Analysis of HLA-A, HLA-B and HLA-DRB1 alleles in Chinese patients with lung cancer

The primary function of the human leukocyte antigen (HLA) system is to regulate the immune response. Because of its important role in the immune response and its high degree of polymorphism, the HLA system is associated with many diseases. We examined the polymorphisms of HLA-A, B and DRB1 alleles in 100 unrelated patients with lung carcinoma and in 438 unrelated normal controls of Han nationality from North China, using sequence-based typing and PCR with sequence-specific primers. We found that the frequencies of HLA-A*0201, A*2601, B*1518, B*3802, DRB1*0401, DRB1*0402, and DRB1*1201 were higher in the lung carcinoma group than in the normal control group. The P values were 0.035, 0.040, 0.001, 0.017, 0.014, 0.004, and 0.019, respectively, and the odds ratio values were 1.052, 3.513, 4.047, 3.054, 4.237, 19.397, and 2.128, respectively. The frequency of HLA-DRB1*1302 was lower in the lung carcinoma group than in the normal control group (P = 0.046, odds ratio = 0.168). We concluded that patients with lung cancer and healthy controls of Han nationality from North China differ in the frequencies of various HLA alleles.

Lifespan influences on mid- to late-life cognitive function in a Chinese birth cohort

OBJECTIVE

To explore factors throughout the lifespan that influence cognition in midlife to late life.

METHODS

We conducted a retrospective birth cohort study of 2,062 individuals born during 1921-1954 in Beijing, China. In 2003-2005, birth records were abstracted, and participants then 50-82 years old received standardized examinations for health, cognition, and socio-environmental measures. Using cumulative logit models, we assessed adjusted relative effects of prenatal, early life, and adult factors on mid- to late-life cognition.

RESULTS

Most prenatal factors were associated with mid- to late-life cognition in the unadjusted models. However, when childhood and adult factors were sequentially added to the models, the impact of prenatal factors showed successive attenuation in effect size, and became insignificant. In contrast, early life factors remained significantly associated with mid- to late-life cognition even after full life-course adjustments. Specifically, those whose fathers had laborer vs professional occupations (odds ratio [OR](Laborer) 1.74; 95% confidence interval [CI]: 1.25-2.42) had poorer cognitive outcomes, while individuals who drank milk daily in childhood (OR 0.65; 95% CI: 0.54-0.80), had more years of education (OR(10-12 years) 0.60; 95% CI: 0.45-0.81; OR(13+ yrs) 0.29; 95% CI: 0.23-0.38), and were taller adults (OR(height > or = SD) 0.65; 95% CI: 0.49-0.86) had better cognition. The high prenatal risk infants had similar patterns with a trend toward a stronger association between cognition and socioenvironmental factors.

CONCLUSION

Mid- to late-life cognition is influenced by factors over the entire lifespan with the greatest impact coming from early life exposures. Nutrition, education, social, and family environment in early life may have a long-term impact on cognition in developing countries.

Star-shaped cationic polymers by atom transfer radical polymerization from beta-cyclodextrin cores for nonviral gene delivery

Cationic polymers with low cytotoxicity and high transfection efficiency have attracted considerable attention as nonviral carriers for gene delivery. Herein, well-defined and star-shaped CDPD consisting of beta-CD cores and P(DMAEMA) arms, and CDPDPE consisting of CDPD and P(PEGEEMA) end blocks (where CD = cyclodextrin, P(DMAEMA) = poly(2-(dimethylamino)ethyl methacrylate), P(PEGEEMA) = poly(poly(ethylene glycol)ethyl ether methacrylate)) for gene delivery were prepared via atom transfer radical polymerization (ATRP) from the bromoisobutyryl-terminated beta-CD core. The CDPD and CDPDPE exhibit good ability to condense plasmid DNA (pDNA) into 100-200 nm size nanoparticles with positive zeta potentials of 25-40 mV at nitrogen/phosphate (N/P) ratios of 10 or higher. CDPD and CDPDPE exhibit much lower cytotoxicity and higher gene transfection efficiency than high molecular weight P(DMAEMA) homopolymers. A comparison of the transfection efficiencies between CDPD and P(DMAEMA) homopolymer indicates that the unique star-shaped architecture involving the CD core can enhance the gene transfection efficiency. In addition to reducing cytotoxicity, the introduction of a biocompatible P(PEGEEMA) end block to the P(DMAEMA) arms in CDPDPE can further enhance the gene transfection efficiency.

Anomalous line shape of the cross section for e{+}e{-}--> hadrons in the center-of-mass energy region between 3.650 and 3.872 GeV

We observe an obvious anomalous line shape of the e;{+}e;{-}--> hadrons total cross sections in the energy region between 3.700 and 3.872 GeV. It is inconsistent with the explanation for only one simple psi(3770) resonance with a statistical significance of 7sigma. The anomalous line shape may be explained by two possible enhancements of the inclusive hadron production near the center-of-mass energies of 3.764 and 3.779 GeV, indicating that either there is likely a new structure in addition to the psi(3770) resonance around 3.773 GeV, or there are some physics effects reflecting the DD[over ] production dynamics.

Laser-based gene transfection and gene therapy

The plasma membrane of mammalian cells can be transiently permeablized by optical means and exogenous materials or genes can be introduced into the cytoplasm of living cells. Until now, few mechanisms were exploited for the manipulation: laser is directly and tightly focused on the cells for optoinjection, laser-induced stress waves, photochemical internalization, and irradiation of selective cell targeting with light-absorbing particles. During the past few years, extensive progress and numerous breakthroughs have been made in this area of research. This review covers four different laser-assisted transfection techniques and their advantages and disadvantages. Universality towards various cell lines is possibly the main advantage of laser-assisted optoporation in comparison with presently existing methods of cell transfection.

