Leptin promotes adipocytes survival in non-vascularized fat grafting via perfusion increase.

BACKGROUND: Though autologous fat transplantation is regularly and successfully performed in plastic surgery, little is known about the factors that contribute to the rise of preadipocytes and how the viability of adipocytes is regulated. As sufficient blood supply is a key parameter for the transplant's survival, we opted to analyse the development of preadipocytes within the fat transplant via stimulation of tissue perfusion with the angiogenesis enhancing hormone leptin. METHODS: In a murine (C57BL/6N) model inguinal fat was autologously transplanted into a dorsal skinfold chamber. In the intervention group the fat transplant was treated with local administration of leptin (3 µg/ml) at days 3, 7 and 10 after transplantation. Saline solution was administered respectively in the control group. On the postoperative days 3, 7, 10, and 15 intra vital microscopy was done to assess the functional vessel density, vessel diameter, adipocyte survival and preadipocyte development. The study was completed by histological tissue analysis on days 15 after transplantation. RESULTS: Leptin administration leads to an increase of angiogenesis, which starts from day 7 after implantation and elevates perfusion as well as functional vessel density FVD at days 10 and 15 after transplantation. Perfusion develops first from the border zones of the transplant. Histological evaluation showed that the percentage of perilipin positive adipocytes increased markedly in the study group of mice. Moreover, fat transplants of mice of the leptin group disclosed significantly higher Pref-1 positive cells than fat transplants of the control group. The findings reported in this study indicate that the leptin can enhance the survival and the quality of grafted fat tissue, which may be due to induction of angiogenesis. CONCLUSION: Leptin administration to fat transplants induced an increase in angiogenesis in the transplanted tissue and may play a role in reducing the resorption rate of lipoaspirates.

Effects of Extracorporeal Shock Waves on Microcirculation and Angiogenesis in the in vivo Wound Model of the Diver Box.

INTRODUCTION: Extracorporeal shock waves (ESWs) have been shown to have a positive effect on skin wound healing; however, little is known on the regeneration of the microcirculation and angiogenesis as well as the different application modes. METHODS: A total of 40 BALB/c mice were provided with dorsal skin fold chambers and were divided into 3 therapy groups (n = 30) and one control group (n = 10). The 3 therapy groups were treated with shock waves at different pulse rates (500-1,000 pulses/min) and application frequencies (day 0 and day 6 or day 0 only). Photographic documentation and intravital microscopy were carried out on day 1, 2, 4, and 6 after wounding. RESULTS: Using the newly developed Diver Box, shock waves could be applied in vivo without mechanical tissue damage. Shock wave therapy to skin wounds demonstrated to induce faster wound closure rates in the beginning than controls in groups with higher pulse rates and frequencies of the shock waves. Furthermore, the regeneration of microcirculation and perfusion in the healing skin was significantly improved after the application of, in particular, higher pulse rates as given by increased numbers of perfused capillaries and functional vessel density. The study of inflammation showed, especially in high-pulse ESW groups, higher leukocyte counts, and rolling leukocytes over time until day 6 as a response to the induction of inflammatory reaction after ESW application. Angiogenesis showed a marked increase in positive areas as given by sprouts, coils, and recruitments in all ESW groups, especially between days 4 and 6. CONCLUSION: The major findings of this trial demonstrate that ESW therapy to skin wounds is effective and safe. This is demonstrated by the initially faster wound closure rate, but later the same wound closure rate in the treatment groups than in controls. Furthermore, during the regeneration of microcirculation and perfusion in the healing skin, a significant improvement was observed after the application of, in particular, higher ESW pulse rates, suggesting an ESW-related increase in nutrient and oxygen supply in the wound tissue.

Hyperspectral Imaging (HSI) as a new diagnostic tool in free flap monitoring for soft tissue reconstruction: a proof of concept study.

