Immunosupressive mechanism of cornus officinalis glycosides on the corneal allograft rejection in rats

AIM: To investigate the influence of the cornus officinalis glycosides (COG) on immunological function of corneal transplantation model of rats, and to clarify the immunosuppressive mechanism of COG through observing the activation of lymphocytes in blood. METHODS: Wister rats were used as recipients and SD rats were used as corneal graft donors, then the corneal allografts transplantation model on the closed colony rats were set up. Splenocytes proliferation and mixed lymphocyte reaction of Wister rats activated by ConA were observed. The phenotype change of CD4, CD8, CD25 in blood in different time postoperatively were observed by the di-sign flow cytometry, and the rate of CD4/CD8 was calculated. RESULTS: 1. The COG suppressed the proliferation of T lymphocytes and one-way mixed lymphocyte reaction on the corneal allografting. 2. The phenotype change of lymphocytes in boold was as follows: there was no significant difference between the different time of the CD4, CD8 expression and the CD4/CD8 rate in blood of the control group. The CD4 positive cells expressed CD25 postoperatively increased obviously. The CD4/CD8 rate of medicine group had the tendency to decrease. The CD4 positive cells expressed CD25 postoperation in the medicine group were less than that in the control group obviously. CONCLUSION: The suppression of the T lymphocyte proliferation, mixed lymphocyte reaction, CD molecule expressed by the activated T lymphocytes and the IL-2 receptor expression may be the main immunosuppressive mechanisms of Cornus officinalis glycosides on the cell-mediated immunity.     

Relation between the time-spatiotemporal expression of caspase-9 and photoreceptor apoptosis as well as electroretinography in RCS rats

AIM: To investigate the relation between the time- spatiotemporal expression of caspase-9 and photoreceptor apoptosis as well as electroretinography (ERG) in Royal College of Surgeons (RCS) rats. METHODS: Twelve non-pigmented degenerative RCS rats at age of 15, 20, 25, 30 days were sacrificed after ERG examination. The caspase-9 expression was analyzed with immunohistochemical staining, fluoro-metric activity assay and Western blotting. Apoptotic retinal neurons were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) technique. RESULTS: The latency and amplitude of b-wave were (58.60±3.42) ms and (109.07±14.50) mV, (56.45±1.08) ms and (109.00±7.35) mV, respectively, in 15 and 20 days old degenerative RCS rats. The ERG resembled flat form in the degenerative RCS rats at age of 25 and 30 days. TUNEL-positive cells were located only in the outer nuclear layer, mostly prevailed in 25-day-old group. Caspase-9 protein expressed in the rat retina started to be found immunohistochemically in 25-day-old and was most predominant in the inner segment. Fluorometric activity assay showed that caspase-9 activity reached its peak, (10.98±0.13) nmol·g-1·min-1 at 20th day. Western blot assay revealed the small cleavage fragmentation at 20th day. No cleavage fragmentation was revealed in the 15-day-old degenerative RCS rats and all other control rats. CONCLUSION: The activation and time-spatiotemporal expression of caspase-9 are coincidence with photoreceptor apoptosis as well as the loss of vision function in RCS degenerative rats, which implicates the important role of caspase-9 in photoreceptor apoptosis.     

3%啶虫脒乳油对4种蚜虫的田间防治效果

1998～1999年在山西太原进行3%啶虫脒乳油防治棉蚜、麦蚜、菜蚜和苹果黄蚜田间小区药效试验。结果表明 ,啶虫脒对这几种蚜虫均有良好的防治效果。使用3%啶虫脒乳油0.6～0.9g(a.i.)/667m2 或10～20mg/kg稀释液 ,在蚜虫发生盛期喷雾防治 ,防治效果可达90%以上 ,持效期棉蚜、麦蚜、菜蚜可达10d以上 ,苹果黄蚜可达15d以上 ,与生产上推广使用的10%吡虫啉可湿性粉剂1.5g(a.i.)/667m2或25mg/kg稀释液防效相当。是一种理想的防治农作物蚜虫可供选择药剂     

粉锈宁药效与小麦品种对条锈菌感病性关系的研究

在田间小区试验条件下,粉锈宁喷雾防治小麦条锈病,每666.6m~28克用药量对各类型感病小麦品种的效应是有显著差异的,对慢锈品种和前期中感,但抽穗后有抗性的品种均可控制为害,而对极感品种则未能控制产量损失;等比系列用药量对各类型感病品种的效应也是有明显差异的,在 ED_(50)和 ED_(95)(克/666.6m~2)平均值上,极感品种为9.38和74.85,高感品种为4.53和25.43,中感品种为3.62和20.96,慢锈品种为1.82和15.30。根据这一结果,模拟出各类型感病品种大田防治的每666.6m~2适宜用药量,高感品种9—12克,中感品种7—9克,慢锈品种4—6克,并经实践证明,这一剂量标准是可行的。拌种对压低各类型感病品种的成株期病情也有明显差异,造成这种差异的主要原因是各类型品种流行速度不同。     

