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1.
Surg Endosc ; 33(6): 1769-1776, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30291444

RESUMEN

BACKGROUND: The number of colorectal cancer cases is increasing, and so the number of laparoscopic colectomy procedures being performed is also increasing, leading to an increased workload for surgeons. However, operating for prolonged time periods may cause surgeons to lose their concentration and develop fatigue. We hypothesized that there is a time-of-day variation in outcome for patients with colorectal cancer who undergo laparoscopic colectomy. The present study aimed to compare the operative outcome between laparoscopic colectomy for colorectal cancer performed in the morning versus the afternoon. METHODS: This was a single-center, retrospective study. All 1961 consecutive patients who underwent laparoscopic surgery for colorectal cancer between 2007 and 2017 were included; 1006 of these patients underwent morning surgery, while 955 underwent afternoon surgery. These patients were analyzed using propensity score matching, giving 791 patients in each group. The short- and long-term outcomes in both groups were compared. RESULTS: Before propensity score matching, the morning group had a larger mean tumor size than the afternoon group (30 cm vs 35 cm; P = 0.0035). After matching, the two groups did not significantly differ in any patient characteristics. Compared with the afternoon group, the morning group had a significantly lesser incidence of intra-operative organ injury (0.25% vs 1.13%; P = 0.027), and a significantly greater incidence of post-operative abdominal abscess (2.03% vs 0.75% P = 0.028). The incidences of other complications and morbidities were similar in both groups. The median operative time in the morning group (201 min) was significantly longer than that in the afternoon group (193 min; P = 0.0124). The two groups did not differ in 5-year overall survival rates and 5-year disease-free rates within any disease stage. CONCLUSIONS: Surgical start times are correlated with surgical outcomes. Our data will help to ensure the safest possible surgeries.


Asunto(s)
Neoplasias Colorrectales/cirugía , Tempo Operativo , Anciano , Anciano de 80 o más Años , Colectomía , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Femenino , Humanos , Incidencia , Japón/epidemiología , Laparoscopía , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Puntaje de Propensión , Estudios Retrospectivos , Análisis de Supervivencia
2.
Curr Oncol ; 24(4): e328-e332, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28874903

RESUMEN

Despite progressive treatments with tandem stem-cell transplantation, patients with incurable myeloma eventually succumb to relapsed or refractory disease if left untreated. Promising agents such as proteasome inhibitors and immunomodulating imide drugs (imids), including the newer-generation agent pomalidomide, in combination with lower-dose dexamethasone, have been shown to be effective and to significantly improve and prolong survival in pretreated patients. Although the incidence of pomalidomide hypersensitivity reaction (hsr) in this class of drugs is not as well known, we have documented cutaneous toxicity (grade 3 by the Common Terminology Criteria for Adverse Events, version 4) in 2 separate cases (not yet published). Because the imids are chemically, structurally, and pharmacologically similar, it is not unreasonable to consider possible cross-reactivity in pomalidomide recipients who developed hsr when receiving previous lines of imids. As a patient's advocate, it is only prudent to provide a responsible, and yet practical, means to better address cross-sensitivity for patients. Intervention with the use of a rapid desensitization program (rdp) as a preventive measure should be introduced before initiating pomalidomide. Such a proactive measure for the patient's safety will ensure a smooth transition into pomalidomide treatment. A hsr can be either related or non-related to immunoglobulin E. As imids become an essential treatment backbone for myeloma and other plasma-cell diseases, an increasing number of patients could experience skin and other life-threatening toxicities, resulting in unnecessary discontinuation of these life-prolonging agents. An extemporaneously prepared pomalidomide suspension developed at our centre enables patients to undergo rdp safely. Patients enjoy a good quality of life and clinical response after the rdp procedure.

3.
Curr Oncol ; 23(4): e355-61, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27536184

RESUMEN

BACKGROUND: Venous thromboembolism (vte) is a recognized complication in patients treated with asparaginase-containing chemotherapy regimens; the optimal preventive strategy is unclear. We assessed the safety and efficacy of prophylaxis using low-dose low molecular weight heparin in adult patients with acute lymphoblastic leukemia in complete remission treated with an asparaginase-based post-remission chemotherapy regimen. METHODS: As part of the intensification phase of the Dana-Farber Cancer Institute 91-01 regimen, asparaginase was administered weekly to 41 consecutive patients for 21-30 weeks; these patients also received prophylaxis with enoxaparin 40 mg daily (60 mg for patients ≥80 kg). Outcomes were assessed against outcomes in a comparable cohort of 99 patients who received the same chemotherapy regimen without anticoagulation prophylaxis. RESULTS: The overall rate of symptomatic venous thrombosis was not significantly different in the prophylaxis and non-prophylaxis cohorts (18.92% and 21.74% respectively). Among patients receiving prophylaxis, vte occurred in higher proportion in those who weighed at least 80 kg (42.86% vs. 4.35%, p = 0.0070). No major bleeding complications occurred in the prophylaxis group (minor bleeding: 8.1%). CONCLUSIONS: Prophylaxis with low-dose enoxaparin during the intensification phase was safe, but was not associated with a lower overall proportion of vte.