OBJECTIVES: Free flap surgery is an essential procedure in soft tissue reconstruction. Complications due to vascular compromise often require revision surgery or flap removal. We present hyperspectral imaging (HSI) as a new tool in flap monitoring to improve sensitivity compared to established monitoring tools. METHODS: We performed a prospective observational cohort study including 22 patients. Flap perfusion was assessed by standard clinical parameters, Doppler ultrasound, and HSI on t0 (0 h), t1 (16-28 h postoperatively), and t2 (39-77 h postoperatively). HSI records light spectra from 500 to 1000 nm and provides information on tissue morphology, composition, and physiology. These parameters contain tissue oxygenation (StO2), near-infrared perfusion- (NIR PI), tissue hemoglobin- (THI), and tissue water index (TWI). RESULTS: Total flap loss was seen in n = 4 and partial loss in n = 2 cases. Every patient with StO2 or NIR PI below 40 at t1 had to be revised. No single patient with StO2 or NIR PI above 40 at t1 had to be revised. Significant differences between feasable (StO2 = 49; NIR PI = 45; THI = 16; TWI = 56) and flaps with revision surgery [StO2 = 28 (p < 0.001); NIR PI = 26 (p = 0.002); THI = 56 (p = 0.002); TWI = 47 (p = 0.045)] were present in all HSI parameters at t1 and even more significant at t2 (p < 0.0001). CONCLUSION: HSI provides valuable data in free flap monitoring. The technique seems to be superior to the gold standard of flap monitoring. StO2 and NIR PI deliver the most valuable data and 40 could be used as a future threshold in surgical decision making. Clinical Trial Register This study is registered at the German Clinical Trials Register (DRKS) under the registration number DRKS00020926.

[Implementation of the wide awake local anesthesia no tourniquet (WALANT) type of anesthesia in hand surgery]. / Einsatz der WALANT("wide awake local anesthesia no tourniquet")-Narkoseart in der Handchirurgie.

Wide awake local anesthesia no tourniquet (WALANT) refers to an anesthesia technique with low bleeding and complication rates, which enables interventions on the hand in an awake patient without the use of a tourniquet. Bleeding control is achieved through addition of vasoconstrictors to the infiltration solution. Since the motor function of the extremity is not affected, it offers the additional possibility of intraoperative active function testing. The WALANT procedure constitutes an established, effective, easily learnt and resource-sparing technique. The spectrum of surgical possibilities with WALANT is wide and covers nearly all elective and many emergency procedures. Due to multiple advantages in contrast to other regional and general anesthesia procedures, WALANT features an increasing spectrum of surgical applications and practitioners. It is therefore of interest for hand surgeons working both in hospitals and private practices.

Outcomes of tissue reconstruction in distal lower leg fractures: a retrospective cohort study.

BACKGROUND: Open and closed fractures can be associated with posttraumatic or postoperative soft tissue defects caused by initial trauma, operative procedures, or infections. This study evaluated the postoperative outcomes in patients with open or closed lower leg fractures, related soft tissue defects, and subsequent flap coverage. METHODS: We performed a retrospective single-center cohort study in a level 1 trauma center. We analyzed the patients treated from January 2012 through December 2017 and recorded demographics, treatment, and outcome data. The outcome data were measured via patient-reported Foot and Ankle Outcomes Scores (FAOS) and EQ-5D-5L scores. RESULTS: We included 22 patients with complicated fractures (11 open and 11 closed) and subsequent soft tissue defects and flap coverages. The mean follow-up time was 41.2 months. Twenty-one patients developed infections, and necrosis at the site of surgery manifested in all closed fractures. Therefore, all patients needed soft tissue reconstructions. Preoperatively, 16 patients underwent arterial examinations via angiography and six underwent ultrasound examinations of the venous system. Ten patients had complications involving the flaps due to ischemia and consequent necrosis. The mean EQ-5D index was 0.62 ± 0.27, and EQ-5D VAS score was 57.7 ± 20.2. The mean FAOS was 60.7 ± 22.2; in particular, quality of life was 32.3 ± 28.8. The rate of returning to work in our patient group was 37.5% after 1 year. CONCLUSIONS: Distal tibial fractures often require revisions and soft tissue reconstruction. The evaluated patient population had poor outcomes in terms of function, quality of life, and return to work. Furthermore, patients suffering from flap ischemia have worse outcomes than those without flap ischemia.

Scar quality examination comparing titanium-coated suture material and non-coated suture material on flap donor sites in reconstructive surgery.

