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1.
Mol Hum Reprod ; 27(6)2021 05 29.
Artículo en Inglés | MEDLINE | ID: mdl-33983443

RESUMEN

Endometriosis is characterised by inflammation and fibrotic changes. Our previous study using a mouse model showed that proinflammatory factors present in peritoneal haemorrhage exacerbated inflammation in endometriosis-like grafts, at least in part through the activation of prostaglandin (PG) E2 receptor and protease-activated receptor (PAR). In addition, hypoxia is a well-known inducer of fibrosis that may be associated with epithelial-mesenchymal transition (EMT). However, the complex molecular interactions between hypoxia and proinflammatory menstruation-related factors, PGE2 and thrombin, a PAR1 agonist, on EMT in endometriosis have not been fully characterised. To explore the effects of hypoxia and proinflammatory factors on EMT-like changes in endometrial cells, we determined the effects of PGE2 and thrombin (P/T) on EMT marker expression and cell migration in three dimensional cultured human endometrial epithelial cells (EECs) and endometrial stromal cells (ESCs). Treatment of EECs with P/T under hypoxia stimulated cell migration, increased the expression of mesenchymal N-cadherin, vimentin and C-X-C chemokine receptor type 4 (CXCR4), and reduced the expression of epithelial E-cadherin. Furthermore, treatment with C-X-C motif chemokine ligand 12 (CXCL12), a ligand for CXCR4, increased EMT marker expression and cell migration. In ESCs, P/T or oestrogen treatment under hypoxic conditions increased the expression and secretion of CXCL12. Taken together, our data show that hypoxic and proinflammatory stimuli induce EMT, cell migration and inflammation in EECs, which was increased by CXCL12 derived from ESCs. These data imply that inflammatory mediators in retrograde menstrual fluid contribute to ectopic endometrial EMT and migration in the presence of peritoneal hypoxia.


Asunto(s)
Hipoxia de la Célula , Endometriosis/etiología , Endometrio/patología , Transición Epitelial-Mesenquimal , Trastornos de la Menstruación/patología , Menstruación/fisiología , Adulto , Biomarcadores , Técnicas de Cultivo Tridimensional de Células , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Quimiocina CXCL12/metabolismo , Quimiocina CXCL12/farmacología , Dinoprostona/farmacología , Endometriosis/patología , Endometrio/metabolismo , Células Epiteliales/efectos de los fármacos , Estradiol/farmacología , Femenino , Expresión Génica , Humanos , Inflamación , Mediadores de Inflamación/metabolismo , Trastornos de la Menstruación/metabolismo , Esferoides Celulares , Células del Estroma/efectos de los fármacos , Trombina/farmacología
2.
Osteoporos Int ; 32(4): 671-680, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32968889

RESUMEN

The effects of the age at estrogen replacement therapy (ERT) initiation on bone quality in Turner syndrome were evaluated using trabecular bone score. Early puberty ERT positively correlated with increase in bone quality. Early initiation of ERT is necessary for the acquisition of bone quality as well as bone density. INTRODUCTION: Studies have reported associations between bone mineral density and estrogen replacement therapy (ERT) in Turner syndrome (TS) patients; however, few studies exist on the effect on bone quality. The aim of this study was to evaluate the effects of the age at ERT initiation on bone quality of Japanese TS patients, cross-sectionally and longitudinally. METHODS: Cross-sectionally, 95 TS patients were divided into three groups based on their age at initiation of ERT: A (12-14 years, 11 patients), B (15-17 years, 47 patients), and C (over 18 years, 37 patients). To assess bone quality, trabecular bone score (TBS) was used. The effects of age at initiation and duration of ERT on TBS were examined using multiple regression analysis. In the longitudinal study, 48 patients who underwent dual-energy X-ray absorptiometry multiple times were divided into three groups: D (12-14 years, 8 patients), E (15-17 years, 18 patients), and F (over 18 years, 22 patients). Each group was analyzed for the rate of change in TBS per year. RESULTS: Cross-sectionally, the TBS showed significant differences among the three groups (TBS A, 1.302; B, 1.299; C, 1.245) (p = 0.013); group C was significantly lower than B (p = 0.014); bone quality was degraded. Multiple regression analysis revealed that age at ERT initiation significantly affected the increase in TBS (p = 0.002). Longitudinally, the rate of change of TBS was not significantly different in the three groups (p = 0.73). CONCLUSION: Early initiation of ERT may have positive effects on bone quality in TS. Large prospective studies will be needed.


