Evaluation of swallowing function after intraoral soft tissue reconstruction with microvascular free flaps.

This study assessed swallowing function after tumour resection and reconstruction utilizing free vascularized flap closures in patients with oral cancer. Swallowing function was evaluated postoperatively in 23 patients (21 men and 2 women) who had undergone reconstruction with either a lateral upper arm free flap (LUFF, n=16) or a radial forearm free flap (RFFF, n=7). Videofluoroscopy was used to assess tongue mobility and abnormalities of swallowing function. All patients who underwent reconstruction with LUFF or RFFF free flaps had decreased tongue mobility, except for the tip of the tongue. Patients who underwent anterior or posterior resection had greater decreases in tongue mobility than those who underwent medial resection. Swallowing impairment was similar in patients with LUFFs and those with RFFFs. Anterior resection of the oral cavity had a significant negative effect on swallowing function. Silent aspiration occurred in five patients. In conclusion the resection site affected swallowing function, but the type of flap did not, in patients with oral carcinoma, who underwent tumour resection with reconstruction

Cytotoxicity of ingredients of various dental materials and related compounds in L2- and A549 cells.

Various ingredients of dental materials and related compounds were tested for cytotoxicity in two alveolar epithelial cell lines (L2 and A549 cells). Release of lactate dehydrogenase (LDH) from cells was measured after incubation with the test substances for time intervals up to 48 h and expressed as percentage of total LDH content of lysed cells. Furthermore, the glutathione content of cells was determined in the nonmalignant L2 cells. Additionally, cell viability was assessed by microscopic examination. The highest cytotoxicity was observed with mercury compounds (methylmercuric chloride and mercury dichloride) in the range of 5-20 micromol/l. The composite components 2-hydroxyethylmethacrylate (HEMA) and triethleneglycoldimethacrylate (TEGDMA) showed time- and concentration-dependent effects of cytotoxicity at high concentrations (about 1-5 mmol/l). A time dependence for GSH decrease was mainly found for the composite components up to 12 h of cellular exposure. L2 cells were more sensitive to both mercury and composite compounds than A549 cells. Gold compounds (sodiumaurothiomalate and gold particles < 1.5 microm) did not produce any sign of toxic reactions. A time-dependent increased toxicity in pulmonary cell lines was found for the composite components HEMA and TEGDMA, but not for mercury and gold compounds.

Prevalence of H. pylori-infection in family members of H. pylori positive and its influence on the reinfection rate after successful eradication therapy: a two-year follow-up.

INTRODUCTION: Living conditions (e. g. domestic crowding) may influence the infection rate. Some studies suggested that the reappearance of H. pylori in H. pylori positive patients after successful eradication therapy might be a result of transmission by H. pylori positive spouses. Therefore this study has been performed to evaluate the effect of the H. pylori status of family members on the reinfection rate of H. pylori positive patients after successful eradication therapy. METHODS: 108 H. pylori positive patients (64 male, 44 female, aged 48.7 years, range 18-76 years) who presented with dyspeptic symptoms for upper GI-endoscopy have been included into this study. H. pylori status has been defined by culture and/or histology, rapid urease test and serology. For eradication therapy patients received omeprazole 20 mg bd, clarithromycine 250 mg bd and metronidazole 400 mg bd. H. pylori status was controlled by (13)C-urea breath test 28 days (n = 96), 6 (n = 35), 12 (n = 28) and 24 months (n = 25) after eradication therapy. Additionally H. pylori status of 170 family members (82 spouses, 68 children, 20 siblings/parents, aged 3-83 years) was defined by (13)C-urea breath test (n = 167), upper GI-endoscopy (n = 2) or serology (n = 1). RESULTS: The eradication rate was 98 % (94/96). H. pylori prevalence in all family members was 40 % (56 % in spouses, 20 % in children). No reinfection has been found in successful eradicated patients within the two-years follow-up. DISCUSSION: These results suggest that reinfection is not dependent on the H. pylori prevalence in family members and that H. pylori reinfection after successful eradication therapy is an unlikely event.

Age and Helicobacter pylori decrease gastric mucosal surface hydrophobicity independently.

