RESUMEN
LOUPE, the Lunar Observatory for Unresolved Polarimetry of the Earth, is a small, robust spectro-polarimeter for observing the Earth as an exoplanet. Detecting Earth-like planets in stellar habitable zones is one of the key challenges of modern exoplanetary science. Characterizing such planets and searching for traces of life requires the direct detection of their signals. LOUPE provides unique spectral flux and polarization data of sunlight reflected by Earth, the only planet known to harbour life. These data will be used to test numerical codes to predict signals of Earth-like exoplanets, to test algorithms that retrieve planet properties, and to fine-tune the design and observational strategies of future space observatories. From the Moon, LOUPE will continuously see the entire Earth, enabling it to monitor the signal changes due to the planet's daily rotation, weather patterns and seasons, across all phase angles. Here, we present both the science case and the technology behind LOUPE's instrumental and mission design. This article is part of a discussion meeting issue 'Astronomy from the Moon: the next decades'.
Asunto(s)
Astronomía/instrumentación , Planeta Tierra , Exobiología/instrumentación , Luna , Planetas , Simulación por Computador , Diseño de Equipo , Evolución Planetaria , Medio Ambiente Extraterrestre , Humanos , Cristales Líquidos , Dispositivos Ópticos , Tecnología de Sensores Remotos/instrumentación , Análisis Espectral/instrumentaciónRESUMEN
BACKGROUND: Anastomotic leakage (AL) remains a severe complication following colorectal surgery, having a negative impact on both short- and long-term outcomes. Since timely detection could enable early intervention, there is a need for the development of novel and accurate, preferably, non-invasive markers. The aim of this study was to investigate whether urinary intestinal fatty acid binding protein (I-FABP) could serve as such a marker. METHODS: This prospective multicenter cross-sectional phase two diagnostic study was conducted at four centers in the Netherlands between March 2015 and November 2016. Urine samples of 15 patients with confirmed colorectal AL and 19 patients without colorectal AL on postoperative day 3 were included. Urinary I-FABP levels were determined using enzyme-linked immunosorbent assays and adjusted for urinary creatinine to compensate for renal dysfunction. RESULTS: Urinary I-FABP levels were significantly elevated in patients with confirmed AL compared to patients without AL on postoperative day 3 (median: 2.570 ng/ml vs 0.809 ng/ml, p = 0.006). The area under the receiver operating characteristics curve (AUROC) was 0.775, yielding a sensitivity of 80% and specificity of 74% at the optimal cutoff point (> 1.589 ng/ml). This difference remained significant after calculation of I-FABP/creatinine ratios (median: 0.564 ng/µmol vs. 0.158 ng/µmol, p = 0.040), with an AUROC of 0.709, sensitivity of 60% and specificity of 90% at the optimal cutoff point (> 0.469 ng/µmol). CONCLUSIONS: Levels of urinary I-FABP and urinary I-FABP/creatinine were significantly elevated in patients with confirmed AL following colorectal surgery, suggesting their potential as a non-invasive biomarker for colorectal anastomotic leakage.
Asunto(s)
Fuga Anastomótica , Neoplasias Colorrectales , Fuga Anastomótica/diagnóstico , Fuga Anastomótica/etiología , Biomarcadores , Estudios Transversales , Proteínas de Unión a Ácidos Grasos , Humanos , Países Bajos , Estudios Prospectivos , Curva ROCRESUMEN
Alzheimer's disease (AD) is associated with progressive endogenous neurotoxicity and hampered inflammatory regulation. The kynurenine (Kyn) pathway, which is controlled by tryptophan 2,3-dioxygenase (TDO), produces neuroactive and anti-inflammatory metabolites. Age-related Kyn pathway activation might contribute to AD pathology in humans, and inhibition of TDO was found to reduce AD-related cellular toxicity and behavioral deficits in animal models. To further explore the effect of aging on the Kyn pathway in the context of AD, we analyzed Kyn metabolite profiles in serum and brain tissue of the APP23 amyloidosis mouse model. We found that aging had genotype-independent effects on Kyn metabolite profiles in serum, cortex, hippocampus and cerebellum, whereas serum concentrations of many Kyn metabolites were reduced in APP23 mice. Next, to further establish the role of TDO in AD-related behavioral deficits, we investigated the effect of long-term pharmacological TDO inhibition on cognitive performance in APP23 mice. Our results indicated that TDO inhibition reversed recognition memory deficits without producing measurable changes in cerebral Kyn metabolites. TDO inhibition did not affect spatial learning and memory or anxiety-related behavior. These data indicate that age-related Kyn pathway activation is not specific for humans and could represent a cross-species phenotype of aging. These data warrant further investigation on the role of peripheral Kyn pathway disturbances and cerebral TDO activity in AD pathophysiology.
