Occurrence of osteoporosis & factors determining bone mineral loss in young adults with Graves’ disease.

Background & objectives: There is a paucity of data with conflicting reports regarding the extent and pattern of bone mineral (BM) loss in Graves’ disease (GD), especially in young adults. Also, interpretation of BM data in Indians is limited by use of T-score cut-offs derived from Caucasians. This study was aimed to evaluate the occurrence of osteoporosis in active treatment naive patients with GD and determine the factors predicting BM loss, using standard T-scores from Caucasians and compare with the cut-offs proposed by the Indian Council of Medical Research (ICMR) for diagnosing osteoporosis in Indians. Methods: Patients with GD, >20 yr age without any history of use of anti-thyroid drugs, and normal controls without fracture history, drugs use or co-morbidities underwent BM density (BMD) assessment at lumbar spine, hip and forearm, thyroid function and calcium profile assessment. Women with menopause or premature ovarian insufficiency and men with androgen deficiency were excluded. Results: patients with GD (n=31) had significantly lower BMD at spine (1.01±0.10 vs. 1.13±0.16 g/cm2), hip (0.88±0.10 vs. 1.04±0.19 g/cm2) and forearm (0.46±0.04 vs. 0.59±0.09 g/cm2) compared with controls (n=30) (P<0.001). Nine (29%) and six (19.3%) patients with GD had osteoporosis as per T-score and ICMR criteria, respectively. None of GD patients had osteoporosis at hip or spine as per ICMR criteria. Serum T3 had strongest inverse correlation with BMD at spine, hip and femur. Step-wise linear regression analysis after adjusting for age, BMI and vitamin D showed T3 to be the best predictor of reduced BMD at spine, hip and forearm, followed by phosphate at forearm and 48 h I131 uptake for spine BMD in GD. Interpretation & conclusions: Osteoporosis at hip or spine is not a major problem in GD and more commonly involves forearm. Diagnostic criterion developed from Caucasians tends to overdiagnose osteoporosis in Indians. T3 elevation and phosphate are important predictors of BMD. Baseline I131 uptake may have some role in predicting BMD.

Effect of a Low Iodine Diet vs. Restricted Iodine Diet on Postsurgical Preparation for Radioiodine Ablation Therapy in Thyroid Carcinoma Patients

PURPOSE: The radioiodine ablation therapy is required for patients who underwent a total thyroidectomy. Through a comparative review of a low iodine diet (LID) and a restricted iodine diet (RID), the study aims to suggest guidelines that are suitable for the conditions of Korea. MATERIALS AND METHODS: The study was conducted with 101 patients. With 24-hour urine samples from the patients after a 2-week restricted diet and after a 4-week restricted diet, the amount of iodine in the urine was estimated. The consumed radioiodine amounts for 2 hours and 24 hours were calculated. RESULTS: This study was conducted with 47 LID patients and 54 RID patients. The amounts of iodine in urine, the 2-week case and 4-week case for each group showed no significant differences. The amounts of iodine in urine between the two groups were both included in the range of the criteria for radioiodine ablation therapy. Also, 2 hours and 24 hours radioiodine consumption measured after 4-week restrictive diet did not show statistical differences between two groups. CONCLUSION: A 2-week RID can be considered as a type of radioiodine ablation therapy after patients undergo a total thyroidectomy.

Optimization of ablative dose for thyroid cancer

Esta investigación propone un protocolo de planificación individualizada de dosis ablativas basado en el metabolismo individual del paciente y en la medida de la masa de los remanescientes tiroideanos. Utilizando SPECT, el metabolismo de I-131 fue estudiado en 9 pacientes tiroidectomizados, y la actividad optima para la terapia fue calculada y comparada con la actividad fija establecida de 3.7 GBq (100 mCi), que és en general administrada. Fue observado que 78 por ciento de las pacientes podrian tener recibido actividades reduzidas de 131I (de 0.8-3.2 GBq (20-87 mCi)). Además, 33 por ciento destes pacientes podrian recibir actividades tan bajas que no necesitarian internamiento hospitalar. Visando facilitar los calculos de la actividad terapeutica optima de 131I hacia pacientes individuales, un programa de planificación de dosis simples y rápido fue criado (PlanDose). Este protocolo de cálculo de actividades de 131I específicas para el paciente permite una mejor determinación de la dosis ablativa necesaria en caso de pacientes con carcinoma diferenciado de la tiroide, y és un ejemplo de optimización de la práctica de protección radiologica.

