A Spontaneous Oligodendroglioma in the Lumbar Portion of the Spinal Cord in a Young BrlHan:WIST@Jcl (GALAS) Rat

Oligodendroglioma is a rare tumor originating from oligodendrocytes found mainly in the cerebrum in aged rats. Only a few reports have shown spontaneous occurrence of this tumor in the spinal cord, and no report has mentioned its occurrence in young rats. We encountered a case of spontaneous oligodendroglioma in the lumbar portion of the spinal cord in a young (9 weeks old) female BrlHan:WIST@Jcl (GALAS) rat. Here we report the detailed histopathological and immunohistochemical characteristics of this case. No clinical signs, no gross lesions at necropsy, and no specific changes in hematology or blood biochemistry were observed. The tumor was located in the dorsal funiculus in the lumbar portion of the spinal cord and widely spread to the dorsal root nerve. The neoplastic cells showed a sheet-like growth pattern and had small round nuclei, clear cytoplasm and distinct cell borders that resulted in a honeycomb pattern. No mitotic figures or other histological lesions were observed. The neoplastic cells were positively stained for Olig2 and PCNA. The present case was considered to be a low-grade oligodendroglioma based on the histological and immunohistochemical features. To our knowledge, our case is considered to be extremely rare and the first report in a young rat.     

Mica polytypes: systematic description and identification

X-ray studies of mica specimens from a variety of geological localities show that biotite and certain lithium-rich mica samples are composed of a mixture of different polytypes. Many of the biotite structures are new complex polytypes not before reported. A new method of designating mica polytypes is proposed. Techniques are described for the systematic generation of all the possible layer-stacking sequences of mica polytypes and for the verification of the stacking sequences in newly discovered forms.     

Chemical studies on antioxidant mechanism of curcuminoid: analysis of radical reaction products from curcumin

In the course of studies on the antioxidant mechanism of curcumin, its radical reaction was investigated. Curcumin was reacted with radical species, which were generated from the pyrolysis of 2, 2'-azobis(isobutyronitrile) under an oxygen atmosphere, and the reaction products from curcumin were followed by HPLC. The reaction at 70 degrees C gave several products, three of which were structurally identified to be vanillin, ferulic acid, and a dimer of curcumin after their isolation. The dimer was a newly identified compound bearing a dihydrofuran moiety, and its chemical structure was elucidated using spectroscopic analyses, especially 2D NMR techniques. A mechanism for the dimer production is proposed and its relation to curcumin's antioxidant activity discussed. The time course and gel permeation chromatography studies of the reaction were also investigated, and the results indicate that the dimer is a radical-terminated product in the initial stage.     

Simple detection method of powerful antiradical compounds in the raw extract of plants and its application for the identification of antiradical plant constituents

A simple detection method for a powerful radical scavenging compound in a mixture containing a large variety of compounds, such as the raw extract of edible plants, was developed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) as the radical reagent. The method was established on the basis of the features of the typical chain-breaking antioxidation reaction mechanism, which suggests that the radical scavenging antioxidant should be converted to other stable nonradical compounds during the reaction. This method requires only a simple HPLC instrument, and the disappearance or decrease in the peak intensity, which is induced by the addition of DPPH. This change is monitored by the HPLC to detect the powerful radical scavenger from the complex mixture. The method was applied to the detection and identification of the most powerful antiradical compound in the extracts of three antioxidatively active plant extracts (Psidium guajava, Citrus depressa, and Hypericum chinense). The radical scavenging efficiency of a newly identified compound from H. chinense was also compared with that of Trolox and catechin using the method.     

Novel nitric oxide and superoxide generation inhibitors, persenone A and B, from avocado fruit

One known, (2R)-(12Z,15Z)-2-hydroxy-4-oxoheneicosa-12,15-dien+ ++-1-yl acetate (1), and two novel compounds, persenone A (2) and B (3), have been isolated from avocado fruit (Persea americana P. Mill), as inhibitors of superoxide (O(2)(-)) and nitric oxide (NO) generation in cell culture systems. They showed marked inhibitory activities toward NO generation induced by lipopolysaccharide in combination with interferon-gamma in mouse macrophage RAW 264.7 cells. Their inhibitory potencies of NO generation (1, IC(50) = 3.6; 2, IC(50) = 1.2; and 3, IC(50) = 3.5 microM) were comparable to or higher than that of a natural NO generation inhibitor, docosahexaenoic acid (DHA; IC(50) = 4.3 microM). Furthermore, compounds 1-3 and DHA markedly suppressed tumor promoter 12-O-tetradecanoylphorbol-13-acetate-induced O(2)(-) generation in differentiated human promyelocytic HL-60 cells (1, IC(50) = 33.7; 2, IC(50) = 1.4; 3, IC(50) = 1.8; and DHA, IC(50) = 10.3 microM). It is notable that they were found to be suppressors of both NO- and O(2)(-)-generating biochemical pathways but not to be radical scavengers. The results indicate that these compounds are unique antioxidants, preferentially suppressing radical generation, and thus may be promising as effective chemopreventive agent candidates in inflammation-associated carcinogenesis.     

