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Biomedical subjects

T Aoki

Publications and source records attributed to T Aoki.

At least 955 records · Page 53Linked to original sources
PubMed1988

[Studies on estrogen replacement therapy with conjugated estrogens by histological evaluation of the endometrium of 205 women].

205 postmenopausal women, who received 0.625mg of conjugated equine estrogen (CEE) daily for 2-12 years, were evaluated by endometrial histopathology in three treatment schedules. Group I received CEE for 3 weeks followed by a pause for 1 week in each course. Group II took norethindrone, 10mg daily for 1 week, between CEE and the one week pause. Group III received CEE on calendar days 1 to 21 and norethindrone, 10mg daily, together from day 15 to day 21, and no drug from day 22 every month. The endometrial biopsy was done before and 3 months after the start of the treatment, and every twelve months thereafter. In Group I (73 cases, 4,327 courses), 2 cystic hyperplasias and 8 adenomatous hyperplasias, and in Group II (70 cases, 3,936 courses), 2 cystic hyperplasias, 14 adenomatous hyperplasias, and 2 atypical hyperplasias were developed. In contrast, in Group III (62 cases, 2,765 courses), only 2 adenomatous hyperplasias appeared. Accordingly the incidence of endometrial hyperplasia was 1 for 433, 219, and 1,383 courses respectively. These hyperplasias rapidly disappeared after the cessation of estrogen administration. No endometrial carcinomas were detected throughout the treatment. From these results the treatment schedule for Group III was judged to be superior to the others.

Adult↗
PubMed1988

Acivicin inhibits Crithidia fasciculata growth in a serum-free medium and inactivates carbamoyl-phosphate synthetase II in vivo.

1. Crithidia fasciculata was grown in a serum-free medium. 2. Twenty-six hours after addition of 2, 5, 20, 50, and 150 microM acivicin to logarithmically growing organisms, cell counts were decreased to 46, 23, 14, 9.1, and 8.6% of the control, respectively. 3. Guanosine plus cytidine (0.1 mM each) provided complete protection against growth inhibition by 5 microM acivicin. 4. Cells exposed to 10 microM acivicin showed a time-dependent, irreversible inactivation of L-glutamine-dependent carbamoyl-phosphate synthetase II activity; ammonia-dependent synthetase II activity was increased up to 34% of the control. 5. Glutamine (20 mM) protected the enzyme from inactivation in vivo. 6. These results indicate that acivicin acts as an affinity analog of L-glutamine in vivo as it does in vitro.

Animals↗
PubMed1988

Drug-resistant plasmids from fish pathogens.

The epidemiological surveillance of drug-resistant strains of the fish pathogenic bacteria Vibrio anguillarum and Pasteurella piscicida carrying transferable R plasmids in fish farms is described. The DNA structure of R plasmids, and the drug-resistant determinants of R plasmids from the fish pathogens Aeromonas hydrophila,aeromonas salmonicida, Edwardsiella tarda, V. anguillarum, and P. piscicida are discussed.

Animals↗
PubMed1988

[Echocardiographic findings in a case of Fabry's disease with aortic regurgitation and complete AV block, and in his family members].

A 46-year-old man with Fabry's disease having aortic regurgitation and complete atrioventricular (AV) block was presented. In spite of severe aortic regurgitation (Seller's grade 3/4), his two-dimensional (2-D) echocardiogram revealed increased thickness of the left ventricular wall with mild dilatation. The myocardial echo showed a fine granular sparkling texture suggesting phospholipid deposition in the myocardial tissue. The membranous portion of the interventricular septum was thickened, and the aortic valve was thickened and had imperfect coaptation. Endomyocardial biopsy of the right side of the interventricular septum revealed intramyocardial vacuolization by light microscopy. Electron microscopy confirmed the presence of myelinoid lamellar inclusion. Electrophysiologic examination revealed an intra-Hissian AV block. A DDD pacemaker was implanted and the patient's symptoms were improved. Valvular replacement was not attempted due to the danger of suture failure. The patient's brother (41-year-old) also had increased thickness of his left ventricular wall on echocardiography, and a complete AV block by ECG, but no valvular abnormalities. His sister (45-year-old) had increased thickness of the left ventricular wall on echocardiography, and negative T waves by ECG, but she had no cardiac symptoms. The possibility of cardiac involvement in this heterozygous woman with Fabry's disease should also be considered. The patient's 38-year-old sister and all the children of all family members had normal left ventricular wall thicknesses and normal ECG. These findings may correspond to the age-related disease severity. The possibility of cardiac abnormalities should be considered in heterozygous women with Fabry's disease.