This investigation proposes a protocol for planning of thyroid ablation therapy for individual patients, based on individual patient metabolic data and measured thyroid remnant masses. Using SPECT, I-131 uptake and clearance was studied in 9 patients who had undergone thyroidectomies, and the optimum activity for their therapy was calculated and compared to the established fixed activity of 3.7 GBq (100 mCi), which normally would have been assigned. It was observed that 7 of the patients could have received reduced activities of 131I (from 0.8-3.2 GBq (20-87 mCi)). In addition, 3 patients could have received low enough activities to have been discharged from the hospital. To facilitate the calculations of the optimum therapeutic activity of 131I for individual patients, a computer program was created (PlanDose). This protocol of calculated optimal patient-specific 131I activities allows a better determination of the necessary ablative dose for patients with differentiated carcinoma of the thyroid, and is an important example of optimization of the practice of radiation protection.

Efficacy in the use of recombinant TSH (thyrogen©) in the ablative treatment of compressive goiters with low uptake of I-131

Este estudio trata de demostrar la utilidad del TSH Combinado en la ablación radioisotópica de los bocios inmersos con baja captación de radioiodo. Se estudiaron tres pacientes del sexo femenino con una media etárea de 70 años, portadoras de bocios inmersos. Dos de las pacientes presentaron síntomas de obstrucción de las vías aereas superiores en todas ellas, estaba contraindicado el tratamiento quirúrgico del bocio. La captación tireoidea del I-131 de 24 horas era baja en todos los casos. Fueron administradas de 2 a 3 dosis de 0,9 ms de Thyrogen© a cada una de las pacientes, tratando de estimular la captación tieroidea para potenciar o aumentar la efectividad de las dosis terapéuticas del radiiodo (calculadas en 30, 50 y 100 mCi). Las captaciones tireiodeas del I-131 iniciales de 6,13 y 21 por ciento en 24 horas alcanzarón 59, 50 y 75 por ciento respectivamente, con el uso del Thyrogen©. Después de la radioterapia, las masas médiastinales disminuyeron en promedio de 1.5 cm en el mayor diámetro transverso, en un tiempo promedio de seguimento tomografico de 6.6 meses. Las pacientes que sufrian de síntomas obstructivos de las vias aereas alcanzarón remisión con el tratamiento. La administración del Thyrogen© constituye una etapa fundamental para la terpéutica ablativa de los bocios inmersos con baja captación de radiiodo, una vez que no seria posible alcanzar niveles satisfactorios de captación radioactiva sin el estímulo exógeno

Distribución biológica de un extracto neuroactivo obtenido de la anémona Bunodosoma granulífera / Biological distribution of neuroactive extract obtained bunodosoma granulifera anemone

Se estudió la distribución biológica del extracto ácido acético-acetónico de Bunodosoma granulífera. Se analizó la afectación de la biodistribución de los polipéptidos radioiodados en función de la pureza radioquímica, la dosis y el tiempo, previa inyección i.p. en ratones. La detección de radioactividad en el cerebro, a partir de los 5 min de inyectado el animal, permite suponer la posible acción del veneno en el sistema nervioso central.

