Biomedical subjects

Y Hiasa

Publications and source records attributed to Y Hiasa.

At least 19 recordsLinked to original sources

PubMed1992

Carcinogenicity study in rats of phytic acid 'Daiichi', a natural food additive.

The carcinogenicity of phytic acid 'Daiichi' (PA), a natural food additive, was examined in Fischer 344 rats of both sexes. PA was added to the drinking-water of groups of 60 male and 60 female rats at levels of 1.25 or 2.5% for 100-108 wk. There was a dose-dependent reduction in the mean final body weights of rats treated with PA. Necrosis and calcification of the renal papillae were observed in PA-treated rats, but not in the controls. The incidences of necrosis (calcification) were as follows: one (three) out of 57 males given 2.5% PA; one (none) out of 59 males given 1.25% PA; 10 (17) out of 55 females given 2.5% PA; six (six) out of 58 females given 1.25% PA. Renal papillomas occurred in three of the high-dose male rats, four of the high-dose female rats, and three of the low-dose female rats. The development of papillomas seemed to be related to calcification and necrosis of the renal papillae induced by PA. While many other tumours developed in all groups, including the controls, the organ distribution of these neoplasms and their histological characteristics did not differ significantly from those known to occur spontaneously in this strain of rats.

Animals↗

PubMed1992

Promoting effects of potassium dibasic phosphate on early-stage renal carcinogenesis in unilaterally nephrectomized rats treated with N-ethyl-N-hydroxyethylnitrosamine.

The effects of potassium dibasic phosphate (PDP), potassium aluminum sulfate (PAS) and copper sulfate (CS) on early-stage renal carcinogenesis were investigated in unilaterally nephrectomized male Wistar rats after N-ethyl-N-hydroxyethylnitrosamine (EHEN) administration. After feeding 1,000 ppm EHEN, or basal diet for 2 weeks and removal of the left kidney at week 3, male Wistar rats were divided into 8 groups of 20 rats each. These groups received the following dietary treatments: 50,000 ppm PDP, 50,000 ppm PAS, 5,000 ppm CS or basal diet, respectively, for 18 weeks from weeks 3 to 20. The average numbers of adenomatous hyperplasias counted as preneoplastic lesions in the EHEN with 50,000 ppm PDP group were significantly higher than in the EHEN alone group or the EHEN followed by 50,000 ppm PAS or 5,000 ppm CS group. The treatment with 50,000 ppm PDP induced renal calcification and promoted the development of preneoplastic lesions in unilaterally nephrectomized rats treated with EHEN, but that with 50,000 ppm PAS or 5,000 ppm CS did not.

Animals↗

PubMed1992

Immunohistochemical study of a newly defined oncofetal antigen (HGR-Ag) in tumors of the central nervous system.

The oncofetal antigen (HGR-Ag) in brain tumors was newly defined using the monoclonal antibody derived from tissue extracts of an anaplastic astrocytoma. The HGR-Ag was purified through sequential chromatography using diethylaminoethyl-Sephadex A-50 and Con-A Sepharose affinity columns. The latter method indicated that HGR-Ag is not a glycoprotein, and Western blot analysis indicated a molecular weight of 80-90 kd. Purified antigen was used to produce antibody. This new antibody, designated H1H2, was shown to be an immunoglobulin G1 by immunodiffusion assay. Histological/immunohistochemical studies using the H1H2 antibody on paraffin and frozen tissue sections showed HGR-Ag to be intracellular rather than membrane-associated. The immunoreactivity of H1H2 was highest in malignant astrocytomas, glioblastomas, and normal fetal brain tissue. Neurinomas and certain carcinomas of other organs showed lesser, variable reactivity to H1H2. The strength of the antigen-antibody binding was correlated with the degree of malignancy in human gliomas. H1H2 bound to fetal brain tissue and undifferentiated neural tumors, but not to normal adult brain tissue, so HGR-Ag is probably a fetal oncoantigen.

Animals↗

PubMed1992

[Effects of sex hormones and propylthioracil on growth of transplantable rat thyroid tumor with estrogen receptor (ER)].

