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Biomedical subjects

H Okamura

Publications and source records attributed to H Okamura.

At least 469 records · Page 26Linked to original sources
PubMed1992

Four cases of metastatic lymphoma into the temporal bone.

A histopathological study on 17 temporal bones obtained from 9 patients who died of malignant lymphoma revealed metastasis of malignant lymphoma in 7 temporal bones from 4 of them. There were no differences in stages at the initial diagnosis between the cases with metastasis and those without metastasis. However, the higher was the frequency of metastasis, the longer became the period from the first medical examination to death. In addition, malignant lymphoma was considered to metastasize into the temporal bone by the following two routes, 1) direct infiltration or invasion from the cerebrospinal fluid and 2) hematogenous metastasis or invasion.

Adult↗
PubMed1992

The relationship between ovarian progesterone and proteolytic enzyme activity during ovulation in the gonadotropin-treated immature rat.

To clarify the mechanisms by which progesterone acts as a mediator in the ovulatory process, ovulation rate and proteolytic enzyme activities were investigated in immature 22-day-old rats treated with PMSG/hCG, RU486 (10 mg/kg), synthetic antiprogesterone, and RU486 (10 mg/kg) + progesterone (10 mg/kg). The number of ova was significantly decreased when RU486 (10 mg/kg) was given from 2 h before to 4 h after the hCG injection. In addition, its inhibitory action on ovulation was reversed by exogenous progesterone (10 mg/kg) at 2 or 4 h after the hCG injection. Serum progesterone and estradiol concentrations in the rats treated with RU486 did not show any significant differences compared to controls. The proteolytic enzyme activities were measured by using the synthetic substrates alpha-N-benzoyl-DL-Arg-beta naphthylamide (BANA) and dinitrophenyl peptide (DNP). Activities were significantly increased after hCG injection in the control group during 8-9 h for BANA hydrolase and 7-10 h for DNP peptidase. The preovulatory increase of these activities was totally suppressed by RU486 with hCG. After administration of progesterone (10 mg/kg) following hCG and RU486 injection, the elevation of proteolytic, enzyme activities in the preovulatory phase was effectively reversed, and levels became similar to those in the control group. These results suggest that progesterone plays an indispensable role in the first 4 h of the ovulatory process by regulating proteolytic enzyme activities.

Animals↗
PubMed1992

Epostane and indomethacin actions on ovarian kallikrein and plasminogen activator activities during ovulation in the gonadotropin-primed immature rat.

Kallikrein and plasminogen activator (PA) are serine proteases that have been implicated in the ovulatory process. Epostane and indomethacin are anti-ovulatory agents that inhibit steroid and eicosanoid synthesis, respectively. This study examines the effects of these two anti-ovulatory agents on ovarian kallikrein and PA activities during ovulation. The proteases were assayed by their actions on chromogenic peptide substrates S-2266 and S-2251, respectively. The ovulatory process was induced in 25-day-old Wistar rats by giving them hCG (10 IU, s.c.) 2 days after the animals had been primed with eCG (10 IU, s.c.). Control animals ovulated approximately 60-70 ova/rat, with the first ova appearing in the oviducts at 10-12 h after hCG administration, and this was the same time ovarian kallikrein and PA activities reached a peak. When doses of epostane ranging from 0.1-5.0 mg/rat or doses of indomethacin ranging from 0.03 to 3.16 mg/rat were administered s.c. at 3 h after hCG, the two drugs inhibited ovulation and ovarian kallikrein and PA activities in a dose-dependent manner. However, the anti-ovulatory action of the two drugs was more closely correlated with suppression of kallikrein activity than with PA activity. Treatment of the animals with exogenous progesterone reversed the inhibitory action of epostane, but not of indomethacin. The results suggest that the increase in ovarian progesterone at the time of ovulation may influence ovarian kallikrein and PA activities.

Age Factors↗
PubMed1992

Immunohistochemical and ultrastructural examination of histiocytosis X cells in pulmonary eosinophilic granuloma.

We describe histological, immunohistochemical, and ultrastructural findings in pulmonary eosinophilic granuloma (PEG) from three patients. The specimens were taken by open-lung biopsy. The lesions of the lung were composed of histiocytic cells, macrophages and eosinophils. The histiocytic cells reacted positively with anti-S-100 protein antibody. The histiocytic cells had various types of Birbeck granules in the cytoplasm. The histiocytic cells were histiocytosis X (HX) cells considered to be derived from Langerhans cells. Sporadic mitosis of HX cells was observed. Some HX cells had migrated from the lesions into the alveolar spaces through the alveolar cell layers. In the lesions of PEG, HX cells have self-reproduction and migration capability.