Asunto(s)
Hueso Esponjoso , Síndrome de Turner , Absorciometría de Fotón , Adulto , Densidad Ósea , Hueso Esponjoso/diagnóstico por imagen , Terapia de Reemplazo de Estrógeno , Femenino , Humanos , Japón , Estudios Longitudinales , Vértebras Lumbares , Estudios Prospectivos , Síndrome de Turner/tratamiento farmacológico
3.
Scand J Med Sci Sports ; 28(4): 1339-1344, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29247985

RESUMEN

To examine the effect of a 12-week slow movement resistance training using body weight as a load (SRT-BW) on muscle mass, strength, and fat distribution in healthy elderly people. Fifty-three men and 35 women aged 70 years old or older without experience in resistance training participated, and they were randomly assigned to a SRT-BW group or control group. The control group did not receive any intervention, but participants in this group underwent a repeat measurement 12 weeks later. The SRT-BW program consisted of 3 different exercises (squat, tabletop push-up, and sit-up), which were designed to stimulate anterior major muscles. Initially, these exercises were performed by 2 sets of 10 repetitions, and subsequently, the number of repetitions was increased progressively by 2 repetitions every 4 weeks. Participants were instructed to perform each eccentric and concentric phase of movement slowly (spending 4 seconds on each movement), covering the full range of motion. We evaluated muscle mass, strength, and fat distribution at baseline and after 12 weeks of training. Changes over 12 weeks were significantly greater in the SRT-BW group than in the control group, with a decrease in waist circumference, hip circumference, and abdominal preperitoneal and subcutaneous fat thickness, and an increase in thigh muscle thickness, knee extension strength, and hip flexion strength. In conclusion, relatively short-term SRT-BW was effective in improving muscle mass, strength, and fat distribution in healthy elderly people.


Asunto(s)
Fuerza Muscular , Músculo Esquelético/fisiología , Entrenamiento de Fuerza/métodos , Grasa Abdominal , Anciano , Distribución de la Grasa Corporal , Peso Corporal , Femenino , Humanos , Masculino , Rango del Movimiento Articular , Sarcopenia/prevención & control , Grasa Subcutánea , Circunferencia de la Cintura
5.
Transplant Proc ; 46(4): 1251-3, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24815173

RESUMEN

Induction and promotion of angiogenesis play a role in a diverse range of physiologic and pathophysiologic processes that are especially relevant to the field of regenerative medicine. For assessing vasculogenesis and neo-angiogenesis, identifying angiogenic factors, angiocrine factors, and vascular niche, facilitating tissue-repair and tumor growth, efficiently generating induced pluripotent stem cells, and coculturing with organ-specific stem cells, isolation and characterization of the subpopulation of human umbilical vein endothelial cells (HUVECs) and their endothelial progenitor cells (EPCs) are needed. In this study, primary HUVECs were collected from fresh umbilical cords and fractionated and characterized with the use of flow cytometry. Clonal colony assay showed that endothelial colony-forming units in culture frequently existed in fresh HUVECs. Antigenic profiling demonstrated that undifferentiated EPCs in HUVECs had normal endothelial marker CD31 with a subpopulation of cells positive for hematopoietic stem cell marker CD34 and c-Kit. With continuing passages, EPC markers CD34 and vascular endothelial growth factor receptor 2 expression decreased dramatically. Moreover, a distinct subpopulation with different proliferative capability and angiogenesis from the early-passage HUVECs was shown. In conclusion, it is possible to isolate accurately and to enrich EPCs or hematoangioblast-like cells from a heterogeneous population of HUVECs, and to explore the differential process with flow cytometry for further investigations.


