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We examined cross-species transferability and usefulness of six nuclear microsatellite markers developed in consubgeneric eastern white pine (Pinus strobus) with regard to ecologically and commercially important Mexican white pine species of conservation genetics concern: Pinus chiapensis (Mart.) Andresen, P. flexilis James, P. strobiformis Engelm., P. ayacahuite Ehrenb. Ex Schltdl, and P. ayacahuite var. veitchii (Roezl) G.R. Shaw. Four to six microsatellite loci were found to be polymorphic in different species, with moderate to high informativeness in a relatively small number of samples (PIC/HE=0.25-0.93). This successful transfer sidesteps the time- and resource-consuming development of species-specific microsatellite markers, and will facilitate population and conservation genetic studies and genetic resource management of the less studied Mexican white pines.

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OBJECTIVE: Lymphangiomas are lesions usually presenting during childhood and are located mainly in the head and neck region; less than 5% are intraabdominal. Lymphangiomatosis is the term used for multifocal or diffuse lymphangiomas. METHODS AND RESULTS: We report the case of a mesenteric lymphangiomatosis presenting as an acute abdomen in a 19-year-old man, review the literature and discuss the clinical management of these patients. CONCLUSIONS: Prognosis and treatment of these lesions depends of its site of origin and extension, being complete surgical excision the optimal treatment.

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OBJECTIVE: Sulfur colloid 99mTc-SC, the radiopharmaceutical of choice for solid gastric emptying studies, is not available in our country. It has led us to assess the solid binding stability of seven alternative radiopharmaceuticals that could present adequate fixation to it a priori. MATERIALS AND METHOD: The stability of labelled solid food with seven colloidal 99mTc-radiopharmaceuticals of different sizes and nature (MAA, tin colloid, rhenium sulphide macrocolloid, albumin microcolloid, sulfur nanocolloid, albumin nanocolloid and rhenium sulfur nanocolloid) has been studied by measuring their dissociated activity after two hours digestion in simulated gastric fluid (kept 120' in agitation, in HCl 0.1 M at 37). The survey also assesses radiopharmaceutical labelling stability after two hours digestion in identical conditions by measuring their radiochemical purity in ITLC. RESULTS: In these conditions, MAA, rhenium sulphide macrocolloid, albumin microcolloid and albumin microcolloid present the best behaviour, with an activity linked to food over 90 % of the previously fixed activity. CONCLUSIONS: According to the results, there is no relationship between the radiopharmaceutical size and nature and the stability of its binding to the solid food. Because rhenium sulphide macrocolloid is no longer manufactured and the other three radiopharmaceuticals which have a binding stability to the solid food over 90 % do not include digestive explorations amongst their indications, nowadays, there is a serious legal limitation to carry out this type of studies in our country.

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BACKGROUND: beta-Blockers and ACE inhibitors reduce early mortality when either one is started in the first hours after myocardial infarction (MI). Considering the close correlation between morphological changes and prognosis, we aimed to investigate whether the benefit of both beta-blockers and ACE inhibitors might reside in a similar protective effect on infarct size or ventricular volume. METHODS AND RESULTS: In a randomized, double-blind comparison between early treatment with captopril or atenolol in 121 patients with acute anterior MI, both drugs showed a similar reduction in mean blood pressure. However, only the atenolol-treated patients showed a significant early reduction in heart rate. Infarct size, obtained from the perfusion defect in resting single photon emission imaging, was higher in captopril-treated patients than in atenolol-treated patients: 29.8+/-12% versus 20.8+/-12% (P:<0.01) by polar map and 28.3+/-13% versus 20.0+/-13% (P:<0.01) by tomography. Changes from baseline to 1 week and to 3 months in ventricular end-diastolic volume, assessed by echocardiography, were as follows: 58+/-14 versus 64+/-19 (P<0.05) and 65+/-21 mL/m(2) (P<0.05), respectively, with captopril, and 58+/-18 versus 64+/-18 (P<0.05) and 69+/-30 mL/m(2) (P<0.05), respectively, with atenolol. Neither group showed significant changes in end-systolic volume. Among patients with perfusion defect >18% (n=51), those treated with atenolol showed a significant increase of end-systolic and end-diastolic ventricular volumes, whereas captopril-treated patients did not. CONCLUSIONS: Although early treatment with atenolol or captopril results in similar overall short- and medium-term preservation of ventricular function and volumes, in patients with larger infarctions, a beta-blocker alone does not adequately protect myocardium from ventricular dilatation.

