Nonreciprocal Magnons and Symmetry-Breaking in the Noncentrosymmetric Antiferromagnet

Inelastic neutron scattering measurements were performed to study spin dynamics in the noncentrosymmetric antiferromagnet α-Cu_{2}V_{2}O_{7}. For the first time, nonreciprocal magnons were experimentally measured in an antiferromagnet. These nonreciprocal magnons are caused by the incompatibility between anisotropic exchange and antisymmetric Dzyaloshinskii-Moriya interactions, which arise from broken symmetry, resulting in a collinear ordered state but helical spin dynamics. The nonreciprocity introduces the difference in the phase velocity of the counterrotating modes, causing the opposite spontaneous magnonic Faraday rotation of the left- and right-propagating spin waves. The breaking of spatial inversion and time reversal symmetry is revealed as a magnetic-field-induced asymmetric energy shift, which provides a test for the detailed balance relation.

Field induced spontaneous quasiparticle decay and renormalization of quasiparticle dispersion in a quantum antiferromagnet

The notion of a quasiparticle, such as a phonon, a roton or a magnon, is used in modern condensed matter physics to describe an elementary collective excitation. The intrinsic zero-temperature magnon damping in quantum spin systems can be driven by the interaction of the one-magnon states and multi-magnon continuum. However, detailed experimental studies on this quantum many-body effect induced by an applied magnetic field are rare. Here we present a high-resolution neutron scattering study in high fields on an S=1/2 antiferromagnet C₉H₁₈N₂CuBr₄. Compared with the non-interacting linear spin–wave theory, our results demonstrate a variety of phenomena including field-induced renormalization of one-magnon dispersion, spontaneous magnon decay observed via intrinsic linewidth broadening, unusual non-Lorentzian two-peak structure in the excitation spectra and a dramatic shift of spectral weight from one-magnon state to the two-magnon continuum.

Spontaneous magnon decay in canted antiferromagnets has been theoretically investigated extensively, but experimental evidence is limited. Here the authors study the spin ½ antiferromagnet DLCB via neutron scattering, revealing field-induced spontaneous magnon decay associated with three-magnon interactions.

TLR3 preconditioning enhances the therapeutic efficacy of umbilical cord mesenchymal stem cells in TNBS-induced colitis via the TLR3-Jagged-1-Notch-1 pathway

Toll-like receptor-3 (TLR3) priming may enhance mesenchymal stem cell (MSC) immunosuppressive activity, but this mechanism has not been investigated in the context of inflammatory bowel disease. Thus, we assessed the immunosuppressive properties of TLR3-primed MSCs using a trinitrobenzene sulfonate (TNBS)-induced mouse model of colitis. Intraperitoneally injected polyribocytidylic acid (poly (I:C)- (a ligand of TLR3) primed human umbilical cord-derived MSCs (hUC-MSCs) migrated to the inflamed colon and effectively improved clinical and pathological manifestations in colitic mice compared with mice treated with unstimulated hUC-MSCs (UCMs). Poly (I:C)-MSCs decreased a wide range of inflammatory cytokines and increased systemic interleukin-10 (IL-10) levels in colonic tissues. Poly (I:C)-MSCs also impaired T-helper type 1/17 (Th1/17) cell expansion and enhanced the suppressive effects of regulatory T cells (Treg) in vitro and in vivo. Poly (I:C)-MSCs suppressed the proliferation of activated mesenteric lymph node (MLN) cells via the overproduction of prostaglandin E₂ (PGE₂) and upregulation of Jagged-1. PGE₂ produced by hUC-MSCs in response to poly (I:C) increased the production of IL-10 and promoted the differentiation of Treg, which could be reversed by inhibition of Notch-1. Collectively, preconditioning MSCs with poly (I:C) enhanced the therapeutic effects of hUC-MSCs in TNBS-induced colitis, and TLR3-activated Notch-1 signaling regulated the immune suppression of hUC-MSCs through the production of PGE₂.

Tamsulosin for treatment of lower urinary tract symptoms in women: a systematic review and meta-analysis

Tamsulosin has been used for the off-label treatment of lower urinary tract symptoms (LUTS) in women. Over the past few years, several randomized controlled trials (RCTs) have reported the clinical effectiveness and safety of tamsulosin for LUTS in women. Therefore, the aim of the present study was to perform a meta-analysis to evaluate the safety and efficacy of tamsulosin in treating LUTS in women, which may resolve some of the current controversies over use of the drug and provide more reliable evidence for the use of tamsulosin. A literature review was performed to identify all published RCTs of tamsulosin for the treatment of LUTS in women. The search included the following databases: PUBMED, EMBASE, the Cochrane Controlled Trail Register of Controlled Trials, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Chinese Science and Technique Journals Database (VIP) and Wanfang Database. A systematic review and meta-analysis were conducted. Six RCTs studies involving 764 female participants were included in the analysis. Four out of the six RCTs compared tamsulosin with placebo, one RCT compared tamsulosin with prazosin and the other study compared tamsulosin with tamsulosin combined with tolterodine. Two RCTs evaluated total International Prostate Symptom Score (IPSS) and improved total IPSS compared with the placebo (standardized mean difference=-4.08, 95% confidence interval=-5.93 to -2.23, P<0.00001). IPSS (storage symptom score), IPSS (voiding symptom score) and quality-of-life score also showed the similar effects. In addition, tamsulosin improved the Overactive Bladder Questionnaire score when compared with placebo in only one RCT. For urodynamic parameters, tamsulosin improved the average flow rate and the post-void residual volume when compared with prazosin and tolterodine combined with tamsulosin, respectively. Beyond that, the other parameters showed no significant difference between the treatment and control groups. On the basis of the present evidence, tamsulosin is an effective treatment for the relief of LUTS in women when compared with placebo. However, the safety of the tamsulosin remains unknown. Further, well-conducted trials that examine long-term outcomes are required.