Search for the invisible decay of J/psi in psi(2S) --> pi(+)pi(-) J/psi

Using psi(2S) --> pi(+)pi(-) J/psi events in a sample of 14.0 x 10(6) psi(2S) decays collected with the BES-II detector, a search for the decay of the J/psi to invisible final states is performed. No signal is found, and an upper limit at the 90% confidence level is determined to be 1.2 x 10(-2) for the ratio B(J/psi --> invisible)/B(J/psi-->mu(+)mu(-)). This is the first search for J/psi decays to invisible final states.

Observation of Y(2175) in J/psi --> etaphif0 (980)

The decays of J/psi --> etaphif(0)(980)[eta --> gammagamma, phi --> K(+) K(-), f(0)(980) --> pi(+)pi(-)] are analyzed using a sample of 5.8 x 10(7) J/psi events collected with the BESII detector at the Beijing Electron-Positron Collider. A structure at around 2.18 GeV/c(2) with about 5 sigma significance is observed in the phif(0)(980) invariant mass spectrum. A fit with a Breit-Wigner function gives the peak mass and width of m = 2.186+/-0.010(stat)+/-0.006(syst) GeV/c(2) and Gamma = 0.065+/-0.023(stat)+/-0.017(syst) GeV/c(2), respectively, which are consistent with those of Y(2175), observed by the BABAR Collaboration in the initial-state radiation process e(+)e(-) --> gamma(ISR) phif(0)(980). The production branching ratio is determined to be Br(J/psi --> etaY(2175))Br(Y(2175)- -> phif(0)(980))Br(f(0)(980) --> pi(+)pi(-)) = [3.23+/-0.75(stat)+/-0.73(syst)] x 10(-4), assuming that the Y(2175) is a 1(--) state.

Measurement of psi2S radiative decays

Using 14 x 10(6) psi(2S) events accumulated at the BESII detector, we report first measurements of branching fractions or upper limits for psi(2S) decays into gammapp, gamma2(pi+pi-), gammaKS0K+pi-+c.c., gammaK+K-pi+pi-, gammaK*0K-pi++c.c., gammaK*0K*0, gammapi+pi-pp, gamma2(K+K-), gamma3(pi+pi-), and gamma2(pi+pi-)K+K- with the invariant mass of hadrons below 2.9 GeV/c2. We also report branching fractions of psi(2S) decays into 2(pi+pi-)pi0, omegapi+pi-, omegaf2(1270), b1+/-pi-/+, and pi02(pi+pi-)K+K-.

High-resolution measurement of fiber length by using a mode-locked fiber laser configuration

A simple method to precisely measure fiber length has been experimentally demonstrated by using a mode-locked fiber laser configuration. Since the transit time in a cavity is exactly proportional to the cavity length, it is easy to obtain the fiber length from the generation of mode-locked pulses in the fiber laser with a long-range nonlinear optical loop mirror that includes the measured fiber. Our new method has a large measurement range, over hundreds of kilometers, and a high resolution, of the order of centimeters, as well as no measurement dead zone.

Location and phylogenetic analysis of the region immediately upstream of the granulin gene of the Clostera anachoreta granulovirus

The region immediately upstream of the granulin gene from Clostera anachoreta granulovirus (ClanGV) was identified from hybridization experiments and sequenced. The sequence of 5122nt EcoRI restriction fragment was presented and compared with the equivalent area in other GVs. Database searches showed that this region contained three open reading frames (ORFs) similar to the baculovirus genes (egt, fgf and me53, respectively) and four ORFs unique to ClanGV genome. Phylogenetic trees of the baculovirus genes egt and me53 were constructed. These analyses indicated that ClanGV genes may be more closely related to CfGV, CpGV, ClGV, PoGV and AoGV than to PxGV and XcGV.

Periodic ZnO nanorod arrays defined by polystyrene microsphere self-assembled monolayers

We demonstrate a low-cost and effective method to fabricate hexagonally patterned, vertically aligned ZnO nanorod arrays. Selective wet-etching is used to develop the catalyzing gold particle hexagonal pattern with the aid of a polystyrene microsphere self-assembled monolayer. The gold particles have tunable sizes independent of the polystyrene microsphere's diameter and are inherently round in shape. Each ZnO rod is grown individually from a catalyzing site via catalyst-initiated epitaxy, and the original hexagonal periodicity is well-preserved. The rods have flat ends, and the diameters of the rods can be controlled well by the amount of source materials. This method provides a promising way to create ZnO one-dimensional nanostructures for applications as two-dimensional photonic crystal, sensor arrays, nanolaser arrays, and optoelectronic devices.

Isotropic-nematic phase transition of nonaqueous suspensions of natural clay rods

A novel model system for studying the behavior of hard colloidal rods is presented, consisting of sterically stabilized particles of natural sepiolite clay. Electron microscopy and scattering results confirmed that the organophilic clay particles were individual, rigid rods when dispersed in organic solvents. With a length-to-diameter ratio of approximately 27, the particles showed nematic ordering for volume fractions phi > 0.06. Polarizing microscopy revealed that the phase separation process involved nucleation, growth, and coalescence of nematic domains. The phase volumes and particle concentrations in the coexisting phases were determined. The dependence of these quantities on the total concentration of the suspension agrees well with Onsager's [Ann. N. Y. Acad. Sci. 51, 627 (1949)] isotropic-nematic phase transition theory extended to bidisperse and polydisperse rod systems, and with previous experimental results for rigid rodlike particles. Particle size distributions were obtained by analyzing transmission electron microscopy images. A significant fractionation with respect to rod length (but not diameter) was observed in the coexisting isotropic and nematic phases. The relative polydispersity of both daughter phases was distinctly smaller than that of the parent suspension. The phase behavior of these daughter fractions agrees well with the predictions for hard spherocylinders of corresponding aspect ratios. An isotropic-nematic-nematic phase equilibrium was seen to develop in phase separated samples after 1 month standing and is ascribed to the effect of polydispersity and possibly gravity. The second nematic phase appearing is dominated by very long rods.