Removal and release of recirculating atrial natriuretic peptide (ANP) by rabbit lungs perfused in situ

The finding that radioiodinated, synthetic ANP (125I-ANP), analogous to the ANP secreted by the right atrium, binds to spepcific sites odf endothelial cells, smooth muscle, adrenals and lungs (1-3) raised the importance of anlyzing lung-ANP interactions. Rabbit lungs were accordingly loaded with 125I-ANP, 2000 Ci/mM (2.5 pM) in Krebs-albumin recirculating perfusion medium at a rate of 20 ml/min, over 27 min. 125 I-ANP binding was estimated by taking samples at 2-min intervals from the perfusate. Fourteen min after recirculation, uptake was maximal (66.4 ñ 5.2%, N = 8) (X ñ SEM) and not different from that observed after a single passage through the lungs and was dose-dependent, antagonized by unlabelled ANP. The system was then changed to single-pass washout and efflux curves were obtained, collecting the entire efflux every 6 s per sample, over 15 min. Efflux curves after 125I-ANP loading fitted a bi-exponential decay model (Y(to) = Y(t)e -b1t+ Y(t)e -b2t). Lung ANP uptake/ release may be involved in regulatinh systemic concentrations and hence renal and other actions of ANP

Circulating immune complexes in breast cancer patients

El objetivo de este trabajo fue evaluar la presencia de complejos inmunes circulantes (CIC) en el suero de pacientes con cáncer de mama, Los CIC de 146 pacientes con cáncer de mama se detectaron por el método de combinación a I-Clq. Se consideraron como valores elevados aquellos que excedieron la media aritmética (x+2DS) de los valores obtenidos en el grupo control (11%). Los valores elevados de combinación a Clq radioactivo fueron detectados antes del tratamiento en los 3 grupos estudiados con la siguiente incidencia: N0: 42%; N1: 67%; N2: 86%. En los primeros 12 meses post-tratamiento los niveles de CIC descendieron en los 3 grupos: N0: 18%; N1: 9%; N2: 23%. Sin embargo, a partir de los 12 meses post-tratamiento la incidencia fue en N0: 14%; N1: 62%; N2: 78%. Estos resultados fueron comparados con los valores obtenidos en el suero de 45 pacientes con displasia de mama

Caracterizaçäo da ligaçäo do 125 ITSH ao seu receptor em hiperplasias tiroidianas hipocaptantes / Caracterization of the binding of 125 ITSH to its receptor in hypocaptant thyroid hyperplasias

Acredita-se que o desarranjo metabólico celular existente no bócio simples possa ser conseqüência de um desequilíbrio das açöes do TSH sobre a glândula tiróide. Já que a ligaçäo do TSH ao seu receptor é a primeira etapa na gênese de seus efeitos biológicos a nível da célula alvo, objetivou-se na presente investigaçäo caracterizar a ligagçäo de 125 ITSH ao seu receptor em fragmentos de tiróides humanas de pacientes portadores de nódulo "frio" e anatomopatológico de hiperplasia folicular benigna. Os tecidos foram obtidos no ato cirúrgico e imediatamente armazenados em nitrogênio líquido. Após determinaçäo das condiçöes ótimas de incubaçäo (duraçäo, pH do meio e concentraçäo protéica) e empregando-se a análise de Scatchard, verificou-se näo haver diferenças significativas quanto à capacidade de ligaçäo dos receptores de TSH, quando comparada à do tecido normal paranodular. Por outro lado, observou-se nítida diminuiçäo da constante de dissociaçäo desses receptores, indicando maior afinidade pelo TSH. Sabe-se que o iodo intracelular pode interferir nas açöes do TSH sobre a célula folicular tiroidiana. Supöe-se que isto seja decorrente de um efeito de ligaçäo do TSH ao seu receptor. Devido à sua incapacidade de organificaçäo do iodo, os módulos "frios" apresentam diminuiçäo do conteúdo de iodo intracelular. Assim, acredita-se que as alteraçöes encontradas no presente estudo sejam conseqüência do baixo conteúdo de iodo da célula folicular hiperplásica

Problems Associated with I-125 Oxytocin Binding to Membrane Receptors

Radioiodinated oxytocin prepared by the lactoperoxidase method exhibited a substantial biologic activity in uterotonic assay of the rat uterus. 125I-oxytocin was bound to the uterine membrane particulate fraction, but the unlabelled oxytocin did not inhibit the binding of 125I oxytocin to the membrane fraction of rat uterus. Cold iodinated oxytocin, however, inhibited the 125I-oxytocin binding to the membrane fraction of rat uterus in proportion to its concentration. These results suggest that 125I-oxytocin is not a suitable radioligand for oxytocin receptor binding study.