Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 166
Filtrar
1.
Nature ; 578(7796): 568-571, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32103192

RESUMO

Mass loss from the Antarctic Ice Sheet to the ocean has increased in recent decades, largely because the thinning of its floating ice shelves has allowed the outflow of grounded ice to accelerate1,2. Enhanced basal melting of the ice shelves is thought to be the ultimate driver of change2,3, motivating a recent focus on the processes that control ocean heat transport onto and across the seabed of the Antarctic continental shelf towards the ice4-6. However, the shoreward heat flux typically far exceeds that required to match observed melt rates2,7,8, suggesting that other critical controls exist. Here we show that the depth-independent (barotropic) component of the heat flow towards an ice shelf is blocked by the marked step shape of the ice front, and that only the depth-varying (baroclinic) component, which is typically much smaller, can enter the sub-ice cavity. Our results arise from direct observations of the Getz Ice Shelf system and laboratory experiments on a rotating platform. A similar blocking of the barotropic component may occur in other areas with comparable ice-bathymetry configurations, which may explain why changes in the density structure of the water column have been found to be a better indicator of basal melt rate variability than the heat transported onto the continental shelf9. Representing the step topography of the ice front accurately in models is thus important for simulating ocean heat fluxes and induced melt rates.

2.
Acta Neurol Scand ; 138(4): 284-292, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29770439

RESUMO

OBJECTIVES: A third of patients with stroke acquire spatial neglect associated with poor rehabilitation outcome. New effective rehabilitation interventions are needed. Scanning training combined with multisensory stimulation to enhance the rehabilitation effect is suggested. In accordance, we have designed a virtual-reality based scanning training that combines visual, audio and sensori-motor stimulation called RehAtt® . Effects were shown in behavioural tests and activity of daily living. Here, we use fMRI to evaluate the change in brain activity during Posner's Cuing Task (attention task) after RehAtt® intervention, in patients with chronic neglect. METHODS: Twelve patients (mean age = 72.7 years, SD = 6.1) with chronic neglect (persistent symptoms >6 months) performed the interventions 3 times/wk during 5 weeks, in total 15 hours. Training effects on brain activity were evaluated using fMRI task-evoked responses during the Posner's cuing task before and after the intervention. RESULTS: Patients improved their performance in the Posner fMRI task. In addition, patients increased their task-evoked brain activity after the VR interventions in an extended network including pre-frontal and temporal cortex during attentional cueing, but showed no training effects during target presentations. CONCLUSIONS: The current pilot study demonstrates that a novel multisensory VR intervention has the potential to benefit patients with chronic neglect in respect of behaviour and brain changes. Specifically, the fMRI results show that strategic processes (top-down control during attentional cuing) were enhanced by the intervention. The findings increase knowledge of the plasticity processes underlying positive rehabilitation effects from RehAtt® in chronic neglect.


Assuntos
Lobo Frontal/diagnóstico por imagem , Transtornos da Percepção/diagnóstico por imagem , Transtornos da Percepção/reabilitação , Reabilitação do Acidente Vascular Cerebral/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Terapia de Exposição à Realidade Virtual/métodos , Idoso , Idoso de 80 Anos ou mais , Atenção/fisiologia , Feminino , Lobo Frontal/fisiologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Transtornos da Percepção/etiologia , Projetos Piloto , Distribuição Aleatória , Acidente Vascular Cerebral/complicações , Reabilitação do Acidente Vascular Cerebral/tendências , Resultado do Tratamento , Terapia de Exposição à Realidade Virtual/tendências
3.
Acta Neurol Scand ; 135(5): 576-584, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27388230

