Biomedical subjects

A Suehiro

Publications and source records attributed to A Suehiro.

63 records · Page 4Linked to original sources

PubMed1980

Mechanisms of shock blood induced tissue anoxia.

An isolated limb perfusion system in pigs was used to assess and relate hemodynamic variables to oxygen consumption in shock. Perfusion with shock blood results in a significantly increased peripheral vascular resistance, which can be blocked by phentolamine. However, a significantly reduced oxygen consumption seen during perfuslion with shock blood is not eliminated with phentolamine despite normal peripheral vascular resistance. The cause of the reduced oxygen consumption is not known, but the results suggest that other factors apart from a decreased blood flow due to catecholamine release are important in contributing to end organ anoxia and failure in shock.

Animals↗

PubMed1980

Intestinal blood flow at various intraluminal pressures in the piglet with closed abdomen.

The influence of intraluminal pressure on intestinal blood flow was studied in two segments of the small intestine and two of large intestine ligated after insertion of intraluminal catheters in ten piglets. Intestinal segments were inflated in stepwise increments in intraluminal pressures of 15, 30, 45 and 60 mmHg and blood flow was measured with radioactive microspheres using four isotopes (Ce, Cr, Sr, Sc). Other segments were inflated to a pressure of 60 mmHg and then pressure decreased in a stepwise fashion to 30, then 0 mmHg for the last two injections. Small and large intestinal blood flow fell progressively with increasing intraluminal pressure. At 60 mmHg a forward flow of 25% of normal was still present. Furthermore, not only was there an absolute decrease in blood flow with increasing intraluminal pressure but this decrease was disproportionately large in the intestinal mucosa. A hyperemic response lasting approximately 15 minutes was observed after complete decompression. The intestinal blood flow distal to the ligated segments was always moderately increased as compared to intestinal blood flow proximal to the segments. The results reported herein are at some variance from other reported studies performed with the abdomen open and on isolated segment preparations. The reasons for these variations are discussed.

Abdomen↗

PubMed1980

Small intestinal blood flow after 48 hours ileus, prostigmin and manual decompression.

In eight piglets small intestinal blood flow (IBF) and motility has been measured after 48 hrs mechanical obstruction, prostigmin application and manual decompression using the microspheres method. Intraenteric basic pressure is in a normal range; the number of tonic contraction waves (type 3 waves) is slightly increased. IBF after 48 hrs ileus is markedly increased compared to normal (218%). Prostigmin does not influence IBF significantly. After manual decompression, IBF decreases to 56% of normal and does not recover within 30 minutes. Whereas IBF in the segment proximal to the obstruction is increased, IBF in the distal part is significantly reduced (48%) after 48 hrs of ileus. It is concluded that 48 hrs of ileus have no harmful effect on intestinal blood flow and function. Prostigmin does not increase IBF, whereas motility is stimulated strongly. Mechanical decompression results in a 50% reduction of IBF, which might be in accordance with clinical observation of retarded recovery and reduced motility after this maneuvre.

Animals↗

PubMedDate not supplied

Evaluation of platelet hyperfunction in aged subjects using spontaneous platelet aggregation in whole blood.

To evaluate the changes in platelet function in connection with aging, spontaneous platelet aggregation in whole blood (SPAWB) from healthy aged people was measured and compared to that in the whole blood of young subjects as well as patients with old cerebral infarction. SPAWB was determined by the fall in non-aggregated single platelet count by stirring without adding platelet aggregating agents to whole blood. SPAWB in the aged subjects was significantly higher than that in the young volunteers. In patients with old cerebral infarction taking no platelet suppressive agents, SPAWB was also high but was suppressed to the level of that in young subjects by prescription of ticlopidine. Although when aspirin or a mixture of phosphocreatine and creatine phosphokinase (CP/CPK) was added in vitro to whole blood obtained from the aged subjects, SPAWB was inhibited to 50%, addition of the specific PAF (platelet activating factor) inhibitor TCV-309 induced only partial inhibition of SPAWB. Only CP/CPK showed more than 50% inhibition of SPAWB in the young volunteers. These findings suggest that platelet function in aged subjects is in a hyperaggregable state in vivo due to increased thromboxane A(2).

Journal Article↗

PubMedDate not supplied

Age-related augmentation of stroke tendency evaluated using plasma P-selectin levels.

Plasma soluble P-selectin is thought to be a useful marker for thrombotic diseases. To evaluate the thrombotic state and risk of stroke in aged healthy subjects, we investigated plasma P-selectin levels in healthy subjects and ischemic stroke patients. Plasma P-selectin was measured in 67 healthy subjects and 35 aged (>or= 65 years of age) patients with chronic ischemic stroke using a sandwich enzyme-linked immunosorbent assay (ELISA). Plasma P-selectin was significantly higher in aged (>or= 65 years of age) healthy subjects than in young (< 65 years of age) healthy subjects. Significant difference did not exist between aged healthy subjects and aged stroke patients who were not receiving anti-platelet agents. Anti-platelet agent had no significant effect on plasma P-selectin levels in aged stroke patients. The amounts of P-selectin released from platelets into the plasma after stimulation with adenosin diphosphate in young and aged healthy subjects were not significantly different. Elevated levels of P-selectin in aged healthy subjects suggests the existence of a subclinical thrombotic state which can result in a stroke. Elevated P-selectin levels are not thought to be due to platelet hyperfunction.

