Assessing nicotine pharmacokinetics of new generation tobacco products and conventional cigarettes: a systematic review and meta-analysis.

INTRODUCTION: New generation tobacco products (NGPs) hold promises as modified-risk alternatives to conventional cigarettes (CCs), given their comparable characteristics. This study investigated the nicotine pharmacokinetics (PK) of NGPs, encompassing closed pod systems, refillable e-cigarettes (ECs), and heated tobacco products (HTPs), in comparison to CCs through systematic review and meta-analysis. METHODS: A comprehensive search was conducted on PubMed, Embase, and Web of Science for articles published between January 2013 and July 2023. Maximum nicotine concentration (Cmax), time to the peak concentration (Tmax), and total nicotine exposure (area under the concentration-time curve, AUC) were extracted to evaluate nicotine delivery PK. Random effects meta-analyses were performed to determine pooled standardized mean differences (SMD), facilitating a comparison of PK profiles between NGPs and CCs. Subgroup analyses exploring flavors and nicotine concentrations across NGPs, and CCs were also conducted. RESULTS: The meta-analysis incorporated 30 articles with 2728 participants. Cmax and AUC were significantly lower for NGPs, while Tmax demonstrated statistical similarity compared to CCs. Among three NGPs, Cmax and AUC were lower for closed pod systems and refillable ECs. In HTPs, Cmax was statistically similar while AUC was lower compared to CCs. Tmax was statistically similar in closed pod systems and HTPs compared to that of CCs. No significant difference was observed in the comparisons of PK between each type of NGPs versus CCs. CONCLUSIONS: NGPs delivered less nicotine than CCs but reached Cmax over a similar timeframe, indicating that NGPs may serve as modified-risk alternatives with lower nicotine delivery to CCs for craving relief and smoking cessation. IMPLICATION: This study suggested that NGPs, such as the closed pod systems, the refillable ECs, and the HTPs, delivered either lower or comparable nicotine levels and achieved peak nicotine concentration at a similar rate as CCs. Our findings carry implications that NGPs can serve as modified-risk nicotine alternative to CCs in helping smokers to manage cravings and potentially quit smoking, thereby highlighting their value in the field of tobacco harm reduction.

Integrative comparison of the genomic and transcriptomic landscape between prostate cancer patients of predominantly African or European genetic ancestry.

Men of predominantly African Ancestry (AA) have higher prostate cancer (CaP) incidence and worse survival than men of predominantly European Ancestry (EA). While socioeconomic factors drive this disparity, genomic factors may also contribute to differences in the incidence and mortality rates. To compare the prevalence of prostate tumor genomic alterations and transcriptomic profiles by patient genetic ancestry, we evaluated genomic profiles from The Cancer Genome Atlas (TCGA) CaP cohort (n = 498). Patient global and local genetic ancestry were estimated by computational algorithms using genotyping data; 414 (83.1%) were EA, 61 (12.2%) were AA, 11 (2.2%) were East Asian Ancestry (EAA), 10 (2.0%) were Native American (NA), and 2 (0.4%) were other ancestry. Genetic ancestry was highly concordant with self-identified race/ethnicity. Subsequent analyses were limited to 61 AA and 414 EA cases. Significant differences were observed by ancestry in the frequency of SPOP mutations (20.3% AA vs. 10.0% EA; p = 5.6×10-03), TMPRSS2-ERG fusions (29.3% AA vs. 39.6% EA; p = 4.4×10-02), and PTEN deletions/losses (11.5% AA vs. 30.2% EA; p = 3.5×10-03). Differentially expressed genes (DEGs) between AAs and EAs showed significant enrichment for prostate eQTL target genes (p = 8.09×10-48). Enrichment of highly expressed DEGs for immune-related pathways was observed in AAs, and for PTEN/PI3K signaling in EAs. Nearly one-third of DEGs (31.3%) were long non-coding RNAs (DE-lncRNAs). The proportion of DE-lncRNAs with higher expression in AAs greatly exceeded that with lower expression in AAs (p = 1.2×10-125). Both ChIP-seq and RNA-seq data suggested a stronger regulatory role for AR signaling pathways in DE-lncRNAs vs. non-DE-lncRNAs. CaP-related oncogenic lncRNAs, such as PVT1, PCAT1 and PCAT10/CTBP1-AS, were found to be more highly expressed in AAs. We report substantial heterogeneity in the prostate tumor genome and transcriptome between EA and AA. These differences may be biological contributors to racial disparities in CaP incidence and outcomes.

