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1.
J Synchrotron Radiat ; 28(Pt 6): 1954-1965, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34738951

RESUMO

The optical design and performance of the recently opened 13A biological small-angle X-ray scattering (SAXS) beamline at the 3.0 GeV Taiwan Photon Source of the National Synchrotron Radiation Research Center are reported. The beamline is designed for studies of biological structures and kinetics in a wide range of length and time scales, from angstrom to micrometre and from microsecond to minutes. A 4 m IU24 undulator of the beamline provides high-flux X-rays in the energy range 4.0-23.0 keV. MoB4C double-multilayer and Si(111) double-crystal monochromators (DMM/DCM) are combined on the same rotating platform for a smooth rotation transition from a high-flux beam of ∼4 × 1014 photons s-1 to a high-energy-resolution beam of ΔE/E ≃ 1.5 × 10-4; both modes share a constant beam exit. With a set of Kirkpatrick-Baez (KB) mirrors, the X-ray beam is focused to the farthest SAXS detector position, 52 m from the source. A downstream four-bounce crystal collimator, comprising two sets of Si(311) double crystals arranged in a dispersive configuration, optionally collimate the DCM (vertically diffracted) beam in the horizontal direction for ultra-SAXS with a minimum scattering vector q down to 0.0004 Å-1, which allows resolving ordered d-spacing up to 1 µm. A microbeam, of 10-50 µm beam size, is tailored by a combined set of high-heat-load slits followed by micrometre-precision slits situated at the front-end 15.5 m position. The second set of KB mirrors then focus the beam to the 40 m sample position, with a demagnification ratio of ∼1.5. A detecting system comprising two in-vacuum X-ray pixel detectors is installed to perform synchronized small- and wide-angle X-ray scattering data collections. The observed beamline performance proves the feasibility of having compound features of high flux, microbeam and ultra-SAXS in one beamline.


Assuntos
Fótons , Síncrotrons , Espalhamento a Baixo Ângulo , Taiwan , Difração de Raios X , Raios X
2.
J Chem Phys ; 151(20): 204701, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31779314

RESUMO

This work demonstrates by in vacuo X-ray photoelectron spectroscopy and grazing-incidence X-ray diffraction that Ru(EtCp)2 and O* radical-enhanced atomic layer deposition, where EtCp means the ethylcyclopentadienyl group, provides the growth of either RuO2 or Ru thin films depending on the deposition temperature (Tdep), while different mechanisms are responsible for the growth of RuO2 and Ru. The thin films deposited at temperatures ranging from 200 to 260 °C consisted of polycrystalline rutile RuO2 phase revealing, according to atomic force microscopy and the four-point probe method, a low roughness (∼1.7 nm at 15 nm film thickness) and a resistivity of ≈83 µΩ cm. This low-temperature RuO2 growth was based on Ru(EtCp)2 adsorption, subsequent ligand removal, and Ru oxidation by active oxygen. The clear saturative behavior with regard to the precursor and reactant doses and each purge time, as well as the good step coverage of the film growth onto 3D structures, inherent to genuine surface-controlled atomic layer deposition, were confirmed for the lowest Tdep of 200 °C. However, at Tdep = 260 °C, a competition between film growth and etching was found, resulted in not-saturative growth. At higher deposition temperatures (300-340 °C), the growth of metallic Ru thin films with a resistivity down to ≈12 µΩ cm was demonstrated, where the film growth was proved to follow a combustion mechanism known for molecular oxygen-based Ru growth processes. However, this process lacked the truly saturative growth with regard to the precursor and reactant doses due to the etching predominance.

