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1.
Nat Commun ; 9(1): 4437, 2018 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-30361627

RESUMO

Focal electrical stimulation of the brain incites a cascade of neural activity that propagates from the stimulated region to both nearby and remote areas, offering the potential to control the activity of brain networks. Understanding how exogenous electrical signals perturb such networks in humans is key to its clinical translation. To investigate this, we applied electrical stimulation to subregions of the medial temporal lobe in 26 neurosurgical patients fitted with indwelling electrodes. Networks of low-frequency (5-13 Hz) spectral coherence predicted stimulation-evoked increases in theta (5-8 Hz) power, particularly when stimulation was applied in or adjacent to white matter. Stimulation tended to decrease power in the high-frequency broadband (HFB; 50-200 Hz) range, and these modulations were correlated with HFB-based networks in a subset of subjects. Our results demonstrate that functional connectivity is predictive of causal changes in the brain, capturing evoked activity across brain regions and frequency bands.


Assuntos
Rede Nervosa/fisiologia , Lobo Temporal/fisiologia , Ritmo Teta/fisiologia , Estimulação Elétrica , Potenciais Evocados/fisiologia , Humanos , Substância Branca/fisiologia
2.
Nat Commun ; 8(1): 1704, 2017 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-29167419

RESUMO

The idea that synchronous neural activity underlies cognition has driven an extensive body of research in human and animal neuroscience. Yet, insufficient data on intracranial electrical connectivity has precluded a direct test of this hypothesis in a whole-brain setting. Through the lens of memory encoding and retrieval processes, we construct whole-brain connectivity maps of fast gamma (30-100 Hz) and slow theta (3-8 Hz) spectral neural activity, based on data from 294 neurosurgical patients fitted with indwelling electrodes. Here we report that gamma networks desynchronize and theta networks synchronize during encoding and retrieval. Furthermore, for nearly all brain regions we studied, gamma power rises as that region desynchronizes with gamma activity elsewhere in the brain, establishing gamma as a largely asynchronous phenomenon. The abundant phenomenon of theta synchrony is positively correlated with a brain region's gamma power, suggesting a predominant low-frequency mechanism for inter-regional communication.


Assuntos
Cognição/fisiologia , Sincronização de Fases em Eletroencefalografia/fisiologia , Ritmo Teta/fisiologia , Animais , Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Conectoma , Ritmo Gama/fisiologia , Humanos , Memória/fisiologia , Rememoração Mental/fisiologia
3.
Acta Neurol Scand ; 135(1): 115-121, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27531652

RESUMO

OBJECTIVE: A transient decrease in seizure frequency has been identified during therapeutic brain stimulation trials with stimulator in patients in the inactive sham group. This study was performed to examine whether the implantation of intracranial electrodes decreases seizure occurrence and explores factors that may be associated. METHODS: A retrospective review of 193 patients was performed, all evaluated with both scalp video EEG monitoring and intracranial EEG (iEEG) monitoring. Data about the number of seizures per day during the monitoring period, the number of days until the first seizure, anti-epileptic drugs (AEDs), pain medications, types of implanted electrodes, and anesthetic agents were reviewed. We conducted a repeated measure analysis for counted data using generalized estimating equations with a log-link function and adjustment for number of days and anti-epileptic medication load on the previous day to compare seizure frequencies between scalp and iEEG monitoring. RESULTS: The time to the first seizure was significantly prolonged during iEEG monitoring as compared to scalp monitoring after correction for AED withdrawal (hazard ratio: 0.81, CI 0.69-0.96). During scalp video EEG monitoring, patients experienced an average of 1.09 seizures/day vs 1.27 seizures/day during iEEG monitoring (P=.066). There was no significant difference in seizure frequency in patients that received craniotomy vs burr holes only for intracranial implantation. An increasing number of electrodes implanted increased the delay to seizures (P=.01). Of all anesthetic agents used, desflurane seemed to have an anticonvulsive effect compared to other anesthetics (P=.006). Pain medication did not influence delay to seizures. SIGNIFICANCE: Seizures are delayed during iEEG as opposed to scalp monitoring illustrating the "implantation effect" previously observed. Surgical planning should account for longer monitoring periods, particularly when using larger intracranial arrays.


