Steroid-induced polycystic ovaries in rats: effect of electro-acupuncture on concentrations of endothelin-1 and nerve growth factor (NGF), and expression of NGF mRNA in the ovaries,the adrenal glands,and the central nervous system

Previous studies on the effect of repeated electro-acupuncture (EA) treatments in rats with steriod-induced polycystic ovaries (PCO), EA has been shown to modulate nerve growth factor (NGF) concentration in the ovaries as well as corticotropin releasing factor (CRF) in the median eminence (ME). In the present study we tested the hypothesis that repeated EA treatments modulates sympathetic nerve activity in rats with PCO. This was done by analysing endothelin-1 (ET-1), a potent vasoconstrictor involved in ovarian functions, as well as NGF and NGF mRNA expression involved in the pathophysiological process underlying steroid-induced PCO.The main result in the present study was that concentrations of ET-1 in the ovaries were significantly lower in the PCO group receiving EA compared with the healthy control group (p < 0.05). In the hypothalamus, however, ET-1 concentrations were found to be significantly higher in the PCO group receiving EA than in the healthy control group (p < 0.05). Concentrations of ovarian NGF protein were significantly higher in the PCO control group compared with the healthy control group (p < 0.001), and these concentrations decreased significantly after repeated EA treatments compared with those in the PCO control group (p < 0.05) and were found to be the same as those in the healthy control group. In conclusion, these results indicate that EA modulates the neuroendocrinological state of the ovaries, most likely by modulating the sympathetic nerve activity in the ovaries, which may be a factor in the maintenance of steroid-induced PCO.     

Proteomic study of non-typable Haemophilus influenzae

Non-typable Haemophilus influenzae (NTHi) are small, gram-negative bacteria and are strictly human pathogens, causing acute otitis media, sinusitis and community-acquired pneumonia. There is no vaccine available for NTHi, as there is for H. influenzae type b. Recent advances in proteomic techniques are finding novel applications in the field of vaccinology. There are several protein separation techniques available today, each with inherent advantages and disadvantages. We employed a combined proteomics approach, including sequential extraction and analytical two-dimensional polyacrylamide electrophoresis (2D PAGE), and two-dimensional semi-preparative electrophoresis (2D PE), in order to study protein expression in the A4 NTHi strain. Although putative vaccine candidates were identified with both techniques, 11 of 15 proteins identified using the 2D PE approach were not identified by 2D PAGE, demonstrating the complementarily of the two methods.     

Impact of PCB on resistance to Flavobacterium psychrophilum after experimental infection of rainbow trout Oncorhynchus mykiss eggs by nanoinjection

The effects of sublethal exposure of a commercial blend of polychlorinated biphenyls (PCB), i.e. Clophen A50, on disease resistance to the aetiological agent of rainbow trout fry syndrome, Flavobacterium psychrophilum, were investigated. Newly fertilised rainbow trout Oncorhynchus mykiss eggs were nanoinjected with 2 doses of Clophen A50 (0.4 or 2 microg egg(-1)) and/or 100 colony forming units of F. psychrophilum. The mean cumulative mortality in control groups, and groups exposed to the lower dose of Clophen A50 (0.4 microg egg(-1)) was below 5.0%. The mean cumulative mortality in groups exposed to the higher dose of Clophen A50 (2.0 microg egg(-1)) was 5.8%, which was not significantly different from the control groups. In all groups infected with F. psychrophilum, with or without exposure to Clophen A50, significantly higher cumulative mortalities compared with control groups were recorded. No differences in mortality were recorded between groups exposed to bacteria alone or bacteria in combination with the higher dose of Clophen A50 (21.6 and 20.4%, respectively). Decreased disease resistance was recorded in groups exposed to F. psychrophilum and the lower dose of Clophen A50, with a mean cumulative mortality of 56.0%. These results could be due to non dose-dependent effects on the immune system, or toxic effects of PCB or their metabolites on the bacteria in groups exposed to the higher dose of Clophen A50. The present study indicates that maternal transfer of PCB might affect disease resistance to vertically transmitted F. psychrophilum.     

Metabolically improved exopolysaccharide production by Streptococcus thermophilus and its influence on the rheological properties of fermented milk

Altered levels of enzymes in the central carbon metabolism in Streptococcus thermophilus increased the exopolysaccharide (EPS) production 3.3 times over that of the parent strain. The influence of enhanced EPS production on the rheological properties of fermented milk is described for engineered strains of S. thermophilus which produce different levels of EPSs.     

Bacterial cell wall-expressed protein A triggers supraclonal B-cell responses upon in vivo infection with Staphylococcus aureus

