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1.
Chem Pharm Bull (Tokyo) ; 67(7): 717-720, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31257327

RESUMEN

This study demonstrates the relation between the redox properties and cytotoxicity of anthraquinone derivatives with a hydroxyl and methoxy group. The redox behavior of the anthraquinone derivatives was initially observed via cyclic voltammetry and their characteristics were investigated using molecular orbital calculations. The cytotoxicity of the anthraquinone derivatives was then evaluated using human leukemia HL-60 and H2O2 resistant HP100 cells, and its correlation with the redox properties of these compounds was investigated. Therefore, it was suggested that the anthraquinone derivatives express cytotoxicity through H2O2 production, and that generation of the oxidized radical form influences their cytotoxicity.


Asunto(s)
Antraciclinas/química , Antraquinonas/química , Antineoplásicos/química , Antraciclinas/farmacología , Antraquinonas/farmacología , Antineoplásicos/farmacología , Supervivencia Celular/efectos de los fármacos , Técnicas Electroquímicas , Células HL-60 , Humanos , Peróxido de Hidrógeno/metabolismo , Oxidación-Reducción , Teoría Cuántica
2.
Chem Pharm Bull (Tokyo) ; 62(1): 88-91, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24390497

RESUMEN

This study demonstrated that the electro-chemical analysis of hydrophobic quinones can be performed in liposome suspension systems. We prepared and analyzed liposome suspensions containing lapachol, which is a quinone-based anti-tumor activity compound. In this suspension system, a simple one redox couple of lapachol is observed. These results are quite different from those obtained in organic solvents. In addition, the pH dependence of redox behaviors of lapachol could be observed in multilamellar vesicle (MLV) suspension system. This MLV suspension system method may approximate the electrochemical behavior of hydrophobic compounds in aqueous conditions. A benefit of this liposome suspension system for electrochemical analysis is that it enables to observe water-insoluble compounds without using organic solvents.


Asunto(s)
Liposomas/química , Naftoquinonas/química , Suspensiones/química , Electroquímica , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Quinonas/química , Solventes/química
3.
J Anesth ; 30(6): 1095, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27535141
4.
J Org Chem ; 75(6): 1997-2009, 2010 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-20180528

RESUMEN

The diverse electrochemical and chemical oxidations of dichalcogena-mesocycles are analyzed, broadening our understanding of the chemistry of the corresponding radical cations and dications. 1,5-Diselenocane and 1,5-ditellurocane undergo reversible two-electron oxidation with inverted potentials analogous to 1,5-dithiocane. On the other hand, 1,5-selenathiocane and 1,5-tellurathiocane undergo one-electron oxidative dimerization. The X-ray crystal structures of the Se-Se dimer of the 1,5-selenathiocane one-electron oxidized product and the monomeric two-electron oxidized product (dication) of 1,5-tellurathiocane are reported. 1,5-Dithiocanes and 1,5-diselenocanes with group 14 atoms as ring members undergo irreversible oxidation, unlike the reversible two-electron oxidation of the corresponding silicon-containing 1,5-ditellurocanes. These results demonstrate the chemical consequences of the dication stabilities Te(+)-Te(+) > Se(+)-Se(+) > S(+)-S(+), as well as Se(+)-Se(+) > Se(+)-S(+) and Te(+)-Te(+) > Te(+)-S(+).

5.
J Vasc Access ; 21(1): 110-115, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31169047

RESUMEN

This study presents the initial 3-year results of the first in-human study of internal shunt restoration using completely autologous vascular grafts, "Biotubes," based on in-body tissue architecture. Biotubes (diameter, 6 mm; length, 7 cm) were prepared as autologous collagenous tubular tissues with approximately 0.5 mm wall thickness by embedding molds (two per patient), assembled with a silicone rod and a stainless steel pipe with many slits, into the patients' abdominal subcutaneous tissue for 2 months. Two female patients with end-stage renal disease were undergoing hemodialysis with a high probability of failure due to repeated stenosis every few months at the venous outflow regions over 1.5 years. Biotubes formed in both patients and were bypassed over the venous stenosis region of the arteriovenous shunt. After bypass with Biotubes without living cells, palpable thrill and typical turbulent flow pattern were observed by pulsed-wave Doppler. Follow-up angiography showed no signs of dilation or stenosis after implantation, and puncture could be performed easily without graft damage. In both cases, stenosis of Biotubes occurred after 3-4 months. In the first case, percutaneous transluminal angioplasty was not required for over 2 years after implantation even after the development of Biotube stenosis. In the second case, stenosis at the proximal anastomotic site of the Biotube became prominent, and percutaneous transluminal angioplasty was needed 7 months after implantation and then repeated at up to 2 years. This was the first human study successfully supporting the concept of internal shunt restoration for hemodialysis using an autologous Biotube.


