RESUMEN
BACKGROUND: Recently, the hypothesis that pathological α-Synuclein propagates from the gut to the brain has gained attention. Although results from animal studies support this hypothesis, the specific mechanism remains unclear. This study focused on the intestinal fatty acid-binding protein (FABP2), which is one of the subtypes of fatty acid binding proteins localizing in the gut, with the hypothesis that FABP2 is involved in the gut-to-brain propagation of α-synuclein. The aim of this study was to clarify the pathological significance of FABP2 in the pathogenesis and progression of synucleinopathy. METHODS: We examined the relationship between FABP2 and α-Synuclein in the uptake of α-Synuclein into enteric neurons using primary cultured neurons derived from mouse small intestinal myenteric plexus. We also quantified disease-related protein concentrations in the plasma of patients with synucleinopathy and related diseases, and analyzed the relationship between plasma FABP2 level and progression of the disease. RESULTS: Experiments on α-Synuclein uptake in primary cultured enteric neurons showed that following uptake, α-Synuclein was concentrated in areas where FABP2 was localized. Moreover, analysis of the plasma protein levels of patients with Parkinson's disease revealed that the plasma FABP2 and α-Synuclein levels fluctuate with disease duration. The FABP2/α-Synuclein ratio fluctuated more markedly than either FABP2 or α-Synuclein alone, depending on the duration of disease, indicating a higher discriminant ability of early Parkinson's disease patients from healthy patients. CONCLUSIONS: These results suggest that FABP2 potentially contributes to the pathogenesis and progression of α-synucleinopathies. Thus, FABP2 is an important molecule that has the potential to elucidate the consistent mechanisms that lead from the prodromal phase to the onset and subsequent progression of synucleinopathies.
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Enfermedad de Parkinson , Sinucleinopatías , Animales , Humanos , Ratones , alfa-Sinucleína/metabolismo , Proteínas de Unión a Ácidos Grasos/metabolismo , Neuronas/metabolismo , Enfermedad de Parkinson/metabolismo , Sinucleinopatías/metabolismo , Sinucleinopatías/patologíaRESUMEN
BACKGROUND: Parkinson's disease (PD) is a heterogeneous neurodegenerative disorder characterized by motor and nonmotor symptoms. Several features have prognostic importance and have been used as key indicators for identifying clinical subtypes. However, the symptom-based classification approach has limitations with respect to the stability of the obtained subtypes. OBJECTIVES: The purpose of this study was to identify subtypes of PD using nuclear imaging biomarkers targeting the cardiac sympathetic nervous and nigro-striatal systems and to compare patterns of cortical morphological change among obtained subtypes. METHODS: We performed unbiased hierarchical cluster analysis using 123 I-metaiodobenzylguanidine cardiac scintigraphy and 123 I-N-(3-fluoropropyl)-2ß-carbomethoxy-3ß-(4-iodophenyl) nortropane single photon emission computed tomography data for 56 patients with PD. We compared clinical characteristics and the patterns of cortical atrophy in the obtained clusters. RESULTS: Three clusters were identified and showed distinct characteristics in onset ages and dopamine-replacement therapy and deep brain stimulation requirements. According to the characteristics, clusters were classified into two subtypes, namely, "cardio-cortical impairment (CC)" and "dopaminergic-dominant dysfunction (DD)" subtype. The three clusters were named according to subtype and time since onset in which 14 patients were classified as "early DD," 25 as "advanced DD," and 17 as "early CC." Compared with the early DD subtype, the early CC subtype showed parietal-dominant diffuse cortical atrophy and the advanced DD subtype showed left-side predominant mild cortical atrophy. CONCLUSIONS: Nuclear imaging biomarker-based classification can be used to identify clinically and pathologically relevant PD subtypes with distinct disease trajectories. © 2023 International Parkinson and Movement Disorder Society.
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Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/diagnóstico , Cintigrafía , Tomografía Computarizada de Emisión de Fotón Único/métodos , Cuerpo Estriado/metabolismo , Atrofia , Tropanos , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismoRESUMEN
Corticobasal syndrome is a clinical entity characterized by asymmetric akinetic rigidity and a variety of higher cortical dysfunction. Predicting background pathology of corticobasal syndrome is rather challenging; however, clinical and neuroimaging findings may provide a clue to its etiopathological origin. Visuospatial dysfunction of posterior cortical atrophy and logopenic-type language impairment indicate the presence of Alzheimer's disease-related pathology, and they provide useful information in distinguishing Alzheimer's disease from other types of corticobasal syndrome. Here we describe a case of corticobasal syndrome who showed characteristic visuospatial symptoms with imaging evidence of Alzheimer's disease supported by amyloid-PET and tau/astrogliosis-PET. Early, accurate diagnosis based on clinical features and predictable biomarkers is mandatory to the success of early intervention in corticobasal syndrome associated with Alzheimer's disease.
