Neutrophil function in the dog: shape change and response to a synthetic tripeptide   总被引：1，自引：0，他引：1  

J E Stickle  D K Kwan  C W Smith 《American journal of veterinary research》1985,46(1):225-228

Isolated dog neutrophils exposed to known chemotactic factors assumed a bipolar configuration in suspension. This response was initiated within 2 minutes with a gradual return to spherical shape. The rate of return to sphere was positively correlated with the dose of stimulant. Dog neutrophils exposed to N-formylmethionyl-leucyl-phenylalanine (fMLP) did not adapt to bipolar conformation and did not bind radiolabeled fMLP. These findings are consistent with other species (pig and cow) that also did not respond to fMLP.  相似文献   

Novel fibrinolytic enzyme in fermented shrimp paste, a traditional asian fermented seasoning     

Wong AH  Mine Y 《Journal of agricultural and food chemistry》2004,52(4):980-986

A novel fibrinolytic enzyme was purified from fermented shrimp paste, a popular seasoning used in Asian countries. The enzyme is a monomer with an apparent molecular weight of 18 kDa, and it is composed primarily of beta-sheet and random coils. The N-terminal amino acid sequence was determined to be DPYEEPGPCENLQVA. It is a neutral protease with an optimal activity from pH 3 to 7. No inhibition was observed with PMSF, Pepstatin A, E64, and 1,10-phenanthroline, but the enzyme was slightly inhibited by EDTA and Cu(2+). It was relatively specific to fibrin or fibrinogen as a protein substrate, yet it hydrolyzed none of the plasma proteins in the studies. In vitro, the enzyme was resistant to pepsin and trypsin digestion. It also had an anticoagulant activity measured with activated partial thrombin time and prothrombin time tests. The novel fibrinolytic enzyme derived from traditional Asian foods is useful for thrombolytic therapy. In addition, this enzyme has a significant potential for food fortification and nutraceutical applications, such that its use could effectively prevent cardiovascular diseases.  相似文献   

Cu2+和Pb2+对石蚕蛾幼虫的急毒性研究     

林啟福  陈海峰  Billy K.Y.Kwan  邹莹  李秀枝  王玉军 《安徽农业科学》2017,45(18)

[目的]研究Cu~(2+)和Pb~(2+)对石蚕蛾幼虫的急毒性效应和安全浓度。[方法]从广西十万大山保护区采集石蚕蛾(Stenopsyche marmorata)幼虫,采用静水生物毒性试验法进行重金属离子Cu~(2+)和Pb~(2+)对其的急毒性试验。采用概率单位法分别计算Cu~(2+)和Pb~(2+)对石蚕蛾幼虫的半致死浓度和安全浓度。[结果]Cu~(2+)对石蚕蛾幼虫的24、48、72、96 h的半致死浓度(LC50)分别为123.651、112.975、84.536和70.509 mg/L,Pb~(2+)对石蚕蛾幼虫的24、48、72、96 h的半致死浓度(LC50)分别为49.138、41.878、30.735和29.245 mg/L。Cu~(2+)和Pb~(2+)对石蚕蛾幼虫的安全浓度分别为7.051和2.925 mg/L。[结论]研究结果可为将石蚕蛾幼虫用作水体重金属污染指示生物提供科学依据。  相似文献   

Phylogenetic Analysis of Astrovirus and Kobuvirus in Korean Dogs     

Sarah CHOI  Seong-In LIM  Yong Kwan KIM  Yoon-Young CHO  Jae-Young SONG  Dong-Jun AN 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(8):1141-1145

  相似文献   

Effect of Leptin on In Vivo Goat Embryo Production     

AM Batista  WA Gomes  CCD Carvalho  PLJ Monteiro Jr  FLM Silva  FC Almeida  PC Soares  GF Carneiro  MMP Guerra 《Reproduction in domestic animals》2014,49(3):476-480

