Search PubMed⌕ Search

Biomedical subjects

S Shibata

Publications and source records attributed to S Shibata.

At least 505 records · Page 28Linked to original sources
PubMed1991

M. cervico-humeralis--a case report.

An abnormal muscle, so-called M. cervico-humeralis, was found bilaterally in a 50-year-old Japanese male in a dissection practice at Jikei University in 1989. This is the third report of the cervico-humeral muscle in Japan, and the first case which occurred bilaterally. Both muscles were similar in shape, origin, course, and insertion. The flat and triangular-shaped muscle arose by tendinous slips from the transverse processes of the sixth and seventh cervical vertebrae (VC6 and VC7). These two tendons converged to form a single slip which passed through the brachial plexus. This single slip became a muscle running obliquely downward and laterally together with the brachial plexus and subclavian vessels to reach the medial surface of the humerus. The muscle inserted linearly by a thin flattened tendon into the lower end of the lesser tubercle and into the medial lip of the intertubercular sulcus of the humerus. The supplying nerve originated directly from the posterior cord of the brachial plexus in both muscles. The artery to the right cervico-humeral muscle arose from the axillary artery together with a branch to the subscapular muscle.

Cervical Vertebrae↗
PubMed1991

Studies on the constituents of Scutellaria species. IV. High performance liquid chromatography of glucuronylflavonoids in Scutellaria ikonnikovii juz.

Recently several procedures have been reported for the simultaneous separation of flavonoid glycosides by high performance liquid chromatography (HPLC), and reversed phase column is more suitable than normal phase column. Even so, the simultaneous separation of flavonoids with closely related structures is not easy. We investigated a successful procedure for the simultaneous separation of glucuronyl flavonoids with 5-hydroxyl group by using a reversed phase column combined with gradient elution in the constituent studies of Scutellaria ikonnikovii Juz.. We have also studied the relationship between the retention time and the position of hydroxyls and glucuronyls in the chemical structure.

Chromatography, High Pressure Liquid↗
PubMed1991

Suppression of lipoprotein lipase in 3T3-L1 cells by a mediator produced by SEKI melanoma, a cachexia-inducing human melanoma cell line.

Production of a cachexia-inducing factor(s) by the SEKI melanoma cell line, established from a human melanoma, has been well documented. Conditioned medium from cultures of this melanoma cell line contains a factor(s) that inhibits the activity of lipoprotein lipase (LPL) in fully differentiated 3T3-L1 adipocytes. The mode of inhibition of this enzyme by the factor, i.e. its dose-dependency and time course, is very similar to that of LPL-inhibition by a macrophage-derived cachexia-inducing factor, cachectin/tumor necrosis factor (cachectin/TNF). However, the conditioned medium of SEKI melanoma cells does not contain any immuno-reactive substances reactive in enzyme-linked immunosorbent assay (ELISA) with anti-cachectin/TNF antibody, or with anti-interleukin 1 alpha or beta antibodies. This LPL-suppression factor present in the conditioned medium seems to be a peptide because of its heat-lability and apparent molecular weight of more than 25,000. The conditioned media from cultures of four other different cell lines were found to show no significant suppression of LPL activity. These results imply that SEKI melanoma cells produce a cachexia-inducing factor(s) similar to cachectin/TNF but that the molecule involved is different.

Animals↗
PubMed1991

Role of the medical museum in teaching medical students.

We describe the Educational Museum of Modern Medicine of Kawasaki Medical School of Kurashiki, Japan, and its use in medical education. The extraordinary speed of recent medical advances confronts medical educators with many difficulties. With the aim of improving medical education at our school, we have imposed some roles of medical education, especially regarding pathology, on the medical museum, because it has attracted students to a greater extent and facilitated their independent learning in a more fruitful way than the audiovisual materials previously available in our library. We hope to provide some insights for the improvement of medical education and lead to enthusiastic discussion of this matter.

Education, Medical↗
PubMed1991

[Primary intracerebral malignant lymphoma of the aged].

