Infection Prevalence of Microsporidia Vairimorpha (Nosema) spp. in Japanese Bumblebees.

Microsporidia are spore-forming intracellular parasites of various invertebrates and vertebrates. Vairimorpha bombi negatively affects the fitness of bumblebees and its prevalence correlates with declining bumblebee populations. The invasive alien species Bombus terrestris colonized Japan and possibly introduced new parasites. To assess the infection prevalence of V. bombi in Japanese bumblebees and B. terrestris, we investigated V. bombi infections using PCR and microscopy. The prevalence of sporulating V. bombi infections in three Bombus s. str. species/subspecies was low, whereas that of non/low-sporulating Vairimorpha sp. infections in three Diversobombus species/subspecies was high. Invasive B. terrestris showed low prevalence of non/low-sporulating V. bombi infections and shared the same V. bombi haplotype with B. hypocrita found in Hokkaido, where B. terrestris is present, and in Honshu, where B. terrestris is absent. Although V. bombi may have been introduced with B. terrestris colonies imported from Europe, it seems to be originally distributed in Japan. Furthermore, a new Vairimorpha sp. was found in Japanese bumblebee species. V. bombi and Vairimorpha sp. showed different organ and host specificities in bumblebees. There are no reports on the specific effects of other Vairimorpha spp. on bumblebees; further studies are needed to clarify the individual characteristics of Vairimorpha spp.

An in vitro study on the selection of surfactants for removal of cream denture adhesives from dentures and their application to denture cleaners.

Purpose Denture adhesives improve the stability of incompatible dentures; however, complete removal of adhesives after use is difficult. Only a few studies have focused on the removal of denture adhesives. Hence, this study aimed to assess the efficacy of surfactants in removing cream denture adhesives from acrylic resin materials.Methods Solutions of twelve surfactants with various hydrophilic-lipophilic balance (HLB) values were prepared. Two cream denture adhesives, colored for visualization, were spread onto transparent acrylic resin plates. After immersion into surfactant solutions, the effects of the surfactants on residual adhesives were evaluated. We also investigated the effect of denture cleaners (with or without the surfactants) on the removability of adhesives and artificial oily dirt, and their effects on the surface properties of denture materials. The obtained data were analyzed using appropriate statistical methods.Results Five surfactants [BT-5, BL-4.2, BT-7, BT-9, and Triton X-100 (TX)] with HLB values in the 10.5-13.5 range effectively removed adhesives. Addition of BT-9 and TX (HLB=13.5) to denture cleaners improved the adhesives' removal. Furthermore, the addition of TX to the cleaners did not interfere with the removal of artificial oily dirt and did not damage the denture materials' surface.Conclusions Surfactants with HLB values in the 10.5-13.5 range are suitable for removal of cream denture adhesives from acrylic resin materials. In particular, TX (HLB=13.5) efficiently removes adhesives without damaging denture materials or impairing original detergency.

Efficacy of bone grafting materials in preserving the alveolar ridge in a canine model.

Preservation of the alveolar ridge after tooth extraction is an essential component for ideal implant positioning. Furthermore, preservation of bone around the implant after implant placement is an essential component for implant treatment. We aimed to evaluate the efficacy of bone grafting materials in preserving the alveolar ridge after implant placement. Implants were placed in regenerated bone without grafting material or with beta-tricalcium phosphate, bovine bone substitute, or carbonate apatite transplantation. In all groups, the bone healed and the implants were successfully placed within the bone. No significant differences in insertion torque and implant stability quotient values were found. The amount of bone around the implant 5 weeks after implant placement was significantly reduced in the bovine bone substitute group; however, implants placed in regenerated bone achieved sufficient initial fixation and osseointegration.

Human cathelicidin antimicrobial peptide LL-37 promotes lymphangiogenesis in lymphatic endothelial cells through the ERK and Akt signaling pathways.

LL-37, the only member of the cathelicidin family of cationic antimicrobial peptides in humans has been shown to exhibit a wide variety of biological actions in addition to its antimicrobial activity. However, the lymphangiogenic effect of LL-37 has not been elucidated yet. In this study, we examined the effects of LL-37 on lymphangiogenesis and evaluated the underlying molecular mechanisms. LL-37 treatment significantly increased the migration and tube-like formation of human dermal lymphatic microvascular endothelial cells (HDLECs) and promoted the expression of lymphangiogenic factor in HDLECs. Treatment with LL-37 increased phosphorylation of ERK and Akt proteins in HDLECs, and pretreatment with ERK and Akt inhibitors significantly blocked the LL-37-induced HDLEC migration and tube-like formation. Furthermore, to investigate the involvement of formyl peptide receptor-like 1 (FPRL1) signaling in LL-37-induced lymphangiogenesis, HDLECs were treated with an FPRL1 antagonist. Pretreatment with the FPRL1 antagonist inhibited LL-37-induced phosphorylation of ERK and Akt proteins and attenuated LL-37-induced HDLEC migration and tube-like formation. These data indicated that LL-37 induces lymphangiogenesis in lymphatic endothelial cells via FPRL1, and the activation of the ERK and Akt-dependent signaling pathways.

Direct and sensitive detection of a microsporidian parasite of bumblebees using loop-mediated isothermal amplification (LAMP).