Adult↗
PubMed1988

[A successful treatment of giant carotid artery aneurysm by a detachable balloon technic; a child case].

For the treatment of unclippable giant carotid artery aneurysms, proximal occlusion of the carotid artery is still an accepted treatment by surgical ligation, Selverstone clamp, or detachable balloon. However, proximal artery occlusion should be avoided as far as possible. Use of detachable balloons for proximal artery occlusion in the treatment of giant intracranial aneurysm in children has been reported by several authors, but no report of successfully treated cases of occlusion of the aneurysm without occlusion of the parent artery can be found. On January 1st, 1987, a-5-year old girl was admitted to our clinic with chief complaints of exophthalmos and loss of vision in her left eye. On admission, neurological examination showed palsies of the left oculomotor and abducens nerve and left internal carotid angiogram visualized a giant aneurysm in the cavernous portion. A balloon catheter procedure was carried out under general anesthesia using an intra-arterial catheter technique. A No. 9 French introducer catheter was placed through the femoral artery sheath. No filling of aneurysm without occlusion of the parent artery could be confirmed by angiogram. No. 12 Debrun detachable balloon was then detached. Postoperative course was uneventful. Subsequently, her oculomotor and abducens nerve palsies disappeared. Digital subtraction angiography taken about three months after the procedure showed complete occlusion of the aneurysm. The authors emphasized that the occlusion of the aneurysm using a detachable balloon was also the ideal method for the treatment of the children's giant aneurysm.

Carotid Artery Diseases↗
PubMed1988

[First pass effect by infusing 99mTc-human serum albumin into the hepatic artery].

The fundamental principles of intra-arterial infusion chemotherapy are thought to be increased local drug concentration and the "first-pass" effect. The concentration in the rest of the body can only be decreased if there is local elimination of the infused drug before reaching the systemic circulation. This is referred to as the "first-pass" effect. In the evaluation of "first-pass" effect, the uptake of liver after infusing 99mTc-human serum albumin (99mTc-HSA) in the hepatic artery by injecting the subcutaneously implanted silicon reservoir was compared with that obtained after intravenous administration of 99mTc-HSA. In order to remove the factor of portal infusion, each count of liver up take had been continued for only 24 seconds after starting the liver uptake. The results are as follows: for 24 cases excepting 6 cases with catheter obstruction, the mean i.a./i.v. ratio was 7.92 +/- 3.34 (range 3.25 to 17.25). Although the elimination rate of drugs in the liver varies with each drug, the infusion of intraarterial chemotherapy should be about 8 times more concentrative than intravenous administration on the "first-pass" effect.

Heart↗
PubMed1987

Acute monocytic leukemia in children. Response to VP-16-213 as a single agent.

Three patients were studied: two infants with acute monocytic leukemia who failed to respond to the initial combination therapy of daunorubicin with cytosine arabinoside, and an adolescent with relapsed acute monocytic leukemia. They were intensively treated with epipodophyllotoxin (VP-16-213) alone and subsequently had complete remission. One patient showed apparently dose-dependent cytotoxic effect. All three patients have maintained complete remission for 6, 7, and 11 months, respectively. Toxicities, including myelosuppression, alopecia, nausea, vomiting, and renal dysfunction, were well tolerated. Intensive treatment with VP-16-213 alone was thus found to have a potent therapeutic effect on acute monocytic leukemia in children. VP-16-213 deserves a further assessment in the therapeutic protocol for patients with childhood acute monocytic leukemia.

Adolescent↗
PubMed1987

Caseins are cross-linked through their ester phosphate groups by colloidal calcium phosphate.