3.
Clin Otolaryngol ; 43(1): 249-255, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28800204

RESUMO

OBJECTIVES: To compare the efficacy and safety of transoral robotic surgery (TORS) with endoscope-guided coblation tongue base resection. DESIGN: Retrospective case-control study. SETTING: University-based tertiary care medical center. PARTICIPANTS: Patients with obstructive sleep apnoea (OSA) who underwent endoscope-guided tongue base coblation resection or transoral robotic surgery (TORS) in combination with lateral pharyngoplasty at a single institution in South Korea between April 2013 and December 2016 were investigated. Forty-five patients who had moderate-to-severe OSA with tongue base collapse and a minimum follow-up period of 6 months with postoperative polysomnography (PSG) were enrolled in this study. MAIN OUTCOME MEASURES: All patients underwent pre- and postoperative (at least 4 months after surgery) overnight PSG. Available information on results of the PSG, Epworth sleepiness scale and complications of the TORS and coblation groups were compared. RESULTS: Postoperative PSG studies showed improved sleep quality for most patients. The mean postoperative apnoea-hypopnea index (AHI) was reduced significantly from 45.0 to 17.0 events/h (P < .0001) in the TORS group and from 45.6 to 16.2 events/h (P < .0001) in the coblation group. The mean rates of improvement (AHI reduction > 50%) were 75.0% in TORS patients and 62.1% in coblation patients and the difference was not significant. Less frequent postoperative morbidity, including bleeding, taste dysfunction and foreign body sensation, was recorded in TORS patients. CONCLUSIONS: Both the coblation and TORS groups showed similar surgical outcomes, TORS achieved PSG results non-inferior to and complication rates comparable to coblation.


Assuntos
Ablação por Cateter/métodos , Glossectomia/métodos , Procedimentos Cirúrgicos Robóticos/métodos , Apneia Obstrutiva do Sono/cirurgia , Língua/cirurgia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Complicações Pós-Operatórias/epidemiologia , República da Coreia/epidemiologia , Estudos Retrospectivos , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/fisiopatologia , Resultado do Tratamento
4.
Drug Alcohol Depend ; 175: 179-186, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28437722

RESUMO

BACKGROUND: Immunotherapies directed against methamphetamine (MA) abuse have shown success in rodent models, however only a limited number of studies have investigated active vaccination in female mice and none in female rats. It is critical to determine if potential immunotherapeutic strategies generalize across sex, particularly for drugs that may produce significant sex-differences on behavioral or physiological endpoints. METHODS: Female Wistar rats were initially vaccinated with keyhole-limpet hemocyanin (KLH) or an anti-methamphetamine-KLH conjugate (MH6-KLH) three times over five weeks and implanted with radiotelemetry devices to assess locomotor activity and body temperature responses to MA. Rats were first exposed to MA via vapor inhalation (100mg/mL in propylene glycol) and then by injection (0.25-1.0mg/kg, i.p.) and vapor after a final vaccine boost. RESULTS: The MH6-KLH vaccine generated an increase in antibody titers across the initial 6-week, 3 immunization protocol and a restoration of titer after a week 14 booster. Locomotor stimulation induced by 0.25mg/kg MA, i.p, in the KLH group was prevented in the MH6-KLH group. MH6-KLH animals also exhibited an attenuated locomotor stimulation produced by 0.5mg/kg MA, i.p. No group differences in locomotion induced by vapor inhalation of MA were observed and body temperature was not differentially affected by MA across the groups, most likely because vapor inhalation of MA that produced similar locomotor stimulation resulted in ∼10-fold higher plasma MA levels. CONCLUSIONS: This study confirms the efficacy of the MH6-KLH vaccine in attenuating the effects of MA in female rats.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Transtornos Relacionados ao Uso de Anfetaminas/prevenção & controle , Hemocianinas/administração & dosagem , Metanfetamina/efeitos adversos , Vacinação/métodos , Vacinas/administração & dosagem , Animais , Feminino , Imunização/métodos , Metanfetamina/administração & dosagem , Ratos , Ratos Wistar
5.
Free Radic Res ; 48(7): 794-805, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24678962

RESUMO

One major pathological hallmark of Alzheimer's disease (AD) is accumulation of senile plaques in patients' brains, mainly composed of amyloid beta-peptide (Aß). Nicotinamide adenine dinucleotide (NAD) has emerged as a common mediator regulating energy metabolism, mitochondrial function, aging, and cell death, all of which are critically involved in neuronal demise observed in AD. In this work, we tested the hypothesis that NAD may attenuate Aß-induced DNA damages, thereby conferring neuronal resistance to primary rat cortical cultures. We found that co-incubation of NAD dose-dependently attenuated neurotoxicity mediated by Aß25-35 and Aß1-42 in cultured rat cortical neurons, with the optimal protective dosage at 50 mM. NAD also abolished the formation of reactive oxygen species (ROS) induced by Aß25-35. Furthermore, Aßs were capable of inducing oxidative DNA damages by increasing the extents of 8-hydroxy-2´-deoxyguanosine (8-OH-dG), numbers of apurinic/apyrimidinic (AP) sites, genomic DNA single-stranded breaks (SSBs), as well as DNA double-stranded breaks (DSBs)/fragmentation, which can all be attenuated upon co-incubation with NAD. Our results thus reveal a novel finding that NAD is protective against DNA damage induced by existing Aß, leading ultimately to neuroprotection in primary cortical culture.


