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1.
Nature ; 578(7796): 568-571, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32103192

RESUMEN

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.
Artículo en Inglés | MEDLINE | ID: mdl-29770439

RESUMEN

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.


Asunto(s)
Lóbulo Frontal/diagnóstico por imagen , Trastornos de la Percepción/diagnóstico por imagen , Trastornos de la Percepción/rehabilitación , Rehabilitación de Accidente Cerebrovascular/métodos , Accidente Cerebrovascular/diagnóstico por imagen , Terapia de Exposición Mediante Realidad Virtual/métodos , Anciano , Anciano de 80 o más Años , Atención/fisiología , Femenino , Lóbulo Frontal/fisiología , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Trastornos de la Percepción/etiología , Proyectos Piloto , Distribución Aleatoria , Accidente Cerebrovascular/complicaciones , Rehabilitación de Accidente Cerebrovascular/tendencias , Resultado del Tratamiento , Terapia de Exposición Mediante Realidad Virtual/tendencias
3.
Acta Neurol Scand ; 135(5): 576-584, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27388230

RESUMEN

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.


Asunto(s)
Velocidad del Flujo Sanguíneo/fisiología , Acueducto del Mesencéfalo/diagnóstico por imagen , Acueducto del Mesencéfalo/fisiología , Líquido Cefalorraquídeo/fisiología , Hidrocéfalo Normotenso/diagnóstico por imagen , Hidrocéfalo Normotenso/fisiopatología , Anciano , Anciano de 80 o más Años , Ventrículos Cerebrales/fisiopatología , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Flujo Pulsátil/fisiología , Estudios Retrospectivos , Método Simple Ciego
4.
Int J Cancer ; 134(9): 2168-79, 2014 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-24122730

RESUMEN

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.


Asunto(s)
Citodiagnóstico/métodos , Neoplasias del Cuello Uterino/diagnóstico , Adulto , Femenino , Humanos , Persona de Mediana Edad , Adulto Joven
5.
J Neurol Neurosurg Psychiatry ; 85(6): 618-24, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24262917

RESUMEN

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.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante/cirugía , Adolescente , Corticoesteroides/administración & dosificación , Adulto , Anciano , Cistitis/diagnóstico , Infecciones por Citomegalovirus/diagnóstico , Infecciones por Virus de Epstein-Barr/diagnóstico , Femenino , Trasplante de Células Madre Hematopoyéticas/métodos , Humanos , Inmunoglobulinas Intravenosas/administración & dosificación , Masculino , Persona de Mediana Edad , Pancreatitis/diagnóstico , Intercambio Plasmático , Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante/fisiopatología , Recurrencia , Reoperación , Estudios Retrospectivos , Suecia , Acondicionamiento Pretrasplante , Trasplante Autólogo , Resultado del Tratamiento
6.
Neurobiol Learn Mem ; 106: 274-82, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24055685

RESUMEN

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.


Asunto(s)
Apolipoproteínas E/genética , Factor Neurotrófico Derivado del Encéfalo/genética , Hemoglobina Glucada/genética , Individualidad , Memoria/fisiología , Polimorfismo de Nucleótido Simple , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Asociación Genética , Humanos , Masculino , Memoria Episódica , Persona de Mediana Edad , Pruebas Neuropsicológicas
7.
Nat Commun ; 13(1): 1138, 2022 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-35241654

RESUMEN

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.


Asunto(s)
Cubierta de Hielo , Agua de Mar , Regiones Antárticas , Estaciones del Año , Agua
8.
AJNR Am J Neuroradiol ; 42(5): 927-929, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33707277

RESUMEN

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.


Asunto(s)
Arteria Carótida Interna/diagnóstico por imagen , Estenosis Carotídea/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
9.
Sci Adv ; 7(15)2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33837074

RESUMEN

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.
Artículo en Inglés | MEDLINE | ID: mdl-21056439

RESUMEN

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.


Asunto(s)
Artritis/epidemiología , Autoevaluación Diagnóstica , Educación en Salud , Población Rural/estadística & datos numéricos , Enfermedad Aguda/epidemiología , Enfermedad Aguda/psicología , Anciano , Artralgia/complicaciones , Artralgia/epidemiología , Artralgia/psicología , Artritis/psicología , Dolor de Espalda/complicaciones , Dolor de Espalda/epidemiología , Dolor de Espalda/psicología , Bangladesh , Femenino , Estado de Salud , Encuestas Epidemiológicas , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa
11.
Leukemia ; 20(1): 42-7, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16327841

RESUMEN

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.


Asunto(s)
Actitud del Personal de Salud , Leucemia Mieloide/tratamiento farmacológico , Selección de Paciente , Enfermedad Aguda , Adolescente , Adulto , Distribución por Edad , Factores de Edad , Anciano , Anciano de 80 o más Años , Estudios de Seguimiento , Humanos , Leucemia Mieloide/mortalidad , Persona de Mediana Edad , Sistema de Registros , Inducción de Remisión , Tasa de Supervivencia , Suecia/epidemiología , Resultado del Tratamiento
12.
Bone Marrow Transplant ; 51(3): 384-90, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26642334

RESUMEN

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.


