Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Med Eng Phys ; 47: 13-24, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28705512

RESUMO

Nitinol stents continuously experience loadings due to pulsatile pressure, thus a given stent design should possess an adequate fatigue strength and, at the same time, it should guarantee a sufficient vessel scaffolding. The present study proposes an optimization framework aiming at increasing the fatigue life reducing the maximum strut strain along the structure through a local modification of the strut profile.The adopted computational framework relies on nonlinear structural finite element analysis combined with a Multi Objective Genetic Algorithm, based on Kriging response surfaces. In particular, such an approach is used to investigate the design optimization of planar stent cell.The results of the strut profile optimization confirm the key role of a tapered strut design to enhance the stent fatigue strength, suggesting that it is possible to achieve a marked improvement of both the fatigue safety factor and the scaffolding capability simultaneously. The present study underlines the value of advanced engineering tools to optimize the design of medical devices.


Assuntos
Ligas/química , Prótese Vascular , Desenho Assistido por Computador , Desenho de Equipamento/métodos , Modelos Teóricos , Stents , Algoritmos , Força Compressiva , Simulação por Computador , Módulo de Elasticidade , Análise de Falha de Equipamento/métodos , Análise de Elementos Finitos , Pressão , Estresse Mecânico , Resistência à Tração
2.
J Neurol ; 253(7): 919-27, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16502217

RESUMO

White matter hyperintensities (WMHs) are a common finding in normal elderly persons. We studied the biological damage associated with WMHs by assessing the correspondence between WMH location and regional gray matter loss.Voxel-based morphometry of the gray matter was carried out with statistical parametric mapping on high resolution MR images.Neurologically intact persons with mainly anterior (frontal>parieto-occipital; N = 39) and mainly posterior WMHs (parieto- occipital>frontal; N = 14) were compared with a group devoid of WMHs (N = 80). Subjects with mainly frontal WMHs had bilateral frontal (medial, superior, and inferior gyri) atrophy in gray matter, while subjects with mainly posterior WMHs had more diffuse atrophy, involving mainly the frontal but also the right insular region. Our findings suggest that frontal WMHs are associated with frontal gray matter damage while parietooccipital WMHs seem to have a weaker and more diffuse impact on gray matter.


Assuntos
Envelhecimento/patologia , Atrofia/patologia , Encéfalo/patologia , Demência/patologia , Fibras Nervosas Mielinizadas/patologia , Adulto , Idoso , Atrofia/etiologia , Atrofia/fisiopatologia , Encéfalo/fisiopatologia , Mapeamento Encefálico , Córtex Cerebral/patologia , Córtex Cerebral/fisiopatologia , Transtornos Cognitivos/patologia , Transtornos Cognitivos/fisiopatologia , Transtornos Cognitivos/psicologia , Demência/fisiopatologia , Demência/psicologia , Feminino , Lobo Frontal/patologia , Lobo Frontal/fisiopatologia , Lateralidade Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/patologia , Vias Neurais/fisiopatologia , Testes Neuropsicológicos , Valor Preditivo dos Testes
3.
Matrix Biol ; 20(7): 419-27, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11691582

RESUMO

Gelatinase A (MMP-2) and gelatinase B (MMP-9) play a key role in the proteolytic cascade leading to ECM degradation during invasion and metastasis. The enzyme activity is regulated both at the intra- and extra-cellular level. Extracellular regulation is achieved mainly through the balance between proenzyme activation and inhibition, which appears to be altered in cancer patients. One of the mechanisms of MMP inhibition is the binding of the enzymes to appropriate tissue inhibitors (TIMP). In the recent literature, it has been suggested that MMP-2 and/or MMP-9 are indeed over-produced in many carcinomas, while the identity of the various enzymatic forms (latent, activated and enzyme/inhibitor complexes) remains to be elucidated. In this study we have analyzed the circulating forms of MMP-9 and MMP-2 in serum samples of patients with colon carcinoma, as well as the enzymatic activities present in tissue extracts from surgical fragments (primary tumor and its paired healthy tissue). Proteins were separated by means of mono-dimensional or bidimensional electrophoresis, and the enzymes detected by gelatin zymography and immunological assays. The results of densitometric analyses demonstrate that proMMP-9, but not proMMP-2, is significantly higher in the oncologic sera vs. the normal sera. In addition, several oligomeric circulating and tissue forms of MMP-9 are preferentially found in the oncologic samples, both in mono- and second-dimension zymograms. The activated forms of MMP-2 and MMP-9 are uniquely present in the primary tumor extracts, thus confirming the involvement of the tissue microenvironment in gelatinase activation and function.


