Search PubMed⌕ Search

Biomedical subjects

J Kawai

Publications and source records attributed to J Kawai.

At least 109 records · Page 6Linked to original sources
PubMed1988

Alanine:glyoxylate aminotransferase activities in liver of Suncus murinus (insectivora).

1. The distribution of L-alanine:glyoxylate aminotransferase (AGT) activities were found in Suncus liver, 55% in particulate fraction and 45% in supernatant. 2. 65% of AGT activities in particulate were dependent on AGT isoenzyme 2 (AGT 2) having molecular weight 210,000, the remainder (35%) of AGT activities were dependent on AGT isoenzyme 1 (AGT 1) which have aminotransferase activity for serine. AGT activities in supernatant were dependent on AGT 1, AGT 2 and alanine:2-oxoglutarate aminotransferase (GPT), and their activity ratios were 10, 15 and 75%, respectively. 3. Km values for alanine were 0.52 mM; AGT 1, 3.3 mM; AGT 2, 0.88 mM; GPT measuring with AGT activity. AGT activity of GPT was inhibited by addition of glutamate and its Ki value was 1.8 mM. 4. Some other properties of AGT 1, AGT 2 and GPT are described.

Alanine Transaminase↗
PubMed1988

Organ distribution of rat kynureninase and changes of its activity during development.

Kynureninase activity was measured in various organs of the rat by a sensitive assay method based on the use of an HPLC system. High activities were detected in liver, kidney and spleen, and much lower activities in adrenals, intestine, lung, heart, brain, skeletal muscle and pancreas. Kynureninase of liver, kidney and spleen showed the same molecular weight (110,000) and the same isoelectric point (pI 5.4). They also showed the same properties of heat stability and apparent optimum pH. The enzymes in kidney and spleen were localized in the cytosol. The developmental study showed increasing activities of the enzyme after birth and a maximum on the 60th day in both liver and spleen. The activity in kidney increased after birth and reached a plateau on the 30th day.

Aging↗
PubMed1987

Reduction in antiviral activity of human interferon-gamma in acidic media with reference to structural change.

The fluorescence intensity of a unique tryptophan 36 in human interferon-gamma was drastically decreased below pH 4 with a concomitant decrease of antiviral activity. The region of residues 32-42 of human interferon-gamma was found by calculation to have a low hydrophobicity together with a high helical hydrophobic moment, and the net electric charge of this region having an amphiphilic helical structure changed significantly near pH 4. These results suggest that the region of residues 32-42 plays an important role in exhibiting antiviral activity.

Chemical Phenomena↗
PubMed1987

Role of macrophages as modulators but not as autonomous accessory cells in the proliferative response of immune T cells to soluble antigen.

The role of murine macrophages (M phi) and that of splenic dendritic cells (DC) were investigated in the antigen-specific proliferative response of memory T cells of mice primed with key-hole limpet hemocyanin (KLH) 6 weeks or more before. Peritoneal M phi, whether expressing Ia antigens or not, did not function as autonomous accessory cells (A cells). A-cell activity of the spleen adherent cell population, which comprised M phi in the majority and DC in the minority, was abolished by eliminating DC with a DC-specific monoclonal antibody and complement, and regained by the addition of a small number of DC. Though M phi did not function as autonomous A cells, they augmented the proliferative response in the presence of a small number of DC. This occurred not only in the presence of free antigen, but also when DC and/or M phi were pulsed with antigen. A culture supernatant of M phi having interleukin-1 activity was effective in enhancing the proliferation of T cells which responded to antigen-pulsed DC. On the other hand, interleukin-2 did not replace DC even in the presence of antigen-pulsed Ia+ M phi. We also investigated recently primed T cells, but no evidence was obtained in favor of the competence of M phi as autonomous A cells.

Animals↗
PubMed1987

Accessory cell functions of dendritic cells and macrophages in the thymic T-cell response to Con A.