BACKGROUND: Wound healing and scar quality after trauma are subject to impairment through excessive wound healing, chronic wound or even surgical site infections. Optimizing the process of scar formation and skin healing is crucial in virtually all fields of medicine. In this regard, we tested the possible usage and advantages of titanium coated suture material. METHODS: We performed a prospective observational cohort study including 30 patients who underwent soft tissue reconstruction. One half of the donor flap site was sutured with titanium coated suture material, while the other half was closed with non-coated sutures. Scar quality of the donor flap site was assessed by photographs and POSAS scores on days 2-5, 14, 42, 72 and 180 postoperatively. RESULTS: No difference between the titanium coated sutures and non-coated sutures was seen in the POSAS assessment, neither for the patient scale at 14, 42, 72 and 180 days, nor for the observer scale on the same dates. Comorbidities like diabetes, chronic renal failure and smoking as well as the BMI of each patient affected the wound healing process to an equal degree on both sides of the suture. CONCLUSIONS: No difference between the titanium coated and non-titanium-coated suture material was seen in the POSAS assessment in regard to scar quality and wound healing. The titanium-coated suture material can be considered to be equally as effective and safe in all qualities as the non-titanium-coated suture material, even in patients with comorbidities. Clinical trial register This study is registered at the German Clinical Trials Register (DRKS) under the registration number DRKS00021767. ( https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00021767 ).

Deep sternal wound infection - latissimus dorsi flap is a reliable option for reconstruction of the thoracic wall.

BACKGROUND: At present, data describing patients' long-term outcomes, quality of life, and survival after deep sternal wound infection are rarely available. The purpose of our study was to evaluate functional outcome and patient well-being after debridement and reconstruction of the sternal defect using a pedicled latissimus dorsi flap following deep sternal wound infection (DSWI). METHODS: This retrospective analysis reviewed 106 cases of DSWI after open-heart surgery treated between May 1, 2012, and May 31, 2015. The parameters of interest were demographic and medical data, including comorbidity and mortality. Follow-up consisted of physical examination of the patients using a specific shoulder assessment, including strength tests and measurements of pulmonary function. RESULTS: The population consisted of 69 (65%) male and 37 (35%) female patients. Their average age at the time of plastic surgery was 69 years (range: 35-85). The 30-day mortality was 20% (n = 21); after one-year, mortality was 47% (n = 50), and at follow-up, it was 54% (n = 58). Heart surgery was elective in 45 cases (42%), urgent in 31 cases (29%) and for emergency reasons in 30 cases (28%). The preoperative European System for Cardiac Operative Risk Evaluation (EuroSCORE) averaged 16.3 (range: 0.88-76.76). On the dynamometer assessment, a value of 181 Newton (N) (±97) could be achieved on the donor side, in contrast to 205 N (±91) on the contralateral side. The inspiratory vital capacity of the lung was reduced to an average of 70.58% (range: 26-118), and the forced expiratory volume in 1 s was decreased to an average of 69.85% (range: 38.2-118). CONCLUSIONS: Given that only small adverse effects in shoulder function, strength, and pulmonary function were observed, the latissimus dorsi flap appears to be a safe and reliable option for the reconstruction of the sternal region after DSWI.

[Pedicled Omentum Flaps in the Management of Deep Sternal Wound Infections]. / Der gefäßgestielte Omentumlappen zur Behandlung tiefer sternaler Wundinfekte.

AIM: Coverage of a deep sternal wound infection with a greater omentum flap. Due to a persistent infection caused by an infected aortic prosthesis, the primarily performed reconstruction with a latissimus dorsi flap had to be revised, and an alternative solution had to be found. INDICATION: A deep sternal wound infection is a rare but devastating complication following median sternotomy. If the commonly used muscle flap is not sufficient and artificial material is still present in the wound, for instant drivelines or a vascular prosthesis, the greater omentum flap is a useful option due to its immunologic capacity. METHOD: After an exploration of the persisting infected deep sternal wound, a radical debridement is performed followed by a jet lavage. The soft tissue from the greater omentum is prepared via median laparotomy and transferred through a tunnel created in the diaphragm. Then it is pulled into the wound cavity and can be used for tension-free sheathing of the aortic prosthesis. The previously used muscle flap can additionally be used for superficial soft tissue coverage. CONCLUSION: Due to its immunologic competence, the greater omentum flap is a good treatment alternative to the commonly used muscle flaps in defects with infected artificial material.

