Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Front Med (Lausanne) ; 9: 922345, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35899217

RESUMO

Introduction: Frailty is a geriatric syndrome, a clinical state of vulnerability for developing dependency and/or death. Due to its multidimensional nature, Comprehensive Geriatric Assessment (CGA) constitutes the best strategy to evaluate frailty in older patients. Accumulation of deficits model synthesizes the global assessment of geriatric domains in the Frailty Index (FI) score. Muscle Ultrasound (MUS) has been employed to evaluate muscle mass wasting as tool to assess sarcopenia in late life. The present study aims to evaluate the association between CGA-based FI and MUS measures in a population of hospitalized older adults. Methods: Patients aged ≥65 years underwent CGA for the evaluation of the domains of health and functional status, psycho-cognition, nutritional status, socio-environmental condition. Following standard procedure, a CGA-based FI was elaborated, taking into account 38 multidimensional items. Muscle thicknesses (MT) of rectus femoris plus vastus intermedius were measured through MUS axial cross-section. Multivariable regression analysis was employed to determine factors associated with FI. Results: The study population consisted of 136 older patients, 87 men (63.9%), with median age of 74 (70-81) years, FI of 0.3 (0.21-0.46), and MT of rectus femoris plus vastus intermedius 29.27 (23.08-35.7) mm. At multivariable regression analysis, FI resulted significantly and independently associated with age and MT. Conclusion: Muscle thicknesses of rectus femoris plus vastus intermedius, measured through MUS, resulted to be significantly related to FI in a population of hospitalized older patients. In the CGA-based assessment of frailty, MUS may constitute an additional imaging domain.

2.
Metabolites ; 11(4)2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33807300

RESUMO

Plants emit volatile organic compounds (VOCs) that induce metabolomic, transcriptomic, and behavioral reactions in receiver organisms, including insect pollinators and herbivores. VOCs' composition and concentration may influence plant-insect or plant-plant interactions and affect soil microbes that may interfere in plant-plant communication. Many Trichoderma fungi act as biocontrol agents of phytopathogens and plant growth promoters. Moreover, they can stimulate plant defense mechanisms against insect pests. This study evaluated VOCs' emission by olive trees (Olea europaea L.) when selected Trichoderma fungi or metabolites were used as soil treatments. Trichoderma harzianum strains M10, T22, and TH1, T. asperellum strain KV906, T. virens strain GV41, and their secondary metabolites harzianic acid (HA), and 6-pentyl-α-pyrone (6PP) were applied to olive trees. Charcoal cartridges were employed to adsorb olive VOCs, and gas chromatography mass spectrometry (GC-MS) analysis allowed their identification and quantification. A total of 45 volatile compounds were detected, and among these, twenty-five represented environmental pollutants and nineteen compounds were related to olive plant emission. Trichoderma strains and metabolites differentially enhanced VOCs production, affecting three biosynthetic pathways: methylerythritol 1-phosphate (MEP), lipid-signaling, and shikimate pathways. Multivariate analysis models showed a characteristic fingerprint of each plant-fungus/metabolite relationship, reflecting a different emission of VOCs by the treated plants. Specifically, strain M10 and the metabolites 6PP and HA enhanced the monoterpene syntheses by controlling the MEP pathway. Strains GV41, KV906, and the metabolite HA stimulated the hydrocarbon aldehyde formation (nonanal) by regulating the lipid-signaling pathway. Finally, Trichoderma strains GV41, M10, T22, TH1, and the metabolites HA and 6PP improve aromatic syntheses at different steps of the shikimate pathway.

3.
Cells ; 10(2)2021 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-33669936

RESUMO

Heart failure (HF) represents the end-stage condition of several structural and functional cardiovascular diseases, characterized by reduced myocardial pump function and increased pressure load. The dysregulation of neurohormonal systems, especially the hyperactivity of the cardiac adrenergic nervous system (ANS), constitutes a hallmark of HF and exerts a pivotal role in its progression. Indeed, it negatively affects patients' prognosis, being associated with high morbidity and mortality rates, with a tremendous burden on global healthcare systems. To date, all the techniques proposed to assess the cardiac sympathetic nervous system are burdened by intrinsic limits that hinder their implementation in clinical practice. Several biomarkers related to ANS activity, which may potentially support the clinical management of such a complex syndrome, are slow to be implemented in the routine practice for several limitations due to their assessment and clinical impact. Lymphocyte G-protein-coupled Receptor Kinase 2 (GRK2) levels reflect myocardial ß-adrenergic receptor function in HF and have been shown to add independent prognostic information related to ANS overdrive. In the present manuscript, we provide an overview of the techniques currently available to evaluate cardiac ANS in HF and future perspectives in this field of relevant scientific and clinical interest.


