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Biomedical subjects

N Toyoda

Publications and source records attributed to N Toyoda.

At least 127 records · Page 7Linked to original sources
PubMed1983

[Adipocyte insulin binding and glucose transport in normal pregnancy and streptozotocin-induced diabetic pregnancy in the rat: evidence for a postreceptor abnormality in insulin action].

To investigate the effect of pregnancy on the course of streptozotocin (STZ) induced diabetes, insulin binding to receptors and glucose transport activity were studied in isolated adipocytes from normal nonpregnant, normal pregnant, STZ-treated nonpregnant and STZ-treated pregnant rats. Experimental diabetes was induced by the administration of 40 mg/kg of STZ, and those exhibiting blood sugar concentrations between 150 and 250 mg/100 ml (198.8 +/- 6.4 mg/100 ml, mean +/- SEM) 7 days after treatment, were then used for the experiments as diabetic animals. Rats were mated at least 10 days after STZ administration. All studies were performed on gestational day 19. Fetuses of the diabetic mothers tended to be heavier than those of the control rats (2.49 +/- 0.31 vs. 2.38 +/- 0.22 g, mean +/- SD), but the difference was not statistically significant. Placental weights were significantly greater in the diabetics than in the controls (0.60 +/- 0.12 vs. 0.48 +/- 0.097 g, mean /+- SD, p less than 0.05). Insulin binding to receptors at an insulin concentration of 0.2 ng/ml was increased by 21% in the STZ-treated nonpregnant group as compared with the untreated non-pregnant group, by 32% in the STZ-treated pregnant group as compared with the untreated pregnant group due to increased receptor affinity without increasing the receptor number. However, no change in insulin binding was detected between the normal nonpregnant and normal pregnant, STZ-treated nonpregnant and STZ-treated pregnant groups. Glucose transport activity was decreased in adipocytes from the normal pregnant group as compared with that of the normal nonpregnant group. The effect was also observed between adipocytes from the sTZ-treated pregnant group and from the STZ-treated nonpregnant group. Adipocytes from rats belonging to either the normal pregnant group or the STZ-treated nonpregnant group showed a similar decrease in glucose transport activity, suggesting an equal effect of pregnancy and mild diabetes on glucose transport. Furthermore, adipocytes from the STZ-treated pregnant group showed the lowest transport activity of the four groups studied, suggesting an additive effect of pregnancy and diabetes on glucose transport activity. In conclusion, although insulin action in isolated adipocytes is reduced by pregnancy whether diabetes is induced or not, insulin binding to receptors is not changed by pregnancy. Thus, the effect on insulin action in adipocytes from diabetic rats as well as normal rats might lie at a site distal to the receptor. Insulin action in isolated adipocytes is reduced additively by pregnancy and diabetes.

Adipose Tissue↗
PubMed1983

[Erythrocyte insulin receptors from normal and diabetic pregnant women].

Insulin receptors on erythrocytes were studied in normal and diabetic pregnant women to clarify the mechanism of insulin resistance in pregnancy. The assays of insulin receptors were performed according to the method of Kobayashi, which is a slight modification of the method of Gambhir. 125I-insulin binding showed no significant differences between normal pregnant women during the first (n=18), the second (n=15) and the third (n=54) trimesters and nonpregnant controls (n=52). There were also no significant differences between the values before and after delivery (n=8). Reticulocyte counts significantly increased in pregnant women during the second trimester and during the later periods. There was a positive correlation between 125I-insulin binding and reticulocyte counts in late pregnancy. These findings suggest that reticulocyte counts should always be considered in estimating erythrocyte insulin receptors in pregnancy. Then, insulin binding in late pregnant women with reticulocyte counts below 10% (n=20) was studied. The value was slightly decreased as compared to that in the nonpregnant controls, but difference was not significant. 125I-insulin binding in gestational diabetes (n=6) was decreased, but that in overt diabetes (n=4) was not. Patients with overt diabetes had been receiving insulin therapy. Insulin resistance in normal pregnancy cannot be explained by the changes of insulin receptors from this study. It may be due to some post-receptor abnormalities. But decreased insulin binding might be one of the factors that manifest or deteriorate gestational diabetes.

Erythrocytes↗
PubMed1982

Insulin receptors on erythrocytes in normal and obese pregnant women: comparisons to those in nonpregnant women during the follicular and luteal phases.

Insulin receptors on erythrocytes were studied in nonpregnant women (n = 14) during the follicular and luteal phases, and in pregnant women in the third trimester with normal body weight (n = 14), with weight gain over 14 kg during pregnancy (n = 7), and with obesity before pregnancy (n = 7). Women with increased reticulocytes in the blood were excluded from this study. Insulin binding was slightly decreased in nonpregnant women during the luteal phase, as compared with the binding during the follicular phase. Insulin binding in normal pregnant women was comparable to that in nonpregnant women during the luteal phase. The number of receptors was reduced in those women who gained an excessive amount of body weight during pregnancy or in those pregnant women who were previously obese. These results suggest that an increased insulin resistance during pregnancy, compared to the luteal phase in nonpregnant women, cannot be explained by the changes in insulin receptors but that the reduction in insulin receptors might be one of the causes of the deterioration in carbohydrate metabolism in obese women in late pregnancy.

Erythrocytes↗
PubMed1981

[Effect of pregnancy on hemoglobin A1 in normal and diabetic women (author's transl)].

