Hyperthermic treatment of DMBA-induced rat mammary cancer using magnetic nanoparticles

Background

We have developed magnetite cationic liposomes (MCLs) and applied them as a mediator of local hyperthermia. MCLs can generate heat under an alternating magnetic field (AMF). In this study, the in vivo effect of hyperthermia mediated by MCLs was examined using 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary cancer as a spontaneous cancer model.

Method

MCLs were injected into the mammary cancer and then subjected to an AMF.

Results

Four rats in 20 developed mammary tumors at more than 1 site in the body. The first-developed tumor in each of these 4 rats was selected and heated to over 43°C following administration of MCLs by an infusion pump. After a series of 3 hyperthermia treatments, treated tumors in 3 of the 4 rats were well controlled over a 30-day observation period. One of the 4 rats exhibited regrowth after 2 weeks. In this rat, there were 3 sites of tumor regrowth. Two of these regrowths were reduced in volume and regressed completely after 31 days, although the remaining one grew rapidly. These results indicated hyperthermia-induced immunological antitumor activity mediated by the MCLs.

Conclusion

Our results suggest that hyperthermic treatment using MCLs is effective in a spontaneous cancer model.

     

Magnetic characterization of superparamagnetic nanoparticles pulled through model membranes

Background

To quantitatively compare in-vitro and in vivo membrane transport studies of targeted delivery, one needs characterization of the magnetically-induced mobility of superparamagnetic iron oxide nanoparticles (SPION). Flux densities, gradients, and nanoparticle properties were measured in order to quantify the magnetic force on the SPION in both an artificial cochlear round window membrane (RWM) model and the guinea pig RWM.

Methods

Three-dimensional maps were created for flux density and magnetic gradient produced by a 24-well casing of 4.1 kilo-Gauss neodymium-iron-boron (NdFeB) disc magnets. The casing was used to pull SPION through a three-layer cell culture RWM model. Similar maps were created for a 4 inch (10.16 cm) cube 48 MGOe NdFeB magnet used to pull polymeric-nanoparticles through the RWM of anesthetized guinea pigs. Other parameters needed to compute magnetic force were nanoparticle and polymer properties, including average radius, density, magnetic susceptibility, and volume fraction of magnetite.

Results

A minimum force of 5.04 × 10^-16 N was determined to adequately pull nanoparticles through the in-vitro model. For the guinea pig RWM, the magnetic force on the polymeric nanoparticles was 9.69 × 10^-20 N. Electron microscopy confirmed the movement of the particles through both RWM models.

Conclusion

As prospective carriers of therapeutic substances, polymers containing superparamagnetic iron oxide nanoparticles were succesfully pulled through the live RWM. The force required to achieve in vivo transport was significantly lower than that required to pull nanoparticles through the in-vitro RWM model. Indeed very little force was required to accomplish measurable delivery of polymeric-SPION composite nanoparticles across the RWM, suggesting that therapeutic delivery to the inner ear by SPION is feasible.

     

Spring to autumn changes in the arbuscular mycorrhizal fungal community composition in the different propagule types associated to a Mediterranean shrubland

Background and aims

Arbuscular mycorrhizal fungi (AMF) appear differentially represented among propagule forms [intraradical mycelium (IRM) in colonized roots, spores and extraradical mycelium (ERM)]. However, spring to autumn changes in the AMF communities harboured in the different propagule forms has not been studied, being this the aim of the present study.

Methods

A terminal restriction fragment length polymorphism approach was used to monitor, in spring and autumn, the AMF community composition present in the three propagule types associated to five shrub species in a semi-arid Mediterranean environment.

Results

The AMF community composition in roots was significantly different between spring and autumn; however, no significant differences were detected in soil propagules (spores and ERM). Different trends were identified according to the preferential biomass allocation patterns of AMF phylotypes, suggesting different life strategies: those allocating mainly into IRM (belonging to the Glomeraceae), ERM (Diversisporaceae and Gigasporaceae) or spores (Pacisporaceae and Paraglomeraceae).

Conclusions

Differences of AMF taxa in the biomass allocation patterns among propagules are maintained throughout the year. Progress in the knowledge of functional features of AMF communities and their responses to seasonal variations are important for the AMF application in Mediterranean ecosystems.

     

Green synthesis of gold nanoparticles by a newly isolated strain <Emphasis Type="Italic">Trichosporon</Emphasis><Emphasis Type="Italic">montevideense</Emphasis> for catalytic hydrogenation of nitroaromatics

Objective

To investigate green synthesis of gold nanoparticles (AuNPs) by Trichosporon montevideense, and to study their reduction of nitroaromatics.

