A new system for understanding the biodiversity in different nature reserves:capacity,connectivity and quality of biodiversity

In this paper,we propose a new system for understanding the biodiversity in different conservation areas.It includes three aspects:the capacity,the connectivity and the quality.The capacity refers to the numbers of biodiversity,including absolute and relative richness of the vegetation types Nv and Dv = (Nv-1)/lnA,species numbers S and richness of species dGI = (S- 1)/lnA,and germ plasm resources within a nature reserve,and also the potential biological living space offered by the natural resource.It comprises the total biological resources in a nature reserve.The connectivity refers to the flux of biodiversity,including similarity and connected status of the vegetation types SILi = 2z/(x + y) and species numbers SIc = 2z/(x + y) among different nature reserves.The quality refers to the stability of biodiversity,including relative species richness index RSLi = d/dmax,relative vegetation richness index RVLi =Dv/Dmaxv,fastness to invasion species fLi = 1-Si/St,weighted values,representativeness and vulnerability of special vegetations,special species,CITES species and rare species as the protected targets.     

Production and characterization of the functional fragment of pneumococcal surface protein A

Pneumococcal surface protein A (PspA) is present on the cell wall of Streptococcus pneumoniae pathogen and has an antigenetically variable N-terminal domain. This aminoterminal domain is essential for full pneumococcal virulence, and monoclonal antibodies raised against it protect mice against pneumococcal infections. We have cloned and expressed a 34-kDa N-terminal fragment of PspA in Escherichia coli in a soluble form using the T7 RNA polymerase pET-20b vector system. Nickel chelate affinity purification followed by size exclusion and anion exchange chromatography yielded large amounts of pure and homogeneous protein. Analytical ultracentrifugation sedimentation velocity band and boundary studies showed that the molecule was present in aqueous solutions in a monomeric form with an axial shape ratio of approximately 1:12, typical of fibrous proteins. Sequence analyses indicated an alpha-helical coiled-coil structure for this monomeric molecule with only few loop-type breaks in helicity. The mostly alpha-helical structure of this PspA construct was consistent with circular dichroism spectroscopy data. Based on the ultracentrifugation studies, the circular dichroism spectra, and the PspA's sequence analyses, two structural models for the amino-terminal part of the PspA molecule are proposed. The evident highly charged and polar character of the surface of the modeled structures suggests functional properties of PspA that are related to the prevention of S. pneumoniae interactions with the host complement system.     

The Effects of CFTR and Mucoid Phenotype on Susceptibility and Innate Immune Responses in a Mouse Model of Pneumococcal Lung Disease

Recent studies have reported the isolation of highly mucoid serotype 3 Streptococcus pneumoniae (Sp) from the respiratory tracts of children with cystic fibrosis (CF). Whether these highly mucoid Sp contribute to, or are associated with, respiratory failure among patients with CF remains unknown. Other mucoid bacteria, predominately Pseudomonas aeruginosa, are associated with CF respiratory decline. We used a mouse model of CF to study pneumococcal pneumonia with highly mucoid serotype 3 and non-mucoid serotype 19A Sp isolates. We investigated susceptibility to infection, survival, and bacterial counts from bronchoaviolar lavage samples and lung homogenates, as well as associated inflammatory cytokines at the site of infection, and lung pathology. Congenic CFTR^–/– mice and wild-type (WT)-mice were infected intranasally with CHB756, CHB1126, and WU2 (highly mucoid capsular serotype 3, intermediately mucoid serotype 3, and less mucoid serotype 3, respectively), or CHB1058 (non-mucoid serotype 19A). BAL, lung homogenates, and blood were collected from mice 5 days post-infection. Higher CFU recovery and shorter survival were observed following infection of CFTR^–/– mice with CHB756 compared to infection with CHB1126, WU2, or CHB1058 (P≤0.001). Additionally, CFTR^–/– mice infected with CHB756 and CHB1126 were more susceptible to infection than WT-mice (P≤0.05). Between CFTR^–/– mice and WT-mice, no significant differences in TNF-α, CXCL1/KC concentrations, or lung histopathology were observed. Our results indicate that highly mucoid type 3 Sp causes more severe lung disease than non-mucoid Sp, and does so more readily in the lungs of CFTR^–/– than WT-mice.     

2004 Nomenclature for the chicken major histocompatibility (<Emphasis Type="Italic">B</Emphasis> and <Emphasis Type="Italic">Y</Emphasis> ) complex

The first standard nomenclature for the chicken (Gallus gallus) major histocompatibility (B) complex published in 1982 describing chicken major histocompatibility complex (MHC) variability is being revised to include subsequent findings. Considerable progress has been made in identifying the genes that define this polymorphic region. Allelic sequences for MHC genes are accumulating at an increasing rate without a standard system of nomenclature in place. The recommendations presented here were derived in workshops held during International Society of Animal Genetics and Avian Immunology Research Group meetings. A nomenclature for B and Y (Rfp-Y) loci and alleles has been developed that can be applied to existing and newly defined haplotypes including recombinants. A list of the current standard B haplotypes is provided with reference stock, allele designations, and GenBank numbers for corresponding MHC class I and class II sequences. An updated list of proposed names for B recombinant haplotypes is included, as well as a list of over 17 Y haplotypes designated to date.     

