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Leptotrichia hongkongensis sp. nov., a novel Leptotrichia species with the oral cavity as its natural reservoir
Patrick C. Y. Woo, Samson S. Y. Wong, Jade L. L. Teng, Kit-Wah Leung, Antonio H. Y. Ngan, Dong-qing Zhao, Herman Tse, Susanna K. P. Lau, Kwok-Yung Yuen
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2010, 11(6): 391-401.
https://doi.org/10.1631/jzus.B1000056
A straight, non-sporulating, Gram-variable bacillus (HKU24T) was recovered from the blood culture of a patient with metastatic breast carcinoma. After repeated subculturing in BACTEC Plus Anaerobic/F blood culture broth, HKU24T grew on brucella agar as non-hemolytic, pinpoint colonies after 96 h of incubation at 37 °C in an anaerobic environment and aerobic environment with 5% CO2. Growth was enhanced with a streak of Staphylococcus aureus. HKU24T was non-motile and catalase-negative, but positive for alkaline phosphatase, β-glucosidase, and α-glucosidase. It hydrolyzed phenylphosphonate and reduced resazurin. 16S rRNA, groEL, gyrB, recA, and rpoB sequencing showed that HKU24T occupies a distinct phylogenetic position among the Leptotrichia species, being most closely related to Leptotrichia trevisanii. Using HKU24T groEL, gyrB, recA, and rpoB gene-specific primers, fragments of these genes were amplified from one of 20 oral specimens. Based on phenotypic and genotypic characteristics, we propose a new species, Leptotrichia hongkongensis sp. nov., to describe this bacterium.
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Wernicke encephalopathy following splenectomy in a patient with liver cirrhosis: a case report and review of the literature
Xia-ping Zhang, Yuan-qiang Lu, Wei-dong Huang
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2010, 11(6): 433-436.
https://doi.org/10.1631/jzus.B1000016
Objective: To report a case of Wernicke encephalopathy in the early stage after surgery. Methods: A nonalcoholic female patient with hepatitis B-related cirrhosis and hypersplenism underwent splenectomy in a local hospital. No surgical complications occurred and the patient recovered well. However, on the eighth postoperative day she developed psychiatric and neurological disturbance without an obvious cause. She was then admitted to our hospital. Brain magnetic resonance imaging (MRI) with FLAIR T2 showed symmetric high-signal intensities in the periaqueductal area of the midbrain, which were consistent with Wernicke encephalopathy. She was thus given intramuscular thiamine immediately. Results: After the administration of thiamine, the patient’s confused mental state resolved within 3 d, and her dystaxia gradually improved over the next 5 d. The brain MRI with FLAIR T2 was re-examined one month after the episode, and showed nearly complete resolution of the previously abnormal signal intensities in the periaqueductal area of the midbrain. Conclusion: Physicians should be aware of the possibility of acute Wernicke encephalopathy, especially in patients with liver dysfunction.
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Purification, chemical modification and immunostimulating activity of polysaccharides from Tremella aurantialba fruit bodies
Xiu-ju Du, Jing-song Zhang, Yan Yang, Qing-jiu Tang, Wei Jia, Ying-jie Pan
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2010, 11(6): 437-442.
https://doi.org/10.1631/jzus.B0900402
Ultrafiltration and a series of chromatographic steps were used to isolate and purify polysaccharides from Tremella aurantialba fruit bodies. Three crude fractions (TAP50w, TAP10–50w, and TAP1–10w), five semi-purified fractions (TAPA–TAPE), and one purified fraction (TAPA1) were obtained. A sulfated derivative of TAPA1 (TAPA1-s) was prepared by chemical modification. The immunostimulating activity of the polysaccharide fractions in vitro was determined using the mouse spleen lymphocyte proliferation assay. Of the three crude fractions tested, cell proliferation rates were increased most by TAP50w. Furthermore, TAPA1-s was markedly more stimulatory than TAPA1, indicating that sulfonation was an effective way to enhance the immunostimulating activity of polysaccharide.
