Assessment of trabecular and cortical architecture and mechanical competence of bone by high-resolution peripheral computed tomography: comparison with transiliac bone biopsy

We compared microarchitecture and mechanical competence parameters measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) and finite-element analysis of radius and tibia to those measured by histomorphometry, micro-CT, and finite-element analysis of transiliac bone biopsies. Correlations were weak to moderate between parameters measured on biopsies and scans.

INTRODUCTION

HR-pQCT is a new imaging technique that assesses trabecular and cortical bone microarchitecture of the radius and tibia in vivo. The purpose of this study was to determine the extent to which microarchitectural variables measured by HR-pQCT reflect those measured by the "gold standard," transiliac bone biopsy.

METHODS

HR-pQCT scans (Xtreme CT, Scanco Medical AG) and iliac crest bone biopsies were performed in 54 subjects (aged 39 +/- 10 years). Biopsies were analyzed by 2D quantitative histomorphometry and 3D microcomputed tomography (microCT). Apparent Young's modulus, an estimate of mechanical competence or strength, was determined by micro-finite-element analysis (microFE) of biopsy microCT and HR-pQCT images.

RESULTS

The strongest correlations observed were between trabecular parameters (bone volume fraction, number, separation) measured by microCT of biopsies and HR-pQCT of the radius (R 0.365-0.522; P < 0.01). Cortical width of biopsies correlated with cortical thickness by HR-pQCT, but only at the tibia (R = 0.360, P < 0.01). Apparent Young's modulus calculated by microFE of biopsies correlated with that calculated for both radius (R = 0.442; P < 0.001) and tibia (R = 0.380; P < 0.001) HR-pQCT scans.

CONCLUSIONS

The associations between peripheral (HR-pQCT) and axial (transiliac biopsy) measures of microarchitecture and estimated mechanical competence are significant but modest.

Meta-analysis of robotic and laparoscopic surgery for treatment of rectal cancer

AIM: To conduct a meta-analysis to determine the relative merits of robotic surgery (RS) and laparoscopic surgery (LS) for rectal cancer.

METHODS: A literature search was performed to identify comparative studies reporting perioperative outcomes for RS and LS for rectal cancer. Pooled odds ratios and weighted mean differences (WMDs) with 95% confidence intervals (95% CIs) were calculated using either the fixed effects model or random effects model.

RESULTS: Eight studies matched the selection criteria and reported on 661 subjects, of whom 268 underwent RS and 393 underwent LS for rectal cancer. Compared the perioperative outcomes of RS with LS, reports of RS indicated favorable outcomes considering conversion (WMD: 0.25; 95% CI: 0.11-0.58; P = 0.001). Meanwhile, operative time (WMD: 27.92, 95% CI: -13.43 to 69.27; P = 0.19); blood loss (WMD: -32.35, 95% CI: -86.19 to 21.50; P = 0.24); days to passing flatus (WMD: -0.18, 95% CI: -0.96 to 0.60; P = 0.65); length of stay (WMD: -0.04; 95% CI: -2.28 to 2.20; P = 0.97); complications (WMD: 1.05; 95% CI: 0.71-1.55; P = 0.82) and pathological details, including lymph nodes harvested (WMD: 0.41, 95% CI: -0.67 to 1.50; P = 0.46), distal resection margin (WMD: -0.35, 95% CI: -1.27 to 0.58; P = 0.46), and positive circumferential resection margin (WMD: 0.54, 95% CI: 0.12-2.39; P = 0.42) were similar between RS and LS.

CONCLUSION: RS for rectal cancer is superior to LS in terms of conversion. RS may be an alternative treatment for rectal cancer. Further studies are required.

The role of miR-146a in dorsal root ganglia neurons of experimental diabetic peripheral neuropathy