Asunto(s)
Células Endoteliales de la Vena Umbilical Humana/fisiología , Neovascularización Fisiológica , Células Madre/fisiología , Antígenos CD34/metabolismo , Biomarcadores/metabolismo , Diferenciación Celular , Proliferación Celular , Separación Celular/métodos , Células Cultivadas , Citometría de Flujo , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Fenotipo , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Proteínas Proto-Oncogénicas c-kit/metabolismo , Células Madre/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo
6.
Environ Toxicol ; 28(1): 21-30, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21384493

RESUMEN

Chlorinated benz[a]anthracenes (Cl-BaA) are halogenated aromatic compounds (typified by dioxins) found in the environment at relatively high concentrations. Fischer 344 rats were intragastrically administered 0, 1, or 10 mg of Cl-BaA or its parent compound benz[a]anthracene (BaA) per kg of body weight for 14 consecutive days. Both chemicals at 10 mg/kg/day inhibited the gain in body weight, and consequent increase in relative liver weight. Hepatic gene expression of cytochrome P450 (CYP) 1A1, 1A2, and 1B1 was significantly stimulated by administration of BaA (10 mg/kg/day) compared with the control. After administration of Cl-BaA, only the CYP1A2 gene was significantly induced, even at the lower dosage; CYP1A1 and 1B1 mRNA levels remained unchanged in Cl-BaA-treated rats compared with controls. To elucidate the role of such Cl-BaA exposure and induced CYPs at toxicity onset, we investigated the mutagenicity of BaA and Cl-BaA using Salmonella typhimurium TA98 and TA100. BaA and Cl-BaA at 10 µg/plate produced positive results in both strains in the presence of rat S-9. Incubation of Cl-BaA with recombinant rat CYP1A2 produced a significantly higher number of revertant colonies in TA98 and TA100 than in controls, but no such change was observed for BaA. In conclusion, BaA changes its own physiological and toxicological actions by its chlorination; (1) daily exposure to Cl-BaA selectively induces hepatic CYP1A2 in rats and (2) Cl-BaA induces frameshift mutations in the presence of CYP1A2, although BaA does not exert mutagenicity. This indicates that CYP1A2 may metabolize Cl-BaA to active forms.


Asunto(s)
Benzo(a)Antracenos/toxicidad , Hígado/efectos de los fármacos , Mutágenos/toxicidad , Salmonella typhimurium/efectos de los fármacos , Animales , Hidrocarburo de Aril Hidroxilasas/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1A2 , Citocromo P-450 CYP1B1 , Citocromos/metabolismo , Mutación del Sistema de Lectura , Regulación de la Expresión Génica/efectos de los fármacos , Halogenación , Hígado/metabolismo , Masculino , Pruebas de Mutagenicidad , Ratas , Ratas Endogámicas F344 , Salmonella typhimurium/metabolismo
7.
Ultramicroscopy ; 111(6): 405-8, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21664540

RESUMEN

A 90° sector type spin rotator was developed for measurement of the z-direction component of a spin polarization, which is parallel to the emitter axis. The rotator enables us to measure all components of electron spins field-emitted from a single crystalline magnetite. In-plane component of spin polarization dominated of field-emitted electrons from single crystalline magnetite whisker, thus it is suggested that the magnetization of the magnetite whisker results from the anisotropy of crystalline structure rather than its shape.

8.
Int J Obes (Lond) ; 30(3): 528-33, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16247505

RESUMEN

OBJECTIVE: To examine a possible relationship between obesity, job stress, and eating behavior in male Japanese workers. METHOD: A questionnaire on life style, job stress, and eating behavior was conducted with 208 male workers aged 19-60 years (33.7+/-12.3 years) in a manufacturing industry in Japan. Height and weight were measured in an annual health examination. The relation between obesity, job stress, and eating behavior were analyzed between 141 nonobese subjects (BMI or=25.0 kg/m(2)). RESULTS: Obesity was associated with psychological stress responses of tension/anxiety, especially tension. Tension/anxiety was also related to job demands positively and job latitudes negatively. The eating behaviors of subjects with tension/anxiety resembled those of the obese subjects. CONCLUSIONS: The present study suggests that obese male Japanese workers tend to be in a stressful state from high job demands and low job latitudes in the workplace. Such stressful conditions may affect eating behaviors to eat much and contribute to obesity. Stress management might be necessary in the workplace for the prevention of obesity among male Japanese workers.


