Advances in Toxicology of Nε-（carboxymethyl）- lysine （CML）

Advanced glycation end-products （AGEs） are products of non-enzymatic glycation of proteins, lipids or nucleic acids and other macromolecules. To be spe- cific, Nε-（carboxymethyl）-Iysine （CML） is one of the most important components of AGEs, which is wildly distributed in the body and can be formed in vivo or in food processing and heating processes. Previous studies have shown that CML is a ma- jor immunological epitope in AGEs and plays an important role in diabetes and its complications, as well as in the development and progression of aging. This review summarized recent advances in major source, toxicological hazard and control mea- sures of CML.     

Separation of Insecticidal Ingredient of Paecilomyces cicadae （Miquel） Samson

In this study, the insecticidal active substance of the fruiting body of Paecilomyces cicadae （Miquel） Samson that can kill the larvae of Plutella xylostella （Lepidoptera： Plutellidae） was isolated and purified by combined separation with biology experiments for the first time. By means of bioactive guided isolation of 40% ethanol-H2O, dichloromethane, ethyl acetate, n-butyl ethanol, macroporous adsorption resin column, high performance liquid chromatography, and sephadex A-20 column, the insecticidal active compound was purified,and a white powder compound was obtained. The compound was active against the third instar larvae ofP. xylostella in 24, 48, and 72 h at the concentration of 10.0 mg mL-1 with a corrective mortality of （95.1 ± 1.8）, （97.7 ± 1.6）, and （99.1 ± 1.7）%, respectively. The compound was strongly sensitive to the larvae. It was stable at acid environment, and was not sensitive to pepsin, and other chracteristics were studied.     

Biodegradation of High Concentration of p-Nitrophenol （PNP） by Wastewater Microflora

Many nitrophenols tend to persist in the environment and they may become public health hazards. Among nitrophenols, p-nitrophenol （PNP） is a priority pollutant that has been widely used as pesticide. PNP is a toxic compound that enters the environment during manufacturing and processing of a variety of industrial products. This situation generalized its presence in multiple natural ecosystems： rivers, wastewaters, subterranean waters, soil treated by pesticides and urban atmosphere. This study aims to test the ability of wastewater microflora to degrade high concentration of PNP （500 rag/L） aerobically. An identification of the dominant microorganisms involved in the biodegradation is also carried. The cultures are performed using a minimum medium, where PNP is the sole source of carbon, energy and nitrogen. The kinetic of biodegradation is followed for more than 30 days of incubation at 30 ~C on a shaker （150 tours/min）. The obtained results show that more than 90% of PNP initial concentration is decomposed at the end of incubation. The isolation of microorganisms degrading PNP gave two bacterial colonies with different macroscopic aspects. Sequence analysis of 16S ribosomal DNA indicated that the PNP degrading isolates were closely related to members of the species： Pseudomonas aeruginosa and Bacillus cereus.     

Comparative Studies of Substrate and Inhibitor Specificity of Glutathione S-Transferases in Six Tissues of Oxya chinensis （Thunberg） （Orthoptera： Acrididae）

Specific activity, substrate specificity, and kinetic parameters （Km and Vmax） of glutathione S-transferases （GSTs） towards three substrates, 1-chloro-2,4-dinitrobenzene （CDNB）, 1,2-dichloro-4-nitrobenzene （DCNB）, and p-nitrobenzene chloride （pNBC） were investigated in six tissues （foregut, midgut, hindgut, fat body, hemolymph, and muscle） of Oxya chinensis. In addition, the inhibition in vitro （ethacrynic acid, and Cibacron Blue 3GA） of Oxya chinensis in the six tissues was also investigated. Glutathione S-transferase activity was detected in all the six tissues examined. The rank order of GST activities towards CDNB was fat body 〉 midgut 〉 hindgut 〉 muscle 〉 foregut 〉 hemolymph both in females and males. Glutathione S-transferase activities in the fat body in females and males were 1.3- to 10.4-fold and 1.1- to 10.0- fold higher than those in the other tissues. The rank order of GST activities towards the other substrates changed slightly. From these results, it was inferred that GSTs in the fat body and midgut played important roles in detoxifying xenobiotics including insecticides and plant allelochemicals in O. chinensis. In the three substrates examined, CDNB seemed to be the best substrate, followed by pNBC and DCNB. The kinetic parameters of GSTs were different among the six tissues. This suggested that GSTs in different tissues have various affinities and catalytic efficiency to substrates. In vitro inhibition study showed that the median inhibition concentration （IC50） values of the two inhibitors to GSTs from the six tissues were different. The results suggested that the two inhibitors have different inhibition potency to GSTs from the different tissues. The observed changes in kinetic parameters and inhibition in vitro among the six tissues of the insect might suggest that the number and structure of isoenzymes and their rate of expression varied for the different tissues.     

Journal of Northeast Agricultural University （English Edition）

Instruction to Authors Aims and Scope Journal of Northeast Agricultural University (English Edition) is a comprehensive academic journal on agricultural sciences sponsored by Northeast Agricultural Un...     

