Simultaneous measurement of sensor-protein dynamics and motility of a single cell by on-chip microcultivation system

Measurement of the correlation between sensor-protein expression, motility and environmental change is important for understanding the adaptation process of cells during their change of generation. We have developed a novel assay exploiting the on-chip cultivation system, which enabled us to observe the change of the localization of expressed sensor-protein and the motility for generations. Localization of the aspartate sensitive sensor protein at two poles in Escherichia coli decreased quickly after the aspartate was added into the cultivation medium. However, it took more than three generations for recovering the localization after the removal of aspartate from the medium. Moreover, the tumbling frequency was strongly related to the localization of the sensor protein in a cell. The results indicate that the change of the spatial localization of sensor protein, which was inherited for more than three generations, may contribute to cells, motility as the inheritable information

Complication of Type 1 Diabetes in Craniofacial and Dental Hard Tissue

Diabetes mellitus (DM) is a chronic systemic disease arisen under the conditions when the body cannot produce enough insulin or cannot use it effectively. Type 1 diabetes is caused by an autoimmune reaction, where the body’s defense system attacks the insulin-producing β-cells in the pancreas. Type 1 diabetes incidence has been rising all over the world, especially under the age of 15 years. There are strong premonitions of geographic difference; however, the overall annual increase in a number of affected population is estimated to be approximately 3%

The diagnostic accuracy of biomarkers for the prediction of bacteremia in patients with suspected infection: a prospective observational study

　Rapid recognition of bacteremia is important for critical care, especially in patients with suspected bloodstream infections. Procalcitonin and presepsin are widely used biomarkers in point-of care medical testing for identifying infectious diseases and sepsis; however, the diagnostic accuracy for the prediction of bacteremia is not well established. Therefore, this study aimed to evaluate the diagnostic accuracy of procalcitonin and presepsin for the prediction of bacteremia in patients with suspected bacteremia. We performed a prospective observational study at our hospital. A total of 210 patients (307 samples) who had been admitted from December 2014 through September 2016 with a suspected infection were included. Presepsin and procalcitonin were tested simultaneously with blood cultures and routine laboratory tests. One hundred and four blood samples were obtained at the emergency room (ER). Others were obtained during hospital admission. Blood cultures were positive in 34 samples; 25 samples were obtained in the ER. Presepsin and procalcitonin levels were significantly higher in patients with positive blood cultures than in those with negative blood cultures (1028.5 pg/mL vs. 485.0 pg/mL, P < 0.001 and 4.53 ng/mL vs. 0.33 ng/mL, P < 0.001, respectively). For predicting bacteremia, receiver operating characteristic curve analysis for presepsin showed an area under the curve (AUC) of 0.718 and negative predictive value (NPV) of 95%. The analysis for procalcitonin showed an AUC of 0.778 and NPV of 94.8%. C-reactive protein tests and the quick Sequential Organ Failure Assessment score in the ER failed to be useful tools for predicting bacteremia. Based on our results, procalcitonin and presepsin showed good diagnostic accuracy and NPV for predicting bacteremia among patients with suspected infection. Therefore, these biomarkers may be useful for ruling out bacteremia in patients with suspected infection

Diagnostic accuracy of 16S ribosomal RNA gene polymerase chain reaction in bacteremia: A prospective observational study

　The standard method for diagnosing bacteremia is blood culture. However, the sensitivity of blood culture is low when the number of bacteria in the blood is low or when antibiotics have already been administered. Furthermore, some bacteria are difficult to detect in blood cultures. 16S ribosomal RNA (rRNA) contains conserved sequences that are targeted for PCR amplification using universal primers. We investigated whether the threshold cycle (Ct) value of 16S rRNA real-time PCR in whole-blood samples can be used for early diagnosis of bacteremia. Ct values of the 16S rRNA real-time PCR in 307 collected specimens showed a bimodal distribution. Ct values of the blood culture-positive group were significantly lower than those of the blood culture-negative group (P < 0.001). The cutoff value of the receiver operating characteristic curve was 38.80, as determined using finite-mixture modeling and expectation-maximization algorithm. Analysis of the diagnostic accuracy at this cutoff value showed a sensitivity of 91.4%, specificity of 33.5%, positive predictive value of 15.0%, and negative predictive value of 96.8%. The Ct value of 16S rRNA real-time PCR shows high negative predictive value, it may be useful for excluding bacteremia when the cutoff value is set appropriately

Calcium sparks enhance the tissue fluidity within epithelial layers and promote apical extrusion of transformed cells

In vertebrates, newly emerging transformed cells are often apically extruded from epithelial layers through cell competition with surrounding normal epithelial cells. However, the underlying molecular mechanism remains elusive. Here, using phospho-SILAC screening, we show that phosphorylation of AHNAK2 is elevated in normal cells neighboring RasV12 cells soon after the induction of RasV12 expression, which is mediated by calcium-dependent protein kinase C. In addition, transient upsurges of intracellular calcium, which we call calcium sparks, frequently occur in normal cells neighboring RasV12 cells, which are mediated by mechanosensitive calcium channel TRPC1 upon membrane stretching. Calcium sparks then enhance cell movements of both normal and RasV12 cells through phosphorylation of AHNAK2 and promote apical extrusion. Moreover, comparable calcium sparks positively regulate apical extrusion of RasV12-transformed cells in zebrafish larvae as well. Hence, calcium sparks play a crucial role in the elimination of transformed cells at the early phase of cell competition

