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1.
Nat Commun ; 13(1): 1213, 2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35260556

RESUMO

V/A-ATPase is a motor protein that shares a common rotary catalytic mechanism with FoF1 ATP synthase. When powered by ATP hydrolysis, the V1 domain rotates the central rotor against the A3B3 hexamer, composed of three catalytic AB dimers adopting different conformations (ABopen, ABsemi, and ABclosed). Here, we report the atomic models of 18 catalytic intermediates of the V1 domain of V/A-ATPase under different reaction conditions, determined by single particle cryo-EM. The models reveal that the rotor does not rotate immediately after binding of ATP to the V1. Instead, three events proceed simultaneously with the 120˚ rotation of the shaft: hydrolysis of ATP in ABsemi, zipper movement in ABopen by the binding ATP, and unzipper movement in ABclosed with release of both ADP and Pi. This indicates the unidirectional rotation of V/A-ATPase by a ratchet-like mechanism owing to ATP hydrolysis in ABsemi, rather than the power stroke model proposed previously for F1-ATPase.


Assuntos
Adenosina Trifosfatases , Trifosfato de Adenosina , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Hidrólise , Modelos Moleculares , ATPases Translocadoras de Prótons/metabolismo , Rotação
2.
Braz J Med Biol Res ; 55: e11891, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35239782

RESUMO

The non-enzymatic antioxidant system protects blood components from oxidative damage and/or injury. Herein, plasma non-enzymatic antioxidant capacity after acute strenuous swimming exercise (Exe) and exercise until exhaustion (Exh) was measured in rats. The experiments were carried out in never exposed (Nex) and pre-exposed (Pex) groups. The Nex group did not undergo any previous training before the acute strenuous swimming test and the Pex group was submitted to daily swimming for 10 min in the first week and 15 min per day in the second week before testing. Plasma glucose, lactate, and pyruvate were measured and plasma total protein sulfhydryl groups (thiol), trolox equivalent antioxidant capacity (TEAC), ferric reducing ability of plasma (FRAP), and total radical-trapping antioxidant parameter (TRAP) levels were evaluated. There were marked increases in plasma lactate concentrations (Nex-Control 1.31±0.20 vs NexExe 4.16±0.39 vs NexExh 7.19±0.67) and in thiol (Nex-Control 271.9±5.6 vs NexExh 314.7±5.7), TEAC (Nex-Control 786.4±60.2 vs NexExh 1027.7±58.2), FRAP (Nex-Control 309.2±17.7 vs NexExh 413.4±24.3), and TRAP (Nex-Control 0.50±0.15 vs NexExh 2.6±0.32) levels after acute swimming and/or exhaustion. Also, there were increased plasma lactate concentrations (Pex-Control 1.39±0.15 vs PexExe 5.22±0.91 vs PexExh 10.07±0.49), thiol (Pex-Control 252.9±8.2 vs PexExh 284.6±6.7), FRAP (Pex-Control 296.5±15.4 vs PexExh 445.7±45.6), and TRAP (Pex-Control 1.8±0.1 vs PexExh 4.6±0.2) levels after acute swimming and/or exhaustion. Lactate showed the highest percent of elevation in the Nex and Pex groups. In conclusion, plasma lactate may contribute to plasma antioxidant defenses, and the TRAP assay is the most sensitive assay for assessing plasma non-antioxidant capacity after strenuous exercise.


Assuntos
Antioxidantes , Condicionamento Físico Animal , Animais , Antioxidantes/metabolismo , Estresse Oxidativo , Ácido Pirúvico , Ratos , Natação
3.
Braz. j. med. biol. res ; 55: e11891, 2022. graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1364558

