Zwischen Heizungskeller und Hörsaal. Die Pathologische Sammlung der Universität Erlangen-Nürnberg und das Lehrprojekt "Hands on"

Die Pathologische Sammlung der Universität Erlangen-Nürnberg verfügt heute noch über etwa 1.300 historische Feuchtpräparate, von denen die meisten über 100 Jahre alt sind. Seit den 1960er-Jahren verlor die ehemals sehr umfangreiche Sammlung aufgrund moderner Medien und Methoden ihre Bedeutung als Anschauungsmaterial für die Lehre. Erst in den letzten Jahren wurden ihre Bestände wieder entdeckt und im Rahmen des von der Stiftung Mercator geförderten Projekts "Hands on" gewissermaßen "wiederbelebt". Angesichts sinkender Autopsiezahlen bieten sie die Möglichkeit, Studierende der Medizin weiterhin am dreidimensionalen Objekt auszubilden. Um für die Rückkehr der Dinge in den Hörsaal zu sorgen, wurden zunächst ausgesuchte Teile des Sammlungsbestandes im Rahmen eines Wahlpflichtfaches aufgearbeitet, um sie dann in einem weiteren Schritt in die curriculare Lehre zu integrieren. Auf diese Weise konnte das Projekt zugleich zum Erhalt der lange vergessenen und darüber teils bedrohten Bestände beitragen. Die Sammlung diente den Studierenden darüber hinaus als Instrument der forschenden Erkundung, insofern die in ihr verwahrten Präparate nicht nur aus pathologischer, sondern auch aus historischer Sicht betrachtet und befundet wurden. Der Beitrag möchte den Verlauf des Lehrprojektes noch einmal nachzeichnen, auf die Umsetzung und dabei gemachten Erfahrungen eingehen sowie abschließend einen Blick auf die Auswirkungen und Nebeneffekte des Projekts werfen

Foam-free Production of Surfactin via Anerobic Fermentation of Bacillus subtilis DSM 10T

Surfactin is one of the most popular biosurfactants due to its numerous potential applications. The usually aerobic production via fermentation of Bacillus subtilis is accompanied by vigorous foaming which leads to complex constructions and great expense. Therefore it is reasonable to search for alternative foam-free production processes. The current study introduces a novel approach to produce Surfactin in a foam-free process applying a strictly anaerobic bioreactor cultivation. The process was performed several times with different glucose concentrations in mineral salt medium. The fermentations were analyzed regarding specific (qSurfactin, vol. qSurfactin) and overall product yields (YP/X, YP/S) as well as substrate utilization (YX/S). Fermentations in which 2.5 g/L glucose were employed proofed to be the most effective, reaching product yields of YP/X = 0.278 g/g. Most interesting, the product yields exceeded classical aerobic fermentations, in which foam fractionation was applied. Additionally, values for specific production rate qSurfactin (0.005 g/(g∙h)) and product yield per consumed substrate (YP/S = 0.033 g/g) surpass results of comparable foam-free processes. The current study introduces an alternative to produce a biosurfactant that overcomes the challenges of severe foaming and need for additional constructions. © 2015, Willenbacher et al.; licensee Springer

Endometriosis and Isthmocele: Common or Rare?

Higher cesarean section rates and better ultrasound diagnostics have led to a more frequent diagnosis of isthmocele, a cesarean scar defect. Sometimes, endometriosis is found in the isthmocele, but simultaneous extrauterine endometriosis and endometriosis in the isthmocele have not yet been reported. Additionally, the surgical technique to repair the isthmocele is the subject of ongoing controversy. The aim of this study is to analyze a possible correlation between uterine scar (isthmocele) endometriosis and extrauterine endometriosis and to investigate the outcome of laparoscopic isthmocele resection in the rendezvous technique. In this single-center retrospective study, we included 83 women of reproductive age with symptomatic isthmocele undergoing laparoscopic isthmocele repair in rendezvous technique from 2004 to 2020 at the University of Bern. We collected data on patient and surgical characteristics as well as on postoperative outcomes (symptoms, further pregnancy, and pregnancy outcomes) retrospectively. We analyzed and compared these data for patients with and without endometriosis. Endometriosis was diagnosed during surgery in 22 out of 83 operated patients (26.5%). Diagnosis of isthmocele endometriosis (n = 9, 11%) was significantly higher in patients with extrauterine endometriosis (n = 6, p = 0.004). While the duration of surgery was significantly longer for patients with endometriosis (p = 0.006), the groups did not differ with regard to blood loss or complications. In addition, both groups showed similar indications for isthmocele repair (infertility, abnormal uterine bleeding, or dysmenorrhea). Surgery significantly improved abnormal uterine bleeding (χ2 p < 0.001), dysmenorrhea (χ2, p = 0.03), and infertility (χ2, p < 0.001). Regardless of the presence of endometriosis, 25 of 40 (63%) infertile patients became pregnant after surgery. In one out of eight pregnancies, however, we observed scar complications during pregnancy such as uterine scar pregnancy (n = 3), uterine scar dehiscence (n = 3), and placenta previa (n = 1). Endometriosis is a non-negligible intraoperative finding in patients with symptomatic isthmocele. The laparoscopic approach in the rendezvous technique is safe and effective. Therefore, this method should be recommended, especially in women with secondary infertility, and preoperatively simultaneous endometriosis resection should be discussed with the patient. In follow-up, postoperative pregnancies have to be monitored with care

