Impact of obesity on sentinel lymph node biopsy outcomes and survival in breast cancer patients: A single-center retrospective study.

BACKGROUND: Sentinel lymph node biopsy (SLNB) is a common choice for axillary surgery in patients with early-stage breast cancer (BC) who have clinically negative lymph nodes. Most research indicates that obesity is a prognostic factor for BC patients, but studies assessing its association with the rate of positive sentinel lymph nodes (SLN) and the prognosis of patients with early BC undergoing SLNB are limited. METHODS: Between 2013 and 2016, 7062 early-stage BC patients from the Shanghai Cancer Center of Fudan University were included. Based on the Chinese Body Mass Index (BMI) classification standards, the patients were divided into three groups as follows: normal weight, overweight, and obese. Propensity score matching analysis was used to balance the baseline characteristics of the participants. Logistic regression analysis was used to determine the association between obesity and positive SLN rate. Cox regression analysis was used to investigate whether obesity was an independent prognostic factor for early-stage BC patients who had undergone SLNB. RESULTS: No significant association was observed between obesity and positive SLN rate in early-stage BC patients who had undergone SLNB. However, multivariate analysis revealed that compared to patients with normal BMI, the overall survival (hazard ratio (HR) 2.240, 95% confidence interval (CI) 1.27-3.95, p = 0.005) and disease-free survival (HR 1.750, 95% CI 1.16-2.62, p = 0.007) were poorer in patients with high BMI. CONCLUSION: Obesity is an independent prognostic factor for early-stage BC patients who undergo SLNB; however, it does not affect the positive SLN rate.

Chemical structure of hydrocarbons significantly affects removal performance and microbial responses in gas biotrickling filters.

The control of emissions of short-chain hydrocarbons with different structures is critical for the petrochemical industry. Herein, three two-carbon-containing (C2) hydrocarbons, ethane, ethylene, and acetylene, were chosen as pollutants to study the effects of chemical structure of hydrocarbons on removal performance and microbial responses in biotrickling filters. Results showed that the removal efficiency (RE) of C2 hydrocarbons followed the sequence of acetylene > ethane > ethylene. When the inlet loading rate was 30 g/(m3·h) and the empty bed residence time was 60 s, the RE of ethane, ethylene, and acetylene was 57 ± 4.0 %, 49 ± 1.0 %, and 84 ± 2.7 %, respectively. The high water solubility resulted in the high removal of C2 hydrocarbons, while a low surface tension enhanced the removal of C2 hydrocarbons. Additionally, the microbial community, enzyme activity, and extracellular properties of microorganisms also contributed to the difference in C2 hydrocarbon removal. These results could be referred for the effective control of light hydrocarbon emissions.

Relationships Among Physical Activity, Daylight Exposure, and Rest-Activity Circadian Rhythm in Patients With Esophageal and Gastric Cancer: An Exploratory Study.

BACKGROUND: Although rest-activity circadian rhythm (RACR) disruption is associated with mortality in patients with cancer, few studies have examined the effect of RACR on patients with esophageal and gastric cancer. OBJECTIVE: The aim of this study was to identify the predictors of RACR. METHODS: This cross-sectional, single-site study included 276 patients with esophageal and gastric cancer recruited from chest-surgery and general-surgery outpatient departments. Actigraphy was used to assess objective physical activity (PA), daylight exposure, and RACR, and 3-day PA was used to indicate the subjective amount of PA. The parameter of objective PA was the up activity mean; the parameter of daylight exposure was >500 lx, and the parameters of RACR were the 24-hour correlation coefficient, in-bed less than out-of-bed dichotomy index, midline estimating statistic of rhythm, and amplitude. The subjective amount of PA was calculated as the sum of mild, moderate, and vigorous PA. RESULTS: The up activity mean predicted 24-hour correlation coefficient. The PA amount and up activity mean predicted in-bed less than out-of-bed dichotomy index. The up activity mean and >500-lx daylight exposure predicted midline estimating statistic of rhythm. Finally, the PA amount and up activity mean predicted the amplitude. CONCLUSIONS: Increased PA and daylight exposure may improve RACR. IMPLICATIONS FOR PRACTICE: Patients with esophageal and gastric cancer should be encouraged to engage in outdoor PA during the daytime as part of their regular lifestyle to maintain a robust circadian rhythm.

