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1.
Br J Cancer ; 84(11): 1564-70, 2001 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-11384109

RESUMEN

Dendritic cells (DCs) loaded with tumour antigens have been successfully used to induce protective tumour immunity in murine models and human trials. However, it is still unclear which DC administration route elicits a superior therapeutic effect. Herein, we investigated the vaccine efficiency of DC2.4 cells, a murine dendritic cell line, pulsed with ovalbumin (OVA) in the murine E.G7-OVA tumour model after immunization via various routes. After a single vaccination using 1 x 10(6)OVA-pulsed DC2.4 cells, tumour was completely rejected in the intradermally (i.d.; three of four mice), subcutaneously (s.c.; three of four mice), and intraperitoneally (i.p.; one of four mice) immunized groups. Double vaccinations enhanced the anti-tumour effect in all groups except the intravenous (i.v.) group, which failed to achieve complete rejection. The anti-tumour efficacy of each immunization route was correlated with the OVA-specific cytotoxic T lymphocyte (CTL) activity evaluated on day 7 post-vaccination. Furthermore, the accumulation of DC2.4 cells in the regional lymph nodes was detected only in the i.d.-and s.c.-injected groups. These results demonstrate that the administration route of antigen-loaded DCs affects the migration of DCs to lymphoid tissues and the magnitude of antigen-specific CTL response. Furthermore, the immunization route affects vaccine efficiency.


Asunto(s)
Antígenos de Neoplasias/inmunología , Vacunas contra el Cáncer/administración & dosificación , Células Dendríticas , Animales , Modelos Animales de Enfermedad , Femenino , Infusiones Parenterales , Inyecciones Intradérmicas , Inyecciones Subcutáneas , Ratones , Ratones Endogámicos C57BL , Ovalbúmina/administración & dosificación , Linfocitos T Citotóxicos/inmunología
2.
Nihon Rinsho ; 58 Suppl 1: 376-9, 2000 Jan.
Artículo en Japonés | MEDLINE | ID: mdl-11026294
3.
Endocr J ; 46(1): 133-7, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10426577

RESUMEN

We encountered a 58-year-old woman with acromegaly accompanied by a cortisol-secreting adrenal tumor without clinical features of hypercortisolism. The simultaneous occurrence of these two endocrinopathies in one individual is extremely rare. She was diagnosed as having diabetes mellitus 8 years ago. Afterwards, in spite of insulin therapy, her hyperglycemia could not be well controlled. Her acromegaly and preclinical Cushing's syndrome were histopathologically proven to be due to a pituitary adenoma and an adrenocortical adenoma, respectively. Successful treatment for these endocrinopathies resulted in greatly improved blood sugar control because of a reduction in insulin resistance. In this case of preclinical Cushing's syndrome, replacement therapy with glucocorticoid was able to be discontinued at only 8 weeks after adrenalectomy, so that the period of necessary replacement was much shorter than that for overt Cushing's syndrome. This is the first report describing insulin resistance before and after treatment in a case of acromegaly accompanied by adrenal preclinical Cushing's syndrome.


Asunto(s)
Acromegalia/diagnóstico , Adenoma/diagnóstico , Neoplasias de la Corteza Suprarrenal/diagnóstico , Síndrome de Cushing/diagnóstico , Acromegalia/complicaciones , Adenoma/complicaciones , Adenoma/cirugía , Neoplasias de la Corteza Suprarrenal/complicaciones , Neoplasias de la Corteza Suprarrenal/cirugía , Glucemia/metabolismo , Síndrome de Cushing/complicaciones , Síndrome de Cushing/cirugía , Complicaciones de la Diabetes , Diabetes Mellitus/sangre , Diabetes Mellitus/tratamiento farmacológico , Femenino , Técnica de Clampeo de la Glucosa , Humanos , Hidrocortisona/metabolismo , Resistencia a la Insulina , Imagen por Resonancia Magnética , Persona de Mediana Edad , Neoplasias Hipofisarias/complicaciones , Neoplasias Hipofisarias/diagnóstico , Neoplasias Hipofisarias/cirugía , Tomografía Computarizada por Rayos X
5.
Jpn J Antibiot ; 51(7): 488-93, 1998 Jul.
Artículo en Japonés | MEDLINE | ID: mdl-9755432