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Enfermedad de Alzheimer , Degeneración Corticobasal , Humanos , Enfermedad de Alzheimer/patología , Proteínas tau , Tomografía de Emisión de Positrones , Biomarcadores , Atrofia/complicacionesRESUMEN
OBJECTIVE: This study aimed to examine echolalia and its related symptoms and brain lesions in primary progressive aphasia (PPA). METHODS: Forty-five patients with PPA were included: 19 nonfluent/agrammatic variant PPA (nfvPPA), 5 semantic variant PPA, 7 logopenic variant PPA, and 14 unclassified PPA patients. We detected echolalia in unstructured conversations. An evaluation of language function and the presence of parkinsonism, grasp reflex, imitation behaviour, and disinhibition were assessed. We also measured regional cerebral blood flow (rCBF) using single-photon emission computed tomography. RESULTS: Echolalia was observed in 12 nfvPPA and 2 unclassified PPA patients. All patients showed mitigated echolalia. We compared nfvPPA patients with echolalia (echolalia group) to those without echolalia (non-echolalia group). The median age of the echolalia group was significantly lower than that of the non-echolalia group, and the echolalia group showed a significantly worse auditory comprehension performance than the non-echolalia group. In contrast, the performance of repetition tasks was not different between the two groups. The prevalence of imitation behaviour in the echolalia group was significantly higher than that in the non-echolalia group. The rCBFs in the bilateral pre-supplementary motor area and bilateral middle cingulate cortex in the echolalia group were significantly lower than those in the non-echolalia group. CONCLUSIONS: These findings suggest that echolalia is characteristic of nfvPPA patients with impaired comprehension. Reduced inhibition of the medial frontal cortex with release activity of the anterior perisylvian area account for the emergence of echolalia.
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Afasia Progresiva Primaria , Afasia , Afasia Progresiva Primaria no Fluente , Afasia Progresiva Primaria/diagnóstico por imagen , Afasia Progresiva Primaria/epidemiología , Ecolalia , Humanos , LenguajeRESUMEN
Both intrinsic and extrinsic motivation are believed to involve brain regions that are innervated by the dopaminergic pathway. Although dopaminergic neurons in the midbrain deteriorate in Parkinson's disease (PD), it remains unclear whether intrinsic motivation is impaired in PD patients. To address this issue, we investigated intrinsic motivation in PD patients using a task designed to assess the "Pandora effect," which constitutes a curiosity for resolving uncertainty, even if this curiosity is likely to result in negative consequences. Twenty-seven PD patients and 27 age-matched healthy controls (HCs) completed a curiosity task in which they were required to decide either to view or skip negative pictures (e.g., snakes, spiders) and an examination battery that included the Mini-Mental State Examination, a verbal fluency test, the Trail Making Test, 10-word recall tests, and questionnaires for behavioral inhibition/activation and depression. DaTSCAN images to assess the distribution of dopamine transporters in the striatum were acquired only from PD patients. The results revealed that PD patients, relative to the HCs, viewed the pictures less frequently under both the certain and uncertain conditions. However, both the PD patients and HCs viewed the pictures at a higher frequency under the uncertain condition than under the certain condition. In the PD patients, the proportion of pictures viewed under the certain condition was positively correlated with the distribution of dopamine transporters in the striatum. These results suggest that despite the overall decreasing level of interest in viewing negative pictures, the motivation to resolve uncertainty is relatively intact in PD patients.
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Proteínas de Transporte de Dopamina a través de la Membrana Plasmática , Enfermedad de Parkinson , Conducta Exploratoria , Humanos , Motivación , Pruebas Neuropsicológicas , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/diagnóstico por imagenRESUMEN
AIM: To evaluate the association between small for gestational age (SGA) and the prevalence of congenital heart disease (CHD) and the association of the SGA status with the outcomes among infants with CHD. METHODS: Echocardiography was performed within the first 5 days of life in 5664 consecutive infants. Infants were classified into four groups according to the presence or absence of SGA and CHD. All CHD infants were followed up until either spontaneous resolution of all cardiac lesions, invasive intervention or death. All newborns without CHD were followed for mortality until the final follow-up date. RESULTS: A total of 303 infants were diagnosed with CHD, while 610 were diagnosed with SGA. Among the CHD infants, 56 were SGA, and 247 were not. A multivariable logistic regression analysis showed that the adjusted odds ratio of SGA (9.71, P < .001) was significantly higher than that of other parameters concerning predictors of invasive intervention or death. The mortality rate in the presence of both SGA and CHD (hazard ratio: 33.6, P < .001) was markedly higher than in the absence of both. CONCLUSION: SGA was a significant predictor of invasive intervention for CHD. The combination of CHD and SGA carried a high risk of death beyond that of either alone.
