Biomedical subjects

Yan Mei

Publications and source records attributed to Yan Mei.

15 recordsLinked to original sources

PubMed2006

[Isolation and purification of BMScs of GFP transgenic mouse using the method of adhering to cuture plastic in different time].

OBJECTIVE: To adopt the method of adhering to culture plastic in different time for cultivating and purifying BMSCs of green fluorescent protein (GFP) transgenic mice. METHODS: Bone marrow cells isolated from GFP transgenic mice are directly planted in culture flask and an exchange of the total volume medium is made at different time. Then the cells adhering to culture plastic are differently counted according to the cell types and are examined by immunohistochemistry using the antibodies of CD44, CD45 and CD54 in three days. Moreover, the cells after the exchange of the total volume medium in 4 hours, 8 hours and 24 hours are selected and successively subcultured down to the fifth passage. Then the result of amplification is calculated and the cells are examined by immunohistochemistry using the antibodies of CD44, CD45 and CD54. RESULTS: With the extending of the time for the first exchange of medium, the density of cells adhering to culture plastic increased accordingly, but the BMSCs proportion decreased. The cells after first exchange of medium in 4 hours had high BMSCs proportion but low BMSCs density, and the cells in 24 hours had high BMSCs density and low BMSCs proportion. However, the cells in 8-10 hours had high BMSCs density and also high BMSCs proportion. The subcultured BMSCs could stably express GFP. CONCLUSION: The method of adhering to culture plastic in different time for cultivating and purifying BMSCs of GFP transgenic mice is effective. It is suitable to make the first exchange of total volume medium in 8-10 hours. The subcultured cell has the capacity for amplification and will probably be a seed cell for the research of tissue engineering and gene therapy.

Animals↗

PubMed2006

Islet formation and regeneration.

OBJECTIVE: To explore the mechanisms of differentiation and development of pancreatic endocrine cells as well as pancreatic regeneration. METHODS: Human embryonic pancreatic tissue at 7-14 weeks of gestation was collected. Diabetes mellitus rat model was induced with 65 mg/kg of streptozotocin. Insulin, glucagon, somatostatin, nestin, and cytokeratin 19 (CK19) of pancreatic tissues were observed by immunohistochemistry. RESULTS: At 9 weeks of gestation, pancreatic epithelial cells began to co-express insulin, glucagon, somatostatin, and CK19 before migration. Islet cells gradually congregated along with the increase of aging, and at 14 weeks of gestation histological examination showed islet formation. At 12 weeks of gestation, nestin-positive cells could be seen in the pancreatic mesenchyme. During early embryogenesis, islet cells of pancreatic ducts co-expressed insulin, glucagon, and somatostatin. During pancreatic regeneration after damage, nestin expression of islet cells increased. CONCLUSION: In the early stage of embryogenesis, islet cells of primary pancreatic ducts can be differentiated to multipotential endocrine cells before migration. During tissue regeneration, pancreatic stem cells may differentiate and proliferate to form pancreatic islet.

Animals↗

PubMed2006

[Analysis on the long-term curative effect of endoscopic sinus surgery].

OBJECTIVE: To analyze the long-term curative effect of endoscopic sinus surgery. METHOD: One hundred and twenty-eight cases (180 sides) of chronic sinusitis and nasal polyps were treated with FESS, 80 side (64 cases) were elected randomly to deal with the anatomical variation of middle and inferior turbinate and nasal septum during the operation (rectification group), comparing the curative effects with other 100 sides (64 cases) (contrast group). RESULT: Following up survey from 12 months to 24 months postoperatively, the curative effect in the rectification group was better than that in the contrast group. CONCLUSION: Dealing with anatomical variation that influence the nasal cavity function in FESS can significantly improve the healing rate of sinusitis and ventilation function and decrease the adhesions rate.

Adolescent↗

PubMed2006

[Analysis of differential expression genes related to different metastasis potential of adenoid cystic carcinoma using restriction fragments differential display PCR].

