O-238 Critical requirement of intracellular zona pellucida proteins for mouse embryo survival

Study question

Are the intracellular deposits of zona pellucida (ZP) proteins relevant to embryonic development?

Summary answer

Contrary to longstanding views, ZPs are not only oocyte-specific proteins with extracellular tasks, but also have intracellular tasks that are essential for embryo survival.

What is known already

Mutation studies always defined the ZP functions as extracellular, namely: to encase oocytes in ovarian follicles, to ensure species-specific sperm binding, and to dampen shear stress on the embryo surface. Therefore, ZP mutations cause primary infertility due to empty follicles, polyspermic fertilization or harmful contact between embryo and oviductal epithelium. However, when these limitations were obviated in mice by monospermic fertilization in vitro and blastocyst transfer to uterus, the concepti of ZP2-null and ZP3-null oocytes were still unviable (PMID 11245577). This suggests that the tasks of ZPs don’t end in the extracellular space as previously assumed.

Study design, size, duration

After monospermic fertilization, wild-type mouse oocytes were depleted of intracellular ZP proteins using the ‘Trim-away’ method (PMID 29153837). ZP1-3 were targeted by prevalidated antibodies (producing a dominant band in Western blot) and committed for proteasomal degradation by the ubiquitine ligase Trim21. Antibodies were either folded or denatured (heat-inactivated), thereby allowing for efficient or abolished depletion, respectively (negative control). The two groups were examined for development and efficiency of ‘Trim-away’ at degrading the ZPs.

Participants/materials, setting, methods

Mature B6C3F1 female mice were stimulated with gonadotropins (eCG, hCG) and mated to CD1 stud males to collect fertilized superovulated oocytes. These were microinjected with a cocktail of mCherry-Trim21 mRNA and anti-ZP antibody, followed by culture in KSOM(aa) medium for 96 hours. Successful depletion of ZP proteins was measured by mCherry fluorescence, ZP Western blotting and mass spectrometry. Developmental rates were compared between the groups of the folded vs. denatured antibodies.

Main results and the role of chance

Fertilized oocytes depleted of ZP3 did not cleave and remained arrested at 1-cell stage (0 blastocysts / 300 oocytes; 7 replicates). Oocytes depleted of ZP2 cleaved once or twice, and remained arrested at 2- or 4-cell stage (0 blastocysts/ 100 oocytes; 3 replicates). These failures stood in contrast to the blastocyst progression of oocytes depleted of ZP1 (42 blastocysts / 100 oocytes; 3 replicates) and negative controls injected with either of the denatured antibodies (>50% blastocysts) (p < 0.01; chi test). Molecular efficacy of ‘Trim-away’ was manifest from the decline of mCherry fluorescence, and from the reduction of the ZP signal intensity in Western blot and mass spectrometry; whereas the negative controls remained bright-fluorescent and retained the dominant band in Western blot. Inspection of publicly available datasets from two-hybrid and affinity capture screens reveals that ZP3 has more than 20 interaction partners in cell lines. Collectively, this information supports that ZP proteins are required for developmental competence not only outside but also inside of oocytes, where the ZPs might interact with more proteins than just ZP1, ZP2 and ZP3. Our study provides novel insight into the pathogenic mechanism of ZP gene mutations, adding a novel intracellular route to the longstanding extracellular roles. 

Limitations, reasons for caution

Although there is sufficient evidence for expanding on the tasks of ZPs in mice, human oocytes contain ZP4 in addition to ZP1-3. While the novel tasks in mice rely on stable protein deposits that persist from oocyte to blastocyst, it is not known if the human counterparts persist that long.

Wider implications of the findings

ZPs may qualify as ‘moonlighting proteins’ that enrich - but at the same time also complicate - the determination of primary infertility phenotype from genotype.

Trial registration number

not applicable

O-169 Conventional ovarian stimulation with gonadotropins depletes the developmental proteome of mouse oocytes, reducing their size and compromising their fetal yield

Study question

Does conventional ovarian stimulation with gonadotropins alter the molecular composition, size, and developmental fitness of superovulated mouse oocytes?

Summary answer

Ovarian stimulation perturbs 31% of developmental proteome vs. 2% of transcriptome, yielding smaller oocytes that form blastocysts with less primitive endoderm and diminished fetal yield.

What is known already

Prior mouse studies aimed to assess the impact of superovulation on oocyte and embryo quality provided variable results. Aberrations were observed in some studies but not in others, and were associated with a variable time spent in the oviduct until retrieval for in vitro culture. Although the natural ovarian cycle lasts 4 days in mice, the conventional stimulation protocol time spans 2 days. No genome-wide studies have been devoted yet to the global gene expression of superovulated mouse oocytes and derivative embryos, to determine if gene products accumulate to the same extent as in natural cycles.

Study design, size, duration

Approx. 1100 female mice were injected, half with serial equine and human chorionic gonadotropin, eCG and hCG, to induce superovulation; the other half were injected with saline as control. Both groups were mated to vasectomized or fertile males to obtain, respectively, metaphase II and fertilized oocytes. These were removed from the oviducts, and followed up in vitro to blastocyst, or in vivo to term after surgical transfer to naturally cycling females.

