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Biomedical subjects

H Okamura

Publications and source records attributed to H Okamura.

At least 595 records · Page 33Linked to original sources
PubMed1988

Ovarian mucinous cystadenocarcinoma producing alpha-fetoprotein.

Common epithelial ovarian tumors associated with alpha-fetoprotein (AFP) production are rare. A case of ovarian mucinous cystadenocarcinoma producing both AFP and carcinoembryonic antigen (CEA) is presented. A 53-year-old postmenopausal woman with right adnexal tumor underwent total hysterectomy and right salpingo-oophorectomy. Preoperative serum CEA and AFP levels were elevated to 660 and 1,120 ng/ml, respectively, and both decreased to their normal ranges after surgery. Histologically, the right ovarian tumor was diagnosed as a mucinous cystadenocarcinoma, composed of both intestinal-type cells and endocervical-type cells. Intestinal-type cells were identified ultrastructurally, with cells resembling neuroendocrine cells as well as gobletlike cells with many mucinous granules. Yolk sac or teratomatous components were not identified. By the immunoperoxidase technique, CEA was positive in well to moderately differentiated mucinous cells lining lumina, whereas AFP-positive cells were intermingled with CEA-positive cells in moderately differentiated epithelia.

Biomarkers, Tumor↗
PubMed1988

Purification of the multifunctional calmodulin-dependent protein kinases from lung and liver, and the comparison to the brain enzyme.

We purified the multifunctional calmodulin-dependent protein kinases (calmodulin-kinase) from rat lung and rabbit liver, and compared the properties of this enzyme with those of the rat brain enzyme. The lung and liver enzymes had molecular weights (Mr's) of 530,000 and 330,000 with main subunits of 52 and 51 kDa, respectively. Although the lung and liver enzymes cross-reacted with antibodies to the brain enzyme, the immunoreactivity of the lung enzyme was weaker. The substrate specificity of the three enzymes showed differences in the relative reaction rate of phosphorylation. The patterns of phosphopeptides of the lung and liver enzymes were similar to each other and only partly common to that of the 60-kDa subunit of the brain enzyme.

Animals↗
PubMed1988

Esophageal web in Plummer-Vinson syndrome.

In Plummer-Vinson syndrome, esophagography often reveals a web at the anterior wall of the cervical esophagus. The pathogenesis of the esophageal web and the cause of dysphagia in this syndrome were investigated radiographically, endoscopically, manometrically, and histologically. It was considered that the web seen in the esophagogram may have been formed due to the restriction of dilation of the esophageal wall, which results from repetitive inflammation and the subsequent healing process. Dysphagia in this syndrome may be explained by a decrease in swallowing power. Iron deficiency anemia may play the main role in the above histological changes and the resulting decrease in swallowing power.

Adult↗
PubMed1988

Effect of RU 486 on luteal function in the early pregnant rat.

A dose of 30 mg RU 486/kg, an antiprogesterone, was administered to pregnant rats on Day 2 (Group 1) or Day 4 (Group 2) of pregnancy. RU 486 significantly changed serum progesterone and oestradiol concentrations and luteal 3 beta-HSD and 20 alpha-HSD activities in Group 1, and implantation was significantly inhibited. The luteal 3 beta-HSD activity in Group 2 rats on Day 6 was significantly (P less than 0.01) lower than the control value (7.5 +/- 0.6 and 10.1 +/- 0.6 mU/mg protein respectively). This decline in the 3 beta-HSD activity was followed by a marked decrease in the serum progesterone concentration, resulting in a significant decrease of the progesterone/oestradiol ratio and implantation was completely inhibited. The 20 alpha-HSD activity, which could not be detected on Day 6 in the control rats, was twice as great in Group 2 than in Group 1 rats (17.5 +/- 1.2 and 7.4 +/- 3.1 mU/mg protein respectively). Ultrastructural examination of corpora lutea of Group 2 rats confirmed luteolysis. These results suggest that RU 486 has a luteolytic effect and its anti-implantation effect is concomitant with luteolysis of the corpora lutea of pregnancy.

20-Hydroxysteroid Dehydrogenases↗
PubMed1988

Inhibition of ovulation, steroidogenesis and collagenolytic activity in rabbits by sulpiride-induced hyperprolactinaemia.

Ovulation induced by hCG in rabbits was reduced significantly (P less than 0.005) by sulpiride-induced hyperprolactinaemia. The pre- and post-ovulatory increases in peripheral and ovarian venous progesterone (but not oestradiol or testosterone) were suppressed in the treated animals. The condition of hyperprolactinaemia also prevented the usual changes in 2,4-dinitrophenyl-Pro-Gln-Gly-Ile-Ala-Gly-Gln-D-Arg-OH peptidase (DNP-peptidase) and alpha-N-benzoyl-DL-Arg-beta-naphthylamide hydrolase (BANA-hydrolase) activities in follicular tissue that had been stimulated by an ovulatory dose of hCG. These results suggest that inhibition of progesterone production and collagenolytic enzyme activity by sulpiride-induced hyperprolactinaemia may be responsible for the ovulatory dysfunction that occurs when a mammal has a high level of circulating prolactin.

Animals↗
PubMed1988

Electrocardiographic changes related to hypersecretion of catecholamine in a patient with fulminant hepatitis.

A 48 year-old-man, with fulminant hepatitis complicated with myocarditis was treated. Despite intensive care, he died of fulminant hepatitis associated with hepatitis B virus infection. Electrocardiography (ECG) showed myocardial infarction-like changes when he went into a deep coma. Microscopically, scattered foci of myocardial cell damage and cell death associated with clusters of inflammatory cells were present in the heart at autopsy. However, there were no findings related to myocardial infarction and staining for hepatitis B surface antigen and core antigen were nil. The concentration of plasma catecholamine was elevated concomitantly with high level of ECG changes. We consider that abnormal ECGs may reflect a hypersecretion of catecholamine and suggest that our patient had a catecholamine cardiopathy.

