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1.
J Surg Case Rep ; 2023(9): rjad522, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37746525

RESUMO

Nonoperative management for hepatic injuries requires observation and supportive care in the case of hemodynamically stable patients. If there is active bleeding on presentation, hepatic artery embolization is an option to achieve hemostasis in the acute setting. Although interventional radiology procedures are well documented in adults, there is limited literature regarding these procedures in the pediatric population. In this report, we present a case of a pediatric patient who sustained blunt abdominal trauma, resulting in a grade IV liver injury. Treatment involved fluoroscopically guided right hepatic segmental arterial gel-foam embolization.

2.
Phys Imaging Radiat Oncol ; 22: 91-97, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35602546

RESUMO

Background and purpose: Poor quality radiotherapy can detrimentally affect outcomes in clinical trials. Our purpose was to explore the potential of knowledge-based planning (KBP) for quality assurance (QA) in clinical trials. Materials and methods: Using 30 in-house post-prostatectomy radiation treatment (PPRT) plans, an iterative KBP model was created according to the multicentre clinical trial protocol, delivering 64 Gy in 32 fractions. KBP was used to replan 137 plans. The KB (knowledge based) plans were evaluated for their ability to fulfil the trial constraints and were compared against their corresponding original treatment plans (OTP). A second analysis between only the 72 inversely planned OTPs (IP-OTPs) and their corresponding KB plans was performed. Results: All dose constraints were met in 100% of KB plans versus 69% of OTPs. KB plans demonstrated significantly less variation in PTV coverage (Mean dose range: KB plans 64.1 Gy-65.1 Gy vs OTP 63.1 Gy-67.3 Gy, p < 0.01). KBP resulted in significantly lower doses to OARs. Rectal V60Gy and V40Gy were 17.7% vs 27.7% (p < 0.01) and 40.5% vs 53.9% (p < 0.01) for KB plans and OTP respectively. Left femoral head (FH) V45Gy and V35Gy were 0.4% vs 7.4% (p < 0.01) and 7.9% vs 34.9% (p < 0.01) respectively. In the second analysis plan improvements were maintained. Conclusions: KBP created high quality PPRT plans using the data from a multicentre clinical trial in a single optimisation. It is a powerful tool for utilisation in clinical trials for patient specific QA, to reduce dose to surrounding OARs and variations in plan quality which could impact on clinical trial outcomes.

3.
J Med Radiat Sci ; 68(4): 364-370, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34310846

RESUMO

INTRODUCTION: This study aimed to develop a single-isocentre volumetric modulated arc therapy (si-VMAT) technique for multiple brain metastases using knowledge-based planning software, comparing it with a multiple-isocentre stereotactic radiosurgery (mi-SRS) planning approach. METHODS: Twenty-six si-VMAT plans were created and uploaded into RapidPlanTM (RP) to create a si-VMAT model. Ten patients, with 2 to 6 metastases (mets), were planned with a si-VMAT technique utilising RP, and a mi-SRS technique on Brainlab iPlan. Paddick Conformity Index (PCI) was used to compare conformity. The volumes of the brain receiving 15Gy, 12Gy, 10Gy, 7.5Gy and 3Gy were also compared. Retrospective treatment times from the last eight patients treated were averaged for pre-imaging and beam on time to calculate treatment times for both techniques. RESULTS: There was a significant difference in the PCI scores for the mi-SRS plans (M = 0.667, SD = 0.114) and si-VMAT plans (M = 0.728, SD = 0.088), with PCI values suggesting better prescription dose conformity with the si-VMAT technique (P = 0.014). Percentage of total brain volume receiving low-dose wash at four of the five different dose levels was significantly less (P < 0.05) with mi-SRS. Average time to treat a single met with current mi-SRS technique is 25.7 min, with each additional met requiring this same amount of time. The average time to treat 2-3 mets using si-VMAT would be 25.3 min and 4+ metastases 33.5 min. CONCLUSION: A knowledge-based si-VMAT approach was efficient in planning and treating multi metastases while achieving clinically acceptable dosimetry with respect to dose conformity and low-dose fall off.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Radioterapia de Intensidade Modulada , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Humanos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Estudos Retrospectivos
4.
J Med Radiat Sci ; 67(4): 310-317, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32881407

