Long-term exposure to traffic-related air pollution and non-accidental mortality: A systematic review and meta-analysis

BACKGROUND

The health effects of traffic-related air pollution (TRAP) continue to be of important public health interest across the globe. Following its 2010 review, the Health Effects Institute appointed a new expert Panel to systematically evaluate the epidemiological evidence regarding the associations between long-term exposure to TRAP and selected health outcomes. This paper describes the main findings of the systematic review on non-accidental mortality.

METHODS

The Panel used a systematic approach to conduct the review. An extensive search was conducted of literature published between 1980 and 2019. A new exposure framework was developed to determine whether a study was sufficiently specific to TRAP, which included studies beyond the near-roadway environment. We performed random-effects meta-analysis when at least three estimates were available of an association between a specific exposure and outcome. We evaluated confidence in the evidence using a modified Office of Health Assessment and Translation (OHAT) approach, supplemented with a broader narrative synthesis.

RESULTS

Thirty-six cohort studies were included. Virtually all studies adjusted for a large number of individual and area-level covariates-including smoking, body mass index, and individual and area-level socioeconomic status-and were judged at a low or moderate risk for bias. Most studies were conducted in North America and Europe, and a few were based in Asia and Australia. The meta-analytic summary estimates for nitrogen dioxide, elemental carbon and fine particulate matter-pollutants with more than 10 studies-were 1.04 (95% CI 1.01, 1.06), 1.02 (1.00, 1.04) and 1.03 (1.01, 1.05) per 10, 1 and 5 µg/m³, respectively. Effect estimates are interpreted as the relative risk of mortality when the exposure differs with the selected increment. The confidence in the evidence for these pollutants was judged as high, because of upgrades for monotonic exposure-response and consistency across populations. The consistent findings across geographical regions, exposure assessment methods and confounder adjustment resulted in a high confidence rating using a narrative approach as well.

CONCLUSIONS

The overall confidence in the evidence for a positive association between long-term exposure to TRAP and non-accidental mortality was high.

Using machine learning methods and EEG to discriminate aircraft pilot cognitive workload during flight

Pilots of aircraft face varying degrees of cognitive workload even during normal flight operations. Periods of low cognitive workload may be followed by periods of high cognitive workload and vice versa. During such changing demands, there exists potential for increased error on behalf of the pilots due to periods of boredom or excessive cognitive task demand. To further understand cognitive workload in aviation, the present study involved collection of electroencephalogram (EEG) data from ten (10) collegiate aviation students in a live-flight environment in a single-engine aircraft. Each pilot possessed a Federal Aviation Administration (FAA) commercial pilot certificate and either FAA class I or class II medical certificate. Each pilot flew a standardized flight profile representing an average instrument flight training sequence. For data analysis, we used four main sub-bands of the recorded EEG signals: delta, theta, alpha, and beta. Power spectral density (PSD) and log energy entropy of each sub-band across 20 electrodes were computed and subjected to two feature selection algorithms (recursive feature elimination (RFE) and lasso cross-validation (LassoCV), and a stacking ensemble machine learning algorithm composed of support vector machine, random forest, and logistic regression. Also, hyperparameter optimization and tenfold cross-validation were used to improve the model performance, reliability, and generalization. The feature selection step resulted in 15 features that can be considered an indicator of pilots' cognitive workload states. Then these features were applied to the stacking ensemble algorithm, and the highest results were achieved using the selected features by the RFE algorithm with an accuracy of 91.67% (± 0.11), a precision of 93.89% (± 0.09), recall of 91.67% (± 0.11), F-score of 91.22% (± 0.12), and the mean ROC-AUC of 0.93 (± 0.06). The achieved results indicated that the combination of PSD and log energy entropy, along with well-designed machine learning algorithms, suggest the potential for the use of EEG to discriminate periods of the low, medium, and high workload to augment aircraft system design, including flight automation features to improve aviation safety.

Long-term exposure to traffic-related air pollution and stroke: A systematic review and meta-analysis

BACKGROUND

Stroke remains the second cause of death worldwide. The mechanisms underlying the adverse association of exposure to traffic-related air pollution (TRAP) with overall cardiovascular disease may also apply to stroke. Our objective was to systematically evaluate the epidemiological evidence regarding the associations of long-term exposure to TRAP with stroke.

