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1.
Nature ; 576(7785): 85-90, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31723266

RESUMO

Thermoelectric materials transform a thermal gradient into electricity. The efficiency of this process relies on three material-dependent parameters: the Seebeck coefficient, the electrical resistivity and the thermal conductivity, summarized in the thermoelectric figure of merit. A large figure of merit is beneficial for potential applications such as thermoelectric generators. Here we report the thermal and electronic properties of thin-film Heusler alloys based on Fe2V0.8W0.2Al prepared by magnetron sputtering. Density functional theory calculations suggest that the thin films are metastable states, and measurements of the power factor-the ratio of the Seebeck coefficient squared divided by the electrical resistivity-suggest a high intrinsic figure of merit for these thin films. This may arise from a large differential density of states at the Fermi level and a Weyl-like electron dispersion close to the Fermi level, which indicates a high mobility of charge carriers owing to linear crossing in the electronic bands.

2.
Phys Rev Lett ; 124(19): 192501, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32469564

RESUMO

An inelastic excitation and cluster-decay experiment ^{2}H(^{16}C,^{4}He+^{12}Be or ^{6}He+^{10}Be)^{2}H was carried out to investigate the linear-chain clustering structure in neutron-rich ^{16}C. For the first time, decay paths from the ^{16}C resonances to various states of the final nuclei were determined, thanks to the well-resolved Q-value spectra obtained from the threefold coincident measurement. The close-threshold resonance at 16.5 MeV is assigned as the J^{π}=0^{+} band head of the predicted positive-parity linear-chain molecular band with (3/2_{π}^{-})^{2}(1/2_{σ}^{-})^{2} configuration, according to the associated angular correlation and decay analysis. Other members of this band were found at 17.3, 19.4, and 21.6 MeV based on their selective decay properties, being consistent with the theoretical predictions. Another intriguing high-lying state was observed at 27.2 MeV which decays almost exclusively to ^{6}He+^{10}Be(∼6 MeV) final channel, corresponding well to another predicted linear-chain structure with the pure σ-bond configuration.

3.
Epidemiol Infect ; 148: e250, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-33046159

RESUMO

We analysed associations between exposure to nightlife businesses and severe acute respiratory syndrome coronavirus 2 PCR test results at a tertiary hospital in Tokyo between March and April 2020. A nightlife group was defined as those who had worked at or visited the businesses. We included 1517 individuals; 196 (12.9%) were categorised as the nightlife group. After propensity score matching, the proportion of positive PCR tests in the nightlife group was significantly higher than that in the non-nightlife group (nightlife, 63.8%; non-nightlife, 23.0%; P < 0.001). An inclusive approach to mitigate risks related to the businesses needs to be identified.


Assuntos
Betacoronavirus , Infecções por Coronavirus/transmissão , Pneumonia Viral/transmissão , Adulto , COVID-19 , Comércio , Infecções por Coronavirus/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/epidemiologia , SARS-CoV-2 , Tóquio/epidemiologia
4.
Eur J Neurol ; 26(9): 1205-1211, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30980575

RESUMO

BACKGROUND AND PURPOSE: Corticobasal syndrome (CBS) is pathologically characterized by tau deposits in neuronal and glial cells and by reactive astrogliosis. In several neurodegenerative disorders, 18 F-THK5351 has been observed to bind to reactive astrocytes expressing monoamine oxidase B. In this study, the aim was to investigate the progression of disease-related pathology in the brains of patients with CBS using positron emission tomography with 18 F-THK5351. METHODS: Baseline and 1-year follow-up imaging were acquired using magnetic resonance imaging and positron emission tomography with 18 F-THK5351 in 10 subjects: five patients with CBS and five age-matched normal controls (NCs). RESULTS: The 1-year follow-up scan images revealed that 18 F-THK5351 retention had significantly increased in the superior parietal gyrus of the patients with CBS compared with the NCs. The median increases in 18 F-THK5351 accumulation in the patients with CBS were 6.53% in the superior parietal gyrus, 4.34% in the precentral gyrus and 4.33% in the postcentral gyrus. In contrast, there was no significant increase in the regional 18 F-THK5351 retention in the NCs. CONCLUSIONS: Longitudinal increases in 18 F-THK5351 binding can be detected over a short interval in the cortical sites of patients with CBS. A monoamine oxidase B binding radiotracer could be useful in monitoring the progression of astrogliosis in CBS.


