Pyridyl terpenoid ethers with high juvenile hormone activity

Pyridyl terpenoid ethers have outstanding juvenile hormone activity in Tenebrio molitor compared with their phenyl analogues (6,7-epoxy-3,7-dimethyloct-2-enyl 6-ethyl-3-pyridyl ether and 7-ethoxy-3,7-dimethyloct-2-enyl 6-ethyl-3-pyridyl ether are active at 100 pg/larva). The compounds were also active in Galteria mellonella and Culex pipiens.     

A case-control study of risk factors in light Taenia saginata cysticercosis in Danish cattle.

Risk factors in light T. saginata cysticercosis in cattle herds were investigated in a case-control study. The case group consisted of farms from which cattle with low-grade cysticercosis had been detected at slaughter. The control group consisted of farms where no cases were detected during the same period. The major risk factor identified was allowing cattle access to drink from streams carrying effluent from sewage treatment plants (odds ratio = 3.6). Spreading of septic tank sludge through deliberate or accidental mixing with animal slurry, deposition of sewage sludge, and proximity to railways, camping sites or sewage treatment plants seemed to be of minor importance.     

Nursing sickness in lactating mink (Mustela vison). I. Epidemiological and pathological observations.

In a retrospective survey, the epidemiological characteristics of nursing sickness in Standard Black and Pastel mink (Mustela vison) were examined in a Danish fur research farm. Based on the clinical diagnosis of the disease, the overall morbidity in a total of 1774 lactating females amounted to 14.4% and the case fatality rate to 7.8%. Apparently healthy females weaned an average of 5.0 kits per litter, while dams suffering from nursing sickness raised and weaned an average of 5.4 kits per litter (p less than 0.01). Based on logistic regression analysis, the increasing age of the lactating dam, followed by littersize and female weight loss, appeared to be major determinants for the development of nursing sickness. The impact of additional covariates such as litter weight gain and female color type were remarkably low. At weaning (day 43) the mean individual live weight of the kits of either sex did not differ between healthy and sick dams. In Standard Black, the total biomass of the offspring raised by sick dams was significantly larger than that of the healthy controls (p less than 0.01). During the final two weeks of lactation, apparently healthy dams lost on average 14% of their body mass, whereas those affected by nursing sickness had a mean weight loss of about 31% (p less than 0.001). Postmortem examination of 25 dams with severe nursing sickness verified the clinical findings of progressive dehydration and emaciation. The gastrointestinal tract was empty and gastric ulcers and melaena were frequently present. Other common findings included small livers,enlarged adrenals and pitted kidneys.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prevalence and incidence of bovine trypanosomosis on the Adamaoua plateau in Cameroon 10 years after the tsetse eradication campaign

Between March 2004 and February 2005, the monthly incidence of trypanosome infections was measured in cattle from nine sentinel herds in the Adamaoua province of Cameroon. Three herds of 20 cattle each were kept on the plateau which has been cleared from tsetse flies about 10 years ago, three other herds were grazing in the tsetse infested valley whereas the last three were herded in the buffer zone. The cross-sectional study showed that the initial trypanosomosis prevalence was 1.8, 5.2 and 2.0% on the plateau, in the buffer zone and the valley, respectively. During the longitudinal study, the trypanosomosis incidence was high in the valley (3.7-20%) and the buffer zone (1.8-13.4%), whereas it was significantly lower (0-2.1%) on the plateau. Tsetse flies, mainly Glossina morsitans submorsitans and a few G. tachinoides, were caught in the valley and the buffer zone, but none on the plateau. The data indicate a low trypanosomosis risk on the plateau. Further entomological studies, however, are required to clarify the origin of the trypanosome infections on the plateau.     

Heat-stable phytases in transgenic wheat (Triticum aestivum L.): deposition pattern, thermostability, and phytate hydrolysis

The present paper addresses the question of thermotolerance of in planta synthesized heterologous enzymes using phytase as a model. Two individual transgenic wheat materials expressing an Aspergillus fumigatus phytase with a low denaturation temperature (62.5 degrees C) but a high refolding capacity, and a rationally designed consensus phytase engineered to a high denaturation temperature (89.3 degrees C), were evaluated. High levels of endosperm specific expression were ensured by the wheat high molecular weight glutenin 1DX5 promoter. Immunodetection at the light and electron microscopical level shows unequivocally that the heterologous phytase is deposited in the vacuole, albeit that the transformation constructs were designed for secretion to the apoplast. Evaluation of heat stability properties and kinetic properties unraveled that, under these deposition conditions, heat stability based on high unfolding temperature is superior to high refolding capacity and represents a realistic strategy for improving phosphate and mineral bioavailability in cereal-based feed and food.     

