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Biomedical subjects

A Hidaka

Publications and source records attributed to A Hidaka.

84 records · Page 5Linked to original sources
PubMed1987

[Effects of uterine contraction and a beta-stimulant on placental and fetal brain blood flow in correlation with fetal heart rate changes].

The effects of uterine contraction on placental and fetal brain blood flow in correlation with fetal heart rate change and also beta-stimulant on placental and fetal brain blood flow during late deceleration were studied in late pregnant rabbits. We determined the fetal heart rate (FHR) and placental and fetal brain blood flow by a thermocouple method under urethane anesthesia. Fetuses exposed to a more than 30% decrease in placental blood flow by uterine contraction developed more than 20% bradycardia and also a significant decrease in fetal brain blood flow. There are a significant relationship between the decrease in FHR and fetal brain blood flow. beta-stimulant administered to the mother suffering from already severely hypoxic fetal bradycardia increased FHR in accordance with the increase in the placental blood flow and moreover there was recovery from decreased fetal brain blood flow.

Adrenergic beta-Agonists↗
PubMed1986

Serum CA 19-9 concentrations and computed tomography findings in patients with pancreatic carcinoma.

Carbohydrate antigen (CA) 19-9 is a new tumor marker, defined by a monoclonal antibody. Serum CA 19-9 concentrations and computed tomography (CT) findings were studied in 55 patients with histologically proven adenocarcinoma, and in 22 patients with chronic pancreatitis. CA 19-9 was useful in 83% of cases for the differential diagnosis between pancreatic carcinoma and chronic pancreatitis, and serum CA 19-9 levels in pancreatic carcinoma were highly related to the size of tumors. Serum CA 19-9 levels greater than 37 U/ml were seen in patients with a tumor of less than 3 cm, 3 to 5 cm, and greater than 5 cm in diameter 13% (1/8), 90% (19/21), and 92% (24/26) of cases, respectively. Tumor location, however, was unrelated to serum CA 19-9 value. These results indicated that the measurement of serum CA 19-9 concentrations would be useful in most, if not all, cases for the differential diagnosis between pancreatic carcinoma and chronic pancreatitis, and for the evaluation of tumor burden in patients with pancreatic carcinoma.

Antigens, Neoplasm↗
PubMed1986

Experimental study on the hemodynamics of the neonatal brain.

The effects of inhalation of different gases were studied in neonatal rabbits with the following results: In neonates with normal heart rate (HR), hyperoxia induced by O2 inhalation did not appreciably affect HR, but it increased cerebral tissue PO2, while decreasing cerebral blood flow (CBF). In many of those which fell into a state of marked bradycardia, not only HR and CBF but also cerebral tissue PO2 levels were recovered as a result of O2 inhalation. CBF was increased even when HR was hardly changed (at least when the HR decrease was 10% or less) by hypercarbia due to inhalation of CO2 mixed air. Severe hyperoxia induced by N2O inhalation caused bradycardia and reduced CBF.

Animals↗
PubMed1986

Influence of the increased uterine tonus on maternal hemodynamics.

In an experiment using 103 late pregnant rabbits, the resting uterine tonus was increased by inserting a balloon into the amniotic cavity on the cervical side (n = 71) or the ovarian side (n = 52) and the effects of this increase on the maternal blood pressure, renal cortical blood flow (measured by a thermocouple method), renal arterial and carotid arterial blood flow (measured with an electromagnetic flowmeter) were studied. The findings are briefly described, as follows: The maternal blood pressure was slightly increased on both sides (by 12.0 +/- 3.5% on the cervical and by 12.0 +/- 3.8% on the ovarian side). However, there was a hemodynamic difference between the renal cortical and renal arterial blood flow on the cervical side and those on the ovarian side: They were slightly increased on the cervical side and slightly decreased on the ovarian side. On the basis of these findings, the following may be proposed: An increase in resting uterine tonus causes a rise in maternal blood pressure associated with blood redistribution from the uteroplacental vascular bed. However, the fact that the renal blood flow was decreased consequently upon the increase in resting uterine tonus raised a possibility of neurotransmission via the ovarian plexus as well as utero-renal reflex.

Animals↗
PubMed1986

Influence of maternal hyperoxia or hypercarbia on the hemodynamics of the placenta and fetal brain.

Pregnant rabbits were subjected to inhalation of different gases, and the changes in placental blood flow (PBF), fetal heart rate (HR), and fetal cerebral blood flow (CBF) associated with the changes in maternal blood gas levels were studied. The results are given below. In maternal hyperoxia, maternal blood pressure (BP) was not much influenced and PBF remained unchanged or was slightly decreased when the PCO2 level was not varied or when it was lowered. In contrast, not only maternal BP but also PBF was increased when the PCO2 level was elevated. In the absence of a conspicuous increase in PCO2, neither fetal HR nor CBF varied, regardless of PBF. Both maternal BP and PBF were increased in mild to moderate maternal hypoxia (PO2 greater than 40 mmHg) and decreased in severe hypoxia (PO2 less than 30 mmHg). The decreasing trend of fetal HR or CBF was strengthened as maternal hypoxia was intensified. An obvious decrease in either parameter was observed in severe maternal hypoxia (PO2 less than 30 mmHg). Fetal HR and CBF were well maintained. in hypoxic dams with increased PBF as compared with those with unchanged or decreased PBF. The higher the PCO2 level or the lower the pH value, the more was fetal bradycardia that was apt to occur, even in a mildly hypoxic state.

Administration, Inhalation↗
PubMed1981

[Relationship between intrauterine pressure and maternal hemodynamics (author's transl)].

Placental and renal cortical blood flow were measured by thermocouple method in 70 cases of late pregnant rabbits, 17 late pregnant dogs and 2 late pregnant monkeys. Intrauterine resting tonus in 148 primigravid and 74 multigravid women tended to increase towards the onset of labor, with maternal mean blood pressure elevating in close relation to the intrauterine pressure. Especially in primigravid women there was a strong tendency and intrauterine resting tonus was higher value in primigravidas than that in multigravidas. The increasing of intrauterine pressure by uterine contraction caused an elevation of maternal blood pressure by about 10% in pregnant women, and caused a decrease of placental blood flow by about 30% respectively, but it did not show any definite pattern in renal cortical blood flow in experimental animals. On the other hand, the increasing of intrauterine resting tonus with intraamniotic saline injection in 47 cases of experimental animals brought about a decrease of placental blood flow by about 30%, at the same time caused a decrease of renal cortical blood flow by about 20% and an elevation of maternal blood pressure by about 10% respectively. These findings support the concept that increasing of uterine resting tonus could play a role in mediating late pregnancy induced hypertension.

Animals↗