Disordered Route to the Coulomb Quantum Spin Liquid: Random Transverse Fields on Spin Ice in Pr_{2}Zr_{2}O_{7}

Inelastic neutron scattering reveals a broad continuum of excitations in Pr_{2}Zr_{2}O_{7}, the temperature and magnetic field dependence of which indicate a continuous distribution of quenched transverse fields (Δ) acting on the non-Kramers Pr^{3+} crystal field ground state doublets. Spin-ice correlations are apparent within 0.2 meV of the Zeeman energy. A random phase approximation provides an excellent account of the data with a transverse field distribution ρ(Δ)∝(Δ^{2}+Γ^{2})^{-1}, where Γ=0.27(1)  meV. Established during high temperature synthesis due to an underlying structural instability, it appears disorder in Pr_{2}Zr_{2}O_{7} actually induces a quantum spin liquid.

A novel trivalent HPV 16/18/58 vaccine with anti-HPV 16 and 18 neutralizing antibody responses comparable to those induced by the Gardasil quadrivalent vaccine in rhesus macaque model

Persistent infection with human papillomavirus (HPV) is a key factor in the development of precancerous lesions and invasive cervical cancer. Prophylactic vaccines to immunize against HPV are an effective approach to reducing HPV related disease burden. In this study, we investigated the immunogenicity and dosage effect of a trivalent HPV 16/18/58 vaccine (3vHPV) produced in Escherichia coli (E.coli), with Gardasil quadrivalent vaccine (4vHPV, Merck & Co.) as a positive control. Sera collected from rhesus macaques vaccinated with three dosage formulations of 3vHPV (termed low-, mid-, and high-dosage formulations, respectively), and the 4vHPV vaccine were analyzed by both Pseudovirus-Based Neutralization Assay (PBNA) and Enzyme-Linked Immunosorbent Assay (ELISA). Strong immune responses against HPV 16/18/58 were successfully elicited, and dosage-dependence was observed, with likely occurrence of immune interference between different L1-VLP antigens. HPV 16/18 specific neutralizing antibody (nAb) and total immunoglobulin G (IgG) antibody responses in rhesus macaques receiving 3vHPV at the three dosages tested were generally non-inferior to those observed in rhesus macaques receiving 4vHPV throughout the study period. Particularly, HPV 18 nAb titers induced by the mid-dosage formulation that contained the same amounts of HPV 16/18 L1-VLPs as Gardasil 4vHPV were between 7.3 to 12.7-fold higher compared to the positive control arm from weeks 24-64. The durability of antibody responses specific to HPV 16/18 elicited by 3vHPV vaccines was also shown to be non-inferior to that associated with Gardasil 4vHPV.

Evaluation of impact of anti-idursulfase antibodies during long-term idursulfase enzyme replacement therapy in mucopolysaccharidosis II patients

OBJECTIVES

This 109-week, nonrandomized, observational study of mucopolysaccharidosis II (MPS II) patients already enrolled in the Hunter Outcome Survey (HOS) (NCT00882921), assessed the long-term immunogenicity of idursulfase, and examined the effect of idursulfase-specific antibody generation on treatment safety (via infusion-related adverse events [IRAEs]) and pharmacodynamics (via urinary glycosaminoglycans [uGAGs]).

METHODS

Male patients ≥ 5 years, enrolled in HOS regardless of idursulfase treatment status were eligible. Blood/urine samples for anti-idursulfase antibody testing and uGAG measurement were collected every 12 weeks.

RESULTS

Due to difficulties in enrolling treatment-naïve patients, data collection was limited to 26 enrolled patients of 100 planned patients (aged 5.1-35.5 years) all of whom were non-naïve to treatment. Fifteen (58%) patients completed the study. There were 11/26 (42%) seropositive patients at baseline (Ab +), and 2/26 (8%) others developed intermittent seropositivity by Week 13. A total of 9/26 patients (35%) had ≥ 1 sample positive for neutralizing antibodies. Baseline uGAG levels were low due to prior idursulfase treatment and did not change appreciably thereafter. Ab + patients had persistently higher uGAG levels at entry and throughout the study than Ab - patients. Nine of 26 (34%) patients reported IRAEs. Ab + patients appeared to have a higher risk of developing IRAEs than Ab - patients. However, the relative risk was not statistically significant and decreased after adjustment for age.

CONCLUSIONS

50% of study patients developed idursulfase antibodies. Notably Ab + patients had persistently higher average uGAG levels. A clear association between IRAEs and antibodies was not established.

Coronal imbalance in degenerative lumbar scoliosis: Prevalence and influence on surgical decision-making for spinal osteotomy

AIMS

There is a paucity of information on the pre-operative coronal imbalance in patients with degenerative lumbar scoliosis (DLS) and its influence on surgical outcomes.

PATIENTS AND METHODS

A total of 284 DLS patients were recruited into this study, among whom 69 patients were treated surgically and the remaining 215 patients conservatively Patients were classified based on the coronal balance distance (CBD): Type A, CBD < 3 cm; Type B, CBD > 3 cm and C7 Plumb Line (C7PL) shifted to the concave side of the curve; Type C, CBD > 3 cm and C7PL shifted to the convex side.

RESULTS

A total of 99 of the 284 (34.8%) patient presented with a pre-operative coronal imbalance (mean CBD: 48.5, standard deviation 18.7 mm). More patients with a Type B malalignment were observed than with a Type C malalignment (62 versus 37). A total of 21 pf the 69 (30.4%) surgically treated patients had a post-operative coronal imbalance, which was found to be more prevalent in Type C patients (p < 0.001). At follow-up, less improvement was observed in terms of Short Form-36 Physical Component Score and visual analogue score for back pain (p = 0.034 and 0.025, respectively) in Type C patients.

