Biomedical subjects

Hui Gao

Publications and source records attributed to Hui Gao.

48 records · Page 3Linked to original sources

PubMed2003

[Comparison of craniofacial skeletal structures in adult high-angle and low-angle facial skeletal types].

OBJECTIVE: The purpose of this study was to compare the differences of craniofacial characteristics of adult high-angle and low-angle facial skeletal types. METHODS: The subjects consisted of 37 yellow race adults (17 high-angle, 20 low-angle). Fifty-three items of cephlometic radiographs were analyzed. RESULTS: The angle of N-S-Ar and N-S-Ba, the distance of Ptm-A, Co-Go, Po-NB, and S-Go, and the thickness of the mandibular symphysis in high-angle group were smaller than these in low-angle group. The angles of SN-OP, FH-OP, PP-OP, SN-MP, FH-MP, PP-MP, S-Ar-Go, mandibular angle(Ar-Go-Me), Y-angel and SUM, the distance of S-Co, N-Me, and ANS-Me in high-angle group were greater than these in low-angle group. The index of FHI, N-ANS/N-Me, and N-ANS/ANS-Me were smaller, and ANS-Me/N-Me larger in high-angle group. Although the means of Go-Po and FH-RP were smaller in high angle group, but no statistical difference were found. CONCLUSION: The craniofacial morphology of adult high-angle and low-angle facial skeletal types demonstrated significant differences, especially in lower facial form.

Adolescent↗

PubMed2003

Mus81 endonuclease localizes to nucleoli and to regions of DNA damage in human S-phase cells.

Mus81 is a highly conserved substrate specific endonuclease. Human Mus81 cleaves Holliday junctions, replication forks, and 3' flap substrates in vitro, suggesting a number of possible in vivo functions. We show here that the abundance of human Mus81 peaks in S-phase and remains high in cells that have completed DNA replication and that Mus81 is a predominantly nuclear protein, with super accumulation in nucleoli. Two RecQ related DNA helicases BLM and WRN that are required for recombination repair in human cells colocalize with Mus81 in nucleoli. However, the nucleolar retention of Mus81 is not dependent on the presence of BLM or WRN, or on ongoing transcription. Mus81 is recruited to localized regions of UV damage in S-phase cells, but not in cells that are blocked from replicating DNA or that have completed replication. The retention of human Mus81 at regions of UV-induced damage specifically in S-phase cells suggest that the enzyme is recruited to the sites at which replication forks encounter damaged DNA. The nucleolar concentration of Mus81 suggests that it is required to repair problems that arise most frequently in the highly repetitive nucleolar DNA. Together these data support a role for Mus81 in recombination repair in higher eukaryotes.

Adenosine Triphosphatases↗

PubMed2003

Estrogen receptor (ER)-beta reduces ERalpha-regulated gene transcription, supporting a "ying yang" relationship between ERalpha and ERbeta in mice.

Estrogen is of importance for the regulation of adult bone metabolism. The aim of the present study was to determine the role of estrogen receptor-beta (ERbeta) in vivo on global estrogen-regulated transcriptional activity in bone. The effect of estrogen in bone of ovariectomized mice was determined using microarray analysis including 9400 genes. Most of the genes (95% = 240 genes) that were increased by estrogen in wild-type (WT) mice were also increased by estrogen in ERbeta-inactivated mice. Interestingly, the average stimulatory effect of estrogen on the mRNA levels of these genes was 85% higher in ERbeta-inactivated than in WT mice, demonstrating that ERbeta reduces estrogen receptor-alpha (ERalpha)-regulated gene transcription in bone. The average stimulatory effect of estrogen on estrogen-regulated bone genes in ERalpha-inactivated mice was intermediate between that seen in WT and ERalphabeta double-inactivated mice. Thus, ERbeta inhibits ERalpha-mediated gene transcription in the presence of ERalpha, whereas, in the absence of ERalpha, it can partially replace ERalpha. In conclusion, our in vivo data indicate that an important physiological role of ERbeta is to modulate ERalpha-mediated gene transcription supporting a "Ying Yang" relationship between ERalpha and ERbeta in mice.

