Iron Isotope Fractionation during Fe(II) Oxidation Mediated by the Oxygen-Producing Marine Cyanobacterium Synechococcus PCC 7002

In this study, we couple iron isotope analysis to microscopic and mineralogical investigation of iron speciation during circumneutral Fe(II) oxidation and Fe(III) precipitation with photosynthetically produced oxygen. In the presence of the cyanobacterium Synechococcus PCC 7002, aqueous Fe(II) (Fe(II)_aq) is oxidized and precipitated as amorphous Fe(III) oxyhydroxide minerals (iron precipitates, Fe_ppt), with distinct isotopic fractionation (ε⁵⁶Fe) values determined from fitting the δ⁵⁶Fe(II)_aq (1.79‰ and 2.15‰) and the δ⁵⁶Fe_ppt (2.44‰ and 2.98‰) data trends from two replicate experiments. Additional Fe(II) and Fe(III) phases were detected using microscopy and chemical extractions and likely represent Fe(II) and Fe(III) sorbed to minerals and cells. The iron desorbed with sodium acetate (Fe_NaAc) yielded heavier δ⁵⁶Fe compositions than Fe(II)_aq. Modeling of the fractionation during Fe(III) sorption to cells and Fe(II) sorption to Fe_ppt, combined with equilibration of sorbed iron and with Fe(II)_aq using published fractionation factors, is consistent with our resulting δ⁵⁶Fe_NaAc. The δ⁵⁶Fe_ppt data trend is inconsistent with complete equilibrium exchange with Fe(II)_aq. Because of this and our detection of microbially excreted organics (e.g., exopolysaccharides) coating Fe_ppt in our microscopic analysis, we suggest that electron and atom exchange is partially suppressed in this system by biologically produced organics. These results indicate that cyanobacteria influence the fate and composition of iron in sunlit environments via their role in Fe(II) oxidation through O₂ production, the capacity of their cell surfaces to sorb iron, and the interaction of secreted organics with Fe(III) minerals.

Application of percutaneous epididymal sperm aspiration in azoospermia

OBJECTIVE

The present study introduces the application of percutaneous epididymal sperm aspiration (PESA) for diagnosis of obstructive azoospermia and non-obstructive azoospermia.

PATIENTS AND METHODS

96 cases diagnosed with azoospermia were selected, standard methods were used to measure testicular volume, chemiluminescence was used to test serum sexual hormone levels, and No. 7 butterfly needles were applied to puncture the head of the epididymis and aspirate epididymal luminal fluid.

RESULTS

Among 96 cases of azoospermia, sperm was found in the epididymal luminal fluid of 49 cases, among which there were 41 cases with normal testicular volume and 8 cases with low volume. 39 cases had normal serum FSH levels, and 10 cases had increased serum FSH levels. There were 47 cases with no sperm, among which there were 26 cases with normal testicular volume and 21 cases with low volume. 29 cases had normal serum FSH levels, and 18 cases had increased levels. The success rate of puncture for patients with normal testicular volume was higher than that of patients with low volume, and the difference was statistically significant (p < 0.05). The success rate of puncture for patients with normal serum FSH levels was higher than that of patients with increased levels, and the difference was statistically significant (p < 0.05).

CONCLUSIONS

PESA is simple and efficient, and is a feasible method for diagnosis of azoospermia.

Meningococcal carriage in Dutch adolescents and young adults; a cross-sectional and longitudinal cohort study

OBJECTIVES

Current information on rates and dynamics of meningococcal carriage is essential for public health policy. This study aimed to determine meningococcal carriage prevalence, its risk factors and duration in the Netherlands, where meningococcal C vaccine coverage is >90%. Several methods to identify serogroups of meningococcal carriage isolates among adolescent and young adults were compared.

METHODS

Oropharyngeal swabs were collected from 1715 participants 13-23 years of age in 2013-2014; 300 were prospectively followed over 8 months. Cultured isolates were characterized by Ouchterlony, real-time (rt-) PCR or whole-genome sequencing (WGS). Direct swabs were assessed by rt-PCR. Questionnaires on environmental factors and behaviour were also obtained.

RESULTS

A meningococcal isolate was identified in 270/1715 (16%) participants by culture. Of MenB isolates identified by whole genome sequencing, 37/72 (51%) were correctly serogrouped by Ouchterlony, 46/51 (90%) by rt-PCR of cultured isolates, and 39/51 (76%) by rt-PCR directly on swabs. A sharp increase in carriage was observed before the age of 15 years. The age-related association disappeared after correction for smoking, level of education, frequent attendance to crowded social venues, kissing in the previous week and alcohol consumption. Three participants carried the same strain identified at three consecutive visits in an 8-month period. In these isolates, progressively acquired mutations were observed.

