Biomedical subjects

Y Inada

Publications and source records attributed to Y Inada.

At least 181 records · Page 10Linked to original sources

PubMed1990

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

Endocrine effects of hypotension induced by nicardipine, a calcium antagonist, were studied in 18 male rabbits under halothane anesthesia. They were randomly divided into two groups; nicardipine (group N; n = 10) and controls (group C; n = 8). No change was noted in plasma catecholamines in group C throughout the experiment, but plasma renin activity decreased progressively. During and after induced hypotension, in group N, plasma epinephrine was significantly higher than the control value. The highest level of plasma epinephrine was seven times of the control value during 30 minutes after induction of hypotension. Plasma norepinephrine of group N was significantly higher than the controls. The maximum increase occurred 60 minutes after induction of hypotension. Plasma renin activity of group N was significantly higher than the control value. Compared with the control value (15.1 +/- 1.8 ng.ml-1.hr-1), plasma renin activity was activated 30 and 60 minutes after induction of hypotension (55.5 +/- 6.0 ng.ml-1.hr-1, P less than 0.001, 50.3 +/- 7.1 ng.ml-1.hr-1, P less than 0.01, respectively). In conclusion, our data show that hypotension by nicardipine activates the renin-angiotensin-sympathetic system.

Animals↗

PubMed1990

[Plasma and red blood cell cyanide concentrations during hypotension induced by sodium nitroprusside or by a nitroprusside-trimetaphan mixture in rabbits].

Plasma and red blood cells cyanide concentrations during hypotension induced by sodium nitroprusside and a nitroprusside-trimetaphan mixture were studied in 29 male rabbits under halothane anesthesia. They were randomly divided into three groups; Nitroprusside (group N; n = 10), A nitroprusside-trimetaphan mixture (group M; n = 10), Controls (group C; n = 9). No changes were noted in plasma and red blood cells cyanide concentrations in group C throughout the experiment. During and after induced hypotension, in group N, plasma cyanide concentration was significantly higher than the control value. The maximum increase occurred 60min after induction of hypotension and the highest concentration of plasma cyanide was six times the control value. In contrast, in group M, plasma cyanide concentration was unchanged from the control value. However, during and after induced hypotension, red blood cells cyanide concentrations of group N and group M were significantly higher compared with the control values. Red blood cells concentrations of cyanide increased for 30 and 60 min during induced hypotension in group N (27.11 +/- 3.9 micrograms.ml-1, P less than 0.001, 46, 73 +/- 4.7 micrograms.ml-1, P less than 0.001, respectively) and in group M (0.31 +/- 0.05 micrograms.ml-1, P less than 0.05, 0.29 +/- 0.03 micrograms.ml-1, P less than 0.05, respectively). In conclusion, the data suggest that a nitroprusside-trimetaphan mixture is a safe method for hypotensive anesthesia.

Animals↗

PubMed1989

[Reparative effects of sodium alginate (Alloid G) on radiation stomatitis].

Discontinuation or alteration of the schedule of radiation therapy is often necessary in patients with tumors of the parotid gland and pharynx because of the development of stomatitis. Alloid G (Sodium alginate; AL-G) is an agent with a promotive effect on healing of inflammation of the gastric and esophageal mucosa. In this study, we orally administered the agent in irradiated mice to examine its healing effect against radiation stomatitis. ICR mice (5-week-old males) were subjected to gamma-irradiation at 17-32 Gy, and followed by oral administration with either AL-G, polyvinyl pyrrolidone (PVP), or water twice daily for 20 days. The effects of the treatments on radiation stomatitis were examined according to the survival of the animals and histological findings in the oral mucosa. After irradiation at 32 Gy, it was found that the epidermal basal layer was present in the AL-G group. In both PVP and water-treated groups, however, it was not found. The dose modification factor (DMF) of 1.12 was calculated from oral radiation death of LD50/20 and radiation dose with or without AL-G. These results suggest that AL-G probably have a pharmacologically reparative effect on radiation injury of the oral mucosa, in addition to the physical epidermal protective effect due to its viscosity such as that of PVP.

