Development of a rapid immunochromatographic strip test for the detection of Vibrio parahaemolyticus toxin B that cause acute hepatopancreatic necrosis disease

Here, two monoclonal antibodies (MAbs) specific to different epitopes on ToxB, a toxin produced by Vibrio parahaemolyticus that causes acute hepatopancreatic necrosis disease (VP_AHPND), were employed to develop a rapid strip test. One MAb was conjugated to colloidal gold to bind to ToxB at the application pad, and another MAb was used to capture colloidal gold MAb–protein complexes at the test line (T) on the nitrocellulose strip. To validate test performance, a downstream control line (C) of goat anti-mouse immunoglobulin G antibody was used to capture the free colloidal gold conjugate MAb. The sample in the application buffer could be applied directly to the application well, and the test result was obtained within 15 min. The sensitivity of the kit is approximately 6.25 µg/ml of toxin, which was equivalent to the toxin produced by approximately 10⁷ cfu/ml of bacteria. This kit is convenient and easy to use since it can be used to identify VP_AHPND directly using a single colony of bacteria grown on agar culture plates. Because of its high specificity and simplicity, as well as not being reliant on sophisticated equipment or specialized skills, this strip test could be used by farmers for surveillance for ToxB-producing bacteria.     

Production of acute hepatopancreatic necrosis disease toxin is affected by addition of cell‐free supernatant prepared from AI‐2‐producing Vibrio harveyi mutant

Acute hepatopancreatic necrosis disease (AHPND) causes massive mortality in shrimp ponds within the first month poststocking. The causative agent is a specific strain of Vibrio parahaemolyticus (VP_AHPND) that has acquired the capability to produce virulent binary toxins called ToxA and ToxB. This study aims to test the effect of the addition of an autoinducer‐2‐containing cell‐free supernatant (CFS) from the mutant Vibrio harveyi (VH) on growth and toxin production of VP_AHPND. The relative AI‐2‐like activity in CFS was detected by luminescence assay. The effect of CFS (5 and 9%) on growth and toxin production of VP_AHPND was evaluated. Compared to the control culture (without CFS‐VH addition), the addition of either 5 or 9% CFS‐VH affected the growth at the initial stage of VP_AHPND. Similar growth profiles of VP_AHPND were found with the addition of CFS‐VH at both concentrations. Western blot analysis suggests that the addition of CFS‐VH affected the production of both toxins. ToxA could be detected at the early hour post‐CFS‐VH inoculation, whereas the high amount of ToxB was detected when 5% CFS‐VH was added. However, interfering with the AI‐2 function with furanone, the AI‐2 antagonist resulted in a slight delay in the production of both toxins. Results from this study will help to design a novel strategy to control AHPND in shrimp culture.     

Effect of AMPKα2 gene silencing by shRNA recombinant plasmid on chloride-mediated anoxia/reoxygenation injury in rat cardiomyocytes

AIM: To explore the role of AMP-activated protein kinase α2 subunit (AMPKα2) gene in chloride-mediated anoxia/reoxygenation (A/R) injury by transfection of short-hairpin RNA (shRNA) expression vector targeting to AMPKα2 gene into H9c2 cardiomyocytes. METHODS: Recombinant shRNA expression vector pSuper-AMPKα2 targeting to AMPKα2 gene was constructed and transfected into H9c2 cardiomyocytes. The protein expression of AMPKα2 was determined by Western blotting. The cells were divided into 5 groups: control group, A/R group, Cl^--free A/R group, pSuper+Cl^--free A/R group and pSuper-AMPKα2 shRNA+Cl^--free A/R group. After treatment, the cell viability was detected by MTT assay. LDH activity was analyzed with an automatic biochemical analyzer. The apoptotic rate and the level of intracellular ROS was measured by flow cytometry. The activity of SOD and GSH-Px was analyzed by a colorimetric method. RESULTS: The result of sequencing proved that the recombinant plasmid pSuper-AMPKα2 shRNA was correctly constructed. The protein level of AMPKα2 significantly decreased after the plasmid was transfected into the cardiomyocytes. Compared with A/R group, the cell viability and the activity of SOD and GSH-Px were significantly increased, while the activity of LDH, apoptotic rate and ROS production were significantly decreased in Cl^--free A/R group. The protective effect of Cl^--free solution on the A/R-induced injury of cardiomyocytes was abolished, and the ROS production was increased and the activity of SOD and GSH-Px was decreased after the cells were transfected with pSuper-AMPKα2 shRNA. CONCLUSION: Recombinant plasmid pSuper-AMPKα2 shRNA is successfully constructed, and silencing of AMPKα2 gene abolishes the protective effect of Cl^--free solution on A/R injury.     

