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Biomedical subjects

O Ishihara

Publications and source records attributed to O Ishihara.

At least 37 records · Page 2Linked to original sources
PubMed1994

New reconstruction for total maxillectomy defect with a fibula osteocutaneous free flap.

The osteocutaneous fibula free transfer with three segments of bone and the peroneal flap was used to reconstruct a total unilateral maxillectomy defect. Satisfactory restoration of three-dimensional facial structure, orbital support, and prosthesis wearing was achieved. The fibula osteocutaneous free flap is a very useful alternative for reconstructing a maxillectomy defect.

Bone Transplantation↗
PubMed1994

[Risks and benefits of gonadotrophin therapy for infertile patients with ovulatory cycles].

In an attempt to evaluate the risks and benefits of human menopausal gonadotrophin (hMG) therapy for patients with unexplained infertility, the response and outcome of hMG therapy for anovulatory patients and ovulatory patients with unexplained infertility were analyzed in a group of successful cases of pregnancy. The number of follicles grown and the total doses of hMG were not significantly different in the two groups. The rate of spontaneous abortion in unexplained cases was twice as high (13.2%) as in anovulatory cases. However, the rate of multiple pregnancy was 8.8% for unexplained cases which was significantly lower than that for anovulatory cases (39.0%). In addition, ovarian hyperstimulation syndrome (OHSS) occurred in 11.8% of unexplained cases and that was much lower than that for anovulatory cases (25.8%). This study justifies the application of gonadotrophin therapy to ovulatory patients with unexplained infertility in terms of the risks and benefits of the therapy in achieving pregnancy.

Adult↗
PubMed1993

[Gonadotrophin-releasing hormone agonist in the treatment of hypogonadotrophic secondary amenorrhoea].

In an attempt to induce ovulation in Clomiphene resistant secondary amenorrhoea patients, the gonadotrophin-releasing hormone agonist (Buserelin) (600-900 micrograms/day) was administered in 13 cases aged 18 to 24 years for one week from day 5 of the menstrual cycle. Serum levels of luteinizing hormone increased in all patients, and estradiol levels increased in 10 of 13 patients in response to Buserelin. However, ovulation was observed in 6 cases, and the response to Clomiphene was recovered in all of these 6 cases in their subsequent menstrual cycles. These results imply the existence of a subgroup who respond to Buserelin in Clomiphene resistant secondary amenorrhoea patients and a possible new approach for the treatment of secondary amenorrhoea.

Adolescent↗
PubMed1993

Synthesis of 12-hydroxyeicosatetraenoic acid by human endometrium and decidua.

In order to clarify the possible involvement of lipoxygenase metabolites of arachidonic acid (AA) in implantation, monohydroxylic acid production was examined using human endometrium and decidua in early pregnancy. As 14C-AA was mainly converted to 12-hydroxyeicosatetraenoic acid (12-HETE) as well as prostaglandins (PGs) by the microsomal fraction of the endometrium, a subsequent study was carried out on the endometrium (at various stages) and decidua in early pregnancy using tissue incubation and high performance liquid chromatography (HPLC) analysis for 12-HETE. The amounts of 12-HETE released into the culture medium by proliferative and secretory endometrium were 165.1 +/- 123.4 (ng/mg.protein/24 h, mean +/- SD) and 502.3 +/- 127.2, respectively, whereas, decidua produced a smaller amount of 12-HETE that declined as gestation progressed. This lipoxygenase product as well as PGs might have a role in implantation.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1992

Interleukin-1 beta stimulates decidual stromal cell cyclo-oxygenase enzyme and prostaglandin production.

