Effects of customized resin base on bonding strength of spherical self-ligating brackets.

PURPOSE: Fabricating resin bases has become an easy and economical method to achieve the customization of brackets. This study aimed to assess the effect of the resin base on bonding strength of spherical self-ligating brackets. METHODS: A defined amount of adhesive was bonded to the bracket base and constituted the new resin base. The thickness of the adhesive was measured and controlled at 0.5, 1.0, 1.5 and 2.0 mm, and a group without a resin base was used as a control. Sixty extracted human premolars were randomly divided into five groups. The brackets in each group were bonded to the specimen, and debonding tests were conducted. The shear bond strength (SBS) was calculated according to the measured debonding force in relation to the base area. The adhesive remnant index (ARI) score and the residual location of the fractured resin base were recorded. Enamel damage was also analyzed by scanning electron microscopy. After assessing for data normality and homogeneity, statistical comparisons between the groups and correlations among parameters were determined. P < 0.05 was regarded as significant. RESULTS: The correlation analysis revealed an inverse correlation between the resin base thickness and the SBS (Coeff = -0.719, P < 0.01). The highest SBS was 9.33 MPa, in the control group, which was significantly greater than the lowest SBS (6.03 MPa), in the 2.0-mm group (P < 0.05). Multiple comparisons analysis revealed no differences in SBS between the 1.0-, 1.5- and 2.0-mm groups. Nonparametric analysis found that only the ARI score in the 0.5-mm group (2.92) was significantly different (P < 0.05) from that in the control group (1.25). As the thickness of the resin base increased, the fractured resin base tended to remain at the bracket base, and the risk of enamel damage decreased. CONCLUSIONS: As the thickness of the resin base increased, the bonding strength of the spherical bracket decreased. However, the required clinical bonding strength was still satisfied when the thickness was less than 2.0 mm. The existence of a resin base could protect the enamel surface from damage caused by debonding. The customization of spherical brackets by tailoring a resin base can be applied in clinical practice because of the clinically acceptable bonding strength.

Effects of intraoperative PEEP on postoperative pulmonary complications in high-risk patients undergoing laparoscopic abdominal surgery: study protocol for a randomised controlled trial.

INTRODUCTION: Postoperative pulmonary complications (PPCs), strongly associated with higher mortality risk, can develop in up to 58% of patients undergoing abdominal surgery. More and more evidence shows that the use of a lung-protective ventilation strategy has a lung protection effect in patients undergoing abdominal surgery, however, the role of positive end-expiratory pressure (PEEP) during the intraoperative period in preventing PPCs for laparoscopic surgery is not clearly defined. METHODS AND ANALYSIS: A total of 208 patients with a high risk of PPC, undergoing laparoscopic abdominal surgery, will be enrolled and randomised into a standard PEEP (6-8 cm H2O) group and a low PEEP (≤2 cm H2O) group. Both groups will receive a fraction of inspired oxygen of 0.50 and a tidal volume of 8 mL/kg ideal body weight (IBW). Standard perioperative fluid management and analgesic treatments are applied in both groups. The primary end point is PPC within 7 days after surgery. Secondary end points are the modified Clinical Pulmonary Infection Score, postoperative extrapulmonary complications, postoperative surgical complications, intensive care unit length of stay, hospital length of stay, 30-day mortality. ETHICS AND DISSEMINATION: The study was approved by the Ethics Committee of Zhejiang Provincial People's Hospital (People's Hospital of Hangzhou Medicine College) (registration number KY2018026) on 22 October 2018. The first participant was recruited on 15 April 2019 and the estimated completion date of the study is October 2021. The results of this trial will be submitted to a peer-reviewed journal. TRIAL REGISTRATION NUMBER: http://www.chictr.org.cn, ID: ChiCTR1800019865. Registered on 2 December 2018; preresults.

Effects of intraoperative PEEP on postoperative pulmonary complications in patients undergoing robot-assisted laparoscopic radical resection for bladder cancer or prostate cancer: study protocol for a randomized controlled trial.