Characterization and partial genome sequence analysis of Clostera anachoreta granulovirus

The morphological and biological properties as well as partial genomic sequencing of a granulovirus isolated from Clostera anachoreta (Lepidoptera: Notodontidae), C. anachoreta granulovirus (ClanGV), were carried out. The ovoidal occlusion bodies were 337 nm x 170 nm in size, and each granule contained one single rod-shape virion, with a mean size of 250 nm x 46 nm. Granulin had a molecular weight of approximately 30 kDa. ClanGV genome size was estimated as 104.34 kb based on the restriction fragments. The restriction pattern of the ClanGV genome was different from other GVs. A restriction fragment genomic library of ClanGV genome was constructed. The library consisted of nine SalI fragments, seven HindIII fragments and seven EcoRI fragments. One 4.8 kb fragment of the genome, digested by SalI, was sequenced and analyzed. This region was composed of eight unknown ORFs, two baculoviruses homologous gene (vp1054 and lef10) and partial sequence of lef-8. The unknown ORFs included three unique to ClanGV, the other five ORFs were related to baculoviruses. The ORFs, located within this restriction fragment, were compared to homologues in other GVs. The results indicated that ClanGV, CpGV, ClGV, AoGV and PoGV had similar arrangement and orientation of the homologous ORFs. Phylogenetic analysis of VP1054 proteins from 20 baculoviruses indicated that ClanGV was more closely related to CpGV, ClGV, AoGV and PoGV than to other baculoviruses.

Relevance of ventricular electrical dispersion to arrhythmogenesis in ischemic myocardium--a simulation study

A computer simulation method was used to study the possible role of electrical dispersion induced by regional ischemia in the mechanisms underlying cardiac arrhythmias. Ischemic cells were simulated by considering the three major component conditions of acute ischemia (elevated extracellular K+ concentration, acidosis and anoxia) at the level of ionic currents and ionic concentrations. An ischemic area was introduced into a homogeneous healthy tissue to create a localized inhomogeneity. The constructed models were solved using the operator splitting and adaptive time step methods. The numerical experiments showed that action potential durations (APDs) of ischemic cells did not change with beats of shorter or longer cycle length. The smaller percentage increase of slow component of the delayed rectifier K+ current, I(ks), and smaller outward Na+-Ca2+ exchange current were found to be the ionic mechanisms underlying the decreased rate dependence in ischemic cells. The results suggest that ischemia flattens the APD restitution curve; however, the dispersion of refractory period can be greatly increased by a premature beat in the constructed inhomogeneous sheet. This demonstrates that the dispersion of refractoriness rather than APD by a premature beat contributes to reentrant tachyarrhythmias in the locally ischemic tissue.

Preparation of sodium fluoride-loaded gelatin microspheres, characterization and cariostatic studies

Sodium fluoride-loaded gelatin microspheres (NaF-GMS) were prepared using double-phase emulsified condensation polymerization. The average diameter of microspheres was (11.33+/-5.56) microm. The drug content and encapsulation efficiency were 8.80% and 76.73%, respectively. The fluoride releasing profiles of NaF-GMS in physiological saline and artificial saliva (pH 4.5, pH 6.8) showed that NaF-GMS had a sustained-release property and fluoride release rate was increased in pH 4.5 artificial saliva. Experiments conducted in rabbits' oral cavity using NaF-GMS and NaF solution as control revealed NaF-GMS could maintain oral fluoride retention longer than NaF solution. Cariostatic abilities of NaF-GMS including demineralization prohibition in vitro, fluoride deposition in artificial dental plaque and the ability of targeting to cariogenic bacteria were investigated in artificial dental plaque. The results indicated NaF-GMS with lower fluoride concentrations could achieve equivalent cariostatic effect to the concentrated NaF solution, at the same time, could prolong fluoride retention in dental plaque. Microscopic observation showed that NaF-GMS carrying fusion protein of glucan-binding domain could adhere more bacteria than NaF-GMS and this might indicate the possibility of targeting to cariogenic bacteria when NaF-GMS were properly modified.

[Construction and characterization of normalized cDNA library of maize inbred Mo17 from multiple tissues and developmental stages]

Comprehensive complementary DNA (cDNA) library is a valuable resource for functional genomics. In this study, we set up a normalized cDNA library of Mo17 (MONL) by saturation hybridization with genomic DNA, which contained expressed genes of eight tissues and organs from inbred Mo17 of maize (Zea mays L.). In this library, the insert sizes range from 0.4 kb to 4 kb and the average size is 1.18 kb. 10.830 clones were spotted on nylon membrane to make a cDNA microarray. Randomly picked 300 clones from the cDNA library were sequenced. The cDNA microarry was hybridized with pooled tissue mRNA probes or housekeeping gene cDNA probes. The results showed the normalized cDNA library comprehensively includes tissue-specific genes in which 71% are unique ESTs (expressed sequence tags) based on the 300 sequences analyzed. Using BLAST program to compare the sequences against online nucleotide databases, 88% sequences were found in ZmDB or NCBI, and 12% sequences were not found in existing nucleotide databases. More than 73% sequences are of unknown function. The library could be extensively used in developing DNA markers, sequencing ESTs, mining new genes, identifying positional cloning and candidate gene, and developing microarrays in maize genomics research.

Phytochemical and antiinflammatory studies on Terminalia catappa

The antiinflammatory activity of Terminalia catappa leaves ethanolic extract was studied using 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema in acute and chronic models. A bioassay-oriented fractionation procedure showed that the activity concentrates in the chloroform fraction. Ursolic acid (1) and 2alpha,3beta,23-trihydroxyurs-12-en-28-oic acid (2), isolated from the chloroform fraction, exhibited strong antiinflammatory activities. The results suggest that the triterpenic acids 1 and 2 are responsible for the antiinflammatory activity of T. catappa leaves.

[Gene point mutation in the dihydrofolate reductase-thymidylate synthase gene of Plasmodium falciparum]

OBJECTIVE

To investigate the gene point mutation in the dihydrofolate reductase-thymidylate synthase(dhfr) gene of Plasmodium falciparum isolate from Yunnan Province strongly associated with pyrimethamine and cycloguanil resistance.