Associations of unintended pregnancy with autism spectrum disorders and the modification of folic acid supplements.

There is limited evidence on the associations of unintended pregnancy with autism spectrum disorders (ASD). This study aimed to examine this relationship and the modification of pre-conceptional and prenatal folic acid supplements. Six thousand and five toddlers aged 16 to 30 months from seven cities of six provinces in China were eligible for participation. Information on unintended pregnancy and folic acid supplements was obtained via questionnaires from caregivers of toddlers. The diagnosis of ASD was based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and the Chinese version of the Childhood Autism Rating Scale (CARS). Of the 6005 toddlers in the study (3337 boys and 2668 girls), 71 (1.18%) received the diagnosis of ASD. Generalized linear models with a logit link function showed unintended pregnancy was positively associated with ASD (odds ratios [OR] = 1.69, 95% confidence interval [CI], 1.05-2.79). Stratified estimates indicated that the association remained stable among toddlers of mothers without pre-conceptional and prenatal folic acid supplements (OR = 2.75, 95% CI, 1.04-7.27; n = 1243, 20.70%). Unintended pregnancy was associated with higher odds of ASD in 16-30 months of toddlers, and the association was consistent among toddlers of mothers without prenatal folic acid supplements. Our findings emphasize the need to raise awareness of the risk of unintended pregnancy and the benefits of folic acid supplements among Chinese women.

Nanobodies as negative allosteric modulators for human calcium sensing receptor.

Human calcium sensing receptor (CaSR) senses calcium ion concentrations in vivo and is an important class of drug targets. Mutations in the receptor can lead to disorders of calcium homeostasis, including hypercalcemia and hypocalcemia. Here, 127 CaSR-targeted nanobodies were generated from camels, and four nanobodies with inhibitory function were further identified. Among these nanobodies, NB32 can effectively inhibit the mobilization of intracellular calcium ions (Ca2+i) and suppress the G12/13 and ERK1/2 signaling pathways downstream of CaSR. Moreover, it enhanced the inhibitory effect of the calcilytics as a negative allosteric modulator (NAM). We determined the structure of complex and found NB32 bound to LB2 (Ligand-binding 2) domain of CaSR to prevent the interaction of LB2 domains of two protomers to stabilize the inactive state of CaSR.

Assessing the risk factors associated with sarcopenia in patients with liver cirrhosis: a case-control study.

Sarcopenia is a disease characterized by decreased muscle mass and strength, affecting 20-70% of patients with cirrhosis, and is associated with poor prognosis, complications, and high mortality. At present, the epidemiological investigation of sarcopenia in patients with liver cirrhosis is relatively limited, and because of the differences in population characteristics, regions, diagnostic criteria and diagnostic tools, the prevalence of sarcopenia in various studies varies greatly. The definition of sarcopenia in this study adopted the criteria of the Asian Working Group on Sarcopenia (AWGS 2019), including muscle mass and muscle strength / physical performance. A total of 271 patients with liver cirrhosis were included in this cross-sectional study to explore the influencing factors of sarcopenia in patients with liver cirrhosis. The prevalence of sarcopenia was 27.7%, 27.3% in male and 28.4% in female. The results of binary logistic regression analysis showed that age, physical activity, BMI, mid-upper arm muscle circumference, hepatic encephalopathy, nutritional status, alkaline phosphatase, albumin and total cholesterol were significantly correlated with the occurrence of sarcopenia in patients with liver cirrhosis. After adjusting for the potential influencing factors, it was found that the correlation between age and sarcopenia was weakened (OR = 0.870, 95% CI 0.338-2.239). The current findings show that sarcopenia is common in patients with cirrhosis and is independently associated with age, physical activity, BMI, nutritional status, and albumin, and serum alkaline phosphatase and total cholesterol are associated with the development of sarcopenia. Regular exercise may help maintain the grip strength of patients with cirrhosis and delay the deterioration of liver function.

