Epidemiological comparison of clinical manifestations according to HLA-B*27 carrier status of Chinese ankylosing spondylitis patients

The aim of the study was to investigate and compare the clinical manifestations between HLA-B27(+) and HLA-B27(-) ankylosing spondylitis (AS) patients in order to obtain knowledge of the impact of HLA-B27 status on AS, and to inform clinical treatment. A nationwide epidemiological investigation was performed from November 2008 to October 2010. The demographic data and clinical characteristics, and the status of HLA-B27 were collected using questionnaires and laboratory assay, respectively. A total of 2144 patients (78.5% males and 78.4% HLA-B27(+) AS patients) participated in this study. The percentages of males, patients with family history, and involvement of lumbar spine, thoracic spine and hip joints, were observed to be significantly higher in the HLA-B27(+) AS patients than in their HLA-B27(-) AS peers.

Levels of antioxidants in the spinal fluid after induction of anesthesia with ropivacaine

Anesthesia is a loss of sensation or consciousness and mechanisms by which drugs can produce this state are not clear. Recent studies gave insight show anesthetic agents may lead to loss of consciousness at the molecular level. The objective of this study was to determine whether ropivacaine can influence antioxidant defense system.To analyze the response of the antioxidant defense system to ropivacaine samples were taken from the vein before anesthesia (0 min) and 5 min, 15 min, and 60 min after anesthesia. Subsequently, the levels of lipid peroxidation as melaninedialdehyde (MDA) and glutathione (GSH), as well as superoxide dismutase (SOD) and catalase (CAT) activities were measured.We observed moderate increase in lipid peroxidation and glutathione levels. More-over, the activity of superoxide dismutase was slightly enhanced. These alterations occurred 5 min after spinal injection of ropivacaine and this phenomenon was maintained throughout anesthesia. We measured decreased catalase activity starting from 5 min after anesthesia and activity of this antioxidant enzyme was not recovered even after 60 min of anesthesia.We found that spinal injection of ropivacaine results in increased levels of free radicals in spinal fluid, which may stimulate antioxidant defense system of spinal fluid during anesthesia.

N-glycosylation of the premembrane protein of Japanese encephalitis virus is critical for folding of the envelope protein and assembly of virus-like particles

Premembrane (prM) and envelope (E) proteins, the major structural proteins of Japanese encephalitis virus (JEV) each contain single potential N-glycosylation site. In this study, the role of N-glycosylation of these proteins on their folding and activity were investigated. Three mutant prM and/or E (prM-E) genes lacking N-glycosylation sites were generated by site-directed mutagenesis. The effects of the N-glycan on folding, secretion and cytotoxicity of mutant proteins were determined by comparison with their wild type (wt) counterparts. Removal of N-glycan from the prM protein resulted in a complete misfolding of the E protein and failure to form virus-like particles (VLPs). A similar removal of N-glycan from the E protein led to a low efficiency of its folding and VLPs formation. The secretion and cytotoxicity of the E protein was also markedly impaired in case the glycosylation sites in the prM or E or both proteins were removed. These results suggest that the N-glycosylation of the prM protein is critical to the folding of the E protein, which makes it pivotal in the cytotoxicity of JEV particles and their production.

Photoprotection in the green tidal alga Ulva prolifera: role of LHCSR and PsbS proteins in response to high light stress

Ulva prolifera, an intertidal macroalga, has to adapt to wide variations in light intensity, making this species particularly rewarding for studying the evolution of photoprotective mechanisms. Intense light induced increased non-photochemical quenching (NPQ) and stimulated de-epoxidation of xanthophyll cycle components, while DTT-treated samples had lower NPQ capacity, indicating that the xanthophyll cycle must participate in photoprotection. In this work, we found that the PsbS-related NPQ was maintained in U. prolifera. According to analysed gene expression, both LhcSR and psbS were up-regulated in high light, suggesting that these two genes are light-induced. LHCSR and PsbS proteins were present at different light intensities and accumulated under high light conditions, and PsbS concentrations were higher than LHCSR, showing that the NPQ mechanism of U. prolifera is more dependent on PsbS protein concentration. Moreover, the level of both LHCSR and PsbS proteins was high even in the darkness, and neither the transcript level nor protein content of LhcSR and psbS genes varied significantly following short-term exposure to intense light. These findings suggest that this alga can modulate NPQ levels through regulation of the xanthophyll cycle and concentrations of PsbS and/or LHCSR.

