Free Flaps for Skin and Soft Tissue Reconstruction in the Elderly Patient: Indication or Contraindication

BACKGROUND

Increased lifespan and the improvement of medical treatment have given rise to research in reconstructive procedures in elderly patients. Higher postoperative complication rates, longer rehabilitation, and surgical difficulties remain a problem in the elderly. We asked whether a free flap in elderly patients is an indication or a contraindication and performed a retrospective, monocentric study.

METHODS

Patients were divided into two groups (YOUNG 0-59 years; OLD > 60 years). The endpoint was the survival of flaps and their dependence on patient- and surgery-specific parameters using multivariate analysis.

RESULTS

A total of 110 patients (OLD n = 59) underwent 129 flaps. The chance of flap loss increased as soon as two flaps were performed in one surgery. Anterior lateral thigh flaps had the highest chance for flap survival. Compared with the lower extremity, the head/neck/trunk group had a significantly increased chance of flap loss. There was a significant increase in the odds of flap loss in linear relation to the administration of erythrocyte concentrates.

CONCLUSION

The results confirm that free flap surgery can be indicated as a safe method for the elderly. Perioperative parameters such as two flaps in one surgery and transfusion regimens must be considered as risk factors for flap loss.

Improving Vascularization of Biomaterials for Skin and Bone Regeneration by Surface Modification: A Narrative Review on Experimental Research

Artificial tissue substitutes are of great interest for the reconstruction of destroyed and non-functional skin or bone tissue due to its scarcity. Biomaterials used as scaffolds for tissue regeneration are non-vascularized synthetic tissues and often based on polymers, which need ingrowth of new blood vessels to ensure nutrition and metabolism. This review summarizes previous approaches and highlights advances in vascularization strategies after implantation of surface-modified biomaterials for skin and bone tissue regeneration. The efficient integration of biomaterial, bioactive coating with endogenous degradable matrix proteins, physiochemical modifications, or surface geometry changes represents promising approaches. The results show that the induction of angiogenesis in the implant site as well as the vascularization of biomaterials can be influenced by specific surface modifications. The neovascularization of a biomaterial can be supported by the application of pro-angiogenic substances as well as by biomimetic surface coatings and physical or chemical surface activations. Furthermore, it was confirmed that the geometric properties of the three-dimensional biomaterial matrix play a central role, as they guide or even enable the ingrowth of blood vessels into a biomaterial.

Facilitation of adhesion and spreading of endothelial cells on silicone oxide-coated dacron material by microwave-excited low-pressure plasma

Objectives

Autologous transplants are still the means of choice for bypass surgery. In addition to good tolerability, there is a reduced thrombogenicity and fewer neointima hyperplasia compared to artificial materials. However, since viable transplants are limited, attempts are being made to improve existing artificial vascular prosthesis material. Next to the reduction of thrombogenicity, a rapid endothelialization of the vascular graft should reduce intimal hyperplasia and thus prevent stenoses. The effect of newly developed silicon oxide coatings on the growth of endothelial cells was therefore the goal of this work in a cell culture study.

Methods

A woven, uncoated polyethylene terephthalate (PET) vessel prosthesis was used. The coating process was carried out in a low-pressure plasma reactor in a multi-step process. After preparation of the vacuum chamber hexamethyldisiloxane (HDMSO) with oxygen was evaporated using argon plasma. By this an approx. 1 nm thin adhesion promoter layer was separated from plasma and HMDSO. The silicone oxide barrier layer was applied to the PET vessel samples. The carbon content of the layer could be selectively altered by changing the HMDSO oxygen flow ratio, resulting in coatings of 100 nm, 500 nm, and 1,000 nm. In addition, two different oxygen-to-HMDSO ratios were used. To achieve a carbon coating as low as possible, the ratio was set to 200:1. A carbon-rich layer was obtained with the 1:1 setting. The various coatings were then examined for their surface texture by scanning electron microscopy (SEM) as well as by cell culture experiments for cell viability and growth using EA.hy 926 cells.

