Antonio Bottoni

Detection of melanoma cells in peripheral blood and sentinel lymph nodes by RT-PCR analysis: A comparative study with immunohistochemistry

The presence of lymph node metastases is the best prognostic factor for predicting relapse or survival in melanoma patients. It has been demonstrated that melanoma metastases spread through the first lymph node(s) draining the tumor (sentinel lymph node, SN) to the lymphatic system and that detection of melanoma cells in peripheral blood directly correlates with prognosis in melanoma. To identify lymph node metastases and circulating melanocytes, we developed a single-step reverse transcriptase-polymerase chain reaction assay (RT-PCR) for detection of two melanoma-specific markers: the tyrosinase gene, which encodes an enzyme associated with melanin synthesis, and melanoma antigen-related T-cells, which are present in tumor infiltrating T-lymphocytes. This method detects two tumor cells in a background of 107 lymphocytes. Thirty patients with stage I–IV cutaneous melanoma entered the study. Blood samples were taken preoperatively, one month after excision of the primary melanoma lesion and the SN or total lymphadenectomy, and before the start of chemotherapy and every three months thereafter in metastatic patients. SNs were collected from 22 patients, bisected and analyzed by RT-PCR and routine pathological and immunohistochemical tests. The preliminary results indicate that RT-PCR for melanoma markers is a sensitive and valuable method for the detection of micrometastases and for early diagnosis and staging of melanoma.

Prevalence of thyroid dysfunction and effect of contrast medium on thyroid metabolism in cardiac patients undergoing coronary angiography

Background Iodinated contrast media (CM) may influence thyroid function. Precautions are generally taken in patients with hyperthyroidism, even if subclinical, whereas the risks in patients with hypothyroidism or low triiodothyronine (T3) syndrome are not considered as appreciable. Purpose To assess the presence and type of thyroid dysfunction in patients admitted for coronary angiography (CA), to assess the concentration of free-iodide in five non-ionic CM, and to evaluate changes in thyroid function after CA in patients with low T3 syndrome. Material and Methods We measured free T3, free thyroxine (T4), and thyroid-stimulating hormone (TSH) in 1752 consecutive patients prior to CA and free-iodide in five non-ionic CM. Urinary free-iodide before and 24 h after CA, and thyroid hormone profile 48 h after CA were also made in 17 patients with low T3 syndrome. Patients were followed up for an average duration of 63.5 months. Results The patients were divided into four groups: euthyroidism (60%), low T3 syndrome (28%), hypothyroidism (10%), and hyperthyroidism (2%). The free-iodide resulted far below the recommended limit of 50 μg/mL in all tested CM. In low T3 syndrome, 24-h free-iodide increased after CA from 99.9± 63 ug to 12276±9285 ug (P< 0.0001). A reduction in TSH (4.97±1.1 vs. 4.17±1.1 mUI/mL, P < 0.01) and free T3 (1.44±0.2 vs. 1.25±0.3 pg/mL, P < 0.01), with an increase in free T4 (11.3±2.9 vs. 12.5±3.4 pg/dL, P < 0.001), was found. Patients with functional thyroid disease in the follow-up had a significant lower rate survival compared to euthyroid patients (90.7 vs. 82.2%, P < 0.00001). Conclusion Thyroid dysfunction is frequent in patients who perform a CA, and low T3 syndrome is the predominant feature. The administration of contrast medium may further compromise the thyroid function.