Assuntos
Craniotomia/efeitos adversos , Estimulação Encefálica Profunda/efeitos adversos , Convulsões/terapia , Adulto , Estudos de Casos e Controles , Estimulação Encefálica Profunda/métodos , Eletrodos Implantados/efeitos adversos , Feminino , Humanos , Masculino , Convulsões/fisiopatologia
4.
Adv Clin Exp Med ; 26(9): 1319-1327, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29442451

RESUMO

BACKGROUND: Gastric residence time is the key factor affecting the bioavailability of active pharmaceutical ingredients absorbed mainly through the gastric mucous membrane and influencing the local activity of some drugs. OBJECTIVES: The aim of this study was the development of a new composition of non-effervescent floating tablets and the evaluation of the effect of an anionic polymer and compressive force on the floating properties and release characteristics of tablets containing a model alkaline drug, chlorhexidine (CHX). MATERIAL AND METHODS: Direct compression was applied to a polyacrylic acid derivative and sorbitol to fabricate the tablets. Drug release was analyzed using several kinetic models. The formulations floated on the surface of the fluid for 24 h. The values of the rate constants, statistical parameters, and half-release time (t0.5) were calculated. RESULTS: The diffusion coefficient n falls between 0.54 ±0.02 and 0.81 ±0.03 for most formulations. The floating time (FT) and floating lag time (FLT) were found to depend on the amount of polymer incorporated in the formulations. A high compressive force sustained the release of the drug but reduced the FT and FLT. Based on the FT and t0.5, it was determined that the C1 composition is the optimal formulation with FT >24 h and t0.5 between 113 ±2 and 144 ±13 min, depending on the drug release model. CONCLUSIONS: The application of an anionic polymer results in a prolonged release of the drug from the tablets and allows them to float on fluid surfaces.


Assuntos
Clorexidina/química , Química Farmacêutica , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Polímeros , Comprimidos
5.
Radiologe ; 54(12): 1204-12, 2014 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-25503519

RESUMO

BACKGROUND: Magnetic resonance imaging (MRI) of the lungs is becoming increasingly appreciated as a third diagnostic imaging modality besides chest x-ray and computed tomography (CT). Its value is well acknowledged for pediatric patients or for scientific use particularly when radiation exposure should be strictly avoided. However, the diagnosis of interstitial lung disease is the biggest challenge of all indications. The objective of this article is a summary of the current state of the art for diagnostic MRI of interstitial lung diseases. MATERIAL AND METHODS: This article reflects the results of a current search of the literature and discusses them against the background of the authors own experience with lung MRI. RESULTS: Due to its lower spatial resolution and a higher susceptibility to artefacts MRI does not achieve the sensitivity of CT for the detection of small details for pattern recognition (e.g. fine reticulation and micronodules) but larger details (e.g. coarse fibrosis and honeycombing) can be clearly visualized. Moreover, it could be shown that MRI has the capability to add clinically valuable information on regional lung function (e.g. ventilation, perfusion and mechanical properties) and inflammation with native signal and contrast dynamics. DISCUSSION: In its present state MRI can be used for comprehensive cardiopulmonary imaging in patients with sarcoidosis or for follow-up of lung fibrosis after initial correlation with CT. Far more indications are expected when the capabilities of MRI for the assessment of regional lung function and activity of inflammation can be transferred into robust protocols for clinical use.


Assuntos
Aumento da Imagem/métodos , Doenças Pulmonares Intersticiais/patologia , Pulmão/patologia , Imageamento por Ressonância Magnética/métodos , Diagnóstico Diferencial , Humanos
6.
Epilepsy Behav ; 41: 66-73, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25305435

RESUMO

OBJECTIVE: This study provides population-based estimates of psychosocial health among U.S. adults with epilepsy from the 2010 National Health Interview Survey. METHODS: Multinomial logistic regression was used to estimate the prevalence of the following measures of psychosocial health among adults with epilepsy and those without epilepsy: 1) the Kessler-6 scale of serious psychological distress; 2) cognitive limitation, the extent of impairments associated with psychological problems, and work limitation; 3) social participation; and 4) the Patient-Reported Outcome Measurement Information System Global Health Scale. RESULTS: Compared with adults without epilepsy, adults with epilepsy, especially those with active epilepsy, reported significantly worse psychological health, more cognitive impairment, difficulty in participating in some social activities, and reduced health-related quality of life (HRQOL). CONCLUSIONS: These disparities in psychosocial health in U.S. adults with epilepsy serve as baseline national estimates of their HRQOL, consistent with Healthy People 2020 national objectives on HRQOL.


