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Biomedical subjects

Y Hata

Publications and source records attributed to Y Hata.

At least 451 records · Page 25Linked to original sources
PubMed1984

Effect of anti-alpha-fetoprotein serum on human hepatoblastoma.

There is no definitive treatment of hepatoblastoma. Except for radical resection, the prognosis of unresectable cases remains pessimistic. Therefore, the development of new anticancer drugs for this tumor is urgently needed. Using the human hepatoblastoma cell line (c-HB-3) we demonstrated that horse anti-alpha-fetoprotein containing serum suppressed proliferation of the hepatoblastoma cells. This effect was dependent on the duration of exposure and the concentration of anti-alpha-fetoprotein serum.

Animals↗
PubMed1984

Well-controlled comparative study of the clinical effectiveness of intravenous mexiletine and procainamide on ventricular premature contraction.

In a well-controlled study the clinical efficacy of a single intravenous injection of mexiletine (3 mg/Kg) on ventricular premature contractions was compared with that of procainamide (10 mg/Kg) using continuous electrocardiographic recordings. Of the 56 subjects studied, 55 were analyzed. These consisted of 28 cases in the mexiletine group and 27 in the procainamide group. The backgrounds of both groups were considered to be equivalent. Effectiveness on VPC ("marked and moderate improvement", as judged by the subcommittee) was seen in 88% of the mexiletine group and 84.6% of the procainamide group. This difference was not significant. The duration of efficacy was almost the same in the 2 groups. Overall improvement was the same as improvement in VPC. No significant difference was observed in the incidence of side effects. Five patients in the mexiletine group and 3 in the procainamide group reported side effects. The main side effect was light-headedness in the mexiletine group and a decrease in blood pressure in the procainamide group. A decrease in blood pressure was observed in 1 case in the mexiletine group but this was restored by an intravenous infusion of noradrenaline. Mexiletine had little effect on blood pressure, while procainamide induced a drop in the systolic pressure. This difference was significant. Overall utility ("markedly and moderately useful", as judged by the subcommittee) was seen in 84.0% of the mexiletine group and 84.6% of the procainamide group. There was no significant difference between the 2 groups. From the above results, it is concluded that mexiletine (3 mg/Kg) is as efficacious as procainamide (10 mg/Kg) in the treatment of VPC but that, unlike procainamide, mexiletine has little effect on blood pressure.

Adolescent↗
PubMed1984

[Anticancer effect of peplomycin on advanced recurrent breast cancer].

The anticancer effect of peplomycin (PEP) on advanced or recurrent breast cancer was investigated clinically and histopathologically. Stage III (n = 12), Stage IV (n = 2) and recurrent (n = 6) breast cancer patients were treated with PEP of which 10 mg were administered 3 times a week for 3 weeks either intravenously (n = 13) or intra-arterially (n = 7, via a catheter inserted into the subclavian artery). A decrease in tumor volume of more than 50% was obtained in 38.5% of the intravenously treated cases and in 28.6% the intra-arterially treated cases. Histologically, grades II b and III were observed in 66% of patients according to Oboshi's classification. These investigations suggest the effectiveness of PEP on breast cancer.

Adult↗
PubMed1984

[Nuclear magnetic resonance computed tomography (NMR-CT) of malignancies].

The physical principles of nuclear magnetic resonance (NMR) imaging were initially outlined. In the present proton images, T1 and T2 relaxation times were more important than proton density in determining the varying intensity of the tissue. Early clinical experiences of NMR for malignancies of the head and neck region, chest, abdomen, pelvis and extremities were also presented. There was superb ability for soft tissue characterizations, accentuating intensity difference between tissues with different T1 and T2 relaxation time. Although the spatial resolution of NMR-CT appeared to be inferior to X-CT, the absence of streak artifacts or X-ray beam hardening were advantageous. Because of the absence of significant NMR signal from rapidly flowing blood, the differentiation of vessels and soft tissue masses was easily accomplished by NMR-CT without employing contrast material. Multisection scans were performed in most cases with not only transverse but sagittal or coronal imaging by simply varying the sequence of pulse gradient magnetic field. While more experience is required, NMR-CT has a promising future in the imaging modality for malignancies.

Abdominal Neoplasms↗
PubMed1983

Structure of rice ferricytochrome c at 2.0 A resolution.