Characterization of trichome-specific BAHD acyltransferases involved in acylsugar biosynthesis in Nicotiana tabacum.

Glandular trichomes of tobacco (Nicotiana tabacum) produce blends of acylsucroses that contribute to defence against pathogens and herbivorous insects, but the mechanism of assembly of these acylsugars has not yet been determined. In this study, we isolated and characterized two trichome-specific acylsugar acyltransferases that are localized in the endoplasmic reticulum, NtASAT1 and NtASAT2. They sequentially catalyse two additive steps of acyl donors to sucrose to produce di-acylsucrose. Knocking out of NtASAT1 or NtASAT2 resulted in deficiency of acylsucrose; however, there was no effect on acylsugar accumulation in plants overexpressing NtASAT1 or NtASAT2. Genomic analysis and profiling revealed that NtASATs originated from the T subgenome, which is derived from the acylsugar-producing diploid ancestor N. tomentosiformis. Our identification of NtASAT1 and NtASAT2 as enzymes involved in acylsugar assembly in tobacco potentially provides a new approach and target genes for improving crop resistance against pathogens and insects.

The effect of information literacy heterogeneity on epidemic spreading in information and epidemic coupled multiplex networks.

With the COVID-19 pandemic, better understanding of the co-evolution of information and epidemic diffusion networks is important for pandemic-related policies. Using the microscopic Markov chain method, this study proposed an aware-susceptible-infected model (ASI) to explore the effect of information literacy on the spreading process in such multiplex networks. We first introduced a parameter that adjusts the self-protection related execution ability of aware individuals in order to emphasis the importance of protective behaviors compared to awareness in decreasing the infection probability. The model also captures individuals' heterogeneity in their information literacy. Simulation experiments found that the high information-literate individuals are more sensitive to information adoption. In addition, epidemic information can help to suppress the epidemic diffusion only when individuals' abilities of transforming awareness into actual protective behaviors attain a threshold. In communities dominated by highly literate individuals, a larger information literacy gap can improve awareness acquisition and thus help to suppress the epidemic among the whole group. By contrast, in communities dominated by low information-literate individuals, a smaller information literacy gap can better prevent the epidemic diffusion. This study contributes to the literature by revealing the importance of individuals' heterogeneity of information literacy on epidemic spreading in different communities and has implications for how to inform people when a new epidemic disease emerges.

A deletion in the RD105 region confers resistance to multiple drugs in Mycobacterium tuberculosis.

BACKGROUND: The emergence of drug-resistant strains of Mycobacterium tuberculosis (Mtb), especially those that are multidrug resistant poses a serious threat to global tuberculosis control. However, the mechanism underlying the occurrence of drug resistance against more than one drug is poorly understood. Given that the Beijing/W strains are associated with outbreaks and multidrug resistance, they may harbor a genetic advantage and provide useful insight into the disease. One marker found in all Beijing/W Mtb strains is a deletion of RD105 region that results in a gene fusion, Rv0071/74, with a variable number (3-9 m) of VDP (V: Val, D: Asp; P: Pro) repeats (coded by gtggacccg repeat sequences) at the N-terminal. Here, we report that this variable number of VDP repeats in Rv0071/74 regulates the development of multidrug resistance. RESULTS: We collected and analyzed 1255 Beijing/W clinical strains. The results showed that the number of VDP repeats in Rv0071/74 was related to the development of multidrug resistance, and the deletion of Rv0071/74-9 m from Beijing/W clinical strain restored drug susceptibility. Rv0071/74-9 m also increased resistance to multiple drugs when transferred to different mycobacterial strains. Cell-free assays indicate that the domain carrying 4-9 VDP repeats (4-9 m) showed a variable binding affinity with peptidoglycan and Rv0071/74 cleaves peptidoglycan. Furthermore, Rv0071/74-9 m increased cell wall thickness and reduced the intracellular concentration of antibiotics. CONCLUSIONS: These findings not only identify Rv0071/74 with VDP repeats as a newly identified multidrug resistance gene but also provide a new model for the development of multiple drug resistance.

