Screening of Australian Native Grasses for Rhizoremediation of Aliphatic Hydrocarbon-Contaminated Soil

Rhizoremediation involves the breakdown of contaminants in soil resulting from microbial activity that is enhanced in the plant root zone. The objective of this study was to identify Australian native grass species as suitable candidates for rhizoremediation application. Seeds of nine perennial Australian native grasses were sown in soil from a mine site and artificially contaminated with a 60:40 diesel/oil mixture at concentrations of 1% (w/w), 0.5% (w/w), and 0% (control). Seedling emergence was not adversely affected by the presence of hydrocarbon contamination for all but one grass species. Three promising species (Brachiaria decumbens, Cymbopogon ambiguus, and Microlaena stipoides var. Griffin) were assessed for growth characterization in contaminated and uncontaminated soils. The evaluated species survived for 120 days in the contaminated soil and, in some instances, produced considerably more root biomass in the presence of contamination. C. ambiguus showed growth stimulation in the presence of contamination (1% and 0.5% w/w) with significantly increased root biomass production compared with the control (p = 0.0001). B. decumbens and M. stipoides showed tolerance, without adverse growth effects in the presence of diesel/oil at the exposed concentrations. Stimulation of the rhizosphere microbial population that is capable of degrading diesel/oil was found for all of the species tested, using a most probable number method for enumeration. This investigation has identified suitable candidates for further investigation of their rhizoremediation potential.     

Toward the synthesis of fine chemicals from lactose: preparation of d-xylo and l-lyxo-aldohexos-5-ulose derivatives

The transformation of (5R)-2,6-di-O-benzyl-5-C-methoxy-β-d-galactopyranosyl-(1→4)-2,3:5,6-di-O-isopropylidene-aldehydo-d-glucose dimethyl acetal (8) into partially protected derivatives of d-xylo- and l-lyxo-aldohexos-5-ulose has been reported, applying appropriate epimerisation methods to its 3′-O- and 4′-O-protected alcoholic derivatives.     

Evidence that TGFA influences risk to cleft lip with/without cleft palate through unconventional genetic mechanisms

This study examined the association between markers in transforming growth factor alpha (TGFA) and isolated, non-syndromic cleft lip with/without palate (CL/P) using a case–parent trio design, considering parent-of-origin effects. We also tested for gene–environmental interaction with common maternal exposures, and for gene–gene interaction using markers in TGFA and another recognized causal gene, IRF6. CL/P case–parent trios from four populations (76 from Maryland, 146 from Taiwan, 35 from Singapore, and 40 from Korea) were genotyped for 17 single nucleotide polymorphisms (SNPs) in TGFA. The transmission disequilibrium test was used to test individual SNPs, and the parent-of-origin likelihood ratio test (PO-LRT) was used to assess parent-of-origin effects. We also screened for possible gene–environment interaction using PBAT, and tested for gene–gene interaction using conditional logistic regression models. When all trios were combined, four SNPs showed significant excess maternal transmission, two of which gave significant PO-LRT values [rs3821261: P = 0.004 and OR(imprinting) = 4.17; and rs3771475: P = 0.027 and OR(imprinting) = 2.44]. Haplotype analysis of these two SNPS also supported excess maternal transmission. We saw intriguing but suggestive evidence of G × E interaction for several SNPs in TGFA when either individual SNPs or haplotypes of adjacent SNPs were considered. Thus, TGFA appears to influence risk of CL/P through unconventional means with an apparent parent-of-origin effect (excess maternal transmission) and possible interaction with maternal exposures.     

