On the impact of electrolyte temperature on contact glow discharge electrolysis

This study aims at disclosing the effect of small temperature drops (10-15 degrees C) of the electrolyte on Contact Glow Discharge Electrolysis (CGDE). In our experiments, we measure the temperature change of electrolyte and electrode as well as the change in current following on from the addition of, first, frozen and, second, boiling KOH aqueous solution (0.1 M). Quite surprisingly, only the addition of frozen KOH aqueous solution has a significant impact on current (+130%), caused by the decrease in electrolyte temperature (-11 degrees C). In contrast, the addition of boiling KOH aqueous solution has a negligible effect on current. A very similar behavior is recorded when frozen or boiling type III deionized water is used: the addition of ice has an even stronger impact on current (+145 %) and on electrolyte temperature (-14 degrees C), while adding boiling water has no measurable effect. Thus, we here demonstrated that electrolyte temperature is critical for managing the responsiveness of the CGDE system. Our results pave the way toward temperature controlled CGDE, a powerful tool for a greener and a more efficient environmental chemistry

Generalized and specific anxiety in adolescents following heart transplant

Mental health concerns are associated with worse outcomes after adult heart transplant. Illness‐specific anxiety is associated with worsened psychological well‐being after other solid organ transplants but has never been characterized after pediatric heart transplant. This single‐center cross‐sectional study aimed to evaluate illness‐specific and generalized anxiety after heart transplantation in adolescents. A novel 12‐item PHTF, GAD‐7, and the PedsQL were administered. Univariate associations of demographics, clinical features, and medication adherence as measured by immunosuppression standard deviation with the PHTF and GAD‐7 scores were evaluated. Internal consistency and validity of the PHTF were examined. In total, 30 patients participated. The most common illness‐specific fears were retransplantation, rejection, and more generally post‐transplant complications. The PHTF had good internal consistency (Cronbach α = .88). Construct validity was demonstrated between PHTF and GAD‐7 (r = .62) and PedsQL (r = −.54 to −.62). 23% endorsed moderate to severe generalized anxiety symptoms. More severe symptoms were associated with older age at survey (P = .03), older age at listing (P = .01) and having post‐transplant complications (P = .004). Patients with moderate or severe symptoms were more likely to report late immunosuppression doses (P = .004). Illness‐specific and generalized anxiety may be prevalent after pediatric heart transplant. Screening for anxiety in adolescents post‐transplant may identify those at risk for adverse outcomes including non‐adherence. The PHTF is a brief, valid, and reliable instrument identifying illness‐specific anxiety in this population.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153669/1/petr13647.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153669/2/petr13647_am.pd

Generation and Characterization of Rat and Mouse Monoclonal Antibodies Specific for MeCP2 and Their Use in X-Inactivation Studies

Methyl CpG binding protein 2 (MeCP2) binds DNA, and has a preference for methylated CpGs and, hence, in cells, it accumulates in heterochromatin. Even though it is expressed ubiquitously MeCP2 is particularly important during neuronal maturation. This is underscored by the fact that in Rett syndrome, a neurological disease, 80% of patients carry a mutation in the MECP2 gene. Since the MECP2 gene lies on the X chromosome and is subjected to X chromosome inactivation, affected patients are usually chimeric for wild type and mutant MeCP2. Here, we present the generation and characterization of the first rat monoclonal MeCP2 specific antibodies as well as mouse monoclonal antibodies and a rabbit polyclonal antibody. We demonstrate that our antibodies are suitable for immunoblotting, (chromatin) immunoprecipitation and immunofluorescence of endogenous and ectopically expressed MeCP2. Epitope mapping revealed that most of the MeCP2 monoclonal antibodies recognize the C-terminal domain and one the N-terminal domain of MeCP2. Using slot blot analysis, we determined a high sensitivity of all antibodies, detecting amounts as low as 1 ng of MeCP2 protein. Moreover, the antibodies recognize MeCP2 from different species, including human, mouse, rat and pig. Lastly, we have validated their use by analyzing and quantifying X chromosome inactivation skewing using brain tissue of MeCP2 heterozygous null female mice. The new MeCP2 specific monoclonal antibodies described here perform well in a large variety of immunological applications making them a very valuable set of tools for studies of MeCP2 pathophysiology in situ and in vitro