Adolescent↗
PubMed1992

Monoclonal antibodies against the native urease of Helicobacter pylori: synergistic inhibition of urease activity by monoclonal antibody combinations.

Monoclonal antibodies (MAbs) against the native urease of Helicobacter pylori NCTC 11637 were found to clearly inhibit the urease activity. Interestingly, synergistic inhibition by two MAbs recognizing different subunits was also observed. Ten MAbs were produced and classified as two isotypes of the immunoglobulin G (IgG) subclass, IgG1, and IgG2a. Western blot (immunoblot) analysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that five MAbs recognized the large subunit and the other five recognized the small subunit of the urease. Among the MAbs, L2 and S2, which recognized the large and the small subunits, respectively, were also able to inhibit the urease activity of clinical isolates from H. pylori-infected patients. The combination of L2 and S2 led to augmented synergistic inhibition. L2, but not S2, could also inhibit the urease activity from Helicobacter mustelae; enzyme-linked immunosorbent assay and Western blot analysis showed that L2 cross-reacted with this urease. These results suggested that the epitope recognized by L2 had a structure common to both Helicobacter species and may be involved in the active site of the urease. In contrast to the MAbs, a polyclonal antibody in sera from mice immunized with H. pylori urease did not have the ability to inhibit H. pylori urease activity. However, the polyclonal antibody retained the ability to abolish the inhibitory action of these MAbs. Moreover, other MAbs which could not inhibit H. pylori urease activity also abolished the inhibitory action.

Antibodies, Bacterial↗
PubMed1992

Carcinoma of the cervix: dynamic MR imaging.

Dynamic magnetic resonance (MR) imaging was performed to evaluate eight normal uteri and 29 cervical carcinomas. After rapid injection of gadopentetate dimeglumine, dynamic images were obtained every 30 seconds with the spin-echo (SE) technique in the sagittal plane or the fast low-angle shot (FLASH) technique in the axial plane. In the normal uterus, initial slight enhancement of the junction between endometrium and myometrium was followed by enhancement of the uterine myometrium. Cervical carcinoma was readily distinguished from the cervical stroma and myometrium in the early dynamic phase (30-60 seconds). Tumor-cervix contrast in the early dynamic phase was significantly more marked with the dynamic SE technique than with T2-weighted or contrast material-enhanced T1-weighted imaging (P less than .01). For the evaluation of parametrial invasion, the dynamic FLASH study showed better contrast than did T2-weighted images. Among 18 patients who underwent surgery, accurate assessment of the degree of stromal invasion and tumor size was possible with dynamic MR images in 14 patients (78%), T2-weighted images in 11 (61%), and postcontrast T1-weighted images in seven (39%).

Carcinoma, Squamous Cell↗
PubMed1992

Transmandibular transpterygoid approach to the nasopharynx, parapharyngeal space, and skull base.

The nasopharynx, upper part of the parapharyngeal space, and skull base are relatively inaccessible to the surgeon without major postoperative complications. Operative fields reached by conventional approaches through the palate and maxillary sinus are too limited and narrow to remove extensive tumors. The authors applied a transmandibular transpterygoid approach for the removal of five residual nasopharyngeal carcinomas (NPCs) after full doses of irradiation, one pleomorphic adenoma of the nasopharynx, and one large parapharyngeal schwannoma extending into the jugular foramen. This approach offers a wide operative field so that large blood vessels and cranial nerves can be managed easily. All tumors were successfully resected. Two patients with benign neoplasma had uneventful recoveries after treatment. Of five patients with NPC, two are alive with no evidence of disease for 68 months and 50 months, respectively, while two died of metastases to the liver and bones. The other patient is alive with metastases in the lungs. No tumor recurred in the local primary site, however. Since the number of NPC cases is small, the usefulness of surgical removal of the postirradiation residual NPC is not clear. Our experience proved that the transmandibular transpterygoid approach is a practical method in the treatment of neoplastic lesions in the nasopharynx, parapharyngeal space, and skull base.

Adenoma↗
PubMed1992

Characterization of the structure and glycosylation properties of intracellular and cell surface rat hepatic prolactin receptors.

