Enhancement of humoral immune responses to HBsAg by heat shock protein gp96 and its N-terminal fragment in mice

AIM: Most studies on the immune effect of gp96 were focused on its enhancement of CTLs. It is interesting to know whether gp96 could influence the humoral immune response, and whether the recombinant N-terminal fragment of gp96 could substitute native gp96 to stimulate the immune system.METHODS: gp96 isolated from livers of normal mice and its N-terminal fragment (amino acid 22-355) expressed in E coli were used for immunization of BALb/c mice. Eight groups of mice received one of the following regiments subcutaneously in 100 μL phosphate buffered saline (PBS)at an interval of 3 wk. Group 1: PBS only; group 2:gp96 only; group 3: N-terminal fragment only; group 4: HBsAg only; group 5: HBsAg+gp96; group 6: HBsAg+N-terminalfragment; group 7: HBsAg+incomplete Freud's adjuvant; group 8: HBsAg+N-terminal fragment (95 ℃ heated for 30 min). Serum anti-HBsAg antibody levels were assayed by ELISA. CTL responses in splenocytes were analyzed by ELISPOT after the last vaccination.RESULTS: The average titer of serum anti-HBsAg antibodyin the mice immunized with HBsAg together with gp96 or its N-terminal fragment were much higher than those immunized with HBsAg alone detected by ELISA. The cellular immune response of the mice immunized with HBsAg together with gp96 or its N-terminal fragment was not different with those immunized with HBsAg alone measured by ELISPOT assay.CONCLUSION: gp96 or its N-terminal fragment greatly improved humoral immune response induced by HBsAg, but failed to enhance the CTL response, which demonstrated the potential of using gp96 or its N-terminal fragment as a possible adjuvant to augment humoral immune response against HBV infection.

Evaluation on Sensitivity of the Human Sperm Motility Assay for Detecting Endotoxin in Culture Medium

Objective To investigate the sensitivity of the human sperm motility assay for detecting endotoxin in culture mediumMaterials &. Methods Motile sperm were separated and exposed to different concentrations of endotoxin (0.5 ng/mL, 1ng/mL, 10ng/mL, 1000ng/mL, 10 000ng/ mL, and 50 000ng/mL), and sperm motility was determined after incubation. Effects of endotoxin on sperm motility in media without albumin were also examined. In addition, at the same concentrations of endotoxin (0. 5ng/mL, 1 ng/mL, and 10 ng/ mL ) , the sensitivity of the human sperm motility assay was compared to those of 1-cell and 2-cell mouse embryo bioassays.Results At levels of 0. 5ng/mL-1000ng/mL endotoxin in media with 2mg/mL albumin, sperm did not show significant change in motility during 24 h of incubation when compared with the control (P>0. 05). However, the sperm motility was significantly inhibited at endotoxin dosages of 10 000 and 50 000 ng/mL. In the absence of albumin supplementation, at endotoxin levels of 50 000ng/mL, and 1 000ng/mL, there was a marked decrease in sperm motility compared with the control after 2 h or 8 h of incubation, respectively (P<0. 01). In media containing 0. 5 ng/mL and 1 ng/ mL endotoxin, 1-cell and 2-cell mouse embryos had significantly reduced developmental rates in all developmental stages, and at the level of 10ng/mL, the development of the embryos was arrested. Conclusion The human sperm motility assay could detect high levels of endotoxin in culture medium but its sensitivity to endotoxin would be inferior to that of the 1-cell or 2-cell mouse embryo bioassay. In the absence of albumin supplementation, the sensitivity of the sperm motility assay could be improved.

Morphology, Growth Process and Symmetry of {0001} Face on Yb:YAl_3(BO_3)_4 Crystal

The {0001} face develops on the habit of self-frequency doubling laser crystal Yb: YAI3(B03)4 (YbYAB) only under high growth rate condition, and its morphology is rough. To study the growth mechanism of {0001} face, we have observed the growth morphology on {0001} polishing section by atomic force microscopy (AFM). A series of AFM images captured in different growth durations on the {0001} polishing section reflect the crystal growth process. It is shown that the growth morphology on the {0001} polishing section was rough with many hillocks at the first growth stage, and it can become smooth finally, although the growth morphology on the {0001} face developed naturally on YbYAB crystal habit is always rough. On the smooth {0001} surface formed at the last growth stage, there are some triangular pits. This fact is different from that of hillocks in most crystal growth morphologies. AFM can easily distinguish the pits or hillocks on the surface, but differential interfere contrast microscopy (DIC) can not do. The orientation of the triangular pits is just the opposite to the triangular {0001} faces. The chemical etching pattern is also composed of this kind of triangular pits. These growth morphology and etching pattern of the {0001} faces show 3m symmetry, but the point group of YbYAB crystal is 32. The symmetric contradiction between morphology and point group does not exist for quartz, although which has the same point group as YbYAB. From quartz {0001} surface morphology we can distinguish the right form or left form of the crystal, but from YbYAB {0001} surface morphology we can not do. The reason for the symmetric contradiction between YbYAB {0001} surface morphology and its point group is not known yet.