Assuntos
Transtornos Cognitivos/psicologia , Epilepsia/psicologia , Qualidade de Vida/psicologia , Participação Social/psicologia , Adolescente , Adulto , Idoso , Transtornos Cognitivos/epidemiologia , Transtornos Cognitivos/etiologia , Epilepsia/complicações , Epilepsia/epidemiologia , Feminino , Inquéritos Epidemiológicos/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Estados Unidos/epidemiologia , Adulto Jovem
7.
Vasa ; 39(4): 319-24, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21104621

RESUMO

BACKGROUND: Endovascular treatment is an increasingly used therapeutic option in patients with chronic atherosclerotic occlusive mesenteric disease. Purpose of this study was evaluation of patency and mortality in patients treated with visceral artery percutaneous transluminal angioplasty (PTA) or stenting including follow-up. PATIENTS AND METHODS: A retrospective review of 17 consecutive patients (4 women, 13 men) with endovascular treatment for symptomatic chronic mesenteric ischemia from 1998 to 2004 was performed. Mean follow-up period was 42 months. Patient demographics, interventional details, primary and/or secondary patency and mortality were recorded. Cumulative mortality and patency rates were determined using Kaplan-Meier life table analysis. RESULTS: Twenty-six interventions (PTA alone n=13, PTA and stenting n=13) were performed in 17 patients. Interventions were performed in the superior mesenteric artery (n=13) and celiac artery (n=13). The re-intervention rate was 30% (6/26). Re-interventions were performed for the superior mesenteric artery (n=4) and celiac artery (n=2). Cumulative overall 1-year results were primary patency rate 81%, secondary patency rate 94%, and survival rate 82%. Cumulative 10-year results were primary patency rate 73%, secondary patency rate 94%, and survival rate 65%. The 10-year secondary patency rate was 100% in patients post initial stenting and 86% in patients post initial PTA. CONCLUSIONS: Long-term follow-up post endovascular treatment for chronic mesenteric ischemia demonstrated a considerable overall secondary patency rate of 94%. However, the long-term secondary patency rate was higher in patients post initial stenting compared to PTA alone.


Assuntos
Angioplastia com Balão/instrumentação , Aterosclerose/terapia , Procedimentos Endovasculares/instrumentação , Oclusão Vascular Mesentérica/terapia , Stents , Adulto , Idoso , Idoso de 80 Anos ou mais , Angioplastia com Balão/efeitos adversos , Angioplastia com Balão/mortalidade , Aterosclerose/complicações , Aterosclerose/diagnóstico por imagem , Aterosclerose/mortalidade , Constrição Patológica , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/mortalidade , Feminino , Humanos , Estimativa de Kaplan-Meier , Tábuas de Vida , Masculino , Oclusão Vascular Mesentérica/diagnóstico por imagem , Oclusão Vascular Mesentérica/etiologia , Oclusão Vascular Mesentérica/mortalidade , Pessoa de Meia-Idade , Radiografia , Recidiva , Estudos Retrospectivos , Índice de Gravidade de Doença , Suíça , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular
9.
AAPS PharmSciTech ; 10(3): 1048-57, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19669894

