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1.
Eur Rev Med Pharmacol Sci ; 27(9): 4006-4018, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37203824

RESUMO

OBJECTIVE: Mitral regurgitation (MR) represents an important feature in patients with hypertrophic cardiomyopathy (HCM) due to left ventricular outflow tract (LVOT) obstruction and mitral valve systolic anterior motion (SAM). Mitral valve anatomical variants associated with HCM also contribute to the severity of MR. The aim of this study is to evaluate MR severity and its correlation with different parameters in patients with HCM using cardiac magnetic resonance imaging (cMRI). PATIENTS AND METHODS: 130 patients with HCM underwent cMRI. Parameters assessed for the quantification of MR severity were mitral regurgitation volume (MRV) and mitral regurgitation fraction (MRF). cMRI was also used to characterize LV function, left atrium volume (LAV) index, filling pressures and structural abnormalities associated with HCM, all in correlation to MR. RESULTS: Patients with HCM had mild (26.9%), moderate (52.3%) or severe (20.7%) MR. Most relevant parameters related to MR severity were MRV and MRF; other parameters with strong correlation with MR were LAV index and E/E' ratio, both increasing with its severity. Patients with LVOT obstruction had more severe MR (70.3%), 79% of them due to SAM. LV ejection fraction (LVEF) increased proportionally with the severity of MR, while LV strain (LAS) was inversely correlated with it. Independent predictors for quantifying the severity of MR, after the adjustment for covariates, were MRV, MRF, SAM, LAV index and E/E'. CONCLUSIONS: cMRI can accurately assess MR in patients with HCM, especially by using novel indicators, MRV and MRF respectively, along with LAV index and E/E' ratio. Severe MR, due to SAM, is more frequent in the obstructive form of HCM (HOCM). Also, the severity of MR is significantly associated with significantly associated with MRV, MRF, LAV index and E/E' ratio.


Assuntos
Cardiomiopatia Hipertrófica , Insuficiência da Valva Mitral , Obstrução do Fluxo Ventricular Externo , Humanos , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/complicações , Cardiomiopatia Hipertrófica/complicações , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Valva Mitral , Átrios do Coração , Imageamento por Ressonância Magnética , Obstrução do Fluxo Ventricular Externo/diagnóstico por imagem , Obstrução do Fluxo Ventricular Externo/complicações
2.
Eur Rev Med Pharmacol Sci ; 25(11): 4074-4085, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34156686

RESUMO

OBJECTIVE: Coronary computed tomography angiography (CCTA) is becoming increasingly useful for the diagnosis of coronary artery disease (CAD). Coronary calcium score (CCS), epicardial fat volume (EFV), and number of coronary plaques (NoP) add important information for the risk stratification and prognosis prediction of these patients. However, evidence about their ability to predict obstructive CAD is limited. We sought to evaluate the ability of CCTA parameters in predicting obstructive CAD. PATIENTS AND METHODS: We conducted a cross-sectional, single-center study on patients at risk to develop CAD. CAD was defined as coronary stenosis > 50% after the other one (CCS, EFV and NoP were determined by CCTA). CCS was then ranked 5 severity groups: 0, 1-99, 100-399,400-999, and ≥1000. NoPs were classified in four categories: no plaques, 1-5, 6-10 and ≥10. Logistic regression analyses were performed, and statistical analysis was considered significant if p<0.05. RESULTS: Of all 540 patients (55.8±11.1 years) who met the enrolment criteria, 98 had obstructive CAD. CCS, EFV and NoP were significantly associated with the presence of obstructive CAD (p<0.0001). The area under the receiver operating characteristics (ROC) analysis revealed significant cut-off values (p<0.0001) of CCS (70.3), EFV (40.8), NoP (4) for predicting obstructive CAD. Their association proved to have an AUC of 0.969, and a specificity of 95%. A scoring system based on regression coefficients which proved to have statistical significance for obstructive CAD as further constructed. It included EFV, CCS and left ventricular ejection fraction. This scoring system significantly predicted obstructive CAD for a cut-off value of 62.46, with a NPV of 96.3%. CONCLUSIONS: The combined use of CCS, EFV and NoPs increases the predictive ability for obstructive CAD of each parameter used alone. These could be useful for developing a novel scoring system.


