Effect of Single High Dose Vitamin D Substitution in Hospitalized COVID-19 Patients with Vitamin D Deficiency on Length of Hospital Stay

Vitamin D and its role in the coronavirus-19 disease (COVID-19) pandemic has been controversially discussed, with inconclusive evidence about vitamin D3 (cholecalciferol) supplementation in COVID-19 patients. Vitamin D metabolites play an important role in the initiation of the immune response and can be an easily modifiable risk factor in 25-hydroxyvitamin D₃ (25(OH)D₃)-deficient patients. This is a multicenter, randomized, placebo-controlled double-blind trial to compare the effect of a single high dose of vitamin D₃ followed by treatment as usual (TAU) of daily vitamin D₃ daily until discharge versus placebo plus TAU in hospitalized patients with COVID-19 and 25(OH)D₃-deficiency on length hospital stay. We included 40 patients per group and did not observe a significant difference in the median length of hospital stay (6 days in both groups, p = 0.920). We adjusted the length of stay for COVID-19 risk factors (β = 0.44; 95% CI: -2.17-2.22), and center (β = 0.74; 95% CI: -1.25-2.73). The subgroup analysis in patients with severe 25(OH)D₃-deficiency (<25 nmol/L) showed a non-significant reduction in the median length of hospital stay in the intervention group (5.5 vs. 9 days, p = 0.299). The competing risk model with death did not reveal significant differences between the group in the length of stay (HR = 0.96, 95% CI 0.62-1.48, p = 0.850). Serum 25(OH)D₃ level increased significantly in the intervention group (mean change in nmol/L; intervention: +26.35 vs. control: -2.73, p < 0.001). The intervention with 140,000 IU vitamin D₃ + TAU did not significantly shorten the length of hospital stay but was effective and safe for the elevation of serum 25(OH)D₃ levels.

Inhaled aviptadil for the possible treatment of COVID-19 in patients at high risk for ARDS: study protocol for a randomized, placebo-controlled, and multicenter trial

Background

Despite the fast establishment of new therapeutic agents in the management of COVID-19 and large-scale vaccination campaigns since the beginning of the SARS-CoV-2 pandemic in early 2020, severe disease courses still represent a threat, especially to patients with risk factors. This indicates the need for alternative strategies to prevent respiratory complications like acute respiratory distress syndrome (ARDS) associated with COVID-19. Aviptadil, a synthetic form of human vasoactive intestinal peptide, might be beneficial for COVID-19 patients at high risk of developing ARDS because of its ability to influence the regulation of exaggerated pro-inflammatory proteins and orchestrate the lung homeostasis. Aviptadil has recently been shown to considerably improve the prognosis of ARDS in COVID-19 when applied intravenously. An inhaled application of aviptadil has the advantages of achieving a higher concentration in the lung tissue, fast onset of activity, avoiding the hepatic first-pass metabolism, and the reduction of adverse effects. The overall objective of this project is to assess the efficacy and safety of inhaled aviptadil in patients hospitalized for COVID-19 at high risk of developing ARDS.

Methods

This multicenter, placebo-controlled, double-blinded, randomized trial with 132 adult patients hospitalized for COVID-19 and at high risk for ARDS (adapted early acute lung injury score ≥ 2 points) is conducted in five public hospitals in Europe. Key exclusion criteria are mechanical ventilation at baseline, need for intensive care at baseline, and severe hemodynamic instability. Patients are randomly allocated to either inhale 67 μg aviptadil or normal saline (three times a day for 10 days), in addition to standard care, stratified by center. The primary endpoint is time from hospitalization to clinical improvement, defined as either hospital discharge, or improvement of at least two levels on the nine-level scale for clinical status suggested by the World Health Organization.

Discussion

Treatment strategies for COVID-19 are still limited. In the context of upcoming new variants of SARS-CoV-2 and possible inefficacy of the available vaccines and antibody therapies, the investigation of alternative therapy options plays a crucial role in decreasing associated mortality and improving prognosis. Due to its unique immunomodulating properties also targeting the SARS-CoV-2 pathways, inhaled aviptadil may have the potential to prevent ARDS in COVID-19.

Trial registration

ClinicalTrials.gov, NCT04536350. Registered 02 September 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06723-w.

