Elimination of damaged mitochondria during UVB-induced senescence is orchestrated by NIX-dependent mitophagy.

Skin aging is the result of two types of aging, "intrinsic aging" an inevitable consequence of physiologic and genetically determined changes and "extrinsic aging," which is dependent on external factors such as exposure to sunlight, smoking, and dietary habits. UVB causes skin injury through the generation of free radicals and other oxidative byproducts, also contributing to DNA damage. Appearance and accumulation of senescent cells in the skin are considered one of the hallmarks of aging in this tissue. Mitochondria play an important role for the development of cellular senescence, in particular stress-induced senescence of human cells. However, many aspects of mitochondrial physiology relevant to cellular senescence and extrinsic skin aging remain to be unraveled. Here, we demonstrate that mitochondria damaged by UVB irradiation of human dermal fibroblasts (HDF) are eliminated by NIX-dependent mitophagy and that this process is important for cell survival under these conditions. Additionally, UVB-irradiation of human dermal fibroblasts (HDF) induces the shedding of extracellular vesicles (EVs), and this process is significantly enhanced in UVB-irradiated NIX-depleted cells. Our findings establish NIX as the main mitophagy receptor in the process of UVB-induced senescence and suggest the release of EVs as an alternative mechanism of mitochondrial quality control in HDF.

Preadipocytes in human granulation tissue: role in wound healing and response to macrophage polarization.

BACKGROUND: Chronic non-healing wounds pose a global health challenge. Under optimized conditions, skin wounds heal by the formation of scar tissue. However, deregulated cell activation leads to persistent inflammation and the formation of granulation tissue, a type of premature scar tissue without epithelialization. Regenerative cells from the wound periphery contribute to the healing process, but little is known about their cellular fate in an inflammatory, macrophage-dominated wound microenvironment. METHODS: We examined CD45-/CD31-/CD34+ preadipocytes and CD68+ macrophages in human granulation tissue from pressure ulcers (n=6) using immunofluorescence, immunohistochemistry, and flow cytometry. In vitro, we studied macrophage-preadipocyte interactions using primary human adipose-derived stem cells (ASCs) exposed to conditioned medium harvested from IFNG/LPS (M1)- or IL4/IL13 (M2)-activated macrophages. Macrophages were derived from THP1 cells or CD14+ monocytes. In addition to confocal microscopy and flow cytometry, ASCs were analyzed for metabolic (OXPHOS, glycolysis), morphological (cytoskeleton), and mitochondrial (ATP production, membrane potential) changes. Angiogenic properties of ASCs were determined by HUVEC-based angiogenesis assay. Protein and mRNA levels were assessed by immunoblotting and quantitative RT-PCR. RESULTS: CD45-/CD31-/CD34+ preadipocytes were observed with a prevalence of up to 1.5% of total viable cells in human granulation tissue. Immunofluorescence staining suggested a spatial proximity of these cells to CD68+ macrophages in vivo. In vitro, ASCs exposed to M1, but not to M2 macrophage secretome showed a pro-fibrotic response characterized by stress fiber formation, elevated alpha smooth muscle actin (SMA), and increased expression of integrins ITGA5 and ITGAV. Macrophage-secreted IL1B and TGFB1 mediated this response via the PI3K/AKT and p38-MAPK pathways. In addition, ASCs exposed to M1-inflammatory stress demonstrated reduced migration, switched to a glycolysis-dominated metabolism with reduced ATP production, and increased levels of inflammatory cytokines such as IL1B, IL8, and MCP1. Notably, M1 but not M2 macrophages enhanced the angiogenic potential of ASCs. CONCLUSION: Preadipocyte fate in wound tissue is influenced by macrophage polarization. Pro-inflammatory M1 macrophages induce a pro-fibrotic response in ASCs through IL1B and TGFB1 signaling, while anti-inflammatory M2 macrophages have limited effects. These findings shed light on cellular interactions in chronic wounds and provide important information for the potential therapeutic use of ASCs in human wound healing.

