A Comparison of the Reliability of Five Sleep Questionnaires for the Detection of Obstructive Sleep Apnea

The aim of this study was to compare the reliability of five sleep questionnaires in detecting the occurrence of obstructive sleep apnea (OSA). The study was conducted on a group of 201 patients. The patients completed five sleep questionnaires: the Epworth Sleepiness Scale (ESS), the STOP-Bang questionnaire, the STOP questionnaire, the Berlin questionnaire (BQ) and the Pittsburgh Sleep Quality Index (PSQI). Subsequently, the patients were examined using limited polygraphy, and the sensitivity and specificity of the questionnaires were evaluated. The STOP-Bang, Berlin and STOP questionnaires had the highest sensitivity for OSA detection (81.6%, 78.7%, and 74.2%, respectively), while the sensitivities of PSQI and ESS were low (50.8% and 34.5%). The ESS, STOP-Bang, STOP and Berlin questionnaires had the highest specificity (82.6%, 75%, 61.9%, and 61.9%). In our sample, we found the STOP-Bang and Berlin questionnaires to be the most suitable for OSA screening with the highest sensitivities (81.6%, 78.7%) and satisfactory specificities (75%, 61.9%). The STOP questionnaire was also relatively reliable, especially given its time-saving nature; though short, it preserved satisfactory sensitivity (74.2%) and specificity (61.9%). The ESS and PSQI were unsuitable for OSA screening.

Morbidity and mortality associated with thyroid surgery - retrospective analysis 19912010

INTRODUCTION

The incidence of thyroid disorders has been rising worldwide. Unlike the incidence, mortality associated with malignant thyroid cancer shows only a modest increase. Between 1979 and 2009, mortality in Czech women increased from 1.21 to 1.31 and in Czech men from 0.54 to 0.74 cases per 100,000 individuals.  Methods: A retrospective statistical analysis was performed in patients undergoing thyroid surgery at the Department of Otorhinolaryngology and Head and Neck Surgery of the 1st Faculty of Medicine, Charles University and University Hospital Motol, and at the Department of Otorhinolaryngology of the Institute for Postgraduate Medical Education in Prague from 1991 to 2010 (twenty years). In this period, 11,005 procedures were done for thyroid disease. The study analysed the incidence, morbidity, mortality, surgical complications and lethality.

RESULTS

The study group included surgeries in 1588 male and 9417 female patients. The male/female ratio was 1:5.93. Benign thyroid tumours - mean patient age is 54.7 years; recurrent nerve morbidity is 1.37% (calculated from exposed nerves). Hypocalcaemia incidence is low, 5.4% of permanent hypocalcaemia or hypoparathyroidism, respectively, based on decreased serum parathyroid hormone (PTH) levels. Temporary hypocalcaemia is much more frequent, occurring in almost 15% cases depending on age, season of the year, and nutritional status. Hypoparathyroidism was demonstrated based on laboratory serum PTH levels only in 0.3% patients. In total, 442 patients were operated for the mechanic syndrome (a large goitre). The mean thyroid volume was 493 ml±136 ml; however, the maximum volume was 980 ml and weight 1115 g. The incidence of recurrent nerve injury occurs in 4.5%, i.e. the morbidity is 2 times higher compared to surgeries for other diagnoses. The incidence of hypoparathyroidism is not higher compared to other surgeries. Revision surgeries were indicated more commonly in malignant thyroid diseases, particularly in papillary and follicular carcinomas. Cervical lymph nodes procedures comprise another large segment in tumour treatment. Our analysis supports selective neck dissections while preserving non-lymphatic structures. As a rule, mortality associated with thyroid surgery is divided as mortality in the perioperative period (within 24 hours after the procedure) and early postoperative mortality (within 120 hours after the procedure). Surgery-related mortality was never classified as perioperative or within 24 hours after the procedure. Despite that, we believe that perioperative mortality within 120 hours after the procedure, which occurred in 7 cases, is very important. Mortality of the group was 0.007%.

CONCLUSIONS

Each surgery procedure is associated with complications, morbidity and mortality. Experience of endocrine surgeons of all disciplines leads to a very low incidence of recurrent nerve and parathyroid gland injuries while at the same time achieving sufficient radicality. This, in cooperation with other medical fields such as endocrinologists, nuclear medicine specialists and oncologists, supports a safe and effective management of all thyroid disorders, including a good prognosis of patients with most types of cancer. Key word: thyroid surgery - complications recurrent nerve - hypoparathyroidism lethality.

Biomarkers - a possibility for monitoring of obstructive sleep apnea syndrome

OBJECTIVES

Sleep apnea syndrome affects approximately 4% of adult males and 2% of adult females. It is associated with significant cardio-, cerebrovascular, metabolic and hormonal comorbidities and ranks among the more expensive medical specialties due to the requirement of high-quality technical diagnostic and therapeutic equipment as well as well-educated and experienced personnel. The aim of this study is to detect the relationship between C-reactive protein (CRP), pentraxin-3 (PTX-3), interleukin 6 (IL6), high-sensitivity troponin I (hsTnI), brain natriuretic protein (BNP) and galectin-3 serum levels and obstru-ctive sleep apnea syndrome.

DESIGN

Prospective cohort study.

MATERIAL AND METHODS

A group of 146 patients with middle to severe obstructive sleep apnea syndrome (OSAS) were monitored, and the results were compared with the results from a control group of healthy individuals.

RESULTS

We assessed serum levels of the following biomarkers: CRP, PTX-3, IL6, hsTnI, BNP, and galectin-3. PTX-3 serum levels were statistically significantly higher (p<0.0001) in patients with OSAS, compared to controls. Statistical results related to the other biomarkers did not suggest any clinical value. ROC analysis showed that PTX-3 might be able to distinguish patients with OSAS from healthy individuals (AUC=7438).

CONCLUSION

The elevation of PTX-3 serum levels is significantly associated with middle to severe obstructive sleep apnea syndrome. The PTX-3 biomarker appears to be a promising alternative method for sleep apnea syndrome investigations.

Otorhinolaryngology and sleep disorders

In the field of sleep disorders, otorhinolaryngology is mainly concerned with snoring and obstructive sleep apnea (OSA). Prevalence of OSA is suggested between 14-49 % of male and 5-30 % of female population, which makes it most common sleep disorder. The treatment of choice is positive airway pressure (PAP) therapy with excellent success rate of 90 %, however many patients dont tolerate it. Sleep surgery is usually used to get off snoring and for mild cases of OSA. Most of surgical approaches has much lower effectivity than PAP therapy; however, surgery benefit is present constantly, while PAP therapy demands patients cooperation, that is why many patients still prefer sleep surgery.