RESUMEN

The synergistic relationship between vancomycin (VCM) and carbapenem (CRB) has been reported in antibacterial activity against CRB-resistant strains of MRSA. The purpose of this study is to investigate the antibacterial activity against CRB-resistant MRSA using VCM, panipenem (PAPM), and a combination of both. 8 strains of CRB-resistant MRSA were used to examine the effects of these antibiotics by the broth microdiluton technique. The effect of pH (pH 6, 7, 8) on MIC of VCM alone was not observed in 7 out of 8 strains; MICs were between 1.0-2.0 micrograms/ml. PAPM alone, however, showed an enhancing tendency in alkaline condition in 6 out of 8 strains. There was no influence of pH on MICs in the combination use of VCM and PAPM, showing additive effect in 1 strain and synergistic in 6 strains. Killing-curves against PAPM-resistant MRSA were examined under the following drug combinations; 1/4 MIC of VCM (0.5 micrograms/ml) plus 1/4 MIC of PAPM (16 micrograms/ml), and 1/4 MIC of VCM plus 1/8 MIC of PAPM (8 micrograms/ml). The former drug combination showed synersistic effect; decrease from 1.05 x 10(5) to 6.45 x 10(4) CFU/ml after 6 hours' incubation and to less than 10 CFU/ml after 24 hours. The latter drug combination showed synergistic activity (2.68 x 10(2) CFU/ml) after 24 hours' incubation, but lost antibacterial activity after 48 hours. In conclusion, PAPM in combination with VCM showed synergistic effects on CRB-resistant MRSA. This combination therapy should be evaluated for the treatment of MRSA infection in patients with renal dysfunction.


Asunto(s)
Quimioterapia Combinada/farmacología , Staphylococcus aureus/efectos de los fármacos , Tienamicinas/farmacología , Vancomicina/farmacología , Carbapenémicos/farmacología , Farmacorresistencia Microbiana , Sinergismo Farmacológico , Concentración de Iones de Hidrógeno , Resistencia a la Meticilina
6.
Arerugi ; 46(10): 1013-24, 1997 Oct.
Artículo en Japonés | MEDLINE | ID: mdl-9404089

RESUMEN

By a randomized double blind control trial we studied the effect of vacuum cleaning of room floors, mattresses and quilts for twelve months on clinical symptoms and laboratory data of atopic dermatitis patients. All patients used the identical new vacuum cleaners. Thirty patients (3-12 years of age) with relatively stable skin conditions were randomly allocated to either of the following two groups. In the monitor group we visited patient's home every three weeks and mite specialists cleaned drastically the room floors, mattresses and quilts and the patient continued to clean in the same way in-between. In the control group we visited similarly but the cleaning was made insufficiently which was also followed by the patient. But, at 2 occasions (the first and the last visits), cleaning was made drastically also in the control group. Thus the mite numbers were counted precisely at the start and the end of the experiment both in the monitor and control groups. Each patient was seen every six weeks by the same doctor and estimated of his symptoms using our unique scoring system (Fig. 1). At the start and the end of the study, total IgE and specific IgE antibodies to house dust mites in the serum were evaluated. The monitor group showed a tendency to count smaller number of mites than the control group after a year, when there was a significant difference only in quilts. However, a statistically significant decrease in the mite counts was observed only in room floors and not in mattresses and quilts both in the monitor and control groups (Fig. 2). Clinical scores after a year significantly improved only in the monitor group and not in the control group (Fig. 3). Serum IgE value and specific antibody titer to house dust mites were not changed significantly after the trial in both groups. As a conclusion, vacuum cleaning of the patient's room improved the clinical symptoms of atopic dermatitis but this could not be related to the reduction of house dust mite number.


