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1.
Artigo em Inglês | MEDLINE | ID: mdl-30323038

RESUMO

Although the Sensititre Yeast-One (SYO) and Etest methods are widely utilized, interpretive criteria are not available for triazole susceptibility testing of Candida or Aspergillus species. We collected fluconazole, itraconazole, posaconazole, and voriconazole SYO and Etest MICs from 39 laboratories representing all continents for (method/agent-dependent) 11,171 Candida albicans, 215 C. dubliniensis, 4,418 C. glabrata species complex, 157 C.guilliermondii (Meyerozyma guilliermondii), 676 C. krusei (Pichia kudriavzevii), 298 C.lusitaniae (Clavispora lusitaniae), 911 C.parapsilosissensu stricto, 3,691 C.parapsilosis species complex, 36 C.metapsilosis, 110 C.orthopsilosis, 1,854 C.tropicalis, 244 Saccharomyces cerevisiae, 1,409 Aspergillus fumigatus, 389 A.flavus, 130 A.nidulans, 233 A.niger, and 302 A.terreus complex isolates. SYO/Etest MICs for 282 confirmed non-wild-type (non-WT) isolates were included: ERG11 (C. albicans), ERG11 and MRR1 (C. parapsilosis), cyp51A (A. fumigatus), and CDR2 and CDR1 overexpression (C. albicans and C. glabrata, respectively). Interlaboratory modal agreement was superior by SYO for yeast species and by the Etest for Aspergillus spp. Distributions fulfilling CLSI criteria for epidemiological cutoff value (ECV) definition were pooled, and we proposed SYO ECVs for S. cerevisiae and 9 yeast and 3 Aspergillus species and Etest ECVs for 5 yeast and 4 Aspergillus species. The posaconazole SYO ECV of 0.06 µg/ml for C. albicans and the Etest itraconazole ECV of 2 µg/ml for A. fumigatus were the best predictors of non-WT isolates. These findings support the need for method-dependent ECVs, as, overall, the SYO appears to perform better for susceptibility testing of yeast species and the Etest appears to perform better for susceptibility testing of Aspergillus spp. Further evaluations should be conducted with more Candida mutants.


Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Candida/efeitos dos fármacos , Triazóis/farmacologia , Aspergilose/tratamento farmacológico , Aspergilose/epidemiologia , Aspergilose/microbiologia , Aspergillus/classificação , Aspergillus/isolamento & purificação , Candida/classificação , Candida/isolamento & purificação , Candidíase/tratamento farmacológico , Candidíase/epidemiologia , Candidíase/microbiologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Fúngica , Fluconazol/farmacologia , Humanos , Hospedeiro Imunocomprometido , Itraconazol/farmacologia , Voriconazol/farmacologia
2.
Bull Am Meteorol Soc ; 97(7): 1229-1247, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29568125

RESUMO

The Earth System Prediction Suite (ESPS) is a collection of flagship U.S. weather and climate models and model components that are being instrumented to conform to interoperability conventions, documented to follow metadata standards, and made available either under open source terms or to credentialed users. The ESPS represents a culmination of efforts to create a common Earth system model architecture, and the advent of increasingly coordinated model development activities in the U.S. ESPS component interfaces are based on the Earth System Modeling Framework (ESMF), community-developed software for building and coupling models, and the National Unified Operational Prediction Capability (NUOPC) Layer, a set of ESMF-based component templates and interoperability conventions. This shared infrastructure simplifies the process of model coupling by guaranteeing that components conform to a set of technical and semantic behaviors. The ESPS encourages distributed, multi-agency development of coupled modeling systems, controlled experimentation and testing, and exploration of novel model configurations, such as those motivated by research involving managed and interactive ensembles. ESPS codes include the Navy Global Environmental Model (NavGEM), HYbrid Coordinate Ocean Model (HYCOM), and Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPS®); the NOAA Environmental Modeling System (NEMS) and the Modular Ocean Model (MOM); the Community Earth System Model (CESM); and the NASA ModelE climate model and GEOS-5 atmospheric general circulation model.

