Search

Docosahexaenoic acid (DHA) is an n-3 polyunsaturated fatty acid that is essential for human nutrition. Currently, DHA is commonly produced using Aurantiochytrium, and omics technologies are widely used to investigate the mechanism underlying high DHA production in Aurantiochytrium, providing a foundation for genetic modification of Aurantiochytrium and control of the fermentation process. In this article, the history and major research directions of DHA production by Aurantiochytrium are summarized, and the application of omics technology in Aurantiochytrium is reviewed. It also summarizes recent progress in the application of genomics, transcriptomics, proteomics, metabolomics and multi-omics approaches as well as mathematical models based on omics data to reveal the mechanism underlying high DHA production in Aurantiochytrium. This review concludes with a discussion of future prospects for the development and application of omics technology.

A new two-dimensional modeling approach combining the cellular automaton(CA) and the lattice Boltzmann model(LBM) was developed to simulate heat transport, fluid flow, solute diffusion, and dendritic growth in the process of the Al-4.7%Cu solidification of the single-phase solid solution alloy. And the changes of dendritic morphology and constituent under convection were analyzed. The present model improved the solutal distribution approach at the solid-liquid (S/L) interface, which made the change of solute more consistent with the actual transport. The simulation results demonstrate that dendritic morphology is strongly influenced by forced convection, comparing with that without accounting for convection. Under the forced convection, the dendrite grain sizes tend to be similar; the constituent in the interdendritic region is more homogeneous; and the composition in the whole solidification region exhibits a certain gradient trend from upstream to downstream.

Objective: To determine the expression level of Sonic hedgehog (Shh) in the passage of hair follicle stem cells (HFSCs), analyze the effect of Shh overexpression on the proliferation activity of HFSCs, and explore the survival of HFSCs after Shh overexpression and its effect on hair follicle regeneration., Methods: Hair follicles from the normal area (H1 group) and alopecia area (H2 group) of the scalp donated by 20 female alopecia patients aged 40-50 years old were taken, and the middle part of the hair follicle was cut under the microscope to culture, and the primary HFSCs were obtained and passaged; the positive markers (CD29, CD71) and negative marker (CD34) on the surface of the fourth generation HFSCs were identified by flow cytometry. The two groups of HFSCs were transfected with Shh-overexpressed lentivirus. Flow cytometry and cell counting kit 8 assay were used to detect the cell cycle changes and cell proliferation of HFSCs before and after transfection, respectively. Then the HFSCs transfected with Shh lentivirus were transplanted subcutaneously into the back of nude mice as the experimental group, and the same amount of saline was injected as the control group. At 5 weeks after cell transplantation, the expression of Shh protein in the back skin tissue of nude mice was detected by Western blot. HE staining and immunofluorescence staining were used to compare the number of hair follicles and the survival of HFSCs between groups., Results: The isolated and cultured cells were fusiform and firmly attached to the wall; flow cytometry showed that CD29 and CD71 were highly expressed on the surface of the cells, while CD34 was lowly expressed, suggesting that the cultured cells were HFSCs. The results of real-time fluorescence quantitative PCR and Western blot showed that the expression levels of Shh protein and gene in the 4th, 7th, and 10th passages of cells in H1 and H2 groups decreased gradually with the prolongation of culture time in vitro . After overexpression of Shh, the proliferation activity of HFSCs in the two groups was significantly higher than that in the blank group (not transfected with lentivirus) and the negative control group (transfected with negative control lentivirus), and the proliferation activity of HFSCs in H1 group was significantly higher than that in H2 group before and after transfection, showing significant differences ( P <0.05). At 5 weeks after cell transplantation, Shh protein was stably expressed in the dorsal skin of each experimental group; the number of hair follicles and the expression levels of HFSCs markers (CD71, cytokeratin 15) in each experimental group were significantly higher than those in the control group, and the number of hair follicles and the expression levels of HFSCs markers in H1 group were significantly higher than those in H2 group, and the differences were significant ( P <0.05)., Conclusion: Lentivirus-mediated Shh can be successfully transfected into HFSCs, the proliferation activity of HFSCs significantly increase after overexpression of Shh, which can secrete and express Shh continuously and stably, and promote hair follicle regeneration by combining the advantages of stem cells and Shh.

