The effect of estrogen on phosphorylation of prolactin in the mouse pituitary gland

Several studies have indicated that prolactin (PRL) assumes oligomeric, proteolytically cleaved, phosphorylated and glycosylated forms. Phosphorylated PRL (PPRL) is considered to be the most important posttranslationally modified form in the rat. In the present study, we examined whether or not PRL is present in the mouse pituitary gland in the phosphorylated form. Mouse pituitary PRL was digested with acid phosphatase, resolved by two-dimensional gel electrophoresis, stained with Coomassie brilliant blue, and then immunoblotted against the anti-PRL, anti-phosphoserine and anti-phosphothreonine antibodies. We also examined whether PRL is phosphorylated by protein kinases and semi-quantified the ratios of PPRL to PRL in the pituitary gland. The results indicated that three types of PRL are present in the pituitary glands of both male and female mice. One was non-phosphorylated (isoform 1), and the other two were immunoreactive to anti-phosphoserine (isoform 2) and/or anti-phosphothreonine (isoform 3) antibodies. The ratio between isoforms 2 and 1 of the 30-day-old female mice was higher than that of the 20-day-old female mice. However, the ratios among the three isoforms in the male pituitary glands did not differ with age. The ratio of PPRL to isoform 1 was obviously reduced after ovariectomy (OVX), and it recovered with estrogen replacement. These results suggest that estrogen influences PRL phosphorylation in female mice.     

Improved porcine model for Shiga toxin‐producing Escherichia coli infection by deprivation of colostrum feeding in newborn piglets

Porcine edema disease (ED) is a toxemia caused by enteric infection with Shiga toxin 2e (Stx2e)‐producing Escherichia coli (STEC). ED occurs most frequently during the weaning period and is manifested as emaciation associated with high mortality. In our experimental infection with a specific STEC strain, we failed to cause the suppression of weight gain in piglets, which is a typical symptom of ED, in two consecutive experiments. Therefore, we examined the effects of deprivation of colostrum on the sensitivity of newborn piglets to STEC infection. Neonatal pigs were categorized into two groups: one fed artificial milk instead of colostrum in the first 24 h after birth and then returned to the care of their mother, the other breastfed by a surrogate mother until weaning. The oral challenge with 10¹¹ colony‐forming units of virulent STEC strain on days 25, 26 and 27 caused suppression of weight gain and other ED symptoms in both groups, suggesting that colostrum deprivation from piglets was effective in enhancing susceptibility to STEC. Two successive STEC infection experiments using colostrum‐deprived piglets reproduced this result, leading us to conclude that this improved ED piglet model is more sensitive to STEC infection than the previously established models.     

翻耙补播对科尔沁碱化草地土壤理化性质和生物活性的影响

对科尔沁地区碱化草甸草地翻耙补播沙打旺后的土壤理化性质和土壤生物活性的变化进行了研究.结果表明,翻耙补播改良后草地综合生产性能得到明显改善,土壤容重、pH、含盐量和碱化度降低,土壤含水量和孔隙度增加,土壤有机质和N、P、K等养分含量增加;同时,土壤微生物C、N的含量以及土壤酶的活性也得到较大幅度提高.     

Insecticidal activity and microsomal metabolism of biooxidizable lindane analogs

The insecticidal activity of lindane analogs, in which some chlorine atoms were replaced by other groups susceptible to microsomal oxidative metabolism, was determined against mosquitos, house flies, and German cockroaches. When tested with a synergist, piperonyl butoxide, one of the methylthio analogs was as active as lindane, whereas several others were also highly active. By examining the ratio of synergized and unsynergized LD₅₀ values (synergistic ratio value), the highly insecticidal methylthio, methoxy, and methyl analogs appear to undergo metabolic detoxication effectively in house flies. By means of in vitro metabolism experiments using microsomal fraction from house fly abdomen, the methoxy, ethoxy, and methylthio analogs were shown to be metabolized rapidly at similar rates. The synergized insecticidal activities of these compounds against various insect species relate linearly with each other, suggesting that the oxidative degradation is inhibited by the synergist to a similar extent and that the transport process to the site of action is not a limiting factor in determining the relative insecticidal activity.     

α-Melanocyte-stimulating hormone directly increases the plasma calcitonin level and involves calcium metabolism in goldfish

International Aquatic Research - The effects of α-melanocyte-stimulating hormone (α-MSH) on calcium metabolism were examined with goldfish. The scales on the left side of goldfish bodies...     

