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1.
Econ Hum Biol ; 37: 100833, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31911379

RESUMO

In the process of fertility decline, the role and participation of men have hardly been considered in the demographic literature. It has grown only as fertility was dropping dramatically in most Western countries, but very little has been done to analyze such an issue in historical populations. Based on individual-level data, the present paper aims at investigating, by means of hazard models, the role of males in the reproductive pattern of the pre-transitional population of Alghero, Sardinia (1866-1935). The results show a slower decrease of male fertility (-23% at 40-49 years; around -50% at 50+) compared to female fertility (about -40% already at 35-49 years), with significant differentials by socioeconomic status (SES). Wealthier men present, in fact, lower fertility than poorest ones, with a gap that, however, reduces with age and even reverses at 50+ years. The reason for such a change is likely to be partly associated with the better health conditions of the wealthy group, developed especially in adulthood, given the absence of a significant relationship between height and fertility SES differentials.


Assuntos
Fertilidade , Fatores Socioeconômicos/história , Adulto , Fatores Etários , Países em Desenvolvimento , Feminino , História do Século XIX , História do Século XX , Humanos , Masculino , Pessoa de Meia-Idade , Dinâmica Populacional , Pobreza/estatística & dados numéricos
2.
Phys Rev Lett ; 123(23): 231108, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31868444

RESUMO

Current interferometric gravitational-wave detectors are limited by quantum noise over a wide range of their measurement bandwidth. One method to overcome the quantum limit is the injection of squeezed vacuum states of light into the interferometer's dark port. Here, we report on the successful application of this quantum technology to improve the shot noise limited sensitivity of the Advanced Virgo gravitational-wave detector. A sensitivity enhancement of up to 3.2±0.1 dB beyond the shot noise limit is achieved. This nonclassical improvement corresponds to a 5%-8% increase of the binary neutron star horizon. The squeezing injection was fully automated and over the first 5 months of the third joint LIGO-Virgo observation run O3 squeezing was applied for more than 99% of the science time. During this period several gravitational-wave candidates have been recorded.

3.
Nitric Oxide ; 47: 25-33, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25795591

RESUMO

Hydrogen sulfide (H2S) and nitric oxide (NO) play pivotal roles in the cardiovascular system. Conflicting results have been reported about their cross-talk. This study investigated their interplays in coronary bed of normotensive (NTRs) and spontaneously hypertensive rats (SHRs). The effects of H2S- (NaHS) and NO-donors (sodium nitroprusside, SNP) on coronary flow (CF) were measured in Langendorff-perfused hearts of NTRs and SHRs, in the absence or in the presence of propargylglycine (PAG, inhibitor of H2S biosynthesis), L-NAME (inhibitor of NO biosynthesis), ODQ (inhibitor of guanylate cyclase), L-Cysteine (substrate for H2S biosynthesis) or L-Arginine (substrate for NO biosynthesis). In NTRs, NaHS and SNP increased CF; their effects were particularly evident in Angiotensin II (AngII)-contracted coronary arteries. The dilatory effects of NaHS were abolished by L-NAME and ODQ; conversely, PAG abolished the effects of SNP. In SHRs, high levels of myocardial ROS production were observed. NaHS and SNP did not reduce the oxidative stress, but produced clear increases of the basal CF. In contrast, in AngII-contracted coronary arteries of SHRs, significant hyporeactivity to NaHS and SNP was observed. In SHRs, the vasodilatory effects of NaHS were only modestly affected by L-NAME and ODQ; PAG poorly influenced the effects of SNP. Then, in NTRs, the vascular actions of H2S required NO and vice versa. By contrast, in SHRs, the H2S-induced actions scarcely depend on NO release; as well, the NO effects are largely H2S-independent. These results represent the first step for understanding pathophysiological mechanisms of NO/H2S interplays under both normotensive and hypertensive conditions.


Assuntos
Vasos Coronários/metabolismo , Sulfeto de Hidrogênio/metabolismo , Hipertensão , Óxido Nítrico/metabolismo , Animais , Vasos Coronários/efeitos dos fármacos , Sulfeto de Hidrogênio/farmacologia , Masculino , Nitroprussiato/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo
4.
Med Res Rev ; 35(3): 520-53, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25346462

