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Biomedical subjects

H Sawada

Publications and source records attributed to H Sawada.

At least 523 records · Page 29Linked to original sources

[Evaluation of regional wall motion of the left ventricle before and after nitroglycerin administration in patients with ischemic heart disease: comparison between two-dimensional echocardiograms and coronary angiograms].

Effects of nitroglycerin (NTG) on segmental wall motion and pump function of the left ventricle (LV) were studied in 19 patients with ischemic heart disease (IHD) and 10 normal controls by two-dimensional echocardiography (2DE) and coronary arteriography (CAG). Short-axis cross-sectional images of the LV at the mitral valve, papillary muscles and the apex were recorded and subdivided into quadrants at each level. The center of gravity of the end-diastolic LV cavity and the axis intersecting this point and the right side of the posterior end of the interventricular septum were used as the reference point and line. The areas of whole sections and of each quadrant at end-diastole (Ad) and end-systole (As) were measured by the computer. Regional contractility and pump function of the LV were evaluated by (Ad-As)/Ad and (Ad-As) of quadrants and sections. The results were as follows: Blood pressure (BP), Ad and (Ad-As) of sections significantly decreased after NTG administration. (Ad-As)/Ad of the sections with normal wall motion showed no significant change after NTG. (Ad-As)/Ad of the quadrants with hypokinetic segmental wall motion showed a tendency to increase after NTG in contrast with the normal quadrants which showed no significant change. CAG findings and hemodynamic parameters in patients who showed a significant increase in (Ad-As)/Ad of all sections after NTG (Gr. I) were compared with those in patients who showed a decrease in (Ad-As)/Ad of all sections (Gr. II). There was no significant correlation between CAG findings in Gr. I and Gr. II. The only difference between these two groups before NTG was that mean Ad of sections in Gr. I was significantly greater than that of Gr. II. After NTG, Gr. I showed a significant decrease of BP, but Gr. II did not show any significant change. (Ad-As) of sections in Gr. I increased or showed no change after NTG, but those in Gr. II decreased. In conclusion, NTG can reverse wall motion asynergy, especially in hypokinetic segments, and produce favorable changes in pump function in patients with increased Ad before NTG. The mechanism of NTG to improve wall motion and pump function is considered to be afterload and preload reduction.

Blood Pressure↗

[Computer analysis of wo-dimensional echocardiogram for the quantitative evaluation of left ventricular asynergy in myocardial infarction].

Quantitative assessment of left ventricular asynergy in myocardial infarction was made by computer analysis of the two-dimensional echocardiogram. Short-axis cross-sectional images of the left ventricle at the levels of the mitral valve, papillary muscle and apex were recorded by a phased array sector scanner in 20 patients with myocardial infarction and ten normal controls. End cardial and epicardial outlines at end-diastole and end-systole were traced and analyzed by a computer system. Short-axis cross-sectional images of the left ventricle were divided equally into octants and analyzed with a fixed external reference system, using the center of gravity of end-diastolic left ventricular cavity and the axis intersecting this and the right side of the posterior interventricular septum as the reference point and line. Segmental hemiaxis, area, wall thickness and those changes during cardiac cycle were measured and calculated in each octants. Regional contractility of the left ventricle was evaluated by systolic percent change of segmental hemiaxis, area and wall thickness. These parameters were significantly reduced in the infarcted segments documented by left ventriculography and electrocardiography. The area method is better than the hemiaxis system in both reproducibility and variability. The center of gravity of the left ventricular cavity determined by the computer shifted slightly towards the anterior wall during systole in normal subjects, possibly reflecting anterior swinging motion of the entire heart. The center of the gravity of the left ventricular cavity in myocardial infarction showed the tendency to shift towards the infarcted region, suggesting the possibility that the location of asynergic area can be detected by determining the direction of the gravity center shift during systole in patients with a single infarction. This finding gives a basis of using the fixed reference system for the detection of asynergy. The use of computers for the analysis of short-axis two-dimensional echocardiographic images is very useful for the quantification of regional contractility of the left ventricle in a clinical setting.

Computers↗

[Effects of cefoxitin on infections secondary to hematopoietic malignancies].

