Chestnut pellicle for the recovery of gold

Recovery of Au(III) from hydrochloric acid medium by using crosslinked chestnut pellicle (CCP) gel was studied. Strong selectivity was observed for Au(III) showing negligible affinity for other precious metals and some base metal ions tested. The adsorption isotherm study exhibited the maximum loading capacity of the gel as high as 10.6 mol or about 2.1 kg gold per kg dry weight of gel. The reduction of Au(III) ion to elemental form during adsorption process is expected to be the reason of high selectivity and high capacity for Au(III). Kinetic studies at various temperatures confirm an endothermic adsorption process following the pseudo-first order rate law.     

Identification of a novel gene <Emphasis Type="Italic">ef7</Emphasis> conferring an extremely long basic vegetative growth phase in rice

A late heading-time mutant line, HS276, which was induced by gamma-irradiation of seeds of the japonica rice (Oryza sativa L.) variety Gimbozu, exhibits an extremely long basic vegetative growth phase (BVP). A genetic analysis using the F₂ population from the cross between HS276 and Gimbozu revealed that the late heading of HS276 is governed by a single recessive mutant gene. The subsequent analysis on heading responses of HS276 and Gimbozu to four photoperiods (12, 13, 14, and 15 h) and to the photoperiodic transfer treatment from a short photoperiod to a long photoperiod revealed that the mutant gene confers an extremely long BVP and increases photoperiod sensitivity under long photoperiod (14 and 15 h). The BVP durations of HS276 and Gimbozu were estimated at 30.1 and 16.0 days, respectively; the mutant gene, compared with its wild type allele, elongates the duration of BVP by 14 days. Linkage analysis showed that the mutant gene is located in the 129 kb region between the two INDEL markers, INDELAP0399_6 and INDELAP3487_2, on the distal part of the short arm of chromosome 6. None of the other BVP genes are located in this region; therefore, we declared this a newly detected mutant gene and designated it ef7. A recently established program to breed rice suitable for low latitudes, where short photoperiodic conditions continue throughout the year, aims to develop varieties with extremely long BVPs and weak photoperiod sensitivities; the mutant gene ef7, therefore, will be quite useful in these programs because it confers an extremely long BVP and little enhances photoperiod sensitivity under short photoperiod.     

Vrn-D4 is a vernalization gene located on the centromeric region of chromosome 5D in hexaploid wheat

Natural variation in wheat requirement of long exposures to cold temperatures to accelerate flowering (vernalization) is mainly controlled by the Vrn-1, Vrn-2, Vrn-3, and Vrn-4 loci. The first three loci have been well characterized, but limited information is available for Vrn-4. So far, natural variation for Vrn-4 has been detected only in the D genome (Vrn-D4), and genetic stocks for this gene are available in Triple Dirk (TDF, hereafter). We detected heterogeneity in the Vrn-1 alleles present in different TDF stocks, which may explain inconsistencies among previous studies. A correct TDF seed stock from Japan carrying recessive vrn-A1, vrn-B1, and vrn-D1 alleles was crossed with three different winter cultivars to generate F₂ mapping populations. Most of the variation in flowering time in these three populations was controlled by a single locus, Vrn-D4, which was mapped within a 1.8 cM interval flanked by markers Xcfd78 and Xbarc205 in the centromeric region of chromosome 5D. A factorial ANOVA for heading time using Vrn-D4 alleles and vernalization as factors showed a significant interaction (P < 0.0001), which confirmed that the Vrn-D4 effect on flowering time is modulated by vernalization. Comparison of the different Triple Dirk stocks revealed that Vrn-B1, Vrn-D1, and Vrn-D4 all have a small residual response to vernalization, but Vrn-D4 differs from the other two in its response to short vernalization periods. The precise mapping and characterization of Vrn-D4 presented here represent a first step toward the positional cloning of this gene.     

