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1.
Recenti Prog Med ; 114(9): 497-501, 2023 09.
Artigo em Italiano | MEDLINE | ID: mdl-37529994

RESUMO

OBJECTIVE: This article aims to analyze the elements of the narrative which, applied to investigations of accidents at work, transform them into stories, making the dynamics of accidents clearer, more complete and emotionally engaging and also capable of being transferred to a non-experts audience. METHOD: The theoretical reference identified for the analysis of the accident histories is the work of the Lithuanian semiologist Algirdas Julien Greimas. The title, the dimensions of space and time, the characters (according to the actantial model), the point of view, the structure of the story (following the canonical narrative scheme), and the moral of the tale are the elements of the narration analyzed in this article. RESULTS: This article illustrates how the dynamics of accidents can lend themselves to being told according to the typical categories of narration and textual organization, resulting in them being enriched with important elements for the communication of prevention and the learning of safe behaviour. The accident investigation that becomes history takes on important characteristics also in terms of communication: the contents become clearer, more accessible and more engaging. Unlike traditional surveys, injury stories, through the elements of the narrative and in particular with the addition of indications for prevention, become an efficient learning and sharing tool valid in training contexts, and the contents effectively usable in practice of prevention workers. CONCLUSIONS: The narration applied to accidents at work, allowing for greater attention to the elements of the context, relationships and the emotional sphere of the various actors involved, is able to bring out more clearly the important and various factors that can contribute to causing an accident, becoming thus an effective tool for the transfer of indications for prevention.


Assuntos
Narração , Traumatismos Ocupacionais , Humanos , Traumatismos Ocupacionais/etiologia , Traumatismos Ocupacionais/prevenção & controle , Comunicação , Aprendizagem , Acidentes
3.
Int J Mol Sci ; 24(5)2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36902172

RESUMO

The coronavirus disease 19 (COVID-19) post pandemic evolution is correlated to the development of new variants. Viral genomic and immune response monitoring are fundamental to the surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Since 1 January to 31 July 2022, we monitored the SARS-CoV-2 variants trend in Ragusa area sequencing n.600 samples by next generation sequencing (NGS) technology: n.300 were healthcare workers (HCWs) of ASP Ragusa. The evaluation of anti-Nucleocapside (N), receptor-binding domain (RBD), the two subunit of S protein (S1 and S2) IgG levels in 300 exposed vs. 300 unexposed HCWs to SARS-CoV-2 was performed. Differences in immune response and clinical symptoms related to the different variants were investigated. The SARS-CoV-2 variants trend in Ragusa area and in Sicily region were comparable. BA.1 and BA.2 were the most representative variants, whereas the diffusion of BA.3 and BA.4 affected some places of the region. Although no correlation was found between variants and clinical manifestations, anti-N and anti-S2 levels were positively correlated with an increase in the symptoms number. SARS-CoV-2 infection induced a statistically significant enhancement in antibody titers compared to that produced by SARS-CoV-2 vaccine administration. In post-pandemic period, the evaluation of anti-N IgG could be used as an early marker to identify asymptomatic subjects.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Anticorpos Antivirais/sangue , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/virologia , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/imunologia , Sequenciamento de Nucleotídeos em Larga Escala , Imunoglobulina G/sangue , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Sicília/epidemiologia
4.
Eur J Investig Health Psychol Educ ; 11(4): 1254-1268, 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34698169

RESUMO

BACKGROUND: Workplace injuries in Italy still occur despite laws and safety norms. We need to understand the causes rooted in the context and social conditions, and need to improve the practice of Occupational Safety and Health (OSH) inspectors of the Workplace Safety and Prevention Services (WSPS) of the Italian regional health boards. The aims of this study were to describe the setting up of a Community of Practice (CoP) for the production of best practices for injury prevention and to evaluate the motivation of OSH inspectors for participating in the CoP and the effects of CoP participation on their professional practice. METHODS: Two workplace injury stories underwent peer review during each CoP meeting. We evaluated the CoP using a focus group and a questionnaire. RESULT: Between 2014 and 2021, the CoP met in 18 workshops. Over the 8-year period, the CoP grew from 20 to 150 participants. Overall, 30 stories underwent peer review and were published on the institutional website. The focus group participants stated that the reasons why they participated in the CoP were the need to share experience and to tackle new challenges. CONCLUSION: The CoP was found to be useful for improving professional practice by strengthening professional identity and contributing to the production of new knowledge.

