tRNA/mRNA Mimicry by tmRNA and SmpB in Trans-Translation

Since accurate translation from mRNA to protein is critical to survival, cells have developed translational quality control systems. Bacterial ribosomes stalled on truncated mRNA are rescued by a system involving tmRNA and SmpB referred to as trans-translation. Here, we review current understanding of the mechanism of trans-translation. Based on results obtained by using directed hydroxyl radical probing, we propose a new type of molecular mimicry during trans-translation. Besides such chemical approaches, biochemical and cryo-EM studies have revealed the structural and functional aspects of multiple stages of trans-translation. These intensive works provide a basis for studying the dynamics of tmRNA/SmpB in the ribosome

含歯性嚢胞より生じた原発性骨内歯原性癌腫

Malignant tumors arising from dentigerous cysts are classified as primary squamous cell carcinoma derived from an odontogenic cyst or as odontogenic carcinoma according to the 2005 WHO classification and are extremely rare. We report a malignant tumor arising from a dentigerous cyst in the right maxillary anterior teeth , together with a literature review. The patient was a 75-year-old man who visited a hospital with complaining of discomfort in the lingual part of the right maxillary anterior teeth. On panoramic radiography and plain computed tomography (CT), dentigerous cyst, keratocystic odontogenic tumor or ameloblastoma was suspected. The extirpated material was histopathologically diagnosed as an odontogenic carcinoma (in situ) arising from the dentigerous cyst. Postoperative ultrasonography (US) and contrast enhanced CT revealed no metastasis to the cervical lymph nodes. The patient is currently being followed up without resection or anticancer drug administration. Neither local recurrence nor metastases were observed 18 month after surgery.症例は75歳男性で、右上顎前歯の舌部不快感を主訴として受診した。パノラマX線撮影とCT検査により含歯性嚢胞、角化細胞歯原性腫瘍またはエナメル上皮腫が疑われた。切除切片の病理組織学的検査の結果、含歯性嚢胞より生じた歯原性癌腫と診断した。術後超音波検査と造影増強CT画像では頸部リンパ節への転移は見られなかった。抗癌剤投与はせずに経過観察中で、術後18ヵ月時点で再発や転移は見られていない。含歯性嚢胞より生じる悪性腫瘍は2005年のWHO分類によれば歯原性嚢胞由来の原発性扁平上皮癌または歯原性癌腫に分類され、極めて稀である。本症例は右上顎前歯の含歯性嚢胞より生じた悪性腫瘍であった。他の症例についても文献レビューした

Design and Performance of Superconducting Magnets for Hybrid Magnets(Part I. Establishment and Tests of Hybrid Magnet System at HFLSM)

Design, construction and performance of three superconducting magnets for the hybrid magnets installed in the High Field Laboratory for Superconducting Materials are described in detail. The compact solenoid, SM-3, without fully cryostable design forms the outer part of the most compact hybrid magnet in the world, HM-3 (32 mm bore, 20 T). Fully cryostable superconducting magnet designed under the Steckly criterion, SM-2, is the outer part of HM-2 (52 mm bore, 23 T), which has been most attractive to many experimentalists. SM-1, the outer part of HM-1 (32/52 mm bore, 31/28 T), with the Williams cryostability criterion is the world largest one of the superconducting magnets which employ Ti-doped Nb_3Sn multifilamentary conductors and can generate more than 12 T

Repeated talaporfin sodium photodynamic therapy for esophageal cancer: safety and efficacy