樱桃致死黄化病病原研究

 在电镜下,樱桃致死黄化病株筛管细胞中,观察到典型的类菌原体,大多数为球状,大小为132-321×168-520nm,无细胞壁,仅有双层细胞膜。抗菌素试验表明,四环素对本病具一定的治疗效果;而青霉素无效。初步认为此病为类菌原体引起的病害。     

苏云金素在水中和植株上的衰减与残留

用ＨＰＬＣ检测了苏云金素在鱼塘水和清水中的衰减速率。清水中该物质的半衰期长达４３３小时；在鱼塘水中苏云素的衰减呈双指数消除模型，开始消除半衰期为２．４３－１０．６８小时，终末消除半衰期为１２８．５７－１４２．０１小时。     

Oocyte transport: Developmental competence of bovine oocytes arrested at germinal vesicle stage by cycloheximide under air

The effects of the medium (TCM 199 or SOFaa) and temperature (20 or 39 C) during meiotic arrest by cycloheximide (CHX) under air on the developmental competence of bovine oocytes after in vitro maturation (IVM) and fertilization (IVF) were investigated. Oocytes were maintained in meiotic arrest by 10 microg/ml CHX in a 50-microl droplet of 25-mM HEPES-buffered TCM 199 (H199) at 39 C or synthetic oviduct fluid (HSOFaa) at 20 or 39 C in air for 24 h. After release from the arrest, the oocytes was matured and fertilized in vitro and their developmental competence was examined. The developmental rate of oocytes arrested in HSOFaa at 20 C to the blastocyst stage was similar to that of non-arrested oocytes but was significantly higher (P<0.05) than that of oocytes arrested at 39 C in H199 or in HSOFaa. In consideration of oocyte transport conditions, we also investigated the meiotic arrest of oocytes maintained in a 0.25-ml straw by CHX individually with 10 microl HSOFaa or as a group (40-50 oocytes) with 170-200 microl HSOFaa at 20 C in air for 24 h. After release from meiotic arrest, the developmental competence of these oocytes was assessed similarly. The developmental rate of oocytes treated with CHX individually was similar to that of those treated with CHX in 50-microl droplet of HSOFaa at 20 C. However, the developmental rate of oocytes treated with CHX as a group was lower than that of oocytes treated with CHX in a 50-microl droplet. Five blastocysts developed from oocytes maintained in meiotic arrest in a plastic straw were transferred to five recipient heifers. Consequently, three recipients became pregnant and 2 calves were delivered. The results of the present study indicate that bovine oocytes treated with CHX in HSOFaa at 20 C under air retain the same developmental competence as non-arrested oocytes.     

Effects of various adjuvants on efficacy of a vaccine against Streptococcus bovis and Lactobacillus spp in cattle

OBJECTIVE: To determine efficacy of vaccines incorporating QuilA, alum, dextran combined with mineral oil, or Freund adjuvant for immunization of feedlot cattle against Streptococcus bovis and Lactobacillus spp. ANIMALS: 24 steers housed under feedlot conditions. PROCEDURE: Steers were randomly assigned to 4 experimental groups and a control group. Animals in experimental groups were inoculated on days 0 and 26 with vaccines containing Freund adjuvant (FCA), QuilA, dextran combined with mineral oil (Dex), or alum as adjuvant. Serum anti-S bovis and anti-Lactobacillus IgG concentrations were measured, along with fecal pH, ruminal fluid pH, and number of S bovis and Lactobacillus spp in ruminal fluid. RESULTS: Throughout the study, serum anti-S bovis and anti-Lactobacillus IgG concentrations for animals in the Dex, QuilA, and alum groups were similar to or significantly higher than concentrations for animals in the FCA group. Serum anti-S bovis and anti-Lactobacillus IgG concentrations were significantly increased on days 26 through 75 in all 4 experimental groups, and there was a linear relationship between anti-S bovis and anti-Lactobacillus IgG concentrations. For animals in the QuilA and Dex groups, mean pH of feces throughout the period of experiment were significantly higher and numbers of S bovis and Lactobacillus spp in ruminal fluid on day 47 were significantly lower than values for control cattle. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that immunization of feedlot steers against S bovis and Lactobacillus spp with vaccines incorporating Freund adjuvant, QuilA, dextran, or alum as an adjuvant effectively induced high, long-lasting serum anti-S bovis and anti-Lactobacillus IgG concentrations. Of the adjuvants tested, dextran may be the most effective.     

套袋对红富士苹果果皮细胞超微结构的影响

红富士苹果果皮细胞超微结构的观察结果表明,未套袋颗粒果皮表层细胞叶绿体片层结构发育较套袋果实发达,至果实采收前,未套袋果液泡染色较深县均匀,而套袋果液泡染色深,呈絮状凝结,这可能是颗粒去袋后花青苷迅速合成,在液泡内大量积累所致。