Inhibition of TTX-S Na+ currents by a novel blocker QLS-278 for antinociception.

Genetic loss-of-function mutations of Nav1.7 channel, abundantly expressed in peripheral nociceptive neurons, cause congenital insensitivity to pain (CIP) in humans, indicating that selective inhibition of the channel may lead to potential therapy of pain disorders. In this study, we investigated a novel compound, 5-chloro-N-(cyclopropylsulfonyl)-2-fluoro-4-(2-(8-(furan-2-ylmethyl)-8-azaspiro [4.5] decan-2-yl) ethoxy) benzamide (QLS-278) that inhibits Nav1.7 channel and exhibits anti-nociceptive activity. Compound QLS-278 exhibits inactivation- and concentration-dependent inhibition of macroscopic currents of Nav1.7 channels stably expressed in HEK293 cells with an IC50 of 1.2 {plus minus} 0.2 µM. QLS-278 causes a hyperpolarization shift of the channel inactivation and delays recovery from inactivation, without an obvious effect on voltage-dependent activation. In mouse DRG neurons, QLS-278 suppresses native TTX-sensitive Nav currents and also reduces neuronal firing. Moreover, QLS-278 dose-dependently relieves neuropathic pain induced by spared nerve injury and inflammatory pain induced by formalin without significant alteration of spontaneous locomotor activity in mice. Altogether, our identification of the novel compound QLS-278 may hold developmental potential for the treatment of chronic pain. Significance Statement QLS-278, a novel voltage-gated sodium Nav1.7 channel blocker, inhibits native TTX-S Na+ current and reduces action potential firings in DRG sensory neurons. QLS-278 also exhibits antinociceptive activity in mouse models of pain, thus demonstrating potential for the development of a treatment for chronic pain.

Vilaprisan for the treatment of symptomatic endometriosis: results from a terminated phase 2b randomized controlled trial.

Objective: To evaluate the efficacy and safety of 2 doses of vilaprisan vs. placebo in participants with symptomatic endometriosis. Design: Multicenter, randomized, double-blind, placebo-controlled, parallel-group phase 2b trial (NCT03573336). The initially planned sample size was 315 patients. Recruitment was paused to assess long-term toxicity findings in rodents; although the findings were assessed as likely to be of limited clinical relevance in humans, the study was closed by the sponsor. During the pause, enrolled patients completed 3 or 6 months of treatment per their assigned regimen. Setting: University hospitals, a regional hospital, and a private clinic. Patients: Premenopausal adults with confirmed endometriosis and moderate-to-severe pelvic pain (≥4/10 on a numerical rating scale) were enrolled. Inclusion required protocol adherence, including ≥24 diary entries, and an average pain score of ≥3.5. Intervention: Participants were randomly assigned 1:1:1 to receive vilaprisan (2 mg), vilaprisan (4 mg), or placebo. Main Outcome Measures: The primary outcome was a change in the 7-day mean "worst pain" (per the endometriosis symptom diary item 1) from baseline to month 3. All analyses were descriptive only. Results: Eight participants were randomly assigned to treatment before the study pause: 6 received vilaprisan (4 mg, n = 4 and 2 mg, n = 2), and 2 received placebo. The 6 vilaprisan recipients experienced an improvement in endometriosis-associated pelvic pain, whereas the 2 placebo recipients experienced no change or increased pain; all 8 participants had decreased use of pain medication. Bleeding intensity decreased from baseline in the vilaprisan group. Conclusion: The study findings suggest that vilaprisan may improve outcomes in patients with endometriosis. Further studies in larger populations would be needed to accurately assess treatment effects. Clinical Trial Registration Number: NCT03573336.

Preparation, Optimization, and Anti-Pulmonary Infection Activity of Casein-Based Chrysin Nanoparticles.

