Metastasis-associated protein 1 participates in regulating luminal acidification of the epididymis via repressing estrogen receptor alpha transcription.

BACKGROUND: As a component of the nucleosome remodeling and deacetylating (NuRD) complex, metastasis-associated protein 1 (MTA1) has been reported to be abundant in male reproductive system and might participate in spermatogenesis and sperm maturation, whereas the precise functional role of MTA1 in these processes is still undetermined. OBJECTIVE: To investigate the effect and potential function of MTA1 in male fertility. MATERIALS AND METHODS: Mta1 knockout mice (Mta1-/- ) were employed to detect their reproductive phenotype. The pH value of Mta1-/- epididymal luminal fluid was measured, and the potential mechanism of MTA1 involved in regulating luminal acidification was detected in vivo and in vitro. A vasectomy model with abnormal pH of epididymal lumen was established to further detect the effect of MTA1 on epididymal luminal microenvironment. RESULTS: Mta1-/- mice were fertile without any detectable defects in spermatogenesis or sperm motility while the deficiency of MTA1 could acidify the initial segment of epididymis to a certain extent. MTA1 could interact with estrogen receptor alpha (ERα) and inhibit the transcription of ERα target gene, hydrogen exchanger 3 (NHE3), and ultimately affect the epididymal luminal milieu. After vasectomy, the Mta1-/- mice presented a more acidic epididymal lumen which was closer to the normal state compared to the wild-type model. DISCUSSION AND CONCLUSION: MTA1 is dispensable for male fertility in mice, but plays a potentially important function in regulating luminal acidification of the epididymis.

Unveiling the inverse antimicrobial impact of a hetero-chitooligosaccharide on Candida tropicalis growth and biofilm formation.

Chitosan and chitooligosaccharide (COS) are renowned for their potent antimicrobial prowess, yet the precise antimicrobial efficacy of COS remains elusive due to scant structural information about the utilized saccharides. This study delves into the antimicrobial potential of COS, spotlighting a distinct hetero-chitooligosaccharide dubbed DACOS. In contrast to other COS, DACOS remarkably fosters the growth of Candida tropicalis planktonic cells and fungal biofilms. Employing gradient alcohol precipitation, DACOS was fractionated, unveiling diverse structural characteristics and differential impacts on C. tropicalis. Notably, in a murine model of systemic candidiasis, DACOS, particularly its 70 % alcohol precipitates, manifests a promotive effect on Candida infection. This research unveils a new pathway for exploring the intricate nexus between the structural attributes of chitosan oligosaccharides and their physiological repercussions, underscoring the imperative of crafting chitosan and COS with meticulously defined structural configurations.

Predictive value of preoperative platelet count and D-dimer levels for spinal cord injury following acute type a aortic dissection.

BACKGROUND: This study aims to identify the risk factors contributing to spinal cord injury (SCI) following a type A acute aortic dissection (TA-AAD). METHODS: This retrospective study was conducted at a single center and involved 481 patients who received frozen elephant trunk stent implantation for TA-AAD. Additionally, these patients underwent total arch replacement with deep hypothermic circulatory arrest. This study was performed at Fuwai Hospital between September 2016 and April 2020. RESULTS: The resulting data of the multivariate logistic regression analysis demonstrated that preoperative platelet count (odds ratio [OR] = 0.774) and D-dimer levels (OR = 2.247) could serve as independent predictors for postoperative SCI in patients with TA-AAD. CONCLUSION: The findings indicate that preoperative platelet count and D-dimer levels are independent risk factors for postoperative SCI in patients with TA-AAD. This study holds significant clinical implications regarding the prognosis and therapeutic responses for patients with TA-AAD.

Posterior False Lumen and Paraplegia After FET Procedure in Acute Type A Aortic Dissection.

