External magnetic field effects on a distorted kagome antiferromagnet

We report bulk magnetization, and elastic and inelastic neutron scattering measurements under an external magnetic field H on the weakly coupled distorted kagome system, Cu2(OD)3Cl. Our results show that the ordered state below 6.7 K is a canted antiferromagnet and consists of large antiferromagnetic ac components and smaller ferromagnetic b components. By first-principles calculations and linear spin wave analysis, we present a simple spin Hamiltonian with nonuniform nearest neighbor exchange interactions resulting in a system of coupled spin trimers with a single-ion anisotropy that can qualitatively reproduce the spin dynamics of Cu2(OD)3Cl.

A novel HECT-type E3 ubiquitin protein ligase NEDL1 enhances the p53-mediated apoptotic cell death in its catalytic activity-independent manner

NEDL1 (NEDD4-like ubiquitin protein ligase-1) is a newly identified HECT-type E3 ubiquitin protein ligase highly expressed in favorable neuroblastomas as compared with unfavorable ones. In this study, we found that NEDL1 cooperates with p53 to induce apoptosis. During cisplatin (CDDP)-mediated apoptosis in neuroblastoma SH-SY5Y cells, p53 was induced to accumulate in association with an increase in expression levels of NEDL1. Enforced expression of NEDL1 resulted in a decrease in number of G418-resistant colonies in SH-SY5Y and U2OS cells bearing wild-type p53, whereas NEDL1 had undetectable effect on p53-deficient H1299 and SAOS-2 cells. Similarly, enforced expression of NEDL1 increased number of U2OS cells with sub-G1 DNA content. Co-immunoprecipitation and in vitro binding assays revealed that NEDL1 binds to the COOH-terminal region of p53. Luciferase reporter assay showed that NEDL1 has an ability to enhance the transcriptional activity of p53. Small interfering RNA-mediated knockdown of the endogenous NEDL1 conferred the resistance of U2OS cells to adriamycin. It is noteworthy that NEDL1 enhanced pro-apoptotic activity of p53 in its catalytic activity-independent manner. Taken together, our present findings suggest that functional interaction of NEDL1 with p53 might contribute to the induction of apoptosis in cancerous cells bearing wild-type p53.

Effects of colloidal iron overload on renal and hepatic siderosis and the femur in male rats

Genetic hemochromatosis is an iron overload disorder, and osteopenic and osteoporotic. Femoral neck bone mineral density (BMD) appears to fall with rising hepatic iron concentrations. A critical role for iron in mediating tissue injury is played via hydroxyl radical formation in nephrotoxicity. We investigated the effects of a colloidal iron overload on renal function, organ siderosis, and femoral bone in male rats. Iron overload reduced body growth, and increased the weights of the liver and spleen. Marked deposition of iron was noted in liver and kidney. Activities of lactate dehydrogenase and alkaline phosphatase were decreased, and the concentrations of blood urea nitrogen and creatinine were increased with the reduction in plasma calcium and inorganic phosphorus levels, i.e. functions of the liver and kidney might be affected by reactive oxygen species such as the superoxide radical, H2O2, and the hydroxyl radical produced by overloaded iron. Damage to the proximal tubular epithelial cells of the kidney and a loss of connectivity of cancellous bone in the epiphysis and of trabecular bone in the metaphysis of the distal femur were observed in iron-overloaded rats with a reduction of femoral bone mineral density, i.e. reabsorption of calcium from the proximal tubular epithelial cells of the kidney might be affected and urinary discharge of calcium might be elevated. It was suggested that iron overload gave rise to osteoporosis combined with renal dysfunction and liver iron overload syndrome.

