Mobilization of recalcitrant phosphorous and enhancement of pepper P uptake and yield by a new biocontrol and bioremediation bacterium Burkholderia cepacia CQ18.

AIMS: Phosphorus (P) is a finite resource and inoculation of phosphorus-mobilizing bacteria (PMB) is a promising approach for the enhancement of soil P availability and plant P uptake. This drives scientists to search for the microbes effective in mobilizing legacy P in soils. METHODS AND RESULTS: The current incubation and greenhouse pot experiments were conducted to investigate P mobilization and pepper P uptake as affected by a new biocontrol and bioremediation bacterium Burkholderia cepacia CQ18. This bacterium converted Ca3 (PO4 )2 , FePO4 , AlPO4 , and lecithin into soluble inorganic P in the culture solutions and increased available P (including water-soluble P and Olsen P) in the soil. There were positive correlations between the soluble inorganic phosphorus and the exudates (protons, organic acids (oxalate and gluconate), siderophores and phosphatases) in culture solutions. Pepper plant biomass, fruit yield and P uptake changed in the sequence: chemical fertilizers plus bacterial inoculant >only chemical fertilizers >only bacterial inoculant >blank control. CONCLUSIONS: Taking into account the wide spectrums of P mobilization and simultaneous production of acid, neutral and alkaline phosphatases at a given pH, B.cepacia CQ18 may be a potential PMB used in soils with wide pH ranges. The mechanisms employed by this bacterium in the solubilization of recalcitrant inorganic P could be the efflux of protons, organic acids (oxalate and gluconate) and siderophores. Phosphatases could be of utmost importance in the mineralization of the organic P. The production of siderophores and phosphatases by of B.cepacia CQ18 could thus be crucial for not only the antagonism against plant pathogens but also the mobilization of soil sparingly available P. SIGNIFICANCE AND IMPACT OF THE STUDY: Burkholderia cepacia CQ18 could be potentially developed into a biofertilizer.

Lysobacter enzymogenes LE16 autolysates have potential as biocontrol agents-Lysobacter sp. autolysates as biofungicide.

AIMS: Biological techniques can manage plant diseases safely and in environmentally friendly ways, but their efficacy needs improvement. It is of the utmost importance to search for powerful microbes for the effective control of plant diseases. METHODS AND RESULTS: Unheated self-digestive solutions (SDS) that were heated at 100°C for 30 min(H-SDS) or stored for 12 months at room temperature (S-SDS) were prepared from Lysobacter enzymogenes LE16 broth culture to study their potential as biocontrol agents. This bacterium produced protease, phosphatase, lysozyme and siderophores in pure culture as well as 12 secondary metabolites including novel antibiotics lysobactin, WAP-8294A2 and mupirocin determined based on the antiSMASH 5.0.0 blast database. A poison plate assay revealed the antagonistic activities of SDS, H-SDS and S-SDS against an animal pathogenic bacterium Staphylococcus aureus, a phytopathogenic bacterium Pseudomonas syringae pv. tabaci, and numerous plant pathogenic fungi and oomycetes, including Colletotrichum gloeosporioides, Penicillium italicum, Alternaria alternate, Rhizoctonia solani, Didymella bryoniae, Sclerotinia sclerotiorum, Phytophthora nicotianae and Phytophthora capsici. The greenhouse experiment showed that SDS was highly effective in controlling pepper blight disease, which is caused by P. capsici. Compared with only pathogen inoculation, the application of SDS to the soil in preventive or curative treatments significantly reduced the disease incidence and index with relatively high control efficacy of 86·2-93·1%. CONCLUSIONS: SDS enriched lytic enzymes, siderophores and antibiotics, has a wide antimicrobial spectrum, and shows potential as a new, safe and effective biocontrol agent against plant diseases. SIGNIFICANCE AND IMPACT OF THE STUDY: Autolysates of the new biocontrol bacterium L. enzymogenes LE16 demonstrated the potential for industrial production and commercial use as a promising biocontrol agent in agriculture.

