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1.
Phys Rev E ; 105(2-2): 025203, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35291161

RESUMEN

We present an experimental method to generate quasiperpendicular supercritical magnetized collisionless shocks. In our experiment, ambient nitrogen (N) plasma is at rest and well magnetized, and it has uniform mass density. The plasma is pushed by laser-driven ablation aluminum (Al) plasma. Streaked optical pyrometry and spatially resolved laser collective Thomson scattering clarify structures of plasma density and temperatures, which are compared with one-dimensional particle-in-cell simulations. It is indicated that just after the laser irradiation, the Al plasma is magnetized by a self-generated Biermann battery field, and the plasma slaps the incident N plasma. The compressed external field in the N plasma reflects N ions, leading to counterstreaming magnetized N flows. Namely, we identify the edge of the reflected N ions. Such interacting plasmas form a magnetized collisionless shock.

2.
Sci Rep ; 12(1): 2346, 2022 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-35173182

RESUMEN

Graphene is known as an atomically thin, transparent, highly electrically and thermally conductive, light-weight, and the strongest 2D material. We investigate disruptive application of graphene as a target of laser-driven ion acceleration. We develop large-area suspended graphene (LSG) and by transferring graphene layer by layer we control the thickness with precision down to a single atomic layer. Direct irradiations of the LSG targets generate MeV protons and carbons from sub-relativistic to relativistic laser intensities from low contrast to high contrast conditions without plasma mirror, evidently showing the durability of graphene.

3.
Lupus ; 28(13): 1577-1582, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31635559

RESUMEN

OBJECTIVE: The objective of this study was to clarify the efficacy and safety of factor Xa inhibitors for antiphospholipid syndrome patients in real world utilization. METHODS: This is a retrospective cohort study comprised of all consecutive patients with antiphospholipid syndrome in our department over a period of 28 years. Patients treated with factor Xa inhibitors were extracted from the cohort. As a control group, patients treated with warfarin were selected from the same cohort with matched age, gender, coexistence of systemic lupus erythematosus, and the presence of antiplatelet therapy, after which we used a propensity score for each of the risk factors as an additional covariate in multivariate Cox proportional hazard regression. The primary endpoint was set as thrombotic and hemorrhagic event-free survival for five years. RESULTS: Among 206 patients with antiphospholipid syndrome, 18 had a history of anti-Xa therapy (five rivaroxaban, 12 edoxaban, one apixaban). Fourteen out of 18 patients on anti-Xa therapy had switched to factor Xa inhibitors from warfarin. Event-free survival was significantly shorter during anti-Xa therapy than that during warfarin therapy (hazard ratio: 12.1, 95% confidence interval: 1.73-248, p = 0.01) ( Figure 1(a) ). Similarly, event-free survival in patients treated with factor Xa inhibitors was significantly shorter compared with controls (hazard ratio: 4.62, 95% confidence interval: 1.54-13.6, p = 0.0075). In the multivariate Cox proportional hazard model, event-free survival in patients with anti-Xa therapy remained significantly shorter (hazard ratio: 11.9, 95% confidence interval: 2.93-56.0, p = 0.0005). CONCLUSIONS: Factor Xa inhibitors may not be recommended for antiphospholipid syndrome.


Asunto(s)
Síndrome Antifosfolípido/tratamiento farmacológico , Inhibidores del Factor Xa/administración & dosificación , Trombosis/prevención & control , Adulto , Síndrome Antifosfolípido/complicaciones , Estudios de Cohortes , Inhibidores del Factor Xa/efectos adversos , Femenino , Hemorragia/inducido químicamente , Humanos , Estudios Longitudinales , Lupus Eritematoso Sistémico/complicaciones , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Trombosis/etiología
4.
Int J Sports Med ; 36(8): 647-53, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25760154

