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Biomedical subjects

T Miyauchi

Publications and source records attributed to T Miyauchi.

At least 181 records · Page 10Linked to original sources
PubMed1992

Endothelin-1 mediates regional blood flow during and after pulmonary operations.

To investigate the role of endothelin-1, a potent vasoconstrictor peptide produced by vascular endothelial cells, in the physiologic response to surgical stress, we measured plasma endothelin-1 concentrations by a sandwich-enzyme immunoassay in patients with lung cancer undergoing pulmonary operations (n = 12). In the first group (n = 6), we measured plasma endothelin-1 concentrations at multiple sampling sites (median cubital vein, pulmonary artery, and left atrium). Plasma endothelin-1 levels were significantly increased at all sampling sites at the end of the operation. Although there was no difference between the increased plasma levels of endothelin-1 in the pulmonary artery and in the left atrium, the increased level in the median cubital vein (peripheral venous blood) was significantly higher than that in the pulmonary artery (mixed venous blood). This result suggests that the production of endothelin-1 might differ between various organs under surgical stress. In the second group (n = 6), we measured plasma endothelin-1 concentrations both in the median cubital vein and in the ipsilateral radial artery, and also measured cardiac output and forearm blood flow. The increase in endothelin-1 levels in the median cubital vein was significantly higher than that in the radial artery after the operation. The endothelin-1 output from the forearm, calculated by the forearm blood flow and the arteriovenous difference of endothelin-1 concentrations, significantly increased after the operation. Although the cardiac output significantly increased after the operation, the forearm blood flow significantly decreased. The present findings provide a novel hypothesis that the preferential release of endothelin-1 from the peripheral vasculature of the forearm may partly contribute to a compensatory response to surgical stress, for example, the reduction of local blood flow in nonvital organs so as to increase the blood flow in vital organs.

Adult↗
PubMed1992

Significance of plasma endothelin-1 levels in patients with systemic sclerosis.

Endothelin-1 (ET-1) is a novel potent vasoconstrictor peptide discovered in the supernatant fraction of cultured endothelial cells. We measured plasma levels of ET-1 using a sensitive sandwich enzyme immunoassay. Plasma concentrations of ET-1 in 31 patients with systemic sclerosis (SSc) (1.90 +/- 0.47 pg/ml) were higher than those (1.31 +/- 0.10 pg/ml) in 25 age and sex matched healthy subjects. Patients with SSc with diffuse scleroderma had higher levels of ET-1 compared with those with limited scleroderma. Plasma ET-1 levels correlated inversely with carbon monoxide diffusing capacity (DLco). Measurement of plasma ET-1 levels may be useful as a predictor of prognosis of SSc.

Adult↗
PubMed1991

Endothelin-1 and endothelin-3 play different roles in acute and chronic alterations of blood pressure in patients with chronic hemodialysis.

We measured plasma concentrations of endothelin-1 (ET-1), ET-3 and big ET-1 by sandwich-enzyme immunoassays in patients (Pt) with chronic hemodialysis (HD) (Pt-HD, n = 23) and age-matched normal subjects (NS, n = 17). In Pt-HD, plasma levels (before HD) of ET-1, ET-3 and big ET-1 were significantly higher than those in NS. Reverse-phase HPLC analysis indicated that plasma concentrations of ET-1, ET-3 and big ET-1 in both Pt-HD and NS can be precisely measured by these sandwich-enzyme immunoassays. In Pt-HD, although the plasma ET-3 or big ET-1 levels did not significantly correlate with blood pressure (BP), plasma ET-1 levels significantly (p less than 0.01) correlated with both the levels of systolic (r = 0.63) and diastolic (r = 0.54) BP. After 4-hour HD, the plasma level of ET-3, but not ET-1 or big ET-1, was significantly elevated and BP was significantly lowered. The present findings indicate that ET-1 and ET-3 play different roles in acute and chronic alterations of BP in Pt-HD.

Antibodies, Monoclonal↗
PubMed1991

Purification and characterization of a rat liver membrane tyrosine-protein kinase, the possible protooncogene c-yes product, p60c-yes.

