Relevance of the regional lymph node in scrapie pathogenesis after peripheral infection of hamsters

<p>Abstract</p> <p>Background</p> <p>The exact role of the lymphoreticular system in the spread of peripheral prion infections to the central nervous system still needs further elucidation. Against this background, the influence of the regional lymph node <it>(Ln. popliteus</it>) on the pathogenesis of scrapie was monitored in a hamster model of prion infection <it>via </it>the footpad.</p> <p>Methods</p> <p>Surgical lymphadenectomy was carried out at different time points after infection, or prior to inoculation, in order to elucidate the impact of the lymph node on lethal neuroinvasion.</p> <p>Results</p> <p>The <it>Ln. popliteus </it>did not show an influence on pathogenesis when a high dose of infectivity was administered. However, it was found to modulate the interval of time until the development of terminal scrapie in a subset of animals lymphadenectomized after low-dose infection. In additon, lymphadenectomy performed four weeks before inoculation prevented cerebral PrP^TSEdeposition and development of disease during the period of observation (314 days) in the majority of hamsters challenged with a very low dose of scrapie agent.</p> <p>Conclusion</p> <p>Our findings suggest the regional lymph node as a potentially facilitating or even essential factor for invasion of the brain after peripheral challenge with low doses of infectious scrapie agent. The invasive <it>in vivo </it>approach pursued in this study may be applied also to other animal species for further elucidating the involvement of lymphoid tissue in the pathogenesis of experimental and natural TSEs.</p

Synthesis and properties of perfluoroalkyl groups containing double four-ring spherosilicate (siloxysilsesquioxane) precursors

Organically modified cage-like double four-ring spherosilicates have received considerable interest in the construction of nanosized hybrid materials, as well as building units for structural well-defined polymers. This group is extended by perfluoroalkyl ligands containing spherosilicates, synthesized by addition reaction of the octahydridodimethlysiloxyoctasilsesquioxane [H(CH3)2Si]8Si8O20 and heptadecafluorodecyl methacrylate. The resultant liquid spherosilicate substituted with eight terminal perfluoroalkyl groups was characterized by 29 and 13C NMR spectroscopies and MALDI Time-of-Flight mass spectrometry. Partial substitution of perfluoroalkyl ligands by trimethoxysilyl containing groups provides condensable precursors for the synthesis of hydrophobic and oleophobic materials via the sol-gel process. This new spherosilicate, carrying on average four perfluoroalkyl groups and four trimethoxysilyl groups shows better hydrophobic and oleophobic properties compared with commonly used perfluoroalkyltrialkoxysilanes under identical concentration of perfluoroalkyl chains. In addition a comprehensive literature survey is given on structural well characterized, organically modified cage-like double four-ring spherosilicates

Long-Term Effects of Cold Atmospheric Plasma-Treated Water on the Antioxidative System of Hordeum vulgare

Facing climate change, the development of innovative agricultural technologies securing food production becomes increasingly important. Plasma-treated water (PTW) might be a promising tool to enhance drought stress tolerance in plants. Knowledge about the effects of PTW on the physiology of plants, especially on their antioxidative system on a long-term scale, is still scarce. In this work, PTW was applied to barley leaves (Hordeum vulgare cv. Kosmos) and various constituents of the plants’ antioxidative system were analyzed 30 days after treatment. An additional drought stress was performed after foliar PTW application followed by a recovery period to elucidate whether PTW treatment improved stress tolerance. Upon PTW treatment, the Total Antioxidant Capacity (TAC) in leaves and roots was lower in comparison to deionized water treated plants. In contrast, PTW treatment caused a higher content of chlorophyll, quantum yield and total ascorbate content in leaves compared to deionized water treated plants. After additional drought application and subsequent recovery period, an enhancement of values for TAC, contents of malondialdehyde, glutathione as well as activity of ascorbate peroxidase indicated a possible upregulation of antioxidative properties in roots. Hydrogen peroxide and nitric oxide might mediate abiotic stress tolerance and are considered as key components of PTW

Einflussnahmen der extremen Rechten auf die Soziale Arbeit in Mecklenburg-Vorpommern