High-dose vitamin D substitution in patients with COVID-19: study protocol for a randomized, double-blind, placebo-controlled, multi-center study-VitCov Trial

Background

The coronavirus disease 19 (COVID-19) pandemic has caused millions of deaths, and new treatments are urgently needed. Factors associated with a worse COVID-19 prognosis include old age (> 65 years), ethnicity, male sex, obesity, and people with comorbidities. Furthermore, vitamin D deficiency was reported as a predictor of poor prognosis in patients with acute respiratory failure due to COVID-19. According to a recent clinical case series, vitamin D deficiency is a modifiable risk factor, which has the prospect of reducing hospital stay, intensive care, and fatal outcomes. Vitamin D has potent immunomodulatory properties, and its supplementation might improve important outcomes in critically ill and vitamin D-deficient COVID-19 patients. Despite the evidence that supports an association between vitamin D deficiency and COVID-19 severity, there is uncertainty about the direct link. Therefore, the aim of the trial is to assess if high-dose vitamin D supplementation has a therapeutic effect in vitamin D-deficient patients with COVID-19.

Methods

As the trial design, a randomized, placebo-controlled, double-blind, multi-center approach was chosen to compare a high single dose of vitamin D (140,000 IU) followed by treatment as usual (TAU) (VitD + TAU) with treatment as usual only (placebo + TAU) in patients with COVID-19 and vitamin D deficiency.

Discussion

Vitamin D substitution in patients with COVID-19 and vitamin D deficiency should be investigated for efficacy and safety. The study aim is to test the hypothesis that patients with vitamin D deficiency suffering from COVID-19 treated under standardized conditions in hospital will recover faster when additionally treated with high-dose vitamin D supplementation. Latest studies suggest that vitamin D supplementation in patients with COVID-19 is highly recommended to positively influence the course of the disease. With this randomized controlled trial, a contribution to new treatment guidelines shall be made.

Trial registration

ClinicalTrials.gov NCT04525820 and SNCTP 2020-01401

Point of care with serial NT-proBNP measurement in patients with acute decompensated heart failure as a therapy-monitoring during hospitalization (POC-HF): Study protocol of a prospective, unblinded, randomized, controlled pilot trial

Despite important advances in diagnosis and medical therapy of heart failure (HF), disease monitoring and therapy guidance remains to be based on clinical signs and symptoms. NT-proBNP was repeatedly demonstrated to be a strong and independent predictor of morbidity and mortality in patients with HF. Only few – and conflicting – data are available on the efficacy of serial measurement of NT-proBNP as a tool for treatment monitoring in HF. These data are limited to the outpatient setting. Currently, no data are available on the effects of this approach in patients hospitalized for acute decompensated HF. The goal of this study is to explore whether the availability of serial NT-proBNP measurements may influence treatment decisions in patients with acute decompensated HF, and whether this leads to more rapid dose adjustments of prognostically beneficial medical therapies and earlier hospital discharge. In the intervention group, serial measurements of NT-proBNP every second business day are performed and made available to the treating physician, while no serial measurements are available in control group. HF therapy is left at the discretion of the treating physician. The primary endpoints are defined as the effects of monitoring NT-proBNP on medical HF therapy decisions, including type and dosing of medical therapies and the rapidity of adjustments, length of hospital stay, and evaluation of the changes in NT-proBNP values. Additional secondary endpoints include incidence of electrolyte imbalances and renal failure, changes in NYHA functional class, vital signs, body weight, quality of life, incidence of adverse events, transfer to Intensive Care Units, and mortality.

FRI0456 EARLY IMPLEMENTATION OF TREATMENT WITH ETANERCEPT INCREASES THE LIKELIHOOD TO ACHIEVE REMISSION

Background:

Juvenile idiopathic arthritis (JIA) is the most common chronic inflammatory rheumatic disease in children and adolescents. A consistent therapy is required to avoid consequential damage and permanent loss of function. Biologic disease modifying anti-rheumatic drugs (bDMARDs) provide a well-accepted option for treatment of patients with a severe course of JIA. Etanercept (ETA) is still the most commonly prescribed bDMARD for JIA in Germany.

Objectives:

To analyze adherence to treatment with ETA with special attention on discontinuation after achieving an inactive disease and recurrence of active disease after ETA withdrawal.

Methods:

Data from two ongoing prospective, multicenter, non-interventional registries BiKeR and JuMBO were used for the analysis. JuMBO is the follow-up study to BiKeR and follows patients who have reached the age of 18. Both registers provide treatment data, individual trajectories of clinical data and outcomes from childhood into adulthood in JIA patients treated with bDMARDs and csDMARDs. Clinical disease characteristics, such as disease activity, were reported by the rheumatologists in addition to patient-reported outcomes at each six-months follow-up. Remission was defined as inactive disease defined by the Wallace Criteria (1).

