Biomedical subjects

Ying Li

Publications and source records attributed to Ying Li.

358 records · Page 20Linked to original sources

PubMed2002

[Value of long-distance fetal heart rate monitoring on the pre-partum health care of the pregnant woman with umbilical cord loops].

OBJECTIVE: To explore the value of the long-distance fetal heart rate (FHR) monitoring on the pre-partum health care of self-monitoring at home for pregnant woman with the umbilical cord loops. METHODS: The umbilical cord loops was diagnosed by ultrasonography. In the study group, 896 pregnant women with the umbilical cord loops accepted long-distance FHR monitoring and the count of fetal movement (FM) as family-self monitoring methods, while in the control group, 1 914 pregnant women with the umbilical cord loops used the count of FM only as family-self monitoring method. Abnormal non-stress test (NST), variable deceleration, fetal distress, neonate asphyxia, fetal death, stillbirth, operative delivery rate were analyzed between the study and control group retrospectively. RESULTS: The incidence of NST reactive pattern and non- reactive pattern and the variable deceleration in long-distance FHR monitoring of the study group were significantly higher than those in routine FHR monitoring. The incidence of fetal distress in the study group (35.0%) was significantly higher than that in the control group (30.9%), while the incidence of neonatal asphyxia in the study group (3.5%) was significantly lower than that in the control group (5.6%). The incidence of outside hospital fetal death in the study group (0.1%) was significantly lower than that in the control group (0.8%). There were no significant differences of cesarean section rate, forceps or vacuum extractor delivery between the two groups (P > 0.05). CONCLUSIONS: This study suggested that the high variable rate in the long-distance FHR monitoring curve was related to the incidence of the fetal distress. It didn't increase the cesarean section rate and vaginal operative delivery rate, but decreased the neonatal asphyxia and outside hospital fetal death rate. The long-distance FHR monitoring combined with the count of FM may be a better family-self monitoring method for the pregnant women with the umbilical cord loops.

Cesarean Section↗

PubMed2002

[Related structures of the lateral sphenoid wall anatomy studies in CT and MRI].

OBJECTIVE: To study the anatomy of the Lateral Sphenoid Wall in CT and MRI in normal adults so as to provide a theoretical basis for imagine science. METHOD: High resolution CT in axial and coronal planes was conducted on 25 normal adults. MRI in axial and coronal planes, using SE T1 WI and FSE T2 WI was conducted on 20 volunteers. RESULT: 1. The pneumatisation of sphenoid sinus can be divided into two types: Pneumatisation of the sphenoid body and the one of sphenoid process. The former one can be subdivided into three categories: concha (2%), pre sellar (20%), sellar (78%). The latter can be subdivided into four categories: lesser wing (38%), greater wing (40%), pterygoid process (34%) and dorsum sellar (6%). 2. The thinnest part (< 1 mm) of the LSW is located at the inner wall of the optic nerve canal (96%), at the bony wall in the plane of sphenoethmoid recess (86%), the bony wall in the plane of the internal carotid artery (66%). 3. Over pneumatised sphenoid sinus could make the foramen rotumdum (64%) and pterygoid canal (44%) protrudes into the sphenoid cavity. CONCLUSION: Attention should be paid to the various mode of pneumatization around the optic nerve canal.

Adolescent↗

PubMed2002

[Prevalence survey on Cyclospora cayetanensis and Cryptosporidium ssp. in diarrhea cases in Yunnan Province].

OBJECTIVE: To investigate the prevalence and distribution characteristics of Cyclospora cayetanensis and Cryptosporidium ssp. infection in diarrhea cases of Yunnan Province. METHODS: To collect fresh faeces from diarrhea cases in 7 counties/cities, examine the specimens by direct smear with iodine staining and modified acid-fast staining. RESULTS: The infection rate of C. cayetanensis and Cryptosporidium ssp. was 3.97% and 5.29%, respectively. The infection rate of the two pathogenic coccidians was as high as 10.64% and 8.51% in preschool children. C. cayetanensis was found in 3 counties and Cryptosporidium in 6 counties. CONCLUSION: Both C. cayetanensis and Cryptosporidium ssp. are prevalent in Yunnan Province with the latter distributed more widely, and the two pathogens are more prevalent in preschool children.