Animals↗

PubMed2003

Analysis of comparative genomic hybridization and loss of heterozygosity in 43 primary gastric carcinomas.

OBJECTIVE: To investigate common chromosomal changes and the LOH frequency of microsatellite loci in primary gastric cancer samples in order to locate the deleted regions in which human gastric cancer related genes might exist. METHODS: Comparative genomic hybridization (CGH) was used to define global chromosomal aberrations in 43 primary gastric tumors. Based on the results of CGH, analysis of loss of heterozygosity (LOH) was performed in chromosome 19 in which the loss was first discovered in the gastric cancers. The PCR-based approach was used to investigate 22 loci, which are spaced at 1.1 - 10.9 cM intervals throughout chromosome 19. The amplified PCR fragments were subjected to electrophoresis in PAGE gel and analyzed with Genescan trade mark and Genotyper trade mark. RESULTS: CGH analysis revealed gains in chromosome 3p (8/43), 8q (8/43), 20 [20 (9/43), 20p (7/43), 20q (4/43)], 12q (16/43), 13q (12/43) and losses in 19 [19 (15/43)], 7 [17 (8/43), 17p (10/43)], 16 (10/43) and 1p (11/43). Among the 43 evaluated samples, the most frequent LOH was detected at locus D19S571 (27.81%). CONCLUSIONS: The tumorigenesis of gastric cancer includes several chromosomal changes. The aberration of chromosome 19 was the first common change founded in gastric cancer. The region near the D19S571 might harbor potential genes related to the tumorigenesis of gastric cancer.

Chromosomes, Human, Pair 19↗

PubMed2003

[Change of protein catabolism and immunocompetence in severely burned patients after operations and the therapeutic effect of recombinant human growth hormone].

OBJECTIVE: To investigate the changes in protein catabolism and immunocompetence in severely burned patients after operations and observe the therapeutic effect of recombinant human growth hormone (rhGH) in these patients. METHODS: The changes in plasma protein concentration and immune function and the clinical results of 38 severely burned patients after three operations were retrospectively analyzed. These patients were assigned to GroupI(control, n=20) and GroupII (rhGH treatment, n=18), and matched for age, total body surface area (TBSA), surgical approaches and times, perioperative bleeding volume and nutrition support etc. The patients in groupII received intramuscular injection with 0.2-0.4 U/d x kg x b.w. rhGH after the first operation, till the healing of the wounds. RESULTS: The concentration of retina-binding protein, transferrin, prealbumin, albumin, and IgG, the number of CD4 and CD8 cells, as well as the ratio of CD4/CD8 cells prior to the operation were below the normal levels in the two groups of patients. All these indexes in GroupII recovered to a great extent after three operations and were significantly higher than those in GroupI(P<0.05). CONCLUSION: Nutritious state and immunocompetence of patients with severe burns are severely compromised after operations, and nutrition support and rhGH treatment may produce rapid improvement of the patients' conditions.

Adolescent↗

PubMed2002

Reversal of P-glycoprotein mediated multidrug resistance by a newly synthesized 1,4-benzothiazipine derivative, JTV-519.

