Quality of analgesic care in labor: A cross-sectional study of the first national register-based benchmarking system

OBJECTIVE

Unlike other types of acute pain, labor pain is considered physiological. Due to the heterogeneous management during labor, there is a lack of intention to define quality of care of peripartal analgesia. This study presents the first results of the national register for this evaluation.

METHODS

This prospective cross-sectional study, conducted in five different German level-three hospitals, included women after vaginal childbirth between January 2020 and January 2022. A validated questionnaire was completed 24 h postpartum, including information about labor pain, satisfaction, and expectations regarding analgesia. Data were centrally recorded with obstetric records using the database of the QUIPS (Quality Improvement in Postoperative Pain Management) Project.

RESULTS

A total of 514 women were included. On an 11-point Numerical Rating Scale, pain intensity during labor was severe (8.68 ± 1.8) while postpartal pain was 3.9 (±2.1). The second stage of labor was considered the most painful period. Only 62.6% of the parturients obtained pharmacological support, with epidural being the most effective (reduction of 3.8 ± 2.8 points). Only epidural (odds ratio [OR] 0.22) and inhalation of nitrous oxide (OR 0.33) were protective for severe pain. In benchmarking, a relation between satisfaction, pain intensity, and the use of epidural was found; 40.7% of the women wished they had received more analgesic support during labor.

CONCLUSION

This study highlights deficiencies in analgesic management in high-level perinatal centers, with more than 40% of parturients considering actual practices as insufficient and wishing they had received more analgesic support, despite the availability of analgesic options. Using patient-reported outcomes can guarantee qualitative tailored analgesic care in women.

Side-chain dynamics of the α1B -adrenergic receptor determined by NMR via methyl relaxation

G protein-coupled receptors (GPCRs) are medically important membrane proteins that sample inactive, intermediate, and active conformational states characterized by relatively slow interconversions (~μs-ms). On a faster timescale (~ps-ns), the conformational landscape of GPCRs is governed by the rapid dynamics of amino acid side chains. Such dynamics are essential for protein functions such as ligand recognition and allostery. Unfortunately, technical challenges have almost entirely precluded the study of side-chain dynamics for GPCRs. Here, we investigate the rapid side-chain dynamics of a thermostabilized α1B -adrenergic receptor (α1B -AR) as probed by methyl relaxation. We determined order parameters for Ile, Leu, and Val methyl groups in the presence of inverse agonists that bind orthosterically (prazosin, tamsulosin) or allosterically (conopeptide ρ-TIA). Despite the differences in the ligands, the receptor's overall side-chain dynamics are very similar, including those of the apo form. However, ρ-TIA increases the flexibility of Ile1764×56 and possibly of Ile2145×49 , adjacent to Pro2155×50 of the highly conserved P5×50 I3×40 F6×44 motif crucial for receptor activation, suggesting differences in the mechanisms for orthosteric and allosteric receptor inactivation. Overall, increased Ile side-chain rigidity was found for residues closer to the center of the membrane bilayer, correlating with denser packing and lower protein surface exposure. In contrast to two microbial membrane proteins, in α1B -AR Leu exhibited higher flexibility than Ile side chains on average, correlating with the presence of Leu in less densely packed areas and with higher protein-surface exposure than Ile. Our findings demonstrate the feasibility of studying receptor-wide side-chain dynamics in GPCRs to gain functional insights.

Early Molecular Insights into Thanatin Analogues Binding to A. baumannii LptA

The cationic antimicrobial ß-hairpin, thanatin, was recently developed into drug-like analogues active against carbapenem-resistant Enterobacteriaceae (CRE). The analogues represent new antibiotics with a novel mode of action targeting LptA in the periplasm and disrupting LPS transport. The compounds lose antimicrobial efficacy when the sequence identity to E. coli LptA falls below 70%. We wanted to test the thanatin analogues against LptA of a phylogenetic distant organism and investigate the molecular determinants of inactivity. Acinetobacter baumannii (A. baumannii) is a critical Gram-negative pathogen that has gained increasing attention for its multi-drug resistance and hospital burden. A. baumannii LptA shares 28% sequence identity with E. coli LptA and displays an intrinsic resistance to thanatin and thanatin analogues (MIC values > 32 µg/mL) through a mechanism not yet described. We investigated the inactivity further and discovered that these CRE-optimized derivatives can bind to LptA of A. baumannii in vitro, despite the high MIC values. Herein, we present a high-resolution structure of A. baumannii LptAm in complex with a thanatin derivative 7 and binding affinities of selected thanatin derivatives. Together, these data offer structural insights into why thanatin derivatives are inactive against A. baumannii LptA, despite binding events in vitro.

Peptidomimetic antibiotics disrupt the lipopolysaccharide transport bridge of drug-resistant Enterobacteriaceae

The rise of antimicrobial resistance poses a substantial threat to our health system, and, hence, development of drugs against novel targets is urgently needed. The natural peptide thanatin kills Gram-negative bacteria by targeting proteins of the lipopolysaccharide transport (Lpt) machinery. Using the thanatin scaffold together with phenotypic medicinal chemistry, structural data, and a target-focused approach, we developed antimicrobial peptides with drug-like properties. They exhibit potent activity against Enterobacteriaceae both in vitro and in vivo while eliciting low frequencies of resistance. We show that the peptides bind LptA of both wild-type and thanatin-resistant Escherichia coli and Klebsiella pneumoniae strains with low-nanomolar affinities. Mode of action studies revealed that the antimicrobial activity involves the specific disruption of the Lpt periplasmic protein bridge.

