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Biomedical subjects

H Shimoda

Publications and source records attributed to H Shimoda.

At least 37 records · Page 2Linked to original sources
PubMed1999

Effects of phyllodulcin, hydrangenol, and their 8-O-glucosides, and thunberginols A and F from Hydrangea macrophylla SERINGE var. thunbergii MAKINO on passive cutaneous anaphylaxis reaction in rats.

We examined the antiallergic effects of phyllodulcin, hydrangenol, and their 8-O-glucosides, and thunberginols A and F isolated from the processed leaves (Hydrangeae Dulcis Folium) and dried leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO using the passive cutaneous anaphylaxis (PCA) reaction. With the exception of phyllodulcin, these constituents were found to significantly inhibit the PCA reaction. Although thunberginol A showed the most potent inhibitory effect, hydrangenol was considered to be the principal antiallergic component in the processed leaves, after taking into account their contents.

Animals↗
PubMed1999

The role of thunberginol A, an isocoumarin constituent of Hydrangeae Dulcis Folium, on the signal transmission pathway for rat mast cell degranulation.

The role of the signal transmission pathway of thunberginol A (TA) in mast cell degranulation was examined using rat peritoneal mast cells. First of all, we investigated the cellular distribution of TA using fluorescent microscopy. This indicated that TA is immediately incorporated into cells and distributes in cytosol around the nucleus. We then investigated the effect of TA on mast cell protein tyrosine phosphorylation, which is part of the signal transduction cascade for degranulation. TA non-specifically inhibited the tyrosine phosphorylation induced by compound 48/80 (Co. 48/80), at 10 to 100 microM, and orthovanadate/hydrogen peroxide at more than 50 microM in a dose-dependent manner. As far as the intracellular Ca2+ change in fluo-3-loaded cells was concerned, TA (10 microM) suppressed the rise in Ca2+ induced by antigens, ionomycin and thapsigargin, while TA did not suppress the rise induced by Co. 48/80. This evidence suggests that TA mainly inhibits extracellular Ca2+ influx, but TA does not act on the intracellular Ca2+ mobilization from the endoplasmic reticulum. We also investigated the influence of TA on the cytoskeleton and membrane changes using mast cells and erythrocytes. TA (10 microM) inhibited the cytoskeletal assembly formation in dicyanovinyl julolidin-loaded mast cells induced by Co. 48/80. Moreover, TA suppressed the hypotonic hemolysis of erythrocytes, from 3 to 1000 microM, in a dose-dependent manner. These results suggest that inhibition of protein tyrosine phosphorylation, extracellular Ca2+ influx and cytoskeletal assembly formation, and membrane stabilization are involved in the inhibitory effect of TA in mast cell degranulation.

Animals↗
PubMed1999

Chemical constituents from the leaves of Hydrangea macrophylla var. thunbergii (III): Absolute stereostructures of hydramacrosides A and B, secoiridoid glucoside complexes with inhibitory activity on histamine release.

Following the characterization of dihydroisocoumarin constituents, two secoiridoid glucoside complexes, called hydramacrosides A and B, were isolated from the leaves of Hydrangea macrophylla Seringe var. thunbergii Makino. The absolute stereostructures of hydramacrosides A and B were elucidated on the basis of chemical and physicochemical evidence, which included the application of the 13C-NMR glycosylation shift rule of 1,1'-disaccharides and the modified Mosher's method. Hydramacrosides A and B exhibited an inhibitory effect on histamine release from rat mast cells induced by an antigen-antibody reaction.

Acetylation↗
PubMed1998

Immunomodulatory activity of thunberginol A and related compounds isolated from Hydrangeae Dulcis Folium on splenocyte proliferation activated by mitogens.

We investigated the immunomodulatory effects of antiallergic constituents from Hydrangeae Dulcis Folium, the processed leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO, on splenocyte proliferation in mice. Thunberginol A and hydrangenol significantly suppressed T lymphocyte proliferation induced by concanavalin A. Thunberginol A also suppressed B lymphocyte proliferation induced by lipopolysaccharide, but other constituents induced significant increases. These inhibitory effects of thunberginol A on splenocyte proliferation seemed to contribute to the suppressive effect on type IV allergy.

Adjuvants, Immunologic↗
PubMed1998

Vascular leiomyosarcoma arising from the inferior vena cava diagnosed by intraluminal biopsy.

