Stability and chaotification of vibration isolation floating raft systems with time-delayed feedback control

This paper presents a systematic study on the stability of a two-dimensional vibration isolation floating raft system with a time-delayed feedback control. Based on the generalized Sturm criterion, the critical control gain for the delay-independent stability region and critical time delays for the stability switches are derived. The critical conditions can provide a theoretical guidance of chaotification design for line spectra reduction. Numerical simulations verify the correctness of the approach. Bifurcation analyses reveal that chaotification is more likely to occur in unstable region defined by these critical conditions, and the stiffness of the floating raft and mass ratio are the sensitive parameters to reduce critical control gain.

Predictive potential of microsatellite markers on heterosis of fecundity in crossbred sheep

Small Tail Han (STH) sheep is a famous Chinese local breed and has perfect prolificacy performance, but it is inferior to imported mutton sheep breeds on meat production. In this study, six imported male sheep populations (White Suffolk, Black Suffolk, Texel, Dorper, South African Mutton Merino and East Friesian) were crossbred with STH female sheep respectively. The heterosis values of litter size, average daily gain (ADG) and feed conversion ratio (FCR) of crossbred sheep were analyzed for seeking the optimal cross. Meanwhile 28 microsatellite markers were used to measure the genetic distance between imported populations and STH population. Regression between the genetic distance and heterosis was analyzed for evaluating potential of microsatellite on predicting heterosis. Results showed a significant positive linear correlation (r = 0.892, P < 0.05) between heterosis of litter size and genetic distance D (A) of six crosses. This implied that these microsatellite markers had moderate potential to forecast heterosis of litter size in sheep. Results of this study also indicated that South African Mutton Merino and East Friesian sheep would be the optimal sire breeds for the litter size and might bring the greatest economic benefit in six imported populations; Suffolk sheep could be prior consideration as sire breeds when breeding objective focused on ADG. Finally these results provided valuable information for Chinese sheep industry.

Survival of Escherichia coli O157:H7 in ruminal or fecal contents incubated with corn or wheat dried distillers' grains with solubles

Dried distillers' grain with solubles (DDGS) is a by-product of ethanol production, and its use as cattle feed has increased as a result of the expansion of the fuel ethanol industry. However, the inclusion of corn DDGS into feedlot diets may increase the shedding of Escherichia coli O157:H7. This study investigated whether corn or wheat DDGS at 2 concentrations (20% or 40% vs. 100% barley grain) affected the survival of E. coli O157:H7 in incubations of ruminal digesta and feces. Neither the type nor the level of DDGS had any effect on fermentation or the survival of E. coli O157:H7 in ruminal digesta. However, there was a time by DDGS interaction (p < 0.05), where the numbers of E. coli O157:H7 in feces did not differ after 4 or 12 h of incubation but were greater after 24 h in both 40% wheat and 40% corn DDGS as compared with other treatments. Additionally, after 24 h, the numbers of E. coli O157:H7 were greater in fecal incubations with corn DDGS than with wheat DDGS (p < 0.05). The differences in the numbers of E. coli O157:H7 were not attributable to changes in pH or in concentrations of volatile fatty acids in the media. These results suggest that the inclusion of high levels of corn or wheat DDGS in feedlot diets of cattle may encourage the survival of E. coli O157:H7 in feces.

QTL consistency and meta-analysis for grain yield components in three generations in maize

Grain yield is the most important and complex trait in maize. In this study, a total of 258 F(9) recombinant inbred lines (RIL), derived from a cross between dent corn inbred Dan232 and popcorn inbred N04, were evaluated for eight grain yield components under four environments. Quantitative trait loci (QTL) and their epistatic interactions were detected for all traits under each environment and in combined analysis. Meta-analysis was used to integrate genetic maps and detected QTL across three generations (RIL, F(2:3) and BC(2)F(2)) derived from the same cross. In total, 103 QTL, 42 pairs of epistatic interactions and 16 meta-QTL (mQTL) were detected. Twelve out of 13 QTL with contributions (R(2)) over 15% were consistently detected in 3-4 environments (or in combined analysis) and integrated in mQTL. Only q100GW-7-1 was detected in all four environments and in combined analysis. 100qGW-1-1 had the largest R(2) (19.3-24.6%) in three environments and in combined analysis. In contrast, 35 QTL for 6 grain yield components were detected in the BC(2)F(2) and F(2:3) generations, no common QTL across three generations were located in the same marker intervals. Only 100 grain weight (100GW) QTL on chromosome 5 were located in adjacent marker intervals. Four common QTL were detected across the RIL and F(2:3) generations, and two between the RIL and BC(2)F(2) generations. Each of five important mQTL (mQTL7-1, mQTL10-2, mQTL4-1, mQTL5-1 and mQTL1-3) included 7-12 QTL associated with 2-6 traits. In conclusion, we found evidence of strong influence of genetic structure and environment on QTL detection, high consistency of major QTL across environments and generations, and remarkable QTL co-location for grain yield components. Fine mapping for five major QTL (q100GW-1-1, q100GW-7-1, qGWP-4-1, qERN-4-1 and qKR-4-1) and construction of single chromosome segment lines for genetic regions of five mQTL merit further studies and could be put into use in marker-assisted breeding.

Identification of differentially expressed genes at two key endosperm development stages using two maize inbreds with large and small grain and integration with detected QTL for grain weight

Maize endosperm accounts for more than 80% of the grain weight. Cell division and grain filling are the two key stages for endosperm development. Previous studies showed that gene expression during differential stages in endosperm development is greatly different. However, information on systematic identification and characterization of the differentially expressed genes between the two stages are limited. In this study, suppression subtractive hybridization (SSH) was used to generate four subtracted cDNA libraries for the two stages using two maize inbreds with large and small grain. Totally, 4,784 differentially expressed sequence tags (ESTs) were sequenced and 902 were non-redundant, which consisted of 344 unique ESTs. Among them 192 had high sequence similarity to the GenBank entries and represent diverse of functional categories, such as metabolism, cell growth/division, transcription, signal transduction, protein destination/storage, protein synthesis and others. The expression patterns of 75.7% SSH-derived cDNAs were confirmed by reverse Northern blot and semi-quantitative reverse transcription polymerase chain reaction, and exhibited the similar results (75.0%). Genes differentially expressed between two key stages for the two inbreds were involved in diverse physiological process pathway, which might be responsible for the formation of grain weight. 43.8% (70 of the 160 unique ESTs) of the identified ESTs were assigned to 39 chromosome bins distributed over all ten maize chromosomes. Eleven ESTs were found to co-localize with previous detected QTLs for grain weight, which might be considered as the candidate genes of grain weight for further study.

Ferroelastic switching for nanoscale non-volatile magnetoelectric devices

Multiferroics, where (anti-) ferromagnetic, ferroelectric and ferroelastic order parameters coexist, enable manipulation of magnetic ordering by an electric field through switching of the electric polarization. It has been shown that realization of magnetoelectric coupling in a single-phase multiferroic such as BiFeO(3) requires ferroelastic (71 degrees, 109 degrees) rather than ferroelectric (180 degrees) domain switching. However, the control of such ferroelastic switching in a single-phase system has been a significant challenge as elastic interactions tend to destabilize small switched volumes, resulting in subsequent ferroelastic back-switching at zero electric field, and thus the disappearance of non-volatile information storage. Guided by our phase-field simulations, here we report an approach to stabilize ferroelastic switching by eliminating the stress-induced instability responsible for back-switching using isolated monodomain BiFeO(3) islands. This work demonstrates a critical step to control and use non-volatile magnetoelectric coupling at the nanoscale. Beyond magnetoelectric coupling, it provides a framework for exploring a route to control multiple order parameters coupled to ferroelastic order in other low-symmetry materials.