Assuntos
Aminopiridinas , Doenças dos Gânglios da Base/diagnóstico por imagem , Progressão da Doença , Tomografia por Emissão de Pósitrons , Quinolinas , Compostos Radiofarmacêuticos , Tauopatias/diagnóstico por imagem , Idoso , Aminopiridinas/farmacocinética , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Quinolinas/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética
6.
Hum Reprod ; 32(12): 2456-2464, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29077845

RESUMO

STUDY QUESTION: What are effects of androgen, estrogen and anti-Müllerian hormone (AMH), independent of FSH action, on the development and function of primate follicles from the preantral to small antral stage in vitro? SUMMARY ANSWER: Androgen and estrogen, but not AMH, promote follicle survival and growth in vitro, in the absence of FSH. However, their growth-promoting effects are limited to the preantral to early antral stage. WHAT IS KNOWN ALREADY: FSH supports primate preantral follicle development in vitro. Androgen and estrogen augment follicle survival and growth in the presence of FSH during culture. STUDY DESIGN SIZE, DURATION: Nonhuman primate model; randomized, control versus treatment groups. Rhesus macaque (n = 6) secondary follicles (n = 24 per animal per treatment group) were cultured for 5 weeks. PARTICIPANTS/MATERIALS, SETTING, METHODS: Follicles were encapsulated in 0.25% (w/v) alginate and cultured individually in modified alpha minimum essential media with (i) FSH (1 ng/ml; control), (ii) no FSH, (iii) no FSH + estradiol (E2; 100 pg/ml)/dihydrotestosterone (DHT; 50 ng/ml) and (iv) no FSH + AMH (50 ng/ml). In a second experiment, follicles were cultured with (i) FSH (1 ng/ml), (ii) no FSH, (iii) no FSH + E2 (1 ng/ml), (iv) no FSH + DHT (50 ng/ml) and (v) no FSH + E2/DHT. Follicle survival, antrum formation and growth pattern were evaluated. Progesterone (P4), E2 and AMH concentrations in culture media were measured. MAIN RESULTS AND THE ROLE OF CHANCE: In the first experiment, FSH deprivation significantly decreased (P < 0.05) follicle survival rates in the no FSH group (16 ± 5%), compared to CTRL (66 ± 9%). E2/DHT (49 ± 5%), but not AMH (27 ± 8%), restored follicle survival rate to the CTRL level. Similarly, antrum formation rates were higher (P < 0.05) in CTRL (56 ± 6%) and E2/DHT groups (54 ± 14%), compared to no FSH (0 ± 0%) and AMH (11 ± 11%) groups. However, follicle growth rate after antrum formation and follicle diameter at week 5 was reduced (P < 0.05) in the E2/DHT group (405 ± 25 µm), compared to CTRL (522 ± 29 µm). Indeed, the proportion of fast-grow follicles at week 5 was higher in CTRL (29% ± 5), compared to E2/DHT group (10 ± 3%). No fast-grow follicles were observed in no FSH and AMH groups. AMH levels at week 3 remained similar in all groups. However, media concentrations of P4 and E2 at week 5 were lower (P < 0.05, undetectable) in no FSH, E2/DHT and AMH groups, compared to CTRL (P4 = 93 ± 10 ng/ml; E2 = 4 ± 1 ng/ml). In the second experiment, FSH depletion diminished follicle survival rate (66 ± 8% in control versus 45 ± 9% in no FSH, P = 0.034). E2 plus DHT (31.5 ± 11%) or DHT alone (69 ± 9%) restored follicle survival rate to the control (FSH) level as expected. Also, E2 plus DHT or DHT alone improved antrum formation rate. However, in the absence of FSH, E2 plus DHT or DHT alone did not support growth, in terms of follicle diameter, or steroid (P4 or E2) production after the antral stage. LIMITATIONS REASONS FOR CAUTION: This study is limited to in vitro effects of E2, DHT and AMH during the interval from the secondary to small antral stage of macaque follicular development. In addition, the primate follicle pool is heterogeneous and differs between animals; therefore, even though only secondary follicles were selected, follicle growth and developmental outcomes might differ from one animal to another. WIDER IMPLICATIONS OF THE FINDINGS: This study provides novel information on the possible actions of estrogen and androgen during early follicular development in primates. Our results suggest that sequential exposure of preantral follicles to local factors, e.g. E2 and DHT, followed by gonadotropin once the follicle reaches the antral stage, may better mimic primate folliculogenesis in vivo. STUDY FUNDING/COMPETING INTEREST(S): Research reported in this publication was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Center for Translational Research on Reproduction and Infertility 5P50HD071836, and the NIH Primate Centers Program 8P510D011092. There are no conflicts of interest.


