After wounding, a G-protein coupled receptor promotes the restoration of tension in epithelial cells.

The maintenance of epithelial barrier function involves cellular tension, with cells pulling on their neighbors to maintain epithelial integrity. Wounding interrupts cellular tension, which may serve as an early signal to initiate epithelial repair. To characterize how wounds alter cellular tension we used a laser-recoil assay to map cortical tension around wounds in the epithelial monolayer of the Drosophila pupal notum. Within a minute of wounding, there was widespread loss of cortical tension along both radial and tangential directions. This tension loss was similar to levels observed with Rok inactivation. Tension was subsequently restored around the wound, first in distal cells and then in proximal cells, reaching the wound margin ∼10 min after wounding. Restoring tension required the GPCR Mthl10 and the IP3 receptor, indicating the importance of this calcium signaling pathway known to be activated by cellular damage. Tension restoration correlated with an inward-moving contractile wave that has been previously reported; however, the contractile wave itself was not affected by Mthl10 knockdown. These results indicate that cells may transiently increase tension and contract in the absence of Mthl10 signaling, but that pathway is critical for fully resetting baseline epithelial tension after it is disrupted by wounding.

After wounding, a G-protein coupled receptor promotes the restoration of tension in epithelial cells.

The maintenance of epithelial barrier function involves cellular tension, with cells pulling on their neighbors to maintain epithelial integrity. Wounding interrupts cellular tension, which may serve as an early signal to initiate epithelial repair. To characterize how wounds alter cellular tension, we used a laser-recoil assay to map cortical tension around wounds in the epithelial monolayer of the Drosophila pupal notum. Within a minute of wounding, there was widespread loss of cortical tension along both radial and tangential directions. This tension loss was similar to levels observed with Rok inactivation. Tension was subsequently restored around the wound, first in distal cells and then in proximal cells, reaching the wound margin about 10 minutes after wounding. Restoring tension required the GPCR Mthl10 and the IP3 receptor, indicating the importance of this calcium signaling pathway known to be activated by cellular damage. Tension restoration correlated with an inward-moving contractile wave that has been previously reported; however, the contractile wave itself was not affected by Mthl10 knockdown. These results indicate that cells may transiently increase tension and contract in the absence of Mthl10 signaling, but that pathway is critical for fully resetting baseline epithelial tension after it is disrupted by wounding.

A simple sexing test for elephant species and its application to faecal DNA.

We developed a novel real-time PCR assay for rapid sexing in all three elephant species, which amplifies small fragments of the orthologous sexual chromosome zinc finger protein genes ZFX/ZFY (65 bp). This assay is a simple, inexpensive and reliable tool that is suitable for non-invasive DNA samples and can be incorporated into larger SNP panels for individual identification and population genetic studies.

Disruptive viability selection on a black plumage trait associated with dominance.

Traits used in communication, such as colour signals, are expected to have positive consequences for reproductive success, but their associations with survival are little understood. Previous studies have mainly investigated linear relationships between signals and survival, but both hump-shaped and U-shaped relationships can also be predicted, depending on the main costs involved in trait expression. Furthermore, few studies have taken the plasticity of signals into account in viability selection analyses. The relationship between signal expression and survival is of particular interest in melanin-based traits, because their main costs are still debated. Here, we first determined the main factors explaining variability in a melanin-based trait linked to dominance: the bib size of a colonial bird, the sociable weaver Philetairus socius. We then used these analyses to obtain a measure representative of the individual mean expression of bib size. Finally, we used capture-recapture models to study how survival varied in relation to bib size. Variation in bib size was strongly affected by year and moderately affected by age, body condition and colony size. In addition, individuals bearing small and large bibs had higher survival than those with intermediate bibs, and this U-shaped relationship between survival and bib size appeared to be more pronounced in some years than others. These results constitute a rare example of disruptive viability selection, and point towards the potential importance of social costs incurred by the dominance signalling function of badges of status.

Association between students' personality traits and hand hygiene compliance during objective standardized clinical examinations.

