Cytotoxic Effects of Loperamide Hydrochloride on Canine Cancer Cells     

Rebecca Cohen REGAN  Robert Michael GOGAL  Jr  James Perry BARBER  Richard Cary TUCKFIELD  Elizabeth Wynne HOWERTH  Jessica Ann LAWRENCE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(12):1563-1568

Loperamide is a peripheral opiate agonist that can cause apoptosis and G2/M arrest in human cancer cell lines and may sensitize cells to chemotherapy. The objectives of this study were to investigate the effects of loperamide on viability, apoptosis and cell cycle kinetics in canine cancer cells and to establish whether the drug sensitizes cells to doxorubicin. Cell viability was assessed using Alamar Blue. Cell death and cell cycle were studied using flow cytometry with 7-Aminoactinomycin-D (7-AAD) and propidium iodide (PI), respectively. Loperamide decreased cell viability in a dose-dependent fashion and was most effective against canine osteosarcoma cells. In all cell lines, it induced a dose and time dependent apoptosis and resulted in accumulation in G0/G1. When co-incubated with doxorubicin, loperamide induced a synergistic cell kill in canine carcinoma cells. Investigation is warranted into the role of loperamide in the treatment of canine cancer.  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   

Trends in carbon flux to seabirds in the Peruvian upwelling system: effects of wind and fisheries on population regulation   总被引：4，自引：0，他引：4  

J. Jahncke  D. M. Checkley  Jr    G. L. Hunt  Jr 《Fisheries Oceanography》2004,13(3):208-223

We hypothesized that change in the annual population size of guano‐producing seabirds (cormorant, Phalacrocorax bougainvillii; booby, Sula variegata; pelican, Pelecanus thagus) is a response to changes in primary and secondary production of the Peruvian upwelling system. We tested this hypothesis by modeling nitrate input through upwelling to the upper layers of the ocean off Peru between 6° and 14°S using data on wind stress and sea surface temperature. The model predicted the amount of carbon fixed by primary production each year from 1925 to 2000, which was then apportioned to the Peruvian anchovy (Engraulis ringens) biomass and ultimately to the seabird population and the anchovy fishery, the largest single‐species fishery on Earth. The model predicted a marked increase in primary production as a consequence of increasing wind stress. It overestimated the anchovy biomass after the collapse of the fishery in 1972, but closely predicted the growth of seabird populations from 1925 to the mid‐1960s, and their decline thereafter, explaining about 94% of the variation in seabird numbers from 1925 to 2000. The model indicates the seabirds consumed 14.4% of the available anchovies and, thus, that seabirds consumed 2.3% of the new production, before the development of the anchovy fishery, and only 2.2% of the available anchovies and 0.3% of the new production after the development of the fishery. The model results clarify the roles that environmental and anthropogenic factors may have had in regulating the guano‐producing seabird populations. It indicates that the growth of seabird populations from 1925 to 1955 was likely a response to increased productivity of the Peruvian upwelling system and that the subsequent drastic decline in seabird abundance was likely due to competition for food with the fishery, which caught ～85% of the anchovies, which otherwise would have been available for the seabirds. This model also shows that an increase in oceanic primary production promotes reproductive success and population growth in higher trophic level organisms.  相似文献   

Influence of β-hydroxy-β-methylbutyrate on nonspecific humoral defense mechanisms and protection against furunculosis in pikeperch (Sander lucioperca)     

Andrzej K Siwicki  Zdzis&#;aw Zak&#;&#;  John C Fuller Jr    Steven Nissen  Sylwia Trapkowska  Edward G&#;&#;bski  Agata Kowalska  Krzytof Kazu&#;  & El&#;bieta Terech-Majewska 《Aquaculture Research》2006,37(2):127-131

Studies have shown that in both in vitro and in vivo tests, β‐hydroxy‐β‐methylbutyrate (HMB) increases the nonspecific cellular and humoral immune response and protection against diseases in animals. The present study examines the influence of HMB on nonspecific humoral defense mechanisms and protection against furunculosis in pikeperch (Sander lucioperca). β‐hydroxy‐β‐methylbutyrate was fed in a pelleted ration of 50 mg kg^?1 feed day^?1 for 4 weeks. Blood was drawn from 12 HMB‐fed and control‐fed pikeperch. The lysozyme and ceruloplasmin activities in the plasma, total immunoglobulin (Ig) levels, and total serum protein were analysed prior to and then after 2 and 4 weeks of HMB ingestion. After 4 weeks of HMB ingestion, a challenge test was performed by injecting the fish with live pathogenic Aeromonas salmonicida bacteria. β‐hydroxy‐β‐methylbutyrate at a dose of 50 mg kg^?1 feed resulted in a statistically significant (P<0.05) increase in the lysozyme activity of the plasma, total Ig, and serum protein levels. Additionally, reduced mortality (40%) after the in vivo challenge with pathogenic A. salmonicida suggested that HMB‐activated nonspecific protection against furunculosis in pikeperch.  相似文献   

Comparative Economics of Four Aquaculture Species Under Monoculture and Polyculture Production in Guam   总被引：1，自引：0，他引：1  

William J.  Fitzgerald  Jr. 《Journal of the World Aquaculture Society》1988,19(3):132-142

