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Biomedical subjects

Y Shimazaki

Publications and source records attributed to Y Shimazaki.

At least 181 records · Page 10Linked to original sources
PubMed1988

Effects of zinc and EDTA on tissue cadmium in various smooth muscles in rabbit and guinea-pig.

1. The effects of zinc (Zn2+) and ethylenediaminetetra-acetic acid (EDTA) on tissue cadmium (Cd2+) were investigated in the smooth muscles of rabbit trachea, taenia coli, aorta and guinea-pig taenia coli. 2. After an Cd uptake in high-K2+ solution, samples were rinsed with cold high-K2+, cold Zn2+ or cold EDTA solution without Cd2+ and the results were quantitatively different from each other. 3. Concentration-response curves were obtained with each treatment of cold solution. 4. It is suggested that tissue Cd2+ can be divided into 3 fractions in the surface membrane and there is another fraction in cellular space.

Animals↗
PubMed1988

Quantitative cineangiographic analysis of ventricular volume and mass in patients with single ventricle: relation to ventricular morphologies.

With the use of biplane selective ventriculography, the ventricular volume, ejection fraction, and ventricular mass were evaluated in 28 patients with a single ventricle, and those with the left ventricular type (LV type, 12 patients) and right ventricular type (RV type, 16 patients) were compared. There were no significant differences in terms of age, hemoglobin, systemic oxygen saturation, or pulmonary-to-systemic flow ratio in the two groups. No patients with atrioventricular valve regurgitation were included. The ventricular cavity volume was calculated by the area-length method. The ventricular mass volume was determined as the shell volume created by subtracting the ventricular cavity volume from the total ventricular volume calculated by adding the free wall thickness to the chamber dimensions. The ventricular mass volume was converted to mass by multiplying by the gravity of the heart muscle. There was no significant difference between patients with the LV type and RV type of single ventricle with respect to the end-diastolic ventricular volume (188 +/- 53 and 179 +/- 61 ml/m2 in LV and RV types, respectively), end-systolic volume (88 +/- 31 and 84 +/- 27 ml/m2), or ejection fraction (0.54 +/- 0.06 and 0.52 +/- 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Volume↗
PubMed1988

Experimental and clinical study of crystalloid cardioplegic solution in neonatal period and early infancy. Effects of calcium and prostacyclin analogue.

The effects of calcium and a prostacyclin (PGI2) analogue in the glucose-insulin-potassium (GIK) cardioplegic solution for the neonatal period and early infancy were evaluated. The assessment was based mainly on semiquantitative scoring of mitochondrial damage and intracellular edema in postreperfusion biopsies. Experimentally, 45 isolated perfused newborn rabbit hearts (age, 0-2 days) underwent 2 hours of global ischemia at 15 degrees C with a single dose of GIK cardioplegic solution and were subsequently assigned to three groups: Group 1 hearts (n = 15) were infused with basic GIK cardioplegic solution alone (no added calcium, but measured at 0.1-0.2 mM/l); Group 2 hearts (n = 15) received GIK cardioplegic solution with calcium (1.2 mM); and Group 3 hearts (n = 15) received GIK cardioplegic solution with calcium and a PGI2 analogue (OP-41483, 300 micrograms/l). Group 3 hearts showed significantly lower mitochondrial damage and intracellular edema scores than did Group 1 and Group 2 hearts (p less than 0.05). Hemodynamic measurement (aortic flow and coronary flow) results after reperfusion were also better in Group 3 hearts than in the hearts of the other two groups (p less than 0.05). In the clinical study with 18 infants who were less than 3 months old, the same three cardioplegic solutions were used. Group 2 (n = 6) and Group 3 (n = 5) infants showed significantly lower mitochondrial damage scores than did Group 1 (n = 7) infants. Group 3 infants also showed significantly lower intracellular edema scores than did Group 1 and Group 2 infants.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Evaluation of long-term results of bicuspidalization annuloplasty for functional tricuspid regurgitation. A seventeen-year experience with 133 consecutive patients.