Specific brain imaging alterations underlying autistic traits in children with attention-deficit/hyperactivity disorder.

BACKGROUND: Autistic traits (ATs) are frequently reported in children with Attention-Deficit/Hyperactivity Disorder (ADHD). This study aimed to examine ATs in children with ADHD from both behavioral and neuroimaging perspectives. METHODS: We used the Autism Spectrum Screening Questionnaire (ASSQ) to assess and define subjects with and without ATs. For behavioral analyses, 67 children with ADHD and ATs (ADHD + ATs), 105 children with ADHD but without ATs (ADHD - ATs), and 44 typically developing healthy controls without ATs (HC - ATs) were recruited. We collected resting-state functional magnetic resonance imaging (rs-fMRI) data and analyzed the mean amplitude of low-frequency fluctuation (mALFF) values (an approach used to depict different spontaneous brain activities) in a sub-sample. The imaging features that were shared between ATs and ADHD symptoms or that were unique to one or the other set of symptoms were illustrated as a way to explore the "brain-behavior" relationship. RESULTS: Compared to ADHD-ATs, the ADHD + ATs group showed more global impairment in all aspects of autistic symptoms and higher hyperactivity/impulsivity (HI). Partial-correlation analysis indicated that HI was significantly positively correlated with all aspects of ATs in ADHD. Imaging analyses indicated that mALFF values in the left middle occipital gyrus (MOG), left parietal lobe (PL)/precuneus, and left middle temporal gyrus (MTG) might be specifically related to ADHD, while those in the right MTG might be more closely associated with ATs. Furthermore, altered mALFF in the right PL/precuneus correlated with both ADHD and ATs, albeit in diverse directions. CONCLUSIONS: The co-occurrence of ATs in children with ADHD manifested as different behavioral characteristics and specific brain functional alterations. Assessing ATs in children with ADHD could help us understand the heterogeneity of ADHD, further explore its pathogenesis, and promote clinical interventions.

Development of a novel 1-octen-3-ol-loaded agar/curdlan hydrogel for inhibiting peach fruit diseases.

Our previous study found that 1-octen-3-ol fumigation treatment could effectively induce the resistance of peach fruit diseases. However, 1-octen-3-ol is a liquid fumigant, which is not conducive to storage and application. Herein, the gel of 1 % agar compound with 1 % curdlan was used as a novel material for covering 1-octen-3-ol. The interaction of agar and curdlan was promoted by adding 1-octen-3-ol, leading to a higher thermostability compared to single-component antibacterial gels. Moreover, 1-octen-3-ol resulted in changes in the internal structure and mechanical properties of gel to form a pore-like structure, which is beneficial to the retention and release of 1-octen-3-ol. Additionally, the 2 % agar gel containing 1-octen-3-ol had the best inhibitory effect on the mycelial growth of Monilinia fructicola and Rhizopus stolonifer in vitro, and the compound hydrogel of 1 % agar and 1 % curdlan with 1-octen-3-ol could most effectively inhibit brown rot and soft rot caused by these two pathogens in vivo. Overall, the data indicated that the novel 1-octen-3-ol-loaded agar/curdlan hydrogels could effectively retain and release 1-octen-3-ol, and induce the resistance of peach fruit diseases.

Dl-3-n-butylphthalide promotes angiogenesis in ischemic stroke mice through upregulating autocrine and paracrine sonic hedgehog.

