Recent advances in lycopene and germacrene a biosynthesis and their role as antineoplastic drugs.

Sesquiterpenes and tetraterpenes are classes of plant-derived natural products with antineoplastic effects. While plant extraction of the sesquiterpene, germacrene A, and the tetraterpene, lycopene suffers supply chain deficits and poor yields, chemical synthesis has difficulties in separating stereoisomers. This review highlights cutting-edge developments in producing germacrene A and lycopene from microbial cell factories. We then summarize the antineoplastic properties of ß-elemene (a thermal product from germacrene A), sesquiterpene lactones (metabolic products from germacrene A), and lycopene. We also elaborate on strategies to optimize microbial-based germacrene A and lycopene production.

Engineering Escherichia coli BL21 (DE3) for high-yield production of germacrene A, a precursor of ß-elemene via combinatorial metabolic engineering strategies.

ß-elemene is one of the most commonly used antineoplastic drugs in cancer treatment. As a plant-derived natural chemical, biologically engineering microorganisms to produce germacrene A to be converted to ß-elemene harbors great expectations since chemical synthesis and plant isolation methods come with their production deficiencies. In this study, we report the design of an Escherichia coli cell factory for the de novo production of germacrene A to be converted to ß-elemene from a simple carbon source. A series of systematic approaches of engineering the isoprenoid and central carbon pathways, translational and protein engineering of the sesquiterpene synthase, and exporter engineering yielded high-efficient ß-elemene production. Specifically, deleting competing pathways in the central carbon pathway ensured the availability of acetyl-coA, pyruvate, and glyceraldehyde-3-phosphate for the isoprenoid pathways. Adopting lycopene color as a high throughput screening method, an optimized NSY305N was obtained via error-prone polymerase chain reaction mutagenesis. Further overexpression of key pathway enzymes, exporter genes, and translational engineering produced 1161.09 mg/L of ß-elemene in a shake flask. Finally, we detected the highest reported titer of 3.52 g/L of ß-elemene and 2.13 g/L germacrene A produced by an E. coli cell factory in a 4-L fed-batch fermentation. The systematic engineering reported here generally applies to microbial production of a broader range of chemicals. This illustrates that rewiring E. coli central metabolism is viable for producing acetyl-coA-derived and pyruvate-derived molecules cost-effectively.

Metabolic engineering strategies for sesquiterpene production in microorganism.

Sesquiterpenes are a large variety of terpene natural products, widely existing in plants, fungi, marine organisms, insects, and microbes. Value-added sesquiterpenes are extensively used in industries such as: food, drugs, fragrances, and fuels. With an increase in market demands and the price of sesquiterpenes, the biosynthesis of sesquiterpenes by microbial fermentation methods from renewable feedstocks is acquiring increasing attention. Synthetic biology provides robust tools of sesquiterpene production in microorganisms. This review presents a summary of metabolic engineering strategies on the hosts and pathway engineering for sesquiterpene production. Advances in synthetic biology provide new strategies on the creation of desired hosts for sesquiterpene production. Especially, metabolic engineering strategies for the production of sesquiterpenes such as: amorphadiene, farnesene, bisabolene, and caryophyllene are emphasized in: Escherichia coli, Saccharomyces cerevisiae, and other microorganisms. Challenges and future perspectives of the bioprocess for translating sesquiterpene production into practical industrial work are also discussed.

Improving the imaging diagnostic strategy for pulmonary artery masses based on 18F-FDG PET/CT integrated with CTPA.