Asunto(s)
Derivación Arteriovenosa Quirúrgica/instrumentación , Bioprótesis , Implantación de Prótesis Vascular/instrumentación , Prótesis Vascular , Fallo Renal Crónico/terapia , Ingeniería de Tejidos/métodos , Femenino , Humanos , Fallo Renal Crónico/diagnóstico , Persona de Mediana Edad , Diseño de Prótesis , Diálisis Renal , Resultado del Tratamiento , Grado de Desobstrucción Vascular
6.
J Phys Chem B ; 124(5): 848-860, 2020 02 06.
Artículo en Inglés | MEDLINE | ID: mdl-31923355

RESUMEN

We have carried out an electrochemical and theoretical study on the relationship between electron transfer (ET) and hydrogen bonding in 11 different 9,10-anthraquinone (AQ) derivatives, including ß-hydroxy AQs and their methoxylated analogs, in the presence of hydrogen donors in acetonitrile (ACN). The complementary effects of the intra- and intermolecular hydrogen bonds (HBs) on ET were studied by analyzing the complex formation constants derived from the intermolecular HB. Our results revealed that the inductive effect of the ß substituent that indirectly controls the charge distribution on the AQ carbonyl oxygen, and steric hindrance at the ß position, affect the complex formation constants. Furthermore, the analysis of ET in different isomeric dihydroxy AQs suggested that the position of the hydroxy groups affects the charge distribution and stabilizes structures through conjugation of the quinone moiety including the ipso ring, controlling the intra- and intermolecular HBs complementarily.

7.
Yakugaku Zasshi ; 139(9): 1195-1200, 2019.
Artículo en Japonés | MEDLINE | ID: mdl-31474635

RESUMEN

In this study, we attempted to improve the non-aqueous titration method using N,N-dimethylformamide (DMF) in the Japanese Pharmacopoeia seventeenth edition (JP XVII) for advancement in experimental safety. As an alternative solvent for DMF, we demonstrate titrations using dimethyl sulfoxide (DMSO), which has similar properties as and much higher safety than DMF. Five drugs (i.e., acetohexamide, glibenclamide, sulfamethoxazole, tranilast, and furosemide) listed in JP XVII use DMF as a solvent for titrations with sodium hydroxide standard solution. For these drugs, we examined whether DMF can be replaced with DMSO in quantitative analyses. As a result, a quantification similar to that of the Pharmacopoeia protocol is possible by simply replacing DMF with DMSO or using a mixed solvent of DMSO and water.


Asunto(s)
Dimetilsulfóxido , Dimetilformamida , Farmacopeas como Asunto , Mejoramiento de la Calidad , Seguridad , Solventes , Volumetría/métodos , Japón , Hidróxido de Sodio , Soluciones , Agua
8.
J Phys Chem B ; 110(43): 22043-7, 2006 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-17064175

RESUMEN

The electrochemical reduction of 3,5-di-tert-butyl-1,2-benzoquinone, 1, has been studied in acetonitrile with added 2,2,2-trifluoroethanol, 2. At low concentrations of 2 the reaction proceeds by the following pathway: reduction of the quinone (Q) to its anion radical (Q*-) followed by complexation of the anion radical with 2 (HA) and the further reduction of the hydrogen-bonded complex (Q*- (HA)) to form HQ- and A-. The latter reaction is a concerted proton and electron- transfer reaction (CPET). At higher concentrations of 2, the pathway changes. The first steps remain the same, but now Q*- (HA) is reduced to HQ- via a disproportionation reaction with Q*- along with proton transfer from HA to Q*- to form HQ* which is reduced to HQ-. The only mechanism that could be found which would account for all of the data involves proton transfer to Q*- occurring within a higher complex, Q*-(HA)3.