Participants/materials, setting, methods

B6C3F1 oocytes (n= ∼16000) from superovulation (10 I.U. eCG+hCG) or natural ovulation were measured for diameter, and upon fertilization, they were cultured in KSOM(aa) to collect preimplantation stages for analyses (mass spectrometry; RNA sequencing; immunofluorescence for counting of trophectoderm, epiblast, and primitive endoderm cells). Embryos at the 4-cell stage were transplanted to naturally cycling females (8/female, 45 recipients). Results were compared between natural ovulation and superovulation with 48h (conventional) or 72h interval of eCG-hCG stimulation.

Main results and the role of chance

Preimplantation embryos of superovulated oocytes were affected in 31% of the proteins (893 / 2855) vs. 2% of the transcripts (482 / 21784), compared to natural counterparts (adj.P<0.05, Wilcoxon test). Gene set enrichment analysis of the perturbed proteome returned the top-terms ‘thin zona pellucida’ (ZP1, ZP2, ZP3) and ‘abnormal inner cell mass apoptosis’ (DAB2, STAT3). Microscope measurements verified a thinner zona pellucida (p = 0.077, Wilcoxon test) along with a smaller diameter (p < 0.0001, Wilcoxon test) of superovulated oocytes, which gave rise to blastocysts deficient in primitive endoderm (p < 0.013, Fisher’s exact test). Since 529 of the 893 differently expressed proteins were depleted, we considered that ovarian stimulation provided insufficient time for protein accumulation. Increasing the eCG-hCG interval from 48 h (conventional) to 72 h restored oocytes’ diameters, and improved their fetal output from 25% to 59%, compared to 54% of natural ovulation (15 embryo transfers per group). Conversely, oocytes lost part of their developmental potential to the micromanipulation-assisted reduction of their volume. This study provides evidence of an additional novel effect of exposure to gonadotropins on mouse oocyte quality, whose mechanism is mediated not by the stimulated genital tract, but by the time-dependent accumulation of proteins in oocytes.

Limitations, reasons for caution

This is an animal model study based on one mouse strain. Ovarian stimulation protocols differ between mice and humans. There can be yet other, more subtle or long-term differences between superovulated and naturally ovulated oocytes, than those described here. Proteome and transcriptome analysis cover much, but not everything.

Wider implications of the findings

There is a trade-off between oocyte quantity and quality in mice subjected to superovulation. Cytological and molecular deficits define a ‘small oocyte syndrome’. Problematic is not so much the gonadotropin treatment, rather its timing. An evidence-based protocol for superovulation may be different from that used currently in mice.

Trial registration number

Not applicable

A Flying Platform to Investigate Neuronal Correlates of Navigation in the Honey Bee (Apis mellifera)

Navigating animals combine multiple perceptual faculties, learn during exploration, retrieve multi-facetted memory contents, and exhibit goal-directedness as an expression of their current needs and motivations. Navigation in insects has been linked to a variety of underlying strategies such as path integration, view familiarity, visual beaconing, and goal-directed orientation with respect to previously learned ground structures. Most works, however, study navigation either from a field perspective, analyzing purely behavioral observations, or combine computational models with neurophysiological evidence obtained from lab experiments. The honey bee (Apis mellifera) has long been a popular model in the search for neural correlates of complex behaviors and exhibits extraordinary navigational capabilities. However, the neural basis for bee navigation has not yet been explored under natural conditions. Here, we propose a novel methodology to record from the brain of a copter-mounted honey bee. This way, the animal experiences natural multimodal sensory inputs in a natural environment that is familiar to her. We have developed a miniaturized electrophysiology recording system which is able to record spikes in the presence of time-varying electric noise from the copter's motors and rotors, and devised an experimental procedure to record from mushroom body extrinsic neurons (MBENs). We analyze the resulting electrophysiological data combined with a reconstruction of the animal's visual perception and find that the neural activity of MBENs is linked to sharp turns, possibly related to the relative motion of visual features. This method is a significant technological step toward recording brain activity of navigating honey bees under natural conditions. By providing all system specifications in an online repository, we hope to close a methodological gap and stimulate further research informing future computational models of insect navigation.

Basal cell carcinoma risk and solar UV exposure in occupationally relevant anatomic sites: do histological subtype, tumor localization and Fitzpatrick phototype play a role? A population-based case-control study

Background

A two-fold risk increase to develop basal cell carcinoma was seen in outdoor workers exposed to high solar UV radiation compared to controls. However, there is an ongoing discussion whether histopathological subtype, tumor localization and Fitzpatrick phototype may influence the risk estimates.

Objectives

To evaluate the influence of histological subtype, tumor localization and Fitzpatrick phototype on the risk to develop basal cell carcinoma in highly UV-exposed cases and controls compared to those with moderate or low solar UV exposure.

