5-methylcytosine modification by Plasmodium NSUN2 stabilizes mRNA and mediates the development of gametocytes.

5-methylcytosine (m5C) is an important epitranscriptomic modification involved in messenger RNA (mRNA) stability and translation efficiency in various biological processes. However, it remains unclear if m5C modification contributes to the dynamic regulation of the transcriptome during the developmental cycles of Plasmodium parasites. Here, we characterize the landscape of m5C mRNA modifications at single nucleotide resolution in the asexual replication stages and gametocyte sexual stages of rodent (Plasmodium yoelii) and human (Plasmodium falciparum) malaria parasites. While different representations of m5C-modified mRNAs are associated with the different stages, the abundance of the m5C marker is strikingly enhanced in the transcriptomes of gametocytes. Our results show that m5C modifications confer stability to the Plasmodium transcripts and that a Plasmodium ortholog of NSUN2 is a major mRNA m5C methyltransferase in malaria parasites. Upon knockout of P. yoelii nsun2 (pynsun2), marked reductions of m5C modification were observed in a panel of gametocytogenesis-associated transcripts. These reductions correlated with impaired gametocyte production in the knockout rodent malaria parasites. Restoration of the nsun2 gene in the knockout parasites rescued the gametocyte production phenotype as well as m5C modification of the gametocytogenesis-associated transcripts. Together with the mRNA m5C profiles for two species of Plasmodium, our findings demonstrate a major role for NSUN2-mediated m5C modifications in mRNA transcript stability and sexual differentiation in malaria parasites.

Genome-wide landscape of ApiAP2 transcription factors reveals a heterochromatin-associated regulatory network during Plasmodium falciparum blood-stage development.

Heterochromatin-associated gene silencing controls multiple physiological processes in malaria parasites, however, little is known concerning the regulatory network and cis-acting sequences involved in the organization of heterochromatin and how they modulate heterochromatic gene expression. Based on systematic profiling of genome-wide occupancy of eighteen Apicomplexan AP2 transcription factors by ChIP-seq analysis, we identify and characterize eight heterochromatin-associated factors (PfAP2-HFs), which exhibit preferential enrichment within heterochromatic regions but with differential coverage profiles. Although these ApiAP2s target euchromatic gene loci via specific DNA motifs, they are likely integral components of heterochromatin independent of DNA motif recognition. Systematic knockout screenings of ApiAP2 factors coupled with RNA-seq transcriptomic profiling revealed three activators and three repressors of heterochromatic gene expression including four PfAP2-HFs. Notably, expression of virulence genes is either completely silenced or significantly reduced upon the depletion of PfAP2-HC. Integrated multi-omics analyses reveal autoregulation and feed-forward loops to be common features of the ApiAP2 regulatory network, in addition to the occurrence of dynamic interplay between local chromatin structure and ApiAP2s in transcriptional control. Collectively, this study provides a valuable resource describing the genome-wide landscape of the ApiAP2 family and insights into functional divergence and cooperation within this family during the blood-stage development of malaria parasites.

A new marker constructed from immune-related lncRNA pairs can be used to predict clinical treatment effects and prognosis: in-depth exploration of underlying mechanisms in HNSCC.

