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1.
Eur J Nucl Med Mol Imaging ; 46(10): 2090-2098, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31264171

RESUMO

PURPOSE: The rate of clinical progression of cognitive impairment in subjects with early amyloid deposition is unknown. The primary aim of the study was to follow the rate of cognitive decline over 1 year in patients with amnestic mild cognitive impairment (aMCI) by determining amyloid retention levels in terms of standardized uptake value ratios (SUVr) that ranged from 0.85 to 1.57. The secondary objective was to compare the rate of cognitive decline between subjects with and without early amyloid positivity. METHODS: Of 66 aMCI subjects evaluated with [18F]florbetaben PET imaging and neuropsychological tests at baseline, 41 completed the 1-year follow-up. Amyloid status was determined with SUVr cut-off values generated from baseline images by visual assessment by three independent certified readers. Repeated-measures ANOVA with amyloid load and neuropsychological scores as the main effects was use to test group, time and group-by-time interactions. The Tukey post-hoc test was used to analyse all significant interactions. RESULTS: Of the 41 aMCI subjects, 38 completed the assessment according to the study protocol. Amyloid-positive (Aß+ ) subjects (N = 18, age 75.6 ± 5.8 years, six men, 12 women) showed greater clinical deterioration according to the Mattis Dementia Rating Scale (MDRS) score (p = 0.006). Amyloid-negative (Aß-) subjects (N = 20, age 72.4 ± 5.8 years, 11 men, 6 women) showed no significant changes in MDRS score over 1 year. MDRS score significantly decreased (MDRS+) in 37% of the aMCI subjects, and remained stable (MDRS-) in the remaining 63%. Among subjects with cognitive deterioration, 86% were Aß+ and 14% were Aß-, while 25% of the MDRS- subjects were Aß+ and 75% were Aß- (χ2 = 13, P = 0.0003). SUVr above 1.21 identified individuals who would show significant progression over 1 year, with a sensitivity of 67% and a specificity of 90%, as compared to Aß- subjects. The positive predictive value, negative predictive value, and likelihood ratio were 86% (95% CI 70-94%), 75% (95% CI 58-87%), 7 (95% CI 5-10). CONCLUSION: This study demonstrated that early amyloid deposition predicts cognitive decline in subjects with aMCI, with a higher rate of decline in those with SUVr above a threshold of 1.21. Detection of early amyloid positivity may help in selecting the target population for preventive therapeutic interventions and in designing treatment trials (Trial number, EudraCT 2015-001184-39).


Assuntos
Amiloide/metabolismo , Disfunção Cognitiva/diagnóstico por imagem , Neocórtex/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Idoso , Idoso de 80 Anos ou mais , Compostos de Anilina , Disfunção Cognitiva/patologia , Diagnóstico Precoce , Feminino , Humanos , Masculino , Testes de Estado Mental e Demência , Pessoa de Meia-Idade , Neocórtex/patologia , Compostos Radiofarmacêuticos , Estilbenos
2.
Funct Neurol ; 32(1): 28-34, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28380321

RESUMO

The aim of our study was to identify and quantify spatiotemporal and kinematic gait parameters obtained by 3D gait analysis (GA) in a group of Parkinson's disease (PD) patients compared with healthy subjects in order to investigate whether early PD patients could present an abnormal gait pattern. Forty-four patients affected by early-stage PD compared with a control group were analyzed. All participants were evaluated with 3D GA in the gait laboratory. The greatest significance in temporal parameters was found in cadence (102.46 ± 13.17 steps/min in parkinsonian patients vs 113.84 ± 4.30 steps/min in control subjects), followed by stride duration (1.19 ± 0.18 seconds right limb and 1.19 ± 0.19 seconds left limb in PD patients vs 0.426 ± 0.16 seconds right limb and 0.429 ± 0.23 seconds left limb in normal subjects) and stance duration. Marked differences were also found in the swing phase and in swing duration (p<0.05), while the stance phase was not significantly different in patients compared with healthy subjects. A statistically different velocity in PD patients (0.082 ± 0.29 m/s) vs healthy subjects (1.33 ± 0.06 m/s) was shown by spatial parameter analysis. Step width, stride length and swing velocity were highly significant parameters, as was average velocity. Our study highlighted some distinguishing characteristics of gait in early PD. Ambulation disorders may be present in the early stage of PD and their detection allows for early medical treatment and possible rehabilitation.