OBJECTIVE: To evaluate the diagnostic accuracy of computed tomography pulmonary angiography (CTPA) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for pulmonary artery (PA) masses. METHODS: Of 2889 patients with PA filling defects of PA on CTPA, 79 consecutive patients suspicious for PA malignancy who subsequently underwent 18F-FDG PET/CT were enrolled. All masses were diagnosed on the basis of pathological findings or clinical imaging follow-up. For each mass, morphological CT signs, standardized uptake value (SUVmax and SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) on 18F-FDG PET/CT were used as diagnostic markers. RESULTS: Expansive growth, irregular margin, invasion, CT contrast uptake, and wall eclipse sign were strongly associated with the malignant nature of masses. The coexistence of at least 5 CT signs perfectly identified malignant masses, whereas the detection of no more than 4 CT signs did not accurately discriminate between the natures of masses. Mean SUVmax, SUVmean, MTV, and TLG values were significantly higher in malignant masses compared to those in benign masses. The diagnostic accuracy of 18F-FDG PET/CT parameters (SUV, MTV, and TLG) was excellent in detecting malignant masses. Among patients with 3 or 4 pathological CT signs, SUVmax > 3.4 significantly increased the identification of malignancies. CONCLUSIONS: CTPA is a useful imaging modality for diagnosing PA masses, especially when at least 5 abnormal CT signs are identified. Similarly, 18F-FDG PET/CT accurately identified malignant masses and provided additional valuable information on diagnostic uncertainties after CTPA.

Immobilization of D-allulose 3-epimerase into magnetic metal-organic framework nanoparticles for efficient biocatalysis.

D-allulose is a rare low-calorie sugar that has many fundamental biological functions. D-allulose 3-epimerase from Agrobacterium tumefaciens (AT-DAEase) catalyzes the conversion of D-fructose to D-allulose. The enzyme has attracted considerable attention because of its mild catalytic properties. However, the bioconversion efficiency and reusability of AT-DAEase limit its industrial application. Magnetic metal-organic frameworks (MOFs) have uniform pore sizes and large surface areas and can facilitate mass transport and enhance the capacity for enzyme immobilization. Here, we successfully encapsulated cobalt-type AT-DAEase into the cobalt-based magnetic MOF ZIF-67@Fe3O4 using a self-assembly strategy. We confirmed the immobilization of enzyme AT-DAEase and characterized the enzymatic properties of the MOF-immobilized AT-DAEase@ZIF-67@Fe3O4. The AT-DAEase@ZIF-67@Fe3O4 nanoparticles had higher catalytic activity (65.1 U mg-1) and bioconversion ratio (38.1%) than the free AT-DAEase. The optimal conditions for maximum enzyme activity of the AT-DAEase@ZIF-67@Fe3O4 nanoparticles were 55 °C and pH 8.0, which were significantly higher than those of the free AT-DAEase (50 °C and pH 7.5). The AT-DAEase@ZIF-67@Fe3O4 nanoparticles displayed significantly improved thermal stability and excellent recycling performance, with 80% retention of enzyme activity at a temperature range of 45-70 °C and > 45% of its initial activity after eight cycles of enzyme use. The AT-DAEase@ZIF-67@Fe3O4 nanoparticles have great potential for large-scale industrial preparation of D-allulose by immobilizing cobalt-type AT-DAEase into magnetic MOF ZIF-67@Fe3O4.

Hymenobacter sediminis sp. nov., isolated from lake sediment.

A Gram-stain-negative, facultatively aerobic, rod-shaped, motile by gliding and pink-pigmented bacterial strain, designated ELS1360T, was isolated from a lake sediment sample collected in Inner Mongolia, PR China. Strain ELS1360T grew optimally at 33 °C, at pH 6.5-7.0 and without NaCl. Strain ELS1360T exhibited 97.3, 97.1 and 96.9 % 16S rRNA gene sequence similarities to Hymenobacter aquatilis HMF3095T, Hymenobacter luteus JCM 30328T and Hymenobacter latericoloratus JCM 30327T, respectively, and 90.4-96.9 % to other members of the genus Hymenobacter. Results of phylogenetic analysis based on 16S rRNA gene sequences showed that strain ELS1360T belonged to the genus Hymenobacter and clustered with H. luteus JCM 30328T and H. latericoloratus JCM 30327T. The predominant cellular fatty acids were iso-C15:0, summed feature 3 and C16:1ω5c. Strain ELS1360T contained MK-7 as the sole menaquinone. The major polar lipids contained phosphatidylethanolamine and two unidentified lipids. The genomic DNA G+C content of strain ELS1360T was 57.1 mol%. Based on the results of our phylogenetic, phenotypic, genotypic and chemotaxonomic analyses, it is concluded that strain ELS1360T represents a novel species within the genus Hymenobacter, for which the name Hymenobacter sediminis sp. nov. is proposed. The type strain is ELS1360T (=KCTC 62449T=MCCC 1H00319T).