RESUMO

OBJECTIVES: Increased aqueduct cerebrospinal fluid (CSF) flow pulsatility and, recently, a reversed CSF flow in the aqueduct have been suggested as hallmarks of idiopathic normal pressure hydrocephalus (INPH). However, these findings have not been adequately confirmed. Our objective was to investigate the flow of blood and CSF in INPH, as compared to healthy elderly, in order to clarify which flow parameters are related to the INPH pathophysiology. MATERIALS AND METHODS: Sixteen INPH patients (73 years) and 35 healthy subjects (72 years) underwent phase-contrast magnetic resonance imaging (MRI). Measurements included aqueduct and cervical CSF flow, total arterial inflow (tCBF; i.e. carotid + vertebral arteries), and internal jugular vein flow. Flow pulsatility, net flow, and flow delays were compared (multiple linear regression, correcting for sex and age). RESULTS: Aqueduct stroke volume was higher in INPH than healthy (148±95 vs 90±50 mL, P<.05). Net aqueduct CSF flow was similar in magnitude and direction. The cervical CSF stroke volume was lower (P<.05). The internal carotid artery net flow was lower in INPH (P<.05), although tCBF was not. No differences were found in internal jugular vein flow or flow delays. CONCLUSIONS: The typical flow of blood and CSF in INPH was mainly characterized by increased CSF pulsatility in the aqueduct and reduced cervical CSF pulsatility. The direction of mean net aqueduct CSF flow was from the third to the fourth ventricle. Our findings may reflect the altered distribution of intracranial CSF volume in INPH, although the causality of these relationships is unclear.


Assuntos
Velocidade do Fluxo Sanguíneo/fisiologia , Aqueduto do Mesencéfalo/diagnóstico por imagem , Aqueduto do Mesencéfalo/fisiologia , Líquido Cefalorraquidiano/fisiologia , Hidrocefalia de Pressão Normal/diagnóstico por imagem , Hidrocefalia de Pressão Normal/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Ventrículos Cerebrais/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Fluxo Pulsátil/fisiologia , Estudos Retrospectivos , Método Simples-Cego
4.
Int J Cancer ; 134(9): 2168-79, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24122730

RESUMO

Little is known about age-dependent variation in outcomes of cervical cytology with modern technologies. This population-based study evaluated age-dependent changes after routine implementation of ThinPrep and SurePath technology in two independent laboratories, and controlled for time trends in a third laboratory using manually read conventional cytology continually. Data were collected from the Danish National Health Care Registers. For each laboratory, we compared proportions of abnormal cytology defined as atypical squamous cells of undetermined significance or worse (ASCUS+) by age and technology phase. The study included 489,960 cytological samples with no recent abnormality from women aged 23-59 years, routinely screened between 1998 and 2007. Implementation of SurePath liquid-based cytology (LBC) was followed by an increase in abnormal cytology in women aged 23-29 years from 4.6 to 6.1%, relative proportion (RP): 1.31 [95% confidence interval (CI): 1.08-1.61], and a decrease in women aged 45-59 years from 2.9 to 2.0%, RP: 0.71 (95% CI: 0.60-0.83). Implementation of ThinPrep LBC was followed by a decrease in abnormal cytology both in women aged 23-29 years from 7.7 to 6.8%, RP: 0.89 (95% CI: 0.78-1.02) and in women aged 45-59 years from 3.4 to 1.0%, RP: 0.30 (95% CI: 0.24-0.37). With implementation of imaging-assisted reading, regardless of the brand of technology, the proportion of abnormality increased by around 30% in all age groups (range from 19 to 41%). In the laboratory with unchanged technology no trends in abnormality proportions were observed. The impact of LBC implementation on cytological abnormality proportions varied considerably across age groups.


Assuntos
Citodiagnóstico/métodos , Neoplasias do Colo do Útero/diagnóstico , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Adulto Jovem
5.
J Neurol Neurosurg Psychiatry ; 85(6): 618-24, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24262917

