用RAPD分析和DNA指纹鉴别玉米小斑病菌O、C、T三个小种

目前通过病理学鉴定已发现玉米小斑病菌存在分别对玉米雄性不育T型、C型细胞质专化侵染的T小种和C小种(无细胞质专化致病性的相应称为O小种)。为了建立快速鉴别、监测O、C、T三个小种的技术,我们使用了近来建立的基于以带有任意序列单一寡核苷酸引物的DNA随机片段扩增技术进行了三个     

Epidemiology of feline leukaemia and feline immunodeficiency virus infections in the Czech Republic

Commercial serological sets were used for the examination of 727 cats kept in larger towns of the Czech Republic. FeLV antigen and antibodies to FIV were demonstrated in 96 (13.2%) and 42 (5.8%) of the animals, respectively. Seven (0.96%) animals were positive for both FeLV and FIV. Most of the FeLV and/or FIV positive patients were intact rambling males aged 1-4 years. Chronic gastrointestinal and respiratory diseases were found in 54.2% and 43.8% of the FeLV-positive patients, respectively. Chronic urinary tract diseases and generalized lymphadenopathy were found in 47.6% and 45.2% of the FIV-positive patients, respectively. The results of this first survey in the Czech Republic have shown prevalence values and clinical patterns similar to those reported formerly from other European countries.     

Biological Control of Bipolaris sorokiniana on Tall Fescue by Stenotrophomonas maltophilia Strain C3

ABSTRACT Stenotrophomonas maltophilia strain C3 was evaluated for control of leaf spot on tall fescue (Festuca arundinacea) caused by Bipolaris sorokiniana. In growth chamber experiments, C3 inhibited conidial germination on leaf surfaces and reduced lesion frequency and percent diseased leaf area compared with nontreated controls. The amount of leaf spot suppression was related to the C3 dose applied. The highest dose tested, 10(9) CFU/ml, prevented nearly all B. sorokiniana conidia from germinating on treated leaf surfaces and provided nearly complete suppression of lesion development. When colloidal chitin was added to C3 cell suspensions of 10(7) or 10(8) CFU/ml, biocontrol efficacy was significantly increased over C3 applied alone, whereas addition of chitin to a C3 cell suspension of 10(9) CFU/ml had no effect. In field experiments, application of C3 to tall fescue turf resulted in significant reductions in infection frequency and disease severity compared with nontreated controls. Strain C3 applied at 10(9) CFU/ml was more effective than C3 applied at 10(7) CFU/ml, and amendment of the lower dose with colloidal chitin enhanced its efficacy. Populations sizes of C3 established on foliage in a growth chamber and in the field were directly related to dose applied. Chitin amendments did not affect C3 population size.     

Erythroid progenitor cells from pig bone marrow and peripheral blood

With the intention of using the pig as a large animal model in haematopoietic research, a clonal assay in methylcellulose was developed and the optimal conditions for raising erythroid progenitors from adult pig bone marrow (BM) and peripheral blood (PB) have been established. Progenitor cells were stimulated to proliferate and differentiate in vitro by growth factors containing leucocyte condition medium (LCM), and with recombinant human erythropoietin (rhEpo). The number of PB BFU-E (burst forming units - erythroid) directly depended on the concentration of LCM, but BM BFU-E were not dependent on LCM. Both CFU-E (colony forming units - erythroid) and BFU-E were rhEpo dependent. Despite relatively high but expected individual variations, the mean number of colonies, as well as the functional characteristics of progenitor cells investigated, were similar to those of miniature pigs and some other mammals.     

Effect of different daily doses of gizzerosine on the serum 1,25-dihydroxycholecalciferol concentration in laying hens

Five groups of laying hens were treated with different gizzerosine doses (0, 2.5; 5.0; 7.5; 10.0 mg/kg/body weight of gizzerosine) daily over a 21-day period to determine the serum concentrations of 1.25-dihydroxycholecalciferol (1,25(OH)2D), total calcium, inorganic phosphorus and magnesium. Blood samples were taken on days 7, 14, and 21 of the experiment. The concentration of 1,25(OH)2D remained unchanged after day 7 in the gizzerosine-treated birds compared to the control group. After 14 days, it was significantly lower in the birds receiving. gizzerosine, compared with the control group. On day 21, 1,25(OH2)D concentrations were also significantly decreased in all 4 gizzerosine-treated groups compared with the control hens. The serum total calcium, inorganic phosphorus and total magnesium concentrations varied significantly, but irregularly, during the period of the study.     

