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Biomedical subjects

Y Inada

Publications and source records attributed to Y Inada.

At least 145 records · Page 8Linked to original sources

Triggering of the vascular permeability reaction by activation of the Hageman factor-prekallikrein system by house dust mite proteinase.

A 30-kilodalton (kDa) proteinase from the house dust mite Dermatophagoides farinae (Df-proteinase) was recently purified (Takahashi et al. (1990) Int. Arch. Allergy Appl. Immunol. 91, 80-85). In this paper we detailed the biological activities of the Df-proteinase. The activation of the kinin cascade by Df-proteinase was examined in vitro by using purified guinea pig Hageman factor (HF), prekallikrein (PK) and high-molecular-weight kininogen (HMWK) and the effect of this proteinase on endogenous human plasma proteinase inhibitors (serpins) and alpha 2-macroglobulin was tested. In addition, enhancement of the vascular permeability reaction in guinea pig skin by Df-proteinase was examined in vivo. These experiments showed that Df-proteinase could activate all the steps of the kinin-generating cascade, i.e., HF, PK and HMWK, and that Df-proteinase retained proteolytic activity even in the presence of an excess amount of endogenous proteinase inhibitors in plasma. We also found that the marked enhancement of the vascular permeability reaction was induced by Df-proteinase via the activation of the kinin-generating cascade without the release of histamine. From these results, we conclude that the proteinase of the house dust mite, Df-proteinase, has the potential to generate bradykinin and that the presence of this proteinase in biological systems would exacerbate inflammatory reactions in some pathological conditions.

Animals↗

Continuous local intra-arterial infusion of antithrombotic agents for replantation (comparison with intravenous infusion).

The success rate of replantation of amputated digits and limbs appears to be improved by local continuous intra-arterial infusion of urokinases, heparin and PGE1 at a daily dose of 240,000 I.U., 10,000 U, and 40 micrograms, respectively, for ten days, in comparison to intravenous infusion of the drugs. The purpose of this study was to investigate the difference between the haematological effects of intra-arterial and intravenous infusion. Accordingly coagulation and fibrinolytic enzyme levels were examined before, and at 4 and 12 hours after the start of infusion and on the 3rd and 10th postoperative days. Intra-arterial infusion was advantageous over intravenous infusion probably because the effect of general metabolism on drug levels was small, drugs exhibited immediate action and efficacy was localised. No particular side effects were demonstrated.

Blood Coagulation Factors↗

The sliding venous flap for covering skin defects with poor blood supply on the lateral aspects of fingers.

For the treatment of skin defects with poor blood supply on the lateral aspects of the fingers, particularly the radial side of the index finger and the ulnar side of the little finger which have been difficult to cover conventionally, we have developed the sliding venous flap. The flap can be moved by using the "sag" obtained from the dissected dorsal veins of the same finger. We have applied this technique in six cases with excellent results. The indications are limited to cases with only slight crushing of the dorsum of the finger. We consider this technique safe and effective in covering skin defects with poor blood supply on the lateral aspects of fingers.

Adolescent↗

An investigation of venous pressure and oxygen tension in human extremities: an experimental study of survival in pedicled venous flaps.

The pedicled venous flap is used at various sites, such as the finger, forearm, and leg. The authors previously reported that the reasons for the viability of such flaps, based on the digital dorsal vein and used for repairing digital skin defects in the earlier study, were high venous pressure or oxygen tension, as well as the possible effects of plasmatic imbibition and outflow through the draining vein. To investigate the importance of venous pressure and oxygen tension in the survival of these flaps at other sites in the body, measurements were made comparing these parameters in the digital vein, cephalic vein, and greater saphenous vein, which are all used clinically as draining veins in pedicled venous flaps. Although measurements in other sites were consistently lower than in the digital dorsal vein, since these other venous flaps are nevertheless viable in the clinical situation, their viability may not be due only to relatively high venous pressure and oxygen tension. The authors intend to carry out further comparative studies on plasmatic imbibition in the flap and outflow through the draining vein.

Adolescent↗

Isolation, characterization, and primary structure of a base non-specific and adenylic acid preferential ribonuclease with higher specific activity from Trichoderma viride.

In order to elucidate the structure-function relationship of RNases belonging to the RNase T2 family (base non-specific and adenylic acid-preferential RNase), an RNase of this family was purified from Trichoderma viride (RNase Trv) to give three closely adjacent bands with RNase activity on slab-gel electrophoresis in a yield of 20%. The three RNases gave single band with the same mobility on slab-gel electrophoresis after endoglycosidase F digestion. The enzymatic properties including base specificity of RNase Trv were very similar to those of typical T2-family RNases such as RNase T2 from Aspergillus oryzae and RNase M from A. saitoi. The specific activity of RNase Trv towards yeast RNA was about 13-fold higher than that of RNase M. The complete primary structure of RNase Trv was determined by analyses of the peptides generated by digestion of reduced and carboxymethylated RNase Trv with Staphylococcus aureus V8 protease, lysylendopeptidase and alpha-chymotrypsin. The molecular weight of the protein moiety deduced from the sequence was 25,883. The locations of 10 half-cystine residues were almost superimposable upon those of other RNases of this family. The homologies between RNase Trv and RNase T2, RNase M, and RNase Rh (Rhizopus niveus) were 124, 132, and 92 residues, respectively. The sequences around three histidine residues, His52, His109, and His114, were highly conserved in these 4 RNases.

