Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Neuroimage ; 147: 726-735, 2017 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-27902936

RESUMEN

Resting-state fMRI studies have become very important in cognitive neuroscience because they are able to identify BOLD fluctuations in brain circuits involved in motor, cognitive, or perceptual processes without the use of an explicit task. Such approaches have been fruitful when applied to various disordered populations, or to children or the elderly. However, insufficient attention has been paid to the consequences of the loud acoustic scanner noise associated with conventional fMRI acquisition, which could be an important confounding factor affecting auditory and/or cognitive networks in resting-state fMRI. Several approaches have been developed to mitigate the effects of acoustic noise on fMRI signals, including sparse sampling protocols and interleaved silent steady state (ISSS) acquisition methods, the latter being used only for task-based fMRI. Here, we developed an ISSS protocol for resting-state fMRI (rs-ISSS) consisting of rapid acquisition of a set of echo planar imaging volumes following each silent period, during which the steady state longitudinal magnetization was maintained with a train of relatively silent slice-selective excitation pulses. We evaluated the test-retest reliability of intensity and spatial extent of connectivity networks of fMRI BOLD signal across three different days for rs-ISSS and compared it with a standard resting-state fMRI (rs-STD). We also compared the strength and distribution of connectivity networks between rs-ISSS and rs-STD. We found that both rs-ISSS and rs-STD showed high reproducibility of fMRI signal across days. In addition, rs-ISSS showed a more robust pattern of functional connectivity within the somatosensory and motor networks, as well as an auditory network compared with rs-STD. An increased connectivity between the default mode network and the language network and with the anterior cingulate cortex (ACC) network was also found for rs-ISSS compared with rs-STD. Finally, region of interest analysis showed higher interhemispheric connectivity in Heschl's gyri in rs-ISSS compared with rs-STD, with lower variability across days. The present findings suggest that rs-ISSS may be advantageous for detecting network connectivity in a less noisy environment, and that resting-state studies carried out with standard scanning protocols should consider the potential effects of loud noise on the measured networks.


Asunto(s)
Percepción Auditiva/fisiología , Mapeo Encefálico/métodos , Corteza Cerebral/fisiología , Imagen por Resonancia Magnética/métodos , Red Nerviosa/fisiología , Adolescente , Adulto , Mapeo Encefálico/normas , Corteza Cerebral/diagnóstico por imagen , Imagen Eco-Planar/métodos , Imagen Eco-Planar/normas , Femenino , Humanos , Imagen por Resonancia Magnética/normas , Masculino , Red Nerviosa/diagnóstico por imagen , Ruido , Reproducibilidad de los Resultados , Descanso , Adulto Joven
2.
Br J Cancer ; 115(3): 354-63, 2016 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-27310702

RESUMEN

BACKGROUND: Previous studies have revealed that miR-26a-5p and miR-26b-5p act as tumour suppressors in various types of cancer tissues. Here, we aimed to investigate the functional roles of these miRNAs and to identify their regulatory targets in bladder cancer (BC). METHODS: We performed functional assays in BC cells using transfection of mature microRNAs (miRNAs). In silico and luciferase reporter analyses were applied to identify target genes of these miRNAs. The overall survival (OS) of patients with BC was evaluated by the Kaplan-Meier method. RESULTS: miR-26a-5p and miR-26b-5p were significantly downregulated in BC tissues. Restoration of these miRNAs inhibited cell migration and invasion in BC. The gene encoding procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2), a collagen crosslinking enzyme, was directly regulated by miR-26a-5p and miR-26b-5p. Kaplan-Meier analysis revealed that patients with high PLOD2 expression had significantly shorter OS compared with those with low PLOD2 expression (P=0.0153). CONCLUSIONS: PLOD2, which is associated with the stiffness of the extracellular matrix, was directly regulated by miR-26a-5p and miR-26b-5p and may be a good prognostic marker in patients with BC.


