Attenuation of subchondral bone abnormal changes in osteoarthritis by inhibition of SDF-1 signaling

BACKGROUND

Current conservative treatments for osteoarthritis (OA) are largely symptoms control therapies. Further understanding on the pathological mechanisms of OA is crucial for new pharmacological intervention.

OBJECTIVE

In this study, we investigated the role of Stromal cell-derived factor-1(SDF-1) in regulating subchondral bone changes during the progression of OA.

METHODS

Clinical samples of different stages of OA severity were analyzed by histology staining, micro-CT, enzyme-linked immunosorbent assay (ELISA) and western blotting, to compare SDF-1 level in subchondral bone. The effects of SDF-1 on human mesenchymal stem cells (MSCs) osteogenic differentiation were evaluated. In vivo assessment was performed in an anterior cruciate ligament transaction plus medial meniscus resection in the SD rats. The OA rats received continuous infusion of AMD3100 (SDF-1 receptor blocker) in osmotic mini-pump implanted subcutaneously for 6 weeks. These rats were then terminated and subjected to the same in vitro assessments as human OA samples.

RESULTS

SDF-1 level was significantly elevated in the subchondral bone of human OA samples. In the cell studies, the results showed SDF-1 plays an important role in osteogenic differentiation of MSCs. In the OA animal studies, there were less cartilage damage in the AMD3100-treated group; microCT results showed that the subchondral bone formation was significantly reduced and so did the number of positive Nestin or Osterix cells in the subchondral bone region.

CONCLUSIONS

Higher level of SDF-1 may induce the subchondral bone abnormal changes in OA and inhibition of SDF-1 signaling could be a potential therapeutic approach for OA.

Stem cell therapy for enhancement of bone consolidation in distraction osteogenesis: A contemporary review of experimental studies

Objectives

Distraction osteogenesis (DO) mobilises bone regenerative potential and avoids the complications of other treatments such as bone graft. The major disadvantage of DO is the length of time required for bone consolidation. Mesenchymal stem cells (MSCs) have been used to promote bone formation with some good results.

Methods

We hereby review the published literature on the use of MSCs in promoting bone consolidation during DO.

Results

Studies differed in animal type (mice, rabbit, dog, sheep), bone type (femur, tibia, skull), DO protocols and cell transplantation methods.

Conclusion

The majority of studies reported that the transplantation of MSCs enhanced bone consolidation or formation in DO. Many questions relating to animal model, DO protocol and cell transplantation regime remain to be further investigated. Clinical trials are needed to test and confirm these findings from animal studies.

Cite this article: Y. Yang, S. Lin, B. Wang, W. Gu, G. Li. Stem cell therapy for enhancement of bone consolidation in distraction osteogenesis: A contemporary review of experimental studies. Bone Joint Res 2017;6:385–390. DOI: 10.1302/2046-3758.66.BJR-2017-0023.

Critical behavior in tetragonal antiperovskite GeNFe3 with a frustrated ferromagnetic state

Tetragonal GeNFe₃ has a second-order ferromagnetic (FM) to paramagnetic transition at 76 K. Our integrated investigations indicate that the ground FM state is frustrated and the tetragonal symmetry is retained below 550 K based on the results of variable temperature X-ray diffraction. Critical behavior was analyzed by a systematic bulk magnetization study. The estimated critical exponents by three different methods (modified Arrott plot, the Kouvel-Fisher method, and critical isotherm analysis) conformably suggest that long-range magnetic coupling described by mean-field (MF) theoretical model is dominant in GeNFe₃. The experimental M-T-H data collapse into two independent branches according to the scaling equations m = f_±(h) with the renormalized magnetization m = ε^-βM(H, ε) and the magnetic field h = Hε^-(β+γ). The exchange distance is estimated as J(r) ∼ r^-4.8 on the basis of the β and γ values, which lies between the long-range MF model (r^-4.5) and the short-range 3D Heisenberg (3DH) model (r^-5). Our results indicate that the competition between local magnetic moments of iron 3d electronic state and itinerant covalent interactions of N-Fe bonds should be responsible for critical behavior in this system.