Sensory neurons mediate diabetic peripheral neuropathy. Using a mouse model of diabetic peripheral neuropathy (BKS.Cg-m+/+Lepr(db)/J (db/db) mice) and cultured dorsal root ganglion (DRG) neurons, the present study showed that hyperglycemia downregulated miR-146a expression and elevated interleukin-1 receptor-activated kinase (IRAK1) and tumor necrosis factor receptor-associated factor 6 (TRAF6) levels in DRG neurons. In vitro, elevation of miR-146a by miR-146a mimics in DRG neurons increased neuronal survival under high-glucose conditions. Downregulation and elevation of miR-146a in DRG neurons, respectively, were inversely related to IRAK1 and TRAF6 levels. Treatment of diabetic peripheral neuropathy with sildenafil, a phosphodiesterase type 5 inhibitor, augmented miR-146a expression and decreased levels of IRAK1 and TRAF6 in the DRG neurons. In vitro, blockage of miR-146a in DRG neurons abolished the effect of sildenafil on DRG neuron protection and downregulation of IRAK1 and TRAF6 proteins under hyperglycemia. Our data provide the first evidence showing that miR-146a plays an important role in mediating DRG neuron apoptosis under hyperglycemic conditions.

Effects of Matrine on proliferation and differentiation in K-562 cells

We investigated the effects of Matrine on proliferation by trypan blue exclusion and differentiation by benzidine staining positive cells in K-562 cells, assayed the telomerase activity using PCR-ELISA assay, analyzed cell cycle by fluorescence-activated cell sorter analysis of the DNA content, and also determined the gene expression level of c-myc, N-ras and p53 by northern blot and dot blot analysis. The results showed that with the addition of 0.1 mg/ml Matrine, cell growth was inhibited significantly by 4 days, benizidine-positive cells rose from 1% to 2% in control cells to 15% in treated cells on day 5; treatment of K-562 cells with 0.1 mg/ml Matrine for 5 days resulted in a marked inhibition in telomerase activity, in a manner that correlated with the extent of differentiation; after exposure to Matrine for 72 h, 64.6% cells were arrested in the G1-phase of the cell cycle, the fraction of cells in S-phase had decreased from 56.9% in control cells to 24.4% in differentiated cells, and the levels of N-ras and p53 mRNA were remarkably increased for 24 and 48 h, respectively, c-myc mRNA expression level declined for 24 h and was inhibited significantly for 48 h. Our study confirmed that Matrine plays a significant effect on the inhibition of proliferation cells and inducing differentiation in K-562 cells.

Role of plasmacytoid dendritic cells and inducible costimulator-positive regulatory T cells in the immunosuppression microenvironment of gastric cancer

Regulatory T cells (Tregs) and plasmacytoid dendritic cells (pDCs) play important roles in the immune escape of cancer. In this study, we investigated pDCs and pDC-induced inducible costimulator (ICOS)(+) Treg populations in peripheral blood from gastric cancer (GC) patients and healthy donors by flow cytometry. The distribution of these cells in carcinoma tissue, peritumor tissue, and normal gastric mucosa was detected by immunohistochemistry. Plasma and tissue concentration of the cytokines such as interleukin-10 and transforming growth factor-β1 were also measured. We found that the numbers of pDCs, Tregs, and ICOS(+) Tregs in peripheral blood were increased in GC patients compared with healthy donors. In tissue, Tregs and ICOS(+) Tregs were found distributing mainly in carcinoma tissue, whereas pDCs were mainly found in peritumor tissue. Moreover, the Foxp3(+) ICOS(+) /Foxp3(+) cell ratio in carcinoma and peritumor tissue were higher than that in normal tissue. There were more ICOS(+) Tregs in tumor and peritumor tissue of late-stage GC patients. There was a positive correlation between pDCs and ICOS(+) Tregs in peripheral blood and peritumor tissue from GC patients. In conclusion, pDCs may play a potential role in recruiting ICOS(+) Tregs, and both participate in the immunosuppression microenvironment of GC.

Mucosal immunisation with papillomavirus virus-like particles elicits systemic and mucosal immunity in mice

