Comprehensive genomic analysis identifiesMDM2 andAURKA as novel amplified genes in juvenile angiofibromas

BACKGROUND

Frequent beta-catenin mutations have been detected in juvenile angiofibromas, but the tumor pathogenesis remains unknown.

METHODS

Metaphase-comparative genomic hybridization (CGH) was used to identify chromosomal aberrations in 29 tumor specimens. Two tumors were investigated using genome DNA microarrays.

RESULTS

Three hundred eleven chromosomal gains and losses were detected by metaphase-CGH. Frequent chromosomal gains were detected at 4q, 6, 12, and X, while frequent chromosomal losses affected regions of chromosomes 8, 16, 17, 22, and Y. Genome DNA microarray analysis in 2 tumors of the series confirmed chromosomal aberrations, detected by metaphase-CGH, and indicated genes such as AURKA (20q13.2) not being recognized by metaphase-CGH.

CONCLUSION

Metaphase-CGH results confirmed numerous chromosomal aberrations in juvenile angiofibromas. The most frequent aberrations affected sex chromosomes. Further consensus regions of chromosomal aberrations were detected at 4q, 6, 8, 12, 16, 17, and 22. AURKA and MDM2 were identified as interesting novel amplified genes in juvenile angiofibromas.

[Temporary sensory hearing deficits after ear surgery--a retrospective analysis]

BACKGROUND

Temporary and persistent threshold shifts can occur after ear surgery. So far, only few studies deal with temporary sensory hearing deficits after ear surgery.

PATIENTS AND METHODS

In a retrospective study, thresholds at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz were analysed in 393 patients (125 x mesotympanal chronic otitis media, 164 x cholesteatoma, 44 x tympanosclerosis, 60 x otosclerosis) before, the first 4 days and 3 weeks after ear surgery to evaluate possible temporary threshold shifts.

RESULTS

Analysis of all patients in total proved statistically significant slight temporary threshold shifts of up to 7 dB at 2000 Hz (postoperative day 1 to 3) and at 4000 Hz (postoperative day 1 and 2). Use of a drill caused a statistically slight temporary threshold shift only at 2000 Hz at the first postoperative day (4.2 dB). In cholesteatoma surgery with preparations at the ossicular chain a statistically significant slightly higher threshold level was found in all postsurgical evaluations at 500 Hz. Removal of scars or granulation tissue attached to the ossicular chain was not associated with an elevation of threshold levels.

CONCLUSION

Slight temporary threshold shifts can be observed at 2000 Hz and 4000 Hz after ear surgery. Use of the drill and preparation at the ossicular chain usually results in no significant sensory hearing deficit.

Clinical outcome of partial ethmoidectomy for chronic rhinosinusitis

Since its introduction endoscopic sinus surgery (ESS) for the treatment of chronic rhinosinusitis (CRS) has been focused on the management of the ethmoids, differentiating between partial and total ethmoidectomy. The classification of the underlying process of ethmoiditis and the selection of the adequate surgical procedure are still open questions. The aim of this investigation was to evaluate a minimally invasive ESS procedure. We present a retrospective analysis of 112 cases of bilateral circumscribed ethmoiditis after partial ethmoidectomy performed by a single surgeon investigated by questionnaires and endoscopic follow-up. A comparison of symptoms and the subjective judgment of the patients before and after surgery showed that postoperative subjective scores of nasal obstruction and rhinorrhea improved in up to 90%, with no distinct differences between primary intervention (n=98) and revision (n=14). Ninety percent of all patients considered surgery successful. Signs of active rhinosinusitis were found in less then 20% of patients after partial ethmoidectomy. This demonstrates that partial ethmoidectomy is an effective treatment for CRS affecting only part of the ethmoid.

Genetic heterogeneity of the MYC oncogene in advanced juvenile angiofibromas

Despite their benign histological appearance, juvenile angiofibromas sometimes exhibit an aggressive growth behavior. Molecular and genetic analyses have detected beta-catenin mutations and androgen receptor gene gains in this tumor. Because intensive cross-talk among beta-catenin, androgen receptor, and C-MYC has been detected recently, we analyzed expression of the C-MYC protooncogene (MYC) on the genetic, transcriptional and translational level in seven sporadic juvenile angiofibromas. Two-color in situ hybridization analyses for chromosome 8 and MYC found in all seven juvenile angiofibromas significant MYC losses. In the three advanced juvenile angiofibromas of this series (Fisch stages III and IV) additional significant MYC gains were observed demonstrating a genetic heterogeneity for the MYC protooncogene. In cases of genetic MYC heterogeneity, reverse transcriptase-polymerase chain reaction (RT-PCR) analysis, Western blot investigations, and immunohistology showed increased C-MYC mRNA and protein levels. Semiquantitative RT-PCR analyses from laser microdissected endothelial cells and fibroblasts found no differences of C-MYC mRNA levels, leaving open the question of the neoplastic cell in juvenile angiofibromas. The finding of genetic MYC heterogeneity associated with C-MYC overexpression on the mRNA and protein level in advanced juvenile angiofibromas indicates involvement of the MYC oncogene in aggressive growth behavior.

