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Biomedical subjects

M Motomiya

Publications and source records attributed to M Motomiya.

At least 109 records · Page 6Linked to original sources
PubMed1985

Distribution of fibronectin and other connective tissue components in human placenta.

Human placenta specimens obtained at term were investigated for distribution of fibronectin, collagens and glycosaminoglycans. When examined by the immunofluorescence staining technique with anti-plasma fibronectin antiserum, fibronectin was shown to be present around the fetal blood vessels and in the stroma of placental villi. The distribution of type IV collagen also was examined with specific antiserum. It was found that its distribution was similar to that of fibronectin. Conventional alcian blue staining indicated that the placental villi contained only small amounts of glycosaminoglycans. These data suggest that fibronectin and type IV collagen play important roles in tissue organization of the placental villi.

Chorionic Villi↗
PubMed1985

Effects of changes in chamber geometry by chronic pressure-overload on wall stress and strain as studied in the potassium-arrested canine left ventricle.

We studied differences in stress and strain distributions within the left ventricular wall between the normal heart and the pressure-overload hypertrophied heart. Diastolic left ventricular pressure-volume (P-V) relations of both ventricles were recorded using isolated potassium-arrested heart preparations. The P-V relations thus obtained were analyzed based on the large deformation theory. In this study, the left ventricle was assumed to be a thick spherical shell and its wall was assumed to consist of a homogeneous elastic material. In the hypertrophied heart, the wall stress at every layer of the diastolic left ventricle was smaller than that of the normal heart except in the close vicinity of the endocardial surface when compared at the same left ventricular pressure. Therefore, we concluded that the occurrence of concentric hypertrophy under pressure-overload may contribute in reducing the preload of the hypertrophied ventricle. It was thus suggested that the preload reserve of the pressure-overload heart exceeded that of the normal heart.

Animals↗
PubMed1984

Flow through a venous valve and its implication for thrombus formation.

To elucidate the possible connection between the flow patterns in the pockets of venous valves and thrombus formation, detailed studies of the behavior of model particles and red cells flowing through a venous valve have been carried out using isolated transparent dog saphenous veins containing two-leaflet valves, and cinemicrographic techniques. It was found that large paired vortices, located symmetrically on both sides of the bisector plane of the valve leaflets, were present in each valve pocket under physiological flow conditions. Particles continually entered the valve pockets from the mainstream, spending long periods of time describing a series of spiral orbits of decreasing diameter, while moving away from the bisector plane, and eventually left the vortex, rejoining the mainstream. With concentrated suspensions of red cells, it was found that another smaller counter-rotating secondary vortex, driven by the large primary vortex existed deep in each valve pocket. The concentration of red cells in this secondary vortex remained appreciably lower than that in the mainstream. In such regions, fluid circulated with extremely low velocities, thus creating a very low shear field which allowed red cells to form aggregates. The results suggest that in some pathological states, the valve-pocket vortices could act as automatic traps and generators of thrombi in a fashion similar to that previously demonstrated in an annular vortex formed downstream from a sudden tubular expansion.

Animals↗
PubMed1984

Biochemical and immunochemical comparison of fibronectin and polynectin from porcine plasma.

Polynectin, a glycoprotein of porcine blood plasma (also known as glycine-rich gelatin-binding protein (Isemura, M., Sato, N., and Yosizawa, Z. (1982) J. Biol. Chem. 257, 14854-14857] is similar to fibronectin with respect to binding characteristics to affinity gels. However, no immunoprecipitation reaction was observed either between polynectin and anti-fibronectin antiserum, or between fibronectin and anti-polynectin antiserum prepared in the present experiments. No cross-reaction was found between fibronectin and polynectin by enzyme-linked immunosorbent assays. Immunohistochemical studies revealed the presence in abundance of polynectin in intestinal and gastric glands. It was found that the pattern of distribution of polynectin was entirely different from that of fibronectin. Polynectin, in contrast to fibronectin, exhibited no cell attachment-promoting effects on BHK-21, a baby hamster kidney cell line, and a cell line of human embryonic lung fibroblasts. In addition, changes in binding characteristics to affinity gels after reduction and alkylation differed between polynectin and fibronectin. Although both proteins appear to have similar carbohydrate chains in view of the similar reactivities with lectins, the results of the present experiments demonstrated that polynectin is entirely different from fibronectin.

