Conjugation of both on-axis and off-axis light in Nipkow disk confocal microscope to increase availability of incoherent light source

Laser-scanning confocal microscopy has been employed for exploring structures at subcellular, cellular and tissue level in three dimensions. To acquire the confocal image, a coherent light source, such as laser, is generally required in conventional single-point scanning microscopy. The illuminating beam must be focused onto a small spot with diffraction-limited size, and this determines the spatial resolution of the microscopy system. In contrast, multipoint scanning confocal microscopy using a Nipkow disk enables the use of an incoherent light source. We previously demonstrated successful application of a 100 W mercury arc lamp as a light source for the Yokogawa confocal scanner unit in which a microlens array was coupled with a Nipkow disk to focus the collimated incident light onto a pinhole (Saito et al., Cell Struct. Funct., 33: 133-141, 2008). However, transmission efficiency of incident light through the pinhole array was low because off-axis light, the major component of the incident light, was blocked by the non-aperture area of the disk. To improve transmission efficiency, we propose an optical system in which off-axis light is able to be transmitted through pinholes surrounding the pinhole located on the optical axis of the collimator lens. This optical system facilitates the use of not only the on-axis but also the off-axis light such that the available incident light is considerably improved. As a result, we apply the proposed system to high-speed confocal and multicolor imaging both with a satisfactory signal-to-noise ratio.     

Listerial invasion protein internalin B promotes entry into ileal Peyer's patches in vivo

Listeria monocytogenes (Lm) invades the host intestine using listerial invasion proteins, internalins. The in vivo role of internalin A (InlA) and internalin B (InlB) is reported here. Intragastric (i.g.) administration and ligated loop assays with ΔinlB-Lm demonstrated that a lack of InlB significantly attenuates the invasive ability of Lm into various organs. On the other hand, InlA(m)-Lm expressing a mutant InlA with two substitutions, S192N and Y369S, which has been reported to increase the affinity of InlA to mouse E-cadherin, resulted in little increase in intestinal infection according to both ligated loop and i.g. infection assays. Lm preferentially enters ileal Peyer's patch (PP) via M cells and ΔinlB-Lm showed severely reduced ability to invade though these cells. The present results reveal the importance of InlB, which accelerates listerial invasion into M cells on ileal PPs in vivo.     

Localization of plasminogen in mouse hippocampus,cerebral cortex,and hypothalamus

Although the tissue plasminogen activator/plasminogen system contributes to numerous brain functions, such as learning, memory, and anxiety behavior, little attention has as yet been given to the localization of plasminogen in the brain. We have investigated the localization of plasminogen in the adult mouse brain by using immunohistochemistry. In the hippocampus, plasminogen immunoreactivity was seen in the pyramidal cell layer as numerous punctate structures in neuronal somata. An electron-microscopic study further demonstrated that the plasminogen-immunoreactive punctate structures represented secretory vesicles and/or vesicle clusters. In the cerebral cortex, plasminogen immunoreactivity was evident in the somata of the layer II/III and V neurons. A quantitative analysis revealed that parvalbumin (PV)-positive neurons had more plasminogen-immunoreactive puncta compared with those of PV-negative neurons in the hippocampus and cerebral cortex. Plasminogen immunoreactivity was present throughout the hypothalamus, being particularly prominent in the neuronal somata of the organum vasculosum laminae terminalis, ventromedial preoptic nucleus, supraoptic nucleus, subfornical organ, medial part of the paraventricular nucleus (PVN), posterior part of the PVN, and arcuate hypothalamic nucleus. Thus, plasminogen is highly expressed in specific populations of hippocampal, cortical, and hypothalamic neurons, and plasminogen-containing vesicles are mainly observed at neuronal somata.     

Novel 12-membered non-antibiotic macrolides from erythromycin A; EM900 series as novel leads for anti-inflammatory and/or immunomodulatory agents

Herein, we report the design and synthesis of the novel 12-membered non-antibiotic macrolide (8R,9S)-8,9-dihydro-6,9-epoxy-8,9-anhydropseudoerythromycin A (EM900), which was found to be a potent anti-inflammatory and/or immunomodulatory agent, capable of promoting monocyte to macrophage differentiation. This molecule shows improved acid stability, does not exhibit any anti-bacterial activity and has relatively low cytotoxicity against THP-1 cells. In addition, one of its analogues, (8R,9S)-4″,13-O-diacetyl-8,9-dihydro-6,9-epoxy-8,9-anhydropseudoerythromycin A (EM911), was found to be twice as effective as EM900.     