Assuntos
Angiografia por Tomografia Computadorizada , Doença da Artéria Coronariana/diagnóstico por imagem , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
3.
Clin Radiol ; 76(2): 161.e19-161.e28, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33109351

RESUMO

AIM: To investigate age-related changes of the pulmonary artery (PA) using cardiac magnetic resonance imaging (cMRI) in healthy subjects. MATERIALS AND METHODS: A cross-sectional observational study was conducted on apparently healthy subjects who underwent PA velocity-encoded cMRI. cMRI was used to determine PA stiffness parameters such as PA elasticity, relative area change (PA-RAC) and pulse-wave velocity (PA-PWV), and PA flow parameters by subtracting simultaneous forward flow (FF) and backward flow (BF) velocity across the PA cross-section. Data were presented in five age and sex matched groups. RESULTS: One hundred and fifty subjects (20-70 years, 75 men) met the enrolment criteria. PA elasticity and PA-RAC significantly decreased with age (p<0.001), while PA-PWV, regurgitant volume (Vreg) and backward flow volume (VBF) increased in the elderly (p<0.001). Linear regression analysis indicated that PA elasticity (r=-0.441, p<0.0001) and PA-RAC (r=-0.484, p<0.0001) were indirectly and negatively associated with advancing age, whereas PAmin (r=0.331, p<0.0001), PA-PWV (r=0.490, p<0.0001), VReg (r=0.335, p<0.0001) and VBF (r=0.349, p<0.0001) were directly associated with age. Multivariate analysis indicated that age was independently associated with Vreg and VBF, and the addition of PAmin and PA-PWV marginally increased its predictive capacity. CONCLUSION: Aging significantly increases cMRI-based PA flow and stiffness parameters. These could become relevant markers of subclinical changes of the PA geometry in healthy subjects.


Assuntos
Envelhecimento/fisiologia , Imageamento por Ressonância Magnética/métodos , Artéria Pulmonar/fisiologia , Análise de Onda de Pulso/métodos , Rigidez Vascular/fisiologia , Adulto , Fatores Etários , Idoso , Velocidade do Fluxo Sanguíneo/fisiologia , Estudos Transversais , Feminino , Coração/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Adulto Jovem
4.
Diabet Med ; 37(2): 335-342, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-30924960

RESUMO

AIM: To investigate whether the sensory-motor impairment attributable to diabetic peripheral neuropathy would affect control of the accelerator pedal during a driving simulator task. METHODS: A total of 32 active drivers, 11 with diabetic peripheral neuropathy (mean ± sd age 67±5.0 years), 10 with diabetes but no neuropathy (diabetes group; mean ± sd age 62±10 years), and 11 healthy individuals without diabetes (healthy group; mean ± sd age 60±11 years), undertook a test on a dynamometer to assess ankle plantar flexor muscle strength and ankle joint proprioception function of the right leg, in addition to a driving simulator task. The following variables were measured: maximal ankle plantar flexor muscle strength; speed of strength generation (Nm/s); and ankle joint proprioception (ankle repositioning error, degrees). In the driving simulator task, driving speed (mph), accelerator pedal signal (degrees) and the duration of specific 'loss-of-control events' (s) were measured during two drives (Drive 1, Drive 2). RESULTS: Participants with diabetic peripheral neuropathy had a lower speed of strength generation (P<0.001), lower maximal ankle plantar flexor muscle strength (P<0.001) and impaired ankle proprioception (P=0.034) compared to healthy participants. The diabetic peripheral neuropathy group drove more slowly compared with the healthy group (Drive 1 P=0.048; Drive 2 P=0.042) and showed marked differences in the use of the accelerator pedal compared to both the diabetes group (P=0.010) and the healthy group (P=0.002). Participants with diabetic peripheral neuropathy had the longest duration of loss-of-control events, but after one drive, this was greatly reduced (P=0.023). CONCLUSIONS: Muscle function, ankle proprioception and accelerator pedal control are all affected in people with diabetic peripheral neuropathy, adversely influencing driving performance, but potential for improvement with targeted practice remains possible.


Assuntos
Articulação do Tornozelo/fisiopatologia , Condução de Veículo , Neuropatias Diabéticas/fisiopatologia , Força Muscular/fisiologia , Propriocepção/fisiologia , Idoso , Estudos de Casos e Controles , Diabetes Mellitus/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dinamômetro de Força Muscular
5.
Curr Oncol ; 25(1): 49-52, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29507483

RESUMO

BACKGROUND: Across our province, post-radiotherapy (rt) handover notes are sent to family physicians (fps) after rt. Based on previous fp feedback, we created a revised post-radiotherapy handover note with more information requested by fps. The purpose of this study was to determine whether the revised handover note improved the note as a communication aid. METHODS: Potential common and rare treatment side effects, oncologist contact information, and treatment intent were added to the revised handover note. Both versions were sent alongside a questionnaire to fps. Paired t-tests were carried out to compare satisfaction differences. RESULTS: There was a response rate of 37% for the questionnaires. Significantly greater clarity in the following categories was observed: responsibility for patient follow-up (mean score improvement of 1.2 on a 7-point Likert scale, p < 0.001), follow-up schedule (1.1, p < 0.001) as well as how and when to contact the oncologist (1.4, p = 0.001). Family physicians were also more content with how the institute transitioned care back to them (1.5, p = 0.012). Overall, fps were generally satisfied with the content of the revised post-rt handover note and noted improvement over the previous version. The frequency of investigations and institute supports initiated such as counselling services were suggested further additions. CONCLUSIONS: The inclusion of potential treatment side effects, oncologist contact information, treatment intent and a well-laid out follow-up schedule were essential information needed by fps for an effective post-rt completion note. With these additions, the revised post-rt handover note showed significant improvement.