Adolescent↗

PubMed2002

[Osteogenic potential of fibroblasts with reconstituted telomerase activity].

OBJECTIVE: To prevent the senescence of 'seed cells' for tissue engineering, the life span of human fibroblasts is extended by reconstitution of telomerase activity, and the osteogenic potential of these fibroblasts are tested. METHODS: The pGRN145 plasmids encoding human telomerase reverse transcriptase (hTERT) were introduced into the normal human primary fibroblasts by electroporation. Telomerase activity was analyzed by TRAP-PCR assay. The beta-galactosidase stain was used to indicate the signs of cell senescence. The hTERT positive fibroblasts were then induced to form bone nodules. The bone nodules were stained by tetracycline and Alizarin Red S. RESULTS: Stable telomerase activity could be detected in the transfected fibroblasts and no signs of cell senescence were found in the fibroblasts cultured for more than 50 doublings. The hTERT positive fibroblasts could form bone nodules when they were cultured in vitro induced by bone morphogentic protein 2 and tumor necrosis factor-alpha. CONCLUSION: The fibroblasts with reconstituted telomerase activity reserve their osteogenic potential.

Cells, Cultured↗

PubMed2002

[Inter-population and inter-individual effect of education attainment on men's behavior of smoking: China multi-center study of cardiovascular epidemiology].

OBJECTIVE: To study the inter-population and inter-individual effect of education attainment on men's behavior of smoking in China. METHOD: A cross-sectional study of 7,415 men, aged 35-59 years, from 15 population samples was carried out in 1998. Information on education attainment and smoking was collected by standardized questionnaires. The population samples were divided into 2 groups according to the proportion of men with college or above education attainment: group I had an average 25.8% of men with college or above education attainment, and group II had an average 2.0% of men with college or above education attainment. RESULTS: (1) In group I, the percent of ever smokers, current smokers, deeper smoker, and ever smokers with cessation due to disease and the average number of cigarettes per day for the smokers were significantly lower than in group II (66.2%, 56.4%, 34.4%, 47.8%, 17.2 cigarettes/day vs 75.8%, 64.4%, 40.3%, 58.4%, 20.4 cigarettes/day, respectively). (2) The percent of current smokers and the number of cigarettes decreased with increased education attainment in both groups. Taking the men with college or above education attainment in group I as reference, the odd ratio of smoking for those with high school education in group I was 1.8 (95% CI: 1.5-2.1), for those with middle school or lower education in group I was 2.0(95% CI: 1.7-2.5), for those with college or above education in group II was 1.4(95% CI: 0.9-2.1), for those with high school education in group II was 1.7(95% CI: 1.4-2.1), and for those with middle school or lower education in group II was 2.4 (95% CI: 2.1-2.8). CONCLUSION: Smoking behavior was affected by both individual education attainment and population education level. Smoking cessation measures should be focused on the development of better anti-smoking environment, such as education development, health promotion, etc.

Adult↗

PubMed2002

[Study on nanophase anatase-rutile transition with Raman spectrum].

The nanophase anatase of different size (the average is 40 nm) was synthesized with chemical precipitation method. Transition from nanophase and microphase anatase to rutile were investigated with Raman spectrum. The result indicated that rutile characteristic peak (446 cm-1) appeared after 1 h heat preservation at 900 degrees C for microphase anatase, raising the temperature characteristic peak intensity of rutile (446,610 and 231 cm-1) continued to increase and characteristic peak of anatase (639,515 and 397 cm-1) decreased bit by bit. After 1 h heat preservation at 1,100 degrees C anatase transformed into rutile. While the nanophase anatase transited into rutile entirely after 1 h heat preservation at 900 degrees C, which is about 200 degrees C lower than microphase anatase to rutile transition temperature.

