A novel bleb-dependent polysaccharide export system in nitrogen-fixing Azotobacter vinelandii subjected to low nitrogen gas levels

The alginate biofilm-producing bacterium Azotobacter vinelandii aerobically fixes nitrogen by oxygensensitivenitrogenases. Here we investigated the bacterial response to nitrogen/oxygen gas mixtures. A. vinelandii cellswere cultured in nitrogen-free minimal media containing gas mixtures differing in their ratios of nitrogen and oxygen.The bacteria did not grow at oxygen concentrations >75 % but grew well in the presence of 5 % nitrogen/25 % oxygen.Growth of wild-type and alginate-deficient strains when cultured with 50 % oxygen did not differ substantially, indicatingthat alginate is not required for the protection of nitrogenases from oxygen damage. In response to decreasing nitrogenlevels, A. vinelandii produced greater amounts of alginate, accompanied by the formation of blebs on the cell surface. Theencystment of vegetative cells occurred in tandem with the release of blebs and the development of a multilayered exine.Immunoelectron microscopy using anti alginate-antibody revealed that the blebs contained alginate molecules. Bycontrast, alginate-deficient mutants could not form blebs. Taken together, our data provide evidence for a novel blebdependentpolysaccharide export system in A. vinelandii that is activated in response to low nitrogen gas levels. [IntMicrobiol 2013; 16(1):35-44

海外大学とのPBL型国際共修 : 地元企業と連携したグローバル教育実践

2021年度前期より、徳島大学高等教育研究センターでは、全学的なグローバル人材育成に着手し、「グローバル・パーソン集中プログラム（GRIP, Global Person Resource Intensive Program）」を開始した。GRIPのプログラムの１つとして、シンガポール国立大学の日本語履修学生達と約１ヶ月間のオンラインによるPBL型（問題解決型学習）の国際共修を行ったが、本稿ではこの国際共修プログラムを取り上げ、本学の学生たちが回答した振り返りシートの内容をKJ法で分析し、プロジェクトの効果検証を試みた。語学面以外でも幅広い側面での成長を学生たちが実感していることが確認でき、グローバル人材としての能力・資質を育む機会として一定の効果があったのではないかと考えられる

Identification of hypoxia-inducible factor 1 ancillary sequence and its function in vascular endothelial growth factor gene induction by hypoxia and nitric oxide.

Transcription of hypoxia-inducible genes is regulated by hypoxia response elements (HREs) located in either the promoter or enhancer regions. Analysis of these elements reveals the presence of one or more binding sites for hypoxia-inducible factor 1 (HIF-1). Hypoxia-inducible genes include vascular endothelial growth factor (VEGF), erythropoietin, and glycolytic enzyme genes. Site-directed mutational analysis of the VEGF gene promoter revealed that an HIF-1 binding site (HBS) and its downstream HIF-1 ancillary sequence (HAS) within the HRE are required as cis-elements for the transcriptional activation of VEGF by either hypoxia or nitric oxide (NO). The core sequences of the HBS and the HAS were determined as TACGTG and CAGGT, respectively. These elements form an imperfect inverted repeat, and the spacing between these motifs is crucial for activity of the promoter. Gel shift assays demonstrate that as yet unknown protein complexes constitutively bind to the HAS regardless of the presence of these stimuli in several cell lines, in contrast with hypoxia- or NO-induced activation of HIF-1 binding to the HBS. A common structure of the HRE, which consists of the HBS and the HAS, is seen among several hypoxia-inducible genes, suggesting the presence of a novel mechanism mediated by the HAS for the regulation of these genes

Efficacy of Corrected Rapid Turnover Protein Increment Index (CRII) for Early Detection of Improvement of Nutrition Status in Patients with Malnutrition

Serum prealbumin level is useful for assessment of changes in nutritional status but it is markedly affected by the inflammation. In this study, we examined the efficacy of the corrected rapid turnover protein increment index (CRII) for prealbumin, which is calculated as [prealbumin level/C-reactive protein (CRP) level on the assessment day]/[prealbumin level/CRP level on the day of starting nutritional care], for prediction of improvement of nutritional status in patients with malnutrition. The subjects were 50 hospitalized patients with low albuminemia, who were receiving nutritional care. Serum concentrations of albumin, prealbumin and CRP were measured every week for 5 weeks. We defined patients whose serum albumin level was elevated by more than 0.2 g/dl after 5 weeks as those showing improved nutritional status. There was a significant difference in the prealbumin level between improved and unimproved patients at 5 weeks after the start of nutritional support. On the other hand, the prealbumin CRII value showed a significant difference between the groups at 1 and 2 weeks after the start of nutritional support. In conclusion, assessment of prealbumin CRII is useful for early prediction of improved nutritional status in patients with malnutrition