BACKGROUND: There are increasing studies showing that the use of a lung-protective ventilation strategy has a lung protection effect in patients undergoing abdominal surgery; however, the appropriate positive end-expiratory pressure (PEEP) has not yet defined. Adopting a suitable PEEP may prevent postoperative pulmonary complications. Robot-assisted laparoscopic surgery is the newest and most minimally invasive treatment for bladder cancer or prostate cancer. It is also necessary to consider the effects of Trendelenburg position with pneumoperitoneum on airway pressure and pulmonary function. The role of PEEP during the intraoperative period in preventing postoperative pulmonary complications for robot-assisted laparoscopic surgery is not clearly defined. METHODS/DESIGN: A total of 208 patients undergoing robot-assisted laparoscopic radical resection for bladder cancer or prostate cancer will be enrolled and then randomly assigned to a standard PEEP (6-8 cm H2O) group and a low PEEP (≤2 cm H2O) group. Both groups will receive an inspired oxygen fraction of 0.50 and a tidal volume of 8 mL/kg ideal body weight. Standard perioperative fluid management standardization and analgesic treatments will be applied in both groups. The primary endpoint is postoperative pulmonary complications within 7 days after surgery. Secondary endpoints are the modified clinical pulmonary infection score, postoperative extrapulmonary complications, postoperative surgical complications, intensive care unit length of stay, hospital length of stay, and 30-day mortality. DISCUSSION: This trial aimed to assess the effects of low tidal volumes combined with intraoperative PEEP ventilation strategy on postoperative pulmonary complications in patients undergoing robot-assisted laparoscopic radical resection for bladder cancer or prostate cancer. TRIAL REGISTRATION: ID: ChiCTR1800019867 . Registered on December 2, 2018.

Postoperative tight glycemic control significantly reduces postoperative infection rates in patients undergoing surgery: a meta-analysis.

BACKGROUND: The benefit results of postoperative tight glycemic control (TGC) were controversial and there was a lack of well-powered studies that support current guideline recommendations. METHODS: The EMBASE, MEDLINE, and the Cochrane Library databases were searched utilizing the key words "Blood Glucose", "insulin" and "Postoperative Period" to retrieve all randomized controlled trials evaluating the benefits of postoperative TGC as compared to conventional glycemic control (CGC) in patients undergoing surgery. RESULTS: Fifteen studies involving 5053 patients were identified. As compared to CGC group, there were lower risks of total postoperative infection (9.4% vs. 15.8%; RR 0.586, 95% CI 0.504 to 0.680, p <  0.001) and wound infection (4.6% vs. 7.2%; RR 0.620, 95% CI 0.422 to 0.910, p = 0.015) in TGC group. TGC also showed a lower risk of postoperative short-term mortality (3.8% vs. 5.4%; RR 0.692, 95% CI 0.527 to 0.909, p = 0.008), but sensitivity analyses showed that the result was mainly influenced by one study. The patients in the TGC group experienced a significant higher rate of postoperative hypoglycemia (22.3% vs. 11.0%; RR 3.145, 95% CI 1.928 to 5.131, p <  0.001) and severe hypoglycemia (2.8% vs. 0.7%; RR 3.821, 95% CI 1.796 to 8.127, p <  0.001) as compared to CGC group. TGC showed less length of ICU stay (SMD, - 0.428 days; 95% CI, - 0.833 to - 0.022 days; p = 0.039). However, TGC showed a neutral effect on neurological dysfunction (1.1% vs. 2.4%; RR 0.499, 95% CI 0.219 to 1.137, p = 0.098), acute renal failure (3.3% vs. 5.4%, RR 0.610, 95% CI 0.359 to 1.038, p = 0.068), duration of mechanical ventilation (p = 0.201) and length of hospitalization (p = 0.082). CONCLUSIONS: TGC immediately after surgery significantly reduces total postoperative infection rates and short-term mortality. However, it might limit conclusion regarding the efficacy of TGC for short-term mortality in sensitivity analyses. The patients in the TGC group experienced a significant higher rate of postoperative hypoglycemia. This study may suggest that TGC should be administrated under close glucose monitoring in patients undergoing surgery, especially in those with high postoperative infection risk.

