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1.
Sci Total Environ ; 691: 483-498, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31325849

RESUMO

Road traffic poses negative externalities on society and represents a key challenge in sustainable transportation. However, the existing literature about the assessment of traffic externalities drawn on a common measure is scarce. This paper develops a sustainability indicator that integrates traffic-related externalities as means of traffic congestion, noise, greenhouse gases (GHG) and nitrogen oxides emissions, health impacts and road crash related costs, and adjusted to local contexts of vulnerability. Traffic, road crashes, acoustic and vehicle dynamic data were collected from one real-world intercity corridor pair comprising three alternative routes. The site-specific operations were characterized using a modeling platform of traffic, emissions, noise and air quality. A specific methodology is applied for each road traffic externality and translated in a single factor - external cost. The results indicated that road crashes presented the largest share in the partly rural/urban route while GHG emissions had the highest contribution in external costs for the highway routes. Also, the distribution of external cost component varied according to the type of road, mostly due to different levels of exposed inhabitants. This paper offers a line of research that produced a method for decision-makers with a reliable and flexible cost analysis aimed at reducing the negative impacts of road traffic. It also encourages the design of eco-traffic management policies considering the perspective of drivers, commuters and population.

2.
Struct Dyn ; 4(4): 044017, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28428974

RESUMO

Revealing the structure of complex biological macromolecules, such as proteins, is an essential step for understanding the chemical mechanisms that determine the diversity of their functions. Synchrotron based X-ray crystallography and cryo-electron microscopy have made major contributions in determining thousands of protein structures even from micro-sized crystals. They suffer from some limitations that have not been overcome, such as radiation damage, the natural inability to crystallize a number of proteins, and experimental conditions for structure determination that are incompatible with the physiological environment. Today, the ultra-short and ultra-bright pulses of X-ray free-electron lasers have made attainable the dream to determine protein structures before radiation damage starts to destroy the samples. However, the signal-to-noise ratio remains a great challenge to obtain usable diffraction patterns from a single protein molecule. With the perspective to overcome these challenges, we describe here a new methodology that has the potential to overcome the signal-to-noise-ratio and protein crystallization limits. Using a multidisciplinary approach, we propose to create ordered, two dimensional protein arrays with defined orientation attached on a self-assembled-monolayer. We develop a literature-based flexible toolbox capable of assembling different kinds of proteins on a functionalized surface and consider using a graphene cover layer that will allow performing experiments with proteins in physiological conditions.

3.
J Genet Couns ; 26(5): 999-1007, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28283917

RESUMO

Oncological Genetic Counselling (CGO) allows the identification of a genetic component that increases the risk of developing a cancer. Individuals' psychological reactions are influenced by both the content of the received information and the subjective perception of their own risk of becoming ill or being a carrier of a genetic mutation. This study included 120 participants who underwent genetic counselling for breast and/or ovarian cancer. The aim of the study was to examine the relation between their cancer risk perception and the genetic risk during CGO before receiving genetic test results, considering the influence of some psychological variables, in particular distress, anxiety and depression. Participants completed the following tools during a psychological interview: a socio-demographic form, Cancer Risk Perception (CRP) and Genetic Risk Perception (GRP), Hospital Anxiety and Depression Scale (HADS) and Distress Thermometer (DT). The data seem to confirm our hypothesis. Positive and significant correlations were found between the observed variables. Moreover, genetic risk perception determined an increase in depressive symptomatology and cancer risk perception led to an increase in anxious symptomatology, specifically in participants during cancer treatment. The present results suggest the importance of assessing genetic and cancer risk perception in individuals who undergo CGO, to identify those who are at risk of a decrease in psychological well-being and of developing greater psychological distress.


