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1.
Climacteric ; 24(2): 200-205, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32648773

RESUMO

OBJECTIVES: Emotion regulation processes, such as mindfulness, self-compassion, and acceptance, have been discussed as modifiable psychological factors related to middle-aged women's psychological distress and adjustment. Although these emotion regulation factors have been discussed separately, the question remains of which factors reflect the most variance in middle-aged women's health. Therefore, this study aimed to reveal the most relevant explanatory variable for middle-aged women's health: mindfulness, self-compassion, or acceptance. METHOD: A total of 200 middle-aged women completed self-reported measures of depressive symptoms, menopausal symptoms, physical quality of life, mental quality of life, and well-being. RESULTS: Correlation analysis showed that mindfulness, self-compassion, and acceptance were significantly associated with all variables of psychological distress and adjustment. Hierarchical multiple regression analysis revealed that acceptance significantly explained the most variance of depressive symptoms, menopausal symptoms, and mental quality of life. On the other hand, self-compassion significantly explained the greatest variance in well-being. CONCLUSIONS: These findings suggest that, for middle-aged women, 'acceptance' is an important explanatory variable of psychological distress and 'self-compassion' is an important variable of psychological adjustment.


Assuntos
Depressão/psicologia , Regulação Emocional , Empatia , Menopausa/psicologia , Autoimagem , Adaptação Psicológica , Feminino , Humanos , Japão , Pessoa de Meia-Idade , Atenção Plena , Angústia Psicológica , Qualidade de Vida/psicologia , Análise de Regressão , Autorrelato , Saúde da Mulher
2.
Ann Oncol ; 31(9): 1198-1206, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32522691

RESUMO

BACKGROUND: Acral melanoma (AM) is an epidemiologically and molecularly distinct entity that is underrepresented in clinical trials on immunotherapy in melanoma. We aimed to analyze the efficacy of anti-programmed cell death 1 (anti-PD-1) antibodies in advanced AM. PATIENTS AND METHODS: We retrospectively evaluated unresectable stage III or stage IV AM patients treated with an anti-PD-1 antibody in any line at 21 Japanese institutions between 2014 and 2018. The clinicobiologic characteristics, objective response rate (ORR, RECIST), survival estimated using Kaplan-Meier analysis, and toxicity (Common Terminology Criteria for Adverse Events 4.0.) were analyzed to estimate the efficacy of the anti-PD-1 antibodies. RESULTS: In total, 193 patients (nail apparatus, 70; palm and sole, 123) were included in the study. Anti-PD-1 antibody was used as first-line therapy in 143 patients (74.1%). Baseline lactate dehydrogenase (LDH) was within the normal concentration in 102 patients (52.8%). The ORR of all patients was 16.6% (complete response, 3.1%; partial response, 13.5%), and the median overall survival (OS) was 18.1 months. Normal LDH concentrations showed a significantly stronger association with better OS than abnormal concentrations (median OS 24.9 versus 10.7 months; P < 0.001). Although baseline characteristics were similar between the nail apparatus and the palm and sole groups, ORR was significantly lower in the nail apparatus group [6/70 patients (8.6%) versus 26/123 patients (21.1%); P = 0.026]. Moreover, the median OS in this group was significantly poorer (12.8 versus 22.3 months; P = 0.03). CONCLUSIONS: Anti-PD-1 antibodies have limited efficacy in AM patients. Notably, patients with nail apparatus melanoma had poorer response and survival, making nail apparatus melanoma a strong candidate for further research on the efficacy of novel combination therapies with immune checkpoint inhibitors.


Assuntos
Melanoma , Neoplasias Cutâneas , Humanos , Japão , Melanoma/tratamento farmacológico , Receptor de Morte Celular Programada 1 , Estudos Retrospectivos , Neoplasias Cutâneas/tratamento farmacológico
3.
Spinal Cord ; 53(3): 190-194, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25535154