Hemoglobin A1, a normal minor variant of adult HbA in which the N-terminal valine of the beta chain is glycosylated by a Schiff base. The increased levels of HbA1 in diabetic subjects have been correlated with various indicators of diabetic control during preceding weeks, suggesting that HbA1 measurement is an index of long term blood-glucose control. Considerable attention is now paid to diabetic control during pregnancy because maternal hyperglycemia is believed to be partly responsible for increased prevalence of fetal morbidity and mortality. HbA1 was assayed during pregnancy with the Helena glycosylated hemoglobin quik column kit using an ion exchange resin. 1. HbA1 correlated with HbA1c during pregnancy, r = 0.834, p less than 0.001. 2. HbA1 did not alter during pregnancy as compared to the non-pregnant group, 7.26 +/- 0.85% vs 7.09 +/- 0.60%. 3. There was no relationship between HbA1 and hemoglobin. 4. A significant direct relationship was not found for HbA1 and the infant weight. 5. The diabetic group had elevated levels of HbA1 to the normal group but gradually decreased to normal levels after a rigid control was achieved. 6. None of pregnant diabetics whose HbA1 was normal on presentation gave large baby for gestational age. It is speculated that these fluctuation in HbA1 are most likely due to changes in long-term blood glucose control. HbA should decline to reach a constant, low level as soon as possible in diabetic pregnancy. This tool should add in management of diabetic pregnancy to improve the outcome of pregnancy.

Birth Weight↗
PubMed1978

Fine structure of connectin nets in cardiac myofibrils.

A net-like structure extending through Z lines of myofibrils in frog cardiac muscle was clearly demonstrated under an electron microscope after the removal of myosin and actin. The diameter of the very thin filaments forming the nets was approximately 2 nm; this width was thinner than that of the actin filament. The net structure is ascribed to connectin, an elastic protein of muscle.

Actins↗
PubMed1976

Triple isotope scintiphotography for differentiating between renal cysts and renal tumors.

As a routine diagnostic approach to patients who present hematuria or abnormal findings in X-ray films such as intravenous pyelograms, the cases are submitted to serial scintiphotography every two minutes after the intravenous administration of 250 muCi of 131I-Hippuran and to renography with PHO/GAMMA Scintillation Camera (Nuclear-Chicago). When scintiphotography with 131I-Hippuran reveals filling defect in the kidney region, scintiphotography with 150 muCi of 203Hg-chlormerodrin and renal blood flow scintiphotography after antecubital intravenous injection of 10 mCi of 99mTc are carried out. The present report concerns 8 cases of renal tumor and 5 cases of renal cyst confirmed by X-ray examination and surgical operation. The scintiphotography revealed decreased uptake of 131I-Hippuran and 203Hg-chlormerodrin in both tumor and cyst sites, exhibiting round or band-shaped filling defects. On the other hand, renal blood flow scintiphotography with 99mTc demonstrated the cyst as a filling defect but failed to visualize most of tumors. Accordingly, these techniques are available for differential diagnosis of the two lesions.

Adult↗
PubMedDate not supplied

Adenocarcinoma of mammary-like glands in the vulva successfully treated by weekly paclitaxel.

An 87-year-old was referred for gynecologic evaluation of a lesion involving the left labia majus noted 3 years earlier. Fine-needle aspiration cytology revealed clusters with an acinous structure or glandular formation. The tumor appeared as cell clusters with linear arrangements. Histologic examination showed the same morphologic findings as scirrhus type of primary breast carcinoma. Examinations of the breasts and axillary lymph nodes were normal. This disease was diagnosed as an adenocarcinoma arising in mammary-like glands of the vulva. Bone scan showed multiple foci in the sternum, costa, and vertebrae, consistent with metastatic disease. We administered five courses of weekly paclitaxel chemotherapy, which achieved a partial response. There were no severe adverse effects. In our case, the fine-needle aspiration cytology was a rapid and minimally invasive method of diagnosis, and the findings were extremely similar to those of the scirrhus type of primary breast carcinoma. Rapid and accurate diagnosis made with this technique might contribute to a good prognosis in the early-staged cases. Weekly paclitaxel chemotherapy may be one of the safe and effective treatments for this disease with distant metastases, even in extremely aged patients (over 80 years).

Adenocarcinoma↗
PubMedDate not supplied

Aspiration of giant hepatic cyst in the fetus in utero.

A large hepatic cyst was diagnosed in a fetus at 29 weeks of gestation by puncture and aspiration performed under ultrasonographic guidance. This procedure was repeated five times at about 2-week intervals, with a total of 1,446 ml of cystic fluid aspirated. A healthy female infant was delivered vaginally at 40 weeks of gestation. Her Apgar score was 9 at 1 min, and she weighed 2,790 g. On the 14th postnatal day, the hepatic cyst was punctured percutaneously under ultrasonographic guidance, and 119 ml of yellow fluid was aspirated. The cyst was subsequently not visible on computed tomography at 9 months. Surgery was not indicated in this infant, and the cyst was also not detected at the age of 21 month. Thus, treatment in utero appeared to have obviated the need for surgery.

Adult↗
PubMedDate not supplied

Identification of a high-risk subgroup in cytology-positive stage IIIA endometrial cancer.

OBJECTIVE: To identify a high-risk subgroup among patients with cytology-positive stage IIIA endometrial cancer. STUDY DESIGN: Fifty-four stage IIIA endometrial cancer patients who were positive only on peritoneal cytology were divided into two groups based on the cytologic pattern of their peritoneal smears. In group A, malignant cell clusters had well-defined edges, while the tumor cell clusters had scalloped edges in group B. The prognostic significance of these findings was investigated. RESULTS: The five-year disease-free survival rate was 97.5% in group A (n=40) versus 50% in group B (n = 14). Multivariate analysis confirmed that the cytologic pattern had an independent influence on survival. CONCLUSION: Positive peritoneal cytology composed of malignant cell clusters with well-defined edges has no impact on survival. Only endometrial cancer patients who show tumor cell clusters with scalloped edges in peritoneal smears are worth considering for upstaging.

Adenocarcinoma↗