Journal of Northeast Agricultural University （English Edilion）

Aims and Scope Journal of Northeast Agricultural University （English Edition） is a comprehensive academic journal on agricultural sciences sponsored by Northeast Agricultural University and distributed worldwide. It is a peer reviewed journal published quarterly and mainly publishes review and research articles that reflect the Iatest achievements on crop science, horticulture, plant protection, resource and environment, animal science, veterinary medicine, agricultural engineering and technology, agricultural water conservancy, life science, biotechnology and food science.     

Shelf-Life Extension of Tomato （Lycopersicum esculentum） and Pepper （Capsicum annuum） Using Aqueous Extracts of Some Ethnomedicinal Plants

This research aimed at the use of natural products to extend the shelf life of perishable vegetables. Studies were conducted on the preservative effects of four plant extracts--Xylopia aethiopica, Piper nigrum, Tetrapleura tetraptera and Carica papaya seeds on tomato and pepper. Tomato and pepper were dipped into four different concentrations of aqueous extracts of the four plants as well as water serving as control. The result of the study showed that aqueous extract of all plants extended the shelf life of tomato and pepper with increasing concentration of the extracts, except for Carica papaya seeds which produced significant elongation of 12.0 ±0.6 d and 14.0 ± 0.7 d on tomato and pepper, respectively, at the least concentration of 0.25 mg/mL. The results showed that these ethnomedicinal plants can serve as good and potent sources of natural preservatives which can be used to substitute existing synthetics used in the food industry.     

Assessment of Risk of Establishment of Wheat Dwarf Bunt （Tilletia controversa） in China

Wheat dwarf bunt, caused by Tilletia controversa Kühn (TCK), is an important quarantine wheat disease throughout the world. Based on published research results of the biology and the epidemiology of the disease, the main factors including temperature, humidity, snow cover, and their parameters relating to teliospore germination, infection and epidemics of TCK were determined. The geophytopathological models for the risk analysis of wheat dwarf bunt establishment were modified. Fifty-year meteorologic data from about 500 weather stations in China were used to calculate the probabilities of TCK establishment in different geographic sites with the models. The map that displays the establishment risk of TCK in winter wheat growing regions in China was generated by using geographical information system (GIS). The zones showing high, moderate, low, and very low, including no risk, of TCK establishment accounted for 27.33, 27.69, 38.12, and 6.86% of total winter wheat growing areas in China, respectively. These results will provide useful information to formulate quarantine regulations and wheat importation policy in China.     

Influences of Temperature Regime on Germination of Seed of Wild Soybean（Glycine soja）

As an important plant species with high protein contents,wild soybean(Glycine soja),has drawn much attention and appeared to be useful for the genetic improvement of soybean germplasms.Since temperature is one of the numerous environmental factors affecting the germination of most plants,an experimental study was carried out to determine the effect of temperature on germination of wild soybean(G.soja)seeds.Germination test was conducted by setting up thirty-six constant and alternating temperature regimes,ranging from 5 to 40 ℃(16 h night/8 h day).Responses in germination rate to these temperature regimes were then used to construct a quadratic response surface,giving estimated germination rates with confidence intervals at P ≤ 0.05.The results showed that germination capacity was significantly greater while exposed to constant temperatures of 25 ℃,and under the alternating temperature regime the optimum temperature occurred at the 20/25,25/25,25/30 ℃ regime(16 h/8 h)with the amplitude widened from 0 to 5 ℃.Together with regional monthly climate data,these results could be used to improve and promote the cultivation of wild soybean(G.soja),making it available to develop the location-specific optimum seeding time and to apply weed-control treatments.     

Immunocytochemical Identification and Localization of Diffuse Neuroendocrine System （DNES） Cells in Gastrointestinal Tract of Channel Catfish （Ictalurus punctatus）

To detect distribution and relative frequency of diffuse neuroendocrine system （DNES） cells in the gastrointestinal tract of channel catfish （lctalurus punctatus）, the intestinal tract of channel catfish was divided into seven portions from proximal to distal： the enlarged area after oesophagus, cardia, fundus, pylorus, and anterior, middle, and posterior intestine. Immunohistochemical method using the strept avidin-biotin-complex （SABC） was employed. All antisera between seven portions of the channel catfish were compared statistically using statistical package for the social science （SPSS）. Five types of DNES ceils were determined： neuropeptide Y-immunoreactive （NPY-IR） cells were demonstrated in both anterior and middle intestine; serotonin （5-HT） immunoreactive cells were detected throughout the whole gastrointestinal tract; vasoactive intestinal peptide （VIP） positive cells were at the highest frequency in pylorus; glucagon-immunoreactive （GLU-IR） cells were moderate in number in the fundus and anterior, middle intestine, and no immunoreactivity was determined in the other portions; somatostatin （SOM） positive cells were more abundant in the anterior and middle intestine. The regional distribution and relative frequency of immunoreactive cells in the channel catfish, Ictalurus punctatus, are essentially similar to those of other fish. However, some characteristics are observed in this species, which further proved that the diversity of the physiological function of DNES cells was based on their morphology.