Intravenous infusion of PAF affects ovulation, fertilization and preimplantation embryonic development in NZB x NZW F1 hybrid mice

Platelet Activating Factor (PAF) is a bioactive phospholipid, which exhibits a variety of biological activities and plays a significant role in all aspects of reproduction. In this work, a single intravenous injection of various concentrations of PAF shortly after Human Chorionic Gonadotropin (HCG) administration as well as 24 and 48 h before HCG administration was studied in NZB x NZW F1 hybrid mice. Optimum results were observed when PAF was injected just after the administration of HCG. In this protocol, the concentrations of PAF exhibited bell-shaped response to every stage of development. Any concentration of PAF between 5.5 x 10(-11) and 5.5 x 10(-15)g/g b.w., caused an improved ovulation rate, an increased fertilization rate, an increased rate of cell cycle and an enhanced hatching blastocyst rate (P<0.05 for all stages). Injection of lyso-PAF had no effect in any stage. Our data show that the effect of PAF on early stages of embryo development in vitro is dependent on its way of administration, on the concentrations used as well as on the time PAF is injected.     

Low-dose oral prednisone improves clinical and ultrasonographic remission rates in early rheumatoid arthritis: results of a 12-month open-label randomised study

IntroductionIn early rheumatoid arthritis (RA), low-dose oral prednisone (PDN) co-medication yields better clinical results than monotherapy with disease-modifying anti-rheumatic drugs (DMARDs). In addition, ultrasonography (US) evaluation reveals rapid and significant effects of glucocorticosteroids on subclinical synovitis. No data currently exist that examine the clinical and US results offered by glucocorticoid co-medication over DMARD monotherapy in early RA patients.MethodsTwo hundred and twenty patients with early RA (< 1 year from clinical onset) were treated according to a low disease activity (LDA) targeted step-up protocol including methotrexate (MTX) and, in the active treatment arm, low-dose (6.25 mg/day) oral PDN over 12 months. Clinical disease activity measures were collected at baseline, 2, 4, 6, 9 and 12 months, and US examination of hands was performed at baseline, 6 and 12 months. Grey-scale and power Doppler (PD) synovitis were scored (0 to 3) for each joint. At 12 months, clinical remission according to the disease activity score among 28 joints was defined as the clinical outcome, and a total joint PD score of 0 (PD negativity) as the imaging outcome.ResultsEach group included 110 patients with comparable demographic, clinical, laboratory and US characteristics. At 12 months, the LDA rate was similar in the two groups, whilst the clinical remission rate (risk ratio = 1.61 (95% confidence interval = 1.08, 2.04)) and PD negativity rate (risk ratio = 1.31 (95% confidence interval = 1.04, 1.64)) were significantly higher in the MTX+PDN group.ConclusionIn early RA, despite a similar response rate in terms of LDA, low-dose oral PDN co-medication led to a higher proportion of clinical remission and PD negativity compared with MTX monotherapy, thus ensuring a better disease activity control.

Trial registration number

Current Controlled Trials ISRCTN2486111     

Staphylococci from the feces of different animal species: biotypes of Staphylococcus aureus strains of sheep and goat origin.

Staphylococcus aureus was found in 96% of the rectal swabs from 133 sheep and in 80% of the swabs from 125 goats. Seventy-seven percent of the isolates from both hosts exhibited the fibrinolytic and growth characteristics of human biotype A on human plasma and crystal violet agar, respectively, but 99% of these isolates resembled S. aureus of animal origin in their other properties. Only 21% of the sheep and 24% of the goat isolates were clearly identifiable as human biotype A and animal biotypes B and C.     

Patterns,origin and possible effects of sediment pollution in a Mediterranean lake

The influence of water permanence and high intra- and inter-annual hydrological variability on macrobenthos (organisms >1 mm) was studied using a taxonomical and a functional approach. The study was carried out in a Mediterranean salt marsh. Monthly samples of macrobenthic fauna were collected during two consecutive hydroperiods from six ponds with different water permanence (temporary, semi-permanent and permanent waters). Organisms were assigned to five functional response groups based on life-strategies according to their capacity to survive desiccation events, their dispersion capability and the necessity of water for their reproduction. Results from both approaches showed that the benthic community was more related to pond type than to intra- and inter-annual variability. The second aim was to analyse to which extent patterns in functional groups were determined by the existence of succession patterns or to environmental variability. In this sense, a clear succession pattern was not observed. In contrast, in most of the functional groups (4 out of 5), species within each functional group showed similar responses to water fluctuations. However, species of the fifth functional group, which comprised species without any particular adaptation to desiccation survival or avoidance, showed different responses to water level fluctuations. Guest editors: R. Céréghino, J. Biggs, B. Oertli & S. Declerck The ecology of European ponds: defining the characteristics of a neglected freshwater habitat     

Human serum facilitates hepatitis C virus infection, and neutralizing responses inversely correlate with viral replication kinetics at the acute phase of hepatitis C virus infection

The factors leading to spontaneous clearance of hepatitis C virus (HCV) or to viral persistence are elusive. Understanding virus-host interactions that enable acute HCV clearance is key to the development of more effective therapeutic and prophylactic strategies. Here, using a sensitive neutralization assay based on infectious HCV pseudoparticles (HCVpp), we have studied the kinetics of humoral responses in a cohort of acute-phase patients infected during a single nosocomial outbreak in a hemodialysis center. The 17 patients were monitored for the spontaneous outcome of HCV infection for 6 months before a treatment decision was made. Blood samples were taken frequently (15 +/- 4 per patient). Phylogenetic analysis of the predominant virus(es) revealed infection by only one of two genotype 1b strains. While all patients seroconverted, their sera induced two opposing effects in HCVpp infection assays: inhibition and facilitation. Furthermore, the ability of sera to facilitate or inhibit infection correlated with the presence of either infecting HCV strain and divided the patients into two groups. In group 1, the progressive emergence of a relatively strong neutralizing response correlated with a fluctuating decrease in high initial viremia, leading to control of viral replication. Patients in group 2 failed to reduce viremia within the acute phase, and no neutralizing responses were detected despite seroconversion. Strikingly, sera of group 2, as well as naive sera, facilitated infection by HCVpp displaying HCV glycoproteins from different genotypes and strains, including those retrieved from patients. These results provide new insights into the mechanisms of viral persistence and immune control of viremia.