Antibody response against Trichinella spiralis in experimentally infected rats is dose dependent

ABSTRACT: Domestic pigs are the main representatives of the domestic cycle of Trichinella spiralis that play a role in transmission to humans. In Europe, backyard pigs of small household farms are the most important risks for humans to obtain trichinellosis. Rats might play a role in the transmission of Trichinella spiralis from domestic to sylvatic animals and vice versa. In order to be able to investigate the role of wild rats in the epidemiology of T. spiralis in The Netherlands, we studied the dynamics of antibody response after T. spiralis infections in experimental rats, using infection doses ranging from very low (10 muscle larvae, ML, per rat) to very high (16 000 ML per rat). To evaluate the feasibility of rats surviving high infection doses with T. spiralis, clinical and pathological parameters were quantified. Serological tools for detecting T. spiralis in rats were developed to quantitatively study the correlation between parasite load and immunological response. The results show that an infection dose-dependent antibody response was developed in rats after infection with as low as 10 ML up to a level of 10 000 ML. A positive correlation was found between the number of recovered ML and serum antibody levels, although specific measured antibody levels correspond to a wide range of LPG values. Serum antibodies of rats that were infected even with 10 or 25 ML could readily be detected by use of the T. spiralis western blot 2 weeks post infection. We conclude that based on these low infection doses, serologic tests are a useful tool to survey T. spiralis in wild rats.     

Catalase in manipulation buffer enhances the developmental competence of DNA-injected embryos

To improve the efficiency of transgenesis, we investigated the effects of a radical scavenger during microinjection on the development to blastocysts or pups of mouse pronuclear embryos, microinjected with the enhanced green fluorescent protein (EGFP) transgene. When embryos were microinjected in medium containing 0-1,000 units/ml catalase, the developmental rate to blastocysts was significantly higher (P<0.01) in 100-units/ml catalase (81%) than those in 0 and 1,000 units/ml (56 and 65%). To investigate the ontogenetic ability of DNA-injected embryos, EGFP-injected embryos manipulated under 0 or 100 units/ml catalase were transferred separately to recipient mice. The proportion of fetuses derived from EGFP-injected embryos manipulated under 100 units/ml catalase (29%) was significantly higher (P<0.05) than that manipulated under 0 units/ml catalase (19%). Furthermore, the numbers of transgenic pups were 17 in 100 units/ml catalase and 14 in 0 units/ml catalase. The results of the present study indicate that scavenging reactive oxygen species during in vitro micromanipulation is beneficial for the development of DNA-injected embryos.     

Estimation of rubberwood production in Cambodia

We estimated the production of rubberwood from 1996 to 2011 in Cambodia. We employed data from interview surveys with three rubberwood processing companies and statistics from estate rubber plantations and wood retailing companies. The result was that the end use of rubberwood in Cambodia was the sawntimber products, being exported to Vietnam and China. The yield rate from rubberwood stumpage into sawn timber was between 11.6 and 14.9%, closely matching the rates of Malaysia and Thailand. The average production of rubberwood roundwood from 1996 to 2011 was 254,697 m³/year, of which sawn timber as well as residuals in secondary processing was 84,559 and 170,138 m³/year, respectively. Although the timber production of Cambodia has declined sharply due to the strict restriction of natural forest logging, rubberwood could explain more than 60% of the domestic industrial roundwood production from 2000. We suggest the necessity of monitoring the expansion of rubber plantations in new rubber producing countries and linking the rubberwood production with the regional wood resource management.     

Amino acid composition of rice callus tissue grown with different kinds of nitrogen sources

There have been several papers dealing with the difference in chemical composition between callus tissue and normal parent tissue. WEINSTEIN, TULECKE, NICKELL, and LAURENCOT (1–3) revealed, in a series of papers, that the contents of amino acids, sugars, and nucleic acids often differed strikingly between callus and normal tissue of Agave toumeyana Trel. (1), Ginkgo biloba, L. (2), and PAUL's scarlet rose (3). STEWARD, THOMPSON, and POLLARD (4) also reported that the content of some amino acids of rapidly growing and randomly proliferating tissue is outstandingly different from that of normal tissue.     