Results:

Data from 2,500 patients who were included in BiKeR and had an age ≥18 at the time of analysis were considered. A subset of 1,535 were enrolled in JuMBO. The mean follow-up was 8.6 (SD 4.2) years for the JuMBO patients. The majority of them had polyarthritis (35%), followed by enthesitis-related arthritis (20%). A total of 1,779 (68.8% of 2,584) patients were ever treated with ETA, providing 2,178 ETA treatment courses. There were 1,724 (67%) patients with first, 338 patients with a second and 54 with a third course of ETA treatment course. 710 (41.2%) discontinued ETA by ineffectiveness in the first course with similar rates of discontinuation due to ineffectiveness in the first and second course. A total of 332 (+/-MTX, 19.3%) discontinued ETA after achieving remission in the first ETA course. Among those, 129 (38.9%) patients did not require treatment with any other bDMARD subsequently until last follow-up (3.9 years, SD 3.5), while 169 (50.9%) re-started treatment with ETA, 14 (4.2%) with adalimumab and 4 with other bDMARDs. The likelihood of discontinuing ETA due to an inactive disease was positively associated with a younger age (hazard ratio (HR) 1.08, p<0.001), persistent oligoarthritis (HR 1.89, p=0.004), a shorter duration between JIA onset and ETA start (HR 1.10, p<0.001) as well as a good response to therapy within the first six months of treatment (HR 1.11, p<0.001). 209 (of 332) had ETA monotherapy at withdrawal. Of those, 77% (n=161) experienced recurrence of disease with a mean time to flare of 12.1 (SD 13.7) months. 129 patients restarted bDMARD therapy (n=117 ETA). We could not identify any correlates for the risk of flare. 70% re-achieved remission and 20% again discontinued therapy thereafter.

Conclusion:

The study confirms the good effectiveness of ETA, even in the re-treatment of patients with JIA. Our data highlight the association of an early bDMARD treatment with a higher likelihood to achieve an inactive disease indicating a window of opportunity.

References:

[1]Wallace CA, Giannini EH, Huang B et al. American College of Rheumatology provisional criteria for defining clinical inactive disease in select categories of juvenile idiopathic arthritis. Arthritis Care Res 2011;63:929–36

Disclosure of Interests:

Jens Klotsche: None declared, Gerd Horneff Grant/research support from: AbbVie, Chugai, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Speakers bureau: AbbVie, Bayer, Chugai, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Peter Haas: None declared, Ivan Foeldvari Consultant of: Novartis, Martina Niewerth: None declared, Kirsten Minden Consultant of: GlaxoSmithKline, Sanofi, Speakers bureau: Roche

THU0500 PHYSICAL ACTIVITY AND SCREEN-BASED MEDIA USE IN ADOLESCENTS WITH JUVENILE IDIOPATHIC ARTHRITIS - DATA FROM A GERMAN INCEPTION COHORT

Background:

Insufficient physical activity (PA) and screen-based media use (SBM) are different aspects of sedentary behavior (SB), independently and inversely related to health and wellbeing. Recent research indicates that adolescents with chronic conditions are at least as likely at risk of being physically inactive or accumulating high levels of screen-based SB when compared with their healthy peers [1].

Objectives:

Since PA and SBM have not yet been (sufficiently) evaluated in young patients with juvenile idiopathic arthritis (JIA), our aim was to i) quantify the daily SBM use of adolescents with JIA, ii) measure the frequency of their weekly PA, and iii) compare both aspects of SB with those of age- and sex-matched controls from the general population during the course of the disease.

Methods:

Data from JIA patients and controls enrolled in the inception cohort study ICON were analyzed. Young people, such as friends and mates, served as the peer group. Patients and peers aged 13 and over were followed prospectively and questioned about their weekly PA frequency and SBM use at a two-year interval. Data from young people for whom at least two questionnaires were available were analyzed using linear mixed models.

