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Osteoarthritis (OA) is a whole-joint disorder involving inflammation in cartilage, synovium, and subchondral bone. An ex vivo inflammatory OA model incorporating various intra-articular tissues could facilitate the development of new OA therapeutics targeting whole joint tissue. In this study, an inflammatory ex vivo coculture system with bovine osteochondral explants (OCEs) and synovial explants (SEs) was induced using 1 ng/mL interleukin one beta and tumor necrosis factor alpha. Furthermore, 5-aminosalicylic acid (5-ASA), a promising OA drug reported previously, was assessed in the coculture system to evaluate the potential of the system to be applied in drug screening for OA treatment. Under inflammatory stimulation, cartilage and synovium tissues in monoculture displayed a strong inflammatory response transcriptionally, biochemically, and histologically. Under inflammatory conditions, coculture elevated the gene expression of IL-6 in synovium tissue compared with monocultured synovium. The synovium tissue in the coculture inflammatory group showed the highest synovitis score. The IL-8 release in the coculture medium was significantly higher than the additive amount in the OCE and SE monoculture groups under inflammatory microenvironment. For drug assessment, 5-ASA-treated group could promote the gene expression of CD163/CD86 and inhibit CD86 expression in synovium compared with inflammatory group. Moreover, the cumulative release of IL-6 into the medium was mitigated upon 5-ASA treatment. This study revealed the interaction between OCEs and SEs in an ex vivo coculture system. This preclinical coculture system could be used to evaluate the effects of novel OA drugs on both cartilage and synovium and explore the crosstalk mechanisms between intra-articular tissues.

The temporomandibular joint (TMJ) disc is a fibrocartilage tissue located between the mandibular condyle and the glenoid eminence, which is central to the TMJ functions. The TMJ disc is susceptible to irreparable degenerative changes or post-traumatic injuries, which can lead to the development of a disc-related disease. Scaffold-based tissue engineering offers the potential for regeneration and replacement of the damaged TMJ disc. The present review describes the biomaterials and manufacturing technologies used in scaffold-based TMJ disc engineering strategies and comprehensively evaluates the advantages and disadvantages of each strategy. As an understanding of the extracellular matrix (ECM) is fundamental for succesful TMJ disc tissue engineering, this review defines the key properties and roles of the TMJ disc ECM. Compared with the natural disc, the mechanical properties of the tissue-engineered TMJ disc are not satisfactory. Additionally, the in vivo durability of engineered discs and their long-term impact on the entire TMJ remain to be studied, especially in large-animal preclinical trials.

ABSTRACT Gut microbiota plays an important role in animal health, production and diseases. Little is known about whether heat stress alters the composition of quail gut microbiota; therefore, we studied the effects of heat stress on growth performance, antioxidant functions, heat shock proteins and caecal microbiota. Two groups of 40 (20-day-old) quails were set up, including a control reared at 24 ± 2°C and a heat stress group subjected to heat stress at 36 ± 2°C for 4 h per day for 7 consecutive days. We found that heat stress significantly elevated the relative expression levels of HSP70 and HSP90 mRNA in the thymus, bursa and spleen by real-time fluorescence quantitative PCR assay, indicating successful establishment of the experimental model. Heat stress was found to have an effect on gut microbiota composition. At the genus level, Alistipes were significantly increased in the heat stress group. PICRUSt2 function prediction revealed that most of the KEGG pathways with high temperature-induced abundance differences are metabolism-related. These data indicated that heat stress reduced the production performance of quails by affecting antioxidant functions, as well as the composition and structure of the intestinal microbiota. The results of this study provide technical information for conducting research on heat stress prevention and control techniques in quails.

