Determinants of Neurological Outcome Following Elective and Emergency Open Thoracoabdominal Aortic Aneurysm Repair-A Retrospective Multi-Center Study.

Background/Objectives: This study aimed to evaluate and establish the incidence of all types of neurological complications at our high-volume reference center for open TAAA repair in the Netherlands and Germany. Additionally, we sought to identify predictors for various neurological complications. Methods: This retrospective study was conducted in accordance with the STROBE guidelines, with the aim of reporting neurological outcomes for all patients who underwent open thoracoabdominal aortic aneurysm repair at two centers (Maastricht-Aachen) from 2000 to 2023, and to examine the association between these outcomes and pre- and perioperative parameters. The primary endpoints of the study were all-cause mortality, spinal cord ischemia (SCI), stroke, intracerebral bleeding (ICB), critical illness polyneuropathy/myopathy (CIP/CIM), and recurrent laryngeal nerve paralysis. Results: A total of 577 patients were operated on for open TAAA repair in two centers. The total in-hospital mortality rate was 20.6%, while the elective cases in-hospital mortality rate was 14.6%. In all, 28.2% of patients experienced neurological complications. The spinal cord ischemia rate was 7.5%, intracerebral bleeding 3.6%, stroke 5.9%, critical illness polyneuropathy 3.5%, and laryngeal nerve paresis 5.7%. Crawford extent II was significantly associated with increased neurological complications (OR 2.05, 95% CI 1.39-3.03, p = 0.003), while Crawford extent III and IV were significantly associated with fewer postoperative neurological complications (OR 0.61 (0.38-0.98) p = 0.04) (OR 0.52 (0.30-0.92) p = 0.02). Preoperative ASA score > 3 (OR 1.76, 95% CI 1.16-2.67, p = 0.007), COPD (OR 1.82, 95% CI 1.19-2.78, p = 0.006), massive intraoperative transfusion (OR 1.48, 95% CI 1.01-2.17, p = 0.04), and reinterventions during hospital stay (OR 1.98, 95% CI 1.36-2.89, p < 0.001) and surgery time (p =< 0.001) were significantly associated with neurological complications. Patients with neurological complications had higher rates of other postoperative morbidities. Conclusions: Neurological complications after open TAAA repair remain a significant concern, with identified risk factors associated with increased morbidity, mortality, and resource utilization. Identifying at-risk patients could potentially lead to a reduction in neurological complications.

Asbestos Surveillance Program Aachen (ASPA): Cancer mortality among asbestos exposed power industry workers.

BACKGROUND: The time between initial asbestos exposure and asbestos-related disease can span several decades. The Asbestos Surveillance Program aims to detect early asbestos-related diseases in a cohort of 8,565 power industry workers formerly exposed to asbestos. RESEARCH QUESTION: How does asbestos exposure patterns affect cancer mortality and the duration of latency until death? METHODS: A mortality follow-up was conducted with available vital status for 8,476 participants (99 %) and available death certificates for 89.9 % of deceased participants. Standardised mortality ratios (SMR) were calculated for asbestos-related cancers. The SMR of mesothelioma and lung cancer were stratified by exposure duration, cumulative asbestos exposure and smoking. The effect of age at first exposure, cumulative asbestos exposure and smoking on the duration of latency until death was examined using multiple linear regression analysis. RESULTS: The mortality risk of mesothelioma (n = 104) increased with cumulative asbestos exposure but not with exposure duration; the highest mortality (SMR: 23.20; 95 % CI: 17.62-29.99) was observed in participants who performed activities with short extremely high exposures (steam turbine revisions). Lung cancer mortality (n = 215) was not increased (SMR: 1.03; 95 % CI: 0.89-1.17). Median latency until death was 46 (15-63) years for mesothelioma and 44 (15-70) years for lung cancer and deaths occurred between age 64 and 82 years. Latency until death was not influenced by age at first exposure, cumulative exposure, or smoking. CONCLUSION: Cumulative dose seems to be more appropriate than exposure duration for estimating the risk of mesothelioma death. Additionally, exposure with high cumulative doses in short time should be considered. Since only lung cancer mortality, not incidence, was recorded in this study, lung cancer risk associated with asbestos exposure could not be assessed and the lung cancer mortality was lower than expected probably due to screening effects and improved treatments. The critical time window of death from asbestos-related cancer is between the seventh and ninth decade of life. Future studies should further explore the concept of latency, especially since large ranges are reported throughout the literature.