An Asian Perspective on Povidone Iodine in Wound Healing.

Antiseptics, with a broader spectrum of antimicrobial efficacy, lower risk of antibiotic resistance development, and minimal collateral damage to host tissues, are important alternatives to control the bioburden in wounds. Povidone iodine (PVP-I), in use for several decades, has the broadest spectrum of activity, a persistent antimicrobial effect, an ability to penetrate biofilms, and a lack of acquired or cross-resistance. It demonstrates good skin tolerance and low cytotoxicity. However, some reports on PVP-I have raised concerns over allergy, ineffective penetration, and toxic effects on host cells. The majority of these concerns are based on in vitro or rodent wound studies with diverse study designs and outcomes; these results may not be directly applicable in the clinical reality in humans. In this paper, we discuss the efficacy and safety of PVP-I and outline its place in wound healing in Asia, based on an appraisal of recent literature and clinical practice across the region.

A double-barrelled fibula graft restoring pelvic stability after late posterior ring instability related to a surgical treated osteitis pubis: a case report.

BACKGROUND: Osteitis pubis or symphysitis pubis is a rare occurring non-infectious inflammation of the symphysis, the adjacent pubic bones and surrounding tissue. The therapy might be conservative or surgical by a resection of the symphysis and involved parts of the pubic bone. Nevertheless, this resection might lead to an anterior instability impairing the posterior arch and the sacroiliac joints in the aftermath. CASE PRESENTATION: Here, we report about a 50-year-old women suffering from osteitis pubis treated by wedge resection of the symphysis and parts of the pubic bone. To maintain stability and for local antibiotic treatment a cement spacer was implemented. By clinical inconspicuous findings and the patient's desire, no further surgery was performed. However, 2 years after surgery the spacer dislocated and the patient complained about pain in the posterior arch due to an impaired mobility. Reconstruction surgery was planned including the bridging of the accrued space with a vascularized double-barrelled fibula graft, plate osteosynthesis and rectus abdominis flap coverage. The performed surgery led to pain relief and increased mobility. CONCLUSION: The present case highlights the possible complication of surgical treated osteitis pubis leading to anterior arch instability affecting the posterior arch and thus impairing pelvic ring stability and patient mobility. Furthermore, we describe an opportunity to treat this complication or other etiologies contributing to anterior pelvic ring stability with large bone defects using a vascularized double-barrelled fibula graft to restore pelvic stability.

Telomere length differences between subcutaneous and visceral adipose tissue in humans.

Adipocyte hypertrophy and hyperplasia have been shown to be associated with shorter telomere length, which may reflect aging, altered cell proliferation and adipose tissue (AT) dysfunction. In individuals with obesity, differences in fat distribution and AT cellular composition may contribute to obesity related metabolic diseases. Here, we tested the hypotheses that telomere lengths (TL) are different between: (1) abdominal subcutaneous and omental fat depots, (2) superficial and deep abdominal subcutaneous AT (SAT), and (3) adipocytes and cells of the stromal vascular fraction (SVF). We further asked whether AT TL is related to age, anthropometric and metabolic traits. TL was analyzed by quantitative PCR in total human genomic DNA isolated from paired subcutaneous and visceral AT of 47 lean and 50 obese individuals. In subgroups, we analyzed TL in isolated small and large adipocytes and SVF cells. We find significantly shorter TL in subcutaneous compared to visceral AT (P < 0.001) which is consistent in men and subgroups of lean and obese, and individuals with or without type 2 diabetes (T2D). Shorter TL in SAT is entirely due to shorter TL in the SVF compared to visceral AT (P < 0.01). SAT TL is most strongly correlated with age (r = -0.205, P < 0.05) and independently of age with HbA1c (r = -0.5, P < 0.05). We found significant TL differences between superficial SAT of lean and obese as well as between individuals with our without T2D, but not between the two layers of SAT. Our data indicate that fat depot differences in TL mainly reflect shorter TL of SVF cells. In addition, we found an age and BMI-independent relationship between shorter TL and HbA1c suggesting that chronic hyperglycemia may impair the regenerative capacity of AT more strongly than obesity alone.

Proposal of Vibrionimonas magnilacihabitans gen. nov., sp. nov., a curved Gram-stain-negative bacterium isolated from lake water.