Assuntos
Androgênios/farmacologia , Hormônio Antimülleriano/farmacologia , Estrogênios/farmacologia , Hormônio Foliculoestimulante/farmacologia , Folículo Ovariano/efeitos dos fármacos , Animais , Sobrevivência Celular , Di-Hidrotestosterona/farmacologia , Estradiol/farmacologia , Feminino , Gonadotropinas/metabolismo , Técnicas In Vitro , Macaca mulatta , Modelos Animais , Oócitos/citologia , Ovário/metabolismo , Ovário/patologia , Progesterona/farmacologia
7.
Ann Oncol ; 27(7): 1257-66, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27052653

RESUMO

BACKGROUND: To examine the effect of the histology of carcinoma and sarcoma components on survival outcome of uterine carcinosarcoma. PATIENTS AND METHODS: A multicenter retrospective study was conducted to examine uterine carcinosarcoma cases that underwent primary surgical staging. Archived slides were examined and histologic patterns were grouped based on carcinoma (low-grade versus high-grade) and sarcoma (homologous versus heterologous) components, correlating to clinico-pathological demographics and outcomes. RESULTS: Among 1192 cases identified, 906 cases were evaluated for histologic patterns (carcinoma/sarcoma) with high-grade/homologous (40.8%) being the most common type followed by high-grade/heterologous (30.9%), low-grade/homologous (18.0%), and low-grade/heterologous (10.3%). On multivariate analysis, high-grade/heterologous (5-year rate, 34.0%, P = 0.024) and high-grade/homologous (45.8%, P = 0.017) but not low-grade/heterologous (50.6%, P = 0.089) were independently associated with decreased progression-free survival (PFS) compared with low-grade/homologous (60.3%). In addition, older age, residual disease at surgery, large tumor, sarcoma dominance, deep myometrial invasion, lymphovascular space invasion, and advanced-stage disease were independently associated with decreased PFS (all, P < 0.01). Both postoperative chemotherapy (5-year rates, 48.6% versus 39.0%, P < 0.001) and radiotherapy (50.1% versus 44.1%, P = 0.007) were significantly associated with improved PFS in univariate analysis. However, on multivariate analysis, only postoperative chemotherapy remained an independent predictor for improved PFS [hazard ratio (HR) 0.34, 95% confidence interval (CI) 0.27-0.43, P < 0.001]. On univariate analysis, significant treatment benefits for PFS were seen with ifosfamide for low-grade carcinoma (82.0% versus 49.8%, P = 0.001), platinum for high-grade carcinoma (46.9% versus 32.4%, P = 0.034) and homologous sarcoma (53.1% versus 38.2%, P = 0.017), and anthracycline for heterologous sarcoma (66.2% versus 39.3%, P = 0.005). Conversely, platinum, taxane, and anthracycline for low-grade carcinoma, and anthracycline for homologous sarcoma had no effect on PFS compared with non-chemotherapy group (all, P > 0.05). On multivariate analysis, ifosfamide for low-grade/homologous (HR 0.21, 95% CI 0.07-0.63, P = 0.005), platinum for high-grade/homologous (HR 0.36, 95% CI 0.22-0.60, P < 0.001), and anthracycline for high-grade/heterologous (HR 0.30, 95% CI 0.14-0.62, P = 0.001) remained independent predictors for improved PFS. Analyses of 1096 metastatic sites showed that carcinoma components tended to spread lymphatically, while sarcoma components tended to spread loco-regionally (P < 0.001). CONCLUSION: Characterization of histologic pattern provides valuable information in the management of uterine carcinosarcoma.


