Nuclear cardiology, current applications in clinical practice

Assessment of effects of a Cordia salicifolia extract on the radiolabeling of blood constituents and on the morphology of red blood cells

Effects of a Cordia salicifolia (porangaba) extract on the labeling of blood cells (BCs) with technetium-99m ((99m)Tc) and on the morphology of red BCs were evaluated. Labeling of cellular and molecular structures with (99m)Tc depends on a reducing agent. Some physical characteristics, as visible absorbance spectrum, electric conductivity, and refractive index of this porangaba extract, were also determined. Blood samples from Wistar rats were incubated with porangaba extract or with 0.9% NaCl (control). Labeling of blood constituents with (99m)Tc was performed. Plasma (P) and BCs, both soluble (SF-P and SF-BC) and insoluble (IF-P and IF-BC) fractions, were separated. The radioactivity in each fraction was counted, and the percentage of radioactivity incorporated (%ATI) was calculated. Blood smears were prepared, fixed, and stained, and the morphology of the red BCs was evaluated. Data showed an absorbance peak at 480 nm and electric conductibility and refractive index concentration-dependent. Porangaba extract decreased significantly (P < .05) the BC, IF-P, and IF-BC %ATI, and no modifications were verified on the shape of red BCs. Analysis of the results reveals that some physical parameters could be useful to aid in characterizing the extract studied. Moreover, it is possible that chemical compounds of this extract could have chelating/redox actions or be capable of binding to plasma and/or cellular proteins.

Comparison of gated SPECT, echocardiography and cardiac magnetic resonance imaging for the assessment of left ventricular ejection fraction and volumes

BACKGROUND

Left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV) can be determined non-invasively by two-dimensional enchocardiography (ECHO), gated sinle photon emission computed tomography (GSPECT) and cardiac magnetic resonance imaging (CMRI). This study was designed to analyze the concordance between LVEF, EDV and ESV values derived from ECHO, GSPECT and CMRI.

METHODS

ECHO, GSPECT and CMRI were performed in a group of 21 patients with suspected coronary artery disease. LVEF, EDV and ESV values were calculated.

RESULTS

The mean LVEF measured with GSPECT, ECHO and CMRI were 55.9+/-17.8%, 55.7+/-16.4% and 56.4+/-15.7%, respectively. The mean EDV measured with GSPECT, ECHO and CMRI were 109.2+/-42.45 mL, 127.5+/-42.2 mL, 91.1+/-38.0 mL, respectively. The mean ESV measured with GSPECT, ECHO and CMRI were 54.2+/-41.2 mL, 59.9+/-37.6 mL and 41.8+/-26.9 mL, respectively. The results of linear regression analysis showed very good correlation between LVEF and ESV values derived from GSPECT, ECHO adn CMRI (r=0.91, r=0.92, r=0.97 for LVEF and r=0.86, r=0-91, r=0.91 for ESV, P<0.01). Good correlations were found between EDV values obtained from GSPECT, ECHO and CMRI (r=0.71, r=0.68, r=0.73, P<0.01). Agreement between these techniques in LVEF values was also good, but not in LV volumes, according to Bland-Altman plots.

CONCLUSIONS

This study showed good overall correlations between LVEF, EDV and ESV values derived from GSPECT, ECHO and CMRI. LVEF obtained from any of these three imaging modalities could be used interchangeably. However, care should be taken in comparing LV volumes.

Cinnamomum zeylanicum extract on the radiolabelling of blood constituents and the morphometry of red blood cells: in vitro assay

Effects of Cinnamomum zeylanicum (cinnamon) on the labelling of blood constituents with technetium-99m(99mTc) and on the morphology of red blood cells were studied. Blood samples from Wistar rats were incubated with cinnamon extract for 1 hour or with 0.9% NaCl, as control. Labelling of blood constituents with 99mTc was performed. Plasma (P) and blood cells (BC), soluble (SF-P and SF-BC) and insoluble (IF-P and IF-BC) fractions were separated. The radioactivity in each fraction was counted and the percentage of radioactivity incorporated (%ATI) was calculated. Blood smears were prepared, fixed, stained and the qualitative and quantitative morphological analysis of the red blood cells was evaluated. The data showed that the cinnamon extract decreased significantly (p<0.05) the %ATI on BC, IF-P and IF-BC. No modifications were verified on shape of red blood cells. Cinnamon extracts could alter the labelling of blood constituents with 99mTc, and although our results were obtained with animals, precaution is suggested in interpretations of nuclear medicine examinations involving the labelling of blood constituents in patients who are using cinnamon.

A propolis extract and the labeling of blood constituents with technetium-99m

Since ancient times propolis has been employed for many human purposes because to their favourable properties. Blood constituents labeled with technetium-99m (99mTc) have been used in nuclear medicine procedures. Some authors have reported that synthetic or natural drugs can interfere with the labeling of blood constituents with 99mTc. The aim of this work was to evaluate the action of a propolis extract on the labeling of blood elements with 99mTc. Samples of whole blood of male Wistar rats were incubated in sequence with an aqueous propolis extract at different concentrations, stannous chloride and 99mTc, as sodium pertechnetate. Blood samples were centrifuged to separate plasma and blood cells, soluble and insoluble fractions of plasma and blood cells were also separated after precipitation in trichloroacetic acid solution and centrifugation. The radioactivity was counted and the percentage of incorporated radioactivity (%ATI) for each fraction was calculated. The data obtained showed that the aqueous propolis extract used decreased significantly the %ATI in plasma proteins at higher concentration studied. Results suggest that at high concentration the constituents of this extract could alter the labeling of plasma proteins competing with same binding sites of the 99mTc on the plasma proteins or acting as antioxidant compounds.