6.
J Med Syst ; 41(12): 205, 2017 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-29128996

RESUMO

Cutaneous Melanoma (CM) is a malignant tumour, and is one of the most rapidly growing cancers. Discovering a melanoma in the early stages of the disease is extremely difficult and, as such, only an invasive disease stage can be identified easily with the naked eye. Dermatoscopy is a diagnostic method intended to maximise early detection of CM performed by the dermatoscopy system. To address the limitations of existing systems a novel, wireless digital dermatoscopy system is presented for providing high-resolution images. It integrates a wire-free camera operation and offers a safe transfer of captured images to the computer. The working process of available dermatoscopy systems was studied, which are the most commonly used in everyday dermatology practice. Some findings, like operability, image quality, scalability, user-friendliness, and safeness, were used for the development of an e-Derma dermatoscopy system. An assessment method was performed by a group of dermatoscopy trained dermatologists to evaluate the quality of the testing images. Finally, a laboratory evaluation of images in regard to different parameters like sharpness, colour representation and illumination was performed with the side-by-side comparison of images of available dermatoscopy systems. e-Derma is a novel dermatoscopy system, which eliminates some limitations of existing systems and provides high-quality images. A novel low-budget highly capable dermatoscopy system is presented. The integrated wireless image transfer technology eliminates the movement limitations of a therapist. The image resolution is not limited by the integrated camera; it is easily upgradable with a wide range of on market alternative or improved camera models.


Assuntos
Dermoscopia/métodos , Melanoma/diagnóstico , Neoplasias Cutâneas/diagnóstico , Tecnologia sem Fio , Humanos , Melanoma/diagnóstico por imagem , Reprodutibilidade dos Testes , Neoplasias Cutâneas/diagnóstico por imagem , Fatores de Tempo , Interface Usuário-Computador , Melanoma Maligno Cutâneo
7.
Diabet Med ; 33(5): 644-9, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26172114

RESUMO

AIM: To examine the stepping accuracy of people with diabetes and diabetic peripheral neuropathy. METHODS: Fourteen patients with diabetic peripheral neuropathy (DPN), 12 patients with diabetes but no neuropathy (D) and 10 healthy non-diabetic control participants (C). Accuracy of stepping was measured whilst the participants walked along a walkway consisting of 18 stepping targets. Preliminary data on visual gaze characteristics were also captured in a subset of participants (diabetic peripheral neuropathy group: n = 4; diabetes-alone group: n = 4; and control group: n = 4) during the same task. RESULTS: Patients in the diabetic peripheral neuropathy group, and patients in the diabetes-alone group were significantly less accurate at stepping on targets than were control subjects (P < 0.05). Preliminary visual gaze analysis identified that patients diabetic peripheral neuropathy were slower to look between targets, resulting in less time being spent looking at a target before foot-target contact. CONCLUSIONS: Impaired motor control is theorized to be a major factor underlying the changes in stepping accuracy, and potentially altered visual gaze behaviour may also play a role. Reduced stepping accuracy may indicate a decreased ability to control the placement of the lower limbs, leading to patients with neuropathy potentially being less able to avoid observed obstacles during walking.


Assuntos
Acidentes por Quedas , Diabetes Mellitus/fisiopatologia , Neuropatias Diabéticas/fisiopatologia , Marcha Atáxica/etiologia , Transtornos da Motilidade Ocular/etiologia , Sistema Nervoso Periférico/fisiopatologia , Adulto , Idoso , Estudos de Coortes , Sinais (Psicologia) , Inglaterra/epidemiologia , Humanos , Pessoa de Meia-Idade , Destreza Motora , Transtornos da Motilidade Ocular/complicações , Transtornos da Motilidade Ocular/fisiopatologia , Projetos Piloto , Risco , Limiar Sensorial , Índice de Gravidade de Doença , Vibração , Caminhada
8.
Placenta ; 35(11): 932-6, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25149386

