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Biomedical subjects

A Rivas Sánchez

Publications and source records attributed to A Rivas Sánchez.

11 recordsLinked to original sources

[Triiodothyronine intoxication. A clinical and phamacokinetic study].

A woman, thyroidectomised because of a thyroid papillary carcinoma, interrupted temporarily her levothyroxine intake in order to be subjected to an extension study five weeks later. To minimise her symptoms for the first three weeks, a treatment was prescribed consisting of one 25 micro g-capsule of triiodothyronine every 8 hours. Nine days later she complained of abdominal pain, nausea, vomiting, fever of 40 degrees C and chest discomfort. A serum total triiodothyronine of 575.2 nmol/l was measured by chemoluminiscent immunoassay eleven hours after the intake of the latest capsule (normal level: 1.1-2.9 nmol/l). Along the following ten days the patient suffered from delirium, agitation, tachycardia, hypertension, constipation and later diarrhoea, but neither arrythmias nor axillary temperature over 38 degrees C. Fifty-nine measurements of the serum total triiodothyronine were performed in order to determine the kinetics of elimination of this drug. We estimate that the maximal serum concentration after the intake of the latest capsule could be 794.3 nmol/l, i.e. 397 times higher than the mean normal value. The elimination half-life was 24 hours 40 minutes. The charcoal haemoperfusion had no impact on the velocity of elimination. The concentration of triiodothyronine became normal 200 hours after the intake of the latest capsule, but the clinical manifestations still lasted three days more. The pharmacokinetic data suggest that this intoxication could be due to the intake of capsules containing 5 mg of triiodothyronine, i.e. a dose 200 times higher than that prescribed by her physician.

Absorption↗

[Association of thyroid hemiagenesis and Graves disease].

Thyroid hemiagenesis is a very infrequent abnormality. We present a case of Graves disease associated to a congenital hemiagenesis of the thyroid gland. The thyroid scintigraphy, ultrasonography and laboratory analysis (that showed the existence of thyroid hyperfunction and the present of thyroid stimulating antibodies) were decisive in the diagnosis.

Atrophy↗

[Value of 123I-MIBG scanning, neuron-specific enolase and serum ferritin in the diagnosis and follow-up of patients with neuroblastoma].

INTRODUCTION: The neuroblastoma (NB) is one of the most common pediatric malignant neoplasms. The most commonly used tumor markers in the diagnosis and follow-up of this tumor are the serum neuron-specific enolase (NSE), ferritin and lactic dehydrogenase and urinary vanillymandelic and homovanillic acid. The common imaging modalities are CT, MRI and 123I or 131I-meta-iodobenzylguanidine scintigraphy. AIM: The aim of this study is to assess the value of 123I-meta-iodobenzylguanidine (MIBG) scintigraphy and serum determinations of NSE and ferritin in the diagnosis and evolution of NB patients. MATERIAL AND METHODS: 20 patients (8 female, 12 male) whose ages ranged from 2 months to 9 years with a mean age of 2.64 years diagnosed of NB. 47 123I-MIBG scans, 47 NSE determinations and 47 ferritin ones were selected. RESULTS: At the time of diagnosis, 100% of the 123I-MIBG scans were positive. 65% of NSE determinations presented clearly pathological levels and 15% were very near to the cut-off point. Only 45% of the ferritin levels were increased. The differences between the lesions visible by 123I-MIBG scanning before and 3 months after treatment as well as NSE and ferritin levels were studied. When the Student's T test was applied, we found statistically significant pre and post-treatment differences in 123I-MIBG scanning and NSE. In the case of ferritin, there was no statistical significance in spite of the decrease in the values. The direct correlation and Spearman correlation between laboratory data and 123I-MIBG scanning as well as correlation between NSE and ferritin were also studied. There was a good correlation between 123I-MIBG and NSE and between NSE and ferritin. We have also studied the data in 7 relapses. CONCLUSIONS: 123I-MIBG scintigraphy and serum determination of NSE are two successful diagnostic tools for the diagnosis and evolution of NB patients.

3-Iodobenzylguanidine↗

[Thyroid scintigraphy and body scanning with 67 Ga in a case of primary thyroid lymphoma].

The case of a 60-year old woman first presented a rapidly growing left cervical mass is presented. The fine needle aspiration-puncture (FNAP) lead to a diagnosis of thyroiditis. Due to the persistence of the symptoms, the FNAP was repeated again but was not conclusive, so that a surgical biopsy was performed. The pathological diagnosis was diffuse large cell primary thyroid lymphoma (PTL). The PTL is a rare entity that accounts for less than 1% of all the Non-Hodgkin's lymphomas. The thyroid scintigraphy showed the existence of a cold nodule in the left thyroid lobule and the 67Ga scan revealed a large abnormal lesion in the mediastinum that extended to the right latero-cervical region. After two chemotherapy courses, the 67Ga scan was normal.

Antineoplastic Combined Chemotherapy Protocols↗

[Simple thyroid cyst].

Simple or true thyroid cysts are very rare. We only have found one case in which colorless and acellular transparent fluid has been found by means of the fine needle aspiration puncture (FNAP). We report the case of a 33 year old female who first presented with a rapidly growing thyroid nodule. The thyroid scintigraphy revealed the existence of a cold nodule and the ultrasonography showed a lesion having a cystic appearance. The FNAP was performed and was both diagnostic and therapeutic in this case.

Adult↗

[Hepatobiliary scintigraphy in a case of acute cholecystitis in childhood].

Acute cholecystitis is an uncommon disease in childhood. Few cases in patients under 10 years of age have been found in literature. An eight-year old male patient with no history of interest who had acute acalculous cholecystitis was reported. Ultrasonographic and isotopic studies led to the diagnosis and control of the patient's evolution.

Acute Disease↗

[Uptake of 99mTc-diphosphonates due to brain infarction].

The case of a patient who came to the Nuclear Medicine Department for a bone scintigraphy to rule out bone metastasis because of a lung neoplasm is presented. Some days before, the patient had suffered a right brain infarction. 99mTc-MDP uptake could be seen in the infarction area. Different mechanisms of 99mTc phosphates deposition in tissues other than bones are reviewed in this article.

Aged↗

[Normally functioning ectopic thyroid in adults. Apropos of 4 cases].

Four cases are presented of ectopic thyroid tissue in adult women who underwent for thyroid study for different motives. Radioisotopic uptake was absent in the usual thyroid location. Thyroid function was normal in every case and no psychomotor abnormalities were present. In one case, echography revealed an atrophic thyroid in the usual location in association with thyroid ectopy. The literature of thyroid ectopy was reviewed and the preponderant role of radioisotopic scan is underlined, together with thyroid echography in the imaging diagnosis of neck masses.

Adult↗

[Pericardial effusion as a possible cause of false positives in I-131 radionuclide scans].

The case of a patient who had undergone surgery for papillary carcinoma of the thyroid is reported. After administering a therapeutic 131I capsule, the radionuclide scan showed a diffuse, "halo-like" thoracic uptake in the precordial region. The patient's normal thyroglobulin levels and the characteristics of radionuclide uptake did not suggest metastasis. Chest radiography and ultrasonography identified pericardial effusion, which was attributed to hypothyroidism.

Adult↗