Stretchable spin valves on elastomer membranes by predetermined periodic fracture and random wrinkling

The first highly stretchable and sensitive spin valve sensor on elastomeric membranes are demonstrated. The sensor elements exhibit stable GMR behavior up to tensile strains of 29% in in situ stretching experiments and show no fatigue over 500 loading cycles. This remarkable stretchability is achieved by a predetermined periodic fracture mechanism that creates a meander-like pattern upon stretching.

Crossover inhibition as an indicator of convergent evolution of enzyme mechanisms: a β-lactamase and a N-terminal nucleophile hydrolase

O-Aryloxycarbonyl hydroxamates and 1,3,4-oxathiazol-2-ones have been identified as covalent inhibitors of β-lactamases and proteasomes, respectively. The products of these inhibition reactions are remarkably similar, involving carbonyl cross-linking of the active sites. We have cross-checked these inhibitors, showing that the former inhibit proteasomes and the latter β-lactamases, to form the same inactive carbonyl adducts. These results are discussed in terms of similarities of the active site structures and catalytic mechanisms. It is likely that a mechanistic imperative has led to convergent evolution of these enzyme active sites, of a β-lactam-recognizing enzyme and a N-terminal protease belonging to different amidohydrolase superfamilies.

Tumourigenic characteristics of embryonal carcinoma cells as a model for studying tumour progression of human embryonic stem cells

OBJECTIVES

The objective of this study was to compare tumourigenic characteristics of human embryonic stem cells (HESCs) and embryonal carcinoma cells (ECCs) to identify a robust and simple model for studying certain aspects of cell transformation and tumourigenesis, in tumour progression of HESCs.

MATERIALS AND METHODS

SSEA-3 positive ECCs (NTERA-2) cells were identified and compared to HESCs (ch HES-20) in terms of pluripotency and differentiation capacity, growth characteristics, gene expression profiles and signalling pathways.

RESULTS

Our results showed that NTERA-2 cells shared similarities in expression markers of pluripotency to ch HES-20 cells. However, NTERA-2 cells also expressed some markers of differentiation and had a tendency to differentiate towards ectodermal endpoints. We identified NTERA-2 cells with higher S-phase fraction in cell cycle distribution, anti-apoptosis markers and robust self-renewal ability, compared to ch HES-20 cells. Microarray analysis and real-time PCR results showed that some oncogenes were up-regulated and tumour-suppression genes were down-regulated, whereas pluripotency-related genes were up-regulated and differentiation-related genes were down-regulated, and that Wnt and Notch signalling pathways were activated during progression from ES cells to EC cells.

CONCLUSION

Tumourigenic characteristics of ECCs may provide a valuable insight into possible tumour progression of HESCs.

Effects of Radix Astragali and Radix Rehmanniae, the components of an anti-diabetic foot ulcer herbal formula, on metabolism of model CYP1A2, CYP2C9, CYP2D6, CYP2E1 and CYP3A4 probe substrates in pooled human liver microsomes and specific CYP isoforms

The present study investigated the effects of Radix Astragali (RA) and Radix Rehmanniae (RR), the major components of an anti-diabetic foot ulcer herbal formula (NF3), on the metabolism of model probe substrates of human CYP isoforms, CYP1A2, CYP2C9, CYP2D6, CYP2E1 and CYP3A4, which are important in the metabolism of a variety of xenobiotics. The effects of RA or RR on human CYP1A2 (phenacetin O-deethylase), CYP2C9 (tolbutamide 4-hydroxylase), CYP2D6 (dextromethorphan O-demethylase), CYP2E1 (chlorzoxazone 6-hydroxylase) and CYP3A4 (testosterone 6β-hydroxylase) activities were investigated using pooled human liver microsomes. NF3 competitively inhibited activities of CYP2C9 (IC(50)=0.98mg/ml) and CYP3A4 (IC(50)=0.76mg/ml), with K(i) of 0.67 and 1.0mg/ml, respectively. With specific human CYP2C9 and CYP3A4 isoforms, NF3 competitively inhibited activities of CYP2C9 (IC(50)=0.86mg/ml) and CYP3A4 (IC(50)=0.88mg/ml), with K(i) of 0.57 and 1.6mg/ml, respectively. Studies on RA or RR individually showed that RR was more important in the metabolic interaction with the model CYP probe substrates. RR dose-dependently inhibited the testosterone 6β-hydroxylation (K(i)=0.33mg/ml) while RA showed only minimal metabolic interaction potential with the model CYP probe substrates studied. This study showed that RR and the NF3 formula are metabolized mainly by CYP2C9 and/or CYP3A4, but weakly by CYP1A2, CYP2D6 and CYP2E1. The relatively high K(i) values of NF3 (for CYP2C9 and CYP3A4 metabolism) and RR (for CYP3A4 metabolism) would suggest a low potential for NF3 to cause herb-drug interaction involving these CYP isoforms.

