Optimization of mRNA extraction from human nasal mucosa biopsies for gene expression profile analysis by qRT-PCR.

Quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) is the gold-standard method for analyzing modifications in gene expression in cells and tissues. However, large quantities of high-quality RNA samples are needed for analyzing the expression of multiple genes from one human tissue sample. Here, we provide an optimized protocol for extracting large amounts of RNA from human nasal mucosal biopsies. The quality and quantity of samples were sufficient for qRT-PCR analyses of the expressions of various genes, in duplicate. In contrast to other protocols, we optimized RNA isolation to increase the amount from nasal biopsy samples for analyses of multiple genes. In most previous publications, expressions of only one or a few genes, including housekeeping genes, were analyzed because the amount of biological material was small. We were able to improve our protocol with respect to the yield and quality of RNA. This is likely to produce better results from molecular analyses of very small biopsy samples of human nasal mucosa.

Novel functions of S1P in chronic itchy and inflammatory skin diseases.

S1P is a pleotropic sphingolipid signalling molecule that acts through binding to five high-affinity G-protein coupled receptors. S1P-signaling affects cell fate in a multitude of ways, e.g. influencing cell differentiation, proliferation, and apoptosis, as well as playing an important role in immune cell trafficking. Though many effects of S1P-signaling in the human body have been discovered, the full range of functions is yet to be understood. For inflammatory skin diseases such as atopic dermatitis and psoriasis, evidence is emerging that dysfunction and imbalance of the S1P-axis is a contributing factor. Multiple studies investigating the efficacy of S1PR modulators in alleviating the severity and symptoms of skin conditions in various animal models and human clinical trials have shown promising results and validated the interest in the S1P-axis as a potential therapeutic target. Even though the involvement of S1P-signalling in inflammatory skin diseases still requires further clarification, the implications of the recent findings may prompt expansion of research to additional skin conditions and more S1P-axis modulatory pharmaceuticals.

Aluminium release and fluid warming: provocational setting and devices at risk.

BACKGROUND: Fluid warming, recommended for fluid rates of > 500 ml h-1, is an integral part of patient temperature management strategies. Fluid warming devices using an uncoated aluminium containing heating element have been reported to liberate aluminium resulting in critical aluminium concentrations in heated fluids. We investigated saline solution (0.9%), artificially spiked with organic acids to determine the influence of fluid composition on aluminium release using the uncoated enFlow® device. Additionally, the Level1® as a high volume fluid warming device and the ThermoSens® device were investigated with artificial spiked fluid at high risk for aluminum release and a clinically used crystalloid solution. RESULTS: Saline solution spiked with lactate more than acetate, especially at a non neutral pH, led to high aluminium release. Next to the enFlow® device, aluminium release was observed for the Level1® device, but not for the coated ThermoSens®-device. CONCLUSION: Uncoated aluminium containing fluid warming devices lead to potentially toxic levels of aluminium in heated fluids, especially in fluids with non-neutral pH containing organic acids and their salts like balanced electrolyte solutions.

Conductive heating mattress leads to ECG changes that mimic pacemaker spikes.

Hypothermia is a common perioperative complication. To prevent perioperative hypothermia amongst other things electrical heating mattresses are used. We have made an observation with the use of an electrical heating mattress that may confuse users. In this case the ECG monitoring suddenly showed spikes that looked like spikes from an implanted pacemaker. When turning off the heating mattress the spikes disappeared and returned after turning on the heating mattress again.

[Intraoperative vascular air embolism : Evidence for risks, diagnostics and treatment]. / Intraoperative vaskuläre Luftembolie : Evidenz bei Risiko, Diagnostik und Therapie.