The protective effects of Acanthopanax senticosus Harms aqueous extracts against oxidative stress: role of Nrf2 and antioxidant enzymes

ETHNOPHARMACOLOGICAL RELEVANCE

Acanthopanax senticosus (Rupr.et Maxim.) Harms, classified into the family of Araliaceae, is used in a variety of diseases in traditional Chinese system of medicine including hypertension, ischemic heart disease and hepatitis.

MATERIALS AND METHODS

Different doses (75 mg/kg, 150 mg/kg and 300 mg/kg) of aqueous extracts of Acanthopanax senticosus Harms were evaluated for the antioxidant activity against oxidative stress in mice induced by tert-butyl hydroperoxide (t-BHP) through observating histopathology of the liver and detecting antioxidant enzyme activity, concentration of antioxidant, and related gene and protein expression.

RESULTS

Acanthopanax senticosus Harms aqueous extracts (ASE) attenuated the morphological injury of liver induced by t-BHP and increased the activity of antioxidant enzymes and the ratio of GSH/GSSG in serum and liver homogenates. Medium and high doses of ASE also elevated the gene expression of NF-E2-related factor-2 (Nrf2), but not CuZnSOD, MnSOD, catalase (CAT), glutathione peroxidase (GPx) and GCLC. Protein expression results showed that Nrf2 and the antioxidant enzymes were all increased significantly by medium and high doses of ASE.

CONCLUSION

The present results indicated that ASE protect against oxidative stress which may be generated via the induction of Nrf2 and related antioxidant enzymes.

Evaluation of heterogeneous photo-Fenton oxidation of Orange II using response surface methodology

A mesoporous SBA-15 doped iron oxide (Fe2O3/SBA-15) was synthesized by co-condensation, characterized and used as heterogeneous catalysts for the photo-Fenton decolorization of azo dye Orange II under UV irradiation. Response surface methodology (RSM) was used to investigate operating condition effects, such as hydrogen peroxide concentration, initial pH and catalyst loadings, on the decolorization rate. UV irradiation is found to enhance the activity of the catalyst in the process. RSM analysis evidenced the influence of the initial pH value and H2O2 concentration on the dye degradation rate. The coupled UV/Fe2O3/SBA-15/H2O2 process at room temperature is revealed as a promising friendly process for wastewater treatment. Indeed, the use of a heterogeneous catalyst allows an easy active phase recycling without multi-step recovering while the heterogeneous catalyst used here exhibits high catalytic activity for the reaction considered.

Ferroelectricity in ultrathin BaTiO3 films: probing the size effect by ultraviolet Raman spectroscopy

We demonstrate the dramatic effect of film thickness on the ferroelectric phase transition temperature Tc in strained BaTiO3 films grown on SrTiO3 substrates. Using variable-temperature ultraviolet Raman spectroscopy enables measuring Tc in films as thin as 1.6 nm, and a film thickness variation from 1.6 to 10 nm leads to Tc tuning from 70 to about 925 K. Raman data are consistent with synchrotron x-ray scattering results, which indicate the presence of 180 degrees domains below Tc, and thermodynamic phase-field model calculations of Tc as a function of thickness.

Diabetes alters protein expression of hyperpolarization-activated cyclic nucleotide-gated channel subunits in rat nodose ganglion cells

Vagal afferent neurons, serving as the primary afferent limb of the parasympathetic reflex, could be involved in diabetic autonomic neuropathy. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed in the vagal afferent neurons and play an important role in determining cell membrane excitation. In the present study, the protein expression and the electrophysiological characteristics of HCN channels were investigated in nodose ganglion (NG) afferent neurons (A-fiber and C-fiber neurons) from sham and streptozotocin (STZ)-induced diabetic rats. In the sham NG, HCN1, HCN3, and HCN4 were expressed in the A-fiber neurons; and HCN2, HCN3, and HCN4 were expressed in the C-fiber neurons. Compared to the sham NG neurons, diabetes induced the expression of HCN2 in the A-fiber neurons besides overexpression of HCN1 and HCN3; and enhanced the expression of HCN2 and HCN3 in C-fiber neurons. In addition, whole-cell patch-clamp data revealed diabetes also increased HCN currents in A-fiber and C-fiber neurons. However, we found that diabetes did not alter the total nodose afferent neuron number and the ratio of A-fiber/C-fiber neurons. These results indicate that diabetes induces the overexpression of HCN channels and the electrophysiological changes of HCN currents in the A- and C-fiber nodose neurons, which might contribute to the diabetes-induced alteration of cell excitability in the vagal afferent neurons.

Development of an enzyme-linked immunosorbent assay for the alpha-cyano pyrethroids multiresidue in Tai lake water

A general and broad class selective competitive enzyme-linked immunosorbent assay (ELISA) for the detection of the alpha-cyano pyrethroids was developed. One class specific hapten, the 5-(3-benzylphenyl)-5-cyanopentanoic acid (CPBA-BE), was conjugated with BSA as an immunogen. Polyclonal antibodies, PY-antibodies, were generated. The assay with the most selectivity for the family alpha-cyano pyrethroids such as cyphenothrin was further optimized and tested for tolerance to cosolvent, pH, and ionic strength changes. The IC(50) values of the optimized immunoassay were 4.58 microg L(-1) for cyphenothrin, 5.62 microg L(-1) for fenpropathrin, 7.08 microg L(-1) for deltamethrin, 10.72 microg L(-1) for cypermethrin, 19.95 microg L(-1) for flucythrinate, and 28.18 microg L(-1) for esfenvalerate. The cross-reactivities of cyphenothrin, fenpropathrin, deltamethrin, cypermethrin, flucythrinate, and esfenvalerate were 100%, 81.49%, 64.68%, 42.72%, 22.96%, and 16.25%, respectively. The low detection limit (LDL) of this assay was 0.107 microg L(-1) for cyphenothrin. This method was used for the detection of the alpha-cyano pyrethroids in Tai lake water.

Formation of nanocrystalline copolymer thin film PVDF-TrFE and its ferroelectric electron emission property

Ferroelectric copolymer thin film PVDF-TrFE was deposited by spin coating method, and then annealed for the improved crystallization. The XRD and AFM measurements showed that as-formed PVDF-TrFE thin film was composed of the nanocrystallines with 50-80 nm in size and some amorphous phases. Meanwhile, as-formed PVDF-TrFE thin films also show a good polarization inversion property with a switch current of approximately 2.0 microA at a coercive field 40 MV/m. Electron emission testing results showed that under a continuous excitation of applied voltage pulses, PVDF-TrFE thin films exhibited an expected electron emission ability with emission current range of 0.08-0.52 microA, and the related electron emission mechanism was discussed.

