Single Particle Analysis-Enhanced DNA Walking Machine for Sensitive miRNA Detection.

DNA walking machines have achieved significant breakthroughs in areas such as biosensing, bioimaging, and early cancer diagnosis, facilitated by the self-assembly of DNA or its combination with other materials, such as magnetic beads and metal nanoparticles. However, current DNA walking machine strategies are constantly challenged by inadequate analytical sensitivity, while sophisticated signal amplification procedures are often indispensable. Single-particle inductively coupled plasma mass spectrometry (SP-ICPMS) provides superior sensitivity and can effectively discriminate between background noise and detected signals due to the large number of metal atoms in a nanoparticle and the concentrating effect of single nanoparticle detection. In this study, we present a novel approach utilizing single nanoparticle counting and duplex-specific nuclease (DSN)-assisted signal amplification to construct a 3D DNA walking machine for detecting the aggressive prostate cancer (PCa) biomarker miRNA-200c. The proposed strategy showed an improvement in sensitivity with a detection limit (LOD) of 0.93 pM (28 amol) and was successfully applied in human serum samples. To the best of our knowledge, this is the first report of the DNA walking machine with single nanoparticle counting study.

Integrated Optimization of Crystal Facets and Nanoscale Spatial Confinement toward the Boosted Catalytic Performance of Pd Nanocrystals.

Tuning the surface chemical property and the local environment of nanocrystals is crucial for realizing a high catalytic performance in various reactions. Herein, we aim to elucidate the structure sensitivity of Pd facets on the surface catalytic hydrogenation reaction and to identify what role the nanoconfinement effect plays in the catalytic properties of Pd nanocrystal catalysts. By controlling the coating structures of mesoporous silica (mSiO2) on Pd nanocrystals with different exposed facets that include {100}, {111}, and {hk0}, we present a series of Pd@mSiO2 nanoreactors in core-shell and yolk-shell structures and the discovery of a partial-coated structure, which can provide different types of nanoconfinement, and we propose a seed size-dominated growth mechanism. We demonstrate that a superior activity was exhibited in Pd nanocrystals enclosed by the {hk0} facet as compared to the Pd{100} and Pd{111} facets, and substantially enhanced efficiency and stability were achieved in Pd@mSiO2 particles with yolk-shell structures, indicating a crucial superiority of optimizing the configuration of crystal facets and nanoconfinement. Our study provides an efficient strategy to rationally design and optimize nanocatalysts for promoting catalytic performance.

Long-term outcomes of angioplasty for pediatric renovascular hypertension: A single-center experience.

OBJECTIVES: We used single-center data to evaluate the long-term outcome of percutaneous transluminal angioplasty (PTA) for pediatric renovascular hypertension (RVH) and to analyze the factors that influence effectiveness. METHODS: We retrospectively evaluated 33 pediatric RVH patients (18 boys; mean age: 9.1 ± 4 years, range: 2-16) who underwent PTA from January 2007 to December 2019. 15 patients had Takayasu arteritis (TA) and 18 were non-TA. The median follow-up from the initial PTA was 69 months (range: 12-157; IQR: 25.5-89). RESULTS: The technical success rate of 52 PTA procedures was 90.4% in 33 children. Renal artery stents were implanted in two patients, external guidewires were used in two patients, and a drug-coated balloon was used in only one patient. The overall effective rate of PTA was 63.6%, including cured 39.4% and improved 24.2%, at the end of follow-up. Overall clinical outcomes were not statistically different between the TA and non-TA groups (p = 0.316), nor were cure rates (p = 0.072). 15 patients received reintervention due to restenosis after the first successful PTA; the interval was 2-56 months (median: 12 months). Four patients received reintervention due to a failed PTA. A total of four patients received open surgery. Binary logistics regression analysis showed that stenosis length and residual stenosis rate were strongly correlated with effective PTA (p = 0.045, p = 0.044). CONCLUSIONS: As a primary treatment for pediatric RVH, PTA can achieve satisfactory results, which are influenced by lesion length and residual stenosis rate.

Single-Nanoparticle Differential Immunoassay for Multiplexed Gastric Cancer Biomarker Monitoring.