A new dicyemid from Benthoctopus sibiricus (Mollusca: Cephalopoda: Octopoda)

A new species of dicyemid mesozoan is described from Benthoctopus sibiricus Loyning, 1930, collected in the eastern Chukchi Sea. Dicyemennea chukchiense n. sp. is a medium species that reaches about 2,000 μm in length; it lives in folds of the renal appendages. The vermiform stages are characterized in having 23 peripheral cells, a conical calotte, and an axial cell that extends to the base of the propolar cells. An anterior abortive axial cell is present in vermiform embryos. Infusoriform embryos consist of 37 cells; a single nucleus is present in each urn cell and the refringent bodies are solid. This is the first dicyemid described from the Arctic waters.     

In situ expression of 15 kDa interferon alpha responsive gene in the developing tooth germ of the mouse lower first molar

We previously performed cDNA subtraction between the mouse mandibles at embryonic day 10.5 (E10.5) and E12.0 to make a profile of the regulator genes for odontogenesis. Fifteen kDa interferon alpha responsive gene (Ifrg15) is one of several highly-expressed genes in the E12.0 mandible. The current study examined the precise expression patterns of Ifrg15 mRNA in the mouse mandibular first molar by in situ hybridization to evaluate the possible functional roles of this gene in odontogenesis. Ifrg15 mRNA was expressed in the epithelial and mesenchymal tissues of the mandible at E10.5 and E12.0. The Ifrg15 in situ signal was detected in the epithelial bud and the surrounding mesenchyme at E14.0, and was present in the enamel organ including the primary enamel knot, and in the underlying mesenchyme at E15.0. The in situ signal was restricted in the inner and outer enamel epithelia and the stratum intermedium at E16.0. The signal of Ifrg15 mRNA was further restricted to the inner enamel epithelium and the adjacent stratum intermedium at E17.0 and E18.0. Consequently, the expression of Ifrg15 mRNA was localized in the ameloblasts and odontoblasts at postnatal days 1.0 to 3.0. However, the in situ signal was markedly weaker than at the embryonic period. The expression of Ifrg15 mRNA was coincidently observed in various craniofacial organs as well as in the tooth germ. These results suggest that Ifrg15 is closely related to odontogenesis, especially the differentiation of the ameloblasts and odontoblasts, and to the morphogenesis of the craniofacial organs.     

Halocynthiaxanthin and fucoxanthinol isolated from Halocynthia roretzi induce apoptosis in human leukemia, breast and colon cancer cells

The sea squirt Halocynthia roretzi metabolizes fucoxanthin, and subsequently accumulates its derived carotenoids with characteristic structures. In the present study, we isolated halocynthiaxanthin and fucoxanthinol as carotenoids having antiproliferative activity from H. roretzi. Halocynthiaxanthin and fucoxanthinol inhibited the growth of HL-60 human leukemia cells in a dose- and time-dependent manner. Viability of HL-60 treated with 12.5 microM halocynthiaxanthin and fucoxanthinol was decreased by 12.1% and 5.7% of control after 48 h incubation, respectively. Furthermore, halocynthiaxanthin and fucoxanthinol induced apoptosis in HL-60 cells, MCF-7 human breast cancer cells, and Caco-2 human colon cancer cells. When HL-60 cells were incubated with 12.5 microM halocynthiaxanthin and fucoxanthinol for 48 h, relative DNA fragmentations were enhanced to 5- and 7-fold compared to that in control cells, respectively. The activities of apoptosis induction by halocynthiaxanthin and fucoxanthinol were higher than that of fucoxanthin which we have previously reported as a carotenoid possessing the ability to induce apoptosis. Fucoxanthinol exhibited the highest apoptosis-inducing activity among the three carotenoids. Furthermore, the expression levels of apoptosis-suppressing protein Bcl-2 were decreased in HL-60 cells treated with halocynthiaxanthin and fucoxanthinol. These results suggest that halocynthiaxanthin and fucoxanthinol exhibited potential antiproliferative effects via apoptosis induction in several cancer cell lines.     

