Rami Katra

Pilot study: Association between Helicobacter pylori in adenoid hyperplasia and reflux episodes detected by multiple intraluminal impedance in children

OBJECTIVES The aim of this pilot study was to investigate an association between laryngopharyngeal reflux detected by combined multiple intraluminal impedance and pH monitoring and Helicobacter pylori in adenoid hyperplasia detected with real time polymerase chain reaction (PCR). METHODS The study group consisted of 30 children (median age 5.34 years) with extraesophageal symptoms of gastroesophageal reflux disease with adenoid hyperplasia. All children underwent adenoidectomy with subsequent PCR detection of H. pylori DNA in the tissue and multiple intraluminal impedance and pH monitoring. The most proximal impedance sensor was located 1cm caudal to the entrance of the oesophagus. RESULTS We found significant differences in the number of reflux episodes among patients with PCR positivity (median 35) and negativity (median 0) of H. pylori (p-value of Mann-Whitney U-test 0.0056). Patients with PCR positivity of H. pylori had significantly more reflux episodes reaching the upper oesophageal sphincter (p-value of Mann-Whitney U-test 0.023). The absence of reflux episode was the only independent factor for PCR negativity of H. pylori in the multiple logistic regression model. CONCLUSIONS These results support the hypothesis that reflux episodes reaching the upper oesophageal sphincter may play an important role in the transmission of H. pylori into lymphoid tissue of the nasopharynx and thus may contribute to adenoid hyperplasia in children.

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

Helicobacter pylori has been recently detected in the oral cavity and oropharynx. However, the role it plays in oral and oropharyngeal pathogenesis remains unclear. The virulence of H. pylori strains can be distinguished according to the virulence factors genes carried. Our research has been focused on realtime PCR analysis of cagA and vacA genes of H. pylori strains in tonsils and tonsillar squamous cell cancer and their comparison with H. pylori strains obtained from the gastric mucosa of the same patients. Urea breath test (UBT) test was used to detect a gastric H. pylori infection in 20 patients with previously proven H. pylori in the oropharynx. Genotyping of H. pylori in gastric biopsies was performed in patients with positive gastric infection. Out of 20 patients positive for oropharyngeal H. pylori, 8 were positive for concurrent gastric H. pylori infection. In 6 of them gastric biopsies were obtained. Comparison of oropharyngeal and stomach H. pylori genotypes showed important differences. Four of 6 patients had different H. pylori strains in the oropharynx and stomach. The differences were found in cagA gene as well as in vacA gene. The finding of oral presence of H. pylori without concurrent stomach infection was confirmed using UBT. The results show that more than one H. pylori strain can be present in oropharynx and stomach in the same patient. The oropharyngeal infection seems to be independent to the gastric infection.

Bacterial infection complications in children with cochlear implants in the Czech Republic

OBJECTIVE Studies describing wound infections after cochlear implantation are rare. Meticulous operative techniques and sufficient surgical skill can help to avoid severe postoperative complications. Minor complications such as seromas, superficial wound infections, skin emphysema, and swelling can all be successfully treated using conservative methods. Serious problems, however, could be caused by Pseudomonas aeruginosa and Staphylococcus aureus infections. STUDY DESIGN Retrospective case series. SETTING Pediatric cochlear implant center in the Czech Republic. RESULTS In our cohort of 360 children operated on between 1994 and 2009, there were no major surgical complications. However, there were four serious wound infections, two of which resulted in explantation of the device. Two patients with a well-bordered abscess formation were successfully treated with antibiotics and drainage. Explantation was required in another two children with refractory P. aeruginosa infection. Despite favorable sensitivity to a number of antibiotics, intravenous and intensive local treatment failed. After explantation, the operative sites healed immediately. Both children were successfully implanted contralaterally 6 months later. Detailed bacteriological tests from different parts of the device were performed. CONCLUSION The consequences of explantation were discussed in our cochlear implant center. Confirmed by the microbiological results and reports in the scientific literature, it seems preferable to cut the electrode near the cochlear array and leave it inside the cochlea in order to use the same ear for reimplantation at a later date.