Targeting the lysosome by an aminomethylated Riccardin D triggers DNA damage through cathepsin B-mediated degradation of BRCA1.

RD-N, an aminomethylated derivative of riccardin D, is a lysosomotropic agent that can trigger lysosomal membrane permeabilization followed by cathepsin B (CTSB)-dependent apoptosis in prostate cancer (PCa) cells, but the underlying mechanisms remain unknown. Here we show that RD-N treatment drives CTSB translocation from the lysosomes to the nucleus where it promotes DNA damage by suppression of the breast cancer 1 protein (BRCA1). Inhibition of CTSB activity with its specific inhibitors, or by CTSB-targeting siRNA or CTSB with enzyme-negative domain attenuated activation of BRCA1 and DNA damage induced by RD-N. Conversely, CTSB overexpression resulted in inhibition of BRCA1 and sensitized PCa cells to RD-N-induced cell death. Furthermore, RD-N-induced cell death was exacerbated in BRCA1-deficient cancer cells. We also demonstrated that CTSB/BRCA1-dependent DNA damage was critical for RD-N, but not for etoposide, reinforcing the importance of CTSB/BRCA1 in RD-N-mediated cell death. In addition, RD-N synergistically increased cell sensitivity to cisplatin, and this effect was more evidenced in BRCA1-deficient cancer cells. This study reveals a novel molecular mechanism that RD-N promotes CTSB-dependent DNA damage by the suppression of BRCA1 in PCa cells, leading to the identification of a potential compound that target lysosomes for cancer treatment.

Cyclin D1 silencing impairs DNA double strand break repair, sensitizes BRCA1 wildtype ovarian cancer cells to olaparib.

OBJECTIVE: Poly(ADP-ribose) polymerase inhibitors (PARPi) are active in cancer cells that have impaired repair of DNA by the homologous recombination (HR) pathway. Strategies that disrupt HR may sensitize HR-proficient tumors to PARP inhibition. As a component of the core cell cycle machinery, cyclin D1 has unexpected function in DNA repair, suggesting that targeting cyclin D1 may represent a plausible strategy for expanding the utility of PARPi in ovarian cancer. METHODS: BRCA1 wildtype ovarian cancer cells (A2780 and SKOV3) were treated with a combination of CCND1 siRNA and olaparib in vitro. Cell viability was assessed by MTT. The effects of the combined treatment on DNA damage repair and cell cycle progression were examined to dissect molecular mechanisms. In vivo studies were performed in an orthotopic ovarian cancer mouse model. Animals were treated with a combination of lentivirus-mediated CCND1 shRNA and olaparib or olaparib plus scrambled shRNA. Molecular downstream effects were examined by immunohistochemistry. RESULTS: Silencing of cyclin D1 sensitized ovarian cancer cells to olaparib through interfering with RAD51 accumulation and inducing cell cycle G0/G1 arrest. Treatment of lentivirus-mediated CCND1-shRNA in nude mice statistically significantly augmented the olaparib response (mean tumor weight ±â€¯SD, CCND1-shRNA plus olaparib vs scrambled shRNA plus olaparib: 0.172 ±â€¯0.070 g vs 0.324 ±â€¯0.044 g, P< 0.05). CONCLUSIONS: Silencing of cyclin D1 combined with olaparib may lead to substantial benefit for ovarian cancer management by mimicking a BRCAness phenotype, and induction of G0/G1 cell cycle arrest.

Integrative Analyses of Nontargeted Volatile Profiling and Transcriptome Data Provide Molecular Insight into VOC Diversity in Cucumber Plants (Cucumis sativus).