Asunto(s)
Dermatitis Atópica/inmunología , Vivienda , Inmunoglobulina E/sangre , Ácaros/inmunología , Animales , Ropa de Cama y Ropa Blanca , Niño , Preescolar , Método Doble Ciego , Polvo , Femenino , Pisos y Cubiertas de Piso , Humanos , Masculino , Prueba de Radioalergoadsorción
7.
J Mol Cell Cardiol ; 29(8): 2125-30, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9281444

RESUMEN

To determine whether adrenomedullin (AM), a novel 51-residue vasodilator peptide originally isolated from human pheochromocytoma, is expressed by the heart, and whether the expression of cardiac AM gene is regulated by glucocorticoids, the effect of dexamethasone (DEX) on the expression of protein and mRNA of AM and atrial natriuretic peptide (ANP) was tested in cultured ventricular myocytes prepared from the neonatal rats. Northern blot analysis of rat ventricular myocytes with cDNAs for rat AM and ANP as probes revealed distinct bands corresponding to the sizes of rat AM mRNA (1. 6 kb) and rat ANP mRNA (1 kb), respectively. Dexamethasone increased steady-state levels of both AM and ANP mRNA as well as secretion of both AM and ANP immunoreactivity in a time- and dose-dependent manner. The stimulatory effects of dexamethasone were completely abolished by a glucocorticoid antagonist (RU38486) and a RNA synthesis inhibitor (actinomycin D). The approximate half-lives of basal and dexamethasone-induced AM mRNA were about 4 h, suggesting that dexamethasone-induced up-regulation of AM mRNA was unlikely due to its decreased degradation. These data suggest that glucocorticoids directly stimulate gene expression of AM as well as ANP in rat ventricular myocytes.


Asunto(s)
Factor Natriurético Atrial/biosíntesis , Dexametasona/farmacología , Corazón/efectos de los fármacos , Miocardio/citología , Péptidos/síntesis química , Regulación hacia Arriba/efectos de los fármacos , Adrenomedulina , Animales , Animales Recién Nacidos , Factor Natriurético Atrial/genética , Células Cultivadas , Dactinomicina/farmacología , Ventrículos Cardíacos/citología , Ventrículos Cardíacos/efectos de los fármacos , Antagonistas de Hormonas/farmacología , Mifepristona/farmacología , Miocardio/metabolismo , Inhibidores de la Síntesis del Ácido Nucleico/farmacología , Péptidos/genética , ARN Mensajero/biosíntesis , Ratas
8.
Jpn J Antibiot ; 50(8): 711-6, 1997 Aug.
Artículo en Japonés | MEDLINE | ID: mdl-9339397

RESUMEN

We determined in vitro combined effects of vancomycin (VCM) plus carbapenems (CRBs) on 12 methicillin-resistant Staphylococcus aureus (MRSA) which are resistant to CRBs. Combinations of VCM plus imipenem (IPM) and VCM plus panipenem (PAPM) and VCM plus meropenem (MEPM) indicated synergistic effects, fractional inhibitory concentration (FIC) indices of < or = 0.05, against 67%, 75%, 67% of the strains, respectively. Against forty two percent of strains tested, 1 MIC of VCM was equal to 1 MBC, and similarly, IPM, PAPM and MEPM had 1 MIC = 1 MBC against 42%, 67% and 75% of the strains tested, respectively. Combinations of VCM plus IPM and VCM plus PAPM and VCM plus MEPM showed synergistic effects, hence a fractional bactericidal concentration (FBC) index of < or = 0.50, against 42%, 50%, 75% of the strains, respectively, and the combination of VCM plus MEPM was most synergistic. These results suggest that combination therapy of VCM with CRB is useful for the treatment of MRSA infection in patients with renal dysfunction.


Asunto(s)
Antibacterianos/administración & dosificación , Carbapenémicos/administración & dosificación , Carbapenémicos/farmacología , Resistencia a la Meticilina , Staphylococcus aureus/efectos de los fármacos , Tienamicinas/administración & dosificación , Vancomicina/administración & dosificación , Imipenem/administración & dosificación , Meropenem
10.
Kansenshogaku Zasshi ; 70(4): 325-30, 1996 Apr.
Artículo en Japonés | MEDLINE | ID: mdl-8690946

