Perizyten als Leitstrukturen der interstitiellen Leukozytenmigration bei steriler Inflammation

Diese Arbeit identifiziert NG2+Perizyten als essentielle Strukturen für die interstitielle Migration von myeloiden Leukozyten bei steriler Inflammation in vivo. Sie zeigt außerdem, dass die interstitielle Migration kein rein durch lösliche Chemokine gesteuert Prozess ist. Bis dato wurde weder die Rolle der NG2+ Perizyten bei steriler Inflammation in vivo noch ihr Einfluss auf die interstitielle Leukozytenmigration in vivo untersucht. Es wurde ein Mausmodell verwendet, dass es ermöglicht eine diffuse sterile Inflammation oder eine fokale sterile Nekrose zu induzieren und diese mit Hilfe von 2-Photonen Mikroskopie darzustellen. In diesen Untersuchungen zeigte sich, dass es in vivo bei steriler Inflammation zu Interaktionen, zwischen NG2+ Perizyten und myeloiden Leukozyten kommt. Diese Interaktionen werden durch ICAM-1 vermittelt, welches als Reaktion auf die sterile Inflammation von den NG2+ Perizyten exprimiert wird. Die Expression von ICAM-1 zeigt sich sowohl in vitro als auch in vivo. Bei einer diffusen sterilen Inflammation kommt es zu einer Akkumulation der myeloiden Leukozyten im interstitiellen Gewebe an den kapillären und arteriolären NG2+ Perizyten und zu dynamischen Interaktionen zwischen den Zellen. In der Analyse der dynamischen Interaktionen wird deutlich, dass NG2+ Perizyten sowohl chemotaktisch als auch haptotaktisch auf die myeloiden Leukozyten wirken. Auch bei der fokalen sterilen Inflammation kommt es zu Interaktionen zwischen myeloiden Leukozyten und NG2+ Perizyten, auch wenn diese kürzer sind, da noch ein weiterer Stimulus in Form des Inflammationsfokus vorliegt. Weiterhin wurde deutlich, dass diese Interaktionen vorteilhaft für die interstitielle Migration der myeloiden Leukozyten sind. Sie wurden durch die Interaktion aktiviert und migrierten direkter, schneller und somit wesentlich effektiver. In vivo und in vitro wurde deutlich, dass NG2+ Perizyten bei steriler Inflammation das chemotaktisch wirksame Molekül MIF speichern, sezernieren und oberflächlich präsentieren. In vivo wurde deutlich, dass das von den NG2+ Perizyten freigesetzte MIF essentiell ist für eine effektive und schnelle Navigation der myeloiden Leukozyten zu einer fokalen sterilen Inflammation. NG2+ Perizyten nehmen also eine zentrale Rolle bei der interstitiellen Migration von myeloiden Leukozyten bei steriler Inflammation ein. Diese Arbeit veranschaulicht und definiert die Relevanz der NG2+ Perizyten bei steriler Inflammation. Sie zeigt, dass NG2+ Perizyten aktiv bei der Modulation der Immunantwort als Folge einer sterilen Inflammation partizipieren. Außerdem wurde das Wissen hinsichtlich der Mechanismen und relevanten Faktoren der interstitiellen Migration von myeloiden Leukozyten erweitert.This Thesis identifies NG2+pericytes as essential structures for interstitial leukocyte trafficking during sterile inflammation. It shows that the trafficking is orchestrated by more than just soluble chemokines. A mouse model was established to visualize via 2-Photon microscopy sterile inflammation and induce a focal sterile necrosis in the skin of the ear. The in vivo results show, that there are dynamic interactions between NG2+pericytes and myeloid leukocytes. Those interactions are mediated by ICAM-1 which is expressed and upregulated by NG2+pericytes after sensing a sterile inflammation. A diffuse sterile inflammation induces myeloid leukocytes to accumulate along capillary NG2+pericytes and to interact with them. The analysis of the dynamic interactions between myeloid leukocytes and NG2+pericytes shows that the NG2+pericytes attract the myeloid leukocytes. In addition, there are chemotactic and haptotactic interactions between them. After inducing a focal sterile necrosis there are as well haptotactic and chemotactic interactions between NG2+pericytes and myeloid leukocytes. Though they are much shorter due to the fact that there is an additional local inflammatory stimulus. Furthermore, it showed that these interactions are beneficial for the myeloid leukocyte trafficking. The myeloid leukocytes are activated by the interaction, therefore migrate faster and in a more directional manner, consequently being much more effective. It became clear in vivo and in vitro that during sterile inflammation NG2+pericytes express and secrete MIF, a chemotactic molecule. MIF secreted by NG2+pericytes is required in vivo for the guidance and establishing migratory cues that provide myeloid leukocytes with the ability to effectively reach a focal sterile inflammation in the interstitial tissue. Hence NG2+pericytes are vital for the interstitial myeloide leukocyte trafficking during sterile inflammation

Nodal Disease and Survival in Oral Cancer: Is Occult Metastasis a Burden Factor Compared to Preoperatively Nodal Positive Neck?