In this study we examined the structure of the PRL receptor of rat liver. We used immunoblotting with monoclonal antibodies to binding and nonbinding site epitopes of the PRL receptor to assess receptor subtypes in different hepatic subcellular fractions. Analysis of frozen-thawed cell fractions revealed 40- and 42-kilodalton (kDa) species. Digestion with neuraminidase indicated that both species were terminally sialylated. Freshly isolated membranes exhibited a single 42-kDa species in all subcellular fractions, whereas freeze-thawing generated the 40-kDa species. The carbohydrate linkages present in the PRL receptor were examined using enzymes to deglycosylate iodinated purified receptors. These studies indicated that oligosaccharides comprise about 7 kDa of receptor mass and that they are exclusively N-linked, consisting of tri- and/or tetra-antennary complex glycans. Monoclonal antibodies to the receptor recognized the deglycosylated receptor. Maximally deglycosylated receptors retained about 85% of their binding capacity. After in vivo tunicamycin treatment of rats, total PRL receptors (as determined by immunoblot analysis and binding activity) disappeared with a half-time of about 25 min. In this circumstance, no aglycosylated receptor species were recognized by monoclonal antibodies. Since deglycosylation of mature receptors did not markedly reduce binding capacity, we infer that mature receptors do not accumulate during the blockade of glycosylation by tunicamycin. Thus, glycosylation appears to be required for the acquisition of a mature receptor status, but is not necessary for the maintenance of that status.

Animals↗
PubMed1992

Effect of macrophages on proliferation of granulosa cells in the ovary in rats.

The effect of macrophages on proliferation of granulosa cells was examined in gonadotrophin-primed immature female rats. The mouse anti-rat macrophage monoclonal antibodies TRPM-2 and TRPM-3 were used and macrophages were observed in the granulosa layer and antrum of follicles and in corpora lutea and stroma around follicles. There was no difference in distribution between TRPM-2-positive cells and TRPM-3-positive cells. Macrophages with some cytoplasmic vacuoles of various sizes were also demonstrated in growing follicles. The average ratios of macrophages to granulosa cells in preantral, antral and mature follicles were 0.008, 0.007 and 0.002, respectively. Labelling with [3H]thymidine of granulosa cells cultured with peritoneal macrophages was significantly greater and the labelling index peaked to 25.0% when the ratio of macrophages to granulosa cells was 0.01, compared with the value of 14.2% when the granulosa cells were cultured alone. This ratio of macrophages to granulosa cells was similar to that in the preantral and antral follicles in vivo. These results suggest that macrophages participate in promoting proliferation of granulosa cells as local mediators in growing follicles.

Animals↗
PubMed1992

A polyclonal antibody to the rat oestrogen receptor expressed in Escherichia coli: characterization and application to immunohistochemistry.

A rat oestrogen receptor-beta-galactosidase fusion protein was expressed using a pEX2/rat oestrogen receptor cDNA construct. Scatchard analysis of [3H]oestradiol-17 beta binding to the cell lysate revealed that the fusion protein had functional binding sites specific for oestradiol with a dissociation constant of 1.49 nmol/l. The relative molecular weight (M(r)) of the fusion protein was determined as 180,000 by immunoblot analysis of the cell lysate employing a monoclonal antibody to the human oestrogen receptor. The protein was isolated by means of SDS-PAGE and subsequent electroblotting. By immunization with the purified materials on nitrocellulose membrane, a polyclonal antibody to the rat oestrogen receptor was raised in a rabbit. Binding of [3H]oestradiol to the oestrogen receptor from the rat uterus was inhibited by the antibody in a dose-dependent manner. The antibody was also able to recognize the oestrogen receptor occupied by [3H]oestradiol. Thus, the antibody could react with both forms of the receptor molecule, either occupied or unoccupied by the hormone. In immunoblot analysis of the cytosol fraction of the rat uterus, a single band of M(r) 67,000, the size of the oestrogen receptor, was detected by the antibody. Moreover, when the antibody was applied to immunohistochemical examination of paraffin-embedded pituitary and brain sections of the rat, immunostaining was observed in cells of the anterior pituitary and in neurones in specific regions of the brain. The immunoreactivity was restricted exclusively to cell nuclei in both tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Ovarian twin pregnancy.

Ovarian twin pregnancy is quite uncommon. We present a case of an ovarian twin pregnancy associated with pelvic endometriosis. The ultrasonographic findings in our case were similar to those of malignant ovarian tumor. Five cases of ovarian twin pregnancy, including this case, are reviewed.

Adult↗
PubMed1992

Localization of vasoactive intestinal peptide (VIP) messenger RNA (mRNA) in amacrine cells of rat retina.

We detected vasoactive intestinal peptide (VIP) messenger RNA (mRNA) in the rat retina using an in situ hybridization technique and a 35S-labelled cDNA probe. VIP mRNA was present in the cells of the inner nuclear layer (INL). The VIP mRNA-positive cells showed a distribution similar to that of the VIP-like immunoreactive amacrine cells. This observation suggests that VIP mRNA undergoes transcription in the VIP-immunoreactive amacrine cells.

