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Biomedical subjects

R J Boucek

Publications and source records attributed to R J Boucek.

At least 73 records · Page 4Linked to original sources
PubMed1982

Cell-type differences in the serum and cyclic AMP-dependent regulation of ornithine decarboxylase activity in two cultured fibroblast types.

Serum re-feeding stimulated ornithine decarboxylase (ODC) activity 8 to 10-fold in FS fibroblasts and 5 to 8-fold in 3T3 fibroblasts. Addition of dibutyryl cyclic AMP or 3-isobutyl-1-methylxanthine at the time of serum re-feeding further stimulated ODC activity in 3T3 fibroblasts but inhibited the serum stimulation of ODC activity in FS fibroblasts. It is suggested that serum and cyclic AMP independently regulate ODC activity in cultured fibroblasts.

1-Methyl-3-isobutylxanthine↗
PubMed1982

Myocardial injury in infants with congenital heart disease: evaluation by creatine kinase MB isoenzyme analysis.

Total creatine kinase (CK) and the myocardial isoenzyme CK MB activity were prospectively determined in 282 children hospitalized for cardiac catheterization and evaluation for suspected congenital cardiac abnormalities and compared with a hospitalized control group of children without such abnormalities. The percent CK MB and CK MB activity were abnormally elevated in symptomatic children with a large left to right shunt due either to a large ventricular septal defect (n = 22; p less than 0.001) or to complete atrioventricular canal (n = 10; p less than 0.001). Serum CK MB activity and percent CK MB were significantly related to the size of the shunt and the age of presentation with clinical symptoms of congestive heart failure in infants with a ventricular septal defect. CK MB activity was abnormally elevated in infants with symptomatic coarctation of the aorta, either with or without a ventricular septal defect (n = 15; p less than 0.001), and in infants with symptomatic aortic stenosis (n = 4; p less than 0.02). In contrast, CK MB activity was normal in asymptomatic children with coarctation of the aorta (n = 14) or aortic stenosis (n = 8) despite comparable systolic pressure gradients. CK MB activity and percent CK MB were abnormally elevated in those children with the cyanotic congenital cardiac abnormalities of either transposition of the great arteries (n = 32; p less than 0.001) or right ventricular outflow tract obstruction (n = 31; p less than 0.001). These results suggest that children with congenital cardiac abnormalities may have significant myocardial cell injury and release of CK MB that may be detected by the determination of serum CK MB activity. Cell injury may be secondary to arterial desaturation or acute pressure-volume overload, or both, as manifested by clinical symptoms of heart failure and measured hemodynamic variables.

Aortic Coarctation↗
PubMed1982

Functional and metabolic preservation of the immature myocardium with verapamil following global ischemia.

This study investigated the effects of the calcium antagonist verapamil on the functional and biochemical recovery of the immature heart following 30 minutes of normothermic ischemia. Verapamil (0.2 mg per kilogram of body weight) was infused into the aortic root in 5 puppies (8 to 10 weeks of age) prior to cardiopulmonary bypass. Five additional puppies received saline solution as a control. Left ventricular developed pressure, rate of rise of left ventricular pressure (dP/dt), left ventricular endsystolic pressure-diameter relationship (emax), compliance, and water content were assessed before and after bypass. Serial myocardial biopsies for adenosine triphosphate (ATP) and creatine phosphate were obtained. Puppies pretreated with verapamil recovered more than 80% of the preischemic left ventricular developed pressure, dP/dt, and emax in contrast to 50% recovery in the controls (p less than 0.05). The ATP content declined 40% during the interval of ischemia in the control puppies, versus 14.6% in the verapamil-treated puppies (p less than 0.05). Myocardial compliance was preserved in the verapamil-treated puppies and was associated with significantly less myocardial water content (78% versus 80.1% in the controls)(p less than 0.01). This study demonstrates the protective effects of verapamil on the immature heart during ischemic arrest. These results suggest that verapamil may be a useful adjunct to current methods of protecting the infant heart during cardiopulmonary bypass.

Adenosine Triphosphate↗
PubMed1982

Radionuclide ventriculography for assessment of absolute right and left ventricular volumes in children.

We determined absolute right and left ventricular volumes and cardiac output from the equilibrium radionuclide angiogram in 26 children, ages 3 months to 18 years, with diverse types of heart disease. We validated these results by comparing them with left ventricular (20 patients) and right ventricular (16 patients) cineangiographic volumes and cardiac output. Radionuclide volumes and cardiac outputs were determined in two ways: by a geometric method (area-length for left ventricle, Simpson's rule for right ventricle) and by a count-based method (correcting ventricular regional counts for frame duration, acquisition time, venous blood counts and attenuation). Both methods for estimating left ventricular end-diastolic volume compared favorably with cineangiography (correlation coefficients greater than 0.90). The count-based method also correlated well for the right ventricle. End-systolic measurements were not possible. Count-based assessment of cardiac output also correlated well with cineangiographic values. We conclude that right and left ventricular volumes and cardiac output can be reliably measured in children with equilibrium radionuclide ventriculography.