Results:

Data from 209 patients with JIA (63% female, 28% rheumatoid factor negative polyarthritis) and 138 peers (55% female) were included in the analysis. At baseline (T1), 51% of the patients were treated with a DMARD, 58% at follow-up (T2). The proportion of adolescents being physically active at most twice a week was substantially higher in patients than in controls (T1: 59% vs. 43%; T2: 54% vs. 42%). In patients, the total daily screen time was 3.5±2.6 hours at T1 and 3.6±2.5h at T2, respectively. In comparison, a value about 0.5h less was found in the controls both at T1 and T2. Both groups increasingly spent time on mobile phones during the observation period. At T1 (66% vs. 45%) and T2 (60% vs. 45%), the proportion of physically inactive girls was significantly higher than that of boys. Conversely, boys reported higher levels of SBM than girls. Patients with high SBM consumption (>3h/day) showed a significantly lower PedsQLTM psychosocial functioning (OR 0.94; 95%CI: 0.89-0.99) and a significantly higher cJADAS-10 score (OR 1.34; 95%CI: 1.07-1.67) than those who did not exceed the national recommendations on SBM use.

Sedentary behaviorsBaseline2-year follow-upJIAN=209 (%)CGN=138 (%)JIAN=209 (%)CGN=138 (%)TV/videosAt most 2h/day85.489.086.293.4At least 3h/day14.611.013.76.6Computer/InternetAt most 2h/day76.983.172.174.6At least 3h/day23.016.927.825.4Gaming consolesAt most 2h/day93.598.592.596.2At least 3h/day6.51.57.53.8Total screen timeAt most 2h/day40.045.141.539.5At least 5h/day26.215.831.320.9Physical activity frequencyAt most 2 times/week58.943.454.442.3At least 3 times/week41.156.645.657.7

Conclusion:

Although adolescents with JIA tend to become more physically active during the course of disease, on average they remain more inactive and spend significantly more time on SBM than their peers. Given that high SBM use was associated with lower self-reported psychosocial quality of life and higher disease activity, it is important to develop sustainable and effective interventions to reduce sedentary behaviors in this population.

References:

[1]Elmesmari R et al. Accelerometer measured levels of moderate-to-vigorous intensity physical activity and sedentary time in children and adolescents with chronic disease: A systematic review and meta-analysis. PLoS One 2017;12:e0179429.

Acknowledgments:

ICON is supported by a grant from the German Federal Ministry of Education and Research (FKZ 01 ER 1504A)

Disclosure of Interests: :

Florian Milatz: None declared, Ina Liedmann: None declared, Martina Niewerth: None declared, Jens Klotsche: None declared, Peter Haas: None declared, Frank Dressler: None declared, Rainer Berendes: None declared, Kirsten Moenkemoeller: None declared, Kirsten Minden Consultant of: GlaxoSmithKline, Sanofi, Speakers bureau: Roche

Attenuation correction for confocal laser scanning microscopy and its application in chromatography

The applicability of confocal laser scanning microscopy is limited, e.g. by attenuation of the excitation and the fluorescence emission beam. As a prerequisite for further processing and analysis of the obtained microscopic images, a new method is presented for correcting this attenuation. The correction is based on beam modelling and on a differential form of the modified Beer-Lambert law. It turns out that the intensity decay can be modelled as a double convolution of the microscopic image with the intensities of the excitation semibeam and the emission beam. Under weak assumptions made for the intensities of the fluorescent radiation and the detected signal, formulas for the attenuation correction and the attenuation simulation are derived. The method traces back to that one published by Roerdink which is modified concerning a more realistic beam modelling, avoiding the so-called weak attenuation expansion and considering fluorescence excitation throughout the light cone of the excitation beam. The applicability of the method is demonstrated for synthetic examples as well as microscopic images of chromatographic beads. It is shown that the new method can be successfully applied for reconstructing the true fluorophore distribution in specimens even if the microscopic images are affected by strong attenuation. LAY DESCRIPTION: The applicability of confocal laser scanning microscopy is limited by attenuation of the excitation and the fluorescence emission beam. As a prerequisite for further processing and analysis of the obtained microscopic images, a new method is presented for correcting this attenuation. The correction is based on modeling the excitation as well as the emission beam and on a modified Beer-Lambert law for beam attenuation. The applicability of the method is demonstrated for synthetic examples as well as microscopic images of chromatographic beads. It is shown that the new method can be successfully applied for reconstructing the true fluorophore distribution in specimens even if the microscopic images are affected by strong attenuation.

