Lipoteichoic acid from Staphylococcus aureus induced expression of MMP-9 in human middle ear epithelial cells.

OBJECTIVE: Change in matrix metalloproteinases (MMPs) and regulation of their tissue inhibitors of metalloproteinases (TIMPs) could play certain role in the pathogenesis of otitis media. This study was designed to evaluate the modulation of MMPs and TIMPs in middle ear epithelium by lipoteichoic acid (LTA) isolated from Staphylococcus aureus. METHODS: Human middle ear epithelial (HMEE) cells were treated with LTA. MMP activities were examined by PCR, ELISA and zymography, and levels of TIMPs were measured by PCR and ELISA. RESULTS: LTA isolated from S. aureus increased MMP-9 mRNA expression and secretion in HMEE cells, whereas no effect on the expressions of MMP-1, -2, -3, -7 and TIMP-1, -2 was observed. CONCLUSIONS: LTA increased the activity of MMP-9, not TIMPs in middle ear epithelia, suggesting that disturbed balance between MMP-9 and TIMPs could play an active role in LTA-induced otitis media.

Albumin-like protein is the major protein constituent of luminal fluid in the human endolymphatic sac.

The endolymphatic sac (ES) is an inner ear organ that is connected to the cochleo-vestibular system through the endolymphatic duct. The luminal fluid of the ES contains a much higher concentration of proteins than any other compartment of the inner ear. This high protein concentration likely contributes to inner ear fluid volume regulation by creating an osmotic gradient between the ES lumen and the interstitial fluid. We characterized the protein profile of the ES luminal fluid of patients (n = 11) with enlarged vestibular aqueducts (EVA) by proteomics. In addition, we investigated differences in the protein profiles between patients with recent hearing deterioration and patients without hearing deterioration. The mean total protein concentration of the luminal fluid was 554.7±94.6 mg/dl. A total of 58 out of 517 spots detected by 2-DE were analyzed by MALDI-TOF MS. The protein profile of the luminal fluid was different from the profile of plasma. Proteins identified from 29 of the spots were also present in the MARC-filtered human plasma; however, the proteins identified from the other 25 spots were not detected in the MARC-filtered human plasma. The most abundant protein in the luminal fluid was albumin-like proteins, but most of them were not detected in MARC-filtered human plasma. The concentration of albumin-like proteins was higher in samples from patients without recent hearing deterioration than in patients with recent hearing deterioration. Consequently, the protein of ES luminal fluid is likely to be originated from both the plasma and the inner ear and considering that inner ear fluid volumes increase abnormally in patients with EVA following recent hearing deterioration, it is tempting to speculate that albumin-like proteins may be involved in the regulation of inner ear fluid volume through creation of an osmotic gradient during pathological conditions such as endolymphatic hydrops.

Bacteriological findings and antimicrobial susceptibility in chronic sinusitis with nasal polyp.

CONCLUSIONS: We recommend amoxacillin/clavulanate, cephalosporins and macrolides rather than penicillin as the first-line drug in chronic sinusitis with nasal polyps. In cases where there is no improvement of symptoms, cultures should be taken from the middle meatus, followed by appropriate selection of second-line antibiotics according to the sensitivity test results. OBJECTIVE: To investigate the causative bacteria and the antimicrobial susceptibility in patients with chronic sinusitis and nasal polyps in Korea. MATERIALS AND METHODS: The bacteriology and antimicrobial susceptibility of maxillary sinus aspirates from 81 patients were evaluated. RESULTS: Aerobes were isolated from 58.0% of the cultures from the middle meatus and from 48.1% of those from the maxillary sinus. Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pneumoniae were the most prevalent aerobic pathogens. Anaerobes were isolated from 8.6% of the cultures from the middle meatus and from 18.5% of the cultures from the maxillary sinus. The predominant anaerobic organisms were Prevotella and Peptostreptococcus in adults but none of them were cultured in children. A high rate of concordance of the middle meatus and maxillary sinus was noted. Monomicrobial infection was most commonly observed. Ampicillin-resistant H. influenzae isolates were cultured in 46% of the cases. Penicillin resistance rates were 93% for Staph. aureus; 25% of Strep. pneumoniae were intermediate and 25% were resistant.