It has been shown previously that recombinant virus-like particles (VLPs) of papillomavirus can induce VLP-specific humoral and cellular immune responses following parenteral administration. To test whether mucosal administration of bovine papillomavirus type 1 (BPV1) VLPs could produce mucosal as well as systemic immune responses to VLPs, 50 micrograms chimeric BPV1 VLPs containing an HPV16 E7 CTL epitope (BPVL1/E7 VLP) was administered intranasally to mice. After two immunisations, L1-specific serum IgG and IgA were observed. L1-specific IgG and IgA were also found in respiratory and vaginal secretions. Both serum and mucosal antibody inhibited papillomavirus VLP-induced agglutination of RBC, indicating that the antibody induced by mucosal immunisation may recognize conformational determinants associated with virus neutralisation. For comparison, VLPs were given intramuscularly, and systemic and mucosal immune responses were generally comparable following systemic or mucosal delivery. However, intranasal administration of VLP induced significantly higher local IgA response in lung, suggesting that mucosally delivered HPV VLP may be more effective for mediating local mucosal immune responses. Intranasal immunisation with HPV6b L1 VLP produced VLP-specific T proliferative responses in splenocytes, and immunisation with BPVL1 VLP containing an HPV16 E7 CTL epitope induced E7-specific CTL responses. We conclude that immunisation with papillomavirus VLPs via mucosal and intramuscular routes, without adjuvant, can elicit specific antibody at mucosal surfaces and also systemic VLP epitope specific T cell responses. These findings suggest that mucosally delivered VLPs may offer an alternative HPV VLP vaccine strategy for inducing protective humoral immunity to anogenital HPV infection, together with cell-mediated immune responses to eliminate any cells which become infected.

Serial experimental and clinical studies on the pathogenesis of multiple organ dysfunction syndrome (MODS) in severe burns

These serial clinical and experimental studies were designed to clarify the pathogenesis of postburn MODS. Both animal and clinical studies were performed. In animal experiments, 46 male cross-bred dogs were cannulated with Swan-Ganz catheters and 39 of them were inflicted with 50% TBSA third degree burns (7 were used as controls). The burned dogs were randomly divided into 4 groups: immediate infusion, delayed infusion, delayed fast infusion and delayed fast infusion combined with ginsenosides. All dogs were kept under constant barbiturate sedation during the whole study period. Hemodynamics, visceral MDA, mitochondrial respiratory control rate (RCR) and ADP/O ratio, ATP, succinic dehydrogenase (SDH), organ water content as well as light and electron microscopy of visceral tissues were determined. In the clinical study, 61 patients with extensive deep burns were chosen, of which 16 sustained MODS. Plasma TXB2/6-keto-PGF1alpha ratio, TNF, SOD, MDA, circulatory platelet aggregate ratio (CPAR), PGE2, interleukin-1, total organ water content and pathological observations of visceral tissues from patients who died of MODS were carried out. Results demonstrated that ischemic-reperfusion damage due to severe shock, sepsis and inhalation injury are three main causes of postburn death. All inflammatory mediators increased markedly in both animals and patients who sustained organ damage or MODS. SDH, RCR, ADP/O and ATP decreased significantly. These findings suggested that ischemic damage and systemic inflammatory response syndrome (SIRS) initiated by mediators or cytokines might be important in the pathogenesis of postburn MODS.

Papillomavirus virus-like particles for the delivery of multiple cytotoxic T cell epitopes

Chimeric papillomavirus (PV) virus-like particles (VLPs) based on the bovine papillomavirus type 1 (BPV-1) L1 protein were constructed by replacing the 23-carboxyl-terminal amino acids of the BPV1 major protein L1 with an artificial "polytope" minigene, containing known CTL epitopes of human PV16 E7 protein, HIV IIIB gp120 P18, Nef, and reverse transcriptase (RT) proteins, and an HPV16 E7 linear B epitope. The CTL epitopes were restricted by three different MHC class I alleles (H-2(b), H-2(d), HLA-A*0201). The chimeric L1 protein assembled into VLPs when expressed in SF-9 cells by recombinant baculovirus. After immunization of mice with polytope VLPs in the absence of adjuvant, serum antibodies were detected which reacted with both polytope VLPs and wild-type BPV1L1 VLPs, in addition to the HPV16E7 linear B cell epitope. CTL precursors specific for the HPV16 E7, HIV P18, and RT CTL epitopes were also detected in the spleen of immunized mice. Polytope VLPs can thus deliver multiple B and T epitopes as immunogens to the MHC class I and class II pathways, extending the utility of VLPs as self-adjuvanting immunogen delivery systems.

A new iterative algorithm to reconstruct the refractive index

The latest developments in x-ray imaging are associated with techniques based on the phase contrast. However, the image reconstruction procedures demand significant improvements of the traditional methods, and/or new algorithms have to be introduced to take advantage of the high contrast and sensitivity of the new experimental techniques. In this letter, an improved iterative reconstruction algorithm based on the maximum likelihood expectation maximization technique is presented and discussed in order to reconstruct the distribution of the refractive index from data collected by an analyzer-based imaging setup. The technique considered probes the partial derivative of the refractive index with respect to an axis lying in the meridional plane and perpendicular to the propagation direction. Computer simulations confirm the reliability of the proposed algorithm. In addition, the comparison between an analytical reconstruction algorithm and the iterative method has been also discussed together with the convergent characteristic of this latter algorithm. Finally, we will show how the proposed algorithm may be applied to reconstruct the distribution of the refractive index of an epoxy cylinder containing small air bubbles of about 300 micro of diameter.