Pain-induced effects on the pupillary light response under high and low illumination conditions.

Objective: The present study investigated the impact of two different light intensities on the pain-modulated pupillary light response (PLR). Additionally, it aimed to demonstrate parasympathetic and sympathetic influences on PLR parameters in response to pain, as predicted by functional models. Method: A total of 24 participants were included in a randomized, repeated-measures design. The PLR was measured in response to both dark and bright light stimuli within two test cycles. Pain was induced using the cold pressor test (CPT), which involved immersing participants' feet in ice water. PLR measurements were taken during baseline and ice-water immersion within each test cycle. The assessed PLR parameters included initial diameter (INIT), latency (LAT), amplitude (AMP), and re-dilation time (ReDIL25). Along with these parameters, heart rate (HR) and pain ratings were also computed and analyzed. Main results: The CPT caused moderate pain in participants, and the resulting PLR parameters were found to be congruent with the expected parasympathetic and sympathetic nervous system activities. Although the luminance of the stimulus did influence PLR parameters, no interaction with pain exposure was found. Significance: The results showed that different aspects of pain experienced by an individual, as modulated through the sympathetic and parasympathetic nervous systems, are visible in their pupillary reactions to light. Notably, within the range used in the current study, light intensity did not significantly affect the pain-related PLR effects.

Evaluation and Comparison of Relaxation-Related Workplace Interventions Among Office Workers at an Insurance Institution: An Intervention Study.

Relaxation-related workplace interventions can be counterstrategies for stress due to office work and should be evaluated for success after implementation. This study reports on the evaluation and comparison of 3 relaxation techniques introduced as an intervention for health promotion. A Germany-wide multicenter evaluation of a 3-month relaxation intervention (30 min, once a week) including autogenic training, progressive muscle relaxation (PMR) or Tai Chi was conducted at 14 locations as an intervention study. Anonymous questionnaires (n = 244) were used to collect self-reports of perceived stress after the courses. Status before the courses (pre) and after completion (post) were reported at the end of the intervention. All 3 relaxation techniques were able to improve the subjective perception of stress (SPS) score. Autogenic training was reported to improve all singular items with large effects, whereas only 2 items showed change for Tai Chi and none for PMR. Singular items were also influenced by the location of the courses. All 3 methods were able to improve stress-related outcomes in terms of stress perception and individual aspects of stress management. For this specific intervention autogenic training yielded the largest and wide-ranging effects. Tai Chi was also effective, but additional effect due to an associated increase in physical activity were not found. For a workplace intervention PMR could not be recommended based on this study. The literature on workplace interventions is surprisingly scarce, and future studies should focus on the selection of appropriate participants while avoiding potential bias.

Lung cancer risk and occupational pulmonary fibrosis: systematic review and meta-analysis.

BACKGROUND: Molecular pathways found to be important in pulmonary fibrosis are also involved in cancer pathogenesis, suggesting common pathways in the development of pulmonary fibrosis and lung cancer. RESEARCH QUESTION: Is pulmonary fibrosis from exposure to occupational carcinogens an independent risk factor for lung cancer? STUDY DESIGN AND METHODS: A comprehensive search of PubMed, Embase, Web of Science and Cochrane databases with over 100 search terms regarding occupational hazards causing pulmonary fibrosis was conducted. After screening and extraction, quality of evidence and eligibility criteria for meta-analysis were assessed. Meta-analysis was performed using a random-effects model. RESULTS: 52 studies were identified for systematic review. Meta-analysis of subgroups identified silicosis as a risk factor for lung cancer when investigating odds ratios for silicosis in autopsy studies (OR 1.47, 95% CI 1.13-1.90) and for lung cancer mortality in patients with silicosis (OR 3.21, 95% CI 2.67-3.87). Only considering studies with an adjustment for smoking as a confounder identified a significant increase in lung cancer risk (OR 1.58, 95% CI 1.34-1.87). However, due to a lack of studies including cumulative exposure, no adjustments could be included. In a qualitative review, no definitive conclusion could be reached for asbestosis and silicosis as independent risk factors for lung cancer, partly because the studies did not take cumulative exposure into account. INTERPRETATION: This systematic review confirms the current knowledge regarding asbestosis and silicosis, indicating a higher risk of lung cancer in exposed individuals compared to exposed workers without fibrosis. These individuals should be monitored for lung cancer, especially when asbestosis or silicosis is present.

