[Effects of drought on leaf growth and chlorophyll fluorescence kinetics parameters in Cyclobalanopsis glauca seedlings of Karst areas]. / å–€æ–¯ç‰¹å¹²æ—±çŽ¯å¢ƒå¯¹é’å†ˆæ Žå¶ç‰‡ç”Ÿé•¿åŠå¶ç»¿ç´ è§å ‰åŠ¨åŠ›å­¦å‚æ•°çš„å½±å“.

To uncover adaptation mechanism of Cyclobalanopsis glauca to the arid environment of Karst areas, current-year seedlings of C. glauca were potted and grown under four soil water conditions: Normal water supply (-0.1 MPa), light drought stress (-0.5 MPa), moderate drought stress (-0.9 MPa), and severe drought stress (-1.5 MPa). We measured leaf growth and parameters of fast chlorophyll fluorescence induction dynamics after treated by 15, 30, 45, 60 and 90 days. With the increase of drought stress intensity, leaf area, number of green leaves, leaf water content, the contents of chlorophyll a+b and carotenoids, the maximum fluorescence, maximum photochemical quantum yield and potential photochemical efficiency significantly decreased, while the number of dead leaves and the initial fluorescence significantly increased. There was no significant difference in these parameters between light drought and normal water treatments. There were no significant difference in the absorption flux per reaction center (ABS/RC), captured light energy used to restore qA (TRo/RC), number of active reaction centers per unit area (RC/CS), light energy captured per unit area (TRo/CS) and light energy used for electron transfer per unit area (ETo/CS) between light drought and normal water treatments. Among these parameters, RC/CS was slightly higher under light drought treatment than that of normal water treatment. TRo/CS and ETo/CS reached peaks at the 45th day, being 606.12 and 440.78, respectively. Leaf ABS/RC, TRo/RC, ETo/RC, DIRo/RC, RC/CS, TRo/CS and ETo/CS of C. glauca seedlings under mode-rate drought and severe drought treatment were lower than those of normal water treatment, and the parameters under severe drought stress decreased more significantly with the extension of drought stress time. With increasing intensity and duration of drought stress, the maximum quantum efficiency, probability of other electron acceptors, and quantum ratio of electron transfer decreased, but quantum yield for energy dissipation increased. These results demonstrated that C. glauca seedlings under light drought condition showed some degree of adaptability and resistance to drought. Mode-rate drought treatment caused a decline in chlorophyll fluorescence and photosynthetic pigments, leading to slow growth of seedlings. Severe drought had a serious impact on growth of C. glauca seedlings, but did not lead to seedling death. Therefore, C. glauca seedlings showed strong drought tolerance, which were suitable for the application of vegetation restoration and reforestation projects in Karst areas.

Preconditioning of physiological cyclic stretch inhibits the inflammatory response induced by pathologically mechanical stretch in alveolar epithelial cells.

The aim of the present study was to investigate the effects of preconditioning of physiological cyclic stretch (CS) on the overexpression of early pro-inflammatory cytokines [including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and IL-8] during the inflammatory response induced by pathologically mechanical stretch in lung epithelial cells, and to determine its molecular mechanism of action. Cells were subjected to 5% CS for various durations (0, 15, 30, 60 and 120 min) prior to 6 h treatment with pathological 20% CS. In a separate experiment, cells were preconditioned with physiological 5% CS or incubated with a nuclear factor (NF)-κB inhibitor, pyrroldine dithiocarbamate (PDTC). The expression levels of inflammatory mediators were measured using reverse transcription-quantitative polymerase chain reaction. NF-κB was quantified using western blot analysis. Preconditioning with physiological 5% CS for 30, 60 and 120 min was demonstrated to significantly attenuate the release of pathologically mechanical stretch-induced early pro-inflammatory cytokines (TNF-α, IL-1ß and IL-8) in alveolar epithelial cells (P<0.05) and significantly reduce the expression of NF-κB (P<0.05). Peak suppression was observed in cells preconditioned for 60 min. In the second set of experiments, it was demonstrated that mechanical stretch-induced release of TNF-α, IL-1ß and IL-8 was significantly inhibited by both PDTC pretreatment and 5% CS pretreatment alone (all P<0.05). Furthermore, significant inhibition was also observed when both 5% CS pretreatment and PDTC pretreatment was used on mechanical stretch-induced cells (P<0.05), which was markedly greater than the inhibition induced by either pretreatment alone. The present findings suggest that preconditioning with physiological 5% CS is able to inhibit the inflammatory response induced by pathologically mechanical stretch in alveolar epithelial cells. These anti-inflammatory effects are induced, at least in part, by suppressing the NF-κB signaling pathway.