RESUMO

OBJECTIVES: This study investigated the mechanisms inducing autonomic dysreflexia due to enhanced bladder-to-vascular reflexes in rats with spinal cord injury (SCI). METHODS: SCI was produced by the transection of the Th4-5 spinal cord in female Sprague-Dawley rats. At 4 weeks after SCI, changes in blood pressure during graded increases in intravesical pressure (20-60 cm H2O) were measured in spinal-intact (SI) and SCI rats under urethane anesthesia. In five animals, effects of C-fiber desensitization induced by intravesical application of resiniferatoxin (RTX), a TRPV1 agonist, on the bladder-to-vascular reflex were also examined. Nerve growth factor (NGF) levels of mucosa and detrusor muscle layers of the bladder were measured by enzyme-linked immunosorbent assay. The expression levels of TRPV1 and TRPA1 channels were also examined in laser captured bladder afferent neurons obtained from L6 DRG, which were labeled by DiI injected into the bladder wall. RESULTS: In SI and SCI rats, systemic arterial blood pressure was increased in a pressure-dependent manner during increases in the intravesical pressure, with significantly higher blood pressure elevation at the intravesical pressure of 20 cm H2O in SCI rats vs SI rats. The arterial blood pressure responses to bladder distention were significantly reduced by RTX-induced desensitization of C-fiber bladder afferent pathways. SCI rats had higher NGF protein levels in the bladder and higher TRPV1 and TRPA1 mRNA levels in bladder afferent neurons compared with SI rats. CONCLUSIONS: The bladder-to-vascular reflex induced by TRPV1-expressing C-fiber afferents during bladder distention is enhanced after SCI in association with increased expression of NGF in the bladder and TRP channels in bladder afferent neurons.

5.
Anim Genet ; 45(4): 517-23, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24754898

RESUMO

We evaluated genetic introgression from domesticated pigs into the Ryukyu wild boar (RWB) population on Iriomote Island based on their genetic structure and diversity. We used a combination of mitochondrial DNA D-loop region (596 bp) polymorphisms and 23 microsatellite markers. RWBs (n = 130) were collected from 18 locations on Iriomote Island and compared with 66 reference samples of European and Asian domestic pigs. We identified six distinct haplotypes, involving 22 single nucleotide polymorphisms (including one insertion) in the RWB population. The phylogenetic tree had two branches: the RWB group and domestic lineage. Fourteen of 130 RWBs (10.8%) belonged to the European domestic lineage, including 11 RWBs from the Panari Islands, northwest of Iriomote Main Island (IMI). The heterozygosity values, total number of alleles, number of effective alleles and polymorphism information content of the RWB groups were lower than those of the European domestic groups. The RWB population on IMI had a lower heterozygous deficiency index (FIS = 0.059) than did the other populations, which indicates that this population was more inbred. There was a large genetic distance (FST = 0.560) between RWBs on IMI and the Meishan populations. Structure analysis using the 23 microsatellite markers revealed that 16 RWBs had an admixture pattern between RWB and domesticated pig breeds. These results suggest that gene flow may have occurred from domestic pigs to RWBs and demonstrate that there was low genetic variation in the IMI population.


Assuntos
DNA Mitocondrial/genética , Fluxo Gênico , Repetições de Microssatélites , Polimorfismo Genético , Sus scrofa/genética , Animais , Japão , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/veterinária , Análise de Sequência de DNA/veterinária , Especificidade da Espécie , Sus scrofa/metabolismo
6.
Minerva Chir ; 67(3): 249-55, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22691829

RESUMO

AIM: The purpose of the present study was to determine whether in vivo electroporation could achieve selective blockade of apoptosis in a rat liver cirrhosis model. METHODS: A dimethylnitrosamine (DMN)-induced rat liver cirrhosis model was used. In vivo electroporation was performed after portal vein infusion of plasmid DNA. pFas-Fc plasmid DNA was used to block the apoptotic pathway. pUC/HGF and pCAGGS/EGFP were used as positive and negative controls, respectively. Liver collagen content was evaluated by hydroxyproline assay two weeks after gene transfer. Terminal deoxynucleotidyltransferase dUTP nick end-labeling was simultaneously performed in the liver to evaluate suppression of apoptosis. Survival analysis was performed using 10 rats that received the sFas gene, 10 that received the HGF gene, and 13 that received the GFP gene. RESULTS: The apoptotic cell index in the DMN-injected liver was significantly lower in rats that received the sFas gene compared with the negative control. The collagen content of the DMN-injected liver was also lower in rats that received the sFas gene compared with the negative control. There was no significant difference in the apoptotic cell index and collagen content of rats that received the sFas and HGF genes. Ten weeks after the initiation of DMN treatment, the survival rates with the sFas, HGF, and GFP genes were 56%, 100%, and 0, respectively. CONCLUSION: Selective blockade of apoptosis by in vivo electroporation-mediated gene transfer improved the apoptotic cell index, hydroxyproline content, and survival rate. Soluble Fas gene therapy using in vivo electroporation can be a safe and efficient therapy for liver cirrhosis in rats.