5.
Pediatr Surg Int ; 34(7): 807-812, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29785651

RESUMO

PURPOSE: Testicular torsion (TT) mainly affects boys under 18 years old. To avoid orchiectomy, TT requires an immediate operative management. The etiology of TT is still controversial. Observed familiar recurrence suggests the presence of a genetic involvement. The INSL3 gene consists of two exons, and it is specifically expressed in fetal and adult Leydig cells. In transgenic mice, deletion of this gene was observed an increased testicular mobility and testicular torsion. We have hypothesized the possible involvement of the INSL3 gene as a predisposing factor of human TT. METHODS: We performed genetic analysis in 25 pediatric patients with unilateral and intravaginal TT (left, n = 13, 56%; right, n = 12, 48%). The age of the patients ranged from 1 to 16 years (median age n = 10.4 ± 5.46 years). In this study, we included two first male cousins affected by TT. Venous peripheral blood samples was obtained after parental written informed consent. RESULTS: The Thr60Ala polymorphism was detected in exon 1 of INSL3 gene and other 2 rarer variants (rs1047233 and rs1003887) were identified in the 3' untranslated region. These variants are prevalent in patients with TT instead of healthy subjects. CONCLUSIONS: Additional studies in a larger population are needed to better understand the clinical consequence of the INSL 3 variations founded. This would allow in the future to identify the patients at risk of TT to improve clinical management.


Assuntos
Insulina/genética , Proteínas/genética , Torção do Cordão Espermático/genética , Adolescente , Causalidade , Criança , Pré-Escolar , Humanos , Lactente , Insulina/sangue , Masculino , Polimorfismo Genético , Torção do Cordão Espermático/sangue
6.
Pediatr Dev Pathol ; 21(5): 456-460, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29426274

RESUMO

We describe a new Italian family with 7 members affected by hereditary hyperferritinemia cataract syndrome (HHCS), an uncommon autosomal dominant disease caused by mutations of the iron-responsive element (IRE) of the ferritin light chain (FTL) gene determining its overexpression. The family diagnosis of HHCS took place after finding high ferritin levels in a 6-year-old girl. Seven members of the family had bilateral and symmetrical cataracts, normal iron, and hematological parameters except for high serum ferritin levels. About 160 families/unrelated cases with HHCS are known worldwide. This report documents a second Italian family, with a c.-168G>C mutation that is located in the highly conserved 3-nucleotide bulge structure of the FTL in the 5' untranslated region. This case shows how important the family history is in reaching a correct diagnosis and avoiding unnecessary and invasive analysis. HHCS should be considered in the differential diagnosis of childhood hyperferritinemia, especially in the presence of normal transferrin saturation.


Assuntos
Apoferritinas/genética , Catarata/congênito , Distúrbios do Metabolismo do Ferro/congênito , Mutação , Catarata/genética , Criança , Feminino , Humanos , Distúrbios do Metabolismo do Ferro/genética , Itália , Masculino , Linhagem
7.
Hematology ; 23(6): 368-372, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29157184

RESUMO

OBJECTIVES: We performed molecular analysis to evaluate clinical implications of a rare nucleotide change, particularly when co-inherited with other known mutations in the globin clusters, in order to conduct an appropriate genetic counselling. METHODS: Complete blood cell counts and high-performance liquid chromatography were the routine first level analysis for patients referred to our Hospital Center in Palermo to undergo the screening test for haemoglobinopathies. Sequencing analysis was the selected method for the phenotypic characterization, especially in case of new or very rare mutations in globin genes. RESULTS: We report data of a rare single nucleotide variation at position -56 relative to transcription initiation site (NM_000518.4(HBB):c.-106G > C), identified in ten patients of Italian origin during the screening programme of the 'Sicilian population'. It was found in simple heterozygosity (n = 8), in association with beta haemoglobin variant Hb S (n = 1) and in heterozygosity with beta-thalassaemic allele IVS-I-1 G->A [(HBB):c.92 + 1G > A] and ααα anti3.7 rearrangement (n = 1). DISCUSSION: Heterozygous subjects for this substitution showed normal haematological and electrophoretic features. Heterozygotes for this mutation and other defect in globin genes showed the classical phenotype of a healthy carrier, therefore it can be considered a benign variant that does not alter the production and function of haemoglobin. CONCLUSION: This is another example of rare or new nucleotide variations whose identification and characterization is crucial in order to carry out appropriate genetic counselling to a potential risk couple.


