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Quantitative analysis of astrogliosis in drug-dependent humans.
ProstataCA

Abstract (Expand)

Drug addiction is a chronic, relapsing disease caused by neurochemical and molecular changes in the brain. In this human autopsy study qualitative and quantitative changes of glial fibrillary acidic … protein (GFAP)-positive astrocytes in the hippocampus of 26 lethally intoxicated drug addicts and 35 matched controls are described. The morphological characterization of these cells reflected alterations representative for astrogliosis. But, neither quantification of GFAP-positive cells nor the Western blot analysis indicated statistical significant differences between drug fatalities versus controls. However, by semi-quantitative scoring a significant shift towards higher numbers of activated astrocytes in the drug group was detected. To assess morphological changes quantitatively, graph-based representations of astrocyte morphology were obtained from single cell images captured by confocal laser scanning microscopy. Their underlying structures were used to quantify changes in astroglial fibers in an automated fashion. This morphometric analysis yielded significant differences between the investigated groups for four different measures of fiber characteristics (Euclidean distance, graph distance, number of graph elements, fiber skeleton distance), indicating that, e.g., astrocytes in drug addicts on average exhibit significant elongation of fiber structures as well as two-fold increase in GFAP-positive fibers as compared with those in controls. In conclusion, the present data show characteristic differences in morphology of hippocampal astrocytes in drug addicts versus controls and further supports the involvement of astrocytes in human pathophysiology of drug addiction. The automated quantification of astrocyte morphologies provides a novel, testable way to assess the fiber structures in a quantitative manner as opposed to standard, qualitative descriptions.

Authors: M. Weber, N. Scherf, T. Kahl, U. D. Braumann, P. Scheibe, J. P. Kuska, R. Bayer, A. Buttner, H. Franke

Date Published: 15th Mar 2013

Publication Type: Not specified

Human Diseases: heroin dependence

Enteral nutrition is associated with improved outcome in patients with severe sepsis. A secondary analysis of the VISEP trial.
SepNet - German Competence Network Sepsis

Abstract (Expand)

INTRODUCTION: The optimal nutritional strategy remains controversial, particularly in severely septic patients. Our aim was to analyze the effect of three nutritional strategies--enteral (EN), parenteral … (PN), and combined nutrition (EN+PN)--on the outcome of patients with severe sepsis or septic shock. PATIENTS AND METHODS: This secondary analysis of the prospective, randomized-controlled, multicenter "Intensive Insulin Therapy and Pentastarch Resuscitation in Severe Sepsis (VISEP)" trial only included patients with a length of stay in the intensive care unit (ICU) of more than 7 days. Besides patient characteristics, data on nutrition therapy were collected daily for up to 21 days. Morbidity as measured by the mean Sequential Organ Failure Assessment (SOFA) score, incidence of secondary infections, renal replacement therapy, ventilator-free days and severe hypoglycemia, length of ICU stay, and mortality at 90 days were compared between the three nutritional strategies. RESULTS: In all, 353 patients were included in the analysis with the majority (68.5 %) receiving EN+PN, 24.4 % receiving EN, and only 7.1 % receiving PN. Median caloric intake was 918 kcal/day (EN), 1,210 kcal/day (PN), and 1,343 kcal/day (EN+PN; p < 0.001). In the latter group, calories were predominantly administered via the parenteral route within the first week. The rate of death at 90 days was lower with EN than with EN+PN (26.7 % vs. 41.3 %, p = 0.048), as was the rate of secondary infections, renal replacement therapy, and duration of mechanical ventilation. In the adjusted Cox regression analysis, the effect on mortality [hazard ratio (HR)= 1.86, 95 % confidence interval (CI): 1.16-2.98, p = 0.010] and the rate of secondary infections (HR= 1.89, 95 % CI: 1.27-2.81, p = 0.002) remained different between EN and EN+PN. CONCLUSION: In patients with severe sepsis or septic shock and prolonged ICU stay, EN alone was associated with improved clinical outcome compared to EN+PN. This hypothesis-generating result has to be confirmed by a randomized-controlled trial in this specific patient population.