Trends in diabetes and obesity in Samoa over 35 years, 1978-2013

AIMS

Population surveys of Type 2 diabetes mellitus and obesity conducted in Samoa over three decades have used varying methodologies and definitions. This study standardizes measures, and trends of Type 2 diabetes mellitus and obesity for 1978-2013 are projected to 2020 for adults aged 25-64 years.

METHODS

Unit records from eight surveys (n = 12 516) were adjusted to the previous census for Division of residence, sex and age to improve national representativeness. Type 2 diabetes mellitus is defined as a fasting plasma glucose ≥ 7.0 mmol/l and/or on medication. Obesity is defined as BMI ≥ 30 kg/m² . Random effects meta-regression was employed to assess time trends following logit transformation. Poisson regression from strata was used to assess the effects of mean BMI changes on Type 2 diabetes mellitus period trends.

RESULTS

Over 1978-2013, Type 2 diabetes mellitus prevalence increased from 1.2% to 19.6% in men (2.3% per 5 years), and from 2.2% to 19.5% in women (2.2% per 5 years). Obesity prevalence increased from 27.7% to 53.1% in men (3.6% per 5 years) and from 44.4% to 76.7% (4.5% per 5 years) in women. Type 2 diabetes mellitus and obesity prevalences increased in all age groups. From period trends, Type 2 diabetes mellitus prevalence in 2020 is projected to be 26% in men and women. Projected obesity prevalence is projected to be 59% in men and 81% in women. Type 2 diabetes mellitus period trends attributable to BMI increase are estimated as 31% (men) and 16% (women), after adjusting for age.

CONCLUSION

This is the first study to produce trends of Type 2 diabetes mellitus and obesity in Samoa based on standardized data from population surveys. Type 2 diabetes mellitus is equally prevalent in both sexes, and obesity is widespread. Type 2 diabetes mellitus prevalence in Samoa is likely to continue to increase in the near future.

Large Positive Thermal Expansion and Small Band Gap in Double-ReO3-Type Compound NaSbF6

Double-ReO₃-type structure compound NaSbF₆ undergoes a low-temperature rhombohedral to high-temperature cubic phase between 303 and 323 K, as revealed by temperature-dependent X-ray diffractions. Although many double-ReO₃-type fluorides exhibit either low thermal expansion or negative thermal expansion (NTE), NaSbF₆ exhibits positive thermal expansion (PTE) with a large volumetric coefficient of thermal expansion, α_v = 62 ppm/K, in its cubic phase. Raman spectroscopy reveals that the low-frequency transverse vibration of fluorine atoms is stiffened in NaSbF₆, compared with the typical NTE compound CaZrF₆ with the same structure. The related weak contraction associated with the polyhedral rocking would be overcome by the notable elongation of the Na-F bond length on heating, thus leading to the large volumetric PTE. Unlike ScF₃ and CaZrF₆ which are insulators with a wide band gap, a relative small band gap of 3.76 eV was observed in NaSbF₆. The small band gap can be attributed to the hybridization between the Sb 5s and F 2p orbitals.

Measurement of the Neutrino Mixing Angle θ_{23} in NOvA

This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of 6.05×10^{20} protons on target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal θ_{23} mixing (θ_{23}=π/4). Assuming the normal mass hierarchy, we find Δm_{32}^{2}=(2.67±0.11)×10^{-3}  eV^{2} and sin^{2}θ_{23} at the two statistically degenerate values 0.404_{-0.022}^{+0.030} and 0.624_{-0.030}^{+0.022}, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6σ significance.