RESUMEN
AIM: Inflammatory markers such as serum C-reactive protein (CRP) are used as routine markers to detect anastomotic leakage following colorectal surgery. However, CRP is characterized by a relatively low predictive value, emphasizing the need for the development of novel diagnostic approaches. Volatile organic compounds (VOCs) are gaseous metabolic products deriving from all conceivable bodily excrements and reflect (alterations in) the patient's physical status. Therefore, VOCs are increasingly considered as potential non-invasive diagnostic biomarkers. The aim of this study was to assess the diagnostic accuracy of urinary VOCs for colorectal anastomotic leakage. METHODS: In this explorative multicentre study, urinary VOC profiles of 22 patients with confirmed anastomotic leakage and 27 uneventful control patients following colorectal surgery were analysed by field asymmetric ion mobility spectrometry (FAIMS). RESULTS: Urinary VOCs of patients with anastomotic leakage could be distinguished from those of control patients with high accuracy: area under the receiver operating characteristics curve 0.91 (95% CI 0.81-1.00, P < 0.001), sensitivity 86% and specificity 93%. Serum CRP was significantly increased in patients with a confirmed anastomotic leak but with lower diagnostic accuracy compared to VOC analysis (area under the receiver operating characteristics curve 0.82, 95% CI 0.68-0.95, P < 0.001). Combining VOCs and CRP did not result in a significant improvement of the diagnostic performance compared to VOCs alone. CONCLUSION: Analysis by FAIMS allowed for discrimination between urinary VOC profiles of patients with a confirmed anastomotic leak and control patients following colorectal surgery. A superior accuracy compared to CRP and apparently high specificity was observed, underlining the potential as a non-invasive biomarker for the detection of colorectal anastomotic leakage.
Asunto(s)
Fuga Anastomótica/diagnóstico , Colon/cirugía , Espectrometría de Movilidad Iónica/estadística & datos numéricos , Recto/cirugía , Compuestos Orgánicos Volátiles/orina , Adulto , Anciano , Anciano de 80 o más Años , Anastomosis Quirúrgica/efectos adversos , Biomarcadores/orina , Colostomía/efectos adversos , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Estudios Prospectivos , Curva ROC , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Lower intelligence quotient (IQ) has frequently been reported in patients with schizophrenia. However, it is unclear whether IQ declines (further) after illness onset and what the familial contribution is to this change. Therefore, we investigate IQ changes during the course of illness in patients with non-affective psychosis, their siblings and controls. METHODS: Data are part of the longitudinal Genetic Risk and Outcome of Psychosis (GROUP) study in the Netherlands and Belgium. Participants underwent three measurements, each approximately 3 years apart. A total of 1022 patients with non-affective psychosis [illness duration: 4.34 (s.d. = 4.50) years], 977 of their siblings, and 565 controls had at least one measure of IQ (estimated from four subtests of the WAIS-III). RESULTS: At baseline, IQ was significantly lower in patients (IQ = 97.8) and siblings (IQ = 108.2; p < 0.0001) than in controls (IQ = 113.0; p < 0.0001), and in patients as compared with siblings (p < 0.0001). Over time, IQ increased in all groups. In siblings, improvement in IQ was significantly more pronounced (+0.7 points/year) than in patients (+0.5 points/year; p < 0.0001) and controls (+0.3 points/year; p < 0.0001). IQ increase was not significantly correlated with improvement in (sub)clinical outcome in any of the groups. CONCLUSIONS: During the first 10 years of the illness, IQ increases to a similar (and subtle) extent in a relatively high-functioning group of schizophrenia patients and controls, despite the lower IQ in patients at baseline. In addition, the siblings' IQ was intermediate at baseline, but over time the increase in IQ was more pronounced.