Identification of trait-improving quantitative trait loci for grain yield components from a dent corn inbred line in an advanced backcross BC2F2 population and comparison with its F2:3 population in popcorn

Normal maize germplasm could be used to improve the grain yield of popcorn inbreds. Our first objective was to locate genetic factors associated with trait variation and make first assessment on the efficiency of advanced backcross quantitative trait locus (AB-QTL) analysis for the identification and transfer of favorable QTL alleles for grain yield components from the dent corn inbred. A second objective was to compare the detection of QTL in the BC2F2 population with results using F(2:3) lines of the same parents. Two hundred and twenty selected BC2F2 families developed from a cross between Dan232 and an elite popcorn inbred N04 were evaluated for six grain yield components under two environments, and genotyped by means of 170 SSR markers. Using composite interval mapping (CIM), a total of 19 significant QTL were detected. Eighteen QTL had favorable alleles contributed by the dent corn parent Dan232. Sixteen of these favorable QTL alleles were not in the same or near marker intervals with QTL for popping characteristics. Six QTL were also detected in the F(2:3) population. Improved N04 could be developed from 210 and 208 families with higher grain weight per plant and/or 100-grain weight, respectively, and 35 families with the same or higher popping expansion volume than N04. In addition, near isogenic lines containing detected QTL (QTL-NILs) for grain weight per plant and/or 100-grain weight could be obtained from 12 families. Our study demonstrated that the AB-QTL method can be applied to identify and manipulate favorable QTL alleles from normal corn inbreds and combine QTL detection and popcorn breeding efficiently.

Identification of trait-improving quantitative trait loci for grain yield components from a dent corn inbred line in an advanced backcross BC2F2 population and comparison with its F2:3 population in popcorn

Normal maize germplasm could be used to improve the grain yield of popcorn inbreds. Our first objective was to locate genetic factors associated with trait variation and make first assessment on the efficiency of advanced backcross quantitative trait locus (AB-QTL) analysis for the identification and transfer of favorable QTL alleles for grain yield components from the dent corn inbred. A second objective was to compare the detection of QTL in the BC2F2 population with results using F(2:3) lines of the same parents. Two hundred and twenty selected BC2F2 families developed from a cross between Dan232 and an elite popcorn inbred N04 were evaluated for six grain yield components under two environments, and genotyped by means of 170 SSR markers. Using composite interval mapping (CIM), a total of 19 significant QTL were detected. Eighteen QTL had favorable alleles contributed by the dent corn parent Dan232. Sixteen of these favorable QTL alleles were not in the same or near marker intervals with QTL for popping characteristics. Six QTL were also detected in the F(2:3) population. Improved N04 could be developed from 210 and 208 families with higher grain weight per plant and/or 100-grain weight, respectively, and 35 families with the same or higher popping expansion volume than N04. In addition, near isogenic lines containing detected QTL (QTL-NILs) for grain weight per plant and/or 100-grain weight could be obtained from 12 families. Our study demonstrated that the AB-QTL method can be applied to identify and manipulate favorable QTL alleles from normal corn inbreds and combine QTL detection and popcorn breeding efficiently.

Measurements of the continuum R(uds) and R values in e(+)e(-) annihilation in the energy region between 3.650 and 3.872 GeV

We report measurements of the continuum R(uds) near the center-of-mass energy of 3.70 GeV, the R[uds(c)+psi(3770)](s) and the R(had)(s) values in e(+)e(-) annihilation at 68 energy points in the energy region between 3.650 and 3.872 GeV with the BES-II detector at the BEPC Collider. We obtain the R(uds) for the continuum light hadron (containing u, d, and s quarks) production near the DD threshold to be R(uds)=2.141+/-0.025+/-0.085.

Multiferroic domain dynamics in strained strontium titanate

Multiferroicity can be induced in strontium titanate by applying biaxial strain. Using optical second harmonic generation, we report a transition from 4/mmm to the ferroelectric mm2 phase, followed by a transition to a ferroelastic-ferroelectric mm2 phase in a strontium titanate thin film. Piezoelectric force microscopy is used to study ferroelectric domain switching. Second harmonic generation, combined with phase-field modeling, is used to reveal the mechanism of coupled ferroelectric-ferroelastic domain wall motion. These studies have relevance to multiferroics with coupled polar and axial phenomena.

Search for invisible decays of eta and eta' in J/psi --> phi eta and phi eta'

Using a data sample of 58 x 10(6) J/psi decays collected with the Beijing Spectrometer II detector at the Beijing Electron Positron Collider, searches for invisible decays of eta and eta' in J/psi to phi eta and phi eta' are performed. The phi signals, which are reconstructed in K+K- final states, are used to tag the eta and eta' decays. No signals are found for the invisible decays of either eta or eta', and upper limits at the 90% confidence level are determined to be 1.65 x 10(-3) for the ratio B(eta-->invisible)/B(eta --> gamma gamma) and 6.69 x 10(-2) for B(eta' --> invisible)/B(eta' --> gammagamma). These are the first searches for eta and eta' decays into invisible final states.

Observation of a broad 1-- resonant structure around 1.5 GeV/c2 in the K+K- mass spectrum in J/psi-->K+K-pi0

A broad peak is observed at low K+K- invariant mass in J/psi-->K+K-pi(0) decays found in a sample of 5.8x10(7) J/psi events collected with the BESII detector. The statistical significance of the broad resonance is much larger than 5sigma. A partial wave analysis shows that the J;{PC} of this structure is 1--. Its pole position is determined to be [1576(-55)(+49)(stat)-91+98(syst)] MeV/c(2)-i/2[818(-23)(+22)(stat)-133+64(syst)] MeV/c(2). These parameters are not compatible with any known meson resonances.

Fifth-Order Raman Spectroscopy of Liquid Benzene: Experiment and Theory

The heterodyned fifth-order Raman response of liquid benzene has been measured and characterized by exploiting the passive-phase stabilization of diffractive optics. This result builds on our previous work with liquid carbon disulfide and extends the spectroscopy to a new liquid for the first time. The all-parallel and Dutch Cross polarization tensor elements are presented for both the experimental results and a finite-field molecular dynamics simulation. The overall response characteristics are similar to those of liquid carbon disulfide: a complete lack of signal along the pump delay, an elongated signal along the probe delay, and a short-lived signal along the time diagonal. Of particular interest is the change in phase between the nuclear and electronic response along the probe delay and diagonal which is not seen in CS2. Good agreement is achieved between the experiment and the finite-field molecular dynamics simulation. The measurement of the low-frequency Raman two-time delay correlation function indicates the intermolecular modes of liquid benzene to be primarily homogeneously broadened and that the liquid loses its nuclear rephasing ability within 300 fs. This rapid loss of nuclear correlations indicates a lack of modal character in the low-frequency motions of liquid benzene. This result is a validation of the general nature of the technique and represents an important step forward with respect to the use of nonlinear spectroscopy to directly access information on the anharmonic motions of liquids.