BACKGROUND: Long non-coding RNA (lncRNA) plays a vital role in tumor proliferation, migration, and treatment. Since it is challenging to standardize the gene expression levels detected by different platforms, the signatures composed of many immune-related single lncRNAs are still inaccurate. Utilizing a gene pair formed of two immune-related lncRNAs and strategically assigning values can effectively meet the demand for a higher-accuracy dual biomarker combination. METHODS: Co-expression and differential expression analyses were performed on immune genes and lncRNAs data from The Cancer Genome Atlas and the ImmPort database to obtain differentially expressed immune-related lncRNAs for pairwise pairing. The prognostic-related differentially expressed immune-related lncRNAs (PR-DE-irlncRNAs) pairs were then identified by univariate Cox regression and used for lasso regression to construct a prognostic model. Various methods were used to validate the predictive prognostic performance of the model. Additionally, we explored the potential guiding value of the model in immunotherapy and chemotherapy and constructed a nomogram suitable for efficient prognosis prediction. Mechanistic exploration of anti-tumor immunity and mutational perspectives are also included. We also analyzed the correlation between the model and immune checkpoint inhibitors (ICIs)-related, N6-methyadenosine (m6A)-related, and multidrug resistance genes. RESULTS: We used a total of 20 pairs of PR-DE-irlncRNAs to create a prognosis model. Quantitative real-time polymerase chain reaction experiments further verified the abnormal expression of 11 lncRNAs in HNSCC cells. Various methods have confirmed the excellent performance of the model in predicting patient prognosis. We reasoned that lncRNAs/TP53 mutation might play a positive/negative anti-tumor role through the immune system by multi-perspective analyses. Finally, it was found that the prognostic model was closely related to immunotherapy and chemotherapy as well as the expression of ICIs/m6A/multidrug resistance-related genes. CONCLUSION: The prognostic model performs excellently in predicting the prognosis of patients and provides the potential value of practical guidance for treatment.

The cryptic unstable transcripts are associated with developmentally regulated gene expression in blood-stage Plasmodium falciparum.

The tight gene expression regulation controls the development and pathogenesis of human malaria parasite Plasmodium falciparum throughout the complex life cycle. Recent studies have revealed the pervasive nascent transcripts in the genome of P. falciparum, suggesting the existence of a hidden transcriptome involved in the dynamic gene expression. However, the landscape and related biological functions of nascent non-coding RNAs (ns-ncRNAs) are still poorly explored. Here we profiled the transcription dynamics of nascent RNAs by rRNA-depleted and stranded RNA sequencing over the course of 48-h intraerythrocytic developmental cycle (IDC). We identified the genome-wide sources of a total of 2252 ns-ncRNAs, mostly originating from intergenic and untranslated regions of annotated genes. By integrating the nascent RNA abundances with ATAC-seq and ChIP-seq analysis, we uncovered the euchromatic microenvironment surrounding the ns-ncRNA loci, and revealed a positive correlation between ns-ncRNAs and corresponding mRNA abundances. Finally, by gene knock-down strategy, we showed that the cooperation of RNA exosome catalytic subunit PfDis3 and PfMtr4 cofactor played a major role in ns-ncRNAs degradation. Collectively, this study contributes to understanding of the potential roles of short-lived nascent ncRNAs in regulating gene expression in malaria parasites.

Combined non-intubated anaesthesia and paravertebral nerve block in comparison with intubated anaesthesia in children undergoing video-assisted thoracic surgery.

BACKGROUND: This study is to investigate if non-intubated anaesthesia combined with paravertebral nerve block (PVNB) can enhance recovery in children undergoing video-assisted thoracic surgery (VATS). METHODS: A randomized controlled trial including 60 patients aged 3 to 8 years old who underwent elective VATS was performed. They were randomly assigned to receive non-intubated anaesthesia combined with PVNB or general anaesthesia with tracheal intubation (1:1 ratio). The primary outcome was the length of postoperative in-hospital stay. The secondary outcomes included emergence time, the incidence of emergence delirium, time to first feeding, time to first out-of-bed activity, pain score and in-hospital complications. RESULTS: The non-intubated group had shorter postoperative in-hospital stay than the control group (4 days [IQR, 4-6] vs 5 days [IQR, 5-8], 95% CI 0-2; P = .013). When compared to the control group, the incidence of emergence delirium (odds ratio [OR] 3.39, 95% CI 1.01-11.41; P = .043), emergence time, duration in the PACU, time to first eating food, first out-of-bed activity, pain score and consumption of sufentanil (at 6 and 12 hours after surgery) were decreased in the intervention group. In contrast, the incidence of airway complications was higher in the control than the intervention group (27.6% vs 6.9%, P = .037). There was no statistical significance in the occurrence of PONV, pneumothorax and other complications between the two groups. CONCLUSIONS: Non-intubated anaesthesia combined with PVNB enhances recovery in paediatric patients for video-assisted thoracic surgery although further multi-centre study is needed.

Effect of caudal ketamine on minimum local anesthetic concentration of ropivacaine in children: a prospective randomized trial.