RESUMO

INTRODUCTION: RapidPlan (RP), a knowledge-based planning system, aims to consistently improve plan quality and efficiency in radiotherapy. During the early stages of implementation, some of the challenges include knowing how to optimally train a model and how to integrate RP into a department. We discuss our experience with the implementation of RP into our institution. METHODS: We reviewed all patients planned using RP over a 7-month period following inception in our department. Our primary outcome was clinically acceptable plans (used for treatment) with secondary outcomes including model performance and a comparison of efficiency and plan quality between RP and manual planning (MP). RESULTS: Between November 2017 and May 2018, 496 patients were simulated, of which 217 (43.8%) had an available model. RP successfully created a clinically acceptable plan in 87.2% of eligible patients. The individual success of the 24 models ranged from 50% to 100%, with more than 90% success in 15 (62.5%) of the models. In 40% of plans, success was achieved on the 1st optimisation. The overall planning time with RP was reduced by up to 95% compared with MP times. The quality of the RP plans was at least equivalent to historical MP plans in terms of target coverage and organ at risk constraints. CONCLUSION: While initially time-consuming and resource-intensive to implement, plans optimised with RP demonstrate clinically acceptable plan quality, while significantly improving the efficiency of a department, suggesting RP and its application is a highly effective tool in clinical practice.


Assuntos
Planejamento da Radioterapia Assistida por Computador/métodos , Humanos , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada
5.
J Med Radiat Sci ; 67(1): 80-86, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32043819

RESUMO

INTRODUCTION: Differences in knowledge and experience, patient anatomy and tumour location and manipulation of inverse planning objectives and priorities will lead to a variability in the quality of radiation planning. The aim of this study was to investigate whether parotid glands should be treated as separate or combined structures when using knowledge-based planning (KBP) to create oropharyngeal plans, based on the dose they receive. METHOD: Two separate RapidPlan (RP) models were created using the same 70 radical oropharyngeal patients. The 'separated model' divided the parotids into ipsilateral and contralateral structures. The 'combined model' did not separate the parotids. The models were independently validated using 20 patients not included in the models. The same dose constraints and priorities were applied to planning target volumes (PTVs) and organs at risk (OARs) for all plans. An auto-generated line objective and priority was applied in both models, with parotid mean dose and V50 doses evaluated and compared. RESULTS: Plans optimised using the combined model resulted in lower ipsilateral mean doses and lower V50 doses in 80% and 75% of cases, respectively. Fifty-five per cent of plans produced lower mean doses for the contralateral parotid when optimised using the combined model, while lower V50 doses were evenly split between the models. CONCLUSION: Combining the data for both parotids into one RP model resulted in better ipsilateral parotid sparing. Results also suggest that a combined parotid model will spare dose to the contralateral parotid; however, further investigation is required to confirm these results.


Assuntos
Neoplasias Orofaríngeas/diagnóstico por imagem , Orofaringe/diagnóstico por imagem , Glândula Parótida/diagnóstico por imagem , Modelagem Computacional Específica para o Paciente , Planejamento da Radioterapia Assistida por Computador/métodos , Humanos , Órgãos em Risco , Neoplasias Orofaríngeas/radioterapia , Dosagem Radioterapêutica
6.
J Environ Manage ; 210: 263-272, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29367139

