Overexpression of TACE and TIMP3 mRNA in head and neck cancer: association with tumour development and progression

BACKGROUND

TACE/ADAM17 is a transmembranous protease that cleaves membrane-bound growth factors like EGFR ligands. TACE-dependent proteolysis is regulated by its inhibitor, tissue inhibitor of metalloproteinases 3 (TIMP3). This study analyses the role of TACE and TIMP3 mRNA expression in squamous cell carcinomas of the head and neck (HNSCCs).

METHODS

We analysed TACE and TIMP3 mRNA expression in HNSCCs from 106 patients by RNA in situ hybridisation.

RESULTS

TACE mRNA was upregulated in HNSCCs compared with dysplastic (P<0.05) and normal epithelia (P<0.001), with strong hybridisation signals in 21.9% of invasive tumour tissues and 4.5% of dysplasia. Elevated mRNA levels were accompanied by increased amounts of TACE protein in HNSCCs. TIMP3 mRNA expression in HNSCC-associated stroma was significantly higher than in the stroma adjacent to dysplastic or normal epithelia. Expression of TACE mRNA in HNSCCs was associated with tumour stage (P=0.019) and regional lymph node metastasis (P=0.009). Furthermore, levels of TACE mRNA in HNSCCs correlated with the expression of TIMP3 mRNA in HNSCC-associated stroma. Concomitantly, patients expressing high levels of TACE and TIMP3 mRNA showed significantly reduced overall survival compared with those with low mRNA levels.

CONCLUSION

Our results indicate an important role of TACE and TIMP3 during development and progression of HNSCCs.

Hypercementosis and odontogenic epithelial hyperplasia associated with a tooth root remnant mimicking a neoplasm. A case report

Hypercementosis presents as painless, single or multiple non-neoplastic cementum formation beyond the physiological limits of the tooth. It often occurs in the apical area of the involved tooth following infection, chemical or mechanical trauma. We report on radiographic and histopathological findings in a single case of late intraosseous hypercementosis and odontogenic epithelial hyperplasia associated with a minute apical tooth root remnant years after its extraction, mimicking a tumour.

Clinical characterisation of 29 neurofibromatosis type-1 patients with molecularly ascertained 1.4 Mb type-1 NF1 deletions

BACKGROUND

Large deletions of the NF1 gene region occur in approximately 5% of patients with neurofibromatosis type-1 (NF1) and are associated with particularly severe manifestations of the disease. However, until now, the genotype-phenotype relationship has not been comprehensively studied in patients harbouring large NF1 gene deletions of comparable extent (giving rise to haploinsufficiency of the same genes).

METHOD

We have performed the most comprehensive clinical/neuropsychological characterisation so far undertaken in NF1 deletion patients, involving 29 patients with precisely determined type-1 NF1 (1.4 Mb) deletions.

RESULTS

Novel clinical features found to be associated with type-1 NF1 deletions included pes cavus (17% of patients), bone cysts (50%), attention deficit (73%), muscular hypotonia (45%) and speech difficulties (48%). Type-1 NF1 deletions were found to be disproportionately associated with facial dysmorphic features (90% of patients), tall stature (46%), large hands and feet (46%), scoliosis (43%), joint hyperflexibility (72%), delayed cognitive development and/or learning disabilities (93%) and mental retardation (IQ<70; 38%), as compared with the general NF1 patient population. Significantly increased frequencies (relative to the general NF1 population) of plexiform neurofibromas (76%), subcutaneous neurofibromas (76%), spinal neurofibromas (64%) and MPNSTs (21%) were also noted in the type-1 deletion patients. Further, 50% of the adult patients exhibited a very high burden of cutaneous neurofibromas (N>or=1000).

CONCLUSION

These findings emphasise the importance of deletion analysis in NF1 since frequent monitoring of tumour presence and growth could potentiate early surgical intervention thereby improving patient survival.

Expression and distribution of tenascin in rat submandibular glands following irradiation

The aim of this study was to investigate the late changes in the expression of tenascin-C (TN-C) in salivary glands (SG) following irradiation (IRR).

MATERIALS AND METHODS

In 124 submandibular SG from 62 Wistar rats, the effect of IRR dose (fractionated IRR, 2 Gy per day, total dose of 20, 40, or 60 Gy), time since IRR (6 months vs. 12 months), and animal age (1 year vs. 1.5 years) on TN-C expression profile and its distribution pattern was investigated.

RESULTS

Expression of TN-C showed slight to moderate alterations in the irradiated specimens. The expression differed in frequency and degree among various tissue structures. The most striking finding was pronounced dose-dependent heterogeneity, with increases, decreases and fluctuations in staining.

CONCLUSION

The staining of TN-C predominantly showed notable dose-dependent heterogeneity, persisting for up to 1 year after completion of IRR. Thus, these findings can be attributed to late radiation effects. The altered expression of tenascin-C may play at least a partial role in late radiogenic dysfunction of the submandibular SG.

High bone turnover and accumulation of osteoid in patients with neurofibromatosis 1

Although it is known that neurofibromatosis 1 (NF1) patients suffer from vitamin D deficiency and display decreased bone mineral density (BMD), a systematic clinical and histomorphometrical analysis is absent. Our data demonstrate that NF1 patients display high bone turnover and accumulation of osteoid and that supplementation of vitamin D has a beneficial effect on their BMD.

INTRODUCTION

Neurofibromatosis 1 results in a wide range of clinical manifestations, including decreased BMD. Although it has been reported that NF1 patients have decreased vitamin D serum levels, the manifestation of the disease at the bone tissue level has rarely been analyzed.

METHODS

Thus, we performed a clinical evaluation of 14 NF1 patients in comparison to age- and sex-matched control individuals. The analysis included dual X-ray absorptiometry osteodensitometry, laboratory parameters, histomorphometric and quantitative backscattered electron imaging (qBEI) analyses of undecalcified bone biopsies.

RESULTS

NF1 patients display significantly lower 25-(OH)-cholecalciferol serum levels and decreased BMD compared to control individuals. Histomorphometric analysis did not only reveal a reduced trabecular bone volume in biopsies from NF1 patients, but also a significantly increased osteoid volume and increased numbers of osteoblasts and osteoclasts. Moreover, qBEI analysis revealed a significant decrease of the calcium content in biopsies from NF1 patients. To address the question whether a normalization of calcium homeostasis improves BMD in NF1 patients, we treated four patients with cholecalciferol for 1 year, which resulted in a significant increase of BMD.

CONCLUSION

Taken together, our data provide the first complete histomorphometric analysis from NF1 patients. Moreover, they suggest that low vitamin D levels significantly contribute to the skeletal defects associated with the disease.

Malignant peripheral nerve sheath tumors (MPNST) in NF1-affected children

BACKGROUND

Malignant peripheral nerve sheath tumors (MPNST) constitute a heterogeneous group of malignant tumors that probably arise from cells of the peripheral nerve sheath. Association of MPNST with neurofibromatosis type 1 (NF1) is frequently reported. MPNST contribute significantly to the reduced life-span of NF1-patients. At present there are only sparse data on MPNST in NF1-children. The aim of this study was to determine the outcome of children affected with NF1 who developed an MPNST.

MATERIALS AND METHODS

Over the period of 1985 to 2005, we followed 52 NF1 patients with MPNST at our outpatient department. All patients were diagnosed and re-evaluated according to the updated NIH diagnostic criteria for NF1.