In this paper, the physical and mechanical properties of TISCO steel slag were tested by composite activators with different ratios. The optimal neutral composite activator was determined, and the properties of neutral activated steel slag power-cement composite cementitious material with 30% cement content were studied. The experimental results indicated that the best ratio of gypsum: silica fume: sodium sulfate: sodium aluminate: self-made activator was 2.5:2.5:1:0.5. By XRD, SEM and TG-DTG detection, it was found that the less stable periclase reduced in 30% cement content and activated steel slag slurry. After 28d curing, the micro morphology and compactness of hydration products were not different from that of cement, even no incompletely hydrated particles. The voids between hydration products and the interface of different hydration products were continuously filled with hydration products over age. C-S-H and AFt generated by 7d activated SSP cement composite powder was greater than that of cement. At 28d, a small amount of Ca(OH)2 was generated. The results show that the combination of self-made neutral activator and other activators can improve the properties of cement steel slag powder composite cementitious material and improve the utilization rate of steel slag.

Diarthrodial joint diseases, affecting hundreds of millions of people worldwide, mainly include osteoarthritis and cartilage injuries. No consensus on joint disease models has been achieved so far owing to the complex aetiologies, pathophysiological mechanisms and heterogeneity of disorders. The disease models established using isolated chondrocytes or small animals have the weaknesses of lacking native extracellular matrix and inter-species differences in anatomical and biomechanical cartilage properties. Osteochondral explants (OCEs) from large-animal or human joints present characteristics of native articular cartilage, showing promising potential for application in research on joint diseases. The present review focuses on OCEs and highlights the OCE sources, harvesting techniques, culture systems, applications and future developments. The OCE-centred ex vivo system has the potential to develop into preclinical models mimicking human joint diseases to help elucidate disease mechanisms, prompt therapeutic strategies and facilitate the clinical translation of findings in basic research.

ABSTRACT This study investigated the effect of resveratrol on the immune and inflammatory responses and the mRNA levels of splenic toll-like receptor (TLR)-4 signaling pathway-related genes of broilers under heat stress (HS). One hundred and sixty-two birds were allocated to three groups, each with 6 replicates, for 21 continuous days. The three treatments were as follows: the control group (22 ± 1 °C), the HS (33 ± 1 °C for 10 h d-1 and 22 ± 1 °C for the remaining time) group and the HS + resveratrol (400 mg kg-1) group. At the end of the trial, one bird per replicate close to the average body weight (BW) was selected, exsanguinated, and slaughtered. Compared with the control group, the HS treatment decreased (p

Stocking hatchery-reared fish in natural shallow lakes is a common practice in Chinese fisheries. The success of these fisheries depends on the balance between the commercial value of the stock and the growth performance of stocked fish to rapidly reach commercial size. The mandarin fish Siniperca chuatsi has become a commercially important fishery in China. However, the performance of hatchery-reared mandarin fish (HMF) after release into natural environments and their interactions with wild mandarin fish (WMF) have received little attention. In this study, we compared the growth, feeding and reproduction of HMF with WMF in a shallow Yangtze lake. We found that 11 mo after release, the growth of HMF was significantly slower than that of WMF but rapidly caught up after 16-19 mo. This suggests that HMF may experience compensatory growth after 11 mo, which may be a result of a low reproductive investment compared to WMF. In addition, the trophic niche of HMF differed significantly from that of WMF, with a lower diversity of prey and a single dominant prey species. Furthermore, there was no significant diet overlap between HMF and WMF. Our findings demonstrated that the growth performance of HMF can equal or exceeded that of wild conspecifics, and that there was limited diet overlap with WMF, suggesting that the current stock enhancement programmes of releasing HMF can result in fish similar to that of WMF, with limited foraging competition.

The intervertebral disc (IVD) has long been known as a mechanical structure responsible for spinal flexibility and load distribution, while its dysfunction is a frequent source of pain and disability. In recent years, multiple signaling pathways contributing to the regulation of the IVD homeostasis in health and disease have been discovered. At the same time, crosstalk of the IVD with adjacent tissues, immune cells, nerve cells and systemic mediators has been identified as an essential mechanism of degeneration and repair. Such discoveries open the door for the design of new therapeutic and diagnostic targets. This Disc Biology Special Issue provides an abstract of cutting-edge findings in terms of tissue regulation, therapeutic intervention and preclinical models, which will help to improve the management of IVD disorders.