RESUMO

The non-enzymatic antioxidant system protects blood components from oxidative damage and/or injury. Herein, plasma non-enzymatic antioxidant capacity after acute strenuous swimming exercise (Exe) and exercise until exhaustion (Exh) was measured in rats. The experiments were carried out in never exposed (Nex) and pre-exposed (Pex) groups. The Nex group did not undergo any previous training before the acute strenuous swimming test and the Pex group was submitted to daily swimming for 10 min in the first week and 15 min per day in the second week before testing. Plasma glucose, lactate, and pyruvate were measured and plasma total protein sulfhydryl groups (thiol), trolox equivalent antioxidant capacity (TEAC), ferric reducing ability of plasma (FRAP), and total radical-trapping antioxidant parameter (TRAP) levels were evaluated. There were marked increases in plasma lactate concentrations (Nex-Control 1.31±0.20 vs NexExe 4.16±0.39 vs NexExh 7.19±0.67) and in thiol (Nex-Control 271.9±5.6 vs NexExh 314.7±5.7), TEAC (Nex-Control 786.4±60.2 vs NexExh 1027.7±58.2), FRAP (Nex-Control 309.2±17.7 vs NexExh 413.4±24.3), and TRAP (Nex-Control 0.50±0.15 vs NexExh 2.6±0.32) levels after acute swimming and/or exhaustion. Also, there were increased plasma lactate concentrations (Pex-Control 1.39±0.15 vs PexExe 5.22±0.91 vs PexExh 10.07±0.49), thiol (Pex-Control 252.9±8.2 vs PexExh 284.6±6.7), FRAP (Pex-Control 296.5±15.4 vs PexExh 445.7±45.6), and TRAP (Pex-Control 1.8±0.1 vs PexExh 4.6±0.2) levels after acute swimming and/or exhaustion. Lactate showed the highest percent of elevation in the Nex and Pex groups. In conclusion, plasma lactate may contribute to plasma antioxidant defenses, and the TRAP assay is the most sensitive assay for assessing plasma non-antioxidant capacity after strenuous exercise.

4.
Braz J Med Biol Res, v. 55, e11891, fev. 2022
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-4243

RESUMO

The non-enzymatic antioxidant system protects blood components from oxidative damage and/or injury. Herein, plasma non-enzymatic antioxidant capacity after acute strenuous swimming exercise (Exe) and exercise until exhaustion (Exh) was measured in rats. The experiments were carried out in never exposed (Nex) and pre-exposed (Pex) groups. The Nex group did not undergo any previous training before the acute strenuous swimming test and the Pex group was submitted to daily swimming for 10 min in the first week and 15 min per day in the second week before testing. Plasma glucose, lactate, and pyruvate were measured and plasma total protein sulfhydryl groups (thiol), trolox equivalent antioxidant capacity (TEAC), ferric reducing ability of plasma (FRAP), and total radical-trapping antioxidant parameter (TRAP) levels were evaluated. There were marked increases in plasma lactate concentrations (Nex-Control 1.31±0.20 vs NexExe 4.16±0.39 vs NexExh 7.19±0.67) and in thiol (Nex-Control 271.9±5.6 vs NexExh 314.7±5.7), TEAC (Nex-Control 786.4±60.2 vs NexExh 1027.7±58.2), FRAP (Nex-Control 309.2±17.7 vs NexExh 413.4±24.3), and TRAP (Nex-Control 0.50±0.15 vs NexExh 2.6±0.32) levels after acute swimming and/or exhaustion. Also, there were increased plasma lactate concentrations (Pex-Control 1.39±0.15 vs PexExe 5.22±0.91 vs PexExh 10.07±0.49), thiol (Pex-Control 252.9±8.2 vs PexExh 284.6±6.7), FRAP (Pex-Control 296.5±15.4 vs PexExh 445.7±45.6), and TRAP (Pex-Control 1.8±0.1 vs PexExh 4.6±0.2) levels after acute swimming and/or exhaustion. Lactate showed the highest percent of elevation in the Nex and Pex groups. In conclusion, plasma lactate may contribute to plasma antioxidant defenses, and the TRAP assay is the most sensitive assay for assessing plasma non-antioxidant capacity after strenuous exercise.