Assuntos
Ansiedade/psicologia , Neoplasias da Mama/psicologia , Aconselhamento Genético/psicologia , Predisposição Genética para Doença/psicologia , Neoplasias Ovarianas/psicologia , Adulto , Neoplasias da Mama/genética , Feminino , Humanos , Pessoa de Meia-Idade , Mutação , Neoplasias Ovarianas/genética , Percepção , Fatores de Risco , Estresse Psicológico/psicologia
4.
AIDS Care ; 15(3): 409-21, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12745399

RESUMO

To develop scales measuring major concerns about being HIV-positive and how people would cope with diagnosis, items were selected from the Ways of Coping Scale (Folkman et al., 1986)and generated by county health department HIV counsellors. Psychometric scale development involved two diverse samples of HIV test clients. Study I (health department, N = 272) yielded five Concerns with HIV scales and nine Coping with HIV scales. Factor structures did not differ between gay/bisexual men, heterosexual women or heterosexual men. In Study II (private non-profit gay-identified community HIV clinic, N = 227), LISREL confirmatory factor analyses cross-validated the Study I factor structures with no notable differences found. Some mean differences between genders and by sexual orientation were explained by different numbers of HIV-positive people known. Concern and Coping with HIV Scales (CCHIVS) are discussed for HIV/AIDS research and clinical use.


Assuntos
Adaptação Psicológica , Infecções por HIV/psicologia , Inquéritos e Questionários/normas , Adulto , Feminino , Humanos , Estudos Longitudinais , Masculino , Reprodutibilidade dos Testes , Estresse Psicológico
5.
Ann Oncol ; 13(8): 1264-74, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12181251

RESUMO

BACKGROUND: Burkitt's lymphoma (BL) is a rare and rapidly progressive form of B-cell non-Hodgkin's lymphoma. Cyclophosphamide, vincristine, doxorubicin, high-dose methotrexate (CODOX-M)/ifosfamide, etoposide and high-dose cytarabine (IVAC) is a highly effective alternating non-cross-resistant regimen developed by Magrath et al. (Magrath I., Adde M., Shad A. et al. J Clin Oncol 1996; 14: 925-934) at the US National Cancer Institute. The aim was to confirm these results in a larger, international, multi-centre study using International Prognostic Index-based criteria to assign prognostic groups, whilst slightly simplifying the protocol. PATIENTS AND METHODS: A phase II study where: (i) low risk (LR) patients were treated with three cycles of modified CODOX-M; and (ii) high risk (HR) patients received treatment with four cycles of alternating modified CODOX-M and IVAC chemotherapy. Target of 60 patients, fit for protocol treatment, from 16 to 60 years of age with locally diagnosed, non-HIV-related, non-organ-transplant-related BL. RESULTS: Results are given for 52 of 72 registered patients whose pathological eligibility was confirmed by central pathology review: 12 LR plus 40 HR. The majority of patients (n = 41) completed protocol treatment, but toxicity was severe, especially myelosuppression and mucositis. Overall, 2-year event-free survival (EFS) was 64.6% (95% CI 50.4% to 78.9%) and 2-year overall survival (OS) was 72.8% (95% CI 59.4% to 86.3%). For LR, 2-year EFS was 83.3% and OS was 81.5%. For HR, 2-year EFS was 59.5% and OS was 69.9%. CONCLUSIONS: This study confirms high cure rates with this CODOX-M/IVAC approach.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linfoma de Burkitt/tratamento farmacológico , Ciclofosfamida/uso terapêutico , Citarabina/uso terapêutico , Doxorrubicina/uso terapêutico , Etoposídeo/uso terapêutico , Ifosfamida/uso terapêutico , Metotrexato/uso terapêutico , Vincristina/uso terapêutico , Adulto , Linfoma de Burkitt/patologia , Avaliação de Medicamentos , Feminino , Humanos , L-Lactato Desidrogenase/metabolismo , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Fatores de Risco , Taxa de Sobrevida , Resultado do Tratamento , Reino Unido
6.
Nucleic Acids Res ; 29(16): 3377-84, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11504875

RESUMO

We studied the interaction between a synthetic peptide (sequence Ac-GXGGFGGXGGFXGGXGG-NH(2), where X = arginine, N(omega),N(omega)-dimethylarginine, DMA, or lysine) corresponding to residues 676-692 of human nucleolin and several DNA and RNA substrates using double filter binding, melting curve analysis and circular dichroism spectroscopy. We found that despite the reduced capability of DMA in forming hydrogen bonds, N(omega),N(omega)-dimethylation does not affect the strength of the binding to nucleic acids nor does it have any effect on stabilization of a double-stranded DNA substrate. However, circular dichroism studies show that unmethylated peptide can perturb the helical structure, especially in RNA, to a much larger extent than the DMA peptide.