The study on method to draw large-scale soil map in diluvial soil area in Hokkaido, using digital elevation data for a 10 m grid

(pp. 59–66)
In order to understand the detailed soil distribution of a terrace with a diluvial deposit, the method to draw a large-scale soil map was studied in Urausu Town of Sorachi district by combinig soil survey and digital elevation data for a 10 m grid.
The results are summarized as follows:

• 1) 

  From a soil survey, soils in the research area were classified into 3 soil series groups according to Classification of Cultivated Soils in Japan, Third Approximation, which were Skeletal Terrace Brown Forest Soils, Fine-textured Aquic Brown Forest Soils and Fine-textured Haplic Gray Upland Soils. In addition, Fine-textured Haplic Gray Upland Soils · were classified into 2 categories based on the abundance of gravel in the subsoil.

       

The effect of ornithine and citrulline on tile utilization of arginine in rice callus tissue

There are many reports on the effect of arginine on the growth of cultivated tissues or organs. Arginine usually enhances the growth of tissues and organs (1-9).     

Genetic diversity of the entomopathogen<Emphasis Type="Italic">Verticillium lecanii</Emphasis> on the basis of vegetative compatibility

Forty-three isolates ofVerticillium lecanii from insects, phytopathogenic fungi and other substrates were tested for vegetative compatibility by observing heterokaryon formation among complementary nitrate-nonutilizing (nit) mutants.nit mutants were isolated from 42/43 strains examined. Twenty-one isolates were self-incompatible, and the remaining 21 isolates were divided into 14 vegetative compatibility groups (VCGs): ten containing only a single strain each, and the remaining four containing two to four isolates each. Members of isolates in each of these VCGs all shared the same IGS haplotype. Further, the isolates within a VCG were correlated with one another in part by fragment patterns of mt-LrDNA, -SrDNA, Bt-2 and H4 region, by PCR-RFLP and -SSCP, but not by dsRNA. Two isolates belonging to VL-J2 have high virulence to aphids, whereas strains from VL-J1 lack this character. These findings indicate that two VCGs (VL-J1 and -J2) may originate from two distinct clonal lineages. Alternatively, high VCG diversity and HSI frequency ofV. lecanii might be associated with an array of distinct lineages. These data not only suggest relationships among DNA polymorphisms, virulence, and VCG, but also demonstrate genetic heterogeneity ofV. lecanii. http://www.phytoparasitica.org posting Sept. 30, 2003.     

Nitrate adsorption in some andisols developed under different moisture conditions

Nitrate leaching from agricultural lands is one of the most critical problems related to both environmental quality and human health. Although in many studies surfacecharge properties of and nitrate adsorption in soils have been analyzed in tropical and subtropical regions, fewer studies have been conducted on the nitrateretention properties of allo phanic Andisols. The objectives of the present study were to examine the potential nitrate adsorption capacity and the factors affecting nitrate retention in topsoils and subsoils of three Andisols Tokaachi, Hokkaido. Nitrate adsorption at pH 6.0 was found to be low or negligible even in the subsoil of a Haplic Wet Andisol (Melanaquands), despite the high clay content, Nitrate adsorption maxima calculated from the Langmuir equation were higher in the lower horizons of a Haplic Andisol (Melanudands) and a Lowhumic Andisol (Hap ludands), which were developed under moderate to moderately dry moisture conditions and displayed a high allophane content and a low total carbon content. The nitrate adsorption of the aliophanic Andisols was much higher than that reported from other studies conducted in Ultisols and Oxisols, which are rich in iron oxides. The potential capacity to adsorb nitrates and retard nitrate movement should be taken into account in predicting the fate of nitrate in soils and the consequent mitigation of groundwater contamination.