CONCLUSIONS

Whole genome sequencing of culture isolates was the most sensitive method for serogroup identification. Based upon results of this study and risk of meningococcal disease, an adolescent meningococcal vaccination might include children before the age of 15 years to confer individual protection and potentially to establish herd protection.

[Effect of CIK on long-term survival in the treatment of HCC after RFA combined TACE]

OBJECTIVE

To evaluate the clinical effects of autologous cytokine-induced killer cell(CIK) on the cumulative survival and reactivation rate of hepatitics B virus(HBV) after radiofrequency ablation(RFA) combined with transcatheter arterial chemoembolization(TACE).

METHODS

A total of 156 patients with hepatocellular carcinoma treated from June 2006 to September 2012 in Shengli Oilfield Central Hosptial were divided into control group(RFA, TACE) and research group(RFA, TACE, CIK). According to the tumors number, diameter and vascular invasion condition, the patients were divided into another 4 groups: the high and low risk group with tumor ≤5 cm, the high and low risk group with tumor>5 cm.The prognosis of these groups was analyzed. The effects on HBV reactivation rate between antiviral and unantiviral patients were respectively analyzed .

RESULTS

The ratios of the research and control group over 1-, 3-, 5-year were 75.3%(70/93), 58.9%(53/90), 21.5%(20/93)vs 71.4%(45/63), 55.6%(35/63), 22.2%(14/63)(P>0.05), the ratios of the research and control group in the high risk group with tumor≤5 cm were 75.0%(18/24), 58.3%(14/24), 37.5%(9/24)vs 58.8%(10/17), 41.2%(7/17), 23.5%(4/17)(P<0.05). The incidences of HBV reactivation for the research and control group were 6.0% and 24.3%(P<0.05).

CONCLUSION

Postoperative adjuvant CIK therapy with tumor≤5 cm after RFA combined with TACE is beneficial to the high risk group and decreases the risk of HBV reactivation.

Meta-analysis of alkaline phosphatase and prognosis for osteosarcoma

Many studies have evaluated the relationships between alkaline phosphatase (ALP) levels and the prognosis for osteosarcoma. However, a consensus has yet to be reached. We completed a meta-analysis to assess the significance of ALP and prognosis for osteosarcoma. We retrieved eligible documents from the PubMed and Embase databases and extracted related data from those documents. The overall survival (OS), hazard ratio (HR) and event-free survival (EFS) HR were obtained after combination to evaluate the impacts of ALP levels on prognosis for osteosarcoma. After screening, a total of 12 documents published between 1999 and 2013 were included. The ALP levels on OS were evaluated in nine documents. The pooled HRs was 1.78 (95% CI: 1.52-2.07, p < .05). The ALP levels on EFS were determined in eight documents. The pooled HRs was 1.58 (95% CI: 1.37-1.82, p < .05). Begg's test (OS, p > .754; EFS, p > .386) and Egger's test (OS, p > .649; EFS, p > .274) showed that there was no significant publication bias during analytic process. In summary, our meta-analysis shows that a higher level of ALP can decrease the OS and EFS in patients with osteosarcoma and ALP is an important biological indicator for patients with osteosarcoma.

Correlation of p-doping in CVD Graphene with Substrate Surface Charges

Correlations between the level of p-doping exhibited in large area chemical vapour deposition (CVD) graphene field effect transistor structures (gFETs) and residual charges created by a variety of surface treatments to the silicon dioxide (SiO2) substrates prior to CVD graphene transfer are measured. Beginning with graphene on untreated thermal oxidised silicon, a minimum conductivity (σ(min)) occurring at gate voltage V(g) = 15 V (Dirac Point) is measured. It was found that more aggressive treatments (O2 plasma and UV Ozone treatments) further increase the gate voltage of the Dirac point up to 65 V, corresponding to a significant increase of the level of p-doping displayed in the graphene. An electrowetting model describing the measured relationship between the contact angle (θ) of a water droplet applied to the treated substrate/graphene surface and an effective gate voltage from a surface charge density is proposed to describe biasing of V(g) at σ(min) and was found to fit the measurements with multiplication of a correction factor, allowing effective non-destructive approximation of substrate added charge carrier density using contact angle measurements.