Results

AuNPs had a characteristic absorption maximum at 535 nm. Scanning electron microscopy images revealed that the biosynthesized nanoparticles were attached on the cell surface. X-ray diffraction analysis indicated that the particles formed as face-centered cubic (111)-oriented crystals. The average size of AuNPs decreased from 53 to 12 nm with increasing biomass concentration. The catalytic reduction of 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, o-nitrophenylamine and m-nitrophenylamine (0.1 mM) by NaBH₄ had reaction rate constants of 0.32, 0.44, 0.09, 0.24 and 0.39 min^?1 with addition of 1.45 × 10^?2 mM AuNPs.

Conclusions

An eco-friendly approach for synthesis of AuNPs by T. montevideense is reported for the first time. The biogenic AuNPs could serve as efficient catalysts for hydrogenation of various nitroaromatics.

     

pH as a proxy for estimating plant-available Si? A case study in rice fields in Karnataka (South India)

Background and aims

Soil nutrient dynamics are affected by root-microbe interactions and plant development. We investigated the influence of plant growth stage and arbuscular mycorrhiza fungi (AMF) on carbon (C) and nitrogen (N) rhizodeposition and the transfer into the microbial biomass (MB).

Methods

Pea varieties (Pisum sativum L.) with (Frisson) and without mycorrhiza (P2) were ¹³C-¹⁵N-labelled and harvested at 45, 63, 71, and 95 days after sowing. Mycorrhization, MB, total C, N, ¹³C, ¹⁵N were determined in plant and soil compartments to calculate C and N derived from rhizodeposition (CdfR, NdfR).

Results

Total CdfR increased until pea maturity, NdfR until end of flowering. Their relative contribution steadily decreased over time, accounting for 4–10% of total plant C and N at harvest. Rhizodeposition contributed between 1 and 6% to MB C and N, although 20% of the rhizodeposits were discovered in the MB. Frisson released more NdfR than P2 but it was not possible to accurately estimate AMF effects on C and N due to differences in biomass partitioning.

Conclusions

CdfR followed an even flow from early growth until senescence. NdfR flow ceased after flowering possibly due to N relocation within the plant. Rhizodeposits contribute very little to MB in our study.

     

Silicon acquisition by bananas (c.V. Grande Naine) is increased in presence of the arbuscular mycorrhizal fungus <Emphasis Type="Italic">Rhizophagus irregularis</Emphasis> MUCL 41833

Aim

This work aimed to investigate the role of arbuscular mycorrhizal fungi (AMF) in the uptake and accumulation of silicon (Si) in banana plants. Si is recognized as a significant element that helps plants resist stresses.

Methods

A pot experiment compared the growth, Si and P accumulation of banana plants pre-colonized or not by an AMF and exposed or not to Si added to the growth substrate.

Results

A marked increase in Si was noticed in pseudostem, leaves and roots of pre-colonized banana plants, in presence as well as in absence of Si added to the growth substrate. Without Si addition, this accumulation was 60 % and 45 % higher in pseudostem and leaves, respectively, while it was 47 % and 41 % in presence of Si added to the substrate. In roots, this increase was 23 % and 52 % in presence and absence of Si added to the substrate, respectively. Phosphorus content in shoots and roots was likewise significantly increased in presence of AMF or Si.

Conclusion

Our findings revealed that pre-colonized banana plants accumulated more Si in shoot and roots than non-mycorrhizal plants and may thus represent a potential novel avenue to explore banana resistance to pests and diseases.

     

Maximizing power generation from dark fermentation effluents in microbial fuel cell by selective enrichment of exoelectrogens and optimization of anodic operational parameters

Objective

To selectively enrich an electrogenic mixed consortium capable of utilizing dark fermentative effluents as substrates in microbial fuel cells and to further enhance the power outputs by optimization of influential anodic operational parameters.

Results

A maximum power density of 1.4 W/m³ was obtained by an enriched mixed electrogenic consortium in microbial fuel cells using acetate as substrate. This was further increased to 5.43 W/m³ by optimization of influential anodic parameters. By utilizing dark fermentative effluents as substrates, the maximum power densities ranged from 5.2 to 6.2 W/m³ with an average COD removal efficiency of 75% and a columbic efficiency of 10.6%.

Conclusion

A simple strategy is provided for selective enrichment of electrogenic bacteria that can be used in microbial fuel cells for generating power from various dark fermentative effluents.

     

Influence of diligent disintegration on anaerobic biomass and performance of microbial fuel cell

Objectives

To enhance the performance of microbial fuel cells (MFC) by increasing the surface area of cathode and diligent mechanical disintegration of anaerobic biomass.

