獣医科学と技術

The purpose of this in vitro study was to compare the degradation of gemcitabine (2’, 2’-difluorodeoxycytidine, dFdC), in Fresh Whole Blood (FWB) from humans, dogs, cats, and horses. A better understanding of the comparative degradation of gemcitabine may aid in the optimal design of therapeutic regimens in veterinary species. Fresh whole blood from humans, dogs, cats, and horses was spiked with dFdC and plasma was analyzed for dFdC and 2’, 2’-difluorodeoxyuridine (dFdU) by high performance liquid chromatography. In these species, there was an initial rapid degradation of dFdC with a concomitant proportional increase in dFdU. Degradation of gemcitabine appeared similar in humans, dogs, and horses (p>0.05) whereas metabolism was slower in the cat than human (p=0.014), dog (p=0.010), or horse (p=0.0015). Based on these in vitro findings, dosing schemes for humans, dogs, and horses may be similar. In contrast, gemcitabine degradation occurred more slowly in the cat; this difference may dictate a different dosing scheme for optimal response in this species.

Q fever is a mainly airborne zoonosis with public health concern throughout the world caused by the highly contagious, obligate intracellular bacteria Coxiella burnetii. It is an important occupational zoonosis since its discovery in 1935; it has been shown to infect a wide range of hosts, including humans. Although Q fever is a disease closely related to occupations such as handling livestock, most of the previous studies concerned with general population. A recent outbreak in Europe reminds us that this is still a significant pathogen of concern, very transmissible with a very low infectious dose. For these reasons it has also featured regularly on various threat lists, as it may be considered to be used as a bio-weapon. Therefore, we reviewed the literatures on Q fever to highlight the epidemiologic, economic and public health impact of Q fever as a basis for designing effective control strategies.

Objectives: To isolate and maintain canine Wharton’s jelly mesenchymal stromal cells (WJMSC) in culture, determine the effects of micellar nanoparticles containing doxorubicin (DOX) on WJMSC and canine osteosarcoma (OSA) D17 cells, and determine the effects of WJMSC loaded with micellar nanoparticles containing DOX on OSA D17 cell viability.

Procedures: Stromal cells were isolated from canine umbilical cords. Micellar nanoparticles containing DOX were prepared and added to individual culture plates containing canine WJMSC and OSA D17 cells to determine DOX in micelles (DOX-M) effects on cell growth and viability. Conditioned media (CM) from culture plates containing canine WJMSC incubated with various DOX-M concentrations was added to OSA D17 cells. An MTT assay was performed to assess osteosarcoma D17 cell viability. A trypan blue stain was utilized to perform cell counts to determine the effect of the DOX-M on WJMSC growth.

Results: WJMSC were successfully isolated and maintained in culture. Micellar nanoparticles containing DOX decreased viability of OSA D17 cells. Osteosarcoma D17 cell viability decreased following incubation with CM obtained from WJMSC loaded with DOX-M. Significant decreases in OSA D17 cell viability were observed after incubation with the CM of canine WJMSC loaded with 10 μM DOX-M at 96 hours (p=0.0037). Significant decreases were also observed with the CM from WJMSC loaded with 1 μM DOX-M at 96 hours (p=0.0222). WJMSC numbers decreased in a dose dependent manner following incubation with DOX-M. The decrease in WJMSC number was not secondary to cytotoxicity as all variables produced similar percentages of dead WJMSC.

Conclusions: Canine WJMSC can be isolated and maintained in culture. DOX-M produces OSA D17 cytotoxicity and slows proliferation of canine WJMSC. WJMSC containing DOX-M cause OSA D17 cell cytotoxicity. These data support in vivo experiments utilizing canine WJMSC and micellar nanoparticles.