Administration, Oral↗

PubMed1989

A collagen-binding glycoprotein from bovine platelets is identical to propolypeptide of von Willebrand factor.

Several proteins from bovine platelet lysate bound to type I collagen immobilized to the beads of formyl derivatives of cellulose. Among these proteins, a protein of about 100,000 daltons was purified to homogeneity by two additional affinity chromatographies, an organomercurial-agarose and a lentil lectin-agarose. This protein consisted of a single polypeptide chain which contains carbohydrate moiety and many intrapolypeptide disulfide bridges. In addition to platelets, this protein was present in plasma and cultured endothelial cells but not in red blood cells, leukocytes, and smooth muscle cells. Furthermore, it was released from platelets upon stimulation by various agonists. The purified 100-kDa protein was labeled with 125I to quantitate its binding to fibrillar type I collagen. The protein specifically bound to fibrillar collagen with the apparent dissociation constant of 5.6 x 10(-8) M for the high affinity site and 5.5 x 10(-7) M for the low affinity site. Analyses of amino acid sequences of both intact and tryptic fragments of this protein revealed that it had strong homology to the propolypeptide of human von Willebrand factor, which is also known as von Willebrand antigen II. Various properties of this protein listed above also strongly suggest that it was indeed the propolypeptide of bovine von Willebrand factor.

Amino Acid Sequence↗

PubMed1989

Inhibition of platelet-collagen interaction by propolypeptide of von Willebrand factor.

A collagen-binding glycoprotein was isolated from human platelets using affinity chromatography of immobilized collagen. Based upon characterizations of this protein we confirmed that it was identical to the propolypeptide of von Willebrand factor (pp-vWF), which is also called von Willebrand antigen II. The characteristics we have investigated are molecular weight, existence of carbohydrate chains, and the NH2-terminal amino acid sequence. pp-vWF has strong affinity to collagen and inhibits collagen-induced aggregation of human platelets at a concentration as low as 2 micrograms/ml even in the presence of plasma. This inhibitory effect is specific for collagen-induced aggregation since it does not inhibit aggregation of platelets induced by other agonists such as ADP, arachidonic acid, platelet-activating factor, ionophore A23187, and ristocetin. As pp-vWF is quickly released from platelets upon activation by various agonists, it is possible that pp-vWF functions as a repressor for excess platelet aggregation induced by collagen and constitutes a negative feed-back mechanism. Considering the fact that mature vWF supports platelet adhesion to subendothelium, present observations suggest that the propeptide portion and the mature protein could have opposing effects on hemostasis.

Amino Acid Sequence↗

PubMed1989

Enhancement of plasminogen activator activity in cultured endothelial cells by granulocyte colony-stimulating factor.

A hitherto unknown function of granulocyte colony-stimulating factor (G-CSF) was found using cultured endothelial cells. G-CSF stimulated activity of plasminogen activator (PA) in both extracellular and intracellular milieus of endothelial cells obtained from bovine carotid and aortic artery. This effect was dependent on the concentration of G-CSF added to the culture medium and on the treatment time. The extracellular activity was enhanced approximately 5-fold at a concentration of 5,000 colony-forming unit (CFU)/ml (2.6 nM) and in about a 15-hr treatment period. Analyses by fibrin and reverse fibrin autography revealed that activity of PA was much more increased than that of PA inhibitor in endothelial cells treated with G-CSF.

Animals↗

PubMed1989

Treatment of skin and median nerve defects with peroneal neurofasciocutaneous flap.

A large neurofasciocutaneous flap that consisted of a peroneal flap and a segment of sural nerve was used in the simultaneous reconstruction of a large soft tissue and nerve defect caused by a crushing injury of the distal forearm. A 10 x 15 cm peroneal flap, including a 10 cm segment of sural nerve, was successfully transferred to an 8 x 12 cm skin defect, reconstructing a 5 cm defect of the median nerve. Two years after repair, the opponens pollicis muscle showed good contraction, although palmar abduction of the thumb remained poor. Static two-point discrimination was 20 mm on the pulp surface of both thumb and index finger and 15 mm on the middle finger.