Favorable impact of natural killer cell reconstitution on chronic graft-versus-host disease and cytomegalovirus reactivation after allogeneic hematopoietic stem cell transplantation

Natural killer cells are the first lymphocyte subset to reconstitute, and play a major role in early immunity after allogeneic hematopoietic stem cell transplantation. Cells expressing the activating receptor NKG2C seem crucial in the resolution of cytomegalovirus episodes, even in the absence of T cells. We prospectively investigated natural killer-cell reconstitution in a cohort of 439 adult recipients who underwent non-T-cell-depleted allogeneic hematopoietic stem cell transplantation between 2005 and 2012. Freshly collected blood samples were analyzed 3, 6, 12 and 24 months after transplantation. Data were studied with respect to conditioning regimen, source of stem cells, underlying disease, occurrence of graft-versus-host disease, and profiles of cytomegalovirus reactivation. In multivariate analysis we found that the absolute numbers of CD56(bright) natural killer cells at month 3 were significantly higher after myeloablative conditioning than after reduced intensity conditioning. Acute graft-versus-host disease impaired reconstitution of total and CD56(dim) natural killer cells at month 3. In contrast, high natural killer cell count at month 3 was associated with a lower incidence of chronic graft-versus-host disease, independently of a previous episode of acute graft-versus-host disease and stem cell source. NKG2C(+)CD56(dim) and total natural killer cell counts at month 3 were lower in patients with reactivation of cytomegalovirus between month 0 and month 3, but expanded greatly afterwards. These cells were also less numerous in patients who experienced later cytomegalovirus reactivation between month 3 and month 6. Our results advocate a direct role of NKG2C-expressing natural killer cells in the early control of cytomegalovirus reactivation after allogeneic hematopoietic stem cell transplantation.

Effectiveness of whole grain consumption in the prevention of colorectal cancer: meta-analysis of cohort studies

The present work aimed to evaluate the effectiveness of whole grain consumption in preventing colorectal cancer. A systematic review with meta-analysis of 11 cohort studies was carried out. The age group of the population studied (1,719,590 participants) was between 25 and 76 years of age. The review evaluated the relative risks with the Cox proportional hazard model. The period of study varied from 6 to 16 years, where 7,745 persons developed colorectal cancer during the follow-up period. In the multivariate analysis, the highest quintile relative risk was 0.94 (95% confidence interval, 0.85-1.03), whereas that for the lowest quintile was 0.96 (95% confidence interval, 0.88-1.04). The location of tumors was also evaluated, with tumors in the colon demonstrating a relative risk of 0.93 (95% confidence interval, 0.83-1.02) and tumors in the recto a relative risk equal to 0.89 (95% confidence interval, 0.79-1.00). In this multivariate analysis, consumption of whole grains was inversely associated with the risk of developing colorectal cancer.

A century of leishmaniasis in Alpes-Maritimes, France

A century of publications on leishmaniasis in Alpes-Maritimes, in southern France, is here reviewed. Autochtonous human and canine leishmaniasis were first recognised in this département, which lies by the Mediterranean Sea and near the Italian border, in 1918 and 1925, respectively. The parasite responsible for the leishmaniasis, Leishmania infantum, is transmitted by Phlebotomus perniciosus and P. ariasi. The human leishmaniasis is zoonotic, with domestic dogs acting as the main 'reservoir' hosts. In prospective surveys over the last two decades, a mean of 12% of the domestic dogs checked in Alpes-Maritimes have been found seropositive for L. infantum but only about 50% of the seropositive animals showed any clinical signs of infection at the time of the surveys. During the last 30 years, 178 cases of human visceral leishmaniasis have been recorded in the area. Such cases are sporadic and often opportunistic, occurring predominantly in children (29% of the 178 cases) or HIV-positive subjects (31%). Recently, it has been demonstrated that, in Alpes-Maritimes, approximately 20% of those found seropositive in leishmanin skin tests are asymptomatic carriers, with amastigotes in their peripheral blood.

