Johannes Kleinheinz
Research interests
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InterestsReconstructive Surgical Procedures, Reconstructive Surgery, Trauma, Reconstructive, Trauma Surgery
Publications
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2.45Impact points
Multicenter Randomized Clinical Trial: Early Loading of Implants in Maxillary Bone.
Clinical implant dentistry and related research. 01/2012;
Purpose: The aim of this study was to show prognostic equivalence between implant loading in the maxilla after 12 weeks versus 4 weeks. Materials and Methods: One hundred four patients, from four centers in this open-labeled randomized multicenter prospective controlled clinical trial, were assigned... [more] Purpose: The aim of this study was to show prognostic equivalence between implant loading in the maxilla after 12 weeks versus 4 weeks. Materials and Methods: One hundred four patients, from four centers in this open-labeled randomized multicenter prospective controlled clinical trial, were assigned to either 12 weeks or 4 weeks of unloaded healing. Two hundred sixty-nine implants (sand blasted large-grid, acid etched [SLA] surface, ≥4.1 mm diameter; ≥10 mm length) were inserted and evaluated during an individual 5-year follow-up. Primary outcome was implant success after 12 months; prognostic equivalence was characterized by a maximum difference of ±5% in implant failure rates. Results: Implant-wise 1-year failure rates were estimated 3.1% (5/163 implants) in the 4 weeks group versus 3.6% (4/112 implants) in the 12 weeks group (95% confidence interval [CI] for the difference -3.2 -+4.2%); implant-wise evaluation demonstrated statistically significant prognostic equivalence of 4 and 12 weeks loading. Patient-wise 1-year failure rates were estimated 6.7% (n = 4 patients) in the 4 weeks group versus 5.1% (n = 2 patients) in the 12 weeks group (95% CI for the difference -9.6 -+6.5%). All implant failures occurred within the first 3 months of the individual observation period. Prior bone augmentation, underdimensioned drilling, bone quality, implant type, implant length, implant diameter, residual teeth, and fixing of the restoration did not reveal associations with the implant outcome: trial site, posterior jaw region, and splinting were associated with a higher failure rate. Resonance frequency analysis did not serve as a predictor of implant failures at the time of implant insertion. Conclusion: Loading of standard SLA implants in the maxilla 4 weeks versus 12 weeks after insertion resulted in statistically equivalent failure patterns within a 1-year follow-up period; nevertheless, the observed patient-wise failure patterns of the interim analysis requires further understanding of patient-individual aspects of the early loading concept.
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Nasopharyngeal development in patients with cleft lip and palate: a retrospective case-control study.
International journal of otolaryngology. 01/2012; 2012:458507.
Introduction. The aim of this paper was to evaluate cephalometrically the nasopharyngeal development of patients with complete unilateral cleft lip and palate. Influencing factors were evaluated and cleft to noncleft subjects were compared to each other. Material and Methods. The lateral cephalogram... [more] Introduction. The aim of this paper was to evaluate cephalometrically the nasopharyngeal development of patients with complete unilateral cleft lip and palate. Influencing factors were evaluated and cleft to noncleft subjects were compared to each other. Material and Methods. The lateral cephalograms of 66 patients with complete cleft lip and palate were measured and compared retrospectively to the cephalograms of 123 healthy probands. Measurements were derived from a standardized analysis of 56 landmarks. Results. We observed significant differences between cleft and control group: the cleft patients showed amaxillary retroposition and a reduced maxillary length; the inclination of the maxilla was significantly more posterior and cranial; the anterior nasopharyngeal height was reduced; the nasopharyngeal growth followed a vertical tendency with reduced sagittal dimensions concerning hard and soft tissue. The velum length was reduced. In the cleft group, an accumulation of mandibular retrognathia and an anterior position of the hyoid were observed. Skeletal configuration and type of growth were predominantly vertical. Conclusions. Our data provides a fundamental radiological analysis of the nasopharyngeal development in cleft patients. It confirms the lateral cephalogram as a basic diagnostic device in the analysis of nasopharyngeal and skeletal growth in cleft patients.
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Objective Assessment of Hypernasality in Patients with Cleft Lip and Palate with the NasalView System: A Clinical Validation Study.
International journal of otolaryngology. 01/2012; 2012:321319.