Asunto(s)
Cardiopatías Congénitas , Recién Nacido Pequeño para la Edad Gestacional , Edad Gestacional , Cardiopatías Congénitas/epidemiología , Humanos , Recién Nacido , PrevalenciaRESUMEN
Mutations in DNAJC13 gene have been linked to familial form of Parkinson's disease (PD) with Lewy pathology. DNAJC13 is an endosome-related protein and believed to regulate endosomal membrane trafficking. However, the mechanistic link between DNAJC13 mutation and α-synuclein (αSYN) pathology toward neurodegeneration remains poorly understood. In this study, we showed that PD-linked N855S-mutant DNAJC13 caused αSYN accumulation in the endosomal compartment, presumably due to defective cargo trafficking from the early endosome to the late and/or recycling endosome. In vivo experiments using human αSYN transgenic flies showed that mutant DNAJC13 not only increased the amount of insoluble αSYN in fly head but also induced dopaminergic neurodegeneration, rough eye phenotype and age-dependent locomotor impairment. Together, these findings suggest that DNAJC13 mutation perturbs multi-directional endosomal trafficking, resulting in the aberrant endosomal retention of αSYN, which might predispose to the neurodegenerative process that leads to PD.
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Endosomas/metabolismo , Proteínas de Filamentos Intermediarios/metabolismo , Chaperonas Moleculares/genética , Mutación , Enfermedad de Parkinson/genética , Actinas/metabolismo , Animales , Animales Modificados Genéticamente , Transporte Biológico , Células COS , Chlorocebus aethiops , Neuronas Dopaminérgicas/patología , Drosophila/genética , Endosomas/genética , Ojo/patología , Humanos , Proteínas de Filamentos Intermediarios/genética , Locomoción/genética , Chaperonas Moleculares/metabolismo , Síndromes de Neurotoxicidad/etiología , Síndromes de Neurotoxicidad/genética , Enfermedad de Parkinson/fisiopatologíaRESUMEN
BACKGROUND: Cholinergic dysfunction plays a key role in cognitive dysfunction in Parkinson's disease (PD). Recent studies revealed that atrophy in the nucleus basalis of Meynert (NBM), the largest cholinergic nucleus in the basal forebrain, heralds cognitive decline in PD. Despite clinical importance of NBM atrophy in PD, clinical and radiological correlates of NBM atrophy remains to be elucidated. OBJECTIVE: We investigated the longitudinal changes in clinical and cerebral glucose metabolic characteristics in PD with atrophy in the NBM. METHODS: We analyzed the 3-year longitudinal data of 56 PD patients who underwent motor, nonmotor, and imaging evaluations at baseline. The patients were classified into PD with and without NBM atrophy based on the results of magnetic resonance imaging volumetry. We compared clinical characteristics and cerebral glucose metabolic changes between PD with and without NBM atrophy. RESULTS: At baseline, 20 patients and 36 patients were classified into PD with and without NBM atrophy groups, respectively. At follow-up, the data of the 14 PD patients in the NBM atrophy group and the 18 patients in the group without NBM atrophy completed full assessments and were available for the analysis. The PD with NBM atrophy group showed severe cognitive dysfunction and psychiatric symptoms both at baseline and follow-up. The NBM volume significantly correlated with motor and nonmotor functions. The PD with NBM atrophy showed significantly reduced metabolism in the parietal and occipital cortices both at baseline and follow-up. CONCLUSIONS: Basal forebrain atrophy is a simple and sensible marker of faster disease progression and cortical hypometabolism in PD. © 2020 International Parkinson and Movement Disorder Society.