Assuntos
Peptídeos beta-Amiloides/farmacologia , Córtex Cerebral/citologia , Dano ao DNA , DNA/metabolismo , NAD/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Animais , Células Cultivadas , DNA/genética , DNA/isolamento & purificação , Camundongos , Camundongos Endogâmicos , Camundongos Transgênicos , Oxirredução/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo
7.
Transplant Proc ; 42(6): 2138-41, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20692427

RESUMO

To mitigate hyperacute rejection, pigs have been generated with alpha-Gal transferase gene knockout and transgenic expression of human decay accelerating factor (hDAF), MCP, and CD59. Additionally, heme-oxygenase-1 (HO-1) has been suggested to defend endothelial cells. Sera (MS) (0%, 1%, 5%, 10%, and 15%) from Formosan macaques (Macaca cyclopis, MC), an Old World monkey wildly populated in Taiwan, was used to test the protective in vitro, effects of hDAF or hDAF/hHO-1 on porcine aortic endothelial cells (pAEC) derived from hDAF(+), hDAF(+)/hHO-1(+), and hDAF(+)/hHO-1(-) and 1 nontransgenic pAEC. Ten percent human serum (HS) served as a positive control. When MS addition increased to 10% or 15%, all transgenic pAEC exhibited a greater survival than nontransgenic pAEC. Noticeably, 15% MS reduced survived to <10% versus >40% in nontransgenic and transgenic pAEC, respectively. These results revealed that hDAF exerted protective effects against MC complement activation. However, comparing with 10% MS and HS in pAEC of nontransgenic pigs, the survivability was higher in HS, suggesting that complement activation by MS was more toxic than that by HS. Furthermore, hDAF(+)/hHO-1(+) showed no further protection against effects of MS on transgenic pAEC.


Assuntos
Antígenos CD55/genética , Heme Oxigenase-1/genética , Animais , Animais Geneticamente Modificados , Antígenos CD59/genética , Técnicas de Inativação de Genes , Rejeição de Enxerto/prevenção & controle , Humanos , Rim/fisiologia , Macaca/genética , Macaca/imunologia , Macaca/metabolismo , Papio , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Suínos , Transgenes , Transplante Heterólogo
8.
Br J Ophthalmol ; 93(9): 1260-4, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19429577

RESUMO

BACKGROUND/AIMS: Patients with autoimmune polyendocrinopathy-candiasis-ectodermal dystrophy (APECED) develop severe keratoconjunctivitis, corneal scarring and visual loss, but the precise pathogenesis is unknown. This study evaluated the ocular surface immune cell environment, conjunctival goblet cell density and response to desiccating environmental stress of the autoimmune regulatory (Aire) gene knockout murine model of APECED. METHODS: Aire-deficient and wild type (WT) mice were subjected to desiccating stress from a drafty, low-humidity environment and pharmacological inhibition of tear secretion for 5 days. Immune cell populations (CD4(+), CD8(+), CD11b(+), CD45(+)) and goblet cell density were measured in ocular surface tissues and meibomian glands, and compared with baseline values. RESULTS: Greater CD4(+) T cell populations were observed in the conjunctival epithelium of Aire-deficient mice (p<0.001) compared with WT. Aire-deficient mice also had greater numbers of CD4(+), CD8(+), and CD11b(+) cells in the peripheral cornea at baseline and following desiccating stress. The meibomian glands of Aire-deficient mice demonstrated greater CD4(+), CD8(+), CD45(+) and CD11b(+) cells at baseline (p<0.001) and following desiccating stress. Conjunctival goblet cell density was lower at baseline and following desiccating stress in Aire-deficient compared with WT mice (p<0.001). CONCLUSION: Aire-deficiency leads to infiltration of CD4(+) and CD8(+) T cells on the ocular surface and meibomian glands, which is accompanied by goblet cell loss. Desiccating stress promotes this proinflammatory milieu. Immune-mediated mechanisms play a role in the severe blepharitis and keratoconjunctivitis in the murine model of APECED.


