Localization of antigenic determinants in the polypeptide chains of collagen   总被引：6，自引：0，他引：6  

Michaeli D  Martin GR  Kettman J  Benjamini E  Leung DY  Blatt BA 《Science (New York, N.Y.)》1969,166(3912):1522-1524

After being injected with collagen from rat or guinea pig skin, rabbits form high titer, species-specific antibodies to collagen. Antibody is directed primarily against the alpha2 chain of collagen with little reaction with the alpha1 chain. The amino terminal peptide of cyanogen bromide cleavage of the alpha2 chain of guinea pig skin collagen, alpha2-CBl, effectively inhibited the antigen-antibody reaction, an indication that a major antigenic determinant of collagen is located at the amino terminal of the alpha2 chain.  相似文献   

CVMA Task Force on "education,licensing, and the expanding scope of veterinary practice"          下载免费PDF全文

Bailey J  Hagele WC  Leung D  Lofstedt J  Radostits OM  Sandals D 《The Canadian veterinary journal. La revue veterinaire canadienne》2002,43(11):845-854

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Phase I & Ib Trials of Murine Tyrosinase ± Human GM‐CSF DNA Vaccination in Dogs with Advanced Malignant Melanoma     

P. J.  Bergman †  M. A. Camps&#;Palau  J. A. McKnight  N. F. Leibman  C. A. Novosad  S. Brenn  S. N. Ettinger  M. M. Endicott  K. Finora  D. Craft  C. Leung  J. Liao  I. Riviere  A. E. Hohenhaus  A. Houghton  M. Perales  J. D. Wolchok 《Veterinary and comparative oncology》2005,3(1):35-36

Introduction:  Canine malignant melanoma (CMM) is an aggressive neoplasm treated with surgery and/or fractionated RT; however, metastatic disease is common and chemoresistant. Preclinical and clinical studies by our laboratory and others have shown that xenogeneic DNA vaccination with tyrosinase family members can produce immune responses resulting in tumor rejection or protection and prolongation of survival. The potency of DNA vaccines can be further enhanced by adding DNA encoding cytokine genes. We have shown in preclinical mouse models that GM‐CSF DNA enhances immune responses and tumor protection. These studies provided the impetus for murine tyrosinase (muTyr) ± human GM‐CSF (huGM‐CSF) DNA vaccination in CMM.
Materials & Methods:  Two groups of five dogs each with advanced (WHO stage II‐IV) CMM received four biweekly IM injections (100 ug or 500 ug, respectively/vaccination) of plasmid DNA encoding muTyr via the Biojector2000 jet delivery device. Subsequently, three groups of nine dogs each with advanced CMM received four biweekly IM injections of plasmid DNA encoding muTyr (50 ug), huGM‐CSF (3 dogs each at 100/400/800 ug) or both.
Results:  Minimal to mild pain was noted on vaccination and no toxicity or induction of autoimmunity was seen. The KM median survival time was 224 days (100/500 ug muTyr), 278 days (50 ug muTyr), 140 days (huGM‐CSF) and >265 days (muTyr & huGM‐CSF; 6 dogs still alive).
Conclusions:  The results of these trials demonstrate that xenogeneic DNA vaccination continues to be a safe and potentially therapeutic modality for CMM. These results also warrant further evaluation of this novel therapeutic in a Phase II setting.  相似文献   

Evaluation of P-glycoprotein expression in feline lymphoma and correlation with clinical outcome     

S. H. Brenn  S. S. Couto  D. M. Craft  C. Leung  P. J. Bergman 《Veterinary and comparative oncology》2008,6(3):201-211

P-glycoprotein (Pgp) is a transmembrane protein pump involved in drug resistance in canine and human lymphoma. There are no published clinical studies evaluating Pgp expression in feline lymphoma. The purpose of this study is to evaluate the level of Pgp expression in feline lymphoma and correlate it with clinical outcome. Two human Pgp monoclonal antibodies, C219 and C494, were used to detect Pgp expression in tissue samples from 63 cats with lymphoma. Demographic results appear comparable to recently published feline lymphoma studies. The Kaplan–Meier median remission and survival times were 164 and 571 days, respectively. Fourteen cats had positive expression of Pgp using MAb C219, and 40 were positive with C494. Variables statistically associated with survival included bone marrow involvement, stage, substage, and use of radiation therapy as a part of treatment. Pgp expression as assessed by MAb C219 and C494 is not predictive of remission or survival time in cats with lymphoma.  相似文献   

Effects of body weight, water temperature and ration size on ammonia excretion by the areolated grouper (Epinephelus areolatus) and mangrove snapper (Lutjanus argentimaculatus)     

