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Biomedical subjects

H Shimoda

Publications and source records attributed to H Shimoda.

At least 55 records · Page 3Linked to original sources
PubMed1996

Effect of cysteamine on gastric nerve fibers containing gastrin-releasing peptide in the rat.

In rats, changes in gastric nerve fibers containing gastrin-releasing peptide (GRP) in cysteamine-induced duodenal ulcer were investigated in relation to the dynamics of gastrin-producing cells (G-cells). Marked increases in gastric acid secretion and serum gastrin level were observed from 2 h after the administration of cysteamine. The number of G-cells was significantly decreased from 2 h after the injection of cysteamine. Two and 4 h after the administration of cysteamine, the G-cells showed ultrastructural changes characterized by a markedly decreased number of secretory granules. Circulating GRP levels were significantly elevated from 2 h after the administration of cysteamine. In the control group given vehicle only, nerve fibers showing immunoreaction for GRP formed a fine network in the gastric wall and were densely distributed in the oxyntic mucosa, located close to capillaries and demonstrated varicosities that contained either small clear vesicles or GRP-immunopositive vesicles with large cores. Eight h after the administration of cysteamine, there was depleted GRP immunoreactivity, evidenced by a markedly decreased number of vesicles, with large electron-dense cores, in the oxyntic mucosa. These findings suggest that, in cysteamine-induced duodenal ulcer, alterations in gastric nerve fibers containing GRP may be related to hypergastrinemia.

Animals↗
PubMed1996

Potent immunosuppressive principles, dimeric sesquiterpene thioalkaloids, isolated from nupharis rhizoma, the rhizoma of Nuphar pumilum (nymphaeaceae): structure-requirement of nuphar-alkaloid for immunosuppressive activity.

Potent immunosuppressants, the dimeric sesquiterpene thioalkaloids, 6-hydroxythiobinupharidine (2), 6,6'-dihydroxythiobinupharidine (3), 6-hydroxythionuphlutine B (5) and 6'-hydroxythionuphlutine B (6), were isolated from a natural medicine, Nupharis Rhizoma, the rhizoma of Nuphar pumilum (TIMM.) DC., through bioassay-guided separation together with five quinolizidine alkaloids (8, 9, 10, 11, 12). Dimeric sesquiterpene thioalkaloids (2, 3, 5, 6) were found to significantly inhibit anti-sheep erythrocyte plaque forming cell formation in mice spleen cells at 10(-6) M concentration. At this concentration, 2, 5 and 6 were found to exhibit no cytotoxicity to mice spleen cells, and 3 also showed only a little cytotoxicity. In addition, the inhibitory activity of several Nuphar alkaloids, dimeric sesquiterpene thioalkaloids (1, 4, 7, 8), and monomeric sesquiterpene alkaloids (9, 10, 11, 12) on anti-sheep erythrocyte plaque forming cell formation was examined and some structural requirement of Nuphar alkaloid for immunosuppressive activity was determined.

Animals↗
PubMed1996

Development of bioactive functions in hydrangeae dulcis folium. V. On the antiallergic and antimicrobial principles of hydrangeae dulcis folium. (2). Thunberginols C, D, and E, thunberginol G 3'-O-glucoside, (-)-hydrangenol 4'-o-glucoside, and (+)-hydrangenol 4'-O-glucoside.

Following the characterization of thunberginols A, B, and F, six bioactive principles, thunberginols C, D, and E, thunberginol G 3'-O-glucoside, (-)-hydrangenol 4'-O-glucoside, and (+)-hydrangenol 4'-O-glucoside, were isolated from Hydrangeae Dulcis Folium, the processed leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO, together with four kaempferol and quercetin oligoglycosides. Their chemical structures have been determined on the basis of chemical and physicochemical evidence. Thunberginols C, D, E, and G and (-)-hydrangenol 4'-O-glucoside showed antiallergic activity in the in vitro bioassay using the Schultz-Dale reaction. These components also exhibited inhibitory activities on the histamine release from rat mast cells and on the histamine-induced contraction in isolated guinea pig tracheal chain. In addition, thunberginols C, D, E, and G showed antimicrobial activities against oral bacteria.