Recognition of 5-Hydroxymethylcytosine by the Uhrf1 SRA Domain

Recent discovery of 5-hydroxymethylcytosine (5hmC) in genomic DNA raises the question how this sixth base is recognized by cellular proteins. In contrast to the methyl-CpG binding domain (MBD) of MeCP2, we found that the SRA domain of Uhrf1, an essential factor in DNA maintenance methylation, binds 5hmC and 5-methylcytosine containing substrates with similar affinity. Based on the co-crystal structure, we performed molecular dynamics simulations of the SRA:DNA complex with the flipped cytosine base carrying either of these epigenetic modifications. Our data indicate that the SRA binding pocket can accommodate 5hmC and stabilizes the flipped base by hydrogen bond formation with the hydroxyl group

Linear ensemble-coding in midbrain superior colliculus specifies the saccade kinematics

Recently, we proposed an ensemble-coding scheme of the midbrain superior colliculus (SC) in which, during a saccade, each spike emitted by each recruited SC neuron contributes a fixed minivector to the gaze-control motor output. The size and direction of this ‘spike vector’ depend exclusively on a cell’s location within the SC motor map (Goossens and Van Opstal, in J Neurophysiol 95: 2326–2341, 2006). According to this simple scheme, the planned saccade trajectory results from instantaneous linear summation of all spike vectors across the motor map. In our simulations with this model, the brainstem saccade generator was simplified by a linear feedback system, rendering the total model (which has only three free parameters) essentially linear. Interestingly, when this scheme was applied to actually recorded spike trains from 139 saccade-related SC neurons, measured during thousands of eye movements to single visual targets, straight saccades resulted with the correct velocity profiles and nonlinear kinematic relations (‘main sequence properties– and ‘component stretching’) Hence, we concluded that the kinematic nonlinearity of saccades resides in the spatial-temporal distribution of SC activity, rather than in the brainstem burst generator. The latter is generally assumed in models of the saccadic system. Here we analyze how this behaviour might emerge from this simple scheme. In addition, we will show new experimental evidence in support of the proposed mechanism

Niemann-Pick disease type C

Niemann-Pick C disease (NP-C) is a neurovisceral atypical lysosomal lipid storage disorder with an estimated minimal incidence of 1/120 000 live births. The broad clinical spectrum ranges from a neonatal rapidly fatal disorder to an adult-onset chronic neurodegenerative disease. The neurological involvement defines the disease severity in most patients but is typically preceded by systemic signs (cholestatic jaundice in the neonatal period or isolated spleno- or hepatosplenomegaly in infancy or childhood). The first neurological symptoms vary with age of onset: delay in developmental motor milestones (early infantile period), gait problems, falls, clumsiness, cataplexy, school problems (late infantile and juvenile period), and ataxia not unfrequently following initial psychiatric disturbances (adult form). The most characteristic sign is vertical supranuclear gaze palsy. The neurological disorder consists mainly of cerebellar ataxia, dysarthria, dysphagia, and progressive dementia. Cataplexy, seizures and dystonia are other common features. NP-C is transmitted in an autosomal recessive manner and is caused by mutations of either the NPC1 (95% of families) or the NPC2 genes. The exact functions of the NPC1 and NPC2 proteins are still unclear. NP-C is currently described as a cellular cholesterol trafficking defect but in the brain, the prominently stored lipids are gangliosides. Clinical examination should include comprehensive neurological and ophthalmological evaluations. The primary laboratory diagnosis requires living skin fibroblasts to demonstrate accumulation of unesterified cholesterol in perinuclear vesicles (lysosomes) after staining with filipin. Pronounced abnormalities are observed in about 80% of the cases, mild to moderate alterations in the remainder ("variant" biochemical phenotype). Genotyping of patients is useful to confirm the diagnosis in the latter patients and essential for future prenatal diagnosis. The differential diagnosis may include other lipidoses; idiopathic neonatal hepatitis and other causes of cholestatic icterus should be considered in neonates, and conditions with cerebellar ataxia, dystonia, cataplexy and supranuclear gaze palsy in older children and adults. Symptomatic management of patients is crucial. A first product, miglustat, has been granted marketing authorization in Europe and several other countries for specific treatment of the neurological manifestations. The prognosis largely correlates with the age at onset of the neurological manifestations

Heterochromatin and the molecular mechanisms of 'parent-of-origin' effects in animals.

Twenty five years ago it was proposed that conserved components of constitutive heterochromatin assemble heterochromatinlike complexes in euchromatin and this could provide a general mechanism for regulating heritable (cell-to-cell) changes in gene expressibility. As a special case, differences in the assembly of heterochromatin-like complexes on homologous chromosomes might also regulate the parent-of-origin-dependent gene expression observed in placental mammals. Here, the progress made in the intervening period with emphasis on the role of heterochromatin and heterochromatin-like complexes in parent-of-origin effects in animals is reviewed