Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
1.
Dig Dis Sci ; 69(3): 969-977, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38300418

RESUMO

OBJECTIVES: In patients with unresectable malignant hilar biliary obstruction (UMHBO), drainage of ≥ 50% liver volume correlates with better clinical outcomes. Accurately measuring the liver volume to be drained by biliary stents is required. We aimed to develop a novel method for calculating the drained liver volume (DLV) using a 3D volume analyzer (3D volumetry), and assess the usefulness for drainage in patients with UMHBO. METHODS: Three-dimensional volumetry comprises the following steps: (1) manual tracing of bile duct using 3D imaging system; (2) 3D reconstruction of bile duct and liver parenchyma; and (3) calculating DLV according to the 3D distribution of bile ducts. Using 3D volumetry, we reviewed data of patients who underwent biliary drainage for UMHBO, calculated the DLV, and determined the association between DLV and biliary drainage outcome. RESULTS: There were 104 eligible cases. The mean DLV was 708 ± 393 ml (53% ± 21%). and 65 patients (63%) underwent drainage of ≥50% liver volume. The clinical success rate was significantly higher in patients with DLV ≥ 50% than in patients with DLV < 50% (89% vs. 28%, P < 0.001). The median time to recurrence of biliary obstruction (TRBO) and survival time were significantly longer in patients with DLV ≥ 50% than in patients with DLV < 50% (TRBO, 292 vs. 119 days, P = 0.03; survival, 285 vs. 65days, P = 0.004, log-rank test, respectively). CONCLUSIONS: Three-dimensional volumetry, a novel method to calculate DLV accurately according to bile duct distribution was useful for drainage in UMHBO patients.


Assuntos
Neoplasias dos Ductos Biliares , Colestase , Humanos , Neoplasias dos Ductos Biliares/complicações , Neoplasias dos Ductos Biliares/diagnóstico por imagem , Neoplasias dos Ductos Biliares/patologia , Fígado/diagnóstico por imagem , Fígado/patologia , Colestase/diagnóstico por imagem , Colestase/etiologia , Colestase/cirurgia , Ductos Biliares/patologia , Stents , Drenagem/métodos , Resultado do Tratamento
2.
Nihon Shokakibyo Gakkai Zasshi ; 121(4): 321-329, 2024.
Artigo em Japonês | MEDLINE | ID: mdl-38599843

RESUMO

A 76-year-old woman with a suspected double extrahepatic bile duct was referred to our hospital. MRCP revealed that the left hepatic and posterior ducts combined to form the ventral bile duct and that the anterior duct formed the dorsal bile duct. ERCP demonstrated that the ventral bile duct was linked with the Wirsung duct. Amylase levels in the bile were unusually high. Based on these findings, we diagnosed a double extrahepatic bile duct with pancreaticobiliary maljunction and choledocholithiasis. Duplicate bile duct resection and bile duct jejunal anastomosis were performed considering the risk of biliary cancer due to pancreaticobiliary maljunction. The resected bile duct epithelium demonstrated no atypia or hyperplastic changes.


Assuntos
Ductos Biliares Extra-Hepáticos , Procedimentos Cirúrgicos do Sistema Biliar , Má Junção Pancreaticobiliar , Feminino , Humanos , Idoso , Má Junção Pancreaticobiliar/cirurgia , Ductos Biliares Extra-Hepáticos/diagnóstico por imagem , Ductos Biliares Extra-Hepáticos/cirurgia , Ductos Pancreáticos/diagnóstico por imagem , Ductos Pancreáticos/cirurgia , Ductos Biliares/diagnóstico por imagem , Ductos Biliares/cirurgia , Bile
3.
Mol Cell Biochem ; 435(1-2): 97-108, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28534121