RESUMO

OBJECTIVE: Preeclampsia (preE), is characterized by abnormal placental invasion and function. Marinobufagenin (MBG), a cardiotonic steroid (CTS), inhibits cytotrophoblast (CTB) cell functions that are critical for normal placental development. This study tests the hypothesis that CTSs induce anti-angiogenic and anti-proliferative effects in CTB cells. METHODS: Human extravillous CTB cells of the line Sw-71, derived from first trimester chorionic villus tissue, were incubated with 0, 0.1, 1, 10, and 100 nM of each of three CTSs (MBG, cinobufatalin (CINO) and ouabain (OUB)) for 48 h. Thereafter, levels of pro-angiogenic (vascular endothelial growth factor (VEGF165), placental growth factor (PlGF)) and anti-angiogenic (soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng)) factors were measured in culture media using ELISA kits. Expression of three receptors (VEGF receptor 1 (VEGFR1), angiogenic angiotensin type 1 receptor (AT1) and anti-angiogenic angiotensin type 2 receptor (AT2)) were assayed using immunoblotting (western blots) in cell lysates. RESULTS: sFlt-1 and sEng secretion were increased while VEGF165 and PIGF were decreased in the culture media of CTB cells treated with 1 nM or more of each CTSs (p < 0.01 for each). The AT2 receptor expression was up-regulated (p < 0.05) in CTB cells treated with 1 nM or more of MBG and CINO and with 100 nM OUB, while AT1 and VEGFR1 expressions decreased (p < 0.05) with 1 nM or more of MBG and 10 nM or more of CINO and OUB. CONCLUSIONS: CTSs influence extravillous CTB cells to induce an anti-angiogenic and anti-proliferative profile.


Assuntos
Glicosídeos Cardíacos/farmacologia , Cardiotônicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Trofoblastos/efeitos dos fármacos , Bufanolídeos/farmacologia , Células Cultivadas , Feminino , Humanos , Ouabaína/farmacologia , Gravidez , Primeiro Trimestre da Gravidez , Receptor Tipo 2 de Angiotensina/metabolismo , Sistema Renina-Angiotensina , Trofoblastos/metabolismo
9.
Am J Nephrol ; 32(4): 332-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20720407

RESUMO

BACKGROUND/AIMS: Pre-eclampsia is a disorder that results in significant feto-maternal complications with yet no definitive pharmacologic intervention. One postulated etiologic mechanism is an imbalance between circulating pro-angiogenic and anti-angiogenic factors. We investigated these factors sequentially throughout pregnancy (19-21 days) in our rat model of pre-eclampsia, which involves the imposition of excessive volume expansion. METHODS: We evaluated the status of the pro-angiogenic and anti-angiogenic factors at the following time points: 3-5, 7-10 and 17-20 days of gestation. RESULTS: We have previously determined that the urinary excretion of the circulating bufodienolide, marinobufagenin, is elevated at the 3- to 5-day time period, prior to the advent of hypertension and proteinuria. At 3-5 days of pregnancy, there was no evidence of angiogenic imbalance in the normal pregnant (NP) and 'pre-eclamptic' (PDS) rats. At the 7- to 10-day time point, plasma PlGF was greater in the NP rats than in the PDS group (p < 0.05). The plasma sFlt-1/PlGF ratio in the PDS animals was greater than that in the NP rats (p < 0.05). The placental sFlt-1 and sFlt-1/PlGF ratio were greater in the PDS rats than in NP rats (p < 0.05). These changes were also present at the 17- to 20-day time point in both plasma and placenta. The administration of resibufogenin, an antagonist of marinobufagenin, early in pregnancy, prevented angiogenic imbalance. CONCLUSION: We conclude that angiogenic imbalance plays a role in the pathogenesis of pre-eclampsia in this rat model. Furthermore, the earliest event in the pathogenetic sequence appears to be the secretion and elaboration of marinobufagenin.


Assuntos
Proteínas Angiogênicas/sangue , Bufanolídeos/sangue , Pré-Eclâmpsia/sangue , Análise de Variância , Animais , Pressão Sanguínea , Bufanolídeos/administração & dosagem , Bufanolídeos/antagonistas & inibidores , Creatinina , Endoglina , Feminino , Idade Gestacional , Hematócrito , Peptídeos e Proteínas de Sinalização Intracelular/sangue , Modelos Animais , Fator de Crescimento Placentário , Pré-Eclâmpsia/etiologia , Gravidez , Proteínas da Gravidez/sangue , Proteinúria , Ratos , Ratos Sprague-Dawley , Fator de Crescimento Transformador beta/sangue , Fator A de Crescimento do Endotélio Vascular/sangue , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/sangue
10.
Placenta ; 29(3): 266-73, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18279954

RESUMO

Marinobufagenin (MBG) is an endogenous mammalian cardiotonic steroid that is involved in the inhibition of the sodium pump Na(+)/K(+)-ATPase. Increased plasma levels of MBG have been reported in patients with volume expansion-mediated hypertension and preeclampsia. We have recently demonstrated that MBG impairs both the proliferation and growth factor-induced migration of human first trimester cytotrophoblast (CTB) cells, crucial for proper placental development. However, the intracellular signaling mechanisms regulating the MBG-induced impairment of CTB differentiation, migration and invasion are unknown. The human extravillous CTB cell line SGHPL-4 was utilized for this study. The phosphorylation of MAP kinase protein ERK1/2 was evaluated by Cellular Activation of Signaling ELISA (CASE) in control CTB cells and those treated with MBG. MBG at concentrations of 10 and 100nM inhibited CTB cell proliferation, migration and invasion (60%, 50% and 50%, respectively). MBG also caused a significant decrease in the phosphorylation of ERK1/2. In addition, MBG decreased proliferation, migration, and ERK1/2 activity in another motile cell line, CHO cells. Another sodium pump inhibitor, ouabain, similarly decreased proliferation and ERK1/2 activity in CTB and CHO cells. These data suggest that the changes observed in cell function may be mediated by inhibition of Na(+)/K(+)-ATPase. We demonstrate that the MBG-induced impairment of CTB cell proliferation, migration and invasion is associated with decreased ERK1/2 activity which may be mediated by inhibition of Na(+)/K(+)-ATPase.