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Prosencéfalo Basal , Disfunción Cognitiva , Enfermedad de Parkinson , Atrofia/patología , Prosencéfalo Basal/diagnóstico por imagen , Núcleo Basal de Meynert/patología , Corteza Cerebral/diagnóstico por imagen , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/etiología , Disfunción Cognitiva/patología , Humanos , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/diagnóstico por imagen , Enfermedad de Parkinson/patologíaRESUMEN
The neuropathological hallmarks of Parkinson's disease (PD) include the appearance of α-synuclein (α-SYN)-positive Lewy bodies (LBs) and the loss of catecholaminergic neurons. Thus, a potential mechanism promoting the uptake of extracellular α-SYN may exist in susceptible neurons. Of the various differentially expressed proteins, we are interested in flotillin (FLOT)-1 because this protein is highly expressed in the brainstem catecholaminergic neurons and is strikingly up-regulated in PD brains. In this study, we found that extracellular monomeric and fibrillar α-SYN can potentiate FLOT1-dopamine transporter (DAT) binding and pre-endocytic clustering of DAT on the cell surface, thereby facilitating DAT endocytosis and down-regulating its transporter activity. Moreover, we demonstrated that α-SYN itself exploited the DAT endocytic process to enter dopaminergic neuron-like cells, and both FLOT1 and DAT were found to be the components of LBs. Altogether, these findings revealed a novel role of extracellular α-SYN on cellular trafficking of DAT and may provide a rationale for the cell type-specific, functional, and pathologic alterations in PD.-Kobayashi, J., Hasegawa, T., Sugeno, N., Yoshida, S., Akiyama, T., Fujimori, K., Hatakeyama, H., Miki, Y., Tomiyama, A., Kawata, Y., Fukuda, M., Kawahata, I., Yamakuni, T., Ezura, M., Kikuchi, A., Baba, T., Takeda, A., Kanzaki, M., Wakabayashi, K., Okano, H., Aoki, M. Extracellular α-synuclein enters dopaminergic cells by modulating flotillin-1-assisted dopamine transporter endocytosis.
Asunto(s)
Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Dopamina/metabolismo , Neuronas Dopaminérgicas/patología , Cuerpos de Lewy/patología , Proteínas de la Membrana/metabolismo , Enfermedad de Parkinson/patología , alfa-Sinucleína/metabolismo , Anciano , Anciano de 80 o más Años , Encéfalo/metabolismo , Encéfalo/patología , Membrana Celular/metabolismo , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/genética , Neuronas Dopaminérgicas/metabolismo , Endocitosis , Humanos , Cuerpos de Lewy/metabolismo , Proteínas de la Membrana/genética , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/metabolismo , Transporte de Proteínas , alfa-Sinucleína/genéticaRESUMEN
BACKGROUND: Delayed diagnosis of critical congenital heart disease (CCHD) carries a serious risk of mortality, morbidity, and handicap. As echocardiography is commonly used to diagnose congenital heart disease (CHD), echocardiographic investigations in newborns may be helpful in detecting CCHD earlier and with higher sensitivity than when using other screening methods. The present study aimed to evaluate the effectiveness of echocardiographic screening for CCHD in a tertiary care center. METHODS: A retrospective chart review was conducted among newborns delivered at Hamamatsu University Hospital between June 2009 and May 2016. The study included consecutive newborns who underwent early echocardiographic screening (within the first 5 days of life) performed by pediatric cardiologists, were born at ≥36 weeks of gestation, had a birthweight ≥2300 g, and were cared for in the well-baby nursery. Newborns admitted to the neonatal intensive care unit, as well as those with prenatal diagnosis of CHD and/or clinical symptoms or signs of CHD were excluded. Four CHD outcome categories were defined: critical, serious, clinically significant, and clinically non-significant. RESULTS: A total of 4082 live newborns were delivered during the study period. Of 3434 newborns who met the inclusion criteria and had complete echocardiography data, 104 (3.0%) were diagnosed as having CHD. Among these, none was initially diagnosed as having critical or serious CHD. Of the 95 newborns who continued follow-up with a cardiologist, 61 (64%) were determined to have non-significant CHDs that resolved within 6 months of life. Review of excluded newborns revealed nine cases of critical or serious CHD; among these newborns, six were diagnosed prenatally and three had some clinical signs of CHD prior to hospital discharge. CONCLUSIONS: In our tertiary care center, echocardiography screening within the first 5 days of life did not help improve CCHD detection rate in newborns without prenatal diagnosis or clinical signs of CHD. Echocardiographic screening may be associated with increased rate of false-positives (defects resulting in clinically non-significant CHDs) in newborns without prenatal diagnosis or suspicion of CHD.