Assuntos
Quinase 2 de Receptor Acoplado a Proteína G/metabolismo , Insuficiência Cardíaca/enzimologia , Sistema Nervoso Simpático/enzimologia , Animais , Biomarcadores/metabolismo , Insuficiência Cardíaca/fisiopatologia , Humanos , Linfócitos/enzimologia , Modelos Biológicos
4.
Eur J Prev Cardiol ; 28(1): 87-97, 2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33624104

RESUMO

Along with epidemiologic transitions of the global population, the burden of aortic stenosis (AS) is rapidly increasing and transcatheter aortic valve replacement (TAVR) has quickly spread; indeed, it is nowadays also employed in treating patients with AS at intermediate operative risk. Nonetheless, the less invasive interventional strategy still carries relevant issues concerning post-procedural optimal antithrombotic strategy, given the current indications provided by guidelines are not completely supported by evidence-based data. Geriatric patients suffer from high bleeding and thromboembolic risks, whose balance is particularly subtle due to the presence of concomitant conditions, such as atrial fibrillation and chronic kidney disease, that make the post-TAVR antithrombotic management particularly insidious. This scenario is further complicated by the lack of specific evidence regarding the 'real-life' complex conditions typical of the geriatric syndromes, thus, the management of such a heterogeneous population, ranging from healthy ageing to frailty, is far from being defined. The aim of the present review is to summarize the critical points and the most updated evidence regarding the post-TAVR antithrombotic approach in the geriatric population, with a specific focus on the most frequent clinical settings.


Assuntos
Estenose da Valva Aórtica/tratamento farmacológico , Estenose da Valva Aórtica/cirurgia , COVID-19/complicações , Fibrinolíticos/uso terapêutico , Substituição da Valva Aórtica Transcateter , Fatores Etários , Idoso , Estenose da Valva Aórtica/complicações , Humanos , Fatores de Risco
5.
Eur J Intern Med ; 86: 86-90, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33485737

RESUMO

INTRODUCTION: Heart failure (HF) is frequently associated with comorbidities. 123I-metaiodobenzylguanidine (123I-mIBG) imaging constitutes an effective tool to measure cardiac adrenergic innervation and to improve prognostic stratification in HF patients, including the risk of major arrhythmic events. Although comorbidities have been individually associated with reduced cardiac adrenergic innervation, thus suggesting increased arrhythmic risk, very comorbid HF patients seem to be less likely to experience fatal arrhythmias. We evaluated the impact of the number of comorbidities on cardiac adrenergic innervation, assessed through 123I-mIBG imaging, in patients with systolic HF. METHODS: Patients with systolic HF underwent clinical examination, transthoracic echocardiography and cardiac 123I-mIBG scintigraphy. The presence of 7 comorbidities/conditions (smoking, chronic obstructive pulmonary disease, diabetes mellitus, peripheral artery disease, atrial fibrillation, chronic ischemic heart disease and chronic kidney disease) was documented in the overall study population. RESULTS: The study population consisted of 269 HF patients with a mean age of 66±11 years, a left ventricular ejection fraction (LVEF) of 31±7%, and 153 (57%) patients presented ≥3 comorbidities. Highly comorbid patients presented a reduced late heart to mediastinum (H/M) ratio, while no significant differences emerged in terms of early H/M ratio and washout rate. Multiple regression analysis revealed that the number of comorbidities was not associated with mIBG parameters of cardiac denervation, which were correlated with age, body mass index and LVEF. CONCLUSION: In systolic HF patients, the number of comorbidities is not associated with alterations in cardiac adrenergic innervation. These results are consistent with the observation that very comorbid HF patients suffer lower risk of sudden cardiac death.


