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Biomedical subjects

A Yoshida

Publications and source records attributed to A Yoshida.

At least 1,009 records · Page 56Linked to original sources
PubMed1985

Induction of tumors with cycasin in newborn and preweanling rats.

Comprehensive studies of carcinogenesis in newborn or preweanling SD rats were conducted under various dose schedules of cycasin (CAS: 14901-08-7) administration. When cycasin was given sc to newborn rats at day 0, tumors were detected in more than 80% of rats of both sexes; kidney tumors were by far the most common. The incidences of tumors declined in the older groups, namely, over 60% in both sexes in the 7-day group, 55% in males and 8.3% in females in 14-day rats, and 0% in 21-day groups. By multiple administration, tumor incidences elevated considerably. Administration ip of cycasin also gave rise to tumor induction in newborn rats. A total of 435 kidney tumors found in the experiments were studied pathologically. Most of them were classified as mesenchymal tumor; some of them metastasized. A few other tumors were found in the liver and colon.

Adenocarcinoma↗
PubMed1985

Normal mRNA content in a phosphoglycerate kinase variant with severe enzyme deficiency.

A phosphoglycerate kinase variant, PGK-Matsue, was associated with a severe enzyme deficiency, congenital nonspherocytic hemolytic anemia, and mental disorders. The variant enzyme exhibited a slower cathodal electrophoretic mobility and lower affinity toward the substrates. The enzyme activity in the variant's red cells, muscles, and fibroblasts was about 5% of that of normal cells. The content of mRNA in the variant fibroblasts was compared to that of normal cells by the semiquantitative dot hybridization method, and, more accurately, by the liquid hybridization method, using a human PGK cDNA as a probe. It was found that the mRNA level in the variant fibroblasts was comparable to that of normal fibroblasts. The results strongly suggest that the major cause of enzyme deficiency in PGK-Matsue is a seven- to 10-fold increase in the mutant enzyme degradation.

Cell Line↗
PubMed1985

[A case of advanced male breast cancer treated effectively with estrogen].

A 47-year-old man was admitted because of a left axillary tumor. A biopsy of the tumor disclosed adenocarcinoma. The bone survey showed multiple sclerotic metastases. Thirteen months after his first admission, a left breast tumor developed and a simple mastectomy revealed a papillotubular carcinoma. Skin metastases appeared postoperatively and were exacerbated with accumulation of pericardial effusion and a high CEA level (401.7 ng/ml) despite radiation and chemotherapy. Estrogen therapy with diethylstilbestrol sodium phosphate was started, resulting in the disappearance of pericardial effusion and skin metastases. The patient remains well 10 months after starting estrogen therapy with a normal CEA level.

Adenocarcinoma↗
PubMed1985

Suppressed expression of blood group B antigen and blood group galactosyltransferase in a preleukemic subject.

The B antigen activity was severely diminished in a patient's RBCs at the preleukemic stage prior to chemo- or radiotherapy. The amount of H sites of the patient's RBC membranes was found to be comparable to that of O RBC membranes. The activity of alpha (1----2) fucosyltransferase (H enzyme) was not severely decreased in the patient's plasma and bone marrow. However, the activity of alpha (1----3) galactosyltransferase (B enzyme), which converts H substance to B substance, was drastically reduced in the patient's bone marrow. Thus, the diminished B antigen in the patient's RBCs was caused mainly by the blockage of conversion of the H substance to B substance. It is suggested that the viral oncogene linked to the ABO locus at q34 of chromosome No. 9 would occasionally suppress the expression of blood group A and B enzymes and A and B antigens.

ABO Blood-Group System↗
PubMed1985

Regression with secretory changes of ovary-independent rat mammary carcinoma by pharmacological doses of estrogen.

MT6 tumor is a transplantable ovary- and prolactin-independent rat mammary carcinoma containing estrogen and progesterone receptors. The effects of daily injections of 1 mg or 10 micrograms of 17 beta-estradiol for 28 days on the morphological changes and the proliferation and death of MT6 cells grown in male inbred Sprague-Dawley rats were investigated. Uptake values of 5-[125I]iodo-2'-deoxyuridine per g of living tumor, used as an index of cell proliferation, were not significantly reduced by treatment with 1 mg of 17 beta-estradiol. When tumor cell proliferation was evaluated by labeling with 5-[125I]iodo-2'-deoxyuridine just before the treatment, the radioactivity incorporated by the whole tumor remained almost unchanged in intact rats but was decreased slightly on day 21 and significantly on day 28 of the treatment in the rats treated with 1 mg of 17 beta-estradiol. Secretory changes characterized by the appearance of secretion in the lumina, vacuolation in the cytoplasm, marked increase in vesicular endoplasmic reticulum, accumulation of mature protein secretory granules and abundance of lipid droplets were observed in MT6 cells in rats treated with 1 mg of 17 beta-estradiol from the 14th day of treatment. On the 28th day, necrosis of MT6 cells with secretory changes was found. These changes were not found in intact rats or rats treated daily with 10 micrograms of 17 beta-estradiol. These findings suggest that the inhibitory effect of daily injections of 1 mg of 17 beta-estradiol on the growth of ovary- and prolactin-independent MT6 tumor is mainly due to secretory changes followed by loss of tumor cells induced by pharmacological doses of estrogens.

Animals↗
PubMed1985

Enhancement of methyl mercury-induced lipid peroxidation by the addition of ascorbic acid.

Effects of mercuric chloride (HgCl2) and methylmercuric chloride (MMC) in the presence of ascorbic acid on lipid peroxidation in rabbit renal cortical mitochondria were studied. The addition of ascorbic acid showed no effect on HgCl2-induced lipid peroxidation, but ascorbic acid plus MMC were able to stimulate the lipid peroxidation markedly. This result suggests that in the presence of ascorbic acid MMC has a powerful stimulatory effect on the lipid peroxidation in mitochondria.

Animals↗
PubMed1985

Crystalline retinopathy: evaluation of blood-retinal barrier by vitreous fluorophotometry.

A 58-year-old man with typical crystalline retinopathy had started complaining of night blindness in both eyes at the age of 56 years. The visual acuity was 0.8 in the right eye and 0.7 in the left eye. Ophthalmoscopic examination showed crystal deposits scattered throughout the posterior pole of the fundus in both eyes. Electroretinogram showed subnormal amplitude and the light-peak/dark-trough ratio of the electrooculogram was reduced. Fluorescein angiography demonstrated atrophy of the pigment epithelium and partial loss of the choriocapillaris in the posterior pole. The crystal deposits were not stained with fluorescein. During the 3-year follow-up period, the crystal deposits coalesced, disappeared and reappeared at new places. Vitreous fluorophotometry was performed in both eyes of this patient. It was found that the rate of fluorescein penetration from the blood into the vitreous was markedly increased and the rate of the dye removal from the vitreous was greatly reduced, as compared to the results in normal subjects. Based on these clinical and fluorophotometric findings, it was concluded that the function of the blood-retinal barrier, particularly of the retinal pigment epithelium, was affected in this disease.

Capillary Permeability↗
PubMed1985

[Clinical evaluation of aztreonam in children].

Clinical usage of aztreonam (AZT), a newly synthesized antibiotic which belongs to monobactam, was evaluated for its efficacy and safety in 22 patients aged from 1 month-old to 13 year-5 month-old with bacterial infections and the following results were obtained. AZT was administered to 4 patients with pyelonephritis and 10 patients with tonsillitis at a daily dosage of 40.4-120.9 mg/kg and to 5 patients with clinical sepsis associated with agranulocytosis caused by intensive antileukemic therapy at a daily dosage of 142.4-171.4 mg/kg, divided into 3 or 4, by intravenous injection or by 30 minutes drip infusion. The clinical results of these 19 evaluable patients were as follows: excellent; 10 cases, good; 5 cases, fair; 2 cases, poor; 2 cases. The over all efficacy rate was 78.9% and that of pyelonephritis and tonsillitis was 100.0%. No clinical side effects were observed in any 23 patients, including a patient who proved to be suffering from Mycoplasma pneumoniae infection, and no abnormal laboratory findings caused by AZT was noticed. The MICs of AZT against 9 strains isolated from patients with pyelonephritis and those with tonsillitis were as follows: MICs against all of 3 strains of K. pneumoniae were less than 0.05 microgram/ml. MICs against 2 out of 4 strains of H. influenzae were less than 0.05 microgram/ml and those of the remaining 2 strains were 0.10 microgram/ml. MIC against 1 strain of S. aureus was 1.56 microgram/ml. MIC against 1 strain of S. epidermidis was more than 100 micrograms/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Recognition of regional hypertrophy in hypertrophic cardiomyopathy using thallium-201 emission-computed tomography: comparison with two-dimensional echocardiography.

The configuration of the hypertrophied myocardium was evaluated by thallium-201 emission-computed tomography and 2-dimensional (2-D) sector scan in 10 patients with obstructive hypertrophic cardiomyopathy (HC), 10 with nonobstructive HC with giant negative T waves and 10 with concentric left ventricular (LV) hypertrophy. Thallium-201 myocardial imaging was reconstructed into multiple 12-mm-thick slices in 3 planes. The thickness ratio of the ventricular septum and the LV posterior wall in the short-axis plane and the ratio of the ventricular septum and the apical wall in the long-axis plane were analyzed. In the patients with obstructive HC the ventricular septal wall thickness index was increased, and the ratio of septal to posterior wall thickness index (1.45 +/- 0.23) was greater than that in the patients with nonobstructive HC with giant negative T waves or in those with concentric LV hypertrophy (1.03 +/- 0.20 and 0.98 +/- 0.11, respectively; p less than 0.01 for each). In the patients with nonobstructive HC with giant negative T waves, increased apical wall thickness with apical cavity obliteration was characteristic, and the ratio of ventricular septal to apical wall thickness index (0.66 +/- 0.14) was less than that in the patients with obstructive HC or in those with concentric LV hypertrophy (1.46 +/- 0.38 and 1.04 +/- 0.09, respectively; p less than 0.001 for each). In contrast, technically satisfactory 2-D sector scanning (83%) demonstrated various configurations of the hypertrophied ventricularseptum, but could not detect apical hypertrophy in 4 of the 10 patients with nonobstructive HC with giant negative T waves whose LV cineangiograms demonstrated apical hypertrophy. Thus, thallium-201 emission-computed tomography is useful in evaluating the characteristics of LV hypertrophy and assists 2-D sector scan, especially in patients with apical hypertrophy in HC.

Adult↗
PubMed1984

Effect of vitreous detachment on vitreous fluorophotometry.

Twenty eyes of 17 normal subjects with or without posterior vitreous detachment (PVD) were examined to investigate the influence of various types of PVD on vitreous fluorophotometric readings. Biomicroscopic examinations of the vitreous body were performed with an El Bayadi - Kajiura preset lens, and the findings were classified according to the extent of vitreous detachment and the position of the posterior hyaloid membrane when the eye was stationary. Equivalent fluorescein concentration profiles along various directions in the vitreous cavity were obtained with vitreous fluorophotometry. The degree of PVD significantly affected the measurements. Close to the retina, fluorescein concentrations were significantly higher when the subhyaloid space was sampled than when the vitreous gel was sampled. Our findings have implications for vitreous fluorophotometric assessment of the permeability of the blood-retinal barrier.

Aged↗