Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Nutrients ; 15(22)2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-38004241

RESUMEN

BACKGROUND: Many clinical factors can contribute to the efficacy of medical therapy in Inflammatory Bowel Disease (IBD). We assessed their effects on the efficacy of vedolizumab therapy in a cohort of patients with IBD. METHODS: We conducted a retrospective study on patients between 18 and 80 years of age with ulcerative colitis (UC) or Crohn's disease (CD) who were seen in the IBD program at Houston Methodist in Houston, TX and treated with vedolizumab for at least 6 months from 2018 to 2022. We investigated factors prior to the initiation of therapy that best predicted treatment response, with an emphasis on vitamin D levels and examined several variables including patients' demographics and clinical information on disease location and severity and nutritional status before and after the initiation of vedolizumab. Post-treatment data were gathered after a minimum of 6 months of vedolizumab therapy. The clinical parameters used for the study were the Harvey-Bradshaw Index for CD and the Activity Index for UC. RESULTS: There were 88 patients included in our study of whom 44 had CD and 44 had UC.; median age was 39.5 (31.0, 53.25) years; 34% patients were male; and 80.7% were Caucasian. All patients received an induction dosing of 300 mg vedolizumab at 0, 2, and 6 weeks then maintenance dosing as standard of care every 8 weeks. Among UC patients with vitamin D ≥ 30 ng/mL at the initiation of vedolizumab therapy, UC Endoscopic Index of Severity (UCEIS) scores after 6 months of therapy were significantly lower than in those who had low pre-treatment vitamin D levels (1.5 vs. 3.87, p = 0.037). After treatment, vitamin D levels improved more significantly in the higher pre-treatment vitamin D group, with a median level of 56 ng/mL, than in the lower pre-treatment vitamin D group, with a median level of only 31 ng/mL (p = 0.007). In patients with CD with vitamin D ≥ 30 ng/mL at the initiation of vedolizumab therapy, we found higher iron saturation (12 vs. 25%, p = 0.008) and higher vitamin B12 levels (433.5 vs. 885 pg/mL, p = 0.003) than in those with vitamin D < 30 ng/mL. After treatment, CD patients with high pre-treatment vitamin D levels had significantly higher vedolizumab levels (27.35 vs. 14.35 µg/mL, p = 0.045) than those with low pre-treatment vitamin D. Post-treatment scores and inflammatory markers in CD patients (HBI, CRP, ESR, and SES-CD) were lower in those who had lower baseline vitamin D. CONCLUSIONS: Our results show higher pre-treatment vitamin D levels predicted significant endoscopic improvement in patients with ulcerative colitis (UC). Improving vitamin D levels lowered C-reactive protein levels significantly in CD patients. Higher vitamin D levels were seen after treatment in both UC and CD patients. Vitamin D can play a role in clinical and endoscopic outcomes and should be assessed routinely and optimized in patients with IBD.


Asunto(s)
Colitis Ulcerosa , Enfermedad de Crohn , Enfermedades Inflamatorias del Intestino , Humanos , Masculino , Adulto , Lactante , Femenino , Colitis Ulcerosa/tratamiento farmacológico , Colitis Ulcerosa/inducido químicamente , Vitamina D/uso terapéutico , Estudios Retrospectivos , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Enfermedades Inflamatorias del Intestino/inducido químicamente , Enfermedad de Crohn/tratamiento farmacológico , Enfermedad de Crohn/inducido químicamente , Vitaminas/uso terapéutico , Fármacos Gastrointestinales , Resultado del Tratamiento
2.
Clin Exp Gastroenterol ; 16: 21-28, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36915649

RESUMEN

This review addresses appropriate patient selection for upadacitinib, a Janus kinase inhibitor approved by the FDA and EMA for treatment of moderately to severely active ulcerative colitis (UC). Janus kinase molecules can contribute to the inflammatory pathway, so inhibiting certain of them may prove efficacious in treating UC and may reduce safety concerns. Upadacitinib is the newest Janus kinase inhibitor to be approved for UC, so it is timely and relevant to review patient selection and when to consider this medication. We will discuss efficacy and safety data from the pivotal clinical trials on upadacitinib. These data can be shared with patients and can inform the use of these agents in clinical practice.