Sowohl in Deutschland als auch in ganz Europa ist seit einigen Jahren ein wachsender Trend zu autoritären, demokratie- und menschenfeindlichen Denk- und Handlungsweisen zu verzeichnen. Trotz einer angenommenen hohen Sensibilität gegenüber solchen Positionen ist eine Einflussnahme auch auf die Soziale Arbeit und ihre Akteure nicht ausgeschlossen. Die Studie "Die extreme Rechte in der Sozialen Arbeit in MV" (Laufzeit 06/2020-07/2021) untersucht die Versuche der Einflussnahme extrem rechter Diskurse und Akteure auf die bzw. innerhalb der Sozialen Arbeit in Mecklenburg-Vorpommern systematisch mithilfe eines Mixed-Methods-Ansatzes. Der Artikel stellt die Ergebnisse der Studie sowie ihre methodische Umsetzung dar und analysiert die empirischen Zugänge und methodischen Möglichkeiten der Wissenschaft Sozialer Arbeit in Hinblick auf eigene Beiträge zur Rechtsextremismusforschung.Both in Germany and throughout Europe, there has been a growing trend towards authoritarian, anti-democratic and anti-human ways of thinking and acting for some years now. Despite an assumed high sensitivity towards such positions, an influence on social work and its professionals cannot be ruled out. The study "The far right in social work in Mecklenburg-Western Pomerania" (06/2020-07/2021) systematically investigates the attempts of far right discourses and actions to influence social work in Mecklenburg-Western Pomerania using a mixed methods approach. The article presents the results of the study as well as its methodological implementation. Furthermore, it analyses the empirical approaches and methodological possibilities of social work with regard to its own contributions to right-wing extremism research

The German version of the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5): psychometric properties and diagnostic utility

Background: The Posttraumatic Stress Disorder (PTSD) Checklist (PCL, now PCL-5) has recently been revised to reflect the new diagnostic criteria of the disorder. Methods: A clinical sample of trauma-exposed individuals (N = 352) was assessed with the Clinician Administered PTSD Scale for DSM-5 (CAPS-5) and the PCL-5. Internal consistencies and test-retest reliability were computed. To investigate diagnostic accuracy, we calculated receiver operating curves. Confirmatory factor analyses (CFA) were performed to analyze the structural validity. Results: Results showed high internal consistency (α = .95), high test-retest reliability (r = .91) and a high correlation with the total severity score of the CAPS-5, r = .77. In addition, the recommended cutoff of 33 on the PCL-5 showed high diagnostic accuracy when compared to the diagnosis established by the CAPS-5. CFAs comparing the DSM-5 model with alternative models (the three-factor solution, the dysphoria, anhedonia, externalizing behavior and hybrid model) to account for the structural validity of the PCL-5 remained inconclusive. Conclusions: Overall, the findings show that the German PCL-5 is a reliable instrument with good diagnostic accuracy. However, more research evaluating the underlying factor structure is needed

Expression and localization of nuclear proteins in autosomal-dominant Emery-Dreifuss muscular dystrophy with LMNA R377H mutation

BACKGROUND: The autosomal dominant form of Emery-Dreifuss muscular dystrophy (AD-EDMD) is caused by mutations in the gene encoding for the lamins A and C (LMNA). Lamins are intermediate filament proteins which form the nuclear lamina underlying the inner nuclear membrane. We have studied the expression and the localization of nuclear envelope proteins in three different cell types and muscle tissue of an AD-EDMD patient carrying a point mutation R377H in the lamin A/C gene. RESULTS: Lymphoblastoid cells, skin fibroblasts, primary myoblasts and muscle thin sections were studied by immunocytochemistry and electron microscopy. Cellular levels of A-type lamins were reduced compared to control cells. In contrast, the amount of emerin and lamin B appeared unaltered. Cell synchronization experiments showed that the reduction of the cellular level of A-type lamin was due to instability of lamin A. By electron microscopy, we identified a proportion of nuclei with morphological alterations in lymphoblastoid cells, fibroblasts and mature muscle fibres. Immunofluorescence microscopy showed that a major population of the lamin B receptor (LBR), an inner nuclear membrane protein, was recovered in the cytoplasm in association with the ER. In addition, the intranuclear organization of the active form of RNA polymerase II was markedly different in cells of this AD-EDMD patient. This aberrant intranuclear distribution was specifically observed in muscle cells where the pathology of EDMD predominates. CONCLUSIONS: From our results we conclude: Firstly, that structural alterations of the nuclei which are found only in a minor fraction of lymphoblastoid cells and mature muscle fibres are not sufficient to explain the clinical pathology of EDMD; Secondly, that wild type lamin A is required not only for the retention of LBR in the inner nuclear membrane but also for a correct localization of the transcriptionally active RNA pol II in muscle cells. We speculate that a rearrangement of the internal chromatin could lead to muscle-specific disease symptoms by interference with proper mRNA transcription

