A synthetic Escherichia coli predator–prey ecosystem

We have constructed a synthetic ecosystem consisting of two Escherichia coli populations, which communicate bi-directionally through quorum sensing and regulate each other's gene expression and survival via engineered gene circuits. Our synthetic ecosystem resembles canonical predator–prey systems in terms of logic and dynamics. The predator cells kill the prey by inducing expression of a killer protein in the prey, while the prey rescue the predators by eliciting expression of an antidote protein in the predator. Extinction, coexistence and oscillatory dynamics of the predator and prey populations are possible depending on the operating conditions as experimentally validated by long-term culturing of the system in microchemostats. A simple mathematical model is developed to capture these system dynamics. Coherent interplay between experiments and mathematical analysis enables exploration of the dynamics of interacting populations in a predictable manner

Safety and Efficacy of the Surgical Management of Hemodialysis Patients with Gastric Cancer

This retrospective study evaluated the short- and long-term outcomes after surgical management for gastric cancer in hemodialysis patients compared to non-dialysis patients. Twelve hemodialysis patients were compared with a propensity score-matched cohort of 39 gastric cancer patients who had not undergone hemodialysis. Short- and long-term outcomes along with scores estimating physiological ability and surgical stress were evaluated in both groups. The incidence of postoperative morbidity according to the Clavien-Dindo classification was higher in the hemodialysis gastric cancer group than in the non-dialysis gastric cancer group. The 5-year overall survival rate in the non-dialysis group was 69.2% after surgical resection for gastric cancer and 22.2% in the hemodialysis group. Patients with preoperative risk scores≥0.48 had significantly poorer survival outcomes compared to those with preoperative risk scores<0.48 (5-year survival rate, 83.3% vs. 39.4%, respectively). Our analyses suggest that hemodialysis patients undergoing surgery for gastric cancer have a significantly poorer postoperative prognosis and an elevated risk of postoperative complications

Aripiprazole augmentation to antidepressant therapy in Japanese patients with major depressive disorder: A randomized, double-blind, placebo-controlled study (ADMIRE study)

AbstractObjectiveThis randomized, placebo-controlled study evaluated the efficacy and safety of a fixed dose (3mg/day) and flexible dose (3–15mg/day) schedule of aripiprazole as augmentation therapy in Japanese patients with inadequate response to antidepressant therapy (ADT).MethodDuring an 8-week prospective treatment phase, patients experiencing a major depressive episode received clinicians' choice of ADT. Subjects with inadequate response to ADT were randomized to receive adjunctive treatment with placebo (n=195), fixed dose aripiprazole (n=197) or flexible dose aripiprazole (n=194) for 6 weeks. The primary efficacy endpoint was mean change in the Montgomery–Åsberg Depression Rating Scale (MADRS) total score from the end of prospective treatment (baseline) to the end of randomized treatment.ResultsMore than 90% of patients in all treatment groups completed the 6-week double-blind treatment phase. Mean MADRS total score was improved to a significantly greater extent with fixed dose aripiprazole and flexible dose aripiprazole (−10.5 and −9.6, respectively) than with placebo (−7.4). Aripiprazole was well tolerated. The incidence of akathisia observed in the flexible dose group may relate to a higher prevalence of the CYP2D6*10 allele in Asian populations.LimitationsSix weeks of adjunctive treatment is insufficient to draw conclusions about the long-term benefits of aripiprazole. Exclusion of patients with established medical comorbidities does not reflect real-world practice.ConclusionsAripiprazole augmentation at a fixed or flexible dose was superior to ADT alone and was reasonably well tolerated in Japanese patients with inadequate response to ADT.Clinical trials registrationClinicalTrials.gov identifier NCT00876343

Sclerite formation in the hydrothermal-vent “scaly-foot” gastropod — possible control of iron sulfide biomineralization by the animal

A gastropod from a deep-sea hydrothermal field at the Rodriguez triple junction, Indian Ocean, has scale-shaped structures, called sclerites, mineralized with iron sulfides on its foot. No other organisms are known to produce a skeleton consisting of iron sulfides. To investigate whether iron sulfide mineralization is mediated by the gastropod for the function of the sclerites, we performed a detailed physical and chemical characterization. Nanostructural characterization of the iron sulfide sclerites reveals that the iron sulfide minerals pyrite (FeS2) and greigite (Fe3S4) form with unique crystal habits inside and outside of the organic matrix, respectively. The magnetic properties of the sclerites, which are mostly consistent with those predicted from their nanostructual features, are not optimized for magnetoreception and instead support use of the magnetic minerals as structural elements. The mechanical performance of the sclerites is superior to that of other biominerals used in the vent environment for predation as well as protection from predation. These characteristics, as well as the co-occurrence of brachyuran crabs, support the inference that the mineralization of iron sulfides might be controlled by the gastropod to harden the sclerites for protection from predators. Sulfur and iron isotopic analyses indicate that sulfur and iron in the sclerites originate from hydrothermal fluids rather than from bacterial metabolites, and that iron supply is unlikely to be regulated by the gastropod for iron sulfide mineralization. We propose that the gastropod may control iron sulfide mineralization by modulating the internal concentrations of reduced sulfur compounds