Assuntos
Marcha , Doença de Parkinson/fisiopatologia , Idoso , Antiparkinsonianos/uso terapêutico , Fenômenos Biomecânicos , Feminino , Humanos , Imageamento Tridimensional , Levodopa/uso terapêutico , Extremidade Inferior , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/tratamento farmacológico , Caminhada
5.
Parkinsonism Relat Disord ; 18(6): 770-4, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22591577

RESUMO

BACKGROUND: Despite its large clinical application, our understanding about the mechanisms of action of deep brain stimulation of the subthalamic nucleus is still limited. Aim of the present study was to explore cortical and subcortical metabolic modulations measured by Positron Emission Tomography associated with improved motor manifestations after deep brain stimulation in Parkinson disease, comparing the ON and OFF conditions. PATIENTS AND METHODS: Investigations were performed in the stimulator off- and on-conditions in 14 parkinsonian patients and results were compared with a group of matched healthy controls. The results were also used to correlate metabolic changes with the clinical effectiveness of the procedure. RESULTS: The comparisons using Statistical parametric mapping revealed a brain metabolic pattern typical of advanced Parkinson disease. The direct comparison in ON vs OFF condition showed mainly an increased metabolism in subthalamic regions, corresponding to the deep brain stimulation site. A positive correlation exists between neurostimulation clinical effectiveness and metabolic differences in ON and OFF state, including the primary sensorimotor, premotor and parietal cortices, anterior cingulate cortex. CONCLUSION: Deep brain stimulation seems to operate modulating the neuronal network rather than merely exciting or inhibiting basal ganglia nuclei. Correlations with Parkinson Disease cardinal features suggest that the improvement of specific motor signs associated with deep brain stimulation might be explained by the functional modulation, not only in the target region, but also in surrounding and remote connecting areas, resulting in clinically beneficial effects.


Assuntos
Encéfalo/metabolismo , Estimulação Encefálica Profunda , Glucose/metabolismo , Doença de Parkinson/terapia , Núcleo Subtalâmico/metabolismo , Idoso , Encéfalo/diagnóstico por imagem , Estudos de Casos e Controles , Feminino , Fluordesoxiglucose F18 , Lobo Frontal/diagnóstico por imagem , Lobo Frontal/metabolismo , Giro do Cíngulo/diagnóstico por imagem , Giro do Cíngulo/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Lobo Parietal/diagnóstico por imagem , Lobo Parietal/metabolismo , Doença de Parkinson/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Núcleo Subtalâmico/diagnóstico por imagem
6.
Endoscopy ; 39(9): 813-7, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17703391

RESUMO

BACKGROUND AND STUDY AIMS: Biliary stents have been found to interfere with endoscopic ultrasound (EUS) tumor (T) and nodal (N) staging in patients with periampullary cancer. Our aim was to determine whether this also occurs in patients with pancreatic head cancer. PATIENTS AND METHODS: We studied a consecutive series of patients who were undergoing preoperative EUS for diagnosis and staging of suspected pancreatic cancer, some of whom had biliary stents in situ and some of whom did not. The main end point was the uni- and multivariate association of biliary stenting with T and N mis-staging by EUS. The surgical T and N stages were used as gold standards. RESULTS: A total of 65 patients were identified (19 with biliary stents in situ and 46 without). Surgical stage T4 was found more frequently in patients with stents (53% vs. 22%, P = 0.014). The T stage by EUS was correct in 85% of the patients without biliary stents and in 47% of the patients with stents. The frequency of mis-staging by EUS was significant only among patients with a biliary stent. The distribution by EUS N stage did not differ significantly from the surgical N-stage distribution in the two groups of patients. According to the multivariate analysis, patients with stents were 6.55 times more likely to be incorrectly T staged (95% confidence interval [CI] 1.69-25.49) and 3.71 times more likely to be incorrectly N staged (95% CI 1.11-12.45) than patients without stents. CONCLUSIONS: The results add support to the recommendation that EUS staging of pancreatic head neoplasms should be performed prior to stent placement.