Asunto(s)
Bulimia/psicología , Conducta Alimentaria/psicología , Obesidad/etiología , Enfermedades Profesionales/complicaciones , Estrés Psicológico/complicaciones , Adulto , Índice de Masa Corporal , Humanos , Estilo de Vida , Masculino , Persona de Mediana Edad , Obesidad/psicología , Enfermedades Profesionales/psicología , Psicometría , Estrés Psicológico/psicología , Encuestas y Cuestionarios
9.
J Struct Biol ; 146(1-2): 205-16, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15037251

RESUMEN

Dynein ATPases contain six concatenated AAA modules within the motor region of their heavy chains. Additional regions of sequence are required to form a functional ATPase, which a previous study suggested forms seven or eight subdomains arranged in either a ring or hollow sphere. A more recent homology model of the six AAA modules suggests that these form a ring. Therefore both the number and arrangement of subdomains remain uncertain. We show two-dimensional projection images of dynein-c in negative stain which reveal new details of its structure. Initial electron cryomicroscopy shows a similar overall morphology. The molecule consists of three domains: stem, head, and stalk. In the absence of nucleotide the head has seven lobes of density forming an asymmetric ring. An eighth lobe protrudes from one side of this heptameric ring and appears to join the elongated cargo-binding stem. The proximal stem is flexible, as is the stalk, suggesting that they act as compliant elements within the motor. A new analysis of pre- and post-power stroke conformations shows the combined effect of their flexibility on the spatial distribution of the microtubule-binding domain and therefore the potential range of power stroke sizes. We present and compare two alternative models of the structure of dynein.


Asunto(s)
Dineínas/química , Proteínas Protozoarias/química , Animales , Chlamydomonas reinhardtii/química , Dineínas/aislamiento & purificación , Dineínas/ultraestructura , Microscopía Electrónica , Modelos Moleculares , Proteínas Motoras Moleculares
10.
Int Arch Occup Environ Health ; 75(1-2): 106-10, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11898869

RESUMEN

OBJECTIVES: The purpose of the study was to assess quantitative measurements of the manipulative dexterity of patients suffering from hand-transmitted vibration disorder, and to investigate a possible link with impaired tactile perception in their hands. SUBJECTS AND METHODS: The subjects were 30 patients with hand-arm vibration syndrome, 30 office workers and 20 manual laborers of similar ages. Manipulative dexterity was assessed by measuring the performance time of buttoning-unbuttoning a work jacket with five buttons and of picking up and transferring 30 red beans, one by one, with the fingers from one plate to another. Patients were also examined on vibrotactile thresholds at 125 Hz as well as pain thresholds. RESULTS: The buttoning-unbuttoning time and the bean transfer time were significantly prolonged in the patients compared with the worker groups. The patients showed a close correlation between the buttoning-unbuttoning time and the bean transfer time. Performance times did not differ between patients with vibration-induced white finger and those without it. Those times also correlated with the vibrotactile and pain thresholds in the patients. When a cut-off value was set at 2 SDs from the mean performance times of the manual laborers, exceeding the cut-off value was found in 70% of the patients for the button-unbutton test and in 80% of those for the bean transfer test. All patients with moderately or severely increased vibrotactile and pain thresholds exceeded that value in performing the two tasks. CONCLUSION: The present measurements quantitatively showed impaired manipulation in patients with hand-arm vibration syndrome. Such difficulty with manipulation seems to be associated with the impaired tactile sensation in their hands.


Asunto(s)
Brazo/fisiopatología , Mano/fisiopatología , Destreza Motora , Enfermedades Profesionales/fisiopatología , Vibración/efectos adversos , Estudios de Casos y Controles , Humanos , Japón , Masculino , Enfermedades Profesionales/etiología , Umbral del Dolor , Síndrome
11.
Int Arch Occup Environ Health ; 75(1-2): 90-6, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11898882