Assuntos
Carcinoma/patologia , Carcinossarcoma/patologia , Sarcoma/patologia , Neoplasias Uterinas/patologia , Adulto , Idoso , Carcinoma/tratamento farmacológico , Carcinoma/epidemiologia , Carcinoma/radioterapia , Carcinossarcoma/tratamento farmacológico , Carcinossarcoma/epidemiologia , Carcinossarcoma/radioterapia , Quimioterapia Adjuvante , Intervalo Livre de Doença , Feminino , Humanos , Ifosfamida , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Radioterapia Adjuvante , Estudos Retrospectivos , Sarcoma/tratamento farmacológico , Sarcoma/epidemiologia , Sarcoma/radioterapia , Análise de Sobrevida , Resultado do Tratamento , Neoplasias Uterinas/tratamento farmacológico , Neoplasias Uterinas/epidemiologia , Neoplasias Uterinas/radioterapia
8.
Phys Rev Lett ; 116(5): 052501, 2016 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-26894705

RESUMO

A candidate resonant tetraneutron state is found in the missing-mass spectrum obtained in the double-charge-exchange reaction ^{4}He(^{8}He,^{8}Be) at 186 MeV/u. The energy of the state is 0.83±0.65(stat)±1.25(syst) MeV above the threshold of four-neutron decay with a significance level of 4.9σ. Utilizing the large positive Q value of the (^{8}He,^{8}Be) reaction, an almost recoilless condition of the four-neutron system was achieved so as to obtain a weakly interacting four-neutron system efficiently.

10.
Br J Cancer ; 112(9): 1501-9, 2015 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-25867264

RESUMO

BACKGROUND: PD-L1 (programmed cell death 1 ligand 1) on tumour cells suppresses host immunity through binding to its receptor PD-1 on lymphocytes, and promotes peritoneal dissemination in mouse models of ovarian cancer. However, how PD-L1 expression is regulated in ovarian cancer microenvironment remains unclear. METHODS: The number of CD8-positive lymphocytes and PD-L1 expression in tumour cells was assessed in ovarian cancer clinical samples. PD-L1 expression and tumour progression in mouse models under conditions of altering IFN-γ signals was assessed. RESULTS: The number of CD8-positive cells in cancer stroma was very high in peritoneally disseminated tumours, and was strongly correlated to PD-L1 expression on the tumour cells (P<0.001). In mouse models, depleting IFNGR1 (interferon-γ receptor 1) resulted in lower level of PD-L1 expression in tumour cells, increased the number of tumour-infiltrating CD8-positive lymphocytes, inhibition of peritoneal disseminated tumour growth and longer survival (P=0.02). The injection of IFN-γ into subcutaneous tumours induced PD-L1 expression and promoted tumour growth, and PD-L1 depletion completely abrogated tumour growth caused by IFN-γ injection (P=0.01). CONCLUSIONS: Interferon-γ secreted by CD8-positive lymphocytes upregulates PD-L1 on ovarian cancer cells and promotes tumour growth. The lymphocyte infiltration and the IFN-γ status may be the key to effective anti-PD-1 or anti-PD-L1 therapy in ovarian cancer.