Introduction: Chrysin has a wide range of biological activities, but its poor bioavailability greatly limits its use. Here, we attempted to prepare casein (cas)-based nanoparticles to promote the biotransfer of chrysin, which demonstrated better bioavailability and anti-infection activity compared to free chrysin. Methods: Cas-based chrysin nanoparticles were prepared and characterized, and most of the preparation process was optimized. Then, the in vitro and in vivo release characteristics were studied, and anti-pulmonary infection activity was evaluated. Results: The constructed chrysin-cas nanoparticles exhibited nearly spherical morphology with particle size and ζ potential of 225.3 nm and -33 mV, respectively. These nanoparticles showed high encapsulation efficiency and drug-loading capacity of 79.84% ± 1.81% and 11.56% ± 0.28%, respectively. In vitro release studies highlighted a significant improvement in the release profile of the chrysin-cas nanoparticles (CCPs). In vivo experiments revealed that the relative oral bioavailability of CCPs was approximately 2.01 times higher than that of the free chrysin suspension. Further investigations indicated that CCPs effectively attenuated pulmonary infections caused by Acinetobacter baumannii by mitigating oxidative stress and reducing pro-inflammatory cytokines levels, and the efficacy was better than that of the free chrysin suspension. Conclusion: The findings underscore the advantageous bioavailability of CCPs and their protective effects against pulmonary infections. Such advancements position CCPs as a promising pharmaceutical agent and candidate for future therapeutic drug innovations.

Identifying the differentially expressed peripheral blood microRNAs in psychiatric disorders: a systematic review and meta-analysis.

Background: Evidence has suggested that microRNAs (miRNAs) may play an important role in the pathogenesis of psychiatric disorders (PDs), but the results remain inconclusive. We aimed to identify specific differentially expressed miRNAs and their overlapping miRNA expression profiles in schizophrenia (SZ), major depression disorder (MDD), and bipolar disorder (BD), the three major PDs. Methods: The literatures up to September 30, 2023 related to peripheral blood miRNAs and PDs were searched and screened from multiple databases. The differences in miRNA levels between groups were illustrated by the standardized mean difference (SMD) and 95% confidence interval (95% CI). Results: In total, 30 peripheral blood miRNAs were included in the meta-analysis, including 16 for SZ, 12 for MDD, and 2 for BD, each was reported in more than 3 independent studies. Compared with the control group, miR-181b-5p, miR-34a-5p, miR-195-5p, miR-30e-5p, miR-7-5p, miR-132-3p, miR-212-3p, miR-206, miR-92a-3p and miR-137-3p were upregulated in SZ, while miR-134-5p, miR-107 and miR-99b-5p were downregulated. In MDD, miR-124-3p, miR-132-3p, miR-139-5p, miR-182-5p, miR-221-3p, miR-34a-5p and miR-93-5p were upregulated, while miR-144-5p and miR-135a-5p were downregulated. However, we failed to identify statistically differentially expressed miRNAs in BD. Interestingly, miR-132-3p and miR-34a-5p were upregulated in both SZ and MDD. Conclusions: Our study identified 13 differentially expressed miRNAs in SZ and 9 in MDD, among which miR-132-3p and miR-34a-5p were upregulated in both SZ and MDD by systematically analyzing qualified studies. These miRNAs may be used as potential biomarkers for the diagnosis of SZ and MDD in the future. Systematic Review Registration: http://www.crd.york.ac.uk/PROSPERO, identifier CRD42023486982.

Air embolism caused by peripheral superficial vein catheterization: A case report.

BACKGROUND: Air embolization is usually an iatrogenic complication that can occur in both veins and arteries. Intravenous air embolization is mainly associated with large central vein catheters and mechanical ventilation. A 59-year-old woman was sent to our hospital with spontaneous cerebral hemorrhage and treated conservatively with a left forearm peripheral venous catheter infusion drug. After 48 hours, the patient's oxygen saturation decreased to 92 % with snoring breathing. Computer tomography of the head and chest revealed scattered gas in the right subclavian, the right edge of the sternum, the superior vena cava, and the leading edge of the heart shadow. METHODS: She was sent to the intensive care unit for high-flow oxygen inhalation and left-side reclining instantly. As the patient was at an acute stage of cerebral hemorrhage and did not take the Trendelenburg position. RESULTS: The computed tomography (CT) scan after 24 hours shows that the air embolism subsides. CONCLUSION SUBSECTIONS: Air embolism can occur in any clinical scenario, suggesting that medical staff should enhance the ability to identify and deal with air embolism. For similar cases in clinical practice, air embolism can be considered.