Asunto(s)
Inteligencia , Esquizofrenia/fisiopatología , Hermanos , Adulto , Bélgica , Estudios de Casos y Controles , Femenino , Humanos , Pruebas de Inteligencia , Estudios Longitudinales , Masculino , Países Bajos , Esquizofrenia/genética , Índice de Severidad de la Enfermedad , Adulto JovenRESUMEN
ANK3 encodes AnkyrinG (AnkG), a member of the Ankyrin family that is expressed in several different isoforms in many tissues. A unique serine-rich domain and tail domain in the two largest isoforms of AnkG (270 and 480kDa), restrict AnkG to the axon initial segment and nodes of Ranvier of myelinated neurons. At these sites, AnkG is a master regulator, coordinating the strict clustering of components necessary for proper action potential initiation and propagation along the axon. These components include voltage-gated sodium channels, potassium channels and members of the L1 cell adhesion molecule family. Genetic variation in the ANK3 gene has been linked to a range of neuropsychiatric and neurodevelopmental disorders in human, including schizophrenia, bipolar disorder, intellectual disability and autism spectrum disorders. Here, we study the effect of reduced expression of the large isoforms of Ank3 on cognition and behaviour using a heterozygous knockout mouse model. In three independent behavioural tests, being the open field test, elevated plus maze and social interaction test, we found evidence for increased anxiety in our Ank3 mouse model. Besides, we observed specific neuroanatomical defects in heterozygous knockout mice, including a smaller cingulate cortex, granular retrosplenial cortex, primary motor cortex and fimbria of the hippocampus.
Asunto(s)
Ancirinas/deficiencia , Encéfalo/metabolismo , Encéfalo/patología , Cognición/fisiología , Animales , Ancirinas/genética , Ansiedad/metabolismo , Ansiedad/patología , Modelos Animales de Enfermedad , Heterocigoto , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Actividad Motora/fisiología , Trastornos del Neurodesarrollo/metabolismo , Trastornos del Neurodesarrollo/patología , Trastornos del Neurodesarrollo/psicología , Fenotipo , Isoformas de Proteínas , Filtrado Sensorial/fisiología , Conducta SocialRESUMEN
A 61-year-old woman with decreased consciousness, myoclonus, tremors, nystagmus and bradypnoea, due to cefuroxime-induced neurotoxicity, was admitted to the intensive care unit. Continuous venovenous haemofiltration (CVVH) rapidly reduced plasma cefuroxime concentrations and improved neurological manifestations within the next few hours. Retrospective pharmacokinetic assessment showed a total cefuroxime clearance of 166 ml/min during the CVVH.
Asunto(s)
Antibacterianos/efectos adversos , Cefuroxima/efectos adversos , Hemofiltración/métodos , Síndromes de Neurotoxicidad/terapia , Antibacterianos/sangre , Cefuroxima/sangre , Femenino , Humanos , Unidades de Cuidados Intensivos , Persona de Mediana Edad , Síndromes de Neurotoxicidad/etiología , Resultado del TratamientoRESUMEN
BACKGROUND: Near-infrared imaging with indocyanine green (ICG) has been extensively investigated during laparoscopic cholecystectomy (LC). However, methods vary between studies, especially regarding patient selection, dosage and timing. The aim of this systematic review was to evaluate the potential of the near-infrared imaging technique with ICG to identify biliary structures during LC. METHODS: A comprehensive systematic literature search was performed. Prospective trials examining the use of ICG during LC were included. Primary outcome was biliary tract visualization. Risk of bias was assessed using ROBINS-I. Secondly, a meta-analysis was performed comparing ICG to intraoperative cholangiography (IOC) for identification of biliary structures. GRADE was used to assess the quality of the evidence. RESULTS: Nineteen studies were included. Based upon the pooled data from 13 studies, cystic duct (Lusch et al. in J Endourol 28:261-266, 2014) visualization was 86.5% (95% CI 71.2-96.6%) prior to dissection of Calot's triangle with a 2.5-mg dosage of ICG and 96.5% (95% CI 93.9-98.4%) after dissection. The results were not appreciably different when the dosage was based upon bodyweight. There is moderate quality evidence that the CD is more frequently visualized using ICG than IOC (RR 1.16; 95% CI 1.00-1.35); however, this difference was not statistically significant. CONCLUSION: This systematic review provides equal results for biliary tract visualization with near-infrared imaging with ICG during LC compared to IOC. Near-infrared imaging with ICG has the potential to replace IOC for biliary mapping. However, methods of near-infrared imaging with ICG vary. Future research is necessary for optimization and standardization of the near-infrared ICG technique.