RESUMEN

OBJECTIVES: The aim of the present study was to ascertain the usefulness of thermotactile testing under the measuring conditions clarified by our previous study in the evaluation of vibration-induced neuropathy. METHOD: Thermal (warm and cold) thresholds were examined on the index fingers of both hands of ten patients with hand-arm vibration syndrome, 36 workers exposed to hand-transmitted vibration, and ten healthy controls, using an aesthesiometer under the following measuring conditions: change rate of the applicator temperature was fixed at a rate of 1 degrees C/s; finger contact force on the applicator was kept at 0.5 N; and forearm was positioned on a support. Vibrotactile thresholds at 125 Hz and pain thresholds were also measured on the index fingers. RESULTS: Both warm and cold thresholds had more severely deteriorated in the patients than in the controls. Vibrotactile and pain thresholds were also increased in the patients. In the vibration-exposed workers, the neutral zone between the warm and cold threshold differed from in the controls. Thermotactile thresholds were likely to have deteriorated with advanced nerve impairment. Likelihood ratios of thermotactile testing were significantly high between the patients and the controls. For vibration-exposed workers with elevated vibrotactile and pain thresholds, the ratios were also significantly high, particularly in the neutral zone, though the accuracy tended to be lower than in the patients. Thermotactile thresholds appeared to be more closely correlated with pain thresholds than vibrotactile thresholds. CONCLUSIONS: Thermotactile threshold testing under the present measuring conditions can be useful for evaluating small sensory nerve fibre dysfunction in vibration-exposed subjects, and the neutral zone may be a sensitive indicator in vibration-exposed workers who may have slight or mild nerve impairments.


Asunto(s)
Dedos/inervación , Enfermedades Profesionales/fisiopatología , Enfermedades del Sistema Nervioso Periférico/fisiopatología , Células Receptoras Sensoriales/fisiopatología , Umbral Sensorial , Vibración/efectos adversos , Adulto , Anciano , Estudios de Casos y Controles , Dedos/fisiopatología , Humanos , Japón , Persona de Mediana Edad , Enfermedades Profesionales/etiología , Enfermedades del Sistema Nervioso Periférico/etiología , Sensibilidad y Especificidad
12.
J Biol Phys ; 28(3): 335-45, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23345779

RESUMEN

Dynein from inner arms of Chlamydomonasflagella contains sevendistinct subspecies, a through g. Several lines of evidence suggest thesesubspecies play important roles in generating flagellar beating and thatthe different subspecies are functionally diverse. To evaluate theirroles and diversity, the mechanical properties of subspecies-c, which isa single-headed motor, were examined using optical trap nanometry. Apolystyrene bead coated with a small number of subspecies-c moleculeswas captured with the optical trap and brought into contact with amicrotubule fixed to a coverslip. Movements of the bead were measured bya quadrant photodiode sensor with sub-nanometer- and millisecond-resolution.Beads carrying a single active subspecies-c molecule moved processivelyalong the microtubules in 8-nm steps but slipped backwards under highloads. Force-velocity relationships of single subspecies-c molecules werealmost linear and the shapes of the normalized curves at 5 µM and 100µM ATP were similar. These results indicate that dynein subspecies-cfunctions in a very different way from conventional motor proteins, suchas myosin and kinesin, and has properties that could produceself-oscillation in vivo.

13.
Gynecol Obstet Invest ; 52(2): 142-4, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11586045

RESUMEN

We report a case of fetal congenital heart block treated with maternal administration of beta-sympathomimetics. The case was diagnosed as fetal complete heart block associated with maternal anti-Ro/SS-A antibody at 22 weeks of gestation. By fetal sonography, the ventricular rate was revealed to be 60 beats/min and mild cardiomegaly was shown. We initiated maternal administration of a sympathomimetic, specifically terbutaline, to prevent fetal heart failure. An increase in the fetal ventricular rate and an improvement in cardiac function were both achieved during the treatment. A viable infant was delivered by an elective cesarean section without complications at term. Maternal administration of the beta-adrenergic agent terbutaline is suggested to be effective for improving fetal congenital heart block in order to prevent heart failure in utero.