Methods

Six hundred forty-three participants suffering from incident basal cell carcinoma in commonly sun-exposed anatomic sites (capillitium, face, lip, neck, dorsum of the hands, forearms outside, décolleté) of a population-based, case-control, multicenter study performed from 2013 to 2015 in Germany were matched to controls without skin cancer. Multivariate logistic regression analysis was conducted stratified for histological subtype, phototype 1/2 and 3/4. Dose-response curves adjusted for age, age², sex, phototype and non-occupational UV exposure were calculated.

Results

Participants with high versus no (OR 2.08; 95% CI 1.24–3.50; p = 0.006) or versus moderate (OR 2.05; 95% CI 1.15–3.65; p = 0.015) occupational UV exposure showed a more than two-fold significantly increased risk to develop BCC in commonly UV-exposed body sites. Multivariate regression analysis did not show an influence of phototype or histological subtype on risk estimates. The restriction of the analysis to BCC cases in commonly sun-exposed body sites did not influence the risk estimates. The occupational UV dosage leading to a 2-fold increased basal cell carcinoma risk was 6126 standard erythema doses.

Conclusion

The risk to develop basal cell carcinoma in highly occupationally UV-exposed skin was doubled consistently, independent of histological subtype, tumor localization and Fitzpatrick phototype.

Impact of physiologically relevant temperatures on dermal absorption of active substances - an ex-vivo study in human skin

Skin temperature plays a certain role in the dermal absorption of substances, but the extent and mechanisms of skin temperatures-induced modulation in ranges caused by physiological thermoregulation or environmental conditions are largely unknown. The influence of dermal temperature on the absorption of the model lipophilic compound (anisole) and the model hydrophilic compounds (1,4-dioxane, ethanol) through human skin was investigated at three dermal temperatures (25, 32 and 39 °C) in an ex-vivo diffusion cell model. The substances were applied to the skin and transdermal penetration was monitored. All substances showed temperature dependent variations in their penetration behavior (3 h: 25-39 °C: 202-275% increase in cumulative, transdermally penetrated amounts). The relative differences in absorption in relation to temperature were greatest within 45 min after exposure (25-39 °C: 347-653% rise in cumulated penetration), although absolute amounts absorbed were small (45 min vs. 3 h: 4.5-14.5%). Regardless of blood circulation, skin temperature significantly influences the amount and kinetics of dermal absorption. Substance-dependent, temperature-related changes of the lipid layer order or the porous pathway may facilitate penetration. The early-stage modulation of transdermal penetration indicates transappendageal absorption, which may be relevant for short-term exposures. For both, toxicological evaluation and perfusion cell studies, it is important to consider the thermal influence on absorption or to perform the latter at a standardized temperature (32±1 °C).

Evaluation of urinary selenium as a biomarker of human occupational exposure to elemental and inorganic selenium

PURPOSE

Selenium (Se) is an essential trace element, which however, exhibits a narrow safe range of intake. Selenium also occurs at several workplaces, which results in an inhalative selenium exposure of the employees. Thus, an efficient exposure assessment strategy is demanded. The most established parameter, selenium in plasma, mostly consists of protein-bound selenium. This study aimed to investigate urinary total selenium (Se-U) as an additional biomarker of recent human occupational exposure to elemental and inorganic selenium.

METHODS

Pre- and post-shift urine samples from employees with exposure to selenium-containing dust were analyzed to total selenium and compared with Se levels in urine samples from controls without occupational exposure to selenium as well as correlated with the recent ambient Se exposure by personal air monitoring.

RESULTS

Se-U in post-shift samples was considerably increased compared to the levels in pre-shift samples as well as to the controls. However, Se-U in pre-shift urine was elevated compared to the Se-U in controls too. Se-U in post-shift urine and even better the shift increment in Se-U correlated with the air exposure of the present shift. A rough estimation by Se-U shift increment and external exposure accounted for an inhalative resorption rate of about 1%.

CONCLUSION

Our data indicate that Se-U can display the exposure. Pre-shift Se-U levels may be based on previous exposure and indicate a slow urinary elimination kinetics. The results hint for a rather low resorption rate of selenium and inorganic selenium compounds via the lung.

Sickness absence among peer-supported drivers after occupational trauma

Background

Psychological first aid is a common approach for providing support after potentially traumatic events (PTEs). In Germany, a peer support model is recommended by the German Statutory Accident Insurance (DGUV) to reduce sickness absence after occupational accidents, especially in public transportation. However, data on the effectiveness of peer support are very sparse.

Aims

To analyse whether peer support has an impact on sickness absence after work-related traumatic events in public transportation.

Methods

An analysis was conducted in two German public transportation corporations. Due to ethical requirements, we used a historical cohort study comparing peer support by colleagues (VAG-1), peer support at supervisor level (VGF) and a non-intervention group (VAG-0). The study period was from March 2003 to December 2012. We used a negative binominal regression model to estimate the relative risk associated with the interventions and potential confounders.

Results

A total of 259 incident PTEs in employees were observed. A regression analysis identified the severity of PTE (severe and fatal events), VGF and age as significant factors in predicting duration of post-event sickness absence. In a stratified analysis, the mode of peer support (VGF) and age predicted sickness absence for less severe PTEs but this was not significant for severe PTEs.

