377 research outputs found

    PMCA4 (ATP2B4) mutation in familial spastic paraplegia causes delay in intracellular calcium extrusion

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    Background: Familial spastic paraplegia (FSP) is a heterogeneous group of disorders characterized primarily by progressive lower limb spasticity and weakness. More than 50 disease loci have been described with different modes of inheritance. Recently, we described a novel missense mutation (c.803G>A, p.R268Q) in the plasma membrane calcium ATPase (PMCA4, or ATP2B4) gene in a Chinese family with autosomal dominant FSP. Further to this finding, here we describe the functional effect of this mutation. Methods: As PMCA4 removes cytosolic calcium, we measured transient changes and the time-dependent decay of cytosolic calcium level as visualized by using fura-2 fluorescent dye with confocal microscopy in human SH-SY5Y neuroblastoma cells overexpressing either wild-type or R268Q mutant PMCA4. Results: Overexpressing both wild-type and R268Q PMCA4 significantly reduced maximum calcium surge after KCl-induced depolarization as compared with vector control cells. However, cells overexpressing mutant PMCA4 protein demonstrated significantly higher level of calcium surge when compared with wild-type. Furthermore, the steady-state cytosolic calcium concentration in these mutant cells remained markedly higher than the wild-type after SERCA inhibition by thapsigargin. Conclusion: Our result showed that p.R268Q mutation in PMCA4 resulted in functional changes in calcium homeostasis in human neuronal cells. This suggests that calcium dysregulation may be associated with the pathogenesis of FSP. © 2015 The Authors. Brain and Behavior published by Wiley Periodicals, Inc.published_or_final_versio

    TEMPERATURSUMME UND BLUHBEGINN BEI APFEL ZUSAMMENFASSUNG

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    Este artigo explora as maneiras pelas quais o design influencia as perceções e ações de estudantes e professores em cinco escolas secundárias do Reino Unido. O entendimento das diferentes práticas desenvolvidas nessas escolas vai além das típicas Avaliações Pós Ocupação (Post Occupancy Evaluations) que enfocam aspectos ambientais, como a aústica, a iluminação e a temperatura, usam métodos quantitativos e frequentemente deixam de explorar a forma como os diferentes fatores ambientais interagem com os usuários, ao longo do tempo time (HYGGE, 2003; GALASIU e VEITCH, 2006; SHAUGHNESSY et al., 2006; WINTERBOTTOM e WILKINS, 2009). Também ocorre uma falta de atenção em relação às maneiras como os processos de ocupação podem modelar as experiências em tais espaços (STABLES, LEAROYD-SMITH, DANIELS e TSE, 2014). A investigação envolveu estudos de casos que objetivavam documentar uma série de assuntos chave discutidos pelos professores e estudantes em cada uma dessas escolas. Os achados contribuem para o desenvolvimento de um entendimento mais holístico sobre as formas como o design pode contribuir para o processo de transformação pedagógica. Argumentamos que os espaços que são projetados para formas específicas de abordagem de ensino e aprendizagem podem ser transformados quando tais espaços são usados na prática (DANIELS et al., 2017 no prelo). Temos evidências de que mudanças subsequentes em termos de liderança frequentemente envolvem modificações adicionais dos espaços e das práticas de ensino e aprendizagem. Neste artigo, acrescentamos a ideia de que essas mudanças têm consequências para a experiência cotidiana de escolarização, como foi evidenciado nos comentários e nas ações dos professors e alunos. Esses aspectos são de particular importância neste momento. O Gabinete Nacional de Auditoria (The National Audit Office) (2017) chamou a atenção para o estado lamentável das construções que abrigam as escolas públicas. Apontou três preocupações: a condição dos prédios, a demanda crescente de vagas e os problemas relativos à entrega de projetos capitais. Fica claro que necessitamos aprender com as experiências e os resultados de abordagens recentes relativas ao design e à construção de novas escolas. Como o Departamento reconhece, desafios significativos permanecem. Espera-se que a condição das escolas piore na medida em que construções em estado ruim, mas não o pior possível, se deteriorem ainda mais. O número de estudantes continua a crecer e as demandas por vagas está voltada para as escolas secundárias, onde tais vagas são de provisão mais complexa e dispendiosa. O Departamento, as autoridades locais e as escolas necessitarão attender essas demandas em um momento em que sua capacidade de realizar programas capitais sofre pressão crescente decorrente da escassez de receita orcamentária

    The effect of ex-vivo rotenone intoxication on dopamine re-uptake of LRRK2-R1441G mutant mouse

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    An Exome-Chip Association Analysis in Chinese Subjects Reveals a Functional Missense Variant of GCKR That Regulates FGF21 Levels

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    Fibroblast growth factor 21 (FGF21) is increasingly recognized as an important metabolic regulator of glucose homeostasis. Here, we conducted an exome-chip association analysis by genotyping 5,169 Chinese individuals from a community-based cohort and two clinic-based cohorts. A custom Asian exome-chip was used to detect genetic determinants influencing circulating FGF21 levels. Single-variant association analysis interrogating 70,444 single nucleotide polymorphisms identified a novel locus, GCKR, significantly associated with circulating FGF21 levels at genome-wide significance. In the combined analysis, the common missense variant of GCKR, rs1260326 (p.Pro446Leu), showed an association with FGF21 levels after adjustment for age and sex (P = 1.61 × 10−12; β [SE] = 0.14 [0.02]), which remained significant on further adjustment for BMI (P = 3.01 × 10−14; β [SE] = 0.15 [0.02]). GCKR Leu446 may influence FGF21 expression via its ability to increase glucokinase (GCK) activity. This can lead to enhanced FGF21 expression via elevated fatty acid synthesis, consequent to the inhibition of carnitine/palmitoyl-transferase by malonyl-CoA, and via increased glucose-6-phosphate–mediated activation of the carbohydrate response element binding protein, known to regulate FGF21 gene expression. Our findings shed new light on the genetic regulation of FGF21 levels. Further investigations to dissect the relationship between GCKR and FGF21, with respect to the risk of metabolic diseases, are warranted.postprin

    Decitabine impact on the endocytosis regulator RhoA, the folate carriers RFC1 and FOLR1, and the glucose transporter GLUT4 in human tumors.

