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Ying Hu

Publications and source records attributed to Ying Hu.

106 records · Page 6Linked to original sources
PubMed2003

Isolation and identification of mesenchymal stem cells from human fetal pancreas.

Mesenchymal stem cells (MSCs) have been cultured from many sources, including bone marrow and liver. To further support our hypothesis that MSCs exist in most postnatal tissues, we isolated a clonogenic, multipotent, rapidly proliferating population of cells from a fetal pancreas and termed them "pancreas-derived mesenchymal stem cells" (PMSCs). They withstood being passaged as many as 30 times without sustaining significant structural changes. In this study, we showed that PMSCs are positive for CD44, CD29, and CDI3 but negative for CD34 and HLA-DR and that they stained with collagen I and III but not with von Willebrand factor antibody. During the log phase of growth, PMSCs proliferated, doubling in population in about 30 hours. Cell-cycle analysis showed that more than 90% of cells were in the G0 and G1 phases, whereas a small subpopulation of cells were actively engaged in proliferation (S + G2 + M = 3.55%). Under differentiation culture conditions, PMSCs differentiated into cells of osteogenic, chondrogenic, and adipogenic lineages. These results demonstrate that PMSCs can be isolated from human fetal pancreas by means of their adherent ability and that they are capable of self-renewal, propagation, and multipotent differentiation.

Base Sequence↗
PubMed2003

Genetic susceptibility and dietary patterns in lung cancer.

Cigarette smoking is the dominant risk factor for lung cancer, but only a minority of smokers ever develops tumors. Though genetic susceptibility is likely to explain some of the variability in risk, results from previous studies of genetic polymorphisms have been inconclusive. As diet may also affect the risk of lung cancer, it is possible that the degree of risk produced by smoking and genetic susceptibility varies, depending on diet. To assess this hypothesis, we conducted a case-control study to examine the effect of cigarette smoking, dietary patterns and variation in genes involved in phase II metabolism. A total of 254 individuals with lung cancer and 184 healthy controls were recruited for the study. To identify persons with similar dietary patterns, cluster analysis was performed using nutrient densities of four major dietary constituents: protein, carbohydrate, animal fat, and dietary fiber. Two groups of individuals were identified with distinct dietary patterns: (1) a group (n=241) with a high intake of animal fat and protein and a low intake of carbohydrates and dietary fiber (the 'unhealthy' pattern) and (2) a group (n=197) with a high intake of fiber and carbohydrate and a low intake of protein and animal fat (the 'healthy' pattern) [corrected]. On stratified analysis, several genotype/dietary pattern combinations were found to affect risk of lung cancer. Smokers who were not homozygous for the most common GSTP1 allele and had a healthy dietary pattern were at significantly lower risk than smokers who were homozygous for the GSTP1 common allele and who had an unhealthy dietary pattern (OR=0.16, 95%CI: 0.04-0.57). Among smokers who were GSTM1 null, persons with a healthy dietary pattern were at lower risk than persons with an unhealthy dietary pattern (OR: 0.46, 95%CI: 0.21-1.01). Among smokers with an unhealthy dietary patterns, persons with a His/His genotype in the exon 3 polymorphism of EPHX1 were at significantly lower risk that persons who were not homozygous. These data suggest that dietary factors may affect the risk imposed by genetic susceptibility at detoxification loci. Adjustments using dietary pattern may be useful in elucidating the effects of polymorphisms in genes responsible for carcinogen metabolism.

Adult↗
PubMed2003

Allelic variation in gene expression is common in the human genome.

Variations in gene sequence and expression underlie much of human variability. Despite the known biological roles of differential allelic gene expression resulting from X-chromosome inactivation and genomic imprinting, a large-scale analysis of allelic gene expression in human is lacking. We examined allele-specific gene expression of 1063 transcribed single-nucleotide polymorphisms (SNPs) by using Affymetrix HuSNP oligo arrays. Among the 602 genes that were heterozygous and expressed in kidney or liver tissues from seven individuals, 326 (54%) showed preferential expression of one allele in at least one individual, and 170 of those showed greater than fourfold difference between the two alleles. The allelic variation has been confirmed by real-time quantitative PCR experiments. Some of these 170 genes are known to be imprinted, such as SNRPN, IPW, HTR2A, and PEG3. Most of the differentially expressed genes are not in known imprinting domains but instead are distributed throughout the genome. Our studies demonstrate that variation of gene expression between alleles is common, and this variation may contribute to human variability.