Conclusions

Severe and fatal PTEs had the strongest impact on sickness absence after PTEs. For less severe PTE, peer support provided by colleagues may be superior to supervisor support.

Fluid status telemedicine alerts for heart failure: a randomized controlled trial

AIMS

Hospital admissions are frequently preceded by increased pulmonary congestion in heart failure (HF) patients. This study evaluated whether early automated fluid status alert notification via telemedicine improves outcome in HF patients.

METHODS AND RESULTS

Patients recently implanted with an implantable cardioverter defibrillator (ICD) with or without cardiac resynchronization therapy were eligible if one of three conditions was met: prior HF hospitalization, recent diuretic treatment, or recent brain natriuretic peptide increase. Eligible patients were randomized (1:1) to have fluid status alerts automatically transmitted as inaudible text message alerts to the responsible physician or to receive standard care (no alerts). In the intervention arm, following a telemedicine alert, a protocol-specified algorithm with remote review of device data and telephone contact was prescribed to assess symptoms and initiate treatment. The primary endpoint was a composite of all-cause death and cardiovascular hospitalization. We followed 1002 patients for an average of 1.9 years. The primary endpoint occurred in 227 patients (45.0%) in the intervention arm and 239 patients (48.1%) in the control arm [hazard ratio, HR, 0.87; 95% confidence interval (CI), 0.72-1.04; P = 0.13]. There were 59 (11.7%) deaths in the intervention arm and 63 (12.7%) in the control arm (HR, 0.89; 95% CI, 0.62-1.28; P = 0.52). Twenty-four per cent of alerts were not transmitted and 30% were followed by a medical intervention.

CONCLUSION

Among ICD patients with advanced HF, fluid status telemedicine alerts did not significantly improve outcomes. Adherence to treatment protocols by physicians and patients might be challenge for further developments in the telemedicine field.

[Psychotrauma after occupational accidents in public transportation. A pilot study to support concepts, influencing factors and occupational health-care]

BACKGROUND AND AIM OF THE STUDY

Accidents, assaults and suicides occur quite frequently in public transportation. As a result of such extreme events at work, drivers are particularly prone to psychotrauma (PT). Therefore accident insurers stipulate support from the accident site to workplace reintegration with the inclusion of occupational medicine. The present study investigates the incidence, factors influencing psychological trauma as well as the occupational health-care after critical incidents.

METHODS

In a Bavarian public transportation corporation 59 employees were evaluated according to ICD-10 for trauma-related disorders, using full collection after application of a specific mental first aid programme and a subsequent occupational health examination.

RESULTS

The incidence of PT was 44.1%, with 8.5% showing a post-traumatic stress disorder (PTSD) as consequence of the accident. As significant influencing factors the nature of the accident, the severity of third party injury, and own physical injuries were identified. The occupational medical care depended on the severity of the disease. PT led to the need for rehabilitation. Sick leave was most pronounced in drivers with PTSD.

CONCLUSION

The study group showed high levels of emotional strain within the first month. With respect to occupational health-care, particular attention should be paid to drivers after serious accidents or those who sustained own injuries. As foundation for evidence based health-care measures after PT in transport must be scientifically evaluated and the identified risk factors must be well-founded as well.

Occlusive gloves and skin conditions: is there a problem? Results of a cross-sectional study in a semiconductor company

BACKGROUND

Although there is poor scientific evidence that working with occlusive gloves is as damaging as wet work, prolonged glove occlusion is considered to be a risk factor for developing hand eczema similar to wet work.

OBJECTIVES

To assess the effects of wearing occlusive gloves during the whole working day, without exposure to any additional hazardous substances, on skin condition and skin barrier function.

METHODS

We investigated 323 employees of a semiconductor production company in Germany: 177 clean-room workers wearing occlusive gloves during the whole shift (exposed group) and 146 employees working in administration (control group). A standardized interview was performed, the skin condition of both hands was studied using the quantitative skin score HEROS, and transepidermal water loss (TEWL) and stratum corneum hydration were measured.

RESULTS

There was no significant difference in skin condition between the two subgroups. Values for TEWL and corneometry were significantly higher in exposed participants (P < 0·05). However, the TEWL values were similar to control values if participants took off the occlusive gloves at least 30 min before the measurement. Hence, the effect of occlusion on skin barrier function seems to be transient.

CONCLUSIONS

Prolonged wearing of occlusive gloves with clean hands and without exposure to additional hazardous substances does not seem to affect the skin negatively.

[Workplace Health Promotion in Small, Medium-Sized and Large Enterprises of the Health-Care Sector - Frequency, Reasons for the Company Management to Take Action and Barriers to Implementation]

PURPOSE

The aim of this study was to gain insight into worksite health promotion in small and medium-sized companies compared to large concerns in Middle Franconia. Action in worksite health promotion, obstacles and demand for networks for workplace health promotion were determined.