Assuntos
Insuficiência Cardíaca , Função Ventricular Esquerda , 3-Iodobenzilguanidina , Idoso , Coração/diagnóstico por imagem , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/epidemiologia , Humanos , Pessoa de Meia-Idade , Compostos Radiofarmacêuticos , Volume Sistólico , Sistema Nervoso Simpático
6.
Antioxidants (Basel) ; 9(7)2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-32635186

RESUMO

Food plays a central role in health, especially through consumption of plant-derived foods. Functional foods, supplements, and nutraceuticals are increasingly entering the market to respond to consumer demand for healthy products. They are foods, supplements, and ingredients which offer health benefits beyond the standard nutritional value. Some benefits are associated with phenolic compounds and phytochemicals with antioxidant properties. An olive pâté (OP) was added with antioxidants derived from olive mill wastewater (OMWW) to obtain a functional product rich in phenolic compounds. The olive pâté is produced from the ground olive pericarp, which shows an excellent natural antioxidant content. The OMWW is a waste product from oil processing, which is also rich in phenolic compounds. The result was a product rich in trans-resveratrol, OH tyrosol, and tyrosol in concentrations such as satisfying the European community's claims regarding the possible antioxidant action on plasma lipids with excellent shelf-life stability. The total phenolic content was assayed by a colorimetric method, the antioxidant activity by the ABTS [(2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)] test, the phenolic profile by Q Exactive Orbitrap LC-MS/MS. The shelf-life stability was confirmed by yeast, molds, and total microbial count, pH, and water activity determinations, and the best pasteurization parameters were determined. The palatability was judged as excellent.

7.
Medicina (Kaunas) ; 55(10)2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31600985

RESUMO

Background and objectives: Olive pâté (OP) is an olive-derived product with potentially beneficial effects on human health due to the presence of natural antioxidants. The present dietary supplementation study aimed to evaluate the effects on blood antioxidant levels of an olive pâté reinforced with natural antioxidants (ROP) recovered from olive mill waste. Materials and methods: Ninety-eight healthy volunteers (M = 54, 55%, age 18-25) were divided into two groups: A (n = 49), practicing three or more days of physical activity a week, and B (n = 49), practicing less than two. Each group was split into two subgroups, receiving dietary supplementation with OP or ROP. The status of smoker was also recorded, and a biological antioxidant potential (BAP) test was performed on each subject. Results: The BAP values increased with both OP (n = 30) and ROP (n = 68) but ROP supplementation showed higher increments (736.9 µmol/L) than OP (339.6). The increment was significantly higher for smokers (n = 15), 1122.9 vs. non-smokers (n = 53), 635.7, with values in percent of baseline, respectively, 34.6% and 16.2% (P < 0.01). Conclusions: The ROP nutritional supplementation appears useful to increase antioxidant activity, with better effect in smokers; further studies should confirm the finding and investigate its biological bases.


Assuntos
Antioxidantes/uso terapêutico , Fumar Cigarros/metabolismo , Olea/metabolismo , Adolescente , Adulto , Antioxidantes/metabolismo , Fumar Cigarros/efeitos adversos , Fumar Cigarros/fisiopatologia , Feminino , Humanos , Masculino
8.
Pancreatology ; 19(3): 409-413, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30890309

RESUMO

BACKGROUND: Benign Pancreatic Hyperenzymemia (BPH) is characterized by a long-term increase of serum pancreatic enzymes (PE) in otherwise healthy subjects. The study investigates the prevalence and correlates of the condition using data from Electronic Health Records (EHR) in a large sample of general population, to identify subjects potentially affected by BPH. METHODS: Cross-sectional retrospective observational study integrated by a follow-up visit. RESULTS: The database of a reference laboratory identified, out of 577.251 admittances from 2011 to 2015, 4964 patients tested at least for one PE assay and 1688 subjects who had at least 3 PE tests (normal or increased) over two years. Forty-two individuals showed an increase of PE at least three times throughout 2 years without any evidence of pancreatic disease, even after matching with the ICD 9-CM code in the GPs database. Data retrieved at follow-up visit showed that for 34 the diagnosis of BPH could be made. CONCLUSIONS: Our data indicate that BPH prevalence among subjects underwent blood testing for multiple PE testing is 2%. This condition, even if not a disease, is perceived by nearly all the BPH patients as a serious threat to their life. Further studies are needed to manage its heavy psychological impact.


