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排序方式: 共有812条查询结果,搜索用时 15 毫秒
71.
72.
Kazuhiro Hasegewa Ko Kitahara Toshiaki Hara Ko Takano Haruka Shimoda 《European spine journal》2009,18(4):465-470
Here we investigated the biomechanical properties of spinal segments in patients with degenerative lumbar spondylolisthesis
(DLS) using a novel intraoperative measurement system. The measurement system comprised spinous process holders, a motion
generator, a load cell, an optical displacement transducer, and a computer. Cyclic displacement of the holders produced flexion-extension
of the segment with all ligamentous structures intact. Stiffness, absorption energy (AE), and neutral zone (NZ) were determined
from the load-deformation data. Forty-one patients with DLS (M/F = 15/26, mean age 68.6 years; Group D) were studied. Adjacent
segments with normal discs in six patients (M/F = 3/3, mean age 35 years) were included as a control group (Group N). Flexion
stiffness was significantly lower in Group D than in Group N. The NZ, however, was significantly greater in Group D than in
Group N. Thus, compared to normal segments, spinal segments with DLS had a lower flexion stiffness and a higher NZ. NZs in
Group D were, however, widely distributed compared to those in Group N that showed NZ <2 mm/N in all cases, suggesting that
the segment with DLS is not always unstable and that the segments with NZ >2 mm/N can be considered as unstable.
A patent application for the intraoperative measurement system has been submitted. 相似文献
73.
Yuta Tanaka Kazuya Kurashima Haruka Saito Akiko Nagai Yusuke Tsutsumi Hisashi Doi Naoyuki Nomura Takao Hanawa 《Journal of artificial organs》2009,12(3):182-186
The in vitro short-term platelet adhesion on various metals, as accelerated by the addition of Ca2+, was evaluated in this study. Metals used for medical devices [an austenitic stainless steel, a cobalt (Co)-chromium (Cr)-molybdenum
(Mo) alloy, a titanium (Ti)-6 aluminum (Al)-4 vanadium (V) alloy, a Ti-6Al-7 niobium (Nb) alloy, a Tinickel (Ni) alloy, and
commercially pure Ti] were immersed into a platelet-rich plasma solution for 5 or 20 min, and platelet adhesion and aggregation
on the surfaces were observed using a scanning electron microscope. The platelet adhesion level on each metal after 5 min
of immersion in a platelet-rich plasma solution was the smallest in this order: stainless steel ≤ Co-Cr-Mo alloy < Ti-6Al-4V
alloy < Ti-6Al-7Nb alloy < Ti-Ni alloy = Ti. The levels after 5 min of immersion were almost the same as those after 20 min
of immersion. Platelet adhesion was minimal on stainless steel and Co-Cr-Mo alloy, which have a Cr2O3-containing passive surface oxide film, but was accelerated on Ti and Ti alloys having a TiO2-contanining film. A Cr2O3-containing oxide film has a lower relative permittivity than a TiO2-contanining film; it thus supports a larger electrostatic force than the latter, adsorbs more albumins, which work as inhibitory
proteins, and inhibits platelet aggregation. Therefore, platelet adhesion and aggregation are controlled by the composition
of the surface oxide film on a metal due to the relative permittivity of the metal, which influences the amount of adsorbed
proteins. 相似文献
74.
