Sufentanil: a risk factor for lactic acidosis in patients after heart valve surgery.

BACKGROUNDS: Hyperlactatemia is a common metabolic disorder after cardiac surgery with cardiopulmonary bypass. Epinephrine use has been identified as a potential cause of increased lactate levels after cardiac surgery. Stress can lead to an increase in catecholamines, mainly epinephrine, in the body. Exogenous epinephrine causes hyperlactatemia, whereas endogenous epinephrine released by stress may have the same effect. Opioids are the most effective anesthetics to suppress the stress response in the body. The authors sought to provide evidence through a retrospective data analysis that helps investigate the relationship between intraoperative opioid dosage and postoperative lactic acidosis after cardiac surgery. METHODS: The clinical data of 215 patients who underwent valvular heart surgery with cardiopulmonary bypass from July 2016 to July 2019 were analyzed retrospectively. Blood lactate levels were measured at 0.1 h, 2 h, 4 h, and 8 h after surgery. Patients with continuous increases in lactate levels and lactate levels exceeding 5 mmol/L at two or more time points were included in the lactic acidosis group, whereas the other patients were included in the control group. First, univariate correlation analysis was used to identify parameters that were significantly different between the two groups, and then multivariate regression analysis was conducted to elucidate the independent risk factors for lactic acidosis. Fifty-one pairs of patients were screened by propensity score matching analysis (PSM). Then, lactic acid levels at four time points in both groups were analyzed by repeated measures ANOVA. RESULTS: he EF (heart ejection fraction) (OR = 0.94, P = 0.003), aortic occlusion time (OR = 10.17, P < 0.001) and relative infusion rate (OR = 2.23, P = 0.01) of sufentanil was an independent risk factor for lactic acidosis after valvular heart surgery. The patients were further divided into two groups with the mean sufentanil infusion rate as the reference point. The data were filtered with PSM (Propensity Score Matching). Lactic acid values in both groups peaked at 4 h after surgery and then declined. The rate of lactic acid decline was significantly faster in the group with a higher sufentanil dosage than in the lower group. The difference was statistically significant (P < 0.05). There was also a significant difference in lactic acid levels at the four time points (0.1 h, 2 h, 4 h and 8 h after surgery) in both groups (P < 0.001). CONCLUSION: The inadequate intraoperative infusion rate of sufentanil is an independent risk factor for lactic acidosis after heart valve surgery. The possibility of lactic acidosis caused by this factor after cardiac surgery should be considered, which is helpful for postoperative patient management.

GSK1702934A and M085 directly activate TRPC6 via a mechanism of stimulating the extracellular cavity formed by the pore helix and transmembrane helix S6.

Transient receptor potential canonical (TRPC) channels, as important membrane proteins regulating intracellular calcium (Ca2+i) signaling, are involved in a variety of physiological and pathological processes. Activation and regulation of TRPC are more dependent on membrane or intracellular signals. However, how extracellular signals regulate TRPC6 function remains to be further investigated. Here, we suggest that two distinct small molecules, M085 and GSK1702934A, directly activate TRPC6, both through a mechanism of stimulation of extracellular sites formed by the pore helix (PH) and transmembrane (TM) helix S6. In silico docking scanning of TRPC6 identified three extracellular sites that can bind small molecules, of which only mutations on residues of PH and S6 helix significantly reduced the apparent affinity of M085 and GSK1702934A and attenuated the maximal response of TRPC6 to these two chemicals by altering channel gating of TRPC6. Combing metadynamics, molecular dynamics simulations, and mutagenesis, we revealed that W679, E671, E672, and K675 in the PH and N701 and Y704 in the S6 helix constitute an orthosteric site for the recognition of these two agonists. The importance of this site was further confirmed by covalent modification of amino acid residing at the interface of the PH and S6 helix. Given that three structurally distinct agonists M085, GSK1702934A, and AM-0883, act at this site, as well as the occupancy of lipid molecules at this position found in other TRP subfamilies, it is suggested that the cavity formed by the PH and S6 has an important role in the regulation of TRP channel function by extracellular signals.

A free anterolateral thigh flap and iliotibial band for reconstruction of soft tissue defects at children's feet and ankles.

BACKGROUND AND PURPOSE: High-energy injury to children caused by a traffic accident is usually characterised by extensive soft tissue defects with exposure or loss of tendons and bone at the foot. Segmental loss of the Achilles tendon along with soft tissue defects is a great challenge for microsurgical reconstruction. Free anterolateral thigh (ALT) flap is indicated for reconstruction of such defects because limited local tissues are available. Additionally, iliotibial band in the donor area can be used to reconstruct the damaged tendon. MATERIALS AND METHODS: Here we described our successful management of 25 paediatric patients with such high-energy injury at feet and ankles in one-stage transplantation of a free ALT flap and an iliotibial band from January 2008 to January 2013. The tendon defect, ranging from 3 to 16cm in length, was reconstructed with an iliotibial band. The flaps ranged from 5 to 12cm in width and 8 to 18cm in length. RESULTS: All the flaps survived completely and no donor site complications were observed. In two flaps there was a small area of distal necrosis which was healed by dressing changes. The mean follow-up time was 14.2 months (from 6 to 24 months). Limb function was assessed using the Maryland Foot Score. The excellent and good rate was 92%. CONCLUSIONS: We believe a free ALT flap is ideal for reconstruction of massive soft tissue defects at the foot and ankle in children and an iliotibial band from the same donor site can be used for reconstruction of a damaged tendon.

