Respirometric activities of unacclimatized Enterobacter aerogenes and mixed culture bacteria in sequencing batch reactor systems in response to acrylamide and its biodegradation products

The acute effects of acrylamide and its biodegradation products on the respiration activities of microbes during wastewater treatment are not well understood. Herein, unacclimatized mixed culture bacteria and Enterobacter aerogenes from two aerobic treatment systems, Activated Sludge (AS) and Integrated Fixed Film Activated Sludge (IFAS) both of which were sequencing batch reactors (SBR), were studied for their response to acrylamide. Respiration activities and biodegradation rates were determined by both the OxiTop respirometer and batch studies. The experimental results revealed that E. aerogenes in the AS system quickly removed both acrylamide and acrylic acid without the need of an acclimation period, but required two hours for removing acrylic acid in the IFAS system. The mixed culture bacteria in both AS and IFAS systems required 2 hours to acclimatize with acrylamide and 1 hour for acrylic acid, respectively. Acrylic acid was initially polymerized to produce acrylic acid polymer or reacted with ammonia to form acrylamide, resulting in the reduced acrylamide biodegradation rate. Both E. aerogenes and mixed culture bacteria from the AS systems could simultaneously biodegrade acrylamide and acrylic acid whereas only acrylamide was biodegraded by both cultures in the IFAS systems due to the limitation of acrylic acid diffusion. The results also indicated that ammonia inhibited the acrylamide biodegradation by both E. aerogenes and mixed culture bacteria from the AS systems. The unacclimatized E. aerogenes and mixed culture bacteria from the AS systems showed superior performances compared to the ones from the IFAS systems.

Acute effects of acrylamide and its biodegradation products on microbes from SBR wastewater treatment systems were revealed by respirometric activities.     

Rapid and sensitive detection of Penaeus monodon nucleopolyhedrovirus (PemoNPV) by loop-mediated isothermal amplification combined with a lateral-flow dipstick

Several methods such as traditional PCR or nested-PCR, immuno assay and histopathology have been developed for detection of Penaeus monodon nucleopolyhedrovirus (PemoNPV) formerly called monodon baculovirus (MBV). However, these methods have various disadvantages including low sensitivity, long assay time, use of toxic substances or unsuitability for field diagnosis. Loop-mediated isothermal amplification of target nucleotide sequences under isothermal conditions, combined with amplicon detection by chromatographic lateral-flow dipsticks allows for more efficient, field friendly detection within 75 min (not including DNA preparation time). In this study, the LAMP amplicon was biotinylated via an inner LAMP primer designed from a BamHI fragment B, a hypothetical protein gene of PemoNPV under isothermal condition at 63 °C for 1 h. Next, the LAMP product was hybridized at 63 °C for 5 min with an optimal FITC-labeled probe that was designed specifically for the LAMP amplicons. The FITC-labeled biotinylated LAMP product picked up gold-labeled, anti-FITC near the LFD origin and the whole, triple-labeled complex was captured by an immobilized biotin-binding protein to yield a red nano-gold stripe at the LFD test line. With a DNA template extracted from PemoNPV-infected shrimp, the LAMP–LFD detection limit was 0.1 pg, whereas one-step PCR and nested-PCR followed with gel electrophoresis was 1 pg. The LAMP–LFD method gave negative test results with buffer and DNA from shrimp infected with other common shrimp DNA viruses including, Penaeus monodon densovirus (PmDNV) formerly called hepatopancreatic parvovirus (HPV), white spot syndrome virus (WSSV) and Penaeus stylirostris densovirus (PstDNV) formerly called infectious hypodermal and hematopoietic necrosis virus (IHHNV). The test platform can be adapted easily for rapid detection of other shrimp viruses, since the LAMP–LFD combination system was a highly sensitive, specific, convenient, and does not require sophisticated instruments.     

肾癌增殖细胞核抗原与病理及预后关系的研究

为探讨肾癌增殖细胞核抗原（ＰＣＮＡ）与临床病理及预后的关系，采用免疫组织化学Ｓ－Ｐ法对５３例肾癌组织中ＰＣＮＡ进行检测。其中ＰＣＮＡ阳性细胞数和分布呈异质性，ＰＣＮＡ表达与细胞类型、肿瘤分期与分级均相关，ＰＣＮＡ高表达（３￣４级）术后５年生存率明显低于低表达（１￣２级）。结果表明ＰＣＮＡ可以定量地肿瘤分化程度及恶性度，强度ＰＣＮＡ与临床分期结合能更好地判定肾癌的预后，ＰＣＮＡ高表达者易发生转移且预     

Shrimp hepatopancreatic parvovirus detection by combining loop-mediated isothermal amplification with a lateral flow dipstick

Present methods such as traditional PCR, PCR-ELISA, real-time PCR and histopathology for detection of shrimp hepatopancreatic parvovirus (PmDNV) entail various disadvantages including high cost, long assay time or use of toxic substances. Loop-mediated isothermal amplification (LAMP) of target nucleotide sequences under inexpensive isothermal conditions combined with amplicon detection by chromatographic lateral flow dipsticks (LFD) allowed simpler detection within 75 min. Biotinylated LAMP amplicons from the targeted portion of the PmDNA capsid protein gene were produced under isothermal conditions at 63 degrees C for 1h and then hybridized at 63 degrees C for 5 min with an FITC-labeled probe (optimized at 20 pmol) that was specific for the LAMP amplicons (i.e., outside the primer region). The FITC-labeled, biotinylated LAMP product picked up gold-labeled, anti-FITC near the LFD origin and the whole, triple-labeled complex was captured by an immobilized biotin-binding protein to yield a red nano-gold stripe at the LFD test line. With a DNA template derived from PmDNV-infected shrimp, the LAMP-LFD detection limit was 1 ng while that for one-step PCR-electrophoresis was 10 ng. Comparative sensitivity for one nested-PCR-electrophoresis method was 1 ng but for another 0.1 ng. The LAMP-LFD method gave negative test results with DNA extracts from normal shrimp and from shrimp infected with other DNA viruses including monodon baculovirus (MBV), white spot syndrome virus (WSSV) and infectious hypodermal and hematopoietic necrosis virus (IHHNV).     

膀胱癌,肾癌与HLA的相关性研究

人类白细胞抗原（ＨＬＡ）是一重要的遗传标志，一般被用来从遗传角度研究疾病的病因。作者通过研究和分析抗原及基因的频率与正常人及膀胱癌、肾癌患者之间的相关性，发现膀胱癌患者的ＨＬＡ－ＤＲ１０出现的频率高于对照组，肾癌患者组的ＨＬＡ－Ａ３，ＤＲ８的频率明显不同于正常人。