Intervertebral disc degeneration (IDD) is the leading cause of low-back pain. Implantation of hyaluronic acid (HA) is potentially a therapeutic strategy for IDD, but its pharmacological effects and mechanism under hypoxic conditions remain unclear. In this study, the expression of extracellular matrix genes and proteins were enhanced in nucleus pulposus cells (NPCs) in the presence of HA under hypoxic condition, as shown by real-time reverse transcription-polymerase chain reaction, immunofluorescence staining, and dimethylmethylene blue assays. Moreover, the expression of CD44 was increased in the presence of both HA and hypoxia compared to either alone. Using a bioinformatic database, hypoxia inducible factor-1α (HIF-1α), a key transcription factor in the hypoxic condition, was found to have 4 predicted binding sites on the CD44 promoter. CD44 expression was significantly increased by treatment with cobalt chloride or dimethyloxalylglycine. Over-expression of HIF-1α in NPCs significantly up-regulated the expression of CD44. The binding site of HIF-1α in the CD44 promoter region, was identified by promoter truncation experiments and chromatin immunoprecipitation assays. Taken together, these results indicated that hypoxic conditions positively potentiated the ability of NPCs matrix synthesis in the presence of HA, which correlated with the increasing CD44 expression by HIF-1α transcriptional activation.

Recently, the existence of the tissue renin-angiotensin system (tRAS) has been described for multiple tissues in humans, suggesting its fundamental role in the progression of inflammation and fibrosis. Evidence arises that tRAS might have an impact on the progression of periodontitis and bone loss. However, neither the role of tRAS nor its impact as a therapeutic target have been systematically evaluated for periodontal tissue. The present study sought to characterise tRAS in the periodontal tissue and the effect of its inhibition on periodontal inflammation and bone loss. This systematic review was performed according to the preferred reporting items for systematic reviews and meta analyses (PRISMA) statement. Literature was searched using Web of Science core collection (Web of Science), Medline (Ovid), Cochrane central register of controlled trials (Ovid), Cochrane database of systematic reviews (Ovid), Google Scholar databases and the references of the retrieved studies in March 2020. Information on study design, sample size, population, procedure, type of intervention, observation time, as well as information on sources of bias, was extracted and evaluated. From 455 identified articles, 17 were included in the qualitative synthesis and 11 were included in the quantitative synthesis. Outcomes of studies indicated that the inhibition of tRAS components led to a reduction of periodontal bone loss and inflammation, dependent on the inhibitor used. The findings suggested an important role of tRAS in the periodontal tissue and indicate a potential therapeutic approach for periodontal diseases.

Symptomatic intervertebral disc (IVD) degeneration accounts for significant socioeconomic burden. Recently, the expression of the tissue renin-angiotensin system (tRAS) in rat and bovine IVD was demonstrated. The major effector of tRAS is angiotensin II (AngII), which participates in proinflammatory pathways. The present study investigated the expression of tRAS in human IVDs, and the correlation between tRAS, inflammation and IVD degeneration. Human IVD tissue was collected during spine surgery and distributed according to principal diagnosis. Gene expression of tRAS components, proinflammatory and catabolic markers in the IVD tissue was assessed. Hydroxyproline (OHP) and glycosaminoglycan (GAG) content in the IVD tissue were determined. Tissue distribution of tRAS components was investigated by immunohistochemistry. Gene expression of tRAS components such as angiotensin-converting enzyme (ACE), Ang II receptor type 2 (AGTR2), angiotensinogen (AGT) and cathepsin D (CTSD) was confirmed in human IVDs. IVD samples that expressed tRAS components (n = 21) revealed significantly higher expression levels of interleukin 6 (IL-6), tumour necrosis factor α (TNF-α), a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 4 and 5 compared to tRAS-negative samples (n = 37). Within tRAS-positive samples, AGT, matrix-metalloproteinases 13 and 3, IL-1, IL-6 and IL-8 were more highly expressed in traumatic compared to degenerated IVDs. Total GAG/DNA content of non-tRAS expressing IVD tissue was significantly higher compared to tRAS positive tissue. Immunohistochemistry confirmed the presence of AngII in the human IVD. The present study identified the existence of tRAS in the human IVD and suggested a correlation between tRAS expression, inflammation and ultimately IVD degeneration.

