Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
1.
J Autism Dev Disord ; 49(11): 4707, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31468274

RESUMO

During the publication process, an author "M. Pinkett-Davis", who helped conceptualize and revise this study was accidentally excluded from the authorship list. The revised author group is now: Kalb, L., Jacobson, L., Zisman, C., Mahone, E., Landa, R., Azad, G., Pinkett-Davis, M., Menon, D., Singh, V., Zabel, A., & Pritchard, A. Please use this authorship list when citing this manuscript.

2.
J Autism Dev Disord ; 49(9): 3786-3797, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31172337

RESUMO

The goal of this study was to examine caregiver agreement to hear about local research opportunities by joining a clinical research registry. Data from this cross-sectional study were gathered, between 2014 and 2017, across two outpatient clinics: (1) a multidisciplinary Autism Spectrum Disorder (ASD) clinic (N = 5228) and (2) a general psychology clinic serving youth with, or at risk for, a neurodevelopmental disorder (NDD; N = 5040). Overall, more than 8 in 10 caregivers agreed to join the registry. Several child clinical characteristics, as well as racial and sociodemographic factors, were predictive of parental agreement. Findings suggest caregivers of youth with ASD and NDD are amenable to joining the local research enterprise, however further work is needed to understand why some caregivers decline.


Assuntos
Atitude , Transtorno do Espectro Autista/psicologia , Pesquisa Biomédica , Cuidadores/psicologia , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Participação dos Interessados
3.
Evol Comput ; 17(4): 527-44, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19916775

RESUMO

In the field of production engineering, various complex multi-objective problems are known. In this paper we focus on the design of mold temperature control systems, the reconstruction of digitized surfaces, and the optimization of NC paths for the five-axis milling process. For all these applications, efficient problem-specific algorithms exist that only consider a subset of the desirable objectives. In contrast, modern multi-objective evolutionary algorithms are able to cope with many conflicting objectives, but they require a long runtime due to their general applicability. Therefore, we propose hybrid algorithms for the three applications mentioned. In each case, the problem-specific algorithms are used to determine promising initial solutions for the multi-objective evolutionary approach, whose variation concepts are used to generate diversity in the objective space. We show that the combination of these techniques provides great benefits. Since the final solution is chosen by a decision maker based on this Pareto front approximation, appropriate visualizations of the high-dimensional solutions are presented.


Assuntos
Algoritmos , Engenharia/métodos
4.
Br J Radiol ; 76(912): 891-6, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14711777

RESUMO

It has been shown that radiological manifestations of coronary artery sclerosis are an indirect measure of co-morbidity and predictive of survival. The aim of the present study is to evaluate the outcome and side effects after three-dimensional (3D) radiotherapy in patients with unresectable non-small cell lung cancer (NSCLC) stage I, II and IIIA, depending on coronary artery calcification, Karnofsky performance index (KI) and co-morbidity. Between 1993 and 1999, 89 patients with unresectable NSCLC were treated with 3D-radiotherapy. The median age was 66.6 years and median KI 80%. All patients had 3D-treatment planning, based on CT scans. The median total dose was 60 Gy in 2 Gy fractions five times a week. The mean follow-up period was 13.2 months and mean survival time 12.2 months. Significant prognostic factors for improved survival were KI and tumour stage. Patients with a KI<90% had a median survival of 6.5 months compared with 14 months, in patients with KI>/==" BORDER="0">90% (p<0.001). NSCLC stage I+II showed a significantly longer median survival than patients with NSCLC stage IIIA (16.5 months versus 7 months, p<0.004). A significant correlation was seen between pack-years and coronary artery calcification (p<0.05) and between age and marked coronary artery calcification. The incidence of calcification was 67% in smokers (>/==" BORDER="0">20 pack-years) and 43/58 in patients >60 years (p<0.007). Side effects, e.g. pneumonitis, did not correlate with coronary artery calcification but correlated with chronic obstructive lung disease in 19/89 patients. Conventional CT scans for 3D-treatment planning are able to detect coronary artery calcification. There is a significant correlation between age, KI, tobacco consumption and vascular calcification. Although there was a trend to worse overall survival, coronary artery calcification was not a significant predictor of progression-free and overall survival.


