Biomechanical Load Quantification Using a Lower Extremity Inertial Sensor Setup During Football Specific Activities.

Training load monitoring systems in football do not focus on lower extremities and therefore potentially neglect important information to optimise performance or reduce injury risk. The current study aims to present joint and segment angular accelerations as novel indicators to quantify lower extremity biomechanical load measured by a new inertial sensor setup. Relationships were explored with commonly used whole-body training load indicators using principal component analysis (PCA). Sixteen male amateur football players performed a linear sprint and an agility T-test. An inertial sensor setup, and local position measurement system were used to collect training load data. Hip Load, Knee Load, Thigh Load and Shank Load were introduced to quantify lower extremity biomechanical load. Three principal components were identified for both tests, explaining 91% and 86% of the variance. The indicators for the lower extremities contributed to the second principal component for both tests and provide distinct information compared to whole-body load indicators. The results show the potential to use an inertial sensor setup combined with common monitoring systems to evaluate training load, which may help optimise future performance and reduce injury risk. These relationships should be further examined during other football specific activities such as shooting or jumping.

Does the additional use of heparin-coated extracorporeal circuits (ECC) optimize the effect of modified ultrafiltration (MUF) in pediatric perfusion?

BACKGROUND: Modified ultrafiltration (MUF) has been shown to exert beneficial effects on the coagulation system and the capillary leak after pediatric cardiac surgery using extracorporeal circulation (ECC). The aim of this study was to investigate whether the additional use of heparin-coated circuits is a useful option for improving biocompatibility. METHODS: We randomized 28 children, using heparin-coated ECC circuits in group A (n = 14) and an uncoated equivalent set in group B (n = 14). After congenital heart surgery, MUF was performed post ECC in a standardized fashion. Blood samples were analyzed preoperatively, 10 min, 30 min, 1 h, and 48 h after ECC by flow cytometric analysis (FACSort) using surface antigens CD62/CD41b (platelets) and CD45/CD14 (monocytes). RESULTS: No significant difference was found with respect to mean age (20.6 months vs. 21.6 months), mean body weight (9.2 kg vs. 8.4 kg), mean ultrafiltration rate (9.1 ml/kg vs. 11.4 ml/kg), chest tube drainage, blood products, ICU stay, and 30-d survival. The percentage of CD62/CD41-positive platelets in group A (vs. B) increased up to 118 % at 60 min vs. 130 % ( P < 0.05) and declined to 98 % at 48 h postop. vs. 99 % (n. s.). The percentage of CD45/CD14-positive monocytes in group A (vs. B) increased up to 158 % at 60 min vs. 155 % (n. s.) and declined to 122 % (A) at 48 h postop. vs. 61 % (B) ( P > 0.05). CONCLUSIONS: Heparin coating of ECC in addition to MUF leads to a lower platelet activation. Monocyte surface markers CD45 and CD14 indicated a marked activation during ECC in both groups but additional heparin coating showed a better postoperative regeneration of monocyte markers in the late course indicating a beneficial additive effect.

[Clinical and epidemiological data of patients with malignomas of the head and neck]. / Klinische und epidemiologische Daten zu Malignomen des Kopf-Hals-Bereichs.

BACKGROUND: The present study describes clinical and epidemiological data of patients with malignomas of the head and neck documented in the Munich Cancer Register. PATIENTS AND METHODS: Data of head and neck cancer patients treated at four departments of head and neck surgery and one of oral-maxillo-facial surgery in the area of Munich from 1978 up to now are reported. RESULTS: Incidence and mortality as a function of age, sex, and tumor localization are described in comparison to clinical and epidemiological data as specified in tumor registers of the Saarland and the USA. Moreover, TNM stages, survival, recurrence, and metastasis rates are presented. CONCLUSION: Based on the documentation of the Munich Cancer Register our study is the first to present a detailed description of clinical and epidemiological data of patients suffering from head and neck malignomas.

[Realistic imaging of cell systems using confocal laser scanning microscopy exemplified by 3-dimensional chondrocyte culture]. / Die realitätsgetreue Darstellung von Zellsystemen mit Hilfe der Konfokalen-Laser-Scanning-Mikroskopie am Beispiel dreidimensional kultivierter Chondrozyten.

