Perfluorooctanoic acid has persistent effects on peroxisome proliferation and related parameters in mouse liver

Male C57B1/6 mice were treated for 5 days with 0.05% perfluorooctanoic acid (PFOA) in their diet. This treatment resulted in a potent induction of peroxisomal fatty acid β-oxidation in the liver. In order to investigate recovery from treatment with PFOA, mice were given normal laboratory chow for up to 20 days after termination of PFOA administration. It was established that the activities of peroxisomal lauoryl-CoA oxidase and palmitoyl-CoA oxidation were still elevated 2–3 weeks after termination of treatment. The catalase activity recovered in the cytosolic fraction was also still significantly elevated after 20 days with normal laboratory chow. Furthermore, the protein content of the mitochondrial fraction was increased by PFOA and had not returned to control level at the end of the recovery period. Perfluorooctanoic acid also caused a persistent effect in omega hydroxylation of lauric acid (cytochrome P-452). The activities of cytosolic DT-diaphoreses and glutathione transferase were also enhanced by PFOA. However, these two enzymes recovered relatively rapidly from the treatment (2–20 days). This study reveals two different patterns of recovery from PFOA treatment, one involving parameters that recovered completely, or almost completely, from PFOA treatment after 20 days and another involving parameters that were still elevated at the end of the recovery period.     

Synthesis of urine drug metabolites: glucuronic acid glycosides of phenol intermediates

The investigation of drug metabolism requires substantial amount of metabolites. Isolation from urine is tedious, therefore, the material obtained by synthesis is preferred. Substantial amounts of three tentative drug metabolites, phenolic glucuronides, have been prepared using easily available glycosyl donors. The final products [3(2-N-methyl-N-isopropylaminoethoxy)phenyl] beta-D-glucopyranosiduronic acid, 4-amino-3,5-dimethylphenyl beta-D-glucopyranosiduronic acid and [2(S)-propanoyl-6-O-naphthyl] beta-D-glucopyranuronic acid are useful as, for example, reference material in metabolite investigations.     

Infestation by a Nalepella species induces emissions of α- and β-farnesenes, (−)-linalool and aromatic compounds in Norway spruce clones of different susceptibility to the large pine weevil

The emissions of spruce grafts (Picea abies), caused by infestation of an acarid species of the genus Nalepella were investigated. Volatiles of three clones, both healthy and infested, with different susceptibility to the large pine weevil Hylobius abietis were collected by solid phase micro extraction (SPME) and analyzed by gas chromatograph coupled to mass-spectrometry (GC-MS). In addition, enantiomers of the main chiral compounds were separated by a two dimensional-gas chromatograph (2D-GC). In the characteristic flower-like fragrances emitted by the infested grafts large amounts of E-β-farnesene, E,E-α-farnesene, (−)-linalool, methyl salicylate and minute amounts of benzyl alcohol, E-anethole, methyl benzoate, neral and geranial were found. All together, these compounds could explain the characteristic scent emitted by the infested seedlings. Large differences in the emissions of E-β-farnesene, E,E-α-farnesene and methyl salicylate were found between but not within the clones. Handling editor: Heikki Hokkanen.     

Genetic evaluation of an otter translocation program

The translocation of individuals from onepopulation to another is a common technique inwildlife conservation. However, the outcome oftranslocation programs is not always properlyevaluated and the relative contribution ofreleased individuals to the resident populationoften remains unknown. We used mitochondrialDNA and autosomal genetic markers to evaluatethe success of a translocation program ofEurasian otters (Lutra lutra) in Sweden.The program is regarded as successful becauseof subsequent population growths. Norwegianotters used for the restocking program could begenetically differentiated from Swedish otters.The releases took place at two sites. In anarea south of the first site, where 47 otterswere released, no genetic contribution of theintroduced animals to the population could beobserved and the genetic diversity was lowerthan before the releases. At the second site,the release of seven otters led to a change ingenetic composition of the resident population.The results of this study suggest that thegrowth of the otter population after therestocking may not be as dependent on thereleases as initially suspected. The geneticeffects of the translocations appear to berestricted to areas in the immediate vicinityof the release sites.     

