L. Piret

The Osteoinductive Capacity of Differently Hcl-decalcified Bone Alloimplants

Three procedures to obtain bone inductive implants were tested heterotopically in 3-month-old allogeneic rats: 1) antigen-extracted HCl-decalcified at 4 degrees C, autolysed implant (AAA bone); 2) HCl-decalcified implant at 4 degrees C; 3) HCl-decalcified implant at room temperature. Each type of implant was either deep-frozen at -35 degrees C for at least 2 months or immediately freeze-dried. The bone inductive capacity of the differently HCl-decalcified cortical bone implant was evaluated at 2 months by isotopic strontium incorporation and by ash-weight measurements. Bone HCl-decalcification alone, either at 4 degrees C or at room temperature, gave a higher new bone yield than the freeze-dried AAA bone. The type or short-term preservation technique had no effect on the osteoinductive capacity of either of the differently treated implants, AAA bone expected.

Assessment of left ventricular diastolic function in patients receiving anthracycline therapy.

Abnormalities in left ventricular filling have been described as an early finding in coronary artery disease and in cardiomyopathy. The present study was undertaken to determine whether impaired diastolic function may be an early sign of anthracycline cardiotoxicity. Radionuclide left ventricular curves of 30 treated patients were compared with the curves of 17 normal, agematched, volunteers. The curves were analyzed for ejection fraction, peak filling rate (normalized for end diastolic counts and for stroke counts), time to peak filling rate and filling fraction in the first third of diastole normalized for cycle length. In 20 patients (Groups A and B), we analyzed the radionuclide ventriculography preceding the decrease of systolic function or a clinical congestive heart failure. In ten patients (Group C) who ended a treatment regimen without systolic dysfunction or clinically evident cardiotoxicity, we analyzed the ventriculography at the end of the therapy. Among the diastolic indexes, only the first third filling fraction was abnormal in a minority of the patients (6/20 in Groups A and B). Our findings suggest that diastolic dysfunction is uncommon in anthracycline treated patients prior to systolic dysfunction.

Radionuclide Absolute Left-ventricular Volumes During Upright Exercise - Validation in Normal Subjects By Simultaneous Hemodynamic Measurements

A nongeometric radionuclide technique for the determination of absolute left ventricular volumes was validated during exercise in nine normal subjects. Simultaneous reference stroke volume and cardiac output measurements were obtained by the Fick method. The reference left ventricular volumes were calculated by combining the Fick stroke volume and the isotopic ejection fraction. Data were collected at rest in the supine and upright positions and during 60° upright exercise, at three levels of increasing severity. At rest, from supine to upright position, the reference end-diastolic volume decreased significantly from 182±24 ml to 154±21 ml (mean±SD, P<0.005); during upright exercise of low intensity, end-diastolic volume increased to 176±24 ml (P<0.05); at maximal exercise, end-diastolic volume was not different from the resting value in upright position. The end-systolic volume gradually decreased at rest from 67±11 ml in the supine position to 54±8 ml in the upright position (P<0.05) and to 32±7 ml at maximal exercise (P<0.005). Compared with these reference data, the scintigraphic measurements were significantly lower on average by 23% for stroke volume, 21% for cardiac output, 22% for end-diastolic volume, and 23% for end-systolic volume. The overall changes in stroke volume (P<0.05) and end-systolic volume (P<0.001) occurring at rest and during exercise were correctly detected by the scintigraphic method but the smaller changes in end-diastolic volume (less than 15%) were not (P<0.15) because they were within the range of the precision of the technique. If subtle changes in left ventricular volume are to be quantitated, attempts should be made to reduce the random variability of the scintigraphic method.