4.
Curr Oncol ; 22(5): e357-63, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26628876

RESUMEN

BACKGROUND: Keratoconjunctivitis sicca from chronic graft-versus-host disease (cgvhd) after allogeneic stem cell transplantation is common, leading to severe corneal damage and blindness if not treated. We retrospectively examined the efficacy and safety of pooled human albumin eye drops (haeds) for symptom relief in 40 stem-cell transplantation patients after other alternatives had failed. METHODS: The Common Terminology Criteria for Adverse Events (version 4.0) and the cgvhd grading scale were used to compare response in the patients during January 2000 and July 2013. In addition, on days 1 and 30, the haeds were subjected to quality assurance testing for sterility, oncotic pressure, albumin measurement, viscosity, pH, and purity by protein electrophoresis. RESULTS: Use of haeds resulted in symptom relief for 37 patients (92.5%); 3 patients (7.5%) failed to improve with use of haeds (p ≤ 0.0001). Of the 37 patients having symptom relief, 7 (19%) improved from grade 3 to no dry eye symptoms. Proportionately, post-treatment symptom improvement by two grade levels, from 3 to 1 (70%), was significantly higher than improvement by one grade level, from 3 to 2 (11%) or from 2 to 1 (19%, p ≤ 0.0001). Time to symptom relief ranged from 2 weeks to 28 weeks. Of the 40 patients, 38 (95%) had no adverse reactions. Days 1 and 30 quality assurance testing results were equivalent. CONCLUSIONS: Complications of keratoconjunctivitis sicca were well managed and well tolerated with haeds when other remedies failed. Quality assurance testing confirmed that haeds were safe and stable in extreme conditions.

6.
Cancer Res ; 46(2): 907-16, 1986 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2416436

RESUMEN

For direct identification of phosphotyrosine-containing proteins in lysates of various cells, phosphotyrosine (P-Tyr) was coupled to carrier proteins and anti-P-Tyr antibodies were raised in rabbits and mice. The antibodies were highly specific for P-Tyr and did not cross-react with phosphoserine or phosphothreonine. The mean association constant of rabbit anti-P-Tyr antibody to N-acetyl-P-Tyr was about four times that of rabbit anti-azobenzene phosphonate antibody. In addition, anti-P-Tyr antibody scarcely cross-reacted with the 5'-monophosphate of ribosyladenine or the 5'-monophosphate of ribosylinosine, whereas anti-azobenzene phosphonate antibody cross-reacted appreciably with these compounds. Anti-P-Tyr antibody immunoprecipitated three oncogenic gene products from cells transformed with Rous sarcoma virus, Fujinami sarcoma virus, and Abelson murine leukemia virus, respectively. The immunoprecipitates with anti-P-Tyr antibody from cells transformed with these three retroviruses all manifested tyrosine kinase activity including activity for phosphorylations of oncogene products. In addition to the proteins reported previously, the following new phosphotyrosine-containing proteins were immunoprecipitated from the respective retrovirus-transformed cells by anti-P-Tyr antibody: Mr 230,000, 74,000, and 24,000 proteins (Rous sarcoma virus); Mr 230,000, 69,000, and 24,000 proteins (Fujinami sarcoma virus); and Mr 230,000, 62,000, and 54,000 proteins (Abelson murine leukemia virus).


Asunto(s)
Transformación Celular Viral , Fosfoproteínas/inmunología , Proteínas Tirosina Quinasas/metabolismo , Retroviridae , Tirosina/análogos & derivados , Animales , Anticuerpos/inmunología , Especificidad de Anticuerpos , Linfocitos B/metabolismo , Peso Molecular , Fosfoproteínas/análisis , Fosfotirosina , Tirosina/inmunología , Tirosina/metabolismo
7.
Oncogene ; 6(7): 1279-83, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1650446

RESUMEN

cDNA clones carrying the chicken-bek gene and a related gene were isolated. Deducing the amino acid sequence of chicken-bek allowed us to predict that it encodes for a receptor tyrosine kinase related to the fibroblast growth factor (FGF) receptor, and that the chicken-bek gene and Cek3 are closely related. However, a significant structural difference was identified between chicken-bek and Cek3 within the putative extracellular region, in such a manner that the structure of the immunoglobulin-like domain was conserved. A probe specific to the altered structure detected mRNA in the tissues as did a probe common to bek and Cek3, indicating heterogeneity in the FGF-receptor family in a novel manner. Furthermore, another bek-like gene was isolated and the expressions of its mRNA and protein product were analysed in tissues and cultured cells.