Real-life data from standardized preanalytical coding (SPREC) in tissue biobanking and its dual use for sample characterization and process optimization.

The standardized preanalytical code (SPREC) aggregates warm ischemia (WIT), cold ischemia (CIT), and fixation times (FIT) in a precise format. Despite its growing importance underpinned by the European in vitro diagnostics regulation or broad preanalytical programs by the National Institutes of Health, little is known about its empirical occurrence in biobanked surgical specimen. In several steps, the Tissue Bank Bern achieved a fully informative SPREC code with insights from 10,555 CIT, 4,740 WIT, and 3,121 FIT values. During process optimization according to LEAN six sigma principles, we identified a dual role of the SPREC code as a sample characteristic and a traceable process parameter. With this preanalytical study, we outlined real-life data in a variety of organs with specific differences in WIT, CIT, and FIT values. Furthermore, our FIT data indicate the potential to adapt the SPREC fixation toward concrete paraffin-embedding time points and to extend its categories beyond 72 h due to weekend delays. Additionally, we identified dependencies of preanalytical variables from workload, daytime, and clinics that were actionable with LEAN process management. Thus, streamlined biobanking workflows during the day were significantly resilient to workload peaks, diminishing the turnaround times of native tissue processing (i.e. CIT) from 74.6 to 46.1 min under heavily stressed conditions. In conclusion, there are surgery-specific preanalytics that are surgico-pathologically limited even under process optimization, which might affect biomarker transfer from one entity to another. Beyond sample characteristics, SPREC coding is highly beneficial for tissue banks and Institutes of Pathology to track WIT, CIT, and FIT for process optimization and monitoring measurements

Brown bowel syndrome: A rare complication in diseases associated with long-standing malabsorption

BACKGROUND/AIMS Longtime chronic malabsorption may among other things cause a lack of liposoluble vitamins. Vitamin E deficiency can lead to formation of lipofuscin aggregates. Its deficiency is also associated with an increased lipofuscinosis of the bowel, i.e. brown bowel syndrome. METHODS Systematic research via Medline on brown bowel syndrome, lipofuscinosis, and vitamin E deficiency was performed. We combined our own clinical experience and a review of the literature for this paper. Its goal is to inform about the possible consequences of severe malabsorption and brown bowel syndrome. RESULTS Systematic data about the occurrence of severe malabsorption and brown bowel syndrome are rare. Only about 27 scientific reports can be found on this subject. Brown bowel syndrome is found mostly in conjunction with vitamin E deficiency and lipofuscinosis of the bowel. The clinical findings are caused by both malabsorption and lipofuscinosis. Case reports show a therapeutic effect of vitamin E. CONCLUSION Vitamin deficiency caused by longtime chronic malabsorption can lead to the development of brown bowel syndrome, which is seen as the expression of lipofuscinosis of the bowel, and can cause further clinical disorders. Patients with malabsorption should therefore be monitored regarding their vitamin E levels

Pathological processing of sentinel lymph nodes in endometrial carcinoma - routine aspects of grossing, ultra-staging, and surgico-pathological parameters in a series of 833 lymph nodes.