Paracnuella aquatica gen. nov., sp. nov., a member of the family Chitinophagaceae isolated from a hot spring.

A Gram-stain-negative, rod-shaped bacterium (designated strain N24T) with gliding motility was isolated from thermal spring water sampled at Xi'an, PR China. Cells were 0.4-0.8 µm wide and 1.8-7.8 µm long. Optimal growth occurred at 33 °C and pH 7.0 on Reasoner's 2A (R2A) agar. Strain N24T could produce exopolysaccharide on R2A agar at 33 °C. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain N24T formed a distinct phyletic lineage within the family Chitinophagaceae and was most closely related to members of the genera Flavisolibacter, Cnuella, Niveitalea, Flavitalea, Flaviaesturariibacter and Niastella with 91.7-93.9 % 16S rRNA gene sequence similarities. The major fatty acids of strain N24T were iso-C15 : 0 (31.8 %), iso-C17 : 0 3-OH (16.1 %) and iso-C15 : 1 G (12.9 %). The polar lipid profile consisted of phosphatidylethanolamine, two aminolipids and six unknown lipids; the quinone system consisted of menaquinone-7 (MK-7). The genomic G+C content was 49.3 mol%. On the basis of the evidence presented in this study, strain N24T represents a novel species of a new genus in the family Chitinophagaceae, for which the name Paracnuella aquatica gen. nov., sp. nov. is proposed. The type species is N24T (=KCTC 62083T=MCCC 1H00301T).

Engineering and manipulation of a mevalonate pathway in Escherichia coli for isoprene production.

Isoprene is a useful phytochemical with high commercial values in many industrial applications including synthetic rubber, elastomers, isoprenoid medicines, and fossil fuel. Currently, isoprene is on large scale produced from petrochemical sources. An efficient biological process for isoprene production utilizing renewable feedstocks would be an important direction of research due to the fossil raw material depletion and air pollution. In this study, we introduced the mevalonate (MVA) pathway genes/acetoacetyl-coenzyme A thiolase (mvaE) and MVA synthase (mvaS) from Enterococcus faecalis (E. faecalis); MVA kinase (mvk) derived from Methanosarcina mazei (M. mazei); and phosphomevalonate kinase (pmk), diphosphomevalonate decarboxylase (mvaD), and isopentenyl diphosphate isomerase (idi) from Streptococcus pneumoniae (S. pneumoniae) to accelerate dimethylallyl diphosphate (DMAPP) accumulation in Escherichia coli (E. coli). Together with a codon-optimized isoprene synthase (ispS) from Populus alba (P. alba), E. coli strain succeeded in formation of isoprene. We then manipulated the heterologous MVA pathway for high-level production of isoprene, by controlling the gene expression levels of the MVA pathway genes. We engineered four E. coli strains which showed different gene expression levels and different isoprene productivities, and we also characterized them with quantitative real-time PCR and metabolite analysis. To further improve the isoprene titers and release the toxicity to cells, we developed the extraction fermentation by adding dodecane in cultures. Finally, strain BL2T7P1TrcP harboring balanced gene expression system produced 587 ± 47 mg/L isoprene, with a 5.2-fold titer improvement in comparison with strain BL7CT7P. This work indicated that a balanced metabolic flux played a significant role to improve the isoprene production via MVA pathway.