Adenosine Monophosphate↗

Selective synthesis of 2,4-bis(O-methoxypolyethylene glycol)-6-chloro-s-triazine as a protein modifier.

2,4-Bis(O-methoxypolyethylene glycol)-6-chloro-s-triazine, a protein modifier with two polyethylene glycol chains (activated PEG2) was synthesized from monomethoxypolyethylene glycol and cyanuric chloride using zinc oxide as a catalyst by the improved method of a previous study (Matsushima et al., Chem. Lett. 7, 773, 1980). The product was identified as activated PEG2 without contamination of by-products with chromatographic and structural analysis.

Catalysis↗

[Endocrine effects of hypotension induced by diltiazem in rabbits].

Endocrine effects of hypotension induced by diltiazem, a calcium antagonist, were studied in 16 male rabbits under the inhalation of 0.7% halothane in oxygen. They were randomly allocated to one of two groups. Group C (n = 8) received no vasodilator therapy and served as control and group D (n = 8) received infusion of diltiazem. Mean arterial pressure was decreased and was maintained at 60 mmHg for 60 minutes in group D. No change was noted in plasma catecholamines measured in group C throughout the experiment but plasma renin activity decreased progressively. During and after induced hypotension in group D plasma epinephrine showed a dramatic rise compared with the control value. The maximum increase occurred 30 minutes after induction of hypotension but this change was not statistically significant. Plasma norepinephrine in group D was significantly higher than the control value. Compared with the control value (0.19 +/- 0.04 ng.ml-1), plasma norepinephrine was activated 30 and 60 minutes after induction of hypotension (0.71 +/- 0.16 ng.ml-1, P less than 0.05, 0.82 +/- 0.20 ng.ml-1, P less than 0.05, respectively). Plasma renin activity in group D was significantly higher than the control value. The highest level of plasma renin activity was three times the control value 30 minutes after induction of hypotension. In conclusion, our data show that induced hypotension by diltiazem activates the renin-angiotensin-sympathetic nervous system.

Animals↗

[Hemodynamic effects of endothelin in anesthetized dogs].

The purpose of the present study was to investigate and compare the hemodynamic responses that can be elicited in anesthetized dogs by intravenous administration of endothelin at rates of 300 (group E-I, n = 9) and 600 pmol.kg-1 (group E-II, n = 9) for 15 minutes. In group E-I, no significant pressure response was observed after administration of endothelin and cardiac index remained unchanged throughout the experiment. However, right and left ventricular work indices increased significantly but left ventricular maximum dp/dt and pulmonary vascular resistance decreased significantly. In group E-II, mean arterial pressure increased significantly by elevating systemic vascular resistance with marked decrease in cardiac index. However, right and left ventricular work indices remained unchanged throughout the experiment. On the other hand, each dose of endothelin significantly increased pulmonary capillary wedge pressure and left ventricular end-diastolic pressure but decreased heart rate. The present data revealed that the hemodynamic effects were different according to the doses of endothelin infused. In conclusion, our results show that endothelin (600 pmol.kg-1 BW) produces a long lasting increase in arterial pressure and endothelin-induced pressure responses are caused by an elevation in systemic vascular resistance.

Anesthesia, General↗

[Comparison of IVH and oral intake concerning the incidence of postoperative pulmonary complications (PPC)].

We compared IVH with oral intake concerning the incidence of postoperative pulmonary complication (PPC), using PPC score, in which the higher the score, pulmonary function is the worse. PPC score in IVH-group was higher than that in oral-group. Although it has been suspected that, on PPC score, long term IVH-group had the disorder of small airway functioning, the PPC in their group was not always high. In particular, among high score patients whose score was above 12 points in both groups, the PPC in IVH-group (30.4%) was lower than that in oral-group (60.0%). When we use PPC score, we should consider the difference in nutritional intake.

Aged↗

[A comparison of the endocrine effects of hypotension induced by nicardipine with those by sodium nitroprusside in dogs].

Plasma catecholamines, plasma renin activity, plasma aldosterone and plasma cortisol during hypotension induced by sodium nitroprusside and nicardipine were studied in 27 mongrel dogs under 0.87% halothane in oxygen. They were randomly divided into three groups: sodium nitroprusside (group S: n = 8), nicardipine (group N: n = 8) and controls (group C: n = 9). Group C received no vasodilator therapy and served as a control. Mean arterial pressure was reduced and maintained at 60 mmHg for 60 minutes in hypotensive groups. No changes were noted in plasma catecholamines and plasma cortisol in group C throughout the experiment, but plasma renin activity and plasma aldosterone decreased progressively. During hypotension induced by sodium nitroprusside and nicardipine, plasma epinephrine was significantly higher than the control value. However, after the hypotensive drugs were discontinued, plasma epinephrine decreased slightly. During and after induced hypotension, plasma renin activity of group N and group S were significantly higher than the control values. The highest levels of plasma renin activity 36.7 ng.ml-1.hr-1 in group N and 23.2 ng.ml-1.hr-1 in group S were observed. Plasma aldosterone concentration was significantly higher than the control value in group N. The maximum increase occurred 30 minutes after discontinuation of the nicardipine and the highest concentration of plasma aldosterone was three times control value. In contrast, in group S, plasma aldosterone was unchanged from the control value. Plasma cortisol concentration of group N was significantly increased than the control value. However, in group S, plasma cortisol concentration showed a slight but not significant increase.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗

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↗

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↗

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↗

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↗

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↗

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↗