Immunosuppression in human peripheral blood T lymphocytes by fluvastatin

Statins are competitive inhibitors of HMG-CoAreductase, which is the major rate-limiting enzyme thatcontrols the conversion of HMG-CoA to mevalonic acid[1]. Mevalonate derived intermediates, such as isoprenoid,farnyesylpyrophosphate and geranylpyrophosphate, serveas important lipid attachments for the posttranslationalmodification of a variety of proteins such as small GTP-binding proteins of the Ras and Rho superfamily involvedin intracellular signaling [2]. Therefore, apart from the we…     

半胱胺盐酸盐减缓山羊手术后细胞免疫抑制效应的实验研究

Sixteen castrated male goats were randomly allocated into two groups (Control n=8; Experiment n=8) to investigate the effects of cysteamine on surgery-induced cellular immune suppression. The experiment commenced with 13 d of pre-operation (pre-Op), which contained 3 d of roughage-fed period (RP) and 10 d of roughage + concentrate-fed period (RCP), followed by first operation (Op-1) and then the second operation (Op-2). The goats were allowed to have 14 d of recovery between two operations. The fistulas were fixed to rumen walls in Op-1 and to duodenal walls in Op-2. Cysteamine (15 mg x kg(-1) x BW x d(-1)) was added to diet and fed to goats in Exp. group since RCP of pre-Op through whole experimental period. Blood was sampled through jugular vein from goats of both groups at pre-feeding of the last day of RP and RCP, 8 d after Op-1, 4 d and 13 d after Op-2, respectively to determine serum concentration of interlukin-2 (IL-2), cortisol, as well as PHA-stimulated lymphocytic proliferation rate (SI). In pre-operative periods there were no significant differences in concentration of IL-2 (0.82+/-0.1 vs 1.03+/-0.22 microg l(-1)) and cortisol (20.48+/-4.52 vs 20.80+/-9.93 microg l(-1)), as well as lymphocytic SI (90.72+/-7.25 vs 129.22+/-18.59) between Control and Exp. groups. The concentrations of IL-2 (0.82+/-0.1 vs 0.73+/-0.08 vs 0.55+/-0.12 microg l(-1)) and lymphocytic SI (90.72+/-7.25 vs 49.31+/-6.4 vs 7.09+/-1.66) in Control were depressed acutely (P<0.05), but cortisol concentration elevated (20.48+/-4.52 vs 26.67+/-10.51 vs 32.33+/-3.29 microg l(-1)) in post-operative periods (8 d after Op-1 and 4 d after Op-2), compared with those in RCP. While they remained unaltered in Exp. group except a slight decrease of lymphocytic SI at 4 d after Op-2. The different responses of Control and Exp. groups to surgery stress led to a 80-90% higher of IL-2 and about 3 times greater of SI in Exp. than those in Control, which was contributed by cysteamine administration. Our data show that in operated goats the cellular immune was suppressed by surgery stress, cysteamine administration prevented decreases of IL-2 and lymphocytic SI and increase of cortisol induced by surgery stress, consequently attenuates surgery-induced suppression of cellular immune activity.     

Kv1.3 potassium channel-blocking toxin Ctri9577, novel gating modifier of Kv4.3 potassium channel from the scorpion toxin family

Scorpion toxin Ctri9577, as a potent Kv1.3 channel blocker, is a new member of the α-KTx15 subfamily which are a group of blockers for Kv4.x potassium channels. However, the pharmacological function of Ctri9577 for Kv4.x channels remains unknown. Scorpion toxin Ctri9577 was found to effectively inhibit Kv4.3 channel currents with IC₅₀ value of 1.34 ± 0.03 μM. Different from the mechanism of scorpion toxins as the blocker recognizing channel extracellular pore entryways, Ctri9577 was a novel gating modifier affecting voltage dependence of activation, steady-state inactivation, and the recovery process from the inactivation of Kv4.3 channel. However, Ctri9755, as a potent Kv1.3 channel blocker, was found not to affect voltage dependence of activation of Kv1.3 channel. Interestingly, pharmacological experiments indicated that 1 μM Ctri9755 showed less inhibition on Kv4.1 and Kv4.2 channel currents. Similar to the classical gating modifier of spider toxins, Ctri9577 was shown to interact with the linker between the transmembrane S3 and S4 helical domains through the mutagenesis experiments. To the best of our knowledge, Ctri9577 was the first gating modifier of potassium channels among scorpion toxin family, and the first scorpion toxin as both gating modifier and blocker for different potassium channels. These findings further highlighted the structural and functional diversity of scorpion toxins specific for the potassium channels.     

Isolation and characterization of microsatellite markers from reed parrotbill, Paradoxornis heudei (Aves: Timaliidae)

Eleven microsatellite markers were obtained from reed parrotbill, Paradoxornis heudei, using the fast isolation by AFLP of sequences containing repeats (FIASCO) method as part of an effort to compare levels of genetic diversity in different populations of China. Polymorphism levels ranged form 5 to 11 alleles (mean = 9.27) using 32 reed parrotbills, with the observed heterozygosity ranging from 0.037 to 0.80. Six loci were significant deviated from HWE and nine loci showed linkage equilibrium. The utility of these loci on two other Passeriformes species, vinous-throated parrotbill (P. webbianus) and oriental great reed warbler (Acrocephalus orientalis), were also tested.     

