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Biomedical subjects

S Teramoto

Publications and source records attributed to S Teramoto.

At least 487 records · Page 27Linked to original sources

Teratogenic effects of combined administration of ethylenethiourea and nitrite in mice.

Teratogenic potential of ethylenethiourea (ETU) was investigated in SLC-ICR mice after its reaction with sodium nitrite. ETU was given orally in doses of 400 mg/kg on various days of pregnancy in combination with 200 mg/kg NaNO2 at varied intervals. When NaNO2 was given to females immediately after their treatment with ETU on day 6 or 8 of pregnancy, fetal survival was significantly decreased. Various types of malformations were observed in the living fetuses from mothers treated on day 6, 8, or 10 of pregnancy, but not on day 12. The teratogenicity disappeared when NaNO2 was given 2 h after the treatment with ETU.

Abnormalities, Drug-Induced↗

Myocardial protection of only the left coronary artery perfusion in patients with isolated aortic valve replacement.

Effectiveness of only left coronary perfusion on myocardial protection was assessed by measuring serially cardiac functions such as cardiac index (CI), stroke index (SI), left ventricular minute work index (LVWI) and left ventricular stroke work index (LVSWI) in 22 consecutive patients with isolated, scheduled aortic valve replacement. The cardiac functions were determined 2,4 and 6 hours after open heart surgery. Correlation coefficients(r) between coronary perfusion time and the cardiac functions were less than 0.23, such being statistically insignificant. SI and LVSWI were in statistically significant inverse correlation to the preoperative NYHA classification and extracorporeal circulation(ECC) time for 4 hours following open heart surgery, and CI and LVWI for 2 hours. The correlation coefficients were highest at the 2nd postoperative hour and then decreased with passage of time. Therefore, the cardiac dysfunctions occurring in the postoperative period correlated either to the preoperative NYHA classification or ECC time, or both. It does, however, seem likely that the dysfunctions were correlated to ECC time as the recovery time of 4 hours from the dysfunction is too short for preoperatively existing dysfunction. Therefore, it was concluded that the continuous perfusion of only the left coronary artery was not the determinant factor of the postoperative dysfunctions and that the ECC time afforded detrimental effects, although such continued for 4 hours in terms of SI and LVSWI, and 2 hours in term of CI and LVWI.

Adult↗

Dominant lethal mutation induced in male rats by 1,2-dibromo-3-chloropropane (DBCP).

1,2-Dibromoethane (DBE) and 1,2-dibromo-3-chloropropane (DBCP), soil fumigants, were investigated for their potential mutagenicity by dominant lethal studies in the rat and mouse. Dominant lethal mutation was induced by DBE in neither of the species. DBCP, on the other hand, induced dominant lethals in rats in the post-meiotic stage of spermatogenesis, especially in the early spermatid stage. However, DBCP did not cause dominant lethals in mice.

Animals↗

Factors influencing long-term survival after aortic valve replacement.

In the aortic stenosis group, the left ventricular (LV) muscle mass index was a good parameter for predicting the prognosis. Associated mitral valve disease had no influence on long term survival after aortic valve replacement. In the aortic insufficiency group, associated mitral valve disease had a marked influence on the results of aortic valve replacement. In general, the aortic insufficiency group had less clinical improvement postoperatively than the aortic stenosis group. In the annuloaortic ectasia group, left ventricular enddiastolic pressure (LVEDP) might be the predictor to the prognosis. This group had the worst prognosis, of the three groups. Early operation should be considered for patients who have no, or only mild symptoms of, aortic valve disease.

Adolescent↗

Anastomotic rupture of aortic grafts.

Proximal suture line disruption is one of the severe complications of synthetic vascular grafting for arteriosclerotic aortic disorders. The pathology of clinical and experimental cases revealed that a small bite of each stitch cut into the host aorta and became disrupted. Making each stitch as large as possible in the host aorta is the first procedural choice for aortic replacement surgery. Protecting the anastomotic line with a synthetic mesh cloth wrapping is preferable.

Adult↗

Relation of stroke and cardiac indices to serum catecholamines following open heart surgery.

Serum catecholamines (epinephrine, dopamine and norepinephrine) were measured two, four and six hours after open heart surgery. The ratios of stroke index (SI) and cardiac index (CI) to catecholamines (CA) were determined. Patients studied consisted of 27 with congenital and 14 with acquired heart disease. Extracorporeal circulation (ECC) time was longer than 90 minutes in 17 and shorter in 24 patients. SI and CI diminished in elder patients with congenital disease (Group Cg-ad), patients with acquired disease (Group Ac) and patients with a longer ECC time (Group L). Therefore, elder age and/or longer ECC time seems to be responsible to the lower indices. However, the ratios of the indices to CA showed that the lower indices indicated the poor response of the myocardium to CA in Group Ac and Group L. The response was larger in Group Cg-ad and the lower indices were related to lower serum CA level. It was concluded, therefore, that the indices of stroke volume and cardiac output had inverse correlation to ECC time, but not to age, namely, prolonged ECC compromised more severely the myocardium and resulted in the poor response of the myocardium to CA. Subsequently, to compensate for the poor response, serum CA levels were elevated probably to maintain due SI and CI in patients with prolonged ECC.

Adolescent↗

Induction of dominant-lethal mutations after administration of ethylenethiourea in combination with nitrite of the n-nitroso-ethylenethiourea in mice.

Mutagenic potentials of ethylenethiourea (ETU) in combination with sodium nitrite or of N-nitroso-ETU, a nitrosation product of ETU in vitro, were investigated in the mouse dominant-lethal test. Simultaneous 5-day p.o. administration of ETU (150 mg/kg) and sodium nitrite (50 mg/kg) caused a significant decrease in the percentage pregnancy and the number of implants in weeks 5 and 6 of testing, although no effects were obtained on these indices when the chemicals were applied separately. However, in the group treated with 30 mg ETU plus 10 mg sodium nitrite per kg no dominant-lethal mutations were induced. 5-day oral administration of 100 mg of N-nitroso-ETU per kg also exhibited similar effects to those observed after treatment with 150 mg ETU plus 50 mg sodium nitrite per kg.

Animals↗