Results

Tannery effluent and anaerobic biomass were used. The increase in surface area of the cathode resulted in 78% COD removal, with the potential, current density, power density and coulombic efficiency of 675 mV, 147 mA m^?2, 33 mW m^?2 and 3.5%, respectively. The work coupled with increased surface area of the cathode with diligent mechanical disintegration of the biomass, led to a further increase in COD removal of 82% with the potential, current density, power density and coulombic efficiency of 748 mV, 229 mA m^?2, 78 mW m^?2 and 6% respectively.

Conclusions

Mechanical disintegration of the biomass along with increased surface area of cathode enhances power generation in vertical MFC reactors using tannery effluent as fuel.

     

NMRProcFlow: a graphical and interactive tool dedicated to 1D spectra processing for NMR-based metabolomics

Introduction

Concerning NMR-based metabolomics, 1D spectra processing often requires an expert eye for disentangling the intertwined peaks.

Objectives

The objective of NMRProcFlow is to assist the expert in this task in the best way without requirement of programming skills.

Methods

NMRProcFlow was developed to be a graphical and interactive 1D NMR (¹H & ¹³C) spectra processing tool.

Results

NMRProcFlow (http://nmrprocflow.org), dedicated to metabolic fingerprinting and targeted metabolomics, covers all spectra processing steps including baseline correction, chemical shift calibration and alignment.

Conclusion

Biologists and NMR spectroscopists can easily interact and develop synergies by visualizing the NMR spectra along with their corresponding experimental-factor levels, thus setting a bridge between experimental design and subsequent statistical analyses.

     

Three symbionts involved in interspecific plant-soil feedback: epichloid endophytes and mycorrhizal fungi affect the performance of rhizobia-legume symbiosis

Aims

Plants interact by modifying soil conditions in plant-soil feedback processes. Foliar endophytes of grasses exert multiple effects on host rhizosphere with potential consequences on plant-soil feedback. Here, we hypothesize that the grass-endophyte symbiosis impairs soil symbiotic potential, and in turn influences legume performance and nitrogen acquisition.

Methods

Soil was conditioned in pots, growing Lolium multiflorum with or without the fungal endophyte Epichloë and with or without arbuscular mycorrhizal fungi (AMF). Then, Trifolium repens grew in all types of conditioned soils with high or low rhizobia availability.

Results

Endophyte soil conditioning reduced AMF spores number and rhizobial nodules (?27 % and ?38 %, respectively). Seedling survival was lower in endophyte-conditioned soil and higher in mycorrhizal soils (?27 % and +24 %, respectively). High rhizobia-availability allowed greater growth and nitrogen acquisition, independent of soil conditioning. Low rhizobia-availability allowed both effects only in endophyte-conditioned soil.

Conclusion

Endophyte-induced changes in soil (i) hindered symbiotic potential by reducing AMF spore availability or rhizobia nodulation, (ii) impaired legume survival irrespective of belowground symbionts presence, but (iii) mimicked rhizobia effects, enhancing growth and nitrogen fixation in poorly nodulated plants. Our results show that shoot and root symbionts can be interactively involved in interspecific plant-soil feedback.

     

<Emphasis Type="Italic">Epichloë</Emphasis> exudates promote in vitro and in vivo arbuscular mycorrhizal fungi development and plant growth

Background and aims

We studied, through exudates employment, the effect of Epichloë (endophytic fungi), both independently and in association with Bromus auleticus (grass), on arbuscular mycorrhizal fungi (AMF) colonization, host and neighbouring plants biomass production and soil changes.

Methods

Through in vitro and greenhouse experiments, Epichloë endophytes effect on AMF development was evaluated. In vitro studies of exudates effect on Gigaspora rosea and Rhizophagus intraradices were performed using root or endophyte exudates. A 6-month greenhouse experiment was conducted to determine Bromus auleticus endophytic status effect and endophyte exudates role in biomass production, neighbouring plants mycorrhizal colonization and soil properties.

Results

Endophyte exudates and E+ plant root exudates promoted in vitro AMF development in the pre-infective stage of G. rosea and in carrot root culture mycelium of R. intraradices in a dose-response relationship, while control media and E- plants exudates had no effect. R. intraradices colonization and plant growth was clearly increased by endophytes and their exudates.

Conclusions

This is the first work evidencing the direct effect of Epichloë endophytes and infected plants root exudates on AMF extramatrical development. While higher levels of AMF colonization were observed in E+ plants, no clear effect was detected in neighbouring plants colonization, plant biomass or soil properties.