Catecholamines↗
PubMed1988

Adult T-cell leukemia/lymphoma in pregnancy.

Adult T-cell leukemia/lymphoma, a lymphocytic leukemia caused by human T-cell lymphoma virus-I (HTLV-I), is prevalent in southwestern Japan. A Japanese woman with adult T-cell leukemia/lymphoma in the third trimester of pregnancy was delivered of an infant by cesarean section. She did not breast-feed the child, who has remained free from HTLV-I infection.

Adult↗
PubMed1988

Role of recombinant interleukin-1 compared to recombinant T-cell replacing factor/interleukin-5 in B-cell differentiation.

The B-cell differentiation-inducing activity of interleukin-1 (IL-1) was compared with that of T-cell replacing factor (TRF)/interleukin-5 (IL-5), which was originally described as a late-acting B-cell differentiation-inducing factor. Human recombinant IL-1 and murine recombinant TRF/IL-5 were used in this study. Purified B cells from non-primed or antigen-primed mice, LPS-stimulated B-cell blasts, and chronic B-cell leukaemia (BCL1) cells were used as the responding B-cell population. Addition of IL-1 to the culture of normal B-cells and sheep red blood cells (SRBC) induced a dose-dependent anti-SRBC IgM response, with maximal response at 100 U/ml, whereas the response induced by TRF/IL-5 was less than that induced by IL-1 and did not reach the maximum even at 100 U/ml. Addition of anti-IL-1 antibody, but not anti-TRF/IL-5 antibody or anti-IL-2 receptor antibody, inhibited IL-1-induced anti-SRBC responses. Depletion of cells adherent to Sephadex beads from splenic B cells showed no significant effect on the magnitude of the total responses. IL-1 could induce little, if any, differentiation in antigen-primed B cells, LPS-stimulated B-cell blasts, or BCL1 cells into antibody-secreting cells, whereas differentiation could be induced by low doses of TRF/IL-5 (1-2 U/ml). Of great interest is that suboptimal doses of IL-1 (10 U/ml) could synergize with TRF in the primary anti-SRBC PFC responses. Kinetic studies revealed that IL-1 acts on B cells for the first 2 days and TRF/IL-5 for the last 3 days in 5-day cultures of B cells. These results suggest that IL-1 acts primarily on resting B cells as a differentiation-inducing factor in the presence of antigen, and also acts as a 'priming' factor for TRF/IL-5.

Adjuvants, Immunologic↗
PubMed1987

Immunocytochemical distribution of met-enkephalin-Arg6-Gly7-Leu8 in the rat lower brainstem.

The distribution of methionine-enkephalin-Arg6-Gly7-Leu8, a unique peptide derived from proenkephalin A in the rat brainstem, was studied immunocytochemically by using a highly specific antiserum to this octapeptide sequence. Immunoreactive perikarya with various shapes and sizes were detected in many regions of the rat brainstem. Dense accumulation of immunoreactive perikarya and fibers was seen in the nuclei associated with special sensory and visceral functions, such as the interpeduncular nucleus, the parabrachial nucleus, the nucleus of the solitary tract, and the nucleus of the spinal tract of the trigeminal nerve. Clusters of methionine-enkephalin-Arg6-Gly7-Leu8-like immunoreactive perikarya and fibers were observed in certain areas considered to play a role in nociception and analgesia, such as the central gray of the midbrain central gray and the raphe magnus nucleus. Some methionine-enkephalin-Arg6-Gly7-Leu8-like immunoreactive perikarya were distributed in the lateral reticular nucleus, the nucleus of the solitary tract, and the raphe magnus nucleus, where monoaminergic neurons were also detected. In addition to the previously reported enkephalinergic cells, we found many methionine-enkephalin-Arg6-Gly7-Leu8 containing neurons; the rostral and caudal linear nucleus of raphe, the median raphe nucleus, entire length of the raphe magnus nucleus, the medial longitudinal fasciculus, the cuneate nucleus, the external cuneate nucleus, the gracile nucleus, and the area postrema. The wide distribution of this octapeptide-like immunoreactivity reflected neurons expressing the preproenkephalin A gene distributed more widely than previously reported and that innervated many regions.

Animals↗
PubMed1987

Distribution of neurotensin-like immunoreactivity in the diencephalon of the Japanese monkey (Macaca fuscata).

The distribution of neurotensin-like immunoreactive (NT-LI) neurons was examined in the thalamus and hypothalamus of the Japanese monkey (Macaca fuscata) by using the peroxidase-antiperoxidase immunocytochemistry technique. In the thalamus, NT-LI neuronal perikarya were distributed mainly in the midline nuclear group and the dorsomedial nucleus, and partially in the intralaminar nucleus: Immunoreactive fibers were mainly distributed in the midline nucleus, particularly in the nucleus rhomboidalis. Numerous immunoreactive fibers were also detected in the regions that contain the pathways to extrathalamic areas such as the stratum zonale and inferior thalamic peduncle. In the hypothalamus, many immunoreactive neuronal perikarya were distributed in the lateral hypothalamic area and in the arcuate nucleus. Immunoreactive fibers were disseminated throughout the hypothalamus, but they were dense in the preoptic area and sparse in the ventromedial nucleus. An accumulation of dense immunoreactive endings was also observed in the external layer of the median eminence. NT-LI fibers in the external layer of the median eminence were considered to represent nerve endings near portal vessels. Functional roles of neurotensin in the thalamus and hypothalamus are discussed from the anatomical point of view.

Animals↗