Between 1968 and 1985, 133 consecutive patients underwent bicuspidalization annuloplasty for moderate to severe functional tricuspid regurgitation associated with mitral or combined mitral and aortic valve disease. Over this period, the incidence of tricuspid valve replacement was only 2.3% (3/136 patients). There were 18 early deaths (13.5%) in the entire series--three (5.0%) of 60 patients in the last 5 years of the study--and 10 late deaths (8.7%). Actuarial survival rate for the entire series, excluding early deaths, was 91.0% +/- 3.0% at 10 and 17 years. There were seven reoperations (6.1%) on the tricuspid valve, needed because of residual or recurrent mitral valve lesions after the initial operation. Actuarial rates of freedom from reoperation on the tricuspid valve were 93.6% +/- 3.0% (10 years) and 69.7% +/- 16% (17 years) for the entire series: 78% +/- 10% (15 years) for the open mitral commissurotomy plus tricuspid annuloplasty group (44 patients); 90% +/- 9.0% (15 years) for the mitral plus tricuspid annuloplasty group (10); 75.2% +/- 22% (17 years) for the mitral replacement plus tricuspid annuloplasty group (58); and 92.6% +/- 7.0% (16 years) for the combined aortic and mitral valve surgery plus tricuspid annuloplasty group (21). Ninety-eight percent of the survivors were in New York Heart Association class I or II postoperatively. Of 21 randomly selected patients investigated by pulsed Doppler echocardiography, 14 (67%) had no regurgitation or grade 1/4 tricuspid regurgitation and the remaining seven (33%) had grade 2/4 regurgitation postoperatively. Our experiences suggest that bicuspidalization annuloplasty can be a reliable method in the vast majority of patients with functional tricuspid regurgitation.

Actuarial Analysis↗
PubMed1988

The structure of the pulmonary circulation in tetralogy of Fallot with pulmonary atresia. A quantitative cineangiographic study.

UNLABELLED: Cineangiograms of 172 patients with tetralogy of Fallot and pulmonary atresia were qualitatively and quantitatively analyzed retrospectively. FINDINGS: Twenty-eight (16%) patients had congenital absence of the central and unbranched hilar portions of the left or right pulmonary artery or both, and thus had congenitally nonconfluent pulmonary arteries. Five additional patients (3%) with originally confluent pulmonary arteries had nonconfluent ones because of an end-to-end surgical shunt, as did seven others (4%) because of thrombosis of one pulmonary artery. Among the 132 patients with confluent right and left pulmonary arteries, 70 (53% of 132) had incomplete arborization (distribution) of one or both, as did 23 (82% of 28) of those with congenitally nonconfluent pulmonary arteries (P for difference = 0.005). Ten (36% of 28) of the latter group had fewer than 10 pulmonary vascular segments (normal is 20) in continuity with central pulmonary arteries, compared with four (3%) of the former group. The proximal left and right pulmonary arteries were small but variable in size in all groups (median value 1.05 McGoon ratio), but were largest in the patients with confluent pulmonary arteries. Seventy-nine (60% of 132) patients with confluent left and right pulmonary arteries had large aortopulmonary collateral arteries, as did 100% of those with congenitally nonconfluent pulmonary arteries (P less than 0.001). The number of large aortopulmonary collateral arteries correlated inversely with the completeness of arborization of the left and right pulmonary arteries (P less than 0.0001). Inferences: Most patients with tetralogy and pulmonary atresia have gross morphologic abnormalities in the pulmonary vasculature and differ quantitatively in this regard from those with tetralogy and pulmonary stenosis. The prevalences of the various types of these abnormalities are considerably interrelated.

Adolescent↗
PubMed1988

Survival, functional status, and reoperations after repair of tetralogy of Fallot with pulmonary atresia.