UNLABELLED: Effects of hormones (E2: estradiol, TP: testosterone) and propylthiouracil (PTU) on the growth of transplantable rat thyroid tumor (F2D1) having estrogen receptors were studied. Rat thyroid neoplasms, induced by N-bis (2-hydroxypropyl) nitrosamine, were inoculated subcutaneously from donor to recipient rats, in order to establish 16 transplantable rat thyroid tumor lines. The grafts were used for histological studies and for the assay of estrogen receptor (ER) and androgen receptor (AR). Of these lines, we designated papillary carcinoma, which was positive for ER (N: 12.5fmol/mg protein, Kd: 0.4nM) but negative for AR, as F2D1. For studies on the effects of sex hormones and PTU on the growth of transplantable tumors, the rats which had been inoculated with tumors were divided into the following 8 groups; (1) Intact, (2) PTU, (3) ovariectomy (OV), and (4) OV + E2 for female, and (5) Intact, (6) PTU, (7) castration (CA), and (8) CA + TP for male. RESULTS: The growth rate of F2D1 in female rats was decreased by OV, but no change was observed in OV + E2 as compared with Intact. CA and CA + TP in male rats did not influence the growth rate. PTU produced a significant increase in the growth rate in both sexes. These results demonstrate that estrogen and PTU act on the growth of ER-positive rat thyroid tumors.

Animals↗

PubMed1992

Chemical carcinogenesis in the thyroid gland.

Chemical carcinogens and promoters in thyroid carcinogenesis may be divided into two types, one having goitrogenic effects, the other not having these effects e.g. phenobarbital, 4,4'-diaminodiphenylmethane. The influence of sex hormones like estrogen and testosterone remains unclear, although some thyroid tumors have estrogen receptors. Further studies in this area are necessary.

Animals↗

PubMed1991

Apolipoprotein A-I deficiency due to a codon 84 nonsense mutation of the apolipoprotein A-I gene.

The molecular genetic defect of a female patient with apolipoprotein A-I (apoA-I) deficiency and premature atherosclerosis was examined. Her parents were first cousins. Her plasma density fraction from 1.063 to 1.21 g/ml contained no apoA-I on SDS/PAGE and no measurable high density lipoprotein cholesterol. Southern blot hybridization showed no gross abnormality to be present in the patient's apoA-I gene and homozygosity for a haplotype of restriction fragment length polymorphisms in the apoA-I gene region. Sequencing after amplification by PCR revealed a codon 84 nonsense mutation (CAG----TAG, Gln----stop) of exon 4 and a codon 67 missense mutation (GCC----ACC, Ala----Thr) of exon 3 in the patient's apoA-I gene. The data from dot-blot hybridization with allele-specific oligonucleotide probes indicated that she was homozygous for the apoA-I gene with regard to the two mutations. The codon 37 missense mutation was also detected in the apoA-I gene of 6 out of 60 controls, who all had normal levels of apoA-I and high density lipoprotein cholesterol, suggesting that the missense mutation is polymorphic and not associated with apoA-I deficiency. These findings indicate that homozygosity for the apoA-I gene with codon 84 nonsense mutation causes the deficiency of apoA-I and of high density lipoprotein cholesterol in the patient.

Adult↗

PubMed1991

Negative U wave during percutaneous transluminal coronary angioplasty.

To clarify the clinical significance of the negative U wave during acute myocardial ischemia, the appearance of the U wave and ST-segment elevation on electrocardiography during percutaneous transluminal coronary angioplasty (PTCA) of the left anterior descending artery (LAD group: 11 patients) or right coronary artery (RCA group: 18 patients) was studied. During PTCA, U-wave inversion (newly developed negative U wave, and increased negativity of the pre-existing negative U wave) was observed in 37 (90%) of 41 patients in the LAD group and in 16 (89%) of 18 patients in the RCA group. The incidence of ST-segment elevation was similar to that of U-wave inversion; however, U-wave inversion appeared before detectable ST-segment elevation in 20 patients (49%) in the LAD group and in 4 patients (22%) in the RCA group. Moreover, U-wave inversion was observed frequently in a wider range of leads than ST-segment elevation. These results suggest that the U wave is a more sensitive indicator of myocardial ischemia than ST-segment elevation in some patients, and that a negative U wave may be produced by a different mechanism than that which produces ST-segment deviation, although both are related to myocardial ischemia.