5.
J Prev Alzheimers Dis ; 8(4): 495-502, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34585225

RESUMO

BACKGROUND: PET (positron emission tomography) and CSF (cerebrospinal fluid) provide the "ATN" (Amyloid, Tau, Neurodegeneration) classification and play an essential role in early and differential diagnosis of Alzheimer's disease (AD). OBJECTIVE: Biomarkers were evaluated in a Japanese multicenter study on cognitively unimpaired subjects (CU) and early (E) and late (L) mild cognitive impairment (MCI) patients. MEASUREMENTS: A total of 38 (26 CU, 7 EMCI, 5 LMCI) subjects with the age of 65-84 were enrolled. Amyloid-PET and FDG-PET as well as structural MRI were acquired on all of them, with an additional tau-PET with 18F-flortaucipir on 15 and CSF measurement of Aß1-42, P-tau, and T-tau on 18 subjects. Positivity of amyloid and tau was determined based on the positive result of either PET or CSF. RESULTS: The amyloid positivity was 13/38, with discordance between PET and CSF in 6/18. Cortical tau deposition quantified with PET was significantly correlated with CSF P-tau, in spite of discordance in the binary positivity between visual PET interpretation and CSF P-tau in 5/8 (PET-/CSF+). Tau was positive in 7/9 amyloid positive and 8/16 amyloid negative subjects who underwent tau measurement, respectively. Overall, a large number of subjects presented quantitative measures and/or visual read that are close to the borderline of binary positivity, which caused, at least partly, the discordance between PET and CSF in amyloid and/or tau. Nine subjects presented either tau or FDG-PET positive while amyloid was negative, suggesting the possibility of non-AD disorders. CONCLUSION: Positivity rate of amyloid and tau, together with their relationship, was consistent with previous reports. Multicenter study on subjects with very mild or no cognitive impairment may need refining the positivity criteria and cutoff level as well as strict quality control of the measurements.


Assuntos
Doença de Alzheimer , Biomarcadores/líquido cefalorraquidiano , Disfunção Cognitiva/diagnóstico , Tomografia por Emissão de Pósitrons , Sintomas Prodrômicos , Idoso , Idoso de 80 Anos ou mais , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Peptídeos beta-Amiloides/metabolismo , Carbolinas , Disfunção Cognitiva/líquido cefalorraquidiano , Humanos , Japão , Imageamento por Ressonância Magnética , Proteínas tau/líquido cefalorraquidiano , Proteínas tau/metabolismo
6.
Braz. j. med. biol. res ; 53(1): e8389, Jan. 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1055479

RESUMO

Photodynamic therapy (PDT) promotes cell death, and it has been successfully employed as a treatment resource for neuropathic complications of diabetes mellitus (T1DM) and hepatocellular carcinoma. The liver is the major organ involved in the regulation of energy homeostasis, and in pathological conditions such as T1DM, changes in liver metabolic pathways result in hyperglycemia, which is associated with multiple organic dysfunctions. In this context, it has been suggested that chlorophyll-a and its derivatives have anti-diabetic actions, such as reducing hyperglycemia, hyperinsulinemia, and hypertriglyceridemia, but these effects have not yet been proven. Thus, the biological action of PDT with chlorophyll-a on hepatic parameters related to energy metabolism and oxidative stress in T1DM Wistar rats was investigated. Evaluation of the acute effects of this pigment was performed by incubation of isolated hepatocytes with chlorophyll-a and the chronic effects were evaluated by oral treatment with chlorophyll-based extract, with post-analysis of the intact liver by in situ perfusion. In both experimental protocols, chlorophyll-a decreased hepatic glucose release and glycogenolysis rate and stimulated the glycolytic pathway in DM/PDT. In addition, there was a reduction in hepatic oxidative stress, noticeable by decreased lipoperoxidation, reactive oxygen species, and carbonylated proteins in livers of chlorophyll-treated T1DM rats. These are indicators of the potential capacity of chlorophyll-a in improving the status of the diabetic liver.


