Objective assessment of the effect of surgery on limb function after medial femoral condyle free flap harvest: biomechanical parameters.

The aim of this study was to evaluate the influence of medial femoral condyle (MFC) free flap harvest on donor site muscle strength and kinematic parameters of gait. The study included 30 patients treated for head and neck squamous cell carcinoma who underwent reconstruction with an MFC free flap. In each case, the donor site was the left thigh. A dynamometer was used to measure muscle strength, in isokinetic bilateral mode and with concentric contraction for the extension/flexion knee pattern, at 18 months postoperative. In addition, kinematic data were obtained and evaluated. On statistical analysis, no significant difference in muscle strength of the quadriceps muscle was found between the left involved and right uninvolved lower extremities (P = 0.124). Also, when comparing hamstring strength, no statistically significant difference was found between the left involved and right uninvolved sides (P = 0.210). Moreover, spatiotemporal gait parameters did not differ significantly between the involved and uninvolved legs (all P > 0.05), and no differences in kinematic or kinetic parameters were observed. This study reports the effects of MFC free flap harvest on the knee muscle strength and locomotion of patients. For most biomechanical parameters investigated, there was no effect (positive or negative).

[Comparison of DNA adducts between oral, pharyngeal and larynx cancer]. / Porównanie zachowania sie poziomu adduktów kancerogen: DNA w rakach jamy ustnej, gardla i krtani.

The results concerning examination of DNA adducts in oral (23 patients), pharyngeal (23 patients) and larynx cancer (10 patients) subjects are presented. DNA adduct levels were compared in respect to anatomical structure (primary tumour location), number of cigarettes smoked, TNM stage, and age of patients. DNA was isolated from removed tissue (tumour and non-tumour surrounding tissue) using detergent/phenol extraction. 32P-postlabelling assay including nuclease P1-enhancement modification was applied. Aromatic DNA adducts were found in all studied tissues. Total DNA adduct levels (tumour and non-tumour tissues) was lowest in larynx cancer, higher in oral cancer and highest in pharyngeal cancer. There were no influence of age into formation of DNA adducts. The higher level of DNA adducts was found in tumour tissue of oral cancer in the group of smokers with metastasis into lymph nodes.

Analysis of aromatic DNA adducts in laryngeal biopsies.

Epidemiological studies have confirmed the correlation between tobacco smoking, environmental pollution and the incidence of cancers of the respiratory tract. The occurrence of laryngeal cancer in Poland is relatively high compared to other European countries. Since 1969 the mortality related to larynx cancer appears to be increasing. Tobacco smoke contains an abundance of such carcinogenic compounds as polycyclic aromatic hydrocarbons (PAH), aromatic amines and N-nitrosoamines, which can react with DNA and form adducts. We analyzed aromatic DNA adducts in laryngeal tissues from patients with primary laryngeal, which was confirmed histopathologically to be squamous cell carcinoma. The group consisted of 33 patients (5 women and 28 men). Total laryngectomy was performed in patients. A detergentphenol method was used for DNA isolation. Aromatic DNA adducts were analyzed by a 32P-postlabelling technique with butanol extraction and high performance liquid chromatography. The presence of aromatic DNA adducts was demonstrated in all tissues. Large interindividual differences of DNA adduct levels were seen in each tissue studied. There was a higher mean level of DNA adducts in interarytenoid area non-tumors (51.96/10(8) +/- 91.71 NN) than in non-tumor tissue elsewhere (46.91/10(8) +/- 46.36 NN) and tumor tissue (43.52/10(8) +/- 45.88 NN). Adduct levels were correlated with age, sex, cigarette smoking and TNM stage.

Molecular and cellular alterations in tobacco smoke-associated larynx cancer.

Tumours of head and neck belong to the most frequent types of cancer world-wide. In Poland, mortality from larynx cancer among males has been continuously increasing during the last decades up to 8.4 deaths per 100,000 men in 1993, which exceeds epidemiological records from other countries. The aetiology of laryngeal cancer is strongly associated with exposure to carcinogens present in tobacco smoke. The review describes a sequence of molecular and cellular events from carcinogenic exposure, DNA adduct formation, detection of mutations in the p53 gene, loss of heterozygosity (LOH) in chromosomal loci encoding the p53 and p16 genes, and loss of control of the cell cycle. The section concerning DNA adducts includes a discussion of the role of such confounders as exogenous exposure, the age and sex of the subject, and disease progression. The significance of genetic factors as individual risk determinants is discussed in relation to bleomycin-induced chromosome instability and in connection with the occurrence of defects in genes encoding detoxifying enzymes. The question concerning the substantial difference between men and women in larynx cancer morbidity and mortality remains open, even when the significantly higher adduct formation in male DNA compared with female material was taken into account. Preliminary experiments suggest a role of the frequently observed loss of the Y-chromosome.

Carcinogen: DNA adducts in tobacco smoke-associated cancer of the upper respiratory tract.

