Ozone inhalation activates stress-responsive regions of the CNS

Ozone (O(3)), a major component of air pollution, has considerable impact on public health. Besides the well-described respiratory tract inflammation and dysfunctions, there is accumulating evidence indicating that O(3) exposure affects brain functions. However, the mechanisms through which O(3) exerts toxic effects on the brain remain poorly understood. This work aimed at precisely characterizing CNS neuronal activation after O(3) inhalation using Fos staining in adult rat. We showed that, together with lung inflammation, O(3) exposure caused a sustained time- and dose-dependent neuronal activation in the dorsolateral regions of the nucleus tractus solitarius overlapping terminal fields of lung afferents running in vagus nerves. Furthermore, we highlighted neuronal activation in interconnected central structures such as the caudal ventrolateral medulla, the parabrachial nucleus, the central nucleus of the amygdala, the bed nucleus of the stria terminalis and the paraventricular hypothalamic nucleus. In contrast, we did not detect any neuronal activation in the thoracic spinal cord where lung afferents running in spinal nerves terminate. Overall, our results demonstrate that O(3) challenge evokes a lung inflammation that induces the activation of nucleus tractus solitarius neurons through the vagus nerves and promotes neuronal activation in stress-responsive regions of the CNS.     

A cross-sectional study to determine the seroprevalence of bluetongue virus serotype 8 in sheep and goats in 2006 and 2007 in the Netherlands

Background

In August 2006 a major epidemic of bluetongue virus serotype 8 (BTV8) started off in North-West Europe. In the course of 2007 it became evident that BTV8 had survived the winter in North-West Europe, re-emerged and spread exponentially. Recently, the European Union decided to start vaccination against BTV8. In order to improve the understanding of the epidemiological situation, it was necessary to execute a cross-sectional serological study at the end of the BT vector season. Cattle were the target species for cross-sectional serological studies in Europe at the end of 2006 and 2007. However, there was no information on the BTV8-seroprevalence in sheep and goats.

Results

On the basis of our cross-sectional study, the estimated seroprevalence of BTV8-exposed locations in the Netherlands in 2006 was 0% for goats (95% confidence interval: 0 – 5.6%) and 7.0% for sheep (95% confidence interval: 3.5 – 12.9%). The estimated seroprevalence of BTV-8 exposed locations in 2007 was 47% for goats (95% confidence interval: 36 – 58%) and 70% for sheep (95% confidence interval: 63 – 76%). There was a wide range in within-location seroprevalence in locations with goats and sheep (1 – 100%). A gradient in seroprevalence was seen, with the highest level of seroprevalence in the southern Netherlands, the area where the epidemic started in 2006, and a decreasing seroprevalence when going in a northern direction.

Conclusion

There is a much higher estimated seroprevalence of locations with goats exposed to BTV8 than can be inferred from the rather low number of reported clinical outbreaks in goats. This is probably due to the fact that clinical signs in infected goats are far less obvious than in sheep. The wide range in within-location seroprevalence observed means that the proportion of animals protected in 2008 by a natural infection in 2006 and/or 2007 can differ highly between flocks. This should be taken into account when vaccinating animals.

     

Local spread of classical swine fever upon virus introduction into The Netherlands: Mapping of areas at high risk

Background

In the recent past, the introduction of Classical Swine Fever Virus (CSFV) followed by between-herd spread has given rise to a number of large epidemics in The Netherlands and Belgium. Both these countries are pork-exporting countries. Particularly important in these epidemics has been the occurrence of substantial "neighborhood transmission" from herd to herd in the presence of base-line control measures prescribed by EU legislation. Here we propose a calculation procedure to map out "high-risk areas" for local between-herd spread of CSFV as a tool to support decision making on prevention and control of CSFV outbreaks. In this procedure the identification of such areas is based on an estimated inter-herd distance dependent probability of neighborhood transmission or "local transmission". Using this distance-dependent probability, we derive a threshold value for the local density of herds. In areas with local herd density above threshold, local transmission alone can already lead to epidemic spread, whereas in below-threshold areas this is not the case. The first type of area is termed 'high-risk' for spread of CSFV, while the latter type is termed 'low-risk'.

Results

As we show for the case of The Netherlands, once the distance-dependent probability of local transmission has been estimated from CSFV outbreak data, it is possible to produce a map of the country in which areas of high-risk herds and of low-risk herds are identified. We made these maps even more informative by estimating border zones between the two types of areas. In these border zones the risk of local transmission of infection to a nearby high-risk area exceeds a certain level.

Conclusion

The risk maps provide an easily understandable visualization of the spatial heterogeneities in transmission risk. They serve as a tool for area-specific designs of control strategies, and possibly also for spatial planning of areas where livestock farming is allowed. Similar risk maps can in principle be constructed for other highly-transmissible livestock infections that spread via neighborhood transmission.

     

Reduced Ca2+ current, charge movement, and absence of Ca2+ transients in skeletal muscle deficient in dihydropyridine receptor beta 1 subunit.