RESUMO

Brief periods of ischemia are known to confer to the myocardium an increased resistance to the injury due to a later and more prolonged ischemic episode. This phenomenon, known as ischemic preconditioning (IPreC), is ensured by different biological mechanisms. Although an exhaustive comprehension of them has not been reached yet, it is widely accepted that mitochondria are pivotally involved in controlling cell life and death, and thus in IPreC. Among the several signaling pathways involved, as triggers and/or end effectors, in the mitochondrial mechanisms of cardioprotection, an important role is played by the activation of potassium channels located in the mitochondrial inner membrane (mitoK) of cardiomyocytes. Presently, different types of mitoK channels have been recognized in the heart, such as ATP-sensitive (mitoKATP) and calcium-activated (mitoBK(Ca) and mitoSK(Ca)) potassium channels. Consistently, drugs modulating mitoK, on one hand, have been employed as useful experimental tools for early basic studies on IPreC. On the other hand, activators of mitoK are promising and innovative therapeutic agents for limiting the myocardial injury due to ischemic episodes. In this review, we report the experimental evidence supporting the role of mitoK in signaling pathways in the mechanisms of cardioprotection and an overview on the most important molecules acting as modulators of these channels, with their profiles of selectivity. Some innovative pharmaceutical strategies for mitochondriotropic drugs have been also reported. Finally, an appendix describing the main experimental approaches usually employed to study mitoK in isolated mitochondria or in intact cells has been added.


Assuntos
Cardiotônicos/química , Mitocôndrias/metabolismo , Canais de Potássio/metabolismo , Animais , Cálcio/química , Morte Celular , Humanos , Pós-Condicionamento Isquêmico , Precondicionamento Isquêmico , Camundongos , Mitocôndrias/patologia , Mitocôndrias Cardíacas/patologia , Miocárdio/patologia , Traumatismo por Reperfusão , Transdução de Sinais
5.
Pharmacol Res ; 78: 1-9, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24083950

RESUMO

Selective cyclooxygenase 2 (COX2) inhibitors (COXIBs) are effective anti-inflammatory and analgesic drugs with improved gastrointestinal (GI) safety compared to nonselective nonsteroidal anti-inflammatory drugs known as traditional (tNSAIDs). However, their use is associated with a cardiovascular (CV) hazard (i.e. increased incidence of thrombotic events and hypertension) due to the inhibition of COX2-dependent vascular prostacyclin. Aiming to design COX2-selective inhibitors with improved CV safety, new NO-releasing COXIBs (NO-COXIBs) have been developed. In these hybrid drugs, the NO-mediated CV effects are expected to compensate for the COXIB-mediated inhibition of prostacyclin. This study evaluates the potential CV beneficial effects of VA694, a promising NO-COXIB, the anti-inflammatory effects of which have been previously characterized in several in vitro and in vivo experimental models. When incubated in hepatic homogenate, VA694 acted as a slow NO-donor. Moreover, it caused NO-mediated relaxant effects in the vascular smooth muscle. The chronic oral administration of VA694 to young spontaneously hypertensive rats (SHRs) significantly slowed down the age-related development of hypertension and was associated with increased plasma levels of nitrates, stable end-metabolites of NO. Furthermore, a significant improvement of coronary flow and a significant reduction of endothelial dysfunction were observed in SHRs submitted to chronic administration of VA694. In conclusion, VA694 is a promising COX2-inhibiting hybrid drug, showing NO releasing properties which may mitigate the CV deleterious effects associated with the COX2-inhibition.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Inibidores de Ciclo-Oxigenase 2/farmacologia , Fatores Relaxantes Dependentes do Endotélio/administração & dosagem , Endotélio/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Nitratos/farmacologia , Óxido Nítrico/administração & dosagem , Pirróis/farmacologia , Animais , Anti-Inflamatórios não Esteroides/química , Pressão Sanguínea/efeitos dos fármacos , Vasos Coronários/efeitos dos fármacos , Inibidores de Ciclo-Oxigenase 2/química , Endotélio/patologia , Fatores Relaxantes Dependentes do Endotélio/farmacologia , Hipertensão/sangue , Masculino , Nitratos/sangue , Nitratos/química , Óxido Nítrico/farmacologia , Nitritos/sangue , Pirróis/química , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Fluxo Sanguíneo Regional/efeitos dos fármacos
6.
Biochem Pharmacol ; 85(11): 1634-43, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23567997

