to highlight the variations in expression both within this family and in comparison, to the population. We also hope to emphasize the importance of genetic testing of families at risk for this specific transthyretin variant within the African-American community especially as novel therapies begin to emerge.
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Although mouse models exist for many immune-based diseases, the clinical translation remains challenging. Most basic and translational studies utilize only a single inbred mouse strain. However, basal and diseased immune states in humans show vast inter-individual variability. Here, focusing on macrophage responses to lipopolysaccharide (LPS), we use the hybrid mouse diversity panel (HMDP) of 83 inbred strains as a surrogate for human natural immune variation. Since conventional bioinformatics fail to analyse a population spectrum, we highlight how gene signatures for LPS responsiveness can be derived based on an Interleukin-12ß and arginase expression ratio. Compared to published signatures, these gene markers are more robust to identify susceptibility or resilience to several macrophage-related disorders in humans, including survival prediction across many tumours. This study highlights natural activation diversity as a disease-relevant dimension in macrophage biology, and suggests the HMDP as a viable tool to increase translatability of mouse data to clinical settings.
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Variación Genética , Activación de Macrófagos/genética , Modelos Animales , Animales , Predisposición Genética a la Enfermedad , Humanos , Inmunidad Innata/genética , Inflamación , Lipopolisacáridos , Masculino , Ratones , Neoplasias/inmunología , Neoplasias/mortalidad , FenotipoRESUMEN
Intracerebroventricular (i.c.v.) injection of colchicine induces neurodegeneration, memory impairments and changes of some systemic immune responses in rats. Though the role of cox 2 in these colchicine induced changes have been evaluated, the influence of nitric oxide synthase (NOS) remains to be studied. The present study was designed to assess the role of NOS on the i.c.v. colchicine induced neurodegeneration, memory impairments and changes of some systemic immune responses by inhibiting its activity with aminoguanidine. In the present study the impairments of working and reference memories, neurodegeneration (chromatolysis and plaque formation) and changes of neuroinflammatory markers in the hippocampus (increased TNF α, IL 1ß, ROS and nitrite) along with changes of serum inflammatory markers (TNF α, IL 1ß, ROS and nitrite) and alteration of systemic immune responses (higher phagocytic activity of blood WBC and splenic PMN, higher cytotoxicity and lower leukocyte adhesion inhibition index of splenic MNC) were measured in the intracerebroventricular colchicine injected rats (ICIR). Administration of aminoguanidine (p.o. 30/50mg/kg body weight) to ICIR resulted in recovery of neuroinflammation and partial prevention of neurodegeneration which could be corroborated with the partial recovery of memory impairments in this model. The recovery of serum inflammatory markers and the systemic immune responses in ICIR was also observed after administration of aminoguanidine. Therefore, the present study shows that aminoguanidine can protect the colchicine induced neurodegeneration, memory impairments, and changes of systemic immune systemic responses in ICIR by inhibiting the iNOS.
