ABSTRACT
Objective: To design a device to increase the accuracy of the targeting process and reduce the radiation exposure to both the patients and the medical staff. Methods: We analyzed the inherent problem and designed the External Assist Targeting Device (EATD) to assist in the alignment of needle targeting on the desired renal calyx under fluoroscopic guidance. The EATD was designed to allow rapid and precise access to calyces at all angles, with a simple two-step puncture protocol developed for puncturing a target renal calyx. We then tested the device in a pilot human trial with four patients. Results: In experiments with phantom models, the time for successful targeting was reduced by 31% using the device. The mean fluoroscopic time was reduced by 40%. In initial human trial, the puncture time was shortened by 66% and the radiation dose was decreased by 65% compared to free-hand technique. No complication was observed during the trial. Conclusion: The EATD was found to be cost effective, portable, simple to set up, and safe to operate for assisting in the percutaneous nephrolithotomy procedures. Our preliminary tests showed high degree of accuracy in gaining precise access to a targeted renal calyx with much shorter time and lesser radiation dose. The EATD also has the potential to be used to access other organs with precision under fluoroscopic guidance.
ABSTRACT
The carmine spider mite (CSM) Tetranychus cinnabarinus has become a serious pest in China and has developed resistance to acaricide propargite as it is used to control mites worldwide including T. cinnabarinus. In this study, a resistant colony of T. cinnabarinus, PRR34 (37.78-fold resistant ratio), was established after 34 generations of propargite selection, and cross-resistance patterns of 7 other acaricides were determined in comparison with a susceptible strain (SS). The contribution of detoxification enzymes to propargite tolerance were investigated using biological, biochemical and molecular approaches. Enzyme inhibitor synergist tests suggested glutathione S-transferases (GST) involvement in propargite-resistance of PRR34, and GST activity against 1-chloro-2,4-dinitrobenzene (CDNB) was correlated with the development of resistance. Eight novel GST genes (TcGSTd1, TcGSTd2, TcGSTm1, TcGSTm2, TcGSTm3, TcGSTm4 and TcGSTm5) were cloned, and phylogenetic analysis showed that the eight GST genes were most closely related to GST family delta and mu from Tetranychusurticae. Quantitative RT-PCR revealed that the expression level of GSTs in PPR34 strain increased in larvae, nymphs and adults, while decreased in eggs compared with that of SS. Collectively, these results support a role of GSTs in mediating resistance to propargite in the PRR34 strain. TcGSTd1,TcGSTd2 and TcGSTm2 genes might play significant roles in propargite resistance of CSM, especially at adult stage. This is the first attempt to define specific genes involved in GST mediated propargite resistance of T. cinnabarinus at the transcriptional level.