Activin/TGF-beta signaling regulates Nanog expression in the epiblast during gastrulation

Nanog is required for the maintenance of cellular pluripotency during normal development and in cultured embryonic stem cells. A number of signaling pathways have been implicated in regulating Nanog gene expression in vitro. Using the chick model, we provide in vivo evidence for the involvement of the Activin/TGF-beta signaling pathway in regulating Nanog expression in epiblast cells during gastrulation. Nanog expression in primordial germ cells is not regulated by this pathway, indicating that these two cell types employ different mechanisms for maintaining pluripotency in early development. Furthermore, our data suggest that the bHLH factor E2A plays a role in negatively regulating Nanog expression in vivo. Overall, our data support a direct and positive role of the Smad2/3 mediated TGF-beta signaling pathway in inducing/maintaining Nanog expression.     

Amoebal Endosymbiont Neochlamydia Genome Sequence Illuminates the Bacterial Role in the Defense of the Host Amoebae against Legionella pneumophila

Previous work has shown that the obligate intracellular amoebal endosymbiont Neochlamydia S13, an environmental chlamydia strain, has an amoebal infection rate of 100%, but does not cause amoebal lysis and lacks transferability to other host amoebae. The underlying mechanism for these observations remains unknown. In this study, we found that the host amoeba could completely evade Legionella infection. The draft genome sequence of Neochlamydia S13 revealed several defects in essential metabolic pathways, as well as unique molecules with leucine-rich repeats (LRRs) and ankyrin domains, responsible for protein-protein interaction. Neochlamydia S13 lacked an intact tricarboxylic acid cycle and had an incomplete respiratory chain. ADP/ATP translocases, ATP-binding cassette transporters, and secretion systems (types II and III) were well conserved, but no type IV secretion system was found. The number of outer membrane proteins (OmcB, PomS, 76-kDa protein, and OmpW) was limited. Interestingly, genes predicting unique proteins with LRRs (30 genes) or ankyrin domains (one gene) were identified. Furthermore, 33 transposases were found, possibly explaining the drastic genome modification. Taken together, the genomic features of Neochlamydia S13 explain the intimate interaction with the host amoeba to compensate for bacterial metabolic defects, and illuminate the role of the endosymbiont in the defense of the host amoebae against Legionella infection.     

Periodontitis in Cardiovascular Disease Patients with or without Marfan Syndrome -A Possible Role of Prevotella intermedia-

Background

Although periodontitis is a risk factor for cardiovascular disease (CVD), the influence of periodontitis on Marfan syndrome (MFS) with CVD is unclear. The aim of this study was to assess the relationship between periodontal bacterial burden and MSF with CVD.

Methods and Results

The subjects were patients with MFS with CVD (n = 47); age and gender matched non-MFS CVD patients (n = 48) were employed as controls. Full-mouth clinical measurements, including number of teeth, probing of pocket depth (PD), bleeding on probing (BOP) and community periodontal index (CPI) were recorded. We also evaluated the existence of three periodontal pathogens, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Prevotella intermedia using polymerase chain reaction assays. Serum antibody titers against the pathogens were also measured. We revealed that MFS with CVD patients had periodontitis more frequently than the age and gender matched non-MFS CVD control subjects. MFS with CVD patients had significantly severer periodontitis, fewer remaining teeth and deeper PD compared to the non-MFS CVD controls. Furthermore, the serum antibody titer level against Prevotella intermedia was significantly lower in MFS plus CVD patients compared to the non-MFS CVD patients.

Conclusion

Periodontitis may influence the pathophysiology of cardiovascular complications in MFS patients. A specific periodontal pathogen might be a crucial therapeutic target to prevent CVD development.     

Synthesis and insecticidal activity of novel dihydropyrrole derivatives with N-sulfanyl,sulfinyl, and sulfonyl moieties

This paper reports the synthesis and insecticidal activity of a new type of dihydropyrrole derivatives with sulfur moieties such as sulfanyl, sulfinyl, and sulfonyl groups at the 1-position. These derivatives exhibited high insecticidal potency against Nilaparvata lugens and Nephotettix cincticeps. Investigation of the structure-activity relationships revealed that the alkoxycarbonyloxy groups at the 4-position tended to increase the systemic insecticidal activity.