Assuntos
Ductos Biliares , Endossonografia , Neoplasias Pancreáticas/diagnóstico por imagem , Stents/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Pancreáticas/patologia , Reprodutibilidade dos Testes
8.
J Telemed Telecare ; 11 Suppl 1: 93-4, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16036010

RESUMO

We compared two models of assistance (telecardiology versus usual care) for patients discharged after acute coronary syndrome (ACS), in the assessment of angina. Two hundred patients were randomized into two groups at discharge for ACS: Group A to telecardiology and Group B to usual care. Early hospital readmission (in the first month) occurred in 16 patients (seven in Group A and nine in Group B). Six of Group A were readmitted for a cardiac cause (non-cardiac in one). Angina was the only cardiac cause. Five of the Group B patients were readmitted for a cardiac cause (non-cardiac in four). The results of the present study emphasize that patients with ACS suffer from a definite rate of cardiac symptoms within the first month (63%). Angina occurs more frequently within the first two weeks (68% of cases). Telecardiology slightly reduces hospital readmissions (telecardiology 44% versus usual care 56%), but better identifies true angina.


Assuntos
Angina Instável/diagnóstico , Infarto do Miocárdio/fisiopatologia , Telemedicina/métodos , Angina Instável/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Infarto do Miocárdio/terapia , Readmissão do Paciente , Estudos Prospectivos , Síndrome
9.
Clin Ter ; 154(3): 199-206, 2003.
Artigo em Italiano | MEDLINE | ID: mdl-12910810

RESUMO

PURPOSE: Most patients with heart failure are elderly with multiple coexisting diseases and heart failure is the most common discharge diagnosis in elderly hospitalized patients. Despite major advances in the pharmacotherapy of heart failure, hospitalization rates remain high, owing in large part to a multitude of psychosocial, behavioral, and financial factors that serve as barriers to effective compliance with prescribed treatment. In the last decade, several models have been proposed in order to optimise the long-term management of elderly patients with heart failure. DESIGN: A review of most significant and recent models available was performed. RESULTS: Several studies have documented the efficacy of specialized multidisciplinary heart failure disease management programs in terms of reducing hospital utilization, improving quality of life, functional capacity, patient satisfaction, compliance with diet and medications and decreasing cost of care. CONCLUSIONS: At present, the greatest challenge in managing elderly heart failure patients is to more effectively implement proven treatments and disease management systems.


Assuntos
Gerenciamento Clínico , Insuficiência Cardíaca/terapia , Fatores Etários , Idoso , Doença Crônica , Ensaios Clínicos como Assunto , Seguimentos , Idoso Fragilizado , Insuficiência Cardíaca/economia , Insuficiência Cardíaca/enfermagem , Serviços de Assistência Domiciliar , Hospitalização , Humanos , Tempo de Internação , Assistência de Longa Duração , Cooperação do Paciente , Educação de Pacientes como Assunto , Satisfação do Paciente , Guias de Prática Clínica como Assunto , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Inquéritos e Questionários , Fatores de Tempo
10.
J Am Coll Cardiol ; 38(7): 1829-35, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11738281

RESUMO

OBJECTIVES: This study investigated the prognostic value of left ventricular (LV) mass at echocardiography in uncomplicated subjects with essential hypertension. BACKGROUND: Only a few single-center studies support the prognostic value of LV mass in uncomplicated hypertension. METHODS: The MAssa Ventricolare sinistra nell'Ipertensione study was a multicenter (45 centers) prospective study. The prespecified aim was to explore the prognostic value of LV mass in hypertension. Admission criteria included essential hypertension, no previous cardiovascular events, and age > or =50. There was central reading of echocardiographic tracings. Treatment was tailored to the single subject. RESULTS: Overall, 1,033 subjects (396 men) were followed for 0 to 4 years (median, 3 years). Mean age at entry was 60 years, and systolic/diastolic blood pressure was 154/92 mm Hg. The rate of cardiovascular events (x100 patient-years) was 1.3 in the group with normal LV mass and 3.2 in the group (28.5% of total sample) with LV mass > or =125 g/body surface area (p = 0.005). After adjustment for age (p < 0.01), diabetes (p < 0.01), cigarette smoking (p < 0.01) and serum creatinine (p = 0.03), LV hypertrophy was associated with an increased risk of events (RR [relative risk] 2.08; 95% CI [confidence interval]: 1.22 to 3.57). For each 39 g/m(2) (1 SD) increase in LV mass there was an independent 40% rise in the risk of major cardiovascular events (95% CI: 14 to 72; p = 0.0013). CONCLUSIONS: Our findings show a strong, continuous and independent relationship of LV mass to subsequent cardiovascular morbidity. This is the first study to extend such demonstration to a large nationwide multicenter sample of uncomplicated subjects with essential hypertension.


