[Study of altered expression of annexin IV and human endometrial receptivity]

OBJECTIVE

To explore the association of altered expression of annexin IV in human endometrium during the implantation window and endometrial receptivity.

METHODS

A comparative proteomic strategy, in a combination of two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), was adopted to search for proteome alternations of pre-receptive (day LH + 2) versus receptive (LH + 7) endometria. The location and abundance of the identified differentially expressed protein- annexin IV were analyzed by immunostaining and western blot.

RESULTS

By comparing protein profiles of LH + 2 and LH + 7 samples, we found a protein up-regulated 2.12 times in LH + 7 samples, with a relative molecular weight of 36,000 and an isoelectric point near pH 5.8. It was characterized using mass spectrometry and was identified as annexin IV. Immunohistochemical analysis revealed an altered localization of annexin IV--in the epithelia on day LH + 2, and both in the epithelia and stroma cells on day LH + 7. Protein levels of annexin IV were up-regulated on day LH + 7 compared with that on day LH + 2 by Western blot. Integrated optical density of the object (OPTDI) was 46.249 +/- 32.376 and 249.507 +/- 31.959, respectively (P = 0.004).

CONCLUSIONS

Our study indicates endometrial samples obtained by microbiopsy are available for proteomics studies. It seems possible that the increased expression of annexin IV during the implantation window plays an important role in the morphological differentiation of the uterus to the receptive state.

[A clinical study of immediate dental implant and immediate restoration]

OBJECTIVE

To evaluate the clinical results of immediate implant and immediate restoration and to discuss the applying principles of these techniques.

METHODS

Fourteen cases underwent immediate implant surgery for 37 dental implants immediately after the teeth or roots were extracted. Among them, 6 cases (14 implants) received immediate restoration after implant placement. The second stage operation and final restoration were performed 4 months on average postoperatively, and the mean follow-up time was 22 months.

RESULTS

Two implants from 1 case were lost at 3 weeks after immediate implant and immediate restoration. The rest cases achieved good clinical results. Accumulative 4-year survival rate was 94.6%.

CONCLUSIONS

The result of immediate implant and immediate restoration is predictable if the cases are properly selected.

The miscarriage-associated HLA-G -725G allele influences transcription rates in JEG-3 cells

BACKGROUND

HLA-G is a non-classical HLA with important immunomodulatory roles in pregnancy. A polymorphism in the promoter region, -725G, was previously associated with sporadic miscarriage in women who were unselected with respect to reproductive history. In this study, the transcription levels of different HLA-G promoter haplotypes were examined to determine whether the miscarriage-associated -725G allele influences transcription.

METHODS

Five naturally occurring promoter haplotypes and three variant haplotypes created by site-directed mutagenesis were sub-cloned into luciferase expression vectors and transfected into JEG-3 cells. Expression levels of these eight haplotypes were examined in cultured cells before and after treatment with interferon-beta (IFN-beta), cytosine-5-DNA methyltransferase (M. SssI) and 5-aza-2'-deoxycytidine. Differences in expression levels between haplotypes were determined by analysis of variance (ANOVA).

RESULT

Promoter haplotypes with the miscarriage-associated -725G allele were expressed at significantly higher levels in all culture conditions compared with otherwise identical haplotypes that had a -725C or -725T allele.

CONCLUSION

Variation in the HLA-G promoter region influences transcription rates. Contrary to expectations, increased expression of HLA-G may be disadvantageous in some pregnancies.

[Influences of orthodontic tooth movement on estrous cycle and estrogen in rats]

OBJECTIVE

To explore the influences of orthodontic tooth movement on estrous cycle and estrogen in female rats.

METHODS

Two hundred female rats were divided into control group, one-time activation group, four-time activation group and sham-operated group. Each group was divided again into 4 sub-groups according to the different stage of the estrous cycle. The force-loading groups received repeated intermittent force. Serum estrogen was measured and the change of estrous cycle was recorded.

