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Biomedical subjects

Yi Zhang

Publications and source records attributed to Yi Zhang.

At least 271 records · Page 15Linked to original sources
PubMed2005

[Progress of study on placenta mesenchymal stem cells--review].

Recently mesenchymal stem cells have been successfully obtained from various sources of human body, including bone marrow, compact bone, peripheral blood, adipose tissue, cord blood, amniotic fluid and other fetal tissues. Placenta, as a temporary organ keeping substance exchange between mother and fetus, consisted of decidua basalis and chorion frondosum, which derived from cytotrophoblast and extraembryonic mesoderm, thus involved both primary embryonic cells and adult stem cells. As a castoff after parturition, along with the ease of accessibility, lack of ethical concerns, placenta may be an attractive source of mesenchymal stem/progenitor cells for basic and clinical application. Therefore, the origin, isolation, characteristics and potential uses in future therapy are mainly reviewed in this paper.

Cell Differentiation↗
PubMed2005

[Molecular Cloning of Smooth Muscle Calponin h1 in SHeep.].

It was found that the level of Calponin h1 (CaP h1) mRNA was significantly up-regulated by Estrogen in the myometrium of sheep towards the end pregnancy. Although the CaP h1 has been widely used as a reference gene to observe the changes of expression level of other genes, the full-length gene in sheep has not been obtained. With the oligo nucleotide primers according to human, mouse and pig CaP h1 mRNA, the full-length cDNA of CaP h1 was cloned by 5'- and 3'-RACE (Genbank accession number = AY327118). The cDNA was 1499bp in length and contained a complete open reading frame of 891 bp, encoding a protein of 297 amino acid residues. 5'-and 3'-UTR was 79 bp and 529bp, respectively. With PCR-SSP approaches,the genomic DNA of sheep CaP h1 was obtained .It showed that the gene has 7 exons and 6 introns, spanning over 8kb(Genbank accession number of introns : AY771807,AY771808, AY771809, AY771810.) Homologous comparison indicated that the cDNA sequences are highly conserved across the species. The highest homology was found in wild pig (92%), followed by human (88%), rat (81%), mouse (81%) and chicken (79%). The intron sequence and length showed a large variation among species (>50%).

Amino Acid Sequence↗
PubMed2005

[Experimental induction of immunity by anti-idiotypic vaccines against small-cell-lung cancer].

OBJECTIVE: To investigate the efficacy of anti-idiotype antibody 3F6 and its single-chain variable fragment (3F6 ScFv) to induce humoral and cellular immune responses against small-cell-lung cancer (SCLC). METHODS: 3F6 and 3F6 ScFv (Ab2) were used to immunize BALB/c mice. The reaction of antibodies (Ab3) with specific antigen on NCI-H128 cells was tested by ELISA and Western blot, and the antibody binding inhibition assays were performed by competitive Western blot. Cellular immunity against SCLC induced by Ab2 was detected by a delayed-type hypersensitivity response and mouse lymphocyte proliferation assay. RESULTS: The sera immunized with Ab2 showed significant reaction (P < 0.001, as compared to control sera) with SCLC-specific antigen on NCI-H128 cells and specifically competed the binding of 2F7 (Ab1) to the specific antigen. DTH responses challenged with NCI-H128 cells were significantly (P < 0.001) stronger in mice immunized with Ab2 as compared to mice immunized with normal mouse IgG. T cell proliferation was significantly higher in Ab2-immunized mice (P < 0.05) than in control mice. CONCLUSION: The two kinds of anti-idiotypic antibodies successfully mimic the SCLC-specific antigen on NCI-H128 cell and induce strong humoral and cellular immune responses to SCLC-specific antigen in syngeneic mice. They may become novel vaccines against human small-cell-lung cancer and worthy of further investigation.

Animals↗
PubMed2005

[Concentration and distribution characterization of polycyclic aromatic hydrocarbons in airborne particles with different sizes].

