[Expression and prognostic significance of KAP1 gene in malignant pleural mesothelioma]

Objective: To explore the expression of KAP1 (KRAB-associated protein 1, KAP1) in Malignant pleural mesothelioma (MPM) based on the cancer genome atlas (TCGA) and clinical trials. And elucidate the correlation between the expression of KAP1 and the clinical pathological parameters of patients with MPM and its prognosis. Methods: In April 2022, Based on the second generation KAP1mRNA sequencing data and clinicopathological data of MPM patients downloaded from TCGA database, the correlation between KAP1mRNA expression and clinical parameters was analyzed, and the correlation between KAP1 protein expression and clinicopathological parameters and its prognostic value were analyzed based on Chuxiong data set cohort clinical samples. The expression of KAP1 mRNA in MPM samples and matched normal tumor adjacent tissues was detected by qRT-PCR, and the expression of KAP1 protein in MPM and normal pleural tissues was detected by immunohistochemistry and Westernblotting. To construct a Kaplan-Meier model to explore the effect of KAP1 expression on the prognosis of MPM patients, and to analyze the prognostic factors of MPM patients by Cox regression. Results: qRT-PCR and Western blotting detection showed that the expression levels of KAP1 gene in four different MPM cells (NCI-H28, NCI-H2052, NCI-H2452, and MTSO-211H) were significantly higher than those in normal pleural mesothelial cells Met-5A. qRT-PCR, Western blotting and IHC results demonstrated that the mRNA and protein expression levels of KAP1 in MPM tissues was significantly higher than that in matching normal mesothelial tissues, and the expression level of KAP1 protein was correlated with TP 53 protein expression levels and serum CEA levels (P<0.05) . The mRNA expression level was significantly correlated with the prognosis, The overall survival time of mesothelioma patients with high KAP1mRNA expression was significantly shorter (HR=3.7, Logrank P<0.001) . Tumor type, age and the mRNA expression were related to the prognosis of MPM patients (P<0.05) . Multivariate analysis showed that tumor type and KAP1 mRNA expression level were independent prognostic factors of MPM patients (P<0.05) . Conclusion: In this study, TCGA database and Chuxiong cohort experiment samples were used to collect the relevant information of KAP1 expression in malignant melanoma tissues. It was confirmed that KAP1 is highly expressed in MPM tissues. The mRNA expression level and pathological type are correlated with the prognosis of patients.

Molecular evolution and characterization of type III polyketide synthase gene family in Aquilaria sinensis

2-(2-Phenylethyl) chromone (PEC) and its derivatives are markers of agarwood formation and are also related to agarwood quality. However, the biosynthetic and regulatory mechanisms of PECs still remain mysterious. Several studies suggested that type III polyketide synthases (PKSs) contribute to PEC biosynthesis in Aquilaria sinensis. Furthermore, systematic studies on the evolution of PKSs in A. sinensis have rarely been reported. Herein, we comprehensively analyzed PKS genes from 12 plant genomes and characterized the AsPKSs in detail. A unique branch contained only AsPKS members was identified through evolutionary analysis, including AsPKS01 that was previously indicated to participate in PEC biosynthesis. AsPKS07 and AsPKS08, two tandem-duplicated genes of AsPKS01 and lacking orthologous genes in evolutionary models, were selected for their transient expression in the leaves of Nicotiana benthamiana. Subsequently, PECs were detected in the extracts of N. benthamiana leaves, suggesting that AsPKS07 and AsPKS08 promote PEC biosynthesis. The interaction between the promoters of AsPKS07, AsPKS08 and five basic leucine zippers (bZIPs) from the S subfamily indicated that their transcripts could be regulated by these transcription factors (TFs) and might further contribute to PECs biosynthesis in A. sinensis. Our findings provide valuable insights into the molecular evolution of the PKS gene family in A. sinensis and serve as a foundation for advancing PEC production through the bioengineering of gene clusters. Ultimately, this contribution is expected to shed light on the mechanism underlying agarwood formation.

Aquilaria sinensis: An Upstart Resource for Cucurbitacin Production Offers Insights into the Origin of Plant Bitter (Bi) Gene Clusters

Cucurbitacins, oxygenated tetracyclic triterpenoids that are found mainly in the Cucurbitaceae family, play essential roles as defensive compounds, serving as allomones against herbivores and pathogens and as signals for insect-parasite recognition. These compounds also exhibit various pharmacological effects. The biosynthesis of cucurbitacins is largely regulated by the bitter (Bi) gene, encoding an oxidosqualene cyclase, which catalyzes the conversion of 2,3-oxidosqualene into cucurbitadienol, a common precursor for cucurbitacin synthesis. Previous studies focused on uncovering the Bi gene clusters in Cucurbitaceae, but their presence in other cucurbitacin-producing plants remained unexplored. Here, the evolutionary history of Bi genes and their clusters were investigated in twenty-one plant genomes spanning three families based on chemotaxonomy. Nineteen Bi genes were identified in fourteen Cucurbitaceae, four Begoniaceae, and one Aquilaria species. Phylogenetic analysis suggested that the genome of Aquilaria sinensis contained the earliest Bi gene clusters in this dataset. Moreover, the genomic analysis revealed a conserved microsynteny of pivotal genes for cucurbitacin biosynthesis in Cucurbitaceae, while interspersed Bi gene clusters were observed in Begoniaceae, indicating rearrangements during plant Bi gene cluster formation. The bitter gene in A. sinensis was found to promote cucurbitadienol biosynthesis in the leaves of Nicotiana benthamiana. This comprehensive exploration of plant Bi genes and their clusters provides valuable insights into the genetic and evolutionary underpinnings of cucurbitacin biosynthesis. These findings offer prospects for a deeper understanding of cucurbitacin production and potential genetic resources for their enhancement in various plants.

Comprehensive Analysis of NAC Transcription Factors Reveals Their Evolution in Malvales and Functional Characterization of AsNAC019 and AsNAC098 in Aquilaria sinensis

NAC is a class of plant-specific transcription factors that are widely involved in the growth, development and (a)biotic stress response of plants. However, their molecular evolution has not been extensively studied in Malvales, especially in Aquilaria sinensis, a commercial and horticultural crop that produces an aromatic resin named agarwood. In this study, 1502 members of the NAC gene family were identified from the genomes of nine species from Malvales and three model plants. The macroevolutionary analysis revealed that whole genome duplication (WGD) and dispersed duplication (DSD) have shaped the current architectural structure of NAC gene families in Malvales plants. Then, 111 NAC genes were systemically characterized in A. sinensis. The phylogenetic analysis suggests that NAC genes in A. sinensis can be classified into 16 known clusters and four new subfamilies, with each subfamily presenting similar gene structures and conserved motifs. RNA-seq analysis showed that AsNACs presents a broad transcriptional response to the agarwood inducer. The expression patterns of 15 AsNACs in A. sinensis after injury treatment indicated that AsNAC019 and AsNAC098 were positively correlated with the expression patterns of four polyketide synthase (PKS) genes. Additionally, AsNAC019 and AsNAC098 were also found to bind with the AsPKS07 promoter and activate its transcription. This comprehensive analysis provides valuable insights into the molecular evolution of the NAC gene family in Malvales plants and highlights the potential mechanisms of AsNACs for regulating secondary metabolite biosynthesis in A. sinensis, especially for the biosynthesis of 2-(2-phenyl) chromones in agarwood.