3.
Cerebellum ; 11(4): 917-24, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22351351

RESUMO

Limb ataxia of sudden onset is due to a vascular lesion in either the cerebellum or the brainstem (posterior circulation, PC, territory). This sign can involve both the upper and the lower limb (hemiataxia) or only one limb (monoataxia). The topographical correlates of limb ataxia have been studied only in brainstem strokes. Therefore, it is not yet known whether this sign is useful to localize the lesion within the entire cerebellar system, both the cerebellar hemisphere and the cerebellar brainstem pathways. Limb ataxia was semi-quantified according to the International Cooperative Ataxia Rating Scale in 92 consecutive patients with acute PC stroke. Limb ataxia was present in 70 patients. Four topographical patterns based on magnetic resonance imaging findings were identified: picaCH pattern (posterior inferior cerebellar artery infarct); scaCH pattern (superior cerebellar artery infarct); CH/CP pattern (infarct involving both the cerebellum and the brainstem cerebellar pathways); and CP pattern (infarct involving the brainstem cerebellar pathways). Hemiataxia was present in (47/70; 67.1%) and monoataxia in (23/70; 32.9%) of patients. Monoataxia involved the upper limb in (19/70; 27.1%) and the lower limb in (4/70; 5.7%) of patients. Limb ataxia usually localized the lesion ipsilaterally (picaCH, scaCH, CH/CP, and CP patterns involving the medulla and sometimes the pons) (53/70; 75.7%), but it might be due also to contralateral (CP pattern involving the pons or midbrain) (16/70; 22.9%) or bilateral lesions (1/70). Limb ataxia usually localizes the lesion ipsilaterally but the infarct might be sometimes contralateral. The occurrence of monoataxia may suggest that the cerebellar system is somatotopically organized.


Assuntos
Mapeamento Encefálico/métodos , Tronco Encefálico/patologia , Cerebelo/patologia , Acidente Vascular Cerebral/patologia , Adulto , Idoso , Ataxia/patologia , Tronco Encefálico/irrigação sanguínea , Cerebelo/irrigação sanguínea , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade
5.
Rev. costarric. cardiol ; 6(2): 73-74, mayo-ago. 2004. ilus
Artigo em Espanhol | LILACS | ID: lil-403810

RESUMO

Paciente de 75 años ingreso a unidad coronaria por fibrilación auricular paroxística complicada con ausencia de pulso radial y braquial izquierdo. Se realiza angiografía arterial de miembro superior y se observa oclusión arterial trombótica axilo-humeral. Se intento en forma no exitosa embolectomia, debido a que la imagen trombótica se encuentra distal al nacimiento de la arteria vertebral se realiza angioplastia y tromboaspiración. Post tratamiento inmediato se observa restitución del flujo radial, con recolección de trombos. Palabras Clave: trombosis, tromboaspiración, oclusión axilar, fibrilación auricular.


Assuntos
Humanos , Feminino , Idoso , Angioplastia , Fibrilação Atrial , Doença das Coronárias , Embolectomia , Inalação , Trombose , Costa Rica
6.
Med. intensiva (Madr., Ed. impr.) ; 27(7): 495-497, ago. 2003. ilus
Artigo em Es | IBECS | ID: ibc-26635

RESUMO

Presentamos el caso de una paciente de 32 años, que ingresa en urgencias por sufrir politraumatismo secundario a accidente automovilístico. Se le realiza una radiografía de tórax que evidencia ensanchamiento del mediastino con sospecha clínica de rotura aórtica torácica. Los estudios con tomografía axial computarizada y ecotransesofágico ponen de manifiesto rotura de aorta torácica, confirmada por angiografía de aorta descendente, que muestra una imagen compatible con seudoaneurisma. Debido a que la paciente persiste hipotensa, se decide tratamiento inmediato por vía endovascular, colocando un stent recubierto expandible con balón, con resultado favorable y sin complicaciones. En el seguimiento con tomografía axial computarizada con contraste, al mes, a los 6 meses y al año, no se observaron alteraciones de la prótesis ni fuga periprotésica (AU)


Assuntos
Adulto , Feminino , Humanos , Aorta Torácica/lesões , Stents , Ruptura Aórtica/diagnóstico , Ruptura Aórtica/cirurgia , Tomografia Computadorizada por Raios X , Acidentes de Trânsito , Ruptura Aórtica/etiologia
7.
Rev. costarric. cardiol ; 4(3): 39-42, sept.-dic. 2002. ilus
Artigo em Espanhol | LILACS | ID: lil-325296

