Synergistic effects of imatinib and carboplatin on VEGF, PDGF and PDGF-Rα/ß expression in squamous cell carcinoma of the head and neck in vitro

Head and neck squamous cell carcinoma (HNSCC) is an aggressive epithelial malignancy. The development of new treatment modalities in order to improve long-term survival of patients with HNSCC is imperative. Numerous studies have demonstrated that carcinogenesis and tumor cell dissemination is influenced by the tumor microenvironment. The protein-kinase-receptors (PTKs) are essential elements of the intracellular signal transduction pathway and regulate cell growth, development and apoptosis. Cell proliferation, migration, induction of tumor vascularization and carcinogenesis, invasion is regulated by a variety of angiogenic factors, such as PDGF (platelet-derived growth factor), VEGF (vascular endothelial growth factor) and their respective tyrosine kinase receptors (PDGF-R and VEGF-R). They present promising targets for anti-cancer therapy through abrogation of impaired signaling pathways. Indeed, imatinib, a small molecule drug targeting these protein kinases, has antiproliferative effects in several cancer types. The purpose of this study was to investigate the potential synergism of imatinib and carboplatin on the expression of PDGF, PDGF-R α/ß and VEGF in different HNSCC cell lines. Several tumor cell lines were subjected to increasing concentrations of carboplatin (3 and 7.5 µmol/l) and imatinib (18 and 30 µmol/l) and ELISA, immunohistochemical methods and RQ-PRC after 48, 72, 120 and 240 h were used to assess their expression levels. While PDGF-Rα/ß expression was unimpaired at lower imatinib concentrations (18 µmol/l), PDGF-Rα/ß expression was suppressed at 30 µmol/l, and suppression was enhanced by the presence of carboplatin. By RQ-PCR, a significant reduction of PDGF-Rα/ß expression was detected (p<0.5). We observed explicit significant reduction in VEGF levels with increasing concentrations of imatinib and with the combination of the two chemotherapeutic drugs (p<0.5). We report for the first time evidence of synergism of imatinib and carboplatin in suppressing VEGF, PDGF and PDGF-Rα/ß expression in HNSCC.

TGF-ß1 antisense impacts the SMAD signalling system in fibroblasts from keloid scars

AIM

To identify the effect of a TGF-β1 antisense treatment of keloid fibroblasts on the SMAD signalling system.

MATERIAL AND METHODS

In this cross-sectional study, keloid and adjacent healthy tissue was harvested from 9 patients with keloid scars after otoplasty. Keloid fibroblasts were placed in monolayer cultures. Expression of SMAD2, -3, -4, -6, and SMURF2 were analysed by immunohistochemistry. Analysis of treatment with antisense oligonucleotides was conducted by immunohistochemistry, and RT-PCR.

RESULTS

Immunohistochemical investigation demonstrated increased expression of SMAD2, -3 and -4, and decreased expression of SMURF2. TGF-β1 antisense therapy significantly down-regulated SMAD2 and SMAD4, up-regulated SMURF2 and showed no effect on SMAD3 and SMAD6.

CONCLUSION

TGF-β1 led to elevated levels of the SMAD signalling cascade, indicating an abnormal sensitivity of keloid-derived fibroblasts to this cytokine. Abrogation correlated with potential suppression of the fibro-proliferative progress. There is growing evidence for an abnormal response to this cytokine in the intracellular signal transduction in keloid-derived fibroblasts.

Effect of transforming growth factor-beta1 antisense oligonucleotides on matrix metalloproteinases and their inhibitors in keloid fibroblasts

OBJECTIVE

To identify changes in the expression of matrixmetalloproteinases (MMPs) and their specific inhibitors tissue inhibitors of metalloproteinases (TIMPs) after targeting of transforming growth factor-beta1 (TGF-beta1) with antisense oligonucleotides.

STUDY DESIGN

Cross-sectional study.

SETTING

The study was performed on tissue samples from nine patients with keloid scars after otoplasty presenting to the Otolaryngology-Head and Neck Surgery Department of the University Hospital in Mannheim, Germany.

SUBJECTS AND METHODS

Keloid fibroblasts and normal fibroblasts were harvested from auricular keloid scars and healthy skin regions of the same patients during resection procedure of the keloid. Cells were placed in monolayer cultures. Expression of MMPs and TIMPs were analyzed by immunohistochemistry. The effect of TGF-beta1 targeting using antisense oligonucleotides on the expression of both protein groups in keloid-derived fibroblasts was analyzed by enzyme-linked immunosorbent assay and reverse-transcription polymerase chain reaction.

RESULTS

Immunohistochemical investigation demonstrated increased expression of MMP-2, -3, -9, and -13 and TIMP-1 and -2. TGF-beta1 antisense therapy significantly down-regulated MMP secretion in vitro.

CONCLUSION

Usage of TGF-beta1 antisense oligodeoxynucleotides (ODNs) may show a potential chemopreventive or therapeutic option for keloids by blocking the effect of TGF-beta1. Furthermore, antisense ODNs can be used as an investigative approach toward a better understanding of molecular mechanisms in keloid pathophysiology.

