Biomedical subjects

N Zempo

Publications and source records attributed to N Zempo.

77 records · Page 5Linked to original sources

PubMedDate not supplied

Digitonin enhances the anti-tumor effect of cisplatin against methylcholanthrene-induced rat sarcoma cells in vitro.

BACKGROUND: This study was designed to evaluate cellular uptake and cytotoxicity of cisplatin in methylcholanthrene (MCA)-induced rat sarcoma cells when used in combination with a detergent, digitonin. MATERIALS AND METHODS: In the cellular intake study, after MCA sarcoma cells (10(7)) were treated with cisplatin alone (50 micrograms/ml) and with cisplatin (50 micrograms/ml) in combination with digitonin at 20 microM and 50 microM, the cells were washed twice with PBS and the platinum levels were measured by flameless atomic spectrometry. For the anti-tumor effect MCA sarcoma cells (10(3)) were seeded in cell culture dishes and loaded for 10 minutes with PBS, digitonin (5 microM), cisplatin (5 micrograms/ml) or a combination of cisplatin (5 micrograms/ml) and digitonin (5 microM). The cells were then washed and incubated for 72 hours. Bromodeoxyuridine uptake was measured with an ELISA system for determining viable cells counts. RESULTS: Cell platinum levels were significantly elevated in proportion to the increase of digitonin (p < 0.0001). The number of viable cells was significantly decreased with, the combined cisplatin (5 micrograms/ml)--digitonin (5 microM) treatment (p < 0.0001 CONCLUSION: Digitonin enhances the antitumor effect of cisplatin against methylcholanthrene-induced rat sarcoma in vitro.

Animals↗

PubMedDate not supplied

Increasing drug concentration in a rat lung tumor model by combining isolated lung perfusion with hypertensive chemotherapy.

Isolated left lung perfusion (ILP) with cisplatin was performed in Fisher 344 rats. Before perfusion, bolus injection with endothelin was given via the pulmonary artery. The vasoconstrictive potency was estimated by monitoring the perfusion pressure. The toxicity was estimated by tracking body weight change, survival rate after right pneumonectomy, arterial blood gas analysis and histological findings. To observe the pharmacokinetic changes, a solitary Methylcholanthrene-induced sarcoma model was established in a rat lung and the total platinum concentration in perfused lung and tumor tissues was measured. Perfusion pressure was increased significantly in a dose-dependent manner. Pulmonary toxicity from ILP with cisplatin was limited by the use of endothelin. Significantly higher levels of total platinum were obtained in tumors but not in normal lung tissues by endothelin injection before ILP than by ILP alone. The combination of ILP and hypertensive chemotherapy should be one of the available treatments for unresectable pulmonary carcinoma.

Animals↗

PubMedDate not supplied

99mTc-HSA lymphoscintigraphy and leg edema following arterial reconstruction.

Twelve patients with peripheral arterial occlusive disease were evaluated prospectively in an effort to further investigate the etiology of pedal and lower leg edema that occurs following revascularization (e.g., aorto-iliac or femoropopliteal bypass). Serum total protein, albumin, blood urea nitrogen, and creatinine levels were measured (in addition to peripheral venous pressure), and lymphoscintigraphy of the lower leg was performed. These parameters were assessed just prior to surgery, four weeks postoperatively, and again at follow-up. The serum levels obtained four weeks after surgery and on subsequent follow-ups were significantly higher than the preoperative values. Preoperative peripheral venous pressure was not significantly different from that obtained after surgery. There was no correlation between these pressure measurements and the degree of edema (Grades I to IV correspond to increasing degrees of severity). For both the supine and upright positions, lymphoscintigraphic counts in the inguinal region were significantly higher after surgery. However, the relative increase was dependent upon the severity of edema. The postoperative lymphoscintigraphic count in the upright position was 77 +/- 33 CPS in patients with Grades I and II edema (n = 6) and 20.6 +/- 16.2 CPS in patients with Grades III and IV edema (n = 10) (p less than 0.01). Thus, a lesser degree of postoperative pedal and lower leg edema was associated with higher lymphoscintigraphic counts. We conclude that major contributors to the development of lower extremity edema following arterial reconstruction are failed capillary hydrostatic pressure and interrupted lymphatic drainage.

Aged↗

PubMedDate not supplied

Is the preferential use of polytetrafluoroethylene grafts for below-knee femoropopliteal bypass justified?

The usefulness of polytetrafluoroethylene graft (PTFE) for primary below-knee femoropopliteal bypass was examined. Forty-five primary femoropopliteal bypasses with PTFE were performed in 35 patients during a 7-year period. Patients were divided into two groups: above-knee (A-K group, n = 20) and below-knee (B-K group, n = 25) bypass. Differences in intergroup patient demographics were not significant. The primary patency rate in the A-K group at 3 and 5 years was 83.6% and 50.2%, respectively, and was 76.2% at both 3 and 5 years in the B-K group. These differences were not significant. Cause of graft failure, 3 grafts in the A-K group and 5 grafts in the B-K group, was kinking or thrombus formation associated with intimal hyperplasia at the distal anastomosis. All grafts in the A-K group with more than 10% stenosis in the early postoperative period had more than 50% stenosis in the late postoperative period. On the other hand, the one graft in the B-K group with 25% stenosis in the early postoperative period had 50% stenosis in the late postoperative period. We concluded that the use of PTFE for primary below-knee femoropopliteal artery is reasonable when atherosclerosis in the proximal popliteal artery is slight. However, close follow-up is necessary to detect and treat graft stenosis early.

Aged↗

PubMedDate not supplied

Effect of elastase on primary graft patency after femoralpopliteal arterial bypass for arteriosclerosis obliterans: a randomized, controlled study.

METHODS: Studies were carried out on 104 limbs with femoralpopliteal bypasses for arteriosclerosis obliterans (ASO). They were randomized to a group receiving elastase (10800 EL. U. P.O. per day) with an antiplatelet drug (Elastase group, 58 patients) or a group receiving only the antiplatelet drug (Control group, 46 patients). The follow-up period ranged from 24 to 36 months after operation at 22 institutions across Japan. RESULTS: The cumulative graft patency rate was higher in the Elastase group than the Control group, but the difference lacked statistical significance. When autogenous saphenous veins were used, the cumulative graft patency rate was significantly higher in the Elastase group than the Control group. CONCLUSIONS: The present study suggests that elastase is effective in maintaining graft patency in femoralpopliteal arterial bypass when an autogenous saphenous vein is used as a graft.

Aged↗