Effects of microbial metabolites on catalase activity and growth of Staphylococcus aureus 6538 P

The effects of cell extracts and supernatants ofLactobacillus spp. andCorynebacterium spp. on catalase activity and growth ofStaphylococcus aureus 6538 P were studied. Intra- and extracellular metabolites of lactobacilli and corynebacteria inhibited catalase activity ofS. aureus 6538 P. The growth ofS. aureus 6538 P decreased after incubation with lactobacillus metabolites. The inhibitory effect of intra- and extracellular metabolites of lactobacilli and corynebacteria on catalase activity ofS. aureus is a possible pathway of microbial interrelations responsible for the formation and/or development of microbial biocenoses. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 7, pp. 80–82, July, 2000     

How effective is patient-controlled analgesia? A randomized comparison of two protocols for pain relief during oocyte recovery

Although the conventional method of pain relief during outpatient oocyte recovery involves physician-administered drugs, patient- controlled analgesia (PCA) offers an alternative technique with the potential to give women more control over peroperative analgesia. We conducted a prospective randomized study to compare the effect of fentanyl administered either through a PCA delivery system or by a physician. Thirty-nine women were randomized to PCA during egg collection while 42 were allocated to receive intermittent doses administered by a physician. Pain was evaluated by means of a 100 mm linear analogue scale. The mean (SD) pain score in the PCA group was 38.5 (19.8) while in the other group it was 46.1 (21.3) (P = 0.1). In the PCA group, 64% of women felt very satisfied with their analgesia as compared with 57% in the non-PCA group (P = 0.6). Among the PCA users, 39% of demands were successful. Significantly more fentanyl (97.5 microg) was used in the PCA group than in the other group (84.6 microg) (P = 0.03). Though intraoperative PCA with fentanyl is an effective alternative to physician-administered techniques, many women still feel the need for more analgesia during the procedure.      

Primary culture of prostatic adenocarcinoma: a model for studies of stromal-epithelial interactions

Primary culture of prostatic adenocarcinoma is obtained from surgical material after radical prostatectomy. Typing of the obtained culture with antibodies to vimentin and cytokeratins has shown that the proportion of basic cell components--stromal and epithelial--in vitro correlates with such in the initial tumor tissue. In cultivation in different media active migration and proliferation of all cell types in the presence of embryonal serum and suppression of the stromal component in the medium where the serum was replaced for bovine hypophysis extract were observed. A comparative immunohistochemical analysis registered a release into culture of alpha SMA-positive myofibroblasts and active expression of TGF beta-1 in the medium containing serum. Design of dynamic mixed cell systems may serve a convenient model for investigation of stromal-epithelial interactions and their changes in cancer progression.     

Microglia are more susceptible than macrophages to apoptosis in the central nervous system in experimental autoimmune encephalomyelitis through a mechanism not involving Fas (CD95)

Morphological studies have shown that macrophages and microglia undergo apoptosis in the central nervous system (CNS) in acute experimental autoimmune encephalomyelitis (EAE) in the Lewis rat. To assess the relative levels of macrophage and microglial apoptosis, and the molecular mechanisms involved in this process, we used three-colour flow cytometry to identify CD45lowCD11b/c+ microglial cells and CD45highCD11b/c+ macrophages in the inflammatory cells isolated from the spinal cords of Lewis rats 13 days after immunization with myelin basic protein (MBP) and complete Freund's adjuvant. Simultaneously, we analyzed the DNA content of these cell populations to assess the proportions of cells undergoing apoptosis and in different stages of the cell cycle or examined their expression of three apoptosis- regulating proteins, i.e. Fas (CD95), Fas ligand (FasL) and Bcl-2. Microglia were highly vulnerable to apoptosis and were over-represented in the apoptotic population. Macrophages were less susceptible to apoptosis than microglia and underwent mitosis more frequently than microglia. The different susceptibilities of microglia and macrophages to apoptosis did not appear to be due to variations in Fas, FasL or Bcl- 2 expression, as the proportions of microglia and macrophages expressing these proteins were similar, and were relatively high. Furthermore, in contrast to T cell apoptosis, apoptosis of microglia/macrophages did not occur more frequently in cells expressing Fas or FasL, or less frequently in cells expressing Bcl-2. These results indicate that the apoptosis of microglia and CNS macrophages in EAE is not mediated through the Fas pathway, and that Bcl-2 expression does not protect them from apoptosis. Expression of FasL by macrophages and microglia may contribute to the pathogenesis and immunoregulation of EAE through interactions with Fas+ oligodendrocytes and Fas+ T cells. The high level of microglial apoptosis in EAE indicates that microglial apoptosis may be an important homeostatic mechanism for controlling the number of microglia in the CNS following microglial activation and proliferation.      

Electrolyte composition of rat skeletal muscles after hypokinesia

It has been suggested that the electrolyte composition of rat skeletal muscles may change after the exposure to hypokinesia (diminished muscular activity). Thus, the aim of this study was to determine the concentration levels of ions of Na, K, Ca and Mg in muscle tissue and the endogenous media of 135 rats weighing 140-160 g during the readaptation period (RP) of 30 days and after a 96 days exposure to hypokinesia (HK). The animals were divided into two groups. The 1st group (70 rats) was subjected to "pure" HK, that is, without the use of any preventive measures, and the 2nd group (65 rats) was placed under usual conditions and served as control. For the simulation of the hypokinetic effect, the 1st group of rats were kept in small individual cages made of plexiglass. The concentration levels of ions of Na, K, Ca and Mg were determined in muscle tissue and the endogenous media of rats by the method of atom-absorption spectrophotometry. Blood plasma ion composition changed significantly. Tissular fluid content and the tissular concentrations of Na, K, Ca and Mg in muscles also changed significantly during the readaptation period. It was concluded that the concentration levels of ions of Na, K, Ca and Mg in connective tissues, as well as endogenous medium of rats evidently changed significantly during the readaptation period and after the exposure to hypokinesia.