Quantum-spin-liquid states in the two-dimensional kagome antiferromagnets ZnxCu4-x(OD)6Cl2

A three-dimensional system of interacting spins typically develops static long-range order when it is cooled. If the spins are quantum (S=1/2), however, novel quantum paramagnetic states may appear. The most highly sought state among them is the resonating-valence-bond state, in which every pair of neighbouring quantum spins forms an entangled spin singlet (valence bonds) and these singlets are quantum mechanically resonating among themselves. Here we provide an experimental indication for such quantum paramagnetic states existing in frustrated antiferromagnets, Zn(x)Cu(4-x)(OD)(6)Cl(2), where the S=1/2 magnetic Cu2+ moments form layers of a two-dimensional kagome lattice. We find that in Cu(4)(OD)(6)Cl(2), where distorted kagome planes are weakly coupled, a dispersionless excitation mode appears in the magnetic excitation spectrum below approximately 20 K, whose characteristics resemble those of quantum spin singlets in a solid state, known as a valence-bond solid, that breaks translational symmetry. Doping with non-magnetic Zn2+ ions reduces the distortion of the kagome lattice, and weakens the interplane coupling but also dilutes the magnetic occupancy of the kagome lattice. The valence-bond-solid state is suppressed, and for ZnCu(3)(OD)(6)Cl(2), where the kagome planes are undistorted and 90% occupied by the Cu2+ ions, the low-energy spin fluctuations become featureless.

Difference in vulnerability of cerebral arterial bifurcation and straight portion for development of endothelial damage

Cerebral atherosclerotic changes develop most commonly on the lateral side of the bifurcation, one of the sites where the wall shear stress is lowest in the cerebral arteries. Endothelial cells exposed to the lower shear stress appear to be more vulnerable to stimuli such as free radicals. We hypothesized that the difference in endothelial vulnerability on cerebral arteries may be involved in the local preference of atherogenesis. To clarify this hypothesis, the present study was carried out by using a laser-dye technique that causes cell damage by heat and free radicals. A helium-neon laser in the presence of circulating Evans blue was used to illuminate three sites of the rat middle cerebral artery; the straight portion, the apex of the bifurcation, and the lateral side of the bifurcation. The magnitude of endothelial damage was morphologically estimated with the electron microscope. After the laser irradiation, the straight portion and the lateral side of the bifurcation developed severe endothelial damage. However, the apex of the bifurcation developed no appreciable damage, showing significantly milder changes compared with other sites. The results suggest that endothelial cells are more vulnerable to stimuli by free radicals at the straight portion and the lateral side of the bifurcation than at the apex. We conclude that the imbalance between the strength of stress stimuli, such as free radicals, and the vulnerability of endothelium is likely to be one of the key requirements for the development of cerebral atherosclerotic changes.

ATM-dependent nuclear accumulation of IKK-α plays an important role in the regulation of p73-mediated apoptosis in response to cisplatin

I kappa B kinase (IKK) complex plays an important role in the regulation of signaling pathway that activates nuclear factor-kappa-B (NF-kappaB). Recently, we reported that cisplatin (CDDP) treatment causes a remarkable nuclear accumulation of IKK-alpha in association with stabilization and activation of p73. However, underlying mechanisms of CDDP-induced nuclear accumulation of IKK-alpha are elusive. Here, we found that ataxia-telangiectasia mutated (ATM) is one of upstream mediators of IKK-alpha during CDDP-induced apoptosis. In response to CDDP, ATM was phosphorylated at Ser-1981, which was accompanied with nuclear accumulation of IKK-alpha in HepG2 cells, whereas CDDP treatment had undetectable effects on IKK-alpha in ATM-deficient cells. Indirect immunofluorescence experiments demonstrated that phosphorylated form of ATM colocalizes with nuclear IKK-alpha in response to CDDP. In vitro kinase assay indicated that ATM phosphorylates IKK-alpha at Ser-473. Moreover, IKK-alpha-deficient MEFs displayed CDDP-resistant phenotype as compared with wild-type MEFs. Taken together, our present results suggest that ATM-mediated phosphorylation of nuclear IKK-alpha, which stabilizes p73, is one of the main apoptotic pathways in response to CDDP.

