[Risk factors and prevention for implant treatment in patients with periodontitis]

In patients with periodontitis, due to problems of periodontal tissue infection as well as soft and hard tissues defects, it may lead to implant infection, gingival papilla loss, soft tissue recession and poor coordination with adjacent teeth. For such patients, periodontal infection should be actively controlled before dental implant therapy. In consideration of insufficient soft and hard tissues, alveolar ridge preservation and soft tissue augmentation procedure can be used to preserve or increase soft and hard tissues as much as possible. Multi-disciplinary treatment is often needed for occlusion problems and coordination with adjacent tooth. Periodontal maintenance treatment of implants and natural teeth is also necessary after implant therapy. This paper discussed these risk factors and strategies for prevention and control, in order to provide some clinical guidances for the implant treatment of periodontitis patients.

Postoperative pulmonary complications in older patients undergoing elective surgery with a supraglottic airway device or tracheal intubation

The two most commonly used airway management techniques during general anaesthesia are supraglottic airway devices and tracheal tubes. In older patients undergoing elective non-cardiothoracic surgery under general anaesthesia with positive pressure ventilation, we hypothesised that a composite measure of in-hospital postoperative pulmonary complications would be less frequent when a supraglottic airway device was used compared with a tracheal tube. We studied patients aged ≥ 70 years in 17 clinical centres. Patients were allocated randomly to airway management with a supraglottic airway device or a tracheal tube. Between August 2016 and April 2020, 2900 patients were studied, of whom 2751 were included in the primary analysis (1387 with supraglottic airway device and 1364 with a tracheal tube). Pre-operatively, 2431 (88.4%) patients were estimated to have a postoperative pulmonary complication risk index of 1-2. Postoperative pulmonary complications, mostly coughing, occurred in 270 of 1387 patients (19.5%) allocated to a supraglottic airway device and 342 of 1364 patients (25.1%) assigned to a tracheal tube (absolute difference -5.6% (95%CI -8.7 to -2.5), risk ratio 0.78 (95%CI 0.67-0.89); p < 0.001). Among otherwise healthy older patients undergoing elective surgery under general anaesthesia with intra-operative positive pressure ventilation of their lungs, there were fewer postoperative pulmonary complications when the airway was managed with a supraglottic airway device compared with a tracheal tube.

[Management of liver transplantation perioperative period in acute-on-chronic liver failure]

Acute-on-chronic liver failure (ACLF) is a potentially reversible entity that occurs in patients with chronic liver disease accompanied with or without cirrhosis and is characterized by extrahepatic organ failure and high short-term mortality. Currently, the most effective treatment method for patients with ACLF is liver transplantation; therefore, admission timing and contraindications must be emphasized. The function of vital organs such as the heart, brain, lungs, and kidneys should be actively supported and protected during the liver transplantation perioperative period in patients with ACLF. Focusing on the anesthesia management level during anesthesia selection, intraoperative monitoring, three-stage management, prevention and treatment of post-perfusion syndrome, monitoring and management of coagulation function, volume monitoring and management, and body temperature monitoring management for liver transplantation should strengthen anesthesia management. Additionally, standard postoperative intensive care treatment should be recommended, and grafts and other vital organ functions should be monitored throughout the perioperative period to promote early postoperative recovery in patients with ACLF.

Intestinal dysbacteriosis mediates the reference memory deficit induced by anaesthesia/surgery in aged mice

BACKGROUND

Postoperative cognitive dysfunction (POCD) is associated with increased morbidity and mortality and has become a major concern for patients and caregivers. POCD is most common in older patients. Previous studies demonstrated that the gut microbiome affects cognitive function and behaviour, and perioperative factors, including the operation itself, antibiotics, opioids or acid-inducing drugs, affect the gut microbiome. Thus, we hypothesised that intestinal dysbacteriosis caused by anaesthesia/surgery induces POCD.

METHODS

Tibial fracture internal fixation was performed in 18-month-old C57BL/6 mice under isoflurane anaesthesia to establish the POCD model. The Morris water maze was used to measure reference memory after anaesthesia/surgery. High-throughput sequencing of 16S rRNA from faecal samples was used to investigate changes in the abundance of intestinal bacteria after anaesthesia/surgery. To confirm the role of the gut microbiome in POCD, we pretreated mice with compound antibiotics or mixed probiotics (VSL#3). Anaesthesia/surgery impaired reference memory and induced intestinal dysbacteriosis in aged mice.

