Ultrastructure of equine endothelial cells exposed to endotoxin and flunixin meglumine and equine neutrophils     

J J Turek  C H Lamar  J F Fessler  G D Bottoms 《American journal of veterinary research》1987,48(9):1363-1366

An in vitro system of cultured equine endothelial cells was evaluated as a model for endotoxin (ET) exposure in the horse. Primary cell lines from pulmonary vessels and aortas were cultured from tissues of 6 horses. Effects of ET alone with and without serum and in combination with the cyclo-oxygenase inhibitor flunixin meglumine and isolated equine neutrophils were evaluated by transmission electron microscopy. Cells plus serum were incubated with 10, 25, 50, or 100 micrograms of ET/ml of incubation medium for 1, 3, 8, or 24 hours. Cells without serum were cultured for 1 and 3 hours. Flunixin meglumine was used at a concentration of 20 micrograms/ml. Cells also were incubated in the presence of 1,000, 5,000, or 20,000 neutrophils/ml plus ET and in the presence of a combination of ET and flunixin meglumine for 1 or 3 hours. Endotoxin alone did not cause cell damage, and the only evidence of an effect was an increased number of secondary lysosomes at incubation hour 8. At incubation hour 24, cells appeared normal. Endotoxin plus neutrophils caused cells to become round and detach from the growth substrate. Cell pathologic changes included swollen and distorted mitochondria and cytoplasmic vacuolization. Response to the ET plus neutrophil combination was variable and ranged from 5% to 50% of the cells being affected. The variability appeared to have some correlation with cell age, as well as individual preparation of neutrophils.  相似文献   

Comparison of Stereoscopy, Light Microscopy and Ultrastructural Methods for Evaluation of Bovine Embryos   总被引：2，自引：0，他引：2  

MM Aguilar  CS Galina  H Merchant  F Montiel  R Canseco  YC Márquez 《Reproduction in domestic animals》2002,37(6):341-346

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Evaluation of the gene for inducible nitric oxide synthase as a radiosensitizer under hypoxic and oxic conditions     

M. Turek  M. Padilla  D. J. Argyle 《Veterinary and comparative oncology》2007,5(4):250-255

The radiosensitizing effect of inducible nitric oxide synthase (iNOS) was evaluated, in vitro, in a feline vaccine‐associated sarcoma (VAS) cell line and a canine osteosarcoma cell line (D17). The gene encoding the human iNOS was cloned into an expression plasmid under the control of a cytomegalovirus immediate early promoter. Transient transfections were performed in feline VAS cells and D17 cells. Nitric oxide was measured in the supernatant media 48 h later as an indirect measurement of iNOS expression. Cells were irradiated using cobalt‐60 under hypoxic or oxic conditions, and clonogenic assays were used to evaluate the effects of gene transfer on the sensitivity of cells to radiation. The results demonstrated that iNOS had no significant effect on improving the radiosensitivity of cells under oxic conditions. However, under hypoxic conditions, iNOS gene transfer significantly improved radiosensitization in osteosarcoma cells. These results demonstrate the feasibility of improving the outcome of radiotherapy in dogs with large bulky tumours using iNOS gene therapy.  相似文献   

Masitinib mesylate does not enhance sensitivity to radiation in three feline injection-site sarcoma cell lines under normal growth conditions     

M. Turek  R. Gogal Jr.  C. Saba  M.L. Vandenplas  J. Hill  B. Feldhausser  J. Lawrence 《Research in veterinary science》2014

Masitinib, a selective tyrosine kinase inhibitor, was investigated as a radiosensitizer in three primary feline injection-site sarcoma (ISS) cell lines. Sensitivity to masitinib was previously assessed via cell growth inhibition assays with mean IC₅₀ values of 5.5–8.6 μM. Clonogenic assays were performed to determine the effect of masitinib and radiation on cell survival. Single dose radiation (0–12 Gy) experiments were carried out under normal growth conditions in control ISS cells and in cells incubated with 1 or 6 μM masitinib for 72 h prior to irradiation. Radiation administered either alone or in combination with masitinib induced a dose-dependent reduction in clonogenic survival. Survival from the combined masitinib and radiation treatment was not significantly different from that of radiation alone. Results suggest that masitinib does not directly enhance ISS cell radiosensitivity under normal in vitro conditions, although this does not preclude the utility of further investigations to assess sensitization properties under altered conditions.  相似文献   

In vitro efficacy of doxorubicin and etoposide against a feline injection site sarcoma cell line     

Joseph Hill  Jessica Lawrence  Corey Saba  Michelle Turek  Brittany Feldhaeusser  Sheryl Coutermarsh-Ott  Jamie Barber  Jo Smith  Robert Gogal Jr 《Research in veterinary science》2014

