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Biomedical subjects

H Okada

Publications and source records attributed to H Okada.

At least 1,243 records · Page 69Linked to original sources
PubMed1979

[Spontaneous regression of a posterior fossa dural arteriovenous malformation (author's transl)].

A 29-year-old woman was admitted to our hospital because of dizziness, nausea and convulsive seizure. She complained of left sided tinnitus. Neurological examination revealed right homonymous hemianopsia, and systolic murmur on the left retroauricular area. Angiograms revealed a dural AVM in the left posterior fossa. Feeders of AVM were enlarged left occipital artery and middle meningeal artery. Since then she was treated only conservatively, but angiograms performed two years and one month later showed disappearance of the dural AVM. She experienced no head trauma, and no subarachnoidal hemorrhage. She has never been treated by irradiation nor contraceptives. We could find no clear mechanism for the spontaneous regression of the AVM.

Adult↗
PubMed1978

[The effect of enzymes on progesterone-receptor binding and chromatin binding of the complex in the estrogen-primed rabbit uterus (author's transl)].

The present study was designed to determine the characteristics of the progesterone receptor and chromatin binding site ("acceptor") of the progesterone-receptor complex in the rabbit uterus. The uterus was obtained from an estrogen-primed immature female rabbit. The binding of progesterone to the uterine receptor was examined in vitro. The progesterone-receptor binding was reduced only by proteases, and phosphorus moiety may not be related for progesterone-receptor binding. The effects of enzymes on the acceptor of the chromatin were investigated. The progesterone-receptor complex was bound to the dehistonized chromatin. The dehistonized chromatins, which were pretreated with enzymes at 4 degrees C or 37 degrees C for 30 minutes, were incubated with 3H-progesterone prelabeled uterine cytosol at 4 degrees C for 30 minutes, and the radioactivity in the chromatin pellet was counted. Proteases effectively decreased the receptor binding capacity to the dehistonized chromatin in the following order: pronase greater than trypsin greater than papain greater alpha-chymotrypsin. DNAse moderately and phospholipase A slightly decreased its binding capacity. The results may indicate that the acceptor site of the progesterone receptor is nonhistone protein over DNA of chromatin and may contain phosphorus moiety.

Animals↗
PubMed1978

Nonspecific activation of complement by leukemic cells.

Non-specific activation of complement (NAC) on cell membranes via the alternative pathway was studied by using leukemic cells and cells from a generalized reticulohistiocytosis. The cells were treated with normal human serum in veronal-buffered saline containing ethyleneglycoltetraacetrate and MG++. Since human erythrocytes (HuE) are known to adhere to complement-reacted cell membranes in an immune adherence reaction, complement activation on the cell membrane was confirmed by the rosette formation of HuE which is due to the generation of C3b molecules on the cell membrane. Only cells from Schilling-type acute monocytic leukemias and cells from a generalized reticulohistiocytosis possessed NAC ability. All other leukemic cells tested, as well as normal hematopoietic and lymphoreticular cells, were NAC-negative. Furthermore, none of the mitogens tested generated NAC ability on normal peripheral blood lymphocytes.

Bone Marrow Cells↗
PubMed1978

Effect of hydrophobicity of acyl groups on the activity and stability of acylated thermolysin.

1. Normal carboxylic acids of different hydrophobicities and similar chain lengths were prepared and used for the modification of amino groups of thermolysin (EC 3.4.24.4). They were 4,7,10,13-tetraoxatetradecanoic acid, 4,7,10-trioxatetradecanoic acid, 4,7-dioxatetradecanoic acid and 4-oxatetradecanoic acid. 2. The modified enzymes were isolated by gel filtration. They had 6--7 acyl groups per molecule. Acylation of amino groups with 4-oxatetradecanoic acid and tetradecanoic acid made the enzyme insoluble. 3. The most hydrophilic enzyme derivative had similar enzyme activity and higher heat resistance than the native enzyme. The most hydrophobic derivative showed lower Km (50%) and V (40%) values for proteinase activity and lower heat resistance than the former derivative. The trioxa-derivative had intermediate characteristics. The results are discussed with respect to effects on stability and activity of the enzyme.

Acylation↗
PubMed1978

Enhancement of bioavailability of a hydrophobic amine antimalarial by formulation with oleic acid in a soft gelatin capsule.

The relative availability of the orally administered hydrophobic antimalarial alpha-(dibutylaminomethyl)-6,8-dichloro-2-(3',4'-dichlorophenyl)-4-quinolinemethanol (I) from two dosage forms was determined in beagle dogs. Compound I was soluble in oleic acid to the extent of 23.5% (w/w), and oleic acid was suitable for encapsulation in soft gelatin capsules. The availability of I formulated as its hydrochloride salt in a standard hard gelatin capsule formulation was significantly lower than that of I formulated in a soft gelatin capsule with oleic acid as the solvent. A 20% solution of I in oleic acid (soft gelatin capsules) maintained at 23 degrees provided 4% of the oleic acid ester of I iwithin 1 month. Further reaction, however, was not seen over 2 years.

Animals↗
PubMed1978

Preliminary studies on streoid-binding proteins in human testes of testicular feminization syndrome.

This study was designed to detect either 5alpha-dihydrotestosterone (DHT) or 17beta-estradiol (E2)-binding protein in the testes of a 1-year-old patient with testicular feminization syndrome (TFS) and in the testes of patients with prostatic cancer. Sucrose gradient analyses revealed E27S protein binding (but no such 7S protein binding of DHT) in the testes of the patient with TFS, but both E2 and DHT 7 S protein binding was observed in normal senile testes. The dissociation constants (Kd) were measured by charcoal adsorption. The Kd of E2 protein binding in both testes of different status was approximately 1.3 x 10(-9) M, and the Kd of DHT protein binding was 2.0 x 10(-9) M in the senile testes. A ligand specificty study indicated characteristics of both E2 and DHT receptors in the senile testes. It is speculated that a deficiency of androgen receptor and the presence of estrogen receptor in the testes of patients with TFS lead to insensitivity to androgen as a result of the androgen receptor deficiency and to sensitivity to estrogen as a result of the presence of the estrogen receptor.

Androgen-Insensitivity Syndrome↗
PubMed1978

The adrenal response to exogenous adrenocorticotrophin in patients with infections due to Neisseria meningitidis.

The adrenal response to a soluble form of beta1-24-corticotropin (tetracosactrin [ACTH]: 250 microgram administered intramuscularly) was studied in 28 patients with meningitis due to Neisseria meningitidis (21 with petechiae and seven without) and in six patients with Salmonella typhi bacteremia. Six normal subjects also were tested for adrenal responsiveness at four different times of the day (8 A.M., 12 noon, 4 P.M., and 10 P.M.) and served as controls. The results showed that, whatever the time of testing, patients with meningococcal infections and typhoid fever had unstimulated (basal) levels of plasma cortisol above the 99% confidence limits for the mean unstimulated cortisol levels for the normal subjects. Furthermore, although patients with meningitis without petechiae and subjects with S. typhi bacteremia responded to ACTH stimulation in a manner similar to that of the normal subjects, most subjects with meningitis with petechiae did not have increased levels of plasma cortisol after treatment with ACTH. This lack of response could not be ascribed entirely to the higher basal levels of plasma cortisol in these patients. Patients with meningitis associated with petechiae may have a relatively decreased adrenal response to stimulation with exogenous ACTH.

Adolescent↗
PubMed1978

Steroidal control mechanism of cell proliferation in mouse uterine epithelium.

The percentage of labeled cells in the uterine luminal epithelium of cycling mice showed the different zonal distributions at each stage of estrous cycle after cumulative labeling with 3H-thymidine for 36 hr. It was estimated that the proliferating fraction in the epithelium at proestrus, estrus, metestrus, and diestrus was 100%, 100%, 40% and 5%, respectively. The percentage of labeled cells in the uterine luminal epithelium of cycling mice treated with progesterone remained below 10% level for at least 20 hr after injections of progesterone. Total labeling was attained in the uterine epithelium of castrated mice by the administration of estradiol-17beta. On the other hand, the cell proliferation in the uterine epithelium of castrated mice treated with estradiol and progesterone was markedly suppressed and the percentage of labeled cells remained approximately at 35%. The remaining cell population, however, still showed the mitotic potency when mice received estradiol. It is suggested from this study that the effect of progesterone is to suppress the epithelial cell proliferation and transfer cells into resting cell fraction which is still evoked to proliferate as the effect of estradiol and that a key factor controlling epithelial proliferation in mouse uterus during the estrous cycle is proliferating fraction rather than cell cycle time.

Animals↗
PubMed1978

In vivo interaction between steroidal alkylating agents and oestrogen receptors in rabbit uteri.

The binding of steroidal alkylating agents to specific tissue component is necessary for the selective distribution of these compounds to their target tissues. The in vivo interaction of Estracyt or NSC-112259 with oestrogen receptors may play an important role in their action mechanism. Both Estracyt and NSC-112259 which were administered in vivo, gradually reduced the binding of [3H] oestradiol to cytoplasmic oestrogen receptor in rabbit uteri. From this, it was suggested that a negligible amount of oestradiol was released from these compounds and that the oestradiol moiety was useful as a carrier for the nitrogen mustard moiety. And it appeared that the synthesis of a new receptor protein was inhibited by the nitrogen mustard moiety, thereby causing a decrease in the cytoplasmic oestrogen receptor level.

Animals↗