Introduction. The objective of this investigation was to evaluate the reliability and validity of the NasalView system as a screening tool for hypernasality within the scope of a routine diagnostic procedure in cleft lip and palate patients. Material and Methods. In a collective of 95 patients with ... [more] Introduction. The objective of this investigation was to evaluate the reliability and validity of the NasalView system as a screening tool for hypernasality within the scope of a routine diagnostic procedure in cleft lip and palate patients. Material and Methods. In a collective of 95 patients with cleft and lip palate ranging from 4 to 25 years of age, hypernasality was exploited perceptually, patients were classified in four degrees, and nasalance was measured objectively with the NasalView system. Speech stimuli existed in one nasal and one nonnasal sentence; nasalance ratio and distance were calculated. Results. The test-retest error was within a range of 2%. Sensitivity ranged from 83.3% to 91.1% for the nonnasal sentence, from 70% to 78.4% for nasalance ratio and from 68.1% to 81.1% for nasalance distance. Specifity ranged from 87% to 93.1% for the nonnasal sentence, from 69.6% to 97.5% for nasalance ratio, and from 70.7% to 73.9% for nasalance distance. Conclusions. With a quick and gentle screening procedure, it is easily possible to identify hypernasal patients by an objective diagnostic tool of hypernasality, the NasalView system, with good reliability and validity.
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Temporomandibular joint dysfunction and orthognathic surgery: a retrospective study.
Head & face medicine. 11/2010; 6:27.
Relations between maxillo-mandibular deformities and TMJ disorders have been the object of different studies in medical literature and there are various opinions concerning the alteration of TMJ dysfunction after orthognathic surgery. The purpose of the present study was to evaluate TMJ disorders ch... [more] Relations between maxillo-mandibular deformities and TMJ disorders have been the object of different studies in medical literature and there are various opinions concerning the alteration of TMJ dysfunction after orthognathic surgery. The purpose of the present study was to evaluate TMJ disorders changes before and after orthognathic surgery, and to assess the risk of creating new TMJ symptoms on asymptomatic patients. A questionnaire was sent to 176 patients operated at the Maxillo-Facial Service of the Lille's 2 Universitary Hospital Center (Chairman Pr Joël Ferri) from 01.01.2006 to 01.01.2008. 57 patients (35 females and 22 males), age range from 16 to 65 years old, filled the questionnaire. The prevalence and the results on pain, sounds, clicking, joint locking, limited mouth opening, and tenseness were evaluated comparing different subgroups of patients. TMJ symptoms were significantly reduced after treatment for patients with pre-operative symptoms. The overall subjective treatment outcome was: improvement for 80.0% of patients, no change for 16.4% of patients, and an increase of symptoms for 3.6% of them. Thus, most patients were very satisfied with the results. However the appearance of new onset of TMJ symptoms is common. There was no statistical difference in the prevalence of preoperative TMJ symptoms and on postoperative results in class II compared to class III patients. These observations demonstrate that: there is a high prevalence of TMJ disorders in dysgnathic patients; most of patients with preoperative TMJ signs and symptoms can improve TMJ dysfunction and pain levels can be reduced by orthognathic treatment; a percentage of dysgnathic patients who were preoperatively asymptomatic can develop TMJ disorders after surgery but this risk is low.
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The impact of hyperbaric oxygen therapy on serological values of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF).
Head & face medicine. 01/2010; 6:29.
Hyperbaric oxygen (HBO) therapy is an effective adjunct treatment for ischemic disorders such as chronic infection or chronic wounds. It combines hyperoxic effects with the stimulating potential of post-therapeutic reactive hypoxia. As its crucial effects, stimulation of fibroblast growth, induction... [more] Hyperbaric oxygen (HBO) therapy is an effective adjunct treatment for ischemic disorders such as chronic infection or chronic wounds. It combines hyperoxic effects with the stimulating potential of post-therapeutic reactive hypoxia. As its crucial effects, stimulation of fibroblast growth, induction of collagen synthesis and the initiation of angiogenesis are discussed. Angiogenesis is a multistage process resulting in the growth of blood vessels. It includes degradation of extracellular matrix, proliferation and migration of different cell populations and finally formation of new vessel structures. This complex chain of procedures is orchestrated by different cytokines and growth factors. Crucial mediators of angiogenesis are basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF); their in-vivo function is still not fully understood. Forty-three patients suffering from sudden sensorineural hearing loss or tinnitus were treated with HBO. The therapy included 10 sessions of 90 minutes each, one session a day. Serological levels of bFGF and VEGF were assessed by enzyme-linked immunosorbent assays performed according to the manufacturer's instructions on day 1, 2, 5 and 10 of HBO therapy and were compared to mean values of the control group, related to the patient's age and sex, and their development observed over the ten days of HBO. There was no sex- or age dependency of bFGF observed in the present study, whereas under HBO our results showed a significant mitigation of the bFGF concentration. In the present data, there was no connection between the VEGF concentration and the patients' ages. Women showed significantly higher levels of VEGF. There was no significant change of VEGF concentration or the VEGF/bFGF ratio during HBO. All scored results varied within the range of standard values as described in the current literature. A significant effect of HBO on serum concentrations of bFGF and VEGF was not verified in the present study. Additional application of exogenous growth factors in conjunction with HBO was not obviously linked by a coherent cause-and-effect chain as far as wound healing is concerned.