RESUMO

While performance assessments of constructed wetlands sites around the world have appraised their capacity for effective removal of organics, a large variance remains in these sites' reported ability to retain nutrients, which appears to depend on differences in design, operation and climate factors. Nutrient retention is a very important objective for constructed wetlands, to avoid eutrophication of aquatic environments receiving their effluents. This study assessed the performance of constructed wetlands in terms of nutrient retention and associated parameters under the humid conditions of Ireland's temperate maritime climate. A review of the performance of 52 constructed wetland sites from 17 local authorities aimed to identify the best performing types of constructed wetlands and the treatment factors determining successful compliance with environmental standards. Data analysis compared effluent results from constructed wetlands with secondary free surface flow or tertiary horizontal subsurface flow, hybrid systems and integrated constructed wetlands with those from small-scale mechanical wastewater treatment plants of the same size class. Nutrient concentrations in effluents of constructed wetlands were negatively correlated (p < .01) with specific area, i.e. the ratio of surface area and population equivalents. The latest generation of integrated constructed wetlands, which had applied design guidelines issued by the Department of the Environment, performed best. Storm management design features improved treatment performance of constructed wetlands significantly (p < .05) for total suspended solids concentrations and exceedance frequency of limit values for total nitrogen. Mechanical wastewater treatment plants, secondary free surface water and tertiary horizontal subsurface flow wetlands showed a very large variance in effluent concentrations for organic and nutrient parameters. E. coli numbers in effluents were lowest for integrated constructed wetlands with an arithmetic mean of 89 MPN/100 ml. Despite Ireland's humid climate, some constructed wetland sites achieved long or frequent periods of zero effluent discharge and thus did not transfer any waterborne pollution to their receptors during these periods.


Assuntos
Eutrofização , Eliminação de Resíduos Líquidos , Áreas Alagadas , Escherichia coli , Irlanda , Nitrogênio , Águas Residuárias , Microbiologia da Água
7.
Obesity (Silver Spring) ; 25(6): 1033-1041, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28452452

RESUMO

OBJECTIVE: To examine the association of program delivery factors with weight loss (WL) in enrollees in iDiet® , a commercial WL program. METHODS: Data were from 644 adults enrolling in an 11-week group WL program and 461 who reported weight to 11 weeks (complete reporters). Predictors of %WL were analyzed using ANCOVA, including meeting type (in-person vs. videoconference), participant type (worksite employees vs. community members), age, gender, BMI, and payment structure. RESULTS: Mean starting BMI was 32.4 ± 7.1 (mean ± SD); WL was 6.1 ± 3.9% in all enrollees in an intention-to-treat analysis and 7.4 ± 3.4% in complete reporters. Videoconference participants, older adults, and enrollees in incentivized programs were more likely to be complete reporters (P < 0.004). %WL at 11 weeks was not associated with gender, starting BMI, or videoconference versus in-person groups. Worksite participants had greater %WL than community participants (+1.2%, P < 0.001), and there was no significant difference in %WL between programs paid by the employee or employer. Greater %WL was achieved by individuals ≥30 versus < 30 years (+2.2%, P < 0.001) and by those enrolling in January-March versus April-June (+1.4%, P = 0.02). CONCLUSIONS: iDiet participants had clinically impactful mean WL. The observed high mean WL in worksites and videoconference-delivered programs broadens options for scalable WL program implementation.


Assuntos
Obesidade/terapia , Telemedicina/estatística & dados numéricos , Comunicação por Videoconferência/estatística & dados numéricos , Redução de Peso/fisiologia , Programas de Redução de Peso/métodos , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Saúde Pública , Local de Trabalho , Adulto Jovem
8.
J Stroke Cerebrovasc Dis ; 21(6): 436-44, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21236699

