The role of endosymbiotic Wolbachia bacteria in the pathogenesis of river blindness

Parasitic filarial nematodes infect more than 200 million individuals worldwide, causing debilitating inflammatory diseases such as river blindness and lymphatic filariasis. Using a murine model for river blindness in which soluble extracts of filarial nematodes were injected into the corneal stroma, we demonstrated that the predominant inflammatory response in the cornea was due to species of endosymbiotic Wolbachia bacteria. In addition, the inflammatory response induced by these bacteria was dependent on expression of functional Toll-like receptor 4 (TLR4) on host cells.     

Rückstände von Carbendazim und anderen Fungiziden im Bienenhonig aufgrund der Blütespritzung von Winterraps

Zusammenfassung: 91 hessische Rapshonige der Erntejahre 2000 bis 2002 wurden auf Rückstände der zur Blütespritzung zugelassenen Fungizide Carbendazim, Iprodion, Metconazol, Tebuconazol und Vinclozolin untersucht. Dabei traten Tebuconazol und Vinclozolin vereinzelt in Mengen bis max. 0,018 mg/kg auf, Carbendazim hingegen in 35,2 % aller Proben und in Gehalten von bis zu 0,118 mg/kg. Im Mai 2002 wurden zwei isoliert gelegene Rapsflächen (9,8 bzw. 5,5 ha) während der Vollblüte mit 1 l/ha Derosal^® (360 g/l Carbendazim) bzw. mit 1,5 l/ha Folicur^® (251,2 g/l Tebuconazol) gespritzt. In jeweils sechs Honigproben von unmittelbar an den Flächen aufgestellten Völkern wurden Rückstandsgehalte von durchschnittlich 0,145 mg/kg (0,061 – 0,227 mg/kg) Carbendazim bzw. 0,018 mg/kg (<BG – 0,025 mg/kg) Tebuconazol ermittelt. Wirkstoffspezifische Eigenschaften des Carbendazims führen offensichtlich zu außergewöhnlich hohen Belastungswerten im Honig. Ungeachtet ihrer toxikologischen Relevanz veranlassten diese Befunde die Herstellerfirmen zu einer zwischenzeitlichen Vertriebseinstellung von Carbendazim und Thiopanatemethyl auf dem deutschen Markt.

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Residues of Carbendazim and other fungicides in honey due to blossom application in canola

Summary: During 2000 to 2002, 91 Hessian spring honeys from regions with an extended cultivation of canola were analysed for residues of the registered fungicides Carbendazim, Iprodion, Metconazol, Tebuconazol and Vinclozolin. The samples included 15 honeys from certified ecological apiaries.While Iprodion and Metconazol were not detected at all and Tebuconazol and Vinclozolin only sporadic with maximum levels of 0,018 mg/kg, Carbendazim was found in 35,2 % of the samples with up to 0,118 mg/kg. The eco honeys did not differ from the other samples.In May 2002 two isolated canola fields (9,8 resp. 5,5 ha) were treated with 1 l/ha Derosal^® (active in gredient: 360 g/l Carbendazim) in 600 l water/ha resp. with 1,5 l/ha Folicur^® (active ingredient: 251,2 g/l Tebuconazol) in 400 l water/ha during full blossom while a third field served as an untreated control. Three honey bee colonies were placed close to each field four days before treatment. From each hive, two samples of fresh honey were taken seven days after the treatment and analysed for residues of Carbendazim and Tebuconazol. While only one of six samples from the control field was contaminated with 0,080 mg/kg Carbendazim, each of the six honey samples from the Carbendazim treated field showed residues of Carbendazim (average: 0,145 mg/kg, range: 0,061 – 0,227 mg/kg) and five of six samples from the Tebuconazol treated field were positive for Tebuconazol (average: 0,018 mg/kg, range: <DL – 0,025 mg/kg).Due to its specific characters (slightly hydrophilic compared to other fungicides) a blossom application of Carbendazim can result in extremely high residue levels in honey. In the meantime, the manufacturers of Carbendazim and Thiophanatemethyl acknowledged these findings and, irrespectively of its toxicological relevance, stopped their deal with such products on the German market.