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Release kinetics of VEGF165 from a collagen matrix and structural matrix changes in a circulation model.
Head & face medicine. 01/2010; 6:17.
Current approaches in bone regeneration combine osteoconductive scaffolds with bioactive cytokines like BMP or VEGF. The idea of our in-vitro trial was to apply VEGF165 in gradient concentrations to an equine collagen carrier and to study pharmacological and morphological characteristics of the comp... [more] Current approaches in bone regeneration combine osteoconductive scaffolds with bioactive cytokines like BMP or VEGF. The idea of our in-vitro trial was to apply VEGF165 in gradient concentrations to an equine collagen carrier and to study pharmacological and morphological characteristics of the complex in a circulation model. Release kinetics of VEGF165 complexed in different quantities in a collagen matrix were determined in a circulation model by quantifying protein concentration with ELISA over a period of 5 days. The structural changes of the collagen matrix were assessed with light microscopy, native scanning electron microscopy (SEM) as well as with immuno-gold-labelling technique in scanning and transmission electron microscopy (TEM). We established a biological half-life for VEGF165 of 90 minutes. In a half-logarithmic presentation the VEGF165 release showed a linear declining gradient; the release kinetics were not depending on VEGF165 concentrations. After 12 hours VEGF release reached a plateau, after 48 hours VEGF165 was no longer detectable in the complexes charged with lower doses, but still measurable in the 80 microg sample. At the beginning of the study a smear layer was visible on the surface of the complex. After the wash out of the protein in the first days the natural structure of the collagen appeared and did not change over the test period. By defining the pharmacological and morphological profile of a cytokine collagen complex in a circulation model our data paves the way for further in-vivo studies where additional biological side effects will have to be considered. VEGF165 linked to collagen fibrils shows its improved stability in direct electron microscopic imaging as well as in prolonged release from the matrix. Our in-vitro trial substantiates the position of cytokine collagen complexes as innovative and effective treatment tools in regenerative medicine and and may initiate further clinical research.
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Mandibular prognathism caused by acromegaly - a surgical orthodontic case.
Head & face medicine. 09/2009; 5(1):16.
ABSTRACT: A 22-year-old man presented for orthodontic surgery because of mandibular prognathism. Clinical symptoms suggested acromegaly, and diagnosis was verified by an endocrinologist as well as by radiograph. Bilateral mandibular prognathism often represents the first and most striking physical c... [more] ABSTRACT: A 22-year-old man presented for orthodontic surgery because of mandibular prognathism. Clinical symptoms suggested acromegaly, and diagnosis was verified by an endocrinologist as well as by radiograph. Bilateral mandibular prognathism often represents the first and most striking physical characteristic of acromegaly; usually, it is also the main reason why patients seek help from orthodontists or maxillo-facial surgeons. This case report recapitulates the clinical and histopathological findings in pituitary growth hormone (GH) adenomas and emphasises their importance in surgical orthodontic planning. Mandibular prognatism, macroglossia and abnormal growth of hands and feet represent strong indicators for the diagnosis of acromegaly. This disease and its complications not only affect the entire body but increase mortality if the pituitary gland tumour remains untreated.
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Analysis of expression profiles of MAGE-A antigens in oral squamous cell carcinoma cell lines.
Head & face medicine. 05/2009; 5(1):10.