RESUMO

OBJECTIVE: Only 70-80% of patients with chronic inflammatory demyelinating polyneuropathy (CIDP) respond satisfactorily to the established first-line immunomodulatory treatments. Autologous haematopoietic stem cell transplantation (AHSCT) has been performed as a last treatment resort in a few therapy-refractory cases with CIDP. We describe the results of AHSCT in 11 consecutive Swedish patients with therapy-refractory CIDP with a median follow-up time of 28 months. METHOD: Case data were gathered retrospectively for AHSCT treatments in 11 patients with CIDP refractory to the first-line immunomodulatory treatments, intravenous high-dose immunoglobulin, corticosteroids and plasma exchange and to one or more second-line treatments used in 10 of the 11 patients. RESULTS: The median Inflammatory Neuropathy Cause and Treatment (INCAT) score within 1 month prior to AHSCT was 6 and the Rankin score 4. Total INCAT and Rankin scores improved significantly within 2-6 months after AHSCT and continued to do so at last follow-up. The motor action potential amplitudes (CMAP) improved already within 4 months (median) after AHSCT. Three of the 11 patients relapsed during the follow-up period, requiring retransplantation with AHSCT in one. Eight of the 11 patients maintained drug-free remission upon last follow-up. AHSCT was safe but on the short term associated with a risk of cytomegalovirus (CMV) and Epstein-Barr virus reactivation, CMV disease, haemorrhagic cystitis and pancreatitis. CONCLUSIONS: Our results though hampered by the limited number of patients and the lack of a control group suggest AHSCT to be efficacious in therapy-refractory CIDP, with a manageable complication profile. Confirmation of these results is necessary through randomised controlled trials.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Polirradiculoneuropatia Desmielinizante Inflamatória Crônica/cirurgia , Adolescente , Corticosteroides/administração & dosagem , Adulto , Idoso , Cistite/diagnóstico , Infecções por Citomegalovirus/diagnóstico , Infecções por Vírus Epstein-Barr/diagnóstico , Feminino , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Imunoglobulinas Intravenosas/administração & dosagem , Masculino , Pessoa de Meia-Idade , Pancreatite/diagnóstico , Troca Plasmática , Polirradiculoneuropatia Desmielinizante Inflamatória Crônica/fisiopatologia , Recidiva , Reoperação , Estudos Retrospectivos , Suécia , Condicionamento Pré-Transplante , Transplante Autólogo , Resultado do Tratamento
6.
Neurobiol Learn Mem ; 106: 274-82, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24055685

RESUMO

We aimed at exploring if synergy effects of Brain-Derived Neurotrophic Factor (BDNF) Val(66)Met, Apolipoprotein E (APOE) and HbA1c (glycated haemoglobin) could explain individual differences in memory performance over 10 years in a population based sample of nondemented adults (N=888, 35-85 years at baseline). Episodic memory was affected by such agents, wheras semantic memory was spared. Both age and HbA1c were associated with episodic memory decline. BDNF(66)Met carriers with higher HbA1c levels evidenced slope decline in episodic recall. We found support for joint effects of BDNFVal(66)Met×APOE×HbA1c and BDNFVal(66)Met×APOE×age on rates of episodic memory change over ten years, after controlling for age, sex, education and cardiovascular diseases. We conclude that variants of genetic polymorphisms act in synergy with long-term blood glucose control in shaping patterns of cognitive aging.


Assuntos
Apolipoproteínas E/genética , Fator Neurotrófico Derivado do Encéfalo/genética , Hemoglobinas Glicadas/genética , Individualidade , Memória/fisiologia , Polimorfismo de Nucleotídeo Único , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Estudos de Associação Genética , Humanos , Masculino , Memória Episódica , Pessoa de Meia-Idade , Testes Neuropsicológicos
7.
Nat Commun ; 13(1): 1138, 2022 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-35241654

RESUMO

Recent rapid thinning of West Antarctic ice shelves are believed to be caused by intrusions of warm deep water that induce basal melting and seaward meltwater export. This study uses data from three bottom-mounted mooring arrays to show seasonal variability and local forcing for the currents moving into and out of the Dotson ice shelf cavity. A southward flow of warm, salty water had maximum current velocities along the eastern channel slope, while northward outflows of freshened ice shelf meltwater spread at intermediate depth above the western slope. The inflow correlated with the local ocean surface stress curl. At the western slope, meltwater outflows followed the warm influx along the eastern slope with a ~2-3 month delay. Ocean circulation near Dotson Ice Shelf, affected by sea ice distribution and wind, appears to significantly control the inflow of warm water and subsequent ice shelf melting on seasonal time-scales.