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Colchicina/toxicidad , Inhibidores Enzimáticos/uso terapéutico , Guanidinas/uso terapéutico , Trastornos de la Memoria/tratamiento farmacológico , Enfermedades Neurodegenerativas/tratamiento farmacológico , Óxido Nítrico Sintasa de Tipo II/antagonistas & inhibidores , Animales , Colchicina/administración & dosificación , Inhibidores Enzimáticos/farmacología , Guanidinas/farmacología , Hipocampo/efectos de los fármacos , Hipocampo/inmunología , Inyecciones Intraventriculares , Masculino , Trastornos de la Memoria/inducido químicamente , Trastornos de la Memoria/inmunología , Ratones , Enfermedades Neurodegenerativas/inducido químicamente , Enfermedades Neurodegenerativas/inmunología , Óxido Nítrico Sintasa de Tipo II/inmunología , RatasRESUMEN
The neurodegeneration in colchicine induced AD rats (cAD) is mediated by cox-2 linked neuroinflammation. The importance of ROS in the inflammatory process in cAD has not been identified, which may be deciphered by blocking oxidative stress in this model by a well-known anti-oxidant vitamin C. Therefore, the present study was designed to investigate the role of vitamin C on colchicine induced oxidative stress linked neuroinflammation mediated neurodegeneration and memory impairments along with peripheral immune responses in cAD. The impairments of working and reference memory were associated with neuroinflammation and neurodegeneration in the hippocampus of cAD. Administration of vitamin C (200 and 400 mg/kg BW) in cAD resulted in recovery of memory impairments, with prevention of neurodegeneration and neuroinflammation in the hippocampus. The neuroinflammation in the hippocampus also influenced the peripheral immune responses and inflammation in the serum of cAD and all of these parameters were also recovered at 200 and 400 mg dose of vitamin C. However, cAD treated with 600 mg dose did not recover but resulted in increase of memory impairments, neurodegeneration and neuroinflammation in hippocampus along with alteration of peripheral immune responses in comparison to cAD of the present study. Therefore, the present study showed that ROS played an important role in the colchicine induced neuroinflammation linked neurodegeneration and memory impairments along with alteration of peripheral immune responses. It also appears from the results that vitamin C at lower doses showed anti-oxidant effect and at higher dose resulted in pro-oxidant effects in cAD.
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Enfermedad de Alzheimer/tratamiento farmacológico , Antiinflamatorios/uso terapéutico , Ácido Ascórbico/uso terapéutico , Memoria/efectos de los fármacos , Vitaminas/uso terapéutico , Enfermedad de Alzheimer/etiología , Animales , Antiinflamatorios/administración & dosificación , Antiinflamatorios/farmacología , Ácido Ascórbico/administración & dosificación , Ácido Ascórbico/farmacología , Colchicina/toxicidad , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Inflamación/tratamiento farmacológico , Masculino , Ratones , Estrés Oxidativo , Ratas , Especies Reactivas de Oxígeno/metabolismo , Vitaminas/administración & dosificación , Vitaminas/farmacologíaRESUMEN
BACKGROUND: Complete documentation of patient comorbidities in the medical record is important for clinical care, hospital reimbursement, and quality performance measures. We designed a pocket card reminder and brief educational intervention aimed at hospitalists with the goal of improving documentation of 6 common comorbidities present on admission: coagulation abnormalities, metastatic cancer, anemia, fluid and electrolyte abnormalities, malnutrition, and obesity. METHODS: Two internal medicine inpatient teams led by 10 hospitalist physicians at an academic medical center received the educational intervention and pocket card reminder (n = 520 admissions). Two internal medicine teams led by nonhospitalist physicians served as a control group (n = 590 admissions). Levels of documentation of 6 common comorbidities, expected length of stay, and expected mortality were measured at baseline and during the 9-month study period. RESULTS: The intervention was associated with increased documentation of anemia, fluid and electrolyte abnormalities, malnutrition, and obesity in the intervention group, both compared to baseline and compared to the control group during the study period. The expected length of stay increased in the intervention group during the study period. CONCLUSIONS: A simple educational intervention and pocket card reminder were associated with improved documentation and hospital quality measures at an academic medical center.
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Comorbilidad , Documentación/métodos , Médicos Hospitalarios/educación , Mejoramiento de la Calidad , Sistemas Recordatorios/estadística & datos numéricos , Centros Médicos Académicos/organización & administración , Adulto , Femenino , Encuestas de Atención de la Salud , Mortalidad Hospitalaria , Humanos , Medicina Interna/educación , Medicina Interna/métodos , Masculino , Persona de Mediana Edad , Calidad de la Atención de Salud , Encuestas y CuestionariosRESUMEN
Obesity has reached epidemic proportions in the general population and is associated with an increased risk for the development of new-onset heart failure (HF). However, in acute and chronic HF, overweight and mild to moderate obesity is associated with substantially improved survival compared with normal weight. This phenomenon has been termed the "obesity paradox" in HF. The majority of data pertaining to the obesity paradox identifies obesity with body mass index; however, the reliability of this method has been questioned. Newer studies have explored the use of other measures of body fat and body composition, including waist circumference, waist-to-hip ratio, skinfold thickness, and bioelectrical impedance analysis of body composition. The relationship between the obesity paradox and cardiorespiratory fitness in HF is also discussed in this review, and we explore the various potential explanations for the obesity paradox and summarize the current evidence and guidelines for intentional weight loss treatments for HF in the obese population.