Assuntos
Apoptose/genética , DNA/administração & dosagem , Eletroporação , Técnicas de Transferência de Genes , Cirrose Hepática/genética , Cirrose Hepática/prevenção & controle , Animais , Infusões Intravenosas , Masculino , Plasmídeos , Veia Porta , Ratos , Ratos Sprague-Dawley
7.
Phys Med ; 82: 17-24, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33548793

RESUMO

The Kansai BNCT Medical Center has a cyclotron based epithermal neutron source for clinical Boron Neutron Capture Therapy. The system accelerates a proton to an energy of 30 MeV which strikes a beryllium target producing fast neutrons which are moderated down to epithermal neutrons for BNCT use. While clinical studies in the past have shown BNCT to be highly effective for malignant melanoma of the skin, to apply BNCT for superficial lesions using this system it is necessary to shift the thermal neutron distribution so that the maximum dose occurs near the surface. A dose distribution shifter was designed to fit inside the collimator to further moderate the neutrons to increase the surface dose and reduce the dose to the underlying normal tissue. Pure polyethylene was selected, and a Monte Carlo simulation was performed to determine the optimum thickness of the polyethylene slab. Compared with the original neutron beam, the shifter increased the thermal neutron flux at the skin by approximately 4 times. The measured and simulated central axis depth distribution and off axis distribution of the thermal neutron flux were found to be in good agreement. Compared with a 2 cm thick water equivalent bolus, a 26% increase in the thermal neutron flux at the surface was obtained, which would reduce the treatment time by approximately 29%. The DDS is a safe, simple and an effective tool for the treatment of superficial tumours for BNCT if an initially fast neutron beam requires moderation to maximise the thermal neutron flux at the tissue surface.


Assuntos
Terapia por Captura de Nêutron de Boro , Neoplasias , Humanos , Método de Monte Carlo , Nêutrons , Imagens de Fantasmas
8.
ESMO Open ; 6(6): 100325, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34839104

RESUMO

BACKGROUND: Anti-programmed cell death protein 1 (PD-1) antibody monotherapy (PD1) has led to favorable responses in advanced non-acral cutaneous melanoma among Caucasian populations; however, recent studies suggest that this therapy has limited efficacy in mucosal melanoma (MCM). Thus, advanced MCM patients are candidates for PD1 plus anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) combination therapy (PD1 + CTLA4). Data on the efficacy of immunotherapy in MCM, however, are limited. We aimed to compare the efficacies of PD1 and PD1 + CTLA4 in Japanese advanced MCM patients. PATIENTS AND METHODS: We retrospectively assessed advanced MCM patients treated with PD1 or PD1 + CTLA4 at 24 Japanese institutions. Patient baseline characteristics, clinical responses (RECIST), progression-free survival (PFS), and overall survival (OS) were estimated using Kaplan-Meier analysis, and toxicity was assessed to estimate the efficacy and safety of PD1 and PD1 + CTLA4. RESULTS: Altogether, 329 patients with advanced MCM were included in this study. PD1 and PD1 + CTLA4 were used in 263 and 66 patients, respectively. Baseline characteristics were similar between both treatment groups, except for age (median age 71 versus 65 years; P < 0.001). No significant differences were observed between the PD1 and PD1 + CTLA4 groups with respect to objective response rate (26% versus 29%; P = 0.26) or PFS and OS (median PFS 5.9 months versus 6.8 months; P = 0.55, median OS 20.4 months versus 20.1 months; P = 0.55). Cox multivariate survival analysis revealed that PD1 + CTLA4 did not prolong PFS and OS (PFS: hazard ratio 0.83, 95% confidence interval 0.58-1.19, P = 0.30; OS: HR 0.89, 95% confidence interval 0.57-1.38, P = 0.59). The rate of ≥grade 3 immune-related adverse events was higher in the PD1 + CTLA4 group than in the PD1 group (53% versus 17%; P < 0.001). CONCLUSIONS: First-line PD1 + CTLA4 demonstrated comparable clinical efficacy to PD1 in Japanese MCM patients, but with a higher rate of immune-related adverse events.