METHODS

PubMed and LUDOK electronic databases were searched systematically for observational epidemiological studies from 1980 through 2019 on long-term exposure to TRAP and stroke with an update in January 2022. TRAP was defined according to a comprehensive protocol based on pollutant and exposure assessment methods or proximity metrics. Study selection, data extraction, risk of bias (RoB) and confidence assessments were conducted according to standardized protocols. We performed meta-analyses using random effects models; sensitivity analyses were assessed by geographic area, RoB, fatality, traffic specificity and new studies.

RESULTS

Nineteen studies were included. The meta-analytic relative risks (and 95% confidence intervals) were: 1.03 (0.98-1.09) per 1 μg/m³ EC, 1.09 (0.96-1.23) per 10 μg/m³ PM₁₀, 1.08 (0.89-1.32) per 5 μg/m³ PM_2.5, 0.98 (0.92; 1.05) per 10 μg/m³ NO₂ and 0.99 (0.94; 1.04) per 20 μg/m³ NO_x with little to moderate heterogeneity based on 6, 5, 4, 7 and 8 studies, respectively. The confidence assessments regarding the quality of the body of evidence and separately regarding the presence of an association of TRAP with stroke considering all available evidence were rated low and moderate, respectively.

CONCLUSION

The available literature provides low to moderate evidence for an association of TRAP with stroke.

Intrinsic cell rheology drives junction maturation

A fundamental property of higher eukaryotes that underpins their evolutionary success is stable cell-cell cohesion. Yet, how intrinsic cell rheology and stiffness contributes to junction stabilization and maturation is poorly understood. We demonstrate that localized modulation of cell rheology governs the transition of a slack, undulated cell-cell contact (weak adhesion) to a mature, straight junction (optimal adhesion). Cell pairs confined on different geometries have heterogeneous elasticity maps and control their own intrinsic rheology co-ordinately. More compliant cell pairs grown on circles have slack contacts, while stiffer triangular cell pairs favour straight junctions with flanking contractile thin bundles. Counter-intuitively, straighter cell-cell contacts have reduced receptor density and less dynamic junctional actin, suggesting an unusual adaptive mechano-response to stabilize cell-cell adhesion. Our modelling informs that slack junctions arise from failure of circular cell pairs to increase their own intrinsic stiffness and resist the pressures from the neighbouring cell. The inability to form a straight junction can be reversed by increasing mechanical stress artificially on stiffer substrates. Our data inform on the minimal intrinsic rheology to generate a mature junction and provide a springboard towards understanding elements governing tissue-level mechanics.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Long-term exposure to traffic-related air pollution and selected health outcomes: A systematic review and meta-analysis

The health effects of traffic-related air pollution (TRAP) continue to be of important public health interest. Following its well-cited 2010 critical review, the Health Effects Institute (HEI) appointed a new expert Panel to systematically evaluate the epidemiological evidence regarding the associations between long-term exposure to TRAP and selected adverse health outcomes. Health outcomes were selected based on evidence of causality for general air pollution (broader than TRAP) cited in authoritative reviews, relevance for public health and policy, and resources available. The Panel used a systematic approach to search the literature, select studies for inclusion in the review, assess study quality, summarize results, and reach conclusions about the confidence in the evidence. An extensive search was conducted of literature published between January 1980 and July 2019 on selected health outcomes. A new exposure framework was developed to determine whether a study was sufficiently specific to TRAP. In total, 353 studies were included in the review. Respiratory effects in children (118 studies) and birth outcomes (86 studies) were the most commonly studied outcomes. Fewer studies investigated cardiometabolic effects (57 studies), respiratory effects in adults (50 studies), and mortality (48 studies). The findings from the systematic review, meta-analyses, and evaluation of the quality of the studies and potential biases provided an overall high or moderate-to-high level of confidence in an association between long-term exposure to TRAP and the adverse health outcomes all-cause, circulatory, ischemic heart disease and lung cancer mortality, asthma onsetin chilldren and adults, and acute lower respiratory infections in children. The evidence was considered moderate, low or very low for the other selected outcomes. In light of the large number of people exposed to TRAP - both in and beyond the near-road environment - the Panel concluded that the overall high or moderate-to-high confidence in the evidence for an association between long-term exposure to TRAP and several adverse health outcomes indicates that exposures to TRAP remain an important public health concern and deserve greater attention from the public and from policymakers.