     

Effects of magnesium deficiency on magnesium uptake activity of rice root,evaluated using <Superscript>28</Superscript> Mg as a tracer

Aims

The mechanisms underlying magnesium (Mg) uptake by plant roots remain to be fully elucidated. In particular, there is little information about the effects of Mg deficiency on Mg uptake activity. A Mg uptake kinetic study is essential for better understanding the Mg uptake system.

Methods

We performed a Mg uptake tracer experiment in rice plants using ²⁸?Mg.

Results

Mg uptake was mediated by high- and low-affinity transport systems. The K _m value of the high-affinity transport system was approximately 70 μM under Mg-deficient conditions. The Mg uptake activity was promoted by Mg deficiency, which in turn fell to the basal level after 5- min of Mg resupply. The induced uptake rate was inhibited by ionophore treatment, suggesting that an energy-dependent uptake system is enhanced by Mg deficiency.

Conclusions

The Mg uptake changes rapidly with Mg conditions in rice, as revealed by a ²⁸?Mg tracer experiment. This technique is expected to be applicable for Mg uptake analyses, particularly in mutants or other lines.

     

Characterization of ankylosing spondylitis and rheumatoid arthritis using <Superscript>1</Superscript>H NMR-based metabolomics of human fecal extracts

Introduction

The differences in fecal metabolome between ankylosing spondylitis (AS)/rheumatoid arthritis (RA) patients and healthy individuals could be the reason for an autoimmune disorder.

Objectives

The study explored the fecal metabolome difference between AS/RA patients and healthy controls to clarify human immune disturbance.

Methods

Fecal samples from 109 individuals (healthy controls 34, AS 40, and RA 35) were analyzed by ¹H NMR spectroscopy. Data were analyzed with principal component analysis (PCA) and orthogonal projection to latent structure discriminant (OPLS-DA) analysis.

Results

Significant differences in the fecal metabolic profiles could distinguish AS/RA patients from healthy controls but could not distinguish between AS and RA patients. The significantly decreased metabolites in AS/RA patients were butyrate, propionate, methionine, and hypoxanthine. Significantly increased metabolites in AS/RA patients were taurine, methanol, fumarate, and tryptophan.

Conclusion

The metabolome variations in feces indicated AS and RA were two homologous diseases that could not be distinguished by ¹H NMR metabolomics.

     

Is there evidence of fetal-maternal heart rate synchronization?

Background

The prenatal condition offers a unique possibility of examining physiological interaction between individuals. Goal of this work was to look for evidence of coordination between fetal and maternal cardiac systems.

Methods

177 magnetocardiograms were recorded in 62 pregnancies (16^th–42^nd week of gestation). Fetal and maternal RR interval time series were constructed and the phases, i.e. the timing of the R peaks of one time series in relation to each RR interval of the other were determined. The distributions of these phases were examined and synchrograms were constructed for real and surrogate pairs of fetal and maternal data sets. Synchronization epochs were determined for defined n:m coupling ratios.

Results

Differences between real and surrogate data could not be found with respect to number of synchronization epochs found (712 vs. 741), gestational age, subject, recording or n:m combination. There was however a preference for the occurrence of synchronization epochs in specific phases in real data not apparent in the surrogate for some n:m combinations.

Conclusion

The results suggest that occasional coupling between fetal and maternal cardiac systems does occur.

     

Changes from pasture to a native tree plantation affect soil organic matter in a tropical soil,Panamá

Background and aims

We examined changes in soil organic matter arising from conversion of a 45-year old pasture to a 10 yr. old native tree plantation in Panamá, to evaluate the effect of monoculture and mixtures.

Methods

We intensively sampled the soil 0–10 cm depth in the pasture in 2001 and in 22 plantation plots in 2011, ranging from 5 monocultures to 3- and 6-species treatments; samples were also taken from an undisturbed forest site. Soil analyses included organic carbon (SOC) and δ¹³C.

Results

Conversion of the pasture to tree plantation resulted in an overall loss of SOC of 0.6 kg m^?2 (18%) in the top 10 cm, but neither tree species nor diversity had a significant effect. End-member δ¹³C values suggested that the contribution of C₃ plants to SOC was increased from 26% in the pasture to 55% after 10 years of plantation and SOC turnover times were calculated to be 21–36 yr.

Conclusions

The magnitude of the loss in soil SOC is smaller than the increases in tree biomass (~3 kg C m^?2) and litter (~0.3 kg C m^?2) in the plantation, but still a significant part of the ecosystem C balance.

     

Enhancement of production and activity of alkaline zinc metalloprotease from <Emphasis Type="Italic">Salinivibrio proteolyticus</Emphasis> using low intensity direct electric current and zinc nanoparticles

Objectives

To improve the production and activity of an alkaline zinc metalloprotease from Salinivibrio proteolyticus in response to ZnSO₄ (ionic and nanoparticle forms) and low intensity direct electric current (LIDC).