Alleles↗
PubMed2003

Direct modulation of rod photoreceptor responsiveness through a Mel(1c) melatonin receptor in transgenic Xenopus laevis retina.

PURPOSE: Retinal circadian signals may have a role in maintaining the normal function and health of photoreceptors. Melatonin is an output of the retinal circadian oscillator and provides nocturnal signaling that is mediated through specific G-protein-coupled receptors. Melatonin receptors are expressed in retinal photoreceptor cells, and this study was undertaken to test the hypothesis that melatonin directly increases photoreceptor responses through melatonin receptors. METHODS: Transgenic Xenopus laevis frogs were generated using a DNA construct containing a Xenopus opsin promoter driving expression of a melatonin Mel(1c) receptor-green fluorescent protein (GFP) fusion protein (XOP-MEL(1c)-GFP). Electroretinogram (ERG) analysis on transgenic and normal tadpole eyes was performed in response to melatonin treatment, and the eyes were subsequently examined by confocal microscopy and GFP immunocytochemistry. RESULTS: XOP-MEL(1c)-GFP transgenic frogs demonstrated GFP immunoreactivity in rod photoreceptor inner segments throughout the retina, indicating the rod-specific expression of the Mel(1c)-GFP fusion protein. ERG analysis of transgenic tadpole eyes showed that 1 to 100 nM melatonin increased the a- and b-wave amplitudes. Control transgenic (XOP-GFP) and normal frogs exhibited only modest ERG responses to 100-nM melatonin treatment. The effect of melatonin on a- and b-wave amplitudes in XOP-MEL(1c)-GFP transgenic frogs was dose dependent, with ERG responses occurring at physiological concentrations. CONCLUSIONS: The results suggest that melatonin, acting through Mel(1c) receptors on rod photoreceptor membranes, directly stimulates the responsiveness of rod photoreceptors to light. This supports the hypothesis that melatonin acts both as an intracrine and paracrine circadian signal of darkness, and binds to specific receptors in photoreceptors and other retinal cells to increase visual sensitivity.

Animals↗
PubMed2003

[Study of biological characteristics of murine dermal mesenchymal stem cells and their enhancement of hematopoiesis recovery].

OBJECTIVE: To study the characteristics of dermal mesenchymal stem cells (DMSC), and explore whether they could enhance hematopoiesis recovery in vivo as well as facilitate proliferation and differentiation of hematopoietic cells in vitro. METHODS: Multipotential stem cells from the murine dermal mesenchyme were dissociated and cultured as donor cells. After 2 approximately 3 passages, the growth status, cell cycle, immunophenotype and morphology of DMSC were analyzed. Hematopoietic cells were plated onto a feeder layer formed by DMSC, cell count and CFU-GM yields were observed dynamically. Female mice received 5 Gy (137)Cs radiation were injected with DMSC cultured for 2 - 3 passages via tail vein. Cell count and CFU-GM yields of the bone marrow were observed regularly. Pathological study of the liver, spleen and bone marrow was done to evaluate hematopoiesis recovery. RESULTS: Murine DMSC are adherent cells with a morphology of fibroblastoid and spindle and multiangle in shape. Immunophenotypes showed that CD(45), CD(34), HL-DR positive DMSC were 1 - 3%, CD(44) and CD(13) positive DMSC 75 approximately 95%. Cell cycle assay demonstrated 83% of DMSC being G(0)/G(1) phase. In vitro, the total cell count and CFU-GM yields in the experimental group were higher than those of the long-term culture bone marrow cells by the third week. The DMSC can sufficiently support the proliferation and differentiation of hematopoietic cells for seven weeks. In vivo, peripheral granulocytic count, cells in the bone marrow of one femoral bone and CFU-GM by the third week in the experimental group were much higher than those of controls. Genetic assay of the murine blood demonstrated Y chromosome. CONCLUSION: The DMSC have characteristics of stem cells. DMSC sped up hematopoiesis recovery of irradiated mice. DMSC as a feeder layer can support proliferation and differentiation of hematopoietic cells.

Animals↗
PubMed2003

[Using ultrasonically activated scalpels as major instrument for vessel dividing and bleeding control in minimally invasive video-assisted thyroidectomy].

