PLoS One

Estimating and selecting risk factors with extremely low prevalences of exposure for a binary outcome is a challenge because classical standard techniques, markedly logistic regression, often fail to provide meaningful results in such settings. While penalized regression methods are widely used in high-dimensional settings, we were able to show their usefulness in low-dimensional settings as well. Specifically, we demonstrate that Firth correction, ridge, the lasso and boosting all improve the estimation for low-prevalence risk factors. While the methods themselves are well-established, comparison studies are needed to assess their potential benefits in this context. This is done here using the dataset of a large unmatched case-control study from France (2005-2008) about the relationship between prescription medicines and road traffic accidents and an accompanying simulation study. Results show that the estimation of risk factors with prevalences below 0.1% can be drastically improved by using Firth correction and boosting in particular, especially for ultra-low prevalences. When a moderate number of low prevalence exposures is available, we recommend the use of penalized techniques

Лексическое наполнение современных газет российских немцев как реализация этнической функции языка

The purpose of our study was to determine the expression of the pro-apoptotic BAX protein in relation to the mutational status of BAX and p53 (as transcriptional activator of the BAX gene) in benign and malignant thyroid tissue. In 47 patients with thyroid tumours (14 follicular and 3 papillary carcinomas, 14 adenomas and 16 goitres), the DNA was screened for mutations of BAX (exon 1-6) and p53 (exon 5-8) by single-strand conformation polymorphism polymerase chain reaction (SSCP-PCR). Furthermore, the protein expression of BAX, p53 and p21 (which is also increased transcriptionally by p53) was investigated by immunohistochemistry. Surprisingly, we observed elevated BAX levels in patients with thyroid carcinomas compared with patients with adenomas (unpaired t-test: p<0.05) or with goitres (p<0.02). This is in clear contrast to other carcinomas where BAX is frequently inactivated which correlates to a poor prognosis (Sturm et al., 1999). There were no significant differences of the BAX levels between goitres or the adenomas. In the SSCP-PCR analysis, no BAX mutations were detectable. P53 mutation analysis by SSCP-PCR did not reveal any functional p53 mutations in the patients with carcinomas, adenomas or goitres. Nevertheless, patients with carcinomas showed an overexpression (preferentially cytoplasmic) of p53 protein compared with patients with benign tumours (p<0.05). The absence of p53 mutations suggests that the overexpressed p53 is wild type. This is in line with the expression profile of BAX and p21, which showed a higher protein expression in these p53 positive tumours (p<0.05 in the carcinomas compared with the non-malignant lesions). Consequently, the overexpressed p53 might be a correlate for dysregulation without loss of function. This, in turn, might be a reason for the good outcome of some patients with thyroid cancer

Tumor stroma-derived TGF-beta limits Myc-driven lymphomagenesis via Suv39h1-dependent senescence

Activated RAS/BRAF oncogenes induce cellular senescence as a tumor-suppressive barrier in early cancer development, at least in part, via an oncogene-evoked DNA damage response (DDR). In contrast, Myc activation-although producing a DDR as well-is known to primarily elicit an apoptotic countermeasure. Using the Emu-myc transgenic mouse lymphoma model, we show here in vivo that apoptotic lymphoma cells activate macrophages to secrete transforming growth factor beta (TGF-beta) as a critical non-cell-autonomous inducer of cellular senescence. Accordingly, neutralization of TGF-beta action, like genetic inactivation of the senescence-related histone methyltransferase Suv39h1, significantly accelerates Myc-driven tumor development via cancellation of cellular senescence. These findings, recapitulated in human aggressive B cell lymphomas, demonstrate that tumor-prompted stroma-derived signals may limit tumorigenesis by feedback senescence induction

Информационная система сопровождения внутреннего аудита

Выпускная квалификационная работа посвящена анализу деятельности внутренних аудиторов, выявлению проблем автоматизации аудиторской деятельности; проектированию и разработке информационной системы внутреннего аудита, позволяющей автоматизировать деятельность внутренних аудиторов.The final qualifying work is devoted to the analysis of the activity of internal auditors, identification of problems of audit activity automation; designing and developing an information system for internal audit, which allows to automate the activities of internal auditors

A prospective study on the natural history of patients with profound combined immunodeficiency: An interim analysis