The aim of this study was to evaluate the effect of leptin administration during superovulation on in vivo goat embryo production. Ten mature does were superovulated with 133 mg follicle‐stimulating hormone (FSH) i.m. in six descending doses at 12‐h intervals. The goats received 4.8 μg/kg human recombinant leptin s.c. (leptin group, n = 5) or phosphate‐buffered saline (PBS) (control group, n = 5) with the first and second FSH doses. The does were mated and subjected to embryo collection by transcervical technique 6 days later. The total number of cells per embryo and the number of cells with fragmented DNA were assessed in selected blastocysts by combining Hoechst 33342 and terminal dUTP nick‐end labelling (TUNEL) staining. Plasma concentrations of oestradiol (E₂) and progesterone (P₄) were determined by electrochemiluminescence from the day of FSH treatment, on the day of superovulatory oestrus and on the day before embryo collection. Compared with the control group, the does that received leptin had a higher number of transferable embryos (p < 0.005), fewer embryos classified as degenerated (p < 0.001) and fewer TUNEL‐positive cells/blastocyst (p < 0.001). The number of transferable embryos was positively correlated with E₂ concentrations on day of oestrus (r = 0.562; p < 0.01) and P₄ concentrations on the day of embryo collection (r = 0.912; p < 0.001). We concluded that in vivo leptin administration during FSH treatment improved embryo quality and affected ovarian steroidogenesis in superovulated goats.  相似文献   

Effects of diet and sediment type on survival, growth and moulting of juvenile tiger crab, Orithyia sinica L.     

Jung-Hoon Jee  Ja-Geun Koo  Yoo-Hwa Keum  Joon-Suk Kang  Kwan H A Park  & Ju-Chan Kang 《Aquaculture Research》2007,38(1):26-35

This study investigated the effects of different types of diet and sediment on the growth parameters of juvenile tiger crab Orithyia sinica under laboratory conditions, focusing on survival, growth and moulting. In the first set of experiments, juvenile tiger crabs were reared with five different types of sediment, i.e., soft sand, coarse sand, soft sand mixed with coarse sand, mud or bare bottom. Soft sand resulted in not only the highest survival rate of 78% but also the best rate of growth and feed intake. Crabs reared with a mud substrate showed the worst results in these parameters. The intermoult period, however, was not affected by sediment types. In the second set of experiments, crabs were fed different types of diet to determine their effects on the same growth parameters. Diets were composed of different combinations with Manila clam (Ruditapes philippinarum), brine shrimp (Artemia nauplii), microencapsulated feeds and marine diatom (Chaetoceros gracilis). Survival and growth in crabs fed Manila clam as a diet component were significantly higher than in those on other diets. The highest survival and growth were achieved with a diet that included all four components. These results provide valuable information on the appropriate bottom substrates and diet types necessary for artificial mass culture of the tiger crab.  相似文献   

Thermal and mechanical properties of modified CaCO3 filled poly (ethylene terephthalate) nanocomposites     

Chang Soo Lee  Kwan Han Yoon  Jae Cheol Park  Hong-Un Kim  Young-Bin Park 《Fibers and Polymers》2014,15(7):1493-1499

Poly(ethylene terephthalate) (PET)/CaCO₃ and PET/modified-CaCO₃ (m-CaCO₃) nanocomposites were prepared by melt blending. The morphology indicated that m-CaCO₃ produced by reacting sodium oxalate and calcium chloride, was well dispersed in PET matrix and showed good interfacial interaction with PET compared to CaCO₃. No significant differences in the thermal properties such as, glass transition, melting and degradation temperatures, of the nanocomposites were observed. The thermal shrinkage of PET at 120 °C was 10.8 %, while those of PET/CaCO₃ and PET/m-CaCO₃ nanocomposites were 2.9–5.2 % and 1.2–2.8 %, respectively depending on filler content. The tensile strength of PET/CaCO₃ nanocomposite decreased with CaCO₃ loading, whereas that of PET/m-CaCO₃ nanocomposites at 0.5 wt% loading showed a 17 % improvement as compared to neat PET. The storage modulus at 120 °C increased from 1660 MPa for PET to 2350 MPa for PET/CaCO₃ nanocomposite at 3 wt% loading, and 3230 MPa for PET/m-CaCO₃ nanocomposite at 1 wt% loading.  相似文献   