CONCLUSION

This study shows that patients with Type C coronal malalignment may be at greater risk of post-operative coronal imbalance following posterior osteotomy. Cite this article: Bone Joint J 2016;98-B:1227-33.

Do environmental pollutants increase obesity risk in humans?

OBJECTIVES

Obesity has become a global epidemic and threat to public health. A good understanding of the causes can help attenuate the risk and spread. Environmental pollutants may have contributed to the rising global obesity rates. Some research reported associations between chemical pollutants and obesity, but findings are mixed. This study systematically examined associations between chemical pollutants and obesity in human subjects.

METHODS

Systematic review of relevant studies published between 1 January 1995 and 1 June 2016 by searching PubMed and MEDLINE®.

RESULTS

Thirty-five cross-sectional (n = 17) and cohort studies (n = 18) were identified that reported on associations between pollutants and obesity measures. Of them, 16 studies (45.71%) reported a positive association; none reported a sole inverse association; three (8.57%) reported a null association only; six (17.14%) reported both a positive and null association; seven (20.00%) reported a positive and inverse association; and three studies (8.57%) reported all associations (positive, inverse and null). Most studies examined the association between multiple different pollutants, different levels of concentration and in subsamples, which results in mixed results. Thirty-three studies reported at least one positive association between obesity and chemicals, such as polychlorinated biphenyls, biphenyl A, dichlorodiphenyltrichloroethane, dichlorodiphenyldichloroethylene and more. Certain chemicals, such as biphenyl A, were more likely to have high ORs ranging from 1.0 to 3.0, whereas highly chlorinated polychlorinated biphenyls were more likely to have negative ORs. Effects of chemicals on the endocrine system and obesity might vary by substance, exposure level, measure of adiposity and subject characteristics (e.g. sex and age).

CONCLUSIONS

Accumulated evidences show positive associations between pollutants and obesity in humans. Future large, long-term, follow-up studies are needed to assess impact of chemical pollutants on obesity risk and related mechanisms.

Influence of oral hygiene and its interaction with standard of education on the risk of oral cancer in women who neither smoked nor drank alcohol: a hospital-based, case-control study

We know of only limited data about the role of oral hygiene and the risk of oral cancer with different standards of education. The aim of this study was to assess the association between oral hygiene and risk of oral cancer, with stratification by standard of education, in Chinese women. We organised a case-control study with 250 women with oral cancer and 996 age-matched controls in Fujian, China. Data were collected by personal interview using a structured questionnaire. We used unconditional logistic regression with stratification by educational standard to estimate the odds ratios (OR) and 95% CI. Tooth-brushing twice a day or more was inversely related to the risk of oral cancer in women with high school education or above (OR 0.50; 95% CI 0.25 to 0.98), but not in those who were illiterate or had primary-middle school education. Wearing dentures showed an increased risk only in less well-educated women: the OR were 2.23 (95% CI 1.14 to 4.34) for the illiterate and 1.68 (95% CI 1.08 to 2.62) for the primary-middle school group. The loss of more than five teeth and oral ulceration were associated with increased risks of oral cancer in all three groups. There was also a multiplicative interaction between oral hygiene and standard of education for risk of oral cancer (p=0.001). Our results suggest that oral hygiene seems to have a critical role in the risk of oral cancer in Chinese women, but this effect may be modified by their educational standard.

[Dihydrotestosterone inhibits foam cell formation via a lectin-like ox-low-density lipoprotein receptor mediated mechanism in J774.1 cell line]

Objective: To investigate the effect of dihydrotestosterone (DHT) on lectin-like ox- low-density lipoprotein (LDL) receptor(LOX-1)expression and foam cell formation in the female macrophage cell line J774.1. Methods: In cultured J774.1 cells, after pretreated with DHT at concentrations of 1×10^-9 mol/L and 1×10^-8 mol/L, ox-LDL-induced LOX-1 expression and foam cell formation were investigated by quantitative real-time PCR, Western blotting, and oil-red O staining. Results: DHT at concentrations of 1×10^-9 mol/L and 1×10^-8 mol/L inhibited ox-LDL-induced LOX-1 mRNA (2.81±0.46 and 2.29±0.21 vs 4.71±0.31, both P<0.01) and protein expression (1.35±0.06 and 1.09±0.04 vs 1.75±0.11, both P<0.05). The effect was partly reversed by the androgen receptor (AR) blocker flutamide (87.6%, P=0.004). Oil-red O staining also revealed that DHT at concentrations of 1×10^-9 mol/L and 1×10^-8 mol/L suppressed ox-LDL-induced foam cell formation as quantified by the number of foam cells per high-power field (HPF) (36.0±3.0 and 29.1±1.3 vs 45.9±3.7, both P<0.05) and by the area of oil-red O stained particles per HPF (7 983±1 035 and 4 060±390 vs 14 750±2 489, both P<0.05). Conclusion: DHT at concentrations of 1×10^-9 mol/L and 1×10^-8 mol/L decreases LOX-1 expression and foam cell formation via AR.

