Production of Higher-quality Plastein from a Crude Single-cell Protein

From defatted n-paraffin-assimilating yeast cells, a crude protein was obtained by alkaliextraction followed by acid-precipitation. Then the protein was treated with ether until extractable substances were removed exhaustively at this stage. However, at the next stage where the ether-treated protein had been partially hydrolyzed with pepsin, when the hydrolysate was retreated with ether, it was found that ether-extractable substances totalling 270 mg/100 g were obtainable additionally. Chromatographic investigations demonstrated that the substances included significant amounts of aliphatic and aromatic hydrocarbons, some indoles, and a ubiquinone (n = 8).

From the protein hydrolysate (substrate) after the above ether-treatment, a plastein was synthesized with Bioprase under the specific conditions. The plastein was obtained as a precipitate when the whole reaction mixture was treated with aqueous ethanol or acetone. The quantity and quality (nitrogen content) of the plastein depended on the ethanol or acetone concentration. Roughly speaking, the higher the concentration, the more the plastein quantity. The converse relation held for the quality; a plastein precipitated by treatment solely with water showed a higher quality than any other case.     

Changes in bacterial glycolipids as an index of intestinal lactobacilli and epithelial glycolipids in the digestive tracts of mice after administration of penicillin and streptomycin

The major lipid constituent of symbiotic gram-positive bacteria in animals are phosphatidylglycerol, cardiolipin and dihexaosyl diglycerides (DH-DG), whose hydrophobic structures are characteristic of the environments, and the carbohydrate structures of DH-DGs are bacterial species-characteristic. Immunization of rabbits with intestinal lactobacilli generated antibodies against DH-DGs and their modified structures, among which Galα1-6-substituted DH-DG, i.e., Lactobacillus tetrahexaosyl diglyceride (LacTetH-DG), reacted with antibodies more intensely than DH-DG. Whereas, from the 16S-rRNA sequence, the intestinal lactobacilli in murine digestive tracts were revealed to be L. johnsonii, in which LacTetH-DG is present at the concentration of 2.2 ng per 1?×?10⁶ cells. To obtain more accurate estimates of intestinal lactobacilli in several regions of the digestive tract of mice, LacTetH-DG was detected by TLC-immunostaining with anti-Lactobacillus antisera, being found in the stomach, cecum and colon of normal breeding mice, 1.0?×?10⁹, 3.5?×?10⁹ and 7.4?×?10⁹ cells, respectively. Administration of penicillin and streptomycin for 6 days resulted in a reduction in the number of intestinal lactobacilli, the levels being 0 %, 30 % and 4 % of the control ones in the stomach, cecum and colon, respectively, which was associated with the accumulation of the contents in the tracts from the stomach to the cecum and with diarrhea. In addition, a reduced amount of fucosyl GA1 (FGA1) and a compensatory increase in GA1 due to the reduced activity of α1,2-fucosyltransferase in the small intestine and the enhanced discharge of FGA1 into the contents occurred in mice, probably due to the altered population of bacteria caused by administration of penicillin and streptomycin.     

Cytokine and chemokine expression in a rat endometriosis is similar to that in human endometriosis

The pathogenesis of endometriosis, a gynecologic disorder associated with infertility, appears to involve immune responses. However, the details involved have not been clarified. In this study, we analyzed expression levels of interleukin (IL)-6, IL-10, monocyte chemoattractant protein-1, eosinophil chemotactic protein, macrophage inflammatory protein-1α, and regulated on activation normal T cell expressed and secreted (RANTES) and CC chemokine receptor 1 in endometriotic lesions in a rat model in which endometrium is autotransplanted onto peritoneal tissue and found that they were remarkably increased, while those of IL-2, IL-4, and interferon-γ were not. These results were obtained in a rat model induced by autologous, not allogeneic, transplantation of endometrial epithelium to the peritoneum. Expression of these factors is consistent with that of endometriosis in humans. Therefore, this model may be useful in the investigation of the pathogenesis and treatment of endometriosis.     

Mechanistic insights into tRNA cleavage by a contact-dependent growth inhibitor protein and translation factors

Contact-dependent growth inhibition is a mechanism of interbacterial competition mediated by delivery of the C-terminal toxin domain of CdiA protein (CdiA–CT) into neighboring bacteria. The CdiA–CT of enterohemorrhagic Escherichia coli EC869 (CdiA–CT^EC869) cleaves the 3′-acceptor regions of specific tRNAs in a reaction that requires the translation factors Tu/Ts and GTP. Here, we show that CdiA–CT^EC869 has an intrinsic ability to recognize a specific sequence in substrate tRNAs, and Tu:Ts complex promotes tRNA cleavage by CdiA–CT^EC869. Uncharged and aminoacylated tRNAs (aa-tRNAs) were cleaved by CdiA–CT^EC869 to the same extent in the presence of Tu/Ts, and the CdiA–CT^EC869:Tu:Ts:tRNA(aa-tRNA) complex formed in the presence of GTP. CdiA–CT^EC869 interacts with domain II of Tu, thereby preventing the 3′-moiety of tRNA to bind to Tu as in canonical Tu:GTP:aa-tRNA complexes. Superimposition of the Tu:GTP:aa-tRNA structure onto the CdiA–CT^EC869:Tu structure suggests that the 3′-portion of tRNA relocates into the CdiA–CT^EC869 active site, located on the opposite side to the CdiA–CT^EC869 :Tu interface, for tRNA cleavage. Thus, CdiA–CT^EC869 is recruited to Tu:GTP:Ts, and CdiA–CT:Tu:GTP:Ts recognizes substrate tRNAs and cleaves them. Tu:GTP:Ts serves as a reaction scaffold that increases the affinity of CdiA–CT^EC869 for substrate tRNAs and induces a structural change of tRNAs for efficient cleavage by CdiA–CT^EC869.     