Precision medicine demands the best application of multiple unambiguous biomarkers to bring uniform decisions in disease prognosis. The remarkable development of heterogeneous immunoassay greatly promotes precision medicine when combined with the biomarker combination strategy. Nevertheless, the cumbersome washing steps in heterogeneous immunoassay have inevitably compromised the accuracy because of the sample losses and nature change of the matrix, challenging the further exploration of a more facile and lower limit-of-detection analysis. The new methodologies with high throughputs and specificity are never out of date to provide simultaneous evaluations and uniform decisions on multiple analytes through a simple process. Herein, we propose a new wash-free immunoassay, named differential assay, for multiplexed biomarker monitoring. The method is based on counting the number difference of unbound nanoparticle tags before and after immunoreactions from a solid support (i.e., magnetic microsphere) by single-particle inductively coupled plasma mass spectrometry (sp-ICP-MS), discarding the tedious washing steps. We primarily explore the proof-of-concept proposal within two types (sandwich and competitive assay), demonstrating the good feasibility for further facile clinical practice. To provide efficient multiplexed evaluations, we synthesized PtNPs with four diameters and screened the most suitable size for efficient differential immunoassay. The wash-free strategy was successfully utilized in simultaneous serological biomarker (CA724, CA199, and CEA) evaluation, with results in good accordance with those measured by the clinical routine method. Potentially, the proposed differential bioassay can be regarded as a more facile and valuable tool in malignancy prognosis and cancer recurrence monitoring.

Tissue-specific study across the stem of Taxus media identifies a phloem-specific TmMYB3 involved in the transcriptional regulation of paclitaxel biosynthesis.

Taxus stem barks can be used for extraction of paclitaxel. However, the composition of taxoids across the whole stem and the stem tissue-specificity of paclitaxel biosynthesis-related enzymes remain largely unknown. We used cultivated Taxus media trees for analyses of the chemical composition and protein of major stem tissues by an integrated metabolomic and proteomic approach, and the role of TmMYB3 in paclitaxel biosynthesis was investigated. The metabolomic landscape analysis showed differences in stem tissue-specific accumulation of metabolites. Phytochemical analysis revealed that there is high accumulation of paclitaxel in the phloem. Ten key enzymes involved in paclitaxel biosynthesis were identified, most of which are predominantly produced in the phloem. The full-length sequence of TmMYB3 and partial promoter sequences of five paclitaxel biosynthesis-related genes were isolated. Several MYB recognition elements were found in the promoters of TBT, DBTNBT and TS. Further in vitro and in vivo investigations indicated that TmMYB3 is involved in paclitaxel biosynthesis by activating the expression of TBT and TS. Differences in the taxoid composition of different stem tissues suggest that the whole stem of T. media has potential for biotechnological applications. Phloem-specific TmMYB3 plays a role in the transcriptional regulation of paclitaxel biosynthesis, and may explain the phloem-specific accumulation of paclitaxel.

Omic analysis of the endangered Taxaceae species Pseudotaxus chienii revealed the differences in taxol biosynthesis pathway between Pseudotaxus and Taxus yunnanensis trees.

BACKGROUND: Taxol is an efficient anticancer drug accumulated in Taxus species. Pseudotaxus chienii is an important member of Taxaceae, however, the level of six taxoids in P. chienii is largely unknown. RESULTS: High accumulation of 10-DAB, taxol, and 7-E-PTX suggested that P. chienii is a good taxol-yielding species for large-scale cultivation. By the omics approaches, a total of 3,387 metabolites and 61,146 unigenes were detected and annotated. Compared with a representative Taxus tree (Taxus yunnanensis), most of the differentially accumulated metabolites and differential expressed genes were assigned into 10 primary and secondary metabolism pathways. Comparative analyses revealed the variations in the precursors and intermediate products of taxol biosynthesis between P. chienii and T. yunnanensis. Taxusin-like metabolites highly accumulated in P. chienii, suggesting a wider value of P. chienii in pharmaceutical industry. CONCLUSIONS: In our study, the occurrence of taxoids in P. chienii was determined. The differential expression of key genes involved in the taxol biosynthesis pathway is the major cause of the differential accumulation of taxoids. Moreover, identification of a number of differentially expressed transcription factors provided more candidate regulators of taxol biosynthesis. Our study may help to reveal the differences between Pseudotaxus and Taxus trees, and promote resource utilization of the endangered and rarely studied P. chienii.