Primary intracerebral malignant lymphoma is non-Hodgkin's lymphoma originating in the central nervous system. It is a rare disease, comprising 1% of all brain tumors and 1.6% of extranodal non-Hodgkin's lymphoma, but its frequency has increased recently in aged patients. The ages of the 10 patients (8 men and 2 women) ranged from 31 to 79 years and average 56 years. In 5 patients over 60 years old (mean age 72), a solitary lesion was found in 2 patients and multiple lesions in 3 patients on a contrast-enhanced scan. One patients are still alive, but 4 died, after surviving 4 months on average. In 5 patients under 60 years old (average 39), single lesion were present in 4 and multiple in 1. Two patients are still alive three patients have died. Their median survival was 4 years and 11 months. In conclusion, primary intracerebral malignant lymphoma increased frequency in aged patients. Their tumors were generally larger and more often multiple, and their prognosis was definitely poor.

Adult↗
PubMed1990

Synthesis of the alpha and beta anomer of an N-triglycosyl dipeptide.

O-alpha-D-Glucopyranosyl-(1----6)-O-beta-D-glucopyranosyl-(1----6)-1-N- [L-aspart-1-oyl-(L-proline)-4-oyl]-alpha- and -beta-D-glucopyranosylamine have been prepared, as models for a derivative possibly present in the glomerular basement membrane of rats, by condensation of the corresponding D-glucosyl-dipeptide derivatives with 2,3,4,2',3',4',6'-hepta-O-acetyl-alpha-D-isomaltopyranosyl bromide in the presence of mercuric cyanide, followed by deprotection of the trisaccharide-dipeptide derivatives.

Amino Acid Sequence↗
PubMed1990

Supersensitivity to tetrodotoxin and lidocaine of anthopleurin-A-treated Na+ channels in crayfish giant axon.

Anthopleurin-A produced two distinct responses in crayfish giant axons: depolarization and prolongation of action potentials. The depolarization was prominent at low concentrations of anthopleurin-A, while a remarkable prolongation of the action potential was produced by higher concentrations of anthopleurin-A. Both effects of anthopleurin-A were inhibited by pre- or posttreatment with tetrodotoxin or lidocaine at concentrations which had not effect on the normal sodium channel. The prolongation of the action potential was more sensitive to tetrodotoxin and lidocaine than the depolarization was. These results suggest that sodium channels of the crayfish giant axon are modified by anthopleurin-A in at least two ways, thereby resulting in sensitization to tetrodotoxin and lidocaine.

Action Potentials↗
PubMed1990

Clonotypes of anti-DNA antibodies expressing specific idiotypes in immune complexes of patients with active lupus nephritis.

IEF, using 6 M urea, provides a unique opportunity to analyze the spectrotypes of antibodies in immune complexes (IC) in vivo. Using this technique, we have analyzed the clonotypes of anti-DNA antibodies expressing specific Id in the circulating IC of patients with active lupus nephritis. Serum anti-ssDNA and anti-dsDNA antibodies showed heterogeneous spectrotypes. The antibodies isolated from circulating IC had a restricted clonotype and a neutral charge and were directed mainly to ssDNA and, to a lesser extent, to dsDNA. These samples failed to form complexes with DNA when they were subjected to absorption to a DNA-coupled Sepharose column. Anti-DNA antibodies expressed specific Id, termed O-81 or NE-1, which were detected only in the IC of patients with active lupus nephritis. Anti-DNA clonotypes, including O-81 and NE-1 idiotypes, were also found in the eluates of renal glomeruli of lupus patients. These results indicate that subpopulations of anti-DNA antibodies in circulating IC are limited, and may play an important role in the pathogenesis of lupus nephritis.

Antibodies, Antinuclear↗
PubMed1990

Urinary neutral glycosphingolipid analysis of patients with Fabry's disease; rapid isocratic elution from high-performance liquid chromatography as per-o-benzoyl derivatives.