BACKGROUND: Absent T-cell immunity resulting in life-threatening infections provides a clear rationale for hematopoetic stem cell transplantation (HSCT) in patients with severe combined immunodeficiency (SCID). Combined immunodeficiencies (CIDs) and "atypical" SCID show reduced, not absent T-cell immunity. If associated with infections or autoimmunity, they represent profound combined immunodeficiency (P-CID), for which outcome data are insufficient for unambiguous early transplant decisions. // OBJECTIVES: We sought to compare natural histories of severity-matched patients with/without subsequent transplantation and to determine whether immunologic and/or clinical parameters may be predictive for outcome. // METHODS: In this prospective and retrospective observational study, we recruited nontransplanted patients with P-CID aged 1 to 16 years to compare natural histories of severity-matched patients with/without subsequent transplantation and to determine whether immunologic and/or clinical parameters may be predictive for outcome. // RESULTS: A total of 51 patients were recruited (median age, 9.6 years). Thirteen of 51 had a genetic diagnosis of "atypical" SCID and 14 of 51 of CID. About half of the patients had less than 10% naive T cells, reduced/absent T-cell proliferation, and at least 1 significant clinical event/year, demonstrating their profound immunodeficiency. Nineteen patients (37%) underwent transplantation within 1 year of enrolment, and 5 of 51 patients died. Analysis of the HSCT decisions revealed the anticipated heterogeneity, favoring an ongoing prospective matched-pair analysis of patients with similar disease severity with or without transplantation. Importantly, so far neither the genetic diagnosis nor basic measurements of T-cell immunity were good predictors of disease evolution. // CONCLUSIONS: The P-CID study for the first time characterizes a group of patients with nontypical SCID T-cell deficiencies from a therapeutic perspective. Because genetic and basic T-cell parameters provide limited guidance, prospective data from this study will be a helpful resource for guiding the difficult HSCT decisions in patients with P-CID

Reprogramming of B lymphoid cells in human lymphoma pathogenesis

Previous hypotheses have stated that differentiated cells lose the ability to change their fate. Using lymphoid development as a model system, recent data have challenged this rigid view of cellular differentiation. It has been shown in mouse models that, under certain conditions, even mature lymphoid cells can display a broad developmental potential, and might even transdifferentiate into other cell types. The relevance of these observations for the physiological ontogenesis of lymphoid cells or their malignant transformation is currently unclear. Recent data from our laboratory have demonstrated that similar processes can be observed in the malignant Hodgkin/Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (cHL), a common B cell-derived lymphoma. In HRS cells, the B cell-specific homodimer activity of the transcription factor E2A is functionally disrupted by overexpression of the E2A antagonists activated B cell factor 1 (ABF-1) and inhibitor of differentiation 2 (Id2). In consequence, the expression of B cell-specific genes is lost, and B lineage-inappropriate genes are upregulated. These data have demonstrated the plasticity of human lymphoid cells and offer an explanation for the unique phenotype of cHL. We first summarize data showing the plasticity of lymphoid cells in mouse models, second describe our observations regarding the altered B cell-specific transcription factor network in HRS cells, and third discuss the possible implications of these findings for human lymphoma pathogenesis

Die molekulare Pathogenese des klassischen Hodgkin-Lymphoms [The molecular pathogenesis of classical Hodgkin lymphoma]

Despite the fact that classical Hodgkin lymphoma (HL) has been described more than 170 years ago, only over the last 15 years significant advances regarding its molecular pathogenesis have been achieved. The lack of a specific lineage profile in combination with the low number of the malignant mononuclear Hodgkin- and multinucleated Reed-Sternberg- (HRS-) cells in the affected lymph nodes prevented for a long time both the identification of its cell of origin and of genomic and molecular defects. The development of methods for the analysis of micromanipulated single cells made it possible to demonstrate a B cell origin of HRS cells. However, it has become clear that the normal B cell-specific gene expression program in HRS cells is disrupted by various molecular lesions. Furthermore, molecular and genomic defects of various signaling pathways could be identified in HRS cells, including the NF-kappaB, JAK/STAT and MAPK-AP-1 signaling pathways, which protect HRS cells from apoptotic cell death. Despite significant advances in the treatment of HL, the considerable long term toxicity of conventional therapies requires the development of new non-genotoxic therapeutic strategies. Therefore, it will be a central aim to develop new treatment strategies based on these insights into HL pathogenesis