Asunto(s)
Enfermedades Fetales/tratamiento farmacológico , Bloqueo Cardíaco/congénito , Bloqueo Cardíaco/tratamiento farmacológico , Simpatomiméticos/administración & dosificación , Simpatomiméticos/uso terapéutico , Terbutalina/administración & dosificación , Terbutalina/uso terapéutico , Adulto , Cardiotocografía , Femenino , Enfermedades Fetales/diagnóstico por imagen , Corazón Fetal/diagnóstico por imagen , Corazón Fetal/efectos de los fármacos , Bloqueo Cardíaco/diagnóstico por imagen , Insuficiencia Cardíaca/prevención & control , Frecuencia Cardíaca Fetal/efectos de los fármacos , Humanos , Atención Prenatal , Ultrasonografía Prenatal
14.
Intern Med ; 40(7): 643-5, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11506308

RESUMEN

We report the case of a severe bronchial asthma attack 15 minutes after the ingestion of food containing small amounts of alcohol. Although an ethanol inhalation test was negative, an acetaldehyde inhalation test was positive. Furthermore, it was discovered that the patient was homozygous for a mutation of the aldehyde dehydrogenase-2 (ALDH-2) gene. We subsequently diagnosed his attack as acute severe alcohol-induced asthma. Since bronchial asthma patients who are homozygous for mutant ALDH-2 genes are susceptible to acute severe alcohol-induced asthma attacks, strict clinical attention is thought a necessity.


Asunto(s)
Aldehído Deshidrogenasa/genética , Asma/inducido químicamente , Asma/metabolismo , Etanol/efectos adversos , Acetaldehído/efectos adversos , Anciano , Aldehído Deshidrogenasa Mitocondrial , Asma/fisiopatología , Etanol/metabolismo , Volumen Espiratorio Forzado , Homocigoto , Humanos , Masculino , Mutación , Índice de Severidad de la Enfermedad
15.
Inflammation ; 25(3): 197-201, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11403211

RESUMEN

In this study we investigated the effect of adrenomedullin (AM) on fMLP-mediated activation of human neutrophils. AM partially, but significantly, suppressed fMLP-induced upregulation of CD11b expression. The inhibitory effects of AM upon fMLP-induced upregulation of CD11b expression were completely blocked by CGRP [8-37], a CGRP receptor antagonist. AM significantly increased cAMP content in neutrophils and SQ-22,536, an adenylate cyclase inhibitor, and KT-5720, a PKA inhibitor, significantly blocked the inhibitory effects of AM upon fMLP-induced upregulation of CD11b expression. This study indicates that binding of AM to the CGRP receptor suppresses fMLP-induced upregulation of CD11b expression of human neutrophils by increasing intracellular cAMP levels. AM may play an important role in the regulation of inflammatory processes, especially in the binding of neutrophils to vascular endothelial cells and subsequent neutrophil emigration evident in acute pulmonary inflammation.


Asunto(s)
Adenina/análogos & derivados , Antígeno de Macrófago-1/metabolismo , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/efectos de los fármacos , Neutrófilos/inmunología , Péptidos/farmacología , Adenina/farmacología , Inhibidores de Adenilato Ciclasa , Adrenomedulina , Péptido Relacionado con Gen de Calcitonina/farmacología , Antagonistas del Receptor Peptídico Relacionado con el Gen de la Calcitonina , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Interacciones Farmacológicas , Inhibidores Enzimáticos/farmacología , Humanos , Técnicas In Vitro , Inflamación/etiología , Neutrófilos/metabolismo , Fragmentos de Péptidos/farmacología , Péptidos/fisiología , Regulación hacia Arriba/efectos de los fármacos
16.
J Biol Chem ; 276(28): 26405-10, 2001 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-11313355

RESUMEN

The initial step in the de novo biosynthesis of cytokinin in higher plants is the formation of isopentenyladenosine 5'-monophosphate (iPMP) from AMP and dimethylallylpyrophosphate (DMAPP), which is catalyzed by adenylate isopentenyltransferase (IPT). Although cytokinin is an essential hormone for growth and development, the nature of the enzyme for its biosynthesis in higher plants has not been identified. Herein, we describe the molecular cloning and biochemical identification of IPTs from Arabidopsis thaliana. Eight cDNAs encoding putative IPT, designated as AtIPT1 to AtIPT8, were picked up from A. thaliana. The Escherichia coli transformants expressing the recombinant proteins excreted cytokinin species into the culture medium except for that expressing AtIPT2 that is a putative tRNA IPT. A purified recombinant AtIPT1 catalyzed the formation of iPMP from DMAPP and AMP. These results indicate that the small multigene family contains both types of isopentenyltransferase, which could synthesize cytokinin and mature tRNA.