BACKGROUND: Caudal ketamine has been shown to provide an effective and prolonged post-operative analgesia with few adverse effects. However, the effect of caudal ketamine on the minimum local anesthetic concentration (MLAC) of ropivacaine for intra-operative analgesia is unclear. METHODS: One hundred and sixty-nine children were randomized to five groups: Group C (caudal ropivacaine only), Group K0.25 (caudal ropivacaine plus 0.25 mg/kg ketamine), Group K0.5 (caudal ropivacaine plus 0.5 mg/kg ketamine), Group K0.75 (caudal ropivacaine plus 0.75 mg/kg ketamine), and Group K1.0 (caudal ropivacaine plus 1.0 mg/kg ketamine). The primary outcome was the MLAC values of ropivacaine with/without ketamine for caudal block. RESULTS: The MLAC values of ropivacaine were 0.128% (0.028%) in the control group, 0.112% (0.021%) in Group K0.25, 0.112% (0.018%) in Group K0.5, 0.110% (0.019%) in Group K0.75, and 0.110% (0.020%) in Group K1.0. There were no significant differences among the five groups for the MLAC values (p = 0.11). During the post-operative period the mean durations of analgesia were 270, 381, 430, 494, and 591 min in the control, K0.25, K0. 5, K0.75, and K1.0 groups respectively, which shown that control group is significantly different from all ketamine groups. Also there were significant differences between K0.25 and K0.75 groups, and between K1.0 groups and the other ketamine groups. CONCLUSIONS: Adding caudal ketamine to ropivacaine prolong the duration of post-operative analgesia; however, it does not decrease the MLAC of caudal ropivacaine for intra-operative analgesia in children. CLINICAL TRIAL REGISTRATION: ChiCTR-TRC-13003492. Registered on 13 August 2013.

Disruption of the RNA exosome reveals the hidden face of the malaria parasite transcriptome.

Antisense transcription emerges as a key regulator of important biological processes in the human malaria parasite Plasmodium falciparum. RNA-processing factors, however, remain poorly characterized in this pathogen. Here, we purified the multiprotein RNA exosome complex of malaria parasites by affinity chromatography, using HA-tagged PfRrp4 and PfDis3 as the ligands. Seven distinct core exosome subunits (PfRrp41, PfMtr3, PfRrp42, PfRrp45, PfRrp4, PfRrp40, PfCsl4) and two exoribonuclease proteins PfRrp6 and PfDis3 are identified by mass spectrometry. Western blot analysis detects Dis3 and Rrp4 predominantly in the cytoplasmic fraction during asexual blood stage development. An inducible gene knock out of the PfDis3 subunit reveals the upregulation of structural and coding RNA, but the vast majority belongs to antisense RNA. Furthermore, we detect numerous types of cryptic unstable transcripts (CUTs) linked to virulence gene families including antisense RNA in the rif gene family. Our work highlights the limitations of steady-state RNA analysis to predict transcriptional activity and link the RNA surveillance machinery directly with post-transcriptional control and gene expression in malaria parasites.

Relationship Between Body Mass Index and Spread of Spinal Anesthsia in Pregnant Women: A Randomized Controlled Trial.

BACKGROUND The effect of body mass index (BMI) on the spread of spinal anesthesia is not completely clear. The aim of this study was to determine the dose requirements of ropivacaine and the incidence of hypotension in pregnant women with different BMIs during cesarean delivery. MATERIAL AND METHODS In this double-blind study, 405 women undergoing elective cesarean delivery were allocated to group S (BMI <25), group M (25 ≤BMI <30), or group L (BMI ≥30). Women in each group were further assigned to receive 7, 8, 9, 10, 11, 12, 13, 14, or 15 mg of spinal ropivacaine. RESULTS The ED50 and ED95 values of ropivacaine were 9.487 mg and 13.239 mg in Group S, 9.984 mg and 13.737 mg in Group M, and 9.067 mg and 12.819 mg in Group L. There were no significant differences among the 3 groups (p=0.915). Group L had a higher incidence of hypotension and a greater change in MAP after spinal anesthesia compared to the other 2 groups, and also required more doses of ephedrine than the other 2 groups when a dose of 15 mg ropivacaine was used. The incidence of hypotension had a positive correlation with the dose of ropivacaine (OR=1.453, p<0.001) and gestational age (OR=1.894, p<0.001). CONCLUSIONS Spinal ropivacaine dose requirements were similar in the normal BMI range. However, higher doses of spinal ropivacaine were associated with an increased incidence and severity of hypotension in obese patients compared with that in non-obese patients.

