Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
5.
Eur Urol ; 75(5): 861-867, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30591353

RESUMEN

The role of percutaneous renal tumour biopsy (RTB) in the management of radiological indeterminate renal masses is long established. Patients with small renal masses who have biopsy-proven renal cell carcinoma (RCC) may be offered surgery, ablative therapy, or active surveillance, and RTB can provide diagnostic tissue from patients with metastatic disease who might benefit from systemic therapy. Current guidelines suggest that tumour seeding along the needle tract is anecdotal, but several cases have been reported recently, although some have been associated with lack of a coaxial sheath. We report on seven patients who underwent surgical resection of RCC in our tertiary referral institution following diagnostic RTB between 2014 and 2017 for whom RTB tract seeding by tumour was identified on histological examination of the resection specimen. One of these patients subsequently developed local tumour recurrence at the site of the previous biopsy.


Asunto(s)
Carcinoma de Células Renales/diagnóstico , Neoplasias Renales/diagnóstico , Recurrencia Local de Neoplasia/etiología , Recurrencia Local de Neoplasia/patología , Siembra Neoplásica , Adulto , Anciano , Biopsia con Aguja/efectos adversos , Biopsia con Aguja/métodos , Carcinoma de Células Renales/patología , Carcinoma de Células Renales/cirugía , Femenino , Humanos , Riñón/patología , Neoplasias Renales/patología , Neoplasias Renales/cirugía , Masculino , Persona de Mediana Edad , Centros de Atención Terciaria , Reino Unido
6.
J Urol ; 201(3): 510-519, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30266332

RESUMEN

PURPOSE: We hypothesized that 1) introducing prebiopsy multiparametric magnetic resonance imaging would increase the diagnostic yield of transrectal prostate biopsy and 2) this would inform recommendations regarding systematic transrectal prostate biopsy in the setting of negative prebiopsy multiparametric magnetic resonance imaging. MATERIALS AND METHODS: A total of 997 biopsy naïve patients underwent transrectal prostate biopsy alone to June 2016 (cohort 1) and thereafter 792 underwent transrectal prostate biopsy following prebiopsy multiparametric magnetic resonance imaging (cohort 2). Patients with lesions on prebiopsy multiparametric magnetic resonance imaging underwent cognitive targeted plus systematic transrectal prostate biopsy. Patients without lesions underwent systematic transrectal prostate biopsy. RESULTS: Cohort 2 comprised younger men (age 68 vs 69 years, p = 0.01) with lower prostate specific antigen (7.6 vs 7.9 ng/ml, p = 0.024) and smaller prostate volume (56.1 vs 62 cc, p = 0.006). In cohort 2 vs cohort 1 there was no increase in overall prostate cancer detection (57.6% vs 56.7%, p = 0.701), the Gleason Grade Group or the number of positive cores (each p >0.05). Increased multifocal prostatic intraepithelial neoplasia, maximum prostate cancer core length (5 mm or greater vs less than 5 mm) and radical surgery/high intensity focused ultrasound (each p <0.05) were observed in cohort 2. For Gleason Grade Group 2-5 prostate cancer negative prebiopsy multiparametric magnetic resonance imaging had 88.1% sensitivity, 59.8% specificity, 67.8% positive predictive value and 84% negative predictive value. For negative prebiopsy multiparametric magnetic resonance images a prostate specific antigen density cutoff of 0.15 ng/ml2 or greater increased clinically significant prostate cancer detection only if the latter was defined as Gleason Grade Group 3-5 disease and/or tumor length 6 mm or greater. CONCLUSIONS: Introducing prebiopsy multiparametric magnetic resonance imaging in our clinical setting increased the diagnostic yield of prostate cancer per biopsy core. Not performing a systematic transrectal prostate biopsy when prebiopsy multiparametric magnetic resonance imaging was negative would have led to under detection of 15.1% of Gleason Grade Group 2 or greater prostate cancer cases (approximately 1 in 6).