RESULTS

Out of this cohort, 8 patients with MPNST were aged 1 to 17 years at the time of MPNST diagnosis (mean age: 12 years; 5 girls and 3 boys). We noticed the following characteristics: MPNST arose from plexiform neurofibromas (PNF) with invasive or displacing growth pattern on MRI. Many patients reported pain and neurological deficits at the time of presentation. Diagnosis of MPNST in this age group took longer compared to adults. This cohort did not show longer survival periods than adults with MPNST. Adjunctive treatment with chemotherapy or radiation had no lasting effect. The overall survival time of this small cohort was 30.5 months. Those children who died showed a median survival time after diagnosis of 20 months. The longest survival of 112 months was achieved for a girl who presented with MPNST of the distal upper arm and underwent amputation. The NF1 mutation analysis in the MPNST pediatric age group revealed the same mutational spectrum as the adult group.

CONCLUSION

Our data reveal MPNST in children with NF1. Children cannot verbalize physical alterations adequately; therefore the correct diagnosis might be hampered in these patients. Unresolved complaints of children with NF1 should be investigated thoroughly due to the risk for malignancy in NF1.

Navigation-assisted resection of a primary extraocular melanoma of the orbit

A 22-year-old male presented with proptosis of the right eye and diplopia. On magnetic resonance images (MRI), a well-delineated orbital tumor medio-distal to the eye was detected, respecting the eye-ball and the orbital walls. The aim of navigation-assisted surgery was to excise the progressive tumor while maintaining vision. A modified latero-cranial orbitotomy was used to approach the tumor. Microscopic analysis of the resection specimen revealed a melanoma. The patient's postoperative course was uneventful. The diplopia improved rapidly. Two further eye-saving second-look revisions of the tumor site excluded further melanoma infiltrates and revealed melanophages in scar tissue. Intraoperative navigation was used during all procedures. The tumor showed some interesting features concerning its histopathological appearance and magnetic resonance imaging. Detailed histopathological investigations supported the decision for organ-saving surgery. Follow-up MRI and positron emission tomograms up to 14 months later showed neither local tumor recurrence nor distant spread.

CONCLUSION

In the presented case with the incidental finding of orbital melanoma without invasion of the globe or orbital walls, navigation-assisted surgery supported the eye-saving operating procedures.

Clinical relevance of positron emission tomography and magnetic resonance imaging in the progression of internal plexiform neurofibroma in NF1

Neurofibromatosis type 1 (NF1) is a frequent and inherited disease with a predisposition for malignant peripheral nerve sheath tumor (MPNST) development. MPNST are soft tissue sarcomas that arise from peripheral nerves, being one of the most aggressive malignancies in humans with extremely poor prognosis. MPNST frequently arise from a previously undetected plexiform neurofibroma (PNF). The malignant transformation of an internal PNF to an MPNST is difficult to assess and requires advanced imaging techniques like magnetic resonance imaging or positron emission tomography. Despite the high quality of current diagnostics, the changing tumor biology inside a plexiform neurofibroma cannot currently be visualized accurately. We report 4 cases of NF1 patients with PNF who showed imaging findings suspicious for malignant degeneration, but proved to have MPNST in only one case. Three tumors might represent an intermediate type between PNF and MPNST. Ablative surgery and complete histological work-up of specimens is the only way to clarify tumor status, thereby enabling provision of adequate local treatment.

Expression and distribution of cytokeratins and vimentin in rat larynx and trachea following irradiation

BACKGROUND

External irradiation (IRR) of advanced head and neck tumors often includes tissues of the larynx and trachea unaffected by cancer. In these normal tissues, both single-cell damage (necrosis, apoptosis, functional cell death) and interstitial damage (edema, fibrosis, vascular alterations, cellular infiltrations) resulting in tissue remodeling can occur, depending on various IRR parameters. However, reports on radiogenic intermediate filament protein alterations in laryngeal-tracheal tissues are very rare. In this study, we investigated the phenotypic characterization of the normal integrity-supporting cytokeratins (CK) and vimentin following a clinically relevant IRR protocol in laryngeal-tracheal tissues.

MATERIALS AND METHODS

In 61 laryngo-tracheal specimens from Wistar rats the expression profile and distribution pattern of CK (CK13, CK17/19, CK18) and vimentin were investigated according to IRR dose (fractionated IRR, 2 Gy per day, total dose of 20, 40 or 60 Gy), time from IRR (6 months vs. 12 months) and animal age (1 year vs. 1.5 years) using immunohistochemical methods, semiquantitative assessment and multivariate analysis.

RESULTS

In irradiated specimens, expression of both CK and vimentin showed slight to moderate dose-dependent alterations. The expression differed in frequency and level among the various tissue structures and showed remarkable heterogeneity, with increases, decreases and fluctuations in staining. In the glottic mucosal layer (non-keratinizing squamous epithelium), CK13 expression decreased with increasing dose. The CK17/19 expression of supra- and subglottic respiratory epithelia following 20 and 60 Gy exposure was significantly lower than in controls. The respiratory epithelia and, in part, the cuboidal epithelia of the indifferent type at the inner side of the aryepiglottic fold revealed increasing CK17/19 immunoreactions up to 40 Gy IRR, but a distinct decrease in expression at 60 Gy. In subglottic gland structures, CK18 was detected at significantly higher levels than in controls. There was increasing expression with increasing dose. CK18 reactions of supra- and subglottic respiratory mucosal layer, supraglottic gland structures and thyrocytes tended towards increasing expression with increasing dose and in older animals. Tracheal mucosal epithelia, tracheal glands, and respiratory epithelia of the inner side of the aryepiglottic fold tended towards decreasing expression of CK18 with increasing dose and in older animals. In part, these tissues showed dose-dependent fluctuations. Furthermore, the vimentin reactions showed dose-dependent, heterogeneous patterns, with increases, decreases, and fluctuations in staining. Moreover, there were differences in frequency and intensity of expression among the various tissue structures. Age and time from IRR had no significant effect on immunoreaction.

CONCLUSION

The staining of CK and vimentin predominantly showed a notable dose-dependent heterogeneity, with increases, decreases and fluctuations in expression. The expression pattern persisted for up to 1 year after the completion of irradiation. Thus, these findings must reflect late radiation effects. The altered expression of CK and vimentin may play at least a partial role in structural (e.g. edema) and functional (e.g. voice disorders) changes associated with irradiation of the head and neck.

Mutagenicity testing of mouthwash brands

Several mouthwash brands were investigated for the evaluation of mutagenicity and cell-transforming activity in short-term mutagenicity test systems. The tests were: the Salmonella typhimurium mutagenicity assay (Ames tests), the unscheduled DNA-repair induction assay in primary rat hepatocytes (UDS-test), and the V79-HGPRT mutagenicity assay. Mouthwash, with and without an external metabolic activation system (S9), consistently showed no mutagenic or cytotoxic activity in the Ames test, UDS assay or the V79-HGPRT-assay. These results indicate that the tested mouthwash brands are unlikely to present a mutagenic or carcinogenic hazard. However, these findings derived from an in vitro study cannot imitate the situation in situ, where a plethora of pharmacologically or bio-chemically active agents pass the oral cavity, thereby reacting with each other and the oral mucosa, in particular when the use of such rinses occurs regularly over a long-term period.