Dimerization of DOCK2 Is Essential for DOCK2-Mediated Rac Activation and Lymphocyte Migration

The migratory properties of lymphocytes depend on DOCK2, an atypical Rac activator predominantly expressed in hematopoietic cells. Although DOCK2 does not contain the Dbl homology domain typically found in guanine nucleotide exchange factors (GEFs), DOCK2 mediates the GTP-GDP exchange reaction for Rac via its DOCK homology region (DHR)-2 (also known as CZH2 or Docker) domain. DOCK2 DHR-2 domain is composed of three lobes, and Rac binding site and catalytic center are generated entirely from lobes B and C. On the other hand, lobe A has been implicated in dimer formation, yet its physiological significance remains unknown. Here, we report that lobe A-mediated DOCK2 dimerization is crucial for Rac activation and lymphocyte migration. We found that unlike wild-type DOCK2, DOCK2 mutant lacking lobe A failed to restore motility and polarity when expressed in thymoma cells and primary T cells lacking endogenous expression of DOCK2. Similar results were obtained with the DOCK2 point mutant having a defect in dimerization. Deletion of lobe A from the DHR-2 domain did not affect Rac GEF activity in vitro. However, fluorescence resonance energy transfer analyses revealed that lobe A is required for DOCK2 to activate Rac effectively during cell migration. Our results thus indicate that DOCK2 dimerization is functionally important under the physiological condition where only limited amounts of DOCK2 and Rac are localized to the plasma membrane.     

Crossing test among floating Ulva thalli forming `green tide' in Japan

Crossing tests were made to determine the relationship between the identified Ulva pertusa, which commonly grows in Japan as an attached form on exposed rocks, and the floating Ulva forming "green tide" inside calm bays. The floating Ulva thalli were collected from five major green tide sites in Japan (Yokohama, Mikawa, Miyajima, Kochi and Hakata). Reproductive maturation was induced in U. pertusa and the floating thalli from each site. Mating between induced gametes was observed. It is therefore believed that the floating thalli from Yokohama, Mikawa and Miyajima were mainly U. pertusa, while those from Kochi and Hakata were of a different species (Ulva sp.1). Furthermore, the Ulva species found in Mikawa is also a species (Ulva sp.2) different from both U. pertusa and Ulva sp.1.     

Assessment of border control measures and community containment measures used in Japan during the early stages of Pandemic (H1N1) 2009

Background

In the early stages of Pandemic (H1N1) 2009, border control measures were taken by quarantine stations to block the entry of infected individuals into Japan and community containment measures were implemented to prevent the spreading. The objectives of this study were to describe these measures and the characteristics of infected individuals, and to assess the measures'' effectiveness.

Methodology/Principal Findings

Border control and community containment measures implemented from April to June (Period I: April 28–May 21, Period II: May 22–June 18) 2009 were described. Number of individuals identified and disease characteristics were analyzed. For entry screening, a health declaration form and an infrared thermoscanner were used to detect symptomatic passengers. Passengers indicated for the rapid influenza test underwent the test followed by RT-PCR. Patients positive for H1N1 were isolated, and close contacts were quarantined. Entry cards were handed out to all asymptomatic passengers informing them about how to contact a health center in case they developed symptoms. Nine individuals were identified by entry screening and 1 during quarantine to have Pandemic (H1N1) 2009. Health monitoring by health centers was performed in period I for passengers arriving from affected countries and in period II for those who had come into contact with the individuals identified by entry screening. Health monitoring identified 3 infected individuals among 129,546 in Period I and 5 among 746 in Period II. Enhanced surveillance, which included mandatory reporting of details of the infected individuals, identified 812 individuals, 141 (18%) of whom had a history of international travel. Twenty-four of these 141 passengers picked up by enhanced surveillance had been developing symptoms on entry and were missed at screening.

Conclusion/Significance

Symptomatic passengers were detected by the various entry screening measures put in place. Enhanced surveillance provided data for the improvement of public health measures in future pandemics.     

Development of nuclear microsatellite markers for the threatened wetland plant Geranium soboliferum var. kiusianum (Geraniaceae)

Nuclear microsatellite markers were developed for the threatened plant Geranium soboliferum var. kiusianum, which has decreased its population size as a result of loss of its wetland habitat in Kyushu, Japan. Utilizing RNA‐seq data obtained by next‐generation sequencing techniques, 10 polymorphic microsatellite markers with 3–16 alleles in a nuclear genome were developed and characterized. Two to 15 alleles were observed in G. soboliferum. These markers will be used to investigate the genetic circumstance of remnant populations of G. soboliferum var. kiusianum and their phylogenetic relationship with G. soboliferum.