BACKGROUND: We have developed a three-dimensional model for tissue engineering of cartilage. Chondrocytes were isolated and first multiplied in conventional monolayer cultures. Then the cells are seeded with or without agarose on special absorbable scaffolds that provided stability and enabled three-dimensional cell distribution of the tissue-engineered cartilage. The aim of the study was to investigate the possibility of avoiding agarose in tissue engineering because of the potential risk of causing an inflammatory process in later human implantation. METHOD: For the first time we investigated cell distribution combined with vitality directly in the cell carrier under the conditions described by using confocal laser-scanning microscopy. Working with unfixed cells, this method enables the reconstruction of three-dimensional cell cultures with suitable cell markers that closely simulates the physiologic situation, thereby exceeding each other method. RESULTS: It was evident that agarose had no positive effect on cell distribution and vitality. CONCLUSION: Further experiments concerning the effect of agarose on synthesis of cartilage-specific matrix are in progress.

[Cellular viability of cryopreserved cartilage grafts]. / Viabilidad celular de injertos de cartílago crioconservados.

Transplantation of preserved cartilage has an important role in reconstructive surgery. Opinions vary with regard to the performance of cryopreserved cartilage. We studied the functional state of chondrocytes after cryopreservation. Cellular survival was studied using the trypan blue dye exclusion test, a functional assay for cell adhesion, and transmission electron microscopy. Most chondrocytes were irreversibly damaged by cryopreservation and the cartilage could not originate new cartilage. Therefore, cryopreserved cartilage tends to generate fibrosis and resorption and is not practical for reconstructing skeletal parts exposed to mechanical stress.

Influence of chemical allograft preservation procedures on the human immunodeficiency virus.

Since chemically preserved allogenic transplants have an established place in reconstructive procedures, the possibility of transferring the human immunodeficiency virus (HIV) with these transplants has been intensively discussed. In this study the authors obtained brain and spleen samples from six HIV-infected cadavers and preserved them with Merthiolate, Cialit, and formaldehyde. After preservation, the tissues were examined for proviral HIV-1 DNA (gag, pol, env) using the polymerase chain reaction. Proviral sequences were clearly demonstrated after the preservation procedure. The results of this study indicate that HIV remains in tissues that have been treated with Merthiolate, formaldehyde, or Cialit. Further investigations are necessary to determine if the virus is in an inactivated or activated form. It can be concluded that, because of the possible transmission of HIV by chemically preserved homografts, serologic screening of donors should be mandatory.

Expression of ICAM-1 on intact cartilage and isolated chondrocytes.

A major factor in cellular cytotoxicity is the interaction between LFA-1 on leukocytes and ICAM-1 on targets. Because several inflammatory cartilage diseases are characterized by the presence of leukocyte infiltrates, the expression of ICAM-1 on human cartilage, cultured chondrocytes, and transplanted cartilage was investigated using monoclonal antibodies. Frozen tissue sections, chondrocytes in suspension, as well as total cellular mRNA were prepared from human cartilage samples. ICAM-1 expression was studied with two different monoclonal antibodies directed against ICAM-1 by immunohistochemical APAAP-staining and additional flow cytometric analyses. The expression of ICAM-1-mRNA in cartilage tissue was analyzed using the northern blot hybridization technique. Furthermore, chondrocytes were treated in culture with interleukin-1 (IL-1) and gamma-interferon (gamma-IFN). ICAM-1 expression after culture was quantified using flow cytometric analysis. We could detect ICAM-1 mRNA in cartilage tissue, however, the immunostaining of tissue sections using monoclonal antibodies did not give clear positive reactions. Isolated chondrocytes showed strongly positive staining patterns in comparison with adequate negative controls as assessed by flow cytometry. A dose-dependent increase of the expression of ICAM-1 on chondrocytes was observed when stimulated with IL-1 and gamma-IFN. Finally, two of the three studied transplanted autologous cartilage samples with advanced resorption showed the presence of ICAM-1 molecules as assessed by immunohistochemistry. This expression of ICAM-1 suggests that the molecule plays a role in severe cartilage inflammatory processes, where tissue damage leads to the exposure of chondrocyte surfaces.

Effect of growth factors on matrix synthesis by human nasal chondrocytes cultured in monolayer and in agar.

