103 research outputs found
The carotid and vertebral arteries discovery – initial findings
The studies on the vascular system, including the cervicocephalic arteries (carotid and vertebral arteries), present a long trajectory, having their deep roots in the far past, considering the Western authors, having as representatives the Greek sages Alcmaeon, Diogenes, Hippocrates, Aristoteles, Rufus, and Galenus. They produced pivotal knowledge dissecting mainly cadavers of animals, and established solid bases for the later generations of scholars. The information assembled from these six authors makes it possible to build a quite clear picture of the vascular system, here specifically focused on the cervicocephalic arteries, and mainly of the extracranial segments. Thus, the carotid system became fairly well identified, origin, course, and name, as well as the origin of the still unnamed arteries running through the orifices of the transversal processes of the cervical vertebrae, and entering into the cranium. Almost all that was then known about human anatomy, since this period, and then throughout the Middle Ages, was extrapolated from animal dissections. This state of affairs was maintained until the 14th century, when human corpses dissections were again allowed
The arterial circle described by Willis, and the contribution of his predecessors
The description of arteries at the base of the human brain forming an ‘arterial circle’, named after Thomas Willis, has had a long history after the restoration of human dissection, partly due to the studies of many outstanding anatomists that preceded Willis. He provided, with the collaboration of Richard Lower and Christopher Wren, the first incontestable complete description, as recognized nowadays, accompanied by a superb illustration. Additionally, he presented an explanation for its meaning, indicating for the first time the functional significance of this structure, in health and disease. However, it should be recognized that the initial studies of the arteries of the base of the human brain by Willis’ predecessors, as well as those from ancient times, despite their fragmentary descriptions, were certainly pivotal in paving the way for further and more detailed knowledge of this vascular formatio
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Influence of Leisure Activity on the Incidence of Alzheimer's Disease
OBJECTIVE: To determine whether leisure activities modify the risk for incident dementia. BACKGROUND: Although high educational and occupational attainments have been associated with reduced risk of incident dementia, the relation between leisure activities and dementia risk has not been adequately investigated. METHODS: A total of 1,772 nondemented individuals aged 65 years or older, living in northern Manhattan, New York, were identified and followed longitudinally in a community-based cohort incidence study. Subjects' leisure activities at baseline were assessed, annual examinations with the same standardized neurologic and neuropsychological measures were performed for up to 7 years (mean 2.9 years), and incident dementia was assessed as the main outcome measure. Cox proportional hazards models, adjusting for age, ethnic group, education, and occupation, were used to estimate the relative risk (RR) of incident dementia associated with high leisure activities. RESULTS: Of the 1,772 subjects, 207 became demented. The risk of dementia was decreased in subjects with high leisure activities (RR, 0.62; 95% CI 0.46 to 0.83). The association of high leisure with decreased RR of incident dementia was present even when baseline cognitive performance, health limitations interfering with desired leisure activities, cerebrovascular disease, and depression were considered. CONCLUSIONS: The data suggest that engagement in leisure activities may reduce the risk of incident dementia, possibly by providing a reserve that delays the onset of clinical manifestations of the diseas
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Motor Impairment in PD: Relationship to Incident Dementia and Age
OBJECTIVE: To analyze the relationship of specific motor impairment in idiopathic PD to incident dementia. BACKGROUND: The total Unified PD Rating Scale (UPDRS) motor score at baseline has been associated with an increased risk of developing dementia in PD. METHODS: A cohort of 214 nondemented community-dwelling patients with PD was followed annually with neurologic and neuropsychological evaluations. The association of baseline motor impairment with incident dementia was analyzed using Cox proportional hazards models. Facial expression, tremor, rigidity, and bradykinesia were analyzed as part of subscore A (indicative of dopaminergic deficiency); speech and axial impairment were analyzed as part of subscore B (indicative of predominantly nondopaminergic deficiency). The correlation between the six motor domains and age was also analyzed. RESULTS: Of 173 patients followed for at least 1 year, 50 became demented according to the Diagnostic and Statistical Manual of Mental Disorders, revised 3rd edition (DSM III-R) criteria (mean follow-up, 3.6 +/- 2. 