RESUMO

BACKGROUND: Lipid-lowering medications (LLMs) and especially statin drugs can delay cognitive decline and dementia onset in individuals with and without mild cognitive impairment (MCI) at baseline. METHODS: A longitudinal, observational study was conducted of 3069 cognitively healthy elderly patients (≥75 years of age) who were enrolled in the Ginkgo Evaluation of Memory Study. The primary outcome measure was the time to adjudicated all-cause dementia and Alzheimer dementia (AD). The secondary outcome measure was the change in global cognitive function over time measured by scores from the Modified Mini-Mental State Exam (3MSE) and the cognitive subscale of the AD Assessment Scale (ADAS-Cog). RESULTS: Among participants without MCI at baseline, the current use of statins was consistently associated with a reduced risk of all-cause dementia (hazard ratio [HR], 0.79; 95% confidence interval [95% CI], 0.65-0.96; P = .021) and AD (HR, 0.57; 95% CI, 0.39-0.85; P = .005). In participants who initiated statin therapy, lipophilic statins tended to reduce dementia risk more than nonlipophilic agents. In contrast, there was no significant association between LLM use (including statins), dementia onset, or cognitive decline in individuals with baseline MCI. However, in individuals without MCI at baseline, there was a trend for a neuroprotective effect of statins on cognitive decline. CONCLUSIONS: Statins may slow the rate of cognitive decline and delay the onset of AD and all-cause dementia in cognitively healthy elderly individuals, whereas individuals with MCI may not have comparable cognitive protection from these agents. However, the results from this observational study need to be interpreted with caution and will require confirmation by randomized clinical trials stratifying treatment groups based on MCI status at baseline.


Assuntos
Envelhecimento/psicologia , Doença de Alzheimer/prevenção & controle , Transtornos Cognitivos/prevenção & controle , Cognição/efeitos dos fármacos , Demência/prevenção & controle , Ginkgo biloba , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Memória/efeitos dos fármacos , Nootrópicos/uso terapêutico , Extratos Vegetais/uso terapêutico , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/etiologia , Doença de Alzheimer/psicologia , Análise de Variância , Distribuição de Qui-Quadrado , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/psicologia , Demência/diagnóstico , Demência/etiologia , Demência/psicologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Testes Neuropsicológicos , Modelos de Riscos Proporcionais , Escalas de Graduação Psiquiátrica , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Estados Unidos
9.
Med Gas Res ; 1(1): 4, 2011 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-22146304

RESUMO

This is an editorial for the inauguration of the Medical Gas Research and addresses a particular issue of using hyperbaric oxygen for stroke treatment.

10.
Ann Plast Surg ; 65(2): 124-8, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20585236

RESUMO

The use of absorbable sutures to obtain secure dermal closure in surgeries such as body contouring is common. The risk of complications based on the absorption rate of these materials is unknown. This study attempts to determine whether a faster absorbing suture material such as polyglytone 6211 will lead to fewer complications such as extrusion and granuloma formation as compared with less rapidly absorbing materials such as poliglecaprone 25. Concomitantly, this study also attempts to explore the possible negative outcomes that may be due to faster loss of strength, such as dehiscence and poor scar aesthetics. We found that extrusion occurs less frequently with the rapidly absorbed polyglytone 6211 suture material, without increase in granuloma formation, infection, dehiscence, cellulitis, necrosis, seroma formation, and hematoma formation. We also observed no clinical difference in the cosmetic appearance of scars at the 12-week postoperative follow-up visit.


Assuntos
Técnicas Cosméticas , Dioxanos/uso terapêutico , Poliésteres/uso terapêutico , Suturas , Adulto , Método Duplo-Cego , Estética , Feminino , Humanos , Masculino , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos , Fatores de Risco , Resultado do Tratamento
11.
Harv Bus Rev ; 87(6): 54-61, 113, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19496471

RESUMO

If there's one thing that the past decade's business disasters should teach us, it's that we need to stop evaluating corporate leaders simply on the basis of how much wealth they create for investors. A healthier yardstick would be this: the extent to which leaders create firms that are economically, ethically, and socially sustainable. The first step toward accomplishing that task is to create a culture of candor. Companies can't innovate, respond to stakeholder needs, or run efficiently unless the people inside them have access to timely, relevant information, point out professors O'Toole, of the University of Denver's Daniels College of Business, and Bennis, of the University of Southern California. Increasing transparency can be an uphill battle against human nature, however. The obstacles are numerous: macho executives who don't listen to their subordinates or punish them for bringing bad news; leaders who believe that information is power and hoard it; groupthink among team members who don't know how to disagree; boards that fail to question charismatic CEOs. Nevertheless, leaders can take steps to nurture transparency. By being open and candid, admitting their errors, encouraging employees to speak truth to power, and rewarding contrarians, executives can model the kind of conduct they want to see. Training employees to handle unpleasant conversations with grace also will break down barriers to honest communication. To avoid being blinded by biases, leaders can diversify their sources of information--an obvious measure that's rarely taken. Perhaps the biggest lever for cultural change is the executive selection process--choosing leaders for their transparent behavior, not just their ability to compete. And a few companies have even gone so far as to share all relevant information with every employee.