Assuntos
Antígeno B7-H1/metabolismo , Linfócitos T CD8-Positivos/imunologia , Interferon gama/farmacologia , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Neoplasias Peritoneais/metabolismo , Neoplasias Peritoneais/secundário , Animais , Apoptose , Western Blotting , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/patologia , Proliferação de Células , Progressão da Doença , Feminino , Citometria de Fluxo , Humanos , Técnicas Imunoenzimáticas , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/patologia , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/imunologia , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias Peritoneais/imunologia , Prognóstico , Células Tumorais Cultivadas , Microambiente Tumoral/efeitos dos fármacos , Regulação para Cima , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Osteoporos Int ; 26(7): 1959-63, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25792493

RESUMO

UNLABELLED: We evaluated the secondary fracture prevention in 1445 patients with distal radius fracture by trauma surgeons. The rate of patients with distal radius fracture who underwent bone mineral density (BMD) examination was low, suggesting that appropriate treatment for osteoporosis by trauma surgeons is not performed at present. INTRODUCTION: To clarify the status of osteoporosis interventions after distal radial fractures by trauma surgeons who play the main role in treatment for these fractures, we performed a survey involving multiple institutions in Japan. METHODS: We asked 155 board members of the Japanese Society for Fracture Repair for their cooperation and performed a survey in 48 institutions with which members who gave cooperation were affiliated. The subjects consisted of consecutive patients with distal radial fractures occurring between January and December 2012. The presence or absence of a diagnosis of osteoporosis and bone mineral density examination after fracture was investigated. RESULTS: A total of 1445 patients with distal radial fractures were evaluated in this study. BMD examination for diagnosis and treatment for osteoporosis after fracture was performed respectively in 126 (8.7 %) and 193 (13.4 %) of 1445 patients. Treatment for osteoporosis was performed in 93 (73.8 %) of 126 patients who underwent BMD examination after fracture and 100 (8.2 %) of 1219 who did not undergo BMD examination. Of the 126 patients who underwent BMD examination after fracture, 89 showed a BMD <80 % of the young adult mean as a criterion for the initiation of drug treatment for osteoporosis in Japan and 77 (86.5 %) of the 89 patients were treated with drugs. CONCLUSIONS: The rate of patients with distal radial fractures who underwent BMD examination was low, suggesting that appropriate treatment for osteoporosis by trauma surgeons is not performed at present.


Assuntos
Osteoporose/diagnóstico , Fraturas por Osteoporose/prevenção & controle , Fraturas do Rádio/cirurgia , Prevenção Secundária/normas , Absorciometria de Fóton/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea , Conservadores da Densidade Óssea/uso terapêutico , Competência Clínica , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas por Osteoporose/fisiopatologia , Fraturas do Rádio/fisiopatologia , Prevenção Secundária/métodos
12.
Phys Rev Lett ; 112(22): 223904, 2014 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-24949770

RESUMO

Dynamic wavelength conversion (DWC) is obtained by controlling copropagating slow-light signal and control pulse trajectories. Our method is based on the understanding that conventional resonator-based DWC can be generalized, and is linked to cross-phase modulation. Dispersion-engineered Si photonic crystal waveguides produce such slow-light pulses. Free carriers generated by two-photon absorption of the control pulse dynamically shift the signal wavelength. Matching the group velocities of the two pulses enhances the shift, elongating the interaction length. We demonstrate an extremely large wavelength shift in DWC (4.9 nm blueshift) for the signal wavelength. Although DWC is similar to the Doppler effect, we highlight their essential differences.

13.
J Infect Chemother ; 20(10): 593-601, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25172776

RESUMO

Staphylococcus (S.) aureus silently stays as our natural flora, and yet sometimes threatens our life as a tenacious pathogen. In addition to its ability to outwit our immune system, its multi-drug resistance phenotype makes it one of the most intractable pathogenic bacteria in the history of antibiotic chemotherapy. It conquered practically all the antibiotics that have been developed since 1940s. In 1961, the first MRSA was found among S. aureus clinical isolates. Then MRSA prevailed throughout the world as a multi-resistant hospital pathogen. In 1997, MRSA strain Mu50 with reduced susceptibility to vancomycin was isolated. Vancomycin-intermediate S. aureus (VISA), so named according to the CLSI criteria, was the product of adaptive mutation of S. aureus against vancomycin that had long been the last resort to MRSA infection. Here, we describe the genetic basis for the remarkable ability of S. aureus to acquire multi-antibiotic resistance, and propose a novel paradigm for future chemotherapy against the multi-resistant pathogens.