Appropriate cell sources, bioactive factors and biomaterials for generation of functional and integrated annulus fibrosus (AF) tissue analogues are still an unmet need. In the present study, the AF cell markers, collagen type I, cluster of differentiation 146 (CD146), mohawk (MKX) and smooth muscle protein 22α (SM22α) were found to be suitable indicators of functional AF cell induction. In vitro 2D culture of human AF cells showed that transforming growth factor β1 (TGF-β1) upregulated the expression of the functional AF markers and increased cell contractility, indicating that TGF-β1-pre-treated AF cells were an appropriate cell source for AF tissue regeneration. Furthermore, a tissue engineered construct, composed of polyurethane (PU) scaffold with a TGF-β1-supplemented collagen type I hydrogel and human AF cells, was evaluated with in vitro 3D culture and ex vivo preclinical bioreactor-loaded organ culture models. The collagen type I hydrogel helped maintaining the AF functional phenotype. TGF-β1 supplement within the collagen I hydrogel further promoted cell proliferation and matrix production of AF cells within in vitro 3D culture. In the ex vivo IVD organ culture model with physiologically relevant mechanical loading, TGF-β1 supplement in the transplanted constructs induced the functional AF cell phenotype and enhanced collagen matrix synthesis. In conclusion, TGF-β1-containing collagen-PU constructs can induce the functional cell phenotype of human AF cells in vitro and in situ. This combined cellular, biomaterial and bioactive agent therapy has a great potential for AF tissue regeneration and rupture repair.

Objectives Studies have demonstrated high rates of mortality in people with proximal femoral fracture and SARS-CoV-2, but there is limited published data on the factors that influence mortality for clinicians to make informed treatment decisions. This study aims to report the 30-day mortality associated with perioperative infection of patients undergoing surgery for proximal femoral fractures and to examine the factors that influence mortality in a multivariate analysis.Setting Prospective, international, multicentre, observational cohort study.Participants Patients undergoing any operation for a proximal femoral fracture from 1 February to 30 April 2020 and with perioperative SARS-CoV-2 infection (either 7 days prior or 30-day postoperative).Primary outcome 30-day mortality. Multivariate modelling was performed to identify factors associated with 30-day mortality.Results This study reports included 1063 patients from 174 hospitals in 19 countries. Overall 30-day mortality was 29.4% (313/1063). In an adjusted model, 30-day mortality was associated with male gender (OR 2.29, 95% CI 1.68 to 3.13, p80 years (OR 1.60, 95% CI 1.1 to 2.31, p=0.013), preoperative diagnosis of dementia (OR 1.57, 95% CI 1.15 to 2.16, p=0.005), kidney disease (OR 1.73, 95% CI 1.18 to 2.55, p=0.005) and congestive heart failure (OR 1.62, 95% CI 1.06 to 2.48, p=0.025). Mortality at 30 days was lower in patients with a preoperative diagnosis of SARS-CoV-2 (OR 0.6, 95% CI 0.6 (0.42 to 0.85), p=0.004). There was no difference in mortality in patients with an increase to delay in surgery (p=0.220) or type of anaesthetic given (p=0.787).Conclusions Patients undergoing surgery for a proximal femoral fracture with a perioperative infection of SARS-CoV-2 have a high rate of mortality. This study would support the need for providing these patients with individualised medical and anaesthetic care, including medical optimisation before theatre. Careful preoperative counselling is needed for those with a proximal femoral fracture and SARS-CoV-2, especially those in the highest risk groups.Trial registration number NCT04323644

The thermal instability is one crucial factor leading to low bearing operation performance. This paper presents a novel experiment device for thermal performance investigation of an aircraft rolling bearings. A bidirectional fixing structure was designed to balance the spindle thermal deformation. The hydraulic loading was used and the oil injection manner was adopted in the new device. Experimental test was conducted using the new device and experimental results were compared with the calculation based on the temperature and thermal nodes theory. The comparison demonstrates that the temperature distribution trends between the theoretical and experimental results remained the same; specifically, the error between the theoretical and experimental results was 1.0 % under the condition of 200 kg load and 2250 rpm driving speed. Consequently, the analysis result shows that the new device is feasible and reliable to provide precise thermal characteristics for the aircraft rolling bearings.