Reconstructive surgery of multiple areas of the body may require replacement bone or cartilage transplants to repair defects or lesions of skeletal tissue. Advances in cell and tissue culture techniques now permit synthesis of autologous human cartilage in vitro. Several growth factors regulate the metabolism and activation of cartilage cells. To enhance culture conditions and effectiveness for in vitro cartilage engineering, the aim of our investigations was to characterize the influence of transforming growth factor (TGF)-beta and basic fibroblast growth factor (bFGF) on human nasal septal chondrocytes. The isolated cells were cultured as monolayers on plastic and in soft agar. The biological effects of the growth factors were assessed by determining synthesis of total protein and proteoglycan. TGF-beta caused a dose-dependent stimulation of total protein as well as glycosaminoglycan synthesis by all chondrocytes cultured. This stimulatory effect of TGF-beta was greater for chondrocytes cultured in soft agar than for chondrocytes cultured on plastic. No stimulatory effects of matrix synthesis was observed for bFGF in either culture condition. Our results show that TGF-beta can be employed to enhance in vitro production of cartilage grafts for reconstructive surgery.

[Allogeneic transplantation and HIV infection: studies of HIV-infected tissue]. / Allogene Transplantation und HIV-Infektion: Untersuchungen an HIV-infiziertem Gewebe.

BACKGROUND: Because of the limited availability of autologous tissue, stored allograft is commonly used. Before grafting, bank tissue is subjected to chemical preservation procedures. This procedure is important to diminish antigenicity and to inactivate possible inherent viruses. The aim of this study was to determine the influence of different chemical preservation procedures like Cialit, Merthiolate, and formaldehyde on the presence of HIV DNA. METHODS: HIV-infected tissues were obtained from eight HIV-positive patients and examined using the polymerase chain reaction (PCR). RESULTS: After chemical treatment, we could observe the presence of HIV DNA in all examined tissues. CONCLUSIONS: The findings indicate the importance of the mandatory serological screening and selection in donor patients.

Laryngeal reconstruction using allogeneic cartilages.

Preserved allogeneic cartilage has been used to reconstruct laryngeal defects. The most important problem with this approach has been graft resorption, which seems to be caused by devitalization of the grafts as a consequence of preservation. In this study, the authors compared the in vivo behavior of vital and nonvital preserved cartilage used to reconstruct the larynx of New Zealand white rabbits. The vital cartilage grafts were stored using organ culture procedures, and the nonvital grafts were stored in formaldehyde. While the formaldehyde-preserved cartilage showed inflammatory changes, the transplanted vital cartilage was well accepted and showed no evidence of immune cell infiltrations. The authors concluded that viable cartilage grafts are preferable to grafts of chemically preserved cartilage.

[Self-expandable prosthesis for the management of cervical and thoracic tracheomalacia]. / Prótesis autoexpandibles en el tratamiento de la traqueomalacia cervical y torácica.

Four patients afflicted of cervical and thoracic tracheomalacia have been treated with self-expandable and elastic metal prosthesis. The implantation of this prosthesis resulted in immediate improvement of the respiratory function. Long-term follow-up of these patients (24 months) showed a very good evolution. In this paper we describe the prosthesis features, the implantation technique as well as the radiological and endoscopic results.

[Analysis of the possibility of transmitting the human immunodeficiency virus when using cartilage grafts]. / Análisis de las posibilidades de transmisión del virus de la inmunodeficiencia humana usando injertos de cartílago.

Allogenic cartilage represents an important source of tissue for reconstructive surgery in the head and neck. The use of allografts is now being discussed because of the possible transmission of the human immunodeficiency virus (HIV). The purpose of this study was to investigate the susceptibility and permissivity of cartilage tissue to HIV-1, in order to analyze the possibility of a HIV-transmission through cartilage allografting.

[Clinical and electron microscopy study of sudden deafness treatment with the 10% HES 200/0.5 and pentoxifylline combination]. / Klinische und elektronenmikroskopische Untersuchung zur Hörsturztherapie mit der Kombination 10% HES 200/0.5 und Pentoxifyllin.