Keloids: current concepts of pathogenesis (review)

Excess scar formation occurs after dermal injury as a result of abnormal wound healing. Hypertrophic scars and keloids both represent fibrotic skin conditions which can be very difficult, even frustrating, to treat. Identification of differences between hypertrophic scars, keloids and normal scars are a prerequisite for finding the correct therapeutical concept. Despite the relatively high prevalence of keloids in the general population, the mechanisms underlying keloid formation are only partially understood. This fact is reflected in the multiple treatment modalities, of which no single treatment has proven to be widely effective. Advances in our understanding of the wound healing process reveal new pathophysiological concepts for keloid formation. Our article presents an overview on physiological wound healing and the pathogenesis of scar formation, differentiates keloids from hypertrophic scars and reviews current hypotheses for keloid formation. This information might assist in deciphering the complexity of keloid pathogenesis and help in the development of an efficacious therapeutical strategy.

Mutation analysis of "Endoglin" and "Activin receptor-like kinase" genes in German patients with hereditary hemorrhagic telangiectasia and the value of rapid genotyping using an allele-specific PCR-technique

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome, is an autosomal dominant disorder which is clinically characterised by recurrent epistaxis, mucocutaneous telangiectasia and visceral arteriovenous malformations. Genetic linkage studies identified two genes primarily related to HHT: endoglin (ENG) on chromosome 9q33-34 and activin receptor-like kinase1 (ACVRL1) on chromosome 12q13. We have screened a total of 41 unselected German patients with the suspected diagnosis of HHT. Mutation analysis for the ENG and ACVRL1 genes in all patients was performed by PCR amplification. Sequences were then compared to the HHT database http://www.hhtmutation.org sequences of the ENG mRNA (accession no. BC014271.2) and the ACVRL1 mRNA (accession no. NM000020.1).

RESULTS

We identified 15 different mutations in 18 cases by direct sequencing. Among these mutations, one novel ENG mutation could be detected which has not yet been described in the literature before. The genotype-phenotype correlation was consistent with a higher frequency of pulmonary arteriovenous malformations in patients with ENG mutations than in patients with ACVRL1 mutations in our collective.

CONCLUSION

For rapid genotyping of mutations and SNPs (single nucleotide polymorphisms) in ENG and ACVRL1, allele-specific PCR methods with sequence-specific primers (PCR-SSP) were established and their value analysed.

Lymphatic vessel density in correlation to lymph node metastasis in head and neck squamous cell carcinoma

BACKGROUND

In head and neck squamous cell carcinoma (HNSCC), metastatic dissemination to regional lymph nodes serves as a major prognostic indicator for incipient disease progression and constitutes the guideline for subsequent therapeutic strategies. In this study, whether intratumoral (IT) and peritumoral (PT) lymphatic vessel density (LVD) might be a predictive indicator to the risk of lymph node metastasis was investigated.

PATIENTS AND METHODS

Tumour lymph vessels in fresh frozen sections of 105 head and neck cancer were quantified by immunostaining for the lymphatic endothelial marker LYVE-1. These results underwent correlation with the nodal status of the patient.

RESULTS

There was a significant relationship between a high IT LVD and nodal metastasis (N+) (p=0.049, Mann-Whitney test). Analysed separately by anatomic regions, a significant correlation was only shown in oral carcinoma (p=0.032, Mann-Whitney test). Intratumoral LVD was lower compared to peritumoral LVD. Logistic regression, however, showed that the only predictive parameter for the nodal status was the localisation of the primary tumour but not LVD.

CONCLUSION

This study confirmed that IT LVD is low in HNSCC. In this group of tumours there was a significant correlation between IT LVD and nodal involvement.

The platelet-derived growth factor receptor as a target for vascular endothelial growth factor-mediated anti-angiogenetic therapy in head and neck cancer

Inhibition of angiogenesis by blocking angiogenic cytokines or their pathways has become a major target in experimental cancer therapies. This therapeutical approach requires a profound knowledge of growth factor profiles that contribute to tumor growth and progression. The respective knowledge is presently rather incomplete for head and neck squamous cell carcinomas (HNSCC). Therefore we studied the serum levels and expression of platelet-derived growth factor (PDGF) in HNSCC patients and in cell culture as well as the effect of a PDGF-receptor (PDGF-R) inhibition by Imatinib (Gleevec, STI571) on the secretion and expression activity of PDGF and vascular endothelial growth factor (VEGF) by postulating there is a correlation between the PDGF and VEGF networks. PDGF levels in patients with HNSCC, PDGF and VEGF secretion by HNSCC cells, were measured by ELISA, expression of PDGF and VEGF by RT-PCR. We found significantly increased PDGF levels in HNSCC patients' sera as well as in HNSCC cell lines. Treatment of the cell lines with Imatinib, a partially selective PDGF-R inhibitor, resulted in reduced secretion of PDGF and VEGF. This inhibiting effect was also reflected on the expression level of VEGF. In conclusion, the present study confirms the crucial role of PDGF in HNSCC growth and strongly suggests a correlation between the PDGF/PDGF-R and VEGF/VEGF-R pathway networks in HNSCC. Although further studies must be performed for a more complete understanding of this interaction, a targeting therapy for the inhibition of PDGF-R tyrosine phosphorylation by Imatinib may be a promising strategy for future tumor therapy by autocrine and paracrine inhibition of tumor growth and angiogenesis, presumably through simultaneous down-regulation of PDGF and VEGF.