Asunto(s)
Sistema Biliar/diagnóstico por imagen , Colecistectomía Laparoscópica/métodos , Colorantes Fluorescentes , Verde de Indocianina , Espectroscopía Infrarroja Corta , Colangiografía , HumanosRESUMEN
Approaching the theoretically limiting open circuit voltage (Voc) of solar cells is crucial to optimize their photovoltaic performance. Here, we demonstrate experimentally that nanostructured layers can achieve a fundamentally larger Fermi level splitting, and thus a larger Voc, than planar layers. By etching tapered nanowires from planar indium phosphide (InP), we directly compare planar and nanophotonic geometries with the exact same material quality. We show that the external radiative efficiency of the nanostructured layer at 1 sun is increased by a factor 14 compared to the planar layer, leading to a 70 mV enhancement in Voc. The higher voltage arises from both the enhanced outcoupling of photons, which promotes radiative recombination, and the lower active material volume, which reduces bulk recombination. These effects are generic and promise to enhance the efficiency of current record planar solar cells made from other materials as well.
RESUMEN
BACKGROUND: Influenza vaccination of healthcare workers (HCWs) is recommended to prevent the transmission of influenza to vulnerable patients. Nevertheless, vaccination coverage rates of HCWs in European countries have been low. AIM: To investigate the relative and combined strength of sociocognitive variables, from past research, theory and a qualitative study, in explaining the motivation of HCWs to receive the influenza vaccine. METHODS: An anonymous, online questionnaire was distributed among HCWs in hospital settings in Belgium, Germany and the Netherlands between February and April 2013. FINDINGS: Attitude and past vaccination uptake explained a considerable amount of variance in the intention of HCWs to receive the influenza vaccine. Moreover, low perceived social norms, omission bias, low moral norms, being older, having no patient contact, and being Belgian or Dutch (compared with German) increased the probability of having no intention to receive the influenza vaccine compared with being undecided about vaccination. High intention to receive the influenza vaccine was shown to be more likely than being undecided about vaccination when HCWs had high perceived susceptibility of contracting influenza, low naturalistic views, and lower motivation to receive the vaccine solely for self-protection. CONCLUSION: Country-specific interventions and a focus on different sociocognitive variables depending on the intention/lack of intention of HCWs to receive the influenza vaccine may be beneficial to promote vaccination uptake.
Asunto(s)
Personal de Salud/psicología , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/prevención & control , Vacunación/psicología , Adulto , Actitud del Personal de Salud , Bélgica , Cognición , Estudios Transversales , Femenino , Alemania , Conocimientos, Actitudes y Práctica en Salud , Hospitales , Humanos , Gripe Humana/psicología , Intención , Masculino , Persona de Mediana Edad , Países Bajos , Encuestas y Cuestionarios , Adulto JovenRESUMEN
BACKGROUND: The association between childhood trauma and psychotic and depressive symptomatology is well established. However, less is known about the specificity and course of these symptoms in relation to childhood trauma. METHOD: In a large sample (n = 2765) of patients with psychosis (n = 1119), their siblings (n = 1057) and controls (n = 589), multivariate (mixed-effects) regression analyses with multiple outcomes were performed to examine the association between childhood trauma and psychotic and depressive symptomatology over a 3-year period. RESULTS: A dose-response relationship was found between childhood trauma and psychosis. Abuse was more strongly associated with positive symptoms than with negative symptoms whereas the strength of the associations between neglect and positive and negative symptoms was comparable. In patients, similar associations between childhood trauma and psychotic or depressive symptoms were found, and in siblings and controls, stronger associations were found between trauma and depressive symptomatology. Childhood trauma was not related to a differential course of symptoms over a 3-year time period. CONCLUSIONS: In congruence with earlier work, our findings suggest that childhood trauma, and abuse in particular, is associated with (subthreshold) psychosis. However, childhood trauma does not seem to be associated with a differential course of symptoms, nor does it uniquely heighten the chance of developing (subthreshold) psychotic symptomatology. Our results indicate that trauma may instead contribute to a shared vulnerability for psychotic and depressive symptoms.