Assuntos
Camada de Gelo , Água do Mar , Regiões Antárticas , Estações do Ano , Água
8.
AJNR Am J Neuroradiol ; 42(5): 927-929, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33707277

RESUMO

Carotid near-occlusion is a frequently overlooked diagnosis when CTA examinations are assessed in routine practice. To evaluate the potential value of phase-contrast MR imaging in identifying near-occlusion, we examined 9 carotid near-occlusions and 20 cases of conventional ≥50% carotid stenosis (mean stenosis degree, 65%) with phase-contrast MR imaging. Mean ICA flow was lower in near-occlusions (52 mL/min) than in conventional ≥50% stenosis (198 mL/min, P < .001). ICA flow of ≤110 mL/min was 100% sensitive and specific for near-occlusion. Phase-contrast MR imaging is a promising tool for diagnosing carotid near-occlusion.


Assuntos
Artéria Carótida Interna/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Sci Adv ; 7(15)2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33837074

RESUMO

Thwaites Glacier is the most rapidly changing outlet of the West Antarctic Ice Sheet and adds large uncertainty to 21st century sea-level rise predictions. Here, we present the first direct observations of ocean temperature, salinity, and oxygen beneath Thwaites Ice Shelf front, collected by an autonomous underwater vehicle. On the basis of these data, pathways and modification of water flowing into the cavity are identified. Deep water underneath the central ice shelf derives from a previously underestimated eastern branch of warm water entering the cavity from Pine Island Bay. Inflow of warm and outflow of melt-enriched waters are identified in two seafloor troughs to the north. Spatial property gradients highlight a previously unknown convergence zone in one trough, where different water masses meet and mix. Our observations show warm water impinging from all sides on pinning points critical to ice-shelf stability, a scenario that may lead to unpinning and retreat.

10.
Public Health ; 124(12): 705-12, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21056439

RESUMO

OBJECTIVES: To examine changes in self-reported arthritis-related illness and self-rated health as a result of a health education intervention, and the association between self-reported arthritis-related illness and self-rated health. STUDY DESIGN: A quasi-experimental study was conducted in eight randomly selected villages in rural Bangladesh (intervention = 4; control = 4). METHODS: The intervention consisted of home-based physical activities, health advice and aspects of healthcare management over 15 months followed by a 3-month latent period. Data were collected before the intervention and after the latent period. Analyses included 839 participants (≥60 years of age) who participated in both surveys. Participants in the intervention area were further categorized into two groups who self-reported compliance or non-compliance with recommended health advice. Self-rated health was assessed using a single global question. Self-reported arthritis-related illness was indicated by the presence of arthritis, back and joint pain, biting sensation, swelling and inflammation in the joints. RESULTS: Hierarchical logistic regression analyses revealed that positive effects on episodes of arthritis-related illness [odds ratio (OR) 1.9, 95% confidence interval (CI) 1.3-2.8] and self-rated health (OR 1.4, 95% CI 1.0-1.9) were more likely among the compliant group compared with the control group. Furthermore, positive self-rated health was more likely among participants reporting a positive change in their arthritis-related illness (OR 2.2, 95% CI 1.5-3.2). The results also showed that literate and non-poor participants were more likely to report positive health, and participants with advancing age were less likely to report positive health. CONCLUSION: Community-based health education is effective in reducing the burden of arthritis-related illness and in enhancing general health in old age.


Assuntos
Artrite/epidemiologia , Autoavaliação Diagnóstica , Educação em Saúde , População Rural/estatística & dados numéricos , Doença Aguda/epidemiologia , Doença Aguda/psicologia , Idoso , Artralgia/complicações , Artralgia/epidemiologia , Artralgia/psicologia , Artrite/psicologia , Dor nas Costas/complicações , Dor nas Costas/epidemiologia , Dor nas Costas/psicologia , Bangladesh , Feminino , Nível de Saúde , Inquéritos Epidemiológicos , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances
11.
Leukemia ; 20(1): 42-7, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16327841

