35 research outputs found

    New Clathrin-Based Nanoplatforms for Magnetic Resonance Imaging

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    Background: Magnetic Resonance Imaging (MRI) has high spatial resolution, but low sensitivity for visualization of molecular targets in the central nervous system (CNS). Our goal was to develop a new MRI method with the potential for non-invasive molecular brain imaging. We herein introduce new bio-nanotechnology approaches for designing CNS contrast media based on the ubiquitous clathrin cell protein. Methodology/Principal Findings: The first approach utilizes three-legged clathrin triskelia modified to carry 81 gadolinium chelates. The second approach uses clathrin cages self-assembled from triskelia and designed to carry 432 gadolinium chelates. Clathrin triskelia and cages were characterized by size, structure, protein concentration, and chelate and gadolinium contents. Relaxivity was evaluated at 0.47 T. A series of studies were conducted to ascertain whether fluorescent-tagged clathrin nanoplatforms could cross the blood brain barriers (BBB) unaided following intranasal, intravenous, and intraperitoneal routes of administration. Clathrin nanoparticles can be constituted as triskelia (18.5 nm in size), and as cages assembled from them (55 nm). The mean chelate: clathrin heavy chain molar ratio was 27.0464.8: 1 fo

    Witnessing Violence Toward Siblings: An Understudied but Potent Form of Early Adversity

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    Research on the consequences of witnessing domestic violence has focused on inter-adult violence and most specifically on violence toward mothers. The potential consequences of witnessing violence to siblings have been almost entirely overlooked. Based on clinical experience we sought to test the hypothesis that witnessing violence toward siblings would be as consequential as witnessing violence toward mothers. The community sample consisted of unmedicated, right-handed, young adults who had siblings (n = 1,412; 62.7% female; 21.8±2.1 years of age). History of witnessing threats or assaults to mothers, fathers and siblings, exposure to parental and sibling verbal abuse and physical abuse, sexual abuse and sociodemographic factors were assessed by self-report. Symptoms of depression, anxiety, somatization, anger-hostility, dissociation and ‘limbic irritability’ were assessed by rating scales. Data were analyzed by multiple regression, with techniques to gauge relative importance; logistic regression to assess adjusted odds ratios for clinically-significant ratings; and random forest regression using conditional trees. Subjects reported witnessing violence to siblings slightly more often than witnessing violence to mothers (22% vs 21%), which overlapped by 51–54%. Witnessing violence toward siblings was associated with significant effects on all ratings. Witnessing violence toward mother was not associated with significant effects on any scale in these models. Measures of the relative importance of witnessing violence to siblings were many fold greater than measures of importance for witnessing violence towards mothers or fathers. Mediation and structural equation models showed that effects of witnessing violence toward mothers or fathers were predominantly indirect and mediated by changes in maternal behavior. The effects of witnessing violence toward siblings were more direct. These findings suggest that greater attention be given to the effects of witnessing aggression toward siblings in studies of domestic violence, abuse and early adversity

    Новa нанотехнологијa на бази клатрина за пренос великих протеинских молекула у централни нервни систем