种植模式和氮肥形态对威芋3号马铃薯产量及品质的影响

试验选用马铃薯品种威芋3号,采用田间试验方法,研究了薯玉传统间作模式、薯豆间作新模式下氮素形态对马铃薯产量、品质、营养吸收的影响。结果表明:薯豆间作显著提高马铃薯产量,比单作和薯玉间作分别增产17.2%、5.8%,并显著提高薯块粗蛋白含量和单株氮、钾含量,但使淀粉含量降低。与硝态氮肥相比较,铵态氮肥、酰胺态氮肥显著提高马铃薯产量,分别增产15.73%、13.49%;与其他两种形态氮肥相比,铵态氮肥显著提高了薯块的粗蛋白、Vc含量、植株氮、磷、钾含量,但显著降低了还原糖、淀粉含量。氮肥形态与间作对马铃薯粗蛋白、淀粉、还原糖、产量、单株氮、钾含量有显著的交互效应。     

MicroRNA expression in hepatocytes with hydrogen peroxide-induced oxidative stress-injury and alleviating effect of mesenchymal stem cell-conditioned medium

AIM: To evaluate the changes of microRNA (miRNA) in hepatocytes during hydrogen peroxide-induced oxidative stress injury, and to observe the alleviating effect of mesenchymal stem cell-conditioned medium (MSC-CM) in this progress. METHODS: The hepatocyte oxidative stress injury model was established using hydrogen peroxide and human normal liver cell line L02. MSC-CM was prepared using centrifugation and filter. The effects of MSC-CM on hepatocyte injury were evaluated by apoptosis analysis, cell viability detection, cell cycle, and mitochondrial membrane potential (MMP). Twenty-one differentially expressed miRNAs were selected by gene chip hybridization, in which miR-143, miR-145, miR-301a and let-7a were confirmed by RT-qPCR. Bioinformatics software was utilized to predict target proteins of these miRNAs, and then the proteins were verified by Western blot.RESULTS: MSC-CM markedly attenuated hydrogen peroxide-induced oxidative stress injury by reducing apoptosis, promoting cell viability and regulating cell cycle. The expression of miR-143, miR-145, miR-301a and let-7a, indentified by RT-qPCR, increased under the condition of oxidative stress injury, while decreased after MSC-CM treatment. The expression of miR-143 predicted target proteins, HK2 and ADRB1, decreased under the hydrogen peroxide-exposure, while increased after MSC-CM treatment, which is consistent with the regulatory trend of miR-143. CONCLUSION: MSC-CM might attenuate hydrogen peroxide induced oxidative stress injury via inhibiting apoptosis and regulating some miRNA expression.     

Expression of neurotrophic factors in injured spinal cord after transplantation of human-umbilical cord blood stem cells in rats

We induced percutaneous spinal cord injuries (SCI) using a balloon catheter in 45 rats and transplanted human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) at the injury site. Locomotor function was significantly improved in hUCB-MSCs transplanted groups. Quantitative ELISA of extract from entire injured spinal cord showed increased expression of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and neurotrophin-3 (NT-3). Our results show that treatment of SCI with hUCB-MSCs can improve locomotor functions, and suggest that increased levels of BDNF, NGF and NT-3 in the injured spinal cord were the main therapeutic effect.     