Solasodine reverses stemness and epithelial-mesenchymal transition in human colorectal cancer.

Adverse side effects of conventional chemotherapy, acquired resistance and fatal tumor metastasis of human colorectal cancer (CRC) are propelling the exploration for novel selective anticarcinogens. Solasodine is a main active component isolated from Solanum incanum L that exhibited a potent stemness and invasion inhibitory effect on human colorectal cancer HCT116 cells. Colony Spheroid formation assay showed that solasodine dose-dependently prohibited HCT116 cell stemness. CD133, CD44, Nanog, Oct-4 and Sox-2 were inhibited by solasodine to reverse stemness and similar mechanism was stimulated in vivo. Transwell and scratch wound assays revealed that solasodine impeded HCT116 cell invasion and migration potential strengthened by TGF-ß1. Moreover, solasodine attenuated TGF-ß1-induced EMT and decreased MMPs while in vivo study showed the same trend. The results of this study implied that solasodine may be a novel therapeutic drug for CRC treatment.

Winogradskyella tangerina sp. nov., a member of the Flavobacteriaceae isolated from coastal sediment.

A Gram-stain-negative, rod-shaped bacterium (designated strain M1309T), with slow gliding motility, was isolated from marine sediment obtained off the coast of Weihai, PR China. The growth of M1309T was observed at 16-42 °C (optimum, 37 °C) and pH 6.5-8.0 (optimum, 7.0-7.5) in the presence of 2.0-6.0 % (w/v) NaCl (optimum, 2.0-3.0 %). Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the strain represented a member of the genus Winogradskyella. M1309T exhibited the highest 16S rRNA gene sequence similarity, of 95.5 %, to Winogradskyella poriferorum JCM 12885T. Chemotaxonomic analysis revealed that the sole respiratory quinone was menaquinone 6 (MK-6) and the major fatty acids included iso-C15 : 0, iso-C15 : 1G and iso-C17 : 0 3-OH. The major polar lipids included phosphatidylethanolamine, two aminolipids, and three unidentified lipids. The DNA G+C content of the strain was 36.1 mol%. On the basis of phenotypic distinctiveness and phylogenetic divergence, strain M1309T is considered to represent a novel species of the genus Winogradskyella, for which the name Winogradskyella tangerina sp. nov. is proposed. The type strain is M1309T (=KCTC 52896T=MCCC 1K03310T).

A novel DMAPP-responding genetic circuit sensor for high-throughput screening and evolving isoprene synthase.

High-throughput screening is a popular tool for collating biological data which would otherwise require the use of excessive resources. In this study, an artificial genetic circuit sensor responding to dimethylallyl diphosphate (DMAPP) was constructed based on a modified L-arabinose operon for high-throughput screening and isoprene synthase (ispS) evolution in Escherichia coli (E. coli). As a first step, the DNA sequence of the L-arabinose ligand-binding domain (LBD) was replaced with an ispS gene to enable the AraC operon responding to DMAPP, which is the substrate of the IspS enzyme. Then, an enhanced GFP (eGFP) was also introduced as a reporter for pBAD promoter. The expression level of the reporter was monitored using either of the two tools: flow cytometer (FCM) and microplate reader. Sequentially, we observed that a high DMAPP concentration led to low eGFP fluorescence, and the overexpression of ispS gene, which consumes DMAPP, resulted in a high eGFP expression. These results demonstrated that the artificial genetic circuit sensor responded directly to the intracellular concentration of DMAPP, and the expression of IspS enzyme could be positively correlated to the expression level of eGFP. Finally, we identified two IspS mutants with different activities from an ispS gene library and further validated the screening method.

Prevalence and its associated psychological variables of symptoms of depression and anxiety among ovarian cancer patients in China: a cross-sectional study.