Delayed Reconstruction after Major Head and Neck Cancer Resection: An Interdisciplinary Feasibility Study.

A single immediate reconstruction with free tissue transfer is the method of choice after major head and neck cancer (HNC) resection, but this is frequently associated with long operating hours. Considering regulatory working hour constraints, we investigated whether a two-staged reconstructive approach with temporary defect coverage by an artificial tissue substitute would be feasible. HNC patients underwent either immediate or delayed reconstruction after tumor resection. Patients with delayed reconstruction received preliminary reconstruction with an artificial tissue substitute followed by definitive microvascular reconstruction in a separate, second procedure. Of the 33 HNC patients, 13 received delayed reconstruction and 20 received immediate reconstruction. Total anesthesia time (714 vs. 1011 min; p < 0.002) and the total duration of hospital stay (34 ± 13 vs. 25 ± 6 days; p = 0.03) were longer in the delayed reconstruction group. Perioperative morbidity (p = 0.58), functional outcome (p > 0.1) and 5-year postoperative survival rank (p = 0.28) were comparable in both groups. Delayed reconstruction after HNC resection was feasible. Perioperative morbidity, functional outcome and overall survival were comparable to immediate reconstruction.

Resection of Skin Cancer Resulting in Free Vascularized Tissue Reconstruction: Always a Therapeutic Failure?

The globally increasing incidence of cutaneous malignancies leads, in parallel, to increasing numbers of locally advanced skin cancer resulting in reconstructive surgery. Reasons for locally advanced skin cancer may be a patient's neglect or aggressive tumor growth, such as desmoplastic growth or perineural invasion. This study investigates characteristics of cutaneous malignancies requiring microsurgical reconstruction with the aim of identifying possible pitfalls and improving diagnostic and therapeutic processes. A retrospective data analysis from 2015 to 2020 was conducted. Seventeen patients (n = 17) were included. The mean age at reconstructive surgery was 68.5 (±13) years. The majority of patients (14/17, 82%) presented with recurrent skin cancer. The most common histological entity was squamous cell carcinoma (10/17, 59%). All neoplasms showed at least one of the following histopathological characteristics: desmoplastic growth (12/17, 71%), perineural invasion (6/17, 35%), or tumor thickness of at least 6 mm (9/17, 53%). The mean number of surgical resections until cancer-free resection margins (R0) were achieved was 2.4 (±0.7). The local recurrence rate and the rate of distant metastases were 36%. Identified high-risk neoplastic characteristics, such as desmoplastic growth, perineural invasion, and a tumor depth of at least 6 mm, require a more extensive surgical treatment without concerns about defect size.

Single- versus two-stage reconstruction in patients with head and neck cancer: What are the benefits?

In head and neck oncology, surgical treatment frequently results in microvascular reconstruction. Oncologic resection followed by immediate reconstruction is often associated with prolonged working and surgical duration, challenging a surgeon's concentration level and potentially worsening patient outcome. To improve the surgeon's performance and to reduce risk of potential complications, we implemented a two-stage procedure in patients with head and neck cancer. This study critically analyzed the surgical outcomes, organizational benefits, and investigated job satisfaction among affected health care professionals. A retrospective data analysis of patients who had undergone microvascular reconstruction after oncologic head and neck surgery between 2010 and 2021 included 33 patients (n = 33). Twenty patients underwent single-stage reconstruction (group 1, n = 20) and 13 patients underwent two-stage reconstruction (group 2, n = 13) with 12.2 (± 7.4) days between surgeries. The mean surgical duration, and mean start and end time of the reconstructive surgery component differed significantly (p = 0.002). The mean total complication rate (p = 0.58) did not differ significantly, although a trend toward higher demands for blood products was observed in group 1. There was no significant difference in five-year survival (p = 0.28). A questionnaire on subjective work performance was answered by the affected health care professionals (n = 34) and it revealed that 88% preferred long surgeries to be scheduled first and that 97% work most efficiently in the morning. In conclusion, two-stage reconstruction is a suitable option in selected head and neck cancer patients offering the possibility of optimizing preoperative planning and organization. This may result in regular working hours, reduced surgeon fatigue, and improved job satisfaction without compromising patient outcomes or survival.