ABSTRACT: BACKGROUND: The immunological response to solid tumours is insufficient. Therefore, tumour specific antigens have been explored to facilitate the activation of the immune system. The cancer/testis antigen class of MAGE-A antigens is a possible target for vaccination. Their differential exp... [more] ABSTRACT: BACKGROUND: The immunological response to solid tumours is insufficient. Therefore, tumour specific antigens have been explored to facilitate the activation of the immune system. The cancer/testis antigen class of MAGE-A antigens is a possible target for vaccination. Their differential expression profiles also modulate the course of the cancer disease and its response to antineoplastic drugs. METHODS: The expression profiles of MAGE-A2, -A3, -A4, -A6 and -A10 in five own oral squamous cell carcinoma cell lines were characterised by rt-PCR, qrt-PCR and immunocytochemistry with a global MAGE-A antibody (57B) and compared with those of an adult keratinocyte cell line (NHEK). RESULTS: All tumour cell lines expressed MAGE-A antigens. The antigens were expressed in groups with different preferences. The predominant antigens expressed were MAGE-A2, -A3 and -A6. MAGE-A10 was not expressed in the cell lines tested. The MAGE-A gene products detected in the adult keratinocyte cell line NHEK were used as a reference. CONCLUSIONS: MAGE-A antigens are expressed in oral squamous cell carcinomas. The expression profiles measured facilitate distinct examinations in forthcoming studies on responses to antineoplastic drugs or radiation therapy. MAGE-A antigens are still an interesting aim for immunotherapy.
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2.13Impact points
When Percutaneous Dilation Tracheotomy Maybe Hazardous: Abnormal Course of the Brachiocephalic Trunk.
Neurocritical care. 04/2009;
INTRODUCTION: Percutaneous dilatational tracheotomy (PDT) is becoming increasingly popular in present day critical care medicine. In contrast to the surgical approach, PDT involves a blind puncture and dilation of the pretracheal space, which may predispose to dangerous complications in the case of ... [more] INTRODUCTION: Percutaneous dilatational tracheotomy (PDT) is becoming increasingly popular in present day critical care medicine. In contrast to the surgical approach, PDT involves a blind puncture and dilation of the pretracheal space, which may predispose to dangerous complications in the case of anatomical, in particular vascular, anomalies. METHODS AND RESULTS: We report on two patients, in whom an abnormal pulsation was detected when the infracricoid region was palpated in preparation for PDT. An immediately performed ultrasound scan revealed an arterial blood vessel in front of the upper part of the trachea. A subsequent CT-angiography showed an anomalous course of the brachiocephalic trunk. While too dangerous for PDT, the local department of cranio-maxillofacial surgery was consulted for surgical tracheotomy. CONCLUSION: To avoid hazardous bleeding complications in PDT we recommend at least an ultrasound scan in case of an abnormal pulsation and an enlarged thyroid gland.
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Analysis of expression profiles of MAGE-A antigens in oral squamous cell carcinoma cell lines
Head & Face Medicine. 01/2009;
Abstract Background The immunological response to solid tumours is insufficient. Therefore, tumour specific antigens have been explored to facilitate the activation of the immune system. The cancer/testis antigen class of MAGE-A antigens is a possible target for vaccination. Their differential exp... [more] Abstract Background The immunological response to solid tumours is insufficient. Therefore, tumour specific antigens have been explored to facilitate the activation of the immune system. The cancer/testis antigen class of MAGE-A antigens is a possible target for vaccination. Their differential expression profiles also modulate the course of the cancer disease and its response to antineoplastic drugs. Methods The expression profiles of MAGE-A2, -A3, -A4, -A6 and -A10 in five own oral squamous cell carcinoma cell lines were characterised by rt-PCR, qrt-PCR and immunocytochemistry with a global MAGE-A antibody (57B) and compared with those of an adult keratinocyte cell line (NHEK). Results All tumour cell lines expressed MAGE-A antigens. The antigens were expressed in groups with different preferences. The predominant antigens expressed were MAGE-A2, -A3 and -A6. MAGE-A10 was not expressed in the cell lines tested. The MAGE-A gene products detected in the adult keratinocyte cell line NHEK were used as a reference. Conclusion MAGE-A antigens are expressed in oral squamous cell carcinomas. The expression profiles measured facilitate distinct examinations in forthcoming studies on responses to antineoplastic drugs or radiation therapy. MAGE-A antigens are still an interesting aim for immunotherapy.
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Ewing sarcoma of the mandible mimicking an odontogenic abscess - a case report.
Head & face medicine. 12/2008; 4(1):24.
