The formation, function and regulation of amyloids: insights from structural biology.

Amyloid diseases are characterized by the accumulation of insoluble, ß-strand-rich aggregates. The underlying structural conversions are closely associated with cellular toxicity, but can also drive the formation of functional protein assemblies. In recent years, studies in the field of structural studies have revealed astonishing insights into the origins, mechanisms and implications of amyloid formation. Notably, high-resolution crystal structures of peptides in amyloid-like fibrils and prefibrillar oligomers have become available despite their challenging chemical nature. Nuclear magnetic resonance spectroscopy has revealed that dynamic local polymorphisms in the benign form of the prion protein affect the transformation into amyloid fibrils and the transmissibility of prion diseases. Studies of the structures and interactions of chaperone proteins help us to understand how the cellular proteostasis network is able to recognize different stages of aberrant protein folding and prevent aggregation. In this review, we will focus on recent developments that connect the different aspects of amyloid biology and discuss how understanding the process of amyloid formation and the associated defence mechanisms can reveal targets for pharmacological intervention that may become the first steps towards clinically viable treatment strategies.

Proxy assessment of patients before and after radiotherapy for brain metastases. Results of a prospective study using the DEGRO brain module.

PURPOSE: Proxies of patients with poor performance status could give useful information about the patients' quality of life (QoL). We applied a newly developed questionnaire in a prospective QoL study of patients undergoing radiotherapy for brain metastases in order to make the first move to validate this instrument, and we compared the results with scores obtained using validated patient-completed instruments. MATERIALS AND METHODS: From January 2007 to June 2010, 166 patients with previously untreated brain metastases were recruited at 14 centers in Germany and Austria. The EORTC-QLQ-C15-PAL and the brain module BN20 were used to assess QoL in patients at the start of treatment and 3 months later. At the same time points, 141 of their proxies estimated the QoL with the new DEGRO brain module (DBM), a ten-item questionnaire rating the general condition as well as functions and impairment by symptoms in areas relevant to patients with brain metastases. RESULTS: At 3 months, 85 of 141 patients (60%) with initial response by a proxy were alive. Sixty-seven of these patients (79% of 3-month survivors) and 65 proxies completed the second set of questionnaires. After 3 months, QoL significantly deteriorated in all items of proxy-assessed QoL except headache. Correlations between self-assessed and proxy-assessed QoL were high in single items such as nausea, headache, and fatigue. CONCLUSIONS: The high correlation between self-assessment and proxy ratings as well as a similar change over time for both approaches suggest that in patients with brain metastases, proxy assessment using the DBM questionnaire can be an alternative approach to obtaining QoL data when patients are unable to complete questionnaires themselves. Our self-constructed and first applied DBM is the only highly specific instrument for patients with brain metastases, but further tests are needed for its final validation.

The nucleolus functions as a phase-separated protein quality control compartment.

The nuclear proteome is rich in stress-sensitive proteins, which suggests that effective protein quality control mechanisms are in place to ensure conformational maintenance. We investigated the role of the nucleolus in this process. In mammalian tissue culture cells under stress conditions, misfolded proteins entered the granular component (GC) phase of the nucleolus. Transient associations with nucleolar proteins such as NPM1 conferred low mobility to misfolded proteins within the liquid-like GC phase, avoiding irreversible aggregation. Refolding and extraction of proteins from the nucleolus during recovery from stress was Hsp70-dependent. The capacity of the nucleolus to store misfolded proteins was limited, and prolonged stress led to a transition of the nucleolar matrix from liquid-like to solid, with loss of reversibility and dysfunction in quality control. Thus, we suggest that the nucleolus has chaperone-like properties and can promote nuclear protein maintenance under stress.

Intercellular induction of apoptosis in transformed cells does not depend on p53.

Transformed fibroblast from p53 null/null mice were tested for their sensitivity to intercellular induction of apoptosis by TGF-beta-treated nontransformed cells. They were found to be as sensitive as p53-positive transformed cells. Based on morphological criteria, detection of chromatin condensation and DNA strand breaks, death of p53-negative transformed cells was due to apoptosis. p53-negative nontransformed cells were as efficient in the induction of apoptosis in transformed cells as p53-positive nontransformed cells. These data show that intercellular induction of apoptosis in transformed cells does not depend on functional p53. Therefore it may be assumed that mutations of p53 or modulation of its concentration are without relevance for this particular aspect of control of oncogenesis.

Automated reticulocyte counting and measurement of reticulocyte cellular indices. Evaluation of the Miles H*3 blood analyzer.

This study evaluated reticulocyte counting and measurement of reticulocyte cellular indices with the Miles H*3 blood analyzer, a new instrument that combines the Technicon/Miles technology for blood cells counting with a staining technique allowing counting of reticulocytes, quantification of staining intensity and measurement of reticulocyte cellular indices. Reticulocyte counts obtained with the Miles H*3 analyzer were compared with those obtained by manual counting, flow cytometry (thiazole orange method) and by the Sysmex R-3000 (Baxter Diagnostics) reticulocyte analyzer. Reticulocyte counting with the Miles H*3 showed excellent precision, and linearity in the range tested (1.1-49% and 1-72% reticulocytes, respectively, with two different protocols) with no significant carryover. Reticulocyte counts were stable after storing blood samples for 72 hours at 4 degrees C. Comparison of the four different methods, showed an acceptable intraclass correlation between Miles H*3 and Sysmex R-3000 (intraclass correlation coefficient, [ri] = .952), Miles H*3 and flow cytometry (ri = .922), and Sysmex R-3000 and flow cytometry (ri = .938). There was no satisfactory correlation between any of the three automated methods and the values obtained with manual counting of reticulocytes (ri = .538-.755), consistent with the well known imprecision of the manual technique. For a group of normal pediatric subjects, age 1-10, we obtained the following values (+/- SD) of reticulocyte indices: mean corpuscular volume 97.6 +/- 4.7 fL; cell hemoglobin concentration mean 28.2 +/- 1.4 g/dL; cell hemoglobin content 26.7 +/- 1.6 pg. We determined the direct cost, including depreciation, of the manual and instrumental methods. Cost/test varied from $1.61 for manual method to $6.03 for the Sysmex R-3000. Cost/test for flow cytometry and Miles H*3 were $3.34 and $3.49, respectively.