3.
J Cancer Res Clin Oncol ; 149(2): 877-883, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36102989

RESUMEN

BACKGROUND: Despite the efficacy of immune checkpoint inhibitors (ICIs), adverse events including hepatotoxicity limit their ongoing use. We investigated the outcomes and management of patients with immune-mediated hepatitis (IMH) and clinical predictors of toxicity resolution. METHODS: Patients referred to our multidisciplinary immunotherapy-related toxicity group from August 2017 to December 2020 for IMH were evaluated. Toxicity was defined according to CTCAEv4.0. IMH resolution was defined as liver enzyme normalization after steroid initiation. RESULTS: Thirty-three patients were included in the study, 62% female, and 71% Caucasian. The most common ICI used was PD-1/PD-L1 (76%). Peak IMH occurred at a median of 89 [45,193] days, for which most patients received 1-2 mg/kg/day prednisone equivalent with 35% requiring MMF. Median follow-up was 123 [33,472] days with IMH resolution seen in 48% of patients at a median of 111 [41,214] days. While high-dose steroid use was not associated with IMH resolution, liver enzyme improvement one week after steroids predicted resolution in univariate analysis (p = 0.041). All 11 patients without IMH resolution died from cancer progression or complications with three patients having acute liver failure. Available liver biopsies showed bile duct injury, with varying degrees of portal and lobular inflammation. CONCLUSION: IMH improvement one week after steroid initiation may predict ultimate IMH resolution.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Hepatitis , Neoplasias , Humanos , Femenino , Masculino , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/etiología , Hepatitis/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Inmunoterapia/efectos adversos , Estudios Retrospectivos
4.
Nutrients ; 14(6)2022 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-35334967

RESUMEN

Background: Malnutrition has been linked to adverse health economic outcomes. There is a paucity of data on malnutrition in patients admitted with COVID-19. Methods: This is a retrospective cohort study consisting of 4311 COVID-19 adult (18 years and older) inpatients at 5 Johns Hopkins-affiliated hospitals between 1 March and 3 December 2020. Malnourishment was identified using the malnutrition universal screening tool (MUST), then confirmed by registered dietitians. Statistics were conducted with SAS v9.4 (Cary, NC, USA) software to examine the effect of malnutrition on mortality and hospital length of stay among COVID-19 inpatient encounters, while accounting for possible covariates in regression analysis predicting mortality or the log-transformed length of stay. Results: COVID-19 patients who were older, male, or had lower BMIs had a higher likelihood of mortality. Patients with malnutrition were 76% more likely to have mortality (p < 0.001) and to have a 105% longer hospital length of stay (p < 0.001). Overall, 12.9% (555/4311) of adult COVID-19 patients were diagnosed with malnutrition and were associated with an 87.9% increase in hospital length of stay (p < 0.001). Conclusions: In a cohort of COVID-19 adult inpatients, malnutrition was associated with a higher likelihood of mortality and increased hospital length of stay.


Asunto(s)
COVID-19 , Desnutrición , Adulto , Hospitales , Humanos , Pacientes Internos , Tiempo de Internación , Masculino , Desnutrición/diagnóstico , Estudios Retrospectivos
5.
Dig Dis Sci ; 67(4): 1362-1370, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-33835374

RESUMEN

BACKGROUND: Prior studies have evaluated clinical characteristics associated with opioid dose requirements in hospitalized patients with acute pancreatitis (AP) but did not incorporate morphologic findings on CT imaging. AIMS: We sought to determine whether morphologic severity on imaging is independently associated with opioid dose requirements in AP. METHODS: Adult inpatients with a diagnosis of AP from 2006 to 2017 were reviewed. The highest modified CT severity index (MCTSI) score and the daily oral morphine equivalent (OME) for each patient over the first 7 days of hospitalization were used to grade the morphologic severity of AP and calculate mean OME per day(s) of treatment (MOME), respectively. Multiple regression analysis was used to evaluate the association of MOME with MCSTI. RESULTS: There were 249 patients with AP, of whom 196 underwent contrast-enhanced CT. The mean age was 46 ± 13.6 years, 57.9% were male, and 60% were black. The mean MOME for the patient cohort was 60 ± 52.8 mg/day. MCTSI (ß = 3.5 [95% CI 0.3, 6.7], p = 0.03), early hemoconcentration (ß = 21 [95% CI 4.6, 39], p = 0.01) and first episode of AP (ß = - 17 [95% CI - 32, - 2.7], p = 0.027) were independently associated with MOME. Among the 19 patients undergoing ≥ 2 CT scans, no significant differences in MOME were seen between those whose MCTSI score increased (n = 12) versus decreased/remained the same (n = 7). CONCLUSION: The morphologic severity of AP positively correlated with opioid dose requirements. No difference in opioid dose requirements were seen between those who did versus those who did not experience changes in their morphologic severity.