Location- and Subunit-Specific NMDA Receptors Determine the Developmental Sevoflurane Neurotoxicity Through ERK1/2 Signaling.

It is well established that developmental exposure of sevoflurane (an inhalational anesthetic) is capable of inducing neuronal apoptosis and subsequent learning and memory disorders. Synaptic NMDA receptors activity plays an essential role in cell survival, while the extra-synaptic NMDA receptors activation is usually associated with cell death. However, whether synaptic or extra-synaptic NMDA receptors mediate developmental sevoflurane neurotoxicity is largely unknown. Here, we show that developmental sevoflurane treatment decreased NR2A, but increased NR2B subunit expression both in vitro and in vivo. Sevoflurane-induced neuronal apoptosis was attenuated by synaptic NMDA receptors activation or low dose of exogenous NMDA in vitro. Interestingly, these effects could be abolished by NR2A inhibitor PEAQX, but not NR2B inhibitor Ifenprodil in vitro. In contrast, activation of extra-synaptic NMDA receptors alone had no effects on sevoflurane neurotoxicity. In the scenario of extra-synaptic NMDA receptors stimulation, however, sevoflurane-induced neuronal apoptosis could be prevented by addition of Ifenprodil, but not by PEAQX in vitro. In addition, sevoflurane neurotoxicity could also be rescued by memantine, an uncompetitive antagonist for preferential blockade of extra-synaptic NMDA receptors both in vitro and in vivo. Furthermore, we found that developmental sevoflurane-induced phospho-ERK1/2 inhibition was restored by synaptic NMDA receptor activation (in vitro), low dose of NMDA (in vitro) or memantine (in vivo). And the neuroprotective role of synaptic NMDA activity was able to be reversed by MEK1/2 inhibitor U0126 in vitro. Finally, administration of memantine or NMDA significantly improved spatial learning and memory dysfunctions induced by developmental sevoflurane exposure without influence on locomotor activity. These results indicated that activation of synaptic NR2A-containing NMDA receptors, or inhibition of extra-synaptic NR2B-containing NMDA receptors contributed to the relief of sevoflurane neurotoxicity, and the ERK1/2 MAPK signaling may be involved in this process.

Inhibition of aberrant cyclin-dependent kinase 5 activity attenuates isoflurane neurotoxicity in the developing brain.

Aberrant CDK5 activity is implicated in a number of neurodegenerative disorders. Isoflurane exposure leads to neuronal apoptosis, and subsequent learning and memory defects in the developing brain. The present study was designed to examine whether and how CDK5 activity plays a role in developmental isoflurane neurotoxicity. Rat pups and hippocampal neuronal cultures were exposed to 1.5% isoflurane for 4 h. The protein and mRNA levels of CDK5, p35 and p25 were detected by western blot and QReal-Time PCR. CDK5 activity was evaluated in vitro using Histone H1 as a substrate. Roscovitine (an inhibitor of CDK5) was applied before isoflurane treatment, cleaved Caspase-3, Bcl-2, Bax, MEF2 and phospho-MEF2A-Ser-408 expressions were determined. Dominant-Negative CDK5 was transfected before isoflurane treatment. Neuronal apoptosis was evaluated by Flow cytometry (FCM) and TUNEL-staining. Cognitive functions were assessed by Morris water maze. We found that isoflurane treatment led to an aberrant CDK5 activation due to its activator p25 that was cleaved from p35 by calpain. Inhibition of CDK5 activity with Roscovitine enhanced Bcl-2, and decreased cleaved Caspase-3 and Bax expressions. In addition, isoflurane exposure resulted in a decrease of MEF2 and increase of phospho-MEF2A-Ser-408, which were rescued by Roscovitine or Dominant-Negative CDK5 transfection. Dominant-Negative CDK5 transfection also decreased the percentage of TUNEL-positive cells in isoflurane neurotoxicity. Moreover, Roscovitine remarkably alleviated the learning and memory deficits induced by postnatal isoflurane exposure. These results indicated that aberrant CDK5 activity-dependent MEF2 phosphorylation mediates developmental isoflurane neurotoxicity. Inhibition of CDK5 overactivation contributes to the relief of isoflurane neurotoxicity in the developing brain.

