Antitumor activity of compounds isolated from leaves of Eriobotrya japonica

In a search for possible antitumor agents from natural sources, megastigmane glycosides and polyphenolic constituents isolated from the leaves of Eriobotrya japonica (Rosaceae) were found to inhibit the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced activation of Epstein-Barr virus early antigen in Raji cells. Roseoside and procyanidin B-2 were among the active compounds found in an in vitro assay; these compounds were further assessed for antitumor activity in vivo in a two-stage carcinogenesis assay on mouse skin. Roseoside significantly delayed carcinogenesis induced by peroxynitrite (initiator) and TPA (promoter), and its potency was comparable to that of a green tea polyphenol, (-)-epigallocatechin 3-O-gallate, in the same assay.     

Antimicrobial susceptibilities of Listeria monocytogenes isolated in Japan

The antimicrobial susceptibility of 201 Listeria monocytogenes isolates from foods, environments, animals and human patients in Japan was determined. All isolates were susceptible to ampicillin, the first choice of drug for listeriosis treatment, chloramphenicol, dihydrostreptomycin, erythromycin, enrofloxacin, gentamicin, kanamycin, lincomycin, nosiheptide, salinomycin, vancomycin, and virginiamycin. A human strain was resistant to oxytetracycline. The Minimum Inhibitory Concentration (MIC) for 50% of the strains and the MIC for 90% of the strains were comparable in all the isolates. This is the first investigation to compare antibiotic resistances between isolates from foods and isolates from human patients in Japan. The result showed that most of the isolates were susceptible to antibiotics used in this study.     

Effects of photoperiod on salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relation between salsolinol (SAL)‐induced prolactin (PRL) release and photoperiod in goats. A single intravenous (i.v.) injection of SAL was given to adult female goats under short (8 h light, 16 h dark) or long (16 h light, 8 h dark) photoperiod conditions at two different ambient temperatures (20°C or 5°C), and the PRL‐releasing response to SAL was compared to that of thyrotropin‐releasing hormone (TRH) or a dopamine (DA) receptor antagonist, sulpiride. SAL, as well as TRH or sulpiride, stimulated the release of PRL promptly after each injection in both 8‐ and 16‐h daily photoperiods at 20°C (P < 0.05). The area under the response curve (AUC) of PRL for the 60‐min period after injections of saline (controls), SAL, TRH and sulpiride in the 16‐h daily photoperiod group was greater than each corresponding value in the 8‐h daily photoperiod group (P < 0.05). There were no significant differences in the AUC of PRL among the values produced after the injection of SAL, TRH and sulpiride in 16‐h daily photoperiod group; however, the values produced after the injection of TRH were smallest among the three in the 8‐h daily photoperiod group (P < 0.05). The PRL‐releasing responses to SAL, TRH and sulpiride under a short and long photoperiod condition at 5°C resembled those at 20°C. These results show that a long photoperiod highly enhances the PRL‐releasing response to SAL as well as TRH or sulpiride in either medium or low ambient temperature in goats.     

Monitoring of QoI fungicide resistance in Plasmopara viticola populations in Japan

BACKGROUND: The increasing occurrence of QoI fungicide resistance in Plasmopara viticola (Berk. & MA Curtis) Berl. & DeToni populations is becoming a serious problem in the control of grapevine downy mildew. In Japan, the existence of QoI‐fungicide‐resistant P. viticola was reported in 2009. RESULTS: The QoI fungicide resistance in P. viticola samples collected from vineyards in Japan in 2008 and 2009 was monitored. Resistant P. viticola were detected in the regions where QoI fungicides have been introduced in accordance with the pest management programme, whereas in Hokkaido vineyards, where QoI fungicides have not yet been introduced, QoI‐fungicide‐resistant P. viticola were not found. CONCLUSION: Japan comprises thousands of islands and is physically isolated from other countries by the sea. Monitoring the emergence, incidence and distribution of QoI fungicide resistance in P. viticola populations in Japan is necessary to improve pest management strategies for downy mildew disease in Japanese vineyards. Copyright © 2010 Society of Chemical Industry     

