Enhancement of nutraceutical properties of licorice callus cultures using sample pre-treatment strategy

Licorice is an herbal plant in the Leguminosae family, and its roots and rhizomes are used as sweeteners in food and confectionery products. Moreover, it has a distinct inflammatory activity. In the present study, a sample pre-treatment method to induce the deglycosylation of active metabolites in callus cultures of Glycyrrhiza inflata (GI) and Glycyrrhiza glabra (GG) was developed. The results of the method evaluation showed the biotransformation of ononin to formononetin, a rare flavonoid found in trace amounts in licorice. The magnitude of enhancement was 3- and 19-fold in the GI and GG samples, respectively. Moreover, the anti-inflammatory activity assay showed that the potency of the sample pre-treatment group was higher than that of the untreated group because it exerted an enhanced suppression of cyclo-oxygenase 2 (COX-2), interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS) gene expression. This is the first report on the anti-inflammatory activity of licorice callus, which has the potential to be utilised as a functional food for health promotion. These findings support the idea of using sample preparation to impart nutraceutical properties to plant products.     

In Vivo Electrophysiology of Peptidergic Neurons in Deep Layers of the Lumbar Spinal Cord after Optogenetic Stimulation of Hypothalamic Paraventricular Oxytocin Neurons in Rats

The spinal ejaculation generator (SEG) is located in the central gray (lamina X) of the rat lumbar spinal cord and plays a pivotal role in the ejaculatory reflex. We recently reported that SEG neurons express the oxytocin receptor and are activated by oxytocin projections from the paraventricular nucleus of hypothalamus (PVH). However, it is unknown whether the SEG responds to oxytocin in vivo. In this study, we analyzed the characteristics of the brain–spinal cord neural circuit that controls male sexual function using a newly developed in vivo electrophysiological technique. Optogenetic stimulation of the PVH of rats expressing channel rhodopsin under the oxytocin receptor promoter increased the spontaneous firing of most lamina X SEG neurons. This is the first demonstration of the in vivo electrical response from the deeper (lamina X) neurons in the spinal cord. Furthermore, we succeeded in the in vivo whole-cell recordings of lamina X neurons. In vivo whole-cell recordings may reveal the features of lamina X SEG neurons, including differences in neurotransmitters and response to stimulation. Taken together, these results suggest that in vivo electrophysiological stimulation can elucidate the neurophysiological response of a variety of spinal neurons during male sexual behavior.     

Mercury contamination in the Yatsushiro Sea, south-western Japan: spatial variations of mercury in sediment

Mercury-contaminated effluent was discharged into Minamata Bay from a chemical plant over a 20-year period until 1965 (from 1958 to 1959, effluent was discharged into Minamata River), causing Minamata disease. In an effort to characterize the extent of the contamination in the Yatsushiro Sea, the vertical and horizontal distributions of mercury in sediment were investigated. Sediment was sampled at 62 locations in the southern part of the sea from 4 to 6 March 1996. In the lower layers of the long cores of sediment, the total amount of mercury was at a relatively uniform low concentration. We interpret these low values to represent the background concentration absent of anthropogenic influence. The background value thus estimated for the Yatsushiro Sea was 0.059 +/- 0.013 mg kg(-1) (mean +/- S.D., n = 51). The highest concentration in each sample ranged from 0.086 to 3.46 mg kg(-1) (mean, 0.57 mg kg(-1)). The higher values were obtained at stations near Minamata Bay and the Minamata River (the sources of the pollution). Concentrations decreased with distance from the source. An inspection of the vertical profiles of mercury concentration in cores suggested that the deposited mercury had not been fixed in sediment but had been transported, despite 30 years having past since the last discharge of contaminated effluent. At nine stations, extractable inorganic and organic mercury concentrations were determined differentially. Inorganic mercury is the predominant species in sediment and organic mercury comprising approximately 1% of the total.     

