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Biomedical subjects

H Shibayama

Publications and source records attributed to H Shibayama.

At least 37 records · Page 2Linked to original sources
PubMed1995

Laminin and fibronectin promote the chemotaxis of human malignant plasma cell lines.

We examined chemotaxis of human plasma cells (PCs) in response to extracellular matrix proteins (ECMs) in the human PC cell lines FR4ds and OPM-1ds. The FR4ds cells expressed beta 1+, beta 3-, alpha 2-, alpha 3-, alpha 4+, alpha 5+, alpha 6+, and alpha v+ integrins, whereas the OPM-1ds cells expressed beta 1+, beta 3-, alpha 2-, alpha 3+, alpha 4+, alpha 5-, alpha 6+, and alpha v+. Fibronectin (FN) and laminin (LN) promoted the chemotaxis of the PCs. An inhibitory assay with anti-integrin monoclonal antibodies (MoAbs) showed that anti-alpha 4 MoAb partially inhibited the chemotaxis of FR4ds and completely inhibited the chemotaxis of OPM-1ds. Anti-alpha 5 MoAb alone had no effect on either of these two lines. Nevertheless, anti-alpha 5 MoAb completely inhibited chemotaxis when it was added with anti-alpha 4 in FR4ds, demonstrating a novel complementary role of VLA-5 toward VLA-4 in the chemotaxis induced by FN. LN facilitated chemotaxis both in OPM-1ds expressing alpha 3 and alpha 6 integrins and in FR4ds expressing alpha 6 integrin alone. Anti-alpha 6 MoAb completely inhibited FR4ds chemotaxis, whereas anti-alpha 3 and -alpha 6 MoAb had synergistic inhibitory effects on the chemotaxis of OPM-1ds. These results indicated that the distribution of PCs in human tissue are determined by at least two factors: the concentration of the ECM proteins FN and LN and the expression of integrins.

Antibodies, Monoclonal↗
PubMed1995

Non-invasive method to detect motor unit contractile properties and conduction velocity in human vastus lateralis muscle.

The contractile properties and conduction velocity of motor units are estimated by using surface array electrodes during voluntary isometric contractions of the human vastus lateralis muscle. The subjects develop and maintain sufficient force to steadily discharge a given motor unit, assisted by visual feedback from an oscilloscope. The torque curve developed around the knee joint is triggered by an individual motor unit and averaged. 31 motor units in five subjects are studied. The twitch tension detected ranges from 3 to 27 m Nm with a mean of 12.3 m Nm. The threshold force ranges from 1.88 to 10.12 Nm with a mean of 5.48 Nm, which is 3% of the maximal voluntary contraction. The rise time ranges from 56 to 106 ms with a mean of 83 ms. The mean value of conduction velocity is 4.64 m s-1. The twitch tension is positively correlated to the threshold force (r = 0.839, p < 0.01), but has no relation to the other parameters. It is concluded that the use of non-invasive surface array electrodes provides the contractile properties of motor units and muscle fibre conduction velocity during weak contractions.

Electromyography↗
PubMed1995

Secondary amyloidosis associated with Castleman's disease.

A rare case of secondary amyloidosis associated with Castleman's disease is reported. A 53-year-old woman was referred for investigation of proteinuria. Biopsy specimens from kidney and gastric mucosa revealed numerous amyloid deposits, defined as AA amyloidosis by immunohistological staining. Castleman's disease was found in the abdomen as the primary disease for the amyloidosis. Although the urinary protein was somewhat reduced and the inflammatory findings were improved after removal of the lymphoma, renal insufficiency progressed and hemodialysis was begun.

Amyloidosis↗
PubMed1995

[The expression pattern of adhesion molecules and their role of the tumor cells in patients with multiple myeloma].