Does the genotype of HHT patients with mutations of the ENG and ACVRL1 gene correlate to different expression levels of the angiogenic factor VEGF?

The aim of this study was to determine in what way HHT (hereditary hemorrhagic telangiectasia) patients with mutations for the endoglin (ENG) or activin receptor-like kinase 1 (ACVRL1) gene show different expression levels of the angiogenic factor VEGF (vascular endothelial growth factor) by correlating VEGF to the HHT genotype. In 18 HHT patients, who were screened for ENG and ACVRL1 gene mutations and 25 healthy controls the VEGF plasma level as well as the VEGF tissue expression were determined by ELISA technique and cryostat sections of the nasal mucosa. In general, the VEGF plasma levels as well as the VEGF tissue expression were significantly higher in HHT patients compared to healthy controls. However, the correlation of VEGF to the HHT genotype did not show any significant differences, i.e. the VEGF plasma levels as well as the VEGF tissue expression in HHT patients with ENG gene mutations did not differ significantly to those of HHT patients with ACVRL1 gene mutations or mutations for both the genes. In spite of the fact that the angiogenic factor VEGF seems to play an important role in the pathogenesis of HHT, it cannot serve as a specific diagnostic screening marker. These results underline the importance and necessity of molecular analyses in HHT patients.

Abrogation of TGF-beta by antisense oligonucleotides modulates expression of VEGF and increases angiogenic potential in isolated fibroblasts from radiated skin

The transforming growth factor-beta (TGF-beta) has been identified as an important component of wound healing. Recent developments in molecular therapy offer good prospects for the modulation of wound healing, specifically those targeting TGF-beta. The aim of this study was to analyze the effect of TGF-beta targeting on the expression of angiogenic vascular endothelial growth factor (VEGF), a key regulator of angiogenesis and in vitro angiogenic activity in fibroblasts isolated from radiation-induced chronic dermal wounds. The expression of angiogenic VEGF in tissue samples from radiation-induced chronic dermal wounds was investigated by immunohistochemistry and microarray technique. The effect of TGF-beta targeting using antisense oligonucleotides on the expression of VEGF in isolated fibroblasts was analyzed by ELISA and multiplex RT-PCR. Human endothelial cells (ECs) were grown in conditioned medium produced from the treated fibroblasts. EC migration was measured using a modified Boyden chamber; EC tube formation was analyzed under a light microscope. Immunohistochemical investigation and microarray analysis demonstrated a decreased expression of VEGF protein and mRNA in tissue samples from radiation-induced chronic dermal wounds compared to normal human skin. Antisense TGF-beta oligonucleotide treatment significantly up-regulated VEGF secretion in vitro. Addition of conditioned medium from TGF-beta antisense-treated fibroblasts resulted in an increase in EC cell migration and tube formation. In conclusion, our results demonstrate that TGF-beta antisense oligonucleotide technology may be a potential therapeutic option for stimulation of angiogenesis in radiation-induced dermal wounds.

TGF-beta1 antisense therapy modulates expression of matrix metalloproteinases in keloid-derived fibroblasts

Transforming growth factor-beta1 (TGF-beta1) has been identified as an important regulator of wound healing. Recent developments in molecular therapy offer exciting prospects for the modulation of wound healing, specifically those targeting TGF-beta1. The purpose of this study was to analyze the effect of TGF-beta1 targeting on the expression of matrix metalloproteinases (MMPs) in fibroblasts cultured from earlobe keloids. The expression of MMP-2 and -9 in tissue samples from keloids was investigated by immunohistochemistry. The effect of TGF-beta1 targeting using antisense oligonucleotides on the expression of MMPs in keloid-derived fibroblasts was analysed by ELISA and multiplex RT-PCR. Immunohistochemical studies demonstrated an increased expression of MMP protein in tissue samples from keloids compared to normal human skin. Antisense TGF-beta1 oligonucleotide treatment significantly downregulated MMP-9 secretion in vitro. In conclusion, TGF-beta1 antisense oligonucleotide technology may be a potential therapeutic option for the inhibition of proteolytic tissue destruction in keloids.

Skeletal Muscle Regeneration: MSC versus Satellite Cells

Problem

Differentiating stem cells into the myogenic linage in order to create functional muscle tissue is a challenging endeavour. In this work, adipose-derived mesenchymal stem cells (MSC) and satellite cells derived from muscle biopsies were compared regarding proliferation and myogenic differentiation potential under standardized cell culture conditions. This data was obtained in order to discover the most promising type of stem cell for regeneration of muscle tissue and to determine the optimal culture conditions for later clinical use.