Assuntos
Arginina/metabolismo , Glicina/metabolismo , Nitroarginina/metabolismo , Ácidos Nucleicos/metabolismo , Fosfoproteínas/química , Fosfoproteínas/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Dicroísmo Circular , DNA/química , DNA/genética , DNA/metabolismo , Bases de Dados como Assunto , Repetição Terminal Longa de HIV/genética , Humanos , Ligação de Hidrogênio , Metilação , Modelos Moleculares , Dados de Sequência Molecular , Nitroarginina/química , Conformação de Ácido Nucleico , Desnaturação de Ácido Nucleico , Ácidos Nucleicos/química , Ácidos Nucleicos/genética , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Fosfatos/química , Fosfatos/metabolismo , Ligação Proteica , RNA/química , RNA/genética , RNA/metabolismo , Termodinâmica , Nucleolina
7.
Psychooncology ; 10(3): 251-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11351377

RESUMO

This study investigates health-related quality of life (QoL) differences between 98 Portuguese and 109 US American outpatients with hematological malignancies. These two national groups of patients were characterized in terms of patients' QoL, and socio-demographic and clinical variables. Differences were found for several socio-demographic variables (race, marital and job status, urban residence, diagnosis, age, education, and household size). Portuguese patients reported better physical functioning, less bodily pain, more vitality, better social functioning, and better general QoL [as measured by Functional Living Index-Cancer (FLIC) total score] than American patients. Results were independent of demographic differences or mode of questionnaire administration.


Assuntos
Nível de Saúde , Leucemia/etnologia , Leucemia/psicologia , Qualidade de Vida , Adaptação Psicológica , Atitude Frente a Saúde , Comparação Transcultural , Cultura , Humanos , Portugal/epidemiologia , Inquéritos e Questionários , Estados Unidos/epidemiologia
8.
Oncogene ; 19(51): 5884-91, 2000 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-11127819

RESUMO

The protein Kinase A (PKA) pathway was found to selectively regulate the function of oncogenic but not non-oncogenic E6 proteins. High risk E6 proteins are phosphorylated at their Dlg/PDZ binding motif at the C-terminus by a PKA like activity. This PKA and PDZ binding module is found only for human PV, is strictly conserved in all the transforming HPVs and is absent in all the low risk HPV types. We present evidence of a conditional regulation of E6 induced degradation of Dlg. HPV18E6 positive but not HPV negative keratinocytes exhibit increased Dlg steady state levels under conditions of high PKA activity, with a concomitant increase in the presence of Dlg at tight junctions. In vitro binding experiments show that E6 phosphorylation by PKA reduces its binding to Dlg and molecular modelling can explain this observation in a structural context. E6 dependent degradation of Dlg in cells with high PKA levels is inhibited and this is dependent on phosphorylation of the PDZ binding site in E6. In contrast, the degradation of p53 induced by E6 is not affected by PKA. We propose a differential regulation of E6 for the ubiquitin mediated degradation of specific E6 target proteins.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas de Ligação a DNA , Proteínas Oncogênicas Virais/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas/metabolismo , Células 3T3/enzimologia , Células 3T3/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Sequência de Aminoácidos , Animais , Sítios de Ligação , Sequência Conservada , AMP Cíclico/metabolismo , Proteína 1 Homóloga a Discs-Large , Guanilato Quinases , Células HeLa , Humanos , Cinética , Proteínas de Membrana , Camundongos , Dados de Sequência Molecular , Proteínas Oncogênicas Virais/antagonistas & inibidores , Proteínas Oncogênicas Virais/genética , Papillomaviridae/genética , Papillomaviridae/metabolismo , Fosforilação , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Treonina/metabolismo , Ubiquitinas/metabolismo
9.
Health Care Women Int ; 21(7): 599-613, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11813768

