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Biomedical subjects

O Tanaka

Publications and source records attributed to O Tanaka.

At least 145 records · Page 8Linked to original sources
PubMed1993

The effect of nifedipine on monocrotaline-induced pulmonary hypertension in rats.

Effective drug therapy for pulmonary hypertension has not yet been developed. This study was designed to estimate the long-term hemodynamic and histopathological effects of nifedipine on severe pulmonary hypertension using animal models. Injection of one dose of monocrotaline produced subacute pulmonary hypertension in 7 week old Sprague-Dawley rats. Nifedipine (10 mg/kg) was administered intraperitoneally every day. For 5 weeks, bodyweight and hemodynamic parameters were measured, and right ventricle (RV) and left ventricle with septum (LV + S) were weighed separately. Medial thickness of the small pulmonary arterial wall was calculated by Suwa's method. Compared with the control group, the increase in right ventricular systolic pressure, total pulmonary resistance index, weight ratio of RV/(LV + S and medial hypertrophy in the nifedipine-treated rats were significantly limited without causing systemic hypotension. These results suggest that treatment with nifedipine may also be effective in attenuation of pulmonary hypertension when applied to humans.

Acute Disease↗
PubMed1993

Tannins and related compounds. CXXII. New dimeric, trimeric and tetrameric ellagitannins, lambertianins A-D, from Rubus lambertianus Seringe.

Chemical examination of the leaves of Rubus lambertianus Seringe (Rosaceae) has led to the isolation of four new ellagitannins, which were characterized on the basis of chemical and spectroscopic evidence to be dimers [lambertianins A (6) and B (7)], a trimer [lambertianin C (8)] and a tetramer [lambertianin D (10)], all having sanguisorbic acid ester group(s) as linking unit(s) between glucopyranose moieties. Furthermore, HPLC analyses of fifteen Rubus species collected in Japan and Taiwan revealed that the trimer (8) and the tetramer (10), together with sanguiin H-6 (1), occur widely in these species.

Chromatography, High Pressure Liquid↗
PubMed1993

Saponins from Vietnamese ginseng, Panax vietnamensis Ha et Grushv. Collected in central Vietnam. I.

From rhizomes and roots of Panax vietnamensis Ha et Grushv., Araliaceae, commonly known as Vietnamese Ginseng, two new acetylate saponins named vina-ginsenoside-R1 (13) and vina-ginsenoside-R2 (15) were isolated. On the basis of chemical and spectral data, 13 was formulated as monoacetyl 24(S)-pseudo-ginsenoside-F11 and 15 was proved to be monoacetyl majonside-R2. Besides the two new saponins and beta-sitosteryl-3-O-beta-D-glucopyranoside, sixteen known saponins were also isolated and identified. Dammarane saponins:ginsenoside-Rh1 and 20(R)-ginsenoside-Rh1 (1), ginsenosides-Rg1 (2), -Re (3), -Rd (6), -Rb3 (7), -Rb2 (8), -Rb1 (9), pseudo-ginsenoside-RS1 (= monoacetyl ginsenoside-Re, 4), notoginsenosides-R1 (5) and -Fa (10). Ocotillol-type saponins:pseudo-ginsenoside-RT4 (11), 24(S)-pseudo-ginsenoside-F11 (12), majonosides-R1 (16) and -R2 (14). Oleanolic acid saponins:ginsenoside-Ro (= chikusetsusaponin V, 17) and hemsloside-Ma3 (18), a saponin previously isolated from a cucurbitaceous plant, Hemsleya macrosperma C. Y. Wu. Despite having large horizontally elongated rhizomes, the underground part of this plant contains mainly dammarane saponins and a small amount of oleanolic acid saponins. In addition, the yield of ocotillol-type saponins, especially majonoside-R2, is surprisingly very high (more than 5% and ca. half of the total yield of saponin). This characteristic saponin composition has made Vietnamese Ginseng an interesting species among Panax spp.

Ginsenosides↗
PubMed1993

Morphological changes of unmyelinated nerves in the cerebral arteries after removal of the pterygopalatine ganglion--an electron microscopic study.