Asunto(s)
Analgésicos Opioides , Pancreatitis , Enfermedad Aguda , Adulto , Analgésicos Opioides/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Pancreatitis/inducido químicamente , Pancreatitis/diagnóstico por imagen , Pancreatitis/tratamiento farmacológico , Estudios Retrospectivos , Índice de Severidad de la Enfermedad
6.
Scand J Gastroenterol ; 57(1): 91-98, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34663162

RESUMEN

OBJECTIVE: The aim of the present study is to assess the impact of smoking dose and duration on the distribution of risk factor(s) in patients with RAP and CP, and the impact of genetic testing on the distribution of risk factor(s) in patients with idiopathic RAP and CP. METHODS: All adult patients with RAP and CP referred to a multidisciplinary pancreatitis clinic between 2010 and 2017 were evaluated. Risk factors included alcohol and smoking, hypertriglyceridemia, biliary, and other etiologies. Genetic testing was only pursued in patients with idiopathic RAP or CP. RESULTS: Among the 1770 patients evaluated, 167 had RAP and 303 had CP. After genetic testing and smoking, the most common risk factors for RAP and CP were pathogenic variant(s) (23%) and the combination of alcohol and smoking (23%), respectively. Genetic testing and smoking assessment decreased the proportion of patients with alcoholic RAP from 17% to 5%, alcoholic CP from 33% to 10%, idiopathic RAP from 49% to 12%, and idiopathic CP from 54% to 14%. Pathogenic CFTR variants were the most common variant in patients with RAP (51%) and CP (43%). Among the 68 patients with pancreas divisum, other risk factor(s) were identified in 72%. CONCLUSION: Genetic testing and a detailed assessment of smoking dose and duration reduce the proportion of patients with alcoholic and idiopathic pancreatitis. Other risk factor(s) for pancreatitis are found in the majority of patients with pancreas divisum further questioning its role as an independent risk factor.1. What is the current knowledge?Approximately 30% of patients with pancreatitis have no clear risk factor(s) and are categorized as having an idiopathic etiology.Pathogenic variant(s) as well as smoking dose and duration are well-established risk factors for recurrent acute and chronic pancreatitis but are not widely recognized or incorporated into clinical practice.2. What is new here?Genetic testing and a detailed assessment of smoking dose and duration reduced the proportion of patients with alcoholic and idiopathic acute recurrent and chronic pancreatitis.Approximately three-fourths of patients with pancreas divisum have a risk factor for pancreatitis.


Asunto(s)
Pancreatitis Crónica , Enfermedad Aguda , Adulto , Pruebas Genéticas , Humanos , Pancreatitis Crónica/genética , Pancreatitis Crónica/patología , Recurrencia , Factores de Riesgo , Fumar/efectos adversos
8.
Pancreas ; 48(6): 844-849, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31210667

RESUMEN

OBJECTIVES: Deep pancreatic cannulation (DPC) failure during endoscopic retrograde cholangiopancreatography (ERCP) in patients with chronic pancreatitis (CP) can occur in the presence of ductal obstruction due to strictures and/or stones. There are currently no simple preprocedure clinical or laboratory tests that can predict DPC failure during ERCP. METHODS: All adult patients with definite CP by M-ANNHEIM criteria referred to the pancreatitis clinic between 2010 and 2017 were evaluated. Serum trypsin levels were obtained to assess the morphologic severity of disease and/or exocrine insufficiency. Univariable and multivariable logistic regression analyses were performed to identify factors associated with DPC failure. RESULTS: There were 346 patients, of whom 100 underwent trypsin measurements and ERCP for symptomatic CP. Deep pancreatic cannulation failure occurred in 32 (32%). There were no significant differences with regard to age, sex, etiology, smoking, and alcohol use. Deep pancreatic cannulation failure was more likely to occur in patients with low trypsin levels (53.1% vs 25%, P = 0.007) compared with those with successful DPC. Low trypsin levels were independently associated with DPC failure in adjusted analysis (odds ratio, 3.7; 95% confidence interval, 1.2-11; P = 0.02). CONCLUSIONS: Low serum trypsin levels independently predict DPC failure during ERCP in patients with symptomatic obstructive CP.