Asunto(s)
Proteínas Tirosina Quinasas/genética , Proteínas Tirosina Quinasas Receptoras , Receptores de Superficie Celular/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión , Embrión de Pollo , Pollos , ADN/genética , ADN/aislamiento & purificación , Expresión Génica , Humanos , Pulmón/metabolismo , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , ARN Mensajero/análisis , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos , Receptores de Superficie Celular/metabolismo , Receptores de Factores de Crecimiento de Fibroblastos , Homología de Secuencia de Ácido Nucleico
8.
Atherosclerosis ; 117(1): 97-106, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8546759

RESUMEN

The effect of FK409, a new nitric-oxide (NO) donor, on neointimal formation of rat carotid arteries following balloon injury was studied. The intimal thickening at 14 days was strongly suppressed by twice daily administration of FK409 at 10 mg/kg from 2 days before to 13 days after injury. The neointima area and neointima/media ratio were decreased by 48.0% (P < 0.01) and 38.5% (P < 0.01), respectively, compared with control. On the other hand, isosorbide dinitrate (ISDN), a classical nitro-vasodilator, did not suppress intimal thickening even at 100 mg/kg twice a day. An in vivo 5-bromo-2'-dedoxyuridine (BrdU) uptake study revealed that FK409 inhibited the proliferative response of smooth muscle cells (SMC) in media at early stage of injury. In fact, the neointimal formation at 14 days was inhibited by the short term administration of FK409 only from the day of injury to 4 days after at 10 mg/kg twice a day. In cultured rat SMC, FK409 (1-10 mumol/l) markedly enhanced intracellular c-GMP and inhibited the proliferation in 10% FBS-containing medium. These results suggest that FK409 suppresses intimal thickening following balloon injury of the rat carotid artery by inhibition of SMC proliferation.


Asunto(s)
Angioplastia de Balón/efectos adversos , Arterias Carótidas/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Óxido Nítrico/metabolismo , Nitrocompuestos/farmacología , Vasodilatadores/farmacología , Animales , Bromodesoxiuridina/metabolismo , Arterias Carótidas/patología , Traumatismos de las Arterias Carótidas , División Celular/efectos de los fármacos , Células Cultivadas , GMP Cíclico/metabolismo , Modelos Animales de Enfermedad , Dinitrato de Isosorbide/farmacología , Masculino , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patología , Ratas , Ratas Sprague-Dawley , Túnica Íntima/efectos de los fármacos , Túnica Íntima/patología
9.
Atherosclerosis ; 108(2): 159-65, 1994 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7980715

RESUMEN

The effect of TFC-612, methyl-6-[(1R,2S,3R)-hydroxy-2-](1E,3S,5R)-3- hydroxy-5-methyl-1-nonenyl]-5-oxocyclopentyl)thio] hexanoate, on intimal thickening of carotid artery 14 days after endothelium denudation with a balloon catheter was examined in rats. This compound significantly suppressed the neointimal area and the ratio of intimal and medial layer by 41.1% and 31.4%, respectively, at 3.2 micrograms/rat/h s.c. infusion. At this dose, this compound did not inhibit platelet aggregation induced by either collagen or ADP. It did not inhibit bromodeoxyuridine incorporation into medial smooth muscle cells at 3 days after injury. In in vitro experiments, TFC-612 did not inhibit the [3H]thymidine uptake into cultured smooth muscle cells, but it showed significant inhibition of smooth muscle cell migration induced by platelet-derived growth factor (PDGF) at more than 10(-9) M. This compound increased cyclic AMP levels dose dependently in cultured smooth muscle cells at more than 10(-8) M. These results suggest that TFC-612 inhibits intimal thickening by inhibition of smooth muscle cell migration from media to intima through cyclic AMP elevation.