Aerosol Particle Collection Efficiency of Holey Carbon Film-Coated TEM Grids

A simple sampling method to collect aerosol particles for transmission electron microscope (TEM) analysis was developed by R’mili and others in 2013. The method involves passing air through a holey carbon film-coated copper mesh TEM grid (holey carbon grid) and sampling particles by filtration. In this study, we proposed a modified calculation method to represent the collection efficiencies of holey carbon grids, taking into consideration the porosity of the copper mesh. We then evaluated the particle collection efficiencies of holey carbon grids both theoretically and experimentally. We tested the collection efficiency of two types of holey carbon grids, with nominal pore sizes of 1.2 and 0.6 μm, using particles of monodispersed polystyrene latex (PSL) and potassium chloride. The overall collection efficiency of each grid (E_grid) was determined by the downstream/upstream concentration ratio measured by condensation particle counters (CPCs). In addition, for PSL particles, the collection efficiency of the holey carbon film (E_film) was determined by the ratio of the number of particles on the film (counted on a scanning electron microscope) to the number of inflow particles (counted by a CPC). We compared model calculations against the experimental results obtained in this study and those reported by R’mili and others in 2013. These data showed that the calculated E_grid values were in reasonably good agreement with the experimental E_grid values. However, although the model calculation indicated that E_film ≈ E_grid, there was an inconsistency between the experimental E_film and E_grid, which requires further investigation in order to determine its cause.

Copyright 2014 American Association for Aerosol Research     

Label-Free in Situ Monitoring of the DNA Hybridization Chain Reaction by Using Sequence-Selective Minor-Groove-Binding Fluorophores

A new label-free in situ monitoring system for the hybridization chain reaction (HCR) based on DNA minor-groove-binding fluorophores [Hoechst 33258 (Hoe) or quinone cyanine-dithiazole (QCy-DT)] has been developed. Use of two unmodified hairpin oligodeoxyribonucleotides containing incomplete double-stranded AATT sequences enabled target-dependent formation of probe binding sites—that is, AATT double strand—in the HCR product, together with fluorescence enhancement of minor-groove-binding fluorophores in situ. This system allows target DNA to be detected through the fluorescence enhancement of Hoe and QCy-DT in real time and in situ. Further development of a label-free, isothermal detection system might provide a cost-effective and user-friendly method for nucleic acid detection.     

Mucin 1 Gene (MUC1) and Gastric-Cancer Susceptibility

Gastric cancer (GC) is one of the major malignant diseases worldwide, especially in Asia. It is classified into intestinal and diffuse types. While the intestinal-type GC (IGC) is almost certainly caused by Helicobacter pylori (HP) infection, its role in the diffuse-type GC (DGC) appears limited. Recently, genome-wide association studies (GWAS) on Japanese and Chinese populations identified chromosome 1q22 as a GC susceptibility locus which harbors mucin 1 gene (MUC1) encoding a cell membrane-bound mucin protein. MUC1 has been known as an oncogene with an anti-apoptotic function in cancer cells; however, in normal gastric mucosa, it is anticipated that the mucin 1 protein has a role in protecting gastric epithelial cells from a variety of external insults which cause inflammation and carcinogenesis. HP infection is the most definite insult leading to GC, and a protective function of mucin 1 protein has been suggested by studies on Muc1 knocked-out mice.     

Scavenging Elemental Sb Through Addition of NbSb2 to Mm0.9Fe3.5Co0.5Sb12 Skutterudites

Our previous work identified thermal instability of p-type skutterudite as a primary cause of degradation during thermoelectric generator operation at 650°C. Residual Sb in the microstructure was believed to be the cause of diminished thermal stability, especially above the melting point of Sb (631°C). This work investigated addition of Nb to p-type skutterudite to from NbSb₂, thus scavenging elemental Sb. The results of this work are reported, along with comprehensive thermoelectric property characterization of the p-type skutterudite?+?NbSb₂ composites.