METHOD

A standardised telephone interview served for collecting data for this cross-sectional study. The interviewee was always the manager or their proxy. 106 companies were contacted. The results of this study were analysed via qualitative and quantitative methods in SPSS(®) 20.

RESULTS

It was possible to reach and interview 80 companies, a return rate of 75.5%. More than half the companies (68.8%) implemented at least one activity for worksite health promotion, especially ergonomic measures and measures to promote physical activity. Taking the size of the company into consideration when analysing the results, previous study results are confirmed. With an increasing size of the company, the relative frequency of measures for workplace health promotion rises. The motivation for worksite health promotion ranges from keeping the employees healthy (38.2%) to worksite health promotion as part of the business culture (9.1%). 81.1% of the companies consider their activity in worksite health promotion to be successful. Furthermore, 80.0% of the firms that implemented worksite health promotion were supported by a partner like a health insurance (43.2%). Those companies that did not implement any activities for worksite health promotion, state as a prime reason that they did not think about it as yet (44.0%). Besides, 44.0% of the companies without any worksite health promotion would like to implement measures. 65.5% of the companies that already took action in worksite health promotion and 56.0% of the companies that did not would like to cooperate with other firms in a network for workplace health promotion. Mutual exchange is the most important factor for them.

CONCLUSION

The results of this study show that almost half of the companies that did not implement measures for worksite health promotion as yet would like to take action in this regard. For a bigger establishment of worksite health promotion, networks are predestinated and are best accompanied and supported by external professionals like health insurances, mutual indemnity associations or universities.

[Memorandum 'Development of health services research in Bavaria from the perspective of the Bavarian State Working Group 'Health Services Research (LAGeV)': status quo - potential - strategies']

The aim of the memorandum on the development of health services research (HSR) in Bavaria is to operationalise the global objectives of the State Working Group "Health Services Research" (LAGeV) and to collectively define future topics, specific implementation steps, methods as well as ways of working for the future course of the LAGeV. The LAGeV is an expert committee that integrates and links the competencies of different actors from science, politics and health care regarding HSR and facilitates their cooperation. The memorandum is based on an explorative survey among the LAGeV members, which identified the status quo of health services research in Bavaria, potential for development, important constraints, promoting factors, specific recommendations as well as future topics for the further development of HSR in Bavaria. From the perspective of the LAGeV members, the 12 most important future topics are: 1) Interface and networking research, 2) Innovative health care concepts, 3) Health care for multimorbid patients, 4)Health care for chronically ill patients, 5) Evaluation of innovations, processes and technologies, 6) Patient orientation and user focus, 7) Social and regional inequalities in health care, 8) Health care for mentally ill patients, 9) Indicators of health care quality, 10) Regional needs planning, 11) Practical effectiveness of HSR and 12) Scientific use of routine data. Potential for development of HSR in Bavaria lies a) in the promotion of networking and sustainable structures, b) the establishment of an HSR information platform that bundles information and results in regard to current topics and aims to facilitate cooperation as well as c) in the initiation of measures and projects. The latter ought to pinpoint health care challenges and make recommendations regarding the improvement of health care and its quality. The cooperation and networking structures that were established with the LAGeV should be continuously expanded and be used to work on priority topics in order to achieve the global objectives of the LAGeV.

[Evidence-based health services research--a short review and implications]

BACKGROUND

Health services research aims to generate knowledge about care processes of people with illnesses who access health-care services. In addition, the consequences of those processes in the care routine concerning the involved persons and the health system are analyzed. CONCEPT OF THE THEORETICAL WORK: In the first part of the manuscript, an overview concerning the current definitions and subsumptions of the concept of health services research is given. The second part of the manuscript focuses on demonstrating how evidence-based health services research can be used to enable optimization of the care system. The concept is called the "circle of care optimization". In the first step the current care situation concerning its deficits and their reasons is analyzed. In the second step a relevant care goal is defined. In the third step an improvement of an existing care process is developed to achieve the defined care goal. In the fourth step, a comparative empirical study with a high-quality study design is carried out, to assess whether the improved care process is superior to the current care as usual. A health economic evaluation will be performed if applicable. If the results show no or only small advantages, the "circle" starts again with step 3. However, if the results show a significant effect in favour of the new care process and are relevant for the delivery of care and efficient in the context of health economics, a fifth step will be performed which involves developing and testing strategies for implementation. Where relevant, the consequences of implementation are investigated in a sixth step. A "best-practice" practical example is demonstrated to illustrate the "circle of care optimization".

CONCLUSIONS

conclusions are derived by illustrating future challenges for health services research.

European multidisciplinary consensus statement on the use and monitoring of metal-on-metal bearings for total hip replacement and hip resurfacing

INTRODUCTION

There is an ongoing debate about the optimal use of metal-on-metal (MoM) bearings in total hip replacement, since there are uncertainties about local and systemic adverse effects due to wear and corrosion of these bearings. Despite various national recommendations, efforts to achieve international harmonization of specific evidence-based recommendations for best practice are still lacking.

HYPOTHESIS

An international consensus study group should be able to develop recommendations on the use and monitoring of MoM bearings, preferably at the European level, through a multidisciplinary approach, by integrating the perspectives of various stakeholders.