Thyroid carcinoma surgery in children and adolescents – 15 years experience surgery of pediatric thyroid carcinoma

OBJECTIVES The purpose of this study is to evaluate the characteristics of thyroid gland surgery focusing on malignancies at the pediatric age with the main concern on treatment results and complications in extensive primary treatment. METHODS The records of all patients 18 years and younger with surgically treated thyroid diseases in the Prague Hospital, Motol, between 1991 and 2006 were retrospectively reviewed. RESULTS Thyroid surgery was performed on 148 pediatric patients (including 56 carcinomas). The youngest patient involved in the study was seven years old, the oldest patient 18 years old (mean 13.7 years). Most frequent histological cancer type was PTC (42 cases, 75%). Follicular cancer was diagnosed in five cases (8.9%) and medullar cancer in nine cases (16.1%). A prophylactic thyroidectomy was performed in three cases (5.4%) without clinical signs of thyroid tumor with diagnosed RET gene mutation. CONCLUSIONS We consider total thyroidectomy with subsequent radioiodine ablation and TSH suppression as the basic approach in the treatment protocol of pediatric WDTC. The observed 100% recurrence-free and overall survival together with a low incidence of postoperative complications strongly supports the idea of a total thyroidectomy with selective neck dissection in the treatment of metastases of WDTC and MTC.

Prevalence of Helicobacter pylori in adenotonsillar hypertrophy in children

Abstract Conclusion: Our results encourage the notion that the pharynx could be an extragastric reservoir of Helicobacter pylori (HP). The study confirmed the presence of HP in adenotonsillar tissue in children. It could have importance in the pathophysiology of upper respiratory diseases. However, its precise role in these processes remains unclear and requires further studies. Objective: A prospective study was carried out to evaluate the presence of HP in tonsillar and adenoid tissue in children. The study focused on real-time PCR analyzing CagA and VacA genotypes of HP strains. Methods: A total of 37 consecutive pediatric patients with adenotonsillar hypertrophy indicated for surgery were observed in a prospective study. Adenoidectomy and/or tonsillectomy was performed in each patient; 49 specimens were taken, 32 from adenoids and 17 from tonsils. The presence of HP and its genotype were tested in all samples by real-time PCR analysis. Results: Of 49 samples analyzed, 48 were positive for the presence of HP (98%), so only 1 sample was negative. While the genotype VacAs1bm2 was definitely dominant in adenoid tissue, wider distribution was observed in tonsillar tissue. Cag+ strains represented one-fifth of all samples (21%).

Polymorphisms in selected DNA repair genes and cell cycle regulating genes involved in the risk of papillary thyroid carcinoma.

BACKGROUND Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. In addition to causal somatic mutations in the BRAF gene and RET/PTC rearrangements, the contribution of single nucleotide polymorphisms (SNPs) in low-penetrance genes in the development of PTC has been proposed. METHODS Four SNPs in the XRCC1 (Arg399Gln, Arg280His, Arg194Trp and T-77C) and one SNP from each of three other genes participating in DNA repair pathways and/or cell cycle regulation (ATM Asp1853Asn, TP53 Arg72Pro, CDKN1B Val109Gly) were selected. The allelic and genotypic distributions of these variants as well as haplotypes of the XRCC1 were examined in 583 individuals comprising well-characterized cohorts of 209 PTC patients and 374 healthy volunteers. Correlations of polymorphism with clinical-pathological data and mutation status were performed. RESULTS XRCC1 T-77C polymorphism affects the genetic susceptibility for PTC development in men, the specific combination of XRCC1 haplotypes correlates with RET/PTC incidence, CDKN1B Val109Gly significantly influences the risk of developing PTC regardless of gender and in PTC cases, selected genotypes of TP53 Arg72Pro and ATM Asp1853Asn were significantly associated with monitored tumour characteristics. CONCLUSION It seems that SNPs in studied regulating genes contribute to the development of PTC and modify the tumour behaviour or characteristics.

A novel RET/PTC variant detected in a pediatric patient with papillary thyroid cancer without ionization history

Papillary thyroid carcinoma (PTC) is the most frequent type of thyroid cancer. Its development is often caused by the formation of RET/PTC fused genes. RET/PTC1 is the most prevalent form, where exon 1 of CCDC6 gene is fused with the intracellular portion of RET protooncogene starting with exon 12. We have discovered a novel RET/PTC1 variant which we have named RET/PTC1ex9 in metastatic PTC of 8-year-old boy. RET/PTC1ex9 detection was performed by real-time polymerase chain reaction with melting curve analysis and subsequent Sanger and next-generation sequencing. A fusion of exon 1 of CCDC6 with exon 9 of extracellular domain of RET followed by exon 12 of RET was revealed. This is the first RET/PTC variant among PTC cases that contain the extracellular part of RET. This observation could be probably explained by incorrect splicing of RET due to the somatic 32-bp deletion in exon-intron 11 boundary of RET.