Biomedical subjects

Ai-dong Li

Publications and source records attributed to Ai-dong Li.

10 recordsLinked to original sources

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↗

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

[Expression of CD34, CD14, CD10, CD31 and factor VIII on hematopoietic cells of yolk sac blood island, AGM region and liver of human embryo and fetus].

OBJECTIVES: To study the expression of CD34, CD31, CD14, CD10 and factor VIII on blood island of yolk sac (YS), PAS/aorta-germen-mesonephros (AGM) region and hepatic hematopoietic foci. METHODS: Thirty-two cases of 3rd-12th weeks human embryo were obtained by drug abortion. Paraffin embedded sections with H.E staining and immunohistochemistry reaction (SABC) were performed. RESULTS: YS blood island of 3rd-4th weeks of gestation was consisted of two types of cells. One was vascular endothelial cells located outside and the other hematopoietic cells inside the blood island. Both the two types of cells were CD10, CD14, CD31 and factor VIII positive. Hematopoietic cells were CD34 negative, and vascular endothelial cells were CD34 positive. On 32nd days of gestation, the hematopoietic cells migrated out of YS. On 4th week of gestation, CD34, CD14, CD10, CD31 and factor VIII positive cells appeared in the aorta, mesonephros and hepatic hematopoietic foci. By the 7th week, the number of positive hematopoietic cells reached the peak. In 11th-12th weeks, most cells in these regions were matured red blood cells and were negative for all the antibodies mentioned above excepting for CD34. During 4th-12th weeks, all endothelial cells in embryo were CD34 positive. CONCLUSIONS: The hematopoietic cells and endothelial cells of YS blood island co-expressed CD10, CD14, CD31 and factor VIII. Endothelial cells were CD34 positive but hematopoietic cells were negative in YS blood island. The hematopoietic cells of aorta, mesonephros and hepatic hematopoietic foci expressed CD34, CD10, CD14 and factor VIII from 4th week to 7th week. Anti-CD34 antibody could label endothelial cells of every kinds vessels of embryo from 3rd to 12th weeks.

Antigens, CD34↗

PubMed2005

[A clinicopathological analysis of gastric lymphoma].

OBJECTIVE: To discuss the clinicopathological features and prognostic factors of gastric lymphoma. METHODS: 83 gastric lymphoma cases were analyzed retrospectively in accordance to the criteria of the new World Health Organization classification for neoplastic diseases of the hematopoietic and lymphoid tissues. The correlations between clinicopathological features, therapeutic measures and survival were discussed. RESULTS: The age of patients ranged from 25 to 77, with a median of 52. The number of males were similar to that of females. There were no specific symptoms. The most common symptoms were stomach ache (60 cases, 72%) or discomfort. The duration of symptoms was often long and with a history of chronic gastric diseases (21 cases, 25%). 13 cases had multiple lesions in the gastrointestinal mucosa. 51 cases (61%) were accompanied by lymph node involvement. According to the new World Health Organization classification for neoplastic diseases of the hematopoietic and lymphoid tissues, 57 cases were extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT)-type (MALT lymphoma), 23 were diffuse large B cell lymphoma accompanying MALT lymphoma, 2 were diffuse large B cell lymphoma and 1 was follicular lymphoma. Of all the cases, 31 were stage I E, 38 stage II E, 8 stage III E and 6 stage IV by the Ann Arbor staging system (1972). The total 5-year and 10-year survival rates were 77.8% and 70.1% respectively, with the mean survival time of 146 months. The 5-year and 10-year survival rates of MALT lymphoma were 77.4% and 72.3%, the 5-year and 10-year survival rates of diffuse large B cell lymphoma accompanying MALT lymphoma were 81.8% and 68.2%, the 5-year survival rate of diffuse large B cell lymphoma was 50.0%. CONCLUSIONS: There are no specific symptoms in gastric lymphoma patients. Extranodal marginal zone lymphoma of MALT-type is the main histopathological type of gastric lymphoma, often accompanied by multiple mucosa involvement and also often accompanied by a history of chronic gastric disease. The lesion is usually localized for a long time, with a very good prognosis. Survival rate has a significant correlation with lymph node involvement and clinical stage. No correlations were found between the survival rates with age, gender, B symptoms, invasive depth of the wall of stomach, the size and range of the tumors or different therapeutic measures.

Adult↗

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

[Gene expression of matrix metalloproteinase 14 in laryngeal squamous cell carcinoma].