Comparison of single- and triple-injection methods for ultrasound-guided interscalene brachial plexus blockade.

Ultrasound-guided interscalene brachial plexus blockade (IBPB) has a relatively high success rate in shoulder surgery; however, whether multiple injections are superior to a single injection (SI) is currently unknown. In the present study, ultrasound-guided SI and triple-injection (TI) IBPBs were compared in a prospective randomized trial. A total of 111 patients undergoing arthroscopic shoulder surgery and presenting with an American Society of Anesthesiologists physical status grading of I-II were randomly allocated to receive IBPB with 15 ml of 1% ropivacaine as a SI or TI. Performance time, procedure-related pain scores, success rate and prevalence of complications were recorded. The distribution of sensory and motor block onset in the radial, median, ulnar and axillary nerves were assessed every 5 min until 30 min post-local anesthetic injection. The duration of sensory and motor blocks were also assessed. A significantly longer performance time was recorded in the TI group (P<0.001). No significant difference was observed in success rate (91% in TI vs. 88% in SI) 30 min post-injection, and the prevalence of complications and procedure-related pain were similar between the two groups. Sensory and motor blocks of the ulnar nerve in the TI group were significantly faster and more successful compared with the SI group at all time points (P<0.041). It was also observed that sensory and motor blocks in the TI group were prolonged compared with the SI group (P<0.041). In conclusion, the TI method exhibited a faster time of onset and resulted in a more successful blockade of the ulnar nerve. TI method may be a more effective approach for IBPB in a clinical setting.

Efficacy of perineural dexamethasone with ropivacaine in adductor canal block for post-operative analgesia in patients undergoing total knee arthroplasty: A randomized controlled trial.

Adductor canal block (ACB) is an effective analgesic alternative to femoral nerve block after total knee arthroplasty (TKA). The aim of the present study was to investigate whether addition of dexamethasone to ropivacaine for ACB is able to prolong analgesia and reduce pain. Study participants were randomized into groups receiving ACB with either 0.5% ropivacaine + normal saline (control group; n=93) or 0.5% ropivacaine + 8 mg dexamethasone (dexamethasone group; n=93). All patients were subjected to identical peri-operative management. Patients were assessed for the duration of analgesia by the return of pinprick sensation. A numerical rating scale, ranging from 0 to 10, was used to assess post-operative pain at 6, 12, 18, 24 and 48 h. Opioid use was recorded. Serum C-reactive protein and interleukin-6 levels were measured at 3, 6, 12, 24 and 48 h after surgery. The results revealed that the duration of sensory block was significantly longer in the dexamethasone group (23.42±3.35 vs. 14.67±2.96 h in control group, P<0.05). The dexamethasone group also had significantly lower pain scores at 6, 12, 18 and 24 h after surgery (all P<0.001), and at 48 h, pain was comparable in the two groups. Reduction in post-operative pain was associated with a decrease in serum C-reactive protein. Morphine use in the first 24 h after surgery was also lower in the dexamethasone group (4.23±1.80 vs. 8.42±2.44 mg in control group, P<0.05). In conclusion, addition of dexamethasone to ropivacaine for ACB was able to prolong the duration of analgesia and decreased early post-operative pain following TKA.

Preconditioning of physiological cyclic stretch attenuated HMGB1 expression in pathologically mechanical stretch-activated A549 cells and ventilator-induced lung injury rats through inhibition of IL-6/STAT3/SOCS3.

Previous studies have shown that physiologically cyclic stretch (5% CS) attenuated both oxidative- and LPS-induced increases in HMGB1 expression via STAT3. However, little information exists about the effect of precondition of physiological cyclic stretch (CS) on the expression of HMGB 1, which play a crucial role in ventilator-induced lung injury (VILI). We found that 5% CS-preconditioning significantly inhibited HMGB 1 expression, but not HMGB 1 receptors. 5% CS-preconditioning inhibits the IL-6/STAT3 pathway, and the inhibitory effect on the expression of HMGB 1 induced by 5% CS-preconditioning is abolished by additional treatment of rmIL-6. 5% CS-preconditioning also induces SOCS3 upregulation, and 5% CS-preconditioning fails to inhibit the IL-6/STAT3 pathway in cells transfected with SOCS3 siRNA. Moreover, low tidal volume ventilation preconditioning also decreases the severity of VILI evidenced by the markedly improved pulmonary alveolar-capillary barrier dysfunction, wet/dry weight ratio, and histological analysis. These results suggest that preconditioning of physiological 5% CS can reduce the expression of HMGB 1 induced by pathologically mechanical stretch through IL-6/STAT3 pathway associated with up-regulated SOCS3 expression.