油菜生产中常见障碍及对策

分析了在油菜生产过程中遇到的油菜病态苗、油菜高温热害、油菜冻害、油菜早薹旱花、油莱干旱、油菜渍害和油菜收获后连续阴雨天等常见障碍的症状、发生原因，并针对各障碍提出了相应的防治对策．     

Water Uptake by Seeds in Yellow-seeded Soybean (Glycine max (L.) Merrill) Cultivars with Contrasting Imbibition Behaviors

Abstract

The rate of water uptake by seeds is assumed to be an important factor affecting the susceptibility of seeds to flooding injury, but the traits which could contribute to restricting rapid imbibition by seeds remain undetermined in yellow-seeded soybeans. This study was conducted to determine the possible factors controlling the rate of imbibition in soybeans with yellow seed coats. The imbibition behavior of two yellow-seeded cultivars, Tamahomare and Tachinagaha, with different flooding susceptibilities was examined in relation to initial seed moisture content, the hydration location of the seed surface during imbibition, and the state of the seed coat. Low seed moisture increased the water uptake by Tamahomare intact seeds and even allowed substantially faster imbibition than occurred in its embryos, while in Tachinagaha seed moisture content had little influence on seed imbibition. This rapid imbibition by low-moisture Tamahomare seeds was not due to alterations in the permeability of the seed coat nor in water uptake by the embryo, but rather to increased movement of water along the abaxial sides of the cotyledons. The seed coat of Tamahomare loosened readily upon submergence whilst that of Tachinagaha rather tightly adhered to the embryo, suggesting that the seed coat of Tamahomare adheres very loosely to the embryo and may aid in conducting water laterally between the seed coat and embryo. The degree of adherence of the coat to the embryo and/or the ease with which the coat can be loosened upon hydration appear to play a crucial role in determining the rate of water uptake in yellow-seeded soybeans.     

Macro and microanatomy of some organs of a juvenile male Ganges River dolphin (Platanista gangetica spp. gangetica)

Ganges River dolphins (Platanista gangetica spp. gangetica) are air-breathing, warm-blooded mammals endemic to the Ganges and Karnaphuli rivers of the Indian subcontinent. Nevertheless, very little basic histomorphological research has been conducted on this endangered species. Therefore, this study aimed to describe the morphological features of different organs of P. gangetica. Despite becoming aquatic animals, they showed similarities with terrestrial mammals, such as the pair of lungs and an apical bronchus in the respiratory system, which are pretty standard in ruminants and pigs. However, unlike the terrestrial animal, the tracheobronchial tree was stiffer due to circularly arranged anastomosing plates of the hyaline cartilaginous ring in the trachea, cartilaginous plates in the bronchiole, and thick alveolar septa. The digestive system showed a three-chambered mechanical and glandular stomach similar to the artiodactyles. However, the intestine showed smaller caecum like the monogastric mammal. The urogenital system showed lobulated kidneys, a urinary bladder, a fibroelastic penis with sigmoid flexure, and a long urethral process similar to some terrestrial ruminants. Considering the aquatic environment, all those modifications, unlike terrestrial mammals, are necessary for their adaptation. Thus, this research will broadly help our clinicians and conservationist to take further steps toward disease diagnosis and monitoring of marine health of this endangered species.     

电针疗法对AKI犬的肾功能、钙磷代谢、抗氧化能力以及NRF2信号通路的影响

急性肾损伤(acute kidney injury, AKI)目前已成为犬最主要的一种肾系疾病,尤其在老年犬中发病率逐年上升。近年来,针刺疗法在宠物临床已得到广泛的应用,并逐渐从治疗瘫痪等外科疾病向治疗宠物内科疾病的方向发展。本研究以腺嘌呤为造模药物建立急性肾损伤犬模型,采用电针疗法进行治疗。研究电针疗法对于犬的肾功能、钙磷代谢、抗氧化能力以及对于NRF2通路相关蛋白的影响,探究电针疗法对犬的急性肾损伤的治疗作用。选取24只3～4 kg健康比格犬,随机分为对照组、造模组、常规治疗组、电针干预组、电针治疗组和联合治疗组。第1～15天为造模期,第16～30天为治疗期。试验结束后检测尿比重、血清中尿素氮(BUN)、肌酐(CREA)、尿酸(UA)、钙(Ca²⁺)和磷(P³⁺)的变化;影像诊断X光检测肾变化情况;检测血清及肾组织的超氧化物歧化酶(SOD)和丙二醛(MDA);病理组织学观察各组试验犬肾组织病变的严重程度;采用qRT-PCR和Western blot方法检测各组试验犬肾组织中与抗氧化相关基因和蛋白的表达情况;用免疫组织化学的方法检测肾组织中...