Asunto(s)
Alprostadil/análogos & derivados , Cateterismo , Inhibidores de Agregación Plaquetaria/farmacología , Túnica Íntima/efectos de los fármacos , Alprostadil/farmacología , Animales , Bromodesoxiuridina/metabolismo , Traumatismos de las Arterias Carótidas , Arteria Carótida Común/patología , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Masculino , Músculo Liso Vascular/citología , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/metabolismo , Agregación Plaquetaria/efectos de los fármacos , Factor de Crecimiento Derivado de Plaquetas/farmacología , Ratas , Ratas Sprague-Dawley , Timidina/metabolismo , Túnica Íntima/lesiones , Túnica Íntima/patología , Túnica Íntima/fisiopatología
10.
Transplantation ; 65(8): 1132-4, 1998 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-9583878

RESUMEN

BACKGROUND: The immunosuppressants cyclosporine and FK506 have been used successfully in clinical transplantation, but both agents have various side effects. We have previously found that cyclosporine is prothrombotic and that FK506 is antithrombotic in an in vivo system. The aim of the present study was to assess the effects of these agents on platelet reactivity and coagulation using an in vitro shear-induced hemostatic platelet plug-forming instrument, the hemostatometer. METHODS: A purpose-built hemostatometer was constructed in our laboratory. The effects of cyclosporine and FK506 on platelet reactivity and coagulation were assessed under high shear stress using non-anticoagulated rat and human blood. RESULTS: FK506 significantly inhibited both platelet reactivity and coagulation. Cyclosporine also significantly inhibited coagulation, but a proaggregatory effect was observed at a final blood concentration of 0.05 mg/ml. CONCLUSIONS: The present in vitro results support our previous in vivo findings regarding the prothrombotic and antithrombotic effects of cyclosporine and FK506, respectively.


Asunto(s)
Plaquetas/fisiología , Ciclosporina/farmacología , Inhibidores de Agregación Plaquetaria/farmacología , Agregación Plaquetaria/efectos de los fármacos , Tacrolimus/farmacología , Adulto , Animales , Anticoagulantes , Coagulación Sanguínea/efectos de los fármacos , Coagulación Sanguínea/inmunología , Plaquetas/efectos de los fármacos , Humanos , Inmunosupresores/farmacología , Técnicas In Vitro , Masculino , Agregación Plaquetaria/inmunología , Agregación Plaquetaria/fisiología , Ratas , Ratas Wistar , Estrés Mecánico
11.
Transplantation ; 70(5): 774-9, 2000 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-11003356

RESUMEN

BACKGROUND: Posttransplantation osteopenia leading to osteoporosis induced commonly by treatment with immunosuppressants including cyclosporine (CsA) is a severe complication and results in lowering the quality of life in patients receiving organ transplantation. FK506 is a newly developed immunosuppressant and is currently being used for the prevention of rejection after organ transplantation. In this study, to investigate whether FK506 as well as CsA would cause osteopenia or not, we evaluated the effect of FK506 on bone mineral density and several parameters relevant to bone metabolism in comparison with that of CsA using normal rats. METHODS: Ten-week-old male Sprague-Dawley rats were treated with FK506 (vehicle, 1 mg/kg, and 3.2 mg/kg) or CsA (vehicle, 10 mg/kg, and 32 mg/kg) by daily oral gavage for 28 days. Bone mineral density of the femur, plasma insulin-like growth factor I (IGF-I), and urinary deoxypyridinoline were determined by peripheral quantitative computerized tomography, radioimmunoassay, and enzyme-linked immunosorbent assay, respectively. RESULTS: The reduction in bone mineral density of the femur was observed in both FK506- and CsA-treated rats. The reduction in CsA-treated rats, however, was statistically significant and strikingly severe, whereas that in FK506-treated rats was much less severe than CsA. Plasma IGF-I levels were significantly elevated in FK506-treated rats but not in CsAtreated rats. Urinary deoxypyridinoline levels were unchanged in FK506-treated rats but elevated in CsA-treated rats. CONCLUSIONS: Compared with CsA, FK506 does not appear to induce severe osteopenia by high-turnover bone metabolism in the rat by mediating via IGF-I induction in part. The results suggest that FK506 may exert favorable effects on bone metabolism in patients with organ transplantation compared with CsA. To assess this idea, further clinical investigations focused on bone metabolism will be required.