RESUMEN

This study examined the effects of regular post-exercise cold application on muscular and vascular adaptations induced by moderate-intensity resistance training. 14 male subjects participated in resistance training: 5 sets of 8 wrist-flexion exercises at workload of 70-80% of the single repetition maximum, 3 times a week for 6 weeks. 7 subjects immersed their experimental forearms in cold water (10±1°C) for 20 min after wrist-flexion exercises (cooled group), and the other 7 served as control subjects (noncooled group). Measurements were taken before and after the training period; wrist-flexor thickness, brachial-artery diameter, maximal muscle strength, and local muscle endurance were measured in upper extremities. Wrist-flexor thicknesses of the experimental arms increased after training in both groups, but the extent of each increase was significantly less in the cooled group compared with the noncooled group. Maximal muscle strength and brachial-artery diameter did not increase in the cooled group, while they increased in the noncooled group. Local muscle endurance increased in both groups, but the increase in the cooled group tended to be lower compared to the noncooled group. Regular post-exercise cold application to muscles might attenuate muscular and vascular adaptations to resistance training.


Asunto(s)
Adaptación Fisiológica/fisiología , Frío/efectos adversos , Inmersión/efectos adversos , Fuerza Muscular/fisiología , Entrenamiento de Fuerza , Adulto , Antebrazo/fisiología , Voluntarios Sanos , Humanos , Inmersión/fisiopatología , Masculino , Resistencia Física/fisiología , Entrenamiento de Fuerza/métodos
5.
Oncogene ; 33(4): 440-8, 2014 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-23376849

RESUMEN

Intratumoral heterogeneity within individual breast tumors is a well-known phenomenon that may contribute to drug resistance. This heterogeneity is dependent on several factors, such as types of oncogenic drivers and tumor precursor cells. The purpose of our study was to engineer a mouse mammary tumor model with intratumoral heterogeneity by using defined genetic perturbations. To achieve this, we used mice with knockout (-/-) of Ink4a/Arf, a tumor suppressor locus; these mice are known to be susceptible to non-mammary tumors such as fibrosarcoma. To induce mammary tumors, we retrovirally introduced an oncogene, HRAS(G12V), into Ink4a/Arf(-/-) mammary cells in vitro, and those cells were inoculated into syngeneic mice mammary fat pads. We observed 100% tumorigenesis. The tumors formed were negative for estrogen receptor, progesterone receptor and HER2. Further, they had pathological features similar to those of human triple-negative breast cancer (TNBC) (for example, pushing borders, central necrosis). The tumors were found to be heterogeneous and included two subpopulations: CD49f(-) quiescent cells and CD49f(+)cells. Contrary to our expectation, CD49f(-) quiescent cells had high tumor-initiating potential and CD49f(+)cells had relatively low tumor-initiating potential. Gene expression analysis revealed that CD49f(-) quiescent cells overexpressed epithelial-to-mesenchymal transition-driving genes, reminiscent of tumor-initiating cells and claudin-low breast cancer. Our animal model with intratumoral heterogeneity, derived from defined genetic perturbations, allows us to test novel molecular targeted drugs in a setting that mimics the intratumoral heterogeneity of human TNBC.


Asunto(s)
Transformación Celular Neoplásica/genética , Integrina alfa6/metabolismo , Neoplasias Mamarias Experimentales/metabolismo , Células Madre Neoplásicas/metabolismo , Neoplasias de la Mama Triple Negativas/metabolismo , Animales , Transformación Celular Neoplásica/metabolismo , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Femenino , Citometría de Flujo , Inmunohistoquímica , Neoplasias Mamarias Experimentales/genética , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Células Madre Neoplásicas/patología , Análisis de Secuencia por Matrices de Oligonucleótidos , Proteínas Proto-Oncogénicas p21(ras)/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/patología
6.
Phys Rev Lett ; 108(19): 195004, 2012 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-23003052

RESUMEN

We report the experimental results of a turbulent electric field driven by Kelvin-Helmholtz instability associated with laser produced collisionless shock waves. By irradiating an aluminum double plane target with a high-power laser, counterstreaming plasma flows are generated. As the consequence of the two plasma interactions, two shock waves and the contact surface are excited. The shock electric field and transverse modulation of the contact surface are observed by proton radiography. Performing hydrodynamic simulations, we reproduce the time evolutions of the reverse shocks and the transverse modulation driven by Kelvin-Helmholtz instability.