RESUMEN

Patients with diabetes mellitus (DM) often suffer from various and severe infection. Patients with pancreatic DM have malnutrition due to chronic pancreatitis. Therefore it is believed that patients with pancreatic DM have a lower ability of host defence to infectious diseases than normal subjects. We examined the primpheral lymphocyte subsets (T cell, B cell, NK cell, CD3+ 56+ T) of eighteen patients (males, age = 52.8 +/- 12.7 years old, mean +/- SD) with pancreatic DM by two color flow-cytometry to evaluate the lymphocyte function. Ratios of T cell (T%, 66.9 +/- 9.3%, mean +/- SD). B cell (B%, 13.1 +/- 5.8%) and NK cell (Nk%, 19.3 +/- 8.7%) to total peripheral lymphocytes of patients with pancreatic DM were not significantly different from those (T% = 66.4 +/- 7.8%, B% = 13.5 +/- 6.7%, NK% = 19.9 +/- 9.1%) of thirteen normal subjects (males, age = 51.2 +/- 13.1). CD3+56+ T cell % (4.1 +/- 1.9%) of patients with pancreatic DM was lower than that (6.0 +/- 3.0%) of normal subjects (p < 0.05). CD3+56+ T cells have cytotoxic activity and it is likely that this activity is similar to that of NK cells. These results suggested that a decrease in peripheral CD3+56+ T cell % is a factor showing a weak host defense mechanism to infectious diseases in patients with pancreatic DM.


Asunto(s)
Diabetes Mellitus/inmunología , Subgrupos de Linfocitos T/inmunología , Adulto , Antígenos CD34/inmunología , Antígeno CD56/inmunología , Humanos , Inmunidad Innata , Células Asesinas Naturales/inmunología , Persona de Mediana Edad
11.
Clin Ther ; 17(3): 448-59, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-7585849

RESUMEN

Gastric and upper small intestine pH levels were measured continuously over 24 hours in patients with chronic pancreatitis, and values obtained before and after the administration of omeprazole were compared. Additionally, omeprazole was administered for 2 weeks and the fecal excretion of fat was compared before and after drug therapy. Postprandial gastric pH levels, initially 2.9 to 3.2, increased by 1.6 to 2.1 after treatment. Postprandial upper small intestine pH levels, initially 5.1 to 5.5, increased by 0.7 to 1.0. The lowest pH value of the upper small intestine was 2.2 to 2.4 postprandially; this was increased by > 1.0 after omeprazole, and the amplitude of pH variation was reduced. The cumulative proportions of intraintestinal pH strata of < or = 3, < or = 4, or < or = 5, and higher, initially being 16.4% to 17.1%, 27.4% to 31.7%, and 52.6% to 57.8%, respectively, were remarkably improved after drug treatment. Gastric pH and upper small intestine pH levels showed a positive correlation; an increase in gastric pH levels by 2 corresponded to an increase in small intestine pH levels by 1. After omeprazole administration, mean fecal excretion of fat was decreased to 4.1 +/- 2.6 g/d (range, 1.1 to 9.8 g/d) from 6.5 +/- 3.9 g/d (range, 1.6 to 13.5 g/d). Decreases in excretion of fat averaged 3.4 g/d (range, 2.2 to 4.5 g/d) in patients with steatorrhea. It was concluded that steatorrhea due to chronic pancreatitis can be improved to some extent by improving upper small intestine pH levels following the elevation of gastric pH levels after administration of omeprazole.


Asunto(s)
Antiulcerosos/farmacología , Ácido Gástrico/metabolismo , Intestino Delgado/metabolismo , Omeprazol/farmacología , Pancreatitis/metabolismo , Adulto , Enfermedad Crónica , Grasas de la Dieta/farmacología , Heces/química , Interacciones Alimento-Droga , Humanos , Concentración de Iones de Hidrógeno , Intestino Delgado/efectos de los fármacos , Metabolismo de los Lípidos , Persona de Mediana Edad , Pancreatitis/sangre , Pancreatitis/complicaciones , Inhibidores de la Bomba de Protones
13.
Life Sci ; 56(25): PL449-54, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-7791506