OBJECTIVE: To construct differential expression profiles of adenoid cystic carcinoma cell lines for screening candidate genes related to metastasis and to verify some candidate genes in adenoid cystic carcinoma. METHODS: Restriction fragments differential display PCR (RFDD-PCR) was used to set up gene expression profiles of adenoid cystic carcinoma cell lines-ACC-M and ACC-2, with high and low metastasis potential respectively. Candidate genes were screened through bioinformatics analysis. Then, a gene family of these candidate genes was checked using semi-quantitative reverse transcription-PCR(RT-PCR). RESULTS: Two gene expression profiles including 5420 gene fragments were constructed, 12 genes of a family called matrix metalloproteinase genes (MMPs) were observed obvious differentially expressed between two cell lines. Results of semi-quantitative RT-PCR also identified this different expression of MMP2,MMP7,MMP9,MMP14,MMP15 and MMP24. CONCLUSION: The construction of gene expression profiles of ACC-M and ACC-2 cell lines makes the foundation for seeking the target genes of adenoid cystic carcinoma. MMP2,MMP7,MMP9 and MMP15 may be relevant with carcinogenesis, development and metastasis of adenoid cystic carcinoma, and different metastasis potential may result from different subtype of MMPs gene family.

Carcinoma, Adenoid Cystic↗

PubMed2005

[Changes in the expression of vital cytokines for pancreatic development in early embryo].

OBJECTIVE: To clarify the changes in the expression of vital cytokines for pancreatic development in early embryo and hence provide preclinical data regarding embryonic pancreas transplanted for treatment, of diabetes mellitus. METHODS: Sample collection was conducted in accordance to the principle of informed consent. Histochemical S-ABC method was adopted in studying pancreas at 7-12 weeks of gestation, and analysis was made on vital cytokines expression as well as the differentiation and forming of pancreatic islets. RESULTS: It was found that the expression of Insulin, Glucagon, Somatostatin and Cytokeratin begins at 7 weeks, and the change is consistent with the differentiation and formation of pancreatic islets. IGF-I and F-VIII appear at 12 weeks. CONCLUSION: Insulin, Glucagon, Somatostatin, Cytokeratin, IGF-I and F-VIII play a regulatory role in the development of embryonic pancreas and are related to the differentiation and formation of endocrine and exocrine glands of pancreas. The pancreas after 12 weeks of gestation can be used as a donated graft for pancreas transplantation.

Female↗

PubMed2005

Application of restriction fragment differential display-polymerase chain reaction in study on differential expression profiles of human diseases.

OBJECTIVE: To establish the restriction fragment differential display-polymerase chain reaction (RFDD-PCR) as an efficient technique for constructing and studying the gene expression profile of human tissues. METHODS: The tissues of mamma adenocarcinoma (T), cancerometastasis lymph node (L) and normal mammary (N) from one mammary infiltrating ductal carcinoma case were collected, and the gene expression profile of each kind of tissue was constructed using RFDD-PCR technique at equal pace according to the operating manual of Qbio-gene Company. Then all fragments of the three gene expression profiles were separated and displayed by electrophoresis. With the use of gene database at the website http://www.Qbio-gene.com/display, the authors identified the names of the probable fragments by bioinformatics analysis. Through comparison of the three profiles, the numbers and types of most differentially expressed gene fragments were displayed. RESULTS: The expression profiles of the three kinds of tissue have been constructed covering 1716 fragments of mammary adenocarcinoma, 1769 of cancerometastasis lymph nodes and 1922 of normal mammary tissue. Among these 5407 fragments, 39.39% were exactly the same. While 33.9% sequences of T and L showed differences in abundance or presence, 40.9% of T and N and 39.6% fragments of L and N were observed differentially expressed. These differentially expressed gene fragments were found to relate with metastasis, differentiation, inflammation and so on. CONCLUSION: RFDD-PCR is an efficient technique for research in human diseases genomics as a mass screening for complete gene expression profile with high-flux. Through comparison among three or more profiles, the screening for candidate genes of a certain disease can be accomplished, and there is probably a chance to identify novel gene or expressed sequence tag.