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Ecocardiografía , Cardiopatías Congénitas/diagnóstico por imagen , Enfermedades del Recién Nacido/diagnóstico por imagen , Tamizaje Neonatal/métodos , Diagnóstico Tardío/prevención & control , Femenino , Humanos , Recién Nacido , Masculino , Estudios Retrospectivos , Centros de Atención TerciariaRESUMEN
BACKGROUND: Although persistent pulmonary hypertension of the newborn (PPHN) and infantile hypertrophic pyloric stenosis (HPS) are both well-known diseases that occur in early infancy, PPHN complicated by HPS is rare. As nitric oxide (NO) is an important mediator of biological functions, on both the vascular endothelium and smooth muscle cells, the decreased production of NO might play a role in the pathogenesis of both PPHN and HPS. We present the case of a neonate who developed HPS following PPHN, including a detailed review on research published to date, and we discuss the pathogenesis of PPHN and HPS. CASE PRESENTATION: A female neonate born at 38 weeks of gestation, weighing 3140âg, developed PPHN due to meconium aspiration syndrome. Intensive treatment with high frequency oscillations and inhaled NO were initiated, and sildenafil and bosentan were added. She gradually recovered. At 15 days of age, the patient developed recurrent vomiting after feeding and the diagnosis of HPS was made. Intravenous atropine therapy was started at 20 days of age, but the efficacy was clinically unsatisfactory. The coadministration with transdermal nitroglycerin improved the symptoms, and oral feeding was successfully re-introduced. CONCLUSIONS: Our patient recovered from both PPHN and HPS using NO-related medications. A decrease in NO synthesis is likely to be a common pathway for PPHN and HPS.
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Síndrome de Circulación Fetal Persistente/complicaciones , Estenosis Hipertrófica del Piloro/etiología , Antihipertensivos/uso terapéutico , Atropina/uso terapéutico , Bosentán/uso terapéutico , Broncodilatadores/uso terapéutico , Femenino , Ventilación de Alta Frecuencia , Humanos , Recién Nacido , Síndrome de Aspiración de Meconio/complicaciones , Síndrome de Aspiración de Meconio/terapia , Antagonistas Muscarínicos/uso terapéutico , Óxido Nítrico/uso terapéutico , Donantes de Óxido Nítrico/uso terapéutico , Nitroglicerina/uso terapéutico , Síndrome de Circulación Fetal Persistente/etiología , Síndrome de Circulación Fetal Persistente/terapia , Estenosis Hipertrófica del Piloro/tratamiento farmacológico , Citrato de Sildenafil/uso terapéutico , Vasodilatadores/uso terapéuticoRESUMEN
Agrammatism is one of the core clinical features of non-fluent/agrammatic variant primary progressive aphasia, and it has traditionally been considered the hallmark of non-fluent aphasia in Western countries. However, agrammatic speech may remain undetected in Japanese patients because of the agglutinative structure of the language and high flexibility in word order. In the present study, we aimed to analyze agrammatism in the speech production of Japanese patients with aphasia due to neurodegenerative disease using an anagram test generated by our laboratory. Four patients were recruited from the dementia clinic at Tohoku University Hospital between December 2014 and August 2015: two patients with non-fluent/agrammatic variant primary progressive aphasia, one with semantic variant primary progressive aphasia, and one with probable Alzheimer's disease experiencing episodic memory impairment accompanied by transcortical sensory aphasia. All patients underwent thorough neurological and neuropsychological testing before performing a Japanese anagram task based on the Northwestern Anagram Test. Our findings indicated that the two patients with non-fluent/agrammatic variant primary progressive aphasia exhibited poorer performance on the anagram task than the remaining two patients. Therefore, the anagram test used in the present study may aid in detecting output aspects of agrammatism in Japanese patients with aphasia, although future studies are required to develop a standardized version of test.
Asunto(s)
Enfermedad de Alzheimer/complicaciones , Afasia de Broca/fisiopatología , Trastornos del Lenguaje/diagnóstico , Lenguaje , Afasia Progresiva Primaria no Fluente/diagnóstico , Anciano de 80 o más Años , Femenino , Humanos , Trastornos del Lenguaje/fisiopatología , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Afasia Progresiva Primaria no Fluente/fisiopatología , Semántica , HablaRESUMEN
OBJECTIVE: Patients with Lewy body disease develop a variety of psychotic and misperception symptoms, including visual hallucinations and delusions, as well as 'minor hallucinations', that is, a sense of presence, passage hallucinations and visual illusions. Although these symptoms have been suggested to have common underlying mechanisms, the commonalities and differences among them have not been systematically investigated at the neural level. METHODS: Sixty-seven patients with Parkinson's disease underwent neuropsychological and behavioural assessments, volumetric MRI and 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET). A factor analysis was performed to discover correlations among psychotic and misperception symptoms, other behavioural symptoms and neuropsychological performances. Partial least-squares correlation analysis was used to investigate the relationship between these symptoms and the joint features of MRI and FDG-PET. RESULTS: A sense of presence, passage hallucinations and visual illusions constituted a single behavioural factor (minor hallucinations/illusions). Visual hallucinations formed another behavioural factor along with delusions, depression and fluctuating cognition (psychosis/dysphoria). Three distinct brain-behaviour correlation patterns were identified: (1) posterior cortical atrophy/hypometabolism associated with minor hallucinations/illusions and visuospatial impairment; (2) upper brainstem and thalamic atrophy/hypometabolism associated with psychosis/dysphoria and (3) frontal cortical atrophy/hypometabolism associated with non-visual cognition. No significant differences in neuroimaging findings were identified between patients who had minor hallucinations/illusions alone and patients who also had visual hallucinations. CONCLUSIONS: Our findings suggest that combined damage to the upper brainstem/thalamus and the posterior neocortex underlies both minor hallucinations/illusions and visual hallucinations and that the former pathology is more associated with visual hallucinations/frank psychosis and the latter is more associated with minor hallucinations/illusions.