Assuntos
Calcinose/etiologia , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Doença da Artéria Coronariana/etiologia , Neoplasias Pulmonares/radioterapia , Radioterapia Conformacional/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Calcinose/diagnóstico por imagem , Doença da Artéria Coronariana/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fumar/efeitos adversos , Análise de Sobrevida , Tomografia Computadorizada por Raios X , Resultado do Tratamento
5.
Br J Radiol ; 75(892): 356-61, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12000695

RESUMO

The purpose of this study was to compare dose distribution of inverse planned intensity modulated radiation therapy (IMRT) with that of conformal radiation therapy (SCRT) in the treatment of esthesioneuroblastoma, and to report initial clinical results. 13 patients with esthesioneuroblastoma were planned both with IMRT and SCRT using complete three-dimensional data sets. A target dose of 60 Gy was prescribed. We performed a detailed dose volume histogram analysis. Dose coverage was equal in both plans while dose distribution was more conformal to the target volume with IMRT. Mean and maximum dose of the brain stem, chiasm, optic nerves and orbits were lower using IMRT than SCRT. The reduction was significant regarding orbit and optic nerve (p<0.05). IMRT was superior in sparing of organs at risk compared with SCRT. The additional sparing by IMRT was positively correlated to the size of the target volume, which was evident with target volumes above 200 cm3. Treatment time was approximately 20 minutes per fraction using IMRT compared with 15 minutes per fraction using SCRT. We conclude that IMRT is both feasible and a valuable tool for more conformal dose distribution in the treatment of esthesioneuroblastoma and to spare organs at risk that are in critical relationship to the tumour. This advantage could be seen especially well in complex shaped target volumes above 200 cm3. Thus, using IMRT, risk of complications may be minimized and local tumour control may be increased.


Assuntos
Estesioneuroblastoma Olfatório/radioterapia , Cavidade Nasal , Neoplasias Nasais/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Seguimentos , Humanos , Nervo Óptico/efeitos da radiação , Órbita/efeitos da radiação , Doses de Radiação , Dosagem Radioterapêutica , Estudos Retrospectivos
6.
Int J Cancer ; 96(6): 341-9, 2001 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-11745504

RESUMO

Integrated boost radiotherapy (IBRT) delivers a higher fraction size to the gross tumor volume and a conventional fraction size to the surrounding tissue of microscopic spread. We compared stereotactic conformal radiotherapy (SCRT) and intensity-modulated radiotherapy (IMRT) with regard to their suitability for IBRT in the treatment of high-grade gliomas. In 20 patients treated with conventional radiotherapy, an additional treatment plan for IBRT [planning target volume (PTV1) defined as contrast-enhancing lesion plus margin due to setup errors 75 Gy, PTV2 defined as edema plus margin due to microscopic spread and setup error 60 Gy] with 7 non-coplanar beams for IMRT and for SCRT was carried out and compared. The part of the PTV2 irradiated with more than 107% of the prescribed dose was 13.9% for IMRT and 30.9% for SCRT (P < 0.001). Dose coverage of PTV2 (volume above 95% of the prescribed dose) was improved with IMRT (88.4% vs. 75.3% with SCRT, P < 0.001). Dose coverage of PTV1 was slightly higher with SCRT (93.7% vs. 87.5% with IMRT), but the conformity to the boost shape was improved by IMRT [conformity index (COIN95) = 0.85 vs. 0.69 with SCRT]. Simultaneously the brain volume irradiated with > 50 Gy was reduced from 60 to 33 cc (P < 0.001). We conclude that IMRT is suitable for local dose escalation in the enhancing lesion and for delivering a homogeneous dose to the PTV2 outside the PTV1 at the same time. Our encouraging results justify application of IMRT for IBRT in the treatment of high-grade gliomas. For clinical evaluation a phase III study has been initiated.