Assuntos
Bufanolídeos/farmacologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Trofoblastos/efeitos dos fármacos , Animais , Células CHO , Adesão Celular/efeitos dos fármacos , Cricetinae , Cricetulus , Inibidores Enzimáticos/farmacologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Ouabaína/farmacologia , Fosforilação/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Trofoblastos/fisiologia
11.
Am J Nephrol ; 28(1): 8-13, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17890853

RESUMO

BACKGROUND/AIMS: There are two major pathophysiologic processes involved in the development of hypertension: (1) expanded extracellular fluid volume and (2) vasoconstriction. We have developed a model of preeclampsia in the rat, in which excessive volume expansion (VE) plays a role. These animals excrete increased amounts of the bufodienolide, marinobufagenin (MBG), even before their hypertension and proteinuria become established. Furthermore, their hypertension is corrected by administration of resibufogenin (RBG), a compound structurally similar to MBG. METHOD: We studied two models of experimental hypertension in the nonpregnant animal, produced either by deoxycorticosterone acetate (DOCA)-salt administration or by angiotensin infusion. RESULTS: RBG administered to the DOCA-salt rats lowered blood pressure and reduced proteinuria in the VE animals, but had no affect on the rats infused with angiotensin. Furthermore, although the production of superoxide anion in the aortas of both groups of hypertensive rats was increased over control, RBG reduced these levels to normal in the VE (DOCA-salt) animals only. RBG had no effect in the angiotensin-infused rats. The urinary excretion of angiotensinogen did not rise in VE-mediated hypertension, but did increase in the angiotensin-infused rats. CONCLUSIONS: MBG plays an important role in the causation of hypertension in the VE rats, but not in the vasoconstrictive model. RBG is effective only in VE-mediated hypertension.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Bufanolídeos/farmacologia , Hipertensão Renal/tratamento farmacológico , Proteinúria/tratamento farmacológico , Angiotensina II/farmacologia , Angiotensinogênio/urina , Animais , Bufanolídeos/antagonistas & inibidores , Creatinina/sangue , Desoxicorticosterona , Modelos Animais de Doenças , Hipertensão Renal/induzido quimicamente , Masculino , Mineralocorticoides , Proteinúria/induzido quimicamente , Ratos , Ratos Endogâmicos , Cloreto de Sódio , Superóxidos/metabolismo , Vasoconstritores/farmacologia
12.
Exp Brain Res ; 180(1): 1-14, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17256168

RESUMO

When driving along a winding road, eye movements and steering are tightly linked; the driver looks across to the inside kerb of an approaching bend some time before turning the steering wheel. With the eyes leading, the oculomotor controller assists the neural centres controlling steering; prevention of any eye movements correlated with steering impairs driving, so the coordination is crucial for safety. A key question is therefore what are the limits of acceptable variation in timing and degree of coordination. Over a period of continuous driving on the open road, how much does the relative timing and degree of coordination between eye and steering movements vary? A related question is how brief a period of driving will suffice to measure these coordination parameters. Drivers' eye movements and steering were measured over different time periods ranging from 15 s to 6 min epochs of natural driving along a winding country road to establish the variability in coordination and the minimum time period required to characterise it. We show here that brief periods of driving, 30 s or less, are inadequate for describing eye-steering coordination. But a minute of driving yields an accurate description much of the time; and 2 min is sufficient both to accurately describe this relationship and to show that it is highly consistent for a given individual, and for different people driving the same route.


