Bisphenol-A (BPA) affects reproductive formation across generations in mice

To understand effects of Bisphenol-A (BPA) exposure on the reproductive organ across generations, we analyzed morphology of the uterus and ovary, and the methylation pattern of HOXA10 gene of the 2(nd) generation. Pregnant mice (F0) were treated with sc injection of BPA in sesame oil at various doses of 0-1,000 mg/kg Bwt on days 12-16 of gestation. Their offspring (F1) were bred by foster mice, and the offspring (F2) from F1 mice were prepared. That is, F1 mice experienced in utero BPA exposure during the developmental period of reproductive organs, while F2 mice did not at all. Using these F2 mice, the present study was carried out. Comparing to the control, the body weights in BPA exposure groups were significantly increased. Correlating with the increase of body weight, the relative weights of the ovary and uterus in each group were decreased. The histological analysis revealed expansion or emphraxis of the uterine lumen and partial loss of the uterine epithelium. Unmethylation of HOXA10 gene in the uterus was observed in the intron region. The present study suggested that BPA exposure to F0 mice could affect reproductive organ of F2 mice who were not exposed to BPA.     

Molecular and phenotypic characteristics of Salmonella enterica serovar 4,5,12:i:- isolated from cattle and humans in Iwate Prefecture, Japan

A total of 15 isolates of Salmonella enterica serovar 4,5,12:i:- obtained from diseased cows and patients in Iwate Prefecture, Japan, were characterized to clarify the genetic basis of this serovar. S. Typhimurium- specific IS200 was detected from all the isolates. A 94-kb plasmid and the spvB gene were detected from all but one of the 15 isolates. The results of PCR mapping of the fljAB operon and its flanking regions indicate that there are deletions or mutations in this chromosomal region. These data suggest that the 15 isolates are monophasic variants of S. Typhimurium. Epidemiological relationships between the isolates obtained from cattle and humans were not suspected based on the comparison of data employing plasmid profiling and pulsed-field gel electrophoresis.     

A weeding-duration model for <Emphasis Type="Italic">Larix kaempferi</Emphasis> plantations in Hokkaido,northern Japan

In this study, a weeding-duration model for Larix kaempferi plantations was developed that employs a generalized linear model. The number of years that weeding is necessary is the response variable, and elevation, slope, maximum snow depth, annual precipitation, geological type, soil type, site index, slope aspect, and vegetation type are explanatory variables. Among the explanatory variables, geological type, soil type, slope aspect, and vegetation type are categorical data. We assumed a Poisson distribution for the response variable. The link function was log. Among the models that could be developed from these variables, we chose the model with the smallest Akaike’s information criterion (AIC). The weeding-duration model can be written as follows: years that weeding is necessary = Exp (−0.0172833 × site index + 0.0014053 × maximum snow depth (cm) + 1.7417731). The results of this study imply that weeding of Larix kaempferi plantations is needed for more years as the maximum snow depth increases and fewer years as the site index increases. This model is useful for cost–benefit analyses of afforestation or reforestation with Larix kaempferi.     

Distribution of the androgen receptor in the diencephalon and the pituitary gland in goats: Co-localisation with corticotrophin releasing hormone, arginine vasopressin and corticotrophs

Previously it has been shown that androgen suppresses transportation-induced increases in plasma adrenocorticotropic hormone (ACTH), possibly by suppressing the secretion of corticotrophin releasing hormone (CRH) or arginine vasopressin (AVP) from the hypothalamus, or secretion of ACTH from the pituitary gland. The aim of the present study was to examine androgen target sites in the caprine diencephalon and pituitary gland using immunohistochemical methods. The androgen receptor (AR) was expressed strongly in the bed nucleus of the stria terminalis, the medial preoptic area, the arcuate nucleus, the ventromedial hypothalamic nucleus and the suprachiasmatic nucleus in the diencephalon. Between 8% and 11% of CRH and AVP neurons in the paraventricular hypothalamic nucleus (PVN) expressed AR. In the pituitary gland, 7.1% of corticotrophs expressed AR. The results are consistent with the proposal that androgen acts directly and indirectly on CRH and/or AVP neurons in the PVN. The possibility of a direct action of androgen on the corticotrophs in the pituitary gland was also considered.     

Muscle type‐specific effect of myostatin deficiency on myogenic regulatory factor expression in adult double‐muscled Japanese Shorthorn cattle

To clarify muscle type‐specific effect of myostatin on myogenic regulatory factors (MRFs), we examined mRNA expression of MRFs in five skeletal muscles of normal (NM) and myostatin‐deficient double‐muscled (DM) adult Japanese Shorthorn cattle by quantitative reverse‐transcribed PCR. Among the four MRFs, namely, Myf5, MyoD, myogenin, and MRF4, MyoD expression was different among the muscles of the DM cattle (P < 0.01) but not of the NM cattle. Meanwhile, MyoD expression was significantly elevated only in masseter (MS) muscle in the DM cattle due to the myostatin deficiency (P < 0.05). Myf5 and MRF4 expression in semitendinosus (ST) was higher in the DM than in the NM cattle (P < 0.05). According to analysis of myosin heavy chain (MyHC) isoform expression, more MyHC‐2x and ‐2a and less ‐slow isoforms were expressed in the longissimus and ST muscles compared to the MS muscle in both cattle (P < 0.05), but no significant difference in MyHC expression was observed between the NM and DM cattle. Taken together, myostatin has influences on Myf5 and MRF4 expression in faster‐type muscles and on MyoD expression in slower‐type muscles, suggesting a possible muscle type‐specific effect of myostatin in skeletal muscle growth and maintenance.     