Depletion of growth differentiation factor 15 (GDF15) leads to mitochondrial dysfunction and premature senescence in human dermal fibroblasts.

Growth differentiation factor 15 (GDF15) is a stress-responsive cytokine also known as a mitokine; however, its role in mitochondrial homeostasis and cellular senescence remained elusive. We show here that knocking down GDF15 expression in human dermal fibroblasts induced mitochondrial dysfunction and premature senescence, associated with a distinct senescence-associated secretory phenotype. Fibroblast-specific loss of GDF15 expression in a model of 3D reconstructed human skin induced epidermal thinning, a hallmark of skin aging. Our results suggest GDF15 to play a so far undisclosed role in mitochondrial homeostasis to delay both the onset of cellular senescence and the appearance of age-related changes in a 3D human skin model.

The circadian transcription factor ARNTL2 is regulated by weight-loss interventions in human white adipose tissue and inhibits adipogenesis.

Misalignment of physiological circadian rhythms promotes obesity which is characterized by white adipose tissue (WAT) expansion. Differentiation of Adipose stem/progenitor cells (ASCs) contributes to WAT increase but the importance of the cellular clock in this process is incompletely understood. In the present study, we reveal the role of the circadian transcription factor Aryl hydrocarbon receptor nuclear translocator-like 2 (ARNTL2) in human ASCs, isolated from subcutaneous (s)WAT samples of patients undergoing routine elective plastic abdominal surgery. We show that circadian synchronization by serum-shock or stimulation with adipogenic stimuli leads to a different expression pattern of ARNTL2 relative to its well-studied paralogue ARNTL1. We demonstrate that ARNTL2 mRNA is downregulated in ASCs upon weight-loss (WL) whereas ARNTL2 protein is rapidly induced in the course of adipogenic differentiation and highly abundant in adipocytes. ARNTL2 protein is maintained in ASCs cooperatively by mechanistic Target of Rapamycin (mTOR) and Mitogen-activated Protein Kinase (MAPK) signalling pathways while ARNTL2 functions as an inhibitor on both circuits, leading to a feedback mechanism. Consistently, ectopic overexpression of ARNTL2 repressed adipogenesis by facilitating the degradation of ARNTL1, inhibition of Kruppel-Like Factor 15 (KLF15) gene expression and down-regulation of the MAPK-CCAAT/enhancer-binding protein ß (C/EBPß) axis. Western blot analysis of sWAT samples from normal-weight, obese and WL donors revealed that ARNTL2 protein was solely elevated by WL compared to ARNTL1 which underscores unique functions of both transcription factors. In conclusion, our study reveals ARNTL2 to be a WL-regulated inhibitor of adipogenesis which might provide opportunities to develop strategies to ameliorate obesity.

Dipeptidyl peptidase-4 cell surface expression marks an abundant adipose stem/progenitor cell population with high stemness in human white adipose tissue.

The capacity of adipose stem/progenitor cells (ASCs) to undergo self-renewal and differentiation is crucial for adipose tissue homoeostasis, regeneration and expansion. However, the heterogeneous ASC populations of the adipose lineage constituting adipose tissue are not precisely known. In the present study, we demonstrate that cell surface expression of dipeptidyl peptidase-4 (DPP4)/cluster of differentiation 26 (CD26) subdivides the DLK1-/CD34+/CD45-/CD31- ASC pool of human white adipose tissues (WATs) into two large populations. Ex vivo, DPP4+ ASCs possess higher self-renewal and proliferation capacity and lesser adipocyte differentiation potential than DDP4- ASCs. The knock-down of DPP4 in ASC leads to significantly reduced proliferation and self-renewal capacity, while adipogenic differentiation is increased. Ectopic overexpression of DPP4 strongly inhibits adipogenesis. Moreover, in whole mount stainings of human subcutaneous (s)WAT, we detect DPP4 in CD34+ ASC located in the vascular stroma surrounding small blood vessels and in mature adipocytes. We conclude that DPP4 is a functional marker for an abundant ASC population in human WAT with high proliferation and self-renewal potential and low adipogenic differentiation capacity.

