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L T Xu

Publications and source records attributed to L T Xu.

At least 19 recordsLinked to original sources
PubMed2006

The efficacy and economic benefits of Supercox, a live anticoccidial vaccine in a commercial trial in broiler chickens in China.

The efficacy and economic benefits of Supercox, a live anticoccidial vaccine were examined and compared with an anticoccidial drug in a trial in broiler chickens under modern commercial conditions in China. In total, 40,660 chickens were used in the present study, half of which were vaccinated with the Supercox vaccine comprising a precocious line of Eimeria tenella and non-attenuated lines of Eimeria maxima and Eimeria acervulina, and the other half were medicated with Diclazuril delivered as feed additive at the dosage of 1mg/kg of feed. The vaccine was administered orally to 7-day-old chickens. No clinical diseases were diagnosed in any of the vaccinated birds. However, clinical coccidiosis occurred in a large proportion of medicated control birds and these chickens had to be treated with anticoccidial drugs (Diclazuril and Toltrazuril). Comparison of production performance between vaccinated birds and medicated control birds revealed that the vaccine Supercox performed better than anticoccidial drugs in terms of mortalities, costs and overall economic benefits (profits). These findings demonstrated that the use of the Supercox vaccine could control clinical coccidiosis in broilers and achieve production performance superior to that using anticoccidial drugs, particularly where drug resistance might result in failure to control clinical diseases.

Animals↗
PubMed1999

Action of free radical in podophyllic acid piperindyl hydrazone nitroxide radical on its antitumor activity and toxicity.

AIM: To study the action of free radical in the spin-labeled podophyllotoxin derivative, podophyllic acid piperindyl hydrazone nitroxide radical (GP-1) on its antitumor activity and toxicity, by comparison with those of its free radical reduced product, podophyllic acid piperindyl hydrazone (GP-1-H). METHODS: After treatment with GP-1 and GP-1-H, the inhibitory effects on the growth of mouse transplantable tumors were determined; MTT formazan formation, [3H]deoxythymidine ([3H]TdR) incorporation, cell cycle progression, and mitotic index of SGC-7901 or L1210 cells were measured; the acute toxicity and immune function of mice were assayed. RESULTS: At doses of 1/6 and 1/12 LD50, the inhibitory rates against Lewis lung carcinoma were 60.3% and 42.1% (GP-1), 38.9% and 10.3% (GP-1-H), respectively; more effective antitumor activity of GP-1 against P388, HePS, and S-180 than that of GP-1-H were found. In vitro, GP-1 exhibited more powerful inhibitory effects on the proliferation and DNA synthesis of SGC-7901 and L1210 cells than GP-1-H. GP-1 and GP-1-H arrested the L1210 cells at G2/M phase with a corresponding decrease of the cells in G1 phase, and increased the mitotic index of the cells; but the effects of GP-1-H were weaker than those of GP-1. After treatment with doses of 1/4 and 1/8 LD50 for 5 d, no significant difference on immune function of mice between GP-1 and GP-1-H was found. CONCLUSION: GP-1 had more powerful antitumor activities than GP-1-H. The free radical in the spin-labeled podophyllotoxin derivative, GP-1, played an important role in its antitumor activity.

Adenocarcinoma↗
PubMed1995

[HPLC determination of 4-[4"-(2",2",6",6"-tetramethyl-1"-piperidinyloxy) amino]-4'-demethylepipodophyllotoxin in rat plasma and studies of its pharmacokinetics].

4-[4"-(2",2",6",6"-tetramethyl-1"-piperidinyloxy) amino]-4'- demethylepipodophyllotoxin (GP-7) is a new podophyllotoxin spin-labeled derivative. Its primary effect is the antitumor activity on transplanted mouse tumors and cultured tumor cells. This paper describes a method for its determination using HPLC with UV detection and the determination of its pharmacokinetic parameters in rats. A Shimadzu LC-6A liquid chromatograph equipped with a Shimadzu SPD-6AV multiwavelength detector and a Chromatopac C-R3A data processor was used. The separation was performed on a Zorbax-ODS column (5 microns, 4.6 mm x 150 mm) with a mobile phase of methanol--water--glacial acetic acid (59:41:0.6). The flow-rate was 1.0 ml.min-1 and detection was made at 285 nm. A plasma specimen (0.2 ml) was spiked with 22.6 micrograms.ml-1 internal standard (podophyllic acid piperidinyl hydrazone nitroxide radical, GP-1) and extracted with ether--dichloromethane (3:1). The extract was evaporated at 45 degrees C. The residue was taken up with 0.1 ml of the mobile phase and 20 microliters aliquots were injected into the system. The calibration curve was linear in the range from 2 to 200 micrograms.ml-1 with r = 0.9997. The detection limit was 0.2 microgram.ml-1 and the recovery of GP-7 from rat plasma was 94.3%-100.9%. The relative standard deviations for within- day and between-day were 2.29%-4.64% and 5.55%-7.70%, respectively. After iv injection of GP-7 10, 20 and 30 mg.kg-1, the concentrations of the drug in rat plasma were determined. The pharmacokinetic parameters of GP-7 were obtained by using MCPKP program on a COMPAC-486 computer. The data obtained fitted a two-compartment open model, and the mean T1/2 beta value was 39.8 +/- 10.8 min.

Animals↗
PubMed1993

Apoxesis of primary tracheal tumor. A clinical analysis of 23 cases.

During a 17-year period, 23 patients with primary tracheal tumors underwent surgical treatment in the Department of Thoracic Surgery, PUMC Hospital (11 cases of benign tumor of the trachea, 12 cases of low malignancies). Fourteen times of apoxesis were performed in 11 patients with benign tumors who were followed up for an average of 6.3 years. Fifteen operations were performed in 12 cases including local resection of the tracheal wall and tumor in 4, and curettage of tumor plus electric cauterization on the basis in 10. Eight of 9 patients with adenoid cystic carcinoma received postoperative adjuvant irradiation, with a 5-year postoperative survival rate of 75% (6/8) and 3 cases survived over ten years. The desirability of apoxesis and local resection of tracheal tumor is discussed. The authors suggest that these two surgical patterns can be regarded as a simple and effective treatment for patients with primary tracheal tumors.

Adolescent↗
PubMed1992

[Total gastrectomy via thoracotomy for cancer of gastric cardia and fundus. Report of 90 cases].

From 1978 through 1990, 90 total gastrectomy with esophagojejunostomy via thoracotomy were performed for the treatment of cancer of cardia or fundus of stomach. 85/90 patients were at TNM III-stage and 5/90-at IV-stage. 30-day post-resectional mortality was 1.1%. Five-year survival rate was 13.8%. 14CO2 respiratory test and clinical evaluation of 34 post-operative patients showed that total gastrectomy may decrease the incidence of positive residual cancer along the incision lines. It may also spare the patient from small-stomach syndrome. There was no statistical difference in postoperative fat absorption and digestive function between ordinary proximal subtotal gastrectomy and total gastrectomy.

Adenocarcinoma↗
PubMed1990

Early and late results of total gastrectomy in treatment of advanced adenocarcinoma of the cardia.

Sixty-six patients with advanced adenocarcinoma of the cardia underwent total gastrectomy between 1978 and 1986. The operative morbidity rate was 7.5% and the hospital mortality rate (1 month) was 1.5%. The postoperative 1, 3, 4, and 5 year survival rates were 69%, 30.7%, 20% and 13.8% respectively. The quality of life after surgery was improved. Pathological type, lymph node metastasis, completeness of resection and postoperative chemotherapy were the main factors influencing postoperative survival time. Indications for total gastrectomy and the advantages of transthoracic total gastrectomy are discussed.

Adenocarcinoma↗
PubMed1987

Clinical and pathologic characteristics in patients with tracheobronchial tumor: report of 50 patients.

From January, 1961, to July, 1985, 50 patients in the Peking Union Medical College Hospital with intraluminal tracheobronchial tumors were operated on. There was no gender or age predominance either in the 24 patients with tracheal tumor or in the 26 patients with bronchial tumor. The 13 cell types found in these patients' specimens were divided into four groups: malignant, low-grade malignant, benign with tendency to recur and benign without tendency to recur. Squamous cell carcinoma and adenoid cystic carcinoma were the most common tumors of the trachea. Carcinoid and adenoid cystic carcinoma were the most common tumors of the bronchus in this group of patients. Conservative excision with postoperative irradiation may be sufficient for patients with advanced lesions of low-grade malignancy.

Adolescent↗
PubMed1985

Resection of pulmonary metastatic choriocarcinoma in 43 drug-resistant patients.

A regimen of multiple intermittent intensive doses of chemotherapy (chiefly 5-fluorouracil) was used in a series of 806 women with choriocarcinoma and malignant mole. The rate of complete remission of choriocarcinoma was 78.6%, and approximately 85% of the patients survived for more than 5 years. From 1962 through 1982, pulmonary metastatic choriocarcinoma was found to be resistant to chemotherapeutic agents in 43 of these patients; they subsequently underwent lung resection. There were no postoperative deaths, and the 5-year survival was 50%. These are relatively good results for patients with long-standing and widely disseminated choriocarcinoma. Human chorionic gonadotropin titer in urine and blood and variations of lung shadows are important criteria in selecting candidates for lung resection. For preservation of lung function, simple lobectomy is the first choice. Better long-term survival was obtained in patients who had a solitary lung lesion on admission without other major organ metastases and in those in whom the lung lesion was well encapsulated and became necrotic after chemotherapy.

Adult↗