Production of Human ATG Proteins for Lipidation Assays

Humans express several orthologs of yeast Atg8, in the LC3 and GABARAP families, which play crucial roles in autophagy through their covalent ligation to lipids, typically phosphatidylethanolamine (PE), in a process known as lipidation. Lipidation of LC3 and GABARAP regulates numerous facets of the autophagy process, including regulating expansion of the phagophore membrane, recruiting selected cargoes for degradation, and providing an autophagosome membrane-bound platform mediating dynamic interactions with other regulatory proteins. LC3 and GABARAP are families of related ubiquitin-like proteins (UBLs) (referred to here collectively as LC3/GABARAP), and their lipidation involves a divergent UBL conjugation cascade including ATG7, ATG3, and ATG12~ATG5-ATG16L1 acting as E1, E2, and E3 enzymes, respectively. ATG7 initiates LC3/GABARAP conjugation by catalyzing their C-terminal adenylation and conjugation to the catalytic cysteine of ATG3. Ultimately, the ATG12~ATG5-ATG16L1 complex catalyzes LC3/GABARAP ligation to a primary amino group on PE or other acceptor lipids. This chapter describes methods for expressing and purifying human LC3 or GABARAP, ATG7, ATG3, and the ATG12~ATG5-ATG16L1 complex for in vitro studies of LC3/GABARAP lipidation.

Crystallographic Characterization of ATG Proteins and Their Interacting Partners

Autophagosome formation and specific substrate recruitment during autophagy require ligation of the ubiquitin-like protein (UBL) Atg8 to the head group of the lipid phosphatidylethanolamine. Atg8 lipidation is mediated by distinctive UBL cascades involving autophagy-specific E1, E2, and E3 enzymes that differ substantially in sequence from components of other UBL conjugation cascades. Structural studies are important for elucidating the roles of Atg proteins that regulate multiple steps involved in autophagy. This chapter describes methods to prepare and crystallize selected proteins and complexes involved in autophagy UBL conjugation pathways, as a guide for strategies for structural and biochemical characterization of Atg proteins.

The First Report of a Fully Sequenced Resistance Plasmid from Shigella boydii

The purpose of this study was to characterize mechanisms of plasmid-mediated antimicrobial resistance in Shigella boydii. S. boydii strain 2246 with resistance to ciprofloxacin, ceftriaxone and azithromycin was isolated from a human case of watery diarrhea in a Chinese public hospital. Resistance in strain 2246 to ceftriaxone and azithromycin was attributable to the presence of bla_CTX-M-14, and erm(B) and mph(A), respectively, which were co-located on a multidrug-resistant (MDR) plasmid p2246-CTXM. p2246-CTXM represented a novel IncFII-type MDR plasmid with a very complex chimera structure. Its master backbone was genetically closely related to the R100 plasmid, but p2246-CTXM had evolved to integrate additional R100-unrelated backbone regions as well as massive exogenous mobile elements that carried multiple resistance determinants. In p2246-CTXM, erm(B) together with its leading peptide gene erm(C), mph(A) together with its regulatory genes mrx and mphR(A), and bla_CTX-M-14 were captured by three different mobile elements Tn6295, the IS26-mph(A)-mrx-mphR(A)-IS6100 unit, and a truncated ISEcp1-bla_CTX-M-14-IS903D-iroN transposition unit, respectively, all of which were harbored in a large Tn3-family transposon Tn6285. p2246-CTXM still carried additional resistance determinants mer (mercury resistance), aacA4 (aminoglycoside resistance), cmlA1 (chloramphenicol resistance), and qacED1 (quaternary ammonium compound resistance). This is the first report of identifying a clinical S. boydii strain simultaneously resistant to ciprofloxacin, ceftriaxone, and azithromycin, and determining the complete sequence of a resistance plasmid from S. boydii.

Aerosol synthesis of phase-controlled iron-graphene nanohybrids through FeOOH nanorod intermediates

Iron-based nanoparticles form the basis for a host of sustainable alternative technologies based on this earth-abundant, low-toxicity element that can adopt a variety of oxidation states, crystal phases, and functions. Control of size, shape, and phase stability is a challenge for many nano-iron-based technologies, especially those involving Fe0 that is susceptible to oxidation under ambient conditions. This article presents a continuous method for hybridizing Fe-based nanoparticles with carbon in the form of graphene-encapsulated Fe-based particles with core-shell symmetry that allows flexible control of iron particle size, shape, and phase stability. The method uses FeOOH nanorods and graphene oxide as precursors, and subjects them to an aerosol-phase microdroplet drying and annealing process to yield a range of Fe/C nanohybrids whose structure can be controlled through adjustment of aerosol process temperature and post-synthesis thermal treatment conditions. We demonstrate that FeOOH nanorods can be successfully encapsulated in graphene, and transform during annealing into encapsulated Fe3O4 or Fe0 nanoparticles by reductive fragmentation, where the graphene nanosack acts as a carbothermic reductant. The hybrids are characterized by vibrating sample magnetometry and Cr(VI) reduction rates in aqueous media. The Fe0-graphene hybrids show high activity, good stability, and good recyclability in aqueous Cr(VI) removal due to the effect of graphene encapsulation. The present work suggests this rapid and continuous synthesis method can produce stable Fe-based materials, and can be extended to other metal systems, where graphene encapsulation can induce in situ reduction of metal oxide precursors into zero-valent metal-graphene hybrids.

microRNA-21 mediates the TGF-β1-induced migration of keratinocytes via targeting PTEN

OBJECTIVE

The aim of this study was to investigate the molecular mechanism into the keratinocyte migration, which is promoted by Transforming growth factor-β1 (TGF-β1) during wound healing.

MATERIALS AND METHODS

In the present study, we investigated the regulation by TGF-β1 on phosphatase and tensin homolog (PTEN) expression, and microRNA-21 (miR-21) level with real-time quantitative PCR or/and Western blotting, and then examined the regulatory role of miR-21 on the PTEN expression and the mesenchymal transition, with real-time quantitative PCR, western blotting and luciferase reporter assay, and the migration of keratinocytic HaCaT cells with scratch assay.

