Organo-erbium systems for optical amplification at telecommunications wavelengths.

Modern telecommunications rely on the transmission and manipulation of optical signals. Optical amplification plays a vital part in this technology, as all components in a real telecommunications system produce some loss. The two main issues with present amplifiers, which rely on erbium ions in a glass matrix, are the difficulty in integration onto a single substrate and the need of high pump power densities to produce gain. Here we show a potential organic optical amplifier material that demonstrates population inversion when pumped from above using low-power visible light. This system is integrated into an organic light-emitting diode demonstrating that electrical pumping can be achieved. This opens the possibility of direct electrically driven optical amplifiers and optical circuits. Our results provide an alternative approach to producing low-cost integrated optics that is compatible with existing silicon photonics and a different route to an effective integrated optics technology.

Detection of Epstein-Barr virus and human papillomavirus in nasopharyngeal carcinoma by the polymerase chain reaction technique.

We used the PCR technique to detect the Epstein-Barr virus (EBV) and human papillomavirus (HPV) DNA in paraffin-embedded tissues from Greek patients with nasopharyngeal carcinoma (NPC). The oligonucleotide primers used for the detection of EBV amplify a 375-bp long sequence from the EcoRI B fragment of the viral genome, whereas for HPV the primers amplify a 151-bp long sequence of the viral genome. The PCR products were analysed by agarose gel electrophoresis and visualised by UV illumination after staining with ethidium bromide. Sixty-three specimens were examined. EBV specific sequence was amplified in 20 (32%) and HPV in 12 (19%) out of the 63 samples. There was no co-infection with EBV and HPV. Although there is a high correlation of EBV infection with poorly differentiated NPC in patients from Southern China and South-East Asia, the restricted distribution suggests genetic or environmental cofactors in the development of the neoplasm. Our results confirm this suggestion since there was only a 32% correlation of EBV with NPC in Greece. HPV may also be involved in the carcinogenesis of EBV-negative squamous cell nasopharyngeal carcinomas.

Prognostic significance of p53, bax and bcl-2 gene expression in patients with laryngeal carcinoma.

AIM: This study was designed to examine the prognostic significance of the coexpression of three genes (bax, bcl-2 and p53) which play a critical role in the apoptotic mechanisms in patients with squamous cell laryngeal carcinoma. MATERIALS AND METHODS: The immunohistochemical expression of bcl-2, bax and p53 genes was retrospectively examined in 38 patients with squamous cell laryngeal carcinoma and in five controls (necrotomic tissue). Tissue specimens were obtained both during the diagnostic biopsy and at the time of surgery. Clinicopathological and survival data were correlated with the staining results. RESULTS: Bcl-2 protein expression (P=0.0472), stage (P=0.0087) and lymph-node involvement (P=0.0488) were found to be independent prognostic factors. Increased bcl-2 protein expression correlated with a better 5-year survival (P=0.0472). Patients who were bcl-2(-)/p53(-) (n=25) or bax(+)/bcl-2(-) (n=13) had a significantly worse overall survival (P=0.0305 and P=0.0482, respectively). Similarly, patients who were bax(+)/bcl-2(-)/p53(-) (n=11) also had a worse 5-year survival compared with the rest of the group (P=0.0088). Changes that were noticed in bax and p53 protein expression from the time of biopsy until the time of surgery did not correlate with a significant increase in the overall survival. CONCLUSIONS: The expression of bcl-2 gene appears to be an independent prognostic factor for patients with laryngeal carcinoma. The coexpression of the genes studied can be used to determine aggressive clinical phenotypes.

Topoisomerase II alpha expression in squamous cell carcinomas of the head and neck.

The aim of the present study was to examine topoisomerase II alpha (topo II alpha) expression in cancers of the head and neck and to establish a correlation with clinicopathological parameters and survival. Paraffin embedded tissue specimens (studied by immunohistochemistry), from 103 consecutive patients with squamous cell carcinoma of the head and neck regions, were examined on the primary tumor (96 patients) and on recurrence (7 patients). Immunostaining evaluation was quantified by examining at least 1,000 neoplastic cells and counting the percentage of positively stained nuclei. Topoisomerase II alpha expression was correlated with age, gender, stage, site of the disease, tumor differentiation, response to chemotherapy, disease-free survival and overall survival. More than half of the specimens had a high expression of topoisomerase II alpha (> or = 15% positive neoplastic cells). Topoisomerase II alpha expression was significantly higher in tumors of low and moderate differentiation versus tumors of high differentiation (P = 0.00001). There was also a significant difference in topo II alpha in specimens of responders to chemotherapy versus non-responders (P = 0.02), although the cytotoxic drugs used do not belong to topoisomerase II alpha antagonists. The correlation of high topoisomerase II alpha expression and stage of disease, age, gender, primary site, recurrence, disease-free survival and overall survival was not statistically significant. In conclusion, topoisomerase II alpha is highly expressed in histological specimens of the majority of patients with head and neck cancers; mainly, it is related to a significant degree to low and moderately differentiated tumors versus highly differentiated ones. High expression of topoisomerase II alpha is also significantly related to response to chemotherapy.

p53, p21 and p27 protein expression in head and neck cancer and their prognostic value.

