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Biomedical subjects

Y Aoki

Publications and source records attributed to Y Aoki.

At least 829 records · Page 46Linked to original sources
PubMed1979

Ductal carcinoma of the pancreas. Rationales for total pancreatectomy.

In order to evaluate total pancreatectomy as a surgical procedure for ductal carcinoma of the pancreas, a histopathological analysis was made on 18 resected specimens with special regard to the pattern of cancer growth in the pancreatic tissue. In five of them there was no lymphatic involvement or extrapancreatic invasion, but cancer extended continuously to the tail along with the pancreatic ducts and reached the end of the ducts in three cases. All 11 patients treated with Whipple's procedure died of recurrence, while of four total pancreatectomized patients, one with continuously invasive cancer to the end of the pancreatic duct has been living more than eight years postoperatively. We believe that total pancreatectomy for this type of "intraductal spreading cancer" without invasion beyond the pancreas is indicated as a radical procedure.

Aged↗
PubMed1979

[Carcinogenic effect of the 3-di-(hydroxymethyl-)amino-6-(5-nitro-2-furylethenyl-)1,2,4-triazines in Panfuran-S on mice].

The carcinogenic activity of Panfuran-S containing 3-di-(hydroxymethyl-)amino-6-(5-nitro-2-furylethenyl-)1,2,4-triazine (DHNT) orally administered to mice for 35 weeks was studied. DHNT produced malignant tumors of the forestomach in the highest incidence and also, in decreasing order of frequency, of the duodenum and/or jejunum, esophagus and urinary bladder. Forestomach squamous cell carcinomas were produced dose-dependently in mice receiving more than 350 ppm DHNT and rose to 100% in mice receiving 3,500 ppm. The incidence of duodenal and/or jejunal adenocarcinomas were 8 of 28 mice (29%) receiving 1,750 ppm and 10 of 17 mice (59%) receiving 3,500 ppm. The incidence of esophageal squamous cell carcinoma was 3 of 11 mice (11%) receiving 1,750 ppm and that of urinary bladder transitional cell carcinoma was 2 of 28 mice (7%) receiving 1,750 ppm and 1 of 17 mice (6%) receiving 3,500 ppm DHNT.

Animals↗
PubMed1979

delta-Aminolevulinic acid synthetase in erythroblasts of patients with pyridoxine-responsive anemia. Hypercatabolism caused by the increased susceptibility to the controlling protease.

Properties of delta-aminolevulinic acid synthetase in erythroblasts of patients with pyridoxine-responsive anemia were investigated with special reference to the protease in mitochondria of erythroblasts. delta-Aminolevulinic acid synthetase activity in erythroblasts of patients with this disease before treatment was extremely decreased, whereas it gradually increased in parallel with the improvement of anemia by the therapy with pyridoxal phosphate. The amount of apo-delta-aminolevulinic acid synthetase in erythroblasts before treatment was also extremely diminished. Apparent affinity to pyridoxal phosphate of the apo-delta-aminolevulinic acid synthetase obtained from erythroblasts of the patients was almost the same as that of normal controls. The activity of a new protease which is considered to be engaged in the regulation of delta-aminolevulinic acid synthetase levels in mitochondria of erythroblasts was shown to be in normal range in erythroblasts of the patients. On the other hand, apo-delta-aminolevulinic acid synthetase obtained from the patients was extremely sensitive to the protease. These results indicate that disturbance of heme synthesis characteristic to pyridoxine-responsive anemia could be ascribed to the hypercatabolism of delta-aminolevulinic acid synthetase caused by the increased susceptibility to the controlling protease in erythroblasts.

5-Aminolevulinate Synthetase↗
PubMed1979

Onchocerciasis in San Vicente Pacaya, Guatemala.

An epidemiological survey for onchocerciasis was carried out in the San Vicente Pacaya area of Guatemala. A total of 2,153 inhabitants were examined by a single skin snip, and 664 (30.8%) were positive for microfilariae. Slit lamp examination of the anterior chamber of the eye revealed microfilariae in 6.2%; the positive rate for microfilariae in the anterior chamber was proportional to the microfilarial density in the skin. The altitude-dependent character of onchocercal infection was shown in this mountainous area, suggesting that transmission occurs principally between 600 and 1,300 m. Of, 1,217 persons examined simultaneously by skin snip and by palpation for nodules, 587 were positive by one or both methods; 101 infections were detected by onchocercal nodules only and these were usually in children or persons living in areas of low endemicity. It was concluded that both the skin snip and a search for nodules are required for accurately determining the prevalence of onchocerciasis in Guatemala.

Adolescent↗
PubMed1979

Chronic toxicity of sodium nitrite in mice, with reference to its tumorigenicity.

Sodium nitrite has been widely used as one of the most effective food additives to tinge color on cured meat. However, it has been elucidated that this chemical is not merely a precursor of N-nitroso compounds, many of which are strongly carcinogenic, but also a mutagenic substance in biological tests. In order to ascertain the possible tumorigenicity of sodium nitrite itself, chronic toxicity of the agent in mice, by means of daily oral administration as drinking water for more than 18 months, in the concentration of 0.5 (maximum tolerated dose), 0.25, and 0.125%, was tested. As a result, development of various tumors, including thymic lymphoma, nonthymic lymphoid leukemia, pulmonary adenoma and carcinoma, and benign and malignant tumors in soft tissue, was seen in these mice. However, as to the incidence of tumors as well as the developmental time of each histologically classified tumor, no apparent difference was detected between those in the experimental groups and the control group.