Asunto(s)
Imagen por Resonancia Magnética , Próstata/diagnóstico por imagen , Próstata/patología , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Anciano , Biopsia , Estudios de Cohortes , Humanos , Masculino , Periodo Preoperatorio
7.
Clin Genitourin Cancer ; 16(3): 240-244, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29336917

RESUMEN

BACKGROUND: Stage 1 seminoma is frequently cured by radical orchiectomy; however, the management strategies after this diagnosis vary in terms of the use of adjuvant treatment and the nature of the follow-up protocols. We analyzed stage 1 seminomas treated in the Thames Valley Cancer Network for outcomes to determine whether any factors are predictive of recurrence. We also studied relapses to determine the optimal follow-up schedule and protocol. MATERIALS AND METHODS: Data were obtained from centers within the Thames Valley Cancer Network for a 12-year period from 2004 to 2016. We identified 501 patients with stage 1 seminoma. RESULTS: Relapses occurred in 6.2% of the patients receiving adjuvant treatment and 6.1% of those who did not. The only statistically significant predictive factor identified for relapse was rete testis invasion, and the risk was greater when only stromal rete invasion was included, rather than pagetoid as well. A trend was seen toward an increased risk with increased tumor size, but the difference was not statistically significant. Recurrences developed within the first 2 years after surgery in nearly 75% of cases and were identified through surveillance computed tomography scans in 54.8% of the patients. All relapses were treated curatively. CONCLUSION: Active surveillance leads to excellent outcomes for stage 1 seminoma; however, adjuvant treatment should be reserved for those with high-risk disease. Follow-up schedules should include computed tomography imaging during the first 3 years, long-term measurement of tumor markers, and mechanisms for patients to be seen promptly should symptoms of tumor recurrence occur.


Asunto(s)
Recurrencia Local de Neoplasia/epidemiología , Seminoma/tratamiento farmacológico , Neoplasias Testiculares/cirugía , Espera Vigilante/métodos , Adulto , Quimioterapia Adyuvante , Humanos , Masculino , Orquiectomía , Guías de Práctica Clínica como Asunto , Estudios Prospectivos , Radioterapia Adyuvante , Análisis de Supervivencia , Neoplasias Testiculares/tratamiento farmacológico , Tomografía Computarizada por Rayos X , Carga Tumoral
8.
Curr Vasc Pharmacol ; 14(2): 163-7, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26638795

RESUMEN

Erectile dysfunction (ED) affects approximately half of men during middle age. Erectile dysfunction is often an early symptom of systemic vascular disease, which may precipitate significant cardiac events. The pathophysiology of ED and cardiovascular disease is closely linked. Endothelial dysfunction occurs at an early stage in ED and cardiovascular disease (CVD). In normal conditions, nitric oxide dependent and independent mechanisms regulate penile vascular tone ensuring an appropriate balance of vasoconstriction and vasodilatation. A normal endothelium is responsible for mediating the effect of pro-erectile mediators derived from the endothelium and is critical in normal erectile function. Endothelial dysfunction disrupts the homeostatic mechanisms responsible for regulation of smooth muscle contraction and penile vascular tone. Reduced bioavailability of nitric oxide (NO) occurs as a response to endothelial damage. Phosphodiesterases further degrade levels of cyclic guanosine monophosphate (cGMP) and impair smooth muscle relaxation and erectile function. A number of endothelium derived NO independent mediators of erectile function have been described and are known to contribute to ED in the presence of endothelial damage. This review provides an up to date analysis of the role of the endothelium in ED describing the pathways involved and how these represent current and potential therapeutic targets.


Asunto(s)
Endotelio Vascular/metabolismo , Disfunción Eréctil/metabolismo , Erección Peniana/fisiología , Vasodilatación/fisiología , Animales , Endotelio Vascular/patología , Disfunción Eréctil/patología , Humanos , Masculino , Estrés Oxidativo/fisiología , Vasoconstricción/fisiología
9.
BJU Int ; 107(8): 1290-6, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21929519