RESULTS

It was demonstrated that miR-21 was upregulated by TGF-β1 treatment in HaCaT cells; and the upregulated miR-21 targeted the 3' UTR of PTEN gene and downregulated the PTEN expression, along with the Smad3/4 upregulation. Moreover, the miR-21 manipulation with miR-21 mimics or miR-21 inhibitor not only upregulated or downregulated the miR-21 level, but also associated with the mesenchymal transition and the migration of HaCaT cells via promoting or downregulating the FSP1 and Collagen I and the E-cadherin, and via upregulating or downregulating the migration of HaCaT cells.

CONCLUSIONS

Our results demonstrate that miR-21 mediates the TGF-β1-promoted mesenchymal transition and migration of keratinocytes during skin wound healing via targeting PTEN. This study implies that miR-21 might be an important target to promote the skin wound healing.

Conversion From Calcineurin Inhibitors to Mammalian Target-of-Rapamycin Inhibitors in Heart Transplant Recipients: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Conversion from calcineurin inhibitors (CNIs) to mammalian target-of-rapamycin inhibitors (mTORi) was systematically evaluated in heart transplant recipients (HTRs) for the first time.

METHODS

MEDLINE (PUBMED), EMBASE, Cochrane Library, and clinical trial registries were searched comprehensively. After screening for eligibility, the randomized controlled trials (RCTs) comparing continuation of CNI with conversion to mTORi therapy underwent review, quality assessment, and data extraction. Outcomes analyzed including creatinine clearance, serum creatinine level, rejection, adverse effects, and triglyceride levels were expressed as mean differences (MDs) or as risk ratios (RRs) with 95% confidence intervals (CIs).

RESULTS

This is the first systematic review evaluating converting from CNI to mTORi therapy in HTRs. A total of 4 RCTs (231 HTRs, 117 vs 114) were included in our analysis. Patients converted to mTORi had a higher creatinine clearance (MD, 19.31; 95% CI [11.16, 27.46]; P < .00001) and lower serum creatinine levels (MD, -0.15; 95% CI [-0.25, -0.05]; P = .002). Patients converted to mTORi had a significantly higher occurrence of adverse effects, which included skin diseases, gastrointestinal side effects, bone marrow suppression, and infections. There was no significant difference between the 2 groups regarding graft rejection and triglyceride levels (RR, 2.61; 95% CI [0.08, 81.25]; P = .58; MD, 22.89; 95% CI [-21.86, 67.63]; P = .32).

CONCLUSIONS

Conversion from CNI to mTORi therapy may improve the renal function in HTRs, but the patients may suffer from a high incidence of mTORi-associated adverse events. Therefore, conversion to mTORi must be carefully assessed for the benefits and risks.

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.

[A novel self-growing rod technique for early onset scoliosis: an experimental study based on a porcine scoliosis model]

OBJECTIVE

To evaluate the efficacy of a growth-guidance growing rod in an established porcine scoliosis model via the Cobb angle correction and the continued spinal growth.

METHODS

Immature pigs (age: 6 weeks old, weight: 6-8 kg) were instrumented and tethered using a three separate incisions fashion.After considerable scoliosis was induced, the pigs were randomly assigned to an experiment group (EG) and a sham group (SG). In EG, the growing rod was implanted and the pigs were euthanized 8 weeks postoperatively; while in SG, the whole instrumentations were only removed and the pigs were followed up over a 8-week period.Dorsoventral (DV) X-ray radiographs were taken prior to and immediately after the growing rod implanting surgery, and at 4-week intervals to assess the Cobb angle orrection and instrumentation positioning.The continued spinal growth and the rod sliding were also assessed from the radiographs.

RESULTS

Of the 16 pigs, one pig encountered infection during the inducement of the experimental scoliosis and thus was excluded from analysis.Of the remaining 15 pigs, all animals developed progressive, structural scoliosis.The 15 pigs were randomized into EG(n=10) and SG(n=5). Two pigs in EG encountered infection and were also excluded from analysis.Of the remaining 8 pigs in EG, no neurologic complications, implant failure or infection were observed.In EG, the Cobb angle of the scoliosis before the growing rod implanted was (52.1 ±14.1)° and it decreased to (25.4±15.2)° postoperatively.After 8 weeks, the Cobb angle was (20.2±11.4)°.In SG, the Cobb angle of the scoliosis after 8-week tethering period was (55.2±15.7)° and it decreased to (53.6±15.8)° after removal of the tethering.The curvature remained stable (51.2°) during the subsequent 8 weeks.During the 8-16th week, the spinal height increased 14.2 cm and radiographic analysis of the growing rod sliding revealed an average distraction of 39.8 mm in EG; while in SG, the increased spinal height was 14.9 cm.The difference of the increased spinal height between EG and SG was not significant (P=0.821).

CONCLUSION

The novel growing rod system can provide substantial correction of deformity, and additionally, allow for continually spinal growth without significant growing disturbance.

Ultrathin lensed fiber-optic probe for optical coherence tomography

We investigated and validated a novel method to develop ultrathin lensed fiber-optic (LFO) probes for optical coherence tomography (OCT) imaging. We made the LFO probe by attaching a segment of no core fiber (NCF) to the distal end of a single mode fiber (SMF) and generating a curved surface at the tip of the NCF using the electric arc of a fusion splicer. The novel fabrication approach enabled us to control the length of the NCF and the radius of the fiber lens independently. By strategically choosing these two parameters, the LFO probe could achieve a broad range of working distance and depth of focus for different OCT applications. A probe with 125μm diameter and lateral resolution up to 10μm was demonstrated. The low-cost, disposable and robust LFO probe is expected to have great potential for interstitial OCT imaging.