Dietary supplementation with tributyrin prevented weaned pigs from growth retardation and lethal infection via modulation of inflammatory cytokines production, ileal expression, and intestinal acetate fermentation

Weanling pigs, with an underdeveloped intestine and immature immune system, are usually subjected to depressed feed intake, growth retardation, and postweaning diarrhea. The aim of this study was to determine 1) the growth response of weaned pigs to supplemental tributyrin (TB) and 2) the potential effects and mechanisms of TB in modulating immune responses of lipopolysaccharide (LPS)-challenged piglets. A total of 240 piglets (Duroc × Large White × Landrace) were weaned at 21 d of age to a control (basal diet), supplemented with antibiotics (AB; +AB), supplemented with TB (+TB), or with supplemental AB and TB (+AB+TB) diets, with 10 replicate pens (6 piglets/pen) per diet. At 49 d of age, male pigs from the control and +TB groups were intraperitoneally injected with LPS (25 μg/kg BW) or saline ( = 6) and sacrificed at 4 h after injection to collect blood, intestine, and digesta samples for biochemical analysis. There were higher ( < 0.05) feed intake and lower ( < 0.05) percentage of negative growth piglets in the +TB groups than in the control group during the first week after weaning. For piglets without LPS challenge, there were higher ( < 0.05) ileal fibroblast growth factor 19 () mRNA abundance and total bile acid concentrations in the +TB groups than in the control group, whereas downregulated ( < 0.05) expression was observed in the +TB groups after LPS challenge. Lipopolysaccharide challenge in the control group increased ( < 0.05) plasma tumor necrosis factor α and IL-6 concentrations and colonic amount and decreased ( < 0.05) colonic goblet cells and colonic and cecal acetate concentrations, with no differences ( > 0.05) observed between +TB groups following LPS challenge. Taken together, dietary supplementation with TB prevented growth retardation through stimulating the appetite of weaned pigs and protected piglets against lethal infection via modulation of inflammatory cytokines production, ileal expression, and intestinal acetate fermentation.

Correction: The nanotipped hairs of gecko skin and biotemplated replicas impair and/or kill pathogenic bacteria with high efficiency

Correction for 'The nanotipped hairs of gecko skin and biotemplated replicas impair and/or kill pathogenic bacteria with high efficiency' by X. Li, et al., Nanoscale, 2016, 8, 18860-18869.

Quantum phase transition induced by real-space topology

A quantum phase transition (QPT), including both topological and symmetry breaking types, is usually induced by the change of global parameters, such as external fields or global coupling constants. In this work, we demonstrate the existence of QPT induced by the real-space topology of the system. We investigate the groundstate properties of the tight-binding model on a honeycomb lattice with the torus geometry based on exact results. It is shown that the ground state experiences a second-order QPT, exhibiting the scaling behavior, when the torus switches to a tube, which reveals the connection between quantum phase and the real-space topology of the system.

The nanotipped hairs of gecko skin and biotemplated replicas impair and/or kill pathogenic bacteria with high efficiency

We show that gecko microspinules (hairs) and their equivalent replicas, bearing nanoscale tips, can kill or impair surface associating oral pathogenic bacteria with high efficiency even after 7 days of repeated attacks. Scanning Electron Microscopy suggests that there is more than one mechanism contributing to cell death which appears to be related to the scaling of the bacteria type with the hair arrays and accessibility to the underlying nano-topography of the hierarchical surfaces.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Comparison of different hypotensive anaesthesia techniques in orthognathic surgery with regard to intraoperative blood loss, quality of the surgical field, and postoperative nausea and vomiting