Bovine neonate natural killer cells are fully functional and highly responsive to interleukin-15 and to NKp46 receptor stimulation

Natural killer (NK) cells are key components of the innate immune system with their killing and cytokine producing abilities. Bovine NK cells have been characterized as NKp46⁺/CD3⁻ lymphocytes, but little is known about these cells in neonatal calves. As the newborn calf, with an insufficiently developed acquired immunity, has to employ the innate immune system, we wanted to investigate whether neonate NK cells had the same characteristics as cells from older calves. Freshly isolated neonate and calf NK cells presented the same resting CD2⁺/CD25^low/CD8^−/low phenotype. Neonates less than 8 days old had one third of the circulating NKp46⁺ cells of older calves, but the NK cells proliferated more actively in vitro in the presence of interleukin (IL)-2 or IL-15. Moreover, neonate NK cells were more cytotoxic both in an NKp46 mediated redirected lysis assay and in direct killing of a bovine cell line MDBK when cultured in the presence of IL-15. Neonate and calf NK cells cultured in the presence of IL-2 and then stimulated with IL-12 produced similar dose-dependent interferon (IFN)-γ amounts, while IL-15 cultured NK cells did not give such a response whatever the age. However, neonatal NK cells cultured in IL-15 and stimulated by IL-12 concomitantly with cross-linking of NKp46, produced 4 to 5 times more IFN-γ than calf NK cells. These data suggest that although present in lower number at birth, neonate NK cells are fully functional and are more responsive to IL-15 and activation through the NKp46 receptor than NK cells from older calves.     

Bovine natural killer cells

Natural killer (NK) cells have received much attention due to their cytotoxic abilities, often with a focus on their implications for cancer and transplantation. But despite their name, NK cells are also potent producers of cytokines like interferon-gamma. Recent discoveries of their interplay with dendritic cells and T-cells have shown that NK cells participate significantly in the onset and shaping of adaptive cellular immune responses, and increasingly these cells have become associated with protection from viral, bacterial and parasitic infections. Furthermore, they are substantially present in the placenta, apparently participating in the establishment of normal pregnancy. Consequently, NK cells have entered arenas of particular relevance in veterinary immunology. Limited data still exist on these cells in domestic animal species, much due to the lack of specific markers. However, bovine NK cells can be identified as NKp46 (CD335) expressing, CD3(−) lymphocytes. Recent studies have indicated a role for NK cells in important infectious diseases of cattle, and identified important bovine NK receptor families, including multiple KIRs and a single Ly49. In this review we will briefly summarize the current understanding of general NK cell biology, and then present the knowledge obtained thus far in the bovine species.     

Assessing the Sensitivity of Quantitative Structural Activity Analysis Models for Evaluating New Military Compounds

Quantitative structural activity relationship (QSAR) models are receiving wide use because of new regulations and public scrutiny regarding new compounds entered into commerce. Accordingly, the US Department of Defense (DoD) supported this study to evaluate QSAR modeling for energetic compounds. Four compounds proposed to replace ammonium perchlorate were examined: ammonium di(nitramido)amine (ADNA); 1,3,5,5-tetranitrohexahydropyrimidine (DNNC); 1,3,3,5,7,7-hexanitro-1,5-diazacyclooctane (HCO); and diammonium di(nitramido)dinitroethylene (ADNDNE). Currently used compounds were evaluated as analogues for those under development. Ammonium dinitramide (ADN) was the analogue for ADNA; hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) for DNNC; octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) for HCO; and 1,1-diamino-2,2-dinitroethene (FOX-7) for ADNDNE. QSAR analysis was performed with the US Environmental Protection Agency’s Estimation Program Interface (EPI) Suite?. The comparison of model estimates to literature values ranged from good-to-poor. Results suggested the proposed replacement compounds have low aquatic toxicities and little potential to bioaccummulate, but the uncertainty in the predictions indicates QSAR modeling with EPI Suite? is only useful for qualitative assessments of these proposed energetic compounds.     

Productivity and recovery of forage fish under climate change and fishing: North Sea sandeel as a case study

Forage fish occupy a central position in marine food‐webs worldwide by mediating the transfer of energy and organic matter from lower to higher trophic levels. The lesser sandeel (Ammodytes marinus) is one of the ecologically and economically most important forage fish species in the North‐east Atlantic, acting as a key prey for predatory fish and sea birds, as well as supporting a large commercial fishery. In this case study, we investigate the underlying factors affecting recruitment and how these in turn affect productivity of the North Sea sandeel using long‐term data and modelling. Our results demonstrate how sandeel productivity in the central North Sea (Dogger Bank) depends on a combination of external and internal regulatory factors, including fishing and climate effects, as well as density dependence and food availability of the preferred zooplankton prey (Calanus finmarchicus and Temora longicornis). Furthermore, our model scenarios suggest that while fishing largely contributed to the abrupt stock decline during the late 1990s and the following period of low biomass, a complete recovery of the stock to the highly productive levels of the early 1980s would only be possible through changes in the surrounding ecosystem, involving lower temperatures and improved feeding conditions. To that end, we stress the need for ecosystem‐based management accounting for multiple internal and external factors occurring within the broader context of the ecosystem in which forage fish species, such as sandeel, play an important and integral part.