Monitoring distances travelled by horses using GPS tracking collars     

BA Hampson  JM Morton  PC Mills  MG Trotter  DW Lamb  CC Pollitt 《Australian veterinary journal》2010,88(5):176-181

Objective The aims of this work were to (1) develop a low-cost equine movement tracking collar based on readily available components, (2) conduct preliminary studies assessing the effects of both paddock size and internal fence design on the movements of domestic horses, with and without foals at foot, and (3) describe distances moved by mares and their foals. Additional monitoring of free-ranging feral horses was conducted to allow preliminary comparisons with the movement of confined domestic horses. Procedures A lightweight global positioning system (GPS) data logger modified from a personal/vehicle tracker and mounted on a collar was used to monitor the movement of domestic horses in a range of paddock sizes and internal fence designs for 6.5-day periods. Results In the paddocks used (0.8–16 ha), groups of domestic horses exhibited a logarithmic response in mean daily distance travelled as a function of increasing paddock size, tending asymptotically towards approximately 7.5 km/day. The distance moved by newborn foals was similar to their dams, with total distance travelled also dependent on paddock size. Without altering available paddock area, paddock design, with the exception of a spiral design, did not significantly affect mean daily distance travelled. Feral horses (17.9 km/day) travelled substantially greater mean daily distances than domestic horses (7.2 km/day in 16-ha paddock), even when allowing for larger paddock size. Conclusions Horses kept in stables or small yards and paddocks are quite sedentary in comparison with their feral relatives. For a given paddock area, most designs did not significantly affect mean daily distance travelled.  相似文献   

Sequence variants in SLITRK1 are associated with Tourette's syndrome   总被引：1，自引：0，他引：1  

Abelson JF  Kwan KY  O'Roak BJ  Baek DY  Stillman AA  Morgan TM  Mathews CA  Pauls DL  Rasin MR  Gunel M  Davis NR  Ercan-Sencicek AG  Guez DH  Spertus JA  Leckman JF  Dure LS  Kurlan R  Singer HS  Gilbert DL  Farhi A  Louvi A  Lifton RP  Sestan N  State MW 《Science (New York, N.Y.)》2005,310(5746):317-320

Tourette's syndrome (TS) is a genetically influenced developmental neuropsychiatric disorder characterized by chronic vocal and motor tics. We studied Slit and Trk-like 1 (SLITRK1) as a candidate gene on chromosome 13q31.1 because of its proximity to a de novo chromosomal inversion in a child with TS. Among 174 unrelated probands, we identified a frameshift mutation and two independent occurrences of the identical variant in the binding site for microRNA hsa-miR-189. These variants were absent from 3600 control chromosomes. SLITRK1 mRNA and hsa-miR-189 showed an overlapping expression pattern in brain regions previously implicated in TS. Wild-type SLITRK1, but not the frameshift mutant, enhanced dendritic growth in primary neuronal cultures. Collectively, these findings support the association of rare SLITRK1 sequence variants with TS.  相似文献   

Predatory Dinosaurs from the Sahara and Late Cretaceous Faunal Differentiation     

PC Sereno  DB Dutheil  M Iarochene  HCE Larsson  GH Lyon  PM Magwene  CA Sidor  DJ Varricchio  JA Wilson 《Science (New York, N.Y.)》1996,272(5264):986-991

Late Cretaceous (Cenomanian) fossils discovered in the Kem Kem region of Morocco include large predatory dinosaurs that inhabited Africa as it drifted into geographic isolation. One, represented by a skull approximately 1.6 meters in length, is an advanced allosauroid referable to the African genus Carcharodontosaurus. Another, represented by a partial skeleton with slender proportions, is a new basal coelurosaur closely resembling the Egyptian genus Bahariasaurus. Comparisons with Cretaceous theropods from other continents reveal a previously unrecognized global radiation of carcharodontosaurid predators. Substantial geographic differentiation of dinosaurian faunas in response to continental drift appears to have arisen abruptly at the beginning of the Late Cretaceous.  相似文献