RESUMO

Combination chemotherapy may induce remission from acute myeloid leukemia (AML), but validated criteria for treatment of elderly are lacking. The remission intention (RI) rate for elderly patients, as reported to the Swedish Leukemia Registry, was known to be different when comparing the six health care regions, but the consequences of different management are unknown. The Leukemia Registry, containing 1672 AML patients diagnosed between 1997 and 2001, with 98% coverage and a median follow-up of 4 years, was completed with data from the compulsory cancer and population registries. Among 506 treated and untreated patients aged 70-79 years with AML (non-APL), there was a direct correlation between the RI rate in each health region (range 36-76%) and the two-year overall survival, with no censored observations (6-21%) (chi-squared for trend=11.3, P<0.001; r2=0.86, P<0.02, nonparametric). A 1-month landmark analysis showed significantly better survival in regions with higher RI rates (P=0.003). Differences could not be explained by demographics, and was found in both de novo and secondary leukemias. The 5-year survival of the overall population aged 70-79 years was similar between the regions. Survival of 70-79-year-old AML patients is better in regions where more elderly patients are judged eligible for remission induction.


Assuntos
Atitude do Pessoal de Saúde , Leucemia Mieloide/tratamento farmacológico , Seleção de Pacientes , Doença Aguda , Adolescente , Adulto , Distribuição por Idade , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Seguimentos , Humanos , Leucemia Mieloide/mortalidade , Pessoa de Meia-Idade , Sistema de Registros , Indução de Remissão , Taxa de Sobrevida , Suécia/epidemiologia , Resultado do Tratamento
12.
Bone Marrow Transplant ; 51(3): 384-90, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26642334

RESUMO

Little is known about the prognostic impact of prior paclitaxel therapy and response to induction chemotherapy defined as the regimen preceding high-dose chemotherapy (HDCT) for the salvage therapy of advanced germ cell tumors. Twenty European Society for Blood and Marrow Transplantation centers contributed data on patients treated between 2002 and 2012. Paclitaxel used in either prior lines of therapy or in induction-mobilization regimens was considered. Multivariable Cox analyses of prespecified factors were undertaken on PFS and overall survival (OS). As of October 2013, data for 324 patients had been contributed to this study. One hundred and ninety-two patients (59.3%) had received paclitaxel. Sixty-one patients (19%) had a progression to induction chemotherapy, 234 (72%) a response (29 (9%) missing or granulocyte colony-stimulating factor without chemotherapy). Both progression to induction chemotherapy and prior paclitaxel were significantly associated with shorter OS univariably (P<0.001 and P=0.032). On multivariable analysis from the model with fully available data (N=216) progression to induction was significantly prognostic for PFS and OS (P=0.003), but prior paclitaxel was not (P=0.674 and P=0.739). These results were confirmed after multiple imputation of missing data. Progression to induction chemotherapy could be demonstrated as an independent prognostic factor, in contrast to prior paclitaxel.


Assuntos
Quimioterapia de Indução , Neoplasias Embrionárias de Células Germinativas/mortalidade , Neoplasias Embrionárias de Células Germinativas/terapia , Paclitaxel/administração & dosagem , Terapia de Salvação , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Taxa de Sobrevida , Adulto Jovem
13.
Bone Marrow Transplant ; 35(12): 1141-8, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15834433

RESUMO

Adult patients with acute lymphoblastic leukaemia (ALL) have been treated according to national protocols in Sweden since 1986. Stem cell transplantation (SCT) has been recommended in first remission for patients with risk factors for relapse, and for standard risk patients only after relapse. In this retrospective study, the results of autologous and allogeneic SCT in these populations were evaluated. In total, 187 patients with a median age of 34 years (17-66 years) underwent SCT. The 5-year disease-free survival (DFS), for all patients, was 26% (Confidence intervals (CI) 20-32%). The 5-year DFS was higher for patients transplanted in first remission 32% (CI 24-40%) compared to 14% (CI 5-23%; P<0.0001) in patients transplanted beyond first remission. No significant differences in DFS (P=0.06) were determined between autologous, related donor and unrelated donor SCT in the whole cohort. A lower relapse rate was counterbalanced by higher treatment-related mortality in patients undergoing allogeneic SCT. In Philadelphia-positive ALL, allogeneic SCT was superior to autologous SCT, with a 5-year DFS of 30% (CI 12-47%) vs 0% (P=0.04). Limited chronic graft-versus-host-disease (GVHD) was associated with an improved DFS of 53% (CI 38-69%) compared to no chronic GVHD of 22% (CI 10-36%; P=0.0008), indicating a clinically important graft-versus-leukaemia effect.


Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Adulto , Idoso , Intervalo Livre de Doença , Feminino , Doença Enxerto-Hospedeiro , Efeito Enxerto vs Leucemia , Humanos , Masculino , Pessoa de Meia-Idade , Cromossomo Filadélfia , Probabilidade , Recidiva , Estudos Retrospectivos , Suécia , Doadores de Tecidos , Transplante Autólogo , Transplante Homólogo
14.
Leukemia ; 17(9): 1827-33, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12970783

RESUMO

In this prospective randomized multicenter trial 93 patients, median age 72 years, with RAEB-t (n=25) and myelodysplastic syndrome (MDS)-AML (n=68) were allocated to a standard induction chemotherapy regimen (TAD 2+7) with or without addition of granulocyte-macrophage-CSF (GM-CSF). The overall complete remission (CR) rate was 43% with no difference between the arms. Median survival times for all patients, CR patients, and non-CR patients were 280, 550, and 100 days, respectively, with no difference between the arms. Response rates were significantly better in patients with serum lactate dehydrogenase (S-LDH) levels

Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Citarabina/uso terapêutico , Daunorrubicina/uso terapêutico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Leucemia Mieloide/tratamento farmacológico , Tioguanina/uso terapêutico , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia Refratária com Excesso de Blastos/tratamento farmacológico , Anemia Refratária com Excesso de Blastos/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Transformação Celular Neoplásica , Citarabina/efeitos adversos , Daunorrubicina/efeitos adversos , Feminino , Seguimentos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/administração & dosagem , Humanos , Leucemia Mieloide/patologia , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/patologia , Estudos Prospectivos , Indução de Remissão , Taxa de Sobrevida , Tioguanina/efeitos adversos
15.
AJNR Am J Neuroradiol ; 36(10): 1816-21, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26251434

RESUMO

BACKGROUND AND PURPOSE: The arterial spin-labeling method for CBF assessment is widely available, but its accuracy is not fully established. We investigated the accuracy of a whole-brain arterial spin-labeling technique for assessing the mean parenchymal CBF and the effect of aging in healthy volunteers. Phase-contrast MR imaging was used as the reference method. MATERIALS AND METHODS: Ninety-two healthy volunteers were included: 49 young (age range, 20-30 years) and 43 elderly (age range, 65-80 years). Arterial spin-labeling parenchymal CBF values were averaged over the whole brain to quantify the mean pCBF(ASL) value. Total CBF was assessed with phase-contrast MR imaging as the sum of flows in the internal carotid and vertebral arteries, and subsequent division by brain volume returned the pCBF(PCMRI) value. Accuracy was considered as good as that of the reference method if the systematic difference was less than 5 mL/min/100 g of brain tissue and if the 95% confidence intervals were equal to or better than ±10 mL/min/100 g. RESULTS: pCBF(ASL) correlated to pCBF(PCMRI) (r = 0.73; P < .001). Significant differences were observed between the pCBF(ASL) and pCBF(PCMRI) values in the young (P = .001) and the elderly (P < .001) volunteers. The systematic differences (mean ± 2 standard deviations) were -4 ± 14 mL/min/100 g in the young subjects and 6 ± 12 mL/min/100 g in the elderly subjects. Young subjects showed higher values than the elderly subjects for pCBF(PCMRI) (young, 57 ± 8 mL/min/100 g; elderly, 54 ± 7 mL/min/100 g; P = .05) and pCBF(ASL) (young, 61 ± 10 mL/min/100 g; elderly, 48 ± 10 mL/min/100 g; P < .001). CONCLUSIONS: The limits of agreement were too wide for the arterial spin-labeling method to be considered satisfactorily accurate, whereas the systematic overestimation in the young subjects and underestimation in the elderly subjects were close to acceptable. The age-related decrease in parenchymal CBF was augmented in arterial spin-labeling compared with phase-contrast MR imaging.


