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Biomedical subjects

R Castello

Publications and source records attributed to R Castello.

At least 55 records · Page 3Linked to original sources
PubMed1992

Human Lyb-2 homolog CD72 is a marker for progenitor B-cell leukemias.

S-HCL 2 is the prototype antibody of the recently defined CD72 cluster (human Lyb-2). Under nonreducing conditions, S-HCL 2 monoclonal antibody (mAb) precipitates a glycoprotein of 80-86 kDa. Under reducing conditions, a dimer of 43 and 39 kDa, with core proteins of 40 and 36 kDa, is precipitated. CD72 expression in normal and malignant tissues is different from expression of all other previously described human B-cell antigens. In peripheral blood and bone marrow, the antigen appears to be present on all B lymphocytes, with the exception of plasma cells. In tissue, immunohistochemical staining revealed positivity for all known B-cell compartments; however, pulpa macrophages of the spleen and von Kupffer cells exhibited distinct positivity for CD72 also. Among 83 malignant non-Hodgkin's lymphomas examined by immunohistochemistry (alkaline phosphatase anti-alkaline phosphatase technique), all 54 B-cell lymphomas, including precursor B-cell lymphomas, Burkitt's lymphomas, germinal center lymphomas, chronic lymphocytic leukemias, and hairy cell leukemias, were CD72 positive, but no T-cell lymphomas were. Flow cytometry study of more than 80 mainly acute leukemias (52 B-cell leukemias) showed reactivity with S-HCL 2 mAb over the full range of B-cell differentiation. In particular, very early B cells in cytoplasmic Ig (cIg)-negative, CD19-positive pre-pre-B-cell leukemias and hybrid leukemias (mixed myeloid and B-cell type) were consistently positive for CD72 on the cell surface. Therefore, CD72 may become an important marker for progenitor B-cell leukemias.

Antibodies, Monoclonal↗
PubMed1992

Intermittent coronary spasm during graded exercise.

We report a patient with Prinzmetal's angina with nearly normal coronary angiogram who not only developed severe myocardial ischemia during exercise, documented both electrocardiographically (ST elevation) and scintigraphically (with thallium-201), but also did so intermittently as the graded exercise progressed. Diagnostic coronary angiography showed spontaneous focal spasm of the proximal left anterior descending coronary artery. This unique response to exercise in a patient with variant angina suggests that factors other than catecholamine stimulation alone are active and rapidly attenuated in some patients. This phenomenon could be overlooked without appropriate electrocardiographic monitoring.

Angina Pectoris, Variant↗
PubMed1992

Variability in the quantitation of mitral regurgitation by Doppler color flow mapping: comparison of transthoracic and transesophageal studies.

OBJECTIVES: This study was designed to assess the most accurate and reproducible methods to quantitate mitral regurgitation by color flow transthoracic and transesophageal echocardiography. BACKGROUND: Quantitative measurements of mitral regurgitant jets have resulted in an intraobserver and interobserver variability of up to 20%. Few data are available evaluating the various techniques by which mitral regurgitant jets are quantitated. METHODS: Forty patients who underwent cardiac catheterization and both transesophageal and transthoracic echocardiography within 1 week were studied. Two boundaries of the color regurgitant jet area were identified and quantitated: 1) the central aliased core of the regurgitant jet with the mosaic pattern excluding any swirling low velocity flow; and 2) the largest definable area of the regurgitant flow, including low velocity flow considered to be part of the regurgitant jet. RESULTS: The total regurgitant areas obtained by transthoracic and transesophageal studies did not differ (5.7 +/- 4.6 vs. 5.7 +/- 3.7 cm2; p = NS). However, the transesophageal mosaics were significantly larger than those obtained by transthoracic echocardiography (3.6 +/- 3.1 vs. 2.8 +/- 3.4 cm2; p less than 0.01). In transthoracic studies observer variability was higher when the mosaic aspect of the regurgitant jet rather than the total regurgitant area was measured (24 +/- 20 vs. 16 +/- 11%; p less than 0.05). In contrast, in transesophageal studies variability was lower when the mosaic area rather than the total regurgitant area was measured (11 +/- 12% vs. 18 +/- 18%; p less than 0.05). The best correlations with left ventriculography were obtained by using the absolute total regurgitant area (r = 0.72) for transthoracic studies and the mosaic area of the jets (r = 0.87) for transesophageal studies. CONCLUSIONS: Doppler color flow jet areas correlate closely with angiographic results in the evaluation of mitral regurgitation. The total regurgitant area (including the surrounding swirling flow) in transthoracic studies and the aliased core of the regurgitant jet (mosaic) in transesophageal studies appear to be the most accurate and reproducible measurements for evaluating mitral regurgitation.

