Magnetic structure of phase II in U(Ru(0.96)Rh(0.04))2Si2 determined by neutron diffraction under pulsed high magnetic fields.

We report neutron diffraction measurements on U(Ru(0.96)Rh(0.04))(2)Si(2) single crystal under pulsed high magnetic fields up to 30 T applied along the tetragonal c axis. The high-field experiments revealed that the field-induced phase II above 26 T corresponds to a commensurate up-up-down ferrimagnetic structure characterized by the wave vector q=(2/3,0,0) with the magnetic moments parallel to the c axis, which naturally explains the one-third magnetization plateau and the substantially changed Fermi surface in phase II. This a-axis modulated magnetic structure indicates that the phase II near the hidden order phase is closely related to the characteristic incommensurate magnetic fluctuations at Q(1)=(0.6,0,0) in the pure system URu(2)Si(2), in contrast to the pressure-induced antiferromagnetic order at Q(0)=(1,0,0).

Neutron Laue diffraction study on the magnetic phase diagram of multiferroic MnWO4 under pulsed high magnetic fields.

We have combined time-of-flight neutron Laue diffraction and pulsed high magnetic fields at the Spallation Neutron Source to study the phase diagram of the multiferroic material MnWO(4). The control of the field-pulse timing enabled an exploration of magnetic Bragg scattering through the time dependence of both the neutron wavelength and the pulsed magnetic field. This allowed us to observe several magnetic Bragg peaks in different field-induced phases of MnWO(4) with a single instrument configuration. These phases were not previously amenable to neutron diffraction studies due to the large fields involved.

Universal magnetic structure of the half-magnetization phase in Cr-based spinels.

Using an elastic neutron scattering technique under a pulsed magnetic field up to 30 T, we determined the magnetic structure in the half-magnetization plateau phase in the spinel CdCr2O4. The magnetic structure has a cubic P4{3}32 symmetry, which is the same as that observed in HgCr2O4. This suggests that despite their different zero-field ground states a universal field-induced spin-lattice coupling mechanism is at work in the Cr-based spinels.

A high-field magnetization study of a Nd(2)Fe(14)Si(3) single crystal.

Magnetization study of a single crystal of Nd(2)Fe(14)Si(3) (with the rhombohedral Th(2)Zn(17)-type structure) reveals that the compound is a ferromagnet with a spontaneous magnetic moment of 32.3µ(B) per formula unit (at T = 2 K) and a Curie temperature equal to 495 K. The easy-magnetization direction lies close to the b-axis, tilting slightly towards the c-axis. (The b-axis [120] is not a high-symmetry direction in the crystallographic class D(3d).) The observed strong magnetic anisotropy is attributed almost entirely to the Nd sublattice, as concluded from comparison with a Y(2)Fe(14)Si(3) single crystal. A magnetic field applied along the c-axis induces a first-order spin reorientation transition at B(FOMP) = 20 T. In the process of magnetization the Nd and Fe sublattices behave as essentially non-collinear. This is manifest particularly in the downward curvature of the first (pre-FOMP) stage of the magnetization curve. It is proposed to regard this curvature as a validity criterion for the single-sublattice approximation.

[Assessment of proximal aortic anastomosis device in coronary artery bypass grafting].

The aim of this study was to assess the feasibility and safety of a new proximal anastomotic device (PAD) "Enclose II" in coronary artery bypass grafting (CABG). PAD enables the construction of a proximal aortic anastomosis without the use of partial clamp of the ascending aorta, thus reduces the incidence of adverse perioperative neurologic injury related to atheroembolic events. This device was used in 41 off-pump CABG and 11 on-pump beating heart CABG patients for performing 46 radial artery (RA) and 9 vein anastomoses to the aorta. The subjects were 43 males and 9 females, with a mean age of 63.6 years. Thirteen (25%) patients had severe atherosclerotic cerebrovascular lesions preoperatively. The mean flow in the RA graft was 52.4 +/- 26.9 ml/min and that of saphenous vein graft (SVG) was 61.1 +/- 31.9 ml/min. Angiography showed all grafts patent. There was no procedure-related adverse events or cerebrovascular complication. Enclose II device can be a valuable tool to perform RA and vein anastomoses in CABG.

