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Biomedical subjects

S Aoyagi

Publications and source records attributed to S Aoyagi.

313 records · Page 18Linked to original sources

Development of a new endotoxin sensor with intermittent injection of limulus reagent for continuous monitoring of dialysate fluid.

This report describes a method of continuously, stably, and inexpensively measuring endotoxin (ET) concentrations in dialysate fluid using an ET sensor with intermittent injection of limulus reagent. An ET solution simulating dialysate fluid was sampled in a single tube at a flow rate of 260 microliters/min and mixed with 30 microliters of limulus reagent intermittently injected into the tube. The absorbance of the solution was measured after the limulus reaction at 313 or 318 degrees K at 26 min. A good linear relationship (r = 0.98) between peak area of absorbance and ET concentration at ET concentrations ranging from 0 to 0.12 endotoxin unit (EU)/ml was obtained, using a spectrophotometer with a cell volume of 8 microliter. The baseline rose after the measurements were taken because the cell volume was so small that the cell was stuffed with gel. A good linear relationship (r = 1.00) at ET concentration of 0.1-0.25 EU/ml was also obtained, and the baseline was unchanged after measurements, using a metal free spectrophotometer with a cell volume of 420 microliters. In conclusion, to measure ET concentrations below 0.1 EU/ml, the cell volume of a metal free spectrophotometer should be minimal.

Animals↗

Hepatic arterial infusion chemotherapy with continuous low dose administration of cisplatin and 5-fluorouracil for multiple recurrence of hepatocellular carcinoma after surgical treatment.

To date, conventional treatments for multiple intrahepatic recurrence of hepatocellular carcinoma (HCC) after surgery are unsuccessful. The aim of this retrospective study was to evaluate the prognostic effectiveness of a new infusion chemotherapy of cisplatin (CDDP) and 5-fluorouracil (5-FU) via hepatic artery for HCC with multiple intrahepatic recurrence. Fifty-two patients, who had postoperative multiple recurrence of HCC (more than 3 tumors), were enrolled in this study. Thirty-one patients were treated by hepatic arterial infusion chemotherapy via a subcutaneously implanted injection port. A one-week course of this treatment consisted of daily administration of cisplatin (10 mg for 1 h on days 1-5) and subsequent daily administration of 5-fluorouracil (250 mg for 5 h on days 1-5). Three to six sequential one-week courses were performed (the CDDP,5-FU group). Twenty-one patients underwent conventional interventional therapies including transcatheter arterial chemoembolization, lipiodolization (the conventional group). The complete response rate and the effective response rate in the CDDP,5-FU group were 29.0% and 71.0%, respectively. The 5-year survival rate in this group was 45.7%, which was significantly better than that in the conventional group. Based on multivariate analysis, CDDP,5-FU hepatic arterial infusion chemotherapy was found to be significant in prolonging survival, and this treatment achieved favorable therapeutic results for multiple recurrence of HCC. As part of a multidisciplinary approach this treatment is expected to improve the prognosis of patients with advanced HCC.

Adult↗

Metachronous multicentric occurrence of hepatocellular carcinoma after surgical treatment - clinicopathological comparison with recurrence due to metastasis.

This study investigated clinicopathological features of patients with recurrence of metachronous multicentric occurrence by comparison with patients with recurrence due to metastasis. In 177 patients, recurrences after curative surgical treatment were classified into recurrence due to metastasis according to criteria based on imaging findings. This group consisted of 35 patients. Among the rest of the patients, 59 underwent fine needle biopsies for recurrent tumor and, in these patients, a classification of recurrence of metachronous multicentric occurrence was made based on the histological findings of primary and recurrent tumor. This group consisted of 33 patients. The estimated incidence for recurrence of metachronous multicentric occurrence was 44.8% to total total patients. Metachronous multicentric occurrence frequently developed in patients with anti-HCV antibody and an early stage of primary tumor. In 80% of the patients who had recurrent tumor of multicentric origin, the recurrence developed within 3 postoperative years. The survival rate in patients with metachronous multicentric occurrence was significantly higher than that in patients with recurrence due to metastasis. Conclusively, the incidence of patients with recurrence of metachronous multicentric occurrence was high, but the prognosis for these patients was significantly better than that for patients with recurrence due to metastasis.

Aged↗

Palmaz-Schatz stent for hepatic artery stenosis during hepatic arterial infusion chemotherapy.

Hepatic arterial infusion chemotherapy using an implantable port system was performed on a 40 year-old man with advanced hepatocellular carcinoma. When the in-dwelling catheter was inserted into the common hepatic artery (CHA), intimal dissection occurred as a result of the catheterization causing severe stenosis. On day 55 after intimal dissection, an in-dwelling Palmaz-Schatz stent was inserted after percutaneous transluminal angioplasty (PTA). CHA blood flow was shown to have improved on Digital subtraction angiography (DSA) and Doppler ultrasound after the in-dwelling Palmaz-Schatz stent. Thus a partial response was shown. The DSA from the implantable port system showed adequate patency 6 months after. This is the first report describing the usefulness of a Palmaz-Schatz stent for the severe stenosis of the CHA caused by the technique of catheterization.

Adult↗

Excision of papillary endocardial tumor.

We report the eighth case of surgical removal of a papillary endocardial tumor. The surgical approach was aided by intraoperative two-dimensional echocardiography. The tumor was attached to the chorda tendinea of the mitral valve and was successfully removed via a left atrial approach.

Adult↗

Late pathological changes of Carpentier-Edwards porcine bioprostheses in the mitral position.

Eighty-nine patients received mitral valve replacement with Carpentier-Edwards porcine bioprostheses between 1975 and 1983. Eighty-three patients (93.3%) were followed up after the operation; early death (within one month of operation) occurred in 6 patients and late death in 2 patients. After the operation, 64 survivors (85.3%), who did not require reoperation, exhibited improved symptoms according to the NYHA functional class. Of the 6 patients (6.7%) who required reoperation, 5 patients underwent reoperation 50 to 85 months after the implantation. Pathologically, all the removed valves showed degeneration of collagen and elastic fibers, no host endothelialization and mild to moderate infiltration of inflammatory cells. Thrombus in the left atrium was detected in one case. Destruction of the cusps was seen in three cases and calcification of the cusps developed in three cases. In general, the Carpentier-Edwards porcine bioprosthesis provided good clinical improvement over the periods studied. However, morphological changes of the bioprosthetic valve, such as destruction collagen and elastic fiber, and inflammatory cell infiltration of the cusps, seems to occur more frequently with the passage of time. We therefore suggest that patients with this prosthesis should be followed carefully, particularly at late intervals after implantation.

Adult↗