Adenocarcinoma↗

PubMed2005

[Expression of HNF4alpha and HNF6 mRNA during the process of mouse liver development].

OBJECTIVE: To investigate the function of HNF4a and HNF6 during liver development. METHODS: The expression levels of HNF4alpha and HNF6 at E8, 9, 13, 15, 17, P1 and in adult mouse liver were detected by RT-PCR and in situ hybridization. RESULTS: RT-PCR results showed that HNF4alpha first expressed at E9, the time of liver bud formation, and lasted through all gestation and existed in adult liver. In situ hybridization showed that the expression of HNF4alpha was detected at the cells of liver cords during various stages of mouse liver development, and there were still a few HNF4alpha positive hepatocytes in adult liver. The cells of bile duct plate and biliary epithelial cells, endothelial cells, hematopoietic cells of liver were negative for HNF4alpha. The expression of HNF6 mRNA was detected in the liver at E9, the time of liver formation onset. Then, HNF6 mRNA disappeared transiently at E13, but it appeared again at E15. Its expression lasted until adult. In situ hybridization studies showed that most liver cord cells were positive for HNF6 at E9 and E15. At E17 and P1, the expression levels of liver cord cells declined, and HNF6 strongly expressed in the cells of bile duct plate and biliary epithelial cells. CONCLUSION: HNF4alpha could modulate the formation of liver bud, trigger the differentiation of hepatic stem cell towards hepatocytes, and keep the shape of hepatocytes. HNF6 might play a role at the onset of liver development, in the differentiation of hepatic stem cell towards biliary epithelial cells, and in maintaining the morphological characteristic of biliary epithelial cells.

Animals↗

PubMed2005

[Preliminary analysis of retinal gene expression profile of diabetic rat].

OBJECTIVE: Establishing the retinal gene expression profiles of non-diabetic rat and diabetic rat and comparing the profiles in order to analyze the possible genes related with diabetic retinopathy. METHODS: The whole retinal transcriptional fragments of non-diabetic rat and 8-week diabetic rat were obtained by restriction fragments differential display-PCR (RFDD-PCR). Bioinformatic analysis of retinal gene expression was performed using soft wares, including Fragment Analysis. After comparison of the expression profiles, the related gene fragments of diabetic retinopathy were initially selected as the target gene of further approach. RESULTS: A total of 3639 significant fragments were obtained. By means of more than 3-fold contrast of fluorescent intensity as the differential expression standard, the authors got 840 differential fragments, accounting for 23.08% of the expressed numbers and including 5 visual related genes, 13 excitatory neruotransmitter genes and 3 inhibitory neurotransmitter genes. At the 8th week, the expression of Rhodopsin kinase, beta-arrestin, Phosducinìrod photoreceptor cGMP-gated channel and Rpe65 as well as iGlu R1-4 were down-regulated. mGluRs and GABA-Rs were all up-regulated, whereas the expression of GlyR was unchanged. CONCLUSION: These results prompt again that the changes in retinal nervous layer of rat have occurred at an early stage of diabetes. The genes expression pattern of visual related genes and excitatory and inhibitory neurotransmitters in rat diabetic retina have been involved in neuro-dysfunctions of diabetic retina.

Animals↗

PubMed2005

[Expression of Nestin, CK19, insulin, glucagon and somatostatin in embryonic pancreas].

AIM: To investigate the expression of Nestin, CK19, insulin, glucagon and somatostatin in the development of embryonic pancreas. METHOD: Sample collection was conducted in accordance to the principle of informed consent. Immunohistochemical SABC method and LAB-SA for double satining were used to study the expression of the molecules in human embryonic pancreas. RESULTS: (1) There are few nestin-positive cells in the stroma of the embryonic pancreas. CK19 is consistently expressed in the epithelial cells of pancreatic ducts. (2) From 7 weeks of gestation, pancreatic duct epithelial cells begin to differentiate into insulin, glucagon and somatostatin-positive cells. CONCLUSION: Nestin-positive pancrease stem cells are in the stroma of human embryonic pancrease. Pancreatic duct epithelial cells differentiate into islet cells secreting insulin at the early stage of embryonic development.