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Alucinaciones/psicología , Enfermedad de Parkinson/complicaciones , Trastornos Psicóticos/complicaciones , Anciano , Encéfalo/patología , Tronco Encefálico/diagnóstico por imagen , Tronco Encefálico/patología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Pruebas Neuropsicológicas , Tomografía de Emisión de Positrones , Trastornos Psicóticos/psicología , Factores de Riesgo , Tálamo/diagnóstico por imagen , Tálamo/patologíaAsunto(s)
Dermatitis del Pañal , Errores Innatos del Metabolismo de los Metales , Óxido de Zinc , Dermatitis del Pañal/diagnóstico , Dermatitis del Pañal/tratamiento farmacológico , Dermatitis del Pañal/etiología , Humanos , Lactante , Índice de Severidad de la Enfermedad , Óxido de Zinc/efectos adversosRESUMEN
Parkinson's disease (PD) is the second most common neurodegenerative disorder that is characterized by progressive movement disability and a variety of non-motor symptoms. The neuropathology of PD consists of the loss of dopaminergic neurons in the midbrain and the appearance of neuronal inclusions called Lewy bodies, which contain insoluble α-synuclein, a relatively small protein originally identified in association with synaptic vesicles in the presynaptic nerve terminals. Drugs that replenish dopamine can partly alleviate the motor symptoms, but they do not cure the disease itself. Therefore, there is an urgent need for disease modification in terms of the delay or prevention of neurodegeneration. Recent advances in genetic and biochemical studies have provided unifying conceptual frameworks of the pathogenesis of PD. Particularly, membrane trafficking has aroused special attention as an initiator or enhancer of the neurodegenerative process that leads to PD. Defects in the cellular trafficking pathway result in synaptic dysfunction and the accumulation of misfolded α-synuclein. Likewise, changes in intracellular sorting and degradation profoundly influence the cellular trafficking of misfolded proteins, thereby facilitating the cell-to-cell spreading of hazardous α-synuclein species in a prion-like manner. Here, we will review our current knowledge of the functional roles of membrane trafficking in PD and will discuss how this cellular process could induce or facilitate the functional and pathological alterations in this disease.
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Membrana Celular/metabolismo , Enfermedad de Parkinson/metabolismo , Muerte Celular , Humanos , Modelos Biológicos , Neuronas/patología , alfa-Sinucleína/metabolismoRESUMEN
BACKGROUND: The morbidity and mortality rates due to cardiovascular events such as myocardial infarction are known to exhibit seasonal variations. Moreover, changes in the ambient temperature are reportedly associated with an increase in these events, which may potentially involve blood coagulation markers. Bleeding due to vitamin K deficiency in neonates, which is associated with high mortality and a high frequency of neurological sequelae, is more commonly observed during the summer season and in warm regions in Japan. To determine the presence of seasonal variation and the influence of ambient temperature on blood coagulation markers in healthy term neonates, we assessed the international normalized ratio (INR) values measured using CoaguChek XS. METHODS: We studied 488 consecutive healthy term neonates who were born at a perinatal center between July 2012 and June 2013. The INR values were measured using CoaguChek XS in 4-day-old neonates who received nursing care in the newborn nursery throughout the duration of hospitalization. The seasonal variations in the INR values and environmental effects on the INR were assessed. RESULTS: The mean monthly INR values peaked in July (1.13 ± 0.08), whereas the lowest values were observed in January (1.05 ± 0.08). Higher levels of INR were observed during the summer season (June to August) than during the winter season (December to February). Simple linear regression analysis indicated the presence of weakly positive but significant correlations between INR and outdoor temperature (r = 0.25, p < 0.001), outdoor relative humidity (r = 0.19, p < 0.001), and room relative humidity (r = 0.24, p < 0.001), and the presence of a significant negative correlation between INR and room temperature (r = -0.13, p = 0.02). Furthermore, multiple linear regression analysis showed that only outdoor temperature significantly influenced the INR. CONCLUSIONS: A seasonal variation in the INR values was observed among neonates, possibly due to the variation in ambient temperature. Even though the neonates received nursing care in the newborn nursery that was constantly air-conditioned, the outdoor temperature was the most influential factor on INR.
