Formation of hydrides in (Ti(1-x)Zr(x))Co(2.00) (0 < x < 1) pseudobinary alloys

The exposure of (Ti(1-x)Zr(x))Co(2.00) intermetallic alloys to hydrogen at high pressure caused (Ti(1-x)Zr(x))Co(2.00) (x = 0.50-0.90) hydrides in the alloy. The crystalline structural, electronic, and magnetic properties of parent alloys and of their hydrides were determined by using XRD (X-ray powder diffraction) and XAS (X-ray absorption spectrometry) and by the use of SQUID (a superconducting quantum interference device). Hydrogenation did not alter the crystal structure of the parent alloy, but it did increase the volume of the unit cell. An in situ Co K-edge XAS study of the hydride revealed that the valence state of Co increased during discharge (which is the release of hydrogen from the hydride). Hydrogenation of the parent alloy also reduced the magnetic moment. A possible mechanism of discharge for the hydride is also proposed.

The risk of psoriatic arthritis remains constant following initial diagnosis of psoriasis among patients seen in European dermatology clinics

BACKGROUND

Estimates of psoriatic arthritis (PsA) prevalence among psoriasis patients vary widely (5-40%). The time to development of PsA in patients with plaque psoriasis also remains unclear.

OBJECTIVES

To examine whether length of time since diagnosis of psoriasis affects risk of developing PsA, and to assess differences in quality of life (QoL), work-related issues, comorbidities and healthcare resource utilization (HCRU) for patients with PsA vs. psoriasis.

METHODS

This large cross-sectional observational study was conducted in the UK, Italy, France, Spain and Germany in 2006. Dermatologists who actively treated patients with psoriasis recruited 10 consecutive patients with psoriasis. Presence of PsA, body surface area (BSA) affected with psoriasis and HCRU were recorded; patients completed EUROQoL (EQ5D) and employment disadvantages questionnaires.

RESULTS

Patients with psoriasis (n = 1560) included 126 with PsA. Ninety per cent of these patients with PsA were seen by dermatologists who involved a rheumatologist in the care of their patients with PsA. Survival analysis indicated that the incidence of PsA among psoriasis patients remained constant (74 per 1000 person-years), while the prevalence increased with time since diagnosis of psoriasis, reaching 20.5% after 30 years. In addition, those with high BSA currently affected by psoriasis were more likely to have developed PsA (P < 0.028). PsA patients reported reduced QoL compared with psoriasis patients (EQ5D score: 0.56 vs. 0.82: P < 0.0005), as well as more work problems. PsA patients were more likely to be hospitalized (0.27 +/- 0.84 vs. 0.14 +/- 0.71 per year; P < 0.0005) and have additional comorbidities than those without PsA.

CONCLUSIONS

The incidence of PsA was constant after initial diagnosis of psoriasis, leading to a higher prevalence of concomitant PsA over time. PsA is associated with decreased QoL and increased work-related problems, HCRU and comorbidities. Dermatologists should screen for PsA in their patients, especially long-standing patients who did not initially present with PsA.

Calcium pyrophosphate dehydrate crystal deposition in the ligamentum flavum of the cervical spine: histopathological and immunohistochemical findings

OBJECTIVE

To investigate the histopathological and immunohistochemical properties of degenerative changes in the ligamentum flavum of the cervical spine with calcium crystal deposition.

METHODS

Sections of the calcified ligamentum flavum harvested from 26 patients who required cervical decompression were examined by scanning electron microscopy (SEM), energy dispersive X-ray microanalysis, immunohistochemical staining [for transforming growth factor (TGF)-Beta, vascular endothelial growth factor (VEGF), Sox9, and Msx2] and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labelling (TUNEL) method (for cell apoptosis).

RESULTS

Energy dispersive x-ray microanalysis and SEM confirmed the deposited calcium to be calcium pyrophosphate dihydrate (CPPD) crystals. The calcified ligamentum flavum showed disorganisation of the elastic fibre bundles together with increased collagen fibrils in the matrix. Abundant hypertrophic chondrocytes were noted around the calcified lesions, which were strongly immunoreactive to TGF-Beta and VEGF. Staining for Sox9 was positive in metaplastic chondrocytes but negative in hypertrophic chondrocytes. Both chondrocytes and mesenchymal cells were positive for Msx2. TUNEL-positive hypertrophic chondrocytes were significantly more noticeable in nodular than diffusely scattered type of CPPD deposition.