Asunto(s)
Densidad Ósea/efectos de los fármacos , Ciclosporina/farmacología , Inmunosupresores/farmacología , Tacrolimus/farmacología , Aminoácidos/orina , Animales , Ácidos y Sales Biliares/sangre , Bilirrubina/sangre , Biomarcadores/orina , Peso Corporal , Factor I del Crecimiento Similar a la Insulina/metabolismo , Factor I del Crecimiento Similar a la Insulina/farmacología , Masculino , Ratas , Ratas Sprague-Dawley
12.
Thromb Haemost ; 83(5): 722-7, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10823269

RESUMEN

Inhibitors of angiotensin converting enzyme (ACE) have been developed recently for therapeutic purposes in hypertension and ischemic cardiovascular diseases. Ogiku et al. reported that one such inhibitor, imidapril, significantly prolonged survival in stroke-prone spontaneously hypertensive rats (SHRSP). The present study was designed to investigate the effect of imidapril on cerebral blood vessels in SHRSP to clarify role of the ACE inhibitor in mechanisms of cerebral thrombosis and stroke. Imidapril was administered orally at 1.0 and 5.0 mg/kg/day for 3 weeks from the age of 7 weeks, and was shown to prevent the usual increase in blood pressure seen in these animals. It also delayed He-Ne laser-induced cerebral thrombosis and increased significantly the plasma concentration of nitric oxide metabolites (NO2/NO3). To confirm the association between nitric oxide (NO) and these effects of imidapril, an inhibitor of nitric oxide synthase, N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME) was dissolved in drinking water and administered to the animals for 3 weeks. Four of six rats died from stroke when L-NAME was given alone. When imidapril (5.0 mg/kg/day) was administered with L-NAME, however, the animals showed no signs or symptoms of stroke. In these instances, therefore, the concurrent administration of L-NAME with imidapril reversed significantly the effects of imidapril. Intravenous injection of imidaprilat (100 microg/kg), an active metabolite of imidapril, also decreased blood pressure significantly and increased the plasma levels of NO2/NO3 after 5 min. Moreover, imidaprilat enlarged arteriolar diameters and caused an increase in red cell velocity and mean blood flow in pial arterioles after 15 min. The results strongly suggested that imidapril protects cerebral vessels in SHRSP by elevating the release of NO, thereby improving the cerebral circulation and reducing the tendency to thrombosis and stroke.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Antihipertensivos/uso terapéutico , Imidazoles/uso terapéutico , Imidazolidinas , Trombosis Intracraneal/prevención & control , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Antihipertensivos/farmacología , Arteriolas/ultraestructura , Arterias Cerebrales/ultraestructura , Evaluación Preclínica de Medicamentos , Femenino , Predisposición Genética a la Enfermedad , Hemorreología/efectos de los fármacos , Hipertensión/genética , Hipertensión/prevención & control , Imidazoles/antagonistas & inhibidores , Imidazoles/farmacología , Trombosis Intracraneal/tratamiento farmacológico , Trombosis Intracraneal/genética , Rayos Láser/efectos adversos , Masculino , Microcirculación/efectos de los fármacos , NG-Nitroarginina Metil Éster/toxicidad , Óxido Nítrico/fisiología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Ratas , Ratas Endogámicas SHR
13.
Thromb Haemost ; 76(1): 111-7, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8819262

RESUMEN

Sodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1), are known to liberate nitric oxide (NO). In this study the effects of SNP and SIN-1 on thrombus formation in rat cerebral arterioles and venules in vivo were assessed using a helium-neon (He-Ne) laser. SNP infused at doses from 10 micrograms/kg/h significantly inhibited thrombus formation in a dose dependent manner. This inhibition of thrombus formation was suppressed by methylene blue. SIN-1 at a dose of 100 micrograms/kg/h also demonstrated a significant antithrombotic effect. Moreover, treatment with SNP increased vessel diameter in a dose dependent manner and enhanced the mean red cell velocity measured with a fiber-optic laser-Doppler anemometer microscope (FLDAM). Blood flow, calculated from the mean red cell velocity and vessel diameters was increased significantly during infusion. In contrast, mean wall shear rates in the arterioles and venules were not changed by SNP infusion. The results indicated that SNP and SIN-1 possessed potent antithrombotic activities, whilst SNP increased cerebral blood flow without changing wall shear rate. The findings suggest that the NO released by SNP and SIN-1 may be beneficial for the treatment and protection of cerebral infarction.


