11 research outputs found

    Examining Ecological Constraints on the Intergenerational Transmission of Attachment Via Individual Participant Data Meta-analysis

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    Parents\u2019 attachment representations and child\u2013parent attachment have been shown to be associated, but these associations vary across populations (Verhage et al., 2016). The current study examined whether ecological factors may explain variability in the strength of intergenerational transmission of attachment, using individual participant data (IPD) meta-analysis. Analyses on 4,396 parent\u2013child dyads (58 studies, child age 11\u201396 months) revealed a combined effect size of r =.29. IPD meta-analyses revealed that effect sizes for the transmission of autonomous-secure representations to secure attachments were weaker under risk conditions and weaker in adolescent parent\u2013child dyads, whereas transmission was stronger for older children. Findings support the ecological constraints hypothesis on attachment transmission. Implications for attachment theory and the use of IPD meta-analysis are discusse

    Conceptual comparison of constructs as first step in data harmonization: Parental sensitivity, child temperament, and social support as illustrations

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    This article presents a strategy for the initial step of data harmonization in Individual Participant Data syntheses, i.e., making decisions as to which measures operationalize the constructs of interest - and which do not. This step is vital in the process of data harmonization, because a study can only be as good as its measures. If the construct validity of the measures is in question, study results are questionable as well. Our proposed strategy for data harmonization consists of three steps. First, a unitary construct is defined based on the existing literature, preferably on the theoretical framework surrounding the construct. Second, the various instruments used to measure the construct are evaluated as operationalizations of this construct, and retained or excluded based on this evaluation. Third, the scores of the included measures are recoded on the same metric. We illustrate the use of this method with three example constructs focal to the Collaboration on Attachment Transmission Synthesis (CATS) study: parental sensitivity, child temperament, and social support. This process description may aid researchers in their data pooling studies, filling a gap in the literature on the first step of data harmonization. • Data harmonization in studies using combined datasets is of vital importance for the validity of the study results. • We have developed and illustrated a strategy on how to define a unitary construct and evaluate whether instruments are operationalizations of this construct as the initial step in the harmonization process. • This strategy is a transferable and reproducible method to apply to the data harmonization process

     Half dicht, half prose gheordineert  : vers et prose de moyen français en moyen nÊerlandais

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    In both French-speaking and Dutch-speaking literary cultures of the late Middle Ages, competition between poets produced a collective poetic expertise. To what extent, then, can such competition be identified across the two cultures, in translations of verse or prosimetrum compositions from Middle French into Middle Dutch? An examination of the Dutch translations reveals that verse is both a means to knowledge and an object of knowledge, in the target culture as well as the source culture. The diversity of translations shows that verse is not only a system that translators attempt to master, but also a formal supplement in ways that are unavailable to prose

    The thiol antioxidant 1,2-dithiole-3-thione stimulates the expression of heat shock protein 70 in dopaminergic PC12 cells

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    In Parkinson's disease (PD), the pathogenic factors oxidative stress and protein aggregation interact and culminate in the apoptotic death of (mainly catecholaminergic) neurons. The dithiolethiones comprise thiol antioxidants that are well known for their activation of the expression of a wide collection of cytoprotective genes, including genes coding for antioxidant enzymes. Given the observation that heat shock proteins (HSPs), in particular the heat shock protein 72 (HSP72), protects against cellular degeneration in various models of PD, the ability of the unsubstituted dithiolethione 1,2-dithiole-3-thione (D3T) to stimulate heat shock protein gene and protein expression was studied using the dopaminergic PC12 cell line. As anticipated, D3T stimulated the expression of the antioxidant enzyme NAD(P)H:quinone oxidoreductase 1 (NQO1). Quantitative PCR analysis revealed that D3T stimulates the expression of the inducible, cytoplasmic HSP72. Moreover, D3T strongly potentiated HSP72 gene and protein expression in heat-stressed cells. Taken together, our data show that, in addition to antioxidant enzymes, D3T stimulates the expression of HSP72, a chaperone shown to be neuroprotective in various models of PD, in particular under conditions of cellular stress. Thus, the broad range manipulation of endogenous cellular defense mechanisms, through D3T, may represent an innovative approach to therapeutic intervention in PD

    The antioxidant anethole dithiolethione inhibits monoamine oxidase-B but not monoamine oxidase A activity in extracts of cultured astrocytes

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    Anethole dithiolethione (ADT) is a clinically available, pluripotent antioxidant proposed as a neuroprotectant for Parkinson's disease (PD). Here, using extracts from cultured astrocytes, containing both monoamine oxidase (MAO) A and B activity, we demonstrate that ADT concentration-dependently inhibits MAO-B activity in a clinically relevant concentration range (0.03-30 microM, IC-50 = 0.5 microM) without affecting MAO A activity. Considering the alleged contribution of MAO activity in general, and MAO-B in particular, to oxidative stress and neurodegeneration in PD, our data further support the neuroprotective potential of ADT

    The blood clotting Factor XIIIa forms unique complexes with amyloid-beta (A) and colocalizes with deposited A in cerebral amyloid angiopathy