Influence of COD:N ratio on sludge properties and their role in membrane fouling of a submerged membrane bioreactor

The effect of COD:N ratio on sludge properties and their role in membrane fouling were examined using a well-controlled aerobic membrane bioreactor receiving a synthetic high strength wastewater containing glucose. Membrane performance was improved with an increase in the COD/N ratio (100:5-100:1.8) (i.e. reduced N dosage). Surface analysis of sludge by X-ray photoelectron spectroscopy (XPS) indicates significant differences in surface concentrations of elements C, O and N that were observed under different COD/N ratios, implying changes in the composition of extracellular polymeric substances (EPS). Fourier transform-infrared spectroscopy (FTIR) revealed a unique characteristic peak (CO bonds) at 1735 cm(-1) under nitrogen limitation conditions. Total EPS decreased with an increase in COD/N ratio, corresponding to a decrease in the proteins (PN) to carbohydrates (CH) ratio in EPS. There were no significant differences in the total soluble microbial products (SMPs) but the ratio of PN/CH in SMPs decreased with an increase in COD/N ratios. The results suggest that EPS and SMP composition and the presence of a small quantity of filamentous microorganisms played an important role in controlling membrane fouling.

The silencing of cathepsin K used in gene therapy for periodontal disease reveals the role of cathepsin K in chronic infection and inflammation

BACKGROUND AND OBJECTIVE

Periodontitis is a severe chronic inflammatory disease and one of the most prevalent non-communicable chronic diseases that affects the majority of the world's adult population. While great efforts have been devoted toward understanding the pathogenesis of periodontitis, there remains a pressing need for developing potent therapeutic strategies for targeting this dreadful disease. In this study, we utilized adeno-associated virus (AAV) expressing cathepsin K (Ctsk) small hairpin (sh)RNA (AAV-sh-Ctsk) to silence Ctsk in vivo and subsequently evaluated its impact in periodontitis as a potential therapeutic strategy for this disease.

MATERIAL AND METHODS

We used a known mouse model of periodontitis, in which wild-type BALB/cJ mice were infected with Porphyromonas gingivalis W50 in the maxillary and mandibular periodontium to induce the disease. AAV-sh-Ctsk was then administrated locally into the periodontal tissues in vivo, followed by analyses to assess progression of the disease.

RESULTS

AAV-mediated Ctsk silencing drastically protected mice (> 80%) from P. gingivalis-induced bone resorption by osteoclasts. In addition, AAV-sh-Ctsk administration drastically reduced inflammation by impacting the expression of many inflammatory cytokines as well as T-cell and dendritic cell numbers in periodontal lesions.

CONCLUSION

AAV-mediated Ctsk silencing can simultaneously target both the inflammation and bone resorption associated with periodontitis through its inhibitory effect on immune cells and osteoclast function. Thereby, AAV-sh-Ctsk administration can efficiently protect against periodontal tissue damage and alveolar bone loss, establishing this AAV-mediated local silencing of Ctsk as an important therapeutic strategy for effectively treating periodontal disease.

Analysing codon usage bias of cyprinid herpesvirus 3 and adaptation of this virus to the hosts

The codon usage patterns of open reading frames (ORFs) in cyprinid herpesvirus 3 (CyHV-3) have been investigated in this study. The high correlation between GC12 % and GC3 % suggests that mutational pressure rather than natural selection is the main factor that determines the codon usage and base component in the CyHV-3, while mutational pressure effect results from the high correlation between GC3 % and the first principal axis of principle component analysis (Axis 1) on the relative synonymous codon usage (RSCU) value of the viral functional genes. However, the interaction between the absolute codon usage bias and GC3 % suggests that other selections take part in the formation of codon usage, except for the mutational pressure. It is noted that the similarity degree of codon usage between the CyHV-3 and goldfish, Carassius auratus (L.), is higher than that between the virus and common carp, Cyprinus carpio L., suggesting that the goldfish plays a more important role than the common carp in codon usage pattern of the CyHV-3. The study of codon usage in CyHV-3 can provide some evidence about the molecular evolution of the virus. It can also enrich our understanding about the relationship between the CyHV-3 and its hosts by analysing their codon usage patterns.