Management strategies for adult patients with dental anxiety in the dental clinic: a systematic review

Anxiety is an adaptive emotional response to potentially threatening or dangerous situations; moderated by the sympathetic nervous system. Dental anxiety is common and presents before, during or after dental treatment. The physiological response includes an increase in heart rate, blood pressure, respiratory rate, and cardiac output. Consequently, extensive distress leads to avoidance of dental treatment and multiple failed appointments, impacting both oral and general health. Dental anxiety can generate a variety of negative consequences for both the dentist and the patient. Evidence-based strategies are essential for mitigating and relieving anxiety in the dental clinic. Psychotherapeutic behavioural strategies can modify the patient's experience through a minimally invasive approach with nil or negligible side effects, depending on patient characteristics, anxiety level and clinical situations. These therapies involve muscle relaxation, guided imagery, physiological monitoring, utilizing biofeedback, hypnosis, acupuncture, distraction and desensitization. Pharmacological intervention utilizes either relative analgesia (nitrous oxide), conscious intravenous sedation or oral sedation, which can have undesirable side effects, risks and contraindications. These modalities increase the cost and availability of dental treatment.

[Breathing: Ambient Air Pollution and Health - Part III]

The third part of the DGP statement introduces the current body of knowledge on less studied health outcomes associated with exposure to ambient air pollution: the negative impact on metabolism leading to impaired glucose tolerance and diabetes as well as contribution to the development of neurodegenerative disorders and delayed cognitive function in children. Furthermore, prenatal exposure and adverse effects on mother and child are addressed. Finally, the currently discussed biological mechanisms underlying various health effects associated with exposure to air pollution are described.Differing, but often complementary biological mechanisms create the basis for the diverse health outcomes caused by air pollution. Oxidative stress and a subclinical inflammatory response in the lungs and on a systemic level ("low-grade systemic inflammation") are considered to be key mechanisms. They promote secondary alterations in the body, such as vascular or metabolic processes, and may also result in the currently studied epigenetic phenomena or neuroinflammation. In this context, the health significance of soluble particulate matter and the role of ultrafine particles translocated across biological membranes into blood vessel and transported via the circulation to secondary target organs, such as liver, brain or the fetus, are intensively discussed.Diabetes is one of the leading chronic diseases worldwide, with a prevalence of almost 14 % in Germany. Although lifestyle factors are the main causes, current evidence suggests that long-term exposure to air pollution may additionally increase the risk for type 2 diabetes. Supporting evidence for a causal role of air pollution is provided by studies addressing the regulation of the blood glucose levels in metabolically healthy participants, insulin sensitivity, or pregnancy-related diabetes. Experimental studies provide further support for plausible biological mechanisms. However, prospective studies are needed to gain more evidence, taking multiple lifestyle and environmental factors, such as green space and noise, and an improved individual exposure assessment into account.The aging population has an increased risk of neurodegenerative diseases. First studies point towards a contribution of chronic exposure to air pollution, specifically by particulate matter. Several studies report its association with decreased neurocognitive capacity or an increased prevalence of dementia or Alzheimer's disease in adults. However, the studies are inhomogeneous regarding design, exposure and outcome, leading to inconsistent results. With respect to the influence on neurocognitive development of children, first studies suggest an association between the level of air pollution, e. g. at school, and delayed cognitive development.Even though the evidence for the different biological endpoints during pregnancy is still heterogeneous, the studies generally point towards an adverse impact of air pollution on the maternal and fetal organisms. The strongest evidence exists for low birth weight, with small effect sizes of only some grams, and for a higher incidence of reduced birth weight (< 2500 g). An increased risk for gestational hypertension and preeclampsia underscores the possible impact of exposure to air pollution on the maternal organism. However, the current body of evidence does not yet allow a final conclusion on the influence of intrauterine exposure to air pollution regarding early childhood lung function and development of allergies, particularly in light of the fact that it is hard to distinguish in epidemiological studies between the effects of pre- and postnatal exposure.