CONCLUSIONS

Calcium crystal deposition in the cervical ligamentum flavum seems to progress with reduction in elastic fibres, increase in collagen fibrils in the matrix, and migration of metaplastic hypertrophic chondrocytes, whose differentiation is controlled by cytokines and transcriptional factors, and potentially regulate crystal formation. The presence of abundant TUNEL-positive hypertrophic chondrocytes around CPPD deposition suggests that materials from apoptotic cells play some role in crystal deposition.

Interleukin-18-deficient mice exhibit diminished chronic inflammation and airway remodelling in ovalbumin-induced asthma model

Interleukin (IL)-18, which is produced by activated monocytes/macrophages and airway epithelial cells, is suggested to contribute to the pathophysiology of asthma by modulating airway inflammation. However, the involvement of IL-18 on modulating chronic airway inflammation and airway remodelling, which are characterized in a refractory asthma model exposed to long-term antigen, has not been investigated sufficiently. We examined the role of IL-18 in chronic airway inflammation and airway remodelling by long-term antigen exposure. IL-18-deficient and C57BL/6-wild-type mice were sensitized by ovalbumin (OVA) and were then exposed to aerosolized OVA twice a week for 12 weeks. We assessed airway inflammation by assessing the infiltration of cells into the airspace and lung tissues, and airway remodelling by airway mucus expression, peribronchial fibrosis and smooth muscle thickness. In IL-18-deficient mice, when exposed to OVA, the total cells and neutrophils of the bronchoalveolar lavage fluid (BALF) were diminished, as were the number of infiltrated cells in the lung tissues. IL-18-deficient mice exposed to OVA after 12 weeks showed significantly decreased levels of interferon (IFN)-gamma, IL-13 and transforming growth factor (TGF)-beta1 in the BALF. The airway hyperresponsiveness to acetyl-beta-methacholine chloride was inhibited in IL-18-deficient mice in comparison with wild-type mice. In addition, IL-18-deficient mice exposed to OVA had fewer significant features of airway remodelling. These findings suggest that IL-18 may enhance chronic airway inflammation and airway remodelling through the production of IFN-gamma, IL-13 and TGF-beta1 in the OVA-induced asthma mouse model.

Observation of the suppression of the flux of cosmic rays above 4 x 10 (19) eV

The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.

Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.

Elevation of matrix metalloproteinases and interleukin-6 in the culprit coronary artery of myocardial infarction

BACKGROUND

Interleukin-6 (IL-6) and metalloproteinases (MMPs) are involved in the instability of vulnerable plaque associated with the induction of acute myocardial infarction (AMI). We examined the regional changes of cytokines, MMPs and adhesion molecules in patients with AMI to elucidate how these factors are involved in the onset of AMI.

MATERIALS AND METHODS

One hundred and twenty-two patients with AMI were included. Blood was aspirated from the culprit coronary artery with a thrombectomy catheter, and was also sampled from peripheral veins during the coronary intervention. Control samples were obtained from the peripheral blood of age-matched patients.

RESULTS

The serum levels of IL-6 (P < 0.05), tumour necrosis factor-alpha (P < 0.005), MMP-1 (P < 0.001), MMP-13 (P < 0.001), soluble intercellular adhesion molecule-1 (P < 0.005), and soluble vascular cellular adhesion molecule-1 (P < 0.05) in peripheral blood were significantly higher in the AMI group than in the controls. Aspirated serum contained significantly higher levels of IL-6 (P < 0.001), MMP-1 (P < 0.001), and MMP-13 (P < 0.05) compared to the peripheral blood of AMI. Serum IL-6 levels were significantly higher in the aspirated than in the peripheral blood in the patients hospitalized within 6 h and 6-12 h, but were similar in the aspirated and peripheral blood of the patients hospitalized 12-24 h after the onset of AMI. There were no differences between the aspirated serum and peripheral blood in the levels of interleukin-1beta and MMP-2.