RESULTS

There were significant variations in the estrogen level among the groups which received mechanical force during the same stage of the estrous cycle (P < 0.01) and among the subgroups within each group (P < 0.05). These experimental treatments affected the estrous cycle of the rats in the groups received force in metestrus and diestrus.

CONCLUSIONS

Estrus of rats was the appropriate time for the orthodontic force.

[Influences of applying force during the different stages of estrous cycle on orthodontic tooth movement of rats]

OBJECTIVE

To explore the effects of applying force during the different stages of estrous cycle on orthodontic tooth movement of rats, so as to offer an experimental princinple for women's orthodontic treatment.

METHODS

80 female 3-month-old Wistar rats, which had a stable and five-day estrous cycle, were used. They were randomly divided into control groups and loading-force groups. Each group was divided again into 4 sub-groups according to the different stages of the estrous cycle. The loading-force groups received repeated intermittent orthodontic force for four times seperately during the same stage of the estrous cycle. The distance between upper incisor and the first molar on the left was measured. The data were analyzed by One-way ANOVA, S-N-K.

RESULTS

There were significant variations in the amount of tooth movement among the groups which received the mechanical force during the different stages of the estrous cycle (P <0.01). There were significant variations in the amount of tooth movement between the groups received force during pre-estrus and estrus (P <0.05). There were not significant variations between the groups received force during metestrus and diestrus (P > 0.05). The largest amount of tooth movement was in estrus group and smallest in pre-estrus one.

CONCLUSION

The effect of tooth movement depended on which stage of estrous cycle was chosen to be the time of applying orthodontic force.

[Study on the relationship between 22q11 microdeletion and congenital heart disease]

To investigate if microdeletion of chromosome 22q11 is an epidemiologically important cause of congenital heart disease (CHD), we studied 25 cases with CHD phenotypes. Venous blood samples were tested by fluorescence in situ hybridization (FISH) for microdeletion of 22q11. Among 23 cases with simple CHD, 19 were shown not to have microdeletion of 22q11 and the other 4 cases were shown to have 22q11 microdeletion. Microdeletion of 22q11 was found in 2 cases with Tetralogy of Fallot (TOF) accompanied by multiple malformations. The results suggested that microdeletion of 22q11 was associated with CHD.

[Influence of basic fibroblast growth factors on the migration, proiferation of osteoblasts and periodontal ligament fibroblasts]

OBJECTIVE

In order to determine the influence of bFGF on the biological characteristics of osteoblasts and periodontal ligament cells, the author investigate the influence of bFGF on the migration, proliferation of osteoblasts and periodontal ligament fibroblasts between osteoblasts and fibroblasts.

METHODS

The forth generation of osteoblasts and periodontal ligament fibroblast were obtained and the wounding model in vitro of them was founded. The cells were cultured in mediums with or without bFGF. Their migration and proliferation were observed and measured.

RESULTS

Osteoblasts migrated faster than fibroblasts in common culture medium without bFGF and the periodontal ligament fibroblasts in culture medium with bFGF had higher migration rate than other groups. bFGF promoted the proliferation of both two kinds of cells.

CONCLUSION

bFGF could accelerate periodontal fibroblasts' proliferation and migration.

Conservation of the genomic structure and receptor-mediated signaling between human and rat IL-24

IL-24/MDA-7 is a new member of the IL-10 family of cytokines, which signals through two heterodimeric receptor complexes (IL-20R1/IL-20R2 and IL-22R/IL-20R2). Previously, we identified a rat gene named mob-5, which encodes a secreted protein that shares a high degree of homology with human IL-24. Expression of mob-5 and its putative cell surface receptors was shown to be upregulated by oncogenic ras. Here we show that not only do rat mob-5 and human IL-24 share a strikingly similar genomic structure but also that the rat MOB-5 protein can bind to and signal through the human IL-24 receptors. Like human IL-24, binding of the rat MOB-5 protein to the human IL-24 receptors leads to activation of the JAK/STAT pathway, which in turn supports receptor-dependent survival and proliferation of Ba/F3 cells. Furthermore, using human colon cancer cell lines with somatic knockout of either the mutant or the wild-type k-ras allele, we demonstrate that the human IL-24 receptors also are upregulated by oncogenic ras. Taken together, these results provide strong experimental evidence that MOB-5 is indeed the rat homolog of human IL-24.