Neutral glycosphingolipids from urinary sediments of six patients with Fabry's disease and 11 members of the family of one propositus were analyzed using high-performance liquid chromatography. Per-o-benzoyl derivatives of GlcCer, LacCer, GbOse3Cer and GbOse4Cer were clearly resolved by a solvent mixture of hexane/dioxane/isopropanol (75:25:1, v/v) on a normal-phase silica column. Using our isocratic solvent system, the analysis was completed within 15 min. The smallest amount of glycolipid that could be detected by HPLC was 50 pmol and a linear response was shown at 230 nm up to 400 pmol. The calculated peak area of GbOse4Cer was higher than those of GlcCer, LacCer and GbOse3Cer. The molar ratios of GbOse3Cer to monohexosyl ceramide (CMH) in the urinary sediments were: Fabry hemizygotes, 36.33 +/- 25.54 (n = 6); heterozygotes, 0.94 +/- 0.50 (n = 4); and controls, 0.11 +/- 0.06 (n = 5). The molar ratio CDH/CMH was also higher in patients (8.42 +/- 6.23) than in controls (0.77 +/- 0.23). The female H was a rare example of a carrier with typical clinical manifestations. From the urinary sediment analysis, females E, G and J were suspected to be Fabry heterozygotes, although no clinical signs were observed at the time of examination.

Chromatography, High Pressure Liquid↗
PubMed1990

KT-362 related effects on intracellular calcium release and associated clinical potential: arrhythmias, myocardial ischemia, and hypertension.

The following discourse addresses the pharmacologic profile of KT-362, its clinical potential as an anti-arrhythmic agent with associated hypotensive effects, as well as its additional related potential in myocardial ischemia and related sequellae, and the specific cellular actions that may be responsible for these potential therapeutic effects. Although these include specific actions on both sodium and calcium entry, the focus is on the relevance of independent effects on calcium release. KT-362 relaxes arterial smooth muscle, concomitantly reducing the total peripheral resistance and mean arterial blood pressure. Vascular relaxing actions are attributed primarily to inhibitory effects on calcium release and secondarily to inhibitory effects on calcium entry via both potential-gated and receptor-linked channels. The "intracellular calcium antagonist" properties are correlated with a decrease in the production of the major second messenger, inositol 1,4,5-trisphosphate, which is responsible for calcium release and a concurrent ryanodine-like action that further decreases the amount of calcium released. Ventricular arrhythmias associated with coronary occlusion, cardiac glycosides, catecholamines, and chloroform are prevented by KT-362. General antiarrhythmic properties are associated with a use-dependent block of the "fast" sodium channel, primarily in the activated state, with ancillary effects on the "slow" calcium current. More selective effects on arrhythmias specifically associated with delayed after-depolarizations are attributed to effects on calcium release. In myocardial ischemia, KT-362 primarily reduces myocardial oxygen consumption rather than increases oxygen supply. The former is accomplished by depressing myocardial contractility and reducing afterload, while the latter is associated with a limited effect on coronary collateral blood flow. The negative inotropic effect is fundamentally related to its effects on calcium release, with additional contributions from its effects on calcium entry. Thus, the one intrinsic property of KT-362 that consistently emerges as significant and relevant in cardiovascular disease is the capacity to diminish calcium release.

Animals↗
PubMed1990

Measurements of the isometric contractile forces generated by dog periodontal ligament fibroblasts in vitro.

One hypothesis for the mechanism of tooth eruption is that the periodontal ligament fibroblasts generate the eruptive force. To assess the force generated, these fibroblasts were obtained by explant culture of ligament from mandibular premolars of a dog and were cultured in collagen gel matrices. The forces generated by them under isometric conditions were continuously measured for 120 h with a strain gauge. At the same time the number of cells in the gel was counted and the force measured was calculated as the force generated by 10(4) cells. Shortly after the start of culture, the force per 10(4) cells increased rapidly; it reached 5.2 X 10(-4) N at 8 h, and then remained at the same level for about 48 h. Our findings suggest that fibroblasts of the periodontal ligament may generate sufficient force for tooth eruption.

Animals↗
PubMed1990

Massive osteolysis of the maxillofacial bones. Report of two cases.

Two cases of massive osteolysis were encountered, one affecting the mandible and the other the maxilla and mandible. Only 13 cases have been reported so far in the existing literature for massive osteolysis of the mandible. It is indeed a rare disease. Our two cases were surgically treated and were clinically and histopathologically assessed.

Aged↗
PubMed1990

The inhibitory effect of quinacrine on contractile responses to norepinephrine in isolated rabbit aorta.