Animals↗
PubMed1996

Development of bioactive functions in Hydrangeae dulcis folium. VI. Syntheses of thunberginols A and F and their 3'-deoxy-derivatives using regiospecific lactonization of stilbene carboxylic acid: structures and inhibitory activity on histamine release of hydramacrophyllols A and B.

Lactonization reaction of 2-carboxystilbene mediated by copper(II) chloride proceeded regiospecifically to give the five-membered lactone, while the bromolactonizations using N-bromosuccinimide and anodic oxidation were found to furnish the six-membered lactone. Using these regiospecific lactonization reactions as a key step, antiallergic and antimicrobial isocoumarins and the benzylidenephthalides thunberginols A and F and their 3'-deoxyanalogs were synthesized from phyllodulcin and hydrangenol. Two phthalides called hydramacrophyllols A and B were isolated from Hydrangeae Dulcis Folium and their stereostructures were determined on the basis of physicochemical and chemical evidence, which included the syntheses of hydramacrophyllols A and B from hydrangenol by the application of the lactonization method using copper(II) chloride. In addition, hydramacrophyllols A and B were found to exhibit an inhibitory effect on the histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.

Animals↗
PubMed1996

Bioactive constituents of Chinese natural medicines. II. Rhodiolae radix. (1). Chemical structures and antiallergic activity of rhodiocyanosides A and B from the underground part of Rhodiola quadrifida (Pall.) Fisch. et Mey. (Crassulaceae).

Two bioactive cyanoglycosides, rhodiocyanosides A and B, and two oligoglycosides, rhodioflavonoside [gossypetin 7-O-beta-D-glucopyranosyl(1-->3)-alpha-L-rhamnopyranoside] and rhodiooctanoside [octyl alpha-L-arabinopyranosyl(1-->6) beta- D-glucopyranoside), were isolated from the Chinese natural medicine "Si Lie Hong Jing Tian" (Shiretsukoukeiten in Japanese), the underground part of Rhodiola quadrifida (Pall.) Fisch. et Mey., together with four known compounds: rhodioloside, n-hexyl beta-D-glucopyranoside, gossypetin 7-O-alpha-L-rhamnopyranoside, and tricetin. The chemical structures of new glycosides were determined on the basis of chemical and physicochemical evidence. Rhodiocyanosides A and B exhibited inhibitory activity on the histamine release from rat peritoneal exudate cells sensitized with anti-2,4-dinitrophenyl IgE. Additionally, rhodiocyanoside A, the major constituent of this natural medicine, was also found to show antiallergic activity in a passive cutaneous anaphylaxis test in rat.

Animals↗
PubMed1995

Alteration in gastric nerve fibers containing gastrin-releasing peptide in relation to the gastrin-producing cell population after truncal vagotomy in a rat model.

The fine structural alteration in the gastric nerve fibers containing gastrin-releasing peptide (GRP) was studied in relation to the dynamics of gastrin-producing cells (G-cells) after truncal vagotomy in a rat model. The circulating gastrin levels were markedly elevated from the 1st day after vagotomy and the number of G-cells with positive immunoreaction for G17 and G34(1-15) was significantly increased in the vagotomized group. On the 3rd day after vagotomy, the G-cells showed conspicuous ultrastructural changes characterized by hypertrophy of the Golgi complexes and increased numbers of secretory granules. The GRP-positive nerve fibers formed a fine network in the gastric wall and were densely distributed in the oxyntic mucosa close to the blood vessels and showing varicosities composed of either small clear or GRP-positive large vesicles containing an electron-dense core. In the oxyntic mucosa of the vagotomized rats, axonal swelling of the nerves occurred on the 3rd day, and a depletion of GRP immunoreactivity was evidenced by a markedly decreased number of large-cored vesicles on the 7th day, when the serum GRP levels were also found to be markedly elevated. These findings indicate that the alteration in gastric nerve fibers containing GRP after truncal vagotomy may be related to hypergastrinemia and antral G-cell hyperplasia in the rat gastric mucosa.

Animals↗
PubMed1995

Rhodiocyanosides A and B, new antiallergic cyanoglycosides from Chinese natural medicine "si lie hong jing tian", the underground part of Rhodiola quadrifida (Pall.) Fisch. et Mey.

