具有最大代数免疫度的偶数元布尔函数的计数

利用级联的思想研究具有最大代数免疫度的布尔函数的计数问题, 给出达到最大代数免疫度的偶数元布尔函数个数的一个新的下界, 该下界优于已有的下界结果。     

复方中草药添加剂对银香鸡生长性能及免疫功能的影响

选用黄芪、党参、当归、枸杞子、刺五加、山楂和甘草7种补益类中草药作饲料添加剂,添加到银香雏鸡日粮中进行饲养试验,以研究复方中草药添加剂对银香鸡生长性能和免疫机能的影响。试验各组基础日粮相同,试验组添加1%中草药,抗生素对照组添加50mg/kg杆菌肽梓,空白对照组只是基础日粮。试验测定试验鸡体重、增重及免疫器官相对重,于3周龄时接种新城疫疫苗检测血清抗新城疫抗体效价评价中草药添加剂的免疫促进作用。结果表明,6周龄试验组鸡体重和增重与抗生素对照组体重和增重相比差异不显著(P0.05),与空白对照组体重和增重相比差异显著(P0.05),复方中草药添加剂与抗生素具有同样的促生长作用;试验组脾脏和法氏囊相对重,血清抗新城疫抗体效价都显著高于对照组,复方中草药饲料添加剂对银香鸡有免疫促进作用。     

Identification of chicken lysozyme <Emphasis Type="Italic">g</Emphasis>2 and its expression in the intestine

Lysozyme is an important component of the innate immune system, protecting the gastrointestinal tract from infection. The aim of the present study was to determine if lysozyme is expressed in the chicken (Gallus gallus) intestine and to characterise the molecular forms expressed. Immunohistochemical staining localised lysozyme to epithelial cells of the villous epithelium along the length of the small intestine. There was no evidence for lysozyme expression in crypt epithelium and no evidence for Paneth cells. Immunoblots of chicken intestinal protein revealed three proteins: a 14-kDa band consistent with lysozyme c, and two additional bands of approximately 21 and 23 kDa, the latter consistent with lysozyme g. RT-PCR analyses confirmed that lysozyme c mRNA is expressed in 4-day, but not older chicken intestine and lysozyme g in 4- to 35-day chicken intestine. A novel chicken lysozyme g2 gene was identified by in silico analyses and mRNA for this lysozyme g2 was identified in the intestine from chickens of all ages. Chicken lysozyme g2 shows similarity with fish lysozyme g, including the absence of a signal peptide and cysteines involved in disulphide bond formation of the mammalian and bird lysozyme g proteins. Analyses using SecretomeP predict that chicken lysozyme g2 may be secreted by the non-classical secretory pathway. We conclude that lysozyme is expressed in the chicken small intestine by villous enterocytes. Lysozyme c, lysozyme g and g2 may fulfil complimentary roles in protecting the intestine.Received 4 August 2004; received after revision 1 September 2004; accepted 7 September 2004     

The scorpine family of defensins: gene structure,alternative polyadenylation and fold recognition

Small cationic antimicrobial peptides (SCAMPs) as effectors of animal innate immunity provide the first defense against infectious pathogens. This class of molecules exists widely in invertebrate hemolymph and vertebrate skin secretion, but animal venoms are emerging as a new rich resource. Scorpine is a unique scorpion venom defensin peptide that has an extended amino-terminal sequence similar to cecropins. From the African scorpion Opistophthalmus carinatus venom gland, we isolated and identified several cDNAs encoding four new homologs of scorpine (named opiscorpines 1–4). Importantly, we show for the first time the existence of multiple opiscorpine mRNAs with variable 3 untranslated regions (UTRs) in the venom gland, which may be generated by alternative usage of polyadenylation signals. The complete opiscorpine gene structure including its promoter region is determined by genomic DNA amplification. Two large introns were found to be located within the 5 UTR and at the boundary of the mature peptide-coding region. Such a gene structure is distinct, when compared with other scorpion venom peptide genes. However, a comparative promoter analysis revealed that both opiscorpine and scorpion venom neurotoxins share a similar promoter organization. Sequence analysis and structural modeling allow us to group the scorpines and scorpion long-chain K-channel toxins together into one family that shares a similar fold with two distinct domains. The N-terminal cecropin-like domain displaying a clear antimicrobial activity implies that the scorpine family represents a group of real naturally occurring hybrids. Based on the phylogenetic analysis, a possible cooperative interaction between the N and C domains is elucidated, which provides an evolutionary basis for the design of a new class of anti-infectious drugs.Received 5 April 2004; accepted 17 May 2004     

Neural regulators of innate immune responses and inflammation

The nervous system regulates immune function and inflammation. Experimental evidence shows an important role of the autonomic nervous system in the bidirectional communication between the brain and the immune system, underlying the ability of the brain to monitor immune status and control inflammation. Here we review the involvement of the autonomic nervous system in regulating inflammation, with a focus on the vagus nerve. The clinical implications of the recently discovered anti-inflammatory role of the efferent vagus nerve are also discussed.Received 8 March 2004; received after revision 26 April 2004; accepted 29 April 2004     

Recognition of bacterial peptidoglycan by the innate immune system

The innate immune system recognizes microorganisms through a series of pattern recognition receptors that are highly conserved in evolution. Peptidoglycan (PGN) is a unique and essential component of the cell wall of virtually all bacteria and is not present in eukaryotes, and thus is an excellent target for the innate immune system. Indeed, higher eukaryotes, including mammals, have several PGN recognition molecules, including CD14, Toll-like receptor 2, a family of peptidoglycan recognition proteins, Nod1 and Nod2, and PGN-lytic enzymes (lysozyme and amidases). These molecules induce host responses to microorganisms or have direct antimicrobial effects.Received 15 January 2003; received after revision 28 February 2003; accepted 26 March 2003     

自组织方法(GMDH)中准则的抗干扰性

自组织方法是近二十年来发展起来的一种新的建模方法, 其基本思想源于生物进化和自然选择理论, 在运用此方法对复杂系统建模时, 一个重要的问题就是在噪声数据情形下, 如何找到那些能够筛选出系统正确模型结构的准则, 即准则的抗干扰性问题。本文对此进行了一定的探讨, 提出了在有限和无限数据样本上准则抗干扰性问题研究的有关理论和方法, 对在噪声数据下复杂系统的建模具有指导意义。     

Virus-immune T cells and the major histocompatibility complex: Evolution of some basic concepts over the past two years

Cellular and Molecular Life Sciences -