Sagittal alignment of the spine-pelvis-lower extremity axis in patients with severe knee osteoarthritis: A radiographic study

Objectives

Normal sagittal spine-pelvis-lower extremity alignment is crucial in humans for maintaining an ergonomic upright standing posture, and pathogenesis in any segment leads to poor balance. The present study aimed to investigate how this sagittal alignment can be affected by severe knee osteoarthritis (KOA), and whether associated changes corresponded with symptoms of lower back pain (LBP) in this patient population.

Methods

Lateral radiograph films in an upright standing position were obtained from 59 patients with severe KOA and 58 asymptomatic controls free from KOA. Sagittal alignment of the spine, pelvis, hip and proximal femur was quantified by measuring several radiographic parameters. Global balance was accessed according to the relative position of the C7 plumb line to the sacrum and femoral heads. The presence of chronic LBP was documented. Comparisons between the two groups were carried by independent samples t-tests or chi-squared test.

Results

Patients with severe KOA showed significant backward femoral inclination (FI), hip flexion, forward spinal inclination, and higher prevalence of global imbalance (27.1% versus 3.4%, p < 0.001) compared with controls. In addition, patients with FI of 10° (n = 23) showed reduced lumbar lordosis and significant forward spinal inclination compared with controls, whereas those with FI > 10° (n = 36) presented with significant pelvic anteversion and hip flexion. A total of 39 patients with KOA (66.1%) suffered from LBP. There was no significant difference in sagittal alignment between KOA patients with and without LBP.

Conclusions

The sagittal alignment of spine-pelvis-lower extremity axis was significantly influenced by severe KOA. The lumbar spine served as the primary source of compensation, while hip flexion and pelvic anteversion increased for further compensation. Changes in sagittal alignment may not be involved in the pathogenesis of LBP in this patient population.

Cite this article: W. J. Wang, F. Liu, Y.W. Zhu, M.H. Sun, Y. Qiu, W. J. Weng. Sagittal alignment of the spine-pelvis-lower extremity axis in patients with severe knee osteoarthritis: A radiographic study. Bone Joint Res 2016;5:198–205. DOI:10.1302/2046-3758.55.2000538.

Deletion of the Small RNA Chaperone Protein Hfq down Regulates Genes Related to Virulence and Confers Protection against Wild-Type Brucella Challenge in Mice

Brucellosis is one of the most common zoonotic epidemics worldwide. Brucella, the etiological pathogen of brucellosis, has unique virulence characteristics, including the ability to survive within the host cell. Hfq is a bacterial chaperone protein that is involved in the survival of the pathogen under stress conditions. Moreover, hfq affects the expression of a large number of target genes. In the present study, we characterized the expression and regulatory patterns of the target genes of Hfq during brucellosis. The results revealed that hfq expression is highly induced in macrophages at the early infection stage and at the late stage of mouse infection. Several genes related to virulence, including omp25, omp31, vjbR, htrA, gntR, and dnaK, were found to be regulated by hfq during infection in BALB/c mice. Gene expression and cytokine secretion analysis revealed that an hfq-deletion mutant induced different cytokine profiles compared with that induced by 16M. Infection with the hfq-deletion mutant induced protective immune responses against 16M challenge. Together, these results suggest that hfq is induced during infection and its deletion results in significant attenuation which affects the host immune response caused by Brucella infection. By regulating genes related to virulence, hfq promotes the virulence of Brucella. The unique characteristics of the hfq-deletion mutant, including its decreased virulence and the ability to induce protective immune response upon infection, suggest that it represents an attractive candidate for the design of a live attenuated vaccine against Brucella.

New pathways for improved quantification of energy-dispersive X-ray spectra of semiconductors with multiple X-ray lines from thin foils investigated in transmission electron microscopy

Theoretical approaches to quantify the chemical composition of bulk and thin-layer specimens using energy-dispersive X-ray spectroscopy in a transmission electron microscope are compared to experiments investigating (In)GaAs and Si(Ge) semiconductors. Absorption correctors can be improved by varying the take-off angle to determine the depth of features within the foil or the samples thickness, or by definition of effective k-factors that can be obtained from plots of k-factors versus foil thickness or, preferably, versus the K/L intensity ratio for a suitable element. The latter procedure yields plots of self-consistent absorption corrections that can be used to determine the chemical composition, iteratively for SiGe using a set of calibration curves or directly from a single calibration curve for InGaAs, for single X-ray spectra without knowledge of sample thickness, density or mass absorption coefficients.

One Dimensional(1D)-to-2D Crossover of Spin Correlations in the 3D Magnet ZnMn2O4

We report on the intriguing evolution of the dynamical spin correlations of the frustrated spinel ZnMn₂O₄. Inelastic neutron scattering and magnetization studies reveal that the dynamical correlations at high temperatures are 1D. At lower temperature, these dynamical correlations become 2D. Surprisingly, the dynamical correlations condense into a quasi 2D Ising-like ordered state, making this a rare observation of two dimensional order on the spinel lattice. Remarkably, 3D ordering is not observed down to temperatures as low as 300 mK. This unprecedented dimensional crossover stems from frustrated exchange couplings due to the huge Jahn-Teller distortions around Mn³⁺ ions on the spinel lattice.

Disproportionate growth between the spine and pelvis in patients with thoracic adolescent scoliosis

A self-control ratio, the spine-pelvis index (SPI), was proposed for the assessment of patients with adolescent idiopathic scoliosis (AIS) in this study. The aim was to evaluate the disproportionate growth between the spine and pelvis in these patients using SPI. A total of 64 female patients with thoracic AIS were randomly enrolled between December 2010 and October 2012 (mean age 13 years, standard deviation (sd) 2.17; 9 to 18) and a further 73 healthy female patients with a mean age of 12.4 years (mean age 12.4 years, sd 2.24; 9 to 18), were randomly selected from a normal control database at our centre. The radiographic parameters measured included length of spine (LOS), height of spine (HOS), length of thoracic vertebrae (LOT), height of thoracic vertebrae (HOT), width of pelvis (WOP), height of pelvis (HOP) and width of thorax (WOT). SPI was defined as the ratio LOS/HOP. The SPI and LOT/HOP in patients with AIS showed a significant increase when compared with normal girls (p < 0.001 and p < 0.001 respectively), implying an abnormal pattern of growth of the spine relative to the pelvis in patients with AIS.