Neuropilin1, a novel independent prognostic factor and therapeutic target in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer, and thus, has limited treatment options. Neuropilin1 (NRP1) is a multi-functional transmembrane protein that interacts with a number of signaling receptors and plays an important role in cancer progression. Previous studies demonstrated that the expression of NRP1 is activated and promotes the progression of breast cancer particularly in TNBC compared to other molecular subtypes; however, whether or not the level of NRP1 expression is related to the progression of TNBC warrants further study. In the current study, we determined the expression and function of NRP1 and evaluated the clinical significance of NRP1 in patients with TNBC. In addition, we determined whether or not an NRP1 antagonist potentiates the inhibitory effects of paclitaxel (PTX) in patients with TNBC. In our clinical study, NRP1 had higher expression in TNBC tissues than non-TNBC tissues at the same stage, and NRP1 was an independent prognostic factor. Specifically, the high expression of NRP1 was associated with shorter survival in TNBC patients. In addition, TNBC cells treated with NRP1 antagonist significantly potentiated the effect of PTX on cell proliferation, cell migration, and apoptosis. Our findings suggest that NRP1 expression can act as an independent prognostic factor for TNBC patients, and the combination of PTX and an NRP1 antagonist may be an effective treatment regimen for TNBC.

Bone morphogenetic protein 9 facilitates osteocarcinoma cell apoptosis and inhibits in vivo tumor growth.

Osteosarcoma (OS) causes millions of death worldwide and, since there is no effective therapy, it is necessary to identify the molecular mechanism of OS, which can direct the development of new therapies. This study investigated the role of bone morphogenetic protein 9 (BMP9), a member of the transforming growth factor (TGF)-ß family, in OS development. This study first examined BMP9 expression in tissue from OS patients and normal subjects. The OS cell line (MG63) and tumor cells from OS patients were then transfected with BMP9 and cell proliferation and apoptosis were assessed. Western blot and reverse transcription-polymerase chain reaction were used to study the expression of cancer-related genes [B cell lymphoma (Bcl)-2, cleaved Caspase-3, Caspase-9, and poly ADP-ribose polymerase]. To confirm the in vivo impact of BMP9, mice were transplanted with OS tumor cells and then treated with BMP9 carried in attenuated Salmonella enterica serovar Typhimurium. Our study found that the OS tumor tissue had a lower expression of BMP9 compared to normal tissue. Transfection of BMP9 in OS and MG63 cells inhibited cell growth and promoted apoptosis. In vitro studies showed a decrease in Bcl-2 gene expression and an increase in Cyto-c, Caspase-3, and Caspase-9 expression. In vivo studies indicated that consistent treatment with BMP9 in OS mice results in inhibition of tumor growth. This study shows that BMP9 inhibition is associated with OS development and that enhanced expression of BMP9 may be a potential treatment method for OS.

Influence of sirolimus-induced TGF-ß secretion on mouse Treg cell proliferation.

We examined the effects of co-culturing CD4+ CD25+ Treg cells with sirolimus or cyclosporin A on Treg cell proliferation and differentiation and on transforming growth factor-ß (TGF-ß) and Foxp3 expression. CD4+ CD25+ Treg cells were harvested from mononuclear cells of spleens of C57BL/6 mice using immunomagnetic beads and divided into control, sirolimus, and cyclosporine groups. Following a 96-h co-culture, Treg cells were assayed by flow cytometry. FoxP3 and TGF-ß mRNA levels and secretion were assayed by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. Smad protein of the TGF-ß signaling pathway was assayed by western blot and its effect on CD4+ CD25+ FoxP3+ Treg cell proliferation was determined. Sirolimus-promoted differentiation and proliferation was examined using a TGF-ß neutralizing antibody. Sirolimus-treated CD4+ T cell TGF-ß secretion increased 2.5X over control levels (P < 0.01), but that of the cyclosporine group decreased marginally (P > 0.05). The CD4+ cell proportion decreased significantly (41.25 vs 69.22%, P < 0.01) and slightly (65.21 vs 69.22, P > 0.05) in the cyclosporine and sirolimus groups, respectively. T cell Foxp3 mRNA expression was significantly higher in the sirolimus-treated than in the cyclosporine (53.7 vs 40.2%, P < 0.05) and control groups (P < 0.01), but was significantly lower in the cyclosporine group than in controls (23.6 vs 40.2%, P < 0.01). Overall, sirolimus promoted CD4+ CD25+ Treg cell proliferation and growth in vitro, whereas cyclosporin A inhibited proliferation. Sirolimus might promote CD4+ CD25+ FoxP3+ regulatory T cell proliferation by inducing TGF-ß secretion in vivo.

Alcohol consumption promotes colorectal cancer by altering intestinal permeability.