Authors: G. Elke, E. Kuhnt, M. Ragaller, D. Schadler, I. Frerichs, F. M. Brunkhorst, M. Loffler, K. Reinhart, N. Weiler

Date Published: 5th Mar 2013

Publication Type: Not specified

Human Diseases: disease by infectious agent

Assess, compare and enhance the status of Persons with Multiple Sclerosis (MS) in Europe: a European Register for MS.
LIFE - Leipzig Research Center for Civilization Diseases

Abstract (Expand)

OBJECTIVES: Persons with multiple sclerosis (PwMS) experience health-related quality of life (HRQoL) problems greatly differing across Europe, and the European Union (EU) faces deep inequalities in MS … management from country to country. Through the establishment of a European MS Register (EUReMS), an effective action is proposed to improve the overall knowledge on MS and support effective intervention programmes at EU and national political level. EUReMS aims to achieve consensus on its mission and vision, to define existing data providers, to develop models driving future MS health policies and research, to develop an information technology (IT) infrastructure for a data set, to develop a European shared governance and to secure providers' data provision into EUReMS. MATERIALS AND METHODS: EUReMS is meant to build on a minimum set of core data from existing national and regional population-based MS registries and from PwMS' perspectives. EUReMS' main partner is the European MS Platform (EMSP) acting in collaboration with associated and collaborating European partners. RESULTS: EUReMS was launched in July 2011. A Consensus Statement on purposes, vision, mission and strategies was produced in December 2011, and a comprehensive survey on existing MS data collections in Europe has been performed, and the EUReMS data mask is currently being discussed. CONCLUSIONS: EUReMS will represent a tool to provide up to date, comparable and sustainable MS data through an effective and credible register, which will encourage extensive knowledge building of MS, more equitable policies and higher standards in MS treatment and services.

Authors: M. Pugliatti, D. Eskic, T. Mikolcic, D. Pitschnau-Michel, K. M. Myhr, J. Sastre-Garriga, S. Otero, L. Wieczynska, C. Torje, E. Holloway, O. Rienhoff, T. Friede, K. Buckow, D. Ellenberger, J. Hillert, A. Glaser, P. Flachenecker, J. Fuge, T. Schyns-Liharska, E. Kasilingam, A. Moretti, C. Thalheim

Date Published: 3rd Jan 2013

Publication Type: Not specified

Human Diseases: dementia, Alzheimer's disease

A classification model for BRCA2 DNA binding domain missense variants based on homology-directed repair activity
GC-HBOC - German Consortium for Hereditary Breast and Ovarian Cancer

Abstract (Expand)

The relevance of many BRCA2 variants of uncertain significance (VUS) to breast cancer has not been determined due to limited genetic information from families carrying these alterations. Here, we … classified six new variants as pathogenic or nonpathogenic by analysis of genetic information from families carrying 64 individual BRCA2 DNA binding domain (DBD) missense mutations using a multifactorial likelihood model of cancer causality. Next, we evaluated the use of a homology-directed DNA break repair (HDR) functional assay as a method for inferring the clinical relevance of VUS in the DBD of BRCA2 using 18 established nonpathogenic missense variants and all 13 established pathogenic missense mutations from the BRCA2 DBD. Compared with the known status of these variants based on the multifactorial likelihood model, the sensitivity of the HDR assay for pathogenic mutations was estimated at 100% [95% confidence interval (CI): 75.3%-100%] and specificity was estimated at 100% (95% CI: 81.5%-100%). A statistical classifier for predicting the probability of pathogenicity of BRCA2 DBD variants was developed using these functional results. When applied to 33 additional VUS, the classifier identified eight with 99% or more probability of nonpathogenicity and 18 with 99% or more probability of pathogenicity. Thus, in the absence of genetic evidence, a cell-based HDR assay can provide a probability of pathogenicity for all VUS in the BRCA2 DBD, suggesting that the assay can be used in combination with other information to determine the cancer relevance of BRCA2 VUS.

Authors: Lucia Guidugli, Vernon S. Pankratz, Namit Singh, James Thompson, Catherine A. Erding, Christoph Engel, Rita Schmutzler, Susan Domchek, Katherine Nathanson, Paolo Radice, Christian Singer, Patricia N. Tonin, Noralane M. Lindor, David E. Goldgar, Fergus J. Couch

Date Published: 2nd Jan 2013

Publication Type: Journal article

Human Diseases: hereditary breast ovarian cancer syndrome

Ventilatory strategies in septic patients. Results from a nationwide observational trial
SepNet - German Competence Network Sepsis

Abstract (Expand)