A 61-year-old woman developed pain in the right thigh, paraplagia of the lower extremities and lumbago in November 1996. A lumbar spine roentgenogram showed lytic change in L2, and magnetic resonance imaging showed a patchy destructive lesion and compression of the dural sac from the right by a tumour. Computed tomography (CT) myelography showed a motheaten destructive lesion in L2 and projection of the tumour into the spinal canal. Abdominal ultrasound, CT and cavography showed dilatation of the inferior vena cava (IVC) and an intraluminal tumour about 2x2.8x4 cm in size in the IVC. The tumour arose from the IVC just beneath the renal vein and extended to just short of the right atrium. Both vertebral and intraluminal biopsy materials showed the same morphology, in which atypical spindle cells admixed with multinucleated giant cells proliferated in a fascicular growth pattern. Neoplastic cells were strongly positive for alpha-smooth muscle actin. We diagnosed vascular leiomyosarcoma arising from the IVC with metastasis to the lumbar vertebrae. Cases of vascular leiomyosarcoma diagnosed by intraluminal biopsy are rare.

Biopsy↗
PubMed1998

Development of bioactive functions in Hydrangeae Dulcis Folium. VII. Immunomodulatory activities of thunberginol A and related compounds on lymphocyte proliferation.

Immunomodulatory activities of constituents isolated from Hydrangeae Dulcis Folium and their related compounds on lymphocyte proliferation were investigated using splenocytes and lymph node cells. Thunberginol A (TA) significantly suppressed B lymphocyte proliferation stimulated by lipopolysaccharide (LPS) at 10(-5) M. However TA at a lower concentration (10(-6) M) and the other compounds, except hydrangenol and 3'-hydroxyhydrangeaic acid, tended to potentiate B lymphocytes proliferation (10(-5) M). On the other hand, thunberginol A significantly suppressed T lymphocyte proliferation stimulated by concanavalin A (Con A), but did not suppress phytohemagglutinin (PHA). Hydrocortisone and cyclosporin A strongly suppressed T lymphocyte proliferation induced by both Con A and PHA. These results suggest that thunberginol A acts on both B and T lymphocytes and may have a suppressive mechanism different from the known immunosuppressants. The cytotoxicity of TA for splenocytes seemed weaker than known immunosuppressants resulting from viability tests using MTT assay and the measurement of lactate dehydrogenase (LDH) released in the medium. Moreover, TA suppressed antigen-specific T lymphocyte proliferation in mice lymph node cells immunized with keyhole limpet hemocyanin (KLH). Thus, these findings show that TA has a suppressive effect on lymphocyte activation, and this inhibitory effect of TA seems to contribute to its suppressive effect on type IV allergies.

Animals↗
PubMed1998

Organization of nitric oxide-producing nerves in the rat pyloric sphincter.

The architecture of nitric oxide (NO)-producing nerves in the rat pylorus was studied in relation to the muscular structure. The musculature of the rat pylorus was observed to be composed of two discrete muscle loops (proximal and distal sphincters). Connective tissue septa containing neural elements divided the thick musculature of the distal sphincter into many bundles. The myenteric nerve plexus of the stomach with a subpopulation of NO-producing nerves was continuous with that of the duodenum. Nitrinergic nerve fibers which originated from the antral myenteric plexus ran through the connective tissue septa in the pyloric musculature and were densely distributed on the submucosal surface of the distal sphincter. The innermost portion of the distal sphincter consisted of smooth muscle cells showing many cytoplasmic processes and abundant nitrinergic nerve terminals. This particular architecture of the nitrinergic nerves in the sphincter would seem to account for the coordinate motor function of the rat pyloric sphincter.

Animals↗
PubMed1998

Structural organization of lymphatics in the monkey esophagus as revealed by enzyme-histochemistry.

The fine structure and distribution of lymphatic vessels in the monkey esophageal wall were studied by light and electron microscopy using an enzyme-histochemical method. Identification of lymphatics was made by 5'-nucleotidase staining, whereas blood vessels were visualized by alkaline phosphatase staining. This technique revealed intramural lymphatic networks in the mucosa, submucosa, and myenteric layer of the esophagus. The organization of lymphatics in the esophagus basically conformed to that of the small intestine, although they showed certain distribution patterns peculiar to the esophagus. The lamina propria mucosae exhibited a double-layered lymphatic network, and lymphatic capillaries extended into its papillae. Despite their forming blind ends and being closed by endothelial cells, the lymphatics in the mucosal papillae were found to contain lymphocytes in their lumen. This suggests that free cells might penetrate the endothelium to enter these initial portions of the lymphatics.