Plant volatile organic compounds, which are generated in a tissue-specific manner, play important ecological roles in the interactions between plants and their environments, including the well-known functions of attracting pollinators and protecting plants from herbivores/fungi attacks. However, to date, there have not been reports of holistic volatile profiling of the various tissues of a single plant species, even for the model plant species. In this study, we qualitatively and quantitatively analyzed 85 volatile chemicals, including 36 volatile terpenes, in 23 different tissues of cucumber (Cucumis sativus) plants using solid-phase microextraction combined with gas chromatography-mass spectrometry. Most volatile chemicals were found to occur in a highly tissue-specific manner. The consensus transcriptomes for each of the 23 cucumber tissues were generated with RNA sequencing data and used in volatile organic compound-gene correlation analysis to screen for candidate genes likely to be involved in cucumber volatile biosynthetic pathways. In vitro biochemical characterization of the candidate enzymes demonstrated that TERPENE SYNTHASE11 (TPS11)/TPS14, TPS01, and TPS15 were responsible for volatile terpenoid production in the roots, flowers, and fruit tissues of cucumber plants, respectively. A functional heteromeric geranyl(geranyl) pyrophosphate synthase, composed of an inactive small subunit (type I) and an active large subunit, was demonstrated to play a key role in monoterpene production in cucumber. In addition to establishing a standard workflow for the elucidation of plant volatile biosynthetic pathways, the knowledge generated from this study lays a solid foundation for future investigations of both the physiological functions of cucumber volatiles and aspects of cucumber flavor improvement.

Screening and identification of immunoactive peptide mimotopes for the enhanced serodiagnosis of tuberculosis.

Although serological detection is a practical strategy for early detection and diagnosis of tuberculosis (TB), inconsistent and imprecise estimates of sensitivity and specificity block its development and application for clinic. New or alternative serological antigens with improved accuracy are urgently needed. A phage-displayed random peptide library was employed to screen for immunoactive peptides using specific immunoglobulin G (IgG) of TB patients as target molecules. With two screening strategies, 20 single phages displaying different sequences were obtained and no sequence homology was found among these phages. From the results of phage-ELISA, H12, TB6, TB15, and TB18 phages showed higher affinity to IgGs from TB patients(S/N ≥2.1) and were identified as the positive clones. Significant differences in the detection values of sera from 47 TB patients and 37 healthy individuals were found for these four phage clones. According to the reactivity of 284 human sera to synthetic H12, TB6, TB15, and TB18 peptides as determined by ELISA, TB15 showed significantly higher areas under the curve (AUC) and sensitivity than other peptides, providing a lead molecule for the development of new serology diagnostic strategies for TB.

Bisbibenzyls, novel proteasome inhibitors, suppress androgen receptor transcriptional activity and expression accompanied by activation of autophagy in prostate cancer LNCaP cells.

CONTEXT: Bisbibenzyl compounds have gained our interests for their potential antitumor activity in malignant cell-types. OBJECTIVE: The objective of this study is to investigate the effect of bisbibenzyl compounds riccardin C (RC), marchantin M (MM), and riccardin D (RD) on androgen receptor (AR) in prostate cancer (PCa) cells. MATERIALS AND METHODS: After exposure to 10 µM of the compounds for 24 h, cell cycle and cell survival analyses were performed using FACS and MTT assay to confirm the effect of these bisbibenzyls on PCa LNCaP cells. Changes in the AR expression and function, as the result of exposure to the compounds, were investigated using real-time PCR, ELISA, transient transfection, western blotting (WB), immunoprecipitation, and immunofluorescence staining (IF). Chemical-induced autophagy was examined by WB, IF, and RNAi. RESULTS: RC, MM, and RD reduced the viability of LNCaP cells accompanied with arrested cell cycle in the G0/G1 phase and induction of apoptosis. Further investigation revealed that these compounds significantly inhibited AR expression at mRNA and protein levels, leading to the suppression of AR transcriptional activity. Moreover, inhibition of proteasome activity by bisbibenzyls, which in turn caused the induction of autophagy, as noted by induction of LC3B expression, conversion, and accumulation of punctate dots in treated cells. Co-localization of AR/LC3B and AR/Ub suggested that autophagy contributed to the degradation of polyubiquitinated-AR when proteasome activity was suppressed by the bisbibenzyls. DISCUSSION AND CONCLUSION: Suppression of proteasome activity and induction of autophagy were involved in bisbibenzyl-mediated modulation of AR activities and apoptosis, suggesting their potential in treating PCa.

Identification and application of ssDNA aptamers against H37Rv in the detection of Mycobacterium tuberculosis.