7.
Artículo en Inglés | MEDLINE | ID: mdl-20350843

RESUMEN

Duplication of image regions is a common method for manipulating original images, using typical software like Adobe Photoshop, 3DS MAX, etc. In this study, we propose a duplication detection approach that can adopt two robust features based on discrete wavelet transform (DWT) and kernel principal component analysis (KPCA). Both schemes provide excellent representations of the image data for robust block matching. Multiresolution wavelet coefficients and KPCA-based projected vectors corresponding to image-blocks are arranged into a matrix for lexicographic sorting. Sorted blocks are used for making a list of similar point-pairs and for computing their offset frequencies. Duplicated regions are then segmented by an automatic technique that refines the list of corresponding point-pairs and eliminates the minimum offset-frequency threshold parameter in the usual detection method. A new technique that extends the basic algorithm for detecting Flip and Rotation types of forgeries is also proposed. This method uses global geometric transformation and the labeling technique to indentify the mentioned forgeries. Experiments with a good number of natural images show very promising results, when compared with the conventional PCA-based approach. A quantitative analysis indicate that the wavelet-based feature outperforms PCA- or KPCA-based features in terms of average precision and recall in the noiseless, or uncompressed domain, while KPCA-based feature obtains excellent performance in the additive noise and lossy JPEG compression environments.


Asunto(s)
Algoritmos , Análisis de Ondículas , Humanos , Análisis de Componente Principal , Programas Informáticos
8.
Heredity (Edinb) ; 102(6): 579-89, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19319151

RESUMEN

The Asian black bear (Ursus thibetanus) inhabits two of the main islands, Honshu and Shikoku, in Japan. To determine how climatic oscillations during the Quaternary Era affected the genetic structure of the black bear populations in Japan, we examined their phylogeographic relationships and compared their genetic structure. We analysed an approximately 700-bp sequence in the D-loop region of mitochondrial DNA collected from 589 bears in this study with 108 bears from a previous study. We observed a total of 57 haplotypes and categorized them into three clusters (Eastern, Western and Southern) based on the spatial distribution of the haplotypes. All but 2 of the 41 haplotypes in the Eastern cluster were distributed locally. Genetic diversity was generally low in northern Japan and high in central Japan. Demographic tests rejected the expansion model in northern populations. Haplotypes of the Western and Southern clusters were unique to local populations. We conclude that the extant genetic structure of the Asian black bear populations arose as follows: first, populations became small and genetic drift decreased genetic diversity in the northern area during the last glacial period, whereas large continuous populations existed in the southern part of central Japan. These patterns were essentially maintained until the present time. In western and southern Japan, the effects of climatic oscillations were smaller, and thus, local structure was maintained.


Asunto(s)
Ecosistema , Ursidae/genética , Animales , Clima , ADN Mitocondrial/genética , Variación Genética , Haplotipos , Japón , Filogenia , Ursidae/clasificación
9.
Plant Cell Environ ; 30(11): 1422-35, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17897412

RESUMEN

The glaucocystophyte Cyanophora paradoxa contains cyanelles, plastids with prokaroytic features such as a peptidoglycan wall and a central proteinaceous inclusion body. While this central body includes the majority of the enzyme ribulose 1,5-bisphosphate carboxylase/oxgenase Rubisco), the presence of a carbon-concentrating mechanism (CCM) in C. paradoxa has only been hypothesized. Here, we present physiological data in support of a CCM: CO(2) exchange activity as well as apparent affinity against inorganic carbon were found to increase under CO(2)-limiting stress. Further, expressed sequence tags (ESTs) of C. paradoxa were obtained from two cDNA libraries, one from cells grown in high [CO(2)] conditions and one from cells grown under low [CO(2)] conditions. A cDNA microarray platform assembled from 2378 cDNA sequences revealed that 142 genes significantly responded to a shift from high to low [CO(2)]. Trends in gene expression were comparable to those reported for Chlamydomonas reinhardtii and the cyanobacterium Synechocystis 6803, both possessing a CCM. Among genes regulated by [CO(2)], transcripts were identified encoding carbonic anhydrases (CAs), Rubisco activase and a putative bicarbonate transporter in C. paradoxa, likely functionally involved in the CCM. These results and the polyhedric appearance of the central body further support the hypothesis of a unique 'eukaryotic carboxysome' in Cyanophora.


