The present study was aimed at verifying the occurrence, if any, of in vivo oxidative DNA damage in FA homozygotes, their parents and siblings. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) was measured, by HPLC/EC, in DNA from circulating blood leucocytes from FA homozygotes and their relatives and compared with a group of paediatric and adult healthy subjects. The population studied consisted of: (i) 15 FA homozygotes; (ii) 24 FA heterozygotes; (iii) 11 siblings. The 8-OHdG level in FA homozygotes was significantly higher with respect to age-matched controls, with a mean level of 33.3 +/- 6.8 (mean +/- SE) and 3.9 +/- 0.26 8-OHdG/10(5) dG respectively. The FA parents (heterozygotes) also displayed higher 8-OHdG levels relative to controls. The release of hydroxyl (.OH) and .OH-like radicals from leucocytes was determined by luminol-dependent chemiluminescence (LDCL) in a subgroup of FA homo- and heterozygotes, showing a very large in vivo formation of non-superoxide radicals. Chromosomal instability was also measured in the FA population. When relating either 8-OHdG or LDCL levels to spontaneous or diepoxybutane-induced chromosomal instability (S-CI and DEB-CI respectively), a significant correlation was observed between the 8-OHdG, LDCL and S-CI data. Within families a positive association was found between 8-OHdG levels in homozygotes and their related heterozygotes, suggesting segregation of the genetic defect(s) underlying the abnormal oxidative metabolism. The present study provides evidence for an in vivo pro-oxidant state in FA, in terms of excess formation of .OH and .OH-like radicals, and of DNA hydroxyl adducts. This finding appears to be shared by homozygotes and, to a lesser extent, by heterozygotes.

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The aim is to determine the monocyte count performance of the Bayer Diagnostics ADVIA120 and Coulter LH 750 automated haematology analysers and the results obtained by these two instruments were compared with those provided by Becton Dickinson FACScan flow cytometer using the combination of CD45/CD14 MoAb. Linearity and imprecision were also evaluated. The linearity of both instruments was good. Coulter LH 750 showed better precision (4.3%) than ADVIA 120 (9.0%) both within and between batch. A significant correlation (r = 0.973) was found between the LH 750 and the flow cytometry method, while a modest one was observed between the latter and the ADVIA 120 (r = 0.880). When comparing the percentage of monocytes by means of one-way anova and Tukey test, it was found that the LH 750 provided the closest results in comparison with flow cytometry, with no statistical difference between the means (mean difference MO% = 0.6); however the difference was statistically different between the ADVIA 120 and flow cytometry (mean difference MO% = -4.06). These data were confirmed by Altman-Bland and Deming regression analyses.

The Abbot Cell-Dyn Sapphire is a new generation haematology analyser. The system uses optical/fluorescence flow cytometry in combination with electronic impedance to produce a full blood count. Optical and impedance are the default methods for platelet counting while automated CD61-immunoplatelet analysis can be run as selectable test. The aim of this study was to determine the platelet count performance of the three counting methods available on the instrument and to compare the results with those provided by Becton Dickinson FACSCalibur flow cytometer used as reference method. A lipid interference experiment was also performed. Linearity, carryover and precision were good, and satisfactory agreement with reference method was found for the impedance, optical and CD61-immunoplatelet analysis, although this latter provided the closest results in comparison with flow cytometry. In the lipid interference experiment, a moderate inaccuracy of optical and immunoplatelet counts was observed starting from a very high lipid value.

Liver cirrhosis leads to a protido-synthetic impairment that alters the levels of blood clotting factors and haemostasis. The aim of this study was to assess the alterations of haemostatic parameters in the evolution of liver cirrhosis scored according to Child’s classification, with Pugh’s modifications. Thirty-seven patients suffering from alcoholic and non-alcoholic liver cirrhosis, representing stages A5, A6, B7, B8 and C10, were tested for the main blood clotting parameters, i.e. prothrombin time, factor VII, partial activated thromboplastin time, fibrinogen, plasminogen, α₂-antiplasmin and physiological inhibitors [antithrombin III (ATIII), protein C (PC), protein S (PS)]. No variations were observed between substages A5 and A6 in any of the parameters, except for coagulation inhibitor levels. Most parameters showed a progressive decrease in stages B and C of the disease. The most significant alterations were found in the physiological coagulation inhibitors, with a sharper decrease in PC and AT III level and a lesser decrease in the level of PS through stages A5 and B8: this evidence could assume an important biological and diagnostic significance.

We investigated the effect on human platelet aggregation of the naturally occurring quinone/hydroquinone couple, avarone and avarol. Avarone exerted antiplatelet activity both on platelet-rich plasma and, to a greater extent, on washed platelets. The quinone inhibited the platelet aggregatory process with all the agonists used. The highest inhibitory potency occurred with arachidonic acid or A23187 as stimulating agents. In the case of agonists such as adenosine 5' diphosphate, platelet-activating factor or U46619, the antiaggregatory effect was more pronounced on the second wave. Inhibition of the aggregatory process paralleled thromboxane B2 formation. Avarol also exerted antiplatelet activity, even though its inhibitory potency was much lower than that of avarone.