[Breathing: Ambient Air Pollution and Health - Part II]

The second part of the DGP-statement on adverse health effects of ambient air pollution provides an overview of the current ambient air quality in Germany and its development in the past 20 years. Further, effects of air pollution on the cardiovascular system und underlying pathophysiological mechanisms are introduced. Air pollutants form a highly complex and dynamic system of thousands of organic and inorganic components from natural and anthropogenic sources. The pollutants are produced locally or introduced by long-range transport over hundreds of kilometers and are additionally subjected to local meteorological conditions. According to air quality regulations ambient air quality is monitored under uniform standards including immission of particulate matter, up to 2.5 µm (PM_2.5) or 10 µm (PM₁₀) in aerodynamic diameter, and of nitrogen dioxide (NO₂) or ozone (O₃). The clean air measures of recent years led to a continuous decline of air pollution in the past 20 years in Germany. Accordingly, the focus is nowadays directed at population-related health hazards caused by low concentrations of air pollution. Exceeded limits for sulfur dioxide, carbon monoxide, benzene and lead are not detected anymore. Also the number of days with increased ozone concentration declined, although the annual mean concentration is unaltered. Decreasing concentrations of particulate matter and NO₂ have been observed, however, about 40 % of the monitoring stations at urban traffic sites still measure values exceeding current limits for NO₂. Moreover, the stricter, solely health-based WHO-standards for PM_2.5, PM₁₀ and NO₂ are still not met so that an optimal protection from air pollution-related health hazards is currently not given for the German population. In recent years, the findings of numerous cross-sectional and longitudinal studies underscored adverse effects of air pollution on the cardiovascular system, especially for particulate matter, although the level of evidence still varies for the different health outcomes. Further, the studies show that cardiovascular health hazards on the population level are of higher relevance than those for the respiratory system. The existing evidence for cardiovascular mortality, hospitalization, ischemic heart diseases, myocardial infarction and stroke can be regarded as strong, while that for heart failure is rather moderate. While the evidence for air pollution-related short-term alteration of the cardiac autonomic balance can be considered as sufficient, long-term effects are still unclear. Likewise, the heterogeneous findings on air pollution-related arrhythmia do currently not allow a distinct conclusion in this regard. A large number of studies support the observation that both, short- and long-term air pollution exposure contribute to increased blood pressure, may impair vascular homeostasis, induce endothelial dysfunction and promote the progression of atherosclerotic lesions. These effects provide reasonable biological explanation for the fatal events associated with exposure to air pollution. Short-term exposure may not pose a significant risk on healthy individuals but may be considered as precursor for fatal events in susceptible populations, while repetitive or long-term exposure may contribute to the development of cardiovascular diseases even in healthy subjects.

Could we expect new praziquantel derivatives? A meta pharmacometrics/pharmacoinformatics analysis of all antischistosomal praziquantel derivatives found in the literature

Praziquantel (PZQ) is the first line drug for the treatment of human Schistosoma spp. worm infections. However, it suffers from low activity towards immature stages of the worm, and its prolonged use induces resistance/tolerance. During the last 40 years, 263 PZQ analogues have been synthesized and tested against Schistosoma spp. worms, but less than 10% of them showed significant activity. Here, we propose a rationalization of the chemical space of the PZQ derivatives by a ligand-based approach. First, we constructed an in-house database with all PZQ derivatives available in the literature. This analysis shows a high heterogeneity in the data. Fortunately, all studies include PZQ as a reference, permitting the classification of compounds into three classes according to their activities. Models involving ligand-based pharmacophore and logistic regression were performed. Five physicochemical parameters were identified as the best to explain the biological activity. In the end, we proposed new PZQ derivatives with modifications at positions 1 and 7, we analysed them with our models, and we observed that they can be more active than the previously synthesized derivatives. The main goal of this work was to conduct the most valuable meta-pharmacometrics/pharmacoinformatics analysis with all Praziquantel medicinal chemistry data available in the literature.

[Breathing: Ambient Air Pollution and Health - Part I]

Die Exposition gegenüber Luftschadstoffen wird von der Weltgesundheitsorganisation weltweit als eine führende Gesundheitsgefährdung und als der wichtigste umweltbedingte Risikofaktor mit besonders hoher Krankheitslast in Ländern mit niedrigem und mittlerem Einkommen angesehen.

Die Luftschadstoffbelastung besteht aus hochkomplexen Gemischen verschiedenster organischer und anorganischer Bestandteile natürlichen oder anthropogenen Ursprungs, die lokal entstehen oder durch Ferntransport über hunderte von Kilometern regional eingebracht werden können. Zusätzlich wird die Schadstoffkonzentration durch die regionalen, meteorologischen Verhältnisse beeinflusst. Dementsprechend können Schadstoffkonzentration und Zusammensetzung an einem Ort deutlich variieren, zeigen aber typischerweise einen Tages-, Wochen- und Jahresgang.