Asunto(s)
Cateterismo/métodos , Colangiopancreatografia Retrógrada Endoscópica/métodos , Páncreas/diagnóstico por imagen , Conductos Pancreáticos/diagnóstico por imagen , Pancreatitis Crónica/diagnóstico por imagen , Tripsina/sangre , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pancreatitis Crónica/sangre , Pronóstico , Estudios Retrospectivos
9.
Curr Treat Options Gastroenterol ; 17(1): 146-160, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30701454

RESUMEN

PURPOSE OF REVIEW: Despite the increasing incidence of acute pancreatitis, the overall mortality of AP has decreased. RECENT FINDINGS: The findings of recent studies on fluid therapy, analgesics, antibiotics, and enteral nutrition as well as the management of AP complications have led to improvements in clinical care. However, there are still no pharmacologic treatment(s) for AP. Experimental studies have revealed many potential therapeutic targets, but these will need to be further developed and tested before they can be assessed in randomized controlled trials with important clinical endpoints.

10.
J Biomed Mater Res B Appl Biomater ; 104(8): 1713-1720, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-26348258

RESUMEN

BACKGROUND: Previous studies have demonstrated that surgical patches comprised of small intestinal submucosa-derived extracellular matrix (ECM) have biological remodeling potential. This pilot study investigated histological, mechanical, and bioelectrical properties of an ECM patch implanted in the ovine right-ventricular outflow tract (RVOT). MATERIALS AND METHODS: ECM patches (2 × 2 cm2 ) were implanted in four Western Range sheep (wether males, 37-49 kg, age <1 year) and explanted at 5 months (n = 2) and 8 months (n = 2). In vivo analysis included epicardial echocardiography and contact electrical mapping. Optical mapping was used to map electrical activity of two hearts on a Langendorff preparation. Mechanical testing quantified stiffness. Histological stains characterized structure, neovascularization, and calcification; immunohistochemistry (IHC) assessed cell phenotype. RESULTS: In vivo analysis showed that ECM patch tissue was contractile by M-mode and two-dimensional echocardiographic evaluation. In vivo electrical mapping, and optical mapping confirmed that ECM conducted an organized electrical signal. Mechanical testing of native and ECM patched RVOT tissue showed an elastic modulus of the implanted patch comparable to native tissue stiffness. CONCLUSIONS: At 5 and 8 months, the ECM had undergone extracellular matrix remodeling and neovascularization without calcification. The ECM was populated with locally aligned muscle cells positive for sarcomeric alpha-actinin, CD45, and troponin I and T. In sheep, the ECM patch appears to have the potential of remodeling to resemble native, functional ventricular tissue as evidenced by histological, mechanical, and electrical properties. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1713-1720, 2016.


Asunto(s)
Matriz Extracelular/química , Mucosa Intestinal/química , Intestino Delgado/química , Contracción Miocárdica , Miocardio , Animales , Electrocardiografía , Femenino , Proyectos Piloto , Ovinos
11.
Nat Protoc ; 10(8): 1264-74, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26203823

RESUMEN

Subcutaneous xenografts have been used for decades to study hepatocellular carcinoma (HCC). These models do not reproduce the specific pathophysiological features of HCCs, which occur in cirrhotic livers that show pronounced necroinflammation, abnormal angiogenesis and extensive fibrosis. As these features are crucial for studying the role of the pathologic host microenvironment in tumor initiation, progression and treatment response, alternative HCC models are desirable. Here we describe a syngeneic orthotopic HCC model in immunocompetent mice with liver cirrhosis induced by carbon tetrachloride (CCl4) that recapitulates key features of human HCC. Induction of substantial hepatic fibrosis requires 12 weeks of CCl4 administration. Intrahepatic implantation of mouse HCC cell lines requires 30 min per mouse. Tumor growth varies by tumor cell line and mouse strain used. Alternatively, tumors can be induced in a genetically engineered mouse model. In this setting, CCl4 is administered for 12 weeks after tail-vein injection of Cre-expressing adenovirus (adeno-Cre) in Stk4(-/-)Stk3(F/-) (also known as Mst1(-/-)Mst2(F/-); F indicates a floxed allele) mice, and it results in the development of HCC tumors (hepatocarcinogenesis) concomitantly with liver cirrhosis.