A newly synthesized 1,4-benzothiazipine derivate, 4-[3-(4-benzylpiperidin-1-yl) propionyl]-7-methoxy-2,3,4,5-tetrahydro-1, 4-benzothiazepine monohydrochloride (JTV-519) was examined for its ability to reverse P-glycoprotein (P-gp) and multidrug resistance protein 1 (MRP1) mediated multidrug resistance (MDR) in K562/MDR and KB/MRP cells, respectively. JTV-519 at 3 microM reversed the resistance of K562/MDR cells to vincristine (VCR), taxol, etoposide (VP16), adriamycin (ADM) and actinomycin D and at 0.5 or 1 microM reversed their resistance to STI571. JTV-519 at 10 microM enhanced the accumulation of ADM in K562/MDR cells to the level in parental K562 cells and inhibited the efflux of ADM from K562/MDR cells. Photoaffinity labeling of P-gp with 3H-azidopine was almost completely inhibited by 500 microM JTV-519. JTV-519 at 3 microM also partially reversed the resistance of KB/MRP cells to VCR and at 500 microM partially inhibited the photoaffinity labeling of MRP1 with (125)I-II-azidophenyl agosterol A (125I-azidoAG-A). These results suggest that JTV-519 reversed the resistance to the anti-cancer agents in P-gp and MRP1 overexpressing multidrug-resistant cells by directly binding to P-gp and MRP1, and competitively inhibiting transport of the anti-cancer agents.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2002

A draft sequence of the rice genome (Oryza sativa L. ssp. indica).

We have produced a draft sequence of the rice genome for the most widely cultivated subspecies in China, Oryza sativa L. ssp. indica, by whole-genome shotgun sequencing. The genome was 466 megabases in size, with an estimated 46,022 to 55,615 genes. Functional coverage in the assembled sequences was 92.0%. About 42.2% of the genome was in exact 20-nucleotide oligomer repeats, and most of the transposons were in the intergenic regions between genes. Although 80.6% of predicted Arabidopsis thaliana genes had a homolog in rice, only 49.4% of predicted rice genes had a homolog in A. thaliana. The large proportion of rice genes with no recognizable homologs is due to a gradient in the GC content of rice coding sequences.

Arabidopsis↗

PubMed2002

Novel roles of liver X receptors exposed by gene expression profiling in liver and adipose tissue.

Liver X receptor (LXR) alpha and LXRbeta are nuclear oxysterol receptors whose biological function has so far been elucidated only with respect to cholesterol and lipid metabolism. To expose novel biological roles for LXRs, we performed genome-wide gene expression profiling studies in liver and white and brown adipose tissue from wild-type (LXRalpha(+/+)beta(+/+)) and knockout mice (LXRalpha(-/-)beta(-/-)) treated with a synthetic LXR agonist. By an adapted statistical analysis, we detected 319 genes significantly regulated by LXR agonist treatment in wild-type but not in knockout mice, fulfilling most stringent criteria with an overall confidence of 94%. Down-regulation of essential enzymes of gluconeogenesis in liver could point to possible beneficial effects of LXR agonists in diabetes mellitus. LXR agonist treatment also altered expression of genes involved in steroid hormone synthesis and growth hormone receptor signaling, emphasizing a potential impact on endocrine function. Notably, LXR agonist treatment up-regulated CYP4A10 and CYP4A14 together with cytochrome P450 reductase, indicating a possible enhancement of microsomal lipid peroxidation. In conclusion, these gene expression profiling data identify novel areas of regulation by LXRs and provide a highly valuable basis for further research on the biological functions of these nuclear receptors and the pharmacological characteristics of their ligands.

Adipose Tissue↗

PubMed2002

Identification of estrogen-regulated genes of potential importance for the regulation of trabecular bone mineral density.

