Aims: To purify and characterize an exo‐acting chitinolytic enzyme produced from a Gram‐negative bacterium Pseudomonas fluorescens JK‐0412.
Methods and Results: A chitinolytic bacterial strain that showed confluent growth on a minimal medium containing powder chitin as the sole carbon source was isolated and identified based on a 16S ribosomal DNA sequence analysis and named Ps. fluorescens JK‐0412. From the culture filtrates of this strain, a chito‐oligosaccharides‐degrading enzyme was purified to apparent homogeneity with a molecular mass of 50 kDa on SDS–PAGE gels. The kinetics, optimum pH and temperature, and substrate specificity of the purified enzyme (named as NagA) were determined.
Conclusions: An extracellular chitinolytic enzyme was purified from the Ps. fluorescens JK‐0412 and shown to be an exo‐type β‐N‐acetylglucosaminidase yielding GlcNAc as the final product from the natural chito‐oligosaccharides, (GlcNAc)n, n = 2–5.
Significance and Impact of the Study: As NagA is secreted extracellularly in the presence of colloidal chitin, Ps. fluorescens JK‐0412 can be recognized as a potent producer for industry‐level and cost‐effective production of chitinolytic enzyme. This enzyme appears to have potential applications as an efficient tool for the degradation of chitinous materials and industry‐level production of GlcNAc. To the best of our knowledge, this is the first report on an exo‐type chitinolytic enzyme of Pseudomonas species.
SUMMARY:The dorsal epidural blood patch is a commonly used management technique for spontaneous intracranial hypotension from a dural CSF leak, but it may be less efficacious for cervical or ventral leaks. We report the technique of placing an anterior cervical blood patch for a large cervical ventral leak. To our best knowledge, this approach has not been reported. In the appropriately selected patient, an anterior cervical epidural blood patch may be safely used.
ABBREVIATIONS:EBP ϭ epidural blood patch; IH ϭ intracranial hypotension; SIH ϭ spontaneous IH
Aim/Background: In stage IB non-small cell lung cancer (NSCLC), prognostic factor is not well known and administration of adjuvant treatment is controversial. The C-MET is known to be associated with the pathogenesis and progression of NSCLC. Our purpose was to evaluate the impact of clinicopathological characteristics and C-MET on recurrence free survival (RFS) and cancer-specific survival (CSS) in patients with stage IB NSCLC, undergoing surgical resection. Methods: From 2005 to 2013, 115 patients who underwent complete resection with pathological stage IB were enrolled. We retrospectively reviewed clinicopathological data and performed immunohistochemistry with anti-MET monoclonal antibody in tissue microarrays. RFS and CSS were evaluated in patients depending on clinicopathological factors and C-MET status. Results: The median age of 115 patients was 65 years (range: 32-82 years). The patients comprised of 78 men (68%) and 37 women (31%). The histological types were adenocarcinoma (n = 77), squamous cell carcinoma (n = 32), others (n = 6). Thirty four patients relapsed and twenty four died of cancer progression. On the univariate analysis, lymphovascular invasion (LVI) (P = .003) and C-MET overexpression (P = .014) were significantly associated with decreased RFS. Meanwhile, smoking (P = .029) and LVI (P = .040) were correlate with shortened CSS. C-MET overexpression (P = .130) were not associated with CSS. However, in larger tumor than median size (>3.5cm), C-MET overexpression (P = .039) had a relation with reduced CSS. In multivariate analysis, LVI (RFS: P = .017) and C-MET (RFS: P = 0.040) were negative independent prognostic factor for RFS, but not significant for CSS. Subgroup assessments according to LVI and C-MET co-positivity were performed with univariate and multivariate analyses. Co-presence of LVI and C-MET overexpression was a significant negative prognostic factor for CSS (P = .023) as well as RFS (P = .002) in resected stage IB NSCLC. Conclusions: Our data indicates that stage IB NSCLC patients with LVI and C-MET overexpression showed poor survival outcome and adjuvant chemotherapy should be strongly recommended for these patients, especially with co-presence of LVI and C-MET overexpression. Disclosure: All authors have declared no conflicts of interest.
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