[Background] Talaporfin sodium photodynamic therapy (tPDT) is an effective salvage treatment for local failure after chemoradiotherapy for esophageal cancer. Repeated tPDT could also be indicated for local recurrence or residue after the first salvage tPDT. However, the safety and efficacy of repeated tPDT have not been elucidated. [Methods] We reviewed 52 patients with esophageal cancer who were treated with the first tPDT at Kyoto University Hospital between October 2015 and April 2020. [Results] Among 52 patients, repeated tPDT after the first tPDT was indicated for 13 patients (25%), of which six had residual tumor, four had local recurrence after complete response (CR) after the first tPDT at the primary site, and six had metachronous lesion. The total session of repeated tPDT was 25; 16 were for primary sites and nine were for metachronous sites. Among them, six patients (46.2%) achieved local (L)-CR and nine lesions (56.3%) achieved lesion L-CR. By session, 10 sessions (40%) achieved L-CR. There were no severe adverse events except for one patient; this patient showed grade 3 esophageal stenosis and perforation after the third tPDT on the same lesion that was previously treated with porfimer sodium photodynamic therapy four times. [Conclusion] Repeated tPDT could be an effective and safe treatment for local failure even after salvage tPDT for esophageal cancer

Characterization of Tight Junctions and Their Disruption by UVB in Human Epidermis and Cultured Keratinocytes

It has not been confirmed whether tight junctions (TJs) function as a paracellular permeability barrier in adult human skin. To clarify this issue, we performed a TJ permeability assay using human skin obtained from abdominal plastic surgery. Occludin, a marker protein of TJs, was expressed in the granular layer, in which a subcutaneously injected paracellular tracer, Sulfo-NHS-LC-Biotin (556.59Da), was halted. Incubation with ochratoxin A decreased the expression of claudin-4, an integral membrane protein of TJs, and the diffusion of paracellular tracer was no longer prevented at the TJs. These results demonstrate that human epidermis possesses TJs that function as an intercellular permeability barrier at least against small molecules (∼550Da). UVB irradiation of human skin xenografts and human skin equivalents (HSEs) resulted in functional deterioration of TJs. Immunocytochemical staining of cultured keratinocytes showed that occludin was localized into dot-like shapes and formed a discontinuous network when exposed to UVB irradiation. Furthermore, UVB irradiation downregulated the active forms of Rac1 and atypical protein kinase C, suggesting that their inactivation caused functional deterioration of TJs. In conclusion, TJs function as a paracellular barrier against small molecules (∼550Da) in human epidermis and are functionally deteriorated by UVB irradiation

General Survey of Tohoku Hybrid Magnet System(Part I. Establishment and Tests of Hybrid Magnet System at HFLSM)

Outline of Tohoku Hybrid Magnet system is briefly described. High Field Laboratory was established in the Research Institute for Iron, Steel and Other Metals, Tohoku University, in 1981, for accelerating research and development of high field superconducting materials. Three hybrid magnets generating magnetic fields more than 20 T have been constructed as its main apparatuses. The strongest hybrid magnet, HM-1, could produce 31.1 T in November, 1986, which was the world record as this kind of hybrid magnet. Several important features of the hybrid magnet system are introduced which will be also useful to understand the following papers

The Anti-Obesity Effect of the Palatinose-Based Formula Inslow is Likely due to an Increase in the Hepatic PPAR-α and Adipocyte PPAR-γ Gene Expressions

Abdominal obesity is a principal risk factor in the development of metabolic syndrome. Previously, we showed that a palatinose-based liquid formula, Inslow/MHN-01, suppressed postprandial plasma glucose level and reduced visceral fat accumulation better than the standard formula (SF). To elucidate the mechanism of Inslow-mediated anti-obesity effect, expression levels of genes involved in the glucose and lipid metabolism were compared in Inslow- and SF-fed rats. Both fasting plasma insulin level and average islet sizes were reduced in the Inslow group. We also found less abdominal fat accumulation and reduced hepatic triacylglycerol content in the Inslow group. Expression of the β-oxidation enzymes and uncoupling potein-2 (UCP-2) mRNAs in the liver of the Inslow group were higher than the SF group, which was due to a concomitant higher expression of the peroxisome proliferator-activated receptor (PPAR)-α mRNA in the former. Furthermore, expression of the UCP-2 and adiponectin mRNAs in the epididymal fat were higher in the Inslow group than the SF group, and were stimulated by a concomitant increase of the PPAR-γ gene expression in the former. These results strongly suggested that the anti-obesity effect of Inslow was due to an increase in the hepatic PPAR-α and adipocyte PPAR-γ gene expressions