Metabonomic potential plasma biomarkers in abnormal fast buoyancy ascent escape-induced decompression sickness model and the protective effects of pyrrolidine dithiocarbamic acid.

BACKGROUND: Decompression sickness (DCS) induced by fast buoyancy ascent escape (FBAE) is a special DCS, characterized with cardiopulmonary injuries. Serum metabonomics of this type of DCS has not yet been studied. We proposed a metabonomics approach for assessing serum metabonomics changes and evaluating the preventive effect of pyrrolidine dithiocarbamic acid (PDTC) in FBAE-induced DCS rats. METHODS: Sixty-five (65) rats were divided into three groups, including the Control, DCS and PDTC groups. After receiving physiological saline or PDTC pretreatment, rats in the DCS and PDTC groups received the same protocol of simulated FBAE. Following this, a metabonomics approach - combined with pattern recognition methods including PCA and PLS-DA - was used to characterize the global serum metabolic profile on survival rats (five rats per group) associated with abnormal FBAE-induced DCS. As the VIP-value threshold cutoff of the metabolites was set to 2, metabolites above this threshold were filtered out as potential target biomarkers. RESULTS: Sixteen (16) distinct potential biomarkers in rat plasma were identified. PDTC significantly lowered DSC mortality from 60% to 10%, and alleviated ultrastructural alteration of the left ventricular apex compared to the DCS group. It was found that abnormal FBAE-induced DCS was closely related to disturbed fatty acid metabolism, glycerophospholipid metabolism, sterol lipid metabolism, and bile acid metabolism. With the presented metabonomic method, we systematically analyzed the protective effects of PDTC. CONCLUSION: The results demonstrated that PDTC administration could provide satisfactory effects on abnormal FBAE-induced DCS through partially regulating the perturbed metabolic pathways.

Efficacy of pulsed radiofrequency in the treatment of thoracic postherpetic neuralgia from the angulus costae: a randomized, double-blinded, controlled trial.

BACKGROUND: Postherpetic neuralgia (PHN) is often refractory to existing treatments. Pulsed radiofrequency (PRF) is known to be effective for treating neuropathic pain. In common, the targets of PRF treatment were the segmental dorsal root ganglion (DRG) neurons responsible for the pain. A potential complication that can occasionally occur with PRF treatment is damage to the adjacent tissue and organ. The effectiveness of the angulus costae as a puncture site for PRF has not been tested in thoracic PHN treatment. OBJECTIVE: The goal of this study was to investigate the therapeutic efficacy and safety of PRF for treating thoracic PHN through the puncture of the angulus costae. STUDY DESIGN: Prospective, randomized, double-blinded study. SETTING: Department of Anesthesiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine. METHODS: Ninety-six patients with thoracic (T2-11) PHN were equally randomized assigned into 2 groups. The electrode needle punctured through the angulus costae of each patient guided by x-ray; PRF at 42° C for 120 seconds was applied after inducing paresthesia involving the affected dermatome area. PRF was applied in the PRF group (n = 48) twice. It was also applied in the sham group (n = 48) twice without radiofrequency energy output. The treatment was done once a week for 3 weeks. Tramadol was used for flare pain when the visual analog scale (VAS) ≥ 3. OUTCOMES ASSESSMENT: The therapeutic effect was evaluated by VAS, SF-36 health survey questionnaire, side effects (type, frequency, and onset time) before treatment, at days 3, 7, and 14, and at months one, 2, 3 and 6 after PRF. The average of tramadol (mg/d) administered within the first  month after treatment was also recorded. RESULTS: The postprocedure VAS scores in the PRF group were significantly lower than those in the sham group and lasted for 6 months after treatment (P < 0.05). The SF-36 score, such as physical functioning, physical role, bodily pain, general health perceptions, social function, emotional role, and mental health index were significantly improved until 6 months after treatment in the PRF group compared to the sham group (P < 0.01-0.05). The average dosage of tramadol  administrated (mg/d) within the first  month after treatment was also significantly reduced in the PRF group compared to the sham group (P < 0.05). There were no obvious signs of pneumothorax, bleeding, infection, or other severe side effects in either group (P > 0.05). LIMITATIONS: Single center study, relatively small number of patients. CONCLUSIONS: The strategy that the angulus costae be used as the PRF puncture point of an electrode needle and the final localization of the needle tip as determined by sensory testing is an effective and safe therapeutic alternative for thoracic PHN treatment. Benefits include that the procedure is minimally invasive, provides short-term pain relief, and improves quality of life. CLINICAL TRIAL REGISTRATION: NO ISRCTN25588650.