Supramolecular assembly of dendronized spiropyrans in aqueous solutions into nanospheres with photo- and thermo-responsive chiralities

Tailoring the amphiphilicity of a molecule through external stimuli can alter the balance between self-association and repulsion, resulting in different propensities for its assembly. Here we report on the supramolecular assembly of a series of dendronized spiropyrans (DSPs) in water. These DSPs carry 3-fold dendritic oligoethylene glycols (OEGs) with either methoxyl or ethoxyl terminals for different hydrophilicities, and contain an Ala-Gly dipeptide to provide the chirality. These dendronized amphiphiles form supramolecular nanospheres in aqueous solutions with remarkable induced chirality to a level of 1.0 × 106 deg cm2 dmol-1. They can be tuned reversibly through photoisomerization of the spiropyran moieties from the hydrophobic SP form into the hydrophilic MC form, and can even become chirally silent through thermally mediated collapse of the dendritic OEGs. Photoisomerization of the spiropyran moieties in these DSPs is accompanied by simultaneous changes of UV absorption, fluorescence emission, supramolecular chirality and aqueous solution colors. These supramolecular nanospheres exhibit characteristic thermoresponsive behavior due to thermal collapse of the dendritic OEGs with their cloud point temperatures (Tcps) being dependent on the overall hydrophilicity of the molecules and also the aggregate morphologies resulting from how dendritic OEGs are wrapped around the aggregates. Both photo-irradiation-mediated isomerization of the spiropyran moieties and thermally mediated dehydration and collapse of the dendritic OEGs influence the amphiphilicity of these DSPs and their solvation by water, leading to varied driving forces for their assembly. NMR, circular dichroism (CD) and fluorescence spectroscopy techniques, as well as DLS and AFM techniques are combined to follow the supramolecular assembly and illustrate the aggregation mechanism. All experimental results demonstrate that the reversible chirality of the aggregates originates from the balance between dendritic OEGs and spiropyran moieties against water solvation.

Systematic evolution of bZIP transcription factors in Malvales and functional exploration of AsbZIP14 and AsbZIP41 in Aquilaria sinensis

Introduction

Agarwood, the dark-brown resin produced by Aquilaria trees, has been widely used as incense, spice, perfume or traditional medicine and 2-(2-phenethyl) chromones (PECs) are the key markers responsible for agarwood formation. But the biosynthesis and regulatory mechanism of PECs were still not illuminated. The transcription factor of basic leucine zipper (bZIP) presented the pivotal regulatory roles in various secondary metabolites biosynthesis in plants, which might also contribute to regulate PECs biosynthesis. However, molecular evolution and function of bZIP are rarely reported in Malvales plants, especially in Aquilaria trees.

Methods and results

Here, 1,150 bZIPs were comprehensively identified from twelve Malvales and model species genomes and the evolutionary process were subsequently analyzed. Duplication types and collinearity indicated that bZIP is an ancient or conserved TF family and recent whole genome duplication drove its evolution. Interesting is that fewer bZIPs in A. sinensis than that species also experienced two genome duplication events in Malvales. 62 AsbZIPs were divided into 13 subfamilies and gene structures, conservative domains, motifs, cis-elements, and nearby genes of AsbZIPs were further characterized. Seven AsbZIPs in subfamily D were significantly regulated by ethylene and agarwood inducer. As the typical representation of subfamily D, AsbZIP14 and AsbZIP41 were localized in nuclear and potentially regulated PECs biosynthesis by activating or suppressing type III polyketide synthases (PKSs) genes expression via interaction with the AsPKS promoters.

Discussion

Our results provide a basis for molecular evolution of bZIP gene family in Malvales and facilitate the understanding the potential functions of AsbZIP in regulating 2-(2-phenethyl) chromone biosynthesis and agarwood formation.

[Analysis of clinicopathological features of 68 cases of malignant pleural mesothelioma]

Objective: To analyze the clinicopathological characteristics of diffuse malignant pleural mesothelioma (MPM), and explore the diagnostic methods in order to improve the early diagnosis rate. Methods: In January 2019 to January 2022, the clinical features, auxiliary examination and immunohistochemical results of 68 cases of MPM were analyzed retrospectively. The pathogenic features, histopathological morphology and the expression of related antibodies including Calretinin (CR), D2-40 and WT-1 were summarized. Results: Among the 68 patients, 40 male (58.82%), 28 female (41.18%), male to female ratio was 1.43%, median age was 58 years old; 50% of patients in Dayao County, epithelial mesothelioma 59 cases (86.76%), occurred in right chest in 39 cases (57.35%), left chest in 25 cases (36.76%), and 4 cases in both sides (5.89%). The most common initial clinical manifestations were pleural effusion (95.59%), chest pain (36.75%), chest tightness and shortness of breath (30.88%). The main imaging findings were pleural effusion in 49 cases (98.00%) and pleural thickening in 46 cases (92.00%). MPM tumor cells often expressed Calretinin, CK5/6, WT1 and D2-40, while TTF-1, NapsinA and CEA, the main markers differentiated from lung adenocarcinoma were negative. Serum CYFRA21-1 and CEA have high value in differential diagnosis of benign and malignant pleural effusions. Conclusion: Diffuse MPM has diverse histological and cytological morphology, which needs to be differentiated from a variety of diseases. Correct diagnosis of diffuse MPM through immunohistochemistry requires the combined application of a group of Mesothelium related antibodies.

Systematic investigation of the R2R3-MYB gene family in Aquilaria sinensis reveals a transcriptional repressor AsMYB054 involved in 2-(2-phenylethyl)chromone biosynthesis

Trees in the genus Aquilaria produce agarwood, a valuable resin used in medicine, perfumes, and incense. 2-(2-Phenethyl)chromones (PECs) are characteristic components of agarwood; however, molecular mechanisms underlying PEC biosynthesis and regulation remain largely unknown. The R2R3-MYB transcription factors play important regulatory roles in the biosynthesis of various secondary metabolites. In this study, 101 R2R3-MYB genes in Aquilaria sinensis were systematically identified and analyzed at the genome-wide level. Transcriptomic analysis revealed that 19 R2R3-MYB genes were significantly regulated by an agarwood inducer, and showed significant correlations with PEC accumulation. Expression and evolutionary analyses revealed that AsMYB054, a subgroup 4 R2R3-MYB, was negatively correlated with PEC accumulation. AsMYB054 was located in the nucleus and functioned as a transcriptional repressor. Moreover, AsMYB054 could bind to the promoters of the PEC biosynthesis related genes AsPKS02 and AsPKS09, and inhibit their transcriptional activity. These findings suggested that AsMYB054 functions as a negative regulator of PEC biosynthesis via the inhibition of AsPKS02 and AsPKS09 in A. sinensis. Our results provide a comprehensive understanding of the R2R3-MYB subfamily in A. sinensis and lay a foundation for further functional analyses of R2R3-MYB genes in PEC biosynthesis.