Assuntos
Alelos , Genótipo , Padrões de Herança , Mutação , Polimorfismo de Nucleotídeo Único , Sítio de Iniciação de Transcrição , Globinas beta/genética , Hemoglobinopatias/sangue , Hemoglobinopatias/genética , Humanos , Itália , Família Multigênica , Linhagem , Fenótipo , Análise de Sequência de DNA
8.
Med Lav ; 108(3): 222-227, 2017 06 28.
Artigo em Italiano | MEDLINE | ID: mdl-28660873

RESUMO

BACKGROUND: Occupational Health and Safety (OSH) inspectors of the Health Units of Piedmont Region wrote 47 case histories based on data gathered from injury investigations as part of the project "From the injury investigation reports to case histories: creation of a collection of case histories on occupational injuries". Afterwards a Community of Practice (CoP) was initiated with the aim of sharing recommendations for prevention of occupational injuries. OBJECTIVE: The aims of the article are: 1) to describe the implementation process of the CoP; 2) to evaluate the benefits of CoP regarding the improvement of professional practice of OSH inspectors. METHODS: Two injury case histories were peer reviewed during each meeting of the CoP. A focus group was set up to evaluate benefits of CoP. Seven OSH inspectors participated in this focus group. RESULTS: Eight CoP meetings were organized and about 70 OSH inspectors participated. Fourteen stories were peer reviewed and eight were published on www.dors.it. Operators involved in the focus groups reported that the main reasons for participation in the CoP were the need to compare and tackle new challenges. The criticalities are tied to the turnover of the participants and to the lack of recognition by management. Most of the operators felt it was too early to include professionals such as Workers' Safety Representatives and Prevention and Safety Service Managers in the CoP due to their different professional roles. CONCLUSIONS: OSH inspectors reported professional benefits of CoP experience. We believe that this approach might be transferred, integrated and developed in other regions and included in the next national prevention plan.


Assuntos
Redes Comunitárias , Doenças Profissionais/prevenção & controle , Saúde Ocupacional , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Itália
9.
Hematology ; 22(9): 559-564, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28447549

RESUMO

OBJECTIVES: We report a case of a 7-year-old girl with severe hypochromic microcytic anemia, who was unresponsive to classical iron supplements. We suspected IRIDA, iron-refractory iron-deficiency anemia, a genetic iron metabolism disorder, caused by TMPRSS6 variations. TMPRSS6 encodes matriptase-2, a negative regulator of hepcidin, and its pathological variants are related to normal to high levels of hepcidin. We analyzed the TMPRSS6 gene and we improved clinical management of the patient, selecting the appropriate supplementation therapy. Intervention & Technique: The parenteral iron therapy was started, but the patient was only partially responsive and the anemia persisted. To confirm the diagnosis, the TMPRSS6 gene sequence was analyzed by DNA sequencing and other relevant biochemical parameters were evaluated. RESULTS: The TMPRSS6 sequence analysis showed a complex genotype with a rare heterozygous missense variant, in addition to other common polymorphisms. The serum hepcidin value was normal. We unexpectedly observed a normalization of patient's hemoglobin (Hb) levels only after liposomal iron treatment. DISCUSSION AND CONCLUSION: The proband was symptomatic for IRIDA during a critical phase of growth and development, but we did not find a clearly causative genotype. A long-term result, improving stably patient's Hb levels, was obtained only after liposomal iron supplementation. Children may be at greater risk for iron deficiency and the degree of anemia as well as the response to the iron supplements varies markedly patient to patient. Here, we show the importance of comprehensive study of these patients in order to collect useful information about genotype-phenotype association of genes involved in iron metabolism.


