Effekt einer Antagonisierung der alpha- v-Integrine auf Angiogenese, Wachstum und Metastasierung solider Tumoren in vivo

Introduction: Antiangiogenetic cancer therapy is a potential new form for treatment of solid tumors. The alpha-v-integrins ( avb3, avb5) mediate the contact of activated endothelial cells to proteins of the extracellular matrix during tumor angiogenesis as a prerequisite for survival of endothelial cells. The aim of this study was to investigate the effects of inhibition of alpha-v-integrins with a methylated cyclic RGD-peptide on angiogenesis, microcirculation, growth and metastasis formation of a solid tumor in vivo. Methods: Experiments were performed in the dorsal skinfold preparation of Syrian Golden hamsters bearing the amelanotic hamster melanoma A-Mel-3. Animals were injected intraperitoneally with a methylated cyclic RGD-peptide every 12 hours, the control group received an inactive peptide. Microcirculatory parameters of tumor angiogenesis including functional vessel density, red blood cell velocity (vRBC), vessel diameter and leukocyte endothelium interaction were analyzed using intravital microscopy. In an additional study the effects on growth and metastasis of subcutaneous A-Mel-3 were quantified. Results: Functional vessel density was markedly reduced on day 3 in treated animals compared to controls (37.2+/-12.1 vs. 105.2+/-11.2 cm-1; mean+/-SEM; P < 0.05), and increased subsequently in both groups. vRBC at day 3 was below values of controls (0.026+/-0.01 vs. 0.12+/-0.03 mm/s; P < 0.05). No differences were observed in vessel diameters and leukocyte-endothelium interaction was almost absent in both groups. Furthermore, growth and metastasis of subcutaneous tumors after administration of the cyclic RGD-peptide was significantly delayed in comparison to controls (P < 0.05). Conclusion: Inhibition of alpha-v-integrins by a cyclic RGD-peptide resulted in significant delay of early tumor angiogenesis, associated with retardation of tumor growth and metastasis in vivo. Application of cyclic RGD-peptides may thus be a promising approach for antiangiogenic therapy of solid tumor

Dynamics of disease characteristics and clinical management of critically ill COVID-19 patients over the time course of the pandemic: an analysis of the prospective, international, multicentre RISC-19-ICU registry.

BACKGROUND It remains elusive how the characteristics, the course of disease, the clinical management and the outcomes of critically ill COVID-19 patients admitted to intensive care units (ICU) worldwide have changed over the course of the pandemic. METHODS Prospective, observational registry constituted by 90 ICUs across 22 countries worldwide including patients with a laboratory-confirmed, critical presentation of COVID-19 requiring advanced organ support. Hierarchical, generalized linear mixed-effect models accounting for hospital and country variability were employed to analyse the continuous evolution of the studied variables over the pandemic. RESULTS Four thousand forty-one patients were included from March 2020 to September 2021. Over this period, the age of the admitted patients (62 [95% CI 60-63] years vs 64 [62-66] years, p < 0.001) and the severity of organ dysfunction at ICU admission decreased (Sequential Organ Failure Assessment 8.2 [7.6-9.0] vs 5.8 [5.3-6.4], p < 0.001) and increased, while more female patients (26 [23-29]% vs 41 [35-48]%, p < 0.001) were admitted. The time span between symptom onset and hospitalization as well as ICU admission became longer later in the pandemic (6.7 [6.2-7.2| days vs 9.7 [8.9-10.5] days, p < 0.001). The PaO2/FiO2 at admission was lower (132 [123-141] mmHg vs 101 [91-113] mmHg, p < 0.001) but showed faster improvements over the initial 5 days of ICU stay in late 2021 compared to early 2020 (34 [20-48] mmHg vs 70 [41-100] mmHg, p = 0.05). The number of patients treated with steroids and tocilizumab increased, while the use of therapeutic anticoagulation presented an inverse U-shaped behaviour over the course of the pandemic. The proportion of patients treated with high-flow oxygen (5 [4-7]% vs 20 [14-29], p < 0.001) and non-invasive mechanical ventilation (14 [11-18]% vs 24 [17-33]%, p < 0.001) throughout the pandemic increased concomitant to a decrease in invasive mechanical ventilation (82 [76-86]% vs 74 [64-82]%, p < 0.001). The ICU mortality (23 [19-26]% vs 17 [12-25]%, p < 0.001) and length of stay (14 [13-16] days vs 11 [10-13] days, p < 0.001) decreased over 19 months of the pandemic. CONCLUSION Characteristics and disease course of critically ill COVID-19 patients have continuously evolved, concomitant to the clinical management, throughout the pandemic leading to a younger, less severely ill ICU population with distinctly different clinical, pulmonary and inflammatory presentations than at the onset of the pandemic