Short-Term Outcomes and Efficacy of Percutaneous Deep Vein Arterialization for No-Option Critical Limb Ischemia: A Systematic Review and Meta-Analysis.

BACKGROUND: Percutaneous deep vein arterialization (pDVA) is considered a treatment modality in patients with no-option critical limb ischemia. However, there is still a paucity of evidence regarding its safety and efficacy. DATA SOURCES: MEDLINE (via PubMed), Embase and Web of Science databases as well as the CENTRAL registry up to the end of June 2023. METHODS: This review adhered to the PRISMA guidelines (PROSPERO registration no. CRD42023445171). The risk of bias was assessed using the methodological index for non-randomized studies (MINORS). Primary endpoints included technical success, overall survival and limb salvage during the follow-up. Amputation-free survival at 30 days, 6 months and 1 year as well as complete wound healing, major adverse limb events and reintervention were investigated as secondary outcomes. RESULTS: Five observational studies, comprising 208 patients (142 Rutherford class 5/77 Rutherford class 6), were included. MINORS revealed a low risk of bias. The meta-analysis reached a pooled technical success rate of 96.2% (95% CI: 91.5-98.4), an overall survival of 82.8% (95% CI: 70.5-95.2) and a limb salvage rate of 77.2% (95% CI: 65.2-89.1) during the follow-up. The amputation-free survival at 30 days, 6 months and 1 year was 87.8%, 68.7% and 65.6%, respectively. Furthermore, pDVA resulted in a complete wound healing rate of 53.4% (95% CI: 30.3-76.5). The pooled reintervention rate was as high as 46.7% (37.1-56.3%). CONCLUSIONS: PDVA seems a feasible bail-out strategy for patients with no option for routine treatment of CLTI. However, due to the small number of studies, the strength of the evidence is low.

Factors Associated with Early Mortality in Acute Type A Aortic Dissection-A Single-Centre Experience.

BACKGROUND: Acute aortic dissection type A (AADA) is a surgical emergency with relevant mortality and morbidity despite improvements in current management protocols. Identifying patients at risk of a fatal outcome and controlling the factors associated with mortality remain of paramount importance. METHODS: In this retrospective observational study, we reviewed the medical records of 117 patients with AADA, who were referred to our centre and operated on between 2005 and 2021. Preoperative, intraoperative, and postoperative variables were analysed and tested for their correlation with in-hospital mortality. RESULTS: The overall survival rate was 83%. Preoperatively, factors associated with mortality were age (p = 0.02), chronic hypertension (p = 0.02), any grade of aortic valve stenosis in the patient's medical history (p = 0.03), atrial fibrillation (p = 0.04), and oral anticoagulation (p = 0.04). Non-survivors had significantly longer operative times (p = 0.002). During the postoperative phase, mortality was strongly associated with acute kidney injury (AKI) (p < 0.001), acute heart failure (p < 0.001), stroke (p = 0.02), focal neurological deficits (p = 0.02), and sepsis (p = 0.001). In the multivariate regression analysis, the onset of postoperative focal neurological deficits was the best predictor of a fatal outcome after adjusting for ARDS (odds ratio: 5.8, 95%-CI: 1.2-41.7, p = 0.04). CONCLUSIONS: In this retrospective analysis, atrial fibrillation, oral anticoagulation, hypertension, and age were significantly correlated with mortality. Postoperatively, acute kidney injury, acute heart failure, sepsis, and focal neurological deficits were correlated with in-hospital mortality, and focal neurological deficit has been identified as a significant predictor of fatal outcomes. Early detection and interdisciplinary management of at-risk patients remain crucial throughout the postoperative phase.

Posttraumatic stress disorder and quality of life in patients after open thoracoabdominal aortic repair.

