234 research outputs found
Heme-dependent autophosphorylation of a heme sensor kinase, ChrS, from Corynebacterium diphtheriae reconstituted in proteoliposomes
AbstractCorynebacterium diphteriae employs the response regulator, ChrA, and the sensor kinase, ChrS, of a two-component signal transduction system to utilize host heme iron. Although ChrS is predicted to encode a heme sensor, the sensing mechanism remains to be characterized. In this report, ChrS expressed in Eshcherichia coli membranes was solubilized and purified using decylmaltoside. ChrS protein incorporated into proteoliposomes catalyzed heme-dependent autophosphorylation by ATP. Other metalloporphyrins and iron did not stimulate kinase activity. The UV–Vis spectrum of hemin in the ChrS–proteoliposomes indicated that heme directly interacts with ChrS. This is the first functional reconstitution of a bacterial heme-sensing protein
Sirt1 expression is associated with CD31 expression in blood cells from patients with chronic obstructive pulmonary disease
Background: Cigarette smoke induced oxidative stress has been shown to reduce silent information regulator 1 (Sirt1) levels in lung tissue from smokers and patients with COPD patients. Sirt1 is known to inhibit endothelial senescence and may play a protective role in vascular cells. Endothelial progenitor cells (EPCs) are mobilized into circulation under various pathophysiological conditions, and are thought to play an important role in tissue repair in chronic obstructive lung disease (COPD). Therefore, Sirt1 and EPC-associated mRNAs were measured in blood samples from patients with COPD and from cultured CD34+ progenitor cells to examine whether these genes are associated with COPD development. Methods: This study included 358 patients with a smoking history of more than 10 pack-years. RNA was extracted from blood samples and from CD34+ progenitor cells treated with cigarette smoke extract (CSE), followed by assessment of CD31, CD34, Sirt1 mRNA, miR-34a, and miR-126-3p expression by real-time RT-PCR. Results: The expression of CD31, CD34, Sirt1 mRNAs, and miR-126-3p decreased and that of miR-34a increased in moderate COPD compared with that in control smokers. However, no significant differences in these genes were observed in blood cells from patients with severe COPD compared with those in control smokers. CSE significantly decreased Sirt1 and increased miR-34a expression in cultured progenitor cells. Conclusion: Sirt1 expression in blood cells from patients with COPD could be a biomarker for disease stability in patients with moderate COPD. MiR-34a may participate in apoptosis and/or senescence of EPCs in smokers. Decreased expression of CD31, CD34, and miR-126-3p potentially represents decreased numbers of EPCs in blood cell from patients with COPD
養殖ハマチの血液性状 : I. カタクチイワシ投餌の影響
養殖ハマチの主たる餌料であるカタクチイワシに起因する食餌性疾病の本態を究明するために,200尾のハマチにカタクチイワシを単一投与し,これを試験群とし,同時にイカナゴを単一投与した200尾のハマチを対照群として,50日間の飼育を行い,試験群に生ずる食餌性疾病の影響を血液性状,成長,肝蔵重量等について調べた.得られた結果を以下に示す.
1) 試験群では実験開始10日後には摂餌の不活発,成長の遅れ,軽度の肝萎縮等が認められ,20日後には食餌性疾病による斃死が始まり,実験終了時までに試験群の約50%が斃死した.斃死魚に見られる特徴は,体色の変化(主として黒変),肝萎縮,眼球突出などであった.
2) 試験群は血漿蛋白質量の減少及び低い血漿総コレステロール量を示したが,ヘモグロビン量及びヘマトクリット値については,斃死が盛んな時期においても,対照群に比較して有意な差を示さなかった.
3) 試験群においては,血漿蛋白質量の減少及びA/G比の変化から,グロブリン画分の減少が推測された.
4) ハマチの血漿蛋白質には電気泳動的に,6成分が認められ,両群においてIII画分の組成比の変化が認められた.
5) リポ蛋白質画分は対照群ではIV画分に相当したが,試験群では一定せず,III,IV,V,VI画分にわたり不明瞭な脂質の染色が認められた.
6) 試験群においては,セルローズアセテート膜上の,リポ蛋白質の染色が不明瞭である事,及び血漿総コレステロール量の減少から血漿脂質の減少が考えられた.
