Investigation of the roles of T6SS genes in motility, biofilm formation, and extracellular protease Asp production in Vibrio alginolyticus with modified Gateway-compatible plasmids

AIMS

The aims of this study were to create and evaluate the Gateway-compatible plasmids for investigating the function of genes in Vibrio alginolyticus and other Gram-negative bacteria.

METHODS AND RESULTS

In this study, Gateway-compatible plasmids were successfully constructed for rapid and comprehensive function analysis of genes. Taking advantage of these plasmids, the in-frame deletion mutant strains and their complemented strains of five T6SS genes, including dotU1, VEPGS_0008, VEPGS_0011, hcp2 and ppkA2, were obtained. The results illustrated that all the mutant strains showed no significant effects on extracellular protease production, expression of Hcp1, and biofilm formation when compared to the wild-type strain, but in-frame deletion of VEPGS_0008 resulted in obvious biofilm reduction and the complemented strain restored to the level of the wild-type strain. Besides, in-frame deletion of dotU1, VEPGS_0008 and ppkA2 abolished the swarming ability.

CONCLUSIONS

A set of Gateway-compatible vectors for internal insertion, in-frame deletion and complementation of the target genes is constructed to facilitate the general and rapid function analysis of genes involved in T6SS in Vibrio alginolyticus.

SIGNIFICANCE AND IMPACT OF THE STUDY

The modified Gateway-compatible plasmids greatly facilitate the high-throughput and convenient function analysis of the unidentified genes.

Anti-cancer activities of tea epigallocatechin-3-gallate in breast cancer patients under radiotherapy

The purpose of this study was to test the hypothesis that administration of epigallocatechin-3-gallate (EGCG), a polyphenol present in abundance in widely consumed tea, inhibits cell proliferation, invasion, and angiogenesis in breast cancer patients. EGCG in 400 mg capsules was orally administered three times daily to breast cancer patients undergoing treatment with radiotherapy. Parameters related to cell proliferation, invasion, and angiogenesis were analyzed while blood samples were collected at different time points to determine efficacy of the EGCG treatment. Compared to patients who received radiotherapy alone, those given radiotherapy plus EGCG for an extended time period (two to eight weeks) showed significantly lower serum levels of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and reduced activation of metalloproteinase-9 and metalloproteinase-2 (MMP9/MMP2). Addition of sera obtained from patients treated with combination of radiotherapy and EGCG feeding for 2-8 weeks to in vitro cultures of highly-metastatic human MDA-MB-231 breast cancer cells resulted in the following significant changes: (1) suppression of cell proliferation and invasion; (2) arrest of cell cycles at the G0/G1 phase; (3) reduction of activation of MMP9/MMP2, expressions of Bcl-2/Bax, c-Met receptor, NF-κB, and the phosphorylation of Akt. MDA-MB-231 cells exposed to 5-10 µM EGCG also showed significant augmentation of the apoptosis inducing effects of γ-radiation, concomitant with reduced NF-κB protein level and AKT phosphorylation. These results provide hitherto unreported evidence that EGCG potentiated efficacy of radiotherapy in breast cancer patients, and raise the possibility that this tea polyphenol has potential to be a therapeutic adjuvant against human metastatic breast cancer.

Electroacupuncture inhibition of hyperalgesia in an inflammatory pain rat model: involvement of distinct spinal serotonin and norepinephrine receptor subtypes

BACKGROUND

Although acupuncture analgesia is well documented, its mechanisms have not been thoroughly clarified. We previously showed that electroacupuncture (EA) activates supraspinal serotonin- and norepinephrine-containing neurones that project to the spinal cord. This study investigates the involvement of spinal alpha(2)-adrenoceptors (α2-ARs) and 5-hydroxytryptamine (serotonin) receptors (5-HTRs) in EA effects on an inflammatory pain rat model.

METHODS

Inflammatory hyperalgesia was induced by injecting complete Freund's adjuvant (CFA, 0.08 ml) into the plantar surface of one hind paw and assessed by paw withdrawal latency (PWL) to a noxious thermal stimulus. The selective α2a-AR antagonist BRL-44408, α2b-AR antagonist imiloxan hydrochloride, 5-HT2B receptor (5-HT2BR) antagonist SB204741, 5-HT3R antagonist LY278584, or 5-HT1AR antagonists NAN-190 hydrobromide, or WAY-100635 were intrathecally administered 20 min before EA or sham EA, which was given 2 h post-CFA at acupoint GB30.