Background: Open thoracoabdominal aortic aneurysm (TAAA) repair is often related to significant morbidity and complications like paraplegia or acute kidney injury. Subsequently, prolonged intensive care stay is common. However, there is a lack of research on post-traumatic stress disorder (PTSD) and the perceived quality of life (QOL) in patients undergoing complex aortic procedures, such as open TAAA repair. Therefore, our study aims to determine the prevalence of PTSD and the current QOLin these patients and whether it is associated with demographic factors or complications following open thoracoabdominal aortic repair. Patients and methods: In this retrospective study, a total of 213 adult surviving patients after open thoracoabdominal aortic repair were contacted with two questionnaires one to assess PTSD and another to evaluate current QOL after open thoracoabdominal aortic repair. 61 patients returned one or both the questionnaires, and 59 patients (97%) answered all questions of the 4-item primary care PTSD section of the survey. In addition to the PTSD screening, patients were sent an SF-36 questionnaire to assess their current quality of life. 60 patients answered the SF-36 questionnaire partially or completely (98%). Results: 27% of patients (16/59) screened positive for PTSD. Electronic medical records were matched to all responding patients. Patients who were screened positive for PTSD spent more days in intensive care (OR, 1.073; 95% CI 1.02-1.13; p=0.005), had a higher frequency of tracheotomy (OR, 6.43; 95% CI 1.87-22.06; p=0.004), sepsis (OR, 5.63; 95% CI 1.56-20.33; p=0.014), as well as postoperative paraparesis (OR, 13.23; 95% CI 1.36-129.02; p=0.019). In patients with postoperative complications, a statistically significant decrease in the overall score was observed for certain categories of the SF-36. Conclusions: The prevalence of PTSD is higher, in comparison to the general population's prevalence, and the quality of life is affected following open thoracoabdominal aortic aneurysm repair, with a significant relation to postoperative complications as well as the length of ICU stay. Further research and screening for PTSD in relation to open TAAA repair is needed to assess its role in patient QOL during follow up.

Evaluation of a Workplace Active Rest Program in Office Workers With Comparison of a Prospective and Retrospective Survey.

Physical activity-related workplace interventions can be counterstrategies for physical inactivity due to office work. Newly introduced programs should be evaluated for success. This study aimed to evaluate the intervention of a workplace active rest program and to compare a prospective and retrospective design of evaluation. A Germany-wide multicenter evaluation of a 3-month workplace active rest program (30 min, once a week) was carried out at 14 locations with a longitudinal pre/post design by means of an anonymous questionnaire (npre = 405, npost = 369). The participants' program-related changes in targeted characteristics regarding posture, function, complaints and physical awareness were collected with a questionnaire in a prospective design and afterward retrospectively. The prospective evaluation showed a significant improvement in the target characteristic "postural muscles in the neck area". In the retrospective survey, all target characteristics improved significantly. There were no differences between locations. The workplace active rest program in this study had positive effects on the perception of postural neck muscle status regardless of prospective or retrospective approach. Selection of survey mode should depend on desired outcome and consecutive influencing factors. In this specific case, retrospective survey could give more indirect information about overall satisfaction with the program and job although being influenced by response bias. Recall bias should be relatively small for shorter time periods assessed. Future studies should account for corresponding bias and specifics of target characteristics regardless of the chosen approach to survey.

The role of the DC component in human perception of AC-DC hybrid electric fields and a comparison with the AC component.

As part of the energy transition in Germany, high-voltage overhead power lines will be operated using hybrid systems that combine alternating and direct current (AC and DC). The degree to which humans perceive hybrid electric fields (EFs) is dependent on the proportion of both EF types. To investigate the impact of the DC component, a study assessed 49 participants with above-average EF detection ability under conditions with a low DC component of 1-4 kilovolts per meter (kV/m) and varying AC EFs between 1 and 14 kV/m. The detection thresholds of combined AC/DC EFs decreased with an increase in the DC component and ranged from 9.6 to 6.83 kV/m on average for the group. The results suggest that even minor variations in the DC component significantly affect human perception of hybrid EFs. These findings complement the results of an earlier study that investigated the AC component in hybrid EFs. Correlational analyses of both studies demonstrated the reliability of participants' performance. This study contributes to our understanding of EF-related effects on human perception and can aid in the planning of energy transmission near areas where humans work or live.

Effects of repetition as training and incentives on the performance in pulmonary function tests in healthy volunteers.