Results

SEM showed no changes in the surface morphology; however a layer thickness of 1,000 nm showed peeled off coating areas. Alamar blue assays showed a significantly higher metabolic activity (p=0.026) for the coating 500 nm, ratio 200:1 compared to untreated control samples and a significantly lower metabolic activity (p=0.037) of the coating 500 nm, ratio 1:1 compared to the coating 500 nm, ratio 200:1. This underlines the apparent tendency of the 1:1 coating to inhibit the metabolic activity of the cells, while the 200:1 coating increases the activity. Fluorescence microscopy after calcein acetoxymethyl ester (AM) staining showed no significant difference between the different coatings and the uncoated PET material. However, a tendency of the increased surface growth on the coating 500 nm, ratio 200:1, is shown. The coatings with the ratio 1:1 tend to be less densely covered.

Conclusions

The results of this work indicate a great potential in the silicon coating of vascular prosthesis material. The plasma coating can be carried out easy and gently. Cell culture experiments demonstrated a tendency towards better growth of the cells on the 200:1 ratio coating and a poorer growth on the carbon-rich coating 1:1 compared to the uncoated material. The coating with silicon oxide with a thickness of 500 nm and an oxygen-HMDSO ratio of 200:1, a particularly low-carbon layer, appears to be a coating, which should therefore be further investigated for its effects on thrombogenicity and intimal hyperplasia.

[Change of perception of aged male attractiveness by conventional or male facelift: 3D simulation study of a new facelift concept for men]

BACKGROUND

 Facelift is now the fourth most common aesthetic procedure in men. Facial ageing is very different in men and women. Therefore, individual techniques are used since a uniform concept for the surgical facelift in men does not exist. This study aims to evaluate a gender-specific facelift concept especially developed for men.

MATERIAL AND METHODS

 Women and men (n = 10 each) were subjected to a three-dimensional face scan and a subsequent simulation of a V-shaped lift vector (standard lift) and a new facelift concept especially for men in a double T shape (male lift). In an online survey with 262 participants, the simulated as well as the unchanged images were presented and the attributes masculinity, femininity, attractiveness and youthfulness were queried. Statistical models were used to identify attributes of lifting as well as other factors and differences between the simulations.

RESULTS

 Facelift changes are generally associated with a significant improvement in the attributes of youthfulness and attractiveness compared with unchanged control faces. As expected, a male lift leads to masculinisation, while a standard lift leads to feminisation, regardless of the sex of the subjects. The male lift led to higher values for the attribute attractiveness in male subjects, as did the standard lift in female subjects. The standard lift developed for women is indeed more suitable for women and is associated with a significantly higher probability for the attribute youthfulness, whereas this is not the case in the newly introduced male lift concept.

CONCLUSION

 The new facelift concept for male patients is significantly associated with masculinity and attractiveness, while the standard lift suitable for women is associated with significantly higher evaluations of femininity and youthfulness. The results of the SIMALIFT study are the first evidence of the need for a more differentiated, gender-specific approach to facelifting.

Panta Rhei: Neovascularization, Angiogenesis and Nutritive Perfusion in Wound Healing

BACKGROUND

In response to tissue damage, angiogenesis is an extremely dynamic process that is finely regulated by signals from cells, the surrounding extracellular matrix (ECM), and derived mediators. As the only process, angiogenesis remains of decisive importance in the context of the entire wound healing process and is subject to constant change. The dissolution of the endothelial basement membrane, the migration of endothelial cells, and the development of new capillary vessels during wound healing depend not only on the cells and cytokines present, but also on the production and organization of ECM components in the immediate wound.

SUMMARY

Angiogenesis in wound healing can be divided into two main phases. During the pro-angiogenic phase at the beginning of wound healing, excessive neo-formation of blood vessels, some of which are poorly differentiated, occurs, which restore blood flow and thus nutritive perfusion as quickly as possible. This is followed by an anti-angiogenic phase in which the initially established vascular network undergoes a maturing process, which, however, is accompanied by a significant reduction in the number of vessels. Key Messages: Although many mechanisms and specific cell functions in wound healing have already been described, many underlying pathophysiological processes remain unknown. Because angiogenesis and its maturation is a very fast but also very long-lasting process, the understanding of the underlying mechanisms is of crucial importance. This article will give an overview of the current understanding and controversy in this sub-step of wound healing.