K. M. Y. Leung  J. C. W. Chu  R. S. S. Wu 《Aquaculture (Amsterdam, Netherlands)》1999,170(3-4):215-227

The effects of body weight, water temperature and ration size on ammonia excretion rates of the areolated grouper Epinephelus areolatus and the mangrove snapper Lutjanus argentimaculatus were investigated. Under given experimental conditions, L. argentimaculatus had a higher weight-specific ammonia excretion rate than E. areolatus. Weight-specific ammonia excretion rates of fasted individuals of both species showed an inverse relationship with body weight (W, g wet wt.), but a positive relationship with water temperature (t, °C). The relationships for total ammonia nitrogen (TAN) were: E. areolatus: TAN (mg N kg⁻¹ d⁻¹)=21.4·exp^0.11t·W^−0.43 (r²=0.919, n=60); L. argentimaculatus: TAN (mg N kg⁻¹ d⁻¹)=121.5·exp^0.12t·W^−0.55 (r²=0.931, n=60). Following feeding, the weight-specific ammonia excretion rate of E. areolatus increased, peaked at 2 to 12 h (depending on temperature), and returned to pre-feeding levels within 24 h. A similar pattern was observed for L. argentimaculatus, with a peak of TAN excretion being found 6 to 12 h after feeding. Stepwise multiple regression analysis indicated that weight-specific TAN excretion rates of both species increased with increasing temperature and ration (R, percent body wt. d⁻¹): E. areolatus: TAN (mg N kg⁻¹ d⁻¹)=22.8·t−28.8·R−378.2 (r²=0.832, n=24); L. argentimaculatus: TAN (mg N kg⁻¹ d⁻¹)=22.9·t−25.4·R−216.4 (r²=0.611, n=24). The effect of body weight on weight-specific postprandial TAN excretion was not significant in either species (p>0.05). This study provides empirical data for estimating ammonia excretion of these two species under varying conditions. This has application for culture management.  相似文献   

Economic efficiency and optimum stocking densities in fish polyculture: an application of data envelopment analysis (DEA) to Chinese fish farms   总被引：2，自引：0，他引：2  

Khem R. Sharma  PingSun Leung  Hailiang Chen  Aaron Peterson 《Aquaculture (Amsterdam, Netherlands)》1999,180(3-4):207-221

Polyculture is commonly practiced in pond aquaculture where several fish species are reared together, creating a multi-output production structure. This study applied a nonparametric data envelopment analysis (DEA) technique for multiple outputs to: (1) measure economic or ‘revenue' efficiency and its technical and allocative components for a sample of Chinese polyculture fish farms; and (2) derive the optimum stocking densities for different fish species. The mean economic efficiency was estimated to be 0.74. Technical inefficiencies accounted for most of the production inefficiencies in Chinese fish farms. On average, farmers should increase grass carp and decrease black carp stocking rates. Smaller farms and those from the developed regions were found to be relatively more technically and economically efficient.  相似文献   

Student Opportunity: Short-Term Exposure to International Agriculture     

Ronald L. Phillips  Noel P. Magor  David Shires  Hei Leung  Susan R. McCouch  Duncan Macintosh 《Rice》2008,1(1):11-15

Opportunities abound to apply crop science to solving many of the world’s food problems. International agricultural research centers (IARCs) provide a window through which students can see the need for improved agricultural productivity and briefly experience the rewards of working on difficult but important issues. In today’s world of highly technical graduate education, students find it difficult to obtain exposure to international agriculture due to the extreme constraints on their time. Programs for students that provide a short-term exposure to IARC strategies can have long-term benefits for the student as well as the international center. A short-term student exchange program between a US university and the International Rice Research Institute (IRRI) and a special course on rice (research to production) offered at IRRI provide students with unique insights for averting food riots in the future. Details of these educational efforts are described in this paper.  相似文献   

Proteomic Analysis of the Venom of Jellyfishes Rhopilema esculentum and Sanderia malayensis     

Thomas C. N. Leung  Zhe Qu  Wenyan Nong  Jerome H. L. Hui  Sai Ming Ngai 《Marine drugs》2020,18(12)

Venomics, the study of biological venoms, could potentially provide a new source of therapeutic compounds, yet information on the venoms from marine organisms, including cnidarians (sea anemones, corals, and jellyfish), is limited. This study identified the putative toxins of two species of jellyfish—edible jellyfish Rhopilema esculentum Kishinouye, 1891, also known as flame jellyfish, and Amuska jellyfish Sanderia malayensis Goette, 1886. Utilizing nano-flow liquid chromatography tandem mass spectrometry (nLC–MS/MS), 3000 proteins were identified from the nematocysts in each of the above two jellyfish species. Forty and fifty-one putative toxins were identified in R. esculentum and S. malayensis, respectively, which were further classified into eight toxin families according to their predicted functions. Amongst the identified putative toxins, hemostasis-impairing toxins and proteases were found to be the most dominant members (>60%). The present study demonstrates the first proteomes of nematocysts from two jellyfish species with economic and environmental importance, and expands the foundation and understanding of cnidarian toxins.  相似文献   

Plant science. Controlling hormone action by subversion and deception     

Leung J 《Science (New York, N.Y.)》2012,335(6064):46-47

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Evolutionary trend of foot-and-mouth disease virus in Hong Kong     

Hui RK  Leung FC 《Veterinary microbiology》2012,159(1-2):221-229

Foot-and-mouth disease is an endemic animal disease in Hong Kong. In this study, a total of 70 clinical specimens were collected from locally infected pigs from 2001 to 2010. Phylogenetic analysis of VP1 sequences reveal that all Hong Kong FMDV serotype O isolates are classified into three lineages: HK-A and HK-B in Cathay topotype, and HK-C in SEA topotype. Regression analysis projects that the time of divergence from the most recent common ancestor of HK-A and HK-B are 1964 ± 12 and 1987 ± 9 years respectively. Although HK-B shares a common ancestor with strains that caused outbreak in Taiwan and Philippines, there is no consolidated evidence demonstrating the order of introduction events among these regions. HK-C lineage is the latest FMDV isolated in Hong Kong. This virus is likely adopted from bovine into porcine. As local pigs confer immunity mainly against Cathay topotype viruses, introduction of HK-C viruses have led into an unexpectedly high severity and rapid spreading rate of the disease. A systematic surveillance and communication network is essential to provide accurate information in controlling the pandemics.  相似文献