Evaluation of rapid post-mortem test kits for bovine spongiform encephalopathy (BSE) screening in Japan: Their analytical sensitivity to atypical BSE prions

A classical type of bovine spongiform encephalopathy (C-BSE), recognized in 1987, had a large impact on public health due to its zoonotic link to variant Creutzfeldt-Jakob disease by the human consumption of dietary products contaminated with the C-BSE prion. Thus, a number of countries implemented BSE surveillance using rapid post-mortem test kits that were approved for detection of the C-BSE prion in the cattle brain. However, as atypical BSE (L- and H-BSE) cases emerged in subsequent years, the efficacy of the kits for the detection of atypical BSE prions became a matter of concern. In response to this, laboratories in the European Union and Canada evaluated the kits used in their countries. Here, we carried out an evaluation study of NippiBL®, a kit currently used for BSE screening in Japan. By applying the kit to cattle brains of field cases of C-BSE and L-BSE, and an experimental case of H-BSE, we showed its comparable sensitivities to C, L-, and H-BSE prions, and satisfactory performance required by the European Food Safety Authority. In addition to NippiBL®, two kits (TeSeE® and FRELISA®) formerly used in Japan were effective for detection of the L-BSE prion, although the two kits were unable to be tested for the H-BSE prion due to the discontinuation of domestic sales during this study. These results indicate that BSE screening in Japan is as effective as those in other countries, and it is unlikely that cases of atypical BSE have been overlooked.     

木质素柴油制备工艺优化与理化性质评价

介绍了一种新型木质素柴油的制备工艺优化方法及其理化性质评价。根据添加木质素的比例、乳化剂的添加量和等影响因素进行正交试验设计,分别选择添加木质素的量为总质量2%、3%和4%的比例,以乳化剂的用量为4%、5%和6%,HLB为8.3、8.8和9.3以及0.2、0.3和0.4 g的助乳化剂用量的不同等条件为水平标准,配制了多种不同比例的乳化油,最终筛选乳化条件为：HLB值为9.3,乳化剂的用量为6.0%,助乳化剂的加入量为1.2%,乳化温度为室温,乳化时间2 min。同时还针对氧化安定性、含硫量、酸度、10%蒸余物残炭、铜片腐蚀、机械杂质、运动粘度、凝点、闪点（闭合）、十六烷值、馏程、密度十二项指标进行了国家标准检测均高于GB 252-2000轻柴油的国家标准。其中木质素柴油的十六烷值均到了46.1和48.8,远远超过了45的国家标准;这对开发柴油的替代燃料,缓解燃料供需紧张矛盾,降低燃料消耗率等都有重大意义。     

用一个相对简单的方法来探测核苷酸替代模型的异质性

对于可观察到的分子序列进化模型的不同,提出一个相对简单的方法——卡方检测,来检测在DNA序列间替代过程的同质性。这个卡方检测方法不管在座位间下列3个条件是否满足皆是成立的：（1）替代率的异质性;（2）进化率／模型的相关性;（3）替代模型的变异。计算机模拟也显示出卡方检测在各种生物学条件下的序列进化模型是非常有效的。在真实数据中,11种节肢动物线粒体DNA的比较中发现,水蚤或卤虫与其他9种节肢动物以高百分比违背了同质性进化模型假设,显然是由于AT含量高而引起的,且在两种蚊子的线粒体DNA比较中发现,其满足同质性假设仅有7．69％。还比较了卡方淦测与Kumar and Gadagkar的ID检测之间的效能差异：在较为复杂的模型下,卡方检测效率在许多情况下较ID检测方法略高;并且在犯Ⅰ-型错误以及卡方测验的效率曲线中清楚地表明我们的方法是保守的,而Kumar等的方法是不保守的。     

Outline of an Explanatory Account of Cladistic Practice

A naturalistic account of the strengths and limitations of cladistic practice is offered. The success of cladistics is claimed to be largely rooted in the parsimony-implementing congruence test. Cladists may use the congruence test to iteratively refine assessments of homology, and thereby increase the odds of reliable phylogenetic inference under parsimony. This explanation challenges alternative views which tend to ignore the effects of parsimony on the process of character individuation in systematics. In a related theme, the concept of homeostatic property cluster natural kinds is used to explain why cladistics is well suited to provide a traditional, verbal reference system for the evolutionary properties of species and clades. The advantages of more explicitly probabilistic approaches to phylogenetic inference appear to manifest themselves in situations where evolutionary homeostasis has for the most part broken down, and predictive classifications are no longer possible.     

Diagnosis of Helicobacter pylori

The different invasive and noninvasive diagnostic tests for Helicobacter pylori have been applied mainly in emerging countries. Molecular methods have been developed, especially a test for detection of H. pylori and its clarithromycin resistance directly from stools. The long-term effects of eradication on histologic lesions have been studied in a meta-analysis and the prognostic value of post-treatment in gastric mucosa-associated lymphoid tissue lymphoma has been assessed. An operating link for gastritis assessment (the OLGA staging) has also been published. Attempts to simplify the urea breath test protocol have been made, and new stool antigen tests have been proposed and compared to those previously available.     