[Interaction between osteoblasts and fibroblasts derived from same individual]

OBJECTIVE

In order to determine the effect of factors pertaining to the development and metabolism of periodontal ligament, the author investigated the interaction between osteoblasts and fibroblasts.

METHODS

The cell co-culture model was established by cell culture inserts. The expression difference of protein related to mineralization (ALP, Type I collagen) between these two kinds of cells cultured individually and co-cultured were evaluated.

RESULTS

Co-culture changed the ALPase activity of the two kinds of cells greatly .The ALP expression of osteoblasts decreased, but the ALP expression of periodontal ligament fibroblasts increased. The Col-I expression of these two kinds of cells did not change significantly when they were co-cultured.

CONCLUSION

Periodontal ligament fibroblast could restrain the osteogenesis function of osteoblast, while osteoblast could induce the differentiation of fibroblast when both of them existed in periodontal tissue.

The sugary-type isoamylase gene from rice and Aegilops tauschii: characterization and comparison with maize and arabidopsis

Genes for an isoamylase-like debranching enzyme have been isolated from rice and Aegilops tauschii, the donor of the D genome to wheat. The structures of the genes are very similar to each other and to the maize SU1 isoamylase gene and consist of 18 exons spread over approximately 7.5 kb. Southern analysis and fluorescent in situ hybridization showed the Ae. tauschii gene to be located in the proximal region of the short arm of chromosome 7D, thus showing synteny with the localization of the rice isoamylase gene on rice chromosome 8. Analysis of the expression pattern of wheat sugary isoamylase genes indicates that they are strongly expressed in the developing endosperm 6 days after flowering. Three distinct Sugary-type cDNA sequences were isolated from the wheat endosperm that are likely to correspond to the products of the three genomes. The deduced amino acid sequence of rice and wheat Sugary-type isoamylase is compared with other sequences available in the database and the results demonstrate that there are three types of isoamylase sequences in plants: those containing 18 exons (the Sugary-type isoamylase gene), those containing 21 exons, and those containing only 1 exon. It is possible that different combinations of isoamylase genes are expressed in different tissues.

[A study on the correlation between facial growth pattern and posterior-anterior ratio]

OBJECTIVE

This study aimed at finding sensitive indicators in diagnosing facial growth pattern by studying the relationship between the indicators which can reflect facial growth pattern according to the previous studies and posterior-anterior ratio.

METHODS

The cephalometric radiographs of 61 teenage children were measured, the posterior-anterior ratio and the other 12 indicators including Y-axis angle, facial axis angle, cranial basal angle, and the four angles (The sagittal horizontal planes were analyzed using statistic methods.

RESULTS

The MP-SN angle was significantly coincided with the posterior-anterior ratio and Pearson coefficient is -0.922, and little correlation was found between the angles of four sagital horizontal planes and the posterior-anterior ratio. The positive correlation was found between the length of mandibular ramus and posterior-anterior ratio.

CONCLUSION

The sensitive indicators for confirming facial growth pattern are the posterior-anterior ratio and the MP-SN angle.

Telomeres at the chromosome X(p) might be critical in limiting the proliferative potential of human cells

Normal human somatic cells can only divide for a limited number of times. This phenomenon has been regarded as a reflection of individual aging at the cellular level. Experimental evidences suggest that a cell's division potential is limited by the physical length of telomeres that gradually shorten through successive cell divisions. At present, it is not clear whether such a limit is imposed by the overall shortening of all telomeres or the shortening of certain critical ones. Computer simulations have suggested that among the 92 telomeres in human cells, two specific telomeres might be preferentially involved in such process. Recent experiment has shown that in a culture of male human cells, the length of the telomeres at the chromosome X(p) is reserved over the later passages during clonal proliferation. This unique feature, if can be further confirmed in other cells, implies a critical role of the telomeres at X(p) in limiting the proliferation capacity of human cells.