Measurements of the branching fractions for psi(3770)-->D(0)D[over ](0), D+D-, DD[over ], and the resonance parameters of psi(3770) and psi(2S)

We measure the branching fractions for psi(3770)-->D(0)D[over ](0), D+D-, DD[over ], and non-DD[over ] to be (46.7+/-4.7+/-2.3)%, (36.9+/-3.7+/-2.8)%, (83.6+/-7.3+/-4.2)%, and (16.4+/-7.3+/-4.2)%, respectively. The resonance parameters of psi(3770) and psi(2S) are measured to be M_(psi(3770))=3772.2+/-0.7+/-0.3 MeV, Gamma_(psi(3770))(tot)=26.9+/-2.4+/-0.3 MeV, and Gamma_(psi(3770))(ee)=251+/-26+/-11 eV; M_(psi(2S))=3685.5+/-0.0+/-0.3 MeV, Gamma_(psi(2S))(tot)=331+/-58+/-2 keV, and Gamma_(psi(2S))(ee)=2.330+/-0.036+/-0.110 keV. We also measure the light hadron R value to be R(uds)=2.262+/-0.054+/-0.109 in the energy region from 3.660 to 3.872 GeV.

Probing Nanoscale Ferroelectricity by Ultraviolet Raman Spectroscopy

We demonstrated that ultraviolet Raman spectroscopy is an effective technique to measure the transition temperature (Tc) in ferroelectric ultrathin films and superlattices. We showed that one-unit-cell-thick BaTiO3 layers in BaTiO3/SrTiO3 superlattices are not only ferroelectric (with Tc as high as 250 kelvin) but also polarize the quantum paraelectric SrTiO3 layers adjacent to them. Tc was tuned by approximately 500 kelvin by varying the thicknesses of the BaTiO3 and SrTiO3 layers, revealing the essential roles of electrical and mechanical boundary conditions for nanoscale ferroelectricity.

Observation of a near-threshold enhancement in the omega(phi) mass spectrum from the doubly OZI-suppressed decay J/psi-->gamma(omega)phi

An enhancement near threshold is observed in the omega(phi) invariant mass spectrum from the doubly Okubo-Zweig-Iizuka-suppressed decays of J/psi-->gamma(omega)phi, based on a sample of 5.8 x 10(7) J/psi events collected with the BESII detector. A partial wave analysis shows that this enhancement favors JP=0+, and its mass and width are M=1812(+19)(-26)(stat)+/-18(syst) MeV/c2 and Gamma=105+/-20(stat)+/-28(syst) MeV/c2. The product branching fraction is determined to be B(J/psi-->gammaX)B(X-->omega(phi))=[2.61+/-0.27(stat)+/-0.65(syst)]x10(-4).

Heparin-coupled poly(poly(ethylene glycol) monomethacrylate)-Si(111) hybrids and their blood compatible surfaces

Well-defined (nearly monodispersed) poly(poly(ethylene glycol)monomethacrylate)-Si hybrids were prepared via surface-initiated atom transfer radical polymerization (ATRP) of the poly(ethylene glycol)monomethacrylate (PEGMA) macromonomer on the hydrogen-terminated Si(111) surface (Si-H surface). Both the active chloride groups at the chain ends (from the ATRP process) and the chloride groups converted from some ( approximately 32%) of the -OH groups of the Si-C bonded PEGMA polymer, or P(PEGMA), brushes were used as leaving groups for the covalent coupling of heparin. For the heparinized P(PEGMA)-Si hybrid surfaces, protein adsorption and platelet adhesion were significantly suppressed. The well-defined and dense P(PEGMA) brushes, prepared from surface-initiated ATRP, had allowed the immobilization of a relatively high concentration of heparin (about 14 mug/cm(2)). The resulting silicon surface exhibited significantly improved antithrombogenecity with a plasma recalcification time (PRT) of about 150 min. The persistence of high bioactivity for the immobilized heparin on the hybrid surfaces can be attributed to the biocompatibility of the PEGMA units, as well as their role as spacers in providing the immobilized heparin with a higher degree of conformational freedom in a more hydrophilic environment. Thus, the heparin-coupled P(PEGMA)-Si hybrids with anti-fouling and antithrombogenic surfaces are potentially useful in silicon-based implantable devices and tissue engineering.

Observation of a resonance in Chi(1835) in J/psi --> gammapi+ pi- eta-

The decay channel J/psi --> gamma(pi)(+)pi(-)eta is analyzed using a sample of 5.8 x 10(7) J/psi events collected with the BESII detector. A resonance, the Chi(1835), is observed in the pi(+)pi(-)eta invariant-mass spectrum with a statistical significance of 7.7 sigma. A fit with a Breit-Wigner function yields a mass M = 1833.7 +/- 6.1(stat) +/- 2.7(syst) MeV/c(2), a width Tau = 67.7 +/- 20.3(stat) +/- 7.7(syst) MeV/c(2), and a product branching fraction B(J/psi --> gammaChi) . B(Chi --> pi(+)pi(-)eta) = [2.2 +/- 0.4(stat) +/- 0.4(syst)] x 10(-4). The mass and width of the Chi(1835) are not compatible with any known meson resonance. Its properties are consistent with expectations for the state that produces the strong pp mass threshold enhancement observed in the J/psi --> gammapp process at BESII.

Vaccination of mice with DNA vaccine induces the immune response and partial protection against T. spiralis infection

Trichinellosis is a serious parasitic zoonosis which is widely distributed in the world. Pork still is the predominant source of outbreaks of human trichinellosis in many countries. Vaccines are urgently needed to prevent swine from Trichinella infection. The gene (TspE1) encoding a 31 kDa antigen of T. spiralis was cloned to a eukaryotic expression plasmid pcDNA3 as DNA vaccine. The ability of the DNA vaccine to express antigen in mammalian CHO cells was previously confirmed by indirect fluorescencent antibody test (IFAT) and Western blotting. To evaluate its immunogenicity and its host protective potential, BALB/c mice were immunized with the DNA vaccine by intramuscular injection and gene-gun delivery. The serum antibody response was assayed by IFAT, enzyme linked immunosorbant assay (ELISA) and Western blotting. The cellular immune response was investigated by splenocyte proliferation assay. Vaccine administration by either route induced both humoral and cellular immune response against TspE1, which provided the partial protection against challenge infection with T. spiralis, as shown by significant reduction of larval burden in muscles. Thus, DNA immunization may offer an attractive alternative strategy against swine trichinellosis.

Covalent Immobilization of Glucose Oxidase on Well-Defined Poly(glycidyl methacrylate)−Si(111) Hybrids from Surface-Initiated Atom-Transfer Radical Polymerization

A simple one-step procedure was employed for the covalent immobilization of an atom-transfer radical polymerization (ATRP) initiator, via the robust Si-C bond, on the hydrogen-terminated Si(111) surface (Si-H surface). Well-defined poly(glycidyl methacrylate) [P(GMA)] brushes, tethered directly on the (111)-oriented single-crystal silicon surface, were prepared via surface-initiated ATRP. Kinetics study on the surface-initiated ATRP of glycidyl methacrylate revealed that the chain growth from the silicon surface was consistent with a "controlled" process. A relatively high concentration of glucose oxidase (GOD; above 0.2 mg/cm2) could be coupled directly to the well-defined P(GMA) brushes via the ring-opening reaction of the epoxide groups with the amine moieties of the enzyme. The resultant GOD-functionalized P(GMA) brushes, with the accompanying hydroxyl groups from the ring-opening reaction of the epoxide groups, serves as an effective spacer to provide the GOD with a higher degree of conformational freedom and a more hydrophilic environment. An equivalent enzyme activity above 1.6 units/cm2 [micromoles of beta-D-(+)-glucose oxidized to d-gluconolactone per minute per square centimeter] and a corresponding relative activity of about 60% could be readily achieved. The immobilized GOD also exhibited an improved stability during storage over that of the free enzyme. The GOD-functionalized silicon substrates are potentially useful to the development of silicon-based glucose biosensors.