RESUMO

The objective of this work was to apply a new apparatus for the assay of the drug release from lozenge tablet with a potential use in the treatment of oral candidosis and another conditions connected to microbial etiopathology in the oral cavity or as an antiplaque factor. Also, an approach to comparison of the applied method with the classical paddle apparatus method was performed. Tablets containing chlorhexidine dihydrochloride were formulated with granulated sorbitol of different grades (diameter of 110, 180, 480, and 650 microm, respectively), lactose, and magnesium stearate as excipients. Tablets were obtained through direct compression, and uniformity of weight, friability, breaking strength, disintegration, and release rate were evaluated. The disintegration times ranged between 10 and 21 min. In the next stage of the study, the release of chlorhexidine from lozenges prepared with granulated sorbitol grade 110 microm and different amounts of lactose and magnesium stearate was assessed. Two stages were observed during the release of chlorhexidine dihydrochloride from the lozenges, assayed by the classical paddle apparatus method II USP. In the first stage, release rates were between 2.6 x 10(-2) and 4.7 x 10(-2) min(-1), in the second stage between 1.7 x 10(-3) and 7.7 x 10(-3) min(-1). In the case of the in-house method, the release was near to first-order kinetics through the entire release experiment, with rate constants between 3.6 x 10(-2) and 6.6 x 10(-2) min(-1). The sorbitol granulate of granules with diameter 110 microm was found to be most suitable for the lozenges with chlorhexidine dihydrochloride and lactose. The in-house release method, proposed in this work, seems to be more realistic for the preliminary assessment of predicted drug concentrations in the oral cavity after the intake of a lozenge.


Assuntos
Clorexidina/administração & dosagem , Desinfetantes/administração & dosagem , Sorbitol/química , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Química Farmacêutica , Cárie Dentária/tratamento farmacológico , Placa Dentária/tratamento farmacológico , Composição de Medicamentos , Dureza , Cinética , Excipientes Farmacêuticos , Pós , Solubilidade , Espectrofotometria Ultravioleta
10.
Eur Heart J ; 30(10): 1237-44, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19264750

RESUMO

AIMS: The aim of this study was to investigate the 12-month incidence, predictive factors, and prognosis of sustained ventricular tachycardia (VT) in chronic heart failure patients implanted with biventricular pacemakers without a back-up defibrillator (CRT-P), assessed by continuous intracardiac ventricular electrograms. METHODS AND RESULTS: The Mona Lisa study, a prospective, multicentre, cohort study, designed to determine the incidence of sustained VT and its prognostic impact in CRT-P recipients within the year after implant enrolled 198 patients with moderate or severe chronic heart failure, despite optimal pharmacological therapy. An independent committee reviewed the data from all arrhythmic episodes as well as causes of death according to predefined criteria. During a mean follow-up of 9.8 +/- 3.1 months after implantation, 8 patients experienced at least one episode of sustained VT [4.3%; 95% confidence interval (CI), 1.1-7.5] and 21 deaths occurred, giving a 12-month mortality rate of 11.7% (95% CI, 6.4-16.9). The presence of sustained VT was associated with a high risk of sudden cardiac death (SCD) and the lowest 12-month overall survival (P < 0.0001). CONCLUSION: The incidence of sustained VT remains relatively low in the first year after CRT-P implantation, but when present appears closely associated with short-term adverse outcomes, especially SCD. This emphasizes the possible value of remote monitoring to detect high-risk patients for urgent upgrading.


Assuntos
Morte Súbita Cardíaca/epidemiologia , Insuficiência Cardíaca/terapia , Marca-Passo Artificial , Taquicardia Ventricular/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Estimulação Cardíaca Artificial/efeitos adversos , Causas de Morte , Técnicas Eletrofisiológicas Cardíacas/métodos , Métodos Epidemiológicos , Feminino , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/mortalidade
11.
J Psychosom Res ; 66(3): 195-201, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19232231