Bioactive compounds induced in Physalis angulata L. by methyl-jasmonate: an investigation of compound accumulation patterns and biosynthesis-related candidate genes.

KEY MESSAGE: We employed both metabolomic and transcriptomic approaches to explore the accumulation patterns of physalins, flavonoids and chlorogenic acid in Physalis angulata and revealed the genes associated with the biosynthesis of bioactive compounds under methyl-jasmonate (MeJA) treatment. Physalis angulata L. is an annual Solanaceae plant with a number of medicinally active compounds. Despite the potential pharmacological benefits of P. angulata, the scarce genomic information regarding this plant has limited the studies on the mechanisms of bioactive compound biosynthesis. To facilitate the basic understanding of the main chemical constituent biosynthesis pathways, we performed both metabolomic and transcriptomic approaches to reveal the genes associated with the biosynthesis of bioactive compounds under methyl-jasmonate (MeJA) treatment. Untargeted metabolome analysis showed that most physalins, flavonoids and chlorogenic acid were significantly upregulated. Targeted HPLC-MS/MS analysis confirmed variations in the contents of two important representative steroid derivatives (physalins B and G), total flavonoids, neochlorogenic acid, and chlorogenic acid between MeJA-treated plants and controls. Transcript levels of a few steroid biosynthesis-, flavonoid biosynthesis-, and chlorogenic acid biosynthesis-related genes were upregulated, providing a potential explanation for MeJA-induced active ingredient synthesis in P. angulata. Systematic correlation analysis identified a number of novel candidate genes associated with bioactive compound biosynthesis. These results may help to elucidate the regulatory mechanism underlying MeJA-induced active compound accumulation and provide several valuable candidate genes for further functional study.

Transcriptome analyses provide insights into the expression pattern and sequence similarity of several taxol biosynthesis-related genes in three Taxus species.

BACKGROUND: Taxol is an efficient anticancer drug; however, the accumulation of taxoids can vary hugely among Taxus species. The mechanism underlying differential accumulation of taxoids is largely unknown. Thus, comparative analysis of the transcriptomes in three Taxus species, including T. media, T. mairei and T. cuspidata, was performed. RESULTS: KEGG enrichment analysis revealed that the diterpenoid biosynthesis and cytochrome P450 pathways were significantly enriched in different comparisons. Differential expressions of these taxol biosynthesis related genes might be a potential explanation for the interspecific differential accumulation of taxol and its derivatives. Besides, the sequences of several MEP pathway-associated genes, such as DXS, DXR, MCT, CMK, MDS, HDS, HDR, IPPI, and GGPPS, were re-assembled based on independent transcriptomes from the three Taxus species. Phylogenetic analysis of these MEP pathway-associated enzymes also showed a high sequence similarity between T. media and T. cuspidata. Moreover, 48 JA-related transcription factor (TF) genes, including 10 MYBs, 5 ERFs, 4 RAPs, 3 VTCs, and 26 other TFs, were analyzed. Differential expression of these JA-related TF genes suggested distinct responses to exogenous JA applications in the three Taxus species. CONCLUSIONS: Our results provide insights into the expression pattern and sequence similarity of several taxol biosynthesis-related genes in three Taxus species. The data give us an opportunity to reveal the mechanism underlying the variations in the taxoid contents and to select the highest-yielding Taxus species.

Comparative metabolomic analysis reveals the variations in taxoids and flavonoids among three Taxus species.