METHODS

Nested PCR and restriction endonuclease digestion were applied to detect the gene mutation using dried blood filter paper collected from the fields in Yunnan Province.

RESULTS

Different mutations were found in 4 amino acids at positions 16, 51, 108 and 164 of dhfr gene, particularly, Asn-108 and Ile-51, the mutation frequency being 94.1% and 90.1%, respectively. The frequency of the wild-type genotype (3D7-type) Ser-108 appeared lower (9.1%), while the frequency of the Ala-16 was high(61.8%); the mutation-type was very high, the ratio of HB3-type, 7G8-type/FCR3-type and Cambodian-type was 1:21:7.5.

CONCLUSION

The investigation first demonstrated that Plasmodium falciparum Yunnan isolate dihydrofolate reductase-thymidylate synthase gene (dhfr) at positions 16, 51, 108 and 164 exhibited different degrees of point mutation. The frequency of mutation of the 7D8-type involved in pyrimethamine resistance was higher, while that of the FCR3-type involved in cycloquanil resistance was lower.

[Investigation on genotype constitution of different Plasmodium vivax isolates and its geographical distribution in China]

OBJECTIVE

To investigate the population constitution and geographical distribution of Plasmodium vivax in China using molecular technique.

METHODS

Blood-spot filter paper samples with related epidemiological data were collected from vivax malaria patients living in malarious area of 10 provinces (autonomous region) in China. Semi-nested- or nested-allelic-specific PCR genotyping method was used to identify CSP genotypes, families and types of Plasmodium vivax of each isolate from these patients.

RESULTS

Of 384 field isolates of Plasmodium vivax, 258 temperate zone family strains were identified, including 14 allelic variant genotypes spreading among 10 sampling provinces; allelic variants sized less than 731 bp were only seen in 5 provinces in southern China; 79 tropical zone family strains including 5 genotypes were also distributed in 5 provinces of southern China south to 25 degrees N. lat; and 14 PV Type-2 strains including 2 genotypes were found in some areas of Hainan and Yunnan Provinces. In addition, 33 isolates from genotype-mixed infections were revealed.

CONCLUSION

At present, area north to 25 degrees N. lat. of the country is the sole area prevalent for Plasmodium vivax family strains of temperate zone; there is overlapping distribution of P. v. of temperate zone family and tropical zone family of this parasite in the southern China south to 25 degrees N. lat; where the most complex isolate constitution is in Yunnan and Hainan Provinces, and PV Type-2 strains have been found in some areas of the two provinces. Besides, there were 2 groups of genotype with distinct geographic distribution feature within the temperate zone family.

[Studies on identification of circumsporozoite protein genotyping of Plasmodium vivax]

OBJECTIVE

To develop a new method of genotyping circumsporozoite protein (CSP) gene for identification of field isolates of Plasmodium vivax.

METHODS

Improved Chelex-100 ion-exchange method was used to extract DNA from blood filter paper samples, nested PCR and allele-specific PCR techniques, agarose gel electrophoresis analysis and dot/southern blotting-probe hybridization were employed for amplification, resolution and identification of the diagnostic fragments.

RESULTS

Using the nest-allele-specific PCR assay reported here, small amounts of DNA extracted from a piece of blood filter paper sample were amplified which produced three different size ranges of diagnostic bands: 650-770 bp PV-species-specific band, 170-230 bp diagnostic band for temperate zone family and 588 bp band for PV type-2. The sizes and patterns of the bands produced by the reference strains were consistent with those of designed target sequences. Of 59 examined isolates from 6 provinces of China, 42 temperate zone family strains, 15 tropical zone family strains and two PV type-2 strains were identified.

CONCLUSION

1, Three genotype strains of P. vivax mentioned above could be identified by this method with only two rounds of PCR and without probe hybridization. 2, The preliminary results showed that PV type-1 including temperate zone family strains and tropical zone family strains as well as PV type-2 strains are present in China. In addition, another CSP genotype with both sequence characteristics of temperate zone and tropical zone family might also be present in China.

[Experimental observation on anaphylaxis induced by Echinococcus infection in Meriones unguiculatus]

OBJECTIVE

To observe the anaphylaxis induced by Echinococcus granulosus or E. multilocularis (E. g. and E. m.) infection in Meriones unguiculatus.

METHODS

56 and 48 gerbils were intraperitoneally inoculated with E. g. protoscoleces and E. m. tissue homogenate. After three months, the anaphylactic responses initiated by intraperitoneal challenge injection with E. g. cystic fluids or partially purified antigen or E. m. metacestode homogenate antigen were observed. IgE antibody and direct eosinophilic leukocyte count (DELC) were detected at pre-postchallenge.

RESULTS

The infection rates for E. g and E. m. in 56 and 48 gerbils were 89.3% and 97.9%, respectively. Among these groups, the lowest rate of anaphylaxis was 62.5%, the highest was 100%. The lowest rate of anaphylactic shock was 12.5%, and the highest 16.7%. After the gerbis were infected with E. g. and E. m., both IgE antibody and DELC increased gradually. At 60 min post challenge, IgE antibody level were significantly decreased, while DELC showed a sharp increase.

CONCLUSION

Anaphylaxis could be induced in gerbils by Echinococcus infection followed by a challenge injection. Different antigens lead to different and degrees among the anaphylactic responses in the gerbils, however, there were no significant differences between E. g. and E. m. infections in gerbils.