Stenting for chronic total occlusion of the proximal subclavian artery

SUMMARY

We report the results of 26 patients who underwent stent deployment for chronic total occlusion of proximal subclavian artery. From January 1998 to October 2005, 26 patients (18 male; mean age, 62.7 years, range 22 to 83 years), 28 lesions, underwent 29 procedures of stenting for chronic total occlusion of the proximal subclavian artery.Twenty-three patients had symptoms of claudication in their arm, no patients had subclavian steal syndrome.A brachial approach was used in 21 procedures, a femoral approach was used in five procedures, and combined femoral-brachial approach was required in three procedures. Primary stent deployment was success in 24 lesions (85.7%), and secondary procedure was success in one patient, totally 25 lesions (89.3%) were successfully treated by stenting. Procedure related complication occurred in four cases, including stent migration without symptoms in two procedures, hemianopsia on next day in a case, and TIA on unclear reason in one case. Permanent morbidity rate is 3.4% in procedure. Target lesion re-treatment required in three lesions, caused by subacute thrombosis, in-stent-restenosis, and dissection of the vessel by stent edge. The cases of subacute thrombosis and in-stent-restenosis were treated by re-PTA, and the case of dissection was treated by additional stenting. Secondary patency was 100%. We conclude that stenting for chronic total occlusion of subclavian arteries appears feasible and safe.

Evaluation of different bonded investments for dental titanium casting

The properties of several different investments were investigated including phosphate bonded, magnesia bonded, and alumina cement investments. Measurements included the setting expansion, thermal expansion, and compressive strength of investments, as well as the tensile strength, elongation, Vickers hardness (VHN) and surface roughness of titanium castings. For phosphate bonded investment, the setting expansion after being mixed with its own mixing solution was 2.10%, which was larger than the other investments; the thermal expansion was -0.25% at 200 degrees C, the compressive strength 14 and 5 MPa after heating. For titanium cast in phosphate bonded investment, the hardness on its top surface was 655 Hv, the tensile strength was 379 MPa, the elongation was 19.4%, and the surface roughness was 2.29 microm. Athough the thermal expansion of phosphate bonded investment is small, the setting expansion is large enough to compensate for the shrinkage of titanium castings. As its thermal expansion at T >/= 600 degrees C was constant and its heating-cooling cycle was almost reversible, these two properties can reduce the thermal shock and thus avoid cracking of the investment.

Revascularization procedure mainly by suction thrombectomy for acute cervical carotid occlusion

SUMMARY

In many cases, the prognosis for acute cervical carotid artery occlusion is poor. However, a standard treatment for the acute stage is not yet established. We report here the results of eight consecutive patients (mean age 71.5 years old) in which revascularization mainly by suction thrombectomy was performed under proximal protection during the acute phase. The occlusion sites were the intracranial internal carotid artery in five patients, tandem lesions of the internal carotid origin and intracranial vessel in two patients, and the common carotid artery in one patient. In addition, the subjects who received the treatment had an extent of infarction in MRI/DWI that was 1/3 or less of the internal carotid artery territory. The mean time from the onset to treatment commencement was 7.25 hours (2-28 hours). For the endovascular treatment, a guiding catheter with a balloon was used for proximal protection of the carotid artery. Revascularization was performed mainly by suction thrombectomy, and if a stenosed lesion was observed, PTA/stenting was added. Local fibrinolysis was not performed in combination with the above procedure. The treatment results were complete recanalization in three patients and partial recanalization in three patients. However, recanalization was not achieved in two patients. No hyperfusion syndrome or hemorrhagic infarction was observed postoperatively. All four patients in whom thrombi were successfully aspirated had occlusions proximal to the ophthalmic artery branch. In three of these four patients, complete recanalization was achieved. The revascularization procedure using suction thrombectomy under proximal protection was considered effective against the acute cervical carotid occlusions, in particular, those proximal to the ophthalmic artery branch.

"Mobile Nurse" platform for ubiquitous medicine

OBJECTIVES

We introduce "Mobile Nurse" (MN) - an emerging platform for the practice of ubiquitous medicine.

METHODS

By implementing in a dynamic setting of daily life the patient care traditionally provided by the clinical nurses on duty, MN aims at integral data collection and shortening the response time to the patient. MN is also capable of intelligent interaction with the patient and is able to learn from the patient's behavior and disease sign evaluation for improved personalized treatment.