OBJECTIVE: To establish new techniques on the control of vessel dividing and bleeding in minimally invasive video-assisted thyroid surgeries. METHODS: One hundred and seventy volunteer patients with nodular goiter, adenoma and Graves' disease consecutively received the endoscopic thyroid operation according to Miccoli's mode from April 2002 to June 2003. The approach was designed to use ultrasonically activated scalpels [Harmonic Scalpel (R), Johnson & Johnson, USA] as a major, suction-dissector or others as supplementary instruments during the whole process. During the operations, two methods, "sequenced dissect-coagulate-cut" and "pre-coagulation + interlaced cut-suck-coagulate-dissect", were employed and separately evaluated for their safety or efficacy. RESULTS: All of the procedures, except that 2 (their lesions were proven to be "cancer" by frozen section and need different treatment), were successfully completed. None of them were interrupted and converted to open surgery due to uncontrolled bleeding or severe postoperative hematoma. Branches of major thyroid vessels can be directly divided by ultrasonic scalpel without ligation or using hemoclips, supposing the technique of "sequenced dissect-coagulate-cut" method was strictly used. Bleeding during intra-gland dissection can be effectively controlled by the combined techniques of precoagulation of the vessels and the capsule vessel network near and around the incision, and then, by coordinating manipulation with a special multiple functional ultrasonic scalpel and a suction-dissector, supposing the technique of "interlaced cut-suck-coagulate-dissect" was properly employed. CONCLUSIONS: Using ultrasonic scalpels as major, suction-dissector or others as supplementary instruments, manipulating cooperatively during the whole process, can be an ideal fashion in the site of a narrow gasless working space via a small single incision in anterio-inferior neck. And this may dramatically simplify the manipulation, and hence greatly reduce the operative difficulty. The reforms resolved two key technique problems in Miccoli's endoscopic operation: vessel-dividing and bleeding-control, therefore, laying a sound basis for the clinical application of this special approach.

Adolescent↗
PubMed2002

S-propyl cysteine reduces the secretion of apolipoprotein B100 and triacylglycerol by HepG2 cells.

A number of sulfur-containing amino acids and peptides are found in allium plants such as onion and garlic that have physiologic functions. In HepG2 cells, S-propyl cysteine decreased the secretion of apolipoprotein B100. The compound reduced the secretion of newly synthesized triacylglycerol and cholesterols from radiolabeled acetate. We associated the decrease of apolipoprotein B100 secretion to the length of the acyl-chain of the sulfur-containing amino acids. The present study suggests that foods containing S-propyl cysteine including onions have beneficial effects.

Allium↗
PubMed2002

[Imbalance of Th1/Th2 cytokines in patients with pulmonary tuberculosis].

OBJECTIVE: To explore if there is an imbalance of Th1/Th2 cytokines in patients with pulmonary tuberculosis and its correlation with disease severity and treatment results. METHODS: The levels of serum IgE, IL-4 and IFN-gamma were measured in 100 healthy controls and 124 patients with pulmonary tuberculosis who were sputum positive for Mycobacterium tuberculosis before treatment. The cytokine levels were compared and their correlation with disease severity, sputum conversion after treatment, and treatment protocols were analyzed. RESULTS: The serum levels of IgE, IL-4 and IFN-gamma were 1.048 +/- 0.496, 0.439 +/- 0.160 and 0.213 +/- 0.017 respectively in pulmonary tuberculosis, and 0.867 +/- 0.289, 0.421 +/- 0.024 and 0.224 +/- 0.005 respectively in the controls. The serum level of IL-4 was higher in patients with severe disease than that in patients with milder disease. Both IL-4 and IFN-gamma were significantly higher in cases receiving a second course of therapy than in patients receiving initial therapy. In patients who were sputum positive for Mycobacterium tuberculosis after two months of therapy, the serum level of IL-4 was higher but that of IFN-gamma was lower compared to those who became sputum negative for Mycobacterium tuberculosis after two months' treatment. CONCLUSIONS: Patients with active pulmonary tuberculosis before antituberculous therapy showed lower expression of Th1 and higher expression of Th2 cytokines, and this cytokine profile was correlated with disease severity. Patients with lower serum IFN-gamma and higher IL-4 before treatment were less responsive to antituberculous therapy.

Adult↗
PubMed2002

[Exclusive identification of gene loci of autosomal dominant nonsyndromic hearing loss].

OBJECTIVE: The purpose is to map related genes of an autosomal dominant nonsyndromic hearing loss kindred. METHOD: Linkage analysis was carried out using screening markers of the 22 reported loci. RESULT: Linkage analysis showed no linkages between pedigree gene and reported loci. CONCLUSION: The autosomal dominant nonsyndromic hearing loss in the kindred may be resulted from a new gene.

Chromosome Mapping↗
PubMed2002

[Comparative study of human fetal and adult bone marrow derived mesenchymal stem cells].