Microscopy of direct smear with the Ziehl-Neelsen stain is still broadly used in tuberculosis diagnosis. However, this method suffers from low specificity and is difficult to distinguish Mycobacterium tuberculosis (MTB) from nontuberculosis mycobacterial (NTM), since all mycobacterial species are positive in Ziehl-Neelsen stain. In this study, we utilized whole cell SELEX to obtain species-specific aptamers for increasing the specificity of MTB detection. Whole cell SELEX was performed in MTB reference strain H37Rv by two selection processes based on enzyme-linked plate or Eppendorf tube, respectively. To increase success rate of generating aptamers, the selection processes were systematically monitored to understand the dynamic evolution of aptamers against complex structure of target bacteria. Two preponderant groups and ten high-affinity aptamers were obtained by analyzing the dynamic evolution. Preponderant aptamer MA1 from group I showed relatively high binding affinity with apparent dissociation constant (KD value) of 12.02 nM. Sandwich ELISA assay revealed five aptamer combinations effectively bound MTB strains in preliminary evaluation, especially the combination based on aptamer MA2 (another preponderant aptamer from group II) and MA1. Further evaluated in many other strains, MA2/MA1 combination effectively identified MTB from NTM or other pathogenic bacteria, and displayed the high specificity and sensitivity. Binding analysis of aptamer MA1 or MA2 by fluorescence microscopy observation showed high binding reactivity with H37Rv, low apparent cross-reactivity with M. marinum, and no apparent cross-reactivity with Enterobacter cloacae. Taken together, this study provides attractive candidate species-specific aptamers to effectively capture or discriminate MTB strains.

Mutations in the embC-embA intergenic region contribute to Mycobacterium tuberculosis resistance to ethambutol.

The rapid increase in Mycobacterium tuberculosis resistance to ethambutol (EMB) threatens the diagnosis and treatment of tuberculosis (TB). We investigated the role of mutations in the embC-embA intergenic region (IGR) in EMB-resistant clinical strains from east China. A total of 767 M. tuberculosis clinical strains were collected and analyzed for their drug susceptibility to EMB using the MGIT 960 system and MIC assay, and the embC-embA IGRs of these strains were sequenced. The transcriptional activity of the embC-embA IGR mutations was examined by reporter gene assays in recombinant Mycobacterium smegmatis strains, and the effect of IGR mutations on its binding to EmbR, a transcription regulator of embAB, was analyzed by gel mobility shift assays. Correlation coefficient analysis showed that the embC-embA IGR mutation is associated with EMB resistance. The clinical strains carrying IGR mutations had a much higher level of embA and embB mRNA as well as higher MICs to EMB. IGR mutations had higher transcriptional activity when transformed into M. smegmatis strains. Mutated IGRs bound to EmbR with much higher affinity than wild-type fragments. The sensitivity of molecular drug susceptibility testing (DST) with IGR mutations as an additional marker increased from 65.5% to 73.5%. Mutations of the embC-embA IGR enhance the binding of EmbR to the promoter region of embAB and increase the expression of embAB, thus contributing to EMB resistance. Therefore, identification of IGR mutations as markers of EMB resistance could increase the sensitivity of molecular DST.

Diagnostic accuracy of a molecular drug susceptibility testing method for the antituberculosis drug ethambutol: a systematic review and meta-analysis.

Ethambutol (EMB) is a first-line antituberculosis drug; however, drug resistance to EMB has been increasing. Molecular drug susceptibility testing (DST), based on the embB gene, has recently been used for rapid identification of EMB resistance. The aim of this meta-analysis was to establish the accuracy of molecular assay for detecting drug resistance to EMB. PubMed, Embase, and Web of Science were searched according to a written protocol and explicit study selection criteria. Measures of diagnostic accuracy were pooled using a random effects model. A total of 34 studies were included in the meta-analysis. The respective pooled sensitivities and specificities were 0.57 and 0.93 for PCR-DNA sequencing that targeted the embB 306 codon, 0.76 and 0.89 for PCR-DNA sequencing that targeted the embB 306, 406, and 497 codons, 0.64 and 0.70 for detecting Mycobacterium tuberculosis isolates, 0.55 and 0.78 for detecting M. tuberculosis sputum specimens using the GenoType MTBDRsl test, 0.57 and 0.87 for pyrosequencing, and 0.35 and 0.98 for PCR-restriction fragment length polymorphism. The respective pooled sensitivities and specificities were 0.55 and 0.92 when using a lower EMB concentration as the reference standard, 0.67 and 0.73 when using a higher EMB concentration as the reference standard, and 0.60 and 1.0 when using multiple reference standards. PCR-DNA sequencing using multiple sites of the embB gene as detection targets, including embB 306, 406, and 497, can be a rapid method for preliminarily screening for EMB resistance, but it does not fully replace phenotypic DST. Of the reference DST methods examined, the agreement rates were the best using MGIT 960 for molecular DST and using the proportion method on Middlebrook 7H10 media.