ABSTRACT: Ewing sarcoma (ES) of the mandible is rare and can be mistaken for inflammation of dental origin. We present a 24-year old male patient which underwent radical tumour surgery and primary reconstruction with a microvascular osteoseptocutaneous free fibular flap as well as postoperative adju... [more] ABSTRACT: Ewing sarcoma (ES) of the mandible is rare and can be mistaken for inflammation of dental origin. We present a 24-year old male patient which underwent radical tumour surgery and primary reconstruction with a microvascular osteoseptocutaneous free fibular flap as well as postoperative adjuvant chemotherapy. Incomplete osseous tumour resection required a second intervention. This case report recapitulates the clinical and histopathological findings in oral ES, demonstrates its sometimes difficult diagnosis and discusses the (dis-)advantages of primary osseous reconstruction in ablative tumour surgery.
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1.67Impact points
Optimizing color reproduction of a topometric measurement system for medical applications.
Medical engineering & physics. 03/2008;
Integration of color information in 3D models acquired with a topometric measurement system opens a wide field of applications in medicine, e.g. prosthetics. To ensure an accurate and reliable color reproduction in a 3D topometric measurement system, different approaches have been evaluated. These t... [more] Integration of color information in 3D models acquired with a topometric measurement system opens a wide field of applications in medicine, e.g. prosthetics. To ensure an accurate and reliable color reproduction in a 3D topometric measurement system, different approaches have been evaluated. These techniques focus on the calibration of the CCD camera using color test charts by applying a polynomial regression method as well as numerical methods to compensate an intensity decay of the illumination in 3D datasets which is caused by varying distances and orientations of the measured object with respect to the light source. The methods presented in this contribution have been applied to a topometric measurement system with one-chip color CCD cameras. An enhanced color reproduction of various objects is demonstrated.
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The buccal minor salivary glands as starting point for a metastasizing adenocarcinoma--report of a case.
Head & face medicine. 02/2008; 4:16.
BACKGROUND: With the 2005 WHO classification of salivary gland tumours and its increasingly recognized diagnostic entities, the frequency of adenocarcinoma (NOS) has decreased significantly. CASE PRESENTATION: This paper describes a fast growing adenocarcinoma (NOS), originating from the minor saliv... [more] BACKGROUND: With the 2005 WHO classification of salivary gland tumours and its increasingly recognized diagnostic entities, the frequency of adenocarcinoma (NOS) has decreased significantly. CASE PRESENTATION: This paper describes a fast growing adenocarcinoma (NOS), originating from the minor salivary glands of the left buccal mucosa with a rapid onset of multiple local and distant metastases, especially in the lung. A lung primary was unlikely as the tumour was characterized by positivity for cytokeratin 20 and negativity for the thyroid transcription factor-1 protein (TTF-1) in immunohistochemistry. CONCLUSION: A rare case of an adenocarcinoma (NOS) of the minor salivary glands with a rapid development and an unfavourable clinical course is reported. It shows that additional immunohistochemical analysis can decisively contribute to determine the site of the primary tumour in cases with unknown primary.
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Oral acantholytic squamous cell carcinoma shares clinical and histological features with angiosarcoma.
Head & face medicine. 02/2008; 4:17.
BACKGROUND: acantholytic squamous cell carcinomas (ASCC) and intraoral angiosarcoma share similar histopathological features. Aim of this study was to find marker for a clear distinction. METHODS: Four oral acantholytic squamous cell carcinomas and one intraoral angiosarcoma are used to compare the ... [more] BACKGROUND: acantholytic squamous cell carcinomas (ASCC) and intraoral angiosarcoma share similar histopathological features. Aim of this study was to find marker for a clear distinction. METHODS: Four oral acantholytic squamous cell carcinomas and one intraoral angiosarcoma are used to compare the eruptive intraoral growth-pattern, age-peak, unfavourable prognosis and slit-like intratumorous spaces in common histological staining as identical clinical and histopathological features. Immunohistochemical staining for pancytokeratin, cytokeratin, collagen type IV, gamma2-chain of laminin-5, endothelial differentiation marker CD31 and CD34, F VIII-associated antigen, Ki 67-antigen, beta-catenin, E-cadherin, alpha-smooth-muscle-actin and Fli-1 were done. RESULTS: Cytokeratin-immunoreactive cells can be identified in both lesions. The large vascularization of ASCC complicates the interpretation of vascular differential markers being characteristic for angiosarcoma. Loss of cell-cell-adhesion, monitored by loss of E-cadherin and beta-catenin membrane-staining, are indetified as reasons for massive expression of invasion-factor ln-5 in ASCC and considered responsible for unfavourable prognosis of ASCC. Expression of Fli-1 in angiosarcoma and cellular immunoreaction for ln-5 in ASCC are worked out as distinguishing features of both entities. CONCLUSION: Fli-1 in angiosarcoma and ln-5 in ASCC are distinguishing features.