RESUMO

Tetrahydrobiopterin (BH4) is a common coenzyme of phenylalanine-, tyrosine-, and tryptophan hydroxylases, alkylglycerol monooxygenase, and NO synthases (NOS). Synthetic BH4 is used medicinally for BH4-responsive phenylketonuria and inherited BH4 deficiency. BH4 supplementation has also drawn attention as a therapy for various NOS-related cardio-vascular diseases, but its use has met with limited success in decreasing BH2, the oxidized form of BH4. An increase in the BH2/BH4 ratio leads to NOS dysfunction. Previous studies revealed that BH4 supplementation caused a rapid urinary loss of BH4 accompanied by an increase in the blood BH2/BH4 ratio and an involvement of probenecid-sensitive but unknown transporters was strongly suggested in these processes. Here we show that OAT1 and OAT3 enabled cells to take up BP (BH4 and/or BH2) in a probenecid-sensitive manner using rat kidney slices and transporter-expressing cell systems, LLC-PK1 cells and Xenopus oocytes. Both OAT1 and OAT3 preferred BH2 and sepiapterin as their substrate roughly 5- to 10-fold more than BH4. Administration of probenecid acutely reduced the urinary exclusion of endogenous BP accompanied by a rise in blood BP in vivo. These results indicated that OAT1 and OAT3 played crucial roles: (1) in determining baseline levels of blood BP by excluding endogenous BP through the urine, (2) in the rapid distribution to organs of exogenous BH4 and the exclusion to urine of a BH4 excess, particularly when BH4 was administered, and (3) in scavenging blood BH2 by cellular uptake as the gateway to the salvage pathway of BH4, which reduces BH2 back to BH4.


Assuntos
Biopterinas/análogos & derivados , Proteína 1 Transportadora de Ânions Orgânicos/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Transporte Biológico Ativo/fisiologia , Biopterinas/genética , Biopterinas/metabolismo , Linhagem Celular , Oócitos , Proteína 1 Transportadora de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos Sódio-Independentes/genética , Probenecid/farmacologia , Ratos , Ratos Sprague-Dawley , Xenopus
4.
J Appl Biomech ; 33(2): 166-170, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27834549

RESUMO

This study examined isometric strength (maximal voluntary contraction [MVC]) and endurance of cervical flexor and extensor muscles in healthy individuals at the craniocervical (CC) and cervicothoracic (CT) axes. MVC and endurance measures (time to task failure in seconds [s]) at 50% MVC were recorded in 4 directions (CC flexion, CC extension, CT flexion, and CT extension) in 20 males and 20 females, and 6 strength and endurance ratios were calculated. The findings showed that the cervical extensor muscles are not only much stronger than the flexors (1.3-2 times greater MVC), but also have greater capacity for endurance (2-2.4 times greater). While males produced significantly greater MVC recordings than females (P < .003), strength ratios (P > .06) and endurance measures (P > .11) were similar. Endurance ratios were also similar except the CT extension to CC flexion ratio, which was significantly larger in females compared with males (P = .03). These findings demonstrate that substantial but normal variation exists in strength and endurance parameters between cervical flexor and extensor muscles. This is informative to clinicians when evaluating the performance of these neck muscles or when deciding on exercise parameters (eg, load, duration) when training their performance.


Assuntos
Músculos do Dorso/fisiologia , Contração Muscular/fisiologia , Força Muscular/fisiologia , Músculos do Pescoço/fisiologia , Resistência Física/fisiologia , Adulto , Vértebras Cervicais/fisiologia , Feminino , Humanos , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Vértebras Torácicas/fisiologia
5.
J Org Chem ; 81(2): 433-41, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26652502

RESUMO

Trifluoromethylphenyl-substituted phthalimide derivatives favorably form triboluminescence (TL) active noncentrosymmetric crystals. Oligothienyl-, oligophenyl-, and naphthyl-substituted phthalimide derivatives were successfully developed as a series of metal free TL compounds. X-ray crystal structure analyses of bithienyl and naphthyl derivatives revealed noncentrosymmetric layer structures in the same direction. Introduction of suitable electron rich π-units such as thienyl groups enhances their photoluminescence and TL characteristics, and the colors can be also controlled in the visible region. A rigid naphthyl-substituted imide derivative exhibits extremely high TL performance.

6.
Chemistry ; 20(36): 11318-21, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25048397

RESUMO

A novel method for the fabrication of a charge-transfer complex crystal was developed. Photoirradiation of a solution of TPP[Co(tbp)(CN)(2)] and TPP[Co(Pc)(CN)(2)] (tbp=tetrabenzoporphyrin, Pc=phthalocyanine, TPP=tetraphenylphosphonium) gave a molecular conducting crystal of a charge-transfer complex TPP[Co(tbp)(CN)(2)](2), which was produced by the process in which the photoexcited electron in tbp was transferred from the LUMO of tbp to that of Pc.

