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1.
Clin Genet ; 93(4): 762-775, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28892148

RESUMO

Smith-Kingsmore syndrome (SKS) OMIM #616638, also known as MINDS syndrome (ORPHA 457485), is a rare autosomal dominant disorder reported so far in 23 patients. SKS is characterized by intellectual disability, macrocephaly/hemi/megalencephaly, and seizures. It is also associated with a pattern of facial dysmorphology and other non-neurological features. Germline or mosaic mutations of the mTOR gene have been detected in all patients. The mTOR gene is a key regulator of cell growth, cell proliferation, protein synthesis and synaptic plasticity, and the mTOR pathway (PI3K-AKT-mTOR) is highly regulated and critical for cell survival and apoptosis. Mutations in different genes in this pathway result in known rare diseases implicated in hemi/megalencephaly with epilepsy, as the tuberous sclerosis complex caused by mutations in TSC1 and TSC2, or the PIK3CA-related overgrowth spectrum (PROS). We here present 4 new cases of SKS, review all clinical and molecular aspects of this disorder, as well as some characteristics of the patients with only brain mTOR somatic mutations.


Assuntos
Encéfalo/metabolismo , Megalencefalia/genética , Síndrome de Smith-Lemli-Opitz/genética , Serina-Treonina Quinases TOR/genética , Adolescente , Encéfalo/fisiopatologia , Proliferação de Células/genética , Criança , Classe I de Fosfatidilinositol 3-Quinases/genética , Deficiências do Desenvolvimento/genética , Deficiências do Desenvolvimento/fisiopatologia , Feminino , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/fisiopatologia , Masculino , Megalencefalia/diagnóstico por imagem , Megalencefalia/fisiopatologia , Mutação , Plasticidade Neuronal/genética , Proteínas Proto-Oncogênicas c-akt/genética , Síndrome de Smith-Lemli-Opitz/diagnóstico por imagem , Síndrome de Smith-Lemli-Opitz/fisiopatologia , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/genética
2.
Clin Genet ; 92(1): 91-98, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28067412

RESUMO

Processing of Precursor 1 (POP1) is a large protein common to the ribonuclease-mitochondrial RNA processing (RNase-MRP) and RNase-P (RMRP) endoribonucleoprotein complexes. Although its precise function is unknown, it appears to participate in the assembly or stability of both complexes. Numerous RMRP mutations have been reported in individuals with cartilage-hair hypoplasia (CHH) but, to date, only three POP1 mutations have been described in two families with features similar to anauxetic dysplasia (AD). We present two further individuals, one with severe short stature and a relatively mild skeletal dysplasia and another in whom AD was suspected. Biallelic POP1 mutations were identified in both. A missense mutation and a novel single base deletion were detected in proband 1, p.[Pro582Ser]:[Glu870fs*5]. Markedly reduced abundance of RMRP and elevated levels of pre5.8s rRNA was observed. In proband 2, a homozygous novel POP1 mutation was identified, p.[(Asp511Tyr)];[(Asp511Tyr)]. These two individuals show the phenotypic extremes in the clinical presentation of POP1-dysplasias. Although CHH and other skeletal dysplasias caused by mutations in RMRP or POP1 are commonly cited as ribosomal biogenesis disorders, recent studies question this assumption. We discuss the past and present knowledge about the function of the RMRP complex in skeletal development.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Nanismo/genética , Predisposição Genética para Doença , Anormalidades Musculoesqueléticas/genética , Osteocondrodisplasias/genética , Ribonucleoproteínas/genética , Criança , Pré-Escolar , Nanismo/diagnóstico por imagem , Nanismo/fisiopatologia , Feminino , Homozigoto , Humanos , Masculino , Anormalidades Musculoesqueléticas/diagnóstico por imagem , Anormalidades Musculoesqueléticas/fisiopatologia , Mutação de Sentido Incorreto/genética , Osteocondrodisplasias/diagnóstico por imagem , Osteocondrodisplasias/fisiopatologia , Fenótipo , RNA Longo não Codificante/genética
3.
Fish Physiol Biochem ; 39(3): 695-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23053614