Diagnosis and treatment of acquired aplastic anaemia in adults: 142 cases from a multicentre, prospective cohort study in Shanghai, China

To improve diagnosis and therapy for aplastic anaemia (AA) in Shanghai, clinical and laboratory data for patients with AA (n = 142) and hypocellular myelodysplastic syndrome (MDS; n = 22) were comparatively analysed (follow-up 2 - 6 years). Red blood cell distribution width and absolute lymphocyte and reticulocyte counts were significantly different between the two groups. AA was diagnosed in 54.2% of patients using a single bone marrow aspirate smear plus peripheral haemogram results, and in 95.1% using an additional bone marrow biopsy; 4.9% required multiple-site bone marrow examination. Clonal chromosomal abnormalities occurred in 3.9% and 31.8% of patients with AA and MDS, respectively. In patients with severe AA, 12.0% received antithymocyte globulin (ATG) + cyclosporin A (CSA; effectiveness rate 77.8%; 5-year survival 74.1%), 45.3% received CSA + androgen therapy (effectiveness rate 58.8%; 5-year survival 76.5%) and 26.7% received androgen monotherapy (effectiveness rate 25.0%). Multivariate analysis of prognostic factors indicated that therapy regimen and blood platelet count affected survival. Peripheral blood smears, bone marrow spicule classification and biopsy are important diagnostic factors. Standardization of evidence-based therapy and promotion of ATG + CSA would improve general therapeutic effects in AA.

Tracking intracavernously injected adipose-derived stem cells to bone marrow

Intracavernous (IC) injection of stem cells (SCs) has been shown to improve erectile function in various erectile dysfunction (ED) animal models. However, the tissue distribution of the injected cells remains unknown. In this study we tracked IC injected adipose-derived stem cells (ADSCs) in various tissues. Rat paratesticular fat was processed for ADSC isolation and culture. The animals were then subject to cavernous nerve (CN) crush injury or sham operation, followed by IC injection of one million autologous or allogeneic ADSCs that were labeled with 5-ethynyl-2-deoxyuridine (EdU). Another group of rats received IC injection of EdU-labeled allogeneic penile smooth muscle cells (PSMCs). At 2 and 7 days post-injection, penises and femoral bone marrow were processed for histological analyses. Whole femoral bone marrows were also analyzed for EdU-positive cells by flow cytometry. The results show that ADSCs exited the penis within days of IC injection and migrated preferentially to bone marrow. Allogenicity did not affect ADSC's bone marrow appearance either at 2 or 7 days, while CN injury reduced the number of ADSCs in bone marrow significantly at 7 but not 2 days. The significance of these results in relation to SC therapy for ED is discussed.

Measurement of the bottom quark contribution to nonphotonic electron production in p + p collisions at √s=200 GeV

The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at √s=200  GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of pT≥5  GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high pT.

Higher moments of net proton multiplicity distributions at RHIC

We report the first measurements of the kurtosis (κ), skewness (S), and variance (σ2) of net-proton multiplicity (Np-Np) distributions at midrapidity for Au+Au collisions at square root of s(NN)=19.6, 62.4, and 200 GeV corresponding to baryon chemical potentials (μB) between 200 and 20 MeV. Our measurements of the products κσ2 and Sσ, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long-range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the square root of s(NN) dependence of κσ2. From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for μB below 200 MeV.