MATERIALS AND METHODS

Twenty-one experts representing three stakeholder groups and eight countries participated in this European consensus study, which consisted of a consensus meeting, subsequent structured discussion, and consensus voting.

RESULTS

The current statement defines first of all benefits, local and systemic risks, as well as uncertain issues related to MoM bearings. Safety assessment after implantation of MoM comprises all patients. A closer follow-up is recommended for large head MoM (≥36mm) and resurfacing. In these implants basic follow-up should consist of x-rays and metal ion measurement of cobalt in whole blood, performed with GF-AAS or ICP-MS. Clinical and/or radiographic abnormality as well as elevated ion levels needs additional imaging (ultrasound, CT-scan and/or MARS-MRI). Cobalt values less than 2 μg/L are probably devoid of clinical concern, the threshold value for clinical concern is expected to be within the range of 2-7 μg/L.

DISCUSSION

This is the first multinational, interdisciplinary, and multiprofessional approach for developing a recommendation for the use and monitoring of MoM bearings in total hip replacement. The current recommendations are in partial agreement with previous statements regarding the extent of follow-up and imaging techniques. They however differ from previous communications regarding measurement of metal ions and especially the investigated medium, technique, and eventual threshold levels.

LEVEL OF EVIDENCE

Level V, expert opinion/agreement conference.

[Biomonitoring for occupational medicine]

Biomonitoring is an essential occupational-medical instrument for assessing the exposure of chemical agents of workers. It is an integral part of preventive medical examinations as far as established analytical procedures and values for evaluating biomonitoring results are available. The DFG Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has published values for evaluating biomonitoring results. Those values are health related values such as the Biological Tolerance Value (BAT) and descriptive values such as the "Biologischer Arbeitsstoff-Referenzwert" (BAR) and Exposure Equivalents for Cancerous Substances (EKA), respectively. Moreover the combination of acceptance values and tolerance values derived by the Committee on Hazardous Substances (AGS) from exposure-risk-relations with the EKA allow the deduction of risk-related values too. The European Biological Limit Value (BLV) and the Biological Guidance Value are also important in the countries of the European Union. The results of a biological monitoring represent person-related data and therefore are subject to the rules on professional confidentiality that apply to physicians.

Erythropoietin preserves the endothelial differentiation capacity of cardiac progenitor cells and reduces heart failure during anticancer therapies

Anticancer therapies, such as targeting of STAT3 or the use of anthracyclins (doxorubicin), can induce cardiomyopathy. In mice prone to developing heart failure as a result of reduced cardiac STAT3 expression (cardiomyocyte-restricted deficiency of STAT3) or treatment with doxorubicin, we observed impaired endothelial differentiation capacity of Sca-1(+) cardiac progenitor cells (CPCs) in conjunction with attenuated CCL2/CCR2 activation. Mice in both models also displayed reduced erythropoietin (EPO) levels in the cardiac microenvironment. EPO binds to CPCs and seems to be responsible for maintaining an active CCL2/CCR2 system. Supplementation with the EPO derivative CERA in a hematocrit-inactive low dose was sufficient to upregulate CCL2, restore endothelial differentiation of CPCs, and preserve the cardiac microvasculature and cardiac function in both mouse models. Thus, low-dose EPO treatment could potentially be exploited as a therapeutic strategy to reduce the risk of heart failure in certain treatment regimens.

Five-year results of the Multicenter Randomized Controlled Open-Label Study of the CYPHER Sirolimus-Eluting Stent in the Treatment of Diabetic Patients with De Novo Native Coronary Artery Lesions (SCORPIUS) study: a German multicenter investigation on the effectiveness of sirolimus-eluting stents in diabetic patients

BACKGROUND

Because a delayed arterial healing response after drug-eluting stent implantation has raised concerns about safety in diabetic patients, long-term effects of treatment with sirolimus-eluting stent (SES), as compared with bare-metal stent (BMS), have to be established. The aim of the 5-year follow-up of the randomized, controlled, open-label multicenter SCORPIUS study was to assess long-term safety and efficacy of the CYPHER (Cordis, Johnson & Johnson, Bridgewater, NJ) SES in percutaneous coronary intervention of diabetic patients.

METHODS

A total of 190 patients with type 2 diabetes mellitus were randomized to receive either a SES (n = 95) or a BMS (n = 95). Dual-antiplatelet therapy (aspirin plus clopidogrel) was prescribed for at least 6 months. Clinical follow-up data were scheduled at 1, 8, and 12 months and 5 years.

RESULTS

Treatment with SES resulted in a 16% decrease in the rate of major adverse cardiac events (36% vs 52%; hazard ratio 0.6, 95% CI 0.4-0.9; P = .02). This reduction in major adverse cardiac events with SES at 5 years was mostly attributable to a lower number of repeat target lesion revascularization (13% vs 29%; hazard ratio 0.4, 95% CI 0.2-0.7; P = .003). No differences between groups were observed for safety end points (all-cause mortality 21% vs 21%, cardiac death 15% vs 13%, repeat myocardial infarction 8% vs 9%, and stent thrombosis 5% vs 6%) at 5 years.

