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Biomedical subjects

K Kagawa

Publications and source records attributed to K Kagawa.

At least 109 records · Page 6Linked to original sources
PubMed1993

Acute effects of conventional oral dose of disopyramide on left atrial and ventricular functions.

Disopyramide, an antiarrhythmic drug, is known to impair cardiac function, but acute cardiac effects of conventional oral dose of disopyramide are not well known. To examine the extent of acute cardiac effects of daily oral dose of disopyramide, we gave 150 mg of disopyramide to thirteen patients with normal or impaired cardiac function, and observed cardiac function on an hourly basis for 3 hours after baseline period. The serum level of disopyramide reached a therapeutic level (2.0-5.0 micrograms/ml) mostly 1 hour after administration. Doppler-echocardiographically determined left ventricular ejection fraction, and the ratio of the peak early filling velocity to the peak atrial filling velocity in left ventricular inflow velocity remained unchanged throughout the experimental period. Other hemodynamic variables, such as blood pressure and heart rate remained unchanged. We conclude that daily oral dose of disopyramide appears to have no significant effects on cardiac function after administration. Disopyramide seems to be safe and may not be necessarily withheld from patients who need it, when hemodynamic variables are to be measured.

Adult↗
PubMed1993

Defenestration of the sinusoidal endothelial cell in a rat model of cirrhosis.

We characterized the structural and immunohistological changes of sinusoidal endothelial cells that occur during cirrhosis in rats made cirrhotic with thioacetamide. Thioacetamide (200 mg/kg body wt) was injected intraperitoneally three times a week into male Wistar rats. Two, 4, 6 and 12 wk later, rat livers were observed under transmission and scanning electron microscopy and regular microscopy and immunostained with laminin and von Willebrand factor (factor VIII-related antigen) antibodies. The diameters and numbers of sinusoidal endothelial fenestrations did not change significantly after 2 wk in the thioacetamide-treated rats; however, they decreased within 4 wk after thioacetamide treatment. A basement membranelike structure in Disse's space was noted 6 wk after thioacetamide treatment. Laminin was detected in Disse's space after 4 wk. In vitro, in cultured sinusoidal endothelial cells, the diameter of sinusoidal endothelial fenestrations was significantly lower at 6 wk in thioacetamide-treated rats. von Willebrand factor was detected in the cytoplasm as granular fluorescence after 6 wk of thioacetamide treatment. These results suggest that as fibrosis develops in cirrhosis, the structural and immunohistochemical characteristics of sinusoidal endothelial cells change.

Animals↗
PubMed1992

Age-related increase in systolic fraction of pulmonary vein flow velocity-time integral from transesophageal Doppler echocardiography in subjects without cardiac disease.

The pulmonary vein flow velocity-time profile would be equivalent to the pulmonary vein flow volume-time profile, provided that the cross-sectional area of the pulmonary vein remains unchanged during 1 cardiac cycle. The systolic fraction of the pulmonary vein flow velocity-time integral, a ratio of velocity-time integral of the S wave to the sum of velocity-time integrals of the S and D waves, represents the ratio of left atrial storage volume to left ventricular stroke volume. This systolic fraction may help early filling of the left ventricle through an appropriate storage of blood and generation of driving pressure in the left atrium. Because early filling of the left ventricle is progressively impaired with age, it was hypothesized that this systolic fraction is increased with age. Forty-four noncardiac surgical patients (age range 17 to 70 years) who underwent transesophageal Doppler echocardiography under general anesthesia were studied, and left upper pulmonary vein flow and mitral inflow velocities were recorded. The ratio of peak velocity of the E wave to that of the A wave of mitral inflow velocity-time profile (y) decreased with age (y = -0.0245 x age + 2.41; r = -0.672, p < 0.01). Systolic fraction (y) increased with age (y = 0.00373 x age + 0.514; r = 0.656, p < 0.01). The age-related increase in the systolic fraction of pulmonary vein flow velocity-time integral may account for the compensation for impaired early filling of the left ventricle in elderly patients.