Assuntos
Anemia Ferropriva/diagnóstico , Anemia Ferropriva/genética , Predisposição Genética para Doença , Genótipo , Proteínas de Membrana/genética , Serina Endopeptidases/genética , Substituição de Aminoácidos , Anemia Hipocrômica/diagnóstico , Anemia Hipocrômica/genética , Anemia Hipocrômica/terapia , Anemia Ferropriva/terapia , Biomarcadores , Criança , Índices de Eritrócitos , Feminino , Estudos de Associação Genética , Humanos , Mutação , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Índice de Gravidade de Doença
10.
Mutagenesis ; 32(2): 275-281, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-27932515

RESUMO

In previously reported studies, we observed significantly high genotoxicity biomarkers in regularly transfused thalassaemic patients, thus, in this study, we better investigated the genotoxic effect of iron overload and of thalassaemia complications, including their drug treatments. The assessment was performed in 64 regularly transfused thalassaemic patients using cytokinesis-block micronucleus and comet assays. All patients were splenectomised and undergoing iron chelation therapy. To reduce hypoxia-induced oxidative damage, the patients with haemoglobin levels <9.5 g/dL were excluded. Serum concentrations of ferritin, iron, transferrin and the percentage of transferrin saturation, as well as cardiac and hepatic T2* magnetic resonance imaging, were considered to evaluate serum and organ siderosis.All genotoxic biomarkers significantly differed between patients and healthy subjects. Iron intake via blood transfusions was inversely related to percentage of DNA in tail. The disease complications affecting endpoints were active Hepatitis C virus infection, drug therapy for osteoporosis (i.e. bisphosphonates) and hormone replacement therapy for hypogonadism.The results, highlighting the combined effect of iron overload and, mainly, disease complications, including their respective pharmacological treatments, confirmed the increased cancer risk in thalassaemic patients.


Assuntos
Dano ao DNA , Sobrecarga de Ferro , Micronúcleos com Defeito Cromossômico , Reação Transfusional , Talassemia beta/genética , Adulto , Ensaio Cometa , Feminino , Humanos , Masculino , Testes para Micronúcleos , Pessoa de Meia-Idade , Talassemia beta/patologia , Talassemia beta/terapia
11.
Eur J Haematol ; 98(1): 67-74, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27440164

RESUMO

OBJECTIVE: The hemojuvelin-bone morphogenetic protein axis is the principal iron-dependent mechanism of hepcidin regulation. The determination of soluble hemojuvelin (sHJV) levels could allow for a better understanding of the pathophysiological mechanisms of hepcidin regulation in thalassaemia. METHOD: We have assessed sHJV in 45 transfused and 15 untransfused thalassaemic patients in comparison with 15 healthy subjects, evaluating its relationships with some parameters of iron overload, anaemia and erythropoiesis. RESULTS: Untransfused thalassaemic patients had more severe anaemia and erythropoietic activity, while in transfused patients, the transfused RBCs reduced % reticulocytes and sTfR, increased serum indices of iron overload and iron stores in the liver (low MRI T2* values). sHJV levels were higher in patients than in controls and in untransfused in comparison with transfused patients. In the transfused group, we also found that sHJV values are significantly related to serum ferritin, cardiac MRI T2* and growth differentiation factor 15 and are sensitive to hepatitis C virus infection. CONCLUSION: These results suggest that sHJV synthesis seems to be affected by an erythropoietic/hypoxic signal in untransfused patients that have severe anaemia, while in regularly transfused subjects, it is influenced by iron stores.


Assuntos
Transfusão de Sangue , Proteínas Ligadas por GPI/sangue , Talassemia/sangue , Talassemia/terapia , Adulto , Biomarcadores , Estudos de Casos e Controles , Índices de Eritrócitos , Feminino , Proteína da Hemocromatose , Hepcidinas/sangue , Humanos , Sobrecarga de Ferro/etiologia , Masculino , Pessoa de Meia-Idade , Talassemia/complicações , Adulto Jovem
12.
Hematology ; 22(3): 183-191, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27801288

