Analgesic Effects of Intra-Articular Bupivacaine/Intravenous Parecoxib Combination Therapy versus Intravenous Parecoxib Monotherapy in Patients Receiving Total Knee Arthroplasty: A Randomized, Double-Blind Trial.

OBJECTIVES: The purpose of this double-blind, randomized study was to investigate whether the addition of intra-articular bupivacaine to intravenous parecoxib could improve pain relief in patients undergoing total knee arthroplasty. METHODS: A total of 36 patients undergoing total knee arthroplasty were enrolled into our study. These patients were randomly allocated either to a placebo-controlled group or study group. Postoperative pain cores and analgesic consumption were evaluated. RESULTS: Numeric rating scale (NRS) data of bupivacaine group in postoperative room were significantly lower than that of control group (control group versus bupivacaine group, 7.9 (6.7-9.1) (mean and 95% confidence interval) versus 4.5 (3.2-5.8) (mean and 95% confidence interval), p = 0.001). NRS data of bupivacaine group in ward were also significantly lower than that of control group. A significantly lower dose of meperidine was used in the study group postoperatively during the first 24 hours (control group versus bupivacaine group, 3.08 ± 0.80 mg/Kg versus 2.34 ± 0.42 mg/Kg, p = 0.001). CONCLUSION: Intra-articular bupivacaine in combination with intravenous parecoxib may improve pain relief and reduce the demand for rescue analgesics in patients undergoing total knee arthroplasty. The trial is registered with Australian New Zealand Clinical Trials Registry (ACTRN12615000463572).

Acute phorbol ester treatment inhibits thapsigargin-induced cell death in porcine aortic smooth muscle cells.

We have previously shown that, in porcine aortic smooth muscle cells, endoplasmic reticulum (ER) stressor thapsigargin simultaneously activate the mitochondrial caspase-dependent death cascade and an extracellular signal-regulated kinase (ERK)-dependent pathway, which inhibits the caspase-independent death pathway. Our aim in the present study was to examine the effect of the phorbol ester phorbol 12-myristate 13-acetate (PMA) on these processes. We found that thapsigargin induced autophagy, which led to cell death. Treatment of cells with PMA for 5min, which activates protein kinase C (PKC), partially inhibited thapsigargin-induced cell death, whereas PMA treatment for 24h, which downregulates PKC, did not. This protection after short PMA treatment was not due to inhibition of the thapsigargin-induced cytosolic calcium concentration increase, mitochondrial permeability transition pore (PTP) opening, or caspase-3 activation, but coincided with increased ERK phosphorylation and decreased autophagosome formation and the decreased autophagosome formation was prevented by the ERK kinase inhibitor PD98059. Thus, under conditions of ER stress caused by thapsigargin-induced disturbance of calcium homeostasis, PKC activation induced ERK phosphorylation, which inhibited autophagic, but not apoptotic, cell death. After acute PMA treatment, protection against thapsigargin-induced cell death was enhanced by the pan-caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp(O-Me) fluoromethyl ketone or the PTP blocker cyclosporin A, but decreased by PD98059 or the PKC inhibitor Go6983. Taken together, these results suggest that PKC activation alleviates ER stress and that this is attributable to enhanced ERK phosphorylation, which inhibits autophagic, but not apoptotic, cell death.