Sixty-three consecutive patients undergoing bimaxillary surgery between June and August 2015 were included in this study. Twenty-one patients were included in each of three study groups. In group 1, sevoflurane was the sole maintenance anaesthesia agent used; in group 2, propofol was the predominant agent, in addition to a reduced amount of sevoflurane; in group 3, patients received sevoflurane until fixation was completed, at which point it was switched to propofol. The mean intraoperative blood loss (ml) was 707.14±290.74 in group 1, 917.62±380.30 in group 2, and 750.00±331.84 in group 3; the difference between groups 1 and 2 was significant (P=0.047). The mean score for the quality of surgical field assessment was 1.32±0.44 in group 1, 2.04±0.49 in group 2, and 1.45±0.53 in group 3 (P=0.003). The postoperative nausea and vomiting (PONV) rate was 28.6% in group 1, 9.5% in group 2, and 14.3% in group 3 (P=0.343). The quality of the surgical field was significantly better in groups 1 and 3 than in group 2. The average blood loss in group 1 was also significantly less than in group 2. The PONV rates were lower than those reported in other studies.

Limits on Active to Sterile Neutrino Oscillations from Disappearance Searches in the MINOS, Daya Bay, and Bugey-3 Experiments

Searches for a light sterile neutrino have been performed independently by the MINOS and the Daya Bay experiments using the muon (anti)neutrino and electron antineutrino disappearance channels, respectively. In this Letter, results from both experiments are combined with those from the Bugey-3 reactor neutrino experiment to constrain oscillations into light sterile neutrinos. The three experiments are sensitive to complementary regions of parameter space, enabling the combined analysis to probe regions allowed by the Liquid Scintillator Neutrino Detector (LSND) and MiniBooNE experiments in a minimally extended four-neutrino flavor framework. Stringent limits on sin^{2}2θ_{μe} are set over 6 orders of magnitude in the sterile mass-squared splitting Δm_{41}^{2}. The sterile-neutrino mixing phase space allowed by the LSND and MiniBooNE experiments is excluded for Δm_{41}^{2}<0.8  eV^{2} at 95%  CL_{s}.

Improved Search for a Light Sterile Neutrino with the Full Configuration of the Daya Bay Experiment

This Letter reports an improved search for light sterile neutrino mixing in the electron antineutrino disappearance channel with the full configuration of the Daya Bay Reactor Neutrino Experiment. With an additional 404 days of data collected in eight antineutrino detectors, this search benefits from 3.6 times the statistics available to the previous publication, as well as from improvements in energy calibration and background reduction. A relative comparison of the rate and energy spectrum of reactor antineutrinos in the three experimental halls yields no evidence of sterile neutrino mixing in the 2×10^{-4}≲|Δm_{41}^{2}|≲0.3  eV^{2} mass range. The resulting limits on sin^{2}2θ_{14} are improved by approx imately a factor of 2 over previous results and constitute the most stringent constraints to date in the |Δm_{41}^{2}|≲0.2  eV^{2} region.

Magnetic-flux-driven topological quantum phase transition and manipulation of perfect edge states in graphene tube

We study the tight-binding model for a graphene tube with perimeter N threaded by a magnetic field. We show exactly that this model has different nontrivial topological phases as the flux changes. The winding number, as an indicator of topological quantum phase transition (QPT) fixes at N/3 if N/3 equals to its integer part [N/3], otherwise it jumps between [N/3] and [N/3] + 1 periodically as the flux varies a flux quantum. For an open tube with zigzag boundary condition, exact edge states are obtained. There exist two perfect midgap edge states, in which the particle is completely located at the boundary, even for a tube with finite length. The threading flux can be employed to control the quantum states: transferring the perfect edge state from one end to the other, or generating maximal entanglement between them.

Breastfeeding modifies the effects of environment tobacco smoke exposure on respiratory diseases and symptoms in Chinese children: the Seven Northeast Cities Study