RESULTS

The 16S rRNA sequencing data revealed 37 genera (18 families) of bacteria that changed in abundance after anaesthesia/surgery. Pretreating mice with compound antibiotics or mixed probiotics (VSL#3) prevented the learning and memory deficits induced by anaesthesia/surgery. We further conducted quantitative real-time polymerase chain reaction (qRT-PCR) of 22 common types of bacteria among the 37 total types to verify the results of bacterial flora changes after anaesthesia/surgery. Numbers of 8 types of bacteria changed after anaesthesia/surgery but returned to normal after treatment with a mix of probiotics.

CONCLUSIONS

Our data suggest that deficits in reference memory induced by anaesthesia/surgery are mediated by intestinal dysbacteriosis.

Supraglottic jet oxygenation and ventilation enhances oxygenation during upper gastrointestinal endoscopy in patients sedated with propofol: a randomized multicentre clinical trial

Background

Hypoventilation is the main reason for hypoxia during upper gastrointestinal endoscopy procedures with sedation. The key to preventing hypoxia is to maintain normal ventilation during the procedure. We introduced supraglottic jet oxygenation and ventilation (SJOV) through a new Wei nasal jet tube (WNJ) to reduce the incidence of hypoxia in patients sedated with propofol during upper gastrointestinal endoscopy procedures.

Methods

In a multicentre, prospective randomized single-blinded study, 1781 outpatients undergoing routine upper gastrointestinal endoscopy who were sedated with propofol by an anaesthetist were randomized into the following three groups: the supplementary oxygen via nasal cannula group [nasal cannula oxygen: O 2 (2 litres min -1 ) was administered via a nasal cannula]; the supplementary oxygen via WNJ group [WNJ oxygen: O 2 (2 litres min -1 ) was administered through a WNJ]; and the SJOV via WNJ group (WNJ SJOV: SJOV was administered via WNJ) at three centres from March 2015 to July 2016. The primary outcome of interest was the incidence of hypoxia (peripheral oxygen saturation of 75-89%). Other adverse events were also recorded.

Results

Supraglottic jet oxygenation and ventilation decreased the incidence of hypoxia from 9 to 3% ( P <0.0001). No severe hypoxia occurred in the WNJ SJOV group, one instance occurred in the WNJ oxygen group, and two instances were observed in the nasal cannula oxygen supply control group. Supraglottic jet oxygenation and ventilation-related minor adverse events increased significantly within 1 min after the procedure but decreased 30 min later.

Conclusions

The use of SJOV during upper gastrointestinal endoscopy for patients who are sedated with propofol reduces the incidence of hypoxia, with minor and tolerable adverse events. Supraglottic jet oxygenation and ventilation has a favourable risk-to-benefit ratio and may improve patient safety.

Clinical trial registration

NCT02436018.

Functional up-regulation of P2X3 receptors in dorsal root ganglion in a rat model of bone cancer pain

BACKGROUND

Cancer-induced bone pain remains a clinical challenge due to the poor understanding of the mechanisms. Recent study revealed extracellular adenosine triphosphate (ATP) and P2X receptors may be implicated in nociceptive signalling under cancer pain state. Therefore, here we investigated the potential role of P2X(3) receptor in a rat model of bone cancer pain.

METHODS

Walker 256 tumour cells were inoculated into the left tibia of Wistar rats. The model was verified by X-ray imaging, pathology and behaviour examinations. The expression of P2X(3) receptors in dorsal root ganglia (DRG) was examined. Functional significance of altered P2X(3) receptors was investigated by measuring influx upon α,β-meATP stimulation in acutely dissociated DRG neurons. Moreover, A-317491, an antagonist of P2X(3) receptors, was administrated intrathecally or locally to evaluate its analgesia effect in the cancer pain animals.

RESULTS

The P2X(3) receptor was up-regulated for about 50% in DRG neurons in rats with bone cancer at both protein and mRNA levels and correlated with the pain behaviour in bone cancer rats. A 51.9% increase of α,β-me ATP (10 μM, for 4 s) evoked transient response currents and a higher percentage of neurons responsive to the application of α,β-me ATP was detected in bone cancer rats. Intrathecal or local injection of A-317491 significantly attenuated pain behaviour induced by bone cancer.