Expression of insulin-like growth-factor-1 receptor (IGF-1R) in peripheral nerve sheath tumors in neurofibromatosis type 1

BACKGROUND

Neurofibromatosis type 1 (NF1) is an autosomal-dominant inherited disease, characterised by the development of nerve sheath tumors. NF1 is the most frequently inherited disease associated with a predisposition for cancer (in particular malignant peripheral nerve sheath tumors: MPNST). NF1 is a progressive disease with phase-like growth spurts of dermal or plexiform neurofibroma (PNF). These tumors can cause severe disfigurement of patients. Growth control of these tumors is poorly understood. The aim of this study was to identify the expression of insulin-like growth factor 1-receptor (IGF-1R) in peripheral nerve sheath tumors. Factor and receptor are involved in the growth control of numerous physiological and pathological processes, including Schwann cell development.

MATERIALS AND METHODS

The investigation included tumors of NF1-patients only (neurofibroma, MPNST). Sections of the specimens were immunohistochemically typed for several antigens (target antigens: IGF-1R, S-100, EMA, CD34, MIB-1), using both single and double-staining methods. Double-staining allowed the sub-typing of the IGF-1R-expressing cells in the mixed nerve sheath tumors. The expression was also investigated in Schwann cell cultures and co-cultures with fibroblasts.

RESULTS

Staining of S-100 and IGF-1R, PNF were more intensely marked than MPNST (r = -0.439, p < 0.002, N = 49). The proliferation index was tumor-type dependent: MPNST > neurofibroma. The IGF-1R-expression correlated positively with the MIB-1 index in neurofibroma (r = 0.372, p = 0.021, N = 38). The receptor expression was higher in PNF than in dermal neurofibroma (r = 0.335, p = 0.040, N = 38). IGF-1R was detected in Schwann cells (S-100 positive) and in perineurial cells (EMA-positive) of all nerve sheath tumors. However, the receptor was also identified in CD34-marked endothelia of neurofibromas but not in endothelia of MPNST. In Schwann cell cultures, a strong receptor-expression became evident. This expression was independent of co-cultivation of tumor cells with fibroblasts. The statistical calculations excluded the impact of gender on the receptor expression.

CONCLUSION

This investigation provides evidence for the expression of IGF-1R in nerve sheath tumors in NF1. The expression pattern varied between the tumor types, the cell types, and between tumors of the same type. IGF and IGF-1R are a prerequisite to maintain Schwann cell stability in the postnatal period and to prevent Schwann cell apoptosis. The first evidence for IGF-1R expression in mutated Schwann cells may indicate a tumor-type associated receptor expression in NF1.

Vitamin D deficiency associated with number of neurofibromas in neurofibromatosis 1

Neurofibromatosis 1 (NF1) is a tumour suppressor gene syndrome characterized by multiple cutaneous and plexiform neurofibromas. Focal osseous abnormalities, short stature, and decreased bone mineral density are also frequent in people with NF1. We measured serum 25-hydroxyvitamin D concentrations in 55 patients with NF1 and 58 healthy controls, and correlated the findings in the patients with NF1 with their estimated number of dermal neurofibromas. Geometric mean (SD) serum 25-hydroxyvitamin D concentration was 14.0 (1.6) ng/mL among the patients with NF1 compared with 31.4 (1.7) ng/mL among healthy controls (p<<0.0001). The serum vitamin D concentration and number of dermal neurofibromas reported by patients with NF1 were inversely correlated (Spearman's rho = -0.572, p<0.00001). The occurrence of low serum vitamin D concentrations in people with NF1, especially those with many dermal neurofibromas, may provide new pathogenic insights and have important therapeutic implications.

MRI growth patterns of plexiform neurofibromas in patients with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with an incidence of 1:3000. Approximately 30% of NF1 patients develop plexiform neurofibromas (PNF) which often cause severe clinical deficits. We studied the growth patterns of 256 plexiform neurofibromas (PNF) by magnetic resonance imaging (MRI) and associated disfigurement and functional deficits to determine whether there are definable growth types of these tumors. Retrospectively, we evaluated MRI scans obtained during 1997 to 2003 of 256 plexiform neurofibromas from 202 patients with NF1. Clinical investigation was carried out at the same time as the MRI scans. We identified three growth patterns: superficial in 59, displacing in 76, and invasive growth in 121 tumors. The majority (52%) of invasive PNF were found in the face, head and neck area. While superficial PNF primarily caused aesthetic problems, displacing PNF led in most cases to aesthetic problems and pain, while invasive PNF led mainly to functional deficits and disfigurement. Our study demonstrates that PNF have different growth patterns that are associated with specific clinical features. Classification of PNF may open new opportunities in clinical management, especially regarding decisions and options associated with surgical intervention.

[The eruption times of permanent teeth in boys and girls in the Stormarn District, Schleswig-Holstein (Germany)]

In a longitudinal study in two small towns in southern Schleswig-Holstein (Ammersbek and Ahrensburg, District Stormarn; 9155 inhabitants) we investigated 2832 oral findings of 1396 patients (711 males, 685 females). The minimum age was 1.51 years, and the maximum age was 25.50 years. The dental findings were collected over a period of about 20 years (1982-2002). The oral findings per child were assessed between one and eight times. The eruption times of teeth in females are earlier than those for the same teeth in males. Further, the permanent dentition in females is completed earlier than in males. In both sexes the tooth eruption occurs symmetrically in both jaws. The comparison of both jaws revealed a slightly advanced eruption of the lower jaw teeth in both sexes. There is a noteworthy change in the eruption sequence of the teeth. In contrast to other reports we observed that the eruption of the canine proceeds the eruption of the second molar. We found no acceleration of the dentition when compared with other reports and could confirm the rules of tooth eruption in man.

CONCLUSION

Oral examination of teeth is a simple tool to calculate tooth eruption intervals. This first investigation on a population of Schleswig-Holstein revealed a change in the eruption sequence of permanent teeth. These findings are relevant for dental treatment planning and should be reconfirmed at certain intervals.

Hyperfractionated externally irradiated primary oral squamous cell carcinomas: vital tumor cells in resection specimens

Oral squamous cell carcinoma (OSCC) is among the most frequent malignancies worldwide. Ablative surgery for OSCC is the therapy of choice, however, severe disfigurement and loss of function is a consequence of therapy. On the other hand, R0-resection margins following ablative surgery do not guarantee disease-free survival, in particular due to the widespread, interconnecting lymphatic vessels. Therefore, irradiation of the primary and efferent lymphatics is a valuable therapeutic alternative to surgery. The combination of both irradiation and surgery might even improve overall survival. It has been argued that curatively planned irradiation (isodose of the primary: 60-70 Gy) might not routinely be followed by ablative surgery. Indeed, the sequelae of surgery in an irradiated field are well known. The aim of this study was to determine vital tumor cells in the resection specimens of irradiated advanced stage OSCC in order to estimate the effect of radiotherapy.

MATERIALS AND METHODS

One hundred patients (male 78, female: 22, mean age 60.2 years) with primary OSCC (T2: n=41, T3: n=26; T4: n=33) and suspected regional lymph node metastases were externally irradiated up to a total dosage of 70 Gy (single dose 1.4 Gy, twice daily, minimum daily interval 6 hours; 5 days a week). Ablative surgery followed radiotherapy about 3 months later.

RESULTS

In 51% of the primaries, specimens showed vital tumor cells after completion of radiotherapy. The evidence of vital tumor cells increased with T-stage and with N-stage, but showed no correlation to grading.