RESUMO

Sea bass change their feeding rhythms from diurnal to nocturnal in winter, returning to diurnal feeding in spring. Despite behavioral data, the physiological changes that take place during such changes remain unexplored. In this paper, blood glucose rhythms of European sea bass with diurnal/nocturnal self-feeding rhythms were investigated during phase inversions of their feeding behavior (in winter and spring) when both diurnal and nocturnal fish coexist. Blood glucose showed daily variations in both seasons (ANOVA, p < 0.03), fitting a cosine function (COSINOR, p < 0.05) in all cases, except in diurnal fish in spring. The average blood glucose levels of nocturnal fish in winter (2.67 ± 0.09 mmol/l, mean ± SEM) were significantly (t test, p < 0.01) higher than in spring (2.20 ± 0.08 mmol/l), while they were similar (~2.25 mmol/l) in diurnal fish in both seasons. These findings revealed for the first time insights into the seasonal physiological changes that accompany changes in behavioral rhythms in diurnal and nocturnal sea bass.


Assuntos
Adaptação Biológica/fisiologia , Bass/sangue , Glicemia/fisiologia , Ritmo Circadiano/fisiologia , Comportamento Alimentar/fisiologia , Estações do Ano , Análise de Variância , Animais , Bass/fisiologia , Espanha
4.
Rev Clin Esp (Barc) ; 223(1): 1-9, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36182538

RESUMO

BACKGROUND AND OBJECTIVE: Available data support differences by gender in the leadership of clinical investigations (CI). This study analyzes to what extent women lead these investigations. MATERIALS AND METHODS: Observational-retrospective study in a tertiary university hospital associated with one of the most important health research institutes in Spain. We analyzed the principal investigators (PI) by gender from 2001 to 2020. MAIN OUTCOME: proportion of CI led by female doctors (FD) during the study period. SECONDARY OUTCOMES: differences in PI by gender according to the type of study: clinical trials (CT) or non-interventional-researches (NIR) and according to type of funding. DATA SOURCES: Research Ethics Committee (REC) and Human Resources Department registries. RESULTS: During the study, the REC approved 8466 protocols, 52% (4408/8466) were EC, the rest were NIR. Women led 39.7% (3360/8466) of the total. The gender gap was observed mainly in EC: FD were IP of 31.5% of them (1391/4408) and 48.5% (1969/4058) of NIR. This despite the increasing trend in the number of FD staff. By type of funding, when the studies were supported by private sector there was a wider gap markedly unfavorable for women. CONCLUSIONS: Our results show that there is underrepresentation of women in research leadership, mainly those with private financing. This study reinforces the idea that there is still a long way to go in this field. More studies are necessary to identify the existing differences that allow the implementation of actions at the institutional and cultural level that promote gender equality in the field of clinical research.


Assuntos
Liderança , Médicos , Humanos , Feminino , Espanha , Estudos Retrospectivos , Recursos Humanos
7.
Rev Esp Anestesiol Reanim ; 58(5): 290-4, 2011 May.
Artigo em Espanhol | MEDLINE | ID: mdl-21692253