To investigate the participation of the pterygopalatine ganglion in the parasympathetic innervation of the cerebral arteries, Wallerian degeneration was evaluated in the unmyelinated nerves of the major cerebral arteries following the removal of the bilateral pterygopalatine ganglia in dogs. Several days after removal, transmission electron microscopy demonstrated typical features of degeneration in about one-third of the unmyelinated nerves, which are generally considered to be mostly autonomic, i.e., sympathetic and/or parasympathetic. Accordingly, removal of the pterygopalatine ganglion causes Wallerian degeneration of the sympathetic and/or parasympathetic nerves innervating the cerebral arteries. A supplementary study using monoamine fluorescence histochemistry demonstrated that there was no degeneration of the sympathetic nerves innervating the cerebral arteries. Therefore, the degenerated unmyelinated nerves are almost all parasympathetic. These experimental results support the concept that most parasympathetic nerves innervating the cerebral arteries originate in the pterygopalatine ganglion.

Animals↗
PubMed1993

[Immunohistochemical study of epidermal growth factor receptor and estrogen receptor in human thyroid tumors].

Expressions of epidermal growth factor receptor (EGFR) and estrogen receptor (ER) in human thyroid tumors were examined immunohistochemically in frozen sections. Forty-eight fresh surgical specimens of thyroid tissues, 19 carcinomas, 12 adenomas, 7 adenomatous goiters and 10 normal thyroid tissues were studied. All cases, including normal thyroid tissues, expressed the EGFR immunoreaction in the cytoplasm. Incidences of stronger than (+) staining intensity of EGFR were 84% (16/19) in carcinoma, 67% (8/12) in adenoma, 57% (4/7) in adenomatous goiter and 30% (3/10) in normal thyroid tissue. This result suggests that the staining intensity of EGFR expression is associated with malignant potential. The frequency of ER positive cases was 11% (2/19) in carcinoma, 17% (2/12) in adenoma and 0% in both adenomatous goiter and normal thyroid tissue. No relationship between EGFR and ER expression was recognized. However, a case of papillary carcinoma with strong ER immunoreactive intensity expressed weak EGFR intensity, suggesting an inverse relation in immunoreaction between EGFR and ER in papillary carcinoma.

Adenoma↗
PubMed1993

[Studies on triterpenoid constituents of the roots of Lantana camara].

Eight triterpenoids were isolated from the roots of Lantana camara. On the basis of their chemical properties and spectral data (UV, IR, MS, 1HNMR, 13CNMR), they were identified as lantanolic acid (I), 22 beta-O-angeloyl-lantanolic acid (II), oleanolic acid (III), 22 beta-O-angeloyl-oleanolic acid (IV), 22 beta-O-senecioyl-oleanolic acid (V), 22 beta-hydroxy-oleanolic acid (VI), 19 alpha-hydroxy-ursolic acid (VII) and 3 beta-isovaleroyl-19 alpha-hydroxy-ursolic acid (VIII). II was obtained for the first time from plant. VIII is a new compound named lantaiursolic acid.

Drugs, Chinese Herbal↗
PubMed1993

[Myocardial protection during aortic cross-clamping for more than 240 minutes].

The efficacy of cold crystalloid cardioplegia (St. Thomas II solution) during aortic cross-clamping more than 240 minutes was evaluated in 5 patients with non-coronary diseases undergoing heart surgery. The ischemic time ranged from 257 to 302 minutes with the mean of 274 minutes. As the technique of myocardial protection, multidose antegrade crystalloid cardioplegia was used at an interval of 20 minutes. These patient were compared with another patient group with clamping time 120-180 minutes. There was no difference between the two groups in terms of mortality, cardiac index, CK, CK-MB, GOT, LDH. These findings suggest that cold crystalloid cardioplegia provided clinically satisfactory myocardial protection during the aortic cross-clamping for more than 240 minutes.

Adult↗
PubMed1993

[A case of mediastinal neurinoma originated from the left vagal nerve].

A 46-year-old man was admitted to our hospital because of an abnormal shadow on the chest roentgenogram. The operation was performed through left posterolateral thoracotomy. A tumor mass, 4.5 x 2.5 x 2.5 cm in size, was found and its origin was the left main vagal nerve 0.5 cm distal the branching root of the recurrence nerve. The tumor and a part of the left vagal nerve was resected en bloc. Pathological study revealed tha the tumor was neurinoma of Antoni A+B. Postoperative course was uneventful. This is the 34th reported case in Japanese literature of neurinoma with its origin from the intrathoracic vagal nerve.

Cranial Nerve Neoplasms↗
PubMed1993

[Removal of a bronchial foreign body in a child using the laryngeal mask].