RESUMO

OBJECTIVE: The aim of this study was to examine the components of vital exhaustion (VE) in chronic heart failure (CHF) patients and to examine whether psychological symptom profiles based on these components are differently associated with health status and cardiac rehospitalization. METHODS: Consecutive CHF patients (N=381) were assessed for VE at baseline using the Maastricht Questionnaire and assessed for health status at 6-month follow-up using the Minnesota Living with Heart Failure Questionnaire. Information on cardiac rehospitalization was obtained from the patients' medical records. RESULTS: Principal component analysis revealed four essential features of VE: fatigue, cognitive-affective depressive symptoms, sleep difficulties, and lack of concentration. Latent class cluster analysis using these components identified three subgroups with different symptom profiles: a subgroup without VE, a first vitally exhausted subgroup (VE1; fatigue and lack of concentration, but with a relative absence of cognitive-affective depressive symptoms and sleep difficulties), and a second more severe, vitally exhausted subgroup (VE2; elevated levels of all components). Both vitally exhausted subgroups were more likely to have impaired health status (VE1: beta=.36, P<.001; VE2: beta=.71, P<.001). VE2 was also associated with an increased risk of cardiac rehospitalization at 6-month follow-up (odds ratio=2.98; 95% confidence interval=1.01-8.83; P=.049). CONCLUSIONS: VE in CHF comprised four components (fatigue, cognitive-affective depressive symptoms, sleep difficulties, and lack of concentration) from which three different symptom profiles were derived. Subgroups with symptoms of VE were associated with adverse clinical outcome in CHF. In clinical practice, these results may help identify distinct groups of patients with potentially differential risks of adverse health outcomes.


Assuntos
Insuficiência Cardíaca/psicologia , Fadiga Mental/psicologia , Transtornos Psicofisiológicos/psicologia , Papel do Doente , Idoso , Comorbidade , Depressão/diagnóstico , Depressão/psicologia , Feminino , Seguimentos , Nível de Saúde , Insuficiência Cardíaca/diagnóstico , Humanos , Masculino , Fadiga Mental/diagnóstico , Pessoa de Meia-Idade , Readmissão do Paciente , Estudos Prospectivos , Transtornos Psicofisiológicos/diagnóstico , Distúrbios do Início e da Manutenção do Sono/diagnóstico , Distúrbios do Início e da Manutenção do Sono/psicologia , Inquéritos e Questionários , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/psicologia
12.
Eur J Heart Fail ; 9(9): 922-7, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17631047

RESUMO

OBJECTIVE: To examine the role of clinical and psychological characteristics as predictors of fatigue in CHF. BACKGROUND: Little is known about predictors of fatigue in CHF. Next to heart failure characteristics, depressive symptoms and type-D personality may explain individual differences in fatigue. METHODS: At baseline, 136 CHF outpatients (age

Assuntos
Fadiga/etiologia , Insuficiência Cardíaca/complicações , Idoso , Doença Crônica , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/psicologia , Fadiga/psicologia , Feminino , Insuficiência Cardíaca/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes de Personalidade , Estudos Prospectivos
13.
J Psychosom Res ; 61(4): 493-9, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17011357

RESUMO

OBJECTIVE: A recent meta-analysis suggests that the impact of post-myocardial infarction (MI) depression on cardiac prognosis has decreased over the last decade. We tested whether depression still significantly affects prognosis in the present health care situation. METHODS: Four hundred ninety-four MI patients were screened for depression. Patients with depression were compared with patients without on cardiovascular events (fatal or nonfatal) during an average follow-up of 2.5 years. Demographic characteristics and cardiac risk factors were controlled for. RESULTS: We found that depression was associated with the occurrence of cardiovascular events in both univariate [hazard ratio (HR), 1.84; 95% confidence interval, 1.24-2.72] and multivariate analysis (HR, 1.56; 1.02-2.38). CONCLUSIONS: Depression still has an independent impact on cardiac prognosis after MI, but this influence is smaller than found in early studies. Improvements in general care for MI and better recognition and treatment of post-MI depression may have decreased the impact of depression on prognosis.


Assuntos
Transtorno Depressivo Maior/etiologia , Infarto do Miocárdio/psicologia , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Prognóstico , Índice de Gravidade de Doença , Perfil de Impacto da Doença , Fatores de Tempo
14.
Eur J Pharm Biopharm ; 64(3): 343-50, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16914296