Efficacy of Fire-Needle Therapy in Improving Neurological Function Following Cerebral Infarction and Its Effect on Intestinal Flora Metabolites.

Objective: This study was to investigate the mechanism of action and clinical efficacy of fire-needle therapy in improving neurological function in patients with acute cerebral infarction (identified as a wind-phlegm-blood stasis syndrome in traditional Chinese medicine). Methods: We included patients diagnosed with acute cerebral infarction (wind-phlegm-blood stasis syndrome) admitted to the Encephalopathy and Acupuncture Center of the Second Affiliated Hospital of Tianjin University of Chinese Medicine. We randomly allocated them into the treatment and control groups, with 45 cases in each group. Acupuncture treatments that focused on regulating the mind and dredging the collaterals were used in the control group, while the treatment group additionally received fire-needle therapy. Our indicators included the National Institutes of Health Stroke Scale (NIHSS) scores, the Fugl-Meyer Assessment (FMA) scale, peripheral blood tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17), hypersensitivity C-reactive protein (hs-CRP), and intestinal metabolites short-chain fatty acids (SCFAs). We measured these indicators before treatment and 14 days after treatment. Results: The post-treatment NIHSS scores of the two groups were significantly reduced (P < 0.05), and the treatment group showed a more significant decline in the score when compared to the control group (P < 0.05). The treatment group showing significant improvement in the domains of reflex activity, mobility, cooperative movement, and finger movement (P < 0.05). Both groups showed a significant decrease in the IL-17 and hs-CRP levels (P < 0.05), with the treatment group demonstrating a significant declining trend when compared to the control group (P < 0.05). The levels of acetic acid, propionic acid, butyric acid, and valeric acid all increased significantly in the two groups (P < 0.05), with acetic acid and butyric acid increasing significantly in the treatment group when compared to the control group (P < 0.05). Clinical efficacy rate: 78.6% of patients in the treatment group had an excellent rate, whereas it was 30.0% in the control group, and the difference was statistically significant (P < 0.001). Conclusion: Fire-needle therapy was effective in upregulating the SCFA content in patients with acute cerebral infarction (wind-phlegm-blood stasis syndrome), inhibiting the level of the inflammatory response, and improving the recovery of neurological functions. Clinical registration number: Registration website link: https://www.chictr.org.cn. Registration date: 2022/9/27. Registration number: ChiCTR2200064122.

Preparation, characterization and protective effect of chitosan - Tripolyphosphate encapsulated dihydromyricetin nanoparticles on acute kidney injury caused by cisplatin.

Dihydromyricetin (DMY) is a natural dihydroflavonol compound known for its diverse pharmacological benefits. However, its limited stability and bioavailability posed significant challenges for further applications. To address these issues, in this study, an ion crosslinking method was utilized to prepare chitosan nanoparticles that were loaded with DMY. The synthesized chitosan nanoparticles (CS-DMY-NPs) were spherical in shape with particle size and ζ potential of 198.7 nm and 45.05 mV, respectively. Furthermore, in vitro release experiments demonstrated that CS-DMY-NPs had sustained release and protective effects in simulated gastric and intestinal fluids. CS-DMY-NPs exhibited better antioxidant activity by ABTS and DPPH radical scavenging activity than free DMY. In vivo study showed that CS-DMY-NPs alleviated cisplatin-induced kidney damage by inhibiting oxidative stress and proinflammatory cytokines, and had better activity compared to DMY (free). Immunofluorescence data showed that CS-DMY-NPs activated the Nrf2 signaling pathways in a dose-dependent manner to combat cisplatin-induced kidney damage. Our results demonstrate that CS-TPP has good compatibility with DMY, and CS-DMY-NPs exhibited better protective effects against cisplatin-induced acute kidney injury (AKI) than free DMY.

Design, synthesis, and biological evaluation of acyl sulfonamide derivatives with spiro cycles as NaV1.7 inhibitors for antinociception.