Journal Article↗

PubMedDate not supplied

Age related elevation of serum macrophage colony stimulating factor (M-CSF) level.

We recently reported that the serum level of macrophage colony-stimulating factor (M-CSF) was elevated in patients with cerebral infarction. In the present study, we measured serum M-CSF level, as well as coagulo-fibrinolytic markers and general laboratory tests in adult healthy subjects of various ages, and investigated the relationship between age and M-CSF level. M-CSF in aged subjects (>or=65 years of age) was significantly higher than that in the younger subjects (<65 years of age), and a significant positive correlation between age and M-CSF was found. Significant positive correlations between M-CSF, and plasma levels of thrombomodulin (TM), von Willebrand factor antigen (vWF), thrombin-antithrombin III complex (TAT), prothrombin fragment 1+2 (F1+2), d-dimer products cross-linked fibrin degradation products (d-dimer) and plasmin-antiplasmin complex (PAP) were also found. Among the general laboratory tests, there was only a significant correlation between M-CSF and serum creatinine; however, no significant correlation was found between M-CSF and other tests including blood cell counts. From these results, age-related elevation of serum M-CSF level was confirmed, and was suggested not to indicate the alteration of hemopoietic condition in aged subjects but to be related to thrombotic state or systemic damaged blood vessel in the apparently healthy aged people.

Journal Article↗

PubMedDate not supplied

Counting microaggregate particles in blood.

A method is described for measuring microaggregates in stored blood with an electronic particle counter avoiding the usual use of a hemolytic agent. To overcome red blood cell coincidence at low dilutions of the samples two different sized apertures were used. The method reliably measures microaggregates from 12.7 micron to 80.6 micron diameter. Hemolytic agents added to fresh blood were shown to induce the formation of microaggregates. The present study demonstrated that a tenfold reduction in a commonly used saponin concentration produced satisfactory hemolysis without inducing significant microaggregate formation. Hemolytic agents added to stored blood decreased the population of microaggregates significantly from that of unhemolyzed blood. This phenomenon was minimized with reduced saponin concentrations.

Adult↗

PubMedDate not supplied

Influence of atrial fibrillation on coagulo-fibrinolytic markers in patients with cerebral infarction.

To examine the influence of atrial fibrillation (Af) on stroke onset, we measured the plasma D-dimer level, thrombin antithrombin III complex and plasmin alpha 2 antiplasmin complex (PAP) in 46 stroke patients with Af and 87 stroke patients without Af. These marker levels were significantly higher in Af patients with stroke than in those without stroke (n = 16), and thus do not seem to be affected by Af alone. Abnormal values were also more frequent in acute Af stroke patients with visible occlusion of the major cerebral artery than in those without Af. The D-dimer and PAP levels in all Af stroke patients in the younger-aged patients (< or = 64 years) were significantly higher than those without Af, but not noted in the older-aged group (> or = 75 years). These results suggest that the D-dimer and PAP levels in younger-aged patients with Af indicate the existence of cerebral emboli due to Af.

Acute Disease↗

PubMedDate not supplied

Studies of the pathogenesis and management of thrombotic thrombocytopenic purpura.

We have studied the pathophysiological signs and methods of management of thrombotic thrombocytopenic purpura (TTP) in our TTP patients. We showed that anti-platelet GP II b- III a monoclonal antibodies bound to human vascular endothelial cells (HUVEC). The binding rate of 125I-anti-platelet GP II b- III a monoclonal antibodies to HUVEC treated with TTP patients sera was decreased, compared with the value observed for HUVEC treated with normal sera. These findings showed that GP II b- III a like substances are expressed on HUVEC and that TTP patients sera appear to contain anti-platelet GP II b- III a antibodies which may attack and injure the endothelial cells. PGI2 stabilizing activity of plasma is measured by PGI2 inhibitory activity attenuation on normal platelet aggregation induced by ADP. PGI2 stabilizing activity decreases in acute phase, increases in remission, suggesting that there may be a relationship between pathogenesis of TTP and decreases of PGI2 stabilizing activity. We also showed that PGI2 analogue (beraprost sodium) was useful for prevention of relapse of TTP. Plasmapheresis has emerged as the treatment of choice of TTP. We found the effectiveness of the high molecular weight fraction (HMW-F) of plasma in chronic TTP patients. HMW-F of plasma may contain the main factor necessary for improvement of TTP.

Adult↗