Selective inhibition of bleomycin-induced G2 cell cycle checkpoint by simaomicin alpha

Human T-cell leukemia-derived Jurkat cells are known to be defective in the G1 checkpoint. DNA-damaging agent bleomycin arrests the cell cycle at G2 phase of Jurkat cells, and microtubule-acting colchicine arrests it at the M phase. Simaomicin alpha, an actinomycete metabolite, itself showed no effect on the cell cycle status of Jurkat cells at least up to 6.0 nM. However, the compound (0.6-6.0 nM) was found to abrogate the bleomycin-induced G2 arrest, yielding a drastic decrease in cells at the G2 phase and increase in cells at the subG1 and G1 phases. On the other hand, the compound did not show any effect on the colchicine-induced M phase arrest in Jurkat cells. Furthermore, the compound showed almost no effect on the cell cycle status of the bleomycin-treated or -untreated normal cell line HUVEC. These data suggested that simaomicin alpha disrupts the cell cycle G2 checkpoint of cancer cells selectively, leading to sensitization of cancer cells to anti-cancer reagents.     

Removal of Mn(II) ions from aqueous neutral media by manganese-oxidizing fungus in the presence of carbon fiber

A manganese-oxidizing fungus was isolated from a hot spring in Japan. The fungus was increasingly effective at oxidizing Mn(II) ions as the concentration of organic carbon sources in the growth medium was decreased. The fungus oxidized 50 ppm of Mn(II) ions within 160 h in a pH 7.3 medium at 25 degrees C. The presence of carbon fiber shortened the time to 80 h, and promoted steady oxidation. The oxidation products were identified by XPS and XRD to be poorly crystallized and amorphous MnO(2), both with and without the fiber. These results suggest that the fiber participates in kinetically limited oxidation. The fungus was entangled with and clung to the fibers, and the oxidized Mn species accumulated on the fungus. Similarly shaped polyethylene telephthalate fiber did not enhance the oxidation, nor was adhesion of the fungus observed. Although the mechanism is still unknown, the present work shows that removal of Mn from solution through the precipitation and accumulation of Mn-oxides on the fungus in the presence of carbon fiber is a promising improvement for water treatment.     

Normovolemic hemodilution with Hb vesicle solution attenuates hypoxia in ischemic hamster flap tissue

The aim of this study was to test whether oxygenation in acutely ischemic, collateralized tissue may be improved by normovolemic hemodilution with a solution containing liposome-encapsulated human Hb (HbV). A skin flap model in anesthetized hamsters was used, which consisted of two parts receiving either anatomic or collateral perfusion. Microhemodynamics were investigated with intravital microscopy. Partial tissue oxygen tension was measured with a Clark-type microprobe. Hemodilution was obtained by exchanging 50% of the total blood volume with HbV suspended in 8% human serum albumin (HSA8) or 6% Dextran 70 (Dx70). The size of the vesicles was 276 nm, the P(50) was 22 mmHg, and the Hb concentration of the solutions was 7.5 g/dl. Colloid osmotic pressure and viscosity were 49.9 mmHg and 8.7 cP for HbV-Dx70 and 40.0 mmHg and 2.9 cP for HbV-HSA8, respectively. Hemodilution with HbV-Dx70 led to an increase in microvascular blood flow in the ischemic microvessels to maximally 158% (median, P < 0.01), whereas blood flow remained virtually unchanged after hemodilution with HbV-HSA8. In the ischemic tissue, oxygen tension was improved from 11.9 to 17.0 mmHg (P < 0.01) after hemodilution with HbV-Dx70 but remained virtually unchanged after hemodilution with HbV-HSA8. Our study suggests that the oxygenation in acutely ischemic, collateralized tissue may be improved by normovolemic hemodilution with HbV suspended in Dx70. The effect was achieved by an increase in microcirculatory blood flow related to the rheological properties of the suspending medium.