Assuntos
Animais , Masculino , Ratos , Clorofila/análogos & derivados , Fármacos Fotossensibilizantes/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Glicólise/efeitos dos fármacos , Fígado/fisiopatologia , Fotoquimioterapia , Clorofila/administração & dosagem , Ratos Wistar , Estresse Oxidativo/fisiologia , Diabetes Mellitus Experimental/patologia , Quimioterapia Combinada , Metabolismo Energético/efeitos dos fármacos , Glicólise/fisiologia , Fígado/patologia
7.
Braz J Med Biol Res ; 53(1): e8389, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31859908

RESUMO

Photodynamic therapy (PDT) promotes cell death, and it has been successfully employed as a treatment resource for neuropathic complications of diabetes mellitus (T1DM) and hepatocellular carcinoma. The liver is the major organ involved in the regulation of energy homeostasis, and in pathological conditions such as T1DM, changes in liver metabolic pathways result in hyperglycemia, which is associated with multiple organic dysfunctions. In this context, it has been suggested that chlorophyll-a and its derivatives have anti-diabetic actions, such as reducing hyperglycemia, hyperinsulinemia, and hypertriglyceridemia, but these effects have not yet been proven. Thus, the biological action of PDT with chlorophyll-a on hepatic parameters related to energy metabolism and oxidative stress in T1DM Wistar rats was investigated. Evaluation of the acute effects of this pigment was performed by incubation of isolated hepatocytes with chlorophyll-a and the chronic effects were evaluated by oral treatment with chlorophyll-based extract, with post-analysis of the intact liver by in situ perfusion. In both experimental protocols, chlorophyll-a decreased hepatic glucose release and glycogenolysis rate and stimulated the glycolytic pathway in DM/PDT. In addition, there was a reduction in hepatic oxidative stress, noticeable by decreased lipoperoxidation, reactive oxygen species, and carbonylated proteins in livers of chlorophyll-treated T1DM rats. These are indicators of the potential capacity of chlorophyll-a in improving the status of the diabetic liver.


Assuntos
Clorofila/análogos & derivados , Diabetes Mellitus Experimental/tratamento farmacológico , Glicólise/efeitos dos fármacos , Fígado/fisiopatologia , Estresse Oxidativo/efeitos dos fármacos , Fármacos Fotossensibilizantes/administração & dosagem , Animais , Clorofila/administração & dosagem , Diabetes Mellitus Experimental/patologia , Quimioterapia Combinada , Metabolismo Energético/efeitos dos fármacos , Glicólise/fisiologia , Fígado/patologia , Masculino , Estresse Oxidativo/fisiologia , Fotoquimioterapia , Ratos , Ratos Wistar
8.
QJM ; 113(9): 683, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31851356
9.
J Phys Condens Matter ; 30(45): 455001, 2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30265253

RESUMO

The Fe-on-Ti and Ti-on-Fe interfaces were studied experimentally by Mössbauer spectroscopy (MS), transmission electron microscopy (TEM) and x-ray reflectometry (XRR) on Ti/Fe/Ti trilayers grown on Si(1 1 1) substrates by vacuum evaporation. The nanoscale structure and composition were explored in cross sections using TEM, the layer structure and the interface widths by specular x-ray reflectometry. MS was applied to identify the interface alloy phases and to determine the pure and alloyed Fe layer fractions. The experimental results were compared with molecular dynamics (MD) simulations of layer growth on Fe or Ti underlayers of different orientations. The concentration distributions provided by MD simulations show an asymmetry at the interfaces in the layer growth direction. The transition is atomically sharp at the Ti-on-Fe interface for the (0 0 1) and (1 1 0) crystallographic orientations of the Fe underlayer, while it spreads over a few atomic layers for Fe(1 1 1) underlayer and for all studied Ti underlayer orientations at the Fe-on-Ti interface. MS and XRR data on Ti/Fe/Ti trilayers confirm the asymmetry between the bottom and top Fe interface, but the inferred interface widths considerable exceed those deduced from the MD simulations.

10.
Rev Sci Instrum ; 85(11): 11D813, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25430226

RESUMO

A Rogowski probe consisting of a small multi-layer Rogowski coil, five magnetic pick-up coils, and a Langmuir probe was developed to measure the local current density and its direction. It can be moved along the major radius and can be turned around its axis. This probe was used to measure the current density profile near the last closed flux surface of Ohmic plasmas in Tokyo Spherical Tokamak-2. The current density profile was measured successfully with a signal to noise ratio of greater than 20.