Endonasal approach for frontobasal malignant nerve sheath tumor: a case report

Malignant peripheral nerve sheath tumors (MPNST) are rarely encountered in the paranasal sinuses and frontal skull base. We present histopathological findings, cytometric DNA measurements, and the preliminary results of comparative genomic hybridization analysis of a 46-year-old male patient with a frontobasal MPNST. The tumor was resected via the endonasal approach. No tumor recurrence was detected during a follow-up of three years. Rhinologists are being more frequently involved in endonasal tumor resection.

Das Styloidsyndrom und seine Behandlung

BACKGROUND

An elongation of the styloid process or an ossification of the stylohyoid ligament can be the cause for a styloid syndrome and may lead to craniocervical pain, globus sensation and dysphagia. Pathophysiologically, the styloid syndrome is related to an irritation of the surrounding nerves, the carotid artery or the pharyngeal mucosa. There are various alternatives for its treatment.

PATIENTS AND METHODS

This study analyzed retrospectively the data of eleven patients, who were treated for a styloid syndrome. All patients were placed on a stepwise therapy plan, which began with a medicamentous treatment, followed by a surgical treatment, if the problems persisted. The surgical approach included a transoral styloid fracture and/ or a surgical styloid shortening, which was carried out either transorally or transcervically.

RESULTS

Three of the eleven patients presented no complaints after the medical treatment and did not require any further therapy. In two out of five patients, transoral fracturing of the styloid was successful. Six patients underwent surgical resection of the styloid process. In five cases a transoral route was used and in one cases a transcervical route. Postoperatively, four patients were free of symptoms and did not present any functional deficit. Two patients experienced severe complications with an ipsilateral medial cerebral artery infarction. These were related to a dissection of the internal carotid artery (ICA) in one case, and an arrosion bleeding of the ICA after the formation of an abscess of the parapharyngeal space in the other case.

CONCLUSION

A stepwise therapy of the styloid syndrome including medicamentous treatment, transoral styloid fracture and resection of the styloid process has proven to be of value. If the styloid process can be palpated submucosally, a transoral resection may be chosen. However, using this route, the possibility of severe complications has to be taken into consideration, such as injury of the internal carotid artery.

p53 and Her-2/neu in juvenile angiofibromas

The pathogenesis of juvenile angiofibroma (JA) remains unsolved. Further, it is unknown whether this fibrovascular tumour arises from the endothelial or stromal cells. Comparative genomic hybridisation analysis of these tumours revealed deletions of chromosome 17, including regions for the tumour suppressor gene p53 as well as the Her-2/neu oncogene, which are altered in many human tumours. In order to analyse if they are also important for progression of JA, the p53 gene and Her-2/neu gene were evaluated in 7 tumours by two-colour in situ hybridisation analysis using probes for the centromer of chromosome 17 either with a specific probe against p53 or Her-2/neu. In 5 out of 7 JAs, gene losses were detected for both genes ranging from 10.5 to 31.5%, respectively. Gene amplifications were not observed. Semi-quantitative RT-PCR analysis from laser microdissected single endothelial cells and fibroblasts showed up-regulated p53 mRNA levels in 4 out of the 7 JAs analysed in both investigated cell types and in one case in only endothelial cells. Her-2/neu mRNA was noted to be up-regulated in 2 JAs and down-regulated in 1 JA for both cell types. Western blot analysis as well as immunohistochemistry detected no p53 protein in the 5 investigated JAs, indicating absence of mutated p53. Our findings indicate that chromosomal losses on chromosome 17 imply p53 gene and Her-2/neu gene losses in JAs. However, comparison of p53 and Her-2/neu mRNA levels in laser microdissected endothelial and stromal cells were not conclusive to answer the question of the tumour cell of origin in JA.

[Individual silicon applicator for nasopharyngeal brachytherapy]

BACKGROUND

Beyond surgery, conventional radiation therapy, and chemotherapy brachytherapy may enrich treatment of primary, residual, or recurrent head and neck cancer. Nasopharyngeal cancer is a proper indication for intracavitary brachytherapy which can be performed using a commercial applicator system or an individual applicator.

METHODS AND PATIENTS

Technique for manufacturing an individual nasopharyngeal silicon applicator and its experiences in 3 patients (2 times brachytherapy in treatment regime of primary nasopharyngeal cancer, 1 time for nasopharyngeal lymphoma treatment) are presented.

RESULTS

Under general anaesthesia in all 3 patients nasopharyngeal imprinting after placement of two suction tubes was performed with shore 12 silicon and followed by manufacturing the individual silicon applicator with two included tubes after plaster cast of the imprinting form has been performed. This silicon applicator enabled safe endocavitary brachytherapy using the high-dose-rate-afterloading-method. Tumor control was achieved in all 3 patients.

CONCLUSIONS

The presented individual silicon applicator is suited for intracavitary brachytherapy of the nasopharynx being an valuable contribution in the primary treatment regime of nasopharyngeal cancer.

Endoscopic sinus surgery: its subjective medium-term outcome in chronic rhinosinusitis

OBJECTIVE

The subjective success of endoscopic sinus surgery (ESS) for chronic rhinosinusitis has been reported mainly after short-term follow-up studies, but may change with increasing time after surgery. We assessed in a retrospective study the medium-term clinical outcome of ESS as complete ethmoidectomy or pansinus surgery in 208 patients with chronic rhinosinusitis.

PATIENTS AND METHODS

The senior author performed the surgeries according to his techniques. We used a questionnaire focusing on nasal obstruction, rhinorrhea, nasal dryness/crusts, sneezing, headache, smell, numbness in cheeks and lips, ear pressure, epiphora, and sore throat. Additionally the subjective influence of sinus surgery on asthma, bronchitis and allergic diseases was evaluated. The mean follow-up was 3.1 years.