The expression pattern of beta 1 integrin on the surface of tumor cells in patients with multiple myeloma (MM) is reviewed and compared with that of other B cell malignancies. The expression pattern of beta 1 integrin of plasma cells of healthy individuals was also compared with that of malignancies of plasma cells. Normal immature CD10+ B cell precursors in bone marrow are alpha 4+ and alpha 5+, while mature peripheral B cells are alpha 4+ and alpha 5+. In contrast to mature peripheral B cells, it is reported that plasma cells are alpha 4+ and alpha 5+. There are three points following in the phenotype characteristic of MM cells; (i) MM cells are alpha 4 strong positive, (ii) MM cells are beta 1 strong positive and (iii) MM cells are alpha 6strong positive. Because alpha 6+ cell lines of malignant plasma cells showed spread and chemotaxis on stimulation with laminin, alpha 6 beta 1 integrin might contribute of MM cells to transit laminin rich basement membrane of blood vessel to exit to the extravascular space. The difference of the phenotype between plasma cells and MM cells is the expression of alpha 5; plasma cells express alpha 5, but MM cells are lost in one half of the cases. The functional role of VLA-5 in MM cells is reviewed.

Amino Acid Sequence↗
PubMed1995

Effects of interferon-alpha on L-BCGF- and TNF-alpha-induced proliferation of hairy cell leukemia in Japan.

Interferon-alpha (IFN-alpha) is very effective in patients with hairy cell leukemia (HCL), although its mechanism of action is still unknown. To investigate this issue, we studied the in vitro response to IFN-alpha of a variant type of HCL, recently reported by us as the Japanese variant. Their clinical response to IFN-alpha (remission rate 35.7% in the multicenter study in Japan) was inferior to that of typical HCL (remission rate 80%; mean of previous reports). We found that both low molecular weight B-cell growth factor (L-BCGF) and tumor necrosis factor-alpha (TNF-alpha) induced the proliferation of HC from patients with the Japanese variant, as well as those with typical HCL. While, in typical HCL, IFN-alpha strongly inhibited the in vitro proliferation of HC induced by L-BCGF and TNF-alpha, the inhibitory effect of IFN-alpha on L-BCGF and TNF-alpha-induced proliferation was low in most Japanese variant patients. These in vitro findings may be related to the extent of clinical efficacy of IFN-alpha in the Japanese variant, obtained in the multicenter study. Since the degree of inhibition was parallel in L-BCGF- and TNF-alpha-induced proliferation in three patients examined simultaneously, it appeared that the antiproliferative effect of IFN-alpha is not specific to individual growth factors. Rather, IFN-alpha might affect fundamental growth mechanisms triggered by these factors.

Cell Division↗
PubMed1994

[Effect of training on the strength of cervical muscle].

The purpose of this study was to observe the effect of concentric and eccentric training on the strength of cervical muscle. The subjects were 18 adult males of whom 6 were exposed to concentric training, 6 were exposed to eccentric training, and 6 were exposed to control. Training intensity was the exertion of maximum isotonic strength on the extension, flexion, left bending and right bending of the neck. All training exercises for concentric and eccentric groups were given 10 times a set, 3 sets in a day, 3 times a week for 8 weeks. The changes in the strength of cervical muscle and in the girth of neck due to muscular training were measured regularly once a week. The results were as follows: 1) Maximum isometric strength increased significantly (p < 0.001) by 37.8% in concentric training group, and 39.6% in eccentric training group. No significant difference of strength increase was observed between concentric and eccentric training group. There was a significant decrease in the strength of cervical muscle in the early stage of muscular training, accompanied by severe muscle fatigue, but a remarkable increase in strength due to concentric and eccentric training was observed during the 8 weeks. 2) The girth of neck increased significantly (p < 0.001) by 4.9% in concentric training group, and 5.5% in eccentric training group. Significant difference of girth increase was observed after 3 and 4 weeks of muscular training of cervical muscle, meanwhile the girth of neck increased slightly by 1.3% in control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[The effect of the motion of forefoot joint at the force exerted upon the floor during walking exercise].