The entry of gases into the vascular system is called vascular air embolism (VAE). The blocking of the pulmonary circulation by VAE can lead to fulminant right-sided heart failure and cardiocirculatory arrest. A VAE can occur at any time if there is an open connection between the environment and a venous vessel with subatmospheric pressure. This situation occurs during ear nose throat surgery, hip surgery, surgery of the lesser pelvis or breast surgery, if the surgical field is above the level of the heart; however, a VAE can also occur during routine tasks, such as insertion or removal of a central venous catheter or during endoscopic procedures with the insufflation of gas.Because during these procedures VAE is not the main focus of the anesthesia or surgery personnel, in such situations its sudden unexpected occurrence can have severe consequences. In contrast, in cardiac surgery or neurosurgery the risk of intraoperative VAE is much better known. In procedures with a higher risk of a clinically relevant VAE, a patent foramen ovale should be ruled out by preoperative transesophageal echocardiography (TEE). Intraoperatively TEE is the most sensitive procedure not only to detect a VAE but also to visualize the clinical expression, e.g. acute right heart overload.The avoidance of an initial and repeated air embolism is the primary measure to minimize the incidence and severity of VAE.Intraoperatively the following measures should be undertaken: excellent communication between anesthesia and surgery personnel with predetermined actions, maintenance of normal volume, patient positioning with minimal difference in height between heart and head, state of the art surgical technique with closure of potential air entry sites, sufficient detection of air by TEE, repeated jugular vein compression during neurosurgery, intraoperative Trendelenburg positioning of the patient during persisting or clinically evident VAE, differentiated adjustment of ventilatory settings and catecholamine treatment, aspiration of the blood-air mixture (air lock) at the junction of the superior vena cava and right atrium through a large bore central venous line and keeping check of the coagulation status.

Aluminium release by coated and uncoated fluid-warming devices.

The use of fluid-warming systems is recommended for infusion rates > 500 ml.h-1 to avoid peri-operative hypothermia. Some fluid-warming devices use disposable aluminium-heated plates for heat transfer, but there is no protective coating to separate the fluid from the heated aluminium surface. It is unknown if this could promote release of aluminium into infusion fluids. We investigated a coated (Fluido compact) and an uncoated (enFlow) fluid-warming device using normal saline or balanced electrolyte solution as infusion fluids, pumped through the heated disposables at flow rates of 2, 4 and 8 ml.min-1 for 60 min each. Aluminium concentrations in the fluid samples were analysed using graphite furnace atomic absorption spectrometry. With saline the coated and uncoated devices yielded aluminium concentrations below the level of quantification (< 128 µg.l-1 ). Similarly, balanced electrolyte solution in the coated device yielded aluminium concentrations < 128 µg.l-1 . However, balanced electrolyte solution in the uncoated device yielded aluminium concentrations of up to 6794 (3465-8002 [1868-7421]) µg.l-1 . Repeating this last study at a flow rate of 2 ml.min-1 resulted in quite high aluminium concentrations when the uncoated device was not heated (~1000 µg.l-1 ) and higher concentrations after the device was heated. We conclude that using uncoated aluminium plates in fluid-warming systems can lead to a risk of administering potentially harmful concentrations of aluminium when balanced crystalloid solutions are used. The mechanism is unclear, but heat is in part involved. Coating for aluminium within medical devices in direct contact with infusion fluids should be recommended.

[Prewarming according to the AWMF S3 guidelines on preventing inadvertant perioperative hypothermia 2014 : Retrospective analysis of 7786 patients]. / Vorwärmung entsprechend der "S3 Leitlinie Vermeidung von unbeabsichtigter perioperativer Hypothermie 2014" : Retrospektive Analyse von 7786 Patienten.