RESULTS

EA significantly increased PWL compared with sham [7.20 (0.46) vs 5.20 (0.43) s]. Pretreatment with α2a-AR [5.35 (0.45) s] or 5-HT1AR [5.22 (0.38) s] antagonists blocked EA-produced anti-hyperalgesia; α2b-AR, 5-HT2BR, and 5-HT3R antagonist pretreatment did not. Sham plus these antagonists did not significantly change PWL compared with sham plus vehicle, indicating that the antagonists had little effect on PWL. Immunohistochemical staining demonstrated that α2a-ARs are on primary afferents and 5-HT1ARs are localized in N-methyl-d-aspartic acid (NMDA) subunit NR1-containing neurones in the spinal dorsal horn.

CONCLUSIONS

The data show that α2a-ARs and 5-HT1ARs are involved in the EA inhibition of inflammatory pain and that the NMDA receptors are involved in EA action.

Imbalance of interleukin-18 and interleukin-18 binding protein in children with Henoch-Schönlein purpura

The balance between interleukin-18 (IL-18) and its endogenous antagonist, IL-18 binding protein (IL-18BP), was evaluated in children with Henoch-Schönlein purpura (HSP). Plasma IL-18 and IL-18BP levels and peripheral blood mononuclear cell IL-18 mRNA expression were significantly higher in patients with active HSP (n = 30) than in healthy controls (n = 20); IL-18BP mRNA expression was similar in active HSP and controls. Plasma levels and mRNA expression of IL-18 and IL-18BP in patients in remission (n = 19) were similar to those in controls. The ratios of IL-18 / IL-18BP plasma levels and IL-18 / IL-18BP mRNA levels in active HSP were significantly higher than in patients in remission and healthy controls. Thus, adequate IL-18BP to block the proinflammatory activity of IL-18 may not be present in active HSP and regulation of the IL-18 / IL-18BP balance might provide a potential therapeutic strategy.

Vasohibin 2 is transcriptionally activated and promotes angiogenesis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) typically relies on angiogenesis for its malignant behavior, including growth and metastasis. Vasohibin 2 (VASH2) was previously identified as an angiogenic factor, but its role in tumorigenesis is unknown. Using quantitative PCR and western blot analyses, we found that VASH2 is overexpressed in HCC cells and tissues. Using chromatin immunoprecipitation, we detected histone modifications at the putative VASH2 promoter, with increased H3K4 trimethylation and H3 acetylation and decreased H3K27 trimethylation, suggesting that epigenetic mechanisms are responsible for the deregulated VASH2 transcription in HCC. Knockdown of VASH2 via siRNA inhibited the proliferation of the hepatoma cell lines by delaying cell cycle progression and increasing apoptosis. Importantly, we found VASH2 secreted in the culture supernatant, and co-expression of its secretory chaperone small vasohibin-binding protein (SVBP) further enhanced VASH2 secretion. The supernatant from HepG2 cells expressing VASH2 enhanced the proliferation, migration and tube formation of human umbilical vein endothelial cells, and knockdown of VASH2 significantly inhibited these effects. In an in vivo study using a nude mouse model, we found that exogenous VASH2 significantly contributed to tumor growth, microvessel density and hemoglobin concentration in the tumors. Further analyses showed that the VASH2-mediated increase in the transcription of fibroblast growth factor-2, vascular endothelial growth factor and vasohibin 1 may be the mechanism underlying these effects. Taken together, these data indicate that VASH2 is abnormally expressed in HCC cells as a result of histone modifications and that VASH2 contributes to the angiogenesis in HCC via an SVBP-mediated paracrine mechanism. These results indicate a novel and important role for VASH2 in HCC angiogenesis and malignant transformation.

Vitreous surgery for macular hole-related retinal detachment after phacoemulsification cataract extraction: 10-year retrospective review

PURPOSE

To evaluate the visual and anatomical results of surgery for macular hole-related retinal detachment (MHRD) after phacoemulsification cataract extraction.