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UNLABELLED: The presence of affected locoregional lymph nodes should be considered as one of the most important prognostic factors of breast cancer. At present, the clinician is conditioned by an absolute lack of an efficient methodology to evaluate the possible invasion of the axillary lymph nodes, which if negative, would make it possible to avoid surgical excision. In this study, we will evaluate the use of the 99mTc-MIBI scintigraphy in the pre-surgical diagnosis of axillary lymph node invasion and will analyze the relationship between the 99mTc-MIBI uptake and the number of lymph nodes affected. MATERIAL AND METHODS: 84 patients diagnosed of breast cancer were analyzed in this study. All of them underwent a 99mTc-MIBI scintigraphy, and the tumor/background ratio was determined semiquantitively for each image. The axillary lymph node invasion was determined following surgery. RESULTS: The sensitivity of the breast scintigraphy with 99mTc-MIBI for detection of lymph node invasion is 36% and the specificity is 100%. The positive predictive value is 100% and the negative one 48%. In the current study, we failed to detect correlation between the intensity of 99mTc-MIBI uptake in the primary tumor and the number of affected axillary lymph nodes. CONCLUSION: 99mTc-MIBI breast scintigraphy can provide complementary information for the presurgical diagnosis of breast cancer axillary lymph node invasion. 99mTc-MIBI breast scintigraphy shows high specificity and a high predictive value.

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OBJECTIVE: Scintigraphy studies with (99m)Tc-MIBI are widely used in the diagnosis of non-invasive breast cancer and their results have been verified by many studies. However, the scintigraphic technique produces erroneous false negative and positive results. This study aims to verify how the different characteristics of the uptake of (99m)Tc-MIBI (intensity, size, morphology, etc.) can help to increase sensitivity and specificity of breast scintigraphy. MATERIALS AND METHODS: We have studied 201 patients (84 breast cancer and 117 benign lesions). All of them underwent a breast scintigraphy with (99m)Tc-MIBI and anatomopathological study. A semiquantitative analysis (by T/F indexes) and visual study were performed in the lesions that presented radiodrug uptake. RESULTS: Eleven false positive results and 8 false negative results were obtained in the study of the 201 patients. The analysis of the T/F indexes did not demonstrate any significant differences between the benign and malignant lesions (p>0,05). There is a statistically significant correlation (p<0.05) between the tracer uptake morphology and the AP diagnosis and between the localization of the lesion in a breast quadrant and the uptake intensity. CONCLUSIONS: Quantification of (99m)Tc-MIBI uptake by T/F indexes does not provide any conclusive data on the lesion's malignancy, however, a more detailed analysis of the characteristics of the tracer uptake would permit us to make the correct diagnosis and would reduce the false positive and negative results of this technique.

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UNLABELLED: (99m)Tc-MIBI has been proposed as an imaging diagnostic method in a large variety of human malignant tumors. At present, the mechanism by which (99m)Tc-MIBI is uptaken and concentrated by the malignant cells is not totally known. Some mammary neoplasms do not show any uptake of (99m)Tc-MIBI. This study aims to determine if there is any correlation between the uptake of (99m)Tc-MIBI by the tumor and the different histopathological parameters involved in tumoral aggressiveness. To do so, we have studied 100 patients with breast cancer. All of them underwent a breast scintimammography with (99m)Tc-MIBI with semiquantitative analysis by means of a tumor-to-background ratio calculated in every projection. After surgery, an experienced pathologist determined tumor size, axillary lymph node metastases, histological grade (Scarff Bloom Richardson) (SCBR), nuclear grade, mitotic index, presence of cellular atypia and estrogen and progesterone receptor expression. RESULTS: A statistically significant correlation (p < 0.005) has been found between tumor-to-background (T/B) ratios of (99m)Tc-MIBI uptake and tumor SCBR histological grade. A correlation between (99m)Tc-MIBI uptake and the mitotic index, cellular atypia and nuclear grade has also been found. No correlation was found in our study with tumor size, hormone receptor expression or axillary lymph node metastases. CONCLUSIONS: (99m)Tc-MIBI uptake in breast cancer is correlated with the tumoral differentiation grade: the smaller the tumoral cellular differentiation (greater aggressiveness), the greater the uptake. On the other hand, no correlation was found between the uptake of (99m)Tc-MIBI and the classical pathological parameters that define tumoral aggressiveness, such as size and axillary lymph node metastasis.