Pyrosequencing for rapid detection of tuberculosis resistance in clinical isolates and sputum samples from re-treatment pulmonary tuberculosis patients.

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) is a major public health problem. Early diagnosis of MDR-TB patients is essential for minimizing the risk of Mycobacterium tuberculosis (MTB) transmission. The conventional drug susceptibility testing (DST) methods for detection of drug-resistant M. tuberculosis are laborious and cannot provide the rapid detection for clinical practice. METHODS: The aim of this study was to develop a pyrosequencing approach for the simultaneous detection of resistance to rifampin (RIF), isoniazid (INH), ethambutol (EMB), streptomycin (SM), ofloxacin (OFL) and amikacin (AMK) in M. tuberculosis clinical isolates and sputum samples from re-treatment pulmonary tuberculosis (PTB) patients. We identified the optimum conditions for detection mutation of rpoB, katG, rpsl, embB, gyrA and rrs gene by pyrosequencing. Then this approach was applied to detect 205 clinical isolates and 24 sputum samples of M. tuberculosis from re-treatment PTB patients. RESULTS: The mutations of rpoB and gyrA gene were detected by pyrosequencig with the SQA mode, and the mutations of katG, rpsl, embB, gyrA and rrs gene were detected by pyrosequencing with SNP mode. Compared with the Bactec MGIT 960 mycobacterial detection system, the accuracy of pyrosequencing for the detection of RIF, INH, EMB, SM, AMK and OFL resistance in clinical isolates was 95.0%, 79.2%, 70.3%, 84.5%, 96.5% and 91.1%, respectively. In sputum samples the accuracy was 83.3%, 83.3%, 60.9%, 83.3%, 87.5% and 91.7%, respectively. CONCLUSIONS: The newly established pyrosequencing assay is a rapid and high-throughput method for the detection of resistance to RIF, INH, SM, EMB, OFL and AMK in M. tuberculosis. Pyrosequencing can be used as a practical molecular diagnostic tool for screening and predicting the resistance of re-treatment pulmonary tuberculosis patients.

Multistep-ahead air passengers traffic prediction with hybrid ARIMA-SVMs models.

The hybrid ARIMA-SVMs prediction models have been established recently, which take advantage of the unique strength of ARIMA and SVMs models in linear and nonlinear modeling, respectively. Built upon this hybrid ARIMA-SVMs models alike, this study goes further to extend them into the case of multistep-ahead prediction for air passengers traffic with the two most commonly used multistep-ahead prediction strategies, that is, iterated strategy and direct strategy. Additionally, the effectiveness of data preprocessing approaches, such as deseasonalization and detrending, is investigated and proofed along with the two strategies. Real data sets including four selected airlines' monthly series were collected to justify the effectiveness of the proposed approach. Empirical results demonstrate that the direct strategy performs better than iterative one in long term prediction case while iterative one performs better in the case of short term prediction. Furthermore, both deseasonalization and detrending can significantly improve the prediction accuracy for both strategies, indicating the necessity of data preprocessing. As such, this study contributes as a full reference to the planners from air transportation industries on how to tackle multistep-ahead prediction tasks in the implementation of either prediction strategy.

Characterization of the third SERK gene in pineapple (Ananas comosus) and analysis of its expression and autophosphorylation activity in vitro.

