Epizootiology of avian influenza: effect of season on incidence in sentinel ducks and domestic turkeys in Minnesota

Sentinel ducks and domestic turkey flocks were monitored for influenza infection during a 4-year period. The onset of infection among ducks was similar each year, occurring in late July or early August. Influenza in turkeys was also shown to be seasonal, but the usual onset was 6 to 8 weeks after the detection of influenza in sentinel ducks. Possible explanations for the delayed infection in turkeys are (i) increased waterfowl activity associated with fledging and congregating in late summer and early fall; (ii) vectors transmitting virus from the waterfowl habitat to poultry farms; (iii) cooler environmental temperature, allowing prolonged virus viability; (iv) cooler surface water temperature, allowing prolonged virus viability; (v) groundwater contamination from contaminated surface water; and (vi) virus adaptation in domestic turkeys before infection is detected. We conclude that ducks are not only a natural reservoir of influenza but also have a seasonal infection that appears to be related to seasonal influenza outbreaks in domestic turkeys in Minnesota. However, only some influenza A virus isolates circulating among waterfowl at any given time appear capable of causing detectable infection in turkeys. It is speculated that the seasonal infection in migratory waterfowl may also be related to seasonal influenza infections in other species including humans.     

Transmembrane and cytoplasmic domain sequences demonstrate at least two expressed bovine MHC class I loci

We have used the polymerase chain reaction to amplify cDNA from expressed bovine major histocompatibility complex class I genes. Sequences obtained from transmembrane and cytoplasmic domains were used to identify the number of expressed alleles. Data from three animals suggest that there are four major expressed alleles, representing the products of two (or more) loci. We have also demonstrated the presence of an alternatively spliced mRNA, which has been observed in five animals. The alternative splicing removes exon 7 (the major site of class I phosphorylation), which predicts a truncated molecule with a cytoplasmic portion 16 amino acids shorter than usual. This phenomenon was detected for only a single class I allele within each individual. Correspondence to: S. A. Ellis.     

Correction to: Industrial antifoam agents impair ethanol fermentation and induce stress responses in yeast cells

Applied Microbiology and Biotechnology - The article “Industrial antifoam agents impair ethanol fermentation and induce stress responses in yeast cells” was originally published Online...     

Functional imaging using computational fluid dynamics to predict treatment success of mandibular advancement devices in sleep-disordered breathing

Mandibular advancement devices (MADs) have emerged as a popular alternative for the treatment of sleep-disordered breathing. These devices bring the mandibula forward in order to increase upper airway (UA) volume and prevent total UA collapse during sleep. However, the precise mechanism of action appears to be quite complex and is not yet completely understood; this might explain interindividual variation in treatment success. We examined whether an UA model, that combines imaging techniques and computational fluid dynamics (CFD), allows for a prediction of the treatment outcome with MADs. Ten patients that were treated with a custom-made mandibular advancement device (MAD), underwent split-night polysomnography. The morning after the sleep study, a low radiation dose CT scan was scheduled with and without the MAD. The CT examinations allowed for a comparison between the change in UA volume and the anatomical characteristics through the conversion to three-dimensional computer models. Furthermore, the change in UA resistance could be calculated through flow simulations with CFD. Boundary conditions for the model such as mass flow rate and pressure distributions were obtained during the split-night polysomnography. Therefore, the flow modeling was based on a patient specific geometry and patient specific boundary conditions. The results indicated that a decrease in UA resistance and an increase in UA volume correlate with both a clinical and an objective improvement. The results of this pilot study suggest that the outcome of MAD treatment can be predicted using the described UA model.     

Interactions between Genetic Variants in AMH and AMHR2 May Modify Age at Natural Menopause

The onset of menopause has important implications on women’s fertility and health. We previously identified genetic variants in genes involved in initial follicle recruitment as potential modifiers of age at natural menopause. The objective of this study was to extend our previous study, by searching for pairwise interactions between tagging single nucleotide polymorphisms (tSNPs) in the 5 genes previously selected (AMH, AMHR2, BMP15, FOXL2, GDF9). We performed a cross-sectional study among 3445 women with a natural menopause participating in the Prospect-EPIC study, a population-based prospective cohort study, initiated between 1993 and 1997. Based on the model-based multifactor dimensionality reduction (MB-MDR) test with a permutation-based maxT correction for multiple testing, we found a statistically significant interaction between rs10407022 in AMH and rs11170547 in AMHR2 (p = 0.019) associated with age at natural menopause. Rs10407022 did not have a statistically significant main effect. However, rs10407022 is an eQTL SNP that has been shown to influence mRNA expression levels in lymphoblastoid cell lines. This study provides additional insights into the genetic background of age at natural menopause and suggests a role of the AMH signaling pathway in the onset of natural menopause. However, these results remain suggestive and replication by independent studies is necessary.     