TBIO-08. The molecular basis for rational targeting of FGFR-driven growth and invasiveness in pediatric brain tumors

The oncogenic activation of receptor tyrosine kinases (RTK) promotes growth, survival and dissemination in pediatric tumors including glioma, ependymoma and medulloblastoma (MB). Direct targeting of either the RTK or of downstream kinases can effectively block tumor promoting pathway functions. However, emergence of resistance is common. We hypothesized that alternative interference strategies that target protein-protein interactions (PPIs) instead of enzymatic activities could overcome the emergence of resistance. We characterized the molecular interactions downstream of the FGFR that regulate relevant growth and invasion-promoting mechanisms in MB cells, to identify potentially druggable PPIs. We found that the FRS2 protein is an essential up-stream effector of FGFR signaling towards invasiveness. Using a proteomics approach, we furthermore identified the Striatin 3 protein as a novel oncogenic effector of the FGFR pathway downstream of FRS2, as it integrates antagonistic growth and invasion signals downstream of FGFR. Mechanistically, Striatin 3 interacts with the Ser/Thr kinase MAP4K4, couples it to the protein phosphatase 2A, and thereby inactivates growth repressing activities of MAP4K4. In parallel, Striatin 3 enables MAP4K4-mediated phosphorylation of PKC-theta and VASP, which combined are necessary to promote tissue invasion. To selectively repress pro-invasive FGFR functions, we identified and functionally validated small molecule ligands of FRS2, that prevent FRS2 activation and downstream signaling. We demonstrate efficacy of these compounds in inhibiting invasion and growth promoting activities in vitro and in vivo, and identified potential off-target activities of the ligand using a proteome-wide interaction analysis. We propose inhibition of FRS2 by a small molecular PTB domain ligand as a strategy to repress FGF signaling in FGFR-driven tumors. The development of this ligand, and the de novo design of functional analogs thereof bear promise for further pre-clinical evaluation of these structures as anti-growth promoting and anti-metastatic therapeutics applicable to FGFR-driven tumors.

Fluvial Depositional Systems of the African Humid Period: An Analog for an Early, Wet Mars in the Eastern Sahara

A widely hypothesized but complex transition from widespread fluvial activity to predominantly aeolian processes is inferred on Mars based on remote sensing data observations of ancient landforms. However, the lack of analysis of in situ martian fluvial deposits hinders our understanding of the flow regime nature and sustainability of the martian fluvial activity and the hunt for ancient life. Studying analogs from arid zones on Earth is fundamental to quantitatively understanding geomorphic processes and climate drivers that might have dominated during early Mars. Here we investigate the formation and preservation of fluvial depositional systems in the eastern Sahara, where the largest arid region on Earth hosts important repositories of past climatic changes. The fluvial systems are composed of well-preserved single-thread sinuous to branching ridges and fan-shaped deposits interpreted as deltas. The systems' configuration and sedimentary content suggest that ephemeral rivers carved these landforms by sequential intermittent episodes of erosion and deposition active for 10-100s years over ∼10,000 years during the late Quaternary. Subsequently, these landforms were sculpted by a marginal role of rainfall and aeolian processes with minimum erosion rates of 1.1 ± 0.2 mm/yr, supplying ∼96 ± 24 × 10¹⁰ m³ of disaggregated sediment to adjacent aeolian dunes. Our results imply that similar martian fluvial systems preserving single-thread, short distance source-to-sink courses may have formed due to transient drainage networks active over short durations. Altogether, this study adds to the growing recognition of the complexity of interpreting climate history from orbital images of landforms.

Crystal structure of the α1B-adrenergic receptor reveals molecular determinants of selective ligand recognition

α-adrenergic receptors (αARs) are G protein-coupled receptors that regulate vital functions of the cardiovascular and nervous systems. The therapeutic potential of αARs, however, is largely unexploited and hampered by the scarcity of subtype-selective ligands. Moreover, several aminergic drugs either show off-target binding to αARs or fail to interact with the desired subtype. Here, we report the crystal structure of human α_1BAR bound to the inverse agonist (+)-cyclazosin, enabled by the fusion to a DARPin crystallization chaperone. The α_1BAR structure allows the identification of two unique secondary binding pockets. By structural comparison of α_1BAR with α₂ARs, and by constructing α_1BAR-α_2CAR chimeras, we identify residues 3.29 and 6.55 as key determinants of ligand selectivity. Our findings provide a basis for discovery of α_1BAR-selective ligands and may guide the optimization of aminergic drugs to prevent off-target binding to αARs, or to elicit a selective interaction with the desired subtype.

This study reports the X-ray structure of the α_1B-adrenergic G protein-coupled receptor bound to an inverse agonist, and unveils key determinants of subtype-selective ligand binding that may help the design of aminergic drugs with fewer side-effects.

Effects of supplementing a CP-reduced diet with rumen-protected methionine on Fleckvieh bull fattening

The objective of this study was to evaluate the effect of supplementing a CP-reduced diet with rumen-protected methionine on growth performance of Fleckvieh bulls. A total of 69 bulls (367 ± 25 kg BW) were assigned to three feeding groups (n = 23 per group). The control (CON) diet contained 13.7% CP and 2.11 g methionine/kg diet (both DM basis) and was set as positive control. The diet reduced in CP (nitrogen) (RED) diet as negative control and the experimental RED + rumen-protected methionine (MET) diet were characterised by deficient CP concentrations (both 9.04% CP). The RED + MET diet differed from the RED diet in methionine concentration (2.54 g/kg DM vs. 1.56 g/kg DM, respectively) due to supplementation of rumen-protected methionine. Rumen-protected lysine was added to both RED and RED + MET at 2.7 g/kg DM to ensure a sufficient lysine supply relative to total and metabolisable protein intake. Metabolisable energy (ME) and nutrient composition were similar for CON, RED, and RED + MET. Bulls were fed for 105 days (d) on average. Individual feed intake was recorded daily; individual BW was recorded at the beginning of the experiment, once per month, and directly before slaughter. At slaughter, blood samples were collected and carcass traits were assessed. Reduction in dietary CP concentration reduced feed intake, and in combination with lower dietary CP concentration, daily intake of CP for RED and RED + MET was lower compared with CON (P < 0.01). Daily ME intake was reduced in RED and RED + MET compared with CON (P < 0.01). Consequently growth performance and carcass weights were reduced (both P < 0.01) in both RED and RED + MET compared with CON. Supplemental rumen-protected methionine was reflected in increased serum methionine concentration in RED + MET (P < 0.05) as compared to RED but it did not affect growth performance, carcass traits and serum amino acid (AA) concentrations, except for lysine which was reduced (P < 0.01) compared to CON and RED. In conclusion, bulls fed RED or RED + MET diets were exposed to a ruminal CP deficit and subsequently a deficit of prececal digestible protein, but methionine did not appear to be the first-limiting essential AA for growth under the respective experimental conditions.