Median Effective Dose of Intranasal Dexmedetomidine for Rescue Sedation in Pediatric Patients Undergoing Magnetic Resonance Imaging.

BACKGROUND: The median effective dose (ED50) of intranasal dexmedetomidine after failed chloral hydrate sedation has not been described for children. This study aims to determine the ED50 of intranasal dexmedetomidine for rescue sedation in children aged 1 to 36 months, who were inadequately sedated by chloral hydrate administration during magnetic resonance imaging (MRI). METHODS: This study was performed on 120 children, who were 1 to 36 months old and underwent MRI scanning. Intranasal dexmedetomidine was administered as a rescue sedative to children not adequately sedated after the initial oral dose of chloral hydrate (50 mg/kg). Children were stratified into four age groups. ED50 values were estimated from the up-and-down method of Dixon and Massey and probit regression. Other variables included induction time, time to wake up, vital signs, oxygen saturation, MRI scanning time, and recovery characteristics. RESULTS: ED50 of intranasal dexmedetomidine for rescue sedation was 0.4 µg/kg (95% CI, 0.34 to 0.50) in children aged 1 to 6 months, 0.5 µg/kg (95% CI, 0.48 to 0.56) in children aged 7 to 12 months, 0.9 µg/kg (95% CI, 0.83 to 0.89) in children aged 13 to 24 months, and 1.0 µg/kg (95% CI, 0.94 to 1.07) in children aged 25 to 36 months. There were no significant differences in sedation induction time or time to wake up between the different age groups. Additionally, no significant adverse hemodynamic or hypoxemic effects were noted. CONCLUSIONS: The authors determined the ED50 for rescue sedation using intranasal dexmedetomidine after failed chloral hydrate sedation in children. It was found that ED50 increases with advancing age during the first 3 yr of life.

Comparison of rescue techniques for failed chloral hydrate sedation for magnetic resonance imaging scans--additional chloral hydrate vs intranasal dexmedetomidine.

BACKGROUND: Chloral hydrate, a commonly used sedative in children during noninvasive diagnostic procedures, is associated with side effects like prolonged sedation, paradoxical excitement, delirium, and unpleasant taste. Dexmedetomidine, a highly selective α-2 agonist, has better pharmacokinetic properties than chloral hydrate. We conducted this prospective, double-blind, randomized controlled trial to evaluate efficacy of intranasal dexmedetomidine with that of a second oral dose of chloral hydrate for rescue sedation during magnetic resonance imaging (MRI) studies in infants. METHODS: One hundred and fifty infants (age group: 1-6 months), who were not adequately sedated after initial oral dose of 50 mg · kg(-1) chloral hydrate, were randomly divided into three groups with the following protocol for each group. Group C: second oral dose chloral hydrate 25 mg · kg(-1); Group L and Group H: intranasal dexmedetomidine in a dosage of 1 and 2 mcg · kg(-1), respectively. Status of sedation, induction time, time to wake up, vital signs, oxygen saturation, and recovery characteristics were recorded. RESULTS: Successful rescue sedation in Groups C, L, and H were achieved in 40 (80%), 47 (94%), and 49 (98%) of infants, respectively, on an intention to treat analysis, and the proportion of infants successfully sedated in Group H was more than that of Group L (P ˂ 0.01). There were no significant differences in sedation induction time; however, the time to wake up was significantly shorter in Group L as compared to that in Group C or H (P < 0.01). No significant adverse hemodynamic or hypoxemic effects were observed in the study. CONCLUSION: Intranasal dexmedetomidine induced satisfactory rescue sedation in 1- to 6-month-old infants during MRI study, and appears to cause sedation in a dose-dependent manner.