Adolescent↗
PubMed1982

Polyamine metabolism during the perinatal development of the rabbit right and left ventricle.

The right ventricular (RV) and left ventricular (LV) free wall weights, ornithine decarboxylase (ODC) specific activity and polyamine content were determined in fetal, 1-, 2-, 7-, 14-, and 21-day-old rabbit hearts. There was a significant increase in the LV free wall weight and a decrease in RV free wall weight between 1-7 days. By day 7 the LV/RV mass ratio doubled and reached a ratio comparable to that seen in adult rabbit hearts. The rate of change in the LV and RV free wall weights were comparable after day 7. There was a significant increase in LV ODC specific activity and a decrease in RV ODC specific activity after birth. The LV ODC specific activity was significantly greater than RV ODC specific activity in both 1 and 2 day old rabbit hearts whereas they were not significantly different in 7 and 14 day old rabbit hearts. The molar content (nmoles/mg wet weight or nmoles/mg protein) of putrescine decreased approximately 3-fold after birth in the RV but increased approximately 2-fold in the LV. The molar content of spermidine and spermine was transiently increased after birth (1 day old) in both RV and LV with approximately a 2-fold increase in spermidine and a 2.5-fold (LV) and 4-fold (RV) increase in spermine content. The increase in LV putrescine content after birth was due, at least in part, to the observed increase in ODC specific activity in the LV free wall. The putrescine/spermidine ratio increased in the LV and decreased in the RV immediately after birth up to day 7. As opposed to the short-lived increase in spermidine and spermine observed in both the RV and the LV free wall, increased ODC specific activity and putrescine accumulation uniquely characterized the preferential growth of the LV between day 1 and 7.

Age Factors↗
PubMed1982

Polyacrylamide-bismuth for postmortem coronary arteriography.

High quality postmortem human coronary arteriograms are obtained by injecting an acrylamide-bismuth mixture into the isolated aortic root under physiologic pressure. The acrylamide advances to the terminal size (20 micrometer.) arterioles, polymerizes, and remains within the vessels during the processing of tissue for histologic studies. Because the polyacrylamide does not affect the arterial wall morphology or the surrounding myocardium, the acrylamide-bismuth injection technique offers the clarity of the cast-corrosion procedure for postmortem radiograms fo the epicardial and intramural coronary arteries and adds the capability for histologic studies of arterial and myocardial tissues.

Acrylic Resins↗
PubMed1981

Desmosines in human urine. Amounts in early development and in Marfan's syndrome.

Desmosines from 24 h human urine samples were isolated, characterized and quantified. The desmosines are in peptidyl form (1000--1500 molecular weight), and their amount is decreased by two-thirds between 7 and 25 years of age. Patients with Marfan's syndrome have significantly lower urinary amounts of desmosines than do comparable controls during the early development period.

Adolescent↗
PubMed1981

A comparison of ornithine decarboxylases from normal and SV40-transformed 3T3 mouse fibroblasts.

Ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) has been purified from 3T3- and SV40-transformed 3T3 mouse fibroblasts by affinity chromatography, and the physicochemical properties of the two enzymes compared. Measured properties include molecular weight of the active species, subunit molecular weight and specific activity of the purified enzymes, kinetic parameters, thermostability, degradation rate in vivo and immunological cross-reactivity. Although crude extracts of the transformant possess more ornithine decarboxylase activity per mg of protein than the parent strain, there is no evidence for the appearance of an altered form of the enzyme in these cells. The results reported in the present paper indicate that the increased ornithine decarboxylase activity in the transformed cells is the result of higher enzyme biosynthesis de novo.

Animals↗
PubMed1980

Coronary arteriograms and myocardial scintigrams in the electrocardiographic syndrome of septal fibrosis.