RESUMO

Paciente de 32 años, que ingresa a la sala de guardia por sufrir poliltraumatismo secundario a accidente automovilístico. Se le realiza Rx de tórax que evidencia ensanchamietno de mediastino con sospecha clínica y por estudios con TAC y ecotransesofágico de rotura de aorta torácica, confirmada por angiografía de aorta descendente que muestra una imagen compatible con pseudoaneurisma. Debido a que la paciente persiste hipotensa, se decide tratamiento inmediato por vía endovascular, colocando un stent graft expandible con balón, con resultado exitoso y sin complicaciones. En el seguimiento con TAC con contraste al mes, a los 6 meses y al año, no se observaron alteraciones de la prótesis ni leaks peri protésico o re-estenosis. Palabras clave: Stent graft, ruptura traumática, pseudoaneurisma, accidente de tráfico.


Assuntos
Humanos , Adulto , Feminino , Acidentes de Trânsito , Aorta Torácica/cirurgia , Aorta Torácica/lesões , Procedimentos Cirúrgicos Cardiovasculares , Traumatologia , Procedimentos Cirúrgicos Vasculares , Argentina
8.
J Biomech ; 35(5): 585-94, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11955498

RESUMO

Any voluntary motion of the body causes an internal perturbation of balance. Load transfer during manual material handling may increase these perturbations. This study investigates effects of stance condition on postural control during lifting. Nineteen healthy subjects repeatedly lifted and lowered a load between a desk and a shelf. The base of support was varied between parallel and step stance. Ground reaction force and segmental kinematics were measured. Load transfer during lifting perturbed balance. In parallel stance postural response consisted of axial movements in the sagittal plane. Such strategy was accompanied by increased posterior shear forces after lift-off. Lifting in step stance provided extended support in anterior/posterior direction. The postural control mechanisms in the sagittal plane are less complex as compared to parallel stance. However, lifting in step stance was asymmetrical and thus accompanied by distinct lateral transfer of the body. Lateral shear forces were larger as compared to parallel stance. Both lifting techniques exhibit positive and negative aspects. We cannot recommend either one as being better in terms of postural control.


Assuntos
Remoção , Postura/fisiologia , Adulto , Fenômenos Biomecânicos , Humanos , Perna (Membro)/fisiologia , Masculino , Pessoa de Meia-Idade , Equilíbrio Postural/fisiologia , Suporte de Carga/fisiologia
9.
J Virol ; 74(8): 3781-92, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10729153

RESUMO

Virus infection of target cells can result in different biological outcomes: lytic infection, cellular transformation, or cell death by apoptosis. Cells respond to virus infection by the activation of specific transcription factors involved in cytokine gene regulation and cell growth control. The ubiquitously expressed interferon regulatory factor 3 (IRF-3) transcription factor is directly activated following virus infection through posttranslational modification. Phosphorylation of specific C-terminal serine residues results in IRF-3 dimerization, nuclear translocation, and activation of DNA-binding and transactivation potential. Once activated, IRF-3 transcriptionally up regulates alpha/beta interferon genes, the chemokine RANTES, and potentially other genes that inhibit viral infection. We previously generated constitutively active [IRF-3(5D)] and dominant negative (IRF-3 DeltaN) forms of IRF-3 that control target gene expression. In an effort to characterize the growth regulatory properties of IRF-3, we observed that IRF-3 is a mediator of paramyxovirus-induced apoptosis. Expression of the constitutively active form of IRF-3 is toxic, preventing the establishment of stably transfected cells. By using a tetracycline-inducible system, we show that induction of IRF-3(5D) alone is sufficient to induce apoptosis in human embryonic kidney 293 and human Jurkat T cells as measured by DNA laddering, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling assay, and analysis of DNA content by flow cytometry. Wild-type IRF-3 expression augments paramyxovirus-induced apoptosis, while expression of IRF-3 DeltaN blocks virus-induced apoptosis. In addition, we demonstrate an important role of caspases 8, 9, and 3 in IRF-3-induced apoptosis. These results suggest that IRF-3, in addition to potently activating cytokine genes, regulates apoptotic signalling following virus infection.