BACKGROUND: Inadvertent perioperative hypothermia, which is defined as a core body temperature of less than 36.0 °C, can have serious consequences in surgery patients. These include cardiac complications, increased blood loss, wound infections and postoperative shivering; therefore, the scientific evidence that inadvertent perioperative hypothermia should be avoided is undisputed and several national guidelines have been published summarizing the scientific evidence and recommending specific procedures. The German AWMF guidelines were the first to emphasize the importance of prewarming for surgery patients to avoid inadvertant perioperative hypothermia; however, in contrast to intraoperative warming, prewarming is so far not sufficiently implemented in clinical practice in many hospitals. Furthermore, a recent study has questioned the effectiveness of prewarming. OBJECTIVE: The aim of this retrospective investigation was to evaluate the hypothermia rates that can be achieved when prewarming in the anesthesia induction room is introduced into the clinical practice and performed in addition to intraoperative warming. MATERIAL AND METHODS: The ethics committee of the Medical Faculty of the Martin Luther University Halle Wittenberg gave approval for data storage and retrospective data analysis from the anesthesia database. According to the existing local standard operating procedure, prewarming with forced air was performed in addition to intraoperative warming in the anesthesia induction room in 3899 patients receiving general anesthesia with a duration of 30 min or longer from January 2015 to December 2016. The results were compared with a control group of 3887 patients from July 2012 to August 2014 who received intraoperative warming but were not subjected to prewarming. Tracheal intubation was carried out in all patients and temperature measurements after the induction of anesthesia were performed using esophageal, urinary catheter or intra-arterial temperature probes. RESULTS: The mean duration of prewarming was 25 min in the treatment group. Patients subjected to prewarming showed an intraoperative hypothermia rate of 15.8% and a postoperative hypothermia rate of 5.1%. Patients without prewarming showed an intraoperative hypothermia rate of 30.4% and a postoperative hypothermia rate of 12.4%. This means a 52% reduction of the intraoperative hypothermia rate and a 41% reduction of the postoperative hypothermia rate for patients who received prewarmimg (p < 0.0001). Multivariate logistic regression revealed that the lack of prewarming was independently associated with intraoperative hypothermia with an odds ratio of 2.5 (95% confidence interval CI 2.250-2.841; p < 0.0001) and postoperative hypothermia with an odds ratio of 2.8 (95% CI 2.316-3.277; p < 0.0001). CONCLUSION: Prewarming, as recommended in the AWMF guidelines, resulted in a significant and clinically relevant reduction in the incidence of inadvertent perioperative hypothermia; therefore, prewarming can still be regarded as an effective method to avoid perioperative hypothermia. Hypothermia rates of 15.8% intraoperatively and 5.1% postoperatively can be achieved in clinical practice, when prewarming is performed in addition to intraoperative warming in the anesthesia induction room directly before the start of surgical procedures.

[Neurophysiological monitoring during surgical procedures]. / Neurophysiologisches Monitoring bei operativen Eingriffen.

The application of intraoperative neurophysiological monitoring (IONM) is gaining more and more importance in daily clinical practice. The use of IONM allows the localization of neural structures and to control functioning of the peripheral and central nervous systems in anesthetized patients. This enables surgeons to identify and to protect neural structures and cerebral areas. The use of IONM also enables anesthesiologists to adjust anesthesia and cardiopulmonary therapy to the individual needs of the patient. Thereby, it may be possible to reduce the incidence of postoperative delirium and the incidence of postoperative cognitive deficits. To exploit the full potential anesthesiologists and surgeons must be able to use the methods of IONM safely and understand the results; therefore, basic knowledge of the technology, options and limitations of IONM is necessary. It is also important to be aware of the influence of anesthetics on the methods of IONM. Total intravenous anesthesia (TIVA) is the anesthetic method of choice, because it has only minimal influence on IONM methods. It is important to avoid bolus injections of hypnotics to achieve stable blood concentrations. Long- acting neuromuscular blocking agents should be avoided, because they disturb the signals of electromyography and motor-evoked potentials. By using IONM anesthesiologists and surgeons can identify changes in the function of the peripheral and central nervous system prior to irreversible damage.

[Implementation of a thermal management concept to prevent perioperative hypothermia : Results of a 6­month period in clinical practice]. / Umsetzung eines Wärmemanagementkonzeptes zur Vermeidung von perioperativer Hypothermie : Ergebnisse eines Sechsmonatszeitraums in der klinischen Praxis.