Assuntos
Neoplasias Encefálicas/radioterapia , Glioma/radioterapia , Neoplasias Encefálicas/patologia , Glioma/patologia , Humanos , Dosagem Radioterapêutica
7.
Int J Cancer ; 96(6): 356-62, 2001 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-11745506

RESUMO

Schwannomas are the most common tumors of cranial nerves. Nonacoustic schwannomas are very rare tumors, accounting for approximately 10% of intracranial schwannomas. Standard treatment is complete surgical resection if possible. The role of fractionated stereotactic radiotherapy remains to be defined. Thirteen patients with cranial nonacoustic schwannomas underwent fractionated stereotactic radiotherapy. Seven patients had trigeminal schwannomas, three schwannomas of the lower cranial nerves, and three located in the cerebellopontine angle without involvement of the acoustic nerve. Treatment included primary or adjuvant radiotherapy in progressive disease. Tumor volume ranged from 4.5 to 76.0 cc (median 19.8 cc). Median dose was 57.6 Gy with 1.8 Gy/fraction. Median follow-up was 33 months (range 13-70 months). Local tumor control rate was 100% (13/13). Tumor size remained stable in nine patients and decreased in four. Improvement of preexisting neurological deficits was seen in four cases. No patient developed new cranial nerve or brain stem deficits. No patient showed clinically significant complications of irradiation. Fractionated stereotactic radiotherapy is an effective and well-tolerated noninvasive treatment for cranial nonacoustic schwannomas with excellent tumor control rates. It is an option for patients at higher risk for microsurgical resection or in residual and recurrent tumors.


Assuntos
Neoplasias Encefálicas/radioterapia , Fracionamento da Dose de Radiação , Neurilemoma/radioterapia , Adulto , Idoso , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Radiocirurgia
8.
Invest Radiol ; 34(10): 643-7, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10509242

RESUMO

OBJECTIVE: Abdominal extended field radiotherapy requires exact field shaping. Conventional treatment planning is difficult to adapt to individual anatomy, whereas three-dimensional planning is time-consuming. The authors introduce a method with digitally reconstructed radiographs of spiral CT data to facilitate radiotherapy planning. METHODS: Twenty-two patients underwent imaging with a standardized CT protocol, and digitally reconstructed radiographs were calculated in central beam projection using a maximum intensity projection algorithm (MIP-DRR). For comparison, the expected error from parallel projection was calculated depending on object thickness and field length. RESULTS: The contrast-enhanced protocol used in spiral CT produces a good rendition of all relevant structures. The resulting MIP images have a geometry identical to standard simulation films and to the linear accelerator, whereas standard MIPs with parallel projection show significant distortion compared to the treatment process. CONCLUSIONS: Because of the integration of the geometry of the radiotherapy treatment, the described central beam projection method might be used as a new tool for abdominal radiotherapy planning. The CT protocol offers sufficient contrast enhancement in all relevant structures and provides all necessary anatomic information for individual beam shaping.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Tomografia Computadorizada por Raios X , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intensificação de Imagem Radiográfica/métodos
10.
J Gerontol ; 49(4): M183-8, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8014393