Assuntos
Doenças Cardiovasculares/diagnóstico por imagem , Ecoencefalografia , Hipertensão/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Idoso , Doenças Cardiovasculares/mortalidade , Causas de Morte , Morte Súbita Cardíaca/epidemiologia , Morte Súbita Cardíaca/etiologia , Feminino , Humanos , Hipertrofia Ventricular Esquerda/mortalidade , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/mortalidade , Prognóstico , Estudos Prospectivos , Fatores de Risco
11.
Breast Cancer Res Treat ; 66(1): 67-72, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11368412

RESUMO

The present work aimed to study the activities of glyoxalase system enzymes, glyoxalase I (G I) and glyoxalase II (G II), as well as the expression of their genes in human breast carcinoma. Samples of tumoral tissue and normal counterparts were drawn from several patients during surgery. They served either for preparing extracts to be used in enzyme activity evaluations or for RNA extraction and subsequent northern blot analysis. A far higher activity level of G I and G II occurs in the tumor compared with pair-matched normal tissue, as shown by both spectrophotometrical assay and electrophoretic pattern. Such increased activities of G I and G II likely result from an enhanced enzyme synthesis as a consequence of increased expression of the respective genes in the tumoral tissue, as evidenced by northern blot. The present findings confirm a key-role of glyoxalase system to detoxify cytotoxic methylglyoxal and modulate S-D-lactoylglutathione levels in tumor cells. Moreover, they suggest a possible employment of GI inhibitors as anti-cancer drugs.


Assuntos
Neoplasias da Mama/metabolismo , Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Lactoilglutationa Liase/metabolismo , Tioléster Hidrolases/metabolismo , Adulto , Idoso , Northern Blotting , Estudos de Casos e Controles , Eletroforese em Gel de Poliacrilamida , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Lactoilglutationa Liase/genética , Pessoa de Meia-Idade , RNA Neoplásico , Tioléster Hidrolases/genética
12.
Ital Heart J Suppl ; 2(3): 235-52, 2001 Mar.
Artigo em Italiano | MEDLINE | ID: mdl-11307782