RESULTS

In this paper, we outline the most essential concepts around the hardware, software and methodological designs of MN. We provide an example of the implementation, and elaborate on the possible future impact on medical practice and biomedical science research.

CONCLUSIONS

The main innovation of MN, setting it apart from current tele-medicine systems, is the ability to integrate the patient's signs and symptoms on site, providing medical professionals with powerful tools to elucidate disease mechanisms, to make proper diagnoses and to prescribe treatment.

Reliability of recalled self-report on headache intensity: investigation using ecological momentary assessment technique

Recalled evaluation of headache intensity is often affected by several factors. Recently, computerized ecological momentary assessment (EMA) has been developed to avoid such problems as recall bias. Here, we compared recalled headache intensity with momentary headache intensity using EMA in tension-type headache (TTH). Forty patients with TTH wore watch-type computers for 1 week to record momentary headache intensity and also rated their headache intensities by recall. We calculated intraclass correlation coefficients between recalled headache intensity and indices from EMA recordings in the whole study population and in two subgroups divided by variability of momentary headache intensity. The results showed that consistency and agreement of momentary and recalled headache intensity were low, and this was especially marked in the subjects whose headache varied widely. These observations suggested that variability of headache intensity may affect recall of headache intensity and this should be taken into consideration in both clinical and research settings.

The contactin 4 gene locus at 3p26 is a candidate gene of SCA16

OBJECTIVE

To identify of the gene responsible for the onset of spinocerebellar ataxia type 16 (SCA16).

METHODS

We reanalyzed the linkage of the original Japanese pedigree using updated information, including three additional subjects. We then screened all exons located in the critical region.

RESULTS

We reassigned the locus of SCA16 to 3p26.2-pter (maximum logarithm-of-odds score = 5.177) and identified only one point mutation (4,256C-->T) in the 3' untranslated region of the contactin 4 gene (CNTN4) on chromosome 3p26.2-26.3, which cosegregated with the disease. This mutation was not detected in 520 control subjects; moreover, we revised the phenotype of SCA16 from pure to complicated SCA.

CONCLUSION

The contactin 4 gene (CNTN4) is associated with cerebellar degeneration in spinocerebellar ataxia type 16. Additional studies are necessary to prove 4,256C-->T to be a causative mutation.

NF-kappaB regulates the stability and activity of p73 by inducing its proteolytic degradation through a ubiquitin-dependent proteasome pathway

Nuclear factor kappa B (NF-kappaB), which exists as heterodimeric complexes composed of p50 and p65, has been shown to play an important role in cell survival processes. In the present study, we found for the first time that NF-kappaB has an ability to induce the ubiquitin-dependent proteasomal degradation of proapoptotic p73alpha. The activation of NF-kappaB in tumor necrosis factor alpha (TNF-alpha)-stimulated H1299 cells resulted in a significant reduction in the amounts of the endogenous p73alpha. Consistent with these results, TNF-alpha-mediated downregulation of p73alpha was observed in wild-type (WT) mouse embryonic fibroblasts (MEFs) but not in p65-deficient MEFs. Ectopic expression of NF-kappaB decreased a half-life of p73alpha by increasing its ubiquitination levels, and thereby inhibiting the transcriptional activity as well as proapoptotic function of p73alpha, whereas NF-kappaB had undetectable effects on p53. Immunoprecipitation experiments demonstrated that, under our experimental conditions, NF-kappaB does not bind to p73alpha in mammalian cultured cells. In contrast to WT p65, the COOH-terminal deletion mutant of p65 (p65DeltaC) failed to reduce the expression levels of p73alpha, suggesting that NF-kappaB-mediated proteolytic degradation of p73alpha requires the transcriptional activity of NF-kappaB. Taken together, our present results imply that NF-kappaB-mediated degradation of proapoptotic p73 is a novel inhibitory mechanism of p73 that regulates cell survival and death.