RESUMO

The theoretically expected breaking strength of tablets from powder mixtures is often calculated by the weighted arithmetic mean from the breaking strength of the single components, which corresponds to a linear interpolation. The validity of this additivity of fracture strength shall be evaluated by the underlying model of parallel couplings. It assumes the components linked in parallel with respect to the direction of loading during diametrical strength testing. Parallel couplings were experimentally realised by the preparation of double layer tablets from crystalline and spray-dried lactose on the one hand and from maltitol and metamizol-sodium on the other. Constant total true volumes of the single substances and of layered powders in varying ratios of true volume were compressed on an eccentric tabletting machine to constant geometric mean punch force. Simulated crushing profiles of parallel couplings were derived from force-displacement profiles measured during diametrical compression of the one-component tablets. At given finely graded deformation levels, the forces exerted by the components during loading were added in the proportion of the true volume fractions of the components in the coupling. The results from the experiments and from the simulations are in good accordance. They demonstrate that a linear change of the crushing strength in dependence on the true volume fraction of the components can only be assumed if the single components deform to the same extent up to the point of fracture. This behaviour was approximately found with the parallel lactose system. In all other cases it must be expected that the crushing strength of parallel systems will be lowered beneath the weighted arithmetic mean values or even below the crushing strength of the single components. The latter was observed with the maltitol-metamizol combinations. Thus, if tablets from binary powder mixtures exhibit a crushing strength depression, this is not necessarily an indication of weak bonding between the components or of structural defects.


Assuntos
Anti-Inflamatórios não Esteroides/química , Excipientes/química , Pós , Comprimidos , Química Farmacêutica , Força Compressiva , Simulação por Computador , Dipirona/química , Lactose/química , Maltose/análogos & derivados , Maltose/química , Modelos Químicos , Álcoois Açúcares/química , Resistência à Tração
15.
Eur J Cardiovasc Prev Rehabil ; 12(4): 341-6, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16079641

RESUMO

BACKGROUND: Chronic heart failure (CHF) is a serious condition that is associated with impaired health status and a high prevalence of depressive symptoms. To date, little is known about the determinants of health status and depressive symptoms in CHF. Therefore, the aim of this study was to assess whether Type D personality is associated with impaired health status and increased depressive symptoms in heart failure patients, independent of disease characteristics. METHODS: Eighty-four patients (63 men and 21 women, mean age=65.9+/-12.1 years) with systolic CHF completed four questionnaires to assess Type D personality (14-item Type D Personality Scale [DS14]), health status (Minnesota Living with Heart Failure Questionnaire [MLWHFQ]), depressive symptoms (Center for Epidemiological Studies Depression Scale [CES-D]) and mood status (Global Mood Scale [GMS]) when visiting an outpatient heart failure clinic. Information on clinical variables was obtained from patients' medical records. RESULTS: Type D patients were more likely to experience impairment in health status (18/38=47%) as compared to non-Type Ds (11/46=24%), P=0.027. They also more often reported symptoms of depression; namely 18 of 38=47% versus 6 of 46=13%, P=0.001. When controlling for severity and etiology of CHF, age and gender, Type D remained a significant associate of impaired health status [odds ratio (OR) 3.0, 95% confidence interval (CI) 1.12-7.78] and depressive symptoms (OR 6.3, 95% CI 2.08-19.12). CONCLUSIONS: Type D was associated with impaired health status and increased depressive symptoms in CHF patients. These preliminary findings demonstrate the value of including personality factors in CHF research.


Assuntos
Depressão/fisiopatologia , Depressão/psicologia , Nível de Saúde , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/psicologia , Personalidade , Afeto , Fatores Etários , Idoso , Doença Crônica , Feminino , Indicadores Básicos de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Índice de Gravidade de Doença
16.
Eur J Pharm Biopharm ; 60(1): 133-45, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15848065

RESUMO

The weighted arithmetic mean from values of a feature derived from the individual components is often used to calculate the theoretically expected compression behaviour of powder mixtures if no interparticulate interactions between the components occur. Alternatively, simulated and experimental double layer tablets are presented. The suitability of the various methods to serve as a reference for the assessment of the compression behaviour of powder mixtures shall be compared. Narrow and similar sieve fractions of maltitol and metamizol were mixed in various ratios of true volumes. Constant total true volumes of the single substances, powder mixtures, and layered powders of the same composition were compressed on an eccentric tabletting machine to a constant maximum geometric mean punch force. In addition, the compression of double layer tablets was mathematically simulated from the dynamic relative density-force data of the pure materials. At a given momentary force, the relative density of a simulated double layered powder bed is given by the harmonic mean of the relative density values of the pure materials weighted by their true volume fractions. The results show that the total, the net, and the expansion work change indeed almost linearly with the true volume fraction of the components in the double layer tablets, with the consequence that the plasticity index (=net work/total workx100) proceeds non-linearly. The slope of the Heckel plot 'at pressure' and the apparent mean yield pressure obtained from these Heckel data are non-linearly related to the true volume fraction. If the weighted arithmetic mean is used to analyse the compression behaviour of the powder mixtures, results are obtained which are incompatible or even contradictory between interrelated features. On the other hand, the double layer model provides a consistent evaluation. A good agreement between the results of the experimental and the simulated double layer tablets is found.