BACKGROUND: Postoperative paraplegia is the major concern with the frozen elephant trunk (FET) procedure in patients with acute type A aortic dissection (ATAAD). It is crucial to identify patients with a high risk of paraplegia before implementing the FET procedure. METHODS: From January 2013 to December 2018, 544 patients with ATAAD who underwent FET procedures were included in this study. The segment number of posterior false lumens (PFLs) between T9 and L2 levels was calculated. In-hospital outcomes and long-term survival were investigated on the basis of the number of PFLs. RESULTS: The average age was 46.5 ± 9.9 years, and the proportion of female patients was 19.5% in this cohort. The incidence of postoperative paraplegia was significantly increased when PFL was present in 3 or more segments. Patients were divided into a high-PFL group (3-6 segments; n = 124) and a low-PFL group (0-2 segments; n = 420). The demographic characteristics were similar between the 2 groups. Involvement of the celiac trunk and the superior mesenteric artery was significantly lower in the high-PFL group (all P < .05). The other baseline characteristics and procedural information were statistically balanced. The incidence of postoperative paraplegia was significantly higher in the high-PHL group (7.3% vs 1.9;P = .006). Multivariable logistic analysis revealed that high PFL was independently associated with postoperative paraplegia after an FET procedure (odds ratio, 3.812; 95% CI, 1.378-10.550; P = .010). Additionally, the moderate nasopharyngeal temperature of hypothermic circulatory arrest (≧23.0 °C) was clarified as a protective factor for paraplegia (odds ratio, 0.112; 95% CI, 0.023-0.535; P = .006). CONCLUSIONS: Patients with ATAAD who present with high PFL between T9 and L2 levels have a significantly high risk of postoperative paraplegia if they undergo an FET procedure.

BDE-47 induces metabolic dysfunction-associated steatotic liver disease (MASLD) through CD36-mediated increased fatty acid uptake and PPARα-induced abnormal fatty acid oxidation in BALB/c mice.

The widespread existence of 2,2',4,4'-tetra-bromodiphenyl ether (BDE-47) in the environment has aroused great concern. BDE-47 induces the occurrence of metabolic dysfunction-associated steatotic liver disease (MASLD), but the mechanism has not been fully elucidated. Here, we further investigate the underlying mechanism using BALB/c mice. After BDE-47 exposure, the livers of mice enlarged, the serum levels of ALT, ALP, TG and TC enhanced, and hepatic steatosis occurred. Transcriptome sequencing identifies 2250 differentially expressed genes (DEGs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis reveals that down-regulated DEGs are mainly enriched in pathways associated with lipid metabolism, particularly in fatty acid (FA) degradation. And up-regulated DEGs are mainly enriched in pathways related to lipid and FA transport. The expression levels of AhR, Pparγ and Cd36 involved in FA uptake are up-regulated, and those of PPARα and target genes including Cpt1 and Cyp4a1 related to ß and ω-oxidation are inhibited. These results reveal BDE-47 could lead to metabolic dysfunction-associated steatotic liver disease (MASLD) by promoting FA uptake via upregulating Cd36 and hindering oxidative utilization by downregulating PPARα.

Risk factors and early outcomes of prolonged mechanical ventilation following redo aortic arch surgery: A retrospective study.

BACKGROUND: Redo aortic arch surgery is complex and associated with higher risks and mortality. Prolonged mechanical ventilation (PMV) after cardiac surgery is linked to early adverse outcomes and increased costs. OBJECTIVES: Identify specific risk factors and early complications associated with PMV following redo aortic arch surgery. METHODS: Retrospective study at Fuwai Hospital involving 203 patients. Data on patient characteristics, intraoperative factors, and outcomes were analyzed. RESULTS: A total of 203 patients were included, with 42.4 % requiring PMV. PMV patients had longer ICU stays (P < 0.001), lower discharge ADL scores (P < 0.001), and higher hospitalization costs (P < 0.001). While there was no significant difference in-hospital mortality between the two groups, the long-term survival rate in the PMV group was lower than that in the non-PMV group (P = 0.029). Multivariate analysis identified longer cardiopulmonary bypass time (OR 1.008, 95% CI, 1.002 - 1.014, P = 0.006), elevated intraoperative red blood cell transfusion(OR 1.214, 95% CI, 1.057 - 1.393, P = 0.006), higher PEEP (OR 1.296, 95% CI 1.089 - 1.542, P = 0.003), and total arch replacement (OR 3.241, 95% CI 1.392 - 7.543, P = 0.006) as independent risk factors for PMV. CONCLUSION: PMV following redo aortic arch surgery is linked to early adverse outcomes, increased healthcare costs, and reduced long-term survival, with longer cardiopulmonary bypass times, elevated intraoperative red blood cell transfusion, higher PEEP, and total arch replacement as independent risk factors.