Asunto(s)
Benzoquinonas/química , Trifluoroetanol/química , Electroquímica , Oxidación-Reducción
9.
Biomed Mater Eng ; 16(1): 23-32, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16410641

RESUMEN

The effect of genistein, a soybean isoflavone, on new bone formation by bone marrow cells from mature rats and humans was examined. Bone marrow cells were collected from the femoral diaphysis of 7-week-old Fisher rats, cultured in MEM containing fetal calf serum and then cultured with or without the addition of dexamethasone to the bone-forming medium. Genistein was added at concentrations of 10(-5),10(-6),10(-7) or 10(-8) M. Bone formation was examined 2 weeks after culture. After informed consent was obtained from a 55-year-old woman with lumbar spondylosis deformans, bone marrow cells were collected from her ilium for culture by the same process, and bone formation investigated. In both rats and humans, when dexamethasone was added to the bone-forming medium, genistein (10(-7) M and 10(-8) M) caused a significant increase in the levels of calcium, alkaline phosphatase, and DNA compared with cells not cultured in genistein. In conclusion, genistein was found to promote bone formation at lower concentrations across species, and thus may be useful as a bone formation-promoting factor.


Asunto(s)
Genisteína/administración & dosificación , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/fisiología , Osteoblastos/citología , Osteoblastos/fisiología , Osteogénesis/fisiología , Ingeniería de Tejidos/métodos , Animales , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Células Madre Hematopoyéticas/efectos de los fármacos , Masculino , Osteoblastos/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Ratas , Ratas Endogámicas F344
12.
J Biomed Mater Res B Appl Biomater ; 104(7): 1431-7, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-26227350

RESUMEN

Completely autologous in vivo tissue-engineered connective tissue tubes (Biotubes) have promise as arterial vascular grafts in animal implantation studies. In this clinical study of patients undergoing peritoneal dialysis (PD) (n = 11; age: 39-83 years), we evaluated human Biotubes' (h-Biotubes) mechanical properties to determine whether Biotubes with feasibility as vascular grafts could be formed in human bodies. We extracted PD catheters, embedded for 4-47 months, and obtained tubular connective tissues as h-Biotubes (internal diameter: 5 mm) from around the catheter' silicone tubular parts. h-Biotubes were composed mainly of collagen with smooth luminal surfaces. The average wall thickness was 278 ± 178 µm. No relationship was founded between the tubes' mechanical properties and patients' ages or PD catheter embedding periods statistically. However, the elastic modulus (2459 ± 970 kPa) and tensile strength (623 ± 314 g) of h-Biotubes were more than twice as great as those from animal Biotubes, formed from the same PD catheters by embedding in the beagle subcutaneous pouches for 1 month, or beagle arteries. The burst strength (6338 ± 1106 mmHg) of h-Biotubes was almost the same as that of the beagle thoracic or abdominal aorta. h-Biotubes could be formed in humans over a 4-month embedding period, and they satisfied the mechanical requirements for application as vascular grafts. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1431-1437, 2016.


Asunto(s)
Bioprótesis , Catéteres , Diálisis Peritoneal , Siliconas , Ingeniería de Tejidos , Adulto , Anciano , Anciano de 80 o más Años , Autoinjertos , Femenino , Humanos , Masculino , Persona de Mediana Edad
13.
J Chromatogr A ; 979(1-2): 91-6, 2002 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-12498236

RESUMEN

We have investigated detection of the anion radical and the divalent anion of tetracyanoquinodimethane (TCNQ) by acetonitrile-CE under anaerobic conditions. With electrolysis at a potential of 0.0 V (vs. Ag/AgCl), an acetonitrile solution of TCNQ turned green, characteristic of the TCNQ anion radical (TCNQ-). Only one peak of the anionic compound was observed in CE of the electrolysis solution and it should be that of TCNQ-. Then, the electrolysis potential was shifted to -0.8 V expected to be sufficient potential for the further reduction of TCNQ-, and the solution turned almost colourless. In CE analysis of the latter solution, another anionic component possessing a larger electrophoretic mobility than that of TCNQ- was detected, and it was decomposed immediately under aerobic conditions. This product was strongly suggested to be the divalent anion of TCNQ, and the present method would contribute notably to detection of the unstable species.