Chronic pain, as an unmet medical need, severely impacts the quality of life. The voltage-gated sodium channel NaV1.7 preferentially expressed in sensory neurons of dorsal root ganglia (DRG) serves a promising target for pain therapy. Here, we report the design, synthesis, and evaluation of a series of acyl sulfonamide derivatives targeting Nav1.7 for their antinociceptive activities. Among the derivatives tested, the compound 36c was identified as a selective and potent NaV1.7 inhibitor in vitro and exhibited antinociceptive effects in vivo. The identification of 36c not only provides a new insight into the discovery of selective NaV1.7 inhibitors, but also may hold premise for pain therapy.

Investigating the adverse outcome pathways (AOP) of neurotoxicity induced by DBDPE with a combination of in vitro and in silico approaches.

Current studies have shown an association between DBDPE and neurotoxicity. In this study, the adverse outcome pathway (AOP) and mechanistic analysis of DBDPE-induced neurotoxicity were explored by a combination of in vitro and in silico approaches in SK-N-SH cells. DBDPE-induced oxidative stress caused DNA strand breaks, resulting in the activation of poly (ADP-ribose) (PAR) polymerase-1 (PARP-1). Activation of PARP1 could cause toxic damage in various organ systems, especially in the nervous system. DBDPE-induced apoptosis via the caspase-dependent intrinsic mitochondrial pathway and the PARP1-dependent pathway. Activation of PARP1 by DBDPE was deemed the initiating event, thereby affecting the key downstream biochemical events (e.g., ROS production, DNA damage, membrane potential changes, and ATP reduction), which induced apoptosis. Furthermore, excessive activation of PARP1 was accompanied by the translocation of the apoptosis-inducing factor (AIF), which was associated with PARP1-dependent cell death. The inhibition of PARP1 by PJ34 reduced DBDPE-induced apoptosis and maintained cellular ATP levels. PJ34 also prevented the translocation of AIF from the mitochondria to the nucleus. These findings improve the understanding of the mechanism of DBDPE-induced neurotoxic effects and provide a theoretical basis for the ecological risk of DBDPE.

DBDPE and ZnO NPs synergistically induce neurotoxicity of SK-N-SH cells and activate mitochondrial apoptosis signaling pathway and Nrf2-mediated antioxidant pathway.

Decabromodiphenyl ethane (DBDPE), a new brominated flame retardant, could negatively affect neurobehavior and pose health risks to humans. Humans are also exposed to widely used nanomaterials. This study investigated the combined toxic effects and action types of DBDPE and Zinc oxide nanoparticles (ZnO NPs) on human neuroblastoma SK-N-SH cells and the toxicity mechanisms. DBDPE inhibited the viability of SK-N-SH cells by 21.87% at 25 mg/L. ZnO NPs synergistically exacerbated the toxic effects of DBDPE. DBDPE and ZnO NPs caused excessive ROS production and inhibition of antioxidant enzyme (SOD and GSH) activity in cells, thus causing oxidative cellular damage. Moreover, DBDPE and ZnO NPs caused apoptosis by disrupting mitochondrial kinetic homeostasis, reducing mitochondrial membrane potential (MMP), increasing cytochrome C release and regulating Bax/Bcl-2 and Caspase-3 mRNA and protein expression. DBDPE and ZnO NPs increased the mRNA expression of nuclear factor erythroid 2- related factor (Nrf2) and its downstream genes. The molecular mechanisms revealed that oxidative stress, apoptosis and mitochondrial dysfunction were the critical factors in combined cytotoxicity. The bioinformatics analysis further indicated that co-exposure affected Nrf2 activation, apoptotic factors expression and mitochondrial fusion. The findings enrich the risk perception of neurotoxicity caused by DBDPE and ZnO NPs.

A Rapid and Simple Method for DNA Preparation of Magnaporthe oryzae from Single Rice Blast Lesions for PCR-Based Molecular Analysis.