Assuntos
Neoplasias do Colo/enzimologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Adulto , Neoplasias do Colo/sangue , Neoplasias do Colo/patologia , Densitometria , Eletroforese em Gel Bidimensional/métodos , Eletroforese em Gel de Poliacrilamida/métodos , Precursores Enzimáticos/sangue , Precursores Enzimáticos/isolamento & purificação , Precursores Enzimáticos/metabolismo , Humanos , Metaloproteinase 2 da Matriz/sangue , Metaloproteinase 2 da Matriz/isolamento & purificação , Metaloproteinase 9 da Matriz/sangue , Metaloproteinase 9 da Matriz/isolamento & purificação
4.
Aliment Pharmacol Ther ; 15(7): 953-8, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11421869

RESUMO

BACKGROUND: Therapy of chronic hepatitis C non- responders to interferon monotherapy with standard doses of interferon plus ribavirin is usually ineffective. AIM: To evaluate the efficacy and tolerability of high-dose prolonged combination retreatment in non- responder patients. METHODS: Patients were retreated for 6 months with 6 MU alphaIFN on alternate days and 1000 or 1200 mg/day ribavirin. HCV-RNA negative patients continued therapy for an additional 6 months. RESULTS: Forty patients (29 males, mean age 49.7 years, 34 genotype 1b, 11 with F3 fibrosis) were treated. At 6 months, 20 (50%) patients were HCV-RNA negative but six of them discontinued therapy because of adverse events. A sustained response was achieved in 28% of patients (11/40). A sustained response was more frequent among patients with genotype non-1b than in those with genotype 1b (67 vs. 21%, P=0.005) and clearance of HCV-RNA in the first 3 months had a high predictive value for sustained response (100% of sustained responders vs. 24% of non-responders, P=0.0001). CONCLUSIONS: High-dose prolonged combination therapy in non-responders to IFN monotherapy leads to a higher rate of sustained response than the standard combination regimen. Tolerability may be a rate-limiting factor. Maximal effectiveness can be predicted in patients with non-1b genotype and in those who clear HCV-RNA soon after starting retreatment.


Assuntos
Antivirais/farmacologia , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/farmacologia , Ribavirina/farmacologia , Adulto , Antivirais/administração & dosagem , Antivirais/uso terapêutico , Relação Dose-Resposta a Droga , Esquema de Medicação , Resistência a Medicamentos , Quimioterapia Combinada , Feminino , Fibrose , Genótipo , Hepatite C Crônica/patologia , Humanos , Interferon-alfa/administração & dosagem , Interferon-alfa/uso terapêutico , Masculino , Pessoa de Meia-Idade , RNA Viral/análise , Ribavirina/administração & dosagem , Ribavirina/uso terapêutico , Resultado do Tratamento
5.
Int J Cardiol ; 37(2): 223-30, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1452380

RESUMO

This study has been designed to evaluate whether duration and severity of obesity can influence left ventricular function response to exercise in obese subjects without other known cardiovascular risk factors such as hypertension, diabetes or hyperlipoproteinemia. A total of 29 obese subjects were included and they were divided, according to their body mass index and to Garrow's criteria as follows: Overweight or mildly obese subjects: body mass index from 25 to 30 kg/m2; moderately obese subjects: body mass index > 30 and < 40 kg/m2. Both obese groups were further subdivided according to their duration of obesity evaluated by accurate anamnesis in subgroup A (duration of obesity less than 120 months) and subgroup B (duration of obesity more than 120 months). Left ventricular ejection fraction was detected by blood pool gated radionuclide angiocardiography both at rest and after symptom-limited bicycle ergometer procedure. At peak exercise left ventricular ejection fraction increased significantly (p < 0.05) only in overweight subjects. Exercise produced an increase of left ventricular ejection fraction in 14 overweight and in 5 moderately obese subjects and a decrease in 2 moderately obese subjects. At peak exercise mean heart rate and mean blood pressure increased significantly (p < 0.001) in both groups. When obese subjects were subgrouped according to duration of obesity, left ventricular ejection fraction increased significantly (p < 0.05) only in overweight subjects with duration of obesity less than 120 months. Duration of obesity correlated inversely with percent change in left ventricular ejection fraction (EF) at peak exercise (delta EF) (r = -0.59; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Teste de Esforço , Obesidade/fisiopatologia , Função Ventricular Esquerda/fisiologia , Adulto , Índice de Massa Corporal , Débito Cardíaco/fisiologia , Ecocardiografia , Eletrocardiografia , Feminino , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
6.
Int J Clin Pharmacol Res ; 6(3): 199-211, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-2943685