Histological specimens from 62 laryngeal and 31 oral carcinomas were immunohistochemically assessed for p53, p21 and p27 proteins; cases with > 10% labelled nuclei were considered as positive. p21 showed higher expression in patients > 65-years-old (P = 0.04), in chemotherapy responders (P = 0.02), and in stage III patients with longer overall survival (P = 0.02), representing the only independent prognostic factor in the multivariate analysis. In addition, stage III patients with p53-/p21+ showed the longest survival whereas those with p53+/p21- tumors showed the shortest overall survival (P = 0.02). A significant influence on the survival of stage III patients was also found for the combinations of p21 and p27 proteins with p21+/p27- imparting the best and p21-/p27+ the worst prognosis (P = 0.04). p27 expression was significantly related to oral cancer specimens (P = 0.04) and to moderate and high tumor grade (P = 0.01). p53 expression was not significantly related to any of the examined clinicopathological characteristics. Our findings indicated that, by functionally promoting apoptosis, p21 seems to play a key role in the successful response to chemotherapy and may be considered as a predictive factor of a better prognosis in stage III patients with head and neck cancers.

Middle ear adenomatous tumor with a predominant neuroendocrine component.

A primary adenomatous tumor of the middle ear was examined by light microscopy, ultrastructural and immunohistochemical techniques. In support of its extensive neuroendocrine differentiation, was the diffuse detection of neuron-specific enolase (NSE) and positive immunoreaction with antibodies to chromogranin and synaptophysin. The great majority of tumor cells contained neurosecretory granules and intraluminal mucin production could be focally detected. These characteristics confirm the diagnosis of a middle ear adenomatous tumor (MEAT) of a biphasic nature and with a prominent neuroendocrine component.

Value of Gd-DTPA-enhanced MR imaging of the labyrinth in patients with sudden hearing loss.

Recent reports describe labyrinthine enhancement on MRI as a highly specific sign of labyrinthine disease. This paper reports 44 patients with unilateral sensorineural hearing loss (SNHL) and laboratory evidence of cochlear damage investigated with Gd-enhanced MR imaging. Enhancement of the cochlea was observed in only one patient with a lesion at the fundus of the internal auditory canal (IAC) that extended into the cochlea after Gd-DTPA administration. In one more patient, MR imaging demonstrated large vestibular aqueducts as underlying cause for his hearing loss, but no enhancement of the labyrinth was observed. No abnormal signal intensity on precontrast MR scans nor pathologic enhancement of the membranous labyrinth were identified in the other 42 patients. Gd-enhanced MR imaging appears to be insensitive in demonstrating labyrinthine disease and normal examination findings in a patient with sudden SNHL cannot exclude damage at the cochlear level.

Modified supracricoid partial laryngectomy with cricohyoidopexy: series report and analysis of results.

Aiming to improve voice quality and to facilitate swallowing rehabilitation, we modified the supracricoid partial laryngectomy with cricohyoidopexy by preserving the posterior segment of the true vocal cord on the less involved side of the larynx. Between 1983 and 1994, 13 patients with supraglottic cancer were treated with this modified procedure. The possibility of incomplete tumor excision was eliminated by careful patient selection and intraoperative reconfirmation of tumor extent with frozen sections. Our results have been promising, with a 76.9% 3-year survival rate and a 69.2% laryngeal preservation rate. There were 7 recurrences, 3 local (2 at the superior border of the cricoid and 1 at the cricoarytenoid region) and 4 nodal, in 5 patients. Distant metastases developed in another patient. Three patients, 2 with local and nodal recurrence and 1 with distant metastases, died of disease. Functional outcomes were also good, with all patients achieving normal swallowing by the end of the first year, although 5 patients required temporary gastrostomy for transient swallowing impairment. Early decannulation and satisfactory voice quality were achieved in all cases. We believe that with proper patient selection this modified procedure is effective both for tumor control and for preserving a more functional larynx.

Multiple-frequency tympanometry in children with acute otitis media.

Multiple-frequency tympanometry (MFT) is a sweep-frequency method of acoustic immittance measurement, recently introduced in clinical practice. It provides values for the resonant frequency of the middle ear system. The purpose of this study was to use MFT to collect information about the mechanoacoustical changes occurring to the middle ear system after acute otitis media and to compare it with the results of conventional, low probe-tone tympanometry. Children with acute otitis media were followed up with both methods for 1 month after an episode of acute infection. Also, children with normal hearing were studied to establish normative data. Resonant frequency of the middle ear was found to be lower than normal even 1 month past the initial episode, for all types of 226-Hz tympanograms. MFT seemed to record changes in the middle ear after acute otitis media that 226-Hz tympanometry was unable to detect, implying persistence of pathology. More extended research will illuminate the clinical value of this method in the follow-up of acute otitis media.

