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[en] One of the important functions of granulocytes is the ability to respond to a chemoattractive signal by migration. The influence of radiographic contrast media (CM) on the chemoattractive properties of serum was investigated by under agarose technique for chemotaxis. No chemotactic response was seen when serum was incubated with different concentrations of CM after heat inactivation. The CM did not generate the heat stable complement split product C5a-desarg which would have resulted in a chemotactic response. Without heat inactivation all complement available in the serum was activated by the agarose in the chemotaxis assay. Low concentrations of iohexol and iodixanol brought about an increased chemotactic response relative to a reference with saline instead of CM. This may be due to activation of heat labile chemoattractants from other sources than the complement cascade. At high concentrations of all five investigated CM, a decreased number of granulocytes migrated over a shorter distance when compared with the reference, and this may be due to interactions between the CM and chemoattractants or their precursors. (orig.)
[en] The effect on red cell deformability from solutions of the ionic contrast media diatrizoate, iocarmate and metrizoate and the non-ionic metrizamide and hypertonic saline (0.5 osm) was investigated by measuring the flow rate of 10% red cell suspension (Vsub(RBC)) and of plasma (Vsub(plasma)) through Nucleopore sieves of 5 μm in diameter. By calculating the relative flow rate Vsub(rel)(Vsub(RBC)/Vsub(plasma)) the deformability of the red cell was quantified. Both the contrast media solutions and the hypertonic saline solution decreased the Vsub(rel), the indicating an increased rigidity of the red cell. The increased rigidity was due mainly to the osmotic effect. The higher the osmolality, the more the deformability was reduced. The low osmotic metrizamide induced a smaller reduction in red cell deformability compared to ionic media of high osmolality in iodine-equivalent concentration. (Auth.)
[en] In the last years, there has been a growing recognition of the importance of blood volume abnormalities in the pathophysiology of several conditions and, consequently, a growing interest of accurate and rapid volume status assessment. Accordingly, there has been a surge of interest in blood volume analysis by radioisotopic dilution technique. However, there are still some controversies about this technique, such as the use of the f-cell ratio, the errors associated with the method and the reference values. This review aims to revise and discuss the theoretical and methodological aspects of this technique and also to discuss their controversies. Furthermore, it is questioned whether red cell volume or plasma volume can be accurately estimated once the other quantity has been measured or should red cell volume and plasma volume be directly measured. As a conclusion, blood volume analysis by radioisotopic dilution technique is still valid and very useful. - Highlights: • Since the haematocrit reflects a proportion, it can be sometimes misleading. • Blood volume analysis by radioisotopic dilution technique is still valid and very useful. • The mean value of f-ratio (Hc/Hv) varies between 0.84 and 0.99, with a total range from 0.54 to 1.35. • This variation of f could cause large errors when estimating RCV or PV once the other has been measured
[en] Peripheral blood of 784 subjects working with sources of ionizing radiation was studied. They were divided in 6 subgroups challenged with different radiation load: minimal 3 ber, maximal > 90 ber. The data obtained were compared with those in a control group of 310 practically normal subjects. Statistically significant differences in reticulocyte, platelet, leucocyte, neutrophilic leucocyte and lymphocyte counts were recorded in subjects exposed to chronic low-dose radiation effects. The irradiation levels in all groups were within physiologic range. (A.B.)
[en] To evaluate the safety and clinical efficacy of percutaneous intraductal radiofrequency ablation (RFA) followed by dual stent placement in advanced malignant biliary hilar duct obstruction. Between September 2013 and August 2015, ten patients with malignant biliary hilar duct obstruction who underwent percutaneous intraductal RFA followed by dual stent placement were included in this retrospective study. Technical success, clinical success, procedure-related complications, stent patency, and patient's survival durations after treatment were investigated. Percutaneous intraductal RFA followed by dual stent placement was successful in all patients; the technical success rate was 100%. No major complications were identified. After the procedure, serum total bilirubin levels were notably normalized, and therefore, percutaneous transhepatic biliary drainage (PTBD) catheter was successfully removed in 8 patients; the clinical success rate was 80%. Four patients with stent dysfunction associated with tumor ingrowth/overgrowth underwent a repeat PTBD procedure or secondary stent insertion. Mean stent patency and survival durations were 233.8 ± 35.6 days [95% confidence interval (CI), 164.0–303.5 days] and 387.2 ± 114.6 days (95% CI, 162.6–611.8 days), respectively. Percutaneous intraductal RFA combined with dual stent placement in advanced malignant biliary hilar duct obstruction is a safe and feasible palliative treatment option
[en] The dependence of the sedimentation rate of donor blood on its percentage in the sample (the degree of its dilution with physiologic saline) ranging from 0.25 to 100% (whole undiluted blood) is investigated with digital video equipment. The ratio of the value of displacement of the sediment–supernatant boundary per time unit was taken as the blood sedimentation rate. In case of registration of different speeds of movement of this boundary in a given volume of the cuvette, their spatial averaging was performed. A substantial increase in the blood sedimentation rate was found experimentally at high levels of its dilution, and, conversely, at blood concentrations in physiologic saline solutions that are close to whole blood. At the same time, the rate of blood sedimentation decreased several times with blood content in the range of 30–50%. It was experimentally shown that variation of blood content in the physiologic saline solution over a wide range did not affect the evenness of sedimentation occurring for almost any blood concentration in the mixture. In other words, in the process of sedimentation of a single blood sample of a given dilution in the physiologic saline solution, the sedimentation rate does not change with time. The experimentally obtained results allowed to build a theoretical model of blood sedimentation for two cases: 1) sedimentation of free erythrocytes (highly diluted blood) and 2) sedimentation of erythrocyte aggregates (almost undiluted blood, up to whole blood). The originality of the model comes from the proposition to consider the sedimentation of cells and/or their aggregates as a collective effect, and not in the traditional form of sedimentation of individual particles or particles interacting with each other. This model gives a satisfactory agreement with experimental laws with the use of certain empirical constants. The study is useful for understanding the process of erythrocyte sedimentation.
[en] Influence of vertical magnetic fields of ± 1200 T2m-1 on the sedimentation of red blood cells were examined. The sedimentation rate changes 10-20 % by application of the magnetic fields. This result is interpreted in terms of the magnetic force acting on the cells.