RESUMEN

UNLABELLED: Study Type--Therapy (case series) Level of Evidence What's known on the subject? and What does the study add? Renal cancer is increasingly diagnosed when tumours are small and asymptomatic, during routine abdominal imaging. Whilst surgery is an effective and potentially curative option, it carries a significant risk of complications. Recent work suggests that thermally ablative therapies (RFA, cryotherapy, HIFU) may be suitable minimally invasive treatment options in selected patients. The success of extracorporeal HIFU has been limited by the abdominal wall and rib-cage limiting energy delivery. For this study, a purpose-built laparoscopic HIFU probe was designed to allow direct application of the transducer to the tumour surface, thus facilitating tumour destruction. Successful and accurate tumour destruction was demonstrated, paving the way for further clinical trials, subject to device modifications. OBJECTIVE: • To test and establish clinical proof of concept for a laparoscopic high-intensity focused ultrasound (HIFU) device that facilitates delivery of ultrasound by direct application of a probe to the tumour surface. PATIENTS AND METHODS: • Twelve patients with renal tumours were treated with laparoscopic HIFU using a newly designed probe inserted via an 18-mm laparoscopic port. • HIFU treatment was targeted at a pre-defined proportion of the tumour and immediate laparoscopic partial or radical nephrectomy was then performed. RESULTS: • No tumour ablation was seen in the first five patients which made modifications in the treatment protocol necessary. After this, definite histological evidence of ablation was seen in the remaining seven patients. • The ablated zones were within the targeted area in all patients and no intra-lesional skipping was seen. • Subcapsular skipping was seen at the probe-tumour interface in two patients with viable tumour cells seen at microscopy. • One patient did not undergo surgical extirpation; subsequent biopsy revealed no viable tumour cells. • There were no intraoperative or postoperative complications directly related to HIFU therapy and patients have reached a mean (range) follow-up of 15 (8-24) months with no evidence of metastatic disease or late complications. CONCLUSIONS: • Tumour ablation with laparoscopic HIFU is feasible. • Homogenous ablation can be achieved with no vital tissue within the targeted zone. • The technique is associated with low morbidity and may have a role in the definitive management of small tumours.


Asunto(s)
Carcinoma de Células Renales/terapia , Neoplasias Renales/terapia , Laparoscopía , Terapia por Ultrasonido/métodos , Anciano , Anciano de 80 o más Años , Carcinoma de Células Renales/diagnóstico por imagen , Carcinoma de Células Renales/patología , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Renales/diagnóstico por imagen , Neoplasias Renales/patología , Masculino , Persona de Mediana Edad , Nefrectomía/métodos , Resultado del Tratamiento , Ultrasonografía
10.
Thromb Res ; 122(4): 533-40, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18539312

RESUMEN

Antiplatelet drugs are used to prevent aberrant platelet activation in pathophysiologic conditions such as myocardial infarction and ischemic stroke. The key role that ADP plays in this process has led to the development of antiplatelet drugs that target the P2Y12 receptor. The aim of this study was to characterize the pharmacodynamic (PD) and pharmacokinetic (PK) properties of the novel P2Y12 receptor antagonists, BX 667 and BX 048. BX 667 blocks ADP-induced platelet aggregation in human, dog and rat blood (IC50=97, 317 and 3000 nM respectively). BX 667 had nominal effects on collagen-induced aggregation and weakly inhibited arachidonic acid-induced aggregation. BX 667 has an active metabolite, BX 048, that also potently inhibits ADP-induced aggregation (IC50=290 nM) in human blood. BX 667 was shown to have high oral bioavailability in both dog and rat unlike BX 048. Administration of BX 667 resulted in a rapid and sustained inhibition of platelet aggregation where the extent and duration of platelet inhibition was directly proportional to circulating plasma levels. This report describes the PK/PD properties of BX 667 showing that it has the properties required for a potential antiplatelet therapeutic agent.