Asunto(s)
Aclimatación/fisiología , Dióxido de Carbono/metabolismo , Carbono/metabolismo , Cyanophora/metabolismo , Células Cultivadas , Cyanophora/citología , Etiquetas de Secuencia Expresada , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/fisiología , Biblioteca de Genes
10.
Int J Pharm ; 270(1-2): 55-64, 2004 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-14726122

RESUMEN

The in vitro release profiles and the bleeding phenomenon of Tacrolimus and propylene carbonate (PC) as a dispersing solvent for Tacrolimus drug substance in Tacrolimus ointment were investigated when changing concentrations of Tacrolimus and PC in the ointment were used, respectively. The bleeding test result indicated that Tacrolimus was in equilibrium between inside and outside of PC droplets in intact ointment base. A cumulative release amount of Tacrolimus from ointment, plotted against the square root of time, showed a straight line initially with a slope of q1 followed to change a slope to be q2 at a certain time, where the relation of these slopes being q1

Asunto(s)
Inmunosupresores/química , Propano/análogos & derivados , Tacrolimus/química , Química Farmacéutica , Inmunosupresores/administración & dosificación , Pomadas , Propano/química , Solventes/química , Tacrolimus/administración & dosificación , Termodinámica
11.
Gut ; 52(10): 1487-93, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12970143

RESUMEN

BACKGROUND AND AIM: The present study was conducted to examine the effect of activin A on activation of rat pancreatic stellate cells (PSCs). METHODS: PSCs were prepared from rat pancreas using collagenase digestion and centrifugation with Nycodenz gradient. Activation of PSCs was examined by determining smooth muscle actin expression with western blotting. The presence of activin A receptors in PSCs was investigated by reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and immunocytochemistry. Expression of activin A and transforming growth factor beta (TGF-beta) mRNA was examined by RT-PCR. Activin A and TGF-beta peptide concentrations were examined with ELISA. Existence of activin A peptide in PSCs was investigated by immunocytochemistry. Collagen secretion was determined by Sirius red dye binding. RESULTS: Activin A receptors I and IIa were present in PSCs. PSCs expressed activin A mRNA and secreted activin A. Activin A enhanced PSC activation and collagen secretion in a dose dependent manner. TGF-beta and activin A increased each other's secretion and mRNA expression of PSCs. Follistatin decreased TGF-beta mRNA expression and TGF-beta secretion of PSCs, and inhibited both PSC activation and collagen secretion. CONCLUSION: Activin A is an autocrine activator of PSCs. Follistatin can inhibit PSC activation and collagen secretion by blocking autocrined activin A and decreasing TGF-beta expression and secretion of PSCs.


Asunto(s)
Activinas/farmacología , Comunicación Autocrina , Folistatina/farmacología , Subunidades beta de Inhibinas/farmacología , Páncreas/efectos de los fármacos , Proteínas , Actinas/análisis , Receptores de Activinas Tipo I/análisis , Receptores de Activinas Tipo I/genética , Receptores de Activinas Tipo II/análisis , Receptores de Activinas Tipo II/genética , Activinas/análisis , Activinas/metabolismo , Animales , Western Blotting/métodos , Células Cultivadas , Colágeno/metabolismo , Relación Dosis-Respuesta a Droga , Fibrosis , Folistatina/uso terapéutico , Subunidades beta de Inhibinas/análisis , Subunidades beta de Inhibinas/metabolismo , Microscopía Fluorescente , Páncreas/química , Páncreas/metabolismo , ARN Mensajero/análisis , Ratas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Crecimiento Transformador beta/análisis , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/farmacología
12.
Appl Microbiol Biotechnol ; 62(5-6): 478-83, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12750854