Mittels gesetzlicher Grenzwerte wie in der „Air Quality Directive“ der Europäischen Union festgelegt, soll eine Gesundheitsgefährdung der Bevölkerung durch die Schadstoffe minimiert werden. Allerdings weichen die Grenzwerte der Europäischen Union von den Empfehlungen der WHO insbesondere für Feinstaub deutlich nach oben ab.

Zur Abschätzung der Luftschadstoffbelastung wird auf einzelne Indikatoren zurückgegriffen, die die partikuläre, wie Feinstaub bis 2,5 µm (PM2.5) bzw. bis 10 µm aerodynamischen Durchmesser (PM10), und die gasförmige Belastung, wie Stickstoffdioxid (NO2) und Ozon (O3), charakterisieren. Für die meisten Luftschadstoffe wurden über die letzten Jahrzehnte in der westlichen Welt abfallende Konzentrationen beobachtet, sodass hier v. a. die Gesundheitsgefährdung bei geringerer Schadstoffbelastung im Vordergrund steht. Insbesondere Ballungsgebiete in Deutschland leiden aber noch unter erhöhter Luftverschmutzung.

Zahlreiche Studien haben in den letzten Jahrzehnten schädliche Auswirkungen von Luftschadstoffen auf die Gesundheit der Bevölkerung belegt. Die Auswirkungen betreffen v. a. den Atemtrakt und das kardiovaskuläre System und reichen von unspezifischen Atemwegs- und kardiovaskulären Symptomen über Beeinträchtigungen der Lungenfunktion, vermehrter Medikamenteneinnahme und akuter Exazerbation von vorbestehenden Lungenerkrankungen, Herzinfarkten und Schlaganfällen bis hin zu Todesfällen. Neuere Studien weisen auf weitere Gesundheitsendpunkte, wie z. B. Atherosklerose, Einschränkungen des fetalen Wachstums, der kognitiven Funktion und neuronalen Entwicklung, Diabetes mellitus sowie auf ein verbessertes Verständnis der zugrundeliegenden pathophysiologischen Mechanismen hin.

In der „Global Burden of Disease Study“ von 2015 wird die Bedeutung der Luftschadstoffbelastung für Mortalität und Morbidität v. a. durch chronische Erkrankungen quantifiziert. Bei der vorzeitigen Mortalität, v. a. aufgrund von kardiovaskulären Todesursachen, lag PM2.5 in der Außenluft weltweit auf Rang 5, unmittelbar hinter den allgemeinen Risikofaktoren erhöhter Blutdruck, Rauchen sowie erhöhte Glukose- und Cholesterinwerte. In Deutschland liegt die Krankheitslast durch Luftverschmutzung an zehnter Stelle der Risikofaktoren und ist damit auch hierzulande der wichtigste umweltbezogene Risikofaktor. Entsprechend zeigen Studien, dass der Einfluss von Luftschadstoffen die Sterblichkeit in Europa erhöht und die mittlere Lebenserwartung um etwa ein Jahr reduzieren kann.

In dem hier vorgestellten Positionspapier fasst die Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin den aktuellen Wissensstand zu den Gesundheitseffekten von Luftschadstoffen zusammen und leitet daraus Empfehlungen für einen umweltbezogenen Gesundheitsschutz ab. Der hier vorgestellte erste Teil fokussiert sich auf allgemeine Grundlagen und die Wirkungen im Atemtrakt.

CPP-ACP Promotes SnF2 Efficacy in a Polymicrobial Caries Model

Dental caries is associated with plaque dysbiosis, leading to an increase in the proportions of acidogenic and aciduric bacteria at the expense of alkali-generating commensal species. Stannous fluoride (SnF₂) slows the progression of caries by remineralization of early lesions but has also been suggested to inhibit glycolysis of aciduric bacteria. Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) promotes fluoride remineralization by acting as a salivary biomimetic that releases bioavailable calcium and phosphate ions, and the peptide complex has also been suggested to modify plaque composition. We developed a polymicrobial biofilm model of caries using 6 bacterial species representative of supragingival plaque that were cultured on sound human enamel and pulsed with sucrose 4 times a day to produce a high cariogenic challenge. We used this model to explore the mechanisms of action of SnF₂ and CPP-ACP. Bacterial species in the biofilms were enumerated with 16S rRNA gene sequence analyses, and mineral loss and lesion formation were determined in the enamel directly under the polymicrobial biofilms via transverse microradiography. The model tested the twice-daily addition of SnF₂, CPP-ACP, or both. SnF₂ treatment reduced demineralization by 50% and had a slight effect on the composition of the polymicrobial biofilm. CPP-ACP treatment caused a similar inhibition of enamel demineralization (50%), a decrease in Actinomyces naeslundii and Lactobacillus casei abundance, and an increase in Streptococcus sanguinis and Fusobacterium nucleatum abundance in the polymicrobial biofilm. A combination of SnF₂ and CPP-ACP resulted in a greater suppression of the acidogenic and aciduric bacteria and a significant 72% inhibition of enamel demineralization.