Assuntos
Apoptose , Proteínas de Ligação a DNA/metabolismo , Regulação Viral da Expressão Gênica , Respirovirus/fisiologia , Fatores de Transcrição/metabolismo , Caspases/metabolismo , Linhagem Celular , Proteínas de Ligação a DNA/genética , Ativação Enzimática , Humanos , Fator Regulador 3 de Interferon , Interferons/biossíntese , Células Jurkat , Respirovirus/patogenicidade , Fatores de Transcrição/genética , Transgenes
10.
Atherosclerosis ; 148(2): 327-35, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10657569

RESUMO

The purpose of this study was to investigate the effects of apolipoprotein (apo) E genotype on plasma apo E levels as well as serum total, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride, and glucose values in 734 middle-aged and elderly, female and male subjects. Apo E allele frequencies were similar to those reported in other Caucasian populations. After adjustment for medications, alcohol use, smoking, age, and body mass index, apo E genotype was noted to have significant effects on apo E, total cholesterol, LDL cholesterol, and glucose levels in females, and on apo E, LDL cholesterol, and HDL cholesterol levels, as well as the total cholesterol (TC)/HDL cholesterol ratio in males. Female and male subjects with the apo E4 allele had significantly (P<0.05) lower plasma apo E (25 and 15%) and higher LDL cholesterol levels (5 and 2%), while those with the apo E2 allele had significantly (P<0.05) higher apo E (32 and 27%) and lower LDL cholesterol levels (10 and 10%) than the apo E3/3 group. Moreover, female apo E4 carriers had significantly (P<0.05) lower glucose values (11%) than the apo E3/3 group. These data are consistent with the concept that, in addition to the well known effects of apo E genotype on LDL-C values, this locus plays a very significant role in modulating plasma apo E levels.


Assuntos
Apolipoproteínas E/sangue , Apolipoproteínas E/genética , Adulto , Idoso , Alelos , Apolipoproteína E4 , Glicemia/análise , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Feminino , Frequência do Gene , Genótipo , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Caracteres Sexuais
11.
Gene ; 237(1): 1-14, 1999 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-10524230

RESUMO

Interferons are a large family of multifunctional secreted proteins involved in antiviral defense, cell growth regulation and immune activation. Viral infection induces transcription of multiple IFN genes, a response that is in part mediated by the interferon regulatory factors (IRFs). The initially characterized members IRF-1 and IRF-2 are now part of a growing family of transcriptional regulators that has expanded to nine members. The functions of the IRFs have also expanded to include distinct roles in biological processes such as pathogen response, cytokine signaling, cell growth regulation and hematopoietic development. The aim of this review is to provide an update on the novel discoveries in the area of IRF transcription factors and the important roles of the new generation of IRFs--particularly IRF-3, IRF-4 and IRF-7.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Interferons/genética , Interferons/metabolismo , Fosfoproteínas/fisiologia , Fatores de Transcrição/fisiologia , Sequência de Aminoácidos , Animais , Apoptose/fisiologia , Divisão Celular/fisiologia , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Humanos , Sistema Imunitário/metabolismo , Fator Regulador 1 de Interferon , Fator Regulador 2 de Interferon , Fator Regulador 3 de Interferon , Fator Regulador 7 de Interferon , Fatores Reguladores de Interferon , Fator Gênico 3 Estimulado por Interferon , Fator Gênico 3 Estimulado por Interferon, Subunidade gama , Leucemia de Células T/metabolismo , Dados de Sequência Molecular , Fosfoproteínas/química , Proteínas Repressoras/metabolismo , Linfócitos T/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
12.
Clin Chem ; 45(7): 1039-46, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10388480

RESUMO

BACKGROUND: Increased plasma lipoprotein(a) [Lp(a)] concentrations have been reported to be an independent risk factor for coronary heart disease (CHD) in some prospective studies, but not in others. These inconsistencies may relate to a lack of standardization and the failure of some immunoassays to measure all apolipoprotein(a) isoforms equally. METHODS: We measured plasma Lp(a)-cholesterol [Lp(a)-C] in a Caucasian population of offspring and spouses of the Framingham Heart Study participants, using a lectin-based assay (LipoproTM). We compared the prevalence of increased Lp(a)-C to the presence of sinking pre-beta-lipoprotein (SPB). We also related Lp(a)-C concentrations to the prevalence of CHD risk in the entire population. RESULTS: The mean (+/- SD) Lp(a)-C concentration in the Framingham population (n = 3121) was 0.186 +/- 0.160 mmol/L, with no significant gender or age differences. The mean Lp(a)-C concentrations in the absence or presence of SPB were 0.158 +/- 0. 132 mmol/L and 0.453 +/- 0.220 mmol/L, respectively (P <0.0001). The mean Lp(a)-C concentration in men with CHD (n = 156) was 0.241 +/- 0. 204 mmol/L, which was significantly (P <0.001) higher, by 34%, than in controls. The odds ratio for CHD risk in men with Lp(a)-C >/=0. 259 mmol/L (>/=10 mg/dL), after adjusting for age, HDL-cholesterol, LDL-cholesterol, smoking, diabetes, blood pressure, and body mass index, was 2.293 (confidence interval, 1.55-3.94; P <0.0005). Lp(a)-C values correlated highly with a Lp(a)-mass immunoassay [ApotekTM Lp(a); r = 0.832; P <0.0001; n = 1000]. CONCLUSIONS: An increased Lp(a)-C value >/=0.259 mmol/L (>/=10 mg/dL) is an independent CHD risk factor in men with a relative risk of more than 2, but was inconclusive in women. Lp(a)-C measurements offer an alternative to Lp(a)-mass immunoassays and can be performed on automated analyzers.