The cytokine interleukin-1 (IL-1 beta) increased prostaglandin production by decidual stromal cells in culture in a time and dose dependent manner. Optimum conditions for stimulation were found to be for 24 hours at a concentration of 100 pg IL-1 beta/ml. An apparent increase in cyclo-oxygenase enzyme synthesis accompanied the increase in prostaglandin production, and both changes were inhibited by the protein synthesis inhibitor cycloheximide. This implicates protein synthesis in the stimulatory effects of IL-1 beta, which may be mediated through the increase in cyclo-oxygenase enzyme. A pre-incubation period of 72 hours was found to be necessary to observe the stimulatory effect of IL-1 beta on prostaglandin production, but this did not seem to be due to any change in the sensitivity of the cells to IL-1 beta; the increase in the number of cyclo-oxygenase positive cells was the same if IL-1 beta was added on day 1, day 2 or day 3 of culture, even though prostaglandin production was not stimulated on day 1 or day 2. Cycloheximide increased prostaglandin production on the first two days of culture and had no effect on the third day of culture. This was interpreted as indicating that a factor inhibiting cyclo-oxygenase activity was synthesised during the initial period of culture, which prevented any increase in prostaglandin production following the increase in enzyme synthesis.

Cycloheximide↗
PubMed1992

Changes in decidual stromal cell function associated with labour.

OBJECTIVE: To determine whether decidual cells produce altered levels of prostaglandins after labour. DESIGN: Decidual stromal cells and macrophages were isolated before and after labour, and the production of prostaglandins E2 and F2 alpha measured. Changes in the numbers of cyclooxygenase enzyme positive cells were assessed by immunocytochemistry. RESULTS: Decidual stromal cells obtained after labour produced 30 times more prostaglandins E2 and F2 alpha in culture than cells obtained before labour. The increased production persisted for up to 72 h of culture, and was associated with an increase in the numbers of cyclooxygenase-positive cells from less than 5% to greater than 95%. No changes in macrophage function were observed. CONCLUSION: Increased levels of prostaglandins E2 and F2 alpha were released from decidual stromal cells after labour, suggesting that these cells may be an important source of prostaglandins in labour.

Decidua↗
PubMed1991

A comparison of two populations of decidual cells by immunocytochemistry and prostaglandin production.

The decidua has been implicated in the control of human labour, particularly through changes in prostaglandin production, but this tissue contains a number of different cell types. A density gradient system was used to obtain two populations of cells from term human decidua, and these populations were characterised. The more dense cells (population B) was a mixed population, predominantly macrophages (80%), but small numbers of T- and B-lymphocytes were also present, as identified by immunocytochemistry. Most of these cell types also contained detectable levels of cyclooxygenase enzyme. The less-dense cell population (population A) did not contain significant numbers of the above cell types and released prolactin, suggesting that they were decidual stromal cells. This preparation of decidual stromal cells may be of use in defining the functions of these cells in labour.

Antibodies, Monoclonal↗
PubMed1991

Morphogenesis of the cornoid lamella: histochemical, immunohistochemical, and ultrastructural study of porokeratosis.

To elucidate the morphogenesis of cornoid lamellae (CL) in porokeratosis, skin lesions of three cases of disseminated superficial actinic porokeratosis and a case of linear porokeratosis were examined. By N-(7-dimethylamino-4-methyl-3-coumarinyl)maleimide staining, SH groups were present in the living layer of the epidermis beneath CL and irregularly disappeared at the bottom of CL, whereas SS linkages appeared in dyskeratotic cells in the living layer and in the irregularly shaped cell membranes of the horny cells. Epidermis beneath CL showed an increased and irregular involucrin expression. Ultrastructurally, the living keratinocytes contained many cytoplasmic vacuoles and had a smaller number of lamellar bodies than normal. Intercellular lamellar sheets were incompletely formed. The dyskeratotic cells and the lower horny cells contained many small vacuoles but formed a marginal band. The horny cells of CL also formed a marginal band and, further, a keratin pattern. CL may be formed by hyperproliferative atypical kertatinocytes which keratinize rapidly and irregularly and show defective desquamation due to the paucity of intercellular lamellar sheets.

Aged↗
PubMed1991

Differential metabolism of intracellular and extracellular arachidonic acid by decidual stromal cells and macrophages.

Term decidual stromal cells metabolized extracellular arachidonic acid to cyclo-oxygenase, lipoxygenase and epoxygenase products. Prostaglandins were the major metabolites from extracellular arachidonic acid. In contrast, intracellular arachidonic acid was metabolized mainly to an epoxygenase product, together with some lipoxygenase products. Decidual macrophages showed similar results, though these cells had higher production rates per cell of most metabolites. The calcium ionophore A23187 increased the levels of arachidonic acid released from the intracellular stores of decidual stromal cells and had variable effects on the production of cyclo-oxygenase, lipoxygenase and epoxygenase metabolites. Less than 15% of the total metabolites released from A23187-stimulated cells were cyclo-oxygenase products, which suggested that the cyclo-oxygenase products released by decidual stromal cells or macrophages may be mainly derived from extracellular arachidonic acid. This implies that the regulation of decidual cyclo-oxygenase may have a major role in determining prostaglandin output from this tissue.

Arachidonic Acids↗
PubMed1991

Differences of metabolism of prostaglandin E2 and F2 alpha by decidual stromal cells and macrophages in culture.

Intact decidual stromal cells and macrophages metabolized 3H-prostaglandins E2 and F2 alpha although the rate of metabolism of both prostaglandins was higher in the decidual macrophages than in decidual stromal cells. PGE2 was metabolised mainly to 13,14-dihydro-15-keto-PGE2 together with smaller quantities for PGB2 and 13,14-dihydro-15-keto-PGA2, whereas PGF2 alpha was metabolised to 13,14-dihydro-15-keto-PGF2 alpha, PGE2 and PGB2, and it seems that similar metabolic pathways were present in both cell types. The half-lives of both prostaglandins (8.8 +/- 3.4 h for PGE2 and 15.0 +/- 8.2 h for PGF2 alpha sigma in the presence of decidual stromal cells show that during incubations lasting more than a few hours significant metabolism of prostaglandins, especially PGE2, will occur, and that this must be allowed for in any assessment of total prostaglandin production by cultured decidual cells. One of the 6 tissue samples examined metabolised both prostaglandins very rapidly, such that the half-lives were less than 2 h. This may be the result of the presence of very high levels of metabolic enzymes, since the overall pattern of metabolites was similar to that from the other 5 samples.

Cells, Cultured↗
PubMed1990

An inhibitor of prostaglandin biosynthesis from human decidua: partial purification and properties.

An inhibitor of prostaglandin synthetase which catalyzes the conversion of arachidonic acid into prostaglandin E2 was partially purified from the 105,000 x g supernatant fraction of the human decidual cell homogenate. By means of ammonium sulfate fractionation, Mono Q ion-exchange chromatography, and gel filtration chromatography, the inhibitor was purified about 15-fold, giving a preparation with a molecular weight of 55-60 KDa. The 50% inhibitory concentration of the purified substance was approximately 0.2 mg/ml. The inhibitor may play a role in suppression of prostaglandin production by decidua in early pregnancy.

Animals↗
PubMed1989

Creutzfeldt-Jakob disease in Japan: an epidemiological study done in a select prefecture between 1976 and 1986.

An epidemiological study was performed with respect to Creutzfeldt-Jakob disease in a designated area in Japan. The subjects were observed in a small rural prefecture where the population generally remains within a limited radius throughout their lives. The patients' life-styles in each area were investigated in detail. Nine cases appeared in 11 years; 6 were definitive and 3 probable. They were all of the subacute type; there were no noteworthy sexual differences, age of onset, course and/or past histories. Three of the nine cases came from two families; the relationship between familial and isolated cases was examined. Revealed facts and time-space clustering were investigated statistically, but no indication of natural transmission was observable.

Aged↗
PubMed1988

Is postoperative radiotherapy or maintenance chemotherapy necessary for carcinoma of the uterine cervix?

The effectiveness of postoperative radiotherapy and adjuvant chemotherapy was examined for patients with uterine cervical squamous cell carcinoma. Whole pelvis irradiation is unnecessary for patients with less than 2/3 of depth of cervical local involvement without pelvic regional lymph node metastases. Adjuvant chemotherapy with tegafur [1-(2-tetrahydrofuryl)-5-fluorouracil] (600 mg/day) has failed to improve the survival of patients with positive lymph node metastases.

Carcinoma, Squamous Cell↗