2 years). When both subscores A and B were entered into the Cox model, subscore B was associated with incident dementia (relative risk = 1.19; 95% CI, 1.09 to 1.30; p = 0.0001), in addition to gender, age, and education, whereas subscore A was not (relative risk = 1.03; 95% CI, 0.99 to 1.07; p = 0.19). Of the six motor domains, speech and bradykinesia were associated with incident dementia (p < 0.05), and axial impairment approached significance (p = 0.06). Only axial impairment was correlated with age (correlation coefficient = 0.32; p < 0.001). CONCLUSION: The findings suggest that motor impairment mediated predominantly by nondopaminergic systems is associated with incident dementia in PD. Axial impairment may be the result of a combined effect of the disease and the aging process
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The Association of Incident Dementia with Mortality in PD
Objective: To evaluate the association of incident dementia with mortality in a cohort of patients with idiopathic PD who were nondemented at baseline evaluation, controlling for extrapyramidal sign (EPS) severity at each study visit. Background: The development of dementia has been associated with reduced survival in PD. Because EPS severity is associated with both dementia and mortality in PD, the association of dementia with mortality may be confounded by disease severity. Methods: A cohort of patients with PD was followed annually with neurologic and neuropsychological evaluations. The association of incident dementia and the total Unified PD Rating Scale (UPDRS) motor score with mortality in PD was examined using Cox proportional hazards models with time-dependent covariates. All analyses were adjusted for age at baseline, sex, years of education, ethnicity, and duration of PD. Results: Of 180 PD patients, 41 (22.8%) died during a mean follow-up period of 3.9 ± 2.2 years. Among those who died during the study period, 48.8% (20 of 41) became demented during follow-up, as compared to 23.0% (32 of 139) of those who remained alive. Both incident dementia (RR: 2.2, 95% CI: 1.1 to 4.5, p = 0.04) and the total UPDRS motor score at each study visit (RR: 1.04, 95% CI: 1.02 to 1.07, p = 0.001) were associated with mortality in PD when included in the same Cox model. Conclusions: Incident dementia has an independent effect on mortality when controlling for EPS severity. The development of dementia is associated with a twofold increased mortality risk in PD
Statistical aspects of the TNK-S2B trial of tenecteplase versus alteplase in acute ischemic stroke: an efficient, dose-adaptive, seamless phase II/III design
Background TNK-S2B, an innovative, randomized,
seamless phase II/III trial of tenecteplase versus rt-PA for
acute ischemic stroke, terminated for slow enrollment before regulatory approval
of use of phase II patients in phase III
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Memory and Executive Function Impairment Predict Dementia in Parkinson's Disease
We analyzed the association of neuropsychological test impairment at baseline with the development of dementia in idiopathic Parkinson's disease (PD) patients. A cohort of nondemented PD patients from northern Manhattan, NY was followed annually with neurological and neuropsychological evaluations. The neuropsychological battery included tests of verbal and nonverbal memory, orientation, visuospatial ability, language, and abstract reasoning. The association of baseline neuropsychological tests scores with incident dementia was analyzed using Cox proportional hazards models. The analysis controlled for age, gender, education, duration of PD, and the total Unified Parkinson's Disease Rating Scale motor score at baseline. Forty-five out of 164 patients (27%) became demented during a mean follow-up of 3.7 ± 2.3 years. Four neuropsychological test scores were significantly associated with incident dementia in the Cox model: total immediate recall (RR: 0.92, 95% CI: 0.87–0.97, P = 0.001) and delayed recall (RR: 0.73, 95% CI: 0.59–0.91, P = 0.005) of the Selective Reminding Test (SRT), letter fluency (RR: 0.87, 95% CI: 0.77–0.99, P = 0.03), and Identities and Oddities of the Mattis Dementia Rating Scale (RR: 0.85, 95% CI: 0.73–0.98, P = 0.03). When the analysis was performed excluding patients with a clinical dementia rating of 0.5 (questionable dementia) at baseline evaluation, total immediate recall and delayed recall were still predictive of dementia in PD. Our results indicate that impairment in verbal memory and executive function are associated with the development of dementia in patients with PD
Estudos preliminares sobre a fertilidade dos solos de sequeiros em algumas zonas de Santiago.