[Expression of CD24 gene in human malignant pleural mesothelioma and its relationship with prognosis]

Objective: To investigate the expression of CD24 gene in human malignant pleural mesothelioma (MPM) cells and tissues, and evaluate its relationship with clinicopathological characteristics and clinical prognosis of MPM patients. Methods: In February 2021, UALCAN database was used to analyze the correlation between CD24 gene expression and clinicopathological characteristics in 87 cases of MPM patients. The TIMER 2.0 platform was used to explore the relationship between the expression of CD24 in MPM and tumor immune infiltrating cells. cBioportal online tool was used to analyze the correlation between CD24 and MPM tumor marker gene expression. RT-qPCR was used to analyze the expressions of CD24 gene in human normal pleural mesothelial cell lines LP9 and MPM cell lines NCI-H28 (epithelial type), NCI-H2052 (sarcoma type), and NCI-H2452 (biphasic mixed type). RT-qPCR was performed to detect the expressions of CD24 gene in 18 cases of MPM tissues and matched normal pleural tissues. The expression difference of CD24 protein in normal mesothelial tissue and MPM tissue was analyzed by immunohistochemistry. A Kaplan-Meier model was constructed to explore the influence of CD24 gene expression on the prognosis of MPM patients, and Cox regression analysis of prognostic factors in MPM patients was performed. Results: The CD24 gene expression without TP53 mutation MPM patients was significantly higher than that of patients in TP53 mutation (P<0.05). The expression of CD24 gene in MPM was positively correlated with B cells (r(s)=0.37, P<0.001). The expression of CD24 gene had a positive correlation with the expressions of thrombospondin 2 (THBS2) (r(s)=0.26, P<0.05), and had a negative correlation with the expression of epidermal growth factor containing fibulin like extracellular matrix protein 1 (EFEMP1), mesothelin (MSLN) and calbindin 2 (CALB2) (r(s)=-0.31, -0.52, -0.43, P<0.05). RT-qPCR showed that the expression level of CD24 gene in MPM cells (NCI-H28, NCI-H2052 and NCI-H2452) was significantly higher than that in normal pleural mesothelial LP9 cells. The expression level of CD24 gene in MPM tissues was significantly higher than that in matched normal pleural tissues (P<0.05). Immunohistochemistry showed that the expressions of CD24 protein in epithelial and sarcoma MPM tissues were higher than those of matched normal pleural tissues. Compared with low expression of CD24 gene, MPM patients with high expression of CD24 gene had lower overall survival (HR=2.100, 95%CI: 1.336-3.424, P<0.05) and disease-free survival (HR=1.800, 95%CI: 1.026-2.625, P<0.05). Cox multivariate analysis showed that compared with the biphasic mixed type, the epithelial type was a protective factor for the prognosis of MPM patients (HR=0.321, 95%CI: 0.172-0.623, P<0.001). Compared with low expression of CD24 gene, high expression of CD24 gene was an independent risk factor for the prognosis of MPM patients (HR=2.412, 95%CI: 1.291-4.492, P=0.006) . Conclusion: CD24 gene and protein are highly expressed in MPM tissues, and the high expression of CD24 gene suggests poor prognosis in MPM patients.

Seven new 2-(2-phenethyl)chromone derivatives from agarwood of Aquilaria walla

Two rare flavonoid-2-(2-phenylethyl)chromones and five new dimeric 2-(2-phenylethyl)chromones were isolated from ethanol extract of agarwood of Aquilaria walla by LC-MS-guided fractionation procedure. Their structures were established based on extensive spectroscopic methods including HRESIMS, 1D and 2D NMR, as well as by comparison with the literature. Compound 1 showed cytotoxic activity against five human cancer cell lines with IC₅₀ values ranging from 13.40 to 28.96 μM with cisplatin as the positive control.

New Isocoumarins from the Marine Fungus Phaeosphaeriopsis sp. WP-26

Five new isocoumarins, phaeosphaerins A–E (1–5), were isolated from the fermentation broth of the marine fungus Phaeosphaeriopsis sp. WP-26, along with one known isocoumarin, 6,8-dihydroxy-7-methoxy-3-methylisocoumarin (6), and two known pimarane-type diterpenes, diaportheins A (7) and B (8). Their structures were elucidated via NMR experiments, X-ray diffraction analysis, and comparison of the experimental and computed ECD curves. Compounds 1–7 displayed weak neuroprotective effects against H2O2-induced damage in SH-SY5Y cells. Moreover, compound 8 showed cytotoxicity against BEL-7402, SGC-7901, K562, A549, and HL-60 cell lines.

Integrated analysis of Dendrobium nobile extract Dendrobin A against pancreatic ductal adenocarcinoma based on network pharmacology, bioinformatics, and validation experiments

Background: Dendrobium nobile (D. nobile), a traditional Chinese medicine, has received attention as an anti-tumor drug, but its mechanism is still unclear. In this study, we applied network pharmacology, bioinformatics, and in vitro experiments to explore the effect and mechanism of Dendrobin A, the active ingredient of D. nobile, against pancreatic ductal adenocarcinoma (PDAC). Methods: The databases of SwissTargetPrediction and PharmMapper were used to obtain the potential targets of Dendrobin A, and the differentially expressed genes (DEGs) between PDAC and normal pancreatic tissues were obtained from The Cancer Genome Atlas and Genotype-Tissue Expression databases. The protein-protein interaction (PPI) network for Dendrobin A anti-PDAC targets was constructed based on the STRING database. Molecular docking was used to assess Dendrobin A anti-PDAC targets. PLAU, one of the key targets of Dendrobin A anti-PDAC, was immunohistochemically stained in clinical tissue arrays. Finally, in vitro experiments were used to validate the effects of Dendrobin A on PLAU expression and the proliferation, apoptosis, cell cycle, migration, and invasion of PDAC cells. Results: A total of 90 genes for Dendrobin A anti-PDAC were screened, and a PPI network for Dendrobin A anti-PDAC targets was constructed. Notably, a scale-free module with 19 genes in the PPI indicated that the PPI is highly credible. Among these 19 genes, PLAU was positively correlated with the cachexia status while negatively correlated with the overall survival of PDAC patients. Through molecular docking, Dendrobin A was found to bind to PLAU, and the Dendrobin A treatment led to an attenuated PLAU expression in PDAC cells. Based on clinical tissue arrays, PLAU protein was highly expressed in PDAC cells compared to normal controls, and PLAU protein levels were associated with the differentiation and lymph node metastatic status of PDAC. In vitro experiments further showed that Dendrobin A treatment significantly inhibited the proliferation, migration, and invasion, inducing apoptosis and arresting the cell cycle of PDAC cells at the G2/M phase. Conclusion: Dendrobin A, a representative active ingredient of D. nobile, can effectively fight against PDAC by targeting PLAU. Our results provide the foundation for future PDAC treatment based on D. nobile.