Adolescent↗
PubMed1992

Presence of a Vicia unijuga lectin-binding (Vgu) glycoprotein with Thomsen-Friedenreich (T) activity and Vgu glycoproteins in human primary hepatocellular carcinoma.

1. Twenty perchloric acid-soluble glycoprotein fractions (PASFs) were separated from carcinomatous and non-carcinomatous regions of the livers of 5 patients with primary hepatocellular carcinoma (HCC) and 5 patients with a complication of HCC and hepatocirrhosis (HC). 2. In autoradiography using 125I-labelled Vicia unijuga lectin (VUA) and 125I-labelled Arachis hypogaea anti-T lectin as probes, 10 PASFs from carcinomatous regions of the livers of 10 patients gave 1 Vgu glycoprotein with T activity and/or 1-4 Vgu glycoproteins, respectively, and among 10 PASFs from non-carcinomatous regions of the livers of 10 patients, 7 PASFs gave no glycoproteins, respectively. 3. These results show that a Vgu glycoprotein with T activity and Vgu glycoproteins occur in HCC and in a complication of HCC and HC as oncofetal antigens.

Antibodies↗
PubMed1992

Functional heterogeneity of rat liver macrophages: interleukin-1 secretion and Ia antigen expression in contrast with phagocytic activity.

To clarify whether immunological heterogeneity exists among liver macrophages and whether this possible heterogeneity corresponds to varying degrees of phagocytic activity, we fractionated liver macrophages according to size via centrifugal elutriation and studied their ability to ingest latex beads, to express Ia antigen and to secrete interleukin-1 (IL-1) in vitro. Larger liver macrophages were found to be more active in ingesting latex beads than smaller ones (p less than 0.01), while smaller liver macrophages were more active in Ia antigen expression and evidenced greater fluorescence at cytofluorometric examination. In addition, smaller liver macrophages elaborated more IL-1 than the larger liver macrophages (p less than 0.05). These results indicate that liver macrophage heterogeneity is seen in at least two important macrophage functions: phagocytosis of large molecules, which provides an important scavenger function, and Ia antigen expression and IL-1 secretion, important components of the immune response.

Animals↗
PubMed1992

Platelet aggregation inhibitors and inotropic constituents in Pyrolae herba.

The chloroform-soluble and n-butyl alcohol-soluble fractions of water extract of Pyrolae Herba inhibited platelet aggregation induced by arachidonic acid and showed a positive inotropic effect. A new naphthoquinone and a new tetralone derivative and known chimaphilin, acetovanillon, and toluhydroquinone were isolated as active constituents. Three new tetralone derivatives were also obtained from an active fraction. The structures of the new compounds were elucidated.

Animals↗
PubMed1992

Platelet aggregation inhibitors from Populus sieboldii Miquel.

The water extract of Populus sieboldii Miquel (Salicaceae) inhibited arachidonic acid-induced platelet aggregation. Pyrocatechol and salicyl alcohol were isolated as active constituents. Pyrocatechol showed an inhibitory effect on platelet aggregation induced by arachidonic acid with IC100 value of 4 microM, which was 25 times more potent than aspirin.

Drugs, Chinese Herbal↗
PubMed1992

Elevated interleukin-6 and gamma-globulin during interferon therapy of hepatitis B.

A 49-yr-old man with chronic hepatitis B manifested hypergammaglobulinemia, lymphadenopathy, and a high serum interleukin-6 level following treatment with recombinant human alpha-interferon. One month later, when the patient was treated with natural beta-interferon, serum levels of interleukin-6 and gamma-globulin increased again. The serum gamma-globulin decreased to the pretreatment level after discontinuation of interferon therapy. The serum alanine aminotransferase level remained normal for 6 months. In this case, hypergammaglobulinemia and lymphadenopathy, as well as the elevated serum interleukin-6 level, were considered to be signs of highly enhanced humoral immunity related to alpha- and beta-interferon therapy.

Alanine Transaminase↗
PubMed1992

[Concomitant cardiac and pulmonary operation in a case of lung tumor with unstable angina].