[Delayed surgery for traumatic rupture of the aortic arch with an isolated left vertebral artery; report of a case].

Although traumatic rupture of the thoracic aorta has been considered a surgical emergency, we report here an example of successful delayed surgery for acute traumatic rupture of the aortic arch with an isolated left vertebral artery in an 18-year-old woman. The patient was.admitted to the intensive care unit with hemothorax and, rib fractures, and a decision was made to treat the aortic injury conservatively until the patient was stabilized. She underwent surgery after 3 months of observation. After the isolated left vertebral artery had been anastomosed to the left carotid artery, total arch replacement was performed. Delayed surgery for aortic rupture as a treatment choice may be of benefit in selected cases of complex trauma.

[Exposure for harvesting gastroepiploic artery graft].

We present out technique for harvesting the gastroepiploic artery (GEA). We use a Universal Stabilizer Arm and an assistant attachment to push the liver against the diaphragm, giving en enough working space to harvest the graft. Between January and December 2007, 99 isolated coronary artery bypass grafting (CABG)s were performed, and in 36 (36.4%) patients the GEA was harvested using this technique. The mean operation time was 251.1 +/- 40.5 minutes and the mean number of distal anastomosis was 3.6 +/- 0.8. The early patency rate of the GEA graft was 95%. Combined use of a Universal Stabilizer Arm and an assistant attachment provide good exposure for harvesting the GEA.

[On-pump beating coronary artery bypass grafting with axillary cannulation in the presence of atherosclerotic lesions in the ascending aorta].

A 72-year-old man was admitted to our hospital for dyspnea and chest pain. Coronary artery bypass grafting (CABG) was scheduled because of severe stenosis of the left main trunk. Computed tomography showed severe atherosclerotic lesions in the whole aorta, especially in the ascending aorta. Although off-pump CABG was thought to be the 1st choice, we determined that it would be difficult to establish a cardiac support device due to atherosclerotic lesions in case of sudden deterioration. We performed on-pump beating CABG with axillary cannulation with an 8 mm tube graft. Postoperatively, we recognized no symptoms of stroke, and the patient was discharged on the 12th postoperative day. Axillary cannulation using a side graft was useful in the presence of atherosclerotic lesions in the ascending aorta.

Involvement of alpha-PAK-interacting exchange factor in the PAK1-c-Jun NH(2)-terminal kinase 1 activation and apoptosis induced by benzo[a]pyrene.

Benzo[a]pyrene [B(a)P], a potent procarcinogen found in combustion products such as diesel exhaust and cigarette smoke, has been recently shown to activate the c-Jun NH(2)-terminal kinase 1 (JNK1) and induce caspase-3-mediated apoptosis in Hepa1c1c7 cells. However, the molecules of the signaling pathway that control the mitogen-activated protein kinase cascades induced by B(a)P and the interaction between those and apoptosis by B(a)P have not been well defined. We report here that B(a)P promoted Cdc42/Rac1, p21-activated kinase 1 (PAK1), and JNK1 activities in 293T and HeLa cells. Moreover, alpha-PAK-interacting exchange factor (alpha PIX) mRNA and its protein expression were upregulated by B(a)P. While overexpression of an active mutant of alpha PIX (DeltaCH) facilitated B(a)P-induced activation of Cdc42/Rac1, PAK1, and JNK1, overexpression of mutated alphaPIX (L383R, L384S), which lacks guanine nucleotide exchange factor activity, SH3 domain-deleted alphaPIX (Delta SH3), which lacks the ability to bind PAK, kinase-negative PAK1 (K299R), and kinase-negative SEK1 (K220A, K224L) inhibited B(a)P-triggered JNK1 activation. Interestingly, overexpression of alphaPIX (Delta CH) and a catalytically active mutant PAK1 (T423E) accelerated B(a)P-induced apoptosis in HeLa cells, whereas alphaPIX (Delta SH3), PAK1 (K299R), and SEK 1 (K220A, K224L) inhibited B(a)P-initiated apoptosis. Finally, a preferential caspase inhibitor, Z-Asp-CH2-DCB, strongly blocked the alphaPIX (Delta CH)-enhanced apoptosis in cells treated with B(a)P but did not block PAK1/JNK1 activation. Taken together, these results indicate that alphaPIX plays a crucial role in B(a)P-induced apoptosis through activation of the JNK1 pathway kinases.