In-vivo monitoring of infection via implantable microsensors: a pilot study

The most common complication after implantation of foreign material is infection, leading to implant failure and severe patient discomfort. Smoldering-infections proceed inapparently and might not get verified by radiological diagnostics. Early identification of this type of infection might significantly reduce the rate of complications. Therefore, we manufactured a microsensor strip in a hybrid of thin-film and laminate technology in a wafer-level process. It comprises electrochemical, amperometric microsensors for glucose, oxygen and lactate as well as an integrated reference electrode. Microsensors have been implanted in the mouse dorsal skin fold chamber, which got inoculated with a human-pathogen bacterial strain. A selective signal could be measured for all parameters and time points. The infection led to measurable changes of the wound environment as given by a decrease of the oxygen- as well as the glucose-concentration while the lactate concentration increased markedly over time. The given results in this study are the first hints on a promising new tool and should therefore be interpreted as a proof of the principle to show the functionality of the microsensors in an in vivo setting. These microsensors could be used to monitor smoldering infections of implantable foreign materials reducing foreign implant associated complications.

A Novel Technique for the Standardized Application of Shock Waves in Experimental Research: The Diver Box

The Diver Box is designed to prevent impedance differences, energy loss or damage to neighboring structures caused by the use of shock waves with application gels. The Diver Box is an acrylic glass container filled with tempered water and includes a coupling membrane to prevent the impedance jump from air to water and to avoid the continuous propagation of shock waves into the tissue, maintaining wave dynamics. Different modes of extracorporeal shock waves can be applied to a mouse skin wound without energy loss and protected from harmful phase-reversed waves. Macroscopic changes were seen in only 5% to 12% of tested specimens. Hazardous phase reversal, back reflection and mechanical tissue damage can be avoided by use of the Diver Box, ensuring standardized extracorporeal shock wave application.

[The scaphoid fracture : Between pseudoarthrosis and possible anatomical variance]

The diagnosis of a scaphoid fracture, especially in the differentiation of a fresh fracture, the nonunion or a possible anatomical norm variant, can be difficult. We report on two patients who presented with stress-related, radiocarpal pain in our department. In both cases, radiological abnormalities were observed in the scaphoideal area, with a scaphoideum bipartitum on both sides, as well as an approximately 25-year-old scaphoid pseudarthrosis.

Localized eosinophilic fasciitis (Shulman's disease) as a differential diagnosis of nerve compression syndrome

A 46-year-old man presented with clinical signs of nerve compression syndrome of his right ulnar nerve as confirmed by nerve conduction studies. Unexpectedly, clinical examination and magnetic resonance imaging (MRI) revealed a subcutaneous tumor of 5×2 cm above the ulnar groove. Surgical exploration and histopathology of biopsies demonstrated the nerve distended and entrapped into an eosinophilic, inflammatory tissue. This rare condition is consistent with localized eosinophilic fasciitis, with no systemic manifestations. There are reports of isolated forearm versions of the disease. However, none occurred with the entrapment of a peripheral nerve appearing as a peripheral nerve tumor, yet. Consequentially, the presented patient would not have benefitted from further surgical neurolysis or tumor debulking, as eosinophilic fasciitis is an inflammatory and systemic disease. The patient’s symptoms decreased spontaneously after 4 weeks of postsurgical treatment, including nonsteroidal anti-inflammatory drugs (NSAIDs). Altogether, this case proved the necessity to regard even rare diseases as a potential cause of entrapment of peripheral nerves. This should lead surgeons to critical, differential diagnostic thinking and suggest that systemic diseases may be encountered during surgery due to their capability to mimic peripheral nerve tumors.