5'-Nucleotidase↗
PubMed1998

Lymphatic network and nerve plexus in the myenteric layer of the monkey jejunum: a topographic study using an enzyme-histochemical method.

The topographic relationship between the lymphatic network and the nerve plexus in the myenteric layer of the monkey jejunum was studied by an enzyme-histochemical method. Identification of the lymphatics was achieved by a 5'-nucleotidase staining method, and the enteric neural components were visualized by acetylcholinesterase staining. A well-developed lymphatic network and a dense nerve plexus were demonstrated throughout the myenteric layer. Numerous segments of the initial lymphatics, with their blind endings at the apical parts, tended to gather toward the ganglion and run along the primary nerve strands. Elements of the tissue interstitium separated the lymphatics from the enteric nerves. Nerve terminals were often located closely beneath the endothelium of the initial lymphatics and were exposed to the subendothelial tissue on the side facing the abluminal surface of the lymphatic endothelium. These findings suggest that the lymph flow in the initial lymphatics might be regulated by the enteric nervous system, and that the transport of tissue fluid by the lymphatics might serve as a suitable microenvironment for the enteric nerves.

Animals↗
PubMed1998

Transient isolated thyrotropin deficiency associated with cavernous sinus syndrome.

The cause and course of isolated thyrotropin (TSH) deficiency are not well understood. We report a 65-year-old man with a transient, probable isolated TSH deficiency associated with cavernous sinus syndrome secondary to tympanitis. On his admission, serum TSH and triiodothyronine levels were very low. No TSH response to thyrotropin releasing hormone (TRH) was observed. However, 6 years later, TSH response to TRH was restored. The present case showed that inflammation in the cavernous sinus could be one of the causes of TSH deficiency. Further, it demonstrated that TSH deficiency is not always permanent and the reevaluation of pituitary function is necessary.

Aged↗
PubMed1997

Expression of PCNA and p53 in esophageal dysplasia and esophageal carcinoma.

We examined the immunohistochemical expression of proliferating-cell nuclear antigen (PCNA) and p53 proteins in dysplasia and intramucosal carcinoma of the esophagus. Immunohistochemistry was performed with monoclonal antibodies directed against PCNA and p53. We used surgically resected specimens from 29 patients who had a total of 55 lesions of severe dysplasia (n = 16), intraepithelial carcinoma (n = 21), and mucosal carcinoma (n = 18). The mean PCNA index with immunoreactivity for p53 was 48.9 +/- 6.5 in areas of severe dysplasia (n = 7), 58.2 +/- 7.3 in areas of intraepithelial carcinoma (n = 10), and 71.4 +/- 9.3 in the invasive areas of mucosal carcinoma (n = 10). The mean PCNA index without immunoreactivity for p53 was 41.2 +/- 5.5 in areas of severe dysplasia (n = 9), 48.0 +/- 7.4 in areas of intraepithelial carcinoma (n = 11), and 63.7 +/- 9.1 in invasive areas of mucosal carcinoma (n = 8). The PCNA indices of the areas of severe dysplasia with immunoreactivity for p53 were significantly lower than those of intraepithelial carcinoma and mucosal carcinoma with immunoreactivity for p53. Similarly, the PCNA indices of severe dysplasia without immunoreactivity for p53 were significantly lower than those of intraepithelial carcinoma and mucosal carcinoma without immunoreactivity for p53. These results thus suggest that severe dysplasia has a lower proliferative potential than carcinoma and may therefore represent a precancerous lesion.

Adult↗
PubMed1997

Bioactive constituents of Chinese natural medicines. IV. Rhodiolae radix. (2).: On the histamine release inhibitors from the underground part of Rhodiola sacra (Prain ex Hamet) S. H. Fu (Crassulaceae): chemical structures of rhodiocyanoside D and sacranosides A and B.