11.
Rev Sci Instrum ; 85(11): 11D846, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25430259

RESUMO

The multi-pass Thomson scattering (TS) scheme enables obtaining many photons by accumulating multiple TS signals. The signal-to-noise ratio (SNR) depends on the accumulation number. In this study, we performed multi-pass TS measurements for ohmically heated plasmas, and the relationship between SNR and the accumulation number was investigated. As a result, improvement of SNR in this experiment indicated similar tendency to that calculated for the background noise dominant situation.

12.
J Phys Condens Matter ; 26(35): 355502, 2014 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-25109352

RESUMO

A general rule of negative effective U(U(eff)) system caused by (i) exchange correlation and (ii) charge excitation mechanisms is proposed. Based on the general rule, we perform ab initio electronic structure calculations by generalized gradient approximation (GGA) + U method for hole-doped chalcopyrite CuFeS2 [Cu(+)(d(10))Fe(3+)(d(5))S(2-)(s(2)p(6))2]. It is found from our calculations that the hole-doped CuFeS2 has the negative U(eff) = -0.44 eV, where U(eff) ≡ E(N + 1) + E(N - 1) - 2E(N) < 0 and E(N) is the total energy of the hole-doped CuFeS2. The negative U(eff) is caused by the charge-excitation in the hole-doped Cu(2+)(d(9)) and S(-)(s(2)p(5)), and also caused by the exchange-correlation in the hole-doped Fe(4+)(d(4)). The strong attractive electron-electron interaction (U(eff) = -0.44 eV ∼ -5000 K) originates from the purely electronic mechanism. The closed shell of the d(10) electronic configuration is more stable than the d(9) electronic configuration, since the first excited state with the d(9)s(1) electronic configuration and the ground state with the d(10) electronic configuration are very close, then these two states repel very strongly through the second order perturbation. Therefore, the spin-polarized total energy curve for the hole-doped CuFeS2 shows the strong upward convexity with N - 1, N and N + 1 electronic configurations leading to the negative U(eff). The hole-doped paramagnetic and metallic CuFeS2 with the negative U(eff) may cause a possible high-Tc superconductor (Tc ∼ 1000 K, if 2Δ/kBTc ≈ 10 by assuming a strong coupling regime) because of the strong attractive electron-electron interactions (superconducting gap Δ ≈ |U(eff|) ∼ 5000 K). Finally, we propose a new computational materials design methodology to design ultra high-Tc superconductors by using three steps starting from the atomic number only.

13.
Rev Sci Instrum ; 85(5): 056103, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24880428

RESUMO

In multi-pass Thomson scattering (TS) scheme, a laser pulse makes multiple round trips through the plasma, and the effective laser energy is enhanced, and we can increase the signal-to-noise ratio as a result. We have developed a coaxial optical cavity in which a laser pulse is confined, and we performed TS measurements using the coaxial cavity in tokamak plasmas for the first time. In the optical cavity, the laser energy attenuation was approximately 30% in each round trip, and we achieved a photon number gain of about 3 compared with that obtained in the first round trip. In addition, the temperature measurement accuracy was improved by accumulating the first three round trip waveforms.

14.
Cytogenet Genome Res ; 142(2): 112-20, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24217467

RESUMO

Cichlid fishes in the African Great Lakes are known as a spectacular example of adaptive radiation in vertebrates. Four linkage maps have been constructed to identify the genes responsible for adaptation and speciation, and the genetic linkages of those genes are assumed to play an important role during adaptive evolution. However, it is difficult to analyze such linkages because the linkage groups of one species do not match well with those of the other species. Chromosome markers are a powerful tool for the direct identification of linkage homology between different species. We used information about the linkage map of the Lake Malawi cichlid (Labeotropheus fuelleborni/Metriaclima zebra) to isolate bacterial artificial chromosome (BAC) clones from the BAC library of Paralabidochromis chilotes, Lake Victoria. We identified 18 of 22 P. chilotes chromosomes by single- and multi-color BAC fluorescence in situ hybridization using 19 BAC clones. Comparative mapping with the chromosome markers of P. chilotes in Astatotilapia burtoni (2n = 40) from Lake Tanganyika revealed the chromosome rearrangements that have occurred in this lineage. These chromosome markers will be useful for delineating the process of genome and chromosome evolution in African species.