Asunto(s)
Embolia y Trombosis Intracraneal/fisiopatología , Óxido Nítrico/metabolismo , Animales , Circulación Cerebrovascular/efectos de los fármacos , Fibrinolíticos/farmacología , Embolia y Trombosis Intracraneal/metabolismo , Microcirculación/efectos de los fármacos , Molsidomina/análogos & derivados , Molsidomina/farmacología , Nitroprusiato/farmacología , Ratas , Ratas Wistar
14.
Thromb Haemost ; 75(3): 503-9, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8701416

RESUMEN

Pentamidine was previously shown to act on glycoprotein (GP) IIb/IIIa (Cox et al., Thromb Haemost 1992; 68: 731). In this paper we study the effect of pentamidine on other RGD-dependent receptors. In a cell adhesion assay, pentamidine was 500 times more potent than RGDS at inhibiting platelet adhesion to fibrinogen. While RGDS inhibited platelet adhesion to fibronectin, endothelial cell adhesion to vitronectin or fibronectin, 293 cell adhesion to vitronectin, IMR 32 cell adhesion to fibronectin and C32 cell adhesion to vitronectin; pentamidine failed to inhibit these interactions at doses as high as 1 mM. Resting platelets fixed in the presence of 1 mM RGDS had increased binding of fibrinogen, i.e., RGDS activated GPIIb/IIIa, while pentamidine at 100 microM had no effect. Similarly, RGDS induced the binding of an anti-LIBS monoclonal antibody, while pentamidine had no effect. Pentamidine partially, but significantly, inhibited lysosome and alpha-granule release induced by the thrombin agonist peptide, while RGDS had no effect. Neither pentamidine nor RGDS affected ADP-induced Ca2+ influx. Pentamidine had no effect on ADP-induced intracellular pH changes while RGDS prevented the pH from returning to normal. Thus, pentamidine is a non-peptide GPIIb/IIIa antagonist that is non-activating and is specific for GPIIb/IIIa.


Asunto(s)
Antiprotozoarios/farmacología , Pentamidina/farmacología , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/antagonistas & inhibidores , Secuencia de Aminoácidos , Línea Celular , Células Cultivadas , Endotelio Vascular/efectos de los fármacos , Epítopos/efectos de los fármacos , Fibrinógeno/química , Humanos , Concentración de Iones de Hidrógeno , Datos de Secuencia Molecular , Oligopéptidos/farmacología , Adhesividad Plaquetaria/efectos de los fármacos
15.
Thromb Haemost ; 68(6): 731-6, 1992 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-1337631

RESUMEN

In this paper we show that the non-peptide anti-parasite agent pentamidine is a broad spectrum anti-platelet agent with an IC50 of 1.1 microM in ADP-induced platelet aggregation in human platelet rich plasma (PRP). It had similar activity when collagen, arachidonic acid, platelet activating factor, thrombin and epinephrine were used. It had no effect on platelet intracellular cAMP levels. It inhibited 125I-fibrinogen, 125I-fibronectin and 125I-von Willebrand factor binding to ADP-activated fixed platelets with IC50 values of 160, 160 and 60 nM respectively. Pentamidine showed a high degree of species selectivity with slightly less activity in monkey and dog PRP and little activity in guinea pig, rabbit, rat and mouse PRP compared with human. This was similar to the other RGD analogues tested. This species specificity was shown to be dependent on the species of platelets and independent of the species of fibrinogen. Thus, pentamidine is a potent non-peptide inhibitor of fibrinogen binding to GPIIb/IIIa.


Asunto(s)
Pentamidina/farmacología , Inhibidores de Agregación Plaquetaria/farmacología , Glicoproteínas de Membrana Plaquetaria/antagonistas & inhibidores , Secuencia de Aminoácidos , Animales , AMP Cíclico/sangre , Fibrinógeno/metabolismo , Cobayas , Humanos , Técnicas In Vitro , Macaca fascicularis , Ratones , Ratones Endogámicos ICR , Datos de Secuencia Molecular , Estructura Molecular , Pentamidina/química , Inhibidores de Agregación Plaquetaria/química , Unión Proteica , Conejos , Ratas , Ratas Sprague-Dawley , Especificidad de la Especie
16.
Thromb Haemost ; 79(6): 1184-90, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9657446

RESUMEN

This study investigated the difference of [Ca2+]i movement in platelets in response to thrombin and TRAP. The involvement of alpha(IIb)beta3 in this signaling was also studied. Stimulation of platelets with thrombin at 0.03 U/ml caused platelet aggregation and a two-peak increase in [Ca2+]i. The second peak of [Ca2+]i, but not the first peak was abolished by the inhibition of platelet aggregation with alpha(IIb)beta3 antagonists or by scavenging endogenous ADP with apyrase. A cyclooxygenase inhibitor, aspirin, and a TXA2 receptor antagonist, BM 13505, also abolished the second peak of [Ca2+]i but not the first peak, although these regents did not inhibit aggregation. Under the same assay conditions, measurement of TXB2 demonstrated that alpha(IIb)beta3 antagonists and aspirin almost completely inhibited the production of TXB2. In contrast to thrombin-stimulation, TRAP caused only a single peak of [Ca2+]i even in the presence of platelet aggregation, and a high level of [Ca2+]i increase was needed for the induction of platelet aggregation. The inhibition of aggregation with alpha(IIb)beta3 antagonists had no effect on [Ca2+]i change and TXB2 production induced by TRAP. Inhibition studies using anti-GPIb antibodies suggested that GPIb may be involved in the thrombin response, but not in the TRAP. Our findings suggest that low dose thrombin causes a different [Ca2+]i response and TXA2 producing signal from TRAP. Endogenous ADP release and fibrinogen binding to alpha(IIb)beta3 are responsible for the synthesis of TXA2 which results in the induction of the second peak of [Ca2+]i in low thrombin- but not TRAP-stimulated platelets.