We have previously shown that staphylococcal protein A (SpA) anchored to the cell wall of Staphylococcus aureus acts as a virulence factor in septic arthritis. Apart from the ability of SpA to interact with Fcgamma, it also binds to Fab-regions with immunoglobulin heavy chains encoded by the V(H) clan III gene family. The objective of the present study was to investigate whether in vivo expression of SpA by staphylococci induces V(H)III-dependent supraclonal B-cell responses, and whether such responses may affect the ability of the host to produce anti-staphylococcal antibodies. Upon primary infection of mice, a SpA-expressing staphylococcal strain gave rise to significantly higher serum levels of V(H)III-encoded antibodies specific for SpA devoid of Fcgamma-binding ability (MSpA) than an isogeneic spa deletion mutant strain. The V(H)III-dependence of MSpA-specific antibody responses was affected by the size of the staphylococcal inoculum, and differed for IgM and IgG isotypes. Mice that had recovered from a prior mild infection from a SpA-expressing strain were protected against infection-induced weight loss upon reinfection. Although no lasting MSpA-specific IgG was induced by previous mild infection, these protected mice possessed IgG specific for clumping factor A, a conventional staphylococcal protein antigen. Our findings demonstrate that the expression of a B-cell superantigen during staphylococcal infection causes supraclonal changes to the immune system. Notably, while superantigen-triggered B-cell responses do not favor the development of SpA-specific memory B-cells, such responses do not interfere with the development of antibodies specific for a staphylococcal protein antigen associated with protective immunity.     

Expression of staphylococcal clumping factor A impedes macrophage phagocytosis

Clumping factor A (ClfA), a fibrinogen-binding protein linked to the Staphylococcus aureus cell wall, is an important virulence factor in infection models, e.g., of septic arthritis. However, the mechanism(s) by which ClfA contributes to the virulence of the bacterium is unknown. In the present study, the impact of ClfA expression on the phagocytosis of S. aureus by macrophages was investigated using clfA-positive and clfA-negative isogenic strains. Furthermore, the possible contribution of ClfA to the proinflammatory and immunostimulatory activity of S. aureus was studied. Our results indicate that ClfA expression significantly protects S. aureus against macrophage phagocytosis. This protection does not require the presence of intact fibrinogen, a ligand for ClfA. ClfA expression by S. aureus enhanced the proliferative response of spleen cells. On the other hand, a clfA mutant strain caused more release of proinflammatory mediators by macrophages than its clfA-positive parental strain. Both the protection against phagocytosis and the enhanced immunostimulatory activity provided by ClfA expression are likely to contribute to the in vivo virulence of S. aureus.     

Decreased levels of soluble amyloid β-protein precursor and β-amyloid protein in cerebrospinal fluid of patients with systemic lupus erythematosus

Symptoms originating from the central nervous system (CNS) frequently occur in patients with systemic lupus erythematosus (SLE). These symptoms are extremely diverse, including a state of dementia. The aim of this study was to examine the cerebrospinal fluid (CSF) content of soluble molecules indicating axonal degeneration and amyloidogenesis. One hundred and fourteen patients with SLE and age-matched controls were evaluated clinically, with magnetic resonance imaging of the brain and CSF analyses. Levels of tau, amyloid precursor protein (APP), beta-amyloid protein (Abeta42), and transforming growth factor beta (TGF-beta) were all determined using sandwich ELISAs.APP and Abeta42 levels were significantly decreased in SLE patients irrespective of their CNS involvement, as compared with healthy controls. Patients with neuropsychiatric SLE who underwent a second lumbar puncture following successful cyclophosphamide treatment showed further decreases of Abeta42. CSF-tau levels were significantly increased in SLE patients showing magnetic resonance imaging-verified brain pathology as compared with SLE patients without such engagement. Importantly, tau levels displayed significant correlation to Abeta42 levels in the CSF. Finally, TGF-beta levels were significantly increased in patients with neuropsychiatric SLE as compared with those without. Low intrathecal levels of Abeta42 found in SLE patients seem to be a direct consequence of a diminished production of APP, probably mediated by heavy anti-inflammatory/immuno-suppressive therapy. Furthermore, our findings suggest that CSF tau can be used as a biochemical marker for neuronal degeneration in SLE. Finally, the increased TGF-beta levels observed may support a notion of an ongoing anti-inflammatory response counteracting tissue injury caused by CNS lupus.     

The effect of polyamine biosynthesis inhibition on growth and differentiation of the phytopathogenic fungus Sclerotinia sclerotiorum

We studied the effects of several polyamine biosynthesis inhibitors on growth, differentiation, free polyamine levels and in vivo and in vitro activity of polyamine biosynthesis enzymes in Sclerotinia sclerotiorum. -Difluoromethylornithine (DFMO) and -difluoromethylarginine (DFMA) were potent inhibitors of mycelial growth. The effect of DFMO was due to inhibition of ornithine decarboxylase (ODC). No evidence for the existence of an arginine decarboxylase (ADC) pathway was found. The effect of DFMA was partly due to inhibition of ODC, presumably after its conversion into DFMO by mycelial arginase, as suggested by the high activity of this enzyme detected both in intact mycelium and mycelial extracts. In addition, toxic effects of DFMA on cellular processes other than polyamine metabolism might have occurred. Cyclohexylamine (CHA) slightly inhibited mycelial growth and caused an important decrease of free spermidine associated with a drastic increase of free putrescine concentration. Methylglyoxal bis-[guanyl hydrazone] (MGBG) had no effect on mycelial growth. Excepting MGBG, all the inhibitors strongly decreased sclerotial formation. Results demonstrate that sclerotial development is much more sensitive to polyamine biosynthesis inhibition than mycelial growth. Our results suggest that mycelial growth can be supported either by spermidine or putrescine, while spermidine (or the putrescine/spermidine ratio) is important for sclerotial formation to occur. Ascospore germination was completely insensitive to the inhibitors.