Tumorigenesis Study of Canine Adipose Derived-mesenchymal Stem Cell

Several recent studies demonstrated the potential of bioengineering using stem cells in regenerative medicine. Adult mesenchymal stem cells (MSCs) have the pluripotency to differentiate into cells of mesodermal origin, i.e., bone, cartilage, adipose, and muscle cells; they, therefore, have many potential clinical applications. On the other hand, stem cells possess a self-renewal capability similar to cancer cells. For safety evaluation of MSCs, in this study, we tested tumorigenecity of canine adipose derived mesenchymal stem cells (cAD-MSCs) using Balb/c-nu mice. In this study, there were no changes in mortality, clinical signs, body weights and biochemical parameters of all animals treated. In addition, there were no significant changes between control and treated groups in autopsy findings. These results indicate that cAD-MSC has no tumorigenic potential under the condition in this study

Changes of Pulmonary Function During 60 days of Welding Fume Exposure Period in Sprague-Dawley Rats

Respiratory effects in full time welders include bronchitis, airway irritation, lung function changes, and lung fibrosis. Welder?s pneumoconiosis has been generally determined to be benign and not associated with respiratory symptoms based on the absence of pulmonary function abnormalities in welders with marked radiographic abnormalities. Accordingly, to investigate pulmonary function changes during 60 days induced by welding-fume exposure, male Sprague-Dawley rats were exposed to manual metal arc-stainless steel (MMA-SS) welding fumes with concentrations of 64.8±0.9 mg/m3 (low dose) and 107.8 ±2.6 mg/m3 (high dose) total suspended particulates for 2 hr/day, 5 days/week in an inhalation chamber for 60 days. Pulmonary function was measured every week with whole body plethysmograph compensated (WBP Comp, SFT38116, Buxco Electronics, Sharon, CT). The rats exposed to the high dose of welding fumes exhibited statistically significant (p<0.05-0.01) body weight decrease as compared to the control whereas cell number increase of the bronchoalveolar lavage fluid (BALF) (total cell, macrophage, polymorphonuclear cell and lymphocyte) during the 60 days exposure period. And only tidal volume was significantly decreased in dose-dependantly during 60 days of MMA-SS welding fume exposure. This pulmonary function change with inflammatory cell recruitment confirms the lung injury caused by the MMA-SS welding fume exposure.N

A Teratogenicity Study on Dimethyl Dimethoxy Biphenylate Derivative (DDB-S) in Rats

A teratogenic study of dimethyl dimethoxy biphenylate derivative (DDB-S) was carriedout on Sprague-Dawley rats. DDB-S dissolved in saline was administered to male and female rats byintravenously injection at daily doses of 50 mg/kg, 75 mg/kg, and 100 mg/kg. A half of dams weresacrificed at 20th day of gestation to scrutinize the pregnant performances and fetal development.And the remaining dams were allowed to deliver. The growth, reflex, behaviour and reproductive func-tion of F1 offsprings were examined. There was no treatment-related diference in body weight, foodconsumption and necropsy findings of dams. No gross, skeletal and visceral abnormalities wasobserved in F1 fetuses from dams treated with DDB-S. F1 offsprings did not show any treatment-related diference in growth, reflex, behaviour and reproductive performance. At caesarean section ofF1 dams, no growth retardation and gross abnormality was observed in F2 fetuses. In conclusion,DDB-S did not show any potential teratogenic effect in rats.N