CONCLUSIONS

These results suggest that the P2X(3) receptor is functionally up-regulated in DRG in cancer rats. P2X(3) receptor is a promising target for therapeutic intervention in cancer patients for pain management.

Scientific Publications in International Anaesthesiology Journals: A 10-Year Survey

Significant growth has been seen in the field of anaesthesiology in recent decades. The current geographic distribution of the publications on anaesthesia research may be different from ten years ago. We performed this literature survey to examine the national origin of articles published in international anaesthesiology journals and to evaluate their contribution to anaesthesia research. Articles published in 18 major anaesthesiology journals from 2000 to 2009 were identified from the PubMed database and the Science Citation Index. A total of 30,191 articles were published in the selected 18 journals from 2000 to 2009. The country responsible for the largest number of articles was the United States of America (29.4%), followed by the United Kingdom, Germany, Japan, Canada, Australia and France. Denmark, Switzerland and Finland had the largest number of articles per capita. Anesthesia & Analgesia published the most number of articles from 2000 to 2009, followed by Anesthesiology, Pain and the British Journal of Anaesthesia. The numbers of clinical studies and randomised controlled trials decreased markedly from 2000 to 2009.

A comparison of liver function after hepatectomy with inflow occlusion between sevoflurane and propofol anesthesia

BACKGROUND

In this study, we compared liver function tests after hepatectomy with inflow occlusion as a function of propofol versus sevoflurane anesthesia.

METHODS

One hundred patients undergoing elective liver resection with inflow occlusion were randomized into a sevoflurane group or a propofol group. General anesthesia was induced with 3 μg/kg fentanyl, 0.2 mg/kg cisatracurium, and target-controlled infusion of propofol, set at a plasma target concentration of 4 to 6 μg/mL, or sevoflurane initially started at 8%. Anesthesia was maintained with target-controlled infusion of propofol (2-4 μg/mL) or sevoflurane (1.5%-2.5%). The primary end point was postoperative liver injury assessed by peak values of liver transaminases.

RESULTS

Transaminase levels peaked between the first and the third postoperative day. Peak alanine aminotransferase was 504 and 571 U/L in the sevoflurane group and the propofol group, respectively. Peak aspartate aminotransferase was 435 U/L after sevoflurane and 581 U/L in the propofol group. There were no significant differences in peak alanine aminotransferase or peak aspartate aminotransferase between groups. Other liver function tests including bilirubin and alkaline phosphatase, and peak values of white blood cell counts and creatinine, were also not different between groups.

CONCLUSIONS

Sevoflurane and propofol anesthetics resulted in similar patterns of liver function tests after hepatectomy with inflow occlusion. These data suggest that the 2 anesthetics are equivalent in this clinical context.

The effects of obstructive jaundice on the pharmacodynamics of propofol: does the sensitivity of intravenous anesthetics change among icteric patients?

BACKGROUND

Some studies suggest that certain clinical symptoms of cholestasis, such as fatigue and pruritus, result from altered neurotransmission. Patients with obstructive jaundice also have labile blood pressure and heart rate. In the present study, the authors investigated whether obstructive jaundice affects a patient's sensitivity to hypnotics and the haemodynamic profile of propofol.

METHODS

Thirty-six ASA physical status I/II/III patients with serum total bilirubin (TBL) from 7.8 to 362.7 micromol/l scheduled for bile duct surgery were recruited. A computer-controlled propofol infusion programmed for effect site target was used to rapidly attain and maintain sequential increase of the compartment concentration (from 1 to 3 microg/ml). Each target-controlled concentration was maintained for about 12 min, and arterial blood samples were drawn for propofol concentration determination. The bispectral index (BIS) and mean arterial pressures (MAP) were used as indices of the propofol effect. The relation between the concentration and the effects was described by the Hill equation. The pharmacodynamic parameters were optimized using a nonlinear mixed-effect model.

RESULTS

TBL was not a significant covariate of EC(50) for the pharmacodynamic model. For BIS and MAP, the parameters of the pharmacodynamic model were E(max)=75.77%, EC(50)=2.34 microg/ml, and gamma=1.82, and E(max)=47.83%, EC(50)=1.49 microg/ml, and gamma=1.88, respectively.

CONCLUSIONS

We demonstrated that obstructive jaundice with serum TBL from 7.8 to 362.7 micromol/l had no effect on propofol pharmacodynamics observed by BIS and MAP.