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Coagulación Sanguínea/fisiología , Humedad , Relación Normalizada Internacional , Estaciones del Año , Temperatura , Femenino , Humanos , Recién Nacido , Japón , Modelos Lineales , Masculino , Estudios Prospectivos , Valores de ReferenciaRESUMEN
α-Synuclein (aS) is a major constituent of Lewy bodies, which are not only a pathological marker for Parkinson disease but also a trigger for neurodegeneration. Cumulative evidence suggests that aS spreads from cell to cell and thereby propagates neurodegeneration to neighboring cells. Recently, Nedd4-1 (neural precursor cell expressed developmentally down-regulated protein 4-1), an E3 ubiquitin ligase, was shown to catalyze the Lys-63-linked polyubiquitination of intracellular aS and thereby facilitate aS degradation by the endolysosomal pathway. Because Nedd4-1 exerts its activity in close proximity to the inner leaflet of the plasma membrane, we speculate that after the internalization of aS the membrane resident aS is preferentially ubiquitinated by Nedd4-1. To clarify the role of Nedd4-1 in aS internalization and endolysosomal sequestration, we generated aS mutants, including ΔPR1(1-119 and 129-140), ΔC(1-119), and ΔPR2(1-119 and 134-140), that lack the proline-rich sequence, a putative Nedd4-1 recognition site. We show that wild type aS, but not ΔPR1, ΔPR2, or ΔC aS, is modified by Nedd4-1 in vitro, acquiring a Lys-63-linked ubiquitin chain. Compared with the mutants lacking the proline-rich sequence, wild type-aS is preferentially internalized and translocated to endosomes. The overexpression of Nedd4-1 increased aS in endosomes, whereas RNAi-mediated silencing of Nedd4-1 decreased endosomal aS. Although aS freely passes through plasma membranes within minutes, a pulse-chase experiment revealed that the overexpression of Nedd4-1 markedly decreased the re-secretion of internalized aS. Together, these findings demonstrate that Nedd4-1-linked Lys-63 ubiquitination specifies the fate of extrinsic and de novo synthesized aS by facilitating their targeting to endosomes.
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Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Endosomas/metabolismo , Lisina/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo , Secuencias de Aminoácidos , Línea Celular Tumoral , Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , Endosomas/genética , Humanos , Lisina/genética , Ubiquitina-Proteína Ligasas Nedd4 , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/metabolismo , Transporte de Proteínas , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación , alfa-Sinucleína/genéticaRESUMEN
Mutations in vacuolar protein sorting 35 (VPS35) have been linked to familial Parkinson's disease (PD). VPS35, a component of the retromer, mediates the retrograde transport of cargo from the endosome to the trans-Golgi network. Here we showed that retromer depletion increases the lysosomal turnover of the mannose 6-phosphate receptor, thereby affecting the trafficking of cathepsin D (CTSD), a lysosome protease involved in α-synuclein (αSYN) degradation. VPS35 knockdown perturbed the maturation step of CTSD in parallel with the accumulation of αSYN in the lysosomes. Furthermore, we found that the knockdown of Drosophila VPS35 not only induced the accumulation of the detergent-insoluble αSYN species in the brain but also exacerbated both locomotor impairments and mild compound eye disorganization and interommatidial bristle loss in flies expressing human αSYN. These findings indicate that the retromer may play a crucial role in αSYN degradation by modulating the maturation of CTSD and might thereby contribute to the pathogenesis of the disease.