Assuntos
Cultura Organizacional , Revelação da Verdade , Comércio , Eficiência Organizacional , Estados Unidos
12.
Atherosclerosis ; 200(2): 345-9, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18166191

RESUMO

Methionine (Met) loading increases total plasma homocysteine (tHcy) and assesses homocysteine metabolism. We tested the hypothesis that pre- or post-Met tHcy will predict recurrent stroke or coronary artery disease (CAD) in a subgroup analysis of the Vitamin Intervention for Stroke Prevention (VISP) trial. VISP subjects with non-disabling stroke underwent measurement of tHcy at baseline (fasting pre- and post-Met load) and were randomized to high/low-dose B-vitamin therapy for prevention of recurrent stroke or CAD. In the sample cohort of 2124 subjects, mean+/-S.D. tHcy levels in micromol/l were pre-Met 13.2+/-4.3, post-Met 30.4+/-9.76, and pre/post-Met Delta 17.1+/-8.3. The hazard ratio (HR) for recurrent stroke was 1.16 (p=0.026) for 1 S.D. higher pre-Met tHcy and 1.15 (p=0.054) for 1 S.D. higher post-Met tHcy. For CAD, the HR for 1 S.D. higher pre-Met tHcy was 1.27 (p=0.001) and was 1.00 (p=0.99) for post-Met tHcy. In survival analyses using pre- or post-Met as covariates, the coefficient of pre/post-Met Delta was not significant for stroke and was only marginally significant for CAD (p<0.08), but was negative. We conclude that fasting, pre-Met tHcy is as effective as post-Met tHcy or pre/post-Met Delta in predicting the risk for stroke and CAD.


Assuntos
Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/diagnóstico , Homocisteína/metabolismo , Metionina/farmacologia , Infarto do Miocárdio/terapia , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/diagnóstico , Vitaminas/uso terapêutico , Idoso , Estudos de Coortes , Doença da Artéria Coronariana/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Recidiva , Risco , Acidente Vascular Cerebral/prevenção & controle
13.
Neurology ; 69(22): 2054-62, 2007 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-18040011

RESUMO

OBJECTIVE: To delineate factors associated with cognitive function following stroke and test the hypothesis that vascular risk factors associated with oxidative stress impair recovery. METHOD: We performed a post hoc analysis of the extensive longitudinal database from the 3,680 subjects (over 35 years old) entered between 1996 and 2003 into the Vitamin Intervention for Stroke Prevention trial using a linear mixed effects model. The primary outcome variables were scores on the Mini-Mental State Examination (MMSE) and modified Rankin Scale (mRS). RESULTS: MMSE and mRS gradually improved during the 2-year follow-up period. Increased age and nonwhite race, recurrent stroke, diabetes mellitus, left hemisphere cortical lesions, and values of high-density lipoprotein and homocysteine were independent predictors of less successful cognitive recovery. A strong interaction between homocysteine and age indicated a threshold effect beginning in the late 50s. No vitamin treatment effects were identified. Similar factors were identified for recovery of disability as assessed by the mRS, although there were qualitative and quantitative differences. CONCLUSIONS: The finding that diabetes, high-density lipoprotein, and homocysteine predict poorer cognitive function and greater disability after stroke is consistent with the hypothesis that metabolic stress plays a significant role in the poststroke period.