The reduction of bumblebee populations has been reported in the last decades, and the microsporidian parasite Nosema bombi is considered as one of the factors contributing to such reduction. Although the decline of bee populations affects both wild plants and human food supply, the effects of Nosema spp. infections are not known because it is difficult to obtain infective spores from wild bees due to their low prevalence. Microscopical observation of fecal samples or midgut homogenates and/or PCR are generally used for N. bombi detection. However, the germination rate of microsporidian spore declines if they are kept at 4 °C for a long time or frozen. It is therefore crucial to minimize the diagnosis and isolation time of infective spores from field-collected samples. Therefore, we performed a loop-mediated isothermal amplification (LAMP) assay for the direct detection of N. bombi in bumblebee midgut homogenates. Using this method, we could detect N. bombi from individuals from which it was visible under the microscope and directly from wild individuals.

Impact of Oral Intake of Glucosylceramide Extracted from Pineapple on Xerostomia: A Double-Blind Randomized Cross-Over Trial.

Background: The aim of this double-blind randomized cross-over trial was to evaluate the effect of oral intake of glucosylceramide extracted from pineapple on oral moisture and xerostomia symptoms. Methods: Sixteen participants who had xerostomia symptoms were randomly allocated into two groups. One group received, as test samples, tablets containing glucosylceramide extracted from pineapple (GCP) followed by placebo tablets. The other group received the test samples in the reverse order. Participants were instructed to take tablets of the first test sample once a day (after breakfast) for two consecutive weeks. Then, after a washout period of four weeks, participants were instructed to take the other test sample for two consecutive weeks. The oral moisture level of the lingual mucosa, xerostomia symptoms, and the number of fungiform papillae was evaluated. Results: The oral moisture significantly increased, and the visual analog scale (VAS) of "How is the dryness of your mouth?" significantly improved after GCP tablets intake and not after placebo tablets intake. The number of fungiform papillae was not significantly different following the intake of GCP tablets or placebo tablets. Conclusion: Results suggested that oral intake of GCP may improve the moisture level and xerostomia symptoms.

Vascular endothelial growth factor-C promotes human mesenchymal stem cell migration via an ERK-and FAK-dependent mechanism.

Vascular endothelial cell growth factor-C (VEGF-C) is a member of the VEGF family and plays a role in various biological activities. VEGF-C enhances proliferation and migration of lymphatic endothelial cells and vascular endothelial cells through VEGF receptor 2 (VEGFR2) and/or receptor 3 (VEGFR3), and thereby induces lymphangiogenesis or angiogenesis. However, it remains unclear whether VEGF-C promotes the migration of mesenchymal stem cells (MSCs). Here, we investigated the effects of VEGF-C on the migration of MSCs and evaluated the underlying molecular mechanisms. VEGF-C treatment significantly induced the migration of MSCs, which is accompanied by the promotion of actin cytoskeletal reorganization and focal adhesion assembly. VEGF-C treatment enhanced the phosphorylation of VEGFR2 and VEGFR3 proteins in MSCs, and pretreatment with VEGFR2 and VEGFR3 kinase inhibitors effectively suppressed the VEGF-C-induced MSC migration. In addition, VEGF-C treatment promoted phosphorylation of ERK and FAK proteins in MSCs, and inhibition of VEGFR2 and VEGFR3 signaling pathways abolished the VEGF-C-induced activation of ERK and FAK proteins. Furthermore, treatment with ERK and FAK inhibitors suppressed VEGF-C-induced actin cytoskeletal reorganization and focal adhesion assembly, and then significantly inhibited MSCs migration. These results suggest that VEGF-C-induced MSC migration is mediated via VEGFR2 and VEGFR3, and follows the activation of the ERK and FAK signaling pathway. Thus, VEGF-C may be valuable in tissue regeneration and repair in MSC-based therapy.

Dissection of autophagy in tobacco BY-2 cells under sucrose starvation conditions using the vacuolar H(+)-ATPase inhibitor concanamycin A and the autophagy-related protein Atg8.

Tobacco BY-2 cells undergo autophagy in sucrose-free culture medium, which is the process mostly responsible for intracellular protein degradation under these conditions. Autophagy was inhibited by the vacuolar H(+)-ATPase inhibitors concanamycin A and bafilomycin A1, which caused the accumulation of autophagic bodies in the central vacuoles. Such accumulation did not occur in the presence of the autophagy inhibitor 3-methyladenine, and concanamycin in turn inhibited the accumulation of autolysosomes in the presence of the cysteine protease inhibitor E-64c. Electron microscopy revealed not only that the autophagic bodies were accumulated in the central vacuole, but also that autophagosome-like structures were more frequently observed in the cytoplasm in treatments with concanamycin, suggesting that concanamycin affects the morphology of autophagosomes in addition to raising the pH of the central vacuole. Using BY-2 cells that constitutively express a fusion protein of autophagosome marker protein Atg8 and green fluorescent protein (GFP), we observed the appearance of autophagosomes by fluorescence microscopy, which is a reliable morphological marker of autophagy, and the processing of the fusion protein to GFP, which is a biochemical marker of autophagy. Together, these results suggest the involvement of vacuole type H(+)-ATPase in the maturation step of autophagosomes to autolysosomes in the autophagic process of BY-2 cells. The accumulation of autophagic bodies in the central vacuole by concanamycin is a marker of the occurrence of autophagy; however, it does not necessarily mean that the central vacuole is the site of cytoplasm degradation.