Peptides in BioNMR Research

Heteronuclear NMR in combination with isotope labelling is used to study folding of polypeptides induced by metals in the case of metallothioneins, binding of the peptidic allosteric modulator ρ-TIA to the human G-protein coupled α_1b adrenergic receptor, the development of therapeutic drugs that interfere with the biosynthesis of the outer membrane of Gram-negative bacteria, and a system in which protein assembly is induced upon peptide addition. NMR in these cases is used to derive precise structural data and to study the dynamics.

Analysis of Compositional Gradients in Cu(In,Ga)(S,Se)2 Solar Cell Absorbers Using Energy Dispersive X-ray Analysis with Different Acceleration Energies

The efficiency of Cu(In,Ga)(S,Se)₂ (CIGSSe) solar cell absorbers can be increased by the optimization of the Ga/In and S/Se gradients throughout the absorber. Analyzing such gradients is therefore an important method in tracking the effectiveness of process variations. To measure compositional gradients in CIGSSe, energy dispersive X-ray analysis (EDX) with different acceleration energies performed at both the front surface and the backside of delaminated absorbers was used. This procedure allows for the determination of compositional gradients at locations that are millimeters apart and distributed over the entire sample. The method is therefore representative for a large area and yields information about the lateral homogeneity in the millimeter range. The procedure is helpful if methods such as secondary ion-mass (SIMS), time-of-flight SIMS, or glow-discharge optical emission spectrometry (GDOES) are not available. Results of such EDX measurements are compared with GDOES, and they show good agreement. The procedure can also be used in a targeted manner to detect local changes of the gradients in inhomogeneities or points of interest in the µm range. As an example, a comparison between the compositional gradients in the regular absorber and above the laser cut separating the Mo back contact is shown.

[Delayed incision time of the first case : Analysis of incidences and causes and the effect of list planning instability]

BACKGROUND

Delays in beginning operations in the morning lead to a loss of valuable operating time and can cause frustration among the medical personnel involved.

OBJECTIVE

So far there are no prospective, multicentric investigations of the incidence and reasons for delayed first incision times in the morning. The effect of planning list instability of first cases on late operating room starts has not yet been evaluated.

MATERIAL AND METHODS

In this multicenter prospective study delays in surgical incision time in all first cases of the day were investigated in 36 German and Swiss hospitals (14 surgical specialties) over a period of 2 weeks.

RESULTS

A total of 3628 first of the day cases were included in the study. Looking at all subspecialties combined 50.8% of the first cases of the day were delayed by more than 5 min and in 30.2% of cases longer than 15 min. Incidences of delayed surgical incision time >5 min ranged from 40.0% (gynecology) to 66.8% (neurosurgery). The main reasons for delays in ascending order were prolonged induction of anesthesia compared to the planned time, the delayed appearance of the surgeon and prolonged preparation for surgery. The incidence of delays in incision times for planning list instability was increased by 10% and the average delay increased by 7 min.

CONCLUSION

Delays in surgical incision times of the first operation of the day have a high incidence in most surgical specialties; however, the reasons for delays are manifold. Plan instability of operating room lists with respect to the first cases has a negative effect on the punctuality of the incision time and should therefore be avoided.

MODL-14. SMALL MOLECULE TARGETING OF ONCOGENIC FGF2-FGFR SIGNALING IN BRAIN TUMORS

FGF2, the ligand of FGF receptors (FGFRs), is expressed in the developing and adult brain. FGF2-FGFR1 signaling causes the induction and maintenance of cancer stem cells through ERK-dependent up-regulation of ZEB1 and Olig2 in glioblastoma. In SHH medulloblastoma, Olig2 triggers tumor initiation from GCPs, maintains quiescent stem-like cells during the disease and contributes to tumor outgrowth at recurrence. We found that FGF2-FGFR signaling causes increased growth and tissue invasion through the FGFR adaptor protein FRS2 in SHH and group-3 medulloblastoma ¹. Thus, targeting of FGFR-FRS2 signaling could abrogate brain tumor growth and spread by repressing tumor-promoting functions that are induced by microenvironmental FGF2. Using virtual screening combined with functional validation, we identified protein-protein interaction inhibitors (F2i) that bind FRS2 and abrogate FGFR signaling to the MAP-ERK pathway. Consistent with the requirement of FRS2 for pro-invasive signaling downstream of FGFR1 in medulloblastoma, F2i also efficiently block FGF2-induced migration and invasion in medulloblastoma-derived cells. Selected F2i display excellent binding kinetics with a similar Kd as the natural ligand domain of FGFR and cause steric alterations in the targeted protein domain. On-target activity was confirmed by thermal proteome profiling. Neither in silico screening nor empirical testing revealed significant off-target activity of the compounds. No toxicity of F2i was observed in cell-based models with confirmed functional activity on invasion and MAPK activation. Thus, we identified novel, low molecular weight pharmacological protein-protein interaction inhibitors with an excellent potential to specifically block FGFR functions relevant for brain tumor progression. 1. Santhana Kumar et al., CellReports23, 3798–3812.e8 (2018).

Dynamics of Bacteriorhodopsin in the Dark-Adapted State from Solution Nuclear Magnetic Resonance Spectroscopy

To achieve efficient proton pumping in the light-driven proton pump bacteriorhodopsin (bR), the protein must be tightly coupled to the retinal to rapidly convert retinal isomerization into protein structural rearrangements. Methyl group dynamics of bR embedded in lipid nanodiscs were determined in the dark-adapted state, and were found to be mostly well ordered at the cytosolic side. Methyl groups in the M145A mutant of bR, which displays only 10 % residual proton pumping activity, are less well ordered, suggesting a link between side-chain dynamics on the cytosolic side of the bR cavity and proton pumping activity. In addition, slow conformational exchange, attributed to low frequency motions of aromatic rings, was indirectly observed for residues on the extracellular side of the bR cavity. This may be related to reorganization of the water network. These observations provide a detailed picture of previously undescribed equilibrium dynamics on different time scales for ground-state bR.