Genotypic diversity and migration patterns of Phytophthora infestans in the Nordic countries

In this study we investigated the genotypic diversity and the migration patterns of Phytophthora infestans in the Nordic countries. Isolates of P. infestans from outbreaks in 43 fields sampled in 2008 were collected using stratified sampling with country, field, and disease foci as the different strata. Microsatellites were used as markers to determine the genotypic variation in the sampled material. The results show a high genotypic variation of P. infestans in the Nordic countries with most of the genotypes found only once among the collected isolates. The major part of the genotypic variation was observed within the fields, with low differentiation between the fields. The observed low association of alleles among loci is consistent with frequent sexual reproduction of P. infestans in the Nordic countries. Coalescence analyses did not support a single common population for the four countries, thus indicating some degree of geographic differentiation. The analyses of migration patterns showed differing levels of gene flow among the Nordic countries. No correlation between migration rates and geographical distance could be seen. This could be explained by different degrees of genetic similarity between the pathogen populations in the different countries.     

Hypertension, diabetes and overweight: looming legacies of the Biafran famine

Background

Sub-Saharan Africa is facing rapidly increasing prevalences of cardiovascular disease, obesity, diabetes and hypertension. Previous and ongoing undernutrition among pregnant women may contribute to this development as suggested by epidemiological studies from high income countries linking undernutrition in fetal life with increased burden of non-communicable diseases in later life. We undertook to study the risks for hypertension, glucose intolerance and overweight forty years after fetal exposure to famine afflicted Biafra during the Nigerian civil war (1967–1970).

Methods and Findings

Cohort study performed in June 27–July 31, 2009 in Enugu, Nigeria. Adults (n = 1,339) born before (1965–67), during (1968–January 1970), or after (1971–73) the years of famine were included. Blood pressure (BP), random plasma glucose (p-glucose) and anthropometrics, as well as prevalence of hypertension (BP>140/90 mmHg), impaired glucose tolerance (IGT; p-glucose 7.8–11.0 mmol/l), diabetes (DM; p-glucose ≥11.1 mmol/l), or overweight (BMI>25 kg/m²) were compared between the three groups. Fetal-infant exposure to famine was associated with elevated systolic (+7 mmHg; p<0.001) and diastolic (+5 mmHg; p<0.001) BP, increased p-glucose (+0.3 mmol/L; p<0.05) and waist circumference (+3cm, p<0.001), increased risk of systolic hypertension (adjusted OR 2.87; 95% CI 1.90–4.34), IGT (OR 1.65; 95% CI 1.02–2.69) and overweight (OR 1.41; 95% CI 1.03–1.93) as compared to people born after the famine. Limitations of this study include the lack of birth weight data and the inability to separate effects of fetal and infant famine.

Conclusions

Fetal and infant undernutrition is associated with significantly increased risk of hypertension and impaired glucose tolerance in 40-year-old Nigerians. Prevention of undernutrition during pregnancy and in infancy should therefore be given high priority in health, education, and economic agendas.     

CD4+ and CD8+ T Cells Can Act Separately in Tumour Rejection after Immunization with Murine Pneumotropic Virus Chimeric Her2/neu Virus-Like Particles

Background

Immunization with murine pneumotropic virus virus-like particles carrying Her2/neu (Her2MPtVLPs) prevents tumour outgrowth in mice when given prophylactically, and therapeutically if combined with the adjuvant CpG. We investigated which components of the immune system are involved in tumour rejection, and whether long-term immunological memory can be obtained.

Methodology and Results

During the effector phase in BALB/c mice, only depletion of CD4⁺ and CD8⁺ in combination, with or without NK cells, completely abrogated tumour protection. Depletion of single CD4⁺, CD8⁺ or NK cell populations only had minor effects. During the immunization/induction phase, combined depletion of CD4⁺ and CD8⁺ cells abolished protection, while depletion of each individual subset had no or negligible effect. When tumour rejection was studied in knock-out mice with a C57Bl/6 background, protection was lost in CD4^−/−CD8^−/− and CD4^−/−, but not in CD8^−/− mice. In contrast, when normal C57Bl/6 mice were depleted of different cell types, protection was lost irrespective of whether only CD4⁺, only CD8⁺, or CD4⁺ and CD8⁺ cells in combination were eradicated. No anti-Her2/neu antibodies were detected but a Her2/neu-specific IFNγ response was seen. Studies of long-term memory showed that BALB/c mice could be protected against tumour development when immunized together with CpG as long as ten weeks before challenge.