Three-particle coincidence of the long range pseudorapidity correlation in high energy nucleus-nucleus collisions

We report the first three-particle coincidence measurement in pseudorapidity (Δη) between a high transverse momentum (p⊥) trigger particle and two lower p⊥ associated particles within azimuth |Δϕ|<0.7 in square root of s(NN)=200 GeV d+Au and Au+Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Δη correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Δη. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.

Differences between karyotypically normal and abnormal human embryonic stem cells

OBJECTIVES

To compare different biological characteristics of human embryonic stem cells (HESCs) between those with normal and those with abnormal karyotype.

MATERIALS AND METHODS

Culture-adapted HESCs (chHES-3) with abnormal karyotype were compared with karyotypically normal cells, with regard to pluripotency and differentiation capacity, ultrastructure, growth characteristics, gene expression profiles and signalling pathways.

RESULTS

We found a new abnormal karyotype of HESCs. We observed that chHES-3 cells with normal and abnormal karyotypes shared similarities in expression markers of pluripotency; however, karyotypically abnormal chHES-3 cells had a tendency for differentiation towards ectoderm lineages and were easily maintained in suboptimal culturing conditions. Abnormal chHES-3 cells displayed relatively mature cell organelles compared to normal cells, and karyotypically abnormal chHES-3 cells had increased survival and population growth. Genes related to cell proliferation and apoptosis were up-regulated, but genes associated with genetic instability (p53, Rb, BRCA1) were down-regulated in the karyotypically abnormal cells.

CONCLUSION

Karyotypically abnormal chHES-3 cells had a more developed capacity for proliferation, resistance to apoptosis and less genetic stability compared to normal chHES-3 cells and may be an excellent model for studying and characterizing initial stages that determine transition of embryonic stem cells into cancer stem cells.

Hydrogel based sensor arrays (2 × 2) with perforated piezoresistive diaphragms for metabolic monitoring (in vitro)

This report details the first experimental results from novel hydrogel sensor array (2 × 2) which incorporates analyte diffusion pores into a piezoresistive diaphragm for the detection of hydrogel swelling pressures and hence chemical concentrations. The sensor assembly was comprised of three components, the active four sensors, HPMA/DMA/TEGDMA (hydroxypropyl methacrylate (HPMA), N,N-dimethylaminoethyl methacrylate (DMA) and crosslinker tetra-ethyleneglycol dimethacrylate (TEGDMA)) hydrogel, and backing plate. Each of the individual sensors of the array can be used with various hydrogels used to measure the presence of a number of stimuli including pH, ionic strength, and glucose concentrations. Ideally, in the future, these sensors will be used for continuous metabolic monitoring applications and implanted subcutaneously. In this paper and to properly characterize the sensor assembly, hydrogels sensitive to changes ionic strength were synthesized using hydroxypropyl methacrylate (HPMA), N,N-dimethylaminoethyl methacrylate (DMA) and crosslinker tetra-ethyleneglycol dimethacrylate (TEGDMA) and inserted into the sensor assembly. This hydrogel quickly and reversibly swells when placed environments of physiological buffer solutions (PBS) with ionic strengths ranging from 0.025 to 0.15 M, making it ideal for proof-of-concept testing and initial characterization. The assembly was wire bonded to a printed circuit board and coated with 3 ± 0.5 μm of Parylene-C using chemical vapor deposition (CVD) to protect the sensor and electrical connections during ionic strength wet testing. Two versions of sensors were fabricated for comparison, the first incorporated diffusion pores into the diaphragm, and the second used a solid diaphragm with perforated backing plate. This new design (perforated diaphragm) was shown to have slightly higher sensitivity than solid diaphragm sensors with separate diffuse backing plates when coupled with the hydrogel. The sensitivities for the 1 mm × 1 mm, 1.25 mm × 1.25 mm, 1.5 mm × 1.5 mm perforated diaphragm sensors were 53.3 ± 6.5, 171.7 ± 8.8, and 271.47 ± 27.53 mV/V-M, respectively. These results show that perforations in the diaphragm can be used not only to allow the diffusion of analyte into the cavity but to increase mechanical stress in the piezoresistive diaphragm, thereby increasing sensor output signal. The time constants for swelling (τ_swelling) and contracting (τ_contracting) were calculated by fitting the sensor output half cycles to an exponential growth function. We found that the sensors' response was initially retarded during the preliminary hydrogel conditioning period then improved after 3-5 cycles with values of approximately 9 and 7 min for τ_swelling and τ_contracting. For all sensors tested τ_swelling > τ_contracting. This may be due to the increased loading on the hydrogel from the diaphragm during the swelling process. During contraction the diaphragm aids the hydrogel by reversibly applying mechanical pressure and therefore reducing τ_contracting. Long term stability testing showed the sensors remained functional for upwards of 2 weeks in the test phosphate buffer solution (PBS).