Cyclophosphamide Promotes Arrested Development of the Dental Root in Mice

Cyclophosphamide (CPA) is a commonly used chemotherapeutic agent to treat cancer. Among its many side effects is the well-known consequence on tooth development when administered at early ages. This study elucidated the effects of CPA on development of the mandibular molar in mice. Mice received a single intraperitoneal injection of CPA at different doses and development times. CPA treatment led to weight loss and alopecia but had no effect on disturbances in tooth eruption or crown shape. However, at higher doses, there was arrested root development and early apical foramen closure histologically related to the formation of the cervical loop structure in the apical portion of the root. In cell culture experiments, the Hertwig\u27s epithelial root sheath cell line (HERS01a) was cultured with or without CPA. At high doses of CPA, HERS01a cells showed decreases in E-cadherin expression, while N-cadherin expression was upregulated, indicating that this cadherin switch may promote an epithelial-to-mesenchymal transition (EMT)-like phenomenon. These findings suggest that administration of high doses of CPA can lead to arrested root development of the molars and an EMT-like phenomenon.福岡歯科大学2019年

A Suzaku Observation of the Low-Ionization Fe-Line Emission from RCW 86

The newly operational X-ray satellite Suzaku observed the southwestern quadrant of the supernova remnant (SNR) RCW 86 in February 2006 to study the nature of the 6.4 keV emission line first detected with the Advanced Satellite for Cosmology and Astronomy (ASCA). The new data confirm the existence of the line, localizing it for the first time; most of the line emission is adjacent and interior to the forward shock and not at the locus of the continuum hard emission. We also report the first detection of a 7.1 keV line that we interpret as the K-beta emission from low-ionization iron. The Fe-K line features are consistent with a non-equilibrium plasma of Fe-rich ejecta with n_{e}t <~ 10^9 cm^-3 s and kT_{e} ~ 5 keV. This combination of low n_{e}t and high kT_{e} suggests collisionless electron heating in an SNR shock. The Fe K-alpha line shows evidence for intrinsic broadening, with a width of 47 (34--59) eV (99% error region). The difference of the spatial distributions of the hard continuum above 3 keV and the Fe-K line emission support a synchrotron origin for the hard continuum.Comment: 6 pages with 6 figures. Accepted for PASJ Suzaku Special Issue (vo. 58, sp.1

Favorable Outcome of Repeated Salvage Surgeries for Rare Metastasis to the Ligamentum Teres Hepatis and the Upper Abdominal Wall in a Stage IV Gastric Cancer Patient

Gastric cancer with peritoneal metastases is typically a devastating diagnosis. Ligamentum teres hepatis (LTH) metastasis is an extremely rare presentation with only four known cases. Herein, we report salvage surgery of successive metastases to the abdominal wall and LTH in a patient originally presenting with advanced gastric cancer with peritoneal metastasis, leading to long-term survival. A 72-year-old man with advanced gastric cancer underwent curative-intent distal gastrectomy with D2 lymph node dissection for gastric outlet obstruction. During this procedure, three small peritoneal metastases were detected in the lesser omentum, the small mesentery, and the mesocolon; however, intraoperative abdominal lavage cytology was negative. We added cytoreductive surgery for peritoneal metastasis. The pathological diagnosis of the gastric cancer was tubular adenocarcinoma with pT4aN1pM1(PER/P1b)CY0 stage IV (Japanese classification of gastric carcinoma/JCGC 15th), or T4N1M1b stage IV (UICC 7th). Post-operative adjuvant chemotherapy with S-1 (TS-1)+cisplatin (CDDP) was administered for 8 months followed by S-1 monotherapy for 4 months. At 28 months after the initial surgery, a follow-up computed tomography (CT) detected a small mass beneath the upper abdominal wall. The ass showed mild avidity on 18F-fluorodeoxyglucose positron-emission (FDG-PET) CT. Salvage resection was performed for diagnosis and treatment, and pathological findings were consistent with primary gastric cancer metastasis. At 49 months after the initial gastrectomy, a new lesion was detected in the LTH with a similar level of avidity on FDG-PET CT as the abdominal wall metastatic lesion. We performed a second salvage surgery for the LTH tumor, which also showed pathology of gastric cancer metastasis. There has been no recurrence up to 1 year after the LTH surgery. With multidisciplinary treatment the patient has survived almost 5 years after the initial gastrectomy. Curative-intent gastrectomy with cytoreductive surgery followed by adjuvant chemotherapy for advanced gastric cancer with localized peritoneal metastasis might have had a survival benefit in our patient. Successive salvage surgeries for oligometastatic lesions in the abdominal wall and the LTH also yielded favorable outcomes