RESULTS

Overall success was reported by 92% of all patients. Forty-one percent of all patients with complete ethmoidectomy and 32% of all patients with pansinus surgery described complete resolution of complaints. No differences in clinical success rates were noted when comparing primary surgery or revision. A favorable effect was also reported for asthma, bronchitis and allergic diseases.

CONCLUSION

Improvements for nasal symptoms and coexisting complaints are demonstrated with a mean observation period of more than 3 years. The value of ESS is underlinedfor the treatment of patients with chronic rhinosinusitis.

[Cell transplantation for a CSF-fistula. Experience with fibrin glue and fibroblasts]

BACKGROUND

In the present study we investigated the culturing of fibroblasts on fibrin glue embedded suture nets, to analyse the possibility of using these components in a suture application technique for the closure of a CSF-fistula.

RESULTS

Placement of centrally perforated dura pieces on fibrin glue coated surfaces resulted in cellular migration from the dura borders into the defect, resulting in a complete cellular closure of the perforation. Inversion microscopic follow-up during culturing and the Alamar blue-essay found strong growth stimulation for oral mucosa fibroblasts on fibrin glue coated surfaces by insulin and FGF. Three-dimensional fibroblast growth was observed along the suture lines in the presence of fibrin glue.

CONCLUSIONS

Fibrin glue is an attractive extracellular matrix for cellular migration from the dura which is suited to fibroblast culturing in suture nets. Our findings support the idea of achieving closure of cerebrospinal fluid fistulas by suture application of autologous fibroblasts and fibrin/thrombin preparations as a realistic future goal.

Increased noise sensitivity and altered inner ear MENA distribution in VASP-/- mice

Vasodilator-stimulated phosphoprotein (VASP) and mammalian-enabled protein (MENA) share similar cellular localisation and functions (signal transduction pathways, regulation of actin cytoskeleton dynamics). Functional substitution and compensation among Ena/VASP proteins have been proposed as the reason for the absence of major morphological and functional deficits in VASP-/- mice. The aim of this study was to investigate VASP expression in the mouse cochlea, to analyse cochlear function in VASP-/- mice compared with wildtype mice, and to analyse cochlear MENA distribution taking into account that MENA protein might compensate VASP loss in the cochlea of VASP-/- mice. We confirmed specific VASP expression in the pillar cells of the mice organ of Corti as previously reported for rat cochlea. By analysing the hearing function in VASP-/- mice, we found no differences in auditory brainstem responses and distortion product otoacoustic emissions from those of wildtype mice but evidence for an increased noise sensitivity at lower frequencies. When MENA protein levels in cochlea tissue were tested in mutant and wildtype mice by Western blot analysis, no significant differences were found, as was also seen with regard to MENA mRNA levels in laser-microdissected single pillar cells. Most surprisingly, however, MENA protein was absent in pillar cells of VASP-/- mice, whereas it was detected in other cochlear cells. The finding of a cell-specific, and not organ-specific, redundancy of MENA protein expression noted for the first time in VASP-/- mice is proposed as the reason for the observed distinct cochlear phenotype.

New aspects of pathogenesis of juvenile angiofibroma

For over 150 years the aetiology of juvenile angiofibroma has been addressed in numerous theories, but actual details remained unknown. Interesting new findings, reviewed here, are beginning to elucidate the aetiology of this fascinating tumour.

Chromosomale Alterationen beim juvenilen Angiofibrom

INTRODUCTION

Despite their benign histological appearance, juvenile angiofibromas, which occur mainly in adolescent males, have a locally aggressive growth pattern. beta-catenin-mutations represent their only known genetic abnormality.

MATERIAL AND METHODS

Angiofibroma tissue from seven patients was available for comparative genomic hybridization (CGH).

RESULTS

In six out of the seven angiofibromas, CGH detected various abnormalities on 18 different chromosomes. Frequent chromosomal gains were observed on chromosomes 4q, 6q, and 8q. In four out of seven angiofibromas a complete loss of the chromosome Y was detected.

CONCLUSIONS

CGH is a suitable method for the examination of angiofibromas for genetic alterations. Considering the sex distribution of this neoplasm, the frequent loss of chromosome Y is of particular interest.

Dural cell culture. A new approach to study duraplasty

Fistulas of the cerebrospinal fluid are often repaired by insertion of grafts of various kinds. However, current knowledge of wound healing after graft insertion is limited, and only a few animal studies are available. The objective of this study is to test whether an in vitro model is suited to analyze cellular healing aspects after duraplasty and to assess dura substitutes in such conditions in regard to their surface attractiveness for cellular migration from the dura margins. Harvested dura pieces from minipigs were perforated to mimic central dura lesions, placed on various coated surfaces (collagen, laminin, poly-L-lysine) or grafts, and investigated in a cell culture for cellular closure of the perforation. Cellular migration from the dura into the central perforation was noted on collagen-coated surfaces and when defects were filled with collagen gels, but there was no cell growth on surfaces with poly-L-lysine or laminin coating. Immunocytochemistry identified the migrating cells mainly as fibroblasts with some intermingled epithelial cells. Scanning electron microscopy proved cellular closure of defects after dura placement on allogenic non-crosslinked collagen transplants. Less cellular migration was observed on poly-P-dioxanon sheets, while no cells migrated into the central dura perforation after placement on a cartilage substitute. Cell counting indicated enhanced cellular closure of the dura opening after introduction of insulin or fibroblast growth factor (sign test for both: 0.031). Our study succeeded in establishing a cell culture model for duraplasty and indicated cellular migration from the dura borders at the site of the defect during the wound healing process. The cell culture model presented in this report shows that collagen grafts are best suited for duraplasty. In accordance with the immunocytological finding of fibroblast migration from the dura borders additional application of fibroblast-stimulating growth factors accelerated cellular defect closure.