METHODS

Data for all patients who underwent surgery for MHRD after phacoemulsification cataract extraction from 1 December 1998 to 30 September 2008 in one hospital were evaluated. Patient characteristics, best-corrected visual acuity (VA) preoperatively and at last examination, surgical technique, anatomical success, and follow-up period were extracted and analysed statistically.

RESULTS

A total of 13 625 eyes of 10 076 patients who had phacoemulsification cataract surgery were included. In the follow-up period, 10 cases of MHRD in nine patients were observed, of which seven eyes had high myopia. The mean axial length was 30.97 ± 1.36 mm (29.19, 32.97) and mean myopia was-19.35 ± 1.93 (-7.5,-3.5) dioptres. Overall anatomical success was achieved in 90% (9 out of 10 eyes). There was no statistically significant difference (P=0.240) between the logarithm of the MAR VA before the phacoemulsification cataract extraction and after MHRD surgical repair. VA increased in three eyes but decreased in the other seven after MHRD surgery.

CONCLUSIONS

As a primary procedure, vitreous surgery combined with other necessary adjunct procedures such as membrane peeling and retinal tamponade seems to be successful in achieving anatomical success. However, VA improvement is dependent on the type of macular lesion and not the surgical procedure.

Directed flow of identified particles in Au+Au collisions at √[SNN]=200 GeV at RHIC

STAR's measurements of directed flow (v1) around midrapidity for π±, K±, KS0, p, and p[over ¯] in Au+Au collisions at √[sNN]=200  GeV are presented. A negative v1(y) slope is observed for most of produced particles (π±, K±, KS0, and p[over ¯]). In 5%-30% central collisions, a sizable difference is present between the v1(y) slope of protons and antiprotons, with the former being consistent with zero within errors. The v1 excitation function is presented. Comparisons to model calculations (RQMD, UrQMD, AMPT, QGSM with parton recombination, and a hydrodynamics model with a tilted source) are made. For those models which have calculations of v1 for both pions and protons, none of them can describe v1(y) for pions and protons simultaneously. The hydrodynamics model with a tilted source as currently implemented cannot explain the centrality dependence of the difference between the v1(y) slopes of protons and antiprotons.

First evidence of direct CP violation in charmless two-body decays of Bs0 mesons

Using a data sample corresponding to an integrated luminosity of 0.35  fb-1 collected by LHCb in 2011, we report the first evidence of CP violation in the decays of Bs0} mesons to K±π∓ pairs, ACP(Bs0→Kπ)=0.27±0.08(stat)±0.02(syst), with a significance of 3.3σ. Furthermore, we report the most precise measurement of CP violation in the decays of B0 mesons to K±π∓ pairs, ACP(B0→Kπ)=-0.088±0.011(stat)±0.008(syst), with a significance exceeding 6σ.

Concentrations of analyzed or reactive lysine, but not crude protein, may predict the concentration of digestible lysine in distillers dried grains with solubles fed to pigs

The objectives of this experiment were to evaluate procedures that may be used to predict the concentration of standardized ileal digestible (SID) Lys in distillers dried grains with solubles (DDGS) fed to pigs and to evaluate the accuracy of a published equation to predict SID Lys in DDGS. Twenty-one sources of DDGS were analyzed (as-fed basis) for CP (23.8% to 33.6%; CV = 8.3%), Lys (0.69% to 1.17%; CV = 12.4%), and furosine (0.02% to 0.22%; CV = 91.4%). The concentration of reactive Lys (%, as-fed basis) was calculated as analyzed Lys (%) - furosine (%) ÷ 0.32 × 0.40 and ranged from 0.47% to 1.15% (CV = 20.7%) in the 21 sources of DDGS. Twenty-one diets that each contained 60.0% of 1 source of DDGS as the sole source of CP and AA were formulated. An N-free diet was also formulated and was used to determine basal endogenous losses of CP and AA. Twenty-two barrows with an initial BW of 45.2 kg (SD = 3.1 kg) were fitted with a T-cannula in the distal ileum and allotted to a 22 × 10 Youden square design with the 22 diets and 10 periods. The SID of CP and AA were calculated for each source of DDGS. The SID of CP ranged from 69.8% to 79.6%, and the SID of Lys ranged from 45.3% to 74.1%. The concentration of SID Lys in the 21 samples of DDGS was highly related to the concentration of analyzed Lys (P < 0.001; r(2) = 0.849) and with the concentration of reactive Lys in the samples (P < 0.001; r(2) = 0.898). In contrast, the concentration of SID Lys in the 21 sources of DDGS was not related to the concentration of CP in the samples (P = 0.558; r(2) = 0.021). However, values for SID Lys were in good agreement with values predicted using a published prediction equation. In conclusion, analyzed Lys in DDGS, but not CP, may be used to predict the concentration of SID Lys in DDGS fed to pigs. However, analysis of furosine in addition to Lys and subsequent calculation of reactive Lys improve the prediction accuracy of digestible Lys concentration in DDGS.