OBJECTIVE: To explore the differences of phenotype and biological characteristics between fetal and adult bone marrow derived mesenchymal stem cells. METHODS: Mononuclear cells from 4-5 months old human aborted fetus and normal adult bone marrow were cultured in SF medium to obtain mesenchymal stem cells. The growth curve, cell cycle, immunophenotype, in vitro expansion potential, differentiation capacities were investigated. RESULTS: The adherent fetal and adult bone marrow-derived cells cultured in the absence of differentiation stimuli gave rise to a population of cells with phenotypical features of mesenchymal stem cells (MSC). These MSCs were similar in cell morphology and antigenic phenotype. The proliferative and multilineage differentiation potential of the bone marrow derived MSC from the fetus is higher than that from the adult, but the adherent ability of the MSCs from the adult is higher than that from the fetus. CONCLUSION: Fetal bone marrow derived MSCs should be enough to sustain a steady supply of low differentiated cells for proliferation, hence an abundant and accessible cellular reservoir for stem cell bioengineering, whereas adult bone marrow derived MSCs are more useful in hematopoietic reconstitution in bone marrow transplantation.

Adult↗
PubMed2002

[Effects of anti-ABL tyrosine kinase intrabody on the growth of K562 cells in nude mice].

OBJECTIVE: To study the effects of anti-ABL tyrosine kinase intrabody on the growth of human chronic myelogenous leukemia (CML) cells in nude mice. METHODS: A recombinant retroviral vector MSCV-ibE-IRES-eGFP was constructed to express intracellular single-chain antibody (intrabody) against ABL tyrosine kinase domain in CML cells. K562 cells were transduced with the retrovirus, eGFP+ cells were then selected by fluorescence-activated cell sorting (FACS). The intrabody mRNA expression was determined by reverse transcription (RT)-polymerase chain reaction (PCR). BCR/ABL and c-ABL protein tyrosine kinase (PTK) activity in the cells was examined. Transduced cells and control group K562 cells were transplanted into nude mice respectively and the tumor sizes were dynamically observed. RESULTS: K562-ibE cell was obtained. Expression of the BCR/ABL and c-ABL protein tyrosine kinase activity of harvested K562-ibE cells were markedly inhibited. At 14, 21 and 28 days after cell injection, the tumor volumes of experimental mice were obviously smaller than that of control mice, about one half of the control groups (P < 0.05). CONCLUSION: The growth of K562-ibE cells was significantly inhibited in vivo. It is possible that inhibition of the BCR/ABL protein tyrosine kinase activity by the intrabody blocked BCR/ABL signal transduction pathway, promoted apoptosis and reduced tumorigenicity of K562 cells in vivo.

Animals↗
PubMed2002

[Transplantation of mesenchymal derived stem cells followed by G-CSF injection can reconstitute hematopoiesis of lethally irradiated BALB/c mice].

OBJECTIVE: To explore the hematopoietic reconstitution potential of mesenchymal derived stem like cells. METHODS: We transplanted bone marrow mesenchymal derived stem like cells into lethally irradiated BALB/c mice. Hematopoietic cells were derived from the non-adherent bone marrow cells 24 hours after initial culture while murine mesenchymal derived stem like cells from bone marrow of donor mice were cultured for 10 days before the transplantation. RESULTS: All mice of group 1 and 3 died in 7-8 days post irradiation following transplantation, while all the mice from group 2 and 4 survived. The time course of hematopoietic reconstitution was then observed. The peripheral blood and bone marrow cell count recovered in the MSC + G-CSF transplanted group and the BM transplanted group after 3 weeks. Interestingly, CFU-GM number in the MSC + G-CSF transplanted group increased significantly after 2 weeks and even more than that in the BM transplanted group after 3 weeks while as CFU-GM colony dropped 2 weeks after in the BM transplanted group. Spleen colony (CFU-S) number and size of the MSC + G-CSF transplanted group was significantly greater than the BM transplanted group. Furthermore, PCR analysis was performed using peripheral blood cells to determine if any male-derived cells were present. No male-derived cells were found in any of the mice from group 1 and 3. Y-chromosome-specific src gene was found to be dominant in the MSC + G-CSF transplanted group and the BM transplanted group by week 4 post transplantation. In addition, we demonstrated that induction with G-CSF lead to CFU-GM colony formation from MSC compartment in vitro. CONCLUSION: These results indicate that under stimulation of G-CSF, mesenchymal derived stem like cells might differentiate into hematopoietic primitive stem cells in vivo and have the capacity to re-establish hematopoiesis in lethally irradiated mice. This study should provide an alternative transplantation treatment for malignancy.