A case of nasal leiomyosarcoma: the first comparative genomic hybridization analysis

Leiomyosarcomas are rare in the head and neck region. The treatment of choice is surgical resection. We present a case of leiomyosarcoma in a 50-year-old female patient, arising from the inferior turbinate. The tumor was resected by a transnasal microendoscopic approach and no evidence for tumor recurrence was found during an endoscopic and radiologic follow-up of two years. Cytogenetic analysis by means of comparative genomic hybridization revealed chromosomal gains at 4p13p15, 6p21p22, 7q22qter, 9q22qter and chromosomal losses at 10q22qter and 19p12p13.1. With augmented experience, the transnasal approach may be appropriate to resect circumscribed malignant tumors located in the nasal cavity.

Two occult skull base malformations causing recurrent meningitis in a child: a case report

Occult malformations of the skull base are rare anomalies, but can cause severe complications such as meningitis. Detailed skull base investigations for detecting cerebrospinal fluid fistulas or celes are often not initiated until after a history of recurrent meningitis. We present a child first seen at the age of 12 with recurrent episodes of bacterial meningitis since early childhood, requiring antibiotic prophylaxis for years. High-resolution computed tomography revealed a chronic sinusitis and a bony defect on the right olfactory groove, while magnetic resonance imaging and CT-cisternography indicated no cerebrospinal fluid fistula or cele at that time. Endonasal surgery for chronic sinusitis was performed with a confirmed bony defect on the right olfactory groove and an olfactory fibre without its sleeve-like dura prolongation running into an adjacent ethmoidal cell, necessitating that it be covered. In the absence of any antibiotics a new episode of meningitis occurred 5 years after surgery. CT-cisternography and magnetic resonance imaging were repeated, now indicating a transclival bony defect with a meningocele in its proximal part, most probably presenting a canalis basilaris medianus. Endonasal surgery confirmed this bony defect after adenoidectomy, and closure was accomplished. No further meningitis has been observed for 2 years. Congenital skull base defects may be difficult to detect, but sufficient surgical closure after their precise delineation is mandatory to prevent infectious endocranial complications. The presence of more than one developmental skull base defect should be considered during careful radiological skull base evaluation, which has to include the clivus in order not to overlook rare basilar malformations.

Numerical sex chromosome aberrations in juvenile angiofibromas: genetic evidence for an androgen-dependent tumor?

Juvenile angiofibromas (JAs) are rare benign tumors arising almost exclusively in the posterior nasal cavity of adolescent males. While male sex predominance and tumor manifestation during adolescence are well known clinical features, their genetic causes are still unknown. Observation of an increased androgen binding rate to the cytosol of JAs and immunohistological finding of strong AR expression have suggested involvement of the androgen receptor (AR) in JA biology. In the present study, we investigated sex chromosome distribution and the expression of the AR gene in JAs of 7 males using two-color in situ hybridizations. Probes specific for the centromeres of chromosomes 1, X, and Y as well as a probe specific for the AR gene were used for investigation of paraffin-embedded JA tissue. Significant aberrations of the chromosome 1 were not observed. In 6 out of 7 analysed JAs derived from male patients we observed a significant loss of the chromosome Y in 11.5 to 63.8% (mean value: 31.3%). A gain of chromosome X was seen in 5 out of 7 JAs with the finding of two chromosomes X in 12 to 34% (mean value: 25%) of the analyzed nuclei. As each chromosome X revealed nearly almost one AR gene signal without evidence for amplifications, in 11.5 to 30% of the JA nuclei (mean value: 23.8%) two copies of the AR gene were observed. Our data indicate a significant loss of chromosome Y in combination with a gain of chromosome X in JAs. A gain of chromosome X leads to AR gene gain indicating that JAs are androgen-dependent tumors. This is supported by the finding that beta-catenin known to be overexpressed in JAs acts as a co-activator of the AR.

[Malignant transformation of a tubular adenoma in the paranasal sinuses?]

BACKGROUND

Whereas a tubular adenoma is a unique finding within the paranasal sinuses, intestinal adenocarcinomas are especially in patients with long-term exposure to wood dust, common tumours in this location.

CASE

In a 65 year old joiner endonasal sinus surgery performed to treat suspected chronic pansinusitis brought up by chance the histological finding of a tubular adenoma. As the patient at first refused surgical revision, but magnetic resonance imaging during follow-up revealed evidence for a space occupying lesion affecting the ethmoid and sphenoid sinuses revision surgery took place one year later. Histopathological evaluation now found a papillary adenocarcinoma. Clinical follow-up and magnetic resonance imaging one year after second surgery found no evidence for tumour recurrence.