Assuntos
Células Caliciformes/imunologia , Ceratoconjuntivite/imunologia , Poliendocrinopatias Autoimunes/imunologia , Linfócitos T/imunologia , Fatores de Transcrição/deficiência , Animais , Ceratoconjuntivite/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Poliendocrinopatias Autoimunes/patologia , Linfócitos T/patologia , Proteína AIRE
9.
J Clin Pharm Ther ; 31(4): 401-6, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16882113

RESUMO

Chronic myelomonocytic leukaemia (CMML) is a preleukaemic condition with myeloproliferative features, and classified as a part of myelodysplastic syndrome (MDS). Other than alkylating agents and topoisomerase II inhibitors, there is less evidence that chemotherapeutic drugs are associated with therapy-related CMML, acute leukaemia or MDS. We present a patient who developed CMML within 2 years of platinum-based chemotherapy for a metastatic non-small cell lung cancer. He received a cumulative dose of 240 mg/m(2) of cisplatin, and 1123 mg/m(2) of carboplatin before developing CMML. The cytogenetic study revealed trisomy 8. This is the first reported case that links platinum-based therapy with development of CMML with trisomy 8. Although the relationship between platinum therapy and the development of CMML is difficult to assess due to combinational nature of therapy in most cases, physicians should consider the possibility of CMML in patients with symptoms or signs suggestive of haematologic malignancy after platinum therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Cisplatino/efeitos adversos , Leucemia Mielomonocítica Crônica/induzido quimicamente , Neoplasias Pulmonares/tratamento farmacológico , Etoposídeo/administração & dosagem , Evolução Fatal , Humanos , Leucemia Mielomonocítica Crônica/fisiopatologia , Masculino , Pessoa de Meia-Idade
10.
J Korean Med Sci ; 16(6): 769-73, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11748360

RESUMO

Information on precise effects of deflazacort on bone cell function, especially osteoclasts, is quite limited. Therefore, the present study was undertaken to test effects of deflazacort on osteoclast-like cell formation in mouse bone marrow cultures and on the regulation of osteoprotegerin (OPG) and its ligand (RANKL) mRNA expressions by RT-PCR in the ST2 marrow stromal cells. TRAP-positive mononuclear cells increased after the treatment of deflazacort at 10(-9) to 10(-7) M alone for 6 days in a dose-dependent manner. Number of TRAP-positive multi-nucleated cells (MNCs) increased significantly with combined treatment of deflazacort at 10(-7) M and 1,25-(OH)2D3 at 10(-9) M compared to that of cultures treated with 1,25-(OH)2D3 alone (p<0.05). Exposure to deflazacort at 10(-7) M in the presence of 1,25-(OH)2D3 at 10(-9) M in the last 3-day culture had greater stimulatory effect on osteoclast-like cell formation than that of the first 3-day culture did. Deflazacort at 10(-10) -10(-6) M downregulated OPG and upregulated RANKL in mRNA levels in a dose-dependent manner. These observations suggest that deflazacort stimulate osteoclast precursor in the absence of 1,25-(OH)2D3 and enhance differentiation of osteoclasts in the presence of 1,25-(OH)2D3. These effects are, in part, thought to be mediated by the regulation of the expression of OPG and RANKL mRNA in marrow stromal cells.


Assuntos
Células da Medula Óssea/citologia , Proteínas de Transporte/genética , Glicoproteínas/genética , Imunossupressores/farmacologia , Glicoproteínas de Membrana/genética , Osteoclastos/citologia , Pregnenodionas/farmacologia , Receptores Citoplasmáticos e Nucleares/genética , Animais , Calcitriol/farmacologia , Agonistas dos Canais de Cálcio/farmacologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Dexametasona/farmacologia , Expressão Gênica/efeitos dos fármacos , Glucocorticoides/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Osteoprotegerina , Ligante RANK , RNA Mensageiro/análise , Receptor Ativador de Fator Nuclear kappa-B , Receptores do Fator de Necrose Tumoral , Células Estromais/citologia
11.
J Korean Med Sci ; 16(5): 549-52, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11641521

