Comparison of platelet-derived growth factor prepared from release products of fresh platelets and from outdated platelet concentrates

Treatment of synaptic membranes from rat brainstem and spinal cord with the nonionic detergent Triton X-100 at 1-10 microliters/mg protein caused a marked increase in glycine receptor (3H)strychnine binding expressed per mg of residual membrane protein. The effect was maximal (220 +/- 6% of control) at 5 microliters Triton/mg protein, while higher concentrations caused progressive loss of strychnine binding ability of membranes (27 +/- 6% at 25 microliters Triton/mg protein). The increase in strychnine binding caused by low Triton X-100 reflected an increase in membrane Bmax, the kD being unaffected by the treatment. The affinity of glycine analogues for receptor sites was not appreciably affected by the detergent either. The findings suggest an enrichment of the synaptic membrane preparation in glycine receptors, caused by the solubilization by Triton of membrane constituents not related to the receptor sites.     

Results of a new platelet function test in various clinical diseases and in preserved blood]

In healthy persons, patients with thrombocytopenia and patients with arterial disturbances of blood flow with and without administration of Falithrom the pressure recording was carried out after the combined aggregation and adhesion of thrombocytes. The reaction time particularly observed after administration of ADP revealed marked differences in the groups examined, likewise the maximal pressure amplitude in front of the pumped through filter. When Falithrom was administered the thrombocyte functions were clearly impaired. The reduction of the capacity of platelets to obstruct filter pores can impressively be proved even in those thrombocytes stored in ACD-AG-plasma.     

The effect of additional follow-up and accrual on survival time data

A method called partial completion is proposed for predicting the gain in precision of the Kaplan-Meier survival curve associated with additional follow-up and accrual. This is accomplished by using the initial data to predict the numbers of patients who would be at risk at the observed death times by the end of the proposed second follow-up period. A consistency result ensures that the predictors will be accurate in large samples while simulation results suggest that the predictors are accurate with moderate sample sizes. The procedures are applied to a bone marrow transplant study and the Channing House data set.     

The effect of stabilizer composition on the thrombocytes and thrombocyte function in stored whole blood. II. Results of the thrombocyte spreading test]

The behaviour of thrombocyte spreading in ACD, AcD-A and AcD-AG stabilized blood was examined in 18 apparently healthy test persons for a storage period of 9 days. Due to an improved energy metabolism of thrombocytes the addition of adenin or guanosin respectively in ACD stabilized blood will cause the thrombocyte spreading to be widely preserved during storage.     

Effect of temperature and storage time on cellular analysis of fresh pleural fluid samples

L. Antonangelo, F. S. Vargas, M. M. P. Acencio, A. P. Corá, L. R. Teixeira, E. H. Genofre and R. K. B. Sales
Effect of temperature and storage time on cellular analysis of fresh pleural fluid samples Objective: Despite the methodological variability in preparation techniques for pleural fluid cytology, it is fundamental that the cells should be preserved, permitting adequate morphological classification. We evaluated numerical and morphological changes in pleural fluid specimens processed after storage at room temperature or under refrigeration. Methods: Aliquots of pleural fluid from 30 patients, collected in ethylenediaminetetraacetic acid‐coated tubes and maintained at room temperature (21 °C) or refrigeration (4 °C) were evaluated after 2 and 6 hours and 1, 2, 3, 4, 7 and 14 days. Evaluation of cytomorphology and global and percentage counts of leucocytes, macrophages and mesothelial cells were included . Results: The samples had quantitative cellular variations from day 3 or 4 onwards, depending on the storage conditions. Morphological alterations occurred earlier in samples maintained at room temperature (day 2) than in those under refrigeration (day 4). Conclusions: This study confirms that storage time and temperature are potential pre‐analytical causes of error in pleural fluid cytology.     

Leaching of plasticizers from and surface characterization of PVC blood platelet bags.

