萝卜花药培养再生植株染色体倍数FCM分析及田间观察

采用流式细胞仪(FCM)对萝卜的20株花药培养再生植株进行倍性鉴定。结果显示:流式细胞仪清楚地显示了每份材料的DNA含量,其中单倍体、二倍体、四倍体、嵌合体的比例分别为20%、30%、25%、25%,并对照再生植株田间生长情况,从形态学角度验证了FCM分析的准确性。     

简评梨树的九种树形

通过在生产中的应用、观察和总结，对目前全国梨树常用的9种树形在云南实际应用中表现出来的优点和缺点，分别进行概述和评论。提出了选用树形应与所栽品种、栽植密度和园地环境紧密结合，并与土肥水管理和病虫防治等有机协调，才能收到丰产稳产、优质高效和树壮寿长的效果。     

Antibody seroprevalences against rabies in dogs vaccinated under field conditions in Bolivia

Bolivia currently has one of the highest numbers of cases for human and canine rabies and is thus clue to the elimination process. The objective of the present study was to assess antibody seroprevalences against rabies in dogs vaccinated under field conditions and other factors that might influence the success of the on-going rabies control programmes in an endemic area of the disease, Santa Cruz de la Sierra, Bolivia. All 240 study animals, selected using area-stratified random sampling, were investigated in April 2007. Test prevalences were adjusted for the imperfect test characteristics using the Rogan–Gladen estimator (deterministic and stochastic functions) and Bayesian inference. Ninety-four of the tested 240 vaccinated dogs were classified as test-positive for rabies-specific antibodies. With regard to adjusted overall antibody seroprevalence, Bayesian true prevalence estimates (41%, 95% CI: 37–46%) were lower than both of the Rogan–Gladen estimates. The effect of various epidemiological factors on post-vaccination response was also assessed.     

3种土壤消毒剂对芹菜根腐病的田间防效

在大田试验条件下,比较了98%棉隆微粒剂、35%威百亩水剂、氰氨化钙土壤净化剂对芹菜根腐病的防治效果。结果表明:3种土壤消毒剂均对芹菜根腐病有一定的防效,发病率和病情指数均显著或极显著低于空白对照;98%棉隆微粒剂、氰氨化钙土壤净化剂、35%威百亩水剂的田间防效分别为68.03%、57.98%、35.60%,比对照分别增产35.19%、28.43%、13.20%,98%棉隆微粒剂可作为防治芹菜根腐病的首选药剂。     

Effects of rhTGF-β1 and TGF-β1 gene transfection on the proliferation of cultured rabbit corneal endothelial cells in vitro

AIM: To investigate the effects of rhTGF-β₁ and TGF-β₁ gene transfection on the proliferation of cultured rabbit corneal endothelial cells in vitro. METHODS: Cell growth induced by various concentrations of rhTGF-β₁ was determined by MTT proliferation assay. Under the induction of liposomes, recombinant pSecTag2-TGF-β₁MP vectors were transferred into the corneal endothelial cells. Morphological changes of transfected cells were observed by HE staining. The expression levels of TGF-β₁ were assessed by ELISA. Cell cycle analysis was assessed by flow cytometry. DNA fragment analysis was used to confirm the presence of apoptosis. RESULTS: rhTGF-β₁ in concentrations of 5-20 μg/L showed a significant suppressive effect on the proliferation of corneal endothelial cells, 0.5-1 μg/L had no effect, 0.05-0.1 μg/L facilitated cell growth, as compared with negative controls. The morphous of transfected corneal cells had no significant abnormality compared with normal cells. According to the result of ELISA, the concentration of TGF-β₁ in the supernatant was calculated to be (98±3) ng/L. Flow cytometry assay showed that S and G₂/M phase of transfected cells decreased significantly compared with that of control group, but the cell cycle recovered normally after adding 10 μg/L EGF into the culture medium. Agarose electrophoresis didn′t show marked ladders in transfected group. CONCLUSION: Effects of rhTGF-β₁ on the proliferation of corneal endothelial cells are different with various concentrations. TGF-β₁ gene transfection shows suppressive effect on the proliferation of cultured corneal endothelial cells, but does not induce cell apoptosis. EGF is the antagonist of this suppressive effect.     

Retinoid X receptor agonist inhibits TGF-β1-induced collagen synthesis in cardiac fibroblasts by repressing Smad2 activation