Methods

Human MSC were isolated from adipose tissue, and primary human skeletal myoblasts were extracted from muscle biopsies by enzymatic digestion. Proliferation was analysed using the AlamarBlue® assay. Gene expression of marker genes – such as Myogenin, Myo D, Myf 5 and MHC – were analysed by RT-PCR. Immunostainings against desmin and sarcomeric-actin were performed as differentiation markers.

Results

MSC cell cultures showed a greater proliferation rate compared with satellite cell cultures. In both stem cell cultures, myogenic differentiation/heritage could be verified by immunostainings against the muscle-specific marker desmin. Gene expression and protein analysis revealed a more stable differentiation of human satellite cell cultures.

Conclusion

Characterization of both human MSC cultures and satellite cell cultures – and thereby an understanding of myogenesis – might lead to their clinical usage in skeletal muscle tissue engineering. The results in this study appear to indicate that human satellite cell cultures have a more stable differentiation under in vitro conditions and that they might offer a greater potential for skeletal muscle tissue engineering purposes.

Significance

Our study contributes to the understanding of myogenic differentiation of MSC and satellite cells and helps to improve culture systems for later clinical utilization.

Integrin expression in stem cells from bone marrow and adipose tissue during chondrogenic differentiation

The use of adult mesenchymal stem cells (MSC) in cartilage tissue engineering offers new perspectives in the generation of transplants for reconstructive surgery. The extracelular matrix (ECM) plays a key role in modulating the function and phenotype of the embedded cells and contains the integrins as adhesion receptors mediating cell-cell and cell-matrix interactions. In our study, characteristic changes in integrin expression during the course of chondrogenic differentiation of MSC from bone marrow and adipose tissue were compared. MSC were isolated from bone marrow biopsies and adipose tissue. During cell culture, chondrogenic differentiation was performed. The expression of integrins and their signaling components were analysed with microarray and immunohistochemistry in freshly isolated MSC and after chondrogenic differentiation. The fibronectin receptor (integrin alpha5beta1) was expressed by undifferentiated MSC, and expression rose during chondrogenic differentiation in both types of MSC. The components of the vitronectin/osteopontin receptors (alphavbeta5) were not expressed by freshly isolated MSC, and expression rose with ongoing differentiation. Receptors for the collagens (alpha1beta1, alpha2beta1, alpha3beta1) were weakly expressed by undifferentiated MSC and were activated during differentiation. Intracellular signaling components integrin-linked kinase (ILK) and CD47 showed increased expression with ongoing differentiation. For all integrins, no significant differences were be found in the 2 types of MSC. Integrin-mediated signaling appeared to play an important role in the generation and maintenance of the chondrocytic phenotype during chondrogenic differentiation. Particularly, the receptors for fibronectin, vitronectin, osteopontin and the collagens may be involved in the generation of the ECM. Intracellularly, their signals might be transduced by ILK and CD47. To fully harness the potential of these cells, future studies should be directed to ascertain their cellular and molecular characteristics for optimal identification, isolation, and expansion.

TGF-beta antisense oligonucleotides modulate expression of matrix metalloproteinases in isolated fibroblasts from radiated skin

BACKGROUND

Transforming growth factor-beta (TGF-beta) has been identified as an important component of wound healing. Recent developments in molecular therapy offer exciting prospects for the modulation of wound healing, specifically those targeting TGF-beta. The purpose of this study was to analyze the effect of TGF-beta targeting on the expression of matrix metalloproteinases (MMPs) in fibroblasts isolated from radiation-induced chronic dermal wounds.

MATERIALS AND METHODS

The expression of MMPs in tissue samples from radiation-induced chronic dermal wounds was investigated by immunohistochemistry and microarray technique. The effect of TGF-beta targeting using antisense oligonucleotides on the expression of MMPs in isolated fibroblasts was analysed by ELISA and multiplex RT-PCR.

RESULTS

Immunohistochemical investigation and microarray analysis demonstrated an increased expression of MMP protein and mRNA in tissue samples from radiation-induced chronic dermal wounds compared to normal human skin. Antisense TGF-beta oligonucleotide treatment significantly down-regulated MMP secretion in vitro.

CONCLUSION

TGF-beta antisense oligonucleotide technology may be a potential therapeutic option for the inhibition of proteolytic tissue destruction in radiation-induced chronic wounds.