Two new antiallergic cyanoglycosides named rhodiocyanosides A and B were isolated from the Chinese natural medicine "Si Lie Hong Jing Tian" (Shiretsukoukeiten in Japanese), the underground part of Rhodiola quadrifida (Pall.) Fisch. et Mey., together with two new glycosides, octyl alpha-L-arabinopyranosyl(1-6)-beta-D-glucopyranoside and gossypetin 7-O-beta-D-glucopyranosyl(1-3)-alpha-L-rhamnopyranoside. Their chemical structures were determined on the basis of chemical and physicochemical evidence. Rhodiocyanosides A and B exhibited inhibitory activity on the histamine release from rat peritoneal exudate cells sensitized with anti-DNP IgE. In addition, rhodiocyanoside A was found to inhibit the PCA reaction in rats.

Animals↗
PubMed1995

Absolute stereostructures of hovenidulciosides A1 and A2, bioactive novel triterpene glycosides from hoveniae semen seu fructus, the seeds and fruit of Hovenia dulcis Thunb.

Two bioactive novel triterpene glycosides named hovenidulciosides A1 and A2 have been isolated from a Chinese natural medicine, Hoveniae Semen Seu Fructus, the seeds and fruit of Hovenia dulcis Thunb. (Rhamnaceae). The absolute stereostructures of hovenidulciosides A1 and A2 with a migrated 16,17-seco-dammarane skeleton have been determined on the basis of chemical and physicochemical evidence which included the X-ray crystallographic analysis of the p-bromobenzoate of their common aglycone, hovenidulcigenin A. Hovenidulciosides A1 and A2 exhibited inhibitory activity on the histamine release from rat mast cells induced by compound 48/80 or calcium ionophore A-23187.

Animals↗
PubMed1995

[Effects of thunberginol A contained in Hydrangeae dulcis forium on types I-IV allergies].

The inhibitory actions of thunberginol A on anti-allergic (type I-IV) activity were examined. Oral administration of thunberginol A 2 hr before the challenge significantly inhibited the PCA reaction (type I) in rats at a dose of more than 300 mg/kg and the ear PCA reaction in mice at a dose of more than 50 mg/kg. Thunberginol A at a dose of more than 300 mg/kg also significantly inhibited the allergic bronchoconstriction in rats. Thunberginol A concentration-dependently (10(7)-10(-4), 10(-5)-10(-4) M) inhibited the allergic contractions of rat trachea sensitized with IgE and those of the guinea pig lung preparation sensitized with IgG. It also inhibited the allergic histamine release from sensitized peritoneal exudate cells in a concentration-dependent manner (10(-5)-10(-4) M). Thunberginol A had anti-serotonic activity on the contraction of smooth muscle, and it increased the ear vascular permeability in mice. Thunberginol A significantly inhibited the primary response of contact dermatitis (type IV) in mice at 100 mg/kg from the day after immunization to the day before challenge, and it also inhibited the delayed type foot pad swelling in mice at a dose of more than 300 mg/kg at 0 and 8 hr after the challenge. These findings suggest that orally administered thunberginol A is effective against type I and type IV allergy.

Administration, Oral↗
PubMed1994

Development of bioactive functions in hydrangeae dulcis folium. III. On the antiallergic and antimicrobial principles of hydrangeae dulcis folium. (1). Thunberginols A, B, and F.

From the less polar fraction of Hydrangeae Dulcis Folium, the fermented and dried leaves of Hydrangea macrophylla Seringe var. thunbergii Makino, Eight antiallergic and antimicrobial principles were isolated together with several known compounds. Among the newly isolated bioactive constituents, the chemical structures of thunberginols A, B, and F have been determined on the basis of chemical and physicochemical evidence. Thunberginols A, B, and F were found to exhibit more potent antiallergic activity than phyllodulcin, hydrangenol, disodium cromoglycate (DSCG), and tranilast. In addition, these thunberginols showed antimicrobial activity against oral bacteria.

Animals↗
PubMed1994

[Development of bioactive functions in hydrangeae dulcis folium. II. Antiulcer, antiallergy, and cholagoic effects of the extract from hydrangeae dulcis folium].