Excitation mapping of whispering gallery modes in silica microcavities

We report the direct observation of the electromagnetic-field distribution of whispering gallery modes in silica microcavities (spheres and toroids). It is revealed by their excitation efficiency with a tapered fiber coupler swept along the meridian. The originality of this method lies in the use of the coupler itself for the near-field mapping, eliminating the need of additional tools used in previous work. This method is successfully applied to microspheres and microtoroids.

Osmotic Swelling Pressure Response of Smart Hydrogels Suitable for Chronically-Implantable Glucose Sensors

In the last few years, a new type of glucose-sensitive hydrogel (GSH) has been developed that shrinks with increasing glucose concentration due to the formation of reversible crosslinks The first osmotic swelling pressure results measured for any member of this new class of GSH are reported, so that their suitability for use in sensors combining pressure transducers and smart gels can be evaluated. Comparison is also made with results obtained for an older type of GSH that expands with increasing glucose concentration due to an increase in the concentration of counterions within the gel. The newer type of GSH exhibits both faster kinetics and weaker fructose interference, and therefore is more suitable for in vivo glucose sensing.

Application of an ELISA-elution assay to dissociate digoxin-antibody complexes in immunoaffinity chromatography

In this study, we used a modified enzyme-linked immunosorbent assay (ELISA)-elution technique as a screening tool to select specific elution conditions. We examined 12 different elution conditions for the removal of antibodies from a complex on an ELISA plate; 0.2 mol/l glycine-HCl (pH 2.5), 1.0 mol/l acetic acid (pH 2.5), 25% methanol (pH 2.5) and 3 mol/l NaSCN showed a higher elution efficiency. We conducted affinity chromatography with these four conditions for the purification of anti-digoxin antibodies from hyperimmune sera with a digoxin-specific column using omega-aminoalkyl derivatives of Sepharose 4B, whose elution efficiency was similar to that of ELISA. We also monitored the relative specific activities during elution from the digoxin-specific column. The optimum, general-purpose dissociation reagent for this immunoaffinity system was identified as 25% methanol (pH 2.5) with an elution efficiency and relative specific activity of 88.40% and 62.25%, respectively. The high purity of the purified antibodies was demonstrated with sodium dodecyl sulphate-polyacrylamide gel electrophoresis.

Azimuthal charged-particle correlations and possible local strong parity violation

Parity-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the system's orbital momentum axis. We investigate a three-particle azimuthal correlator which is a P even observable, but directly sensitive to the charge separation effect. We report measurements of charged hadrons near center-of-mass rapidity with this observable in Au + Au and Cu + Cu collisions at square root of s(NN) = 200 GeV using the STAR detector. A signal consistent with several expectations from the theory is detected. We discuss possible contributions from other effects that are not related to parity violation.

Growth of long range forward-backward multiplicity correlations with centrality in Au + Au collisions at square root of sNN = 200 GeV

Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at square root of s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.