A tyrosine-protein kinase was purified more than 270-fold from the rat liver plasma membrane fraction by successive column chromatographies on Sephacryl S-300, wheat germ agglutinin-agarose, casein-Sepharose, and hydroxylapatite, followed by isoelectrofocusing electrophoresis. The enzyme with pI of 6.2 was a 60-kDa single polypeptide which represented 42% of total protein. The enzyme reacted quantitatively with a monoclonal antibody to the amino-terminal sequence (Cys-3 to Ser-66) specific to the human c-yes protein, but not with antibodies to the specific amino-terminal sequences of the c-src, fyn, and lck proteins. The purified enzyme contained almost no phosphotyrosine residue but was autophosphorylated with Mg.ATP exclusively at tyrosine residues with concomitant increase in the kinase activity. The rates of autophosphorylation of the enzyme and phosphorylation of tyrosine-glutamate (1:4) copolymers, catalyzed by the enzyme were proportional to the square of enzyme concentration, suggesting that p60c-yes undergoes autophosphorylation through intermolecular catalysis, resulting in stimulation of the enzyme activity. Although the enzyme reaction showed an essential requirement for Mg2+ or Mn2+ with optimal concentrations of 20 and 3 mM, respectively, autophosphorylation significantly activated the enzyme only in the presence of Mg2+. Autophosphorylation of the enzyme reduced the Km for tyrosine-glutamate copolymers and tubulin, but not for ATP, and increased the Vmax of copolymer and tubulin phosphorylation.

Animals↗
PubMed1991

The basigin group of the immunoglobulin superfamily: complete conservation of a segment in and around transmembrane domains of human and mouse basigin and chicken HT7 antigen.

Basigin belongs to the immunoglobulin superfamily and may be related to the primordial form of the superfamily. Human basigin cDNA was isolated and sequenced, and the predicted protein structure was compared with that of mouse basigin and two related molecules, embigin and the chicken blood-brain barrier antigen HT7. Between human and mouse basigin, 58% of the amino acids were identical and 80% of the changes were conservative. A stretch of 29 amino acid residues in the transmembrane and cytoplasmic domains was conserved not only in human and mouse basigin but also in HT7 antigen. The conserved structure may be required for interaction with a membranous protein. In addition, the relationship of basigin with other members of the immunoglobulin superfamily has been evaluated.

Amino Acid Sequence↗
PubMed1991

Effects of endothelin-1 on coronary microcirculation in isolated beating hearts of rats.

An intravital fluorescence videomicroscope system was used to investigate the pharmacological effects of endothelin-1 (ET-1) on the coronary microcirculation in isolated beating hearts of rats. The heart was perfused by retrograde aortic steady flow with an oxygenated Krebs-Ringer solution containing FITC-dextran. Cumulative injections of ET-1 (1-30 pmol) elicited a dose-dependent increase in perfusion pressure from 52 +/- 15 mm Hg (mean +/- SEM; n = 6) before the ET-1 injection to 104 +/- 23 mm Hg at the ET-1 dose of 30 pmol. A dose-dependent narrowing of microvessels was also observed on a monitor screen. This diffuse vasoconstriction was especially prominent in small arterioles; the maximum vasoconstriction of the smaller arterioles was significantly higher than that of the larger arterioles. These findings suggest that ET-1 may have an important role in governing the coronary resistance and regulating the capillary flow in myocardium.

Animals↗
PubMed1991

Plasma concentrations of endothelin-1 and endothelin-3 are altered differently in various pathophysiological conditions in humans.

Several studies have indicated that endothelin-1 (ET-1) and endothelin-3 (ET-3) are produced by different cells. Although ET-1 is produced by vascular endothelial cells, these cells do not produce ET-3. In the present study, we measured plasma concentrations of both ET-1 and ET-3 by sandwich-enzyme immunoassays which we developed recently in patients on chronic hemodialysis, age-matched normal subjects, patients with acute myocardial infarction, patients undergoing surgery, and healthy subjects before and after strenuous endurance exercise. Plasma levels of ET-1 and ET-3 were demonstrated to be altered differently in the above conditions in humans. Although the exact origin of circulating endothelins has yet to be elucidated, the different alterations of plasma levels suggest that both ET-1 and ET-3 may play different roles in physiological and/or pathophysiological responses to various conditions in humans.