Asunto(s)
Maltrato a los Niños/psicología , Depresión/psicología , Progresión de la Enfermedad , Trastornos Psicóticos/psicología , Adulto , Niño , Maltrato a los Niños/estadística & datos numéricos , Depresión/epidemiología , Depresión/etiología , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Países Bajos , Trastornos Psicóticos/epidemiología , Trastornos Psicóticos/etiología , Factores de Riesgo , HermanosRESUMEN
PURPOSE: The association between childhood maltreatment (ChM) and psychotic disorders is well established. However, there is an ongoing debate about which factors account for this relationship. One explanation is that the relationship between ChM and psychosis is mediated by adult attachment style. Therefore, in this study, we aimed to investigate whether adult attachment style mediates the relationship between ChM and positive and negative symptomatology. METHODS: We investigated the relation between ChM and psychotic symptoms, taking into account levels of (insecure) attachment, in 131 patients with psychotic illness, 123 siblings and 72 controls. ChM was assessed with the Childhood Trauma Questionnaire (CTQ). Attachment dimensions of anxiety and avoidance were measured using the Psychosis Attachment Measure (PAM). RESULTS: In both patients and siblings, ChM predicted positive symptoms and this relationship was partly mediated by attachment style. This relationship was found to be stronger for siblings than for patients. ChM predicted negative symptoms in patients and siblings. In the patient sample, attachment style did not mediate the relationship between ChM and negative symptoms, whereas attachment style was found to be a mediator in the sibling sample. CONCLUSIONS: ChM was associated with positive and negative symptomatology in both patients and siblings. Particularly in siblings, the relationship between ChM and psychosis seems to be mediated by adult attachment style. Perhaps attachment style may play a more prominent role on a subclinical level.
Asunto(s)
Adultos Sobrevivientes del Maltrato a los Niños/psicología , Ansiedad/diagnóstico , Apego a Objetos , Trastornos Psicóticos/diagnóstico , Hermanos/psicología , Adulto , Ansiedad/genética , Ansiedad/psicología , Femenino , Humanos , Masculino , Escalas de Valoración Psiquiátrica , Trastornos Psicóticos/genética , Trastornos Psicóticos/psicología , Encuestas y Cuestionarios , Adulto JovenAsunto(s)
Endoscopía/métodos , Hernia Inguinal/cirugía , Herniorrafia/métodos , Profilaxis Antibiótica , Costos y Análisis de Costo , Endoscopía/efectos adversos , Endoscopía/economía , Femenino , Hernia Inguinal/diagnóstico , Hernia Inguinal/etiología , Herniorrafia/efectos adversos , Herniorrafia/economía , Humanos , Laparoscopía/efectos adversos , Laparoscopía/economía , Laparoscopía/métodos , Masculino , Complicaciones Posoperatorias , Recurrencia , Reoperación , Factores de Riesgo , Mallas QuirúrgicasRESUMEN
BACKGROUND: Approximately 11% of schoolchildren are bullied on a regular basis. It has been argued that continuous exposure to stress is related to the development of psychotic symptoms. The current study sought to investigate whether being bullied in childhood is related to the development of psychotic symptoms. METHOD: A search of PubMed, PsycINFO and EMBASE was conducted. The reference lists of included papers were searched to identify other eligible papers. A meta-analysis was performed on a subgroup of studies. RESULTS: We found four clinical and 10 general population studies that met inclusion criteria. The results of the clinical studies were mixed. However, the results of the non-clinical studies provided more consistent evidence that school bullying is related to the development of non-clinical psychotic symptoms. Stronger associations were found with increased frequency and severity and longer duration of being bullied. We performed a meta-analysis on seven population-based studies, yielding unadjusted and adjusted odds ratios (ORs) of 2.7 [95% confidence interval (CI) 2.1-3.6] and 2.3 (95% CI 1.5-3.4) respectively. CONCLUSIONS: Although there is some evidence of an association between bullying and psychosis in clinical samples, the research is too sparse to draw any firm conclusions. However, population-based non-clinical studies support the role of bullying in the development of psychotic symptoms later in life. These findings are consistent with findings of an increased risk of psychotic symptoms among those exposed to other types of abuse.
