Change in the Alignment and Distal Junctional Kyphosis Development after Posterior Cervical Spinal Fusion Surgery for Cervical Spondylotic Myelopathy – Risk Factor Analysis

Objective@#: This study analyzed the risk factors in patients who developed distal junctional kyphosis (DJK) after posterior cervical fusion. @*Methods@#: We retrospectively analyzed the clinical and radiographic outcomes of 64 patients, aged ≥18 years (51 and 13 male and female patients, respectively), who underwent single-staged multilevel (3–6 levels) posterior cervical fusion surgery due to multiple cervical spondylotic myelopathy. The surgeries were performed by a single spinal surgeon between January 2012 and December 2017. Demographic data, clinical outcomes, and radiological results were collected. We divided the patients into a DJK group and a non-DJK group according to the presence of DJK and investigated the risk factors by comparing the differences between the two groups. @*Results@#: Of the 64 patients, 13 developed DJK. No significant differences in clinical results were observed between the two groups before and immediately after the surgery. At the final follow-up, a higher visual analog score for neck pain was observed in the DJK group compared to the non-DJK group (p<0.01). The DJK group had a significantly lower T1 slope and a significantly higher C2-7 sagittal vertical axis (SVA) before surgery compared to the non-DJK group (p=0.03 and p<0.01, respectively). Immediately after surgery, the difference between the two groups decreased and no significant difference was observed. However, at the last followup, a significantly higher C2-7 SVA was observed in the DJK group (p<0.01). At the last follow up, there is no discrepancy in T1S-CL. In multiple logistic regression analysis, preoperative higher C2-7 SVA and preoperative lower T1 slope were identified as independent risk factors (p=0.03 and p<0.01, respectively). As a result, it was confirmed that DJK occurred along the process of returning to preoperative values. @*Conclusion@#: DJK can be considered to be caused by cervical misalignment due to excessive change in the surgical site in patients with low T1 slope and high C2-7 SVA before surgery. This also affects the clinical outcome after surgery. It is recommended to refrain from excessive segmental lordosis changes during multilevel cervical post fusion surgery, especially in patients with a small preoperative T1 slope and a large SVA value.

Effect of YJ-7 (a calcium channel blocker) on blood pressure regulation in spontaneous hypertensive rat model

BACKGROUND: Farnesylacetone compounds that dilate blood vessels by blocking calcium channels in sargassum siliquastrum have been reported. And this study was done to demonstrate the effect of YJ-7, a synthetic material derived from these compounds, on vessel dilation and blood pressure control. METHODS: We used vasoconstricted basilar and carotid artery of rabbits. Changes in blood pressure were measured in vivo at 15, 30, 45, and 60 minutes after intravenous injection of YJ-7 3 microM, EC50 value from in vitro experiment, and nimodipine 10 microM through the tail vein of 20 rats. Spontaneous hypertensive rat (SHR) has its blood pressure higher than 190 mmHg. Measurements of blood pressure were done 6 times and the mean values were used for data analysis. RESULTS: Systolic and diastolic blood pressure before the injection of YJ-7 were 194.2 +/- 6.1 mmHg and 140.2 +/- 6.4 mmHg. Blood pressure were decreased with time, 157.2 +/- 2.6 / 120.8 +/- 4.2 mmHg at 15 minutes, 161.8 +/- 18.3 / 123.2 +/- 13.9 mmHg at 30 minutes, and 156.0 +/- 4.1 / 112.4 +/- 1.7 mmHg at 45 minutes. The blood pressure lowering effect lasted until 45 minutes. However, the blood pressure increased to 182.2 +/- 16.4 / 149.0 +/- 20.4 mmHg at 60 minutes reaching similar levels of before the injection (P < 0.05). CONCLUSIONS: We could see YJ-7 has vasorelaxation effect and would be helpful to control blood pressure with short recovery period than nimodipine.

Mechanisms of Motility Change on Trinitrobenzenesulfonic Acid-Induced Colonic Inflammation in Mice

Ulcerative colitis is an inflammatory bowel disease (IBD) characterized by recurrent episodes of colonic inflammation and tissue degeneration in human or animal models. The contractile force generated by the smooth muscle is significantly attenuated, resulting in altered motility leading to diarrhea or constipation in IBD. The aim of this study is to clarify the altered contractility of circular and longitudinal smooth muscle layers in proximal colon of trinitrobenzen sulfonic acid (TNBS)-induced colitis mouse. Colitis was induced by direct injection of TNBS (120 mg/kg, 50% ethanol) in proximal colon of ICR mouse using a 30 G needle anesthetized with ketamin (50 mg/kg), whereas animals in the control group were injected of 50% ethanol alone. In TNBS-induced colitis, the wall of the proximal colon is diffusely thickened with loss of haustration, and showed mucosal and mucular edema with inflammatory infiltration. The colonic inflammation is significantly induced the reduction of colonic contractile activity including spontaneous contractile activity, depolarization-induced contractility, and muscarinic acetylcholine receptor-mediated contractile response in circular muscle layer compared to the longitudinal muscle layer. The inward rectification of currents, especially, important to Ca2+ and Na+ influx-induced depolarization and contraction, was markedly reduced in the TNBS-induced colitis compared to the control. The muscarinic acetylcholine-mediated contractile responses were significantly attenuated in the circular and longitudinal smooth muscle strips induced by the reduction of membrane expression of canonical transient receptor potential (TRPC) channel isoforms from the proximal colon of the TNBS-induced colitis mouse than the control.