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Insuficiencia Cardíaca/etiología , Obesidad/complicaciones , Índice de Masa Corporal , Progresión de la Enfermedad , Salud Global , Insuficiencia Cardíaca/epidemiología , Humanos , Incidencia , Obesidad/epidemiología , Pronóstico , Factores de Riesgo , Tasa de Supervivencia/tendencias , Pérdida de PesoRESUMEN
Generating cardiomyocytes from embryonic stem cells is an important technique for understanding cardiovascular development, the origins of cardiovascular diseases and also for providing potential reagents for cardiac repair. Numerous methods have been published but often are technically challenging, complex, and are not easily adapted to assessment of specific gene contributions to cardiac myocyte differentiation. Here we report the development of an optimized protocol to induce the differentiation of mouse embryonic stem cells to cardiac myocytes that is simplified and easily adapted for genetic studies. Specifically, we made four critical findings that distinguish our protocol: 1) mouse embryonic stem cells cultured in media containing CHIR99021 and PD0325901 to maintain pluripotency will efficiently form embryoid bodies containing precardiac mesoderm when cultured in these factors at a reduced dosage, 2) low serum conditions promote cardiomyocyte differentiation and can be used in place of commercially prepared StemPro nutrient supplement, 3) the Wnt inhibitor Dkk-1 is dispensable for efficient cardiac differentiation and 4) tracking differentiation efficiency may be done with surface expression of PDGFRα alone. In addition, cardiac mesodermal precursors generated by this system can undergo lentiviral infection to manipulate the expression of specific target molecules to assess effects on cardiac myocyte differentiation and maturation. Using this approach, we assessed the effects of CHF1/Hey2 on cardiac myocyte differentiation, using both gain and loss of function. Overexpression of CHF1/Hey2 at the cardiac mesoderm stage had no apparent effect on cardiac differentiation, while knockdown of CHF1/Hey2 resulted in increased expression of atrial natriuretic factor and connexin 43, suggesting an alteration in the phenotype of the cardiomyocytes. In summary we have generated a detailed and simplified protocol for generating cardiomyocytes from mES cells that is optimized for investigating factors that affect cardiac differentiation.
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Técnicas de Cultivo de Célula/métodos , Diferenciación Celular , Células Madre Embrionarias/citología , Miocitos Cardíacos/citología , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/deficiencia , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Proteína Morfogenética Ósea 4/metabolismo , Supervivencia Celular , Cuerpos Embrioides/citología , Células Madre Embrionarias/metabolismo , Regulación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Células HEK293 , Proteína Homeótica Nkx-2.5 , Proteínas de Homeodominio/metabolismo , Humanos , Lentivirus/fisiología , Mesodermo/citología , Mesodermo/virología , Ratones , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Proteínas Represoras/deficiencia , Proteínas Represoras/genética , Suero/metabolismo , Factores de Transcripción/metabolismoRESUMEN
OBJECTIVES: In this study, we examined the predictive value of the left ventricular end-diastolic pressure (LVEDP) in patients undergoing balloon aortic valvuloplasty (BAV). BACKGROUND: The LVEDP is a useful indicator of hemodynamic status in patients with severe aortic stenosis. In BAV, decompensated heart failure is associated with worse outcomes. METHODS: We identified all consecutive patients with severe symptomatic aortic stenosis who underwent retrograde BAV at the Massachusetts General Hospital from 2004 to 2008. Patients were stratified and compared according to their baseline LVEDP into ≤15 mm Hg, 16-20 mm Hg, 21-25 mm Hg, and ≥26 mm Hg. Procedural and in-hospital outcomes and adverse events were compared. Multivariate logistic regression was used for the adjusted analysis. RESULTS: A total of 111 patients with a mean age of 83±11 years underwent BAV. Of these, the LVEDP was ≤15 mm Hg in 29 (26%), 16-20 mm Hg in 41 (37%), 21-25 mm Hg in 16 (14%), and ≥26 mm Hg in 25 (23%) patients. Baseline characteristics were similar among the four groups. Noticeably, patients with high LVEDP levels had significantly higher rates of the combined endpoint of in-hospital death, myocardial infarction (MI), cardiopulmonary arrest, and tamponade was P = 0.02. Periprocedural MI was more common among those with higher LVEDP (16% vs. 2.3%; P = 0.04). Multivariate analysis revealed LVEDP (OR 1.08, for each mm Hg increase in pressure, 95 % CI 1.02-1.14), small LV chamber size, and New York Heart Association class as independent predictors of adverse outcomes. CONCLUSIONS: The LVEDP is an important independent predictor of poor in-hospital outcome during BAV. In these patients, the immediate hemodynamic status may be more important than the baseline left ventricular systolic function. Hemodynamic optimization before or during BAV should be considered and may be beneficial.