Sonneralignan A, a new lignan from the fruit of mangrove Sonneratia apetala.

A new lignan, sonneralignan A (1), along with two known lignan compounds, (+)-lariciresinol-9-O-ß-D-glucopyranoside (2) and (-)isolariciresinol-9-O-ß-D-glucopyranoside (3) were isolated from the n-butanol extract of the mangrove Sonneratia apetala fruit. The structures of the compounds were elucidated on the basis of extensive spectral analysis. The evaluation of activity showed that compound 1 exhibited significant anti-aging activity, which extended the mean lifespan of Caenorhabditis elegans by up to 19.13% (p < 0.05) and 55.29% (p < 0.01) under normal and heat stress cultivation conditions, respectively. Molecular docking studies showed that compound 1 was bound to the DNA binding domain of DAF-16 and promoted the conformation of DAF-16, thus strengthening the interaction between the DAF-16 and related DNA. TRP-252, SER-250 and SER-249 of the binding region might be the key amino residues during the interaction.

Effectiveness of VA-ECMO plus intra-aortic balloon pump for cardiac shock in patients with type A aortic dissection: a case series.

Limited reports exist on the utilization of venoarterial extracorporeal membrane oxygenation (VA-ECMO) following aortic dissection surgery, possibly due to concerns regarding complications. This case series aimed to evaluate the effectiveness and safety of using VA-ECMO in combination with intra-aortic balloon pump (IABP) for managing postoperative cardiogenic shock in patients with type A aortic dissection (AAD). The study included nine patients with an average age of 57.0 ± 9.5 years. The patients underwent various surgical procedures, including coronary artery bypass grafting (CABG) and aortic root reconstruction. The results showed that the combined use of VA-ECMO and IABP was feasible and effective in managing postoperative cardiogenic shock in AAD patients. However, the in-hospital mortality rate was high, with six out of nine patients succumbing to the condition. Among the patients who received VA-ECMO plus IABP in the operating room, four were successfully weaned from VA-ECMO, and three survived with a mean follow-up of 20 months. The study also highlighted the potential risks of renal complications associated with VA-ECMO and IABP. The findings suggest that the combined therapy of VA-ECMO and IABP may be beneficial for patients who have difficulty weaning from cardiopulmonary bypass (CPB) after AAD surgery.

Evaluation and Mechanistic Investigation of Human Milk Oligosaccharide against SARS-CoV-2.

Four human milk oligosaccharides (HMOs), 3'-sialyllactose (3'-SL), 6'-sialyllactose (6'-SL), 2'-fucosyllactose (2'-FL), and 3-fucosyllactose (3-FL), were assessed for their possible antiviral activity against the SARS-CoV-2 spike receptor binding domain (RBD) in vitro. Among them, only 2'-FL/3-FL exhibited obvious antibinding activity against direct binding and trans-binding in competitive immunocytochemistry and enzyme-linked immunosorbent assays. The antiviral effects of 2'-FL/3-FL were further confirmed by pseudoviral assays with three SARS-Cov-2 mutants, with a stronger inhibition effect of 2'-FL than 3-FL. Then, 2'-FL/3-FL were studied with molecular docking and microscale thermophoresis analysis, showing that the binding sites of 2'-FL on RBD were involved in receptor binding, in addition to a tighter bond between them, thus enabling 2'-FL to be more effective than 3-FL. Moreover, the immunomodulation effect of 2'-FL was preliminary evaluated and confirmed in a human alveolus chip. These results would open up possible applications of 2'-FL for the prevention of SARS-CoV-2 infections by competitive binding inhibition.

Variations in metabolic enzymes cause differential changes of heparan sulfate and hyaluronan in high glucose treated cells on chip.