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UNLABELLED: Breast scintimammography with 99mTc-MIBI has proven to be a useful complement to mammography in the diagnosis of breast cancer in the female population. Although the mammography, along with a physical examination, is the backbone of breast cancer diagnosis, there are groups of patients in whom the mammography has an even lower specificity. OBJECTIVE: Our study has aimed to assess the usefulness of breast 99mTc-MIBI scintimammography in those situations in which the mammography was indeterminate, such as, in dense breasts, young females or breasts with architectural distortion after surgery or radiation therapy. MATERIALS AND METHODS: We studied 109 females with mammographically dense breasts, 8 young females under 30 and 24 patients who had undergone previous surgery or radiation therapy. All cases were studied to rule out breast cancer. Final diagnosis was established with excisional biopsy. RESULTS: In dense breasts MIBI scintimammography sensitivity was 88% and the mammography one 81%. MIBI scintimammography specificity was 90% and the mammography 28%. In young females MIBI scintimammography sensitivity was 100% and the mammography 50%, MIBI scintimammography specificity 100% and the mammography 20%. In previous surgery, MIBI scintimammography sensitivity was 80% and the mammography 80%, MIBI scintimammography specificity 100% and the mammography 42%. CONCLUSION: Breast scintimammography with 99mTc-MIBI is an excellent diagnostic technique with high specificity. Undoubtedly it is complementary to mammography in those cases where mammography has major limitations such as dense breasts, young females and breasts with severe scarring after surgery or radiation therapy.

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Although the role of nuclear cardiology is currently well consolidated, the addition of new radiotracers and modern techniques makes it necessary to continuously update the requirements, equipment and clinical applications of these isotopic tests. The characteristics of the radioisotopic drugs and examinations presently used are explained in the first part of this text. In the second, the indications of them in diagnostic and prognostic evaluation of the different coronary diseases are presented.

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INTRODUCTION AND OBJECTIVES: The aim of this study is to analyze the impact of clinical data and the interhospital agreement in the interpretation of myocardial perfusion single photon emission tomography (SPECT) images and polar mapping. METHODS: 150 patients from 5 hospitals were studied. Each center contributed with tomographic images and polar maps of 99mTc-tetrofosmin exercise SPECT and clinical reports of 30 patients. Thus, 300 images (150 of tomographic images and 150 of polar maps) were interpreted by each center without knowledge of clinical data of the patient ("blinded" report). RESULTS: 90 (60%) out of 150 patients had a coronary stenosis > or = 50%. Sensitivity and specificity of "non blinded" report were 91% and 86%, respectively. Sensitivity determined by majority decision (three or more centers) was 82% for tomographic images and 83% for polar maps (p = 0.002 and p = 0.03, respectively, regarding the "non-blinded" report). Specificity was 88% for tomographic images and 79% for polar map (p = 0.05 with respect to tomographic images). Interhospital agreement was good not only for tomographic images (kappa: 0.625) but for polar maps (kappa: 0.7) as well. CONCLUSIONS: Sensitivity of clinical or "non blinded" report of myocardial perfusion SPECT is significantly higher than the "blinded" report. Specificity of the "blinded" report of polar mapping is lower than that of tomographic images. A good interhospital agreement in interpretation of both types of images was observed.

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Although the role of nuclear cardiology is currently well consolidated, the addition of new radiotracers and modern techniques prompt us to permanently update the requirements, equipment and clinical applications of these isotopic tests. Radioisotopic drugs, instrumentation and characteristics of radionuclide tests that are presently used are explained in the first part of this text. In the second part, diagnostic and prognostic indications of these tests are presented in detail.

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BACKGROUND: Dual pacing stimulation improves symptoms and reduces intraventricular pressure gradient in obstructive hypertrophic cardiomyopathy. The mechanisms proposed for these effects are a change in ventricular contraction sequence, a paradoxical movement of the interventricular septum and a reduction in ventricular contractility. However, dual chambers pacing stimulation effects on systolic and diastolic function are unknown, and the study of this is the aim of this work. PATIENTS AND METHODS: We performed a radionuclide ventriculography in 10 patients with obstructive hypertrophic cardiomyopathy at 2 days and 1 and 6 months after placing a dual chamber pacemaker. The phase images, ventricular volumes, left ventricular ejection fraction and segmentary contractility were evaluated. Diastolic maximum peak-filling-rate and time to-peak-filling-rate were also studied. RESULTS: In DDD pacing stimulation, parametric phase images show a reversal up-down contraction sequence starting from the apical segment. At 6 months radionuclide ventriculography, a reduction in ejection fraction was found (60.9 +/- 12 vs 73.4 +/- 9.1; p < 0.05) which was attributed to apical, apical-septum and mainly basal-septum segmentary contraction decrease. A paradoxical mid-systolic septum movement was also found during DDD stimulation. No differences on diastolic parameters were noted. CONCLUSION: During dual chamber stimulation, a reversal ventricular contraction sequence, a paradoxical septum movement, hypokinesis of the septal ventricular segments and a reduction on left ventricular ejection fraction was observed.