Asunto(s)
Genes Supresores de Tumor , MicroARNs/genética , Procolágeno-Lisina 2-Oxoglutarato 5-Dioxigenasa/genética , Neoplasias de la Vejiga Urinaria/patología , Línea Celular Tumoral , Proliferación Celular , Técnicas de Silenciamiento del Gen , Humanos , Invasividad Neoplásica , Metástasis de la Neoplasia , Neoplasias de la Vejiga Urinaria/genética
3.
Br J Cancer ; 113(2): 282-9, 2015 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-26057453

RESUMEN

BACKGROUND: Analysis of a microRNA (miRNA) expression signature of bladder cancer (BC) by deep-sequencing revealed that clustered miRNAs microRNA (miR)-451a, miR-144-3p, and miR-144-5p were significantly downregulated in BC tissues. We hypothesised that these miRNAs function as tumour suppressors in BC. The aim of this study was to investigate the functional roles of these miRNAs and their modulation of cancer networks in BC cells. METHODS: The functional studies of BC cells were performed using transfection of mature miRNAs. Genome-wide gene expression analysis, in silico analysis, and dual-luciferase reporter assays were applied to identify miRNA targets. The association between miR-144-5p levels and expression of the target genes was determined, and overall patient survival as a function of target gene expression was estimated by the Kaplan-Meier method. RESULTS: Gain-of-function studies showed that miR-144-5p significantly inhibited cell proliferation by BC cells. Four cell cycle-related genes (CCNE1, CCNE2, CDC25A, and PKMYT1) were identified as direct targets of miR-144-5p. The patients with high CCNE1 or CCNE2 expression had lower overall survival probabilities than those with low expression (P=0.025 and P=0.032). CONCLUSION: miR-144-5p functions as tumour suppressor in BC cells. CCNE1 and CCNE2 were directly regulated by miR-144-5p and might be good prognostic markers for survival of BC patients.


Asunto(s)
Ciclina E/genética , Ciclinas/genética , Genes Supresores de Tumor/fisiología , MicroARNs/fisiología , Proteínas Oncogénicas/genética , Neoplasias de la Vejiga Urinaria/mortalidad , Ciclo Celular , Proliferación Celular , Humanos , MicroARNs/análisis , Pronóstico , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/patología
4.
Horm Metab Res ; 43(3): 178-82, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21264794

RESUMEN

Intrauterine growth restriction (IUGR) is associated with a substantially greater incidence of metabolic syndrome in adulthood. Animal studies have shown that IUGR offspring are hyperphagic during the early postnatal period and therefore exhibit obesity. The molecular mechanisms underlying food intake regulation in the gastrointestinal tract have not been clarified in IUGR. In the present study, we utilized a rat model of IUGR by restricting the food intake of the mother (50% of the normal intake, ad libitum; FR group) from day 7 of gestation until delivery. Pups from undernourished mothers were fostered by control mothers. We examined the food intake and assessed the gene expressions of ghrelin, peptide YY (PYY), and cholecystokinin (CCK) in the alimentary tract of male newborns (postnatal day1) and adult offspring (age, 7 months). Compared to the offspring whose mothers received the standard diet ad libitum (CON offspring), FR offspring were hyperphagic from the weaning time until the end of the experiment, and resulted in a heavier final weight. Both newborn and adult FR offspring had higher ghrelin gene expression in the stomach and higher ghrelin plasma levels than did the controls. Although the gastrointestinal gene expressions and plasma levels of the anorexic peptides, PYY and CCK, were elevated in the FR newborns, they decreased in the FR adults. Our findings suggest that the altered gene expressions of orexigenic and anorexigenic gut peptides in the gastrointestinal tract in the maternal undernutrition-induced IUGR offspring provide a potential mechanism to explain hyperphagia and obesity seen in these offspring.


Asunto(s)
Colecistoquinina/genética , Retardo del Crecimiento Fetal/genética , Tracto Gastrointestinal/metabolismo , Ghrelina/genética , Hiperfagia/genética , Péptido YY/genética , Regulación hacia Arriba , Adulto , Animales , Animales Recién Nacidos , Peso Corporal , Colecistoquinina/sangre , Modelos Animales de Enfermedad , Ingestión de Alimentos , Femenino , Retardo del Crecimiento Fetal/sangre , Retardo del Crecimiento Fetal/fisiopatología , Tracto Gastrointestinal/crecimiento & desarrollo , Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Ghrelina/sangre , Humanos , Hiperfagia/sangre , Hiperfagia/fisiopatología , Masculino , Péptido YY/sangre , Ratas , Ratas Sprague-Dawley
5.
Horm Metab Res ; 42(11): 821-5, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20711951