CONCLUSION

Irradiation of the head and neck region following a hyperfractionation scheme for the treatment of advanced stage OSCC offers a 50% chance of deletion of malignant cells. Despite high total dosages and sophisticated irradiation protocols, the number of patients with vital tumor cells is high. Short-term follow-up controls are mandatory in patients who were subjected to a primary radiotherapy. Ablative surgery following irradiation is a salvage option for pre-irradiated OSCC patients.

Diagnosis, treatment and follow-up control in 124 patients with basal cell carcinoma of the maxillofacial region treated from 1992 to 1997

AIM

The aim of this study was to analyze diagnostic and therapeutic procedures and the outcome of patients treated for the most common malignant tumor of the facial skin, basal cell carcinoma.

PATIENTS AND METHODS

The files of patients with basal cell carcinoma (BCC) treated over a period of 6 years were evaluated. Emphasis was placed on the frequency of second interventions, local recurrences and histological subtyping of tumors.

RESULTS

One-hundred and twenty-four patients were treated for 216 basal cell carcinomas (solitary: 67%, multiple: 33%). The tumors were predominantly located in the skin covering the middle third of the face. The tumors were 30 mm or less in diameter in 86%. Treatment was exclusively surgical. Histopathological subtyping revealed solid (83%), sclerodermiform (10%), metatypical (4%) and multicentric (3%) tumors. Resection of adjacent bone was mandatory in 12 patients and orbital exenteration in 2. Further local resections were necessary after thorough histological investigation in 71% of patients. Local recurrences occurred in 14 patients, predominantly within the first year after ablative surgery. Relative to the small number of sclerodermiform BCC, this subtype was the most frequent tumor that developed local recurrences.

CONCLUSION

Basal cell carcinoma is a malignant tumor, slowly growing and often showing wide extension to macroscopically non-affected sites. Resection of tumors is delicate in the maxillofacial region due to the predilection for sites of origin adjacent to structures of eminent importance for facial appearance. The sclerodermiform subtype is prone to local recurrence and these patients should be followed up carefully.

Eruption times of permanent teeth in children and young adolescents in Athens (Greece)

In a study in Athens, Greece, during the summer of 2003, 2,304 patients (1,168 boys and 1,176 girls) were examined by a young dentistry. The examination occurred within the framework of a routine dental check-up performed at the National and Kapodistrian University of Athens. The age span ranged from 3.00 to 24.93 years of age. Sex, age and present permanent teeth were recorded. Wisdom teeth were excluded. The sequence of tooth eruption differs significantly in the lower and upper jaw, whereas no significant differences existed when comparing the sides of each jaw. The tooth eruption in the lower and upper jaw of male and female probands is symmetrical. In comparing the upper and the lower jaw of both genders, it becomes evident that there is a tendency for earlier tooth eruptions in the lower jaw. In respect to the tooth eruption sequence, a change was noted in the upper jaw. Contrary to the reports of other authors, the second premolar has changed places with the canine and erupts prior to this tooth. This could also be demonstrated in recent studies from New York and Bremen (Germany). Otherwise no major differences concerning the sequence of tooth eruptions were observed, when compared with the results gained from other populations. Concerning the entire dentition, no acceleration of the tooth eruption could be noted. The computed differences of teeth eruption as a mean value calculated over all teeth was +/-1 year at maximum, compared with studies from different continents. Oral examination of teeth is a simple tool to calculate tooth eruption intervals. This first investigation in a population of Athens revealed a change in the eruption sequence of permanent teeth. These findings are relevant for dental treatment planning and should be reconfirmed at certain intervals.

Eruption times of permanent teeth in teenage boys and girls in Izmir (Turkey)

In a study in the Aegean city of Izmir, Turkey, during the summer of 2002, 2101 patients (1046 boys and 1055 girls) were examined. The examination occurred within the framework of a dental check-up performed at two schools and one pre-school unit. The age span ranged from 3.98 to 24.91 years. Sex, age and present permanent teeth were recorded. Wisdom teeth were excluded. The sequence of tooth eruptions differs significantly in the lower and upper jaw, whereas no significant differences existed when comparing the sides of each jaw. The times of tooth eruption is earlier in females than in males. The entire tooth eruption process of the second dentition occurs in females earlier than in males. The tooth eruption in the lower and upper jaw of male and female probands is symmetrical. In comparing the upper and the lower jaw of both genders, it becomes evident that there is a tendency for earlier tooth eruptions in the lower jaw. In respect to the tooth eruption sequence, a change was noted in the upper jaw. Contrary to the reports of other authors, the second premolar has changed places with the canine and erupts prior to this tooth. Otherwise no major differences concerning the sequence of tooth eruptions, when compared to the results gained from other populations, were observed. Concerning the entire dentition, no acceleration of the tooth eruption could be noted. The computed differences of teeth eruption as a mean value calculated over all teeth, was +/- 1 year at maximum, compared to studies from different continents. Oral examination of teeth is a simple tool to calculate tooth eruption intervals. This first investigation on a population of Izmir revealed a change in the eruption sequence of permanent teeth. These findings are relevant for dental treatment planning and forensic odontology and should be reconfirmed at certain intervals.

[Sonography as a training tool for screening of dubious midfacial fractures]

BACKGROUND

In uncertain midfacial fractures, sonography is an alternative first-line imaging modality to conventional radiographs. Patients with sonographically confirmed fractures can then be directly admitted to three-dimensional imaging, resulting in decreased radiation exposure since the conventional radiographs are omitted.

MATERIAL AND METHODS

Using a high-frequency linear and curved array scanner in a healthy proband, images of the zygomatic arch, anterior maxillary sinus wall, infraorbital rim, and lateral orbital wall were obtained. For identification and anatomical allocation corresponding navigated ultrasound images of a reference skull were generated and fused with a segmented CT data set. Navigated sonography was reproduced in a patient with orbitozygomatical fracture of the left side. Therefore, the CT data set, performed during preoperative diagnostics, was fused with the ultrasound images.

RESULTS

Because of different coupling shapes, the high-frequency linear array scanner was subjectively found to be more suitable for sonography in the field of the zygomatic arch, anterior maxillary sinus wall, and infraorbital rim, and the curved array scanner was better suited for transbulbar sonography of the orbital walls. After coupling sonography with the navigation system and referencing the scanner, it was possible to verify ultrasound findings objectively by navigation of the scanner and fusion with the CT data set. Using the reference skull, ultrasound images corresponding to normal findings were obtained and with the fused CT data, providing colored segmentation of the facial bones, an anatomically correct identification was possible. Clinical application of this tool is described in a patient with left-sided orbitozygomatical fracture.

CONCLUSION

By fusion of ultrasound images and corresponding CT data with the help of a navigation system, a sonographic training tool for preliminary evaluation of midfacial fractures is available.

[Calcifying epithelial odontogenic tumor of the maxilla (Pindborg tumor)]

A male patient presented with an extraordinarily large calcifying epithelial odontogenic tumor (CEOT or Pindborg-tumor) that affected the maxilla. The disease became evident due to alterations in the facial aspect, in particular of the perioral region, caused by the expanding tumor. CEOT is characterised by the slowly growing mass of part of the jaws. Multilocular or extraosseous manifestations are extremely rare. Malignant transformation with metastases is rare. Radiography depicts characteristic, but not obligatory, areas of calcification inside the tumor. The surgical therapy for CEOT is complete local resection with safe margins. If tooth bearing parts of the jaws are affected, these teeth almost always have to be removed. The prognosis is excellent for overall survival. Local recurrences have rarely been reported but may be found even decades after primary treatment. Three years following surgical therapy there is no evidence of local recurrence. A long-term follow-up control is recommended.