Feline injection site sarcoma (ISS) is a locally invasive tumor, in which surgical treatment is frequently combined with radiation or chemotherapy to improve tumor control. The focus of this study was to evaluate the cytotoxic effects of doxorubicin or etoposide on a feline injection site sarcoma cell line (JB) and to assess the impact of combining these drugs on cell death and cell cycle. Both single agent and combination drug administration increased cell death and significantly reduced the number of viable cells. Cells in G0/G1 were significantly reduced while the G2/M fraction was significantly increased following treatment. Collectively, combining doxorubicin and etoposide at the lower EC yielded comparable results to the EC50 of either drug alone in degree of cytotoxicity, level of apoptosis, and % of cells in G2/M. The results of this study indicate that doxorubicin and etoposide alone and in combination differentially alter ISS cell viability and cycle.  相似文献   

Effect of Acute Bull Exposure Around the Time of Artificial Insemination on Serum Oxytocin and Progesterone Concentrations and Pregnancy Rates in Dairy Cows     

MM Ababneh  IN Obeidat  MQ Husein  AQ Talafha 《Reproduction in domestic animals》2013,48(2):223-230

This study examined the effect of acute bull exposure around the time of artificial insemination (AI) on oxytocin and progesterone concentrations, and pregnancy rates in dairy cows. Ninety six dairy cows, stratified according to parity into primiparous and pluriparous, were divided into three groups; short bull exposure (SBE; 10 min, n = 32), long bull exposure (LBE; 4 h, n = 32) or no bull exposure (NBE; n = 32). On day 45 post‐partum, all cows were treated with PGF2α on three occasions 11–14 days apart to synchronize oestrus. They were submitted to fixed time AI 80 h after the third PGF2α injection. Cows in the SBE and LBE groups were artificially inseminated 5 min after the introduction of the bull. From a subset of cows (n = 6 per group; three primiparous and three pluriparous), blood samples were collected once every 5 min starting 15 min before AI until 15 min after AI and analysed for oxytocin concentrations. Additional blood samples were collected for measurements of progesterone (P4) concentrations once daily for 4 days starting on the day of AI and once every 3 days thereafter until day 22. The effects of bull exposure, time, parity, difficulty of AI, and pregnancy on oxytocin and P4 concentrations were analysed using the mixed linear model procedure. Mean oxytocin concentrations or change in oxytocin concentrations after bull exposure or AI were not different among groups. Pregnancy rates for the NBE, SBE and LBE groups were 55.5%, 33.3% and 44.4%, respectively, and were not different among groups. In conclusion, acute bull exposure around the time of AI did not affect oxytocin and progesterone concentrations and did not improve pregnancy rates in dairy cattle under these farms conditions.  相似文献   

Obesity and metabolic syndrome in circadian Clock mutant mice   总被引：2，自引：0，他引：2  

Turek FW  Joshu C  Kohsaka A  Lin E  Ivanova G  McDearmon E  Laposky A  Losee-Olson S  Easton A  Jensen DR  Eckel RH  Takahashi JS  Bass J 《Science (New York, N.Y.)》2005,308(5724):1043-1045

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Shape differences of the Carina sterni in birds of various locomotion types     

Migena Gjoni Gündemir  Tomasz Szara  Constantin Spataru  Ismail Demircioglu  Bernard Turek  Georgios Petrovas  Mihaela Claudia Spataru 《Anatomia, histologia, embryologia》2023,52(2):190-196

The anatomy of the sternum in birds varies according to their habitats and type of locomotion. In particular, the carina sterni manifest different shape variations. In this study, the shape of the carina sterni was investigated by means of geometric morphometrics. Birds of different types of locomotion were used in the study: flying, swimming, and terrestrial. Ducks and chickens show a wider variety of shapes. Pigeons are the species with the least differences. The margo cranialis carinae in a turkey is the flattest compared to other species. In chickens, the apex carinae is more caudally than the base of the carina sterni. The margo cranialis of the carina sterni in ducks is concave. The differences in centroid size and shape differences between species collectively are statistically significant (p < 0.0001). The most distinct shape contrast is between the duck and turkey (p: 0.0003). Form differences between the ducks and geese as well as between the chicken and turkey are statistically insignificant. There is less variation in the shape of the carina sterni among avian species representing the same type of locomotion. Although there are many comparative morphological and morphometric studies of birds, shape analysis studies revealing the interspecific differences and similarities of the sternum are very limited. Morphology of the carina sterni can be useful in taxonomic investigations.  相似文献