Skin Wound Healing: An Update on the Current Knowledge and Concepts

BACKGROUND

The integrity of healthy skin plays a crucial role in maintaining physiological homeostasis of the human body. The skin is the largest organ system of the body. As such, it plays pivotal roles in the protection against mechanical forces and infections, fluid imbalance, and thermal dysregulation. At the same time, it allows for flexibility to enable joint function in some areas of the body and more rigid fixation to hinder shifting of the palm or foot sole. Many instances lead to inadequate wound healing which necessitates medical intervention. Chronic conditions such as diabetes mellitus or peripheral vascular disease can lead to impaired wound healing. Acute trauma such as degloving or large-scale thermal injuries are followed by a loss of skin organ function rendering the organism vulnerable to infections, thermal dysregulation, and fluid loss.

METHODS

For this update article, we have reviewed the actual literature on skin wound healing purposes focusing on the main phases of wound healing, i.e., inflammation, proliferation, epithelialization, angiogenesis, remodeling, and scarring.

RESULTS

The reader will get briefed on new insights and up-to-date concepts in skin wound healing. The macrophage as a key player in the inflammatory phase will be highlighted. During the epithelialization process, we will present the different concepts of how the wound will get closed, e.g., leapfrogging, lamellipodial crawling, shuffling, and the stem cell niche. The neovascularization represents an essential component in wound healing due to its fundamental impact from the very beginning after skin injury until the end of the wound remodeling. Here, the distinct pattern of the neovascularization process and the special new functions of the pericyte will be underscored. At the end, this update will present 3 topics of high interest in skin wound healing issues, dealing with scarring, tissue engineering, and plasma application.

CONCLUSION

Although wound healing mechanisms and specific cell functions in wound repair have been delineated in part, many underlying pathophysiological processes are still unknown. The purpose of the following update on skin wound healing is to focus on the different phases and to brief the reader on the current knowledge and new insights. Skin wound healing is a complex process, which is dependent on many cell types and mediators interacting in a highly sophisticated temporal sequence. Although some interactions during the healing process are crucial, redundancy is high and other cells or mediators can adopt functions or signaling without major complications.

[Assessment of the significance and the requirements of medical postdoctoral lecture qualifications in Germany by the assessment committees]

OBJECTIVE

The postdoctoral medical lecture qualification (Habilitation) represents the highest academic qualification in Germany, which is successfully completed by approximately 850 candidates in medicine and health sciences per year. However, there is only a limited number of respective academic positions available. In addition, structures in education and society have changed over the last years, challenging the importance of this specific German qualification. The aim of this study was to elicit the opinions of members of German habilitation committees concerning the requirements, processes and the overall importance of the postdoctoral medical lecture qualification. Furthermore we wanted to evaluate potential needs for reforms.

METHODS

The online survey was conducted asking for biographic parameters, subjective ratings and potential needs for reforms concerning the postdoctoral medical lecture qualification (PLQ).

RESULTS

The PLQ was rated high in significance by 71.3 % of the committee members. According to the medical understanding of the Humboldt triad (research, teaching, patient care), research (94.3 %) and teaching (89.7 %) have been rated as the most important requirements for a PLQ. Asked for the motivation to undertake a PLQ, 91.0 % of the members gave the joy of doing research, 78.2 % the joy of teaching and 65.5 % better career prospects perspectives as their reason. The recognition of a Ph.D. degree as being equivalent to a German PQL was clearly rejected by the survey respondents (58.6 %: no equivalence). The majority is against the abolition of the German PLQ. However, there is a definite desire for reform, preferably concerning internal obstacles such as the dependence on full professors, more transparency in the PLQ process, but also the demand for a federal standard PLQ regulation.

CONCLUSION

From the committee members' point of view the German PLQ has still a role to play and, despite controversy, is still regarded as a timely qualification. However, there is clear-cut evidence for local, national and international reforms in order to create equality of opportunity for the candidates and to open up suitable career options.

[The medical dissertation in Germany : A quantitative analysis of promotion regulations in medical faculties]

BACKGROUND

The medical dissertation represents an independently processed scientific project. In the field of medicine this has for many years displayed the basis for controversial discussions. The aim of the study presented here was to evaluate the prerequisites of all current promotion regulations in German medical faculties in order to develop a comparability on the basis of a scoring system.