BACKGROUND: Although the need for hand hygiene (HH) is generally accepted, studies continue to document inadequate compliance. Medical students are taught about the importance of HH to prevent nosocomial infections, and receive training in the correct procedures for HH. However, personality traits (social orientation and achievement orientation) may influence HH compliance. People with high social orientation feel socially responsible and act cooperatively, and people with high achievement orientation are ambitious and competitive. AIM: To evaluate the relationship between HH compliance and personality traits of medical students. METHODS: The HH compliance of 155 students was observed during objective standardized clinical examinations (OSCEs). Social orientation and achievement orientation were measured using the corresponding scales of the Freiburg Personality Inventory - Revised. FINDINGS: Social orientation did not differ between students with high HH compliance and students with low HH compliance [F(1) = 3.87, P = 0.052, η(2) = 0.045]. For achievement orientation, a moderate effect was found between low and high HH compliance [F(1) = 11.242, P = 0.001, η(2) = 0.119], and students with high HH compliance were found to be more achievement orientated than students with low HH compliance. CONCLUSION: Achievement orientation plays a major role during OSCEs, while social orientation is less emphasized. To the authors' knowledge, this is the first study to show that HH compliance is associated with achievement orientation in achievement situations.

Non-invasive measurement of cardiac output during atrial fibrillation: comparison between cardiac magnetic resonance imaging and inert gas rebreathing.

OBJECTIVES: Atrial fibrillation (AF) is one of the most frequent heart rhythm disorders. It potentially influences cardiac function and its measurement. Cardiac magnetic resonance imaging (CMR) has become the new gold standard for non-invasive assessment of cardiac output (CO). A novel inert gas rebreathing (IGR) device based on the Fick Principle also proved promising in patients in sinus rhythm (SR). The aim of our study was to compare the agreement of non-invasive CO measurements between CMR and IGR in AF patients. METHODS: A total of 68 patients, 34 with AF and 34 pair-matched controls in SR, were included. RESULTS: Bland-Altman analysis showed good agreement between both methods, with an average deviation of 0.2 +/-1.2 l/min in the AF group versus 0.3 +/-1.0 l/min in the SR group (p = 0.77). IGR demonstrated good agreement for CO between 2.0 and 5.4 l/min. However, in hyperdynamic circulatory conditions (CO >5.5 l/min), the increasing disagreement of IGR and CMR measurements reached statistical significance. CONCLUSIONS: Non-invasive CO measurements using CMR and IGR are feasible in patients suffering from AF. Good agreement was found between the two methods in an unselected cohort. Hyperdynamic circulatory conditions can lead to significant measurement differences which, however, do not affect the reproducibility of IGR.

Inert gas rebreathing: the effect of haemoglobin based pulmonary shunt flow correction on the accuracy of cardiac output measurements in clinical practice.

BACKGROUND: Cardiac output (CO) is an important cardiac parameter, however its determination is difficult in clinical routine. Non-invasive inert gas rebreathing (IGR) measurements yielded promising results in recent studies. It directly measures pulmonary blood flow (PBF) which equals CO in absence of significant pulmonary shunt flow (Q(S)). A reliable shunt correction requiring the haemoglobin concentration (c(Hb)) as only value to be entered manually has been implemented. Therefore, the aim of the study was to evaluate the effect of various approaches to Q(S) correction on the accuracy of IGR. METHODS: Cardiac output determined by cardiac magnetic resonance imaging (CMR) served as reference values. The data was analysed in four groups: PBF without correcting for Q(S) (group A), shunt correction using the patients' individual c(Hb) values (group B), a fixed standard c(Hb) of 14.0 g dl(-1) (group C) and a gender-adapted standard c(Hb) for male (15.0 g dl(-1)) and female (13.5 g dl(-1)) probands each (group D). RESULTS: 147 patients were analysed. Mean CO(CMR) was 5.2 +/- 1.4 l min(-1), mean CO(IGR) was 4.8 +/- 1.3 l min(-1) in group A, 5.1 +/- 1.3 in group B, 5.1 +/- 1.3 l min(-1) in group C and 5.1 +/- 1.4 l min(-1) in group D. The accuracy in group A (mean bias 0.5 +/- 1.1 l min(-1)) was significantly lower as compared to groups B, C and D (0.1 +/- 1.1 l min(-1); P<0.01). CONCLUSION: IGR allows a reliable non-invasive determination of CO. Since PBF significantly increased the measurement bias, shunt correction should always be applied. A fixed c(Hb) of 14.0 g dl(-1) can be used for both genders if the exact c(Hb) value is not known. Nevertheless, the individual value should be used if any possible.

Aortic valve calcification: basic science to clinical practice.