Characterization of ambient volatile organic compounds at a landfill site in Guangzhou, South China

Ambient air monitoring was conducted at Datianshan landfill, Guangzhou, South China in 1998 to investigate the seasonal and horizontal variations of trace volatile organic compounds (VOCs). Twelve sampling points over the Datianshan landfill were selected and samples were collected simultaneously using Carbontrap(TM) adsorption tubes. Thirty eight VOCs were detected in the winter, whereas 60 were detected in the summer. The VOC levels measured in summer were alkanes, 0.5-6.5 microg/m(3); aromatics, 2.3-1667 microg/m(3); chlorinated species, 0.2-31 microg/m(3); terpines, 0.1-34 microg/m(3); carbonyl species, 0.3-5.6 microg/m(3) and naphthalene and its derivatives, 0.4-27 microg/m(3). Compared to the summer samples the VOC levels in winter were much lower (mostly 1-2 orders of magnitude lower). The aromatics are dominant VOCs in landfill air both in winter and summer. High levels of alkylbenzene and terpines such as methyl-isopropylbenzene (max 1667 microg/m(3)) and limonene (max 162 microg/m(3)) cause undesirable odor. The similar correlation coefficients of BTEX in summer and winter suggest VOCs emissions were from landfill site sources. The variation of BTEX ratio at landfill site is different from that in the urban area of Guangzhou. It shows that the ambient VOCs at landfill site were different from the urban areas.

Congou tea drinking and oesophageal cancer in South China

The study from a large hospital-based case-control for 1248 cases with oesophageal cancer and the same number of controls in South China showed that Congou, a grade of Chinese black tea, may protect against cancers of the oesophagus and reduce the risk of a combination of alcohol drinking and smoking (especially smoking), regardless of temperature when drinking.

[Determination of volatile organic compounds in atmospheric environment]

It is well known that volatile organic compounds (VOCs) are the main photochemical pollutants and ozone precursors of the photochemical smog. Investigation of photochemical pollution in the ambient air must focus on VOCs, but the concentration of VOCs in ambient air is in a very low level (10(-9)-10(-12), volume fraction), so there are difficulties in the determination of VOCs. In this work, based on the TO14A and TO15 methods recommended by the Environmental Protection Agency of United States, an improved method for the determination of fifty-six VOCs, mainly O3 precursors, in atmospheric environment was developed. Operating conditions of VOCs preconcentrator, gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were optimized. Air sample was first frozen by liquid nitrogen, and then H2O and CO2 were eliminated in the VOCs preconcentrator. The preconcentrated VOCs sample was injected to GC and detected by MS or hydrogen flame ionization detector (FID). The C2-C10 hydrocarbons were separated effectively in capillary columns under the high concentration of CO2. The detection limits were 0.1 microgram.m-3 and the relative standard deviations were in the range from 2.57% to 9.82%. This method has been used for the determination of VOCs in real samples. The results were satisfactory.

[An association analysis of apolipoprotein E genotypes with Alzheimer's disease in Chinese population]

OBJECTIVE

To analyse the association of apolipoprotein E genotypes with Alzheimer's disease in Chinese population.

METHODS

Using PCR and restriction enzyme digestion, we have analyzed ApoE allele frequency of Alzheimer's disease (AD) patients and healthy controls.

RESULTS

Among the 56 cases of AD, the frequency of ApoE epsilon 2, ApoE epsilon 3, ApoE epsilon 4 are 3 (2.7%), 84 (75.0%), 25 (22.3%) respectively, while in the 67 controls they are 9 (6.7%), 115 (85.8%), 10 (7.5%) respectively. The frequencies of the two groups have significant difference (P < 0.01) and the frequency of ApoE epsilon 4 allele is higher in AD than that in the health controls and the statistical treatment suggest that there is significant difference (chi 2 = 10.99, P < 0.01, OR = 3.59, 95% CI = 1.54-8.41). The frequency of the ApoE epsilon 3 is lower in AD than that in the health controls and the difference is also statistically significant(P < 0.05).

CONCLUSIONS

Our results are consistent with previous work in that proving the ApoE epsilon 4 allele is one of the risk factors of AD. The results also provide a support for the protection effect of ApoE epsilon 3 allele in developing AD.

[HPLC determination of oleanolic acid and llrolic acid in Chinese medicinal herbs]

OBJECTIVE

To develop a new method for simultaneous determination of oleanolic acid and llrolic acid in Chinese medicinal herbs at the same time.

METHOD

HPLC was carried out on a Shim-pack CLC-ODS column using MeOH-H2O-HOAc-TEA (83:17:0.04:0.02).

RESULT AND CONCLUSION

The average recovery of oleanolic acid and llrolic acid was 103.3 +/- 2.07% and 102.7% +/- 0.65% respectively.

CD3+CD4-CD8- alphabeta-TCR+ T cell as immune regulatory cell

Down-regulation of immune responses by regulatory T cells is one of the major mechanisms involved in the induction of tolerance to self- and alloantigens as demonstrated in a number of models of transplantation and autoimmunity. It is clear that regulatory T cells consist of different subsets. Recently a novel subset of antigen-specific alphabeta-TCR+ CD4-CD8- (double negative, DN) regulatory T cells has been found to be able to inhibit the function of the CD8+ T cells carrying the same T cell receptor specificity and prevent the rejection of skin allografts. Identification of the DN regulatory T cells and their novel mechanism of suppression can help us to understand how donor-specific transplantation tolerance can be achieved and to explain how tolerance to self-antigens can be maintained in the periphery.