METHOD

An independent analysis of all promotion regulations from German medical faculties for the year 2014 was carried out according to 12 primary outcome measures and a scoring system.

RESULTS

The average total score of promotion regulations at 37 German medical faculties was 57.2 points (SD ±9.5) out of a possible 100 scoring points. The highest scores with 72-85 points were achieved by 3 faculties and 5 achieved scores of only 42-45 points. The range of the different criteria tested was broad. While the written thesis, the review process, the examination requirements as well as the grading of the thesis were defined in all regulations, the introduction into good clinical practice, knowledge of methodology as well as a check for plagiarism only seem to play minor roles.

CONCLUSION

The promotion regulations at German medical faculties show a great variation using the scoring system presented here for the first time. Standardized federal promotion regulations might help to establish a structured transparency as well as a national equality of opportunity.

Salinomycin increases chemosensitivity to the effects of doxorubicin in soft tissue sarcomas

Background

Chemotherapy for soft tissue sarcomas remains unsatisfactory due to their low chemosensitivity. Even the first line chemotherapeutic agent doxorubicin only yields a response rate of 18-29%. The antibiotic salinomycin, a potassium ionophore, has recently been shown to be a potent compound to deplete chemoresistant cells like cancer stem like cells (CSC) in adenocarcinomas. Here, we evaluated the effect of salinomycin on sarcoma cell lines, whereby salinomycin mono- and combination treatment with doxorubicin regimens were analyzed.

Methods

To evaluate the effect of salinomycin on fibrosarcoma, rhabdomyosarcoma and liposarcoma cell lines, cells were drug exposed in single and combined treatments, respectively. The effects of the corresponding treatments were monitored by cell viability assays, cell cycle analysis, caspase 3/7 and 9 activity assays. Further we analyzed NF-κB activity; p53, p21 and PUMA transcription levels, together with p53 expression and serine 15 phosphorylation.

Results

The combination of salinomycin with doxorubicin enhanced caspase activation and increased the sub-G1 fraction. The combined treatment yielded higher NF-κB activity, and p53, p21 and PUMA transcription, whereas the salinomycin monotreatment did not cause any significant changes.

Conclusions

Salinomycin increases the chemosensitivity of sarcoma cell lines - even at sub-lethal concentrations - to the cytostatic drug doxorubicin. These findings support a strategy to decrease the doxorubicin concentration in combination with salinomycin in order to reduce toxic side effects.

Characteristics and differences in necrotizing fasciitis and gas forming myonecrosis: a series of 36 patients

BACKGROUND AND AIMS

Necrotizing fasciitis (NF) and gas forming myonecrosis (GFM), both being subtypes of necrotizing soft tissue infection (NSTI), are life threatening conditions sharing certain similarities. Despite the necessity of early and radical surgical debridement in necrotizing infections, the distinction between these entities is of clinical relevance since gas forming myonecrosis in a number of cases results from an underlying abdominal cause and the focus of infection can be missed. This study was to evaluate the incidence and risk factors as well as the mortality rate in patients with NSTI and GFM.

MATERIAL AND METHODS

All patients with NSTI treated in the authors' hospital between January 2005 and Decem-ber 2009 were enrolled in the study. Medical records, histological slides, microbiological and laboratory parameters as well as Computerized Tomography (CT) and magnetic resonance imaging (MRI) scans were reviewed for all patients. Differences between NF and GFM regarding hospital stay, number of surgical interventions and pre-existing comorbidities as well as mortality rate were analyzed. The laboratory risk factor for necrotizing fasciitis (LRINEC) score was calculated in all patients on admission.

RESULTS AND CONCLUSIONS

Thirty patients (17 female, 13 male) with necrotizing fasciitis with a mean age of 55 years (SD 15.5) were included in the study. There was no statistically significant difference between survivors and deceased patients comparing the LRINEC score (n.s.). Patients with necrotizing fasciitis secondarily involving the trunk had a significantly higher mortality rate (OR 11.2; 95% CI=1.7-72.3). In the majority of cases (12 cases), minor skin lesions were identified as the site of origin. Amongst all necrotizing soft tissue infections six patients (female n=3; male n=3) with a mean age of 61.5 years (SD 12.2) with non-clostridial gas forming myonecrosis were identified. Three patients had a history of malignancy and in three patients the infection was secondary to major surgery. The mean LRINEC score was 8.5 (SD 1). Three patients (50%) died due to GFM. Early diagnosis and appropriate intervention is critical to provide accurate treatment decisions. Eradicating the differing primary sources of infection in GFM and NF will have a positive impact on outcome.