RESUMO

A survey on factors related to breast cancer screening was completed by 179 U.S.-resident women of Mexican descent who were either Mexican born (n = 76) or U.S. born (n = 103). The U.S.-born women had significantly higher levels of income, education. and acculturation and were significantly more likely to be covered by health insurance and to receive health professional interventions such as breast self-exam (BSE) instruction. Accordingly, these U.S.-born women engaged in BSE more frequently and were more motivated to engage in other health behaviors. In comparison, the Mexican-born women reported significantly greater beliefs that breast cancer is a serious illness and that they were relatively more susceptible to this illness. For the Mexican-born women health locus of control was significantly more geared toward powerful others and chance factors. Factor differences suggest that Mexican-born women face more breast cancer screening barriers than the U.S.-born women of Mexican descent.


Assuntos
Atitude Frente a Saúde/etnologia , Neoplasias da Mama/diagnóstico , Emigração e Imigração , Comportamentos Relacionados com a Saúde/etnologia , Conhecimentos, Atitudes e Prática em Saúde , Programas de Rastreamento/psicologia , Programas de Rastreamento/estatística & dados numéricos , Americanos Mexicanos/psicologia , Mulheres/psicologia , Aculturação , Idoso , Idoso de 80 Anos ou mais , Autoexame de Mama/psicologia , Autoexame de Mama/estatística & dados numéricos , Escolaridade , Feminino , Humanos , Renda , Controle Interno-Externo , Americanos Mexicanos/educação , México/etnologia , Pessoa de Meia-Idade , Características de Residência , Inquéritos e Questionários , Texas , Mulheres/educação
10.
Psychooncology ; 8(6): 546-52, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10607987

RESUMO

Self reports of 49 outpatients with hematological cancers and matched dyad confidant reports about the patient, collected at a cancer treatment center in Lisbon, Portugal, were compared on the SF-36 quality of life (QOL) measure. These comparisons contrasted self reports and confidant reports of the 33 patients with an accompanying spouse/partner intimate confidant, and of the 16 patients with an accompanying non-intimate confidant. Intimate confidants gave lower SF-36 QOL ratings of patients' Social Functioning and Mental Health than those patients gave for themselves (p<0.05).


Assuntos
Cuidadores/psicologia , Neoplasias Hematológicas/psicologia , Qualidade de Vida , Papel do Doente , Adaptação Psicológica , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ajustamento Social
11.
J Clin Psychol ; 55(4): 381-3, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10348399

RESUMO

What does the future hold with regard to psychotherapy training? We posed that question to experts representing three important therapeutic approaches: Psychodynamic, Experiential, and Eclectic. In what follows we introduce this special section, provide our rationale for putting it together, and briefly highlight some interesting, substantive points made in the subsequent papers.


Assuntos
Psicoterapia/educação , Terapia Cognitivo-Comportamental/educação , Terapia Cognitivo-Comportamental/tendências , Previsões , Humanos , Transtornos Mentais/terapia , Psicoterapia/tendências , Ensino/tendências
12.
J Women Aging ; 10(2): 3-22, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9870038

RESUMO

The contribution of small life events to the prediction of general psychological distress was examined for 50 married and 21 recently widowed older women. These two groups were contrasted as having or not having experienced an uncontrollable major life stressor (i.e., the recent death of a spouse). Negative small life events (i.e., daily hassles) contributed above and beyond general demographic factors; conjugal bereavement status; social support; other, non-conjugal bereavement, major life events; and the interaction of these life events and social support in the prediction of general psychological distress. Results support assessing negative small life events as well as major life events for both married and recently widowed older women.