Objective: To evaluate if selenium yeast could inhibit the rat lung injury induced by ambient fine particulate matter( PM&#95;(2. 5) )., Methods: Fifty-six male SpragueDawley rats were randomly allocated in seven groups( n = 8 each). Saline control group, the rats were exposed to 0. 9% saline by instillation. PM&#95;(2. 5) exposure group, rats were exposed to PM&#95;(2. 5) by intra-tracheal instillation every other day for three times with the accumulated dose of 40 mg/kg. Selenium yeast treatment groups, three groups of rat were exposed to PM&#95;(2. 5) . Then the rats were given low, middle and high dose of selenium yeast, and the doses were 8. 75, 17. 5 and 35 mg/kg, respectively. High dose selenium yeast control group, rats were given high dose of selenium yeast only. Solvent control group, therats were given 1% carboxymethyl cellulose. Saline and PM&#95;(2. 5) were given in the first week. In the second week, selenium yeast and solvent were given by gavage. The rats were sacrificed 24 hours after the last gavage. The bronchoalveolar lavage fluid( BALF)was collected to count the neutrophils numbers and analyze the markers related to inflammation, oxidative stress and cell damage. The lung lobe that was not been lavaged was processed for light microscopic examination., Results: The proportions of neutrophils in BALF and the pathologic scores of lung in PM&#95;(2. 5) - exposed groups were significantly higher than control( P < 0. 05). Selenium yeast treatment caused decrease in tumor necrosis factor-α( TNF-α), interleukin-1β( IL-1β), lactate dehydrogenase( LDH), total protein( TP), alkaline phosphatase( AKP) and malondialdehyde( MDA) compared with the only PM&#95;(2. 5) exposure group. Meanwhile, the dose-dependent increase in totalsuperoxide dismutase( T-SOD) and glutathione peroxidase( GSH-Px) activities were observed. There were no significant differences among the groups of saline control group, high dose selenium yeast control group and solvent control group., Conclusion: Selenium yeast treatment may protect against acute injury induced by PM&#95;(2. 5) in rat lung.

Objective: To investigate the expression of the Toll-like receptor-4 (TLR-4) in temporo-mandibular joint synovitis in rats, and to discuss the correlation between the expression of TLR-4 and the synovitis., Methods: Sixty male wistar rats were randomly divided into five groups, 12 each. Group A was the control group in which the rats were given normal diet.In Group B, the rats' bilateral masseter muscles were cut off (masseter resection group). In Group C, An cast metal crown were bonded on the mandibular right first molar of each rat (occlusal interference group). In Group D, occlusal pad were bonded on maxillary molars of each rat (occlusal dimension increase group). In Group E, rats' bilateral masseter muscles were re-sected and occlusal pads were bonded on their maxillary molars (masseter resection and occlusal dimension increase group). Pathological changes of synovium were observed using hematoxylin and eosin (HE) stains and pathology scores were evaluated. The expression of TLR- 4 were determined by immunohistochemical stains, and the expression of TLR-4 mRNA were determined by real-time PCR. The correlation between the expression of TLR-4, TLR-4 mRNA and the pathological score were analyzed using Spearman analysis., Results: The pathological scores of Group A-E were 0.5 ± 0.5, 2.5 ± 1.0, 2.7 ± 1.0, 3.0 ± 0.9, 5.3 ± 1.2 respectively. The expression of TLR-4 were (3.2 ± 1.5)%, (16.± 2.6)%, (15.8 ± 2.1)%, (17.5 ± 2.4)%, (38.2 ± 4.4) %. The expression of TLR-4 mRNA were 1.07 ± 0.09, 2.12 ± 0.33, 2.07 ± 0.29, 2.17 ± 0.34, 4.53 ± 0.46. Compared with group A, groups B- E showed significant higher pathology score (P < 0.05) and increased expression of both TLR-4 (P < 0.05) and TLR-4 mRNA (P < 0.05). An significant positive correlation was found between the expression of TLR- 4 and the pathology score (r = 0.785, P < 0.05), and between the expression of TLR- 4 mRNA and the pathology score (r = 0.720, P < 0.05)., Conclusions: TLR-4 may be closely associated with the development of the synovitis of TMJ of rats.