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Infraorbital cutaneous angiosarcoma: a diagnostic and therapeutic dilemma.
Head & face medicine. 02/2008; 4(1):18.
ABSTRACT: BACKGROUND: A cutaneous angiosarcoma is a rare malignant tumour of vascular endothelial cells with aggressive clinical behaviour and poor prognosis. Diagnosis is often delayed due to its variable and often benign clinical appearance. CASE PRESENTATION: This case presents a 64-year-old man ... [more] ABSTRACT: BACKGROUND: A cutaneous angiosarcoma is a rare malignant tumour of vascular endothelial cells with aggressive clinical behaviour and poor prognosis. Diagnosis is often delayed due to its variable and often benign clinical appearance. CASE PRESENTATION: This case presents a 64-year-old man with a six-month-history of a recurrent diffuse and erythematous painless swelling below the left eye. Several resections with intraoperatively negative resection margins followed, but positive margins were repeatedly detected later on permanent sections. Histopathologic examination of the specimen diagnosed a cutaneous angiosarcoma. Neither, finally achieved negative margins on permanent sections, nor a following chemotherapy could prevent the recurrence of the disease after five months and the patient's dead 21 months after the first diagnosis. CONCLUSION: The case elucidates the current diagnostic and therapeutic dilemma of this entity, which shows an unfavourable clinical course in spite of multimodal therapy.
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Oral acantholytic squamous cell carcinoma shares clinical and histological features with angiosarcoma
Head & Face Medicine. 01/2008;
Abstract Background acantholytic squamous cell carcinomas (ASCC) and intraoral angiosarcoma share similar histopathological features. Aim of this study was to find marker for a clear distinction. Methods Four oral acantholytic squamous cell carcinomas and one intraoral angiosarcoma are used to c... [more] Abstract Background acantholytic squamous cell carcinomas (ASCC) and intraoral angiosarcoma share similar histopathological features. Aim of this study was to find marker for a clear distinction. Methods Four oral acantholytic squamous cell carcinomas and one intraoral angiosarcoma are used to compare the eruptive intraoral growth-pattern, age-peak, unfavourable prognosis and slit-like intratumorous spaces in common histological staining as identical clinical and histopathological features. Immunohistochemical staining for pancytokeratin, cytokeratin, collagen type IV, γ2-chain of laminin-5, endothelial differentiation marker CD31 and CD34, F VIII-associated antigen, Ki 67-antigen, β-catenin, E-cadherin, α-smooth-muscle-actin and Fli-1 were done. Results Cytokeratin-immunoreactive cells can be identified in both lesions. The large vascularization of ASCC complicates the interpretation of vascular differential markers being characteristic for angiosarcoma. Loss of cell-cell-adhesion, monitored by loss of E-cadherin and β-catenin membrane-staining, are indetified as reasons for massive expression of invasion-factor ln-5 in ASCC and considered responsible for unfavourable prognosis of ASCC. Expression of Fli-1 in angiosarcoma and cellular immunoreaction for ln-5 in ASCC are worked out as distinguishing features of both entities. Conclusion Fli-1 in angiosarcoma and ln-5 in ASCC are distinguishing features.
