Muscle carbonic anhydrase III levels in normal and muscular dystrophia afflicted chickens

Background

The levels and immunohistochemical localization of muscle carbonic anhydrase III (CA-III) in healthy chickens and in muscular dystrophia affected (DA) chickens show that the muscles of diseased animal undergo a progressive increase of enzyme activity.

Methods

An enzyme-linked immunoassay was used to assess the CA-III levels in the muscles and other tissues from eight normal White Leghorn chickens and in two chickens with muscular dystrophy. Immunohistochemical localization of the enzyme in the muscles of these animals was also determined.

Results

The levels of CA-III in the tensor fasciae latae and the superficial pectoral muscles of the DA chickens were higher than the level in normal chickens. The concentrations of CA-III in erythrocytes and plasma from diseased chickens were approximately 15-fold and 1.4-fold higher than in the normal chickens, respectively. In the superficial pectoral and the tensor fasciae latae muscles of diseased chickens, the numbers of strongly stained and weakly stained fibers were greater than that in the normal chickens.

Conclusion

The levels of CA-III in the superficial pectoral muscle, the tensor fasciae latae muscle, plasma and erythrocytes from the chickens with muscular dystrophy were higher than found in normal chickens.     

Impacts of invasive Iris pseudacorus L. (yellow flag) establishing in an abandoned urban pond on native semi-wetland vegetation

Iris pseudacorus L., intentionally introduced in Japan as an ornamental plant and to improve aquatic environments, has been declared a noxious species in the Invasive Alien Species Act of Japan due to the suspected high ecological risks to the local species and ecosystems. Although prompt responses to I. pseudacorus have been sought to conserve local biodiversity, knowledge about its invasiveness is lacking. Here, we report the relationship between the establishment of I. pseudacorus and floristic changes in semi-wetland vegetation of an abandoned urban pond (Aoike), Nara City, Nara Prepecture, Japan. In total, 64 vascular plants were recorded in the pond, of which 50 were native species, seven were naturalized non-native, and seven were invasive species. On the other hand, most of these vascular plants (42 species) were grassland species and only several aquatic plants (10 species) were found in this study pond. The number of vascular plant species decreased significantly at quadrats with a coverage of I. pseudacorus above 50%. In addition, tendencies of lower number of native species and concomitant higher number of invasive species were found with increasing coverage of I. pseudacorus. From these results, we suggest that it is important to preferentially manage sites where the coverage of I. pseudacorus is above 50%, in order to preserve the local biodiversity. Additionally, as recommended in the literature, it is essential that the cut reproductive organs are kept submerged under deep water for an effective control of I. pseudacorus.     

Oocyte maturation and active motility of spermatozoa are triggered by retinoic acid in pen shell <Emphasis Type="Italic">Atrina pectinata</Emphasis>

For recovery of the declining population of pen shells in the wild, the production of pen shell juveniles for transplantation or aquaculture is underway in Japan. For more stable juvenile production, artificial fertilization methods for pen shells are needed, but methods to induce oocyte maturation (meiosis resumption) used in other bivalves, which make oocytes fertilizable, were ineffective for pen shells. Here, we report evidence showing that retinoic acid (RA) has strong activity in inducing oocyte maturation and activating sperm motility in pen shells. Treatment of fully developed oocytes with 1.0 μM all-trans-RA (at-RA) induced germinal vesicle breakdown, a typical morphological sign of oocyte maturation, but 1.0 μM at-retinol and at-retinal, 2 mM ammonia, and 1.0 μM serotonin were ineffective. Treatment with at-RA for 30 min was sufficient for oocyte maturation and was more potent than its isomers, 9-cis- and 13-cis-RA. Parallel results were obtained for sperm motility activation. Oocyte responsiveness to at-RA increased during the final stage of ovary development. Artificial fertilization was successful only with the oocytes treated with at-RA, and fertilized eggs developed to D-shaped (veliger) larvae without apparent morphological abnormalities. These results indicate the possible application of RA for the artificial fertilization of pen shells.     

Changes in above- and belowground biomass in early successional tropical secondary forests after shifting cultivation in Sarawak,Malaysia