Mortality connected with tobacco smoke-associated laryngeal cancer in Poland markedly exceeds the relevant epidemiological data from other European countries. The main groups of genotoxic agents considered as potential carcinogens present in tobacco smoke are polycyclic aromatic hydrocarbons, aromatic amines, N-nitrosoamines and reactive oxygen species. Aromatic DNA adducts, N7-alkylated guanosines and oxidative DNA damage derived from tobacco smoke exposure were detected in laryngeal and oral (tumour and non-tumour) biopsies, and white blood cells of cancer subjects. Further, DNA lesions were analysed to estimate the significance of such confounders as intensity of smoking, subject's sex, age, topography of larynx, cancer staging and genetic factor. The number of cigarettes smoked per day was found to be the main determinant of an individual's DNA adduct level. The occurrence of DNA lesions was established as a reliable marker of former exposure to tobacco smoke genotoxicants. On the other hand, a comparison of DNA lesion levels in various regions of larynx indicates limited usefulness of DNA adduct analysis as an estimate of cancer risk. For a better risk estimation one has to take into account DNA lesions in proto-oncogenes and tumour suppressor genes and the efficacy of DNA repair. Altogether, DNA adducts formation and removal has to be considered as a single stage in the multistep carcinogenesis.

[Sex-dependence of larynx susceptibility to tobacco smoke carcinogens. The role of androgen hormones]. / Plec a podatnosc krtani na dzialanie czynników kancerogennych obecnych w dymie tytoniowym. Rola hormonów androgennych.

According to epidemiological data concerning laryngeal cancer there is almost ninefold higher morbidity in male population than in females. The aim of this study was to analyse on molecular level the genotoxic effects arising under the same exposure to tobacco smoke in males and females. In biopsies received from laryngectomy material we determined levels of aromatic and alkylated DNA adducts in tumours and in adjacent non-tumour tissue. It was established that levels of DNA adducts found in male DNA samples exceeded those in female DNA samples 1.5-3.8 times, which was recognised as a molecular evidence for epidemiological differences. Next, testosterone and sex hormones binding globulin (SHBG) were determined in male subjects blood serum. The levels of testosterone and SHBG very weakly correlated with DNA adduct levels even when subjects were separated into age groups. It is concluded that levels of testosterone and SHBG are not the proper markers of individual susceptibility to genotoxicity of tobacco smoke carcinogens.

Tobacco smoke-associated N7-alkylguanine in DNA of larynx tissue and leucocytes.

The presence of N7-alkylguanine adducts in DNA was analysed in a group of 46 patients with larynx tumours. All patients were subjected to laryngectomy and the tissues accessible for analysis by (32)P-post-labelling assay were larynx tumour, larynx non-tumour and peripheral blood leucocytes. N7-Alkylguanine adducts were detected in all the studied DNA samples. The average level of N7-alkylguanines was 26.2/10(7) nucleotides in tumour cells, 22.7/10(7) in non-tumour cells and 13.1/10(7) in blood leucocytes. There was significantly higher level of N7-alkylguanines in the larynx tissues in males than in females. The effect of tobacco smoking on DNA adduct levels was shown by an increase in the average levels of N7-alkylguanines in the subject groups classified according to their smoking habits. A moderate age-related increase in levels of N7-alkylguanine was demonstrated in larynx tumour tissue. The levels of N7-alkylguanine adducts in larynx cells were compared with that of aromatic DNA adducts. Pearson correlation coefficients (0.28 for tumour tissue and 0.30 for non-tumour tissue) indicate independent formation and removal of N7-alkylguanine and aromatic DNA adducts resulting from tobacco smoke exposure.

[Estimation of aromatic DNA adduct levels in laryngeal tumors in relation to cancer staging]. / Ocena poziomu aromatycznych adduktów DNA w tkankach krtani w róznych stopniach zaawansowania procesu nowotworowego.

Genotoxical agents as PAH, nitrosamines, aromatic amines located in tobacco smoke are responsible for disorders of structure and function of DNA chromosomes, proteins and also initiation of carcinogenesis. DNA adducts are recognized as measure of the biological effective dose of exposure to environmental genotoxicant. So far most studies on DNA adducts after human exposure to tobacco smoke have ben carried out on white blood cells, lungs and oral cavities tissue. The aim of this work was estimation of relationship between state of neoplastic disease (TNM system) and number of aromatic DNA adducts. The subject were 37 patients with primary larynx tumor. In every case histopathological investigation revealed squamous cell carcinoma. There were 33 total and 4 partial laryngectomies performed. From tumour and nontumour larynx tissue DNA was isolated. Analysis of DNA adducts was performed by the 32P-postlabelling method. The results were characterized by individual differentiation. The highest level of DNA adducts was found in larynx tumour cells. In case of strong smokers (30-40 cigarettes per day) the level of aromatic adducts was higher then in non- or ex-smokers. In both tissues (tumour and non-tumour) the highest level of aromatic adducts was in T3 stage, the lowes in cause of T2 stage. In tissues with T4 stage the level of DNA adducts was intermediate. One has been observed decrease tendency in level of DNA adducts which is connected with increase of TNM stage.

Aromatic DNA adducts in larynx biopsies and leukocytes.

Larynx cancer is strongly associated with tobacco smoking. The objective of this work was an analysis of aromatic DNA adducts in tumour and non-tumour larynx cells by means of the 32P-postlabelling method. Peripheral blood leukocytes were used as a reference tissue. The presence of aromatic DNA adducts was demonstrated in all the studied tissues obtained after surgery of larynx tumours. The highest level of DNA adducts was found in larynx tumour cells, followed by non-tumour larynx cells, which exceeded that found in leukocytes almost 2.5 times. Large interindividual differences were detected between subjects. The adduct level in tumour/non-tumour correlated only moderately. However a high correlation was found between the level of DNA adducts in larynx (tumour and non-tumour) cells and that in leukocytes.