Asunto(s)
Plaquetas/efectos de los fármacos , Plaquetas/metabolismo , Cetoácidos/farmacocinética , Inhibidores de Agregación Plaquetaria/farmacocinética , Antagonistas del Receptor Purinérgico P2 , Quinolinas/farmacocinética , Receptores Purinérgicos P2/metabolismo , Animales , Perros , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Humanos , Ligandos , Masculino , Modelos Biológicos , Agregación Plaquetaria/efectos de los fármacos , Unión Proteica , Ratas , Receptores Purinérgicos P2Y12 , Especificidad de la Especie
11.
Thromb Res ; 122(4): 523-32, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18495218

RESUMEN

ADP plays a key role in platelet aggregation which has led to the development of antiplatelet drugs that target the P2Y12 receptor. The aim of this study was to characterize the effects of two novel P2Y12 receptor antagonists, BX 667 and its active metabolite BX 048, on platelets. BX 667 and BX 048 block the binding of 2MeSADP to platelets and antagonize ADP-induced platelet aggregation in human, dog and rat washed platelets. Both compounds were shown to be reversible inhibitors of platelet aggregation. BX 048 prevents the decrease in cAMP induced by treatment of platelets with ADP. The specificity of BX 667 and BX 048 was demonstrated against cell lines expressing P2Y1 and P2Y6 as well as against a panel of receptors and enzymes. Taken all together these data show that both BX 048 and BX 667 are potent P2Y12 antagonists with high specificity which, in the accompanying paper are demonstrated to behave predictably in vivo.


Asunto(s)
Plaquetas/efectos de los fármacos , Plaquetas/metabolismo , Cetoácidos/farmacología , Inhibidores de Agregación Plaquetaria/farmacología , Antagonistas del Receptor Purinérgico P2 , Quinolinas/farmacología , Receptores Purinérgicos P2/metabolismo , Adenosina Difosfato/química , Animales , Calcio/metabolismo , Perros , Evaluación Preclínica de Medicamentos , Humanos , Técnicas In Vitro , Ligandos , Modelos Biológicos , Agregación Plaquetaria/efectos de los fármacos , Unión Proteica , Ratas , Receptores Purinérgicos P2Y12 , Especificidad de la Especie
12.
J Pharmacol Toxicol Methods ; 57(3): 220-6, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18396065

RESUMEN

Unscheduled DNA synthesis (UDS) has been used as an endpoint for measuring DNA damage in vitro and in vivo. Determination of UDS is regarded as a reliable genotoxicity assay by regulatory agencies including US FDA and EPA. In this study, we have developed an improved UDS assay to detect DNA damage and repair processes upon chemical exposure. We utilized a dual-labeling procedure in which fluorescent DAPI stained nuclei of live cells and [(3)H]thymidine labeled cells undergoing new DNA synthesis. The occurrence of UDS in cells was quantified by either manual nucleus counting or net intensity approaches. This assay was validated by testing known genotoxic compounds 2-acetylaminofluorene (2-AAF), ethylmethanesulfonate (EMS), and N-nitrosodimethylamine (NDL) in primary rat hepatocytes as well as in confluent human mammary epithelial cells. In addition, fluorescent labeling of nuclei DNA helped to distinguish apoptotic cells from non-apoptotic cells. Chemical effects on cell functions were also examined by conducting the cytotoxicity assay along with the UDS assay. To conclude, the dual-labeling UDS assay offers advantages of reduced subjective bias, increasing sensitivity and reproducibility. The assay is suitable for testing compounds in higher capacity format with much less compound needed.


Asunto(s)
Daño del ADN , ADN/biosíntesis , Pruebas de Mutagenicidad/métodos , Mutágenos/toxicidad , Mutación/efectos de los fármacos , Animales , Autorradiografía , Núcleo Celular/química , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , ADN/efectos de los fármacos , Replicación del ADN/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Femenino , Colorantes Fluorescentes/química , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Humanos , Indoles/química , Glándulas Mamarias Humanas/citología , Glándulas Mamarias Humanas/metabolismo , Mutación/genética , Ratas , Reproducibilidad de los Resultados , Timidina/metabolismo , Tritio
13.
Atherosclerosis ; 197(1): 204-11, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17466308

