Biomedical subjects

H Okamura

Publications and source records attributed to H Okamura.

At least 667 records · Page 37Linked to original sources

PubMed1985

Sarcoma-like mural nodules combined with a microfocus of anaplastic carcinoma in mucinous ovarian tumor.

A case of mucinous ovarian tumor with sarcoma-like mural nodules, one of which coexisted with a microfocus of anaplastic carcinoma, was studied by light, electron microscopic, and histochemical examinations. The case suggested that the formation of sarcoma-like mural nodules may be the result of the proliferation of undifferentiated mesenchymal cells which exist beneath the mucinous epithelium by some stimulation like hemorrhage in the cyst wall. Histologically, the mononucleated cells composing the sarcoma-like mural nodules had epithelioid characteristics, particularly at the areas where the covering mucinous epithelium had already detached. The case also suggested that the findings of epithelioid characteristics in the sarcoma-like mural nodules themselves do not imply these nodules to be anaplastic carcinoma, but merely an epithelioid differentiation from undifferentiated mesenchymal cells, namely one of reactive products. However, the existence of a microfocus of anaplastic carcinoma combined with the sarcoma-like mural nodule necessitates a careful histologic analysis of mural nodules for the treatment of patients and the determination of the prognosis.

Adenocarcinoma, Mucinous↗

PubMed1985

Ultrastructural study of cultured smooth muscle cells from uterine leiomyoma and myometrium under the influence of sex steroids.

Upon the hypothesis that the differentiation or development of smooth muscle cells in both myometrium and leiomyomas may be under the regulation of sex steroids, myometrial and myoma cells were cultured in the presence of sex steroids and their morphological changes were studied ultrastructurally. The cells from the explants of both leiomyoma and myometrium at the 14th day in either control or E (10(-8) M 17-beta-estradiol)-added medium showed extremely well-developed cytoplasmic organelles with few filaments located at the marginal portion of the cytoplasm. These ultrastructural features resembled those of a dedifferentiated stage of smooth muscle cells in vitro. At the 21st day, these cells showed a moderate number of cytoplasmic filaments with dense bodies. These ultrastructural features resembled those of a redifferentiated stage of smooth muscle cells in vitro. In both E- and P (10(-7) M progesterone)-added medium, the cultured smooth muscle cells from both leiomyoma and myometrium showed an increased number of myofilaments with dense bodies even at the 14th day to the 21st day of culture in comparison to the cells either in control or estrogen-added medium. Therefore, the cultured smooth muscle cells in the medium with E and P lacked their dedifferentiated phase in vitro and/or the differentiation or maintenance of their filaments might be under the influence of both estrogen and progesterone. On the observation that the cultured smooth muscle cells from both leiomyoma and myometrium showed very similar ultrastructural changes under the influence of sex steroids, it was suggested that leiomyoma may have the same progenitor cells as myometrium.

Adult↗

PubMed1985

Immunohistochemical investigations of gut hormones in the colon of patients with Hirschsprung's disease.

The distributions of gut hormones in the colon of Hirschsprung's disease were investigated by the peroxidase-antiperoxidase (PAP) immunohistochemical method. Three colonic segments (ganglionic, oligoganglionic, and aganglionic) were stained by the unlabeled antibody enzyme method. The immunoreactivity of vasoactive intestinal polypeptide (VIP) was found to be reduced in the oligoganglionic and aganglionic segments. Antisera to substance P and met-enkephalin demonstrated immunoreactive cells and fibers in the ganglionic segment, whereas these cells and fibers were almost completely absent in the oligoganglionic and aganglionic segments. A similar distribution was seen for the mucosal endocrine cells with somatostatin immunoreactivity. Antisera to neurotensin, motilin, bombesin, and cholecystokinin revealed no immunoreactivity in the normal colon or the three segments. The differences in these peptides between normal and impaired colonal segments may be one of the causes of colon constriction in Hirschsprung's disease.

Adult↗

PubMed1985

Reconstruction of the carotid artery in radical neck dissection.