Asunto(s)
Carcinoma Hepatocelular , Cirrosis Hepática/inducido químicamente , Neoplasias Hepáticas Experimentales , Neoplasias Hepáticas , Animales , Tetracloruro de Carbono , Ratones Endogámicos C3H , Trasplante Heterólogo
12.
Heart Rhythm ; 12(6): 1352-61, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25748673

RESUMEN

BACKGROUND: Vagal hyperactivity promotes atrial fibrillation (AF), which has been almost exclusively attributed to acetylcholine. Vasoactive intestinal polypeptide (VIP) and acetylcholine are neurotransmitters co-released during vagal stimulation. Exogenous VIP has been shown to promote AF by shortening action potential duration (APD), increasing APD spatial heterogeneity, and causing intra-atrial conduction block. OBJECTIVE: The purpose of this study was to investigate the effects of neuronally released VIP on atrial electrophysiologic properties during vagal stimulation. METHODS: We used a specific VIP antagonist (H9935) to uncover the effects of endogenous VIP released during vagal stimulation in canine hearts. RESULTS: H9935 significantly attenuated (1) the vagally induced shortening of atrial effective refractory period and widening of atrial vulnerability window during stimulation of cervical vagosympathetic trunks (VCNS) and (2) vagal effects on APD during stimulation through fat-pad ganglion plexus (VGPS). Atropine completely abolished these vagal effects during VCNS and VGPS. In contrast, VGPS-induced slowing of local conduction velocity was completely abolished by either VIP antagonist or atropine. In pacing-induced AF during VGPS, maximal dominant frequencies and their spatial gradients were reduced significantly by H9935 and, more pronouncedly, by atropine. Furthermore, VIP release in the atria during vagal stimulation was inhibited by atropine, which may account for the concealment of VIP effects with muscarinic blockade. CONCLUSION: Neuronally released VIP contributes to vagal effects on atrial electrophysiologic properties and affects the pathophysiology of vagally induced AF. Neuronal release of VIP in the atria is inhibited by muscarinic blockade, a novel mechanism by which VIP effects are concealed by atropine during vagal stimulation.


Asunto(s)
Fibrilación Atrial/etiología , Función Atrial/fisiología , Estimulación del Nervio Vago , Péptido Intestinal Vasoactivo/metabolismo , Péptido Intestinal Vasoactivo/fisiología , Potenciales de Acción , Animales , Atropina/farmacología , Perros , Muscarina/farmacología , Periodo Refractario Electrofisiológico/efectos de los fármacos , Péptido Intestinal Vasoactivo/antagonistas & inhibidores
13.
Hepatology ; 61(5): 1591-602, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25529917

RESUMEN

UNLABELLED: Sorafenib, a broad tyrosine kinase inhibitor, is the only approved systemic therapy for advanced hepatocellular carcinoma (HCC) but provides limited survival benefits. Recently, immunotherapy has emerged as a promising treatment strategy, but its role remains unclear in HCCs, which are associated with decreased cytotoxic CD8(+) T-lymphocyte infiltration in both murine and human tumors. Moreover, in mouse models after sorafenib treatment intratumoral hypoxia is increased and may fuel evasive resistance. Using orthotopic HCC models, we now show that increased hypoxia after sorafenib treatment promotes immunosuppression, characterized by increased intratumoral expression of the immune checkpoint inhibitor programmed death ligand-1 and accumulation of T-regulatory cells and M2-type macrophages. We also show that the recruitment of immunosuppressive cells is mediated in part by hypoxia-induced up-regulation of stromal cell-derived 1 alpha. Inhibition of the stromal cell-derived 1 alpha receptor (C-X-C receptor type 4 or CXCR4) using AMD3100 prevented the polarization toward an immunosuppressive microenvironment after sorafenib treatment, inhibited tumor growth, reduced lung metastasis, and improved survival. However, the combination of AMD3100 and sorafenib did not significantly change cytotoxic CD8(+) T-lymphocyte infiltration into HCC tumors and did not modify their activation status. In separate experiments, antibody blockade of the programmed death ligand-1 receptor programmed death receptor-1 (PD-1) showed antitumor effects in treatment-naive tumors in orthotopic (grafted and genetically engineered) models of HCC. However, anti-PD-1 antibody treatment had additional antitumor activity only when combined with sorafenib and AMD3100 and not when combined with sorafenib alone. CONCLUSION: Anti-PD-1 treatment can boost antitumor immune responses in HCC models; when used in combination with sorafenib, anti-PD-1 immunotherapy shows efficacy only with concomitant targeting of the hypoxic and immunosuppressive microenvironment with agents such as CXCR4 inhibitors.