RESUMO

The human transforming growth factor-beta 3 (TGF-beta 3) is an important cytokine to maintain bone mass by inhibiting osteoclast differentiation. Recently raloxifene response element (RRE), a new enhancer with a polypurine sequence for estrogen receptor (ER)-mediated gene activation, was identified on the TGF-beta 3 gene. Functional analysis of the RRE-mediated pathway has shown that this would be an important pathway for bone preserving effect. We found a novel mutation in the RRE sequence by single-strand conformational polymorphism analysis in one of 200 Korean women. Cloning and sequencing revealed a heterozygote in which one allele had an insertion of 20 nucleotides (AGAGAGGGAGAGGGAGA GGG) between nucleotide +71 and +72 and a point mutation at nucleotide +75 (G-A transition), and the other allele had normal sequence. The insertion was a nearly perfect tandem duplication of the wild type DNA sequence. The bone mineral density of the affected woman was not much lower than that of age-matched controls. Transient transfection of the mutant allele showed no significantly different activity compared with that of the wild type allele. These observations suggest that the heterozygote variation of the RRE sequence seems not to be operative in determination of bone mass.


Assuntos
Antagonistas de Estrogênios/farmacologia , Mutação , Cloridrato de Raloxifeno/farmacologia , Elementos de Resposta , Fator de Crescimento Transformador beta/genética , Feminino , Humanos , Pessoa de Meia-Idade , Transfecção
12.
J Pediatr Surg ; 36(7): 1073-5, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11431783

RESUMO

Duodenojejunal intussusception is a rare pediatric emergency. A case of duodenojejunal intussusception secondary to hamartomatous polyps of the second portion of duodenum in a 10-month-old boy is reported. Surgical excision of the polyps and reduction of the intussusception were performed. Pathologic examination found hamartomatous polyps. This is the third case report of children in literature, but this is the first case of a child with intussusception surrounding the ampulla of Vater and a successful excision performed without damaging the ampulla of Vater.


Assuntos
Duodenopatias/etiologia , Neoplasias Duodenais/complicações , Hamartoma/complicações , Pólipos Intestinais/complicações , Intussuscepção/etiologia , Doenças do Jejuno/etiologia , Ampola Hepatopancreática/patologia , Duodenopatias/cirurgia , Neoplasias Duodenais/patologia , Neoplasias Duodenais/cirurgia , Hamartoma/patologia , Hamartoma/cirurgia , Humanos , Lactente , Pólipos Intestinais/patologia , Pólipos Intestinais/cirurgia , Intussuscepção/cirurgia , Doenças do Jejuno/cirurgia , Masculino
13.
Biochim Biophys Acta ; 1527(1-2): 31-8, 2001 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-11420140

RESUMO

The relevance of NADH-cytochrome b(5) reductase to the NADH-dependent reduction of D-erythroascorbyl free radical was investigated in Saccharomyces cerevisiae. MCR1, which is known to encode NADH-cytochrome b(5) reductase in S. cerevisiae, was disrupted by the insertion of URA3 gene into the gene of MCR1. In the mcr1 disruptant cells, the activity of NADH-D-erythroascorbyl free radical reductase almost disappeared and the intracellular level of D-erythroascorbic acid was about 11% of that of the congenic wild-type strain. In the transformant cells carrying MCR1 in multicopy plasmid, the intracellular level of D-erythroascorbic acid and the activity of NADH-D-erythroascorbyl free radical reductase increased up to 1.7-fold and 2.1-fold, respectively. Therefore, it indicated that the MCR1 product, mitochondrial NADH-cytochrome b(5) reductase, plays a key role in the NADH-dependent reduction of D-erythroascorbyl free radical in S. cerevisiae. On the other hand, the mcr1 disruptant cells were hypersensitive to hydrogen peroxide and menadione, and overexpression of MCR1 made the cells more resistant against oxidative stress. These results suggested that the mitochondrial NADH-cytochrome b(5) reductase functions as NADH-D-erythroascorbyl free radical reductase and plays an important role in the response to oxidative damage in S. cerevisiae.