No permanent cure of head-and-neck cancer can be expected when the cancer infiltrates into the wall of the carotid artery. When the carotid artery was resected, the resultant hemiplegia poses very difficult postoperative rehabilitation problems, even though the cancer is eradicated. The recent development of vascular surgery has made reconstruction of the carotid artery feasible. In this paper, the authors reported the indications of reconstruction of the carotid artery in radical neck dissections and the surgical procedures. The indication of reconstruction of the carotid artery is determined by using of angiography, CT-scan and echography. Especially, echography is useful for determining the possibility of reconstructing the carotid artery. In the case of the infiltration type, we can start to remove tumor after preparing for the reconstruction of the carotid artery. The principle of surgical procedures consists of by-pass shunt with a vascular graft between the common and internal carotid arteries, excision of the artery with tumor and insertion of a vascular graft with end-to-end anatomoses. Concerning the selection of a vascular graft, an auto-vein graft is preferable to a synthetic graft in consideration of the postoperative patency of the vascular flow. Moreover, in the case of reconstructing the artery, preoperative irradiation has often been applied and a wide removal of the soft tissue is required, so it is recommended that the myocutaneous flap be used to cover the reconstructed area.

Blood Vessel Prosthesis↗

PubMed1985

Cellular mechanisms in in vivo production of gamma interferon induced by lipopolysaccharide in mice infected with Mycobacterium bovis BCG.

Infection of mice with Mycobacterium bovis BCG sensitizes them for immune induction of interferon (IFN)-gamma by specific antigen. These mice were found also to respond to lipopolysaccharide (LPS) and concanavalin A (Con A) with high level production of IFN-gamma in the circulation, which was not observed in control mice. In this study, we compared the IFN-gamma response to LPS with that to Con A in an attempt to clarify the cellular mechanisms responsible for in vivo LPS-induced IFN-gamma production. Consequently, (i) the responses to LPS and Con A differed in the kinetics, that to LPS having a longer lag period. (ii) Spleen cells taken from infected mice produced little IFN-gamma in response to LPS, but they showed a higher IFN-gamma response to Con A than those from control mice. (iii) By treating infected mice with immunosuppressive drugs or antibodies to T and natural killer cells before challenge with the inducers, it was indicated that different cellular systems are involved in the IFN-gamma responses to LPS and to Con A.

Animals↗

PubMed1985

Effect of various agents on ovarian plasminogen activator activity during ovulation in pregnant mare's serum gonadotropin-primed immature rats.

The plasminogen activator/plasmin synthetic substrate S-2251 was used to measure the effect of indomethacin, cycloheximide, colchicine, dexamethasone, tranexamic acid, and aprotinin on the elevation of ovarian plasminogen activator (PA) that normally occurs during ovulation in the rat. Young Wistar rats were weaned on the morning of Day 21, given 4.0 IU of pregnant mare's serum gonadotropin (PMSG) s.c. at 0800 h on Day 22, and given 10.0 IU of human chorionic gonadotropin (hCG) on Day 24. These animals normally began ovulating between 0000 and 0200 h on Day 25. The induced ovulation rate was 11.5 +/- 2.2 ova/rat, based on the number of ova in the oviducts of control animals at 0900 h on Day 25. In the controls, PA activity in extracts of homogenized ovaries increased 3-fold from 0.125 +/- 0.010 OD units just before the administration of hCG to 0.371 +/- 0.021 at 12 h after hCG, i.e., near the time of ovulation. Indomethacin, in doses of 0.1-1.0 mg/rat, inhibited ovulation but did not inhibit the normal increase in PA activity, whereas indomethacin at the high dose of 10.0 mg/rat inhibited both ovulation and PA activity. Cycloheximide, at a dose of 0.1 mg/rat, was given at 12 h before hCG, immediately after hCG, and at 9 h after hCG. This agent inhibited ovulation most effectively when given at 12 h before hCG, yet it inhibited PA activity most effectively when given immediately after or at 9 h after hCG. Colchicine, at a dose of 0.1 mg/rat, inhibited ovulation, but not PA activity, when it was given 1 h before hCG.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1985

Immunomodulating activities of staphylococcal enterotoxins. I. Effects on in vivo antibody responses and contact sensitivity reaction.

The immunomodulating effects of staphylococcal enterotoxins on in vivo immune responses in C57BL/6 mice were examined. Of the five serological types A (SEA), B, C, D, and E (SEE), only SEA and SEE markedly suppressed the antibody response to sheep red blood cells (SRBC) when injected 1 day before or on the day of immunization with SRBC. Further study of SEA revealed that it did not affect the antibody response to a thymus-independent antigen, salmonella flagella, but did affect the T-cell-mediated immune response. Contact sensitivity to dinitrofluorobenzene (DNFB) was suppressed when SEA was injected before sensitization or before challenge with DNFB, indicating that SEA affected both the afferent and efferent phases of DNFB contact sensitivity. As the suppression of DNFB contact sensitivity could be transferred by anti-Thy-1.2 antibody-sensitive spleen cells of SEA injected donors into normal or DNFB-sensitized recipients, the suppression was thought to be an active one. However, SEA could augment the DNFB contact sensitivity when injected on the third day after sensitization with DNFB. These results indicate that the immunomodulating effects of SEA can be mediated by the T-cell function.

