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Biomedical subjects

Y Inada

Publications and source records attributed to Y Inada.

At least 127 records · Page 7Linked to original sources
PubMed1990

Cooperativity between platelet-activating factor and collagen in aggregation of bovine platelets III.

In cooperative aggregation of bovine platelets induced by simultaneous addition of PAF and collagen at subthreshold concentrations the following observations were made. (i) Formation of phosphatidic acid and arachidonic acid metabolites, which characterize PAF and collagen alone-induced aggregation, respectively, was observed very obviously. (ii) A thromboxane antagonist did not completely block the cooperative aggregation. The extent of residual aggregation activity was dependent on concentration of collagen used in the simultaneous administration with PAF. These results suggest that both signal transduction pathways activated by PAF and collagen alone at high concentrations are attained by simultaneous addition of both agonists at subthreshold concentrations through unknown mechanisms.

Animals↗
PubMed1990

Retinoic acid-induced differentiation-specific, C-kinase-dependent phosphorylation of cytosolic 44 and 32 kDa proteins in HL-60 cells.

The effect of various differentiation-inducers on the activity of Ca2+, phospholipid-dependent protein kinase (C-kinase) activity and endogenous protein phosphorylation by the kinase were examined in the extracts of HL-60 cells. Although all of the inducers, retinoic acid, dibutyryl cAMP, nicotinamide, dimethylsulfoxide, and 3-aminobenzamide increased the cytosolic C-kinase activity accompanied with the differentiation into mature myelocytes, only retinoic acid markedly enhanced Ca2+, phospholipid-dependent phosphorylation of 44 and 32 kDa proteins in the cytosol. These results suggest that the differentiation pathway induced by retinoic acid is different from the pathways induced by other inducers.

Benzamides↗
PubMed1990

Cooperativity between platelet-activating factor and collagen in aggregation of bovine platelets, II.

When subthreshold amounts of platelet-activating factor (PAF) and collagen were added simultaneously, strong aggregation of platelets was induced. However, each agonist alone at these concentrations could not induce aggregation at all (S. Kojima et al, (1987) Biochem. Biophys. Res. Commun. 145, 915-920). This cooperativity was observed not only in aggregation but also in changes of intracellular Ca2+ concentration, 47 kDa protein phosphorylation, and formation of thromboxane. These findings suggest that various steps of signal transduction pathways are enhanced during their cooperativity.

Animals↗
PubMed1990

Response of fibronectin to liver regeneration after hepatectomy.

The relationship between plasma fibronectin concentration and the regenerative process in liver remnants after hepatectomy was studied in 12 patients and in male Sprague-Dawley rats with and without cirrhosis. Plasma fibronectin levels were reduced immediately after hepatectomy in humans and rats. Patients and rats without cirrhosis displayed preoperative fibronectin levels within 1 mo and 1 wk, respectively, but low fibronectin levels persisted longer in those with cirrhosis. Plasma fibronectin levels correlated well with the degree of hepatic regeneration in the patients with cirrhosis (r = 0.4227; p less than 0.05) and without cirrhosis (r = 0.8148; p less than 0.001), and also with the percentage of change in liver weight during regeneration in the rat with thioacetamide-induced cirrhosis (r = 0.4905; p less than 0.01) or in the rat without cirrhosis (r = 0.6422; p less than 0.001). These results suggest that plasma fibronectin is a useful marker for the detection of regenerating liver.

Adult↗
PubMed1990

Reconstruction of the triangular fibrocartilage complex after surgery for treatment of synovial osteochondromatosis of the distal radioulnar joint.

Synovial osteochondromatosis of the hand is uncommon, except for tenosynovial chondromatosis of the digits. It is even more rare in the wrist joint. A patient with synovial osteochondromatosis of the distal radioulnar joint that involved the triangular fibrocartilage complex is described. At operation, synovectomy, excision of osteochondral bodies, and removal of the entire triangular fibrocartilage complex was done. The triangular fibrocartilage complex was reconstructed using part of the extensor carpi ulnaris tendon. One year after operation, the patient had regained almost full range of motion and is without pain.

Cartilage, Articular↗
PubMed1990

Arteriovenous shunt in digit replantation.

From May 1958 to May 1987, 331 digits were replanted successfully with an overall survival rate of 86.2%. Complete success in replantation of amputated fingers requires an accurate anastomoses of both arteries and veins. However, anastomosis between arteries may not be possible in some patients. Since reports that a thumb amputated at the interphalangeal joint area could be successfully replanted by an arteriovenous shunt on the palmar side, we did arteriovenous shunts in four such cases. Two replantations were successful; necrosis developed in the other two patients.