[Research advances in s48/45 protein family of Plasmodium falciparum].

The s48/45 domain is a beta-sandwich fold domain, and usually includes 6-cysteines. Proteins containing s48/45 domain exist in each developmental stages of Plasmodium parasite, and play an important role in the invasion into host cells. According to the features and functions of the protein molecule, members of the s48/45 protein family could be used as the vaccine candidates against Plasmodium falciparum in different stages. This article focuses on the research progress of P. falciparum protein family containing s48/45 domain.

Prophylactic Epidural Blood Patch or Prophylactic Epidural Infusion of Hydroxyethyl Starch in Preventing Post-Dural Puncture Headache - A Retrospective Study.

BACKGROUND: Post-dural puncture headache (PDPH) is particularly likely to happen in patients under obstetric care due to an unintentional dural puncture (UDP). There is as yet no ideal strategy for preventing UDP-induced PDPH. OBJECTIVES: The primary objective of this study was to assess whether a prophylactic epidural blood patch (EBP) or prophylactic epidural infusion of hydroxyethyl starch (HES) is effective in preventing PDPH for parturients with UDP compared with conservative treatments. STUDY DESIGN: Retrospective analysis from a single center's inpatient data. SETTING: Department of Anesthesiology at a single center. METHODS: A retrospective study was conducted of a single center's inpatient data from January 2017 through March 2020. The study included parturients with UDP during neuraxial anesthesia. The interventions of UDP included conservative treatment, prophylactic EBP, and prophylactic epidural infusion of HES. The incidence of PDPH, the use of intravenous aminophylline, therapeutic EBP, symptom onset, duration of headache, and duration of hospital stay were compared. RESULTS: A total of 85 patients were analyzed. The incidences of PDPH were 84%, 52.6% and 54.5% with conservative, prophylactic EBP, and prophylactic epidural HES treatments, respectively. Compared with the conservative treatment, prophylactic EBP and prophylactic epidural HES treatment significantly reduced the incidence of PDPH (P < 0.05). No significant difference was found between the prophylactic EBP and prophylactic epidural HES groups. Compared with the conservative treatment group, therapeutic EBP was significantly less used in the prophylactic EBP and prophylactic epidural HES groups (P < 0.05). Prophylactic EBP shortened the length of hospital stay of parturients with UDP (P < 0.05) while prophylactic epidural HES showed no statistical difference compared with conservative treatment. No severe complications, such as central nervous system and puncture site infection or nerve injury, were found in those patients. LIMITATIONS: Retrospective nature and single center data with a relatively small sample size. CONCLUSIONS: Prophylactic management with EBP and epidural infusion of HES has an effect in preventing the occurrence of PDPH; prophylactic EBP significantly shortened hospital stay length in parturients with UDP. KEY WORDS: Unintentional dural puncture, epidural blood patch, hydroxyethyl starch, post-dural puncture headache, parturient.

Role of ferroptosis in esophageal cancer and corresponding immunotherapy.

Esophageal cancer (EC) is one of the most common digestive system malignancies in the world. The combined modality treatment of EC is usually surgery and radiation therapy, however, its clinical efficacy for advanced patients is relatively limited. Ferroptosis, a new type of iron-dependent programmed cell death, is different from apoptosis, necrosis and autophagy. In recent years, many studies have further enlightened that ferroptosis plays an essential role in the occurrence, development and metastasis of tumors. Targeting ferroptosis stimulates a new direction for further exploration of oncologic treatment regimens. Furthermore, ferroptosis has a critical role in the immune microenvironment of tumors. This paper reviews the mechanism of ferroptosis and the ferroptosis research progress in the treatment of EC. We further elaborate the interaction between ferroptosis and immunotherapy, and the related mechanisms of ferroptosis participation in the immunotherapy of EC, so as to provide new directions and ideas for the treatment of EC.

Association analysis between endothelial function related factors and coronary artery stenosis degree in coronary heart disease patients with type 2 diabetes mellitus.