Assuntos
Mapeamento Cromossômico , Ciclídeos/genética , Ligação Genética/genética , África , Animais , Cromossomos Artificiais Bacterianos/genética , Biblioteca Gênica , Marcadores Genéticos/genética , Hibridização in Situ Fluorescente , Cariótipo
15.
AJNR Am J Neuroradiol ; 33(5): 890-5, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22241380

RESUMO

BACKGROUND AND PURPOSE: In PD, the neurodegenerative process begins in the brain stem and extends to the limbic system and finally into the cerebral cortex. We used diffusion tensor tractography to investigate the FA of the cingulate fiber tracts in patients with PD with and without dementia. MATERIALS AND METHODS: Fifteen patients with PD, 15 patients with PDD, and 15 age-matched healthy controls underwent diffusion tensor imaging with a 3T MR imager. Diffusion tensor tractography images of the anterior and posterior cingulate fiber tracts were generated. Mean diffusivity and FA were measured along the tractography of the anterior and posterior cingulate fiber tracts. One-way ANOVA with the Scheffé post hoc test was used to compare results among the groups. RESULTS: FA was significantly lower in patients with PDD than in healthy controls in both the anterior and the posterior cingulate fiber tracts (P = .003, P = .015) and significantly lower in patients with PD than in healthy controls (P = .003) in the anterior cingulate fiber tract. There were no significant mean diffusivity differences among the groups. MMSE and FA values of the anterior cingulate fiber tracts in patients with PDD were significantly correlated (r = 0.633, P < .05). CONCLUSIONS: The reduced FA in patients with PD and PDD might reflect neuropathologic changes such as Lewy body pathology in the cingulate fibers. This abnormality might contribute to the dementing process in PD.


Assuntos
Corpo Caloso/patologia , Demência/complicações , Demência/patologia , Imagem de Tensor de Difusão/métodos , Fibras Nervosas Mielinizadas/patologia , Doença de Parkinson/complicações , Doença de Parkinson/patologia , Idoso , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
Heredity (Edinb) ; 102(2): 182-9, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18813327

RESUMO

We evaluated the effects of seed- and pollen-mediated gene dispersal on genetic structure among Quercus salicina saplings. Parentage analysis using 10 microsatellite markers indicated that the 111 adult trees located within a 11.56 ha plot in the Tatera Forest Reserve, Japan, included only one parent of 44.2% and both parents of 40.7% of the 226 saplings located in a 1-ha core plot at its center. Coancestry (F(ij)) estimates indicated that there was strong genetic structure among the saplings. The numbers of pairs of full- and half-siblings were high among neighboring saplings, suggesting that there was strong maternal half-sibling family structure among the saplings around their seed parents, probably generated by the spatially limited seed dispersal and the small extent of overlapping seed shadows owing to the low density of adults. The frequencies also suggest that the maternal half-sibling families are interspersed with full-siblings, produced by correlated mating, probably because pollination frequency depends on the distance between parents. The frequencies of pairs of half-siblings decreased as the distance between saplings increased, but did not fall to zero even at distances up to the 90-95 m class, suggesting that paternal half-siblings originating from correlated paternity were widely distributed owing to extensive pollen flow. We separately examined the genetic structure for maternal and paternal alleles in the saplings. Unsurprisingly, very strong genetic structure was detected for maternal alleles. However, weak (but significant) genetic structure was also detected for paternal alleles. Therefore, pollen dispersal may affect the extent of genetic structure as well as seed dispersal.