BACKGROUND: Gastric mucosal surface hydrophobicity (GMSH) is an essential component of the mucosal defence system that is decreased by Helicobacter pylori and non-steroidal anti-inflammatory drugs (NSAIDs). Gastric ulcers occur predominantly in elderly subjects, and may thus reflect diminished mucosal resistance. AIMS: To investigate whether aging decreases GMSH. PATIENTS: One hundred and twenty patients without peptic ulcer disease were divided into three age groups: I (41 years or below); II (41-64 years); and III (65 years or above). METHODS: Biopsy specimens were taken from the antrum, corpus, and cardia for histology (Sydney system), urease testing for H pylori, and for contact angle measurement of GMSH with a goniometer. The presence of specific H pylori antibodies was checked by immunoblotting. RESULTS: Fifty two patients (43%) were infected, and 68 were uninfected with H pylori. GMSH at all biopsy sites was lower in H pylori infected subjects (p=0.0001), but also decreased with age independently of infection status (p=0.0001). The most notable decrease in GMSH occurred between age groups I and II in those with, and between age groups II and III in those without, H pylori infection. GMSH was greater in antral than in corpus mucosa in both infected (p=0.0001) and uninfected patients (p=0.0003). CONCLUSIONS: A physiological decrease in GMSH with aging may contribute to the risk of ulcer development in the elderly, and may act synergistically with H pylori and/or NSAIDs on gastric mucosal defence.

Prevalence of Helicobacter pylori resistance to several antimicrobial agents in a region of Germany.

To evaluate the prevalence of resistance among Helicobacter pylori in Germany, the minimum inhibitory concentrations of amoxicillin, tetracycline, clarithromycin, and metronidazole were determined by means of the E test, for 271 Helicobacter pylori isolates cultured from biopsies taken during routine endoscopies in 1996 and 1997. The prevalence of metronidazole resistance was 32.1%, with resistance found more frequently in women (38.5%) than in men (24.4%). Clarithromycin resistance was rare (3.3%). Eight of nine strains resistant to clarithromycin were also resistant to metronidazole. Resistance to either metronidazole or clarithromycin was significantly (P=0.022) higher in patients with duodenal ulcer. No strain was found to be resistant to amoxicillin or tetracycline.

Helicobacter pylori and proteolytic activity.

Protease activity of 10 different H. pylori strains, purified marker proteases and protease-positive reference bacteria (Klebsiella ozaenae, Serratia marcescens) were tested against bovine haemoglobin, porcine mucin, bovine serum albumin, gelatin and casein as substrates. After incubation in development buffer and subsequent staining with Coomassie blue, protease activity bands were demonstrated as transparent spots after polyacrylamide gel electrophoresis (PAGE) on gels with incorporated substrate. Presence of protease activity was investigated in a wide pH range (pH 2.0-9.0). Although marker proteases (0.15-0.2 microgram per slot) as well as protease-positive bacteria (2-30 micrograms per slot) clearly showed proteolytic activity in gels containing 0.1-0.2% protein mL-1, no proteolytic activity was demonstrated in any of the H. pylori strains tested. This finding indicates that H. pylori does not possess significant protease activity, as this would have been detected by this sensitive method.

Adhesion of Helicobacter pylori and Escherichia coli to human and bovine surface mucus cells in vitro.

Helicobacter pylori shows in vivo a specific affinity for epithelial surface mucus cells (SMC) of the human stomach. We studied the in vitro adhesion of five different H. pylori strains and one non-pathogenic Escherichia coli-strain to (a) human antral SMC, obtained during gastroscopy; (b) human tumour SMC, from a carcinoma cell line (CRL 1739 AGS); and (c) bovine SMC, obtained from the abomasum. SMC of different origin were characterized by means of electron microscopy and immunohistochemistry, and showed similar main features: all cells showed intra-cellular structures like zymogens and PAS-positive mucin granules. HSMC were antibody-positive against epithelial cell markers. All five H. pylori strains adhered to human SMC (HSMC) and tumour SMC (TSMC). Only one strain additionally adhered to bovine SMC (BSMC). No adhesion to any of these cells was observed with E. coli. Adhesion in vitro is characterized by a close membrane-to-membrane association between H. pylori and the target cells. This phenomenon suggests a specific receptor-ligand interaction.