Two somatic embryogenesis receptor-like kinase genes (identified as AcSERK1 and AcSERK2) have previously been characterized from pineapple (Ananas comosus). In this work, we describe the characterization of a third gene (AcSERK3) in this family. AcSERK3 had all the characteristic domains and shared extensive sequence homology with other plant SERKs. AcSERK3 expression was studied by in situ hybridization and quantitative real-time PCR to analyze its function. Intense in situ hybridization signals were observed only in single competent cells and competent cell clusters; no hybridization signal was detected in the subsequent stages of somatic embryogenesis. AcSERK3 was highly expressed in embryogenic callus compared to other organs, e.g., 20-80 fold more than in anther but similar to that of non-embryogenic callus, which was 20-50 fold that of anther. AcSERK3 expression in root was 80 fold higher than in anther and the highest amongst all organs tested. These results indicate that AcSERK3 plays an important role in callus proliferation and root development. His-tagged AcSERK3 protein was successfully expressed and the luminescence of His6-AcSERK3 protein was only ∼5% of that of inactivated AcSERK3 protein and reaction buffer without protein, and 11.3% of that of an extract of host Escherichia coli pET-30a. This finding confirmed that the AcSERK3 fusion protein had autophosphorylation activity.

[Screening and identification of C7C peptide ligands of Mycobacterium tuberculosis].

OBJECTIVE: To obtain the C7C peptide ligands of Mycobacterium tuberculosis by affinity screening based on the phage-displayed random C7C peptide library, and preliminarily identify the binding capacity of the peptide to Mycobacterium. METHODS: Inactive Mycobacterium tuberculosis reference strain H37Rv was used as the target molecule to screen the Ph. D.-C7C peptide library, and Mycobacterium bovis, BCG was used for reverse screening. After 4 rounds of affinity screening, single phages eluted by H37Rv and BCG were selected for DNA sequencing. ELISA was used to detect the binding affinities of different single phage clones. The cyclic peptides displayed by the phage clones showing the highest appetency were synthesized in vitro with fluorescent markers. Fluorescence microscopy and flow cytometer was used to detect the binding affinities of synthesized cyclic peptides, comparing with linear binding peptides obtained before. RESULTS: After 4 rounds of biopanning, phages that could bind with target molecules were remarkable enriched. 16 common sequences were obtained by sequencing analysis of single phages. With ELISA, phage SB1, SB5, SB8 and SB26 all showed higher affinity with H37Rv and BCG, the ratio to negative control of which were ≥ 2.1, but could not bind to the 3 nonmycobacteria, which were identified as the positive clones. Based on the results of flow cytometer detection, the affinities to H37Rv of 4 cyclic peptides SB1, SB5, SB24, SB26 were (73.2 ± 6.3)%, (63.2 ± 5.3)%, (32.9 ± 3.1)%, (89.4 ± 7.0)%, and to BCG were (65.6 ± 6.1)%, (48.6 ± 4.5)%, (10.3 ± 1.8)%, (86.6 ± 7.9)%, separately, which were all higher than H8 ((4.0 ± 1.0)%, (5.5 ± 1.2)%) . From the results of fluorescence microscopy observation, all of the fluorescent labeled cyclic peptides SB1, SB5, SB24, SB26 could bind to H37Rv and showed higher fluorescence intensities, which also had certain affinities to other 18 mycobacteria, but the fluorescence intensities were lower than H37Rv, and didn't bind to 3 non-mycobacteria. CONCLUSION: Based on the replacement of linear 7 peptide library with C7C peptide library, new ligands of Mycobacterium tuberculosis were achieved successfully, which showed significantly higher binding affinities to mycobacteria.

[Induction in vitro and stability of Mycobacterium tuberculosis resistance to ofloxacin].

