Antimicrobial Activity of Antrodia camphorata Extracts against Oral Bacteria

Antrodia camphorata (A. camphorata) is a unique, endemic and extremely rare mushroom species native to Taiwan, and both crude extracts of and purified chemical compounds from A. camphorata have been reported to have a variety of significant beneficial effects, such as anti-tumor and anti-inflammatory activity. However, reports on the effects of A. camphorata against dental pathogens have been limited. Oral health is now recognized as important for overall general health, including conditions such as dental caries, periodontal disease and rheumatoid arthritis. Streptococcus mutans (S. mutans) and Porphyromonas gingivalis (P. gingivalis) are the most common bacteria associated with dental plaque and periodontopathic diseases, respectively. Thus, our study examined the ability of five various crude extracts of A. camphorata to inhibit the growth of dental bacteria and anti-adherence in vitro. Among the extracts, the ethanol, ethyl acetate and chloroform extracts exhibited the lowest MICs against P. gingivalis and S. mutans (MIC = 4∼16 µg/mL). The MIC of the aqueous extract was greater than 2048 µg/mL against both P. gingivalis and S. mutans. In vitro adherence of S. mutans was significantly inhibited by the addition of either the ethyl acetate extract or chloroform extract (MIC = 16∼24 µg/mL), while the ethanol extract (MIC = 32∼64 µg/mL) exhibited moderate inhibitory activity. Based on the result of this study, the ethyl acetate and chloroform extracts of A. camphorata may be good candidates for oral hygiene agents to control dental caries and periodontopathic conditions.     

Molecular phylogeny of the paper wasp subgenus Polistes (Polistella) Ashmead, 1904 (Hymenoptera: Vespidae: Polistinae) from Vietnam

This study provides the first molecular phylogeny of the social wasp subgenus Polistella (Hymenoptera: Vespidae: Polistes) from Vietnam. Fragments of the mitochondrial COI and 16S rRNA genes were used to reconstruct the phylogenetic trees among 38 Polistes species plus two out-group species (Vespa soror du Buysson and Ropalidia fasciata (Fabricius)). Our results support the existence of several species-groups, including two that are congruent with the previous stigma and Stenopolistes groups defined on the basis of morphology. Moreover, we recovered a clade including the stigma group and the two species P. humilis and P. variabilis that was sister to all other species of Polistella. However, the results also challenged the definition of other groups of Polistella based on morphological data, as well as the definition of two species: P. brunus and P. affinis. This first study calls for further analyses including morphological characters to clarify the taxonomy and the classification of the group.     

DETERMINATION OF PREGNANCY STATUS FROM BLUBBER SAMPLES IN MINKE WHALES (BALAENOPTERA ACUTOROSTRATA)

Measurement of progesterone concentration in blubber was developed as a method to detect pregnancy in minke whales. Progesterone was extracted and quantified from blubber samples of minke whale carcasses by radioimmunoassay. Results showed a highly significant difference (almost 60-fold) between blubber progesterone concentrations of anatomically determined pregnant females versus non-pregnant female or male carcasses. The results of the study suggest that the blubber progesterone concentrations might be used to determine pregnancy status in free-ranging whales.     

Effects of counter-ion size on solid state structures of M(Nitrilotriacetate) complexes

The crystal structure of Na[Co(NC₆H₆O₆)] · H₂O is reported. The structure is compared to similar transition-metal nitrilotriacetate complexes containing different alkali cations and transition metals (Cu²⁺ and Zn²⁺). Inner-sphere coordination of the metals is similar, but the arrangement of counter-ions and water molecules in the unit cells vary with the size of the alkali cation.     

Ameobal pathogen mimivirus infects macrophages through phagocytosis

Mimivirus, or Acanthamoeba polyphaga mimivirus (APMV), a giant double-stranded DNA virus that grows in amoeba, was identified for the first time in 2003. Entry by phagocytosis within amoeba has been suggested but not demonstrated. We demonstrate here that APMV was internalized by macrophages but not by non-phagocytic cells, leading to productive APMV replication. Clathrin- and caveolin-mediated endocytosis pathways, as well as degradative endosome-mediated endocytosis, were not used by APMV to invade macrophages. Ultrastructural analysis showed that protrusions were formed around the entering virus, suggesting that macropinocytosis or phagocytosis was involved in APMV entry. Reorganization of the actin cytoskeleton and activation of phosphatidylinositol 3-kinases were required for APMV entry. Blocking macropinocytosis and the lack of APMV colocalization with rabankyrin-5 showed that macropinocytosis was not involved in viral entry. Overexpression of a dominant-negative form of dynamin-II, a regulator of phagocytosis, inhibited APMV entry. Altogether, our data demonstrated that APMV enters macrophages through phagocytosis, a new pathway for virus entry in cells. This reinforces the paradigm that intra-amoebal pathogens have the potential to infect macrophages.     

Comparable length at weaning in cetaceans

Weaning represents the transition of mammalian life from maternal dependence to independence in both energetics and behavior. The length at weaning (Lw) is determined by the maternal investment during gestation and lactation. It affects calf survival and impacts on the long‐term persistence of species, but the measurement is not readily obtainable for many cetaceans. A general linear model and residual correlation were used to explore the correlations between the published Lw and five other life history traits of cetaceans, including female asymptotic length (Lx), length at birth (Lb), lactation period (LP), gestation period (GP), and calving interval (CI). Lx was a significant confounding parameter on the other five traits. By eliminating the confounding Lx, ANCOVA revealed that baleen whales (Mysticeti) and toothed cetaceans (Odontoceti) had comparable Lw. By residual correlation, which factors the confounding Lx, Lw was significantly correlated with Lb but not with GP, LP, and CI. After Lb was further eliminated, convergent Lw in cetaceans could still be observed. Therefore, we proposed a generic expression Lw= 1.239Lx^0.877, which allows us to further estimate Lw of undocumented cetacean species.