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This study was designed to evaluate the role of endogenous opioids in neurally-mediated syncope. Head-up tilt test was performed on 35 patients with syncope of unknown origin. Plasma beta-endorphin was measured (1) at baseline, (2) at the end of tilt test or at time of syncope, (3) 15 min before isoproterenol-test, (4) at the end of the isoproterenol-test or at time of syncope. Subjects with a positive tilt testing showed a larger rise in plasma beta-endorphin concentrations at time of syncope (baseline 13.7+/-8.0 vs. syncope 41.4+/-26.4 pmol l(-1); P<0.01). On the contrary, patients with a positive isoproterenol-test showed no rise in plasma beta-endorphin levels (baseline 7.9+/-3.6 vs. syncope 7.4+/-2.7 pmol l(-1); P=ns). Patients with a passive negative tilt test (baseline 6.7+/-2.8 vs. end of test 7.0+/-3.3 pmol l(-1); P=ns) and negative isoproterenol tilt test (baseline 7.4+/-3.8 vs. end of test 8.1+/-3.4 pmol l(-1); P=ns) showed no changes in beta-endorphin concentrations. To further examine the efficacy of i.v. naloxone to prevent syncope, 10 patients were randomized to naloxone (0.02 mg/kg) or placebo. Second head-up tilt testing was negative in 1/5 patients with naloxone and in 2/5 patients with placebo. We conclude that, (1) endogenous opioids seem to be involved in vasovagal syncope induced by baseline head-up tilt test, (2) changes in plasma beta-endorphin concentrations show significant differences between patients who have isoproterenol-dependent and isoproterenol-independent syncope, this finding might occur in the setting of different pathophysiologic mechanisms, and (3) intravenous naloxone at a dose of 0.02 mg/kg was not superior to placebo in order to prevent positive responses to baseline tilt test.

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BACKGROUND: Physiological hormone adaptation to a prolonged and submaximum exercise is not well known. The present study was designed to evaluate changes in plasma levels of beta-endorphin and ACTH before and after a 4 hour pedestrian race. SUBJECTS AND METHOD: Fourteen amateur athletes enrolled in a 4-hour race were studied. Beta-endorphin and ACTH determinations were performed (double antibody IRMA) 10 minutes before and after the race. Simultaneously, heart rate and blood pressure were registered. RESULTS: After the race beta-endorphin level increased 2.8 times with respect to basal values (X [DE]) (42.2 [20,5] VS 14.9 [5.1] pM/I; p < 0.0001), and ACTH level increased 3.5 times (110.8 [72.9] vs 31.4 [14.2] pg/ml; p < 0.0001). There was a positive correlation between the increase of beta-endorphin and ACTH and the distance covered by each athlete (r = 0.617, p < 0.001 and r = 0.533, p < 0.05, respectively), and between the increase of basal and post-race values of both hormones (r = 0.935; p < 0.001). CONCLUSION: Prolonged and submaximum exercise provokes beta-endorphin and ACTH increase, and is related to the amount of performed exercise. There is a positive correlation between the increase of plasma levels of both hormones. Therefore, exercise amount could be one of the main modulator mechanism of beta-endorphin and ACTH release.

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INTRODUCTION AND OBJECTIVES: After the ischemia-reperfusion process in extracorporeal cardiac surgery there are, among several phenomena, some reperfusion arrhythmias which are influenced by a varied series of mechanisms. These arrhythmias have been related to the release of oxygen-derived free radicals during the first moments of reperfusion. Thus, a previous administration of free-radical scavengers might be beneficial, among which captopril has been included with good results in human studies in vitro and in animals in vivo. The aim of this study was to evaluate the influence of pretreatment with captopril on the prevention of reperfusion arrhythmias in patients undergoing valvular cardiac surgery. METHODS: 30 patients were randomly allocated to pretreatment with either captopril (CTP group, n = 15) or without captopril (CON group, n = 15). Exclusion criteria (left ventricular ejection fraction < 40%, evidence of angiographic coronary disease, prior myocardial infarction and preoperatory myocardial infarction). The dose of captopril administered was 12.5 mg every 8 hours orally, from 24 hours before surgery. A Holter register was used to analyze the ventricular arrhythmias (extrasystoles, salvos, tachycardia and fibrillation) during the first hour of reperfusion. The need for cardioversion was examined and the number of shocks needed. These events were related to changes in blood analyses from coronary sinus samples to determine creatine phosphokinase, activity of the angiotensin converting enzyme and cyclic adenosine monophosphate, before aortic clamping and after the heart was rewarmed. RESULTS: No significant differences were found in the number of ventricular arrhythmias. 60% of the patients with captopril and only 40% of the patients without it (non significant) had spontaneous defibrillation without electric shock; in those cases in which it was necessary, the number of shocks was less in the captopril group (p < 0.05). Excepting the significant correlation (p < 0.01) that we have found between ventricular fibrillation and the cyclic adenosine monophosphate increase, there is no significant correlation between the other arrhythmias and the analytical data studied. CONCLUSIONS: These data suggest that captopril, given before cardiac surgery, has little or no protector effect on reperfusion ventricular arrhythmias in extracorporeal cardiac surgery, though in patients treated with captopril there is a greater possibility of spontaneous defibrillation and fewer shocks necessary for defibrillation, without negative effects.

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OBJECTIVES: To follow the left ventricular systolic function changes as assessed by global and regional ejection fraction during the first year of evolution after anterior myocardial infarction, as well as to analyse how the most relevant clinical and angio-graphic parameters influence them. MATERIALS AND METHODS: Sixty-six consecutive patients with a first infarction of anterior location, completed 1 year of follow-up with radionuclide ventriculography, T1-SPECT after exercise or dypiridamole and cardiac catheterization before discharge; radionuclide ventriculography was repeated 6 and 12 months later. Twenty-five patients underwent revascularization procedures at the time of predischarge, 16 using successful percutaneous angioplasty of the left anterior descending artery and 9 using aorto-coronary graft surgery. Dilated patients were controlled, from an angiographic point, of view 6 months after PTCA. RESULTS: Predischarge global EF (42.9 +/- 12.6) increased significantly between the 6-month (46.9 +/- 12.8; p < 0.001) and 12-month (47.6 +/- 12; p < 0.001) studies. Differences in these two last studies were minor and had no statistical significance. A significant increase was present in revascularized or medically treated patients; i.e. those who underwent thrombolytic therapy or conventional treatment at admittance as well as mono or multivessel disease patients. No significant differences were detected in the mean ejection fraction in patients without residual stenosis in the infarct-related artery (48.1 +/- 13.3 vs 50 +/- 12.6; NS) or those presenting a pre-discharge ejection fraction > or = 45% (53.5 +/- 7.5 vs 55.1 +/- 3.3; NS). Among different variables tested, predischarge global ejection fraction (negative coefficient) and, to a lesser extent, percutaneous angioplasty were independent predictors of a significant increase of ejection fraction during follow-up. Changes from predischarge to 12 month study were significant in the regional ejection fraction in the anteroseptal (33.1 +/- 14.7 vs 40.1 +/- 13.3; p < 0.001), inferoseptal (34.6 +/- 15.8 vs 42 +/- 16.9; p < 0.001), apical (46.3 +/- 19.1 vs 50.8 +/- 19.7; p < 0.01), antero-medial (50.6 +/- 22.4 vs 56.6 +/- 24.3; p < 0.01) and anteroapical (51.6 +/- 23.5 vs 58 +/- 27.5; p < 0.01) segments. In the anterobasal segment, regional ejection fraction only showed a statistical tendency to increase during follow-up and changes in inferior and lateral segments, distal to the infarcted area, were minor and without statistical significance. The most distinct infarct-related segments, antero- and inferoseptal, showed significant increases in the main group of patients, revascularized or nonrevascularized, undergoing thrombolitic or conventional therapy, with single or multivessel disease. Only patients without residual stenosis of the infarct-related artery (the left descending anterior) disclosed negligible or negative changes without statistical significance. Percutaneously dilated patients showed the highest increase of the infarct-related segments regional ejection fraction. In multivessel disease, the infarct-related segments regional ejection fraction did not increase significantly in surgically treated patients, conversely to those who underwent medical therapy. CONCLUSIONS: Global and regional ejection fraction of the infarcted area increased significantly during the first year after anterior myocardial infarction, mainly prior to six months patients with significant residual stenosis of the artery related to the infarct. Recovery is present both in patients who underwent thrombolysis or conventional treatment at admittance and revascularization or medical treatment before discharge and is inversely correlated to the predischarge global ejection fraction value. This evolution suggests that a significant amount of stunned myocardium is still present before discharge.

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