Asunto(s)
Plaquetas/metabolismo , Calcio/metabolismo , Fragmentos de Péptidos/farmacología , Agregación Plaquetaria/efectos de los fármacos , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/fisiología , Transducción de Señal/efectos de los fármacos , Trombina/farmacología , Tromboxano A2/biosíntesis , Adenosina Difosfato/antagonistas & inhibidores , Adenosina Difosfato/metabolismo , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/farmacología , Apirasa/farmacología , Aspirina/farmacología , Plaquetas/efectos de los fármacos , Inhibidores de la Ciclooxigenasa/farmacología , Dipéptidos/farmacología , Fibrinógeno/metabolismo , Humanos , Transporte Iónico , Fenilacetatos/farmacología , Activación Plaquetaria/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/farmacología , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/antagonistas & inhibidores , Complejo GPIb-IX de Glicoproteína Plaquetaria/antagonistas & inhibidores , Receptores de Trombina/efectos de los fármacos , Receptores de Trombina/metabolismo , Sulfonamidas/farmacología , Tromboxano B2/análisis , Tirofibán , Tirosina/análogos & derivados , Tirosina/farmacología
17.
Br J Pharmacol ; 134(5): 995-1002, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11682447

RESUMEN

1. The effect of the immunosuppressant drug, cyclosporin A (CsA), on the nitric oxide (NO)-cyclic GMP pathway was examined in spontaneous hypertensive rats (SHR). 2. CsA (50 mg kg(-1)) treatment for 14 days induced typical CsA nephrotoxicity, which was characterized by morphological changes in the glomerulus and proximal tubule as well as an abnormality of creatinine clearance, FENa and BUN. 3. CsA significantly decreased both NOS activity in the kidney and NOx contents in urine, but significantly increased cyclic GMP content in the kidney. 4. A marked change in two kinds of enzyme, which contribute towards the increase in cyclic GMP in tissue, namely, a decrease in cyclic GMP-phosphodiesterase activity and increase in guanylate cyclase activity, was observed in the kidney treated with CsA. 5. In the isolated perfused kidney, a decreased in perfusion pressure induced by SNP in the kidney isolated from CsA group was significantly greater than that of control. 6. There seem to exist a reciprocal mechanism to maintain cyclic GMP content via both a decrease in cyclic GMP degradation and an increase in synthesis of cyclic GMP in the kidney treated with CsA. This mechanism is likely to be playing an important role to regulate the homeostasis in the kidney with CsA nephrotoxicity.


Asunto(s)
3',5'-GMP Cíclico Fosfodiesterasas/metabolismo , GMP Cíclico/metabolismo , Ciclosporina/farmacología , Guanilato Ciclasa/metabolismo , Hipertensión/metabolismo , Enfermedades Renales/metabolismo , Animales , Peso Corporal/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Hipertensión/fisiopatología , Inmunosupresores/farmacología , Técnicas In Vitro , Riñón/efectos de los fármacos , Riñón/metabolismo , Riñón/patología , Enfermedades Renales/inducido químicamente , Enfermedades Renales/fisiopatología , Masculino , Nitratos/orina , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa/efectos de los fármacos , Óxido Nítrico Sintasa/metabolismo , Nitritos/orina , Nitroprusiato/farmacología , Perfusión , Presión , Ratas , Ratas Endogámicas SHR , Vasodilatadores/farmacología
18.
J Biochem ; 111(2): 259-64, 1992 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1373719