BACKGROUND: Trees of the genus Taxus are highly valuable medicinal plants with multiple pharmacological effects on various cancer treatments. Paclitaxel from Taxus trees is an efficient and widely used anticancer drug, however, the accumulation of taxoids and other active ingredients can vary greatly among Taxus species. In our study, the metabolomes of three Taxus species have been investigated. RESULTS: A total of 2246 metabolites assigned to various primary and secondary metabolic pathways were identified using an untargeted approach. Analysis of differentially accumulated metabolites identified 358 T. media-, 220 T. cuspidata-, and 169 T. mairei-specific accumulated metabolites, respectively. By searching the metabolite pool, 7 MEP pathway precursors, 11 intermediates, side chain products and derivatives of paclitaxel, and paclitaxel itself were detected. Most precursors, initiated intermediates were highly accumulated in T. mairei, and most intermediate products approaching the end point of taxol biosynthesis pathway were primarily accumulated in T. cuspidata and T. media. Our data suggested that there were higher-efficiency pathways to paclitaxel in T. cuspidata and T. media compared with in T. mairei. As an important class of active ingredients in Taxus trees, a majority of flavonoids were predominantly accumulated in T. mairei rather than T. media and T. cuspidata. The variations in several selected taxoids and flavonoids were confirmed using a targeted approach. CONCLUSIONS: Systematic correlativity analysis identifies a number of metabolites associated with paclitaxel biosynthesis, suggesting a potential negative correlation between flavonoid metabolism and taxoid accumulation. Investigation of the variations in taxoids and other active ingredients will provide us with a deeper understanding of the interspecific differential accumulation of taxoids and an opportunity to accelerate the highest-yielding species breeding and resource utilization.

[Effect of vinegar processing on esculentosides in n-BuOH fraction and main toxic components in Phytolaccae Radix].

This study was to investigate the effect of vinegar processing on esculentosides in n-BuOH fraction and the contents of the main toxic components esculentoside B (EsB) and esculentoside C (EsC) in Phytolaccae Radix pieces. n-BuOH fraction of Phytolaccae Radix pieces was processed with vinegar according to the processing method in Chinese Pharmacopoeia. HPLC-MS-MS was adopted to analyze the esculentosides composition changes in n-BuOH fraction before and after vinegar processing. HPLC-ELSD was used to detect EsC and EsB contents in raw and vinegar processed Phytolaccae Radix pieces, and investigate the content changes before and after vinegar processing. Results showed that the esculentosides contents in n-BuOH fraction were significantly decreased except esculentoside A (EsA); there were significant changes in saponins compositions, but no new compounds were generated in n-BuOH fraction after vinegar processing. The contents of EsC and EsB were 0.12% and 0.20% respectively in raw Phytolaccae Radix, and decreased to 0.048% and 0.094% accordingly after vinegar processing. It showed that vinegar processing could significantly change the composition of esculentosides in n-BuOH fraction from Phytolaccae Radix and reduce the contents of toxic components EsC and EsB, indicating the scientificity of vinegar processing for Phytolaccae Radix.

[Intestinal toxicity of n-BuOH fraction from Phytolacca Radix before and after being processed with vinegar].

To research the intestinal toxicity of n-BuOH fraction in Phytolacca Radix before and after being processed with vinegar. Toxic n-BuOH fractions were separated from Phytolacca Radix. In the animal model, the level of intestinal edema, water content of intestine and stool, IC50 values of HT-29 and IEC-6 were detected with MTT method to compare the changes in toxicity of n-BuOH fractions from Phytolacca Radix before and after being processed with vinegar. n-BuOH fractions of Phytolacca Radix could cause intestinal edema in mice, increase the edema of duodenum, jejunum and the water content in stool, inhibit the proliferation of HT-29 cells and IEC-6 cells, indicating its intestinal toxicity, with HT-29 IC50 at 14.59 mg•L⁻¹ and IEC-6 IC50 at 43.77 mg•L⁻¹. After being processed with vinegar, the level of intestinal edema, edema of duodenum and jejunum and the water content in stool and inhibition ratio of cells line were reduced, with HT-29 IC50 at 58.51 mg•L⁻¹ and IEC-6 IC50 at 84.37 mg•L⁻¹. After being processed with vinegar, the toxicity of n-BuOH fractions from Phytolacca Radix decreased obviously.

[Antagonism mechanism of gingerols against inflammatory effect of toxic raphides from Pinella pedatisecta].

