Pseudomonas aeruginosa phage lysate as an immunobiological agent. 1. Selection of Pseudomonas aeruginosa clinical strains for phage lysate preparation.

A total of 2087 Pseudomonas aeruginosa isolates collected during the period 1994-1997 were used as starting material. Out of 1704 in-patient isolates, 299 strains were selected for the preparation of phage lysates but only five strains provided stable lysates, i.e., maintained the ability to be repeatedly and completely lysed by the appropriate phage in the course of several years. A set of 193 out-patients (189) and water sources (4) isolates failed to yield strains suitable for phage lysate preparation; 190 strains isolated abroad from patients with cystic fibrosis or respiratory infections included three isolates which, despite having a high degree of mucus production, were suitable for lysate preparation. The antigenic pattern of the phage lysates was ascertained by SDS-polyacrylamide gel electrophoresis.

Phagocyte-induced oxidative stress in patients with haemodialysis treatment and organ transplantation.

The aim of the study was to examine the phagocyte-derived production of reactive oxygen species (ROS), lipoperoxidation and the total radical-trapping antioxidant parameter (TRAP) in patients undergoing regular haemodialysis (HD) followed by kidney transplantation (n = 13). A significant increase in both spontaneous and activated ROS generation was found during the post-transplantation period in days 1-3. This effect was caused mainly by an increased number of neutrophils. On the other hand, the TRAP parameter was decreased in HD patients. After kidney transplantation, the TRAP parameter increased, reaching the level of healthy controls at the end of the first week after surgery. Increase in MDA level was determined after HD and kidney transplantation. It can be concluded from the results obtained that phagocyte mobilisation and increased oxidative stress after HD and kidney transplantation were associated with the insufficient activity of extracellular antioxidant mechanisms resulting in increased lipid peroxidation.

Total antioxidant capacity of serum increased in early but not late period after intestinal ischemia in rats.

The ischemia of small intestine was induced in anesthetized Wistar rats by occluding the superior mesenteric artery for 45 min and then the reperfusion was set. Serum samples were obtained at the end of the ischemic period and also during early (1 to 4 h) and late postischemic period (1 to 4 d). The total antioxidant capacity (TRAP) of serum samples was evaluated using luminol enhanced chemiluminescence. The increased mobilization of phagocytic cells and the release of reactive oxygen species into the circulation was observed from the first and second hour of the postischemic period, respectively. Nevertheless, the activity of natural antioxidant mechanisms of serum was already elicited at the end of the ischemic period. Furthermore, the TRAP of serum increased with the increasing duration of early postischemic period. Among the antioxidants studied, urate and ascorbate concentrations exerted the highest correlation with TRAP, but 31.6% of the total antioxidant capacity remained for the activity of an unidentified antioxidant(s). After being exhausted, the TRAP of serum oscillated around the preoperation level at days 1-4 of the postischemic period. The increase in total antioxidant capacity of serum induced by oxidative stress was sufficient to prevent lipoperoxidation both in serum and intestinal tissue.

Leukocyte mobilization, chemiluminescence response, and antioxidative capacity of the blood in intestinal ischemia and reperfusion.

Intestinal ischemia and reperfusion elicits changes in leukocyte counts and increased production of reactive oxygen species (ROS). The purpose of this study was to investigate whether these changes were followed by and/or connected with changes in the extracellular antioxidative capacity in a rat superior mesenteric artery (SMA) occlusion/reperfusion model. The SMA was occluded for 45 min and then allowed to be reperfused. Changes of leukocyte, polymorphonuclear (PMN), and lymphocyte counts, chemiluminescence (CL) of whole blood samples as a marker of ROS production, and the total antioxidative capacity of the serum were quantified at the end of ischemia and in 1 h intervals during the postischemic period up to 4 h. The myeloperoxidase (MPO) activity in the serum and intestinal tissue samples was also determined. The MPO activity in the intestinal tissue samples was significantly elevated at the end of ischemia, and this elevation lasted for the whole postischemic period. The oxidative challenge to the body induced a fast mobilization of extracellular antioxidative mechanisms already at the end of ischemia, which was followed by a significant increase in PMN counts and whole blood CL starting at the 2nd hour after reperfusion. The increased CL activity of whole blood was attributed to the increase of the circulating PMNs. No significant changes were observed in leukocyte and lymphocyte counts. It is concluded that compensatory mechanisms of the oxidative-antioxidative balance of the body react very quickly if challenged.

Determination of phagocyte activity in whole blood of carp (Cyprinus carpio) by luminol-enhanced chemiluminescence.

In this study, the phagocytic capacity of fish peripheral blood leucocytes was studied using the luminol-enhanced chemiluminescence (CL) method. Suspensions of rice starch (1%) or opsonized zymosan particles-OZP (0.2%) were used as activators. The level of CL was detected at 25 degrees C in various whole blood volumes (100, 50, 20 a 10 microliters) during the mixed or unmixed measurement mode. The peak of CL in all starch-activated samples was between 2.0-4.0 mV, regardless of blood volume or a mode of measurement. Similar results were obtained for OZP activated CL when measured in the mixed mode. On the other hand, the peak of OZP activated CL in unmixed samples was much higher and it showed positive correlation with the increasing volume of blood in a sample. In contrast, no significant differences between the reaction curve areas were found for different blood volumes. After correction for phagocyte number the highest CL activity per cell was observed in the samples containing 10 microliters of blood. It can be concluded that 10-20 microliters of blood are optimal volumes for the measurements of respiratory burst activity in the whole blood of carp and opsonized zymosan particles should be used as an activator. At the same time, the unmixed mode of measurement seems to give better results than the mixed one.