Vaccination reshapes the virus-specific T cell repertoire in unexposed adults

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The role of the octarepeat region in neuroprotective function of the cellular prion protein

Structural alterations of the cellular prion protein (PrP(C)) seem to be the core of the pathogenesis of prion diseases. However, the physiological function of PrP(C )remains an enigma. Cell culture experiments have indicated that PrP(C) and in particular its N-terminal octarepeat region together with the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways have a fundamental involvement in neuroprotection and oxidative stress reactions. We used wild-type mice, PrP knockout (Prnp(-/-)) animals and transgenic mice that lack the octarepeat region (C4/-) and subjected them to controlled ischemia. We identified an increased cleavage and synthesis of PrP(C) in ischemic brain areas of wild-type mice compared with sham controls. The infarct size in Prnp(-/-) animals was increased threefold when compared with wild-type mice. The infarct size in C4/- animals was identical to Prnp(-/-) mice, that is, around three times larger than in wild-type mice. We showed that the PrP in C4/- mice does not functionally rescue the Prnp(-/-) phenotype; furthermore it is unable to undergo beta cleavage, although an increased amount of C1 fragments was found in ischemic brain areas compared with sham controls. We demonstrated that the N-terminal octarepeat region has a lead function in PrP(C) physiology and neuroprotection against oxidative stress in vivo.     

Subnuclear partitioning of rRNA genes between the nucleolus and nucleoplasm reflects alternative epiallelic states

Eukaryotes can have thousands of 45S ribosomal RNA (rRNA) genes, many of which are silenced during development. Using fluorescence-activated sorting techniques, we show that active rRNA genes in Arabidopsis thaliana are present within sorted nucleoli, whereas silenced rRNA genes are excluded. DNA methyltransferase (met1), histone deacetylase (hda6), or chromatin assembly (caf1) mutants that disrupt silencing abrogate this nucleoplasmic–nucleolar partitioning. Bisulfite sequencing data indicate that active nucleolar rRNA genes are nearly completely demethylated at promoter CGs, whereas silenced genes are nearly fully methylated. Collectively, the data reveal that rRNA genes occupy distinct but changeable nuclear territories according to their epigenetic state.     

Spectrum of mutations in gastrointestinal stromal tumor patients – a population‐based study from Slovakia

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of gastrointestinal tract and are characterized by presence of mutations in tyrosine kinases cKIT (KIT) and PDGFRα (PDGFRA). Mutations identified are highly heterogeneous, but some mutations are associated with specific clinical features of the tumor. Samples from 278 GIST patients collected during the period 2004–2011 were screened for mutations in exons 9, 11, 13, and 17 of KIT and 12, 14 and 18 of PDGFRA. Results of mutation screening were summarized and tested for possible association with clinical parameters of tumors. Mutations were identified in 83.81% of patients. Most frequent mutations were found in KIT exon 11 reaching frequency of 62.95%. Other exons contributed to the mutation pool with frequencies 8.27%, 7.55%, 2.52%, 1.44%, 1.08%, and 0.00%, in decreasing order KIT exon 9, PDGRFA exons 18 and 12, KIT exon 13, PDGFRA exon 14, and KIT exon 17. General linear model analysis showed no effect of any individual analyzed mutation on the phenotypic variables, but we confirmed association between mutations KIT exon 9 p. 503‐504_dup2, and PDGFRA exon 18 p. D842V and intestinal and gastric localization of tumors.     

Clinically significant symptom change in children with attention‐deficit/hyperactivity disorder: does it correspond with reliable improvement in functioning?

This study examined the relation between clinically significant (CS) change in symptoms of attention‐deficit/hyperactivity disorder (ADHD) and of oppositional defiant disorder (ODD), and reliable change in multiple domains of functioning in children who participated in the Multimodal Treatment Study of Children with ADHD. Children with CS change in symptoms were significantly more likely than children without CS change to have reliable change across five domains of functioning. Interestingly, however, depending on the measure of functioning, 14 to 52% of children who did not achieve CS change in symptoms showed reliable improvement in functional domains. The results have implications for the definition and measurement of CS change in child treatment‐outcome studies. © 2008 Wiley Periodicals, Inc. J Clin Psychol 65:1–18, 2009.     

Single particle adsorbing transfer system

Here we present a novel approach for horizontal transfer of single particles after laser microdissection. The developed technique is a single particle adsorbing system for highly selective and gentle horizontal transfer of microdissected fixed and living material. As mediated via low-pressure technology, the transfer process can be precisely controlled, thus facilitating horizontal particle transfer of any isolated material, e.g. tissue material, single cells or chromosomes, in addition to precise positioning for sample release. This collection method allows one to predefine target positions and enables material transfer without contamination to any planar microchip device. This contamination free transfer is indispensable for novel lab-on-a-chip systems performing nanoscale polymerase chain reaction analyses. Using virtual reaction chamber microdevices, small amounts of microdissected material—as little as one single cell—can be directly transmitted and immediately used for single cell analysis. Daniela Woide and Veronika Mayer contributed equally to this paper.     

