IVA for RV function analysis in TOF

Assessment of right ventricular (RV) function is quite important in patients with surgically corrected tetralogy of Fallot (TOF). However, quantitative assessment of RV function remains challenging, mainly because of the complex RV geometry. This prospective study investigated isovolumic acceleration (IVA), a parameter of myocardial systolic function not influenced by either preload or afterload, using tissue Doppler imaging. We evaluated IVA measured on pulmonary annulus (PA-IVA) and tricuspid annulus (TA-IVA), because we considered that PA-IVA and TA-IVA correspond with systolic function of the RV outflow tract (RVOT) and RV basal function, respectively. Thirty-nine patients with surgically repaired TOF (TOF group) and 40 age-matched healthy children (control group) were enrolled in this study. No significant difference was seen between TA-IVA (2.5 ± 0.8 m/s2) and PA-IVA (2.4 ± 0.8 m/s2) in the control group. In the TOF group, PA-IVA (1.0 ± 0.5 m/s2) was significantly lower than TA-IVA (1.3 ± 0.6 m/s2, p < 0.05). Both TA-IVA and PA-IVA were significantly lower in the TOF group than in the control group (p < 0.05 each). We concluded that PA-IVA offers a useful index to assess RVOT function in TOF patients

Solution-processed nickel tetrabenzoporphyrin thin-film transistors

We describe nickel tetrabenzoporphyrin (NiTBP) as a solution-processible organic semiconductor. Whereas porphyrins in an unmodified state are typically planar and insoluble, a precursor synthetic route (NiCP) was used to deposit thin films via solution. Amorphous, insulating thin films of NiCP were deposited, and thermally converted to polycrystalline, semiconducting NiTBP. Films were studied using optical absorption and microscopy, atomic force microscopy, and x-ray diffraction. Highly concentrated NiCP was shown to form large, needle-shaped crystals drop-cast from solution. NiTBP thin-film field-effect transistors fabricated from spun-cast films demonstrated charge-carrier field-effect mobilities on the order of 0.1 and 0.2 cm2/V s0.2cm2∕Vs and accumulation threshold voltages of −19−19 and −13−13, in the linear and saturation regimes, respectively.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87777/2/034502_1.pd

Expanded substrate specificity supported by P1′ and P2′ residues enables bacterial dipeptidyl-peptidase 7 to degrade bioactive peptides

Dipeptide production from extracellular proteins is crucial for Porphyromonas gingivalis, a pathogen related to chronic periodontitis, because its energy production is entirely dependent on the metabolism of amino acids predominantly incorporated as dipeptides. These dipeptides are produced by periplasmic dipeptidyl-peptidase (DPP)4, DPP5, DPP7, and DPP11. Although the substrate specificities of these four DPPs cover most amino acids at the penultimate position from the N terminus (P1), no DPP is known to cleave penultimate Gly, Ser, Thr, or His. Here, we report an expanded substrate preference of bacterial DPP7 that covers those residues. MALDI-TOF mass spectrometry analysis demonstrated that DPP7 efficiently degraded incretins and other gastrointestinal peptides, which were successively cleaved at every second residue, including Ala, Gly, Ser, and Gln, as well as authentic hydrophobic residues. Intravenous injection of DPP7 into mice orally administered glucose caused declines in plasma glucagon-like peptide-1 and insulin, accompanied by increased blood glucose levels. A newly developed coupled enzyme reaction system that uses synthetic fluorogenic peptides revealed that the P1′ and P2′ residues of substrates significantly elevated kcat values, providing an expanded substrate preference. This activity enhancement was most effective toward the substrates with nonfavorable but nonrepulsive P1 residues in DPP7. Enhancement of kcat by prime-side residues was also observed in DPP11 but not DPP4 and DPP5. Based on this expanded substrate specificity, we demonstrate that a combination of DPPs enables proteolytic liberation of all types of N-terminal dipeptides and ensures P. gingivalis growth and pathogenicity

Organoids with cancer stem cell-like properties secrete exosomes and HSP90 in a 3D nanoenvironment