p-Quinone Methide-Mediated Nonenzymatic Formation of Chalcane-Containing Dimers in Dragon's Blood

Chalcane-containing dimers are major compounds identified from dragon's blood, the red resin that accumulates in Dracaena trees after injury. The key step for the formation of these dimers was a p-quinone methide (p-QM, 3) mediated nonenzymatic Michael addition. Compound 3 is derived from the spontaneous dehydration of chalcane alcohol-M274 (2). Two dihydroflavonol-4-reductases, discovered in D. cambodiana, reduce dihydrochalcone-M272 (7) to 2. Moreover, the application potential of p-QMs was demonstrated using a 3-like p-QM to synthesize diverse dimeric derivatives.

Case report: Complex paraneoplastic syndromes in thymoma with nephrotic syndrome, cutaneous amyloidosis, myasthenia gravis, and Morvan’s syndrome

Background

Apart from myasthenia gravis (MG), thymoma is associated with a wide spectrum of autoimmune paraneoplastic syndromes (PNSs). Here, we report on a rare case presenting with four different PNSs, namely, MG, membranous nephropathy, cutaneous amyloidosis, and Morvan’s syndrome associated with thymoma.

Case presentation

A middle-aged man was frequently hospitalized because of nephrotic syndrome (stage I membranous nephropathy), cutaneous amyloidosis, and MG with acetylcholine receptor (AChR) antibody and titin antibody positivity. Chest CT showed a thymic mass in the left anterior mediastinum, and he received intravenous immunoglobulin (IVIG), methylprednisolone pulse therapy, thoracoscopic thymoma resection, and radiotherapy. Postoperative pathological examination revealed a type B2 thymoma. During the perioperative stage, his electrocardiogram (ECG) showed myocardial infarction-like ECG changes; however, his levels of cardiac enzymes and troponin were normal, and he had no symptoms of precardiac discomfort. Six months after thymectomy, his nephrotic syndrome and MG symptoms were relieved; however, he presented with typical manifestations of Morvan’s syndrome, including neuromyotonia, severe insomnia, abnormal ECG activity, and antibodies against leucine-rich glioma-inactivated 1 (LGI1) and γ-amino-butyric acid-B receptor (GABABR). His symptoms did not improve after repeated IVIG and steroid therapies. Finally, he received low-dose rituximab, and his symptoms gradually resolved.

Conclusion

This case serves to remind us that apart from MG, thymoma is also associated with other autoimmune PNSs such as membranous nephropathy, cutaneous amyloidosis, and Morvan’s syndrome. Autoimmune PNSs can present concurrently with or after surgical or medical therapy for thymoma. For Morvan’s syndrome post-thymectomy with LGI1 antibody positivity, B-cell depletion therapy such as intravenous rituximab is an effective treatment.

Metabolites From the Mangrove-Derived Fungus Cladosporium sp. HNWSW-1

Two new benzoic acids, cladoslide A (1) and cladoslide B (2); one new β-carboline derivative, cladospomine (3); and one new pyridin-2(1H)-one, cladoslide C (4), were isolated from the fermentation cultures of the mangrove-derived fungus Cladosporium sp. HNWSW-1, along with the previously reported N-acetyl-β-oxotryptamine (5), (4S,5S,11R)-iso-cladospolide B (6), (4S,5S,11S)-iso-cladospolide B (7), and (4R,5S,11R)-iso-cladospolide B (8). Their structures were elucidated by spectroscopic analysis, Rh₂(OCOCF₃)₄-induced ECD experiments, and Marfey’s method. Compound 1 showed cytotoxicity against the K562 cell line with IC₅₀ values of 13.10 ± 0.08 μM. Moreover, compounds 1 and 5 exhibited inhibitory activity against α-glycosidase with IC₅₀ values of 0.32 ± 0.01 mM and 0.17 ± 0.01 mM, respectively.

[The clinical effect of ultrasonic bone curette-assisted "zoning" style laminectomy for the treatment of severe ossification of thoracic ligamentum flavum]

Objective: To investigate the safety and clinical efficacy of "zoning" style laminectomy by ultrasonic bone curette in patients with severe thoracic ossification of the ligamentum flavum(TOLF). Methods: The clinical data of 36 patients with severe TOLF treated by "zoning" style laminectomy at Department of Spinal Surgery,Zhengzhou Orthopaedic Hospital from October 2015 to October 2018 were respectively analyzed.There were 17 males and 19 females,aged(57.3±10.2)years(range:43 to 80 years).According to the anatomical characteristics of the thoracic ligamentum flavum and the pathological process of ossionization,each decompression segment was divided into the upper 1/3 area of the lamina,the bilateral area of the ossionum flavum,the transitional area,and the area of close contact between the ossionum flavum and the spinal cord.Different surgical strategies were used for decompression in turn.The modified Japanese Orthopedic Association (mJOA) was used to evaluate the neurological function status before and after surgery,to evaluate the surgical effect of patients,and to observe the surgical complications.Paired sample T test was used for data analysis. Results: All 36 patients successfully completed the operation,the operation time was (88.6±24.6) minutes(range:60 to 150 minutes).The intraoperative blood loss was (426.7±167.4) ml(range:250 to 800 ml).Follow-up time was (27.2±7.7) months(range:12 to 48 months).The mJOA score at the last follow-up was 9.0±1.5,which was statistically significant compared with the preoperative score 5.4±1.8 (t=13.59,P<0.01).The improvement rate of mJOA score was (65.7±22.1) %,of which 17 cases were excellent (47.2%),13 cases were good (36.1%),4 cases were normal (11.1%),2 cases were ineffective (5.6%).Ten patients had cerebrospinal fluid leakage during the separation or removal of dural ossification and were cured after a series of comprehensive conservative treatment.Two patients showed transient neurological deterioration,and the neurological function gradually recovered to the preoperative state after comprehensive treatment such as increasing the mean arterial pressure and using neurotrophic drugs.During the follow-up,no aggravation of neurological dysfunction and segmental kyphosis were found. Conclusions: The ultrasonic bone curette-assisted "zoning" style laminectomy for the treatment of severe TOLF can directly observed the position relationship between ossification of the ligamentum flavum and the spinal canal structure during the operation,and accurately guide the surgical decompression.It has the advantages of safe operation and complete decompression,which provides an important reference for the selection of clinical surgery.