Alkylation↗
PubMed1984

Extraction of fibronectin from human normal and cirrhotic livers.

Tissue-associated fibronectin was extracted with 4 M urea from human normal and cirrhotic livers. The results of rocket immunoelectrophoresis indicated that the amount of fibronectin in cirrhotic liver was twice as much as that in normal liver. The collagen content was much higher in cirrhotic than in normal livers. These data suggested an important role of fibronectin in tissue fibrosis.

Fibronectins↗
PubMed1984

Left ventricular function of concentric hypertrophied heart after chronic pressure overload as studied in the isolated canine heart preparation.

The function of the pressure-overload left ventricle was studied in relation to the chamber geometry of the isolated canine heart. The occurrence of concentric hypertrophy was confirmed in dogs with aortic constriction 40 weeks after operation. The effect of the concentric hypertrophy on left ventricular function was then studied in five pressure-overload dogs. The end-diastolic pressure of the preparation was preset at 20 mmHg. In the pressure-overload ventricle, the end-diastolic volume was smaller by 47% (p less than 0.01) and the peak systolic pressure was higher by 24% (p less than 0.01) than the control at isovolumic beats. Ejection pressure was controlled by our afterload controlling system at various levels and kept constant during the ejection phase. When ejection pressure was the same, the difference in stroke volume between the experimental and control groups was not significant. In the pressure-overload ventricle, the slope (the reciprocal is Emax) of the regression line of the end-systolic volume on ejection pressure decreased (p less than 0.01) to 0.095 ml/mmHg by 47% from 0.186 ml/mmHg in the control. The volume-axis intercept (Vd) of the line was reduced to 55% of the control. A decrease in the regression line slope was in linear proportion to the degree of concentric hypertrophy, namely, to the change in chamber geometry. These results indicated that: Despite reduction of the end-diastolic volume, the concentric hypertrophied ventricle showed no reduction in stroke volume at the same level of ejection pressure, because of its improved capability to generate pressure. Emax was dependent on ventricular geometry.

Animals↗
PubMed1984

[Analysis of the possible mechanism for decrease of intracranial pressure following arousal stimulation].

Although decrease of intracranial pressure (ICP) and cerebral blood flow occurring following arousal from sleeping is well known phenomenon, its exact mechanism is poorly understood at the present time. The purpose of this study is to clarify its most possible mechanism, by analyzing clinical data mainly in comparison to the results obtained during hyperventilation. A small microtransducer, for ICP monitoring was placed over the dura at the time of closing of cranium and ICP was continuously recorded by ink-writing oscillograph. Systemic blood pressure, pulse and respiratory rates were continuously monitored and arterial PCO2 and pH before and after arousal stimulation were also determined. Above results are summarized as follows. There was no significant difference in time constant at decline of ICP between following arousal stimulation and hyperventilation, indicating that a response organ is the same between two groups and cerebrovascular wall is most likely as the response organ. However, since there was significant difference in time lag until initiation of decrease of ICP, the triggering mechanism for causing change of cerebrovascular tone must be different. In addition, there was no significant difference in arterial PCO2 and pH between at sleep and awake. On the basis of these results, the author concludes that rapid drop in ICP observed following arousal stimulation is due to neurogenic cerebral vasoconstriction.

Adult↗
PubMed1984

Lung clearance mechanisms in obstructive airways disease.