Enhancement of ferroelectricity in strained BaTiO3 thin films

Biaxial compressive strain has been used to markedly enhance the ferroelectric properties of BaTiO3 thin films. This strain, imposed by coherent epitaxy, can result in a ferroelectric transition temperature nearly 500 degrees C higher and a remanent polarization at least 250% higher than bulk BaTiO3 single crystals. This work demonstrates a route to a lead-free ferroelectric for nonvolatile memories and electro-optic devices.

Room-temperature ferroelectricity in strained SrTiO3

Systems with a ferroelectric to paraelectric transition in the vicinity of room temperature are useful for devices. Adjusting the ferroelectric transition temperature (T(c)) is traditionally accomplished by chemical substitution-as in Ba(x)Sr(1-x)TiO(3), the material widely investigated for microwave devices in which the dielectric constant (epsilon(r)) at GHz frequencies is tuned by applying a quasi-static electric field. Heterogeneity associated with chemical substitution in such films, however, can broaden this phase transition by hundreds of degrees, which is detrimental to tunability and microwave device performance. An alternative way to adjust T(c) in ferroelectric films is strain. Here we show that epitaxial strain from a newly developed substrate can be harnessed to increase T(c) by hundreds of degrees and produce room-temperature ferroelectricity in strontium titanate, a material that is not normally ferroelectric at any temperature. This strain-induced enhancement in T(c) is the largest ever reported. Spatially resolved images of the local polarization state reveal a uniformity that far exceeds films tailored by chemical substitution. The high epsilon(r) at room temperature in these films (nearly 7,000 at 10 GHz) and its sharp dependence on electric field are promising for device applications.

Regulatory role of extracellular matrix components in expression of matrix metalloproteinases in cultured hepatic stellate cells

Hepatic stellate cells (HSCs) were changed in their morphology, proliferative activity, and functions by culturing on type I collagen gel, as compared to the culture on polystyrene surface. HSCs have been found to produce extracellular matrix components and matrix metalloproteinases (MMPs). In this study, we have assessed the effects of several types of substrata on the expression of MMPs in HSC culture. MMP-1 expression was detectable in HSC culture on polystyrene surface and on type I collagen gel by immunofluorescence staining and reverse transcriptase-polymerase chain reaction (RT-PCR). The results from in situ zymography revealed the presence of interstitial collagenase activity around HSCs and along their cellular processes. Although proMMP-2 and proMMP-9 were detectable by gelatin zymography in the conditioned medium from both cultures using type I collagen gel and Matrigel as substratum, an active form of MMP-2 but not of MMP-9 was detected only in the culture using type I collagen as a substratum. Tissue inhibitor of metalloproteinase-2 expression was observed by RT-PCR in HSCs cultured on or in type I collagen gel, suggesting the suppression of MMP-2 activity detected in HSC culture using type I collagen. These results indicate a differential expression of MMP activity, hence the remodeling of extracellular matrix components is dependent on the substratum used for HSC culture. The HSC culture using several types of substrata appears to be a useful in vitro model to study the mechanism of extracellular matrix remodeling.

Comparison of H2-Receptor Antagonist-and Proton-Pump Inhibitor-Based Triple Regimens for the Eradication of Helicobacter Pylori in Chinese Patients with Gastritis or Peptic Ulcer

This study compared the efficacy of an H2-receptor antagonist (H2RA)- and a proton-pump inhibitor (PPI)-based triple regimen for the eradication of Helicobacter pylori infection. Chinese patients with H. pylori-associated gastritis or peptic ulcer were randomized to receive the H2RA-based triple regimen (20 mg famotidine, 1.0 g amoxicillin and 0.4 g metronidazole) or the PPI-based triple regimen (20 mg omeprazole, 1.0 g amoxicillin and 0.4 g metronidazole) both twice daily for 1 or 2 weeks. Successful eradication of H. pylori was determined by the 13C-urea breath test and gastric mucosa histology at least 4 weeks after completion of antibiotic therapy. Eradication rates were 56.0% and 76.9% for the 1-week H2RA- and PPI-based triple regimens, respectively, and 81.6% and 82.1% for the 2-week regimens, respectively. The H. pylori eradication rate for the 2-week H2RA regimen was significantly higher than that for the 1-week regimen, but there were no significant differences between the 1- and 2-week PPI regimens. The two regimens proved equally effective in eradicating H. pylori infection.

Genetic Diversity and Background Linkage Disequilibrium in the North American Holstein Cattle Population

The objectives of this study were to 1) identify highly heterozygous Holstein bulls that are as unrelated as possible and widely used in the US dairy industry; 2) quantify the level of genetic diversity in US Holsteins; and 3) determine the extent of background linkage disequilibrium (BLD) and disease trait associated linkage disequilibrium (DLD) in the US Holstein population. Twenty-three Holstein bulls that are not closely related but were widely used in the US dairy industry were genotyped for 54 microsatellite loci. The genotyping was performed on automated DNA sequencers (PE Applied Biosystems, CA), following polymerase chain reaction amplification with fluorescent dye-labeled primers. The heterozygosity for the sampled population ranged from 0.43 to 0.80. This wide range of heterozygosity allows selection of the most heterozygous bulls to develop informative families for gene mapping studies. The degree of genetic diversity in this population is significant and allows selection for traits of economic importance. As expected, there is extensive linkage disequilibrium (LD) in the US Holstein population. About half of the syntenic marker pairs presented a typical pattern of LD produced by DLD. Most of the nonsyntenic marker pairs had a typical pattern of LD arising from BLD. These results suggest that the observed LD is not purely due to genetic drift and migration and that a portion might be due to DLD. This raises our hopes of successful fine-localization of genes for complex traits using LD mapping.

Rapid Identification of Yeasts Commonly Found in Positive Blood Cultures by Amplification of the Internal Transcribed Spacer Regions 1 and 2

A multiplex PCR method using one universal and eight species-specific primers was developed to rapidly identify eight yeast species found in positive blood cultures. The species-specific primers were designed from the internal transcribed spacer regions 1 and 2 of the rRNA gene, whereas the universal primer was located at the 26S rRNA gene. The eight species were Candida albicans, Candida glabrata, Candida guilliermondii, Candida krusei, Candida lusitaniae, Candida parapsilosis, Candida tropicalis, and Cryptococcus neoformans. The PCR products (116 to 630 bp) were different in length and could be effectively separated and recognized by polyacrylamide gel electrophoresis. By testing 234 positive blood cultures (237 isolates), 234 (98.7%) isolates of the above eight species were correctly identified by the multiplex PCR. The present method is simple to perform and can be completed within 6 h.

[Studies on the activity and immunohistochemistry of heme oxygenase in Schistosoma japonicum]

OBJECTIVE

To explore the activity of heme oxygenase and immunolocate the enzyme in the adult worms of Schistosoma japonicum.

