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81.
A combination of immunomagnetic separation (IMS) and polymerase chain reaction (PCR) was used to detect Alicyclobacillus acidoterrestris (A. acidoterrestris) in apple juice. The optimum technological parameters of the IMS system were investigated. The results indicated that the immunocapture reactions could be finished in 60 min and the quantity of IMPs used for IMS was 2.5 mg/mL. Then the combined IMS-PCR procedure was assessed by detecting A. acidoterrestris in apple juice samples. The agarose gel electrophoresis results of 20 different strains showed that the IMS-PCR procedure presented high specificity to the A. acidoterrestris. The sensitivity of the IMS-PCR was 2×101 CFU/mL and the total detection time was 3 to 4 h. Of the 78 naturally contaminated apple juice samples examined, the sensitivity, specificity and accuracy of IMS-PCR compared with the standardized pour plate method were 90.9%, 97.0% and 96.2%, respectively. The results exhibited that the developed IMS-PCR method will be a valuable tool for detecting A. acidoterrestris and improving food quality in juice samples. 相似文献
82.
Yuan Han Rui Chen Qicheng Lin Yu Liu Wenwei Ge Hong Cao Jun Li 《Journal of cellular and molecular medicine》2021,25(18):8947-8956
Amyloid-β (Aβ) deposition in the brain has been implicated in the development of Alzheimer's disease (AD), and neuroinflammation generates AD progression. Therapeutic effects of anti-inflammatory approaches in AD are still under investigation. Curcumin, a potent anti-inflammatory and antioxidant, has demonstrated therapeutic potential in AD models. However, curcumin's anti-inflammatory molecular mechanisms and its associated cognitive impairment mechanisms in AD remain unclear. The high-mobility group box-1 protein (HMGB1) participates in the regulation of neuroinflammation. Herein, we attempted to evaluate the anti-inflammatory effects of chronic oral administration of curcumin and HMGB1 expression in APP/PS1 transgenic mice AD model. We found that transgenic mice treated with a curcumin diet had shorter escape latencies and showed a significant increase in percent alternation, when compared with transgenic mice, in the Morris water maze and Y-maze tests. Additionally, curcumin treatment could effectively decrease HMGB1 protein expression, advanced glycosylation end product-specific receptor (RAGE), Toll-like receptors-4 (TLR4) and nuclear factor kappa B (NF-κB) in transgenic mice hippocampus. However, amyloid plaques detected with thioflavin-S staining in transgenic mice hippocampus were not affected by curcumin treatment. In contrast, curcumin significantly decreased GFAP-positive cells, as assessed by immunofluorescence staining. Taken together, these data indicate that oral administration of curcumin may be a promising agent to attenuate memory deterioration in AD mice, probably inhibiting the HMGB1-RAGE/TLR4-NF-κB inflammatory signalling pathway. 相似文献
83.
Melissa Carrillo Suraj Pandey Juan Sanchez Moraima Noda Ishwor Poudyal Luis Aldama Tek Narsingh Malla Elin Claesson Weixiao Yuan Wahlgren Denisse Feliz Vukica Šrajer Michał Maj Leticia Castillon So Iwata Eriko Nango Rie Tanaka Tomoyuki Tanaka Luo Fangjia Marius Schmidt 《Structure (London, England : 1993)》2021,29(7):743-754.e4
84.
Junfeng Dou Wei Qin Jing Yuan Aizhong Ding En Xie Yingying Wang 《Bioremediation Journal》2014,18(3):248-257
A pure strain of Microbacterium lacticum DJ-1 capable of anaer-obic biodegradation of ethylbenzene was isolated from soil contaminated with gasoline. Growth of the strain and biodegradation of ethylbenzene in batch cultures led to stoichiometric reduction of nitrate. M. lacticum DJ-1 could degrade 100 mg L?1 of ethylbenzene completely, with a maximum degradation rate of 15.02 ± 1.14 mg L?1 day?1. Increasing the initial concentration of ethy-lbenzene resulted in decreased degradative ability. The cell-specific growth rates on ethylbenzene conformed to the Haldane–Andrew model in the substrate level range of 10–150 mg L?1. Kinetic parameters were determined by nonlinear regression on specific growth rates and various initial substrate concentrat-ions, and the values of the maximum specific growth rate, half saturation constant, and inhibition constant were 0.71 day?1, 34.3 mg L?1, and 183.5 mg L?1, respectively. This is the first report of ethylbenzene biodegradation by a bacterium of Microbacterium lacticum under nitrate-reducing conditions. 相似文献
85.