Does the breast reconstruction method have an impact on time delay to adjuvant chemotherapy - A comparison between autologous and expander/implant breast reconstruction.

Introduction: This study aims to analyze whether autologous breast reconstruction as compared to expander/implant reconstruction has a higher risk of postoperative wound healing problems (WHPs) and thus potentially delays chemotherapy start. Methods: Between January 2012 and December 2019, a total of 64 women with NSME/SSME and autologous (Group1, n = 33) or expander/implant reconstruction (Group2, n = 31) and adjuvant chemotherapy were enrolled in this study conducted at Innsbruck Medical University Hospital. Immediate postoperative WHPs in each group were compared, and the time from operation to initiation of chemotherapy was analyzed. If the start of chemotherapy was postponed for more than six weeks postoperatively due to WHP, it was defined as delayed. Statistical analysis was performed with SPSS and Fisher's exact test. Results: More postoperative WHP occurred in Group 1 than in Group 2 (51.6% vs. 9.7%, p < 0.001). Due to WHP, chemotherapy start was delayed for more than six weeks postoperatively in 30.3% of Group 1 patients and 3.2% of Group 2 patients. Only small differences in age (Group 1: 47±1 vs. Group 2: 46±2 years) and BMI (Group 1: 24.3 ± 0.6 vs. Group 2: 23.3 ± 0.7 kg/m2) were found. Conclusion: Our study shows a far smaller risk for postoperative WHP and delay of chemotherapy start in the expander/implant group in comparison with the autologous group. In some selected patients with high urgency for adjuvant chemotherapy, a bridging operation by means of expander reconstruction prior to chemotherapy could be an oncologically safe pathway.

Correction of Temporal Hollowing After Pterional Craniotomy by Autologous Fat Grafting. A Single-Center Experience.

OBJECTIVE: Aesthetic complications following neurosurgical procedures impact patient quality of life and self-perception. Postoperative temporal hollowing frequently is seen after temporal craniotomy, resulting mainly from atrophy of the temporal muscle. Autologous fat grafting is a tailorable method to correct such approach-related sequelae. We herein present our clinical patient series and discuss pearls and pitfalls of this method. METHODS: In this retrospective single-center study, correction of postoperative temporal hollowing using autologous fat grafting was performed in 16 patients. Temporal tissue thickness ratio was measured using magnetic resonance tomography images to visualize the graft. Patients, plastic surgeons, and neurosurgeons evaluated the results independently using the herein presented scale. RESULTS: The mean interval between the neurosurgical procedure and fat grafting was 62 months. A mean volume of 11.5 mL of autologous fat was injected in an average of 2.5 sessions after initial rigottomy. Temporal tissue thickness was significantly augmented at a mean of 2.2 years after the operation (mean 0.71 ± 0.25, range 0.43-1.1; P = 0.0214) as compared with the preoperative finding (mean 0.48 ± 0.1, range 0.32-0.6). Patients were more satisfied with the results than were surgeons, reflecting the significant impact of the deformity on patient self-esteem. CONCLUSIONS: Autologous fat grafting is a valuable method for correcting postoperative temporal hollowing that provides stable results, high patient and surgeon satisfaction, and can be tailored to the patient's individual needs. It should not be considered a merely aesthetic operation but an important rehabilitation step towards restoring the patient's quality of life.

Free Flap Outcome in Irradiated Recipient Sites: A Systematic Review and Meta-analysis.