Characterization of human myoblast cultures for tissue engineering

Skeletal muscle tissue engineering, a promising specialty, aims at the reconstruction of skeletal muscle loss. In vitro tissue engineering attempts to achieve this goal by creating differentiated, functional muscle tissue through a process in which stem cells are extracted from the patient, e.g. by muscle biopsies, expanded and differentiated in a controlled environment, and subsequently re-implanted. A prerequisite for this undertaking is the ability to cultivate and differentiate human skeletal muscle cell cultures. Evidently, optimal culture conditions must be investigated for later clinical utilization. We therefore analysed the proliferation of human cells in different environments and evaluated the differentiation potential of different culture media. It was shown that human myoblasts have a higher rate of proliferation in the alamarBlue assay when cultured on gelatin-coated culture flasks rather than polystyrene-coated flasks. We also demonstrated that myoblasts treated with a culture medium with a high concentration of growth factors [growth medium (GM)] showed a higher proliferation compared to cultures treated with a culture medium with lower amounts of growth factors [differentiation medium (DM)]. Differentiation of human myoblast cell cultures treated with GM and DM was analysed until day 16 and myogenesis was verified by expression of MyoD, myogenin, alpha-sarcomeric actin and myosin heavy chain by semi-quantitative RT-PCR. Immunohistochemical staining for desmin, Myf-5 and alpha-sarcomeric actin was performed to verify the myogenic phenotype of extracted satellite cells and to prove the maturation of cells. Cultures treated with DM showed positive staining for alpha-sarcomeric actin. Notably, markers of differentiation were also detected in cultures treated with GM, but there was no formation of myotubes. In the enzymatic assay of creatine phosphokinase, cultures treated with DM showed a higher activity, evidencing a higher degree of differentiation. In this study, we obtained detailed information regarding the cultivation and differentiation of human myoblast cultures in different environments. By exploring optimal culture conditions for skeletal muscle tissue engineering, we acquired culture data for comparison with other sources of stem cells in order to find the most applicable stem cell for focussed clinical usage.

Tissue engineering in head and neck reconstructive surgery: what type of tissue do we need?

Craniofacial tissue loss due to congenital defects, disease or injury is a major clinical problem. The head and neck region is composed of several tissues. The most prevalent method of reconstruction is autologous grafting. Often, there is insufficient host tissue for adequate repair of the defect side, and extensive donor site morbidity may result from the secondary surgical procedure. The field of tissue engineering has the potential to create functional replacements for damaged or pathologic tissues.

[A comparison of the gene expression patterns of human chondrocytes and chondrogen differentiated mesenchymal stem cells for tissue engineering]

BACKGROUND

Tissue engineering is a promising method for the generation of chondrogenic grafts for reconstructive surgery. In cultured chondrocytes, the dedifferentiation of cells seems unavoidable for multiplication.

METHODS

In this study, we investigated the expression of distinct markers during the dedifferentiation of human chondrocytes (HC) harvested during septoplasty and human mesenchymal stem cells (hMSC) from cartilage biopsies in cell culture using the microarray technique.

RESULTS

The genes for collagen 1alpha1, 2alpha1, 3alpha1, 4alpha1, 11alpha1, biglycan, fibromodulin and lumican were activated during the dedifferentiation of the HCs, collagen 9alpha2, 9alpha3, 10alpha1 and chondroadherin were inactivated. During chondrogenic differentiation of hMSCs, the genes for collagen 3alpha1, 9alpha2, 9alpha3, 10alpha1, 11alpha1 were activated, collagen 4alpha1 and fibromodulin inactivated and the genes for Col 1alpha1, biglycan und chondroadherin constantly expressed.

CONCLUSION

The genetic profile for the investigated markers in human chondrocytes generated from hMSCs resembles the profile in differentiated chondrocytes. Collagen 2alpha1, 9alpha2, 9alpha3, 10alpha1 could represent markers for the differentiation of chondrocytes, Col 1alpha1, 3alpha1 und 4alpha1, biglycan, fibromodulin and lumican markers for the dedifferentiation into a more fibroblastoid cell type.

Advances in skeletal muscle tissue engineering

Skeletal muscle tissue engineering is a promising interdisciplinary specialty which aims at the reconstruction of skeletal muscle loss caused by traumatic injury congenital defects or tumor ablations. Due to the difficulty in procuring donor tissue, the possibilities for alternative treatment like autologous grafting (e.g. muscle flaps) are limited. This process also presents consistent problems with donor-site morbidity. Skeletal muscle tissue engineering tries to overcome this problem by generating new, functional muscle tissue from autologous precursor cells (stem cells). Multiple stem cells from different sources can be utilized for restoration of differentiated skeletal muscle tissue using tissue engineering principles. After 15 years of intensive research in this emerging field, for the first time, solutions using different strategies (e.g. embryonic stem cells, arterio-venous (AV) loop models, etc.) are being presented to resolve problems like vascularisation of tissue engineered constructs. This article reviews recent findings in skeletal muscle tissue engineering and outlines its relevance to clinical applications in reconstructive surgery.

Vakuumassistierte Therapie zur Wundbehandlung im Kopf-Hals-Bereich

Chronic wounds are characterized by slow or nonexistent wound healing. Usually their treatment is expensive. Therefore new concepts in management are of interest in order to reduce treatment time and costs. One option is vacuum sealing. The concept of topical negative pressure is not new, and many chronic nonhealing wounds could be closed successfully with the help of vacuum sealing. Until now, there has been no documented case of vacuum sealing in head and neck reconstructive surgery. Our case shows the effectiveness of a vacuum-assisted device in successful closure of a chronic nonhealing wound in this region.