SULFATION PATHWAYS: Formation and hydrolysis of sulfonated estrogens in the porcine testis and epididymis

Boars exhibit high concentrations of sulfonated estrogens (SE) mainly originating from the testicular-epididymal compartment. Intriguingly, in porcine Leydig cells, sulfonation of estrogens is colocalized with aromatase and steroid sulfatase (STS), indicating that de novo synthesis of unconjugated estrogens (UE), their sulfonation and hydrolysis of SE occur within the same cell type. So far in boars no plausible concept concerning the role of SE has been put forward. To obtain new information on SE formation and hydrolysis, the porcine testicular-epididymal compartment was screened for the expression of the estrogen-specific sulfotransferase SULT1E1 and STS applying real-time RT-qPCR, Western blot and immunohistochemistry. The epididymal head was identified as the major site of SULT1E1 expression, whereas in the testis, it was virtually undetectable. However, SE tissue concentrations are clearly consistent with the testis as the predominant site of estrogen sulfonation. Results from measurements of estrogen sulfotransferase activity indicate that in the epididymis, SULT1E1 is the relevant enzyme, whereas in the testis, estrogens are sulfonated by a different sulfotransferase with a considerably lower affinity. STS expression and activity was high in the testis (Leydig cells, rete testis epithelium) but also present throughout the epididymis. In the epididymis, SULT1E1 and STS were colocalized in the ductal epithelium, and there was evidence for their apocrine secretion into the ductal lumen. The results suggest that in porcine Leydig cells, SE may be produced as a reservoir to support the levels of bioactive UE via the sulfatase pathway during periods of low activity of the pulsatile testicular steroidogenesis.

Suitability of group-level oral fluid sampling in ruminant populations for lumpy skin disease virus detection

The geographic expansion of Lumpy skin disease (LSD) from the near East into the European Union highlighted again the need for appropriate disease detection tools applicable to animal host populations where access to individual animals is difficult. This is of particular importance considering that the clinical manifestation of LSD is often mild making early disease detection challenging under the above-mentioned conditions. Building on positive experiences of group-level oral fluid sampling for pathogen detection as it is known to work for swine herds and wild boar, the concept was transferred to ruminants. Two groups of six cattle were infected experimentally with Lumpy skin disease virus (LSDV) under controlled conditions. Blood as well as oropharyngeal and nasal swab samples were collected at regular intervals. Group samples were obtained by placing cotton gauze around a salt lick block provided commonly as dietary supplement. Pieces of the gauze with visible signs of manipulation were tested in parallel to samples obtained from individual animals. Genome load analysis by qPCR technology revealed LSDV detection window starting from day 2 post infection until day 28 post infection, the end of the animal trial. At the individual level, detection periods varied between animals and type of sample and included intermitted detection. The accumulative character of the alternative sampling method makes it suitable to detect LSDV DNA at group-level even at times of the infection where a selective sampling of individuals from a group - as normally done in LSD surveillance - would have most likely failed in the detection.

Using hydrodynamic focusing to predictably alter the diameter of synthetic silk fibers

Spiders and silkworms provide a model of superior processing for multifunctional and highly versatile high-performance fibers. Mimicking the spider's complex control system for chemical and mechanical gradients has remained an ongoing obstacle for synthetic silk production. In this study, the use of hydrodynamic fluid focusing within a 3D printed biomimetic spinning system to recapitulate the biological spinneret is explored and shown to produce predictable, small diameter fibers. Mirroring in silico fluid flow simulations using a hydrodynamic microfluidic spinning technique, we have developed a model correlating spinning rates, solution viscosity and fiber diameter outputs that will significantly advance the field of synthetic silk fiber production. The use of hydrodynamic focusing to produce controlled output fiber diameter simulates the natural silk spinning process and continues to build upon a 3D printed biomimetic spinning platform.