Animals↗
PubMed1979

Long-term experiment of maximal non-carcinogenic dose of dimethylnitrosamine for carcinogenesis in rats.

Studies were made on the maximal non-carcinogenic dose of dimethylnitrosamine (DMN) in rats. Groups of Wistar strain rats of both sexes, 6 weeks old, were given standard diet without DMN (group 1), or containing 0.1 ppm DMN (group 2), 1.0 ppm DMN (group 3), or 10 ppm DMN (group 4) for 96 weeks and then sacrificed for hematological, serum-biochemical, and histopathological examinations. After 96 weeks, the weights of the body and main organs in the different groups were not significantly different. The leucocyte count and blood urea-nitrogen (BUN) in group 4 were slightly increased, but other serum findings were not significantly different in different groups. Hepatocellular carcinomas were found in group 3 (1 male and 3 females), but not in group 2. Hemangioendotheliomas of the liver, adrenal adenomas, pituitary adenomas, interstitial cell tumors of the testis, ovarian tumors, and leukemia were also found. Pyelonephritis was found in both experimental and control animals, but no kidney tumors developed with these dose levels of DMN. These results show that on long-term oral administration to rats, 1.0 ppm DMN is the minimum carcinogenic dose, while a level of about 0.1 ppm DMN is non-carcinogenic.

Animals↗
PubMed1979

Biliary scintigraphy with a new scanning agent, 99mTc-(SN)-pyridoxylidene-isoleucine.

99mTechnetium-pyridoxylidene-isoleucine (hereinafter referred to as 99mTc-PI) is a new biliary scintiscanning agent. It has been evaluated in both health volunteers and patients with known surgical biliary tract diseases. It results in imaging of the liver in three minutes and the common bile duct and duodenum in 10-20 minutes. Its advantages as a diagnostic tool in disease of the hepatobiliary systems are in reducing the amount of radiotracer required, in shortening examination time and in producing scintigrams of higher resolution.

Adolescent↗
PubMed1979

A sero-epidemiological study of onchocerciasis with the indirect hemagglutination test.

A sero-epidemiological study of onchocerciasis was carried out with the IHA test in Guatemala. In the endemic area, 94.8% of 191 subjects with microfilariae, 82.1% of 172 cases with onchocercal nodules, and 22.5% of 236 cases without either microfilariae or nodules gave positive reactions in the IHA test. On the other hand, the positive rate was 3.4% and 2.0% in each of 2 nonendemic populations. A follow-up study of reactors in the IHA with neither microfilariae nor nodules showed that 11 (42%) of 26 cases were microfilaria positive 6--7 mo after the first examination. A clear correlation was found between the results of the IHA test and skin biopsy in surveyed communities. The age distribution curve of the IHA test was closely associated with skin biopsy although the former was higher. IHA titers rose in proportion to microfilarial density. A sex-related difference was evident in the IHA positive rate in the subjects from medium and low endemic areas, but little difference was shown in individuals from a higher endemic area.

Adolescent↗
PubMed1978

Primary adenosquamous carcinoma of the stomach: experience of 11 cases and its clinical analysis.

1) During the last 10 years, 11 cases of primary adenosquamous carcinoma of the stomach were operated on. 2) Histologically, the specimens from the stomach showed adenocarcinoma with squamous differentiation in all the cases. 3) All the patients but 1 were males and their average age was 61.2 years. 4) The duration of illness prior to treatment was relatively long period of time and the chief complaints in over half of the patients were abdominal pain. 5) Eight cases showed metastases at the time of operation. Metastasis to the regional lymph nodes was observed in 8 cases and the squamous element was present in 5 of these cases. 6) There was no operative death. Followup study was made in 9 cases. Only 2 are still alive and the remaining 7 died of recurrence. The length of survival averaged 10.7 months.

Adenocarcinoma↗
PubMed1978

Production of adenocarcinomas of the small intestines of Wistar rats fed panfuran-S containing 3-di(hydroxymethyl)amino-6-(5-nitro-2-furylethenyl)-1,2,4-triazine.

Panfuran-S in the diet produced a high incidence of invasive and metastatic adenocarcinomas of the duodenum and the jejunum in outbred Wistar rats. Depressed growth and incidence of cancer production were dose-dependent. Adenocarcinomas of the duodenum were present in 2 of 18 (11%) rats that received 1,750 ppm 3-di(hydroxymethyl)amino-6-(5-nitro-2-furylethenyl)-1,2,4-triazine (DHNT) in the diet and in 11 of 19 (58%) rats that received 3,500 ppm DHNT. Adenocarcinomas of the jejunum were present in 10 of 18 (56%) and 16 of 19 (84%) rats that received 1,750 and 3,500 ppm DHNT, respectively, for 35-37 weeks. The only other tumors observed were squamous cell papillomas of the forestomach. Histologically, most of the adenocarcinomas appeared tubular or papillary and were similar to adenocarcinomas in the small intestine of man and also to human intestinal-type adenocarcinoma of the stomach. This system provided a useful experimental model for the study of the pathogenesis of carcinoma of the small intestine.

Adenocarcinoma↗