Identification of Hog Cholera Viral Antigen by Immunofluorescence. Application as a Diagnostic and Assay Method

In the absence of detectable cytologic changes in hog cholera virus-infected tissue culture cells, hog cholera viral antigen was readily detected by immunofluorescence. The ability to detect hog cholera viral antigen by this method allowed for determination of infectivity titers and also for titration of homologous antibody. Immunofluorescence made possible the identification, in tissue culture, of hog cholera virus from blood, serum, and spleen extracts of experimentally infected swine. Further applications of this method and its limitations are being investigated.     

Infections of Jute, Maize and Rice ot Revealed by the Standard Blotter Method of Seed Health Testing

In the standard blotter seed health testing of jute, maize and rice some ungerminated seeds, and seedlings with or without symptoms were eventually found to be infected by pathogenic fungi on prolonged incubation any by trans-planting seedlings from blotters to autoclaved soil in pots.     

甘蓝型油菜秦优10号杂交种纯度鉴定的SSR引物筛选

为了建立一套快速可靠的油菜杂交种纯度的鉴定方法,本文以秦优10号及其亲本、杂种ZZH2为试验材料,对前人开发的2对SSR引物(7号引物, 9号引物)进行了再次筛选.结果显示,7号引物不但能很好地区别出混入杂交种中的亲本,还能将杂交种子的同母异父组合种子从杂交种中分离出来,能够用于鉴别秦优10号杂交种子的真伪;9号引物能区分出杂交种和母本,但不能区分开杂交种和父本.同时,本试验利用人工制成的秦优10号杂交种标准样(纯度为100%)以及7份大田鉴定不同纯度梯度的杂交种子对7号引物鉴定结果的准确性进行了验证,鉴定结果与大田鉴定结果基本一致.本文结果将为鉴定秦优10号杂交种纯度提供更准确的技术资料.     

Helicobacter pylori Identification: A Diagnostic/Confirmatory Method for Evaluation

The Helicobacter pylori extra gastric reservoir is probably the oral cavity. In order to evaluate the presence of this bacterium in patients with periodontitis and suspicious microbial cultures, saliva was collected from these and non-periodontitis subjects. PCRs targeting 16S rRNA gene and a 860 bp specific region were performed, and digested with the restriction enzyme DdeI. We observed that the PCR–RFLP approach augments the accuracy from 26.2 % (16/61), found in the PCR-based results, to 42.6 % (26/61), which is an excellent indicator for the establishment of this low-cost procedure as a diagnostic/confirmatory method for H. pylori evaluation.     

SCAR标记技术鉴别榆黄蘑品种

为了建立一套基于DNA分子标记技术快速鉴定榆黄蘑菌株的有效方法,本研究通过对生产上常用的16个榆黄蘑菌株进行SRAP多态性分析,从榆黄蘑2号菌株中扩增获得了一个片段长为537bp的特异片段,将其克隆、测序并设计引物,成功转化为稳定的SCAR标记。试验结果表明,利用该特异SCAR标记,能在1d时间内准确鉴定出榆黄蘑2号菌株。由此可见,SCAR分子标记是一种快速、稳定、准确鉴定榆黄蘑菌株的新方法。     

Use of Tethered Enzymes as a Platform Technology for Rapid Analyte Detection

Background

Rapid diagnosis for time-sensitive illnesses such as stroke, cardiac arrest, and septic shock is essential for successful treatment. Much attention has therefore focused on new strategies for rapid and objective diagnosis, such as Point-of-Care Tests (PoCT) for blood biomarkers. Here we use a biomimicry-based approach to demonstrate a new diagnostic platform, based on enzymes tethered to nanoparticles (NPs). As proof of principle, we use oriented immobilization of pyruvate kinase (PK) and luciferase (Luc) on silica NPs to achieve rapid and sensitive detection of neuron-specific enolase (NSE), a clinically relevant biomarker for multiple diseases ranging from acute brain injuries to lung cancer. We hypothesize that an approach capitalizing on the speed and catalytic nature of enzymatic reactions would enable fast and sensitive biomarker detection, suitable for PoCT devices.

Methods and findings

We performed in-vitro, animal model, and human subject studies. First, the efficiency of coupled enzyme activities when tethered to NPs versus when in solution was tested, demonstrating a highly sensitive and rapid detection of physiological and pathological concentrations of NSE. Next, in rat stroke models the enzyme-based assay was able in minutes to show a statistically significant increase in NSE levels in samples taken 1 hour before and 0, 1, 3 and 6 hours after occlusion of the distal middle cerebral artery. Finally, using the tethered enzyme assay for detection of NSE in samples from 20 geriatric human patients, we show that our data match well (r = 0.815) with the current gold standard for biomarker detection, ELISA—with a major difference being that we achieve detection in 10 minutes as opposed to the several hours required for traditional ELISA.

Conclusions

Oriented enzyme immobilization conferred more efficient coupled activity, and thus higher assay sensitivity, than non-tethered enzymes. Together, our findings provide proof of concept for using oriented immobilization of active enzymes on NPs as the basis for a highly rapid and sensitive biomarker detection platform. This addresses a key challenge in developing a PoCT platform for time sensitive and difficult to diagnose pathologies.     