Adult↗
PubMed1990

An experimental study of the venous flap: investigation of the recipient vein.

In previous studies using rabbit ears, total venous perfusion flaps (TVPF) were used that did not contain in the experimental model any chosen arteries truly representative of clinical venous flaps. We discovered that the TVPF could survive even under conditions of poor blood circulation. In the present study, conditions of the recipient veins were investigated using flow-through veins in TVPFs of rabbit ears and human dorsal digital veins. The research suggested that conditions for TVPF survival are a high density of the venous network in the flap and the presence of venous oscillation, high oxygen tension, and effective blood flow in the recipient vein.

Adolescent↗
PubMed1990

Continuous local intraarterial infusion of antithrombotic agents for epigastric flap transfer in rabbit.

In free tissue transfer, the recipient arteries and veins are often damaged by injury, and their lumens are often narrowed due to thickening of the intima. These factors are considered paramount in the poor success rate of free tissue transfers. In the reported study, the authors examined the effects of continuous intraarterial infusion with heparin and urokinase in experimental epigastric flap transfer. By intraarterial infusion, the drug concentration at the target site could be significantly increased. The viability of an epigastric flap transferred to a recipient site with thickened arterial intima was significantly improved in a rabbit model by a seven-day continuous local intraarterial infusion of heparin at 10 U/kg/hr and urokinase at 100 IU/kg/hr, compared with control or intravenous infusion. Use of an anticoagulant with a fibrinolytic enzyme is considered to be the best choice for a successful outcome in flap transfer.

Abdomen↗
PubMed1990

Activation of kallikrein-kinin system in human plasma with purified serine protease from Dermatophagoides farinae.

An aqueous extract from a mite culture, of Dermatophagoides farinae, activated prekallikrein to kallikrein in normal plasma. Crude protein preparation, obtained by ammonium sulfate precipitation (95% saturation) from the extract, exhibited high activity (0.81 units/mg protein) towards a synthetic substrate of coagulation factor XIIa, Boc-Gln-Gly-Arg-MCA, and had also activity to form kallikrein in human plasma deficient in coagulation factor XII. Treatment of the protein preparation with phenylmethylsulfonyl fluoride (PMSF), an inhibitor of serine enzyme, gave rise to inactivation of both activities. Thus, the serine protease specific for Boc-Gln-Gly-Arg-MCA in mite cultures of D. farinae was purified by ammonium sulfate precipitation and chromatographies on p-aminobenzamidine-sepharose CL-4B, DEAE-Toyopearl 650M, Sephadex G-75 superfine and Sephacryl S-200. The purified protease was homogeneous electrophoretically, and its molecular weight was estimated to be 30,000. The optimum pH and temperature were around 7.5 and 50 degrees C, respectively. The specific activity was 36 units/mg protein at pH 7.4 and 37 degrees C. The activity was completely inhibited by PMSF. The serine protease had the activity to activate the kallikrein-kinin system in normal human plasma.

Animals↗
PubMed1990

Antagonistic action of AA-2414 on thromboxane A2/prostaglandin endoperoxide receptor in platelets and blood vessels.

AA-2414, (+/-)-7-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-7-phenylheptanoi c acid, inhibited the aggregation of guinea pig platelets induced by a prostaglandin endoperoxide (PGH2) analogue, U-44069 and the specific binding of another analogue, [3H]U-46619 to washed guinea pig platelets with IC50 values of 3.1 x 10(-7) and 8.2 x 10(-9) M, respectively. AA-2414 competitively inhibited the contraction of rabbit aorta and pig coronary arteries induced by U-44069 with pA2 values of 8.3 and 9.0, respectively. AA-2414 also inhibited the contraction of rabbit aorta induced by PGF2 alpha (pA2: 7.8) and the contraction of pig coronary arteries induced by PGF2 alpha, PGD2 and 9 alpha,11 beta-PGF2 with pA2 values of 7.8, 8.6 and 7.8, respectively. But, AA-2414 had no effect on the antiaggregatory effect of PGD2 on the aggregation of guinea pig platelets. In experiments with guinea pigs ex vivo, AA-2414 (0.1-1 mg/kg, p.o.) dose-dependently inhibited the platelet aggregation induced by U-44069; the inhibition at a dose of 1 mg/kg was 100% at 1 hr and was 89% even at 24 hr after the administration. The thromboxane (TX) A2/PGH2 receptor antagonistic action of AA-2414 was stereospecific. These results show that AA-2414 is a potent, orally active and long acting TXA2/PGH2 receptor antagonist. In addition, AA-2414 has PGF2 alpha, PGD2 and 9 alpha,11 beta-PGF2 antagonistic effects.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1990

Indications for surgical treatment of putaminal hemorrhage. Comparative study based on serial CT and time-course analysis.

