Estimation of the Postmortem Duration of Mouse Tissue by Electron Spin Resonance Spectroscopy

Electron spin resonance (ESR) method is a simple method for detecting various free radicals simultaneously and directly. However, ESR spin trap method is unsuited to analyze weak ESR signals in organs because of water-induced dielectric loss (WIDL). To minimize WIDL occurring in biotissues and to improve detection sensitivity to free radicals in tissues, ESR cuvette was modified and used with 5,5-dimethtyl-1-pyrroline N-oxide (DMPO). The tissue samples were mouse brain, hart, lung, liver, kidney, pancreas, muscle, skin, and whole blood, where various ESR spin adduct signals including DMPO-ascorbyl radical (AsA∗), DMPO-superoxide anion radical (OOH), and DMPO-hydrogen radical (H) signal were detected. Postmortem changes in DMPO-AsA∗ and DMPO-OOH were observed in various tissues of mouse. The signal peak of spin adduct was monitored until the 205th day postmortem. DMPO-AsA∗ in liver (y = 113.8–40.7 log (day), R1 = −0.779, R2 = 0.6, P < .001) was found to linearly decrease with the logarithm of postmortem duration days. Therefore, DMPO-AsA∗ signal may be suitable for detecting an oxidation stress tracer from tissue in comparison with other spin adduct signal on ESR spin trap method

Intravenous immunoglobulin for the treatment of Kawasaki disease

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To evaluate the efficacy and safety of IVIG in treating and preventing cardiac consequences of Kawasaki disease

Structure of the Bacillus subtilis 70S ribosome reveals the basis for species-specific stalling

Ribosomal stalling is used to regulate gene expression and can occur in a species-specific manner. Stalling during translation of the MifM leader peptide regulates expression of the downstream membrane protein biogenesis factor YidC2 (YqjG) in Bacillus subtilis, but not in Escherichia coli. In the absence of structures of Gram-positive bacterial ribosomes, a molecular basis for species-specific stalling has remained unclear. Here we present the structure of a Gram-positive B. subtilis MifM-stalled 70S ribosome at 3.5-3.9 angstrom, revealing a network of interactions between MifM and the ribosomal tunnel, which stabilize a non-productive conformation of the PTC that prevents aminoacyl-tRNA accommodation and thereby induces translational arrest. Complementary genetic analyses identify a single amino acid within ribosomal protein L22 that dictates the species specificity of the stalling event. Such insights expand our understanding of how the synergism between the ribosome and the nascent chain is utilized to modulate the translatome in a species-specific manner

Ultrasound Assessment of Kidney Volume in Patients with Acute Decompensated Heart Failure: A Predictor of Diuretic Resistance

［Background］Diuretics are essential for treating acute decompensated heart failure (ADHF), but the response is inconsistent. This study aimed to clarify whether kidney volume as assessed by ultrasound (US) predicts diuretic resistance in patients with ADHF. ［Methods］We enrolled 29 patients with ADHF and 32 controls. Height-adjusted kidney volume was assessed by US. We divided patients into two groups based on the median value of total daily use of furosemide (intravenous dose plus 0.5 × oral dose of furosemide equivalents) during 3 days from admission. ［Results］Patients with ADHF had a significantly smaller left kidney volume than did control subjects (27.7 ± 10.0 vs. 32.8 ± 8.8 mL/m, P < 0.05). Patients in the highdose furosemide group (? 51.7 mg/d) had a significantly lower estimated glomerular filtration rate (eGFR) and a significantly smaller kidney volume than did those in the low-dose furosemide group (eGFR: 43.9 ± 20.4 vs. 60.8± 21.6 mL/min/1.73 m2, left kidney volume: 23.2 ± 5.2vs. 32.6 ± 11.0 mL/m, right kidney volume: 26.5 ± 7.5vs. 32.6 ± 7.9 mL/m, all P < 0.05). Multivariate logistic analysis showed that left kidney volume, but not eGFR,was independently associated with the requirement of high-dose furosemide (odds ratio: 0.856, 95% confidence interval: 0.735?0.997, P < 0.05). ［Conclusion］Kidney volume as assessed by US is a useful predictor of diuretic resistance in patients with ADHF

Isoform-specific potentiation of stem and progenitor cell engraftment by AML1/RUNX1

Background: AML1/RUNX1 is the most frequently mutated gene in leukaemia and is central to the normal biology of hematopoietic stem and progenitor cells. However, the role of different AML1 isoforms within these primitive compartments is unclear. Here we investigate whether altering relative expression of AML1 isoforms impacts the balance between cell self-renewal and differentiation in vitro and in vivo. Methods and Findings: The human AML1a isoform encodes a truncated molecule with DNA-binding but no transactivation capacity. We used a retrovirus-based approach to transduce AML1a into primitive haematopoietic cells isolated from the mouse. We observed that enforced AML1a expression increased the competitive engraftment potential of murine long-term reconstituting stem cells with the proportion of AML1a-expressing cells increasing over time in both primary and secondary recipients. Furthermore, AML1a expression dramatically increased primitive and committed progenitor activity in engrafted animals as assessed by long-term culture, cobblestone formation, and colony assays. In contrast, expression of the full-length isoform AML1b abrogated engraftment potential. In vitro, AML1b promoted differentiation while AML1a promoted proliferation of progenitors capable of short-term lymphomyeloid engraftment. Consistent with these findings, the relative abundance of AML1a was highest in the primitive stem/progenitor compartment of human cord blood, and forced expression of AML1a in these cells enhanced maintenance of primitive potential both in vitro and in vivo. Conclusions: These data demonstrate that the "a" isoform of AML1 has the capacity to potentiate stem and progenitor cell engraftment, both of which are required for successful clinical transplantation. This activity is consistent with its expression pattern in both normal and leukaemic cells. Manipulating the balance of AML1 isoform expression may offer novel therapeutic strategies, exploitable in the contexts of leukaemia and also in cord blood transplantation in adults, in whom stem and progenitor cell numbers are often limiting. © 2007 Tsuzuki et al

Structural basis of Sec-independent membrane protein insertion by YidC

[プレスリリース]バイオサイエンス研究科膜分子複合機能学研究室の塚崎智也准教授らの研究グループが、タンパク質を細胞膜に組み込むメカニズムを解明しました（2014/04/17）Newly synthesized membrane proteins must be accurately inserted into the membrane, folded and assembled for proper functioning. The protein YidC inserts its substrates into the membrane, thereby facilitating membrane protein assembly in bacteria; the homologous proteins Oxa1 and Alb3 have the same function in mitochondria and chloroplasts, respectively1, 2. In the bacterial cytoplasmic membrane, YidC functions as an independent insertase and a membrane chaperone in cooperation with the translocon SecYEG3, 4, 5. Here we present the crystal structure of YidC from Bacillus halodurans, at 2.4 Å resolution. The structure reveals a novel fold, in which five conserved transmembrane helices form a positively charged hydrophilic groove that is open towards both the lipid bilayer and the cytoplasm but closed on the extracellular side. Structure-based in vivo analyses reveal that a conserved arginine residue in the groove is important for the insertion of membrane proteins by YidC. We propose an insertion mechanism for single-spanning membrane proteins, in which the hydrophilic environment generated by the groove recruits the extracellular regions of substrates into the low-dielectric environment of the membrane