Asunto(s)
Antineoplásicos/uso terapéutico , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/inmunología , Inmunoterapia/métodos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/inmunología , Niacinamida/análogos & derivados , Compuestos de Fenilurea/uso terapéutico , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/uso terapéutico , Receptores CXCR4/antagonistas & inhibidores , Microambiente Tumoral/efectos de los fármacos , Microambiente Tumoral/inmunología , Animales , Humanos , Ratones , Niacinamida/uso terapéutico , Sorafenib
14.
Neuron ; 82(3): 573-86, 2014 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-24726382

RESUMEN

Menthol and other counterstimuli relieve itch, resulting in an antipruritic state that persists for minutes to hours. However, the neural basis for this effect is unclear, and the underlying neuromodulatory mechanisms are unknown. Previous studies revealed that Bhlhb5(-/-) mice, which lack a specific population of spinal inhibitory interneurons (B5-I neurons), develop pathological itch. Here we characterize B5-I neurons and show that they belong to a neurochemically distinct subset. We provide cause-and-effect evidence that B5-I neurons inhibit itch and show that dynorphin, which is released from B5-I neurons, is a key neuromodulator of pruritus. Finally, we show that B5-I neurons are innervated by menthol-, capsaicin-, and mustard oil-responsive sensory neurons and are required for the inhibition of itch by menthol. These findings provide a cellular basis for the inhibition of itch by chemical counterstimuli and suggest that kappa opioids may be a broadly effective therapy for pathological itch.


Asunto(s)
Dinorfinas/metabolismo , Interneuronas/metabolismo , Inhibición Neural/fisiología , Células del Asta Posterior/metabolismo , Prurito/metabolismo , Prurito/prevención & control , Analgésicos Opioides/farmacología , Analgésicos Opioides/uso terapéutico , Animales , Capsaicina/farmacología , Dinorfinas/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Octreótido/farmacología , Técnicas de Cultivo de Órganos , Receptores Opioides kappa/agonistas , Médula Espinal/metabolismo
15.
Circ Arrhythm Electrophysiol ; 6(5): 976-83, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24046327

RESUMEN

BACKGROUND: Vasoactive intestinal polypeptide (VIP) is released from intracardiac neurons during vagal stimulation, ischemia, and heart failure, which are associated with increased vulnerability to atrial fibrillation. VIP shortens atrial effective refractory periods in dogs. Endogenous VIP contributes to vagally mediated acceleration of atrial electric remodeling. VIP is also shown to prolong the duration of acetylcholine-induced atrial fibrillation. However, the ionic mechanisms underlying VIP effects are largely unknown. METHODS AND RESULTS: The effects of VIP on transmembrane ion channels were studied in canine atrial cardiomyocytes using patch-clamp techniques. VIP increased delayed rectifier K+ current and L-type calcium current but decreased the transient outward K+ current and sodium current. Optical mapping technique was used to assess effects of VIP on action potential durations (APDs) in isolated canine left atria. VIP shortened APD and slowed conduction velocity in a dose-dependent manner. Furthermore, VIP increased spatial heterogeneity of APD and conduction velocity, as assessed by the SDs of APD and conduction velocity, and atrial fibrillation inducibility. CONCLUSIONS: Through its diverse effects on ion channels, VIP shortens APD with increased APD spatial heterogeneity and decreases intra-atrial conduction velocity, which may play an important role in the pathogenesis of atrial arrhythmias in scenarios where VIP release is increased.


Asunto(s)
Fibrilación Atrial/tratamiento farmacológico , Fibrilación Atrial/fisiopatología , Atrios Cardíacos/efectos de los fármacos , Atrios Cardíacos/fisiopatología , Péptido Intestinal Vasoactivo/farmacología , Potenciales de Acción , Animales , Canales de Calcio/metabolismo , Perros , Atrios Cardíacos/metabolismo , Sistema de Conducción Cardíaco/metabolismo , Miocitos Cardíacos/metabolismo , Técnicas de Placa-Clamp , Canales de Potasio/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...