Cardiac Catheterization↗
PubMed1992

Quantitation of mitral regurgitation by transesophageal echocardiography with Doppler color flow mapping: correlation with cardiac catheterization.

Eighty consecutive patients who underwent both left ventriculography and single-plane transesophageal echocardiography with Doppler color flow mapping were studied to compare the two techniques in the assessment of mitral regurgitation. Only the mosaic aspect of the regurgitant jet was included in the measurements. Values for inter- and intraobserver variability for the maximal regurgitant area measurements were 10 +/- 9% and 9 +/- 8%, respectively. The best correlation between angiography and Doppler color flow imaging was obtained with the maximal regurgitant area (r = 0.90). A maximal regurgitant area less than 3 cm2 predicted mild mitral regurgitation with a sensitivity of 96%, specificity of 100% and a predictive accuracy of 98%, whereas a maximal regurgitant area greater than 6 cm2 predicted severe mitral regurgitation with a sensitivity of 91%, a specificity of 100% and a predictive accuracy of 98%. A strong, although inferior, correlation was found for the maximal regurgitant area/left atrial area ratio (r = 0.81). A ratio less than 20% predicted mild mitral regurgitation with 94% accuracy, whereas a ratio greater than 35% predicted severe mitral regurgitation with 85% accuracy. Thus, single-plane transesophageal echocardiography with Doppler color flow mapping is an exquisitely sensitive technique for the diagnosis of mitral regurgitation. Minimal degrees of mitral regurgitation can be detected in approximately 62% of patients in whom no mitral regurgitation is detected by angiography. The mosaic maximal regurgitant area is a simple and easily obtainable Doppler echocardiographic index that provides an accurate estimation of mitral regurgitation severity.

Cardiac Catheterization↗
PubMed1992

Dipyridamole echocardiography.

Intravenous dipyridamole is a potent coronary vasodilator that has been extensively investigated over the past several years in the noninvasive assessment of patients with suspected coronary artery disease when exercise cannot be performed or is suboptimal. As an alternative to exercise studies, dipyridamole has been used in combination with different cardiac imaging techniques such as echocardiography, thallium scintigraphy, and radionuclide ventriculography. Extensive experience has been obtained with dipyridamole thallium-201 imaging for coronary artery disease screening, risk stratification, and prognosis after an acute coronary event. However, experience with the use of dipyridamole in combination with two-dimensional echocardiography has been limited. Dipyridamole increases coronary blood flow in nondiseased coronary vessels relative to coronary vessels with significant luminal narrowings. These provide the basis for detecting regional differences in flow by using different cardiac imaging techniques. Two-dimensional echocardiography would show regional wall-motion abnormalities in response to those regional differences in coronary blood flow. In this article, the most commonly used protocols, safety, and practicability of dipyridamole echocardiography are reviewed. As an alternative to exercise, dipyridamole echocardiography shares all the indications of a standard exercise test. Clinical applications of dipyridamole echocardiography include coronary artery disease screening, suspected coronary artery spasm, postmyocardial infarction risk stratification, evaluation of percutaneous transluminal coronary angioplasty results, and prognosis following an acute coronary event. Compared to conventional (ECG) exercise testing, dipyridamole echocardiography appears to be equally sensitive but more specific. Compared to atrial pacing, dipyridamole provokes ischemia at a lower rate pressure product and results in a greater ST segment depression suggesting that dipyridamole induces more profound myocardial ischemia than atrial pacing. Dipyridamole thallium and exercise thallium have shown to be equally sensitive and specific in the assessment of coronary artery disease. High dose dipyridamole echocardiography appeared to be equally sensitive and more specific. Experimental studies have demonstrated that dobutamine appears to be a more powerful pharmacological agent in inducing wall-motion abnormalities. Dipyridamole echocardiography as compared to stress echocardiography offers the advantage of obtaining better quality postintervention images. With regard to sensitivity and for coronary artery disease diagnosis, both techniques appear to render similar results. Although further studies are needed, the available data indicates that cardiac ultrasound imaging prior to and following the intravenous administration of dipyridamole may be an attractive alternative to thallium perfusion imaging in the clinical setting, particularly when radionuclide capabilities are not present.