Comparison of dexmedetomidine and sufentanil for conscious sedation in patients undergoing awake fibreoptic nasotracheal intubation: a prospective, randomised and controlled clinical trial.

INTRODUCTION: Fibreoptic intubation is a valuable technique for difficult airway management in which conscious sedation is paramount. OBJECTIVES: To investigate the efficacy and safety of dexmedetomidine (DEX) and sufentanil (SUF) for conscious sedation during awake nasotracheal intubation under vision by a fibreoptic bronchoscope. METHODS: Forty patients with anticipated difficult airways of American Society of Anesthesiologists I-II scheduled for awake fibreoptic nasotracheal intubation were randomised into two groups each containing 20 subjects. DEX group received DEX at a dose of 1.0 µg/kg over 10 min followed by a continuous infusion of 0.5 µg/kg per hour, while SUF group received SUF target controlled infusion in which the target plasma concentration was 0.3 ng/mL. The nasotracheal intubation conditions and the tolerance to nasotracheal intubation were observed; the occurrence of adverse events including hypertension, bradycardia and respiratory depression during nasotracheal intubation and post-surgical throat pain and hoarseness, and post-surgical memory score were recorded. RESULTS: Better nasotracheal intubation conditions and higher tolerance to intubation were observed in DEX group than those in SUF group (P < 0.05). The incidence rates of hypertension, respiratory depression during intubation and throat pain after surgery were lower in DEX group than those in SUF group; however, the incidence of bradycardia was higher in DEX group than that in SUF group. CONCLUSIONS: DEX provides better nasotracheal intubation conditions, improves patients' tolerance to intubation and leads to lower occurrence of hypertension, respiratory depression and throat pain and post-surgical memory score for sedation during awake fibreoptic nasotracheal intubation.

N-stearoyl-L-tyrosine ameliorates sevoflurane induced neuroapoptosis via MEK/ERK1/2 MAPK signaling pathway in the developing brain.

N-arachidonoylethanolamine (AEA) plays a crucial neuroprotective role in certain neurodegenerative diseases. Our recent studies suggested that AEA analog N-stearoyl-l-tyrosine (NsTyr) could protect neurons from apoptosis and improve hippocampus-dependent learning and memory deficits. The present study was designed to determine the neuroprotective effect of NsTyr on developmental sevoflurane neurotoxicity using primary hippocampal neuronal cultures and rat pups. We found that NsTyr could decrease cell viability and reduce apoptosis in sevoflurane treated neuronal cultures. In addition, NsTyr attenuated sevoflurane-induced apoptosis by modulating Caspase-3 and Bcl-2 in vivo. Moreover, sevoflurane exposure led to an inhibition of phospho-ERK1/2, which was rescued by NsTyr. Administration of U0126 (an inhibitor of MEK) abolished the neuroprotective effect of NsTyr on sevoflurane neurotoxicity both in vitro and in vivo. Finally, administration of NsTyr improved the learning and memory disorders induced by postnatal sevoflurane exposure without alteration in locomotor activity. These results indicated that AEA analog NsTyr protects developing brain against developmental sevoflurane neurotoxicity possibly through MEK/ERK1/2 MAPK signaling pathway.

[Effect of long-term sevoflurane anesthesia on markers of myocardial damage].