Assuntos
HDL-Colesterol/metabolismo , Transtornos Cognitivos/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Homocisteína/metabolismo , Acidente Vascular Cerebral/metabolismo , Idoso , Escalas de Graduação Psiquiátrica Breve , Cognição/fisiologia , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/psicologia , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/psicologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Fatores de Risco , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/psicologia
14.
Value Health ; 10(6): 489-97, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17970931

RESUMO

OBJECTIVE: To develop a model to predict stroke-free survival and mortality over a multiyear time frame for a trial-excluded population of medically managed asymptomatic patients with significant carotid artery stenosis. METHODS: We calibrated, validated, and applied a Monte Carlo microsimulation model. For calibration we adjusted general-population mortality and stroke risks to capture these risks specific to asymptomatic carotid stenosis patients. For validation, we compared model-predicted and actual stroke-free survival curves and stroke counts from a population of comparable patients. For application, the validated model predicted stroke-free survival for a hypothetical medically managed arm of a recent single-arm carotid revascularization trial. RESULTS: For each month in the 60-month time frame, the model-predicted and actual calibration trial stroke-free survival curves were not statistically different (P > 0.62). In validation, the calibrated model's stroke-free survival curvematched the actual curve from an independent population; beyond 24 months, the model-predicted and actual curves were not statistically different (P > 0.32). We also compared model-predicted and actual number of strokes from the independent trial. The model predicted 187.25 strokes (95% confidence interval 161.49-213.01), while the actual number was 171.6, within 1.22 standard deviations of the simulated mean. CONCLUSIONS: Given the absence of medically managed populations in recent carotid stenosis trials, our model can estimate stroke-free survival and mortality data for these patients. The model may also estimate the effectiveness of novel medical and procedural therapies for stroke prevention. These effectiveness estimates can inform the development of policies, guidelines, or cost-effectiveness analyses when only single-arm trial data exist.


Assuntos
Estenose das Carótidas/diagnóstico , Simulação por Computador , Indicadores Básicos de Saúde , Acidente Vascular Cerebral/prevenção & controle , Calibragem , Estenose das Carótidas/complicações , Intervalo Livre de Doença , Humanos , Método de Monte Carlo , Prognóstico , Reprodutibilidade dos Testes , Medição de Risco , Acidente Vascular Cerebral/etiologia
15.
Arch Neurol ; 64(8): 1184-8, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17698710

RESUMO

OBJECTIVE: To determine alternative neural pathways for restitution of piano playing after right hemispheric infarction causing left arm and hand paralysis. DESIGN: Case report testing coordinated bimanual skills using structured motor skills tests and neuroimaging. SETTING: A professional pianist sustained a lacunar infarction in the posterior limb of his right internal capsule, which resulted in left hemiparesis with immobilized left-hand and -finger movements persisting for 13 weeks. After 6 months, he had recovered bimanual coordinated piano skills by "ignoring" his left hand while concentrating or discussing subjects other than music while playing. PATIENT: A 63-year-old, male professional pianist. INTERVENTION: Detailed neurological examination including computed cranial tomography, functional magnetic resonance imaging, and positron emission tomography. RESULTS: Functional magnetic resonance imaging activation patterns correlated with rapid movements of fingers in each hand separately and together demonstrating that subcortical and cerebellar pathways were activated during skilled motor function of his left hand. Contralateral cerebral and cerebellar activation occurred with both left- and right-hand movements. During tapping of the left fingers, there was bilateral cerebellar, parietal, and left premotor strip and left thalamic activation. CONCLUSION: Patterns of activation relate to task performance and they are not similar to subjects engaged in simpler tasks such as finger opposition.