CONCLUSIONS

Progression of a tubular adenoma to an adenocarcinoma like in the adenoma-carcinoma model well known for colorectal carcinomas has so far not been observed within the paranasal sinuses. But, an adenocarcinoma already present at the time of first surgery can not be ruled out completely in the presented case as histopathological evaluation may have failed to detect an adenocarcinoma in the available specimens after first surgery. Either malignant transformation of a tubular adenoma had occurred or proof of an adenocarcinoma has failed with misdiagnosis of a tubular adenoma. A tubular adenoma as well as an adenocarcinoma require complete resection and careful clinical and radiological follow-up to avoid adenocarcinoma development from a tubular adenoma or to detect an adenocarcinoma by histological evaluation of the whole specimen.

[Expression of members of the cadherin-/catenin-protein family in juvenile angiofibromas]

BACKGROUND

Angiofibromas are benign, but locally aggressive tumors occurring nearly exclusively in adolescent males. Pathogenesis of this fibrovascular neoplasm is still unknown. Detection of beta-catenin gene mutations and immunohistochemical localization of beta-catenin only in the nuclei of stromal cells has been proposed as evidence for the stromal cells to be the neoplastic cells in angiofibromas (Abraham et al., 2001).

METHODS

Paraffin embedded tissue of 13 angiofibromas was analysed immunohistochemically for expression of E-cadherin, N-cadherin, alpha-catenin, beta-catenin and gamma-catenin.

RESULTS

In all angiofibromas stromal cells showed in their cytoplasm and their nuclei strong immunoreaction for beta-catenin. In 10 out of 13 angiofibromas strong immunoreaction was also observed in endothelial cells covering the irregular lined vascular spaces. While gamma-catenin was detected in 7 out of 13 angiofibromas in the stromal cells and endothelial cells, N-cadherin was found only in the stromal cells in 8 out of 13 angiofibromas. No significant immunoreaction in angiofibromas was seen for E-cadherin and alpha-catenin.

CONCLUSIONS

Proof of strong beta-catenin-expression in stromal cells and endothelial cells stress possible importance of the APC/beta-catenin-pathway in angiofibromas, but gives no certain evidence for the assumption that stromal cells may be the neoplastic cells. As beta-catenin can increase sensitivity of the androgen receptor, it may be assumed that the increased beta-catenin-expression in angiofibromas is involved in the typical growth stimulus of this tumor in adolescent males.

Postoperative magnetic resonance imaging findings after transtemporal and translabyrinthine vestibular schwannoma resection

OBJECTIVES/HYPOTHESIS

Magnetic resonance imaging (MRI) has become the investigation of choice to follow up patients after vestibular schwannoma resection.

STUDY DESIGN

Retrospective.

METHODS

Postoperative MRI findings of 70 patients after vestibular schwannoma resection through a transtemporal (n = 48) and a translabyrinthine (n = 22) approach were reviewed. Time-dependent changes in intensity, size, and shape of enhancement in the internal auditory canal before and after contrast administration, postoperative temporal lobe gliosis, and changes of fat grafts were evaluated.

RESULTS

After vestibular schwannoma resection, all patients showed signal enhancements in the internal auditory canal ranging from a faint to high signal intensity in the first postoperative MRI, 3 to 6 months after surgery. In the next MRI at 12 to 24 months after surgery, 30 patients (43%) showed a decreased signal, 35 patients (50%) a stable enhancement, and 5 patients (7%) an increased enhancement in the internal auditory canal depicted as an intense nodular or mass-like pattern. In patients with decreased or stable enhancement, a residual tumor could be excluded in the following MRI scans, whereas in all patients with increased enhancements after 12 to 24 months, signal enhancement further increased and residual tumors were detected. Different degrees of temporal lobe gliosis were found in 15 of 48 cases (31%) after transtemporal tumor removal. Enhancement of fat grafts used in 22 cases decreased to different degrees in 14 cases (64%).

CONCLUSIONS

Differentiation of residual tumor from scar tissue in the internal auditory canal after vestibular schwannoma resection requires close, long-term follow-up. Nodular and progressive enhancements in the internal auditory canal indicate residual tumor. Linear enhancement in the internal auditory canal has been found to be a common finding after vestibular schwannoma resection not associated with residual tumor.

Expression of VASP and zyxin in cochlear pillar cells: indication for actin-based dynamics?

Vasodilator-stimulated phosphoprotein (VASP) is a member of the ENA/VASP-protein family. VASP is considered to be a crucial factor in the regulation of actin dynamics, which involves processes such as motility and cell adhesion, e.g. in filopodia or growth cones. In these processes zyxin acts as an important partner of VASP and is particularly concentrated at sites where VASP-dependent actin dynamics occur. Based on indirect evidence that actin-mediated dynamics may effect the mechanical properties of the cochlea, we have investigated expression of VASP and zyxin in the postnatal and adult rat cochlea using polymerase chain reaction and Western blot approaches, as well as immunohistochemistry and confocal microscopy. Besides an expected expression in vessels and fibroblasts, VASP and zyxin expression was also observed in pillar cells. Here, the staining was restricted to the head and foot plate of the pillar cells. Onset of VASP expression in pillar cells coincided with the beginning of hearing. In pillar cells, VASP and zyxin were co-localised with pan-actin, suggesting actin-based dynamics in these cochlear cells, which until now were rather presumed to form a highly rigid bridge between the inner and outer sensory cells. Thus, pillar cells may be more dynamically involved in controlling longer-lasting mechanical properties of the cochlea as hitherto presumed.