CONCLUSIONS

The levels of MMP-1, MMP-13 and IL-6 were higher in the culprit coronary artery than in the peripheral blood. These factors appear to be involved in the early stage of AMI.

Posterior 360-degree stabilisation of the upper thoracic spine: a technical note

PURPOSE

To describe a technique involving posterior 360-degree stabilisation of the upper thoracic spine: spinal cord decompression, posterior vertebral body replacement, and then posterior instrumentation and intercostal posterolateral vertebral stabilisation.

METHODS

Three men and 4 women aged 41 to 77 (mean, 58) years underwent posterior 360-degree stabilisation of the upper thoracic spine. Their indications for surgery were bone metastasis (n=5), burst fracture (n=1), and osteoporotic collapse with cord compression (n=1). Their clinical and radiological findings and treatment outcomes were retrospectively reviewed.

RESULTS

Pain status of all patients improved after surgery: 4 had severe and 3 had mild pain preoperatively; in 3 pain became minimal and 4 had none postoperatively. All patients except one had Frankel/American Spinal Injury Association scores of E after surgery indicating complete recovery of sensory and motor function. There were no complications related to surgery or instrumentation construct. At the time of review, one patient had died of old age 8.6 years after surgery and another from local recurrence and lung metastasis 5.7 years after surgery. All other patients were living.

CONCLUSION

One-stage posterior 360-degree stabilisation and vertebral body replacement is a useful technique for upper thoracic spine surgery.

K-ras mutations and cell kinetics in Helicobacter pylori associated gastric intestinal metaplasia: a comparison before and after eradication in patients with chronic gastritis and gastric cancer

BACKGROUND

Helicobacter pylori related gastric intestinal metaplasia (IM) is considered to be a precancerous lesion.

AIMS

To identify the effects of H pylori eradication on K-ras mutations, cell kinetics in IM and histological changes in patients with and without gastric cancers in a one-year prospective study.

METHODS

Patients included group A (n = 39), chronic gastritis, and group B (n = 53), intestinal-type early gastric cancer patients who had all undergone endoscopic mucosal resection (n = 25) or surgical resection (n = 28). K-ras codon 12 mutations in IM were examined, followed by DNA sequencing analysis. Proliferating and apoptotic cells were detected with anti-Ki-67 antibody and using the TUNEL method, respectively.

RESULTS

The incidence of K-ras mutations in the cancer was only 3.8%. The mutant K-ras in IM was observed more frequently in group A (46.2%) than in group B patients (1.9%) (p<0.005). After eradication, the K-ras mutations significantly declined to 12.8% in group A (p<0.005). The mutation pattern of K-ras codon 12 before eradication was that GGT was mainly changed to AGT (50%) in group A. AGT transformation was not affected by treatment. Apoptosis in IM showed an increase after H pylori eradication in both groups (p<0.05 in group A) although no histological improvement in IM was observed. The monocyte score was significantly higher in group A than in group B (p<0.05); the score improved significantly after eradication.

CONCLUSIONS

K-ras mutations in IM do not always play a role in gastric carcinogenesis but cell kinetics, especially apoptosis, in IM may contribute to it. There are early events in K-ras mutations which are influenced by H pylori infection; some mutations may also be selected by eradication. These unstable K-ras mutations in IM may be related to lymphocyte infiltration caused by H pylori infection.

Insidious progression of paraparesis secondary to type III spinal meningeal cyst: a study of six difficult cases

STUDY DESIGN

Case report.

SETTING

Neuro-orthopaedic Unit, Fukui University Hospital, Japan.

CASE REPORT

We studied six patients with insidious progression of paraparesis caused by thoracic and thoracolumbar spine type III spinal meningeal cyst and intradural arachnoid cyst, who underwent microsurgical decompression. Histologically, some samples showed oedematous and hypertrophic changes of the arachnoidal tissue together with occasional tophaceous deposits and calcification. Surgical treatment was complete excision of the cyst, or wide fenestration of these membrane, and close a communicating fistula, if detectable. All patients improved neurologically after microscopic surgery.