Dl-3-n-butylphthalide (NBP) is a small-molecule drug used in the treatment of ischemic stroke in China, which is proven to ameliorate the symptoms of ischemic stroke and improve the prognosis of patients. Previous studies have shown that NBP accelerates recovery after stroke by promoting angiogenesis. In this study, we investigated the mechanisms underlying the angiogenesis-promoting effects of NBP in ischemic stroke models in vitro and in vivo. OGD/R model was established in human umbilical vein endothelial cells (HUVECs) and human brain microvascular endothelial cells (HBMECs), while the tMCAO model was established in mice. The cells were pretreated with NBP (10, 50, 100 µM); the mice were administered NBP (4, 8 mg/kg, i.v.) twice after tMCAO. We showed that NBP treatment significantly stimulated angiogenesis by inducing massive production of angiogenic growth factors VEGFA and CD31 in both in vitro and in vivo models of ischemic stroke. NBP also increased the tubule formation rate and migration capability of HUVECs in vitro. By conducting the weighted gene co-expression network analysis, we found that these effects were achieved by upregulating the expression of a hedgehog signaling pathway. We demonstrated that NBP treatment not only changed the levels of regulators of the hedgehog signaling pathway but also activated the transcription factor Gli1. The pro-angiogenesis effect of NBP was abolished when the hedgehog signaling pathway was inhibited by GDC-0449 in HUVECs, by Sonic Hedgehog(Shh) knockdown in HUVECs, or by intracerebroventricular injection of AAV-shRNA(shh)-CMV in tMCAO mice. Furthermore, we found that HUVECs produced a pro-angiogenic response not only to autocrine Shh, but also to paracrine Shh secreted by astrocytes. Together, we demonstrate that NBP promotes angiogenesis via upregulating the hedgehog signaling pathway. Our results provide an experimental basis for the clinical use of NBP.

Characteristics of Electrocardiogram Findings in Fulminant Myocarditis.

Fulminant myocarditis (FM) is an acute and severe form of myocarditis with rapid progression and poor clinical outcomes in the absence of acute or chronic coronary artery disease. Electrocardiogram (ECG) abnormalities can provide preliminary clues for diagnosis; however, there is a lack of systemic descriptions on ECG changes in FM populations. Thus, a retrospective analysis of 150 consecutive FM patients and 300 healthy controls was performed to determine the characteristic ECG findings in FM. All patients included had markedly abnormal ECG findings. Specifically, 83 (55.33%) patients had significantly lower voltage with remarkably decreased QRS amplitudes in all leads compared with healthy controls (p < 0.01), and 77 (51.33%) patients had a variety of arrhythmias with lethality ventricular tachycardia/ventricular fibrillation in 21 (14.00%) patients and third-degree atrioventricular block in 21 (14.00%) patients, whereas sinus tachycardia was only found in 43 (28.67%) patients with the median heart rate (HR; 88.00 bpm, IQR: 76.00-113.50) higher than that of controls (73.00 bpm, IQR: 68.00-80.00) (p = 0.000). Conduction and repolarization abnormalities were common in patients. A longer QTc interval (452.00 ms, IQR: 419.00-489.50) and QRS duration (94.00 ms, IQR: 84.00-119.00) were observed in patients compared to controls (QTc interval = 399.00 ms, IQR: 386.00-414.00; QRS duration = 90.00 ms, IQR: 86.00-98.00) (p < 0.05). Additionally, HR > 86.50 bpm, QTc > 431.50 ms, and RV5 + SV1 < 1.715 mV can be used to predict FM. Thus, marked and severe ECG abnormalities provide preliminary clues for the diagnosis of FM.

Solving the regulation puzzle of periderm development using advances in fruit skin.

Periderm protects enlarged organs of most dicots and gymnosperms as a barrier to water loss and disease invasion during their secondary growth. Its development undergoes a complex process with genetically controlled and environmental stress-induced characters. Different development of periderm makes the full and partial russet of fruit skin, which diverges in inheritance with qualitative and quantitative characters, respectively, in pear pome. In addition to its specific genetics, fruit periderm has similar development and structure as that of stem and other organs, making it an appropriate material for periderm research. Recently, progress in histochemical as well as transcriptome and proteome analyses, and quantitative trait locus (QTL) mapping have revealed the regulatory molecular mechanism in the periderm based on the identification of switch genes. In this review, we concentrate on the periderm development, propose the conservation of periderm regulation between fruit and other plant organs based on their morphological and molecular characteristics, and summarize a regulatory network with the elicitors and repressors for the tissue development. Spontaneous programmed-cell death (PCD) or environmental stress produces the original signal that triggers the development of periderm. Spatio-temporal specific PCD produced by PyPPCD1 gene and its homologs can play a key role in the coordinated regulation of cell death related tissue development.