Animals↗

PubMed2004

Improved procedure for the oxidative cleavage of olefins by OsO4-NaIO4.

[reaction: see text] Oxidative cleavage of olefins by OsO(4)-NaIO(4) sometimes suffers from low yields due to the formation of side products. It is found that the addition of 2,6-lutidine can suppress the side reactions and dramatically improve the yield of this classic reaction.

Aldehydes↗

PubMed2004

[Expression of VEGFA, VEGFC, angiopoietin-1, angiopoietin-2 and their receptors on yolk sac blood island, aorta-gonad-mesonephros (AGM) region of human embryo].

The study was to investigate the expression of VEGFA, VEGFC, angiopoietin-1, angiopoietin-2 and their receptors on yolk sac blood island, AGM region during gestation of 3th-12th weeks of human embryo. Human embryo contingently aborted at 3 - 12 weeks of gestation were collected with signed agreements of the pregnant women suffered from accidental abortions. The specimens were fixed by 4% paraformaldehyde and embedded by paraffin. 5 micro m serial sections were made. HE and immunohistochemistry method (SABC) and light-microscope were employed. The results showed that VEGFA and its receptors flt1/flk-1, VEGFC and its receptor flt-4, angiopoietin-2 and its receptor tie-2 proteins were expressed strongly and angiopoietin-1 was weakly expressed by hematopoietic cells and vascular endothelial cells of blood island at 21 and 25 days of gestation. In the 4th week of gestation, immuno-positive reaction of these factors and their receptors appeared in the aorta and mesonephros deposited in larger, rounded and nucleated cells which represented hematopoietic cells. Up to 7th week, positive hematopoietic cells in the regions were much abundant. The number of positive cells decreased at 8th week. Up to 12th week, almost all blood cells were immuno-negative. VEGFA, flt-1, flt-4, angiopoietin-1, angiopoietin-2 and Tie-2 protein were expressed mainly by gonad at 6 - 8 weeks, but it did not express VEGFC and flk-1. The immuno-reaction of the factors and their receptors could not detected in vascular endothelial cells during 3-12th weeks of gestation. It is concluded that hematopoietic cells and endothelial cells in blood island of yolk sac, mesonephros and dorsal aorta co-expressed some factors and their receptors in relation to vasculogenesis and hematopoiesis. Intraembryonic hematopoiesis began in the 4th week of gestation.

Angiopoietin-1↗

PubMed2004

[Expression of VEGFA, VEGFC, angiopoietin-1, angiopoietin-2 and their receptors on development liver during gestation of weeks 3-12 of human embryo].

The aim was to study the expression of VEGF-A, VEGF-C, angiopoietin-1, angiopoietin-2 and their receptors on development liver during gestation of weeks 3-12 of human embryo. Human embryo contingently aborted at 3-12 weeks of gestation were collected with signed agreements of the pregnant women suffered from accidental abortions. The specimens were fixed by 4% paraformaldehyde and embedded by paraffin. 5 microm serial sections were made. HE staining, immunohistochemistry method and light-microscope were employed. The results showed that at 4-5 weeks of development, liver was constituted by a few hepatic cords. Hematopoietic cell or blood cells were undetectable in the 4 week of gestation. A few cells which were larger, rounded and nucleared cells appeared and expressed VEGFA, flt-4 and Tie-2 proteins strongly in liver at 5 weeks of gestation. The number of these immuno-positive cells was highest in the 7th week and decreased at 11-12 weeks of gestation. These cells expressed flk-1 transiently in the 6th week. VEGF-C and flt-1 were expressed by hepatic cells from weeks 7 to 12 of gestation. The immuno-positive products were deposited in plasma of hepatic cells. Angiopoietin-1, angiopoietin-2 and Tie-2 were detectable on those cells which expressed VEGFA, flt-4 and Tie-2 from weeks 5 to 12 of gestation. The expression of angiopoietin-1 and angiopoietin-2 were weakly and Tie-2 was strongly. They were expressed weakly too by hepatic cells at 5 to 12 weeks of gestation. All factors and their receptors were undetectable on vascular endothelial cells at 4-12 weeks of gestation. It is concluded that the expression patterns of VEGF family on cells of liver are different before and after 7 weeks of gestation. The hematopoiesis in fetal liver may be related to development of hepatic cell.