[Life-threatening displacement of a tracheostomy tube in a patient with severe angiotensin-converting enzyme inhibitor-induced angioedema]

Angioedema of the lips and the tongue with pharyngeal and laryngeal involvement caused by angiotensin-converting enzyme inhibitors (ACEI) is rare but can cause severe airway compromise and even death due to suffocation. We present the case of a 83-year-old woman with a life-threatening displacement of a tracheostomy tube followed by tension pneumothorax after initial successful treatment of such an airway obstruction by emergency tracheostomy. This case highlights the hazards of tracheostomy tube displacement and is a reminder that where concern of tube dislodgement exists and especially when the possibility of orotracheal intubation is lacking due to upper airway obstruction or difficult airway, permanent epithelized tracheostomy should be performed early to ensure safe and fast tube replacement at any time.

MR cisternography after intrathecal Gd-DTPA application

The purpose of this study was to establish and to evaluate MR cisternography after intrathecal Gd-DTPA administration to detect rhinobasal cerebrospinal fluid (CSF) fistulae in patients with suspected CSF rhinorrhoea. Ten patients with suspected CSF rhinorrhoea were examined. The MR cisternography included the following investigation steps: acquisition of nonenhanced fat-suppressed T1-weighted spin-echo (SE) scans of the skull base and the paranasal sinuses, lumbar puncture with administration of 1 ml Gd-DTPA solute with 4 ml NaCl and performance of MR cisternography with the same fat-suppressed T1-weighted sequences as used initially. In 10 patients with suspected CSF rhinorrhoea Gd-DTPA enhanced MR cisternography detected 5 CSF fistulae. In 3 of 5 CSF leaks were located in the cribriform plate and in 2 of 5 sphenoidal. Whereas 4 of these depicted leaks were confirmed surgically, in 1 case the CSF fistula closed spontaneously. In another case, CSF leakage after severe head injury was clinically highly suspected but ceased prior to MR cisternography with inability to detect the temporary fistula. In the remaining 4 patients with serous rhinorrhoea MR cisternography did not provide any evidences for CSF fistulae. Intrathecal Gd-DTPA injection was tolerated excellently. Clinical and EEG examinations showed no gross behavioural or neurological disturbances and no seizure activity, respectively. The MR cisternography after intrathecal administration of Gd-DTPA represents a safe, promising and minimally invasive method for detection of CSF fistulae. This MR investigation provides excellent depiction of CSF spaces and pinpoints CSF fistulae.

A novel vestibular approach for gene transfer into the inner ear

The aim of gene transfer to the cochlea and vestibular organ is to protect the inner ear from different disorders. Although various vectors for gene delivery have been used with some success, there remains a need for a reliable transfer of genes into the inner ear without damaging cochlear function. Here, we have tested a novel application method for gene transfer into the rat inner ear in vivo using herpes simplex virus type-1(HSV-1)-based amplicon vectors. Our goal was to find an entry route into the inner ear that leaves its function intact. Besides other non-invasive and invasive application techniques, we applied the viral vector via injection through a small opening of the utriculus. Using this method, efficient -galactosidase reporter gene expression was achieved in nearly all neurons in the vestibulum and cochlea, without functional hearing deficits. At the time point of maximal expression 5 days after injection, -galactosidase activity was also observed in axonal fibres and synaptic endings close to inner and outer hair cells. Our results thus describe an efficient and reliable protocol for short-term expression of potential therapeutic genes in the neuronal compartment of the inner ear.

Laryngeal prostatic cancer metastases: an underestimated route of metastases?

OBJECTIVE

Despite the high rate of metastases in advanced prostatic cancer, only 12 reports with 13 cases of laryngeal metastases in prostatic cancer have been given in the literature since the first description by Schmorl in 1908. A histopathological study was undertaken to clarify the obvious controversial clinical experience of multiple metastases in prostatic cancer but rare observations of laryngeal involvement.

STUDY DESIGN

Postmortem laryngeal examination in advanced prostatic cancer.

METHODS

Six patients with prostatic cancer and tumor spread to different organs but without clinical symptoms of laryngeal involvement were available for postmortem analysis. Gross anatomical inspection of the inner and outer surfaces of the removed larynx, horizontal slices of the larynx, and subsequent histological investigations including immunohistochemical analysis were used to search for metastases.

RESULTS

Macroscopic evaluation of the whole-larynx specimens did not lead to suspicion of laryngeal metastases. Interestingly, in all six larynx specimens of patients with metastatic prostatic cancer, laryngeal tumor infiltration was detected by macroscopic inspection of horizontal slices and proven histologically. Tumor infiltration ranged from focal micrometastases in the hematopoietic tissue of the ossified laryngeal skeleton to partial destruction of the external and/or internal osseous or cartilaginous lamina of the laryngeal skeleton.

CONCLUSIONS

The larynx is more often affected in metastatic prostatic cancer disease than is suggested by clinical experience. Because prostatic cancer metastasis starts in the hematopoietic areas of the ossified laryngeal skeleton, macroscopic evaluation of the whole larynx fails to detect metastases. Detecting laryngeal involvement requires horizontal slices and histological analysis.

