Sulphido-leukotriene production from peripheral leukocytes and skin in clinically normal dogs and house dust mite positive atopic dogs

Pathogenesis of canine atopy has not been completely elucidated. In humans, sulphido-leukotrienes (s-LT) play a role in atopy, and increased production of s-LT occurs in the skin and peripheral leukocytes after allergen challenge. The study population included 16 clinically normal and 13 atopic dogs. All atopic dogs had in common a positive reaction (4+) to the intradermal injection of house dust mite (allergen of reference). Blood samples and skin biopsies were collected. Sulphido-LT synthesis by peripheral leukocytes after stimulation was measured, and no statistically significant difference was found between clinically normal and atopic dogs. Sulphido-LT concentrations in skin samples from stimulated and unstimulated sites were measured, and no statistically significant difference was detected between clinically normal and atopic dogs or between lesional and nonlesional skin within the atopic group. Clinical signs of atopic dogs were graded by owners and no correlation was found between their severity and cutaneous concentrations of s-LT. In this study there was no increase in s-LT synthesis in atopic dogs.     

Genetic Control and Host Range of Avirulence Toward Brassica napus Cultivars Quinta and Jet Neuf in Leptosphaeria maculans

ABSTRACT Leptosphaeria maculans causes blackleg of oilseed rape. Gene-for-gene interactions between race PG3 and Brassica napus cv. Quinta were related to interaction between the fungal avirulence (Avr) gene AvrLm1 and the corresponding resistance gene Rlm1. AvrLm1 isolates were aviru-lent on cvs. Doublol, Vivol, Columbus, and Capitol, and no recombinant phenotypes were observed in the progeny of two AvrLm1 x avrLm1 crosses, suggesting that all of these cultivars may possess Rlm1 or genes displaying the same recognition spectrum, or that a cluster of Avr genes is present at the Avrlm1 locus. In one cross, segregation distortion was observed at the AvrLm1 locus that could be explained by interaction between AvrLm1 and one unlinked deleterious gene, termed Del1. Incompatibility toward cvs. Jet Neuf and Darmor.bzh was governed by a single gene, unlinked to AvrLm1 or Del1. This avirulence gene was termed AvrLm4. Preliminary plant genetic analysis suggested the occurrence of a corresponding dominant resistance gene, termed Rlm4, present in the Quinta line analyzed and linked to Rlm1.     

Effect of Host Plant Resistance to Tomato yellow leaf curl virus (TYLCV) on Virus Acquisition and Transmission by Its Whitefly Vector

ABSTRACT The effect that Tomato yellow leaf curl virus (TYLCV)-infected resistant tomato plants may have on virus epidemiology was studied. Four tomato genotypes that exhibit different levels of viral resistance, ranging from fully susceptible to highly resistant, served as TYLCV-infected source plants. Viral acquisition and transmission rates by white-flies following feeding on the different source plants were evaluated. TYLCV transmission rate by whiteflies that had fed on infected source plants 21 days postinoculation (DPI), shortly after the appearance of TYLCV symptoms, was negatively correlated with the level of resistance displayed by the source plant. Therefore, the higher the resistance, the lower the transmission rate. In addition, TYLCV DNA accumulation was shown to be lower in the resistant source plants compared with the susceptible plants. Whitefly survival rate, following feeding on source plants 21 DPI, was similar for all the cultivars tested. Significant differences in whitefly survival were found, however, following feeding on the infected source plants at 35 DPI; here, whitefly survival rate increased with higher levels of resistance displayed by the source plant. At 35 DPI, the susceptible plants had developed severe TYLCV disease symptoms, and transmission rates from these plants were the lowest, presumably due to the poor condition of these plants. Transmission rates from source plants displaying a medium level of resistance level were highest, with rates declining following feeding on source plants displaying higher levels of TYLCV resistance. TYLCV DNA accumulation in whiteflies following feeding on infected source plants at both 21 and 35 DPI was directly correlated with viral DNA accumulation in source plants. Results show that, in essence, the higher the resistance expressed, the less suitable the plant was as a viral source. Consequently, following acquisition from a highly resistant plant, TYLCV transmission by whiteflies will be less efficient.     

Suspected post-vaccinal acute polyradiculoneuritis in a puppy

A 4-month-old German shepherd puppy developed hindquarter weakness after vaccination with a multivalent vaccine. This is suggestive of post-vaccinal polyradiculoneuritis. To date, only 1 similar case has been reported, which may be due to the under-reporting of suspected adverse drug reactions.     