Pulmonary function testing (PFT) is a central part of diagnosis and treatment monitoring in respiratory medicine. Few studies have investigated whether repeated PFT or training can significantly influence performance. To investigate potential training effects of repeated PFT, 30 healthy volunteers underwent daily and weekly repeated PFT with spirometry over 10 weeks. The study included 22 females and 8 males with a mean age of 31.8 years ± 15 (SD), a mean weight of 66.3 kg ± 14.5 (SD) and a mean BMI of 22.4 ± 3.3 (SD). The first 5 PFTs were performed on 5 consecutive days, followed by 3 PFTs once a week on the same day of the week. Subsequently, 5 measurements were taken daily for 5 consecutive days. After these 13 appointments in 5 weeks, participants were randomly assigned to the control or incentive group, with stratification for age and gender. The incentive group had the opportunity to win money (200 €) for the highest increase in forced vital capacity (FVC). PFTs were performed once a week on the same day of the week as before for 5 more times. Motivation was assessed by a questionnaire before the 1st, 9th and 18th measure of PFT at three time points throughout the study. An increase in PFT was observed with mean increases of 473 [ml] in FVC, 395 [ml] in forced expiratory volume in 1 s (FEV1) and 1.382 [litres/second] in peak expiratory flow (PEF) after four days of daily PFT. These increases did not persist and spirometric data returned to baseline after one week. After allocation, participants in the incentive group did not increase their FVC, FEV1 or PEF compared to the control group. The incentive group showed higher motivation than the control group, even before allocation. Repeated daily PFT could induce short-term increases, but PFT does not fluctuate significantly in the long term. External influences that affect motivation could not consistently increase PFT. For clinical practice, it can be concluded that PFT does not necessarily require extended training to ensure reliability if reproducibility criteria are met.

Short-term exposure to zinc- and copper-containing welding fumes: Effects on pulmonary function in humans.

Zinc- and copper-containing welding fumes typically induce a systemic inflammation indicated by increase in C-reactive protein (CRP) levels, also known as welding fume fever. It typically includes symptoms like fever, myalgia or headaches, but only a quarter of patients experience respiratory symptoms, e.g. coughing. This retrospective analysis of data of three studies with either control (filtered air) or zinc- and copper-containing welding fume exposure aims to identify and characterize the effect of the welding fumes on lung function. Spirometry and body plethysmography data of male healthy volunteers were analyzed and comparisons between different timepoints after a 6 h exposure were conducted. For controls no significant changes in spirometry were observed between baseline and 6 h, 24 h and 1 week after exposure. For volunteers exposed to zinc- and copper-containing welding fumes no significant reductions in forced expiratory volume in 1 s (FEV1) and minimal reductions in vital capacity (VC) (52 ml, 0.9%) were detected after 6 h. After 24 h significant reductions in FEV1 (147 ml, 3.2%) and VC (162 ml, 2.9%) could be observed. 1 week after exposure FEV1 was still significantly reduced (102 ml, 2.1%) and airway resistance were increased while no differences in VC were detected. The reduction of FEV1% after 24 week significantly correlated with increases in CRP levels. In conclusion, a single exposure to zinc- and copper-containing welding fumes leads not only to a systemic inflammation but could also induce slight sustained airway constrictions after 24 h and 1 week. The observed slight airway constriction is not caused by immediate effects but possibly inflammatory processes. Although welding fume fever does not necessarily present respiratory symptoms, welders exposed to zinc- and copper-containing welding fumes should be monitored for respiratory symptoms and obstructive ventilation pattern.

Assessment of Feasibility and Patency of below the Knee Atherectomy Using the 1.5 mm Phoenix Catheter-A Retrospective Study.

Background and Objectives: Peripheral arterial disease (PAD) contains a significant proportion of patients whose main pathology is located in the infragenicular arteries. The treatment of these patients requires a deliberate consideration due to the threat of possible complications of an intervention. In this retrospective study, the feasibility of a below-the-knee atherectomy (BTKA) via a 1.5 mm Phoenix atherectomy catheter and the patient outcome over the course of 6 months are investigated. Materials and Methods: The data of patients suffering from PAD with an infragenicular pathology treated via 1.5 mm Phoenix™ atherectomy catheter between March 2021 and February 2022 were retrospectively analyzed. Prior to the intervention, after 2 weeks and 6 months, the PAD stages were graded and ankle-brachial-indeces (ABI) were measured. Results: The study shows a significant improvement of ABI, both after 2 weeks and 6 months. Additionally, the number of PAD stage IV patients decreased by 15.2% over the course of 6 months, and 18.2% of the patients improved to PAD stage IIa. Only one bleeding complication on the puncture side occurred over the whole study, and no other complications were observed. Conclusions: Phoenix™ atherectomy usage in the BTKA area seems to be feasible and related to a favorable outcome in this retrospective study.&nbsp.

Medical students' experiences of working with simulated patients in challenging communication training.