This study was to investigate the mechanism of gingerols antagonizing the inflammatory effect of toxic raphides from Pinella pedatisecta. Mice peritonitis models induced by toxic raphides from P. pedatisecta were applied to observe the effect of gingerols on inflammatory mediators PGE2 in the exudates of abdominal inflammation in mice; rats peritoneal macrophage in vitro culture models were adopted to study the anti-inflammatory effects of gingerol against toxic raphides, with TNF-α and IL-1ß in supernatant as indexes. Scanning electron microscopy was used to observe the changes in surface morphology of macrophages treated by raphides and gingerols. Macrophages-neutrophils co-cultured models were used to study the antagonism of gingerols against the effect of toxic raphides' stimulation on neutrophils migration. Results showed that gingerols could significantly inhibit the production of PGE2 in the exudates of abdominal inflammation induced by toxic raphides from P. pedatisecta in mice. Gingerols could significantly inhibit the toxic raphides from P. pedatisecta to induce the release of inflammatory factors, with certain dose dependence. Scanning electron microscopy showed that gingerols could significantly inhibit phagocytosis of macrophages, cytomembrane injury, and neutrophils migration induced by toxic raphides from P. pedatisecta. The results showed that the antagonism mechanism of gingerols against the toxic raphides from P. pedatisecta may be associated with inhibiting the pro-inflammatory toxicity including macrophage activation, inflammatory factors release, and neutrophils migration.

Determination of contents of four alkaloids in Pericarpium arecae by quantitative analysis of multi-components by single-marker.

By using a typical component in traditional Chinese medicine Pericarpium Arecae (PA), quantitative analysis of multi-components by single-marker (QAMS) was performed to determine the contents of four alkaloids. With a column packed with strong cation exchange bonded silica particles, the alkaloids were well separated, showing linear relationships within certain ranges. The limit of detection, limit of quantitation, precision, stability, repeatability and recovery all met requirements. By employing arecoline as internal standard, relative correction factors for arecaidine, guvacine and guvacoline at five concentrations were detected with three HPLC systems and three HPLC columns. The peaks of arecaidine, guvacine and guvacoline were positioned, during which the columns with the same packing materials from different manufacturers significantly affected relative retention values and retention time differences of the alkaloids. However, the columns, from different batches, managed to give relative retention values satisfying the requirements of HPLC peak positioning. The Thermo Fisher Scientific column packed with strong cation exchange bonded silica particles was finally selected by considering resolution and peak time. Compared with the external standard method, QAMS detected the alkaloid contents in 12 PA samples more accurately and reliably. The results provide valuable evidence for content determination and quality control of alkaloids in PA.

Characterization and Quantification by LC-MS/MS of the Chemical Components of the Heating Products of the Flavonoids Extract in Pollen Typhae for Transformation Rule Exploration.

The Traditional Chinese Medicine herbs Pollen Typhae and Pollen Typhae Carbonisatus have been used as a hemostatic medicine promoting blood clotting for thousands of years. In this study, a reliable, highly sensitive method based on LC-MS/MS has been developed for differentiation of the heating products of total flavonoids in Pollen Typhae (FPT-N). Twenty three peaks were detected and 18 peaks have been structurally identified by comparing retention times, high resolution mass spectrometry data, and fragment ions with those of the reference substances and/or literature data. Additionally, 15 compounds have been quantified by multiple reaction monitoring in the negative ionization mode. It was found that the contents of the characterized compounds differed greatly from each other in FPT-N samples. Among them, the content of huaicarbon B significantly increased at first, while it decreased after heating for 25 min, which could be considered as the characteristic component for distinguishing FPT-N. The present study provided an approach to rapidly distinguish the differences of FPT-N samples. In addition, the actively summarized characteristic fragmentation might help deducing the structure of unknown flavonols compounds. Furthermore, transformation rules of flavonoids during the heating process in carbonisatus development could contribute to hemostatic therapeutic component exploration.

A Novel Reduplicate Strategy for Tracing Hemostatic Compounds from Heating Products of the Flavonoid Extract in Platycladi cacumen by Spectrum-Effect Relationships and Column Chromatography.