Development of a novel systemic gene delivery system for cancer therapy with a tumor-specific cleavable PEG-lipid

For successful cancer gene therapy via intravenous (i.v.) administration, it is essential to optimize the stability of carriers in the systemic circulation and the cellular association after the accumulation of the carrier in tumor tissue. However, a dilemma exists regarding the use of poly(ethylene glycol) (PEG), which is useful for conferring stability in the systemic circulation, but is undesirable for the cellular uptake and the following processes. We report the development of a PEG-peptide-lipid ternary conjugate (PEG-Peptide-DOPE conjugate (PPD)). In this strategy, the PEG is removed from the carriers via cleavage by a matrix metalloproteinase (MMP), which is specifically expressed in tumor tissues. An in vitro study revealed that the PPD-modified gene carrier (Multifunctional Envelope-type Nano Device: MEND) exhibited pDNA expression activity that was dependent on the MMP expression level in the host cells. In vivo studies further revealed that the PPD was potent in stabilizing MEND in the systemic circulation and facilitating tumor accumulation. Moreover, the i.v. administration of PPD or PEG/PPD dually-modified MEND resulted in the stimulation of pDNA expression in tumor tissue, as compared with a conventional PEG-modified MEND. Thus, MEND modified with PPD is a promising device, which has the potential to make in vivo cancer gene therapy achievable.

Computed Tomography Angiography of Carotid Stent. Comparison of Various Self-expandable Stent in a Phantom Model

SUMMARY

We evaluated Computed Tomography Angiography (CTA) of four different self-expandable stents in phantom model. Three stents ware made of nitinol and one was made of cobaltbased alloy. Each stent placed in plastic injector, filled with diluted iodinated contrast material, and placed on a plastic case filled with saline. CTA was performed on a four-detector CT scanner (detector collimation, 0.5mm: helical pitch 3.5). Axial and longitudinal reconstructions of CT imaging were compared with the instent attenuation. Three nitinol stents showed few artifact, and cobalt-based alloy stent was appeared artificial narrowing. In conclusion, CTA is useful for follow-up examination after carotid artery stenting (CAS) as a less invasive evaluation method.

8-1A, a human monoclonal antibody that reacts with intact human chorionic gonadotropin

The incidence of choriocarcinoma has decreased over time and therapeutic results have improved about 90% complete remission in patients without extensive metastasis. However, some choriocarcinomas metastasize to other organs and show resistance to chemotherapy, having a poor prognosis despite multidisciplinary treatment. Better methods of early diagnosis for recurrence or micrometastasis, and treatment against cases with intractable gestational trophoblastic neoplasia (GTN) are needed to improve the prognosis. Human chorionic gonadotropin (hCG) is a glycoprotein hormone composed of two dissimilar subunits and a tumor marker to make a diagnosis and monitor therapeutic effect in GTN. Even when hCG levels in the serum become too low to measure with the hCG beta-CTP system which is the most sensitive assay, there are estimated to be approximately 10,000 trophoblastic cells in the body. Residual trophoblast cells may cause symptoms such as bleeding or undergo malignant transformation to choriocarcinoma. Since most monoclonal antibodies developed so far are murine, administration creates human anti-mouse antibodies, resulting in clinical failure. More recent mouse/human chimeric antibodies or humanized antibodies still possess substantial immunogenicity that makes repeated administration difficult. In the present study, KM mice that can produce completely human monoclonal antibodies were used to prepare hCG-specific human monoclonal antibody. This yielded 8-1A, a human monoclonal antibody capable of reacting with intact hCG. In the future, new diagnostic techniques and treatments for chorionic diseases may be developed using this kind of human monoclonal antibody.

Isolation and characterization of psychrotrophs from subterranean environments

Subterranean environments are potential sources for the isolation of novel microorganisms. Water and soil samples were collected at depths ranging from 10 to 1800 meters below the surface, and screening was carried out with aerobic rich and anaerobic minimal media. Two psychrotrophic and three chemoautotrophic strains were isolated. One of the psychrotrophic isolates, designated SN16A, grew at temperatures between -5 and 37 degrees C with optimal growth between 25 and 30 degrees C. The other psychrotroph, designated KB700A, grew between -10 and 30 degrees C. Little difference in growth rate could be observed between 20 and 30 degrees C; however, this strain did not grow at 37 degrees C. KB700A utilized CO2 chemoautotrophically at 30 degrees C, using hydrogen as an energy source. Both strains were characterized biochemically. The complete 16S rRNA sequence of KB700A was 98.7% homologous with that of Pseudomonas marginalis. However, the 16S rRNA of SN16A showed only 95.4% identity at maximum-with the corresponding gene of Arthrobacter globiformis-suggesting that this strain may belong to a novel genus. Both strains exhibited the ability to produce hydrolytic enzymes on plate assays. Our results suggest that subterranean environments are promising sources for the isolation of psychrotrophic microorganisms.