Tolerability of N-chlorotaurine plus ammonium chloride in the rabbit and human eye - a phase 1 clinical study

Background  N-chlorotaurine (NCT), an endogenous mild antiseptic, is well-tolerated by application to the human conjunctiva and has been shown to offer beneficial effects in infectious conjunctivitis. Animal tests revealed improved efficacy of a combination of NCT with ammonium chloride in adenoviral conjunctivitis. The aim of this study was to evaluate the tolerability of NCT plus ammonium chloride in the healthy rabbit and human eye. Methods  First, a tolerability study was performed in rabbits. In a blinded and randomized fashion, one eye was treated with the test medication, the other one with 0.9% saline. Twenty-one animals (three per concentration) were treated with one drop every 2 hours for 6 days. Second, in two volunteers one drop of a defined concentration was applied to one eye every 15 min for 1 hour, saline to the control eye. Four different concentrations were tested on different days. Third, a double-blind, randomized phase 1 study in 13 healthy volunteers was performed. One drop of 0.1% NCT plus 0.1% NH₄Cl versus saline was applied every 15 min within the first hour, followed by four drops every 2 hours. This regimen was done daily for 5 days. Results  In rabbits, no side effects were seen with 0.1% NCT plus 0.1% NH₄Cl, while higher concentrations sometimes caused short-time and minimal conjunctival injection and secretion after dosing. By 1% NCT plus 1% NH₄Cl, these effects were moderate, but disappeared again without any detectable residues. In the pilot study with two volunteers, treatment with 0.5% NCT plus 0.1% NH₄Cl caused medium-scale eye burning for 30 seconds, while 0.1% NCT plus 0.1% NH₄Cl was very well-tolerated, with no or minimal burning for a few seconds. In the subsequent phase 1 study, 0.1% NCT plus 0.1% NH₄Cl was well-tolerated by all subjects except for minimal eye burning for a few seconds after dropping. No objective signs of eye changes could be detected in the human beings. Conclusion  The results of this study clearly demonstrate the good tolerability of a promising NCT formulation with improved activity.     

Tolerance of N-chlorotaurine, a new antimicrobial agent, in infectious conjunctivitis - a phase II pilot study

N-Chlorotaurine (NCT) is an endogenous microbicidal oxidant. This open pilot study (phase IIa) with 9 patients was done to gain first knowledge on the tolerance of NCT in infectious conjunctivitis. By application of 1% NCT 5 times a day, no adverse effects could be observed. All 6 subjects with bacterial conjunctivitis were cured within 3-5 days. Two subjects with epidemic keratoconjunctivitis were treated for 7-10 days and 1 subject with herpes simplex blepharitis for 3 days with no rapid improvement but probable mitigation of inflammation. Therefore, NCT seems to be useful in the treatment of infectious conjunctivitis, and further investigation on its therapeutic efficacy is suggested.     

In vitro receptor screening of pure constituents of St. John's wort reveals novel interactions with a number of GPCRs

RATIONALE: Hypericum perforatum L. (St. John's wort; SJW) is one of the leading psychotherapeutic phytomedicines and great effort has been devoted to clarifying its mechanism of action. OBJECTIVE: We have undertaken a comprehensive analysis of several pure compounds isolated from the crude extract to gain further insight into the molecular actions of various substituents of SJW. METHODS: We characterized the in vitro pharmacology of the naphthodianthrones hypericin and pseudohypericin, the phloroglucinol derivative hyperforin, and several flavonoids at 42 biogenic amine receptors and transporters using the resources of the National Institute of Mental Health Psychoactive Drug Screening Program. RESULTS: The biflavonoid amentoflavone significantly inhibited binding at serotonin (5-HT(1D), 5-HT(2C)), D(3)-dopamine, delta-opiate, and benzodiazepine receptors. The naphthodianthrone hypericin had significant activity at D(3)- and D(4)-dopamine receptors and beta-adrenergic receptors. With the exception of the D(1)-dopamine receptor, the phloroglucinol derivative hyperforin was less active than other SJW constituents tested on all screened receptors. CONCLUSION: Our present in vitro data clearly show that several pure substances in SJW are potential CNS psychoactive agents and may contribute to the antidepressant efficacy of the plant in a complex manner. Our data also reveal novel and heretofore unexpected interactions of pure compounds in SJW at a number of GPCRs, transporters, and ion channels. We hypothesize that additive or synergistic actions of different single compounds may be responsible for the antidepressant efficacy of SJW. These results and this general approach may impact our understanding of phytomedicines in general and H. perforatum specifically.