Detection of the endotoxin of Gram-negative bacteria in human blood

Recent new data on the important role played by lipopolysaccharides (endotoxin) of Gram negative bacteria in physiology and pathogenesis of the most important human infectious and noninfectious diseases testify to the necessity of wide clinical trials of different methods for LPS detection in blood and other physiological fluids. Among presently available diagnostic methods for endotoxinemia detection, the highly sensitive LAL (Limulus Amebocyte Lysate) test in various modifications is most widely used. The LAL test is known to be non-specific, however many drawbacks of this test have been successfully overcome. The results of clinical studies on the determination of the LPS activity in the systemic blood stream and antibody titers to its most common determinants, as well as the reserves of endotoxin binding with granulocytes give grounds for optimistic evaluation of the future studies on the role of LPS in human physiology and pathology. In clinical practice both positive sides and drawbacks of the presently known methods for LPS detection, including the LAL test, must be borne in mind for the complex evaluation of endotoxinemia levels.     

Characterization of antilysozyme and anticomplement signs in brucellae during experimental infection

The dependence of the course of experimental infection on the initial level of antilysozyme activity of Brucella clones was studied using 40 noninbred guinea pigs. As revealed in this study, the antilysozyme sign of brucellae influenced the pathogenesis of brucellosis, facilitating the prolonged survival of brucellae in the host body. The results thus obtained may be used for the prognostication of the course of Brucella infection.     

The clinical laboratory assessment of vancomycin (Edicin) efficacy in treating suppurative wounds of the skin and soft tissues, burn wounds and the infectious complications of burns]

Clinical and bacteriological efficacies of vancomycin (Edicin, LEK) in the treatment of 17 patients with wound infection and 13 patients with thermal affections were studied. The clinical efficacy in the group of the patients with purulent wounds of the soft tissues amounted to 94.1 per cent and that in the patients with thermal affections was 92.3 per cent. The bacteriological effect was recorded in 86.6 per cent of the patients with purulent wounds of the soft tissues and in 69.3 per cent of the patients with burn infections. The drug intolerability was observed in two cases.     

Spatiotemporal Patterns of Laccase Activity in Interacting Mycelia of Wood-Decaying Basidiomycete Fungi

Abstract Interspecific fungal interactions are important ecological processes, whereas their physiological mechanisms are little understood. The aim of this work was to study how activity of fungal extracellular laccase was changed across mycelia during interactions between white- and brown-rot basidiomycetes from different wood decay stages. Qualitative assay of eight species interacting with each other in all combinations showed four spatial patterns of laccase activity: (I) laccase activity present both in contact zone and mycelium, (II) laccase activity only in contact zone, (III) laccase activity in mycelium but not in contact zone, (IV) no laccase activity. Presence of laccase activity only in the contact zone was more frequent than expected from random samples associated with mycelia that replaced other ones. On the other hand, the presence of laccase activity in the mycelium but not in the contact zone was only attributed to fungal species that were replaced by their antagonists. After one month, laccase activity was distributed over mycelia more homogeneously than after 6 days of interactions. In interacting mycelia, laccase activity was higher than in control and increasing with time. Saprotrophic fungi from late successional stages of wood decay generally had higher laccase activity than early succession saprotrophic and pathogenic fungi. The qualitative assays were confirmed by quantitative assay of total laccase activity. Significance of the results in antagonistic fungal interactions as well as in the processes of hyphal tip growth and mycelium senescence is discussed. Received: 6 October 1999; Accepted: 1 February 2000; Online Publication: 5 May 2000     

Multicentre study of comparative efficacy of meropenem and combined regimens for empirical antibacterial therapy of severe nosocomial infections: results of clinical and pharmacoeconomic analysis]

Adequacy and effectiveness of empirical antibacterial therapy of severe nosocomial infections with meropenem vs. combined regimens of antibacterial therapy were investigated and the ratio of the cost and effectiveness of the compared regimens was evaluated. A prospective, randomized, open, comparative study of two initiative regimens of empirical antibacterial therapy of severe nosocomial infections was performed: meropenem in a daily dose of 1.5-3 g and the standard regimen with the use of betalactams and fluoroquinolones in combination with aminoglycosides and/or metronidazole. Patients with recorded diagnosis of nosocomial pneumonia (including the ventilator-associated one) or abdominal infection with the signs of severe sepsis and severity of APACHE II > 14 were enrolled. The patients were stratified into 2 groups subject to the disease severity, i.e. APACHE II 15-20 and APACHE II 21-25. One hundred thirty five out of 166 patients with recorded nosocomial infection were included into the final estimate of the therapy adequacy and effectiveness (Protocol Analysis): 62 patients were treated with meropenem and in the treatment of 73 patients the standard antibacterial therapy was used. In the group of the patients treated with meropenem there were stated significantly higher clinical effectiveness (recovery in 80.6% of the patients vs. the control of 46.6%, p < 0.01) and pathogen eradication (89.6 and 48.1% respectively, p < 0.01). The difference in the clinical and bacteriological effectiveness of meropenem and the standard therapy was more evident in the subgroups of more severe patients (APACHE > 20). With the use of meropenem the probability of recovery from nosocomial infection was significantly higher (RR 1.73-1.94, p < 0.001) vs. the control. Meropenem provided significantly higher eradication of the pathogens: P. aeruginosa (88 and 40% respectively, p = 0.007), E. coli (100 and 46.7%, p = 0.003), Acinetobacter spp. (90.9 and 40%, p = 0.02). The antibacterial therapy with the use of meropenem was assessed as adequate in 51 out of 56 patients (91.1%), that was 3 times as frequent as with the use of the standard antibacterial therapy (33.9%). The cost-effectiveness coefficient with the use of meropenem was 2.2 times lower vs. the control. Therefore, the empirical therapy of severe nosocomial infections with meropenem proved to be more adequate and from the economic viewpoint more advantageous vs. the standard combined regimens of antibacterial therapy, that was evident from significantly higher clinical and bacteriological efficacy of the treatment and decrease of the terms of the patients hospitalization in intensive care units (on the average by 5 days).     

Effects of intracerebroventricular administration of a caspase-3 inhibitor Z-DEVD-FMK on behavior of rats

Rats received intracerebroventricular injections of z-DEVD-FMK (caspase-3 inhibitor) or z-FA-FMK (control peptide) in a dose of 3 nmol. Administration of z-DEVD-FMK significantly decreased the number of avoidance reactions in some blocks of trials in active avoidance (shuttle box) learning. However, only slight effect of the caspase inhibitor across the session was found. Z-DEVD-FMK impaired development of some essential components of the two-way active avoidance performance, such as escape reaction, conditioned fear reaction, and inter-trial crossings. Z-DEVD-FMK did not impair working memory in the spontaneous alternation behavior paradigm. Z-DEVD-FMK affected neither emotionality nor locomotor activity in the open-field test. It also did not influence behavior in the light-dark chamber. Measurement of caspase-3 activity in rat brain regions involved in active avoidance learning revealed z-DEVD-FMK-related inhibition of the enzyme activity most pronounced (about 30%) in the fronto-parietal cortex; a similar effect was close to significant in the hippocampus. The results suggest the involvement of brain caspase-3 in selected forms of learning.