Rice blast is one of the most destructive diseases of rice worldwide, and the causative agent is the filamentous ascomycete Magnaporthe oryzae. With the successful cloning of more and more avirulence genes from M. oryzae, the direct extraction of M. oryzae genomic DNA from infected rice tissue would be useful alternative for rapid monitoring of changes of avirulence genes without isolation and cultivation of the pathogen. In this study, a fast, low-cost and reliable method for DNA preparation of M. oryzae from a small piece of infected single rice leaf or neck lesion was established. This single step method only required 10 min for DNA preparation and conventional chemical reagents commonly found in the laboratory. The AvrPik and AvrPi9 genes were successfully amplified with the prepared DNA. The expected DNA fragments from 570 bp to 1,139 bp could be amplified even three months after DNA preparation. This method was also suitable for DNA preparation from M. oryzae strains stored on the filter paper. All together these results indicate that the DNA preparation method established in this study is reliable, and could meet the basic needs for polymerase chain reaction-based analysis of M. oryzae.

Two novel lncRNAs AF111167.2 and AL162377.1 targeting miR-21-5p mediated down expression of SYDE2 correlates with poor prognosis and tumor immune infiltration of ccRCC.

Advanced clear cell Renal Cell Carcinoma (ccRCC) is notoriously known for its poor prognosis. Synapse defective protein 1 homolog 2 encoded by the SYDE2 gene is a Rho GTPase-activating protein whose functional tumorigenic significance is still unclear. Recent pan-cancer analysis using the Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) data showed the potential tumor-suppressing effects of SYDE2 in ccRCC. Subsequently, the TCGA, GTEx data, and human protein atlas were employed to assess the correlation between the SYDE2 expression, clinical data, and overall survival (OS) in ccRCC patients. Furthermore, microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) contributing to SYDE2 down expression were identified by expression, relationship, and survival analysis. Eventually, two novel lncRNAs, AL162377.1 and AF111167.2, targeting the miR-21-5p axis, were identified in the SYDE2 upstream non-coding RNAs (ncRNAs)-related pathway in ccRCC. The expression level of SYDE2 highly depends on the tumor immune cell infiltration and immune checkpoint expression. In summary, these data demonstrated that lncRNAs/miRNAs-mediated down-regulation of SYDE2 is related to the tumor immune infiltration. Hence, giving an insight into the prognosis of ccRCC.

Wet End Chemical Properties of a New Kind of Fire-Resistant Paper Pulp Based on Ultralong Hydroxyapatite Nanowires.

In 2014, a new type of the fire-resistant paper based on ultralong hydroxyapatite (HAP) nanowires was reported by the author's research group, which had superior properties and promising applications in various fields, such as high-temperature resistance, fire retardance, heat insulation, electrical insulation, energy, environmental protection, and biomedicine. The wet end chemical properties of the fire-resistant paper pulp are very important for papermaking and mechanical performance of the paper, which play a guiding role in the practical production of the fire-resistant paper. In this paper, the wet end chemical properties of a new kind of fire-resistant paper pulp based on ultralong HAP nanowires are studied for the first time by focusing on the wet end chemical parameters, the effects of these parameters on the properties such as flocculation, retention, draining, and white water circulation of the fire-resistant paper pulp, and their effects on the properties of the as-prepared fire-resistant paper. The experimental results indicated that the wet end chemical properties of the new kind of fire-resistant paper pulp based on ultralong HAP nanowires were unique and entirely different from those of the traditional paper pulp based on plant fibers. The wet end chemical properties of the fire-resistant paper pulp were significantly influenced by the inorganic adhesive and its content, which affected the runnability of the paper machine and the properties of the as-prepared fire-resistant paper. The flocculation properties of the fire-resistant paper pulp based on ultralong HAP nanowires were affected by the conductivity and Zeta potential. The addition of the inorganic adhesive in the fire-resistant paper pulp based on ultralong HAP nanowires could significantly increase the conductivity of the fire-resistant paper pulp, reduce the particle size of paper pulp floccules, and increase the tensile strength of the fire-resistant paper. In addition, the fire-resistant paper pulp based on ultralong HAP nanowires in the presence of inorganic adhesive exhibited excellent antibacterial performance. This work will contribute to and accelerate the commercialization process and applications of the new type of the fire-resistant paper based on ultralong HAP nanowires.