OBJECTIVE: The purpose of this study was to uncover the potential impact of alcohol consumption on the tumorigenesis of colorectal cancer (CRC) and the underlying mechanism. PATIENTS AND METHODS: Overall survival was compared in CRC patients either with alcohol consumption or not. Subsequently, a mouse model of CRC was established by azoxymethane (AOM) administration. Tumor number and size were compared in CRC mice fed with Lieber-DeCarli liquid diet or normal diet. At last, pathological differences in cell proliferation, apoptosis, inflammation, and intestinal permeability, in intestines harvested from CRC mice fed with Lieber-DeCarli liquid diet or normal diet were assessed. RESULTS: It was found that the prognosis was worse in CRC patients with alcohol consumption. In CRC mice fed with Lieber-DeCarli liquid diet, more tumor tissues were found than those in the controls. Besides, alcohol consumption remarkably impaired intestinal permeability, making it easier for bacteria to invade epithelial cells. Moreover, oral gavage of probiotics markedly improved intestinal permeability and reduced tumor number in CRC mice fed with Lieber-DeCarli liquid diet. CONCLUSIONS: Probiotics can inhibit the development of alcohol-induced CRC by protecting intestinal permeability.

Insecticidal and cytotoxic activities of extracts of Cacalia tangutica and its two active ingredients against Musca domestica and Aedes albopictus.

The insecticidal activities of extracts from different parts of Cacalia tangutica (Franch.) H.-M. and two active ingredients, friedelin and stigmasterol, against Musca domestica L., Aedes albopictus (Skuse), and Spodoptera litura (F.) cells (SL cells) are reported. Extracts from leaves, flowers, and roots are highly active against adult M. domestica and the fourth-instar larvae of Ae. albopictus. The foliar extract was the most active with LC50 values of 1.74 mg/g and 196.94 microg/ml against adult M. domestica and fourth-instar larvae of Ae. albopictus, respectively. Extracts from stems were the least active. Friedelin and rotenone were highly active and equitoxic to these two insect species. The LC50 value of friedelin in adult M. domestica 48 h after treatment was 129.27 microg/g. The activity of stigmasterol on these two insect species was not obvious. However, the cytotoxicity of stigmasterol to S. litura cells was significantly greater than that of either friedelin or rotenone. At 25 microg/ml, the mortality of cells 24 h after treatment with stigmasterol was 23.0%. In contrast, friedelin and rotenone at the same concentration produced 16 and 18% mortality, respectively. Our results indicate differences between cytotoxicity in vitro and insect toxicity in vivo.

First Report of Tomato mosaic virus on Hibiscus rosa-sinensis in China.

Hibiscus rosa-sinensis Linn., family Malvaceae, is an attractive horticultural plant originating from China. Five viruses infecting H. rosa-sinensis that have been characterized previously are Hibiscus chlorotic ringspot virus (HCRSV, genus Carmovirus), Hibiscus latent ringspot virus (HLRSV, genus Nepovirus), Hibiscus yellow mosaic virus (genus Tobamovirus), Eggplant mottled dwarf virus (EMDV, genus Nucleorhabdovirus), and Okra mosaic virus (OkMV, genus Tymovirus) (2). Recently, two novel tobamoviruses infecting H. rosa-sinensis were characterized in Singapore and Florida (1). In this study, viral symptoms were observed on H. rosa-sinensis in Nanyang City in Henan Province, China. The systemic symptoms included dark and light green mosaic in young leaves, leaf puckering and malformation on older leaves, and significant stunting. Rod-shaped virus particles were isolated from H. rosa-sinensis expressing systemic symptoms. The virus was transmitted mechanically to 10 species from three families. Symptoms expressed on these plants included systemic leaf chlorosis and distortion on Lycopersicum esculentum, systemic mosaic on Capsicum annuum, Nicotiana tabacum, and Physalis floridana, and systemic chlorosis on Glycine max. N. tabacum-Xanthi nc and Datura stramonium were asymptomatic. The virus also produced chlorotic and necrotic local lesions on Chenopodium quinoa, C. amaranticolor, and C. murale. The virus was propagated in L. esculentum, N. tabacum, and P. floridana. Virions purified from systemically infected N. tabacum contained a single-stranded RNA of approximately 6.4 kb and a coat protein (CP) of approximately 17.6 kDa. The double-stranded RNA profile revealed a single band of approximately 6.4 kb. Sap extracted from virus-infected plants reacted positive with an antiserum prepared against Tobacco mosaic virus (TMV) using an antigen-coated plate enzyme-linked immunosorbent assay. The CP gene was amplified by reverse transcription-polymerase chain reaction with primers specific to Tomato mosaic virus (ToMV) and sequence data obtained from the resulting amplification product. The CP gene consisting of 159 amino acids (GenBank Accession No. AY313136) shared 99.37% identity with the ToMV Queensland isolate (GenBank Accession No. AF332868). On the basis of biology, serology, properties of virions, and the sequence of the CP gene, we conclude that the virus isolated from H. rosa-sinensis in China is Tomato mosaic virus(ToMV). References: (1) S. Adkins et al. Plant Dis. 87:1190, 2003. (2) M. H. V. van Regenmortel et al., eds. Virus Taxonomy. 7th Report of the ICTV, Academic Press, NY, 2000.