METHODS

Microsomal protein was isolated from the homogenate of adult S. japonicum, heme degradation and effect of different pH conditions and buffers on degrading reaction were investigated by incubating microsomal protein with hemin. The slices of whole worm and cells of S. japonicum were prepared, distribution of HO in schistosome was studied by immunofluorescent and alkaline phosphatase(AP)-immunocytochemical assays.

RESULTS

Microsomal protein of adult worms can degrade the heme in vitro, the activity being 56.7 nmol bilirubin/(mg.min). The optimal pH was 8.7. Immunofluorescent and AP-immunocytochemical assays revealed that the HO distributed dispersively in the worm, and located in cytoplasm.

CONCLUSION

The presence of HO was firstly proved in S. japonicum.

[Studies on apoptosis and its induction in Schistosoma japonicum]

OBJECTIVE

To explore the apoptosis and its induction in S. japonicum.

METHODS

The eggs and adult cells of S. japonicum were isolated. The adult cells were incubated with H2O2, dexamethasone and cyclosporin A, cyclosporin A vehicle solution, respectively in order to initiate the apoptosis. The eggs were treatd at 4 degrees C, 37 degrees C and 42 degrees C, respectively for induction of apoptosis. The occurrence of apoptosis was supervised by agarose gel electrophoresis and in situ end labelling.

RESULTS

DNA ladder-band characteristic of apoptosis appeared in the cells of adult worms after incubated with H2O2, dexamethasone or cyclosporin A and the eggs treated at 42 degrees C, whereas no DNA ladder band was found in other control groups. In situ end labeling revealed that the positive fluorescence could be seen in the cells incubated with H2O2, dexamethasone or cyclosporin A and few nuclei in the control group and cyclosporin A vehicle solution group appeared positive fluorescence.

CONCLUSION

Apoptosis in the cells of S. japonicum adults and eggs induced by chemical or physical agents was observed.

TECA hybrid artificial liver support system in treatment of acute liver failure

AIM: To assess the efficacy and safety of TECA type hybr id artificial liver support system (TECA-HALSS) in providing liver function of detoxification, metabolism and physiology by treating the patients with acute liv er failure (ALF).

METHODS: The porcine liver cells (1-2) × 10¹⁰ were separated from the Chinese small swine and cultured in the bioreactor of TECA-BALSS at 37.0 °C and circulated through the outer space of the hollow fiber tubes in BALSS. The six liver failure patients with various degree of hepatic coma were treated by TECA-HALSS and with conventional medicines. The venous plasma of the patients was separated by a plasma separator and treated by charcoal adsorbent or plasma exchange. The plasma circulated through the inner space of the hollow fiber tubes of BALSS and mixed with the patients’ blood cells and flew back to their blood circulation. Some small molecular weight substances were exchanged between the plasma and porcine liver cells. Each treatment lasted 6.0-7.0 h. Physiological and biochemical parameters were measured before, during and after the treatment.

RESULTS: The average of porcine liver cells was (1.0-3.0) × 10¹⁰ obtained from each swine liver using our modified enzymatic digestion method. The survival rate of the cells was 85%-93% by trypan blue stain and AO/PI fluorescent stain. After cultured in TECA-BALSS bioreactor for 6 h, the survival rate of cells still remained 70%-85%. At the end of TECA-HALSS treatment, the levels of plasma NH₃, ALT, TB and DB were significantly decreased. The patients who were in the state of drowsiness or coma before the treatment improved their appetite significantly and regained consciousness, some patients resumed light physical work on a short period after the treatment. One to two days after the treatment, the ratio of PTA increased warkedly. During the treatment, the heart rates, blood pressure, respiration condition and serum electrolytes (K⁺, Na⁺ and Cl^-) were stable without thrombosis and bleeding in all the six patients.

CONCLUSION: TECA-HALSS treatment could be a rapid, safe and efficacious method to provide temporary liver support for patients with ALF.

Impairment of endothelial function after a high-fat meal in patients with coronary artery disease

OBJECTIVE

To determine the effect of postprandial lipid changes on endothelial function in patients with coronary artery disease (CAD) after a high-fat meal.

METHODS

We studied 50 CAD patients and 25 control participants, who were all normocholesterolemic. Flow-mediated vasodilatation of the brachial artery was evaluated by the high-resolution ultrasound technique before and after a single high-fat meal (800 calories; 50 g fat).

RESULTS

Postprandial serum triglyceride level increased significantly at 2-7 h and mean flow-mediated vasodilatation was impaired significantly (from 4.22 +/- 0.44 to 2.75 +/- 0.33%, P < 0.01) for 75 subjects. The increment in 2 h serum triglyceride level correlated positively with the decrement in postprandial flow-mediated vasodilatation (r = 0.459, P < 0.01). Postprandial triglyceride level was significantly higher in CAD patients than in control participants. Flow-mediated vasodilatation was significantly impaired in CAD patients (from 3.04 +/- 0.39 to 1.69 +/- 0.23%, P < 0.01) and control participants (from 6.58 +/- 0.52 to 4.87 +/- 0.19%, P < 0.05) after a high-fat meal. The impairment of flow-mediated dilatation was more severe in CAD patients (44.41%) than in control participants (25.99%, P < 0.01).

CONCLUSION

Postprandial endothelium-dependent vasodilatation after a single high-fat meal was severely impaired in normocholesterolemic CAD patients and control participants. The disordered postprandial metabolism of triglyceride-rich lipoproteins may play an atherogenic role by inducing endothelial dysfunction.

Experimental research on TECA-I bioartificial liver support system to treat canines with acute liver failure

AIM: To evaluate the efficacy and safety of the TECA-I bioartificial liver support system (BALSS) in treating canines with acute liver failure (ALF).

METHODS: Ten canines with ALF induced by 80% liver resection received BALSS treatment (BALSS group). Blood was perfused through a hollow fiber tube containing 1 × 10¹⁰ porcine hepatocytes. Four canines with ALF were treated with BALSS without porcine hepatocytes (control group), and five canines with ALF received drug treatment (drug group). Each treatment lasted 6 h.

RESULTS: BALSS treatment yielded beneficial effects for partial liver resection-induced ALF canines with survival and decreased plasma ammonia, ALT, AST and BIL. There was an obvious decrease in PT level and increase in PA level, and there were no changes in the count of lymphocytes, immunoglobulins (IgA, IgG and IgM) and complement (C3 and C4) levels after BALSS treatment. In contrast, for the canines with ALF in non-hepatocyte BALSS group (control group) and drug group, there were no significant changes in ammonia, ALT, AST, BIL, PT and PA levels. ALF canines in BALSS group, control group and drug group lived respectively an average time of 108.0 h ± 12.0 h, 24.0 h ± 6.0 h and 20.4 h ± 6.4 h, and three canines with ALF survived in BALSS group.

CONCLUSION: TECA-I BALSS is efficacious and safe for ALF canines induced by parcial liver resection.