BACKGROUND: It is well known that cancer patients tend to have high levels of perceived stress and symptoms of depression and anxiety. However, there is less study on the association between perceived stress and symptoms of depression and anxiety among ovarian cancer patients in China. And the mediating effect of hope and resilience needs to be further studied. In this study, we aim to examine the prevalence of depression and anxiety symptoms, to analyze the association between perceived stress and symptoms of depression and anxiety, and to test whether hope and resilience mediate the association of perceived stress with symptoms of depression and anxiety among Chinese patients with ovarian cancer. METHOD: A total of 220 questionnaires were distributed and collected from the First Affiliated Hospital of China Medical University and Shengjing Hospital of China Medical University. All participants in this study were ovarian cancer inpatients. After excluding the incomplete questionnaires, 198 questionnaires were valid for the analysis. Qualified patients were asked to response to the questionnaires including Hospital anxiety and depression scale (HADS), perceived stress scale (PSS-10), and the Herth hope scale and the resilience scale. Hierarchical regression analyses were used to test the associations among perceived stress, symptoms of depression and anxiety, and hope and resilience. Bootstrapping method was conducted to examine whether the indirect effect of hope and resilience was significant respectively. RESULTS: The prevalence of symptoms of depression and anxiety in ovarian cancer patients was 47.0% and 51.5% respectively. Perceived stress correlated significantly with symptoms of depression (r = 0.709, P < 0.01) and anxiety (r = 0.660, P < 0.01). Hope (a*b = 0.155, BCa 95% CI: 0.094, 0.223) partly mediated the association between perceived stress and symptoms of depression; similarly, hope (a*b = 0.129, BCa 95% CI: 0.048, 0.205) partly mediated the effect of perceived stress on symptoms of anxiety. However, resilience (a*b = 0.004, BCa 95% CI: -0.030, 0.040) did not mediate the association between perceived stress and symptoms of depression. And resilience (a*b = 0.041,BCa 95% CI: -0.013, 0.098) did not mediate the association between perceived stress and symptoms of anxiety. CONCLUSIONS: The present study suggests that perceived stress might be one of the impact factors of symptoms of depression and anxiety, while hope might ease symptoms of depression and anxiety. In view of the role of hope, medical workers and patient caregivers should pay more attention to hope, and then to intervene perceived stress among patients with ovarian cancer.

[Relationship between R236C site in exon 7 of SP-B gene and respiratory distress syndrome in Han newborns in western Inner Mongolia].

OBJECTIVE: To detect and analyze the genetic variation in exon 7 of lung surfactant protein B (SP-B), and to investigate the relationship between the genetic variation and the incidence of neonatal respiratory distress syndrome (NRDS) in Han populations in western Inner Mongolia. METHODS: In the case-control study, 47 Han infants with NRDS were assigned to case group. All the 47 patients had the last three generations of their ancestors reside in western Inner Mongolia. Forty-seven Han newborns without NRDS were assigned to control group. PCR-based gene analysis was used to determine the mutation in exon 7 of SP-B gene and genotype and allele frequencies of the R236C site in exon 7 of SP-B gene. RESULTS: In Han newborns in western Inner Mongolia, there was no mutation in exon 7 of SP-B gene; two genotypes, CC and CT, were identified in the R236C site in exon 7 of SP-B gene. No TT genotype was found in the two groups. There were no significant differences in the genotype frequency of CC or CT as well as the allele frequency of C or T between the case and control groups (CC: 72% vs 85%, P>0.05; CT: 28% vs 15%, P>0.05; C: 85% vs 93%, P>0.05; T: 15% vs 7%, P>0.05). CONCLUSIONS: There is no mutation in exon 7 of SP-B gene in Han infants with NRDS in western Inner Mongolia. There is no significant association between the gene polymorphism of the R236C site in exon 7 of SP-B gene and the incidence of NRDS in Han populations in that region.

Early evaluation of carotid elasticity by an instantaneous wave intensity technique in patients with systemic lupus erythematosus.