RESUMO

OBJECTIVES: Redox imbalance and genotoxic damage are commonly observed in ß thalassaemic patients. The aim of this study was to assess the role of anaemia in oxidative and genotoxic damage in regularly transfused thalassaemic patients, undergoing iron chelation therapy. METHODS: We studied the relationships of haematological, biochemical and clinical parameters with oxidative (reactive oxygen species and 8-oxo-7,8-dihydro-2'-deoxyguanosine) and genotoxic biomarkers (Comet assay and cytokinesis-block micronucleus test) in blood samples from 105 patients. To reduce the early effect of redox-active iron, samples were collected when pharmacokinetics of the iron chelators ensured their maximum effectiveness. The transfusion regimen, cardiac and hepatic magnetic resonance imaging T2* were evaluated to characterize the patient cohort. Labile plasma iron (LPI) was also assayed. RESULTS: Haemoglobin level had a significant effect on ROS, %DNA in the tail and micronuclei-micronucleated cell frequency (p < 0.05). Higher Hb values reduced redox imbalance. LPI, detectable in 50.5% of patients, was related to the number of apoptotic and necrotic lymphocytes (p = 0.03), demonstrating the cytotoxic effect of iron. DISCUSSION: The results highlight that an adequate transfusion regimen is essential to limit oxidative and genotoxic damage in ß-thalassemic patients undergoing chelation therapy. CONCLUSION: Owing to the higher risk of cancer in the thalassaemic cohorts, specific genotoxicity/oxidative biomarkers should be monitored in order to ameliorate and formulate more personalized disease management.


Assuntos
Anemia/etiologia , Dano ao DNA , Estresse Oxidativo , Talassemia beta/genética , Talassemia beta/metabolismo , Adulto , Anemia/terapia , Biomarcadores , Transfusão de Sangue , Ensaio Cometa , Feminino , Humanos , Ferro/sangue , Ferro/metabolismo , Sobrecarga de Ferro/diagnóstico , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Fígado/metabolismo , Fígado/patologia , Linfócitos/metabolismo , Masculino , Testes para Micronúcleos , Pessoa de Meia-Idade , Espécies Reativas de Oxigênio/metabolismo , Talassemia beta/complicações , Talassemia beta/terapia
13.
Med Lav ; 107(3): 178-90, 2016 05 26.
Artigo em Italiano | MEDLINE | ID: mdl-27240222

RESUMO

BACKGROUND: Many authors consider narrative descriptions of injuries gathered by OSH inspectors extremely important in identifying causes, setting priorities and drawing up intervention strategies. Narratives provide additional insight regarding complex behaviour, attitudes and interactions, which help to understand the decision patterns and the context of the injury. Storytelling is an effective way of sharing and remembering information. OBJECTIVE: The main aim was to describe the experience of collecting stories from injury investigation reports, backed up by systematic prevention guidelines, that will improve information sharing by means of a knowledge transfer method based on storytelling. METHODS: OSH operators from Health Units, who were invited to provide the injury stories, were enrolled through educational workshops aimed at selecting the injuries to relate following the sentinel event approach, using an effective style of writing, identifying the key elements of the story and using witnesses' narratives to study in depth the critical points identified during the investigation. RESULTS: 110 OSH operators voluntarily joined the project between 2012 and first half of 2015. 33 injury stories were collected, discussed and published on Dors' website http://www.dors.it/storiedinfortunio. CONCLUSIONS: The results show that prevention and protection measures do indeed benefit from a narrative-based approach, so that health and safety can be viewed in a more comprehensive way by facilitating knowledge improvement and sharing.


Assuntos
Traumatismos Ocupacionais/prevenção & controle , Humanos , Narração
15.
Methods Mol Biol ; 1120: 55-74, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24470019

RESUMO

Redox agents have been historically considered pathological agents which can react with and damage many biological macromolecules including DNA, proteins, and lipids. However, a growing number of reports have suggested that mammalian cells can rapidly respond to ligand stimulation with a change in intracellular ROS thus indicating that the production of intracellular redox agents is tightly regulated and that they serve as intracellular signaling molecules being involved in a variety of cell signaling pathways. Numerous observations have suggested that some members of the Ras GTPase superfamily appear to regulate the production of redox agents and that oxidants can function as effector molecules for the small GTPases, thus contributing to their overall biological function. In addition, many of the Ras superfamily small GTPases have been shown to be redox sensitive, thanks to the presence of redox-sensitive sequences in their primary structure. The action of redox agents on these redox-sensitive GTPases is similar to that of guanine nucleotide exchange factors in that they perturb GTPase nucleotide-binding interactions that result in the enhancement of the guanine nucleotide exchange of small GTPases. Thus, Ras GTPases may act both as upstream regulators and downstream effectors of redox agents. Here we overview current understanding concerning the interplay between Ras GTPases and redox agents, also taking into account pathological implications of misregulation of this cross talk and highlighting the potentiality of these cellular pathways as new therapeutical targets for different pathologies.