Coronary artery disease (CAD) and myocardial perfusion were assessed by arteriograms and scintigrams (Technetium-99 microspheres alone or combined with Iodine-131 albumin macroaggregates) in 178 angina pectoris patients with and without the electrocardiographic (ECG) syndrome of septal fibrosis and with greater than or equal to 70% obstruction in one or more coronary arteries. The ECGs of 96 patients without angiographic evidence of obstructive CAD were also examined for the ECG syndrome of septal fibrosis. Patients with the ECG syndrome of septal fibrosis have significantly higher incidences of positive exercise stress test, of greater than or equal to 70% narrowing of the proximal left anterior descending (LAD) artery, of severe proximal LAD disease, and of more extensive left ventricular hypoperfusion than patients without the ECG syndrome. The fact that only 4% of patients without obstructive CAD have the ECG syndrome of septal fibrosis indicates the usefulness of the syndrome in identifying a subset of angina pectoris patients with advanced CAD of the proximal LAD and diffuse left ventricular hypoperfusion.

Angina Pectoris↗
PubMed1980

Left ventricular function in cyanotic congenital heart disease.

Left ventricular function was studied with quantitative biplane cineangiocardiography in 39 preoperative and 23 postoperative patients with cyanotic congenital heart disease. Diagnoses included pulmonary atresia or critical pulmonary stenosis with intact ventricular septum (group 1), tricuspid atresia (group 2) and pulmonary atresia with ventricular septal defect (group 3). Preoperative patients ranged in age from 1 day to 7 years and postoperative patients from 7 weeks to 23 years. Left ventricular end-diastolic volume was increased in preoperative patients in groups 1 and 2 (132 and 136 percent of normal, respectively) but was normal in patients in group 3. Left ventricular ejection fraction was decreased to a similar extent in preoperative groups 1 to 3: 0.54, 0.55 and 0.56, respectively. After a shunt procedure left ventricular end-diastolic volume increased to 228 and 266 percent of normal in groups 1 and 2, respectively, but remained within normal limits in group 3. Left ventricular ejection fraction was normal in postoperative group 1 patients, whose ages averaged 1.8 years, but remained decreased in group 2 and 3 patients, whose ages averaged 8.1 and 5.6 years, respectively. Duration of cyanosis and degree of left ventricular dilatation appear to be important variables in regard to pump function in patients with cyanotic congenital heart disease.

Adolescent↗
PubMed1980

The mural left anterior descending coronary artery, strenuous exercise and sudden death.

Postmortem studies of three ostensibly healthy persons whose unheralded death occurred incidental to strenuous exercise revealed an obstructed but mural left anterior descending (LAD) artery, diminished vascularity to the posterior left ventricle and ventricular septum, and morphologic evidence of patchy, ischemic necrosis of the ventricular septum in different stages of healing. Although mural coronary arteries are considered a normal anatomic variant, our observations, coupled with reported clinical studies, strongly suggest that systolic constriction of the LAD artery may precipitate death in selected subjects.

Adolescent↗
PubMed1980

Clinical and pathologic features of obstructive disease in the predominant right and left coronary circulations in man.

The clinical features and the location and severity of obstructive coronary artery disease are contrasted in 98 patients with predominant left and 99 patients with predominant right coronary circulations. A significantly higher incidence of ventricular conduction disturbances and a greater incidence and severity of obstructive coronary artery disease (greater than or equal to 70% cross-sectional narrowing in the proximal left anterior descending, circumflex and right coronary arteries and their major branches) distinguish the predominant left from the predominant right coronary circulation. The results suggest an anatomically disadvantaged status for the predominant left compared with the predominant right coronary circulations with respect to ventricular conduction disturbances and to coronary atherogenesis in man.

Arterial Occlusive Diseases↗
PubMed1980

Total anomalous pulmonary venous connection in infancy. Ten years' experience including studies of postoperative ventricular function.

The surgical experience with total anomalous pulmonary venous connection (TAPVC) at the Venderbilt Hospital between the years 1969 and 1979 was reviewed. Twenty-five patients with TAPVC were studied. All but one patient presented at less than 1 year of age, and 11 patients were operated upon in the first 2 weeks of life. Operative mortality rate was 20% (5/25). Four of the five deaths were in critically ill neonates requiring preoperative ventilatory support. All operative deaths were in patients with pulmonary venous obstruction. All operative survivors have been followed for a mean 4.5 years (6 months to 10 years). There have been no late deaths or cases of symptomatic pulmonary venous obstruction. All children have had normal growth patterns. Ten patients have been recatheterized. Pulmonary artery systolic pressure, which was markedly elevated prior to operation, fell to normal levels after operation. Ventricular function has been evaluated by quantitative angiocardiography in nine patients before and after operation. Left ventricular size and function were markedly depressed preoperatively and rose to normal levels in postoperative survivors. Left atrial maximal volume was found to be 94% of normal values. These data support the contention that preoperative pulmonary venous obstruction is the single risk factor predicting higher risk of operative death. The presence of severe depression of left ventricular size and function preoperatively does not predict a higher operative risk, and postoperative survivors can expect normal ventricular function.

Angiocardiography↗