Regulatory T Cells Promote Overexpression of Lgr5 on Gastric Cancer Cells via TGF-beta1 and Confer Poor Prognosis in Gastric Cancer

Background: The leucine-rich repeat containing G protein-coupled receptor 5 (Lgr5) is considered a cancer stem cell marker, and is often overexpressed in tumors. The interaction between Lgr5 and the immune-related tumor microenvironment is not completely understood. The aim of this study was to examine the role of Lgr5 in the microenvironment of gastric cancer (GC), and to explore possible immunological mechanisms influencing Lgr5 expression that are governed by regulatory T cells. Methods: Lgr5 expression was examined in 180 GC tumors by immunohistochemistry, and in 80 pairs of GC tumors for analysis of Th1/Th2 cytokines by ELISA. In addition, SGC7901 cells were co-cultured with patient-derived Tregs, varying concentrations of TGF-β1, TGF-β1 neutralizing antibody, or TGF-β receptor inhibitor SB431542, and Lgr5 and β-catenin expression were examined by qRT-PCR and western blot. Results: In this study, an immunosuppressive microenvironment was associated with high Lgr5 expression in GC. Furthermore, Lgr5 expression was up-regulated in GC cells co-cultured with Tregs or treated with exogenous TGF-β1. This up-regulation was partially inhibited by the TGF-β1 neutralizing antibody, or TGF-β1 receptor antagonist SB431542. β-catenin was up-regulated with high Lgr5 expression induced by exogenous TGF-β1, and this up-regulation was inhibited by SB431542. An increased number of Tregs and high Lgr5 expression in GC tissues were significantly associated with low overall survival. Conclusion: Tregs promoted increased Lgr5 expression in GC cells via TGF-β1 and TGF-β1 signaling pathway, which may involve activation of the Wnt signaling pathway. High Lgr5 expression via TGF-β confer poor prognosis in gastric cancer.

Changes in systolic and postsystolic wall thickening during acute coronary occlusion and reperfusion in closed-chest pigs: Implications for the assessment of regional myocardial function

The aim of the study was to characterize the impact of short-lived total coronary occlusions in closed-chest pigs on radial wall thickening within the "at-risk" myocardial segment by using gray-scale M-mode echocardiography. Twelve pigs underwent a series of 20-second total circumflex coronary artery occlusions with an angioplasty balloon. Myocardial thickening/thinning indexes were continuously monitored before ischemia, during ischemia, and on reperfusion by high-resolution M-mode recordings of the posterior wall obtained from parasternal views. The timing of regional events was compared with global systolic time intervals derived from the color Doppler myocardial imaging velocity data. Each occlusion induced a rapid decrease in end-systolic thickening (epsilon(ES)), closely paralleled by an increase in postsystolic thickening in the ischemic segment. After 20 seconds of ischemia, epsilon(ES) decreased by -86% and postsystolic thickening increased by +100%, whereas maximal thickening decreased only by -34% in comparison with preocclusion values. All wall thickening parameters returned to baseline after 15 seconds of reperfusion. During acute total ischemia in a closed-chest animal model, the changes in regional myocardial function were best characterized by the combined analysis of systolic and postsystolic thickening abnormalities and by their respective timings relative to global cardiac events markers.

The significance of changes in serum tumour necrosis factor (TNF) activity in severely burned patients

In order to explore the pathogenesis of postburn internal organ injury (OI) and multiple organ failure (MOF), serum TNF activity was measured by biological assay in 24 severely burned patients. Parameters related to internal organ functions were simultaneously measured. The results showed an obvious increase in serum TNF activity accompanied by increased serum myocardial and hepatic enzymes, plasma lactate and aggregations of WBC in internal organ tissues. Serum protein levels decreased substantially. These changes were more marked in patients suffering from both OI and MOF. It is suggested that large amounts of TNF are produced postburn and might have an important role in the development of OI and MOF.