RESUMEN

Peroxisomal proliferator-activated receptors (PPARs) play an important role in the regulation of lipid metabolism. The aim of this study was to investigate the effects of a maternal high-fat (HF) diet on serum lipid concentration and PPAR gene expression in liver and adipose tissue in the early life of the rat offspring. Female Sprague-Dawley rats were fed either an HF or control (CON) diet 6 weeks before mating and throughout gestation and lactation. Blood and tissue samplings of male offspring were carried out at birth or weaning. Birth weights were similar and serum triglyceride (TG) and nonesterified fatty acid (NEFA) levels showed no significant difference between HF and CON newborns, despite greatly increased hepatic PPARα mRNA expression in the HF newborns (p<0.05). Both HF newborns and weanlings revealed significantly decreased hepatic PPARγ expression compared with controls (p<0.0001). Hepatic PPARα expression in the HF weanlings was reduced markedly compared with CON weanlings (p<0.0001) and showed a negative correlation with serum TG levels (r=-0.743, p<0.05). However, epididymal expression of PPARγ in the HF weanlings was upregulated significantly compared with controls (p<0.05) and demonstrated a positive correlation with epididymal fat mass (r=0.733, p<0.05). These were accompanied by obesity as well as a rise in serum TG by 79% (p<0.05) and NEFA concentration by 36% (p<0.05) in these HF weanlings. Our findings suggest that maternal HF diet leads to alterations in PPAR gene expression in the weanling offspring, which is associated with the disturbed lipid homeostasis.


Asunto(s)
Grasas de la Dieta/farmacología , Lípidos/sangre , Receptores Activados del Proliferador del Peroxisoma/metabolismo , Animales , Animales Recién Nacidos , Peso Corporal/efectos de los fármacos , Femenino , Ratas , Ratas Sprague-Dawley
6.
Lupus ; 19(6): 717-26, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20026524

RESUMEN

Using proteomic analysis, we identified candidate autoantigens specific for central nervous system (CNS) involvement in systemic lupus erythematosus (SLE). Proteins, extracted from cultured human neuroblastoma cells, were separated both by SDS-PAGE (1-DE) and two-dimensional electrophoresis (2-DE), and transferred to membranes. Western blot analysis was performed using serum samples from 30 SLE patients with CNS involvement (CNS-Lupus) and from 30 SLE patients without CNS involvement (non-CNS-SLE). The detected autoantigens were identified using MALDI-TOF/TOF MS. On the 1-DE Western blot, we detected 32 antigenic bands in the serum samples from the CNS-Lupus patients. Among them, four bands were detected significantly more frequently in the CNS-Lupus patients than in the non-CNS-SLE patients. Three bands were detected in four or more of the CNS-Lupus patients but in only one or none of the non-CNS-SLE patients. We thus selected these seven bands for the next investigations. Next, we detected protein spots corresponding to the selected seven bands by 2-DE Western blot and identified four proteins. They are peroxiredoxin-4, ubiquitin carboxyl-terminal hydrolase isozyme L1, splicing factor arginine/serine-rich 3, and histone H2A type 1. These four candidate autoantigens for the anti-neuronal cell antibodies would be a useful marker for CNS-Lupus.


Asunto(s)
Autoantígenos/inmunología , Vasculitis por Lupus del Sistema Nervioso Central/inmunología , Adulto , Autoanticuerpos/sangre , Autoanticuerpos/inmunología , Autoantígenos/sangre , Biomarcadores/sangre , Línea Celular Tumoral , Electroforesis en Gel Bidimensional , Femenino , Histonas/inmunología , Humanos , Vasculitis por Lupus del Sistema Nervioso Central/sangre , Vasculitis por Lupus del Sistema Nervioso Central/fisiopatología , Masculino , Persona de Mediana Edad , Neuroblastoma , Peroxirredoxinas/inmunología , Proteínas de Unión al ARN/inmunología , Factores de Empalme Serina-Arginina , Ubiquitina Tiolesterasa/inmunología , Adulto Joven
7.
Clin Exp Rheumatol ; 28(1): 87-90, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20346245

RESUMEN

OBJECTIVE: Recent studies have disclosed that several genes are up-regulated in bone marrow (BM) mononuclear cells from rheumatoid arthritis (RA) patients. However, it remains unclear whether such abnormalities result from systemic inflammation or from abnormalities at stem cell level. The current study therefore examined the expression of several representative genes, including amphiregulin (AREG), chemokine receptor 4 (CXCR4), and FK506-binding protein 5 (FKBP5) in RA BM CD34+ cells. METHODS: BM samples were obtained from 52 patients with RA and 35 patients with osteroarthritis (OA) during joint operations. CD34+ cells were purified from the BM mononuclear cells by positive selection with magnetic beads. The mRNA expression for AREG, CXCR4, and FKBP5 was measured using quantitative real-time PCR. RESULTS: The expression of mRNA for FKBP5, but not that of AREG or CXCR4, was significantly higher in RA BM CD34+ cells than in OA BM CD34+ cells. The FKBP5 mRNA expression level was not correlated with serum CRP or treatment. In addition, tumour necrosis factor-alpha did not enhance the expression of FKBP5 mRNA in BM CD34+ cells from healthy donors. CONCLUSION: The results suggest that the enhanced expression of FKBP5 in BM CD34+ cells might be an intrinsic abnormality of RA BM CD34+ cells, whereas the enhanced expression of AREG and CXCR4 in BM mononuclear cells might be secondary to systemic inflammation.