Characterization of mutations in the two-component histidine kinase gene that confer fludioxonil resistance and osmotic sensitivity in the os-1 mutants of Neurospora crassa

Osmotic-sensitive (os-1) mutant alleles in Neurospora crassa exhibit resistance to dicarboximides, aromatic hydrocarbons and phenylpyrroles. We have previously reported that the os-1 mutants can be classified into two groups based on their resistance to fungicides and osmotic stress: type I, which are highly resistant to iprodione and fludioxonil but moderately sensitive to osmotic stress, and type II, which are highly sensitive to osmotic stress but moderately resistant to fungicides. To explain the mechanism of resistance to these fungicides, we cloned and sequenced the mutant os-1 genes that encode putative osmo-sensing histidine kinase. Within the os-1 gene product (Os1p), the type I strains, NM233t and Y256M209, carried a stop codon at amino acid position 308 and a frameshift at amino acid position 294, respectively. These mutation sites were located on the upstream of histidine kinase and the response regulator domains of Os1p, strongly suggesting that type I strains are null mutants. The null mutants, NM233t and Y256M209, were highly resistant to iprodione and fludioxonil; thus Os1p is essential for these fungicides to express their antifungal activity. The amino acid changes in Os1p, 625Pro from Leu, 578Val from Ala, and 580Arg from Gly were found in the type II strains, M16, M155-1 and P5990, respectively. Os1p is novel in having six tandem repeats of 90 amino acids in the N terminal. Each amino acid change of the type II strains was located on the fifth unit of six tandem repeats. Type II strains with single amino acid changes were more sensitive to osmotic stress than the null mutants (type I), indicating that the amino acid repeats of Os1p were responsible for an important function in osmo-regulation.     

棉铃虫卵诱集植物选择试验

在新疆莎车县,对苘麻、玉米、鹰嘴豆、红花等植物对棉铃虫卵的诱集效果进行田间比较试验。结果表明:供试植物对第2代棉铃虫卵的诱集能力明显不同,累积卵量分别为:苘麻13 018粒、鹰嘴豆3 844粒、玉米2 316粒、红花160粒、棉花120粒。苘麻诱集能力最强,持续时间最长,不但可诱集第2代棉铃虫卵,而且可大量诱集第3代棉铃虫卵。     

宰后公牛和母牛尿中儿茶酚胺、肉的最终pH以及剪切力之间的关系

本研究的目的主要是研究应激反应和牛肉品质之间关系。试验牛为16～19月龄混合(n=37303kg)或非混合(n=23279kg)1．5～7岁弗里生公牛和淘汰弗里生母牛，这些试验牛被分成未育肥牛组(n=133195kg)和育肥3个月的育肥牛(n=34252kg)组。一部分背最长肌的肉样从一天连续屠宰227头牛的屠宰场的热分割车间获得，同时尿中的儿茶酚胺的含量也被测量。20h后，测量肌肉样品中最终pH，乳酸盐，肝糖，糖分解潜力，和典型的肌原纤维节长度。15℃熟化20h和90h后分别测量肌肉的剪切力。杂交和纯种公牛尿中的去甲肾腺素含量基本相近，分别为14．86、14．07ng／μmol肌氨酸酐；育肥母牛为15．24ng／μmol，未育肥奶牛尿中的去甲肾腺素含量有所提高(22．28ng／μmol)。杂交公牛尿中肾上腺素含量(9．5ng／μmol肌氨酸酐)较纯种公牛(5．7ng／μmol)高，而未育肥奶牛和育肥奶牛的含量都相对较高，分别为16．67、14．19ng／μmol。对于在育肥厂肥育程度较好的公牛，屠宰前仅需要很短的禁食时间，最终pH是预测牛肉嫩度很好的指标。宰前肌糖原含量较低的刺激对牛肉的剪切力有显著影响，尿中肾上腺素含量较高的个体更易受影响。而母牛对肾上腺素的反应跟糖原的损耗没有必然的联系，最终pH较公牛受影响较小。此外，营养水平中等的个体，例如未育肥母牛，随着蛋白水解循环的降低，牛肉充分嫩化的能力也随之降低。     

在舍内或舍外饲养体系中公猪、阉公猪及母猪肌肉中脂肪酸组成和生育酚的浓度

该研究的目的是为了检测公猪、阉公猪和母猪在舍外饲养条件下对背最长肌极性和中性脂质中脂肪酸组成和生育酚含量的影响。不同性别和饲养条件脂肪的含量没有差别，舍内饲养情况下，母猪和公猪的肌肉极性脂质中n-6高不饱和脂肪酸的含量比阉公猪高。舍外饲养环境易导致公猪比母猪和阉公猪肌肉极性脂质和中性脂质中n-3多不饱和脂肪酸的水平要稍微偏高一些。我们还发现舍外饲养的母猪与舍内饲养的母猪相比，肌肉极性脂质中18：2 n-6高不饱和脂肪酸的水平增加。在公猪肌肉极性脂质和中性脂质中高水平的多不饱和脂肪酸含量并不伴有高水平的VE。