Experimental murine model of primary high grade undifferentiated pleomorphic sarcoma not otherwise specified

BACKGROUND

Undifferentiated pleomorphic sarcoma not otherwise specified (NOS) is a malignant neoplasm of uncertain origin arising both in the soft tissue and the bone. The WHO classified this tumour in 2002 but controversy has plagued this entity due to limited availability of tissue for study. The aim of this study was to establish a reproducible xenograft model of primary human undifferentiated pleomorphic sarcoma NOS.

MATERIALS AND METHODS

Primary human sarcoma samples were divided into tumour fragments and transplanted subcutaneously in mice. Sarcoma xenografts were analysed histolomorphologically (light/electron-microscopy; immunohistochemistry).

RESULTS

All tumours resulted in viable sarcoma NOS xenografts demonstrating similar histological patterns. In both the original tumours and the xenografts, tumour necrosis was found ranging from 15% to 25%. The background stroma of the xenografts was hyalinised like the primary sarcoma. Electron microscopical analyses showed good maintenance of ultrastructure.

CONCLUSION

Implantation of intact tumor fragments yielded in a complete tumor take rate. The development of new cancer therapeutics requires animal models that closely resemble the human patient. This study provides ideal animal models for the research of pathogenesis and pathobiology of primary human undifferentiated pleomorphic sarcoma NOS.

Revascularization and tissue regeneration of an empty root canal space is enhanced by a direct blood supply and stem cells

BACKGROUND

Regenerative endodontics is an innovative treatment concept aiming to regenerate pulp, dentin and root structures. In the diseased or necrotic tooth, the limitation in vascular supply renders successful tissue regeneration/generation in a whole tooth challenging. The aim of this study is to evaluate the ability of vascularized tissue to develop within a pulpless tooth using tissue engineering techniques.

MATERIALS AND METHODS

A pulpless tooth chamber, filled with collagen I gel containing isolated rat dental pulp cells (DPC) and angiogenic growth factors, was placed into a hole created in the femoral cortex or into its own tooth socket, respectively. The gross, histological and biochemical characteristics of the de novo tissue were evaluated at 4 and 8 weeks post-transplantation.

RESULTS

Tooth revascularization and tissue generation was observed only in the femur group, confirming the important role of vascular supply in tissue regeneration. The addition of cells and growth factors significantly promoted connective tissue production in the tooth chamber.

CONCLUSION

Successful revascularization and tissue regeneration in this model demonstrate the importance of a direct vascular supply and the advantages of a stem cell approach.

Sarcoma cells induce alteration in adipogenic differentiation

BACKGROUND

Sarcomas consist of both tumor and stromal cells, and the interaction between these compartments is critical for tumor progression and metastasis. Tumor-derived factors may alter the differentiation capacity of the adjacent stromal cells. The aim of this study was to elucidate the paracrine impact of liposarcoma cells on pre-adipocytes, their adipogenic differentiation process and miRNA expression profile.

MATERIALS AND METHODS

3T3-L1 pre-adipocytes were exposed to sarcoma pre-conditioned media. Following induction of adipogenic differentiation morphometrical changes were assessed. Differences in miRNA expression of conditioned and non-conditioned 3T3-L1 cells were analyzed.

RESULTS

Exposure to sarcoma pre-conditioned media substantially altered the differentiation capability of 3T3-L1 pre-adipocytes. Significant changes in the miRNA expression profile between conditioned and non-conditioned pre-adipocytes were observed.

CONCLUSION

Sarcoma cells directly modulate pre-adipocyte differentiation. This study demonstrates that sarcoma cells influence differentiation of pre-adipocytes via paracrine factors and alter their miRNA expression.