RESUMO

BACKGROUND: Vasopressin has been shown to improve electrophysiological signs of cognitive stimulus processing in young human subjects. This study compared the effects of arginine vasopressin (AVP) on central nervous stimulus processing in old and young mentally healthy subjects. To assess aspects of cognitive stimulus processing, event-related potentials (ERPs) were recorded. METHOD: A total of 22 old and 28 young subjects were tested on two subsequent days. Substances were administered intranasally 22, 12, and 1 hour(s) prior to experimental sessions. Prior to the first session, all subjects received placebo. Prior to the second session, 11 of the elderly and 15 of the young subjects received AVP (3 x 10 IU in each nostril) while the remaining subjects again received placebo. The study was held double blind. The subjects performed an auditory "oddball" task consisting of rare target tones (requiring a button press response) interspersed throughout a sequence of frequent standard tones while an electroencephalogram was recorded. RESULTS: Differences between young and aged subjects were more pronounced for ERPs to targets than standard pips. Latencies of the N2 and P3 waves of the ERP to targets were significantly prolonged, and the P3 amplitude was diminished in the elderly subjects (p < .01). N2 amplitude was enhanced in both age groups by vasopressin (p < .05). However, AVP treatment significantly enlarged the N2-P3 difference amplitude only in young subjects. CONCLUSIONS: The results indicate that AVP improves ERP signs of stimulus processing associated with attentional mechanisms. However, the ERP signs of age-related cognitive impairment remained unimproved after AVP.


Assuntos
Envelhecimento/fisiologia , Arginina Vasopressina/farmacologia , Cognição/efeitos dos fármacos , Potenciais Evocados Auditivos/efeitos dos fármacos , Administração Intranasal , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Arginina Vasopressina/administração & dosagem , Nível de Alerta/efeitos dos fármacos , Nível de Alerta/fisiologia , Atenção/efeitos dos fármacos , Atenção/fisiologia , Cognição/fisiologia , Método Duplo-Cego , Eletroencefalografia/efeitos dos fármacos , Potenciais Evocados Auditivos/fisiologia , Feminino , Humanos , Masculino , Placebos , Tempo de Reação/efeitos dos fármacos , Tempo de Reação/fisiologia
11.
Langenbecks Arch Chir ; 377(1): 19-24, 1992.
Artigo em Alemão | MEDLINE | ID: mdl-1569800

RESUMO

In a three-dimensional anatomical knee joint model all major ligaments were replaced by six nylon fibers and length-pattern changes registered and computed during motion between 0-140 degree. Then anteromedial, posteromedial and intermedial fibers were replaced by an artificial ligament made from Aramid (one to three bundle prothesis) and length changes of the remaining ligaments investigated. The result revealed a dynamic feed-back with characteristic changes in the posterior and collateral ligaments in comparison to the reference. A synthetic replacement using a one bundle prothesis in the isometic tracking led to disapointing results. Best correlations were achieved mimicking the anatomic situation by use of a three bundle prothesis with nearly no changes in the length pattern of the remaining ligaments.


Assuntos
Lesões do Ligamento Cruzado Anterior , Traumatismos do Joelho/cirurgia , Polímeros , Complicações Pós-Operatórias/fisiopatologia , Próteses e Implantes , Ligamento Cruzado Anterior/fisiopatologia , Ligamento Cruzado Anterior/cirurgia , Fenômenos Biomecânicos , Humanos , Traumatismos do Joelho/fisiopatologia , Modelos Anatômicos , Desenho de Prótese
12.
HNO ; 31(4): 140-3, 1983 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-6853231

RESUMO

The symptomatology of Ménièr's disease is delineated by means of 739 cases observed in a period of 25 years. The dilation of the endolymphatic space accompanied by a temporary mixture of endolymph and perilymph substantiates the idea of a nosologic entity as well as the interpretation of the symptoms: vertigo, fluctuating hearing loss, tinnitus, and fullness of the ear. The medical treatment by infusions of Rheomacrodex, vasodilatory substances, antivertiginosa, and psychosedatives is unsatisfying just as surgical treatment by saccotomy, sacculotomy, labyrinthectomy, and other operations at the inner ear. Local application of gentamycin into the middle ear can produce good results; in cases of failure the neurectomy should be taken in consideration. The neurectomy eliminates vertigo, but there remains the need of central compensation and the possibility of appearance of Ménière's disease on the other ear.


Assuntos
Doença de Meniere/diagnóstico , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Doença de Meniere/etiologia , Doença de Meniere/terapia , Pessoa de Meia-Idade , Recidiva , Testes de Função Vestibular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...