Clinical predictors of polyps recurring in patients with chronic rhinosinusitis and nasal polyps: a systematic review and meta-analysis.

BACKGROUND: Identification of perioperative risk factors for recurrent nasal polyps (RNPs) is important for selection of further treatment and determination of appropriate follow-up period. However, the relative prognostic significance of these risk factors has not been investigated. METHODOLOGY: We compared the nasal symptoms, endoscopic polyp and Lund-Mackey computed tomography scores, and the laboratory and pathological findings of RNP and non-RNP patients. The risk of bias was assessed using the Newcastle-Ottawa scale. RESULTS: Patients with poor nasal symptom scores and olfactory dysfunctions and high Lund-Mackey computed tomography scores were at higher risk of postoperative RNPs, as were those with allergic conditions and elevated tissue and serum eosinophil levels. The tissue neutrophil counts/percentages were significantly lower in the RNP than the other group. The tissue eosinophil level was of higher diagnostic utility than the serum eosinophil level. The RNP diagnostic odds ratio afforded by the tissue eosinophil count or percentage was 54.1247. The area under the receiver operating characteristic curve was 0.936. The sensitivity and specificity were 0.8809 and 0.8834, respectively. CONCLUSION: The tissue eosinophil level reliably predicts RNP after endoscopic sinus surgery.

Bacterial strain changes during chronic otitis media surgery.

OBJECTIVE: Cultures obtained from pre-operative middle-ear swabs from patients with chronic otitis media have traditionally been used to guide antibiotic selection. This study investigated changes in the bacterial strains of the middle ear during chronic otitis media surgery. METHODS: Pre-operative bacterial cultures of otorrhoea, and peri-operative cultures of the granulation tissue in either the middle ear or mastoid cavity, were obtained. Post-operative cultures were selectively obtained when otorrhoea developed after surgery. RESULTS: Bacterial growth was observed in 45.5 per cent of pre-operative cultures, 13.5 per cent of peri-operative cultures and 4.5 per cent of post-operative cultures. Methicillin-resistant Staphylococcus aureus was identified as the most common bacteria in all pre-operative (32.4 per cent), peri-operative (52.4 per cent) and post-operative (71.4 per cent) tests, and the percentage of Methicillin-resistant S aureus increased from the pre- to the post-operative period. CONCLUSION: The bacterial culture results for post-operative otorrhoea showed low agreement with those for pre-operative or peri-operative culture, and strain re-identification was required.

Localized insulin amyloidosis with use of concentrated insulin: a potential complication.

BACKGROUND: Insulin-derived amyloidosis is a rare form of amyloidosis composed of insulin fibrils. The pH and concentration of insulin are known to influence the conformational state of the insulin hormone, with an increasing concentration favouring a more complex conformation. Concentrated insulin delivers a large amount of insulin to a localized area, raising the possibility of inducing conformational changes, forming insulin fibrils and leading to localized insulin amyloidosis. CASE REPORT: A middle-aged woman with long history of Type 2 diabetes mellitus, treated with concentrated human insulin (U-500 insulin) presented with nodular lesions at the site of her daily insulin injections. A punch biopsy of the nodules showed skin with dermal amyloidosis staining favourably with Congo Red stain. The amyloid tumours were resected and areas positive for Congo Red stain were sent for liquid chromatography tandem mass spectrometry, which showed a peptide profile consistent with amyloid insulin. CONCLUSION: Concentrated insulin was first introduced in 1952, however, it is only over the last two decades that it has been used increasingly, in congruence with the increasing incidence of obesity and diabetes mellitus seen in the USA. Only a few cases of insulin amyloidosis at the site of injection have been described in literature. With the increase in the use of insulin, this complication seems to be occurring more frequently. This is the first case report of a person with diabetes mellitus who developed localized insulin amyloidosis with the use of concentrated insulin, and points towards a potential complication of developing insulin amyloidosis with the use of concentrated insulin.

Korean mistletoe lectin regulates self-renewal of placenta-derived mesenchymal stem cells via autophagic mechanisms.

