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Biomedical subjects

M Estorch

Publications and source records attributed to M Estorch.

71 records · Page 4Linked to original sources
PubMed1987

Lithium as an adjuvant of iodine-131 uptake when treating patients with well-differentiated thyroid carcinoma.

Differences in the I-131 uptake by 14 metastatic lesions from well-differentiated thyroid carcinoma and 12 local remnants of normal thyroid tissue before and after an adjuvant therapy with lithium carbonate, were observed. After the adjuvant treatment and administration of an I-131 tracer dose, a considerable increase of radioiodine uptake in all metastatic lesions was found (P less than 0.001), but only a slight increase was found in 50% of the normal tissue. The response to lithium carbonate by neoplastic tissue seems to be different than that of the normal thyroid tissue, and produces a lengthening of the average I-131 biologic life that could be helpful when treating well-differentiated thyroid carcinoma.

Adenocarcinoma↗
PubMed1986

Cold sternal image as a sign of metastatic involvement.

Two cases are reported in which bone imaging with Tc-99m MDP showed sternal areas without tracer uptake corresponding to bone metastases compromising blood supply to the sternum itself. Radiographs were normal in both cases.

Adult↗
PubMed1984

Gastric emptying of solid and liquid meals in healthy young subjects.

Gastric emptying was measured in 50 young healthy subjects by means of sequential scintigraphy with two radioactive markers. Gastric emptying of the solid component of the meal was slower than that of the liquid component, corresponding to a linear model (T 1/2, 112 min). Gastric emptying of the liquid component was different, following an exponential model, although only after 45 min (100% of the liquid marker retained in the stomach after 15 min, 56.7% after 45 min, 43.3% after 75 min, and 35.5% after 105 min). Significant differences were found in gastric emptying of both solids and liquids among sexes; women emptied the stomach more slowly than men regardless of age, weight, height, or body surface. A relationship was found between gastric emptying and the phase of the menstrual cycle. Furthermore, a quicker emptying of the liquid component was observed in smokers. These factors should be considered in the evaluation of gastric emptying studies.

Adult↗
PubMedDate not supplied

Myocardial iodine-labeled metaiodobenzylguanidine 123 uptake relates to age.

BACKGROUND: 123I-labeled metaiodobenzylguanidine (123I-MIBG) is used increasingly to assess cardiac adrenergic neuron function. Few studies have reported data on myocardial MIBG uptake in relation to age, with contradictory results. This study reports the results of myocardial MIBG studies in untreated patients with cancer to assess the influence of age on myocardial MIBG uptake. METHODS AND RESULTS: Thirty-nine patients with cancer enrolled in a study to assess the effect of doxorubicin administration on adrenergic neuron function underwent baseline studies with 123I-MIBG before chemotherapy. None of the patients had a history of neuropathy, previous cardiac disease, or previous chemotherapy or mediastinal radiotherapy. Myocardial MIBG uptake was quantified by a heart/mediastinal ratio (HMR) 4 hours after intravenous administration of 5 mCi 123I-MIBG. The mean age of patients was 38 years, ranging from 16 to 75 years. Ten patients were below 20 years, 13 patients were between 20 and 40 years, six patients were between 40 and 60 years, and 10 patients were greater than 60 years of age. Myocardial 123I-MIBG uptake was observed in all patients, with a mean HMR of 1.85 +/- 0.29 (range 1.31 to 2.62). HMR correlated with age (r = -0.6264; p < 0.001). A decrease in 123I-MIBG uptake with aging was observed. The mean HMR of patients of less than 20 years was 2.07, of patients between 20 and 40 years 1.89, of patients between 40 and 60 years 1.83, and of patients greater than 60 years 1.56. The best separation was observed comparing patients who were greater than 60 years (mean HMR 1.56 +/- 0.16; range 1.31 to 1.78) with patients who were less than 60 years of age (mean HMR 1.95 +/- 0.24; range 1.56 to 2.62; p = 0.003). CONCLUSIONS: Myocardial 123I-MIBG uptake relates to age. A decrease in myocardial MIBG uptake is observed with aging, especially in those patients over 60 years of age. The influence of age on myocardial MIBG uptake has to be taken into account when studies are designed to assess cardiac adrenergic neuron function with 123I-MIBG.

3-Iodobenzylguanidine↗
PubMedDate not supplied

Influence of prolonged exercise on myocardial distribution of 123I-MIBG in long-distance runners.