Effect of organic matter to nitrogen ratio on membrane bioreactor performance

Effect of chemical oxygen demand (COD) to nitrogen (COD:N) ratio in feed on the performance of aerobic membrane bioreactor (MBR) for treating a synthetic high-strength industrial waste water containing glucose was studied for over 370 days. The widely recommended nutrients ratio (COD:N:P = 100:5:1) is not necessary for aerobic biological industrial waste water treatment. An increased COD:N ratio from 100:5 to 100:2.5 and 100:1.8 had a limited impact on COD removal efficiency and further led to a significant improvement in membrane performance, a reduced sludge yield, and improved effluent quality in terms of residual nutrients. An increased COD:N ratio will benefit the industrial waste water treatment using MBRs by reducing membrane fouling and sludge yield, saving chemical costs, and reducing secondary pollution by nutrients addition. Optimization of nutrients usage should be conducted for specific industrial waste water streams.

Phylogenetic analysis and recombination events in full genome sequences of apple stem grooving virus

Apple stem grooving virus (ASGV) is one of the most important viral pathogens infecting pome and stone fruit trees worldwide. In this study, with the complete nucleotide sequence of isolate ASGV-T47, which we generated, molecular variation and recombination in ASGV full genomic sequences worldwide were analyzed. ASGV-T47 shared 79.7-97.6% nucleotide identity with the other isolates worldwide and had the highest identity with an isolate from Japan. Phylogenetic analysis based on whole genome clustered all 16 isolates from around the world into two groups with no correlation to host or geographical origin. Four isolates were detected to be recombinants. Selection pressure estimation indicated that the two codons at positions 1756 and 1798 are under positive selection, while purifying selection is the primary evolutionary dynamics for ASGV.

Engineering poly(lactic-co-glycolic acid)/hydroxyapatite microspheres with diverse macropores patterns and the cellular responses

Design macroporous topography on spherical substrates via a straightforward approach and investigate the corresponding cell responses.

ScatterJ: An ImageJ plugin for the evaluation of analytical microscopy datasets

We present ScatterJ, an ImageJ plugin that allows for extracting qualitative as well as quantitative information from analytical microscopy datasets. A large variety of analytical microscopy methods are used to obtain spatially resolved chemical information. The resulting datasets are often large and complex, and can contain information that is not obvious or directly accessible. ScatterJ extends and complements existing methods to extract information on correlation and colocalization from pairs of species-specific or element-specific maps. We demonstrate the possibilities to extract information using example datasets from biogeochemical studies, although the plugin is not restricted to this type of research. The information that we could extract from our existing data helped to further our understanding of biogeochemical processes such as mineral formation or heavy metal sorption. ScatterJ can be used for a variety of different two-dimensional (2D) and three-dimensional (3D) datasets such as energy-dispersive X-ray spectroscopy maps, 3D confocal laser scanning microscopy maps, and 2D scanning transmission X-ray microscopy maps.

Electrospun P34HB fibres: a scaffold for tissue engineering

OBJECTIVES

Amongst the fourth generation of PHAs is bio-plasticpoly3-hydroxybutyrate4-hydroxybutyrate (P34HB); it is thus appropriate to perform novel research on its uses and applications. The main objective of this study was to determine whether electrospun P34HB fibres would accommodate viability, growth and differentiation of mouse adipose-derived stem cells (mASCs).

MATERIALS AND METHODS

In the present study, we looked at P34HB in two forms, electrospun P34HB fibres and P34HB film. Morphology of electrospun P34HB fibres and P34HB film were characterized using scanning electron microscopy, fluorescence microscopy and confocal laser scanning microscopy, after cell seeding. Cell adhesion, proliferation and cytotoxicity tests were conducted on both by MTT and CCK-8 assays, respectively. After being cultured with osteogenic induction, expression of adipogenic genes Runx2, OPN and OCN, were examined by real-time PCR.

RESULTS

By scanning electron microscopy, light microscopy and confocal laser scanning microscopy, we observed that the mASCs grew well associated with the P34HB materials. After MTT and CCK-8 assay, we concluded that P34HB would, indeed, be a material suitable for further cell adhesion and proliferation studies. More importantly, we found that the P34HB matrices promoted expression of Runx2, OPN and OCN with osteogenic induction.

CONCLUSIONS

In this investigation, we can confirm that the electrospun P34HB fibres accommodated survival, proliferation and differentiation of mASCs, and we have been able to draw the conclusion that fibre scaffolds produced by the electrospinning process are promising for application of bone tissue engineering.

Construction of conditionally replicating adenovirus expressing staphylococcal enterotoxin A gene: potential usefulness for anti-tumor therapies

OBJECTIVE

The aim of this study was to construct a conditionally replicating adenovirus pPE3-SEA expressing staphylococcal enterotoxin A (SEA) gene.