OBJECTIVE: To investigate the relationship between soluble intercellular adhesion molecule (sICAM-1), vascular endothelial cell adhesion molecule (VCAM-1), monocytes chemotactic protein (MCP-1), von Willebrand factor (vWF), and coronary artery stenoses degree in coronary heart disease (CHD) within type 2 diabetes mellitus (T2DM) patients. METHODS: A total of 92 subjects were treated with coronary angiography (CAG), including 62 subjects with CHD. The individuals were divided into three groups, group A (32 patients with CHD and T2DM), group B (30 patients with CHD but no T2DM) and group C (30 patients with no CHD and T2DM). All patients were treated with a Gensini coronary angiography check. The correlations between sICAM-1, VCAM-1, MCP-1 and vWF in peripheral blood and coronary artery stenosis degree were analyzed. RESULTS: The average score of coronary artery stenosis degree was 30.75 +/-12.67 in group A, which was significantly higher than group B (11.20 +/-7.51) and group C (2.40 +/- 1.23) (p < 0.01). The mean levels of sICAM-1, VCAM-1, MCP-1 and vWF in serum showed that group A was significantly higher than group B and group C (p < 0.01), and also that group B was higher than group C. There were significant positive correlations between the degree of coronary artery stenosis and the mean level of sICAM-1, VCAM-1, MCP-1, vWF in group A (p < 0.01), but these were not shown in group B and group C (p > 0.05). CONCLUSIONS: Association analysis shown that the level of sICAM-1, VCAM-1, MCP-1 and vWF elevated in CHD with T2DM patients. Vascular endothelial dysfunction could be caused to the coronary artery stenosis pathophysiological process. Results from this study suggested that sICAM-1, VCAM-1, MCP-1 and vWF may contribute to the occurrence and development of vascular lesions in T2DM. These endothelial function related factors could be acceptable as a prediction and testing index of vascular complications in T2DM.

An Integrated Immune-Related Bioinformatics Analysis in Glioma: Prognostic Signature's Identification and Multi-Omics Mechanisms' Exploration.

As the traditional treatment for glioma, the most common central nervous system malignancy with poor prognosis, the efficacy of high-intensity surgery combined with radiotherapy and chemotherapy is not satisfactory. The development of individualized scientific treatment strategy urgently requires the guidance of signature with clinical predictive value. In this study, five prognosis-related differentially expressed immune-related genes (PR-DE-IRGs) (CCNA2, HMGB2, CASP3, APOBEC3C, and BMP2) highly associated with glioma were identified for a prognostic model through weighted gene co-expression network analysis, univariate Cox and lasso regression. Kaplan-Meier survival curves, receiver operating characteristic curves and other methods have shown that the model has good performance in predicting the glioma patients' prognosis. Further combined nomogram provided better predictive performance. The signature's guiding value in clinical treatment has also been verified by multiple analysis results. We also constructed a comprehensive competing endogenous RNA (ceRNA) regulatory network based on the protective factor BMP2 to further explore its potential role in glioma progression. Numerous immune-related biological functions and pathways were enriched in a high-risk population. Further multi-omics integrative analysis revealed a strong correlation between tumor immunosuppressive environment/IDH1 mutation and signature, suggesting that their cooperation plays an important role in glioma progression.

Prolonged sevoflurane exposure causes abnormal synapse development and dysregulates beta-neurexin and neuroligins in the hippocampus in neonatal rats.