Glycocalyx dysfunction is believed as the first step in diabetic vascular disease. However, few studies have systematically investigated the influence of HG on the glycocalyx as a whole and its major constituent glycans towards one type of cell. Furthermore, most studies utilized traditional two-dimensional (2D) cultures in vitro, which can't provide the necessary fluid environment for glycocalyx. Here, we utilized vascular glycocalyx on chips to evaluate the changes of glycocalyx and its constituent glycans in HG induced HUVECs. Fluorescence microscopy showed up-regulation of hyaluronan (HA) but down-regulation of heparan sulfate (HS). By analyzing the metabolic enzymes of both glycans, a decrease in the ratio of synthetic/degradative enzymes for HA and an increase in that for HS were demonstrated. Two substrates (UDP-GlcNAc, UDP-GlcA) for the synthesis of both glycans were increased according to omics analysis. Since they were firstly pumped into Golgi apparatus to synthesize HS, less substrates may be left for HA synthesis. Furthermore, the differential changes of HA and HS were confirmed in vessel slides from db/db mice. This study would deepen our understanding of impact of HG on glycocalyx formation and diabetic vascular disease.

TGF-ß1 induced activations of Smad2 and miRNAs inhibit SF-1- and LRH-1-dependent CYP19 expression in rat Leydig cells†.

P450 aromatase, encoded by the Cyp19 gene, catalyzes the synthesis of estrogen, which is crucial for mammalian germ cell differentiation. We have previously shown that transforming growth factor beta 1 (TGF-ß1) attenuated the accumulation of steroidogenic factor-1 (SF-1) and liver receptor homolog-1 (LRH-1) and eventually reduced the transcription of Cyp19 in rat Leydig cells (LCs). Here, we report that TGF-ß1 treatment-induced phosphorylation of Smad2 and decreased the expression levels of SF-1 and LRH-1 by elevating the expression levels of microRNA-21-3p and microRNA-339-5p in vivo and in vitro. Furthermore, both TGF-ß1 treatment and over-expression of Smad2 inhibited the SF-1 or LRH-1-regulated promoter activity of the Cyp19 gene, and p-Smad2 physically interacted with SF-1 and LRH-1. Our findings collectively suggest that TGF-ß1 may inhibit the expression of CYP19 in LCs mainly through two ways. On the one hand, TGF-ß1 acts through Smad2 to repress the accumulation of SF-1 and LRH-1 at post-transcriptional level by upregulating specific microRNAs. On the other hand, TGF-ß1 inhibits the transcriptional activity of Cyp19 through the interaction of p-Smad2 with SF-1/LRH-1.

Advances in Innate Immunity to Overcome Immune Rejection during Xenotransplantation.

Transplantation is an effective approach for treating end-stage organ failure. There has been a long-standing interest in xenotransplantation as a means of increasing the number of available organs. In the past decade, there has been tremendous progress in xenotransplantation accelerated by the development of rapid gene-editing tools and immunosuppressive therapy. Recently, the heart and kidney from pigs were transplanted into the recipients, which suggests that xenotransplantation has entered a new era. The genetic discrepancy and molecular incompatibility between pigs and primates results in barriers to xenotransplantation. An increasing body of evidence suggests that innate immune responses play an important role in all aspects of the xenogeneic rejection. Simultaneously, the role of important cellular components like macrophages, natural killer (NK) cells, and neutrophils, suggests that the innate immune response in the xenogeneic rejection should not be underestimated. Here, we summarize the current knowledge about the innate immune system in xenotransplantation and highlight the key issues for future investigations. A better understanding of the innate immune responses in xenotransplantation may help to control the xenograft rejection and design optimal combination therapies.

BDE-47 disturbs the immune response of lymphocytes to LPS by downregulating NF-κB pathway.