BACKGROUND Mortality in intensive care unit (ICU) patients is affected by multiple variables. The possible impact of the mode of ventilation has not yet been clarified; therefore, a secondary analysis …s of the \textquotedblepidemiology of sepsis in Germany\textquotedbl study was performed. The aims were (1) to describe the ventilation strategies currently applied in clinical practice, (2) to analyze the association of the different modes of ventilation with mortality and (3) to investigate whether the ratio between arterial partial pressure of oxygen and inspired fraction of oxygen (PF ratio) and/or other respiratory variables are associated with mortality in septic patients needing ventilatory support. METHODS A total of 454 ICUs in 310 randomly selected hospitals participated in this national prospective observational 1-day point prevalence of sepsis study including 415 patients with severe sepsis or septic shock according to the American College of Chest Physicians/Society of Critical Care Medicine criteria. RESULTS Of the 415 patients, 331 required ventilatory support. Pressure controlled ventilation (PCV) was the most frequently used ventilatory mode (70.6 %) followed by assisted ventilation (AV 21.7 %) and volume controlled ventilation (VCV 7.7 %). Hospital mortality did not differ significantly among patients ventilated with PCV (57 %), VCV (71 %) or AV (51 %, p=0.23). A PF ratio equal or less than 300 mmHg was found in 83.2 % of invasively ventilated patients (n=316). In AV patients there was a clear trend to a higher PF ratio (204\pm70 mmHg) than in controlled ventilated patients (PCV 179\pm74 mmHg, VCV 175\pm75 mmHg, p=0.0551). Multiple regression analysis identified the tidal volume to pressure ratio (tidal volume divided by peak inspiratory airway pressure, odds ratio OR=0.94, 95 % confidence interval 95% CI=0.89-0.99), acute renal failure (OR=2.15, 95% CI=1.01-4.55) and acute physiology and chronic health evaluation (APACHE) II score (OR=1.09, 95% CI=1.03-1.15) but not the PF ratio (univariate analysis OR=0.998, 95 % CI=0.995-1.001) as independent risk factors for in-hospital mortality. CONCLUSIONS This representative survey revealed that severe sepsis or septic shock was frequently associated with acute lung injury. Different ventilatory modes did not affect mortality. The tidal volume to inspiratory pressure ratio but not the PF ratio was independently associated with mortality.

Authors: D. Schädler, G. Elke, C. Engel, H. Bogatsch, I. Frerichs, R. Kuhlen, R. Rossaint, M. Quintel, J. Scholz, F. M. Brunkhorst, M. Loeffler, K. Reinhart, N. Weiler

Date Published: 2013

Publication Type: Journal article

Human Diseases: disease by infectious agent

Comparing measures of association in 2x2 probability tables
Genetical Statistics and Systems Biology

Abstract

Not specified

Authors: Dirk Hasenclever, Markus Scholz

Date Published: 2013

Publication Type: Journal article

Merging concepts - coupling an agent-based model of hematopoietic stem cells with an ODE model of granulopoiesis
Genetical Statistics and Systems Biology

Abstract (Expand)

BACKGROUND\backslashr\backslashnHematopoiesis is a complex process involving different cell types and feedback mechanisms mediated by cytokines. This complexity stimulated various models with different … scopes and applications. A combination of complementary models promises to provide their mutual confirmation and to explain a broader range of scenarios. Here we propose a combination of an ordinary differential equation (ODE) model of human granulopoiesis and an agent-based model (ABM) of hematopoietic stem cell (HSC) organization. The first describes the dynamics of bone marrow cell stages and circulating cells under various perturbations such as G-CSF treatment or chemotherapy. In contrast to the ODE model describing cell numbers, our ABM focuses on the organization of individual cells in the stem population.\backslashr\backslashnRESULTS\backslashr\backslashnWe combined the two models by replacing the HSC compartment of the ODE model by a difference equation formulation of the ABM. In this hybrid model, regulatory mechanisms and parameters of the original models were kept unchanged except for a few specific improvements: (i) Effect of chemotherapy was restricted to proliferating HSC and (ii) HSC regulation in the ODE model was replaced by the intrinsic regulation of the ABM. Model simulations of bleeding, chronic irradiation and stem cell transplantation revealed that the dynamics of hybrid and ODE model differ markedly in scenarios with stem cell damage. Despite these differences in response to stem cell damage, both models explain clinical data of leukocyte dynamics under four chemotherapy regimens.\backslashr\backslashnCONCLUSIONS\backslashr\backslashnABM and ODE model proved to be compatible and were combined without altering the structure of both models. The new hybrid model introduces model improvements by considering the proliferative state of stem cells and enabling a cell cycle-dependent effect of chemotherapy. We demonstrated that it is able to explain and predict granulopoietic dynamics for a large variety of scenarios such as irradiation, bone marrow transplantation, chemotherapy and growth factor applications. Therefore, it promises to serve as a valuable tool for studies in a broader range of clinical applications, in particular where stem cell activation and proliferation are involved.

Authors: Axel Krinner, Ingo Roeder, Markus Loeffler, Markus Scholz

Date Published: 2013

Publication Type: Journal article

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