7.
Diagnostics (Basel) ; 14(6)2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38535071

RESUMO

This study aimed to develop and validate a simple scoring system to determine the high-risk group for pancreatic cancer (PC) in the asymptomatic general population. The scoring system was developed using data from PC cases and randomly selected non-PC cases undergoing annual medical checkups between 2008 and 2013. The performance of this score was validated for participants with medical checkups between 2014 and 2016. In the development set, 45 PC cases were diagnosed and 450 non-PC cases were identified. Multivariate analysis showed three changes in clinical data from 1 year before diagnosis as independent risk factors: ΔHbA1c ≥ 0.3%, ΔBMI ≤ -0.5, and ΔLDL ≤ -20 mg/dL. A simple scoring system, incorporating variables and abdominal ultrasound findings, was developed. In the validation set, 36 PC cases were diagnosed over a 3-year period from 32,877 participants. The AUROC curve of the scoring system was 0.925 (95%CI 0.877-0.973). The positive score of early-stage PC cases, including Stage 0 and I cases, was significantly higher than that of non-PC cases (80% vs. 6%, p = 0.001). The simple scoring system effectively narrows down high-risk PC cases in the general population and provides a reasonable approach for early detection of PC.

8.
Blood ; 117(9): 2640-8, 2011 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-21220748

RESUMO

Dendritic cells (DCs) are known to regulate immune responses by inducing both central and peripheral tolerance. DCs play a vital role in negative selection of developing thymocytes by deleting T cells with high-affinity for self-peptide-major histocompatibility complexes. In the periphery, DCs mediate peripheral tolerance by promoting regulatory T-cell development, induction of T-cell unresponsiveness, and deletion of activated T cells. We studied whether allogeneic DCs, obtained from bone marrow cultured with either Flt3L (FLDCs) or granulocyte-macrophage colony-stimulating factor (GMDCs), could induce allospecific central and peripheral tolerance after IV injection; B cells were used as a control. The results showed that only FLDCs reached the thymus after injection and that these cells induced both central and peripheral tolerance to donor major histocompatibility complexes. For central tolerance, injection of FLDCs induced antigen-specific clonal deletion of both CD8 and CD4 single-positive thymocytes. For peripheral tolerance, injection of FLDCs induced donor-specific T-cell unresponsiveness and prolonged survival of donor-derived skin grafts. Tolerance induction by adoptive transfer of FLDCs could be a useful approach for promoting graft acceptance after organ transplantation.


Assuntos
Células Dendríticas/citologia , Células Dendríticas/imunologia , Sobrevivência de Enxerto/imunologia , Tolerância Imunológica/imunologia , Transplante de Pele/imunologia , Transferência Adotiva , Animais , Movimento Celular , Proliferação de Células , Células Clonais , Epitopos/imunologia , Injeções , Proteínas de Membrana/metabolismo , Camundongos , Células da Side Population/citologia , Células da Side Population/imunologia , Linfócitos T/citologia , Linfócitos T/imunologia , Timo/citologia , Fatores de Tempo , Transplante Homólogo
9.
ACS Appl Mater Interfaces ; 15(38): 45137-45145, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37702224

RESUMO

Biomimetic visual sensors utilizing bacteriorhodopsin (bR) were fabricated by using an inkjet method. The inkjet printer facilitated the jetting of the bR suspension, allowing for the deposition of bR films. The resulting inkjet-printed bR film exhibited time-differential photocurrent response characteristics similar to those of a dip-coated bR film. By adjusting the number of printed bR film layers, the intensity of the photocurrent could be easily controlled. Moreover, the inkjet printing technique enabled unconstrained patterning, facilitating the design of various visual information processing functions, such as visual filters. In this study, we successfully fabricated two visual filters, namely, a two-dimensional Difference of Gaussian (DOG) filter and a Gabor filter. The printed DOG filter demonstrated edge detection capabilities corresponding to contour recognition in visual receptive fields. On the other hand, the printed Gabor filter proved effective in detecting objects of specific sizes as well as their motion and orientation. The integration of bR and the inkjet method holds significant potential for the widespread implementation of highly functional biomaterial-based visual sensors. These sensors have the capability to provide real-time visual information while operating in an energy-efficient manner.

