Biomedical subjects

L J Yang

Publications and source records attributed to L J Yang.

48 records · Page 3Linked to original sources

PubMed1990

Opportunities for bioactive compounds in transgenic plants.

A variety of bioactive compounds have now been introduced into plants through recombinant DNA techniques. Early examples included genes encoding proteins conferring herbicide tolerance and insect or virus resistance. More recently, pharmacologically useful compounds such as enkephalin and immunoglobulin have been produced in transgenic plants. Modification of existing compounds to provide better nutritional value or improved functional properties is exemplified in the case of seed storage proteins. The value of RNAs as bioactive compounds for suppression of undesirable products and viral infection has now been demonstrated in plants. The developmentally regulated expression of novel bioactive compounds in defined tissues, and their targeting to specific subcellular locations, is becoming of ever increasing economic and sociological importance as knowledge of the molecular mechanisms involved accumulates.

Endopeptidases↗

PubMed1990

Immunohistochemical analysis of bone morphogenetic protein (BMP) in osteosarcoma.

The monoclonal antibody against bovine bone morphogenetic protein (bBMP-McAb) was first used for demonstration of bone morphogenetic protein (BMP) in osteosarcoma. The avidin-biotin complex method (ABC) demonstrated that of the 18 osteosarcomas, 15 stained positive, while all 6 fibrosarcomas were negative. The results showed that BMP mainly exists in the tumor cell plasma and some tumor-like bone tissues. Using this staining method, we can not only differentiate osteosarcoma from fibrosarcoma and other non-bone-derived tumors, but also classify osteosarcoma according to the content and distribution of BMP and the patient's clinical situation, thus providing a scientific basis for clinical treatment.

Adolescent↗

PubMed1990

[Immunohistochemical localization of lectins in normal salivary glands and mucoepidermoid carcinoma].

5 kinds of Lectins (ConA, PNA, RCA, SBA and WGA) were used to observe the immunochemical localization of lectins in the cells of normal salivary glands and mucoepidermoid carcinoma. The result shows that in normal salivary glands ConA staining was found only in duct cells and serous acinar cells. Intercalated duct cells and striated duct cells of parotid and submandibular gland displayed RCA and WGA staining. The duct cells of sublingual gland and palatine gland did not react with lectin RCA. The ductal and acinar cells of normal salivary gland were not stained by PNA. Serous acinar cells of sublingual gland could be stained by SBA but mucous cells were negative. In tumor cells, ConA, RCA, WGA showed extensive staining which suggests the tumor cells contain similar glycoproteins as the normal duct cells. PNA was found in squamous epithelial cells but not in glandular epithelium. Its presence in tumor cells may indicate the degree of differentiation of these cells. Epidermoid and mucous cells of the tumor were also stained by 54 Kd antikeratin antibody. The results suggest this tumor may originate from the ductal cells of salivary gland.

Adolescent↗

PubMed1990

The relationship between bone morphogenetic protein and neoplastic bone diseases.

The monoclonal antibody against bovine bone morphogenetic protein was used for demonstration of bone morphogenetic protein (BMP) in neoplastic bone diseases. The avidin-biotin-peroxidase complex method demonstrated that BMP mainly exists in the cytoplasm of tumor cells of osteosarcoma and chondrosarcoma. Immunostaining showed that a majority of osteosarcomas and all of the chondrosarcoma cells contained a large quantity of BMP. Conversely, none of the fibrosarcomas showed positive staining. Thus, it was possible to differentiate osteosarcomas from fibrosarcomas by immunostaining. In fibrous dysplasia of bone, BMP was abundant in the fibrocellular tissue that had osteogenic activity. In contrast, fibrous tissue of ossifying fibroma showed weak positive staining; only the osteoblasts rimming the bone showed a positive reaction. Immunostaining showed that BMP was also detected in other neoplastic bone diseases such as osteoma, chondroma, and other tumors.

Antibodies, Monoclonal↗

PubMed1990

Immunohistochemical observations on bone morphogenetic protein in normal and abnormal conditions.

Localization of bone morphogenetic protein (BMP) in human tissues and cells is important for investigating the mechanism of bone induction. A stable cell line secreting monoclonal antibody against bovine BMP (bBMP-McAb) was obtained by the hybridoma technique. The result of immunohistochemical staining (ABC method) showed that BMP is distributed along collagen fibers of normal bone, in periosteal cells, and in mesenchymal cells of marrow stroma. Little BMP can be found in bone cells of lamellar bone or in calcified bone matrix. BMP may be abundant in human tooth anlagen such as predentin, cells of the outer and inner enamel epithelium, and cells of dental sac generating bone. BMP is found in the cytoplasm of tumor cells of osteosarcoma and chondrosarcoma. Immunohistochemical staining showed that BMP plays a role in bone fracture healing. The ability of BMP-McAb to detect BMP and to inhibit the generation of new bone also makes it potentially useful in diagnosing, treating, and providing a prognosis for osteosarcoma and other bone diseases.

Animals↗

PubMed1986