Adult↗
PubMed1991

Increased plasma concentrations of endothelin-1 during and after pulmonary surgery.

We studied the involvement of endothelin-1 (ET-1) in the physiological response to surgical stress. Plasma concentrations of ET-1 were measured by a sandwich-type enzyme immunoassay. The blood samples were collected from the pulmonary artery (PA), the left atrium (LA), and the median cubital vein (MCV) in four patients who had undergone pulmonary lobectomy. The samples were collected before, during, and after surgery. Plasma ET-1 concentrations increased in the blood from all sampling sites. The highest concentration of plasma ET-1 was observed at 6 h after surgery in MCV (3.97 +/- 1.47 pg/ml, mean +/- SD) and at the end of surgery in PA (1.79 +/- 0.48 pg/ml) and in LA (1.93 +/- 0.43 pg/ml). These values returned to the baseline value within 72 h after surgery [1.21 +/- 0.19 (MCV), 1.00 +/- 0.18 (PA)]. Although the lung has a large capacity to remove ET-1 from the circulating blood, ET-1 concentrations measured in plasma samples obtained from the LA were not different from those obtained from the PA. This may suggest that the lungs have the ability to absorb and release ET-1 simultaneously during pulmonary surgery. The increase of ET-1 in MCV was greater than that in PA or in LA. This suggests the possibility of ET-1 release from the forearm.

Endothelins↗
PubMed1991

Sandwich-enzyme immunoassays for endothelin family peptides.

Sandwich-enzyme immunoassays (sandwich-EIAs) for endothelin-1 (ET-1), endothelin-3 (ET-3), big ET-1, big endothelin-2 (big ET-2), and big endothelin-3 (big ET-3) have been established using two antibodies directed against the N-terminal and C-terminal portions of each ET and big ET. These sandwich-EIAs are sensitive enough to detect 0.1-0.4 pg/well of each ET or big ET with cross-reactivity of less than 1% with other ETs and big ETs (except in the case of the EIA for ET-1, which detects immunoreactivity of ET-2 as well as ET-1). Plasma levels of immunoreactive (ir-) ET-1, big ET-1, and ET-3 in normal humans were approximately 2.0, 5.1, and 0.9 pg/ml, respectively, when corrected for recovery efficiency. In reverse-phase high-performance liquid chromatography (HPLC) analysis, immunoreactivities detected by these sandwich-EIAs were eluted at the positions of authentic ET-1, big ET-1, and ET-3, indicating that plasma levels of ET-1, big ET-1, and ET-3 were precisely measured by our methods. Levels of ir-big ET-2 and ir-big ET-3 were also detected in normal human plasma; however, further studies are needed to determine their precise values. The establishment of reliable sandwich-EIAs and the measurement of specific ETs and big ETs in normal human plasma will contribute to clarifying the biological and clinical significance of ET family peptides.

Adult↗
PubMed1991

Increased plasma level of endothelin-1 and coronary spasm induction in patients with vasospastic angina pectoris.

To elucidate the pathogenic contribution of a potent vasoconstrictor, endothelin-1, to coronary artery spasm, we provoked spasm with intracoronary administration of acetylcholine or ergonovine and performed sensitive immunoassays of plasma levels of endothelin-1 and atrial natriuretic factor (ANF) in the peripheral vein and coronary sinus of patients with a tentative diagnosis of vasospastic angina (VSA, n = 19). The validity of coronary sinus blood sampling was verified by simultaneous measurement of the ANF level. The plasma endothelin-1 levels in venous and coronary sinus blood of the spasm-provoked patients (n = 12) were 1.71-fold and 2.16-fold higher, respectively, than those of nonprovoked cases (n = 5, p less than 0.01). During left coronary spasm, the endothelin-1 level in coronary sinus transiently decreased from 2.27 +/- 0.14 to 1.76 +/- 0.14 pg/ml (p less than 0.01) and returned to the control level (1.98 +/- 0.20 pg/ml) after the spasm resolved, whereas the change was equivocal during right coronary spasm. In contrast, the patients in whom spasm was not provoked showed no changes and maintained low endothelin-1 levels both before and after the maximal provocation (0.90 +/- 0.13 versus 0.90 +/- 0.13 pg/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1991

Basigin, a new member of the immunoglobulin superfamily: genes in different mammalian species, glycosylation changes in the molecule from adult organs and possible variation in the N-terminal sequences.