BACKGROUND: A study was conducted to determine if prolonged exercise could provoke sympathetic neuronal alteration in an athlete's heart through assessment of myocardial distribution of 123I-metaiodobenzylguanidine (MIBG) in nine ultramarathon runners at baseline and after a 4-hour race. METHODS AND RESULTS: After injection of 370 MBq of 123I-MIBG, the athletes ran for 4 hours, covering 45 +/- 8 km. Planar and single-photon emission computed tomography (SPECT) images of the thorax were acquired at the end of the race. Two weeks later, studies at baseline were performed. A heart:mediastinum ratio (HMR) was calculated to quantify MIBG uptake. Basal MIBG studies showed normal myocardial tracer uptake, on both planar and SPECT images, and the HMR was 1.84 +/- 0.16. After the 4-hour race, MIBG studies showed decreased myocardial uptake in all athletes, and the HMR was 1.70 +/- 0.18 (p < 0.005). A positive correlation between the percentage of decrease of HMR after the race and the distance covered was observed (r = .910, p < 0.001). CONCLUSIONS: Myocardial MIBG activity is decreased by prolonged exercise in long-distance runners. The degree of reduction of myocardial MIBG activity is related to the distance covered. Prolonged exercise, as sustained sympathetic stimulus, may alter myocardial distribution of MIBG.

3-Iodobenzylguanidine↗
PubMedDate not supplied

Noninvasive localization of human atherosclerotic lesions with indium 111-labeled monoclonal Z2D3 antibody specific for proliferating smooth muscle cells.

BACKGROUND: Targeting exclusive antigens in atherosclerotic plaques with antibodies may provide a noninvasive means to detect rapidly proliferative atherosclerotic lesions. 111In-labeled negative charge-modified Z2D3 F(ab')2 (Z2D3) specific for an antigen expressed exclusively by proliferating smooth muscle cells has been shown to accumulate in rabbit atherosclerotic plaques. METHODS: The safety, biodistribution, accumulation, and elimination of Z2D3 were assessed in 11 patients who were candidates for carotid endarterectomy. The presence of atheromas in these patients was confirmed by angiography and Doppler ultrasound. Z2D3 (250 microg) labeled with 5 mCi of 111In was administered by slow intravenous injection. Planar and single photon emission computed tomography (SPECT) images were obtained 4, 24, 48, and 72 hours later. Carotid endarterectomy was performed and the surgical specimens were imaged, weighed, gamma-counted, and analyzed by immunostaining. RESULTS: Uptake of Z2D3 at the site of the carotid plaques was observed in the planar and SPECT views at 4 hours in all subjects. In addition, antibody uptake was noted in the contralateral vessel in 5 subjects. SPECT images identified the atherosclerotic plaques with focal uptake. The antibody uptake corresponded with the angiographic location of the disease. Immunohistochemical studies of the endarterectomy specimens confirmed the localization of Z2D3 into the plaque areas containing smooth muscle cells. Adverse drug reactions were not observed. CONCLUSION: This study demonstrates the feasibility of targeting atherosclerotic lesions with negative charge-modified antibody. It also proposes the possibility of selective identification of various components of atherosclerotic plaque, which may contribute to determining strategies of intervention in future.

Aged↗
PubMedDate not supplied

Myocardial sympathetic innervation in the athlete's sinus bradycardia: is there selective inferior myocardial wall denervation?

BACKGROUND: Sinus bradycardia in trained athletes is predominantly a manifestation of increased vagal tone, but it is not known whether an alteration in the cardiac sympathetic system can contribute to blunted chronotropic response. This study assessed the integrity of the sympathetic system in trained athletes with sinus bradycardia by means of the iodine-123-metaiodobenzylguanidine (123I-MIBG) procedure. METHODS AND RESULTS: Fourteen athletes with sinus bradycardia and 8 athletes with a normal heart rate were explored by means of planar and single photon emission computed tomography MIBG studies. The heart/mediastinum ratio, regional myocardial distribution, and percent of regional myocardial MIBG uptake were evaluated. The heart/mediastinum ratio in athletes with sinus bradycardia was 1.87+/-0.10, and in athletes with a normal heart rate, the heart/mediastinum ratio was 1.86+/-0.16 (P = not significant). In athletes with sinus bradycardia, the regional distribution of MIBG showed an inferior and apical uptake defect in 8 athletes, an inferior, apical, and septal defect in 3 athletes, an inferior defect in 1 athlete, and normal distribution in 2 athletes (14%). In athletes with a normal heart rate, the regional distribution of MIBG showed an apical uptake defect in 3 athletes and normal distribution in 5 athletes (63%). The percent of regional MIBG uptake in the inferior region was significantly reduced in athletes with sinus bradycardia (44%+/-13% vs. 72%+/-11%, P<.01). CONCLUSION: These results show severely reduced myocardial MIBG distribution in the inferior region in athletes with sinus bradycardia, suggesting selective inferior myocardial wall sympathetic denervation, which may be related to increased vagal tone.