Animals↗
PubMed1992

[Activated macrophages in the peritoneal fluid of women with endometriosis: examination of the intracytoplasmic localization of endogenous peroxidase and interleukin-1].

In order to study the effect of peritoneal macrophages (M phi) on conception in patients with endometriosis, the total numbers of peritoneal M phi and the proportion of the exudate type, defined on the basis of ultracytochemical localization of endogenous peroxidase (PO) activity, were investigated in 21 patients with endometriosis, five with uterine leiomyoma, three with tubal obstruction and three with carcinomatous peritonitis. An immunocytochemical observation of interleukin-1 (IL-1) was also performed in three patients with endometriosis, one with tubal obstruction, and one male patient with cholelithiasis. The total numbers of peritoneal M phi in patients with endometriosis were significantly higher than in uterine leiomyoma (2.11 x 10(7) v.s. 0.68 x 10(7), p less than 0.025). The total numbers of peritoneal M phi in tubal obstruction (0.96 x 10(7)) were not statistically different from those in uterine leiomyoma. The peritoneal M phi were remarkably increased in number in patients with carcinomatous peritonitis. On ultracytochemical observation of endogenous PO activity, the proportion of exudate M phi to whole M phi was significantly larger in endometriosis than that in uterine leiomyoma (13.3% v.s. 3.5%, p less than 0.025). This type of M phi increased even in stage I endometriosis (p less than 0.005). These data suggest that the abdominal cavity in women with endometriosis is in the stimulated conditions which may lead to infertility. A positive reaction to anti-IL-1 antibody on the cell membrane of all M phi examined in each patient suggests that an immunocytochemical study of IL-1 in M phi is not suitable for evaluating the degree of activation of M phi.

Animals↗
PubMed1992

[Disappearance of Philadelphia chromosomes after remission induction in lymphoid crisis of chronic myelogenous leukemia].

The authors report a rare case of chronic myelogenous leukemia (CML) in which the Ph1 clone disappeared after remission induction of lymphoid crisis. A 58-year-old man was admitted to our hospital because of fever in July 1988. The white cell count was elevated. Bone marrow aspirate showed hypercellularity with myeloid hyperplasia. In the chromosomal analysis, Ph1 chromosomes were detected in 100% of bone marrow cells analysed. Diagnosis of CML was made and treatment was initiated with recombinant interferon-alpha 2a. Hematological remission without cytogenetic improvement was achieved. In March 1990 he developed lymphoid crisis with proliferation of CD10-positive cells. The chromosomal analysis revealed additional abnormalities including, 45, X, -Y, t(9;22) (q34;q11), +1, -8. With vincristine 0.6 mgX4, pirarubicin 15 mgX4, dexamethasone 40 mgX4 therapy complete remission was obtained. In December 1990 the Ph1 positive clone completely disappeared judging from normal karyotypes in the chromosomal analysis and the disappearance of M-bcr gene rearrangement.

Blast Crisis↗
PubMed1992

[Blood concentrations of futraful, uracil and 5-fluorouracil (5-FU) after UFT administration in the various reconstructions after gastrectomy. Saitama UFT Research Group].

The study was undertaken in the total of 58 gastric cancer patients among which 17 of Billroth (BI), 14 of Billroth II (B II) anastomosis after subtotal gastrectomy, and 7 of jejunal interposition, 9 of double tract and 11 of Roux en Y anastomosis after total gastrectomy were included. Blood samples were taken before 200 mg of per oral UFT administration and after 1, 2, 3, 5 and 7hrs. consecutively. The blood Futraful (FT) level in the total gastrectomy groups reached peak concentration within 1hr and kept in relatively high level during the observation period of 7hrs. The time to maximum FT concentration delayed in almost of B I and a few of B II patients. The concentration curves of uracil (URA) and 5-FU were similar in shape, revealing steep increase and decrease except B I anastomosis which showed gentle course. The plotted maximum concentrations of URA and 5-FU in the every type of reconstruction showed a significant correlation in the regression line. In the analysis of AUC, URA/FT was under 10%, suggesting the longer retention of the unmetabolite type of FT and early disappearance of URA. The ratio of 5-FU/FT was indifferent in each reconstruction. 5-FU/URA was higher in subtotal rather than total gastrectomy groups. From the data obtained, blood concentration of 5-FU after UFT administration was considered to depend on the emptying status in the gastrectomies. And moreover, it depended on blood URA level, since FT from which 5-FU was derived, was kept still sufficiently remained during observation period.

Anastomosis, Roux-en-Y↗