Asunto(s)
Acoso Escolar/psicología , Desarrollo de la Personalidad , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/psicología , Adolescente , Adulto , Niño , Víctimas de Crimen/psicología , Femenino , Humanos , Masculino , Modelos Teóricos , Trastornos Psicóticos/epidemiología , Factores de Riesgo , Estadística como Asunto , Adulto JovenRESUMEN
A 25-year-old male developed sinus tachycardia after given clozapine for treatment-resistant psychosis in schizophrenia. The tachycardia was treated successfully with propranolol for several weeks. The patient developed skin eruptions, later diagnosed as psoriasis. Propranolol is known to be capable of causing, evoking or aggravating psoriasis. Several other drugs commonly used in psychiatric practice are also known to cause psoriasis. Doctors need to be aware to the possible side effects of such drugs because they can jeopardise the patient's wellbeing and reduce the efficacy of psychiatric treatment.
Asunto(s)
Clozapina/efectos adversos , Propranolol/efectos adversos , Propranolol/uso terapéutico , Psoriasis/inducido químicamente , Taquicardia/inducido químicamente , Taquicardia/tratamiento farmacológico , Antagonistas Adrenérgicos beta/efectos adversos , Antagonistas Adrenérgicos beta/uso terapéutico , Adulto , Antipsicóticos/efectos adversos , Antipsicóticos/uso terapéutico , Clozapina/uso terapéutico , Humanos , Masculino , Trastornos Psicóticos/tratamiento farmacológico , Trastornos Psicóticos/etiología , Esquizofrenia/complicaciones , Esquizofrenia/tratamiento farmacológicoRESUMEN
During surgery, a surgeon relies on the vision of his eyes and the touch of his hands. While laparoscopic surgery for colon cancer has proven to be safe and effective, it still remains a technically difficult procedure. Although it is associated with reduced haptic feedback, by enforcing the power of visual guidance, the loss of this feedback can be (partly) compensated for. Here we describe how the use of near-infrared dyes and fluorescence laparoscopy could help improve tumour staging and therefore lead to better selection of patients for postoperative adjuvant chemotherapy. More controversially, and analogous to melanoma and breast cancer surgery with sentinel node biopsy, we speculate that local resection with SLN harvesting in early colon cancer might change the therapeutic and surgical strategy in colon cancer.
Asunto(s)
Neoplasias del Colon/patología , Colorantes Fluorescentes , Verde de Indocianina , Ganglios Linfáticos/patología , Espectroscopía Infrarroja Corta , Neoplasias del Colon/cirugía , Colorantes , Fluorescencia , Humanos , Laparoscopía , Metástasis Linfática , Micrometástasis de Neoplasia/diagnóstico , Estadificación de Neoplasias , Colorantes de Rosanilina , Biopsia del Ganglio Linfático CentinelaRESUMEN
OBJECTIVE: To analyse the prevalence and incidence of dementia in a population of community-dwelling elderly (aged 75-80), living in socio-economically differing districts of Antwerp (Belgium), taking into account possible gender and educational differences. METHODS: A longitudinal cohort study (N=825) with a 3-year follow-up period (N=363). The Mini Mental State Examination (MMSE) was used as a primary screen of cognitive functioning. Scoring 21 or below led to a second phase examination by a neurologist, including the CAMDEX-R-N and a neurological examination, to provide a tentative aetiological diagnosis of dementia. These procedures were conducted annually during a 3-year follow-up period. RESULTS: In accordance with international literature, the overall prevalence rate of dementia was 8.7%. The cumulative incidence rate (IR) of dementia was 36.60 per 1000Py with annual IRs ranging from 34.39 over 35.16 to 49.04 per 1000Py. Dementia of the Alzheimer type (DAT) was the most occurring prevalent and incident cause. Women appeared to be at higher risk and the occurrence of cognitive deterioration was more prominent in districts with lower socio-economic status, possibly related to a lower education level. CONCLUSION: We demonstrate dementia is a considerable health problem in an urban Belgian population of community-dwelling elderly aged between 75 and 80 years old. In order to prepare health care and social security systems for the future management of dementia, proper epidemiological insight into the current and future magnitude of the burden of dementia, taking into account socio-economic differences, to which this study contributes, are required.