RESUMO

BACKGROUND AND OBJECTIVE: Over 50% of patients still experience pain a year after mastectomy with or without lymphadenectomy. We aimed to determine the association between anesthetic technique, acute postoperative pain intensity, and the development of chronic postoperative pain. PATIENTS AND METHODS: Forty patients were randomly assigned to receive general anesthesia with or without a paravertebral nerve block for modified radical mastectomy. Postoperative pain was assessed on a visual analog scale at 60 minutes and 24 hours; the patients were also asked to respond to a telephone questionnaire on chronic pain 4 to 5 months later. RESULTS: No significant differences in acute pain were observed. Twenty-nine responded to the telephone questionnaire. Only 1 patient in the paravertebral block group reported chronic neuropathic pain and none had phantom breast pain. Only 1 patient (6.7%) in the paravertebral block group reported chronic neuropathic pain and none had phantom breast pain. In the group that received general anesthesia alone, 1 patient reported phantom breast pain and 6 patients had neuropathic pain, associated with phantom breast pain in 2 cases (incidence of chronic pain 50%; P = .01, Fischer exact test; relative risk, 7.5, 95% confidence interval, 1.0-53.5). The incidences of myofascial pain (neck muscle tightness) were similar in the 2 groups. CONCLUSIONS: Four to 5 months after mastectomy, fewer cases of chronic pain developed in the group operated under general anesthesia with a preincisional paravertebral block than in the group that received only general anesthesia, with postoperative morphine chloride for analgesia.


Assuntos
Anestesia Geral , Neoplasias da Mama/cirurgia , Mastectomia , Bloqueio Nervoso , Dor Pós-Operatória/epidemiologia , Doença Crônica , Feminino , Humanos , Bloqueio Nervoso/métodos
8.
Artigo em Inglês | MEDLINE | ID: mdl-20232776

RESUMO

BACKGROUND: Aspergillus fumigatus is the most prevalent airborne fungal pathogen, and the ribotoxin Asp f 1 is one of its major allergens. Alpha-Sarcin is a natural variant of Asp f 1 produced by the nonpathogenic fungus Aspergillus giganteus. Both proteins show a sequence identity of 87% and almost identical 3-dimensional structures. Alpha-Sarcin delta(7-22) is a deletion mutant that displays reduced immunoglobulin (Ig) E reactivity and is much less cytotoxic than wild-type proteins against human transformed cells. OBJECTIVE: A murine model of sensitization to Asp f 1 was established to test the response elicited by this alpha-sarcin delta(7-22) deletion mutant. METHODS: BALB/c mice were treated intraperitoneally with different mixtures of recombinant wild-type Asp f 1 and/or a suspension of a commercially available A. fumigatus standard extract. Mice were then intranasally challenged with Asp f 1 or alpha-sarcin delta(7-22). Sera were collected for subsequent measurement of Ig levels and histological analysis of the nostrils and lungs. RESULTS: Sensitization to Asp f 1 was successful only when the purified protein was first administered together with the A fumigatus suspension. The model was characterized by elevated levels of total IgE in serum and histological lesions in the lungs and nostrils. These symptoms were less severe when the deletion variant was the protein administered, thus confirming in vivo its lower toxic character. CONCLUSIONS: An easily reproducible mouse model of A fumigatus Asp f 1 sensitization was established. This model revealed alpha-sarcin delta(7-22) to be a potential candidate for immunotherapy.


Assuntos
Alérgenos/imunologia , Aspergillus fumigatus/imunologia , Proteínas Fúngicas/imunologia , Hipersensibilidade/terapia , Alérgenos/genética , Animais , Antígenos de Plantas , Feminino , Proteínas Fúngicas/genética , Deleção de Genes , Hipersensibilidade/imunologia , Hipersensibilidade/patologia , Imunoglobulina E/sangue , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Mucosa Nasal/patologia
9.
Rev Esp Anestesiol Reanim ; 57(4): 245-9, 2010 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-20499805

RESUMO

We report 2 cases of pulmonary torsion discovered during the early postoperative recovery of patients who had undergone lobectomy. Early diagnosis, based on chest radiography and confirmed by computed tomography, meant we were able to avoid major surgical resection and the development of further complications. Pulmonary torsion is a rare but potentially serious abnormality. Prompt diagnosis is the key to preventing tissue injury and complications such as necrotizing pneumonitis, thromboembolic disease, or septic shock. Among the diagnostic tests that can be carried out if there is good reason to suspect torsion, we emphasize simple chest radiography and fiberoptic bronchoscopy, supported by computed tomography or arteriography, even though a firm diagnosis requires surgical exploration of the affected lung. Definitive treatments range from reversing the torsion and securing the lung to resecting the lung if the parenchymal tissue has been fully compromised.