Airborne particles with different sizes were collected in 2003 at two sampling sites(urban border and suburban area) of Beijing. Compositions of polycyclic aromatic hydrocarbons were detected by GC/MS. The results show that total concentrations of 17 PAHs ranged between 0.84 and 152.23 ng/m3, in urban border area were 1.07 - 6.60 times higher than those measured in suburban area. The total concentration of PAHs increased with decreasing ambient temperature (winter > autumn > spring > summer). About 68.4% - 84.7% of PAHs were absorbed on particles having aerodynamic diameter < or = 2.0 microm. The distribution of PAHs varies with the size of the molecules. Nearly bimodal distribution was found for two- and three-rings PAHs, four- to six-rings PAHs, however, followed unimodal distribution. The overall mass median diameter (MMD) for PAHs decreases with increasing molecular weight. Higher pollution level of PAHs in wintertime is probably ascribed to domestic heating and lower ambient temperature.

Air Pollutants↗
PubMed2005

[Sequencing analysis of the control region and intron1 region and characterization of two novel microsatellites in obese gene of pig].

For the first time, a 16 kb fragment of the porcine Ob gene, namely intron1, exon1, 5' region of Ob gene, was restrictively analyzed and sequenced by the primers designed in the portion of the swine Ob sequence. The first small 38 bp untranslated exon1 is located 11.1 kb upstream of the initiator ATG codon, and two novel microsatellites SW200 and SW160 are found in intron1. Promoter analysis of several putative binding sites revealed that this 300 bp promoter located at -1 to -300, including C/EBP and two Sp1, may be as effective as the longer promoter in directing leptin transcription. To examine microsatellites association with important economic traits, we statistically analyzed genotypes and alleles of the two microsatellites. Statistical analysis carried out by SAS 8.2 revealed significant positive correlation between the two microsatellites genotypes and the litter size in first parity of Erhualian.

5' Untranslated Regions↗
PubMed2005

[Differentiation of mouse bone marrow mesenchymal stem cells into hepatocyte in vivo].

To explore the possibility of mouse bone marrow mesenchymal stem cells (BMSCs) differentiating into hepatocyte in vivo, the BMSCs isolated from donor male BALB/C mice at age of 6-8 weeks were transplanted to female BALB/C mice as recipients by transfusion via tail vein or direct liver injection. By the end of 1st, 2nd, 4th weeks after transplantation, the Y chromosome positive and albumin expression positive hepatocytes were detected from the recipient female mouse liver tissue by fluorescence in situ hybridization (FISH ) and immunohistochemistry (IHC). In the two groups of direct liver injection, no matter whether the donor cells are fresh isolated bane marrow cells or passage 3 cells, the Y chromosome positive cells with albumin expression simultaneously were detected by the end of the 1st week after transplantation. Similar result has been observed in the other subgroup of tail vein injection, but only by the end of the 2nd week after transplantation. BMSCs are capable of differentiating into hepatocyte in vivo.

Animals↗
PubMed2005

[A polymorphism of kynureninase gene in a hypertensive candidate chromosomal region is associated with essential hypertension].

OBJECTIVE: To identify single nucleotide polymorphisms (SNP) in the regulatory and coding regions of human kynureninase (KYNU) gene in a hypertensive candidate chromosomal region 2q14-q23 of Han Chinese, and to investigate the relationship between polymorphisms in KYNU and essential hypertension. METHODS: The SNPs in the promoter region and exons of the KYNU gene were detected by direct DNA sequencing. Genotyping of the nonsynonymous Lys412Glu (A/G) polymorphism was performed by DHPLC technology in 456 hypertensive patients and 430 normal controls. RESULTS: Sixteen SNP were identified in the KYNU gene, including 6 in the regulatory region and 2 in the coding region (both of them lead to substitution of amino acid). Significant differences between hypertensive patients and normal controls were observed for the distribution of alleles (chi(2) = 6.693, P = 0.035) and genotypes (chi(2) = 4.188, P = 0.041) of the Lys412Glu polymorphism in all subjects, and for the distribution of alleles in the subgroup of men (chi(2) = 4.424, P = 0.035). CONCLUSION: The Lys412Glu polymorphism of the KYNU gene in a hypertensive candidate chromosomal region is associated with essential hypertension in Han Chinese.

Adult↗
PubMed2005

[Impact of dose delivery of postoperative first-line chemotherapy on prognosis of stage III C epithelial ovarian carcinoma].