PGE2 promotes renal carcinoma cell invasion through activated RalA

Incidence of kidney cancer is on the rise, and a better understanding of molecular mechanisms involved in the cancer invasion and metastasis is required for the development of curative therapeutics. In this study, we report that the proinflammatory cytokine prostaglandin E2 (PGE2) induces the malignant SN12C, but not benign HK2 kidney cell invasion. The PGE2 increases SN12C cell invasion through a signal pathway that encompasses EP2 and EP4, Akt, small GTPase RalA and Ral·GTP inactivator RGC2. The results support the idea that targeted interference of EP2/EP4 signal to RalA·GTP may provide benefit to patients diagnosed with advanced kidney cancer.

Magnon lifetimes on the Fe(110) surface: the role of spin-orbit coupling

We provide direct experimental evidence which demonstrates that, in the presence of a large spin-orbit coupling, the lifetime, amplitude, group, and phase velocity of the magnons propagating along two opposite (but crystallographically equivalent) directions perpendicular to the magnetization are different. A real time and space representation reveals that magnons with the same energy (eigenfrequency) propagate differently along two opposite directions. Our findings can inspire ideas for designing new spintronic devices.

Binding of carbon nanotube to BMP receptor 2 enhances cell differentiation and inhibits apoptosis via regulating bHLH transcription factors

Biomaterials that can drive stem cells to an appropriate differentiation level and decrease apoptosis of transplanted cells are needed in regenerative medicine. Nanomaterials are promising novel materials for such applications. Here we reported that carboxylated multiwalled carbon nanotube (MWCNT 1) promotes myogenic differentiation of mouse myoblast cells and inhibits cell apoptosis under the differentiation conditions by regulating basic helix-loop-helix transcription factors. MWCNT 1 attenuates bone morphogenetic protein receptor (BMPR) signaling activity by binding to BMPR2 and attenuating the phosphorylation of BMPR1. This molecular understanding allowed us to tune stem cell differentiation to various levels by chemical modifications, demonstrating human control of biological activities of nanoparticles and opening an avenue for potential applications of nanomaterials in regenerative medicine.

Reactivation of p53 by inhibiting Mdm2 E3 ligase: a novel antitumor approach

The p53 tumor suppressor has been pursued as a cancer therapeutic target based on its ability to induce cell cycle arrest and apoptosis. Reactivation of p53 in the approximately 50% of tumors that retain a functional p53 has served as potential approach in the development of cancer drug therapy. Mdm2 is a major negative regulator of p53 and has long been thought to inhibit p53 in two ways: through ubiquitination of p53, signaling for its degradation by the proteasome, and through directly binding to p53, masking its transactivation domain. Research on Mdm2 E3 function and regulation has important implications for the feasibility of targeting Mdm2 in cancer treatment. By targeting Mdm2 in cancers, especially those harboring wild-type p53, it may be possible to restore p53 function to control tumor growth. Several inhibitors for Mdm2 have been developed and have shown promise in restoring p53 function. This review will summarize the current progress of targeting Mdm2 in cancer treatment with a focus on regulating Mdm2 E3 ubiquitin ligase activity via a number of small Mdm2 binding proteins and the post-translational modification of Mdm2 itself. The potential of inhibitors of Mdm2 E3 ligase as a new novel class of anticancer drugs will also be discussed.