     

Toll‐like receptor and related cytokine mRNA expression in bovine corpora lutea during the oestrous cycle and pregnancy

Improving our understanding of the mechanisms controlling the corpus luteum (CL) and its role in regulating the reproductive cycle should lead to improvements in the sustainability of today's global animal industry. The corpus luteum (CL) is a transient endocrine organ composed of a heterogeneous mixture steroidogenic, endothelial and immune cells, and it is becoming clear that immune mechanisms play a key role in CL regulation especially in luteolysis. Toll‐like receptors (TLR) mediate innate immune mechanisms via the production of pro‐inflammatory cytokines, especially within various tissues, although the role of TLR within CL remains unknown. Thus, the objectives of this study were to characterize TLR mRNA expression in the CL during the oestrous cycle and in pregnancy (day 30–50), and to examine the role of TLR signalling in luteal cells. Corpora lutea were collected at various stages of the cycle and pregnancy and analysed for TLR and cytokine mRNA expression. In addition, luteal cells were cultured with the TLR4 ligand (lipopolysaccharide, LPS) for 24 h to evaluate the role of TLR4 in regulating luteal function. Toll‐like receptors 1, 2, 4, 6, tumour necrosis factor alpha (TNF), interferon gamma (IFN‐G), and interleukin (IL)‐12, mRNA expressions were greatest in regressing CL compared with earlier stages (p < .05), whereas no change was observed for IL‐6 mRNA expression. Cytokine mRNA expression in cultured luteal cells was not altered by LPS. Based on these data, one or more of the TLRs found within the CL may play a role in luteolysis, perhaps via pro‐inflammatory cytokine mRNA expression.     

Hormone Profiles of Mares Affected by the Mare Reproductive Loss Syndrome

While searching for the cause of the Mare Reproductive Loss syndrome (MRLS), we postulated that 1 of 3 tissues in 40–120 D pregnant mares was the likely primary target of the noxious factor that caused early abortions: The corpora lutea (CL), the endometrium or the fetus and/or its membranes. At this stage of gestation, progesterone (P4) is solely produced by luteal tissue, eCG by endometrial cups in the endometrium and oestrogens by the feto‐placental unit. We determined whether concentrations of P4, eCG and/or total conjugated oestrogens (CE) would indicate which tissue was targeted during the MRLS. P4, eCG and CE were measured in single serum samples collected from 216 mares, 60–110 D after ovulation during the 2001 MRLS outbreak. All mares had previously been confirmed pregnant by ultrasonography. The following data was obtained from each mare: Interval from ovulation, pregnancy status and normalcy of fetal fluids at the time of sampling, and pregnancy status 3 weeks after sampling and at term. There were no meaningful differences in hormone concentrations between pregnant mares that had normal and excessively echogenic fetal fluids at the time of sampling. CE were lower (p < 0.05) in mares that aborted after sample collection than in mares the carried to term. In 8 mares from which multiple samples were obtained, CE consistently decreased prior to any decreases in P4 or eCG. Arguments are presented that lead to the hypothesis that the fetal trophoblast was the primary target of the MRLS agent.     

U/Pb zircon geochronology and tempo of the end-permian mass extinction

The mass extinction at the end of the Permian was the most profound in the history of life. Fundamental to understanding its cause is determining the tempo and duration of the extinction. Uranium/lead zircon data from Late Permian and Early Triassic rocks from south China place the Permian-Triassic boundary at 251.4 +/- 0.3 million years ago. Biostratigraphic controls from strata intercalated with ash beds below the boundary indicate that the Changhsingian pulse of the end-Permian extinction, corresponding to the disappearance of about 85 percent of marine species, lasted less than 1 million years. At Meishan, a negative excursion in delta13C at the boundary had a duration of 165,000 years or less, suggesting a catastrophic addition of light carbon.     

Workplace bullying and relationships with health and performance among a sample of New Zealand veterinarians

AIM: To examine the relationships between workplace bullying, destructive leadership and team conflict, and physical health, strain, self-reported performance and intentions to quit among veterinarians in New Zealand, and how these relationships could be moderated by psychological capital and perceived organisational support.

METHODS: Data were collected by means of an online survey, distributed to members of the New Zealand Veterinary Association. Participation was voluntary and all responses were anonymous and confidential. Scores for the variables measured were based on responses to questions or statements with responses categorised on a linear scale. A series of regression analyses were used to assess mediation or moderation by intermediate variables on the relationships between predictor variables and dependent variables.

RESULTS: Completed surveys were provided by 197 veterinarians, of which 32 (16.2%) had been bullied at work, i.e. they had experienced two or more negative acts at least weekly over the previous 6 months, and nine (4.6%) had experienced cyber-bullying. Mean scores for workplace bullying were higher for female than male respondents, and for non-managers than managers (p<0.01). Scores for workplace bullying were positively associated with scores for destructive leadership and team conflict, physical health, strain, and intentions to quit (p<0.001). Workplace bullying and team conflict mediated the relationship between destructive leadership and strain, physical health and intentions to quit. Perceived organisational support moderated the effects of workplace bullying on strain and self-reported job performance (p<0.05).

CONCLUSIONS: Relatively high rates of negative behaviour were reported by veterinarians in this study, with 16% of participants meeting an established criterion for having been bullied. The negative effects of destructive leadership on strain, physical health and intentions to quit were mediated by team conflict and workplace bullying. It should be noted that the findings of this study were based on a survey of self-selected participants and the findings may not represent the wider population of New Zealand veterinarians.