The impact of emotions on the perception of dyspnea in pediatric asthma

Inadequate symptom perception is increasingly recognized as a contributing factor in asthma morbidity. Recent research has shown that psychological factors can influence the perception of asthmatic symptoms such as dyspnea, but little is known, about the impact of emotions on the perception of dyspnea in pediatric asthma. Therefore, we examined the impact of viewing affective film clips of positive, neutral, and negative valence on perceived dyspnea during resistive load breathing in children with stable mild asthma. Perceived dyspnea decreased during the positive film compared to baseline and neutral film whereas the level of respiratory loading and respiratory resistance (R5) remained unchanged across conditions. The results underline the potential impact of psychological factors such as emotions on the perception of dyspnea in children with asthma.

Tgf-beta antisense therapy increases angiogenic potential in human keratinocytes in vitro

BACKGROUND

Transforming growth factor-beta (TGF-beta) has been identified as an important component of wound healing. Recent developments in molecular therapy offer exciting prospects for the modulation of wound healing, specifically those targeting TGF-beta. The purpose of this study was to analyze the effect of TGF-beta targeting on the expression of angiogenic vascular endothelial growth factor (VEGF), a key regulator of angiogenesis, and in vitro angiogenic activity.

METHODS

Expression of angiogenic VEGF in tissue samples from chronic dermal wounds was investigated by immunohistochemistry. The effect of TGF-beta targeting using antisense oligonucleotides on the expression of VEGF was analyzed by ELISA and RT-PCR in cultured human keratinocytes. Human endothelial cells (EC) were grown in conditioned medium produced from the treated keratinocytes. EC migration was measured using a modified Boyden chamber, EC tube formation was analyzed under the light microscope.

RESULTS

Immunohistochemical investigation demonstrated a decreased expression of VEGF protein in tissue samples from chronic dermal wounds compared to normal human skin. Antisense TGF-beta oligonucleotide treatment upregulated VEGF secretion in vitro. Addition of conditioned medium from TGF-beta antisense-treated keratinocytes resulted in an increase of endothelial cell migration and tube formation.

CONCLUSIONS

Our results demonstrate that TGF-beta antisense oligonucleotide technology may be a potential therapeutic option for stimulation of angiogenesis in chronic wounds.

Perspectives of Gene Therapy in Stem Cell Tissue Engineering

Tissue engineering is an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain or improve tissue function. It is hoped that forming tissue de novo will overcome many problems in plastic surgery associated with such areas as wound healing and the immunogenicity of transplanted tissue that lead to dysfunctional repair. Gene therapy is the science of the transfer of genetic material into individuals for therapeutic purposes by altering cellular function or structure at the molecular level. Recently, tissue engineering has been used in conjunction with gene therapy as a hybrid approach. This combination of stem-cell-based tissue engineering with gene therapy has the potential to provide regenerative tissue cells within an environment of optimal regulatory protein expression and would have many benefits in various areas such as the transplantation of skin, cartilage or bone. The aim of this review is to outline tissue engineering and possible applications of gene therapy in the field of biomedical engineering as well as basic principles of gene therapy, vectors and gene delivery.

Hyperplastische Narben und Keloide

Aberrant wound healing results in unsightly scarring, hypertrophic scarring, and keloid formation, causing functional and cosmetic deformities, discomfort, psychological stress, and patient dissatisfaction. Scar management, both surgical and non-surgical, continue to be important issues for the facial plastic surgeon. Many techniques for the management of hypertrophic scars and keloids have been proven through extensive use, but few are supported by prospective studies with adequate control groups. Several new therapies showed good results in small-scale trials, but these have not been repeated in larger trials with long-term follow-up. This article presents an overview of the available therapies and provides recommendations for the treatment of abnormal scarring. The recommendations focus on the management of hypertrophic scars and keloids. Strategies for the management of keloids and hypertrophic scars are of continuing interest and studies are necessary to understand the basic mechanisms causing aberrant wound healing. In addition, an overview of new developments in molecular wound management and gene therapy, as they relate to facial plastic surgery, is provided.

Hyperplastische Narben und Keloide

Aberrant wound healing results in unsightly scarring, hypertrophic scarring, and keloid formation, causing functional and cosmetic deformities, discomfort, psychological stress, and patient dissatisfaction. Scar prevention and management continue to be important issues for the facial plastic surgeon. This article presents an overview on the pathogenesis of a scar and of the different types of scars. Differences between keloids, hypertrophic scars and normal scars include distinct scar appearance, histologic morphology and cellular function in response to growth factors. Recent advances in our understanding of the wound healing process reveal possible causes for hypertrophic scars and keloids. This information might assist in the development of efficacious prevention and treatment for hypertrophic scar and keloid formation. This article also describes the strategies available for scar prevention. Recommendations focus on the management of hypertrophic scars and keloids.

[Examination of granuloma of revised cemented or cementless total hip arthroplasties using inductively coupled plasma atomic emission spectrometry (ICP-OES)]

INTRODUCTION

Aseptic loosening is the most common problem in total hip arthroplasty (THA). One main aspect is inflammatory reaction against wear particles of the prosthesis materials. Analysing failure mechanisms in THA analysis of the particles and their element distribution of revised granulomatous tissue is essential to improve materials used in THA.