Assuntos
Melanoma , Neoplasias Cutâneas , Idoso , Antígeno CTLA-4 , Humanos , Imunoterapia/métodos , Japão , Melanoma/tratamento farmacológico , Estudos Retrospectivos
9.
J Cell Biol ; 146(2): 361-72, 1999 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-10427090

RESUMO

The Ral GTPase is activated by RalGDS, which is one of the effector proteins for Ras. Previous studies have suggested that Ral might function to regulate the cytoskeleton; however, its in vivo function is unknown. We have identified a Drosophila homologue of Ral that is widely expressed during embryogenesis and imaginal disc development. Two mutant Drosophila Ral (DRal) proteins, DRal(G20V) and DRal(S25N), were generated and analyzed for nucleotide binding and GTPase activity. The biochemical analyses demonstrated that DRal(G20V) and DRal(S25N) act as constitutively active and dominant negative mutants, respectively. Overexpression of the wild-type DRal did not cause any visible phenotype, whereas DRal(G20V) and DRal(S25N) mutants caused defects in the development of various tissues including the cuticular surface, which is covered by parallel arrays of polarized structures such as hairs and sensory bristles. The dominant negative DRal protein caused defects in the development of hairs and bristles. These phenotypes were genetically suppressed by loss of function mutations of hemipterous and basket, encoding Drosophila Jun NH(2)-terminal kinase kinase (JNKK) and Jun NH(2)-terminal kinase (JNK), respectively. Expression of the constitutively active DRal protein caused defects in the process of dorsal closure during embryogenesis and inhibited the phosphorylation of JNK in cultured S2 cells. These results indicate that DRal regulates developmental cell shape changes through the JNK pathway.


Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/embriologia , GTP Fosfo-Hidrolases/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Proteínas Quinases Ativadas por Mitógeno , Transdução de Sinais , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Linhagem Celular , Tamanho Celular , Clonagem Molecular , Drosophila melanogaster/enzimologia , Drosophila melanogaster/genética , Embrião não Mamífero/citologia , Embrião não Mamífero/enzimologia , Embrião não Mamífero/metabolismo , Desenvolvimento Embrionário , Ativação Enzimática , GTP Fosfo-Hidrolases/química , GTP Fosfo-Hidrolases/genética , Proteínas de Ligação ao GTP/química , Proteínas de Ligação ao GTP/genética , Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Genes de Insetos/genética , Genes de Insetos/fisiologia , Hibridização In Situ , Proteínas Quinases JNK Ativadas por Mitógeno , Dados de Sequência Molecular , Fenótipo , Fosforilação , Órgãos dos Sentidos/embriologia , Órgãos dos Sentidos/crescimento & desenvolvimento , Órgãos dos Sentidos/ultraestrutura , Asas de Animais/embriologia , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/ultraestrutura , Proteínas ral de Ligação ao GTP
10.
Science ; 269(5227): 1069-74, 1995 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-7652554

RESUMO

The high resolution three-dimensional x-ray structure of the metal sites of bovine heart cytochrome c oxidase is reported. Cytochrome c oxidase is the largest membrane protein yet crystallized and analyzed at atomic resolution. Electron density distribution of the oxidized bovine cytochrome c oxidase at 2.8 A resolution indicates a dinuclear copper center with an unexpected structure similar to a [2Fe-2S]-type iron-sulfur center. Previously predicted zinc and magnesium sites have been located, the former bound by a nuclear encoded subunit on the matrix side of the membrane, and the latter situated between heme a3 and CuA, at the interface of subunits I and II. The O2 binding site contains heme a3 iron and copper atoms (CuB) with an interatomic distance of 4.5 A; there is no detectable bridging ligand between iron and copper atoms in spite of a strong antiferromagnetic coupling between them. A hydrogen bond is present between a hydroxyl group of the hydroxyfarnesylethyl side chain of heme a3 and an OH of a tyrosine. The tyrosine phenol plane is immediately adjacent and perpendicular to an imidazole group bonded to CuB, suggesting a possible role in intramolecular electron transfer or conformational control, the latter of which could induce the redox-coupled proton pumping. A phenyl group located halfway between a pyrrole plane of the heme a3 and an imidazole plane liganded to the other heme (heme a) could also influence electron transfer or conformational control.