ABSTRACT Avian leukosis virus subgroup J (ALV-J), a member of the retroviridae family, can infect both broilers and layers and induce a spectrum of different neoplasms, resulting in serious economic losses in poultry production. Epigallocatechin-3-gallate (EGCG), the major constituent of green tea, has demonstrated remarkable anti-inflammatory and cancer chemopreventive effects in many animal tumor bioassays, cell culture systems and epidemiological studies. To assess the antiviral effects of EGCG on ALV-J-induced cell apoptosis in vitro, DF-1 cells were treated with different EGCG concentrations (0, 5, 10, 20 and 40 µg/mL), and their antiviral effects were examined at different time points (0, 24, 48, 72 and 96 h) using a variety of assays. EGCG alleviated the ALV-J-induced apoptosis in a dose-dependent manner. Because high concentrations (20 and 40 µg/mL) inhibited DF-1 cell growth, and low concentration (5 µg/mL) did not suppress the ALV-J virus, 10 µg/mL was the most appropriate concentration. After 96 h of incubation, 10 µg/mL EGCG improved the ALV-J-triggered suppression of the nuclear transcription factor system by enhancing cytoplasmic NF-κB p50/p65 expression and inhibiting nuclear NF-κB p50/p65 expression, resulting in decreased cell apoptosis. These results demonstrated that EGCG inhibited ALV-J-induced apoptosis in DF-1 cells in a dose-dependent manner via the NF-κB signaling pathway, and that 10 µg/mL EGCG is the optimal concentration, which may be useful for therapeutic drug design.

In this article, an interfacial conductivity model for the surface potential and the drain current was proposed based on the metal-interface-ferroelectric-insulator-semiconductor (MIFIS) structure negative capacitance field effect transistor (NC-FET). The simulating results illustrate that the electrical conductivity ( σ ) of the interface layer between the electrode and ferroelectric thin film caused by lattice misfit plays an important role in the process of voltage amplifying and steep switching for the NC-FET. It is indicated that new device design rules should take into account this scenario.

The Chinese soft-shelled turtle Pelodiscus sinensis is a highly valued freshwater species cultured in China. A 122 d experiment was conducted to assess the effects of water spinach Ipomoea aquatica cultivation in floating beds on water quality, and growth performance and economic return of P. sinensis cultured in ponds. Two treatments, each in triplicate, with and without I. aquatica cultivation were designed. Results showed that the levels of total ammonia nitrogen (TAN), total nitrogen (TN), total phosphorus (TP), chlorophyll a (chl a) and turbidity in treatments with I. aquatica cultivation (IAC) were significantly (p < 0.05) lower than those in treatments without I. aquatica (control). Mean TN and TP concentrations in the IAC treatment were 27.9 and 42.5%, respectively, lower than in the control treatment at the end of the experiment. The presence of I. aquatica also has a positive effect on the performance of P. sinensis. Although no significant difference was found in specific growth rate (SGR) between the 2 treatments, mean survival rates, production and net income were significantly higher in the IAC treatment compared to the control (p < 0.05). These results suggest that I. aquatica cultivation in the pond system of turtles has a synergistic effect on overall economic return and is effective at improving turtle growth performance and water quality.

In the field of beam physics, two frontier topics have taken center stage due to their potential to enable new approaches to discovery in a wide swath of science. These areas are: advanced, high gradient acceleration techniques, and x-ray free electron lasers (XFELs). Further, there is intense interest in the marriage of these two fields, with the goal of producing a very compact XFEL. In this context, recent advances in high gradient radio-frequency cryogenic copper structure research have opened the door to the use of surface electric fields between 250 and 500 MV m ^−1 . Such an approach is foreseen to enable a new generation of photoinjectors with six-dimensional beam brightness beyond the current state-of-the-art by well over an order of magnitude. This advance is an essential ingredient enabling an ultra-compact XFEL (UC-XFEL). In addition, one may accelerate these bright beams to GeV scale in less than 10 m. Such an injector, when combined with inverse free electron laser-based bunching techniques can produce multi-kA beams with unprecedented beam quality, quantified by 50 nm-rad normalized emittances. The emittance, we note, is the effective area in transverse phase space ( x , p _x / m _e c ) or ( y , p _y / m _e c ) occupied by the beam distribution, and it is relevant to achievable beam sizes as well as setting a limit on FEL wavelength. These beams, when injected into innovative, short-period (1–10 mm) undulators uniquely enable UC-XFELs having footprints consistent with university-scale laboratories. We describe the architecture and predicted performance of this novel light source, which promises photon production per pulse of a few percent of existing XFEL sources. We review implementation issues including collective beam effects, compact x-ray optics systems, and other relevant technical challenges. To illustrate the potential of such a light source to fundamentally change the current paradigm of XFELs with their limited access, we examine possible applications in biology, chemistry, materials, atomic physics, industry, and medicine—including the imaging of virus particles—which may profit from this new model of performing XFEL science.

Food partitioning is one of the primary mechanisms facilitating the stable co-occurrence of competing species, but very few studies have investigated how food resource use of competing and closely related species varies with life-history stages and habitats. In Lake Erhai (China), the trophic niche of 2 congeneric and co-occurring invasive goby species (Rhinogobius cliffordpopei and R. giurinus) was examined to test the existence of an ontogenetic diet shift and to determine potential differences in trophic niche between species within a habitat and between habitats (i.e. littoral and profundal) within species. Results obtained from gut content and stable isotope analyses revealed a strong trophic niche shift during ontogeny, whereby juveniles mainly consumed macrozooplankton while sub-adults and adults increasingly consumed aquatic insects and Tubificidae. The trophic niche of juveniles was similar between species in each of the 2 habitats but significantly different for sub-adults and adults, notably in littoral habitat. Moreover, the trophic niche was similar between habitats for juveniles of each species, whereas it differed significantly between habitats for sub-adults and adults. This study demonstrates the importance of ontogeny and shows that habitat use can significantly affect food resource use and trophic relationships between 2 co-occurring fish species.

ere is great interest in how bone marrow derived stem cells make fate decisions. Numerous studies have investigated the role of individual growth factors on mesenchymal stem cell differentiation, leading to protocols for cartilage, bone and adipose tissue. However, these protocols overlook the role of biomechanics on stem cell differentiation. There have been various studies that have applied mechanical stimulation to constructs containing mesenchymal stem cells, with varying degrees of success. One critical fate decision is that between cartilage and bone. Articular motion is a combination of compressive, tensile and shear deformations; therefore, one can presume that compression alone is unlikely to be a sufficient mechanical signal to generate a cartilage-like tissue in vitro. Within this study, we aimed to determine the role of shear on the fate of stem cell differentiation. Specifically, we investigated the potential enhancing effect of surface shear, superimposed on cyclic axial compression, on chondrogenic differentiation of human bone marrow-derived stem cells. Using a custom built loading device we applied compression, shear or a combination of both stimuli onto fibrin/polyurethane composites in which human mesenchymal stem cells were embedded, while no exogenous growth-factors were added to the culture medium. Both compression or shear alone was insufficient for the chondrogenic induction of human mesenchymal stem cells. However, the application of shear superimposed upon dynamic compression led to significant increases in chondrogenic gene expression. Histological analysis detected sulphated glycosaminoglycan and collagen II only in the compression and shear group. The results obtained may provide insight into post-operative care after cell therapy involving mesenchymal stromal cells.