BACKGROUND & OBJECTIVE: Chemotherapy, which includes selecting appropriate drugs and suitable dose, is necessary to advanced ovarian carcinoma. Whether dose delivery affects prognosis of ovarian cancer is controversial. This study was to investigate the impact of dose delivery of postoperative first-line chemotherapy on prognosis of stage III C epithelial ovarian carcinoma. METHODS: Clinical data of 47 stage III C epithelial ovarian carcinoma patients, treated with cisplatin-based adjuvant first-line chemotherapy, were retrospectively analyzed. The relative cumulative dose (CD) and dose intensity (DI) were calculated for each drug and for all drugs combined (namely overall CD and overall DI). The impact of dose delivery on progression-free survival (PFS) and overall survival (OS) was analyzed. RESULTS: Median overall CD was 0.76, and median overall DI was 0.53; the median CD of cisplatin was 0.78, and the median DI of cisplatin was 0.57; the median CD of paclitaxel was 0.81, and the median DI of paclitaxel was 0.51. Dose delivery had no impact on PFS and OS of the patients. However, in non-paclitaxel chemotherapy subgroup, the higher overall CD, or CD for cisplatin, or DI for cisplatin, the longer PFS (P=0.01, P=0.03, P=0.01) and OS (P=0.01, P=0.04, P=0.01); in paclitaxel chemotherapy subgroup, dose delivery had no impact on PFS and OS. In suboptimal surgery subgroup (residual disease of > 2 cm), the higher DI for cisplatin, the longer PFS; the higher overall CD, or DI for cisplatin, the longer OS. In optimal surgery subgroup (residual disease of < or =2 cm), dose delivery had no impact on PFS and OS. Residual disease was the only independent prognostic factor of epithelial ovarian carcinoma. CONCLUSIONS: The dose delivery below standard level may influence survival of the patients with residual disease of > 2 cm or treated by non-paclitaxel chemotherapy. The diameter of residual disease is the independent prognostic factor of epithelial ovarian carcinoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

[Effect of caffeic acid, seopoletin and scutellarin on rat retinal neurons in vitro].

OBJECTIVE: To observe the effect of caffeic acid, seopoletin and scutellarin on rat retinal neurons in vitro and explore neuroprotection in glaucoma of Erigeron breviscapus. METHOD: The retinal of 18 post-natal 2-3 days Sprague-Dawley rats were dissociated into cell suspension with trypsin digestion. The cell suspension was implated in 96-well culture plates covered with hyaluronic acid and laminin in each well. After culturing for 3 days, caffeic acid, seopoletin and scutellarin were added to the cultures, continue to culture 2 days. Then, the A of living cells in each well was tested by MTT colorimetric microassay. Some of the 5-day culture cells were identified by Nissel technique. RESULT: Most of the living cells were retinal neurons by Nissel identification. The number of living cells increased significantly in high concentrations of caffeic acid, seopoletin and scutellarin compared with control group (P < 0.05, P < 0.01). CONCLUSION: caffeic acid, seopoletin and scutellarin can all promote retinal neurons to live in vitro, with caffeic acid being most effective.

Animals↗
PubMed2005

[Full face dermabrasion for acne scars].

OBJECTIVE: Dermabrasion has been of great value in plastic surgery. Dermabrasion was developed for a specific indication; however, within a very short time, the concept of dermabrasion found wide applicability. This study was to investigate the application of dermabrasion in the treatment of acne scars. METHODS: From Feb. 1996 to May 2004, a total of 110 patients with acne scar were treated with dermabrasion. RESULTS: Postoperatively, the curative results were achieved in 45 cases; good results in 40 cases and effective results in 25 cases. The study revealed that the patients at 18-46 years of age have good results. CONCLUSIONS: Dermabrasion is a good and safe technique to treat the scar of acne.

Acne Vulgaris↗
PubMed2005

[Study on amplification of ZNF217 in primary gastric carcinoma].

OBJECTIVE: To investigate amplification of zinc finger protein 217(ZNF217) and its association with clinicopathologic parameters in primary gastric carcinoma. METHODS: Semiquantitative polymerase chain reaction (PCR) was used to determine DNA copies of ZNF217 in the specimens from forty- seven cases with primary gastric carcinoma. RESULTS: There was no difference in DNA copies between tumor specimens and paratumor normal tissues. The incidence of ZNF217 amplification was 11.36% in gastric cancer. The amplification of ZNF217 was significantly associated with tumor size(P< 0.01) and intestinal type of stomach cancer(P< 0.05). CONCLUSION: Oncogene ZNF217 may play a role in specific tumor types or subtypes of gastric cancer. There may be other oncogenes associated with gastric carcinoma in 20(q)13.