Mapping a factor controlling the thermostability of seed lipoxygenase-1 in barley

Barley lipoxygenase (LOX)‐1 is believed to affect the stability of flavour and the foam of beer. The purpose of this study was to investigate the genetic variation of the LOX‐1 thermostability, and to analyse the mode of inheritance of this trait. A simple method was established to evaluate the LOX‐1 relative thermostability (LOX‐RTS). With this method, 153 barley cultivars were screened for LOX‐RTS. The frequency of the LOX‐RTS values was distributed in a bimodal manner. Based on these values, the barley lines were categorized into two groups: an H‐type with relatively thermostable LOX‐1 and an L‐type with relatively thermolabile LOX‐1. Using a ‘Steptoe’/‘Morex’ doubled haploid population, a major quantitative trait locus (QTL) associated with LOX‐RTS was identified on chromosome 4H of barley, explaining 82% of the variance. Mapping of a CAPS marker specific for the LoxA locus revealed co‐segregation with this QTL. In this study, the existence of the thermostability types of barley seed LOX‐1 and the locus controlling the thermostability were made clearer.     

Induction of cytoplasmic male sterility in the seed progeny derived from artificially-synthesized interspecific chimera in Brassica

We produced artificial interspecific chimeras by in vitro grafting, and obtained cytoplasmic male sterile (CMS) variants in the seed progenies derived from backcrossing the chimera with one of the mother plants, B. campestris cv. Komatsuna. The induced CMS has been stably inherited by crossing it with `Komatsuna', not with `Ruby Ball' cabbage. The nuclear component of CMS is complete `Komatsuna' type in morphology, chromosome number (2n = 20) and Southern blot using ribosomal 17S RNA gene as a probe. PCR analysis by using mitochondrial atpA primer showed the complete `Ruby Ball' type, suggesting nuclear-cytoplasmic exchange. However, Southern blot patterns were different among those of the CMS and both parents by using atpA. Recombination or some unknown change is supposed in the mitochondrial genome via the processes of synthesis and propagation of the chimeras.     

Net blotch resistance in wild species of Hordeum

Resistance to net blotch was evaluated in 175 Hordeum vulgare subsp. spontaneum (H. spontaneum) accessions and 149 accessions of thirteen species or subspecies of wild Hordeum. Most H. spontaneum accessions showed resistance to each of the four Pyrenophora teres f. teres (P. teres) isolates tested. However, H. spontaneum accessions showed different resistance reactions, depending upon their origin. In particular, some accessions from Afghanistan and Russia showed a high level of resistance, and accessions from Morocco were susceptible. Among the four P. teres isolates, the virulence spectra on the H. spontaneum accessions were more different between isolates from different countries than between those from the same country. Hordeum spontaneum accessions susceptible to the Canadian isolate WRS102, but resistant to the other three isolates were found in Iraq suggesting the geographical differentiation of resistance genes in H. spontaneum. All accessions of the other wild Hordeum species, especially some accessions of H. marinum subsp. gussoneanum, showed high levels of resistance. These resistance genes may be useful candidates for incorporation into cultivated barley. This revised version was published online in July 2006 with corrections to the Cover Date.     

Barley lines showing prominent high green shoot regeneration in cultures derived from immature embryos

Eighty‐four cultivars of barley (Hordeum vulgare) and 95 wild strains (82 of H. spontaneum and 13 of H. agriocrithon) were surveyed for the production of callus, callus growth, and shoot regeneration in cultures derived from immature embryos. All cultivars except for ‘Turkey 381′, induced calli from more than 90% of embryos. On the other hand, the wild lines showed a large variation in the percentage of callus induction from 0 to 100%. Among the cultivars, those with the brittle rachis genotype, bt Bt₂, on chromosome 3H, regenerated shoots with a significantly higher percentage than the cultivars with the Bt bt₂ genotype. Green shoots were produced in a higher ratio (0.84) in the cultivars than in the wild lines (0.52). Among the lines examined,‘Lenins’ regenerated shoots efficiently (90.4%) and produced the highest number of calli with green shoots per embryo (4.77) followed by ‘Golden Promise’ (3.15). Examination of callus growth and shoot regeneration from embryos at different developmental stages revealed that scutellum development affected the quantity and quality of callus and shoot regeneration.