RESUMEN

Atherosclerotic vascular disease is an inflammatory disease. Interferon-beta (IFN-beta) is an important immune modulator. However, the role of IFN-beta in atherosclerotic vascular disease is still not clear. The present study is designed to determine the effects of IFN-beta on atherosclerosis, abdominal aortic aneurysm (AAA) formation and proliferative vascular remodeling in apolipoprotein E (apoE) deficient mice. Six-month-old male apoE deficient mice fed a normal chow underwent ligation of the common left carotid artery, and were randomly assigned to receive either vehicle or angiotensin II (Ang II, 1.4 mg/kg daily) via a subcutaneously implanted osmotic infusion pump. The animals were further assigned to groups that were subjected to subcutaneous injection of vehicle or murine IFN-beta (10 MIU/kg, daily). Ang II increased atherosclerotic area in the non-ligated carotid artery and aortic arch, induced AAA, and exacerbated ligation-induced adventitial proliferation and neointimal hyperplasia characterized by smooth muscle cell (SMC) proliferation and macrophage infiltration in the ligated carotid artery. Co-treatment with IFN-beta, had no effects by itself, significantly attenuated Ang II-accelerated increase in the areas of neointima, adventitia, SMC and macrophage in the ligated carotid artery and suppressed Ang II-exacerbated atherosclerosis, but did not affect Ang II-induced AAA formation. These data indicate that IFN-beta can play a prominent anti-atherosclerosis, anti-inflammation, and anti-proliferation role of vasculoprotection.


Asunto(s)
Angiotensina II/farmacología , Apolipoproteínas E/genética , Aterosclerosis/tratamiento farmacológico , Factores Inmunológicos/farmacología , Interferón beta/farmacología , Vasoconstrictores/farmacología , Animales , Aorta Torácica/efectos de los fármacos , Aorta Torácica/inmunología , Aorta Torácica/patología , Aneurisma de la Aorta Abdominal/tratamiento farmacológico , Aneurisma de la Aorta Abdominal/inmunología , Aneurisma de la Aorta Abdominal/patología , Aterosclerosis/inmunología , Aterosclerosis/patología , Arteria Carótida Común/efectos de los fármacos , Arteria Carótida Común/inmunología , Arteria Carótida Común/patología , División Celular/efectos de los fármacos , Interacciones Farmacológicas , Células Espumosas/patología , Ligadura , Masculino , Ratones , Ratones Mutantes , Túnica Íntima/efectos de los fármacos , Túnica Íntima/inmunología , Túnica Íntima/patología
14.
Arthritis Res Ther ; 9(6): R123, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-18036238

RESUMEN

Murine collagen-induced arthritis (CIA) has become a valuable animal model for elucidating pathogenic mechanisms and evaluating therapeutic effects for rheumatoid arthritis. Recent advances in digital imaging and computer technology have enabled gait analysis to develop into a powerful tool for objectively detecting functional deficits in human and animal models. The present study explored the use of non-invasive video-capture gait analysis in the evaluation of a murine CIA model. CIA was induced in 45 female DBA/1LacJ mice (8 to 10 weeks old) by immunization with lyophilized bovine articular type II collagen. Gait parameters were determined by ventral plane videography and were correlated to traditional arthritis clinical scores. Our results showed that increases in clinical scores that measure the severity of CIA corresponded to changes in multiple gait parameters that reflect both morphologic (increases in paw area) and functional (increase in stride frequency, decrease in stride length, hind-limb paw placement angle, as well as stride, stance, and braking times) deficits. Our work indicated that the non-invasive video-capture device may be used as a simple and objective data acquisition system for quantifying gait disturbances in CIA mice for the investigation of mechanisms and the evaluation of therapeutic agents.


Asunto(s)
Artritis Experimental/fisiopatología , Marcha/fisiología , Cojera Animal/fisiopatología , Animales , Artritis Experimental/complicaciones , Artritis Reumatoide/fisiopatología , Fenómenos Biomecánicos , Femenino , Humanos , Cojera Animal/etiología , Ratones , Ratones Endogámicos DBA , Factores de Tiempo , Grabación en Video
16.
Cardiovasc Pathol ; 16(4): 231-6, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17637431