Financial analysis, which included breakeven, net present value, internal rate of return, present value index, payback period and financial ratios, was carried out on data from three aquaculture farms located on Guam. The analysis included four primary species, Macrobrachium rosenbergii, Chanos chanos, Clarias batrachus , and a hybrid Oreochromis mossambicus × O . niloticus , and two culture methods, monoculture and polyculture. Asian catfish, Clorias batrachus , monoculture showed the greatest capital return. The use of NPV, PVI, IRR, and payback period as decision criteria also resulted in the selection of Asian catfish monoculture from the alternative species and culture methods considered. Tilapia polyculture had the lowest return on investment (less than 1%) and required 92% of the total production to reach the breakeven point. The application of the analysis methods presented provide a means for management to reduce financial risks and make informed choices between alternative strategies.  相似文献   

Effects of cryptic mortality and the hidden costs of using length limits in fishery management   总被引：4，自引：0，他引：4  

Lewis G Coggins Jr    Matthew J Catalano  Micheal S Allen  William E Pine III  & Carl J Walters 《Fish and Fisheries》2007,8(3):196-210

Fishery collapses cause substantial economic and ecological harm, but common management actions often fail to prevent overfishing. Minimum length limits are perhaps the most common fishing regulation used in both commercial and recreational fisheries, but their conservation benefits can be influenced by discard mortality of fish caught and released below the legal length. We constructed a computer model to evaluate how discard mortality could influence the conservation utility of minimum length regulations. We evaluated policy performance across two disparate fish life‐history types: short‐lived high‐productivity (SLHP) and long‐lived low‐productivity (LLLP) species. For the life‐history types, fishing mortality rates and minimum length limits that we examined, length limits alone generally failed to achieve sustainability when discard mortality rate exceeded about 0.2 for SLHP species and 0.05 for LLLP species. At these levels of discard mortality, reductions in overall fishing mortality (e.g. lower fishing effort) were required to prevent recruitment overfishing if fishing mortality was high. Similarly, relatively low discard mortality rates (>0.05) rendered maximum yield unobtainable and caused a substantial shift in the shape of the yield response surfaces. An analysis of fishery efficiency showed that length limits caused the simulated fisheries to be much less efficient, potentially exposing the target species and ecosystem to increased negative effects of the fishing process. Our findings suggest that for overexploited fisheries with moderate‐to‐high discard mortality rates, reductions in fishing mortality will be required to meet management goals. Resource managers should carefully consider impacts of cryptic mortality sources (e.g. discard mortality) on fishery sustainability, especially in recreational fisheries where release rates are high and effort is increasing in many areas of the world.  相似文献   

Species concepts and speciation of fishes: concluding remarks     

Jay R Stauffer Jr    Patrick M Kocovsky  & Renea A Ruffing 《Fish and Fisheries》2002,3(3):230-232

The definition of the species category has stimulated more debate than perhaps any other topic in the biological sciences. There are currently more than 22 different species concepts and the debate continues on which concepts apply to all organisms, which concepts are operational and which concepts should be used in specific circumstances. The first major division of the types of concepts depends on whether one views species as constructs that exist for ordering biodiversity and information retrieval (i.e. classes), or views species as ontological individuals that exist in nature. If species are categories that can be defined, then theoretically, a single species can arise more than once in different places or at different times. If, on the other hand, species are individuals, then they are historical events, monophyletic and each species is unique.  相似文献   

Tolerance of Juvenile Flatfish Paralichthys orbignyanus to Acid Stress   总被引：1，自引：0，他引：1  

Wilson  Wasielesky  Jr. Adalto  Bianchini  Marcos H. S.  Santos Luis H.  Poersch 《Journal of the World Aquaculture Society》1997,28(2):202-204

Abstract.— The tolerance of juvenile flatfish Paralichthys orbignyanus to acid stress, was studied in 30-L plastic tanks using ten flatfishes (95 ± 13 g) per treatment. Water pH was monitored every 3 h and re-adjusted to the test pH using either HCl or NaOH. The photoperiod was fixed at 12L:12D, water temperature at 23 ± 0.8 C, and salinity at 30 ppt. Fish survival and ventilatory rate were monitored daily. At pH 4.0, we observed 100% mortality and ventilation rates different from controls. At pH 5.2, there was 100% survival even after 96 h. However, ventilation rate was higher than in controls. At pH equal or higher than 6.0, we observed 100% survival and normal ventilation rates. The estimated pH which would kill 50% of test organisms were: 4.51, 4.50 and 4.40 after 48, 72, and 96 h of experiment, respectively. These results show that juvenile flatfish are relatively tolerant to acid stress.  相似文献   

Method of rapid measurement for large samples of small aquatic organisms     

Yew-Hu Chien  James W. Avault  Jr. 《Aquacultural Engineering》1983,2(4):309-311

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Manipulations of Shrimp Embryos: A Viable Technique for the Removal of the Hatching Envelope   总被引：1，自引：0，他引：1  

John W.  Lynn Patricia S.  Glas  Philip L.  Hertzler Wallis H.  Clark  Jr.  Jeffrdy D.  Green 《Journal of the World Aquaculture Society》1993,24(1):1-5

The hatching envelope elevated around the spawned eggs of penaeoidean eggs presents a formidable barrier for manipulation of the embryo. By spawning eggs into seawater containing 3-amino-1,2,4-triazole and subsequently passing the eggs through Nitex screening approximately 45 min after spawning, the hatching envelope can be effectively removed with little or no damage to the embryos. The time and extent to which the envelope is removed can be varied. Embryos treated in this manner continue to develop and the method provides a new technique with which investigators can gain access to the surface of the egg or embryo.  相似文献