Plasma leptin levels in pigs with different leptin and leptin receptor genotypes

A C3469T mutation at exon 3 of the pig leptin (Lep) gene has been genotyped in diverse pig breeds yielding controversial results with regard to its association with growth, fatness and carcass traits. A similar situation has been reported for a HpaII restriction fragment length polymorphism (RFLP) in the pig leptin receptor (Lepr) gene, where associations were found depending on the statistical model employed. The main objective of our work was to investigate if leptin plasma concentrations differ in pigs with different C3469T and Lepr HpaII RFLP genotypes. With this aim, we have measured plasma leptin levels at 160 days in 68 Landrace pigs with different Lep C3469T and Lepr HpaII RFLP genotypes. Neither Lep (TT: 11.68 ng/ml, TC: 10.71 ng/ml) nor Lepr (AA: 12.6 ng/ml, AB: 10.93 ng/ml, BB: 11.74 ng/ml) genotypes influenced significantly plasma Lep concentration. Moreover, we did not find any association between Lep and Lepr genotypes and phenotypic variation at growth and fatness traits in a commercial population of 320 Landrace pigs.     

Characterization of anti-channel catfish MHC class IIbeta monoclonal antibodies

This study characterizes four monoclonal antibodies (mAb) developed against the major histocompatibility complex (MHC) class II beta chain of the channel catfish, Ictalurus punctatus. Immunoprecipitations using catfish clonal B cells revealed that each of these mAbs immunoselected proteins of approximately 32 and 36 kD, which are of the appropriate sizes for MHC class II alpha and beta chains, respectively. Cell distribution studies using a fluorescence-activated cell sorter (FACS) combined with RT-PCR analyses demonstrated that MHC class II beta is expressed at a high density on catfish clonal macrophage, B and T cell lines, on alloantigen stimulated leukocytes, and on lipopolysaccharide-induced B-cell blasts. Collectively, these results demonstrate the potential importance of these antibodies as reagents in future studies dealing with the functional role of MHC class II molecules in immune recognition of self from non-self.     

Diagnosis of Taxus (yew) poisoning in a horse.

A 2-year-old bay Thoroughbred colt was found dead overnight in its stall without a known history of any illness, existing disease, or toxicant exposure. No information on the clinical signs before this animal's death was reported. A full necropsy was performed the next morning and revealed a mild to moderate degree of endocardial hemorrhages in both ventricles. Microscopic examination of the heart showed an acute mild multifocal necrosis of papillary muscles and ventricles. The stomach content contained approximately 2% Taxus alkaloids as determined by gas chromatography/mass spectrometry. In the past, diagnosis of Taxus poisoning has been mainly based on history of exposure and the presence of plant parts in the gastrointestinal tract. Pathological lesions associated with Taxus poisoning have not been published for horses. Therefore, this is the first report of cardiac lesions in a horse after lethal exposure to Taxus. On the basis of these findings, it is suggested that Taxus exposure needs to be considered in the differential diagnosis of horses that die suddenly or have cardiac lesions suggestive of Taxus exposure, even if intact plant parts are not identified in the stomach by the naked eye.     

Morphological and immunohistochemical characterisation of seminomas in Norwegian dogs

Background

Seminomas in the dog have traditionally been assumed to resemble human spermatocytic seminomas, based on their low malignancy and high occurrence in old individuals. However, recently published studies indicate that canine seminomas can be classified as classical and spermatocytic seminomas in a similar way as in man, and that classical seminomas comprise a substantial proportion of seminomas in the dog. These two factors both contribute to increasing the potential of canine seminoma as a relevant model for human testicular cancer. The aim of the present study was to characterise seminoma in Norwegian dogs using morphology and immunohistochemistry, and determine whether these tumours are comparable with human classical seminoma.

Methods

By applying diagnostic criteria from human pathology, 45 seminomas from the Norwegian Canine Cancer Register were examined histologically with hematoxylin and eosin (HE) and periodic acid-Schiff (PAS) stains. All sections were stained immunohistochemically with antibodies against human placental alkaline phosphatase (PLAP) and the transmembrane receptor c-KIT.

Results

Although two of the seminomas showed immunohistochemical staining characteristics indicative of classical seminoma (PLAP+/c-KIT+), all 45 examined seminomas were morphologically consistent with spermatocytic seminoma.

Conclusions

The value of canine seminoma as a model for SE in man remains unclear. Among the 45 investigated tumours from Norwegian dogs, none were classified as classical seminoma based on morphological criteria consistent with human seminomas. Regional or breed differences in the occurrence of classical seminoma in the dog, as well as the lack of uniform diagnostic criteria, might explain the discrepancy between the findings in the current study and the results presented by other authors.     