Assuntos
Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana Múltipla/genética , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/genética , Proteínas de Bactérias/genética , RNA Polimerases Dirigidas por DNA/genética , Humanos , Complexo de Reconhecimento de Origem/genética , Proteínas de Ligação às Penicilinas , Fenótipo , Staphylococcus aureus/efeitos dos fármacos
14.
J Anim Breed Genet ; 131(3): 227-36, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24906028

RESUMO

We demonstrated that supernodal techniques were more efficient than traditional methods for factorization and inversion of a coefficient matrix of mixed model equations (MME), which are often required in residual maximum likelihood (REML). Supernodal left-looking and inverse multifrontal algorithms were employed for sparse factorization and inversion, respectively. The approximate minimum degree or multilevel nested dissection was used for ordering. A new computer package, Yet Another MME Solver (YAMS), was developed and compared with FSPAK with respect to computing time and size of temporary memory for 13 test matrices. The matrices were produced by fitting animal models to dairy data and by using simulations from sire, sire-maternal grand sire, maternal and dominance models for phenotypic data and animal model for genomic data. The order of matrices ranged from 32,840 to 1,048,872. The YAMS software factorized and inverted the matrices up to 13 and 10 times faster than FSPAK, respectively, when an appropriate ordering strategy was applied. The YAMS package required at most 282 MB and 512 MB of temporary memory for factorization and inversion, respectively. Processing time per iteration in average information REML was reduced, using YAMS. The YAMS package is freely available on request by contacting the corresponding author.


Assuntos
Biologia Computacional/métodos , Estatística como Assunto/métodos , Algoritmos , Análise de Variância , Animais , Cruzamento , Bovinos , Indústria de Laticínios , Feminino , Funções Verossimilhança , Masculino , Software , Fatores de Tempo
15.
Phys Rev Lett ; 110(5): 053902, 2013 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-23414021

RESUMO

We demonstrate ultrafast delay tuning of a slow-light pulse with a response time <10 ps. This is achieved using two types of slow light: dispersion-compensated slow light for the signal pulse, and low-dispersion slow light to enhance nonlinear effects of the control pulse. These two types of slow light are generated simultaneously in Si lattice-shifted photonic crystal waveguides, arising from flat and straight photonic bands, respectively. The control pulse blueshifts the signal pulse spectrum, through dynamic tuning caused by the plasma effect of two-photon-absorption-induced carriers. This changes the delay by up to 10 ps only when the two pulses overlap within the waveguide and enables ultrafast tuning that is not limited by the carrier lifetime. Using this, we succeeded in tuning the delay of one target pulse within a pulse train with 12 ps intervals.

16.
Cell Biochem Funct ; 31(8): 652-9, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23339033

RESUMO

Simvastatin suppresses myoblast differentiation via inhibition of Rac GTPase, which is involved in the mevalonic acid pathway that produces cholesterol. Statins also inhibit adipogenic differentiation and receptor activator of NFκB ligand (RANKL) expression, possibly through the mevalonic acid pathway, although the involvement of that pathway and effector proteins in these cellular events has not been fully clarified. In the present study, we aimed to elucidate the mechanism of the effects of simvastatin on adipogenic differentiation and calcitriol-induced RANKL expression in bone marrow stromal ST2 cells. Adipogenesis and mRNA up-regulation of peroxisome proliferator-activated receptor γ and adipocyte fatty acid-binding protein were induced by troglitazone, and those events were efficiently inhibited by simvastatin. In addition, RANKL expression induced by calcitriol was abrogated by simvastatin in ST2 cells. The inhibitory effects of simvastatin were adequately compensated by the addition of either mevalonic acid or an intermediate of the mevalonic acid pathway, geranylgeranyl pyrophosphate, but not by another intermediate, farnesyl pyrophosphate. These findings suggest that protein geranylgeranylation is related to cellular differentiation in those two directions. Furthermore, inhibitor analysis demonstrated that Rac GTPase is involved in adipogenic differentiation, whereas Rho GTPase was found to be involved in RANKL expression. Taken together, the present findings suggest that geranylgeranylation of Rho family GTPase is involved in both adipogenesis and RANKL expression of stromal cells, while Rac GTPase is involved in adipogenesis and Rho GTPase in RANKL expression.