Pneumolysin plays a key role at the initial step of establishing pneumococcal nasal colonization

Nasopharyngeal colonization by Streptococcus pneumoniae is an important initial step for the subsequent development of pneumococcal infections. Pneumococci have many virulence factors that play a role in colonization. Pneumolysin (PLY), a pivotal pneumococcal virulence factor for invasive disease, causes severe tissue damage and inflammation with disruption of epithelial tight junctions. In this study, we evaluated the role of PLY in nasal colonization of S. pneumoniae using a mouse colonization model. A reduction of numbers of PLY-deficient pneumococci recovered from nasal tissue, as well as nasal wash, was observed at days 1 and 2 post-intranasal challenges, but not later. The findings strongly support an important role for PLY in the initial establishment nasal colonization. PLY-dependent invasion of local nasal mucosa may be required to establish nasal colonization with S. pneumoniae. The data help provide a rationale to explain why an organism that exists as an asymptomatic colonizer has evolved virulence factors that enable it to occasionally invade and kill its hosts. Thus, the same pneumococcal virulence factor, PLY that can contribute to killing the host, may also play a role early in the establishment of nasopharynx carriage.     

Circulating parasite antigen(s) in lymphatic filariasis: use of monoclonal antibodies to phosphocholine for immunodiagnosis

Hybridoma cell lines producing monoclonal antibodies (MAb) against a 200 kD antigen found circulating in the sera of microfilaremic patients infected with Wuchereria bancrofti were obtained by immunizing mice with a partially purified antigen preparation. A sensitive MAb (CA101)-based ELISA for measuring circulating parasite antigen was capable of detecting antigen in the sera of 93% of patients with microfilaremia, 46% of those with lymphatic obstruction, and 56% of patients with tropical pulmonary eosinophilia syndrome. Circulating antigen was absent from sera of normal controls, and "false positives" were recorded in only two of 17 patients with nonfilarial helminth infections. By ELISA and immunoblot analysis, it was shown that three of the monoclonals raised to this 200 kD antigen were directed to epitopes of phosphocholine (PC). Two MAb (CA86, CA101) were identified as having the T15 idiotype previously associated with antibodies to the PC of pneumococcal teichoic acid; one was untypeable. All three of these anti-PC MAb reacted with adult, microfilaria, and larval antigen preparations, and by immunoblotting showed multiple banding patterns that indicated the presence of PC determinants on many different antigenic molecules. On the other hand, target antigens of CA101 which were found in the circulation of infected patients were limited to three species with apparent m.w. of 200, 160, and 78 kD. The 200 kD antigen was seen more frequently than the other two antigens. Other T15 anti-PC MAb derived from mice not immunized with filarial antigen showed similar patterns of reactivity with circulating filarial antigen.     

Antibody responses to sheep erythrocytes for White Leghorn chickens differing in haplotypes of the major histocompatibility complex (B)

Lines of White Leghorn chickens were developed by selection for high (HA) or low (LA) antibody response to sheep red blood cells (SRBC) and then backcrossed to provide individuals segregating for haplotypes B13 and B21 of the major histocompatibility complex (MHC) within each selected line. Although antibody response to SRBC was consistently higher in background genome HA than LA, there was a significant interaction between background genome and MHC haplotypes. The interaction resulted from higher antibody response in B13/B21 individuals of line HA and in B21/B21 individuals of line LA. Thus, response to SRBC was dependent on particular haplotype combinations present at the MHC as well as the background genome in which they were expressed.     

中国禾本科植物锈菌补遗

本文对中国禾本科植物锈菌增补了五种,其中两个新种:1、单穗拂子茅夏孢锈Uredo calamagrostidis-emodensis 2、多花剪股颖夏孢锈U. agrostidis-myrianthae;三个中国新记录:3、青篱竹柄锈Puccinia arundinariae 4、阿切尔单胞锈Uromyces archerianus 5、龙爪茅单胞锈U. dactyloctenii。每个种都有描述及附图。标本保藏在中国科学院微生物研究所真菌标本室。     

Blood clearance of Streptococcus pneumoniae by C-reactive protein

C-reactive protein (CRP) has long been known to be an acute phase protein associated with infection and various forms of tissue damage. Recent studies have shown that human CRP can be used to passively protect mice from lethal infection with Streptococci pneumoniae. In this study we have undertaken a detailed examination of the ability of human CRP and rabbit CRP (CxRP) to mediate the blood clearance of pneumococci in mice. We have shown that the optimal activity of these acute-phase proteins requires a functioning complement system, and it can take place even in the xid mouse, which has virtually no naturally occurring anti-pneumococcal antibody in its serum. These studies provide additional evidence that CRP may play a protective role in pneumococcal infections, and it may help postpone the development of fatal levels of pneumococci in the blood, long enough for an effective anti-pneumococcal antibody response to be generated.