Angioplasty, Balloon, Coronary↗
PubMed1991

Comparison of transthoracic and transesophageal echocardiography for assessment of left-sided valvular regurgitation.

To compare transthoracic and transesophageal echocardiography in the clinical assessment of left-sided valvular regurgitation, 118 patients who underwent both transesophageal and transthoracic echocardiographic studies within a 24-hour period were included in this study. Presence or absence of aortic regurgitation was identified concordantly by both techniques in 93 patients (79%). Complete agreement between both techniques was found in 88 patients (75%). Presence or absence of mitral regurgitation was identified concordantly by both techniques in 89 patients (75%). Complete agreement in grade was found in only 74 patients (63%). Twenty-nine patients (25%) had mitral regurgitation detected by transesophageal echocardiography, but not by transthoracic echocardiography. Four of these patients (14%) had significant (2 to 3+) mitral regurgitation. Differences between transesophageal and transthoracic echocardiography do not appear to be clinically important in patients with aortic regurgitation. In mitral regurgitation, significant differences exist between these 2 techniques, with transesophageal echocardiography being much more sensitive.

Aortic Valve↗
PubMed1991

Atrial septal aneurysm and stroke: a transesophageal echocardiographic study.

The prevalence and morphologic characteristics of atrial septal aneurysms identified by transesophageal echocardiography in 410 consecutive patients are described. Two groups of patients were compared: Group I consisted of 133 patients referred for evaluation of the potential source of an embolus and Group II consisted of 277 patients referred for other reasons. An atrial septal aneurysm was diagnosed by transesophageal echocardiography in 32 (8%) of the 410 patients. Surface echocardiography identified only 12 of these aneurysms. Atrial septal aneurysm was significantly more common in patients with stroke (20 [15%] of 133 vs. 12 [4%] of 277) (p less than 0.05); right to left shunting at the atrial level was demonstrated in 70% of patients in Group I and 75% of patients in Group II by saline contrast echocardiography. Four patients in Group I had an atrial septal defect with additional left to right flow. There was no difference between the two groups in aneurysm base width, total excursion or left atrial or right atrial excursion. However, Group I patients had a thinner atrial septal aneurysm than did Group II patients. It is concluded that an atrial septal aneurysm occurs commonly in patients with unexplained stroke, is more frequently detected by transesophageal echocardiography than by surface echocardiography and is usually associated with right to left atrial shunting. Treatment (anticoagulant therapy vs. surgery) of atrial septal aneurysm identified in stroke patients can be determined only by long-term follow-up studies.

Adult↗
PubMed1991

Attenuation of myocardial ischemia during coronary occlusion by ultrashort-acting beta adrenergic blockade.