OBJECTIVES: The balance between survival and death is a key point for regulation of physiology of stem cells. Recently, applications of natural products to enhance efficiencies in culturing and differentiation of stem cells are increasing. Korean mistletoe lectin (Viscum album L. var. coloratum agglutinin, VCA) has been known to be toxic to some cancer cells, but it is still unclear whether VCA has a cytotoxic or indeed a proliferative effect on mesenchymal stem cells (MSCs). Here, we have compared effects of VCA in naïve placenta-derived stem cells (PDSCs), immortalized PDSCs and cancer cells (HepG2), and analysed their mechanisms. MATERIALS AND METHODS: MTT assay was performed to analyse effects of VCA on naïve PDSCs, immortalized PDSCs and HepG2. FACS, ROS, caspase-3 assay, western blotting and immunofluorescence were performed to detect signalling events involved in self-renewal of the above cell types. RESULTS: VCA had cancer cell-specific toxicity to HepG2 cells even with low concentrations of VCA (1-5 pg/ml), toxicity was observed to immortalized PDSCs and HepG2s, while proliferation of naïve PDSCs was significantly increased (P < 0.05). ROS production by VCA treatment in naïve PDSCs was significantly lower compared to controls (P < 0.05). Furthermore, autophagy was activated in naïve PDSCs treated with VCA through increase in type II LC3 and decrease in phosphorylated mTOR. CONCLUSIONS: VCA can promote MSC proliferation through an activated autophagic mechanism.

Chromosomal aberrations in neuroblastoma cell lines identified by cross species color banding and chromosome painting.

We have studied cytogenetic rearrangements in karyotypes of five neuroblastoma cell lines [SK-N-AS, SK-N-SH, SH-SY5Y, SK-N-MC, SMS-KCNR] by G-banding, cross species color banding (RxFISH), and fluorescence in situ hybridization (FISH) with chromosome painting probes. Each neuroblastoma cell line had unique modal karyotypic characteristics and showed a variable number of numerical and structural clonal cytogenetic aberrations. The number of rearranged chromosomes in SK-N-AS, SK-N-SH, SH-SY5Y, SK-N-MC, and SMS-KCNR was 11, 3, 7, 14 (tetraploid, 20-21), and 6, respectively. The origins of abnormal chromosomes were effectively analyzed by RxFISH and FISH with multiple chromosome painting probes. The chromosomal origin of the homogeneously staining region in SH-SY5Y was identified as coamplification of chromosome bands 2p13 and 2p24 by chromosome microdissection and FISH. The non-random rearrangements of chromosomes were determined on 1p34 approximately p36, 6q16 approximately q21, 8q24, 9q34, 11q13 approximately q23, 16q23 approximately q24, 17q21, and 22q31. These results may provide useful information for further molecular characterization of neuroblastoma.

Directed evolution of a novel N-carbamylase/D-hydantoinase fusion enzyme for functional expression with enhanced stability.

Bifunctional enzymes find a wide application as a monitoring facility and a potential biocatalyst in molecular biology and biotechnology. Recombination of natural enzymes to a bifunctional fusion offers valuable tools, but the functional and structural instability of artificial fusion enzymes remains to be solved. Based on structural traits of microbial D-hydantoinase, we attempted to construct a bifunctional N-carbamylase/D-hydantoinase fusion enzyme that would be useful for the synthesis of nonnatural D-amino acids in a concerted fashion. The bifunctional ability of D-hydantoinase, as a fusion partner, was noticeable, but the resulting fusion enzyme was subjected to serious proteolysis in vivo, as generally encountered in the expression of large the multidomain polypeptide in E. coli. In an effort to improve the structural instability imposed by artificial linear fusion, directed evolution of the fusion enzyme was performed using DNA shuffling with a consensus primer to maintain a crucial domain for the enzyme activity. The evolved fusion enzyme, F11, was selected after repeated rounds, and this enzyme was found to show sixfold increased performance in the production of D-amino acid compared with the parent fusion enzyme, which was mainly due to the enhanced structural stability of the evolved fusion enzyme. This result is an example showing that directed evolution of the linearly fused polypeptide may broaden the opportunity to generate a fusion enzyme with greater potential.