Assuntos
Colesterol/sangue , Doença das Coronárias/sangue , Lipoproteína(a)/sangue , Fatores Etários , Colesterol/química , Doença das Coronárias/epidemiologia , Feminino , Humanos , Imunoensaio , Lipoproteína(a)/química , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Pós-Menopausa , Pré-Menopausa , Prevalência , Fatores de Risco , Fatores Sexuais
13.
J Biol Chem ; 274(19): 13010-6, 1999 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-10224051

RESUMO

Monocytic cells exhibit constitutive NF-kappaB activation upon infection with human immunodeficiency virus-1 (HIV-1). Because IkappaBbeta has been implicated in maintaining NF-kappaB.DNA binding, we sought to investigate whether IkappaBbeta was involved in maintaining persistent NF-kappaB activation in HIV-1-infected monocytic cell lines. IkappaBbeta was present in the nucleus of HIV-1-infected cells and participated in the ternary complex formation with NF-kappaB and DNA. In contrast to uninfected cells, the addition of recombinant glutathione S-transferase-IkappaBalpha protein to preformed NF-kappaB.DNA complexes from HIV-1-infected cell extracts did not completely dissociate the complexes, suggesting that IkappaBbeta may protect NF-kappaB complexes from IkappaBalpha-mediated dissociation. Immunodepletion of IkappaBbeta resulted in an NF-kappaB.DNA binding complex that was sensitive to IkappaBalpha-mediated dissociation, thus demonstrating the protective role of IkappaBbeta. In addition, co-transfection studies with an NF-kappaB-dependent reporter construct demonstrated that IkappaBbeta co-expression partially alleviated inhibition of NF-kappaB-mediated gene expression by IkappaBalpha, implying that IkappaBbeta can maintain transcriptionally active NF-kappaB.DNA complexes. Furthermore, constitutive phosphorylation of IkappaBalpha was observed. Immunoprecipitation of the IkappaB kinase (IKK) complex followed by in vitro analysis of kinase activity demonstrated that IKK was constitutively activated in HIV-1-infected myeloid cells. Thus, virus-induced constitutive IKK activation, coupled with the maintenance of a ternary NF-kappaB.DNA complex by IkappaBbeta, maintains persistent NF-kappaB activity in HIV-1-infected myeloid cells.


Assuntos
Núcleo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas I-kappa B , Sequência de Bases , Células da Medula Óssea/virologia , Linhagem Celular , DNA , Ativação Enzimática , HIV-1/isolamento & purificação , Humanos , Quinase I-kappa B , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Ligação Proteica , Isoformas de Proteínas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transcrição Gênica
14.
J Biol Chem ; 274(17): 11842-7, 1999 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-10207002

RESUMO

Some cold water marine fishes avoid cellular damage because of freezing by expressing antifreeze proteins (AFPs) that bind to ice and inhibit its growth; one such protein is the globular type III AFP from eel pout. Despite several studies, the mechanism of ice binding remains unclear because of the difficulty in modeling the AFP-ice interaction. To further explore the mechanism, we have determined the x-ray crystallographic structure of 10 type III AFP mutants and combined that information with 7 previously determined structures to mainly analyze specific AFP-ice interactions such as hydrogen bonds. Quantitative assessment of binding was performed using a neural network with properties of the structure as input and predicted antifreeze activity as output. Using the cross-validation method, a correlation coefficient of 0.60 was obtained between measured and predicted activity, indicating successful learning and good predictive power. A large loss in the predictive power of the neural network occurred after properties related to the hydrophobic surface were left out, suggesting that van der Waal's interactions make a significant contribution to ice binding. By combining the analysis of the neural network with antifreeze activity and x-ray crystallographic structures of the mutants, we extend the existing ice-binding model to a two-step process: 1) probing of the surface for the correct ice-binding plane by hydrogen-bonding side chains and 2) attractive van der Waal's interactions between the other residues of the ice-binding surface and the ice, which increases the strength of the protein-ice interaction.


