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Biomedical subjects

K Katayama

Publications and source records attributed to K Katayama.

At least 595 records · Page 33Linked to original sources

Prophylaxis with intraoperative chemohyperthermia against peritoneal recurrence of serosal invasion-positive gastric cancer.

Continuous hyperthermic peritoneal perfusion (CHPP) with a solution which contains 30 mg mitomycin C and 300 mg cisplatin has been introduced as a prophylactic treatment for peritoneal recurrence after curative resection of 79 advanced gastric cancers. The control group consisted of 81 patients with advanced gastric cancer who underwent curative surgery during the same period. CHPP was performed for 60 minutes by perfusing MMC- and CDDP-containing saline solutions warmed at 43.5 degrees C by a special CHPP device. In patients with pathologically confirmed serosal invasion-positive tumors, the survival rate of the CHPP group was significantly higher than that of the control group. A survival advantage for stage IV patients was also obtained by CHPP. However, there was no survival advantage between the CHPP group and the control group with serosal invasion-negative tumors. Adverse effects were observed in four patients who underwent CHPP: One developed severe bone marrow suppression, and transient hyperazotemia was observed in the other three. There was no difference in the incidence of mortality and morbidity between the two groups. These results indicate that CHPP is a safe, readily available prophylactic therapy for peritoneal recurrence after gastric cancer surgery.

Antineoplastic Combined Chemotherapy Protocols↗

Adenylate cyclase activation promotes the recruitment of coronary vasodilator reserve and improves subendocardial contractility during coronary hypoperfusion.

This study was designed to examine the effects of an adenylate cyclase activator, NKH477, on epicardial and endocardial contraction and coronary blood flow (CoF) in the presence or absence of ischemia and to compare it to those of adenosine. We measured coronary pressures (CoP), coronary blood flow, epicardial and endocardial wall thickening (i.e., %EPWT and %ENWT, respectively, by sonomicrometry) in 18 anesthetized dogs. The left circumflex coronary artery was perfused with arterial blood using a pressure controlled servo pump. Propranolol (0.5 mg/kg) and atropine (0.25 mg) were used to minimize the neurogenic effects. CoP decreased from 100 mm Hg to 40 mm Hg with and without drugs. At CoP of 100 mm Hg, intracoronary infusion of NKH477 (10(-8) M/kg/min) produced a two-fold increase in CoF, but there were no changes in either the %EPWT or the %ENWT. During coronary hypofusion at coronary pressures equal to 40 mm Hg, NKH477 increased CoF from 16 +/- 2 to 28 +/- 4 mL/min (p < 0.05) and improved %ENWT significantly from 6 +/- 7 to 23 +/- 7% (p < 0.05). However %EPWT was not improved by NKH477. On the other hand, the intracoronary infusion of adenosine (10 micrograms/kg/min) increased CoF from 16 +/- 5 to 21 +/- 6 mL/min (p < 0.05) at CoP of 40 mm Hg. However, this dose of adenosine failed to improve %ENWT (16 +/- 10% vs. 14 +/- 10%, n.s.). Thus, the improvement of subendocardial function by NKH477 might be related to the improvement of subendocardial perfusion which could be induced by the potentiation of endogenously released adenosine as well as the direct vasodilator effect. This contrasts with the effects of exogenously administered adenosine, which failed to improve subendocardial contractility.

Adenosine↗

Time-course of left atrial performance during coronary artery occlusion followed by reperfusion in anesthetized dogs by densitometric analysis of digital atrioventriculographic images.

The left atrial (LA) function during coronary artery occlusion followed by reperfusion using densitometric analysis of digital atrioventriculographic images was evaluated. Eight anesthetized dogs underwent atrioventriculography at baseline, 10 and 60 min after left circumflex coronary artery (LCX) occlusion and 5, 30, 60, and 120 min of reperfusion. Time-density curves were obtained for LA and left ventricle (LV). The ratios of passive atrial video-densitometric change (VC) to total VC (Passive Ratio), and active VC to total VC (Active Ratio) were calculated. Left ventricular ejection fraction (LVEF), peak ejection rate (PER), and peak filling rate (PFR) were derived. Active Ratio, an index of atrial contraction, increased to 144%, and Passive Ratio decreased to 75% of baseline at 60 min of LCX occlusion. Two hours after reperfusion, both Active and Passive Ratios returned to control level. While LVEF reduced to 70%, PER to 67%, LV peak positive dP/dt to 88% of baseline at 60 min after occlusion, and remained depressed at 2 h after reperfusion. However, PFR, LV peak negative dP/dt and LV isovolumic pressure decay rate showed recovery at 2 h after reperfusion. There were significant correlations between PFR and Passive Ratio (r = 0.41), and between Active and Passive Ratios (r = 0.55). Thus, time-course of recovery of LV post-ischemic systolic and diastolic function was different. Return of LA function to control level during 2 h after reperfusion may be depend on recovery of LV diastolic function.

Animals↗