AIM: To investigate the effect of activation of retinoid X receptor (RXR) on transforming growth factor β1 (TGF-β1) induced collagen synthesis under hypoxic environment in rat cardiac fibroblasts (CFs) and underlying molecular mechanisms. METHODS: CFs were cultured using myocardial tissue with dry method. Hypoxic environment was established for CFs by continuous nitrogen supplement. Type I and type III collagens in supernatants were detected by ELISA. Nuclear and cytoplasmic extractions were prepared using NE-PER nuclear and cytoplasmic extraction reagents. The protein levels of Smad2 and p-Smad2 were determined by Western blot and immunocytochemical staining. RESULTS: Under hypoxic condition, TGF-β1 (0.01~10 μg/L) increased the synthesis of type I and type III collagens in a dose-dependent manner in the CFs. At the concentration of 5 μg/L, the synthesis of collagen I and III was significantly increased as compared with control group (P<0.01). RXR agonist 9-cis-retinoic acid (9-cis-RA; 10^-9~10^-6mol/L) decreased TGF-β1 (5 μg/L)-induced synthesis of type I and III collagens in a dose-dependent manner in the CFs under hypoxic condition. The synthesis of type I and type III collagens was significantly inhibited by 9-cis-RA (P<0.01). Smad2 inhibitor (20 nmol/L) showed similar inhibitory effect on the synthesis of type I and III collagens induced by TGF-β1 under hypoxic condition. Compared with TGF-β1 intervention group, the cytoplasmic level of p-Smad2 in the CFs was significantly increased in TGF-β1+9-cis-RA group, but the nuclear p-Smad2 level was significantly decreased (P<0.05). CONCLUSION: Retinoid X receptor agonist 9-cis-RA inhibits TGF-β1-induced synthesis of type I and type III collagens in the CFs by repressing p-Smad2 nuclear translocation under hypoxic condition.     

Spatial analysis of roadside Acacia populations on a road network using the network K-function

Spatial patterning of plant distributions has long been recognised as being important in understanding underlying ecological processes. Ripley’s K-function is a frequently used method for studying the spatial pattern of mapped point data in ecology. However, application of this method to point patterns on road networks is inappropriate, as the K-function assumes an infinite homogenous environment in calculating Euclidean distances. A new technique for analysing the distribution of points on a network has been developed, called the network K-function (for univariate analysis) and network cross K-function (for bivariate analysis). To investigate its applicability for ecological data-sets, this method was applied to point location data for roadside populations of three Acacia species in a fragmented agricultural landscape of south-eastern Australia. Kernel estimations of the observed density of spatial point patterns for each species showed strong spatial heterogeneity. Combined univariate and bivariate network K-function analyses confirmed significant clustering of populations at various scales, and spatial patterns of Acacia decora suggests that roadworks activities may have a stronger controlling influence than environmental determinants on population dynamics. The network K-function method will become a useful statistical tool for the analyses of ecological data along roads, field margins, streams and other networks.This revised version was published online in May 2005 with corrections to the Cover Date.     

Relationship between TGF β1 expression and apoptosis in hepatocytes during acute hemorrhagic necrotic pancreatitis

AIM: To observe the expression of TGF β1 in hepatocytes during acute hemorrhagic and necrotic pancreatitis (AHNP) and to study the relationship between TGF β1 and apoptosis in hepatocytes. METHODS: AHNP was induced in 40 rats weighting 260-280 g by intraductal administration of 5% sodium taurocholate. The pathologic morphologic changes of liver and pancreas were observed under light microscope. The hepatocyte apoptosis was examined through TdT (terminal deoxynucleotidyl transferase) mediated dUTP nick end labeling (TUNEL) and the expression of TGF β1 in hepatocytes was analyzed through immunohistochemistry. RESULTS: The liver injuries were found at 3 h after the inducement. These changes were aggravated with the development of the disease. The apoptotic hepatocytes were found after 3 h (P<0.05), and TGF β1 expressed in liver cells was observed at the same time (P<0.05). Both became more and more obvious with the development. CONCLUSION: AHNP can induce TGF β1 expression and apoptosis in hepatocytes, TGF β1 expression is correlation with hepatocyte apoptosis.     

The study on the relationship between transforming growth factor-β1 and lung carcinoma

AIM: To explore the relationship between the expression of transforming growth factor-β1 (TGF-β1) and the pathogenesis of lung carcinoma, and the influence of radiotherapy on plasma TGF-β1 level of patients with lung carcinoma. METHODS: By immunohistochemical method, the expression of TGF-β1 was examined. An enzyme-linked immunoadsorbent assay (ELISA) was used to quantify the plasma TGF-β1 levels in different time as before radiotherapy, at the end of radiotherapy, and at the time of follow-up 6 months after radiotherapy, respectively. The changes of quantity of TGF-β1 in different time above were analysed statistically. RESULTS: There was a significant increase in TGF-β1 expression in the carcinoma compared with normal lung tissue. The mean TGF-β1 level in the 39 lung carcinoma patients before radiotherapy was (11.0±1.5) μg/L, which was significantly higher than control group (3.8±0.2 μg/L) (P＜0.05); but the plasma TGF-β1 level after radiotherapy was significantly lower (5.6±0.5 μg/L) compared with the level before radiotherapy (P＜0.05), and there was not significant differences compared with control group (P＞0.05). At the time of follow-up 6 months, the patients of lung carcinoma had a significantly higher plasma TGF-β1 level (11.3±1.2 μg/L) compared with the level at the end of radiotherapy (P＜0.05), but there was not significant differences compared with before radiotherapy (P＞0.05). Not significant difference was found in TGF-β1 levels among different histologic types. CONCLUSION: These data demonstrated that TGF-β1 was associated with the pathogenesis of lung carcinoma, and it may be a useful tumor marker in patients with lung carcinoma.