[Aetiology of Angiofibromas: Reflection on their Specific Vascular Component]

BACKGROUND

Even though numerous theories have speculated either on the vascular or fibrous tumour component as tissue of origin, aetiology of angiofibroma still remain unclear. Histological investigations recently led Beham and coworkers to the assumption that angiofibromas have to be considered as vascular malformations.

METHODS

After giving a literature review of the various theories on tumour origin the proposal to consider angiofibromas as vascular malformations is discussed on an embryological base. Taking typical clinical features of the tumour and knowledge of vasculogenesis into account a new explanation for origin of the vascular tumour component is presented.

RESULTS

The vascular component of angiofibromas can be explained embryologically due to incomplete regression of the first branchial arch artery (vascular atavism). This vessel arises regularly between embryological day 22 and 24 and recedes during regular development completely until delivery via temporary formation of a vascular plexus. In the late stages of embryological development remnants of the plexus are found at the area of the sphenopalatine foramen, the typical site of angiofibroma origin. Incomplete regression of the vascular plexus of the former first branchial arch artery may form the vascular component of an angiofibroma arising due to growth stimulation at the time of adolescents.

CONCLUSIONS

Incomplete regression of the first branchial arch artery presenting an atavism is suited to explain the vascular tumour component of angiofibromas considering main tumour characteristics (origin in the posterior nasal cavity close to the sphenopalatine foramen, main blood supply from the maxillary artery with possible feeders arising from the internal carotid artery). Our embryological contributions support to define angiofibromas as vascular malformations.

First evidence of genetic imbalances in angiofibromas

OBJECTIVE/HYPOTHESIS

Angiofibromas are clinically well characterized by their origin at the posterior lateral nasal wall close to the sphenopalatine foramen, their occurrence in male adolescent patients, and the histological findings of a benign fibrovascular neoplasm with irregular, endothelium-lined vascular spaces in a fibrous stroma. However, their etiology and genetic causes remain unknown. The present study addresses genetic imbalances in angiofibromas.

STUDY DESIGN

The present pilot study compared genomic hybridization in three angiofibromas to search for chromosomal abnormalities in this rare tumor.

METHODS

Fluorescence-marked normal DNA and angiofibroma DNA were compared using genomic hybridization screening to detect chromosomal abnormalities. Their binding ratio to metaphase chromosomes were analyzed by special digital image analysis.

RESULTS

Chromosomal gains and losses showing a high level of agreement were detected in all three angiofibromas. Specifically, DNA gains were observed on chromosomes 3q, 4q, 5q, 6q, 7q, 8q, 12p, 12q, 13q, 14q, 18q, 21q, and X, and DNA losses were screened on chromosomes 17, 19p, 22q, and Y. Finding chromosomal abnormalities at the sex chromosomes X and Y of this rare tumor is remarkable. Concurrent chromosomal gain on 8q12q22 was noted in all three tumor specimens.

CONCLUSIONS

Comparative genomic hybridization is suitable for screening angiofibromas on a genetic level. The results on these screens indicate that further genetic investigations of this rare benign tumor may provide more details about the tumor's genetic abnormalities and perhaps clarify the etiology of angiofibromas.

Magnetic resonance imaging in patients with sudden hearing loss, tinnitus and vertigo

OBJECTIVE

The etiopathogenesis in audiovestibular symptoms can be elusive, despite extensive differential diagnosis. This article addresses the value of magnetic resonance imaging (MRI) in analysis of the complete audiovestibular pathway.

STUDY DESIGN

Retrospective evaluation.

SETTING

Tertiary referral center.

PATIENTS

Consecutive sample of 354 patients (mean age 49 years, range 8 to 86 years) with audiovestibular disorders.

INTERVENTION

Contrast-enhanced MRI of the head with thin-slice investigation of the inner ear, internal auditory meatus, and cerebellopontine angle.

MAIN OUTCOME MEASURE

All MRIs were evaluated by experienced independent investigators. Statistical analysis was performed using the Statistical Package of Social Sciences data analysis 9.0.

RESULTS

MRI abnormalities were seen in 122 of 354 patients (34.5%). The MRIs revealed the following: 4 pathologic conditions (1.1%) of the cochlea/labyrinth, 23 abnormalities (6.5%) at the internal auditory meatus/cerebellopontine angle, 12 pathologic lesions (3.4%) that involved the central audiovestibular tract at the brainstem, 78 microangiopathic changes of the brain (22%), 3 focal hyperintensities of the brain that turned out to be the first evidence of multiple sclerosis in 2 patients and sarcoidosis in 1 patient, and 1 temporal metastasis. Other pathologic conditions, such as parotid gland or petrous bone apex tumors, were unrelated to the audiovestibular symptoms.

CONCLUSIONS

This study indicates that contrast-enhanced MRI can be used to assess a significant number of different pathologic conditions in patients with audiovestibular disorders.