Asunto(s)
Electrólisis , Electroforesis Capilar/métodos , Nitrilos/análisis , Aniones , Radicales Libres , Nitrilos/química
14.
J Pediatr (Rio J) ; 79(1): 87-90, 2003.
Artículo en Portugués | MEDLINE | ID: mdl-12973515

RESUMEN

OBJECTIVE: To report a case of a 47 XYY male neonate with congenital heart disease and short stature. DESCRIPTION: This is the first case report of a 47 XYY male neonate associated with congenital heart disease (total anomalous pulmonary venous return) and small for date. The boy neonate was born at around 32 weeks of gestation with birthweight of 1134 g. An intracranial hemorrhage and pulmonary high flow were discovered at an early neonatal period. His physical and mental development was very retarded. The infant underwent a palliative ligation of ductus arteriosus and a ventriculoperitoneal shunt operation, but subsequently died due to consequent heart failure at 19 month-old. COMMENTS: This combination of XYY male and congenital heart disease may be a fortuitous one. However, we think it is important to report that there was a poor prognosis case of XYY male with congenital heart disease and short-stature.


Asunto(s)
Anomalías Múltiples , Trastornos del Crecimiento/complicaciones , Cardiopatías Congénitas/complicaciones , Venas Pulmonares/anomalías , Cariotipo XYY , Humanos , Recién Nacido , Masculino
16.
PLoS One ; 8(5): e63265, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23691006

RESUMEN

The canonical Wnt/ß-catenin signaling pathway plays a crucial role in the maintenance of the balance between proliferation and differentiation throughout embryogenesis and tissue homeostasis. ß-Catenin, encoded by the Ctnnb1 gene, mediates an intracellular signaling cascade activated by Wnt. It also plays an important role in the maintenance of various types of stem cells including adult stem cells and cancer stem cells. However, it is unclear if ß-catenin is required for the derivation of mouse embryo-derived stem cells. Here, we established ß-catenin-deficient (ß-cat(Δ/Δ)) mouse embryo-derived stem cells and showed that ß-catenin is not essential for acquiring self-renewal potential in the derivation of mouse embryonic stem cells (ESCs). However, teratomas formed from embryo-derived ß-cat(Δ/Δ) ESCs were immature germ cell tumors without multilineage differentiated cell types. Re-expression of functional ß-catenin eliminated their neoplastic, transformed phenotype and restored pluripotency, thereby rescuing the mutant ESCs. Our findings demonstrate that ß-catenin has pleiotropic effects in ESCs; it is required for the differentiation of ESCs and prevents them from acquiring tumorigenic character. These results highlight ß-catenin as the gatekeeper in differentiation and tumorigenesis in ESCs.


Asunto(s)
Carcinogénesis/genética , Diferenciación Celular/genética , Células Madre Embrionarias/citología , Células Madre Embrionarias/patología , Pleiotropía Genética , beta Catenina/metabolismo , Animales , Blastocisto/citología , Blastocisto/patología , Células Madre Embrionarias/metabolismo , Exones/genética , Femenino , Eliminación de Gen , Masculino , Ratones , Ratones Endogámicos C57BL , Teratoma/genética , Teratoma/patología , beta Catenina/deficiencia , beta Catenina/genética
18.
Intern Med ; 49(12): 1179-83, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20558939

RESUMEN

A standard treatment has not yet been established for elderly small-cell lung cancer patients, especially when they have end-stage renal disease. We report the first case of successful chemoradiotherapy in an elderly small-cell lung cancer patient undergoing continuous ambulatory peritoneal dialysis. A 77-year-old Japanese man on continuous ambulatory peritoneal dialysis was diagnosed as having limited disease small-cell lung cancer. He received four monthly cycles of chemotherapy consisting of carboplatin at 240 mg/m(2) on day 1 and etoposide at 40 mg/m(2) on days 1 and 3. He underwent additional hemodialysis on days 1 and 3, while continuous ambulatory peritoneal dialysis continued as usual on the other days. Following chemotherapy, he underwent hyperfractionated radiotherapy to a total dose of 45 Grey, resulting in complete remission of the disease. A pharmacokinetic study showed an area under the concentration-time curve of carboplatin of 3.41 to 4.88 mg.min/mL, increasing gradually over the first three cycles, while etoposide did not show this gradual increase. The increased area under the concentration-time curve of carboplatin may have reflected a worsened renal function during chemotherapy. Despite dose reductions and favorable areas under the concentration-ime curve of carboplatin, the patient suffered grade 3-4 hematological toxicities, necessitating transfusions and a further dose reduction. The patient died of recurrent small-cell lung cancer 19 months after diagnosis.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias Pulmonares/terapia , Diálisis Peritoneal Ambulatoria Continua , Carcinoma Pulmonar de Células Pequeñas/terapia , Factores de Edad , Anciano , Carboplatino/administración & dosificación , Etopósido/administración & dosificación , Humanos , Neoplasias Pulmonares/diagnóstico , Masculino , Diálisis Peritoneal Ambulatoria Continua/métodos , Carcinoma Pulmonar de Células Pequeñas/diagnóstico , Resultado del Tratamiento
19.
Chem Res Toxicol ; 21(12): 2272-9, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19548351