Assuntos
Glicoproteínas/química , Glicoproteínas/metabolismo , Proteínas Anticongelantes , Glicoproteínas/genética , Modelos Moleculares , Mutagênese Sítio-Dirigida , Redes Neurais de Computação , Conformação Proteica , Relação Estrutura-Atividade
15.
Cytokine Growth Factor Rev ; 10(3-4): 235-53, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10647779

RESUMO

HIV infection leads to the progressive loss of CD4+ T cells and the near complete destruction of the immune system in the majority of infected individuals. High levels of viral gene expression and replication result in part from the activation of NF-kappaB transcription factors, which in addition to orchestrating the host inflammatory response also activate the HIV-1 long terminal repeat. NF-kappaB induces the expression of numerous cytokine, chemokine, growth factor and immunoregulatory genes, many of which promote HIV-1 replication. Thus, NF-kappaB activation represents a double edged sword in HIV-1 infected cells, since stimuli that induce an NF-kappaB mediated immune response will also lead to enhanced HIV-1 transcription. NF-kappaB has also been implicated in apoptotic signaling, protecting cells from programmed cell death under most circumstances and accelerating apoptosis in others. Therefore, activation of NF-kappaB can impact upon HIV-1 replication and pathogenesis at many levels, making the relationship between HIV-1 expression and NF-kappaB activation multi-faceted. This review will attempt to analyse the many faces and functions of NF-kappaB in the HIV-1 lifecycle.


Assuntos
Apoptose/fisiologia , HIV-1/metabolismo , NF-kappa B/metabolismo , Síndrome da Imunodeficiência Adquirida/fisiopatologia , Sequência de Aminoácidos , Animais , Infecções por HIV/patologia , Humanos , Quinase I-kappa B , Proteínas I-kappa B/metabolismo , Dados de Sequência Molecular , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo
16.
Virology ; 244(1): 27-38, 1998 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-9581775

RESUMO

HIV-1 infection of primary monocytic cells and myeloid cell lines results in sustained NF-kappaB activation. Recently, NF-kappaB induction has been shown to play a role in protecting cells from programmed cell death. In the present study, we sought to investigate whether constitutive NF-kappaB activity in chronically HIV-1-infected promonocytic U937 (U9-IIIB) and myeloblastic PLB-985 (PLB-IIIB) cells affects apoptotic signaling. TNFalpha and cycloheximide caused infected cells to undergo apoptosis more rapidly than parental U937 and PLB-985 cells. Inhibition of TNFalpha-induced NF-kappaB activation using the antioxidant N-acetylcysteine (NAC) resulted in increased apoptosis in both U937 and U9-IIIB cells, while preactivation of NF-kappaB with the non-apoptotic inducer IL-1beta caused a relative decrease in apoptosis. Inhibition of constitutive NF-kappaB activity in U9-IIIB and PLB-IIIB cells also induced apoptosis, suggesting that NF-kappaB protects cells from a persistent apoptotic signal. TNFalpha plus NAC treatment resulted in a marked decrease in Bcl-2 protein levels in HIV-1-infected cells, coupled with an increase in Bax protein compared to uninfected cells, suggesting that the difference in susceptibility to TNFalpha-induced apoptosis may relate to the differences in relative levels of Bcl-2 and Bax. The protective role of NF-kappaB in blocking TNFalpha- and HIV-1-induced apoptosis was supported by studies in Jurkat T cells engineered to express IkappaB alpha repressor mutants (TD-IkappaB) under the control of a tetracycline-responsive promoter. Cells underwent apoptosis in response to TNFalpha only when NF-kappaB activation was inhibited by TD-IkappaB expression. As was observed for the U9-IIIB cells, TNFalpha treatment also induced a marked decrease in Bcl-2 protein levels in TD-IkappaB expressing cells. These experiments demonstrate that apoptotic signaling is perturbed in HIV-1-infected U9-IIIB cells and indicate that NF-kappaB activation may play an additional protective role against HIV-1-induced apoptosis in myeloid cells.