E4orf1 Limits the Oncolytic Potential of the E1B-55K Deletion Mutant Adenovirus

Clinical trials have shown oncolytic adenoviruses to be tumor selective with minimal toxicity toward normal tissue. The virus ONYX-015, in which the gene encoding the early region 1B 55-kDa (E1B-55K) protein is deleted, has been most effective when used in combination with either chemotherapy or radiation therapy. Therefore, improving the oncolytic nature of tumor-selective adenoviruses remains an important objective for improving this form of cancer therapy. Cells infected during the G₁ phase of the cell cycle with the E1B-55K deletion mutant virus exhibit a reduced rate of viral late protein synthesis, produce fewer viral progeny, and are less efficiently killed than cells infected during the S phase. Here we demonstrate that the G₁ restriction imposed on the E1B-55K deletion mutant virus is due to the viral oncogene encoded by open reading frame 1 of early region 4 (E4orf1). E4orf1 has been reported to signal through the phosphatidylinositol 3′-kinase pathway leading to the activation of Akt, mTOR, and p70 S6K. Evidence presented here shows that E4orf1 may also induce the phosphorylation of Akt and p70 S6K in a manner that depends on Rac1 and its guanine nucleotide exchange factor Tiam1. Accordingly, agents that have been reported to disrupt the Tiam1-Rac1 interaction or to prevent phosphorylation of the ribosomal S6 kinase partially alleviated the E4orf1 restriction to late viral protein synthesis and enhanced tumor cell killing by the E1B-55K mutant virus. These results demonstrate that E4orf1 limits the oncolytic nature of a conditionally replicating adenovirus such as ONYX-015. The therapeutic value of similar oncolytic adenoviruses may be improved by abrogating E4orf1 function.Conditionally replicating adenoviruses are a novel class of biological agents used to treat cancer (57). The E1B-55K deletion mutant virus ONYX-015, originally known as dl1520 (4), is one of the first of such agents (7). H101 is another E1B-55K deletion mutant adenovirus that is being used for tumor therapy in China (30, 78). We previously reported that cells infected during the G₁ phase of the cell cycle with E1B-55K deletion mutant adenoviruses exhibit a reduced rate of viral late protein synthesis, produce fewer viral progeny, and are less effectively killed than cells infected during S phase (34, 35, 66). These observations indicated that the E1B-55K deletion mutant virus ONYX-015 is restricted in cells infected in G₁. This restriction is significant because a large fraction of cells within a tumor exist in the G₁ phase of the cell cycle (71). Here we show that the G₁ restriction imposed on the E1B-55K deletion mutant virus is due to the viral oncogene encoded by open reading frame 1 of early region 4 (E4orf1).The E4orf1-encoded protein is a small adapter molecule that associates with PDZ domain-containing proteins including MUPP1, PATJ, MAGI-1, ZO-2, and Dlg1 (46). PDZ domain-containing proteins often serve as scaffolds for the assembly of signaling complexes at the plasma membrane (64). Through its association with PDZ domain-containing proteins, the E4orf1-encoded protein promotes signaling through the phosphatidylinositol 3′-kinase (PI3-kinase) pathway to effectors such as protein kinase B (Akt), the mammalian target of rapamycin (mTOR), and the S6 ribosomal protein kinase (p70 S6K) (27, 54). Through these effectors, PI3-kinase alters protein synthesis and cell survival (21, 28). E4orf1 is the principal oncogenic determinant of species D adenovirus type 9 (42). The transforming ability of E4orf1 can be blocked by the PI3-kinase inhibitor {"type":"entrez-nucleotide","attrs":{"text":"LY249002","term_id":"1257710161","term_text":"LY249002"}}LY249002 (27). However, phosphorylation of p70 S6K can also proceed by pathways that are independent of PI3-kinase or Akt. For example, the Rho-like GTPase Rac1 can activate p70 S6K (17). Rac1 is itself regulated by cellular factors to which it binds, including the Rac1-specific guanine nucleotide exchange factor T-cell lymphoma invasion and metastasis 1 protein (Tiam1). Tiam1 and the neural tissue-associated F-actin-binding protein neurabin II or spinophilin recruit p70 S6K into a complex containing Rac1, resulting in increased phosphorylation of p70 S6K (12, 36, 50). Interestingly, both Tiam1 and neurabin II are PDZ-containing proteins. These observations provided a potential basis by which E4orf1 may modulate protein synthesis and cell survival.In this report, we show for the first time that E4orf1 restricts the abilities of the E1B-55K deletion mutant virus to produce viral progeny, to direct viral late protein synthesis, and to kill tumor cells. Drugs that are reported to prevent phosphorylation of p70 S6K or to disrupt the interaction between Tiam1 and Rac1 increase the cell-killing ability of the E1B-55K deletion mutant virus to nearly the same level observed for an E1B-55K/E4orf1 double mutant and the wild-type virus. By uncovering a role for E4orf1 in the course of a lytic adenovirus infection, this study presents novel genetic and pharmacological means by which the effectiveness of replicating oncolytic adenoviruses can be improved.     

Tumbleweed (Salsola, section Kali) species and speciation in California

Tumbleweeds (Salsola species, section Kali) are road side and rangeland pest plants throughout the 48 contiguous states in the US. Three described tumbleweed species and two undescribed Salsola taxa occur in California. The known species are Russian thistle, Salsola tragus, introduced from Eurasia in the 1800s, Russian barbwire thistle, S. paulsenii, which grows in the desert regions of California, and is also native to Eurasia, and the recently identified S. kali subspecies austroafricana, possibly native to South Africa. Our goals were to investigate karyology, genome size, and molecular genetic affinities of the described species and the other taxa within their ranges in California using recently developed microsatellite loci, dominant nuclear DNA markers (RAPD and ISSR), and DNA sequence data. Chromosome counts and genome size assessments made with flow cytometry were compared. These analyses indicated that one undescribed taxon is a new allopolyploid hybrid between S. tragus and S. kali subspecies austroafricana, and the other undescribed taxon appears to be a complex hybrid involving all three described species. The invasion potentials for the hybrid taxa are unknown. Tumbleweeds are the focus of biological controls efforts but the identification of suitable agents for the hybrid taxa may be problematic because of the large amount of genetic variability encompassed within this evolving Salsola complex.     