Assuntos
Adipócitos/efeitos dos fármacos , Adipogenia , Prenilação , Ligante RANK/biossíntese , Sinvastatina/farmacologia , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Adipócitos/citologia , Adipócitos/metabolismo , Adipogenia/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Ativação Enzimática , Ácido Mevalônico/metabolismo , Camundongos , Prenilação/efeitos dos fármacos , Ligante RANK/antagonistas & inibidores
17.
Nat Med ; 1(2): 129-34, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7585008

RESUMO

Although 13 years have passed since identification of human immunodeficiency virus-1 (HIV-1) as the cause of AIDS, we do not yet know how HIV kills its primary target, the T cell that carries the CD4 antigen. We and others have shown an increase in the percentage of apoptotic cells among circulating CD4+ (and CD8+) T cells of HIV-seropositive individuals and an increase in frequency of apoptosis with disease progression. However, it is not known if this apoptosis occurs in infected or uninfected T cells. We show here, using in situ labelling of lymph nodes from HIV-infected children and SIV-infected macaques, that apoptosis occurs predominantly in bystander cells and not in the productively infected cells themselves. These data have implications for pathogenesis and therapy, namely, arguing that rational drug therapy may involve combination agents targeting viral replication in infected cells and apoptosis of uninfected cells.


Assuntos
Apoptose , Infecções por HIV/virologia , Linfonodos/patologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Animais , Criança , Pré-Escolar , Feminino , Infecções por HIV/patologia , HIV-1/patogenicidade , Humanos , Linfonodos/virologia , Macaca , Masculino , RNA Mensageiro/análise , RNA Viral/análise , Síndrome de Imunodeficiência Adquirida dos Símios/patologia , Vírus da Imunodeficiência Símia/patogenicidade , Linfócitos T/virologia
18.
Nat Med ; 5(2): 194-203, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9930868

RESUMO

A substantial risk in using live attenuated, multiply deleted viruses as vaccines against AIDS is their potential to induce AIDS. A mutant of the simian immunodeficiency virus (SIV) with large deletions in nef and vpr and in the negative regulatory element induced AIDS in six of eight infant macaques vaccinated orally or intravenously. Early signs of immune dysfunction were seen in the remaining two offspring. Prolonged follow-up of sixteen vaccinated adult macaques also showed resurgence of chronic viremia in four animals: two of these developed early signs of disease and one died of AIDS. We conclude that this multiply deleted SIV is pathogenic and that human AIDS vaccines built on similar prototypes may cause AIDS.


Assuntos
Envelhecimento/imunologia , Vacinas contra a SAIDS , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vacinas Atenuadas/imunologia , Líquido Amniótico/virologia , Animais , Progressão da Doença , Feminino , Produtos do Gene nef/genética , Produtos do Gene vpr/genética , Imunidade nas Mucosas , Macaca mulatta , Masculino , Dados de Sequência Molecular , Gravidez , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/prevenção & controle , Vacinas contra a SAIDS/imunologia , Deleção de Sequência , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia
19.
Nat Med ; 6(2): 200-6, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10655110