Assuntos
Cobre/análise , Complexo IV da Cadeia de Transporte de Elétrons/química , Heme/análogos & derivados , Magnésio/análise , Zinco/análise , Animais , Sítios de Ligação , Bovinos , Cristalização , Cristalografia por Raios X , Transporte de Elétrons , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Análise de Fourier , Heme/análise , Ligação de Hidrogênio , Mitocôndrias Cardíacas/enzimologia , Modelos Moleculares , Oxirredução , Oxigênio/metabolismo , Conformação Proteica , Estrutura Secundária de Proteína , Bombas de Próton
11.
Science ; 272(5265): 1136-44, 1996 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-8638158

RESUMO

The crystal structure of bovine heart cytochrome c oxidase at 2.8 A resolution with an R value of 19.9 percent reveals 13 subunits, each different from the other, five phosphatidyl ethanolamines, three phosphatidyl glycerols and two cholates, two hemes A, and three copper, one magnesium, and one zinc. Of 3606 amino acid residues in the dimer, 3560 have been converged to a reasonable structure by refinement. A hydrogen-bonded system, including a propionate of a heme A (heme a), part of peptide backbone, and an imidazole ligand of CuA, could provide an electron transfer pathway between CuA and heme a. Two possible proton pathways for pumping, each spanning from the matrix to the cytosolic surfaces, were identified, including hydrogen bonds, internal cavities likely to contain water molecules, and structures that could form hydrogen bonds with small possible conformational change of amino acid side chains. Possible channels for chemical protons to produce H2O, for removing the produced water, and for O2, respectively, were identified.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/química , Conformação Proteica , Sequência de Aminoácidos , Animais , Bovinos , Núcleo Celular/genética , Cobre/análise , Cristalografia por Raios X , Transporte de Elétrons , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Heme/análogos & derivados , Heme/análise , Ligação de Hidrogênio , Ferro/análise , Proteínas de Membrana/química , Mitocôndrias Cardíacas/genética , Modelos Moleculares , Dados de Sequência Molecular , Peso Molecular , Miocárdio/enzimologia , Nucleotídeos/metabolismo , Oxirredução , Oxigênio/metabolismo , Fosfolipídeos/análise , Estrutura Secundária de Proteína , Bombas de Próton , Água/metabolismo
12.
Science ; 280(5370): 1723-9, 1998 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-9624044

RESUMO

Crystal structures of bovine heart cytochrome c oxidase in the fully oxidized, fully reduced, azide-bound, and carbon monoxide-bound states were determined at 2.30, 2.35, 2.9, and 2.8 angstrom resolution, respectively. An aspartate residue apart from the O2 reduction site exchanges its effective accessibility to the matrix aqueous phase for one to the cytosolic phase concomitantly with a significant decrease in the pK of its carboxyl group, on reduction of the metal sites. The movement indicates the aspartate as the proton pumping site. A tyrosine acidified by a covalently linked imidazole nitrogen is a possible proton donor for the O2 reduction by the enzyme.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/química , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Miocárdio/enzimologia , Bombas de Próton , Animais , Ácido Aspártico/química , Ácido Aspártico/metabolismo , Azidas/metabolismo , Sítios de Ligação , Monóxido de Carbono/metabolismo , Bovinos , Cobre/química , Cobre/metabolismo , Cristalografia por Raios X , Heme/análogos & derivados , Heme/química , Heme/metabolismo , Ligação de Hidrogênio , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Ligantes , Metais/metabolismo , Modelos Químicos , Modelos Moleculares , Oxirredução , Oxigênio/metabolismo , Conformação Proteica , Tirosina/química , Tirosina/metabolismo
13.
Nat Commun ; 10(1): 4796, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31641138