Asunto(s)
Transferasas Alquil y Aril/genética , Arabidopsis/enzimología , Arabidopsis/genética , Secuencia de Aminoácidos , Clonación Molecular , Citocinas/biosíntesis , Citocinas/genética , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Datos de Secuencia Molecular , Alineación de Secuencia
17.
J Control Release ; 71(1): 71-86, 2001 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-11245909

RESUMEN

T-0128 is a novel camptothecin (CPT) analogue (T-2513: 7-ethyl-10-aminopropyloxy-CPT)-carboxymethyl (CM) dextran conjugate via a Gly-Gly-Gly linker, with a molecular weight (MW) of 130 kDa. Our previous studies demonstrated that T-0128 has strong antitumor activity against human tumor xenografts that are highly refractory to CPT analogues attributable to the passive tumor targeting of released T-2513. This study examines the effects of carrier, dose, and tumor on T-0128 pharmacokinetics. To study carrier effect, tumor-bearing rats received one i.v. injection of fluorescein isothiocyanate (FITC)-labeled CM dextran with a different degree of substitution (DS) of the carboxymethylated groups and a different MW. Results showed that CM dextran from Dextran T-110 (MW 110 kDa) with a DS value of 0.4 is an appropriate drug carrier for T-0128 regarding plasma half-life and passive tumor targeting. To study dose and tumor effects, non-tumor- and tumor-bearing rats were treated with T-0128 doses ranging from 1 to 25 mg/kg (based on the amount of T-2513 bound to CM dextran). Dose-dependent pharmacokinetics of T-0128 were observed in both kinds of rats. The presence of tumor reduced the plasma half-life and systemic exposure of T-0128. The saturation of hepatic and splenic tissue uptake clearances (CLups), and a large contribution of the tumor CLup to the total body clearance explain these results. Overall, our data provide a rationale for the selection of the carrier for T-0128 and a need for pharmacokinetic studies to evaluate the influences of tumor on the drug disposition.


Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/farmacocinética , Camptotecina/análogos & derivados , Dextranos/administración & dosificación , Dextranos/farmacocinética , Neoplasias Experimentales/metabolismo , Profármacos/administración & dosificación , Profármacos/farmacocinética , Topotecan/análogos & derivados , Topotecan/administración & dosificación , Topotecan/farmacocinética , Animales , Área Bajo la Curva , Secuencia de Carbohidratos , Línea Celular , Cromatografía , Femenino , Semivida , Macrófagos/metabolismo , Datos de Secuencia Molecular , Ratas , Ratas Wistar , Distribución Tisular
18.
Plant Cell Physiol ; 42(1): 85-93, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11158447

RESUMEN

We have described the spatial and temporal accumulation pattern of various cytokinin species in roots, xylem sap and leaves during the resupply of nitrogen in maize. Upon addition of nitrate to nitrogen-depleted maize plants, isopentenyladenosine-5'-monophosphate (iPMP) started to accumulate in roots within 1 h preceding accumulation of trans-zeatin riboside-5'-monophosphate (ZMP), trans-zeatin riboside (ZR) and trans-zeatin (Z). In the xylem flow, both exudation rate of xylem sap and the concentration of the cytokinins increased, and ZR was the dominant species in the sap. In leaf tissue, the accumulation level of Z, which was the dominant form, started to increase 4 h after nitrate resupply to plants and the level was maintained for at least 24 h. Administration of a near physiological concentration of Z, ZR or ZMP (Z-type cytokinins) to detached leaves induced the accumulation of ZmRR1 transcript, that encode maize response regulators, but administration of isopentenyladenine, isopentenyladenosine or iPMP did not. These results strongly suggest that cytokinins are transported across the roots to shoots in response to nitrogen availability, and that, most probably, Z-type cytokinin(s), trigger the induction of ZmRR1.


