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Biomedical subjects

H Okamura

Publications and source records attributed to H Okamura.

At least 631 records · Page 35Linked to original sources
PubMed1987

Malignant granular cell tumor of the esophagus. A case report with light and electron microscopic, histochemical, and immunohistochemical study.

Malignant granular cell tumor of the esophagus found in a 70-year-old female was reported. Microscopically, the tumor showed a variety of the histology from compact proliferation of polygonal granular cells in pseudo-epitheliomatous pattern to plexiform proliferation of elongated granular and fibroblastic cells in neurofibromatous pattern, and the tumor cells frequently contained eosinophilic globules in the cytoplasm. Histochemically, argyrophilic neurofibrils in the stroma and argyrophilic cytoplasmic processes or grains were seen. Immunohistochemically, the tumor cells showed positive reaction with S-100 protein (S-100), but all reactions with myoglobin (MG), desmin (DM), fibronectin (FN), creatinine phosphokinase-mm (CPK), factor 8th-related antigen (F8RA), alpha-1-antitrypsin (A1AT), alpha-1-antichymotrypsin (A1ACT), keratin (KN), and carcinoembryonic antigen (CEA) were negative. Electron microscopy revealed that the tumor cells had typical lysosomal granules filled with proteinaceous electron dense materials and fine membrane-bound particles sized 15 to 45 nm resembling virus or neurosecretory granule.

Aged↗
PubMed1987

[Cefmenoxime transport into the bile, especially in the intra- and postoperative periods].

Using 13 patients undergoing operation of the bile duct, cefmenoxime (CMX) transport into the bile and the gallbladder tissue was investigated. One gram of CMX was administered through drip infusion over 30 minutes every 12 hours. CMX concentration in bile was measured for samples surgically collected about 103 minutes (75-141 minutes) after the start of CMX administration. CMX concentrations in bile samples collected from gallbladder were found to be as high as 326.6 +/- 432.3 micrograms/ml in patients with neither jaundice nor cystic duct obstruction, indicating sufficient CMX transport. When cystic duct obstructions were present, CMX concentrations were very low, or moderately low if jaundice was also present. Changes in CMX concentration were then measured over 6 hours after administration in patients with an external biliary fistula every other day for a period of 7 days, from the first postoperation day. As for horal changes, CMX concentration reached its peak in 2 hours after the start of administration in most cases. Maximum CMX concentrations in patients without jaundice were high, ranging from 313.3 to 1,232.3 micrograms/ml (mean, 641.2 micrograms/ml), and CMX was found at 4.0-76.6 micrograms/ml (mean, 37.4 micrograms/ml), even after 6 hours. As for diurnal changes, CMX was determined to be sufficiently transported into the bile from the first postoperation day. Although CMX concentrations tended to be lower on the fifth postoperation day than on other days, there was no statistical significance in differences in daily concentrations examined. CMX concentrations in gallbladder tissues were determined to be 22.7 4/- 32.1 micrograms/g, and they decreased over time exponentially.

Adult↗
PubMed1986

Vasoactive intestinal peptide- and peptide histidine isoleucine amide-like immunoreactivity colocalize with vasopressin-like immunoreactivity in the canine hypothalamo-neurohypophysial neuronal system.

The distribution of vasoactive intestinal peptide (VIP) and peptide histidine isoleucine amide (PHI) was investigated in the canine hypothalamus by immunocytochemistry. VIP- and PHI-like immunoreactive neurons were detected in the magnocellular supraoptic and paraventricular nucleus. These magnocellular VIP- and PHI-producing neurons coexist with vasopressin-like immunoreactivity and send axons to the median eminence and neurohypophysis. These findings may serve as an anatomical basis for studying the function of VIP and PHI on pituitary hormone secretion.

Animals↗
PubMed1986

Undermethylation of interferon-gamma gene in human T cell lines and normal T lymphocytes.

The relative levels of DNA methylation at CCGG sequences within and around the interferon-gamma (IFN-gamma) gene in normal human tissues and cell lines were examined by Southern blot analysis using isoschizomeric restriction enzymes, HpaII and MspI. On the test of normal tissues, the IFN-gamma gene was undermethylated only in a small population of T lymphocyte, whereas the gene was fully methylated in T cell-depleted lymphocytes and uterus cells. In TCL-Fuj cell line which is a T cell line producing a high level of IFN-gamma spontaneously, the IFN-gamma gene was undermethylated. Moreover, the extent of DNA methylation was inversely correlated to the level of expression of the IFN-gamma gene in several T cell lines including sublines derived from TCL-Fuj cells. However, partial or complete unmethylation at the CCGG sites of IFN-gamma gene was observed in a promyelocytic leukemia cell line and two epithelial cell lines that fail to produce IFN-gamma irrespective of induction. These results suggest that undermethylation of IFN-gamma gene is necessary but not sufficient for its efficient expression.