Optimizing the α1B-adrenergic receptor for solution NMR studies

Sample preparation for NMR studies of G protein-coupled receptors faces special requirements: Proteins need to be stable for prolonged measurements at elevated temperatures, they should ideally be uniformly labeled with the stable isotopes ¹³C, ¹⁵N, and all carbon-bound protons should be replaced by deuterons. In addition, certain NMR experiments require protonated methyl groups in the presence of a perdeuterated background. All these requirements are most easily satisfied when using Escherichia coli as the expression host. Here we describe a workflow, starting from a temperature-stabilized mutant of the α_1B-adrenergic receptor, obtained using the CHESS methodology, into an even more stable species, in which flexible parts from termini were removed and the intracellular loop 3 (ICL3) was stabilized against proteolytic cleavage. The yield after purification corresponds to 1-2 mg/L of D₂O culture. The final purification step is ligand-affinity chromatography to ensure that only well-folded ligand-binding protein is isolated. Proper selection of detergent has a remarkable influence on the quality of NMR spectra. All optimization steps of sequence and detergent are monitored on a small scale by monitoring the melting temperature and long-term thermal stability to allow for screening of many conditions. The stabilized mutant of the α_1B-adrenergic receptor was additionally incorporated in nanodiscs, but displayed slightly inferior spectra compared to a sample in detergent micelles. Finally, both [¹⁵N,¹H]- as well as [¹³C,¹H]-HSQC spectra are shown highlighting the high quality of the final NMR sample. Importantly, the quality of [¹³C,¹H]-HSQC spectra indicates that the so prepared receptor could be used for studying side-chain dynamics.

Backbone and methyl assignment of bacteriorhodopsin incorporated into nanodiscs

Resonance assignments are challenging for membrane proteins due to the size of the lipid/detergent-protein complex and the presence of line-broadening from conformational exchange. As a consequence, many correlations are missing in the triple-resonance NMR experiments typically used for assignments. Herein, we present an approach in which correlations from these solution-state NMR experiments are supplemented by data from ¹³C unlabeling, single-amino acid type labeling, 4D NOESY data and proximity of moieties to lipids or water in combination with a structure of the protein. These additional data are used to edit the expected peaklists for the automated assignment protocol FLYA, a module of the program package CYANA. We demonstrate application of the protocol to the 262-residue proton pump from archaeal bacteriorhodopsin (bR) in lipid nanodiscs. The lipid-protein assembly is characterized by an overall correlation time of 44 ns. The protocol yielded assignments for 62% of all backbone (H, N, C^α, C^β, C') resonances of bR, corresponding to 74% of all observed backbone spin systems, and 60% of the Ala, Met, Ile (δ1), Leu and Val methyl groups, thus enabling to assign a large fraction of the protein without mutagenesis data. Most missing resonances stem from the extracellular half, likely due intermediate exchange line-broadening. Further analysis revealed that missing information of the amino acid type of the preceding residue is the largest problem, and that 4D NOESY experiments are particularly helpful to compensate for that information loss.

Combined Phenyl Silane and Immunoaffinity Column Cleanup with Liquid Chromatography for Determination of Ochratoxin A in Roasted Coffee: Collaborative Study

A collaborative study was conducted to evaluate a liquid chromatography (LC) method for ochratoxin A using sequential phenyl silane and immunoaffinity column cleanup. The method was tested at 3 different levels of ochratoxin A in roasted coffee, which spanned the range of possible future European regulatory limits. The test portion was extracted with methanol and sodium bicarbonate by shaking for 30 min. The extract was filtered, centrifuged, and then cleaned up on a phenyl silane column before being eluted from the washed column with methanol–water. The eluate was diluted with phosphate-buffered saline (PBS) and applied to an ochratoxin A immunoaffinity column, which was washed with water. The ochratoxin A was eluted with methanol, the solvent was evaporated, and the residue was redissolved in injection solvent. After injection of this solution onto a reversed-phase LC apparatus, ochratoxin A was measured by fluorescence detection. Eight laboratory samples of low-level naturally contaminated roasted coffee and 2 laboratory samples of blank coffee (&lt; 0.2 ng/g ochratoxin A at the signal-to-noise ratio of 3:1), along with ampules of ochratoxin A calibrant and spiking solutions, were sent to 15 laboratories in 13 different European countries. Test portions of the laboratory samples were spiked at levels of 4 ng/g ochratoxin A, and recoveries ranged from 65 to 97%. Based on results for spiked blank material (blind duplicates) and naturally contaminated material (blind duplicates at 3 levels), the relative standard deviation for repeatability (RSDr) ranged from 2 to 22% and the relative standard deviation for reproducibility (RSDR) ranged from 14 to 26%. The method showed acceptable within- and between-laboratory precision, as evidenced by HORRAT values, at the low level of determination for ochratoxin A in roasted coffee.

[Does hospital volume correlate with surgical process time? : Retrospective analysis of the five most common procedures for visceral surgery, trauma and orthopedic surgery and gynecology/obstetrics from the benchmarking program of the Berufsverband Deutscher Anästhesisten (BDA), Berufsverband Deutscher Chirurgen (BDC) and Verband für OP-Management (VOPM)]

BACKGROUND

Minimum volume thresholds for specific surgical procedures in German hospitals were established in 2004 but remain controversial. For the first time, this study investigated the relationship between hospital performance volume and surgical procedure duration in a multicenter approach. The question here was whether a concentration on frequently performed procedures leads to a reduction in surgical process times.