The methanolic extract of the underground part of Rhodiola sacra (PRAIN ex HAMET) S. H. Fu was found to show inhibitory activity on the histamine release from rat peritoneal exudate cells induced by an antigen-antibody reaction. From the methanolic extract with the inhibitory activity on histamine release, a new cyanoglycoside called rhodiocyanoside D and two new monoterpene glycosides called sacranosides A and B were isolated, together with eight known compounds, rhodiocyanoside A, heterodendrin, lotaustralin, rhodioloside, 2-phenylethyl alpha-L-arabinopyranosyl(1-->6)-beta-D-glucopyranoside, 2-methyl-3-buten-2-yl beta-D-glucopyranoside, kenposide A, and rhodiooctanoside. The structures of new compounds were determined on the basis of chemical and physicochemical evidence, which included the synthesis of sacranoside A from (-)-myrtenol. All major chemical constituents from R. sacra inhibited the histamine release and, among them, lotaustralin and rhodiooctanoside were found to show potent inhibitory activity.

Animals↗
PubMed1997

Medicinal foodstuffs. VI. 1) Histamine release inhibitors from kidney bean, the seeds of Phaseolus vulgaris L.: chemical structures of sandosaponins A and B.

Two new olean-12-ene-type triterpene oligoglycosides, named sandosaponins A and B, were isolated from kidney bean, the seed of Phaseolus vulgaris L., together with three known saponins, soyasaponins I and V and dehydrosoyasaponin 1. The structures of sandosaponins A and B were determined on the basis of chemical and physicochemical evidence, which included the chemical derivation of sandosapogenol from a known sapogenol, soyasapogenol B. Five saponins obtained from kidney bean were found to inhibit histamine release from rat exudate cells induced by an antigen-antibody reaction and, among them, sandosaponins A and B showed the most potent inhibitory activity.

Animals↗
PubMed1997

Afferent migration of the Kurloff cells via lymphatics into the thymus of estradiol-treated guinea pigs.

The spatial distribution and migration of Kurloff cells containing PAS-positive large inclusion bodies in the thymus of estradiol-treated guinea pigs were histochemically studied by a combination of light and electron microscopy. Male guinea pigs were examined at various intervals from 7 days to 3 months after a single subcutaneous injection of estradiol. Differentiation of lymphatics from blood capillaries was performed by a 5'-nucleotidase (5'-Nase) staining method and the occurrence of Kurloff cells within 5'-Nase-positive lymphatics was confirmed by ultrastructural histochemistry. Several Kurloff cells first appeared at 7 days within lymphatics in the thymic capsule or interlobular connective tissues. At 12-15 days after estradiol administration, a lymphatic accumulation, a so-called "lymphatic center", was seen in the thymic septa even though few Kurloff cells were present within the thymic parenchyma. The "lymphatic center" contained many Kurloff cells located in its periphery and in the surrounding marginal sinus which communicated with the thymic interlobular lymphatics. At 21 days after estradiol, Kurloff cells were preferentially accumulated along the corticomedullary junction extravascularly. Later the distribution was more diffuse. The conspicuous accumulation of Kurloff cells in the corticomedullary region could reflect an inability of Kurloff cells to use blood vessels as a route for migration. These findings strongly suggest the afferent migration of Kurloff cells into the thymus via lymphatics.

5'-Nucleotidase↗
PubMed1997

Enzyme-histochemical demonstration of the intramural lymphatic network in the monkey jejunum.

The structural organization of the intramural lymphatic networks in the jejunum of the Japanese monkey (Macaca fuscata) was studied by an enzyme-histochemical method using whole-mount preparations of tissue layers. A distinction between the lymphatics and the blood vessels was made by light microscopy using 5'-nucleotidase (5'-Nase)-alkaline phosphatase (ALPase) double staining. In each tissue specimen, the reaction product for 5'-Nase activity was localized in the lymphatic vessels, whereas that for ALPase activity was restricted to blood vessels. The mucosal layer exhibited an irregular network of tubular lymphatics connecting to the central lymphatics in the villi. The submucosal layer revealed a horizontal mesh-like network consisting of tubulo-saccular lymphatics. A dense maze-like network of lymphatics was distributed throughout the myenteric layer. The lymphatic networks were independent of the blood vessels. The present results indicate the usefulness of the enzyme-histochemistry of whole-mount preparations of the laminar layers for demonstration of the structure and distribution of the lymphatic system in the intestinal wall.

5'-Nucleotidase↗