The in vitro preconditioning of myoblasts to enhance subsequent survival in an in vivo tissue engineering chamber model

The effects of in vitro preconditioning protocols on the ultimate survival of myoblasts implanted in an in vivo tissue engineering chamber were examined. In vitro testing: L6 myoblasts were preconditioned by heat (42 °C; 1.5 h); hypoxia (<8% O(2); 1.5 h); or nitric oxide donors: S-nitroso-N-acetylpenicillamine (SNAP, 200 μM, 1.5 h) or 1-[N-(2-aminoethyl)-N-(2-aminoethyl)amino]-diazen-1-ium-1,2-diolate (DETA-NONOate, 500 μM, 7 h). Following a rest phase preconditioned cells were exposed to 24 h hypoxia, and demonstrated minimal overall cell loss, whilst controls (not preconditioned, but exposed to 24 h hypoxia) demonstrated a 44% cell loss. Phosphoimmunoblot analysis of pro-survival signaling pathways revealed significant activation of serine threonine kinase Akt with DETA-NONOate (p < 0.01) and heat preconditioning (p < 0.05). DETA-NONOate also activated ERK 1/2 signaling (p < 0.05). In vivo implantation: 100,000 preconditioned (heat, hypoxia, or DETA-NONOate) myoblasts were implanted in SCID mouse tissue engineering chambers. 100,000 (not preconditioned) myoblasts were implanted in control chambers. At 3 weeks, morphometric assessment of surviving myoblasts indicated myoblast percent volume (p = 0.012) and myoblasts/mm(2) (p = 0.0005) overall significantly increased in preconditioned myoblast chambers compared to control, with DETA-NONOate-preconditioned myoblasts demonstrating the greatest increase in survival (p = 0.007 and p = 0.001 respectively). DETA-NONOate therefore has potential therapeutic benefits to significantly improve survival of transplanted cells.

Surface modification by glow discharge gasplasma treatment improves vascularization of allogenic bone implants

Sufficient induction of blood vessel ingrowth decisively influence transplant functionality. In this study, microvascular response to transplants of surface modified bone substitutes were assessed in vivo. The surface modification of allogenic bone substitutes (dehydrated human femoral head) was achieved in a double-conductive low-pressure gasplasma reactor (Ar(2) /O(2) , 13.65 MHz, 1,000 W, 5 Pa). The modified bone substitutes (n = 10) as well as untreated bone substitutes serving as controls (n = 10) were placed into the dorsal skinfold chamber of female balb/c mice (n = 10). Dynamic assessment of microcirculatory parameters was performed using intravital fluorescence microscopy during an implantation period of 10 days. The angiogenic response was found markedly accelerated in gasplasma-treated bone. Compared to untreated implants, the gasplasma-activated bone substitutes showed significantly higher microvascular density on days 5 and 10. The quantification of the microvascular diameters, red blood cell velocity, and microvascular permeability displayed stable perfusion and vascular integrity of the newly developed blood vessels throughout the 10-day observation period. The surface activation via cold low-pressure glow discharge gasplasma supports the vascular integration of allogenic bone by earlier induction of the angiogenesis.

Leiomyosarcoma of intravascular origin--a rare tumor entity: clinical pathological study of twelve cases

Background

Leiomysarcoma of intravascular origin is an exceedingly rare entity of malignant soft tissue tumors. They are most frequently encountered in the retroperitoneum arising from the inferior vena cava and are scarcely found to arise from vessels of the extremities. These tumors were analysed with particular reference to treatment outcome and prognosis. The aim of this article is to broaden the knowledge of the clinical course of this rare malignancy.

Method

During 2000 and 2009 twelve patients were identified with an intravascular origin of a leiomyosarcoma. Details regarding the clinical course, follow-up and outcome were assessed with focus on patient survival, tumor relapse and metastases and treatment outcome. 3 year survival probability was calculated using Kaplan-Meier method.

Results

Vascular leiomyosarcomas accounted for 0.7% of all malignant soft tissue tumors treated at our soft tissue sarcoma reference center. The mean follow up period was 38 months. Tumor relapse was encountered in six patients. 6 patients developed metastatic disease. The three year survival was 57%.

