Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Neuropathol Appl Neurobiol ; 47(1): 143-156, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32720329

RESUMEN

Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) known as Lewy body dementias have overlapping clinical and neuropathological features. Neuropathology in both includes combination of Lewy body and Alzheimer's disease (AD) pathology. Cerebral amyloid angiopathy (CAA), often seen in AD, is increasingly recognized for its association with dementia. AIMS: This study investigated clinical and neuropathological differences between DLB and PDD. METHODS: 52 PDD and 16 DLB cases from the Queen Square Brain Bank (QSBB) for Neurological disorders were included. Comprehensive clinical data of motor and cognitive features were obtained from medical records. Neuropathological assessment included examination of CAA, Lewy body and AD pathology. RESULTS: CAA was more common in DLB than in PDD (P = 0.003). The severity of CAA was greater in DLB than in PDD (P = 0.009), with significantly higher CAA scores in the parietal lobe (P = 0.043), and the occipital lobe (P = 0.008), in DLB than in PDD. The highest CAA scores were observed in cases with APOE ε4/4 and ε2/4. Survival analysis showed worse prognosis in DLB, as DLB reached each clinical milestone sooner than PDD. Absence of dyskinesia in DLB is linked to the significantly lower lifetime cumulative dose of levodopa in comparison with PDD. CONCLUSIONS: This is the first study which identified prominent concurrent CAA pathology as a pathological substrate of DLB. More prominent CAA and rapid disease progression as measured by clinical milestones distinguish DLB from PDD.


Asunto(s)
Enfermedad de Alzheimer/patología , Demencia/patología , Cuerpos de Lewy/patología , Enfermedad por Cuerpos de Lewy/patología , Anciano , Encéfalo/patología , Angiopatía Amiloide Cerebral/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson/patología
2.
Proc Natl Acad Sci U S A ; 107(38): 16732-7, 2010 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-20807750

RESUMEN

Global demand for agricultural products such as food, feed, and fuel is now a major driver of cropland and pasture expansion across much of the developing world. Whether these new agricultural lands replace forests, degraded forests, or grasslands greatly influences the environmental consequences of expansion. Although the general pattern is known, there still is no definitive quantification of these land-cover changes. Here we analyze the rich, pan-tropical database of classified Landsat scenes created by the Food and Agricultural Organization of the United Nations to examine pathways of agricultural expansion across the major tropical forest regions in the 1980s and 1990s and use this information to highlight the future land conversions that probably will be needed to meet mounting demand for agricultural products. Across the tropics, we find that between 1980 and 2000 more than 55% of new agricultural land came at the expense of intact forests, and another 28% came from disturbed forests. This study underscores the potential consequences of unabated agricultural expansion for forest conservation and carbon emissions.


Asunto(s)
Agricultura , Conservación de los Recursos Naturales , Árboles , Agricultura/historia , Agricultura/tendencias , Conservación de los Recursos Naturales/historia , Conservación de los Recursos Naturales/tendencias , Productos Agrícolas/crecimiento & desarrollo , Productos Agrícolas/historia , Bases de Datos Factuales , Historia del Siglo XX , Historia del Siglo XXI , Clima Tropical , Naciones Unidas
3.
Science ; 293(5530): 657-60, 2001 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-11474103

RESUMEN

Planning and decision-making can be improved by access to reliable forecasts of ecosystem state, ecosystem services, and natural capital. Availability of new data sets, together with progress in computation and statistics, will increase our ability to forecast ecosystem change. An agenda that would lead toward a capacity to produce, evaluate, and communicate forecasts of critical ecosystem services requires a process that engages scientists and decision-makers. Interdisciplinary linkages are necessary because of the climate and societal controls on ecosystems, the feedbacks involving social change, and the decision-making relevance of forecasts.