Developmental toxicity of cryptotanshinone on the early-life stage of zebrafish development

Cryptotanshinone (Cry) has multiple potential functions in treating different diseases. Most studies on Cry focus on its pharmacological effects and mechanisms, but toxicological reports on Cry are rare. Zebrafish is used as a model organism in drug development as it saves costs and time. This work aimed to investigate the toxicity of Cry on zebrafish. Results showed that growth retardation, pericardial edema, and scoliosis occurred when zebrafish embryos were exposed to Cry, indicating its teratogenic effects. Cell apoptosis was observed in the brainstem area of embryos using acridine orange staining, and qPCR showed that caspase-3 was increased in Cry-exposed embryos. The results of locomotor activity and touched-evoke escape reaction experiments showed that Cry significantly reduced the swimming speed and escape reaction time of larvae.

[Mechanism of high expression of high mobility group protein 1 in a rat model of knee osteoarthritis]

OBJECTIVE

To investigate the molecular mechanism triggering pyroptosis of synovial fibroblast-like synoviocytes(FLSs)and the release of high mobility group protein 1(HMGB1)in a rat model of knee osteoarthritis(KOA).

METHODS

Twelve SD rats were randomized equally into blank control group without any treatment and KOA group with anterior cruciate ligament amputation (ACLT) to induce KOA.HE staining and Mankin score were used to evaluate the damage of knee cartilage.Western blotting was used to detect the expression of pyroptosis-related proteins and HMGB1 in the synovial tissue.In the cell experiment, rat FLSs were treated with PBS (control group), LPS+ATP (to induce cell pyroptosis), or LPS+ATP+siRNAs (to inhibit pyroptosis of the FLSs), and the cellular expressions of apoptosis-related proteins and HMGB1 were detected using Western blotting; the level of HMGB1 in the culture supernatant was detected with ELISA.

RESULTS

In the rat models of KOA, the expressions of pyroptosis-related proteins and HMGB1 in the synovial tissue and Mankin score were significantly increased as compared with those in the control group(P < 0.05).In cultured rat FLSs, the expressions of apoptosis related proteins and HMGB1 were significantly higher in the pyroptosis group than in the control group and in cells transfected with the siRNAs targeting NLRP1, NLRP3, ASC and caspase-1(P < 0.05).The protein level of HMGB1 in the culture supernatant was significantly higher in pyroptosis group than in the control and siRNA groups (P < 0.05).

CONCLUSION

In the pathological process of KOA, NLRPs inflammasome-mediated FLS pyroptosis causes massive release of HMGB1, which is associated with the activation of the downstream molecule caspase-1.

121 Mediating Factors Between Caregiver Burden and Quality of Life in Caregivers of Older Patients with Newly Diagnosed Lung Cancer

Introduction

Family caregivers of older patients with newly diagnosed lung cancer become responsible for patients’ care, usually without preparation or training in provision of care. Their efforts of care generate caregiving burden, which could deteriorate their quality of life and affect the prognosis of patients. The aims of this study were to examine associations between caregiver burden and quality of life, coping, social support for family caregivers, and to investigate whether coping and social support mediate associations between family caregiver burden and their quality of life.

Methods

A cross-sectional study was performed at two thoracic surgery wards in one tertiary hospital in Changsha, China from November 2019 to May 2020. This study involved 224 family caregivers of patients aged over 50 years and newly diagnosed with lung cancer. Caregivers-reported outcomes were measured by Zarit caregiver burden interview, simplified coping style questionnaire, social support rating scale, and quality of life family version. Structural equation modeling (SEM) was used to test the hypothesized mediation model.

Results

SEM indicated a good fit for the mediation model, which explained 49.7% of the variance of quality of life. Higher level of caregivers’ burden was negatively associated with quality of life (r = 0.183, P = 0.042). Coping partially mediated the effect of caregiver burden on quality of life (indirect effect −0.389, P = 0.000). Social support did not mediate the relationship between caregiver burden and quality of life (indirect effect −0.023, P = 0.087).

Conclusions

Caregivers’ burden of patients with newly diagnosed lung cancer is correlated to quality of life which is partially mediated by coping. Early intervention providing caregivers with positive coping strategies may improve their quality of life.

[The low-dose opioids therapy of perioperative multi-mode analgesia is pivotal to the enhanced recovery after surgery for elderly patients]

The implementation of enhanced recovery after surgery in elderly patients should be under the premise of adequate perioperative analgesia/anti-stress. The aims of perioperative multimodal low-dose opioids analgesia therapy are reducing opioid-related adverse reactions and the impact on process of postoperative recovery.

Identification and Characterization of Chalcone Isomerase Genes Involved in Flavonoid Production in Dracaena cambodiana

Dragon's blood is a traditional medicine in which flavonoids are the main bioactive compounds; however, the underlying formation mechanism of dragon's blood remains largely poorly understood. Chalcone isomerase (CHI) is the key enzyme in the flavonoid biosynthesis pathway. However, CHI family genes are not well understood in Dracaena cambodiana Pierre ex Gagnep, an important source plant of dragon's blood. In this study, 11 CHI family genes were identified from D. cambodiana, and they were classified into three types. Evolutionary and transcriptional profiling analysis revealed that DcCHI1 and DcCHI4 might be involved in flavonoid production. Both DcCHI1 and DcCHI4 displayed low expression levels in stem under normal growth conditions and were induced by methyl jasmonate (MeJA), 6-benzyl aminopurine (6-BA, synthetic cytokinin), ultraviolet-B (UV-B), and wounding. The recombinant proteins DcCHI1 and DcCHI4 were expressed in Escherichia coli and purified by His-Bind resin chromatography. Enzyme activity assay indicated that DcCHI1 catalyzed the formation of naringenin from naringenin chalcone, while DcCHI4 lacked this catalytic activity. Overexpression of DcCHI1 or DcCHI4 enhanced the flavonoid production in D. cambodiana and tobacco. These findings implied that DcCHI1 and DcCHI4 play important roles in flavonoid production. Thus, our study will not only contribute to better understand the function and expression regulation of CHI family genes involved in flavonoid production in D. cambodiana but also lay the foundation for developing the effective inducer of dragon's blood.