Cell Line↗
PubMed1986

Light and electron microscopic immunocytochemistry of GRF-like immunoreactive neurons and terminals in the rat hypothalamic arcuate nucleus and median eminence.

Growth hormone-releasing factor (GRF) synthesizing neuronal perikarya and terminals were investigated by light and electron microscopic immunocytochemistry using rat hypothalamus. Immunoreactive neuronal perikarya were located mainly in the ventrolateral part of the arcuate nucleus. They contained well developed cell organella such as mitochondria and rough surfaced endoplasmic reticulum with some expansion. They also contained immunoreactive dense granules (80-120 nm in diameter). On the surface of the immunoreactive neuronal perikarya were frequently found non-immunoreactive axo-somatic synapses. Therefore, the GRF-like immunoreactive neurons were assumed to receive neuronal inputs from other neurons on their neuronal soma. In the external layer of the median eminence large numbers of immunoreactive terminals were distributed particularly around the capillaries of the portal vessel. Electron microscopic immunocytochemistry revealed large numbers of immunoreactive terminals containing immunoreactive dense granules, synaptic vesicles and mitochondria in the vicinity of the basement membrane of the pericapillary space of the portal vessel. Therefore, we concluded that GRF-like immunoreactive substances are released into the portal capillaries from the nerve terminals, which originate from the neuronal perikarya in the ventrolateral part of the arcuate nucleus, and act on growth hormone release in the anterior pituitary. We also suggest that GRF-like immunoreactive neurons have abundant terminal arborization in the external layer of the median eminence.

Animals↗
PubMed1986

Sexual differences in the distribution of substance P immunoreactive fibers in the ventral horn of the rat lumbar spinal cord.

The distribution of substance P (SP) in the rat spinal cord was investigated by peroxidase-anti-peroxidase immunocytochemistry combined with retrograde horseradish peroxidase (HRP) labeling via the cremaster muscle. In the male rats, a dense network of SP immunoreactive (SP-IR) fibers and terminals was detected in the ventral column of the L1 and L2 segments (Vent L1-2) with a different density and extent from the other segmental levels. These fibers and terminals were accumulated within and around the nucleus centromedialis lumbaris (CM) of the L1 and L2 segments. However, in the female rats, SP-IR fibers and terminals were sparse in the Vent L1-2 without particular segmental differences. HRP-positive motoneurons were located in the CM and surrounded by SP-IR fibers and terminals. These results indicate that the Vent L1-2 of the rat spinal cord shows sexual dimorphism with respect to the regional distribution of SP-IR fibers and terminals, and that motoneurons that innervate the cremaster muscle are innervated by dense SP-IR fibers and terminals.

Animals↗
PubMed1986

Purification of inactive kallikrein from rat urine.

An inactive kallikrein was purified from rat urine, and some of the properties of this enzyme were examined, in comparison with those of rat urinary kallikrein (RUK). The purified inactive kallikrein reacted with the antiserum against RUK and migrated slightly more slowly than RUK, on the immunoelectrophoresis. The molecular weights of the inactive kallikrein and RUK were estimated to be 44,000 and 38,000 by gel filtration, respectively. These results indicate that the rat urinary inactive kallikrein is immunologically identical with RUK, but this inactive enzyme has biochemical properties different from those of RUK, with respect to molecular weight and electrophoretical mobility.

Amino Acids↗
PubMed1986

Mucinous cystadenocarcinoma of the retroperitoneum: a light and electron microscopic study.

A large, ovarian-type, retroperitoneal cystic tumor existing in the presence of normal ovaries was studied morphologically by light and electron microscopy. The cyst was monolocular, having several papillary nodules which measured 0.2-2.0 cm in diameter, and protruded into the lumen. Histologically, most of the tumor wall was covered by mesothelium-like cells which showed signs of differentiation into either a benign endocervical type mucinous epithelium or a mucinous epithelium of borderline malignancy, particularly around the nodules. The papillary nodules themselves had the histological features of a well-differentiated mucinous adenocarcinoma. These light and electron microscopic features resembled those of ovarian mucinous tumors. Histogenetically, the tumor appeared to be derived from a mesothelial inclusion cyst; some of the mesothelium being transformed by metaplastic change into the endocervical type mucinous epithelium and undergoing further transformation into either the mucinous epithelium of borderline malignancy or the well-differentiated mucinous adenocarcinoma by some unknown factors.