Assuntos
Ácido Ascórbico/metabolismo , Redutases do Citocromo/metabolismo , Mitocôndrias/enzimologia , Saccharomyces cerevisiae/enzimologia , Citocromo-B(5) Redutase , Radicais Livres/metabolismo , Oxirredução , Estresse Oxidativo/fisiologia , Saccharomyces cerevisiae/metabolismo
14.
Am J Phys Med Rehabil ; 80(2): 92-9, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11212018

RESUMO

OBJECTIVE: Fifty consecutive cases of cardiopulmonary arrest with administration of cardiopulmonary resuscitation (CPR) during a 6-yr period at a freestanding academic acute rehabilitation hospital were identified. DESIGN: Medical records of 49 patients were available for review. Outcomes of survival of arrest, survival to 24 hr postarrest, survival to discharge from the hospital were determined, and chi2 or Fisher's exact tests were performed to investigate relationships between survival and admission functional status, age, gender, and medical comorbidities. RESULTS: Forty-three percent of patients survived the initial arrest, 37% survived to 24 hr post-CPR, and 18% survived to hospital discharge. We were unable to identify any statistically significant predictors of survival post-CPR. Six of the nine survivors returned to the acute rehabilitation setting after cardiopulmonary arrest, and five of these patients made significant functional gains. CONCLUSIONS: Outcomes after CPR in patients undergoing acute rehabilitation in one setting were not significantly different from those reported for patients in other healthcare settings. These data may be used by healthcare professionals to enhance discussions concerning advance healthcare planning (including resuscitation plans) with patients and families. Larger studies are needed to clarify the prognostic role of prior functional status in predicting CPR outcomes, particularly in the context of various diagnostic categories and age groups.


Assuntos
Reanimação Cardiopulmonar , Parada Cardíaca/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Parada Cardíaca/reabilitação , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
15.
Cancer Lett ; 158(2): 125-32, 2000 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-10960761

RESUMO

We investigated the mechanism of mitomycin C (MMC)-induced apoptosis in SNU-16 human gastric adenocarcinoma cells. Caspase-8 and caspase-3 were activated in MMC-treated cells whereas caspase-1 was not activated, and cytochrome c was released from mitochondrial membrane to cytosol suggesting that caspase-9 was activated during the MMC-induced apoptotic process. Protein kinase C (PKC) delta was cleaved to its characteristic 40 kDa fragment in a caspase-3-dependent manner; on the other hand PKC zeta was cleaved to approximately 40 kDa independently of caspase-3 in the drug-induced apoptosis of the cells. Incubation with z-DEVD-fmk and benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (z-VAD-fmk) almost completely abrogated MMC-induced DNA fragmentation, indicating that activation of these caspases was crucially involved in MMC-induced apoptosis. Activation of caspase-8 in response to Fas triggering by recruitment of caspase-8 to the Fas has also been found, however, MMC did not induce FasL and Fas expression, as evidenced by reverse transcriptase-polymerase chain reaction and Western blotting. Taken together, these findings indicate that MMC-induced apoptosis in SNU-16 cells was mediated by caspase-8, caspase-9, and caspase-3 activation independently of FasL/Fas interactions.


Assuntos
Adenocarcinoma/prevenção & controle , Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Mitomicina/farmacologia , Neoplasias Gástricas/prevenção & controle , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Clorometilcetonas de Aminoácidos/farmacologia , Caspase 3 , Caspase 8 , Caspase 9 , Inibidores de Caspase , Morte Celular/efeitos dos fármacos , Inibidores de Cisteína Proteinase/farmacologia , Ativação Enzimática/efeitos dos fármacos , Humanos , Oligopeptídeos/farmacologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Fatores de Tempo , Células Tumorais Cultivadas , Receptor fas/metabolismo
16.
Biochem Biophys Res Commun ; 258(2): 464-9, 1999 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-10329410

