Cytotoxic effect and possible mechanisms of Tetracaine on human corneal epithelial cells in vitro

AIM： To demonstrate the cytotoxic effect and possible mechanisms of Tetracaine on human corneal epithelial（HCEP） cells in vitro.·METHODS： In vitro cultured HCEP cell were treated with Tetracaine hydrochloride at different doses for different times, and their morphology, viability, and plasma membrane permeability were detected by light microscopy, methyl thiazolyl tetrazolium（MTT） assay,and acridine orange（AO）/ethidium bromide（EB） staining,respectively. Their cell cycle progression, phosphati-dylserine orientation in plasma membrane, and mitochondrial membrane potential（MTP） were assessed by flow cytometry. DNA fragmentation, ultrastructure,caspase activation, and the cytoplasmic apoptosis inducing factor（AIF） and cytochrome c（Cyt. c） along with the expression of B-cell lymphoma-2（Bcl-2） family proteins were examined by gel electrophoresis,transmission electron microscope, enzyme linked immunosorbent assay（ELISA）, and Western blot,respectively.·RESULTS： After exposed to Tetracaine at doses from10.0 to 0.3125 g/L, the HCEP cells showed dose- and time-dependent morphological abnormality and typical cytopathic effect, viability decline, and plasma membrane permeability elevation. Tetracaine induced phosphati-dylserine externalization, DNA fragmentation, G1 phase arrest, and ultrastructural abnormality and apoptotic body formation. Furthermore, Tetracaine at a dose of0.3125 g/L also induced caspase-3,-9 and-8 activation,MTP disruption, up-regulation of the cytoplasmic amount of Cyt. c and AIF, the expressions of Bax and Bad, and down-regulation of the expressions of Bcl-2 and Bcl-x L.·CONCLUSION： Tetracaine above 0.3125 g/L（1/32 of its clinical applied dosage） has a dose- and time-dependent cytotoxicity to HCEP cells in vitro, with inducing cellapoptosis via a death receptor-mediated mitochondriondependent pathway.

Efficacy and Safety of COX-2 Inhibitor Parecoxib for Rigid Cystoscopyrelated Pain Management in Male Patients:A Prospective,Randomized and Controlled Study

Using anesthetic gel may not sufficiently exclude pain perception during and after cystoscopy in male patients.To evaluate the analgesic efficacy and safety of intramuscular parecoxib(40 mg)for outpatient-based rigid cystoscopy,we performed a prospective,randomized and controlled study.Consecutive male patients requiring diagnostic cystoscopy in our hospital were divided into group A(1%tetracaine gel,n=50)and group B(parecoxib,n^5l)at random.Patients received intramuscular injections of either 2 mL sterile saline in group A or 40 mg parecoxib in group B 30 min before the procedure.Tetracaine gel was injected into the urethra 3 min before the procedure in group A,with patients receiving plain lubricant gel in group B at the same time.Cystoscopy-associated pain levels were evaluated using the Visual Analog Score(VAS)during the procedure.Post-procedure urethral pain and complications were recorded and analyzed.The results showed that male patients experienced significantly less pain in group B than in group A(2.70±1.36 V5.3.56±1.74,P=0.008).The percentage of patients with dysuria pain was not significantly different between the two groups.In addition,24 h after cystoscopy,the patients with no previous experience of cystoscopy were more likely to declare urethral pain(59.2%vs.33.3%,P=0.012,relative risk=1.78).No difference was observed in analgesic-related complications between the two groups.We conclude that intramuscular injection of 40 mg parecoxib may improve comfort for male patients undergoing rigid cystoscopy.

Introduction of a New Concept of Pain Management during Labor and a Novel Technique for Pain Free Labor

Traditional labor epidural techniques have not been proven to be sufficient to cover the second stage of labor. We have developed a new concept of pain management during labor and a new technique that provides sufficient analgesia for second stage of labor. Combined Spinal Epidural with long lasting saddle block (with hyperbaric tetracaine) was used. Potentially pain free labor could be achieved by using this method. Utilizing hyperbaric Tetracaine intrathecally may provide a long lasting sensory sacral blockade. Primary outcome measure was absence of pain during pushing (2nd stage of labor). Patients received additional comfort during 1st stage of labor. Sample size included all patients that requested labor epidurals since 12/22/11 when this new technique was introduced.