CONCLUSION

We stress the significance of neuroimaging and neurological assessment in patients with gradual progression of paraparesis caused by intradural arachnoid cyst, but surgical procedure and timing of operative intervention require further considerations.

Improvement in patient-reported outcomes for patients with ankylosing spondylitis treated with etanercept 50 mg once-weekly and 25 mg twice-weekly

OBJECTIVES

The objective of this study was to assess the humanistic impact of ankylosing spondylitis (AS), and compare the effect of etanercept 50 mg once-weekly (QW), etanercept 25 mg twice-weekly (BIW) and placebo on patient-reported outcomes (PROs).

METHODS

In a 12-week, double-blind, placebo-controlled multicenter study, 356 patients with active AS received etanercept 50 mg QW, etanercept 25 mg BIW or placebo (3:3:1 randomization, respectively). PROs were assessed using Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Activity Index fatigue item, EuroQOL-5D (EQ-5D) utility, EQ-5D visual analog scale and the Medical Outcomes Short Form Questionnaire (SF-36) scores at baseline and at regular intervals. Mean changes from baseline in PROs were analysed using analysis of covariance to assess differences between etanercept and placebo, or between the two etanercept groups.

RESULTS

Consistent with earlier reports, AS was associated with quality of life (QOL) impairment and functional limitations, similar to or worse than cancer, congestive heart failure, diabetes or depression. Treatment with etanercept 50 mg QW or 25 mg BIW significantly improved QOL and functional status compared with placebo. High proportions of patients achieved clinically meaningful improvements in all PRO measures, including physical function, fatigue, pain, psychosocial domains and general health status. Improvements were similar with the two etanercept dose regimens.

CONCLUSIONS

The more convenient etanercept 50 mg QW dose regimen significantly improves function and QOL in patients with AS, similarly to the standard dosing of 25 mg BIW, supporting its use for AS therapy.

1173C>T polymorphism in VKORC1 modulates the required warfarin dose

The response to warfarin is highly variable among individuals and such variability is likely to have some genetic basis. We evaluted the effect of VKORC1 polymorphisms on warfarin response among Japanese, taking advantage of its unique population structure in which CYP2C9 *2 and *3 alleles are relatively rare. Thirty-one patients (12-34 years old; median, 22) on warfarin were recruited from a pediatric cardiology clinic. Genotyping of the C>T polymorphism at position 1173 in intron 1 of VKORC1 revealed that 26 patients (84%) were T/T homozygotes at nucleotide 1173, whereas 5 (16%) were C/T heterozygotes. Complete linkage disequilibrium was observed between the 1173C > T polymorphism and another polymorphism, the 3730G > A, in the 3' untranslated region. The C/T heterozyogtes at the 1173C > T polymorphism tended to require more warfarin than the T/T homozygotes, when adjusted for international normalized ratio (p = 0.003). Both the 1173C > T polymorphism and the 3730G > A polymorphism are likely to be inert from a functional standpoint. Rather, based on the complete linkage disequilibrium between 1173C > T and 3730G > A polymorphisms, we suspect that the actual change that defines the relative resistance to warfarin may be present in the proximity of these two polymorphisms.

An optical spectrum of the afterglow of a γ-ray burst at a redshift of z = 6.295

The prompt gamma-ray emission from gamma-ray bursts (GRBs) should be detectable out to distances of z > 10 (ref. 1), and should therefore provide an excellent probe of the evolution of cosmic star formation, reionization of the intergalactic medium, and the metal enrichment history of the Universe. Hitherto, the highest measured redshift for a GRB has been z = 4.50 (ref. 5). Here we report the optical spectrum of the afterglow of GRB 050904 obtained 3.4 days after the burst; the spectrum shows a clear continuum at the long-wavelength end of the spectrum with a sharp cut-off at around 9,000 A due to Lyman alpha absorption at z approximately 6.3 (with a damping wing). A system of absorption lines of heavy elements at z = 6.295 +/- 0.002 was also detected, yielding the precise measurement of the redshift. The Si ii fine-structure lines suggest a dense, metal-enriched environment around the progenitor of the GRB.