DNA-flow cytometry, DNA-image cytometry and proliferation index (MIB-5) in irradiated rat salivary glands and salivary gland tumors

AIM

Salivary glands (SG) can become atrophic following radiation exposure. Malignant transformation of SG in a radiation field is another known sequela of patients who have been treated by radiotherapy for a malignant tumor in the head and neck region. The aim of this study was to investigate cytogenetic alterations and to determine the proliferation index (PI) of SG of rats subjected to various total dosages of fractionated X-rays.

MATERIALS AND METHODS

We investigated rat SG, subjected to 20, 40, or 60 Gy exposure by X-rays to the left neck and skull base. Non-irradiated rats served as a control group. Tumors originating from the SG were histologically-diagnosed following the descriptions for human SG tumors. The MIB-5 antibody was used to determine the PI. The ploidy was determined by flow and image cytometry (FCM, ICM).

RESULTS

We consistently recorded diploid histograms in the FCM in irradiated glands. ICM revealed aneuploid histograms in 6/22 tumors, 3 of them were Auer Type III or IV. The PI showed a dose- and time-dependent course, indicative of variable regeneration properties of the parenchyma. Statistically significant differences were found for the PI within the irradiation groups and comparing irradiated SG and tumors.

CONCLUSION

Irradiation of rat SG can cause almost complete loss of function. On the other hand, the PI remained in animals subjected to 40 Gy and investigated 1 year after completion of radiation at a level up to 10-fold higher than in untreated controls. The PI in carcinoma is higher in this species than in irradiated SG. Constantly elevated PI could support the development of cancer in SG.

Expression of multi-drug resistance genes (mdr1, mrp1, bcrp) in primary oral squamous cell carcinoma

The expression of resistance genes can cause the ineffectiveness of chemotherapeutics for the treatment of cancer. Therefore, known resistance genes were investigated in oral squamous cell carcinoma (OSCC) and the results were compared with clinico-pathological findings.

MATERIALS AND METHODS

Fresh frozen samples of 45 primary OSCC were investigated for the expression of mdr1 (p-glycoprotein-mediated multi-drug resistance), mrp1 (multi-drug resistance-related protein) and bcrp (breast cancer-related protein), using a reverse transcriptase PCR. The gene products were revealed immunohistochemically on representative slices of the same tumor sample. The results were compared with TNM stage grouping [SG, (UICC, 1987)], HPV infection and p53 mutations (exons 5-8).

RESULTS

The expression of the resistance genes was independent of age, sex, localisation of the tumor, HPV infection and p53 mutations. SG did not correlate to mdr1 and mrp1. On the other hand, bcrp expression increased 2.7-fold between SG III and IV OSCC. Loss of differentiation was associated with an increased expression of mdr1 (p=0.06), mrp1 (p<0.01) and bcrp (p<0.01). The bcrp expression correlated with shorter survival periods. Expression of mrp1 and mdr1 did not correlate positively in a linear pattern. Expression of mdr1 and bcrp moderately positively correlated (p<0.01).

DISCUSSION

Multi-drug resistance genes can be up-regulated in OSCC. The expression of at least one of these genes is up-regulated in SG-IV OSCC. Determining these genes could probably support current studies on therapeutic effects in OSCC, e.g. new cytostatic drugs.

Oral lichen planus in patients with chronic liver diseases

BACKGROUND

The possible increased risk of oral lichen planus (OLP) in patients with chronic liver diseases is a controversial issue.

PATIENTS AND METHODS

We investigated a total of 156 outpatients with known liver diseases for occurrence of OLP. Hepatitis C virus (HCV) infection was proven for 117 patients (75%) and hepatitis B virus (HBV) infection for 16 patients (10.3%). Four patients were coinfected with HCV and HBV. An alcohol-derived hepatic cirrhosis was found in 23 patients (14.7%). Three patients had a biliary cirrhosis and one had a primary sclerosing cholangitis. Patients suspected of having OLP were transferred to the Department of Oral and Maxillofacial Surgery where excisional biopsies were taken.

RESULTS

Eight patients had a white alteration of the oral mucosa. OLP was suspected in five of them and was confirmed histologically in four. The alteration of the fifth patient disappeared during continued interferon therapy.

CONCLUSION

Our results show that there is no increased prevalence of OLP manifestation in patients suffering from HCV infection.

Investigation about origin and spreading of neoendothelium in autologous arterial vessel replacement

INTRODUCTION

In many fields of surgery an autologous arterial vessel replacement is used. Because of trauma and insufficient nutrition, a loss of complete endothelium in the replaced vessel segment and at the anastomoses can be observed within a few hours. The origin and the spread of the neoendothelium are unknown. Our study uses Von-Willebrand-protein, a product of endothelium cells, as a marker to obtain new information about the origin and spread of the new endothelial cells.

MATERIALS AND METHODS

Seventy Wistar rats, seven groups of 10 animals each, were operated. A four-millimetre-long segment of the common carotid artery was isolated and reinserted. After a varying length of time (between directly after the operation and six months after), the common carotid artery including bifurcation was isolated after cardioperfusion. Carotid arteries were embedded and cross-sections were stained with hematoxylineosin, Verhoeff's tissue elastin stain and immunohistochemical anti-Von-Willebrand-factor-antibody. The complete vessel was divided into nine points of measurement on each side, three points at each anastomosis and three points in transplanted segment. There the number of positive endothelial cells was rated.

RESULTS

Twenty-four hours after the operation no further endothelium was detectable in autologous transplant. Stainings eight days after operation contained Von-Willebrand-factor-positive cells in luminal cell layers. Near to the anastomosis excessive myointimal hyperplasia was detectable. Also, eight days after operation, some positive endothelial cells in adventitia were seen near to the anastomosis in small vessel lumina. Four weeks after operation, the luminal endothelium was completely regenerated and the luminal endothelial layer was confluent. Eight days after the operation regeneration in lateral regions was faster than in the region of the transplant.

CONCLUSION

In our experiment regeneration in lateral regions was faster than in the region of the transplant. Early staining in adventitia and proof of newly formed vasa vasora in adventitia may be a sign of a possible migration from adventitia to luminal area.

Potentials of ultrasound in the diagnosis of midfacial fractures*

The aim of this study was to evaluate the application and limitation of ultrasound in the diagnosis of midfacial fractures. Eighty-one patients with radiologically proved fractures of the facial skeleton were included in this study. Examinations were performed using a 7.5-MHz small-part applicator. Another ten patients without facial fractures served as controls with normal sonoanatomical findings. The most important deficiency of ultrasound in the diagnosis of midfacial fractures is the difficult detection of non-dislocated fractures. According to our own experiences, the application of ultrasound in midfacial fractures is most useful for visualization of the zygomatic arch and the anterior wall of the frontal sinus, with immediate imaging after closed reduction avoiding radiation exposure. Moreover, it is restricted to fractures of the orbital margin and nasal bone. If ultrasound is performed as the first imaging modality in cases of suspected facial fractures by an experienced investigator, the visualization of fracture lines can avoid conventional imaging, so that only an indicated CT scan can be added. In doubtful cases, an individual combination of conventional radiographs would be the next step. By this, an overall reduction of radiation exposure seems possible.