Investigation by Imaging Mass Spectrometry of Biomarker Candidates for Aging in the Hair Cortex

BACKGROUND: Human hair is one of the essential components that define appearance and is a useful source of samples for non-invasive biomonitoring. We describe a novel application of imaging mass spectrometry (IMS) of hair biomolecules for advanced molecular characterization and a better understanding of hair aging. As a cosmetic and biomedical application, molecules whose levels in hair altered with aging were comprehensively investigated. METHODS: Human hair was collected from 15 young (20±5 years old) and 15 older (50±5 years old) volunteers. Matrix-free laser desorption/ionization IMS was used to visualize molecular distribution in the hair sections. Hair-specific ions displaying a significant difference in the intensities between the 2 age groups were extracted as candidate markers for aging. Tissue localization of the molecules and alterations in their levels in the cortex and medulla in the young and old groups were determined. RESULTS: Among the 31 molecules detected specifically in hair sections, 2--one at m/z 153.00, tentatively assigned to be dihydrouracil, and the other at m/z 207.04, identified to be 3,4-dihydroxymandelic acid (DHMA)--exhibited a higher signal intensity in the young group than in the old, and 1 molecule at m/z 164.00, presumed to be O-phosphoethanolamine, displayed a higher intensity in the old group. Among the 3, putative O-phosphoethanolamine showed a cortex-specific distribution. The 3 molecules in cortex presented the same pattern of alteration in signal intensity with aging, whereas those in medulla did not exhibit significant alteration. CONCLUSION: Three molecules whose levels in hair altered with age were extracted. While they are all possible markers for aging, putative dihydrouracil and DHMA, are also suspected to play a role in maintaining hair properties and could be targets for cosmetic supplementation. Mapping of ion localization in hair by IMS is a powerful method to extract biomolecules in specified regions and determine their tissue distribution

Structure and properties of densified silica glass: characterizing the order within disorder

世界一構造秩序のあるガラスの合成と構造解析に成功 --ガラスの一見無秩序な構造の中に潜む秩序を抽出--. 京都大学プレスリリース. 2021-12-25.The broken symmetry in the atomic-scale ordering of glassy versus crystalline solids leads to a daunting challenge to provide suitable metrics for describing the order within disorder, especially on length scales beyond the nearest neighbor that are characterized by rich structural complexity. Here, we address this challenge for silica, a canonical network-forming glass, by using hot versus cold compression to (i) systematically increase the structural ordering after densification and (ii) prepare two glasses with the same high-density but contrasting structures. The structure was measured by high-energy X-ray and neutron diffraction, and atomistic models were generated that reproduce the experimental results. The vibrational and thermodynamic properties of the glasses were probed by using inelastic neutron scattering and calorimetry, respectively. Traditional measures of amorphous structures show relatively subtle changes upon compacting the glass. The method of persistent homology identifies, however, distinct features in the network topology that change as the initially open structure of the glass is collapsed. The results for the same high-density glasses show that the nature of structural disorder does impact the heat capacity and boson peak in the low-frequency dynamical spectra. Densification is discussed in terms of the loss of locally favored tetrahedral structures comprising oxygen-decorated SiSi4 tetrahedra

Genome-wide association study revealed novel loci which aggravate asymptomatic hyperuricaemia into gout

Objective The first ever genome-wide association study (GWAS) of clinically defined gout cases and asymptomatic hyperuricaemia (AHUA) controls was performed to identify novel gout loci that aggravate AHUA into gout. Methods We carried out a GWAS of 945 clinically defined gout cases and 1003 AHUA controls followed by 2 replication studies. In total, 2860 gout cases and 3149 AHUA controls (all Japanese men) were analysed. We also compared the ORs for each locus in the present GWAS (gout vs AHUA) with those in the previous GWAS (gout vs normouricaemia). Results This new approach enabled us to identify two novel gout loci (rs7927466 of CNTN5 and rs9952962 of MIR302F) and one suggestive locus (rs12980365 of ZNF724) at the genome-wide significance level (p<5.0×10– 8). The present study also identified the loci of ABCG2, ALDH2 and SLC2A9. One of them, rs671 of ALDH2, was identified as a gout locus by GWAS for the first time. Comparing ORs for each locus in the present versus the previous GWAS revealed three ‘gout vs AHUA GWAS’-specific loci (CNTN5, MIR302F and ZNF724) to be clearly associated with mechanisms of gout development which distinctly differ from the known gout risk loci that basically elevate serum uric acid level. Conclusions This meta-analysis is the first to reveal the loci associated with crystal-induced inflammation, the last step in gout development that aggravates AHUA into gout. Our findings should help to elucidate the molecular mechanisms of gout development and assist the prevention of gout attacks in high-risk AHUA individuals