Ability to form cellular aggregations such as tumorspheres and spheroids have been used as a morphological marker of malignant cancer cells and in particular cancer stem cells (CSC). However, the common definition of the types of cellular aggregation formed by cancer cells has not been available. We examined morphologies of 67 cell lines cultured on three dimensional morphology enhancing NanoCulture Plates (NCP) and classified the types of cellular aggregates that form. Among the 67 cell lines, 49 cell lines formed spheres or spheroids, 8 cell lines formed grape-like aggregation (GLA), 8 cell lines formed other types of aggregation, and 3 cell lines formed monolayer sheets. Seven GLA-forming cell lines were derived from adenocarcinoma among the 8 lines. A neuroendocrine adenocarcinoma cell line PC-3 formed asymmetric GLA with ductal structures on the NCPs and rapidly growing asymmetric tumors that metastasized to lymph nodes in immunocompromised mice. In contrast, another adenocarcinoma cell line DU-145 formed spheroids in vitro and spheroid-like tumors in vivo that did not metastasize to lymph nodes until day 50 after transplantation. Culture in the 3D nanoenvironment and in a defined stem cell medium enabled the neuroendocrine adenocarcinoma cells to form slowly growing large organoids that expressed multiple stem cell markers, neuroendocrine markers, intercellular adhesion molecules, and oncogenes in vitro. In contrast, the more commonly used 2D serum-contained environment reduced intercellular adhesion and induced mesenchymal transition and promoted rapid growth of the cells. In addition, the 3D stemness nanoenvironment promoted secretion of HSP90 and EpCAM-exosomes, a marker of CSC phenotype, from the neuroendocrine organoids. These findings indicate that the NCP-based 3D environment enables cells to form stem cell tumoroids with multipotency and model more accurately the in vivo tumor status at the levels of morphology and gene expression

Robust and highly efficient hiPSC generation from patient non-mobilized peripheral blood-derived CD34+ cells using the auto-erasable Sendai virus vector

Background: Disease modeling with patient-derived induced pluripotent stem cells (iPSCs) is a powerful tool forelucidating the mechanisms underlying disease pathogenesis and developing safe and effective treatments. Patientperipheral blood (PB) cells are used for iPSC generation in many cases since they can be collected with minimuminvasiveness. To derive iPSCs that lack immunoreceptor gene rearrangements, hematopoietic stem and progenitorcells (HSPCs) are often targeted as the reprogramming source. However, the current protocols generally requireHSPC mobilization and/or ex vivo expansion owing to their sparsity at the steady state and low reprogrammingefficiencies, making the overall procedure costly, laborious, and time-consuming.Methods: We have established a highly efficient method for generating iPSCs from non-mobilized PB-derivedCD34+ HSPCs. The source PB mononuclear cells were obtained from 1 healthy donor and 15 patients and werekept frozen until the scheduled iPSC generation. CD34+ HSPC enrichment was done using immunomagnetic beads,with no ex vivo expansion culture. To reprogram the CD34+-rich cells to pluripotency, the Sendai virus vectorSeVdp-302L was used to transfer four transcription factors: KLF4, OCT4, SOX2, and c-MYC. In this iPSC generationseries, the reprogramming efficiencies, success rates of iPSC line establishment, and progression time wererecorded. After generating the iPSC frozen stocks, the cell recovery and their residual transgenes, karyotypes, T cellreceptor gene rearrangement, pluripotency markers, and differentiation capability were examined.Results：We succeeded in establishing 223 iPSC lines with high reprogramming efficiencies from 15 patients with 8 different disease types. Our method allowed the rapid appearance of primary colonies (~ 8 days), all of which were expandable under feeder-free conditions, enabling robust establishment steps with less workload. After thawing, the established iPSC lines were verified to be pluripotency marker-positive and of non-T cell origin. A majority of the iPSC lines were confirmed to be transgene-free, with normal karyotypes. Their trilineage differentiation capability was also verified in a defined in vitro assay.Conclusion：This robust and highly efficient method enables the rapid and cost-effective establishment of transgene-free iPSC lines from a small volume of PB, thus facilitating the biobanking of patient-derived iPSCs and their use for the modeling of various diseases

Combined Neuroprotective Effects of Propofol and Dexmedetomidine on Endoplasmic Reticulum Stress-mediated Apoptosis in SH-SY5Y Cells