Asunto(s)
Artritis Reumatoide/fisiopatología , Células de la Médula Ósea/fisiología , Proteínas de Unión a Tacrolimus/genética , Anciano , Anfirregulina , Antígenos CD34/metabolismo , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células Cultivadas , Familia de Proteínas EGF , Femenino , Expresión Génica/fisiología , Glicoproteínas/genética , Humanos , Péptidos y Proteínas de Señalización Intercelular/genética , Masculino , Persona de Mediana Edad , Osteoartritis/fisiopatología , ARN Mensajero/metabolismo , Receptores CXCR4/genética , Factor de Necrosis Tumoral alfa/metabolismo , Factor de Necrosis Tumoral alfa/farmacología
8.
J Environ Radioact ; 88(1): 90-100, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16513228

RESUMEN

Dead leaves were exposed to deuterated water vapor (D(2)O) as a substitute of tritiated water (HTO) in a greenhouse at daytime and nighttime to examine uptake and release of tritium by dead leaves because they cover a wide area of the forest floor and are therefore a major target material to be exposed when HTO is atmospherically derived to the forest. The dead cedar needles showed faster uptake and faster release rates during and after the exposure than the fresh ones, and the equilibrium concentration of the dead cedar needles was about two times higher than the fresh ones, indicating a quick response and a high buffering potential of dead leaves. The relation between uptake of D(2)O and number of stoma was examined for dead deciduous leaves; the species with larger number of stoma accumulated more D(2)O at the daytime and nighttime exposures. However, drying of the dead leaves suppressed D(2)O uptake greatly at daytime, suggesting stomata's opening and closing controls the D(2)O uptake of dead leaves.


Asunto(s)
Deuterio/análisis , Exposición a Riesgos Ambientales , Hojas de la Planta/química , Contaminación Radiactiva del Agua/análisis , Agua/química , Cryptomeria/química , Cryptomeria/fisiología , Hojas de la Planta/fisiología , Hojas de la Planta/efectos de la radiación , Factores de Tiempo
9.
J Am Coll Cardiol ; 21(4): 932-8, 1993 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-8450163

RESUMEN

OBJECTIVES: This study was performed to assess the length and contractile performance of human left ventricular papillary muscles and to determine the relation between papillary muscle dysfunction and mitral regurgitation. BACKGROUND: Assessment of human papillary muscle contractility remains a clinical challenge. METHODS: Two-dimensional echocardiographic examinations were performed in 16 normal subjects and 31 patients with prior myocardial infarction. Apical echocardiograms were used to obtain long-axis views of the anterior and posterior papillary muscles. The end-systolic and end-diastolic lengths of the papillary muscles were measured and fractional shortening was calculated. RESULTS: Fractional shortening in normal subjects was 27 +/- 8% for the anterior papillary muscle and 30 +/- 8% for the posterior papillary muscle. In patients with prior myocardial infarction, a significant decrease in fractional shortening was observed in proportion to the severity of left ventricular wall motion abnormalities at the site of papillary muscle implantation. Moderate or severe mitral regurgitation was significantly more frequent in patients with combined anterior and posterior papillary muscle dysfunction than in those with isolated anterior or posterior dysfunction or with normal function of both papillary muscles (p < 0.05). CONCLUSIONS: Two-dimensional echocardiography is useful for demonstrating abnormal contractility of human left ventricular papillary muscles. Papillary muscle contractility should be analyzed in each case to elucidate the mechanism of mitral regurgitation in patients with papillary muscle dysfunction.