[Embolism of the lower limb caused by native aortic valve thrombosis].

Native aortic valve thrombosis is an uncommon event with heart valve disease, during cardiac catheterization, bacterial endocarditis, or a hypercoagulative state as in antiphospholipid antibody syndrome. We report a case of thrombus formation on a native aortic valve, which was found by the transesophageal echocardiography during thrombectomy of the lower limb. We supposed that the atheromatous plaque of aortic valve was related to thrombus formation.

[Early results of new style aortosaphenous vein graft connector in coronary artery bypass grafting].

We retrospectively studied early clinical results of PAS-Port (PP) system. Fifty patients who underwent coronary artery bypass surgery with saphenous vein graft (SVG) from April 2004 to May 2005 were enrolled in this study. PP was tried for 36 SVGs in 32 patients. In 2 patients, SVG 4.0 mm in diameter could not be loaded into the device. In other 2 patients, anastomosis with PP was failed and followed by hand-sewing under aortic clamp or with Heartstring. Anastomosis with PP was successfully completed for 34 SVGs in 30 patients (group P) and conventional hand-sewing was performed for 23 SVGs in 20 patients (group C). The target vessels for SVG were similar between the 2 groups. No complication occurred in the use of PP. Postoperative angiography before discharge was performed for 31 SVGs in 27 patients (90.0%) in group P and 20 SVGs in 17 patients (85.0%) in group C. The patency rate of SVG was 96.8% in group P and 100% in group C. In conclusion, early results of PP were satisfactory compared with those of conventional hand-sewing. Severely sclerotic aorta and oversized SVG should be excluded because of possibility for incomplete deployment of the inner flange in PP.

[Extracardiac rupture of aneurysm of the noncoronary sinus of valsalva: report of a case].

A 78-year-old female was admitted to our hospital because of sudden onset of chest pain and general fatigue. A chest X-ray showed marked cardiomegaly and computed tomography (CT) revealed pericardial effusion with left pleural effusion. Upon admission to CCU, she suddenly lost consciousness and was intubated. Echocardiography confirmed increase in the amount of the pericardial effusion, which was drained at CCU. By an emergent operation, ruptured aneurysm of the noncoronary sinus of Valsalva to the pericardial space was confirmed upon opening the chest and patch plasty of the sinus of Valsalva was performed. The postoperative course was uneventful, and she was discharged on the 24th postoperative day. Extracardiac rupture of aneurysm of the sinus of Valsalva is extremely rare, and the emergent operation is indispensable.

alphaPIX nucleotide exchange factor is activated by interaction with phosphatidylinositol 3-kinase.