Assuntos
Braço , Infarto Cerebral/complicações , Infarto Cerebral/fisiopatologia , Mãos , Hemiplegia/etiologia , Hemiplegia/fisiopatologia , Música , Encéfalo/fisiopatologia , Cerebelo/fisiopatologia , Infarto Cerebral/diagnóstico , Dedos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Destreza Motora , Movimento , Vias Neurais/fisiopatologia , Recuperação de Função Fisiológica
16.
Neuroepidemiology ; 27(4): 222-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17106212

RESUMO

OBJECTIVE: To determine if the stroke risk factor profile of participants in a large, multicenter secondary stroke prevention trial changed over the recruitment period. METHODS: The 3,680 participants in the Vitamin Intervention for Stroke Prevention (VISP) were categorized into four groups by enrollment date. Baseline patient characteristics and stroke risk factors were compared across groups. RESULTS: Hypertension and hypercholesterolemia management improved but prevalence of three major stroke risk factors did not change. Patients enrolled later had better Mini-Mental State and lower NIH Stroke Scale scores, higher multivitamin use, lower prevalence of cortical infarctions, cardiac symptoms and prior stroke, and lower serum creatinine levels. CONCLUSIONS: Those participants enrolled in the later recruitment periods had a different risk factor profile and risk factors were managed differently compared to those enrolled earlier.


Assuntos
Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/prevenção & controle , Vitaminas/uso terapêutico , Adulto , Fatores Etários , Idoso , Índice de Massa Corporal , Infarto Cerebral/epidemiologia , Creatinina/sangue , Diabetes Mellitus/epidemiologia , Suplementos Nutricionais , Feminino , Ácido Fólico/uso terapêutico , Humanos , Hipercolesterolemia/tratamento farmacológico , Hipercolesterolemia/epidemiologia , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fumar/epidemiologia , Triglicerídeos/sangue , Complexo Vitamínico B/uso terapêutico
17.
J Neuroimaging ; 16(3): 252-9, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16808827

RESUMO

BACKGROUND AND PURPOSE: We investigated the diagnostic performance of a brief Power Doppler Imaging (PDI) screening examination for carotid artery stenoses using a newly developed portable instrument. METHODS: A highly experienced sonographer screened in total 152 carotid arteries by either continuous wave (cw) Doppler (n= 50) or a lightweight (2.4 kg) portable duplex device (n= 102) in a prospective study of 76 high-risk patients. The screening protocols included either spectrum analysis and frequency shift measurement in both internal carotid arteries with cw-Doppler or determination of area and diameter ratios in transverse and longitudinal views of both carotid arteries in B-mode and with PDI, but without velocity measurement. Both protocols were evaluated against a complete routine duplex ultrasonography examination. RESULTS: According to the complete examination, stenoses were <50% in 73 of 102 (71.6%), 50-75% in 19 of 102 (18.6%), 75-95% in 7 of 102 (6.9%), and occluded in 3 of 102 (2.9%) arteries (PDI cohort), and <50% in 39 of 50 (78%), 50-75% in 8 of 50 (16%), 75-95% in 2 of 50 (4%), and occluded in 1 of 50 (2%) artery (cw-Doppler cohort). Mean screening time was 8.8 +/- 2.5 minute (PDI) and 9.4 +/- 2.6 minute (cw-Doppler). For stenoses >75%, A(z) values (area under the receiver operating characteristics curve) were 0.897 for area ratios, 0.843 for diameter ratios (PDI protocol) and 1.0 for the cw-Doppler protocol. CONCLUSIONS: The diagnostic performance of the cw-Doppler protocol was superior to the PDI protocol. Nevertheless, both protocols appear suitable as inexpensive screening strategies to identify subjects with >75% stenosis measured by carotid Doppler ultrasound. However, these preliminary data need further verification.


Assuntos
Estenose das Carótidas/diagnóstico por imagem , Ultrassonografia Doppler Dupla/instrumentação , Idoso , Área Sob a Curva , Feminino , Humanos , Masculino , Estudos Prospectivos , Sensibilidade e Especificidade
18.
Neuroepidemiology ; 26(1): 45-51, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16254453

RESUMO

Folic acid fortification of grain products was mandated in the USA by January 1998 and in Canada by November 1998. It was hypothesized that screening total plasma homocysteine levels adjusted for age, sex, race and country that were drawn in stroke patients for the Vitamin Intervention for Stroke Prevention trial from 1997 to 2001 would be steady when fortification was completed. Samples were grouped by years 1997/1998, 1999 and 2000/2001, and adjusted means were calculated using a general linear regression model. In 2,612 US and 1,059 Canadian patients, levels showed no consistent trend in the USA alone, while Canadian levels declined (p = 0.06 overall, 0.0003 in the oldest age group). US levels were 0.39 micromol/l (95% CI: -0.08, 0.85) lower than in Canada. Neither fasting nor time since stroke affected the results.