The influence of smoking, age and stage at diagnosis on the survival after larynx, hypopharynx and oral cavity cancers in Europe: The ARCAGE study

Head and neck cancer (HNC) is a preventable malignancy that continues to cause substantial morbidity and mortality worldwide. Using data from the ARCAGE and Rome studies, we investigated the main predictors of survival after larynx, hypopharynx and oral cavity (OC) cancers. We used the Kaplan-Meier method to estimate overall survival, and Cox proportional models to examine the relationship between survival and sociodemographic and clinical characteristics. 604 larynx, 146 hypopharynx and 460 OC cancer cases were included in this study. Over a median follow-up time of 4.6 years, nearly 50% (n = 586) of patients died. Five-year survival was 65% for larynx, 55% for OC and 35% for hypopharynx cancers. In a multivariable analysis, we observed an increased mortality risk among older (≥71 years) versus younger (≤50 years) patients with larynx/hypopharynx combined (LH) and OC cancers [HR = 1.61, 95% CI 1.09-2.38 (LH) and HR = 2.12, 95% CI 1.35-3.33 (OC)], current versus never smokers [HR = 2.67, 95% CI 1.40-5.08 (LH) and HR = 2.16, 95% CI 1.32-3.54 (OC)] and advanced versus early stage disease at diagnosis [IV versus I, HR = 2.60, 95% CI 1.78-3.79 (LH) and HR = 3.17, 95% CI 2.05-4.89 (OC)]. Survival was not associated with sex, alcohol consumption, education, oral health, p16 expression, presence of HPV infection or body mass index 2 years before cancer diagnosis. Despite advances in diagnosis and therapeutic modalities, survival after HNC remains low in Europe. In addition to the recognized prognostic effect of stage at diagnosis, smoking history and older age at diagnosis are important prognostic indicators for HNC.

[The Tear Osmolarity of PATIENTS with Lagophthalmos]

INTRODUCTION

Lagophthalmos can be characterized as the dysfunction of the eye aperture and in some cases even by the disruption of tear production. Dry eye syndrome can consequently develop. Instability of the tear film, hyperosmolarity and inflammatory reaction are considered as the key mechanisms of dry eye syndrome. In our report we monitored the tear osmolarity of patients with postsurgical unilateral lagophthalmos. Results were compared with tear osmolarity of the non-lagophthalmic eyes.

METHODS

We examined 10 patients (6 women, 4 men) with postsurgical facial nerve palsy and lagophthalmos complicating management of either cerebellopontine (8 patients) or salivary gland tumors (2 patients). Only patients without severe corneal defects enrolled the study. The tear osmolarity was measured in lower tear meniscus by TearLab Osmolarity System device. The lagophthalmic eye was always examined first. The results are presented as mean plus/minus the standard deviation. The paired t-test was used for statistical data processing. The p-value 0,05 was considered as statistically significant.

RESULTS

The mean tear osmolarity of the lagophthalmic eyes was 296 ± 15,0 mosmol/l (275-315 mosmol/l). In case of healthy eyes the mean osmolarity was 310 ± 12 mosmol/l (292-336 mosmol/l). The tear osmolarity in case of lagophthalmos was significantly lower than in the healthy eyes (p = 0,05).

CONCLUSION

In contrary to the studies demonstrating higher tear osmolarity under the scenario of dry eye syndrome, we found lower tear osmolarity in the lagophthalmic eyes than in the healthy eyes. The possible reason could be the changes in tear dynamics of the lagophthalmic eye due to disturbance of eye lid function. Our results also stress the need of evaluation of the actual tear osmolarity in the view of complex clinical eye findings. The place of tear collection should also be considered.Key words: lagophthalmos, dry eye syndrom, tear osmolarity.

A 3-bp Deletion VK600-1E in the BRAF Gene Detected in a Young Woman with Papillary Thyroid Carcinoma

Papillary thyroid cancer (PTC) derived from follicular cells is a frequent thyroid tumor. The incidence of this type of malignancy is still growing worldwide. Several major genetic causes are recognized to cause PTC-mutations in the BRAF and RAS genes or rearrangements with the RET proto-oncogene. The most common genetic change found in PTC is a V600E mutation in the BRAF gene presented in 36-69 % of all PTC cases. For routine purposes, several methods were developed to selectively detect only this mutation. However, these methods miss other mutations in the BRAF gene located elsewhere. We focused on the analysis of the exon 15 of the BRAF gene by next-generation sequencing. Here we report a three nucleotide deletion VK600-1E in one patient and present this finding in the context of 13 previously described PTC cases with this deletion. Our patient is the second youngest one among the reported cases. Clinical features of PTC patients with VK600-1E are summarized. For the future, it is important to evaluate genotype-phenotype characteristics of patients with rare BRAF mutations and to follow up them for years.

Comparison of Helicobacter Pylori Genotypes Obtained from the Oropharynx and Stomach of the Same Individuals – A Pilot Study

Helicobacter pylorihas been recently detected in the oral cavity and oropharynx. However, the role it plays in oral and oropharyngeal pathogenesis remains unclear. The virulence ofH. pyloristrains can be distinguished according to the virulence factors genes carried. Our research has been focused on realtime PCR analysis ofcagAandvacAgenes ofH. pyloristrains in tonsils and tonsillar squamous cell cancer and their comparison withH. pyloristrains obtained from the gastric mucosa of the same patients. Urea breath test (UBT) test was used to detect a gastricH. pyloriinfection in 20 patients with previously provenH. pyloriin the oropharynx. Genotyping ofH. pyloriin gastric biopsies was performed in patients with positive gastric infection. Out of 20 patients positive for oropharyngealH. pylori, 8 were positive for concurrent gastricH. pyloriinfection. In 6 of them gastric biopsies were obtained. Comparison of oropharyngeal and stomachH. pylorigenotypes showed important differences. Four of 6 patients had differentH. pyloristrains in the oropharynx and stomach. The differences were found incagAgene as well as invacAgene. The finding of oral presence ofH. pyloriwithout concurrent stomach infection was confirmed using UBT. The results show that more than oneH. pyloristrain can be present in oropharynx and stomach in the same patient. The oropharyngeal infection seems to be independent to the gastric infection.

Revision operations after previous stapes surgery for persisting hearing loss

OBJECTIVES

The aim of the study was to find out the reasons of the recurrent or persisting hearing loss after previous stapes surgery indicated for otosclerosis.

BACKGROUND

Revision stapes surgery is a relatively safe surgical method. Recurrent or persisting conductive hearing loss is commonly caused by prosthesis dislocation and adhesions in the oval window. Hearing loss is directly proportional to the number of previous operations.