p21-activated kinase (PAK) is a common effector protein of the small GTPases Cdc42 and Rac, leading to the activation of downstream mitogen activated protein kinases. PAK also mediates polarized cytoskeletal changes induced by these GTPases. The recently identified PAK-interacting exchange factor (PIX) acts as a guanine nucleotide exchange factor on Rac, and colocalizes with PAK in a focal complex, but little is known about the associated signaling cascades, including upstream activators of PIX. In this study, we show that one of the isoforms of PIX, alphaPIX, is activated by signaling cascades from the platelet-derived growth factor (PDGF) receptor and EphB2 receptor, and from integrin-induced signaling through phosphatidylinositol 3-kinase (PI3-kinase). alphaPIX is activated by forming a complex with these receptors either via association with PAK and Nck, or direct association with the p85 regulatory subunit of PI3-kinase. Synthetic phosphoinositide and membrane targeted PI3-kinase augmented the alphaPIX activity in vivo. In Xenopus, aggregates of mesodermal cells derived from embryos microinjected with alphaPIX significantly increased the peripheral spreading on fibronectin substrate in response to PDGF through PI3-kinase. These results indicate that alphaPIX is activated by PI3-kinase, and is involved in the receptor mediated signaling leading to the activation of the kinase activity of PAK, and the migration of mesodermal cells on extracellular matrix.

Genomic structure of human alpha-pix, and variable deletions in a poly (T) tract in gastric cancer tissue.

PAK-interacting exchange factor (PIX) has been reported to mediate the recruitment of PAK into focal adhesions and activate Rac, thus creating a feedback loop that stimulate PAK and other targets. This pathway is thought to be related to cellular changes, such as transformation and migration, that are often encountered in cancer cells. Here, we report the genomic structure of alpha-PIX, one of the PAK- interacting exchange factors, including the identification of the promoter region, which consisted 772 amino acids in 22 exons, spanning about 100 kb on genome of X chromosome. All splice sites conformed to the GT-AT rule. To investigate the role of alpha-PIX in carcinogenesis, we screened 60 cases of gastric cancer for mutations and polymorphisms using an intron-primer that covered all the exons, but no mutations or polymorphisms were found in the coding region. However an 18 bp repeat of thymidine tract was present in 50 bp downstream from exon 12 and the deletion of variable numbers of mononucleotide repeats was observed in seven out of the 60 gastric cancer tissue specimens that were examined. These seven cases all exhibited a mutator phenotype, suggesting that the deletions are passenger mutations. Thus our results revealed that alpha-PIX probably does not play any primary role in human gastric carcinogenesis.

C-Cbl protein in human cancer tissues is frequently tyrosine phosphorylated in a tumor-specific manner.

To search for the signaling pathway relevant to the tumorigenesis in human, we examined the expression and tyrosine phosphorylation of c-cbl proto-oncogene product, c-Cbl, in various human cancer cell lines and surgical specimens. In cells derived from human cancer, we found constitutive tyrosine phosphorylation of c-Cbl protein, whereas its phosphorylation was undetectable in control ECV304 cells. Expression and tyrosine phosphorylation of c-Cbl was also examined in various surgical specimens. Thirty-six surgical specimens obtained from human tumor tissues were studied: 9 gastric carcinomas, 10 colon carcinomas, 6 renal carcinomas, 2 hepatomas, 2 brain tumors, 2 uterus tumors, 1 breast carcinoma, 1 thyroid tumor, 1 bladder tumor and 2 lung carcinomas. We found tyrosine phosphorylation of c-Cbl protein in 12 cases (33%) of these tumor tissues in a tumor-specific manner. These results suggest the importance of c-Cbl signaling in tumorigenesis in human.

Cimetidine reduces impairment of cellular immunity after cardiac operations with cardiopulmonary bypass.