RESUMO

Ketanserin is a new strong antiserotoninergic drug that, unlike the previous ones, is selective for 5-hydroxytryptamine receptors. This drug has been employed successfully in the treatment of arterial hypertension and of some peripheral vascular diseases. The authors are carrying out a trial on medium term treatment with ketanserin (K) or propranolol (P) in comparison with placebo, to evaluate their effects on blood pressure, haemocoagulative parameters and peripheral circulation. The trial is a double-blind cross-over random trial on subjects with mild or moderate hypertension. Until now 13 patients have ended the study; six of them are suffering from arteriosclerosis obliterans of the lower limbs at 1st or 2nd stage according to Fontaine. Both propranolol and ketanserin significantly reduced the blood pressure, although the decrease in systolic blood pressure was more evident after propranolol. Heart rate diminished significantly only after propranolol administration. The noninvasive, intermittent (every 30 min) monitoring of blood pressure showed a significant 24-hour reduction of blood pressure after administration of propranolol or ketanserin without significant changes of circadian behaviour of the blood pressure. After administration of ketanserin a slight improvement in peripheral circulation was demonstrated, evaluated by using strain-gauge plethysmography. As regards the results obtained for platelet function and other haemocoagulative parameters examined, adenosine diphosphate-induced platelet aggregation, adenosine diphosphate slope, collagen lag period, antithrombin III biological activity, and serum fibrinogen did not show noticeable modifications after treatment, while beta-thromboglobulin levels decreased slightly after ketanserin administration.


Assuntos
Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Perna (Membro)/irrigação sanguínea , Piperidinas/uso terapêutico , Adulto , Arteriosclerose Obliterante/complicações , Coagulação Sanguínea/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Método Duplo-Cego , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipertensão/complicações , Ketanserina , Masculino , Pessoa de Meia-Idade , Propranolol/uso terapêutico , Distribuição Aleatória , Fluxo Sanguíneo Regional/efeitos dos fármacos
7.
J Hypertens Suppl ; 3(3): S351-3, 1985 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2856736

RESUMO

Hypertension is associated with increased total peripheral vascular resistance. Calf blood flow and vascular resistance in two groups of hypertensives of different age has been evaluated: 85 middle-aged hypertensives (MH) and 25 elderly hypertensives (EH), and in two groups of 20 normotensive control subjects of similar age. Calf blood flow at rest (RF) and after ischaemia (PF) was determined by strain-gauge plethysmography. Basal (BVR) and minimal (MVR) vascular resistance were obtained by the mean blood pressure (MBP):RF and MBP:PF ratio. Blood flow at rest was reduced only in EH, while PF was significantly lower in MH and in EH in comparison with the respective controls. In parallel, BVR and MVR were higher in MH and in EH compared with controls. The increase of BVR and of MVR was more evident in EH. These results suggest that in EH there is an impairment of the calf maximal vasodilatation capacity, probably due to the long duration of hypertension.


Assuntos
Envelhecimento/fisiologia , Hipertensão/fisiopatologia , Perna (Membro)/irrigação sanguínea , Resistência Vascular/fisiologia , Adolescente , Adulto , Idoso , Pressão Sanguínea/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Isquemia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional/fisiologia
8.
J Hypertens Suppl ; 4(1): S103-6, 1986 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2939208