Assuntos
Encéfalo/irrigação sanguínea , Circulação Cerebrovascular/fisiologia , Espectroscopia de Ressonância de Spin Eletrônica , Marcadores de Spin , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Feminino , Voluntários Saudáveis , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Adulto Jovem
16.
Biol Psychiatry ; 45(11): 1472-80, 1999 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10356630

RESUMO

BACKGROUND: The relationship between vitamin status and cognitive functioning has been addressed in several recent studies with inconclusive results. The purpose of this study was to examine separate and combined effects of serum vitamin B12 and folic acid on episodic memory functioning in very old age. METHODS: Four study groups were selected from a population-based sample of healthy very old adults (90-101 years of age): normal B12/normal folic acid, low B12/normal folic acid, normal B12/low folic acid, and low B12/low folic acid. Cutoff levels were set at 180 pmol/L for vitamin B12 and at 13 nmol/L for folic acid. Subjects completed two episodic recall tasks (objects and words) and two episodic recognition tasks (faces and words). RESULTS: Neither vitamin affected recognition or primary memory. Most interesting, although B12 was unrelated to recall performance, subjects with low folic acid levels showed impairment in both word recall and object recall. CONCLUSIONS: These results replicate and extend previous findings that folic acid may be more critical than B12 to memory functioning in late life. The selective effects of folic acid on episodic recall were discussed in terms of encoding and retrieval mechanisms, as well as in relation to brain protein synthesis.


Assuntos
Idoso de 80 Anos ou mais/fisiologia , Ácido Fólico/sangue , Memória/fisiologia , Vitamina B 12/sangue , Idoso , Análise de Variância , Estudos Transversais , Feminino , Deficiência de Ácido Fólico/complicações , Humanos , Masculino , Transtornos da Memória/sangue , Transtornos da Memória/etiologia , Rememoração Mental/fisiologia , Valores de Referência , Estudos de Amostragem , Deficiência de Vitamina B 12/complicações
17.
Am J Psychiatry ; 157(4): 635-7, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10739428

RESUMO

OBJECTIVE: The study examined the influence of losses in dopaminergic function on age-related cognitive deficits. METHOD: Eleven healthy subjects (21-68 years of age) completed a set of cognitive tasks used to assess perceptual speed and episodic memory. D(2) receptor binding was measured in the caudate and the putamen by using positron emission tomography. RESULTS: A gradual age-related deterioration was found for all cognitive tasks and for D(2) binding in both striatal structures. Statistical control of D(2) binding eliminated the age-related cognitive variation, whereas residual effects of D(2) binding were seen after the analysis controlled for age. CONCLUSIONS: D(2) receptor binding is a more important factor than chronological age in accounting for variation in cognitive performance across the adult lifespan. Changes in dopaminergic neurotransmission play an important role in aging-related cognitive decline.


Assuntos
Transtornos Cognitivos/fisiopatologia , Corpo Estriado/química , Dopamina/fisiologia , Adulto , Fatores Etários , Transtornos Cognitivos/metabolismo , Corpo Estriado/metabolismo , Dopamina/metabolismo , Humanos
18.
Bone Marrow Transplant ; 32(12): 1119-24, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14647265

RESUMO

We have compared the efficacy of two PBSC mobilisation regimens, mini-ICE+filgrastim (second consolidation) and HiDAC+AMSA+filgrastim (third consolidation), in two consecutive cohorts of patients with AML CR1 receiving treatment according to a joint protocol. Group A: 18 patients, aged 41 (21-65) years, were mobilised with mini-ICE (idarubicin 8 mg/m(2)+cytarabine 800 mg/m(2)+etoposide 150 mg/m(2) days 1-3) followed by filgrastim 300-480 microg once daily s.c. from day 11 after start of chemotherapy. Only four patients reached >5 CD34+ cells/microl blood (B-CD34+) and were able to undergo leukaphereses. Two out of 18 (11%) reached the defined target of >/=2.0 x 10(6) CD34+ cells/kg after 1-3 leukaphereses. Group B: 20 patients, aged 50 (29-67) years, received HiDAC+AMSA (cytarabine 3 g/m(2) b.i.d. days 1, 3, 5+amsacrine 150 mg/m(2) q.d. days 2, 4) followed by filgrastim at a similar dose starting on day 7. A total of 18 patients reached B-CD34+ >5/microl and underwent PBSC harvesting, starting on day 23 (14-29) and yielding 4.0 (0.9-21) x 10(6) CD34+ cells/kg. Of 20 patients, 17 (85%) reached the defined target of >/=2.0 x 10(6) CD34+ cells/kg after 1-3 leukaphereses. We conclude that HiDAC+AMSA+G-CSF - in contrast to mini-ICE+G-CSF - is an efficient regimen for mobilising PBSC in patients with AML CR1.