Sentinel lymph nodes are widely accepted in the treatment of endometrial carcinoma. Whereas surgical aspects are well studied, the pathological work-up in terms of grossing, frozen section, and the so-called ultra-staging is still a matter of debate. This results in conflicting national or center-based recommendations. In a series of consecutive 833 sentinel lymph nodes from 206 patients in endometrial carcinomas, we compared three different grossing techniques and the use of frozen section in terms of anatomy, detection rates, and survival. In total, 42 macro-metastases, 6 micro-metastases, and 25 nodes with isolated tumor cells were found. Lymph nodes affected at least with micro-metastasis were about 0.5cm enlarged. Detection rates in lamellation technique increased with a step of 5.9% to 8.3% in comparison to bi-valved or complete embedding. The lamellation technique presented with a slight beneficial prognosis in pN0 subgroup (OS, p=0.05), which besides size effects might be attributed to trimming loss. In frozen section, this effect was less pronounced than expected (OS, p=0.56). Ultra-staging only revealed additional micro-metastases and isolated tumor cells. Exclusively, macro-metastases showed poor survival (p<0.001). In multivariate analysis, T-stage, subtype, and lympho-vascular invasion status outperformed this staging parameter significantly. Grossing of sentinel lymph nodes is the most essential step with evidence to prefer lamellation in 2 mm steps. Step sectioning should consider widely spaced protocols to exclude macro-metastases. Frozen sections might add value to the intra-operative assessment of endometrial carcinoma in selected cases. The excellent biological behavior of cases with isolated tumor cells might question the routine application of pan-cytokeratin as ultra-staging method

Thymoquinone-induced conformational changes of PAK1 interrupt prosurvival MEK-ERK signaling in colorectal cancer

Background Thymoquinone (TQ) was shown to reduce tumor growth in several cancer models both in vitro and in vivo. So far only a few targets of TQ, including protein kinases have been identified. Considering that kinases are promising candidates for targeted anticancer therapy, we studied the complex kinase network regulated by TQ. Methods Novel kinase targets influenced by TQ were revealed by in silico analysis of peptide array data obtained from TQ-treated HCT116wt cells. Western blotting and kinase activity assays were used to determine changes in kinase expression patterns in colorectal cancer cells (HCT116wt, DLD-1, HT29). To study the viability/apoptotic effects of combining the PAK1 inhibitor IPA-3 and TQ, crystal violet assay and AnnexinV/PI staining were employed. Interactions between PAK1 and ERK1/2 were investigated by co-immunoprecipitation and modeled by docking studies. Transfection with different PAK1 mutants unraveled the role of TQ-induced changes in PAK1 phosphorylation and TQ´s effects on PAK1 scaffold function. Results Of the 104 proteins identified, 50 were upregulated ≥2 fold by TQ and included molecules in the AKT-MEK-ERK1/2 pathway. Oncogenic PAK1 emerged as an interesting TQ target. Time-dependent changes in two PAK1 phosphorylation sites generated a specific kinase profile with early increase in pPAKThr212 followed by late increase in pPAKThr423. TQ induced an increase of pERK1/2 and triggered the early formation of an ERK1/2-PAK1 complex. Modeling confirmed that TQ binds in the vicinity of Thr212 accompanied by conformational changes in ERK2-PAK1 binding. Transfecting the cells with the non-phosphorylatable mutant T212A revealed an increase of pPAKThr423 and enhanced apoptosis. Likewise, an increase in apoptosis was observed in cells transfected with both the kinase-dead K299R mutant and PAK1 siRNA. Using structural modeling we suggest that TQ interferes also with the kinase domain consequently disturbing its interaction with pPAKThr423, finally inhibiting MEK-ERK1/2 signaling and disrupting its prosurvival function. pERK1/2 loss was also validated in vivo. Conclusions Our study shows for the first time that the small molecule TQ directly binds to PAK1 changing its conformation and scaffold function. Because TQ affects the central RAF/MEK/ERK1/2 pathway, the combination of TQ with targeted therapies is worth considering for future anticancer treatments

Identification of Predictive Markers for Response to Neoadjuvant Chemoradiation in Rectal Carcinomas by Proteomic Isotope Coded Protein Label (ICPL) Analysis

Neoadjuvant chemoradiation (nCRT) is an established procedure in stage union internationale contre le cancer (UICC) II/III rectal carcinomas. Around 53% of the tumours present with good tumor regression after nCRT, and 8%-15% are complete responders. Reliable selection markers would allow the identification of poor or non-responders prior to therapy. Tumor biopsies were harvested from 20 patients with rectal carcinomas, and stored in liquid nitrogen prior to therapy after obtaining patients’ informed consent (Erlangen-No.3784). Patients received standardized nCRT with 5-Fluoruracil (nCRT I) or 5-Fluoruracil ± Oxaliplatin (nCRT II) according to the CAO/ARO/AIO-04 protocol. After surgery, regression grading (Dworak) of the tumors was performed during histopathological examination of the specimens. Tumors were classified as poor (Dworak 1 + 2) or good (Dworak 3 + 4) responders. Laser capture microdissection (LCM) for tumor enrichment was performed on preoperative biopsies. Differences in expressed proteins between poor and good responders to nCRT I and II were identified by proteomic analysis (Isotope Coded Protein Label, ICPL™) and selected markers were validated by immunohistochemistry. Tumors of 10 patients were classified as histopathologically poor (Dworak 1 or 2) and the other 10 tumor samples as histopathologically good (Dworak 3 or 4) responders to nCRT after surgery. Sufficient material in good quality was harvested for ICPL analysis by LCM from all biopsies. We identified 140 differentially regulated proteins regarding the selection criteria and the response to nCRT. Fourteen of these proteins were synchronously up-regulated at least 1.5-fold after nCRT I or nCRT II (e.g., FLNB, TKT, PKM2, SERINB1, IGHG2). Thirty-five proteins showed a complete reciprocal regulation (up or down) after nCRT I or nCRT II and the rest was regulated either according to nCRT I or II. The protein expression of regulated proteins such as PLEC1, TKT, HADHA and TAGLN was validated successfully by immunohistochemistry. ICPL is a valid method to identify differentially expressed proteins in rectal carcinoma tissue between poor vs. good responders to nCRT. The identified protein markers may act as selection criteria for nCRT in the future, but our preliminary findings must be reproduced and validated in a prospective cohort

Spatial distribution of CD3- and CD8-positive lymphocytes as pretest for POLE wild-type in molecular subgroups of endometrial carcinoma.

INTRODUCTION Over the years, the molecular classification of endometrial carcinoma has evolved significantly. Both POLEmut and MMRdef cases share tumor biological similarities like high tumor mutational burden and induce strong lymphatic reactions. While therefore use case scenarios for pretesting with tumor-infiltrating lymphocytes to replace molecular analysis did not show promising results, such testing may be warranted in cases where an inverse prediction, such as that of POLEwt, is being considered. For that reason we used a spatial digital pathology method to quantitatively examine CD3+ and CD8+ immune infiltrates in comparison to conventional histopathological parameters, prognostics and as potential pretest before molecular analysis. METHODS We applied a four-color multiplex immunofluorescence assay for pan-cytokeratin, CD3, CD8, and DAPI on 252 endometrial carcinomas as testing and compared it to further 213 cases as validation cohort from a similar multiplexing assay. We quantitatively assessed immune infiltrates in microscopic distances within the carcinoma, in a close distance of 50 microns, and in more distant areas. RESULTS Regarding prognostics, high CD3+ and CD8+ densities in intra-tumoral and close subregions pointed toward a favorable outcome. However, TCGA subtyping outperforms prognostication of CD3 and CD8 based parameters. Different CD3+ and CD8+ densities were significantly associated with the TCGA subgroups, but not consistently for histopathological parameter. In the testing cohort, intra-tumoral densities of less than 50 intra-tumoral CD8+ cells/mm2 were the most suitable parameter to assume a POLEwt, irrespective of an MMRdef, NSMP or p53abn background. An application to the validation cohort corroborates these findings with an overall sensitivity of 95.5%. DISCUSSION Molecular confirmation of POLEmut cases remains the gold standard. Even if CD3+ and CD8+ cell densities appeared less prognostic than TCGA, low intra-tumoral CD8+ values predict a POLE wild-type at substantial percentage rates, but not vice versa. This inverse correlation might be useful to increase pretest probabilities in consecutive POLE testing. Molecular subtyping is currently not conducted in one-third of cases deemed low-risk based on conventional clinical and histopathological parameters. However, this percentage could potentially be increased to two-thirds by excluding sequencing of predicted POLE wild-type cases, which could be determined through precise quantification of intra-tumoral CD8+ cells