Uncertainties in the rate of biomass variation with forest ageing in tropical secondary forests, particularly in belowground components, limit the accuracy of carbon pool estimates in tropical regions. We monitored changes in above- and belowground biomass, leaf area index (LAI), and biomass allocation to the leaf component to determine the variation in carbon accumulation rate with forest age after shifting cultivation in Sarawak, Malaysia. Nine plots in a 4-year-old forest and fourteen plots in a 10-year-old forest were monitored for 5 and 7 years, respectively. Forest and plant part biomass were calculated from an allometric equation obtained from the same forest stands. Both above- and belowground biomass increased rapidly during the initial decade after abandonment. In contrast, a much slower rate of biomass accumulation was observed after the initial decade. LAI also increased by approximately double from the 4-year-old to 10-year-old forest, and then gently increased to the 17-year-old forest. We also found that allocation variation in leaf biomass and nitrogen was closely related to the rate of biomass accumulation as a forest aged. During the first decade after abandonment, a high biomass and nitrogen allocation to the leaf component may have allowed for a high rate of biomass accumulation. However, reduction in those allocations to leaf component after the initial decade may have helped to suppress the biomass accumulation rate in older secondary forests. Roots accounted for 14.0–16.1% of total biomass in the 4–17-year-old abandoned secondary forests. We also verified the model predicted values for belowground biomass by Cairns et al. (1997) and Mokany et al. (2006), although both models overestimated the values throughout our data sets by 45–50% in the 10-year-old forest. The low root:shoot ratio in the secondary forests may have caused this overestimation. Therefore, our results suggest that we should modify the models to estimate belowground biomass considering the low root:shoot ratio in tropical secondary forests.     

Synthesis and antifungal activity of the proposed structure of a volatile compound isolated from the edible mushroom Hypsizygus marmoreus

We synthesized the proposed structure of an antifungal compound detected in the culture broth of the edible mushroom Hypsizygus marmoreus. Using the Evans aldol and Abiko–Masamune aldol reactions as the key steps, we synthesized all of the stereoisomers of the compound with high stereoselectivity. The GC retention times and the fragmentation patterns in the mass spectra of the synthesized isomers did not match those of the natural product. Therefore, this result may imply that it is necessary to reisolate the natural product and reconsider its structure. All of the synthesized isomers were found to exhibit antifungal activity against the phytopathogenic fungus Alternaria brassicicola. Due to their simple structures, the obtained isomers could be lead compounds for new pesticides.     

Disinfectant resistance of Salmonella in in vitro contaminated poultry house models and investigation of efficient disinfection methods using these models

Salmonellaenterica subsp. enterica (Salmonella) shows disinfectant resistance by forming biofilms on solid surfaces. However, efficient disinfection methods to eliminate Salmonella biofilms from farms have not yet been examined in detail. In this study, more than 80% of Salmonella strains from farms in Yamagata prefecture, Japan, were biofilm producers. Regardless of the extent of their biofilm formation ability, their biofilms were highly resistant to hypochlorous acid on plastic surfaces. To establish efficient disinfection methods in farms, we developed in vitro Salmonella-contaminated poultry house models by depositing dust on ceramic and stainless-steel carriers in poultry houses for one month and culturing a representative Salmonella strain on the carriers. Biofilm-like structures, including Salmonella-like cells, were observed on the models by scanning electron microscopy. Salmonella was not efficiently removed from the models even by cleaning with a surfactant at 25/65°C and disinfection with quaternary ammonium compound or hypochlorous acid at 25°C; on the contrary, viable Salmonella cells increased in some tests under these conditions, suggesting that these models successfully simulate the highly persistent characteristics of Salmonella in farms. However, the persistent bacterial cells were markedly decreased by soaking in 65°C surfactant followed by rinsing with 80°C water, additional cleaning using chlorine dioxide or disinfection with dolomitic lime, suggesting the effectiveness of these methods against Salmonella in farms. Since many different disinfection conditions may be easily tested in laboratories, our models will be useful tools for establishing effective and practical disinfection methods in farms.     

Reproduction affects partitioning between new organs of a pulse of 15N applied during seed ripening in Fagus crenata

Seasonal internal nitrogen (N) cycling is an important strategy for trees to uncouple growth from N acquisition. While N uptake, allocation and storage has been intensively studied in association with leaf phenology and vegetative growth, influence of reproduction on these key processes is still poorly understood. Therefore, we applied pulse ¹⁵N labelling to three fruiting and three non-fruiting trees in a 92-year-old Fagus crenata forest on 18 July and traced ¹⁵N content per organ dry mass (¹⁵N_excess) in all new shoot organs from the upper crowns periodically until leaf fall. The amount of ¹⁵N_excess recovered in the whole new shoots in fruiting trees did not differ from non-fruiting individuals, although up to 70% of ¹⁵N_excess was recovered in fruits of fruiting trees but 87% in leaves of non-fruiting individuals. In addition, dramatic increase in ¹⁵N_excess amount in nuts was accompanied by about twofold increase in nut N content. These results indicate that new N uptake from the soil contributed greatly to seed ripening, which in turn resulted in less allocation to leaves in fruiting trees. In non-fruiting individuals, on the other hand, ¹⁵N_excess allocated to leaves was not accompanied by concomitant increase in leaf N content because biomass growth had ceased when ¹⁵N was applied. These results suggest that N uptake in the late growing season contributed to internal N storage in non-fruiting trees. These reproduction-related variations in seasonal N cycle have implications for N dynamics in the plant–soil system during environmental change.