RESUMO

Naringenin (NAR), flavonoid abundant in the genus Citrus, has been reported to interact with the large-conductance calcium-activated potassium channels (BK). Since activators of BK channels expressed in cardiac mitochondria trigger protective effects in several models of myocardial ischemia/reperfusion (I/R), this work aimed to evaluate the potential cardioprotective effects of NAR and the involvement of mitochondrial BK channels. In an in vivo model of acute infarct in rats, NAR (100mg/kg i.p.) significantly reduced the heart injury induced by I/R. This effect was antagonized by the selective BK-blocker paxilline (PAX). The cardioprotective dose of NAR did not cause significant effects on the blood pressure. In Largendorff-perfused rat hearts submitted to ischemia/reperfusion, NAR improved the post-ischemic functional parameters (left ventricle developed pressure and dP/dt) with lower extension of myocardial injury. On isolated rat cardiac mitochondria, NAR caused a concentration-dependent depolarization of mitochondrial membrane and caused a trans-membrane flow of thallium (potassium-mimetic cation). Both these effects were antagonized by selective blockers of BK channels. Furthermore, NAR half-reduced the calcium accumulation into the matrix of cardiac mitochondria exposed to high calcium concentrations. In conclusion, NAR exerts anti-ischemic effects through a "pharmacological preconditioning" that it is likely to be mediated, at least in part, by the activation of mitochondrial BK channels.


Assuntos
Cardiotônicos/farmacologia , Flavanonas/farmacologia , Canais de Potássio Ativados por Cálcio de Condutância Alta/agonistas , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Animais , Pressão Sanguínea , Cálcio/metabolismo , Transporte de Íons , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias Cardíacas/metabolismo , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Potássio/metabolismo , Ratos , Ratos Wistar
7.
Pharmacol Res ; 70(1): 27-34, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23287425

RESUMO

Hydrogen sulphide (H2S) has been recently hypothesized to be an endogenous adipocyte-derived relaxing factor, evoking vasorelaxation of conductance and resistance vessels. Although the activation of ATP-sensitive potassium channels is known to play a central role in H2S-induced vasorelaxation, activation of vascular Kv7 voltage-gated potassium channels has also been suggested. To investigate this possibility, the ability of selective activators and blockers of distinct classes of potassium channels to affect vasodilation induced by the H2S-donor NaHS, as well as NaHS-induced Rb(+) efflux in endothelium-denuded rat aortic rings, was investigated. NaHS-induced changes of membrane potential were fluorimetrically assessed on human vascular smooth muscle (VSM) cells. Modulation of Kv7.4 channels by NaHS was assessed by electrophysiological studies, upon their heterologous expression in CHO cells. In isolated aortic rings, NaHS evoked vasorelaxing responses associated with an increase of Rb(+)-efflux. NaHS promoted membrane hyperpolarization of human VSM cells. These effects were antagonized by selective blockers of Kv7 channels. The H2S-donor caused a left-shift of current activation threshold of Kv7.4 channels expressed in CHO cells. Altogether, these results suggest that the activation of Kv7.4 channels is a key mechanism in the vascular effects of H2S. Given the relevant roles played by Kv7.4 channels in VSM contractility and by H2S in circulatory homeostasis regulation, these findings provide interesting insights to improve our understanding of H2S pathophysiology and to focus on Kv7.4 channels as novel targets for therapeutic approaches via the "H2S-system".


Assuntos
Aorta/efeitos dos fármacos , Sulfeto de Hidrogênio/farmacologia , Canais de Potássio KCNQ/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , Sulfetos/farmacologia , Vasodilatação/efeitos dos fármacos , Animais , Aorta/metabolismo , Linhagem Celular , Interpretação Estatística de Dados , Relação Dose-Resposta a Droga , Endotélio Vascular/fisiologia , Humanos , Técnicas In Vitro , Canais de Potássio KCNQ/biossíntese , Masculino , Potenciais da Membrana/efeitos dos fármacos , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Ratos , Ratos Wistar , Vasoconstritores/farmacologia
8.
Br J Pharmacol ; 168(1): 266-75, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22924744

RESUMO

BACKGROUND AND PURPOSE: An important objective in asthma therapy is to prevent the accelerated growth of airway smooth muscle cells which leads to hyperplasia and bronchial hyperreactivity. We investigated the effect of combination of salbutamol and PPARγ agonists on growth factor-stimulated human bronchial smooth muscle cell (BSMC) proliferation. EXPERIMENTAL APPROACH: Synergism was quantified by the combination index-isobologram method. Assays used here included analyses of growth inhibition, cell viability, DNA fragmentation, gene transcription, cell cycle and protein expression. KEY RESULTS: The PPARγ gene was highly expressed in BSMC and the protein was identified in cell nuclei. Single-agent salbutamol or PPARγ agonists prevented growth factor-induced human BSMC proliferation within a micromolar range of concentrations through their specific receptor subtypes. Sub-micromolar levels of combined salbutamol-PPARγ agonist inhibited growth by 50% at concentrations from ∼2 to 12-fold lower than those required for each drug alone, without induction of apoptosis or necrosis. Combination treatments also promoted cell cycle arrest at the G1/S transition phase and inhibition of ERK phosphorylation. CONCLUSIONS AND IMPLICATIONS: The synergistic interaction between PPARγ agonists and ß(2) -adrenoceptor agonists on airway smooth muscle cell proliferation highlights the anti-remodelling potential of this combination in chronic lung diseases.