Serial computerized tomography (CT) scans were correlated with a precise time-course analysis of the neurological condition of 180 patients with hypertensive putaminal hemorrhage. All patients entered the study within 3 hours of the ictus. In this series, 111 patients were treated conservatively and 69 surgically. The neurological condition of each patient was measured by means of a newly proposed grading system for intracerebral hemorrhage-intracranial hemorrhage (ICH grade) which is a modification of the Glasgow Coma Scale. Serial CT scans revealed that most hemorrhages were completed within 6 hours after ictus. Based on the ICH grade at 6 hours postictus, a clinical classification of the severity of putaminal hemorrhage was defined: fulminant, rapidly progressive, slowly progressive, and nonprogressive. According to this classification, precise time courses of the ICH grade were compared between the conservative and surgical treatment groups in a 7-day postictal period. Activities of daily living at 6 months after ictus were also compared. Surgical treatment for a rapidly progressive hemorrhage appears to be beneficial if undertaken in patients under 65 years of age. Surgery in a slowly progressive hemorrhage should be considered only in a small number of patients who deteriorate neurologically with conservative treatment. In this series of patients, surgical treatment of fulminant and nonprogressive hemorrhage was not likely to improve the quality of life or functional recovery. Regardless of treatment modality, CT provided evidence that patients with anterior capsular hemorrhage (16% in this series) showed good recovery of motor and speech function.

Activities of Daily Living↗
PubMed1990

[A clinical evaluation of distant metastases from a hepatocellular carcinoma with reference to location, frequency, symptoms, treatment & prognosis].

A clinical analysis of patients with hepatocellular carcinoma (HCC) associated with a distant metastases has been undertaken by the authors. Studied were eight patients (Group A) whose distant metastases were detected at the time of their initial examination, and 24 patients (Group B) whose distant metastases had been diagnosed during the course of treatment of their primary lesions. Complications arising from liver cirrhosis in Group A was less than in Group B. The location of the metastases were the bone in 16, the lung and the adrenal gland in four, the brain and the skin in two and the kidney in one. The mean survival times were 4.6 months (Group A), and 6.3 months (Group B). The cause of death was chiefly a progression of the primary lesion, except for one brain metastases. This analysis had shown that treatment of a bone metastasis is necessary for the relief of pain, and that care should be taken for the prevention of a fracture or paralysis, and that control of the primary lesion is necessary for improving the chances of survival.

Adrenal Gland Neoplasms↗
PubMed1990

[Hemodynamic features of hypotension induced by nicardipine in dogs].

Hemodynamic features of hypotension induced by nicardipine were studied in 18 mongrel dogs under 0.87% halothane in oxygen (1MAC). They were randomly allocated to one of two groups. Group C received no vasodilator therapy and served as control and group N received infusion of nicardipine. Mean arterial pressure decreased and was maintained at 60 mmHg for 60 minutes in group N. No change was noted in hemodynamic variables measured in group C throughout the experiment. During and after induced hypotension in group N, cardiac index (CI), stroke volume index (SVI), central venous pressure (CVP), and right ventricular stroke work index (RVSWI) increased significantly compared with the control values. On the other hand, systemic vascular resistance (SVR) was significantly reduced, reaching 25% of the control value at the end of hypotension period. Heart rate showed a progressive increase but not significantly. Left ventricular maximum dp/dt showed a moderate increase during hypotension, but then decreased gradually to the control value after induced hypotension. Left ventricular stroke work index (LVSWI) and pulmonary vascular resistant (PVR) were unchanged from the control value during and after induced hypotension. The data indicate that nicardipine is a potent systemic vasodilator with hyperdynamic hemodynamic effects in addition to significant increase in right ventricular function.

Animals↗
PubMed1990

[The effect of CO2 absorbent shape on its functioning time].

A comparative investigation into the functioning time of three brands of CO2 absorbents was performed. The three investigated brands were: Viosorb, Wakolime, and Wakolime-A. In this study PICO2 was measured to know the drug's functioning time and CO2 elimination from the model lung fixed at 200 or 300 ml.min-1. PICO2 was less than 1 mmHg for 34 to 55 hours at VCO2 of 200 ml. min-1 and for 32 to 48 hours at VCO2 of 300 ml.min-1. PICO2 increased exponentially in all CO2 absorbents. There were statistically significant relation between PICO2 and time. The CO2 absorbent whose shape is tablet has the longest functioning time because it could be placed smoothly in the canister. It is concluded that the shape of CO2 absorbent plays a role in determining its functioning time.

Absorption↗