Estrogen is of importance for the regulation of trabecular bone mineral density (BMD). The aim of this study was to search for possible mechanisms of action of estrogen on bone. Ovariectomized (OVX) mice were treated with 17beta-estradiol. Possible effects of estrogen on the expression of 125 different bone-related genes in humerus were analyzed using the microarray technique. Estrogen regulated 12 of these genes, namely, two growth factor-related genes, 8 cytokines, and 2 bone matrix-related genes. Five of the 12 genes are known to be estrogen-regulated, and the remaining 7 genes are novel estrogen-regulated genes. Seven genes, including interleukin-1 receptor antagonist (IL-1ra), IL-1receptor type II (IL-1RII), insulin-like growth factor-binding protein 4 (IGFBP-4), transforming growth factor beta (TGF-beta), granulocyte colony-stimulating factor receptor (G-CSFR), leukemia inhibitory factor receptor (LIFR), and soluble IL-4 receptor (sIL-4R) were selected as probable candidate genes for the trabecular bone-sparing effect of estrogen, as the mRNA levels of these genes were highly correlated (r2 > 0.65) to the trabecular BMD. The regulation of most of these seven genes was predominantly estrogen receptor alpha (ER-alpha)-mediated (5/7) while some genes (2/7) were regulated both via ER-alpha and ER-beta. In conclusion, by using the microarray technique, we have identified four previously known and three novel estrogen-regulated genes of potential importance for the trabecular bone-sparing effect of estrogen.

Animals↗

PubMed2002

[Genescan analysis of non-small cell lung cancer in the long arm of chromosome 6].

OBJECTIVE: To investigate if there are microsatellite loci in the long arm of chromosome 6 that have close relationship with non-small cell lung cancer. METHODS: Multiple PCR approach was used to analyze the 18 loci in the long arm of chromosome 6. The PCR products were analyzed in PAGE, and then the electrophoresis maps were analyzed with Gene Scan(TM) and Genotyper(TM). RESULTS: There were different frequencies of loss of heterozygosity (LOH) in different loci (varying from 3.85% to 38.45%). The total frequency of LOH in 41 gastric cancers was 58.5%(24/41). Eight loci with the LOH frequency higher than 20% were mainly located in 2 regions: 6q24 and 6q27. The accurate location is 6q24-6q25.3 [D6S1699(35%), D6S409(23.33%), D6S441(33.33%)] and 6q26-27 [D6S1550(38.45%), D6S264(20%), D6S1585(25%), D6S446(33.33%), D6S281(30.77%)]. CONCLUSION: There may be tumor suppressor genes located in the region of 6q24 and 6q27, which have close relationship with non-small cell lung cancer.

Carcinoma, Non-Small-Cell Lung↗

PubMed2002

[A modified least mean square (LMS) algorithm with variable step-size for an adaptive noise canceller].

Objective. To study a modified Least Mean [correction of Mear] Square (LMS) algorithm that can be applied in aerospace and aviation fields. Method. A modified LMS algorithm was proposed and step-size was calculated by estimated signal noise ratio (SNR) of input signal. Parameters of filter were adjusted automatically until optimal estimation of disturbed speech was obtained. Result. Output SNR of estimated speech was increased respectively to 18.2 dB, 22.1 dB and 25.2 dB, when input SNR of disturbed speech was -6 dB, 0 dB, 6 dB. Conclusion. The performance of the modified algorithm has obvious advantages over that of NLMS algorithm. The results may be advantageous to related application of adaptive noise canceller (ANC) in aerospace and aviation fields.

Acoustics↗

PubMed2002

[McNamara cephalmetric analysis of the 67 chengdu adolescents with normal occlusions].

OBJECTIVE: The purpose of this study was to obtain the normal value of McNamura analysis for Chengdu adolescents with normal occlusion of early permanent dentition. METHODS: McNamara analysis was conducted on the basis of the lateral cephalograms of 67 Chengdu adolescents with normal occlusions, and the obtained data was compared with that of Shanghai adolescents and McNamara. RESULTS: There was no difference in the normal value of McNamara analysis between male and female Chengdu adolescents. The Comparative results between Chengdu and Shanghai adolescents indicated significantly larger values of Shanghai adolescents in effective middle facial lengths, mandibular lengths and lower anterior facial heights. The vertical distances from the upper incisor to point A and, from the lower incisor to A-Po line of Chengdu adolescents were larger than those of white adolescents. CONCLUSION: There is significantly difference in values of normal occlusions of McNamara analysis among different regions and different races.

Asian People↗