Assuntos
Composição de Medicamentos , Pós , Comprimidos , Algoritmos , Química Farmacêutica , Interpretação Estatística de Dados , Excipientes/química , Modelos Estatísticos
17.
Eur J Pharm Biopharm ; 55(2): 215-9, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12637100

RESUMO

The uncertainty of some characteristic parameters describing the course of the tabletting process, namely the area quotient according to Emschermann and Müller, the apparent net work, the slope of the Heckel-plot, and the parameters of the modified Weibull function, was calculated according to the German norm DIN 1319-4 1999. The method allows to consider random and systematic uncertainties in a consistent way as variances of normal and rectangular probability distributions, respectively, or other suitable probability distributions based on Bayesian statistics and the principle of maximum entropy. So, random and systematic uncertainties known from a calibration and validation study of the measurement of force and displacement, and the uncertainty of the true density were included meaningfully into the uncertainty of the resulting tabletting parameters using the propagation of uncertainties according to the Gauss method. The standard uncertainty for the results calculated this way seems to be suitable for a critical evaluation of the tabletting data.


Assuntos
Composição de Medicamentos/métodos , Comprimidos , Teorema de Bayes , Intervalos de Confiança , Composição de Medicamentos/instrumentação , Probabilidade , Reprodutibilidade dos Testes , Tecnologia Farmacêutica , Incerteza
18.
J Am Coll Cardiol ; 40(11): 1955-60, 2002 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-12475455

RESUMO

OBJECTIVES: This study was done to identify the best treatment for an isolated high-grade stenosis of the proximal left anterior descending coronary artery (LAD). BACKGROUND: Percutaneous transluminal coronary angioplasty with stenting (PCI) and off-pump coronary artery bypass grafting (surgery) are used to treat single-vessel disease of a high-grade stenosis of the proximal LAD. Midterm results of both treatments are compared in this prospective randomized study. METHODS: In a single-center prospective trial, we randomly assigned 102 patients with a high-grade stenosis of the proximal LAD (American College of Cardiology/American Heart Association classification type B2 or C) to PCI (n = 51) or surgery (n = 51). Primary composite end point was freedom from Major Adverse Cardiac and Cerebrovascular Events (MACCE) at follow-up, including death, myocardial infarction, cerebrovascular accident, and repeat target vessel revascularization (TVR). Secondary end points were angina pectoris class and need for antianginal medication at follow-up. Analysis was by intention-to-treat (ITT) and received treatment (RT). RESULTS: Mean follow-up time was three years (90% midrange, two to four years). Incidence of MACCE was 23.5% after PCI and 9.8% after surgery; p = 0.07 ITT (24.1% vs. 8.3%; p = 0.04 RT). After surgery a significantly lower angina pectoris class (p = 0.02) and need for antianginal medication (p = 0.01) was found compared to PCI. Target vessel revascularization was 15.7% after PCI and 4.1% after surgery (p = 0.09). CONCLUSIONS: At three-year follow-up (range, two to four years), a trend in favor of surgery is observed in regard to MACCE-free survival with a significantly lower angina pectoris status and significantly lower need for antianginal medication.