Management of bilateral vocal fold paralysis: experience at the University of Athens.

The treatment of patients with vocal fold paralysis presents a challenge to the otolaryngologist-head and neck surgeon. Many techniques have been proposed to manage individuals with unilateral or bilateral vocal fold paralysis. We herein describe the experience of our department in dealing with bilateral vocal fold paralysis. At the University of Athens, patients presenting with symptomatic bilateral paralysis are treated with a posterior cordectomy by using the CO2 or KTP-532 laser. During the last 5 years, we have treated 20 patients (8 men and 12 women) presenting with symptomatic bilateral vocal fold paralysis. For augmentation of the glottic airway, a modification of Kashima's cordotomy was used, completing a partial posterior cordectomy of one or both true and false vocal folds with the CO2 laser (15 patients) and the KTP-532 laser (5 patients). An elective tracheotomy was done before the cordotomy. Complications, such as infection, stridor, or dyspnea, were minimal. Although no objective voice analysis was performed, all patients were able to communicate without any phonation device and were satisfied with the result of the surgery. When compared with other techniques, the advantages offered by the posterior cordectomy included rapidity and simplicity in concept, reliability of outcome, short hospitalization, low risk of complications, and the possibility for revision when necessary (posterior cordectomy). From the successful postsurgical results of this study, it can be concluded that the posterior cordectomy is a reliable treatment option for the management of patients with bilateral vocal fold paralysis.

Lectin histochemistry of laryngeal squamous cell carcinomas.

A panel of five biotinylated lectins was applied to study the presence and distribution of membrane carbohydrate residues in the normal laryngeal epithelium and in laryngeal squamous cell carcinomas (SCCs) of 86 patients with the avidin-biotin peroxidase complex technique. The lectin-binding pattern of well-differentiated SCCs was comparable to that of the spinous cells of the normal laryngeal epithelium. In the less differentiated SCCs, staining of the keratinocyte plasma membrane with lectins was either reduced or absent, indicating a decline in the glycosylation of cell surface glycoconjugates. The lectins applied here could be used in the rapid assessment of less-differentiated areas within a laryngeal SCC, but they cannot be regarded as reliable markers of laryngeal keratinocytes undergoing malignant transformation.

Role of the new imaging modalities in the investigation of Meniere's disease.

The incidence of nonvisualization of the vestibular aqueduct and the endolymphatic duct-endolymphatic sac (ED-ES) complex as well as the type of periaqueductal pneumatization were evaluated in 23 patients with definite Meniere's disease (MD) by high-resolution CT and by MRI. Fifty subjects with no previous history of any ear disease were used as a control group. High-resolution CT results disclosed that in the control group the percentage of nonvisualized vestibular aqueduct (3.4%) was statistically significantly lower than in the MD group, when either the diseased ear (27.8%) or the nondiseased ear of the same group (22.2%) was examined. In addition, no differences were observed between the diseased and nondiseased ears of the patients with MD. The periaqueductal pneumatization was also found to be statistically significantly lower in the MD group. As regards the MRI examination, the results of the analysis showed that the ED-ES complex was visualized more frequently in the ears of the control subjects (64.1%) than in the diseased ears of the patients with Meniere's disease (39.1%). This difference had a marginal statistical significance (P approximately 0.05). We discussed the results in relation to possible underlying pathophysiologic mechanisms involving the flow of endolymph toward the ES during the different stages of the disease.

Cervical versus thoracic epidural morphine for the treatment of head and neck cancer pain.

We studied 29 patients in the final stage of head or neck cancer who were suffering pain that was not relieved by oral morphine. Cervical or thoracic epidural morphine was administered to relieve the pain. The quality of analgesia was equally good for both techniques. However, cervical epidural administration appeared to be superior, because much smaller doses of morphine were required in order to induce more rapid and longer analgesia.

Evoked otoacoustic emissions--an approach for monitoring cisplatin induced ototoxicity in children.