Assuntos
Acontecimentos que Mudam a Vida , Casamento/psicologia , Estresse Psicológico/psicologia , Viuvez/psicologia , Fatores Etários , Transtorno Depressivo/etiologia , Feminino , Humanos , Pessoa de Meia-Idade
13.
J Clin Oncol ; 16(8): 2796-802, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9704732

RESUMO

PURPOSE: The aim of this multicenter randomized study was to compare conventional therapy with conventional plus high-dose therapy (HDT) and autologous bone marrow transplantation (ABMT) as front-line treatment for poor-prognosis non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: Between October 1991 and June 1995, 124 patients, aged 15 to 60 years, with diffuse intermediate- to high-grade NHL (Working Formulation criteria), stages II bulky (> or = 10 cm), III, or IV were enrolled. Sixty-one patients were randomized to receive etoposide, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin (VACOP-B) for 12 weeks and cisplatin, cytarabine, and dexamethasone (DHAP) as a salvage regimen (arm A), and 63 to receive VACOP-B for 12 weeks plus HDT and ABMT (Arm B). RESULTS: There was no significant difference in terms of complete remissions (CRS) in the two groups: 75% in arm A, and 73% in arm B. The median follow-up observation time was 42 months. The 6-year survival probability was 65% in both arms. There was no difference in disease-free survival (DFS) or progression-free survival (PFS) between the two groups. DFS was 60% and 80% (P = .1) and PFS was 48% and 60% (P = .4) for arms A and B, respectively. Procedure feasibility was the major problem. In arm B, 29% of enrolled patients did not undergo HDT and ABMT. A statistical improvement in terms of DFS (P = .008) and a favorable trend in terms of PFS (P = .08) for intermediate-/high- plus high-risk group patients assigned to HDT and ABMT was observed. CONCLUSION: In this study, conventional chemotherapy followed by HDT and ABMT as front-line therapy seems no more successful than conventional treatment in terms of overall results. However, our results suggest that controlled studies of HDT plus ABMT should be proposed for higher risk patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Transplante de Medula Óssea , Linfoma não Hodgkin/terapia , Adolescente , Adulto , Bleomicina/administração & dosagem , Cisplatino/administração & dosagem , Terapia Combinada , Ciclofosfamida/administração & dosagem , Citarabina/administração & dosagem , Dexametasona/administração & dosagem , Doxorrubicina/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Humanos , Linfoma Difuso de Grandes Células B/mortalidade , Linfoma Difuso de Grandes Células B/terapia , Linfoma não Hodgkin/mortalidade , Masculino , Pessoa de Meia-Idade , Prednisona/administração & dosagem , Estudos Prospectivos , Terapia de Salvação , Taxa de Sobrevida , Vincristina/administração & dosagem
14.
Infect Immun ; 66(4): 1408-12, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9529060

RESUMO

Phagocytosis of Borrelia burgdorferi by human polymorphonuclear leukocytes triggers oxygen-dependent and -independent mechanisms of potentially cidal outcome. Nevertheless, no factor or process has yet been singled out as being borreliacidal. We have studied the B. burgdorferi-killing ability of the myeloperoxidase-H2O2-chloride system and that of primary and secondary granule components in an in vitro assay. We found that neither secondary granule acid extracts nor the chlorinating system could kill these microorganisms, while primary granule extracts were effective. The Borrelia-killing factor was purified to homogeneity and demonstrated to be elastase. Its cidal activity was found to be independent of its proteolytic activity.


Assuntos
Atividade Bactericida do Sangue , Grupo Borrelia Burgdorferi/imunologia , Grânulos Citoplasmáticos/enzimologia , Elastase de Leucócito/fisiologia , Neutrófilos/enzimologia , Sequência de Aminoácidos , Humanos , Dados de Sequência Molecular , Neutrófilos/imunologia , Oxigênio/farmacologia
15.
J Pept Res ; 50(1): 65-72, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9273889

