Tomasz Krecicki

Laryngeal Manifestations of Gastroesophageal Reflux Disease in Children

Although the association between gastroesophageal reflux disease (GERD) and laryngeal disorders in adults is well established there is still a lack of information concerning the true extent of the laryngeal complications of GERD in children. The aim of this study was to determine the laryngeal status of children with diagnosed GERD. We sought to identify the initial appearance of their larynges and then to determine the clinical response to antireflux therapy. GERD was recognized in 90/100 children examined. Using 24-h pH monitoring we found that most of the patients experienced episodes of gastroesophageal reflux during the daytime when they were in an upright position. The hallmark of GERD affecting the larynx in our group was posterior laryngitis, which is characterized by erythema of the mucous membrane overlying the arytenoid cartilages and the posterior mucosal wall of the glottis. The findings regarding the effectiveness of therapy were that, in children with severe laryngeal alterations, voice quality improved significantly after 12 weeks of antireflux treatment ( p < 0.001) and laryngeal status was significantly better after 6 weeks of treatment ( p < 0.001). This study provides evidence that gastroesophageal reflux in children is the underlying cause of inflammatory and morphological lesions, and that antireflux treatment is effective in reducing or eliminating these lesions.

Diabetes and Cancer: a Review of Current Knowledge

Diabetes mellitus (DM), one of the most common life-threatening illnesses worldwide, is a group of metabolic diseases, characterized by sustained hyperglycemia. The global prevalence of diabetes mellitus among adults reached 387 millions in 2014 and is still rising. It is suggested there is a strong association between diabetes mellitus (especially type 2 diabetes mellitus) and carcinogenesis. The possible biological links between diabetes mellitus and cancer comprise hyperinsulinemia, hyperglycemia and fat-induced chronic inflammation. Although, the strongest association refers to pancreas and liver, there are many other organs involved in carcinogenesis in diabetic patients including breast, endometrium, bladder and kidney.Recent studies suggest that there is also association between cancer incidence and anti-diabetic medications. It was observed that some medications decrease the risk of carcinogenesis and some increase that risk. The majority of studies concern metformin, a drug of choice in type 2 diabetes mellitus, and its anti-neoplastic and tumor-suppressing activity. The positive effect of metformin was found in numerous researches investigating breast, pancreas, liver, colon, ovaries and prostate tumors.Because a variety of studies have suggested that diabetes mellitus and cancer are frequently coexisting diseases, recently published studies try to explain the influence of diabetes mellitus and anti-diabetic medications on carcinogenesis in different organs.We present the review of the latest studies investigating the association between both diabetes mellitus and anti-diabetic medications and cancer incidence and prognosis.Particularly we highlight the problem of concomitant head and neck cancers in diabetics, rarely analysed and often omitted in studies.

Epidermal differentiation complex (locus 1q21) gene expression in head and neck cancer and normal mucosa.

Epidermal differentiation complex (EDC) comprises a number of genes associated with human skin diseases including psoriasis, atopic dermatitis and hyperkeratosis. These genes have also been linked to numerous cancers, among them skin, gastric, colorectal, lung, ovarian and renal carcinomas. The involvement of EDC components encoding S100 proteins, small proline-rich proteins (SPRRs) and other genes in the tumorigenesis of head and neck squamous cell cancer (HNSCC) has been previously suggested. The aim of the study was to systematically analyze the expression of EDC components on the transcript level in HNSCC. Tissue specimens from 93 patients with HNC of oral cavity and 87 samples from adjacent or distant grossly normal oral mucosawere analyzed. 48 samples (24 tumor and 24 corresponding surrounding tissue) were hybridized to Affymetrix GeneChip Human 1.0 ST Arrays. For validation by quantitative real-time PCR (QPCR) the total RNA from all180 samples collected in the study was analyzed with Real-Time PCR system and fluorescent amplicon specific-probes. Additional set of samples from 14 patients with laryngeal carcinoma previously obtained by HG-U133 Plus 2.0 microarray was also included in the analyses. The expression of analyzed EDC genes was heterogeneous. Two transcripts (S100A1 and S100A4) were significantly down-regulated in oral cancer when compared to normal mucosa (0.69 and 0.36-fold change, respectively), showing an opposite pattern of expression to the remaining S100 genes. Significant up-regulation in tumors was found for S100A11, S100A7, LCE3D, S100A3 and S100A2 genes. The increased expression of S100A7 was subsequently validated by QPCR, confirming significant differences. The remaining EDC genes, including all encoding SPRR molecules, did not show any differences between oral cancer and normal mucosa. The observed differences were also assessed in the independent set of laryngeal cancer samples, confirming the role of S100A3 and LCE3D transcripts in HNC. In HNC of oral cavity only one family of EDC genes (S100 proteins) showed significant cancer-related differences. A number of other transcripts which showed altered expression in HNC require further validation.