Asunto(s)
Contracción Muscular , Infarto del Miocardio/fisiopatología , Músculos Papilares/fisiopatología , Adulto , Anciano , Cardiomiopatías/complicaciones , Cardiomiopatías/fisiopatología , Estudios de Casos y Controles , Ecocardiografía , Ecocardiografía Doppler , Femenino , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/etiología , Insuficiencia de la Válvula Mitral/fisiopatología , Infarto del Miocardio/complicaciones , Infarto del Miocardio/diagnóstico por imagen , Músculos Papilares/diagnóstico por imagen , Músculos Papilares/fisiología
10.
Am J Cardiol ; 82(3): 290-4, 1998 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-9708655

RESUMEN

There have been few studies on adenosine triphosphate (AT) stress echocardiography. The AT stress test may have fewer adverse effects than the adenosine stress test. The addition of atropine to AT echocardiography may enhance the sensitivity for detection of coronary artery disease (CAD). The purpose of this study was to determine the utility of AT-atropine echocardiography for detection of CAD. The group studied consisted of 112 patients with suspected CAD. Sixty-one patients did not have a history of prior myocardial infarction (group I) and 51 patients did (group II). AT was infused intravenously at 180 microg/kg/min for 14 minutes. Atropine (0.25 mg intravenously, repeated up to maximum total dose of 1 mg) was administered starting after 8 minutes of AT infusion. Ischemic response was defined as new or worsening wall motion abnormality occurring during the infusion. The sensitivity and specificity for detection of CAD were assessed using the representative echocardiograms during single AT infusion and AT-atropine infusion. Sixty-two patients had CAD. Fifty-eight patients (52%) developed minor side effects that resolved promptly. The rate-pressure product (10(3)/mm Hg beats/min) was significantly increased at 12 minutes of infusion (12.4+/-3.2) compared with that at baseline (9.1+/-2.3) and that at 6 minutes of infusion (9.4+/-2.1). The sensitivity for detection of CAD was 45% for AT echocardiography and 74% for AT-atropine echocardiography. The specificity was 94% for AT echocardiography and 90% for AT-atropine echocardiography. The sensitivity and specificity of AT-atropine echocardiography was 78% and 93%, respectively, in group I, and 70% and 86%, respectively, in group II. In conclusion, AT-atropine stress echocardiography seems to be well tolerated, safe, and useful for detection of CAD.


Asunto(s)
Adenosina Trifosfato , Atropina , Enfermedad Coronaria/diagnóstico por imagen , Ecocardiografía , Adenosina Trifosfato/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Atropina/administración & dosificación , Angiografía Coronaria , Enfermedad Coronaria/fisiopatología , Electrocardiografía , Prueba de Esfuerzo , Femenino , Hemodinámica , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Seguridad , Sensibilidad y Especificidad
11.
Clin Chim Acta ; 106(3): 235-42, 1980 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-7418226

RESUMEN

A rapid and accurate method is presented for the determination of manganese in biological samples, using neutron activation analysis. Biological samples were irradiated at 5000 kW for 30 min. The samples were ashed on a hot plate with 14 mol/l HNO3 and 6 mol/l HClO4, and resolved in 1 mol/l HClO4. 24Na and 24K were removed by passing each sample through in antimony pentoxide column. 54Mn was added as a tracer to calculate the ratio of manganese recovered by the separation procedure. Recovery was over 90%. This method was applied in order to determine manganese in various tissues. In the cervical spinal cord of the controls, the mean manganese concentrations in the anterior horn, the lateral and the posterior columns were 1.14, 1.06 and 0.90 ng/mg of dried tissue, respectively. In two cases if amyotrophic lateral sclerosis the manganese concentrations in the cervical spinal cord were elevated, particularly in the anterior horn and the lateral column.


Asunto(s)
Manganeso/análisis , Esclerosis Amiotrófica Lateral/metabolismo , Antimonio , Autopsia , Cobre/análisis , Humanos , Análisis de Activación de Neutrones/métodos , Distribución Tisular , Zinc/análisis
12.
J Pharm Sci ; 77(6): 481-8, 1988 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-3171925

RESUMEN

In order to quantitatively describe the peritoneal transport of drugs, this paper proposes a kinetic model that is based on the hydrodynamic pore theory of transcapillary exchange, and incorporates an explicit description of volume and osmolality changes in the dialysate. Sulfisoxazole (SIX) and benzoic acid (BA) were used as model compounds. Following intraperitoneal administration of dialysate in rats, the osmolality, volume, and drug concentration in the dialysate were measured with respect to time. The obtained data were analyzed to give hydrodynamic parameters for solvent and a solute (including drug) by a computer-aided curve-fitting procedure according to the differential equations derived from the model. The present method, requiring no approximation of the changes in dialysate volume, made it possible to predict the concentration profiles of BA under different initial conditions of dialysate (i.e., different osmolality and volume). Solvent drag effect contributed little to the peritoneal transport of SIX and slightly to that of BA. It was also found that the peritoneal transport of BA is blood-flow limited while that of SIX is diffusion limited.