RESUMO

Cardiac arrest is one of the leading causes of mortality in industrialized countries and is mainly due to ischemic heart disease. According to ISTAT estimates, approximately 45,000 sudden deaths occur annually in Italy whereas according to the World Health Organization, its incidence is 1 per 1000 persons. The most common cause of cardiac arrest is ventricular fibrillation due to an acute ischemic episode. During acute ischemia the onset of a ventricular tachyarrhythmia is sudden, unpredictable and often irreversible and lethal. Each minute that passes, the probability that the patient survives decreases by 10%. For this reason, the first 10 min are considered to be priceless for an efficacious first aid. The possibility of survival depends on the presence of witnesses, on the heart rhythm and on the resolution of the arrhythmia. In the majority of cases, the latter is possible by means of electrical defibrillation followed by the reestablishment of systolic function. An increase in equipment alone does not suffice for efficacious handling of cardiac arrest occurring outside the hospital premises. Above all, an adequate intervention strategy is required. Ambulance personnel must be well trained and capable of intervening rapidly, possibly within the first 5 min. The key to success lies in the diffusion and proper use of defibrillators. The availability of new generation instruments, the external automatic defibrillators, encourages their widespread use. On the territory, these emergencies are the responsibility of the 118 organization based, according to the characteristics specific to each country, on the regulated coordination between the operative command, the crews and the first-aid means. Strategies for the handling of these emergencies within hospitals have been proposed by the Conference of Bethesda and tend to guarantee an efficacious resuscitation with a maximum latency of 2 min between cardiac arrest and the first electric shock. The diffusion of external automatic defibrillators is a preventive measure. Such equipment has permitted early defibrillation by non-medical first-aid personnel. These instruments contain software capable of recognizing an arrhythmia which may be defibrillated and of instructing the operator whether and when to press the defibrillation button. The latest instruments deliver the shock by means of a biphasic wave necessitating a lesser amount of energy which can be provided by lighter condensers. Thus such equipment weighs just a couple of kilograms. As suggested by ILCOR, for reasons of priority, such instruments should not only be available within hospitals and in ambulances but also on the territory, in particular in more crowded places. The availability of external automatic defibrillators in such places should reduce the time latency before intervention and thus increase survival. The ILCOR guidelines have suggested the constitution of an itinerary team well equipped for defibrillation and composed of trained personnel of State Institutions such as the Municipal Police, Traffic Police and the Fire Brigades. With regard to the majority of arrhythmias amenable to defibrillation which occur at home or in less crowded places, other strategies, such as primary prevention and training programs for categories at increased risk, must be employed. Antiarrhythmic drugs have long been considered the best solution for the prevention and treatment of ventricular tachyarrhythmias. However, the approach to these pathologies has drastically changed during the last few years owing to accumulating evidence in favor of defibrillators which may be implanted for the primary and secondary prevention of malignant ventricular arrhythmias. For patients with previous cardiac arrest, randomized studies have proven the advantages of such an approach compared to medical therapy. On the basis of the above, the guidelines for the use of antiarrhythmic implants have been modified. In most western countries, the laws regarding this aspect of medicine have recently been renewed. In the United States, where there is the "Law of the Good Samaritan", in order to protect and acquit persons who give first-aid, many states have adopted new laws which promote the use of external automatic defibrillators. Following recent dispositions by the President of the United States that defibrillators should be present in all Federal properties and on civil aircraft, a new Federal Law is about to pass. Italy lacks legislation regarding the use of defibrillators: in order to rectify this position, which is still anchored to existing dispositions of the civil and penal codes including those regarding the omission of first-aid, a bill entitled "The definition and modalities of the use of the external cardiac defibrillator" has recently been presented.


Assuntos
Parada Cardíaca , Análise Custo-Benefício , Desfibriladores Implantáveis/economia , Europa (Continente) , Parada Cardíaca/diagnóstico , Parada Cardíaca/epidemiologia , Parada Cardíaca/terapia , Hospitalização , Humanos , Itália , Prevenção Primária , Fatores de Risco
13.
Chem Biol Interact ; 134(2): 151-66, 2001 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-11311211

RESUMO

Three forms of acetylcholinesterase (AChE) were detected in samples of the bivalve mollusc Mytilus galloprovincialis collected in sites of the Adriatic sea. Apart from the origin of the mussels, two spontaneously soluble (SS) AChE occur in the hemolymph and represent about 80% of total activity, perhaps hydrolyzing metabolism-borne choline esters. These hydrophilic enzymes (forms A and B) copurified by affinity chromatography (procainamide-Sepharose gel) and were separated by sucrose gradient centrifugation. They are, respectively, a globular tetramer (11.0-12.0 S) and a dimer (6.0-7.0 S) of catalytic subunits. The third form, also purified from tissue extracts by the same affinity matrix, proved to be an amphiphilic globular dimer (7.0 S) with a phosphatidylinositol tail giving cell membrane insertion, detergent (Triton X-100, Brij 96) interaction and self-aggregation. Such an AChE is likely functional in cholinergic synapses. All three AChE forms show a good substrate specificity and are inactive on butyrylthiocholine. Studies with inhibitors showed low inhibition by eserine and paraoxon, especially on SS forms, high sensitivity to 1,5-bis(4-allyldimethylammoniumphenyl)-pentan-3-one dibromide (BW284c51) and no inhibition with propoxur and diisopropylfluorophosphate (DFP). The ChE forms in M. galloprovincialis are possibly encoded by different genes. Some kinetic features of these enzymes suggest a genetic polymorphism.