RESUMO

Interneurons (INs) coordinate motoneuron activity to generate appropriate patterns of muscle contractions, providing animals with the ability to adjust their body posture and to move over a range of speeds. In Drosophila larvae several IN subtypes have been morphologically described and their function well documented. However, the general lack of molecular characterization of those INs prevents the identification of evolutionary counterparts in other animals, limiting our understanding of the principles underlying neuronal circuit organization and function. Here we characterize a restricted subset of neurons in the nerve cord expressing the Maf transcription factor Traffic Jam (TJ). We found that TJ+ neurons are highly diverse and selective activation of these different subtypes disrupts larval body posture and induces specific locomotor behaviors. Finally, we show that a small subset of TJ+ GABAergic INs, singled out by the expression of a unique transcription factors code, controls larval crawling speed.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila/fisiologia , Interneurônios/fisiologia , Fatores de Transcrição Maf Maior/metabolismo , Atividade Motora/fisiologia , Proteínas Proto-Oncogênicas/metabolismo , Animais , Animais Geneticamente Modificados , Drosophila/embriologia , Proteínas de Drosophila/genética , Embrião não Mamífero/fisiologia , Regulação da Expressão Gênica , Inativação Gênica , Larva/fisiologia , Locomoção/fisiologia , Fatores de Transcrição Maf Maior/genética , Proteínas Proto-Oncogênicas/genética , Raízes Nervosas Espinhais/fisiologia , Ácido gama-Aminobutírico/metabolismo
14.
J Environ Radioact ; 99(1): 211-7, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18171596

RESUMO

In a sediment core of Nishiyama reservoir at Nagasaki city, depth profiles of (240)Pu/(239)Pu isotopic ratio, (239+240)Pu and (137)Cs activities were determined. Sediments containing plutonium and (137)Cs, which were deposited immediately after a detonation of Nagasaki atomic bomb, were identified in the core. Observed below the sediments were macroscopic charcoals, providing evidence for initial deposit of the fallout of the Nagasaki atomic bomb. This is the first entire depositional records of plutonium and (137)Cs released from the Nagasaki atomic bomb together with those from atmospheric nuclear tests.


Assuntos
Radioisótopos de Césio/análise , Sedimentos Geológicos/química , Plutônio/análise , Poluentes Radioativos da Água/análise , Japão
15.
Curr Opin Struct Biol ; 7(4): 574-9, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9266181

RESUMO

During the past two years, the crystal structures of beef heart cytochrome c oxidase with 13 subunits and the bacterial enzyme with four subunits have been reported at atomic resolution, ushering in a new era for cytochrome c oxidase research. Different proton pumping mechanisms have been proposed for the two organisms.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/química , Miocárdio/enzimologia , Animais , Bovinos , Modelos Moleculares , Oxirredução , Bombas de Próton/metabolismo
16.
Appl Radiat Isot ; 65(4): 465-8, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17150366

RESUMO

The source of plutonium in sediments deposited at Nishiyama reservoir at Nagasaki was characterized by their (240)Pu/(239)Pu atom ratio. The average ratio was approximately 0.03, except in two layers. The main source of the plutonium was the Nagasaki atomic bomb. The plutonium continues to flow into the reservoir even now. The (240)Pu/(239)Pu atom ratios in two layers were higher than the average, which showed that plutonium in these layers were made of those of nuclear tests added to those of the atomic bomb.


Assuntos
Sedimentos Geológicos/química , Guerra Nuclear , Plutônio/análise , Poluentes Radioativos do Solo/análise , Radioisótopos de Césio/análise , Japão , Cinza Radioativa/análise
17.
Curr Opin Neurobiol ; 8(5): 582-6, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9811618

RESUMO

For more than a century, neuroscientists have gained insight into brain function by examining its complex patterns of connectivity. To achieve this, a wide variety of axon-tracing techniques have been employed to chart the projections of neurons. New, experimentally flexible, reporter-based tracers, many of which are fusion proteins designed to target axons and dendrites, are being developed and are assisting the molecular characterization of the nervous system.