Roy E. Jonas Ching Yuan Thomas G. Ebrey 《Preparative biochemistry & biotechnology》2013,43(3-4):279-288
Abstract The transducin heterotrimer and its α- and βγ-subunits have been purified from frozen bovine rod outer segments by modifying existing procedures. The methods described here are relatively simple and fast. The yield (ca. 8 mgs/100 retinas) and purity of the transducin heterotrimer and subunits from frozen retinas is equal to or larger than those previously obtained from fresh or frozen retinas. 相似文献
86.
87.
88.
Andreas Ritter Mourad Sanhaji Alexandra Friemel Susanne Roth Udo Rolle Frank Louwen Juping Yuan 《Cell cycle (Georgetown, Tex.)》2015,14(23):3755-3767
Mitotic centromere-associated kinesin (MCAK) is the best characterized member of the kinesin-13 family and plays important roles in microtubule dynamics during mitosis. Its activity and subcellular localization is tightly regulated by an orchestra of mitotic kinases, such as Aurora B. It is well known that serine 196 of MCAK is the major phosphorylation site of Aurora B in Xenopus leavis extracts and that this phosphorylation regulates its catalytic activity and subcellular localization. In the current study, we have addressed the conserved phosphorylation site serine 192 in human MCAK to characterize its function in more depth in human cancer cells. Our data confirm that S192 is the major phosphorylation site of Aurora B in human MCAK and that this phosphorylation has crucial roles in regulating its catalytic activity and localization at the kinetochore/centromere region in mitosis. Interfering with this phosphorylation leads to a delayed progression through prometa- and metaphase associated with mitotic defects in chromosome alignment and segregation. We show further that MCAK is involved in directional migration and invasion of tumor cells, and interestingly, interference with the S192 phosphorylation affects this capability of MCAK. These data provide the first molecular explanation for clinical observation, where an overexpression of MCAK was associated with lymphatic invasion and lymph node metastasis in gastric and colorectal cancer patients. 相似文献
89.
Tinoush Moulaei Olga Stuchlik Matthew Reed Weirong Yuan Jan Pohl Wuyuan Lu Lauren Haugh-Krumpe Barry R O'Keefe Alexander Wlodawer 《Protein science : a publication of the Protein Society》2010,19(9):1649-1661
The antiviral lectin scytovirin (SVN) contains a total of five disulfide bonds in two structurally similar domains. Previous reports provided contradictory results on the disulfide pairing in each individual domain, and we have now re‐examined the disulfide topology. N‐terminal sequencing and mass spectrometry were used to analyze proteolytic fragments of native SVN obtained at acidic pH, yielding the assignment as Cys7–Cys55, Cys20–Cys32, Cys26–Cys38, Cys68–Cys80, and Cys74–Cys86. We also analyzed the N‐terminal domain of SVN (SD1, residues 1–48) prepared by expression/oxidative folding of the recombinant protein and by chemical synthesis. The disulfide pairing in the chemically synthesized SD1 was forced into predetermined topologies: SD1A (Cys20–Cys26, Cys32–Cys38) or SD1B (Cys20–Cys32, Cys26–Cys38). The topology of native SVN was found to be in agreement with the SD1B and the one determined for the recombinant SD1 domain. Although the two synthetic forms of SD1 were distinct when subjected to chromatography, their antiviral properties were indistinguishable, having low nM activity against HIV. Tryptic fragments, the “cystine clusters” [Cys20–Cys32/Cys26–Cys38; SD1] and [Cys68–Cys80/Cys74–C‐86; SD2], were found to undergo rapid disulfide interchange at pH 8. This interchange resulted in accumulation of artifactual fragments in alkaline pH digests that are structurally unrelated to the original topology, providing a rational explanation for the differences between the topology reported herein and the one reported earlier (Bokesh et al., Biochemistry 2003;42:2578–2584). Our observations emphasize the fact that proteins such as SVN, with disulfide bonds in close proximity, require considerable precautions when being fragmented for the purpose of disulfide assignment. 相似文献
90.