RESUMO

Uncoupling proteins (UCPs) are mitochondrial membrane proton transporters that uncouple oxidative phosphorylation by dissipating the proton gradient across the membrane. We have investigated regulation of the UCP3 gene in skeletal muscle and C2C12 muscle cells. UCP3 mRNA in mouse skeletal muscle is markedly increased by fasting and rapidly (within 4 h) decreased by re-feeding. Methyl palmoxirate, which inhibits fatty acid uptake by mitochondria and increases blood free fatty acids, prevents the fall in UCP3 message level induced by re-feeding. These findings suggest that fatty acid or a metabolite thereof, activates the UCP3 gene. Proof that fatty acid per se up-regulates UCP3 mRNA was obtained with C2C12 muscle cells in culture. Thus, oleic acid activated expression of UCP3 mRNA in differentiated C2C12 myotubes in a time and concentration-dependent manner. Moreover, BRL49653, a ligand for the nuclear hormone receptor PPARgamma induces expression of UCP3 mRNA suggesting that PPARgamma may regulate transcription of the UCP3 gene.


Assuntos
Proteínas de Transporte/genética , Ácidos Graxos/farmacologia , Mitocôndrias Musculares/metabolismo , Músculo Esquelético/efeitos dos fármacos , Tiazolidinedionas , Regulação para Cima , Animais , Linhagem Celular , Canais Iônicos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Mitocondriais , Músculo Esquelético/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Rosiglitazona , Tiazóis/farmacologia , Proteína Desacopladora 3
17.
Biochem J ; 340 ( Pt 2): 497-503, 1999 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10333495

RESUMO

A novel type of NADPH-dependent sepiapterin reductase, which catalysed uniquely the reduction of sepiapterin to l-threo-dihydrobiopterin, was purified 533-fold from the cytosolic fraction of Chlorobium tepidum, with an overall yield of 3%. The native enzyme had a molecular mass of 55 kDa and SDS/PAGE revealed that the enzyme consists of two subunits with a molecular mass of 26 kDa. The enzyme was optimally active at pH8.8 and 50 degrees C. Apparent Km values for sepiapterin and NADPH were 21 and 6.2 microM, respectively, and the kcat value was 5.0 s-1. Diacetyl could also serve as a substrate, with a Km of 4.0 mM. The inhibitory effects of N-acetylserotonin, N-acetyldopamine and melatonin were very weak. The Ki value of N-acetyldopamine was measured as 400 microM. The N-terminal amino acid sequence was revealed as Met-Lys-His-Ile-Leu-Leu-Ile-Thr-Gly-Ala-Xaa-Lys - Lys - Ile - Xaa - Arg - Ala - Ile - Ala - Leu - Glu - Xaa - Ala - Arg - Xaa-Xaa-Xaa-His-His-His-, which shared relatively high sequence similarity with other sepiapterin reductases.


Assuntos
Oxirredutases do Álcool/metabolismo , Biopterinas/análogos & derivados , Chlorobi/enzimologia , Oxirredutases do Álcool/antagonistas & inibidores , Oxirredutases do Álcool/química , Oxirredutases do Álcool/isolamento & purificação , Sequência de Aminoácidos , Animais , Biopterinas/biossíntese , Catálise , Chlorobi/metabolismo , Cromatografia Líquida de Alta Pressão , Inibidores Enzimáticos/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Cinética , Dados de Sequência Molecular , Peso Molecular , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Temperatura
18.
Biochim Biophys Acta ; 1427(2): 245-55, 1999 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-10216241

RESUMO

Cytosolic copper- and zinc-containing superoxide dismutase was purified 136-fold with an overall yield of 2.5% to apparent electrophoretic homogeneity from the dimorphic pathogenic fungus, Candida albicans. The molecular mass of the native enzyme was 39.4 kDa and the enzyme was composed of two identical subunits with a molecular mass of 19.6 kDa. The enzyme was stable in the range of pH 4.0-9.0 and up to 55 degrees C. The ultraviolet-visible absorption spectrum of the enzyme showed the absorption band of copper- and zinc-containing superoxide dismutase at 660 nm. The atomic absorption analysis revealed that the enzyme contained 0.87 g-atom of copper and 0.79 g-atom of zinc per mole of subunit. The N-terminal amino acid sequence alignments up to the 40th residue showed that copper- and zinc-containing superoxide dismutase from C. albicans has high similarity to other eukaryotic copper- and zinc-containing superoxide dismutases. The sod1 encoding copper- and zinc-containing superoxide dismutase has been cloned using a polymerase chain reaction fragment as a probe. Sequence analysis of the sod1 predicted a copper- and zinc-containing superoxide dismutase that contains 154 amino acids with a molecular mass of 16143 Da and displayed 79%, 69%, and 57% sequence identity to the homologues of Neurospora crassa, Saccharomyces cerevisiae, and bovine, respectively. The cloned sod1 contained an intron of 245 nucleotides, which was verified by reverse transcription-polymerase chain reaction.