RESUMEN

To elucidate the role of endothelin receptor subtypes in the abnormal proliferation of vascular smooth muscle cells (VSMC) associated with vascular injury, we have investigated the effects of a novel and potent nonselective ETA/ETB receptor antagonist (TAK-044) on the proliferation of rat VSMC in vitro and in vivo. TAK-044 dose-dependently inhibited DNA synthesis stimulated by 10(-7) M ET-1 in cultured rat VSMC from the late passage with the approximate IC50 of 6 x 10(-8) M. After balloon angioplasty, the neointimal lesion in the injured carotid arteries in the TAK-044-treated group (0.052 +/- 0.014 mm2) was significantly (p < 0.05) decreased compared to that in control group (0.26 +/- 0.045 mm2), while the medial surface area was not affected. The intima/media ratio in the TAK-044 group (31 +/- 6%) also significantly (p < 0.05) decreased from that of the control group (148 +/- 25%). Our data suggest that nonselective ETA/ETB receptor antagonists may be therapeutic potential for prevention against the intimal thickening associated with vascular injury.


Asunto(s)
Angioplastia de Balón , Antagonistas de los Receptores de Endotelina , Músculo Liso Vascular/efectos de los fármacos , Péptidos Cíclicos/farmacología , Animales , Unión Competitiva , División Celular/efectos de los fármacos , Células Cultivadas , Endotelinas/metabolismo , Radioisótopos de Yodo , Masculino , Músculo Liso Vascular/citología , Ratas , Ratas Wistar
14.
Am J Physiol ; 267(2 Pt 2): F325-30, 1994 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8067393

RESUMEN

We investigated kallikrein-binding protein (KBP) mRNA distribution in the kidney of Sprague-Dawley (SD) rats, spontaneously hypertensive rats (SHR), and Wistar-Kyoto strain (WKY) rats. Northern blot analysis revealed that KBP mRNA was located mainly in the medulla and with lower amounts in SHR than in WKY rats. KBP mRNA in microdissected nephron segments was detected by reverse transcription and polymerase chain reaction (RT-PCR) followed by Southern blot analysis. In SD rats, the most abundant signals were consistently found in inner medullary collecting duct (IMCD), with small amounts in outer medullary collecting duct, proximal convoluted tubule, and glomerulus. No signals were found in connecting tubule and cortical collecting duct. The nephron distribution of KBP mRNA was similar in WKY and SD rats. Only a small amount of signal was found, however, in IMCD of SHR. In conclusion, 1) KBP mRNA was predominantly distributed in the medullary segments of the distal nephron, downstream from the known kallikrein activity site in the collecting duct, and 2) KBP mRNA expression was significantly decreased in the kidney of SHR.


Asunto(s)
Proteínas Portadoras/genética , Riñón/metabolismo , ARN Mensajero/metabolismo , Ratas Endogámicas SHR/genética , Ratas Endogámicas WKY/genética , Serpinas/genética , Animales , Secuencia de Bases , Calicreínas/metabolismo , Masculino , Sondas Moleculares/genética , Datos de Secuencia Molecular , Nefronas/metabolismo , Reacción en Cadena de la Polimerasa , Ratas , Ratas Sprague-Dawley/genética , Distribución Tisular
15.
Circulation ; 90(1): 375-83, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7517798