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Estenosis de la Válvula Aórtica/terapia , Valvuloplastia con Balón , Función Ventricular Izquierda , Presión Ventricular , Anciano , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/diagnóstico , Estenosis de la Válvula Aórtica/mortalidad , Estenosis de la Válvula Aórtica/fisiopatología , Valvuloplastia con Balón/efectos adversos , Valvuloplastia con Balón/mortalidad , Boston , Taponamiento Cardíaco/etiología , Taponamiento Cardíaco/fisiopatología , Distribución de Chi-Cuadrado , Femenino , Paro Cardíaco/etiología , Paro Cardíaco/fisiopatología , Mortalidad Hospitalaria , Hospitales Generales , Humanos , Modelos Logísticos , Masculino , Análisis Multivariante , Infarto del Miocardio/etiología , Infarto del Miocardio/fisiopatología , Oportunidad Relativa , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo , Resultado del TratamientoRESUMEN
OBJECTIVES: To evaluate the impact of left ventricular (LV) chamber size on procedural and hospital outcomes of patients undergoing aortic valvuloplasty. BACKGROUND: Balloon aortic valvuloplasty (BAV) is used as an integral step during transcatheter aortic valve implantation. Patients with small, thickened ventricles are thought to have more complications during and following BAV. METHODS: Retrospective study of consecutive patients with severe, symptomatic calcific aortic stenosis who underwent retrograde BAV at Massachusetts General Hospital. We compared patients with left ventricular end-diastolic diameters (LVEDD) <4.0 cm (n = 31) to those with LVEDD ≥4.0 cm (n = 78). Baseline and procedural characteristics as well as clinical outcomes were compared. Multivariate logistic regression was used for the adjusted analysis. RESULTS: Patients with smaller LV chamber size were mostly women (80.7% vs. 19.4%, P < 0.01) and had a smaller body surface area (BSA), (1.61 ± 0.20 m(2) vs. 1.79 ± 0.25 m(2) , P < 0.01). Patients with smaller LV chamber size had higher ejection fractions and thicker ventricles. Otherwise, baseline characteristics were similar. The intraprocedural composite of death, cardiopulmonary arrest, intubation, hemodynamic collapse, and tamponade was higher for patients with LVEDD < 4.0 cm (32.3% v. 11.5%, P = 0.01). Adjusting for age, gender, BSA, LV pressure, and New York Heart Association class, LVEDD < 4.0 cm remained an independent predictor of procedural (OR 5.1, 95% CI 1.4-18.2) and in-hospital complications (OR 3.8, 95% CI 1.2-11.6). CONCLUSIONS: Compared to patients undergoing BAV with LVEDD ≥4.0 cm, those with smaller LV chambers had worse procedural and in-hospital outcomes.