Genome sequence of the agarwood tree Aquilaria sinensis (Lour.) Spreng: the first chromosome-level draft genome in the Thymelaeceae family

BACKGROUD

Aquilaria sinensis (Lour.) Spreng is one of the important plant resources involved in the production of agarwood in China. The agarwood resin collected from wounded Aquilaria trees has been used in Asia for aromatic or medicinal purposes from ancient times, although the mechanism underlying the formation of agarwood still remains poorly understood owing to a lack of accurate and high-quality genetic information.

FINDINGS

We report the genomic architecture of A. sinensis by using an integrated strategy combining Nanopore, Illumina, and Hi-C sequencing. The final genome was ∼726.5 Mb in size, which reached a high level of continuity and a contig N50 of 1.1 Mb. We combined Hi-C data with the genome assembly to generate chromosome-level scaffolds. Eight super-scaffolds corresponding to the 8 chromosomes were assembled to a final size of 716.6 Mb, with a scaffold N50 of 88.78 Mb using 1,862 contigs. BUSCO evaluation reveals that the genome completeness reached 95.27%. The repeat sequences accounted for 59.13%, and 29,203 protein-coding genes were annotated in the genome. According to phylogenetic analysis using single-copy orthologous genes, we found that A. sinensis is closely related to Gossypium hirsutum and Theobroma cacao from the Malvales order, and A. sinensis diverged from their common ancestor ∼53.18-84.37 million years ago.

CONCLUSIONS

Here, we present the first chromosome-level genome assembly and gene annotation of A. sinensis. This study should contribute to valuable genetic resources for further research on the agarwood formation mechanism, genome-assisted improvement, and conservation biology of Aquilaria species.

Four New Picrotoxane-Type Sesquiterpenes From Dendrobium nobile Lindl

Four picrotoxane-type sesquiterpenes, dendroterpene A–D (1–4), together with four known compounds (5–8), were isolated from the stems of Dendrobium nobile Lindl. Their structures were elucidated by spectroscopic analysis, X-ray diffraction analysis, analysis of the ECD data according to the Klyne's lactone sector rule, and quantum ECD calculation. Compounds 1 and 2 are two new picrotoxane-type sesquiterpenes with a new carbon skeleton containing a formamide group, which may be derived from the previously reported dendrobiumane B skeleton by the C(9)-C(11) carbon bond cleavage. Compounds 3, 5, 6, and 8 exhibited inhibitory activity against α-glycosidase. Compounds 5 and 6 were cytotoxic against SGC-7901, K562, A549, BEL-7402, and Hela cell lines.

Genome survey sequencing for the characterization of genetic background of Dracaena cambodiana and its defense response during dragon's blood formation

Dragon's blood collected from the genus Dracaena is used as a renowned traditional medicine in various cultures worldwide. However, the genetics of the genus Dracaena and the formation mechanism of dragon's blood remain poorly understood. Here, we generate the first draft genome reference assembly of an elite Chinese Dracaena species, Dracaena cambodiana, from next-generation sequencing data with 89.46× coverage. The reads were assembled into 2,640,704 contigs with an N50 length of 1.87 kb, and a 1.05 Gb assembly was finally assembled with 2,379,659 scaffolds. Furthermore, 97.75% of the 267,243 simple sequence repeats identified from these scaffolds were mononucleotide, dinucleotide, and trinucleotide repeats. Among all 53,700 predicted genes, 158 genes involved in cell wall and plant hormone synthesis and reactive oxygen species scavenging showed altered regulation during the formation of dragon's blood. This study provides a genomic characterization of D. cambodiana and improves understanding of the molecular mechanism of dragon's blood formation. This report represents the first genome-wide characterization of a Dracaena species in the Asparagaceae.

Blood flow index as an indicator of successful sciatic nerve block: a prospective observational study using laser speckle contrast imaging

BACKGROUND

Laser speckle contrast imaging allows real-time, non-invasive, quantitative measurements of regional blood flow. The objectives of this prospective observational study were to use laser speckle contrast imaging to evaluate blood flow changes after sciatic nerve block, and to determine whether this novel optical technique can evaluate block success.

METHODS

This observational study included 63 adult patients undergoing elective lower limb surgery with sciatic nerve block. Blood flow images and blood flow index (BFI) values of toes were recorded using laser speckle contrast imaging 5 min before nerve block and at 5 min intervals until 30 min after sciatic block. The sensitivity, specificity, and cut-off value of laser speckle contrast imaging for predicting successful sciatic block were determined by receiver operator characteristic (ROC) curve analysis.

RESULTS

The BFI values of toes were significantly increased at each time point after successful sciatic block, compared with the baseline value obtained 5 min before nerve block; in failed sciatic block, there were no significant differences. For successful sciatic block, the highest increase of BFI value was at the big toe. BFI increase of the big toe at 10 min after sciatic block has great potential as an indicator of block success. The area under the ROC curve was 0.954 at a cut-off value of 8.48 perfusion units (PU) with a sensitivity of 89% and a specificity of 100%.

CONCLUSIONS

Laser speckle contrast imaging might be an early, objective, quantitative, and reliable indicator of successful sciatic block. BFI increase of the big toe not reaching 8.48 PU within 10 min after sciatic block indicates block failure.

CLINICAL TRIAL REGISTRATION

NCT03169517.

New Eudesmane-Type Sesquiterpenoids from the Mangrove-Derived Endophytic Fungus Penicillium sp. J-54

Four new eudesmane-type sesquiterpenoids, penicieudesmol A–D (1–4), were isolated from the fermentation broth of the mangrove-derived endophytic fungus Penicillium sp. J-54. Their structures were determined by spectroscopic methods, the in situ dimolybdenum CD method, and modified Mosher’s method. The bioassays results showed that 2 exhibited weak cytotoxicity against K-562 cells.

Metabolites with Insecticidal Activity from Aspergillus fumigatus JRJ111048 Isolated from Mangrove Plant Acrostichum specioum Endemic to Hainan Island

Fungi residing in mangroves are considered to be a bank of novel bioactive natural products. In the screening for bioactive metabolites from mangrove-derived fungi, the ethyl acetate extract of the fermentation broth of Aspergillus fumigatus JRJ111048, a fungus isolated from the leaves of the mangrove plant Acrostichum specioum endemic to Hainan island, was found to possess insecticidal activity against Spodoptera litura. Bioactivity-guided isolation lead to the discovery of seven metabolites 1–7, including one new anhydride derivative aspergide (1), one new lipid amide 11-methyl-11-hydroxyldodecanoic acid amide (2), and five known compounds; α-ethyl glucoside (3), spiculisporic acid B (4), spiculisporic acid C (5), spiculisporic acid (6), and secospiculisporic acid B (7). Their structures were established by NMR spectroscopic and MS analyses, and by comparison of previously reported data. Insecticidal activity against S. litura and antifungal activity of these compounds were investigated. As a result, the new compound 1 showed potent insecticidal activity against newly hatched larvae of S. litura, and compound 4 displayed weak antifungal activity against Candida albicans.