Assuntos
Pólen/genética , Quercus/genética , Sementes/genética , Estruturas Genéticas , Variação Genética , Genótipo , Japão , Repetições de Microssatélites
17.
Oncogene ; 27(21): 2969-77, 2008 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-18059333

RESUMO

Germ-line mutations of the BRCA2 gene cause inherited susceptibility to breast and ovarian cancers. BRCA2 contains two nuclear localization signals, predominantly localizes in the nucleus and plays significant roles in DNA double-strand break repair. Recently, we reported that BRCA2 localizes to the centrosomes during the S and early M phases of the cell cycle. In this study, for the first time, we identified a functional nuclear export sequence (NES1; (1383)DLSDLTFLEVA(1393)) in BRCA2. The green fluorescent protein (GFP)-NES1 fusion protein was localized in the cytoplasm and could be blocked by the chromosomal region maintenance 1-specific export inhibitor leptomycin B. Mutation of a leucine residue in the NES1 motif to alanine (L1384A) resulted in both cytoplasmic and nuclear localization of the GFP-NES1 fusion protein and a nuclear accumulation of ectopic full-length BRCA2-FLAG. Moreover, treatment of cells with leptomycin B decreased centrosomal localization of BRCA2. Finally, by microinjection of an anti-BRCA2 antibody into the cytoplasm of HeLa S3 cells, we found that depletion of normal BRCA2 proteins in the cytoplasm leads to centrosome amplification and binucleated cells. Our results suggest that disruption of the NES function by genetic changes results in deregulation of BRCA2 export, which ultimately leads to centrosome disorder.


Assuntos
Proteína BRCA2/metabolismo , Centrossomo/metabolismo , Carioferinas/fisiologia , Sinais de Exportação Nuclear , Receptores Citoplasmáticos e Nucleares/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Células COS , Centrossomo/efeitos dos fármacos , Chlorocebus aethiops , Citoplasma/metabolismo , Primers do DNA , Ácidos Graxos Insaturados/farmacologia , Células HeLa , Humanos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Sinais de Exportação Nuclear/genética , Homologia de Sequência de Aminoácidos , Proteína Exportina 1
18.
Br J Cancer ; 96(2): 383-90, 2007 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-17242706

RESUMO

Recent studies have suggested that epigenetic inactivation of tumour-related genes by promoter methylation participates in the development of gastric cancer. We newly identified the frequently aberrant promoter methylation of alpha-1B-adrenergic receptor (ADRA1B) in colorectal cancer by methylation-sensitive representational difference analysis (MS-RDA) and examined the methylation status of the ADRA1B promoter in 34 paired samples of colorectal cancer and surrounding epithelial tissue, and 34 paired samples of gastric cancer and surrounding epithelial tissue. In colorectal cancers, only four of 34 (11.8%) tumours showed ADRA1B promoter methylation. In contrast, ADRA1B promoter methylation was detected in 24 of 34 (70.6%) gastric cancers and in 14 of 34 (41.2%) surrounding epithelial tissues. The frequency of ADRA1B promoter methylation was higher in gastric epithelial tissues with intestinal metaplasia (41.6%) than in those without intestinal metaplasia (25.0%). Reverse transcription-PCR detected reduced ADRA1B expression in 12 of 18 (66.7%) gastric cancers, and its promoter methylation was detected in 11 of these 12 (91.7%) gastric cancers with reduced ADRA1B expression. Thus, ADRA1B promoter is frequently methylated in gastric cancer. Our results suggest that the ADRA1B gene is an important tumour-related gene frequently involved in the development and progression of gastric cancer.


Assuntos
Metilação de DNA , Regiões Promotoras Genéticas , Receptores Adrenérgicos alfa 1/genética , Neoplasias Gástricas/genética , Sequência de Bases , Cromossomos Humanos Par 5 , Neoplasias Colorretais/genética , Primers do DNA , Humanos , Perda de Heterozigosidade , Reação em Cadeia da Polimerase Via Transcriptase Reversa
19.
Mol Ecol ; 14(14): 4469-78, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16313607