Assuntos
Albuterol/farmacologia , Brônquios/efeitos dos fármacos , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/efeitos dos fármacos , Receptores Ativados por Proliferador de Peroxissomo/farmacologia , Tiazolidinedionas/farmacologia , Remodelação das Vias Aéreas/efeitos dos fármacos , Brônquios/citologia , Brônquios/metabolismo , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Sinergismo Farmacológico , Humanos , Miócitos de Músculo Liso/metabolismo , Rosiglitazona
9.
Curr Med Chem ; 19(20): 3325-36, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22680638

RESUMO

Hydrogen sulphide (H(2)S) is now viewed as an important endogenous gasotransmitter, which exhibits many beneficial effects on the cardiovascular system. H(2)S is biosynthesized in mammalian tissues by both non-enzymatic processes and several enzymatic pathways ensured by cystathionine-ß-synthase and cystathionine-γ-lyase. H(2)S is endowed with the antioxidant properties of inorganic and organic sulphites, being a scavenger of reactive oxygen species. Furthermore, H(2)S triggers other important effects and the activation of ATP-sensitive potassium channels (KATP) accounts for its vasorelaxing and cardioprotective effects. H(2)S also inhibits smooth muscle proliferation and platelet aggregation. Conversely, the impairment of H(2)S contributes to the pathogenesis of hypertension and is involved in cardiovascular complications associated with diabetes mellitus. There is also evidence of a link between H(2)S and endothelial nitric oxide (NO). Recent observations indicate a possible pathogenic link between deficiencies of H(2)S activity and the progress of endothelial dysfunction. These biological aspects of endogenous H(2)S led to consider this mediator as "the new NO" and to evaluate new attractive opportunities to develop innovative classes of drugs. In this review, the main roles played by H(2)S in the cardiovascular system and the first examples of H(2)S-donor drugs are discussed. Some hybrid drugs are also addressed in this review. In such compounds opportune H(2)S-releasing moieties are conjugated to well-known drugs to improve their pharmacodynamic profile or to reduce the potential for adverse effects.


Assuntos
Sistema Cardiovascular/metabolismo , Sulfeto de Hidrogênio/metabolismo , Animais , Anti-Inflamatórios não Esteroides/metabolismo , Anti-Inflamatórios não Esteroides/farmacologia , Circulação Sanguínea/efeitos dos fármacos , Sistema Cardiovascular/efeitos dos fármacos , Linhagem Celular , Humanos
10.
Eur Respir J ; 37(6): 1494-502, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21148223

RESUMO

Microparticles (MP) are phospholipid vesicles shed by cells upon activation or apoptosis. Monocyte-derived MP upregulate the synthesis of proinflammatory mediators by lung epithelial cells; the molecular bases of such activity are unknown. Peroxisome proliferator-activated receptors (PPAR) have been demonstrated to be involved in the modulation of nuclear factor (NF)-κB transcriptional activity and inflammation. We investigated whether the upregulation of the synthesis of proinflammatory cytokines by human lung epithelial cells induced by monocyte/macrophage-derived MP involves NF-κB activation and is modulated by PPAR-γ. MP were generated by stimulation of human monocytes/macrophages with the calcium ionophore, A23187. MP were incubated with human lung epithelial cells. NF-κB translocation was assessed by electrophoretic mobility shift assay. Interleukin (IL)-8 and monocyte chemotactic protein (MCP)-1 synthesis was assessed by ELISA and RT-PCR. Stimulation of A549 alveolar cells with monocyte/macrophage-derived MP caused an increase in NF-κB activation and IL-8 and MCP-1 synthesis that was inhibited by pre-incubation with the PPAR-γ agonists, rosiglitazone and 15-deoxy-Δ12,14-prostaglandin-J2. Parallel experiments with normal human bronchial epithelial cells largely confirmed the results. The effects of PPAR-γ agonists were reversed by the specific antagonist, GW9662. Upregulation of the synthesis of proinflammatory mediators by human lung epithelial cells induced by monocyte/macrophage-derived MP is mediated by NF-κB activation through a PPAR-γ dependent pathway.