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Proteínas de Drosophila/genética , Lisosomas/metabolismo , Mutación/genética , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/metabolismo , Proteínas de Transporte Vesicular/genética , alfa-Sinucleína/metabolismo , Animales , Animales Modificados Genéticamente , Encéfalo/metabolismo , Encéfalo/patología , Catepsina D/metabolismo , Modelos Animales de Enfermedad , Drosophila , Ojo/metabolismo , Ojo/patología , Regulación de la Expresión Génica/genética , Células HEK293 , Humanos , Inmunoprecipitación , Locomoción/genética , Enfermedad de Parkinson/patología , Transporte de Proteínas/genética , Interferencia de ARN/fisiología , Fracciones Subcelulares/metabolismo , Fracciones Subcelulares/ultraestructuraRESUMEN
BACKGROUND: Neonates routinely receive vitamin K to prevent vitamin K deficiency bleeding, which is associated with a high mortality rate and a high frequency of neurological sequelae. A coagulation screening test might be necessary to detect prophylactic failure or incomplete prophylaxis. However, venous access and the volume of blood required for such testing can be problematic. CoaguChek XS is a portable device designed to monitor prothrombin time while only drawing a small volume of blood. Although the device is used in adults and children, studies have not been performed to evaluate its clinical utility in neonates, and the reference value is unknown in this population. The objectives of the present study were to determine the reference intervals (RIs) for international normalized ratio (INR) using the CoaguChek XS by capillary puncture in healthy term neonates, to evaluate factors that correlate with INR, and to evaluate the device by assessing its ease of use in clinical practice. METHODS: This study included 488 healthy term neonates born at a perinatal center between July 2012 and June 2013. The INRs determined by CoaguChek XS were measured in 4-day-old neonates. RESULTS: The enrolled neonates were orally administered vitamin K 6-12 h after birth. A RI for INRs in 4-day-old neonates was established using the CoaguChek XS with a median value of 1.10 and a range of 0.90-1.30. A significant difference in the INR was noted between male (median value, 1.10; RI, 0.90-1.30) and female (median value, 1.10; RI, 0.90-1.24) neonates (p = 0.049). The INR was found to correlate with gestational age, birth weight, and hematocrit value. CONCLUSIONS: The CoaguChek XS device is safe, fast, and convenient for performing INR assays in neonates. Our study is the first to establish a RI for INRs that were measured using the CoaguChek XS in healthy term neonates.
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Monitoreo de Drogas/instrumentación , Relación Normalizada Internacional/instrumentación , Sistemas de Atención de Punto , Tiempo de Protrombina/instrumentación , Sangrado por Deficiencia de Vitamina K/prevención & control , Vitamina K/uso terapéutico , Vitaminas/uso terapéutico , Administración Oral , Esquema de Medicación , Monitoreo de Drogas/métodos , Femenino , Humanos , Recién Nacido , Relación Normalizada Internacional/métodos , Relación Normalizada Internacional/normas , Modelos Lineales , Masculino , Estudios Prospectivos , Tiempo de Protrombina/métodos , Tiempo de Protrombina/normas , Valores de Referencia , Resultado del Tratamiento , Sangrado por Deficiencia de Vitamina K/sangreRESUMEN
Dementia is one of the most debilitating symptoms of Parkinson's disease. A recent longitudinal study suggests that up to 80% of patients with Parkinson's disease will eventually develop dementia. Despite its clinical importance, the development of dementia is still difficult to predict at early stages. We previously identified olfactory dysfunction as one of the most important indicators of cortical hypometabolism in Parkinson's disease. In this study, we investigated the possible associations between olfactory dysfunction and the risk of developing dementia within a 3-year observation period. Forty-four patients with Parkinson's disease without dementia underwent the odour stick identification test for Japanese, memory and visuoperceptual assessments, (18)F-fluorodeoxyglucose positron emission tomography scans and magnetic resonance imaging scans at baseline and 3 years later. A subgroup of patients with Parkinson's disease who exhibited severe hyposmia at baseline showed more pronounced cognitive decline at the follow-up survey. By the end of the study, 10 of 44 patients with Parkinson's disease had developed dementia, all of whom had severe hyposmia at baseline. The multivariate logistic analysis identified severe hyposmia and visuoperceptual impairment as independent risk factors for subsequent dementia within 3 years. The patients with severe hyposmia had an 18.7-fold increase in their risk of dementia for each 1 SD (2.8) decrease in the score of odour stick identification test for Japanese. We also found an association between severe hyposmia and a characteristic distribution of cerebral metabolic decline, which was identical to that of dementia associated with Parkinson's disease. Furthermore, volumetric magnetic resonance imaging analyses demonstrated close relationships between olfactory dysfunction and the atrophy of focal brain structures, including the amygdala and other limbic structures. Together, our findings suggest that brain regions related to olfactory function are closely associated with cognitive decline and that severe hyposmia is a prominent clinical feature that predicts the subsequent development of Parkinson's disease dementia.