Adult↗

PubMed1989

Continuous local intra-arterial infusion of anticoagulants for digit replantation and treatment of damaged arteries.

From May 1958 to May 1987, 428 upper extremities were replanted, with an overall survival rate of 87.4 percent. With the aim of increasing the survival rate a new method was tried. Unlike conventional continuous intravenous infusion, a Teflon catheter (28 gauge) was inserted into the proximal main artery of the anastomosed artery, and a daily dose of 80 ml comprising 240,000 U of urokinase, 40 micrograms of prostaglandin E1, 10,000 U (maximum) of heparin, and low molecular weight dextran was administered by means of continuous infusion for the 10 consecutive days, during which arterial thrombosis is likely to occur. Thirteen cases (replantations and damaged digital arteries) survived without any re-operation for arterial thrombus. There were statistically significant differences (p less than 0.025) in platelet count, fibrinogen, and AT III preoperatively and three days postoperatively. There were also statistically significant differences (p less than 0.05) in prothrombin time, partial thromboplastin time, and clotting time between pre-operative measurements and those taken four and 15 hr postoperative, but those data remained within normal range. No abnormalities were present in the arteries through which the catheter was inserted, as validated by postoperative digital subtraction angiography.

Adult↗

PubMed1989

Pedicled and "flow-through" venous flaps: clinical applications.

Recently, the pedicled venous flap and "flow-through" venous flap have been the focus of increasing attention for skin defects of the fingers and hands. For successful venous flap use, the following approaches have been suggested: (1) a pedicled venous flap with preservation of the draining veins alone; (2) a "flow-through" flap with preservation of a flow-through vein in the flap; and (3) an arterialized "flow-through" venous flap which ensures arterial blood flow into the flap. Based on findings that venous blood is helpful in flap survival, the authors made use of the first two flap types, the pedicled venous flap and the "flow-through" venous flap and attempted to establish and clarify reasonable conditions for flap survival. Venous pressure of the finger and elbow was measured and venographies of the finger and hand were also carried out. The following conditions are regarded as essential in successful venous flap procedures: (a) use of a venous flap with a rich venous network; (b) preservation of many "flow-through" veins; (c) harvesting a pedicled venous flap where the veins have afferent (reversed) venous pressure; and (d) anastomosing veins of the "flow-through" flap with recipient veins where high efferent venous pressure exists and differential pressure is observed. Clinical cases are presented and the authors attempt to explain flap failure from previously unknown causes. Conditions for flap harvesting are also discussed.

Adult↗

PubMed1989

Experimental studies of skin flaps with subcutaneous veins.

The authors have previously reported that skin flaps with subcutaneous veins nourished by arterial or venous inflow survived, despite being sited on recipient beds with poor circulation. In these previous studies, experimental models were based on axial pattern flaps of rabbit ears. However, for clinical application, there are problems in the use of axial pattern flaps with central vessels. This report classifies skin flaps with subcutaneous veins and produces experimental models that are suitable for clinical application and investigation of survival rates. Thirty-seven rabbits (74 ears) were used in this study. A 3.0-cm x 4.5-cm skin flap with only a "passing" vein (one that traveled through the tissue without major branches to that tissue) was raised at the level of the perichondrium on the dorsum of the auricular cartilage. The flaps were divided into three groups: Group A--composite flaps (n = 10); Group B--totally venous perfused flaps (n = 30); and Group C--afferent arterialized venous perfused flaps (n = 34). More than 80 percent of the flaps became necrotic in Group A. In Group B, 18 of 20 survived with partial superficial necrosis and two became more necrotic. In Group C, 18 of 21 flaps survived with superficial necrosis and three became more necrotic. Microangiographically, as concerns the "passing" veins in Groups B and C flaps, all of the flaps survived with only superficial necrosis. The skin flaps with subcutaneous veins survived as total venous perfusion flaps (TVPF) and as arterialized afferent venous perfusion flaps (AAVPF) even though the artery was not included in the flap. The experimental model is suitable for the investigation of the clinically unconventional flap.

