Experimental encephalitozoonosis in neonatal dogs

The in vivo infection of neonatal dogs by the microsporidian protozoan parasite, Encephalitozoon cuniculi, was studied. Microscopic examination of tissues from infected animals showed granulomatous nephritis, meningoencephalitis, hepatitis, and pneumonitis. A large component of the inflammatory infiltrate consisted of plasma cells and lymphocytes. In addition, hyperplasia of B-lymphocyte-dependent regions of lymph nodes and erythrophagocytosis were consistently seen in infected dogs. Infected dogs developed lymphocytosis, hypergammaglobulinemia, anti-encephalitozoon antibodies, and an antigen-specific blastogenic response to E. cuniculi spores. Lymphocyte blastogenic responses to the lectin phytohemagglutinin A (PHA) were depressed compared to controls. Dogs dying during the 2-month experimental trial were bacteremic. The findings of these experiments suggest that postnatal infection results in a demonstrable although seemingly ineffective immune and inflammatory response without detectable clinical disease.     

Comparison of follicular and oocyte development and reproductive hormone secretion during the ovulatory period in Hungarian native breed, Mangalica, and Landrace gilts

Only a very small amount of physiological data is available about the low fertility (mean litter size is 5.7+/-0.8) of Hungarian native breed, Mangalica (M), sows. The aim of the present paper is to reveal the differences in preovulatory follicle development and intrafollicular oocyte maturation between M and Landrace (L) gilts, with special reference to the peri- and postovulatory secretion and peripheral concentrations of estradiol-17beta (E2), progesterone (P4), and luteinizing hormone (LH). The number of preovulatory follicles was 6.8+/-1.4 and 19.6+/-6.6 in M and L gilts, respectively. A lower degree of cumulus expansion and a lower percentage of mature oocytes (TI/M II) was noted in M. Higher LH and E2 peak levels, a longer E2 to LH peak interval, and lower embryo survival was confirmed. Interestingly, despite the lower number of corpora lutea, a higher peripheral blood level of P4 was shown in M than in L gilts. Both diminished follicular development and protracted oocyte maturation may be involved in low fecundity in M, and the present findings may explain these reproductive phenomena.     

Genetic Variation and Virulence on Lr26 in Puccinia triticina

ABSTRACT The genetic relationships between isolates of Puccinia triticina virulent on wheat with the Lr26 resistance gene were studied. The diversity within and between isolates of P. triticina from Israel, Europe, and the United States was determined by virulence on near-isogenic Thatcher lines and by random amplified polymorphic DNA. According to the molecular markers, isolates that were virulent on Lr26 had diversity levels similar to those of Lr26 nonpathogenic isolates. Distances between subpopulations of isolates virulent and avirulent on Lr26 varied and were unrelated to the Lr26 virulence phenotype. Cluster analysis suggested four groups, three of which were closely associated with the geographical origin of the isolates-Israel, the United States, and Europe. All four groups included both Lr26 virulent and avirulent pathotypes. The results showed that Lr26 virulent rust pathotypes are as genetically dissimilar as the rest of the population. The cluster analysis showed that the rust population in Israel includes at least two different subpopulations, both of which contain Lr26 virulent and Lr26 avirulent isolates.     

Does white wine qualify for French paradox? Comparison of the cardioprotective effects of red and white wines and their constituents: resveratrol, tyrosol, and hydroxytyrosol

It is generally believed that the French paradox is related to the consumption of red wine and not other varieties of wine, including white wine or champagne. Some recent studies have indicated that white wine could also be as cardioprotective as red wine. The present investigation compares the cardioprotective abilities of red wine, white wine, and their principal cardioprotective constituents. Different groups of rats were gavaged with red wine, white wine, resveratrol, tyrosol, and hydroxytyrosol. Red wine and its constituent resveratrol and white wine and its constituents tyrosol and hydroxytyrosol all showed different degrees of cardioprotection as evidenced by their abilities to improve postischemic ventricular performance, reduce myocardial infarct size and cardiomyocyte apoptosis, and reduce peroxide formation. It was discovered in this study that although each of the wines and their components increased the enzymatic activities of the mitochondrial complex (I-IV) and citrate synthase, which play very important roles in oxidative phosphorylation and ATP synthesis, some of the groups were more complex-specific in inducing the activity compared to the other groups. Cardioprotective ability was further confirmed by increased expression of phospho-Akt, Bcl-2, eNOS, iNOS, COX-1, COX-2, Trx-1, Trx-2, and HO-1. The results of this study suggest that white wine can provide cardioprotection similar to red wine if it is rich in tyrosol and hydroxytyrosol.     

