猫免疫缺陷综合症的实验研究

<正> 作者描述了具有强烈免疫抑制作用的一株猫白血病病毒(FeLV)的鉴定、实验性感染及致病特性。该毒株从一只自然感染猫白血病病毒的猫胸腺淋巴瘤组织中分离得到。作者称之为猫白血病—艾滋病病毒(FeLVFAIDS)。25只SPF猫经鼻腔、腹腔接种这种病毒后,都能产生持续性的病毒血症及致死性和获得性免疫缺陷综合症(AIDS)。由于接种时猫年龄的不同,可发生急性免疫缺陷综合症和慢性免疫缺陷综合症。前者的接种后存活时间在3月以下,多发生于8周龄以下的猫,后者的存活时间在一年以上,多发生于15周龄以上的猫。猫白血病—艾滋病病毒诱发的免疫缺陷综合症有如下特征:接种后有一个无症状的病毒血症时期;体重逐渐下降;当淋巴组织的淋巴小结增生时,病毒     

ABCB4 missense mutations D243A,K435T,G535D,I490T,R545C,and S978P significantly impair the lipid floppase and likely predispose to secondary pathologies in the human population

Bile salts are natural detergents required to solubilise dietary fat and lipid soluble vitamins. They are synthesised in hepatocytes and secreted into the luminal space of the biliary tree by the bile salt export pump (BSEP), an ATP-binding cassette (ABC) transporter in the canalicular membrane. BSEP deficiency causes cytotoxic accumulation of bile salts in the hepatocyte that results in mild-to-severe forms of cholestasis. The resulting inflammation can also progress to hepatocellular cancer via a novel mechanism involving upregulation of proliferative signalling pathways. A second ABC transporter of the canalicular membrane is also critical for bile formation. ABCB4 flops phosphatidylcholine into the outer leaflet of the membrane to be extracted by bile salts in the canalicular space. These mixed micelles reduce the detergent action of the bile salts and protect the biliary tree from their cytotoxic activity. ABCB4 deficiency also causes cholestasis, and might be expected to cause cholangitis and predispose to liver cancer. Non-synonymous SNPs in ABCB4 have now been described in patients with liver cancer or with inflammatory liver diseases that are known to predispose to cancer, but data showing that the SNPs are sufficiently deleterious to be an etiological factor are lacking. Here, we report the first characterisation at the protein level of six ABCB4 variants (D243A, K435T, G535D, I490T, R545C, and S978P) previously found in patients with inflammatory liver diseases or liver cancer. All significantly impair the transporter with a range of phenotypes exhibited, including low abundance, intracellular retention, and reduced floppase activity, suggesting that ABCB4 deficiency is the root cause of the pathology in these cases.     

A unified mixed-model method for association mapping that accounts for multiple levels of relatedness

As population structure can result in spurious associations, it has constrained the use of association studies in human and plant genetics. Association mapping, however, holds great promise if true signals of functional association can be separated from the vast number of false signals generated by population structure. We have developed a unified mixed-model approach to account for multiple levels of relatedness simultaneously as detected by random genetic markers. We applied this new approach to two samples: a family-based sample of 14 human families, for quantitative gene expression dissection, and a sample of 277 diverse maize inbred lines with complex familial relationships and population structure, for quantitative trait dissection. Our method demonstrates improved control of both type I and type II error rates over other methods. As this new method crosses the boundary between family-based and structured association samples, it provides a powerful complement to currently available methods for association mapping.     

Psoriasis is associated with increased beta-defensin genomic copy number

Psoriasis is a common inflammatory skin disease with a strong genetic component. We analyzed the genomic copy number polymorphism of the beta-defensin region on human chromosome 8 in 179 Dutch individuals with psoriasis and 272 controls and in 319 German individuals with psoriasis and 305 controls. Comparisons in both cohorts showed a significant association between higher genomic copy number for beta-defensin genes and risk of psoriasis.     

Three new species and a new record of tenuipalpid mites (Acari: Tenuipalpidae) from Hungary

Three new tenuipalpid species are described and illustrated from Hungary: Cenopalpus cumanicus sp. nov., Cenopalpus adventicius sp. nov. and Tenuipalpus budensis sp. nov. (Acari: Tenuipalpidae). The authors give an account of one new record of Cenopalpus spinosus (Donnadieu, 1875) found on woody host plants, a species that has not previously been recorded in the Hungarian fauna. Additional species encountered during these surveys are: Brevipalpus lewisi (McGregor, 1949), Cenopalpus pulcher (Canestrini and Fanzago, 1876), Pentamerismus oregonensis McGregor, 1949, and Pentamerismus taxi (Haller, 1877).