Basigin is a new member of the immunoglobulin superfamily with homology to both the immunoglobulin V domain and major histocompatibility complex class II antigen beta-chain. Southern blot analysis indicated that the basigin gene was present as a single copy or as a few copies per mouse genome. Although a homologous gene was detected in the hamster and human, Southern and Northern blotting experiments indicated considerable species specificity in the basigin structure. The molecular weight of N-glycanase-treated basigin from embryonal carcinoma cells was about 32,000 and was close to the value of basigin polypeptide inferred from the cDNA sequence; the result confirmed the open reading frame of basigin. Upon Western blotting, large amounts of basigin were detected in the mouse kidney as a glycoprotein bound to Ricinus communis agglutinin (RCA)-I and as a glycoprotein bound to concanavalin A; the molecular weight of the former was 38,000-43,000, and of the latter was 30,000. Basigin of the molecular weight of 48,000 was detected in RCA-I-binding glycoproteins of the liver, small intestine and spleen. Thus, different forms of basigin can be produced by different modes of glycosylation. Another source of heterogeneity of basigin may be differences in N-terminal sequences, since cDNA clones with different 5' coding sequences were identified.

Amino Acid Sequence↗
PubMed1991

[Clinical study of bilateral metachronous testicular tumors with different histological findings].

Seventy-seven patients with primary malignant testicular tumors were treated in our hospital. Twenty-five of them were given antineoplastic agents containing cis diamine dichloro platinum (CDDP). In three long-term survivors, new malignant testicular tumors developed meta-chronously and had different histological findings from those of the initial tumors. Case 1. A 28-year-old patient with a yolk sac tumor of the left testicle, stage IIO, developed metastasis to the supraclavicular lymph nodes five years after radiation. Chemotherapy containing of VP-16 (837 mg), CDDP (1050 mg), vincristine (32 mg), bleomycin (480 mg), and actinomycin-D (16 mg) achieved complete remission. Four years 11 months later a seminoma of the contralateral testicle, stage I, was disclosed and he died of cancer 11 years and four months after the onset of the initial disease. Case 2. A 30-year-old patient with testicular teratoma, stage IIIA, on the right side gained complete remission after a CDDP containing chemotherapy. One year and four months after the beginning of the CDDP use (1,300 mg totally as CDDP) a seminoma on the contralateral side, stage I, was detected. He died of cancer eight years and two months after his initial tumor was detected. Case 3. A 37-year-old patient with combined tumor of seminoma and yolk sac tumor of the right testicle, stage IIIO, was free from disease for six years and five months under chemotherapy. At this point a seminoma, stage I, of the contralateral testicle was newly found and treated by radiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[A case of cytomegalovirus infection that caused gastrointestinal perforation after surgery for cancer of the bladder].

A 78-year-old man visited our department for macroscopic hematuria in June, 1989. On the basis of the diagnosis of tumor of the bladder and right afunctional kidney, total right nephro-uretero-cystectomy and skin grafting of the left ureter were performed on August 2. The patient continued to have fever of unknown origin postoperatively. Repeat laparotomy, which was performed for rectal fistula on August 25, revealed that the abdominal wall, colon, small intestine and mesenterium adhered to one another, producing a mass and that two sites in the rectum were perforated. A part of the small intestine was excised, the perforated sites were sutured, and an artificial anus was created at the transverse colon. Since the patient had intermittent fever and continued to complain of abdominal pain after creation of the artificial anus, nosotropic therapy was continued. However, the patient died from cardiac insufficiency on October 10. Erosion and ulcer were histologically observed over a wide range in the excised small intestine. In addition there was a defect in one area of the small intestine, penetrating the tunca muscularis propria, in which many cytomegalovirus (CMV) inclusion bodies were observed. CMV inclusion bodies were also detected in the bladder with re-examination of specimens from the excised bladder. From these findings, it appears that endogenetic CMV may have been reactivated in the present case.

Aged↗
PubMed1991

[Contributory changes in variables of coagulation and fibrinolysis to the patency of coronary arteries in patients with acute myocardial infarction].