The incidence of sudden hearing loss has increased. The pathogenetic mechanisms are still unknown, but viral infections and vascular phenomena with acute impairment of microvascular perfusion are thought to play a major role. Infusion of hydroxyethyl starch (HES) is used as a regimen to treat sudden hearing loss. In our clinic, anaphylactic reactions due to HES have not been observed so far. However, the use of HES is still discussed controversially due to long-term storage of HES molecules in tissue and due to high incidence of long-lasting pruritus. In a retrospective analysis of 118 patients treated with HES for sudden hearing loss, we observed pruritus starting in 64% of patients one to three weeks after therapy. This symptom with a duration between two weeks and four months was refractory to medical interventions. During therapy with HES improvement of hearing was observed in 75% of patients, in 62% improvement of hearing persisted still at the end of the observation period (7 months post infusionem). Light and electron microscopic assessment of human skin biopsies of one patient after treatment with HES showed storage of HES especially within dermal macrophages. Pathogenetically a pathway independent of histamin seems responsible for the induction of pruritus. Accordingly, classic antihistaminic drugs had no therapeutic effect in our patients. Dextran is used as an alternative to hydroxyethyl starch. In contrast to HES, the often mentioned higher incidence of severe anaphylactic reactions due to dextran has dramatically decreased with hapten inhibition (after preinjection of monovalent haptendextran Promit).(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of viability of cryopreserved cartilage grafts.

Although transplantation of preserved cartilage has assumed a role of great importance in reconstructive surgery, there are many divergent and contradictory opinions with regard to the outcome of cryopreserved cartilage. This study was formulated to assess the functional state of chondrocytes after cryopreservation. Freeze injury and survival were studied using the trypan blue dye exclusion test, functional assay for cell adhesion and transmission electron microscopy. The methods applied clearly proved that a greater part of the cartilage cells was irreversibly damaged by cryopreservation. Findings demonstrated that cryopreserved cartilage remained non-viable and was not able to originate new cartilage. Thus, such cartilage will be subject to resorption processes and not practical for reconstruction of parts of the skeleton subject to mechanical stress. The feasibility of cryopreservation techniques for providing vital cartilage substitutes needs further evaluation.

Effect of growth factors on cell proliferation by human nasal septal chondrocytes cultured in monolayer.

In the field of reconstructive surgery, autologous cartilage grafting is commonly performed to reconstruct skeletal defects. Because of the limited supply of fresh autologous cartilage many investigators concentrate on in vitro production of cartilage tissue. Several growth factors regulate the metabolism and activation of cartilage cells. In order to enhance the culture conditions for cartilage cells, the aim of our investigations was to characterize the influence of transforming growth factor (TGF)-beta, epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) on the proliferation of differentiated human nasal septal chondrocytes. The isolated cells were cultured in monolayer using DMEM with and without 10% FCS. The cell proliferation was assessed using tritiated thymidine. We measured an increase of the proliferation rates when the different growth factors were added. The most important stimulatory effect was due to bFGF and the less to EGF. If all growth factors were added together a fivefold increase in the proliferative activity of the cells was achieved. The effects were further enhanced by factors present in fetal calf serum. We conclude that the culture conditions for cell expansion for cartilage engineering can be optimized employing growth factors.

[Vital preservation of cartilage transplants with tissue culture methods]. / Vitale Konservierung von Knorpeltransplantaten mittels Gewebekulturmethoden.

Cartilage grafting is one of the most common procedures in plastic surgery. Since storage of both autologous and allogenic cartilage is necessary, different preservation methods have been used with more or less success. The use of chemical preservation procedures like formaldehyde, Merthiolate or Cialit lead to a loss of the vitality of the graft. This work presents a study of the cell vitality and the matrix of cartilage grafts stored in different solutions (formaldehyde, saline, RPMI 1640, Ham F-12 and DMEM 4500) during 150 days. The cell viability was assessed using tissue sections (neutral red supravital staining and trypan blue dye exclusion test) and isolated cells (trypan blue dye exclusion test and cell adhesion in monolayer culture). The state of the cartilage matrix was analysed by means of the azan, alcian and toluidine blue staining). Cartilage immersed in formaldehyde solution lost 100% of the vitality after a storage period of 10 days, the one immersed in saline solution after 30 days. Cartilage stored in tissue culture media retained its vitality (> 85%) during the whole storage time. Histological staining methods showed a decrease of the staining intensity after 10 days storage in formaldehyde and after 30 days storage in saline solution. No differences in vitality and the matrix staining were found among all three culture media. Our results suggest that viable cartilage tissue can be successfully stored for a long time using tissue culture methods.

[Autoantibodies against cartilage components: clinical relevance for reconstructive surgery in the area of the head and neck]. / Autoantikörper gegen Knorpelbestandteile: Klinische Relevanz für die rekonstruktive Chirurgie im Kopf-Hals-Bereich.