RESUMO

Ketanserin is a new potent antiserotonergic drug which, unlike previous ones, is selective for S2-serotoninergic receptors and does not have an agonist action. A trial was carried out on medium-term treatment with ketanserin or propranolol in subjects suffering from mild to moderate hypertension. The trial was designed as a double-blind crossover randomized study comparing either ketanserin or propranolol with placebo. Thirteen patients completed the study, which was divided into two groups (A and B). Systolic (SBP), diastolic (DBP) and mean (MBP) blood pressures were measured by non-invasive, intermittent ambulatory monitoring performed using a Pressurometer II, from Del Mar Avionics. Heart rate was measured using a continuous electrocardiogram monitoring. Systolic blood pressure was significantly reduced both after ketanserin (A:11.1%; B:10.8%) and propranolol (A:11.7%; B:11.8%) but in group A its decrease was more pronounced after propranolol (P less than 0.01). Diastolic blood pressure was significantly reduced both after ketanserin (A:11.5%; B:11.1%) and propranolol (A:11.4%; B:11.9%), as was MBP (A:11.9%; B:11.8% for ketanserin and A:11.9%; B:11.9% for propranolol). The heart rate diminished significantly only after propranolol administration (P less than 0.01). Ambulatory monitoring showed a significant 24-h reduction of SBP after administration of propranolol (P less than 0.0025) and ketanserin (A:P less than 0.0025, B: P less than 0.005). Diastolic blood pressure was also significantly reduced after ketanserin (P less than 0.0005) and propranolol (A: P less than 0.0025, B: P less than 0.0005). The heart rate obtained by continuous electrocardiogram monitoring diminished significantly only after propranolol administration (P less than 0.0005). No significant changes of circadian behaviour of blood pressure were observed.


Assuntos
Hipertensão/tratamento farmacológico , Piperidinas/uso terapêutico , Adulto , Assistência Ambulatorial , Determinação da Pressão Arterial/métodos , Feminino , Humanos , Ketanserina , Masculino , Pessoa de Meia-Idade , Placebos , Propranolol/uso terapêutico
9.
J Cell Physiol ; 203(1): 261-72, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15484219

RESUMO

The extravasation of metastatic cells is regulated by molecular events involving the initial adhesion of tumor cells to the endothelium and subsequently the migration of the cells in the host connective tissue. The differences in metastatic ability could be attributed to properties intrinsic of the various primary tumor types. Thus, the clonal selection of neoplastic cells during cancer progression results in cells better equipped for survival and formation of colonies in secondary sites. A cell line (T84SF) exhibiting an altered phenotypic appearance was selected from a colon cancer cell line (T84) by repetitive plating on TNFalpha-activated human endothelial cells and subsequent selection for adherent cells. Cell growth, motility, chemoinvasive abilities, tyrosine phosphorylation signaling, and the metastasis formation in nude mice of the two cell lines was compared. T84SF cells displayed in vitro an higher proliferation rate and a more invasive behavior compared to the parental cells while formed in vivo a greater number of metastatic colonies in nude mice. As concerns the signaling underlying the phenotypes of the selected cells, we examined the general tyrosine phosphorylation levels in both cell lines. Our results indicate that T84SF have an increased basal tyrosine phosphorylation of several proteins among which src kinase was identified. Treatment of cells with a specific inhibitor of src activity caused a greater in vitro inhibition of proliferation and invasive properties of T84 parental cells with respect to T84SF cells and diminished metastasis formation in vivo. Altogether, these data provide evidences that this new cell line may be valuable for identifying molecular mechanisms involved in the metastatic progression of colon cancer.


Assuntos
Comunicação Celular/fisiologia , Linhagem Celular Tumoral , Neoplasias do Colo/fisiopatologia , Neoplasias do Colo/secundário , Endotélio Vascular/citologia , Animais , Apoptose/fisiologia , Adesão Celular/fisiologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Neoplasias do Colo/patologia , Inibidores Enzimáticos/farmacologia , Humanos , Masculino , Metaloproteases/metabolismo , Camundongos , Camundongos Nus , Invasividade Neoplásica , Metástase Neoplásica , Transplante de Neoplasias , Fenótipo , Fosforilação , Tirosina/metabolismo , Veias Umbilicais/citologia , Quinases da Família src/antagonistas & inibidores
10.
J Cardiovasc Pharmacol ; 13 Suppl 4: S38-41, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2475683