Results

A DC of 50 µA for 10 min increased enzyme production from 35 to 53 U ml^?1 when applied to the stationary phase bacterial cells. Zn²⁺ improved enzyme production better than zinc nanoparticles (52 vs. 43.5 U ml^?1). Zinc nanoparticles (0.5 mM) added to an enzyme reaction mixture containing casein (0.65 %) and 20 mM Tris/HCl buffer (pH 8) improved enzyme activity more than Zn²⁺ (42 vs. 36 U ml^?1).

Conclusion

LIDC exposure (50 µA, 10 min) to the stationary phase bacterial cells increases metalloprotease production in Salinivibrio. A low concentration of zinc nanoparticles (0.5 mM) increases maximum enzyme activity.

     

Optimization of fecal sample preparation for untargeted LC-HRMS based metabolomics

Introduction

Collecting feces is easy. It offers direct outcome to endogenous and microbial metabolites.

Objectives

In a context of lack of consensus about fecal sample preparation, especially in animal species, we developed a robust protocol allowing untargeted LC-HRMS fingerprinting.

Methods

The conditions of extraction (quantity, preparation, solvents, dilutions) were investigated in bovine feces.

Results

A rapid and simple protocol involving feces extraction with methanol (1/3, M/V) followed by centrifugation and a step filtration (10 kDa) was developed.

Conclusion

The workflow generated repeatable and informative fingerprints for robust metabolome characterization.

     

Impaired mitochondrial calcium uptake caused by tacrolimus underlies beta-cell failure

Background

One of the most common side effects of the immunosuppressive drug tacrolimus (FK506) is the increased risk of new-onset diabetes mellitus. However, the molecular mechanisms underlying this association have not been fully clarified.

Methods

We studied the effects of the therapeutic dose of tacrolimus on mitochondrial fitness in beta-cells.

Results

We demonstrate that tacrolimus impairs glucose-stimulated insulin secretion (GSIS) in beta-cells through a previously unidentified mechanism. Indeed, tacrolimus causes a decrease in mitochondrial Ca²⁺ uptake, accompanied by altered mitochondrial respiration and reduced ATP production, eventually leading to impaired GSIS.

Conclusion

Our observations individuate a new fundamental mechanism responsible for the augmented incidence of diabetes following tacrolimus treatment. Indeed, this drug alters Ca²⁺ fluxes in mitochondria, thereby compromising metabolism-secretion coupling in beta-cells.

     

Functional characterization of recombinant human granulocyte colony stimulating factor (hGMCSF) immobilized onto silica nanoparticles

Objectives

Granulocyte macrophage colony stimulating factor (GMCSF), an important therapeutic cytokine, was immobilized onto silica nanoparticles. Maintenance of structural integrity and biological performance in immobilized cytokine was assessed to augment its applicability in possible biomedical implications.

Results

Following its cloning and expression in E. coli, the recombinant human GMCSF (hGMCSF) was purified as a GST-tagged protein corresponding to a 42 kDa band on SDS-PAGE. The purified cytokine was immobilized onto biocompatible silica nanoparticles (~129.4 nm) by adsorption and the binding was confirmed by dynamic light scattering and infrared spectroscopy. Maximum binding of hGMCSF was at 6.4 µg mg^?1 silica nanoparticles. Efficient release of the cytokine from the nanoparticles with its structural integrity intact was deduced from circular dichroism spectroscopy. hGMCSF-immobilized silica nanoparticles efficiently increased the proliferation of RAW 264.7 macrophage cells with 50 % increase in proliferation at 600 ng hGMCSF µg^?1 silica nanoparticles.

Conclusions

Silica nanoparticles successfully immobilized hGMCSF maintaining its structural integrity. The release of the immobilized cytokine from silica nanoparticles resulted in the increased proliferation of macrophages indicating the potential of the system in future applications.

     

A lost opportunity for science: journals promote data sharing in metabolomics but do not enforce it

Introduction

Data sharing is being increasingly required by journals and has been heralded as a solution to the ‘replication crisis’.

Objectives

(i) Review data sharing policies of journals publishing the most metabolomics papers associated with open data and (ii) compare these journals’ policies to those that publish the most metabolomics papers.

Methods

A PubMed search was used to identify metabolomics papers. Metabolomics data repositories were manually searched for linked publications.

Results

Journals that support data sharing are not necessarily those with the most papers associated to open metabolomics data.

Conclusion

Further efforts are required to improve data sharing in metabolomics.