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Biomedical subjects

M Hirose

Publications and source records attributed to M Hirose.

At least 667 records · Page 37Linked to original sources

Characterization of a progestin-binding component in lactating rat mammary glands.

Experiments were carried out to identify progestin-binding receptors in the mammary gland where casein synthesis is known to be inhibited by this hormone. A progestin-binding component with high affinity, low capacity and a sedimentation coefficient of 8.8 S was isolated from the cytosol of lactating rat mammary glands. This component strongly bound [3H]R5020 (17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione) with a dissociation constant of 3.9 . 10(-9) M under low-salt conditions and with that of 8.2 . 10(-10) M in the presence of 0.3 M KCl. Specificity studies showed a high degree of progestin specificity under high salt conditions. In the absence of KCl, binding of [3H]-R5020 was inhibited by unlabeled glucocorticoid in the same degree as unlabeled progestin, but the inhibition by glucocorticoid was greatly diminished by the presence of 0.3 M KCl. These observations suggest that the [3H]R5020-binding-component is the progestin receptor and that its function may be regulated by the concentration of glucocorticoid and salt.

Animals↗

Chronic effects of norharman in rats treated with aniline.

The carcinogenic effects of aniline and norharman given alone or in combination were examined in rats. Neoplastic changes including hyperplastic changes of the urinary bladder were not found in all groups. Papillomas of forestomach were observed in 5 rats out of 110 rats. However, this was not significantly different among the groups. Pyelonephritis or chronic nephritis were also seen in all groups. Hematological and blood biochemical analysis did not show any notable difference in the animals treated with aniline and/or norharman.

Alkaloids↗

Alterations in glucocorticoid receptor conformation by molybdate.

Glucocorticoid receptor activities in cytosol from lactating rat mammary glands were greatly stabilized by molybdate against inactivation during incubation at 25 degrees C. The sedimentation coefficient was 9-10S in the presence of 10 mM Na2MoO4, but 6-7S in the absence of the ion. These data strongly suggest that alterations in receptor conformation induced by direct interaction with molybdate are involved in the stabilization process.

Animals↗

Occurrence of common binding sites for progestin and glucocorticoid in the lactating mammary gland of the rat.

Previous reports have shown that in the cytosol from rat mammary gland, the high affinity binding of glucocorticoid is strongly inhibited by unlabeled progestin and that of progestin is strongly inhibited by glucocorticoid. Experiments were carried out with [3H]dexamethasone and [3H]R5020 to determine whether the binding sites for glucocorticoid and progestin are the same. Thermal inactivation experiments showed that the molecular properties of the [3H]-dexamethasone-binding sites closely resemble those of the [3H]R5020-binding sites. The dissociation constant of the [3H]R5020-receptor complex was almost exactly the same as the inhibition constant of unlabeled R5020 for [3H]dexamethasone-binding sites. The same correlation was observed between the dissociation constant and the inhibition constant of dexamethasone. In addition, no [3H]R5020-binding was observed after saturating the [3H]-dexamethasone-binding sites. These results led us to conclude that common binding sites for [3H]dexamethasone and [3H]R5020 exist in the cytosol from the rat mammary gland. The results of further experiments, including Scatchard analyses and dEAE-cellulose chromatography, strongly suggest that there are at least two classes of [3H]dexamethasone-binding sites, and that one of them binds both glucocorticoid and progestin stably.

Animals↗

[Clinical experience with cefoperazone in the pediatric field (author's transl)].

Cefoperazone (CPZ) was given intravenously to 23 children with the following acute bacterial infections; 10 cases of pneumonia, 4 cases of urinary tract infection, 2 cases of purulent cervical lymphadenitis, 2 cases of pertussis pneumonia, 2 cases of septicemia, 1 case of osteomyelitis, 1 case of perforative peritonitis and 1 case of bacterial meningitis. Clinical effectiveness was obtained in 20 cases out of 23 cases and bacteriological effectiveness in 14 cases out of 17 cases. With CPZ, the following side effects developed; transient diarrhea in 1 case, asymptomatic eosinophilia in 2 cases. From the above clinical results, it is apparent that CPZ is a useful antibiotic for treating pediatric patients with various kinds of bacterial infections.

Age Factors↗

Effect of cyclophosphamide on rat urinary bladder epithelium treated wtih N-butyl-N-(4-hydroxybutyl)nitrosamine.

The effect of cyclophosphamide (CP) on the urinary bladder epithelium of rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) was examined histologically to detect preneoplastic papillary or nodular hyperplasia. The urinary bladder epithelium of rats injected intraperitoneally with 40 or 80 mg/kg body weight of CP after treatment with 0.025% BBN for 2 weeks showed extensive epithelial erosion and then simple, or papillary or nodular hyperplasia, but this soon almost disappeared. In contrast, rats given BBN alone showed papillary or nodular hyperplasia later. These findings indicate that epithelial damage by CP inhibited the early neoplastic process of BBN.

Animals↗

Effects of sodium saccharin and caffeine on the urinary bladder of rats treated with n-butyl-n-(4-hydroxybutyl)nitrosamine.

The effects of sodium saccharin and caffeine on urinary bladder carcinogenesis in Wistar strain rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) were studied. Animals were given 0.01% BBN as an initiator for 4 weeks and then sodium saccharin and/or caffeine as promoters for 32 weeks (Experiment I), or were treated simultaneously with 0.001% BBN, sodium saccharin and/or caffeine for 40 weeks (Experiment II). The urinary bladders were then removed and examined by light and electron microscopy. Sequential administration of sodium saccharin after BBN significantly enhanced the induction of hyperplasias compared with administration of BBN alone (Experiment I), and simultaneous administration of sodium saccharin with BBN significantly enhanced the induction of hyperplasia and papillomas compared with BBN alone (Experiment II). Two types of hyperplasias developed in the urinary bladder of rats treated with sodium saccharin alone in both experiments. Caffeine alone had no effect on the rat urinary bladder epithelium, and either sequential or simultaneous administration of caffeine with BBN caused no marked enhancement of carcinogenesis in these experiments.

Animals↗

Enhancing effect of inducers of liver microsomal enzymes on induction of hyperplastic liver nodules by N-2-fluorenylacetamide in rats.

The effects of inducers of liver microsomal enzymes on the induction of hyperplastic liver nodules by N-2-fluorenylacetamide (2-FAA) were studied in male F344 rats. The rats were fed a diet containing 200 ppm 2-FAA for 2 weeks and then given test chemicals for the following 8 weeks. Partial hepatectomies were performed at the end of the third week of the experiment. The compounds were tested, and their concentrations (in ppm) in the diet were as follows: 1,000 polychlorinated biphenyls (PCB), 500 PCB, 500 PCB plus 70 3-methylcholanthrene (MCA); 500 PCB plus 500 phenobarbital, 70 MCA, 500 phenobarbital, 500 phenobarbital plus 500 beta-naphthoflavone, and 2,500 3-(3,5-dichlorophenyl)-5,5-dimethyloxazoline-dione-2,4 (DDOD). All experimental groups developed significantly greater numbers and total areas of hyperplastic nodules than did the controls. In groups treated similarly with the test chemicals but without partial hepatectomy, the numbers and total areas of hyperplastic nodules were significantly less than those in the experimental groups with partial hepatectomy. Administration of test chemicals except 2-FAA to partially hepatectomized rats did not induce hyperplastic nodules. The present results showed the early detection of the enhancing effect on induction of hyperplastic liver nodules by a system consisting of the following three procedures: 1) 2-FAA feeding; 2) administration of test chemicals, and 3) partial hepatectomy during administration of test chemicals. In this system DDOD enhanced the induction of hyperplastic nodules of the liver.

2-Acetylaminofluorene↗

Carcinogenic effect of N-ethyl- and N-amyl-N-nitrosourethans on female Donryu rats.

Carcinogenic effect of N-ethyl-N-nitrosourethan (ENUR) and N-amyl-N-nitrosourethan (ANUR) was examined by continuous oral administration or topical application to female Donruy rats. Oral administration of 100 ppm solution of ENUR induced 100% of tumors in the forestomach, 46%, 80%, 71%, and 51% in the oral cavity and pharynx, esophagus, duodenum, and liver, respectively. On the other hand, the incidence of forestomach tumors was 78%, that of oral cavity and pharynx, and esophagus was 93% and 98%, respectively, in rats given 400 ppm suspension of ANUR. In addition, topical application of ENUR induced tumors of the skin as well as tumors of the forestomach and liver.

Administration, Oral↗