The health risks associated with 2,2',4,4'-tetra-bromodiphenyl ether (BDE-47) have become an increasing concern due to its widespread presence in the environment and biological samples. To date, the potential toxicity of BDE-47 to immune system remains unclear. In this study, we aimed to study the immunotoxicity of BDE-47 using spleen-derived lymphocytes in vitro and BALB/c mice in vivo. In vitro results showed that lymphocytes exposed to 12.5-100 µM BDE-47 exhibited unchanged cell viability but decreased release of IL-6 and TNF-α when responding to lipopolysaccharide (LPS). The expression levels of p-p65, p-IκBα, TrkA and p-Akt involved in NF-κB pathway were obviously decreased, and NF-κB activator PMA could recover the BDE-47-induced inhibitory effect on IL-6 and TNF-α release by lymphocytes in response to LPS. In vivo data showed that BDE-47 orally administered to mice (1 mg/kg, 10 mg/kg, 100 mg/kg per day, 30 days) did not significantly affect body weight, organ index and histomorphology of spleen. However, ELISA assay showed that serum IL-6 and TNF-α levels from BDE-47-treated mice after intraperitoneal injection of LPS were significantly reduced, and high-throughput mouse cytokines screening found 13 more cytokines down-regulated in the serum. Transcriptomic sequencing of spleens identified 488 differential expressed genes (DEGs). GO enrichment analysis of these DEGs suggested that the GO term of response to LPS (GO: 0032,496) was significantly involved. KEGG enrichment analysis showed that the down-regulated DEGs significantly enriched in multiple immune-related signaling pathways including the NF-κB signaling pathway (mmu04064). Overall, these data suggested that BDE-47 could negatively regulate NF-κB signaling pathways to inhibit the immune response of lymphocytes to LPS, suggesting that exposures to BDE-47 may disturb the immune balance and increase the body's susceptibility to infectious diseases.

A Nomogram Model for Individualized Prediction of the Risk of Respiratory Tract Infection within Six Months after Diagnosis in Patients with Primary Immune Thrombocytopenia.

The risk factors of upper respiratory tract infection (URI) within 6 months after diagnosis in patients with idiopathic thrombocytopenic purpura (ITP) were analyzed, and the nomogram model was established and verified, with 242 and 50 ITP patients as the training and validation set, respectively. The patients were followed up for six months after the diagnosis of ITP. The clinical data of patients were collected, and the risk factors of URI in ITP patients within six months after diagnosis were analyzed using univariable, followed by multivariable logistic regression. Among the 242 ITP patients in the training set, 52 cases (21.49%) had URI, including 24 cases of viral infection, 11 cases of Mycoplasma pneumoniae infection, and 17 cases of bacterial infection. Logistic regression analysis showed that advanced age, use of glucocorticoid, smoking history, platelet count, serum CRP level, and lymphocyte subsets CD4 + and CD8 + were all risk factors for ITP patients to develop symptoms within six months after diagnosis (P < 0.05). Using the above five indicators, a nomogram prediction model was built for URI occurrence in patients with ITP within half a year after diagnosis, and the results showed an AUC, a sensitivity, and a specificity of 0.936 (95% CI: 0.878-0.983), 0.942, and 0.865, respectively. The nomogram model was internally verified by the bootstrap method for 500 self-sampling times, and the prediction of the calibration curve was in high consistency with the real results. External validation of the nomogram model resulted in an AUC, a sensitivity, and a specificity of 0.890 (95% CI: 0.757-0.975), 0.949, and 0.727, respectively. The nomogram model of URI in ITP patients within half a year after diagnosis based on logistic regression analysis has good discrimination and prediction accuracy. This provides important guidance value for individualized prediction of URI in ITP patients.

Chitosan Oligosaccharides Regulate the Occurrence and Development of Enteritis in a Human Gut-On-a-Chip.

Past studies on the protective effects of chitosan oligosaccharides (COS) on inflammatory bowel disease (IBD) commonly rely on animal models, because traditional cell culture systems couldn't faithfully mimic human intestinal physiology. Here a novel human gut-on-a-chip microsystem was established to further explore the regulatory effects of COS on the occurrence and development of human enteritis. By constructing an intestinal injury model caused by dextran sodium sulfate (DSS) on the chip, this study proved that COS can reduce intestinal epithelial injury by promoting the expression of the mucous layer for the first time. By establishing an inflammatory bowel disease model on the chip caused by E. coli 11775, this study demonstrated that COS can protect the intestinal epithelial barrier and vascular endothelial barrier by inhibiting the adhesion and invasion of E. coli 11775 for the first time. In addition, similar to the results in vivo, COS can decrease the inflammatory response by reducing the expression of toll-like receptor 4 protein and reducing the nuclear DNA binding rate of nuclear factor kappa-B protein on this chip. In summary, COS can be used as a potential drug to treat human IBD and the human gut-on-a-chip would be used as a platform for quick screening drugs to treat human IBD in future.