Assuntos
Pneumopatias/etiologia , Pneumonectomia/efeitos adversos , Anormalidade Torcional/etiologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
10.
Sci Rep ; 9(1): 11680, 2019 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-31406218

RESUMO

Immunotoxins are chimeric molecules, which combine antibody specificity to recognize and bind with high-affinity tumor-associated antigens (TAA) with the potency of the enzymatic activity of a toxin, in order to induce the death of target cells. Current immunotoxins present some limitations for cancer therapy, driving the need to develop new prototypes with optimized properties. Herein we describe the production, purification and characterization of two new immunotoxins based on the gene fusion of the anti-carcinoembryonic antigen (CEA) single-chain variable fragment (scFv) antibody MFE23 to α-sarcin, a potent fungal ribotoxin. One construct corresponds to a conventional monomeric single-chain immunotoxin design (IMTXCEAαS), while the other one takes advantage of the trimerbody technology and exhibits a novel trimeric format (IMTXTRICEAαS) with enhanced properties compared with their monomeric counterparts, including size, functional affinity and biodistribution, which endow them with an improved tumor targeting capacity. Our results show the highly specific cytotoxic activity of both immunotoxins in vitro, which was enhanced in the trimeric format compared to the monomeric version. Moreover, the trimeric immunotoxin also exhibited superior antitumor activity in vivo in mice bearing human colorectal cancer xenografts. Therefore, trimeric immunotoxins represent a further step in the development of next-generation therapeutic immunotoxins.


Assuntos
Antineoplásicos Imunológicos/farmacologia , Antígeno Carcinoembrionário/genética , Neoplasias Colorretais/terapia , Endorribonucleases/química , Proteínas Fúngicas/química , Imunotoxinas/farmacologia , Proteínas Recombinantes de Fusão/farmacologia , Animais , Antineoplásicos Imunológicos/química , Antineoplásicos Imunológicos/imunologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/imunologia , Antígeno Carcinoembrionário/imunologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/genética , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/mortalidade , Endorribonucleases/genética , Endorribonucleases/imunologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/imunologia , Expressão Gênica , Humanos , Imunotoxinas/química , Imunotoxinas/genética , Masculino , Camundongos , Camundongos Nus , Pichia/genética , Pichia/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/imunologia , Análise de Sobrevida , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Arch Soc Esp Oftalmol (Engl Ed) ; 93(3): 119-125, 2018 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-28571903

RESUMO

INTRODUCTION: Stargardt's disease is the most frequent form of inherited macular dystrophy in children and adults. It is a genetic eye disorder caused by mutations in ABCA4 gene with an autosomal recessive inheritance. ABCA4 is a very polymorphic and large gene containing 50 exons. The development of next generation sequencing (NGS) can be used for the genetic diagnosis of this disease. PATIENTS AND METHODS: A report is presented on two patients with a clinical diagnosis of Stargardt's disease whose genetic confirmation was performed by a NGS panel of 298 genes. RESULTS: Clinically, the patients showed bull's eye maculopathy and absence of flecks, and genetically they shared the Gly1961Glu mutation that could explain their common phenotype, together with c.C3056T:p.T1019M for case 1, and c.287del:p.Asn96Thrfs*19 for case 2. CONCLUSIONS: NGS is particularly useful in the diagnosis of Stargardt's disease as ABCA4 is a large gene with a high allelic heterogeneity that causes a wide range of clinical manifestations.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Degeneração Macular/congênito , Adulto , Feminino , Humanos , Degeneração Macular/diagnóstico , Degeneração Macular/genética , Masculino , Análise de Sequência de DNA , Doença de Stargardt , Adulto Jovem
12.
Br J Pharmacol ; 175(24): 4464-4479, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30248186