Effect of Clenbuterol Hydrochloride on the in vitro Development of Mouse Embryo

To investigate the effect of clenbuterol hydrochloride on the in vitro development of both 1 cell and 2 cell mouse embryos. Methods The cultural systems of both 1 cell and 2 cell mouse embryo were used to determine the effect of clenbuterol hydrochloride at doses of 1 ng/mL, 3 ng/mL, and 10 ng/mL on developmental rates of mouse embryos. Results When 1 cell embryos cultured with 1 ng/mL of clenbuterol hydrochloride, developmental rates from the 4 cell stage to blastocyst stage were significantly lower than those in the control group (P<0.05), but on dosages of 3 ng/mL and 10 ng/mL, the inhibiting effects on embryo development were significantly increased (P<0.01). When 2 cell embryos cultured with 1 ng/mL of clenbuterol hydrochloride, obvious differences in developmental rates were not found between the 2 cell embryo group and the control (P>0.05). However, at levels of 3 ng/mL and 10 ng/mL, significant decrease of developmental rates in 2 cell embryos was observed from the 4 cell and from the 8 cell stage, respectively (P<0.05). Embryos cultured with clenbuterol hydrochloride appeared to have more granules, fragments and degeneration than those in the control. Conclusion Clenbuterol hydrochloride has a toxic effect on the mouse embryos, and the effect is in a dose dependent. 1 cell mouse embryos cultured with clenbuterol hydrochloride could be easily inhibited at 2 cell stage, but the effect of clenbuterol hydrochloride on development of the late 2 cell embryos would be reduced.

Sensitivity of sperm motility assay for detecting endotoxin effect on human sperm in vitro

Objective: To evaluate the sensitivity of sperm motility assay for detecting the endotoxin effect on human sperm in vitro. Methods: Motile human sperm were separately incubated for up to 24 hours with different concentrations of endotoxin (0.5, 1, 10, 1000, 10 000 and 50 000 ng/mL). Then the sperm motility was determined. The effect of endotoxin on the sperm motility in media without albumin was also determined. In addition, at the endotoxin concentrations of 0.5, 1 and 10 ng/mL, the sensitivity of the assay was compared to those of 1-cell and 2-cell mouse embryo bioassays. Results: At levels of 0.5-1 000 ng/mL endotoxin in media with 2 mg/mL albumin, sperm did not show significant change in motility after 24 h of incubation (P>0.05), while it was significantly inhibited at endotoxin levels of 10 000 and 50 000 ng/mL. In media without albumin, endotoxin levels of 50 000 and 1 000 ng/mL, markedly inhibited the sperm motility after 2 or 8 h of incubation (P<0.01). With media containing 0.5 and 1 ng/mL endotoxin, there was a significant reduction in the development rate at all developmental stages with 1-cell and 2-cell mouse embryo assays and at the level of 10 ng/mL, the embryo development was completely arrested. Conclusion: The sperm motility assay could detect high levels of endotoxin effect in vitro, but its sensitivity is low as compared with the 1-cell or 2-cell mouse embryo bioassay.

Reaction of 1,1-Di-p-methoxyphenyl-2,2-dinitroethylene and 1,1-Di-O-methoxyphenyl-2,2-dinitroethylene with 1-Benzyl-1,4-dihydroni-cotinamide:Evidence for Concerted Electron-hydrogen Atom Trans-fer Mechanism

Di-p-methoxyphenyl-2, 2-dinitroethylene reacts with 1-benzyl-1, 4-dihydronico- tinamide (BNAH) in deaerated acetonitrile to give 1, 1-di-p-methoxyphenyl-2, 2-dinitroethane, while 1, 1-di-O-methoxyphenyl-2, 2-dinitroethylene fails to react with BNAH under the same conditions, which provides evidence for a concerted electron-hydrogen atom transfer mechanism.

Synthesis and Reaction of [MnRe(CO)_6(μ-SH)(μ-SC(H)PPr_3~i)(PPh_3)]

The synthesis, the crystal structure and the reaction of the hetero-binuclear complex [MnRe(CO)6(-SH)(-SC(H)PPri3)(PPh3)] are reported. The results of single crystal X-ray structure analysis showed that the fragments Mn(CO)3 and Re(CO)3 were bridged by SH and SC(H)PPri3. The title complexes can react with BunLi and RX forming complexes MnRe(CO)6(-SR)(-SC(H)PPri3)(PPh3) (R = Me, CH2CH=CH2, SnBu3n).