Comparison of luteinizing hormone, leptin and progesterone levels in the systemic circulation (Vena jugularis) and near the ovarian circulation (Vena cava caudalis) during the oestrous cycle in Mangalica and Landrace gilts

The objective of this study was to evaluate luteinizing hormone (LH) and luteal progesterone (P4) secretion in systemic blood and blood near the ovaries in Mangalica (M) and Landrace (L) gilts by implanting catheters into the Vena jugularis and the Vena cava caudalis via the Vena saphena, respectively. Furthermore, leptin was analyzed in jugular vein blood. Blood was collected twice daily from day 7 to day 19 of the oestrous cycle and frequently (10-min intervals for 6 h) on day 9, day 12 and day 15 in M (n=3) and L gilts (n=4). L gilts had congruent pulsatile LH secretion in both veins, but the LH concentrations in M were always below the assay sensitivity during the luteal phase. In both breeds, episodic P4 secretion was found in the jugular and caval veins, and both sampling site and breed had an influence on P4 secretion (P<0.05). The mean concentration of P4 was higher (P<0.01) in utero-ovarian blood (75.8+/-5.3 in M; 49.6+/-4.2 ng/ml in L) than in the periphery (31.3+/-2.0 in M; 21.2+/-1.8 ng/ml in L). M pigs had a lower number of corpora lutea (9.7+/-2.3 vs. 20.5+/-4.4), and analysis of the P4 secretion ratio per corpus luteum revealed an influence of breed (P<0.01). This ratio was significantly higher in M (3.8+/-0.3 and 8.7+/-0.7 ng/ml) compared with the L gilts (1.4+/-0.1 and 2.8+/-0.3 ng/ml) in the jugular and caval veins, respectively. Blood sampling from the Vena cava caudalis is potentially more precise than from the Vena jugularis for evaluation of ovarian P4 secretion. Both the higher P4 concentration and increased leptin secretion (11.3+/-0.6 vs. 3.0+/-0.1 ng/ml, P<0.05) and consequently the altered LH secretion pattern in the Mangalica may contribute to the lower fecundity of this breed.     

A rapid method for detecting and quantifying bacterial DNA in rust fungal DNA samples

Bacterial DNA contamination of rust fungal DNA can be a significant problem for sequencing the rust fungus. Sequence assembly is much more difficult if the sequence contigs are mixed with bacterial sequence. A quantitative real-time polymerase chain reaction (qPCR) assay was developed to quantify bacterial DNA within rust fungal DNA samples and the results were compared with those obtained from traditional CFU counts. Real-time PCR showed higher values of DNA contamination than CFU. However, the ranking of samples from low to high for bacterial contamination was consistent between the methods. Reasons for the differences between the methods are discussed. The qPCR assay was tested by adding known quantities of Escherichia coli DNA to Puccinia graminis DNA samples. The assay reliably quantified bacterial contamination at > or = 1.0% of the total sample DNA. When bacterial contamination was <1.0%, fungal DNA also occasionally was amplified, nullifying the quantification measurement. However, primer specificity was not simply the product of the ratio of bacterial DNA to fungal DNA. Bacterial contamination could be quantified below 1.0% if the bacterial DNA concentration was approximately 70 pg/mul or greater. Therefore, spiking the fungal samples with a known concentration of E. coli bacterial DNA successfully eliminated the amplification of fungal DNA, making quantification of contaminating bacterial DNA possible for samples with low contamination levels.     

加拿大大豆育种和生产研究概况及展望

通过对加拿大大豆科研和生产概况的阐述,明确了加拿大大豆遗传育种方向、研究内容和方法;分析了加拿大大豆生产、工业发展和市场需求;同时指出了加拿大未来农业和大豆产业的发展趋势和策略。     

中国大豆花叶病抗源和抗性鉴别寄主的鉴定与评价

收集大豆抗大豆花叶病(SMV)抗源和鉴别寄主40份,通过接种Cho和Goodman划分的抗大豆花叶病毒株系SMV G1-G7,了解这些材料对该株系的抗性反应.同时比较了其中部分材料对中国学者划分的SMV Sc1-Sc17株系的抗性反应.结果感病材料无论对SMV G1-G7株系,还是SMV Sc1-Sc17株系均表现感病;但是,齐黄1、科丰1、早18和8101等对SMV G1-G7株系均表现抗病的材料,对SMV Sc1-Sc17株系却表现出部分抗病;而另外一些材料,如:诱变30、徐豆1、文丰5、铁6915、齐黄10和Harosoy等对SMV G1-G7株系的抗性反应却与北美的鉴别寄主相同.结果表明:无论是对 SMV G1-G7株系,还是对SMV Sc1-Sc17株系,抗病材料的抗性遗传基础是相似的;中国一些大豆花叶病毒株系的致病力强于国外的株系.因此,结合国外的SMV株系鉴定系统,创建一套统一的SMV株系鉴定系统是可行的.