RESUMEN

BACKGROUND: Impaired myocardial contractility in septic shock is protracting, which may be caused by cytokine-induced nitric oxide (NO) synthesis in the heart. However, the cellular mechanism by which cytokines induce nitric oxide synthase (NOS) in cardiocytes remains obscure. METHODS AND RESULTS: We studied the effect of human recombinant interleukin-1 beta (IL-1 beta) on synthesis of NO2-/NO3- (NOx) and the expression of NOS mRNA and protein in cultured neonatal rat cardiocytes. IL-1 beta dose-dependently (0.1 to 10 ng/mL) stimulated NOx production as a function of time (6 to 48 hours). Northern blot analysis using complementary DNAs for rat brain-type constitutive (c) NOS and mouse macrophage-type inducible (i) NOS as probes showed that IL-1 beta induced expression of mRNA for iNOS but not for cNOS, starting after 6 hours and reaching a maximum after 48 hours in cardiocytes. IL-1 beta similarly induced iNOS mRNA expression in cultured adult rat cardiocytes in a time-dependent manner. Western blot analysis using specific antibody against the N-terminal fragment of mouse iNOS revealed the expression of 130-kD iNOS-like protein in IL-1 beta-treated cardiocytes. Northern blotting and immunocytochemical study revealed that IL-1 beta-induced iNOS mRNA and iNOS-like immunoreactivity were exclusively localized to cardiac myocytes but also to nonmyocytes, to a lesser extent. NG-mono-methyl-L-arginine, an NOS inhibitor, completely blocked the IL-1 beta-induced NOx production, whose effect was reversed by L-arginine but not by D-arginine. Dexamethasone inhibited the IL-1 beta-induced NOx production as well as iNOS mRNA expression. Cycloheximide and actinomycin D completely inhibited the IL-1 beta-induced NOx production and iNOS mRNA expression. Neither a calmodulin inhibitor (W-7), a protein kinase C inhibitor (calphostin C), nor a Ca2+ channel antagonist (nicardipine) showed any effect on the IL-1 beta-induced NOx production. CONCLUSIONS: These data demonstrate that IL-1 beta induces macrophage-type iNOS mRNA expression mainly by cardiac myocytes but also by nonmyocytes to a lesser extent, and subsequent de novo protein synthesis of iNOS leads to excessive local production of NO by cardiocytes.


Asunto(s)
Aminoácido Oxidorreductasas/genética , Regulación de la Expresión Génica , Interleucina-1/farmacología , Miocardio/enzimología , Animales , Secuencia de Bases , Células Cultivadas , Relación Dosis-Respuesta a Droga , Humanos , Masculino , Ratones , Datos de Secuencia Molecular , Miocardio/citología , Óxido Nítrico/biosíntesis , Óxido Nítrico Sintasa , Sondas de Oligonucleótidos/genética , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Proteínas Recombinantes
16.
Biochem Biophys Res Commun ; 194(3): 1282-7, 1993 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-8352786

RESUMEN

The effect of angiotensin (ANG) II on the expression of endothelin (ET) receptor subtype (ETA, ETB) mRNA in cultured neonatal rat cardiomyocytes was studied. ANG II (10(-7) M) increased steady-state mRNA levels of ETB receptor, but not ETA receptor, during 6-12 hr incubation, whose effect was dose-dependent (10(-9)-10(-7) M). ANG II receptor type-1 (AT1) antagonist (CV-11974) completely inhibited the ANG II-induced up-regulation of ETB receptor, whereas the inhibitory effect by ANG II receptor type-2 (AT2) antagonist (PD 123319) was incomplete. These results suggest that ANG II up-regulates cardiac ETB receptor, predominantly via AT1 receptor.


Asunto(s)
Angiotensina II/farmacología , Miocardio/metabolismo , ARN Mensajero/biosíntesis , Receptores de Endotelina/biosíntesis , Regulación hacia Arriba , Animales , Animales Recién Nacidos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Variación Genética , Miocardio/citología , Ratas , Ratas Wistar
17.
J Clin Invest ; 92(1): 398-403, 1993 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8326007

RESUMEN

To elucidate the cellular mechanism by which angiotensin II (ANG II) induces cardiac hypertrophy, we investigated the possible autocrine/paracrine role of endogenous endothelin-1 (ET-1) in ANG II-induced hypertrophy of neonatal rat cardiomyocytes by use of synthetic ET-1 receptor antagonist and antisense oligonucleotides to preproET-1 (ppET-1) mRNA. Northern blot analysis and in situ hybridization revealed that ppET-1 mRNA was expressed in cardiomyocytes, but, to a lesser extent, in nonmyocytes as well. ANG II upregulated ppET-1 mRNA level by threefold over control level as early as 30 min, and it stimulated release of immunoreactive ET-1 from cardiomyocytes in a dose- and time-dependent manner. ET-1 stimulated ppET-1 mRNA levels after 30 min in a similar fashion as ANG II. Tetradecanoylphorbol-acetate (10(-7) M) mimicked the effects of ANG II and ET-1 on induction of ppET-1 mRNA. ANG II-induced ppET-1 gene expression was completely blocked by protein kinase C inhibitor H-7 or by down-regulation of endogenous protein kinase C by pretreatment with phorbol ester. ET-1 and ANG II stimulated twofold increase [3H]leucine incorporation into cardiomyocytes, whose effects were similarly and dose dependently inhibited by endothelin A receptor antagonist (BQ123). Introduction of antisense sequence against coding region of ppET-1 mRNA into cardiomyocytes resulted in complete blockade with ppET-1 mRNA levels and [3H]leucine incorporation stimulated by ANG II. These results suggest that endogenous ET-1 locally generated and secreted by cardiomyocytes may contribute to ANG II-induced cardiac hypertrophy via an autocrine/paracrine fashion.