Cefoxitin (CFX) was administered to 12 patients for evaluation of clinical effects of CFX against secondary infections complicated with hematopoietic malignancies, and the following results were obtained. 1. The clinical effects were excellent in 1 and good in 8 out or 11 cases with efficacy rate of 81.8%. Out of 12 cases treated with CFX, 1 case was excluded from clinical evaluation because of prophylactic use. It is noted that all cases with pyelitis showed good response to CFX. 2. The serum levels of CFX were determined in 1 patient with renal failure. After intravenous drip infusion of 2 g in 200 ml of glucose solution, the serum concentrations were 67.2 micrograms/ml and 7.53 micrograms/ml at 14 hours and 24 hours (after hemodialysis), respectively. 3. No side effects attributed to CFX were observed. These results indicate that CFX is an effective and safe antibiotic for the treatment of severe infections accompanying hematopoietic malignancies.

Adult↗

Host factors and susceptibility to rubella virus infection: the association of HLA antigens.

To examine the role of host-dependent factors to natural rubella infection, the positive rates of HAI antibody according to HLA-A and -B antigens were studied in 93 children, aged 9 to 10, who were exposed only to a recent epidemic (single-exposure group), and in 199 adult females, aged 18 to 23, who were exposed also to a former epidemic (dual-exposure group). Furthermore, the phenotype frequencies of HLA antigens were investigated in seronegative subjects in both groups, as well as in 58 adult female vaccinees, in comparison with those of the Japanese population. The seropositive rates by the HLA antigens, 38.7% and 73.4%, respectively, in each exposure group were found in subjects having some HLA antigens. Several of these candidate HLA antigens varied in phenotype frequencies in seronegative subjects of all three groups from those of the average Japanese. Although a few types were statistically significant, no contradictory findings in susceptibility were obtained among the groups during the study, which suggested strongly that subjects with HLA-Bw51 and -Bw16 are susceptible. In addition, when the seropositive rates were compared in all combinations of HLA-A and -B antigens classified according to expected susceptibility, the positive rates were arranged in order of susceptibility with significant statistical differences in several groups.

Adult↗

Familial acute myelogenous leukemia associated with RNA virus and polymorphism of 1qh+.

In order to investigate the genetic background of leukemogenesis of two brothers with acute myelogenous leukemia (AML), they and their family members were studied genetically, immunologically, virologically, and cytogenetically. Their parents were first cousins once removed and had the same or a very close type of human leukocyte antigen (HLA) and blood groups. In all five non-leukemic family members the immunoglobulin G (IgG) level was elevated, and in two healthy siblings the IgM level was beyond the normal range. The RNA reverse transcriptase activity in serum of the younger brother (Case 2) with AML was elevated. A cytogenetic study of the family revealed polymorphism of 1qh+. Based on these findings, we discuss the genetic and environmental factors of familial leukemia.

Adult↗

Seroepidemiologic studies of acute hemorrhagic conjunctivitis virus (enterovirus type 70) in West Africa. II. Studies with human sera collected in West African countries other than Ghana.

Human sera were collected in Senegal, Nigeria, Ivory Coast, Dahomey, Liberia, Gabon and Togo during the pre-epidemic period of acute hemorrhagic conjunctivitis (AHC) from 1965 to 1969, and tested for virus neutralizing (VN) antibody to enterovirus type 70 (EV70). Of these, 1109 (91%) were antibody negative (less than equal to 1:4), 116 (9%) neutralized at a dilution of 1:8 or over, and 45 (4%) at dilutions of at least 1:16. The distribution pattern is not significantly different from that of sera collected from Kenya in 1967 or from army recruits in the United States, Argentina, Brazil and Colombia in the 1960s. Sera collected during the post-epidemic period (1970 to 1977) in Senegal, Sierra Leone, Mali, Upper Volta, Chad, Niger and Gabon were also examined; 1573 (68%) were VN antibody negative (less than or equal to 1:4), while 733 (32%) and 433 (19%) had titers of 1:8 or greater and 1:16 or over, respectively. There is a significant difference in distribution between pre- and post-epidemic antibody titers (p less than 0.001), although the incidence of AHC was lower in these countries than in Ghana and Southeast Asia. The prevalence of VN antibodies tends to be lower in the dry, hot inland areas and thus humid coastal monsoonal climates and dense populations seem to favor the spread of AHC.

Adolescent↗

Lytic enzyme produced by Pseudomonas aeruginosa concomitantly with bacteriophage PS17. Purification, characterization, and comparison with PR1-lysozyme.