Asunto(s)
Capilares/metabolismo , Diálisis Peritoneal , Preparaciones Farmacéuticas/metabolismo , Animales , Transporte Biológico Activo , Proteínas Sanguíneas/metabolismo , Masculino , Modelos Biológicos , Concentración Osmolar , Preparaciones Farmacéuticas/sangre , Unión Proteica , Ratas , Ratas Endogámicas
13.
J Pharm Sci ; 84(10): 1205-9, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8801335

RESUMEN

We attempted to reverse multidrug resistance (MDR) by treatment with 25-mer antisense phosphorothioate oligonucleotide. The phosphorothioate analogs, the sequences of which are sense or antisense to the initiation codon of mouse mdr1 mRNA, were tested against murine leukemic P388/S and adriamycin-resistant P388/ADR cell lines. A weak inhibitory effect on the growth of P388/S and P388/ADR cells was observed at a sense and antisense oligonucleotide concentration of 30 microM. Using the monoclonal antibody to P-glycoprotein and a flow cytometry technique, we showed that the level of expression of P-glycoprotein in P388/ADR cells treated with antisense oligonucleotide was lower than when treated with sense oligonucleotide. The antisense oligonucleotide potentiated the growth-inhibitory effect of vinblastine on P388/ADR cells, whereas sense oligonucleotide did not. This was accompanied by an increase in vinblastine retention in the cells. The reversal of the resistance by antisense oligonucleotide was increased by the combination with 1 microM verapamil. These results suggest that the antisense oligonucleotide and low dose verapamil may be useful in circumventing the resistance to anticancer drugs of MDR tumors.


Asunto(s)
Leucemia P388/tratamiento farmacológico , Oligonucleótidos Antisentido/farmacología , Tionucleótidos/farmacología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/efectos de los fármacos , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Animales , Antineoplásicos/farmacología , Secuencia de Bases , Bloqueadores de los Canales de Calcio/farmacología , Relación Dosis-Respuesta a Droga , Doxorrubicina/farmacología , Resistencia a Múltiples Medicamentos , Resistencia a Antineoplásicos , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Leucemia P388/genética , Leucemia P388/metabolismo , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Fenotipo , Verapamilo/farmacología , Vinblastina/farmacología
14.
J Pharm Sci ; 77(7): 559-64, 1988 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-3171941

RESUMEN

In order to examine quantitatively the effect of plasma protein binding on the peritoneal transport of beta-lactam antibiotics, we employed a kinetic model based on the pore theory of transcapillary exchange. This model incorporates the changes in the volume, osmolality, and antibiotic concentration in the dialysate, so that the apparent capillary membrane permeability (Pd) and the reflection coefficient (sigma d) of an antibiotic could be assessed. Six cephalosporins (cefatrizine, cefazolin, cefpiramide, ceftazidime, ceftriaxone, cephaloridine) were used as model compounds. While the unbound fractions of these antibiotics ranged widely from 0.08 to 0.57, including linear and nonlinear protein binding, the concentration-time profiles in plasma and the peritoneal dialysate after intravenous administration in rats could be interpreted well by our model, assuming that only the unbound antibiotic is available for the peritoneal transport. The estimated Pd values were almost the same among the drugs examined. Moreover, the Pd values of cefazolin in mice, rats, and rabbits exhibited a 0.83-power dependency on the animal body weight, indicating that Pd is significantly related to the peritoneal surface area. On the other hand, the sigma d values of cefazolin were found to be almost the same among the animal species examined. Finally, the concentration-time profile of cefazolin in the dialysate after intravenous administration in a patient with end-stage renal failure was successfully predicted using the Pd value extrapolated from those of the experimental animals.


Asunto(s)
Antibacterianos/metabolismo , Proteínas Sanguíneas/metabolismo , Anciano , Animales , Antibacterianos/sangre , Diálisis , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos , Concentración Osmolar , Peritoneo/metabolismo , Unión Proteica , Conejos , Ratas , Ratas Endogámicas , Especificidad de la Especie , beta-Lactamas
15.
Int J Pharm ; 229(1-2): 183-91, 2001 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-11604271