METHOD

Retrospective analysis of 48 patients after revision stapes surgery was done over a period of 4 years (2005-2008). Improvement of the hearing and the reasons of a previous surgery failure were studied.

RESULTS

RESULTS were compared to the other studies. The main reason of the failed surgery was adhesions and dislocation of the prosthesis. The mean postoperative air-bone gap was 12.0 dB. A mean postoperative air-bone gap closure within 10 dB occurred in 24 cases (55.8 %), between 11-20 dB occurred in 11 cases (25.6 %) and above 20 dB in 8 cases (18.6 %). The original prosthesis was replaced with a new one in 41 (95.3 %) cases. In 2 cases (4.7 %), previous prostheses were left in place and fixed by a ionomer glass cement to the long process of incus.

CONCLUSION

Revision stapes surgery is a relatively safe surgical procedure allowing to improve hearing. The number of previous stapes surgery deteriorates hearing (p < 0.05) (Tab. 4, Ref. 20).

Towards dissecting molecular routes of intercellular communication in the tumour microenvironment: phenotypic plasticity of stem cell-associated markers in co-culture (carcinoma cell/fibroblast) systems

Increasing evidence attributes tumour fates to a small population of cells (cancer stem cells) capable of surviving therapeutic interventions. Investigation of their characteristics, especially in cross-talk with other cell types of the tumour microenvironment, can pave the way to innovative therapeutic concepts. The central issue of this study was to evaluate the impact of stroma on tumour cells with stem cell-like features in a squamous cell carcinoma model (FaDu). Six different types of experimental conditions were tested using distinct compositions of the culture system, and both morphologic and molecular features of the tumour cells were analysed. In detail, FaDu cells alone were used as a control, compared to tumour cells from co-culture, with squamous cell cancer-derived stromal fibroblasts or normal skin human fibroblasts, both in the direct and indirect (insert) systems, adding analysis of side population cells of FaDu culture. Measurements were taken on days 2, 7 and 9 of culture and immediately after preparation in the case of the side population. A panel of antibodies against keratins 8, 10, 19, stem cell markers CD29, CD44, CD133, as well as biotinylated adhesion/growth-regulatory galectin 1 served as a toolbox for phenotypic characterization. Co-culture with fibroblasts prepared from tumour stroma and with dermal fibroblasts affected marker presentation, maintaining an undifferentiated stage phenotypically related to stem cells. Side-population cells showed close relationship to cancer stem cells in these characteristics. In conclusion, normal and tumour stromal fibroblasts are capable of shifting the marker expression profile of FaDu cells to a stem cell-like phenotypic pattern in co-culture.

Combined bipolar radiofrequency surgery of the tongue base and uvulopalatopharyngoplasty for obstructive sleep apnea

INTRODUCTION

The aim of the study was to investigate the effectiveness of combined bipolar radiofrequency surgery of the tongue base (RFBT) and uvulopalatopharyngoplasty (UPPP) in a single session for obstructive sleep apnea and whether this combination is safe and well tolerated.

MATERIAL AND METHODS

Seventy-nine patients with obstructive sleep apnea and both palatal and retroglossal obstruction underwent UPPP with bipolar RFBT. The control group consisted of 35 patients treated by UPPP alone.

RESULTS

The apnea-hypopnea index significantly decreased from 28.7 to 14.1. The oxygen desaturation index decreased from 15.1 to 10.3. Mean oxygen saturation was unchanged. Subjectively, the Epworth Sleepiness Scale was significantly improved from 10.6 to 7.3, and the snoring level decreased from 8.4 to 6.0. The overall treatment success rate increased from 41.9% for UPPP alone to 51.7% for UPPP + RFBT. No serious adverse events occurred. Two patients had postoperative bleeding from the tonsillar bed after UPPP. Four patients had ulceration of the base of the tongue after RFBT with spontaneous cure. One patient had a taste change in half of the tongue that resolved within two months.

CONCLUSIONS

Combined bipolar RFBT and UPPP in a single session is well tolerated and safe surgery in the treatment of obstructive sleep apnea. It is effective in reducing respiratory parameters and subjective symptoms of obstructive sleep apnea. Further advantages are a single session, simple feasibility, bipolar technique and short time of the procedure.

Adult height and head and neck cancer: a pooled analysis within the INHANCE Consortium

Several epidemiological studies have shown a positive association between adult height and cancer incidence. The only study conducted among women on mouth and pharynx cancer risk, however, reported an inverse association. This study aims to investigate the association between height and the risk of head and neck cancer (HNC) within a large international consortium of HNC. We analyzed pooled individual-level data from 24 case-control studies participating in the International Head and Neck Cancer Epidemiology Consortium. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated separately for men and women for associations between height and HNC risk. Educational level, tobacco smoking, and alcohol consumption were included in all regression models. Stratified analyses by HNC subsites were performed. This project included 17,666 cases and 28,198 controls. We found an inverse association between height and HNC (adjusted OR per 10 cm height = 0.91, 95% CI 0.86-0.95 for men; adjusted OR = 0.86, 95% CI 0.79-0.93 for women). In men, the estimated OR did vary by educational level, smoking status, geographic area, and control source. No differences by subsites were detected. Adult height is inversely associated with HNC risk. As height can be considered a marker of childhood illness and low energy intake, the inverse association is consistent with prior studies showing that HNC occur more frequently among deprived individuals. Further studies designed to elucidate the mechanism of such association would be warranted.

[Current treatment strategies for papillary thyroid microcarcinoma]

The increase in the incidence of thyroid cancer is accompanied by a mortality rate that is stable or perhaps even slightly decreasing. This phenomenon is due to the increased frequency of papillary microcarcinomas (thyroid tumors with a diameter of less than 1 cm), which is presumably attributable to the improved diagnosis enabled by high resolution ultrasound and fine needle aspiration cytology. The American and European Thyroid Associations have recently published new guidelines for the diagnosis and therapy of differentiated thyroid tumors. These guidelines are aimed at minimizing the diagnostic and therapeutic procedures without reducing their effectiveness. This goal is particularly important for papillary thyroid microcarcinoma patients, who have an excellent prognosis and almost normal life expectancy. This article summarizes the history of thyroid surgery and introduces papillary thyroid microcarcinoma--an important topic in modern thyroid oncology. Current methods for diagnosis, treatment and follow-up care of this disease are discussed.