Dabigatran malabsorption in amiodarone-induced thyrotoxicosis: a clinical report

Since 2011, several novel oral anticoagulants (NOACs) with direct mechanisms of action on thrombin and factor Xa inhibitors are available in clinical practice. While the amount of information on their efficacy compared to vitamin K antagonists in different indications is currently growing [1], there are still several areas of uncertainty regarding their interaction in other syndromes such as thyrotoxicosis. A 68-year-old man with a history of recurrent atrial fibrillation was admitted for dyspnea, fatigue on ordinary effort and peripheral edema. The patient had previously undergone implantation of a pacemaker due to sinus node dysfunction. He was also affected by non-insulin dependent diabetes mellitus, and arterial hypertension. Before hospitalization, his ongoing therapy was dabigatran 110 mg BD, amiodarone 200 mg OD, valsartan 160 mg OD, amlodipine 5 mg OD, rosuvastatin 10 mg OD and metformin 500 mg BD. At admission, the patient was in atrial fibrillation rhythm with a heart rate of 110 b.p.m. Echocardiography showed preserved left ventricular function (49 %) in presence of an enlarged atrium (in four chambers projection: left atrium 45 9 79 mm, right atrium 33 mm), mild to moderate mitral valve insufficiency, and moderate tricuspid regurgitation. In addition to a NT-proBNP of 938 pg/ml and a normal value in international normalized ratio (INR), prothrombin time (PT) and activated partial thromboplastin time (aPTT), the biochemical tests showed a thyrotoxicosis pattern (TSH 0.01 lIU/ml, fT3 5.44 pg/ml and fT4 36.3 pg/ml). The diagnosis of a type 2 amiodarone-induced thyrotoxicosis was supported by the echographic pattern of destructive thyroiditis, and was treated with prednisone 25 mg OD, obtaining a progressive clinical improvement. In about a month, the patient complained of an onset of sleeplessness and diarrhea. These symptoms were attributable to thyrotoxicosis. Moreover, he noticed dabigatran capsules fully formed in the stool (three episodes in the last week before the admission). Therefore dabigatran was discontinued, and enoxaparin therapy (8000 UI s.c. BD) was started. Other causes of malabsorption, as celiac disease or pancreatic dysfunction, were excluded. Atrial fibrillation is the most common cardiac dysrhythmia, and is associated with the risk of cerebral thromboembolism, development of heart failure and increased mortality [1]. To prevent these complications, a prophylactic antidysrhythmic therapy is recommended, adding, when indicated, oral anticoagulants [1]. Amiodarone is a iodine-rich drug widely used prevent or cure cardiac dysrhythmias. Nowadays the numerous side effects of amiodarone on non-cardiac organs are well known: for example, it can induce cytotoxic effects in the thyroid gland [2] with subsequent hypoor hyper-thyroidism. The main symptoms of thyroid hyper-function are hyperactivity, tachycardia (including atrial fibrillation), diarrhea (due to acceleration of intestinal transit), fatigue, weight loss, and sweating [3]. Among NOACs, dabigatran is produced in capsules coated with hydroxypropyl methylcellulose to allow the intestinal absorption of the prodrug (dabigatran etexilate) [4]. The capsules should be swallowed whole. Breaking, & Francesco Sbrana francesco.sbrana@ftgm.it

Is recombinant human TSH as effective as thyroid hormone withdrawal in the detection and treatment of metastatic differentiated thyroid cancer

Evaluation of: Van Nostr D, Khorjekav GR, O’Neil J et al. Recombinant human thyroid-stimulating hormone versus thyroid hormone withdrawal in the identification of metastasis in differentiated thyroid cancer with 131I planar whole body imaging and 124I PET. J. Nucl. Med 53(3), 359–362 (2012). In a recent article, Van Nostrand et al. compared two methods of patient preparation, that is, recombinant human thyroid-stimulating hormone and thyroid hormone withdrawal, for the detection of metastasis in patients previously treated for differentiated thyroid cancer, using both 131I whole-body imaging and 124I positron emission tomography. The major finding of this prospective study was that the number of patients and the number of foci for patient positive at 131I whole-body imaging and 124I PET performed after thyroid hormone withdrawal was significantly higher when compared with that related to patients prepared with recombinant human thyroid-stimulating hormone.

Tecniche diagnostiche per lo studio della tiroide

La tiroide e una ghiandola endocrina situata nella regione anteriore del collo, subito al davanti e lateralmente alla laringe e ai primi anelli tracheali; e costituita da due lobi ognuno dei quali misura approssimativamente 4 cm in lunghezza e 2 cm in spessore e larghezza, fra loro uniti (in corrispondenza del primo o del secondo anello tracheale) da un segmento trasversale chiamato istmo, che misura 2 cm in larghezza e altezza e 0,5 cm in spessore. In circa il 10% dei casi e possibile inoltre osservare un sottile prolungamento ghiandolare che origina dall’istmo, il cosiddetto lobo piramidale (o di Morgagni), quale residuo del dotto tireoglosso. La tiroide e rivestita da una capsula fibrosa connessa alla fascia pre-tracheale, per cui durante l’atto di deglutizione la ghiandola si muove contestualmente alla cartilagine cricoide. L’unita funzionale della tiroide e il follicolo (50–500 μm di diametro), la cui parete e costituita da una fila di cellule cubiche (cellule follicolari o tireociti) che poggiano sulla membrana basale e delimitano una cavita detta follicolare in cui e contenuta la colloide, formata esclusivamente da tireoglobulina, che costituisce la forma di deposito degli ormoni tiroidei. Le cellule parafollicolari (o cellule C), di maggiori dimensioni, si trovano a ridosso della membrana basale e sono deputate alla produzione della calcitonina.