Assuntos
Proteínas ras/metabolismo , Animais , Humanos , Terapia de Alvo Molecular , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
16.
Methods Mol Biol ; 1120: 97-120, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24470021

RESUMO

Since its original description, the yeast two-hybrid system has been extensively used to identify protein-protein interactions from many different organisms, thus providing a convenient mean to both screen for proteins that interact with a protein of interest and to characterize the known interaction between two proteins. In these years the technique has improved to overcome the limitations of the original assay, and many efforts have been made to scale up the technique and to adapt it to large-scale studies. In addition, variations have been introduced to enlarge the range of proteins and interactors that can be assayed by hybrid-based approaches. Several groups studying molecular mechanisms that underlie signal transduction pathways regulated by Ras GTPases have successfully used the yeast two-hybrid system or related methods to isolate and identify new binding partners of Ras proteins. Here we describe the basic protocol for a yeast two-hybrid library screening and for a small-scale yeast two-hybrid assay.


Assuntos
Técnicas do Sistema de Duplo-Híbrido , Proteínas ras/metabolismo , Proteínas de Ligação a DNA/metabolismo , Biblioteca Gênica , Genes Reporter/genética , Ligação Proteica , Proteínas Recombinantes de Fusão , Ativação Transcricional , Transformação Genética , beta-Galactosidase/metabolismo , Proteínas ras/química , Proteínas ras/genética
17.
Plant Mol Biol ; 83(4-5): 287-301, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23794143

RESUMO

One basic property of proteins is their ability to specifically target and form non-covalent complexes with other proteins. Such protein-protein interactions play key roles in all biological processes, extending from the formation of cellular macromolecular structures and enzymatic complexes to the regulation of signal transduction pathways. Identifying and characterizing protein interactions and entire interaction networks (interactomes) is therefore prerequisite to understand these processes on a molecular and biophysical level. Since its original description in 1989, the yeast two-hybrid system has been extensively used to identify protein-protein interactions from many different organisms, thus providing a convenient mean to both screen for proteins that interact with a protein of interest and to characterize the known interaction between two proteins. In these years the technique has improved to overcome the limitations of the original assay, and many efforts have been made to scale up the technique and to adapt it to large scale studies. In addition, variations have been introduced to enlarge the range of proteins and interactors that can be assayed by hybrid-based approaches. Several groups studying molecular mechanisms that underlie plant cell signal transduction pathways have successfully used the yeast two-hybrid system or related methods. In this review we provide a brief description of the technology, attempt to point out some of the pitfalls and benefits of the different systems that can be employed, and mention some of the areas, within the plant cell signalling field, where hybrid-based interaction assays have been particularly informative.


Assuntos
Proteínas de Plantas/metabolismo , Plantas/metabolismo , Transdução de Sinais , Técnicas do Sistema de Duplo-Híbrido , Células Vegetais/metabolismo
18.
PLoS One ; 7(9): e44705, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22970292

RESUMO

Loss-of-function mutations of the KRIT1 gene (CCM1) have been associated with the Cerebral Cavernous Malformation (CCM) disease, which is characterized by serious alterations of brain capillary architecture. The KRIT1 protein contains multiple interaction domains and motifs, suggesting that it might act as a scaffold for the assembly of functional protein complexes involved in signaling networks. In previous work, we defined structure-function relationships underlying KRIT1 intramolecular and intermolecular interactions and nucleocytoplasmic shuttling, and found that KRIT1 plays an important role in molecular mechanisms involved in the maintenance of the intracellular Reactive Oxygen Species (ROS) homeostasis to prevent oxidative cellular damage. Here we report the identification of the Kelch family protein Nd1-L as a novel molecular interactor of KRIT1. This interaction was discovered through yeast two-hybrid screening of a mouse embryo cDNA library, and confirmed by pull-down and co-immunoprecipitation assays of recombinant proteins, as well as by co-immunoprecipitation of endogenous proteins in human endothelial cells. Furthermore, using distinct KRIT1 isoforms and mutants, we defined the role of KRIT1 domains in the Nd1-L/KRIT1 interaction. Finally, functional assays showed that Nd1-L may contribute to the regulation of KRIT1 nucleocytoplasmic shuttling and cooperate with KRIT1 in modulating the expression levels of the antioxidant protein SOD2, opening a novel avenue for future mechanistic studies. The identification of Nd1-L as a novel KRIT1 interacting protein provides a novel piece of the molecular puzzle involving KRIT1 and suggests a potential functional cooperation in cellular responses to oxidative stress, thus expanding the framework of molecular complexes and mechanisms that may underlie the pathogenesis of CCM disease.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Sequência de Aminoácidos , Western Blotting , Proteínas de Transporte/química , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Homeostase , Humanos , Proteína KRIT1 , Microscopia de Fluorescência , Dados de Sequência Molecular , Ligação Proteica , Transporte Proteico , Espécies Reativas de Oxigênio/metabolismo , Técnicas do Sistema de Duplo-Híbrido
19.
Free Radic Biol Med ; 53(10): 1829-37, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22995637