In order to develop new bioactive functions of Hydrangeae Dulcis Folium, the fermented and dried leaves of Hydrangea macrophylla Seringe var. thunbergii Makino, effects of the methanolic extract from the crude drug on antiucler, antiallergic, cholagoic, and various pharmacological actions were investigated. Consequently, the methanolic extract was found to exhibit potent antiulcer, antiallergic, and cholagoic activities. By monitoring with these activities, it was found that the active constituents were contained in the lipophilic portion of the methanolic extract. Furthermore, the known lipophilic constituents such as phyllodulcin and hydrangenol were found to show little antiulcer and cholagoic activities, while it was also found that they showed antiallergic activity on Schultz-Dale reactions.

Animals↗
PubMed1994

Prognostic prediction in neuroblastomas: clinical significance of combined analysis for Ha-ras p21 expression and N-myc gene amplification.

Ha-ras p21 expression and N-myc gene amplification were examined in 69 neuroblastomas and their clinical significance was analyzed retrospectively. Thirty-nine (89%) of forty-four patients who survived for more than 2 years after diagnosis showed high Ha-ras p21 expression, whereas 19 (76%) of 25 patients who died of progressive disease showed low Ha-ras p21 expression in their tumors. Although all 14 patients whose tumors exhibited N-myc gene amplification died of the disease, 11 other patients (56%) who died did not exhibit N-myc gene amplification. When we considered both low Ha-ras p21 expression and N-myc gene amplification as risk factors, 23 (92%) of the 25 patients who died had at least one of the two and thus could have been predicted to be high-risk patients at diagnosis. The combined analysis of the two factors should provide more accurate information pertinent to patient care.

Child, Preschool↗
PubMed1993

Establishment and immunohistochemical characterization of an experimentally induced transplantable malignant schwannoma in the rat and two derived cell lines.

Oral administration of N-methyl-N'-nitro-N-nitrosoguanidine induced gastrointestinal tumors in 15 out of 19 rats: six adenomas, seven adenocarcinomas, one fibrosarcoma and one malignant schwannoma that was homotransplantable. Both the original and transplantable tumor exhibited characteristic morphological features and immunoreactivity identical to that of a human malignant schwannoma: positive reaction for S-100 protein, neuron specific enolase, glial fibrillary acidic protein, myelin basic protein and vimentin. In addition, alpha-smooth muscle actin was expressed in both tumors. Cultured tumor cells derived from the transplantable tumor at passage 3 produced 18 clones which showed anchorage independent growth in soft agar. From these clones, two cell lines showing characteristic immunoreactivity, designated as RMS-1 and 2, were established. In general, the immunoreactivities of the two cell lines were similar to those of the original tumor; however, the RMS-1 cell line demonstrated positive immunoreaction for neurofilaments and RMS-2 was negative for alpha-smooth muscle actin. Subcutaneous, injection of cultured cells from both cell lines into athymic BALB/c nude mice induced tumors identical to the original tumor. In the present study, transplantable malignant schwannoma was established in the rat and two phenotypes were isolated and established as cell lines.

Administration, Oral↗
PubMed1992

The proliferative kinetics of somatostatin-producing cells in the rat antral mucosa after truncal vagotomy.

The kinetics of somatostatin-producing cells (D-cells) in the rat antral mucosa after truncal vagotomy were studied using double immunostaining for bromodeoxyuridine (BrdU) and somatostatin. Both the concentration of somatostatin and D-cell density in the antral mucosa demonstrated a significant increase on the 3rd day after truncal vagotomy. With the single labeling of BrdU, a few D-cells showed positive immunostaining for BrdU throughout the experimental period in both vagotomized and sham operated rats. With cumulative labeling, the BrdU labeled cells demonstrated a linear increase in an identical number for each experimental time-point in both groups. The labeling index of BrdU in the D-cells increased significantly, beginning on the 3rd day and attaining a maximum level of 41.8% on the 10th day, in the vagotomized group after cumulative labeling. In this group, however, the density of D-cells with no immunoreactive BrdU also increased quickly on the 3rd day with cumulative labeling. The present study indicates that the most important factor involving D-cell hyperplasia observed after truncal vagotomy is the activation of pre-existing D-cells to synthesize and release hormones, together with the rapid replication of progenitor cells and their maturation to D-cells.