Infection induces antibodies against the cercarial secretions, but not against the cercarial elastases of Schistosoma mansoni, Schistosoma haematobium, Schistosoma japonicum and Trichobilharzia ocellata

Cercarial secretions from different species of the parasite Schistosoma and from Trichobilharzia ocellata contain a proteolytic activity, cercarial elastase, which was demonstrated by a 30 kDa band in gelatin gels. Sera of patients infected with Schistosoma mansoni, Schistosoma haematobium or Schistosoma japonicum contain immunoglobulin G which react in ELISA with cercarial secretions from all schistosomes and cross-react among the different parasite species. In Western blots, however, infection sera from patients, as well as heavily infected mice or rabbits, did not react with a 30-kDa protein. Moreover, when sections from infected snails (Biomphalaria, Bulinus and Lymnaea) were analysed by immunofluorescence using the same infection sera, only the tegument of the developing cercariae was recognized, but not the acetabular glands. In contrast, when antisera against purified cercarial elastase from either S. mansoni or S. haematobium were tested with sections of infected Biomphalaria or Bulinus, fluorescence was strong in the preacetabular glands of the cercariae of either species, but undetectable with the tegument. Cross-reactivity of both antisera extended to T. ocellata-infected Lymnaea, but not to S. japonicum-infected Oncomelania. In conclusion, although immunization with purified cercarial elastase results in antibody production, the enzyme does not induce an apparent antibody response following natural infection.

GSTP1 polymorphisms and gastric cancer in a high-risk Chinese population

OBJECTIVES

In a population-based case-control study in Yangzhong, China, we investigated the relationship between genetic polymorphisms of GSTP1 and susceptibility to gastric cancer and its premalignant lesion, chronic gastritis. The possible gene-gene interactions between GSTP1 polymorphisms and GSTM1, GSTT1 genes were explored.

METHODS

Epidemiologic data were collected by standard questionnaire from 133 gastric cancer cases, 166 chronic gastritis cases, and 433 cancer-free population controls. Blood samples for Helicobacter pylori and molecular marker assays were collected from 84 gastric cancer cases, 146 chronic gastritis, and 429 population controls. GSTP1 polymorphisms were determined by the PCR-RFLP method and H. pylori infection was measured by the ELISA method. Associations between certain GSTP1 genotypes and both gastric cancer and chronic gastritis were assessed by odds ratios (ORs) and 95% confidence intervals (CIs) derived from logistic regression.

RESULTS

The distributions of three GSTP1 genotypes, Ile/Ile, Ile/Val, and Val/Val, were similar in gastric cancer cases, chronic gastritis, and controls. After adjusting for age, gender, education, body mass index, pack-year of smoking, alcohol drinking, H. pylori infection, salt and fruit intakes, the adjusted ORs of Val/Val were 1.3 (95% CI: 0.1-11.2) for gastric cancer and 0.9 (95% CI: 0.2-4.8) for chronic gastritis. Combining the Val alleles (Val/Val and Ile/Val) into one group, no association was observed between GSTP1 and both gastric cancer and chronic gastritis. In addition, the allelism at the GSTP1 locus did not increase gastric cancer and chronic gastritis risks associated with the GSTM1 or GSTT1 genotypes.

CONCLUSION

Our data suggest that the GSTP1 genotype seems not to be associated with the risk of gastric cancer and chronic gastritis in a high-risk Chinese population.

[Cellular compatibility of three natural xenogeneic bone derived biomaterials]

OBJECTIVE

To evaluate the cellular compatibility of three natural xenogeneic bone derived biomaterials.

METHODS

Three types of natural xenogeneic bone derived biomaterials were made with physical and chemical treatment, composite fully deproteinized bone(CFDB), partially deproteinized bone(PDPB) and partially decalcified bone(PDCB). Three types biomaterials were cocultured with human embryonic periosteal osteoblasts. The cell growth, attachment, cell cycle, alkaline phosphatase activity were detected to evaluate the cellular compatibility to biomaterials.

RESULTS

Osteoblasts attached on all three biomaterials and grew well, the effect of three biomaterials on cell proliferation was PDCB > PDPB > CFDB. The cell cycle was not obviously affected by three biomaterials. The effect of three biomaterials on alkaline phosphatase activity of osteoblasts was PDCB > PDPB > CFDB.

CONCLUSION

CFDB,PDPB,PDCB have good cellular compatibility without cytotoxic and tumorigenicity, CFDB is the best. The three biomaterials can be used as scaffold materials of bone tissue engineering.

Protective effect of green tea on the risks of chronic gastritis and stomach cancer

Despite the declining trend, stomach cancer remains the second most common cancer worldwide. We examined the role of green tea consumption on chronic gastritis and stomach cancer risks. A population-based case-control study was conducted in Yangzhong, China, with 133 stomach cancer cases, 166 chronic gastritis cases, and 433 healthy controls. Epidemiologic data were collected by standard questionnaire and odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression models in SAS. Inverse association was observed between green tea drinking and chronic gastritis and stomach cancer risks. After adjusting for age, gender, education, body mass index, pack-years of smoking and alcohol drinking, ORs of green tea drinking were 0.52 (95% CI: 0.29-0.94) and 0.49 (95% CI: 0.31-0.77) for stomach cancer and chronic gastritis, respectively. In addition, dose-response relationships were observed with years of green tea drinking in both diseases. The results provide further support on the protective effect of green tea against stomach cancer. This is the first time that green tea drinking was found to be protective against chronic gastritis, which may be of importance when designing intervention strategies for stomach cancer and its pre-malignant lesions in the high-risk population.

New ferrocenyl chiral auxiliary substituents for amines: applications to syntheses of mossambine and vinblastine

(+)-(R)-1,2-(alpha-(R)-Mesyloxy-beta-dimethyltetramethylene)-ferrocene was synthesized and used as a chiral auxiliary for N-alkylation of methyl 1,2,3,4,5,6-hexahydroazepino[4,5-b] indole-5-xi-carboxylates. Condensation with aldehydes then provided tetracyclic products in a diastereomeric ratio of at least 97:3. Gentle cleavage in acetic acid removed the chiral auxiliary to give the corresponding secondary amines in >99% ee. Thus, key intermediates leading to mossambine and vinblastine could be synthesized with high enantioselectivity. The enantioselectivity greatly exceeds that found with other chiral N-auxiliaries developed in our studies.

Structural insights into the mode of action of a pure antiestrogen

BACKGROUND

Estrogens exert their effects on target tissues by binding to a nuclear transcription factor termed the estrogen receptor (ER). Previous structural studies have demonstrated that each class of ER ligand (agonist, partial agonist, and SERM antagonist) induces distinctive orientations in the receptor's carboxy-terminal transactivation helix. The conformation of this portion of the receptor determines whether ER can recruit and interact with the components of the transcriptional machinery, thereby facilitating target gene expression.

RESULTS

We have determined the structure of rat ERbeta ligand binding domain (LBD) in complex with the pure antiestrogen ICI 164,384 at 2.3 A resolution. The binding of this compound to the receptor completely abolishes the association between the transactivation helix (H12) and the rest of the LBD. The structure reveals that the terminal portion of ICI's bulky side chain substituent protrudes from the hormone binding pocket, binds along the coactivator recruitment site, and physically prevents H12 from adopting either its characteristic agonist or AF2 antagonist orientation.

CONCLUSIONS

The binding mode adopted by the pure antiestrogen is similar to that seen for other ER antagonists. However, the size and resultant positioning of the ligand's side chain substituent produces a receptor conformation that is distinct from that adopted in the presence of other classes of ER ligands. The novel observation that binding of ICI results in the complete destabilization of H12 provides some indications as to a possible mechanism for pure receptor antagonism.