Angioplasty, Balloon, Coronary↗

PubMed1991

Relationships between serum thyroid stimulating hormone levels and development of thyroid tumors in rats treated with N-bis-(2-hydroxypropyl)nitrosamine.

Relationships between serum thyroid stimulating hormone (TSH) levels, carcinogen dose and development of thyroid tumors were studied in Wistar rats of both sexes treated with N-bis-(2-hydroxypropyl)nitrosamine (DHPN). DHPN (210 mg/100 g body wt) was injected i.p. weekly. Wistar rats were used, divided into five groups of males (M1-M5) and five groups of females (F1-F5). M1 and F1 received one injection of DHPN, M2 and F2 two injections of DHPN, M3 and F3 three injections of DHPN, M4 and F4 four injections, and M5 and F5 as control rats received saline vehicle. The resultant incidences of total thyroid tumors were 4% in group M1, 24% in M2, 80% in M3, 76% in M4, 0% in F1, 4% in F2, 20% in F3, 17% in F4 and 0% in M5 and F5. Thus dose dependence for DHPN carcinogenesis was found in both sexes for up to at least three injections of DHPN and in all cases males proved more susceptible than females. Similar results were gained for carcinomas treated separately. A sex difference in DHPN induction of thyroid tumor was thus shown for Wistar rats opposite to that reported to exist in humans. However, no clear relationship between dose of DHPN or incidence of thyroid tumors and serum TSH concentration was evident at the end of the experiment (week 30).

Adenoma↗

PubMed1991

Possible application to medium-term organ bioassays for renal carcinogenesis modifiers in rats treated with N-ethyl-N-hydroxyethylnitrosamine and unilateral nephrectomy.

The effects of the renal tumor promoters; beta-cyclodextrin (beta-C), DL-serine (DL-S), basic lead acetate (LA), trisodium nitrilotriacetate monohydrate (NTA) and potassium bromate (KB), and diethylene glycol (DEG) as a negative control, on early stage of renal carcinogenesis were investigated in unilaterally nephrectomized male Wistar rats after N-ethyl-N-hydroxyethylnitrosamine (EHEN) administration. Wistar male rats were fed 1000 ppm EHEN diet for 2 weeks and the left kidney was removed at week 3, then the animals were divided into 7 groups of 15 rats each. These groups received the following treatments: 1000 ppm LA, 10000 ppm NTA or 500 ppm KB diet for 18 weeks from week 3; 45 mg/100 g body wt./day of beta-C injected sc for 7 days; 100 mg/100 g body wt. of DL-S injected sc biweekly for 6 weeks; 5% DEG in drinking water as a negative control for two days. Five rats in each group were killed at weeks 8, 12 and 20 and their kidneys were examined histologically. At week 20, the average numbers of adenomatous hyperplasias seen as preneoplastic lesions in the beta-C, DL-S, LA, NTA or KB groups were significantly higher than those in the DEG or control groups. Thus within a relatively short period of 20 weeks, promoting effects of chemicals can be detected as a significant increase of adenomatous hyperplasias in this model.

Animals↗

PubMed1991

Immunohistochemical detection of estrogen receptors in paraffin sections of human thyroid tissues.

The optimal demonstration of estrogen receptor binding in thyroid tissues was made under conditions of 10% protease in 50 mM Tris-HCl buffer (pH 7.6) for 10 min as the pretreatment digestion step, incubation of primary antibody (ER-ICA monoclonal kit; Abbott Laboratories) at 37 degrees C for 2 h and incubation of secondary antibody (ABC kit; Vector) at 37 degrees C for 40 min. Thyroid tissues used for assessing the reaction were 17 cases of goiter, 25 adenoma cases, 27 cases of papillary carcinoma, 14 cases of follicular carcinoma and 10 latent cancer cases. Incidences of positive estrogen receptor reaction were 22% (11/51) for all thyroid cancers, 20% (5/25) for the thyroid adenomas and 59% (10/17) for goiters. 15% (4/27) of papillary carcinomas, 21% (3/14) of follicular carcinomas and 40% (4/10) of latent cancers proved positive, the estrogen receptor reaction being limited to the nuclei of thyroid follicular/papillary type cells.