10.
Mol Genet Metab ; 105(4): 575-81, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22318121

RESUMO

Tetrahydrobiopterin (BH(4)) is an essential cofactor of aromatic amino acid hydroxylases and NO synthase. Supplementation of BH(4) potentially targets cardiovascular dysfunction as well as inherited BH(4) deficiencies and BH(4)-responsive phenylketonuria. However, the high cost/effect ratio of the recommended daily dose of BH(4) supplementation acts against further popularization of this therapy. The aim of this study was to attenuate urinary excretion with the intention of improving efficacy of BH(4) supplementation. The rapid excretion of BH(4) in the urine was confirmed to be the major route of supplemented BH(4) loss. In addition to glomerular filtration into the urine, a dominant rapid exclusion by renal secretion was observed in rats (T((1/2))=16 min) when the plasma BH(4) was higher than about 1 nmol/mL (more than 10 times higher than normal), due to BH(4) supplementation. The rapidity of the process was slowed by prior administration of cyclosporin A, a representative anti-excretory drug, and the excretion decelerated to a moderate rate (T((1/2))=53 min). By the combined administration of BH(4) plus cyclosporin A, the blood BH(4) levels were dramatically elevated. It was hypothesized that the drug interfered with kidney excretion of BH(4) rather than by attenuating organ tissue distribution by inhibiting biopterin uptake from the plasma. Consistent with this hypothesis, biopterin levels after BH(4) administration were elevated in major organs in the presence of anti-excretory drugs without notable change in their BH(4) fraction which was consistently 95% or higher regardless of combined administration with the drugs. Targeting these putative transporters would be a promising approach for improving the efficiency of BH(4) supplementation therapy.


Assuntos
Biopterinas/análogos & derivados , Biopterinas/sangue , Biopterinas/urina , Suplementos Nutricionais , Rim/fisiopatologia , Fenilcetonúrias/metabolismo , Animais , Biopterinas/administração & dosagem , Biopterinas/metabolismo , Taxa de Filtração Glomerular , Cinética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fenilcetonúrias/tratamento farmacológico , Ratos , Ratos Sprague-Dawley
11.
J Org Chem ; 77(5): 2159-68, 2012 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-22288831

RESUMO

Incorporation reactions of carbon dioxide (CO(2)) with N-Boc-α-amido and α-acetoxy stannanes were developed using CsF as a mild tin activator. Monoprotected α-amido stannanes could be used, and the corresponding arylglycine derivatives were obtained in moderate-to-high yields under 1 MPa (10 atm) of CO(2) pressure. α-Acetoxy stannanes also underwent carboxylation to afford mandelic acid derivatives in excellent yields under ambient CO(2) pressure. Both transformations enabled the synthesis of α-tertiary and α-quaternary carboxylic acid derivatives. In addition, the chirality of (S)-N-tert-butylsulfonyl-α-amido stannanes was transferred with up to 90% inversion of configuration at 100 °C.


Assuntos
Dióxido de Carbono/química , Glicina/síntese química , Ácidos Mandélicos/síntese química , Compostos de Estanho/química , Glicina/análogos & derivados , Glicina/química , Ácidos Mandélicos/química , Estrutura Molecular , Estereoisomerismo
12.
Polymers (Basel) ; 14(19)2022 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-36236093

RESUMO

In this paper, the structure and properties of transparent films composed of bisphenol-A polycarbonate (PC) and a commercially available copolyester, poly(1,4-cyclohexanedimethanol-co-2,2,4,4-tetramethyl-1,3-cyclobutanediol-co-terephthalate) (CPE), were studied. Both PC and CPE films are known to be transparent with good mechanical toughness. It was found that PC/CPE (50/50) showed miscibility in both the molten and solid states, indicating that there is a high possibility for the blend system to be miscible in the whole blend ratios. Because of the miscibility, the blend films showed no light scattering originating from phase separation. The mechanical properties of the films, such as Young's modulus, yield stress, and strain at break, were determined by the blend ratio, and the glass transition temperature increased with the PC content, which corresponded well with the values predicted by the Fox equation. These results demonstrate that the thermal and mechanical properties of the films can only be controlled by the blend ratio. Since these transparent films showed excellent mechanical toughness irrespective of the blend ratios, they can be employed in various applications.