The impact of previous radiotherapy on free flap outcome is still a subject of debate. Clinical investigations have come to divergent conclusions and the true effect of radiotherapy (XRT) on flap survival is not definitely known. Most studies investigating the factor often have their methodological limitations such as lack of statistical power as a consequence of the overall low failure rates together with few irradiated cases. This study will attempt to address the question whether previous radiotherapy is associated with a significantly higher incidence of flap failure or not. Methods: A systematic review and meta-analysis were conducted in concordance with the PRISMA protocol using the PubMed database. Fixed-effect and random-effect models were applied to obtain the odds ratio of total flap failure and partial flap failure between radiation and nonradiation groups. Statistical heterogeneity and publication bias were assessed and forest plots and funnel plots were constructed for graphic illustration. Results: A total of 43 studies were included for qualitative and quantitative analysis involving 18,776 flaps in 17,532 patients. Patients with preoperative XRT were significantly associated with an increased risk for total (odds ratio fixed = 1.675, 95% confidence interval [CI] = 1.405-1.996, P < 0.001) and partial free flap failure (odds ratio fixed = 2.161, 95% CI = 1.472-2.172, P < 0.001). Conclusion: The study suggests that preoperative radiotherapy is associated with an increased risk for total and partial free flap failure. Further studies are needed to investigate the effect of total XRT dose and time after radiation on free flap outcome.

An organoid model derived from human adipose stem/progenitor cells to study adipose tissue physiology.

We established a functional adipose organoid model system for human adipose stem/progenitor cells (ASCs) isolated from white adipose tissue (WAT). ASCs were forced to self-aggregate by a hanging-drop technique. Afterwards, spheroids were transferred into agar-coated cell culture dishes to avoid plastic-adherence and dis-aggregation. Adipocyte differentiation was induced by an adipogenic hormone cocktail. Morphometric analysis revealed a significant increase in organoid size in the course of adipogenesis until d 18. Whole mount staining of organoids using specific lipophilic dyes showed large multi- and unilocular fat deposits in differentiated cells indicating highly efficient differentiation of ASCs into mature adipocytes. Moreover, we found a strong induction of the expression of key adipogenesis and adipocyte markers (CCAAT/enhancer-binding protein (C/EBP) ß, peroxisome proliferator-activated receptor (PPAR) γ, fatty acid-binding protein 4 (FABP4), adiponectin) during adipose organoid formation. Secreted adiponectin was detected in the cell culture supernatant, underscoring the physiological relevance of mature adipocytes in the organoid model. Moreover, colony formation assays of collagenase-digested organoids revealed the maintenance of a significant fraction of ASCs within newly formed organoids. In conclusion, we provide a reliable and highly efficient WAT organoid model, which enables accurate analysis of cellular and molecular markers of adipogenic differentiation and adipocyte physiology.

A Modified Rhomboid Flap for Medial Canthal Reconstruction.

The reconstruction of medial canthal defects is often challenging in achieving continuity of color and texture, obtaining adequate tissue for large defects, and the reproduction of natural external appearance with inconspicuous scars. We describe a technique for reconstruction of the medial canthal area, using a modified rhomboid flap. METHODS: The technique is based on the use of a modified rhomboid flap for medial canthal defects-superiorly based on the root of the nose for defects mostly above the medial canthal tendon, inferiorly based on the cheek for defects mostly below the medial canthal tendon, and in cases of large defects, using a combination of the two flaps. We present a case series of five patients successfully reconstructed with the mentioned technique after resection of medial canthal basal cell carcinoma. RESULTS: Of the five patients with a mean age of 76.2 years (range 62-84 years), reconstruction was performed in three patients with a superiorly based rhomboid flap, in one patient with an inferiorly based rhomboid flap, and in another patient with a large defect using a combination of the two flaps. Mean follow-up was 374.4 days (range 30-1247 days). All patients achieved a complete primary closure with no further surgery and satisfactory cosmetic and functional results. CONCLUSION: The modified rhomboid flap is a simple and reliable technique for all defects of the medial canthal area.

Hide-and-seek: Neurotropes Plattenepithelkarzinom der periorbitalen Region - eine Fallserie und Übersichtsarbeit aktueller Literatur.