Assuntos
Micropartículas Derivadas de Células/fisiologia , Monócitos/fisiologia , NF-kappa B/metabolismo , PPAR gama/metabolismo , Pneumonia/patologia , Anilidas/farmacologia , Brônquios/efeitos dos fármacos , Calcimicina/farmacologia , Linhagem Celular , Células Cultivadas , Quimiocina CCL2/biossíntese , Humanos , Interleucina-8/biossíntese , Ionóforos/farmacologia , PPAR gama/agonistas , Pneumonia/metabolismo , Prostaglandina D2/análogos & derivados , Prostaglandina D2/farmacologia , Rosiglitazona , Tiazolidinedionas/farmacologia , Regulação para Cima/efeitos dos fármacos
11.
Am J Phys Anthropol ; 141(2): 290-6, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19902452

RESUMO

Military medical information and data from civil registers of death and marriage have been used to study the role of physical characteristics and health conditions in explaining access to marriage for the male population of Alghero, a small city located in Sardinia Island (Italy), at the turn of 19th century. Literature data about contemporary populations have already demonstrated the influence of somatic traits in the mate choice. The results presented here show that men with low height and poor health status at the age of 20 were negatively selected for marriage. This holds true also in a society where families often arranged marriages for their children. This pattern of male selection on marriage was found to be particularly marked among the richest and wealthiest SES groups. Our hypothesis is that this social group carefully selected for marriage those individuals who were apparently healthier and therefore more likely to guarantee good health status and better life conditions to offspring. In evolutionary terms, the mate choice component of sexual selection suggests that the height of prospective partners could be claimed as one of the determinants, along with other environmental causes, of the observed higher stature of men belonging to the wealthiest social strata of the Alghero population.


Assuntos
Nível de Saúde , Casamento/estatística & dados numéricos , Comportamento Sexual/psicologia , Cônjuges , História do Século XIX , História do Século XX , Humanos , Itália , Modelos Logísticos , Masculino , Fatores Socioeconômicos , Estatísticas Vitais
12.
Arch Gynecol Obstet ; 278(4): 309-13, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18236055

RESUMO

AIM: We aim to assess serum total homocysteine (tHcy) associations with metabolic syndrome components and B-vitamins in women with gestational diabetes mellitus (GDM). METHODS: We studied 61 consecutive pregnant women, 44 with GDM and 17 with normal glucose tolerance (CG). Serum homocysteine levels were analyzed by ELISA, using Bio-Rad reagents. Serum folates and vitamin B(12) concentrations were determined by chemiluminescent immunoassay, free fatty acids (FFA) and lipids enzymatically. RESULTS: Serum homocysteine levels were similar in both the GDM and the CG groups (8+/-2.0 vs 7.4+/-1.1 micromol/l, respectively). Women with GDM in comparison to CG women were characterized by higher values of homeostasis model of insulin resistance (HOMA-IR) (2.8+/-1.7 vs 1.6+/-0.9, P<0.01), serum triglycerides (2.7+/-0.9 vs 1.9+/-0.5 mmol/l, P<0.01) and FFA (0.6+/-0.2 vs 0.46+/-0.2 mmol/l, P<0.05). In GDM women serum tHcy correlated with vitamin B(12) (r= -0.47, P<0.01) and folates (r= -0.51, P<0.001); in CG women with HOMA-IR, a marker of insulin resistance (r= -0.49, P<0.05). In multiple regression analysis with serum tHcy as a dependent variable, folate and vitamin B(12) entered the analysis in GDM women (beta= -0.42 and -0.34, respectively, P<0.05), whereas in CG cystatin C and HOMA-IR entered the analysis (P<0.05). CONCLUSIONS: In women with GDM, serum homocysteine is significantly associated with vitamin B(12) and folate levels, while in healthy pregnant women with HOMA-IR and with kidney function. The results suggest the importance of the B-group vitamins in regulation of serum tHcy levels in women with insulin resistance/gestational diabetes, what might be relevant in protection against pregnancy complications associated with elevated tHcy in GDM women.


Assuntos
Diabetes Gestacional/sangue , Ácido Fólico/sangue , Homocisteína/sangue , Vitamina B 12/sangue , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Resistência à Insulina , Gravidez
13.
J Appl Toxicol ; 27(3): 270-5, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17265420

RESUMO

Experimental approaches on anaesthetised guinea pigs have been shown recently to be satisfactorily predictive of the torsadogenic risk of drugs. This work aimed at obtaining additional data, for a further understanding of the reliability and/or the limits of this model. Clonidine (non-torsadogenic in humans) induced a lengthening of the ECG parameter of RR in anaesthetised guinea pigs, without any corresponding increase of QT (corrected by the algorithms of Bazett and Fridericia). Thus, 'QT correct' prolonging effects produced by drugs torsadogenic in humans, on the guinea pig model are primarily due to inhibition of cardiac repolarisation. The corresponding RR prolongation is a consequence (not the cause) of this primary effect. Astemizole, haloperidol and terfenadine, torsadogenic in humans, produced in Langendorff perfused guinea pig hearts a prolongation of the QT interval. Chlorprotixene (non-torsadogenic) did not produce any significant effect on QT. These results are fully consistent with previous observations in anaesthetised guinea pigs. In Langendorff perfused hearts, pentobarbital does not affect cardiac repolarisation and does not potentiate the QT-prolonging effect of astemizole. Together with the findings reported by many authors, these data suggest that ECG recording in anaesthetised guinea pigs is a reliable model for cardiac safety studies evaluating the influence of drugs on the repolarisation process.