[Photodynamic therapy for genitourinary carcinomas--report of 26 tumors in 17 patients].

Twenty-six genito-urinary carcinomas in 17 patients were treated with photodynamic therapy (PDT). The complete response rate was 88.5%, significant response rate 7.7% and mild response rate 3.8%. Three tumors recurred (including 1 cancer in situ) during 9-23 months follow-up. Ultrastructurally, it was found that the necrosis of the malignant cells developed gradually and mitochondria was the major target of injury. No deleterious side effect was found.

[Hyperbaric oxygen treatment for cystoid macular edema secondary to retinal vein occlusion].

A prospective study was made to estimate the effect of hyperbaric oxygen (HBO) on 14 eyes of cystoid macular edema (CME) secondary to retinal vein occlusion. The visual acuity was improved 2-6 lines (average 3.6 lines) after the treatment, while the control group of 12 cases showed little improvement. The therapeutic effect was stable, however, fluorescein angiography showed no leakage reduction from the perifoveal capillaries, or visual function was enhanced prior to eventual improvement in the fundus. Since HBO therapy has few contraindications nor side effects, it is an effective modality in the treatment of CME.

Generation of infectious and pathogenic duck hepatitis virus type 1 from cloned full-length cDNA.

A full-length cDNA clone of duck hepatitis virus type 1 (DHV-1) isolated from duck was assembled in the plasmid vector pBluescript II SK+. RNA synthesized in vitro by means of a Sp6 promoter inserted in front of the cDNA produced infectious particles after transfection of BHK-21 cells, as shown by the appearance of cytopathic effect. The rescued virus was also found to be highly pathogenic to young ducks by intradermal injection and resulted in a fatal disease indistinguishable from that of wild-type virus. The availability of the first cDNA clone of DHV-1 will allow examination of the molecular mechanisms behind DHV-1 virulence and attenuation, which could in turn lead to the production of second-generation, genetically engineered DHV-1 vaccines.

Fresnel diffraction and fractal patterns from polygonal apertures.

Two compact analytical descriptions of Fresnel diffraction patterns from polygonal apertures under uniform illumination are detailed. In particular, a simple expression for the diffracted field from constituent edges is derived. These results have fundamental importance as well as specific applications, and they promise new physical insights into diffraction-related phenomena. The usefulness of the formulations is illuminated in the context of a virtual source theory that accounts for two transverse dimensions. This application permits calculation of fractal unstable-resonator modes of arbitrary order and unprecedented accuracy.

Spontaneous optical fractal pattern formation.

We report, for the first time, spontaneous nonlinear optical spatial fractals. The proposed generic mechanism employs intrinsic nonlinear dynamics both to generate an initial pattern seed and to fill out structure across decades of spatial scale. We demonstrate this in one of the simplest of nonlinear optical systems, composed of a Kerr slice and a single-feedback mirror. In this case, the smallest pattern scales are limited by either the optical wavelength or the diffusion length of the medium photoexcitation. The dimension characteristics of these particular fractals are also derived.

Sequence differences between human muscle and liver cDNAs for UDPglucose pyrophosphorylase and kinetic properties of the recombinant enzymes expressed in Escherichia coli.

UDP-Glc pyrophosphorylase (EC 2.7.7.9) catalyses the interconversion of MgUTP plus Glc1P and UDP-Glc plus MgPPi. Complementation of an Escherichia coli strain lacking this activity has allowed isolation of cDNA encoding this enzyme from a human muscle library. Two forms were identified and the nucleotide sequence of each was determined; they were found to differ only in the 5' region and we suggest that these arise from the use of a different first exon in the two transcripts. These nucleotide sequences are different from that of the cDNA which was isolated previously from a human liver library [Peng, H.-L. & Chang, H.-Y. (1993) FEBS Lett. 329, 153-158] and it is proposed that these liver and muscle forms are derived from different genes. The cDNA for muscle form I, muscle form II, the liver form, and the liver form fused to part of the lacZ gene were expressed in Escherichia coli and the kinetic properties of each enzyme were characterised. Muscle form I and the LacZ/liver fusion enzyme exhibit Michaelis-Menten kinetics towards all substrates while muscle form II has a sigmoidal dependence of rate upon the concentration of MgPPi. The liver form shows Michaelis-Menten kinetics towards MgUTP. For the remaining three substrates, complex kinetics were observed involving a combination of sigmoidicity at low substrate concentration and partial inhibition at high substrate concentration.