Calcific aortic valve stenosis is the result of regulated cell processes. The histological hallmarks are inflammation and a remodelling of the extracellular matrix leading to bone formation. In the last 15 years the view has changed from it being an unmodifiable degenerative disease to an active biological process regulated by highly conserved ubiquitous cellular pathways. Many mechanisms and risk factors are the same as in atherosclerosis. Thus, statins and angiotensin II antagonists seemed promising treatment options. However, clinical trials failed to support this. This review describes the current understanding of major molecular mechanisms and discusses their role in clinical practice and possible therapy.

Incidence and clinical significance of left ventricular thrombus in tako-tsubo cardiomyopathy assessed with echocardiography.

BACKGROUND: Left ventricular (LV) thrombus is a known complication of tako-tsubo cardiomyopathy (TC). However, current literature almost exclusively consists of isolated case reports. The aim of this study was to determine the incidence and clinical significance of LV thrombus formation in TC. METHODS AND RESULTS: Over a 33-month period 52 patients with TC were assembled into a database at our institution. A retrospective database search was performed to identify patients with LV thrombus among these patients. LV thrombus, by echocardiography, was discovered in four patients[(8%); 95% confidence interval 3-19%]. Thrombus was present at the time of diagnosis in three patients. In one patient thrombus was absent initially and developed later. The LV apex was the site of thrombus formation in two patients, but the true apex was spared in the other two. All four patients had elevated serum levels of C-reactive protein (CRP). Two patients also had thrombocytosis. Treatment with low molecular weight heparin (LMWH) led to resolution of thrombus in all cases. CONCLUSION: Our findings suggest that LV thrombus is a noteworthy complication in TC. It can occur both at initial presentation or at anytime later during the disease course. Elevated CRP levels and thrombocytosis may indicate a higher risk of thrombus formation.

IL-6 determination in serum of kidney graft recipients by a new bedside test: its diagnostic relevance.

Interleukin-6 (IL-6) has diagnostic importance as one of the earliest indicators of inflammation, tissue damage, hypoxia, or infection. In contrast to the time-consuming immunoassays actually used in many laboratories, results of a new IL-6 bedside test, which is interpreted visually or photometrically, are available at 20 minutes. The photometric measurement using a stored standard curve allowed differentiation of five ranges: <50, 50-100, >100-200, >200-500, and >500-1000 pg/mL. The aim of our study was to evaluate the diagnostic relevance of this new IL-6 bedside test in four well-defined, noninfectious and infectious events after kidney transplantation. In a retrospective study the IL-6 serum levels were measured in a total of 269 serum samples from 27 renal graft recipients. Analysis of all data clearly showed that the majority of elevated IL-6 levels occurred in connection with bacterial infections. Viral infections did not result in an increase of IL-6 >50 pg/mL. Thus, from a clinical point of view this new bedside test can be recommended.

A hybrid approach for quantification of aortic valve stenosis using cardiac magnetic resonance imaging and echocardiography: comparison to right heart catheterization and standard echocardiography.

We replaced Doppler-derived stroke volume in the continuity equation (method A) by either right heart catheterization-derived stroke volume (method B) or cardiovascular magnetic resonance-derived stroke volume (method C) to calculate aortic valve area in 20 consecutive patients with moderate or severe aortic stenosis. Comparison of both hybrid methods (methods B and C) by Bland-Altman analysis showed a mean difference near zero, a spread within two standard deviations and very similar limits of agreement. More importantly, all patients were classified into the same category of severity by both methods.

Comparison of impedance cardiography and thermodilution-derived measurements of stroke volume and cardiac output at rest and during exercise testing.

BACKGROUND: Non-invasive evaluation of haemodynamic variables remains a preferable and attractive option in both pharmacologic research and clinical cardiology. OBJECTIVES: The objective of this study was to evaluate the correlation, feasibility and diagnostic value of haemodynamic measurements by ICG with the thermodilution (TD) method at rest and during exercise testing. METHODS: We measured stroke volume (SV) and cardiac output (CO) with both methods in 20 patients with suspected coronary artery disease (CAD). All measurements were performed simultaneously at rest and during bicycle exercise. RESULTS: There was a highly significant correlation (p < 0.001) for measurements of SV between both methods at rest (r = 0.83) and during exercise (r = 0.85-0.87) with 50-100 watts. For measurements of CO, the respective correlations were r = 0.85 at rest and r = 0.92-0.94 during exercise. The mean difference for measurements of SV were 3.8 +/- 12.6 ml at rest and 6.5+/- 11.4 ml during exercise. For measurements of CO, the mean difference between both methods was 0.9 +/- 1.0 l/min at rest and 1.0+/- 0.8 l/min during exercise. Compared to TD measurements, ICG had a bias to overestimate SV and CO of approximately by 5-10%. One patient had to be excluded because of inappropriate quality of the ICG signals during exercise. CONCLUSIONS: ICG is a feasible and accurate method for non-invasive measurements of SV and CO. Haemodynamic measurements by ICG were correlated highly significant to simultaneous measurements by the TD method.