Co-expression of DDR2 and IFITM1 promotes breast cancer cell proliferation, migration and invasion and inhibits apoptosis.

PURPOSE: To investigate the roles of DDR2 and IFITM1 in breast cancer (BC). METHODS: The expression of DDR2 and IFITM1 in BC tissues and cell lines was measured. DDR2 and/or IFITM1 were knocked down in BT20 and MDA-MB-231 cells, after which the viability, mobility and apoptosis of the cells were tested. Xenograft mouse models were established through subcutaneous tumor transplantation. RESULTS: DDR2 and IFITM1 were highly expressed in invasive BC tissues and cell lines. Overexpression of DDR2 and/or IFITM1 was associated with poorer clinical outcomes and patient survival. Knockdown of DDR2 or IFITM1 suppressed the viability and invasiveness of BT20 and MDA-MB-231 cells and restrained the growth of xenograft tumors in nude mice. Simultaneous knockdown of IFITM1 and DDR2 surpassed knockdown of IFITM1 alone in suppressing BC development. CONCLUSIONS: DDR2 and IFITM1 are co-expressed to facilitate the malignant behaviors of BC cells and promote the development of tumors.

Indirect spectrophotometric determination of aqueous ferrate(VI) based on its reaction with iodide in acidic media.

Ferrate(VI) (Fe(VI)) is utilized as an efficient and environmentally friendly water treatment agent that can be widely used for degradation of (in)organic pollutants in practical applications. However, only a few spectrophotometric methods for Fe(VI) determination were reported. In this study, a novel method for determining trace levels of aqueous Fe(VI) was developed based on the fact that Fe(VI) reacts with iodide at acidic pH to form iodine, which subsequently is treated with starch to yield the blue starch-iodine complex measured spectrophotometrically at 590 nm. The key measurement parameters, including acidic medium, starch dosages, temperature, time, and addition order were optimized to improve the sensitivity of detection. The increase in absorbance at 590 nm was linear with respect to Fe(VI) added (0.022-50 µM). Its sensitivity was determined as (4.61 ± 0.05) × 104 M-1 cm-1, which was higher than that of existing spectrophotometric methods. The principle for Fe(VI) determination was studied by investigating stoichiometry, kinetics, and mechanism of Fe(VI) reaction with iodide. The molar stoichiometry of Fe(VI) with I3- species was determined to be 1:2. The reaction of Fe(VI) with iodide followed a second-order rate law with first order in each reactant and displayed apparent anti-Arrhenius kinetics, then its reaction pathway was proposed as well. Furthermore, the established method was successfully applied to measure Fe(VI) in various environmental water samples. The results show that the proposed approach is simple, convenient, highly reproducible and extremely sensitive, and is also expected to be of use for kinetic studies of Fe(VI) reaction with (in)organic compounds under acidic conditions.

Psychometric properties of the Chinese version of the children's empathy quotient and systemizing quotient: 4-12 years.