Smoking addiction and the risk of upper-aerodigestive-tract cancer in a multicenter case-control study

Although previous studies on tobacco and alcohol and the risk of upper-aerodigestive-tract (UADT) cancers have clearly shown dose-response relations with the frequency and duration of tobacco and alcohol, studies on addiction to tobacco smoking itself as a risk factor for UADT cancer have not been published, to our knowledge. The aim of this report is to assess whether smoking addiction is an independent risk factor or a refinement to smoking variables (intensity and duration) for UADT squamous cell carcinoma (SCC) risk in the multicenter case-control study (ARCAGE) in Western Europe. The analyses included 1,586 ever smoking UADT SCC cases and 1,260 ever smoking controls. Addiction was measured by a modified Fagerström score (first cigarette after waking up, difficulty refraining from smoking in places where it is forbidden and cigarettes per day). Adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for UADT cancers with addiction variables were estimated with unconditional logistic regression. Among current smokers, the participants who smoked their first cigarette within 5 min of waking up were two times more likely to develop UADT SCC than those who smoked 60 min after waking up. Greater tobacco smoking addiction was associated with an increased risk of UADT SCC among current smokers (OR = 3.83, 95% CI: 2.56-5.73 for score of 3-7 vs. 0) but not among former smokers. These results may be consistent with a residual effect of smoking that was not captured by the questionnaire responses (smoking intensity and smoking duration) alone, suggesting addiction a refinement to smoking variables.

Early stages of trachea healing process: (immuno/lectin) histochemical monitoring of selected markers and adhesion/growth-regulatory endogenous lectins

Tracheotomy may be associated with numerous acute and chronic complications including extensive formation of granulation tissue. The emerging functional versatility of the adhesion/growth-regulatory galectins prompted us to perform a histochemical study of wound healing using rat trachea as model. By using non-cross-reactive antibodies and the labelled tissue lectins we addressed the issue of the presence and regulation of galectin reactivity during trachea wound healing. Beside localization of high-molecular-weight keratin, wide-spectrum cytokeratin, keratins 10 and 14, α-smooth muscle actin, vimentin, fibronectin, and Sox-2, galectins -1, -2, and -3 and their reactivity profiles were measured in frozen sections of wounded and control trachea specimens 7, 14, and 28 days after trauma. A clear trend for decreased galectin-1 presence and increased reactivity for galectin-1 was revealed from day 7 to day 28. Sox-2-positive cells were present after seven days and found in the wound bed. Interestingly, several similarities were observed in comparison to skin wound healing including regulation of galectin-1 parameters.

Subcutaneous calcification in the pectoralis major flap: a late complication of radiotherapy

Heterotopic calcification following radiotherapy is a very rare event. Here, we report a case of a patient who underwent surgical intervention including pectoralis major flap reconstruction for locally advanced pharyngolaryngeal squamous cell carcinoma with skin invasion. He was followed up post-operatively with adjuvant radiotherapy. 13 years after the treatment, suspect resistance in the myocutaneous flap region appeared and was diagnosed as a calcification. To date, the occurrence of subcutaneous calcification in the myocutaneous flap in the neck has not been described as a late complication of neck irradiation.

Impact of Regulatory T Cells in Oropharyngeal Cancer

Objective: Oropharyngeal cancer is the most frequent type of malignancy in the head and neck area. Regulatory T cells (Treg, CD4+CD25+Foxp3+) and Th17 cells were described as critical factors for regulation or inhibition of effective anti-cancer immune response and, consequently, prognosis and survival.

Method: We examined Treg and Th17 from periphery blood and tumor samples of patients with oropharyngeal cancer before the start of anti-tumor therapy. We particularly focused on lymphocytes subpopulations (CD3+, CD3-CD16+CD56+, CD4+, CD8+, CD19+, CD4+CD45RA+, CD3+CD4+CD25+, CD161+CD4+ a CD161+CD8+) and tumor markers (SCC, CEA, AAT, Cyfra 21-1).

Results: In comparison with control group (nononcologic surgery), the Treg population in the peripheral blood of the patients with oropharyngeal cancer was 1.6-fold higher. Infiltration of Treg in specimens from primary tumors and metastatic neck lymph nodes was higher (8.7% and 9.6%) in comparison with oropharyngeal tissue and neck lymph nodes without tumor or metastatic extension (3.12% and 3.3%, both p+CD161+cells and 12.8% CD8+CD161+ cells, and in tumor tissue, 1.66% CD4+CD161+ cells and 3.9% CD8+CD161+ cells. Level of tumor marker CEA correlated with higher T stadium (T3+4, t-test, P < .005).

Conclusion: We can conclude that regulatory T cells and Th17 generally represent a highly important factor in the progression of many types of malignancies and our data indicated their particular importance for oropharyngeal cancer.

Short-term health-related quality of life and symptom control with docetaxel, cisplatin, 5-fluorouracil and cisplatin (TPF), 5-fluorouracil (PF) for induction in unresectable locoregionally advanced head and neck cancer patients (EORTC 24971/TAX 323)

Background:

The EORTC 24971/TAX 323, a phase III study of 358 patients with unresectable locoregionally advanced squamous cell carcinoma of the head and neck, showed an improved progression-free and overall survival (OS) with less toxicity when docetaxel (T) was added to cisplatin and 5-fluorouracil (PF) for induction and given before radiotherapy (RT). The impact of the addition of docetaxel on patients’ health-related quality of life (HRQOL) and symptoms was investigated.

Methods:

HRQOL was assessed at baseline, at end of cycle 2, and 4, 6, and 9 months after completion of RT using the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire C30 (QLQ-C30) and the EORTC QLQ Head and Neck Cancer-Specific Module (EORTC QLQ-H&N35). The primary HRQOL scale was global HRQOL per protocol.

Results:

Compliance to HRQOL assessments was 97% at baseline, but dropped to 54% by 6 months. Data were analysed up to 6 months. There was a trend towards improved global HRQOL during the treatment period. At 6 months after the end of RT, global HRQOL was higher in the TPF arm than in the PF arm, but the low compliance does not allow to draw definitive conclusions. Swallowing and coughing problems decreased more in the TPF arm than in the PF arm at the end of cycle 2, but to a limited extent.

Conclusion:

Induction chemotherapy with TPF before RT not only improves survival and reduces toxicity compared with PF but also seems to improve global HRQOL in a more sustainable manner.

BRAFV600E mutation in the pathogenesis of a large series of papillary thyroid carcinoma in Czech Republic

BACKGROUND

Activating point mutation of the BRAF gene, the most common genetic alteration reported in papillary thyroid carcinomas (PTC), has been associated with poor prognostic characteristics.

AIM

Our objective was to determine the frequency of BRAFV600E mutation in PTC tumor tissues from the period 1960-2007 and to correlate it with clinicopathological parameters.