Assuntos
Pâncreas/enzimologia , Pancreatopatias/epidemiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos Transversais , Registros Eletrônicos de Saúde , Feminino , Humanos , Lactente , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Pâncreas/metabolismo , Prevalência , Estudos Retrospectivos , Adulto Jovem
9.
G Ital Nefrol ; 30(2)2013.
Artigo em Italiano | MEDLINE | ID: mdl-23832454

RESUMO

Hydrogen sulfide, (H2S), is an endogenous gas which exerts a protective function in several biological processes, including those involved in inflammation, blood pressure regulation, and energy metabolism. The enzymes involved in H2S production are cysthationine -synthetase, cysthationine -lyase and 3-mercaptopyruvate sulfurtransferase. Low plasma H2S levels have been found in chronic renal failure (CRF) in both humans and animal models. The mechanisms leading to H2S deficiency in CRF are linked to reduced gene expression of cysthationine -lyase. Intense research is currently under way to discover the link between low H2S levels, CRF progression and the uremic syndrome and to determine whether therapeutic interventions aimed at increasing H2S levels might benefit these patients.


Assuntos
Sulfeto de Hidrogênio/metabolismo , Falência Renal Crônica/fisiopatologia , Liases/fisiologia , Vasodilatação/fisiologia , Animais , Apoptose , Proteínas Reguladoras de Apoptose/biossíntese , Proteínas Reguladoras de Apoptose/genética , Pressão Sanguínea/fisiologia , Doenças Cardiovasculares/fisiopatologia , Células Cultivadas , Cisteína/metabolismo , Progressão da Doença , Indução Enzimática , Homocisteína/metabolismo , Humanos , Inflamação , Rim/metabolismo , Rim/fisiopatologia , Peroxidação de Lipídeos , Liases/biossíntese , Liases/genética , Camundongos , Camundongos Knockout , Estresse Oxidativo , Ratos
10.
Nephrol Dial Transplant ; 28(5): 1214-24, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23439585

RESUMO

BACKGROUND: Folate therapy reduces, but does not normalize homocysteine (Hcy) levels, frequently elevated in chronic kidney disease (CKD). The mechanisms of this folate resistance are unknown. Cellular acquisition of folate is mediated by folate receptors (FRs), whose expression is also modulated by folate status, through an Hcy-dependent regulation mechanism involving heterogeneous nuclear ribonucleoprotein-E1 (hnRNP-E1). Our objective was to evaluate whether an alteration of the FR2 (the form present in nucleated blood cells) expression is present in CKD patients on haemodialysis (HD), and its susceptibility to folate treatment. METHODS: A population of chronic uraemic patients on HD was enrolled, along with a control group, and studies on FR2 receptor expression and related items were performed in plasma and mononuclear cells from peripheral blood. A subgroup of patients was treated with methyltetrahydrofolate for 1 month. RESULTS: In HD, there was a significant reduction in FR2 protein expression compared with controls, not correlated with Hcy concentrations, while its mRNA levels were significantly increased. After folate treatment, there was a significant mRNA decrease, in the absence of significant changes in receptor protein expression. hnRNP-E1 gene and protein expression levels increased pre-treatment, while decreased post-treatment. CONCLUSIONS: In HD, FR2 expression is altered in peripheral mononuclear cells, since its levels are decreased and are not responsive to variations in Hcy concentration, while the intracellular machinery (receptor mRNA and hnRNP-E1), possibly triggering its regulation, is conserved. These findings provide insight into the mechanisms of folate resistance in uraemia.


Assuntos
Biomarcadores/metabolismo , Resistência a Medicamentos , Receptor 2 de Folato/metabolismo , Ácido Fólico/administração & dosagem , Diálise Renal , Uremia/metabolismo , Western Blotting , Estudos de Casos e Controles , Doença Crônica , Proteínas de Ligação a DNA , Feminino , Citometria de Fluxo , Receptor 2 de Folato/genética , Seguimentos , Ribonucleoproteínas Nucleares Heterogêneas/genética , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Prognóstico , RNA Mensageiro/genética , Proteínas de Ligação a RNA , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Uremia/tratamento farmacológico
11.
J Cell Biochem ; 114(7): 1536-48, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23297114