BACKGROUND: Perioperative hypothermia is defined as a core temperature below 36 °C. The literature shows that perioperative hypothermia is a frequent but potentially preventable complication of the surgical process. The risk of experiencing perioperative hypothermia is inherent for all anesthetized patients, independent of the type of surgery. Unless preventative measures are taken, perioperative hypothermia occurs in 50 to 70 % of all surgical patients. In Germany and Austria the guideline "Preventing inadvertent perioperative hypothermia" has been published. In Wolfsburg we started already in 2012 with a standard operating procedure to prevent perioperative hypothermia in all surgical patients. In two clinical departments we established an additional prewarming-protocol starting prior to induction of anaesthesia on the normal ward on the day of surgery. MATERIAL AND METHODS: For a period of 6 months we analyzed all temperature data of patients having undergone surgery, beginning before the start of general anaesthesia until the end of the operation. RESULTS: In total 3228 patients were enrolled into the study. Prewarming was performed in 1329 patients. In 1902 patients active warming was limited to the intraoperative period. The total rate of hypothermia in all patients was 32.6 %, whereas the rate of hypothermia at the end of the operation was 19.3 %. In the group of patients without prewarming the overall rate was 39.1 vs. 25 % at the end of the operation. In the groups of patients with prewarming the total rates of hypothermia were 25.2 and 24.7 % overall and 14.4 and 12.5 % at the end of the operation. In multifactorial regression it could be shown that patients without prewarming had a 1.8-fold increased risk of perioperative hypothermia compared to patients with intraoperative warming only. CONCLUSION: We conclude that temperature management is a challenge in the clinical situation, and that it is difficult to achieve rates of hypothermia close to zero. The addition of prewarming was very effective in improving the results in our patients.

[Tracheal bronchus and contralateral pneumonectomy]. / Trachealer Bronchusabgang und kontralaterale Pneumonektomie.

One-lung ventilation is a standard procedure for many types of lung surgery. The anesthesiologist can be challenged if unknown anomalies of the bronchial tree occur. We report a patient with a tracheal bronchus on the right side presenting for left pneumonectomy, and present one possible solution to airway management.

[Perioperative thermal management in Germany varies depending on the hospital size]. / Perioperatives Wärmemanagement in Abhängigkeit von der Krankenhausgröße in Deutschland.

BACKGROUND: Improvement of quality of care and patient safety while decreasing costs are major challenges in healthcare systems. This challenge includes the avoidance of perioperative hypothermia to reduce the associated adverse effects, length of stay and treatment costs. Due to the medical and economic relevance the national S3 guidelines for the prevention of perioperative hypothermia were recently published. AIM: This study presents and analyses the reality of utilization of thermal management in German hospitals depending on the size of the hospital, which is based on the number of beds. MATERIAL AND METHODS: Based on the data of an online survey among all members of the German Society of Anesthesiology and Intensive Care Medicine about perioperative thermal management, a subgroup analysis differentiating between the size of hospitals was performed. The survey included questions about the structural and organizational conditions, the practical implementation of temperature measurement and warming therapy and the developmental status of clinical standard operating procedures (SOP) and educational training. RESULTS: Comparing the structural quality, major differences were found with respect to the availability of core body temperature measurement and the provision of warming devices especially at different peripheral anesthesia workplaces as well as the existence of SOPs and educational training. The availability increased with hospital size. With respect to process quality, the frequency of prewarming increased with hospital size as well as the frequency of intraoperative temperature measurements during different anesthesia procedures. CONCLUSION: Major differences were found in several aspects of perioperative thermal management depending on the hospital size. The main potential for improvement was found in smaller hospitals. Developmental needs primarily exist in the configuration of peripheral anesthesia workplaces, educational training, implementation of SOPs and prewarming of patients.

Hypoglycaemia and predisposing factors among clinical subgroups treated with intensive insulin therapy.