SUBJECTS AND METHODS

DNAs were extracted from 242 PTCs, 23 sporadic medullary carcinomas, one anaplastic carcinoma and 6 poorly differentiated carcinomas. The presence of BRAFV600E mutation was determined using single strand conformation polymorphism method and verified by direct sequencing.

RESULTS

BRAFV600E mutation was detected in 81 of 242 PTCs (33.5%), in one of 6 poorly differentiated carcinomas (16.7%) and in anaplastic carcinoma. BRAFV600E mutation was much less frequent in the follicular variant compared to classical variant and mixed follicular- classical variant of PTCs (p=0.001). BRAFV600E mutation was significantly associated with presence of nodal metastasis (p=0.029), more advanced TNM stage (p=0.014) and recurrence of disease (p=0.008). The mutation correlated with a higher age at diagnosis (p=0.049) and with a greater tumor size (p=0.041). Multivariate analysis confirmed these findings. The prevalence of BRAFV600E mutation before 1986 was significantly lower than after it (p=0.008).

CONCLUSIONS

Our data suggest that BRAFV600E mutation is associated with high-risk clinicopathological characteristics of PTC and worse prognosis of patients. The frequency of the mutation significantly varied during the observed period but rather because of the different age distribution of patients in particular periods than as a consequence of Chernobyl accident.

Abstract C241: Fine needle aspiration biopsy as a new method for monitoring of tumor microenvironment after treatment with polymeric drugs

Introduction: Cancer therapy seems to be, according to the latest findings, a combination of direct tumor cytotoxicity and the reaction of host immune system, which should become activated to successfully treat neoplastic disease. Monitoring time-dependent changes in composition of tumor infiltrating population of immunocompetent cells during the treatment could help to optimize therapeutic protocols and dosage.

Water soluble polymeric conjugates based on N-(2-hydroxypropyl)-methacrylamide (HPMA) bearing anticancer drug doxorubicin bound through amide (DOX-HPMA-AM)) or hydrazone bond (DOX-HPMA-HYD) minimize unwanted side effects of conventional chemotherapy and thus enables much more aggressive treatment with very promising results. To analyze changes in tumor microenvironment during the treatment with such polymeric conjugates, we have used fine needle aspiration biopsy (FNAB). This is a commonly used clinical method to acquire samples from the body with minimal influence to tissues. It seems to be an ideal tool for gaining cell material repeatedly from one experimental animal during the treatment with simultaneous possibility to evaluate tumor growth and efficacy of used therapeutic protocol.

Materials and Methods: C57BL/6 mice bearing EL4 T-lymphoma stably expressing Enhanced Green Fluorescent Protein (EL4-EGFP+) were treated with DOX-HPMA-AM, DOX-HPMA-HYD or free doxorubicin. FNAB was applied to isolate samples from EL4-EGFP+ tumors from mice treated with different drugs. All samples were stained with specific fluorescently labeled antibodies (CD3, CD4, CD8, CD45), analyzed by flow cytometry, and verified with the samples obtained from the tumor by excision. Also the tumor progression and survival of mice after FNAB were observed regular time distances.

Results: The data obtained by FNAB or standard excision are comparable. Moreover, cell populations gained by FNAB method are more properly separated and contaminated with less debris. FNAB influences neither the tumor progression nor survival of experimental animals.

Our data show that the number of tumor-infiltrating CD4 and CD8 lymphocytes increasing rapidly on third day after treatment with DOX-HPMA-AM and DOX-HPMA-HYD, while this treatment leads to complete recovery of neoplasma in all experimental animals. Contrary to this, free doxorubicin has no influence on composition of immunocompetent cells in tumor microenvironment and also no animal was able to recover from neoplastic disease. This fact suggests that both cytotoxic and immunomobilizing effect participate on tumor regression after treatment with HPMA conjugates.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C241.

Occult thyroid carcinoma

Some medical definitions remain the same for many years, others change due to the progress in the diagnostic tools, which are able to distinguish markers and symptoms until then undetectable. Occult thyroid carcinoma is a general term indicating clinically different situations, whereas the incidentally detected papillary thyroid microcarcinoma is the most important from the clinical point of view. It is fundamental, for therapeutic management, to determine biological parameters which would define a small group of papillary thyroid microcarcinomas with aggressive biological behaviour. The most promising genetic and molecular markers for papillary thyroid carcinoma risk stratification are discussed in this review. Preoperative evaluation of these markers, obtained through analysis of ultrasonography-guided fine needle biopsy specimens of papillary thyroid microcarcinoma, could be very valuable in guiding treatment of this type of cancer.

Human Papilloma Virus (HPV) in head and neck region: review of literature

The evidence that human papillomavirus infection is related to head and neck squamous cell carcinoma is supported by molecular and epidemiological data. The definition of a distinct subset of head and neck squamous cell carcinoma, independent of the traditional risk factors and with different clinical presentation and outcome, has led to increasing interest in human papillomavirus infection. This review summarizes current knowledge regarding human papillomavirus biology, oncogenic mechanisms, risk factors for transmission, clinical significance and prophylactic strategies.

Galectin-7: will the lectin's activity establish clinical correlations in head and neck squamous cell and basal cell carcinomas?

The human lectin galectin-7 (Gal-7; p53-induced gene-1) has anti- and pro-malignant features in different in vitro models. We tried to clarify relation of its expression to cellular and clinical parameters in head and neck squamous and basal cell carcinomas. Using a non-cross-reactive antibody, immunohistochemical staining in squamous cell epithelia (epidermis, epithelium of oropharynx and larynx) (n = 57), squamous cell carcinomas (n = 47) and lymph node metastases (n = 25), as well as basal cell carcinomas (n = 10) were studied. This monitoring was flanked by processing to assess the level of differentiation (cytokeratins 10 and 14), proliferation (Ki67) and basal lamina formation (collagen IV). The results were correlated with clinical and pathological findings (grading, TNM-staging, extracapsular spread, angio- and lymphangioinvasion, perineural invasion, recurrence and survival). Gal-7 resides in all layers of epithelia with cytoplasmic and nuclear localization in normal specimens. Basal cell carcinomas were devoid of the Gal-7 respective signal. Squamous cell carcinomas were positive, presenting different staining profiles. Intense staining was predominantly found in squamous cell cancers with high degrees of differentiation and keratinization. Fittingly, poor level of differentiation (P = 0.0009), absence of keratinization (P = 0.0105) and significant discontinuity or absence of collagen IV expression in the peritumoral basal lamina (P = 0.0024) was found in Gal-7-negative tumors. Gal-7 presence was not related to gender, primary tumor site, T-stage, N-stage, clinical stage, extracapsular spread, angio- and lymphangioinvasion, perineural spread or treatment outcome at a statistically significant level. Immunohistochemical analysis revealed a positive correlation for differentiation and keratinization to Gal-7 presence in squamous cell carcinomas. Absence of Gal-7 expression was detected in basal cell carcinomas. These clinical data delineate Gal-7 influence on differentiation in vivo, without evidence for a role in dissemination reported for lymphoma.

