In vivo 19F MR imaging and spectroscopy for the BNCT optimization.

The aim of this study was to evaluate in vivo the boron biodistribution and pharmacokinetics of 4-borono-2-fluorophenylalanine ((19)F-BPA) using (19)F MR Imaging ((19)F MRI) and Spectroscopy ((19)F MRS). The correlation between the results obtained by both techniques, (19)F MRI on rat brain and (19)F MRS on blood samples, showed the maximum (19)F-BPA uptake in C6 glioma model at 2.5h after infusion determining the optimal irradiation time. Moreover, the effect of L-DOPA as potential enhancer of (19)F-BPA tumour intake was assessed using (19)F MRI.

The postmenopausal ovary is not a major androgen-producing gland.

It is currently believed that the postmenopausal ovary remains a gonadotropin-driven, androgen-producing gland. However, the adrenal contribution to circulating androgen levels may explain some conflicting results previously reported. In addition, the steroidogenic potential and gonadotropin responsiveness of the postmenopausal ovary have not been recently reassessed. Plasma T, bioavailable T, free T, androstenedione (Adione), and dehydroepiandrosterone sulfate levels were measured in postmenopausal or ovariectomized women with complete adrenal insufficiency, compared with women with intact adrenals. A stimulation human chorionic gonadotropin test (on d 0, 3, and 6) was performed in postmenopausal women with adrenal insufficiency. Dexamethasone was administered for 4 d in postmenopausal women with intact adrenals. Intraovarian T and androstenedione were also measured in homogenates of ovarian tissue from postmenopausal women. Immunocytochemistry was performed on postmenopausal ovaries and premenopausal controls to detect the presence of steroidogenic enzymes (P-450 aromatase, P-450 SCC, 3beta HSD, and P-450 C17) and gonadotropin receptors. Plasma androgen levels were below or close to the limit of the assay in all women with adrenal insufficiency. They were similar in postmenopausal and oophorectomized women with normal adrenals. No hormonal changes were observed after human chorionic gonadotropin injections in women with adrenal insufficiency. In contrast, a dramatic decrease of all steroids was observed after dexamethasone administration in postmenopausal women with intact adrenals. Intraovarian T and androstenedione levels were negligible in postmenopausal ovarian tissue. P-450 aromatase was absent from the 17 ovaries studied, and the enzymes for androgen biosynthesis were either absent (n = 13) or present in very low amounts (n = 4). In all the postmenopausal ovaries, FSH and LH receptors were completely absent. In the absence of adrenal steroids, postmenopausal women have no circulating androgens. This result is consistent with the immunocytochemical studies showing the almost constantly absent steroidogenic enzymes and LH receptors in the postmenopausal ovary. Thus, the climacteric ovary is not a critical source of androgens. The arrest of androgen secretion after menopause may impact significantly on women's health.

[Round Table "Role of scientific and professional associations in proposing occupational health programs to regional and national authorities]. / Tavola Rotonda "Ruolo propositivo delle associazioni scientifiche e professionali verso gli organi di governo locale e centrale".

The six participants at the round table were experts in the field of Occupational Prevention working respectively in the Ministry of Health, the National Institute of Occupational Health, the Health Council of Lombardy, the Law-court of Milan, the CGIL Trade Union, and the Lombard Employers Association. All the participants were of one mind on the establishment of working groups within the scientific and professional associations with the aim of preparing and updating occupational exposure limits, diagnostic records, programs of biological and environmental monitoring, etc. Moreover, they stressed the need to establish permanent cooperation between the scientific and professional associations and the regional and national health authorities. These associations can make an important contribution, for example in preparing new preventive guidelines, because they can act faster than the legislative bodies. The validity of these proposals was confirmed by the judge attending the round table. He stated that technical standards proposed by groups of professionals or by scientific associations have usually been taken into consideration when relevant legislation has been applied.

[Point of view of the magistrate]. / Il parere del magistrato.

The authors agrees to the three associations proposal that is useful and juridically correct. He considers all the situations that make the sanitary surveillance mandatory and assert the need of a common interpretation of the law that must fallow the new pattern pointed out by the legislative decree 626/94, respecting the European Community directives. Consequently the rules provided by the decree 303/56 should be interpreted in the light of the legislative decree 626/94 principles.

[Experimental tracheal transplantation. Literature review and proposal of an original surgical technique]. / Il trapianto sperimentale di trachea. Revisione della letteratura e proposta di tecnica originale.

The reconstruction of the trachea after wide resections remains a critical surgical problem. Our aim has been to replace trachea with a tissue easy to be vascularized, that permits a simple reconstruction, not requiring an immunosuppressive regimen. We have used a segment of cryopreserved aorta. In the first phase the thoracic aorta of 10 rabbits was excised obtaining 20 segments that were cryopreserved. Ten segments were implanted in the omentum of 10 rabbits that were sacrificed on postoperative day 7, 14 and 21. The histologic examination of the grafts showed the presence of neovascularization after 7 days with obliteration of the lumen by fibroblasts after 14 days. In the next phase the cryopreserved aorta replace an excised segment of trachea. The survived animals were sacrificed 7 and 14 days after the operation. The histologic examination showed the neovascularization of the graft and the absence of rejection.

S2 triggered gated blood pool imaging for assessment of diastole.

Evaluation of diastolic function using ECG-Gated Blood Pool (EGBP) imaging is limited by inaccurate reproduction of the ventricular volume curve during diastole. Gating to an end-systolic event may reduce the influence of heart period variability, improving the fidelity of this curve during diastole. Heart Sound-Gated Blood Pool (HSGBP) imaging was employed to initiate acquisition at the Second Heart Sound (S2) using a previously reported Heart Sound Gate, and an accelerometer. Seven patients underwent EGBP imaging at 24 and 56 frames per second (fps), and HSGBP imaging at 24 fps. Utilizing EGBP imaging a mean ejection fraction (EF) of 54% was obtained at 24 fps, with HSGBP imaging yielding 53%. EF obtained by HSGBP and EGBP imaging correlated closely (r = 0.96, p < .002). The mean EF during 56 fps EGBP imaging was greater at 67%, consistent with previous reports. Additionally, peak filling rates by HSGBP and EGBP imaging correlated well (r = 0.95, p < .02). The fidelity of the diastolic ventricular volume curves for HSGBP and EGBP methods were comparable in four patients, and superior with HSGBP imaging in four patients. In conclusion, HSGP imaging is a feasible method for acquisition of the ventricular volume curve, and may assess diastolic function indices with greater accuracy. Further investigation of this application is warranted.