Angiopoietin-1↗

PubMed2004

[The characteristics of hepatic stem cells and the expression of growth factor and their receptors in the early embryonic human liver].

To study the morphological characteristics of hepatic stem cells and the expression of HGF, IGF-I, TGFbeta1 and their receptors in human embryonic livers at 3-5 weeks of gestation. The SABC immunohistochemical method with HE counterstaining was employed. We found that the hepatic bud formed at the end of the 3rd week. At the 4th week, the cells of hepatic bud migrated into the septum transversum mesenchyme and formed the hepatic cords. The hepatic cells at 3-4 weeks displayed the typical characteristics of immature cells: small size, a round or ovoid nucleus with dark color, scant cytoplasm with slight blue and a high ratio of nuclei/cytoplasm. They were positive for alpha-Fetoprotein (AFP), c-Met and negative for cytokertin 19 (CK19), and proliferating cell nuclear antigen (PCNA). At the 5th week, compared to those at the 4th week, the number of cells within the hepatic cords increased. But the cells at the 5th week were homogeneous and displayed the typical characteristic of immature cells. Those cells began to express PCNA at the 5th week. The hepatic cells at the 5th week were positive for insulin-like growth factor I (IGF-I), transforming growth factor beta1 (TGFbeta1) and their receptors, and were negative for hepatocyte growth factor (HGF), while HGF were positive in the cardiac cells and septum transversum mesenchyme. The results indicated that the cells of hepatic bud and cords were the hepatic stem cells. The difference of morphology and proteins expression at 3-5 weeks of gestation inferred that those stem cells belong to different developmental stage. AFP and c-Met were the markers of hepatic stem cells at the early stage of human embryo. HGF, IGF-I, TGFbeta1 and their receptors may involve in regulating the development of early embryonic human liver.

Embryo, Mammalian↗

PubMed2003

Total synthesis of the highly potent anti-HIV natural product daurichromenic acid along with its two chromane derivatives, rhododaurichromanic acids A and B.

[reaction: see text] The highly potent anti-HIV natural product daurichromenic acid was successfully synthesized in only five steps with 49% overall yield. The key step in the synthetic strategy involves a microwave-assisted tandem condensation and intramolecular S(N)2'-type cyclization to form the 2H-benzopyran core structure.

Anti-HIV Agents↗

PubMed2003

Barrier and mechanical properties of milk protein-based edible films containing nutraceuticals.

Calcium caseinate (CC) and whey protein isolate (WPI) films were prepared to contain 5 or 10% Gluconal Cal (GC), a mixture of calcium lactate and gluconate, or 0.1 or 0.2% alpha-tocopheryl acetate (VE), respectively. The pH and viscosity of film-forming solutions and the water vapor permeability and tensile property of the films were determined using standard procedures. CC and WPI films have the capabilities to carry high concentration of GC or VE, but some of the film functionality might be compromised. Adding VE to CC and WPI films increased film elongation at break, whereas incorporating 0.2% VE decreased WVP of CC films and tensile strength of both CC and WPI films. Incorporation of GC reduced the tensile strength of CC films (P < 0.05), with 10% GC decreasing both elongation at break and WVP (P < 0.05). These types of films may be used for wrapping or coating to enhance the nutritional value of foods. The concentration of GC and VE added to the films must be carefully selected to meet required water barrier and mechanical properties of the films depending on their specific applications.

Biomechanical Phenomena↗