OBJECTIVE: To induce Mycobacterium tuberculosis (MTB) resistance with ofloxacin (Ofx) of stepwise increasing concentration in vitro, investigate stability to fluoroquinolone (FQs) antibiotic of MTB, and analyze the molecular mechanism and mutation specialty of drug resistance preliminarily. METHODS: MTB Standard strain H37RV and 24 clinical isolates susceptible to Ofx were selected and experimentally serially subcultured in liquid culture medium containing increasing concentration of Ofx and induced the drug resistance to Ofx. Variety of Minimal Inhibitory Concentrations (MICs) to FQs drugs were detected by microwell-MIC-test method. Mutations of quinolone resistance determining region (QRDR) of gyrA gene were sequenced and identified. Relationship of different mutation sites and drug resistant degree were analyzed. A total of 6 MTB clinical isolates resistant to Ofx and induced drug resistant isolates in vitro were serially subcultured in liquid culture medium without drug. Variety of drug resistant stability, including MIC and mutation of gyrA gene were detected. RESULTS: MIC values of 21 Ofx susceptible isolates after induction were eight times higher than before, which were induced to drug resistant strains successfully and also resistant to Lfx and Mfx. Hot mutations of QRDR of gyrA gene were detected by sequencing, except one strain. Mutation of codon 94 occurred in 60% (12/20) of the strains with mutations and corresponding value of 50% Minimal Inhibitory Concentrations(MIC50) was ≥ 8 µg/ml. In all, 4 of 6 MTB clinical isolates resistant to Ofx harbored mutation of codon 90 (67%) , but the corresponding value of MIC50 was 2 µg/ml. After 21 serially subcultured in liquid culture medium without drug, MIC values of 6 clinical isolates resistant to Ofx were not changed obviously and mutations were also not changed. After 11 times serially subcultured in culture medium without drug, MIC values of induced drug resistant strains were also not changed obviously, but new mutations were detected in QRDR of 3 isolates. CONCLUSION: MTB strains resistant to three kinds of FQs antibiotic were obtained by induction in vitro with Ofx. Codons 88, 94 mutations of QRDR of gyrA gene were related to the high level FQs drug resistance of MTB. Drug resistant stability of MTB to FQs was strong, and it is difficult for MTB to resume susceptibility.

[Evaluation of the RNA simultaneous amplification and testing for detection of rifampin resistance in Mycobacterium tuberculosis].

OBJECTIVE: To establish and evaluate a method for detection of rifampin resistance in Mycobacterium tuberculosis (M. tuberculosis) by the RNA simultaneous amplification and testing (SAT). METHODS: RNA probe and primer of reverse transcription with T7 promoter targets pre-16S rRNA were designed, and the isothermal RNA amplification at 42 °C was performed for real-time detection of the levels of pre-16S rRNA in drug exposed MTB. Twenty clinical isolates were detected by the SAT after treatment with rifampicin 1, 2 and 3 d in order to determine the best drug effect time. Fifty clinical isolates with known drug susceptibility results were used to determine the best cutoff value of rifampicin drug susceptibility by SAT. In total, 128 clinical isolates were detected by SAT to evaluate the accuracy compared with the Bactec MGIT 960. RESULTS: The best drug effect time and cutoff value for the detection of rifampin resistance by SAT were 2 d and 2.95. With the result of Bactec MGIT 960 as the reference, the sensitivity and the specificity of the assay was 100% (51/51) and 97.4% (75/77), respectively. CONCLUSIONS: The isothermal RNA amplification assay is a highly sensitive and specific tool for the detection of rifampicin resistance in M. tuberculosis, and therefore, it may be a new method to detect rifampicin resistance in M. tuberculosis.

Path Planning of Unmanned Aerial Vehicles Based on an Improved Bio-Inspired Tuna Swarm Optimization Algorithm.

The Sine-Levy tuna swarm optimization (SLTSO) algorithm is a novel method based on the sine strategy and Levy flight guidance. It is presented as a solution to the shortcomings of the tuna swarm optimization (TSO) algorithm, which include its tendency to reach local optima and limited capacity to search worldwide. This algorithm updates locations using the Levy flight technique and greedy approach and generates initial solutions using an elite reverse learning process. Additionally, it offers an individual location optimization method called golden sine, which enhances the algorithm's capacity to explore widely and steer clear of local optima. To plan UAV flight paths safely and effectively in complex obstacle environments, the SLTSO algorithm considers constraints such as geographic and airspace obstacles, along with performance metrics like flight environment, flight space, flight distance, angle, altitude, and threat levels. The effectiveness of the algorithm is verified by simulation and the creation of a path planning model. Experimental results show that the SLTSO algorithm displays faster convergence rates, better optimization precision, shorter and smoother paths, and concomitant reduction in energy usage. A drone can now map its route far more effectively thanks to these improvements. Consequently, the proposed SLTSO algorithm demonstrates both efficacy and superiority in UAV route planning applications.