RESUMEN

BACKGROUND: Angiotensin II (Ang II) promotes atherosclerotic vascular diseases, in which proinflammatory and proliferative effects play a major pathogenic role. Ang II up-regulates chemokines, such as monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha, which are important pro-inflammatory factors mediating infiltration of inflammatory cells into atherosclerotic lesion. The aim of the present study was to determine whether the presence of MCP-1 or MIP-1alpha is essential in Ang II-induced intimal hyperplasia in the carotid artery ligation model. METHODS: Six-month-old male C57BL/6-, MCP-1-, or MIP-1alpha-deficient mice underwent ligation of the common left carotid artery and were randomly assigned to receive either vehicle or Ang II (1.4 mg kg(-1) day(-1)) via a subcutaneously implanted osmotic infusion pump (model 2004, Alzet) for 4 weeks. RESULTS: Ang II not only increased MCP-1 and MIP-1alpha production but also enhanced neo-intimal formation, media thickness, and adventitia development in the ligated carotid arteries in C57BL/6 mice. However, MCP-1 or MIP-1alpha deficiency failed to affect intimal hyperplasia in vascular remodeling. CONCLUSION: These results indicate that MCP-1 or MIP-1alpha may not be essential in mediating the proliferative effects of Ang II, a major pathological changes in intimal hyperplasia in the carotid artery ligation model.


Asunto(s)
Angiotensina II/metabolismo , Arterias Carótidas/metabolismo , Quimiocina CCL2/metabolismo , Proteínas Inflamatorias de Macrófagos/metabolismo , Túnica Íntima/patología , Animales , Arterias Carótidas/patología , Traumatismos de las Arterias Carótidas/metabolismo , Traumatismos de las Arterias Carótidas/patología , Quimiocina CCL3 , Quimiocina CCL4 , Hiperplasia , Inmunohistoquímica , Ligadura , Masculino , Ratones , Ratones Endogámicos C57BL , Túnica Íntima/metabolismo
17.
J Med Chem ; 50(13): 2967-80, 2007 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-17536795

RESUMEN

There remains a high unmet medical need for a safe oral therapy for thrombotic disorders. The serine protease factor Xa (fXa), with its central role in the coagulation cascade, is among the more promising targets for anticoagulant therapy and has been the subject of intensive drug discovery efforts. Investigation of a hit from high-throughput screening identified a series of thiophene-substituted anthranilamides as potent nonamidine fXa inhibitors. Lead optimization by incorporation of hydrophilic groups led to the discovery of compounds with picomolar inhibitory potency and micromolar in vitro anticoagulant activity. Based on their high potency, selectivity, oral pharmacokinetics, and efficacy in a rat venous stasis model of thrombosis, compounds ZK 814048 (10b), ZK 810388 (13a), and ZK 813039 (17m) were advanced into development.


Asunto(s)
Amidas/síntesis química , Aminopiridinas/síntesis química , Anticoagulantes/síntesis química , Inhibidores del Factor Xa , Tiofenos/síntesis química , ortoaminobenzoatos/síntesis química , Amidas/farmacocinética , Amidas/farmacología , Aminopiridinas/farmacocinética , Aminopiridinas/farmacología , Animales , Anticoagulantes/farmacocinética , Anticoagulantes/farmacología , Cristalografía por Rayos X , Perros , Humanos , Técnicas In Vitro , Masculino , Modelos Moleculares , Tiempo de Protrombina , Ratas , Ratas Wistar , Relación Estructura-Actividad , Tiofenos/farmacocinética , Tiofenos/farmacología , Trombosis de la Vena/tratamiento farmacológico , ortoaminobenzoatos/farmacocinética , ortoaminobenzoatos/farmacología
18.
Thromb Haemost ; 97(5): 847-55, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17479197