ASCA Observation of the New Transient X-ray Pulsar XTE J0111.2-7317 in the Small Magellanic Cloud

The new transient X-ray pulsar XTE J0111.2-7317 was observed with Advanced Satellite for Cosmology and Astrophysics (ASCA) on 1998 November 18, a few days after its discovery with the Proportional Counter Array onboard the Rossi X-ray Timing Explorer. The source was detected at a flux level of 3.6x10^-10 erg cm^-2 s^-1 in the 0.7--10.0 keV band, which corresponds to the X-ray luminosity of 1.8x10^38 erg s^-1, if a distance of 65 kpc for this pulsar in the Small Magellanic Cloud is assumed. Nearly sinusoidal pulsations with a period of 30.9497 +/- 0.0004 s were unambiguously detected during the ASCA observation. The pulsed fraction is low and slightly energy dependent with average value of \~27%. The energy spectrum shows a large soft excess below ~2 keV when fitted to a simple power-law type model. The soft excess is eliminated if the spectrum is fitted to an ``inversely broken power-law'' model, in which photon indices below and above a break energy of 1.5 keV are 2.3 and 0.8, respectively. The soft excess can also be described by a blackbody or a thermal bremsstrahlung when the spectrum above ~2 keV is modeled by a power-law. In these models, however, the thermal soft component requires a very large emission zone, and hence it is difficult to explain the observed pulsations at energies below 2 keV. A bright state of the source enables us to identify a weak iron line feature at 6.4 keV with an equivalent width of 50 +/- 14 eV. Pulse phase resolved spectroscopy revealed a slight hardening of the spectrum and marginal indication of an increase in the iron line strength during the pulse maximum.Comment: 8 pages, 5 Figures, to be published in ApJ. Also available at http://www-cr.scphys.kyoto-u.ac.jp/member/jun/job

Osteogenic potential for replacing cells in rat cranial defects implanted with a DNA/protamine complex paste.

Osteoinductive scaffolds are required for bone tissue engineering. The aim of the present study was to assess the osteoinductive capacity of deoxyribonucleic acid (DNA)/protamine complexes in a rat model of critical-size calvarial defects. In addition, we investigated whether cultured mesenchymal-like cells (DP-cells) outgrown from DNA/protamine complex engrafted defects could differentiate to become osteogenic cells in vitro. DNA/protamine complexes were prepared by reactions between DNA and protamine sulfate solutions with stirring. Critical-sized (8mm) calvarial defects were created in the central parietal bones of adult rats. Defects were either left empty or treated with DNA/protamine complex scaffolds. Subsequently, micro-computed tomography (micro-CT), histological, and immunohistochemical analyses were performed. Micro-CT and histological assays showed that DNA/protamine complex engrafted defects had enhanced bone regeneration. DP-cells were expanded from explants of DNA/protamine complex engrafted defects using an explant outgrowth culture system. Osteogenesis-related factors were assessed in DP-cells after treatment with an osteoblast-inducing reagent (OIR). After 3months, nearly complete healing was observed for DNA/protamine complex engrafted calvarial defects. Increased alkaline phosphatase (ALP) activity and Alizarin red staining were found for cultured DP-cells. These cells had high expression levels of osteogenic genes, including those for RUNX-2, ALP, osteopontin, and osteocalcin. These results indicated that DNA/protamine complexes could facilitate bone regeneration in calvarial defects. Moreover, in vitro osteogenic induction experiments showed that DP-cells outgrown from DNA/protamine engrafted defects had an osteogenic potential. Based on these results, we suggest that DNA/protamine complexes may recruit osteocompetent cells in these defects, where they differentiate to osteogenic cells.福岡歯科大学2015年