Stem cell in peripheral blood: a study by parabiosis of irradiated and non-irradiated animals. I. New approach to parabiosis as a method for hematologic study

1. For the purpose to obtain parabiotic rats having well maintained humoral circulation, the author observed parabionts having coerio-anastomosis and vascular anastomosis. 2. In the parabiotic rats having coerio-auastomosis when one of the parabionts was prevented from taking food and water by mouth sealing, the animals died within 5 to 6 days just as the control animals subjected to complete starvation, indicating that in coerio-anastomosis no appreciable humoral exchange was established between the two parabionts. 3. In vascular parabiosis having cross anastomosis of the aortas with polyethylene tubules, the animals died about 24 hours after the operation because of blocking thrombosis formed in the polyethylene tubules. 4. In the vascular parabiosis having cross anastomosis of the aortas by the homologous thoracic aorta animals did not survive through the operation but those having parallel anastomosis of the aortas survived after the operation for 3 weeks at largest and they seem to serve as useful tool for the parabiosis experiment.</p

Stem cell in peripheral blood: a study by parabiosis of irradiated and non-irradiated animals. II. Hematopoiesis of irradiated rat having a non-irradiated parabiont

For the purpose to confirm the existence of the stem cells of the myeloid and erythroid cells in the circulating blood and to have the information of its morphologic entity, the author conducted morphologic observations on the peripheral and bone marrow cells of the x-irradiated parabionts having non-irradiated partners joined by the vascular parabiosis devised by the author, and the following results were obtained. 1. The control rats exposed to 1000R x-ray did not show any sign of recovery of hemopoiesis in bone marrow even 8 days after irradiation. 2. In the bone marrow and spleen of the lethally irradiated animals having non-irradiated partner in parabionts, precursor cells of granulocyte and erythrocyte appeared first 4 days after conjugation irrespective of the days after irradiation, and the hemopoiesis was restored completely on the sixth to the seventh day. The results have indicated that the circulat. ing blood has the stem cells which can dedifferentiate and transform into the precursor cells of the myeloid and erythroid cells within 3 days under adequate conditions. 3. On the basis of the morphologic observations on the peripheral blood of the parabiosis and non-irradiated rats revealded non-specific cells, a discussion was made on the possibility that some atypical lymphoid cells can serve as the stem cells of the myeloid and erythroid cells.</p

Long-term maintenance of hemoglobin levels in hemodialysis patients treated with bi-weekly epoetin beta pegol switched from darbepoetin alfa: a single-center, 12-month observational study in Japan

Recent evidence on maintenance administration of epoetin beta pegol, a continuous erythropoiesis receptor activator (CERA), in dialysis patients shows the clinical benefit of bi-weekly administration (Q2W) in improving hematopoiesis and iron use efficiency. We undertook a single-center observational study of 33 Japanese maintenance dialysis patients, whose anemia had been kept stable through weekly administration (Q1W) of darbepoetin (DA), to evaluate the effectiveness of CERA Q2W switched from DA in maintaining hemoglobin (Hb) levels over a 12-month period. The target Hb level was 10.0–12.0 g/dL. Throughout the 12-month period, the mean Hb was stably maintained at 10.5–10.8 g/dL, 69.7–87.9% of the patients achieving the target Hb level. The mean CERA dose was within the range of 62.9–78.8 µg/2 weeks. The average CERA dose adjustment frequency after switching was low at 0.42–0.67 times/3 months. In both subgroups stratified by the DA dose prior to the switch, Hb levels were kept stable during CERA administration; however, in the low-dose group (10–20 µg/week of DA), the CERA and iron doses decreased over time, whereas in the high-dose group (30–60 µg/week of DA) they remained unchanged. CERA Q2W achieved long-term successful anemia management in Japanese maintenance dialysis patients after switching from DA Q1W. CERA dose was adjusted based on an overall consideration of past changes in Hb levels, erythropoiesis-stimulating agent and iron doses. Subgroup analysis showed the CERA dose in the low-dose group decreased continuously, due possibly to a long-term improvement in iron use efficiency

Tensile-stress-induced growth of ellipsoidal ω-precipitates in a Ti–20wt%Mo alloy

The effects of applied tensile stress on the growth of ellipsoidal ω phase precipitates have been investigated for a Ti–20wt%Mo alloy aged at 300 °C. The application of tensile stress accelerates the growth of ω-precipitates when the misfit strain εΜ of the precipitates along the loading direction is greater than 0; however, it does not significantly affect the growth of precipitates in cases where εΜ 0 under a tensile stress of 400–550 MPa. The growth velocity of precipitates in the case where εΜ > 0 is proportional to the tensile stress. This result, together with the misfit strain dependence of the growth of precipitates, is discussed on the basis of the interaction energy between the stress acting on an ω-precipitate and its misfit strain. The activation energies for the diffusion-controlled and interface-controlled growth are estimated to be approximately 190 and 130 kJ/mol, respectively. The value of 190 kJ/mol is consistent with the activation energy for volume diffusion of Mo in β-Ti. © 2015 Springer Science+Business Media New YorkEmbargo Period 12 months after publicatio

Clinical and Pathological Improvement in Stroke-Prone Spontaneous Hypertensive Rats Related to the Pleiotropic Effect of Cilostazol