Effects of high dose of vitamin A on reproduction and egg quality of Japanese flounder Paralichthys olivaceus

ABSTRACT: The present study was conducted to investigate the effects of dietary vitamin A on reproduction and egg quality in Japanese flounder Paralichthys olivaceus . Broodstock were fed experimental pellets containing two levels of vitamin A [11 × 10³ IU/100 g (control diet; CD), 337 × 10³ IU/100 g (experimental diet; ED)] for approximately 2 months before spawning and during the spawning period. Two groups of five females (average weight 1.4 kg) and 10 males (average weight 0.7 kg) were randomly allocated to two 30 m³ indoor tanks. Total egg production of the CD group was slightly higher than the ED group. Percentage of buoyant eggs and hatching rate of the ED group were significantly higher than the CD. In other egg quality parameters, such as percentage abnormal larvae and starvation tolerance of larvae, no notable difference was found between these two groups. At the end of the experiment, the skin color of broodstock in the ED group was darker than that of the CD group. Vitamin A content in eggs of the ED group was significantly higher than that of the CD group. However, the difference in vitamin A content in eggs between the ED and CD groups was much smaller than that in the liver of the females between the two groups. These results indicate that feeding broodstock a higher level of vitamin A increases the vitamin A content in eggs but does not affect egg quality in Japanese flounder because excess dietary vitamin A was stored mainly in the broodstocks' liver.     

Factors affecting agonistic interactions of pigs after regrouping in pens with a box

To determine the factors affecting agonistic interactions after regrouping, 24 pigs were allocated to six pens that each had a box. Half of the pigs were experienced in using the box. One castrated male and one female pig were transferred from each pen to another pen at random. The number of pigs attacked was particularly large for the pigs that had no experience in using the box and were transferred on the first day ( P <  0.05). The duration of access to the box was markedly longer for the pigs that had experience in using the box and were not transferred on the first day ( P <  0.05). The number and duration of attacks were significantly larger and longer toward unfamiliar individuals than toward familiar ones (both P < 0.01). The number of attacks toward the same sex was significantly larger than toward the opposite sex ( P <  0.01). A negative correlation was found between the number of agonistic interactions on the first day and the range of body weights in the pen mates ( r =  −0.78, P  = 0.07). In conclusion, regrouping with unfamiliar individuals should be avoided, but when unavoidable, the following methods are recommended to reduce agonistic interactions: (1) ensure the intruders are experienced in using a box, (2) move experienced intruders in with residents that have no experience in using a box, (3) mix different sexes, and (4) have wide variations in body weights in a pen.     

Interdigital involvement in a case of primary cutaneous canine histoplasmosis in Japan

A 5-year-old male Siberian husky bred outdoor in Tokyo had a swollen paw with interdigital granulomatous lesions in the left hindlimb. The dog had no apparent pulmonary or gastrointestinal involvement. Histopathological analysis of the skin lesions demonstrated yeast-like organisms predominantly within macrophages. Sequence analysis of fungal ribosome RNA gene isolated from a paraffin sample revealed a 100% homology with the teleomorph of Histoplasma capsulatum. The present case may support the concept of primary cutaneous canine histoplasmosis as an endemic phenotype recognized in Japan.     

Canopy temperature on clear and cloudy days can be used to estimate varietal differences in stomatal conductance in rice

Leaf photosynthetic potential, a major determinant of yield potential in rice, is mostly explained by stomatal conductance (g_s) as well as leaf N content (Rubisco protein content). Therefore, the rapid and precise evaluation of g_s as well as leaf N content would be a valuable addition to rice breeding programs aimed at improved yield potential. We established a simple method based on infrared thermography to estimate varietal differences in g_s. Seven rice varieties were cultivated in two-row plots in 2007, and canopy temperatures in three varieties, including a control variety, Koshihikari, were simultaneously measured to determine canopy temperature difference (CTd) between Koshihikari and the other varieties on clear days. The varieties Takanari, Habataki, and TUAT1-5-6a displayed significantly (P < 0.05) lower leaf temperature and higher g_s and leaf photosynthetic rate (P_n) than Koshihikari. CTd was closely correlated with g_s and P_n. These results indicate that CTd may be useful as a relative index to estimate varietal differences in g_s. A significant CTd was still observed even under cloudy conditions in 2008. Takanari and TUAT1-5-6a had lower leaf temperature than Koshihikari on cloudy days as well as on clear days. Subsequent investigation of photosynthetic light response curves revealed that Takanari and TUAT1-5-6a had higher g_s and P_n than Koshihikari under lower irradiance. These results suggest that infrared thermography may be a simple method of evaluating varietal differences in g_s through CTd, and that it may be practicable even under cloudy conditions.