Simple Summary Occult metastasis in oral squamous cell carcinoma patients is a feared complication. However, there are barely any existing data on survival of patients suffering from occult metastasis. This study aims to compare patients with oral squamous cell carcinoma, considering survival in occult metastases and different treatment approaches. The impact of neck involvement and occult metastasis (OM) in patients with oral squamous cell carcinoma (OSCC) favors an elective neck dissection. However, there are barely any existing data on survival for patients with OM compared with patients with positive lymph nodes detected preoperatively. This study aims to compare survival curves of patients suffering from lymph nodal metastases in a preoperatively N+ neck with those suffering from OM. In addition, clinical characteristics of the primary tumor were analyzed to predict occult nodal disease. This retrospective cohort study includes patients with an OSCC treated surgically with R0 resection with or without adjuvant chemoradiotherapy between 2010 and 2016. Minimum follow-up was 60 months. Kaplan-Meier analysis was used to compare the survival between patients with and without occult metastases and patients with N+ neck to those with occult metastases. Logistic regression was used to detect potential risk factors for occult metastases. The patient cohort consisted of 226 patients. Occult metastases occurred in 16 of 226 patients. In 53 of 226 patients, neck lymph nodes were described as suspect on CT imaging but had a pN0 neck. Higher tumor grading increased the chance of occurrence of occult metastasis 2.7-fold (OR = 2.68, 95% CI: 1.07-6.7). After 12, 24, 48 and 60 months, 82.3%, 73.8%, 69% and 67% of the N0 patients, respectively, were progression free. In the group with OM occurrence, for the same periods 66.6%, 50%, 33.3% and 33.3% of the patients, respectively, were free of disease. For the same periods, respectively, 81%, 63%, 47% and 43% of the patients in the N+ group but without OM remained disease free. The predictors for progression-free survival were a positive N status (HR = 1.44, 95% CI: 1.08-1.93) and the occurrence of OM (HR = 2.33, 95% CI: 1.17-4.64). The presence of occult metastasis could lead to decreased survival and could be a burdening factor requiring treatment escalation and a more aggressive follow-up than nodal disease detected in the preoperative diagnostic imaging

Digital planning and individual implants for secondary reconstruction of midfacial deformities: A pilot study

Objective To evaluate the feasibility and accuracy of implementing three-dimensional virtual surgical planning (VSP) and subsequent transfer by additive manufactured tools in the secondary reconstruction of residual post-traumatic deformities in the midface. Methods Patients after secondary reconstruction of post-traumatic midfacial deformities were included in this case series. The metrical deviation between the virtually planned and postoperative position of patient-specific implants (PSI) and bone segments was measured at corresponding reference points. Further information collected included demographic data, post-traumatic symptoms, and type of transfer tools. Results Eight consecutive patients were enrolled in the study. In five patients, VSP with subsequent manufacturing of combined predrilling/osteotomy guides and PSI was performed. In three patients, osteotomy guides, repositioning guides, and individually prebent plates were used following VSP. The median distances between the virtually planned and the postoperative position of the PSI were 2.01 mm (n = 18) compared to a median distance concerning the bone segments of 3.05 mm (n = 12). In patients where PSI were used, the median displacement of the bone segments was lower (n = 7, median 2.77 mm) than in the group with prebent plates (n = 5, 3.28 mm). Conclusion This study demonstrated the feasibility of VSP and transfer by additive manufactured tools for the secondary reconstruction of complex residual post-traumatic deformities in the midface. However, the median deviations observed in this case series were unexpectedly high. The use of navigational systems may further improve the level of accuracy

Monocytes, neutrophils, and platelets cooperate to initiate and propagate venous thrombosis in mice in vivo

Deep vein thrombosis (DVT) is a major cause of cardiovascular death. The sequence of events that promote DVT remains obscure, largely as a result of the lack of an appropriate rodent model. We describe a novel mouse model of DVT which reproduces a frequent trigger and resembles the time course, histological features, and clinical presentation of DVT in humans. We demonstrate by intravital two-photon and epifluorescence microscopy that blood monocytes and neutrophils crawling along and adhering to the venous endothelium provide the initiating stimulus for DVT development. Using conditional mutants and bone marrow chimeras, we show that intravascular activation of the extrinsic pathway of coagulation via tissue factor (TF) derived from myeloid leukocytes causes the extensive intraluminal fibrin formation characteristic of DVT. We demonstrate that thrombus-resident neutrophils are indispensable for subsequent DVT propagation by binding factor XII (FXII) and by supporting its activation through the release of neutrophil extracellular traps (NETs). Correspondingly, neutropenia, genetic ablation of FXII, or disintegration of NETs each confers protection against DVT amplification. Platelets associate with innate immune cells via glycoprotein Ibα and contribute to DVT progression by promoting leukocyte recruitment and stimulating neutrophil-dependent coagulation. Hence, we identified a cross talk between monocytes, neutrophils, and platelets responsible for the initiation and amplification of DVT and for inducing its unique clinical features

Frequency of translocation of USP-6 in the aneurysmal bone cyst of the jaw

Background: This study aims to detect USP6 translocation in aneurysmal cysts located in the jaw and to give an overview of demographic data. Methods: The present retrospective cohort study includes 10 patients who underwent surgery due to an aneurysmal cyst of the jaw in our hospital between 2002 and 2021. Unstained formalin-fixed and paraffin-embedded tissue sections cut at 4 mu m thickness were subjected to USP6 FISH testing. Results: All patients underwent surgical treatment. In four of ten patients (40%) USP-6-translocations have been found. Conclusion: Based on the study, it is hypothesized that the aneurysmal bone cyst of the jaw bone may be subject to a different pathomechanism than that of the long bones. Therefore, it seems conceivable that the primary cause of aneurysmal bone cysts in the jaw might differ

Comparative analysis of bone regeneration behavior using recombinant human BMP-2 versus plasmid DNA of BMP-2

Bone regeneration and the osteoinductive capacity of implants are challenging issues in clinical medicine. Currently, recombinant growth factors and nonviral gene transfer are the most frequently investigated methods for bone growth enhancement, although the more favorable method remains unclear. There is a lack of knowledge in literature about the in vivo comparison of these methods for bone regeneration. BMP-2, which is the most commonly used growth factor for osteogenesis, was applied at its most efficient dose as a recombinant growth factor (rhBMP-2) and as a growth-factor-encoding copolymer protected gene vector (pBMP-2) in a critical size bone defect (CSD) model to determine the most suitable method for bone regeneration. CSDs were induced bilaterally in 32 Sprague-Dawley rats. RhBMP-2 (62.5 μg) or pBMP-2 (2.5 μg) was embedded in poly(d,l-)lactide-coated titanium discs. Survival times were set at 14, 28, 56, and 112 days. After euthanasia, samples were analyzed via micro-computed tomography, polychrome sequential fluorescent labeling, and immunohistochemistry. Whereas defects in both groups were bridged with new bone after 56 days, rhBMP-2 initially induced ectopic new bone formation that was later remodeled in an unorganized hypodense manner. In contrast, pBMP-2 led to slower but steady bone regeneration with physiological tissue morphology, as confirmed by high osteoblast activity shown by osteocalcin staining. CD68 and TRAP staining verified high osteoclast activity for the rhBMP-2 group. pBMP-2 successfully induced locally controlled physiological bone regeneration, whereas rhBMP-2 triggered rapid and ectopic but insufficient bone formation. Thus, nonviral gene transfer appears to be more favorable for clinical applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 163-173, 2019

Cancer testis antigen (PRAME) as an independent marker for survival in oral squamous cell carcinoma (OSCC)

Background The objective was to assess the expression patterns of the cancer testis antigen PRAME, NY-ESO1, and SSX2 in oral squamous cell carcinoma (OSSC) and to correlate the expression with clinical and histopathological parameters including progression-free survival analysis. Methods The study variables of this retrospective cohort study (n = 83) included demographic data, histopathological data, and information on progression-free survival. PRAME expression patterns were rated based on immunohistochemistry on tissue microarrays (TMA). The survival rate was assessed by Kaplan-Meier method and Cox regression model. The primary predictor variable was defined as the expression of PRAME and the outcome variable was progression-free survival. Results Analysis of progression-free survival using Kaplan-Meier method showed that patients with positive expression of PRAME had lower probabilities of progression-free survival (p < 0.001). According to the Cox regression model, the level of PRAME expression had a considerable and significant independent influence on progression-free survival (positive PRAME expression increasing the hazards for a negative outcome by 285% in our sample;HR = 3.85, 95% CI: 1.45-10.2, p = 0.007). The expression of SSX2 (n = 1) and NY-ESO-1 (n = 5) in our samples was rare. Conclusion PRAME is expressed in OSCC and appears to be a suitable marker of progression-free survival, correlates with severe course, and may allow identification of high-risk patients with aggressive progression