Identification of a Partial and Selective TRPV1 Agonist CPIPC for Alleviation of Inflammatory Pain.

Transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel, predominantly expressed in a subset of peripheral sensory neurons for pain signaling. Topical application of agonist capsaicin for desensitizing TRPV1 currents has been approved for relief of chronic pain. However, the potent TRPV1 capsaicin is not ingestible and even topical capsaicin causes common side effects such as skin irritation, swelling, erythema and pruritus, suggesting that a mild TRPV1 agonist might be helpful for reducing side effects while reliving pain. In this study, we reported on a partial and selective TRPV1 agonist 4-(5-chloropyridin-2-yl)-N-(1H-indazol-6-yl)piperazine-1-carboxamide named CPIPC that was modified based on targeting the residue Arg557, important for conversion between the channel antagonism and agonism. Whole-cell patch clamp recordings indicated a concentration-dependent activation of TRPV1 currents by CPIPC with an EC50 of 1.56 ± 0.13 µM. The maximum efficacy of CPIPC (30 µM) was about 60% of saturated capsaicin (10 µM). Repetitive additions of CPIPC caused TRPV1 current desensitization in both TRPV1-expressing HEK293 cells and dorsal root ganglion (DRG) sensory neurons. Oral administration of CPIPC dose-dependently alleviated inflammatory pain in mice. Further site-directed mutagenesis combined with molecular docking revealed that residue Arg557 is critical for TRPV1 activation by CPIPC. Taken together, we identified a novel partial and selective TRPV1 agonist CPIPC that exhibits antinociceptive activity in mice.

miR-9-5p promotes myogenic differentiation via the Dlx3/Myf5 axis.

MicroRNAs play an important role in myogenic differentiation, they bind to target genes and regulate muscle formation. We previously found that miR-9-5p, which is related to bone formation, was increased over time during the process of myogenic differentiation. However, the mechanism by which miR-9-5p regulates myogenic differentiation remains largely unknown. In the present study, we first examined myotube formation and miR-9-5p, myogenesis-related genes including Dlx3, Myod1, Mef2c, Desmin, MyoG and Myf5 expression under myogenic induction. Then, we detected the expression of myogenic transcription factors after overexpression or knockdown of miR-9-5p or Dlx3 in the mouse premyoblast cell line C2C12 by qPCR, western blot and myotube formation under myogenic induction. A luciferase assay was performed to confirm the regulatory relationships between not only miR-9-5p and Dlx3 but also Dlx3 and its downstream gene, Myf5, which is an essential transcription factor of myogenic differentiation. The results showed that miR-9-5p promoted myogenic differentiation by increasing myogenic transcription factor expression and promoting myotube formation, but Dlx3 exerted the opposite effect. Moreover, the luciferase assay showed that miR-9-5p bound to the 3'UTR of Dlx3 and downregulated Dlx3 expression. Dlx3 in turn suppressed Myf5 expression by binding to the Myf5 promoter, ultimately inhibiting the process of myogenic differentiation. In conclusion, the miR-9-5p/Dlx3/Myf5 axis is a novel pathway for the regulation of myogenic differentiation, and can be a potential target to treat the diseases related to muscle dysfunction.

Low doses of niclosamide and quinacrine combination yields synergistic effect in melanoma via activating autophagy-mediated p53-dependent apoptosis.