Nanotechnology↗

PubMed2002

Real-time soft tissue modelling for web-based surgical simulation: SurfaceChainMail.

The Web provides a useful environment for simple surgical training simulations. A combination of VRML for 3D rendering, and Java code for the simulation engine, has been used for a range of simple neurosurgical demonstrators. However the elements in these simulators are rigid, to avoid the computational complexity of deformable modelling. In this paper we describe a variation of the ChainMail technique that allows us to provide real-time deformable modelling, even in a Web browser environment on a PC. Our new algorithm, SurfaceChainMail, has been used to develop a simulator for the cutting of two layers of tissue, and separating the layers by pulling them apart.

Algorithms↗

PubMed2002

[Prognostic value of the urokinase-type plasminogen activator and its inhibitors in squamous cell carcinoma of human larynx].

OBJECTIVE: The aim of the present study was to evaluate whether the expression of uPA parameters might be of clinical value in squamous cell carcinoma of human larynx as a tumor/biologically defined risk factor. METHOD: In a consecutive series of 127 patients resected for primary squamous cell carcinoma of human larynx, the expression of uPA and plasminogen activator inhibitors (PAI) type-1, type-2 was determined immunohistochemically. The results were classified as positive and negative. Patients were followed-up prospectively for a median of 41 months(rang 6 to 84 months). Overall survival were analyzed according to Kaplan-Meier and log-rank statistics, the prognostic relevance of uPA, PAI-1, PAI-2 and conventional prognostic factors were analyzed by Cox analyses. RESULT: These revealed a high significant inverse correlation of uPA positive expression survival time(P = 0.006); and patients with PAI-2 positive expression had a significantly longer survival time than those with PAI-2 negative expression(P = 0.009); in different clinicopathological parameters subgroups uPA, PAI-2 added significant survival information, whereas PAI-1 positive expression did not associate with prognoses. Patients with uPA-positive/PAI-2-negative expression had the poorest prognoses. Multivariate analysis revealed that four independent prognostic factors for overall survival time were uPA, PAI-2, lymph node metastasis and differentiation of tumor, P = 0.0002, 0.0001, 0.0117, 0.0436 respectively, relative risk and 95% confidence interval were 1.99 (1.39 to 2.85) 0.36 (0.212 to 0.609), 2.36 (1.21 to 4.61) 1.51 (1.01 to 2.25) respectively. CONCLUSION: We conclude that uPA and PAI-2 are new independent and strong biologically prognostic factors, uPA positive expression may be a powerful aid in evaluating metastatic potential and high risk patients in early stage of human larynx carcinoma.

Adult↗

PubMed2001

AKT/PKB phosphorylation of p21Cip/WAF1 enhances protein stability of p21Cip/WAF1 and promotes cell survival.

p21(Cip1/WAF1) (p21), a p53-inducible protein, is a critical regulator of cell cycle and cell survival. p21 binds to and inhibits both the DNA synthesis regulator proliferating cell nuclear antigen and cyclin A/E-CDK2 complexes. Recently, p21 has also been shown to be a positive regulator of cell cycle progression as p21 is necessary for the assembly and activation of cyclin D1-CDK4/6 complexes. Furthermore, elevated p21 protein levels have been observed in various aggressive tumors as well as linked to chemoresistance. Here we demonstrate that p21 is directly phosphorylated by AKT/PKB, a survival kinase that is hyperactivated in many late stage tumors. Two sites (Thr(145) and Ser(146)) in the carboxyl terminus of p21 are phosphorylated by AKT/PKB in vitro and in vivo. Phosphorylation of Thr(145) inhibits PCNA binding, whereas phosphorylation of Ser(146) significantly increases p21 protein stability. Glioblastoma cell lines with activated AKT/PKB show enhanced p21 stability, and they are more resistant to taxol-mediated toxicity. Finally, AKT/PKB controls the assembly of cyclin D1-CDK4 complexes through modulation of p21 and cyclin D1 levels. These data imply that enhanced levels of p21 in tumors are due, in part, to phosphorylation by activated AKT/PKB. Furthermore, they suggest that one mechanism of AKT/PKB regulation of tumor cell survival and/or proliferation is to stabilize p21 protein.