RESUMO

Although maternal human immunodeficiency virus type 1 (HIV-1) transmission occurs during gestation, intrapartum and postpartum (by breast-feeding), 50-70% of all infected children seem to acquire HIV-1 shortly before or during delivery. Epidemiological evidence indicates that mucosal exposure is an important aspect of intrapartum HIV transmission. A simian immunodeficiency virus (SIV) macaque model has been developed that mimics the mucosal exposure that can occur during intrapartum HIV-1 transmission. To develop immunoprophylaxis against intrapartum HIV-1 transmission, we used SHIV-vpu+ (refs. 5,6), a chimeric simian-human virus that encodes the env gene of HIV-IIIB. Several combinations of human monoclonal antibodies against HIV-1 have been identified that neutralize SHIV-vpu+ completely in vitro through synergistic interaction. Here, we treated four pregnant macaques with a triple combination of the human IgG1 monoclonal antibodies F105, 2G12 and 2F5. All four macaques were protected against intravenous SHIV-vpu+ challenge after delivery. The infants received monoclonal antibodies after birth and were challenged orally with SHIV-vpu+ shortly thereafter. We found no evidence of infection in any infant during 6 months of follow-up. This demonstrates that IgG1 monoclonal antibodies protect against mucosal lentivirus challenge in neonates. We conclude that epitopes recognized by the three monoclonal antibodies are important determinants for achieving substantial protection, thus providing a rational basis for AIDS vaccine development.


Assuntos
Anticorpos Monoclonais/imunologia , HIV-1/imunologia , Imunidade nas Mucosas , Imunoglobulina G/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/imunologia , Animais , Quimera , Feminino , HIV-1/genética , Transmissão Vertical de Doenças Infecciosas , Macaca mulatta , Testes de Neutralização , Gravidez , Complicações Infecciosas na Gravidez , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/transmissão , Vírus da Imunodeficiência Símia/genética
20.
Exp Eye Res ; 91(2): 264-72, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20561980

RESUMO

The immunolocalization of the low density lipoprotein receptor-related protein 1 (LRP1) and its ligand alpha 2-Macroglobulin (alpha(2)M) was examined in tissues from human donor eyes of normal, diabetic and sickle cell disease subjects. Streptavidin alkaline phosphatase immunohistochemistry was performed with a mouse anti-human LRP1 and rabbit anti-human alpha(2)M antibodies. Retinal and choroidal blood vessels were labeled with mouse anti-human CD34 antibody in adjacent tissue sections. Mean scores for immunostaining from the pathological and control eyes were statistically compared. LRP1 immunoreactivity was very weak to negative in the neural retina of normal subjects except in scattered astrocytes. LRP1 expression in diabetic eyes was detected in the internal limiting membrane (ILM), astrocytes, inner photoreceptor matrix, choriocapillaris and choroidal stroma. The ligand alpha(2)M, however, was limited mainly to blood vessel walls, some areas of the inner nuclear layer (INL), photoreceptors, RPE-Bruch's membrane-choriocapillaris complex, intercapillary septa, and choroidal stroma. In sickle cell eyes, avascular and vascular retina as well as choroidal neovascularization (CNV) were analyzed. In avascular areas, LRP1 immunoreactivity was in innermost retina (presumably ILM, astrocytes, and Muller cells) and INL as well as RPE-Bruch's membrane-choriocapillaris complex and choroidal stroma. alpha(2)M was very weak in avascular peripheral retina compared to vascularized areas and limited to stroma in choroid. In contrast, in areas with CNV, LRP1 immunoreactivity was significantly decreased in overlying retina and in RPE-Bruch's membrane and choroidal stroma compared to the controls, while alpha(2)M was elevated in RPE-Bruch's membrane near CNV compared to normal areas in sickle cell choroid. The mean scores revealed that LRP1 and alpha(2)M in neural retina were significantly elevated in astrocytes and ILM in diabetic eyes (p < or = 0.05), whereas in sickle cell eyes scores were elevated in ILM and INL (p < or = 0.05). In addition, alpha(2)M immunoreactivity was in photoreceptors in both ischemic retinopathies. In choroid, the patterns of LRP1 and alpha(2)M expression were different and not coincident. This is the first demonstration of the presence of LRP1 and alpha(2)M in human proliferative retinopathies. Elevated LRP1 expression in sickle cell neural retina and diabetic inner retina and choroid suggests that LRP1 plays an important role in ischemic neovascular diseases.


Assuntos
Anemia Falciforme/metabolismo , Corioide/metabolismo , Retinopatia Diabética/metabolismo , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Retina/metabolismo , Neovascularização Retiniana/metabolismo , alfa-Macroglobulinas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Vasos Retinianos/metabolismo
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