RESUMEN

Irreversible platelet inhibitors, such as aspirin and clopidogrel, have limited anti-thrombotic efficacy in the clinic due to their bleeding risk. We have developed an orally active reversible P2Y(12) receptor antagonist, BX 667. The aim of this study was to determine if the reversible antagonist BX 667 had a greater therapeutic index than the irreversible P2Y(12) receptor antagonist clopidogrel. Since BX 667 is rapidly converted to its active metabolite BX 048 in rats, we first injected BX 048 intravenously (iv) in a rat arterial venous (A-V) shunt model of thrombosis. BX 048 dose- and concentration-dependently attenuated thrombosis. When administered orally, BX 667 and clopidogrel had similar efficacy, but BX 667 caused less bleeding than clopidogrel. In a rat model of a platelet-rich thrombus induced by vessel injury with FeCl(2), both BX 667 and clopidogrel exhibited higher levels of thrombus inhibition after oral administration compared to their potency in the A-V shunt model. Again, BX 667 caused less bleeding than clopidogrel. In a dog cyclic flow model, iv injection of either BX 667 or clopidogrel dose-dependently reduced thrombus formation with lower bleeding for BX 667 than clopidogrel. Inhibition of thrombosis was highly correlated with inhibition of ADP-induced platelet aggregation in these animal models. In dogs pre-treated with aspirin, BX 667 maintained its wider therapeutic index, measured by inhibition of platelet aggregation over bleeding, compared to the aspirin-clopidogrel combination. These data demonstrate that the reversible P2Y(12) receptor antagonist, BX 667, has a wider therapeutic index than clopidogrel in experimental models of thrombosis.


Asunto(s)
Proteínas de la Membrana/antagonistas & inhibidores , Inhibidores de Agregación Plaquetaria/farmacología , Agregación Plaquetaria/efectos de los fármacos , Antagonistas del Receptor Purinérgico P2 , Trombosis/prevención & control , Animales , Derivación Arteriovenosa Quirúrgica , Traumatismos de las Arterias Carótidas/tratamiento farmacológico , Clopidogrel , Modelos Animales de Enfermedad , Perros , Técnicas In Vitro , Masculino , Estructura Molecular , Inhibidores de Agregación Plaquetaria/sangre , Inhibidores de Agregación Plaquetaria/química , Ratas , Ratas Sprague-Dawley , Receptores Purinérgicos P2 , Receptores Purinérgicos P2Y12 , Ticlopidina/análogos & derivados , Ticlopidina/farmacología
19.
Am J Physiol Heart Circ Physiol ; 293(1): H69-76, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17434974

RESUMEN

The present study tested the hypothesis that murine (m)IFN-beta or mIFN-alpha(2) can eliminate cardiac viral load and protect cardiomyocytes from injury in animals infected with coxsackievirus B3 (CVB3). CVB3-inoculated male Balb/c mice exhibited signs of illness, including lethargy, progressive weight loss, and death (10% on day 3 and 100% on day 8). Cardiac viral load was high [4,277 +/- 1,009 plaque-forming units and 25 +/- 5 copies CVB3/hypoxanthine guanine phosphoribosyl transferase 1 mRNA] on day 4. The cardiac tissue exhibited severe inflammatory infiltration and myocyte damage with an average myocarditis integrated pathology score of 2.1 +/- 0.2 on day 7. Most of the mice infected with CVB3 also developed epicarditis, and 55% had intraventricular thrombi present. Treatment with mIFN-beta [2.5 to 10 million international units (MIU)/kg] dose-dependently improved the general health status in CVB3-inoculated mice, as evidenced by reduction in weight loss, prevention of death, elimination of cardiac viral load, protection of myocytes from injury, decrease in inflammatory cell infiltration, and attenuation of intraventricular thrombus formation. Treatment with 10 MIU/kg mIFN-alpha(2) resulted in a similar level of efficacy as that induced by 5 MIU/kg mIFN-beta, with the exception that mIFN-alpha(2) did not reduce cardiac CVB3 mRNA. However, mIFN-alpha(2) , but not any dose group of mIFN-beta, significantly attenuated CVB3-induced epicarditis. These data demonstrate antiviral effects for both mIFN-beta and mIFN-alpha(2), which lead to protection of the mice from CVB3-induced myocarditis. However, the potential mechanisms leading to a differential host response for the two isoforms of mIFN remain to be elucidated.


Asunto(s)
Enterovirus/efectos de los fármacos , Interferón-alfa/administración & dosificación , Interferón beta/administración & dosificación , Miocarditis/tratamiento farmacológico , Miocarditis/virología , Pericardio/efectos de los fármacos , Pericardio/virología , Animales , Antivirales/administración & dosificación , Cardiotónicos/administración & dosificación , Células Cultivadas , Masculino , Ratones , Ratones Endogámicos BALB C , Células Musculares/efectos de los fármacos , Células Musculares/virología , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...