Photoinduced diffraction grating in hybrid artificial molecule.

Photoinduced diffraction grating is theoretically investigated in a three-level ladder-type hybrid artificial molecule comprised of a semiconductor quantum dot (SQD) and a metal nanoparticle (MNP). The SQD and the MNP are coupled via the Coulomb interaction. The probe absorption vanishes under the action of a strong coupling field, indicating an effect of electromagnetically induced transparency (EIT). Based on this EIT effect, diffraction grating is achievable when a standing-wave coupling field is applied. It turns out that the efficiency of diffraction grating is greatly improved due to the existence of the MNP. Furthermore, the diffraction efficiency can be controlled by tuning the interaction strength between the SQD and the MNP. Nearly pure phase grating is obtained, showing high transmissivity and high diffraction efficiency up to 33%.

Historical variation of structural novelty in a natural product library.

To evaluate the potential of natural products as novel structure suppliers, a historical analysis was performed on the structural novelty of a natural product library, viz., the Chapman & Hall/CRC Dictionary of Natural Products. The results show that although the unexplored natural product universe is still ample, it is more and more difficult to find novel agents from nature, with the discovery probability of novel structures and scaffolds being lower than 50% in the near future, which mainly results from the intrinsic redundancy of natural products and, thus, is unlikely to be reversed merely through technical progresses.

High-precision and efficient alignment of cubic phase plate based on Zernike polynomials.

Cubic phase plates are key optical elements in the wavefront coding system. Unlike for traditional optical lenses, their free-form shape makes it difficult to determine the correct position. This article presents a precise and efficient alignment method using Zernike polynomials by analytical analysis and numerical simulation and considering position deviations of rotation and offset. In addition, to help determine what kind of position deviation exists, the relationship between position deviation and introduced surface errors is analyzed and demonstrated. The proposed method is especially useful for optical design and manufacture. It improves the accuracy of measurements by eliminating error resulting from misplacement. An optical test system using a phase shift interferometer and the result of a cubic phase plate is demonstrated.

[Effect of beta-catenin on the activation of hepatic stellate cells induced by transforming growth factor-beta1].

OBJECTIVE: To investigate the effect of beta-catenin on the activation of hepatic fibrosis by transforming growth factor-beta 1 (TGFbeta1). METHODS: The recombinant expression plasmids pcDNA3.1(+)-beta-catenin and pEGFP-N1 were cotransfected into cultured HSC-T6 cells. The expression of smad3, beta-catenin and alpha-SMA, beta-catenin protein in TGFbeta1 treated HSC-T6 cells were detected by RT-PCR and Western-blot. RESULTS: The expression of smad3 and beta-catenin in the co-transfected cells was higher than that in the untransfected cells (smad3 mRNA were 0.642 +/- 0.011, 0.501 +/- 0.021, 0.511 +/- 0.019, 0.356 +/- 0.017, respectively, F = 135.304, P < than 0.05. beta-catenin mRNA were 0.783 +/- 0.021, 0.543 +/- 0.033, 0.538 +/- 0.024, 0.212 +/- 0.019, respectively, F = 267.340, P < than 0.05. smad3 protein were 0.892 +/- 0.012, 0.124 +/- 0.011, 0.130 +/- 0.021, 0.003 +/- 0.001, F = 2823.813, P < l than 0.05. beta-catenin protein were 0.921 +/- 0.020, 0.210 +/- 0.010, 0.208 +/- 0.008, 0.002 +/- 0.001, respectively, F = 3440.982, P < than 0.05). The expression of beta-catenin and smad3 protein had a positive correlation with the level of alpha-SMA protein in cells (r = 0.901, P < than 0.01; r = 0.939, P < than 0.01). CONCLUSIONS: Expression of smad3/alpha-SMA/beta-catenin is increased in the cultured HSC-T6 cells transfected by beta-catenin gene, especially when the transfected cells are stimulated by TGFbeta1. Our data suggest that beta-catenin could aggravate hepatic fibrosis induced by TGFbeta1.

2-(Benzene-sulfonamido)pyridinium perchlorate.

In the title compound, C(11)H(11)N(2)O(2)S(+)·ClO(4) (-), the dihedral angle between the benzene and pyridinium rings is 87.33 (10)°. An intra-molecular N-H⋯O inter-action, with an S=O-bonded O atom as receptor, occurs in the cation. In the crystal structure, ion pairs occur, being linked by strong N-H⋯O hydrogen bonds. The perchlorate anion plays a further role in the mol-ecular packing by accepting several weak C-H⋯O inter-actions.