RESUMEN

Three epitope peptides of hen egg-white lysozyme (HEL) were tested for ability to induce antibodies reactive with native HEL. Each peptide was coupled to bovine gamma-globulin (B gamma G) and 4 rabbits were immunized with each peptide-B gamma G conjugate in complete Freund's adjuvant. The mean association constants (K0s) of HEL-reactive antibodies (HEL-R-Abs) from each immunizing group to [3H]acetyl HEL or to [3H]acetyl-peptide were measured in solution by a double antibody method. Only peptide loop I.II (sequences 57-107 containing Cys64-Cys80 and Cys76-Cys94) induced high-affinity antibodies to HEL (K0 = 2.5 x 10(6)-2.3 x 10(7) M-1) among the three epitope peptides tested. The association constants of antipeptide loop I.II to [3H]acetyl peptide loop I.II were always one to two orders of magnitude higher than those to HEL. In addition, 50 to 80% of the anti-peptide loop I.II antibodies were reactive with native HEL. The specificity of anti-peptide loop I.II was directed to a conformational feature of the peptide rather than to native HEL and reactivity of the antibody to HEL was interpreted as a kind of cross-reaction. The HEL-R-Abs from anti-Ploop I.II antisera also manifested neutralizing activities against the enzymic activity of HEL when Micrococcus luteus was used as the substrate.


Asunto(s)
Anticuerpos/análisis , Proteínas del Huevo/inmunología , Epítopos/inmunología , Muramidasa/inmunología , Animales , Anticuerpos/inmunología , Inmunización , Péptidos/inmunología , Conejos , Tritio
19.
J Biochem ; 113(3): 314-20, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7683642

RESUMEN

The specificity of hen egg-white lysozyme (HEL)-reactive rabbit antibodies induced by the peptide loop I.II (sequences 57-107 containing Cys64-Cys80 and Cys76-Cys94) of HEL was clarified by analyzing their cross-reactions with various avian lysozymes and their reaction with synthetic peptides (sequences 59-82) in which alanine was substituted for the amino acid at certain positions. The Arg-68 residue of HEL plays a dominant role in the binding, while Gly-71, Ser-72, Arg-73, and Pro-79 also contribute to the binding of two anti-Ploop I.II antibodies (rabbit number 125 and 126). These residues, although remote in sequence, are grouped together in the crystal structure of HEL and may form an area of contact with the antibody. Contributions by Trp-63, Ile-78, and Asn-77 to the binding of the two antibodies to HEL were excluded. These results support the idea that the anti-Ploop I.II antibodies recognize a conformational type of epitope which is similar to that of native HEL. The immunogenicity of the reduced and alkylated form of Ploop I.II was also tested, but it failed to induce an HEL-reactive antibody.


Asunto(s)
Epítopos/inmunología , Muramidasa/inmunología , Fragmentos de Péptidos/inmunología , Alanina/química , Secuencia de Aminoácidos , Animales , Especificidad de Anticuerpos , Pollos , Cromatografía Líquida de Alta Presión , Reacciones Cruzadas , Epítopos/química , Datos de Secuencia Molecular , Muramidasa/química , Fragmentos de Péptidos/química , Péptidos/inmunología
20.
Metabolism ; 49(11): 1395-9, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11092500

RESUMEN

We studied the effects of zenarestat, an aldose reductase inhibitor (ARI), on peripheral neuropathy in Zucker diabetic fatty (ZDF) rats, an animal model of type 2 diabetes. ZDF rats and their lean rats counterparts were fed a sucrose-containing diet, and zenarestat was given orally once a day for 8 weeks. Motor nerve conduction velocity (MNCV), F-wave minimal latency (FML), and sorbitol concentrations in the sciatic nerve were measured. In ZDF control rats, a remarkable accumulation of sorbitol, a delay in FML, and a slowing of MNCV were observed compared with lean rats. At a dose of 3.2 mg/kg, zenarestat had no significant effect on the delay in FML and the slowing of MNCV, although the sorbitol accumulation in the sciatic nerve was partially inhibited in ZDF rats. On the other hand, 32 mg/kg zenarestat treatment improved these nerve dysfunctions in ZDF rats, along with a reduction of nerve sorbitol accumulation almost to the level of lean rats. These data showed that zenarestat improved diabetic peripheral neuropathy in ZDF rats, a type 2 diabetes model, providing evidence for the therapeutic potential of zenarestat for the treatment of diabetic neuropathy.


Asunto(s)
Aldehído Reductasa/antagonistas & inhibidores , Neuropatías Diabéticas/tratamiento farmacológico , Inhibidores Enzimáticos/uso terapéutico , Quinazolinas/uso terapéutico , Animales , Glucemia/análisis , Peso Corporal , Diabetes Mellitus Tipo 2/complicaciones , Neuropatías Diabéticas/complicaciones , Neuropatías Diabéticas/fisiopatología , Modelos Animales de Enfermedad , Inhibidores Enzimáticos/farmacología , Masculino , Quinazolinas/farmacología , Ratas , Ratas Zucker
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