Time-dependent changes in RPILD and mortality risk in anti-MDA5+ DM patients: a cohort study of 272 cases in China.

OBJECTIVES: Anti-melanoma differentiation-associated gene 5 positive (anti-MDA5+) DM has a close relationship with rapidly progressive interstitial lung disease (RPILD) and is associated with high mortality. However, data regarding the time-dependent risk of RPILD and deaths during disease progression are limited. We conducted this study to investigate whether the risk of RPILD and death were time-dependent or not in anti-MDA5+ DM. METHODS: We assessed a cohort of 272 patients with anti-MDA5+ DM. The clinical characteristics of patients with anti-MDA5+ were collected, and COX regression was used to analyse independent risk factors for RPILD and death. We also described changes in risk of RPILD and death over time and their potential clinical implications. RESULTS: There were 272 anti-MDA5+ DM patients enrolled in this study. According to the multivariate cox regression analysis, short disease course, high CRP level, anti-Ro52 positive and anti-MDA5 titre (++∼+++) were independent risk factors of RPILD. High creatine kinase level, high CRP level and RPILD were independent risk factors for death, and >90% RPILD and 84% mortality occurred in the first 6 months after disease onset. Notably, the first 3 months is a particularly high-risk period, with 50% of RPILD and 46% of deaths occurring. Hazards regarding RPILD and mortality diminished over time during a median follow-up of 12 months. CONCLUSION: These results suggest significant, time-dependent changes in RPILD and mortality risk in anti-MDA5+ DM patients, providing a cut-off time window to estimate disease progression and poor prognosis.

Baicalin reduces blood lipids and inflammation in patients with coronary artery disease and rheumatoid arthritis: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Patients with rheumatoid arthritis (RA) have an increased risk of coronary artery disease (CAD) above the baseline. Baicalin possesses beneficial effects against both RA and CAD, but little is know on its clincial efficacy among patients manifesting both CAD and RA. METHODS: Three hundred seventy four patients with CAD and RA were randomized to receive either 500 mg baicalin or placebo orally everyday for 12 weeks. Lipid profile, cardiotrophin-1 (CT-1), high sensitivity C-reactive protein (hs-CRP), European League Against Rheumatism (EULAR) response were analyzed at the end of study period. RESULTS: After 12 week treatment, levels of triglycerides, total cholesterol, LDL-cholesterol and apolipoproteins, as well as CT-1 and hs-CRP, were all significantly improved in the baicalin group compared to the placebo group (1.12 ± 0.36 vs 1.87 ± 0.46 mmol/L, 2.87 ± 1.23 vs 3.22 ± 1.07 mmol/L, 1.38 ± 0.41 vs 1.16 ± 0.32 mmol/L, 1.31 ± 0.41 vs 1.23 ± 0.29 g/L, 42.9 ± 13.7 vs 128.4 ± 24.3 ng/mL, 1.64 ± 0.38 vs 3.9 ± 1.4 mg/dL, respectively). Significantly higher proportion of patients in the baicalin group (71%) reported good/moderate EULAR response than the placebo group (53%). CONCLUSION: Baicalin reduces blood lipids and inflammation in patients with both CAD and RA, supporting its further clinical application.

Red blood cell distribution width and neutrophil to lymphocyte ratio are correlated with disease activity of dermatomyositis and polymyositis.

BACKGROUND: Previous studies indicated that both red blood cell distribution width (RDW) and neutrophil to lymphocyte ratio (NLR) were useful indices in assessing the disease activity of autoimmune diseases. However, the evidence for the association between RDW, NLR and dermatomyositis (DM) and polymyositis (PM) is limited. The aim of this study is to investigate the association between the disease activity of PM/DM and both RDW and NLR. METHODS: Medical records of 114 PM/DM patients and 114 healthy controls were retrospectively reviewed, and their RDW, NLR and myositis disease activity assessment visual analogue scale (MYOACT) on admission were extracted. The correlations between RDW, NLR and MYOACT were analyzed using the Spearman approach and multivariable model. RESULTS: PM/DM patients had significantly higher RDW and NLR. Increased RDW in PM/DM patients was not completely attributed to decreased hemoglobin or therapeutic agents. Both RDW and NLR are independently and positively correlated MYOACT. CONCLUSION: Both RDW and NLR are useful indices in assessing the disease activity of PM/DM.

Association of SLC22A4 gene polymorphism with Rheumatoid arthritis in the Chinese population.

Rheumatoid arthritis (RA) is a chronic inflammatory disease with complex genetic factors. Single-nucleotide polymorphisms (SNPs) in the SLC22A4 gene have been previously reported to be associated with RA in Japanese but not European populations. This study further investigated the association of SLC22A4 polymorphisms, in particular slc2F1/slc2F2, with RA in the Chinese population, the largest Asian population. A total of 160 human subjects with 95 RA patients and 65 healthy controls were genotyped for slc2F1-G/A and slc2F2-C/T polymorphisms. The results showed that there was a significant difference in the genotype distribution of these two polymorphisms between the two groups. In addition, the presence of slc2F1 A allele and slc2F2 T allele carries a 1.93-fold and 2.14-fold increased risk for anticyclic citrullinated peptide (CCP) positivity, respectively. Overall, this study provided evidence that SLC22A4 gene polymorphisms played important roles in the etiology of RA in the largest Asian population, the Chinese population.

Systematic Investigation of the Degradation Properties of Nitrile-Butadiene Rubber/Polyamide Elastomer/Single-Walled Carbon Nanotube Composites in Thermo-Oxidative and Hot Oil Environments.

The physical blending method was used in order to prepare nitrile-butadiene rubber/polyamide elastomer/single-walled carbon nanotube (NBR/PAE/SWCNT) composites with better thermal-oxidative aging resistance. The interactions between SWCNTs and NBR/PAE were characterized using the Moving Die Rheometer 2000 (MDR 2000), rheological behavior tests, the equilibrium swelling method, and mechanical property tests. The 100% constant tensile stress and hardness of NBR/PAE/SWCNT composites increased from 2.59 MPa to 4.14 MPa and from 62 Shore A to 69 Shore A, respectively, and the elongation decreased from 421% to 355% with increasing SWCNT content. NBR/PAE/SWCNT composites had improved thermal-oxidative aging resistance due to better interactions between SWCNTs and NBR/PAE. During the aging process, the tensile strength and elongation at break decreased with the increase in aging time compared to the unaged samples, and the constant tensile stress gradually increased. There was a more significant difference in the degradation of mechanical properties when aged in a variety of oils. The 100% constant tensile stress of NBR/PAE/SWCNT composites aged in IRM 903 gradually increased with aging time while it gradually decreased in biodiesel. The swelling index gradually increased with increasing SWCNT content. Interestingly, the swelling index of the composites in cyclohexanone decreased with the increase in SWCNT content. The reasons leading to different swelling behaviors when immersed in different kinds of liquids were investigated using the Hansen solubility parameter (HSP) method, which provides an excellent guide for the application of some oil-resistant products.

Gender differences in patients with anti-MDA5-positive dermatomyositis: a cohort study of 251 cases.

OBJECTIVE: To investigate the impact of sex differences on the clinical characteristics and prognosis of patients with anti-melanoma differentiation-associated gene 5-positive dermatomyositis (MDA5+ DM). METHODS: We retrospectively analyzed a cohort of 251 patients with MDA5+ DM, including 71 in the male group and 180 in the female group. A multivariate logistic regression model was built to analyze independent risk factors for RPILD in each group. An ROC curve was drawn to evaluate the predictive value of independent risk factors. Kaplan‒Meier analysis was used to compare the cumulative survival rates, while the log-rank test was used to test for significant differences between the two groups. RESULTS: Patients in the male group had a significantly higher prevalence of heliotrope rash, V sign, severe interstitial lung disease (ILD), and rapidly progressive interstitial lung disease (RPILD) than those in the female group. Anti-Ro52 positivity, high CRP level and short disease were identified as independent risk factors for RPILD in both male and female groups by multivariate logistic regression analysis. The mortality rates of males and females were 33.8% and 22.0%, respectively, and the survival time of patients in the male group was shorter than that in the female group. CONCLUSION: Male patients with MDA5+ DM exhibit an increased risk of RPILD, elevated mortality rates and reduced overall survival time compared to their female counterparts, and anti-Ro52 positivity may be an unfavorable prognostic factor for these patients. Key Points • The prevalence of solar rash, V sign, severe interstitial lung disease (ILD) and rapidly progressive interstitial lung disease (RPILD) in anti-MDA5-positive female patients was significantly lower than that in male patients. • Positive Anti-Ro52, high CRP level, and short course of disease were independent risk factors for RPILD in both men and women. • Female patients exhibited a lower mortality rate than male patients (22.0% vs 33.8%) and demonstrated longer survival time.

Rapidly progressive interstitial lung disease risk prediction in anti-MDA5 positive dermatomyositis: the CROSS model.

Background: The prognosis of anti-melanoma differentiation-associated gene 5 positive dermatomyositis (anti-MDA5+DM) is poor and heterogeneous. Rapidly progressive interstitial lung disease (RP-ILD) is these patients' leading cause of death. We sought to develop prediction models for RP-ILD risk in anti-MDA5+DM patients. Methods: Patients with anti-MDA5+DM were enrolled in two cohorts: 170 patients from the southern region of Jiangsu province (discovery cohort) and 85 patients from the northern region of Jiangsu province (validation cohort). Cox proportional hazards models were used to identify risk factors of RP-ILD. RP-ILD risk prediction models were developed and validated by testing every independent prognostic risk factor derived from the Cox model. Results: There are no significant differences in baseline clinical parameters and prognosis between discovery and validation cohorts. Among all 255 anti-MDA5+DM patients, with a median follow-up of 12 months, the incidence of RP-ILD was 36.86%. Using the discovery cohort, four variables were included in the final risk prediction model for RP-ILD: C-reactive protein (CRP) levels, anti-Ro52 antibody positivity, short disease duration, and male sex. A point scoring system was used to classify anti-MDA5+DM patients into moderate, high, and very high risk of RP-ILD. After one-year follow-up, the incidence of RP-ILD in the very high risk group was 71.3% and 85.71%, significantly higher than those in the high-risk group (35.19%, 41.69%) and moderate-risk group (9.54%, 6.67%) in both cohorts. Conclusions: The CROSS model is an easy-to-use prediction classification system for RP-ILD risk in anti-MDA5+DM patients. It has great application prospect in disease management.

Contributing Factors of Dielectric Properties for Polymer Matrix Composites.

Due to the trend of multi-function, integration, and miniaturization of electronics, traditional dielectric materials are difficult to satisfy new requirements, such as balanced dielectric properties and good designability. Therefore, high dielectric polymer composites have attracted wide attention due to their outstanding processibility, good designability, and dielectric properties. A number of polymer composites are employed in capacitors and sensors. All these applications are directly affected by the composite's dielectric properties, which are highly depended on the compositions and internal structure design, including the polymer matrix, fillers, structural design, etc. In this review, the influences of matrix, fillers, and filler arrangement on dielectric properties are systematically and comprehensively summarized and the regulation strategies of dielectric loss are introduced as well. Finally, the challenges and prospects of high dielectric polymer composites are proposed.

Identification of Three Different Phenotypes in Anti-Melanoma Differentiation-Associated Gene 5 Antibody-Positive Dermatomyositis Patients: Implications for Prediction of Rapidly Progressive Interstitial Lung Disease.

OBJECTIVE: There is substantial heterogeneity among the phenotypes of patients with anti-melanoma differentiation-associated gene 5 antibody-positive (anti-MDA5+) dermatomyositis (DM), hindering disease assessment and management. This study aimed to identify distinct phenotype groups in patients with anti-MDA5+ DM and to determine the utility of these phenotypes in predicting patient outcomes. METHODS: A total of 265 patients with anti-MDA5+ DM were retrospectively enrolled in the study. An unsupervised hierarchical cluster analysis was performed to characterize the different phenotypes. RESULTS: Patients were stratified into 3 clusters characterized by markedly different features and outcomes. Cluster 1 (n = 108 patients) was characterized by mild risk of rapidly progressive interstitial lung disease (RPILD), with the cumulative incidence of non-RPILD being 85.2%. Cluster 2 (n = 72 patients) was characterized by moderate risk of RPILD, with the cumulative incidence of non-RPILPD being 73.6%. Patients in cluster 3 (n = 85 patients), which was characterized by a high risk of RPILD and a cumulative non-RPILD incidence of 32.9%, were more likely than patients in the other 2 subgroups to have anti-Ro 52 antibodies in conjunction with high titers of anti-MDA5 antibodies. All-cause mortality rates of 60%, 9.7%, and 3.7% were determined for clusters 3, 2, and 1, respectively (P < 0.0001). Decision tree analysis led to the development of a simple algorithm for anti-MDA5+ DM patient classification that included the following 8 variables: age >50 years, disease course of <3 months, myasthenia (proximal muscle weakness), arthritis, C-reactive protein level, creatine kinase level, anti-Ro 52 antibody titer, and anti-MDA5 antibody titer. This algorithm placed patients in the appropriate cluster with 78.5% accuracy in the development cohort and 70.0% accuracy in the external validation cohort. CONCLUSION: Cluster analysis identified 3 distinct clinical patterns and outcomes in our large cohort of anti-MDA5+ DM patients. Classification of DM patients into phenotype subgroups with prognostic values may help physicians improve the efficacy of clinical decision-making.

Coexistence of Anti-Ro52 Antibodies in Anti-MDA5 Antibody-Positive Dermatomyositis Is Highly Associated With Rapidly Progressive Interstitial Lung Disease and Mortality Risk.

OBJECTIVE: Interstitial lung disease (ILD) is a common extramuscular complication contributing to significant morbidity and mortality in patients with dermatomyositis (DM) who are positive for antimelanoma differentiation-associated gene 5 antibody (anti-MDA5+). We conducted this study to investigate the association of anti-Ro52 antibodies with clinical characteristics and prognosis in patients with anti-MDA5+ DM. METHODS: We assessed a cohort of 246 patients with anti-MDA5+ DM. To calculate hazard ratios and 95% CIs for rapidly progressive ILD (RP-ILD) and death while controlling for potential confounders, variables selected by univariate Cox regression analysis were included in a multivariate Cox regression model with the stepwise forward-selection method. A 2-tailed analysis with P < 0.05 was considered to be statistically significant. RESULTS: A total of 246 patients with anti-MDA5+ DM were enrolled; 70 patients were male, and the patient group had an average age of 53.1 (12.4) years. Anti-Ro52 was present in 64.2% (158/246) patients. Patients with anti-MDA5+ DM who were positive for anti-Ro52 had a higher rate of RP-ILD (log-rank P < 0.001) and a higher mortality rate (log-rank P = 0.01). For patients with anti-MDA5+ DM who were positive for anti-Ro52, those with a short disease course and high inflammation were at increased risk of RP-ILD and death. The appearance of active rash was an independent protective factor of death. CONCLUSION: Anti-Ro52 antibodies were highly prevalent in patients with anti-MDA5+ DM, and their coexistence correlated with a higher rate of RP-ILD and mortality. Patients with a short disease course, with increased inflammation, and without rash were more likely to have a poor prognosis.

Bis[1-(eth-oxy-carbonyl-meth-yl)pyridinium] bis-(1,2-dicyano-ethene-1,2-dithiol-ato-κ(2)S,S')nickelate(II).

The asymmetric unit of the title ion-pair complex, (C(9)H(12)NO(2))(2)[Ni(C(4)N(2)S(2))(2)], contains two 1-(eth-oxy-carbonyl-meth-yl)pyridinium cations and one bis-(1,2-dicyano-ethene-1,2-dithiol-ato)nickelate(II) dianion, which exhibits a slightly distorted square-planar coordination geometry. In the crystal, the cations are linked by strong C-H⋯O hydrogen bonds into C(6) chains along [100]. The cations and anions are linked into a three-dimensional architecture by weak C-H⋯N and C-H⋯S inter-actions.

Upregulated miR-146a Expression in Peripheral Blood Relates to Th17 and Treg Imbalance in Elder Rheumatoid Arthritis Patients.

BACKGROUND: The expression level of microRNA-146a (miR-146a) increased in peripheral blood and synovialis tissue of rheumatoid arthritis (RA) patient, and it may play an important role in the pathological process of RA. We investigated its possibility as a diagnostic marker and the correlation with T helper 17 (Th17) and Treg cells in elder RA patients. METHODS: Blood samples were collected from 38 active RA patients, 38 inactive RA patients, and 40 healthy controls. RNA expression levels of miR-146a were detected from the peripheral blood samples. The proportion of Th17 and Treg cells were analyzed, as well as their cell-specific transcription factor retinoic acid-related orphan receptor variant 2 (RORc) and forkhead box protein 3 (FOXP3). Furthermore, secretion of pre-inflammatory and anti-inflammatory factors was detected. Correlations between miR-146a and these factors were also analyzed. RESULTS: Compared with healthy control, expression levels of miR-146a in inactive and active groups were significantly higher, with the highest level in active group. The expression of miR-146a and the RA severity, Th17 cell ratio, RORc expression, IL-17 level showed a significant positive correlation, while it showed a significantly negative correlation with Treg cell ration, FOXP3 expression, and TGF-ß1 secretion. CONCLUSIONS: These results suggested that miR-146a may be used as a disease progression marker in the peripheral blood of elder RA patients.

High-Dielectric PVP@PANI/PDMS Composites Fabricated via an Electric Field-Assisted Approach.

Polymer-based composite films with multiple properties, such as low dielectric loss tangent, high dielectric constant, and low cost are promising materials in the area of electronics and electric industries. In this study, flexible dielectric films were fabricated via an electric field-assisted method. Polyaniline (PANI) was modified by polyvinylpyrrolidone (PVP) to form a core-shell structure to serve as functional particles and silicone rubber polydimethylsiloxane (PDMS) served as the matrix. The dielectric constant of the composites prepared under electric fields was improved by the micro-structures formed by external electric fields. With the addition of 2.5 wt% PVP@PANI, the dielectric constant could be significantly enhanced, up to 23; the dielectric loss tangent is only 1, which is lower than that of the aligned PANI samples. This new processing technology provides important insights for aligning fillers in polymer matrix to form composites with enhanced dielectric properties.

The Bladder Microbiome, Metabolome, Cytokines, and Phenotypes in Patients with Systemic Lupus Erythematosus.

Emerging studies reveal unique bacterial communities in the human bladder, with alteration of composition associated to disease states. Systemic lupus erythematosus (SLE) is a complex autoimmune disease that is characterized by frequent impairment of the kidney. Here, we explored the bladder microbiome, metabolome, and cytokine profiles in SLE patients, as well as correlations between microbiome and metabolome, cytokines, and disease profiles. We recruited a group of 50 SLE patients and 50 individually matched asymptomatic controls. We used transurethral catheterization to collect urine samples, 16S rRNA gene sequencing to profile bladder microbiomes, and liquid chromatography-tandem mass spectrometry to perform untargeted metabolomic profiling. Compared to controls, SLE patients possessed unique bladder microbial communities and increased alpha diversity. These differences were accompanied by differences in urinary metabolomes, cytokines, and patients' disease profiles. The SLE-enriched genera, including Bacteroides, were positively correlated with several SLE-enriched metabolites, including olopatadine. The SLE-depleted genera, such as Pseudomonas, were negatively correlated to SLE-depleted cytokines, including interleukin-8. Alteration of the bladder microbiome was associated with disease profile. For example, the genera Megamonas and Phocaeicola were negatively correlated with serum complement component 3, and Streptococcus was positively correlated with IgG. Our present study reveals associations between the bladder microbiome and the urinary metabolome, cytokines, and disease phenotypes. Our results could help identify biomarkers for SLE. IMPORTANCE Contrary to dogma, the human urinary bladder possesses its own unique bacterial community with alteration of composition associated with disease states. Systemic lupus erythematosus (SLE) is a complex autoimmune disease often characterized by kidney impairment. Here, we explored the bladder microbiome, metabolome, and cytokine profiles in SLE patients, as well as correlations between the microbiome and metabolome, cytokines, and disease profiles. Compared to controls, SLE patients possessed a unique bladder microbial community and elevated alpha diversity. These differences were accompanied by differences in bladder metabolomes, cytokines, and patients' disease profiles. SLE-enriched genera were positively correlated with several SLE-enriched metabolites. SLE-depleted genera were negatively correlated to SLE-depleted cytokines. Alteration of the bladder microbiome was associated with disease profile. Thus, our study reveals associations between the bladder microbiome and the bladder metabolome, cytokines, and disease phenotypes. These results could help identify biomarkers for SLE.

Distinct Microbiomes of Gut and Saliva in Patients With Systemic Lupus Erythematous and Clinical Associations.

Alterations in the microbiome of the gut and oral cavity are involved in the etiopathogenesis of systemic lupus erythematosus (SLE). We aimed to assess whether both microbiome compositions in feces and saliva were specific in patients with SLE. A total of 35 patients with SLE, as well as sex- and age-matched asymptomatic subjects as healthy control (HC) group were recruited. Fecal swabs and saliva samples were collected from the participants. 16S ribosomal RNA gene sequencing was performed on the samples. Compared with the HC group, reduced bacterial richness and diversity were detected in the feces of patients with SLE, and increased bacterial diversity in their saliva. Both feces and saliva samples explained the cohort variation. The feces were characterized by enrichment of Lactobacillus, and depletion of an unclassified bacterium in the Ruminococcaceae family and Bifidobacterium. Lack of Bifidobacterium was observed in patients with arthritis. Akkermansia and Ruminococcus negatively correlated with the serum levels of C3. In saliva, Veillonella, Streptococcus, and Prevotella were dominant, and Bacteroides was negatively associated with disease activity. These findings can assist us to comprehensively understand the bacterial profiles of different body niches in SLE patients.

Resveratrol improves treatment outcome and laboratory parameters in patients with Takayasu arteritis: A randomized double-blind and placebo-controlled trial.

Tumor necrosis factor (TNF) inhibitors have exhibited certain clinical efficacy in treating refractory Takayasu arteritis (TA), albeit with severe adverse effects. We aimed to explore the anti-TNF function of resveratrol, a natural compound, in the treatment of TA. A total of 271 patients diagnosed of acute TA were enrolled in this clinical trial, who were then randomized to be administered 250mg resveratrol or placebo on a daily basis for a period of 3 months, and revisited biweekly to assess treatment outcomes. Primary treatment outcome was defined as the disease activity, determined using the Birmingham Vascular Activity Score (BVAS). Secondary outcome was defined by laboratory parameters, including erythrocyte sedimentation rate (ESR), plasma levels of C-reactive protein (CRP) and TNF-α. BVAS score and laboratory parameters of patients receiving resveratrol treatment exhibited a steady decline throughout the study. In contrast, outcomes remained practically unchanged in placebo-treated patients. Strong linear correlations were also observed between TNF-α with BVAS scores, ESR and plasma levels of CRP. Resveratrol could greatly improve treatment outcome and laboratory parameters in acute TA patients, likely due to its anti-TNF property.

Thalidomide treatment in cutaneous lesions of systemic lupus erythematosus: a multicenter study in China.

Thalidomide is effective for treating severe cutaneous lupus patients. The aim of this study was to observe the optimum effective and maintenance doses of thalidomide to maximize clinical benefit and minimize side effects for patients with cutaneous lupus in China. Sixty-nine patients with lupus rash from eight hospitals in China were enrolled and treated with different doses of thalidomide. We started the dose of thalidomide at 25 mg daily and gradually increased administration dose once a week until erythema was markedly improved. The effective and maintenance doses were documented. The size of skin lesions was noted once a week. Systemic lupus erythematosus disease activity index (SLEDAI) score, levels of erythrocyte sedimentation rate (ESR), and serum TNF-α were measured before and after treatment. The remission rates were evaluated weekly until 8 weeks. Sixty-eight percent of patients showed an effective dose of 50 mg daily; another 13, 10, and 9 % of patients had an effective dose of 100, 75, and 25 mg daily, respectively. The maintenance dose was 50 mg daily for 71 % of the patients, and 100, 75, and 25 mg daily for 9, 14, and 6 % of the patients. SLEDAI score and serum ESR levels significantly decreased 4 weeks after thalidomide treatment. At the end of the fourth week, the rates of complete remission, partial remission, and no response were 56 % (n = 39), 41 % (n = 28), and 3 % (n = 2). At the eighth week, the rate of total remission rose up to 100 %. The most common side effects were drowsiness and constipation. No peripheral neuropathy was observed in these patients. Thalidomide at a dose of 50 mg daily may offer a better benefit to risk ratio in the treatment of Chinese cutaneous lupus patients.

Sensitive and selective amplified visual detection of cytokines based on exonuclease III-aided target recycling.

A new Exo III assisted strand-cleavage cycle and ligand-responsive quadruplex formation strategy for amplified and label-free detection of IFN-γ was reported with a detection limit of 0.1 pM and a visual detection limit of 20 pM by the naked eye.

Anti-tumor activity of the regenerated triple-helical polysaccharide from Dictyophora indusiata.

A triple helical polysaccharide (PD3) was isolated from Dictyophora indusiata. After denaturation in dilute NaOH solution (0.3 M) and renaturation by sequential dialysis, regenerated polysaccharide (RPD3) was obtained. The physico-chemical properties of RPD3 including intrinsic viscosity [η], molecular weight (Mw) and optical rotation were similar to those of PD3, which suggested that RPD3 also had a triple helical structure after denaturation-renaturation. However, different intrinsic viscosity dependence on the concentration of NaOH solution was noted in PD3 and RPD3, which indicated that RPD3 had lower chain tightness compared with PD3. The anti-tumor activity of this polysaccharide after denaturation-renaturation treatment was further investigated. Both PD3 and RPD3 showed no direct cytotoxicity against S-180 cells in vitro but behaved anti-tumor activity in vivo. Meanwhile, RPD3 in high-dose group showed much higher anti-tumor activity than that of PD3, suggesting that the denaturation-renaturation treatment improved the bioactivity of the polysaccharide from D. indusiata.