Amino Acid Sequence↗

PubMed2000

Immunohistochemical study on p53, H-rasp21, c-erbB-2 protein and PCNA expression in HCC tissues of Han and minority ethnic patients.

AIM:To find out the difference of human primary liver carcinogenesis between Han and minority ethnic patients in Xinjiang.METHODS:Expression of p53, c-erbB-2, H-rasp21 protein and proliferating cell nuclear antigen (PCNA) in tumor tissues of 50 patients (Han 38, minority 12) with primary hepatic carcinoma was detected by immunohistochemistry (LSAB).RESULTS:The positive frequency of p53, c-erbB-2, H-rasp21 and PCNA expression was 46.0% (23/50), 70.0% (35/50), 68.0% (34/50) and 82.0% (41/50) in tumor tissues; 4.0% (2/50), 22.0% (11/50), 64.0% (32/50) and 52.0% (26/50) in peritumors respectively and a significant difference, except for H-rasp21, of oncogene alteration was found (P < 0.05) between tumor and non-tumorous tissues. Combined the three oncogenes alteration, 26% (13/50) tumor tissues had positive immunoreactivity, but in peritumor and normal livers it was negative. The positive rate of p53, c-erbB-2 and H-rasp21 protein expression was 39.5% (15/38), 60.5% (23/38) and 39.5% (15/38) in tumors of Han patients; 66.7% (8/12), 100% (12/12) and 75.0% (9/12) in minorities respectively, with statistical difference (P<0.05).CONCLUSION:Overexpression of p53,c-erbB-2 and H-rasp21 in human primary liver carcinoma is an important biomarker of genetic alteration. The different frequency of these oncogenetic changes may reflect some environmental or/and ethnic hereditary factors affecting the liver carcinogenesis. The special life style of Han, Uygur, Kazak and Mongolia nationalities in Xinjiang may also be related to the etiopathogenesis of this disease.

Journal Article↗

PubMed2000

Expression of Human Flt3 Ligand in Pichia pastoris and Its Biological Characteristics.

Flt3 ligand(FL) is a cytokine that stimulates the proliferation and differentiation of hematopoietic stem cells/progenitors. In order to obtain high level of recombinant human soluble FL(rhFL) production, an artificial gene for rhFL was synthesized by using favored genetic codons of the yeast Pichia pastoris. Then the gene was cloned into the vector pPICzalphaA and the resulting construct was introduced into Pichia pastoris for expression. It was found that it was possible to obtain biologically active rhFL with a yield of over 30 mg/L of yeast culture. The rhFL stimulated colony formation from cord blood. rhFL, SCF, GM-CSF and IL-3 are the most promising combination for the in vitro expansion of stem/progenitor cells. It was also showed that rhFL increased the induction of dendritic cells from cord blood in combination with GM-CSF, TNFalpha and IL-4. Interestingly, rhFL stimulated the growth of an endothelial cell line this effect has not been reported before.

Journal Article↗

PubMed1999

Effect of cell fusion on metastatic ability of mouse hepatocarcinoma cell lines.