The effects of bovine respiratory syncytial on normal ovine lymphocyte responses to mitogens or antigens in vitro

In the present study peripheral blod mononuclear cells (MNC) obtained from normal uninfected lambs were used to study the possible effects of bovine respiratory syncytial virus (BRSV) on lymphocyte responses to the mitogens, phytohaemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) in vitro. Live BRSV had a depressive effect on the proliferative responses of normal MNC to PHA, Con A and PWM. Inactivated BRSV and a commercial preparation of prostaglandin E2 were also found to depress the proliferative responses of normal ovine MNC to PHA but recombinant tumour necrosis factor-alpha (TNF-alpha) had no such effect. Serum samples obtained from BRSV-infected lambs contained substances inhibitory to PHA-driven lymphocyte blastogenesis. Memory blastogenic responses to border disease virus (BDV) of lymyphocytes obtained from lambs previously primed with BDV were significantly reduced when lymphocytes were exposed to infectious BRSV.     

桃叶治牲畜化脓創

广西梧州市农場印度摩拉水牛,雄性,因打架,胸部左側严重负伤曆鴨T未及时报告,待发現时伤口已肿大化脓,內已生蛆丝谥本?公分,基部6公分,恶臭。处理方法:先用高錳酸鉀溶液冲洗伤口,除去蛆虫,后用桃叶若干,石灰少許,共同捣碎,填塞于伤口內,到填滿为止,外塗凡士林(仅防蝇叮虫咬),只用药一次,数日后伤口痊癒。     

Effects of transcutaneous electrical nerve stimulation on the fatty acid profile of rabbit longissimus dorsi muscle (preliminary report)

This study was designed to investigate whether transcutaneous electrical nerve stimulation (TENS) of the longissimus dorsi muscle (MLD) of rabbits induces specific proportional changes in the muscle fatty acid composition. Ten 4-week-old Pannon White rabbits were exposed to TENS treatment two times a day, with the following settings: 30 Hz, 20 micros impulse length, 10 mA, 2 x 20 min. After a treatment period of 50 days rabbits were slaughtered and the fatty acid composition of the MLD was determined by gas chromatography. The TENS treatment increased the proportions of linoleic (C18:2 n-6), linolenic (C18:3 n-3) and gondoic acids (C20:1 n-9), compared with the control group. The level of palmitic (C16:0), stearic (C18:0), oleic (C18:1 n-9) and eicosapentaenoic (C20:5 n-3) acids significantly decreased. The proportion of total unsaturated fatty acids significantly increased. On the basis of the results obtained, TENS may have similar effects on the muscle fatty acid profile like physical training. Based on the supposal that the composition of membrane structure was also affected, the electrical stimulation of muscles may have further consequences, e.g. on membrane properties.     

Effects of growth factors (EGF,PDGF-BB and TGF-beta 1) on cultured equine epithelial cells and keratocytes: implications for wound healing

Objective The physiologic mechanisms involving growth factors, including PDGF‐BB, EGF, and TGF‐β1, as potent mediators of fibroblasts and epithelial cells in corneal wound healing remain unknown. The goal of this study was to determine culture methods for equine epithelial cells and keratocytes and to investigate how exogenous growth factors influence proliferation of both cell types. Procedures Cell cultures were established from healthy corneas harvested from horses immediately following euthanasia and maintained using standard tissue culture protocols. To determine the effects of PDGF‐BB, EGF, TGF‐β1, keratocytes (1 × 10⁵/well) and epithelial cells (2 × 10⁵/well) were each cultured in 12 well plates and exposed separately to the growth factors. The cells were exposed to concentrations of EGF between 0 and 50 ng/mL; PDGF‐BB between 0 and 75 ng/mL; and TGF‐β1 between 0 and 10 ng/mL. Cell proliferation was measured using ³H‐thymidine assay and differences in growth determined using anova and Tukey's HSD test (P < 0.05). Results Epithelial cell and keratocyte cultures were successfully established. EGF maximally stimulated keratocyte and epithelial cells at 25 ng/mL and 5 ng/mL, respectively. PDGF‐BB maximally stimulated keratocytes and epithelial cells at 50 ng/mL and 5 ng/mL, respectively. TGF‐β1 inhibited keratocytes at 5 ng/mL and 10 ng/mL, and epithelial cells at 1 ng/mL and 2 ng/mL. Conclusions Methods were established to maintain epithelial cells and keratocytes in vitro. PDGF‐BB and EGF stimulate, while TGF‐β1 inhibits the proliferation of epithelial cells and keratocytes. These growth factors may play a role in maintenance and repair of the equine cornea.