Das Plattenepithelkarzinom ist nach dem Basalzellkarzinom das zweithäufigste Malignom der Haut und wird vorwiegend an sonnenexponierten Stellen wie der Gesichtshaut diagnostiziert. Diese meist lokal destruktiv wachsende Malignität kann durchaus auch invasives Wachstumsverhalten, wie perineurale Ausbreitungsmechanismen, aufweisen. Das Plattenepithelkarzinom der periorbitalen Region ist in bis zu 14 % der Fälle mit perineuraler Invasion assoziiert. Vor allem in diesem Bereich birgt die anatomische Nähe zu den Hirnnerven das Risiko einer Progression Richtung zentrales Nervensystem, was mit einer schlechteren Prognose assoziiert ist. Der klinisch unauffällige Charakter dieser Entität resultiert oft in einer Verzögerung der definitiven Diagnosestellung, wodurch die vollständige Resektion und anschließende Rekonstruktion erschwert werden. Eine aufmerksame klinische Evaluierung kann bereits vor Erlangen histologischer Befunde Hinweise für ein perineurales Wachstum liefern. Neben fünf herausfordernden Fällen analysiert diese Arbeit Risikofaktoren, klinische als auch histologische Merkmale und Behandlungsoptionen des periorbitalen Plattenepithelkarzinoms mit perineuraler Invasion.

Hide-and-seek: Neurotropic squamous cell carcinoma of the periorbital region - a series of five cases and review of the literature.

Squamous cell carcinoma is the second most common malignancy of the skin after basal cell carcinoma and mainly found in sun-exposed areas such as the face. This mostly locally destructive malignancy may show invasive growth and insidious mechanisms of dissemination such as perineural invasion. Periorbital squamous cell carcinoma is associated with perineural invasion in up to 14 % of cases. Specifically in this region, the proximity to cranial nerves and therefore the associated risk of progression to the central nervous system are associated with poor prognosis. The clinically concealed character of this entity often leads to a delay in diagnosis and consequently makes complete resection and reconstruction demanding. Careful clinical evaluation often hints at perineural invasion before obtaining histology. Aside from presenting five challenging cases, this work analyzes risk factors, clinical as well as histological features, and treatment options for periorbital squamous cell carcinoma with perineural invasion.

Functional Shoulder Outcome and Quality of Life Following Modified Muscle-Sparing Pectoralis Major Flap Surgery.

BACKGROUND: The pedicled pectoralis major muscle flap (PMMF) is a well established flap for fistula prophylaxis after salvage laryngectomy. To reduce donor site morbidity, we established a modified muscle-sparing harvesting technique. We herein investigate postoperative shoulder function and health-related quality of life (HRQOL). METHODS: A chart review of patients receiving the modified muscle-sparing pectoralis major muscle flap between 2013-2020 was performed. Nineteen patients (male = 18, female = 1) were potentially eligible and six male patients were ultimately enrolled. Postoperative shoulder function was assessed on both sides (flap side versus non-flap side) using the Constant Murley Score and the Bak criteria. Health-related quality of life was assessed with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire in cancer patients (EORTC QLQ-C30) and head and neck cancer patients (EORTC H&N35). RESULTS: No Constant Murley Score subscale was statistically significant (p ≥ 0.180). Bak criteria was overall rated "Good". Solely upper extremity adduction force was significantly altered on the flap side (p = 0.039). Median EORTC QLQ-C30 score was 82.2 (IQR 11.1) on the functional scale and 10.3 (IQR 2.6) on the symptomatic scale. Median quality of life score was 75.0 (IQR 33.3) and median EORTC QLQ-H&N35 was 20.6 (IQR 9.8). CONCLUSIONS: Postoperative shoulder function after modified muscle-sparing pectoralis major muscle flap surgery is comparable to function of the healthy side with a significant deficiency in adduction force not compromising daily life in this small study cohort.

Simple, but effective: Nasal splinting for airway securement in free flap reconstruction following orbital exenteration.