Asunto(s)
Adenosina Monofosfato/análogos & derivados , Adenosina/análogos & derivados , Aminoimidazol Carboxamida/análogos & derivados , Citocininas/metabolismo , Isopenteniladenosina/análogos & derivados , Nitratos/fisiología , Zea mays/metabolismo , Adenosina/genética , Adenosina/metabolismo , Adenosina Monofosfato/metabolismo , Aminoimidazol Carboxamida/metabolismo , Northern Blotting , Cromatografía Liquida , Ensayo de Inmunoadsorción Enzimática , Regulación de la Expresión Génica de las Plantas , Técnicas In Vitro , Isopenteniladenosina/genética , Isopenteniladenosina/metabolismo , Espectrometría de Masas , Modelos Biológicos , Nitrógeno/fisiología , Hojas de la Planta/metabolismo , Raíces de Plantas/metabolismo , Tallos de la Planta/metabolismo , Ribonucleótidos/metabolismo , Factores de Tiempo , Zea mays/genética , Zeatina/metabolismo
19.
Jpn Heart J ; 42(5): 585-95, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11804300

RESUMEN

We conducted a nested case-control study to evaluate the relationship between antihypertensive agent class and the incidence of initial cardiovascular events. A total of 7.443 patients being treated with an antihypertensive agent in 1985-1986 were enrolled for follow-up of up to 5 years. A total of 362 patients (186 males and 176 females) developed cardiovascular events. Age (5-year interval) and sex-matched controls were then randomly selected. A Multiple logistic regression analysis was done to control for the effects of confounding factors. The results showed that the use of diuretics and beta-blockers was associated with a reduced risk of cardiovascular events (odds ratio [OR] =0.65, 95% confidence interval [CI]: 0.49-0.86, and OR=0.75, 95% CI: 0.56-1.02, respectively), against a significantly raised risk associated with the use of calcium antagonists (OR=1.34, 95% CI: 1.03-1.80). However, as far as stroke was concerned, there was no significant association of risk with the use of any agent. The control group was found to be similar to the case group with respect to the changes in the treatment program during the follow-up period. The results suggest that the calcium antagonists used in Japan during the period of 1985-1990 constituted a potential risk for the occurrence of cardiovascular events.


Asunto(s)
Antihipertensivos/uso terapéutico , Enfermedades Cardiovasculares/epidemiología , Hipertensión/tratamiento farmacológico , Antagonistas Adrenérgicos beta/uso terapéutico , Anciano , Antihipertensivos/clasificación , Bloqueadores de los Canales de Calcio/uso terapéutico , Estudios de Casos y Controles , Diuréticos/uso terapéutico , Femenino , Estudios de Seguimiento , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Factores de Tiempo
20.
Biometals ; 13(3): 241-50, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11127896

RESUMEN

Arsenic in the liver, kidney and muscle of three species of sea turtles, e.g., green turtles (Chelonia mydas), loggerhead turtles (Caretta caretta) and hawksbill turtles (Eretmochelys imbricata), were determined using HG-AAS, followed by arsenic speciation analysis using HPLC-ICP-MS. The order of arsenic concentration in tissues was muscle > kidney > liver. Unexpectedly, the arsenic concentrations in the hawksbill turtles feeding mainly on sponges were higher than the two other turtles primarily eating algae and mollusk which accumulate a large amount of arsenic. Especially, the muscles of the hawksbill turtles contained remarkably high arsenic concentrations averaging 153 mg kg(-1) dry weight with the range of 23.1-205 mg kg(-1) (n = 4), even in comparison with the data from other organisms. The arsenic concentrations in the tissues of the green turtles were significantly decreased with standard carapace length as an indicator of growth. In arsenic compounds, arsenobetaine was mostly detected in the tissues of all the turtles. Besides arsenobetaine, a small amount of dimethylarsinic acid was also observed in the hawksbill turtles.


Asunto(s)
Arsénico/metabolismo , Tortugas/metabolismo , Animales , Arsénico/toxicidad , Arsenicales/análisis , Ácido Cacodílico/análisis , Ácido Cacodílico/metabolismo , Ácido Cacodílico/toxicidad , Cromatografía Líquida de Alta Presión , Femenino , Masculino , Espectrometría de Masas , Especificidad de Órganos , Especificidad de la Especie , Espectrofotometría Atómica , Tortugas/crecimiento & desarrollo
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