Multicenter evaluation of analytical performances of platelet counts and platelet parameters: Carryover, precision, and stability.

INTRODUCTION: The correctness of the results of automated platelet analysis is still highly debated. The aim of this multicenter study, conducted according to international guidelines, was to verify the analytical performance of nine different types of hematology analyzers (HAs) in the automated platelet analysis. METHODS: Four hundred eighty-six peripheral blood samples (PB), collected in K3 EDTA tubes, were analyzed by ABX Pentra, ADVIA2120i, BC-6800, BC-6800 Plus, Cell-DYN Sapphire, DxH800, XE-2100, XE-5000, XN-20 with PLT-F App. Within-run imprecision and between-run imprecision were carried out using PB and material control, respectively. The carryover, low limit of quantification (LoQ), and the PB stability were evaluated. RESULTS: The carryover was absent for all HAs. The LoQ of PLT ranged between 2.0 (Cell-Dyn Sapphire) and 25.0 × 109 /L (ADVIA 2120i), while immature platelet fraction (IPF) ranged between 1.0 (XN-20) and 12.0 × 109 /L (XE-5000). The imprecision (%CV) increases as the platelet count decreases. No HAs showed desirable CVAPS for PLT counts less than 50.0 × 109 /L, with the exception of Cell-DYN Sapphire (CV 3.0% with PLT-O mean value of 26.7 × 109 /L), XN-20 (CV 2.4% with PLT-F mean value of 21.5 × 109 /L), and BC-6800 Plus (CV 1.9% with PLT-O mean value of 26.5 × 109 /L). The sample stability ranged between under two hours for MPV by ADVIA2120i and 8 hours for other PLT parameters and HAs. CONCLUSION: The findings of this study may provide useful information regarding carryover, precision, and stability of platelet counts and parameters, especially in thrombocytopenic samples. Moreover, the stability of sample for platelet analysis is conditioned by the HA and by temperature and storage time.

Photo-isomerisation of alkenyl complexes of platinum(II): structural, spectroscopic, kinetic and computational investigations.

In this work UVA and blue light have been used to study photo-isomerisation about the C=C double bond in complexes of the type [PtCl(-CH=CHAr)(tmeda)] [Ar = C6H5, (E)-2a; 4-CH3O-C6H4, (E)-2b; 3-NO2-C6H4, (E)-2c; and 3-CH3O-C6H4, (E)-2d]. The progress of the reaction has been monitored by NMR spectroscopy following irradiation of the NMR sample. The NMR data have been complemented with X-ray diffractometric analysis of compounds (E)-2a-c and (Z)-2a. The kinetic data clearly indicate that a monomolecular mechanism is operating with the energy of the irradiating light influencing the rate of isomerisation but not the equilibrium composition, which is only slightly in favour of the Z isomer. DFT and TD-DFT theoretical investigations have been carried out to elucidate the nature of the main electronic transitions in the UV-Vis region and the mechanism of the photo-isomerisation reaction appears to proceed through a C=C bond twist process similar to that involved in purely organic molecules such as stilbene. In the Z isomer, one ortho proton of the phenyl group can come close to platinum (Pt···H(ortho) distance of 2.632 Å in (Z)-2a). In the case of 2c, the difference in chemical shift between the two ortho protons varies from 3.30 ppm in the Z isomer, where interaction with Pt is possible, to 0.60 ppm in the E isomer, where such interaction cannot take place. The analysis of the DFT orbitals indicates that the most shifted H(ortho) is that with a greater positive charge, pointing to an H-bond type of interaction.

[Video-assisted thyroidectomy with minimally invasive central cervicotomy: initial experience in an endocrine surgery division]. / Tiroidectomia videoassistita con minicervicotomia centrale. Esperienza iniziale in una Divisione di Endocrinochirurgia.

Minimally invasive video-assisted thyroidectomy, a recently developed technique, has been shown to be feasible and safe. Nevertheless, to obtain the best results, the surgeon should be well trained in endoscopic surgery. We attempted to answer the question whether an endocrine surgery division with no previous experience in endoscopic neck surgery could easily import the new technique. The inclusion criteria were nodules < or = 3.5 cm diameter or thyroid lobe volume less than 15 ml, and no thyroiditis or previous neck surgery. Suspect malignant nodules were excluded. The procedure was carried out through a 20 to 30 mm central neck incision, with external retraction and no neck insufflation. The vessels were ligated or closed by means of clips. From March 2004 to March 2005, 127 thyroidectomies were performed, of which 36 were thyroid lobectomies. Of these, 12 lobectomies by minimally invasive video-assisted thyroidectomy were performed for monolateral goiter (4 left, 8 right). There were no intraoperative complications. No recurrent laryngeal nerve palsy or permanent hypoparathyroidism occurred. The mean operative time was 74.4 min (median: 70; range: 45-115). The results, in terms of patient comfort, reduced postoperative pain and cosmetic quality were excellent. The technique allowed careful assessment of the inferior and superior laryngeal nerve. Thorough haemostasis was aided by the magnification of the image and optimal illumination. The learning curve appeared short, owing probably to previous experience in conventional endocrine surgery and the closer similarities of minimally invasive video-assisted thyroidectomy to enhanced-view conventional surgery than to laparoscopic surgery. In our experience the clinical impact was limited as a result of the small percentage of patients fulfilling the strict inclusion criteria.