RESUMO

BACKGROUND AND PURPOSE: Chronic alcohol consumption alters the gut-brain axis, but little is known about alcohol binge episodes on the functioning of the intestinal barrier. We investigated the influence of ethanol binges on bacterial translocation, gut inflammation and immunity, and tight junction (TJ) structure and the ability of the biolipid oleoylethanolamide (OEA) to prevent ethanol binge-induced intestinal barrier dysfunction. EXPERIMENTAL APPROACH: OEA was injected i.p. before repeated ethanol administration by oral gavage. Plasma, spleen, liver and mesenteric lymph nodes (MLN) were collected in sterile conditions for determination of bacterial load. Immune/inflammatory parameters, TJ proteins and apoptotic markers were determined in colonic tissue by RT-PCR and Western blotting. TJ ultrastructure was examined by transmission electron microscopy. KEY RESULTS: Ethanol binges induced bacterial translocation to the MLN (mainly) and spleen. Colonic tissues showed signs of inflammation, and activation of innate (Toll-like receptor-4) and adaptive (IgA) immune systems and TJ proteins (occludin and claudin-3) were decreased after ethanol binges. Pretreatment with OEA reduced intestinal inflammation and immune activation and partially preserved the TJ structure affected by alcohol binges but had no effect on alcohol-induced apoptosis. Ultrastructural analyses of colonic TJs revealed dilated TJs in all ethanol groups, with less electron-dense material in non-pretreated rats. The protective effects of i.p. OEA did not reduce bacterial translocation to the MLN. However, intragastric OEA administration significantly reduced plasma LPS levels and bacterial translocation to the MLN. CONCLUSION AND IMPLICATIONS: OEA-based pharmacotherapies could potentially be useful to treat disorders characterized by intestinal barrier dysfunction, including alcohol abuse.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Endocanabinoides/farmacologia , Etanol/administração & dosagem , Etanol/efeitos adversos , Mucosa Intestinal/efeitos dos fármacos , Ácidos Oleicos/farmacologia , Alcoolismo/fisiopatologia , Animais , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/prevenção & controle , Mucosa Intestinal/metabolismo , Masculino , Ratos , Ratos Wistar
13.
Curr Protein Pept Sci ; 8(6): 558-72, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18220843

RESUMO

Actinoporins are a family of 20-kDa, basic proteins isolated from sea anemones, whose activity is inhibited by preincubation with sphingomyelin. They are produced in monomeric soluble form but, when binding to the plasma membrane, they oligomerize to produce functional pores which result in cell lysis. Equinatoxin II (EqtII) from Actinia equina and Sticholysin II (StnII) from Stichodactyla helianthus are the actinoporins that have been studied in more detail. Both proteins display a beta-sandwich fold composed of 10 beta-strands flanked on each side by two short alpha-helices. Two-dimensional crystallization on lipid monolayers has allowed the determination of low-resolution models of tetrameric structures distinct from the pore. However, the actual structure of the pore is not known yet. Wild-type EqtII and StnII, as well as a nice collection of natural and artificially made variants of both proteins, have been produced in Escherichia coli and purified. Their characterization has allowed the proposal of a model for the mechanism of pore formation. Four regions of the actinoporins structure seem to play an important role. First, a phosphocholine-binding site and a cluster of exposed aromatic residues, together with a basic region, would be involved in the initial interaction with the membrane, whereas the amphipathic N-terminal region would be essential for oligomerization and pore formation. Accordingly, the model states that pore formation would proceed in at least four steps: Monomer binding to the membrane interface, assembly of four monomers, and at least two distinct conformational changes driving to the final formation of the functional pore.