The leaching of phthalate plasticizers from four types of blood platelet bags was investigated. The anticoagulant solutions used in the blood collection bags had pH values of 5.64 +/- .04 and contained no detectable amounts of phthalates. Platelet bag materials from each bag were soaked in normal salines for up to 5 days. The salines were tested for the leached phthalates from the bags but none could be found. However, di-(2-ethylhexyl) phthalate (DEHP) leached out of the PL-146 and Terumo bags into bovine calf serum used for soaking the bag materials. There was an increase in the amount of DEHP leached from about 1.1 mg at the end of one day to about 3.3 mg per gm of bag material at the end of a five day extraction with the serum. In PL-732 sets, a platelet bag made of a specialty polyolefin, the amount of DEHP leached out was less than 0.02 mg per g of bag material. CLX bags, which contained tri-(2-ethylhexyl) trimelliate (TETM) as a plasticizer, showed a negligible amount of it leaching into the calf serum. Infra-red spectra showed that PL-146 bags had been coated with a layer of a fatty acid amide while the Terumo bags contained a layer of a silicone fluid on their inner surfaces. CLX bags showed a coating of stearates, which were probably soaps of calcium or zinc. Scanning electron microscopy (SEM) showed that the inner surfaces of each brand of the bag were distinctly different morphologically. The two PVC bags were very similar whereas the surfaces morphology of PL-732 was rougher. Terumo bag had a different surface morphology than those of the other bags whereas the CLX bags had a very regular surface pattern. The exact significance of the surface morphology is not certain but excessively rough surfaces may not be desirable for the bags.     

The effect of pedal rate and time of day on the time to exhaustion from high-intensity exercise

The aim of this study was to examine the supposed influence of pedal rate on the diurnal fluctuation of the time to exhaustion from high-intensity exercise. Eleven male cyclists performed three tests at 06:00 h and three at 18:00 h at a free pedal rate (FPR) and two imposed pedal rates (80% and 120% of the FPR). They performed the tests until exhaustion using a power output corresponding to 95% maximal power (Pmax). Time to exhaustion, rectal temperature, oxygen consumption (.VO2), M. quadriceps, vastus medialis, M. biceps femoris electromyographic Root Mean Square activity rise (RMS slope), and blood lactate concentration were measured. The mean time to exhaustion recorded at 18:00 h (270.6+/-104.8 sec) was greater than at 06:00 h (233.9+/-84.9 sec). The time to exhaustion was significantly greater when the pedal rate was imposed at 80% versus 120% FPR. The blood lactate concentration and absolute core temperature at the point of exhaustion were significantly higher during tests done at 18:00 h. There was no diurnal variation in core temperature increase, .VO2, and RMS slope. The time-of-day effect for every variable did not depend on pedal rate. Diurnal variations in maximal aerobic endurance cannot be explained by a change in aerobic metabolism or in muscular fatigue. The origin of the diurnal variation in the time to exhaustion is likely to lie in greater participation in anaerobic metabolism. Also, the influence of temperature on neuromuscular functioning as an explanation for the diurnal variation in performance cannot be excluded in this study. The hypothesis on the basis of which pedal rate would influence diurnal variations in time to exhaustion in cycling was not validated by this research.     

Effect of ergoline derivatives on platelet and blood vessels]

The influence of dihydrogenated ergot alkaloids on vessels and blood platelets was studied in vitro and in vivo. At low concentrations they cause contraction of isolated vein strips via a stimulation of alpha-adrenoceptors, at higher concentrations they antagonize the action of noradrenaline on arteries and veins and inhibit the adrenaline-induced platelet aggregation in vitro. In volunteers, intravenous and subcutaneous administration of dihydroergotamine (Dihytamin) caused a decrease in blood volume of the capacitance vessels and inhibition of the adrenaline-potentiated platelet aggregation "ex vivo". The selective venoconstrictor and antiaggregating effects of dihydroergotamine are utilized in the postoperative prophylaxis of thrombosis.     

Stimulatory effect of the lysosomal stabilizer, chloroquine, on the respiration and motility of fresh and aged bovine spermatozoa.

The lysosomal stabilizer and anti-malarial agent, chloroquine, stimulated the respiration and motility of fresh and aged bovine spermatozoa stored in vitro. Duplication of these effects by the phosphodiesterase inhibitors, theophylline and caffeine, suggested that enhancement of sperm activity by chloroquine may be mediated by cyclic AMP.     