Evaluation of different bonded investments for dental titanium casting

The properties of several different investments were investigated including phosphate bonded, magnesia bonded, and alumina cement investments. Measurements included the setting expansion, thermal expansion, and compressive strength of investments, as well as the tensile strength, elongation, Vickers hardness (VHN) and surface roughness of titanium castings. For phosphate bonded investment, the setting expansion after being mixed with its own mixing solution was 2.10%, which was larger than the other investments; the thermal expansion was -0.25% at 200 degrees C, the compressive strength 14 and 5 MPa after heating. For titanium cast in phosphate bonded investment, the hardness on its top surface was 655 Hv, the tensile strength was 379 MPa, the elongation was 19.4%, and the surface roughness was 2.29 microm. Although the thermal expansion of phosphate bonded investment is small, the setting expansion is large enough to compensate for the shrinkage of titanium castings. As its thermal expansion at T > or = 600 degrees C was constant and its heating-cooling cycle was almost reversible, these two properties can reduce the thermal shock and thus avoid cracking of the investment.

Experimental observation of the 1/3 magnetization plateau in the diamond-chain compound Cu3(CO3)2(OH)2

The magnetic susceptibility, high field magnetization, and specific heat measurements of Cu3(CO3)2(OH)2, which is a model substance for the frustrating diamond spin chain model, have been performed using single crystals. Two broad peaks are observed at around 20 and 5 K in both magnetic susceptibility and specific heat results. The magnetization curve has a clear plateau at one third of the saturation magnetization. The experimental results are examined in terms of theoretical expectations based on exact diagonalization and density matrix renormalization group methods. An origin of magnetic anisotropy is also discussed.

Deoxyspergualin Prophylaxis With Tacrolimus Further Improves Long-Term Graft Survival in Living-Related Renal-Transplant Recipients Transfused With Donor-Specific Blood

BACKGROUND

We examined whether deoxyspergualin (DSG) prophylaxis in combination with cyclosporine (CsA)- or tacrolimus (Tac)-based immunosuppression augments the effect of donor-specific blood transfusions (DSTs) to improve long-term survival of living-related renal-transplants.

METHODS

From May 1985 to January 1998, 176 patients received DST from one-haplotype-identical donors prior to kidney transplantation. Group A (n = 64, 1985 to 1989) received CsA, prednisolone (PSL), antilymphocyte globulin (ALG), and azathioprine (AZA). Group B (n = 89, 1989 to 1996) received CsA, PSL, ALG, and DSG. Group C (n = 23, 1996 to 1998) received Tac, PSL, ALG, and DSG, with DSG followed by AZA. Rejection episodes were classified as acute rejection (AR, within the first 3 months) or late acute rejection (LAR, from 4 months to 1 year).

RESULTS

Five-year graft survivals were 73.4%, 88.8%, and 91.3% for groups A, B, and C, respectively. The incidence of AR was 34%, 30%, and 13%, and that of LAR was 23%, 26%, and 30% for groups A, B, and C, respectively. There was no significant difference in the incidence of AR or LAR among the three groups. However, an elevated serum creatinine (sCr) > or =1 mg/dL was observed in 73%, 15%, and 0% of patients during AR, and in 53%, 30%, and 14% during LAR for groups A, B, and C, respectively. These results suggest that the severity of AR or LAR was lowest among group C, contributing to the improved long-term graft survival in these patients.

CONCLUSIONS

DSG prophylaxis with Tac-based immunosuppression further improves long-term graft survival among living-related renal-transplant recipients treated with DST by decreasing the severity of acute rejection episodes.