We aimed to validate the Children's Empathy Quotient (EQ-C) and Systemizing Quotient (SQ-C) in Mainland China, which can reflect the profiles of empathizing and systemizing, and describing specific characteristics of autism spectrum disorder (ASD) and gender-typical behaviors in general population. A total of 800 typically developing (TD) children, aged 4-12 years was recruited initially with whose parents/guardians complete the measurements, and 782 TD children who met inclusion criteria were finally included. A 23-item three-factor EQ-C and a 22-item four-factor SQ-C was developed with good internal consistency (Omega total values of 0.87 and 0.86) and test-retest reliability (Pearson correlation coefficients of 0.82 and 0.69). In TD children, girls scored significantly higher on EQ-C (31.4 ± 7.8 vs. 28.2 ± 7.7) but there were no gender differences in SQ-C scores. TD children showed different cognitive styles (empathizing-dominant for girls with 42.6% identified as Type E; systemizing-dominant for boys with 40.7% identified as Type S). A further sample of 222 children with ASD indicated that they scored lower on EQ/SQ-C compared to TD children (13.2 ± 5.1 vs. 29.7 ± 7.9, 12.4 ± 5.8 vs. 23.5 ± 8.3) and were generally systemizing-dominant (Type S: 50.8% for boys and 64.0% for girls). Autistic children scored higher on the SQ-C in those without intellectual disability and with higher paternal education level and family income (14.2 ± 6.1 vs. 10.9 ± 5.0, 13.3 ± 6.2 vs. 11.5 ± 5.1, 13.7 ± 5.6 vs. 11.9 ± 5.8), while there were no differences in the EQ-C. This study indicated good reliability and validity of the Chinese version of EQ/SQ-C, which can be used in Chinese children with and without ASD. LAY SUMMARY: We developed the Chinese version of the Children's Empathy Quotient (EQ-C) and Systemizing Quotient (SQ-C) in 782 typically developing (TD) children aged 4-12 years in Mainland China, yielding a 23-item, 3-factor EQ-C and a 22-item, 4-factor SQ-C with good psychometric properties. In TD children, we found gender difference only in scores of EQ-C. Further analyses of 222 autistic children indicated that differences were found in scores of SQ-C when considering their gender, intelligence and socio-economic status.

Empathy, Theory of Mind, and Prosocial Behaviors in Autistic Children.

Background: Previous research has suggested that children with autism spectrum disorder (ASD) display fewer prosocial behaviors, and the role of empathy or Theory of Mind (ToM) in prosocial behaviors of autistic children remains unclear. Methods: Data were obtained from an ongoing longitudinal study in Guangzhou, China. A total of 96 autistic children and 167 typically developing (TD) children were enrolled. Prosocial behaviors were assessed using a subscale of the Strength and Difficulties Questionnaire and Dictator Game (DG) paradigm with stickers as incentives. Empathic traits and ToM ability were measured using the children's Empathy Quotient and the Chinese version of ToM toolkit. Generalized linear models were used to assess the differences of prosocial behaviors and empathic traits, ToM ability between the two groups and the associations between empathic traits, ToM ability and prosocial behaviors in autistic children. Results: Compared with TD children, autistic children exhibited worse ToM ability and performed less pro-socially in the DG paradigm, while there were no differences regarding empathic traits. In autistic children, empathic traits especially affective empathy, were positively associated with parent-reported prosocial behaviors [ß = 0.17, 95% confidence interval (CI): 0.07-0.27; ß = 0.47, 95%CI: 0.33-0.60]. ToM ability was associated with DG paradigm (ß = 1.03, 95%CI: 0.16-1.89). Conclusion: Autistic children showed less pro-sociality and ToM ability than TD children. In autistic children, empathic trait was associated with parent-reported prosocial behaviors while their ToM ability was associated with prosocial behaviors in experimental condition. Our findings indicated that better ToM ability and empathic trait might promote prosocial behaviors in autistic children.

Expression, Purification, and Preliminary Protection Study of Dehydrin PicW1 From the Biomass of Picea wilsonii.

Dehydrins (DHNs) belong to group II of late embryogenesis-abundant (LEA) proteins, which are up-regulated in most plants during cold, drought, heat, or salinity stress. Despite the importance of dehydrins for the plants to resist abiotic stresses, it is necessary to obtain plant-derived dehydrins from different biomass. Generally, dehydrin PicW1 from Picea wilsonii is involved in Kn-type dehydrin with five K-segments, which has a variety of biological activities. In this work, Picea wilsonii dehydrin PicW1 was expressed in Escherichia coli and purified by chitin-affinity chromatography and size-exclusion chromatography, which showed as a single band by SDS-PAGE. A cold-sensitive enzyme of lactate dehydrogenase (LDH) is used to explore the protective activities of other proteins. Temperature stress assays showed that PicW1 had an effective protective effect on LDH activity, which was better than that of bovine serum albumin (BSA). This study provides insights into the purification and protective activity of K5 DHNs for the advancement of dehydrin structure and function from biomass.