Downregulation von LH bei der Hündin nach Anwendung des GnRH-Agonisten Buserelin in Implantatform

Gegenstand und Ziel: Darstellung der Downregulation von LH bei der Hündin nach Anwendung eines Slow-Release-GnRH-Implantats mit dem Wirkstoff Buserelin. Material und Methoden: Zur Ausschaltung negativ rückkoppelnder Wirkungen endogener Sexualhormone wurden neun Hündinnen ovariohysterektomiert. Zur Anwendung kam der Wirkstoff Buserelinacetat in Form des Slow-Release-Implantats Profact Depot®, wobei jeweils drei Hündinnen Implantate mit 3,3 mg, 6,6 mg oder 13,2 mg subkutan appliziert wurden. Die Charakterisierung der Verfügbarkeit von LH erfolgte durch punktuelle sowie durch sequenzielle Blutentnahmen über 6-stündige Zeitfenster. Folgende Parameter wurden erfasst: AUC (Area Under the Curve), Basalkonzentration, Anzahl der Pulse und maximale Pulsamplitude. Ergebnisse: Dosisabhängigkeiten waren nicht feststellbar, was darauf hindeutet, dass die niedrigste Dosis bereits maximal wirksam war. Für die weitere Auswertung wurden die Tiere daher zu einer Gruppe zusammengefasst. Ein zunehmend stärker werdender Effekt der Downregulation zeigte sich von der 2. bis zur 26. Woche nach der Implantation, die Wirkdauer lag bei ca. 34 Wochen. Eine Stunde nach der Implantation kam es zu einem signifikanten Anstieg auf fast das Doppelte des Ausgangswerts. Danach blieb das LH-Niveau über weitere 8 Stunden erhöht. Schlussfolgerung: Wie beim Rüden führt Buserelin auch bei der Hündin zu einer Downregulation der LH-Sekretion, der eine initiale, über mehrere Stunden anhaltende erhöhte LH-Freisetzung vorausgeht. Diese muss im Zusammenhang mit den unerwünschten Wirkungen gesehen werden, die bei der Downregulation der Ovarfunktion der Hündin mittels Slow-Release-GnRH-Analoga auftreten. Klinische Relevanz: Die Unterbindung des initialen Anstiegs der LH-Konzentration ist Voraussetzung für eine erfolgreiche Anwendung von Slow-Release-GnRH-Analoga zur Downregulation der Sexualfunktion der Hündin.

Effizienz neurolinguistischer Teletherapie

Die dialogische Online-Telesprachtherapie bietet vor allem für den ländlichen Raum in Zukunft neue Chancen für eine bedarfsgerechte und wohnortnahe Versorgung der Patienten mit Sprach- und Sprechstörungen. Patient und Therapeut agieren in Echtzeit direkt über den Bildschirm miteinander, sodass dem Patienten aufwändige Wege in ein spezialisiertes sprachtherapeutisches Zentrum erspart werden können. Die Telesprachtherapie ermöglicht die Aufrechterhaltung einer sektorenübergreifenden Versorgungskette (supply chain) durch Überbrückung eventueller poststationärer Engpässe.

Grundlagen der Wirkungsweise und sich daraus ergebende klinische Anwendungen von Antigestagenen bei Hund und Katze

Bei Antigestagenen handelt es sich um Wirkstoffe, die kompetitiv zum körpereigenen Progesteron an den nukleären Progesteronrezeptor binden, ohne dass jedoch dadurch die nachfolgende Transkription eingeleitet wird. Damit ergibt sich die grundsätzliche Möglichkeit, durch Anwendung dieser Wirkstoffgruppe zu vorgegebenen Zeitpunkten gezielt die Progesteronwirkung aufzuheben. So kann durch Aufhebung der protektiven Wirkung von Progesteron beim Hund eine Nidationsverhütung, ein Graviditätsabbruch, aber auch die Einleitung einer Geburt erfolgen. Der progesteronbedingte Zervixverschluss lässt sich ebenfalls aufheben, wodurch auch im Fall einer geschlossenen Pyometra erstmals alternativ zur Ovariohysterektomie eine gut verträgliche konservative Therapie möglich ist. Diese für den Hund geltenden Beobachtungen können entsprechend auf die Katze übertragen werden. Bei dieser Tierart stellt die Behandlung der Fibroadenomatose mittels Antigestagen eine weitere neue therapeutische Option dar. Für die Veterinärmedizin steht seit 2004 das den antigestagenen Wirkstoff Aglepriston enthaltende Tierarzneimittel Alizin® zum Graviditätsabbruch bei der Hündin zur Verfügung. Eine darüber hinausgehende Anwendung lässt das Arzneimittelgesetz aufgrund der Möglichkeiten der Umwidmung zu. In einem solchen Fall ist tierärztlicherseits jedoch ein äußerst sorgfältiges und mit der entsprechenden Aufklärung verbundenes Vorgehen notwendig.