METHODS

In a retrospective analysis, the 5 most common procedures from visceral, trauma/orthopedic and gynecological/obstetrics surgery were examined in hospitals participating in a benchmarking program. For each procedure performed between 2013 and 2015, hospitals were divided into 4 groups depending on the hospital volume provided. The average surgical duration of incision to suture time was calculated between the group with "very low" hospital volume and the other three groups ("low", "high" and "very high").

RESULTS

OR cases from 75 hospitals were analyzed. The number of included cases per procedure ranged from 31,940 to 2705. The average number of operations performed in a specific procedure was 3-4 times higher in high-volume hospitals compared to very low-volume hospitals. A linear relationship between hospital volume and surgical process time only appeared to be clearly seen in laparoscopic cholecystectomy, appendectomy and arthroscopic meniscus surgery: a higher case load led to a reduction in incision to suture time. For the other procedures, the surgical process times were inconsistent between the hospital groups.

CONCLUSION

The case volume only appeared to have a direct but limited influence on incision to suture times in laparoscopic and arthroscopic procedures. Overall, the hospital performance volume appeared to be of subordinate importance in terms of OR-economics.

A cross-sectional study on preoperative anxiety in adults

OBJECTIVE

The main objective of this study was a detailed comparison of the level of anxiety about surgery and anesthesia. Other objectives included the assessment of the prevalence and intensity of preoperative anxiety.

METHODS

This cross-sectional single-center survey used the validated Amsterdam anxiety and information scale (APAIS) and a modified numeric rating scale (mNRS) to assess preoperative anxiety, anxiety about surgery and anxiety about anesthesia. Prevalences and intensities of anxieties were predominantly analyzed descriptively.

RESULTS

3200 patients were enrolled and 3087 (57% females) were analyzed. 92.6% reported preoperative anxiety according to APAIS scores. The average total APAIS anxiety score (APAIS-A-T) was 9.9 (SD 3.6). 40.5% reported high anxiety (defined as APAIS-A-T > 10). Mean anxiety about surgery (APAIS-A-Su) was higher than mean anxiety about anesthesia (APAIS-A-An): 5.5 (SD 2.1) vs. 4.3 (SD 1.9), p < 0.0001. Accordingly, more patients were substantially more afraid (score difference > 2) of surgery (642, 20.8%, 95% CI 19.4-22.3) than of anesthesia (48, 1.6%, 95% CI 1.2-2.1).

CONCLUSION

Preoperative anxiety is still very common among adult patients scheduled to undergo an elective procedure. Therefore, it should be evaluated routinely. Anxiety about surgery and anxiety about anesthesia differ in many patients. For this reason, anxiety about surgery and anxiety about anesthesia should be assessed separately. This would allow providing a more individualized support of patients to cope with their anxiety and could require particular attention by the surgeon or the anesthetist.

The Laryngectomee Substitute Voice: Image Processing of Endoscopic Recordings by Fusion with Acoustic Signals

Objectives: The most radical cancer therapy of the throat is the total excision of the larynx which postoperatively results in the loss of voice. A widely-used method of voice rehabilitation is the insertion of a silicone valve, which establishes an unidirectional connection between trachea and esophagus. Thus, during exhalation, air can be directed from the trachea into the esophagus. This air stream excites tissue vibrations of the esophagus and the hypo-pharynx which act as a substitute voice generator. Purpose of the current study is to present a technique for visualizing the dynamics of the substitute voice generating element.

Methods: Digital high speed videos of the vibrating tissue are simultaneously recorded with the emitted acoustic signal. The high speed sequences are directly evaluated by a three-step knowledge based algorithm. It considers correlation between image and acoustic data, information about the gray value of each pixel, and continuity of tissue vibration. The temporal properties of an image series are investigated by evaluating the time dependent gray value at each pixel position.

Results: The applicability of the algorithm is exemplar-ily demonstrated using the data of one male patient. It enables the identification of the regions within an image series which are mainly responsible for the acoustic signal. Additionally, the dynamics of tissue vibrations are visualized. The main propagation direction can be clearly identified.

Conclusions: The new methodology summarizes the information about endoscopic and acoustic recordings of substitute voice into a single image. The results allow a first estimation of tissue velocity and elastic properties of oscillating tissue.

[Palliative therapy concepts in intensive care medicine]

Involvement of palliative care is so far not common practice for critically ill patients on surgical intensive care units (ICUs) in Germany. The objectives of palliative care concepts are improvement of patient quality of life by relief of disease-related symptoms using an interdisciplinary approach and support of patients and their relatives considering their current physical, psychological, social and spiritual needs. The need for palliative care can be identified via defined screening criteria. Integration of palliative care can either be realized using a consultative model which focusses on involvement of palliative care consultants or an integrative model which embeds palliative care principles into the routine daily practice by the ICU team. Early integration of palliative care in terms of advance care planning (ACP) can lead to an increase in goals of care discussions and quality of life as well as a decrease of mortality and length of stay on the ICU. Moreover, stress reactions of relatives and ICU staff can be reduced and higher satisfaction with therapy can be achieved. The core of goal of care discussions is professional and well-structured communication between patients, relatives and staff. Consideration of palliative care principles by model-based integration into ICU practice can improve complex intensive care courses of disease in a productive but dignified way without neglecting curative attempts.

Effects of functional endoscopic sinus surgery on the acoustics of the sinonasal tract

BACKGROUND

Nasal and paranasal cavities are supposed to contribute substantially to the vocal tract resonator properties. However, their acoustical effects as well as the effects of sinus surgery on the voice remain unclear. In this work we investigate resonance phenomena of paranasal sinuses prior to and after various rhinosurgical procedures in cadaveric human sinonasal tracts and corresponding 3D casts.

METHODOLOGY

Nasal and paranasal cavities of formalin-preserved cadavers and corresponding 3D replicas were excited by sine-tone sweeps from an earphone placed in the epipharynx. The response was picked up by a microphone at the nostrils. Different FESS procedures were performed and the acoustical responses following excitation were recorded. The measured acoustical changes in the obtained transfer functions were then evaluated.

RESULTS

Marked low frequency dips were detected in the transfer functions when sinus cavities were included in the nasal resonator system. These dips showed a significant correlation with sinus volumes. Following FESS procedures they moved upwards in frequency depending on the extent of the surgical intervention.