Study of nuclear modification factors of deuteron and anti-deuteron in Pb-Pb collisions at [Formula: see text].

The nuclear modification factors ([Formula: see text]) of d and [Formula: see text] have been studied using the parton and hadron cascade model plus the dynamically constrained phase space coalescence model in peripheral (40-60%) and central (0-5%) Pb-Pb collisions at [Formula: see text] with [Formula: see text]. It is found that the [Formula: see text] of [Formula: see text] is similar to that of hadrons ([Formula: see text]) and the [Formula: see text] of antiparticles is the same as that of particles. The suppression effect of d is more significant than that of baryons and mesons in the high-[Formula: see text] region. The suppression of [Formula: see text] at high-[Formula: see text] strongly depends on event centrality and mass of the particles, i.e., the central collision is more suppressed than the peripheral collision. Besides, the yield ratios and double ratios for different particle species, and the coalescence parameter [Formula: see text] for ([Formula: see text]) in pp and Pb-Pb collisions are discussed, respectively. It is observed that the yield ratios and double ratios of d to p and p to [Formula: see text] are similar to those of their anti-particles in three different collision systems, suggesting that the suppressions of matter ([Formula: see text]) and the corresponding antimatter ([Formula: see text]) are around the same level.

Expression, purification and structural characterization of resveratrol synthase from Polygonum cuspidatum.

Polygonum cuspidatum, an important medicinal plant in China, is a rich source of resveratrol compounds, and its synthesis related resveratrol synthase (RS) gene is highly expressed in stems. The sequence of the resveratrol synthase was amplified with specific primers. Sequence comparison showed that it was highly homologous to the STSs. The RS gene of Polygonum cuspidatum encodes 389 amino acids and has a theoretical molecular weight of 42.4 kDa, which is called PcRS1. To reveal the molecular basis of the synthesized resveratrol activity of PcRS1, we expressed the recombinant protein of full-length PcRS1 in Escherichia coli, and soluble protein products were produced. The collected products were purified by Ni-NTA chelation chromatography and appeared as a single band on SDS-PAGE. In order to obtain higher purity PcRS1, SEC was used to purify the protein and sharp single peak, and DLS detected that the aggregation state of protein molecules was homogeneous and stable. In order to verify the enzyme activity of the high-purity PcRS1, the reaction product was detected at 303 nm. By predicting the structural information of monomer PcRS1 and PcRS1 ligand complexes, we analyzed the ligand binding pocket and protein surface electrostatic potential of the complex, and compared it with the highly homologous STSs protein structures of the iso-ligand. New structural features of protein evolution are proposed. PcRS1 obtained a more complete configuration and the optimal orientation of the active site residues, thus improving its catalytic capacity in resveratrol synthesis.

Structural insights into the activation of human calcium-sensing receptor.

Human calcium-sensing receptor (CaSR) is a G-protein-coupled receptor that maintains Ca2+ homeostasis in serum. Here, we present the cryo-electron microscopy structures of the CaSR in the inactive and agonist+PAM bound states. Complemented with previously reported structures of CaSR, we show that in addition to the full inactive and active states, there are multiple intermediate states during the activation of CaSR. We used a negative allosteric nanobody to stabilize the CaSR in the fully inactive state and found a new binding site for Ca2+ ion that acts as a composite agonist with L-amino acid to stabilize the closure of active Venus flytraps. Our data show that agonist binding leads to compaction of the dimer, proximity of the cysteine-rich domains, large-scale transitions of seven-transmembrane domains, and inter- and intrasubunit conformational changes of seven-transmembrane domains to accommodate downstream transducers. Our results reveal the structural basis for activation mechanisms of CaSR and clarify the mode of action of Ca2+ ions and L-amino acid leading to the activation of the receptor.