RESUMO

The aim of our study was to evaluate the antihypertensive effectiveness of verapamil slow-release (SR), administered once a day. We studied 11 patients, 7 male and 4 female, with an average age of 53.6 +/- 12.86 years, who had essential hypertension. After a drug washout period of at least 15 days, placebo was administered (one tablet per day), and then patients received verapamil SR 240 mg/day at 8:00 a.m. for at least 2 weeks. At the end of the washout, placebo, and active drug treatment periods we performed ambulatory intermittent blood pressure monitoring for 24 h using a Squibb Spacelabs pressurometer. After verapamil treatment, in comparison to placebo, a significant reduction of systolic (SBP) and diastolic blood pressure (DBP) (154.91 +/- 13.34/94.29 +/- 9.48 vs. 143.73 +/- 11.39/84.6 +/- 7.99 mm Hg; p less than 0.005), was observed without significant changes of the circadian blood pressure pattern. Moreover, we observed a significant reduction of SBP and DBP variability mainly during daytime, whereas this behavior was not evident for heart rate. In conclusion, verapamil SR seems useful to obtain a constant and significant reduction of 24-h blood pressure values with a significant reduction of SBP and DBP variability.


Assuntos
Determinação da Pressão Arterial , Hipertensão/tratamento farmacológico , Monitorização Fisiológica/métodos , Verapamil/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Ritmo Circadiano , Preparações de Ação Retardada , Estudos de Avaliação como Assunto , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Verapamil/administração & dosagem , Verapamil/efeitos adversos
11.
J Cardiovasc Pharmacol ; 10 Suppl 3: S104-6, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-2446055

RESUMO

In order to assess the medium-term efficacy of ketanserin in comparison with that of the beta-blocker, propranolol, a randomized double-blind crossover trial was conducted involving 13 patients suffering from mild or moderate essential hypertension. Six of these patients were also evaluated on an ambulatory basis using noninvasive intermittent blood pressure monitoring to corroborate these values. Results indicated that both ketanserin and propranolol significantly lowered systolic, diastolic, and mean blood pressure levels after 60-day treatment periods. Diastolic blood pressure levels of less than or equal to 90 mm Hg were achieved in seven patients following ketanserin therapy and in six patients after treatment with propranolol. Both ketanserin and propranolol reduced arterial blood pressure without interfering with its circadian rhythm and variability. A tendency for the blood pressure lowering effect of ketanserin to increase with age was also noted. Side effects were minimal. The results of this trial confirm the efficacy and safety of ketanserin for the treatment of mild or moderate hypertension.


Assuntos
Hipertensão/tratamento farmacológico , Ketanserina/uso terapêutico , Propranolol/uso terapêutico , Adulto , Pressão Sanguínea/efeitos dos fármacos , Ensaios Clínicos como Assunto , Método Duplo-Cego , Feminino , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Distribuição Aleatória
12.
Cardiology ; 74 Suppl 1: 20-8, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3300974

RESUMO

We studied 14 patients, 9 males and 5 females, with an average age of 53.6 +/- 9.2 years, having been suffering from effort angina for over 6 months, with positive ergometer test for angina and ST-segment depression greater than 1 mm. All the patients performed a washout period of 7 days at the end of which, before and after acute administration (90 min) of isosorbide 5-mononitrate or placebo some echocardiographic parameters were controlled according to a double-blind, randomized, crossover design. Moreover, after 2 months of open treatment with isosorbide 5-mononitrate (20 mg three times daily), echocardiographic parameters were investigated again. Continuous ECG monitoring (24 h) was performed after the washout period and after 2 months of treatment. After acute administration of isosorbide 5-mononitrate, we observed a reduction in pre- and afterload, whereas after 2 months of treatment the reduction in preload seems to play a more important role. Together with other mechanisms these haemodynamic changes are responsible for the substantial diminution of myocardial oxygen consumption, and consequently for the reduction of transient ischaemic episodes, both symptomatic and asymptomatic with heart rate increase. These results suggest that isosorbide 5-mononitrate exhibits a definite nitrate-typical vascular activity that is evident both after single administration and after 2 months of treatment.