CONCLUSIONS

The transfer functions obtained in cadaveric situs and 3D replicas showed dips at the resonance frequencies of the paranasal cavities. Marked acoustic effects in terms of increase in dip frequency following FESS procedures were reproducibly documented.

Fluorescent markers of various organelles in the wheat pathogen Zymoseptoria tritici

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17 vectors are described that allow labelling of 7 subcellular structures.

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The fluorescent markers target the plasma membrane, endoplasmic reticulum, nucleus.

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Markers also target the actin cytoskeleton, peroxisomes and autophagosomes.

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These markers complete are toolkit of fluorescent reporters.

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Reporters allow cell biological studies in the Septoria tritici blotch fungus.

Development of novel strategies to control fungal plant pathogens requires understanding of their cellular organisation and biology. Live cell imaging of fluorescent organelle markers has provided valuable insight into various aspects of their cell biology, including invasion strategies in plant pathogenic fungi. Here, we introduce a set of 17 vectors that encode fluorescent markers to visualize the plasma membrane, endoplasmic reticulum (ER), chromosomes, the actin cytoskeleton, peroxisomes and autophagosomes in the wheat pathogen Zymoseptoria tritici. We fused either enhanced green-fluorescent protein (eGFP) or a codon-optimised version of GFP (ZtGFP) to homologues of a plasma membrane-located Sso1-like syntaxin, an ER signalling and retention peptide, a histone H1 homologue, the LifeAct actin-binding peptide, a mitochondrial acetyl-CoA dehydrogenase, a peroxisomal import signal and a homologue of the ubiquitin-like autophagosomal protein Atg8. We expressed these markers in wildtype strain IPO323 and confirmed the specificity of these markers by counterstaining or physiological experiments. This new set of molecular tools will help understanding the cell biology of the wheat pathogen Z. tritici.

Triterpenes for Well-Balanced Scar Formation in Superficial Wounds

Triterpenes are demonstrably effective for accelerating re-epithelialisation of wounds and known to improve scar formation for superficial lesions. Among the variety of triterpenes, betuline is of particular medical interest. Topical betuline gel (TBG) received drug approval in 2016 from the European Commission as the first topical therapeutic agent with the proven clinical benefit of accelerating wound healing. Two self-conducted randomized intra-individual comparison clinical studies with a total of 220 patients involved in TBG treatment of skin graft surgical wounds have been screened for data concerning the aesthetic aspect of wound healing. Three months after surgery wound treatment with TBG resulted in about 30% of cases with more discreet scars, and standard of care in about 10%. Patients themselves appreciate the results of TBG after 3 months even more (about 50%) compared to standard of care (about 10%). One year after surgery, the superiority of TBG counts for about 25% in comparison with about 10%, and from the patients’ point of view, for 25% compared to 4% under standard of care. In the majority of wound treatment cases, there is no difference visible between TBG treatment and standard of care after 1 year of scar formation. However, in comparison, TBG still offers a better chance for discreet scars and therefore happens to be superior in good care of wounds.

Visible tumor surface response to physical plasma and apoptotic cell kill in head and neck cancer

The aim of the study was to learn, whether clinical application of cold atmospheric pressure plasma (CAP) is able to cause (i) visible tumor surface effects and (ii) apoptotic cell kill in squamous cell carcinoma and (iii) whether CAP-induced visible tumor surface response occurs as often as CAP-induced apoptotic cell kill. Twelve patients with advanced head and neck cancer and infected ulcerations received locally CAP followed by palliative treatment. Four of them revealed tumor surface response appearing 2 weeks after intervention. The tumor surface response expressed as a flat area with vascular stimulation (type 1) or a contraction of tumor ulceration rims forming recesses covered with scabs, in each case surrounded by tumor tissue in visible progress (type 2). In parallel, 9 patients with the same kind of cancer received CAP before radical tumor resection. Tissue specimens were analyzed for apoptotic cells. Apoptotic cells were detectable and occurred more frequently in tissue areas previously treated with CAP than in untreated areas. Bringing together both findings and placing side by side the frequency of clinical tumor surface response and the frequency of analytically proven apoptotic cell kill, detection of apoptotic cells is as common as clinical tumor surface response. There was no patient showing signs of an enhanced or stimulated tumor growth under influence of CAP. CAP was made applicable by a plasma jet, kINPen(®) MED (neoplas tools GmbH, Greifswald, Germany).

[Speech Ability and Psychological Outcome After Treatment of Oral Cancer]

BACKGROUND

In recent years interactions between surgical treatment of oral carcinoma and incidence of anxiety or depression have become a subject of discussions. This prospective study is a comparison between the extent of loss of speech intelligibility and presence of depressive symptoms or anxiety as a result of oral carcinoma.

MATERIAL AND METHODS

One year after surgical therapy for oral carcinoma, 90 patients of an average age of 60±12 years were examined. Their speech intelligibility degree was measured using standardized automatic speech recognition (word recognition rate, WR). Symptoms of anxiety and depression were detected by use of HAD-Scales (HADS). Next to the relationship between WR and HADS other influential variables related to WR and HADS were statistically evaluated.

RESULTS

The WR average was 53.2±17.2. Female WR was better than male. The difference between tumor classifications T1 and T4 compared to the WR reached statistical significance. Significant differences were detected between WR and "tumor localization", "graft donor site", "graft morphology", "tongue motility", and "tracheostoma" groups. There was a relationship between tongue motility and graft morphology, graft donor site and tumor localization. HAD-Scores in the mean were elevated: HADS-Total=43.3%, HADS-A=43.3% und HADS-D= 51.1%. WR correlates with HADS-D-Subscale, but not with HADS-A-Subscale.

CONCLUSION

Communication disorders as a result of neoplasmic orofacial surgery may be related to extent of the treatment and to affective impairments. This should receive attention in the concept of rehabilitation.