Immune Subtypes Characterization Identifies Clinical Prognosis, Tumor Microenvironment Infiltration, and Immune Response in Ovarian Cancer.

Objective: Because of the modest immunotherapeutic response among ovarian carcinoma (OC) patients, it is significant to evaluate antitumor immune response and develop more effective precision immunotherapeutic regimens. Here, this study aimed to determine diverse immune subtypes of OC. Methods: This study curated the expression profiles of prognostic immunologically relevant genes and conducted consensus clustering analyses for determining immune subtypes among OC patients in TCGA cohort. With Boruta algorithm, characteristic genes were screened for conducting an immune scoring system through principal component analysis algorithm. The single-sample gene set enrichment analysis and ESTIAMTE methods were adopted for quantifying the immune infiltrates and responses to chemotherapeutic agents were estimated with pRRophetic algorithm. Two immunotherapeutic cohorts were used for investigating the efficacy of immune score in predicting therapeutic benefits. Results: Two immune subtypes were conducted among 377 OC patients. Immune subtype 2 was characterized by worse clinical prognosis, more frequent genetic variations and mutations, enhanced immune infiltrates, and increased expression of MHC molecules and programmed cell death protein 1/programmed death ligand 1 (PD-1/PD-L1). In total, 30 prognosis-relevant characteristic immune subtype-derived genes were identified for constructing the immune score of OC patients. High immune score was linked with more dismal prognosis, decreased immune infiltrations, and expression of MHC molecules. High immune score presented favorable sensitivity to doxorubicin and vinorelbine and reduced sensitivity to cisplatin. In addition, immune score possessed the potential in predicting benefits from anti-PD-1/PD-L1 therapy. Conclusion: Collectively, our findings propose two complex and diverse immune subtypes of OC. Quantitative assessment of immune subtypes in individual patients strengthens the understanding of tumor microenvironment features and promotes more effective immunotherapeutic regimens.

High molecular weight chitosan oligosaccharide exhibited antifungal activity by misleading cell wall organization via targeting PHR transglucosidases.

The fungal cell wall is an ideal target for the design of antifungal drugs. In this study we used an analog of cell wall polymer, a highly deacetylated high molecular-weight chitosan oligosaccharide (HCOS), to test its effect against pathogenic Candida strains. Results showed that HCOS was successfully incorporated into the dynamic cell wall organization process and exhibited an apparent antifungal activity against both plankton and mature fungal biofilm, by impairing the cell wall integrity. Unexpectedly, mechanistic studies suggested that HCOS exerts its activity by interfering with family members of PHR ß-(1,3)-glucanosyl transferases and affecting the connection and assembly of cell wall polysaccharides. Furthermore, HCOS showed great synergistic activity with different fungicides against Candida cells, especially those in biofilm. These findings indicated HCOS has a great potential as an antifungal drug or drug synergist and proposed a novel antifungal strategy with structure-specific oligosaccharides mimicking cell wall polysaccharide fragments.

BDE-47 induced PC-12 cell differentiation via TrkA downstream pathways and caused the loss of hippocampal neurons in BALB/c mice.