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Responses of phospholipase D and lipoxygenase to mechanical wounding in postharvest cucumber fruits
Yu-ying Zhao, Chun-lu Qian, Ji-cheng Chen, Yan Peng, Lin-chun Mao
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2010, 11(6): 443-450.
https://doi.org/10.1631/jzus.B0900357
This study was to investigate the responses of phospholipase D (PLD) and lipoxygenase (LOX) to mechanical wounding in postharvest cucumber (Cucumis sativus L. cv. Biyu-2) fruits. Membrane-associated Ca2+ content, activities and gene expression of PLD and LOX, and contents of phosphatidylcholine (PC), phosphatidylinositol (PI), and phosphatidic acid (PA) were determined in cucumber fruits following mechanical wounding. Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding, while membrane-associated Ca2+ content decreased. Accompanying with the increase of PLD and LOX activities, accumulation of PA and losses of PC and PI were observed in all fruits, but there were differences of degrees between wounded and control fruits. Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury. The activation of PLD and LOX might be the result of gene expression, which could be stimulated by the Ca2+ flowing from the membrane to the cytoplasm upon receiving the wounding signals.
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Synergistic effects of tea polyphenols and ascorbic acid on human lung adenocarcinoma SPC-A-1 cells
Wei Li, Jian-xiang Wu, You-ying Tu
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2010, 11(6): 458-464.
https://doi.org/10.1631/jzus.B0900355
Tea polyphenols have been shown to have anticancer activity in many studies. In the present study, we investigated effects of theaflavin-3-3′-digallate (TF3), one of the major theaflavin monomers in black tea, in combination with ascorbic acid (AA), a reducing agent, and (−)-epigallocatechin-3-gallate (EGCG), the main polyphenol presented in green tea, in combination with AA on cellular viability and cell cycles of the human lung adenocarcinoma SPC-A-1 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay showed that the 50% inhibition concentrations (IC50) of TF3, EGCG, and AA on SPC-A-1 cells were 4.78, 4.90, and 30.62 μmol/L, respectively. The inhibitory rates of TF3 combined with AA (TF3+AA) and EGCG combined with AA (EGCG+AA) at a molar ratio of 1:6 on SPC-A-1 cells were 54.4% and 45.5%, respectively. Flow cytometry analysis showed that TF3+AA and EGCG+AA obviously increased the cell population in the G0/G1 phase of the SPC-A-1 cell cycle from 53.9% to 62.8% and 60.0%, respectively. TF3-treated cells exhibited 65.3% of the G0/G1 phase at the concentration of its IC50. Therefore, TF3+AA and EGCG+AA had synergistic inhibition effects on the proliferation of SPC-A-1 cells, and significantly held SPC-A-1 cells in G0/G1 phase. The results suggest that the combination of TF3 with AA or EGCG with AA enhances their anticancer activity.
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Detection of nitrogen-overfertilized rice plants with leaf positional difference in hyperspectral vegetation index
Qi-fa Zhou, Zhan-yu Liu, Jing-feng Huang
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2010, 11(6): 465-470.
https://doi.org/10.1631/jzus.B0900348
The main objective of this work was to compare the applicability of the single leaf (the uppermost leaf L1 and the third uppermost leaf L3) modified simple ratio (mSR705 index) and the leaf positional difference in the vegetation index between L1 and L3 (mSR705L1−mSR705L3) in detecting nitrogen (N)-overfertilized rice plants. A field experiment consisting of three rice genotypes and five N fertilization levels (0, 75, 180, 285, and 390 kg N/ha) was conducted at Xiaoshan, Hangzhou, Zhejiang Province, China in 2008. The hyperspectral reflectance (350–2500 nm) and the chlorophyll concentration (ChlC) of L1 and L3 were measured at different stages. The mSR705L1 and mSR705L3 indices appeared not to be highly sensitive to the N rates, especially when the N rate was high (above 180 kg N/ha). The mean mSR705L1−mSR705L3 across the genotypes increased significantly (P<0.05) or considerably from 180 to 285 kg N/ha treatment and from 285 to 390 kg N/ha treatment at all the stages. Also, use of the difference (mSR705L1−mSR705L3) greatly reduced the influence of the stages and genotypes in assessing the N status with reflectance data. The results of this study show that the N-overfertilized rice plants can be effectively detected with the leaf positional difference in the mSR705 index.
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11 articles
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