Microplastics reduced posterior segment regeneration rate of the polychaete Perinereis aibuhitensis.

Microplastics are found in abundance in and on coastal sediments, and yet, whether exposure to this emerging pollutant negatively impact whole organism function is unknown. Focusing on a commercially important polychaete, Perinereis aibuhitensis, we demonstrated that presence of microplastics increased mortality and reduced the rate of posterior segment regeneration. The impact of the micro-polystyrene beads was size-dependent with smaller beads (8-12µm in diameter) being more detrimental than those bigger in size (32-38µm). This observed difference suggests microplastic impact could be affected by physical properties, e.g., sinking speed, surface area available for sorption of chemicals and bacteria, and selective feeding behaviors of the target organism.

Immunogenicity and reactogenicity of tetravalent vaccine for measles, mumps, rubella and varicella (MMRV) in healthy children: a meta-analysis of randomized controlled trials.

BACKGROUND: Varicella is a highly infectious childhood disease. Tetravalent measles-mumps-rubella-varicella (MMRV) vaccine was introduced as one-syringe dose. OBJECTIVE: To evaluate the immunogenicity and reactogenicity of MMRV vaccine versus trivalent MMR with varicella (V) vaccines in healthy children and to assess the respective safety issue. METHODS: Randomized controlled trials (RCTs) were searched from the OVID databases. Trials were eligible if healthy children were randomized to receive MMRV or MMR+V vaccine. Seroconversions in serum antibody titers were the primary outcomes; adverse events were the secondary outcomes. RESULTS: Ten RCTs with 8961 healthy children were identified. MMRV and MMR+V vaccines showed comparable immunogenicity against measles (relative risk [RR] = 0.99, 95% CI = 0.98-1.00), mumps (RR = 0.99, 95% CI = 0.97-1.00), rubella (RR = 1.00, 95% CI = 1.00-1.01) and varicella (RR = 0.98, 95% CI = 0.95-1.01). At least 93% of children in both groups had seroconverted within 6 weeks. MMRV group showed significantly higher incidences of fever (RR = 1.19, 95% CI = 1.09-1.31) and rash (RR = 1.23, 95% CI = 1.06-1.43). CONCLUSIONS: The immunogenicities of MMRV and MMR+V vaccines were comparable in healthy children; however, MMRV vaccination showed higher incidences of fever and rash.

Molecular evidence shows low species diversity of coral-associated hydroids in Acropora corals.

A novel symbiosis between scleractinians and hydroids (Zanclea spp.) was recently discovered using taxonomic approaches for hydroid species identification. In this study, we address the question whether this is a species-specific symbiosis or a cosmopolitan association between Zanclea and its coral hosts. Three molecular markers, including mitochondrial 16S and nuclear 28S ribosomal genes, and internal transcribed spacer (ITS), were utilized to examine the existence of Zanclea species from 14 Acropora species and 4 other Acroporidae genera including 142 coral samples collected from reefs in Kenting and the Penghu Islands, Taiwan, Togian Island, Indonesia, and Osprey Reef and Orpheus Island on the Great Barrier Reef, Australia. Molecular phylogenetic analyses of the 16S and 28S genes showed that Acropora-associated Zanclea was monophyletic, but the genus Zanclea was not. Analysis of the ITS, and 16S and 28S genes showed either identical or extremely low genetic diversity (with mean pairwise distances of 0.009 and 0.006 base substitutions per site for the 16S and 28S genes, respectively) among Zanclea spp. collected from diverse Acropora hosts in different geographic locations, suggesting that a cosmopolitan and probably genus-specific association occurs between Zanclea hydroids and their coral hosts.

Development of a recombinant tetravalent dengue virus vaccine: immunogenicity and efficacy studies in mice and monkeys.

Truncated recombinant dengue virus envelope protein subunits (80E) are efficiently expressed using the Drosophila Schneider-2 (S2) cell expression system. Binding of conformationally sensitive antibodies as well as X-ray crystal structural studies indicate that the recombinant 80E subunits are properly folded native-like proteins. Combining the 80E subunits from each of the four dengue serotypes with ISCOMATRIX adjuvant, an adjuvant selected from a set of adjuvants tested for maximal and long lasting immune responses, results in high titer virus neutralizing antibody responses. Immunization of mice with a mixture of all four 80E subunits and ISCOMATRIX adjuvant resulted in potent virus neutralizing antibody responses to each of the four serotypes. The responses to the components of the tetravalent mixture were equivalent to the responses to each of the subunits administered individually. In an effort to evaluate the potential protective efficacy of the Drosophila expressed 80E, the dengue serotype 2 (DEN2-80E) subunit was tested in both the mouse and monkey challenge models. In both models protection against viral challenge was achieved with low doses of antigen in the vaccine formulation. In non-human primates, low doses of the tetravalent formulation induced good virus neutralizing antibody titers to all four serotypes and protection against challenge with the two dengue virus serotypes tested. In contrast to previous reports, where subunit vaccine candidates have generally failed to induce potent, protective responses, native-like soluble 80E proteins expressed in the Drosophila S2 cells and administered with appropriate adjuvants are highly immunogenic and capable of eliciting protective responses in both mice and monkeys. These results support the development of a dengue virus tetravalent vaccine based on the four 80E subunits produced in the Drosophila S2 cell expression system.

Preparation and immunogenic properties of a recombinant West Nile subunit vaccine.

While several West Nile vaccines are being developed, none are yet available for humans. In this study aimed at developing a vaccine for humans, West Nile virus (WNV) envelope protein (E) and non-structural protein 1 (NS1) were produced in the Drosophila S2 cell expression system. The C-terminal 20% of the E protein, which contains the membrane anchor portion, was deleted, thus allowing for efficient secretion of the truncated protein (80E) into the cell culture medium. The proteins were purified by immunoaffinity chromatography (IAC) using monoclonal antibodies that were flavivirus envelope protein group specific (for the 80E) or flavivirus NS1 group specific (for NS1). The purified proteins were produced in high yield and used in conjunction with adjuvant formulations to vaccinate mice. The mice were tested for both humoral and cellular immune responses by a plaque reduction neutralization test and ELISA, and by lymphocyte proliferation and cytokine production assays, respectively. The results revealed that the 80E and the NS1 proteins induced both high-titered ELISA and neutralizing antibodies in mice. Splenocytes from immunized mice, cultured in vitro with the vaccine antigens as stimulants, showed excellent proliferation and production of cytokines (IFN-gamma, IL-4, IL-5, and IL-10). The level of antigen-stimulated lymphocyte proliferation and cytokine production was comparable to the level obtained from mitogen (phytohemagglutinin or pokeweed) stimulation, indicating a robust cellular response as well. These findings are encouraging and warrant further in vivo studies to determine the protective efficacy of the WNV vaccine candidate.