A b s t r a c t : D r y l a n d f a r m i n g o n t h e s t e e p s l o p e s o f S a n t i a g o i s c a r a c t e r i z e d a s l o w i n p u t f a r m i n g . E v e r y y e a r t h e
f a r m e r s p r e p a r e a n d c u l t i v a t e t h e i r l a n d s , b u t t h e r e h a s n o t b e e n a n y s t u d y t o i d e n t i f y a n d q u a n t i f y t h e l i m i t i n g
f a c t o r e s c a u s i n g t h e d e c l i n e i n p r o d u c t i o n e v e n i n y e a r s o f g o o d r a i n f a l l . I n 1 9 8 7 , a y e a r o f g o o d r a i n f a l l , o n e
c o u l d i d e n t i f y s m a l l áreas a r o u n d t h e f a r m e r ' s h o u s e s , w h e r e t h e c o r n a n d b e a n s d i d n o t s h o w a n y s i g n o f m i n e -
r a l d i f i c i e n c y O n t h e o t h e r h a n d , t h e d i f i c i e n c y s y m p t o m s b e c a m e m o r e s e v e r e w i t h t h e d i s t a n c e f r o m t h e h o u -
s e s . T h e o b j e c t i v e s o f t h i s s t u d y w e r e t o d e t e r m i n e n u t r i e n t l e v e i s i n t h e s o i l s a n d p l a n t s , a n d t o i d e n t i f y p o s s i b l e
l i m i t i n g f a c t o r s i n t h e d r y l a n d a g r i c u l t u r a T h u s , f i v e r e p r e s e n t a t i v e áreas w e r e c h o s e n i n Ribeira de Faveta a n d
Assomada w i t h d i f f e r e n c e s i n c o r n p l a n t v i g o r a n d s t a n d . S o i l a n d p l a n t s a m p l e s w e r e t a k e n a n d a n a l y s e d f o r
m a c r o e l e m e n t s a n d m i c r o e l e m e n t s i n t h e l a b o r a t o r y . A l s o , p l a n t h e i g h t , p l a n t d e n s i t y , s l o p e , a s p e c t , a n d t h e d i s -
t a n c e a w a y f r o m t h e h o u s e s w e r e m e a s u r e d . R e s u l t s o f s o i l a n d p l a n t a n a l y s i s i d e n t i f i e d P o t a s s i u m a n d P h o s p h o -
r o u s t o b e r e l a t e d w i t h p l a n t h e i g h t
Redução de fósforo em dietas para frangos com base em valores de equivalência da fitase
The objective of this work was to evaluate the use of equivalency values of phytase as a basis for reduction of available phosphorus (aP) in broiler diets. Ten nutritional programs were evaluated with six replicates of 15 birds each. The following were evaluated: performance, tibia ash content, and feed costs. From 1 to 7 and 36 to 42 days of age, the birds received basal diet; from 8 to 21 days, diet without phytase containing 3.9 g kg-1 aP and four diets with phytase containing from 1.1 to 2.5 g kg-1 aP; and from 22 to 35 days, diet without phytase containing 3.4 g kg-1 aP plus diet with phytase containing 1.6 g kg-1 aP. The best nutritional plan was formed by the diets: 4.7 g kg-1 aP without phytase (1 to 7 days); 2.0 g kg-1 aP supplemented with phytase (8 to 21 days); 3.4 g kg-1 aP in feed without phytase (22 to 35 days); and 3.0 g kg-1 aP in feed without phytase (36 to 42 days). The reduction of aP occurs in the period from 8 to 21 days of age and corresponds to 2.0 g kg-1 of feed supplemented with phytase.O objetivo deste trabalho foi avaliar o uso de valores de equivalência da fitase como base para redução de fósforo disponÃvel (P-disp) em dietas para frangos. Foram avaliados dez planos nutricionais com seis repetições de 15 aves cada uma. Avaliaram-se: desempenho, teor de cinzas na tÃbia e custo da ração. De 1 a 7 e de 36 a 42 dias de idade, as aves receberam dieta basal; de 8 a 21 dias, dieta sem fitase contendo 3,9 g kg-1 de P-disp e quatro dietas com fitase contendo de 1,1 a 2,5 g kg-1 de P-disp; e de 22 a 35 dias, dieta sem fitase contendo 3,4 g kg-1 de P-disp mais dieta com fitase contendo 1,6 g kg-1 de P-disp. O melhor plano nutricional foi composto pelas dietas: 4,7 g kg-1 de P-disp sem fitase (1 a 7 dias); 2,0 g kg-1 de P-disp suplementada com fitase (8 a 21 dias); 3,4 g kg-1 de P-disp em ração sem fitase (22 a 35 dias); e 3,0 g kg-1 de P-disp em ração sem fitase (36 a 42 dias). A redução do P-disp ocorre no perÃodo de 8 a 21 dias de idade e corresponde a 2,0 g kg-1 de ração suplementada com fitase
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