In walking exercise the human body is exposed to external forces. Some of them are produced by constraints such as surface, shoes or opponent. In kick action of walking, the ground reaction force (GRF) is the most important external force. The magnitude of the GRF, its direction, and point of application have an influence on the load on the human body. The purpose of this study is to clarify the role of forefoot joint (artt. metatarsophalangeae) at the force exerted upon the floor during kick action of walking. The device used in this study to analyze the GRF and its three components consists of Kistler's force platform. Output from force transducer was collected online with a TEAC data recorder and MEM-4101 minicomputer. The impact force measurements were taken from the anterior-posterior force time curves at the take-off for 1 subject walking 10 trials at 2 m/sec with 2 different pairs of shoes (Shoes 1: thin sole of 4mm, and Shoes 2: thick sole of 40mm) and without shoes. High speed (200f/sec) cinematography was also used to analyze the angular displacement of forefoot joint at the take-off of walking exercise. The force acting at the forefoot joint may produce the anterior-posterior force of the GRF which is defined as the propelling power acting on the human body during walking exercise. The result showed that the impact force peak occurred 40-60 msec before take-off and the propelling part of kick action accounted for only about 6% of the external force.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise↗
PubMed1993

[Multiple myeloma and adhesion molecules].

The physiological role of fibronectin (FN) on the human plasma cells were examined using three PC cell lines, FR4ds, OPM1 and OPM1ds. FR4ds was reactive with anti-VLA-alpha 4 and anti-alpha 5. In contrast, OPM1 and OPM1ds were not reactive with anti-VLA-alpha 5. FN induced spreading in FR4ds and OPM1ds. Albumin blocked these spreadings. FR4ds with mature plasma cell phenotype of alpha 4+ and alpha 5+ was more sensitive for FN than OPM1 and OPM1ds with immature phenotype of alpha 4+ and alpha 5-. Spreading cells proliferated more than floating cells. All these cell lines showed chemotaxis toward FN. alpha 5+ FR4ds was more sensitive for FN than OPM1 and OPM1ds with alpha 5- phenotype. These new abilities of PC of spreading and chemotaxis we found are summarized to be an affinity to organs. It is likely that alpha 4+ and alpha 5- PC with low affinity to organs are stored in peripheral blood as a result. We examined the chemotaxtic activity of myeloma cells in bone marrow and these in pleural effusions in a patient with multiple myeloma. These cells in pleural effusions showed more chemotaxic activity than these in bone marrow. FN induced growth, production of Ig, and motility of PC, which resulted in the augmentation of humoral immunity.

Bone Marrow Cells↗
PubMed1992

Granulovacuolar degeneration in the hippocampal cortex of aging and demented patients--a quantitative study.

The occurrence and topographic analysis of granulovacuolar degeneration (GVD) in the hippocampal cortex of mentally normal controls (75 cases) and patients with Alzheimer's dementia (AD; 17 cases which included Alzheimer's disease and senile dementia of Alzheimer type), multi-infarct dementia (MID; 16 cases), Pick's disease (PD; 5 cases) and atypical dementia [5 cases; non-Alzheimer, non-Pick dementia with Fahr's syndrome (NANPDF)] were investigated. GVD was rarely found in control cases below the age of 60 years. In elderly normal brains, the statistically most representative ranking order of predilection for GVD (in decreasing severity) was: in the 60 s, CA1 > prosubiculum > CA2 (no GVD was found in the CA3 and CA4); in the 70 s, CA1 > prosubiculum > CA2 > CA3 > CA4; in the 80 s, CA1 > prosubiculum > CA2 > CA3 > CA4; in the 90 s, CA1 > prosubiculum > CA2 > CA3 > CA4. In the brains of demented patients, the rank order for GVD was: for AD, CA1 > CA2 > CA3 > prosubiculum > CA4; for MID, CA1 > prosubiculum > CA2 > CA3 > CA4; for PD, CA1 > CA2 > CA3 > prosubiculum > CA4; and for atypical dementia (NANPDF), CA1 > CA2 > prosubiculum > CA3 > CA4. The similarity of the predilection to ranking order was noted both in normal aged subjects and in MID as well as both in AD and in PD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Ventilatory capacity and exercise-induced arterial desaturation of highly trained endurance athletes.

