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Biomedical subjects

S Aoki

Publications and source records attributed to S Aoki.

At least 523 records · Page 29Linked to original sources
PubMed1987

Determination of butyltin and phenyltin compounds in biological and sediment samples by electron-capture gas chromatography.

A method is described for the gas chromatographic determination of nanogram amounts of mono-, di- and tributyltin compounds and mono-, di- and triphenyltin compounds in biological and sediment samples. These compounds are converted into the corresponding chlorides with hydrochloric acid, extracted with ethyl acetate and hydrogenated with sodium tetrahydroborate. The corresponding hydrides, mono-n-butyltin hydride, di-n-butyltin hydride, tri-n-butyltin hydride, monophenyltin hydride, diphenyltin hydride triphenyltin hydride, are detected by electron-capture gas chromatography after clean-up by silica gel column chromatography. The detection limits are 10-20 ng/g for mono-n-butyltin chloride, 0.5-1 ng/g for di-n-butyltin chloride, 1-2 ng/g for tri-n-butyltin chloride and diphenyltin chloride and 2.5-5 ng/g for monophenyltin chloride and triphenyltin chloride, in biological and sediment samples.

Animals↗
PubMed1987

Sulpiride injection into the dorsal striatum increases methamphetamine-induced gnawing in rats.

Sulpiride injected into the dorsal striatum enhanced both methamphetamine- and apomorphine-induced gnawing but blocked both when injected into the ventral striatum. The hyperlocomotion produced by methamphetamine was reduced by sulpiride injected into the dorsal striatum. The DA, DOPAC and HVA concentrations in the ventral striatum were increased 60 min after the injection of sulpiride into the dorsal striatum. Possible reasons for the enhancement of methamphetamine-induced gnawing by sulpiride injected into the dorsal striatum are discussed.

Animals↗
PubMed1987

Renal arterial blood flow velocity waveforms in pregnant women.

Seventy-two continuous-wave Doppler ultrasonographic examinations were performed on nine nonpregnant and 56 normal pregnant women. The range of gestation was 6 to 40 weeks, and the objective was to record the renal arterial blood flow velocity waveform. Acceleration time and systolic per diastolic ratio of renal arterial blood flow velocity waveforms were assessed. Of 72 examinations, 68 recordings were made of the left renal artery (94.4%) and 28 of the right renal artery (38.9%), respectively. There was no correlation between acceleration time and systolic per diastolic ratio and gestational age, respectively, and no correlation between acceleration time and systolic per diastolic ratio, and caliceal diameter of the renal pelvis, respectively. Acceleration times of the left and right renal arteries were 47 +/- 11 and 40 +/- 8 msec in nonpregnant women and 62 +/- 23 and 62 +/- 23 msec in pregnant women, respectively. The left and right systolic per diastolic ratios were 3.1 +/- 0.7 and 2.9 +/- 0.5 in nonpregnant women and 2.8 +/- 0.6 and 2.6 +/- 0.5 in pregnant women, respectively. Therefore these data provide a foundation for the study of hydronephrosis, which may occur in pregnant women.

Blood Flow Velocity↗
PubMed1987

Induction of petite mutation with acriflavine and elevated temperature in Candida albicans.

A method of inducing respiratory deficient (petite) mutation in Candida albicans (which has been previously classed as a petite-negative yeast) and characteristics of some isolated mutants are reported. When grown at 42 degrees C in the presence of a cytoplasmic mutagen (acriflavine), C. albicans exhibited diauxie-like biphasic growth. Mutants which were unable to grow on a non-fermentable substrate, glycerol, were isolated from the above culture at a frequency of less than 1%. The simultaneous action of both acriflavine and a supraoptimal temperature of 42 degrees C was required to induce respiratory mutation. The respiratory mutants were separated into two groups: i. mutants exhibiting a complete cytochrome spectrum but with low respiratory activity and ii. those deficient in cytochrome aa3. Further characterization of their respiratory activity, colony morphology, mitochondrial morphology and growth manner supported the evidence that members of the latter group can be regarded as petite mutants.