Animals↗
PubMed2002

[Identification and isolation of mesenchymal stem cells from human fetal pancreas].

OBJECTIVE: To isolate and identify the phenotype and biological characteristics of pancreas derived mesenchymal stem cell. METHODS: Fresh pancreas of 4-5 months old aborted fetus was dissected free from connective tissue, and was cut into small pieces. The adherent cells were harvested and subcultured, after the third subculture, the cells were used for examination. Cell cycle was analyzed by measuring DNA content by FACScan flow cytometer. Phenotype of MSCs was analyzed by immunohistochemical SA technique and differentiated cells were identified by relevant specific staining. RESULTS: Fetal pancreas derived cells gave rise to a population of adherent cells characterized by the presence of a predominant cell type with a typical fibroblast like morphology. By transmission electron microcopy, MSC had few endoplasmic reticulums and mitochondrias. During the log phase of growth, MSC proliferated with a two fold population at 30 h. MSC can be ex vivo expanded by successive cycles of trypsinization, seeding, and culture. Under these conditions, MSC had capability of passaging up to 30 times without displaying significant changes in morphology, with 2-fold increase in cell number after each passage. This indicates the high ex vivo expansion potential of MSC. The results showed that the yield of CFU-Fs was above 200 clones even after the 6th passage. Cell cycle analysis by flow cytometry revealed that more than 83% of cells were in the G0/G1 phases, while a small population of cells were actively engaged in proliferation (S + G2 + M = 17%). We also showed that more than 86% of cells were positive stained by FITC labeled CD44, CD29, CD13, and only about 1% of cells were positive for CD34, HLA-DR. Expression of collagen I, III was positive while vWF was negative. In the differentiation study, we found culture-expanded pancreas MSCs could be directed into the osteogenic lineage as detected by osteoblastic morphology, expression of alkaline phosphatase, modulation of osteocalcin mRNA production and the formation of a mineralized extracellular matrix. We also found that MSCs could give rise to the adipogenic and chondrogenic lineage as evidenced by accumulation of lipid-rich vacuoles within cells and the expression of lipoprotein lipase mRNA or the expression of collagen II and the deposition of proteoglycans. CONCLUSION: Mesenchymal stem cells existing in human pancreas can be isolated by their adherent ability and should be essential to sustain a steady supply of primitive cells in tissue remodeling.

Cell Differentiation↗
PubMed2002

[Raman spectroscopic and electrochemical studies of C60 derivatives modified solid supported bilayer lipid membrane (s-BLM)].

The detection sensitivity of C60 modified-s-BLMs and C60 derivatives modified-s-BLMs to I- was compared by electrochemical and Raman spectroscopic techniques. The results implied that some of C60 derivatives could increase the detection sensitivity of s-BLMs to I-. This showed that C60 derivatives has the great application prospect in BLMs-based molecular device.

Biosensing Techniques↗
PubMed2001

[Phenotypical and Biological Characteristics of Human Fetal Marrow and Liver Mesenchymal Stem Cells]

There has been an increasing interest in recent years in the stromal cell system. The stroma is a complex tissue, composed of a number vascular and connective tissue cell types including endothelial cells, adipocytes, smooth muscle cells, osteogenic cells, and stromal cells. The marrow mesenchymal stem cells are capable of self-renewal and differentiate into various connective tissue lineages including bone, cartilage, tendon, muscle, fat, and marrow stroma. Recently, techniques for the isolation of adult bone marrow-derived human and animal mesenchymal stem cells have been described, as well as the methods to directing their differentiation into osteogenic, chondrogenic, tendogenic, myogenic, adipogenic, and marrow stromal lineages. But there is no report about the fetal bone marrow- and liver-derived mesenchymal stem cells. Are they the same or not? In our assay, human fetal mesenchymal stem cells from 4 - 5 months old human fetal bone marrow and liver low-density mononuclear cells were cultured, and the cell cycle, immunophenotype and ex vivo expansion properties were studied. Results showed that the mesenchymal stem cells from fetal liver and fetal bone marrow were similar in morphology, growth character and immuno-phenotypes, but the liver mesenchymal cells manifested higher ability to support hematopoiesis than the marrow-derived mesenchymal cells. This study demonstrates that adherent fetal marrow- and liver-derived cells cultured in the absence of differentiation stimulus gave rise to a population of cells with phenotypical features of mesenchymal stem cells, and should be enough to sustain a steady supply of low differentiated cells upon proliferation.

Journal Article↗