1. In rabbit aorta, quinacrine, but not indomethacin nor nordihydroguaiaretic acid, inhibited contractile responses to norepinephrine and KCl. Amiloride and nifedipine did not affect the effect of quinacrine. 2. In Ca2(+)-free medium, quinacrine (3 x 10(-6)-10(-4) M) inhibited the norpinephrine response less than that to a subsequent addition of Ca2+. 3. M&B 22, 948, nitroglycerin and forskolin inhibited the Ca2+ response. The effect of quinacrine was inhibited by M&B 22,948, but not by forskolin and potentiated by nitroglycerin. 4. Quinacrine and M&B 22,948 potentiated the nitroglycerin-relaxation. The effect of quinacrine plus M&B 22,948 was not different from that of quinacrine. 5. These results indicate that the effect of quinacrine may be different from that of nifedipine but is related to cGMP.

Amiloride↗
PubMed1990

Effects of GABA and anxiolytics on the single unit discharge of suprachiasmatic neurons in rat hypothalamic slices.

The effects of gamma-aminobutyric acid (GABA), muscimol, baclofen and the anxiolytics; diazepam (DZP), flurazepam (FZP) and zopiclone on single-unit neural activities in the suprachiasmatic nucleus (SCN) were investigated using the rat hypothalamic slice preparation. Exposure of the slice to GABA 10(-4) M produced inhibitory responses in 65% of the 49 SCN neurons examined. The threshold concentration of GABA ranged from 10(-6) to 10(-4) M. Neurons responsive to GABA were not found to be restricted to a subdivision of the SCN, but were diffusely distributed throughout the nucleus. DZP, FZP and zopiclone produced responses similar to those of GABA. The inhibitory effects of GABA (10(-5) M) were potentiated by coadministration of DZP (10(-5) M). Muscimol and baclofen (10(-7) M to 10(-4) M) also inhibited SCN neuronal activity in a dose-dependent manner. Bicuculline (10(-5) M-10(-4) M) scarcely affected the baclofen-induced inhibition (1/6) but strongly antagonized the effects of muscimol (6/6), GABA (6/8) and DZP (4/5). These results suggest that the receptors mediating the inhibitory effects of GABA and anxiolytics within the SCN may be GABAA and/or GABAB or GABA-BDZ receptor complex, respectively.

Animals↗
PubMed1990

Structures of Angular Pyranocoumarins of Bai-Hua Qian-Hu, the Root of Peucedanum praeruptorum1.

Three new angular-type dihydropyranocoumarins, peucedanocoumarin I ( 1), peucedanocou-marin II ( 2), peucedanocoumarin III ( 3), and a known coumarin having the same skeleton, pteryxin ( 4), were isolated from the crude drug "Bai-Hua Qian-Hu" of the Q-II type series, which is the root of PEUCEDANUM PRAERUPTORUM Dunn. (Umbelliferae). The chemical structures of 1, 2, and 3 have been established by physicochemical methods to be 3' ( S)-2-methylbutyryloxy-4'-( R)-acetoxy-3',4'-dihydroseselin, 3'( S)-acetoxy-4'( R)-angeloyloxy-3',4'-dihydroseselin, and 3'( S)-acetoxy-4'( R)-tigloyloxy-3',4'-dihydroseselin, respectively.

Journal Article↗
PubMed1990

Studies on the anti-tumor-promoting activity of naturally occurring substances. IV. Pd-II [(+)anomalin, (+)praeruptorin B], a seselin-type coumarin, inhibits the promotion of skin tumor formation by 12-O-tetradecanoylphorbol-13-acetate in 7,12-dimethylbenz[a]anthracene-initiated mice.

Since Pd-II [(+)anomalin, (+)praeruptorin B], a seselin-type coumarin, was found to inhibit tumor promoter induced phenomenon in vitro, the effect of Pd-II on the in vivo tumor-promoting action of 12-O-tetradecanoylphorbol-13-acetate (TPA) in 7,12-dimethylbenz[a]anthracene-initiated mouse skin was investigated. Pd-II, applied 40 min before the TPA treatment, at a dose of 10 mumol/painting, completely suppressed tumor formation up to 20 weeks of tumor promotion, without any toxicity. Besides Pd-II, various anti-tumor-promoter coumarins were found in the traditional Chinese medicine Qian-Hu, from which Pd-II was obtained. These coumarins may be useful for the development of an effective method to prevent cancer.

9,10-Dimethyl-1,2-benzanthracene↗