The laryngeal mask (LM) was employed for the removal of a bronchial foreign body (screw) in a 2-year-old boy weighing 16 kg since the 6.0 mm external diameter fiberoptic bronchoscope (FBS) for extraction forceps could not be used under tracheal intubation. Anesthesia was induced with sevoflurane in 100% oxygen. After injection of fentanyl 25 micrograms and vecuronium 2 mg, a gastric tube and a size 2 LM were inserted. Throughout the extraction procedure by the FBS in the left main bronchus, the boy had one lung ventilated manually. The airway pressure was kept under 15 cmH2O to avoid gas leakage around the cuff and gastric inflation. Oxygen saturation of 100% with pulse oximetry and PETCO2 of 35 to 45 mmHg with capnometry were maintained. The foreign body was extracted by biopsy forceps. A Fogarty catheter was not effective because the balloon tip was broken by the screw. The LM does not prevent regurgitation and does not provide adequate ventilation under increased airway pressure, but it facilitates the use of a larger size FBS equipped with a variety of extraction forceps. Therefore, it seems to be a useful device for the removal of bronchial foreign bodies in children.

Bronchi↗
PubMed1992

Stage-specific expression of cancer-associated type 1 and type 2 chain polylactosamine antigens in the developing pancreas of human embryos.

Expression of type 1 and type 2 chain carbohydrate antigens during the course of morphogenesis of human embryonic pancreas was investigated using specific monoclonal antibodies and compared with the carbohydrate antigen profiles of human pancreatic cancers. The type 2 chain antigens, such as stage-specific embryonic antigen 1 (Le(x)) and I-antigens, appeared much earlier than the type 1 chain antigens; the epithelial cells of primitive foregut were Le(x)+I-antigen- in the embryos at Carnegie stages 16-23, while the pancreatic primordial cells, which had differentiated from the Le(x)+ gut epithelial cells, were Le(x)-I-antigen+ at Carnegie stages 22-23. The type 1 chain antigens, such as Le(a), Le(b), Le(c), and their sialylated derivatives, were not expressed in any cells at these stages and appeared much later in the pancreas of the 10-12-week embryos, when the primitive pancreatic ductal cells in the primordia exhibited an extensive budding of the daughter cells. At this stage, Le(a) appeared and was expressed strongly in the epithelial cells of primitive pancreatic ducts as well as in the daughter cells that were destined to differentiate into future centroacinar cells; Le(b) was localized in the daughter cells which were to become future acinar cells; and Le(c) was specifically expressed in the daughter cells which were to form future Langerhans islets. With regard to the sialylated derivatives of Le(a), expression of the 2-3 sialyl Le(a) antigen was limited to the epithelial cells of the primitive pancreatic ducts, while the 2-6 sialyl Le(a) antigen was strongly expressed in the future centroacinar cells, which had differentiated from the corresponding daughter cells. Among these antigens, the Le(a) and 2-3 sialyl Le(a) antigens showed the highest incidence in human pancreatic cancer tissues. These results indicate that the expression of these carbohydrate antigens in embryonic pancreas is differentiation dependent and cell lineage specific and that most human pancreatic cancer cells mimic the carbohydrate antigen profile of the epithelial cells of the primitive pancreatic ducts in human embryos.

Adult↗
PubMed1992

Supra-neuroectodermal cells and fibers on the primary nasal cavity and in the fourth ventricle of mouse and human embryos: scanning and transmission electron microscopic studies.

Neuroectoderm-derived epithelia of the primary nasal cavity and the fourth ventricular floor and roof were observed by scanning (SEM) and transmission electron microscopy (TEM) and SEM-TEM correlative views in mouse embryos of 9th to 13th days of gestation, and in 38 externally normal human embryos ranging at Carnegie stages from 13 to 18 (about 5 to 7 weeks of gestation). Smooth-surfaced spindle-shaped cells with one or more cytoplasmic processes and cord-like cytoplasmic structures were observed by SEM on the wall of the primary nasal cavity of both species. They had morphological features similar to those of neuronal type 1 supraependymal (SE) cells and SE fibers on the floor and roof of the fourth ventricle in both species. Type 1 SE cells, SE fibers, and corresponding structures in the primary nasal cavity were localized in relation to the underlying developing nerve and vascular systems. Furthermore, their processes and fibers ran roughly parallel to these underlying structures and they penetrated the epithelial layer at the ends, suggesting a connection with underlying structures. From TEM and SEM-TEM correlative observations, SE fibers in the fourth ventricle and cord-like structures in the primary nasal cavity, both with a larger diameter, were deduced as single axon-like processes or bundles of processes. Those fibers and cord-like structures of smaller diameters were interpreted as elongated telophase bridges; both contained parallel packed microtubules and connected distant cells. Since these processes and fibers were generally longer and became fewer at later developmental stages, they appeared to be transient neuronal structures. They may play a development-related role in such morphogenetic cell movements as in the developing nerve and vascular systems in the epithelial and/or subepithelial layers, but not as direct rudiments of adult nerve tissues.