The effect of microstructure on the rheological properties of blood

The micromorphic theory of Eringen is applied to study the tube flow of blood. The blood is considered to be a deformable suspension, with constitutive relations of the form of those of simple microfluids. By means of energy consideration, a relation is established between the local concentration parameter and the measure of rotationality involving both macro-and micromotions. The tube flow problem is then solved with some analyses on viscosity coefficients and boundary conditions. The results obtained indicate an integrated explanation of various important physical phenomena associated with blood flow, such as the tube size dependence of the apparent viscosity and the non-uniform concentration distribution over a tube cross section.     

The effect of neuraminidase on the relative surface charge-associated properties of rat red blood cells of different ages

Approx. 70% of the sialic acid on the rat erythrocyte surface is susceptible to cleavage by neuraminidase (Vibrio cholerae). Neuraminidase treatment results in a reduction in the partition coefficient (K) of the red cells in a charged dextran-poly(ethylene glycol) aqueous phase system and in the electrophoretic mobility of the cells. Countercurrent distribution of rat neuraminidase-treated erythrocytes, containing 59Fe-labeled mature red cells of distinct age, indicates that (a) the electrophoretic mobilities of red cells in different cavities along the extraction train increase with increasing K, as is the case with untreated erythrocytes, and (b) the cell age-related differences in surface charge-associated properties are neither eliminated nor altered by the enzyme action.     

The effect of bovine diet on Salmonella survival in synthetic abomasal fluid

Aims: To investigate the effect of diet on the survival of Salmonella in the bovine abomasum. Methods and Results: Five fistulated cows were randomly assigned to one of five diets denoted as: (i) 100% grass, (ii) grass + 5·3 kg DM concentrate, (iii) 100% grass silage, (iv) 100% hay and (v) maize/grass silage plus concentrates. Rumen fluid was harvested from each dietary treatment and inoculated with nonacid (NA) and acid‐adapted (AA) 5‐strain Salmonella cocktails. After 24‐h incubation period, Salmonella were acid challenged to synthetic abomasum fluid (SAF, pH 2·5) for 5 h to determine their resistance to low pH. The study found that the volatile fatty acids composition and the pH profile of bovine rumen fluid were significantly altered (P < 0·05) by some of the dietary treatments but not others. Regression analysis found that significantly higher numbers of acid‐adapted Salmonella survived in SAF after incubation in rumen fluid from diets 1, 2 and 4, but fewer significant differences were found between diets for nonacid–adapted Salmonella. The results suggest that the acid‐adapted cells were subjected to a higher level of cell injury than the nonadapted cells. Conclusions: Pre‐incubation in rumen fluid did influence the resistance of nonacid and acid‐adapted Salmonella to SAF but it was dependant on the dietary treatment fed to the cows. Significance and Impact of the Study: This study examined the use of diet, as a modulating factor to limit the bovine excretion of Salmonella with a view to providing a scientific basis for the design of dietary management controls in the future.     

Effect of erythropifadin on the morphofunctional characteristics of donor blood preserved for a long time

Adenine- and riboxine-containing erythropifaden has been studied for possibility to be used for restoring a functional value of erythrocytes in conserved donor blood stored for 35-49 days. Energy supply and oxygen transport function of erythrocytes are shown to get normal and their morphological composition--to get considerably improved. Besides, osmotic resistance and deformability of erythrocytes insignificantly change while concentration of riboxine in blood and that of substances with average molecular mass remain considerably high. One of the ways to remove the above shortcomings is application of hemosorbents.     

Recovery of DNA of Giardia intestinalis cysts from surface water concentrates measured with PCR and real time PCR

The most important restriction for the detection in water samples is the low concentration of Giardia intestinalis cysts, additional difficulty is the presence of PCR inhibitors. We have carried out trials in order to assess the sensitivity of semi-nested PCR and TaqMan real time PCR on the basis of DNA extracted from G. intestinalis cysts coming from spiked environmental and distilled water samples, filtrated with the use of Filta-Max^® equipment (1623 Method). Removal of inhibitors was carried out with addition of BSA in different concentrations. During the filtration and concentration of water samples, losses of cysts have been recorded. Moreover, addition of BSA to the PCR and real time PCR mix increases the sensitivity of reaction. The optimal concentration of BSA for semi-nested PCR was 15 and 20 ng/μl, whereas for real time PCR 5 ng/μl.