Construction, safety, and immunogenicity in nonhuman primates of a chimeric yellow fever-dengue virus tetravalent vaccine

We previously reported construction of a chimeric yellow fever-dengue type 2 virus (YF/DEN2) and determined its safety and protective efficacy in rhesus monkeys (F. Guirakhoo et al., J. Virol. 74:5477-5485, 2000). In this paper, we describe construction of three additional YF/DEN chimeras using premembrane (prM) and envelope (E) genes of wild-type (WT) clinical isolates: DEN1 (strain PUO359, isolated in 1980 in Thailand), DEN3 (strain PaH881/88, isolated in 1988 in Thailand), and DEN4 (strain 1228, isolated in 1978 in Indonesia). These chimeric viruses (YF/DEN1, YF/DEN3, and YF/DEN4) replicated to ~7.5 log(10) PFU/ml in Vero cells, were not neurovirulent in 3- to 4-week-old ICR mice inoculated by the intracerebral route, and were immunogenic in monkeys. All rhesus monkeys inoculated subcutaneously with one dose of these chimeric viruses (as monovalent or tetravalent formulation) developed viremia with magnitudes similar to that of the YF 17D vaccine strain (YF-VAX) but significantly lower than those of their parent WT viruses. Eight of nine monkeys inoculated with monovalent YF/DEN1 -3, or -4 vaccine and six of six monkeys inoculated with tetravalent YF/DEN1-4 vaccine seroconverted after a single dose. When monkeys were boosted with a tetravalent YF/DEN1-4 dose 6 months later, four of nine monkeys in the monovalent YF/DEN groups developed low levels of viremia, whereas no viremia was detected in any animals previously inoculated with either YF/DEN1-4 vaccine or WT DEN virus. An anamnestic response was observed in all monkeys after the second dose. No statistically significant difference in levels of neutralizing antibodies was observed between YF virus-immune and nonimmune monkeys which received the tetravalent YF/DEN1-4 vaccine or between tetravalent YF/DEN1-4-immune and nonimmune monkeys which received the YF-VAX. However, preimmune monkeys developed either no detectable viremia or a level of viremia lower than that in nonimmune controls. This is the first recombinant tetravalent dengue vaccine successfully evaluated in nonhuman primates.

Optical rubbery ormosils sensor for the detection of ammonia

Rubbery ormosil films with immobilized aminofluorescein (AF) were investigated to develop an optochemical sensor for the determination of ammonia in water. The gel precursors with tetramethoxysilane (TMOS) and dimethyldimethoxysilane (DiMeDMOS) were deposited on glass supports, and characterized in terms of response to pH, and to dissolved ammonia at constant pH. After preconditioning the sensing film was stable for 6 months. The detection limit for ammonia in water was 0.2 microg mL(-1) (S/N 2), the response being linearly dependent on concentration in the range of 0.5 to 80 microg mL(-1) ammonia. The response time was less than 5 min. The effects of sodium chloride concentration, temperature, and coexisting metal ions and compounds were investigated.

[Study on the phase II metabolites of phenoprolamine hydrochloride in rat bile by LC/DAD/MSD]

AIM

To study the phase II metabolites of phenoprolamine hydrochloride (DDPH) in rat bile.

METHODS

DDPH was administered by i.p. to bile duct-cannulated rats. Bile samples were collected before drug administration and up to 12 h after drug administration. After being purified and enriched with C-18 SPE columns the rat bile samples were analyzed by LC/DAD/MSD to identify the peaks of phase II metabolites. The fractions of phase II metabolites were prepared by HPLC and treated with beta-glucuronidase, and then were purified and enriched with C-18 SPE columns and analyzed by LC/DAD/MSD. The corresponding reference standards of DDPH phase I metabolites were analyzed by LC/DAD/MSD under identical conditions.

RESULTS

The peaks M7, M8 and M9 in the chromatograms of rat bile samples were the phase II metabolites of DDPH and the enzymatic hydrolysates of M7, M8 and M9 were 1-(2, 6-dimethyl-4-hydroxyphenoxy)-2-(3, 4-methoxyphenylethylamino)-propane (M3), 1-(2, 6-dimethyl-3-hydroxyphenoxy)-2-(3, 4-methoxyphenylethylamino)-propane (M2) and 1-(2,6-dimethylphenoxy)-2-(3-methoxy-4-hydroxyphenylethyl-amino)-propane (M1) respectively.

CONCLUSION

beta-1-O-[3,5-dimethyl-4-[-2-methyl-2-(3,4-dimethoxy-phenylethylamino)- ethoxy]-phenyl]-glucuronic acid (M7, glucuronide of M3), beta-1-O-[2, 4-dimethyl-3-[2-methyl-2-(3, 4-dimethoxy-phenylethylamino)-ethoxy]-phenyl]-glucuronic acid (M8, glucuronide of M2) and beta-1-O-[2-methoxy-4-[1-methyl-2-(2, 6-dimethylphenoxy)-ethylamino-ethyl]-phenyl]-glucuronic acid (M9, glucuronide of M1) were the phase II metabolites of DDPH in rat bile.

[Glutamate causes release of nitric oxide from chicken spinal cord in vitro]

Nitric oxide (NO) has been identified to have profound effects on many systems, especially the neural tissues. Many studies suggest that NO mediate the neurotoxicity of glutamate (Glu). In order to determine in vitro whether Glu causes release of NO from chicken spinal cord, different concentrations of Glu (0.1, 0.5, 1.0 mmol.L-1) were added to the primary cultured chicken spinal cord cells, and the quantity of NO- (the metabolism product of NO) in medium was detected. The result shows that Glu can enhance obviously the concentration of NO in primary cell cultures (212% compared with the control). If the spinal cord cells were pretreated with NO synthases (NOS) inhibitor--L-NOARG, the [NO-] was decreased compared with those treated with Glu only, and, on the contrary, the viability of cells was increased. All of the results above indicate that NO may play an important role in the neurotoxicity of Glu on nervous cells. It might be that Glu can instigate the activity of NO synthases, then induce a series of changes within cell and finally lead to the toxic effect on cells.

[Effect of combination of ligustrazine and nitrendipine on hemodynamics in patients with chronic obstructive pulmonary disease]

OBJECTIVE

To find the drugs for lowering the pulmonary vascular resistance in patients of chronic obstructive pulmonary disease (COPD) but would not increase its side-effect.

METHODS

Changes of some hemodynamic parameters in 15 patients of COPD in stable stage treated by nitrendipine and ligustrazine were observed by right heart floating catheterization.