RESUMEN

Biotinylated thermo-responsive magnetic nanoparticles for use in affinity selection from yeast cell surface display libraries were prepared by coating magnetite nanoparticles with a thermo-responsive polymer consisting of N-isopropyl acrylamide and a biotin derivative. These particles showed a reversible transition between flocculation and dispersion at around the lower critical solution temperature of 30 degrees C, above which the flocculated particles--which absorbed a large amount of avidin due to their large surface area--were quickly separable by magnet. The model library was constructed by mixing control yeast cells with target yeast cells co-displaying IgG binding protein (ZZ) and enhanced green fluorescence protein. Biotinylated IgG and avidin were subsequently added to the model library, and target cells were efficiently enriched with the biotinylated magnetic nanoparticles by avidin-biotin sandwich and ZZ-IgG interaction. The few target cells (0.001%) in the model library were enriched by up to 100% in only 5 days by an affinity selection procedure repeated four times. This novel method based on magnetic nanoparticles and a yeast cell surface display system could fulfill a wide range of applications in the analysis of protein-protein interactions and rapid isolation of novel biomolecules.


Asunto(s)
Membrana Celular/metabolismo , Separación Inmunomagnética/métodos , Proteínas/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Saccharomyces cerevisiae/metabolismo , Avidina/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Biotinilación , Membrana Celular/genética , Floculación , Proteínas Fluorescentes Verdes , Fragmentos Fc de Inmunoglobulinas/metabolismo , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Lectinas de Unión a Manosa , Microesferas , Nanotecnología , Biblioteca de Péptidos , Proteínas/química , Proteínas/aislamiento & purificación , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/aislamiento & purificación , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/aislamiento & purificación , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Suspensiones , Temperatura
14.
Gene Ther ; 9(4): 303-6, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11896470

RESUMEN

To achieve high transgene expression in the liver, we have compared the reporter gene expression among various murine retroviral long terminal repeats (LTRs) or leader sequences in vitro. Transient reporter gene expression assays revealed the highest gene expression by the polycythemic strain of spleen focus-forming virus (SFFVp) LTR in differentiated hepatocellular carcinoma cell lines, HuH-7 and PLC/PRF/5. However, remarkable difference was not observed among LTRs in other types of human liver tumor cell lines. Essentially the same results were obtained by infecting these cells with a series of retroviral vectors. Repression of transgene expression was observed by the leader sequences from Moloney murine leukemia virus (MoMLV), but not from mouse embryonic stem cell virus (MESV). Strengths of the promoters were further compared in murine hepatocytes in vivo. Although the proportions of genomic integration were almost the same, higher gene expression was observed by the FMEV-type vector, which contained the SFFVp LTR and the MESV leader, in comparison with that by the MoMLV-based vector. Thus, FMEV-type vectors may represent a novel type of vectors for human gene therapy with hepatocytes.


Asunto(s)
Vectores Genéticos , Hepatocitos/metabolismo , Retroviridae/genética , Transgenes , Animales , Expresión Génica , Genes Reporteros , Humanos , Ratones , Virus Inductores de Focos en Células del Visón/genética , Virus de la Leucemia Murina de Moloney/genética , Virus Formadores de Foco en el Bazo/genética , Secuencias Repetidas Terminales/genética , Células Tumorales Cultivadas
15.
Heart ; 87(2): 136-9, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11796551

RESUMEN

OBJECTIVE: To investigate factors predicting the development of outward remodelling of the carotid artery in patients with atherosclerosis. DESIGN: 130 patients with carotid artery stenosis (15-85% of the vessel diameter) were divided into two groups, based on the presence or absence of outward remodelling of the sclerotic carotid segment on high resolution ultrasonography. Logistic regression analysis was used to evaluate the contribution of haemodynamic, laboratory, and clinical measurements on the development of remodelling, including age, sex, type of stenosis, extent of plaque, per cent diameter stenosis, underlying disease, selected drug treatment, and plasma concentrations of total cholesterol, high density lipoprotein cholesterol, triglyceride, and uric acid. RESULTS: 64 patients (49%) had outward remodelling. Multivariate regression analysis showed that hypertension, the type of plaque, the thickness of the plaque, and the extent of stenosis were independent factors predicting remodelling. The odds ratios of hypertension, unstable shape of plaque, thickness of plaque, and the extent of the stenosis were 6.70, 3.02, 2.04, and 1.05, respectively. Other measurements did not contribute significantly to the estimation of remodelling. CONCLUSIONS: Compensatory enlargement of the vessel occurs in about 50% of carotid artery segments with a diameter stenosis of 15-85%. Hypertension and the shape of the plaque are major determinants of the development of outward remodelling.


Asunto(s)
Arteriosclerosis/patología , Estenosis Carotídea/patología , Anciano , Arteriosclerosis/diagnóstico por imagen , Arteria Carótida Común , Estenosis Carotídea/diagnóstico por imagen , Femenino , Humanos , Hipertensión/complicaciones , Hipertensión/patología , Masculino , Análisis de Regresión , Reproducibilidad de los Resultados , Ultrasonografía
16.
IEEE Trans Neural Netw ; 13(4): 888-93, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-18244484

RESUMEN

In this paper, we develop a system for enhancement of the speech signal with highest energy from a linear convolutive mixture of n statistically independent sound sources recorded by m microphones, where m

17.
Biopharm Drug Dispos ; 22(1): 31-9, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11745905

RESUMEN

We investigated the pharmacokinetics of diclofenac, one of the important analgesics in palliative care, after its intrarectal and intracolostomal administration to rabbits with rectal resection or colostoma construction. In rectal-resected rabbits, its bioavailability after rectal administration was significantly lower than that in normal rabbits, and furthermore that after intracolostomal administration was significantly lower than that in rectal-resected rabbits. This decreased bioavailability in rabbits with rectal resection and colostoma construction was thought to be due to the increased first-pass effect. With increase in the dose up to 1.5-fold, the plasma concentrations in both rectal-resected and colostoma-constructed rabbits increased to the normal rabbit level. These results indicate that the bioavailability of diclofenac sodium after its rectal and intracolostomal administration decreases, and that an increased dose can restore the decreased plasma concentration. There was no difference in the plasma concentration with diclofenac sodium suppositories between administration into the normal rectum and the remaining rectum following colostoma construction, and the remaining rectum was found to be a useful administration route for suppositories. Therefore, it was indicated that when administering diclofenac sodium suppositories to rectal-resected and colostoma-constructed patients, the dose should be increased, because the pharmacokinetics of diclofenac was similar in rabbits and human.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacocinética , Colostomía , Diclofenaco/farmacocinética , Recto/metabolismo , Recto/cirugía , Administración Oral , Administración Rectal , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/sangre , Disponibilidad Biológica , Diclofenaco/administración & dosificación , Diclofenaco/sangre , Inyecciones Intravenosas , Masculino , Conejos , Recto/efectos de los fármacos
18.
Eur J Drug Metab Pharmacokinet ; 26(1-2): 129-35, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11554427

RESUMEN

The possibility of pharmacokinetic interactions between Saiko-ka-ryukotsu-borei-to extract powder (TJ-12), a widely used traditional Chinese herbal (Kampo) medicine, and carbamazepine (CBZ), an important anti-epileptic drug, was examined in rats. There were no significant differences in the serum protein binding of CBZ and carbamazepine- 10,11-epoxide (CBZ-E), its active metabolite, at two concentrations (1 and 10 Bg/ml) between twogroups pretreated orally with the vehicle andTJ-12 suspension (1 g/kg/d, p.o.) for 1 week. One-week repeated pretreatment with TJ- 12 (1 g/kg/d) did not influence liver weight, contents of cytochromes P450 and b5 in hepatic microsomes or the formation rate of CBZ-E from CBZ by its microsomes, while pretreatment with phenobarbital (80 mg/kg/d, i.p.) significantly increased these parameters. Neither a single nor 1-week repeated oral pretreatment with TJ-12 (1 g/kg/d) affected the plasma concentration-time profile and any pharmacokinetic parameter of CBZ or CBZ-E after oral administration of CBZ (50 mg/kg). These results indicated that oral co-administration of TJ-12 with CBZ has no effect ofthe pharmacokinetics of CBZ or CBZ-E in rats. Concomitant treatment with TJ- 12 and CBZ appears to be pharmacokinetically safe in humans.


Asunto(s)
Anticonvulsivantes/farmacología , Anticonvulsivantes/farmacocinética , Carbamazepina/farmacología , Carbamazepina/farmacocinética , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/farmacocinética , Animales , Biotransformación , Proteínas Sanguíneas/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Interacciones Farmacológicas , Femenino , Interacciones de Hierba-Droga , Técnicas In Vitro , Hígado/efectos de los fármacos , Hígado/enzimología , Masculino , Medicina Kampo , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/enzimología , Unión Proteica , Ratas , Ratas Wistar
19.
IEEE Trans Biomed Eng ; 48(8): 850-5, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11499522

RESUMEN

Our study focuses on a new method of estimating the heart rate variability (HRV) which does not require the use of electrocardiogram (ECG) R-wave detection. Contrary to the R-wave detection method which requires a sampling frequency higher than 100 Hz, the one proposed here can be used to calculate the HRV from an ECG signal sampled at a frequency of approximately 5 Hz with a relative mean error of 0.03. This new method is based on extracting the instantaneous fundamental frequency from the ECG. The method could be efficiently used to extract the HRV from an ECG measured for healthy subjects performing an exercise in which the HRV increases linearly with time, and for subjects with respiratory and cardiac problems. The overall error decreased as we low-pass filtered the HRV with lower cut-off frequencies. Moreover, it was shown that the method could be efficiently used to calculate the HRV from blood pressure measurements and to be robust to noise.


Asunto(s)
Electrocardiografía/métodos , Frecuencia Cardíaca/fisiología , Algoritmos , Arritmias Cardíacas/fisiopatología , Presión Sanguínea/fisiología , Humanos , Esfuerzo Físico/fisiología , Procesamiento de Señales Asistido por Computador , Síndromes de la Apnea del Sueño/fisiopatología
20.
J Biol Chem ; 276(36): 33798-804, 2001 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-11451956

RESUMEN

PsbT is a small chloroplast-encoded hydrophobic polypeptide associated with the photosystem II (PSII) core complex. A psbT-deficient mutant (Delta psbT) of the green alga Chlamydomonas reinhardtii grows photoautotrophically, whereas its growth is significantly impaired in strong light. To understand the photosensitivity of Delta psbT, we have studied the effect of strong illumination on PSII activity and proteins. It is shown that the level of PSII activity and proteins is reduced in the Delta psbT more significantly than in wild type under strong light. When recovery of the photodamaged PSII is inhibited by a chloroplast protein synthesis inhibitor, the light-induced inactivation and degradation of PSII occur similarly in wild-type and mutant cells. On the contrary, the recovery of PSII activity after partial photoinactivation is remarkably delayed in the Delta psbT cells, suggesting that PsbT is required for efficient recovery of the photodamaged PSII complex. These results therefore present the first evidence for involvement of this small PSII polypeptide in the recovery process. Partial disintegration of the purified PSII core complex and localization of PSII proteins in the resulting PSII subcore complexes have revealed that PsbT is associated with D1/D2 heterodimer. A possible role of PsbT in the recovery process is discussed.


Asunto(s)
Chlamydomonas reinhardtii/química , Proteínas del Complejo del Centro de Reacción Fotosintética/metabolismo , Complejo de Proteína del Fotosistema II , Animales , Western Blotting , División Celular , Cloroplastos/metabolismo , Reparación del ADN , Cinética , Luz , Mutación , Oxígeno/metabolismo , Fotosíntesis , Unión Proteica , Factores de Tiempo
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