A mesophilic bacterium appearing as curved rod-shaped cells was isolated from Lake Michigan water. It exhibited highest similarities with Sediminibacterium ginsengisoli DCY13(T) (94.4%); Sediminibacterium salmoneum NJ-44(T) (93.6%) and Hydrotalea flava CCUG 51397 (T) (93.1%) while similarities with other recognized species were <92.0%. The primary polar lipid was phosphatidylethanolamine, with moderate amounts of two unidentified glycolipids, three unknown polar lipids, one unknown aminophospholipid and one aminolipid. The primary respiratory quinone was MK-7 and sym-homospermidine was the primary polyamine. The major cellular fatty acids were iso-C(15 : 1)G, iso-C(15 : 0), iso-C(16 : 0) 3-OH and iso-C(17 : 0) 3-OH, with moderate amounts of iso-C(16 : 0). The presence of glycolipids differentiated the novel strains from related genera. The DNA mol% G+C content of the type strain MU-2(T) was 45.2. Results for other phenotypic and molecular analyses indicated that strain MU-2(T) is a representative of a novel genus and species for which the name Vibrionimonas magnilacihabitans is proposed. The type strain is MU-2(T) ( = NRRL B-59231 = DSM 22423).

[Cost comparison of conservative vs. surgical treatment of chronic lymphedema]. / Kostenvergleich der konservativen vs. operativen Therapie des chronischen Lymphödems.

BACKGROUND: Lymphedema is primarily treated conservatively using complex physical decongestion treatment (CDT). Lymphovenous anastomosis (LVA), vascularized lymph node transplantation (VLNT) and liposuction are available as surgical treatment methods; however, reimbursement in the diagnosis-related groups (DRG) system is sometimes inadequate or only possible following an individual application. The costs of these relatively new surgical procedures have not yet been set in relation to those of CDT. METHOD: The costs of conservative treatment were determined in accordance with the guidelines. The costs for LVA, VLNT and liposuction of the upper and lower extremities were estimated on the basis of the DRG reimbursement per case and the expected reduction in conservative measures according to current knowledge. The annual treatment costs were then compared. RESULTS: The annual treatment costs of LVA and VLNT are already lower than conservative treatment alone in the second postoperative year. Liposuction reaches this point in the 6th (upper extremity) or 47th postoperative year (lower extremity). CONCLUSION: The evidence for the positive effects of lymphatic surgery is still limited; however, it is recognizable that the curative surgical approach can significantly reduce the treatment costs and improve the quality of life of lymphedema patients; however, there is a lack of adequate reflection of the surgical effort in the reimbursement.

Translation, Cross-Cultural Adaptation and Validation of the Lymphedema Quality of Life Questionnaire (LYMQOL) in German-Speaking Patients with Lymphedema of the Lower Limbs.

The LYMQOL Leg questionnaire is the most widely used, evidence-based tool for the assessment of health-related quality of life (HRQoL) in patients with lower limb lymphedema (LLL). It has been translated into several languages, but a German version is currently lacking. The aim of our study was to validate a German translation of LYMQOL Leg. Translation and cross-cultural adaptation were performed in accordance with ISPOR principles. A total of 103 patients with LLL from Germany, Austria, and Switzerland were interviewed twice. The content and face validity assessments indicated that the German LYMQOL Leg questionnaire was acceptable for interviewing patients with lymphedema. Comparing the LYMQOL Leg with the SF-36 demonstrated good construct validity. Reliability determined by the test-retest procedure was good (intra-class-correlation coefficients 0.68-0.92). Cronbach's alpha values ranged from 0.76 to 0.90 in both interviews, showing an acceptable internal consistency. The four domains of the questionnaire reached a cumulative variance of 52.7% in the factor analysis. The association between the lymphedema stages and the LYMQOL Leg domain scores was not significant. In conclusion, the validity of the German version of LYMQOL Leg, called LYMQOL Bein, was confirmed and thus represents a suitable tool for measuring HRQoL in German-speaking patients with LLL.

Hyperspectral Imaging Detects Clitoral Vascular Issues in Gender-Affirming Surgery.