To assess the effect of the ultrashort-acting beta blocker esmolol on ischemia induced by acute coronary occlusion, we studied 16 patients undergoing coronary angioplasty. Doppler echocardiography and ECG monitoring were performed continuously before, during, and after balloon occlusion in the drug-free state and during esmolol infusion. Fourteen of the 16 patients had ST segment elevation during balloon inflation. However, maximal ST segment elevation (2.1 +/- 1.5 mm vs 1.7 +/- 1.3 mm, p less than 0.001) and duration of ST segment elevation (68 +/- 20 seconds vs 54 +/- 19 seconds, p less than 0.05) were both significantly reduced during esmolol infusion. Furthermore, the decrease in ejection fraction seen during drug-free balloon occlusions was significantly blunted during esmolol infusion. In the baseline state ejection fraction decreased from 55% to 38% (p less than 0.05) during coronary occlusion compared with a decrease from 52% to 49% (p = NS) during esmolol infusion. In addition, esmolol appeared to delay the onset of segmental wall motion abnormalities after coronary occlusion, occurring at a mean of 40 seconds after balloon inflation versus a mean of 31 seconds in the absence of beta blockade (p less than 0.05). Thus the use of ultrashort-acting beta blockade appears to diminish the extent and delay the onset of myocardial ischemia during acute coronary occlusion.

Adrenergic beta-Antagonists↗
PubMed1991

The effects of high (sodium meglumine diatrizoate, Renografin-76) and low osmolar (sodium meglumine ioxaglate, Hexabrix) radiographic contrast media on diastolic function during left ventriculography in patients.

Although a majority of studies indicate superior hemodynamic and clinical profiles of low osmolar compared with high osmolar contrast media, the effect of these agents on diastolic left ventricular function has not been examined. We prospectively examined hemodynamic, electrocardiographic, and echocardiographic indices of left ventricular function in patients undergoing contrast ventriculography with a high osmolar, ionic, monomeric contrast, diatrizoate (Renografin-76) compared with a low osmolar, ionic, dimeric contrast, ioxaglate (Hexabrix). Thirty patients were randomized to each group. There were no clinical differences between the two groups. The decrease in systemic pressures was significantly greater with diatrizoate after left ventriculography (-38.5 +/- 3.5 versus -18.2 +/- 2.3, p less than 0.001) and selective left coronary angiography (-29.5 +/- 2.4 versus -17.4 +/- 2.6, p less than 0.001). In addition, left ventricular end-diastolic pressure increased significantly more with diatrizoate (7.3 +/- 0.9 versus 2.7 +/- 0.8 mm Hg for ioxaglate, p less than 0.001). QT interval prolongation occurred in both patient groups. Diatrizoate decreased systemic vascular resistance, and increased cardiac output and left ventricular ejection fraction more than ioxaglate, while simultaneously increasing left ventricular end-diastolic volume and altering the peak atrial filling velocity. Negative dp/dt (p less than 0.05), but not Tau, computed by the logarithmic or derivative methods, was reduced by diatrizoate. These data indicate that significant alteration of diastolic filling patterns occurs with high osmolar compared with low osmolar contrast agents. Although the clinical significance of this observation is currently unknown, these data further support the reported hemodynamic superiority of the low osmolar, dimeric contrast agent ioxaglate during contrast angiography.

Contrast Media↗
PubMed1991

Effect of mitral regurgitation on pulmonary venous velocities derived from transesophageal echocardiography color-guided pulsed Doppler imaging.

The effect of mitral regurgitation on pulmonary venous flow velocity was studied in 66 patients undergoing transesophageal echocardiography. Nine patients were studied intraoperatively before and after surgery, so that 75 pulmonary venous flow tracings were analyzed. Fifty-four patients had no significant (0 to 1+) mitral regurgitation and 21 had significant (2 to 3+) mitral regurgitation. Comparison of both groups revealed significant differences in the pulmonary venous flow pattern. In patients with no significant mitral regurgitation, the peak systolic velocity was higher (55 +/- 16 vs. -4 +/- 16 cm/s; p less than 0.0001) and the peak diastolic velocity was lower (43 +/- 13 vs. 59 +/- 17 cm/s; p less than 0.01) when compared with values in patients with significant mitral regurgitation. Consequently, the peak systolic/diastolic velocity ratio was significantly higher in the patients without significant mitral regurgitation (1.4 +/- 0.5 vs. 0.4 +/- 1.3; p less than 0.0001). The same trend was noted with respect to the systolic and diastolic velocity integrals. As the degree of mitral regurgitation increased, the peak diastolic velocity and diastolic velocity integral increased, whereas the peak systolic velocity and systolic velocity integral decreased. In patients with severe mitral regurgitation, the systolic flow became reversed (retrograde). The sensitivity of reversed systolic flow for severe mitral regurgitation was 90% (9 of 10), the specificity was 100% (65 of 65), the positive predictive value was 100% (9 of 9), the negative predictive value was 98% (65 of 66) and the predictive accuracy was 99% (74 of 75).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗
PubMed1991

Evaluation of pulmonary venous flow by transesophageal echocardiography in subjects with a normal heart: comparison with transthoracic echocardiography.

Nineteen normal subjects and five patients with atrial fibrillation underwent transesophageal and transthoracic echocardiographic studies to evaluate the normal pulmonary venous flow pattern, compare right and left pulmonary venous flow and assess the effect of sample volume location on pulmonary venous flow velocities. Best quality tracings were obtained by transesophageal echocardiography. Anterograde flow during systole and diastole was observed in all patients by both techniques. Reversed flow during atrial contraction was observed with transesophageal echocardiography in 18 of the 19 subjects in normal sinus rhythm, but in only 7 subjects with transthoracic echocardiography. Two forward peaks during ventricular systole were clearly identified in 14 subjects (73%) with transesophageal echocardiography, but in none with the transthoracic technique. The early systolic wave immediately followed the reversed flow during atrial contraction and was strongly related to the timing of atrial contraction (r = 0.78; p less than 0.001), but not to the timing of ventricular contraction, and appeared to be secondary to atrial relaxation. Conversely, the late systolic wave was temporally related to ventricular ejection (r = 0.66; p less than 0.001), peaking 100 ms before the end of the aortic valve closure and was unrelated to atrial contraction time. Quantitatively, significantly higher peak systolic flow velocities were obtained in the left upper pulmonary vein compared with the right upper pulmonary vein (60 +/- 17 vs. 52 +/- 15 cm/s; p less than 0.05) and by transesophageal echocardiography compared with transthoracic studies (60 +/- 17 vs. 50 +/- 14 cm/s; p less than 0.05). Increasing depth of interrogation beyond 1 cm from the vein orifice resulted in a significant decrease in the number of interpretable tracings.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Evaluation of mitral regurgitation by Doppler echocardiography.

The diagnosis and assessment of mitral regurgitation has been one of the main challenges for cardiac ultrasound. Imaging techniques (M-mode and two-dimensional echocardiography) provide direct morphologic and etiologic information of the evaluation of patients with suspected mitral regurgitation. The advent of cardiac Doppler increased tremendously the ability to evaluate mitral regurgitation noninvasively. Continuous-wave and pulsed Doppler have been found to be sensitive and specific in the detection of mitral regurgitation. The introduction of color flow Doppler simplified enormously the assessment of patients with suspected mitral regurgitation. The maximal regurgitant area and maximal regurgitant area corrected for left atrial size have become the most commonly used parameters to evaluate mitral regurgitation by color flow Doppler in the clinical setting. However, the color regurgitant jet area is highly dependent on anatomical, hemodynamic, and equipment factors. A new method, based on the proximal isovelocity surface area, is being evaluated and appears to be relatively independent of equipment factors. Transesophageal echocardiography has been shown to be exquisitely sensitive in the detection of mitral regurgitation. Quantitation of mitral regurgitation by transesophageal echocardiography is currently based on the maximal regurgitant area and this parameter appears to correlate closely with the angiographic degree of mitral regurgitation. Pulmonary venous flow analysis had been used in conjunction with color flow mapping for the evaluation of mitral regurgitation by transesophageal echocardiography. The presence of reversed systolic flow has been shown to be sensitive and specific for the diagnosis of severe mitral regurgitation. Patients with clinically difficult surface studies, flail mitral valve leaflets, and prosthetic mitral valve are best evaluated by the transesophageal approach with interrogation of pulmonary venous flow.

Blood Flow Velocity↗
PubMed1990

Prevalence and clinical implications of atrial spontaneous contrast in patients undergoing transesophageal echocardiography.

The prevalence of atrial spontaneous contrast was evaluated in 150 consecutive patients undergoing transesophageal echocardiography. Spontaneous contrast was observed in 29 patients (19%). It was seen in the left atrium in 24 patients, in the right atrium in 4 patients and in both atria in 1 patient. Spontaneous atrial contrast was not seen in the absence of an associated cardiac abnormality. Univariate analysis showed a significant relation between the presence of spontaneous contrast and significant mitral regurgitation (p less than 0.05), the presence of mitral valve prostheses (p less than 0.001), atrial fibrillation (p less than 0.0001) and left atrial size (p less than 0.001). Multivariate analysis showed that the presence of atrial fibrillation, prosthetic mitral valve and atrial size were independent factors for the presence of spontaneous contrast. However, of the 29 patients with spontaneous contrast, 13 (45%) were in sinus rhythm and in only 4 (16%) was the left atrial size greater than 60 mm. Left atrial thrombus was detected in 9 of the 150 patients. Although spontaneous contrast was noted in 5 (55%) patients with left atrial thrombus and in only 20 (14%) patients without left atrial thrombus (p less than 0.001), none of the 3 patients who had right atrial thrombus had spontaneous contrast in that chamber. Overall, 7 (58%) of the 12 patients with right or left atrial thrombi had no evidence of spontaneous contrast. Multivariate analysis showed that atrial fibrillation was the only independent clinical predictor of left atrial thrombus. Thus, spontaneous echocardiographic contrast is a common phenomenon observed in approximately 20% of the patients undergoing transesophageal echocardiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Spontaneous echocardiographic contrast in the descending aorta.

The visualization of echocardiographic spontaneous contrast is a common phenomenon in patients undergoing transesophageal echocardiographic studies. Its pathophysiology is not well understood, but it has been related to the presence of a low flow state in the cardiac chambers. We report the presence of spontaneous contrast in the descending aorta of four patients, a location not previously described in the absence of aortic dissection. In two patients, spontaneous contrast was noted in both the left atrium and the descending aorta. In one patient with moderate left ventricular dysfunction, spontaneous contrast was noted in the descending aorta and in the left ventricle. In the remaining case, no cardiac or aortic abnormalities were observed and this represents the first time that spontaneous contrast has been identified in a patient with an echocardiographically normal heart. The occurrence of spontaneous contrast has been considered an abnormal echocardiographic finding, since it has always been described in patients with clinical symptoms and cardiac abnormalities. The fact that spontaneous contrast can be visualized in patients with very mild structural cardiac abnormalities or none at all, warrants further investigation, especially when therapeutic or prognostic implications are considered.

Aged↗
PubMed1990

Diastolic function in patients undergoing coronary angioplasty: influence of degree of revascularization.

To assess the early effects of successful coronary angioplasty on Doppler-derived left ventricular filling patterns and the significance of the extent of revascularization on these variables, 31 patients undergoing coronary angioplasty were examined within 24 h before and after the revascularization procedure. After angioplasty, the peak early to late velocity ratio increased from 0.89 +/- 0.2 to 1.05 +/- 0.3 (p less than 0.0001) and the one-third filling fraction increased from 42 +/- 10% to 48 +/- 10% (p less than 0.0001). The percent atrial contribution to filling decreased from 45 +/- 7% to 41 +/- 8% (p less than 0.01), and the pressure half-time and the isovolumetric relaxation time shortened from 55 +/- 15 to 43 +/- 13 ms (p less than 0.001) and from 100 +/- 14 to 82 +/- 17 ms (p less than 0.0001), respectively. When comparing patients with complete (n = 23) and incomplete (n = 8) revascularization, the same changes in the Doppler variables were observed. However, the mean rate of acceleration of early filling increased significantly after angioplasty only in those patients with complete revascularization. These data indicate that the left ventricular diastolic filling pattern is modified significantly as early as 24 h after successful coronary angioplasty. Improvement in impaired relaxation appears to be the most likely explanation for these changes, although increased myocardial stiffness in patients with incomplete revascularization is an alternative hypothesis.

Aged↗