MATERIALS AND METHODS

A full-length SEA gene fragment was cloned into pENTR12 plasmid to obtain a recombinant viral plasmid pENTR12-SEA. The pENTR12-SEA plasmid was co-transfected into HEK293 cells along with pPE3-ccdB, which encoded for the virus backbone, to generate recombinant adenovirus pPE3-SEA vector. Amplified pPE3-SEA vectors were purified, and viral titer was determined using the 50% tissue culture infective dose method.

RESULTS

The PCR, restriction enzyme digestion, and sequence analyses proved successful construction of replicating oncolytic adenovirus pENTR12-SEA and recombinant SEA expressing oncolytic adenovirus pPE3-SEA. The viral titer was 2.5 × 1010 pfu/ml.

CONCLUSIONS

We successfully constructed conditionally replicating adenovirus pPE3-SEA which can be utilized for experimental studies of tumor-targeted therapies.

3-D analysis of bacterial cell-(iron)mineral aggregates formed during Fe(II) oxidation by the nitrate-reducing Acidovorax sp. strain BoFeN1 using complementary microscopy tomography approaches

The formation of cell-(iron)mineral aggregates as a consequence of bacterial iron oxidation is an environmentally widespread process with a number of implications for processes such as sorption and coprecipitation of contaminants and nutrients. Whereas the overall appearance of such aggregates is easily accessible using 2-D microscopy techniques, the 3-D and internal structure remain obscure. In this study, we examined the 3-D structure of cell-(iron)mineral aggregates formed during Fe(II) oxidation by the nitrate-reducing Acidovorax sp. strain BoFeN1 using a combination of advanced 3-D microscopy techniques. We obtained 3-D structural and chemical information on different cellular encrustation patterns at high spatial resolution (4-200 nm, depending on the method): more specifically, (1) cells free of iron minerals, (2) periplasm filled with iron minerals, (3) spike- or platelet-shaped iron mineral structures, (4) bulky structures on the cell surface, (5) extracellular iron mineral shell structures, (6) cells with iron mineral filled cytoplasm, and (7) agglomerations of extracellular globular structures. In addition to structural information, chemical nanotomography suggests a dominant role of extracellular polymeric substances (EPS) in controlling the formation of cell-(iron)mineral aggregates. Furthermore, samples in their hydrated state showed cell-(iron)mineral aggregates in pristine conditions free of preparation (i.e., drying/dehydration) artifacts. All these results were obtained using 3-D microscopy techniques such as focused ion beam (FIB)/scanning electron microscopy (SEM) tomography, transmission electron microscopy (TEM) tomography, scanning transmission (soft) X-ray microscopy (STXM) tomography, and confocal laser scanning microscopy (CLSM). It turned out that, due to the various different contrast mechanisms of the individual approaches, and due to the required sample preparation steps, only the combination of these techniques was able to provide a comprehensive understanding of structure and composition of the various Fe-precipitates and their association with bacterial cells and EPS.

Cbl-b gene silencing in splenic T lymphocytes as a therapeutic strategy to target the prostate cancer RM-1 cell tumors in immune competent mice

OBJECTIVE

In recent years, the field of cancer immunotherapy has become a research hotspot and is currently faced with numerous challenges. The objective of this study was to assess the success of cbl-b gene silencing in splenic T lymphocytes as an immune strategy to target the murine prostate cancer RM-1 cells in vitro and solid tumors in vivo.

MATERIALS AND METHODS

For this purpose, cbl-b gene-specific siRNA was designed, synthesized, and was transfected into mouse splenic T lymphocytes, followed by assessment of T cell activation, TH1 cytokine production, and in vitro cytotoxicity against RM-1 cell targets. For in vivo cytotoxicity studies, first the RM-1 tumor model was established in immune competent mice that were later tumor-injected with splenic T lymphocytes transfected with specific shRNA for cbl-b gene silencing.

RESULTS

The data show that the cbl-b gene silencing in T lymphocytes resulted in an enhanced surface expression of CD69 activation marker, elevated production of interleukin (IL)-2 and interferon (IFN)-γ, and their increased cytotoxicity as effectors against RM-1 prostate cancer cells. The tumor injection with cbl-b shRNA-transfected T lymphocytes also resulted in significant reduction of the tumor size as compared with controls.

CONCLUSIONS

cbl-b gene silencing strategy enhanced the immune function of T lymphocytes, increased their cytotoxic potential against RM-1 prostate cancer cells, as well as caused significant suppression of the tumor growth in immune competent mice.