Propofol is a short-acting intravenous anesthetic agent. Dexmedetomidine, a highly selective α2-adrenergic receptor agonist, has a well-known sedative effect. Both agents exhibit cytoprotective effects in the nervous system under ischemic conditions. Recently, the combination of propofol plus dexmedetomidine was used for the sedation of mechanically ventilated patients in an intensive care unit, but there are few experimental reports of the protective effects of the propofol plus dexmedetomidine combination in cells. Meanwhile, intraoperative brain ischemia–reperfusion induces endoplasmic reticulum (ER) stress-mediated apoptosis. The aim of the present study was to clarify molecular details underlying the neuroprotection afforded by the combination of propofol plus dexmedetomidine against thapsigargin (TG)-induced ER stress in human neuroblastoma SH-SY5Y cells, and whether the combination provided more efficient neuroprotection. TG was used to generate ER stress in SH-SY5Y cells. Cells were pretreated with propofol or dexmedetomidine, individually or in combination, for 1 h before cotreatment with TG for 20 h. There was a significant increase in [Ca2+]i, caspase activation, and the expression of ER stress biomarkers in TG-induced apoptotic cells. The increase in [Ca2+]i and the induction of ER stress by TG were suppressed by pretreatment with propofol, dexmedetomidine, and their combination. The dexmedetomidine-induced reduction in caspase activity and ER stress biomarkers was inhibited by pretreatment with an α2-adrenergic receptor antagonist, but was enhanced by pretreatment with a cAMP inhibitor. Treatment with the propofol plus dexmedetomidine combination exhibited the strongest protection against TG-induced apoptosis. These results demonstrate that the combination of propofol plus dexmedetomidine at clinically relevant concentrations suppresses ER stress-induced apoptosis in neuroblastoma SH-SY5Y cells. The findings suggest that the combination of propofol plus dexmedetomidine within a clinically relevant concentration range may be used safely in patients

Effects of Snow and Remineralization Processes on Nutrient Distributions in Multi-Year Antarctic Landfast Sea Ice

We elucidated the effects of snow and remineralization processes on nutrient distributions in multi-year landfast sea ice (fast ice) in Lutzow-Holm Bay, East Antarctica. Based on sea-ice salinity, oxygen isotopic ratios, and thin section analyses, we found that the multi-year fast ice grew upward due to the year-by-year accumulation of snow. Compared to ice of seawater origin, nutrient concentrations in shallow fast ice were low due to replacement by clean and fresh snow. In deeper ice of seawater origin (the lower half of the multi-year fast ice column), remineralization was dominated by the degradation of organic matter. By comparison between first- and muti-year ice, the biological uptake and the remineralization were dominated in relatively young ice and older ice, respectively, under the physical process of brine drainage

Neuroprotective Effects of Dexmedetomidine against Thapsigargin-induced ER-stress via Activity of α₂-adrenoceptors and Imidazoline Receptors

Dexmedetomidine is a potent and highly selective α2-adrenoceptor agonist with sedative, analgesic, and sympatholytic properties, though it also exhibits some affinity for imidazoline binding sites. In addition to its sedative effects, dexmedetomidine exerts neuroprotective effects under ischemic conditions. Invasive incidents such as ischemia or hypoxia induce dysfunctions in energy production or depletion of ATP as well as accumulation and aggregation of abnormal proteins in the endoplasmic reticulum (ER), leading to an ER-stress response. In the present study, we examined whether dexmedetomidine exerts inhibitory effects on apoptosis mediated by thapsigargin-induced ER-stress in SH-SY5Y cells, and proposed a possible underlying mechanism for its neuroprotective effects. We used thapsigargin (TG) to generate an ER-stress response in SH-SY5Y cells. SH-SY5Y cells were pretreated with Dex (1–1000 nM) or receptor antagonists (atipamezole, efaroxan, BU99006, and 2’,5’-dideoxyadenosine) for 1 hour before co-treatment with 1 mM TG for 20 hours. Co-incubation with dexmedetomidine suppressed thapsigargin-induced increases in cytosolic Ca2+, caspase-4 and -3 activity, eIF2α phosphorylation, and expression of ER-stress biomarkers. Dexmedetomidine treatment also decreased cAMP levels. In the presence of atipamezole or efaroxan, but not BU99006, inhibition of eIF2α phosphorylation and CHOP expression significantly increased following treatment with dexmedetomidine in thapsigargin-treated cells. However, pretreatment with BU99006 enhanced the increase in mitochondrial membrane potential associated with dexmedetomidine treatment. The results of the present study demonstrate that dexmedetomidine at clinically relevant concentrations suppresses ER-stress-induced apoptosis in SH-SY5Y cells. Some neuroprotective effects of dexmedetomidine may be mediated by α2-adrenoceptor and I1- and I2-receptors