BACKGROUND: The underlying molecular mechanisms of the excitatory/inhibitory (E/I) imbalance induced by sevoflurane exposure to neonates remain poorly understood. This study aimed to investigate the long-term effects of prolonged sevoflurane exposure to neonatal rats during the peak period of synaptogenesis on the changes of trans-synaptic neurexin-neuroligin interactions, synaptic ultrastructure in the hippocampus and cognition. METHODS: A total of 30 rat pups at postnatal day (P) 7 was randomly divided into two groups: the control group (exposed to 30 % oxygen balanced with nitrogen) and the sevoflurane group (exposed to 2.5 % sevoflurane plus 30 % oxygen balanced with nitrogen) for 6 h. Neurocognitive behaviors were assessed with the Open field test at P23-25 and the Morris water maze test at P26-30. The expression of ß-neurexin (ß-NRX), N-methyl-d-aspartate receptor 2 subunit (NR2A and NR2B), neuroligin-1 (NLG-1), neuroligin-2 (NLG-2), postsynaptic density protein-95 (PSD-95), α1-subunit of the γ-aminobutyric acid A receptor (GABAAα1) and gephyrin in the hippocampus at P30 were measured by Western blot. The ultrastructure of synapses was examined under electron microscope. RESULTS: Prolonged sevoflurane exposure at P7 resulted in cognitive deficiency in adolescence, as well as the downregulation of ß-NRX, NR2A, NR2B, NLG-1, and PSD-95, and the upregulation of GABAAα1, NLG-2, and gephyrin in the hippocampal CA3 region. Sevoflurane anesthesia also increased the number of symmetric synapses in the hippocampus. CONCLUSIONS: Prolonged sevoflurane exposure during the brain development leads to cognitive deficiency and disproportion of excitatory/inhibitory synapses which may be caused by dysregulated expression of synaptic adhesion molecules of ß-NRX and neuroligins.

Co-existing polysaccharides affect the systemic exposure of major bioactive ingredients in Chang-Kang-Fang, a multi-herb prescription for treatment of irritable bowel syndrome.

ETHNOPHARMACOLOGICAL RELEVANCE: Chang-Kang-Fang (CKF) is a traditional Chinese herbal formula used for treatment of irritable bowel syndrome (IBS) in China. Decoction is the administration form of CKF in clinical practice. Previously, CKF has been confirmed with activities of releasing pain and reversing disorders of intestinal propulsion. And alkaloids, monoglycosides, chromones were found as the main bioactive components potentially contributing to the efficacy of CKF. Polysaccharide was also a major constituent in CKF. But if and how polysaccharides influence the systemic exposure of bioactive components in CKF is unknown. AIM OF THE STUDY: In this study, we aimed to demonstrate the contribution of the co-existed polysaccharides on the systemic exposure of the major bioactive components from CKF in normal and IBS model rats. MATERIALS AND METHODS: An UPLC-TQ-MS with multiple reaction monitoring (MRM) scan method was developed and validated for quantifying six major small molecular bioactive ingredients of CKF in the plasma samples, including magnoflorine (MAG), berberine (BBR), albiflorin (ALB), paeoniflorin (PAE), 5-O-methylvisamminol (5-OM) and prim-O-glucosylcimifugin (POG). The rats received CKF decoction (CKF) and CKF small molecule portion (knockout of polysaccharides, CKFSM), respectively. IBS model rats were induced by daily bondage and gavage of Sennae Folium decoction (derived from the leaf of Cassia angustifolia Vahl). The effects of the co-existing polysaccharides on the pharmacokinetic parameters of six small molecular bioactive components in normal and IBS model rats were systematically evaluated. The potential gut microbiota involved mechanisms of the effects was validated by broad-spectrum antibiotic (ABX) treatment. RESULTS: The selectivity, precision, accuracy, recovery and matrix effect of the established quantification method were all within acceptable limits of biological sample. In normal rats, the co-existing polysaccharides significantly reduced the AUC(0-t) of MAG and PAE compared with CKFSM group. The Cmax and AUC(0-t) of other four compound were not influenced by co-existing polysaccharides. However, in IBS model rats, compared with CKFSM group, the Cmax and AUC(0-t) of the six ingredients significantly increased in CKF group. For CKF + ABX group, the Cmax of six ingredients decreased significantly when compared with CKF group, and the AUC(0-t) of MAG, BBR, ALB, PAE also reduced with significant differences. CONCLUSIONS: A reliable and sensitive UPLC-TQ-MS method was successfully developed and validated for evaluating influence of co-existing polysaccharides on pharmacokinetic behavior of six major small molecules components in CKF. The co-existing polysaccharides enhanced the systemic exposure of six bioactive small molecules in CKF under IBS pathological state potentially via gut microbiota involvement.

Integrating multiple-chromatographic approaches to evaluate chemical consistency of Chang-Kang-Fang preparations from mixed-herb decoction and combined single-herb decoction.