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    Antibodies (Abs) have great promise for detection and treatment of central nervous system (CNS) disorders. However, the blood-brain barrier (BBB) is a major impediment to effective delivery. Only 0.1% of plasma Abs enter the CNS naturally via diffusion through a compromised BBB or via BBB saturation and CNS concentrations may still be insufficient for therapeutic efficacy. Moreover, Abs may take days to diffuse only a few millimeters and intracellular targets are not easily accessible to Abs. Thus, new, efficient, and noninvasive strategies are required for transporting large molecules like Abs into the CNS and inside targeted cells. Here we tested the hypothesis that clathrin, a coat protein naturally used to transport molecules across biological barriers and within cells, could serve as a nanoplatform for high-efficiency delivery of antibodies and imaging agents to the CNS. Clathrin triskelia (17.7 nm in size) were modified to carry 81 gadolinium chelates or 25 fluorescent tags. Nanoplatforms were characterized by size, structure, protein concentration, chelate and gadolinium contents and nanoparticle relaxivity was evaluated at 0.47 T. Clathrin triskelia exhibited ionic relaxivity of 16 mM-1s-1, and molecular relaxivity of 1166 mM-1s-1. A series of studies were conducted to ascertain whether fluorescent-tagged clathrin nanoplatforms could cross the blood brain barrier. Clathrin nanoplatforms were able to cross or bypass the BBB without enhancements following intraperitoneal and intranasal administration in rats. To demonstrate specific targeting clathrin triskelia were modified with dopamine-3- receptor-antibody (D3R-Ab), as there are no small-molecule ligands that bind exclusively to D3 receptors. One molecule of D3R-Ab was attached per clathrin triskelion and antibody remained intact and immunoreactive after the nanoparticle preparation. Low doses (64 μg/ kg) of nanoparticles (42.3±14.8 nm) were delivered intranasally in rats. Three hours later intact D3R-Ab-triskelia nanoparticles were found in D3R-brain regions inside neurons, with the highest concentration detected in islands of Calleja /ventral pallidum (2753 ng/g or 17.2% ID/g) and nucleus accumbens (1028 ng/g). High nanoprobe concentrations (1062 ng/g) were also found in hippocampal cells that have high concentrations of D3- receptors in the cytoplasm, but low expression of D3-receptors on the cell membrane. Low concentrations were detected in the cerebellum (84 ng/g.) Nanoprobes were not detected in regions lacking D3 receptors. D3R-Abs delivered without clathrin intranasally did not enter the brain..

    Witnessing Violence Toward Siblings: An Understudied but Potent Form of Early Adversity

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    Research on the consequences of witnessing domestic violence has focused on inter-adult violence and most specifically on violence toward mothers. The potential consequences of witnessing violence to siblings have been almost entirely overlooked. Based on clinical experience we sought to test the hypothesis that witnessing violence toward siblings would be as consequential as witnessing violence toward mothers. The community sample consisted of unmedicated, righthanded, young adults who had siblings (n = 1,412; 62.7 % female; 21.862.1 years of age). History of witnessing threats or assaults to mothers, fathers and siblings, exposure to parental and sibling verbal abuse and physical abuse, sexual abuse and sociodemographic factors were assessed by self-report. Symptoms of depression, anxiety, somatization, anger-hostility, dissociation and ‘limbic irritability ’ were assessed by rating scales. Data were analyzed by multiple regression, with techniques to gauge relative importance; logistic regression to assess adjusted odds ratios for clinically-significant ratings; and random forest regression using conditional trees. Subjects reported witnessing violence to siblings slightly more often than witnessing violence to mothers (22 % vs 21%), which overlapped by 51–54%. Witnessing violence toward siblings was associated with significant effects on all ratings. Witnessing violence toward mother was not associated with significant effects on any scale in these models. Measures of the relative importance of witnessing violence to siblings were many fold greater than measures of importance for witnessing violence towards mothers or fathers. Mediation and structural equatio

    Beta weights and comparative ratios indicating the role of maternal verbal aggression in mediating the association between symptom ratings and witnessing threats or assaults to mothers.

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    <p>*p<0.05,</p><p>**p<0.01,</p>¥<p>p<0.001,</p>§<p>p<0.0001,</p>†<p>p<10<sup>−10</sup>.</p><p>DV – Dependent Variable, IV – Independent Variable, M – Mediator, SOS – Shared over simple effects index.</p

    Regression coefficients and 95% confidence intervals for the association between exposure to multiple forms of maltreatment and socioeconomic factors on psychiatric symptom ratings.

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    <p>*p<0.05,</p><p>**p<0.01,</p>¥<p>p<0.001,</p>§<p>p<0.0001,</p>†<p>p<10<sup>−15</sup>.</p><p>— Covariates were excluded from the final model if their degree of association with the dependent variable was weak (p>0.2).</p
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