RESULTS

The mean pulmonary arterial pressure reduced by 1.4% immediately after the combined treatment, and reduced by 17.0%, 20.0% and 18.0% in 15 mins, 30 mins and 60 mins after treatment. In the responding time, the pulmonary vascular resistance reduced by 15.2%, 36.2%, 43.0% and 34.6%, the systemic vascular resistance reduced by 7.9%, 19.2%, 17.9% and 20.8%, and the cardiac output increased by 15.8%, 22.6%, 22.2%, and 33.8% respectively. The changes of systemic arterial pressure and heart rate were of no statistical significance.

CONCLUSION

Combination therapy of nitrendipine and ligustrazine could lower the pulmonary arterial pressure and pulmonary vascular resistance effectively and has a selective effect on pulmonary circulation in patients with COPD.

[Study on the phase I metabolites of phenoprolamine hydrochloride in rat bile by LC/DAD/MSD]

AIM

To study the phase I metabolites of phenoprolamine hydrochloride (DDPH) in rat bile.

METHODS

DDPH was administered i.p. to bile duct-cannulated rats. Bile samples were collected before administration and up to 12 h after administration. After being treated with beta-glucuronidase, the bile samples were purified and enriched with C-18 SPE columns, and then were analyzed by LC/DAD/MSD. The samples containing synthesized reference standards of DDPH metabolite 1-(2, 6-dimethylphenoxy)-2-(3-methoxy-4-hydroxyphenylethylamino)-propane (M1), 1-(2, 6-dimethyl-3-hydroxyphenoxy)-2-(3, 4-methoxy-phenylethylamino)-propane (M2), 1-(2,6-dimethyl-4-hydroxyphenoxy)-2-(3,4- methoxyphenylethylamino)-propane (M3), 1-(2, 6-dimethyl-3-hydroxyphenoxy)-2-(3-hydroxy-4- methoxyphenylethylamino)-propane (M4), 1-(2, 6-dimethyl-3-hydroxyphenoxy)-2- (3-hydroxy-4-methoxyphenylethylamino)-propane (M5) and 1-(2,6-dimethyl-4-hydroxyphenoxy)-2-(3-methoxy-4- hydroxyphenylethylamino)-propane (M6) were analyzed by LC/DAD/MSD under identical conditions.

RESULTS

The retention times, UV spectra, molecular weights and production spectra (obtained by collision-induced dissociation) of the apparent ions of peak A, B, C, D, E and F in the total ion chromatogram of DDPH treated rat bile sample were consistent with those of M1, M2, M3, M5, M4 and M6, respectively.

CONCLUSION

M1, M2, M3, M4, M5 and M6 were identified as the phase I metabolites of DDPH in the rat.

The effects of frequency of social interaction and relationship closeness on reward allocation

In this study of how the frequency of interaction affects decisions on reward allocation, 320 Chinese adults were randomly assigned to 8 conditions and instructed to read a scenario describing 2 co-workers completing a task and obtaining a bonus. The 8 conditions differed in the type of relationships, the frequency of past interaction between co-workers, and the possibility of future interaction. Each participant was instructed to act as the allocator and to hypothetically allocate a monetary reward to the co-worker. The results indicated that both past interaction and future interaction between the co-workers significantly influenced the allocation decision. These results also suggested that the frequency of 2 individuals' past interaction can be predictive of the closeness of their relationship.

[Analysis of the metabolite of 7-(4-chlorbenzyl)-7,8,13,13a-tetrahydroberberine in rabbit]

AIM

To explore the biotransformation of compound 7-(4-chlorbenzyl)-7,8,13, 13a-tetrahydroberberine in the rabbit.

METHODS

Analyze the rabbit bile sample with HPLC, LC/MS and LC/NMR.

RESULTS

A metabolite and unchanged 7-(4-chlorbenzyl)-7,8,13,13a-tetrahydroberberine were found in the rabit bile, the metabolite was characterized and its structure was elucidated.

CONCLUSION

Compound 7-(4-chlorbenzyl)-7,8,13,13a-tetrahydroberberine is metabolized by demethylation at 10-OCH3 position.

[Clinical characteristics of Parkinson's disease in natural population]

OBJECTIVE

To study the Clinical characteristics of Parkinson's disease(PD) in natural population.

METHODS

All the patients diagnosed as Parkinsonism from a prevalence study in Beijing in 1997 were collected for investigation. The spectrum of the clinical features of Parkinsonism and the onset, progression and prognosis of PD were analysed, as well as the impact factors to the prognosis were analysed.

RESULTS

109 cases were ascertained as PD from the sample population, in which 64(58.7%) were PD, 11 (10.1%) were Parkinson plus syndrome and 34(31.2%) were symptom Parkinsonism. 30 of the 64 PD cases were male. The median age of PD was 74.5 years. The median age at onset was 68 years old. The median duration was 5 years. The average Hoehn-Yahr staging score was 2.81. The clinical characteristics of PD and other Parkinsonism were compared, as asymmetry of symptoms and signs was an important feature to differentiate PD from other Parkinsonism. 20.3 percent of PD cases were associated with dementia. 16(25%) of the 64 PD cases initiated with essential tremor and developed to PD during 6-49 years after the onset of tremor. Tremor was the dominant initial symptoms of PD(60.9%). Type of initial symptoms was a relatively definite impact factor to the prognosis of PD. Levodopa treatment was likely to delay the duration of PD.

CONCLUSIONS

The clinical features of Parkinsonism in natural population were different as compared with previous studies. A further study on the natural history of PD thoroughly is needed.

