[Radio-guided surgery in primary hyperparathyroidism: clinical indications and technical procedure]. / La chirurgia radioguidata nell'iperparatiroidismo primitivo. Indicazioni cliniche e procedura tecnica.

AIM: The purpose of the present study was to assess the utility of the intraoperative gamma probe technique in a group of 128 patients suffering from primary hyperparathyroidism (PH). METHODS: In view of surgery, these patients were homogeneously subjected to a diagnostic protocol comprising double tracer scintigraphy ((99mTc)-Pertecnetate/(99mTc)-MIBI) and neck echotomography, carried out in a single session. They were then all operated on by the same surgical team. RESULTS: In 97 patients with scintigraphic and echographic evidence of single parathyroid enlargement and normal thyroid gland, mini-invasive radio-guided surgery (MRS) was planned. In 94 of these 97 patients (96%) MRS was carried out successfully by removal of a single parathyroid adenoma (PA) through a small cutaneous incision of 2-2.5 cm; in the remaining 3/97 patients (3.1%), it proved necessary to convert to bilateral surgical exploration of the neck following intraoperative diagnosis of a parathyroid carcinoma in 2 cases and of multiglandular pathology (MGP) suggested by the persistence of elevated values of intraoperative parathormone (PTH) in 1 case. It should be pointed out that the use of IGP enabled us to carry out limited surgical exploration in 18 of 23 patients who had previously undergone operation on the thyroid and/or parathyroids. In a second group of 31 patients with presumed preoperative diagnosis of MGP (5 cases) or nodular goitre concomitant with PH (26 cases), IGP was used in the course of standard bilateral surgical exploration of the neck and enabled us to locate: an ectopic parathyroid gland in the thymus in 1 case of MGP, a PA in the deep levels of the neck in 2 cases with goitre and an ectopic PA at the bifurcation of the carotid in 1 other case with goitre. It should however be specified that in certain other patients with goitre it proved difficult intraoperatively to distinguish thyroid nodes from a PA adhering to the thyroid. CONCLUSIONS: On the basis of the data to emerge from the present study we can conclude that: 1) in patients with PH presenting a scintigraphic and echographic picture indicating single PA and normal thyroid with high probability, the IGP technique proves effective in carrying out an MRS; 2) 37 MBq of (99mTc)-MIBI are an adequate dose for the correct performance of MRS; 3) a rapid intraoperative dose of PTH is to be recommended so as to confirm complete removal of the hyperfunctioning parathyroid tissue; 4) MRS may be employed successfully also in those patients previously subjected to thyroid or parathyroid surgery for the purpose of limiting the surgical trauma connected to reintervention and, therefore, to reducing the risk of complications; 5) IGP would not appear to be recommendable in patients with PH and concomitant goitre, with the possible exception of ectopic PA.

The interaction of tributyllead with lysosomes from rat liver.

The interactions of tributyllead with lysosomes from rat liver have been studied. It results that the organometal compound induces a fast alkalinization in energized lysosomes. The interpretation is that the compound is a potent proton carrier. This function could explain the toxicity, in particular at neurological level of the compound.

An in vitro study on the toxic effects of nonylphenols (NP) in mitochondria.

This paper is focused on alkylphenols, compounds which are formed by the biodegradation of polyethoxilatedalkylphenols detergents. Our experiments show that alkylphenols act not only as detergents, but also as uncouplers of the oxidative phosphorylation. This effect, can be observed at very low doses, thus suggesting that the preferential target of nonylphenols in living organisms are mitochondria.

Heparin-induced structural and functional alterations of bovine trypsin.

To investigate the mechanism whereby heparin can modulate the activity of serine proteinases, bovine trypsin was chosen as reference and treated with heparin at 10, 100 and 200 micrograms/ml, in buffer solvents, with and without incubation at 37 degrees C. Heparin caused rapid, buffer- and pH-dependent decrease in trypsin solubility due to the generation of insoluble fragments from proteinase. Desalting treatments variously restored solubility by removing insoluble material. UV absorption and fluorescence emission spectra revealed significant heparin-induced conformational alterations in the trypsin molecule, the maximal effect being apparent at a proteinase-to-heparin molar ratio ranging from 1.6 to 1.0. The involvement of the catalytic sites of trypsin by heparin was further confirmed by the significant reduction in the difference absorption spectra of proflavine. Both proteolytic and esterolytic activities of trypsin were shown to be markedly decreased by heparin, especially after 5 h incubation at 37 degrees C. However, when the proteolytic and esterolytic activities of trypsin were measured on fresh solutions not submitted to desalting treatments, variable activation instead of inhibition of both activities was observed in the presence of heparin, this effect waning spontaneously in time or after desalting treatment. The paradoxical increase in functional activities was not inhibited by soybean trypsin inhibitor and was accompanied by denaturation and fragmentation of the proteinase as demonstrated by spectroscopic analyses and SDS-PAGE of fresh solutions. The results obtained indicated that heparin causes a rapid, time- and temperature-dependent conformational alteration of trypsin with irreversible denaturation and degradation of the proteinase. The underlying mechanism appears to be heparin-catalyzed oxidative degradation of trypsin due to liberation of oxygen radicals which are also responsible for the temporary increase in catalytic functions.