13.
J Clin Med ; 11(14)2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35887953

RESUMO

The diagnosis of autoimmune pancreatitis (AIP) and immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) may require a somewhat invasive pathological examination and steroid responsiveness. This retrospective study assessed the complemental diagnosis of AIP and IgG4-SC using submandibular gland (SG) ultrasonography (US) in 69 patients, including 54 patients with AIP, 2 patients with IgG4-SC, and 13 patients with both AIP and IgG4-SC. The data from the physical examination and US of SGs to diagnose AIP (n = 67) and IgG4-SC (n = 15) were analyzed. The steroid therapy efficacy in resolving hypoechoic lesions in SGs was evaluated in 36 cases. The presence of IgG4-related pancreaticobiliary disease with multiple hypoechoic lesions in SGs was reduced from 31 to 11 cases after steroid therapy, suggesting that multiple hypoechoic lesions in SGs are strongly associated with IgG4-positive cell infiltrations. Multiple hypoechoic lesions in SGs were observed in 53 cases, whereas submandibular swelling on palpation was observed in 21 cases of IgG4-related pancreaticobiliary diseases. A complemental diagnosis of IgG4-related pancreaticobiliary diseases without a histological diagnosis and steroid therapy was achieved in 57 and 68 cases without and with multiple hypoechoic lesions in SGs, respectively. In conclusion, multiple hypoechoic lesions in SGs are useful for the complemental diagnosis of IgG4-related pancreaticobiliary diseases.

14.
Mol Genet Metab ; 104(3): 404-6, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21704545

RESUMO

Rat aortic endothelial cells were cultured on a porous membrane to form a monolayer sheet. They efficiently accumulated tetrahydrobiopterin (BH(4)) by uptake of sepiapterin but did so only moderately by uptake of dihydrobiopterin. The endothelial cell sheet preferentially took up the pterins from the apical side. Accordingly, a dense accumulation of ENT2-like immunoreactivity was visualized on the apical surface of the cell sheet. The findings suggest that vascular endothelial cells receive BH(4) precursors directly from the blood stream rather than from ablumenal tissues.


Assuntos
Aorta/citologia , Biopterinas/análogos & derivados , Células Endoteliais/metabolismo , Pterinas/metabolismo , Animais , Aorta/metabolismo , Biopterinas/biossíntese , Biopterinas/metabolismo , Óxido Nítrico/biossíntese , Ratos
15.
Mol Genet Metab ; 102(1): 18-28, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20956085

RESUMO

Tetrahydrobiopterin (BH(4)) is synthesized de novo in particular cells, but in the case of a systemic or local BH(4) deficiency, BH(4) supplementation therapy is applied. BH(4)-responsive PKU has also been effectively treated with BH(4) supplementation. However, the rapid clearance of the supplemented BH(4) has prevented the therapy from being widely accepted. Deposition of BH(4) after supplementation involves oxidation of BH(4) to dihydrobiopterin (BH(2)) and subsequent conversion to BH(4) by the salvage pathway. This pathway is known to be almost ubiquitous in the body. However, the mechanism for the redistribution and exclusion of BH(4) across the plasma membrane remains unclear. The aim of this work was to search for the key transporter of the uptake precursor of the salvage pathway. Based on the observed sensitivity of pterin transport to nitrobenzylthioinosine (NBMPR), we examined the ability of ENT1 and ENT2, representative equilibrative nucleoside transporters, to transport sepiapterin (SP), BH(2) or BH(4) using HeLa cell and Xenopus oocyte expression systems. hENT2 was capable of transporting the pterins with an efficiency of SP>BH(2)>BH(4). hENT1 could also transport the pterins but less efficiently. Non-transfected HeLa cells and rat aortic endothelial cells were able to incorporate the pterins and accumulate BH(4) via uptake that is likely mediated by ENT2 (SP>BH(2)>BH(4)). When exogenous BH(2) was given to mice, it was efficiently converted to BH(4) and its tissue deposition was similar to that of sepiapterin as reported (Sawabe et al., 2004). BH(4) deposition after BH(2) administration was influenced by prior treatment with NBMPR, suggesting that the distribution of the administered BH(2) was largely mediated by ENT2, although urinary excretion appeared to be managed by other mechanisms. The molecular basis of the transport of SP, BH(2), and BH(4) across the plasma membrane has now been described for the first time: ENT2 is a transporter of these pterins and is a plausible gateway to the salvage pathway of BH(4) biosynthesis, at least under conditions of exogenous pterin supplementation. The significance of the gateway was discussed in terms of BH(2) uptake for BH(4) accumulation and the release for modifying the intracellular BH(2)/BH(4) ratio.


