19 research outputs found
A time-resolved fluorescence microsphere-lateral flow immunochromatographic strip for quantitative detection of Pregnanediol-3-glucuronide in urine samples
Introduction: Pregnanediol-3-glucuronide (PdG), as the main metabolite of progesterone in urine, plays a significant role in the prediction of ovulation, threatened abortion, and menstrual cycle maintenance.Methods: To achieve a rapid and sensitive assay, we have designed a competitive model-based time-resolved fluorescence microsphere-lateral flow immunochromatography (TRFM-LFIA) strip.Results: The optimized TRFM-LFIA strip exhibited a wonderful response to PdG over the range of 30–2,000 ng/mL, the corresponding limit of detection (LOD) was calculated as low as 8.39 ng/mL. More importantly, the TRFM-LFIA strip was innovatively used for the quantitative detection of PdG in urine sample, and excellent recovery results were also obtained, ranging from 97.39% to 112.64%.Discussion: The TRFMLFIA strip possessed robust sensitivity and selectivity in the determination of PdG, indicating the great potential of being powerful tools in the biomedical and diagnosis region
Existence and Stability of Solutions for Implicit Multivalued Vector Equilibrium Problems
<p/> <p>A class of implicit multivalued vector equilibrium problems is studied. By using the generalized Fan-Browder fixed point theorem, some existence results of solutions for the implicit multivalued vector equilibrium problems are obtained under some suitable assumptions. Moreover, a stability result of solutions for the implicit multivalued vector equilibrium problems is derived. These results extend and unify some recent results for implicit vector equilibrium problems, multivalued vector variational inequality problems, and vector variational inequality problems.</p
Two Virus-like Particles that Cause Lytic Infections in Freshwater Cyanobacteria
Dear Editor, We report the results of the preliminary isolation of two virus-like particles (VLPs) that are infectious to freshwater cyanobacteria from Lake Donghu, the largest urban lake in China, located in Wuhan City, Hubei Province. By light and transmission electron microscopy, we observed VLPs causing lytic infections in freshwater bloom-forming cyanobacteria, and we detected their infections by exposing the VLPs to 12 cyanobacterial strains, including Microcystis aeruginosa HAB 1801 and Anabaena spiroides HAB 1211
Two Virus-like Particles that Cause Lytic Infections in Freshwater Cyanobacteria
Dear Editor, We report the results of the preliminary isolation of two virus-like particles (VLPs) that are infectious to freshwater cyanobacteria from Lake Donghu, the largest urban lake in China, located in Wuhan City, Hubei Province. By light and transmission electron microscopy, we observed VLPs causing lytic infections in freshwater bloom-forming cyanobacteria, and we detected their infections by exposing the VLPs to 12 cyanobacterial strains, including Microcystis aeruginosa HAB 1801 and Anabaena spiroides HAB 1211
Two Virus-like Particles that Cause Lytic Infections in Freshwater Cyanobacteria
Dear Editor, We report the results of the preliminary isolation of two virus-like particles (VLPs) that are infectious to freshwater cyanobacteria from Lake Donghu, the largest urban lake in China, located in Wuhan City, Hubei Province. By light and transmission electron microscopy, we observed VLPs causing lytic infections in freshwater bloom-forming cyanobacteria, and we detected their infections by exposing the VLPs to 12 cyanobacterial strains, including Microcystis aeruginosa HAB 1801 and Anabaena spiroides HAB 1211
Cultivation and Characterization of the MaMV-DC Cyanophage that Infects Bloom-forming Cyanobacterium Microcystis aeruginosa
The MaMV-DC cyanophage, which infects the bloom-forming cyanobacterium Microcystis aeruginosa, was isolated from Lake Dianchi, Kunming, China. Twenty-one cyanobacterial strains were used to detect the host range of MaMV-DC. Microcystic aeruginosa FACHB-524 and plaque purification were used to isolate individual cyanophages, and culturing MaMV-DC with cyanobacteria allowed us to prepare purified cyanophages for further analysis. Electron microscopy demonstrated that the negatively stained viral particles are tadpole-shaped with an icosahedral head approximately 70 nm in diameter and a contractile tail approximately 160 nm in length. Using one-step growth experiments, the latent period and burst size of MaMV-DC were estimated to be 2448 hours and approximately 80 infectious units per cell, respectively. Restriction endonuclease digestion and agarose gel electrophoresis were performed using purified MaMV-DC genomic DNA, and the genome size was estimated to be approximately 160 kb. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed four major structural proteins. These results support the growing interest in using freshwater cyanophages to control bloom-forming cyanobacterium
Six bufadienolides derivatives are the main active substance against human colorectal cancer HCT116 cells of Huachansu injection
