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Biomedical subjects

S Komatsu

Publications and source records attributed to S Komatsu.

At least 271 records · Page 15Linked to original sources

Surgical treatment of aneurysms of the thoracic aorta with the aid of partial cardiopulmonary bypass: an analysis of 95 patients.

We retrospectively evaluated the surgical results in 95 patients with aneurysm of the thoracic aorta who were surgically treated using partial cardiopulmonary bypass (CPB) as an adjunctive method during the past 10 years. The cause of the aneurysm was atherosclerosis in 52% and dissection in 41%. Fifty-eight percent of the patients had an aneurysm of the entire descending thoracic aorta and 14 of these patients had a thoracoabdominal aneurysm. Emergency operation was performed in 16 patients (17%). There were 14 early deaths (14.7%) within one month after operation. Postoperative complications included renal dysfunction, partial paraplegia, and hemorrhage. Renal dysfunction occurred in 7 (7.8%) of the operative survivors; 2 of the 7 required hemodialysis. Partial paraplegia was observed in 2 patients undergoing total replacement of the thoracoabdominal aorta. Neither renal dysfunction nor paraplegia was related to the duration of aortic cross-clamping. Postoperative hemorrhage necessitating reopening of the chest occurred in 8 (8.9%) of the operative survivors. Partial CPB is useful in reducing the incidence of postoperative complications among patients undergoing aortic cross-clamping for a long period.

Aortic Dissection↗

A microplate method for isolation of viruses from infants and children with acute respiratory infections.

Between December 1984 and December 1986, a microplate technique was adopted for isolation of viruses from infants and children with acute respiratory infections. By using two kinds of tissue culture microplates, i.e., the HHVM plate, containing human embryonic fibroblast (HEF), HEp-2, Vero and MDCK cells, and the MK plate which contains secondary monkey kidney cells, 1,080 field viruses were isolated from 1,061 (24.9%) out of 4,254 throat swabs. Of these 1,080 isolates, 1,003 (92.9%) were recovered in the HHVM plates and the remaining 77 (7.1%) in the MK plates. With the HHVM plate, influenza A and B viruses were cultivated in MDCK, RS virus in HEp-2, parainfluenza and mumps viruses in Vero, adenoviruses in both HEF and HEp-2, polioviruses in HEF, HEp-2 and Vero, coxsackie B viruses in both HEp-2 and Vero, rhino and echo viruses in HEF, herpes simplex virus in both HEF and HEp-2, and cytomegalovirus in HEF, although MK were more sensitive than Vero to parainfluenza and coxsackie B viruses. There was no difference in the rate of isolation of viruses between the microplate and ordinary tube methods. Cross contamination in the microplates was negligible for routine work.

Acute Disease↗

Mutagenicity tests of the antithyroid agent thiamazole. Cytogenetic studies on male mice.

The mutagenic potential of thiamazole, an antithyroid agent, was investigated by an in vivo cytogenetic test and was compared with those of mitomycin C and vincristine. These drugs were subcutaneously injected into slc-ICR male mice either as a single dose or as multiple doses for 5 successive days. Thiamazole (90 or 180 mg/kg) did not increase the number of micronuclei in bone marrow cells. This drug also did not induce chromosomal aberrations in spermatogonium, spermatocyte, or bone marrow cells. On the other hand, mitomycin C (3.0 mg/kg) increased the appearance of chromosomal aberrations and micronuclei. Vincristine (0.2 mg/kg) induced bone marrow cells with a so called large micronucleus (d greater than or equal to D/4). These results suggest that thiamazole may not have significant effects on the genetic systems of mice.

Animals↗

Cytogenic analysis of dominant lethal effects of mitomycin C and ethyl methanesulfonate.

To gain further insight into the mechanism of induction of dominant lethal mutations, the relationship between chromosome aberrations in bone marrow and in male germ cells after treatment with mitomycin C (MMC) and ethyl methanesulfonate (EMS) was examined. In addition, we obtained fertilized eggs from the oviducts of crossbred female mice in the same way as in the dominant lethal mutation test, and examined chromosome aberrations in male pronuclei. MMC 2.5 and 5.0 mg/kg, EMS 175 and 350 mg/kg were given subcutaneously to slc-ICR mice. It was concluded that MMC causes a decrease in the sperm count by killing germ cells, which in turn causes an increase in the number of unfertilized eggs and preimplantation egg loss. MMC seems also to cause invisible damages in the chromosomes of spermatocytes which lead to dominant lethality. EMS induced chromosome damage in the post-meiotic germ cells, and this damage, in turn, produced chromosome aberrations in the eggs, resulting in a high incidence of dominant lethality.

Animals↗

Clinical evaluation of the Omniscience aortic disc valve prosthesis.

The clinical results and hemodynamics were evaluated in 100 cases of aortic valve replacement, using the Omniscience valve, in the period December 1980 through 1984. Late survival rate, clinical improvement and cardiac and prosthetic valve performance were acceptably satisfactory. The overall incidence of thromboembolism was 4.7%/patient year. The opening angle of the disc was less than 60 degrees in 18% of the studied cases. Further investigations are required to determine if such results were related to the valve structure or to some cause in the recipient. Assessment of the durability of the Ominiscience cardiac valve prosthesis must await the results of long-term observation.

Adolescent↗