Assuntos
Biopterinas/análogos & derivados , Proteínas de Transporte de Nucleosídeo Equilibrativas/biossíntese , Pterinas/metabolismo , Proteínas Recombinantes/metabolismo , Animais , Biopterinas/metabolismo , Biopterinas/farmacologia , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Proteínas de Transporte de Nucleosídeo Equilibrativas/antagonistas & inibidores , Proteínas de Transporte de Nucleosídeo Equilibrativas/metabolismo , Feminino , Células HeLa , Humanos , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos C57BL , Oócitos/metabolismo , Ratos , Ratos Sprague-Dawley , Tioinosina/análogos & derivados , Tioinosina/farmacologia , Xenopus laevis
16.
Physiother Theory Pract ; 37(5): 559-582, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-31317831

RESUMO

Background: There is no robust evidence on the contribution of reduced hamstring flexibility to the development of low back pain (LBP) in cohort studies.Purpose: To investigate whether individuals with LBP have impaired hamstring flexibility and stiffness and what measures have been used to compare hamstring flexibility and stiffness between individuals with and without LBP.Methods: A systematic literature search was undertaken in PubMed, EMBASE, MEDLINE, CINAHL, SCOPUS, and Cochrane databases from inception to April 2018. The GRADE system was used to determine the quality of evidence for each measure evaluated in meta-analysis.Results: Respectively, seventeen and two studies having acceptable methodological quality were analyzed with regard to hamstring flexibility and stiffness. Four measures were identified for hamstring flexibility and five for stiffness. Meta-analyses were undertaken in straight leg raising (SLR), sit and reach and knee extension in 90° hip flexion for hamstring flexibility and for hamstring stiffness measures of stiffness at 50° SLR and gradient of stiffness from 20° to 50° SLR (Me-grad). Significantly reduced hamstring flexibility or increased stiffness (P < .05) was detected in SLR, 90/90 knee extension and Me-grad. However, the validity of measures for hamstring flexibility was problematic and GRADE scores for all measures in the meta-analyses were very low.Conclusion: There have been four measures for hamstring flexibility and five for stiffness to evaluate individuals with and without LBP. It was impossible to conclude whether individuals with LBP have impaired hamstring flexibility and stiffness due to very low quality of evidence for meta-analyses.


Assuntos
Músculos Isquiossurais/fisiopatologia , Dor Lombar/fisiopatologia , Amplitude de Movimento Articular/fisiologia , Humanos
17.
Mol Genet Metab ; 94(4): 410-416, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18511317

RESUMO

Cellular uptake of sepiapterin resulted in an efficient accumulation of tetrahydrobiopterin. Tetrahydrobiopterin is much less permeable across the cell membrane than sepiapterin or dihydrobiopterin, the precursors of the tetrahydrobiopterin-salvage pathway. The uptake of sepiapterin by the cell was examined under metabolic arrest with N-acetylserotonin, an inhibitor of sepiapterin reductase. The release profile of previously accumulated sepiapterin was also analyzed. Two routes were clearly distinguishable, namely rapid and slow. Both were apparently bi-directional and equilibrating in type. Each route was connected to non-mixable pools somehow separated in the cell. The rapid process was too fast to analyze by the current methods of cell handling. The slower process was associated with conversion of sepiapterin to tetrahydrobiopterin in the absence of N-acetylserotonin, suggesting that this route opens into the cytosolic compartment where use of the salvage pathway was strongly driven by sepiapterin reductase and dihydrofolate reductase with a supply of NADPH which favors tetrahydrobiopterin accumulation. Consequently, sepiapterin was enforcedly taken up by the cell where it accumulated tetrahydrobiopterin in the cytosol in continuous manner.


Assuntos
Biopterinas/análogos & derivados , Pterinas/metabolismo , Transporte Biológico , Biopterinas/metabolismo , Membrana Celular/metabolismo , Citoplasma/metabolismo , Células HeLa , Humanos
18.
J Phys Chem Lett ; 9(2): 420-424, 2018 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-29298071

RESUMO

Some heterojunction interfaces formed with molecular solids show metal-like transport behavior. In order to clarify the requirement, interfaces are fabricated by lamination of single-crystal electron-accepting 2,5-difluoro-7,7,8,8-tetracyanoquinodimethane (F2TCNQ) and electron-donating molecules with a wide range of ionization potentials. Carrier injection between the acceptor and donor crystals leads to highly conducting interfaces, some of which exhibited band-like charge transport behaviors. Combinations with weak donors also resulted in interfaces with band-like transport properties. Accordingly, band-like conduction was achieved for interfaces where the donor and acceptor crystals do not have well-matched band energies. The results indicate that the wide range of candidates have great potential for modification of the electronic structure of organic crystals. The present method is expected to enable control of the electronic properties of the interface.