OBJECTIVES: To explore the application of instantaneous wave intensity for early diagnosis of systemic lupus erythematosus (SLE)-induced atherosclerosis, we observed carotid elasticity by instantaneous wave intensity in premenopausal women with SLE. METHODS: The study included 3 groups (each group with 30 participants): SLE1 (course of disease <5 years), SLE2 (course of disease ≥5 years) and healthy control. Carotid parameters, including instantaneous acceleration wave intensity, instantaneous deceleration wave intensity, negative area, stiffness constant, wave intensity pulse wave velocity, stiffness constant pulse wave velocity, pressure strain elastic modulus, arterial compliance, augmentation index, and intima-media thickness, were measured. RESULTS: Compared with the control group, the instantaneous deceleration wave intensity, stiffness constant, pressure strain elastic modulus, wave intensity pulse wave velocity, and stiffness constant pulse wave velocity were significantly increased but the arterial compliance was significantly decreased in the SLE1 and SLE2 groups (all P ≤ .01). The instantaneous acceleration wave intensity, augmentation index, and negative area tended to increase in all 3 groups, but there were no statistical differences among the groups. The instantaneous deceleration wave intensity, stiffness constant, pressure strain elastic modulus, wave intensity pulse wave velocity, and stiffness constant pulse wave velocity were significantly higher in the SLE2 group than the SLE1 group, but the arterial compliance was significantly lower in the SLE2 group than the SLE1 group (all P ≤ .01). CONCLUSIONS: Instantaneous wave intensity can be used to evaluate carotid elasticity in the patients with SLE, which is important for early prevention and treatment of cardiovascular disease.

Correlation and interaction visualization of altmetric indicators extracted from scholarly social network activities: dimensions and structure.

BACKGROUND: Citation counts for peer-reviewed articles and the impact factor of journals have long been indicators of article importance or quality. In the Web 2.0 era, growing numbers of scholars are using scholarly social network tools to communicate scientific ideas with colleagues, thereby making traditional indicators less sufficient, immediate, and comprehensive. In these new situations, the altmetric indicators offer alternative measures that reflect the multidimensional nature of scholarly impact in an immediate, open, and individualized way. In this direction of research, some studies have demonstrated the correlation between altmetrics and traditional metrics with different samples. However, up to now, there has been relatively little research done on the dimension and interaction structure of altmetrics. OBJECTIVE: Our goal was to reveal the number of dimensions that altmetric indicators should be divided into and the structure in which altmetric indicators interact with each other. METHODS: Because an article-level metrics dataset is collected from scholarly social media and open access platforms, it is one of the most robust samples available to study altmetric indicators. Therefore, we downloaded a large dataset containing activity data in 20 types of metrics present in 33,128 academic articles from the application programming interface website. First, we analyzed the correlation among altmetric indicators using Spearman rank correlation. Second, we visualized the multiple correlation coefficient matrixes with graduated colors. Third, inputting the correlation matrix, we drew an MDS diagram to demonstrate the dimension for altmetric indicators. For correlation structure, we used a social network map to represent the social relationships and the strength of relations. RESULTS: We found that the distribution of altmetric indicators is significantly non-normal and positively skewed. The distribution of downloads and page views follows the Pareto law. Moreover, we found that the Spearman coefficients from 91.58% of the pairs of variables indicate statistical significance at the .01 level. The non-metric MDS map divided the 20 altmetric indicators into three clusters: traditional metrics, active altmetrics, and inactive altmetrics. The social network diagram showed two subgroups that are tied to each other but not to other groups, thus indicating an intersection between altmetrics and traditional metric indicators. CONCLUSIONS: Altmetrics complement, and most correlate significantly with, traditional measures. Therefore, in future evaluations of the social impact of articles, we should consider not only traditional metrics but also active altmetrics. There may also be a transfer phenomenon for the social impact of academic articles. The impact transfer path has transfer, or intermediate, stations that transport and accelerate article social impact from active altmetrics to traditional metrics and vice versa. This discovery will be helpful to explain the impact transfer mechanism of articles in the Web 2.0 era. Hence, altmetrics are in fact superior to traditional filters for assessing scholarly impact in multiple dimensions and in terms of social structure.