OBJECTIVE: To investigate the effect of long-term sevoflurane anesthesia on markers of myocardial damage or toxicity. METHODS: Forty adult patients scheduled for upper abdominal surgery with general anesthesia for 4 hours or more were randomly divided into Group S and PR (n=20 each). After anesthesia induction, patients of Group S were maintained with only sevoflurane, and patients of Group PR with target-controlled infusion of propofol 2-4 microg/ml and remifentanil 4-8 ng/ml. Anesthesia was titrated to control blood pressure and heart rate change at less than 20 percent of baseline values. Blood samples were draw at pre-induction, 4 h and 24 h post-induction respectively. Serum level of cardiac troponin I, creatine kinase MB and myoglobin were analyzed. RESULTS: There were no significant changes of troponin I, creatine kinase MB and myoglobin in Group S between pre-induction and 4 h or 24 h post-induction (P > 0.05). And there was also no significant differences as compared with Group PR (P > 0.05). CONCLUSION: At the concentration range of 1.6%-3%, long-term sevoflurane anesthesia does not cause detectable changes of markers of myocardial damage or toxicity.

[Comparison of three different organ failure assessment score systems in predicting outcome of severe sepsis].

OBJECTIVE: To compare multiple organ dysfunction score (MODS), the sequential organ failure assessment (SOFA) and the logistic organ dysfunction score (LODS) in predicting hospital mortality in severe sepsis. METHODS: Four hundred and three patients admitted to the ICU from December 2004 to November 2007 with a diagnosis of severe sepsis were enrolled in this study. Their MODS, SOFA, LODS and Acute Physiology and Chronic Health Evaluation (APACHE) II at admission and the highest score during hospitalization were respectively recorded and collected in regard to mortality. The discrimination of three multiple organ dysfunction score systems were assessed by the areas under the receiver operating characteristic curves (AUC). RESULTS: The AUC of admission scores was 0.811 for LODS, 0.787 for SOFA, 0.725 for MODS, and 0.770 for APACHE II in predicting hospital mortality. All maximum scores had better power of discrimination than the admission scores (P < 0.01). The power of discrimination of LODS and SOFA were better than the MODS, either the admission or the highest, respectively (P < 0.01). However, no significant difference was observed between the LODS and the SOFA regarding mortality prediction (P > 0.05). The AUC value for the APACHE II score was much lower compared to LODS (P < 0.01). However, there was no difference in AUC value among APACHE II, SOFA and MODS (P > 0.05). CONCLUSION: LODS, SOFA and MODS show a good discrimination power, while maximum LODS is of the highest discrimination power to predict the outcome of patient with severe sepsis.

[Effects of preemptive analgesia with flurbiprofen on the blood sugar and interleukin-6 of patients after radical excision of breast cancer].

OBJECTIVE: To investigate the effects of preemptive analgesia with flurbiprofen on the blood sugar and Interleukin-6 of patients after radical excision of breast cancer. METHODS: A total of 60 ASA I-II patients scheduled for radical excision of breast cancer were randomly assigned to three groups: group A, B and C (n = 20 each), patients of group A and C received intravenous flurbiprofen 100 mg before or at the end of surgery respectively. Blood samples were collected from the patients before anaesthesia induction and 1, 6, 24 h after surgery for the determination of blood sugar and serum interleukin-6 concentration. Analgesic efficacy was assessed after surgery based on visual analog scales (VAS). RESULTS: The blood sugar and serum interleukin-6 concentration of the patients in three groups at different time points after surgery were significantly higher than those before surgery, and increased gradually in group B, and there were very significant difference between the time point of 1 h and 24 h after surgery (P < 0.01), but there were no increasing trend for those of group A and C. The blood sugar and serum interleukin-6 concentration of the patient of group A were significantly lower than those of group B and C (P < 0.01 or 0.05). The highest VAS of group A and C at different time points after surgery were significantly lower than that of group B(P < 0.05). CONCLUSION: Preemptive analgesia with flurbiprofen 100 mg can effectively suppress the elevation of blood sugar and serum interleukin-6 concentration after radical excision of breast cancer, and is better than postoperation analgesia.