Assuntos
Membrana Celular/metabolismo , Proteínas Citotóxicas Formadoras de Poros/química , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Dobramento de Proteína , Anêmonas-do-Mar/citologia , Anêmonas-do-Mar/metabolismo , Sequência de Aminoácidos , Animais , Dados de Sequência Molecular , Proteínas Citotóxicas Formadoras de Poros/genética , Solubilidade
14.
Farm. comunitarios (Internet) ; 14(Supl 1): 1, junio 2022.
Artigo em Espanhol | IBECS (Espanha) | ID: ibc-209396

RESUMO

JUSTIFICACION: la asistencia sanitaria a domicilio es una de las estrategias que impulsan las administraciones sanitarias para pacientes pluripatológicos que viven en sus domicilios y que debido a su vulnerabilidad no pueden desplazarse a los centros sanitarios. El programa piloto “Hauskor” liderado por la Fundación Hurkoa, junto con la coordinación del Colegio Oficial de Farmacéuticos de Gipuzkoa (COFG), incluye farmacias comunitarias (FC) de Gipuzkoa que participan en la gestión de la medicación de pacientes en fragilidad social.OBJETIVO: implementar un servicio de atención farmacéutica domiciliaria (AFD) remunerado a pacientes frágiles incluidos en el programa “Hauskor” de la Fundación Hurkoa.MATERIAL Y METODOS: se diseñó un programa de AFD a pacientes frágiles entre la Fundación Hurkoa y el COFG, consistente en una revisión del botiquín, revisión del uso de la medicación a domicilio e intervenciones dirigidas en función de las incidencias detectadas, empleando sistemas personalizados de dosificación en aquellos pacientes que lo requirieran. En el programa participaron 5 FC de los municipios de Pasaia y Azkoitia de Gipuzkoa, que intervinieron sobre 6 pacientes. Tras los buenos resultados en salud y la buena satisfacción reportada por los pacientes, se elaboró un informe al programa “Hauskor” para lograr la remuneración del servicio a las farmacias participantes.RESULTADOS: a lo largo del año 2021, las farmacias participantes, prestaron el servicio a 6 pacientes. En cuanto a los resultados clínicos, destacar que en todas las revisiones de botiquín se encontraron medicamentos caducados o no utilizados y se retiraron entre 1-2 medicamentos a todos los pacientes. La remuneración de este nuevo servicio se obtuvo del programa “Hauskor”, de ayudas para apoyar las actividades de innovación, investigación y desarrollo social de la Diputación Foral de Gipuzkoa. (AU)


Assuntos
Humanos , Farmácias , Assistência Farmacêutica , Pacientes , Atenção à Saúde , Instalações de Saúde
15.
Rev Esp Enferm Dig ; 98(5): 322-9, 2006 May.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-16944992

RESUMO

INTRODUCTION: detection of early-stage colorectal carcinoma (CRC)--( Dukes A or B)--provides better survival rates in these patients. Thus, the effectiveness of screening programs in asymptomatic patients or of early diagnosis in symptomatic individuals has been postulated. The aim of this study was to establish whether a delay in diagnosis or other factors are related to CRC stage. PATIENTS AND METHODS: a retrospective study was performed on 96 patients with CRC. Age at diagnosis, gender distribution, intestinal disorders, diagnosis delay, primary sign and -regarding CRC- localization, stage (Dukes) and grade of differentiation (well differentiated; non-well differentiated; poorly differentiated) were recorded. RESULTS: diagnosis delay was 185 +/- 190 days. Patients delay in obtaining a diagnosis was 119 +/- 158 days. In 40% of patients CRC was diagnosed at an early stage (Dukes A or B), and in 13% CRC was poorly differentiated. The only factor with an independent effect on Dukes stage was tumor differentiation (p: 0.0012). Distal location was associated with less advanced tumors without statistical significance (p: 0.156). CONCLUSION: based on the presented data, a greater effort regarding screening programs for healthy people seems warranted, as improved survival has been demonstrated when diagnosis delay is reduced, particularly in patients with the highest mean delay.