Artificial casein micelles were prepared by adding 30 mM calcium, 22 mM phosphate and 10 mM citrate to sodium caseinate solutions, and the content of the casein aggregates cross-linked by colloidal calcium phosphate was determined by high-performance gel chromatography on a TSK-GEL G4000SW column in the presence of 6 M urea. The content of the casein aggregates cross-linked by colloidal calcium phosphate in artificial whole casein micelles was 48% of total casein, and their relative casein composition determined by high-performance ion-exchange chromatography was 53.1% for alpha s1-casein, 15.8% for alpha s2-casein, 31.1% for beta-casein and 0% for kappa-casein. The order of cross-linking by colloidal calcium phosphate agreed with that of the ester phosphate content of casein constituents. The content of the casein aggregates cross-linked by colloidal calcium phosphate was higher in alpha s1-kappa-casein micelles than in beta-kappa-casein micelles. kappa- and gamma-caseins and dephosphorylated alpha s1-casein were not cross-linked by colloidal calcium phosphate. Although kappa-casein was not cross-linked, chemically phosphorylated kappa-casein, of which the average phosphate content was 8.5 per molecule, was cross-linked. It is concluded that caseins are cross-linked through their ester phosphate groups by colloidal calcium phosphate.

Animals↗
PubMed1987

Inactivation of Crithidia fasciculata carbamoyl phosphate synthetase II by the antitumor drug acivicin.

In Crithidia fasciculata, carbamoyl phosphate synthetase II, which catalyses the first step of de novo pyrimidine biosynthesis, was separated from aspartate carbamoyltransferase by ammonium sulfate fractionation. The antitumor drug acivicin competitively inhibited the synthetase II activity with respect to L-glutamine, yielding an apparent Ki of 2 microM. In the absence of L-glutamine, acivicin resulted in a selective, time-dependent inactivation of L-glutamine-dependent activity of the enzyme, with an inactivation constant (Kinact) of 100 microM and a minimum inactivation half-time (T) of 0.2 min. L-Glutamine protected the enzyme from inactivation. These results are consistent with a postulate that acivicin is an active site-directed affinity analogue of L-glutamine, achieving irreversible inactivation. The inactivated enzyme retained ammonia-dependent activity. Acivicin stimulated the ammonia-dependent activity by increasing the Vmax value of the enzyme; apparent Km values for ammonia and MgATP were not affected. Differential action of acivicin on the Crithidia and mammalian synthetase II is discussed.

Ammonia↗
PubMed1987

Regulatory properties of carbamoyl-phosphate synthetase II from the parasitic protozoan Crithidia fasciculata.

1. At the lowered concentrations of 0.5 mM ATP and 1.5 mM MgCl2, 2.0 mM UTP, UDP and UMP inhibited the activity of Crithidia fasciculata carbamoyl-phosphate synthetase II by about 65, 80 and 40% respectively. 2. The result suggests that feedback inhibition of the activity by uridine nucleotides is a mechanism of regulation of the de novo pyrimidine biosynthetic pathway in C. fasciculata. 3. ADP, AMP and CDP inhibited the activity (about 70, 40 and 40%). 4. Excess Mg2+ at around 1 mM, relative to the ATP concentration, was required for the maximum activity. 5. 5-Phosphoribosyl 1-pyrophosphate had no significant effect on the activity under various conditions examined.

Animals↗
PubMed1987

Kinetic properties of carbamoyl-phosphate synthetase II (glutamine-hydrolyzing) in the parasitic protozoan Crithidia fasciculata and separation of the enzyme from aspartate carbamoyltransferase.

A high specific activity of carbamoyl-phosphate synthetase II (glutamine-hydrolyzing; EC 6.3.5.5) was demonstrated in extract of the cultured Crithidia fasciculata. The enzyme was separated from aspartate carbamoyltransferase by ammonium sulfate fractionation. Apparent Km for the synthetase for L-glutamine, NH4+, MgATP or bicarbonate was 0.27, 26, 1.7 or 1.7 mM at 2.0% dimethyl sulfoxide plus 0.3% glycerol. 8.6% dimethyl sulfoxide plus 1.4% glycerol decreased Km for L-glutamine to 0.10 mM, while Km for MgATP was unaffected. The higher solvent concentrations made Vmax markedly reduced, yielding the inhibition of the activity. These properties are unique to the Crithidia synthetase, compared with the mammalian enzyme.

Ammonium Sulfate↗