Asunto(s)
Ecosistema , Predicción , Agricultura , Animales , Toma de Decisiones , Brotes de Enfermedades , Ecología , Epidemiología , Humanos , Formulación de Políticas , Crecimiento Demográfico , Procesos Estocásticos
4.
Biochim Biophys Acta ; 804(1): 68-76, 1984 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-6372867

RESUMEN

Isolated rat adipocytes were incubated with 15 nM [3-3H]glucose or 100 nM [U-14C]glucose with or without insulin and in the absence or presence of unlabelled glucose. Following a 2 h incubation with 15 nM [3-3H]glucose, about two thirds of the cell-associated 3H-labelled metabolic products were hydrophilic largely anionic intermediates and about one third was lipids. The equivalent values were 40 and 60%, respectively, when using 100 nM [U-14C]glucose. The only 14C-labelled metabolite escaping to the incubation medium was 14CO2, which accounted for about 15% of the rate of metabolism. Therefore, the rate of incorporation of 100 nM [U-14C]glucose into the cell-associated metabolites was quite a good measure of its net influx rate. The conversion of the two tracers to the sum of the metabolic products in cells treated with a maximally stimulating insulin concentration remained constant with glucose concentrations up to about 100 microM and then decreased progressively. The incorporation of radioactivity into the different metabolites varied markedly over the glucose concentration range 0-100 microM, presumably due to the saturation of different metabolic pools at different glucose concentrations. This variation was much less in cells not stimulated with insulin. Consequently, the maximal effect of insulin on the incorporation of the tracers into a given metabolite (e.g., labelled lipids) varied over the entire glucose concentration range. In addition, the apparent sensitivity (ED50) with respect to the incorporation into a given metabolite was also dependent on the glucose concentration.


Asunto(s)
Tejido Adiposo/metabolismo , Glucosa/metabolismo , Animales , Transporte Biológico , Células Cultivadas , Relación Dosis-Respuesta a Droga , Insulina/farmacología , Masculino , Ratas , Solubilidad , Agua/metabolismo
5.
Clin Rheumatol ; 3(3): 385-7, 1984 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-6488718

RESUMEN

Two cases are reported of a reactive arthritis due to infection with Yersinia enterocolitica. These are the fifth and sixth cases reported in the United Kingdom. This interesting cause of arthritis may be more common than previously thought and should be considered even in the United Kingdom, although the practical implications are limited.


Asunto(s)
Articulación del Tobillo , Artritis Infecciosa/etiología , Articulación de la Rodilla , Yersiniosis , Adulto , Humanos , Masculino , Yersinia enterocolitica
6.
J Orthop Sports Phys Ther ; 10(7): 254-6, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-18791322

RESUMEN

The purpose of this study was to determine whether the flexible ruler had intertester reliability for the cervical curvature in normal subjects. Measurements of the cervical curvature were taken on 20 subjects in two different positions: with the cervical spine in a neutral position and with the spine in the fully flexed position. The correlation between testers for the neutral position was r = + 0.80, while the intertester reliability for the flexed position was r = + 0.90. Furthermore, paired-data t-tests showed that no significant differences existed between testers for both positions (p > 0.05). The data suggest that the flexible ruler is a reliable measuring tool between testers for the cervical curvature. J Orthop Sports Phys Ther 1989;10(7):254-256.

7.
Cardiovasc Drugs Ther ; 10(4): 403-7, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8924052

RESUMEN

Calcium channel antagonists are among the world's most widely prescribed class of drugs and are used most often in patients with hypertension and coronary artery disease. However, in the recent past serious questions have been raised concerning their potentially detrimental effects. One area of considerable clinical importance that deserves close inspection is the role of calcium channel antagonists following coronary reperfusion. Specifically, is there benefit or detriment?


Asunto(s)
Bloqueadores de los Canales de Calcio/uso terapéutico , Infarto del Miocardio/tratamiento farmacológico , Terapia Trombolítica , Plaquetas/efectos de los fármacos , Bloqueadores de los Canales de Calcio/efectos adversos , Hemorragia/inducido químicamente , Hemostasis/efectos de los fármacos , Humanos , Reperfusión Miocárdica
8.
J Dairy Sci ; 61(10): 1450-6, 1978 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-81841