Determination of Alcohol Ethoxylate Components in Sewage Sludge

An analytical method has been developed for the determination of alcohol ethoxylate (AE) components in sewage sludge. The method has been extensively ring tested in several industrial laboratories and concentrations in sludge samples from a number of EU countries have been obtained. The method is based on a methanol soxhlet extraction of centrifuged sludge, which is then cleaned up using an alumina column, followed by derivatisation with naphthoyl chloride and a further alumina column clean-up. The extract is analysed using high performance liquid chromatography (HPLC) with fluorescence detection. The method is capable of determining alcohol ethoxylate components in the range of C12–C18 alkyl chain lengths with an ethoxylate chain of EO4 up to approximately EO20 in sludge samples. The detection limit is approximately 20–30 mg kg−1 of total AEs in dry weight of sludge. Using the method, sludges from several European Sewage Treatment Plants (STP) were analysed. The concentration of the AEs, which are primarily linear, in digestor inlet averaged 1164 mg kg−1 (550–2947 mg kg−1) and in outlet sludges the mean value obtained was 167 mg kg−1 (<22–468 mg kg−1). At those plants in which concentrations were monitored in both inlet and outlet sludges, removal of the AEs by anaerobic digestion at the STP averaged 82% (range 61–93%). The interlaboratory relative standard deviation of the procedure was around 40% for the digester sludges analysed. The method developed provides a more accurate estimate of the environmental level of AE components compared to existing colorimetric approaches, but the method will over-estimate the concentration of alcohol ethoxylates in sludges due to the non-specific nature of the detection. However, it is sufficiently robust and accurate to estimate alcohol ethoxylates in sludges and hence concentrations that could be applied to soil.

Dedicated vertical wind tunnel for the study of sedimentation of non-spherical particles

A dedicated 4-m-high vertical wind tunnel has been designed and constructed at the University of Geneva in collaboration with the Groupe de compétence en mécanique des fluides et procédés énergétiques. With its diverging test section, the tunnel is designed to study the aero-dynamical behavior of non-spherical particles with terminal velocities between 5 and 27 ms(-1). A particle tracking velocimetry (PTV) code is developed to calculate drag coefficient of particles in standard conditions based on the real projected area of the particles. Results of our wind tunnel and PTV code are validated by comparing drag coefficient of smooth spherical particles and cylindrical particles to existing literature. Experiments are repeatable with average relative standard deviation of 1.7%. Our preliminary experiments on the effect of particle to fluid density ratio on drag coefficient of cylindrical particles show that the drag coefficient of freely suspended particles in air is lower than those measured in water or in horizontal wind tunnels. It is found that increasing aspect ratio of cylindrical particles reduces their secondary motions and they tend to be suspended with their maximum area normal to the airflow. The use of the vertical wind tunnel in combination with the PTV code provides a reliable and precise instrument for measuring drag coefficient of freely moving particles of various shapes. Our ultimate goal is the study of sedimentation and aggregation of volcanic particles (density between 500 and 2700 kgm(-3)) but the wind tunnel can be used in a wide range of applications.

Effects of perfusion and cyclic compression on in vitro tissue engineered meniscus implants

PURPOSE

The purpose of this study was to investigate the influence of continuous perfusion and mechanical stimulation on bone marrow stromal cells seeded on a collagen meniscus implant.

METHODS

Bone marrow aspirates from 6 donors were amplified in vitro. 10(6) human BMSC were distributed on a collagen meniscus implant. Scaffolds were cultured under static conditions (control) or placed into a bioreactor system where continuous perfusion (10 ml/min) or perfusion and mechanical stimulation (8 h of 10% cyclic compression at 0.5 Hz) were administered daily. After 24 h, 7 and 14 days, cell proliferation, synthesis of procollagen I and III peptide (PIP, PIIIP), histology, and the equilibrium modulus of the constructs were analyzed.

RESULTS

Proliferation demonstrated a significant increase over time in all groups (p < 0.001). PIP synthesis was found to increase from 0.1 ± 0.0 U/ml/g protein after 24 h to 2.0 ± 0.5 (perfusion), 3.8 ± 0.3 (mechanical stimulation), and 1.8 ± 0.2 U/ml/g protein (static control, lower than perfusion and mechanical stimulation, p < 0.05). These differences were also evident after 2 weeks (2.7 ± 0.3, 4.0 ± 0.6, and 1.8 ± 0.2 U/ml/g protein, p < 0.01); PIIIP synthesis was found to increase from 0.1 ± 0.0 U/ml/g protein after 24 h to 2.9 ± 0.7 (perfusion), 3.1 ± 0.9 (mechanical stimulation), and 1.6 ± 0.3 U/ml/g protein (controls) after 1 week and remained significantly elevated under the influence of perfusion and mechanical stimulation (p < 0.01) after 2 weeks. Mechanical stimulation increased the equilibrium modulus more than static culture and perfusion after 2 weeks (24.7 ± 7.6; 12.3 ± 3.7; 15.4 ± 2.6 kPa; p < 0.02).

CONCLUSION

Biomechanical stimulation and perfusion have impact on collagen scaffolds seeded with BMSCs. Cell proliferation can be enhanced using continuous perfusion and differentiation is fostered by mechanical stimulation.