Assuntos
Condução de Veículo/psicologia , Movimentos Oculares/fisiologia , Retroalimentação/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Análise de Variância , Feminino , Humanos , Masculino , Percepção de Movimento/fisiologia , Percepção Espacial/fisiologia , Fatores de Tempo , Gravação em Vídeo
13.
Exp Brain Res ; 176(3): 397-412, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16896979

RESUMO

When driving along a winding road, eye movements and steering are tightly linked. When approaching a bend, the driver looks across to the inside kerb (the tangent point) some time before turning the steering wheel. All drivers we have tested show this optimal coordination, without which driving is impaired. An intriguing question is how much of the benefit for steering arises just from moving the eyes in this coordinated way (ahead of steering and in the same direction), and how much from the visual information that the eyes move to acquire, in this instance the foveated tangent point. This can be answered by dissociating the two, by reducing visibility of the road ahead (and crucially of the tangent point) to a level at which drivers might or might not choose to move their eyes but, if they do, will not gain the information they seek. Twenty subjects repeatedly drove a simulated stage of the World Rally Championship. With full visibility, they exhibited the usual coordination of eye movements and steering. Subsequently, visibility was reduced on the left hand side. Drivers who persisted in making eye movements coordinated with steering to the left, despite the fact that they could no longer see the tangent point on that side, performed better than drivers who under the identical conditions did not look to the left. This confirms that the making of coordinated eye movements itself benefits steering, even when the eye movements do not yield the visual information sought.


Assuntos
Condução de Veículo , Movimentos Oculares/fisiologia , Retroalimentação/fisiologia , Desempenho Psicomotor/fisiologia , Visão Ocular/fisiologia , Adulto , Análise de Variância , Simulação por Computador , Fixação Ocular/fisiologia , Humanos , Masculino , Percepção de Movimento/fisiologia , Estimulação Luminosa , Percepção Espacial/fisiologia
14.
Exp Brain Res ; 163(4): 411-20, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15841399

RESUMO

When approaching a bend in the road, a driver looks across to the inside kerb before turning the steering wheel. Eye movements and steering are tightly linked, with the eyes leading, which means that the oculomotor controller can assist the neural centres controlling steering. This optimum coordination is observed for all drivers; but despite being the preferred solution to the motor-control problem of successfully steering along a winding road, the question remains as to how crucial such coordinated eye and steering movements are for driving performance. Twenty subjects repeatedly drove a simulated stage of the World Rally Championship, aiming to complete the course in the fastest possible time. For the first six repetitions they used the usual coordination of eye movements and steering; for drives 7--12 they were instructed to fixate on a small spot in the centre of the screen (centre gaze). Prevention of coordination in this way impaired their performance (drives 6 and 7 compared), dramatically increasing their time taken to complete the course, equivalent to slipping 19 places down the leader board in the actual rally stage. This indicates that the usual pattern of eye movements correlated with steering is crucial for driving performance. Further experiments are suggested to reveal whether any attentional demand associated with keeping the eyes still contributes to the loss in performance.


Assuntos
Condução de Veículo/psicologia , Movimentos Oculares/fisiologia , Retroalimentação/fisiologia , Movimento/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Feminino , Humanos , Masculino , Percepção de Movimento/fisiologia , Orientação/fisiologia , Estimulação Luminosa , Percepção Espacial/fisiologia
15.
Prog Brain Res ; 148: 213-26, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15661193

RESUMO

The lateral cerebellum receives an abundance of visual input providing the link between visual and motor control centers. In this review we discuss experiments designed to increase our understanding of how visual inputs to the cerebellum are arranged in relation to the zonal organization of the cerebellar cortex, and how visual inputs are utilized to assist in the regulation of a visually guided movement. On the basis of anatomical and physiological characteristics our findings indicate that the medial-most folium in crus I of the cat lateral cerebellum can be subdivided into at least three functionally distinct zones; from lateral to medial along the length of the folium these correspond to zones D(1), lateral C(3) and C(2). Each zone displays clear differences in olivo-cortico-nuclear connectivity and in the anesthetized animal zones D(1) and C(2) both receive powerful visual inputs relayed via the climbing fiber system. Complementary experiments in awake behaving cats found that Purkinje cells located in the D(1) and D(2) zones of crus I exhibit changes in simple spike discharge time locked to target motion during a visually guided reaching task. These changes were unaffected by temporary visual denial of the target, raising the possibility that internally generated feedforward visuomotor control mechanisms are operating, in which a predictive model of the target's motion has been constructed by the CNS.


Assuntos
Cerebelo/fisiologia , Desempenho Psicomotor/fisiologia , Animais , Gatos , Cerebelo/citologia , Vias Neurais , Núcleo Olivar/citologia , Núcleo Olivar/fisiologia
16.
Gait Posture ; 21(1): 39-47, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15536032

RESUMO

Four patients suffering from primary cerebellar degeneration and healthy matched controls undertook a test of functional mobility that demanded precise foot placement at each step. Vertical and horizontal eye movements were measured (using a head mounted eye tracking system) together with footfall patterns. Healthy subjects stepped accurately onto all targets and produced a clear pattern of saccadic eye movements, fixating each target in the sequence just prior to footlift. Still video frames, showing direction of gaze while walking, provide direct visual confirmation that these saccades serve to transfer gaze between successive targets in the walkway sequence. The planning of the saccade to the next target probably provides the locomotor control system with information useful for planning the corresponding (and shortly following) step. Cerebellar patients showed characteristic locomotor and oculomotor deficits. Dysmetric saccades to fixate footfall targets were seen in 39% of steps. Analysis confirms that these multi-saccadic eye movements include an initial hypometric saccade, which undershoots the target, followed by one or more additional saccades in the same direction. Direct visualisation of gaze at the end of a saccadic sequence confirms that these additional saccades are indeed corrective resulting in a foveal image of the footfall target.


