Cytosolic calcium and hemorheological patterns during arterial hypertension.

Hypertension can be considered as a progressive ischaemic syndrome interesting micro- and macrovasculature. In hypertensives it is possible to observe a link between an increase in peripheral resistance and blood viscosity, and a decrease in red blood cell (RBC) deformability. It is important to underline the link between the increase of blood viscosity, the decrease of RBC deformability and the cytosolic calcium level, which is related to the ischaemic syndrome in hypertension. The aim of this study was to evaluate the level of Ca++ and its possible correlation with hemorheological patterns during arterial hypertension. Two groups were studied: Group 1 consisted of 18 mild hypertensives (11 males and 7 pre-menopausal females, aged 39 +/- 3 years). This group was of medium risk according to WHO and ISH (1999) with no other pathologies apart from peripheral occlusive arterial disease II stage type A. Group 2 was made up of 14 healthy subjects (9 males and 5 females, aged 34 +/- 4 years). The intraerythrocytic cytosolic calcium was evaluated using a fluorescent marker FURA 2/AM (Calbiochem). The following hemorheological parameters were also assessed using the new Laser assisted Optical Rotational Red Cell Analyzer (LORCA) according to the Hardeman method (1994): RBC deformability-Elongation Index (EI), RBC aggregability- aggregation half time (t 1/2). The data obtained showed that compared to the control group the hypertensives had a significantly higher level of intraerythrocytic cytosolic calcium (p < 0.01), plus a significant decrease in EI and t 1/2 evaluated using LORCA. We also observed a significant correlation (p < 0.01) between an increase in Ca++ and a decrease in EI in the hypertensive patients. Moreover our study revealed a significant correlation between the increase in intraerythrocytic Ca++ and the t 1/2 decrease. The evaluation of the hemorheological patterns and cytosolic calcium could explain the impairment in peripheral perfusion and oxygenation in hypertensive patients and could provide a good model for a better evaluation and treatment of microvasculature perfusion in subjects with essential and complicated hypertension.

Tissular oxygenation and erythrocyte deformability in haemodialyzed patients using different dialytic membranes.

We studied the effect of some dialytic membrane on tissular oxygenation (TO) and erythrocyte deformability (ED). Sixteen patients (10 M and 6 F, aged 59 +/- 12 years) have been submitted to bicarbonate dialysis (BD) and subdivided into four groups (GR) of 4 patients each: GR 1 (hemophan membrane, 35 BD), GR 2 (polyacrylonitrile, PAN AN 69, 42 BD), GR 3 (polysulphone, 38 BD) and GR 4 (polycarbonate, 37 BD). The TO has been detected with the transcutaneous oxygen pressure (Tc pO2) using a transcutaneous oxymeter and the ED has been evaluated with the EMI (Erythrocyte Morphometric Index), which results from the ratio between deformable erythrocytes (bowl shape) and rigid erythrocytes (discocyte shape), for every 100 red cells fixed in vitro with 0.3% glutaraldehyde. The ED was also evaluated using a laser instrument: Laser Optical Rotational Cell Analyser. During BD was observed a significant decrease of Tc pO2 in the 1st hour only in the 1st and 2nd GR and, in contrast with results obtained in the 3rd and 4th GR, in the same GRs the EMI showed a significant reduction of ED at the end of BD. Finally the LORCA results, showing a significant decrease of ED only in the 1st and 2nd GR, confirmed the data obtained with EMI. In conclusion, our study has suggested that hemophan and PAN AN 69 are less biocompatible than polysulphone and polycarbonate membranes according to effects on ED and TO.

Clinical and therapeutic aspects of renal amyloidosis.

Renal amyloidosis is not a frequent disease: its annual frequency is approximately 2.5-2.8% of all renal biopsies. Individual cases are normally rare and for this reason clinical findings and therapeutic results obtained by clinical multicentre studies are well considered. This review describes the clinical and therapeutic aspects of renal amyloidosis and refers particularly to the results obtained by the Italian Study Group for renal amyloidosis and by the multicentre Italian study protocol for AL amyloidosis.