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Biomedical subjects

F Riedel

Publications and source records attributed to F Riedel.

At least 19 recordsLinked to original sources
PubMed2007

[Vacuum-assisted closure of nonhealing wounds in head and neck reconstructive surgery].

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.

Aged↗
PubMed2006

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.

Biomarkers↗
PubMed2006

[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.

Aged↗
PubMed2006

[Hyperplastic scars and keloids. Part I: basics and prevention].

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.

Adult↗
PubMed2006

[Hyperplastic scars and keloids: part II: Surgical and non-surgical treatment modalities].

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.

Adrenal Cortex Hormones↗
PubMed2005

[Plastic surgery of skin defects in the face. Principles and perspectives].

The difficulties in facial reconstruction derive from the unique character of the face and the availability of local matching tissues. Facial reconstructive surgery must aim at a functionally and aesthetically rehabilitated patient. The performance of facial plastic surgery requires an understanding and the application of many important principles. The aim of this paper is to review the critical factors to be considered in the management of surgical wounds by second-intention healing, primary closure, skin grafting, and repair with local or distant free flaps. The key concepts useful in flap choice and implementation are discussed. In addition, an overview of new developments in tissue engineering and gene therapy as they relate to facial plastic surgery is provided.

Face↗
PubMed2004

[Dexpanthenol nasal spray in comparison to dexpanthenol nasal ointment. A prospective, randomised, open, cross-over study to compare nasal mucociliary clearance].

BACKGROUND: Recent technical developments in metered pump systems allow the production and use of preservative-free nasal products. The aim of the current study is to compare the tolerability of a preservative-free dexpanthenol (5%) nasal spray with that of the established dexpanthenol (5%) nasal ointment, also without preservatives. The main outcome measure was in vivo mucociliary clearance. METHOD: Mucociliary clearance was assessed by saccharin migration time in 20 volunteers. Wash-out phases were 7 days and the spray or ointment was always applied 20 min before the saccharin test. The study was designed to test for non-inferiority. RESULTS: Saccharin migration time was slightly longer after ointment administration, however, these were not significantly different to nasal spray. The saccharin migration time showed a significant correlation with the age of the volunteers. The upper confidence limit of dexpanthenol nasal spray was markedly less than that of the ointment. Therefore, dexpanthenol nasal spray is at least equal to if not better than dexpanthenol nasal ointment. CONCLUSIONS: Due to its ease of administration, preservative-free dexpanthenol nasal spray offers a valuable therapeutic alternative.

Adult↗
PubMed2004

[Alcohol related diseases of the head and neck].

Chronic consumption of alcohol is an accepted social custom worldwide. In the upper aerodigestive tract, local morphologic, metabolic and functional alterations can be present due such consumption. Gastroesophageal reflux or alterations in sleep structure are typical examples of functional disorders. While alcohol was initially described as a risk enhancer only in smokers, a number of epidemiological studies have now shown that chronic alcohol consumption increases the risk of head and neck cancer independently of exposure to tobacco smoke. In addition, alcohol leads to an accumulation of pathologic microbes within the mucosa, leading to chronic infection. Susceptibility to carcinogens and cell proliferation in the mucosa are increased, resulting in genetic changes with the development of dysplasia, leucoplakia and carcinoma. Chronic alcohol consumption is correlated with an increased risk of cancer and increased mortality in a dose-dependent relationship. A number of biologically plausible mechanisms exist by which alcohol may cause cancer.

Alcoholism↗
PubMed2004

[Cell adhesion proteins in external auditory canal cholesteatoma].

BACKGROUND: External auditory canal cholesteatoma (EACC) is a rare entity in otolaryngology, which is histomorphologically identical with middle ear cholesteatoma. The cause of EACCt is, however, still not clear. The aim of this study was to describe the expression of beta-catenin, MMP-2, and MMP-9 in EACC matrix compared to the normal auditory meatal skin (AMS). METHODS: Thirteen specimens were obtained during surgical procedure. EACC and AMS specimens were immunostained with antibodies for beta-catenin, MMP-2, and MMP-9. RESULTS: Only the basal layers of the EACC specimens were positive for beta-catenin. The suprabasal layers showed diminished or negative immunostaining for beta-catenin. In all layers, AMS was homogeneously positive for beta-catenin. In contrast, the immunostaining for the gelatinases was equally increased in all layers of EACC, whereas AMS was weekly positive. CONCLUSION: The reduced immunoreactivity for beta-catenin may have been present because of the lessened cell-cell adhesion in the suprabasal layers of EACC. The increased expression of the metalloproteinases might point at an increased lack of integrity of EACC matrix. Recent studies revealed a balance between disintegrating and stabilising factors in normal tissue, which is disturbed in inflamed and neoplastic tissue. In EACC matrix, an imbalance of these factors, represented by reduced beta-catenin and increased gelatinase expression, is possible. Increased desquamation, the accumulation of keratin debris, and loss of tissue-stability support our findings.

