By means of the agglutination by the peanut agglutinin(PNA),a population of PNA~+ lymphocytes which bear peanut agglutinin receptors,were separated from the spleen cells of mice.The relative number,functional activity and inducibility of the PNA~+ lymphocytes were examined in the spleen cells of normal and EAC tumor-bea- ring mice.The results indicated that the PNA~+cells of mouse spleen exhibited sup- pressive effect on cellular immunity judging from an assessment of modified local xenogeneic graft versus host reaction(GvHR)in guinea pigs.The GvHR induced by PNA~+-cell-depleted spleen cells(PNA~-)from tumor-bearing mice appeared to be signi- ficantly stronger than that induced by unseparated spleen cells from the same donors. The demonstrations of cytolysis of predominant PNA~+ cells treated with anti-Thy 1 serum and abolishment of suppressive activity of the PNA~+ cells thus pretreated con- firmed the impression that the PNA~+ lymphocytes essentially belong to T cell lineage enriching in T suppressors(Ts).Using the fluorescein labelled PNA(PNA-FITC)tracing technique,it has been observed that the relative number of splenic PNA~+ cells in the tumor bearing mice increased concomitantly with the tumor progression.It was also noted that when normal spleen cells were exposed to cell-free ascitic fluid from EAC- bearing mice for appropriate incubation period,a higher percentage of PNA~+ cells was obtained after incubation,and thus induction of PNA~+cells was shown.The nature of the inducing factor(s)as well as the mechanism of induction remain to be clarified.

Simple oxygenation respirator is mainly used for respiratory failure patients who are failed in being treated with open positive pressure.It can markedly improve the oxygenation concentration and ventilation.Most respiratory failure patients can avoid using mechanical respirator if it is used adequately.Respiratory model Ⅰ,Ⅱ,Ⅲ can be applied according to different type of respiratory failure respectively.It is also very effective to cerebral vascular diseases.The structure of respirator is fit for human physiology without interfering cardiac and pulmonary functions.It has no contraindications and side effect.It is simple,cheap and practical.

To investigate molecular epidemiology of DuCV in Cherry Valley ducks in China,the complete genomes of six DuCV strains,which were detected from Cherry Valley ducks in China between 2007 and 2008,were sequenced.Sequence and phylogenetic analysis were carried out to compare these six strains with another 27DuCV strains from Mulard duck,Muscovy duck,Pekin ducks and Mule duck.The analysis showed that the six DuCV strains exhibited typical genetic features of the family of DuCV,such as a stem-loop structure,three major open reading frames (Rep,Cap and ORF3),four intergenic repeats and the conserved motifs for rolling circle replication and for the dNTP binding domain located in the Rep protein.Phylogenetic analysis of the nucleotide sequences of the complete genome and Cap gene of these strains together with those that have been previously published demonstrated two distinct DuCV genotypes.The DuCV strains with complete genomes containing 1988and 1989 nucleotides clustered in genotype A,whereas the strains with complete genomes containing 1991,1992,1995 and 1996 nucleotides lay in genotype B.The six DuCV strains from Cherry Valley ducks were divided into the two groups.The results of the study provides some insight into the variation of DuCVs in Cherry Valley ducks.

To investigate the relationship of the variation of virulence and the external capsid proteins of the pandemic duck hepatitis A virus type 1(DHAV-1) isolates,the virulence,cross neutralization assays and the complete sequence of the virion protein 1(VP1) gene of nine virulent DHAV-1 strains,which were isolated from infected ducklings with clinical symptoms in Shandong province of China in 2007-2008,were tested.The fifth generation duck embryo allantoic liquids of the 9 isolates were tested on 12-day-old duck embryos and on 7-day-old ducklings for the median embryonal lethal doses(ELD50s) and the median lethal doses(LD50s),respectively.The results showed that the ELD5s of embryonic duck eggs of the 9 DHAV-1 isolates were between 1.9 × 106/mL to 1.44 × 107/mL,while the LD50s were 2.39 × 105/mL to 6.15 × 106/mL.Cross-neutralization tests revealed that the 9 DHAV-1 isolates were completely neutralized by the standard serum and the hyperimmune sera against the 9 DHAV-1 isolates,respectively.Compared with other virulent,moderate virulent,attenuated vaccine and mild strains,the VP1 genes of the 9 strains shared 89.8％-99.7％ similarity at the nucleotide level and 92.4％-99.6％ at amino acid level with other DHAV-1 strains.There were three hypervariable regions at the C-terminus(as 158-160,180-193 and 205-219) and other variable points in VPI protein,but which didn't cause virulence of DHAV-1 change.

The duck circovirus (DuCV) infection in sick ducks from Fujian Province was investigated. The liver samples of 43 sick Muscovy ducks with infectious serositis were collected from 12 duck farms in Fujian Province.Based on the published sequences of DuCV, two primers were designed for the detection of DuCV and four pairs of primers were designed to amplify four overlapping fragments that cover the complete genome of DuCV. The specific PCR products were amplified from positive samples. The fragments were then cloned into pMD18-T vector and sequenced, and the full length genomic sequence of the FJ0601 isolate of DuCV was obtained. PCR analysis showed that the proportion of ducks which were positive for circovirus was 79% and 10 out of the 12 farms were positive. Sequence analysis showed that the complete genome of DuCV-FJ0601 was 1988 bp and possessed features common to the family Circoviridae which included a stem-loop structure and the Rep protein motifs. Homology analysis showed that FJ0601 isolate of DuCV had 97.3%～97.5% nucleotide sequence identity to all the four Taiwan isolates (TC1/2002, TC2/2002, TC3/2002, TC4/2002), 82.9% identity to the America (33753-52) isolate and 82.3% identity to the Germany isolate. Phylogenetic analysis with Clustal W, however,showed that FJ0601 isolate of DuCV was on a common branch with Taiwan isolates, and Germany and America isolates belonged to the other branch.