Asunto(s)
Angiotensina II/farmacología , Cardiomegalia/etiología , Endotelinas/fisiología , Miocardio/citología , Animales , Secuencia de Bases , Compuestos de Bifenilo/farmacología , Células Cultivadas , Antagonistas de los Receptores de Endotelina , Expresión Génica/efectos de los fármacos , Imidazoles/farmacología , Técnicas In Vitro , Losartán , Datos de Secuencia Molecular , Proteínas Musculares/biosíntesis , Oligodesoxirribonucleótidos/química , Oligonucleótidos Antisentido/farmacología , Péptidos Cíclicos/farmacología , ARN Mensajero/genética , Ratas , Ratas Wistar , Tetrazoles/farmacología
18.
Circulation ; 87(5): 1715-21, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-7683979

RESUMEN

BACKGROUND: Cardiac hypertrophy is commonly observed in acromegalic patients, in whom serum insulin-like growth factor-I (IGF-I) levels are elevated. In the present study, we examined whether IGF-I induces hypertrophy in cultured neonatal rat cardiomyocytes through its specific receptor and whether IGF binding protein-3 (IGFBP-3), which is a major circulating carrier protein for IGF-I, inhibits IGF-I-induced cardiac hypertrophy in vitro. METHODS AND RESULTS: Because the response of cardiac hypertrophy is characterized by the induction of expression for muscle-specific genes, the effect of IGF-I on steady-state levels of mRNA for myosin light chain-2 (MLC-2) and troponin I and for skeletal and cardiac alpha-actin isoforms was evaluated by Northern blot analysis. IGF-I (10(-7) M) increased mRNA levels for MLC-2 and troponin I as early as 60 minutes with maximum levels by 6 hours, which were maintained for as long as 24 hours. IGF-I (10(-7) M) also increased transcripts for skeletal alpha-actin but not for cardiac alpha-actin. The cell size as evaluated morphometrically was almost doubled after 48-hour treatment with IGF-I. IGF-I induction of protein synthesis was dose dependent (10(-10) to 10(-7) M) with a maximal 2.2-fold increase seen at 10(-8) M. In contrast to the hypertrophic effect of IGF-I, growth hormone affected neither protein synthesis nor expression for muscle-specific genes. Binding study using 125I-IGF-I revealed the presence of specific binding sites for IGF-I in rat cardiomyocytes. IGFBP-3 induced a dose-dependent inhibition of protein synthesis stimulated by IGF-I; IGFBP-3 (10(-7) M) completely inhibited the [3H]leucine uptake stimulated by IGF-I (10(-8) M). IGFBP-3 similarly inhibited the IGF-I-stimulated gene expressions for MLC-2 and troponin I. CONCLUSIONS: These results suggest that IGF-I directly causes cardiac hypertrophy and that its effect can be blocked by IGFBP-3.