Susceptibility vessel sign predicts poor clinical outcome for acute stroke patients untreated by thrombolysis

The location and length of the susceptibility vessel sign (SVS) predicts poor outcome for patients having received reperfusion therapy. The aim of the present study was to assess the predictive value of SVS regarding the clinical outcome for patients untreated with thrombolysis. A retrospective study on acute stroke patients who underwent multimodal magnetic resonance imaging within 3 days from the onset of symptoms was performed. None of the patients had received thrombolysis therapy. The presence, location and length of the SVS were assessed. Uni- and multivariate analyses were used to examine the association between SVS and clinical outcome. A total of 43 SVS+ and 73 SVS- patients were included in the study. A modified Rankin Scale (mRS) of ≤2 at 3 months was determined in 41.9% of patients in the SVS+ group and 79.4% in the SVS- group (P<0.001). Multivariate analysis revealed that the presence of SVS was an independent parameter to predict mRS >2 at 3 months (odds ratio, 3.390; 95% confidence interval, 1.122-10.240; P=0.030). For patients with SVS+ status, the location and length of the SVS were not independent predictors of the clinical outcome. In conclusion, the presence of SVS may predict poor clinical outcome for acute stroke patients untreated with thrombolysis.

A novel SYNE1 gene mutation in a Chinese family of Emery-Dreifuss muscular dystrophy-like

BACKGROUND

In the present study, a novel mutation in exon 46 at codon 2304 (G2304R) of the SYNE1 gene is described in a Chinese family (proband, mother, and sister) with Emery-Dreifuss muscular dystrophy-like, which clinically manifests as muscle weakness, muscle atrophy, joint contracture, and without significant cardiac abnormalities.

METHODS

Clinical examination and neuroimaging of the captured target region and high-throughput sequencing were performed in a family of four generations. Muscle changes were evaluated using magnetic resonance imaging and muscle biopsies.

RESULTS

Target region capture sequencing yielded a novel missense mutation in codon 2304 (G2304R), which is a heterozygous A to G point mutation at position 6910 (c.6910A > G) in exon 46 of SYNE1 leading to a glycine-to-arginine substitution (p.Gly2304Arg). The results were also identified by Sanger sequencing in three family members but not in the other three unaffected family members and 100 control subjects.

CONCLUSIONS

This mutation is probably pathogenic and is the first of its kind reported in a familial Emery-Dreifuss muscular dystrophy-like.

Sevoflurane-induced isoelectric EEG and burst suppression: differential and antagonistic effect of added nitrous oxide

The objective of this study was to investigate whether nitrous oxide influenced the ED50 of sevoflurane for induction of isoelectric electroencephalogram (ED50_isoelectric ) differently from its influence on the ED50 of sevoflurane for electroencephalogram burst suppression (ED50_burst ). In a prospective, randomised, double-blind, parallel group, up-down sequential allocation study, 77 ASA physical status 1 and 2 patients received sevoflurane induction and, after tracheal intubation, were randomly allocated to receive sevoflurane with either 40% oxygen in air (control group) or 60% nitrous oxide in oxygen mixture (nitrous group). The ED50_isoelectric in the two groups was determined using Dixon's up and down method, starting at 2.5% with 0.2% step size of end-tidal sevoflurane. The electroencephalogram was considered as isoelectric when a burst suppression ratio of 100% lasted > 1 min. The subsequent concentrations of sevoflurane administered were determined by the presence or absence of isoelectric electroencephalogram in the previous patient in the same group. The ED50_isoelectric in the nitrous group 4.08 (95%CI, 3.95-4.38)% was significantly higher than that in the control group 3.68 (95%CI, 3.50-3.78)% (p < 0.0001). The values for ED50_burst were 3.05 (95%CI, 2.66-3.90)% and 3.02 (95%CI, 3.00-3.05)% in nitrous group and control group, respectively (p = 0.52). The addition of 60% nitrous oxide increases ED50_isoelectric , but not the ED50_burst of sevoflurane. Neither result indicates an additive effect of anaesthetic agents, as might be expected, and possible reasons for this are discussed.

Characterization and Analysis of 2-(2-Phenylethyl)-chromone Derivatives from Agarwood (Aquilaria crassna) by Artificial Holing for Different Times

A total of fifty-six chromones, including seven 5,6,7,8-tetrahydro-2-(2-phenylethyl)-chromones (THPECs), five 5,6-epoxy-2-(2-phenylethyl)chromones (EPECs), seven 5,6:7,8-diepoxy-2-(2-phenylethyl)chromones (DEPECs) and thirty-seven 2-(2-phenylethyl)chromones of the flidersia type (FTPECs), were characterized by HPLC/DAD/ESI/MS/MS in three agarwood samples (from Aquilaria crassna) induced by artificial holing with different holing times. The characteristic fragmentation behavior of DEPECs and EPECs, and the methods to distinguish these four types of chromones by MS analysis were described for the first time. In addition, it was found that the relative contents of DEPECs and EPECs were down-regulated, while the relative contents of THPECs and FTPECs were up-regulated for the samples from two, four and five years of the agarwood formation time. However, the relative contents of six most widespread and abundant FTPECs presented roughly upward based on the formation time. These results could be referenced to distinguish different agarwood samples collected from different formation time.

Fragmentation of protonated 2-(2-phenylethyl)chromones from agarwood: the diagnostic role of ion/neutral complexes as reactive intermediates

A positive-ion electrospray ionisation collision-induced dissociation mass spectrometric study on the fragmentation of the [M + H](+) ions of 2-(2-phenylethyl)chromone and a set of nine hydroxyl- and/or methoxy-substituted derivatives has revealed a highly prominent fragmentation channel, the loss of benzoquinomethanes or a benzaldehyde, respectively, as a diagnostic feature for 2-(2-phenylethyl)chromones that bear a hydroxyl group at the para- (4'-), ortho- (2'-) and/or benzylic (α-) position of the phenylethyl residue. Derivatives that bear only a meta- (3'-) hydroxyl group do not undergo this elimination. The intermediacy of ion/neutral complexes (INCs) is invoked to explain this fragmentation, which involves the remarkable intra-complex proton or hydrogen atom transfer from the remote 4'-OH (or the 2'- or α-OH) functionalities. Density functional theory (B3LYP/6-31G(d)) calculations confirm the energetic preference for these elimination channels and agree with the limited thermochemical data known for para- and ortho- benzoquinomethanes. The INC-mediated losses of the benzaldehydes from the [M + H](+) ions of the α-hydroxy-substituted 2-(2-phenylethyl)chromones correspond to a particularly facile (vinylogous) Grob fragmentation. The study may be viewed as a telling example of the diagnostic role of ion/neutral complexes as intermediates for the structural assignment of constitutional isomers by mass spectrometry.