An analysis of relationships among plant community phenology and seasonal metrics of Normalized Difference Vegetation Index in the northern part of the monsoon region of China

This study focuses on relationships between the phenological growing season of plant communities and the seasonal metrics of Normalized Difference Vegetation Index (NDVI) at sample stations and pixels overlying them, and explores the procedure for determining the growing season of terrestrial vegetation at the regional scale, using threshold NDVI values obtained by surface-satellite analysis at individual stations/pixels. The cumulative frequency of phenophases has been calculated for each plant community and each year in order to determine the growing season at the three sample stations from 1982 to 1993. The precise thresholds were arbitrarily set as the dates on which the phenological cumulative frequency reached 5% and 10% (for the beginning) and 90% and 95% (for the end). The beginning and end dates of the growing season were then applied each year as time thresholds, to determine the corresponding 10-day peak greenness values from NDVI curves for 8-km2 pixels overlying the phenological stations. According to a trend analysis, a lengthening of the growing seasons and an increase of the integrated growing season NDVI have been detected in the central part of the research region. The correlation between the beginning dates of the growing season and the corresponding threshold NDVI values is very low, which indicates that the satellite-sensor-derived greenness is independent of the beginning time of the growing season of local plant communities. Other than in spring, the correlation between the end dates of the growing season and the corresponding threshold NDVI values is highly significant. The negative correlation shows that the earlier the growing season terminates, the larger the corresponding threshold NDVI value, and vice versa. In order to estimate the beginning and end dates of the growing season using the threshold NDVI values at sites without phenological data from 1982 to 1993, we calculated the spatial correlation coefficients between NDVI time-series at each sample station and other contiguous sites year by year. The results provide the spatial extrapolation area of the growing season for each sample station. Thus, we can use the threshold NDVI value obtained at one sample station/pixel for a year to determine the growing season at the extrapolation sites with a similar vegetation type for the same year.

Glutamate induced modulation of free Ca(2+) in isolated inner hair cells of the guinea pig cochlea

To explore the possible involvement of glutamate (Glu) in modulation of inner hair cell (IHC) functions, the glutamate (Glu) induced changes in intracellular free Ca(2+) ([Ca(2+)]i) concentration in isolated IHCs and outer hair cells (OHCs) of the guinea pig cochlea were investigated with fluo-3, a fluorescent probe for intracellular Ca(2+). Their unique flask shape identified the IHCs with a distinct neck and spherical base with a large spherical nucleus. Normal cell shapes could be maintained for about 2 h. Fluorescence of fluo-3 was distributed in the whole isolated IHC with brighter staining nuclei. Static [Ca(2+)]i remained constant within the observation period in the absence of Glu. In the presence of a low concentration of Glu (3.85 microM), there was an increase of [Ca(2+)]i in IHCs, whereas no obvious [Ca(2+)]i change was found in OHCs. The increase of the fluorescence in IHCs reached peak level at 180 s and then gradually reduced at 400 s after the administration of Glu. The increases of [Ca(2+)]i were observed in nine of 10 IHCs, but one IHC did not show any change. For 10 of the observed OHCs, seven showed no [Ca(2+)]i change, and three showed minor reduction of [Ca(2+)]i. The increase of the Glu concentration resulted in a corresponding change of [Ca(2+)]i in the IHCs after three times administration of Glu. These results suggest that Glu acts on the IHCs presynaptic autoreceptor in a positive feedback manner.