Malignant peripheral nerve sheath tumours in neurofibromatosis type 1: MRI supports the diagnosis of malignant plexiform neurofibroma

Plexiform neurofibroma (PNF) is a typical feature of neurofibromatosis 1 (NF1). About 10% of patients with NF1 develop malignant peripheral nerve-sheath tumours (MPNST), usually arising from PNF, and this is the major cause of poor survival. A better prognosis can be achieved if the tumours are diagnosed at an early stage. Our objective was to establish MRI criteria for MPNST and to test their usefulness in detecting early malignant change in PNF. MRI was performed on 50 patients with NF1 and nerve-sheath tumours, of whom seven had atypical pain, tumour growth or neurological deficits indicative of malignancy; the other 43 were asymptomatic. On MRI all seven symptomatic patients had inhomogeneous lesions, due to necrosis and haemorrhage and patchy contrast enhancement. In one patient, the multiplicity of confluent tumours with inhomogeneous areas in addition to central lesions did not allow exclusion of malignancy. Only three of the 43 asymptomatic patients had comparable changes; the other 40 patients had tumours being of relatively homogeneous structure on T1- and T2-weighted images before and after contrast enhancement. All three asymptomatic patients with inhomogeneous lesions were shown to have MPNST.

Growth type of plexiform neurofibromas in NF1 determined on magnetic resonance images

This article describes some types of growth in plexiform neurofibroma (PNF) on magnetic resonance images (MRI). This tumor is almost exclusively associated with NF1. On MRI, the tumor is depicted as a hyperintensive area on T2-weighted images. We distinguished 3 patterns of tumor growth: first, the superficial and non-invasive tumors, that are restricted to the cutis and subcutis, only eventually having outgrowth to the muscles beneath and are slow growing. Second, the displacing PNF that develop in deeper layers of the skin or within the body. They can grow to a large extent but do not invade adjacent muscles or skin. Thirdly, the invasive type with no visible margins that cannot be resected without adjacent structures or organs. A combination of these tumors can sometimes be noted, e.g. a displacing tumorous nerve developing in a large lumpy, non-invasive PNF. These categories might be used as a current guideline for medical advice, surgical treatment planning and medication trials.

Expression and distribution of basement membrane proteins in rat larynx and trachea following irradiation

OBJECTIVE

Basement membranes-(BM) influence polarization, differentiation, migration and proliferation of cell and play an important role in maintaining structural and functional tissue integrity. While BM alterations have been reported in various lesions (e.g. inflammation, tumors) of laryngeal-tracheal tissues, reports on radiogenic BM alterations are rare. External irradiation (IRR) of advanced head and neck tumors often includes "normal tissues" (tissues without cancer) of the larynx. In these normal tissues both single-cell damage (necrosis, apoptosis, functional cell death) and interstitial damage (edema, fibrosis, vascular alterations, cellular infiltrations) resulting in tissue remodeling can occur, depending on various IRR parameters. In this study, we set out to add to our knowledge on the phenotypic characterization of the radiogenic BM expression pattern in laryngo-tracheal tissues.

MATERIALS AND METHODS

In 63 laryngo-tracheal specimens from Wistar rats, we investigated the laminin (LA) and collagen IV (CIV) expression profile and distribution pattern depending on the IRR dose (fractionated IRR, 2 Gy/day, up to a total dose of 20, 40, or 60 Gy), the time since IRR (6 months vs 12 months) and animal age (1 year vs 1.5 years) using immunohistochemical methods, semiquantitative assessment, and multivariate analysis.

RESULTS

In specimens irradiated with more than 20 Gy, both BM constituents predominantly showed dose-dependent increases and sometimes fluctuations in staining at slight to moderate levels. The expression differed in frequency and level among the various tissue structures. In some structures there was decreased expression. In the vocalis muscle, laryngeal and esophageal nerve endings, recurrent laryngeal nerve and laryngeal and tracheal muscles, LA was detected at levels significantly stronger than in controls. BM surrounding gland structures, nerve endings of the piriform sinus and esophageal muscles showed a marked tendency towards increased LA expression. However, the BM underlying the mucosal layer of the supra- and subglottic region revealed decreasing LA immunoreaction up to 40 Gy IRR, but a distinct increase in expression at 60 Gy. In the esophageal and tracheal muscles, tracheal perichondrium, recurrent laryngeal nerve and capillaries, CIV was detected at significantly stronger levels than in the controls. The vocal ligament exhibited positive CIV immunoreactions adjacent to interstitial and infiltrate cells and CIV-positive BM condensations, resulting in increased staining of these structures. CIV reactions of laryngeal and hypopharyngeal nerve endings tended towards increased expression. In contrast, BM staining surrounding vocal muscle cells revealed significantly decreased expression. In addition, there was a tendency towards decreased expression for supraglottic, subglottic and hypopharyngeal muscle cells. Age and time since irradiation had no significant effect on staining.

CONCLUSION

The BM constituents laminin and collagen IV showed prominent dose-dependent increases and sometimes fluctuations in expression. This expression pattern persisted up to one year after completion of the irradiation. Thus, these findings must be related to late radiation effects. The altered BM expression may play a role, at least in part, in structural (e.g. laryngeal edema) and functional (voice disorders) changes associated with irradiation of the head and neck area.

The expression pattern of collagen I in irradiated mandibular salivary glands of rats

Irradiation damage to salivary glands leads to loss of function and fibrosis. Immunohistochemical analysis of extracellular matrix proteins might give a more precise insight into the irradiation damage of glands. Collagen I (C-I) is a major component of the extracellular space. The aim of this study was to analyse the effects of irradiation on the distribution pattern of C-I in the salivary glands of rats.

MATERIALS AND METHODS

Sixty female Wistar rats were fractionated irradiated up to 60 Gy (left side of the neck; 2 Gy/d, 5d/week; total dosage either 20, 40 or 60 Gy). The glands were explanted after 6 or 12 months following supravital anesthesia, the shielded right gland serving as internal control. C-I was detected immunohistochemically.

RESULTS

In non-irradiated animals the immunoreaction was mainly homogeneous and slight around the ductal epithelia, in the area of the capsule and septae and the peri- and epineurium of nerves. A statistically significant difference was identified in the irradiated rats vs control animals and comparing in-the-radiation field (left side) vs outside-the-radiation field (right side) situated glands. Multivariate analysis revealed a statistically significant increase in staining of irradiated rats concerning the excretory ducts, the area of the capsule and septae, the nerves and striated ducts and adventitia of vessels [p = 0.0001]. The increase of immunoreaction in irradiated glands started above 20 Gy total dosage and was at its maximum after 60 Gy. However, the expression profile was inhomogenous following 20 Gy exposure and did not differ statistically from glands of control animals. Neither the age of the animals nor the latency period following exposure to the radiation source yielded a statistically significant effect on the immunoreaction.

CONCLUSION

Studies on irradiation damage to the salivary glands require a more detailed description of the proteins accumulating in the extracellular space, thereby forming the so-called "fibrosis". These accumulations of proteins, e.g. C-I, may both support apoptosis and support a hypoxic environment giving rise to transformed cells.