Assuntos
Amsacrina/farmacologia , Caspases/farmacologia , Citarabina/farmacologia , Fator Estimulador de Colônias de Granulócitos/farmacologia , Mobilização de Células-Tronco Hematopoéticas/métodos , Leucemia Mieloide/sangue , Doença Aguda , Adulto , Idoso , Amsacrina/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Contagem de Células Sanguíneas , Caspase 14 , Caspases/administração & dosagem , Estudos de Coortes , Terapia Combinada , Citarabina/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Filgrastim , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Humanos , Idarubicina/administração & dosagem , Idarubicina/efeitos adversos , Leucaférese , Leucemia Mieloide/tratamento farmacológico , Leucemia Mieloide/terapia , Masculino , Pessoa de Meia-Idade , Transplante de Células-Tronco de Sangue Periférico , Proteínas Recombinantes , Transplante Autólogo
19.
J Am Geriatr Soc ; 48(11): 1381-8, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11083312

RESUMO

BACKGROUND: The effects of residence in an acute geriatrics-based ward (AGW) with emphasis on early rehabilitation and discharge planning for older patients with acute medical illnesses were assessed. Outcome and use of resources were compared with those of patients treated in general medical wards (MWs). A per-protocol rather than intention-to-treat analysis was performed. METHODS: A randomized trial with 3-months follow-up. A total of 190 patients aged 70 years and older were randomized to an acute geriatrics-based ward, and 223 patients were randomized to general medical wards. RESULTS: The two groups were comparable at inclusion. However, after care in the AGW, 71% of patients could be discharged directly home compared with 64% of those treated in MWs (relative risk 1.17; 95% CI, 0.93-1.49). The length of stay was shorter in the AGW (mean 5.9 vs 7.3 days; P = .002). The proportion of patients in geriatric or other hospital wards or in nursing homes did not differ, but the proportion of AGW patients in sheltered living tended to be lower (P = .085). At the follow-up, case fatality, ADL function, psychological well-being, need for daily personal assistance, drug consumption, need for readmission to hospital, and total health care costs after discharge did not differ between the two groups. Poor global outcome was observed in 37% of AGW and 34% of MW patients. CONCLUSIONS: A geriatric approach with greater emphasis on early rehabilitation and discharge planning in the AGW shortened the length of hospital stay and may have reduced the need for long-term institutional living. This occurred despite patients in an acute geriatric ward not having better medical or functional outcome than older acute patients treated in general medical wards.


Assuntos
Atividades Cotidianas , Serviços de Saúde para Idosos , Unidades Hospitalares , Hospitalização/estatística & dados numéricos , Alta do Paciente , Resultado do Tratamento , Idoso , Idoso de 80 Anos ou mais , Cognição , Feminino , Hospitalização/economia , Humanos , Tempo de Internação , Masculino , Risco
20.
Cancer Genet Cytogenet ; 39(2): 147-52, 1989 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2752368

RESUMO

A patient with Philadelphia chromosome (Ph) negative acute lymphoblastic leukemia (ALL, FAB type L1) developed Ph-positive chronic myelogenous leukemia (CML) after more than 2 years in complete remission. Subsequently, Ph-positive lymphoblastic transformation occurred, which was again successfully treated. Thereafter, the CML state was interrupted twice more by blast crisis. The additional chromosomal abnormalities were atypical for Ph-positive CML. The course is interpreted as a possible example of the multistep development of CML. Blastic transformation occurring prior to the Ph chromosome has been reported in only two cases previously.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucemia Mieloide de Fase Crônica/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Adulto , Crise Blástica/genética , Crise Blástica/patologia , Aberrações Cromossômicas , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Leucemia Mieloide de Fase Crônica/genética , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA