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Biomedical subjects

M Aota

Publications and source records attributed to M Aota.

24 records · Page 2Linked to original sources
PubMedDate not supplied

Hepatic circulation during nonpulsatile cardiopulmonary bypass.

The arterial ketone body ratio, which reflects the hepatic mitochondrial redox potential (NAD+/NADH), decreases markedly during cardiopulmonary bypass (CPB). One of the reasons for arterial ketone body ratio reduction may be hepatic hypoperfusion during CPB. To evaluate the hepatic circulation under nonpulsatile CPB, the authors used color Doppler ultrasonography to measure the portal venous flow (PVF) in 24 adult patients before, during (aortic clamping and rewarming period), and after CPB. Nonpulsatile hypothermic CPB was performed at a flow rate of 2.4 L/min/m2. PVF was calculated from the product of mean flow velocity and cross-sectional area of the portal vein. PVF was maintained during CPB at 0.44 +/- 0.13 and at 0.54 +/- 0.18 L/min/m2. PVF (%) in relation to systemic blood flow was obtained by calculating PVF/CI or PVF/PI, where CI is the cardiac index and PI is the perfusion index. PVF (%) before, during, and after CPB was 18.3 +/- 9.3, 18.5 +/- 5.5, and 17.4 +/- 6.7%, respectively. In conclusion, PVF was maintained during nonpulsatile CPB at a flow rate of 2.4 L/min/m2 and depended upon systemic blood flow.

Adult↗
PubMedDate not supplied

Antitumor effect of biological response modifier, PSK, on C57BL/6 mice with syngeneic melanoma B16 and its mode of action.

The effects of PSK, a protein-bound polysaccharide, on the survival period and effector cell activity were examined using C57BL/6 mice with melanoma B16. PSK prolonged the survival period of the mice with tumors in a schedule- and dose-dependent manner. However, no life-prolonging effect was observed when carrageenan-treated mice or congenitally athymic mice were used as hosts. PSK enhanced the cytostatic activity and interleukin-1-producing capacity of peritoneal exudate plastic-adherent cells in C57BL/6 mice with tumors. These findings suggested that PSK prolongs the survival period of mice with B16 tumors through T-cell- and macrophage-dependent mechanisms.

Animals↗
PubMedDate not supplied

The proper use of glue: a 20-year experience with the GRF glue in acute aortic dissection.

BACKGROUND: In 1977, the use of Gelatine-Resorcine-Formaline (GRF) biological glue during surgery of acute Type A aortic dissection was proposed. The present study retrospectively analyzes the late results obtained with this adjunct in an experience extending over a twenty-year period of time. PATIENTS AND METHODS: From January 1977 to March 1996, 171 patients (124 males and 47 females) aged from 15-79 years (mean age: 53 +/- 14 years) underwent an emergency operation for type A aortic dissection in our institution. All patients suffered from acute type A dissection and 144 (84%) were operated on within 48 hours after the onset of symptoms. Twenty-six patients (15.2%) had Marfan's syndrome. The ascending aorta was replaced in all patients and the aortic stumps were reinforced with the GRF glue. In 39 patients (23%), the aortic valve was replaced either independently (5 cases, 3%) or by means of a composite graft (34 cases, 19.8%). Because of the location of the intimal tear, the aortic replacement was extended to the transverse arch in 58 patients (33.9%). RESULTS: Hospital mortality amounts to 21% (36 patients), 22.8% in patients with arch replacement and 21.1% in patients without arch replacement (n.s). One hundred thirty-five patients were discharged and surveyed from 2 months to 19 years postoperatively (cumulative follow-up: 856 patients/years. Mean follow-up: 79 +/- 66 months). During this period of time, 22 patients (16.1%) had to be reoperated on for a total of 28 reoperations. Six of those (27.2%) died at reoperation. At univariate analysis, presence of Marfan's syndrome (p < 0.05) and absence of arch replacement (p < 0.02) were determinant risk factors for reoperation. Emergency (p < 0.01) and thoracoabdominal replacement (p < 0.04) were determinant risk factors of death at reoperation. The acturial freedom from reoperation (Kaplan-Meier, CI: 95%) is: 96.08% (90.9-98.2), 87.6% (79.8-92.7), 80.9% (70.8-86.1), 66.4% (51.1-78.9) at 1, 5, 10, and 15 years respectively. A total of 36 patients (27.7%) died during follow-up. Presence of Marfan's syndrome (p < 0.01), reoperation (p < 0.02), stroke (p < 0.05), cardiac failure (p < 0.05) were determinant risk factors of late mortality. The actuarial late survival rate (K-M. C.I.: 95%), including hospital mortality, is: 71.5% (64.3-77.8), 66% (58.3-73), 56.4% (47.7-64.7), 46.3% (36.4-56.5) at 1, 10 and 15 years. CONCLUSIONS: The GRF glue has proved to be extremely useful during emergency initial surgery for acute type A dissection, making the procedure much easier and safer. Through this operative improvement, the use of the GRF glue seems to have a beneficial influence on the late results which however, depend mainly on the patient's basic condition.

Actuarial Analysis↗