Fresh-stem bending of silver fir and Norway spruce

The bending and growth characteristics of large fresh stems from four silver fir (Abies alba Mill.) and three Norway spruce (Picea abies (L.) Karst.) trees were studied. Twenty logs taken from different stem heights were subjected to four-point bending tests. From the bending test records, we calculated stress-strain curves, which accounted for detailed log taper, shear deformation and self weight. From these curves we determined, among other parameters, the modulus of elasticity (MOE), the modulus of rupture (MOR) and the work absorbed in bending (W). No significant differences were found between species for the wood properties examined. Values of MOE, MOR and W generally decreased with stem height, with MOR in the range of 43 to 59 MPa and MOE ranging from 10.6 to 15.6 GPa. These MOE values are twice or more those reported for stems of young Sitka spruce (Picea sitchensis (Bong.) Carr.) trees. Based on the radial growth properties measured in discs from the logs, we calculated predicted values of MOE and MOR for the stem cross section. The predictions of MOE were precise, whereas those of MOR were approximate because of a complex combination of different failure mechanisms. Methods to test and calculate MOE, MOR and W for the stems of living trees are discussed with the aim of improving analyses of tree biomechanics and assessments of forest stability protection.     

Determination of oleandrin in tissues and biological fluids by liquid chromatography-electrospray tandem mass spectrometry

A rapid LC-MS/MS method, using a triple-quadrupole/linear ion trap mass spectrometer, was developed for the quantitative determination of oleandrin in serum, urine, and tissue samples. Oleandrin, the major cardiac glycoside of oleander (Nerium oleander L.), was extracted from serum and urine samples with methylene chloride and from tissues with acetonitrile. The tissue extracts were cleaned up using Florisil solid-phase extraction columns. Six replicate fortifications of serum and urine at 0.001 microg/g (1 ppb) oleandrin gave average recoveries of 97% with 5% CV (relative standard deviation) and 107% with 7% CV, respectively. Six replicate fortifications of liver at 0.005 microg/g (5 ppb) oleandrin gave average recoveries of 98% with 6% CV. This is the first report of a positive mass spectrometric identification and quantitation of oleandrin in tissue samples from oleander intoxication cases. The sensitivity and specificity of the LC-MS/MS analysis enables it to be the method of choice for toxicological investigations of oleander poisoning.     

Soil fertility in three cropping systems after conversion from conventional to organic farming

Abstract

Temporal changes in the scores of selected soil fertility indices were studied over six years in three different cases of organic crop rotation located in southern, eastern and central Norway. The cropping history and the initial scores of fertility indices prior to conversion to organic cropping differed between the sites. Crop yields, regarded as an overall, integrating fertility indicator, were in all rotations highly variable with few consistent temporal trends following the first year after conversion. On the site in eastern Norway, where conversion followed several years of all-arable crop rotations, earthworm number and biomass and soil physical properties improved, whereas the system was apparently degrading with regard to P and K trade balances and contents in soil. On the other two sites, the picture was less clear. On the southern site, which had a relatively fertile soil before conversion, the contents of soil organic matter and K decreased during the six-year period, but the scores of other fertility indices showed no trends. On the site in central Norway, there were positive trends for earthworm-related indices such as worm biomass and tubular biopores, and negative trends for soil porosity. The results, especially those from the eastern site, illustrate the general difficulty in drawing conclusions about overall fertility or sustainability when partial indicators show divergent trends. Consequently, the study gave no unambiguous support to the initial working hypothesis that organic farming increases inherent overall soil fertility, but rather showed that the effect varied among indicators and depended on status of the cases at conversion. It is concluded that indicators are probably better used as tools to learn about and improve system components than as absolute measures of sustainability.     

Assessment of Nitrogen Leaching at ICP-Waters Sites (Europe and North America)

The International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes (ICP-Waters) is designed to assess the degree and geographical extent of acidification of surface waters. During the last 20 years, international emission reduction measures in Europe and North America have resulted in a decrease in atmospheric S-deposition of up to 50%, while N-deposition has stayed almost constant. Empirical relationships between N-deposition and stages of nitrogen saturation are used to assess the importance of nitrogen leaching at the ICP-Waters sites in Europe and North America. There is a clear coherence between high N saturation stages and high N deposition loads and more than 50% of the analysed ICP Waters sites show a high degree of nitrogen saturation, defined as stages 2 or 3 in Stoddard's classification system. Significant leaching of inorganic N also occurs at most sites with deposition greater than 10 kg/ha/yr.