Ketamine used as an acesodyne in human breast cancer therapy causes an undesirable side effect, upregulating anti-apoptosis protein Bcl-2 expression

Ketamine is a dissociative anesthetic agent that has been widely used in surgery and for relieving pain in chronic cancer patients. We applied ketamine to breast cancer cell line MDA-MB-231 to detect the effect of treatment and molecular mechanisms involved. We found that ketamine can upregulate the level of anti-apoptosis protein Bcl-2, which promotes breast cancer cell invasion and proliferation. Knockdown of Bcl-2 could inhibit the increase of Bcl-2 and reduce the invasion and proliferation caused by ketamine in human breast cancer cells. Our findings provide new insight into the effects of ketamine in cancer treatment; we suggest that ketamine, which has been widely used in cancer operations and for relieving pain in chronic cancer patients, may be not the best choice because it can worsen the cancer through promotion of anti-apoptosis.

Advanced three-dimensional electron microscopy techniques in the quest for better structural and functional materials

After a short review of electron tomography techniques for materials science, this overview will cover some recent results on different shape memory and nanostructured metallic systems obtained by various three-dimensional (3D) electron imaging techniques. In binary Ni-Ti, the 3D morphology and distribution of Ni₄Ti₃ precipitates are investigated by using FIB/SEM slice-and-view yielding 3D data stacks. Different quantification techniques will be presented including the principal ellipsoid for a given precipitate, shape classification following a Zingg scheme, particle distribution function, distance transform and water penetration. The latter is a novel approach to quantifying the expected matrix transformation in between the precipitates. The different samples investigated include a single crystal annealed with and without compression yielding layered and autocatalytic precipitation, respectively, and a polycrystal revealing different densities and sizes of the precipitates resulting in a multistage transformation process. Electron tomography was used to understand the interaction between focused ion beam-induced Frank loops and long dislocation structures in nanobeams of Al exhibiting special mechanical behaviour measured by on-chip deposition. Atomic resolution electron tomography is demonstrated on Ag nanoparticles in an Al matrix.

Genetic diversity of Phytophthora capsici (Pythiaceae) isolates in Anhui Province of China based on ISSR-PCR markers

Phytophthora capsici is a plant pathogenic oomycete that damages numerous crops worldwide. Consequently, interest in research on the genetic structure of this species has grown in recent decades. However, there is little information about P. capsici in eastern China. We investigated the genetic diversity of P. capsici isolates from three large regions of Anhui Province in eastern China based on ISSR-PCR technology. Thirteen random primers were screened and used to amplify DNA from 51 samples. We obtained 158 reproducible ISSR fragments, of which 90% were polymorphic, revealing a high degree of polymorphism among the isolates. Genetic similarity coefficients among all the isolates ranged from 0.56 to 0.94, with a mean of 0.84 based on the ISSR data, indicating a high level of genetic variation in these P. capsici isolates. Cluster analysis using UPGMA indicated that the Anhui isolates were divided into seven groups according to the DNA fingerprints, although there was no correlation between the ISSR group and geographic origin. Isolates from the same location showed no clustering based on the year of sampling. AMOVA partitioned variability among (13.6%) and within populations (86.4%). The gene flow among populations ranged from 2.804 to 4.937, with a mean of 3.545, indicating highly frequent gene exchange. Genetic distances and genetic differentiation were negatively correlated with geographic distances. These results lead us to suggest that this pathogen has considerable evolutionary potential, which will enable it to adapt to and overcome management strategies over time.

Basic anatomy and tumor biology of the RPS6KA6 gene that encodes the p90 ribosomal S6 kinase-4

The RPS6KA6 gene encodes the p90 ribosomal S6 kinase-4 (RSK4) that is still largely uncharacterized. In this study we identified a new RSK4 transcription initiation site and several alternative splice sites with a 5’RACE approach. The resulting mRNA variants encompass four possible first start codons. The first 15 nucleotides (nt) of exon 22 in mouse and the penultimate exon in both human (exon 21) and mouse (exon 24) RSK4 underwent alternative splicing, although the penultimate exon deleted variant appeared mainly in cell clines, but not in most normal tissues. Demethylation agent 5-azacytidine inhibited the deletion of the penultimate exon whereas two indolocarbazole-derived inhibitors of cyclin dependent kinase 4 or 6 induced deletion of the first 39 nt from exon 21 of human RSK4. In all human cancer cell lines studied, the 90-kD wild type RSK4 was sparse but, surprisingly, several isoforms at or smaller than 72-kD were expressed as detected by seven different antibodies. On immunoblots, each of these smaller isoforms often appeared as a duplet or triplet and the levels of these isoforms varied greatly among different cell lines and culture conditions. Cyclin D1 inhibited RSK4 expression and serum starvation enhanced the inhibition, whereas c-Myc and RSK4 inhibited cyclin D1. The effects of RSK4 on cell growth, cell death and chemoresponse depended on the mRNA variant or the protein isoform expressed, on the specificity of the cell lines, as well as on the anchorage-dependent or -independent growth conditions and the in vivo situation. Moreover, we also observed that even a given cDNA might be expressed to multiple proteins; therefore, when using a cDNA, one needs to exclude this possibility before attribution of the biological results from the cDNA to the anticipated protein. Collectively, our results suggest that whether RSK4 is oncogenic or tumor suppressive depends on many factors.

Clinical features of axial undifferentiated spondyloarthritis (USpA) in China: HLA-B27 is more useful for classification than MRI of the sacroiliac joint

OBJECTIVES

To analyse the clinical features of Chinese undifferentiated spondyloarthritis (USpA) patients with predominantly axial involvement, and in particular the influence of human leucocyte antigen (HLA)-B27 and magnetic resonance imaging (MRI) of the sacroiliac joint (SIJ) on the classification of axial USpA.

METHODS

Patients with low back pain for ≥ 3 months and no definite radiographic sacroiliitis were enrolled in this study. They were diagnosed as USpA based on rheumatologists' findings. Correlations between clinical features and HLA-B27 status or MRI manifestations were analysed.

RESULTS

A total of 197 USpA patients were recruited, of whom 135 (70.3%) were positive for HLA-B27. Acute inflammation, structural damage lesions, and normal findings on SIJ MRI were recorded in 64.5, 13.2 and 22.3% of patients, respectively. Classification criteria for axial SpA according to the European Spondylarthropathy Study Group (ESSG), Amor, and the Assessment of SpondyloArthritis International Society (ASAS) were fulfilled by 63.5, 64.5 and 83.2% patients, respectively. Cross-validation showed significant correlation among these three criteria. Patients positive for HLA-B27 included more males, with earlier onset age, better response to non-steroidal anti-inflammatory drugs (NSAIDs), and higher erythrocyte sedimentation rate (ESR)/C-reactive protein (CRP) levels. In addition, more HLA-B27-positive than HLA-B27-negative patients fulfilled the ESSG, Amor, and ASAS criteria. Patients with acute inflammation on SIJ MRI had a higher level of ESR/CRP, and a greater proportion of them fulfilled the Amor and ASAS criteria. However, the proportion of those fulfilling the ESSG criteria did not differ with different MRI manifestations.

CONCLUSION

Both HLA-B27 status and SIJ MRI findings influence the classification of Chinese axial USpA patients, but HLA-B27 seems of more value.

Effect of Ambient Gas Pressure on Pulsed Laser Ablation Plume Dynamics and Znte Film Growth

Epitaxial thin films of nitrogen-doped p-ZnTe were grown on single-crystal, semi-insulating GaAs substrates via pulsed laser ablation of a stoichiometric ZnTe target. Both low pressure nitrogen ambients and high vacuum were used. Results of in situ reflection high energy electron diffraction (RHEED) and time-resolved ion probe measurements have been compared with ex situ Hall effect and transmission electron microscopy (TEM) measurements. A strong correlation was observed between the nature of the film's surface during growth (2-D vs. 3-D, assessed via RHEED) and the ambient gas pressures employed during deposition. The extended defect content (assessed via cross-sectional TEM) in the region >150 nm from the film/substrate interface was found to increase with the ambient gas pressure during deposition, which could not be explained by lattice mismatch alone. At sufficiently high pressures, misoriented, columnar grains developed which were not only consistent with the RHEED observations but also were correlated with a marked decrease in Hall mobility and a slight decrease in hole concentration. Ion probe measurements, which monitored the attenuation and slowing of the ion current arriving at the substrate surface, indicated that for increasing nitrogen pressure the fast (vacuum) velocity-distribution splits into a distinct fast and two collisionally-slowed components or modes. Gas-controlled variations in these components mirrored trends in electrical properties and microstructural measurements.