MATERIALS AND METHODS

23 granulomas of revised THA due to aseptic loosening, 13 of which with metal on metal bearing (M/M), were analysed using inductively coupled plasma atomic emission spectrometry (ICP-OES).

RESULTS

Elements Cr, Mn, Ni, Al, Cu, Zn, Cd, Ti, V, Zr, Nb and Fe could be detected. The maximum value of Cr was 23.88 ppb (parts per billion), Al 191.02 ppb, Ni 64.95 ppb and Zr 9.96 ppb. The highest value of Al could be found in cementless implants. The maximum value of the elements Cr and Ni could be detected in M/M. In cemented implants the highest value of Zr was found.

DISCUSSION

The origin of Zr was the used bone cement in cemented THA. The elements Cr and Ni were significantly higher in M/M bearings. The highest value of Al was detected in granulomas of revised corund rough blasted cementless implants. The histopathologic findings of the revised M/M bearings have been published recently. Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-OES) could not show any differences of the alloying constituents in cases with or without allergic reactions. ICP-OES analysis seems to be not useful examination of histologic sections using SEM with cryotransfer unit.

Hereditary hemorrhagic telangiectasia: an update on clinical manifestations and diagnostic measures

Hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber disease, is an autosomal dominant disorder of the fibrovascular tissue. It is characterized by the classic triad of (muco-)cutaneous telangiectases, arteriovenous malformations with recurrent epistaxis and hemorrhages, and inheritance. A wide variety of clinical manifestations in HHT have been described. In more than 90% of the patients, nosebleeds are the first predominant symptom, therefore ENT physicians often play a key role as far as diagnosis and management of the disease are concerned. In spite of recent diagnostic and therapeutic progress, a cure for this often burdening and handicapping disease is still not available. Apart from affecting the nose, arteriovenous malformations (AVMs) may also affect the skin, lungs, brain, liver and gastrointestinal tract. The two known genes that are implicated in HHT are endoglin (ENG) located on chromosome 9q33-q34 and activin-receptor-like kinase (ALK1) located on chromosome 12q13. Mutations of ENG are observed in HHT type 1 with an incidence up to 40% for pulmonary AVMs, whereas mutations of ALK1 are observed in HHT type 2 with an incidence of only 14% for pulmonary AVMs, which clinically distinguishes these two types of mutation. The emphasis of this paper is mainly on the clinical manifestation, molecular genetics and diagnosis of HHT, taking account of current literature on HHT in order to better understand the complexity of the disease. Recent therapeutic options in the treatment of HHT have been omitted from this paper as they are subject of a following paper. HHT is more common than previously thought and shows a broad range of different clinical organ manifestations that can be sources of substantial morbidity and mortality, making HHT a continuing challenge for many sub-specialties where interdisciplinary diagnostic screening is mandatory in the management of the disease.

Ossifying fibromyxoid tumor of the nasal septum

The fibromyxoid tumor is quite a rare soft tissue tumor and typically presents as an ossifying fibromyxoid tumor (OFMT) in the subcutis of the extremities of adults. Most authors favour schwannian or chondroid origin of this lesion with somehow uncertain biologic dignity. Local recurrence is seen in 27% of patients after primary excision. We present a case of a fibromyxoid tumor of the nasal septum in a 49-year-old female who complained of nasal airway obstruction and enlargement of the right contour of the nose. Endonasal, endoscopic tumor excision was performed. The tumor contained spindle-shaped and polygonal cells, mucoid pseudocysts and a fibromyxoid stroma with local calcifications. The clinical behaviour of OFMT in general is benign but some reports have documented atypical tumors with histologic signs of malignancy. Complete local resection is the treatment of choice. Because of the high rate of local recurrence, clinical follow-up examinations are necessary.

Stability of the replicator equation for a single species with a multi-dimensional continuous trait space

The replicator equation model for the evolution of individual behaviors in a single species with a multi-dimensional continuous trait space is developed as a dynamics on the set of probability measures. Stability of monomorphisms in this model using the weak topology is compared to more traditional methods of adaptive dynamics. For quadratic fitness functions and initial normal trait distributions, it is shown that the multi-dimensional continuously stable strategy (CSS) of adaptive dynamics is often relevant for predicting stability of the measure-theoretic model but may be too strong in general. For general fitness functions and trait distributions, the CSS is related to dominance solvability which can be used to characterize local stability for a large class of trait distributions that have no gaps in their supports whereas the stronger neighborhood invader strategy (NIS) concept is needed if the supports are arbitrary.

In Vitro Analysis of Differential Expression of Collagens, Integrins, and Growth Factors in Cultured Human Chondrocytes

OBJECTIVES

Tissue engineering represents a promising method for the construction of autologous chondrogenic grafts for reconstructive surgery. In cultured chondrocytes, the dedifferentiation and proliferation of the cells are critical factors that influence the generation of transplants. The aim of our study was to find and characterize markers for cell proliferation and dedifferentiation in cultured chondrocytes.