Ki-67 proliferation-index (MIB-1) of neurofibromas in neurofibromatosis type 1 patients

OBJECTIVE

The aim of this study was to analyse the proliferation rate of neurofibromas, in neurofibromatosis type 1 (NF1) patients in order to find out whether tumor growth can be correlated with the different subtypes, size and localisation of tumors, or gender. Large tumors and those localisations that do not allow a complete resection, e.g. the trigeminal branch plexiform neurofibromas, often require repeated surgical interventions. Therefore, the question whether partial resection is associated with alterations of the tumor type and proliferation is of great interest.

MATERIALS AND METHODS

We investigated 317 specimens of 96 patients. Twenty-five specimens were identified as local recurrences, all of them being consecutive resections in the previously operated area. All patients were NF 1-affected individuals who fulfilled the US National Institute of Health consensus criteria for defining the disease. The proliferation index (PI) was assessed on formalin-fixed, paraffin-embedded tissue stained with the MIB- 1 antibody (Ki-67 antigen). The PI was evaluated in three high-power fields (0.1 square millimeter) in the area with the highest proliferative activity. The correlations were calculated according to Spearman-Rho.

RESULTS

Men were more often surgically treated in the head and neck than women (p < 0.02). Plexiform neurofibromas were more frequently operated on in the head and neck than in other regions (p < 0.01). Older patients were more often treated for the diffuse cutaneous type of neurofibromas (p < 0.0001). The type of tumor did not differ from primaries to recurrent tumors. The MIB- 1 PI showed no association with any of the clinical parameters. In particular, there was no difference of the MIB-1 index between primaries and recurrent tumors.

DISCUSSION

This study showed, for the first time, that proliferation in neurofibromas is not enhanced in previously partially resected neurofibromas. Hence, the argument that trauma or surgery for neurofibromas might promote proliferation, especially in the plexiform neurofibroma, is not supported by the results of the present study. Further this analysis demonstrated interdependencies between tumor type, localisation, age and gender indicative of the social difficulties encountered by the NF1 patients which may be helpful for the advising practitioner.

Molecular study of frequency of mosaicism in neurofibromatosis 2 patients with bilateral vestibular schwannomas

Neurofibromatosis 2 (NF2) is a severe autosomal dominant disorder that predisposes to multiple tumours of the nervous system. About half of all patients are founders with clinically unaffected parents. The purpose of the present study was to examine the extent to which mosaicism is present in NF2 founders. A total of 233 NF2 founders with bilateral vestibular schwannomas (BVS) were screened by exon scanning. NF2 mutations were detected in the blood samples of 122 patients (52%). In 10 of the 122 cases, the ratio of mutant to normal alleles was obviously less than 1, suggesting mosaicism. Tumour specimens were available from 35 of the 111 subjects in whom no mutation could be detected in blood specimens. Mutational analysis by exon scanning detected typical NF2 mutations in 21 of the 35 tumours. In nine subjects, the alterations found in tumours could be confirmed to be the constitutional mutation based on finding of identical mutations in pathologically and/or anatomically distinct second tumours. In six other subjects with only a single tumour available, allelic loss of the NF2 gene was found in addition to the mutation in each tumour, suggesting that either the mutation or the deletion of the NF2 gene is probably the constitutional genetic alteration. Our results suggest that failure to find constitutional mutations in blood specimen from these 15 patients was not because of the limitation of the applied screening technique, but the lack of the mutations in their leucocytes, best explained by mosaicism. Extrapolating the rate (15/35 = 43%) of mosaicism in these 35 cases to the 111 NF2 founders with no constitutional NF2 mutations found in their blood, we inferred 48 mosaic subjects (111 x 0.429). Adding the 10 mosaic cases detected directly in blood specimens, we estimate the rate of mosaicism to be 24.8% (58/233) in our cohort of 233 NF2 founders with bilateral vestibular schwannomas.

[Involvement of the maxillary sinus in Langerhans cell histiocytosis]

AIM

A clinical presentation of Langerhans cell histiocytosis (LCH) in the maxillary sinus of two patients is given. LCH in the maxillary sinus is a rare occurrence. Our aim was to compare the different treatment alternatives available and to suggest a classification as well as a therapeutic regime.

PATIENTS AND METHOD

Records and clinical data of two patients treated between 1994 and 2001 were retrospectively evaluated. Both patients suffered from LCH in the maxillary sinus and the maxilla regions. Only surgical treatment was used. After resection, a large defect of the maxillary sinus, which did not allowing coverage, was seen in both cases. After reconstructive operations, closure was finally achieved. Both patients underwent follow-ups, whereby one suffered from a relapse after 15 months.

RESULTS

Although one of the patients under investigation showed a recurrence of LCH, we are of the opinion that surgical treatment is very effective in the elimination of this condition. A proposal for a classification of LCH in the oral-maxillo-facial-region is made.

CONCLUSIONS

The evaluation of our clinical study suggests that LCH is a disease that should be treated surgically. Only in very severe cases should the surgical treatment be complimented by either radiotherapy or chemotherapy. In disseminated cases, especially chemotherapy seems to improve the outcome. Surgery offers the possibility of eliminating systemic side effects.

[Abnormalities of the maxillary sinus in type 1 neurofibromatosis]

AIM

The aim of this study was to determine the malformations of the maxillary sinus in neurofibromatosis type 1 patients (NF1).

MATERIAL AND METHODS

Twenty-two patients with NF1 were investigated clinically and radiologically: 11 had an unilateral trigeminal plexiform neurofibroma and 11 had multiple cutaneous neurofibromas. The histological type of NF was ascertained in all cases following tumor resections. The malformation of the maxillary sinus was assessed on plain radiographs and computed or magnetic resonance tomograms. Intraindividual side comparison was used to judge the size of the sinus and its position in the midface.

RESULTS

In patients with cutaneous neurofibromas the maxillary sinus appeared symmetrical in size and position. The pneumatization of the sinus had no abnormalities on the radiographs. Malformations of the maxillary sinus were restricted to plexiform neurofibromas. On the side affected by a plexiform NF, the sinus appeared hypoplastic and caudally displaced due to an enlarged ipsilateral orbit. The expansion of the sinus to the lateral side was impaired, obviously due to tumor masses. Consecutively, the alveolar process of the affected side was also displaced leading to a complex malocclusion.

DISCUSSION

Malformations of the face are frequently presented as case reports in the literature. Emphasis is given to the elephantiasis-like tumor growth of the face in certain patients with NF1. The underlying pathology has not yet been fully understood. This report provides evidence that in the midfacial region the overgrowth is predominantly caused by the plexiform neurofibroma itself and that the bones can even be hypoplastic and show scoliosis-like malformation compared to the nonaffected side. These findings are relevant when debulking procedures of the face are planned for NF1 patients.

[Experimental and histomorphologic studies of healing processes of anastomoses of the carotid artery in the Wistar rat animal model with immunohistochemical imaging of collagen IV]

INTRODUCTION

The main risk in free flap tissue transfer is posed by the microvascular anastomosis. The dangers confronting the anastomosis are thrombosis, aneurysm, and vascular insufficiency. Collagen IV is associated with the basement membrane complex. It plays an essential role in vascular tissue organization and supports mechanical properties of vessels. We used a long-term animal experiment to gain a new understanding of histomorphological apposition of anastomosis and distribution of collagen IV.