Background: Huachansu injection (HCS) is an aqueous extract preparation of Traditional Chinese Medicine (TCM) toad skin (Bufo melanosticus or B. bufo gargarizans). As a national second-class and self-developed TCM preparation, it is widely used to treat human colorectal cancer (CRC), yet its substantial toxic side effects, such as vascular irritation reaction, drug fever, and allergic reactions, pose a considerable challenge during clinical use. In-depth research on the material basis of HCS' traditional efficacy is essential for developing more effective and less toxic medicine. Identifying the main components responsible for the efficacy of HCS is crucial in determining its material basis and explaining any adverse reactions. Purpose: The purpose of this study is to clarify the main active components of HCS as a growth inhibitory agent against CRC HCT116 cells and to further understand the material basis of its anti-CRC properties. Methods: Sulforhodamine B (SRB) assay was used to screen the compound with strong inhibitory activity against HCT116 cells from 44 compounds isolated from aqueous extracts of toad skin (B. melanosticus). The screened compounds as standard and MeOH extracts from HCS were determined by HPLC coupled with triple quadrupole mass spectrometry. The partial MeOH extract was subjected to HPLC system using solvents in a gradient of increasing polarity, yielding 12 fractions in total (HCS1 to HCS12). Besides, the screened active compounds were knocked out from HCS to obtain a fraction as a negative control, and the knocked-out components were collected as one fraction using semi-preparative HPLC. Those fractions were submitted to HPLC-MS/MS or HPLC-DAD system to determine the presence or absence of the screened compounds. In addition, cytotoxicity of those prepared fractions against CRC HCT116 cells was evaluated to determine the effect of the screened compounds in the anti-CRC of HCS. Results: Six compounds, namely arenobufagin, telocinobufagin, gamabufalin, hellebrigenin, 19-hydroxylbufagin and argentinogenin, were screened for their inhibitory activity (with an IC50 value of less than 400 nM), and were present in HCS at a total-mass-percentage of 1.35×10−3 % in HCS MeOH extract. In addition, those 6 compounds were mainly distributed in HCS8, which also showed the strongest inhibitory activity against HCT116 cells. And the results of multicomponent knockout assay indicated the negative control lost its anti-CRC activity significantly, while the activity can be restored after those 6 compounds were added to the negative control. Conclusions: Those six bufadienolides derivatives are responsible for the anti-CRC HCT116 cells activity of HCS, and are the main components of HCS on anti-CRC. Through this research, we can more clearly understand the main anti-CRC active components in HCS, and the work also lays the foundation for the development of more effective and less toxic medicine from HCS
Enhancer Analysis Unveils Genetic Interactions between TLX and SOX2 in Neural Stem Cells and In Vivo Reprogramming
The orphan nuclear receptor TLX is a master regulator of postnatal neural stem cell (NSC) self-renewal and neurogenesis; however, it remains unclear how TLX expression is precisely regulated in these tissue-specific stem cells. Here, we show that a highly conserved cis-element within the Tlx locus functions to drive gene expression in NSCs. We demonstrate that the transcription factors SOX2 and MYT1 specifically interact with this genomic element to directly regulate Tlx enhancer activity in vivo. Knockdown experiments further reveal that SOX2 dominantly controls endogenous expression of TLX, whereas MYT1 only plays a modulatory role. Importantly, TLX is essential for SOX2-mediated in vivo reprogramming of astrocytes and itself is also sufficient to induce neurogenesis in the adult striatum. Together, these findings unveil functional genetic interactions among transcription factors that are critical to NSCs and in vivo cell reprogramming
Dioscin integrates regulation of monosaturated fatty acid metabolism to extend the life span through XBP-1/SBP-1 dependent manner
Summary: Delay aging, especially in healthy life extension, brought the most interest to the medical field. Searching for anti-aging drugs with relative safety profiles bring natural products in hotspot. In this study, we find that dioscin promotes the health span extension in wild-type Caenorhabditis elegans. Through the genetic screening in C. elegans, we further reveal that dioscin activates the transcription factor SBP-1/SREBP by the UPRER transcription factor XBP-1 to upregulate transcription of the Δ9 desaturase FAT-5 and FAT-7, resulting in increased monounsaturated fatty acid content which requires for healthy life span extension. Intriguingly, through tissue-specific knockdown, we find that dioscin modulates the health span by activating SBP-1 in the intestine. Unexpectedly, dietary supplementation of POA and OA rescues XBP-1, SBP-1 mutants-induced shortened life span phenotype. Considering the conservation of MUFAs metabolism, dioscin may promote health span in other species, including mammals. Our work suggests that dioscin might be a promising candidate for developing anti-aging agent