RESUMEN

Unfermented, frozen colostrum from the first three postpartum milkings of 10 cows was thawed, pooled, and treated to produce three diets: 1) unfermented, 2) fermented (7 days at 25 to 27 C), and 3) fermented (as in 2) with pH adjusted to match that of unfermented colostrum. Eighteen newborn, unsuckled Holstein calves were assigned randomly to one of the three diets. Colostrum diets were thawed and fed at 0, 8, 16, 24, and 36 h. Blood was sampled at 0, 4, 8, 16, 24, and 48 h. Minimal breakdown of colostral gamma-globulin and immunoglobulin G (IgG) occurred during fermentation. Protein breakdown during fermentation was associated primarily with the casein fraction. Concentrations of gamma-globulin in serum of calves receiving unfermented colostrum were higher than those of calves fed fermented colostrum at all sampling times beyond 0 h. Concentrations of gamma-globulin in serum of calves fed buffered colostrum were intermediate. Concentrations of IgG followed a similar trend. Health problems were not encountered, indicating potential for passive immunization of newborn calves via fermented, buffered colostrum in emergency situations.


Asunto(s)
Calostro/metabolismo , Inmunoglobulina A Secretora/metabolismo , Inmunoglobulina A/metabolismo , Proteínas de la Leche/metabolismo , gammaglobulinas/metabolismo , Absorción , Animales , Animales Recién Nacidos , Proteínas Sanguíneas/metabolismo , Tampones (Química) , Bovinos , Calostro/inmunología , Femenino , Fermentación , Congelación , Concentración de Iones de Hidrógeno , Inmunidad Materno-Adquirida , Masculino , Embarazo , Albúmina Sérica/metabolismo , Seroglobulinas/metabolismo
9.
Nature ; 413(6856): 591-6, 2001 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-11595939

RESUMEN

All ecosystems are exposed to gradual changes in climate, nutrient loading, habitat fragmentation or biotic exploitation. Nature is usually assumed to respond to gradual change in a smooth way. However, studies on lakes, coral reefs, oceans, forests and arid lands have shown that smooth change can be interrupted by sudden drastic switches to a contrasting state. Although diverse events can trigger such shifts, recent studies show that a loss of resilience usually paves the way for a switch to an alternative state. This suggests that strategies for sustainable management of such ecosystems should focus on maintaining resilience.


Asunto(s)
Ecosistema , Animales , Cnidarios , Conservación de los Recursos Naturales , Clima Desértico , Agua Dulce , Modelos Biológicos , Océanos y Mares , Procesos Estocásticos , Árboles
10.
Gut ; 32(1): 66-9, 1991 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1899408

RESUMEN

Urinary excretion of orally administered lactulose and 51 chromium labelled ethylenediamine tetra-acetate (51Cr-EDTA) was measured in 12 healthy adult subjects and in six patients with ileostomies to assess intestinal permeability. In normal subjects, 24 hour urinary recovery of 51Cr-EDTA was significantly greater than that of lactulose (mean (SEM) 2.27 (0.15) v 0.50 (0.08)% oral dose; p less than 0.001), but in ileostomy patients recovery of the two markers was the same. In normal subjects, therefore, the difference between the two markers may arise from bacterial break-down of lactulose but not of 51Cr-EDTA in the distal bowel, urinary excretion of lactulose representing small intestinal permeation and that of 51Cr-EDTA representing both small and large intestinal permeation. The markers were then given simultaneously to nine patients receiving non-steroidal anti-inflammatory drugs (NSAIDs) for rheumatoid arthritis and osteoarthritis. The 24 hour urinary recovery of 51Cr-EDTA in the patients was significantly greater than normal (4.64 (1.20) v 2.27 (0.15)% oral dose; p less than 0.01), but that of lactulose was not significantly affected. Moreover, the increase in 51Cr-EDTA recovery was most noticeable in the later urine collections. Both of these findings suggest that NSAIDs may increase colonic permeability.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Colon/metabolismo , Adulto , Anciano , Antiinflamatorios no Esteroideos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/metabolismo , Colon/efectos de los fármacos , Ácido Edético/farmacocinética , Humanos , Lactulosa/farmacocinética , Lactulosa/orina , Persona de Mediana Edad , Osteoartritis/tratamiento farmacológico , Osteoartritis/metabolismo , Permeabilidad/efectos de los fármacos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA