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Biomedical subjects

O Ishihara

Publications and source records attributed to O Ishihara.

At least 19 recordsLinked to original sources
PubMed1995

Functional reconstruction of a bilateral maxillectomy defect using a fibula osteocutaneous flap with osseointegrated implants.

We have achieved functional reconstruction for a bilateral upper alveolar bone, gingival, and palatal defect that has various problems originating from instability of the prosthesis using the fibula osteocutaneous flap with osseointegrated implants. The flap had three bone segments and two skin paddles. The combined bone segments created the upper alveolar arch, and the skin paddles closed the palatal defect. Nine months later, prosthodontic treatment was performed successfully. Our procedure restored the patient to masticatory function of the upper jaw, intelligible speech, and natural facial appearance. As a result, quality of life of the patient was extremely improved.

Dental Implantation, Endosseous↗
PubMed1995

[A case of ovarian malignant Sertoli-Leidig cell tumor treated with CBDCA, etoposide and epirubicin chemotherapy].

A 49-year-old female presented with a low abdominal tumor. Before operation, she had neither evidence of androgen excess nor abnormal tumor marker values, but US, CT and MRI findings strongly suggested the possibility of a malignant ovarian tumor. Her operative findings were as follows: a goose egg-sized main tumor in the low abdomen, with a walnut-sized tumor in the right side, which grew around the right ureter, causing right non-functional kidney. Pathological examination revealed her tumor was a very rare type of malignant Sertoli-Leidig cell tumor with pelvic lymph nodes metastases. Most patients with this disease usually have good prognoses, but with metastasis or recurrence, no therapy is as effective as in epithelial ovarian cancer. In this case, we selected a new combination chemotherapy of CBDCA, Etoposide and Epirubicin, considering current changes in the chemotherapy for ovarian germ cell tumors and Sertoli-Leidig cell tumors of testis. Now, 1 year and 4 months after operation, she has no evidence of recurrence or metastasis. This study proposes a new, presumably more effective chemotherapy for an ovarian malignant Sertoli-Leidig cell tumor.

Antineoplastic Combined Chemotherapy Protocols↗
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↗
PubMed1987

The inhibitory effect of cytosolic fraction of human decidua on prostaglandin synthesis.

To elucidate the mechanism of suppression of prostaglandin (PG) production in decidua in early pregnancy, the PG synthetase activity of decidua and mid-secretory endometrium was studied. The microsomal fractions and their supernatants were prepared from the tissue by ultracentrifugation at 105,000 g. The standard incubation mixture consisted of the microsomal fraction and 14C arachidonic acid with cofactors, with incubation being carried out for 10 minutes at 37 degrees C. After extraction, the radioactivity of PGE2 was measured and PG synthetase activity was assayed. The apparent Km value for PG synthetase in decidua was 4.6 +/- 0.14 x 10(-6) M (n = 4), whereas that in endometrium was 4.6 +/- 1.18 x 10(-6) M (n = 3). Subsequently, kinetic studies on PG synthetase inhibitor in decidua were carried out. When sheep seminal vesicle was used as an enzyme source, the decidual supernatant showed competitive inhibition. The inhibitory substance in decidua was inactivated after incubation for 15 minutes at 65 degrees C. It seems likely that the suppression of PG biosynthesis in human decidua in early pregnancy is not due to the difference in PG synthetase found in decidua and in endometrium, but due to the existence of PG synthetase inhibitor in decidua.

Cell Extracts↗
PubMed1986

Metabolism of arachidonic acid and synthesis of prostanoids in human endometrium and decidua.

Arachidonic acid metabolism and prostanoid synthesis were investigated using [14C]-arachidonic acid (AA) in human endometrium obtained at different phases of the ovarian cycle and decidua in early pregnancy. Prostaglandins (PG) identified in endometrium and decidua were PGE2 and PGF2 alpha. The capacity for the production of PGE2 and PGF2 alpha was higher in the secretory phase of endometrium than in the proliferative phase, and the maximum formation of PGE2 and PGF2 alpha was found in the mid secretory phase and in the late secretory phase, respectively. However, the production of PGs was markedly suppressed in decidua. On the other hand, more than 70% of [14C]AA was incorporated into total neutral lipids, whereas less than 22% was incorporated into glycerophospholipids in both endometrium and decidua. Secretory endometrium showed a higher uptake of [14C]AA into glycerophospholipids than did proliferative endometrium, whereas the incorporation into neutral lipids was lower in secretory endometrium than in the proliferative phase. Moreover, decidua showed a similar pattern of incorporation of [14C]AA to the proliferative phase. The changes of arachidonic acid metabolism and PG formation in both endometrium and decidua are discussed in terms of implantation and maintenance of early pregnancy.

Arachidonic Acid↗
PubMed1986

[A case of primary malignant fibrous histiocytoma of the vagina].

A 52-year-old woman visited us complaining of a recurrent vaginal tumor, which was diagnosed histologically as malignant fibrous histiocytoma of the vagina. Computed tomography revealed multiple metastatic lesions in the liver, lymph nodes and vertebrae. The patient was treated with combination chemotherapy consisting of cyclophosphamide, adriamycin and cis-platinum, but the tumor did not yield readily to the treatment. We believe that this is the first reported case of this tumor in this location in Japan.

Antineoplastic Combined Chemotherapy Protocols↗