Objective: To investigate the changes of peroxisome proliferator- activated receptor-γ coactivator -1α (PGC-1α) mRNA and cytoapoptosis in the rats' masseter muscle which had been influenced by unilateral chewing, and to explore the theoretical foundation of changes in masticatory muscles induced by unilateral chewing., Methods: The animal models were established by extracting the Wistar rats' left maxillary molars. Thirty- six female Wistar rats were randomly divided into four groups of 2, 4, 6 and 8 weeks, nine each. In each group there were six rats with molar extracted and three as control. The Ca²⁺ level was detected by atomic spectrophotometric method. The relative expression of PGC-1α mRNA was detected by real- time fluorescent quantitative PCR. The apoptosis index was detected by Hoechst staining., Results: The Ca²⁺ level in the muscle on the extraction side were significantly higher than that in the controls in the beginning stage of unilateral chewing, and reached the peak at the 4th week [(43.62 ± 2.36) µg/g]. The relative expressions of PGC-1α increased from the beginning and reached the maximum level at the 4th week [extraction side: (1.57 ± 0.10); non-extraction side: (1.92 ± 0.06)], while the relative expressions of PGC-1α in 6 and 8 weeks decreased gradually [extraction side: (1.06 ± 0.08), (1.08 ± 0.07); non- extraction side: (1.09 ± 0.10), (1.11 ± 0.08)]. The changes of apoptosis index on non- extraction side increased continually and peaked at the 6th week [(38.56 ± 1.64)%]., Conclusions: PGC-1α and cytoapoptosis played important roles in different stages of tissue remodeling induced by unilateral chewing.

A high performance liquid chromatographic method coupled with fluorometric detection has been developed for the determination of atracurium and its major metabolite laudanosine in dog plasma. The separation of atracurium and laudanosine was performed on an Agilent Eclipse Plus C18 column, and the mobile phase consisted of 0.03 mol/L dipotassium hydrogen phosphate and acetonitrile (72: 28, v/v) at a flow rate of 1.0 mL/min. Verapamil was used as the internal standard. The sample was extracted by dichloromethane, concentrated and dissolved in the mobile phase. The detection is performed at 240 nm for excitation and 320 nm for emission. The results showed that the linear concentration ranges of the calibration curve were 25 - 5 000 microg/L for atracurium (r = 0.999 0), and 25 - 6 000 microg/L for laudanosine (r = 0.9984). The recoveries were 92.1% - 109.5%. The limits of detection were 3 microg/L for atracurium and 1 microg/L for laudanosine. The RSDs of intra-day and inter-day were less than 10%. The stability tests under various conditions have been performed. The method is specific, sensitive and accurate in the determination of atracurium and laudanosine, and also can be used for the pharmacokinetic investigations of atracurium and laudanosine in plasma.

A method for the simultaneous determination of prilocaine and lidocaine in vitro percutaneous absorption liquid using gas chromatography-mass spectrometry (GC-MS) has been developed. Ropivacaine served as the internal standard. The sample was alkalified with sodium hydroxide and a single-step liquid-liquid extraction with ethyl acetate. Selected ion monitoring (SIM) method was applied for the detection. Using the method to determine prilocaine and lidocaine in the rapid transdermal study. Prilocaine and lidocaine have good linear relationships in the concentration of 0.016 - 50.0 mg/L. The recoveries of prilocaine and lidocaine ranged from 85.3% to 109.7%, and the relative standard deviations of intra-day and inter-day were less than 10%. The limits of detection were 3 microg/L for prilocaine and 2 microg/L for lidocaine. This assay was time-saving, alternative and sensitive. It was suitable for the analysis of samples collected from the study on in vitro percutaneous absorption.