Two sodium(I) coordination polymers constructed by the V-shaped ligands 2,2'-[isopropylidenebis(1,4-phenyleneoxy)]diacetic acid and 2,2'-[sulfonylbis(1,4-phenyleneoxy)]diacetic acid.

Two new inorganic-organic coordination polymers, namely poly[[µ6-2-(4-{1-[4-(carboxymethoxy)phenyl]-1-methylethyl}phenoxy)acetato][µ4-2-(4-{1-[4-(carboxymethoxy)phenyl]-1-methylethyl}phenoxy)acetato]disodium(I)], [Na2(C19H19O6)2]n, (I), and poly[hexa-µ-aqua-diaquabis{µ3-2,2'-[sulfonylbis(1,4-phenyleneoxy)]diacetato}tetrasodium(I)], [Na4(C16H14O8)2(H2O)8]n, (II), have been prepared. In (I), the asymmetric unit contains two Na(I) cations and two 2-(4-{1-[4-(carboxymethoxy)phenyl]-1-methylethyl}phenoxy)acetate (HL1(-)) ligands. Each Na(I) cation is octahedrally coordinated by two ether O atoms and four carboxylate O atoms of three different HL1(-) ligands. The NaO6 polyhedra share edges to form an inorganic ribbon along the a axis. These inorganic ribbons are further connected by the HL1(-) ligands to generate two-dimensional layers parallel to the (001) plane. The structure of (II) consists of ribbons of four crystallographically independent Na atoms (three six- and one five-coordinate), which are bridged by carboxylate O atoms of 4,4'-[sulfonylbis(1,4-phenyleneoxy)]diacetate (L2(2-)) ligands and water molecules. These ribbons are interlinked by L2(2-) ligands through two different coordination modes to afford a three-dimensional network.

[Effects of echinacoside on extracellular acetylcholine and choline levels of hippocampus and striatum of cerebral ischemia rats].

The aim of this study is to investigate the effect of echinacoside (ECH) on cholinergic neurotransmitter extracellular of hippocampus and striatum and its possible mechanisms of neuro-protective effect against vascular dementia rats. In this study brain microdialysis technique combined with HPLC-IMER-ECD (high-performance liquid chromatography-immobilized enzyme reactor-electrochemical detector) was used. The bilateral common carotid arteries occluded in two times operation at 72 h interval for vascular dementia model rats were used and the successful vascular dementia model rats were examined by Morris water maze. The content of acetylcholine (ACh) and choline (Ch) of microdialysate extracellular of hippocampus and striatum was determined by HPLC-IMER-ECD and the AChE activity in the hippocampus was measured. The results showed that the success rate of vascular dementia model was 83.08% after six weeks; the results also showed that echinacoside and galantamine could increase the content of ACh and reduce the content of Ch extracellular of hippocampus and striatum significantly and the AChE activity increased significantly compared with that of the model group. The results suggested that echinacoside could promote the recovery of cholinergic neurotransmitter levels in vascular dementia rats' brain, which may be one of the mechanisms of neuro-protection.

[Bronchoesophageal fistula secondary to mediastinal lymph node tuberculosis: a case report and review of the literature].

OBJECTIVE: To analyze the clinical features of 1 case of bronchoesophageal fistula (BEF) secondary to mediastinal lymph node tuberculosis. METHODS: The clinical, auxiliary examinational and pathological data of 1 case with BEF were presented, and the literatures were reviewed. RESULTS: The patient was a 19 year old female, who was admitted to hospital because of fever and cough associated with liquid intake. It was diagnosed by chest CT scan, endobronchial ultrasound biopsy of mediastinal lymph nodes, and clinical testing (methylene blue). The BEF was closed after anti-tuberculosis therapy and preventing contamination of the fistula by indwelling stomach tube. CONCLUSIONS: Bronchoesophageal fistula secondary to mediastinal lymph node tuberculosis is rare. Chest CT scan, fiberoptic bronchoscopy, and clinical testing (methylene blue) are useful diagnostic tools for BEF.

Improved Membrane Permeability via Hypervesiculation for In Situ Recovery of Lycopene in Escherichia coli.

Lycopene biosynthesis is frequently hampered by downstream processing hugely due to its inability to be secreted out from the producing chassis. Engineering cell factories can resolve this issue by secreting this hydrophobic compound. A highly permeable E. coli strain was developed for a better release rate of lycopene. Specifically, the heterologous mevalonate pathway and crtEBI genes from Corynebacterium glutamicum were overexpressed in Escherichia coli BL21 (DE3) for lycopene synthesis. To ensure in situ lycopene production, murein lipoprotein, lipoprotein NlpI, inner membrane permease protein, and membrane-anchored protein in TolA-TolQ-TolR were deleted for improved membrane permeability. The final strain, LYC-8, produced 438.44 ± 8.11 and 136.94 ± 1.94 mg/L of extracellular and intracellular lycopene in fed-batch fermentation. Both proteomics and lipidomics analyses of secreted outer membrane vesicles were perfect indicators of hypervesiculation. Changes in the ratio of saturated fatty acids, unsaturated fatty acids, and cyclopropane fatty acids coupled with the branching and acyl chain lengths altered the membrane fatty acid composition. This ensured membrane fluidity and permeability for in situ lycopene release. The combinatorial deletion of these genes altered the cellular morphology. The structural and morphological changes in cell shape, size, and length were associated with changes in the mechanical strength of the cell envelope. The enhanced lycopene production and secretion mediated by improved membrane permeability established a cell lysis-free system for an efficient releasing rate and downstream processing, demonstrating the importance of vesicle-associated membrane permeability in efficient lycopene production.

Preliminary study on the short-term changes of pulmonary perfusion after a single balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension.

BACKGROUND: Little is known about immediate responses of blood perfusion to the balloon pulmonary angioplasty (BPA) procedure. OBJECTIVES: To investigate the changes in pulmonary perfusion of balloon-dilated vessels and untreated vessels with before, immediately after a single BPA and at follow-up. DESIGN: Retrospective single-center cohort study. METHODS: Patients who had chronic thromboembolic pulmonary hypertension (CTEPH) and completed the pulmonary perfusion single photon emission computed tomography (SPECT) imaging before, immediately after BPA and at follow-up were included. We evaluated the perfusion defects of both-lung, BPA target (balloon dilated) and non-target (untreated) vessel segments according to Begic 3-point scale in each lung segment. RESULTS: Forty patients (40 BPA procedures) were included and were given next BPA after 89 (62-125) days. The hemodynamic parameters including mPAP, PVR, and RAP were significantly improved after a single BPA. Visual scoring results of pulmonary perfusion imaging in 40 BPAs showed the perfusion defect scores of target vessels reduced from 5.6 ± 2.6 to 4.2 ± 2.2 (p < 0.001) immediately after BPA, and then further diminished to 3.1 ± 1.9 (p < 0.001) at follow-up. While in the non-target vessels, the post-BPA perfusion defect scores did not change significantly (13.4 ± 4.7 versus 12.8 ± 4.6, p = 0.182), but tended to decrease at follow-up (12.2 ± 4.2). However, there were 17 BPAs of which the post-BPA perfusion defect scores of non-target vessels increased significantly (p < 0.001), but decreased at follow-up. CONCLUSION: In addition to improving the blood perfusion of target vessels, BPA also has a certain effect on the perfusion of some non-target vessels.