RESUMO

H2S is the third endogenous gaseous mediator, after nitric oxide and carbon monoxide, possessing pleiotropic effects, including cytoprotection and anti-inflammatory action. We analyzed, in an in vitro model entailing monocyte adhesion to an endothelial monolayer, the changes induced by H2S on various potential targets, including cytokines, chemokines, and proteases, playing a crucial role in inflammation and cell adhesion. Results show that H2S prevents the increase in monocyte adhesion induced by tumor necrosis factor-α (TNF-α). Under these conditions, downregulation of monocyte chemoattractant protein-1 (MCP-1), chemokine C-C motif receptor 2, and increase of cluster of differentiation 36 could be detected in monocytes. In endothelial cells, H2 S treatment reduces the increase in MCP-1, inter-cellular adhesion molecule-1, vascular cell adhesion molecule-1, and of a disintegrin and metalloproteinase metallopeptidase domain 17 (ADAM17), both at the gene expression and protein levels. Cystathionine γ-lyase and 3-mercaptopyruvate sulfurtransferase, the major H2S forming enzymes, are downregulated in endothelial cells. In addition, H2S significantly reduces activation of ADAM17 by PMA in endothelial cells, with consequent reduction of both ADAM17-dependent TNF-α ectodomain shedding and MCP-1 release. In conclusion, H2S is able to prevent endothelial activation by hampering endothelial activation, triggered by TNF-α. The mechanism of this protective effect is mainly mediated by down-modulation of ADAM17-dependent TNF-converting enzyme (TACE) activity with consequent inhibition of soluble TNF-α shedding and its relevant MCP-1 release in the medium. These results are discussed in the light of the potential protective role of H2S in pro-inflammatory and pro-atherogenic processes, such as chronic renal failure.


Assuntos
Proteínas ADAM/metabolismo , Adesão Celular/efeitos dos fármacos , Sulfeto de Hidrogênio/farmacologia , Inflamação/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Proteínas ADAM/genética , Proteína ADAM17 , Western Blotting , Linhagem Celular , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Humanos , Reação em Cadeia da Polimerase
12.
J Ren Nutr ; 22(5): 507-514.e1, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22226754

RESUMO

OBJECTIVE: Uremia represents a state where hyperhomocysteinemia is resistant to folate therapy, thus undermining intervention trials' efficacy. N-acetylcysteine (NAC), an antioxidant, in addition to folates (5-methyltetrahydrofolate, MTHF), was tested in a population of hemodialysis patients. DESIGN: The study is an open, parallel, intervention study. SETTING: Ambulatory chronic hemodialysis patients. SUBJECTS: Clinically stable chronic hemodialysis patients, on hemodialysis since more than 3 months, undergoing a folate washout. Control group on standard therapy (n = 50). INTERVENTION: One group was treated with intravenous MTHF (MTHF group, n = 48). A second group was represented by patients treated with MTHF, and, during the course of 10 hemodialysis sessions, NAC was administered intravenous (MTHF + NAC group, n = 47). MAIN OUTCOME MEASURE: Plasma homocysteine measured before and after dialysis at the first and the last treatment. RESULTS: At the end of the study, there was a significant decrease in predialysis plasma homocysteine levels in the MTHF group and MTHF + NAC group, compared with the control group, but no significant difference between the MTHF group and MTHF + NAC group. A significant decrease in postdialysis plasma homocysteine levels in MTHF + NAC group (10.27 ± 0.94 µmol/L, 95% confidence interval: 8.37-12.17) compared with the MTHF group (16.23 ± 0.83, 95% confidence interval: 14.55-17.90) was present. In the MTHF + NAC group, 64% of patients reached a postdialysis homocysteine level <12 µmol/L, compared with 19% in the MTHF group and 16% in the control group. CONCLUSIONS: NAC therapy induces a significant additional decrease in homocysteine removal during dialysis. The advantage is limited to the time of administration.


Assuntos
Acetilcisteína/administração & dosagem , Ácido Fólico/análogos & derivados , Hiper-Homocisteinemia/tratamento farmacológico , Diálise Renal , Idoso , Quimioterapia Combinada , Feminino , Ácido Fólico/administração & dosagem , Homocisteína/sangue , Humanos , Hiper-Homocisteinemia/etiologia , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade
13.
J Ren Nutr ; 22(1): 191-4, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22200441

RESUMO

Chronic renal failure and uremia represent states wherein high blood levels of homocysteine, a cardiovascular risk factor, are largely resistant to folate therapy. Indeed, normalization of homocysteine levels through vitamin administration is rarely achieved in this population, and this fact could explain, among other causes, the negative results of intervention trials designed to lower cardiovascular risk. Dialysis itself lowers homocysteine levels, albeit transitorily. N-acetylcysteine therapy could induce an additional decrease in homocysteine removal during dialysis, thus representing an alternative approach in the attempt to lower cardiovascular risk in these patients.