The aim of this study was to assess the efficacy of hyperspectral imaging (HSI) as an intraoperative perfusion imaging modality during gender affirmation surgery (GAS). The hypothesis posited that HSI could quantify perfusion to the clitoral complex, thereby enabling the prediction of either uneventful wound healing or the occurrence of necrosis. In this non-randomised prospective clinical study, we enrolled 30 patients who underwent GAS in the form of vaginoplasty with the preparation of a clitoral complex from 2020 to 2024 and compared patients' characteristics as well as HSI data regarding clitoris necrosis. Individuals demonstrating uneventful wound healing pertaining to the clitoral complex were designated as Group A. Patients with complete necrosis of the neo-clitoris were assigned to Group B. Patient characteristics were collected and subsequently a comparative analysis carried out. No significant difference in patient characteristics was observed between the two groups. Necrosis occurred when both StO2 and NIR PI parameters fell below 40%. For the simultaneous occurrence of StO2 and NIR PI of 40% or less, a sensitivity of 92% and specificity of 72% was calculated. Intraoperatively, the onset of necrosis in the clitoral complex can be reliably predicted with the assistance of HSI.

A Platform for Testing the Biocompatibility of Implants: Silicone Induces a Proinflammatory Response in a 3D Skin Equivalent.

Biocompatibility testing of materials is carried out in 2D cell cultures or animal models despite serious limitations. 3D skin equivalents are advanced in vitro models for human skin. Silicone has been shown to be noncytotoxic but capable of eliciting an immune response. Our aim was to (1) establish a 3D skin equivalent to (2) assess the proinflammatory properties of silicone. We developed a coculture of keratinocytes and fibroblasts resulting in a 3D skin equivalent with an implant using samples from a breast implant. Samples with and without the silicone implant were studied histologically and immunohistochemically in comparison to native human skin samples. Cytotoxicity was assessed via LDH-assay, and cytokine response was assessed via ELISA. Histologically, our 3D skin equivalents had a four-layered epidermal and a dermal component. The presence of tight junctions was demonstrated in immunofluorescence. The only difference in 3D skin equivalents with implants was an epidermal thinning. Implanting the silicone samples did not cause more cell death, however, an inflammatory cytokine response was triggered. We were able to establish an organotypical 3D skin equivalent with an implant, which can be utilised for studies on biocompatibility of materials. This first integration of silicone into a 3D skin equivalent confirmed previous findings on silicone being non-cell-toxic but capable of exerting a proinflammatory effect.

A single center prospective study of bilateral breast reconstruction with free abdominal flaps: a critical analyses of 144 patients.

BACKGROUND: Bilateral breast reconstruction utilising autologous free tissue transfer is a complex procedure with multiple options for donor tissue available. Autogenous breast reconstruction techniques have evolved over the last three decades to meet this goal. The aim of this study was to determine the outcomes of patients undergoing bilateral breast reconstruction with DIEAP, TRAM or SIEA flaps. MATERIAL AND METHODS: A prospective study was performed in our Interdisciplinary Breast Centre from July 2004 until December 2011 in 144 patients. Demographic information, diabetes mellitus type I status, tobacco use, tumor stage, primary/secondary reconstruction, operative technique, adjuvant therapy received, length of follow-up, and complications were evaluated. Complications were divided into donor site and recipient site. To investigate which risk factors were independently related to flap loss (complete or partial), multiple linear regression analysis was performed. RESULTS: The study identified 144 patients who had bilateral breast reconstruction with DIEAP, TRAM or SIEA flaps. For all flaps (n=248), outcome included 98.4% survival and 0.7% vein microanastomosis revision. Recipient site complications included 1.6% complete flap loss, 0.8% fat necrosis, 2.9% partial skin loss/dehiscence flap necrosis and 2.0% haematoma rate. Donor site complications included 3.7% partial skin loss/dehiscence. There was evidence of abdominal bulges in TRAM patients (1.1%) but no hernias in any patients. BMI is a major determinant of flap loss (complete or partial) in these patients. CONCLUSIONS: The primary goal of bilateral breast reconstruction is to provide a treatment option that can create a natural, symmetric breast mounds with minimal donor-site morbidity following bilateral mastectomies. These results support weight loss therapy prior to bilateral breast reconstruction.

C-type natriuretic peptide slows down wound healing but promotes angiogenesis in SKH1-hr hairless mice.