DATA: Among 139 patients who underwent repair of tetralogy with pulmonary atresia, survival rates at 1 month and at 1, 5, 10, and 20 years were 85%, 82%, 76%, 69%, and 58%, respectively. The hazard function (instantaneous risk of dying) was greatest immediately after operation and declined thereafter, but a low constant hazard persisted for as long as the patients were followed up. Multivariately, the postrepair ratio between peak right ventricular and left ventricular pressures measured in the operating room provided the most information relative to the probability of death after repair, and cardiopulmonary bypass time the next. When morphologic abnormalities of the pulmonary circulation were considered in the multivariate analysis for risk factors for death, the size of the pulmonary arteries provided the most information, followed by the number of large aortopulmonary collateral arteries. The postrepair peak right ventricular/left ventricular pressure ratio was lower the day after operation than in the operating room in 65% of the patients in whom the measurements were made. Recurrent or residual ventricular septal defects necessitating rerepair occurred in four patients (3% of hospital survivors). Most surviving patients were in New York Heart Association class I at the time of follow-up. INFERENCES: Early, intermediate, and long-term survival is less good after repair of tetralogy with pulmonary atresia than after repair of tetralogy with pulmonary stenosis. This is related primarily to the greater prevalence of high peak right ventricular/left ventricular pressure ratio measured in the operating room in the former group. Both the postrepair peak right ventricular/left ventricular pressure ratio in the operating room and the probability of death are inversely related to the size of the pulmonary arteries and directly to the number of large aortopulmonary collateral arteries. This and inferences from other risk factors may be helpful in achieving better results in the future.

Blood Vessel Prosthesis↗
PubMed1988

Prediction of severe obstruction to right ventricular outflow after repair of tetralogy of Fallot and pulmonary atresia.

Cineangiograms were available for a quantitative retrospective study along with complete clinical information in 96 patients who underwent intracardiac repair of tetralogy of Fallot with pulmonary atresia. Multivariate analysis determined that the risk factors for too high a ratio (greater than or equal to 1) between the peak pressure in the right ventricle and that in the left, in the operating room about 30 minutes after repair, were as follows: size of the patient, small size of the right and left pulmonary arteries, and a larger number of large aortopulmonary collateral arteries. When, according to the multivariate equation, the predicted probability of this ratio being equal to or greater than 1 is 50% or more, consideration may be given to preliminary operations before repair; when the predicted probability is 70% or more, complete repair at that stage may be unwise.

Body Surface Area↗
PubMed1987

Analysis of the effects of the Blalock-Taussig shunt on ventricular function and the prognosis in patients with single ventricle.

Twenty-four patients with single ventricle, six with single left (SLV) and 18 with single right (SRV) ventricle, who received a Blalock-Taussig (BT) shunt at an average age of 3.2 years were studied. Ventricular function was assessed angiographically by end-diastolic volume index (EDVI) and ejection fraction (EF), and attempts were made to measure ventricular mass index (VMI) and VM/EDV. In 14 patients, the preoperative and postoperative results (average 2.4 years after placement of BT shunt) were compared in SLV (n = 5) and SRV (n = 9) groups. The SLV group showed significant increases in EDVI, VMI, and VM/EDV without a significant change in EF. The SRV group showed significant increases in EDVI and VMI, while EF decreased and VM/EDV was unchanged. Late death from congestive heart failure occurred in five patients with SRV. Three patients with atrioventricular valve regurgitation suffered late death. Among the patients with SRV, the late death group had significantly lower preoperative EF and VM/EDV compared with the survivors (n = 13). All of those with a preoperative EF of less than 0.50 and a VM/EDV of less than 0.35 g/ml suffered late death. In summary, patients with SRV appear to fail to develop adaptational hypertrophy to volume loading after the BT shunt procedure, with concomitant depression in ventricular pump function. Also, late cardiac failure seems likely to develop when low EF and VM/EDV are present preoperatively.

Child, Preschool↗
PubMed1987

Ultrastructural assessment of the infant myocardium receiving crystalloid cardioplegia.