3-Iodobenzylguanidine↗
PubMedDate not supplied

[Dementia with Lewy bodies and Alzheimer's disease: differential diagnosis by cardiac sympathetic innervation MIBG imaging].

UNLABELLED: Dementia with Lewy bodies (DLB) is the second most common cause of degenerative dementia after Alzheimer's disease (AD). At present, pre-mortem diagnosis of DLB can only be made clinically using the International Consensus Criteria. However, an accurate differential diagnosis between these diseases could improve the therapeutic handling of patients with DLB, due to their supersensitivity to neuroleptic treatment and the difficult treatment of their psychotic symptoms. OBJECTIVE: To assess the utility of cardiac MIBG imaging as diagnostic study for DLB, to help in the differential diagnosis with AD. MATERIAL AND METHODS: Cardiac MIBG imaging was performed in 11 patients with clinical criteria of probable DLB (7 males, mean age 77 years [range 62-89 years], mean MMSE 17 [range 11-28], and in 9 patients with clinical criteria of probable AD (3 males, mean age 79 years [range 61-87 years], mean MMSE 17 [range 4-25]). Planar anterior images of the thorax were acquired at 15 minutes. (early study) and 4 hours (late study) after tracer injection. Myocardial MIBG activity was quantified by means of a heart-to-mediastinum ratio (HMR). A HMR > 1.8 was considered normal. RESULTS: Respect AD patients, patients with DLB showed decreased HMR in the early study (1.34 +/- 0.27 [range 1.03-1.98] vs. 1.84 +/- 0.22 [range 1.53-2.15], p<0.001) and in the late study (1.22 +/- 0.23 [range 0.95-1.75] vs. 1.73 +/- 0.08 [range 1.59-1.89], p<0.0001). CONCLUSIONS: Cardiac MIBG imaging could be a useful tool for differential diagnosis between DLB and AD.

3-Iodobenzylguanidine↗
PubMedDate not supplied

[Biventricular functional adaptation during a prolonged race. An analysis of global and regional ventricular function].

To determine the effects of a six-hour competitive race on left and right ventricular performance, 99mTc gated blood pool scans were performed to 6 long distance runners before the race (rest), each hour during the race and one hour after concluding the exercise (recovery). Heart rate increased during the race, peaking at 4th hour of competition (55 +/- 3 to 110 +/- 9 lpm; p = 0.001). Evolution of right ventricular ejection fraction showed a similar behavior with the evolution of left ventricular ejection fraction during the competition (r = 0.39; p = 0.006). Blood volume in the lungs increased at the end of the race (index 1.13 +/- 0.14) normalizing at recovery (index 1.03 +/- 0.03). Left and right ventricular peak filling rate had an inverse correlation with pulmonary blood volume (r = -0.31; p = 0.041 and r = -0.47; p = 0.001 respectively). Both left and right ventricular ejection fraction had an inverse correlation with pulmonary blood volume (r = -0.38; p = 0.006 and r = -0.34; p = 0.01 respectively). The anteroseptal regional ejection fraction showed an inverse correlation with end-systolic and end-diastolic volume (r = -0.32; p = 0.03 and r = -0.4; p less than 0.01 respectively). The posterolateral region showed a parallel evolution with the global ejection fraction for both left and right ventricles (r = 0.57; p less than 0.0001 and r = 0.38; p = 0.009 respectively). In conclusion, a transient biventricular functional adaptation during a prolonged race is related to pulmonary blood volume redistribution and to a higher preload for both ventricles and a greater afterload for the right ventricle. The posterolateral and inferoapical regions show a similar behavior as both left and right ventricular ejection fraction, response that does not occur with the anteroseptal regional ejection fraction.

Adaptation, Physiological↗