OBJECTIVE: Depressive effects of cardiopulmonary bypass on cell-mediated immune responses may lead to postoperative infectious complications. We previously reported that cimetidine reduced postbypass depression of the cytotoxic activity of natural killer cells. This study evaluated cimetidine as an agent to preserve cellular immunity after cardiac operations. METHODS: In a prospective randomized study, 20 patients were divided into two groups of equal size. Cimetidine-group patients received 400 mg of cimetidine intravenously before bypass and a 33 mg/hr intravenous infusion of cimetidine after the operation, continuing until the fifth postoperative day. Control-group patients received conventional perioperative therapy. Lymphocyte subsets, natural killer cell activity, percentage of CD56+CD16+ (percentage of natural killer cells), and percentage of CD11b+CD8+ (percentage of suppressor T lymphocytes) were measured perioperatively. RESULTS: Although temporary postoperative reductions in percentages of CD3+, CD4+, and CD56+CD16+ cells were observed in both groups, CD8+ percentages on postoperative day 1 and CD11b+CD8+ percentages on postoperative days 1 and 3 in the cimetidine group were significantly lower compared with those in the control group (p = 0.01,p = 0.004, andp = 0.02, respectively). Temporary postoperative reduction of natural killer cell activity was also observed in both groups, but the natural killer cell activity on postoperative day 1 in the cimetidine group (17.1%) was significantly higher (p = 0.02) than that in the control group (8.20%). CONCLUSIONS: Cimetidine counteracts depressive effects of cardiopulmonary bypass on cell-mediated immunity and may possibly reduce postoperative susceptibility to infection.

Influence of substituting B2O3 for CaF2 on the bonding behaviour to bone of glass-ceramics containing apatite and wollastonite.

Glass-ceramics containing crystalline oxy-fluoroapatite (Ca10(PO4)6(O,F2)) and wollastonite (CaSiO3) (designated AWGC) are reported to have a fairly high mechanical strength as well as the capability of forming a chemical bond with bone tissue. The chemical composition is MgO 4.6, CaO 44.9, SiO2 34.2, P2O5 16.3, and CaF2 0.5 in weight ratio. In this study the influence of substituting B2O3 for CaF2 on the bonding behaviour of glass-ceramics containing apatite and wollastonite to bone tissue was investigated. Two kinds of glass-ceramics containing apatite and wollastonite were prepared. CaF2 0.5 was replaced with B2O3 at 0.5 and 2.0 in weight ratio (designated AWGC-0.5B and AWGC-2.0B). Rectangular ceramic plates (15 x 10 x 2 mm, abraded with No. 2000 alumina powder) were implanted into a rabbit tibia. The failure load, when an implant detached from the bone, or the bone itself broke, was measured. The failure load of AWGC-0.5B was 8.00 +/- 1.82 kg at 10 weeks after implantation and 8.16 +/- 1.36 kg at 25 weeks after implantation. The failure load of AWGC-2B was 8.08 +/- 1.70 kg at 10 weeks after implantation and 9.92 +/- 2.46 kg at 25 weeks after implantation. None of the loads for the two kinds of glass-ceramics decreased as time passed. Giemsa surface staining and contact microradiography revealed direct bonding between glass-ceramics and bone. SEM-EPMA showed a calcium-phosphorus rich layer (reaction zone) at the interface of ceramics and bone tissue. The thickness of the reaction zone was 10 to -15 microns and did not increase as time passed.(ABSTRACT TRUNCATED AT 250 WORDS)

Peripheral nerve regeneration along collagen filaments.

This paper describes the regeneration of severed peripheral nerve axons along collagen filaments without a tube. Two thousand collagen filaments were grafted to bridge 20 mm defects of rat sciatic nerve. The number of myelinated axons was approximately 4800 in the distal end of the nerve autograft at 8 weeks postoperatively; while in the collagen-filaments nerve guide it was 5500. The results suggested the collagen filaments guided regenerating axons effectively.

A comparative study of seminal trace elements in fertile and infertile men.

Fourteen kinds of trace elements were analyzed in the semen of 22 fertile men and 69 infertile men by means of inductively coupled plasma optical emission spectroscopy. Ca had the highest concentration, and the second and third highest concentrations were Zn and Mg, respectively. The concentrations of Ca, Cr, Mg, Pb, Sr, and Zn were almost the same between fertile and infertile men. Ni had a lower concentration in infertile than in fertile men. Many trace elements, such as Al, Cd, Cu, Mg, Mn, Mo, Sn, and Zn, had significantly higher concentrations in infertile men with normozoospermia than in fertile men. There was a significantly positive correlation between Zn and Mg levels in fertile and infertile men.