Dietary advice for muscularity, leanness and weight control in Men's Health magazine: a content analysis

Background: The dietary content of advice in men’s lifestyle magazines has not been closely scrutinised. Methods: We carried out an analysis of such content in all 2009 issues (n = 11) of Men’s Health (MH) focusing on muscularity, leanness and weight control. Results: Promotion of a mesomorphic body image underpinned advice to affect muscle building and control weight. Diet advice was underpinned by a strong pseudo-scientific discourse, with citation of expert sources widely used to legitimise the information. Frequently multiple dietary components were advocated within one article e.g. fat, omega-3 fatty acids, thiamine, zinc and high-glycaemic index foods. Furthermore advice would cover numerous nutritional effects, e.g. strengthening bones, reducing stress and boosting testosterone, with little contextualisation. The emphasis on attainment of a mesomorphic body image permitted promotion of slimming diets. Advice to increase calorie and protein intake to augment muscle mass was frequent (183 and 262 references, respectively). Such an anabolic diet was advised in various ways, including consumption of traditional protein foods (217 references) and sports foods (107 references), thereby replicating muscle magazines’ support for nutritional supplements. Although advice to increase consumption of red meat was common (52 references), fish and non-flesh sources of protein (eggs, nuts & pulses, and soy products) together exceeded red meat in number of recommendations (206 references). Advice widely asserted micronutrients and phytochemicals from plant food (161 references) as being important in muscle building. This emphasis diverges from stereotypical gender-based food consumption patterns. Dietary advice for control of body weight largely replicated that of muscularity, with strong endorsement to consume fruits and vegetables (59 references), diets rich in nuts and pulses and fish (66 references), as well as specific micronutrients and phytochemicals (62 references). Notably there was emphasis on fat-burning, good fats and consumption of single foods, with relatively little mention of dietary restriction. Conclusions: Despite the widespread use of scientific information to endorse dietary advice, the content, format and scientific basis of dietary content of MH leaves much to be desired. The dietary advice as provided may not be conducive to public health

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Microdeletions within the hydrophobic core region of cellular prion protein alter its topology and metabolism

Lutz J, Brabeck C, Niemann H, et al. Microdeletions within the hydrophobic core region of cellular prion protein alter its topology and metabolism. BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS. 2010;393(3):439-444.The cellular prion protein (PrPC) is a GPI-anchored cell-surface protein. A small subset of PrPC molecules, however, can be integrated into the ER-membrane via a transmembrane domain (TM), which also harbors the most highly conserved regions of PrPC, termed the hydrophobic core (HC). A mutation in HC is associated with prion disease resulting in an enhanced formation of a transmembrane form ((PrP)-Pr-ctm), which has thus been postulated to be a neurotoxic molecule besides PrPSc. To elucidate a possible physiological function of the transmembrane domain, we created a set of mutants carrying microdeletions of 2-8 aminoacids within HC between position 114 and 121. Here, we show that these mutations display reduced propensity for transmembrane topology. In addition, the mutants exhibited alterations in the formation of the Cl proteolytic fragment, which is generated by a-cleavage during normal PrPC metabolism, indicating that HC might function as recognition site for the protease(s) responsible for PrPC alpha-cleavage. Interestingly, the mutant G113V, corresponding to a hereditary form of prion disease in humans, displayed increased (PrP)-Pr-Ctm topology and decreased alpha-cleavage in our in vitro assay. In conclusion, HC represents an essential determinant for transmembrane PrP topology, whereas the high evolutionary conservation of this region is rather based upon preservation of PrPC alpha-cleavage, thus highlighting the biological importance of this cleavage. (C) 2010 Elsevier Inc. All rights reserved

Alterations of the serum N-glycan profile in female patients with Major Depressive Disorder

Background: Glycans are short chains of saccharides linked to glycoproteins that are known to be involved in a wide range of inflammatory processes. As depression has been consistently associated with chronic low-grade inflammation, we asked whether patients with Major Depressive Disorder show alterations in the N-glycosylation pattern of serum proteins that might be linked to associated changes in inflammatory processes. Methods: In a study cohort of 21 female patients with an acute depressive episode and 21 non-depressed female control subjects aged between 50 and 69 years, we analyzed the serum N-glycan profile by DNA Sequencer Adapted-Fluorophore Assisted Carbohydrate Electrophoresis (DSA-FACE) and assessed the serum levels of interleukin (IL)-6, tumor necrosis factor (TNF)-alpha and C-reactive protein (CRP) by chemiluminescence immunoassays and nephelometry. Results: Compared to controls, MDD patients showed significant differences in the serum levels of several N-glycan structures. Alterations in the serum N-glycan profile were associated with depressive symptom severity and exploratory analyses revealed that they were most pronounced in MDD patients with a history of childhood sexual abuse. Furthermore, MDD patients showed higher levels of IL-6 and a trend for higher CRP levels, which were also associated with similar alterations in the serum N-glycan profile as those characteristic for MDD patients. Limitations: The relatively small sample size and the presence of potential confounders (e.g., BMI, smoking, medication). Conclusion: The results offer the first evidence that specific differences in the N-glycosylation pattern of serum proteins constitute a so far unrecognized level of biological alterations that might be involved in the immune changes associated with MDD