Congenital neuroglial heterotopia in a neonatal harbor seal (Phoca vitulina richardsi ) with evidence of recent exposure to polycyclic aromatic hydrocarbons

A male neonatal Pacific harbor seal (Phoca vitulina richardsi) stranded off the coast of California, USA, was presented for rehabilitation with numerous partially haired, soft tissue masses around the mouth and in the oropharynx. Because of the extent of the lesions, the seal was humanely euthanized. Histologically, the masses consisted of subepithelial connective tissue and subcutis expanded by a proliferation of streams and bundles of spindle to stellate cells. Morphology of these cells suggested a neural origin, which was confirmed by positive immunohistochemistry for two neural markers, S-100 protein and glial fibrillary acidic protein, so the masses were diagnosed as neuroglial heterotopia. Heterotopic neuroglial tissue is a rare lesion comprised of benign mature neural tissue in an ectopic location with no connection to the central nervous system. Results of polycyclic aromatic hydrocarbon (PAH) metabolite analysis of bile indicated recent exposure to a petroleum source. Although fetal exposure to PAHs in utero can cause neurotoxicity and affect normal embryonic development, it is unknown whether gestational exposure occurred in this case.     

Root cultures of <Emphasis Type="Italic">Hypericum perforatum</Emphasis> subsp. <Emphasis Type="Italic">angustifolium</Emphasis> elicited with chitosan and production of xanthone-rich extracts with antifungal activity

Hypericum perforatum is a well-known medicinal plant which contains a wide variety of metabolites, including xanthones, which have a wide range of biological properties, including antifungal activity. In the present study, we evaluated the capability of roots regenerated from calli of H. perforatum subsp. angustifolium to produce xanthones. Root biomass was positively correlated with the indole-3-butyric acid concentration, whereas a concentration of 1 mg l⁻¹ was the most suitable for the development of roots. High auxin concentrations also inhibited xanthone accumulation. Xanthones were produced in large amounts, with a very stable trend throughout the culture period. When the roots were treated with chitosan, the xanthone content dramatically increased, peaking after 7 days. Chitosan also induced a release of these metabolites into the culture. The maximum accumulation (14.26 ± 0.62 mg g⁻¹ dry weight [DW]) and release (2.64 ± 0.13 mg g⁻¹ DW) of xanthones were recorded 7 days after treatment. The most represented xanthones were isolated, purified, and spectroscopically characterized. Antifungal activity of the total root extracts was tested against a broad panel of human fungal pathogen strains (30 Candida species, 12 Cryptococcus neoformans, and 16 dermatophytes); this activity significantly increased when using chitosan. Extracts obtained after 7 days of chitosan treatment showed high antifungal activity (mean minimum inhibitory concentration of 83.4, 39.1, and 114 μg ml⁻¹ against Candida spp., C. neoformans, and dermatophytes, respectively). Our results suggest that root cultures can be considered as a potential tool for large-scale production of extracts with stable quantities of xanthones.     

Arginine methylation of the RGG box does not appear to regulate ICP27 import during herpes simplex virus infection

Arginine methylation can regulate protein import and export and can modulate protein interactions. Herpes simplex virus 1 (HSV-1) ICP27 is a shuttling protein involved in viral mRNA export. We previously reported that ICP27 is methylated on three arginines within its RGG box and that arginine methylation regulates ICP27 export and its interaction with SRPK1 and Aly/REF. Here, we report that ICP27 was efficiently imported into the nucleus when hypomethylated as determined by Fluorescence Recovery After Photobleaching (FRAP). Furthermore, coimmunoprecipitation of ICP27 with β-importin was not significantly affected by ICP27 hypomethylation. Thus, ICP27 import does not appear to be regulated by arginine methylation.     

Analysis of Wuchereria bancrofti infections in a village community in northern Nigeria: increased prevalence in individuals infected with Onchocerca volvulus

Infections with Wuchereria bancrofti causing lymphatic filariasis still represent one of the major health problems in the tropics, with 120 million people infected and over 750 million exposed to this filarial parasite. We have studied lymphatic filariasis infections as part of a multi-parasite survey in a village community in the savannah of northern Nigeria. We analysed serum samples from 341 individuals aged 5-70 years, detecting a W. bancrofti circulating antigen using the commercially available ICT Filariasis card test. The prevalence of infections was 10% and clearly age-dependent, increasing from below 2% in children to over 20% in subjects older than 40 years. Measuring IgG4 antibodies against the recombinant W. bancrofti antigen SXP1 showed that 36% of all tested individuals had been at least exposed to the parasite. Antibody levels also increased very significantly with age. A further analysis measuring Onchocerca volvulus-specific IgG4 antibodies showed a very significant association between infections with O. volvulus and those with W. bancrofti. Our data show that infections with W. bancrofti in Nigeria are still a frequently occurring health problem, since they are more prevalent than previously reported, and that individuals with an O. volvulus infection are more often infected with W. bancrofti than expected statistically.