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Estenosis de la Válvula Aórtica/terapia , Valvuloplastia con Balón/efectos adversos , Calcinosis/terapia , Ventrículos Cardíacos , Hipertrofia Ventricular Izquierda/etiología , Anciano , Anciano de 80 o más Años , Válvula Aórtica/patología , Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/diagnóstico , Estenosis de la Válvula Aórtica/fisiopatología , Superficie Corporal , Boston , Calcinosis/complicaciones , Calcinosis/diagnóstico , Calcinosis/fisiopatología , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Hospitales Generales , Humanos , Hipertrofia Ventricular Izquierda/diagnóstico , Hipertrofia Ventricular Izquierda/fisiopatología , Modelos Lineales , Modelos Logísticos , Masculino , Análisis Multivariante , Oportunidad Relativa , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Índice de Severidad de la Enfermedad , Volumen Sistólico , Resultado del Tratamiento , Ultrasonografía , Función Ventricular IzquierdaRESUMEN
Connexin43 (Cx43), a component of gap junctions, has a relatively large carboxy-terminal region with multiple proteomic interactions. Proteomic interactions with its cytoplasmic loop, however, are poorly defined. The goal of this study is to examine proteomic interactions involving the cytoplasmic loop (CL) of Cx43. The authors utilized various techniques, including glutathione-S-transferase (GST) pull-down, immunoblot analysis, two-dimensional (2D) gel electrophoresis, and mass spectrometry, to elucidate binding partners for Cx43-CL. The authors identified novel interactions with Cx43-CL involving α- and ß-tubulin, myelin basic protein, and Purα. Because tubulin interacts with the C-terminus of Cx43 (Cx43-CT), the authors further investigated the nature of the interaction between ß-tubulin and Cx43-CL. ß-Tubulin binds with the full length of Cx43-CL with approximately one-fifth the affinity of the interaction between Cx43-CT and ß-tubulin. This study demonstrates novel proteomic interactions involving Cx43-CL that may lead to a more complete understanding of trafficking and gating of gap junction channels.
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Conexina 43/metabolismo , Proteínas de Unión al ADN/análisis , Proteína Básica de Mielina/análisis , Proteínas del Tejido Nervioso/análisis , Proteómica/métodos , Tubulina (Proteína)/análisis , Animales , Citoplasma/metabolismo , Proteínas de Unión al ADN/metabolismo , Electroforesis en Gel Bidimensional , Uniones Comunicantes/metabolismo , Glutatión Transferasa/antagonistas & inhibidores , Immunoblotting , Canales Iónicos/metabolismo , Espectrometría de Masas , Ratones , Proteína Básica de Mielina/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Unión Proteica , Tubulina (Proteína)/metabolismoRESUMEN
BACKGROUND: Cardiac insults such as ischemia, infarction, hypertrophy and dilatation are often accompanied by altered abundance and/or localization of the connexin43 gap junction protein, which may predispose towards arrhythmic complications. Models of chronic dyssynchronous cardiac activation have also been shown to result in redistribution of connexin43 in cardiomyocytes. We hypothesized that alterations in connexin43 expression and localization in the mouse heart might be induced by ventricular pacing over a short period of time. RESULTS: The subdiaphragmatic approach was used to pace a series of wild type mice for six hours before the hearts were removed for analysis. Mice were paced at 10-15% above their average anesthetized sinus rate and monitored to ensure 1:1 capture. Short-term pacing resulted in a significant reduction in connexin43 mRNA abundance, a partial redistribution of connexin43 from the sarcolemma to a non-sarcolemmal fraction, and accumulation of ubiquitinated connexin43 without a significant change in overall connexin43 protein levels. These early pacing-induced changes in connexin43 expression were not accompanied by decreased cardiac function, prolonged refractoriness or increased inducibility into sustained arrhythmias. CONCLUSION: Our data suggest that short-term pacing is associated with incipient changes in the expression of the connexin43 gap junction, possibly including decreased production and a slowed rate of degradation. This murine model may facilitate the study of early molecular changes induced by pacing and may ultimately assist in the development of strategies to prevent gap junction remodeling and the associated arrhythmic complications of cardiac disease.