RESUMO

We report here the total synthesis of the alpha-amylase inhibitor (AAI), a 32-residue-long peptide with three disulfide bridges, isolated from amaranth seeds (Chagolla-Lopez, A., Blanco-Labra, A., Patthy, A., Sanchez, R. & Pongor S. (1994) J. Biol. Chem. 269, 23675-23680). The synthesis was carried out using a stepwise solid-phase approach based on the Fmoc/t-Bu chemistry, combined with the S-acetamidomethyl protection for cysteines. The linear, reduced peptide was obtained after two reduction steps, using 1,4-dithio-DL-threitol and tri(2-carboxyethyl)phosphine hydrochloride in basic and acidic conditions, respectively. Disulfide bridges were formed by oxidative folding in a cystine/cysteine redox buffer, these conditions were found superior to air oxidation and to glutathione-catalyzed oxidative folding. The physiochemical and enzyme inhibitory properties of synthetic AAI were found identical with those of natural product. Several orthogonal protection schemes proved unsuccessful in obtaining a biologically active product.


Assuntos
Cisteína/química , Cistina/química , Inibidores Enzimáticos/síntese química , Magnoliopsida/química , Proteínas de Plantas/síntese química , Dobramento de Proteína , Sequência de Aminoácidos , Aminoácidos/análise , Aminoácidos/química , Cromatografia Líquida de Alta Pressão , Dissulfetos/química , Inibidores Enzimáticos/química , Fluorenos/química , Cinética , Dados de Sequência Molecular , Oxirredução , Proteínas de Plantas/química , Proteínas de Plantas/farmacologia , Compostos de Sulfidrila/química , Inibidores da Tripsina , alfa-Amilases/antagonistas & inibidores
16.
Int J Aging Hum Dev ; 44(1): 37-45, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9131380

RESUMO

While Locus of Control is typically operationalized as a single dispositional trait that generalizes across settings, it has also been conceptualized as two weakly related factors; Domain-Specific State Locus of Control and a generalized Trait Locus of Control. Malleability of these two factors was tested for recently widowed older adults in self-help support groups (n = 17) and a waiting-list control condition (n = 6). Domain-Specific State Locus of Control-Desire for Control subscale increased over the course of the three-week six-session intervention for support group participants. These group participants also showed decreased psychological distress from pre to post intervention. The change in Domain-Specific State Locus of Control-Desire for Control did not relate to this reduction in distress. As expected, Trait Locus of Control remained stable with greater Trait Internality related to less psychological symptomatology.


Assuntos
Luto , Controle Interno-Externo , Idoso , Análise de Variância , Feminino , Humanos , Acontecimentos que Mudam a Vida , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Escalas de Graduação Psiquiátrica , Apoio Social , Estatísticas não Paramétricas , Viuvez
17.
EMBO J ; 14(13): 3200-5, 1995 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-7621832

RESUMO

Circular dichroism and electrophoretic mobility shift studies were performed to confirm that dimerized N-terminal domains of bacterial repressors containing helix-turn-helix motifs are capable of high-affinity and specific DNA recognition as opposed to the monomeric N-terminal domains. Specific, high-affinity DNA binding proteins were designed and produced in which two copies of the N-terminal 1-62 domain of the bacteriophage 434 repressor are connected either in a dyad-symmetric fashion, with a synthetic linker attached to the C-termini, or as direct sequence repeats. Both molecules bound to their presumptive cognate nearly as tightly as does the natural (full-length and non-covalently dimerized) 434 repressor, showing that covalent dimerization can be used to greatly enhance the binding activity of individual protein segments. Circular dichroism spectroscopy showed a pronounced increase in the alpha-helix content when these new proteins interacted with their cognate DNA and a similar, although 30% lower, increase was also seen upon their interaction with non-cognate DNA. These results imply that a gradual conformational change may occur when helix-turn-helix motifs bind to DNA, and that a scanning mechanism is just as plausible for this motif class as that which is proposed for the more flexible basic-leucine zipper and basic-helix-loop-helix motifs.