Fluorescent markers for the Spitzenkörper and exocytosis in Zymoseptoria tritici

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We establish Z. tritici polarity markers ZtSec4, ZtMlc1, ZtRab11, ZtExo70 and ZtSpa2.

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All markers localize correctly, labeling the Spitzenkörper and sites of polar exocytosis.

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We provide 5 carboxin-resistance conveying vectors for integration of all markers into the sdi1 locus.

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We provide 5 hygromycin B-resistance conveying vectors for random integration of all markers.

Fungal hyphae are highly polarized cells that invade their substrate by tip growth. In plant pathogenic fungi, hyphal growth is essential for host invasion. This makes polarity factors and secretion regulators potential new targets for novel fungicides. Polarization requires delivery of secretory vesicles to the apical Spitzenkörper, followed by polarized exocytosis at the expanding cell tip. Here, we introduce fluorescent markers to visualize the apical Spitzenkörper and the apical site of exocytosis in hyphae of the wheat pathogen Zymoseptoria tritici. We fused green fluorescent protein to the small GTPase ZtSec4, the myosin light chain ZtMlc1 and the small GTPase ZtRab11 and co-localize the fusion proteins with the dye FM4-64 in the hyphal apex, suggesting that the markers label the hyphal Spitzenkörper in Z. tritici. In addition, we localize GFP-fusions to the exocyst protein ZtExo70, the polarisome protein ZtSpa2. Consistent with results in the ascomycete Neurospora crassa, these markers did localize near the plasma membrane at the hyphal tip and only partially co-localize with FM4-64. Thus, these fluorescent markers are useful molecular tools that allow phenotypic analysis of mutants in Z. tritici. These tools will help develop new avenues of research in our quest to control STB infection in wheat.

A codon-optimized green fluorescent protein for live cell imaging in Zymoseptoria tritici

Fluorescent proteins (FPs) are powerful tools to investigate intracellular dynamics and protein localization. Cytoplasmic expression of FPs in fungal pathogens allows greater insight into invasion strategies and the host-pathogen interaction. Detection of their fluorescent signal depends on the right combination of microscopic setup and signal brightness. Slow rates of photo-bleaching are pivotal for in vivo observation of FPs over longer periods of time. Here, we test green-fluorescent proteins, including Aequorea coerulescens GFP (AcGFP), enhanced GFP (eGFP) from Aequorea victoria and a novel Zymoseptoria tritici codon-optimized eGFP (ZtGFP), for their usage in conventional and laser-enhanced epi-fluorescence, and confocal laser-scanning microscopy. We show that eGFP, expressed cytoplasmically in Z. tritici, is significantly brighter and more photo-stable than AcGFP. The codon-optimized ZtGFP performed even better than eGFP, showing significantly slower bleaching and a 20-30% further increase in signal intensity. Heterologous expression of all GFP variants did not affect pathogenicity of Z. tritici. Our data establish ZtGFP as the GFP of choice to investigate intracellular protein dynamics in Z. tritici, but also infection stages of this wheat pathogen inside host tissue.

Conditional promoters for analysis of essential genes in Zymoseptoria tritici

Development of new fungicides, needed for sustainable control of fungal plant pathogens, requires identification of novel anti-fungal targets. Essential fungal-specific proteins are good candidates, but due to their importance, gene deletion mutants are not viable. Consequently, their cellular role often remains elusive. This hindrance can be overcome by the use of conditional mutants, where expression is controlled by an inducible/repressible promoter. Here, we introduce 5 inducible/repressible promoter systems to study essential genes in the wheat pathogen Zymoseptoria tritici. We fused the gene for enhanced green-fluorescent protein (egfp) to the promoter region of Z. tritici nitrate reductase (Pnar1; induced by nitrogen and repressed by ammonium), 1,4-β-endoxylanase A (Pex1A; induced by xylose and repressed by maltodextrin), l-arabinofuranosidase B (PlaraB; induced by arabinose and repressed by glucose), galactose-1-phosphate uridylyltransferase 7 (Pgal7; induced by galactose and repressed by glucose) and isocitrate lyase (Picl1; induced by sodium acetate and repressed by glucose). This was followed by quantitative analysis of cytoplasmic reporter fluorescence under induced and repressed conditions. We show that Pnar1, PlaraB and Pex1A drive very little or no egfp expression when repressed, but induce moderate protein production when induced. In contrast, Pgal7 and Picl1 show considerable egfp expression when repressed, and were strongly induced in the presence of their inducers. Normalising the expression levels of all promoters to that of the α-tubulin promoter Ptub2 revealed that PlaraB was the weakest promoter (∼20% of Ptub2), whereas Picl1 strongly expressed the reporter (∼250% of Ptub2). The use of these tools promises a better understanding of essential genes, which will help developing novel control strategies that protect wheat from Z. tritici.

A gene locus for targeted ectopic gene integration in Zymoseptoria tritici

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We establish the sdi1 of Z. tritici locus for targeted integration of constructs as single copies.

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Integration of constructs conveys carboxin resistance.

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We provide a vector for integration of eGFP-expressing construct into the sdi1 locus.

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Integration into sdi1 locus is not affecting virulence of Z. tritici.

Understanding the cellular organization and biology of fungal pathogens requires accurate methods for genomic integration of mutant alleles or fluorescent fusion-protein constructs. In Zymoseptoria tritici, this can be achieved by integrating of plasmid DNA randomly into the genome of this wheat pathogen. However, untargeted ectopic integration carries the risk of unwanted side effects, such as altered gene expression, due to targeting regulatory elements, or gene disruption following integration into protein-coding regions of the genome. Here, we establish the succinate dehydrogenase (sdi1) locus as a single “soft-landing” site for targeted ectopic integration of genetic constructs by using a carboxin-resistant sdi1^R allele, carrying the point-mutation H267L. We use various green and red fluorescent fusion constructs and show that 97% of all transformants integrate correctly into the sdi1 locus as single copies. We also demonstrate that such integration does not affect the pathogenicity of Z. tritici, and thus the sdi1 locus is a useful tool for virulence analysis in genetically modified Z. tritici strains. Furthermore, we have developed a vector which facilitates yeast recombination cloning and thus allows assembly of multiple overlapping DNA fragments in a single cloning step for high throughput vector and strain generation.