OBJECTIVE: To investigate the role of expression of matrix metallo-proteinase 14 (MMP14) in laryngeal carcinomas and the relationship between MMP14 expression and the laryngeal biological behavior. METHODS: The gene expression differences of MMP14 between fresh laryngeal cancer tissues and their surrounding normal mucosa was analyzed by RT-PCR. The expression of MMP14 protein in paraffin-embedded tissues was determined immunohistochemically. All statistical analyses were performed by SPSS version 10.0. RESULTS: In the 33 cases of matched specimens, MMP14 gene expression was much higher in tumor tissues than that in surrounding ing normal tissues in 26 cases and lower in 2 cases, whereas in other 5 cases, no significant difference was observed between the cancer tissue and the surrounding normal tissue. MMP14 gene expression was not different in different stages in laryngeal glottic cancers, but correlated to the differentiation and lymph node metastasis (P < 0.05). There was correlation between MMP14 gene expression and the stage, differentiation and lymph node metastasis in the laryngeal supraglottic cancers (P < .05). MMP14 protein was localized predominantly in the carcinoma cell cytoplasm and in the stromal fibroblast cytoplasm, and weakly or not expressed in surrounding normal tissue. MMP14 protein expression was much higher in tumor tissue than that in surrounding normal tissue in most of the cases. In general, MMP14 protein expression was the same as MMP14 gene expression and related to the stage, differentiation and lymph node metastasis in the laryngeal cancers. There was no survival difference at 3, 5 and 7-year between the group with higher MMP14 protein expression in tumor tissues than surrounding normal tissues and the group with no difference of MMP14 protein expression (Log Rank, P=0.5535). CONCLUSIONS: The protein MMP14 may play role in laryngeal cancer invasion in a certain extent, but important role in lymph node metastasis of laryngeal cancer. The over-expression of MMP14 protein may be a marker for lymph node metastasis of laryngeal cancer.

Carcinoma, Squamous Cell↗

PubMed2003

[Interaction of Helicobacter polyri and indomethacin in gastric mucosa injury of Balb/c mice].

OBJECTIVE: To investigate the interaction of Helicobacter pylori (Hp) and indomethacin in gastric mucosa injury of Balb/c mice. METHODS: Fifty specific pathogen free 6-week-old Balb/c mice were randomly divided into 5 groups: group A (n = 8, 25 mg/kg indomethacin was injected intraperitoneally every other day for 6 times, and 0.2 ml Hp culture containing 1 x 10(8) - 1 x 10(9) CFU/ml was inoculated intra-gastrically every other day for 6 times), B (n = 8, 1 x 10(8) - 1 x 10(9) CFU/ml Hp culture was inoculated intra-gastrically on the 1st, 2nd, and 3rd days, and since the 7th day 25 mg/kg indomethacin was injected intraperitoneally every other day for 6 tomes), group C (n = 9, 0.2 ml normal saline was inoculated intra-gastrically on the 1st, 2nd, and 3rd days and since the 7th day 25 mg/kg indomethacin was injected intraperitoneally every other day for 6 times), group D (n = 10, 1 x 10(8) - 1 x 10(9) CFU/ml Hp culture was inoculated intra-gastrically on the 1st, 2nd, and 3rd days, and since the 7th day 0.2 ml normal saline was injected intraperitoneally every other day for 6 times), and group E (n = 10, 0.2 ml normal saline was inoculated intra-gastrically on the 1st, 2nd, and 3rd days, then 0.2 ml normal saline was injected intraperitoneally since the 7th day every other day for 6 times). The mice were killed in the 4th week. The stomachs were observed morphologically. Tissues from gastric antrum underwent HE staining, silver staining, and urease examination. Rauws classification was used to grade the gastritis thus discovered. RESULTS: Two mice in group A, one mouse in group B and 2 mice in group C died. One mouse in group B was Hp silver staining negative. Twenty-six of the total 30 mice infected with Hp showed inflammation with an infection rate of 66.7%. Moderate to severe inflammatory reaction was seen in all 8 mice in group A with an average gastritis score of 6.38 and with Hp found in the epithelium. Two out of the 8 mice in group showed focal erosion. All mice in group B showed moderate inflammation and Hp in mucosa with an average gastritis score of 5.13. Focal erosion was seen in one mouse in group B. Light moderate inflammation was seen in all 9 mice in group C with an average gastritis score of 3.89. Mild inflammation was seen in all 10 mice in group D with an average gastritis score of 2.8. No erosion was found in groups C and D. No inflammation was seen in the mice in group E with an average gastritis score of 0.4. The differences between any 2 groups were all significant. CONCLUSION: Hp and indomethacin synergetically aggravate the gastric epithelial injury. Prior Hp infection may be a protective factor of indomethacin-induced gastritis to a certain degree.

Animals↗