The patient, a 55-year-old male, suffered from malignant lung tumor with complaints of bloody sputum and anterior chest pain. Angina pectoris was detected during neoadjuvant chemotherapy, because of total obstruction at #7 and 99% stenosis at #12, as disclosed by CAG. As he complained frequently anginal chest pain in the course of time, the concomitant cardiac and pulmonary operation was decided via median sternotomy and fourth intercostal thoracotomy. The operating procedure was as follows: 1) mediastinal lymph nodes dissection before extracorporeal circulation, 2) aorto-coronary bypass (#8, #12), 3) final left lower lobectomy. He was histopathologically diagnosed as a rare case of endobronchial type of leiomyosarcoma. He has achieved a remarkable recovery, without tumor recurrence or angina pectoris for ten months postoperatively, and has been allowed to resume a normal life.

Angina, Unstable↗
PubMed1991

A case report of hepatocellular carcinoma within adenomatous hyperplasia: is adenomatous hyperplasia a precancerous lesion or not?

It is controversial whether adenomatous hyperplasia (AH) of the liver progresses to hepatocellular carcinoma. We experienced two hepatic lesions in a patient (73-yr-old male) with cirrhotic liver. One was diagnosed as HCC and the other was AH including a small HCC histologically. To investigate cell kinetics and the ploidy pattern of these lesions, Feulgen DNA-cytofluorometry analysis was performed. The result of this analysis suggested that AH developed into extremely well-differentiated HCC composed of mononuclear diploid cells at first and then was further transformed into clear cell type HCC composed of mononuclear tetraploid cells. The development of human HCC, at least in cirrhotic liver, may therefore be a multi-step process.

Aged↗
PubMed1991

Effects of amiloride and an analogue on ventricular arrhythmias, contracture and cellular injury during reperfusion in isolated and perfused guinea pig heart.

The present study was designed to examine whether activation of Na+/H+ exchange and subsequent massive Ca2+ influx via Na+/Ca2+ exchange are involved in the pathogenesis of myocardial reperfusion injury. We tested the effects of 1 mM amiloride, which is known to inhibit both Na+/H+ and Na+/Ca2+ exchange, and 3 microM 5-(N-ethyl-N-isopropyl) amiloride (EIPA), which is known to act as a specific inhibitor against Na+/H+ exchange, on the incidence of ventricular arrhythmias, isovolumic left ventricular function and creatine kinase (CK) release during reperfusion after 15 or 30 min of global ischemia in the isolated and perfused guinea pig heart. Treatment of a normally perfused heart with amiloride decreased heart rate significantly and tended to increase coronary flow and left ventricular developed pressure (LVDP), whereas treatment with EIPA decreased all of these 3 measurements significantly. Treatment with amiloride or EIPA for 15 min before ischemia, and during reperfusion after 15 min of ischemia, under electrical pacing at 240 rpm to eliminate a negative chronotropic effect abolished ventricular tachycardia (VT) and ventricular fibrillation (VF) during reperfusion associated with highly significant inhibition of increases in left ventricular end-diastolic pressure (LVEDP) and CK release. Amiloride or EIPA pretreatment also inhibited the incidence of VF and increases in LVEDP and CK release significantly during reperfusion after 30 min of ischemia. However, amiloride was more effective in preventing these events than EIPA. The treatment with amiloride or EIPA only during reperfusion after 15 or 30 min of ischemia also decreased the incidence of VF and inhibited the increases in LVEDP and CK release significantly, though less effectively than the pretreatment modality. These results suggest that EIPA prevents ventricular arrhythmias, contracture and myocardial cellular injury during reperfusion after 15 min of ischemia by inhibiting Na+/H+ exchange, while amiloride exerts more powerful protection against these events than EIPA during reperfusion after 30 min of ischemia by inhibiting both Na+/H+ and Na+/Ca2+ exchange.

Amiloride↗
PubMed1991

[Evaluation of intraoperative transesophageal echocardiography].