Plasma levels of fibrinopeptide A (FPA), D-dimer and tissue-plasminogen activator antigen (t-PA-Ag) were measured serially in 38 patients with acute myocardial infarction undergone emergency coronary angiography and/or PTCR (percutaneous transluminal coronary recanalization). A special attention has been focussed in the possible correlation of the variables of coagulation and fibrinolysis with the degree of patency of infarct-related coronary arteries (IRAs). Before PTCR, 26 patients with completely occluded IRAs had significantly higher plasma levels of FPA when compared with those of 12 patients with incompletely occluded IRAs (33.8 +/- 2.4 vs 11.0 +/- 1.3 ng/ml, mean +/- SD, p less than 0.05, respectively). Successful recanalization were resulted in 19 of 26 patients with completely occluded IRAs. Though plasma D-dimer levels significantly increased after PTCR both in patients with or without successful reperfusion, there were neither differences in the two groups before nor after PTCR (154.8 +/- 1.9 to 257.0 +/- 3.0 vs 131.6 +/- 4.8 to 254.9 +/- 4.1 ng/ml, mean +/- SD, respectively). Coronary angiography in 30 patients, performed about a month after the onset of acute myocardial infarction, revealed good patency (the stenosis was less than 90% evaluated according to the American Heart Association Committee Report in 1975) of IRAs in 17 patients and poor patency (the stenosis was 99% or 100%) of IRAs in 13 patients. The former patients had significantly higher plasma levels of t-PA-Ag after 24 hours from the onset than those of the latter patients (26.6 +/- 10.7 vs 17.4 +/- 4.2 ng/ml, mean +/- SD, p less than 0.05, respectively). These findings suggest that the increase in thrombin activity affects unfavorably the patency of IRAs in the evolving of myocardial infarction, and that the responsiveness of endothelial cells to acute phase stimuli such as thrombin and heparin affects favorably the patency of IRAs in the chronic phase; Elevated plasma levels of D-dimer do not necessarily indicate coronary thrombolysis.

Aged↗
PubMed1991

[Carcinoma of the gastric remnant fed by the accessory left gastric artery--a case report].

A 65-year-old female, who had undergone partial gastrectomy with Billroth II reconstruction for duodenal ulcer 22 years ago, visited our hospital with a complaint of anorexia. Roentgenogram and endoscopic examination revealed a protruding lesion on the posterior wall of the gastric remnant. An endoscopic biopsy specimen was histologically regarded as carcinoma. Proper hepatic arteriography revealed an accessory left gastric artery arising from the left hepatic artery, which was a main feeder to the tumor. Total gastrectomy with lymph node dissection and splenectomy were performed. Histology of the tumor was poorly differentiated adenocarcinoma located in the submucosal layer. To our knowledge, there is no report about the carcinoma of the gastric remnant fed by the accessory left gastric artery.

Adenocarcinoma↗
PubMed1991

[Lung ventilation imaging with TECHNEGAS: clinical study of lung deposition and ventilation/perfusion].

In order to optimize inhalation method for lung ventilation imaging with Tc-99m-gas (TECHNEGAS), relation between lung deposition of TECHNEGAS and inhalation method was evaluated. Submaximal inhalation with breath-holding (BH), continuous submaximal inhalation (C) and tidal inhalation (TV) were compared in 35 patients (36 studies) with various lung diseases. Mean lung deposition of TECHNEGAS was 6.6-7.4%/LD in BH group and was significantly higher than other groups of inhalation method (p less than 0.05-0.001). Lung deposition increased according to the times of inhalation in C group. TV group resulted in the lowest lung deposition which was same as 5 times of inhalation in C group. Lung/filter ratio (L/F) was highest in BH group. Image quality of TECHNEGAS was significantly better in BH group. Hot spot in central airway was seen in 15% of patients. All of them was in TV or C groups. In order to improve lung deposition and image quality of the TECHNEGAS, sufficient breath-holding was important. L/F seemed to be the index of effective inhalation of the TECHNEGAS. TV was suitable for poorly cooperative or dyspneic patients. TECHNEGAS was useful for evaluation of lung ventilation to provide good quality image with safety and simplicity.

Administration, Inhalation↗