Deoxyribonucleases↗

PubMed1991

[Highly metastatic mammary tumors in M. m. musculus Sub-Jyg (JYG mouse)].

The present paper reports the highly metastasis of mammary tumors in Chinese wild mouse M. m. musculus Sub-Jyg (JYG mouse), which was recently inbred at the National Institute of Genetics, Mishima, Japan. The incidence of mammary tumors at 18th generation was 89% at about 9 months of age. Histology of mammary tumors in 19 cases examined were medullary or papillary adenocarcinoma (Comedo type) with highly anaplastic features. Metastasis was found not only in the lungs (53%), but also in the liver (21%) and spleen (16%), respectively. MMTV antigen and particle were also found in various organs by immunoperoxidase method and electronmicroscopy. As a result of present observation, JYG mouse was considered to be a unique model in the study of the metastasis of mammary tumors to the liver and spleen.

Adenocarcinoma, Papillary↗

PubMed1991

Spontaneous intracerebral hemorrhage in cases of severe angiospasm following ruptured aneurysm--a pathological study.

Eleven patients with a history of moderate or severe angiospasm following ruptured cerebral aneurysm developed spontaneous intracerebral hemorrhage between 31 and 111 months after aneurysm surgery. In all cases, hemorrhage occurred in the ipsilateral hemisphere to the original aneurysm. In nine patients, the hematoma was surgically evacuated and bleeding perforating arteries were resected for histological examination. Computed tomographic scans showed the hematomas to be unusually extended compared to those after hypertensive intracerebral hemorrhage. The histological examination showed various degenerative changes in the elastic lamina and media of the perforating arteries, even though most patients were young and normotensive. These findings suggest that patients who have suffered severe cerebral angiospasm may have a higher risk for subsequent development of intracerebral hemorrhage than those without prior angiospasm.

Aged↗

PubMed1991

Multiple calcified metastatic brain tumor--case report.

The authors describe an unusual case of pulmonary small cell carcinoma with numerous calcified metastatic nodules of the brain in a 62-year-old female. Computed tomographic scanning and magnetic resonance imaging demonstrated these lesions with ring enhancement. Autopsy revealed about 30 calcified metastatic nodules in the brain, but no calcification in the pulmonary lesion. Histological examination of the brain lesions disclosed necrosis and calcification in the center and small cell carcinoma cells in the periphery.

Brain Diseases↗

PubMed1991

[Tolerance to a sustained release form of isosorbide dinitrate: comparison between 20 mg four times and 40 mg twice-daily administrations].

Attenuation of antianginal effects of oral isosorbide dinitrate in a sustained release from (ISDN-SR) were studied using the treadmill exercise test in eleven patients with stable exertional angina and a positive exercise test. We compared the four-time-daily administration of 20 mg with a twice-daily regimen of 40 mg for 10 days using the double-blind, crossover method. On the 1st day of the administration, with both regimens, the treadmill walking time, the time to 1mm and 2mm ST depression, and several hemodynamic parameters increased significantly. These improvements were reduced gradually on day 5 and day 10 after the administration. In the comparison between the four-time-daily and two-time-daily regimens, the former application showed clearer antianginal and hemodynamic effects than the latter regimen, but these effects were attenuated more markedly in the four-time daily administration. With both dosage regimens, the plasma ISDN concentrations increased gradually. With the long-term four-time-daily regimen, the time-to-time changes of the ISDN concentration were smaller each day. These data suggest that tolerance to oral ISDN-SR exists even if it is applied only two time daily, but its degree is less than when a four-time-daily dose in administered.