As the most abundant congener of polybrominated diphenyl ethers (PBDEs) detected in environment and human biotic samples, 2, 2', 4, 4'-tetrabromodiphenyl ether (BDE-47) has been found to accumulate in brain and induce neurotoxicity, however, the detailed mechanism has not been clearly elucidated. To investigate the neurotoxicity of BDE-47, undifferentiated PC-12 cells were exposed to different doses of BDE-47, and BDE-47 dissolved in corn oil was orally administered to mice for 8 consecutive weeks. Our data showed that BDE-47 obviously changed cell morphology, altered cell viability, promoted cell apoptosis, and induced reactive oxygen species (ROS) production. BDE-47 promoted the differentiation of PC-12 cells by enhancing the expression of TrkA receptor and the phosphorylation levels of ERK and Akt. Moreover, BDE-47-induced differentiation of PC-12 cells was suppressed by inhibitors of corresponding pathways (MAPK/ERK and PI3K/Akt). H&E staining of brain showed neurons in DG and CA1 areas of hippocampus decreased after BDE-47 exposure. Transcriptome sequencing of brain tissue suggested that multiple signaling pathways related to neuron death and nerve function were significantly regulated. In conclusion, these results provided new evidence for revealing the neurotoxicity of BDE-47, and offered important experimental basis for environmental controlling and post-exposure health risk assessment of BDE-47.

Safety and efficacy of thalidomide in patients with transfusion-dependent ß-thalassemia: a randomized clinical trial.

Thalidomide induces γ-globin expression in erythroid progenitor cells, but its efficacy on patients with transfusion-dependent ß-thalassemia (TDT) remains unclear. In this phase 2, multi-center, randomized, double-blind clinical trial, we aimed to determine the safety and efficacy of thalidomide in TDT patients. A hundred patients of 14 years or older were randomly assigned to receive placebo or thalidomide for 12 weeks, followed by an extension phase of at least 36 weeks. The primary endpoint was the change of hemoglobin (Hb) level in the patients. The secondary endpoints included the red blood cell (RBC) units transfused and adverse effects. In the placebo-controlled period, Hb concentrations in patients treated with thalidomide achieved a median elevation of 14.0 (range, 2.5 to 37.5) g/L, whereas Hb in patients treated with placebo did not significantly change. Within the 12 weeks, the mean RBC transfusion volume for patients treated with thalidomide and placebo was 5.4 ± 5.0 U and 10.3 ± 6.4 U, respectively (P < 0.001). Adverse events of drowsiness, dizziness, fatigue, pyrexia, sore throat, and rash were more common with thalidomide than placebo. In the extension phase, treatment with thalidomide for 24 weeks resulted in a sustainable increase in Hb concentrations which reached 104.9 ± 19.0 g/L, without blood transfusion. Significant increase in Hb concentration and reduction in RBC transfusions were associated with non ß0/ß0 and HBS1L-MYB (rs9399137 C/T, C/C; rs4895441 A/G, G/G) genotypes. These results demonstrated that thalidomide is effective in patients with TDT.

Expression and Biochemical Characterization of a Novel Marine Chitosanase from Streptomyces niveus Suitable for Preparation of Chitobiose.

It is known that bioactivities of chitooligosaccharide (COS) are closely related to the degree of polymerization (DP); therefore, it is essential to prepare COS with controllable DP, such as chitobiose showing high antioxidant and antihyperlipidemia activities. In this study, BLAST, sequence alignment and phylogenetic analysis of characterized glycoside hydrolase (GH) 46 endo-chitosanases revealed that a chitosanase Sn1-CSN from Streptomyces niveus was different from others. Sn1-CSN was overexpressed in E. coli, purified and characterized in detail. It showed the highest activity at pH 6.0 and exhibited superior stability between pH 4.0 and pH 11.0. Sn1-CSN displayed the highest activity at 50 °C and was fairly stable at ≤45 °C. Its apparent kinetic parameters against chitosan (DDA: degree of deacetylation, >94%) were determined, with Km and kcat values of 1.8 mg/mL and 88.3 s-1, respectively. Cu2+ enhanced the activity of Sn1-CSN by 54.2%, whereas Fe3+ inhibited activity by 15.1%. Hydrolysis products of chitosan (DDA > 94%) by Sn1-CSN were mainly composed of chitobiose (87.3%), whereas partially acetylated chitosan with DDA 69% was mainly converted into partially acetylated COS with DP 2-13. This endo-chitosanase has great potential to be used for the preparation of chitobiose and partially acetylated COS with different DPs.