Assuntos
Coração/efeitos dos fármacos , Síndrome do QT Longo/induzido quimicamente , Torsades de Pointes/induzido quimicamente , Animais , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/toxicidade , Astemizol/administração & dosagem , Astemizol/toxicidade , Clonidina/administração & dosagem , Clonidina/toxicidade , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/induzido quimicamente , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/fisiopatologia , Eletrocardiografia/efeitos dos fármacos , Cobaias , Haloperidol/administração & dosagem , Haloperidol/toxicidade , Coração/fisiopatologia , Técnicas In Vitro , Injeções Intravenosas , Síndrome do QT Longo/fisiopatologia , Perfusão/métodos , Terfenadina/administração & dosagem , Terfenadina/toxicidade , Torsades de Pointes/fisiopatologia
14.
J Ethnopharmacol ; 110(1): 148-53, 2007 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-17052874

RESUMO

Echinacea is one of the most widely used alternative medicine in the world. Intake of Echinacea preparations is common among patients with advanced malignancies enrolled onto phase I chemotherapy trials; however, to our knowledge, no data are available regarding the possible direct effect of Echinacea species on human cancer cells. The purpose of the present study was to investigate potential in vitro cytotoxic and pro-apoptotic properties of hexanic root extract of the three medicinal Echinacea (Asteraceae) species (Echinacea pallida (Nutt.) Nutt., Echinacea angustifolia DC. var. angustifolia, Echinacea purpurea (L.) Moench.) on the human pancreatic cancer MIA PaCa-2 and colon cancer COLO320 cell lines. We demonstrated, for the first time, that all the three species reduced cell viability in a concentration- and time-dependent manner; Echinacea pallida was the most active species with IC(50)s of 46.41+/-0.87 and 10.55+/-0.70 microg/ml in MIA PaCa-2 and COLO320 cells, respectively. Echinacea pallida extract was able to induce apoptosis by increasing significantly caspase 3/7 activity and promoting nuclear DNA fragmentation. These results represent the starting point to establish viable scientific evidence on the possible role of Echinacea species in medical oncology.


Assuntos
Anti-Infecciosos
15.
Diabet Med ; 22(11): 1574-80, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16241924

RESUMO

AIMS: To study the effect of parity on impairment of insulin sensitivity during pregnancy and on the risk of gestational diabetes (GDM). METHODS: We studied the relationship between parity and peripheral insulin sensitivity index (ISI(OGTT)) or GDM in 1880 caucasian women, who underwent a 100-g, 3-h oral glucose tolerance test (OGTT) between the 24th and 28th gestational week and in 75 women who underwent an OGTT in two consecutive pregnancies. A proxy for beta-cell function (basal plasma C peptide/fasting plasma glucose; CP/FPG) was also measured. RESULTS: By univariate analysis parity was related to decreased ISI(OGTT) and to increased CP/FPG in those with parity > 3 and likewise GDM, diagnosed in 124 women (6.58%), was linearly related to parity (P = 0.0034) and strongly age dependent. The relationships between parity and ISI(OGTT), CP/FPG and GDM were no longer significant after adjustment for age, pregestational body mass index (BMI), and weight gain. GDM was significantly related to age and pregestational weight, while ISI(OGTT) and CP/FPG were inversely related to prepregnancy BMI or weight gain. In comparison with the index pregnancy, the subsequent pregnancy was characterized by an increase in actual and prepregnancy BMI, in 2 h area under curve (AUC) glucose and by a decrease in ISI(OGTT) (P = 0.0001). The longer the time interval between pregnancies and the higher the increment in pregestational BMI or in weight gain during the pregnancy, the greater were the ISI(OGTT) decrease and 2-h AUC glucose increase. CONCLUSIONS: Parity is not directly linked to insulin sensitivity deterioration, to CP/FPG increase during pregnancy, or to GDM appearance, although it is linked through the mediation of progressive ageing and weight gain either before or during pregnancy, when there is a sufficiently long time interval between pregnancies.