BACKGROUND: In previous studies, conflicting intensive insulin therapy (IIT) results have been observed, whereby IIT-related mortality seems to be lower in specific clinical subgroups. The aim of this study was to assess differences in glycaemic control, the risk of critical hypoglycaemia (≤ 2.2 mmol/l), the associated predisposing factors, and the in-hospital mortality in different clinical subgroups treated with IIT. METHODS: Prospective, observational study in a university-affiliated intensive care unit (ICU) conducted from 2004 to 2005. All patients (n = 1667) belonging to one of the six most common surgical intervention groups (cardiac, neuro, abdominal, vascular, orthopaedic, and spinal surgeries) and medical patients were included. IIT was performed with a target blood glucose level of 4.4-7.8 mmol/l. Different indices were analysed to evaluate glucose control and glycaemic variability. RESULTS: The rate of critical hypoglycaemia was significantly different within the different clinical subgroups and varied from 0.8% to 4.5%. Similar results were obtained for hyperglycaemia. Multivariable analyses for the predisposing factors of critical hypoglycaemia showed a heterogeneous distribution pattern among the different clinical subgroups. Similar results were obtained for the risk factors of in-hospital mortality. CONCLUSION: The risk of critical hypoglycaemia and the associated predisposing factors depended on the clinical subgroup involved. Critical hypoglycaemia is a potential threat for our patients, and the high risk of critical hypoglycaemia in some clinical subgroups appeared to reverse the benefits of IIT. As a result, it is crucial that the different subgroups involved in a study are defined to further interpret the potential benefits of IIT and the risk of critical hypoglycaemia.

[Prewarming. Yesterday's luxury, today's minimum requirement]. / Vorwärmung. Von der Kür zur Pflicht.

Prewarming is a useful and effective measure to reduce perioperative hypothermia. Due to §23(3) of the German Infektionsschutzgesetz (Gesetz zur Verhütung und Bekämpfung von Infektionskrankheiten beim Menschen, Infection Act, act on protection and prevention of infectious diseases in man) and the recommendations of the Hospital Hygiene and Infection Prevention Committee of the Robert Koch Institute, implementation of prewarming is clearly recommended. There are several technically satisfactory and practicable devices available allowing prewarming on the normal hospital ward, in the preoperative holding area or in the induction room of the operating theater (OR) The implementation of prewarming requires additional equipment and training of staff. Using a locally adapted concept for the implementation of prewarming does not lead to inefficiency in the perioperative process. In contrast, the implementation can help to achieve stable arrival times for patients in the OR.

Microoptical array projectors for free-form screen applications.

The system design of front-projection systems for free-form screens utilizing conventional single-aperture optical layouts always requires a trade-off between system complexity and achievable luminous output. This article presents novel slide pre-processing algorithms based on array projection technology that are able to resolve the design drawbacks for both free-form as well as strongly-inclined planar screen applications by breaking the common contradiction between system simplicity and flux. Starting from describing common design strategies and their drawbacks, the theoretical basics of the novel concept are investigated and applied to raytracing simulations. Experimental results are shown and evaluated regarding their optical performance.

[Efficacy of a novel warming blanket: prospective randomized trial]. / Effektivität einer neuen Wärmedecke: Prospektive randomisierte Studie.

BACKGROUND: Perioperative hypothermia is a common complication of general anesthesia and occurs in up to 50 % of patients during ear, nose and throat (ENT) surgery. In this prospective, randomized controlled study the hypothesis that a new conductive warming blanket (Barrier® EasyWarm®, Mölnlycke Health Care Erkrath, Germany) is better in reducing the incidence of perioperative hypothermia in ENT surgery than insulation with a conventional hospital duvet alone was tested. MATERIALS AND METHODS: After approval of the local ethics committee and written informed consent 80 patients with a planned procedure time between 1 and 3 h were recruited. Anesthesia was induced and maintained using propofol, remifentanil and rocuronium and the core temperature was measured using an esophageal temperature probe. Patients in the study group were warmed at least 30 min prior to induction of anesthesia using the novel warming blanket (Barrier® EasyWarm®) and patients in the control group were insulated with a standard hospital duvet. Data were tested using Fisher's exact test, Student's t-test or the Mann-Whitney U-test as appropriate. Time-dependent changes in core temperature were evaluated using repeated measures analysis of variance (ANOVA) and post hoc Scheffé's test. Results are expressed as mean ± SD or as median and interquartile range (IQR) as appropriate. A p < 0.05 was considered to be statistically significant. RESULTS: The ANOVA did not identify a significantly higher core temperature in the study group at any time point. Furthermore, Fisher's exact test showed no differences in the incidence of intraoperative (12 out of 29 versus 10 out of 32 patients, p = 0.44) or postoperative hypothermia (12 out of 29 versus 9 out of 32 patients, p = 0.30) between the groups. No adverse effects were observed. CONCLUSIONS: In the studied patient group the new conductive warming blanket (Barrier® EasyWarm®) showed no superiority compared to conventional thermal insulation alone.