Inactivation of the cyclin-dependent kinase inhibitor 2A (CDKN2A) gene in squamous cell carcinoma of the larynx

Defects in the system controlling the cell cycle can lead an increased proliferation of cancer cells. The aim of our study was to analyze the relationship between genetic changes leading to inactivation of the CDKN2A gene and subsequent alteration of protein expression in squamous cell cancer of the larynx (SCCL) in connection with the clinical and histopathological course of the disease. Analysis was carried out on DNA isolated from the blood and primary larynx cancer cells of 62 patients. To investigate loss of heterozygosity (LOH), PCR fragment analysis was applied. The size and quantity of fluorescent PCR products were evaluated in an automated sequencer. Specific chemical methylation with sodium bisulfite in a sequential PCR reaction (MSP) was applied to analyze promoter methylation. Cancer tissue sections served to determine the level of protein expression with immunohistochemical (IHC) staining and commercial antibodies. LOH at the CDKN2A locus was observed in 55.35% of the informative cases. Aberrant methylation was found in 37.5% and a decreased level of protein expression observed in 45% of all informative cases. Whenever P16 expression was decreased, LOH and promoter hypermethylation at CDKN2A were observed with a frequency of 73.33% and 80.95%, respectively (Fishers test, P < 0.005). Sixty‐nine percent of G3 tumors had at least one genetic alteration at CDKN2A, compared with 40.9% of G1 cancers. The results indicate that CDKN2A inactivation played a significant role in the development of squamous cell carcinoma of the larynx.

Self-Test Web-Based Pure-Tone Audiometry: Validity Evaluation and Measurement Error Analysis

Background Potential methods of application of self-administered Web-based pure-tone audiometry conducted at home on a PC with a sound card and ordinary headphones depend on the value of measurement error in such tests. Objective The aim of this research was to determine the measurement error of the hearing threshold determined in the way described above and to identify and analyze factors influencing its value. Methods The evaluation of the hearing threshold was made in three series: (1) tests on a clinical audiometer, (2) self-tests done on a specially calibrated computer under the supervision of an audiologist, and (3) self-tests conducted at home. The research was carried out on the group of 51 participants selected from patients of an audiology outpatient clinic. From the group of 51 patients examined in the first two series, the third series was self-administered at home by 37 subjects (73%). Results The average difference between the value of the hearing threshold determined in series 1 and in series 2 was -1.54dB with standard deviation of 7.88dB and a Pearson correlation coefficient of .90. Between the first and third series, these values were -1.35dB±10.66dB and .84, respectively. In series 3, the standard deviation was most influenced by the error connected with the procedure of hearing threshold identification (6.64dB), calibration error (6.19dB), and additionally at the frequency of 250Hz by frequency nonlinearity error (7.28dB). Conclusions The obtained results confirm the possibility of applying Web-based pure-tone audiometry in screening tests. In the future, modifications of the method leading to the decrease in measurement error can broaden the scope of Web-based pure-tone audiometry application.

Lactoferrin inhibits the growth of nasal polyp fibroblasts

The aim of this study was to evaluate the effects of lactoferrin (LF) on the growth of fibroblasts derived from nasal polyps. We showed that the proliferation of fibroblasts was inhibited in a dose-dependent manner by both native and recombinant LF. The greatest inhibition of proliferation was caused by human milk-derived, iron-saturated LF. The inhibition of fibroblast proliferation was not species specific because bovine LF also was active. The interaction between LFs and a putative cell receptor did not depend on the sugar composition of the glycan moiety of the LF molecule because lactoferrins of different origins were active and the addition of monosaccharides to the cultures did not block proliferation. However, the treatment of fibroblasts with sodium chlorate (an inhibitor of glycosaminoglycan sulfation) or the addition of heparin abolished the inhibitory effect of LF, suggesting that LF binds heparan sulfate-containing proteoglycans. The significance of LF in nasal excretions in controlling polyp formation is discussed.

Expression of c-myc oncoprotein in laryngeal squamous cell carcinoma.

Objective c-myc seems to play a pivotal role in normal growth and development as well in cellular transformation and carcinogenesis. Overexpression of the c-myc oncogene has been observed in many hematopoetic and solid tumors. The role of c-myc protein in squamous cell carcinoma of the head and neck in general and laryngeal squamous cell carcinomas (LSCCs) in particular is far from clear. The aim of this study was to evaluate the relations between the level of c-myc protein in LSCCs and the clinicopathological data of patients, DNA ploidy and the SG2M phase index (PI). Material and Methods The c-myc protein level was evaluated immunohistochemically in tumor specimens from 50 patients with LSCC. The DNA index and SG2M PI were determined by means of flow cytometry. Results We found c-myc protein in 34 (68%) tumors. Expression of c-myc protein was demonstrated to be frequent in non-metastatic cases (p=0.016). There was no association between c-myc protein level and age, primary tumor size, histological grading or type of cancer. In 13 (26%) cases we observed DNA aneuploid tumors. The mean value of the SG2M PI was 22.5%. Expression of c-myc protein was not related to SG2M PI or DNA ploidy. Conclusions We have shown that c-myc oncoprotein may be involved in the genesis of LSCC. Our findings suggest that the detectability of c-myc protein is associated with a lower metastatic potential. The c-myc oncogene is probably not as important in laryngeal cancers compared to other cancers. Further investigations must be performed to establish the value of predicting nodal metastases in LSCC.

