Carabid beetle (Coleoptera: Carabidae) assemblages in the intermediate successional stage after Mt. Bandai eruption of 1888: Effects of environmental variables on carabid beetles in the Urabandai area

We studied carabid beetle assemblage structure and species diversity in an intermediate successional stage (seral) forest established in areas affected by the 1888 eruption of Mt. Bandai and a climax forest that had not been affected by the eruption at the Urabandai area, Fukushima Prefecture, Japan. In total, 2,131 carabid beetles representing 31 species were collected using pitfall traps without bait. A comparison of carabid beetle assemblages between the two forest types revealed that the number of species observed was comparable, but their abundance was greater in the seral forest. The assemblage structure clearly differed between the two forest types. In the seral forest, forest generalists, such as Synuchus arcuaticollis and Pterostichus prolongatus, along with forest specialists including Carabus vanvolxemi and Pterostichus asymmetricus, were collected. In the climax forest, forest generalists, such as Synuchus cycloderus and Carabus albrechti tsukubanus, were more abundant than forest specialists. This suggests that the current seral forest in the Urabandai area possesses environmental variables that enable the coexistence of both forest specialist and generalist beetle species. A redundancy analysis showed that six species from the genera Synuchus and Pterostichus were associated with high canopy openness and high understory vegetation cover, whereas species recorded only in the climax forest were associated with deep litter. Therefore, it seems likely that carabid beetles in the Urabandai area were affected by these three environmental variables.     

Distribution of a Kidney Acid-ribonuclease-like Enzyme and the Other Ribonucleases in Bovine Organs and Body Fluids

To determine the distribution of a kidney acid RNase (RNase K₂) and other RNases, the levels of RNase K₂, RNase A, and seminal RNase (RNase Vs₁ in bovine tissues and body fluids were measured by enzyme immunoassay. The crude extracts of several tissues and body fluids were fractionated by phospho-cellulose column chromatography. The enzymatic activities at pH 7.5 and 6.0 and enzyme contents of each tube were measured by enzyme assay and enzyme immunoassay, respectively. In the pancreas, parotid gland, and heart, most RNase activity was due to a single peak of RNase A, but a small amount of RNase K₂ was always observed. In the kidney, there was about 5 times as much RNase K₂ as RNase A. In the lung, although RNase K₂ and RNase A were the major components, there are another two alkaline RNase peaks. In the spleen and liver, there are four RNases, two acid RNases, one of which is RNase K₂, and two alkaline RNases including RNase A. A new acid RNase (non RNase K₂-acid RNase) from both organs was immunologically the same. In serum, there are at least four RNases. By partial purification of serum RNases by phosphocellulose and heparin-Sepharose column chromatographies, at least 4 RNases, RNase A, RNase K₂ and the other two alkaline RNases, one of which is immunologically indistinguishable from liver alkaline RNase, were confirmed. The other serum alkaline RNase was immunologically related to lung and spleen alkaline RNases. In conclusion, in bovine tissues and body fluids there are at least 7 types of pyrimidine-base-specific RNases: brain RNase, seminal RNase, RNase A, RNase K₂, an acid RNase (RNase BSPJ, an alkaline RNase (RNase BL₄), and another alkaline RNase in serum.     

Lactobacillus gasseri SBT2055 Induces TGF-β Expression in Dendritic Cells and Activates TLR2 Signal to Produce IgA in the Small Intestine

Probiotic bacteria provide benefits in enhancing host immune responses and protecting against infection. Induction of IgA production by oral administration of probiotic bacteria in the intestine has been considered to be one reason for this beneficial effect, but the mechanisms of the effect are poorly understood. Lactobacillus gasseri SBT2055 (LG2055) is a probiotic bacterium with properties such as bile tolerance, ability to improve the intestinal environment, and it has preventive effects related to abdominal adiposity. In this study, we have found that oral administration of LG2055 induced IgA production and increased the rate of IgA⁺ cell population in Peyer''s patch and in the lamina propria of the mouse small intestine. The LG2055 markedly increased the amount of IgA in a co-culture of B cells and bone marrow derived dendritic cells (BMDC), and TLR2 signal is critical for it. In addition, it is demonstrated that LG2055 stimulates BMDC to promote the production of TGF-β, BAFF, IL-6, and IL-10, all critical for IgA production from B cells. Combined stimulation of B cells with BAFF and LG2055 enhanced the induction of IgA production. Further, TGF-β signal was shown to be critical for LG2055-induced IgA production in the B cell and BMDC co-culture system, but TGF-β did not induce IgA production in a culture of only B cells stimulated with LG2055. Furthermore, TGF-β was critical for the production of BAFF, IL-6, IL-10, and TGF-β itself from LG2055-stimulated BMDC. These results demonstrate that TGF-β was produced by BMDC stimulated with LG2055 and it has an autocrine/paracrine function essential for BMDC to induce the production of BAFF, IL-6, and IL-10.     

Paradoxical effects of chondroitin sulfate-E on Japanese encephalitis viral infection

Glycosaminoglycans (GAGs) have diverse functions in the body and are involved in viral infection. The purpose of this study was to evaluate the possible roles of the E-disaccharide units GlcAβ1–3GalNAc(4,6-O-disulfate) of chondroitin sulfate (CS), a GAG involved in neuritogenesis and neuronal migration, in Japanese encephalitis virus (JEV) infection. Soluble CS-E (sCS-E) derived from squid cartilage inhibited JEV infection in African green monkey kidney-derived Vero cells and baby hamster kidney-derived BHK cells by interfering with viral attachment. In contrast, sCS-E enhanced viral infection in the mouse neuroblastoma cell line Neuro-2a, despite the fact that viral attachment to Neuro-2a cells was inhibited by sCS-E. This enhancement effect in Neuro-2a cells seemed to be related to increased viral RNA replication and was also observed in a rat infection model in which intracerebral coadministration of sCS-E with JEV in 17-day-old rats resulted in higher brain viral loads than in rats infected without sCS-E administration. These results show the paradoxical effects of sCS-E on JEV infection in different cell types and indicate that potential use of sCS-E as an antiviral agent against JEV infection should be approached with caution considering its effects in the neuron, the major target of JEV.     

Euryspongins A–C,three new unique sesquiterpenes from a marine sponge Euryspongia sp.

Three new unique sesquiterpenes, euryspongins A–C (1–3), were isolated from a marine sponge Euryspongia sp. collected at Iriomote Island, Okinawa, Japan. Compound 1 possessed a bicyclic furanosesquiterpene structure with six- and eight-membered rings, whereas compounds 2 and 3 had an α,β-unsaturated-γ-lactone ring instead of the furan ring in 1. Only five natural products in this class have been reported, and compounds 1–3 are the sixth–eighth examples of natural products. Compounds 1–3 had no inhibition effect against PTP1B, an important target enzyme for the treatment of diabetes, while the dehydro derivative of 1 [dehydroeuryspongin A (4)] exhibited inhibitory activity (IC₅₀ = 3.6 μM).