[KIPKEL--an interdisciplinary ambulatory prevention project for children with mentally ill parents]. / KIPKEL--ein interdisziplinäres ambulantes Präventionsprojekt für Kinder mit psychisch kranken Eltern.

Children of psychiatrically ill parents up to now have hardly been perceived as a risk group. In order to prevent these children form becoming psychiatrically ill the practice for art-therapy and psychotherapy and the social psychiatric service of the city of Hilden have developed a programme for parents having children under 18 years of age in which at least one parent suffers from endogenous psychosis or severe personality disorder. The two initiators of the KIPKEL project describe the experiences they had during the preparatory phase and while securing the financial basis and building up solid structures of cooperation. The conceptual basis of the project and problems of practical realization are presented. Finally an example of a family who participated in the programme is given. It illustrates the complex arrangement of interpersonal relationship and the course of the carework.

[Rates of prostate-specific antigen testing for early detection of prostate cancer: a first comparison of German results with current international data]. / PSA-basierte Früherkennung des Prostatakarzinoms durch den Hausarzt: Erste deutsche Ergebnisse im internationalen Vergleich.

OBJECTIVE: Measurement of prostate-specific antigen (PSA) is not only used as a screening instrument by urologists, but also by general practitioners and internal specialists (GP-IS). Until now, there are neither data on the approach of German GP-IS in practicing this nor have data been classified in the context of available international literature on this topic. MATERIALS AND METHODS: Between May and December 2012, a questionnaire containing 16 items was sent to 600 GP-IS in Brandenburg and Berlin. The response rate was 65% (392/600). Six indicator questions (IQ1-6) were selected and results were set in the context of available international data. The quality of present studies was evaluated by the Harden criteria. RESULTS: Of the 392 responding physicians, 317 (81%) declared that they would use PSA testing for early detection of PCA (IQ1) and, thus, formed the study group. Of these GP-IS, 38% consider an age between 41 and 50 years as suitable for testing begin (IQ2), while 53% and 14% of the GP-IS perform early detection until the age of 80 and 90 years, respectively (IQ3). A rigid PSA cut-off of 4 ng/ml is considered to be reasonable by 47% of the involved GP-IS, whereas 16% prefer an age-adjusted PSA cut-off (IQ4). Patients with pathological PSA levels were immediately referred to a board-certified urologist by 69% of the GP-IS. On the other hand, 10% first would independently control elevated PSA levels themselves after 3-12 months (IQ5). Furthermore, 14% of the interviewed physicians consider a decrease of PCA-specific mortality by PSA screening as being proven (IQ6). Knowledge regarding PCA diagnostics is mainly based on continuous medical education for GP-IS (33%), personal contact with urologists (6%), and guideline studies (4%). While 53% indicated more than one education source, 4% did not obtain any PCA-specific training. The results provided by this questionnaire evaluating response of German GP-IS to six selected indicator questions fit well into the international context; however, further studies with sufficient methodical quality are required. CONCLUSIONS: Despite current findings and controversial recommendations of the two large PCA screening studies on this issue, German GP-IS still frequently use PCA screening by PSA measurement. Primary strategies of early detection as well as follow-up after assessment of pathologically elevated PSA levels poorly follow international recommendations. Thus, an intensification of specific education is justified.

Fibroblasts transformed by chemical carcinogens are sensitive to intercellular induction of apoptosis: implications for the control of oncogenesis.

The ability of neighbouring normal cells to inhibit proliferation of transformed cells is regarded as the classical mode of intercellular control of potential tumour cells. This mechanism, however, only controls the pool size of transformed cells, but does not impair their survival. We have recently shown that cells transformed by biological agents are subject to a novel control system: transforming growth factor beta (TGF-beta) induces normal cells to release factors that mediate apoptosis specifically in transformed cells. Here we show that cells transformed by chemical carcinogens are also subject to this dominant control mechanism. The number of foci induced by methylcholanthrene, N-methyl-N'-nitro-N-nitrosoguanidine or quercetin was significantly reduced when the cultures were treated with TGF-beta. Established lines of chemically transformed cells proved to be sensitive to induction of apoptosis by neighbouring normal cells in the presence of TGF-beta. This finding demonstrates that sensitivity to induction of apoptosis is a general feature of transformed cells, irrespective of the transforming agent. It is particularly relevant for chemical carcinogenesis. As transformed cells were shown to trigger induction of their own apoptosis, the acquisition of resistance to this process may be a central regulatory step in carcinogenesis in vitro and possibly also in vivo. This study may help to elucidate mechanisms that protect transformed cells at an early stage of tumour progression that has until now not been the focus of investigation.