Adult↗
PubMed2003

[Argon plasma coagulation and topically applied estriol. Long-term results in the treatment of hereditary hemorrhagic telangiectasia of the nasal mucosa].

BACKGROUND AND OBJECTIVE: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant fibrovascular dysplasia with the main symptom of recurrent epistaxis. At present, only limited data are available on long-term results in the treatment of epistaxis. A part from the surgical treatment of the bleeding telangiectasia with argon plasma, an additional postoperative long-term treatment with estriol nose-ointment was performed and the results were analysed. PATIENTS AND METHODS: 69 patients with HHT were treated with APC and estriol nose ointment. 43 patients could be examined over a follow-up period of more than 20 months. The bleeding frequency and intensity as well as the patient's satisfaction with the treatment result were evaluated and the serum estriol level determined. RESULTS: After more than 20 months, the bleeding frequency and intensity were reduced in 95% of the patients compared to their preoperative findings. Under the influence of estriol, former berry-like telangiectasias became flatter and more even. Neither systemic side effects under topically applied estriol nor a relevant increase of serum estriol levels were observed. CONCLUSION: The combined treatment regimen with APC and topically applied estriol provides a new treatment concept of epistaxis in HHT.

Administration, Topical↗
PubMed2003

[Delayed neuropathy of the sciatic nerve after total hip replacement with an acetabular reinforcement ring].

AIM: Lesions of the sciatic or femoral nerve after THR are typical complications. Delayed neuropathies of the sciatic or femoral nerve are rare conditions. CASE REPORT: We report the case of a delayed neuropathy of the sciatic nerve after THR with reconstruction of the acetabulum with an acetabular reinforcement ring. After electrophysiologic evaluation we performed a revision of the sciatic nerve. Intraoperatively we found an impingement of the sciatic nerve between the dorsal aspect of the acetabular reinforcement ring and scar tissue. After revision of the nerve, resection of the scar tissue and interposition of a fat pad the patient was out of any complaints but reported some sensory deficits of the first toe. CONCLUSION: Using acetabular reinforcement rings for reconstruction of acetabular defects care has to be taken of the correct position. In anatomically cramped positions a protruding of the dorsal edge of the ring may cause a lesion of the sciatic nerve.

Acetabulum↗
PubMed2001

[Treatment of therapy refractory chronic otitis externa by local injection of triamcinolone acetate crystalline suspension. Initial experiences].

BACKGROUND AND OBJECTIVE: External otitis is characterized by otalgia, otorrhea, itching, and hearing loss. Treatment usually consists of local application of corticosteroids and antibiotics. Chronic external otitis is accompanied by thickening of the skin in the external auditory channel. This reduces the effect of the applied substances. Local injection of suitable drugs may support the conservative treatment. The aim of the study was to evaluate the efficacy of local injection of triamcinolone acetonide in the external auditory channel. PATIENTS/METHODS: Thirteen patients with external otitis resistant to conservative treatment received an injection of triamcinolone acetonide in the external auditory channel. The improvement achieved was assessed by clinical examination and questionnaires. RESULTS: The symptoms improved substantially in all patients; most of the patients were cured completely. CONCLUSIONS: Our results demonstrate that local injection of triamcinolone acetonide is effective in the management of chronic external otitis.

Adult↗
PubMed2001

[Serum concentrations of soluble adhesion molecules sICAM-1 and sVCAM-1 in patients with malignant ENT tumors].

BACKGROUND: Adhesion molecules are implicated in various stages of tumor progression and metastasis. Soluble forms of intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) were recently described. The aim of this study was to determine a differences in concentration of these molecules in patients with head and neck squamous cell carcinoma (HNSCC) compared to healthy controls. PATIENTS AND METHODS: We investigated the circulating levels of sICAM-1 and sVCAM-1 in sera from patients with various head and neck squamous cell carcinomas (n = 52) as well as from normal, healthy controls (n = 35). Serum concentrations were determined as serum immunoreactivity by using a quantitative sandwich enzyme immunoassay technique. For statistical analysis, the Student's t-test was performed. RESULTS: The majority of the patients with HNSCC were found to have high concentrations of sICAM-1 and sVCAM-1. The mean level of sICAM-1 in patients was 313 ng/ml and in the control group 237 ng/ml (p = 0.0005). The mean level of sVCAM-1 in patients was 624 ng/ml and in the control group 435 ng/ml (p = 0.009). The concentrations of sICAM-1 and sVCAM-1 were significantly higher in HNSCC patients. CONCLUSIONS: These results show the difference in expression of these adhesion molecules in patients with HNSCC compared to healthy controls. Endothelial adhesion molecule determination may find clinical applications in the follow-up of cancer therapy. For this reason, studies incorporating the longitudinal follow-up of patients are required.

Biomarkers, Tumor↗