Administration, Oral↗

PubMed1991

[Wrapping operation for Stanford type A acute dissecting aneurysms].

Four cases of Stanford type A acute aortic dissection were treated by wrapping operation. After careful dissection between the dilated ascending aorta and right pulmonary artery, 8 mm woven Dacron vascular prosthesis was passed around the aorta and tightened. Further enforcement wrapping was carried out using several prostheses from aortic root to the innominate artery. We call this technique "wrapping operation". Emergent operations were performed on all patients because of cardiac tamponade, 6.8-33 hours after the onset of dissection. Three patients are doing well 17-39 months after the operation, but only 1 patient died early postoperative period because of DIC and multiple organ failure. And 2 patients was showed closure of entry of the ascending aorta by the postoperative aortography. We think that the wrapping operation is a useful technique for the patients of ruptured Stanford type A acute dissecting aneurysms.

Aortic Dissection↗

PubMed1991

[A case of left atrial giant thrombus which appeared in a short period].

We reported a case with left atrial giant thrombus (LAGT) which appeared over a period of six months. The patient was a 65-year-old woman who came to our hospital complaining of syncopal attack. Her electrocardiogram showed atrial fibrillation with very slow ventricular response, and there was cardiac arrest for 1500 ms, mitral stenosis and regurgitation, aortic and tricuspid regurgitations were recognized in the echocardiogram. By coronary angiography, 90% stenosis in the left circumflex artery (LCX) was found, and using transseptal left atrium heart catheterization, pressure gradient from the left atrium to the left ventricle was also measured. We diagnosed that her valvular diseases were mild. To protect her from unconsciousness and heart failure, a permanent pacemaker was implanted and PTCA for LCX lesion was performed. After six months, we found LAGT by echocardiography. It is very rare that LAGT is formed in a short period. We suggested that the changes of hemodynamics caused by transseptal left atrial catheterization or the permanent pacemaker implantation effected the formation of the LAGT.

Aged↗

PubMed1991

[The step to improve the operative outcome in patients with severe valvular heart disease].

In an effort to improve the operative outcome in severe valvular heart disease, we investigated the effects of low-dose infusion of dopamine and dobutamine up to the day of operation. New York Heart Association Functional Class was improved significantly before operation, as compared with at the time of admission. It was possible to perform operation on individual patients when their physical condition seemed to be at their best. In patients with fear of postoperative renal failure, hemodialysis was combined during cardiac surgery to prevent failing to renal dysfunction after operation. As the result of these procedures, we were able to obtain satisfactory result. In patients with severe valvular heart disease, the preoperative combined infusion of dopamine and dobutamine, and hemodialysis during cardiac surgery to prevent postoperative renal dysfunction seemed to improve the operative outcome.

Adult↗

PubMed1990

Differentiation between left circumflex and right coronary artery occlusions: studies on ST-segment deviation during percutaneous transluminal coronary angioplasty.

To distinguish between acute occlusion of the right coronary artery (RCA) and the left circumflex artery (LCx) by electrocardiography, we studied ST-segment deviation during balloon inflation in percutaneous transluminal angioplasty. The composite electrocardiographic criteria based on ST-segment deviations increased the diagnostic specificity: that is, the finding of inferior infarction (ST-segment elevation in leads II, III, aVF) without lateral infarction (ST-segment elevation in leads V5,6) was highly suggestive of RCA occlusion (sensitivity and specificity: 35 of 43 cases, 81.4%; and 33 of 36 cases, 91.7%), whereas ST-segment elevation in leads V5,6 (LCx: 23 of 36 cases; 63.9%, RCA: 5 of 43 cases; 11.6%) or isolated ST-segment depression in leads V2-4 (LCx: 9 of 36 cases; 25.0%, RCA: none of 43 cases) was highly suggestive of LCx occlusion. These results indicate that the composite electrocardiographic criteria were useful in predicting the artery involved in acute myocardial infarction, although any single criterion was not sensitive or specific enough to differentiate right from left circumflex coronary artery occlusion.

Angioplasty, Balloon, Coronary↗