Adult↗
PubMed2005

[Relationship between urokinase-type plasminogen activator expression and peritoneal metastatic potency in different gastric cancer cell lines].

OBJECTIVE: To compare the expression and activities of urokinase type plasminogen activator (uPA) among different gastric cancer cell lines and investigate their relations with peritoneal metastatic potency. METHODS: The uPA expression in 4 gastric cancer cell lines (AGS, SGC7901, MKN45, MKMN28) was detected using ELISA and Western blot methods. uPA activity was detected simultaneously using uPA activity kit. The gastric cancer cells were cultured with confluent mesothelial cells in 24-well plates or Boyden chambers for different times. The adhesive cells were counted directly under a microscope. The motility and invasion of gastric cancer cells were determined by MTT assay. RESULTS: Among four gastric cancer lines,the highest expression of uPA was found in SGC7901 and the highest uPA activity in MKN45, while the lowest expression and activity of uPA in AGS. Compared with the other three lines, MKN45 had stronger adhesion than MKMN28 (P< 0.05), SGC7901 (P< 0.05), and AGS (P< 0.01), but there were no significant differences in motility and invasion among MKN45, MKN28 and SGC7901. The adhesion,motility and invasion of AGS were weaker compared with those of the other three cell lines. CONCLUSION: The uPA expression and activity are significantly different among 4 gastric cancer cell lines, and positively correlated with their peritoneal metastatic potency.

Blotting, Western↗
PubMed2005

[Study of Rhizoma chuanxiong storage conditions].

OBJECTIVE: To study the different packing and storage life effect on the content of effective element in Rhizoma Chuanxiong, so as to guide the packing, moist, volatile oil and ferulic acid in Rhizoma Chuanxiong from two GAP base by the related determination method in supplyment of China Pharmocopeia (2000). And the content of total alkaloids was determined by acid dye colorimentry. RESULTS: The loss of effective element in Rhizoma Chuanxiong was the least when in vaccum packing, sack and weave packet. During the storage the content of moist and volatile oil decreased; the content of ferulic acid increased;the content variety of total alkaloids had no regulation. CONCLUSION: We should choose the sack and weave packet as the packing of Rhizoma Chuanxiong. If the quantity is small we should use vaccum packing. Conbined the changes of Rhizoma Chuanxiong effective element and the phenomenon of mildew and worm eaten during storage, we should not store it for long time.

Alkaloids↗
PubMed2005

[Reductive dechlorination of trichloroacetic acid by bioelectrochemically catalytic method].

Direct electrochemical behaviors of hemoglobin (Hb) immobilized on carbon nanotube (CNT) modified carbon paste electrode with adsorption were investigated. Cyclic voltammetry of Hb-CNT-modified electrode showed a pair of well-defined and nearly reversible peaks for HbhemeFe(III) /Fe(II) redox couple in pH = 7 PBS buffers. The electrocatalytic behaviors of Hb-CNT-modified electrode for the reductive dechlorination of trichloroacetic acid (TCA) were studied by cyclic voltammmetry and fixed-potential electrolysis technique, and the reductive mechanism of TCA was discussed by analysis of reduction products. The results showed that Hb-CNT-modified electrode possessed good electro-catalytic activity for reduction of TCA and the dechlorination of TCA was stepwise, following the pathway of trichloroacetic--> dichloroacetic--> monochloroacetic--> acetic. The dechlorination of TCA in waster water was investigated using a two-compartment flow reactor with working electrode compartment packed with Hb-CNT-modified graphite electrode. The conversion of TCA was 40.13% with electrolysis for 180 min at - 0.60V (vs. SCE).

Adsorption↗
PubMed2005

[Association of angiotensin I converting enzyme 2 gene polymorphism with essential hypertension in Chinese].