Assuntos
Angioplastia Coronária com Balão , Artérias/patologia , Artérias/cirurgia , Estenose Coronária/terapia , Vasos Coronários/patologia , Vasos Coronários/cirurgia , Stents , Angioplastia Coronária com Balão/mortalidade , Implante de Prótese Vascular/mortalidade , Angiografia Coronária , Ponte de Artéria Coronária/mortalidade , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/epidemiologia , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Fatores de Risco , Índice de Gravidade de Doença , Resultado do Tratamento
19.
Int J Pharm ; 248(1-2): 101-14, 2002 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-12429464

RESUMO

Two different types of pellets, i.e. drug-free sugar spheres, and pellets, spray-layered with crystalline theophylline and coated with Eudragit RS/RL, were tabletted each in combination with matrix-forming powder mixtures of Avicel PH200 and PEG 4000. The die fills from pellets and powder mixtures were regarded as two-compartment systems with a volume fraction of the pellets being limited to 0.52 corresponding to a cubic lattice, and the maximum degrees of densifications were adjusted related to the matrix. To data measured during single compression cycles on an instrumented eccentric tabletting machine and transformed appropriately, the Kawakita equation, the Heckel function, and a modified Weibull function were fitted, and the total work of compression was calculated. The Kawakita model fitted well systems with both types of pellets. Its parameters reflected the additional densification of the theophylline pellets separately from that of the matrix formers. The Heckel function could only be applied to systems containing non-porous sugar spheres, since the theophylline pellets underwent considerable densification and deformation. Only, when the Heckel porosity function was related to the volume fraction of the matrix, excluding the sugar spheres, the approximately linear regions for mixtures with increasing volume proportions of sugar spheres occured in comparable regions of densification. Parameters of the modified Weibull function demonstrated an increasing resistance against densification with increasing amounts of pellets. The total work of compression increased steeply with increasing volume fractions for pellets from 0.42 to 0.46 indicating, that the resistance against densification already rose when the pellets were still isolated. In conclusion, the combination of dynamic and kinetic models provides a comprehensible insight into the process of tabletting powder mixtures with pellets. Particularly, the Kawakita model was a suitable tool to differentiate the actual changes in porosity during compression from the compressibility of such complex systems.


Assuntos
Implantes de Medicamento/química , Modelos Químicos , Comprimidos/química , Força Compressiva , Implantes de Medicamento/farmacocinética , Cinética , Microesferas , Porosidade , Comprimidos/farmacocinética , Tecnologia Farmacêutica/métodos
20.
J Thorac Cardiovasc Surg ; 124(1): 130-5, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12091818

RESUMO

OBJECTIVE: We sought to compare minimally invasive coronary artery bypass grafting (surgical intervention) with percutaneous transluminal coronary angioplasty with primary stenting (stenting) in patients having an isolated high-grade stenosis (American College of Cardiology/American Heart Association classification type B2 or C) of the proximal left anterior descending coronary artery. At 6 months, both procedures were compared on the basis of quantitative angiography and clinical outcome. METHODS: Both treatments were compared in a single-center, prospective, randomized study. The primary end point of this study was quantitative angiographic outcome at 6 months. The secondary end point was 6-month clinical outcome. Statistical analysis was performed in accordance with the intention-to-treat principle. RESULTS: From March 1997 to September 1999, patients with angina pectoris caused by an isolated high-grade stenosis of the proximal left anterior descending coronary artery were randomly assigned to surgical intervention (n = 51) or stenting (n = 51). At 6 months, quantitative coronary angiography showed an anastomotic stenosis rate of 4% after surgical intervention and a restenosis rate of 29% after stenting (P <.001). Periprocedural events did not significantly differ between surgical intervention and stenting. After surgical intervention, 2 patients died; no patients died after stenting. After 6 months, no significant difference was found for major adverse cardiac or cerebral events and need for repeat target vessel revascularization. After 6 months, return of angina pectoris, physical work capacity, and use of antianginal drugs did not significantly differ between treatments. CONCLUSIONS: After 6 months, surgical intervention had a significantly better angiographic outcome than stenting in patients with an isolated high-grade stenosis of the proximal left anterior descending coronary artery. Clinical outcome did not significantly differ between treatments.


Assuntos
Angioplastia Coronária com Balão , Ponte de Artéria Coronária , Estenose Coronária/terapia , Stents , Angina Pectoris/etiologia , Angiografia Coronária , Estenose Coronária/complicações , Estenose Coronária/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos , Estudos Prospectivos , Fatores de Tempo
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