Conclusion

Her2MPtVLP immunization is efficient in stimulating several compartments of the immune system, and induces an efficient immune response including long-term memory. In addition, when depleting mice of isolated cellular compartments, tumour protection is not as efficiently abolished as when depleting several immune compartments together.     

Specific mediator inhibition by the NO donors SNP and NCX 2057 in the peripheral lung: implications for allergen-induced bronchoconstriction

Background

The aim of this study was to examine potential therapeutic effect of the two NO donors NCX 2057 (3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid) 4-(nitrooxy)butyl ester) and SNP (sodium nitroprusside) on the early allergic airway response in the peripheral lung.

Methods

The experiments were performed in guinea pig lung parenchyma (GPLP) derived from ovalbumin (OVA) sensitized guinea pigs. The effects of NCX 2057 and SNP were evaluated by contractile responses and mediator release during OVA challenge. The generation of nitrite and nitrate was assessed by chemiluminescence. Statistical analysis was evaluated by ANOVA.

Results

Cumulatively increasing concentrations of OVA (1–10,000 ng/ml) induced concentration-dependent contractions of the GPLP that were reduced by NCX 2057 (100 μM, p < 0.001) and SNP (100 μM, p < 0.05). Antigen-induced eicosanoid release was decreased by NCX 2057 (100 μM, p < 0.001) but not by SNP (100 μM), whereas the release of histamine was reduced by SNP (100 μM, p < 0.001) but not by NCX 2057 (100 μM). In addition, NCX 2057 (0.1–100 μM), but not SNP (0.1–100 μM), relaxed leukotriene D₄ (10 nM) precontracted GPLP (p < 0.01). The guanylyl cyclase inhibitor ODQ had no effect on the NCX 2057 mediated relaxation. SNP released significantly less nitrite than NCX 2057.

Conclusion

Although both SNP and NCX 2057 reduced the release of pro-inflammatory mediators, their profiles were distinctly different. Furthermore, NCX 2057 also induced smooth muscle dilation in the GPLP. The findings point to specific anti-inflammatory effects of different NO donors in the peripheral lung tissue.     

Correlational analysis for identifying genes whose regulation contributes to chronic neuropathic pain

Background

Descending facilitation, from the brainstem, promotes spinal neuronal hyperexcitability and behavioural hypersensitivity in many chronic pain states. We have previously demonstrated enhanced descending facilitation onto dorsal horn neurones in a neuropathic pain model, and shown this to enable the analgesic effectiveness of gabapentin. Here we have tested if this hypothesis applies to other pain states by using a combination of approaches in a rat model of osteoarthritis (OA) to ascertain if 1) a role for descending 5HT mediated facilitation exists, and 2) if pregabalin (a newer analogue of gabapentin) is an effective antinociceptive agent in this model. Further, quantitative-PCR experiments were undertaken to analyse the α₂δ-1 and 5-HT3A subunit mRNA levels in L3–6 DRG in order to assess whether changes in these molecular substrates have a bearing on the pharmacological effects of ondansetron and pregabalin in OA.

Results

Osteoarthritis was induced via intra-articular injection of monosodium iodoacetate (MIA) into the knee joint. Control animals were injected with 0.9% saline. Two weeks later in vivo electrophysiology was performed, comparing the effects of spinal ondansetron (10–100 μg/50 μl) or systemic pregabalin (0.3 – 10 mg/kg) on evoked responses of dorsal horn neurones to electrical, mechanical and thermal stimuli in MIA or control rats. In MIA rats, ondansetron significantly inhibited the evoked responses to both innocuous and noxious natural evoked neuronal responses, whereas only inhibition of noxious evoked responses was seen in controls. Pregabalin significantly inhibited neuronal responses in the MIA rats only; this effect was blocked by a pre-administration of spinal ondansetron. Analysis of α₂δ-1 and 5-HT3A subunit mRNA levels in L3–6 DRG revealed a significant increase in α₂δ-1 levels in ipsilateral L3&4 DRG in MIA rats. 5-HT3A subunit mRNA levels were unchanged.

Conclusion

These data suggest descending serotonergic facilitation plays a role in mediating the brush and innocuous mechanical punctate evoked neuronal responses in MIA rats, suggesting an adaptive change in the excitatory serotonergic drive modulating low threshold evoked neuronal responses in MIA-induced OA pain. This alteration in excitatory serotonergic drive, alongside an increase in α₂δ-1 mRNA levels, may underlie pregabalin's state dependent effects in this model of chronic pain.