Regulatory T cells and their prognostic value for patients with squamous cell carcinoma of the head and neck

Regulatory T cells (Treg) are important regulators of anti-cancer immune responses, and an increase in Treg frequency was observed in the blood of cancer patients. Blood samples from 112 patients with head and neck squamous cell carcinoma antigen (HNSCC) were obtained at the time of tumour diagnosis, and lymphocyte subpopulations (CD3⁺; CD3⁻CD16⁺CD56⁺; CD4⁺; CD8⁺; CD19⁺; CD4⁺CD45RA⁺) with emphasis on Treg counts (CD3⁺CD4⁺CD25⁺), complete blood count and tumour markers (squamous cell carcinoma [SCC]; CEA; α-1-antitrypsin [AAT]; Cyfra 21–1; C-reactive protein [CRP]) were analysed. The data were grouped according to TNM classification, and their significance for the course of the disease at an interval of 1 year after the end of the therapy was determined. The percentage of CD8⁺ cells increased and the CD/D8 ratio decreased with tumour grade. The ratio of B lymphocytes decreased in patients with locoregional metastases (11.25%versus 9.22%). Treg (15.2%) and CD4⁺ cells (45.3%) increased, while NK cells (11.8%) decreased in HNSCC patients compared to controls (9.0%, 38.1% and 15.8%, respectively). The data obtained at time of diagnosis were used to assess the significance of tumour markers (SCC, Cyfra 21–1 and AAT) for evaluation of prognosis. The erythrocyte counts (4.64 × 10¹²/l versus 4.45 × 10¹²/l) and haemoglobin levels (14.58 g/dl versus 14.05 g/dl) decreased, while Treg counts (8.91%versus 15.70%) increased in patients with early recurrence. Our results show that examination of these parameters could be helpful for prognostication in HNSCC patients and aid improvement of treatment strategy.

[Galectins in squamous cell carcinomas of the head and neck cancers]

Cancers of head and neck represents about 5% of all tumors. 80 to 90% of these tumors are constituted of squamous cell carcinomas. Despite a rapid progress in diagnostics and therapy the overall 5-year survival of this type of cancer is among the lowest of the major cancer types. This unfavourable situation needs the extensive research to found new markers to better characterize biological behavior of tumors as a rational background for more sophisticated therapeutic modalities. Among the most promising markers are endogenous lectins called galectins and their ligands. Especially galectin-1, -3 and -7 play a key role in pathology of squamous cell carcinomas.

Helicobacter pylori in tonsillar and adenoid tissue and its possible role in oropharyngeal carcinogenesis

Helicobacter pylori is a well-known gastric pathogen. It plays a major role in the pathogenesis of chronic gastritis, duodenal and gastric ulcers, adenocarcinoma and gastric lymphoma. HP infection is one of the most common bacterial infections worldwide. Recently, the oral cavity was proposed as an extragastric reservoir of HP infection. HP was detected by culture and PCR in both dental plaque and saliva. It is supposed that HP infection can cause the same immunological changes in the oropharyngeal mucosa as in gastric mucosa and can also contribute to the progression of oropharyngeal diseases. HP can induce production of different cytokines and regulatory molecules, which are suggested to play a role in carcinogenesis of the oropharynx. Only a few studies have explored the presence of HP in tonsillar and adenoid tissue, where MALT is present similar to the gastric mucosa. The results of these studies were inconsistent. The question of persistence of HP in tonsillar and adenoid tissue and its role in the pathogenesis of oropharyngeal diseases still remains unclear. In this review, recent findings about oral HP are considered. Possibilities of diagnostics of HP in oral specimens are discussed.

Complicated decisionmaking in indications for auditory brainstem implant (ABI) in a patient with neurofibromatosis 2

A case of an accidental finding of neurofibromatosis 2 in a practically asymptomatic patient is described. Various therapeutic modalities, including restoration of hearing after vestibular schwannoma surgery with an auditory brainstem implant (ABI), are considered.

Early detection of cancer: ideas for a debate

Even if the overall number of cancer is increasing, the mortality has started to decrease in the Western World. The role of early detection in this decrease is a matter of debate. To assess its impact on mortality it is important to distinguish between diagnosis of cancer in symptomatic patients, and early detection in asymptomatic individuals who may self-refer or who may be offered ad hoc or systematic screening. The policies for early detection and screening vary greatly between European countries, despite many similarities in their cancer burden, and this partly reflects the uncertainties surrounding asymptomatic testing for cancer. A Task Force of European expert, held in Azzate (VA), Italy, established to address these issues, acknowledged the need for more research in the field of individual risk assessment since general statistics are more and more perceived as inadequate to design personal early detection plans. The group also recognised that combinations of early detection and screening will enforce the effectiveness of new treatments in curbing mortality curves, although policies will vary with different cancers.

[Sentinel lymph node biopsy in oral and oropharyngeal carcinomas]

BACKGROUND

The aim of our study was to assess feasibility and accuracy of sentinel lymph node biopsy in patients with head and neck squamous cell carcinoma with clinically N0 neck.

METHODS AND RESULTS

The sentinel lymph node was localised preoperatively by lymphoscintigraphy and intraoperatively by hand-held gamma probe after peritumoral injection of a Tc99m-labeled colloidal human serum albumin. The histology of the sentinel lymph node was compared with the histology of the nodes of the elective neck dissection performed in all patients. 27 patients with oral and oropharyngeal carcinomas accessible to injection in local anaesthesia were enrolled into a prospective trial between July 1993 and December 2005. The sentinel lymph node was localised by preoperative lymphoscintigraphy in 26 of 27 patients. Sentinel lymph node was identified perioperatively by hand-held gamma probe in all 28 necks of 27 patients. Occult metastases were found in 4 sentinel lymph nodes in 4 cases. In one case (3.6 %) the result of sentinel lymph node biopsy was false negative. The sentinel lymph node biopsy correctly predicted the positivity and negativity of the neck in 27 of 28 cases (96.4 %).

CONCLUSIONS

Sentinel lymph node biopsy in patients with oral and oropharyngeal carcinomas is feasible and seems to accurately predict the status of the regional lymph nodes.