The effectiveness of cold crystalloid potassium cardioplegia was evaluated in 26 infants (age 27 days to 17 months, 7.5 +/- 5.2 months, mean +/- SD) who underwent intracardiac repair for various cardiac lesions. A myocardial biopsy sample was obtained before aortic cross-clamping (AXC) and 20 min after release of AXC (AXC time 22 to 161 min, mean 68 +/- 37 min), and semiquantitative assessment of the mitochondrial structure was made by scoring. The post-AXC score was significantly higher than the pre-AXC score (1.1 +/- 0.6 vs 0.4 +/- 0.4, p less than .001) for the whole group. Patients receiving preoperative catecholamine support had higher pre- and post-AXC scores than those who did not (pre-AXC score 0.7 +/- 0.4 vs 0.2 +/- 0.3, p less than .01; post-AXC score 1.4 +/- 0.5 vs 1.0 +/- 0.5, p less than .05). Infants less than 3 months old (n = 7) and those 3 to 12 months old (n = 11) had higher pre AXC scores than infants over 12 months old (n = 8). With respect to post-AXC score, only those less than 3 months old had significantly higher values than the other infants. These results indicate that the myocardial injury was not fully prevented by crystalloid potassium cardioplegia in infants, and that infants with preoperative heart failure and less than 3 months old appear to have increased myocardial susceptibility to ischemic injury under cardioplegia.

Aorta↗
PubMed1986

Identification with Monoclonal Antibodies of a Second Antigenic Domain on Avena Phytochrome that Changes upon Its Photoconversion.

An enzyme-linked immunosorbent assay that revealed an antigenic difference between the red-absorbing and far-red-absorbing forms of phytochrome (Pr and Pfr, respectively) near its amino terminus (Cordonnier M-M, H Greppin, LH Pratt 1985 Biochemistry 24: 3246-3253) was used to screen eight additional monoclonal antibodies directed to phytochrome from etiolated oats. While six of these antibodies detected Pr and Pfr with equal affinity, two of them, designated Oat-9 and Oat-16, bound to Pfr 1.6 to 2.3 times better than to Pr. Competitive enzyme-linked immunosorbent assays indicate (a) that Oat-9 and Oat-16 probably bind to the same domain on phytochrome and (b) that this domain is at least 3.5 nanometers away from the epitope near its amino terminus that was shown earlier to change upon phototransformation. Neither the absorbance spectra of Pr and Pfr, nor the rate of dark reversion of Pfr to Pr, was influenced by the presence of Oat-9. Immunoblotting of sodium dodecyl sulfate polyacrylamide gels after electrophoretic separation of phytochrome fragments obtained by endogenous proteolytic digestion indicates that Oat-16 binds to an epitope located on the chromophore half of this chromoprotein. The observation that the epitope recognized by Oat-9 and Oat-16 is also present on at least some of the immunochemically distinct phytochrome that is obtained from green oat shoots (Shimazaki Y, LH Pratt 1985 Planta 164: 333-344), together with the evidence that this epitope undergoes a change upon photoransformation, indicates that it may play an important role in phytochrome function.

Journal Article↗
PubMed1986

Ventricular volume of single ventricle with or without palliation and after corrective surgery--concept of septation procedure.

Ventricular volume measurements of single ventricle were carried out in 20 patients with or without palliation and in 2 after total correction. In the former 20 patients, 6 had a single left ventricle and 14 a single right ventricle, anatomically. Two having total correction were associated with undivided ventricle. In the 20 patients with or without palliation, ventricular end-diastolic volume ranged from 64 to 206 (115 +/- 42) percent of the sum of the normal left and right ventricular volumes. Ejection fraction of single ventricle ranged from 0.40 to 0.64 (0.55 +/- 0.06). There was no significant difference in ventricular volume and ejection fraction between patients with a single left and right ventricle. There was high correlation of ventricular volume with pulmonary to systemic blood flow ratio (r = 0.66, p less than 0.005). This indicates that systemic-to-pulmonary shunt should increase ventricular volume of single ventricle. In two patients after total correction, total ventricular volume was 136 and 166% of the sum of the normal left and right ventricular volumes. Total ejection fraction was 0.55 and 0.33 in the first and second patient, respectively. The prosthetic ventricular septum bulged toward the right ventricle during systole and this shift made the left ventricular volume increase and ejection fraction decrease. Right-to-left ventricular volume ratio at end-diastole was 0.74 and 0.67 in the first and second patient, respectively. These results suggest that 1) larger ventricular volume than the sum of the normal left and right ventricular volumes would be required for septation of single ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

Heart Septum↗