To evaluate the potential effect of interaction between breastfeeding and environmental tobacco smoke (ETS) exposure on respiratory health, we studied 31 049 children (aged 2-14 years) from 25 districts of seven cities in northeast China. Parents of the children completed standardized questionnaires that characterized the children's histories of respiratory symptoms and illness, feeding methods, ETS exposure, and other associated risk factors. Breastfeeding was defined as having been mainly breastfed for 3 months or more. The results showed that the association of ETS exposure with childhood respiratory conditions/diseases was modified by breastfeeding, and the association for nonbreastfed children was stronger than that for breastfed children. In particular, for nonbreastfed children, the odds ratios (ORs) for the effect of current ETS exposure asthma was 1.71 (95% CI: 1.43-2.05); however, the OR for breastfed children was 1.33 (95% CI: 1.20-1.48), indicating that the interactions between breastfeeding and current ETS exposure on asthma were statistically significant (P = 0.019). When stratified by school (kindergarten vs. elementary school), breastfeeding was more protective for asthma-related symptoms among children from kindergarten. In conclusion, this study shows that breastfeeding is associated with smaller associations between ETS exposure and respiratory conditions in children, suggesting that breastfeeding reduces susceptibility to the respiratory effects of ETS.

Eiger-induced cell death relies on Rac1-dependent endocytosis

Signaling via tumor necrosis factor receptor (TNFR) superfamily members regulates cellular life and death decisions. A subset of mammalian TNFR proteins, most notably the p75 neurotrophin receptor (p75NTR), induces cell death through a pathway that requires activation of c-Jun N-terminal kinases (JNKs). However the receptor-proximal signaling events that mediate this remain unclear. Drosophila express a single tumor necrosis factor (TNF) ligand termed Eiger (Egr) that activates JNK-dependent cell death. We have exploited this model to identify phylogenetically conserved signaling events that allow Egr to induce JNK activation and cell death in vivo. Here we report that Rac1, a small GTPase, is specifically required in Egr-mediated cell death. rac1 loss of function blocks Egr-induced cell death, whereas Rac1 overexpression enhances Egr-induced killing. We identify Vav as a GEF for Rac1 in this pathway and demonstrate that dLRRK functions as a negative regulator of Rac1 that normally acts to constrain Egr-induced death. Thus dLRRK loss of function increases Egr-induced cell death in the fly. We further show that Rac1-dependent entry of Egr into early endosomes is a crucial prerequisite for JNK activation and for cell death and show that this entry requires the activity of Rab21 and Rab7. These findings reveal novel regulatory mechanisms that allow Rac1 to contribute to Egr-induced JNK activation and cell death.

Chemical approaches to angiogenesis in development and regeneration

Vascular endothelial cells are essential building blocks of angiogenesis, which is required for normal embryonic development and tissue regeneration. In this chapter, we describe how to use transgenic zebrafish embryos expressing vascular-specific green fluorescent protein to evaluate differentiation, growth, and morphogenesis of endothelial cells. When combined with instrument automation and computational analysis, this method allows high-throughput screening for biologically active small chemical molecules that are effective in promoting angiogenesis. These molecules can be validated in mammalian endothelial cell differentiation and proliferation assays. These studies provide new reagents and therapeutic candidates for regenerative medicine studies.

Chitosan-gelatin-based microgel for sustained drug delivery

We describe here the proof-of-concept of synthesizing microgels via cross-linking of chitosan and gelatin with succinimide-end polyethylene glycol (PEG). The introduction of PEG provided thermo-responsiveness to microgels, and the size of microgels significantly changed with increasing temperature. Furthermore, the microgel was biocompatible as confirmed in vitro by MTT assay with NIH 3T3 fibroblast and degradable. Chitosan-based microgels exhibited strong affinity to hydrophobic drug and prolonged release of folic acid was observed at physiological temperature with varying pH. The proposed cost-effective injectable microgels have the potential to serve as the delivery vehicle of hydrophobic bioactive molecules.

Intranasal insulin protects against substantia nigra dopaminergic neuronal loss and alleviates motor deficits induced by 6-OHDA in rats

Protection of substantia nigra (SN) dopaminergic (DA) neurons by neurotrophic factors (NTFs) is one of the promising strategies in Parkinson's disease (PD) therapy. A major clinical challenge for NTF-based therapy is that NTFs need to be delivered into the brain via invasive means, which often shows limited delivery efficiency. The nose to brain pathway is a non-invasive brain drug delivery approach developed in recent years. Of particular interest is the finding that intranasal insulin improves cognitive functions in Alzheimer's patients. In vitro, insulin has been shown to protect neurons against various insults. Therefore, the current study was designed to test whether intranasal insulin could afford neuroprotection in the 6-hydroxydopamine (6-OHDA)-based rat PD model. 6-OHDA was injected into the right side of striatum to induce a progressive DA neuronal lesion in the ipsilateral SN pars compact (SNc). Recombinant human insulin was applied intranasally to rats starting from 24h post lesion, once per day, for 2 weeks. A battery of motor behavioral tests was conducted on day 8 and 15. The number of DA neurons in the SNc was estimated by stereological counting. Our results showed that 6-OHDA injection led to significant motor deficits and 53% of DA neuron loss in the ipsilateral side of injection. Treatment with insulin significantly ameliorated 6-OHDA-induced motor impairments, as shown by improved locomotor activity, tapered/ledged beam-walking performance, vibrissa-elicited forelimb-placing, initial steps, as well as methamphetamine-induced rotational behavior. Consistent with behavioral improvements, insulin treatment provided a potent protection of DA neurons in the SNc against 6-OHDA neurotoxicity, as shown by a 74.8% increase in tyrosine hydroxylase (TH)-positive neurons compared to the vehicle group. Intranasal insulin treatment did not affect body weight and blood glucose levels. In conclusion, our study showed that intranasal insulin provided strong neuroprotection in the 6-OHDA rat PD model, suggesting that insulin signaling may be a novel therapeutic target in broad neurodegenerative disorders.

Anomalous Hall effect in tetragonal antiperovskite GeNFe3 with a frustrated ferromagnetic state

We report observed anomalous Hall effect (AHE) behavior in the antiperovskite compound GeNFe₃ with a tetragonal symmetry.

Characterization of the nuclear localization signals of duck circovirus replication proteins

Duck circovirus (DuCV) possess a circular, single-stranded DNA genome that requires the replication protein (Rep) for its replication. Based on the viral genotype, there are two categories of Rep proteins: Rep1 and Rep2. To characterize the nuclear localization signals (NLSs) conferring the nuclear localization of the Rep proteins, defined coding regions of the rep gene of two genotypes of DuCV were cloned and co-expressed with the red fluorescent protein DsRed2. The results showed that deleting the putative N-terminal NLS located at amino acid residues 10-37 of Rep1 and Rep2 abrogated nuclear translocation, while deleting the putative C-terminal NLS located at residues 244-274 of Rep1 did not significantly alter its subcellular localization, confirming that only the NLS located at residues 10-37 in the N-termini of the Rep proteins had nuclear targeting activity.

UBASH3B/Sts-1-CBL axis regulates myeloid proliferation in human preleukemia induced by AML1-ETO

The t(8;21) rearrangement, which creates the AML1-ETO fusion protein, represents the most common chromosomal translocation in acute myeloid leukemia (AML). Clinical data suggest that CBL mutations are a frequent event in t(8;21) AML, but the role of CBL in AML1-ETO-induced leukemia has not been investigated. In this study, we demonstrate that CBL mutations collaborate with AML1-ETO to expand human CD34+ cells both in vitro and in a xenograft model. CBL depletion by shRNA also promotes the growth of AML1-ETO cells, demonstrating the inhibitory function of endogenous CBL in t(8;21) AML. Mechanistically, loss of CBL function confers hyper-responsiveness to thrombopoietin and enhances STAT5/AKT/ERK/Src signaling in AML1-ETO cells. Interestingly, we found the protein tyrosine phosphatase UBASH3B/Sts-1, which is known to inhibit CBL function, is upregulated by AML1-ETO through transcriptional and miR-9-mediated regulation. UBASH3B/Sts-1 depletion induces an aberrant pattern of CBL phosphorylation and impairs proliferation in AML1-ETO cells. The growth inhibition caused by UBASH3B/Sts-1 depletion can be rescued by ectopic expression of CBL mutants, suggesting that UBASH3B/Sts-1 supports the growth of AML1-ETO cells partly through modulation of CBL function. Our study reveals a role of CBL in restricting myeloid proliferation of human AML1-ETO-induced leukemia, and identifies UBASH3B/Sts-1 as a potential target for pharmaceutical intervention.