Differentiated activities of decorin and biglycan in the progression of post-traumatic osteoarthritis

OBJECTIVE

To delineate the activities of decorin and biglycan in the progression of post-traumatic osteoarthritis (PTOA).

DESIGN

Three-month-old inducible biglycan (BgniKO) and decorin/biglycan compound (Dcn/BgniKO) knockout mice were subjected to the destabilization of the medial meniscus (DMM) surgery to induce PTOA. The OA phenotype was evaluated by assessing joint structure and sulfated glycosaminoglycan (sGAG) staining via histology, surface collagen fibril nanostructure and calcium content via scanning electron microscopy, tissue modulus via atomic force microscopy-nanoindentation, as well as subchondral bone structure and meniscus ossification via micro-computed tomography. Outcomes were compared with previous findings in the inducible decorin (DcniKO) knockout mice.

RESULTS

In the DMM model, BgniKO mice developed similar degree of OA as the control (0.44 [-0.18 1.05] difference in modified Mankin score), different from the more severe OA phenotype observed in DcniKO mice (1.38 [0.91 1.85] difference). Dcn/BgniKO mice exhibited similar histological OA phenotype as DcniKO mice (1.51 [0.97 2.04] difference vs control), including aggravated loss of sGAGs, salient surface fibrillation and formation of osteophyte. Meanwhile, Dcn/BgniKO mice showed further cartilage thinning than DcniKO mice, resulting in the exposure of underlying calcified tissues and aberrantly high surface modulus. BgniKO and Dcn/BgniKO mice developed altered subchondral trabecular bone structure in both Sham and DMM groups, while DcniKO and control mice did not.

CONCLUSION

In PTOA, decorin plays a more crucial role than biglycan in regulating cartilage degeneration, while biglycan is more important in regulating subchondral bone structure. The two have distinct activities and modest synergy in the pathogenesis of PTOA.

Association of bovine papillomavirus type 1 with microtubules

Transport of BPV-1 virus from the cell membrane to the nucleus was studied in vitro in CV-1 cells. At reduced temperature (4 degrees C), BPV-1 binding to CV-1 cells was unaffected but there was no transport of virions across the cytosol. Electron microscopy showed BPV-1 virions in association with microtubules in the cytoplasm, a finding confirmed by co-immunoprecipitation of L1 protein and tubulin. Internalization of virus was unimpaired in cells treated with the microtubule-depolymerizing drug nocodazole but virions were retained in cytoplasmic vesicles and not transported to the nucleus. We conclude that a microtubule transport mechanism in CV-1 cells moves intact BPV-1 virions from the cell surface to the nuclear membrane.

GABAA currents in immature dentate gyrus granule cells

We used whole cell patch clamp and gramicidin perforated patch recordings in hippocampal slices to study gamma-aminobutyric acid (GABA) currents in granule cells (GCs) from juvenile rat dentate gyrus (DG). GCs are generated postnatally and asynchronously such that they can be detected at different stages of their maturation in DG within the first month. In contrast, inhibitory interneurons are generated embryonically, and their circuitry is well developed even as their target GCs and GC excitatory connections are still being formed. In this study, two GABA currents evoked in GCs by medial perforant path stimulation are compared. The first, pharmacologically isolated by glutamate receptor blockade, is the product of direct activation of GABA interneurons with monosynaptic input to the recorded GC (monosynaptic GABAA). Monosynaptic GABAA displays slight outward rectification of its current-voltage relation, is 97% eliminated by 10 microM bicuculline and coincides temporally with the excitatory components of GC postsynaptic currents as has been described for GABAA currents in other brain regions. The second is a novel GABA response that is detectable in 10 microM bicuculline and is present on GCs only at the earliest stages of their maturation. Unlike monosynaptic GABAA, this transient GABA is eliminated by glutamate receptor blockade and hence is likely to be generated by interneurons activated via an intervening glutamatergic synapse (polysynaptically). It is predominantly chloride mediated, has a relative bicarbonate/chloride permeability ratio of 26%, and is unchanged by bath-applied saclofen and strychnine or by intracellular calcium chelation. It is 97% antagonized by 100 microM picrotoxin and 99% antagonized by 100 microM bicuculline. This current is thus a relatively bicuculline (BMI)-resistant GABAA current (BMIR-GABAA). Compared with monosynaptic GABAA, BMIR-GABAA has a later peak, slower time course of decay, and marked outward rectification. Its reversal potential is 7-8 mV depolarized to that of monosynaptic GABAA whether recorded in whole cell or with gramicidin perforated patch to preserve native internal chloride concentration. Together these data may suggest that BMIR-GABAA is evoked by an anatomically segregated population of interneurons activating a unique, developmentally regulated GABAA receptor. Further, the transient nature of this current coupled with its temporal characteristics that preclude overlap with the excitatory components of the synaptic response are consistent with a role that is trophic or signaling rather than primarily inhibitory.

BPV1 E2 protein enhances packaging of full-length plasmid DNA in BPV1 pseudovirions

We studied determinants of efficient encapsidation of circular DNA, incorporating a PV early region DNA sequence (nt 584-1978) previously shown to enhance packaging of DNA within papillomavirus (PV)-like particles (VLPs). Insect coelomic cells (Sf-9) and cultured monkey kidney cells (Cos-1) were transfected with an 8-kb reporter plasmid incorporating the putative BPV packaging sequence and infected with BPV1 L1 and L2 recombinant baculovirus or vaccinia virus. Heavy (1.34 g/ml) and light (1.30 g/ml) VLPs were produced, and each packaged some of the input plasmid. In light VLPs, truncated plasmids, which nevertheless incorporated the PV-derived DNA packaging sequence, were more common than full-length plasmids. Packaging efficiency of the plasmid was estimated at 1 plasmid per 10(4) VLPs in both Cos-1 and Sf-9 cells. In each cell type, expression of the BPV1 early region protein E2 in trans doubled the quantity of heavy but not light VLPs and also increased the packaging efficiency of full-length circular plasmids by threefold in heavy VLPs. The resultant pseudovirions incorporated significant amounts of E2 protein. Pseudovirions, comprising plasmids packaged within heavy VLPs, mediated the delivery of packaged plasmid into Cos-1 cells, whereby "infectivity" was blocked by antisera to BPV1 L1, but not antisera to BPV1 E4. We conclude that (a) packaging of DNA within PV L1+L2 pseudovirions is enhanced by BPV1 E2 acting in trans, (b) E2 may be packaged with the pseudovirion, and (c) E2-mediated enhancement of packaging favors 8-kb plasmid incorporation over incorporation of shorter DNA sequences.

MicroRNA-455 suppresses the oncogenic function of HDAC2 in human colorectal cancer

Colorectal cancer (CRC) is the fourth leading cause of cancer-induced mortality. Histone deacetylase 2 (HDAC2) is involved in prognosis and therapy of CRC. This study aimed to explore novel therapeutic targets for CRC. The alteration of HDAC2 expression in CRC tissues was estimated by qRT-PCR. After lentivirus transfection, HDAC2 knockdown was confirmed by western blot analysis. The effect of HDAC2 knockdown on cell proliferation was then assessed by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Screened by TargetScan, microRNA (miR)-455 was predicted to bind to 3′UTR of HDAC2 and the prediction was verified by luciferase assay. Finally, cells were transfected, respectively, with miR-455 mimics or miR-455 negative control (miR-NC) and the expression of HDAC2, cell proliferation and apoptosis of transfected cells were respectively evaluated by western blot analysis, MTT assay and flow cytometry. Results showed that the HDAC2 expression was up-regulated in CRC tissues (P<0.05). HDAC2 knockdown significantly decreased cell viability at day 3 (P<0.05), day 4 (P<0.01), and day 5 (P<0.001) after infection. Then, miR-455 was verified to directly target HDAC2, resulting in a significant difference in luciferase activity (P<0.01). Moreover, miR-455 decreased the expression of HDAC2 (P<0.01). miR-455 remarkably decreased cell viability at day 3 (P<0.05), day 4 (P<0.01), and day 5 (P<0.001) after transfection while inducing cell apoptosis (P<0.001). In conclusion, miR-455 inhibited cell proliferation while inducing cell apoptosis by targeting HDAC2 in CRC cells.

Comparison of carotid atherosclerotic plaque characteristics by high-resolution black-blood MR imaging between patients with first-time and recurrent acute ischemic stroke

BACKGROUND AND PURPOSE

It has been shown that patients with a first ischemic stroke are at high risk of developing recurrent stroke due to carotid atherosclerotic plaque rupture. However, no one has defined the difference in plaques between initial and recurrent stroke. This study sought to investigate the characteristics of carotid plaque between patients with first-time and recurrent acute ischemic stroke by using MR imaging.