Fast quantitative single-molecule detection at ultralow concentrations

The applicability of single-molecule fluorescence assays in liquids is limited by diffusion to concentrations in the low picomolar range. Here, we demonstrate quantitative single-molecule detection at attomolar concentrations within 1 min by excitation and detection of fluorescence through a single-mode optical fiber in presence of turbulent flow. The combination of high detectability and short measurement times promises applications in ultrasensitive assays, sensors, and point-of-care medical diagnostics.

Complement factor H gene polymorphisms and Chlamydia pneumoniae infection in age-related macular degeneration

PURPOSE

To investigate the association of the complement factor H gene (CFH)Y402H polymorphism and age-related macular degeneration (AMD) in the Austrian population (Caucasoid descent), and to determine whether there is an association between exposure to Chlamydia pneumoniae-responsible for up to 20% of community-acquired pneumoniae-and the AMD-associated CFHrisk polymorphism.

METHODS

Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism analysis in 75 unrelated AMD patients and compared with 75 healthy, age-matched control subjects. C. pneumoniaeserum IgG was tested by ELISA (R&D) in both groups. The association between the CFHY402H genetic polymorphism and the disease was examined by chi (2)-test and logistic regression.

RESULTS

CFH Y402H genotypefrequencies differed significantly between AMD patients and healthy controls (1277 TT, 22.7%; 1277 TC, 53.3%; and 1277 CC, 22.7% in the AMD group; 1277 TT, 48.0%; 1277 TC, 38.7%; and 1277 CC, 13.3% in the control group) showing a P-value <0.005 (OR:2.920/3.811).No association was found between a positive C. pneumoniae titre and AMD (P=0.192), nor was any association found between C. pneumoniae and the CFH Y402H polymorphism.

CONCLUSIONS

Our data confirm that the CFHY402H polymorphism is a risk factor for AMD in the Austrian population with a higher frequency of the Y402 polymorphism in AMD patients. No association between preceding C. pneumoniaeinfection and diagnosed AMD was found.

Oxidative stress mediates a reduced expression of the activating receptor NKG2D in NK cells from end-stage renal disease patients

To characterize the immune defect of patients with end-stage renal disease (ESRD), we performed NK cell subset analysis in 66 patients with ESRD treated by hemodialysis (n = 59) or peritoneal dialysis (n = 7). Compared with healthy blood donors, patients undergoing chronic dialysis showed a profound decrease in NKG2D(+) cells within both the CD8(+) T cell (58% vs 67%, p = 0.03) and NK cell (39% vs 56%, p = 0.002) populations. CD56(dim) cells, which comprise the majority of NK cells in the periphery, were more affected in this regard than were CD56(bright) cells. Uremic serum could decrease NKG2D expression on NK cells from healthy donors. Among factors that could contribute to the decrease in NKG2D expression in ESRD patients, reactive oxygen species (ROS) play a major role. We found that catalase could reverse the effects of uremic serum on NKG2D expression (p < 0.001) and that ROS down-regulated NKG2D at the mRNA level and at the NK cell surface. Additionally, ESRD patients had both increased membrane-bound MHC class I-related chain A (MICA) on monocytes (p = 0.04) and increased soluble MICA (203 pg/ml vs 110 pg/ml; p < 0.001). Both ROS and uremic serum could significantly increase in vitro the expression of the NKG2D ligand MICA on the renal epithelial cell line HK-2. Taken together, these studies suggest for the first time that both low NKG2D expression and up-regulation of its ligand MICA are related to ROS production and may be involved in the immune deficiency of ESRD patients.

An unusual CD56(bright) CD16(low) NK cell subset dominates the early posttransplant period following HLA-matched hematopoietic stem cell transplantation

The expansion of the cytokine-producing CD56(bright) NK cell subset is a main feature of lymphocyte reconstitution after allogeneic hematopoietic stem cell transplantation (HSCT). We investigated phenotypes and functions of CD56(bright) and CD56(dim) NK subsets from 43 HLA-matched non-T cell-depleted HSCT donor-recipient pairs. The early expansion of CD56(bright) NK cells gradually declined in the posttransplant period but still persisted for at least 1 year and was characterized by the emergence of an unusual CD56(bright)CD16(low) subset with an intermediate maturation profile. The activating receptors NKG2D and NKp46, but also the inhibitory receptor NKG2A, were overexpressed compared with donor CD56(bright) populations. Recipient CD56(bright) NK cells produced higher amounts of IFN-gamma than did their respective donors and were competent for degranulation. Intracellular perforin content was increased in CD56(bright) NK cells as well as in T cells compared with donors. IL-15, the levels of which were increased in the posttransplant period, is a major candidate to mediate these changes. IL-15 serum levels and intracellular T cell perforin were significantly higher in recipients with acute graft-vs-host disease. Altogether, CD56(bright) NK cells postallogeneic HSCT exhibit peculiar phenotypic and functional properties. Functional interactions between this subset and T cells may be important in shaping the immune response after HSCT.

Detection of transient events in the presence of background noise

We describe a method to detect and count transient burstlike signals in the presence of a significant stationary noise. To discriminate a transient signal from the background noise, an optimum threshold is determined using an iterative algorithm that yields the probability distribution of the background noise. Knowledge of the probability distribution of the noise then allows the determination of the number of transient events with a quantifiable error (wrong-positives). We apply the method, which does not rely on the choice of free parameters, to the detection and counting of transient single-molecule fluorescence events in the presence of a strong background noise. The method will be of importance in various ultra sensing applications.

Assessing the impact of a downscaled climate change simulation on the fish fauna in an Inner-Alpine River

This study assesses the impact of a changing climate on fish fauna by comparing the past mean state of fish assemblage to a possible future mean state. It is based on (1) local scale observations along an Inner-Alpine river called Mur, (2) an IPCC emission scenario (IS92a), implemented by atmosphere-ocean global circulation model (AOGCM) ECHAM4/OPYC3, and (3) a model-chain that links climate research to hydrobiology. The Mur River is still in a near-natural condition and water temperature in summer is the most important aquatic ecological constraint for fish distribution. The methodological strategy is (1) to use downscaled air temperature and precipitation scenarios for the first half of the twenty-first century, (2) to establish a model that simulates water temperature by means of air temperature and flow rate in order to generate water temperature scenarios, and (3) to evaluate the impact on fish communities using an ecological model that is driven by water temperature. This methodology links the response of fish fauna to an IPCC emission scenario and is to our knowledge an unprecedented approach. The downscaled IS92a scenarios show increased mean air temperatures during the whole year and increased precipitation totals during summer, but reduced totals for the rest of the annual cycle. These changes result in scenarios of increased water temperatures, an altered annual cycle of flow rate, and, in turn, a 70 m displacement in elevation of fish communities towards the river's head. This would enhance stress on species that rely on low water temperatures and coerce cyprinid species into advancing against retreating salmonids. Hyporhithral river sectors would turn into epipotamal sectors. Grayling (Thymallus thymallus) and Danube salmon (Hucho hucho), presently characteristic for the Mur River, would be superceded by other species. Native brown trout (Salmo trutta), already now under pressure of competition, may be at risk of losing its habitat in favour of invaders like the exotic rainbow trout (Oncorhynchus mykiss), which are better adapted to higher water temperatures. Projected changes in fish communities suggest an adverse influence on salmonid sport fishing and a loss in its high economic value.

Activating KIR genes are associated with CMV reactivation and survival after non-T-cell depleted HLA-identical sibling bone marrow transplantation for malignant disorders

Combinations of HLA and killer immunoglobulin-like receptors (KIR) may affect outcome in T-cell depleted haematopoietic stem cell transplantation (HSCT). The KIR gene family includes inhibitory (KIR2DL and 3DL) and activating receptors (KIR2DS). Ligands are HLA-C (KIR2D) and HLA-Bw4 (KIR3DL1) for inhibitory KIR and are still unknown for activating KIR. The impact of activating KIR genotypes from donor and recipient is poorly documented in HSCT outcome. Here, HLA and KIR genotypes were determined in 131 pairs from non-T-cell depleted HLA-identical sibling HSCT. No effect of 'missing KIR ligand' was detected on acute graft-versus-host disease (GVHD), relapse, survival or infections even in myeloid malignancies. However, additional activating KIR genes in the donor compared to the recipient's genotype or an identity between donor and recipient activating KIR genotypes was associated with a lower transplant-related mortality (TRM) (P=0.005) and in a multivariate analysis with a better survival (P=0.02, HR=0.28; P=0.013, HR=0.29) and a lower incidence of cytomegalovirus (CMV) reactivation (P=0.009, HR=0.36). These data highlight the impact of donor-activating KIR genes on TRM, overall survival and CMV reactivation in HLA-identical sibling HSCT.