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In vitro behaviour of endothelial cells on a titanium surface
Head & Face Medicine. 01/2008;
Abstract Background Endothelial cells play an important role in the delivery of cells to the inflammation site, chemotaxis, cell adhesion and extravasation. Implantation of a foreign material into the human body determines inflammatory and repair reactions, involving different cell types with a pl... [more] Abstract Background Endothelial cells play an important role in the delivery of cells to the inflammation site, chemotaxis, cell adhesion and extravasation. Implantation of a foreign material into the human body determines inflammatory and repair reactions, involving different cell types with a plethora of released chemical mediators. The evaluation of the interaction of endothelial cells and implanted materials must take into account other parameters in addition to the analysis of maintenance of cell viability. Methods In the present investigation, we examined the behavior of human umbilical vein endothelial cells (HUVECs) harvested on titanium (Ti), using histological and immunohistochemical methods. The cells, after two passages, were seeded in a standard density on commercially plate-shaped titanium pieces, and maintained for 1, 7 or 14 days. Results After 14 days, we could observe a confluent monolayer of endothelial cells (ECs) on the titanium surface. Upon one-day Ti/cell contact the expression of fibronectin was predominantly cytoplasmatic and stronger than on the control surface. It was observed strong and uniform cell expression along the time of α5β1 integrin on the cells in contact with titanium. Conclusion The attachment of ECs on titanium was found to be related to cellular-derived fibronectin and the binding to its specific receptor, the α5β1 integrin. It was observed that titanium effectively serves as a suitable substrate for endothelial cell attachment, growth and proliferation. However, upon a 7-day contact with Ti, the Weibel-Palade bodies appeared to be not fully processed and exhibited an anomalous morphology, with corresponding alterations of PECAM-1 localization.
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In vitro behaviour of endothelial cells on a titanium surface.
Head & face medicine. 01/2008; 4:14.
Endothelial cells play an important role in the delivery of cells to the inflammation site, chemotaxis, cell adhesion and extravasation. Implantation of a foreign material into the human body determines inflammatory and repair reactions, involving different cell types with a plethora of released che... [more] Endothelial cells play an important role in the delivery of cells to the inflammation site, chemotaxis, cell adhesion and extravasation. Implantation of a foreign material into the human body determines inflammatory and repair reactions, involving different cell types with a plethora of released chemical mediators. The evaluation of the interaction of endothelial cells and implanted materials must take into account other parameters in addition to the analysis of maintenance of cell viability. In the present investigation, we examined the behavior of human umbilical vein endothelial cells (HUVECs) harvested on titanium (Ti), using histological and immunohistochemical methods. The cells, after two passages, were seeded in a standard density on commercially plate-shaped titanium pieces, and maintained for 1, 7 or 14 days. After 14 days, we could observe a confluent monolayer of endothelial cells (ECs) on the titanium surface. Upon one-day Ti/cell contact the expression of fibronectin was predominantly cytoplasmatic and stronger than on the control surface. It was observed strong and uniform cell expression along the time of alpha5beta1 integrin on the cells in contact with titanium. The attachment of ECs on titanium was found to be related to cellular-derived fibronectin and the binding to its specific receptor, the alpha5beta1 integrin. It was observed that titanium effectively serves as a suitable substrate for endothelial cell attachment, growth and proliferation. However, upon a 7-day contact with Ti, the Weibel-Palade bodies appeared to be not fully processed and exhibited an anomalous morphology, with corresponding alterations of PECAM-1 localization.
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The role of apoptosis in early embryonic development of the adenohypophysis in rats.
Head & face medicine. 01/2008; 4:13.
Apoptosis is involved in fundamental processes of life, like embryonic development, tissue homeostasis, or immune defense. Defects in apoptosis cause or contribute to developmental malformation, cancer, and degenerative disorders. The developing adenohypophysis area of rat fetuses was studied at the... [more] Apoptosis is involved in fundamental processes of life, like embryonic development, tissue homeostasis, or immune defense. Defects in apoptosis cause or contribute to developmental malformation, cancer, and degenerative disorders. The developing adenohypophysis area of rat fetuses was studied at the embryonic stage 13.5 (gestational day) for apoptotic and proliferative cell activities using histological serial sections. A high cell proliferation rate was observed throughout the adenohypophysis. In contrast, apoptotic cells visualized by evidence of active caspase-3, were detected only in the basal epithelial cones as an introducing event for fusion and closure of the pharyngeal roof. We can clearly show an increasing number of apoptotic events only at the basic fusion sides of the adenohypophysis as well as in the opening region of this organ. Apoptotic destruction of epithelial cells at the basal cones of the adenohypophysis begins even before differentiation of the adenohypophyseal cells and their contact with the neurohypophysis. In early stages of development, thus, apoptotic activity of the adenohypophysis is restricted to the basal areas mentioned. In our test animals, the adenohypophysis develops after closure of the anterior neuroporus.
Following (11)
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Antonios Moralis
Universitätsklinikum Regensburg -
Joël Ferri
University nord de france lille 2 -
Wilfried Wagner
Johannes Gutenberg-University -
Hartwig Kosmehl
HELIOS Klinikum Erfurt -
Burkhard H Brandt
Universitätsklinikum Schleswig - Holstein
Topics (3)