Malignant melanoma is a highly aggressive, malignant, and drug-resistant tumor. It lacks an efficient treatment approach. In this study, we developed a novel anti-melanoma strategy by using anti-tapeworm drug niclosamide and anti-malarial drug quinacrine, and investigated the molecular mechanism by in vitro and in vivo assays. Meanwhile, other types of tumor cells, immortalized epithelial cells and bone marrow mesenchymal stem cells were used to evaluate the universal role of anti-cancer and safety of the strategy. The results showed, briefly, an exposure to niclosamide and quinacrine led to an increased apoptosis-related protein p53, cleaved caspase-3 and cleaved PARP and autophagy-related protein LC3B expression, and a decreased expression of autophagy-related protein p62, finally leading to cell apoptosis and autophage. After inhibiting autophagy by Baf-A1, flow cytometry and western blot showed that the expression of apoptosis-related proteins was down-regulated and the number of apoptotic cells decreased. Subsequently, in the siRNA-mediated p53 knockdown cells, the expression of apoptosis-related proteins and the number of apoptotic cells were also reduced, while the expression of autophagy-related proteins including LC3B, p62 did not change significantly. To sum up, we developed a new, safe strategy for melanoma treatment by using low doses of niclosamide and quinacrine to treat melanoma; and found a novel mechanism by which the combination application of low doses of niclosamide and quinacrine exerts an efficient anti-melanoma effect through activation of autophagy-mediated p53-dependent apoptosis. The novel strategy was verified to exert a universal anti-cancer role in other types of cancer.

Streptococcus mutans-associated bacteria in dental plaque of severe early childhood caries.

BACKGROUND: Streptococcus mutans (S. mutans) is a potential pathogenic bacteria of dental caries. However, the level of S. mutans is low in some children with severe early childhood caries (SECC). AIM: To evaluate the effect of S. mutans level on dental microbiome and cariogenesis. METHODS: The oral microbiota was compared between caries-free group (CF) and SECC group.16S rRNA gene sequencing was used for S. mutans level bacterial community analysis. The candidate bacteria that were closely related with S. mutans abundance were identified and confirmed by absolute quantitative real-time PCR in clinical dental plaque samples from CF and SECC groups. RESULTS: Through in-depth analysis of dental plaque microorganism, Leptotrichia, Selenomonas and Prevotella_7 were found in the S. mutans-low group (p < 0.05) and Porphyromonas, Selenomonas_3 were found in the S. mutans-high group (p < 0.05). Through quantitative real-time PCR, Leptotrichia, Selenomonas and Prevotella_7 were identified as the potential biomarkers of SECC when S. mutans was at a low level. CONCLUSION: Leptotrichia, Selenomonas and Prevotella_7 are identified as potential biomarkers in SECC with a low abundance or without S. mutans. Our study may shed light on the understanding of caries occurrence in SECC with low abundance of S. mutans. ABBREVIATIONS: S. mutans, Streptococcus mutans; CF, caries-free; SECC, severe early childhood caries; ECC, early childhood caries; rRNA, ribosome RNA; qPCR, Quantitative real-time PCR; OTUs, operational taxonomic units; ANOVA, analysis of variance; LDA, Linear discriminant analysis; LEfSe, Linear discriminant analysis effect size; COG, Groups of proteins; NMDS, Non-MetricMulti-Dimensional Scaling; IL-1ß, interleukin -1ß; IL-6, interleukin-6; IL-8, interleukin-8; IL-10, interleukin-10.

DIC/Oxyma-based accelerated synthesis and oxidative folding studies of centipede toxin RhTx.

Coupling reagents play crucial roles in the iterative construction of amide bonds for the synthesis of peptides and peptide-based derivatives. The novel DIC/Oxyma condensation system featured with the low risk of explosion displayed remarkable abilities to inhibit racemization, along with efficient coupling efficiency in both manual and automated syntheses. Nevertheless, an ideal reaction molar ratio in DIC/Oxyma condensation system and the moderate reaction temperature by manual synthesis remain to be further investigated. Herein, the synthetic efficiencies of different reaction ratios between DIC and Oxyma under moderate reaction temperature were systematically evaluated. The robustness and efficiency of DIC/Oxyma condensation system are validated by the rapid synthesis of linear centipede toxin RhTx. Different folding strategies were applied for the construction of disulfide bridges in RhTx, which was further confirmed in assays of circular dichroism and patch-clamp electrophysiology evaluation. This work establishes the DIC/Oxyma-based accelerated synthesis of peptides under moderate condensation conditions, which is especially useful for the manual synthesis of peptides. Besides, the strategy presented here provides robust technical supports for the large-scale synthesis and oxidative folding of RhTx.