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    Aims Cerebral amyloid angiopathy (CAA) is a key pathological hallmark of Alzheimer's disease (AD) characterized by accumulation of amyloid‐beta (Aβ) protein in blood vessel walls. CAA impairs vessel functioning, affects blood brain barrier integrity and accelerates cognitive decline of AD patients. Unfortunately, mechanisms underlying Aβ deposition in the vessel wall remain largely unknown. Factor XIIIa (FXIIIa) is a blood‐derived transglutaminase crucial in blood coagulation by cross‐linking fibrin molecules. Evidence is mounting that blood‐derived factors are present in CAA and may play a role in protein deposition in the vessel wall. We therefore investigated whether FXIIIa is present in CAA and if FXIIIa cross‐link activity affects Aβ aggregation. Methods Using immunohistochemistry, we investigated the distribution of FXIIIa, its activator thrombin and in situ FXIIIa activity in CAA in post‐mortem AD tissue. We used surface plasmon resonance and Western blot analysis to study binding of FXIIIa to Aβ and the formation of FXIIIa‐Aβ complexes, respectively. In addition, we studied cytotoxicity of FXIIIa‐Aβ complexes to cerebrovascular cells. Results FXIIIa, thrombin and in situ FXIIIa activity colocalize with the Aβ deposition in CAA. Furthermore, FXIIIa binds to Aβ with a higher binding affinity for Aβ1–42 compared with Aβ1–40. Moreover, highly stable FXIIIa‐Aβ complexes are formed independently of FXIIIa cross‐linking activity that protected cerebrovascular cells from Aβ‐induced toxicity in vitro. Conclusions Our data showed that FXIIIa colocalizes with Aβ in CAA and that FXIIIa forms unique protein complexes with Aβ that might play an important role in Aβ deposition and persistence in the vessel wall

    Development of carbon-11 labeled acryl amides for selective PET imaging of active tissue transglutaminase

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    Introduction Tissue transglutaminase (TG2) is a ubiquitously expressed enzyme capable of forming metabolically and mechanically stable crosslinks between the γ-carboxamide of a glutamine acyl-acceptor substrate and the ε-amino functionality of a lysine acyl-donor substrate resulting in protein oligomers. High TG2 crosslinking activity has been implicated in the pathogenesis of various diseases including celiac disease, cancer and fibrotic and neurodegenerative diseases. Development of a PET tracer specific for active TG2 provides a novel tool to further investigate TG2 biology in vivo in disease states. Recently, potent irreversible active site TG2 inhibitors carrying an acrylamide warhead were synthesized and pharmacologically characterized. Methods Three of these inhibitors, compound 1, 2 and 3, were successfully radiolabeled with carbon-11 on the acrylamide carbonyl position using a palladium mediated [11C]CO aminocarbonylation reaction. Ex vivo biodistribution and plasma stability were evaluated in healthy Wistar rats. Autoradiography was performed on MDA-MB-231 tumor sections. Results [11C]1, -2 and -3 were obtained in decay corrected radiochemical yields of 38–55%. Biodistribution showed low uptake in peripheral tissues, with the exception of liver and kidney. Low brain uptake of < 0.05% ID/g was observed. Blood plasma analysis demonstrated that [11C]1 and [11C]2 were rapidly metabolized, whereas [11C]3 was metabolized at a more moderate rate (63.2 ± 6.8 and 28.7 ± 10.8% intact tracer after 15 and 45 min, respectively). Autoradiography with [11C]3 on MDA-MB-231 tumor sections showed selective and specific binding of the radiotracer to the active state of TG2. Conclusions Taken together, these results identify [11C]3 as the most promising of the three compounds tested for development as PET radiotracer for the in vivo investigation of TG2 activity

    The latent structure of the adult attachment interview: Large sample evidence from the collaboration on attachment transmission synthesis

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    The Adult Attachment Interview (AAI) is a widely used measure in developmental science that assesses adults' current states of mind regarding early attachment-related experiences with their primary caregivers. The standard system for coding the AAI recommends classifying individuals categorically as having an autonomous, dismissing, preoccupied, or unresolved attachment state of mind. However, previous factor and taxometric analyses suggest that: (a) adults' attachment states of mind are captured by two weakly correlated factors reflecting adults' dismissing and preoccupied states of mind and (b) individual differences on these factors are continuously rather than categorically distributed. The current study revisited these suggestions about the latent structure of AAI scales by leveraging individual participant data from 40 studies (N = 3,218), with a particular focus on the controversial observation from prior factor analytic work that indicators of preoccupied states of mind and indicators of unresolved states of mind about loss and trauma loaded on a common factor. Confirmatory factor analyses indicated that: (a) a 2-factor model with weakly correlated dismissing and preoccupied factors and (b) a 3-factor model that further distinguished unresolved from preoccupied states of mind were both compatible with the data. The preoccupied and unresolved factors in the 3-factor model were highly correlated. Taxometric analyses suggested that individual differences in dismissing, preoccupied, and unresolved states of mind were more consistent with a continuous than a categorical model. The importance of additional tests of predictive validity of the various models is emphasized
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