Drotrecogin alfa (activated) inhibits NF-kappa B activation and MIP-1-alpha release from isolated mononuclear cells of patients with severe sepsis.

OBJECTIVE AND DESIGN: Non-anticoagulant biological activities, such as anti-inflammatory and anti-apoptotic mechanisms of action, have been suggested for recombinant human activated protein C (rhAPC; drotrecogin alfa (activated)). However, these mechanisms are much less characterized and understood than rhAPC's anticoagulant activity. Aim of the study was to determine the effect of rhAPC on the activity of the pro-inflammatory transcription factor nuclear factor kappa B (NF-kappaB) in mononuclear cells isolated from septic patients and to characterize an effect downstream from NF-kappaB activation, such as the release of the NF-kappaB-controlled chemokine Macrophage Inflammatory Protein-1-alpha (MIP-1-alpha). SUBJECTS: Peripheral blood was obtained from 13 septic patients and from 8 healthy controls. METHODS: Mononuclear cells were isolated by Ficoll-Paque density gradient centrifugation and were incubated with or without rhAPC (10 microg/ml) for 2 h for the measurement of NF-kappaB activity in cell lysates or alternatively for 6 h for the determination of MIP-1-alpha levels in supernatants. NF-kappaB activity was measured by an ELISA-based assay directed against the p50 and the p65 subunit of NF-kappaB. RESULTS: RhAPC, at supra-pharmacological concentration (10 microg/ml), significantly inhibited NF-kappaB activity and the release of MIP-1-alpha ex vivo in isolated mononuclear cells from patients with severe sepsis. In mononuclear cells of healthy subjects, however, rhAPC did not change NF-kappaB activity. Basal NF-kappaB activity early in severe sepsis was not predictive for survival. CONCLUSIONS: RhAPC at supra-pharmacological concentration (10 microg/ml) inhibits the activity of NF-kappaB in ex vivo isolated mononuclear cells of septic patients as well as the release of MIP-1-alpha, a proinflammatory chemokine regulated by NF-kappaB. These findings may represent immunomodulatory pathways by which rhAPC exerts specific anti-inflammatory activity in vitro in addition to its known anticoagulant and profibrinolytic activity and should be further investigated in an in vivo setting.

Expression and activity of matrix metalloproteinase-2 in calcific aortic stenosis.

Calcific aortic stenosis is the main heart valve disease in the elderly, leading to massive focal calcification and thickening of the valve cusps. Matrix metalloproteinases (MMPs) are thought to contribute to this process. Therefore, the study assessed the expression of the gelatinases MMP-2 and MMP-9 and the endogenous tissue inhibitor of metalloproteinase (TIMP)-2 as well as the gelatinolytic activity in normal and stenotic valves. Human tricuspid aortic valves with and without calcific aortic stenosis were studied by immunohistochemistry for MMP-2, MMP-9 and TIMP-2. The gelatinolytic activity in native valve sections was assessed by gelatin in situ zymography with or without addition of the MMP activator p-aminophenymercuric acetate (APMA). Staining intensities for MMP-2 and TIMP-2 were elevated in stenotic valves as compared to controls. Minor staining of MMP-9 was present exclusively in stenotic valves. The morphologic distribution of gelatinolytic activity was comparable to the staining pattern of MMP-2, and since MMP-9 immunostaining demonstrated only a low number of positive cells, the observed gelatinolytic activity is likely due to MMP-2. Gelatinolytic activity was low in normal valves but significantly increased by the MMP activator APMA. In contrast, stenotic valves showed a strong basal gelatinolytic activity that could not be significantly enhanced by APMA suggesting that MMP-2 is present as a latent pro-enzyme in normal valves and activated in stenotic valves. Thus, MMP-2 might be involved in the matrix remodeling during calcific aortic stenosis.

Lipopolysaccharide-binding protein as a new and reliable infection marker after kidney transplantation.