[Investigation of genotyping HLA DRB1 gene using oligoneucleotide arrays]

We have developed a method performed on an oligoneucleotide array for genotyping HLA DRB1. The routine method Phenol-chloroform was used to extract genome DNA of standard samples. A pair of sense and antisense primers were designed according to the sequence of DRB1 exon2, then the primers and the Cy5-dCTP were used in the following PCR, thus the PCR products were labelled with Cy5. Many genotyping probes which were immobilized on the DNA Microarray made by APS-PDC method were designed. The labelled PCR products were hybridized with them, the signals were sanned by sanner and analyzed by Imagene software. We have genotyped 33 standard samples which have 12 DRB1 subtypes. The experimental results showed that the arrays we made and the method we used are accurate and sensitive. This proved that the DNA Microarray technique is good for DRB1 genotyping. Compared with PCR-SSP and PCR-SSO methods, the genotyping chip method is more intuitionistic and has the advantage of integration.

Inhibitory effect of recombinant TGFalpha-PE40 on neointimal proliferation after arterial balloon injury

AIM

To investigate inhibitory effects of recombinant transforming growth factor alpha-Pseudomonas exotoxin 40 fusion protein (TGFalpha-PE40; TP40) on neointimal proliferation after arterial balloon injury.

METHODS

Forty male rabbits fed a cholesterol rich diet were randomly divided into TP40 15 microg, 30 microg, 60 microg, physiologic saline control, and normal artery groups (n=8). Rabbits in the treatment groups were treated by local administration of TP40 (15 microg, 30 microg, and 60 microg per rabbit) 24 h postinjury, and those in the control group were treated by physiologic saline 24 h postinjury. Remained 8 rabbits in normal artery group were treated by TP40 (60 microg). Optical microscope, electron microscope, and computer image analysis were used to study arterial segments 2 weeks after treatment.

RESULTS

Irregular thickening of the arterial intima, large amounts of smooth muscle cells (SMC) within the neointima, and stenosis of the arterial cavity were observed in the physiologic saline control group. Great inhibition of intimal proliferation and prevention of stenosis of the arterial cavity were observed in the TP40 treated groups that were examined 2 weeks postinjury by optical microscope. The uninjured carotids were histologically normal. Lots of destructural and necrotic SMC were observed in media in TP40 60 microg group by electron microscope. Computer image analysis showed that the neointimal area of the TP40-treated groups was markedly smaller than that of the saline control group (P < 0.01).

CONCLUSION

Recombinant TP40 greatly inhibited neointimal proliferation after arterial balloon injury.

IgG anti-melanocyte antibodies purified from patients with active vitiligo induce HLA-DR and intercellular adhesion molecule-1 expression and an increase in interleukin-8 release by melanocytes

An immunologic hypothesis is currently proposed as a possible pathogenesis of nonsegmental-type vitiligo. IgG antibodies against melanocyte surface antigens exist in the serum of patients with vitiligo vulgaris. IgG anti-melanocyte antibodies were reported to induce melanocyte damage in vitro by a complement-mediated mechanism and antibody-dependent cellular cytotoxicity. Perilesional melanocytes express major histocompatibility complex class II antigens and a higher intercellular adhesion molecule-1 compared with those in normal skin. The purpose of this study was to determine the role of IgG anti-melanocyte antibodies in the inappropriate expression of major histocompatibility complex class II antigens and intercellular adhesion molecule-1 on melanocytes. IgG anti-melanocyte antibody samples were purified from the individual serum of patients with active vitiligo. After incubation of IgG anti-melanocyte antibodies with cultured melanocytes, the results revealed: (i) IgG anti-melanocyte antibody stimulated HLA-DR expression on melanocytes; (ii) intercellular adhesion molecule-1 expression on melanocytes was significantly induced by IgG anti-melanocyte antibodies; and (iii) IgG anti-melanocyte antibodies induced an increase in interleukin-8 release from melanocytes. The major histocompatibility complex class II molecules expressed in melanocytes can present antigens to CD4 helper cells as antigen-presenting cells and elicit an immune response. Intercellular adhesion molecule-1 is an important adhesion molecule involved in leukocyte and parenchymal cell interaction and thus plays an essential part in immunologic and inflammatory reactions. It is reasonable to speculate that abnormal expressions of HLA-DR and intercellular adhesion molecule-1 on melanocytes by IgG anti-melanocyte antibodies would present vitiligo antigens and allow the antigen-specific immune effector cell attack that results in melanocytotoxicity.

Biogenetic syntheses of kopsijasminilam and deoxykopsijasminilam

The hexacyclic ketoester 7, derived from cyclization of racemic minovincine (6), was reduced to two C-19 epimeric alcohols 8 and 9. Stereoelectronically controlled fragmentations of corresponding O-sulfonyl derivatives provided, respectively, the hexacyclic enamine 14 and, after oxidation of the olefin 16, the pentacyclic lactam 17 with a brigehead double bond. Formation of a carbamate, introduction of a second double bond at C-16, and conjugate reductive hydroxylation at C-20, or hydrogenation, gave the title products.

Compensatory projection of primary nociceptors and c-fos induction in the spinal dorsal horn following neonatal sciatic nerve lesion

The sciatic nerve was cut in newborn rats, and prevented from regenerating for 8 weeks. The number of dorsal root ganglion (DRG) neurons in L4 and L5, the distribution of central axon terminals of primary nociceptors, and the activity of secondary nociceptors were examined in the lumbar dorsal horn. The neonatal sciatic lesion caused about 60% reduction of DRG neurons. The central terminal field of the sciatic primary nociceptors negatively labeled by in situ binding of Bandeiraea simplicifolia isolectin B4 (BsIB4) markedly shriveled. Instead, the central representation of the saphenous nerve and the posterior cutaneous nerve of the thigh (PC) expanded. The laminae I/II neuropil in the medialmost (1/4) of the L3 dorsal horn and in the second lateral (1/4) around the L4/5 junction was occupied by the BsIB4 binding sites derived from the saphenous and the PC primary neurons, respectively. Noxious stimuli applied to the receptive fields of the saphenous and the PC nerves induced c-Fos-like immunoreactivity in many neurons in the expanded central terminal fields of the nerves. The collateral sprouts of uninjured primary nociceptors did not only invade the deafferented area of the dorsal horn but also established functional synaptic connections.

Effects of antisense IRAK-2 oligonucleotides on PGI2 release induced by IL-1 and TNF

AIM

To explore the effects of antisense interleukin-1 receptor associated kinase-2 oligonucleotide (IRAK-2 ODN) on the prostacyclin (PGI2) synthesis in human umbilical vein endothelial cells (HUVEC) induced by interleukin-1 (IL-1) and tumor necrosis factor (TNF).

METHODS

The HUVEC were transfected with antisense IRAK-2 ODN and stimulated with IL-1 and TNF. The levels of PGI2 release were analyzed by competitive ELISA.

RESULTS

Pre-transfection with antisense IRAK-2 ODN could remarkably decrease the levels of PGI2 synthesis induced by IL-1 in a time- and concentration-dependent manner, whereas it could not attenuate the one stimulated by TNF.

CONCLUSION

The responses of antisense IRAK-2 ODN to IL-1 and TNF-stimulated PGI2 release are different. IRAK-2 plays a key role in the IL-1 signaling events leading to PGI2 release.