CONCLUSIONS

The 5-year follow-up of the SCORPIUS trial demonstrates the long-term antirestenotic efficacy of SES in diabetic patients with significantly reduced target lesion revascularization and comparable rates of mortality, myocardial infarction, and stent thrombosis compared with BMS.

Extrinsic Notch ligand Delta-like 1 regulates tip cell selection and vascular branching morphogenesis

RATIONALE

In developing blood vessels, single endothelial cells (ECs) specialize into tip cells that sense vascular endothelial growth factor (VEGF) and contribute to vessel sprouting and branch formation. Tip cell differentiation is inhibited through lateral Notch signaling between ECs, which is controlled by Notch ligands expressed in vessel sprouts. The contribution of the Notch ligand Delta-like (Dll) 1 herein is unknown.

OBJECTIVE

To investigate the role of Dll1 in vascular morphogenesis and tip cell formation in the mouse retina.

METHODS AND RESULTS

Mice with heterozygous deletion of Dll1 had fewer tip cells during angiogenic sprouting of the superficial vascular plexus but also showed impaired vessel branching into deeper retinal layers and impaired deep plexus angiogenesis. Interestingly, the formation of vertical branches was also guided by filopodia-extending ECs located at the tip of branches, consistent with tip cells, which emerged from established vessels to form a secondary plexus within the deeper neuronal cell layers. During both phases of vascular patterning, Dll1 was not expressed in ECs but in the superficial neuronal layer in close contact with expanding vessels, where Dll1 expression coincided with tip cell formation in a spatiotemporal manner. In vitro, culture of ECs on DLL1 induced essential tip cell genes, including Dll4, VEGF receptor 3, and ephrin-B2, and stimulated VEGF responsiveness and vascular network formation.

CONCLUSIONS

Dll1 acts as an extrinsic cue involved in tip cell selection, which directs vessel sprouting and branch formation.

[Which occupational groups in a hospital are particularly stressed?]

BACKGROUND AND OBJECTIVE

Increasing workload in health professionals and resulting health consequences have frequently been reported. We analysed the results from an employee attitude survey within a network of workplace health promotion and compared three occupational groups of a university hospital with two samples of employees of other industries.

METHOD

The survey was conducted in the years 2005, 2006 and 2007 using a standardized method, addressing 1748 employees of six companies. In order to compare specific occupational groups, both within the hospital and amongst different companies, five occupational groups were selected (medical profession, nursing service and administration of the hospital, academics of another company and employees of a financial service provider).

RESULTS

Some results were specific for an occupational group, such as lower back pain and skin diseases in nurses and exhaustion in clinicians. Regarding several items the responses of employees of the hospital's administration were similar to that of the medical professionals and differed significantly from the responses of administrative and related employees in other companies. Employees of all occupational groups of the hospital were often frustrated and felt their work was not appreciated. Frequent demands included improved work atmosphere, better appreciation of work and better information regarding innovations.

CONCLUSIONS

The analysis of standardized survey results specific for companies and occupational groups is an appropriate way to identify targets of health promotion. Constant over three surveys, again a high burden of stress was found in health care workers even affecting the administrative staff, regarding several work-related stress factors. According to our results activities to improve the working conditions in hospitals are urgently needed.

Fluid status monitoring with a wireless network to reduce cardiovascular-related hospitalizations and mortality in heart failure: rationale and design of the OptiLink HF Study (Optimization of Heart Failure Management using OptiVol Fluid Status Monitoring and CareLink)

Aims

The Optimization of Heart Failure Management using OptiVol Fluid Status Monitoring and CareLink (OptiLink HF) study is designed to investigate whether OptiVol fluid status monitoring with an automatically generated wireless CareAlert notification via the CareLink Network can reduce all-cause death and cardiovascular hospitalizations in an HF population, compared with standard clinical assessment.

Methods

Patients with newly implanted or replacement cardioverter-defibrillator devices with or without cardiac resynchronization therapy, who have chronic HF in New York Heart Association class II or III and a left ventricular ejection fraction ≤35% will be eligible to participate. Following device implantation, patients are randomized to either OptiVol fluid status monitoring through CareAlert notification or regular care (OptiLink ‘on' vs. ‘off'). The primary endpoint is a composite of all-cause death or cardiovascular hospitalization. It is estimated that 1000 patients will be required to demonstrate superiority of the intervention group to reduce the primary outcome by 30% with 80% power.

Conclusion

The OptiLink HF study is designed to investigate whether early detection of congestion reduces mortality and cardiovascular hospitalization in patients with chronic HF. The study is expected to close recruitment in September 2012 and to report first results in May 2014.

