Wnt3a-mediated formation of phosphatidylinositol 4,5-bisphosphate regulates LRP6 phosphorylation

The canonical Wnt-beta-catenin signaling pathway is initiated by inducing phosphorylation of one of the Wnt receptors, low-density lipoprotein receptor-related protein 6 (LRP6), at threonine residue 1479 (Thr1479) and serine residue 1490 (Ser1490). By screening a human kinase small interfering RNA library, we identified phosphatidylinositol 4-kinase type II alpha and phosphatidylinositol-4-phosphate 5-kinase type I (PIP5KI) as required for Wnt3a-induced LRP6 phosphorylation at Ser1490 in mammalian cells and confirmed that these kinases are important for Wnt signaling in Xenopus embryos. Wnt3a stimulates the formation of phosphatidylinositol 4,5-bisphosphates [PtdIns (4,5)P2] through frizzled and dishevelled, the latter of which directly interacted with and activated PIP5KI. In turn, PtdIns (4,5)P2 regulated phosphorylation of LRP6 at Thr1479 and Ser1490. Therefore, our study reveals a signaling mechanism for Wnt to regulate LRP6 phosphorylation.     

Analysis of factors affecting the electric conductivity of cow's milk--breed, locale, season

The problem was studied in a set of 678 mammary glands of 212 cows - crossbreds between the Holstein-Friesian breed with the Slovak Spotted cattle, crossbreds of the Black-Pied Lowland and Bohemian Spotted breed, and three-way crossbreds of the Black-Pied Lowland, Swedish White and Bohemian Spotted cattle. The confrontation of the confidence intervals of milk conductivity (MC) in healthy mammary glands at alpha = 0.05 showed that in the crossbreds of the Black-Pied Lowland cattle the MC was statistically significantly higher than in the breed types of the Holstein-Friesian cattle. The MC values decrease when there is a larger proportion of the blood of beef-and-dairy cattle (Slovak Spotted and Bohemian Spotted breeds). The locality where the stock was kept was found to act as an important factor underlying MC only in cases when both the geographical conditions and breed proportions were different. In a set homogenized with respect to the breeds, statistically significant differences in MC were demonstrated between the spring and summer season, spring and autumn, summer and autumn, and autumn and winter season.     

The structure of confined oxygen in silica xerogels

The microscopic structure of oxygen confined in silica xerogels has been studied as a function of temperature. In large pores, a crystalline solid forms with a structure consistent with that of the bulk. The size of the crystallites is much larger than the pore size, indicating that cooperative effects among pores are important in freezing. As the pore size is decreased, a crossover occurs where solidification results in an amorphous phase in the pores. The resulting amorphous phase is solid but is less ordered than the liquid phase.     

The effect of bentazone manufactured in Czechoslovakia on the synthesis of bacterial proteins in the rumen of sheep]

The effect of the perorally ingested pesticide bentazone (195 mg.kg-1) of Czechoslovak origin on the amino acid composition of proteins of bacteria adhering to the ventral and dorsal ruminal wall investigated in six sheep. Proteosynthesis of adherent bacteria was studied by a modified and quantified elution method (elution of bacteria by an isotonic buffered solution at 4 degrees C). By the latter, a concentrate of undamaged bacteria a adhering to the sheep ruminal epithelium could be obtained. The yield of the method was estimated by scanning electrone microscopy and it was 93.3% (Legáth et al., 1990). The high correlation coefficient (r = 0.94, p < 0.01) suggested that in comparison with the control group of sheep, bentazone in the diet did not have a marked effect on the amount of amino acids in hydrolyzates of bacteria adhering to the dorsal and ventral ruminal epithelium. From the analysis of the single amino acids, it however follows that bentazone in the feeding ration caused significant changes in the concentrations of some amino acids in the proteins of bacteria adhering to the epithelium in the ventral and dorsal part of the rumen (p < 0.05) (Tab. I, II). In both topographico-anatomical parts of the rumen phenylalanine levels significantly increased whereas those of alanine and glycine decreased (Fig. 1). Pesticides can be one of the factors that negatively affect the biosynthetic processes in the rumen of ruminants.(ABSTRACT TRUNCATED AT 250 WORDS)     

Interrelation between profile test indicators in the decreased milk acidity syndrome in cows

The internal environment of high-yielding dairy cows was investigated in relation to 36 variables of the blood metabolic profile, blood serum, milk and urine, with the incidence of reduced titration acidity milk syndrome. The levels of variables were confronted with references values. At the same time the statistical significance of differences of arithmetical means from the reference mean was calculated. Correlation analysis of all variables yielded 630 correlation coefficients. Certain correlations were represented in form of correlogrammes. It has been demonstrated that the reduced titration acidity milk syndrome with the lowest values of 1.9 ml 0.25N NaOH per 100 ml occurred after administration of the feed ration deficient both in digestible crude protein and starch units (nutritive ratio 1:7.5) which contained unsafe grass haylage with a high content of ammonia (232.9 mg per 100 g). A highly significant negative correlation was proved to exist between lactose concentration and pH value of milk (r = -0.913); the regression equation (lactose) is 36.997--4.7536 (pH).     

Temporo-spatial and kinetic gait parameters in English setter dogs

Walking analysis systems have begun to be used in veterinary medicine in recent years. The pressure-sensitive walkway is one of the systems through which we can obtain temporo-spatial and kinetic variables of walking. Therefore, the aim of this study was to investigate the walking characteristics of English Setter dogs using a pressure-sensitive system. Twenty-five English Setter dogs were included in the study. Temporo-spatial and kinetic gait parameters were obtained with the pressure-sensitive walkway system. Centre of pressure values were taken separately for the forelimbs and hindlimbs and were statistically analysed. The force values in the forelimb were found to be greater than in the hindlimb during walking. According to the results of dynamic pedobarographic evaluation, the highest-pressure values were found at the 2nd and 3rd digital pads for the forelimbs and on the 3rd and 4th digital pads for the hindlimbs. During the stance, 64.58% of the weight was found to be on the forelimbs. No difference was found between the forelimbs and the hindlimbs in centre of pressure analysis. As conclusion, the gait data obtained from the English Setter dogs can be used in future research to identify animals that may have neurological or orthopaedic problems.