Platycladi cacumen and its processed product have been utilized as a Chinese medicine to treat hemorrhages. In this study, the base peak chromatogram fingerprints of heating products of total flavonoids in Platycladi cacumen were established by high performance liquid chromatography coupled with mass spectroscopy/mass spectroscopy (HPLC-MS/MS), and the hemostatic activities were studied by hemostatic screening tests in vivo. The spectrum-effect relationships between fingerprints and hemostatic activities were analyzed by using canonical correlation analysis to trace the peaks responsible for the significant hemostatic effects. Peak 10 and peak 12 were correlated most closely, thus probably being the main hemostatic compounds. To confirm the reliability of this strategy, the targeted unknown peak was obtained by bioactivity-guided isolation, characterized by MS, ¹H-NMR, (13)C-NMR, and 2D-NMR spectroscopies, and referred to as cecarbon as a new compound. In addition, the isolated compound exhibited hemostatic effect in a dose-dependent manner with different potencies in vitro and existed in Platycladi cacumen Carbonisatus. A novel dereplication strategy was employed to trace and identify the active compounds of other herbs that have bioactivity enhancement after processing using spectrum-effect relationships and column chromatography.

[Totoxicity fraction from Euphorbia pekinensis and composition change after vinegar processing].

To look for the toxicity fraction of Euphorbia pekinensis and discuss the vinegar processing mechanism. The level of intestinal edema, water content of intestine and stool, IC50 values of IEC-6 were applied to evaluate the toxicity of different fractions. RT-PCR was employed for detecting AQP1, AQP3 mRNA expression. The petroleum ether (PE) fraction and ethyl acetate (EtOAc) fraction could significant cause intestinal edema in mice, increase the water content of duodenum, colon and stool, inhibited the mRNA expression of AQP1 and increased the mRNA level of AQP3 in colon, and the petroleum ether (PE) fraction was more poisonous. After the petroleum ether (PE) fraction was processed with vinegar, the level of intestinal edema, water content of duodenum, colon, stool and inhibition ratio of cells line were reduced. And we compared the composition change after vinegar processing, finding that the conpekinensis.

Highly sensitive detection of aflatoxin B1 byCRISPR/Cas12a-assisted single nanoparticle counting.

CRISPR (clustered regularly interspaced short palindromic repeats) and CRISPR-associated protein (Cas) have gained extensive applications in bioassays. However, CRISPR-based detection platforms are often hampered by limited analytical sensitivity, while nucleic acid-based amplification strategies are usually indispensable for additional signal enhancement with potential risks of amplification leakages. To address these challenges, an amplification-free CRISPR-based bioassay of aflatoxin B1 (AFB1) was proposed by applying single nanoparticle counting. Single-particle mode inductively coupled plasma mass spectrometry (Sp-ICPMS) has been regarded as a sensitive tool for nanoparticle counting since one nanoparticle can generate considerable signals above backgrounds. With AFB1, activator strands were introduced to initiate the trans-cleavage of CRISPR/Cas12a for cutting the nanoparticles-tagged-magnetic beads, which were transduced to nanoparticle count signals after separation. Finally, a pico-mole level limit-of-detections (LODs) with moderate selectivity was achieved. Certified reference materials (CRMs) analysis and recovery tests were conducted with promising results. To our best knowledge, this is the first report of the single particle counting-based CRISPR/Cas12a biosensing study.

In vivo evaluation of safety and performance of a tapered nitinol venous stent with inclined proximal end in an ovine iliac venous model.

A tapered stent with inclined proximal end is designed for fitting the iliac anatomically. The aim of the present study was to evaluate the safety and performance of the new stent in ovine left iliac veins. The experiment was performed in 30 adult sheep, and one nitinol-based VENA-BT® iliac venous stent (KYD stent) was implanted into each animal's left common iliac vein. Follow-up in all sheep consisted of angiographic, macroscopic, and microscopic examinations at Day 0 (< 24 h), Day 30, Day 90, Day 180 and Day 360 post-stenting (six animals per each time-point). 30 healthy ~ 50 kg sheep were included in this study and randomly divided into five groups according to the follow-up timepoint. All stents were implanted successfully into the left ovine common iliac vein. No significant migration occurred at follow-up. There is no statistically significant difference between the groups (p > 0.05), indicating no serious lumen loss occurred during the follow-up period. Common iliac venous pressure was further measured and the results further indicated the lumen patency at follow-up. Histological examinations indicated that no vessel injury and wall rupture, stent damage, and luminal thrombus occurred. There was moderate inflammatory cell infiltration around the stent in Day-0 and Day-30 groups with the average inflammation score of 2.278 and 2.167, respectively. The inflammatory reaction was significantly reduced in Day-90, Day-180 and Day-360 groups and the average inflammation scores were 0.9444 (p < 0.001, Day-90 vs Day-0), 1.167 (p < 0.001, Day-180 vs Day-0) and 0.667 (p < 0.001, Day-90 vs Day-0), respectively. The microscopic examinations found that the stents were well covered by endothelial cells in all follow-up time points. The results suggested that the KYD stent is feasible and safe in animal model. Future clinical studies may be required to further evaluate its safety and efficacy.