Samengewinnung, -konservierung und künstliche Besamung beim Hund

Die künstliche Besamung ist ein inzwischen auch beim Hund etabliertes Verfahren. Zum Einsatz kommen Frischsperma bzw. flüssig- und gefrierkonserviertes Sperma. Das Ejakulat wird durch manuelle Stimulation, bevorzugt in Anwesenheit einer läufigen Hündin, fraktioniert gewonnen, wobei zur Herstellung von flüssig- bzw. gefrierkonserviertem Sperma ausschließlich die spermienreiche Fraktion verwendet werden sollte. Die Verdünnung erfolgt üblicherweise mit einem Tris-Eidotter-Puffer mit einem Antibiotikazusatz bei flüssigkonserviertem Sperma, für die Herstellung von Tiefgefriersperma wird Glyzerin zugesetzt. Entscheidend für den Besamungserfolg ist die Wahl des Besamungszeitpunktes, insbesondere bei Verwendung von Tiefgefriersperma. Vaginalzytologie und Vaginoskopie sollten mit einer Progesteronbestimmung verbunden sein, um den für die Samenübertragung optimalen Bereich um 12 ng/ml Plasma zu definieren. Derzeit kommen vier Inseminationstechniken zur Anwendung: die tief intravaginale Besamung, die transzervikale-intrauterine Besamung mithilfe eines starren Katheters unter transabdominaler Fixation der Zervix, die transzervikale-intrauterine Besamung unter endoskopischer Kontrolle sowie die chirurgische intrauterine Besamung via Laparotomie/Laparoskopie. Bei der Verwendung von Tiefgefriersperma sollte grundsätzlich die intrauterine Samendeponierung angestrebt werden. Als Besamungsdosis werden, unabhängig von der Art des Inseminats, mindestens 150 × 106 vorwärtsbewegliche Spermien empfohlen. Unter optimalen Voraussetzungen können mit der künstlichen Besamung auch beim Einsatz von kryokonserviertem Sperma mit dem natürlichen Deckakt vergleichbare Trächtigkeitsraten und Wurfgrößen erzielt werden.

Prevalence of Stemmer's sign in the general population

Lymphoedema is a disease frequently diagnosed in vascular departments, its origin being primary or secondary after cellulitis or cancer treatment. The prevalence of lower extremity lymphoedema in the general population is largely unknown. The aim of this article is to describe the prevalence of Stemmer's sign as a diagnostic criterium for lymphoedema in an unselected adult German population. Methods: The population for this cross-sectional study was recruited from November 2000 through March 2002 from the general population of the city of Bonn and two surrounding rural communities. 3072 individuals (1145 rural and 1927 urban) could be enrolled in the study. The results of the clinical examination were categorized in four groups: grade 0 normal skin fold at the dorsum of the second toe, grade 1 skin fold enlarged measuring 0.5–1 cm, grade 2 the skin fold >1 cm and grade 3 >1 cm with severe induration or papillomatosis. Results: Among 3055 out of 3072 subjects information on all variables were available. In 15.9% of the population a positive Stemmer sign was found with a slightly higher overall prevalence in women. Most of this group presented as grade 1 Stemmer's sign (14.1%). The more severe grades 2 and 3 were present in 1.8 % of the study population with no clear difference between sexes. We observed a considerably higher prevalence of Stemmer's sign of all grades in the urban population. The prevalence of Stemmer's sign increased with age from 3.2% up to 35.9% in the 70–79 year old population. Prevalence of positive Stemmer's sign was also higher in higher C-stages of the CEAP classification (5.8% in C0 to 100% in C6). Conclusions: The prevalence of lymphoedema in the general population represented by grade 2–3 Stemmer's sign in 1.8% and grade 1 Stemmer's sign in 14% is high. Women have a slightly higher prevalence of positive Stemmer's sign than men. The prevalence of positive Stemmer's sign is associated with age and chronic venous insufficiency.