Root and shoot traits responses to phosphorus deficiency and QTL analysis at seedling stage using introgression lines of rice

Phosphorous （P） deficiency is a major restraint factor for crop production and plants have developed several mechanisms to adapt to low P stress. In this study, a set of 271 introgression lines （ILs） were used to characterize the responses of seedlings to low P availability and to identify QTLs for root traits, biomass, and plant height under P-deficiency and P-sufficiency conditions. Plant height, total dry weight, shoot dry weight, and root number were inhibited under P-deficiency, whereas maximum root length （MRL） and root-shoot ratio （RS） were induced by P-deficiency stress. Relative MRL （RMRL, the ratio of MRL under P-deficiency to MRL under P-sufficiency con- dition） and relative RS （RRS） were used to evaluate P-deficiency tolerance at the seedling stage. A total of 24 additive QTLs and 29 pairs of epistatic QTLs were detected, but only qRN4 was detected in both conditions. This suggested that different mechanisms may exist in both P supply levels. QTLs for adaptive traits （RMRL, RRS, RRV, and RRDW） and qRN4 consistently expressed to increase trait stability may contribute to P-deficiency tolerance. Twelve intervals were cluster regions of QTLs for P-deficiency tolerance, and one QTL （qRRSS） showed pleiotropic effects on P-deficiency tolerance and drought tolerance. These interesting QTLs can be used in marker-assisted breeding through the target ILs.     

亚麻SRAP反应体系的优化

通过研究亚麻SRAP反应体系中主要因子对扩增结果的影响,建立了亚麻SRAP-PCR反应的优化体系.在20μL的反应体系中将PCR的5个主要成分分别设定8个浓度梯度,结果表明,最适宜的优化浓度分别为:1.5 mmol/L Mg2+、0.3 mmol/L dNTP、1.5 U Tap酶、30 ng/μL模板DNA 90 ng和25 ng/μL引物100 ng.用6个亚麻材料验证优化体系,检测结果显示,多态性高,反应体系的稳定性和可重复性好,为SRAP标记技术在亚麻分子生物学研究方面的应用奠定了基础.     

Preparation and characterization of surface crosslinked TPS/PVA blend films

Surface crosslinked thermoplastic starch (TPS)/PVA blend films were prepared by applying ultra violet (UV) irradiation. Sodium benzoate was used as photosensitizer and induced onto film surface layer by soaking the TPS/PVA films in the photosensitizer aqueous solution. The effects of concentration of photosensitizer aqueous solution, soaking time and UV irradiation dose on the surface photocrosslinking reaction were investigated. Physical properties, such as water contact angle, moisture absorption, swelling degree and solubility in water as well as mechanical properties of the films were measured to characterize the influence of the surface photocrosslinking modification. The obtained results showed that the surface modification considerably reduced the surface hydrophilic character of the TPS/PVA films, enhanced the film’s water resistance and also increased tensile strength and Young’s modulus but decreased elongation at break of the films.     

中国表珠甲螨属二新记录种记述（甲螨亚目：珠甲螨科）

记述表珠甲螨属Epidamaeus 2中国新记录种:变表珠甲螨Epidamaeus variabilis Fujikawa & Fujita,1985及蒙古表珠甲螨Epidamaeus mongolicus Bayartogtokh, 2000,并分别对两种做了重新描述。     

Structural determinants for the ouabain-stimulated increase in Na–K ATPase activity

Recent studies suggest that at low concentrations, ouabain increases Na–K ATPase and NHE1 activity and activates the Src signaling cascade in proximal tubule cells. Our laboratory demonstrated that low concentrations of ouabain increase blood pressure in rats. We hypothesize that ouabain-induced increase in blood pressure and Na–K ATPase activity requires NHE1 activity and association. To test this hypothesis we treated rats with ouabain (1 μg kg body wt^− 1 day^− 1) for 9 days in the presence or absence of the NHE1 inhibitor, zoniporide. Ouabain stimulated a significant increase in blood pressure which was prevented by zoniporide. Using NHE1-expressing Human Kidney cells 2 (HK2), 8 (HK8) and 11 (HK11) and Mouse Kidney cells from Wild type (WT) and NHE1 knock-out mice (SWE) cell lines, we show that ouabain stimulated Na–K ATPase activity and surface expression in a Src-dependent manner in NHE1-expressing cells but not in NHE1-deplete cells. Zoniporide prevented ouabain-induced stimulation of ⁸⁶Rb uptake in the NHE1-expressing cells. FRET and TIRF microscopy showed that ouabain increased association between GFP-NHE1 and mCherry-Na–K ATPase transfected into NHE1-deficient SWE cells. Mutational analysis demonstrated that the caveolin binding motif (CBM) of Na–K ATPase α1 is required for translocation of both Na–K ATPase α1 and NHE1 to the basolateral membrane. Mutations in activity or scaffold domains of NHE1 resulted in loss of ouabain-mediated regulation of Na–K ATPase. These results support that NHE1 is required for the ouabain-induced increase in blood pressure, and that the caveolin binding motif of Na–K ATPase α1 as well as the activity and scaffolding domains of NHE1 are required for their functional association.