Metallurgical quality of CSP thin slabs

The casting structure, chemical composition segregation, dendrite arm space,inclusiona and during the CSP (compact strip production) rolling process were investigated. Theresults show that the CSP thin slab has a feature of uniform fine grains, more columnar crystals,less central porosity and segregation etc. There is no great difference in macrostructure betweenthe CSP thin slab and conventional slab; however, the fine dendrite structure of the CSP slab ismore uniform. Moreover, the central porosity and segregation are obviously improved after the firstpass; and the dendrite is bent along the rolling direction rather than broken into pieces. Smallinclusions with the diameter less than 10 mum in the CSP slab are dominantly consisted of aluminatesformed by Al deoxidation and Ca treatment and not floating out of the melt. The large sizeinclusions found in the continuous casting slab are very few.

Growht and defects in YbxY1—xAl3（BO3）4 crystals

YbxY1-xAl3(BO3)4(x=0.1,0.07 and 0)crystals have been grown by the flux method.The growth defects of YbxY1-xAl3(BO3)4 crystals were detected by X-ray topography.It is found that the perfcetion of YbYAB crystal with low Yb dopant is better than that with high Yb dopant.In Yb0.1Y0.9Al3(BO3)4 crystal,growht bands,growth boundaries,grown-in dislocations and inclusions were observed.Howver,the densities of growth defects for Yb0.07Y0.93Al3(BO3)4 and YAl3(BO3)4 are low and no obvious inclusions are observed in these crytals.In addition,growth twins wrer detected in YbxY1-xAl3(BO3)4 crystal by using the chemical etching method.It is found that the growth twins occur frequently in Yb0.01Y0.9Al3(BO3)4 crystal whereas no growth twin appears in YAl3(BO3)4 crystal. Based on the experimental observations,the formation mechanism of growth twins is discussed.In the meantime,the effective measures for reducing the growth twins and defects are proposed.2001 Elsevier Science B.V.All rights reserved.

Evaluation of a Rat Model of Experimental Autoimmune Encephalomyelitis with Human MBP as Antigen

Experimental autoimmune encephalomyelitis(EAE) is a good model for human multiple sclerosis(MS) research.However,there are some defects in the traditional models.Here,we improved the model by using the human myelin basic protein(MBP) as antigen.EAE was induced by immunization of female Wistar rats with human MBP.Compared with the traditional models,the new model was evaluated by clinical signs to pathological changes.The immune state of the model was assessed by the lymphocyte infiltrative response and levels of TNF-α,IFN-γ,IL-10.It was found that most of rats exhibited tail tone loss and hind-limb paralysis, also there were demyelination,infiltrative lymphocyte foci,“neuronophagia”in the cortex of cerebra and the white matter of spinal cords.PBMCs and spleen lymphocytes were strongly responsive to the stimulation of MBP and PHA.The levels of TNF-α and IFN-γ were altered with the severity of EAE.In the remitting phase, IL-10 was increased significantly.This study demonstrates that the animal model of EAE induced by human MBP bears resemblance to the features of human multiple sclerosis and promises to be a better model than ever before for the study of MS.Cellular & Molecular Immunology.2004;1(5):387-391.

The Haplotyping Problem：An Overview of Computational Models and Solutions

The investigation of genetic differences among humans has given evidence thatmutations in DNA sequences are responsible for some genetic diseases. The most common mutation isthe one that involves only a single nucleotide of the DNA sequence, which is called a singlenucleotide polymorphism (SNP). As a consequence, computing a complete map of all SNPs occurring inthe human populations is one of the primary goals of recent studies in human genomics. Theconstruction of such a map requires to determine the DNA sequences that from all chromosomes. Indiploid organisms like humans, each chromosome consists of two sequences called haplotypes.Distinguishing the information contained in both haplotypes when analyzing chromosome sequencesposes several new computational issues which collectively form a new emerging topic of ComputationalBiology known as Haplotyping. This paper is a comprehensive study of some new combinatorialapproaches proposed in this research area and it mainly focuses on the formulations and algorithmicsolutions of some basic biological problems. Three statistical approaches are briefly discussed atthe end of the paper.

The Technical Framework of Multi-source Remote Sensing Data Mining

With the delivery of a great deal remote sensing data to land from Landsat constantly, Remote Sensing Satellite Ground Station accumulates abundant satellite remote sensing data. For lack of effective data mining (DM) and knowledge Discovery from Databases (KDD technique) to these data, most part of the information cannot be usede fficiently. Technical innovation and improvement of the traditional DM and KDD, study of the data mining and KDD will both increase the interpretation level and intelligentized, and moreover explore and utilize the remote sensing information at the maximum degree. Based on the traditional data mining and KDD, the authors probed the technical flow of DM and KDD of the remote sensing, designed the systematical framework of multi-sources remote sensing DM, put forward a prototypeEstablished a base for further exploring andsystem.of multi-sources remote sensing DM system. developing multi-sources remote sensing DM system.