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Biomedical subjects

P Jiang

Publications and source records attributed to P Jiang.

115 records · Page 7Linked to original sources

Studies on the sites expressing evolutionary changes in the structure of eukaryotic 5S ribosomal RNA.

We have determined the complete sequences of 5S rRNAs from a lamprey (Lampetra reissneri), a lancelet (Branchiostoma belcheri), silkworms (Philosamia cynthia ricini, Bombyx mori, Antheraea pernyi), and a silkworm hybrid (artificially fertilized hybrid species of Philosamia cynthia ricini male x Bombyx mori female), as well as those of cotton seeds (Gossypium hirsutum L.). Having compared more than 170 eukaryotic 5S rRNAs of which seven sequences have been determined by our group as mentioned above, we have found that the "evolutionary sites" that exist at special locations in these structures are closely related to the evolution of eukaryotes. The changes proceed step by step in an orderly way, i.e., the change in nucleotide residues of the "evolutionary sites" depends on the order of the evolution of the species and shows group-specific patterns.

Animals↗

The superiority of combined therapy (surgery and postoperative irradiation) in parotid cancer.

A retrospective evaluation was done on 120 patients treated for parotid cancer. The aim of the study was to establish the role of postoperative radiation therapy. Fifty-nine patients were treated by surgery plus postoperative radiation therapy. Two patients were treated by preoperative irradiation. The overall 5-, 10-, and 15-year survival rates were 81%, 62%, and 65%, respectively. Postoperative radiation therapy proved to increase local control over surgery alone whenever (1) there was locally advanced disease, (2) the tumor belonged to a so-called poorly differentiated variety, (3) the treatment was given for a recurrent lesion, and/or (4) there was tumor involvement of the facial nerve. It did not appear that postoperative radiation therapy increased the survival for patients with low-grade malignant tumors. Radiation therapy should be given as early as possible after surgery and the optimum dose ranges from 3,000 to 5,000 rad given in three to five weeks, respectively.

Facial Nerve↗

A nude mouse model of massive liver and lymph node metastasis of human colon cancer.

Liver and lymph nodes metastasis are the main causes of treatment failure for advanced colon cancer. However, currently-available animal models of human colon cancer do not demonstrate sufficient metastasis to represent highly malignant colon cancer that extensively metastasizes to these sites. A liver metastasis from a patient with highly malignant, poorly differentiated adenocarcinoma of the colon was established in nude mice by surgical orthotopic implantation to the mouse colon. The human origin of the tumor growing in nude mice was confirmed by in situ hybridization of human DNA. After 20 passages from the first implantation, massive liver and lymph nodes metastasis, occurred in 100% of the transplanted animals. Lymph nodes metastasis were found at the sites of lymph node drainage of the liver: celiac, portal and mediastinal lymph nodes. However no mesenteric and retroperitoneal nodes or lung tissue metastases were observed. Our data suggest that the mediastinal, celiac and hepatic lymph nodes metastases are derived form the liver metastasis, confirming the concept of metastasis of metastases or "remetastasis" of colon cancer.

Adenocarcinoma↗

Study on immobilization of aminoacylase from Aspergillus oryzae on macroporous copolymers.

The aminoacylase from Aspergillus oryzae was adsorbed on polymer carriers where the enzyme showed excellent catalyzing activity and operating stability. It was found that the pore structure and functional group were the basic factors which affected the activity of the adsorbed enzyme. The hydrophobility of the carriers did not play an important role in the enzymatic resolution. Various factors, such as percentage and nature of cross-linking agent, porogenic agents and functionalizing agents which controlled the pore structure and properties of the polymer carriers during their preparation, were investigated and relationship between the activity of the adsorbed aminoacylase and the carrier structure was also discussed.

Adsorption↗