Asunto(s)
Cognición/fisiología , Demencia/epidemiología , Demencia/psicología , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/epidemiología , Bélgica/epidemiología , Trastornos del Conocimiento/epidemiología , Interpretación Estadística de Datos , Escolaridad , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Masculino , Estado Civil , Examen Neurológico , Pruebas Neuropsicológicas , Factores Sexuales , Factores SocioeconómicosRESUMEN
A simple and fast HPLC method based on an isocratic, reversed-phased ion-pair with amperometric end-point detection for simultaneous measurement of noradrenergic (MHPG/NA and A), dopaminergic (DOPAC, HVA/DA) and serotonergic (5-HIAA/5-HT) compounds in mouse brain tissue was developed. In order to improve the chromatographic resolution (Rs) with an acceptable total analysis time, experimental designs for multivariate optimization of the experimental conditions were applied. The optimal conditions for the separation of the eight neurotransmitters and metabolites, as well as two internal standards, i.e., DHBA and 5-HMT, were obtained using a mixture of methanol-phosphate-citric buffer (pH 3.2, 50 mM) (9:91, v/v) containing 2 mM OSA as mobile phase at 32°C on a microbore ALF-115 column (150 mm × 1.0 mm, 3 µm particle size) filled with porous C(18) silica stationary phase. In this study, a two-level fractional factorial experimental design (½ 2(K)) was employed to optimize the separation and capacity factor (k') of each molecule, leading to a good separation of all biogenic amines and their metabolites in brain tissue. A simple method for the preparation of different bio-analytical samples in phosphate-citric buffer was also developed. Results show that all molecules of interest were stabilized for at least 24 h in the matrix conditions without any antioxidants. The method was fully validated according to the requirements of SFSTP (Société Française des Sciences et Techniques Pharmaceutiques). The acceptance limits were set at ±15% of the nominal concentration. The method was found accurate over a concentration range of 4-2000 ng/ml for MHPG, 1-450 ng/ml for NA, 1-700 ng/ml for A, 1-300 ng/ml for DOPAC, 1-300 ng/ml for 5-HIAA, 1-700 ng/ml for DA, 4-2800 ng/ml for HVA and 1-350 ng/ml for 5-HT. The assay limits of detection for MHPG, NA, A, DOPAC, 5-HIAA, DA, HVA and 5-HT were 2.6, 2.8, 4.1, 0.7, 0.6, 0.8, 4.2 and 1.4 pg, respectively. It was found that the mean inter- and intra-assay relative standard deviations (RSDs) over the range of standard curve were less than 3%, the absolute and the relative recoveries were around 100%, demonstrating the high precision and accuracy, and reliability of the analytical method described to apply in routine analysis of biogenic amines and their metabolites in brain tissue.
Asunto(s)
Aminas Biogénicas/análisis , Aminas Biogénicas/metabolismo , Química Encefálica , Encéfalo/metabolismo , Cromatografía Líquida de Alta Presión/métodos , Animales , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
Prolonged use of non-steroidal anti-inflammatory drugs (NSAIDs) may reduce the risk of developing Alzheimer's disease (AD) and delay disease onset. Negative results of clinical AD trials were rationalised by the discovery that certain NSAIDs reduce amyloid-beta( 1-42) (A beta(1- 42)) peptide production, the proposed central culprit in AD pathophysiology and main constituent of amyloid plaques, whereas other compounds do not affect A beta levels. Latter observations motivated further in-vitro and in-vivo research regarding the applicability of NSAIDs in treating and/or preventing AD. We used the age-dependent cognitive decline in the APP23 transgenic mouse model for AD to evaluate disease-modifying efficacy of chronic ibuprofen treatment at the cognitive level. At age 6 weeks, heterozygous APP23 mice and control littermates were subcutaneously implanted with osmotic pumps delivering saline or ibuprofen (50 mg/kg daily). After 2 months of treatment, a 3-week washout period prevented bias from potential symptomatic effects before cognitive evaluation commenced. Ibuprofen-treated APP23 mice performed significantly better than their sham-treated counterparts and almost attained the same level of performance as control animals on a complex visual-spatial learning task. This study clearly reports disease-modifying efficacy of ibuprofen at the cognitive level in transgenic mice modelling AD.