Fluorescent markers of the endocytic pathway in Zymoseptoria tritici

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We establish Z. tritici fimbrin (ZtFim1) and small GTPases (ZtRab5, ZtRab7) as endocytic markers.

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All markers localize correctly, proven by live cell imaging and co-staining and pharmaceutical studies.

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We provide 3 carboxin-resistance conveying vectors for integration of all markers into the sdi1 locus.

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We provide 3 hygromycin B-resistance conveying vectors for random integration of all markers.

Hyphal growth in filamentous fungi is supported by the uptake (endocytosis) and recycling of membranes and associated proteins at the growing tip. An increasing body of published evidence in various fungi demonstrates that this process is of essential importance for fungal growth and pathogenicity. Here, we introduce fluorescent markers to visualize the endocytic pathway in the wheat pathogen Zymoseptoria tritici. We fused enhanced green-fluorescent protein (eGFP) to the actin-binding protein fimbrin (ZtFim1), which is located in actin patches that are formed at the plasma membrane and are participating in endocytic uptake at the cell surface. In addition, we tagged early endosomes by eGFP-labelling a Rab5-homologue (ZtRab5) and late endosomes and vacuoles by expressing eGFP-Rab7 homologue (ZtRab7). Using fluorescent dyes and live cell imaging we confirmed the dynamic behavior and localization of these markers. This set of molecular tools enables an in-depth phenotypic analysis of Z. tritici mutant strains thereby supporting new strategies towards the goal of controlling wheat against Z. tritici.

[How many patient transfer rooms are necessary for my OR suite? : Effect of the number of OR transfer rooms on waiting times and patient throughput in the OR - analysis by simulation]

INTRODUCTION

In most hospitals the operating rooms (OR) are separated from the rest of the hospital by transfer rooms where patients have to pass through for reasons of hygiene. In the OR transfer room patients are placed on the OR table before surgery and returned to the hospital bed after surgery. It could happen that the number of patients who need to pass through a transfer room at a certain point in time exceed the number of available transfer rooms. As a result the transfer rooms become a bottleneck where patients have to wait and which, in turn, may lead to delays in the OR suite. In this study the ability of a discrete event simulation to analyze the effect of the duration of surgery and the number of ORs on the number of OR transfer rooms needed was investigated.

METHODS

This study was based on a discrete event simulation model developed with the simulation software AnyLogic®. The model studied the effects of the number of OR transfer rooms on the processes in an OR suite of a community hospital by varying the number of ORs from one to eight and using different surgical portfolios. Probability distributions for the process duration of induction, surgery and recovery and transfer room processes were calculated on the basis of real data from the community hospital studied. Furthermore, using a generic simulation model the effect of the average duration of surgery on the number of OR transfer rooms needed was examined.

RESULTS

The discrete event simulation model enabled the analysis of both quantitative as well as qualitative changes in the OR process and setting. Key performance indicators of the simulation model were patient throughput per day, the probability of waiting and duration of waiting time in front of OR transfer rooms. In the case of a community hospital with 1 transfer room the average proportion of patients waiting before entering the OR was 17.9 % ± 9.7 % with 3 ORs, 37.6 % ± 9.7 % with 5 ORs and 62.9 % ± 9.1 % with 8 ORs. The average waiting time of patients in the setting with 3 ORs was 3.1 ± 2.7 min, with 5 ORs 5.0 ± 5.8 min and with 8 ORs 11.5 ± 12.5 min. Based on this study the community hospital needs a second transfer room starting from 4 ORs so that there is no bottleneck for the subsequent OR processes. The average patient throughput in a setting with 4 ORs increased significantly by 0.3 patients per day when a second transfer room is available. The generic model showed a strong effect of the average duration of surgery on the number of transfer rooms needed.

CONCLUSION

There was no linear correlation between the number of transfer rooms and the number of ORs. The shorter the average duration of surgery, the earlier an additional transfer room is required. Thus, hospitals with shorter duration of surgery and fewer ORs may need the same or more transfer rooms than a hospital with longer duration of surgery and more ORs. However, with respect to an economic analysis, the costs and benefits of installing additional OR transfer rooms need to be calculated using the profit margins of the specific hospital.

Hypericin-bearing magnetic iron oxide nanoparticles for selective drug delivery in photodynamic therapy

Combining the concept of magnetic drug targeting and photodynamic therapy is a promising approach for the treatment of cancer. A high selectivity as well as significant fewer side effects can be achieved by this method, since the therapeutic treatment only takes place in the area where accumulation of the particles by an external electromagnet and radiation by a laser system overlap. In this article, a novel hypericin-bearing drug delivery system has been developed by synthesis of superparamagnetic iron oxide nanoparticles (SPIONs) with a hypericin-linked functionalized dextran coating. For that, sterically stabilized dextran-coated SPIONs were produced by coprecipitation and crosslinking with epichlorohydrin to enhance stability. Carboxymethylation of the dextran shell provided a functionalized platform for linking hypericin via glutaraldehyde. Particle sizes obtained by dynamic light scattering were in a range of 55-85 nm, whereas investigation of single magnetite or maghemite particle diameter was performed by transmission electron microscopy and X-ray diffraction and resulted in approximately 4.5-5.0 nm. Surface chemistry of those particles was evaluated by Fourier transform infrared spectroscopy and ζ potential measurements, indicating successful functionalization and dispersal stabilization due to a mixture of steric and electrostatic repulsion. Flow cytometry revealed no toxicity of pure nanoparticles as well as hypericin without exposure to light on Jurkat T-cells, whereas the combination of hypericin, alone or loaded on particles, with light-induced cell death in a concentration and exposure time-dependent manner due to the generation of reactive oxygen species. In conclusion, the combination of SPIONs' targeting abilities with hypericin's phototoxic properties represents a promising approach for merging magnetic drug targeting with photodynamic therapy for the treatment of cancer.