BACKGROUND: Physicians' communication skills are important for patient-centered care. Although working with simulated patients (SPs) in case simulations is common for training communication skills, studies seldom include a wide range of challenging behaviors or explore students' own experiences of learning communication skills with SPs. Therefore, this study was aimed at investigating how medical students perceive communication training involving challenging consultations with SPs and the impact on their learning experiences. METHODS: Twenty-three medical students from the same class were interviewed in focus groups about their experiences of simulation training with actors as SPs. In the simulation training, the students were instructed to deliver bad news, manage negative patient reactions, and encourage behavioral changes in reluctant patients. This was followed by feedback and a debriefing exercise. The interviews were analyzed with content analysis. RESULTS: Students reported that actors as SPs made the simulations more realistic and enabled them to practice various communication skills for challenging consultations in a safe way and manage their own feelings, thereby promoting new learning experiences. Elements such as actors' flexibility in changing behaviors during role-play and exposure to different challenging behaviors, like negative emotions, were regarded as valuable. The importance of an accepting and permissive climate for the debriefing exercise was highlighted, though without taking too much time from the simulation training. Feedback directly from the SP was appreciated. CONCLUSIONS: Actors as SPs were perceived as a valuable part of challenging communication training and added elements to the learning process. Future studies should include a wider range of challenging behaviors in training with SPs and evaluate the effects of such training on students' use of communication skills.

Functional changes in long-term incubated rat precision-cut lung slices.

BACKGROUND: Respiratory diseases represent a global health burden. Because research on therapeutic strategies of airway diseases is essential, the technique of precision-cut lung slices (PCLS) has been developed and widely studied. PCLS are an alternative ex vivo model and have the potential to replace and reduce in vivo animal models. So far, the majority of studies was conducted with short-term cultivated PCLS (≤ 72 h). As there is large interest in research of chronic diseases and chronic toxicity, feasibility of cultivating human PCLS long-term over 2 weeks and recently over 4 weeks was investigated by another research group with successful results. Our aim was to establish a model of long-term cultivated rat PCLS over a period of 29 days. METHODS: Rat PCLS were cultured for 29 days and analysed regarding viability, histopathology, reactivity and gene expression at different time points during cultivation. RESULTS: Cultivation of rat PCLS over a 29-day time period was successful with sustained viability. Furthermore, the ability of bronchoconstriction was maintained between 13 and 25 days, depending on the mediator. However, reduced relaxation, altered sensitivity and increased respiratory tone were observed. Regarding transcription, alteration in gene expression pattern of the investigated target genes was ascertained during long-term cultivation with mixed results. Furthermore, the preparation of PCLS seems to influence messenger ribonucleic acid (mRNA) expression of most target genes. Moreover, the addition of fetal bovine serum (FBS) to the culture medium did not improve viability of PCLS. In contrast to medium without FBS, FBS seems to affect measurements and resulted in marked cellular changes of metaplastic and/or regenerative origin. CONCLUSIONS: Overall, a model of long-term cultivated rat PCLS which stays viable for 29 days and reactive for at least 13 days could be established. Before long-term cultivated PCLS can be used for in-depth study of chronic diseases and chronic toxicity, further investigations have to be made.

Welding Fume Instillation in Isolated Perfused Mouse Lungs-Effects of Zinc- and Copper-Containing Welding Fumes.

Zinc- and copper-containing welding fumes can cause systemic inflammation after exposure in humans. Recent ex vivo studies have shown that the observed inflammation originates from exposed immune cells. In vitro studies identified the soluble fraction of metal particles as the main effectors. Isolated perfused mouse lungs (IPLs) were perfused and ventilated for 270 min. Lungs were instilled with saline solution (control), welding fume particle suspension (WFs) or the soluble fraction of the welding fumes (SF-WFs). Bronchoalveolar lavage fluid (BALF) and perfusate samples were analyzed for cytokine levels and lung tissue mRNA expression levels were analyzed via RT-PCR. All lungs instilled with WFs did not complete the experiments due to a fatal reduction in tidal volume. Accordingly, IL-6 and MPO levels were significantly higher in BALF of WF lungs compared to the control. IL-6 and MPO mRNA expression levels were also increased for WFs. Lungs instilled with SF-WFs only showed mild reactions in tidal volume, with BALF and mRNA expression levels not significantly differing from the control. Zinc- and copper-containing welding fume particles adversely affect IPLs when instilled, as evidenced by the fatal loss in tidal volume and increased cytokine expression and secretion. The effects are mainly caused by the particles, not by the soluble fraction.