A standard panel of microsatellites for Asian seabass (Lates calcarifer)

Microsatellites are the most popular markers for parentage assignment and population genetic studies. To meet the demand for international comparability for genetic studies of Asian seabass, a standard panel of 28 microsatellites has been selected and characterized using the DNA of 24 individuals from Thailand, Malaysia, Indonesia and Australia. The average allele number of these markers was 10.82 +/- 0.71 (range: 6-19), and the expected heterozygosity averaged 0.76 +/- 0.02 (range: 0.63-1.00). All microsatellites showed Mendelian inheritance. In addition, eight standard size controls have been developed by cloning a set of microsatellite alleles into a pGEM-T vector to calibrate allele sizes determined by different laboratories, and are available upon request. Seven multiplex PCRs, each amplifying 3-5 markers, were optimized to accurately and rapidly genotype microsatellites. Parentage assignment using 10 microsatellites in two crosses (10 x 10 and 20 x 20) demonstrated a high power of these markers for revealing parent-sibling connections. This standard set of microsatellites will standardize genetic diversity studies of Asian seabass, and the multiplex PCR sets will facilitate parentage assignment.

K/pi Fluctuations at relativistic energies

We report K/pi fluctuations from Au + Au collisions at sqrt[s(NN)]= 19.6, 62.4, 130, and 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider. K/pi fluctuations in central collisions show little dependence on incident energy and are on the same order as those from NA49 at the Super Proton Synchrotron in central Pb + Pb collisions at sqrt[s(NN)]=12.3 and 17.3 GeV. We report results for the collision centrality dependence of K/pi fluctuations and results for charge-separated fluctuations. We observe that the K/pi fluctuations scale with the charged particle multiplicity density.

The metabolism of piperidine-type phenothiazine antipsychotic agents. I. Sulforidazine in the rat

1. The metabolism of the piperidine-type, phenothiazine antipsychotic agent, sulforidazine, was studied in female rats after a 20 mg/kg single oral dose. 2. Compounds identified in urine were sulforidazine, sulforidazine ring sulphoxide, the lactam of sulforidazine, the lactam of sulforidazine ring sulphoxide, two diastereomers of N-desmethylsulforidazine ring sulphoxide and a phenolic derivative of sulforidazine. 3. Metabolites were separated by h.p.l.c. prior to mass spectrometric or g.l.c.-mass spectrometric analysis. Except in the case of the phenolic metabolite, structures were confirmed by direct comparison of electron impact mass spectra and chromatographic behaviour with those of authentic samples. To facilitate identification of the phenolic metabolite the crude urinary extract was treated with a silylating reagent and analysed by h.p.l.c.-mass spectrometry with a plasmaspray interface. 4. Despite the availability of authentic standards of sulforidazine N-oxide and sulforidazine N,S-dioxide neither of these compounds could be identified in urinary extracts obtained from rats. 5. Sulforidazine underwent extensive metabolism in rats as only 2.3 +/- 0.4% (n = 5) of the dose was present as unchanged sulforidazine in 24 h urine. The lactam of sulforidazine (0.1 +/- 0.1%) was a minor metabolite whereas the lactam of sulforidazine ring sulphoxide was 3.2 +/- 2.6% dose. 6. Sulforidazine sulphoxide (12.1 +/- 1.6%) was a major metabolite and its diastereomers were present in similar amounts.

World Health Organization Sub-Types, Initial Treatment Outcome and Prognostic Study of Unselected Adult Patients with Acute Myeloid Leukaemia in Shanghai: An Analysis of 623 Cases

This study investigated the complete remission (CR) rate and survival of 623 newly diagnosed patients with acute myeloid leukaemia (AML) in Shanghai, China, classified according to World Health Organization and French–American–British criteria, and compared the differences in treatment effect with those reported in developed countries and those reported in Shanghai from 1984 to 1994. Total CR rate was 66.5%, median survival was 18 months and estimated survival at 3 years was 30.8%. The 3-year relapse rate was 55.1%. These data showed that the CR rate was similar to that achieved in studies from developed countries, but long-term survival was worse. The CR rate and survival were increased markedly compared with data previously collected in Shanghai (1984-1994). Induction chemotherapeutic regimens based on idarubicin, daunorubicin or homoharringtonine all had similar CR rates and survivals. Karyotype was the most important prognostic factor. Multilineage dysplasia in de novo AML was not an independent prognostic factor. Improvement in the long-term treatment effect in China is an important challenge for the future.