Chang-Kang-Fang formula (CKF), a multi-herbs traditional Chinese medicine (TCM) prescription for treating irritable bowel syndrome (IBS), has been clinically applied in the traditional form of mixed-herb decoction (MHD), or in the modern form of combined single-herb decoction (cSHD, so called dispensing granule decoction) in the near decades, but the chemical consistency between the MHD and cSHD is still unknown. Herein, a new strategy by integrating multiple-chromatographic approaches to characterize both polysaccharides and small molecules was developed to compare the chemical consistency between MHD and cSHD. Sixteen small molecules were simultaneously qualified and quantified by UPLC-QTOF-MS/MS, the molecular weight distribution of polysaccharides was characterized by HPGPC-ELSD, while the monosaccharide composition and total saccharides content were determined by HPLC-PDA and UV-VIS, respectively. It was found that the molecular weight range and monosaccharide composition of polysaccharides, as well as the composition of small molecules, were identical between MHD and cSHD. However, the contents of berberine, epiberberine, coptisine, palmatine, albiflorin and paeoniflorin in MHD were significantly lower than those in cSHD, whereas the content of polysaccharides in MHD was higher than that in cSHD, indicating that there is a significant difference in the quality between MHD and cSHD, in particular for the relative contents of major small molecules and polysaccharides. Whether or not these quality variations affect the efficacy and safety of CKF deserves further investigation.

PfAP2-EXP2, an Essential Transcription Factor for the Intraerythrocytic Development of Plasmodium falciparum.

Plasmodium falciparum undergoes a series of asexual replications in human erythrocytes after infection, which are effective targets for combatting malaria. Here, we report roles of an ApiAP2 transcription factor PfAP2-EXP2 (PF3D7_0611200) in the intraerythrocytic developmental cycle of P. falciparum. PfAP2-EXP2 conditional knockdown resulted in an asexual growth defect but without an appreciable effect on parasite morphology. Further ChIP-seq analysis revealed that PfAP2-EXP2 targeted genes related to virulence and interaction between erythrocytes and parasites. Especially, PfAP2-EXP2 regulation of euchromatic genes does not depend on recognizing specific DNA sequences, while a CCCTAAACCC motif is found in its heterochromatic binding sites. Combined with transcriptome profiling, we suggest that PfAP2-EXP2 is participated in the intraerythrocytic development by affecting the expression of genes related to cell remodeling at the schizont stage. In summary, this study explores an ApiAP2 member plays an important role for the P. falciparum blood-stage replication, which suggests a new perspective for malaria elimination.

Systematic metabolite profiling of N-acetyldopamine oligomers from Cicadae Periostracum in rats by ultra-high performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry.

Cicadae Periostracum (CP), the cast-off shell of Cryptotympana atrata, is specified in Chinese Pharmacopoeia for relieving fever and eliminating ulcer. N-acetyldopamine oligomers are the major characteristic bioactive components with antioxidant and anti-inflammatory activities that may be responsible for the efficacy of CP. However, the exposed components and metabolites of N-acetyldopamine oligomers of CP (NOCP) in vivo are still unknown. In present study, the metabolic profile of total NOCP and N-acetyldopamine dimer B in rats were systematically investigated by ultra-high liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC-QTOF-MS/MS). In biosamples of NOCP group, 34 prototypes and 15 metabolites were identified or tentatively characterized, including 5 metabolites in plasma, 3 prototype and 9 metabolites in urine, 2 metabolites in bile, 34 prototypes and 8 metabolites in feces, respectively. In dimer B group, the prototype and 8 metabolites were identified, including 2 metabolites in plasma, 4 metabolites in urine, 1 metabolite in bile and 5 metabolites in feces, respectively. Oxidation, and hydrogenation were supposed to be the major phase I reactions, while methylation, sulfation, and glucuronidation were the main phase II reactions of NOCP and dimer B. M10 and M13 might undergo enterohepatic circulation in rats. It is concluded that NOCP and dimer B were mainly absorbed in the form of metabolites, and metabolites are probably the major bioactive forms of NOCP and dimer B. The outcomes of this study provided helpful information for extensively elucidating biological and pharmacological mechanisms of NOCP.