Assuntos
Ácido Fólico/uso terapêutico , Homocisteína/sangue , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/prevenção & controle , Vitaminas/uso terapêutico , Adulto , Idoso , Canadá/epidemiologia , Jejum/metabolismo , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estados Unidos/epidemiologia
19.
J Stroke Cerebrovasc Dis ; 15(5): 223-7, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17904079

RESUMO

BACKGROUND: To have uniform criteria for evaluating populations for prevalence of transient ischemic attack (TIA)/stroke, validated instruments are necessary for objective assessment and classification. METHODS: Patient responses compatible with symptoms of TIA or ischemic stroke, obtained from participants in a substudy of the Asymptomatic Carotid Atherosclerosis Study, were used to program a neural network for each symptom. Models were designed for rapid classification into 1 of 7 outputs: no event, TIA, or stroke (in left carotid, right carotid, or vertebrobasilar). The networks were then tested by comparing decisions with a validated questionnaire used to access an independent data set of 381 patients. RESULTS: There were 144 patients who reported sudden speech change, 89 with sudden vision loss, 67 with double vision, 189 with sudden numbness, 223 with episodic dizziness, and 108 with paralysis, for a total of 820 reported symptoms among the 381 patients tested. For each category, an equal number of individuals reporting "No" to these phenomena were randomly selected and analyzed. Neural network classification correlated with the diagnoses made by specially trained stroke clinicians (e.g., all who responded "No" were correctly classified as having no neurologic event). Ten symptomatic patients were misclassified, with the most common reason being incomplete data. After adjustment of the network logic, these misclassifications did not recur. CONCLUSION: Computer networks can be trained to produce a rapid and accurate classification of TIA or stroke by vascular distribution, enabling screening of populations for assessment of their incidence and prevalence.

20.
Harv Bus Rev ; 83(5): 96-104, 154, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15929407

RESUMO

Business schools are facing intense criticism for failing to impart useful skills, failing to prepare leaders, failing to instill norms of ethical behavior--and even failing to lead graduates to good corporate jobs. These criticisms come not just from students, employers, and the media but also from deans of some of America's most prestigious B schools. The root cause oftoday's crisis in management education, assert Warren G. Bennis and James O'Toole, is that business schools have adopted an inappropriate--and ultimately self-defeating--model of academic excellence. Instead of measuring themselves in terms of the competence of their graduates, or by how well their faculty members understand important drivers of business performance, they assess themselves almost solely by the rigor of their scientific research. This scientific model is predicated on the faulty assumption that business is an academic discipline like chemistry or geology when, in fact, business is a profession and business schools are professional schools--or should be. Business school deans may claim that their schools remain focused on practice, but they nevertheless hire and promote research-oriented professors who haven't spent time working in companies and are more comfortable teaching methodology than messy, multidisciplinary issues--the very stuff of management. The authors don't advocate a return to the days when business schools were glorified trade schools. But to regain relevancy, they say, business schools must rediscover the practice of business and find a way to balance the dual mission of educating practitioners and creating knowledge through research.


Assuntos
Comércio/educação , Currículo , Educação de Pós-Graduação/métodos , Modelos Educacionais , Universidades/organização & administração , Mobilidade Ocupacional , Comércio/ética , Comércio/organização & administração , Tomada de Decisões , Educação de Pós-Graduação/normas , Humanos , Mentores , Cultura Organizacional , Inovação Organizacional , Competência Profissional , Ciência/métodos , Estados Unidos , Universidades/normas
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