No significant difference in SPI was found in different age groups in the control group, making the SPI an age-independent parameter with a mean value of 2.219 (2.164 to 2.239). We also found that the SPI was not related to maturity in the control group.

This study, for the first time, used a self-control ratio to confirm the disproportionate patterns of growth of the spine and pelvis in patients with thoracic AIS, highlighting that the SPI is not affected by age or maturity.

Cite this article: Bone Joint J 2015;97-B:1668–74.

Analysis of Factors Affecting the Length of Hospital Stay for Patients with Diabetes

OBJECTIVE

The sharp rise in health expenditure of diabetes has become a huge financial and medical burden. A retrospective study was conducted to investigate the length of hospitalization for patients with diabetes and the control methods of the length of hospitalization, so as to improve the social and economic benefits of the hospital.

METHODS

Data of patients with diabetes who were admitted in the Guangdong Shantou Central Hospital from 2011 to 2013 were collected. Descriptive statistics and logistic regression analysis were used to explore the factors influencing the length of hospitalization for patients with diabetes such as sociological factors, disease factors, and clinical factors.

RESULTS

Univariate analysis results indicated that there were factors influencing the length of hospitalization for patients with diabetes, which were as follows: sociological factors including age (P<0.001), occupation (P=0.001), payment method (P<0.001), and the number of hospitalizations (P<0.001); disease factors including comorbidity (P<0.001) and initial glycated hemoglobin levels (P<0.001); and clinical factors including hospital-acquired infection (P<0.001), surgery (P<0.001), diagnoses within 3 days (P<0.001), department transfers (P=0.007), and treatment efficacy (P=0.003). In logistic regression analysis, 7 factors including surgery, hospital-acquired infections, comorbidities, age, payment methods, number of hospitalizations, and treatment efficacy had significant impacts on the length hospitalization for patients with diabetes.

CONCLUSION

The results of this study will be provided as a reference for a reasonable length of hospitalization of patients with diabetes.

Immunization with individual proteins of the Lrp/AsnC family induces protection against Brucella melitensis 16M challenges in mice

Brucellosis is one of the most common zoonoses worldwide. Subunit vaccines are promising for the prevention of human brucellosis. In our previous protective antigen screening studies, we identified a new protective antigen, BMEI0357, which belongs to the Lrp/asnC protein family, a conserved transcriptional regulator in bacteria that is absent in eukaryotes. In the present study, the Brucella genome annotation was screened and a total of six proteins were identified as members of the Lrp/AsnC family. Lrp/AsnC proteins have two domains that are conserved among the family members. However, sequence similarities between these proteins ranged from 9 to 50%, indicating high sequence heterogeneity. To test whether proteins of this family have similar characteristics, all six proteins were cloned and expressed in Escherichia coli. The recombinant proteins were purified and their protective efficacy was evaluated in BALB/c mice challenged with Brucella melitensis 16M. The results show that all six Lrp/AsnC proteins could induce a protective immune response against Brucella melitensis 16M. Antibodies against the Lrp/AsnC proteins were detected in the immunized mice. However, levels of antibodies against these proteins were relatively variable in human brucellosis sera. Taken together, our results show that these six proteins of the Lrp/AsnC family in Brucella could induce protective immune responses in mice.

Comparison of virulence between the Yersinia pestis Microtus 201, an avirulent strain to humans, and the vaccine strain EV in rhesus macaques, Macaca mulatta

Our previous study has demonstrated that Yersinia pestis Microtus 201 is a low virulent strain to the Chinese-origin rhesus macaques, Macaca mulatta, and can protect it against high dose of virulent Y. pestis challenge by subcutaneous route. To investigate whether the Y. pestis Microtus 201 can be used as a live attenuated vaccine candidate, in this study its intravenous virulence was determined and compared with the live attenuated vaccine strain EV in the Chinese-origin rhesus macaque model. The results showed that the Chinese-origin rhesus macaques can survive intravenous infection with approximately 10(9) CFU of the Y. pestis Microtus 201, but all the animals succumbed to 10(10) CFU of intravenous infection. By contrast, all the animals survive intravenous infection with 10(10) CFU of the vaccine EV. Post-mortem examination showed multiple areas of severe abscess in the lungs of the dead animals infected with 10(10) CFU of the Y. pestis Microtus 201, whereas histopathology observation, microbiological examination and immunohistochemistry staining showed that the Y. pestis Microtus 201 also invaded hearts, livers, spleens, kidneys and lymph nodes and caused different degrees of pathological changes in these organs. These results indicated that the Y. pestis Microtus 201 is indeed low virulent to monkeys, but it is more virulent than the vaccine EV when administered by intravenous route. The Y. pestis Microtus 201 mainly attack the lungs when administered by intravenous infection, which may be the leading cause of animal death.

Progression to insulin therapy among patients with type 2 diabetes treated with sitagliptin or sulphonylurea plus metformin dual therapy

AIM

To assess time to insulin initiation among patients with type 2 diabetes mellitus (T2DM) treated with sitagliptin versus sulphonylurea as add-on to metformin.