METHODS

Seventy Wistar rats, seven groups of ten animals each, were operated. A 4-mm long segment of the common carotid artery was isolated and reinserted. After a varying length of time (between directly after the operation and 6 months later), the common carotid arteries including bifurcation were isolated after cardiovascular perfusion. Carotid arteries were embedded, and cross-sections were stained with hematoxylin and eosin, Verhoeff's tissue elastin stain, and immunohistochemical anti-collagen IV antibody. By using the above-described technique in each section four anastomoses were examined. The histomorphology and intensity of the anti-collagen IV stainings were evaluated.

RESULTS

Compression, shift, and dehiscence as forms of vessel apposition were often seen. We observed an overexpression of collagen IV in the media in cases of compression and shift. The grade of expression of collagen IV in the anastomosis depends on the extent of the injury.

CONCLUSIONS

A well-performed microvascular anastomosis is clinically important not only for the acute phase after the operation, but also for the long-term course. The application of antibodies to identify the collagen IV distribution is valuable for studying vascular healing. Further applications could be used in follow-up studies of vascular prostheses.

Limitations of B-scan ultrasound for diagnosing fractures of the mandibular condyle and ramus

The aim of this study was to analyse the applications and limitations of B-scan ultrasonography for diagnosing fractures of the mandibular condyle and ramus. Thirty-two patients with 39 radiologically proven fractures of the mandibular condyle and ramus were included in the study. The patients were examined with a 7.5 MHz small-part applicator. Five patients without fractures of the facial skeleton acted as controls. Normal sonoanatomical findings had been obtained for patients without mandibular fractures. B-scan ultrasonography enabled the experienced examiner to identify dislocated fractures of the mandibular ramus and the articular process in 67% of the fractures. The main disadvantage of ultrasonography was the inability of this technique to identify non-dislocated fractures. Because of its low sensitivity and specificity, B-scan ultrasonography does not provide an alternative to X-ray diagnosis of mandibular condyle and ramus fractures.

[Acute temporomandibular joint arthritis after Lyme borreliosis]

CASE REPORT

This report is about a rare connection between Lyme disease and an inflammation of the left temporomandibular joint. In this case, an infection was documented in 1998, 5 years after contact with Borrelia burgdorferi. The patient, a 49-year-old female, first came to our department in 1999. She showed the symptoms of a left temporomandibular joint infection.

THERAPY

We suggested treatment with ceftriaxone 1 x 2 g/day i.v.

[Immunohistochemical detection of hormones in hypophyseal adenomas of the rat after fractionated irradiation]

BACKGROUND

The aim of this study was to determine the hormones produced in pituitary gland tumours (TM) following fractionated external irradiation in rats. The TM arose in the course of studies on other questions of radiation effects.

METHODS

The left neck and skull base of sixty female Wistar rats, 3 to 4 months of age at the beginning of the external irradiation, were subjected to roentgen rays exposure, fractionated to 2 Grays daily, either up to 20, 40 or 60 Gy. The midline of the neck and skull was always inside the radiation field. The animals were sacrificed either 6 months or 12 months after completion of the randomly assigned irradiation protocol. Five non-irradiated rats served as controls.

RESULTS

No TM developed in the non-irradiated animals. Out of 60 irradiated rats 9 developed a pituitary TM (15%). In remnants of the normal adenohypophysis we revealed immunohistochemical reactivity for growth hormone (GH), adrenocorticotropic hormone (ACTH), prolactin (PRL), thyroid stimulating hormone (TSH), and follicle stimulating hormone (FSH). In the radiation-induced adenomas, 4 TM were immuno-reactive for TSH, 4 for GH, 2 for PRL, and 2 for FSH. The TM did not react with anti-ACTH and anti-LH (luteinizing hormone) anti-sera.

CONCLUSIONS

Obviously, irradiation accelerates the development of pituitary gland adenomas. In this series the TM were predominantly incidental findings at necropsies after pretermed follow-up intervals with a variety of hormone-producing cells. On the other hand, four of nine TM were null adenomas. Necropsies of the brain should be carried out routinely in irradiation studies of the skull.

[Pneumatization of the zygomatic arch on pantomography]

BACKGROUND

The pneumatized spaces of the zygomatic arch (zygomatic air cell defect) are a clinically asymptomatic variation of the temporal bone. The empty spaces of the articular eminence and temporal bone of the zygomatic arch are depicted on radiographs as a sharply demarcated osteolytic lesion of round or oval shape. The aim of this study was to determine the prevalence and characteristics of the ZACD in our outpatients.

MATERIALS AND METHODS

We investigated the panoramic radiographs of 1,084 patients who were treated during 1 February and 31 July 2000. The mean age of the 1,084 patients was 41.9 years (SD: 17.2 years; range: 2-96): 628 patients were male (58%) and 456 female (42%). A ZACD was found in 20 of 1,084 patients (prevalence: 1.85%). The mean age of the patients with a ZACD was 43.2 years (SD: 18.4 years; range: 7-87): 11 were female (55%) and 9 male (45%).

RESULTS

A bilateral ZACD was found in 20% (four patients). Interestingly, one of these ZACD patients was a 7-year-old boy. Up to now, it had generally been accepted that pneumatization of the zygomatic arch takes place after puberty with the youngest persons with ZACD being 15 years of age. Our findings should prompt consecutive studies on the prevalence of ZACD in children. This finding can be relevant in patients treated for spreading otitis media or mastoiditis.

[Detection of p53 mutation in mouth mucosa smears of patients with oral squamous epithelial carcinoma]

Tumour-suppressor gene p53 encodes for an important cell-cycle regulatory protein and is therefore probably important for the development of many malignant diseases, e.g. squamous cell carcinoma of the mouth. This gene has mutated most frequently in connection with the development of cancer, so it has been well explored. Hence we chose it to find out whether swabs of the oral mucosa are suitable for supplying material for the detection of mutations in a gene that is connected with the development of oral squamous cell carcinomas, because swabs are easier to obtain than biopsies. We examined biopsies, swabs from the tumour, and swabs from mucosa that appeared healthy from 32 patients with oral squamous cell carcinoma and mucosal swabs from 35 healthy persons with polymerase chain reaction (PCR) and temperature gradient gel electrophoresis (TGGE). Fourteen of the 32 patients with a tumour showed mutations of p53, and in all cases the mutation could be demonstrated both in the biopsy and in the tumour swab. In four cases the mutation was also found in the swab of normal mucosa. Our investigations revealed that swabs are a suitable method for obtaining material for the detection of gene mutations in oral squamous cell carcinomas.

P53-mutation in smears of oral squamous cell carcinoma

The tumor suppressor gene p53 encodes for an important cell cycle regulatory protein. Loss of the protein's function is probably important for the development of a variety of malignant diseases, including oral cancer. Up to present knowledge, the mutations of the p53 gene are one of the most frequent genetic alterations detectable in human cancer. The aim of this study was to explore the capability of molecular diagnostics to identify p53 mutations (exon 5-8) in smears of the oral mucosa (polymerase chain reaction, temperature gradient gel electrophoresis). Thirty two patients with oral squamous cell carcinoma comprised the study. Biopsies of the tumor, smears of the ulcer, and smears of apparently healthy mucosa were collected from these cancer patients. Smears of 35 healthy volunteers served as controls. P53-mutations were detected in 14 of the 32 cancer patients (44%). The same mutations was also detected in the biopsy in all cases. In addition, swabs of apparently normal mucosa harboured p53-mutated cells in 4 of these 14 patients. No mutation was found in healthy volunteers. Our investigation showed the suitability of swabs for gaining sufficient material to detect p53 gene mutations in oral squamous cell carcinoma.