Asunto(s)
Quimioterapia de Inducción , Neoplasias de Células Germinales y Embrionarias/mortalidad , Neoplasias de Células Germinales y Embrionarias/terapia , Paclitaxel/administración & dosificación , Terapia Recuperativa , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Tasa de Supervivencia , Adulto Joven
13.
Bone Marrow Transplant ; 35(12): 1141-8, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15834433

RESUMEN

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.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Adulto , Anciano , Supervivencia sin Enfermedad , Femenino , Enfermedad Injerto contra Huésped , Efecto Injerto vs Leucemia , Humanos , Masculino , Persona de Mediana Edad , Cromosoma Filadelfia , Probabilidad , Recurrencia , Estudios Retrospectivos , Suecia , Donantes de Tejidos , Trasplante Autólogo , Trasplante Homólogo
14.
Leukemia ; 17(9): 1827-33, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12970783

RESUMEN

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

Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Citarabina/uso terapéutico , Daunorrubicina/uso terapéutico , Factor Estimulante de Colonias de Granulocitos y Macrófagos/uso terapéutico , Leucemia Mieloide/tratamiento farmacológico , Tioguanina/uso terapéutico , Enfermedad Aguda , Adulto , Anciano , Anciano de 80 o más Años , Anemia Refractaria con Exceso de Blastos/tratamiento farmacológico , Anemia Refractaria con Exceso de Blastos/patología , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Transformación Celular Neoplásica , Citarabina/efectos adversos , Daunorrubicina/efectos adversos , Femenino , Estudios de Seguimiento , Factor Estimulante de Colonias de Granulocitos y Macrófagos/administración & dosificación , Humanos , Leucemia Mieloide/patología , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/tratamiento farmacológico , Síndromes Mielodisplásicos/patología , Estudios Prospectivos , Inducción de Remisión , Tasa de Supervivencia , Tioguanina/efectos adversos
15.
AJNR Am J Neuroradiol ; 36(10): 1816-21, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26251434

RESUMEN

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.


Asunto(s)
Encéfalo/irrigación sanguínea , Circulación Cerebrovascular/fisiología , Espectroscopía de Resonancia por Spin del Electrón , Marcadores de Spin , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/fisiología , Femenino , Voluntarios Sanos , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Adulto Joven
16.
Biol Psychiatry ; 45(11): 1472-80, 1999 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-10356630

RESUMEN

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.


Asunto(s)
Anciano de 80 o más Años/fisiología , Ácido Fólico/sangre , Memoria/fisiología , Vitamina B 12/sangre , Anciano , Análisis de Varianza , Estudios Transversales , Femenino , Deficiencia de Ácido Fólico/complicaciones , Humanos , Masculino , Trastornos de la Memoria/sangre , Trastornos de la Memoria/etiología , Recuerdo Mental/fisiología , Valores de Referencia , Muestreo , Deficiencia de Vitamina B 12/complicaciones
17.
Am J Psychiatry ; 157(4): 635-7, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10739428

RESUMEN

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.


Asunto(s)
Trastornos del Conocimiento/fisiopatología , Cuerpo Estriado/química , Dopamina/fisiología , Adulto , Factores de Edad , Trastornos del Conocimiento/metabolismo , Cuerpo Estriado/metabolismo , Dopamina/metabolismo , Humanos
18.
Bone Marrow Transplant ; 32(12): 1119-24, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14647265

RESUMEN

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.


Asunto(s)
Amsacrina/farmacología , Caspasas/farmacología , Citarabina/farmacología , Factor Estimulante de Colonias de Granulocitos/farmacología , Movilización de Célula Madre Hematopoyética/métodos , Leucemia Mieloide/sangre , Enfermedad Aguda , Adulto , Anciano , Amsacrina/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Recuento de Células Sanguíneas , Caspasa 14 , Caspasas/administración & dosificación , Estudios de Cohortes , Terapia Combinada , Citarabina/administración & dosificación , Etopósido/administración & dosificación , Femenino , Filgrastim , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Humanos , Idarrubicina/administración & dosificación , Idarrubicina/efectos adversos , Leucaféresis , Leucemia Mieloide/tratamiento farmacológico , Leucemia Mieloide/terapia , Masculino , Persona de Mediana Edad , Trasplante de Células Madre de Sangre Periférica , Proteínas Recombinantes , Trasplante Autólogo
19.
J Am Geriatr Soc ; 48(11): 1381-8, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11083312

RESUMEN

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.


Asunto(s)
Actividades Cotidianas , Servicios de Salud para Ancianos , Unidades Hospitalarias , Hospitalización/estadística & datos numéricos , Alta del Paciente , Resultado del Tratamiento , Anciano , Anciano de 80 o más Años , Cognición , Femenino , Hospitalización/economía , Humanos , Tiempo de Internación , Masculino , Riesgo
20.
Cancer Genet Cytogenet ; 39(2): 147-52, 1989 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2752368

RESUMEN

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.


Asunto(s)
Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Leucemia Mieloide de Fase Crónica/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Adulto , Crisis Blástica/genética , Crisis Blástica/patología , Aberraciones Cromosómicas , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mieloide de Fase Crónica/tratamiento farmacológico , Leucemia Mieloide de Fase Crónica/genética , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética
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