19.
J Neurosci ; 26(2): 530-4, 2006 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-16407550

RESUMO

Serotonin [5-hydroxytryptamine (5-HT)] is a major therapeutic target of psychiatric disorders. Tryptophan hydroxylase (TPH) catalyzes the rate-limiting reaction in the biosynthesis of 5-HT. Two isoforms (TPH1 and TPH2) having tryptophan hydroxylating activity were identified. Association studies have revealed possible TPH1 involvement in psychiatric conditions and behavioral traits. However, TPH1 mRNA was reported to be mainly expressed in the pineal gland and the periphery and to be barely detected in the brain. Therefore, contribution of TPH1 to brain 5-HT levels is not known, and the mechanisms how TPH1 possibly contributes to the pathogenesis of psychiatric disorders are not understood. Here, we show an unexpected role of TPH1 in the developing brain. We found that TPH1 is expressed preferentially during the late developmental stage in the mouse brain. TPH1 showed higher affinity to tryptophan and stronger enzyme activity than TPH2 in a condition reflecting that of the developing brainstem. Low 5-HT contents in the raphe nucleus were seen during development in New Zealand white (NZW) and SWR mice having common functional polymorphisms in the TPH1 gene. However, the 5-HT contents in these mice were not reduced in adulthood. In adult NZW and SWR mice, depression-related behavior was observed. Considering an involvement of developmental brain disturbance in psychiatric disorders, TPH1 may act specifically on development of 5-HT neurons, and thereby influence behavior later in life.


Assuntos
Encéfalo/enzimologia , Serotonina/biossíntese , Triptofano Hidroxilase/fisiologia , Animais , Antidepressivos/uso terapêutico , Biopterinas/análogos & derivados , Biopterinas/metabolismo , Encéfalo/crescimento & desenvolvimento , Células COS , Chlorocebus aethiops , Depressão/tratamento farmacológico , Depressão/genética , Depressão/psicologia , Indução Enzimática , Reação de Congelamento Cataléptica , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Imipramina/uso terapêutico , Camundongos , Camundongos Endogâmicos , Paroxetina/uso terapêutico , RNA Mensageiro/biossíntese , Núcleos da Rafe/crescimento & desenvolvimento , Núcleos da Rafe/metabolismo , Proteínas Recombinantes de Fusão/fisiologia , Serotonina/deficiência , Triptofano/metabolismo , Triptofano Hidroxilase/análise , Triptofano Hidroxilase/biossíntese , Triptofano Hidroxilase/deficiência , Triptofano Hidroxilase/genética
20.
Mol Neurobiol ; 35(1): 45-54, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17519505

RESUMO

The serotonin 5-hydroxytryptamine (5-HT) neurotransmitter system contributes to various physiological and pathological conditions. 5-HT is the first neurotransmitter for which a developmental role was suspected. Tryptophan hydroxylase (TPH) catalyzes the rate-limiting reaction in the biosynthesis of 5-HT. Both TPH1 and TPH2 have tryptophan hydroxylating activity. TPH2 is abundant in the brain, whereas TPH1 is mainly expressed in the pineal gland and the periphery. However, TPH1 was found to be expressed predominantly during the late developmental stage in the brain. Recent advances have shed light on the kinetic properties of each TPH isoform. TPH1 showed greater affinity for tryptophan and stronger enzymic activity than TPH2 under conditions reflecting those in the developing brain stem. Transient alterations in 5-HT homeostasis during development modify the fine wiring of brain connections and cause permanent changes to adult behavior. An increasing body of evidence suggests the involvement of developmental brain disturbances in psychiatric disorders. These findings have revived a long-standing interest in the developmental role of 5-HT-related molecules. This article summarizes our understanding of the kinetics and possible neuronal functions of each TPH during development and in the adult.


Assuntos
Isoenzimas/metabolismo , Sistema Nervoso/enzimologia , Sistema Nervoso/crescimento & desenvolvimento , Triptofano Hidroxilase/metabolismo , Animais , Comportamento/fisiologia , Comportamento Animal/fisiologia , Humanos , Isoenzimas/genética , Transtornos Mentais/metabolismo , Transtornos Mentais/fisiopatologia , Sistema Nervoso/embriologia , Serotonina/metabolismo , Triptofano Hidroxilase/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA