[Tomographic studies of myocardial perfusion normality with 99m Tc-Tetrofosmin. Spanish multicenter study]. / Estudios tomográficos de normalidad de perfusión miocárdica con 99mTc-Tetrofosmina. Estudio multicéntrico español (I). Aspectos técnicos: diseño del estudio y control de calidad.

As a first phase in a nationwide multicenter study to obtain myocardial perfusion normality patterns, this work presents the study design and quality control methodology used to guarantee that the gammacameras fulfilled some minimum quality requirements. The following aspects were considered in the study design in order to guarantee the homogeneity and interchangeability of the results: creation and structure of the work group, data interchange system, data selection and acquisition, centralized archiving and processing, assessment system, study acceptance criteria and distribution of the results. To carry out the instrumental quality control, three phantom studies were established, one to control the rotation center, another to verify tomographic uniformity and a third to simulate the shape and orientation of the left ventricle. The three phantoms circulated through all of the 18 participating centers in this project, which corresponded to 19 gammacameras. Very strict guidelines had to be followed in the acquisition and processing of these phantom studies. If any camera and/or center did not fulfill the criteria established, it was advised of the problem detected in order to correct it. Once the defect was repaired, all the phantoms were sent again for verification. Uniformity of the rotation center was quantified by means of the eccentricity of a 360 degrees orbit, admitting up to a maximum of 10%. Tomographic uniformity was visually assessed, taking in account the number of slices with rings and their contrast and finally no artifacts could be present in the reconstructed study of the ventricle. The center of rotation was within limits in all the cameras except one case while the tomographic uniformity was incorrect in 6 cases. All the departments, except one, corrected the defects detected, and passed the acceptance test. The results made it possible to guarantee adequate homogeneity and instrumental quality in this multicenter study.

[Tomographic studies of myocardial perfusion normality with 99m Tc-Tetrofosmin. Spanish multicenter study]. / Estudios tomográficos de normalidad de perfusión miocárdica con 99mTc-Tetrofosmina. Estudio multicéntrico español (II). Aspectos clínicos.

This objective of this study was to obtain a pool of Myocardial Perfusion SPECTs with a 99mTetrofosmin stress/rest one day protocol in normal volunteers having a less than or equal to 5% likelihood of coronary artery disease that represents normalcy in the Spanish population. A total of 169 volunteers from 15 hospitals were studied. The volunteers were divided into 5 groups: Groups 1, 2 or 3 corresponding to men < 30 years (n = 33), men between 30 and 50 years (n = 32), or men > 50 years (n = 31); Groups 4 or 5: premenopausal (n = 38) or postmenopausal women (n = 35). A clinical history, physical examination, clinical laboratory parameters, echocardiography and a symptom limited exercise stress test were performed in all of them and had to be normal. The mean likelihood of coronary artery disease was 1.15 +/- 1.07%.Twenty-four segments were analyzed in each study and were classified into 5 grades of uptake (1 = normal, 2, 3, 4 = mild, moderate or severe defect and 5 = no uptake). Defects were then analyzed according to sex and location. Considering the stress and rest studies separately (8,112 segments), only 19 moderate and 75 mild defects were found, these corresponding to 16 volunteers, with more inferior defects in men and anterior defects in women. These data validate the normalcy of our population. A pool of Myocardial Perfusion SPECTs with a 99mTetrofosmin stress/rest one day protocol in normal volunteers that represents Spanish normal values was obtained.

[Contribution of radioguided detection and selective biopsy of the sentinel lymph node to staging in 100 patients with cutaneous melanoma]. / Contribución de la detección radioguiada y biopsia selectiva del Ganglio centinela al estadiaje de 100 pacientes con melanoma cutáneo.

OBJECTIVE: A selective sentinel node (SN) biopsy appears to be an alternative to conventional lymph node dissection for staging patients with cutaneous melanoma. This study has aimed to analyze our experience in the localization of the sentinel node with a probe detector and lymphoscintigraphy and its utility in the staging of this disease. MATERIAL AND METHODS: 100 patients, 56 female and 44 male, 51.5 31.5 mean age, diagnosed of cutaneous melanoma were studied. The lymphoscintigraphy was performed in all cases to detect the area of lymphatic drainage after peritumoral intradermal administration of 600 uCi of 99mTc-colloidal sulfur, and planar images were acquired every 10 minutes until activity was detected in these areas. Afterwards, the intraoperative localization of the sentinel node with a probe detector was performed and the selective biopsy of the node was sent to the Pathology Department for its histologic study. RESULTS: The lymphoscintigraphy study was positive in 99 of the 100 cases and it was identified intraoperatively in 98 cases. The histologic analysis was negative in 78.9% and positive in 21.1% of the nodes. CONCLUSIONS: Radioisotopic lymphography and intraoperative probe detection are two very useful techniques for locating the sentinel node and staging patients with cutaneous melanoma. Many patients are benefiting from the selective biopsy of the sentinel node because of the decreased post-surgical morbidity and better staging of the cutaneous melanoma.

[Evaluation of cardiac sympathetic innervation with 123I-metaiodobenzylguanidine in patients with diabetes mellitus]. / Valoración de la inervación simpática cardíaca con 123I-metayodobencilguanidina en pacientes con diabetes mellitus.

OBJECTIVES: To evaluate the usefulness of iodine-123 metaiodobencylguanidine (123I-MIBG) in the study of the cardiac autonomic neuropathy in insulin-dependent diabetic patients, by means of: a) analysis of heart to mediastinic ratio and tomographic images with 123I-MIBG; b) comparison with conventional non-invasive cardiac reflex test, and c) analysis of left ventricle ejection fraction. POPULATION AND METHODS: Ten patients submitted for cardiac evaluation with 123I-MIBG were compared with a control group of 11 patients. In both groups we excluded the presence of coronary pathology by means of an exercise test. We carried out planar and SPECT studies, using 123I-MIBG, and the calculation of the ejection fraction by equilibrium ventriculography. RESULTS: The uptake of 123I-MIBG in diabetic patients was significantly smaller than the control group in the calculated index (heart to mediastinic ratio: 1.64 +/- 0.20 vs 2.00 +/- 0.26; p < 0.001; SPECT index: 44.87 +/- 8.37 vs 55.54 +/- 3.96; p < 0.001). In polar images we noted a more reduced uptake in the diabetic group in the inferior wall (p = 0.020). Patients with cardiac sympa-thetic dysinnervation demonstrated less uptake in both indexes (p < 0.05 and 0.005, respectively), essentially in the inferior wall and in basal and medium territories (p < 0.05). No differences in respect to the ejection fraction parameter were found. CONCLUSIONS: Despite the small sample population, insuli-dependent diabetic patients in show a significant reduction of the uptake of 23I-MIBG, more accentuated in the base. Scintigraphy using 123I-MIBG can be an approach to investigate the pattern and the natural history of the sympathetic innervation in these patients.

[PGE and PGF2-alpha levels in the umbilical cord vessels. Relationship to acid-base equilibrium in the umbilical artery]. / Niveles de PGE y PGF2-alfa en los vasos del cordón umbilical. Su relación con el equilibrio ácido-base de la arteria umbilical.

To asses the possible role of prostaglandins in the fetoplacental circulation during delivery PGE and PGF2-alfa plasma levels were measured in the umbilical vessels of term newborns. The levels of PGF2-alfa in blood from the umbilical vein are significantly higher and more variable than in the umbilical artery; 83.38 +/- 78.05 pg/ml versus 43.28 +/- 5.32 pg/ml. PGE levels are also higher in the vein 114.73 +/- 25.16 pg/ml than in the artery 83.63 +/- 9.22 pg/ml. There was a statistically significant negative correlation between the arterial pH and PGE in the umbilical vein these results support the idea that the plasmatic umbilical prostaglandins are synthetized by the placenta the variability in the values obtained in venous umbilical blood may reflect the different times of ligation of the umbilical cord. A decrease in fetal pH may be the stimulus for the prostaglandin synthesis by the placenta.

[Osmolarity and arginine-vasopressin in children born after acute fetal-neonatal distress]. / Control osmolar y arginina vasopresina en niños nacidos después de un sufrimiento fetoneonatal agudo.

A study of urinary osmolarities and plasmatic level of arginine-vasopressin (AVP) 48 hours after birth in a group of 70 newborns (30 of which are normal and 40 of which have acute perinatal hypoxia), selected according to previously established criteria is carried out. An evolutionary study of urinary osmolarities of newborns with acute perinatal hypoxia, osmolar index and its relation to plasmatic levels of AVP during the first week of life is also considered. AVP 48 hours after birth was blatantly more elevated among those newborns who had shown acidosis at birth (p less than 0.001) which correlated significantly with urinary osmolarity, although it showed low figures (p less than 0.05). This same correlation (p less than 0.001 and p less than 0.05) appears with osmolar index and urinary osmolarity on successive days, but it is important to point out that vasopressin decreased to base values at the end of the first week of life while osmolarities in urine increased. Conclusions are: 1) AVP is higher after 48 hours of life among those newborns with acute perinatal hypoxia and decreases progressively during the first week of life, being comparable to values obtained from normally born children 48 hours after birth at the eight day of life. 2) Renal response to this hormone is slight during the first days of life.

[Diuretic isotopic urography. A method for its diagnostic use in nephro-urologic pathology in children]. / Urografía isotópico diurética (UID). Un método de aplicación diagnóstica en patología nefrourológica infantil.

In clinical pediatric urology distinction between obstructive and non obstructive dilatation of the upper urinary tract represents a difficult task for which usual procedures, both radioisotopes and conventional radiologic methods, have not discriminatory value. The aim of this investigation in to suggest a method of study that contributes to establish, in children, true diagnosis in clinical situations of hydronephrosis and to study evolution of renal function in surgical patients. Suggested technique, known an isotopic diuretic urography (UID), consists in intravenous administration of a diuretic (Furosemide, 0.4 mg/kg body weight) thirty minutes after injection of a radiotracer (I-123 Hippuran and or Tc-99-DTPA) into the vascular space and recording and analysis of variations of activity in parenchyma and renal pelvis during, at least, the following 60 m. Method described has been used in a series of 24 patients suffering from uni or bilateral hydronephrosis, with ages ranging from 2 months to 12 years. Results obtained, have shown that UID is notably superior to actually existing non-invasive methods of study of obstructive uropathy.

[Pharmacokinetics of theophylline in infantile bronchial asthma. Clinical findings]. / Farmacocinética de la teofilina en el asma bronquial infantil. Derivaciones clínicas.

Authors have studied pharmacokinetic parameters of theophylline in a sample of 21 children with bronchial asthma, through evolution of plasmatic concentrations, evaluated by RIA, in order to appreciate therapeutic response to it depending on the time-variation of such concentrations. They have determined that theophylline's kinetic obeys to a "depending dose" reaction represented by Michaelis-Menten equation. This induce them to refuse those therapeutic methods based on the establishment of maintaining doses depending on drug clearance, as minimal increases in posology can give spectacular decreases of drug clearance. They have also seen that great amplitude of individual variation for pharmacokinetics parameters of theophylline, in intra-patient studies is very short.