RESUMEN

We found that N-acetylation polymorphism can be evaluated from the disposition kinetics of sulfapyridine (SP) and 5-aminosalicylic acid (5-ASA) and their acetylated metabolites generated by N-acetyltransferase (NAT2) after oral administration of salicylazosulfapyridine (SASP). In 126 Japanese subjects, the homozygote of NAT2*4 was the most frequent (40%), followed by heterozygotes of NAT2*4 and mutant genes (28% NAT2*4/*6A, 15% NAT2*4/*7B, and 2% NAT2*4/*5B). Combinations of mutant genes accounted for 16%. When the relationship between the molar ratio of N-acetyl-SP (Ac-SP)/SP or N-acetyl-5-ASA(Ac-5-ASA)/5-ASA in serum and five genotypes of polymorphic NAT2* was examined in patients who received multiple doses of SASP, the molar ratios of Ac-SP/SP, rather than Ac-5-ASA/5-ASA tended to decrease according to the classification of genotype. We calculated the pharmacokinetic parameters in healthy subjects with various genotypes of polymorphic NAT2* after a single p.o. administration of SASP, according to a model of the SP metabolic pathways. The molar ratios of Ac-SP/SP in serum and urine were simulated using these parameters, and the molar ratio of Ac-SP/SP in urine at 4 days after the first administration could be categorized into ranges that were specific to various NAT2* genotypes. Thus, we were able to predict the N-acetylation polymorphic genotypes of patients by measuring the molar ratio of Ac-SP/SP in urine, after administration of SASP.


Asunto(s)
Polimorfismo Genético/genética , Sulfasalazina/orina , Acetilación , Adulto , Ácidos Aminosalicílicos/farmacocinética , Biotransformación , ADN/genética , ADN/aislamiento & purificación , Genotipo , Humanos , Modelos Biológicos , Fenotipo , Valor Predictivo de las Pruebas , Sulfapiridina/farmacocinética , Sulfasalazina/farmacocinética , Tuberculosis/metabolismo
16.
J Pharm Pharmacol ; 48(4): 347-50, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8794981

RESUMEN

To evaluate the dose dependency in apparent peritoneal permeability (Pd) of benzoic acid as a model compound for a monocarboxylic acid transport system, a kinetic model, which involves changes in the volume and osmolality of the dialysate as well as the diffusion and convection of drugs across the peritoneum, was applied. We compared the Pd value of benzoic acid to that of phenobarbital which is a more lipophilic drug than benzoic acid. The concentration-time courses of phenobarbital in both peritoneal cavity and serum after the intraperitoneal administration with various doses were parallel according to dose, whereas those of benzoic acid varied in a dose-dependent manner. Using the values of unbound fraction (Fu), the value of Pd for unbound drugs was estimated. The Pd values of benzoic acid at 20 micrograms mL-1 was three times the value determined at 1000 micrograms mL-1. We suggest that certain facilitated transport systems constitute the mechanism of enhanced peritoneal membrane permeability of benzoic acid.


Asunto(s)
Benzoatos/farmacocinética , Peritoneo/metabolismo , Animales , Benzoatos/administración & dosificación , Ácido Benzoico , Transporte Biológico Activo , Permeabilidad Capilar , Fenómenos Químicos , Química Física , Hipnóticos y Sedantes/farmacocinética , Inyecciones Intraperitoneales , Masculino , Peso Molecular , Concentración Osmolar , Fenobarbital/farmacocinética , Ratas , Ratas Wistar
17.
Ann Nucl Med ; 12(1): 15-20, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9559957

RESUMEN

The relationship between bone mineral density in elderly women and the pattern of skeletal uptake of 99mTc-HMDP, especially in regard to skull uptake, was investigated. The whole-body skeletal uptake (WBSU) and whole-body skeletal tracer distribution patterns were studied in 86 disease-free women on bone scintigraphy with 99mTc-hydroxy-methylene-diphosphonate (HMDP). Bone scans were quantified by setting regions of interest (ROI) and bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry in all patients. WBSU and the skeletal distribution pattern were compared with bone mineral densities of the entire skeleton as well as selected regions. WBSU was high in the elderly and negatively correlated with regional bone mineral densities (r = -0.403 to -0.534). Among the regions, uptake by the skull increased with age more than in other regions in women and had the highest negative correlation with the bone mineral density. The skull uptake correlated negatively with total body BMD (r = -0.583) and with lumbar BMD (r = -0.561, p < 0.0001). Our results show that increased radionuclide uptake in bone scintigraphy, especially skull uptake was associated with decreased bone mineral density in elderly women, so that, increased skull uptake in elderly women would be a scintigraphic sign of post-menopausal or senile osteopenia.