The early and reliable differentiation of rejections, viral infections and bacterial infections is one of the main problems after organ transplantation. One promising solution to this problem is the lipopolysaccharide-binding protein (LBP), which is regulated upwards in gram-negative sepsis and related conditions. Therefore, the aim of our study was to explore the diagnostic potential of LBP serum levels in well-defined, non-infectious and infectious events after kidney transplantation (KTx). In a retrospective study the LBP serum levels were measured in a total of 686 serum samples from 52 kidney graft recipients. In all pre-KTx sera tested, the mean LBP level was 8.8+/-3.5 microg/ml (reference range: 2.0-15.2 microg/ml). In 7 of 52 recipients without intraoperative T-cell depletion, the mean LBP level was significantly ( P<0.01) increased (13.0+/-1.5 microg/ml) at post-KTx day 1, but was within the reference range. In contrast, the intraoperative T-cell depletion by antilymphocyte antibodies resulted in a significant ( P<0.01) increase to 25.8+/-11.4 microg/ml (range: 13.3-47.2 microg/ml). In recipients with immediate ( n=14) or delayed ( n=9) graft function without any other complications, all post-KTx values (except the post-KTx peak) were within the reference range. In 10 recipients with steroid-sensitive rejections and in 11 recipients with steroid-resistant rejections, no rejection-associated changes of the LBP levels could be shown. In six recipients with cytomegalovirus infection, the detection of an antigenemia (pp65) also was not associated with alterations of the LBP levels. In addition, there was no correlation between LBP levels and the number of pp65-positive leukocytes in peripheral blood. In contrast, a strong elevation of LBP levels was seen in five recipients with gram-positive bacteremia as well as in other severe bacterial infections (e.g., purulent extravasate, heavily infected grafts, bacterial pneumonia and contaminated hematoma). In two recipients with superinfected (bacterial and mycotic or viral) Pneumocystis carinii pneumonias requiring assisted ventilation, LBP levels were elevated, too. Thus, in our study only systemic non-viral infections and massive lymphocytolysis were associated with elevated LBP serum levels.

Massive elevation of procalcitonin plasma levels in the absence of infection in kidney transplant patients treated with pan-T-cell antibodies.

OBJECTIVE: To determine the value of procalcitonin (PCT) monitoring in transplant patients receiving pan-T-cell antibody therapy. DESIGN: Retrospective clinical study. SETTING: A collaborative study between the Institute of Medical Immunology, the Department of Nephrology and Internal Intensive Care, both Charite, Humboldt University Berlin, and the Department of Laboratory Medicine, Friedrichshain Hospital, Berlin, Germany. PATIENTS AND INTERVENTIONS: Thirty-one patients were included in the study: 8 kidney transplant patients with acute rejection episodes, 5 receiving OKT3 monoclonal antibody therapy, 3 receiving steroid bolus therapy; 21 patients undergoing renal transplantation, 11 receiving ATG perioperatively, 10 without ATG administration; 2 patients undergoing renal transplantation and receiving anti-IL-2R mAb. MEASUREMENTS AND RESULTS: Procalcitonin (PCT) and tumor necrosis factor (TNF) alpha plasma levels were measured in infection-free transplant patients treated with the pan-T-cell antibodies ATG or OKT3. We found PCT plasma concentrations up to 600 ng/ml (reference < 0.5 ng/ ml), which are comparable to those seen in severe sepsis. Increases in TNF-alpha plasma levels preceded the rises in PCT. After peaking on day 1 of therapy the PCT plasma concentrations returned to normal values independently of further antibody administration. In contrast, steroid bolus therapy or anti-interleukin 2 receptor mAb administration did not increase plasma PCT or TNF-alpha levels. CONCLUSIONS: PCT monitoring for evaluating infectious complications in kidney transplant patients must be very careful during pan-T-cell antibody therapy.

Phylogenetic structure of the Sporopachydermia cereana species complex.

A large number of isolates previously referred to as members of the 'Sporopachydermia cereana species complex' were examined by various DNA characterization methods, leading to the conclusion that the complex is in fact made up of 10 species, one of which contains three varieties. The sequences of the internal transcribed spacer (ITS) region and the D1/D2 divergent domains of the large subunit rDNA were determined for representatives of each taxon and specific primers based on differences in the ITS were designed for rapid identification of five of the taxa. Whereas the data provide additional elements for the calibration of the ITS as a criterion for species delineation, the emerging pattern is that the ITS region does not function as well as the D1/D2 domains as an evolutionary clock. Some taxa appear to be specific for the geographical regions where they were isolated, and the distribution of many taxa is mutually exclusive.