A bacteriolytic enzyme was found to be produced, concomitantly with the progeny phage, in Pseudomonas aeruginosa P14 infected with phage PS17. The enzyme, named PS17-lysozyme, was purified by acrinol treatment, two cycles of Amberlite CG-50 chromatography, and SP-Sephadex C-50 chromatography. Homogeneity of the preparation was demonstrated by three electrophoretic techniques. PS17-lysozyme behaved like a basic protein (pI, 9-10) consisting of a single polypeptide chain (molecular weight, 24,500) and showed the substrate specificity as hen egg-white lysozyme. The enzyme exhibited much higher specific activity than the egg-white enzyme when assayed with chloroform-killed P. aeruginosa P14 as a substrate. These characteristics, as well as the amino acid composition, were very similar to those of PR1-lysozyme; a bacteriolytic enzyme produced in mitomycin C-induced P. aeruginosa P15 concomitantly with a phage-tail-like bacteriocin, pyocin R1 (Ochi et al. (1978) J. Biochem. 83, 727-736). However, the behavior of these two lysozymes from P. aeruginosa in Amberlite CG-50 chromatography and some other properties indicated that they were not identical, though they were similar. The results are in accord with the view that pyocin R1 may be a defective form of a bacteriophage closely related to but not identical with phage PS17.

Amino Acids↗

Microsomal reductase for aromatic aldehydes and ketones in guinea pig liver. Purification, characterization, and functional relationship to hexose-6-phosphate dehydrogenase.

An NADPH-specific aromatic aldehyde-ketone reductase located in guinea pig liver microsomes can be effectively solubilized with nonionic detergents, but not with bile salts and hydrolytic enzymes. Destruction of microsomal membranes by nonionic detergents or acetone treatment leads to significant activation of the reductase, indicating that the enzyme is partly latent in intact microsomes. After solubilization with Triton X-100, the reductase has been highly purified. The purified enzyme catalyzes the NADPH-linked reduction of xenobiotic aromatic aldehydes and ketones as well as 3-ketosteroids, notably 5 alpha- and 5 beta-dihydrotestosterones. The reductase activities for xenobiotic carbonyl compounds and for 3-ketosteroids are each inhibited by addition of the other type of substrate and show the same pH optimum, cofactor requirement, and heat stability, indicating the same enzyme is responsible for the reduction of the two types of substrates. Hexose-6-phosphate dehydrogenase, purified from guinea pig liver microsomes, acts as a more effective NADPH generator for the reductase than yeast and guinea pig liver cytosolic glucose-6-phosphate dehydrogenase. Evidence has been obtained that hexose-6-phosphate dehydrogenase undergoes a functional interaction with the reductase, facilitating the provision of NADPH to the reductase activity both in the reconstituted system and in microsomes.

Alcohol Oxidoreductases↗

Adenosine deaminase and ecto-5'-nucleotidase activities in various leukemias with special reference to blast crisis: significance of ecto-5'-nucleotidase in lymphoid blast crisis of chronic myeloid leukemia.

Adenosine deaminase (ADA) and ecto-5'-nucleotidase (5'-N) activities were examined in peripheral leukocytes from patients with leukemias, including nine patients with chronic myeloid leukemia (CML) in blast crisis. Four of none cases of CML in blast crisis were myeloid and the remaining lymphoid morphologically. The diagnosis of CML in lymphoid blast crisis was further contributed by the measurement of terminal deoxynucleotidyl transferase (TdT) activity. In all four cases of lymphoid blast crisis and one of myeloid blast crisis, leukemia cells had high 5'-N activity, while there was a little or no detectable activity in those from four cases of myeloid blast crisis and all of CML in chronic phase. ADA activity was high in seven of nine patients with blast crisis. Taken together, leukemia cells from two cases of lymphoid blast crisis had high ADA and 5'-N activities comparable to those in acute lymphocytic leukemia (ALL) cells. In contrast, the enzyme activities of leukemia cells from all but one patient in myeloid blast crisis were in a range similar to acute myeloid leukemia cells. The implications of these findings are as follows: (1) 5'-N may be used as a new biochemical marker of CML in lymphoid blast crisis. (2) Some lymphoid cells of CML in blast crisis have high ADA, 5'-N, and TdT activities and thus are very similar to ALL cells.

5'-Nucleotidase↗