Asunto(s)
Densidad Ósea , Huesos/diagnóstico por imagen , Medronato de Tecnecio Tc 99m/análogos & derivados , Absorciometría de Fotón , Adulto , Anciano , Envejecimiento/metabolismo , Femenino , Humanos , Persona de Mediana Edad , Cintigrafía , Cráneo/diagnóstico por imagen
18.
Biol Trace Elem Res ; 71-72: 331-42, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10676508

RESUMEN

Phytoplankton samples were collected during spring bloom of diatoms from three coastal areas of Japan using a NORPAC P-25 net (25-micron opening) with a NGG52 prenet (335-micron opening), and 25 major and trace elements have been analyzed by INAA. Concentration ranges of analyzed phytoplankton samples are much wider than the concentration ranges compiled by Bowen (1979) except for As, and data of marine phytoplankton samples for Br, Sb, Hf, Sc, La, Ce, Sm, and Eu were not included in the compilation. The 25 analyzed elements have been categorized into three groups: elements showing positive correlation with Br, positive correlation with Al, and no positive correlation with Br or Al. The marine phytoplankton samples have been plotted on a Masuzawa-Koyama-Terazaki (MKT) plot and it proved that the MKT plot is applicable to marine phytoplankton samples.


Asunto(s)
Fitoplancton/química , Oligoelementos/análisis , Japón , Biología Marina , Análisis de Activación de Neutrones
19.
Kyobu Geka ; 44(12): 1030-2, 1991 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-1758106

RESUMEN

A 33-year-old female who had undergone closure of VSD 20 years before, was hospitalized for sudden onset of dyspnea without history of febrile or traumatic disorder. On admission, she had cyanotic lips and nailbeds but no clubbed finger. Chest x-ray film showed neither lung congestion nor cardiomegaly. Arterial blood gas analysis revealed deep hypoxia (PaO2 = 49.6 mmHg). Echocardiogram clarified massive tricuspid regurgitation (TR) due to chordal rupture of anterior leaflet, small VSD jet stream through the membranous aneurysm and a great deal of R-L shunt on the atrial level through a persistent foramen ovale. Cardiac catheterization data confirmed 35% of R-L shunt. At operation, a torn chordal tendon of anterior leaflet and an adhered septal leaflet to aneurysm of membranous portion of ventricular septum were seen. There were two pledgets, used at the first surgery, at the base of the aneurysm and a couple of tiny holes (VSDs) above and below the pledgets were recognized. Following resection of anterior and posterior leaflet, plication of septal leaflet and closure of VSD, a Xenograft valve (Carpentier-Edwards 29-M) was implanted. Then persistent foramen ovale, 20 x 20 mm in large, was closed directly. Her postoperative course was excellent with disappearance of cyanosis, normalized oxygen saturation in arterial blood and improved activity without dyspnea.


Asunto(s)
Defectos del Tabique Interatrial/cirugía , Hipoxia/etiología , Insuficiencia de la Válvula Tricúspide/cirugía , Adulto , Cuerdas Tendinosas , Femenino , Rotura Cardíaca/complicaciones , Defectos del Tabique Interatrial/complicaciones , Defectos del Tabique Interventricular/complicaciones , Humanos , Insuficiencia de la Válvula Tricúspide/complicaciones
20.
Nihon Rinsho ; 56(6): 1458-63, 1998 Jun.
Artículo en Japonés | MEDLINE | ID: mdl-9648465

RESUMEN

Over the past decade, methodologies for the assessment of bone mineral density have markedly progressed, so that any sites of the skeleton now can be measured with high degree of accuracy and precision with safety. The number of devices distributed in Japan rapidly increased for the last 5 years and the total number installed nationwide reached over 7000 as with 1998. There are variety of techniques: microdensitometry (MD) or radiographic absorptiometry (RA), single X-ray absorptiometry (SXA), dual X-ray absorptiometry (DXA), quantitative CT (QCT), peripheral QCT, and quantitative ultrasonometry (QUS). There are, however, no such single technique as to fulfill the entire clinical requirements, since the time of initiation of bone loss, and the speed of bone loss are quite different from site to site of the skeleton, so that the correlations of bone density measured by each technique are not sufficiently high (gamma = 0.5-0.8) to predict BMD of other bones by measuring one bone. Since the relatively large amounts of data on the prediction of fracture (hip, spine and others) by these techniques have been accumulated, a specific guideline regarding the appropriate application of these techniques, including multiple combination measurements, should be established based on the worldwide consensus.


Asunto(s)
Densidad Ósea , Humanos , Métodos , Osteoporosis/diagnóstico
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA