The GE296_RS03820 and GE296_RS03830 genes are involved in capsular polysaccharide biosynthesis in Riemerella anatipestifer.

Riemerella anatipestifer is a pathogenic bacterium that causes duck serositis and meningitis, leading to significant harm to the duck industry. To escape from the host immune system, the meningitis-causing bacteria must survive and multiply in the bloodstream, relying on specific virulence factors such as capsules. Therefore, it is essential to study the genes involved in capsule biosynthesis in R. anatipestifer. In this study, we successfully constructed gene deletion mutants Δ3820 and Δ3830, targeting the GE296_RS03820 and GE296_RS03830 genes, respectively, using the RA-LZ01 strain as the parental strain. The growth kinetics analysis revealed that these two genes contribute to bacterial growth. Transmission and scanning electron microscopy (TEM and SEM) and silver staining showed that Δ3820 and Δ3830 produced the altered capsules and compounds of capsular polysaccharides (CPSs). Serum resistance test showed the mutants also exhibited reduced C3b deposition and decreased resistance serum killing. In vivo, Δ3820 and Δ3830 exhibited markedly declining capacity to cross the blood-brain barrier, compared to RA-LZ01. These findings indicate that the GE296_RS03820 and GE296_RS03830 genes are involved in CPSs biosynthesis and play a key role in the pathogenicity of R. anatipestifer. Furthermore, Δ3820 and Δ3830 mutants presented a tendency toward higher survival rates from RA-LZ01 challenge in vivo. Additionally, sera from ducklings immunized with the mutants showed cross-immunoreactivity with different serotypes of R. anatipestifer, including 1, 2, 7 and 10. Western blot and SDS-PAGE assays revealed that the altered CPSs of Δ3820 and Δ3830 resulted in the exposure of some conserved proteins playing the key role in the cross-immunoreactivity. Our study clearly demonstrated that the GE296_RS03820 and GE296_RS03830 genes are involved in CPS biosynthesis in R. anatipestifer and the capsule is a target for attenuation in vaccine development.

Metabolomics study of dietary Pleurotus eryngii ß-type glycosidic polysaccharide on colitis induced by dextran sodium sulfate in mice - Exploration for the potential metabolic indicators in urine and serum.

Pleurotus eryngii, an edible mushroom recognized for its potent polysaccharides, demonstrates significant regulatory effects on metabolic processes. ß-glucan (WPEP) derived from P. eryngii has been noted for its therapeutic potential, exhibiting notable benefits in alleviating colonic inflammation and restructuring gut microbiota in mice treated with dextran sodium sulfate (DSS). This study focuses on utilizing DSS-induced colitis mice to explore the efficacy and underlying mechanisms of WPEP in ameliorating colitis, employing a metabolomics approach analyzing urine and serum. The findings reveal that WPEP administration effectively regulates metabolic imbalances in DSS mice, impacting purine metabolism, pentose and glucuronic acid interconversion, amino acid metabolism, primary bile acid biosynthesis, citric acid cycle, and lipid metabolism. Furthermore, WPEP demonstrates a capacity to modulate colitis by regulating diverse metabolic pathways, consequently influencing intestinal barrier integrity, motility, inflammation, oxidative stress, and immunity. These insights suggest that WPEP is a promising food component for managing inflammatory bowel diseases.

Enhanced stability of encapsulated lemongrass essential oil in chitosan-gelatin and pectin-gelatin biopolymer matrices containing ZnO nanoparticles.

The use of essential oils is widespread in various fields such as pharmacy, pest control, and active packaging. However, their instability and short-term effects require methods to enhance their durability and effectiveness. Encapsulation in biopolymer matrices appears to be a promising approach due to the environmental safety and cost-effectiveness of such formulations. In this study, different oil-in-water emulsions were prepared by mixing chitosan-gelatin (C-G) or pectin-gelatin (P-G) solutions with lemongrass essential oil (LG). ZnO NPs were used as an additional active component. Encapsulation in biopolymer matrices resulted in stable emulsions with a significantly slower release of LG, and ZnO NPs further suppressed LG release, particularly in the P-G emulsion. They also contributed to the stability of the emulsions and a decrease in the average droplet size of LG. Furthermore, the presence of LG and ZnO NPs improved the smoothness of the films prepared from the emulsions and dispersions using the casting technique. SEM/EDS analysis confirmed the homogeneous distribution of ZnO NPs in both C-G and P-G films. By adjusting the type and content of the biopolymers and NPs, such emulsions could be effectively utilized in various applications where controlled release of active components is required.

Structural analysis and blood-enriching effects comparison based on biological potency of Angelica sinensis polysaccharides.

Angelica sinensis is a long-standing medicine used by Chinese medical practitioners and well-known for its blood-tonic and blood-activating effects. Ferulic acid, ligustilide, and eugenol in Angelica sinensis activate the blood circulation; however, the material basis of their blood-tonic effects needs to be further investigated. In this study, five homogeneous Angelica sinensis polysaccharides were isolated, and their sugar content, molecular weight, monosaccharide composition, and infrared characteristics determined. Acetylphenylhydrazine (APH) and cyclophosphamide (CTX) were used as inducers to establish a blood deficiency model in mice, and organ indices, haematological and biochemical parameters were measured in mice. Results of in vivo hematopoietic activity showed that Angelica sinensis polysaccharide (APS) could elevate erythropoietin (EPO), granulocyte colony-stimulating factor (G-CSF), and interleukin-3 (IL-3) serum levels, reduce tumor necrosis factor-α (TNF-α) level in mice, and promote hematopoiesis in the body by regulating cytokine levels. Biological potency test results of the in vitro blood supplementation indicated strongest tonic activity for APS-H2O, and APS-0.4 has the weakest haemopoietic activity. The structures of APS-H2O and APS-0.4 were characterized, and the results showed that APS-H2O is an arabinogalactan glycan with a main chain consisting of α-1,3,5-Ara(f), α-1,5- Ara(f), ß-1,4-Gal(p), and ß-1,4-Gal(p)A, and two branched chains of ß-t-Gal(p) and α-t-Glc(p) connected to each other in a (1→3) linkage to α-1,3,5-Ara(f) on the main chain. APS-0.4 is an acidic polysaccharide with galacturonic acid as the main chain, consisting of α-1,4-GalA, α-1,2-GalA, α-1,4-Gal, and ß-1,4-Rha. In conclusion, APS-H2O can be used as a potential drug for blood replenishment in patients with blood deficiency, providing a basis for APS application in clinical treatment and health foods, as well as research and development of new polysaccharide-based drugs.

An optimize adaptable method for determining the monosaccharide composition of pectic polysaccharides.

Pectic polysaccharides are considered the highly complex natural plant polysaccharides which plays a vital role in plant tissue structure and human health. Detailed characterization of the monosaccharide composition can provide insights into the pectic polysaccharide structure. Nevertheless, when analyzing the monosaccharides of pectic polysaccharide, it is crucial to address the issue of incomplete hydrolysis that can occur due to the formation of acid-induced precipitates. Based on above, the main purpose of this article is to provide an optimized method for monosaccharide analysis of pectic polysaccharides through acid hydrolysis optimization using high-performance anion exchange chromatography (HPAEC) The results indicate that reducing the sample concentration to 0.5 mg/mL effectively reduces the acid gelling phenomenon and promotes the complete hydrolysis of pectin polysaccharides. The optimized parameters for acid hydrolysis involve 110 °C for 6 h in 2 M TFA. Furthermore, the consistency of this method is assessed, along with its ability to analyze pectin polysaccharides from various fruits. This hydrolysis approach holds promise for enabling accurate quantification of monosaccharide composition in pectic polysaccharides.

Integrated multi-omic analysis reveals the carbon metabolism-mediated regulation of polysaccharide biosynthesis by suitable light intensity in Bletilla striata leaves.

Bletilla striata, valued for its medicinal and ornamental properties, remains largely unexplored in terms of how light intensity affects its physiology, biochemistry, and polysaccharide formation. In this 5-month study, B. striata plants were exposed to three different light intensities: low light (LL) (5-20 µmol m-2·s-1), middle light (ML) (200 µmol m-2·s-1), and high light (HL) (400 µmol m-2·s-1). The comprehensive assessment included growth, photosynthetic apparatus, chlorophyll fluorescence electron transport, and analysis of differential metabolites based on the transcriptome and metabolome data. The results indicated that ML resulted in the highest plant height and total polysaccharide content, enhanced photosynthetic apparatus performance and light energy utilization, and stimulated carbon metabolism and carbohydrate accumulation. HL reduced Chl content and photosynthetic apparatus functionality, disrupted OEC activity and electron transfer, stimulated carbon metabolism and starch and glucose accumulation, and hindered energy metabolism related to carbohydrate degradation and oxidation. In contrast, LL facilitated leaf growth and increased chlorophyll content but decreased plant height and total polysaccharide content, compromised the photosynthetic apparatus, hampered light energy utilization, stimulated energy metabolism related to carbohydrate degradation and oxidation, and inhibited carbon metabolism and carbohydrate synthesis. Numerous genes in carbon metabolism were strongly related to polysaccharide metabolites. The katE and cysK genes in carbon metabolism were strongly related not only to polysaccharide metabolites, but also to genes involved in polysaccharide biosynthesis. Our results highlight that light intensity plays a crucial role in affecting polysaccharide biosynthesis in B. striata, with carbon metabolism acting as a mediator under suitable light intensity conditions.

Investigating the Anticancer Effects of Pleurotus Ostreatus Polysaccharide on G0/G1 Cell Cycle Arrest and Apoptosis in Ehrlich Ascites Carcinoma Cells.

Cancer is one of the leading causes of mortality worldwide. Despite the advancement of cancer treatment by various means including surgery, chemotherapy, etc., cancer is still a challenging disease to manage. This study was undertaken to investigate extraction, purification, structural elucidation, and the potential anti-cancer effects of Pleurotus ostreatus polysaccharide (POP). The anti-cancer activities were performed on the Ehrlich Ascites Carcinoma Cell Line. The results demonstrated that the MW of  POP was154649.8 Da with homopolysaccharide composed of D-glucose units, featuring (1→6)-α-D-Glcp backbone with O-6 branches and T-α-D-Glcp terminations. and the yield was 6.27%. was 6.27%, The antitumor activity assessment demonstrated significant cytotoxicity of POP against Ehrlich Ascites Carcinoma (EAC) cells, with an IC50 of 121.801 µg/mL, supported by LDH release analysis. POP inhibited cell migration, invasion, and colony formation, indicating its potential as an anti-cancer agent. POP elicited the apoptotic activity with the upregulation of Caspase-9 and Bax, and downregulation of Bcl-2. The DNA fragmentation assay further confirmed apoptosis-mediated DNA degradations. Additionally, POP-induced cell cycle arrest at the G0/G1 phase, by altering the expression of p53, Cyclin D, and Cdk4 proteins. So, Pleurotus ostreatus polysaccharide (POP) showed significant cytotoxicity on Ehrlich Ascites Carcinoma cells, indicating potential as an anti-cancer agent.

Evaluation of candidate International Standards for meningococcal capsular polysaccharide groups W and Y.

Two candidate International Standards for meningococcal capsular group W and Y (MenW and MenY, respectively) polysaccharides were assessed for their suitability as quantitative standards in various physicochemical assays. The study was designed to evaluate the intended purpose of these standards, namely, to standardize the quantification of the respective polysaccharide content in meningococcal polysaccharide and conjugate vaccines and their intermediate components. Twelve laboratories from eleven different countries participated in the collaborative study of candidate preparations for International Standards for MenW and MenY polysaccharide (coded 16/152 and 16/206, respectively). Unitage was assigned using the Resorcinol assay. Our proposals, on the basis of data from the Resorcinol assay were: 1) candidate standard for MenW polysaccharide (16/152) to be assigned a content of 1.015 ± 0.071 mg MenW polysaccharide per ampoule (expanded uncertainty with coverage factor k = 2.13, corresponding to a 95 % level of confidence) and 2) candidate standard for MenY polysaccharide (16/206) be assigned a content of 0.958 ± 0.076 mg MenY polysaccharide per ampoule (expanded uncertainty with coverage factor k = 2.26, corresponding to a 95 % level of confidence). The amount of polysaccharide per ampoule remained consistent under all stability conditions over a 36-month period.

A diverse set of Enterococcus-infecting phage provides insight into phage host-range determinants.

Enterococci are robust Gram-positive bacteria that pose a significant threat in healthcare settings due to antibiotic resistance, with vancomycin-resistant enterococci (VRE) most prominent. To tackle this issue, bacteriophages (bacterial viruses) can be exploited as they specifically and efficiently target bacteria. Here, we successfully isolated and characterised a set of novel phages: SHEF10, SHEF11, SHEF13, SHEF14, and SHEF16 which target E. faecalis (SHEF10,11,13), or E. faecium (SHEF13, SHEF14 & SHEF16) strains including a range of clinical and VRE isolates. Genomic analysis shows that all phages are strictly lytic and diverse in terms of genome size and content, quickly and effectively lysing strains at different multiplicity of infections. Detailed analysis of the broad host-range SHEF13 phage revealed the crucial role of the enterococcal polysaccharide antigen (EPA) variable region in its infection of E. faecalis V583. In parallel, the discovery of a carbohydrate-targeting domain (CBM22) found conserved within the three phage genomes indicates a role in cell surface interactions that may be important in phage-bacterial interactons. These findings advance our comprehension of phage-host interactions and pave the way for targeted therapeutic strategies against antibiotic-resistant enterococcal infections.

Saccharide mapping as an extraordinary method on characterization and identification of plant and fungi polysaccharides: A review.

Saccharide mapping was a promising scheme to unveil the mystery of polysaccharide structure by analysis of the fragments generated from polysaccharide decomposition process. However, saccharide mapping was not widely applied in the polysaccharide analysis for lacking of systematic introduction. In this review, a detailed description of the establishment process of saccharide mapping, the pros and cons of downstream technologies, an overview of the application of saccharide mapping, and practical strategies were summarized. With the updating of the available downstream technologies, saccharide mapping had been expanding its scope of application to various kinds of polysaccharides. The process of saccharide mapping analysis included polysaccharides degradation and hydrolysates analysis, and the degradation process was no longer limited to acid hydrolysis. Some downstream technologies were convenient for rapid qualitative analysis, while others could achieve quantitative analysis. For the more detailed structure information could be provided by saccharide mapping, it was possible to improve the quality control of polysaccharides during preparation and application. This review filled the blank of basic information about saccharide mapping and was helpful for the establishment of a professional workflow for the saccharide mapping application to promote the deep study of polysaccharide structure.

State-of-the-art progress on locust bean gum polysaccharide for sustainable food packaging and drug delivery applications: A review with prospectives.

Locust bean gum (LBG), a polysaccharide-based natural polymer, is being widely researched as an appropriate additive for various products, including food, gluten-free formulations, medicines, paper, textiles, oil well drilling, cosmetics, and medical uses. Drug delivery vehicles, packaging, batteries, and catalytic supports are all popular applications for biopolymer-based materials. This review discusses sustainable food packaging and drug delivery applications for LBG. Given the benefits of LBG polysaccharide as a source of dietary fiber, it is also being investigated as a potential treatment for many health disorders, including colorectal cancer, diabetes, and gastrointestinal difficulties. The flexibility of LBG polysaccharide allows it to form hydrogen bonds with water molecules, a crucial characteristic of biomaterials, and the film-forming properties of LBG are critical for food packaging applications. The extraction process of LBG plays an important role in properties such as viscosity and gel-forming properties. Moreover, there are multiple factors such as temperature, pressure, pH, etc. The LBG-based functional composite film is effective in improving the shelf life as well as monitoring the freshness of fruits, meat and other processed food. The LBG-based hydrogel is excellent carrier of drugs and can be used for slow and sustainable release of active components present in drugs. Thus, the primary goal of this review was to conduct a comprehensive evaluation of the literature with a focus on the composition, properties, processing, food packaging, and medicine delivery applications of LBG polysaccharides. Thus, we investigated the chemical composition, extraction, and characteristics of LBG polysaccharides that underlie their applications in the food packaging and medicine delivery fields.

Anti-inflammation mechanisms of a homogeneous polysaccharide from Phyllanthus emblica L. on DSS induced colitis mice via the gut microbiota and metabolites alteration.

Phyllanthus emblica L. offers promising therapeutic potential for inflammatory diseases. This study revealed the molecular structure of a homogeneous polysaccharide purified from Phyllanthus emblica L. (PEP-1) and evaluated its anti-inflammatory effects on ulcerative colitis (UC) in mice. In the in vivo experiment, administered in varying dosages to dextran sulfate sodium (DSS)-induced UC models, PEP-1 significantly alleviated colonic symptoms, histological damages and reshaped the gut microbiota. Notably, it adjusted the Firmicutes/Bacteroidetes ratio and reduced pro-inflammatory species, closely aligning with shifts in the fecal metabolites and metabolic pathways such as the metabolism of pyrimidine, beta-alanine, and purine. These findings underscore the potential of PEP-1 as a therapeutic agent for UC, providing insights into the mechanisms through gut microbiota and metabolic modulation.

Integrated microbiome and metabolome analysis reveals that new insight into Radix pseudostellariae polysaccharide enhances PRRSV inactivated vaccine.

In this study, we investigated how Radix pseudostellariae polysaccharide (RPP) enhances the immune response of the inactivated porcine reproductive and respiratory syndrome virus (PRRSV) vaccine through interactions with the microbiome and metabolome. We pretreated sows with 10 mg/kg body weight of RPP via drinking water for 7 days prior to intramuscular injection of the PRRSV vaccine. This significantly increased the concentrations of PRRSV GP5 protein antibody, interleukin (IL)-2, IL-4, IL-10, and interferon (IFN)-γ. Oral administration of RPP also significantly improved the abundance of beneficial bacteria in the stool, such as Parabacteroides distasonis, Prevotella_copri, Eubacterium_sp., and Clostridium_sp._CAG:226, and decreased the levels of potentially pathogenic bacteria, such as Paraeggerthella and [Clostridium] innocuum, compared to the vaccine alone. These bacterial changes were confirmed using quantitative real-time polymerase chain reaction (Q-PCR). Moreover, RPP treatment significantly increased the blood concentrations of L-theanine, taurodeoxycholic acid (TDCA), and N-arachidonoyl proline, and decreased the levels of L-glutamine, oclacitinib, lipoxin C4, and leukotriene C5 in sows after immunization (p< 0.05). The concentrations of various blood metabolites were validated using sandwich enzyme-linked immunosorbent assay (ELISA), confirming the accuracy of the metabolomics data. Intriguingly, the integration of microbiome and metabolome analyses highlighted the significance of Prevotella_copri and TDCA. We consequently developed a mouse immunity model using GP5 protein and discovered that oral administration of RPP significantly enhanced the levels of GP5 protein antibodies, IL-2, IL-4, IL-10, and IFN-γ in mouse serum. It also increased the number of CD3+ and CD3+CD4+ cells in the spleen. Additionally, Prevotella_copri was administered into the large intestine via the anus for 7 days prior to the intramuscular injection of the PRRSV GP5 protein. The results demonstrated a significant increase in TDCA and GP5 antibody concentration in the mouse serum, indicating that RPP modulates Prevotella_copri to elevate its metabolite TDCA, thereby enhancing the GP5 antibody level. In conclusion, oral administration of 10 mg/kg RPP optimizes gut flora diversity and blood metabolites, particularly Prevotella_copri and TDCA, thereby improving the immune response to the inactivated PRRSV vaccine.

Bacterial glycoengineering: Cell-based and cell-free routes for producing biopharmaceuticals with customized glycosylation.

Glycosylation plays a pivotal role in tuning the folding and function of proteins. Because most human therapeutic proteins are glycosylated, understanding and controlling glycosylation is important for the design, optimization, and manufacture of biopharmaceuticals. Unfortunately, natural eukaryotic glycosylation pathways are complex and often produce heterogeneous glycan patterns, making the production of glycoproteins with chemically precise and homogeneous glycan structures difficult. To overcome these limitations, bacterial glycoengineering has emerged as a simple, cost-effective, and scalable approach to produce designer glycoprotein therapeutics and vaccines in which the glycan structures are engineered to reduce heterogeneity and improve biological and biophysical attributes of the protein. Here, we discuss recent advances in bacterial cell-based and cell-free glycoengineering that have enabled the production of biopharmaceutical glycoproteins with customized glycan structures.

Structural characterization and hypoglycemic effect of polysaccharides of Polygonatum sibiricum.

Polygonatum sibiricum polysaccharide (PSP) was extracted and purified from raw material obtained from P. sibiricum. The structural features of PSP were investigated by Congo red, circular dichroism spectrum, high-performance gel permeation chromatography, scanning electron microscope, atomic force microscope, ultraviolet spectroscopy, and Fourier transform infrared spectroscopy analysis. In vitro simulations were conducted to investigate the kinetics of PSP enzyme inhibition. Moreover, a type II diabetes mouse model (T2DM) with streptozotocin-induced insulin resistance was established, and the indexes of lipid quadruple, insulin resistance index, oral glucose tolerance (OGTT), organ index, and pancreatic morphology of model mice were measured. The results showed that PSP mainly consists of monosaccharides, such as mannose, glucose, galactose, xylose, and arabinose. It also has a ß-glycosidic bond of a pyranose ring and an irregular reticulated aggregated structure with a triple helix. In vitro enzyme inhibition assays revealed that PSP acts as a reversible competitive inhibitor of α-glucosidase and α-amylase. Furthermore, PSP was found to reduce insulin resistance index, increase OGTT and serum insulin levels, decrease free fatty acid content to improve lipid metabolism, and lower glycated serum protein content to enhance glucose metabolism in T2DM mice, thereby leading to a reduction in blood glucose concentration. Additionally, PSP exhibited reparative effects on the damaged liver tissue cells and pancreatic tissue in T2DM mice. The experiment results provide a preliminary basis for the therapeutic mechanism of PSP about type II diabetes and a theoretical reference for application in food and pharmaceutical development.

Lycium Barbarum Polysaccharide-Derived Nanoparticles Protect Visual Function by Inhibiting RGC Ferroptosis and Microglial Activation in Retinal Ischemia‒Reperfusion Mice.

Retinal ischemia‒reperfusion (IR) is a major contributor to vision impairment and irreversible vision loss due to retinal ganglion cell (RGC) injury or loss. Contemporary therapeutic approaches predominantly focus on the amelioration of symptoms rather than addressing the fundamental etiological factors. Oxidative stress is a notable feature and an important mediator of IR damage. Lycium barbarum polysaccharide (LBP), the main active ingredient of Lycium barbarum, has various pharmacological effects, including antioxidation, immunoregulation, and neuroprotective effects. In this study, the ROS-consumable moiety phenylboronic acid pinacol ester (PBA) is introduced to LBP molecules, which can self-assemble into nanoparticles in aqueous solution. This nanoparticle (termed PLBP) can reduce the cellular ROS levels and enhance the antioxidant capability of RGCs by activating the NRF2 pathway, thus protecting RGCs from ferroptosis and preserving visual function in response to IR injury. PLBP also reduces neuroinflammation by inhibiting the ability of microglia to phagocytose, migrate, secrete inflammatory cytokines, and activate the NF-κB pathway. In conclusion, this approach can be used as an inspiration for the future development of neuroprotective drugs.

New synthesis of oligosaccharides modelling the M epitope of the Brucella O-polysaccharide.

Brucellosis is a dangerous zoonotic disease caused by bacteria of the genus Brucella. Diagnosis of brucellosis is based on the detection in animal and human sera of antibodies to the O-polysaccharide of Brucella lipopolysaccharide. The currently employed serodiagnosis of brucellosis relies on the use of the Brucella O-polysaccharide as a diagnostic antigen. However, the existence of bacterial species, which also express O-polysaccharides structurally similar to that of Brucella, may decrease the specificity of the brucellosis detection due to false-positive test results. It has been shown that the efficiency of the test can be significantly improved by using synthetic oligosaccharides that correspond to the so-called M epitope of the Brucella O-antigen. This epitope is characterized by an α-(1→3)-linkage between d-perosamine units and is unique to Brucella. Here we report on an efficient approach to the synthesis of oligosaccharides that model the M epitope of the Brucella O-polysaccharide. The approach is based on the use of the α-(1→3)-linked disaccharide thioglycoside as the key donor block. Its application allowed the straightforward assembly of a set of four protected oligosaccharides, which includes a disaccharide, two trisaccharides, and a tetrasaccharide, in five glycosylation steps. The synthesized oligosaccharides are planned to be used in the development of diagnostic tools for identifying brucellosis in humans and domestic animals, as well as a potential vaccine against it.

Anoectochilus roxburghii polysaccharide reduces D-GalN/LPS-induced acute liver injury by regulating the activation of multiple inflammasomes.

BACKGROUND: Acute liver injury (ALI) is a serious syndrome with a high mortality rate due to viral infection, toxic exposure, and autoimmunity, and its severity can range from mildly elevated liver enzymes to severe liver failure. Activation of the nod-like receptor pyrin domain-containing 3 (NLRP3) inflammasome is closely associated with the development of ALI, and the search for an inhibitor targeting this pathway may be a novel therapeutic option. Anoectochilus roxburghii polysaccharide (ARP) is a biologically active ingredient extracted from Anoectochilus roxburghii with immunomodulatory, antioxidant, and anti-inflammatory bioactivities and pharmacological effects. In this study, we focused on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced acute liver injury by ARP through inhibition of NLRP3 inflammasome. METHODS: An inflammasome activation model was established in bone marrow-derived macrophages (BMDMs) to investigate the effects of ARP on caspase-1 cleavage, IL-1ß secretion, and ASC oligomerization in inflammasomes under different agonists. We used the D-GalN/LPS-induced acute liver injury model in mice, intraperitoneally injected ARP or MCC950, and collected liver tissues, serum, and intraperitoneal lavage fluid for pathological and biochemical indexes. RESULTS: ARP effectively inhibited the activation of the NLRP3 inflammasome and had an inhibitory effect on non-classical NLRP3, AIM2, and NLRC4 inflammasomes. It also effectively inhibited the oligomerization of apoptosis-associated speck-like protein (ASC) from a variety of inflammatory vesicles. Meanwhile, ARP has good therapeutic effects on acute liver injury induced by D-GaIN/LPS. CONCLUSION: The inhibitory effect of ARP on a wide range of inflammasomes, as well as its excellent protection against acute liver injury, suggests that ARP may be a candidate for acute liver injury.

Antigen titers in cryptococcal meningitis: what determines how fast they fall?

Follow-up of previously healthy patients surviving cryptococcal meningitis found that cryptococcal antigen could be detected for more than one year in serum from 38 of 44 (86%) patients and in CSF from 20 of 31 patients (67%), far beyond the time of culture conversion. The speed of titer decline, measured as the number of days for a two fold drop in titer to occur, was slower in serum than in CSF. Speed of decline of antigen titers was much slower in serum and CSF for patients infected with C. gattii than C. neoformans. The speed of decline in CSF and serum titers was also much slower in patients who had received a ventriculoperitoneal shunt for increased intracranial pressure. The variable and extraordinarily slow rate of clearance in our patients did not appear to reflect differences in disease control but rather differences in species and shunting for increased intracranial pressure.

Evaluation of GC-MS for identification and characterization of pneumococcal serotype 24A, 24B, and 24F capsular polysaccharide.

Analysis of pneumococcal polysaccharides (PnPs) has been an arduous task, especially in similar serotypes. Pneumococci invades the host immune response by modulating capsule structure with small genetic changes making them indistinguishable from similar serotypes by conventional modes of analysis. The new serotype 24F causing invasive pneumococcal-resistant infection is an analytical challenge for its analysis as related serotypes 24A and 24B Ps share a common backbone. The difference in the branched chain which contains arabinitol and ribitol in 24F and 24B respectively are stereoisomers making their identification even more challenging. The composition analysis by GC-MS revealed distinct peaks for arabinitol in 24F and 24A Ps and ribitol in Pn 24B serotype polysaccharide. The mass spectral analysis confirmed their identification along with a heterologous cross-reactivity which confirmed anti-Pn-24F mAb reactive to Pn 24B than Pn 24A. The quantitative analysis of pneumococcal 24A, 24B and 24F using GC-MS showed sensitive analysis over the concentration range 3.125-200 µg/mL with regression coefficient >0.99 making ideal modality for the characterization, identification, and quantitation of pneumococcal 24A, 24B and 24F similar serotypes.