Assuntos
Glicemia/metabolismo , Diabetes Gestacional/metabolismo , Resistência à Insulina/fisiologia , Paridade , Adulto , Índice de Massa Corporal , Estudos Transversais , Feminino , Teste de Tolerância a Glucose , Humanos , Gravidez , Terceiro Trimestre da Gravidez , Estudos Retrospectivos , Fatores de Risco , Aumento de Peso
16.
Curr Med Chem ; 11(20): 2691-706, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15544470

RESUMO

Many non-cardiovascular drugs of common clinical use cause, as an unwanted accessory property, the prolongation of the cardiac repolarisation process, due to the block of the HERG (Human Ether-a-go-go Related Gene) potassium channel, responsible for the repolarising I(Kr) current. This delayed cardiac repolarisation process can be often unmasked by a prolongation of the QT interval of the ECG. In these conditions, premature action potentials can generate morphologically anomalous after-polarisations, and trigger a dangerous kind of polymorphic ventricular tachyarrhythmia, known as torsade de pointes, which can evolve in ventricular fibrillation and death. The risk associated with the torsadogenic cardiotoxicity of drugs, which prolong the QT interval has been the topic of documents produced by many health authorities, giving important issues about the preclinical and clinical evaluation of cardiac safety. Besides, public and private research laboratories developed several experimental in vitro or in vivo strategies, aimed to an early recognition of the influence of a drug (or of a drug-candidate) on the HERG channel and/or on the cardiac repolarisation process. Also the identification of a possible pharmacophore model, common in all or at least in numerous torsadogenic drugs, could represent a first step for the development of useful in silico approaches, allowing a preliminary indication about the potential torsadogenic property of a given molecule. In this work, we described the electrophysiological basis of torsade de pointes and listed several pharmacological classes of torsadogenic drugs. Among them, we focused our attention on antipsychotics, with an accurate overview on the experimental and clinical reports about their torsadogenic properties. Moreover, a common structural feature exhibited by these drugs, despite of their remarkable chemical differences, is evidenced by a computational approach and is indicated as a possible "facilitating" requirement for their torsadogenic properties. Together with other remarks, coming from different computational studies, the individuation of a satisfactory "toxicophore" model could be greatly useful, for the theoretical prediction of torsadogenic properties of a given chemical moiety and for the design of new drugs devoid of such an undesired and potentially lethal side-effect.


Assuntos
Antipsicóticos/efeitos adversos , Antipsicóticos/química , Proteínas de Transporte de Cátions/metabolismo , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Torsades de Pointes/induzido quimicamente , Animais , Antipsicóticos/metabolismo , Proteínas de Transporte de Cátions/fisiologia , Canais de Potássio Éter-A-Go-Go , Humanos , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/fisiopatologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/fisiologia , Torsades de Pointes/fisiopatologia
17.
J Appl Toxicol ; 24(3): 217-22, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15211616

RESUMO

Many non-cardiovascular drugs can prolong the QT interval of the electrocardiogram (ECG); this is an accessory property not necessary for their pharmacological action and generally linked to the block of the potassium HERG channels and delayed cardiac repolarization. The QT prolongation can lead to a dangerous tachyarrhythmia, called torsade de pointes, and potentially to fatal ventricular fibrillation. The experimental approaches, aimed at an early identification of this undesidered property, often require sophisticated and expensive equipment or the use of superior animal species (dog, primates) that cannot be employed easily for ethical and/or economic reasons. This work aimed to study drug-induced QT prolongation in anaesthetized guinea-pigs and to evaluate the reliability of such an experimental approach to obtain a satisfying predictive parameter of the torsadogenicity of drugs in humans. Seven drugs that were torsadogenic in humans (astemizole, cisapride, haloperidol, quinidine, sotalol, terfenadine and thioridazine) and two that were non-torsadogenic (chlorprotixene and diazepam) were administered i.v. to guinea-pigs under pentobarbital anaesthesia. The ECGs were recorded by four electrodes inserted in the subcutaneous layer of the limbs. Both RR and QT intervals were measured in Leads II and III and then the correct QT values were calculated by Bazett and Fridericia algorithms (QTcB and QTcF, respectively). All the drugs, with the exception of chlorprotixene and diazepam, produced a dose-dependent prolongation of the QT and RR intervals and a significant increase of QTcB and QTcF values. It can be concluded that this method represents a rapid and low-cost procedure to evaluate the cardiac safety pro fi le in the preliminary screening of a high number of drugs or drug candidates.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Eletrocardiografia/efeitos dos fármacos , Torsades de Pointes/induzido quimicamente , Animais , Avaliação Pré-Clínica de Medicamentos/métodos , Cobaias , Masculino , Valor Preditivo dos Testes
18.
Calcif Tissue Int ; 73(2): 133-9, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14565594