Acriflavine↗
PubMed1987

Ultrasonographic assessment of fetal adrenal gland and placenta: correlation with estrogen in maternal urine.

Forty-eight ultrasonographic examinations done to assess growth of the fetal adrenal gland and placental aging were performed on 17 normal fetuses and 7 fetuses with intrauterine growth retardation (IUGR). Gestational age ranged from 30 to 40 weeks. High correlations of the area of fetal adrenal gland (FAGA) with gestational age were noted in the normal fetuses (r = 0.96, p less than 0.001) and IUGR (r = 0.93, p less than 0.001), respectively. FAGA correlated well with the level of estrogens in the maternal urine (r = 0.65, p less than 0.001). When the value of FAGA was 300 mm2 and over, the level of estrogens in the maternal urine was 20 mg/day and over, and all were normal fetuses. In cases of grade I and II placentas, the mean values of FAGA in normal fetuses were larger than those in IUGR, respectively (p less than 0.001). In the case of IUGR with placental infarction and hematoma associated with severe toxemia of pregnancy, the FAGA was significantly small.

Adrenal Glands↗
PubMed1987

Ultrasonographic measurement of the human fetal liver in utero.

A total of 232 measurements of the size of the human fetal liver were made from 19 weeks gestation through to term. The size of the liver increased linearly with the advance in pregnancy. Statistical analyses showed a highly significant correlation between liver circumference and area and gestational week or fetal abdominal circumference (r = 0.89, r = 0.90, r = 0.90, r = 0.85).

Abdomen↗
PubMed1987

Ultrasonographic identification of the human fetal gallbladder in utero.

Ultrasonographic studies of the human fetal gallbladder were performed in utero on 149 fetuses ranging from 20 to 39 weeks of gestation. The gallbladder could be identified in 37.5% (20-23 weeks) to 64.7% (24-27 weeks) after 20 weeks of gestation. The normal sonographic characteristics of the fetal gallbladder were described and the area of fetal gallbladder, the length and the width were measured, respectively. The ultrasonographic identification of the fetal gallbladder is a first step in antenatal detection of congenital anomalies affecting the gallbladder.

Female↗
PubMed1987

Ultrasonographic in utero identification and measurement of the normal fetal spleen.

Sixty-nine ultrasonographic examinations were performed to identify and measure the fetal spleen in utero on 49 women with regular menstrual cycles, at 18-41 weeks of gestation. The length (FS-L), width (FS-W), area (FS-A), and sectional area (length X width; FS-LW) of the fetal spleen correlated well with the gestational age. A very high correlation of FS-LW with FS-A was noted (r = 0.98; p less than 0.001). Ultrasonographic identification and measurement of the fetal spleen in utero is thus a useful indicator of fetal spleen growth and should facilitate detection of in utero splenomegaly, asplenia and other abnormalities.

Female↗
PubMed1987

Monitoring of dopamine metabolism by in vivo voltammetry and high performance liquid chromatography in L-dopa-treated rats.

Following L-DOPA administration, DA metabolites were measured by both in vivo voltammetry and HPLC-ECD. In vivo, the amplitudes of the catechol oxidation currents in both the striatum and frontal cortex increased and reached a plateau from 60 min to 240 min after L-DOPA treatment. L-DOPA, DA, DOPAC and HVA levels measured by HPLC-ECD after L-DOPA treatment were increased in both regions, and the occurrence of the peak of each compound was dependent on its order in the metabolic pathway, i.e., 15 min for DA, 45 min for DOPAC and 60-180 min for HVA. However, NE remained unchanged. No indication of a rapid DA increase was apparent in the catechol oxidation current at 15 min; and thus, DA is unlikely to be a main contributor to the catechol oxidation current in the brain of rats treated with L-DOPA.

3,4-Dihydroxyphenylacetic Acid↗