Magnetic resonance imaging of the rat brain after epileptic seizures--preliminary results

The magnetic resonance imaging (MRI) of the rat brain after the epilepsy seizures has been performed. As a first step, the model of the kainic acid (KA) induced seizures has been conducted to examine the possibilities of magnetic resonance imaging system kept in disposition. Seven Wistar albino rats, weighing about 300 g, were used in this study. We administered six of them with intraperitoneal injection of 10 mg/kg of KA. The control animal received corresponding volume of the saline. Every animal was examined under systemic anaesthesia induced by an intraperitoneal injection of thiopental sodium approximately 15 minutes before scanning. Diffusion-weighted imaging (DWI) has been used to acquire the coronary scans of the rat brain. The progress of hyper intense signal at the cerebral cortex and amygdale has been observed. Marked asymmetry of the signal intensity between hemispheres has been discovered. Subsequently the experimental model of audiogenic epilepsy will be conducted.

HPV and other risk factors of oral cavity/oropharyngeal cancer in the Czech Republic

OBJECTIVE

An association between high-risk human papillomavirus (HR HPV) infection and a risk of development of a subgroup of head and neck cancers has been proposed recently. The main risk factors of oral and oropharyngal cancer observed in our population are smoking and alcohol consumption. The incidence of oral/oropharyngeal tumours in the Czech Republic is relatively high and there are no data available about the prevalence of HPV DNA presence in these tumours.

MATERIALS AND METHODS

Eighty patients with a primary oropharyngeal cancer were enrolled. The presence of HPV DNA has been evaluated by polymerase chain reaction in 68 cases from which the tumour tissue and demographical and clinical data were available. The typing of HPV was performed by nucleotide DNA sequencing.

RESULTS

The HPV DNA was detected in 51.5% of samples tested. Among the HPV DNA positive tumours, 80% contained HPV16. In the analysed group there were 54 men and 14 women. The prevalence of HPV DNA was lower in oral (25%) than in oropharyngeal (57%) tumours, and higher in never smokers (100%) and never drinkers (68.8%). HPV DNA presence was not related to gender, age, number of lifetime sexual partners or practice of oral-genital sex, size of tumour or presence of regional metastases.

CONCLUSIONS

The difference in the prevalence of HPV DNA positive tumours between cases of oral cavity and oropharyngeal carcinoma exposed and not exposed to tobacco or alcohol support the theory that HPV DNA positive tumours form an aetiologically distinct subgroup of head and neck tumours.

Long-lasting changes in the density of nitrergic neurons following kainic acid administration and chronic hypoxia

Using histochemical analysis (NADPH-diaphorase) we have investigated the influence of intraperitoneal administration of kainic acid (KA), hypoxia and combination of both these factors on neurons of the hippocampus and on the primary auditory cortex (PAC) in male rats of the Wistar strain. Kainic acid was administered to 18-day-old animals, which were exposed to long-lasting repeated hypoxia from the 2nd till the 17th day of age in a hypobaric chamber (for 8 hours a day). At the age of 1 year, the animals were transcardially perfused with 4 % paraformaldehyde under deep thiopental anesthesia. Cryostate sections were stained to identify NADPH-diaphorase positive neurons that were then quantified in CA1 and CA3 areas of the hippocampus, in the dentate gyrus and in the PAC. Both, hypoxia and KA lowered the number of NADPH-diaphorase positive neurons in the hilus, dorsal and ventral blades of the dentate gyrus, CA1 and CA3 areas of the hippocampus. On the contrary, KA given to the hypoxic animals increased the number of NADPH-diaphorase positive neurons in the dorsal blade of the dentate gyrus and PAC.

Detection of new diagnostic markers in pathology by focus on growth-regulatory endogenous lectins. The case study of galectin-7 in squamous epithelia

Lectins represent one of pivotal regulators of the cell proliferation The potential of galectin-7 as a new prognostic marker was studied in normal and transformed squamous epithelia of both ectodermal (epidermis, cornea vs. trichoepithelioma, basal and squamous cell carcinoma) and endodermal (vocal fold epithelium vs. carcinoma) origin. Studies on the cultured cells were also performed. Expression of galectin-7 seems to be connected to the process of stratification, no matter of origin of epithelium. Its expression is significantly reduced in malignant cells, thus galectin-7 might be a differentiation marker of epithelial malignancies.

Epidermal growth factor receptor--its expression and copy numbers of EGFR gene in patients with head and neck squamous cell carcinomas

Signaling pathways activated by epidermal growth factor receptor (EGFR) are pathogenetically involved in the development of head and neck squamous cell carcinomas (HNSCC). A monoclonal antibody against the EGFR protein blocking the receptor activity (cetuximab - Erbitux - C225) is now available for therapeutic applications. The mechanisms of EGFR protein overexpression are poorly understood. Regulatory pathways, EGFR gene structural changes or its amplification may be involved. The aim of the study was to evaluate expression of the EGFR protein in patients with HNSCC, to identify EGFR gene copy numbers, and to find out whether the protein overexpression is associated with the EGFR gene amplification. In the case of a pathogenetical link of the EGFR gene amplification and the protein overexpression it would be useful to employ both diagnostic approaches to identify patients eligible for cetuximab therapy. We investigated 33 patients with HNSCC. The expression of EGFR protein was evaluated by immunohistochemistry, copy numbers of EGFR gene and the numbers of chromosome 7 centromeric signals were investigated by fluorescence in situ hybridization on interphasic nuclei (I-FISH). Histological sections from formalin fixed and paraffin embedded tissues were used. We observed three types of EGFR protein expression (homogeneous 3+ membrane positivity in 13 patients; membrane positivity varying from 1+ to 3+ in 12 patients; a strong membrane positivity at the periphery of the tumor cell clusters in 5 patients). In two cases the results were difficult to interpret. In one case single tumor cells only were positive. Numerical changes of chromosome 7 were present in 23 patients. We found the EGFR gene amplification in seven patients. The tumor cells with amplification of the EGFR gene were generally infrequent and were localized in small clusters, or they were randomly dispersed between the tumor cell population without the gene amplification. We did not find any correlation between the EGFR gene amplification and the EGFR protein overexpression. Thus, amplification of the EGFR gene is not pathogenetically involved in the EGFR protein overexpression. From the diagnostic aspect a standardized immunohistochemical assessment of the EGFR protein expression appears sufficient for detection of the EGFR status. Criteria for cetuximab treatment in patients with HNSCC may differ from those already used for patients with colorectal carcinomas and should take different patterns of the EGFR protein overexpression into consideration.