Orbital exenteration is a disfiguring procedure that often results in free tissue transfer for reconstructive purposes. The reconstructive focus is the obliteration of dead space while sparing the nasal airway, particularly if the medial orbital wall was resected. Prolapse of transferred tissue into the nasal airway may cause breathing difficulties drastically compromising quality of life. The objective of this study was to demonstrate the effectiveness and feasibility of temporary nasal septum splints as mechanical support for transferred tissue, to prevent airway obstruction. This novel application technique was employed in three patients between 2017 and 2018. No flap loss or sino-orbital fistulas were observed. On postoperative MRI and endoscopy, a patent nasal airway was observed at all times. Temporary nasal splinting in combination with free tissue transfer proved to be a simple, but effective reconstructive option for securing the nasal airway following orbital exenteration with resection of the medial orbital wall.

Oxidant therapy improves adipogenic differentiation of adipose-derived stem cells in human wound healing.

BACKGROUND: Adipose-derived stem cells (ASC) and adipocytes are involved in numerous physiological and pathophysiological conditions, which have been extensively described in subcutaneous and visceral fat depots over the past two decades. However, much less is known about ASC and adipocytes outside classical fat tissue depots and their necessity in tissue remodeling after injury. Therefore, we investigated the etiology of adipocytes in human granulation tissue and define their possible role wound healing. METHODS: Identification of human wound tissue adipocytes was determined by immunohistochemical staining of granulation tissue sections from patients undergoing surgical debridement. Stromal cell fractions from granulation tissue and subcutaneous fat tissue were generated by collagenase type II-based protocols. Pro- and anti-inflammatory wound bed conditions were mimicked by THP1- and CD14+ monocyte-derived macrophage models in vitro. Effects of macrophage secretome on ASC differentiation and metabolism were determined by immunoblotting, flow cytometry, and microscopy assessing early and late adipocyte differentiation states. Functional rescuing experiments were conducted by lentiviral transduction of wildtype PPARG, IL1RA, and N-chlorotaurine (NCT) treatment. RESULTS: Single and clustered adipocyte populations were detected in 11 out of 13 granulation tissue specimens and single-cell suspensions from granulation tissue showed adipogenic differentiation potential. Pro-inflammatory signaling by IFNG/LPS-stimulated macrophages (M (IFNG/LPS)) inhibited the maturation of lipid droplets in differentiated ASC. In contrast, anti-inflammatory IL4/IL13-activated macrophages (M (IL4/IL13)) revealed minor effects on adipocyte development. The M (IFNG/LPS)-induced phenotype was associated with a switch from endogenous fatty acid synthesis to glycolysis-dominated cell metabolism and increased pro-inflammatory cytokine production. Impaired adipogenesis was associated with increased, but seemingly non-functional, CEBPB levels, which failed to induce downstream PPARG and CEBPA. Neither transgenic PPARG overexpression, nor inhibition of IL1B was sufficient to rescue the anti-adipogenic effects induced by IFNG/LPS-activated macrophages. Instead, macrophage co-treatment during stimulation with NCT, a mild oxidant produced by activated granulocytes present in human wounds in vivo, significantly attenuated the anti-adipogenic effects. CONCLUSIONS: In conclusion, the appearance of adipocytes in wound tissue indicates a prevailing anti-inflammatory environment that could be promoted by NCT treatment and may be associated with improved healing outcomes.

[Deep sternal wound infection after sternotomy - Report of the consensus workshop of the German-Speaking Society for Microsurgery of Peripheral Nerves and Vessels (DAM)]. / Der tiefe sternale Wundinfekt nach Sternotomie.

Deep sternal wound infection (TSWI) is a potentially life-threatening complication that may occur after median sternotomy, contributing to prolonged hospital stay and increased health care costs. Bacterial infection is often characterized by biofilm formation on implant material and/or dead bone. Diagnosis is made upon clinical signs and symptoms of local and systemic infection. Early multidisciplinary decision making is needed for optimal patient care. Repeated surgical wound debridements accompanied by wound conditioning are performed until clean circumstances are achieved. Thereafter, wound closure and defect reconstruction are obtained using a variety of pedicled and microvascular flaps.