Accessory cell (A cell) functions of splenic dendritic cells (DC) and peritoneal macrophages (M phi) were investigated in the Con A-stimulated proliferative response of thymic T cells. DC were more efficient as A cells than M phi in respect of their necessary cell numbers, Con A dose and culture period required for optimal response. Con A-pulsed T cells proliferated with the aid of lymphocyte activating factor(s) (LAF) derived from M phi, even in the apparent absence of A cells. Con A-pulsed M phi were superior to unpulsed M phi in the secretion of LAF to induce a high response of Con A-pulsed T cells. A cell activity of M phi in different preparations appeared to parallel the ability to secrete LAF, and was totally abolished by fixation of M phi with paraformaldehyde. The fixation of DC, however, resulted in only a partial reduction of the A cell activity. These results argue that both DC and M phi can serve as A cells in the T-cell response to Con A, but that the mechanism to manifest A cell activity is somewhat different between DC and M phi.

Animals↗
PubMed1985

Role of macrophages as modulators but not as autonomous accessory cells in primary antibody response.

The role of macrophages (M phi) in the in vitro primary antibody response of murine lymphocytes to sheep erythrocytes was investigated. Peritoneal M phi were activated to express Ia antigens either in vitro or in vivo. Nonactivated Ia- M phi were also examined. We observed that only Ia- M phi but also Ia+ M phi failed to trigger the antibody response, in contrast with splenic dendritic cells (DC) which served as potent and autonomous accessory cells, but that M phi modulated the level of response which was dependent primarily on the DC content of culture. The modulation appeared to incline to suppression rather than enhancement, when M phi were allowed to remain throughout the culture period for 4 days. A highly enhancing capacity of M phi, however, could be revealed by removing M phi 2 days after the initiation of culture, indicating that M phi exerted their suppressive effect more strongly in the late phase than in the early phase of in vitro antibody response. The modulatory activity seemed higher in Ia+ M phi than in Ia- M phi.

Animals↗
PubMed1984

Role of macrophages as modulators but not as stimulators in primary mixed leukocyte reaction.

The role of macrophages (M phi) and that of splenic dendritic cells (DC) in the allogeneic mixed leukocyte reaction (MLR) in the mouse have been investigated. In contrast with the high stimulatory capacity of DC, we obtained no evidence in favor of the competence of M phi, whether Ia + or Ia-, as an autonomous stimulator of MLR. However, M phi were found to modulate the level of MLR. Thus, M phi amplified the low level MLR to low dose DC and apparently suppressed the high level MLR to high dose DC. Ia + M phi seemed superior to Ia- M phi in the MLR-enhancing effect. M phi syngeneic to the responder and those to the stimulator suggest that M phi are modulators of immune responses triggered through the mediation of DC.

Animals↗
PubMed1984

Reconstruction of pulmonary artery with substitute valve--with special reference to size of conduit and valve.

Operative risk factors and postoperative late results were evaluated in 26 patients undergoing pulmonary artery reconstruction with a substitute valve. Seventeen extracardiac conduits bearing a valve were used in 16 patients and an in situ pulmonary valve insertion was carried out in the other 10. The surgical results were influenced by complexity of the underlying cardiac lesions and pulmonary vascular status, with a high mortality rate in patients with several cardiac defects including single ventricle, asplenia syndrome, complete atrioventricular canal etc. The mortality rate was 6% in patients with an immediate post-repair Ppv/sv of less than 0.75 and 77.8% in those with a Ppv/sv over 0.75. Postoperative Ppv/sv was mainly regulated by valve area index and a close correlation was obtained for the regression equation Ppv/sv = 0.41/(VAI)2 + 0.36 (r = -0.61, p less than 0.05). To obtain excellent hemodynamics with a Ppv/sv of less than 0.50, valve area index should be over 1.7 cm2/M2, and to eliminate re-implantation of the conduit after reaching adulthood, the diameter of the conduit should be 18 mm or more and the valve size 23 A, or more when a SJM valve is used.

Adolescent↗
PubMed1983

Angiocardiographic evaluation of ventricular septal defect--pre- and post-operative cardiac volume characteristics.