Masako Yoshimatsu Hideki Kitaura Yuji Fujimura Toshiko Eguchi Haruka Kohara Yukiko Morita Noriaki Yoshida 《BONE》2009,45(5):1010-1016
It has been reported that TNF-α plays an important role in bone resorption in pathological conditions. IL-12, which is a T cell mediator, is also an important inflammatory cytokine. We previously reported that IL-12 induces apoptosis in bone marrow cells treated with TNF-α in vitro via an interaction between TNF-α-induced Fas and IL-12-induced Fas ligand (FasL), and that, as a result, osteoclastogenesis is inhibited. The purpose of this study was to investigate the effects of IL-12 on TNF-α-mediated osteoclastogenesis in vivo. We administered TNF-α with and without IL-12 into the supracalvaria in mice. The numbers of osteoclasts in the sutures in the calvaria were higher in mice administered TNF-α than in control mice not administered TNF-α. The numbers of osteoclasts in mice administered both TNF-α and IL-12 were lower than those in mice administered only TNF-α. Next, we determined the levels of mRNAs for cathepsin K and tartrate-resistant acid phosphatase (TRAP). mRNA levels were increased in mice administered TNF-α compared with control mice, but not in mice administered both TNF-α and IL-12. We also evaluated the amounts of tartrate-resistant acid phosphatase 5b (TRACP 5b) in mouse sera. The levels of TRACP 5b in mice administered TNF-α were higher than those in control mice. On the other hand, in mice administered both TNF-α and IL-12, the levels were lower than those in mice administered TNF-α alone. Fas and FasL expression levels were analyzed by real-time RT-PCR. The levels of Fas mRNA were increased in the calvaria of mice administered TNF-α compared with control mice, while those of FasL mRNAs were increased in the calvaria of mice administered IL-12. In TdT-mediated dUTP-biotin nick end-labeling (TUNEL) assays, many apoptotic cells were found in the sutures in the calvaria of mice administered both TNF-α and IL-12. IL-12 also inhibited TNF-α-induced osteoclastogenesis in mice whose T cells were blocked by anti-CD4 and anti-CD8 antibodies. These results suggest that IL-12 inhibits TNF-α-mediated osteoclastogenesis and induces apoptotic changes through an interaction between TNF-α-induced Fas and IL-12-induced FasL, in vivo, via a T cell-independent mechanism. 相似文献
75.
Administrative issues related to operating child and adolescent psychiatry programs or child mental health centers are substantially
different than their adult counterpart programs. The increasing demands from managed care and other regulatory agencies make
these programs difficult to operate. The smaller scale of these programs and the fewer existing programs make managing access
to care more complicated. The administrators and clinicians in these programs have to be vigilant of legal responsibilities
and reporting mandates that child practitioners and agencies that treat children need to abide by. In order to continue thriving,
programs need to be efficient and fiscally viable. Issues such as building the continuum of care and finding the qualified
personnel to staff these services are discussed in this article. 相似文献
76.
Shimokata K Katayama Y Murayama H Suematsu M Tsukihara T Muramoto K Aoyama H Yoshikawa S Shimada H 《Proceedings of the National Academy of Sciences of the United States of America》2007,104(10):4200-4205
X-ray structures of bovine heart cytochrome c oxidase have suggested that the enzyme, which reduces O(2) in a process coupled with a proton pumping process, contains a proton pumping pathway (H-pathway) composed of a hydrogen bond network and a water channel located in tandem across the enzyme. The hydrogen bond network includes the peptide bond between Tyr-440 and Ser-441, which could facilitate unidirectional proton transfer. Replacement of a possible proton-ejecting aspartate (Asp-51) at one end of the H-pathway with asparagine, using a stable bovine gene expression system, abolishes the proton pumping activity without influencing the O(2) reduction function. Blockage of either the water channel by a double mutation (Val386Leu and Met390Trp) or proton transfer through the peptide by a Ser441Pro mutation was found to abolish the proton pumping activity without impairment of the O(2) reduction activity. These results significantly strengthen the proposal that H-pathway is involved in proton pumping. 相似文献
77.