Palaeoecological data indicates land-use changes across Europe linked to spatial heterogeneity in mortality during the Black Death pandemic.

The Black Death (1347-1352 CE) is the most renowned pandemic in human history, believed by many to have killed half of Europe's population. However, despite advances in ancient DNA research that conclusively identified the pandemic's causative agent (bacterium Yersinia pestis), our knowledge of the Black Death remains limited, based primarily on qualitative remarks in medieval written sources available for some areas of Western Europe. Here, we remedy this situation by applying a pioneering new approach, 'big data palaeoecology', which, starting from palynological data, evaluates the scale of the Black Death's mortality on a regional scale across Europe. We collected pollen data on landscape change from 261 radiocarbon-dated coring sites (lakes and wetlands) located across 19 modern-day European countries. We used two independent methods of analysis to evaluate whether the changes we see in the landscape at the time of the Black Death agree with the hypothesis that a large portion of the population, upwards of half, died within a few years in the 21 historical regions we studied. While we can confirm that the Black Death had a devastating impact in some regions, we found that it had negligible or no impact in others. These inter-regional differences in the Black Death's mortality across Europe demonstrate the significance of cultural, ecological, economic, societal and climatic factors that mediated the dissemination and impact of the disease. The complex interplay of these factors, along with the historical ecology of plague, should be a focus of future research on historical pandemics.

Cartesian oval representation of freeform optics in illumination systems.

The geometrical method for constructing optical surfaces for illumination purpose developed by Oliker and co-workers [Trends in Nonlinear Analysis (Springer, 2003)] is generalized in order to obtain freeform designs in arbitrary optical systems. The freeform is created by a set of primitive surface elements, which are generalized Cartesian ovals adapted to the given optical system. Those primitives are determined by Hamiltonian theory of ray optics. The potential of this approach is demonstrated by some examples, e.g., freeform lenses with collimating front elements.

Breakthrough in purification of fossil pollen for dating of sediments by a new large-particle on-chip sorter.

Particle sorting is a fundamental method in various fields of medical and biological research. However, existing sorting applications are not capable for high-throughput sorting of large-size (>100 micrometers) particles. Here, we present a novel on-chip sorting method using traveling vortices generated by on-demand microjet flows, which locally exceed laminar flow condition, allowing for high-throughput sorting (5 kilohertz) with a record-wide sorting area of 520 micrometers. Using an activation system based on fluorescence detection, the method successfully sorted 160-micrometer microbeads and purified fossil pollen (maximum dimension around 170 micrometers) from lake sediments. Radiocarbon dates of sorting-derived fossil pollen concentrates proved accurate, demonstrating the method's ability to enhance building chronologies for paleoenvironmental records from sedimentary archives. The method is capable to cover urgent needs for high-throughput large-particle sorting in genomics, metabolomics, and regenerative medicine and opens up new opportunities for the use of pollen and other microfossils in geochronology, paleoecology, and paleoclimatology.

[Preoperative prewarming as a routine measure. First experiences]. / Präoperative Vorwärmung in der klinischen Routine. Erste Erfahrungen.

BACKGROUND: Despite the broad application of intraoperative warming new studies still show a high incidence of perioperative hypothermia. Therefore a prewarming program in the preoperative holding area was started. METHODS: The efficacy of the prewarming program was assessed with an accompanying quality assurance check sheet over a period of 3 months. RESULTS: During the 3 month test period 127 patients were included. The median length from arrival in the holding area to beginning prewarming was 6 min and the average duration of prewarming was 46±38 min. During prewarming the core temperature rose by 0.3±0.4°C to 37.1±0.5°C and decreased to 36.3±0.5°C after induction of anesthesia. At the end of the operation the core temperature was 36.4±0.5°C and 14% of the patients were hypothermic. CONCLUSION: These data allow 2 conclusions: 1. Prewarming in the holding area is possible with a sufficient duration. 2. Prewarming is highly efficient even when performed over a relatively short duration.