Conclusion

Vascular leiomysarcoma is a rare but aggressive tumor entity with a high rate of local recurrence and metastasis.

Vascularized tissue engineering mouse chamber model supports thymopoiesis of ectopic thymus tissue grafts

We have previously established a chamber model of tissue engineering that promotes de novo angiogenesis and vascularization of engrafted cells and tissues when combined with an extracellular matrix. Here we demonstrate that the mouse chamber (MC) model can sustain ectopic grafts of murine fetal thymus lobes and, to a limited degree, human pediatric thymus tissue, resulting in de novo T-cell production. Silicone chambers containing Matrigel((R)) and thymus tissues were placed around exposed epigastric vessels and the ends sealed with bone wax, before implantation into the inguinal fat pad of athymic Balb/c(nu/nu) (nude) mice. Murine, embryonic day 15 (E15) thymus grafts were found to be well vascularized and viable within the MC upon harvest at week 11. In contrast, engraftment of both adult murine and pediatric human thymus tissue was limited, with only one out of the seven human thymus grafts sustaining mature, murine-derived T-cell development. Increased CD4(+) and CD8(+) T-cell numbers were observed in the peripheral blood of nude mice within 2 weeks after E15 thymus-MC grafts (n = 8), compared with nude control mice. Peripheral blood T-cell percentage and subset distribution were comparable to mice receiving conventional thymus kidney capsule grafts. T-cell function of both kidney capsule- and MC-E15 thymus grafts was established via successful rejection of major histocompatibility complex (MHC)-mismatched skin grafts. Sustained growth of fetal thymus tissue in the MC provides an alternative model for the study of thymopoiesis and related applications of T-cell-mediated immunity.

Disparate companions: tissue engineering meets cancer research

Recreating an environment that supports and promotes fundamental homeostatic mechanisms is a significant challenge in tissue engineering. Optimizing cell survival, proliferation, differentiation, apoptosis and angiogenesis, and providing suitable stromal support and signalling cues are keys to successfully generating clinically useful tissues. Interestingly, those components are often subverted in the cancer setting, where aberrant angiogenesis, cellular proliferation, cell signalling and resistance to apoptosis drive malignant growth. In contrast to tissue engineering, identifying and inhibiting those pathways is a major challenge in cancer research. The recent discovery of adult tissue-specific stem cells has had a major impact on both tissue engineering and cancer research. The unique properties of these cells and their role in tissue and organ repair and regeneration hold great potential for engineering tissue-specific constructs. The emerging body of evidence implicating stem cells and progenitor cells as the source of oncogenic transformation prompts caution when using these cells for tissue-engineering purposes. While tissue engineering and cancer research may be considered as opposed fields of research with regard to their proclaimed goals, the compelling overlap in fundamental pathways underlying these processes suggests that cross-disciplinary research will benefit both fields. In this review article, tissue engineering and cancer research are brought together and explored with regard to discoveries that may be of mutual benefit.

Plastic Surgery Management of Soft Tissue Loss in Meningococcal Septicemia

Soft tissue necrosis associated with meningococcemia is a major challenge for any pediatric plastic surgery service. Records of patients treated by the Department of Plastic and Maxillofacial Surgery, Royal Children's Hospital, Melbourne, Australia, were reviewed. Two hundred fifty patients were treated for meningococcemia at our institution over a 40-year period. Of these, 31 patients suffered soft tissue necrosis. Three groups were identified: lesions that healed with nonoperative management (n = 12); those that required skin grafting, flaps, or minor amputations (n = 14); and those requiring major amputations (n = 5). When compared with a comparable control group of patients with documented meningococcemia who did not suffer tissue loss (n = 35), the best predictors for requiring surgery were the presence of metabolic acidosis on admission (P < 0.0005) and a progressive thrombocytopenia (P < 0.0005). Metabolic acidosis and progressive thrombocytopenia are predictive of the need for surgery for tissue loss and underline the evolving thrombotic nature of the disease.