Background and Purpose-Cerebral infarction is a major cause of death or decreasing activities of daily living. This study aimed to investigate the efficacy of commonly used antiplatelet drugs on stroke and motor and cognitive functions in relation to oxidative stress markers and insulin-like growth factor 1 receptor (IGF-1R). Methods-Stroke-prone spontaneously hypertensive rats were treated with vehicle, aspirin, clopidogrel, and cilostazol from 8 to 10 weeks of age. Physiological parameters, regional cerebral blood flow, and serum lipids were examined. Motor and cognitive functions were evaluated weekly by the Rotorod and water maze task. Spontaneous infarct volume, oxidative stress markers for lipid, protein, and DNA at the ischemic boundary zone of spontaneous infarction, and the IGF-1R-positive cell ratio in the hippocampus were immunohistochemically examined in brain sections. IGF-1R beta expression in the hippocampus was assessed by Western blotting. Results-The antiplatelet drugs, cilostazol and clopidogrel, reduced the spontaneous infarct volume more than aspirin. Only cilostazol improved motor and cognitive functions with a significant increase (P<0.05) in the memory-related IGF-1R-positive ratio and IGF-1R beta expression in the hippocampus. Cilostazol reduced the 4 oxidative stress markers in affected neurons in stroke-prone spontaneously hypertensive rats regardless of blood pressure, regional cerebral blood flow, or serum lipid levels. Conclusions-The present results suggest that a possible pleiotropic effect of cilostazol resulted in the reduction of spontaneous infarct volume and preservation of motor and spatial cognitive functions. The increase of IGF-1R-positive cells in the hippocampal CA1 region could partly explain the preservation of spatial cognitive function in stroke-prone spontaneously hypertensive rats

Implications for the Cosmic Reionization from the Optical Afterglow Spectrum of the Gamma-Ray Burst 050904 at z = 6.3

The gamma-ray burst (GRB) 050904 at z = 6.3 provides the first opportunity of probing the intergalactic medium (IGM) by GRBs at the epoch of the reionization. Here we present a spectral modeling analysis of the optical afterglow spectrum taken by the Subaru Telescope, aiming to constrain the reionization history. The spectrum shows a clear damping wing at wavelengths redward of the Lyman break, and the wing shape can be fit either by a damped Ly alpha system with a column density of log (N_HI/cm^{-2}) ~ 21.6 at a redshift close to the detected metal absorption lines (z_metal = 6.295), or by almost neutral IGM extending to a slightly higher redshift of z_{IGM,u} ~ 6.36. In the latter case, the difference from z_metal may be explained by acceleration of metal absorbing shells by the activities of the GRB or its progenitor. However, we exclude this possibility by using the light transmission feature around the Ly beta resonance, leading to a firm upper limit of z_{IGM,u} < 6.314. We then show an evidence that the IGM was largely ionized already at z=6.3, with the best-fit neutral fraction of IGM, x_HI = N_HI/N_H = 0.00, and upper limits of x_HI < 0.17 and 0.60 at 68 and 95% C.L., respectively. This is the first direct and quantitative upper limit on x_HI at z > 6. Various systematic uncertainties are examined, but none of them appears large enough to change this conclusion. To get further information on the reionization, it is important to increase the sample size of z >~ 6 GRBs, in order to find GRBs with low column densities (log N_HI <~ 20) within their host galaxies, and for statistical studies of Ly alpha line emission from host galaxies.Comment: Matches the published version in PASJ. The version with full resolution figures is available upon request to Totani or at http://www.kusastro.kyoto-u.ac.jp/~totani/up/grb050904-paper2-astroph-v3.pd

Enhancement/reduction of biological pump depends on ocean circulation in the sea-ice reduction regions of the Arctic Ocean

http://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr08-04/

High platelet reactivity is a predictor of left ventricular remodelling in patients with acute myocardial infarction

Aims Acute myocardial infarction (AMI) is associated with left ventricular remodelling (LVR), which leads to progressive heart failure. Platelets play a pivotal role in promoting systemic and cardiac inflammatory responses during the complex process of myocardial wound healing or repair following AMI. This study aimed to investigate the impact of platelet reactivity immediately after primary percutaneous coronary intervention (PCI) on LVR in AMI patients with ST-segment (STEMI) and nonST-segment elevation (NSTEMI). Methods and results This prospective, single-centre, observational study included 182 patients with AMI who underwent primary PCI (107 patient with STEMI and 75 patients with NSTEMI). Patients were administered a loading dose of aspirin plus prasugrel before the procedure, and platelet reactivity was assessed using the VerifyNow P2Y12 assay immediately after PCI. Echocardiography was performed before discharge and during the chronic phase (8 +/- 3 months after discharge). LVR was defined as a relative >= 20% increase in left ventricular end-diastolic volume index (LVEDVI). LVR in chronic phase was found in 34 patients (18.7%) whose platelet reactivity was significantly higher than those without LVR (259.6 +/- 61.5 and 213.1 +/- 74.8 P2Y12 reaction units [PRU]; P = 0.001). The occurrence of LVR did not differ between patients with STEMI and patients with NSTEMI (21.5% and 14.7%; P = 0.33). The optimal cut-off value of platelet reactivity for discriminating LVR was >= 245 PRU. LVEDVI significantly decreased at chronic phase in patients without high platelet reactivity (= d245 PRU) (P = 0.06). Multivariate logistic analysis showed that high platelet reactivity was an independent predictor of LVR after adjusting for LVEDVI before discharge (odds ratio, 4.13; 95% confidence interval, 1.85-9.79). Conclusions High platelet reactivity measured immediately after PCI was a predictor of LVR in patients with AMI during the chronic phase. The role of antiplatelet therapy on inflammation in the myocardium is a promising area for further research