Animals↗

PubMed1989

In vivo binding of circulating immune complexes by C3b receptors (CR1) of transfused erythrocytes.

The effects of packed erythrocyte transfusion with high CR1 activity on circulating immune complex concentrations were studied in 14 transfusion experiments involving 12 patients with immune complex related diseases. Before erythrocyte transfusion circulating immune complex concentrations ranged from 8 to 128 micrograms/ml. After transfusion (2-3 units) immune complex concentrations decreased depending on the levels of CH50 titres in the recipients. In 11 experiments, in which the patients' CH50 titres ranged from 21 to 44, immune complex concentrations decreased by 75-100% within five days. The CH50 titres were also decreased after erythrocyte transfusion but subsequently increased to initial ranges within 6-35 days. In three patients with low CH50 titres (1.0-10.0) decreases in immune complexes were not observed. Direct Coombs' tests for IgG and C3 were performed before and after erythrocyte transfusion to determine potential in vivo binding of circulating immune complexes. Thus in eight of 14 experiments, in which erythrocytes carried no IgG before packed erythrocyte transfusion, seven became Coombs' positive for IgG after the transfusion. In seven of 14 experiments, in which erythrocytes were negative for complement before transfusion, five became positive afterwards. Moreover, in 12 instances slight increases of CR1 activity of patients' erythrocytes were observed within eight days, which improved further within 35 days after erythrocyte transfusion. These studies suggest that transfusion of erythrocytes with high CR1 activity results in the removal of circulating immune complexes and that this process is dependent on complement consumption. These experiments support the hypothesis that erythrocyte-CR1 has a functional role in the removal of circulating immune complexes and may thereby inhibit the deposition of immune complexes within body tissue constituents.

Antigen-Antibody Complex↗

PubMed1989

[Histopathological and clinical studies of acute necrotizing ulcerative gingivitis and evaluation of treatment].

We report the clinical data, light and electron microscopic findings, therapy and clinical course of three cases treated for acute necrotizing ulcerative gingivitis. The following results were obtained. 1. An ulcerous lesion was observed in the gingiva of all three cases, with case I also showing a depressed lesion in the ulcerous region. 2. In all three cases, the gingival sections displayed ulceration and showed fibrin deposition and neutrophil infiltration on the surface of the ulcerous region. Congested blood vessels and neutrophil infiltration also were observed in the connective tissue beneath the ulcerous region. 3. Many microorganisms, fibrin, cell debris, and enlarged intercellular spaces of the epithelium were seen on the surface on the ulcerous region. 4. Localized treatment, mainly plaque control, was found to be effective clinically and histopathologically.

Gingivitis, Necrotizing Ulcerative↗

PubMed1989

[Comparison of effects on carbohydrate metabolism of hypotension induced by sodium nitroprusside and a nitroprusside-trimetaphan mixture in rabbits].

Effects on carbohydrate metabolism of hypotension induced by sodium nitroprusside and a nitroprusside-trimetaphan mixture were studied in 29 male rabbits under halothane anesthesia. They were randomly divided into three groups; Nitroprusside (Group N; n = 10), A Nitroprusside-Trimetaphan Mixture (Group M; n = 10), Control (Group C; n = 9). No changes were noted in blood glucose, blood lactate, blood pyruvate and lactate/pyruvate ratio in Group C throughout the experiment. During induced hypotension, blood glucose, blood lactate, blood pyruvate and L/P ratio of group N were significantly higher than the control value. On the other hand, in group M, blood glucose and blood pyruvate tended to increase slightly but not significantly. In contrast, in group M, L/P ratio remained unchanged. The results suggest that sodium nitroprusside tended to cause tissue hypoxia more markedly than a nitroprusside-trimetaphan mixture. The mechanism may be that a mixture of nitroprusside and trimetaphan maintained the carbohydrate metabolism (including gluconeogenesis, glucogenolysis) during induced hypotension. In conclusion, our results suggest that a nitroprusside-trimetaphan mixture is a safe method for hypotensive anesthesia.