7) 試験群の脂質のTLCから,トリグリセライドの著しい減少と,それに相対的なワックスエステルの増加が認められた.Investigations have been carried out in view of verifying the effects of the disease caused by anchovy, Engraulis japonica, as a diet, on the blood properties of cultured yellow tail, Seriola quinqueradiata.
Yearling yellow tail were fed for 50 days with two different diets, i.e. one was anchovy as an experimental diet and the other was sand launce, Ammodytes personatus, as control.
The results can be summarized as follows:
i) Fish fed on anchovy showed a loss of appetite and a retarding growth after about 10 days; exhibited abnormal swimming patterns, change of body color, and atrophy of the liver after about 20 days; mortality mounted to about 50% at the end of 50 days while that of control group remained at 5% level. The dead fish showed a remarkable change of body color, severe atrophy of the liver, and protrusion of the eye-balls. The liver weight of fish fed on anchovy was smaller than that of control fish.
ii) Hemoglobin concentration and hematocrit value did not differ significantly in both groups.
iii) Total plasma cholesterol concentration of fish fed on anchovy stayed almost unchanged with their growth, while those of the controls increased.
iv) Total plasma protein and A/G ratio of fish fed on anchovy decreased with the progress of the disease. Those decreases both in total plasma protein concentration and A/G ratio indicated a decrease of globulin fraction. A/G ratio of control group, however, decreased more noticeably.
v) Cellulose acetate electrophoresis separated the plasma protein of yellow tail into six major fractions. The electrophoretic pattern varied especially on plasma fraction III.
vi) The main lipoprotein fraction agreed to the plasma fraction IV. Fish fed on anchovy freqnently lacked a lipoprotein corresponding to plasma fraction IV.
vii) The considerable decrease of plasma lipid of the fish fed on anchovy was judged to be due to a lower degree of staining intensity for lipid and to the decrement of total plasma cholesterol concentration.
viii) In the lipid classes of fish fed on anchovy, low proportions of triglycerides and phospholipids and high proportions of wax esters were noticed
Successful dual chamber ICD implantation via a persistent left superior vena cava after ratchet syndrome
The MAXI Mission on the ISS: Science and Instruments for Monitoring All Sky X-Ray Images
The MAXI (Monitor of All-sky X-ray Image) mission is the first astronomical
payload to be installed on the Japanese Experiment Module-Exposed Facility
(JEM-EF) on the ISS. It is scheduled for launch in the middle of 2009 to
monitor all-sky X-ray objects on every ISS orbit. MAXI will be more powerful
than any previous X-ray All Sky Monitor (ASM) payloads, being able to monitor
hundreds of AGN. MAXI will provide all sky images of X-ray sources of about 20
mCrab in the energy band of 2-30 keV from observation on one ISS orbit (90
min), about 4.5 mCrab for one day, and about 1 mCrab for one month. A final
detectability of MAXI could be 0.2 mCrab for 2 year observations.Comment: 12 pages, 11 figures, accepted for publication in Publications of the
Astronomical Society of Japa
MAXI GSC observations of a spectral state transition in the black hole candidate XTE J1752-223
We present the first results on the black hole candidate XTE J1752-223 from
the Gas Slit Camera (GSC) on-board the Monitor of All-sky X-ray Image (MAXI) on
the International Space Station. Including the onset of the outburst reported
by the Proportional Counter Array on-board the Rossi X-ray Timing Explorer on
2009 October 23, the MAXI/GSC has been monitoring this source approximately 10
times per day with a high sensitivity in the 2-20 keV band. XTE J1752-223 was
initially in the low/hard state during the first 3 months. An anti-correlated
behavior between the 2-4 keV and 4-20 keV bands were observed around January
20, 2010, indicating that the source exhibited the spectral transition to the
high/soft state. A transient radio jet may have been ejected when the source
was in the intermediate state where the spectrum was roughly explained by a
power-law with a photon index of 2.5-3.0. The unusually long period in the
initial low/hard state implies a slow variation in the mass accretion rate, and
the dramatic soft X-ray increase may be explained by a sudden appearance of the
accretion disk component with a relatively low innermost temperature (0.4-0.7
keV). Such a low temperature might suggest that the maximum accretion rate was
just above the critical gas evaporation rate required for the state transition.Comment: Publication of Astronomical Society of Japan Vol.62, No.5 (2010) [in
print
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