RESUMO

Chronic anemia and tissue hypoxia increase intestinal iron absorption and mitochondrial impairment in thalassemic patients. Regular blood transfusions improve hemoglobin levels but determine an iron overload that induces reactive oxygen species (ROS) overproduction. The aim of this study was to assess cellular oxidative damage by detection of ROS, lipid peroxidation, 8-oxo-dG, and mitochondrial transmembrane potential (Δψ(m)) in transfused and untransfused thalassemic patients. We have also evaluated genotoxicity by CBMN and comet assay. Our data show that ROS and lipid hydroperoxides are significantly higher in thalassemic patients than in controls, especially in untransfused thalassemia intermedia patients. Moreover, the latter have a significant decrease in Δψ(m) that highlights the energetic failure in hypoxic state and the ROS overproduction in the respiratory chain. 8-OHdG levels are higher in thalassemics than in controls, but do not differ significantly between the two patient groups. Both genotoxicity biomarkers highlight the mutagenic potential of hydroxyl radicals released by iron in the Fenton reaction. Values for percentage of DNA in the comet tail and micronuclei frequency, significantly higher in transfused patients, could also be due to active hepatitis C virus infection and to the many drug treatments. Our biomonitoring study confirms the oxidative damage in patients with thalassemia major and shows an unexpected cellular oxidative damage in untransfused thalassemic patients. In addition to iron overload, the results highlight the important role played by hypoxia-driven mitochondrial ROS overproduction in determining oxidative damage in ß-thalassemias.


Assuntos
Transfusão de Sangue , Dano ao DNA , Desoxiguanosina/análogos & derivados , Peroxidação de Lipídeos , Potencial da Membrana Mitocondrial , Espécies Reativas de Oxigênio/sangue , Talassemia/sangue , Talassemia/terapia , 8-Hidroxi-2'-Desoxiguanosina , Adulto , Biomarcadores/sangue , Hipóxia Celular , Ensaio Cometa , Desoxiguanosina/sangue , Eritrócitos/química , Eritrócitos/citologia , Feminino , Humanos , Ferro/sangue , Sobrecarga de Ferro/etiologia , Masculino , Estresse Oxidativo , Talassemia/complicações , Talassemia/metabolismo
20.
J Signal Transduct ; 2012: 365769, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22175014

RESUMO

The members of the RasGTPase superfamily are involved in various signaling networks responsible for fundamental cellular processes. Their activity is determined by their guanine nucleotide-bound state. Recent evidence indicates that some of these proteins may be regulated by redox agents. Reactive oxygen species (ROSs) and reactive nitrogen species (RNSs) have been historically considered pathological agents which can react with and damage many biological macromolecules including DNA, proteins, and lipids. However, a growing number of reports have suggested that the intracellular production of ROS is tightly regulated and that these redox agents serve as signaling molecules being involved in a variety of cell signaling pathways. Numerous observations have suggested that some Ras GTPases appear to regulate ROS production and that oxidants function as effector molecules for the small GTPases, thus contributing to their overall biological function. Thus, redox agents may act both as upstream regulators and as downstream effectors of Ras GTPases. Here we discuss current understanding concerning mechanisms and physiopathological implications of the interplay between GTPases and redox agents.

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