Long-lasting changes in the density of nitrergic neurons following kainic acid administration and chronic hypoxia

Using histochemical analysis (NADPH-diaphorase) we have investigated the influence of intraperitoneal administration of kainic acid (KA), hypoxia and combination of both these factors on neurons of the hippocampus and on the primary auditory cortex (PAC) in male rats of the Wistar strain. Kainic acid was administered to 18-day-old animals, which were exposed to long-lasting repeated hypoxia from the 2nd till the 17th day of age in a hypobaric chamber (for 8 hours a day). At the age of 1 year, the animals were transcardially perfused with 4 % paraformaldehyde under deep thiopental anesthesia. Cryostate sections were stained to identify NADPH-diaphorase positive neurons that were then quantified in CA1 and CA3 areas of the hippocampus, in the dentate gyrus and in the PAC. Both, hypoxia and KA lowered the number of NADPH-diaphorase positive neurons in the hilus, dorsal and ventral blades of the dentate gyrus, CA1 and CA3 areas of the hippocampus. On the contrary, KA given to the hypoxic animals increased the number of NADPH-diaphorase positive neurons in the dorsal blade of the dentate gyrus and PAC.

[Treatment of benign stenoses of the large airways at the Faculty Hospital Praha-Motol during 1998-2003]

The authors present diagnostic and therapeutical results in the group of 80 patients with benign stenoses of large airways, who were hospitalized at the TRN ward (Department of TB and respiratory disorders) of the Faculty hospital Motol in Prague between the years 1998-2003. 62 patients sufferred from stenoses in cosequence of their tracheal intubation or tracheostomy. In 18 cases the stenoses resulted from other disorders or pathological condidtions (Wegener's granulomatosis, status post lung transplantation, etc.) 38 patients were sent for surgery. Up until the date of the assessment (September 2003), 8 of them had had a relaps of the condiditon. 6 operated subjects had their restenosis corected using bronchological methods, 2 subjects had to undergo reoperation, which is 5.2% of the total number of the operated subjects. The remaining 42 patients were treated using the interventional bronchological methods (electrocauther, laser, stents) which proved curative in 35 patients, i.e 44% of the whole group. In 7 inoperable patients the above methods failed, 6 of them having a permanent tracheostomy and one female-patient exited 2 days after an incomplete recanalization. In the subgroup of 18 patients with other than postintubation stenoses, stent operations were the most frequent (12 times), 4 patients were cured using other methods of interventional bronchology, and resection of the stenosis was indicated in two cases. Up until the date of the assessment, 65 subjects had survived and 15 exited. 5 of them died 3-14 months (median of 4 months) following the surgical procedure of other disorders than of the respiratory airways stenoses. 10 unoperated patients, with a single exception, also died due to other causes than the tracheobroncheal lesions (the survival rate median was 9 months). Following the initial freeing of the airways, the authors call for considering a surgical therapeutical option in each case. Provided the surgical approach was contraindicated, the interventional bronchological methods would replace it appropriately.

Serum levels of IGF-I, HGF, TGFbeta1, bFGF and VEGF in thyroid gland tumors

IGF-I, HGF, TGFbeta1, bFGF and VEGF are involved in the pathogenesis of thyroid gland tumors and their growth. We decided to find whether changes in the production of these cytokines by thyroid tumor cells are reflected by changes of their peripheral blood. Using ELISA kits, we measured the concentrations of growth factors in the peripheral blood serum in 28 patients with thyroid gland tumors (14 adenomas, 14 papillary carcinomas) and compared these concentrations with those in healthy people. We found significantly lower serum levels of IGF-I in patients with thyroid adenoma compared to the healthy population. Serum levels of HGF and bFGF were significantly higher in patients with thyroid adenoma and papillary carcinoma compared with those in healthy subjects. Serum concentrations of TGFbeta1 and VEGF were not significantly different in any groups of investigated subjects. Changes in the production of these cytokines by thyroid gland tumor cells are reflected in their peripheral blood levels, but these levels also depend on a number of other physiological and pathological processes in the organism. However, significant differences of HGF and bFGF serum levels can be explained by their very high production by thyroid tumor cells and by their strong effect on the follicular and endothelial cell proliferation.

Our surgical experience with large vestibular schwannomas

Our aim is to remove large vestibular schwannomas (VS) radically with minimal morbidity. Usually, these tumours cannot not be treated by irradiation. In the years 1997-2003, 69 VS were operated in the Department of Otorhinolaryngology, Head and Neck Surgery of the First Medical Faculty in Prague, Czech Republic. Prevailing majority of these tumours were of the 4th grade (House classification), compressing the brainstem. Six patients in the group suffered from neurofibromatosis 2, in five cases the patients were indicated for neurosurgery due to rapid tumour growth after previous irradiation. All tumours were radically removed using a retromastoid osteoplastic and translab approach with an intraoperative nerve monitoring. Good function of the facial nerve was achieved in 90%. The nerve had to be resutured in 4 cases with consequent satisfactory results, cross anatomosis was not performed. Hearing function was preserved in 8% of patients only. In 6 patients with neurofibromatosis 2, the auditory brainstem implant (ABI) was used to preserve hearing. This study demonstrates that a radical removal of large vestibular schwannomas is possible using a minimally invasive surgical technique and peroperative nerve monitoring with a good impact on quality of life. Auditory brainstem implants bring a new chance of hearing after tumour removal in patients with NF2.

Changes in the number of nitrergic neurons following kainic acid administration and repeated long-term hypoxia

Using histochemical analysis (NADPH-diaphorase) we have been investigating the influence of intraperitoneal administration of kainic acid (KA), hypoxia and combination of both these factors on neurons of the hippocampus and on the primary auditory cortex (PAC) in male rats of the Wistar strain. Kainic acid was administered to 18-day-old animals, which were exposed to long-lasting repeated hypoxia from the 2nd till the 17th day of age in a hypobaric chamber (for 8 h a day). At the age of 22 or 90 days, the animals were transcardially perfused with 4 % paraformaldehyde under deep thiopental anesthesia. Cryostate sections were stained to identify NADPH-diaphorase positive neurons that were then quantified in the hippocampus, in the dentate gyrus and in the PAC. In 22-day-old animals both hypoxia and KA increased the number of NADPH-diaphorase positive neurons in the hilus, CA1, CA3 areas of the hippocampus and in the PAC. On the contrary, KA given to hypoxic animals lowered the number of NADPH-diaphorase positive neurons in the dentate gyrus. In 90-day-old animals, hypoxia and KA given to both normoxic and hypoxic animals lowered the number of NADPH-diaphorase positive neurons in some areas of the central nervous system.