Probability Density Functions Describing 24-Hour Inhalation Rates for Use in Human Health Risk Assessments: An Update and Comparison

Inhalation rates are used for quantifying inhalation health risks. The time-activity-ventilation (TAV) approach has had longstanding acceptance for estimating inhalation rate (IR) as a time-weighted average across a number of activity levels comprising a typical day. Probability density functions (PDFs) describing 24-hour inhalation rates were updated in this study by incorporating supplemental minute volume (V _i ) and time-activity (t _i ) data published since the time of the previous study and by correlating V _i with metabolic equivalents (METs) for the physical activities at the time of measurement. The metabolic correlations are an improvement over the previous study because they enable interpolation to fill data gaps where V _i data are sparse or absent for certain age groups at specific levels of physical activity. The updated PDFs were developed using Monte Carlo simulation and can be described with log normal distributions. The updated PDFs were compared with IR distributions developed through two other approaches: the metabolic energy conversion (MEC) approach; and the doubly labeled water (DLW) approach. Compared to the previous TAV estimates, this study's PDFs suggest lower IR for toddlers and teenagers, higher IR for adults and seniors, and similar IR for infants and children.     

Evaluation of a novel monoclonal-based antigen-in-stool enzyme immunoassay (Premier Platinum HpSA PLUS) for diagnosis of Helicobacter pylori infection in Vietnamese children

Background: Helicobacter pylori infection is difficult to diagnose in children, especially in developing countries where noninvasive methods such as urea breath test are often not available. We evaluate the sensitivity and specificity of a new monoclonal antibody-based antigen-in-stool enzyme immunoassay (Premier Platinum HpSA PLUS) for diagnosis of H. pylori infection in Vietnamese children.
Materials and Methods: Sensitivity of the antigen-in-stool test was evaluated in 232 children, 3–15 years of age, who were positive for H. pylori infection by culture from biopsies. For evaluation of the specificity 98 children of similar age with nongastrointestinal conditions and who were negative for H. pylori infection by serologic assays were included with blood and stool samples.
Results: Of the 232 culture-positive children, 224 were also positive by Premier Platinum HpSA PLUS. Of the 98 control children, 93 were H. pylori negative also in the stool test. The sensitivity of Premier Platinum HpSA PLUS was thus 96.6% (95% CI 93.3–98.5) and the specificity was 94.9% (95% CI 88.5–98.3).
Conclusions: The findings have demonstrated Premium Platinum HpSA PLUS to be a reliable method for detection of H. pylori infection also in children in our area.     

The teleomorph of Leptographium yunnanense, discovered in crosses among isolates from Thailand, China, and Japan

A teleomorph was discovered in crosses among isolates of Leptographium yunnanense isolated from Pinus spp. originating in Thailand, China, and Japan. The ascocarps are black, globose to subglobose, and lacking necks. Ascospores are hyaline, 1-celled, surrounded by hyaline sheaths, and appear cucullate in side view, quadrangular in face view, and triangular in end view. Three species were known to have teleomorphs morphologically similar to the present fungus. However, their anamorphs were distinguishable from L. yunnanense. Thus, this teleomorph is described as Grosmannia yunnanensis. Contribution No. 214, Laboratory of Plant Parasitic Mycology, Graduate School of Life & Environmental Sciences, University of Tsukuba.     

Tests for genotoxicity and mutagenicity of furan and its metabolite cis-2-butene-1,4-dial in L5178Y tk mouse lymphoma cells

Furan is found in various food items and is cytotoxic and carcinogenic in the liver of rats and mice. Metabolism of furan includes the formation of an unsaturated dialdehyde, cis-2-butene-1,4-dial (BDA). In view of the multifunctional electrophilic reactivity of BDA, adduct formation with protein and DNA may explain some of the toxic effects. Short-term tests for genotoxicity of furan in mammalian cells are inconclusive, little is known for BDA. We investigated BDA generated by hydrolysis of 2,5-diacetoxy-2,5-dihydrofuran for genotoxicity in L5178Y tk^+/− mouse lymphoma cells using standard procedures for the comet assay, the micronucleus test, and the mouse lymphoma thymidine kinase gene mutation assay, using 4-h incubation periods. Cytotoxicity was remarkable: cell viability at concentrations ≥50 μM was reduced to <50%. In the dose range up to 25 μM, viability was >90%. Measures of comet-tail length and thymidine–kinase mutant frequency were increased 1.6- and 2.4-fold above control, respectively. Analysis of three fully independent replicates with a linear mixed-effects model showed a highly significant increase with concentration for both endpoints. Compared to methyl methanesulfonate used as a positive control, BDA was of similar potency with respect to genotoxicity, but it was much more cytotoxic. Furan added to cell cultures at doses that resulted in time-averaged effective concentrations of up to 3100 μM was neither cytotoxic nor genotoxic. A potential cross-linking activity of BDA was investigated by checking whether gamma radiation-induced DNA migration in the comet assay could be reduced by pre-treatment with BDA. In contrast to the effect of the positive control glutaraldehyde, BDA treatment did not reduce the comet tail length. On the contrary, an increase was observed at ≥100 μM BDA, which was attributable to early apoptotic cells. Although BDA was found to be a relatively potent genotoxic agent in terms of the concentration necessary to double the background measures, cytotoxicity strongly limited the concentration range that produced interpretable results. This may explain some of the inconclusive results and indicates that non-genotoxic effects must be taken into account in the discussion of the modes of toxic and carcinogenic action of furan.     

Ames test evaluation of two commercially available zero-valent nickel compounds

Zero-valent nickel compounds are organometallic chemicals that are used in synthetic applications and may also occur as intermediates in nickel-catalyzed hydrogenation reactions used in food processing. Few studies have been performed on their possible genotoxic actions. We have tested two commercially available examples of this class of compounds. Solubility and stability were examined. Mutagenicity testing did not confirm a previous report that bis(1,5-cyclooctadiene)nickel is positive in the Ames assay. No stimulation of lipid peroxidation was observed in studies of bovine erythrocytes exposed in vitro. Our results do not indicate that zero-valent nickel compounds have genotoxic effects.