Expression of collagenase-1 (MMP-1), collagenase-3 (MMP-13) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in laryngeal squamous cell carcinomas

Matrix metalloproteinases (MMPs) that have a proteolytic activity against the components of extracellular matrix (ECM) play an important role in the invasive and metastatic spread of tumors. The role of MMPs and tissue inhibitors of MMPs (TIMPs) in laryngeal squamous cell carcinoma (LSCC) has not been elucidated sufficiently. The aim of the present study was to evaluate the correlation between the expression of collagenase-1 (MMP-1), collagenase-3 (MMP-13) and TIMP-1, as well as the clinicopathological features of LSCCs. The expression of collagenases and TIMP-1 was examined immunohistochemically in 50 cases of surgically obtained specimens of primary LSCCs. Analyses indicated that LSCC cells as well as stromal cells expressed MMP-1, MMP-13 and TIMP-1 immunostaining. Overexpression of TIMP-1 occurred more frequently in non-metastasizing cases ( P =0.009). TIMP-1 and MMP-1 staining correlated significantly with the histologic type of LSCC. The keratinizing type of carcinomas exhibited higher TIMP-1 protein expression than the nonkeratinizing variety ( P =0.01). TIMP-1 staining was associated with the grade of differentiation, since it was found predominantly in well and moderately differentiated carcinomas ( P =0.04). The findings confirm that expression of analyzed MMPs and TIMP-1 is characteristic of LSCC and that these enzymes contribute to the progression of tumors. TIMP-1 upregulation might exhibit lower metastatic potential in LSCCs and is linked rather with an early stage of tumor progression. It seems also that TIMP-1 expression is dependent on the grade of differentiation.

Hearing Tests on Mobile Devices: Evaluation of the Reference Sound Level by Means of Biological Calibration.

Background Hearing tests carried out in home setting by means of mobile devices require previous calibration of the reference sound level. Mobile devices with bundled headphones create a possibility of applying the predefined level for a particular model as an alternative to calibrating each device separately. Objective The objective of this study was to determine the reference sound level for sets composed of a mobile device and bundled headphones. Methods Reference sound levels for Android-based mobile devices were determined using an open access mobile phone app by means of biological calibration, that is, in relation to the normal-hearing threshold. The examinations were conducted in 2 groups: an uncontrolled and a controlled one. In the uncontrolled group, the fully automated self-measurements were carried out in home conditions by 18- to 35-year-old subjects, without prior hearing problems, recruited online. Calibration was conducted as a preliminary step in preparation for further examination. In the controlled group, audiologist-assisted examinations were performed in a sound booth, on normal-hearing subjects verified through pure-tone audiometry, recruited offline from among the workers and patients of the clinic. In both the groups, the reference sound levels were determined on a subject’s mobile device using the Bekesy audiometry. The reference sound levels were compared between the groups. Intramodel and intermodel analyses were carried out as well. Results In the uncontrolled group, 8988 calibrations were conducted on 8620 different devices representing 2040 models. In the controlled group, 158 calibrations (test and retest) were conducted on 79 devices representing 50 models. Result analysis was performed for 10 most frequently used models in both the groups. The difference in reference sound levels between uncontrolled and controlled groups was 1.50 dB (SD 4.42). The mean SD of the reference sound level determined for devices within the same model was 4.03 dB (95% CI 3.93-4.11). Statistically significant differences were found across models. Conclusions Reference sound levels determined in the uncontrolled group are comparable to the values obtained in the controlled group. This validates the use of biological calibration in the uncontrolled group for determining the predefined reference sound level for new devices. Moreover, due to a relatively small deviation of the reference sound level for devices of the same model, it is feasible to conduct hearing screening on devices calibrated with the predefined reference sound level.

Expression patterns of cyclin E, cyclin A and CDC25 phosphatases in laryngeal carcinogenesis

The aim of the research was to evaluate the expression levels of cyclin E/A and CDC25A/B during laryngeal carcinogenesis. The expression was demonstrated using immunohistochemistry in 46 cases of laryngeal cancer (LSCC), 23 epithelial dysplasias (ED) and 21 samples of normal mucosa (NM). The mean labeling indices (LI) for cyclin E in LSCC, ED and NM were 10.6, 4.9 and 0%; for cyclin A 27.2, 17.5 and 7%; for CDC25A 73.9, 53 and 32% and for CDC25B 36.5, 25.9 and 0%, respectively. A gradual increase in cyclin A and CDC25A expression levels from mild through moderate and severe dysplasia to in situ carcinoma were noted. Cyclin A LI significantly increased also from NM through ED to LSCC. Cyclin A and CDC25A LI significantly increased from NM to ED. Overexpression of cyclin A and CDC25A was significantly associated with proliferation among ED. Linear interdependency was detected in ED between the expression of CDC25A and cyclin A. Cyclin E and CDC25B overexpression occurs as a late event in neoplastic transformation. The progressive expression of proteins supports the multistep model of laryngealcarcinogenesis. The results indicate a possible role of cyclin A as a marker reflecting cell proliferation. The enhanced immunoexpression of cyclin A and CDC25A suggests the potential for malignant formation in preneoplastic lesions.