Animals↗

PubMed1989

Esterification of chiral secondary alcohols with fatty acid in organic solvents by polyethylene glycol-modified lipase.

Lipase from Pseudomonas fragi 22.39B was modified with polyethylene glycol. The modified lipase (PEG-lipase) was soluble and active in organic solvents such as benzene and 1,1,1-trichloroethane. PEG-lipase catalyzed esterification of chiral secondary alcohols with fatty acids in benzene and exhibited preference for R isomers over S isomers. Km and Vmax values for each isomer of various alcohols were obtained by kinetic study of the esterification in benzene. PEG-lipase-catalyzed esterification leads to optical resolution of a racemic alcohol.

Alcohols↗

PubMed1989

[Comparison of endocrine effects of hypotension induced by sodium nitroprusside, trimetaphan camsylate and a nitroprusside-trimetaphan mixture in rabbits].

Endocrine effects of hypotension induced by nitroprusside, trimetaphan and a nitroprusside-trimetaphan mixture were studied in 34 male rabbits under halothane anesthesia. They were randomly divided into four groups; nitroprusside (group N; n = 8), trimetaphan (group T; n = 10), a nitroprusside-trimetaphan mixture (group M; n = 8) and controls (group C; n = 8). No change was noted in plasma catecholamines measured in group C throughout the experiment, but plasma renin activity decreased progressively. During induced hypotension, plasma catecholamines and plasma renin activity of group N were significantly higher than the control value. In contrast, in group T plasma epinephrine decreased significantly. On the other hand, in group M, plasma renin activity showed a slight but not significant increase, while plasma catecholamines remained unchanged. This may have occurred since a mixture of nitroprusside and trimetaphan produced the dissociation of renin-angiotensin-sympathoadrenal loop. In conclusion, these results suggest that a nitroprusside-trimetaphan mixture is a useful method for hypotensive anesthesia by inhibiting the excessive activation of renin-angiotensin-sympathetic system.

Animals↗

PubMed1989

[The clinical application of ultra-low field (0.02 T) MRI for the diagnosis of lung tumors].

Seventy-one patients with lung tumors were studied by thoracic Ultra-low field MRI (L-MRI) and the efficacy of L-MRI is evaluated as compared with the dynamic CT scan. In staging of lung cancer, L-MRI is not useful because of its poor spatial resolution. Both T1 (Inversion recovery) and T2 (long SE) weighted images can differentiate secondary atelectasis from central tumors in 15 out of 18 (78%). This sensitivity is almost equal as that of dynamic CT. IR images with short inversion time (STIR) are particularly useful for their differentiation.

Adult↗

PubMed1988

Subunit B of factor XIII is present in bovine platelets.

Distribution of B subunit of coagulation factor XIII(FXIII B) in bovine platelets was determined. Intracellular location of FXIII B in platelets was confirmed by fluorescent antibody technique. Positive staining of FXIII B was observed with Triton-permeabilized platelets but not with non-permeabilized platelets. Immunoblots of plasma and platelet lysate revealed that the antibody was specific for FXIII B and this antigen existed in the supernatant of sonication-solubilized platelets. The amount of FXIII B in platelets was determined to be 17.3 +/- 6.7 ng/10(8) platelets by radioimmunoassay. This is the first visual and quantitative demonstration of intracellular FXIII B.

Animals↗

PubMed1988

Plasma albumin is essential for collagen-induced platelet aggregation.

We found that platelets must have albumin on the surface to respond to collagen and aggregate. Albumin, however, was not absolutely necessary for ADP-, platelet activating factor-, serotonin- or thrombin-induced aggregation, while fibrinogen was required for ADP- or serotonin-induced aggregation. Immunofluorescent microscopy revealed that albumin was retained on gel-filtrated platelets but not on washed platelets. Albumin was not required for platelet adhesion to immobilized collagen. Without albumin thromboxane formation upon collagen-stimulation was diminished. These data suggest that albumin is essential in some step(s) that results in production of thromboxane A2.

Animals↗