Animals↗
PubMed1992

[Upper and lower airway diseases in children with persistent cough].

Persistent cough is a frequent and frustrating problem in the pediatric field. One hundred and seventy two children presenting with persistent cough for longer than 2 weeks were evaluated by both otolaryngologists and pediatricians. One hundred and twenty nine cases (75%) were found to have lower airway diseases, of which bronchial asthma, bronchitis and pneumonia, in that order, were the most common. One hundred and forty two cases (82%) had sinusitis, in 34 cases of which no causative diseases except sinusitis were found to be responsible for the persistent cough. Sinusitis was found in 90% of patients with pneumonia, 81% of those with bronchitis and 65% of those with poorly controlled asthma cases. These results revealed that sinusitis is an important causative factor for persistent cough in children. All the patients with pneumonia and bronchitis were cured by antibiotic administration for 2 weeks, whereas conservative treatment of sinusitis for as long as 6 months was less satisfactory resulting in only 60% cure, 18% improvement and 22% without improvement. In cases with sinusitis and lower airway diseases, continuous treatment for sinusitis is necessary even after treatment of the lower airway diseases has been completed.

Adolescent↗
PubMed1991

A significant association of Ha-ras p21 in neuroblastoma cells with patient prognosis. A retrospective study of 103 cases.

To evaluate biologic characteristics of neuroblastoma, the authors examined the expression of Ha-ras gene (Ha-ras p21) in 103 primary tumors obtained at the time of diagnosis. Higher expression of the Ha-ras p21 in tumor cells showed a significant association with lower clinical stage of the tumor at diagnosis (chi-square = 35.418, degrees of freedom [df] = 9, P less than 0.001) and survival of the patients (chi-square = 37.111, df = 3, P less than 0.001). Thirty-six (84%) of 43 patients with decreased Ha-ras p21 expression died of aggressive disease. The Ha-ras DNA was examined in the 32 tumors by Southern blot analysis. Neither augmentation nor deletion of the Ha-ras DNA was observed. Amplification of the N-myc DNA was also examined in 43 cases in comparison with Ha-ras p21 expression. N-myc amplification was detected in 12 (55%) of 22 patients who died, and 19 (86%) of the 22 patients showed a low expression of the Ha-ras p21 in tumor cells. Eighteen (86%) of 21 survivors showed a high expression of the Ha-ras p21. The expression of Ha-ras p21 was thought to be a clinically important marker for prognosis in children with neuroblastoma.

Blotting, Southern↗
PubMed1991

IA antigen-positive epithelioid cells in experimentally induced granulomatous inflammation.

IA antigens on the cell membrane of inflammatory macrophages and epithelioid cells were investigated with immunoelectron microscopic method during development of granulomas induced by subcutaneous inoculation of 10(7) Mycobacterium lepraemurium into mice with and without hypersensitivity. In C57BL/6N (H-2b) immunogenetic high responder mice 6 weeks after infection majority (87%) of infiltrated cells were IA-positive. Two types of the staining reaction, strong and weak reactivity, were recognized among the positive cells. Strongly IA-positive cells showed lower phagocytosis (0.9/cell section) of mycobacteria than the weakly reacted cells (4.9/cell section). The strongly positive cells underwent morphological differentiation into large epithelioid cells during development of the hypersensitivity-type murine lepromas after 10 or more weeks of infection. Types of granulomas and IA-positive cells in C57BL/6N (nu/+) mice were identical to those found in C57BL/6N. In C57BL/6N (nu/nu) athymic nude mice initial infiltrating cells contained 38% of weakly IA-positive macrophages and a small number (7%) of strongly IA-positive macrophages. But the reactivity was lost later and only 4% of IA-positive cells remained in the granulomas without hypersensitivity. CBA/J (H-2k) low responder mice did not show IA-positive cells in either initial or late stage during the development of nonhypersensitivity-type murine lepromas. We suggest that the presence of IA-positive cells, particularly IA-positive epithelioid cells, in the lesions modulates the course of granulomatous tissue reaction in murine lepromas.

Animals↗