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    BackgroundIn 31 solid tumor patients treated with the demethylating agent decitabine, we performed tumor biopsies before and after the first cycle of decitabine and used immunohistochemistry (IHC) to assess whether decitabine increased expression of various membrane transporters. Resistance to chemotherapy may arise due to promoter methylation/downregulation of expression of transporters required for drug uptake, and decitabine can reverse resistance in vitro. The endocytosis regulator RhoA, the folate carriers FOLR1 and RFC1, and the glucose transporter GLUT4 were assessed.ResultsPre-decitabine RhoA was higher in patients who had received their last therapy >3 months previously than in patients with more recent prior therapy (P = 0.02), and varied inversely with global DNA methylation as assessed by LINE1 methylation (r = -0.58, P = 0.006). Tumor RhoA scores increased with decitabine (P = 0.03), and RFC1 also increased in patients with pre-decitabine scores ≤150 (P = 0.004). Change in LINE1 methylation with decitabine did not correlate significantly with change in IHC scores for any transporter assessed. We also assessed methylation of the RFC1 gene (alias SLC19A1). SLC19A1 methylation correlated with tumor LINE1 methylation (r = 0.45, P = 0.02). There was a small (statistically insignificant) decrease in SLC19A1 methylation with decitabine, and there was a trend towards change in SLC19A1 methylation with decitabine correlating with change in LINE1 methylation (r = 0.47, P <0.15). While SLC19A1 methylation did not correlate with RFC1 scores, there was a trend towards an inverse correlation between change in SLC19A1 methylation and change in RFC1 expression (r = -0.45, P = 0.19).ConclusionsIn conclusion, after decitabine administration, there was increased expression of some (but not other) transporters that may play a role in chemotherapy uptake. Larger patient numbers will be needed to define the extent to which this increased expression is associated with changes in DNA methylation

    The added value of quantitative multi-voxel MR spectroscopy in breast magnetic resonance imaging

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    To determine whether quantitative multivoxel MRS improves the accuracy of MRI in the assessment of breast lesions. Twenty-five consecutive patients with 26 breast lesions a parts per thousand yen1 cm assessed as BI-RADS 3 or 4 with mammography underwent quantitative multivoxel MRS and contrast-enhanced MRI. The choline (Cho) concentration was calculated using the unsuppressed water signal as a concentration reference. ROC analysis established the diagnostic accuracy of MRI and MRS in the assessment of breast lesions. Respective Cho concentrations in 26 breast lesions re-classified by MRI as BI-RADS 2 (n = 5), 3 (n = 8), 4 (n = 5) and 5 (n = 8) were 1.16 +/- 0.43 (mean +/- SD), 1.43 +/- 0.47, 2.98 +/- 2.15 and 4.94 +/- 3.10 mM. Two BI-RADS 3 lesions and all BI-RADS 4 and 5 lesions were malignant on histopathology and had Cho concentrations between 1.7 and 11.8 mM (4.03 +/- 2.72 SD), which were significantly higher (P = 0.01) than that in the 11 benign lesions (0.4-1.5 mM; 1.19 +/- 0.33 SD). Furthermore, Cho concentrations in the benign and malignant breast lesions in BI-RADS 3 category differed (P = 0.01). The accuracy of combined multivoxel MRS/breast MRI BI-RADS re-classification (AUC = 1.00) exceeded that of MRI alone (AUC = 0.96 +/- 0.03). These preliminary data indicate that multivoxel MRS improves the accuracy of MRI when using a Cho concentration cut-off a parts per thousand currency sign1.5 mM for benign lesions. Key Points aEuro cent Quantitative multivoxel MR spectroscopy can improve the accuracy of contrast-enhanced breast MRI. aEuro cent Multivoxel-MRS can differentiate breast lesions by using the highest Cho-concentration. aEuro cent Multivoxel-MRS can exclude patients with benign breast lesions from further invasive diagnostic procedures

    Clofarabine and high-dose cytosine arabinoside in the treatment of refractory or relapsed acute myeloid leukaemia

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    Clofarabine (40 mg/m2/day × 5) and high-dose cytosine arabinoside (Ara-C, 1–2 g/m2/day × 5) were used in 10 men and 11 women, at a median age of 45 (22–62) years, with refractory (N = 4) and relapsed (N = 17) acute myeloid leukaemia, after a median of 3 (2–5) prior regimens. Grade 4 myelosuppression was observed in all cases, with two patients dying of bacterial sepsis. Nine patients achieved a complete remission. Disease status, number of prior therapies, and cytogenetic aberrations were not associated with the outcome. However, remission was only achieved with Ara-C at 2 g/m2/day and not 1 g/m2/day (9/15 versus 0/4, P = 0.03)
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