AIM:To study the effect of cell fusion on metastatic ability of mouse hepatocarcinoma cells and the factors involved in the process of metastasis.METHODS: By the method of successively increasing the concentrations, cell fusion and limit dilution, 8-Ag resistant cells were selected, and HGPRT-Hca-P cells and eight cloned hybridoma cells were obtained. To observe their metastatic ability, they were inoculated into mice foodtaps and the drainage lymph nodes were examined under microscope.RESULTS:The end concentration of 8-Ag which was used to select HGPRT deficient Hca-P cells was 30mg/L.All the cells selected died in HAT culture medium in one week.Fused cells appeared approximately 9 days later. They were round, transparent and a little larger than their parental cells. Eight clones of hybridoma cells were obtained and named as PSH1-PSH8. The metastatic rate of HGPRT-Hca-P cells and PSH7 cells was 28.6% and 71.4% respectively, the difference being significant (P < 0.05). The metastatic rate of other clones was no more than 20% and there was no significant difference from HGPRT-Hca-P cells (P >0.05).CONCLUSION:In normal mice splenic lymphocytes, there are some factors that could inhibit tumor metastasis, however, there are some other factors accelerating tumor cells to metastasize. The establishment of PSH7 provides an experimental model which could be used to study the factors involved in metastasis.

Journal Article↗

PubMedDate not supplied

Expression of testicular germ cell genes identified by differential display analysis.

Using differential display reverse transcriptase-polymerase chain reaction (DDRT-PCR) we identified transcripts encoding for the RNA helicase mDEAH9, Ran binding protein 5 (RanBP5), and 3 novel complementary DNAs designated GC3, GC12, and GC14 in developing testicular germ cells. Sources of RNA for the initial DDRT-PCR screen were purified mouse type A spermatogonia, adult mouse wild-type testis, and W/W(v) mutant mouse testis. We identified cDNA fragments for mDEAH9, RanBP5, GC3, GC12, and GC14 in testis and type A spermatogonia samples from wild-type mice, but not in samples from the W/W(v) mouse testis. These same transcripts were absent in Northern blots of testis RNA from mice treated with busulfan 30 days prior, but were present in testis RNA from wild-type mice at 5, 15, 25, and 40 days of age. The mDEAH9 gene was expressed in many tissues, whereas RanBP5 and GC12 genes were expressed predominantly in the testis with much lower expression in other tissues. The expression of GC3 and GC14 were limited to the testis as evidenced by Northern blot and RT-PCR analyses. The mDEAH9 transcript was not detected in cultured interstitial cells but was found at low levels in cultured immature Sertoli cells, whereas the RanBP5, GC3, GC12, and GC14 transcripts were not detected in either cultured testicular interstitial cells or cultured Sertoli cells. RT-PCR analyses of isolated spermatogonia, pachytene spermatocytes, and round spermatids revealed that mDEAH9, RanBP5, GC3, GC12, and GC14 genes were expressed in all 3 cellular populations. In situ hybridization analyses of testis samples from 40-day-old mice localized expression of mDEAH9, RanBP5, GC3, GC12, and GC14 to the seminiferous tubules. RanBP5 expression appeared to be regulated during the cycle of the seminiferous epithelium, with the highest expression in stages III through VII. Expression of GC14 was greatest in the meiotic germ cell populations.

Animals↗

PubMedDate not supplied

MicroRNAs: Small regulators with a big impact.

MicroRNAs (miRNA) are non-coding small (approximately 22nt) RNAs that regulate diverse physiological and developmental processes. In animals, they regulate target genes by binding imperfectly to 3'UTR sequences in mRNAs and attenuate translation. There are hundreds of miRNA genes in animals, and current studies show they constitute a minimum of 1% of known genes. We are just beginning to understand the diverse roles they play in cellular processes, which include signaling pathways, developmental pathways, and possibly various types of cancers.

Animals↗

PubMedDate not supplied

Transduction of passaged human articular chondrocytes with adenoviral, retroviral, and lentiviral vectors and the effects of enhanced expression of SOX9.