Effects on specific promoter DNA methylation in zebrafish embryos and larvae following benzo[a]pyrene exposure

Benzo[a]pyrene (BaP) is an established carcinogen and reproductive and developmental toxicant. BaP exposure in humans and animals has been linked to infertility and multigenerational health consequences. DNA methylation is the most studied epigenetic mechanism that regulates gene expression, and mapping of methylation patterns has become an important tool for understanding pathologic gene expression events. The goal of this study was to investigate aberrant changes in promoter DNA methylation in zebrafish embryos and larvae following a parental and continued embryonic waterborne BaP exposure. A total of 21 genes known for their role in human diseases were selected to measure percent methylation by multiplex deep sequencing. At 96hpf (hours post fertilization) compared to 3.3hpf, dazl, nqo1, sox3, cyp1b1, and gstp1 had higher methylation percentages while c-fos and cdkn1a had decreased CG methylation. BaP exposure significantly reduced egg production and offspring survival. Moreover, BaP decreased global methylation and altered CG, CHH, and CHG methylation both at 3.3 and 96hpf. CG methylation changed by 10% or more due to BaP in six genes (c-fos, cdkn1a, dazl, nqo1, nrf2, and sox3) at 3.3hpf and in ten genes (c-fos, cyp1b1, dazl, gstp1, mlh1, nqo1, pten, p53, sox2, and sox3) at 96hpf. BaP also induced gene expression of cyp1b1 and gstp1 at 96hpf which were found to be hypermethylated. Further studies are needed to link aberrant CG, CHH, and CHG methylation to heritable epigenetic consequences associated with disease in later life.

Flavonoids Produced by Tissue Culture of Dracaena cambodiana

Dragon's blood is a traditional medicine used in many countries of many cultures because of its various therapeutic uses, and its main bioactive compounds are flavonoids, which mainly exhibit antitumor and antimicrobial activities. In the process of tissue culture of Dracaena cambodiana, one of its resource plants, red secretion was discovered in the culture when 6-benzylaminopurine was added. Analysis of its constituents by HPLC in comparison with dragon's blood and the standards proved that 17 compounds, including 10 flavonoids, are the same as those in dragon's blood. It is promising that flavonoids from dragon's blood could be produced by tissue culture of its resource plants for the development of new drugs.

A rapid and highly specific method to evaluate the presence of 2-(2-phenylethyl) chromones in agarwood by supercritical fluid chromatography-mass spectrometry

The detection and structural characterization of the major constituents of agarwood, 2-(2-phenylethyl)chromones, are important to quality control and the establishment of the authenticity of agarwood samples. However, a highly specific and rapid method for the evaluation of 2-(2-phenylethy)chromones in agarwood has not been reported to date. In this study, we developed a method using super- critical fluid chromatography in combination with mass spectrometry (SFC-MS). Tropylium ions, the characteristic product ions of 2-(2-phenylethyl)chromones in tandem mass spectrometric experiments, were selected for the targeted detection of 2-(2-phenylethyl) chromones. This method used precursor ion scans for tropylium ions with different possible substitutions on a triple-quadrupole mass spectrometer. To evaluate the usefulness of the developed method, a diethyl ether extract from a Chinese agarwood "Qi-Nan" sample was first separated using SFC, and the elutes were later subjected to precursor ion scans, which searched for 15 common substituted tropylium ions to evaluate the 2-(2-phenylethyl)chromones. In the precursor ion scans, a total of 29 2-(2-phenylethyl)chromones were detected and investigated further using tandem mass spectrometry (MS/MS) to obtain more detailed structural information. By comparing the retention times and m/z values of the precursor ions with reference standards, nine of the detected compounds were unequivocally identified. The remaining compounds were tentatively identified by analyzing the MS/MS spectra. This method provides a rapid and efficient method for evaluating the 2-(2-phenylethyl)chromones present in a sample, which aids in quality control and the establishment of the authenticity of the agarwood sample.

Flavonoids produced by tissue culture of Dracaena cambodiana

Dragon's blood is a traditional medicine used in many countries of many cultures because of its various therapeutic uses, and its main bioactive compounds are flavonoids, which mainly exhibit antitumor and antimicrobial activities. In the process of tissue culture of Dracaena cambodiana, one of its resource plants, red secretion was discovered in the culture when 6-benzylaminopurine was added. Analysis of its constituents by HPLC in comparison with dragon's blood and the standards proved that 17 compounds, including 10 flavonoids, are the same as those in dragon's blood. It is promising that flavonoids from dragon's blood could be produced by tissue culture of its resource plants for the development of new drugs.

Minimal alveolar concentration of sevoflurane for induction of isoelectric electroencephalogram in middle-aged adults

BACKGROUND

We determined the minimal alveolar concentration (MAC) of sevoflurane inducing an isoelectric EEG in 50% of adult subjects (MACie).

METHODS

We included 31 middle-aged subjects; 30 subjects finished the study protocol and received sevoflurane at preselected concentrations according to a modified Dixon 'up-and-down' design starting at 1.7 vol% with 0.2 vol% steps size. General anaesthesia was induced and maintained with sevoflurane; tracheal intubation was facilitated with cisatracurium. After a period of 30 min before skin incision, the state of isoelectric EEG was considered as significant when a burst suppression ratio of 100% lasted for >1 min. The haemodynamic responses to skin incision and the vasopressor requirement to maintain stable haemodynamic status were also analysed according to the EEG state.

RESULTS

MACie was 3.5% (95% confidence interval, 3.4-3.7%) in middle-aged subjects. When compared with subjects not in isoelectric EEG state, subjects in isoelectric EEG state received more phenylephrine to maintain stable haemodynamics (10 of 10 compared with 7 of 20 subjects, P=0.001) and experienced less sympathetic responses to skin incision (1 of 10 compared with 11 of 20 subjects, P=0.024).

CONCLUSIONS

MACie for sevoflurane was ∼2.1 times MAC for immobilization in phenobarbital premedicated middle-aged adults. Sevoflurane-induced isoelectric EEG state is associated with significant cardiovascular depression but reduced haemodynamic responses to skin incision.

Antibacterial Activity against Ralstonia solanacearum of Phenolic Constituents Isolated from Dragon's Blood

Ralstonia solanacearum is a worldwide and devastating plant pathogen infesting over 200 host species. Synthetic bactericides against the pathogen have only achieved limited success and always cause both crop contamination and environmental pollution. However, natural bactericides are effective for protecting cultivated crops from destruction by disease, without the adverse effects of chemical bactericides. In this paper, fifteen phenolic constituents from dragon's blood were screened for their antimicrobial activity against Ralstonia solanacearum, and all exhibited inhibitory activity. These compounds are potential leading compounds for the development of bactericides against wilt diseases caused by Ralstonia solanacearum.