Assuntos
Apoptose , HIV-1/fisiologia , Proteínas I-kappa B , Monócitos/virologia , NF-kappa B/metabolismo , Proteínas de Ligação a DNA/metabolismo , Humanos , Células Jurkat , Monócitos/patologia , Inibidor de NF-kappaB alfa , NF-kappa B/antagonistas & inibidores , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Células Tumorais Cultivadas , Proteína X Associada a bcl-2
17.
J Biol Chem ; 273(13): 7431-40, 1998 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-9516441

RESUMO

Human immunodeficiency virus (HIV-1) utilizes the NF-kappaB/Rel proteins to regulate transcription through NF-kappaB binding sites in the HIV-1 long terminal repeat (LTR). Normally, NF-kappaB is retained in the cytoplasm by inhibitory IkappaB proteins; after stimulation by multiple activators including viruses, IkappaBalpha is phosphorylated and degraded, resulting in NF-kappaB release. In the present study, we examined the effect of tetracycline-inducible expression of transdominant repressors of IkappaBalpha (TD-IkappaBalpha) on HIV-1 multiplication using stably selected Jurkat T cells. TD-IkappaBalpha was inducibly expressed as early as 3 h after doxycycline addition and dramatically reduced both NF-kappaB DNA binding activity and LTR-directed gene activity. Interestingly, induced TD-IkappaBalpha expression also decreased endogenous IkappaBalpha expression to undetectable levels by 24 h after induction, demonstrating that TD-IkappaBalpha repressed endogenous NF-kappaB-dependent gene transcription. TD-IkappaBalpha expression also sensitized Jurkat cells to tumor necrosis factor-induced apoptosis. De novo HIV-1 infection of Jurkat cells was dramatically altered by TD-IkappaBalpha induction, resulting in inhibition of HIV-1 multiplication, as measured by p24 antigen, reverse transcriptase, and viral RNA. Given the multiple functions of the NF-kappaB/IkappaB pathway, TD-IkappaBalpha expression may interfere with HIV-1 multiplication at several levels: LTR-mediated transcription, Rev-mediated export of viral RNA, inhibition of HIV-1-induced pro-inflammatory cytokines, and increased sensitivity of HIV-1-infected cells to apoptosis.


Assuntos
Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , HIV-1/fisiologia , Proteínas I-kappa B , NF-kappa B/antagonistas & inibidores , Proteínas Repressoras/farmacologia , Replicação Viral/efeitos dos fármacos , Sequência de Aminoácidos , Antibacterianos/farmacologia , Apoptose , DNA Viral/efeitos dos fármacos , DNA Viral/metabolismo , Proteínas de Ligação a DNA/biossíntese , Regulação para Baixo/efeitos dos fármacos , Doxiciclina/farmacologia , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Proteína do Núcleo p24 do HIV/metabolismo , Transcriptase Reversa do HIV/metabolismo , HIV-1/genética , Humanos , Células Jurkat , Dados de Sequência Molecular , Inibidor de NF-kappaB alfa , RNA Viral/efeitos dos fármacos , RNA Viral/metabolismo , Linfócitos T/virologia
18.
Biophys J ; 74(3): 1502-8, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9512046

RESUMO

It has been suggested that cooperative interactions between antifreeze proteins (AFPs) on the ice surfaces are required for complete inhibition of ice crystal growth. To test this hypothesis, a 7-kDa type III AFP was linked through its N-terminus to thioredoxin (12 kDa) or maltose-binding protein (42 kDa). The resultant 20-kDa and 50-kDa fusion proteins were larger in diameter than free AFP and thus precluded any extensive AFP-AFP contacts on the ice surface. Both fusion proteins were at least as active as free AFP at virtually all concentrations tested. By these criteria, AFPs function independently of each other and do not require specific intermolecular interactions to bind tightly to ice.