Animals↗
PubMed1992

Oleanane glycosides from Glycyrrhiza yunnanensis roots.

From the roots of Glycyrrhiza yunnanensis, collected in Yunnan, China, six new oleanane-type triterpene glycosides named yunganosides A1, B1, C1, D1, E2 and F2 were isolated together with hypaphorine. The structures of these glycosides were established by spectroscopic and chemical means.

Carbohydrate Sequence↗
PubMed1992

Timing and sequence of the events in the development of extraocular muscles in staged human embryos: ultrastructural and histochemical study.

The ultrastructure and the appearance of glycogen were studied in the extraocular muscles of 14 externally normal human embryos (Carnegie stages 13-21). At stage 16, myofibrils with an immature Z line and glycogen granules appeared in the cytoplasm of the myoblast. The myoblasts came into cluster at stage 18, and fusion between the myotubes was observed at stage 20. At this stage, an M line appeared in the myofibrils. At stage 21, an A band with a Z line and an H band with an M line were observed, the sarcoplasmic reticulum appeared in the cytoplasm of the muscle fibers and glycogen increased in volume in the cytoplasm. In the previous study, we showed that the muscle-specific isoenzymes, such as creatine kinase, beta-enolase and glycogen phosphorylase, appeared from stage 18 to 20 in the extraocular muscles. The previous findings and the present results suggest that the fusion of the muscle cells occurs in the period when some molecular markers of muscle differentiation are expressed in vivo.

Glycogen↗
PubMed1992

Immunohistochemical study of carbonic anhydrase III in the extraocular muscles of human embryos.

The differentiation of extraocular muscles was studied immunohistochemically in externally normal human embryos (Carnegie stages 13-23), using antibodies to carbonic anhydrase (CA) III and beta-enolase as the markers of type 1 and type 2 muscle fibers, respectively. At stage 18, some myoblasts were immunoreactive to beta-enolase antibodies, however, CA-III immunoreactivity was not observed around the optic vesicle. At stage 20, CA-III immunoreactivity appeared in some muscle fibers of extraocular muscles. From stage 21 to stage 23, CA-III-immunoreactive fibers increased and almost equalled the number of beta-enolase-immunoreactive fibers. These findings suggest that CA-III-immunoreactive type 1 fibers appear in the late stage of myogenesis compared with beta-enolase-immunoreactive type 2 fibers.

Carbonic Anhydrases↗
PubMed1992

Studies on single-dose toxicity of hydrophobically modified hydroxypropyl methylcellulose in rats.

Single-dose toxicological studies of hydrophobically modified hydroxypropyl methylcellulose (HM-HPMC, hydroxypropyl methylcellulose modified with stearylglycidylether) were conducted. A dispersion of HM-HPMC was administered to rats orally or by dermal application at doses up to 900 mg/kg. After the oral administration, the mean body weight of the 900 mg/kg group on the first day after administration was slightly but significantly lower (P less than 0.05) than that of the control group, and one rat had loose stools at 30 min. after the administration. No other abnormalities were noted. In the case of dermal application, no abnormalities were observed. No rats died, and no abnormalities in their organs were found by either route. In conclusion, there was no observed toxicity of HM-HMPC after oral or dermal administration at single dose up to 900 mg/kg under the conditions of these studies.

Administration, Cutaneous↗
PubMed1992

Primary dermal and eye irritability tests of hydrophobically modified hydroxypropyl methylcellulose in rabbits.

Primary dermal and eye irritation tests of hydrophobically modified hydroxypropyl methylcellulose (HM-HPMC, hydroxypropyl methylcellulose modified with stearylglycidylether), a new cellulose derivative used as a thickener for topical pharmaceuticals and cosmetics, were conducted in rabbits. A dispersion of HM-HPMC (3%) was applied to intact and abraded skins and reactions were observed. A very slight erythema was observed in both skins and this polymer was categorized as a "mild irritant". In the eye irritation test, with a dispersion of the same concentration, it was categorized as "marginal" in unrinsed eyes and "negative" in rinsed eyes.

Administration, Cutaneous↗