Assuntos
Doenças Cerebelares/complicações , Fixação Ocular , Transtornos da Motilidade Ocular/fisiopatologia , Movimentos Sacádicos/fisiologia , Percepção Visual , Feminino , Marcha/fisiologia , Humanos , Masculino , Percepção de Movimento , Transtornos da Motilidade Ocular/etiologia , Estudos de Amostragem , Sensibilidade e Especificidade , Percepção Espacial
17.
Alcohol Clin Exp Res ; 28(3): 402-7, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15084897

RESUMO

BACKGROUND: To understand how and why alcohol intoxication affects visually guided stepping, the eye movements and performance of 6 subjects (aged 22-35 years) were monitored as they progressed along a pathway of 18 irregularly placed stepping stones before and after consumption of an acute oral dose of alcohol. METHODS: Horizontal eye movements were measured with infrared reflectometry; footfall on or off target was monitored via copper fabric soles stuck to subjects' footwear. Breath alcohol concentration was monitored with an Alco-Sensor III breathalyzer. RESULTS: After alcohol loading, both locomotor and oculomotor deficits were evident. All subjects increased their step cycle duration-with prolonged stance, swing, and double support phases-and occasionally missed footfall targets. A large proportion of saccades made to fixate successive stepping stones were inaccurate and were accompanied by one or more corrective saccades. These problems with looking and stepping to footfall targets tended to occur together and were comparable to those seen previously in cerebellar patients undertaking the same task. CONCLUSIONS: The fact that healthy subjects acutely intoxicated by alcohol show symptoms of cerebellar dysfunction suggests that alcohol acutely and adversely affects the cerebellar contribution to performance of visually guided movements.


Assuntos
Etanol/farmacologia , Movimentos Oculares/efeitos dos fármacos , Desempenho Psicomotor/efeitos dos fármacos , Caminhada/fisiologia , Adulto , Intoxicação Alcoólica/fisiopatologia , Ataxia Cerebelar/fisiopatologia , Cerebelo/efeitos dos fármacos , Cerebelo/fisiologia , Movimentos Oculares/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Desempenho Psicomotor/fisiologia
18.
Exp Brain Res ; 146(2): 244-7, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12195526

RESUMO

In order to assess the effect of rehearsal by eye movement alone on visuomotor performance, the eye movements and visually guided stepping of two cerebellar patients were monitored before and after a first and second batch of eye-movement rehearsals, in which patients made saccadic eye movements to the first 6 footfall targets (in a sequence of 18) whilst standing stationary at the start of the walkway. There was a marked improvement in oculomotor and locomotor performance following the second batch of eye-movement rehearsal. Both patients showed reduced occurrence of saccadic dysmetria, evident as a significant increase in the proportion of single to multi-saccadic eye movements (from 46 to 77% for DB and from 75 to 94% for TP). This was accompanied by increased regularity and accuracy of stepping in both patients, and decreased stance and double support phase durations (one patient only). Separate testing confirmed that these improvements in eye movements and stepping did not result from simple repetition of the task. This is the first demonstration of a technique--rehearsal by eye movement--that improves the visuomotor performance of cerebellar patients. It is compelling evidence for our proposal that during visually guided stepping the locomotor control system is dependent on assistance from the oculomotor control system.


Assuntos
Cerebelo/fisiopatologia , Movimentos Oculares/fisiologia , Vias Neurais/fisiopatologia , Aptidão Física/fisiologia , Desempenho Psicomotor/fisiologia , Degenerações Espinocerebelares/fisiopatologia , Degenerações Espinocerebelares/reabilitação , Adulto , Marcha/fisiologia , Humanos , Locomoção/fisiologia , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica/fisiologia , Movimentos Sacádicos/fisiologia , Resultado do Tratamento
19.
J Mot Behav ; 33(2): 205-16, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11404215

RESUMO

In the present study, 2 related hypotheses were tested: first, that vision is used in a feedforward control mode during precision stepping onto visual targets and, second, that the oculomotor and locomotor control centers interact to produce coordinated eye and leg movements during that task. Participants' (N = 4) eye movements and step cycle transition events were monitored while they performed a task requiring precise foot placement at every step onto irregularly placed stepping stones under conditions in which the availability of visual information was either restricted or intermittently removed altogether. Accurate saccades, followed by accurate steps, to the next footfall target were almost always made even when the information had been invisible for as long as 500 ms. Despite delays in footlift caused by the temporary removal (and subsequent reinstatement) of visual information, the mean interval between the start of the eye movement and the start of the swing toward a target did not vary significantly (p >.05). In contrast, the mean interval between saccade onset away from a target and a foot landing on that target (stance onset) did vary significantly (p <.05) under the different experimental conditions. Those results support the stated hypotheses.