Effects of photoperiod on secretory patterns of growth hormone in adult male goats

The aim of the present study was to clarify the effect of photoperiod on secretory patterns of growth hormone (GH) in male goats. Adult male goats were kept at 20°C with an 8‐h or 16‐h light photoperiod, and secretory patterns of GH secretion were compared. In addition, plasma profiles of prolactin (PRL), insulin‐like growth factor‐I (IGF‐I) and testosterone (T) were also examined to characterize GH secretion. GH was secreted in a pulsatile manner. There was no significant difference in pulse frequency between the 8‐h and 16‐h photoperiods. However, GH pulse amplitude tended to be greater in the group with the 16‐h photoperiod (P = 0.1), and mean GH concentrations were significantly greater in the 16‐h photoperiod (P < 0.05). The GH‐releasing response to GH releasing hormone was greater in the 16‐h than 8‐h photoperiod (P < 0.05). Plasma PRL and IGF‐I levels were higher in the 16‐h than 8‐h photoperiod (P < 0.05). In contrast, plasma T levels were lower in the 16‐h photoperiod (P < 0.05). These results show that a long light photoperiod enhances the secretion of GH as well as PRL and IGF‐I, but reduces plasma T concentrations in male goats.     

High-performance liquid chromatographic analysis of anthocyanins in Japanese garden iris and its wild forms

Summary Following bud pollination of tartary buckwheat (Fagopyrum tataricum) with pollens from common buckwheat (F. esculentum), cv. Mancan, 31% of the ovaries began to grow but all turned brown and withered after 6 to 14 days. Fluorescence microscopy of the growing ovaries showed the pollen-tube entering the embryo-sac. The ovules from the growing ovaries failed to produce any embryo in the culture medium in which the immature embryos from the self-pollinated (compatible) tartary flowers were able to mature and germinate. No embryo development was observed after cross-pollination. The interspecific incompatibility is attributed to the failure of gametes to fuse.Abbreviations BAP benzylaminopurine - IAA indoleacetic acid     

QTL for spikelet number from a high-yielding rice variety, Hoshiaoba, detected in an introgression line with the genetic background of an indica rice variety, IR64

Total spikelet number per panicle (TSN) is thought to be one of the most important agronomic traits associated with grain production in rice (Oryza sativa L.). We previously reported the development of 334 introgression lines (ILs) with variations in agronomic traits in the genetic background of indica rice variety IR64. Among these, an IL derived from high-yielding rice variety Hoshiaoba showed significantly higher TSN than IR64. We therefore have conducted a quantitative trait locus (QTL) analysis for TSN in an F₂ population of IL × IR64 to ascertain the genetic basis for the high TSN of the IL. The analysis revealed the presence of a QTL for TSN on chromosome 7, where several QTLs for grain number have been previously reported. We developed a near-isogenic line (NIL) for this QTL by using DNA marker-assisted selection and characterized its effect. The NIL showed significantly higher TSN than IR64. These results suggest that the QTL and the NIL will be useful materials in breeding programs aimed at increasing TSN.     

Quantification of relative flying fish paste content in the processed seafood ago-noyaki using real-time PCR

Real-time polymerase chain reaction (PCR) analysis of the 3′-portion of the mitochondrial 16S RNA gene (rDNA) coding sequence was used to determine flying fish paste in ago-noyaki. We quantified the amount of flying fish paste in ago-noyaki samples using flying fish-specific primers (Tobi16SF3/Tobi16SR) and universal primers (Univ16SF2/Univ16SR2). Using real-time PCR of standard ago-noyaki, a standard equation was obtained (y = 1.08x − 3.20; R ² = 0.977). This equation was then used to estimate the relative flying fish paste contents of eight commercially available ago-noyaki and two similar products. These results verified that the ago-noyaki products that had already been labeled with the E-mark deserved this status.