Biomedical subjects

Kai-ming Yang

Publications and source records attributed to Kai-ming Yang.

3 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↗

PubMed2006

[Role of Wnt/beta-catenin signaling transduction pathway in rat hepatocarcinogenesis].

AIM: To investigate the role of Wnt/beta-catenin signaling transduction pathway in rat hepatocarcinogenesis. METHODS: The mRNAs of Wnt1, beta-catenin, APC, cyclin D1 and c-myc genes were amplified by using of semiquantitative reverse transcription polymerase chain reaction (RT-PCR) from normal rat livers, atypical hyperplasia livers and hepatoma tissues, respectively. Then the proteins expression of beta-catenin, APC and cyclin D1 was examined by immunohistochemical staining. RESULTS: In normal rat livers, the mRNAs of Wnt1, cyclin D1 and c-myc genes were not detected and only beta-catenin protein was observed to have low expression at cellular membrane. However, 14 weeks after cancer induction in atypical hyperplasia livers, beta-catenin protein and APC protein were accumulated in cytoplasm. Meanwhile, cyclin D1 protein was detected in cytoplasm and/or nucleus in some cells. 16 weeks after cancer induction in hepatoma tissues, the mRNAs and protein expression of beta-catenin, APC, cyclin D1 and c-myc genes were detected except Wnt1. CONCLUSION: The activation of Wnt/beta-catenin signaling transduction pathway might be one of the reasons for rat hepatocarcinogenesis.

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↗