Role of female-predominant MYB39-bHLH13 complex in sexually dimorphic accumulation of taxol in Taxus media.

Taxus trees are major natural sources for the extraction of taxol, an anti-cancer agent used worldwide. Taxus media is a dioecious woody tree with high taxol yield. However, the sexually dimorphic accumulation of taxoids in T. media is largely unknown. Our study revealed high accumulation of taxoids in female T. media trees using a UPLC-MS/MS method. Thereafter, many differential metabolites and genes between female and male T. media trees were identified using metabolomic and transcriptomic analyses, respectively. Most of the taxol-related genes were predominantly expressed in female trees. A female-specific R2R3-MYB transcription factor gene, TmMYB39, was identified. Furthermore, bimolecular fluorescence complementation and yeast two-hybrid assays suggested the potential interaction between TmMYB39 and TmbHLH13. Several taxol biosynthesis-related promoter sequences were isolated and used for the screening of MYB recognition elements. The electrophoretic mobility shift assay indicated that TmMYB39 could bind to the promoters of the GGPPS, T10OH, T13OH, and TBT genes. Interaction between TmMYB39 and TmbHLH13 transactivated the expression of the GGPPS and T10OH genes. TmMYB39 might function in the transcriptional regulation of taxol biosynthesis through an MYB-bHLH module. Our results give a potential explanation for the sexually dimorphic biosynthesis of taxol in T. media.

Prediction of Left Double-Lumen Tube Size by Measurement of Cricoid Cartilage Transverse Diameter by Ultrasound and CT Multi-Planar Reconstruction.

Background: Currently, there is no uniform standard for selecting the left double lumen tubes (LDLT). Advantages, such as safety and convenience of the ultrasonic technology, and measurement accuracy, make it more widely applied in the clinical anesthesia, and computed tomography (CT) multi-planar reconstruction (MPR) technology will certainly provide a more accurate measurement. For better application for thoracic surgery choice LDLT, relieving the injury to patients, and reducing the complications, this study will compare the two approaches. Methods: The first part, 120 cases of patients were selected according to the height and gender; recording the patient's optimum LDLT and measurement the transverse diameter of the cricoid cartilage (TD-C) by ultrasound and CT MPR, and then obtained the TD-C range measurement by ultrasound and CT MPR corresponding to different types of LDLT. The second part, total of 102 patients were divided into the ultrasound group and the CT MPR group. In the ultrasound group, TD-C was measured by ultrasound, the corresponding size for intubation was selected based on the conclusions derived from the first part. In the CT MPR group, TD-C was measured by CT MPR, the corresponding size of LDLT based on the conclusions derived from the first part. Results: In the first part, 120 patients were no significant difference in the basic characteristics (P > 0.05). The accuracy of selecting the LDLT by conventional experience, namely height and gender was 58.3%. Ultrasonic measurement TD-C range was as follows: 32 Fr <15.88, 35 Fr: 15.88-16.80, 37 Fr: 16.75-17.81, and 39 Fr > 17.80. CT MPR measurement TD-C range was as follows: 32 Fr <15.74, 35 Fr: 15.74-16.65, 37 Fr: 16.56-17.68, and 39 Fr > 17.65. In the second part, there was no significant difference in the basic characteristics between the two groups (P > 0.05). The accuracy of intubation in the ultrasound group was 90.2% and the corresponding in the CT MPR group was 94.1% (P > 0.05). Conclusions: The accuracy of selecting the LDLT based on TD-C is significantly higher than conventional experience; it can significantly reduce the post-operative complications and there was no statistical significance in the accuracy of LDLT selected for TD-C measurement by ultrasound vs. CT, and both of them could be safely used for the evaluation before intubation under anesthesia in thoracic surgery.