Assuntos
Acetilcolinesterase/isolamento & purificação , Bivalves/enzimologia , Acetilcolinesterase/química , Acetilcolinesterase/genética , Acetilcolinesterase/metabolismo , Animais , Bivalves/genética , Centrifugação com Gradiente de Concentração , Inibidores da Colinesterase/farmacologia , Cromatografia de Afinidade , Membranas/enzimologia , Paraoxon/farmacologia , Fisostigmina/farmacologia , Polimorfismo Genético , Solubilidade
15.
Cardiologia ; 44(3): 299-312, 1999 Mar.
Artigo em Italiano | MEDLINE | ID: mdl-10327733
17.
J Neurochem ; 72(3): 1250-8, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10037498

RESUMO

Acetylcholinesterase cDNA was cloned by screening a library from Loligo opalescens optic lobes; cDNA sequence analysis revealed an open reading frame coding for a protein of 610 amino acids that showed 20-41% amino acid identity with the acetylcholinesterases studied so far. The characteristic structure of cholinesterase (the choline binding site, the catalytic triad, and six cysteines that form three intrachain disulfide bonds) was conserved in the protein. The heterologous expression of acetylcholinesterase in COS cells gave a recovery of acetylcholinesterase activity 20-fold higher than in controls. The enzyme, partially purified by affinity chromatography, showed molecular and kinetic features indistinguishable from those of acetylcholinesterase expressed in vivo, which displays a high catalytic efficiency. Both enzymes are true acetylcholinesterase corresponding to phosphatidylinositol-anchored G2a dimers of class I, with a marked substrate specificity for acetylthiocholine. The deduced amino acid sequence may explain some particular kinetic characteristics of Loligo acetylcholinesterase, because the presence of a polar amino acid residue (S313) instead of a nonpolar one [F(288) in Torpedo] in the acyl pocket of the active site could justify the high substrate specificity of the enzyme, the absence of hydrolysis with butyrylthiocholine, and the poor inhibition by the organophosphate diisopropyl fluorophosphate.


Assuntos
Acetilcolinesterase/biossíntese , Encéfalo/efeitos dos fármacos , Inibidores da Colinesterase/farmacologia , DNA Complementar/biossíntese , Decapodiformes/metabolismo , Isoflurofato/farmacologia , Acetilcolinesterase/genética , Acetilcolinesterase/isolamento & purificação , Sequência de Aminoácidos , Animais , Sequência de Bases , Encéfalo/enzimologia , Células COS , Centrifugação com Gradiente de Concentração , Clonagem Molecular , DNA Complementar/genética , Resistência a Medicamentos , Eletroforese em Gel de Poliacrilamida , Cinética , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Fosfolipases Tipo C/química
18.
Clin Ter ; 149(4): 297-305, 1998.
Artigo em Italiano | MEDLINE | ID: mdl-9866892

RESUMO

PURPOSE: To evaluate efficacy and indications of therapy for ventricular arrhythmias in patients with chronic congestive heart failure. DESIGN: A review of most significant and recent clinical trials was performed. RESULTS: In patients with severe left ventricular dysfunction, the desirable actions of antiarrhythmic drugs are attenuated and their negative inotropic and proarrhythmic actions are enhanced. Treatment should be limited to patients with malignant ventricular arrhythmias, or to patients considered at high risk. When indicated, amiodarone is usually well tolerated and safe. The prevention of sudden death in patients with heart failure should be based on optimized therapy of pump failure, reducing left ventricle work load and modulating neurohormonal systems with ACE-inhibitors and betablockers drugs. Further, an important role is held by anti-ischemic therapy, revascularization procedures, anticoagulant therapy and prevention of electrolytes unbalances. Patients with sustained of high risk arrhythmias, resuscitated from a cardiac arrest, should be considered for transvenous Implantable Cardioverter Defibrillator (ICD) implant. CONCLUSIONS: Ventricular arrhythmias are common in heart failure patients, represent an important cause of sudden death and the choice of treatment is difficult because of the complexity of underlying mechanisms, frequency of adverse reactions and the severity of left ventricular dysfunction.