OBJECTIVES: Cisplatin chemotherapy is associated with an increased risk of ototoxic changes. The incidence of hearing loss after the 1st cisplatin-infusion session is only scarcely mentioned in the international literature. With increasing survival rates, prevention and/or early detection of ototoxicity are important for providing management options. The predictive value of pure-tone audiometry in early detection of ototoxicity has been questioned, particularly in the higher frequencies. Otoacoustic emissions appear to be more sensitive to cochlear insult than the conventional pure-tone audiometry. The aims of our study was (a) to define the extent of hearing damage in children after the 1st cisplatin-infusion session (50 mg/m(2)); and (b) to compare the efficacy of otoacoustic emissions (transient evoked otoacoustic emissions, distortion-product otoacoustic emissions) with that of pure-tone audiometry as methods of audiological monitoring. METHODS: Baseline audiometric (0.25-8 kHz) and otoacoustic emission testing (transient evoked otoacoustic emissions, distortion-product otoacoustic emissions) was conducted in 19 children, 12 of whom met the criteria for inclusion in the final study. Comparisons were performed between baseline measurements and those recorded after the 1st cisplatin course. Transient evoked otoacoustic emissions were analyzed in terms of emission level and reproducibility as a function of frequency (0.8-4 kHz). Distortion-product otoacoustic emissions were obtained as DP-grams and I/Q functions at 4,6 and 8 kHz. The DP-gram amplitude, the dynamic range and the detection thresholds from the I/Q functions were determined for each child. RESULTS: Threshold changes from baseline were founded to be statistically significant from 4-8 kHz in 50% of the children (P<0.01). Transient evoked otoacoustic emissions revealed a significant decrease in the emission level and in the reproducibility at the highest frequency tested (4 kHz, P<0.01), reflecting the results seen in pure-tone audiometry. Distortion-product otoacoustic emissions demonstrated a significant threshold shift, a reduced dynamic range and a decreased amplitude in the frequencies >3 kHz (P<0.05). Furthermore, DP-gram amplitude also reduced significantly at 3 kHz (P<0.05) without any similar change in pure-tone audiometry. CONCLUSIONS: A significant high-frequency hearing loss is identified in children even after one low-dose cisplatin-infusion session. As ototoxicity screening tools DP-grams were extremely sensitive and superior to pure-tone audiometry and/or transient evoked otoacoustic emissions. Their use is recommended for regular monitoring of cochlear function, aiming in prevention of permanent damage. Some suggestions for reducing the potential for cisplatin ototoxicity (chemoprotective agents, gene therapy, inhibition of apoptosis) are also discussed.

Pleomorphic adenoma of the nose.

Pleomorphic adenoma is the most frequent tumor of the major salivary glands. It is rarely located in the lacrymal glands and is unusual in the nasal cavity. A rare case of a pleomorphic adenoma of the nose is presented along with a review of the literature. The use of nasal endoscopy in removing tumors of the nose and paranasal sinuses is discussed.

Isolated sphenoid sinus aspergillomas.

Fungi are more often than previously believed to be the causative organisms of paranasal sinusitis. Aspergillus, a fungus belonging to the Ascomycetes class, accounts for the majority of these infections, which affect not only debilitated patients but healthy people as well. There are two distinct clinical forms of Aspergillus sinusitis, invasive and non-invasive, and each of them is further divided in two subtypes. Isolated aspergillosis of the sphenoid sinus is a rare disease, which is usually misdiagnosed for a long time because of its varying symptomatology. In the present study, four cases of isolated sphenoid Aspergillus disease are described and the recent literature is reviewed. Physicians should be aware of this rare clinical entity, as in many cases early diagnosis and appropriate treatment provide the key to achieve favourable outcomes.

Intramasseteric metastasis of renal cell carcinoma.

In this case report, we present a solitary metastasis of renal cell carcinoma inside the masseter muscle. To our knowledge, it is the very first case ever encountered.

Localized mastoiditis simulating a facial nerve schwannoma on MRI.

A case of a single inflamed mastoid air cell is described. This was initially interpreted as a facial nerve schwannoma on MRI examination. Careful evaluation of the signal characteristics and additional findings from the high resolution CT examination helped to establish the correct diagnosis.

Isolated inverted papilloma of the sphenoid sinus.

Inverted papilloma is a rare benign sinonasal tumour, characterized by a potentially invasive nature. The lateral nasal wall represents the most common site of origin, whereas paranasal sinuses are quite frequently found to be involved by extension. In contrast, primary sinus inverted papillomas have rarely been reported. The present study describes an extremely rare case of inverted papilloma, isolated to the left sphenoid sinus, that was treated by a transnasal endoscopic procedure. The therapeutic approach chosen is discussed and the results of a two-year follow-up are also presented.

Actinomycosis of the thyroid gland masquerading as a neoplasm.

Actinomycetal infections involving the head and neck often pose a diagnostic puzzle to the otolaryngologist. A rare case of unilateral thyroid swelling due to actinomycosis is described. Although the clinical, laboratory and imaging studies strongly suggested a thyroid neoplasm, the histological examination revealed the presence of Actinomyces sp. in the excised lesion. The manifestations of actinomycosis of the head and neck, its pathogenesis and the difficulties encountered in the diagnosis and treatment of the disease are hereby reviewed.