Assuntos
Candida albicans/genética , Superóxido Dismutase/isolamento & purificação , Sequência de Aminoácidos , Sequência de Bases , Candida albicans/enzimologia , Clonagem Molecular , Cobre/análise , Citosol/enzimologia , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Peso Molecular , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Espectrofotometria , Superóxido Dismutase/química , Superóxido Dismutase-1 , Temperatura , Zinco/análise
19.
Biochim Biophys Acta ; 1426(3): 409-19, 1999 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-10076057

RESUMO

Mitochondrial manganese-containing superoxide dismutase was purified around 112-fold with an overall yield of 1.1% to apparent electrophoretic homogeneity from the dimorphic pathogenic fungus, Candida albicans. The molecular mass of the native enzyme was 106 kDa and the enzyme was composed of four identical subunits with a molecular mass of 26 kDa. The enzyme was not sensitive to either cyanide or hydrogen peroxide. The N-terminal amino acid sequence alignments (up to the 18th residue) showed that the enzyme has high similarity to the other eukaryotic manganese-containing superoxide dismutases. The gene sod2 encoding manganese-containing superoxide dismutase has been cloned using a product obtained from polymerase chain reaction. Sequence analysis of the sod2 predicted a manganese-containing superoxide dismutase that contains 234 amino acid residues with a molecular mass of 26173 Da, and displayed 57% sequence identity to the homologue of Saccharomyces cerevisiae. The deduced N-terminal 34 amino acid residues may serve as a signal peptide for mitochondrial translocation. Several regulatory elements such as stress responsive element and haem activator protein 2/3/4/5 complex binding sites were identified in the promoter region of sod2. Northern analysis with a probe derived from the cloned sod2 revealed a 0.94-kb band, which corresponds approximately to the expected size of mRNA deduced from sod2.


Assuntos
Candida albicans/genética , Genes Fúngicos , Manganês/análise , Superóxido Dismutase/genética , Sequência de Aminoácidos , Sequência de Bases , Candida albicans/enzimologia , Clonagem Molecular , Dados de Sequência Molecular , Peso Molecular , Alinhamento de Sequência , Superóxido Dismutase/química , Superóxido Dismutase/isolamento & purificação
20.
Bone ; 24(2): 135-7, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9951783

RESUMO

Osteoporosis is a disease that is strongly genetically influenced. However, the genes responsible for the disease are poorly defined. Recent data show that a G-T transition polymorphism of the Sp1 binding site at the collagen type I alpha1 gene (Sp1 polymorphism) is associated significantly with bone mineral density (BMD) and osteoporotic fracture in British women. To establish the association between the Sp1 genotypes and BMD in Korean women, we examined 200 healthy postmenopausal women of Korean ethnicity, ranging in age from 44 to 66 years (mean+/-SD: 54.7+/-5.3 years). PCR amplification using the same primers as those used previously, with enzyme digestion, revealed no restriction site in our samples. We also performed a single-strand conformational polymorphism (SSCP) analysis in 100 of the 200 samples and could not find any polymorphic sites in the PCR amplification region. Based on our study, the Sp1 polymorphism at the type I collagen alpha1 gene was not found in Korean women. Therefore, we suggest that the Sp1 polymorphism at the type I collagen alpha1 gene is absent or rare in Korean women. Based on the present findings, this polymorphism does not seem to be responsible for the entire genetic contribution to BMD.


Assuntos
Colágeno/genética , Polimorfismo Genético , Fator de Transcrição Sp1/metabolismo , Adulto , Idoso , Povo Asiático/genética , Sequência de Bases , Sítios de Ligação/genética , Densidade Óssea/genética , DNA/genética , DNA/metabolismo , Feminino , Humanos , Coreia (Geográfico) , Pessoa de Meia-Idade , Osteoporose/genética , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Polimorfismo Conformacional de Fita Simples
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