factor structure and symptom profiles

Background: The proposed ICD-11 criteria for trauma-related disorders define posttraumatic stress disorder (PTSD) and complex posttraumatic stress disorder (cPTSD) as separate disorders. Results of previous studies support the validity of this concept. However, due to limitations of existing studies (e.g. homogeneity of the samples), the present study aimed to test the construct validity and factor structure of cPTSD and its distinction from PTSD using a heterogeneous trauma-exposed sample. Method: Confirmatory factor analyses (CFAs) were conducted to explore the factor structure of the proposed ICD-11 cPTSD diagnosis in a sample of 341 trauma-exposed adults (n = 191 female, M = 37.42 years, SD = 12.04). In a next step, latent profile analyses (LPAs) were employed to evaluate predominant symptom profiles of cPTSD symptoms. Results: The results of the CFA showed that a six-factor structure (i.e. symptoms of intrusion, avoidance, hyperarousal and symptoms of affective dysregulation, negative self-concept, and interpersonal problems) fits the data best. According to LPA, a four-class solution optimally characterizes the data. Class 1 represents moderate PTSD and low symptoms in the specific cPTSD clusters (PTSD group, 30.4%). Class 2 showed low symptom severity in all six clusters (low symptoms group, 24.1%). Classes 3 and 4 both exhibited cPTSD symptoms but differed with respect to the symptom severity (Class 3: cPTSD, 34.9% and Class 4: severe cPTSD, 10.6%). Conclusions: The findings replicate previous studies supporting the proposed factor structure of cPTSD in ICD-11. Additionally, the results support the validity and usefulness of conceptualizing PTSD and cPTSD as discrete mental disorders

Production of Toxic Volatile Trimethylbismuth by the Intestinal Microbiota of Mice

The biotransformation of metals and metalloids into their volatile methylated derivatives by microbes growing under anaerobic conditions (e.g., the mammalian intestinal microbiota) plays an important role in spreading these compounds in the environment. In this paper, we could show that the presence of an intact intestinal microbiota of mice provides the conditio sine qua non for the production of these mostly toxic derivatives. To document the indispensible role of the intestinal microbiota in methylating metals and metalloids to volatile derivatives under in vivo conditions, we compared the methylation capability of conventionally raised (CONV) and germ-free (GF) B6-mice fed with chow containing colloidal bismuth subcitrate (CBS) as the starting material for the formation of volatile methylated metal(loid)s. Permethylated volatile trimethylbismuth ((CH3)3Bi) was only detected in the blood of the conventionally raised mice. Concomitantly, a higher bismuth concentration was found in organs such as liver, lung, testicles, and brain of the CONV mice as compared to those of GF mice (P > 0.01), strongly suggesting a correlation between the intestinal biomethylation of bismuth and its accumulation in mammalian tissues

Математическое моделирование тепломассопереноса в канале с пористой вставкой

Выпускная квалификационная работа 105 с., 22 рис., 5 табл., 19 источников, 1 прил. Объект исследования - канал с пористым материалом, в том числе рабочая зона газогенератора. Цель работы – исследование процессов тепломассопереноса в канале, заполненном пористой вставкой, на основе математического моделирования. В работе использован пакет вычислительной гидродинамики FLUENT совместно с сеточным генератором GAMBIT. Установлены особенности использования различных приближений к математическому моделированию тепломассопереноса в каналах с пористыми вставками, а также показана возможность применения пакетов вычислительной гидродинамики для анализа термогидродинамических структур в канале газогенератора без учета влияния физико-химических особенностей процесса газификацииThe paper consists of 105 pp., 22 fig., 5 tab., 19 references, 1 appendix. The objects of study are the channel with porous material and the work area of the gasifier. The purpose of the work is heat and mass transfer processes study in the channel filled with porous insert based on mathematical modeling. CFD package FLUENT was used together with the finite element mesh generator GAMBIT. The features of the use of various approximations to the mathematical modeling of heat and mass transfer in porous inserts channels are specified. The possibility of using computational fluid dynamics package for the analysis of thermohydrodynamic structures in the channel of gasifier excluding the impact of physical and chemical characteristics of the gasification process is proved