Assuntos
Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/terapia , Fatores Etários , Idoso , Neoplasias Colorretais/epidemiologia , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Fatores Sexuais
16.
Biochim Biophys Acta ; 953(3): 280-8, 1988 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-3355841

RESUMO

The antitumor protein alpha-sarcin is a single polypeptide chain produced by the mold Aspergillus giganteus. It inhibits protein synthesis in some tumor cells by inactivating the larger ribosomal subunit. The secondary structure of the molecule has been studied by circular dichroism and predictive methods. The protein contains about 40% of periodic structures, mainly located at both extremes of the polypeptide chain. beta-Turns and aperiodic conformation appear at the central part of the molecule. Two different tyrosine populations have been observed in alpha-sarcin. Attempts to correlate solvent accessibility and particular protein regions have been carried out by using CD in the near-ultraviolet region, fluorescence and absorbance spectroscopies as well as acrylamide quenching and hydropathy profiles. Five different pH-induced conformational transitions are detected. Two of them, at pH 2.5 and 10.2, are denaturing transitions. These results are explained in terms of the structural features of this molecule, and related to its ribonucleolytic activity and ability to cross cell membranes.


Assuntos
Endorribonucleases , Proteínas Fúngicas , Acrilamida , Acrilamidas/farmacologia , Antineoplásicos , Aspergillus , Dicroísmo Circular , Temperatura Alta , Concentração de Íons de Hidrogênio , Conformação Proteica , Desnaturação Proteica , Inibidores da Síntese de Proteínas , Espectrometria de Fluorescência , Tirosina/análise
17.
Biochim Biophys Acta ; 1252(1): 43-52, 1995 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-7548165

RESUMO

alpha-Sarcin is a ribosome-inactivating protein that translocates across lipid bilayers, these two abilities explaining its cytotoxic character. This protein is composed of a single polypeptide chain with two disulfide bridges. Reduction and carboxyamidomethylation of alpha-sarcin results in protein unfolding, based on the results of the spectroscopic characterization of the chemically modified protein. The absorption and fluorescence emission bands of the tryptophan residues of the modified protein appear blue- and red-shifted, respectively. Far-UV circular dichroism analysis reveals the presence of residual secondary structure (beta-strands and turns) in the alkylated protein. This retains its ability to interact with lipid bilayers. It promotes vesicle aggregation, lipid-mixing between bilayers and leakage of the intravesicular aqueous contents. The modified protein tends to abolish the phase transition of acid phospholipids as detected by differential scanning calorimetry and depolarization measurements of fluorescence-labelled vesicles. The protein gain access to vesicle-entrapped trypsin. The fluorescence emission of the tryptophan residues is blue-shifted upon interaction of the protein with the bilayers, and anthracene incorporated into the hydrophobic core of the membranes quenches the tryptophan fluorescence emission of the protein. The secondary structure of the alkylated protein interacting with lipid vesicles has been studied by infrared spectroscopy. An increase in the alpha-helix and turn contents and a concomitant decrease in the beta-structure content are observed upon interaction with the bilayers. The results obtained are discussed in terms of the structural requirements for the interaction of alpha-sarcin with lipid membranes.


Assuntos
Antineoplásicos/química , Endorribonucleases , Proteínas Fúngicas/química , Bicamadas Lipídicas/química , Inibidores da Síntese de Proteínas/química , Varredura Diferencial de Calorimetria , Dicroísmo Circular , Polarização de Fluorescência , Fosfolipídeos/química , Dobramento de Proteína , Estrutura Secundária de Proteína , Espectrofotometria Infravermelho , Triptofano/química
18.
Biochim Biophys Acta ; 1340(1): 81-7, 1997 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-9217017