METHODS

This retrospective cohort study used GE Centricity electronic medical records and included patients aged ≥18 years with continuous medical records and an initial prescription of sitagliptin or sulphonylurea (index date) with metformin for ≥90 days during 2006-2013. Sitagliptin and sulphonylurea users were matched 1 : 1 using propensity score matching, and differences in insulin initiation were assessed using Kaplan-Meier curves and Cox regression. We used conditional logistic regression to examine the likelihood of insulin use 1-6 years after the index date for each year.

RESULTS

Propensity score matching produced 3864 matched pairs. Kaplan-Meier analysis showed that sitagliptin users had a lower risk of insulin initiation compared with sulphonylurea users (p = 0.003), with 26.6% of sitagliptin users initiating insulin versus 34.1% of sulphonylurea users over 6 years. This finding remained significant after adjusting for baseline characteristics (hazard ratio 0.76, 95% confidence interval 0.65-0.90). Conditional logistic regression analyses confirmed that sitagliptin users were less likely to initiate insulin compared with sulphonylurea users [odds ratios for years 1-6: 0.77, 0.79, 0.81, 0.57, 0.29 and 0.75, respectively (p < 0.05 for years 4 and 5)].

CONCLUSIONS

In this real-world matched cohort study, patients with T2DM treated with sitagliptin had a significantly lower risk of insulin initiation compared with patients treated with sulphonylurea, both as add-on to metformin.

Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in ^{254}Rf

Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73) μs have been discovered in the heavy ^{254}Rf nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the K^{π}=8^{-}, ν^{2}(7/2^{+}[624],9/2^{-}[734]) two-quasineutron and the K^{π}=16^{+}, 8^{-}ν^{2}(7/2^{+}[624],9/2^{-}[734])⊗8^{-}π^{2}(7/2^{-}[514],9/2^{+}[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N=150 isotones. The four-quasiparticle isomer is longer lived than the ^{254}Rf ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1) μs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state.

Coexistence of a novel KPC-2-encoding MDR plasmid and an NDM-1-encoding pNDM-HN380-like plasmid in a clinical isolate of Citrobacter freundii

OBJECTIVES

The objective of this study was to characterize the molecular mechanism of coproduction of KPC-2 and NDM-1 in Citrobacter freundii.

METHODS

C. freundii strain 112298 was isolated from a human case of septic shock in a Chinese teaching hospital. The major carbapenemase and ESBL genes were detected by PCR. The MIC values were determined by using VITEK 2 and antimicrobial susceptibility was judged by CLSI standards. The resistance plasmid was transferred into Escherichia coli by electroporation, followed by plasmid DNA isolation from the electroporant, and then fully sequenced and compared with closely related plasmids.

RESULTS

Strain 112298 produces KPC-2 and NDM-1, encoded by the novel non-typeable plasmid p112298-KPC and an IncX3-type plasmid p112298-NDM, respectively. In p112298-KPC, a Tn1722-based blaKPC-2-carrying transposon is associated with several additional resistance modules, constituting a single MDR region. Assembly of these resistance modules is likely mediated by homologous recombination between five copies of IS26 elements at different sites within the MDR region. p112298-NDM is a very close relation of pNDM-HN380. blaNDM-1 in p112298-NDM is carried by a Tn125 variant, which differs from the prototype Tn125 as observed in pNDM-BJ01 by disruption of an upstream copy of ISAba125 by IS5 and absence of a downstream copy of ISAba125.

CONCLUSIONS

Production of KPC-2 and NDM-1 by p112298-KPC and p112298-NDM, respectively, makes C. freundii 112298 highly resistant to carbapenems and, moreover, these two plasmids still harbour genes for resistance to cephalosporins, chloramphenicol, chromate, fosfomycin, quaternary ammonium, rifampicin and sulphonamides.

Epitaxial diamond-hexagonal silicon nano-ribbon growth on (001) silicon

Silicon crystallizes in the diamond-cubic phase and shows only a weak emission at 1.1 eV. Diamond-hexagonal silicon however has an indirect bandgap at 1.5 eV and has therefore potential for application in opto-electronic devices. Here we discuss a method based on advanced silicon device processing to form diamond-hexagonal silicon nano-ribbons. With an appropriate temperature anneal applied to densify the oxide fillings between silicon fins, the lateral outward stress exerted on fins sandwiched between wide and narrow oxide windows can result in a phase transition from diamond-cubic to diamond-hexagonal Si at the base of these fins. The diamond-hexagonal slabs are generally 5-8 nm thick and can extend over the full width and length of the fins, i.e. have a nano-ribbon shape along the fins. Although hexagonal silicon is a metastable phase, once formed it is found being stable during subsequent high temperature treatments even during process steps up to 1050 ºC.

Expression and clinical value of the soluble major histocompatibility complex class I-related chain A molecule in the serum of patients with renal tumors

We investigated the expression and clinical value of the soluble major histocompatibility complex class I-related chain A (sMICA) molecule in the serum of patients with renal tumors. Sixty patients diagnosed with renal tumors were enrolled in the experimental group, whereas 20 healthy volunteers served as the control group. The sMICA levels were measured via enzyme-linked immunosorbent assay, and the results were analyzed in combination with data from pathol-ogy examination. The experimental group had a statistically significant higher sMICA level (P < 0.05) than the control group. The sMICA level was higher in patients with malignant tumors than in those with be-nign tumors. We also observed a positive relationship among different tumor-node-metastasis (TNM) pathological stages with more advanced diseases exhibiting higher sMICA levels. As a tumor-associated antigen, MICA has a close relationship with renal tumorigenesis and immune es-cape. Our results indicated that sMICA levels were related to tumor pathol-ogy, TNM stage, and metastasis. Therefore, sMICA might be a potential marker for tumor characteristics, prognosis, and recurrence prediction.