Asunto(s)
Cardiomegalia/inducido químicamente , Cardiomegalia/genética , Regulación de la Expresión Génica/efectos de los fármacos , Factor I del Crecimiento Similar a la Insulina/farmacología , Músculos/efectos de los fármacos , Actinas/genética , Animales , Unión Competitiva , Proteínas Portadoras/farmacología , Células Cultivadas , Proteínas de Unión a Factor de Crecimiento Similar a la Insulina , Factor I del Crecimiento Similar a la Insulina/metabolismo , Isomerismo , Leucina/farmacocinética , Músculos/citología , Músculos/fisiología , Miocardio/metabolismo , Miocardio/patología , Miosinas/genética , ARN Mensajero/metabolismo , Ratas , Troponina/genética , Troponina I
19.
Circ Res ; 71(5): 1242-53, 1992 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1327578

RESUMEN

Endothelin-1 (ET-1), a 21-amino acid vasoconstrictive peptide, increases intracellular Ca2+ level and has hypertrophic action on ventricular myocytes. To elucidate a possible role of Ca2+ entry through sarcolemmal Ca2+ channels on this ET-1 action, we examined effects of ET-1 on L-type (ICa,L) and T-type (ICa,T) Ca2+ currents in cultured neonatal rat ventricular myocytes using the patch-clamp technique. ET-1 at a concentration of 10 nM increased the maximum current density of ICa,T from -3.0 +/- 1.4 microA/cm2 in the control condition to -4.4 +/- 1.6 microA/cm2 (p < 0.01). Although the peak amplitude of ICa,L was decreased during ET-1 application (from -9.7 +/- 1.9 microA/cm2 in the control condition to -5.0 +/- 1.4 microA/cm2 [p < 0.01]), this magnitude of decrease in ICa,T (52 +/- 19%) was comparable to that of spontaneous "run-down" of ICa,L (47 +/- 26%). The enhancement of ICa,T by ET-1 was dose dependent; it was initiated as low as 0.32 nM, and the maximal response was attained at approximately 10 nM, with a half-maximal dose of 1.26 nM. The enhancement of ICa,T by ET-1 was antagonized by protein kinase C inhibitors staurosporine (0.2 microM) and 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7, 20 microM) applied to the pipette solution. Extracellular application of tumor-promoting phorbol esters, phorbol 12,13-dibutyrate (PDBu) and 4 beta-phorbol 12-myristate 13-acetate, augmented ICa,T. PDBu (0.2 microM) increased the maximal current density of ICa,T from -4.2 +/- 0.5 microA/cm2 in the control condition to -5.5 +/- 1.0 microA/cm2 (p < 0.01). In the presence of H-7 (20 microM) in the pipette solution, PDBu failed to enhance ICa,T, and an inactive isomer of PDBu (4 alpha-phorbol 12,13-dibutyrate, 0.2 microM) did not augment ICa,T. Thus, ET-1 enhances Ca2+ entry through the sarcolemmal T-type Ca2+ channel, possibly through a pathway involving activation of protein kinase C. This ET-1 action may be involved in the rise of the intracellular Ca2+ level and may contribute to the induction of cardiac hypertrophy by ET-1.


Asunto(s)
Canales de Calcio/metabolismo , Calcio/metabolismo , Endotelinas/farmacología , Miocardio/metabolismo , Animales , Animales Recién Nacidos , Canales de Calcio/efectos de los fármacos , Canales de Calcio/fisiología , Células Cultivadas , Electrofisiología , Activación Enzimática , Guanosina Trifosfato/farmacología , Ventrículos Cardíacos , Miocardio/citología , Proteína Quinasa C/metabolismo , Inhibidores de Proteínas Quinasas , Ratas
20.
Eur J Nucl Med ; 19(3): 219-21, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1533369

RESUMEN

We present the case of a 70-year-old woman with acute myocardial infarction who died of cardiac rupture on the 2nd hospital day. Dual isotope single photon emission computed tomography (SPECT) using thallium-201 chloride and technetium-99m pyrophosphate (PYP) performed on the 2nd hospital day showed a large perfusion defect in the anteroseptal wall on 201Tl image and a increased accumulation on 99mTc-PYP image in the anterior area consistent with a partial defect. Autopsy performed 1 h after death revealed a tear in the left ventricular anterior wall consistent with the defect on the 99mTc-PYP image. We propose that the finding of a partial defect in 99mTc-PYP is an interesting finding which may be associated with cardiac rupture following acute myocardial infarction.


Asunto(s)
Rotura Cardíaca Posinfarto/diagnóstico por imagen , Pirofosfato de Tecnecio Tc 99m , Anciano , Femenino , Humanos , Cintigrafía
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