The dengue fever epidemic in Guangzhou may have been affected by the Coronavirus Disease 2019 (COVID-19) pandemic. The number of dengue cases dropped drastically in 2020, and there have been only 2 local cases, suggesting that dengue has not become endemic in Guangzhou.Guangzhou is located on the southeast coast of China and is the country’s third largest city. Since 1978, outbreaks of dengue fever have occurred intermittently in this city. In the past decade, the number of reported dengue cases reached more than 1,000 in 2013, 2014, 2018, and 2019, with 37,385 cases reported in 2014 alone. Therefore, dengue fever is a major public health concern in Guangzhou, and there is a continuing argument that it is endemic in Guangzhou [1–3].The numbers of dengue cases from 2017 to 2020 are shown in Table 1. In 2020, the total and local case numbers dropped dramatically compared to the previous years. With a high proportion of imported cases (n = 32, 94.12%), the proportion of local cases (n = 2, 5.88%) was considerably low in 2020. All the prevention and control strategies for dengue, including issuing public education messages, preventing further mosquito bites in patients, cleaning vector breeding sites, and using pesticides, were similar during these years. Additionally, dengue, as a mosquito-borne viral infectious disease, is closely related to mosquito density. The mosquito ovitrap index (MOI), which is the proportion of positive mosquito ovitraps, is usually used to indicate mosquito density. The MOI in 2017, 2018, and 2019 was 7.073 ± 1.016, 9.657 ± 1.307, and 8.464 ± 0.961, respectively. The average MOI was 8.398 ± 0.648 from 2017 to 2019 in Guangzhou. The MOI in 2020 was 7.135 ± 0.786, which remained at the median risk level. Therefore, the abnormal decline in dengue cases could not be attributed to the change in mosquito density in 2020.Table 1Numbers and percentages of dengue cases from 2017 to 2019.
Open in a separate windowIn 2020, the 14-day quarantine in a designated hotel for international travelers to curb the spread of Coronavirus Disease 2019 (COVID-19) was an important public health intervention. People had to remain indoors except for medical care needs. All imported dengue cases were identified during their quarantine periods. No secondary case related to the imported cases was reported. This may be because Aedes albopictus, which is the major vector of dengue in Guangzhou, bites aggressively during the day outdoors. The chance of being bitten by A. albopictus was reduced by staying all day indoors. Moreover, some research revealed that viremia occurred 6 to 18 hours before symptoms appeared and lasted as long as 12 days [4]. After the 14-day quarantine, viremia had almost subsided. Therefore, imported dengue cases were unlikely to be transmitted. The impact of imported dengue cases was limited by the quarantine, which provided a rare opportunity to identify the local epidemic.The epidemiology investigation showed that the 2 local cases, who were living in the same building, had no travel history outside Guangzhou in 2020 and had symptoms successively. Two dengue virus serotype 2 (DENV-2) strains were isolated from them. The envelope gene sequences were obtained and deposited in GenBank under accession numbers and MW295818. Reference sequences, which were downloaded from GenBank, and sequences of Guangzhou strains identified in the previous years, were used to construct a phylogenetic tree. The 2 isolated strains in 2020 were identical. The tree ( MW345921Fig 1) shows that the 2 strains belonged to the Malaysia/Indian subcontinent genotype, which was the prevailing genotype in Guangzhou [5]. However, they were neither identical with nor derived from the Guangzhou strains obtained from the previous years. Using the Basic Local Alignment Search Tool in GenBank, the 2 strains were found to be highly similar to those identified in Zhejiang (China), Singapore, and Guangdong (China) in 2017. These results imply that the local cases may be secondary to some undiscovered cases imported from other cities in China, as no restriction and quarantine was imposed for domestic travels.Open in a separate windowFig 1Maximum-likelihood phylogenetic tree shows the evolutionary relationships of DENV-2 detected in the sera of 2 local cases along with 45 other sequences.The reference sequences are named using the GenBank accession number, country, and year. The sequences of strains isolated in Guangzhou are named using the GenBank accession number, year, and our lab number. Bootstrap support values are shown in the notes. Strains isolated in 2020 are indicated with a black triangle.When the impact of imported dengue cases was limited by quarantine, dengue did not spread in Guangzhou during 2020, with the MOI still at median risk level and without any changes in the prevention and control strategies. Moreover, serotype 1 had been prevalent in Guangzhou since 2011 [6,7]. However, there was no local infection of serotype 1 detected in 2020. These observations may provide further evidence that dengue fever is not endemic in Guangzhou.In conclusion, the number of dengue cases decreased during the COVID-19 epidemic in Guangzhou in 2020. Thus, we believe that dengue fever is not endemic in Guangzhou. 相似文献
Year | 2017 | 2018 | 2019 | 2020 |
Total cases | 944 | 1,295 | 1,655 | 34 |
Imported cases(percentage) | 69 (7.31%) | 96 (7.41%) | 270 (16.31%) | 32 (94.12%) |
Local cases (percentage) | 875 (92.69%) | 1,199 (92.59%) | 1,385 (83.69%) | 2 (5.88%) |