Microfluidic Chemotaxis Platform for Differentiating the Roles of Soluble and Bound Amyloid-β on Microglial Accumulation

Progressive microglial accumulation at amyloid-β (Aβ) plaques is a well-established signature of the pathology of Alzheimer's disease, but how and why microglia accumulate in the vicinity of Aβ plaques is unknown. To understand the distinct roles of Aβ on microglial accumulation, we quantified microglial responses to week-long lasting gradients of soluble Aβ and patterns of surface-bound Aβ in microfluidic chemotaxis platforms. We found that human microglia chemotaxis in gradients of soluble Aβ42 was most effective at two distinct concentrations of 23 pg.mL−1 and 23 ng.mL−1 Aβ42 in monomers and oligomers. We uncovered that while the chemotaxis at higher Aβ concentrations was exclusively due to Aβ gradients, chemotaxis at lower concentrations was enhanced by Aβ-induced microglial production of MCP-1. Microglial migration was inhibited by surface-bound Aβ42 in oligomers and fibrils above 45 pg.mm−2. Better understanding of microglial migration can provide insights into the pathophysiology of senile plaques in AD

Scattered X-rays in Obscured Active Galactic Nuclei and their Implications for Geometrical Structure and Evolution

We construct a new sample of 32 obscured active galactic nuclei (AGNs) selected from the Second XMM-Newton Serendipitous Source Catalogue to investigate their multiwavelength properties in relation to the "scattering fraction", the ratio of the soft X-ray flux to the absorption-corrected direct emission. The sample covers a broad range of the scattering fraction (0.1%-10%). A quarter of the 32 AGNs have a very low scattering fraction (smaller than 0.5%), which suggests that they are buried in a geometrically thick torus with a very small opening angle. We investigate correlations between the scattering fraction and multiwavelength properties. We find that AGNs with a small scattering fraction tend to have low [O III]lambda5007/X-ray luminosity ratios. This result agrees with the expectation that the extent of the narrow-line region is small because of the small opening angle of the torus. There is no significant correlation between scattering fraction and far-infrared luminosity. This implies that a scale height of the torus is not primarily determined by starburst activity. We also compare scattering fraction with black hole mass or Eddington ratio and find a weak anti-correlation between the Eddington ratio and scattering fraction. This implies that more rapidly growing supermassive black holes tend to have thicker tori.Comment: 13 pages, 10 figures, accepted for publication in Ap

イデンセイ ニュウガン ニツイテ

Hereditary breast cancer and/or ovarian cancer （HBOC） has been closed up in Japan. But few were known about the disease. HBOC is known as a syndrome that causes breast and ovarian cancer at exceptionally high rate in patients who have genetic mutations in BRCA １ or ２. The population of the Genetic/familial high risk breast and/or ovarian cancer is not low rate even in Japan if compared with the Western population. Important thing is recognize the fact that HBOC is not rare in Japan and perform a screening detailed family history if the patient has family history. We can evaluate the risk by genetic test and offer the preventive strategies like an intensive screening with MRI, chemoprevention and prophylactic mastectomy before the occurrence of cancer for the carrier. Genetic counseling service by the authorized doctor and counselor has been started in our institute. Genetic screening of BRCA１/２ mutation can be taken in Tokushima University Hospital

Comprehensive Prospective Analysis of the Factors Contributing to Aspiration Pneumonia Following Endoscopic Submucosal Dissection in Patients with Early Gastric Neoplasms

Endoscopic submucosal dissection (ESD) has become the first-line treatment for early gastric neoplasms; however, a subset of patients treated by this method develop aspiration pneumonia. We conducted a comprehensive prospective analysis of the factors contributing to post-ESD aspiration pneumonia in early gastric neoplasms in this study, with special focus on whether pre-treatment oral care can prevent aspiration pneumonia. Sixty-one patients who underwent ESD for gastric neoplasms were randomly assigned to the oral care or control groups. ESD was performed under deep sedation. Of 60 patients whose data were available for analysis, 5 (8.3%) experienced pneumonia confirmed either by chest radiography or computed tomography. Although no difference in the rate of pneumonia was found between the control and oral care groups, the post-oral care bacteria count was significantly higher in the saliva of patients who developed pneumonia compared to those without pneumonia. In addition, the presence of vascular brain diseases and the dose of meperidine were also significantly associated with the occurrence of pneumonia. These results suggest that the number of oral bacteria as well as pre-existing vascular brain diseases and high-dose narcotics can affect the incidence of post-ESD pneumonia