The characteristics of the left and the right heart volume in isolated ventricular septal defect were investigated in 62 patients before surgery and in 17 after corrective surgery, which was undergone at ages ranging from 0.5 to 13. Postoperative cardiac catheterization was performed one to two months after surgery. Preoperatively, the right atrial maximal volume increased in accordance with the pulmonary to systemic pressure ratio, and the left ventricular end-diastolic volume, the left atrial maximal volume and the right ventricular end-diastolic volume increased in accordance with the degree of the left-to-right shunt. These volumes decreased considerably after surgery, although they still remained above normal. The left ventricular mass also increased in accordance with the degree of the left-to-right shunt preoperatively and did not decrease postoperatively. The left and the right ventricular ejection fractions were close to or within normal limits preoperatively and remained so after surgery. On the basis of our results and the findings previously published in the literature, factors which may influence the postoperative cardiac function in ventricular septal defects were discussed.

Adolescent↗
PubMed1983

[Current status of surgical treatment of univentricular heart disease and complicated cardiac anomalies associated with asplenia and polysplenia syndrome].

Current status and problems in diagnosis and surgical treatment for complicated cardiac anomalies were assessed by analyzing surgical cases consisted of 32 univentricular heart cases, 27 asplenia syndrome cases, and 8 polysplenia cases. Univentricular heart cases consisted of 3 cases of type A, 8 cases of type B and 21 cases of type C. All of 7 cases performed corrective surgery were with bidirectional cross blood flow. Corrective surgery was performed on 7 cases including 6 cases of ventricular septation procedure with blood flow conversion and a case of modified Fontan procedure, and 2 were survived. Anatomical corrective surgery was performed for complicated cardiac anomalies on 4 cases with asplenia syndrome and 7 cases with polysplenia syndrome, and 2 and 6 cases were survived respectively. It was possible to perform functional corrective surgery on some cases who had difficulties for anatomical corrective surgery. For anatomical corrective surgery, it is preferable to use left ventricle as systemic ventricle. In splenic dysgenesis cases, main causes of late deaths were infection (asplenia syndrome) and complete A-V block (polysplenia syndrome) and it is necessary to clarify the immune mechanism and conduction system of the heart.

Abnormalities, Multiple↗
PubMed1982

Anatomically corrected malposition of the great arteries--case reports and a review.

Anatomically corrected malposition of the great arteries (ACM) is an extremely uncommon cardiac disease in which the great arteries arise from their appropriate ventricles despite abnormal spatial interrelations. Two patients with this malformation underwent successful surgical intervention for their associated anomalies. One was of situs solitus, d-loop and l-malposition and the other of situs inversus, l-loop and d-malposition of the great arteries. Fifty-three cases with accurate anatomical description were collected from the literature, and anatomical characteristics and associated anomalies were investigated. From the standpoint of anatomy and hemodynamics, we considered that ACM should be classified into atrioventricular concordant ACM, atrioventricular discordant ACM and ACM with situs ambiguus. Heart position and conus were variable. Dextrocardia and mesocardia were frequent. Bilateral conus was characteristic in concordant ACM, and subpulmonary conus was prominent in discordant ACM. The hypoplasia of the right heart and juxtaposition of the atrial appendages were in high incidence in cases of ACM. Surgical intervention was also discussed.

Angiocardiography↗
PubMed1982

Surgical results and factors affecting operative mortality in total anomalous pulmonary venous drainage.

Factors affecting the surgical results of total anomalous pulmonary venous drainage were evaluated in 17 patients in an attempt to establish an appropriate plan of management. The mortality rate correlated with age, size of interatrial communication, arterial oxygen saturation and left heart volume but not with pulmonary to systemic systolic pressure ratio, vascular resistance ratio and right ventricular volume. In cases where the symptoms appeared early in life, left heart volume was small and clinical features were severe. Four children with a left ventricular end-diastolic volume of less than 65% of normal died of low cardiac output syndrome. In those with an unusually small left heart, enlargement of the left atrium and/or delayed ligation of the anomalous vertical vein were considered more favorable. Left atrial and ventricular volumes were restored to normal after the surgery.

Age Factors↗