With the development of medical ultrasonics, anesthesiologists have recognized the usefulness of transesophageal echocardiography as an intraoperative monitoring. Intraoperative transesophageal echocardiography is now used to monitor left ventricular function and to confirm the result of surgical correction immediately after cardiac operation. In this study, we evaluated the detectability of air embolism and the effect of hemodynamic changes on physiological mitral regurgitant flow by transesophageal Doppler echocardiography (TEDE). TEDE was more sensitive than precordial Doppler ultrasound in detecting intracardiac air. TEDE could detect air inflow to the right atrium earlier than alterations in pulmonary hemodynamics. The monitoring of intracardiac air by TEDE minimized the complication by air embolism. Regarding physiological mitral regurgitation, the degree of regurgitation increased with the elevation of BP in 70% of patients. An increase in afterload seemed to cause accidental volume loading on the left heart resulting in physiological mitral regurgitation. Intraoperative monitoring of regurgitant flow by TEDE was useful for the anesthesiologist as a guide of hemodynamic management. Transesophageal echocardiography is a useful intraoperative monitoring method regardless of its several disadvantages. With further improvement of mechanical device, transesophageal echocardiography will be more often and safely performed in operating room.

Echocardiography, Doppler↗
PubMed1990

Calcium-associated cytoprotective effect of taurine on the calcium and oxygen paradoxes in isolated rat hepatocytes.

Our study was designed to determine the calcium and oxygen paradoxes in isolated rat hepatocytes, and to evaluate the cytoprotective effects of taurine on hepatocytes during oxygenation, hypoxia, and on these paradoxes. The calcium and oxygen paradoxes were clearly revealed in isolated rat hepatocytes. As the formation of the superoxide radical was accelerated by the hyperbaric conditions and the calcium ions, drugs such as superoxide dismutase and a calcium channel blocking agent (verapamil), prevented these paradoxes. Taurine decreased the oxygenation-induced lipid peroxidation of hepatocytes, and prevented the hypoxia-induced hepatocyte death in a calcium-containing medium, but not in a calcium-free medium. Taurine also protected the hepatocytes from injuries associated with the calcium and oxygen paradoxes due to the inhibition of sudden calcium influx into the hepatocytes.

Animals↗
PubMed1990

Use of magnetite particles as a contrast agent for MR imaging of the liver.

To evaluate the potential of dextran-coated magnetite (DM) particles in enhancing the detection of hepatocellular carcinoma with magnetic resonance (MR) imaging, the authors induced liver tumors in rats by oral administration of diethylnitrosamine and examined the rats before and after intravenous injections of DM with various iron concentrations. Because of the intense and preferential T2 relaxativity of DM, use of DM with an iron concentration of 10 mumol/kg yielded effective MR signal reduction in each normal liver at 1 hour after the injection. Because no significant signal change in the tumors was observed on DM-enhanced MR images, the contrast between hepatocellular carcinoma and adjacent uninvolved liver increased remarkably on even relatively T1-weighted images. The detection rate for the 89 tumors, including small tumors less than 2 mm in diameter, increased from 10% (nine of 89) before DM administration to 65% (58 of 89) with DM-enhanced T1-weighted imaging. Iron staining of rat liver performed about 1 hour after DM administration showed sparse deposits of DM selectively in reticuloendothelial cells but not in liver tumors.

Animals↗
PubMed1990

[A clinical study of complements as a marker of a hepatocellular carcinoma].

Serum complement C3, C4, and C3 proactivator (C3PA) have been evaluated for their diagnostic power in detecting a hepatocellular carcinoma (HCC) in patients with liver cirrhosis (LC). It was found that serum complement levels were lower in LC patients than in HCC patients and that difference of the serum C4 and C3PA levels between LC patients and HCC patients were statistically significant. In addition, serum C3 PA levels were found to correlate significantly with the serum gamma-GTP levels in HCC patients. Thus, using the cutoff values of C4 and C3PA as the mean values for HCC patients, examination of serum complement levels enabled the detection of 38% of the HCC patients with low AFP levels. These findings suggest that the examination of the serum complements may be a useful a tool for the detection of HCCs in LC patients.

Biomarkers, Tumor↗