[Down-regulation of ETA receptor of vascular smooth muscle cells by 17 beta-estradiol]

In the present study, the effects of 17 beta-estradiol on vascular reactivity of ovariectomized rats and proliferation of cultured rat aortic smooth muscle cells were studied. The vascular reactivity was significantly increased in ovariectomized rats compared with the sham-operated animals. The selective ETA receptor antagonist BQ123 inhibited the increase in [3H]-TdR incorporation in response to ET-1 on vascular smooth muscle cells (VSMCs). 17 beta-estradiol also attenuated the ET-1 effects in a dose-dependent manner. The results of RT-PCR and Western blot show that expression of ETA receptor was decreased after treatment with 17 beta-estradiol. The effect of 17 beta-estradiol was partially inhibited by estrogen receptor antagonist tamoxifen. The above results demonstrate that proliferation of VSMCs stimulated by ET-1 was mainly mediated through ETA receptor. Due to the down-regulation of ETA receptor and mediation of estrogen receptor, 17 beta-estradiol inhibits the ET-1-induced proliferation of VSMCs and decreases the vascular reactivity of ovariectomized rats.

Complete genomic sequence of 195 Kb of human DNA containing the gene GABRG2

GABA (gamma-aminobutyric acid), as the main inhibitory neurotransmitter in the brain, plays an essential role for the overall balance between neuronal excitation and inhibition by acting on GABAA receptors, which are ligand-gated chloride channels. Impaired GABAergic function contributes to certain forms of epilepsy, schizophrenia, Alzheimer's Disease, and other neurological disorders. In order to identify possible genetic features and to further study biological regulation of GABAA receptor genes whose promoter elements and sequence anomalies may contribute to epileptic disorders, as an initial step, we shot-gun sequenced a BAC clone, dj082c10 (195,909-bp in size), encompassing human gamma(2) subunit of GABAA receptor (GABRG2). It is, we believe, the first genomic sequence of the GABA receptor gamma subunit family. Four contigs were assembled from 2950 reads prior to gap in an average redundancy of eight folds over the entire region. The precision of the consensus sequence was predicted to be 99.999% after closing gaps and finishing weak regions. The nine exons of GABRG2 spans an 85-kb region that had 81 SINEs comprising 22.32%, and nine L1 elements comprising 3.40%, respectively. However, the density of L1 in the regions flanking GABRG2 gene (29.45% by 45 elements) is significantly higher than that within the gene. The length of GABRG2 introns varies in the range of 1.5 kb to 38.1 kb.

[Experimental study of in osteogenesis in duced by NIH-3T3 cells transfected with bone morphogenetic protein 3 gene]

OBJECTIVE

To investigate the gene expression, protein synthesis and inducing osteogenetic capacity of NIH-3T3 cells transfected with recombinant human bone morphogenetic protein 3 (rhBMP3) gene.

METHODS

Gene recombination technique was used to clone the BMP3 cDNA into PcDNA3 vector directly, and to form a recombined BMP3-PcDNA3 cDNA, which was introduced into NIH-3T3 cells by means of lipofectamine transfer. The total RNA of transfected NIH-3T3 cells was then extracted to verify the mRNA expression of BMP3 using Northern blot method. BMP3 protein synthesis and AKP activity in the transfected cells was checked. Then, the NIH-3T3 cells transfected with BMP3 gene were injected into nude mouse muscle to evaluate the inducing osteogenesis in the muscle.

RESULTS

BMP3 gene had been inserted into PcDNA3 vector successfully. There was BMP3 mRNA expression in the total RNA of NIH-3T3 cells with the peak level appearing in the 6th week after transfection, and BMP3 protein was found in NIH-3T3 cells, and the AKP level is much higher in the transfected NIH-3T3 cells than in non-transfected NIH-3T3 cells. Histologic examination revealed that there were a large number of chondrocytes and trabeculae seen in the nude mouse muscle 4 weeks after injection of the transfected NIH-3T3 cells.

CONCLUSION

BMP3 is a protein that possesses osteogenetic effect. After transfection with BMP3-PCDNA3, BMP3 mRNA expression and protein formation can be found in NIH-3T3 cells, and the transfected NIH-3T3 cells have the effect of inducing osteogenesis in vivo.