ClinicalTrials.gov Identifier: NCT00769457

Exercise training improves in vivo endothelial repair capacity of early endothelial progenitor cells in subjects with metabolic syndrome

BACKGROUND

Endothelial dysfunction and injury are considered to contribute considerably to the development and progression of atherosclerosis. It has been suggested that intense exercise training can increase the number and angiogenic properties of early endothelial progenitor cells (EPCs). However, whether exercise training stimulates the capacity of early EPCs to promote repair of endothelial damage and potential underlying mechanisms remain to be determined. The present study was designed to evaluate the effects of moderate exercise training on in vivo endothelial repair capacity of early EPCs, and their nitric oxide and superoxide production as characterized by electron spin resonance spectroscopy analysis in subjects with metabolic syndrome.

METHODS AND RESULTS

Twenty-four subjects with metabolic syndrome were randomized to an 8 weeks exercise training or a control group. Superoxide production and nitric oxide (NO) availability of early EPCs were characterized by using electron spin resonance (ESR) spectroscopy analysis. In vivo endothelial repair capacity of EPCs was examined by transplantation into nude mice with defined carotid endothelial injury. Endothelium-dependent, flow-mediated vasodilation was analysed using high-resolution ultrasound. Importantly, exercise training resulted in a substantially improved in vivo endothelial repair capacity of early EPCs (24.0 vs 12.7%; p < 0.05) and improved endothelium-dependent vasodilation. Nitric oxide production of EPCs was substantially increased after exercise training, but not in the control group. Moreover, exercise training reduced superoxide production of EPCs, which was not observed in the control group.

CONCLUSIONS

The present study suggests for the first time that moderate exercise training increases nitric oxide production of early endothelial progenitor cells and reduces their superoxide production. Importantly, this is associated with a marked beneficial effect on the in vivo endothelial repair capacity of early EPCs in subjects with metabolic syndrome.

Conditional transgenic expression of fibroblast growth factor 9 in the adult mouse heart reduces heart failure mortality after myocardial infarction

BACKGROUND

Fibroblast growth factor 9 (FGF9) is secreted from bone marrow cells, which have been shown to improve systolic function after myocardial infarction (MI) in a clinical trial. FGF9 promotes cardiac vascularization during embryonic development but is only weakly expressed in the adult heart.

METHODS AND RESULTS

We used a tetracycline-responsive binary transgene system based on the α-myosin heavy chain promoter to test whether conditional expression of FGF9 in the adult myocardium supports adaptation after MI. In sham-operated mice, transgenic FGF9 stimulated left ventricular hypertrophy with microvessel expansion and preserved systolic and diastolic function. After coronary artery ligation, transgenic FGF9 enhanced hypertrophy of the noninfarcted left ventricular myocardium with increased microvessel density, reduced interstitial fibrosis, attenuated fetal gene expression, and improved systolic function. Heart failure mortality after MI was markedly reduced by transgenic FGF9, whereas rupture rates were not affected. Adenoviral FGF9 gene transfer after MI similarly promoted left ventricular hypertrophy with improved systolic function and reduced heart failure mortality. Mechanistically, FGF9 stimulated proliferation and network formation of endothelial cells but induced no direct hypertrophic effects in neonatal or adult rat cardiomyocytes in vitro. FGF9-stimulated endothelial cell supernatants, however, induced cardiomyocyte hypertrophy via paracrine release of bone morphogenetic protein 6. In accord with this observation, expression of bone morphogenetic protein 6 and phosphorylation of its downstream targets SMAD1/5 were increased in the myocardium of FGF9 transgenic mice.

CONCLUSIONS

Conditional expression of FGF9 promotes myocardial vascularization and hypertrophy with enhanced systolic function and reduced heart failure mortality after MI. These observations suggest a previously unrecognized therapeutic potential for FGF9 after MI.

Intracoronary bone marrow cell transfer after myocardial infarction: 5-year follow-up from the randomized-controlled BOOST trial

AIMS

We assessed whether a single intracoronary infusion of autologous bone marrow cells (BMCs) can have a sustained impact on left ventricular ejection fraction (LVEF) in patients after ST-elevation myocardial infarction (STEMI). In the BOne marrOw transfer to enhance ST-elevation infarct regeneration (BOOST) trial, 60 patients with STEMI and successful percutaneous coronary intervention were randomized to a control and a cell therapy group. As previously reported, BMC transfer led to an improvement of LVEF by 6.0% at 6 months (P = 0.003) and 2.8% at 18 months (P = 0.27).

METHODS AND RESULTS

Left ventricular ejection fraction and clinical status were re-assessed in all surviving patients after 61 +/- 11 months. Major adverse cardiac events occurred with similar frequency in both groups. When compared with baseline, LVEF assessed by magnetic resonance imaging at 61 months decreased by 3.3 +/- 9.5% in the control group and by 2.5 +/- 11.9% in the BMC group (P = 0.30). Patients with an infarct transmurality > median appeared to benefit from BMC transfer throughout the 61-month study period (P = 0.040).

CONCLUSION

A single intracoronary application of BMCs does not promote a sustained improvement of LVEF in STEMI patients with relatively preserved systolic function. It is conceivable that a subgroup of patients with more transmural infarcts may derive a sustained benefit from BMC therapy. However, this needs to be tested prospectively in a randomized trial.