Chondrocytes form and maintain the extracellular matrix of cartilage. The cells can be isolated from cartilage for applications such as tissue engineering, but their expansion in monolayer culture causes a progressive loss of chondrogenic phenotype. In this work, we have investigated the isolation of human articular chondrocytes from osteoarthritic (OA) cartilage at joint replacement, their expansion in monolayer culture, and their transduction with adenoviral, retroviral, and lentiviral vectors, using the gene encoding green fluorescent protein as a marker gene. The addition of growth factors (transforming growth factor beta(1), fibroblast growth factor 2, and platelet-derived growth factor BB) during cell culture was found to greatly increase cell proliferation and thereby to selectively enhance the efficiency of transduction with retrovirus. With adenoviral and lentiviral vectors the transduction efficiency achieved was 95 and 85%, respectively. Using growth factor-supplemented medium with a retroviral vector, efficiency in excess of 80% was achieved. The expression was stable for several months with both retrovirus and lentivirus when analyzed by fluorescence-activated cell-sorting flow analysis and immunoblotting. Transduction with SOX9 was investigated as a method to reinitiate cartilage matrix gene expression in passaged human OA chondrocytes. Endogenous collagen II expression (both mRNA and protein) was increased in monolayer culture using both adenoviral and retroviral vectors. Furthermore, collagen II gene expression in chondrocytes retrovirally transduced with SOX9 was stimulated by alginate bead culture, whereas in control chondrocytes it was not. These results demonstrated methods for rapid expansion and highly efficient transduction of human OA chondrocytes and the potential for the recovery of key features of chondrocyte phenotype by transduction with SOX9.

Adenoviridae↗

PubMedDate not supplied

Comparative cytotoxicity of high-osmolar and low-osmolar contrast media on HKCs in vitro.

BACKGROUND: Radiocontrast-induced nephropathy is a clinically important complication of intravascularly applied radiocontrast media. A predominant toxic effect of contrast media on renal tubules has been shown in previous clinical trials and animal experiments. Bax and Bcl-2 are members of the Bcl-2 family. Caspases are a family of cell death proteases, caspase-3 is one of the key executioners of apoptosis. In this study, we evaluated the cytotoxicity of high-osmolar contrast media (HOCM; diatrizoate) and low-osmolar contrast media (LOCM; iohexol) on human renal tubular epithelial cells (HKCs), and determined the regulatory roles of Bax/Bcl-2 and caspase-3 on apoptosis induced by contrast media (CM) in HKCs. METHODS: An HKC line was used. Experiments were divided into 7 groups: the HOCM group with iodine 111 mg/mL, HOCM group with iodine 74 mg/mL, LOCM group with iodine 111 mg/mL, LOCM group with iodine 74 mg/mL, mannitol high-osmolar control group, mannitol low-osmolar control group and a culture media control group . The cytotoxicity of HOCM and LOCM were evaluated by cell proliferation and viability assay (MTT assay) and lactate dehydrogenase (LDH) release. Apoptosis were assessed by Hochest 33258 fluorescence-stained cytospins, TUNEL staining, DNA agarose gel electrophoresis, electron microscope and flow cytometric DNA analysis. The protein ex-pression of Bax/Bcl-2 was determined by Western blot analysis, and caspase-3 activity was also determined by the fluo-rometric method. RESULTS: Compared with the control group, LDH levels increased significantly (p<0.05) and cell viability decreased in cells treated with HOCM or LOCM (p<0.05) in an osmotic pressure-, iodinated ion- and time-dependent manner; in the HOCM groups, diatrizoate induced cultured HKC apoptosis. In the LOCM groups, iohexol did not induce apoptosis. Compared with equal osmotic pressure mannitol, apoptosis increased in HKCs incubated with diatrizoate (p<0.05). Bax/Bcl-2 production and caspase-3 activity were up-regulated in cultured HKCs treated with HOCM iodine 74 or 111 mg/mL meglumine diatrizoate. CONCLUSIONS: Both HOCM and LOCM had toxic effects on HKCs, HOCM was more cytotoxic than LOCM; HOCM induced cultured HKC apoptosis while LOCM did not induce cultured HKC apoptosis in the indicated concentrations. The regulation of apoptosis induced by HOCM in HKCs may be regulated by Bax/Bcl-2 and caspase-3.

Apoptosis↗