Aged↗
PubMed1986

Thyrotropin-releasing hormone and gonadotropin-releasing hormone test to predict effectiveness of bromocriptine therapy in infertile women.

Sixty-four infertile women presenting with luteal phase defect, anovulatory cycle, and secondary amenorrhea were compared with 15 normal cycling women with bolus injections of thyrotropin-releasing hormone (TRH) and gonadotropin-releasing hormone (GnRH) before bromocriptine (BCPT) therapy. All of the women had normal baseline prolactin (PRL), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) concentrations. Responses of PRL, LH, and FSH levels were measured. PRL responses in BCPT responders were markedly greater than in controls and nonresponders. A better responder rate to BCPT therapy was observed in patients with apparent (88.9%) or borderline (69.2%) exaggerated responses of PRL to TRH than in normal patients (41.7%). Further, in patients with normal PRL responses, the inappropriately enhanced LH responses were seen in BCPT responders but not in nonresponders. These findings suggest that TRH and GnRH tests are worthwhile in predicting the outcome of BCPT therapy in infertile patients.

Adult↗
PubMed1986

Effects of timed melatonin infusion on prolactin secretion in pineal denervated goat.

The effects of timed melatonin infusion on prolactin secretion were examined in the pineal denervated goat. Ovariectomized Shiba goats (n = 5) were subjected to bilateral superior cervical ganglionectomy (SCGX); this procedure resulted in complete abolition of endogenous melatonin release during the dark phase. SCGX goats failed to coordinate their prolactin secretion with the prevailing photoperiod. Melatonin was infused (20 micrograms/h, s.c.) daily into these goats either for 8 h (the long-day-type infusion) or for 16 h (the short-day-type infusion) to mimic the nocturnal profile of plasma melatonin under long days or short days, respectively. The long-day-type melatonin infusion for 9 days, in comparison with control saline infusion, accelerated prolactin secretion, inducing a nocturnal rise in plasma prolactin; this was comparable to that seen in the pineal intact goats under long photoperiods. On the other hand, the short-day-type melatonin infusion suppressed prolactin secretion throughout the day as the short-day treatment did in intact goats. The prevailing photoperiod appeared to have no distinct effect on these prolactin responses to exogenous melatonin, which were indistinguishable under 16L8D and 8L16D conditions. The results indicate that the information about external light-dark cycles is converted by the pineal gland into the endocrine signal as a daily pattern of melatonin secretion, which eventually regulates prolactin secretion from the pituitary gland of the goat.

Animals↗
PubMed1986

Low endotoxic activities of synthetic Salmonella-type lipid A with an additional acyloxyacyl group on the 2-amino group of beta (1-6) glucosamine disaccharide 1,4'-bisphosphate.

A synthetic lipid A (Salmonella type, compound 516), beta (1-6)-linked D-glucosamine disaccharide 1,4'-bisphosphate, with three acyloxyacyl groups and one hydroxyacyl group, i.e., (R)-3-hexadecanoyloxytetradecanoyl, (R)-3-hydroxytetradecanoyl, (R)-3-dodecanoyloxytetradecanoyl, and (R)-3-tetradecanoyloxytetradecanoyl groups at the 2-amino, 3-hydroxyl, 2'-amino, and 3'-hydroxyl groups, respectively, was less biologically active than the synthetic Escherichia coli-type lipid A (compound 506), which has only two acyloxyacyl groups at the 2' and 3' positions and is substituted with a (R)-3-hydroxytetradecanoyl group at the 2-amino group. Compound 516 exhibited considerably weaker pyrogenic and leukopenic activity than compound 506, and it scarcely prepared rabbit skin for the Shwartzman reaction and lacked lethal toxicity on chicken embryos, although its lethal toxicity in galactosamine-loaded mice was as strong as that of compound 506. Compound 516 was also less active than compound 506 or natural E. coli lipid A (from Restrain F515) in other biological test systems, such as the Limulus test, stimulation of macrophages and lymphocytes, and interferon-inducing activity but not for interleukin-1 induction or complement activation. This observation suggests that there is an optimal number of acyloxyacyl groups on the glucosamine backbone for producing the biological activities of lipid A, especially the endotoxic activities. The 4'-monophosphate analog (compound 514) of compound 516 in general had significantly weaker activity than compound 516 in the above assays, most probably because of its greater hydrophobicity and consequently lower solubility in assay systems. Bacterial R595 lipid A derived from S. minnesota Re-mutant, which is a mixture of compounds 516 and 506, their 4'-monophosphate analogs and other compounds, exerted intermediate degrees of activity between compounds 506 and 516 in the various test systems employed.

Adjuvants, Immunologic↗