Assuntos
Hiper-Homocisteinemia/complicações , Hiper-Homocisteinemia/tratamento farmacológico , Falência Renal Crônica/complicações , Acetilcisteína/uso terapêutico , Doenças Cardiovasculares/etiologia , Resistência a Medicamentos , Ácido Fólico/uso terapêutico , Humanos , Diálise Renal , Fatores de Risco
15.
Blood Purif ; 31(1-3): 102-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21228576

RESUMO

Hydrogen sulfide (H(2)S) is a poisonous gas which can be lethal. However, it is also produced endogenously, thus belonging to the family of gasotransmitters along with nitric oxide and carbon monoxide. H(2)S is in fact involved in mediating several signaling and cytoprotective functions, for example in the nervous, cardiovascular, and gastrointestinal systems, such as neuronal transmission, blood pressure regulation and insulin release, among others. When increased, it can mediate inflammation and apoptosis, with a role in shock. When decreased, it can be involved in atherosclerosis, hypertension, myocardial infarction, diabetes, sexual dysfunction, and gastric ulcer; it notably interacts with the other gaseous mediators. Cystathionine γ-lyase, cystathionine ß-synthase, and 3-mercaptopyruvate sulfurtransferase are the principal enzymes involved in H(2)S production. We have recently studied H(2)S metabolism in the plasma of chronic hemodialysis patients and reported that its levels are significantly decreased. The plausible mechanism lies in the transcription inhibition of the cystathionine γ-lyase gene. The finding could be of importance considering that hypertension and high cardiovascular mortality are characteristic in these patients.


Assuntos
Sistema Cardiovascular/metabolismo , Sulfeto de Hidrogênio/efeitos adversos , Sulfeto de Hidrogênio/metabolismo , Uremia/metabolismo , Cistationina gama-Liase/metabolismo , Humanos , Hipertensão/metabolismo , Diálise Renal
16.
J Nephrol ; 23 Suppl 16: S92-6, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21170893

RESUMO

Hydrogen sulfide, H2S, is the third endogenous gas with cardiovascular properties (the others are nitric oxide and carbon monoxide). In fact, among other important signaling functions, H2S plays a key role in regulating blood pressure. Cystathionine ß-synthase, cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase are the principal enzymes devoted to H2S formation. We have recently shown that H2S levels are decreased in patients on chronic hemodialysis through the transcriptional deregulation of the CSE gene, hinting at the possibility that a link exists between this finding and hypertension and the high cardiovascular mortality typical of these patients.


Assuntos
Sulfeto de Hidrogênio/metabolismo , Diálise Renal , Animais , Doenças Cardiovasculares/etiologia , Cistationina beta-Sintase/genética , Cistationina beta-Sintase/fisiologia , Humanos
17.
J Ren Nutr ; 20(5 Suppl): S11-4, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20797558

RESUMO

Hydrogen sulfide, H(2)S, is the third endogenous gas with cardiovascular properties, after nitric oxide and carbon monoxide. H(2)S is a potent vasorelaxant, and its deficiency is implicated in the pathogenesis of hypertension and atherosclerosis. Cystathionine beta-synthase, cystathionine gamma-lyase, and 3-mercaptopyruvate sulfurtransferase catalyze H(2)S formation. Chronic kidney disease is characterized by high prevalence of hyperhomocysteinemia, hypertension, and high cardiovascular mortality, especially in hemodialysis patients. H(2)S levels are decreased in hemodialysis patients through transcriptional deregulation of genes encoding for the H(2)S-producing enzymes. Potential implications relate to the pathogenesis of the manifestations of the uremic syndrome, such as hypertension and atherosclerosis.