RESUMEN

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is a synthetic recreational drug of abuse that produces long-term toxicity associated with the degeneration of serotonergic nerve terminals. In various animal models, direct administration of MDMA into the brain fails to reproduce the serotonergic neurotoxicity, implying a requirement for the systemic metabolism and bioactivation of MDMA. Catechol-thioether metabolites of MDMA, formed via oxidation of 3,4-dihydroxymethamphetamine and 3,4-dihydroxyamphetamine (HHMA and HHA) and subsequent conjugation with glutathione (GSH), are selective serotonergic neurotoxicants when administered directly into brain. Moreover, following systemic administration of MDMA, the thioether adducts are present in rat brain dialysate. MDMA contains a stereogenic center and is consumed as a racemate. Interestingly, different pharmacological properties have been attributed to the two enantiomers, (S)-MDMA being the most active in the central nervous system and responsible for the entactogenic effects, and most likely also for the neurodegeneration. The present study focused on the synthesis and stereochemical analysis of the neurotoxic MDMA thioether metabolites, 5-(glutathion-S-yl)-HHMA, 5-(N-acetylcystein-S-yl)-HHMA, 2,5-bis-(glutathion-S-yl)-HHMA, and 2,5-bis-(N-acetylcystein-S-yl)-HHMA. Both enzymatic and electrochemical syntheses were explored, and methodologies for analytical and semipreparative diastereoisomeric separation of MDMA thioether conjugates by HPLC-CEAS and HPLC-UV, respectively, were developed. Synthesis, diastereoisomeric separation, and unequivocal identification of the thioether conjugates of MDMA provide the chemical tools necessary for appropriate toxicological and metabolic studies on MDMA metabolites contributing to its neurotoxicity.


Asunto(s)
N-Metil-3,4-metilenodioxianfetamina/análogos & derivados , Serotoninérgicos , Sulfuros/síntesis química , Cromatografía Líquida de Alta Presión , Electroquímica , Electrodos , Glutatión/análogos & derivados , Glutatión/química , Glutatión/metabolismo , Monofenol Monooxigenasa/metabolismo , N-Metil-3,4-metilenodioxianfetamina/metabolismo , Oxidación-Reducción , Serotoninérgicos/síntesis química , Serotoninérgicos/química , Serotoninérgicos/aislamiento & purificación , Estereoisomerismo
20.
Dalton Trans ; (32): 4247-53, 2008 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-18682863

RESUMEN

The reactions of the previously reported cluster complexes [Re(6)(mu(3)-Se)(8)(PEt(3))(5)I]I, trans-[Re(6)(mu(3)-Se)(8)(PEt(3))(4)I(2)], and cis-[Re(6)(mu(3)-Se)(8)(PEt(3))(4)I(2)] with the [Re(6)(mu(3)-Se)(8)](2+) core with CO in the presence of AgSbF(6) afforded the corresponding cluster carbonyls [Re(6)(mu(3)-Se)(8)(PEt(3))(5)(CO)][SbF(6)](2) (), trans-[Re(6)(mu(3)-Se)(8)(PEt(3))(4)(CO)(2)][SbF(6)](2) (), and cis-[Re(6)(mu(3)-Se)(8)(PEt(3))(4)(CO)(2)][SbF(6)](2) (). Infrared spectroscopy indicated weakening of the bond in CO, suggesting the existence of backbonding between the cluster core and the CO ligand(s). Electrochemical studies focusing on the reversible, one-electron oxidation of the cluster core revealed a large increase in the oxidation potential upon going from the acetonitrile derivatives to their carbonyl analogs, consistent with the depleted electron density of the cluster core upon CO ligation. Disparities between the IR spectra and oxidation potential between and indicate that electronic differences exist between sites trans and cis to the location of a ligand of interest. The active role played by the Se atoms in influencing the cluster-to-CO bonding interactions is suggested through this result and density functional (DF) computational analysis. The computations indicate that molecular orbitals near the HOMO account for backbonding interactions with a high percentage of participation of Se orbitals.

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