微生物菌种保藏方法及关键技术

菌种是国家的重要生物资源,也是生产、教学和科学研究的基本材料。为确保菌种的质量和活力,需要正确的菌种保藏方法。阐述了菌种保藏的重要性、菌种保藏常见方法及其存在的问题,探讨了常用菌种的保藏技术及关键点,好的保藏方法可延长菌种的保存时间,又可防止菌种退化。     

Antimicrobial Susceptibility as a Diagnostic Aid in the Identification of Nonfermenting Gram-Negative Bacteria

Antimicrobial susceptibility data regarding nonfermentative, gram-negative bacteria (Pseudomonas, Alcaligenes, Acinetobacter, Moraxella, Flavobacterium) are presented showing that the antibiograms of most species examined can be used as an important auxillary aid in their differentiation.     

Rapid Assessment of Seed Removal and Frugivore Activity as a Tool for Monitoring the Health Status of Tropical Forests

Ecological processes in tropical forests are being affected at unprecedented rates by human activities. Yet, the continuity of ecological functions like seed dispersal is crucial for forest regeneration. It thus becomes increasingly urgent to be able to rapidly assess the health status of these processes in order to take appropriate management measures. We tested a method to rapidly evaluate seed removal rates on two animal‐dispersed tree species, Virola kwatae and V. michelii (Myristicaceae), at three sites in French Guiana with increasing levels of anthropogenic disturbance. We counted fallen fruits, fruit valves, and seeds of each focal fruiting tree in a single 1 m² quadrat, and calculated two indices: the proportion of seeds removed and the proportion of fruits opened by mammals. They both provide an indirect and rapid assessment of frugivore activity. Our results showed a significant decrease in the proportion of removed seeds (16%) and fruits opened (19%) at the most impacted site in comparison with the other two sites (79% for seeds, 60% and 35% for fruits). This testifies to an increased impoverishment of the primate and toucan communities at the disturbed sites. This standardized protocol provides fast information about the health status of the community of seed dispersers and predators and of their seed removal services. It is time‐ and cost‐effective and is not species‐specific, allowing comparisons among sites or over time. We suggest using it with the pantropical Myristicaceae and any other capsule‐producing family to rapidly assess the health status of seed removal processes across the tropics.     

DNA分子标记技术在玉米种子纯度鉴定中的应用

从常规鉴定、生化鉴定及分子标记技术鉴定等方面,阐述了玉米种子纯度鉴定的重要性。进一步对RAPD、RFLP、SSR和AFLP等分子标记技术在种子纯度鉴定和品种真实性分析中的应用潜力及存在问题进行比较,得出SSR分子标记技术是目前种子纯度和品种真实性鉴定中最适宜的技术。     

Starch grain analysis as a Microscopic Diagnostic Feature in the Identification of Plant Material

The starch grain is a diagnostic feature of multiple applications according to the peculiarities and origin of the plant material to be determined. Its morphological characteristics are studied through the analysis of samples from different origin and different preservation conditions, as flours, commercial starches, drugs, spices and archaeological remains (especially carbonized material). The usefulness and importance of the methods and techniques applied in each case are also discussed.     

Use of Rotorod as a Method for the Qualitative Analysis of Walking in Rat

The rotorod test, in which animals walk on a rotating drum, is widely used to assess motor status in laboratory rodents. Performance is measured by the duration that an animal stays up on the drum as a function of drum speed. Here we report that the task provides a rich source of information about qualitative aspects of walking movements. Because movements are performed in a fixed location, they can readily be examined using high-speed video recording methods. The present study was undertaken to examine the potential of the rotorod to reveal qualitative changes in the walking movements of hemi-Parkinson analogue rats, produced by injection of 6-hydroxydopamine (6-OHDA) into the right nigrostriatal bundle to deplete nigrostriatal dopamine (DA). Beginning on the day following surgery and then periodically over the next two months, the rats were filmed from frontal, lateral, and posterior views as they walked on the rotorod. Behavior was analyzed by frame-by-frame replay of the video records. Rating scales of stepping behavior indicated that the hemi-Parkinson rats were chronically impaired in their posture and in the use of the limbs contralateral to the DA-depletion. The contralateral limbs not only displayed postural and movement abnormalities, they participated less in initiating and sustaining propulsion than did the ipsilateral limbs. These findings not only reveal new deficits secondary to unilateral DA-depletion, but also show that the rotorod can provide a robust tool for the qualitative analysis of movement.Open in a separate windowClick here to view.^{(19M, flv)}     

SSR和STS标记在花生栽培品种鉴定中的应用研究

采用10份花生品种材料,对通过数据库查询设计合成的SSR引物和其他作者发表的SSR引物及STS引物进行了评估,并基于品种间简单匹配系数做了聚类分析。获得62个能产生多态性片段的SSR和STS引物对,总共获得427条带,其中291条（68．1％）为多态性带。平均每对引物产生6．88条带,4．69条为多态性带;多态性条带比率为16.7％～100％,PIC值为0．254～0．952,平均为0．760。9对SSR／STS引物,即Lec-1、Ah4-26、Ah4-4、SsS14、SHPAL-1、PG71、PG43、PM36、PG22,对所采用的10份花生品种区分率达到10096。说明SSR和STS标记应用于花生品种鉴定有效。