Please wait a minute...

Current Issue

, Volume 11 Issue 6 Previous Issue    Next Issue
Biomedicine
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
Abstract   PDF (0KB)
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.
Mathematical models of canine right and left atria cardiomyocytes
Ling Xia, Ying-lan Gong, Xiu-wei Zhu, Yu Zhang, Qi Sun, Heng-gui Zhang
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2010, 11(6): 402-416.   https://doi.org/10.1631/jzus.B0900346
Abstract   PDF (0KB)
The aim of this study is to build two mathematical models of canine ionic currents specific to right atria and left atria. The canine left atria mathematical model was firstly modified from the Ramirez-Nattel-Courtemanche (RNC) model using the recently available experimental data of ionic currents and was further developed based on our own experimental data. A model of right atria was then built by considering the differences between right atria and left atria. The two developed models well reproduced the experimental data on action potential morphology, the rate dependence, and action potential duration restitution. They are useful for investigating the mechanisms underlying the heterogeneity of canine regional action potentials and would help the simulation of whole heart excitation propagation and cardiac arrhythmia in the near future.
Multilayered polyelectrolyte-coated gold nanorods as multifunctional optical contrast agents for cancer cell imaging
Li-li Chen, Li Jiang, Ya-lun Wang, Jun Qian, Sailing He
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2010, 11(6): 417-422.   https://doi.org/10.1631/jzus.B0910731
Abstract   PDF (0KB)
We report the application of multilayered polyelectrolyte-coated gold nanorods (GNRs) as multifunctional optical contrast agents for cancer cell imaging. The surface modification of GNRs improves their chemical stability and facilitates them to be taken up by cancer cells through electrostatic interaction. The unique longitudinal surface plasmon resonance property of GNRs makes them suitable as both “scattering contrast agents” and “Raman contrast agents”. In our experiments, the staining of GNRs in cells was further confirmed by dark field microscopy and Raman microscopy. Our experiment results indicated that GNRs have great potential as multifunctional “optical contrast agents” for future in vivo animal imaging.
Is alcohol consumption associated with gastroesophageal reflux disease?
Shao-hua Chen, Jie-wei Wang, You-ming Li
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2010, 11(6): 423-428.   https://doi.org/10.1631/jzus.B1000013
Abstract   PDF (0KB)
Gastroesophageal reflux disease (GERD) is one of the most common disorders with an increasing incidence and prevalence. Alcohol consumption may be a risk factor for GERD; however, the relationship remains to be fully elucidated. The results of different studies are diverse and contradictory. Systematic investigations concerning this matter are inappropriate and further well-designed prospective studies are needed to clarify the effect of alcohol on GERD.
Congenital spinal intradural arachnoid cyst associated with intrathoracic meningocele in a child
Zheng-xi Rao, Jin Li, Si-qing Hang, Chao You
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2010, 11(6): 429-432.   https://doi.org/10.1631/jzus.B0900375
Abstract   PDF (0KB)
Congenital spinal intradural arachnoid cyst associated with intrathoracic meningocele is very rare. We report a case in a 9-year-old Chinese boy who presented with a two-week history of progressive paraparesis and gait ataxia. Magnetic resonance imaging revealed that a dorsal intradural extramedullary cystic lesion extended from T1 to T5 and compressed the spinal cord. A left lateral intrathoracic meningocele pouch was found incidentally at the level of T1. The arachnoid cyst as well as meningocele was removed and the spinal cord compression was relieved. Arachnoid cyst was confirmed by histological examination. The patient recovered well postoperatively. This is the second report of such a case in the world according to the available literature. The take-home message for our case is that the surgical approach should be individualized, depending on the size and location.
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
Abstract   PDF (0KB)
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.
Biotechnology
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
Abstract   PDF (0KB)
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.
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
Abstract   PDF (0KB)
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.
Mechanism of action of two insect toxins huwentoxin-III and hainantoxin-VI on voltage-gated sodium channels
Rui-lan Wang, Su Yi, Song-ping Liang
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2010, 11(6): 451-457.   https://doi.org/10.1631/jzus.B0900393
Abstract   PDF (0KB)
Selenocosmia huwena and Selenocosmia hainana are two tarantula species found in southern China. Their venoms contain abundant peptide toxins. Two new neurotoxic peptides, huwentoxin-III (HWTX-III) and hainantoxin-VI (HNTX-VI), were obtained from the venom using ion-exchange chromatography and reverse-phase high performance liquid chromatography (RP-HPLC). The mechanism of action of HWTX-III and HNTX-VI on insect neuronal voltage-gated sodium channels (VGSCs) was studied via whole-cell patch clamp techniques. In a fashion similar to δ-atracotoxins, HNTX-VI can induce a slowdown of current inactivation of the VGSC and reduction in the peak of Na+ current in cockroach dorsal unpaired median (DUM) neurons. Meanwhile, 10 µmol/L HNTX-IV caused a positive shift of steady-state inactivation of sodium channel. HWTX-III inhibited VGSCs on DUM neurons (concentration of toxin at half-maximal inhibition (IC50)≈1.106 µmol/L) in a way much similar to tetrodotoxin (TTX). HWTX-III had no effect on the kinetics of activation and inactivation. The shift in the steady-state inactivation curve was distinct from other depressant spider toxins. The diverse effect and the mechanism of action of the two insect toxins illustrate the diverse biological activities of spider toxins and provide a fresh theoretical foundation to design and develop novel insecticides.
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
Abstract   PDF (0KB)
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.
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
Abstract   PDF (0KB)
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.
11 articles

NoticeMore

Links