Assuntos
Angina Pectoris/tratamento farmacológico , Dinitrato de Isossorbida/análogos & derivados , Pressão Sanguínea , Ensaios Clínicos como Assunto , Método Duplo-Cego , Ecocardiografia , Eletrocardiografia , Feminino , Frequência Cardíaca , Humanos , Dinitrato de Isossorbida/uso terapêutico , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Esforço Físico
13.
J Cardiovasc Pharmacol ; 8 Suppl 5: S122-4, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-2427870

RESUMO

A significant reduction of maximal vasodilation capacity at the calf in relation to the severity of the hypertensive state has been demonstrated in essential hypertension. The aim of this study was to evaluate the behavior of calf blood flow and vascular resistance in borderline hypertensives (BH) in comparison with normotensive control subjects (CS). We studied 32 BH, with average age of 47.31 +/- 16.78 years and blood pressure 140-160/90-95 mm/Hg, in comparison with 20 CS, with average age of 47.24 +/- 11.75 years and blood pressure values below 140/85 mm Hg. Calf rest flow (RF) and peak flow (PF) were evaluated by strain-gauge plethysmography, and basal vascular resistance (BVR) and minimal vascular resistance (MVR) were calculated by the ratio between mean blood pressure and RF and PF, respectively. Mean blood pressure was significantly higher in BH in comparison with CS. RF and PF did not differ significantly in BH in comparison with CS. BVR did not differ in BHs in comparison with CS. In contrast, MVR were significantly higher in BH in comparison with CS. These results show that in BH, arterial flow at the calf is normal, whereas MVR are higher, indicating an impairment of maximal vasodilation capacity despite the modest blood pressure elevation.


Assuntos
Hipertensão/fisiopatologia , Perna (Membro)/irrigação sanguínea , Resistência Vascular , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional
14.
Cardiologia ; 34(9): 797-801, 1989 Sep.
Artigo em Italiano | MEDLINE | ID: mdl-2605589

RESUMO

Aim of this study was to verify the prevalence of cardiac arrhythmias in subjects with mitral valve prolapse (MVP) and redundant leaflets in comparison with subjects with MVP without leaflets redundance. So, 60 subjects (aged 13 to 39 years), were subdivided in 3 groups on the basis of mitral leaflets shape at 2D-echocardiography; a continuous ECG monitoring (24 hours) was also performed. Arrhythmias were more frequent and more severe in the Group III (subjects with MVP and redundant leaflets), in comparison with both Group II (subjects with MVP without leaflets redundance) and Group I (control subjects). In particular, analysing the mean values of the single arrhythmias in the 24 hours, ventricular ectopic beats (VEB), were more frequent in Group II (p less than 0.01) and Group III (p less than 0.05) in comparison with Group I; the couplets and the runs of ventricular tachycardia were more frequent in Group III than in the other groups (p less than 0.001). The number of the subjects with a Lown class greater than 3 was higher in Group III than in the other groups (p less than 0.01). In conclusion, this study confirms that MVP is a disease presenting a large variability arrhythmic risk, that seems to be real only for a subgroup of these subjects.


Assuntos
Arritmias Cardíacas/etiologia , Prolapso da Valva Mitral/complicações , Valva Mitral/patologia , Adolescente , Adulto , Feminino , Frequência Cardíaca , Humanos , Masculino
15.
Eur Heart J ; 9 Suppl N: 11-4, 1988 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3246242

RESUMO

The aim of our study was to evaluate the prevalence of asymptomatic episodes of ischaemia and their relation to heart rate in patients with effort angina pectoris undergoing continuous electrocardiographic monitoring for 24 h. We studied 91 patients with typical history of effort angina and positive stress testing (angina and rectilinear or downsloping ST segment depression more than 1 mm). During electrocardiographic monitoring 81 patients showed symptomatic or asymptomatic ischaemic episodes with ST segment depression, four patients a T wave inversion, while six patients did not show ischaemic episodes. The total number of ischaemic episodes registered was 284, of which 106 (37.32%) were symptomatic with significant heart rate increase, 130 (45.78%) asymptomatic with heart rate increase and 48 (16.9%) asymptomatic without heart rate changes. Twelve patients (13.18%) showed only symptomatic episodes of ischaemia with increase of heart rate, 26 patients (28.57%) symptomatic and asymptomatic episodes with heart rate enhancement, 12 patients (13.18%) only asymptomatic episodes with heart rate increase, eight patients (8.79%) symptomatic episodes of ischaemia with heart rate increase and asymptomatic ones with and without heart rate changes, and finally 23 patients (25.57%) showed symptomatic episodes with heart rate increase and asymptomatic ones without heart rate changes. In total, 31 (34.06%) of these patients showed during continuous electrocardiographic monitoring asymptomatic episodes of ischaemia without heart rate changes. These findings suggest a possible intervention of coronary tone modifications in determining asymptomatic ischaemic episodes without heart rate change in patients with effort angina.