Animal experiments in biomedical research: Knowledge, self-evaluation and attitudes of biology and medical students.

Animal experiments in biomedical research are debated in public, within the scientific community and among students. Despite increased efforts to reduce, refine and replace animal experiments, they remain integral components of the job of a biomedical scientist. In Germany, persons must have a university degree and adequate education and training to perform and direct animal experiments. Therefore, training courses such as FELASA (Federation of European Laboratory Animal Science Associations) courses are provided. However, in our experience, students become aware of this very late in their studies when decisions about their future careers have already been made. We initiated this study to have a better understanding of when and how animal experiments should be discussed during university education. We evaluated the knowledge, self-evaluation and attitudes of biology and medical students of different semesters regarding animal experiments at the RWTH Aachen University, Germany. An online survey was conducted to assess demographic information, knowledge about animal experiments, self-evaluation and attitudes towards animal experiments. Students of both fields showed limited knowledge of animal experiments. Biology students showed significantly better knowledge and self-evaluated their knowledge higher than medical students. The field of the study correlated with their knowledge and self-evaluation but did not predict participants' attitudes towards animal experiments. In conclusion, the current study showed that there is still room for improvement to raise awareness about laboratory animal science in the biomedical research field.

Never Change a Flowing System? The Effects of Retrograde Flow on Isolated Perfused Lungs and Vessels.

Retrograde perfusion may occur during disease, surgery or extracorporeal circulation. While it is clear that endothelial cells sense and respond to changes in blood flow, the consequences of retrograde perfusion are only poorly defined. Similar to shear stress or disturbed flow, retrograde perfusion might result in vasomotor responses, edema formation or inflammation in and around vessels. In this study we investigated in rats the effects of retrograde perfusion in isolated systemic vessels (IPV) and in pulmonary vessels of isolated perfused lungs (IPL). Anterograde and retrograde perfusion was performed for 480 min in IPV and for 180 min in the IPL. Perfusion pressure, cytokine levels in perfusate and bronchoalveolar lavage fluid (BALF), edema formation and mRNA expression were studied. In IPV, an increased perfusion pressure and initially also increased cytokine levels were observed during retrograde perfusion. In the IPL, increased edema formation occurred, while cytokine levels were not increased, though dilution of cytokines in BALF due to pulmonary edema cannot be excluded. In conclusion, effects of flow reversal were visible immediately after initiation of retrograde perfusion. Pulmonary edema formation was the only effect of the 3 h retrograde perfusion. Therefore, further research should focus on identification of possible long-term complications of flow reversal.

Blood collection technique, anticoagulants and storing temperature have minor effects on the isolation of polymorphonuclear neutrophils.

In the isolation of polymorphonuclear neutrophils (PMNs) the technique and other external factors can have great influence on the quality and quantity of isolated neutrophils. To elucidate the influence of the blood collection technique, anticoagulants and storing temperature on isolated PMNs healthy volunteers provided blood samples with different needles and collection techniques, anticoagulants (EDTA, heparin, citrate) and storing temperatures (4, 22, 37 °C). From each blood sample PMNs were isolated and compared regarding number of PMNs and oxidative burst. The blood collection technique, anticoagulants and storing temperature had minor impact on isolated PMNs. All three tested cannulas and anticoagulants can be used to obtain blood samples for PMN isolation. For storing temperatures 37 °C should be preferred. Regarding time between the PMN isolation and the actual experiments, a time span of maximum 1 h should be targeted.

No Observed Effect Level (NOEL) for Systemic Inflammation by Copper and Zinc in Welding Fumes.

: Copper and zinc containing welding fumes are able to induce systemic inflammation in healthy subjects. In this study the no observed effect levels (NOEL) for welding fumes containing either copper or zinc were assessed.Fifteen healthy male volunteers participated in an exposure. Each subject was exposed to two different concentrations of both, copper and zinc containing welding fumes. Exposure was performed in the Aachen Workplace Simulation Lab.The NOEL was found at metal concentrations between 0.2 and 0.3 mg/m for copper and between 0.8 and 1.2 mg/m for zinc.The NOEL identified in this study was about a factor of 10 higher than the German workplace threshold limit values (TLV). However, TLV in other countries was in the same range or even higher than the NOEL indicating a considerable risk for workers.