STUDY DESIGN AND SETTING

Human chondrocytes were isolated from septal cartilage and held in primary cell culture. Cells were harvested after 1, 6, and 21 days. The differentiation of the cells was investigated with bright-field microscopy, the expression patterns of various proteins using immunohistochemistry, and the expression of distinct genes with the microarray technique.

RESULTS

The chondrocytes showed a strong proliferation. After 6 and 21 days, collagen 9 and 10 were downregulated; collagen 11 was activated. Collagen 1 and 2 were downregulated after 6 days but were reactivated after 21 days. Tumor growth factor beta (TGF-beta)1 was strongly expressed on days 1, 6, and 21, TGF-beta2 was never expressed, and TGF-beta3 and -beta4 were upregulated from day 1 to day 21. The TGF-beta receptor III was expressed on days 1, 6, and 21. Integrin beta1, beta5, and alpha5 were upregulated from day 1 to day 21; integrin beta3 was downregulated.

CONCLUSION AND SIGNIFICANCE

Collagens 3, 4, 8, 9, and 11 might be new markers for the dedifferentiation of chondrocytes. Collagen 2 might be a marker for the synthetic activity of the cells rather than the dedifferentiation. TGF-beta3 and -beta4 might influence the dedifferentiation, which is fortified by the expression of TGF-beta receptor III. Integrin beta1, beta5, and alpha5 might be involved in signal transmission for the dedifferentiation.

Differential expression of a gene signature for scavenger/lectin receptors by endothelial cells and macrophages in human lymph node sinuses, the primary sites of regional metastasis

Sentinel lymph node biopsy for several cancers has shown that metastatic tumour cells are preferentially arrested in the lymph node sinuses. To study the molecular components of this sinusoidal trap, gene profiling of lymph node (sinuses) versus tonsil (no sinuses) was performed. Among other groups of molecules, an intriguing gene signature of scavenger and lectin-like receptors was identified. Nine of the 13 genes were preferentially expressed in sinusoidal cells by immunohistochemistry. Using stabilin-2 and monoclonal antibody 3A5 as exclusive endothelial cell (EC) and macrophage (Mvarphi) markers, respectively, lymph node sinusoidal ECs (stabilin-2+, LYVE-1+, DC-SIGNR+, MARCO+, stabilin-1+, MMR+) and sinusoidal Mvarphi (MMR+, DC-SIGN+, sialoadhesin+, CD163+, stabilin-1+ ) showed distinct, but overlapping expression patterns of the signature molecules by double labelling immunofluorescence. The number of stabilin-1+ sinusoidal Mvarphi, however, varied considerably between samples, indicating turnover/differentiation dynamics in this sinusoidal cell population. In the hepatic sinuses, LYVE-1 and CD36 were strongly up-regulated on both sinusoidal ECs and Mvarphi, while DC-SIGNR and DC-SIGN were strongly down-regulated; in contrast to lymph node sinusoidal ECs, MARCO was confined to Mvarphi (Kupffer cells) in the liver sinuses. As Mvarphi are not present in the wall and lumen of splenic sinuses, splenic sinuses expressed a considerably reduced repertoire of scavenger/lectin receptors lacking sialoadhesin, CD36, CD163, and MARCO; in addition, DC-SIGNR was absent from splenic sinusoidal ECs, while DC-SIGN and thrombomodulin were strongly expressed. Interestingly, most of the signature molecules are known to mediate tumour cell adhesion in addition to their functions as scavenger or pattern recognition receptors. This study establishes a gene and tissue database platform to test the hypothesis that additive expression of the lymph node sinus signature genes in sinusoidal ECs and Mvarphi may contribute to selective tumour cell metastasis in lymph nodes and liver including organ-specific mechanisms, such as intraluminal retention or transmigration, while sparing the spleen.

Management of radiation-induced tracheocutaneous tissue defects by transplantation of an ear cartilage graft and deltopectoral flap

Patients suffering from head and neck cancer often require temporary tracheostomy during therapy. The tracheostomy can usually be closed when postoperative swelling decreases and swallowing ability recovers. However, some patients, especially after adjuvant radiotherapy, may develop severe chronic wounds resulting in persistent tracheocutaneous fistula. Local wound care and plastic reconstruction strategies are required in such cases. We present two patients with head and neck cancer treated with primary surgical regimen including temporary tracheostomy and adjuvant radiotherapy. Both patients developed a persistent, poorly healing wound with persistent tracheocutaneous tissue defect. After local debridement and wound care, the peristomal necrotic tissue was excised down to the level of the trachea. The defect of the anterior tracheal wall was closed with a autogenous ear cartilage graft. The graft was harvested from the cavum conchae and sutured to the tracheal defect. The soft tissue defect was covered by transposition of a well-vascularized, fasciocutaneous deltopectoral flap. In both cases, the flaps healed satisfactorily. The donor defect was closed primarily. Complications were not observed in these two cases. A flexible tracheo-bronchoscopy showed no stenosis of the trachea at the site of cartilage graft transplantation. In conclusion, treatment of persistent radiated tracheocutaneous defects by cartilage graft and deltopectoral flap turned out to be a safe and reliable procedure which can be performed as a one-stage method with low morbidity at the donor site.