Molecular basis for attenuation of neurovirulence of a yellow fever Virus/Japanese encephalitis virus chimera vaccine (ChimeriVax-JE)

A yellow fever virus (YFV)/Japanese encephalitis virus (JEV) chimera in which the structural proteins prM and E of YFV 17D are replaced with those of the JEV SA14-14-2 vaccine strain is under evaluation as a candidate vaccine against Japanese encephalitis. The chimera (YFV/JEV SA14-14-2, or ChimeriVax-JE) is less neurovirulent than is YFV 17D vaccine in mouse and nonhuman primate models (F. Guirakhoo et al., Virology 257:363-372, 1999; T. P. Monath et al., Vaccine 17:1869-1882, 1999). Attenuation depends on the presence of the JEV SA14-14-2 E protein, as shown by the high neurovirulence of an analogous YFV/JEV Nakayama chimera derived from the wild JEV Nakayama strain (T. J. Chambers, A. Nestorowicz, P. W. Mason, and C. M. Rice, J. Virol. 73:3095-3101, 1999). Ten amino acid differences exist between the E proteins of ChimeriVax-JE and the YFV/JEV Nakayama virus, four of which are predicted to be neurovirulence determinants based on various sequence comparisons. To identify residues that are involved in attenuation, a series of intratypic YFV/JEV chimeras containing either single or multiple amino acid substitutions were engineered and tested for mouse neurovirulence. Reversions in at least three distinct clusters were required to restore the neurovirulence typical of the YFV/JEV Nakayama virus. Different combinations of cluster-specific reversions could confer neurovirulence; however, residue 138 of the E protein (E(138)) exhibited a dominant effect. No single amino acid reversion produced a phenotype significantly different from that of the ChimeriVax-JE parent. Together with the known genetic stability of the virus during prolonged cell culture and mouse brain passage, these findings support the candidacy of this experimental vaccine as a novel live-attenuated viral vaccine against Japanese encephalitis.

[Therapeutic mechanism of combination therapy of ligustrazine and nitrendipine in treating patients with chronic obstructive pulmonary disease]

OBJECTIVE

To study the therapeutic mechanism of combination therapy of ligustrazine and nitrendipine in treating patients with chronic obstructive pulmonary disease (COPD).

METHODS

Thirty COPD patients divided in to 3 groups (10 in each) were treated with ligustrazine, nitrendipine and ligustrazine plus nitrendipine respectively, and the changes of hemorrheologic parameters, plasma endothelin (ET-1), thromboxane A2(TXA2) and platelet-P-selectin (CD62P) before and after treatment were observed.

RESULTS

The combination therapy of ligustrazine and nitrendipine could lower the levels of plasma ET-1, TXA2, CD62P and the hemorrheologic parameters.

CONCLUSION

Combination of ligustrazine and nitrendipine showed a therapeutic effect better than that of the two drugs used separately. Its effect in lowering pulmonary circulation resistance is related with the lowering of plasma vaso-contrictive factor and the changing of hemorrheologic properties. The integrated traditional Chinese and western medical therapy is valuable in treating COPD.

A study on the electrophysiological heterogeneity of rabbit ventricular myocytes the effect of ischemia on action potentials and potassium currents

With the whole-cell variant patch-clamp technique, action potentials (AP) and outward potassium currents of rabbit ventricular myocytes isolated from subendocardium and subepicardium were recorded and their changes were observed under normal and ischemia conditions. The results showed that (1) under normal condition, there were differences in the AP figures between ventricular subendocardial and subepicardial myocytes. Action potentials recorded from subepicardial myocytes had shorter action potential duration (APD) and a notch between phases 1 and 2, compared with those of subendocardial myocytes. The resting potential had no significant difference between these two populations of the action myocytes; (2) under ischemia condition, the notch of action potentials of subepicardial myocytes disappeared and the APD was shortened even more, compared with that of subendocardial myocytes; (3) under normal condition, the density of steady-state outward potassium currents of subepicardial myocytes was significantly greater than that of subendocardial myocytes; (4) under ischemia condition, the increase of steady-state outward potassium currents of subepicardial myocytes was greater than that of subendocardial myocytes. Glybenclamide could partly reverse the above changes. It is suggested that the increase of steady-state outward potassium currents during ischemia is mainly due to the opening of I(K-ATP) channels as a result of the deficiency of intracellular ATP caused by ischemia.

[Separation and determination of effective components in silymarin and preparations of silymarin by MECC]

AIM

To develop a micellar electrokinetic capillary chromatographic (MECC) method for the separation and determination of silybin, isosilybin, silydianin and silycristin in Legalon capsules, Yiganling tablets and silymarin.

METHODS

A buffer solution containing 30 mmol.L-1 disodium tetraborate, 50 mmol.L-1 taurodeoxycholic acid sodium salt and 20 mmol.L-1 beta-cyclodextrin (pH 9.2) was found to be the most suitable electrolyte for this separation. The applied voltage was 20 kV and UV detection wavelength was 288 nm. Rutin was used as internal standard.

RESULTS

The average recoveries of 99.9% for silycristin, 98.3% for silydianin, 99.0% for silybin and 98.2% for isosilybin were obtained.

CONCLUSION

The method is sensitive and accurate for the analysis of diasteroisomers of silybin and isosilybin.

[Determination of fatty acids in shark cartilage by GC-MS using microwave-assisted digestion and derivatization]

A rapid microwave-assisted digestion and derivatization method for the determination of fatty acids in shark cartilage by GC-MS was developed. The optimum conditions for digestion and derivatization were studied in detail using orthogonal design. The digestion and derivatization were accomplished in 4 minutes at 600 W microwave power using HCl-methanol (1:4, V/V) as digestion and derivatization solvent, and the extraction of the target analytes could be carried out simultaneously. This method is rapid, solvent-saving, and particularly suitable for the rapid determination of fatty acids in solid samples.

Identification of a previously unknown antigen-specific regulatory T cell and its mechanism of suppression

Despite increasing evidence for the existence of antigen-specific regulatory T cells, the mechanisms underlying suppression remain unclear. In this study we have identified and cloned a novel subset of antigen-specific regulatory T cells and demonstrated that these T cells possess a unique combination of cell surface markers and array of cytokines. The regulatory T cells are able to inhibit the function of T cells carrying the same T-cell receptor specificity and prevent skin allograft rejection in an antigen-specific, dose-dependent manner. The regulatory T cells are able to acquire alloantigen from antigen-presenting cells, present the alloantigen to activated syngeneic CD8+ T cells and then send death signals to CD8+ T cells. These findings provide a novel mechanism of regulatory T-cell-mediated, antigen-specific suppression.