RESUMO

Bisphosphonates have been widely used in the treatment of osteoporosis in women, whereas until now there have been few data on their use in men. The aim of this study was to evaluate the effect of a 3-year alendronate treatment on bone mineral density (BMD) and quantitative ultrasound (QUS) in men with primary osteoporosis. We studied 77 osteoporotic men (aged 57.1 +/- 10.8 yrs) who completed a 3-year treatment with alendronate (10 mg/day) plus calcium (1000 mg/day) (n = 39), or calcium alone (n = 38). At baseline and at a 12-month interval, we measured BMD at the lumbar spine and femur (femoral neck and total hip) by DXA (Hologic) and speed of sound (SOS), broadband ultrasound attenuation (BUA) and Stiffness (S) at the os calcis by Achilles plus (Lunar). Alendronate treatment had significantly increased lumbar spine BMD by 4.2% at year 1, by 6.3% at year 2, and 8.8% at year 3. BMD at the femoral neck and total hip had increased by 2.1% and 1.6% at year 1, by 3.2% and 2.9% at year 2, and by 4.2% and 3.9% at year 3, respectively. BUA and Stiffness showed a significant increase in the alendronate-treated group at year 2 (3.2% and 4.9%, respectively) and at year 3 (3.8% and 6%, respectively). BMD at the lumbar spine showed the best longitudinal sensitivity whereas longitudinal sensitivity of both QUS at the heel and femur BMD were similar. In conclusion, this study confirms that alendronate represents an important therapeutic advance in the management of male osteoporosis. BMD at the lumbar spine appears to be the best method for monitoring the effect of alendronate on bone mass in osteoporotic men.


Assuntos
Alendronato/uso terapêutico , Densidade Óssea/efeitos dos fármacos , Osteoporose/tratamento farmacológico , Ultrassonografia , Absorciometria de Fóton , Adulto , Idoso , Cálcio/uso terapêutico , Colo do Fêmur/diagnóstico por imagem , Colo do Fêmur/efeitos dos fármacos , Quadril/diagnóstico por imagem , Quadril/fisiologia , Humanos , Estudos Longitudinais , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Ultrassonografia/métodos
19.
Planta Med ; 69(7): 685-6, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12898432

RESUMO

The three medicinal species of the Echinacea genus, E. angustifolia DC., E. pallida (Nutt.) Nutt. and E. purpurea (L.) Moench were distinguished using the RAPD (random amplified polymorphic DNA) technique. Species-specific markers were identified from amplicons obtained with four of the twenty 10-mer primers contained in the Operon RAPD kit A. In particular, one marker was identified for E. angustifolia (OPA 20, 1800 pb) and E. pallida (OPA 10, 600 pb) and three markers for E. purpurea (OPA 11 : 1250 pb; OPA 17 : 750, 1800 pb). Genetic distance analysis indicated a high degree of difference among the three species with a relative lower difference between E. angustifolia and E. pallida.


Assuntos
Echinacea/genética , Echinacea/classificação , Plantas Medicinais/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico
20.
Eur J Pharmacol ; 437(1-2): 91-5, 2002 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11864645

RESUMO

The effects of silymarin on bronchoconstriction induced by antigen challenge and on post-antigen challenge hyperresponsiveness to substance P were evaluated in sensitized guinea-pigs. Silymarin significantly decreased the bronchoconstriction due to antigen administration in the early phase of the response. In contrast, the dose-response curve for substance P recorded 1 h after antigen challenge was not modified by pretreatment with silymarin. The influence of the flavonoid on hyperresponsiveness to histamine in propranolol- and PAF (platelet-activating factor)-treated animals was also assessed. Silymarin did not affect hyperresponsiveness to histamine induced by either propranolol or PAF although it had inhibitory activity on the bronchial contractile response to the autacoid. These results suggest that silymarin has a protective effect in the early phase of allergic asthma, an effect, which may be related to a negative influence of the flavonoid on bronchial responsiveness to histamine.


Assuntos
Broncoconstrição/efeitos dos fármacos , Histamina/administração & dosagem , Substâncias Protetoras/farmacologia , Silimarina/farmacologia , Animais , Hiper-Reatividade Brônquica/induzido quimicamente , Hiper-Reatividade Brônquica/fisiopatologia , Hiper-Reatividade Brônquica/prevenção & controle , Broncoconstrição/imunologia , Cobaias , Masculino , Ovalbumina/imunologia , Fator de Ativação de Plaquetas/administração & dosagem , Propranolol/administração & dosagem , Substância P/farmacologia , Fatores de Tempo
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