Assuntos
Sequências Hélice-Alça-Hélice , Sequência de Aminoácidos , Sequência de Bases , Dicroísmo Circular , Simulação por Computador , DNA Bacteriano/metabolismo , Proteínas de Ligação a DNA/química , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Proteínas Repressoras/química
18.
Arch Biochem Biophys ; 315(2): 415-24, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7986086

RESUMO

A systematic study was undertaken in order to assess the substrate specificity of cyclin-B/cell division control protein kinase (CDC2) isolated from human HeLa cells, using 13-15 residue peptides with a central histone-like KKSPKK motif as a model. Replacement of the proline residue by any of the other 19 amino acids or D-proline drastically reduces or abolishes phosphorylation by CDC2. Changing the basic residues to Ala on either side of the -SP- structure differentially reduces phosphorylation. Molecular modeling and dynamics simulation indicated that the phosphorylation site of the peptide may have to adopt a turn-like conformation that will orientate the charged and hydrophobic residues so as to allow interaction with postulated binding surfaces within the CDC2 active site. It thus appears that, of the 20 coded amino acids, only proline can provide this conformation in short peptides. This is in agreement with the finding that sarcosine can replace proline in this respect (S. Ando et al. Biochem. Biophys. Res. Commun. 195, 837-843, 1993).


Assuntos
Proteína Quinase CDC2/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Células HeLa , Humanos , Cinética , Modelos Moleculares , Dados de Sequência Molecular , Peptídeos/química , Peptídeos/metabolismo , Fosforilação , Estrutura Secundária de Proteína , Relação Estrutura-Atividade , Especificidade por Substrato
19.
Leuk Lymphoma ; 14(5-6): 457-64, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7812205

RESUMO

Eighty nine of 104 patients with hairy cell leukemia (HCL), enrolled between 1985 and 1987 in a multicenter prospective study on human lymphoblastoid IFN alpha-n1, were evaluable for long-term follow-up. The induction treatment, 3 MU/mq daily for a median of 5.7 months, produced a response of 93%, complete+partial response (CR+PR) = 80%, minor (MR) = 13%. Neither prior splenectomy nor pre-treatment variables were associated with the rate of response to IFN. However maintenance treatment of 3 MU/mq weekly given randomly had a slightly significant effect on failure free survival (FFS). Of the 43 patients who relapsed, 31/36 (86%) obtained a new response with IFN. No differences in FFS were recorded between first and second response. At the third induction 7/11 patients were treated again with IFN, 4/7 obtaining some response, but the FFS was significantly worse. The overall survival is still 85%. We conclude that (1) IFN should be used as chronic uninterrupted treatment for HCL, (2) reduced dosage is sufficient to prolong the disease free status and (3) continuous lymphoblastoid IFN administration seems not to be associated with the development of resistance to retreatment.


Assuntos
Interferon-alfa/uso terapêutico , Leucemia de Células Pilosas/terapia , Idoso , Feminino , Humanos , Interferon-alfa/administração & dosagem , Interferon-alfa/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Recidiva
20.
Biochem Biophys Res Commun ; 196(3): 1019-24, 1993 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-8250861

RESUMO

It was recently shown that peptide NTM (RSANFTDNAKTIIVQLNESV), corresponding to residues 280-299 in the second conserved domain of HIV-1 envelope glycoprotein gp120, has spectral and sequence similarity with human vasoactive intestinal peptide, VIP (Veljkovic et al., Biochem. Biophys. Res. Commun., 189, 705-710, 1992). We found that natural autoantibodies cross-reactive with this peptide can be detected in sera from HIV-negative asthma patients and healthy blood donors. The level of these antibodies is significantly higher in asthma patients than in healthy individuals, suggesting that these antibodies can in fact be at least partly identical to natural anti-VIP antibodies previously described (Paul et al., Biochem. Biophys. Res. Commun., 130, 479-483, 1985; Paul et al., Science, 244, 158-1162, 1989). Possible origin and role of these antibodies in AIDS pathogenesis and therapy are discussed.


Assuntos
Autoanticorpos/metabolismo , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Fragmentos de Peptídeos/imunologia , Adulto , Sequência de Aminoácidos , Asma/sangue , Asma/imunologia , Sequência Conservada , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Proteína gp120 do Envelope de HIV/química , Humanos , Cinética , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Peptídeos/síntese química , Peptídeos/química , Peptídeos/imunologia , Peptídeo Intestinal Vasoativo/química
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