Animals↗

PubMed1985

Coexistence of growth hormone releasing factor-like and tyrosine hydroxylase-like immunoreactivities in neurons of the rat arcuate nucleus.

Neurons synthesizing growth hormone releasing factor were detected by immunocytochemistry with specific antiserum against synthetic rat hypothalamic growth hormone releasing factor. Growth hormone releasing factor immunoreactive neurons which also showed tyrosine hydroxylase immunoreactivity were located in the ventrolateral part of the arcuate nucleus. The functional significance of this finding for anterior pituitary hormone secretion is discussed.

Animals↗

PubMed1985

Renal inactive kallikrein as the possible origin of urinary inactive kallikrein in the rat.

An inactive kallikrein, which could be activated with trypsin was isolated from the rat kidney cortex using diethylaminoethyl (DEAE)-cellulose chromatography. The inactive kallikrein had no vasodilator action, whereas the injection of trypsin-activated form of this enzyme into the femoral artery of dogs resulted in a marked increase in the arterial blood flow. Apparent molecular weight of the inactive kallikrein was estimated to be 4.4 X 10(4) by gel filtration, and this enzyme was converted to the renal active kallikrein (M.W. 3.8 X 10(4] by trypsin. The inactive kallikrein is immunologically identical with the trypsin-activated form of inactive kallikrein and active kallikrein. There were no significant differences in the chromatographic behavior on a DEAE-cellulose column, Km value for prolyl-phenylalanylarginine-4-methylcoumaryl-7-amide hydrolysis and profile of inhibition by trypsin inhibitors between the active kallikrein and the trypsin-activated form of inactive kallikrein. The above properties of the renal inactive kallikrein were similar to those of inactive kallikrein found in the urine. These results suggest that the inactive kallikrein in the rat kidney would be proteolytically converted to its active enzyme and that a part of the inactive kallikrein would be excreted into urine in a form itself.

Animals↗

PubMed1985

Sino-orbital aspergillosis associated with total ophthalmoplegia.

Invasive aspergillosis of the paranasal sinuses involving the orbit is termed sino-orbital aspergillosis. Prognosis of sino-orbital aspergillosis, complicated by impaired visual acuity and neurological signs, is disastrous and usually fatal. We herein report two patients with sino-orbital aspergillosis associated with total ophthalmoplegia. One patient was successfully treated with surgical eradication including orbital exenteration. In contrast, the other died of cerebral infarction, probably due to fungal thrombosis of the middle cerebral artery, despite repeated local debridement followed by orbital exenteration and administration of antifungal agents. Experience with these cases strongly indicates the necessity of prompt surgical eradication, including orbital exenteration if necessary, in the treatment of sino-orbital aspergillosis.

Antifungal Agents↗

PubMed1985

Increase in plasminogen activator in the involuting uterus of the postpartum rat.

Plasminogen activator (PA) activity in the rat uterus was measured at fixed intervals post partum in order to determine whether this serine protease increases during the acute remodelling of tissue which occurs in the involuting uterus. Plasminogen activator activity was measured by an indirect method based on the hydrolysis of the chromogenic substrate S-2251 by PA-generated plasmin. At the time of parturition the control level of PA activity was 0.033 +/- 0.018 (S.D.) mumol/4 mg uterine wet weight per 30 min. This activity increased fourfold to a peak of 0.131 +/- 0.036 at 3 days post partum, and then it declined steadily towards the control level during the next 7 days. Concomitantly, uterine weight decreased to 25% of the control weight by 3 days post partum, and it continued to decrease until day 15. In the 30 days post partum during which PA activity was monitored there was no significant change in plasmin inhibitors in the uterine extracts. The results suggest a correlation between PA activity and the process of tissue remodelling which occurs during involution of the rat uterus. This increase in PA might serve to activate a latent collagenase since the measured peak in PA activity happens to coincide with a reported increase in collagenolytic activity in the involuting rat uterus.

Animals↗

PubMed1985