The clinical relevance of antibodies against components of cartilage in the reconstructive surgery has not yet been clarified. In our study four groups of patients with successful and unsuccessful autologous cartilage transplantation in rhinosurgery, patients with ear perichondritis and patients with tracheal stenosis after long-term intubation were investigated for the presence of a humoral immune reactivity to cartilage. The control groups consisted of healthy persons and patients with RA. The antibodies against cartilage matrix and chondrocytes were determined using indirect immunofluorescence methods. Patients with unsuccessful cartilage transplantation showed increased antibodies against autologous cartilage (until 1:100) compared to the patients with successful cartilage transplantation. Furthermore, patients suffering from ear perichondritis and tracheal stenosis showed also increased antibodies against cartilage. These data suggest that a humoral immune reactivity against autologous cartilage--independent of an infection--can be one cause for the destruction of cartilaginous tissue.

Humoral immune response against minor collagens type IX and XI in patients with cartilage graft resorption after reconstructive surgery.

OBJECTIVES: The humoral immune response against a broad spectrum of cartilage antigens (cellular and matrix antigens) was studied in a group of patients who showed resorption and/or rejection of transplanted cartilage in nasal surgery. METHODS: Sera were obtained from patients with successful and unsuccessful cartilage grafting in the nose, from age and sex-matched healthy donors and from patients with rheumatoid arthritis. Antibodies to cartilage components were analysed by the following methods: (1) indirect immunofluorescence on cartilage sections, (2) ELISA using cultured human chondrocytes, isolated chondrocyte membranes and purified collagens type I, II, III, VI, IX and XI, and (3) immunoblotting with purified collagens and chondrocyte cell membranes. RESULTS: In the cartilage grafting group showing resorption problems, levels of anti-collagen antibodies were significantly higher against native collagen types IX (p < 0.002) and XI (p < 0.002) compared with the non-resorption group and the normal donors. Both transplantation groups revealed elevated reactivities against isolated chondrocytes in the ELISA. In contrast, no reactivity was detectable against collagens type II, III, and VI and chondrocyte cell membranes by both ELISA and immunoblotting. CONCLUSIONS: These data demonstrate for the first time the existence of a humoral immune response, primarily directed against the so called 'minor cartilage collagens', in patients showing cartilage resorption. Autoreactivities to collagen which are typical of inflammatory rheumatic diseases may also play an important role in the repeated failure of cartilage grafting.

Antibodies to the minor cartilage collagen type IX in otosclerosis.

The presence of antibodies to collagens type I, II, III, VI, IX, and XI was studied in patients with otosclerosis, using enzyme-linked immunosorbent assays. Levels of antibodies to collagens type II and IX were significantly higher in these patients as compared to sex- and age-matched control subjects, whereas no differences were found between the levels of antibodies to collagens type I, III, VI, and XI. These observations for the first time document the presence of autoantibodies against a minor collagen type IX in patients with otosclerosis and support a possible role for collagen autoimmunity in the etiology of otosclerosis.

[Micrometastases in bone marrow of patients with cancers in the head and neck area]. / Mikrometastasen im Knochenmark von Patienten mit Karzinomen des Kopf-Hals-Bereiches.

Individual disseminated epithelial tumour cells were detected in bone marrow aspirates in 41 of 108 patients (37%) with squamous cell cancer of the head and neck region by an immunocytochemical technique based on monoclonal antibodies raised against the cytokeratin No. 19. In the clinical stage I (T1N0M0) tumour cells were detected only in 26.3% of the patients, whereas in stage IV (T4N0M0, T(all)N2-3M0, T(all)N(all)M1) almost twice as many patients (47.7%) presented with tumour cells in the bone marrow. Apparently, grade of differentiation of the tumour (grading) had no influence on the spread of single tumour cells. An influence of the different localisations of the primary tumour on tumour cell spread or the rate of tumour recurrence cannot as yet be discovered. Cytokeratin No. 19 expressing cells were not detectable in the bone marrow of 18 patients with non-malignant disease. Seventy-three patients were included in a follow-up study with a mean observation time of 25 months (range: 4-52 months). The presence of epithelial cells at the time of primary treatment appears to indicate a significantly higher risk of development of local or distant tumour recurrences (p = 0.01). Of 46 patients initially exhibiting no tumour cells in the bone marrow, only 14 had a clinical recurrence. Whereas 17 of 27 patients who presented with tumour cells in the bone marrow developed either a local tumour recurrence or distant metastases in different organs. Patients presenting with bone marrow tumour cells showed a significantly shorter disease-free survival than those without (p = 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)