Using radioaerosol inhalation lung cinescintigraphy, pulmonary clearance mechanisms were studied in 21 patients with obstructive airways disease. In none of them did we find homogeneous deposition of inhaled radioaerosol in the lungs, or a steady, constant, axial, and cephalad transport of radioactivity in the major airways. Of the 21 patients, 14 showed temporary but frequent stopping and starting of radioactivity in the airways in the course of lung clearance; in ten there was reversal of flow; in five migration of radioactivity from one bronchus into the opposite, bypassing the trachea and often followed by shuttling between right and left bronchi; and in four there was spiral or zigzag transport of radioactivity. The overall lung retention ratio in the first 2 hr was not abnormal, but the airway deposition ratio was significantly above normal, and airway clearance efficiency was below. The alveolar deposition ratio was also significantly smaller in these patients.

Adult↗
PubMed1983

Glycosaminoglycans and glycoproteins in bronchoalveolar lavage fluid from patients with pulmonary alveolar proteinosis.

Bronchoalveolar lavage fluid from two cases of pulmonary alveolar proteinosis were analyzed for glycosaminoglycans and glycoproteins. The clinical courses of the two cases were entirely different. In one patient, signs and symptoms recurred despite repeated therapeutic bronchoalveolar lavages. In the other patient, three successive bronchoalveolar lavages brought about complete recovery. It was found that the bronchoalveolar lavage fluid from the former case contained various subtypes of glycosaminoglycans [hyaluronic acid, chondroitin sulfate A(C), dermatan sulfate, and heparan sulfate] and glycoprotein. On the other hand, the bronchoalveolar lavage fluid from the latter case contained glycoprotein, but no detectable amounts of glycosaminoglycans. There was only a slight qualitative difference in glycoprotein of bronchoalveolar lavage fluid between the two cases. The presence or absence of glycosaminoglycans in bronchoalveolar lavage fluid may be related to the prognosis of pulmonary alveolar proteinosis.

Adult↗
PubMed1983

Chemical analyses and antitumor activity of hydrosoluble substances from Mycobacterium bovis, strain BCG.

Hydrosoluble substances from BCG were prepared by cold water extraction and by hot phenol-water extraction. Chemical analyses revealed that both of them were derived from cytoplasm. The cold water extract (CWE) was effective in the treatment of C3H/He mice which had received an intraperitoneal inoculation of a syngeneic ascites hepatoma, MH134. The growth of a graft in footpad of mastocytoma P815 in CDF1 mice was retarded by intraperitoneal injections of CWE. A peptidoglycan from cell wall prepared by digestion with lysozyme exerted no antitumor activity in the same experimental condition as for the evaluation of antitumor effect of CWE. These results indicate that the antitumor activity of CWE was not due to the presence of a cell wall component.

Animals↗
PubMed1983

Flow visualization in isolated transparent natural blood vessels.

A novel technique to prepare isolated transparent natural blood vessels was developed and used to study the detailed flow patterns in some regions of the circulation. It was found that paired spiral secondary flows and recirculation zones form downstream of venous valves, at the arterial T-junctions in the dog abdominal aorta, and in the human carotid sinus over a wide range of geometrical and flow conditions, including the time-averaged mean values of the physiological flow rates.

Animals↗
PubMed1982

A biochemical study on glycosaminoglycans (mucopolysaccharides) in emphysematous and in aged lungs.

Quantitation of glycosaminoglycans (GAGs) in the lungs from different age groups indicated that the amount of GAGs was lower in the group 70 yr of age and older compared with that in the groups 30 to 39 and 40 to 49 yr of age, respectively (p less than 0.05). There was no difference in the relative ratio of individual GAG species (hyaluronic acid: chondroitin sulfate (A(C): dermatan sulfate: heparan sulfate) of the lung among the groups 40 to 49, 50 to 59, 60 to 69, and 70 or more yr of age. Hence, it was suggested that senescence of the lung was associated with a uniform decrease of all the GAG species in the lung. On the contrary, emphysematous lungs were characterized by a decrease in relative percentage of hyaluronic acid in comparison with control lungs (p less than 0.01).

Adolescent↗