Graphite Carbon-Supported Mo2C Nanocomposites by a Single-Step Solid State Reaction for Electrochemical Oxygen Reduction

Novel graphite-molybdenum carbide nanocomposites (G-Mo₂C) are synthesized by a typical solid state reaction with melamine and MoO₃ as precursors under inert atmosphere. The characterization results indicate that G-Mo₂C composites are composed of high crystallization and purity of Mo₂C and few layers of graphite carbon. Mo₂C nanoparticles with sizes ranging from 5 to 50 nm are uniformly supported by surrounding graphite layers. It is believed that Mo atom resulting from the reduction of MoO₃ is beneficial to the immobilization of graphite carbon. Moreover, the electrocatalytic performances of G-Mo₂C for ORR in alkaline medium are investigated by cyclic voltammetry (CV), rotating disk electrode (RDE) and chronoamperometry test with 3M methanol. The results show that G-Mo₂C has a considerable catalytic activity and superior methanol tolerance performance for the oxygen reduction reaction (ORR) benefiting from the chemical interaction between the carbide nanoparticles and graphite carbon.

Building-related health symptoms and classroom indoor air quality: a survey of school teachers in New York State

Most previous research on indoor environments and health has studied school children or occupants in non-school settings. This investigation assessed building-related health symptoms and classroom characteristics via telephone survey of New York State school teachers. Participants were asked about 14 building-related symptoms and 23 classroom characteristics potentially related to poor indoor air quality (IAQ). Poisson regression analysis was used to assess the relationship between these symptoms and each classroom characteristic, controlling for potential confounders. About 500 teachers completed the survey. The most frequently reported classroom characteristics included open shelving (70.7%), food eaten in class (65.5%), dust (59.1%), and carpeting (46.9%). The most commonly reported symptoms included sinus problems (16.8%), headache (15.0%), allergies/congestion (14.8%), and throat irritation (14.6%). Experiencing one or more symptoms was associated most strongly with reported dust (relative risk (RR) = 3.67; 95% confidence interval (CI): 2.62-5.13), dust reservoirs (RR = 2.13; 95% CI: 1.72-2.65), paint odors (RR = 1.73; 95% CI: 1.40-2.13), mold (RR = 1.71; 95% CI: 1.39-2.11), and moldy odors (RR = 1.65 95% CI: 1.30-2.10). Stronger associations were found with increasing numbers of reported IAQ-related classroom characteristics. Similar results were found with having any building-related allergic/respiratory symptom. This research adds to the body of evidence underscoring the importance to occupant health of school IAQ.

PRACTICAL IMPLICATIONS

Teachers play an important role in educating children, and teacher well-being is important to this role. Health symptoms among New York teachers while at work are common and appear to be associated with numerous characteristics related to poor classroom IAQ. Improving school Indoor Air Quality may reduce sickness and absenteeism and improve teacher performance.

Replication timing regulation in adults with chromosomal balance rearrangements

The alternative forms of the alleles in biallelic genes display a synchronous pattern of replication that is different from genes subjected to monoallelic expression, which exhibit an asynchronous mode of replication. The present study sought to gain insight into changes in the allele-specific replication timing in phenotypically normal humans with balanced chromosomal rearrangements, and to investigate the potential mechanism for chromosomal rearrangements. We used fluorescence in situ hybridization and chose biallelic gene expression of RB1 and monoallelic expression of SNRPN in phytohemagglutinin-stimulated lymphocytes to compare differences in the allelic replication timing. We found that compared to genetically normal adult controls, adults with a normal phenotype despite chromosomal rearrangements showed normal replication timing (synchronous or asynchronous) for the RB1 gene and SNRPN genes. Our data support a link between chromosomal aberrations and epigenetic stability in phenotypically normal humans, independent of the breakpoints in chromosomal structural disruption, and represent an epigenetic mark for allelic exclusion in balanced chromosomal rearrangements in patients with normal phenotypes.

Anatomical and histomorphometric observations on the transfer of the anterior interosseous nerve to the deep branch of the ulnar nerve

This study focuses on the anatomical and histomorphometric features of the transfer of the anterior interosseous nerve to the deep motor branch of the ulnar nerve. The transfer was carried out in 15 cadaver specimens and is described using relevant anatomical landmarks. Nerve samples of donor and target nerves were histomorphometrically analysed and compared. The superficial and the deep ulnar branches had to be separated from each other for a length of 67 mm (SD 12; range 50-85) to reach the site of coaptation. We identified a suitable site for coaptation lying proximal to the pronator quadratus muscle, 202 mm (SD 15; range 185-230) distal to the medial epicondyle of the humerus. The features of the anterior interosseous nerve included a smaller nerve diameter, smaller cross-sectional area of fascicles, fewer fascicles and axons, but a similar axon density. The histomorphometric inferiority of the anterior interosseous nerve raises a question about whether it should be transferred only to selected parts of the deep motor branch of the ulnar nerve.Level III.

Novel VN/C nanocomposites as methanol-tolerant oxygen reduction electrocatalyst in alkaline electrolyte

A novel VN/C nanostructure consisting of VN nanoparticles and graphite-dominant carbon layers is synthesized by nitridation of V₂O₅ using melamine as reductant under inert atmosphere. High crystalline VN nanoparticles are observed to be uniformly distributed in carbon layers with an average size of ca13.45 nm. Moreover, the electrocatalytic performance of VN/C towards oxygen reduction reaction (ORR) in alkaline electrolyte is fascinating. The results show that VN/C has a considerable ORR activity, including a 75 percent value of the diffusion-limited current density and a 0.11 V smaller value about the onset potential with respect to Pt/C catalyst. Moreover, the excellent methanol-tolerance performance of VN/C has also been verified with 3 M methanol. Combined with the competitive prices, this VN/C nanocomposite can serve as an appropriate non-precious methanol-tolerant ORR catalyst for alkaline fuel cells.

Thoracic cord compression due to ligamentum flavum gouty tophus: a case report and literature review

Study design:

Here we describe a patient who developed myelopathy due to gouty tophi of the ligamentum flavum in the thoracic spine. We also review similar cases previously reported in the literature.

Objective:

Our aim was to present a case of myelopathy due to thoracic spinal gouty tophus.

Methods:

We report the case of a 56-year-old male with history of peripheral gout and renal insufficiency. The patient complained of back pain and paraparesis of the left lower limb. Multiple tophi were noted over several interphalangeal and metatarsophalangeal joints. Neurological examination showed decreased left lower limb strength and a positive Babinski sign. Magnetic resonance imaging of the thoracic spine revealed hypertrophy of the ligamentum flavum at the level of T3/T4, T5/T6, T9/T10, T10/T11 and T11/T12.

Results:

A thoracic laminectomy at T1-T5 was performed. Chalky white granular material was found in the ligamentum flavum during surgery. Histological analysis of the specimen demonstrated a gouty tophus. The patient's back pain and paraparesis of the lower left limb improved.

Conclusion:

The clinician should include spinal gout in the differential diagnosis when dealing with patients with gout and axial pain with or without neurologic deficits. If this diagnosis is seriously entertained, then a CT scan or magnetic resonance imaging as well as tissue biopsy may be needed to establish the diagnosis.