Recent evidence suggested that exercise-induced arterial O2 desaturation may occur in highly trained endurance athletes. So, Dempsey brought the hypothesis that the pulmonary capacity for oxygen transport cannot meet superior demands imposed by cardiovascular system in highly trained endurance athletes, and endurance training primarily causes adaptation in the skeletal muscles and in the systemic cardiovascular system, with little change in the pulmonary system. In the present study, we determined the propriety of the hypothesis due to measure the ventilatory capacity of endurance athletes. Sixteen highly trained endurance athletes (ET) and thirteen untrained subjects (UT) volunteered to participate in these experiments. All subjects performed the four experiments, 1) the highest oxygen uptake (peak VO2) during incremental cycle exercise and ventilation (VE), ventilatory equivalent for O2 (VE/VO2) and arterial O2 saturation (SaO2) at which peak VO2 was observed, 2) the maximal voluntary ventilation for 30 sec at rest (MVV), 3) the pulmonary diffusing capacity for CO (DLCO) and expressed per unit of alveolar lung volume (KCO) at rest by the single breath method, and 4) the ventilatory response to hypercapnia (S) at rest by rebreathing method, were measured. The peak VO2 of ET (66.7 ml.min-1.kg-1) was significantly (30.8%) higher than UT (52.4 ml.min-1.kg-1), and VE/VO2 and SaO2 of ET (29.3 and 93.7%, respectively) were significantly lower than UT (34.6 and 95.8%). There were no differences in VE, MVV, DLCO, and S between two groups.

Adult↗
PubMed1991

Effect of low blood glucose on plasma CRF, ACTH, and cortisol during prolonged physical exercise.

The effects of low blood glucose concentration during low-intensity prolonged physical exercise on the hypothalamus-pituitary-adrenocortical axis were investigated in healthy young men. In experiment 1, six subjects who had fasted for 14 h performed bicycle exercise at 50% of their maximal O2 uptake until exhaustion. At the end of the exercise, adrenocorticotropic hormone (ACTH) and cortisol increased significantly. However, this hormonal response was totally abolished when the same subjects exercised at the same intensity while blood glucose concentrations were maintained at the preexercise level. In experiment 2, in addition to ACTH and cortisol, the possible changes in plasma concentration of corticotropin-releasing factor (CRF) were investigated during exercise of the same intensity performed by six subjects. As suggested by a previous study (Tabata et al. Clin. Physiol. Oxf. 4: 299-307, 1984), when the blood glucose concentrations decreased to less than 3.3 mM, plasma concentrations of CRF, ACTH, and cortisol showed a significant increase. At exhaustion, further increases were observed in plasma CRF, ACTH, and cortisol concentrations. These results demonstrate that decreases in blood glucose concentration trigger the pituitary-adrenocortical axis to enhance secretion of ACTH and cortisol during low-intensity prolonged exercise in humans. The data also might suggest that this activation is due to increased concentration of CRF, which was shown to increase when blood glucose concentration decreased to a critical level of 3.3 mM.

Adrenocorticotropic Hormone↗
PubMed1990

Central distribution of the stapedius motoneurons in the rat--a study of topographical anatomy and HRP transport experiments.

A detailed anatomical description of the stapedius muscle area in the rat was given and on this basis the central distribution of the neurons innervating the stapedius muscle was investigated by the horseradish peroxidase transport method. The stapedius muscle showed a circum-pennate structure with a para-centrally located tendon and was composed of about 500 muscle fibers. It contained no special sensory structures and was innervated by a single branch of the facial nerve consisting of myelinated axons. Horseradish peroxidase experiments provided the following findings. The stapedius muscle received few sensory components. The stapedius motoneurons resided in the brainstem ipsilaterally in a column-like region ventromedial to the facial motor nucleus. Some of them (up to 6%) were scattered rostrally as far as the level of the facial nerve exit. Almost all the stapedius motoneurons showed fusiform morphology with significantly smaller mean diameter and lesser size variation than the facial nucleus motoneurons. The number of the stapedius motoneurons per animal on one side amounted about 150 which was about the same as that of axons in the stapedius nerve. Their axons except for those of rostrally scattered ones shared the intramedullary route with axons of the facial nucleus motoneurons.

Animals↗