OBJECTIVE: To identify the genetic variants of angiotensin I converting enzyme 2 (ACE2) gene in a Chinese population and to determine whether the ACE2 gene polymorphisms are associated with essential hypertension (EH). METHODS: Seven hundred and forty-five patients with EH and 362 normal blood pressure controls were included in the study to assess the contribution of polymorphism of ACE2 gene. Direct DNA sequencing was performed to detect the single nucleotide polymorphisms (SNPs) in 20 subjects who were randomly selected from the EH patients. RESULTS: One SNP named G8790A located in the 4th base of the third intron was found in the 20 patients. The genotyping data indicate that the A allele frequency in male EH patients complicated with cardiac incompetence(55%) is significantly different from that in the control group(43.3%)(P<0.01). The A allele frequency in female patients with cardiac incompetence (56.1%) is higher than that in the controls (50.5%), but the difference does not reach statistical significance. CONCLUSION: The G8790A polymorphism may be related to the essential hypertension with cardiac incompetence in Chinese population. Additional investigation will be need to confirm the association.

Aged↗
PubMed2005

[Effects of low temperature at 10 degrees C on some antioxidant enzyme activities and ultrastructures of hypocotylar cells in mung bean and garden pea].

Mung bean (Phaseolus radiatus Linn.) and garden pea (Pisum satium Linn.), which were stressed 4 days under a low temperature of 10 degrees C, were used as materials to study the cold tolerance of plant with different resistance. On the 2nd and 3rd day under 10 degrees C stress, both the malondialdehyde (MDA) content and the superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities increased significantly in hypocotylar cells of mung bean, so did SOD activity in garden pea, but other physiological indexes in garden pea were not different from the non-treatment groups (Figs. 1-5). In hypocotylar cells of mung bean, SOD activity always maintain at the highest level in a period of time,and so does POD activity (Figs. 3, 4). Ultrastructural results after stress indicated as follows: (1) Plastids in hypocotylar cells of mung bean accumulated much starch (Plate I-6), whereas the form of plastids in hypocotylar cells of garden pea changed maskedly to become dumb-bell-shaped, round or irregular, with the last one being the most common form (Plate I-8, 12); (2) In both mung bean and garden pea, central vacuole was divided into small vacuoles (Plate I-4, 10), and the number of mitochondria increased and became aggregated (Plate I-3, 11, 12). Judging from the activities of protective enzymes and ultrastructures, 10 degrees C low temperature caused non-lethal, temporary injuries to hypocotyls ultrastructures in mung bean, but no visible injury at all, and even improved its cold tolerance to a certain degree in garden pea.

Catalase↗
PubMed2005

[Application of restorative laminoplasty combined with spinous process osteotomy and internal fixation for treatment of degenerative scoliosis].

OBJECTIVE: For treatment of mild degenerative scoliosis (DS) complicated with lumbar canal stenosis (LCS), posterior decompression and the spinal canal enlargement with spinous process osteotomy was performed in combination with fusion and pedicle screw instrument fixation. METHODS: Between 1999 and 2003, 18 male and 26 female elderly patients (with mean age of 63 years, ranging from 47 to 72 years) with DS complicated with LCS were treated with the described surgical procedures, including 25 with single segment lesion and 19 with involvement of 2 segments. A posterior medical incision from one vertebra superior to the target fusion area till the vertebral segment below it was made for spinal exposure. Undermining enlargement of the spinal canal was carried out according to the segments of the stenosis; in some cases the intervertebral disc was resected. Osteotomy was subsequently performed at the base of the spinous process, and the bony defect was covered with the spinous processes. Finally Moe fusion and Isola (17 cases) or Diapason (27 cases) instrument fixation were performed. The therapeutic effects were evaluated according to Oswestry scores and postoperative imaging examinations. RESULTS: The average follow-up period was 3 years, ranging from 1 to 4 years. Thirty-three patients were followed up for one year and 93.9% of them had excellent or good outcome; 27 patients were followed up of 2 years and showed a rate for excellent or good results of 88.9%. Both sagittal and transverse diameters of the lumbar spinal canal were increased obviously as found by CT scanning without spinal canal scar. A rate of 92.6% of the ostetomized spinous processes had bony fusions. Successful covering bone healing was achieved in a mean of 4 months after surgery. Compressive vertebral fractures superior to the fixed segments occurred in 2 cases, including 1 with pedicle screw loosening and the other with pedicle screw breakage. Another patient had delayed wound healing. No recurrence of LCS, spondylolisthesis and decompensation, or pseudarthrosis of the spine was observed in these cases. CONCLUSION: The described surgical procedures for DS can decrease the occurrence of spinal canal scar and promote the healing of the covering bone, and can be a satisfactory treatment for mild DS complicated with LCS in the lumbar sagittal curve.

Adult↗