Assuntos
Circulação Coronária , Doença das Coronárias/etiologia , Frequência Cardíaca , Isquemia/complicações , Adulto , Idoso , Angina Pectoris/complicações , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
16.
Eur Heart J ; 9 Suppl N: 164-8, 1988 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3246249

RESUMO

Continuous ECG monitoring is a useful method to evaluate the efficacy of antiarrhythmic drugs. The aim of our study was to evaluate the effects of amiodarone (400 mg day-1 for seven days and then 200 mg day-1, five days a week, for 60 days) in 20 patients with chronic ischaemic heart disease ascertained by stress test, thallium-201 myocardial scintigraphy and coronary angiography and with qualitatively and quantitatively similar cardiac arrhythmias in two continuous ECG monitoring sessions performed before starting treatment. All patients were previously on treatment with isosorbide 5-mononitrate (Is-5-Mn). Patients underwent two ECG monitoring sessions for 48 h, with an ICR instrument with two leads, first during pharmacological treatment with Is-5-Mn plus placebo and then after 60 days on treatment with Is-5-Mn and amiodarone. Heart rate decreased significantly with amiodarone (from 76.9 to 69.5 beats min-1) as did premature ventricular complexes (from 4686 to 329 day-1), ventricular couplets (from 154.3 to 5.0 day-1), ventricular tachycardia runs (from 91.7 to 0). ST segment depression more than 1.5 mm was present for 93.8 min day-1 on Is-5-Mn plus placebo, and was significantly less frequently observed (for 13.8 min day-1) on Is-5-Mn plus amiodarone. Finally, transient episodes of ischaemia, both symptomatic and asymptomatic, diminished on amiodarone from 22 to 9 day-1 in a significant way. In conclusion, amiodarone is a useful drug to obtain a reduction of ventricular arrhythmias and symptomatic and asymptomatic episodes of ischaemia in patients with ischaemic heart disease.


Assuntos
Amiodarona/uso terapêutico , Arritmias Cardíacas/complicações , Doença das Coronárias/complicações , Idoso , Angiocardiografia , Arritmias Cardíacas/tratamento farmacológico , Doença das Coronárias/tratamento farmacológico , Relação Dose-Resposta a Droga , Eletrocardiografia , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
17.
Eur J Clin Pharmacol ; 39 Suppl 1: S49-51, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2148153

RESUMO

To evaluate the relationship among supraventricular and ventricular arrhythmias with blood pressure and heart rate (HR) values, we studied 2 groups of 20 hypertensive men with (group I) and without (group II) left ventricular hypertrophy. Ambulatory electrocardiographic tracings were recorded continuously, together with ambulatory arterial pressure. Systolic (SBP) and diastolic (DBP) blood pressure values measured over 24 h showed no difference between the two groups, but we found greater variability in SBP in group I. The incidence of ventricular and supraventricular arrhythmias was significantly higher in patients of group I; moreover, we found a strong correlation between the incidence of ventricular extrasystoles (VPCs) and SBP, DBP, and HR values in group I, whereas in group II the incidence of supraventricular extrasystoles (APCs) was higher during peaks of SBP and HR values. The relationship between APCs and SBP observed in group II may be attributable to the pressure stimulus on a normal atrium, and the significant correlation between VPCs and SBP, DBP, and HR values may be due to episodes of subendocardial ischemia or to the influence of adrenergic stimulation on previously compromised myocardial tissue.