RESUMO

Since flowering often varies among years in wind-pollinated woody species, the genetic composition of pollen pools accepted by seed parents can differ between years. The interannual heterogeneity of pollen flow may be important for maintaining genetic diversity within populations because it can increase genetic variation within populations and the effective sizes of the populations. In this study we examined heterogeneity, using paternity analysis and analysis of molecular variance, in the genetic composition of pollen pools among different reproductive years for six Quercus salicina seed parents in an 11.56-ha plot in a temperate old-growth evergreen broadleaved forest. The genotypes at seven microsatellite loci were determined for 111 adult trees and 777 offspring of the six seed parents in 2-5 reproductive years. Genetic differentiation of pollen pools among different reproductive years for each seed parent was significant over all seed parents and for each of four seed parents that were analysed for more than 2 years, but not for either of the other two seed parents (analysed for 2 years). For both the pollen pools originating from inside the plot and those originating from outside it, genetic differentiation among different reproductive years for each seed parent was significant over all seed parents. However, among-year genetic differentiation in the pollen pools originating from within the plot was detected for all four of the seed parents that were analysed for more than 2 years, but for only one of the four in the pools originating from outside the plot. Genetic diversity (estimated as allelic richness and gene diversity) was higher for pollen pools over all reproductive years than for pollen pools in single years. These results indicate that the year-to-year genetic variation of pollen pools increases genetic diversity in offspring and is strongly affected by the variation in pollen parents within the plot because of their high pollination contributions. The high year-to-year variation in pollen parents within the plot and overall supports the hypothesis that the offspring produced across years represent a larger genetic neighbourhood.


Assuntos
Variação Genética , Genética Populacional , Pólen/genética , Quercus/genética , Análise de Variância , Primers do DNA , Genótipo , Japão , Repetições de Microssatélites/genética , Linhagem , Reprodução/genética , Fatores de Tempo
20.
Br J Dermatol ; 152(6): 1304-12, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15948997

RESUMO

BACKGROUND: In previous studies, etanercept significantly improved plaque psoriasis and was well tolerated. OBJECTIVES: To examine further the efficacy and safety of etanercept and to assess maintenance of treatment effect after dose reduction of etanercept. METHODS: In this multicentre 24-week study in the U.S.A., Canada and Western Europe, patients were at least 18 years old; had active, clinically stable plaque psoriasis involving at least 10% of body surface area; had a minimum Psoriasis Area and Severity Index (PASI) of 10 at screening; and had received or were a candidate to receive systemic psoriasis therapy or phototherapy. During the first 12 weeks of the study, patients were randomly assigned to receive by subcutaneous injection etanercept twice weekly (BIW) at a dose of 50 mg or 25 mg, or placebo BIW in a double-blind fashion. During the second 12 weeks, all patients received etanercept 25 mg BIW. The primary endpoint was a 75% or greater improvement from baseline in PASI (PASI 75) at 12 weeks. RESULTS: Five hundred and eighty-three subjects were randomized and received at least one dose of study drug. At week 12, a PASI 75 was achieved by 49% of patients in the etanercept 50 mg BIW group, 34% in the 25 mg BIW group, and 3% in the placebo group (P < 0.0001 for each etanercept group compared with placebo). At week 24 (after 12 weeks of open-label 25 mg etanercept BIW), a PASI 75 was achieved by 54% of patients whose dose was reduced from 50 mg BIW to 25 mg BIW, by 45% of patients in the continuous 25 mg BIW group, and by 28% in the group that received placebo followed by etanercept 25 mg BIW. Etanercept was well tolerated throughout the study. CONCLUSIONS: Etanercept provided clinically meaningful benefit to patients with chronic plaque psoriasis, with no apparent decrease in efficacy after dose reduction.


Assuntos
Imunoglobulina G/administração & dosagem , Imunossupressores/administração & dosagem , Psoríase/tratamento farmacológico , Receptores do Fator de Necrose Tumoral/administração & dosagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Etanercepte , Feminino , Humanos , Imunoglobulina G/uso terapêutico , Imunossupressores/uso terapêutico , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Receptores do Fator de Necrose Tumoral/uso terapêutico , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/uso terapêutico , Estatística como Assunto
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