The Ca2+ currents, charge movements, and intracellular Ca2+ transients in mouse skeletal muscle cells homozygous for a null mutation in the cchb1 gene encoding the beta 1 subunit of the dihydropyridine receptor have been characterized. I beta null, the L-type Ca2+ current of mutant cells, had a approximately 13-fold lower density than the L-type current of normal cells (0.41 +/- 0.042 pA/pF at + 20 mV, compared with 5.2 +/- 0.38 pA/pF in normal cells). I beta null was sensitive to dihydropyridines and had faster kinetics of activation and slower kinetics of inactivation than the L-type current of normal cells. Charge movement was reduced approximately 2.8-fold, with Qmax = 6.9 +/- 0.61 and Qmax = 2.5 +/- 0.2 nC/microF in normal and mutant cells, respectively. Approximately 40% of Qmax was nifedipine sensitive in both groups. In contrast to normal cells, Ca2+ transients could not be detected in mutant cells at any test potential; however, caffeine induced a robust Ca2+ transient. In homogenates of mutant muscle, the maximum density of [3H]PN200-110 binding sites (Bmax) was reduced approximately 3.9-fold. The results suggest that the excitation-contraction uncoupling of beta 1-null skeletal muscle involves a failure of the transduction mechanism that is due to either a reduced amount of alpha 1S subunits in the membrane or the specific absence of beta 1 from the voltage-sensor complex.     

Hip joint replacement surgery for idiopathic osteoarthritis aggregates in families

In order to determine whether there is a genetic component to hip or knee joint failure due to idiopathic osteoarthritis (OA), we invited patients (probands) undergoing hip or knee arthroplasty for management of idiopathic OA to provide detailed family histories regarding the prevalence of idiopathic OA requiring joint replacement in their siblings. We also invited their spouses to provide detailed family histories about their siblings to serve as a control group. In the probands, we confirmed the diagnosis of idiopathic OA using American College of Rheumatology criteria. The cohorts included the siblings of 635 probands undergoing total hip replacement, the siblings of 486 probands undergoing total knee replacement, and the siblings of 787 spouses. We compared the prevalence of arthroplasty for idiopathic OA among the siblings of the probands with that among the siblings of the spouses, and we used logistic regression to identify independent risk factors for hip and knee arthroplasty in the siblings. Familial aggregation for hip arthroplasty, but not for knee arthroplasty, was observed after controlling for age and sex, suggesting a genetic contribution to end-stage hip OA but not to end-stage knee OA. We conclude that attempts to identify genes that predispose to idiopathic OA resulting in joint failure are more likely to be successful in patients with hip OA than in those with knee OA.     

Structure and regulation of the anthranilate synthase genes in Pseudomonas aeruginosa: II. Cloning and expression in Escherichia coli

The genes for the large and small subunits of anthranilate synthase (trpE and trpG, respectively) have been cloned from Pseudomonas aeruginosa PAC174 into E. coli by R-prime formation with the broad-host- range plasmid R68.44. Sequential subcloning into plasmid vectors reduced the active Pseudomonas DNA fragment to a length of 3.1 kb. We obtained evidence that this region contains the promoter for its own expression and retains a vestigial regulatory response to tryptophan scarcity or excess.      

Carbohydrate structure of glycoprotein 52 encoded by the polycythemia-inducing strain of Friend spleen focus-forming virus

The primary envelope (env) gene product of the polycythemia-inducing variant of Friend spleen focus-forming virus (F-SFFVP), representing a glycoprotein with an apparent Mr of 52,000 (gp52), was isolated from F-SFFVP-infected normal rat kidney cells metabolically labeled with [2-3H]mannose in the presence or absence of glucose. Structures of the oligosaccharides present were determined by micromethylation analysis, acetolysis, and digestion with exoglycosidases. Gp52 radiolabeled in the presence of glucose contains solely oligomannosidic glycans comprising 6 to 9 mannose residues (Man6-9GlcNAc2), some of which carry additional glucose. The structures of the glycans found reflect the typical intermediates of oligosaccharide processing. The glycosylation of gp52 isolated from glucose-deprived cells (-Glc), however, is characterized by increased amounts of Man5-7 species comprising other structural isomers. Only gp52 (-Glc) glycans are, in part, further processed yielding incomplete complex-type oligosaccharides. Our results demonstrate that the limited post-translational processing of the primary F-SFFVP env gene product is neither due to aberrant trimming of its oligomannosidic glycans nor due to transfer of immature lipid-linked oligosaccharide-intermediates as observed in glucose-starved cells.     

Structure elucidation of sulphated oligosaccharides from recombinant human tissue plasminogen activator expressed in mouse epithelial cells.

Sulphated N-linked carbohydrate chains isolated from recombinant human tissue plasminogen activator expressed in mouse epithelial (C127) cells were analysed as oligosaccharide alditols by methylation analysis, liquid secondary ion mass spectrometry, and one- and two-dimensional 1H-NMR spectroscopy. The results demonstrate that the major component has the following novel structure: NeuAc-alpha 2-6Gal beta 1-4GlcNAc beta 1-2[NeuAc alpha 2-3Gal beta 1- 4GlcNAc beta 1-4]-Man alpha 1-3[NeuAc alpha 2-3(SO4-6)Gal beta 1- 4-GlcNAc beta 1-2Man alpha 1-6]-Man beta 1-4GlcNAc beta 1- 4[Fuc alpha 1-6]GlcNAc-o1.