C-type natriuretic peptide (CNP) is known to increase growth rate of endothelial cells in vitro. In addition, gene transfer of CNP into ischaemic muscle was shown to induce angiogenesis. So far, no study has addressed the effect of CNP on dermal wound healing. The ear wound model in mice was used in this study. The first group was treated with dsRed-CNP plasmid, whereas the second group was transfected with the empty dsRed-sine plasmid, lacking sequence coding for CNP. The third group was sham operated and treated with saline to serve as second control. Wound size was measured on days 0, 1, 3, 5, 7, 9, 11 and 14. On days 7 and 14 capillary density was analysed. Wound closure rate was significantly reduced in mice treated with CNP [dsRed-CNP 73·3 ± 3·2% versus dsRed-sine 94·5 ± 2·4% versus saline 92·1 ± 2·4%, n = 8 per group, analysis of variance (ANOVA) P < 0·001] at day 7 postop. Capillary density was found to be significantly higher in CNP-treated mice (dsRed-CNP 18·7 ± 3·9 versus dsRed-sine 12·3 ± 2·7 versus control 10·1 ± 4·7, CD31(+) capillaries per microscope field, ANOVA P = 0·018) at day 14 postoperative. CNP significantly reduces wound closure rate in hairless mice but promotes the development of new blood vessels. A possible explanation is the dual effect of CNP, inhibiting growth of fibromyoblasts but stimulating growth of endothelial cells. Thus, CNP may serve as a therapeutic approach to diseases caused by hyperfibrosis.

Diagnostical accuracy of hyperspectral imaging after free flap surgery.

Microsurgical free-tissue transfer has been a safe option for tissue reconstruction. This study aimed to analyze the diagnostic accuracy of hyperspectral imaging (HSI) after free-tissue transfer surgery. From January 2017 to October 2019, 42 consecutive free-flap surgeries were performed, and their outcomes were analyzed via HSI. Clinical examination of free-flap perfusion was initially performed. Clinical examination findings were subsequently compared with those of HSI. Potential venous congestion with subsequent necrosis was defined as a tissue hemoglobin index of ≥53%. Student's t-test was used to compare the results of the analysis. The evaluation of sensitivity and specificity for flap failure detection was time dependent using the Fisher's exact test. A p-value of ≤0.05 was considered statistically significant. Microsurgical tissue transfer success rate was 84%. Seven patients presented with venous congestion that caused total flap necrosis. Overall, 124 assessments were made. HSI accurately identified 12 out of 19 pathological images: four as false positive and seven as false negative. The sensitivity and specificity of HSI were 57 and 94%, respectively, compared to those of clinical examination that were 28 and 100%, respectively, within 24 h following tissue transfer. The sensitivity and specificity of HSI were 63 and 96%, respectively, compared to those of clinical examination that were 63 and 100%, respectively, within the first 72 h. A tissue hemoglobin index of ≥53% could predict venous congestion after free-flap surgery. HSI demonstrated higher sensitivity than clinical examination within the first 24 h; however, it was not superior compared to clinical findings within 72 h.

Organotypic 3D Co-Culture of Human Pleura as a Novel In Vitro Model of Staphylococcus aureus Infection and Biofilm Development.

Bacterial pleural infections are associated with high mortality. Treatment is complicated due to biofilm formation. A common causative pathogen is Staphylococcus aureus (S. aureus). Since it is distinctly human-specific, rodent models do not provide adequate conditions for research. The purpose of this study was to examine the effects of S. aureus infection on human pleural mesothelial cells using a recently established 3D organotypic co-culture model of pleura derived from human specimens. After infection of our model with S. aureus, samples were harvested at defined time points. Histological analysis and immunostaining for tight junction proteins (c-Jun, VE-cadherin, and ZO-1) were performed, demonstrating changes comparable to in vivo empyema. The measurement of secreted cytokine levels (TNF-α, MCP-1, and IL-1ß) proved host-pathogen interactions in our model. Similarly, mesothelial cells produced VEGF on in vivo levels. These findings were contrasted by vital, unimpaired cells in a sterile control model. We were able to establish a 3D organotypic in vitro co-culture model of human pleura infected with S. aureus resulting in the formation of biofilm, including host-pathogen interactions. This novel model could be a useful microenvironment tool for in vitro studies on biofilm in pleural empyema.