The Role of Norepinephrine and [alpha] -Adrenergic Receptors in Acute Stress-Induced Changes in Granulocytes and Monocytes

Objective Acute stress induces redistribution of circulating leucocytes in humans. Although effects on lymphocytes as adaptive immune cells are well understood, the mechanisms underlying stress effects on granulocytes and monocytes as innate immune blood cells are still elusive. We investigated whether the stress hormone norepinephrine (NE) and -adrenergic receptors (-ADRs) may play a mediating role.Methods In a stress study, we cross-sectionally tested 44 healthy men for associations between stress-induced NE increases and simultaneous granulocyte and monocyte cell count increases, as measured immediately before and several times after the Trier Social Stress Test. In a subsequent infusion study, 21 healthy men participated in three different experimental trials with sequential infusions of 1- and 15-minute duration with varying substances (saline as placebo, the nonspecific -ADR blocker phentolamine [2.5 mg/min], and NE [5 g/min]): trial 1 = saline+saline, trial 2 = saline+NE, trial 3 = phentolamine+NE. Granulocyte and monocyte cell numbers were assessed before, immediately after, 10 minutes, and 30 minutes after infusion procedures.Results In the stress study, higher NE related to higher neutrophil stress changes ( = .31, p = .045, R-2 change = .09), but not epinephrine stress changes. In the infusion study, saline+NE induced significant increases in neutrophil (F(3/60) = 43.50, p &lt; .001, (2) = .69) and monocyte (F(3/60) = 18.56, p &lt; .001, (2) = .48) numbers compared with saline+saline. With phentolamine+NE, neutrophil (F(3/60) = 14.41, p &lt; .001, (2) = .42) and monocyte counts (F(2.23/44.6) = 4.32, p = .016, (2) = .18) remained increased compared with saline+saline but were lower compared with saline+NE (neutrophils: F(3/60) = 19.55, p &lt; .001, (2) = .494, monocytes: F(3/60) = 2.54, p = .065, (2) = .11) indicating partial mediation by -ADRs. Trials did not differ in eosinophil and basophil count reactivity.Conclusions Our findings suggest that NE-induced immediate increases in neutrophil and monocyte numbers resemble psychosocial stress effects and can be reduced by blockade of -ADRs

Structure and Gelation Mechanism of Tunable Guanosine-Based Supramolecular Hydrogels

The mechanism of gelation of 50/50 w/w mixtures of guanosine (G) and 2′,3′,5′-tri-O-acetylguanosine (TAcG) in aqueous 0.354 M KCl was investigated using a combination of static light scattering (SLS), polarized and depolarized dynamic light scattering (VV and VH DLS), small-angle neutron and X-ray scattering (SANS and SAXS), and viscometric experiments. SLS and viscometry show a dramatic increase in apparent molecular weight and hydrodynamic volume at 0.2 wt % and 0.3 wt %, respectively, indicating the critical concentration for self-association of G/TAcG quartets into columnar assemblies lies below 0.2 wt %. Above this concentration, SANS and SAXS generate complementary information on the structure of the individual columnar stacks. VV and VH DLS results indicate bimodal correlation functions, whose properties suggest, respectively, translational and rotational diffusion of a bimodal distribution of particles. The fast mode appears to originate from fibrillar agglomerates of G/TAcG columnar quartet assemblies, while the slow mode comes from microgel domains. Guinier plot analysis of the SLS data probes the internal structure of the microgel domains. Collectively, the results suggest that sol and microgel phases coexist below the macroscopic gel point, and that the sol phase contains individual columnar stacks of G/TAcG quartets and fibrillar aggregates formed via lateral aggregation of these columnar assemblies. With increasing concentration, the DLS data indicate a progressive increase in the volume fraction of microgel domains, which ultimately leads to macroscopic gelation. Prior observation of a transient network contribution to the gel rheology at low temperature is attributed to the presence of individual columnar stacks within the gel network