Assuntos
Arritmias Cardíacas/fisiopatologia , Pressão Sanguínea/fisiologia , Cardiomegalia/fisiopatologia , Ritmo Circadiano/fisiologia , Frequência Cardíaca/fisiologia , Ventrículos do Coração/fisiopatologia , Humanos , Hipertensão/complicações , Masculino , Sístole , Função Ventricular Esquerda/fisiologia
18.
Biochem Biophys Res Commun ; 301(4): 907-14, 2003 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-12589798

RESUMO

The adhesion of cancer cells to the endothelium during the metastatic process involves the interaction of specific cell-cell adhesion receptors on the cell surface. E-selectin on endothelial cells and sialyl Lewis X carbohydrate component on tumor cells are mainly implicated in the adhesion of colon carcinoma cells to the endothelium of target organ. In this paper we show that binding of E-selectin to T84 colon tumor cells causes approximately a twofold increase in intracellular calcium concentration. In particular, using two inhibitors of receptor operated calcium channels, CAI and SK&F 96365, we present evidences that the augmentation in cytoplasmic calcium originates from ionic influx from extracellular sources. Furthermore, we demonstrated that modulation of [Ca2+]i by engagement of E-selectin receptor starts signal transduction pathways that affect cell spreading, tyrosine phosphorylation signaling, and cancer cell motility.


Assuntos
Cálcio/metabolismo , Neoplasias do Colo/metabolismo , Selectina E/farmacologia , Antineoplásicos/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Humanos , Imidazóis/farmacologia , Fenótipo , Fosforilação , Proteínas Recombinantes/farmacologia , Triazóis/farmacologia , Células Tumorais Cultivadas , Tirosina/metabolismo
19.
Biochem Biophys Res Commun ; 316(2): 446-53, 2004 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-15020238

RESUMO

Expression of Talpha2 gene, during sea urchin Paracentrotus lividus development, is spatially and temporally regulated. In order to characterize this gene, we isolated the relevant genomic sequences and scanned the isolated 5'-flanking region in searching for cis-regulatory elements required for proper expression. Gel mobility shift and footprinting assays, as well as reporter gene (CAT and beta-gal) expression assays, were used to address cis-regulatory elements involved in regulation. Here we report that an upstream 5'-flanking fragment of PlTalpha2 gene drives temporal expression of reporter genes congruent with that of endogenous Talpha2 gene. The fragment contains cis-elements able to bind nuclear proteins from the gastrula stage (at which the Talpha2 gene is expressed) whose sequences could be consistent with the consensus sequences for transcription factors present in data bank.


Assuntos
Regiões Promotoras Genéticas , Ouriços-do-Mar/genética , Tubulina (Proteína)/genética , Animais , Sequência de Bases , Clonagem Molecular , Componentes do Gene , Genes , Dados de Sequência Molecular , Neurônios/química , Ouriços-do-Mar/embriologia , Ouriços-do-Mar/metabolismo , Sítio de Iniciação de Transcrição , Ativação Transcricional
20.
Cardiologia ; 35(8): 657-64, 1990 Aug.
Artigo em Italiano | MEDLINE | ID: mdl-2150345

RESUMO

To evaluate possible correlations between cardiac arrhythmias and circadian pattern of blood pressure (BP) and of heart rate (HR), we studied 2 groups of 20 males with stable arterial hypertension of mild to moderate entity, with (Group I) or without (Group II) left ventricular hypertrophy (LVH). In patients with LVH the mean age (56 vs 46 years), the duration of the hypertensive state (48.1 vs 15.7 months), the thickening of interventricular septum (IVS; 13.7 vs 9.6 mm) and of the posterior wall of the left ventricle (13.2 vs 9.2 mm) and the mass of LV (149.8 vs 99.7 g/m2) were significantly greater (p less than 0.01). On the contrary, the 2 groups did not show significant differences concerning casual BP determined in the morning (178.3/108.4 vs 171.5/106.2 mmHg). After a pharmacological washout of 2 weeks, patients underwent a noninvasive, intermittent, monitoring of BP (every 15 min during daytime and every 30 min from 11 pm to 7 am), using a pressure meter II Del Mar Avionics, and a continuous monitoring of ECG for 24 hours, employing an instrument 445/B Del Mar Avionics. Mean 24-hour BP was not different in the 2 groups of patients (161.7/99.0 vs 158.2/98.3 mmHg); however, patients with LVH showed a significantly greater variability of BP in the morning (7 am-3 pm), while mean 24-hour HR was significantly less (71.6 vs 78.2 b/min).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Arritmias Cardíacas/fisiopatologia , Pressão Sanguínea/fisiologia , Cardiomegalia/fisiopatologia , Ritmo Circadiano/fisiologia , Hipertensão/fisiopatologia , Adulto , Idoso , Eletrocardiografia , Humanos , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa