Evaluation of in vitro biocompatibility of human pulp stem cells with allogeneic, alloplastic, and xenogeneic grafts under the influence of extracellular vesicles.

Therapies using dental pulp stem cells (DPSCs) or stem cell-derived extracellular vesicles (EVs) have shown promising applications for bone tissue engineering. This in vitro experiment evaluated the joint osteogenic capability of DPSCs and EVs on alloplastic (maxresorp), allogeneic (maxgraft), and xenogeneic (cerabone) bone grafts. We hypothesize that osteogenic differentiation and the proliferation of human DPSCs vary between bone grafts and are favorable under the influence of EVs. DPSCs were obtained from human wisdom teeth, and EVs derived from DPSCs were isolated from cell culture medium. DPSCs were seeded on alloplastic, allogeneic, and xenogeneic bone graft substitutes for control, and the same scaffolds were administered with EVs in further groups. The cellular uptake of EVs into DPSC cells was assessed by confocal laser scanning microscopy. Cell vitality staining and calcein acetoxymethyl ester staining were used to evaluate cell attachment and proliferation. Cell morphology was determined using scanning electron microscopy, and osteogenic differentiation was explored by alkaline phosphatase and Alizarin red staining. Within the limitations of an in vitro study without pathologies, the results suggest that especially the use of xenogeneic bone graft substitutes with DPSCS and EVs may represent a promising treatment approach for alveolar bone defects.

Adherence to the transfer recommendations of the German Trauma Society in severely injured children: a retrospective study from the TraumaRegister DGU.

Particularly for pediatric trauma patients, it is of utmost importance that the right patient be treated in the right place at the right time. While unnecessary interhospital transfers must be avoided, the decision against transfer should not lead to higher complication rates in trauma centers without added pediatric qualifications. We therefore identified independent predictive factors for an early transfer of severely injured patients and compared these factors with the current transfer recommendations of the German Trauma Society. Additionally, the quality of the self-assessment based on the mortality of children who were not transferred was evaluated. A national dataset from the TraumaRegister DGU® was used to retrospectively identify factors for an early interhospital transfer (< 48 h) to a superordinate trauma center. Severely injured pediatric patients (age < 16 years) admitted between 2010 and 2019 were included in this analysis. Adjusted odds ratios (OR) with 95% confidence intervals (CI) for early transfer were calculated from a multivariable model. Prognostic factors for hospital mortality in non-transferred patients were also analyzed. In total, 6069 severely injured children were included. Of these, 65.2% were admitted to a Level I trauma center, whereas 27.7% and 7.1% were admitted to Level II and III centers, respectively. After the initial evaluation in the emergency department, 25.5% and 50.1% of children primarily admitted to a Level II or III trauma center, respectively, were transferred early. Statistically significant predictors of an early transfer were: Serious traumatic brain injury (OR 1.76, 95% CI 1.28-2.43), Injury severity score (ISS) ≥ 16 points (ISS 16-24: OR 2.06, 95% CI 1.59-2.66; ISS 25-33: OR 3.0, 95% CI 2.08-4.31; ISS 34-75: OR 5.42, 95% CI 3.0-9.81, reference category: ISS 9-15), age < 10 years (age 0-1: OR 1.91, 95% CI 1.34-2.71; age 2-5: 2.04, 95% CI 1.50-2.78; age 6-9: 1.62, 95% CI 1.23-2.14; reference category: age 10-15). The most important independent factor for mortality in non-transferred patients was age < 10 years (age 0-1: 5.35, 95% CI 3.25-8.81; age 2-5: 2.46, 95% CI 1.50-4.04; age 6-9: OR 1.7, 95% CI 1.05-2.75; reference category: age 10-15). Knowing the independent predictors for an early transfer, such as a young patient's age, a high injury severity, serious traumatic brain injury (TBI), may improve the choice of the appropriate trauma center. This may guide the rapid decision for an early interhospital transfer. There is still a lack of outcome data on children with early interhospital transfers in Germany, who are the most vulnerable group.

In vitro comparison of the osteogenic capability of human pulp stem cells on alloplastic, allogeneic, and xenogeneic bone scaffolds.

BACKGROUND: A rigorous search for alternatives to autogenous bone grafts to avoid invasiveness at the donor site in the treatment of maxillomandibular bone defects. Researchers have used alloplastic, allogeneic, and xenogeneic bone graft substitutes in clinical studies with varying degrees of success, although their in vitro effects on stem cells remain unclear. Dental pulp stem cells (DPSCs) can potentially enhance the bone regeneration of bone graft substitutes. The present in vitro study investigates the osteogenic capability of DPSCs on alloplastic (biphasic calcium phosphate [BCP]), allogeneic (freeze-dried bone allografts [FDBAs]), and xenogeneic (deproteinized bovine bone mineral [DBBM]) bone grafts. METHODS: Human DPSCs were seeded on 0.5 mg/ml, 1 mg/ml, and 2 mg/ml of BCP, FDBA, and DBBM to evaluate the optimal cell growth and cytotoxicity. Scaffolds and cell morphologies were analyzed by scanning electron microscopy (SEM). Calcein AM and cytoskeleton staining were performed to determine cell attachment and proliferation. Alkaline phosphatase (ALP) and osteogenesis-related genes expressions was used to investigate initial osteogenic differentiation. RESULTS: Cytotoxicity assays showed that most viable DPSCs were present at a scaffold concentration of 0.5 mg/ml. The DPSCs on the DBBM scaffold demonstrated a significantly higher proliferation rate of 214.25 ± 16.17 (p < 0.001) cells, enhancing ALP activity level and upregulating of osteogenesis-related genes compared with other two scaffolds. CONCLUSION: DBBP scaffold led to extremely high cell viability, but also promoted proliferation, attachment, and enhanced the osteogenic differentiation capacity of DPSCs, which hold great potential for bone regeneration treatment; however, further studies are necessary.

Local YB-1, Epo, and EpoR concentrations in fractured bones: results from a porcine model of multiple trauma.

Little is known about the impact of multiple trauma (MT)-related systemic hypoxia on osseous protein concentration of the hypoxia transcriptome. To shed light on this issue, we investigated erythropoietin (Epo), erythropoietin receptor (EpoR), and Y-box binding protein 1 (YB-1) concentrations in the fracture zone in a porcine MT + traumatic hemorrhage (TH) model. Sixteen male domestic pigs were randomized into two groups: an MT + TH group and a sham group. A tibia fracture, lung contusion, and TH were induced in the MT + TH group. The total observation period was 72 h. YB-1 concentrations in bone marrow (BM) were significantly lower in the fracture zone of the MT + TH animals than in the sham animals. Significant downregulation of BM-localized EpoR concentration in both unfractured and fractured bones was observed in the MT + TH animals relative to the sham animals. In BM, Epo concentrations were higher in the fracture zone of the MT + TH animals compared with that in the sham animals. Significantly higher Epo concentrations were detected in the BM of fractured bone compared to that in cortical bone. Our results provide the first evidence that MT + TH alters hypoxia-related protein concentrations. The impacts of both the fracture and concomitant injuries on protein concentrations need to be studied in more detail to shed light on the hypoxia transcriptome in fractured and healthy bones after MT + TH.

Predictors for wound healing complications and prolonged hospital stay in patients with isolated calcaneal fractures.

PURPOSE: Surgically treated calcaneal fractures have a high risk of postoperative wound healing complications and a prolonged length of hospital stay (LOS). The aim of this study was to identify predictor variables of impaired wound healing (IWH) and LOS in surgically treated patients with isolated calcaneal fractures. METHODS: This retrospective cohort study analyzed data on patients aged 18 years or older who were admitted to a level I trauma center with isolated calcaneal fractures between 2008 and 2018. Multivariable regression models were used to identify predictor variables. RESULTS: In total, 89 patients (age: 45.4 years; SD: 15.1) were included. In 68 of these patients, low-profile locking plate osteosynthesis was performed, and a minimally invasive approach (MIA) (percutaneous single screws/K-wire or low-profile locking plating via a sinus tarsi approach) was applied in 21 patients. Multivariable regression analysis revealed that a higher preoperative Böhler's angle (ß = - 0.16 days/degree, 95% CI [- 0.25, - 0.08], p = 0.004) and MIA (ß = - 5.04 days, 95% CI [- 8.52, - 1.56], p = 0.002) reduced the LOS. A longer time-to-surgery (ß = 1.04 days/days, 95% CI [0.66, 1.42] p = 0.001) and IWH increased the LOS (ß = 7.80 days, 95% CI [4.48, 11.12], p = 0.008). In a subsequent multivariable regression analysis, two variables, open fractures (OR: 14.6, 95% CI [1.19, 180.2], p = 0.030) and overweight (BMI > 24) (OR: 3.65, 95% CI [1.11, 12.00], p = 0.019), increased the risk of IWH. CONCLUSION: Advanced treatment algorithms for open fractures are needed to reduce the risk of IWH.

Alterations of Phagocytic Activity and Capacity in Granulocytes and Monocytes Depend on the Pathogen Strain in Porcine Polytrauma.

Background: Polytraumatized patients undergo a strong immunological stress upon insult. Phagocytes (granulocytes and monocytes) play a substantial role in immunological defense against bacteria, fungi and yeast, and in the clearance of cellular debris after tissue injury. We have reported a reduced monocytes phagocytic activity early after porcine polytrauma before. However, it is unknown if both phagocyte types undergo those functional alterations, and if there is a pathogen-specific phagocytic behavior. We characterized the phagocytic activity and capacity of granulocytes and monocytes after polytrauma. Methods: Eight pigs (Sus scrofa) underwent polytrauma consisting of lung contusion, liver laceration, tibial fracture and hemorrhagic shock with fluid resuscitation and fracture fixation with external fixator. Intensive care treatment including mechanical ventilation for 72 h followed. Phagocytic activity and capacity were investigated using an in vitro ex vivo whole blood stimulation phagocytosis assays before trauma, after surgery, 24, 48, and 72 h after trauma. Blood samples were stimulated with Phorbol-12-myristate-13-acetate and incubated with FITC-labeled E. coli, S. aureus or S. cerevisiae for phagocytosis assessment by flow cytometry. Results: Early polytrauma-induced significant increase of granulocytes and monocytes declined to baseline values within 24 h. Percentage of E. coli-phagocytizing granulocytes significantly decreased after polytrauma and during further intensive care treatment, while their capacity significantly increased. Interestingly, both granulocytic phagocytic activity and capacity of S. aureus significantly decreased after trauma, although a recovery was observed after 24 h and yet was followed by another decrease. The percentage of S. cerevisiae-phagocytizing granulocytes significantly increased after 24 h, while their impaired capacity after surgery and 72 h later was detected. Monocytic E. coli-phagocytizing percentage did not change, while their capacity increased after 24-72 h. After a significant decrease in S. aureus-phagocytizing monocytes after surgery, a significant increase after 24 and 48 h was observed without capacity alterations. No significant changes in S. cerevisiae-phagocytizing monocytes occurred, but their capacity dropped 48 and 72 h. Conclusion: Phagocytic activity and capacity of granulocytes and monocytes follow a different pattern and significantly change within 72 h after polytrauma. Both phagocytic activity and capacity show significantly different alterations depending on the pathogen strain, thus potentially indicating at certain and possibly more relevant infection causes after polytrauma.

Helicopter Emergency Medical Service and Hospital Treatment Levels Affect Survival in Pediatric Trauma Patients.

(1) Background: Data on the effects of helicopter emergency medical service (HEMS) transport and treatment on the survival of severely injured pediatric patients in high-level trauma centers remain unclear. (2) Methods: A national dataset from the TraumaRegister DGU® was used to retrospectively compare the mortality rates among severely injured pediatric patients (1-15 years) who were transported by HEMS to those transported by ground emergency medical service (GEMS) and treated at trauma centers of different treatment levels (levels I-III). (3) Results: In total, 2755 pediatric trauma patients (age: 9.0 ± 4.8 years) were included in this study over five years. Transportation by HEMS resulted in a significant survival benefit compared to GEMS (odds ratio (OR) 0.489; 95% confidence interval (CI): 0.282-0.850). Pediatric trauma patients treated in level II or III trauma centers showed 34% and fourfold higher in-hospital mortality risk than those in level I trauma centers (level II: OR 1.34, 95% CI: 0.70-2.56; level III: OR 4.63, 95% CI: 1.33-16.09). (4) Conclusions: In our national pediatric trauma cohort, both HEMS transportation and treatment in level I trauma centers were independent factors of improved survival in pediatric trauma patients.

Fracture fixation strategy and specific muscle tissue availability of neutrophilic granulocytes following mono- and polytrauma: intramedullary nailing vs. external fixation of femoral fractures.

BACKGROUND: In the stabilization of femoral fractures in mono- and polytrauma, clinical practice has shown better care through intramedullary nailing. However, the reason why this is the case is not fully understood. In addition to concomitant injuries, the immunological aspect is increasingly coming to the fore. Neutrophil granulocytes (PMNL), in particular next to other immunological cell types, seem to be associated with the fracture healing processes. For this reason, the early phase after fracture (up to 72 h after trauma) near the fracture zone in muscle tissue was investigated in a pig model. MATERIAL AND METHODS: A mono- and polytrauma pig model (sole femur fracture or blunt thoracic trauma, hemorrhagic shock, liver laceration, and femur fracture) was used to demonstrate the immunological situation through muscle biopsies and their analysis by histology and qRT-PCR during a 72 h follow-up phase. Two stabilization methods were used (intramedullary nail vs. external fixator) and compared with a nontraumatized sham group. RESULTS: Monotrauma shows higher PMNL numbers in muscle tissue compared with polytrauma (15.52 ± 5.39 mono vs. 8.23 ± 3.36 poly; p = 0.013), regardless of the treatment strategy. In contrast, polytrauma shows a longer lasting invasion of PMNL (24 h vs. 72 h). At 24 h in the case of monotrauma, the fracture treated with external fixation shows more PMNL than the fracture treated with intramedullary nailing (p = 0.026). This difference cannot be determined in polytrauma probably caused by a generalized immune response. Both monotrauma and polytrauma show a delayed PMNL increase in the muscle tissue of the uninjured side. The use of intramedullary nailing in monotrauma resulted in a significant increase in IL-6 (2 h after trauma) and IL-8 (24 and 48 h after trauma) transcription. CONCLUSION: The reduction of PMNL invasion into the nearby muscle tissue of a monotrauma femur fracture stabilized by intramedullary nailing supports the advantages found in everyday clinical practice and therefore underlines the usage of nailing. For the polytrauma situation, the fixation seems to play a minor role, possibly due to a generalized immune reaction.

Hematological and Chemical Profiles in a Porcine Model of Severe Multiple Trauma.

BACKGROUND: Clinical chemistry and hematological tests are widely used to monitor the clinical course of several diseases. However, these parameters are sparse in large-animal models of multiple trauma (MT). Thus, we aimed to provide these missing data to improve future experimental setups in trauma research. METHODS: Male pigs (German Landrace pigs) were randomized into either an MT group (n = 8) including blunt thoracic trauma, tibial fracture, and controlled hemorrhage or a sham group (n = 8) without any trauma. After trauma induction, all animals received intensive care treatment for 72 h under anesthesia, including mechanical ventilation and volume resuscitation. Blood and urine samples were obtained to measure common hematological and chemical parameters before trauma (0 h), after trauma (1.5 h), during resuscitation (2.5 h), after fracture stabilization (3.5 h), and at 12, 24, 48, and 72 h. Statistical analyses were performed using a linear mixed model (group × time) and Welch's ANOVA. RESULTS: MT led to a perceptible immunological reaction. Between groups, significantly different time courses of leukocyte counts (p = 0.034) and lymphocyte proportions (p = 0.001) were observed. Moreover, MT changed the time course of total protein (p = 0.006). Significantly lower concentrations compared to sham were found in MT at each single time point starting at 1.5 h to the end of the observation period (all p < 0.05). CONCLUSIONS: Our results indicate that a traumatic insult leads to significant alterations in the immune system already shortly after trauma. Together with the additional catabolic reactions observed, these alterations might contribute to the occurrence of later complications. The presented data provide valid references for further experimental setups with prolonged observation times, especially in similar porcine models of MT.

Surgical treatment strategies in pediatric trauma patients: ETC vs. DCO-an analysis of 316 pediatric trauma patients from the TraumaRegister DGU®.

PURPOSE: External fixation within the damage control concept in unstable multiple trauma patients is widely accepted. Literature about its usage in the pediatric trauma population, however, is rare. The aim of the present study was to elucidate the factors associated with the application of external fixation in the severely injured child. METHODS: Patients with severe trauma aged 0-54 years documented in the TraumaRegister DGU® were included in this study. Demographic data, pattern of injury, injury severity, use of the damage control orthopedics (DCO) or early total care (ETC) concept, duration of mechanical ventilation, intensive care stay, and total hospital stay as well as the occurrence of complications and mortality were evaluated. Statistical evaluation was performed using SPSS (Version 21.0.0) using Chi square tests and linear regression models. RESULTS: While injury severity was comparable between children and adults, type of accident and injury patterns showed significant differences, Overall, the majority of surgical fracture stabilization in AISExtremity ≥ 3 injuries followed the DCO concept in adults (60.3%) and the ETC protocol in children (49.4%). Conservative treatment was chosen for only 11.6% of all children and 9.6% of all adults. An increasing injury severity, AISExtremity ≥ 3 and AISExtremity ≥ 3 in ≥ 2 body regions, and a more advanced age were found to be independent factors in the use of the DCO concept in children. CONCLUSION: Use of external fixation increases with age and plays a minor role in the very young trauma population. However, this does not produce a difference in outcome between children and adults.

Loss of cadherin related family member 5 (CDHR5) expression in clear cell renal cell carcinoma is a prognostic marker of disease progression.

Reduced expression of Cadherin-Related Family Member 5 (CDHR5) was recently found implied in carcinogenesis of colon cancer, but its role in other tumors is unknown. We aimed to analyze the expression of CDHR5 in different subtypes of renal cell carcinoma. CDHR5 expression was immunohistochemically examined using tissue micro arrays (TMAs) covering 279 patients with primary renal cell carcinoma. Additionally, expression data from the TCGA (The Cancer Genome Atlas) of an independent cohort of 489 clear-cell RCC cases was evaluated. CDHR5 protein expression was found in 74.9% of cases, with higher levels seen in clear cell and papillary RCC. In the univariate analysis CDHR5 expression was significantly associated with a longer overall survival of RCC patients at the protein (p = 0.026, HR = 0.56) and transcript levels (TCGA-cohort: p = 0.0002, HR = 0.55). Importantly, differences in survival times were confirmed independently in multivariate analyses in a model with common clinicopathological variables at the transcript level (p = 0.0097, HR = 0.65). Investigation of the putative functional role of CDHR5 using TCGA data and Enrichment analysis for Gene Ontology and Pathways revealed associations with many metabolic and some tumor growth-associated processes and pathways. CDHR5 expression appears to be a promising and new independent prognostic biomarker in renal cell carcinoma.