Pretreatment with stellate ganglion blockade before ischemia reduces infarct size in rat hearts

To investigate the role of stellate ganglion blockade [SGB] in cardio-protection against ischemia reperfusion injury. This prospective randomized, experimental study was carried out between August and October 2008 in the Department of Anesthesia, Abant Izzet Baysal University, Bolu, Turkey. Twenty-one rats were randomly divided into 3 groups; group 1 -SGB group [rats with percutaneous ganglion blockade], group 2 - preconditioned [P] group [rats that were subjected to ischemia and then reperfusion periods for 5 minutes], and group 3 - control group [rats that were injected with normal saline]. During the ligation period, the length of arrhythmia was significantly shorter in group 2 compared with group 3 [p<0.001]. The arrhythmia score in groups 1 and 2 was significantly lower compared with group 3 [p<0.001]. In the reperfusion period, the length of arrhythmia was not significantly different in all study groups [p>0.05]. But the arrhythmia score was significantly lower both in group 1 and group 3, compared with group 2 [p<0.02]. Both in the ischemic and reperfusion periods, the incidence of arrhythmia was lowest in group 1. The infarct size was measured significantly less in groups 1 and 2 compared with group 3 [p<0.001]. Pretreatment with the left SGB leads to lower arrhythmia scores and reduced infarct size in the Langendorff-perfused rat hearts compared with group 3, but not with group 2

The Effect of Risedronate on Posterior Lateral Spinal Fusion in a Rat Model

OBJECTIVE: To evaluate the potential effects of risedronate (RIS) which shows a higher anti-resorptive effect among bisphosphonates, after a posterolateral lumbar intertransverse process spinal fusion using both autograft and allograft in a rat model. METHODS: A totoal of 28 Sprague-Dawley rats were randomized into 2 study groups. A posterolateral lumbar intertransverse process spinal fusion was peformed using both autograft and allograft in a rat model. Group I (control) received 0.1 mL of steril saline (placebo) and Group II (treatment) received risedronate, equivalent to human dose (10 microgram/kg/week) for 10-weeks period. RESULTS: The fusion rates as determined by manual palpation were 69% in the group I and 46% in the group II (p = 0.251). According to radiographic score, the spinal segment was considered to be fused radiographically in 7 (53%) of the 13 controls and 9 (69%) of the 13 rats treated with RIS (p = 0.851). The mean histological scores were 5.69 +/- 0.13 and 3.84 +/- 0.43 for the control and treatment groups, respectively. There was a significant difference between the both groups (p = 0.001). The mean bone density of the fusion masses was 86.9 +/- 2.34 in the control group and 106.0 +/- 3.54 in the RIS treatment group. There was a statistical difference in mean bone densities of the fusion masses comparing the two groups (p = 0.001). CONCLUSION: In this study, risedronate appears to delay bone fusion in a rat model. This occurs as a result of uncoupling the balanced osteoclastic and osteoblastic activity inherent to bone healing. These findings suggest that a discontinuation of risedronate postoperatively during acute fusion period may be warranted.