Systematic cold biases exist in the simulation for 2 m air temperature in the Tibetan Plateau (TP) when using regional climate models and global atmospheric general circulation models. We updated the albedo in the Weather Research and Forecasting (WRF) Model lower boundary condition using the Global LAnd Surface Satellite Moderate-Resolution Imaging Spectroradiometer albedo products and demonstrated evident improvement for cold temperature biases in the TP. It is the large overestimation of albedo in winter and spring in the WRF model that resulted in the large cold temperature biases. The overestimated albedo was caused by the simulated precipitation biases and over-parameterization of snow albedo. Furthermore, light-absorbing aerosols can result in a large reduction of albedo in snow and ice cover. The results suggest the necessity of developing snow albedo parameterization using observations in the TP, where snow cover and melting are very different from other low-elevation regions, and the influence of aerosols should be considered as well. In addition to defining snow albedo, our results show an urgent call for improving precipitation simulation in the TP.

DENV envelope glycoprotein (E) is responsible for interacting with host cell receptors and is the main target for the development of a dengue vaccine based on an induction of neutralizing antibodies. It is well known that DENV E glycoprotein has two potential N-linked glycosylation sites at Asn67 and Asn153. The N-glycans of E glycoprotein have been shown to influence the proper folding of the protein, its cellular localization, its interactions with receptors and its immunogenicity. However, the precise structures of the N-glycans that are attached to E glycoprotein remain elusive, although the crystal structure of DENV E has been determined. This study characterized the structures of envelope protein N-linked glycans on mature DENV-2 particles derived from insect cells via an integrated method that used both lectin microarray and MALDI-TOF-MS. By combining these methods, a high heterogeneity of DENV N-glycans was found. Five types of N-glycan were identified on DENV-2, including mannose, GalNAc, GlcNAc, fucose and sialic acid; high mannose-type N-linked oligosaccharides and the galactosylation of N-glycans were the major structures that were found. Furthermore, a complex between a glycan on DENV and the carbohydrate recognition domain (CRD) of DC-SIGN was mimicked with computational docking experiments. For the first time, this study provides a comprehensive understanding of the N-linked glycan profile of whole DENV-2 particles derived from insect cells.

The risk of coronary heart disease (CHD) is lower in women than in men, but increases in women after menopause. Some of the gender, age, and menopausal-related differences in CHD risk may relate to differences in lipoprotein subspecies. We therefore examined these subspecies in three groups of healthy subjects: premenopausal women (W, n = 72, mean age 41.2 +/- 6.5), postmenopausal women (PMW, n = 74, 55.8 +/- 7.4), and men (M, n = 139, 48.8 +/- 10.7). We measured plasma levels of lipids, lipoprotein cholesterol, apolipoproteins A-I, A-IV, B, C-III, and E, and lipoprotein subspecies Lp A-I, Lp A-I:A-II, Lp B, Lp B:C-III, and Lp B:E, as well as LDL and HDL particle sizes. Our data indicate that women have significantly higher values of HDL-C, apoA-I, apoE, and Lp A-I; larger LDL and HDL particle sizes; and lower values of triglyceride, apoB, and Lp B:C-III particles than men, with no difference in Lp A-I:A-II. Postmenopausal status was associated with significantly higher values of total cholesterol, triglyceride, VLDL-C, and LDL-C; increased levels of apoB, C-III, and E; elevated values of Lp B, Lp B:C-III, and Lp B:E; and lower levels of HDL-C along with smaller HDL particle size. Moreover, we noted a strong correlation between LDL and HDL particle size. Our data are consistent with the concepts that male gender confers decreases in HDL subspecies due to lower Lp A-I levels; while postmenopausal status results in higher levels of all apoB-containing lipoproteins (Lp B, Lp B:C-III, and Lp B:E). The lipoprotein alterations associated with male gender and postmenopausal status would be expected to increase CHD risk.

In order to investigate causes of variability in low density lipoprotein (LDL) particle size, we have assessed LDL composition in plasma from 66 subjects, each with a single LDL band, by 2-16% gradient gel electrophoresis, with a total of eight discrete sizes (LDL-1 to LDL-8). Lipoprotein concentrations were analyzed by standard methods; specific proteins were assessed by immunoassay and electrophoresis. Results showed decreased anhydrous molecular weight with size (2.67 +/- 0.07 x 10(6) to 1.78 +/- 0.19 x 10(6)), along with decreased relative content for cholesteryl ester (41.5% to 24.3%), free cholesterol (10.1% to 4.6%), and phospholipid (23.7% to 18.9%), and increased triglyceride (4.1% to 21.0%) and protein (20.5% to 31.2%) content. As LDL size decreased, the ratio of surface cholesterol to phospholipid decreased from 0.53 to 0.29, and the fraction of surface area covered by lipid decreased from 0.74 to 0.47. Moreover, core volume decreased with size from 24.2 A3 x 10(5) to 15.9 A3 x 10(5), and the ratio of surface-to-core lipids fell from 0.59 to 0.46. Based on surface pressures of 30 mN/m, the area covered by surface lipid was calculated to range from 6.45 A2 x 10(4) in the largest LDL, to 3.10 A2 x 10(4) in the smallest. Computer modeling indicates that alterations in the tertiary structure of apoB-100 are required to account for surface changes. The estimated core surface area requiring coverage by apoB increased with decreasing particle size from 2.26 A2 x 10(4) to 3.46 A2 x 10(4). To accommodate coverage of increasing relative surface area associated with decreasing size, apoB thickness at the interface was calculated to decrease from approximately 25 A to 16 A. Such conformational changes in apoB may alter exposed epitopes, possibly causing changes in LDL receptor binding affinity and resistance to oxidation.

A high resolution electrophoretic method has been developed to separate plasma high density lipoprotein (HDL) particles by size using 4-30% polyacrylamide agarose (PAA) gradient gels, Sudan black B staining, and laser densitometry. Fourteen distinct HDL bands were observed with HDL-1 being designated as the largest particle and HDL-14 as the smallest particle. HDL-1 was similar in size to ferritin (Stokes diameter 12.2 nm), HDL-8 to catalase (9.2 nm), and HDL-13 to lactate dehydrogenase (8.1 nm). HDL-1 to HDL-7 were found within the density range of HDL2b (d 1.063-1.10 g/ml), HDL-8 to HDL-10 within HDL2a (d 1.10-1.125 g/ml), and HDL-11 to HDL-14 within HDL3 (d 1.125-1.21 g/ml). On immunoblotting, apolipoprotein A-I (apoA-I) was found in all HDL bands examined, being most prominent in HDL-6, 11, and 12. ApoA-II was not detected in HDL bands 1-5, but was present in all other HDL bands and was most prominent in HDL-9. ApoE was detected mainly in HDL bands 1-7, and was observed in only trace amounts in other bands. Lp A-I isolated by immunoaffinity column chromatography from the plasma of five subjects contained five subspecies (HDL-5, 6, and 11-13), while Lp A-I/A-II also had five subspecies (HDL-8, 9, and 11-13) in these subjects. In normal subjects (n = 57) four or five HDL bands were generally observed, with HDL-9, 11, and 12 being the most frequently observed. Mean HDL particle score (method of sizing based on scanning densitometry, where low score indicates large size and high score indicates small size) was significantly correlated (P < 0.001) with the concentrations of HDL cholesterol (r = -0.796), HDL free cholesterol (r = -0.780), HDL cholesteryl ester (r = -0.683), HDL phospholipid (r = -0.663), HDL apoA-I (r = -0.577), and HDL protein (r = -0.459), but not with HDL triglyceride (r = 0.069). In addition, HDL particle score was significantly correlated (P < 0.05) with HDL total mass (r = -0.649), HDL free cholesterol content (% of total mass, r = -0.608), HDL triglyceride content (r = 0.415), HDL phospholipid content (r = -0.359), and HDL protein content (r = 0.295), but not with HDL cholesteryl ester content (r = -0.219) or HDL apoA-I content (r = 0.183).(ABSTRACT TRUNCATED AT 400 WORDS)