Assuntos
Axônios/fisiologia , Encéfalo/citologia , Corantes , Genes Reporter , Animais , Vias Neurais
18.
J Neurosci ; 21(1): RC119, 2001 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11150355

RESUMO

The Drosophila Derailed (DRL) receptor tyrosine kinase (RTK) controls key guidance events in the developing nervous system and mesoderm. Like other members of the "related to tyrosine kinases" (RYK) subfamily of RTKs, DRL has several highly unusual amino acid substitutions within the catalytic domain, raising the possibility that members of this subfamily are catalytically inactive. To test the role of DRL kinase activity in vivo, we mutated the invariant lysine required for catalytic activity of known kinases and examined the ability of this mutant to function in two assays: a dominant gain-of-function axon switch assay in the nervous system and phenotypic rescue of muscle attachment in drl mutants. We show that this predicted kinase-deficient DRL mutant is capable of functioning in both assays. Our results indicate that DRL does not require kinase activity in vivo and suggest that members of the RYK subfamily of RTKs transduce signals unconventionally.


Assuntos
Proteínas de Drosophila , Receptores Proteína Tirosina Quinases/metabolismo , Animais , Animais Geneticamente Modificados , Axônios/metabolismo , Catálise , Domínio Catalítico/genética , Drosophila , Embrião não Mamífero/citologia , Embrião não Mamífero/inervação , Embrião não Mamífero/metabolismo , Cones de Crescimento/metabolismo , Desenvolvimento Muscular , Músculos/citologia , Músculos/metabolismo , Mutagênese Sítio-Dirigida , Neurônios/citologia , Neurônios/metabolismo , Receptores Proteína Tirosina Quinases/genética , Transdução de Sinais/fisiologia , Relação Estrutura-Atividade , Transgenes
19.
Biochim Biophys Acta ; 832(2): 220-3, 1985 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-2998474

RESUMO

A novel technique was employed to collect resonance Raman spectra of an oxygenated intermediate of cytochrome c oxidase. Instead of laser pulses of high peak power, which may cause photodissociation, a continuous wave laser and a mixed flow apparatus were used. An intermediate formed within 450 microseconds after the reaction of cytochrome c oxidase with molecular oxygen could be detected. From the spectra it could be deduced that the most likely candidate for the intermediate would be a transient oxygenated species having the Fe2+ - O2 or Fe4+ = O heme in cytochrome a3 and the Fe2+ heme in cytochrome a.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons , Animais , Monóxido de Carbono , Catálise , Bovinos , Oxigênio , Fotoquímica , Análise Espectral Raman
20.
J Mol Biol ; 278(1): 279-89, 1998 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-9571050

RESUMO

Until now and based on the success of the helix/coil transition theory it has been assumed that the alpha-helical propensities of the amino acids are position independent. This has been critical to derive the set of theoretical parameters for the 20 natural amino acids. Here, we have analyzed the behavior of several non-polar residues, Val, Ile, Leu, Met and Gly at the N-cap, at each position of the first helical turn and at a central helical position of a 16-residue peptide model system that starts with eight consecutive alanine residues. We have interpreted the results from these experiments with the model of the helix/coil transition (AGADIR), that indicates that the intrinsic helical propensity is position dependent. Gly, Val and Ile are more favorable at the first turn than in the middle of the alpha-helix, while for Leu and Met we observe the opposite behavior. The differences between the observed helical propensities are as large as 1.0 kcal/mol in some cases. Molecular modeling calculations using the ECEPP/2 force-field equipped with a hydration potential show that this effect can be explained by the combination of three factors: (a) the side-chains in the first helix turn are more solvent-exposed; (b) they have fewer intramolecular van der Waals' contacts; and (c) they posses higher configurational entropy than that in the central position of an alpha-helix. The position-dependent results of the calculations are in reasonable agreement with the experimental estimates and with the intrinsic propensities of the amino acids derived from the statistical analysis of the protein structure database.


Assuntos
Aminoácidos de Cadeia Ramificada/química , Glicina/química , Metionina/química , Peptídeos/química , Estrutura Secundária de Proteína , Algoritmos , Sequência de Aminoácidos , Aminoácidos , Dicroísmo Circular , Bases de Dados Factuais , Transferência de Energia , Isoleucina/química , Leucina/química , Modelos Moleculares , Dados de Sequência Molecular , Moldes Genéticos , Valina/química
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