Assuntos
Sinais (Psicologia) , Movimentos Oculares/fisiologia , Perna (Membro)/fisiologia , Movimento/fisiologia , Percepção Visual/fisiologia , Humanos , Distribuição Aleatória , Fatores de Tempo
20.
Med Arh ; 55(1 Suppl 1): 5-23, 2001.
Artigo em Servo-Croata (Latino) | MEDLINE | ID: mdl-11795195

RESUMO

Psychiatric services in Bosnia-Herzegovina before the war disaster was fairly developed and one of the best organized services amongst the republics of the former Yugoslavia. The psychiatric care system was based on psychiatric hospitals and small neuropsychiatric wards within general hospitals, accompanied by psychiatric services in health centers. The onset of war in B&H brought devastation and destruction in all domains of life, including the demolition and closing of numerous traditional psychiatric institutions, together with massive psychological suffering of the whole civilian population. Already during the war, and even more so after the war, the reconstruction and reorganization of the mental health services was undertaken. The basis of mental health care for the future is designed as a system where majority of services is located in the community, as close as possible to the habitat of the patients. The key aspect of the system of the comprehensive health care is primary health care and the main role is assigned to family practitioners and mental health professionals working in the community. Large psychiatric institutions were either closed or devastated, or have their capacities extensively reduced. There will be no reconstructions or reopening of the old psychiatric facilities, nor the new ones will be built. The most integrated part of the psychiatric system are the Community based mental health centers. Each of these centers will serve a particular geographic area. The centers will be responsible for prevention and treatment of psychiatric disorders, as well as for the mental health well being. Chronic mental health patients without families and are not able to independently live in the community will be accommodated in designated homes and other forms of protected accommodation within their communities. The principal change in mental health policy in B&H was a decision to transfer psychiatric services from traditional facilities into community, much closer to the patients. Basic elements of the mental health policy in B&H are: Decentralization and sectorization of mental health services; Intersectorial activity; Comprehensiveness of services; Equality in access and utilization of psychiatric service resources; Nationwide accessibility of mental health services; Continuity of services and care, together with the active participation of the community. This overview discusses the primary health care as the basic component of the comprehensive mental health care in greater detail, including tasks for family medicine teams and each individual member. 1. Comprehensive psychiatric care is implemented by primary health care physicians, specialized Centers for community-based mental health care, psychiatric wards of general hospitals and clinical centers in charge of brief, "acute" inpatient care; 2. Primary mental health care is implemented by family practitioners (primary care physicians) and their teams; 3. Specialized psychiatric care in community is performed professional teams specialized mental health issues' within Mental health centers in corresponding sectors; 4. A great deal of relevance is given to development of confidence and utilization of links between primary health care teams and specialized teams in Mental health centers and psychiatric in patient institutions; 5. Psychiatric wards within general cantonal hospitals, departments of psychiatric clinics in Sarajevo, Tuzla, and Mostar, and Cantonal Psychiatric hospital in Sarajevo (Jagomir) shall admit acute patients as well as chronic (with each new relapse). Treatment in these facilities is brief an patients are discharged to return to their homes, with further treatment referral to their family practitioner or designated Mental health center; 6. Chronic mental patients with severe residual impairment in social, psychological, and somatic functioning, shall live in the community with their families or independently. Those chronic patients without families and economic and other resources to live independently shall be placed in supervised Homes in the communities where they live. The above delineated strategy of mental health care program in B&H has several fundamental and specific objectives, among which the most important are: Reduction of incidence and prevalence of some mental disorders, particularly war stress-related disorders and suicide; Reduction of level of functional disability caused by mental disorders through improvement of treatment and care of individuals with mental health problems; Improvement of psychosocial well being of people with mental health problems, through implementation of comprehensive and accessible service for community mental health care; and Respect of basic human rights of individuals with mental health disabilities. The program has been updated since 1996, after the two-year pilot program. The main goals for current two- and five-year period are: Implement the mental health care reform program by launching all 38 Mental health centers in the Federation of BiH by 2002; Complete the 10-day education and re-education of at least 50% of all professionals employed in mental health services in FB&H by 2002; and Achieve that 80 percent of all mental health problems are treated by family medicine teams (primary care practitioners) and specialized mental health services (Community mental health care centers) by 2005.


Assuntos
Reforma dos Serviços de Saúde , Serviços de Saúde Mental/organização & administração , Bósnia e Herzegóvina/epidemiologia , Serviços Comunitários de Saúde Mental/organização & administração , Política de Saúde , Humanos , Transtornos Mentais/epidemiologia , Transtornos Mentais/prevenção & controle , Transtornos Mentais/terapia
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