Assuntos
Glicoproteínas/química , Gelo , Conformação Proteica , Proteínas Anticongelantes , Sequência de Bases , Sítios de Ligação , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Congelamento , Genes Sintéticos , Glicoproteínas/metabolismo , Proteínas Ligantes de Maltose , Modelos Moleculares , Oligodesoxirribonucleotídeos , Ligação Proteica , Estrutura Secundária de Proteína , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Propriedades de Superfície , Tiorredoxinas/química , Tiorredoxinas/metabolismo
19.
J Mol Biol ; 275(3): 515-25, 1998 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-9466928

RESUMO

The interaction of proteins with ice is poorly understood and difficult to study, partly because ice is transitory and can present many binding surfaces, and partly because structures have been determined for only two ice-binding proteins. This paper focuses on one of these, a 66-residue antifreeze protein (AFP) from eel pout. The high resolution X-ray structure of this fish AFP demonstrated that the proposed ice-binding surface is remarkably flat for such a small protein. The residues on the planar surface thought to be involved in ice binding are restrained by hydrogen bonds or by tight packing of their side-chains. To probe the requirement for a flat binding surface, a conserved alanine in the center of the AFP planar surface was substituted with larger residues. Six alanine replacement mutants (Ala16 > Cys, Thr, Met, Arg, His and Tyr), designed to disrupt the planarity of the surface and sterically block binding to ice, were characterized by X-ray crystallography and compared with the wild-type AFP. In each case, the detail provided by these crystal structures has helped explain the effects of the mutation on antifreeze activity. The substitutions, Ala16 > His and Ala16 > Tyr, were large enough to shield Gln44, one of the putative ice-binding residues, contributing to their very low thermal hysteresis activity. In addition to sterically hindering the putative ice-binding site, the bulkier residues also caused shifts in the putative ice-binding residues owing to the tight packing of side-chains on the planar surface. This unexpected consequence of the mutations helps account for the severely reduced antifreeze activity. One explanation for residual antifreeze activity in some of the mutants lies in the possibility that AFPs have a role in shaping the site on the ice to which they bind. Thus, side-chain dislocations might be partially accommodated by ice that can freeze around them. It is evident that the disruption of the planarity, by introducing larger residues at the center of the proposed ice-binding site, is not the only factor responsible for the loss of antifreeze activity. There are multiple causes including positional change and steric blockage of some putative ice-binding residues.


Assuntos
Proteínas Anticongelantes Tipo III , Gelo , Mutagênese Sítio-Dirigida , Proteínas/química , Proteínas/genética , Alanina , Substituição de Aminoácidos , Animais , Cristalização , Cristalografia por Raios X , Cisteína , Enguias , Metionina , Modelos Moleculares , Ligação Proteica , Estrutura Secundária de Proteína , Proteínas/metabolismo , Estereoisomerismo , Água/química
20.
Harv Rev Psychiatry ; 6(4): 201-7, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-10370445

RESUMO

The objective of this study was to identify the dysphoric states that best characterize patients meeting criteria for borderline personality disorder and distinguish them from those in patients with other forms of personality disorder. One hundred forty-six patients with criteria-defined borderline personality disorder and 34 Axis II controls filled out the Dysphoric Affect Scale, a 50-item self-report measure that was designed for this purpose and has good internal consistency and test-retest reliability. Twenty-five dysphoric states (mostly affects) were found to be significantly more common among borderline patients than controls but nonspecific to borderline personality disorder. Twenty-five other dysphoric states (mostly cognitions) were found to be both significantly more common among borderline patients than controls and highly specific to borderline personality disorder. These states tended to fall into one of four clusters: (1) extreme feelings, (2) destructiveness or self-destructiveness, (3) fragmentation or "identitylessness," and (4) victimization. In addition, three of the 25 more-specific states (feeling betrayed, like hurting myself, and completely out of control), when occurring together, were particularly strongly associated with the borderline diagnosis. Equally important, overall mean Dysphoric Affect Scale scores correctly distinguished borderline personality disorder from other personality disorders in 84% of the subjects. Taken together, the results of this study suggest that the subjective pain of borderline patients may be both more pervasive and more multifaceted than previously recognized, and that the overall "amplitude" of this pain may be a particularly good marker for the borderline diagnosis.


Assuntos
Transtorno da Personalidade Borderline/psicologia , Tédio , Transtorno Depressivo/psicologia , Culpa , Adolescente , Adulto , Transtorno da Personalidade Borderline/diagnóstico , Doença Crônica , Transtorno Depressivo/diagnóstico , Humanos , Escalas de Graduação Psiquiátrica , Reprodutibilidade dos Testes , Estudos Retrospectivos , Autoavaliação (Psicologia)
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