Effect of stocking density and addition of proteins on larval survival in Japanese flounder, Paralichthys olivaceus

The effects of larval density, rearing media, and protein additions on fish larval survival were tested by rearing larvae in small containers. Yolk-sac larvae of Japanese flounder, Paralichthys olivaceus, were transferred 1 day after hatching to plastic dishes and cell-culture microplates by Pasture pipette at densities ranging from 0.3 to 30 individuals/ml and incubated at 16 °C without food. Dead larvae were removed and counted every 12 h. Three peaks of larval mortality were observed: the first peak appeared just after the transfer, the second corresponded to the completion of yolk absorption, and the third occurred 10–12 days after the transfer. Since about 50% of larvae survived until the third peak, it was clear that mortality at the second peak (completion of yolk absorption; equivalent to the first feeding) was not due to starvation. At the first mortality peak, better survival was unexpectedly recorded at higher larval densities (30 individuals/ml), suggesting that some material beneficial for survival is derived from the larvae. This idea was further supported by the improved survival in media previously used to rear larvae at high densities. The addition of bovine serum albumin (BSA) at 10 μg/ml effectively reduced mortality in microplates and in 30-l tanks. To reduce the larval mortality just after handling, addition of egg white at a dilution rate of 1/30,000 (vol/vol) or less is recommended as a practical alternative to BSA. Since the addition of polyethylene glycol 6000 (1 μg/ml) also effectively reduced mortality, reduction in mortality could not be attributed to a specific mechanism. The precise determination of the magnitude and timing of larval mortality was attained through the use of small containers, and a method to prevent mortality due to handling was identified in this study. These types of tests may allow the logical evaluation and establishment of better rearing procedures for seed production in aquaculture.     

Possible implication of metalloproteinases in post-mortem tenderization of fish muscle

ABSTRACT: It is suspected that the proteolytic breakdown of extracellular matrix proteins is responsible for the postmortem tenderization of fish muscle during chilled storage. In order to identify the type(s) of proteinases involved in this phenomenon, the effect of proteinase inhibitors, EDTA (ethylenediamine tetraacetic acid), 1,10-phenanthroline, ρ-APMSF [(ρ-amidinophenyl) methanesulfonyl fluoride hydrochloride] and E-64 [ L - trans -epoxysuccinyl-leucylamido-(4-guanidinobutane)] on tenderization was investigated by using Japanese flounder. Proteinase inhibitor solution was injected into a blood vessel in a caudal portion of live flounder and the firmness of muscle was then evaluated as a shear force value at 0 h and 6 h after death. Metalloproteinase inhibitors, EDTA and 1,10-phenanthroline, significantly suppressed postmortem tenderization. These findings suggest that metalloproteinases are candidates for proteinases involved in the postmortem tenderization of fish muscles. Although not significantly, p -APMSF, a serine proteinase inhibitor, partially suppressed muscle tenderization, which suggests that serine proteinases are also implicated in postmortem tenderization. A cysteine proteinase inhibitor, E-64, showed no effect, suggesting that cysteine proteinases are not involved.     

Improved waterlogging tolerance of barley (Hordeum vulgare) by pretreatment with ethephon

ABSTRACT

Root growth into hypoxic or anoxic waterlogged soil relies on internal aeration in plants. The plant hormone ethylene helps adapt to waterlogging by inducing the formation of aerenchyma, which provides a low-resistance pathway for the transport of oxygen from the shoot to the root apex. Waterlogging-susceptible crops including barley start to form aerenchyma after suffering waterlogging stress. But waterlogging can be fatal if aerenchyma formation is not fast enough. Here, we investigated whether pre-treating barley with ethephon, an ethylene-releasing agrochemical, could improve its tolerance to mimicked waterlogging conditions (using stagnant deoxygenated agar nutrient solution). In barley growing in aerated nutrient solution, ethephon treatment enhanced aerenchyma formation at the root tips and induced the development of shorter and shallower roots. Pre-treating barley leaves also delayed waterlogging-caused whiting and increased the percentages of viable root-tips under waterlogging conditions. However, the pretreatment did not noticeably increase fresh weight or shoot length. Further studies are needed to optimize ethephon treatment conditions to improve barley production under waterlogged conditions.     

Evaluation of changes in left ventricular myocardial function observed in canine myocardial dysfunction model using a two-dimensional tissue tracking technique

This study was conducted to assess the ability of two-dimensional tissue tracking (2DTT) to evaluate changes in left ventricular (LV) myocardial function associated with sustained high electrical pacing. Pacemakers were implanted at the right ventricular (RV) apex of five female Beagles, and sustained high electrical pacing of 250 beats per minute (bpm) was performed for three consecutive weeks. Conventional echocardiography and 2DTT were performed at baseline, and at every week for three weeks with pacing. The baseline parameters were then compared to those of weeks 1, 2, and 3. Three weeks of pacing resulted in significant reduction of radial and circumferential global strains (p < 0.001). Regional analysis revealed reduction of segmental strains in both radial and circumferential directions, as well as increased dyssynchrony after three weeks of pacing in the radial direction (p = 0.0007). The results of this study revealed the ability of 2DTT to measure radial and circumferential strains in dogs with sustained high-electrical pacing, and allowed assessment of global and regional myocardial function and the degree of dyssynchrony.