MATERIALS AND METHODS

Eighty-nine patients with recent acute ischemic stroke were recruited. All subjects underwent carotid high-resolution black-blood MR imaging. The index carotid arteries, defined as the arteries responsible for the ipsilateral stroke, were analyzed quantitatively and qualitatively. Carotid plaque burden and compositional features between patients with first-time and recurrent ischemic stroke were compared.

RESULTS

Of 89 recruited patients, 51 had first-time stroke and 38 had recurrent stroke. The mean WA, WT, and PWV were greater in patients with recurrent stroke than in patients with first-time stroke (all, P < .05). Compared with patients with first-time stroke, those with recurrent stroke showed significantly higher prevalence of calcification (44.7% versus 23.5%, P = .035) as well as a larger volume of LRNC (179.14 ± 254.81 mm(2) versus 71.65 ± 111.15 mm(2), P = .027). IPH or fibrous cap rupture or both were observed in 15.8% of patients with recurrent stroke and 3.9% of patients with first-time stroke.

CONCLUSIONS

Carotid plaques in patients with recurrent ischemic stroke are significantly aggravated compared with those in patients with first-time stroke, and monitoring carotid plaques in patients with initial stroke by MR imaging may be helpful for secondary stroke prevention.

Preparation and characterization of mabs against different epitopes of CD226 (PTA1)

Recently the platelet and T-cell activation antigen 1 (PTA1) was assigned as CD226 at the 7th Conference and Workshop on Human Leukocyte Differentiation antigens (HLDA). PTA1 is mainly expressed on activated T cells, natural killer (NK) cells, platelets and stimulated endotheliocytes, and involved in the differentiation of cytotoxic T lymphocytes (CTL) and NK, as well as platelet activation and aggregation. We raised hybridomas secreting monoclonal antibodies (MAbs) to PTA1 by using the natural PTA1 as immunogen, which was purified from platelets via affinity chromatography. These MAbs, designated FMU1, FMU2, FMU3, FMU4, FMU5, FMU6 and FMU7, could recognize PTA1 cDNA transfected COS7 cells detected by flow cytometry (FCM), and also react with both natural PTA1 and PTA1/Ig fusion protein in indirect enzyme-linked immunoadsorbent assay (ELISA). The biosensor epitope mapping assay showed that the seven MAbs, together with previous PTA1-specific MAbs Leo A1 and New E1, could bind seven distinct epitopes of PTA1, respectively. The panel of MAbs might be new powerful tools to study the structure-function relationship of PTA1 molecule, and to search for the ligand of PTA1.

Unveiling the Superconducting Mechanism of Ba_{0.51}K_{0.49}BiO_{3}

The mechanism of high superconducting transition temperatures (T_{c}) in bismuthates remains under debate despite more than 30 years of extensive research. Our angle-resolved photoemission spectroscopy studies on Ba_{0.51}K_{0.49}BiO_{3} reveal an unexpectedly 34% larger bandwidth than in conventional density functional theory calculations. This can be reproduced by calculations that fully account for long-range Coulomb interactions-the first direct demonstration of bandwidth expansion due to the Fock exchange term, a long-accepted and yet uncorroborated fundamental effect in many body physics.Furthermore, we observe an isotropic superconducting gap with 2Δ_{0}/k_{B}T_{c}=3.51±0.05, and strong electron-phonon interactions with a coupling constant λ∼1.3±0.2. These findings solve a long-standing mystery-Ba_{0.51}K_{0.49}BiO_{3} is an extraordinary Bardeen-Cooper-Schrieffer superconductor, where long-range Coulomb interactions expand the bandwidth, enhance electron-phonon coupling, and generate the high T_{c}. Such effects will also be critical for finding new superconductors.

Reduced expression of serum miR-204 predicts poor prognosis of gastric cancer

Deregulation of microRNAs (miRNAs) is implicated in the initiation and progression of gastric cancer (GC). Previous studies have demonstrated that miR-204 was downregulated in GC tissues. However, its expression profile in serum samples and its potential for clinical value remain unknown. Real-time PCR was performed to evaluate the expression level of serum miR-204 in patients with GC. The association between serum miR-204 expression level and the clinical outcome of GC was then investigated. Our results showed that the expression of miR-204 in serum samples from GC patients was significantly lower than that in the healthy controls (P < 0.01). Serum miR-204 expression level of GC patients was significantly upregulated after receiving surgical resection (P < 0.01). In addition, serum miR-204 was associated with lymph node metastasis (P = 0.016), tumor differentiation (P = 0.001), and TNM stage (P = 0.005). GC patients with low serum miR-204 expression had shorter overall survival than those with high serum miR-204 expression (P = 0.004). Multivariate analysis revealed that serum miR-204 expression level was an independent risk factor for this malignant disease (HR = 3.629, 95%CI = 2.828-8.146, P = 0.015). In conclusion, our findings indicate that serum miR-204 may be employed as a novel biomarker for monitoring the treatment response and predicting the prognosis of GC.

A preliminary exploration of the relationship between tumour necrosis factor (TNF) and monocytic in vitro production of interleukin-1 (IL-1) and internal organ dysfunction in severely burned patients

Biological assays were adopted in this study to examine the changes in serum tumour necrosis factor (TNF) activity and blood monocytic in vitro production of interleukin 1 (IL-1) in 24 severely burned patients. The myocardial and hepatic enzymes (which included aspartate aminotransferase (AST), creatine kinase (CPK), lactate dehydrogenase (LDH), alpha hydroxybutyric dehydrogenase (alpha-HBDH) and alanine amino-transferase (ALT) and some indices of biochemical metabolism (including lactic acid (LA), total protein (TP), albumin (Alb) and colloid osmotic pressure (COP)) were simultaneously measured. The results showed an evident increase in serum TNF activity and a decrease in in vitro production of IL-1 postburn; all the changes in TNF and IL-1 were correlated significantly with those of myocardial and hepatic enzymes in MOF patients. Furthermore, there were marked fever, hypoproteinaemia, tissue ischaemic and hypoxic symptoms such as hyperlacticaemia, and signs reflecting tissue hypercatabolic states. These all suggested that TNF and IL-1 might play important roles in the development of MOF.

Clinical significance of the alterations of plasma prostaglandin E2 (PGE2) in severely burned patients

Agar gel single diffusion and radio immunological analyses were employed to determine the levels of serum C3c, C4, IgA, IgM, IgG and plasma PGE2 in 24 severely burned patients. The results were compared with the development of postburn immunosuppression, severe infection and MOF. There were marked decreases in serum C3c, C4 and Ig, which were especially marked in patients with MOF. Furthermore, plasma PGE2 decreased markedly in patients with MOF and/or severe systemic infection. The results suggest that the decrease of deficiency in plasma PGE2 was closely related to the immunosuppression and the development of severe systemic infection and/or MOF, which supported the hypothesis that PGE2 might play a role in immunoprotection, but not immunosuppression, in burned patients.

Attenuation of graft ischemia-reperfusion injury by urinary trypsin inhibitor in mouse intestinal transplantation

AIM: Ischemia/reperfusion (I/R) injury is one of the major obstacles for intestinal transplantation (ITx). Urinary trypsin inhibitor (Ulinastatin, UTI) suppresses proteases and stabilizes lysosomal membranes. We supposed that Ulinastatin would diminish I/R injury of intestinal graft.

METHODS: UTI- treated group and untreated control group were investigated by histological assessment at 1.5, 4, 24, and 72 h after ITx. Myeloperoxidase (MPO) activity was used as the activity of neutrophils, and malondialdehyde (MDA) was used as an index of lipid peroxidation. TNFα and i-NOS mRNA expression in graft tissue were measured by semi-quantitative RT-PCR. CD11b⁺ Gr1⁺ cells in graft lamina propria were analyzed by flow cytometry.

RESULTS: Histological scores of the graft showed that the tissue injury was markedly attenuated by UTI treatment at different time points after ITx, with reduced MPO and MDA value in the grafts. The expression of TNFα and i-NOS mRNA was profoundly inhibited, while the infiltration of CD11b⁺ Gr1⁺ cells into the intestinal graft was decreased in UTI group.

CONCLUSION: Urinary trypsin inhibitor attenuates I/R injury in mouse intestinal transplantation by reducing monocytes infiltration and down-regulation of TNFα and i-NOS mRNA expression.