Assuntos
Sulfeto de Hidrogênio/sangue , Falência Renal Crônica/sangue , Diálise Renal , Vasodilatadores , Doenças Cardiovasculares/etiologia , Cistationina beta-Sintase/metabolismo , Cistationina gama-Liase/metabolismo , Humanos , Sulfeto de Hidrogênio/metabolismo , Hiper-Homocisteinemia/etiologia , Hipertensão/etiologia , Falência Renal Crônica/complicações , Sulfurtransferases/metabolismo , Uremia/sangue , Uremia/enzimologia
18.
Semin Dial ; 22(4): 351-6, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19708980

RESUMO

Hyperhomocysteinemia is an independent cardiovascular risk factor, according to most observational studies and to studies using the Mendelian randomization approach, utilizing the common polymorphism C677T of methylene tetrahydrofolate reductase. In contrast, the most recent secondary preventive intervention studies, in the general population and in chronic kidney disease (CKD) and uremia, which are all negative (with the possible notable exception of stroke), point to other directions. However, all trials use folic acid in various dosages as a means to reduce homocysteine levels, with the addition of vitamins B6 and B12. It is possible that folic acid has negative effects, which offset the benefits; alternatively, homocysteine could be an innocent by-stander, or a surrogate of the real culprit. The latter possibility leads us to the search for potential candidates. First, the accumulation of homocysteine in blood leads to an intracellular increase of S-adenosylhomocysteine (AdoHcy), a powerful competitive methyltransferase inhibitor, which by itself is considered a predictor of cardiovascular events. DNA methyltransferases are among the principal targets of hyperhomocysteinemia, as studies in several cell culture and animal models, as well as in humans, show. In CKD and in uremia, hyperhomocysteinemia and high intracellular AdoHcy are present and are associated with abnormal allelic expression of genes regulated through methylation, such as imprinted genes, and pseudoautosomal genes, thus pointing to epigenetic dysregulation. These alterations are susceptible to reversal upon homocysteine-lowering therapy obtained through folate administration. Second, it has to be kept in mind that homocysteine is mainly protein-bound, and its effects could be linked therefore to protein homocysteinylation. In this respect, increased protein homocysteinylation has been found in uremia, leading to alterations in protein function.


Assuntos
Hiper-Homocisteinemia/complicações , Uremia/etiologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/fisiopatologia , Humanos , Hiper-Homocisteinemia/metabolismo , Hiper-Homocisteinemia/fisiopatologia , Fatores de Risco , Uremia/metabolismo , Uremia/fisiopatologia
19.
Nephrol Dial Transplant ; 24(12): 3756-63, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19654230

RESUMO

BACKGROUND: Hydrogen sulphide, H(2)S, is the third endogenous gas with putative cardiovascular properties, after nitric oxide and carbon monoxide. H(2)S is a vasorelaxant, while H(2)S deficiency is implicated in the pathogenesis of hypertension and atherosclerosis. Cystathionine beta-synthase (CBS), cystathionine gamma-lyase (CSE) and 3-mercaptopyruvate sulphurtransferase (MPS) catalyze H(2)S formation, with different relative efficiencies. Chronic kidney disease (CKD) is characterized by elevation of both plasma homocysteine and cysteine, which are substrates of these enzymes, and by a high prevalence of hypertension and cardiovascular mortality, particularly in the haemodialysis stage. It is possible that the H(2)S-generating pathways are altered as well in this patient population. METHODS: Plasma H(2)S levels were measured with a common spectrophotometric method. This method detects various forms of H(2)S, protein-bound and non-protein-bound. Blood sulphaemoglobin, a marker of chronic exposure to H(2)S, was also measured, as well as related sulphur amino acids, vitamins and transcriptional levels of relevant genes, in haemodialysis patients and compared to healthy controls. RESULTS: Applying the above-mentioned methodology, H(2)S levels were found to be decreased in patients. Sulphaemoglobin levels were significantly lower as well. Plasma homocysteine and cysteine were significantly higher; vitamin B(6), a cofactor in H(2)S biosynthesis, was not different. H(2)S correlated negatively with cysteine levels. CSE expression was significantly downregulated in haemodialysis patients. CONCLUSIONS: Transcriptional deregulation of genes encoding for H(2)S-producing enzymes is present in uraemia. Although the specificity of the method employed for H(2)S detection is low, the finding that H(2)S is decreased is complemented by the lower sulphhaemoglobin levels. Potential implications of this study relate to the pathogenesis of the uraemic syndrome manifestations, such as hypertension and atherosclerosis.


Assuntos
Sulfeto de Hidrogênio/metabolismo , Falência Renal Crônica/enzimologia , Falência Renal Crônica/genética , Diálise Renal , Adulto , Idoso , Feminino , Humanos , Falência Renal Crônica/sangue , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Transcrição Gênica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...