A novel microperfusion system for the long-term local supply of drugs to the inner ear: implantation and function in the rat model

Local therapy is practiced for middle and inner ear diseases but is usually restricted to cases of ear drum perforation or repeated invasive intratympanic drug application. Perfusion of drugs on the round window or through the scalae of animals using a pump system suggests that the chronic local drug treatment might also be feasible in humans. However, drug delivery systems that are currently on the market involve repeated reimplantation if they are to be used for long-term drug supply. A bone-anchored, totally implantable micro-drug delivery system (MDS) for patient-controlled drug supply has been developed [Lehner et al., 1997]. In this study, we show the first successful long-term in vivo test of the MDS micro-pump in rats. The process of implantation and first functional tests will be described. The biomaterial used to manufacture the delivery system did not cause any inflammation reaction in any of the 9 animals successfully implanted. After activation of the micro-pump, the drug reservoir and port was found to be fluid-tight. Bolus applications of tetrodotoxin (TTX) to the round window induced a transient decrease of evoked brainstem responses. In 2 animals which carried the MDS for more than 8 months the proper functioning of the pumping device was examined in a 2-3 week interval over a 3 month period. The MDS can be autoclaved even after long-term implantation and can then be reused for subsequent implantations. Designed for life-long implantation in humans, the demonstration of an effective long-term drug supply to the inner ear using the MDS provides an encouraging first step towards future long-term drug treatment of the inner ear in humans.

Sternberg's canal--cause of congenital sphenoidal meningocele

We present a case of a 29-year-old female complaining of right-sided watery nasal discharge. Radiological investigations identified an intrasphenoidal meningocele. The origin of the meningocele was pinpointed to the right parasellar region and was confirmed surgically. The parasellar bony defect appeared to be due to persistence of the lateral craniopharyngeal canal (Sternberg's canal). Therefore, we assume a congenital origin for the intrasphenoidal meningocele found in the patient. Acquired bony defects of the sphenoid sinus are unlikely at the fusion planes of the different sphenoid bone components. Knowledge of the complex ontogeny of the sphenoid bone is an important key to differentiating between congenital and acquired sphenoid sinus meningoceles.

The role of endonasal surgery in the management of frontoethmoidal osteomas

Recently endonasal surgery has been considered to be a valuable contribution in the management of paranasal sinus osteoma. A retrospective evaluation study of 34 frontoethmoidal osteomas (23 frontal and 11 ethmoidal osteomas) treated at a tertiary care facility from 1990 to 1999 is presented. Twenty three osteomas (68%) were resected endonasally. Eleven osteomas (32%) were removed using an osteoplastic frontal sinus approach with coronal incision. In 5 cases of huge osteomas originating at the anterior frontal sinus wall, reconstruction of the resected anterior-frontal sinus wall was achieved by autologous outer table grafts harvested from the parietal region. Endoscopic and radiological follow-up ranging from 1 to 32 months showed three incomplete endonasal osteoma resections. Complete osteoma removal was achieved via endonasal revision surgery in two of these cases, while the third small residual osteoma remains under observation. There was no case of osteoplastic osteoma removal where incomplete osteoma resection became obvious during follow-up. Ethmoidal osteomas without extrasinusal extension can be resected endonasally. The endonasal approach should be considered also for frontal sinus osteomas if (1) sufficient frontal sinus access can be achieved endonasally, (2) the osteoma is placed medially to a virtual sagittal plane through the lamina papyracea, and (3) the tumour base is at the inferior part of the posterior frontal sinus wall. We favour the osteoplastic frontal sinus approach with coronal incision if an external approach is required to achieve tumour resection with the best aesthetic results.

Sigmoid and transverse sinus thrombosis after closed head injury presenting with unilateral hearing loss

Sinus thrombosis has rarely been associated with closed head injury; more often, thrombosis of the sigmoid or transverse sinus is caused by otogenic inflammations or tumours, or occurs during pregnancy. Symptoms are frequently vague, while untreated thrombus progression may be fatal due to venous congestion and infarction. We report a 32-year-old man presenting with right hearing loss, tinnitus and headache 2 days after a closed head injury. Neurological examination showed no additional abnormality. The EEG showed focal bifrontal slowing. CT revealed a fracture of the occipital bone. MRI and MRA demonstrated complete thrombosis of the right sigmoid and transverse sinuses. After 2 weeks of intravenous heparin therapy followed by warfarin, the patient's hearing improved and MRI and MRA showed complete recanalisation of the sigmoid and transverse sinuses. Venous sinus thrombosis can be an undetected sequel to head injury. Appropriate imaging studies should be carried out to enable therapy to be started as soon as possible.

Long-term study of endonasal duraplasty and review of the literature

Many different techniques have been proposed to repair frontobasal dura mater lesions. Because of its low morbidity and high success rate, the endonasal approach has become a preferred route for treating cerebrospinal fluid fistulas of the anterior skull base. This article presents a retrospective evaluation of 136 endonasal duraplasties (126 patients) performed between July 1980 and May 1998 at a tertiary care facility. Follow-up consisted of clinical examinations including nasal endoscopy, objective measures, and telephone interviews. The following measures were used to evaluate the results of these duraplasties: postoperative nasal fluorescein endoscopy in 71 cases, computed tomographic cisternography in 2, nasal fluorescein endoscopy with computed tomographic cistemography in 19, magnetic resonance imaging in 6, and nasal fluorescein endoscopy with magnetic resonance imaging in 1. Tight closure was accomplished in 129 dural lesions (94.9%) on the first attempt. In 3 cases, recurrence of cerebrospinal fluid leakage was treated successfully by 1 endonasal revision, and in 1 case, a tight duraplasty was achieved after 2 endonasal revisions. Its high success rate, low rate of morbidity, and good long-term results recommend endonasal duraplasty as a primary treatment modality for frontobasal dural lesions. For extended frontobasal dural lesions, for which intracranial dural repair is the preferred approach, the endonasal approach should be used to close additional dural leaks of the sphenoid sinus.