Mouse prostate proteome changes induced by oral pentagalloylglucose treatment suggest targets for cancer chemoprevention

Recent in vitro and in vivo preclinical studies have suggested that the Oriental herbal compound penta-1, 2, 3, 4, 6-O-galloyl-beta-D-glucose (PGG) is a promising chemopreventive agent for prostate cancer. Little is known of its safety for chronic chemoprevention use and virtually nothing is known of its in vivo responsive proteins in the target organ. Here we treated male C57BL/6 mice with daily oral administration of PGG at two dosages (1 and 2 mg per mouse) from 7 to 14 weeks of age and profiled proteomic patterns in the prostate with iTRAQ labeling and 2D LC-MS/MS analyses. While neither dose affected feed intake and body weight gain, the 2 mg dose (∼80-100 mg per kg) led to a minor but statistically significant decrease of the weight of prostate and thymus. For proteomic profiling, five prostates were pooled from each group for protein extraction. Proteins were denatured, reduced, alkylated and digested to peptides. The peptides were labeled with iTRAQ reagents, mixed and subjected to 2D LC-MS/MS analyses. PGG consumption suppressed the abundance of oncoproteins (e.g., fatty acid synthase, clusterin) and up-regulated that of tumor suppressor proteins (e.g., glutathione S-transferase M), signifying changes that may contribute to prostate cancer risk reduction.

Differential branching fraction and angular analysis of the decay B0 → K*0 μ+ μ-

The angular distributions and the partial branching fraction of the decay B0 → K*0 μ+ μ- are studied by using an integrated luminosity of 0.37  fb(-1) of data collected with the LHCb detector. The forward-backward asymmetry of the muons, A(FB), the fraction of longitudinal polarization, F(L), and the partial branching fraction dB/dq2 are determined as a function of the dimuon invariant mass. The measurements are in good agreement with the standard model predictions and are the most precise to date. In the dimuon invariant mass squared range 1.00-6.00  GeV2/c4, the results are A(FB)=-0.06(-0.14)(+0.13)±0.04, F(L)=0.55±0.10±0.03, and dB/dq2=(0.42±0.06±0.03)×10(-7)  c4/GeV2. In each case, the first error is statistical and the second systematic.

First observation of η(1405) decays into f(0)(980)π0

The decays J/ψ → γ π+ π- π0 and J/ψ → γ π0 π0 π0 are analyzed using a sample of 225×10(6) J/ψ events collected with the BESIII detector. The decay of η(1405) → f(0)(980)π0 with a large isospin violation is observed for the first time. The width of the f(0)(980) observed in the dipion mass spectra is anomalously narrower than the world average. Decay rates for three-pion decays of the η' are also measured precisely.

RLS adaptive filtering for physiological interference reduction in NIRS brain activity measurement: a Monte Carlo study

The non-invasive measurement of cerebral functional haemodynamics using near-infrared spectroscopy (NIRS) instruments is often affected by physiological interference. The suppression of this interference is crucial for reliable recovery of brain activity measurements because it can significantly affect the signal quality. In this study, we present a recursive least-squares (RLS) algorithm for adaptive filtering to reduce the magnitude of the physiological interference component. To evaluate it, we implemented Monte Carlo simulations based on a five-layer slab model of a human adult head with a multidistance source-detector arrangement, of a short pair and a long pair, for NIRS measurement. We derived measurements by adopting different interoptode distances, which is relevant to the process of optimizing the NIRS probe configuration. Both RLS and least mean squares (LMS) algorithms were used to attempt the removal of physiological interference. The results suggest that the RLS algorithm is more capable of minimizing the effect of physiological interference due to its advantages of faster convergence and smaller mean squared error (MSE). The influence of superficial layer thickness on the performance of the RLS algorithm was also investigated. We found that the near-detector position is an important variable in minimizing the MSE and a short source-detector separation less than 9 mm is robust to superficial layer thickness variation.

Response to the first wave of pandemic (H1N1) 2009: experiences and lessons learnt from China

More than 2 years after the start of pandemic H1N1, the world is fortunate that the impact, to date, has been moderate. An evaluation of the global response to the first wave of the pandemic is still ongoing. The results of an analysis of the situation in China is presented in order to gain a better understanding of the episode; to summarize the experiences in preparedness, control and mitigation of the pandemic; and to identify issues for further consideration and investigation in order to improve the response to possible next waves of the pandemic. China's response shows how a huge challenge can be transformed into an opportunity, and may offer some valuable lessons to face another wave of the pandemic or other potential public health emergencies in the future, not only for China but also for the international community.