The crystal structure of ferricytochrome c from rice embryos has been solved by X-ray diffraction to a resolution of 2.0 A, applying a single isomorphous replacement method with anomalous scattering effects. The initial molecular model was built on a graphics display system and was refined by the Hendrickson and Konnert method. The R factor was reduced to 0.25. Rice cytochrome c consists of III amino acid residues. In comparison with animal cytochromes c, the peptide chain extends for eight residues at the N-terminal end, which is characteristic for plant cytochromes c. These additional residues display a collagen-like conformation and an irregular reverse turn, and are located around the C-terminal alpha-helix on the surface or the rear side of the molecule. Two hydrogen bonds between the carbonyl oxygen of the N-terminal acetyl group and O eta of Tyr65, and between the peptide carbonyl oxygen of Pro-1 and O epsilon 1 of Gln89, are involved in holding these eight residues on the molecular surface, where Tyr65 and Gln89 are invariant in plant cytochromes c. Except for the extra eight residues, the main-chain conformations of both rice and tuna cytochromes c are essentially identical, though small local conformational differences are found at residues 24, 25, 56 and 57.

Cytochrome c Group↗
PubMed1983

Enzyme-induced aziridine formation by isolated hepatocytes.

The metabolism of 2-bromoethylaminonaphthoquinone in hepatocytes isolated from rats was studied. This compound was chemically inert in the reaction system used. However, in buffer solution containing isolated hepatocytes, it was gradually converted into aziridinylnaphthoquinone. Under the same reaction conditions, 4-chlorobutylaminonaphthoquinone also gave the cyclization products, pyrrolidinylnaphthoquinone. Cellular GSH decreased in both reactions.

Animals↗
PubMed1983

Enzyme-induced aziridine formation by rat liver microsomes.

The metabolic reaction of 2-chloroethylaminobenzoquinone derivatives with rat liver microsomes was studied. In buffer solution containing cellular macromolecules such as DNA or protein, 2-chloroethylaminobenzoquinones were usually stable and could be recovered quantitatively after an appropriate period of incubation. However, in microsomal solution, they were gradually converted into aziridinobenzoquinones via elimination of hydrogen chloride by NADPH-dependent enzyme action. Based on the study of the enzymatic cyclization reaction of 4-chlorobutylaminonaphthoquinone, we concluded that the hydroquinone derivative is an important intermediate for aziridine formation.

Animals↗
PubMed1983

Species and strain differences in mepirizole-induced duodenal and gastric lesions.

Species and strain differences in mepirizole-induced duodenal and gastric lesions were studied. Mepirizole at 200 mg/kg given orally induced deep duodenal ulcers and gastric erosions in nonfasted Sprague-Dawley, Fisher, Wistar, and Donryu rats at an incidence of over 75%. Mepirizole at 300 mg/kg given orally also induced penetrating duodenal ulcers in nonfasted rabbits at an incidence of 50%. There was little or no damage to the duodenum and stomach in mice and dogs given 200-300 mg/kg of mepirizole orally or subcutaneously. The stomachs of fasted guinea pigs given 200 mg/kg of mepirizole had superficial erosions at a high incidence (93.3%). Mepirizole at 200 mg/kg given intraduodenally significantly reduced the volume of gastric juice but increased the acidity and pepsin activity in both pylorus-ligated and acute fistula rats. In chronic fistula rabbits, however, the agent at 200 mg/kg given orally reduced the volume and acidity, but increased the pepsin activity. The mechanism of duodenal ulceration by mepirizole differs slightly in rats and rabbits.

Animals↗
PubMed1983

The incidence of simple renal cyst by computed tomography.

Five hundred and forty-two abdominal computed tomography (CT) scans, including the kidneys, were reviewed to investigate the incidence of simple renal cysts. Increasing frequency with age was clearly demonstrated. The incidence in patients 50 years of age and over was at least 27%. Two thirds of simple renal cysts were 2 cm or less in diameter. Cysts were usually observed as exo-endoparenchymal or endoparenchymal lesions on CT.

Adolescent↗
PubMed1983

Staging of renal cell carcinoma by computed tomography.

To evaluate the efficacy of computed tomography (CT) in the diagnostic workup of renal cell carcinoma, CT findings were correlated with surgical and pathological findings in 40 cases. Fifteen cases without obliteration of perinephric fat or thickening of Gerota's fascia were confined within the renal capsule. Eighteen lesions showing anatomic contact with adjacent organs were either within the renal capsule or Gerota's fascia but never beyond Gerota's fascia. Two cases (Stage II) showed thickening of Gerota's fascia and two cases (Stage IV) showed tumor infiltration into the spleen. Computed tomography was found to be a useful method for the investigation of tumor thrombosis and lymph node metastasis.

Adenocarcinoma↗