Assuntos
Insuficiência Cardíaca/terapia , Disfunção Ventricular Esquerda/etiologia , Antiarrítmicos/uso terapêutico , Arritmias Cardíacas , Doença Crônica , Morte Súbita/prevenção & controle , Desfibriladores Implantáveis , Cardioversão Elétrica , Insuficiência Cardíaca/complicações , Humanos , Disfunção Ventricular Esquerda/terapia
19.
Neurochem Int ; 33(2): 131-41, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9761457

RESUMO

In the optic lobe of the cephalopod mollusc Eledone moschata, two acetylcholinesterase forms I and II were detected, both showing a marked active site specificity with differently sized substrates. Catalytic efficiency (kcat/Km) of the prevailing form II is similar to that of acetylcholinesterases from vertebrate nervous system. Enzyme forms I and II were co-purified from a high-salt-Triton X-100 soluble extract of optic lobe by consecutive affinity chromatographies on procainamide- and concanavalin A-Sepharose columns and then separately obtained by preparative density gradient centrifugation. According to gel-filtration chromatography, sedimentation analysis and SDS-PAGE, the major form II is an amphiphilic globular dimer (135-136 kDa, 6.3-7.4 S) of monomers (66 kDa) S-S linked between terminal segments. Phosphatidylinositol anchors give cell membrane insertion, self-aggregation and detergent (Triton X-100, Brij 97) interaction. Form I, characterized only in part owing to its small amount, showed molecular size (129 kDa) and sedimentation coefficient (7.5 S) similar to those of form II; it is likely to be attached to the cell membrane by electrostatic interactions. Both forms behaved similarly with various inhibitors and underwent excess-substrate inhibition. The results obtained suggest a common origin of both form I and II from a single gene. The former could be a degradation product of the prevailing one (II), which is likely to be functional in cholinergic synapses.


Assuntos
Acetilcolinesterase/metabolismo , Isoenzimas/metabolismo , Moluscos/enzimologia , Lobo Óptico de Animais não Mamíferos/enzimologia , Acetilcolinesterase/química , Acetilcolinesterase/isolamento & purificação , Animais , Catálise , Centrifugação com Gradiente de Concentração , Dissulfetos/química , Histocitoquímica , Isoenzimas/química , Isoenzimas/isolamento & purificação , Cinética , Estrutura Molecular , Peso Molecular , Especificidade por Substrato , Fosfolipases Tipo C/farmacologia
20.
Cardiovasc Drugs Ther ; 12(5): 431-7, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9926273

RESUMO

The influence of the calcium antagonist gallopamil on the contractility of asynergic viable myocardium after acute myocardial infarction treated with thrombolysis was investigated by two-dimensional echocardiography. Sixteen patients with > or = 1 viable segment(s), identified during the low-dose phase (up to 10 micrograms/kg/min) of a dobutamine echocardiographic test (up to 40 micrograms/kg/min) performed 4-5 days after a first acute myocardial infarction, were given a gallopamil intravenous bolus (50 micrograms/kg) 12-24 hours later. Two-dimensional echocardiography was done before and 15 minutes after the bolus. A score index of 1 (normokinesis) to 4 (dyskinesis) and a 16-segment model were used. A segment was considered viable when a resting asynergy (score > or = 2) improvement of > or = 1 grade was seen during low-dose dobutamine. Follow-up echocardiograms were done 3-5 months later. A total of 30 viable segments were found; of these, 10 showed sustained improvement in contractility (group A) during high-dose dobutamine, while 20 exhibited a biphasic response returning to their basal contractile state (group B). After the gallopamil bolus, 9 of 10 group A segments improved their contractility, in comparison with 0 of 20 group B segments (P < .001). Infarct-related vessel significant (> or = 75%) coronary stenosis was present in the tributary vessel of 0 of 10 group A and of 20 of 20 group B segments (P < .001). At follow-up, 9 of 10 group A segments showed a spontaneous contractile improvement; of the 20 group B segments, 8 of 10 that underwent revascularization (7 angioplasty, 3 bypass graft) showed contractile improvement, in comparison with 0 of 10 segments not revascularized (P = .001). We conclude that gallopamil may reverse the contractile dysfunction of postischemic stunned myocardium in patients with acute myocardial infarction, whereas no effects are apparent on ischemic/hibernating myocardium.


Assuntos
Bloqueadores dos Canais de Cálcio/uso terapêutico , Galopamil/uso terapêutico , Coração/efeitos dos fármacos , Hibernação , Contração Miocárdica/efeitos dos fármacos , Miocárdio Atordoado , Dobutamina/uso terapêutico , Relação Dose-Resposta a Droga , Ecocardiografia , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Terapia Trombolítica
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