RESUMO

Two major proteins, alpha-sarcin and an antifungal polypeptide (AFP), are secreted by the mould Aspergillus giganteus MDH 18894 when it is cultured for 70-80 h. A third major protein is also found in the extracellular medium at 48-60 h, but it disappears as the culture proceeds. This protein has been isolated and characterized in terms of apparent molecular mass, electrophoretic and chromatographic behaviour, NH2-terminal primary structure, amino acid content, spectroscopical features, reactivity against anti-AFP antibodies, and antifungal activity. Based on the obtained results it would be an extracellular inactive precursor form of AFP, designated as the large form of AFP (lf-AFP). Its amino acid composition is identical to that of AFP but containing six extra residues. NH2-terminal sequence analysis of the first eight amino acid residues of this polypeptide revealed that the extra residues can be perfectly accommodated within the DNA-deduced sequence of the precursor form of AFP. Its alignment with precursor sequences of different proteins, secreted by a variety of Aspergillus spp., reveals the existence of a common tetrapeptide at the carboxy-terminal end of their leader peptides. This sequence would be Ile/Leu-Xaa-Yaa-Arg, being mostly Xaa and Yaa an acid residue (Asp/Glu) and alanine, respectively. The presence of lf-AFP as an extracellular protein would be in perfect agreement with the existence of this tetrapeptide motif, that can be involved in the protein secretion mechanisms of filamentous fungi.


Assuntos
Aspergillus/metabolismo , Proteínas Fúngicas/química , Sequência de Aminoácidos , Aminoácidos/análise , Aspergillus/crescimento & desenvolvimento , Dicroísmo Circular , Meios de Cultura , Dimerização , Eletroforese em Gel de Poliacrilamida , Endorribonucleases/isolamento & purificação , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/farmacologia , Fusarium/efeitos dos fármacos , Peso Molecular , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Trichoderma/efeitos dos fármacos
19.
Biochim Biophys Acta ; 847(3): 273-9, 1985 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-2998482

RESUMO

The present results show that the catalytic subunit of cyclic AMP-dependent protein kinase phosphorylates the 50 kDa protein of rat liver phospholipid methyltransferase at one single site on a serine residue. Phosphorylation of this site is stimulated 2- to 3-fold by S-adenosylmethionine. S-adenosylmethionine-dependent protein phosphorylation is time- and dose-dependent and occurs at physiological concentrations. S-adenosylhomocysteine has no effect on protein phosphorylation but inhibits S-adenosylmethionine-dependent protein phosphorylation. S-Adenosylmethionine/S-adenosylhomocysteine ratios varying from 0 to 5 produce a dose-dependent stimulation of the phosphorylation of the 50 kDa protein. In conclusion, these results show, for the first time, that the ratio S-adenosylmethionine/S-adenosylhomocysteine can modulate phosphorylation of a specific protein.


Assuntos
Homocisteína/análogos & derivados , Fígado/enzimologia , Metiltransferases/metabolismo , Proteínas Quinases/metabolismo , S-Adenosil-Homocisteína/metabolismo , S-Adenosilmetionina/metabolismo , Animais , AMP Cíclico/metabolismo , Fluoretos/farmacologia , Cinética , Peso Molecular , Fosfatidil-N-Metiletanolamina N-Metiltransferase , Fosfatidiletanolamina N-Metiltransferase , Fosforilação , Ratos
20.
Biochim Biophys Acta ; 1068(1): 9-16, 1991 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-1892859

RESUMO

The antitumour protein alpha-sarcin modifies the thermotropic behaviour of phospholipid vesicles. This has been studied by fluorescence depolarization measurements and differential scanning calorimetry. A surface protein-phospholipid interaction is detected by measuring the polarization degree of TMA-DPH-labelled vesicles. At the higher protein/lipid molar ratios studied, the alpha-sarcin-vesicles complexes exhibit different thermotropic behaviour depending on whether they are prepared above or below the Tm of the corresponding phospholipid. Labelling of the protein with photoactive phospholipids has also been considered. alpha-Sarcin penetrates the bilayer deep enough to be labelled with the photoactive group located at the C-12 of the fatty acid acyl chain of phospholipids forming vesicles.


Assuntos
Antineoplásicos/farmacologia , Endorribonucleases , Proteínas Fúngicas/farmacologia , Bicamadas Lipídicas/química , Proteínas de Membrana/química , Fosfolipídeos/química , Varredura Diferencial de Calorimetria , Polarização de Fluorescência , Temperatura
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