Evidence for a New Avian Paramyxovirus Serotype 10 Detected in Rockhopper Penguins from the Falkland Islands

The biological, serological, and genomic characterization of a paramyxovirus recently isolated from rockhopper penguins (Eudyptes chrysocome) suggested that this virus represented a new avian paramyxovirus (APMV) group, APMV10. This penguin virus resembled other APMVs by electron microscopy; however, its viral hemagglutination (HA) activity was not inhibited by antisera against any of the nine defined APMV serotypes. In addition, antiserum generated against this penguin virus did not inhibit the HA of representative viruses of the other APMV serotypes. Sequence data produced using random priming methods revealed a genomic structure typical of APMV. Phylogenetic evaluation of coding regions revealed that amino acid sequences of all six proteins were most closely related to APMV2 and APMV8. The calculation of evolutionary distances among proteins and distances at the nucleotide level confirmed that APMV2, APMV8, and the penguin virus all were sufficiently divergent from each other to be considered different serotypes. We propose that this isolate, named APMV10/penguin/Falkland Islands/324/2007, be the prototype virus for APMV10. Because of the known problems associated with serology, such as antiserum cross-reactivity and one-way immunogenicity, in addition to the reliance on the immune response to a single protein, the hemagglutinin-neuraminidase, as the sole base for viral classification, we suggest the need for new classification guidelines that incorporate genome sequence comparisons.Viruses from the Paramyxoviridae family have caused disease in humans and animals for centuries. Over the last 40 years, many paramyxoviruses isolated from animals and people have been newly described (16, 17, 22, 29, 31, 32, 36, 42, 44, 46, 49, 58, 59, 62-64). Viruses from this family are pleomorphic, enveloped, single-stranded, nonsegmented, negative-sense RNA viruses that demonstrate serological cross-reactivity with other paramyxoviruses related to them (30, 46). The subfamily Paramyxovirinae is divided into five genera: Respirovirus, Morbillivirus, Rubulavirus, Henipavirus, and Avulavirus (30). The Avulavirus genus contains nine distinct avian paramyxovirus (APMV) serotypes (Table ​(Table1),1), and information on the discovery of each has been reported elsewhere (4, 6, 7, 9, 12, 34, 41, 50, 51, 60, 68).

TABLE 1.

Characteristics of prototype viruses APMV1 to APMV9 and the penguin virus

Functional Characterization of the Short Neuropeptide F Receptor in the Desert Locust,Schistocerca gregaria

Whereas short neuropeptide F (sNPF) has already been reported to stimulate feeding behaviour in a variety of insect species, the opposite effect was observed in the desert locust. In the present study, we cloned a G protein-coupled receptor (GPCR) cDNA from the desert locust, Schistocerca gregaria. Cell-based functional analysis of this receptor indicated that it is activated by both known isoforms of Schgr-sNPF in a concentration dependent manner, with EC₅₀ values in the nanomolar range. This Schgr-sNPF receptor constitutes the first functionally characterized peptide GPCR in locusts. The in vivo effects of the sNPF signalling pathway on the regulation of feeding in locusts were further studied by knocking down the newly identified Schgr-sNPF receptor by means of RNA interference, as well as by means of peptide injection studies. While injection of sNPF caused an inhibitory effect on food uptake in the desert locust, knocking down the corresponding peptide receptor resulted in an increase of total food uptake when compared to control animals. This is the first comprehensive study in which a clearly negative correlation is described between the sNPF signalling pathway and feeding, prompting a reconsideration of the diverse roles of sNPFs in the physiology of insects.     

Avian influenza viruses and avian paramyxoviruses in wintering and breeding waterfowl populations in North Carolina, USA

Although wild ducks are recognized reservoirs for avian influenza viruses (AIVs) and avian paramyxoviruses (APMVs), information related to the prevalence of these viruses in breeding and migratory duck populations on North American wintering grounds is limited. Wintering (n=2,889) and resident breeding (n=524) ducks were sampled in North Carolina during winter 2004-2006 and summer 2005-2006, respectively. Overall prevalence of AIV was 0.8% and restricted to the winter sample; however, prevalence in species within the genus Anas was 1.3% and was highest in Black Ducks (7%; Anas rubripes) and Northern Shovelers (8%; Anas clypeata). Of the 24 AIVs, 16 subtypes were detected, representing nine hemagglutinin and seven neuraminidase subtypes. Avian paramyxoviruses detected in wintering birds included 18 APMV-1s, 15 APMV-4s, and one APMV-6. During summers 2005 and 2006, a high prevalence of APMV-1 infection was observed in resident breeding Wood Ducks (Aix sponsa) and Mallards (Anas platyrhynchos).