Tokulmine J Nitta K Higa T Gushiken K Okayama H Sugahara K 《Masui. The Japanese journal of anesthesiology》2007,56(4):453-458
BACKGROUND: We checked for the occurrence of any leakage in an anesthesia circuit to estimate the present situation of airtightness of an anesthesia circuit in 55 anesthesia machines at various medical institutions in Okinawa. METHODS: Leakage was detected and measured by a leak checker. RESULTS: A certain degree of leakage was found in 28 of the anesthesia machines (51%). The average and maximal amounts of leakage in the anesthesia machines were 0.26, and 1.29 l x min(-1), respectively. Thirty-eight of anesthesia machines met the standards of a low flow leak test (69%). The average and maximal amounts of leakage in the inside circuit were 0.02, and 0.20 l x min(-1), respectively. The leak points of the inside circuit were present in a unidirectional valve for an oxygen sensor (14%) and for unknown reason (7%). The average and maximal amounts of leakage in the outside circuit were 0.24, and 1.29 l x min(-1), respectively. Leak points in the inside circuit were found in the corrugated breathing tube (82%) and canister (32%). CONCLUSIONS: Most instances of leakage of the above described anesthesia circuits were identified in the corrugated breathing tube and canister. As a result of our findings, we strongly recommend that these parts be checked very carefully during pre-anesthetic leak tests. 相似文献
78.
Kei Oya Yuta Tanaka Haruka Saito Kazuya Kurashima Kazuya Nogi Harumi Tsutsumi Yusuke Tsutsumi Hisashi Doi Naoyuki Nomura Takao Hanawa 《Biomaterials》2009,30(7):1281-1286
The effect of a cell-adhesive peptide containing Arg-Gly-Asp (RGD) immobilized through poly(ethylene glycol) (PEG) on titanium (Ti) on calcification by MC3T3-E1 cells was investigated to develop a new surface modification technique using biofunctional molecules. RGD was immobilized on Ti through PEG, both terminals of which were terminated with –NH2 and –COOH to combine with the Ti surface and RGD. PEG was immobilized on Ti with electrodeposition, and RGD, with immersion. For comparison, glycine was employed because it is the simplest molecule containing both –NH2 and –COOH at its terminals. MC3T3-E1 cells were cultured and differentiation-induced on each specimen, and the cell calcification properties were investigated. As a result, there was no significant difference in the morphology and extension of MC3T3-E1 cells cultured on each specimen, while the number of cells cultured on RGD/PEG/Ti was the largest. After differentiation-induction, there was no significant difference in the ALP activity among all specimens. On the other hand, the level of cell calcification on RGD/PEG/Ti was the highest. Therefore, the hard tissue compatibility of Ti is improved by immobilizing RGD through functional molecules which have a long molecular chain. 相似文献
79.
Marushima H Shibata S Asakura T Matsuura T Maehashi H Ishii Y Eda H Aoki K Iida Y Morikawa T Ohkawa K 《International journal of oncology》2011,39(5):1327-1336
In vitro tumor growth in a three-dimensional (3D) architecture has been demonstrated to play an important role in biology not only for developmental organogenesis and carcinogenesis, but also for analyses on reconstitution and maintenance in a variety of biological environments surrounding the cells. In addition to providing architectural similarity to living organisms, 3D culture with a radial flow bioreactor (RFB) can also closely mimic the living hypoxic microenvironment under which specific organogenesis or carcinogenesis occurs. The findings of the present study under the RFB culture conditions show that cancer cells underwent a shift from aerobic to hypoxic energy metabolism, in addition to protein expression to maintain the 3D structure. In RFB-cultured cells, protein stability of hypoxia-inducible factor 1 (HIF1) α, a subunit of HIF1, was increased without upregulation of its mRNA. Under these conditions, PHD2, HIF-prolyl-4-hydroxy-lase 2 and a HIF1 downstream enzyme, were stabilized without affecting the mRNA levels via downregulation of FK506-binding protein 8. PHD2 accumulation, which occurred concomitant with HIF1 stabilization, may have compensated for the lack of oxygen under hypoxic conditions to regulate the HIF levels. 3D-culture-induced overexpression of carbonic anhydrase (another representative HIF downstream enzyme) was found to occur independently of cell density in RFB--cultured cells, suggesting that the RFB provided an adequately hypoxic microenvironment for the cultured cells. From these results, it was hypothesized that the key factors are regulatory molecules, which stabilize and degrade HIF molecules, thereby activating the HIF1 pathway under a hypoxic milieu. 相似文献
80.