Inhibition of cell proliferation and arrest of cell cycle progression by blocking chloride channels in human laryngeal cancer cell line Hep-2

Chloride channel (ClC) is involved in normal physiological processes and pathology of various diseases. Although it is recognized that blockade of ClC inhibits the cell proliferation, it is not well understood the potential function of ClC in laryngeal cancer. In this study, we investigated the effect of the ClC inhibitor on cell proliferation, cell cycle progression in human laryngeal cancer cell line Hep-2, as well as the effect on the phosphorylation levels of ERK1/2 and AKT1. In this study crystal violet method was used to study the effect of the ClC inhibitor, 5-nitro-2-(3-phenylpropylamino) benzoic acid, NPPB, on Hep-2 cell proliferation. The impaction of the inhibitor on the cell cycle distribution was investigated by the flow cytometry (FCM). Western blot was performed to measure the phosphorylation levels of ERK1/2 and AKT1. Our data indicated ClC played an important role in Hep-2 cell proliferation and cell cycle. NPPB inhibited Hep-2 cell proliferation when compared with the controls. Blockade of ClC arrested cell cycle progression and suppressed the phosphorylation of ERK1/2 and AKT1 in Hep-2 cells by inhibition of cell proliferation by CIC inhibitor (NPPB) could be through arresting cell cycle progression, which is probably by suppressing phosphorylation of ERK1/2 and AKT1.

NMR analysis of cleaved Escherichia coli thioredoxin (1-73/74-108) and its P76A variant: cis/trans peptide isomerization

Inspection of high resolution three-dimensional (3D) structures from the protein database reveals an increasing number of cis-Xaa-Pro and cis-Xaa-Yaa peptide bonds. However, we are still far from being able to predict whether these bonds will remain cis upon single-site substitution of Pro or Yaa and/or cleavage of a peptide bond close to it in the sequence. We have chosen oxidized Escherichia coli thioredoxin (Trx), a member of the Trx superfamily with a single alpha/beta domain and cis P76 to determine the effect of single-site substitution and/or cleavage on this isomer. Standard two-dimensional (2D) NMR analysis were performed on cleaved Trx (1-73/74-108) and its P76A variant. Analysis of the NOE connectivities indicates remarkable similarity between the secondary and supersecondary structure of the noncovalent complexes and Trx. Analysis of the 2D version of the HCCH-TOCSY and HMQC-NOESY-HMQC and 13C-filtered HMQC-NOESY spectra of cleaved Trx with uniformly 13C-labeled 175 and P76 shows surprising conservation of both cis P76 and packing of 175 against W31. A similar NMR analysis of its P76A variant provides no evidence for cis A76 and shows only subtle local changes in both the packing of 175 and the interstrand connectivities between its most protected hydrophobic strands (beta2 and beta4). Indeed, a molecular simulation model for the trans P76A variant of Trx shows only subtle local changes around the substitution site. In conclusion, cleavage of R73 is insufficient to provoke cis/trans isomerization of P76, but cleavage and single-site substitution (P76A) favors the trans isomer.

Recognition between disordered polypeptide chains from cleavage of an alpha/beta domain: self-versus non-self-association

Advances in structural biology have provoked a re-evaluation of the biological significance of the disordered state of proteins. We believe that the rules that govern structure, stability and kinetics in the molecular recognition between disordered polypeptide chains can be elucidated by studying processes that couple association with folding. The reassembly of single domain proteins by fragment complementation provides an excellent opportunity to study them. Since almost the complete sequence is available, although not on a single chain, most of the complementary fragments are expected to reassemble. However, that happens not to be the case. We have chosen E. coli thioredoxin (Trx), a small, single alpha/beta-domain protein, as a model system to study the effect of the site and number of cleavages on the reassembly of complementary fragments. We have shown at atomic detail the reassembly after cleavage of a loop (1-73, 74-108) and after cleavage of an alpha-helix (1-37, 38-108). Although both sets of fragments produce native-like complexes, there are clear differences in the interface geometry, apparent stability of the folded state and mechanism of association/folding: (i) the apparent equilibrium dissociation constant for 1-37/38-108 complex (4 microM) is higher than the one for 1-73/74-108 complex (49 nM), (ii) the apparent rate constants of non-self-association are similar (about 10(3) M-1s-1), and (iii) only the 1-37 fragment self-associates under these experimental conditions. Here the competition between self- and non-self-association leads to an apparently less stable 1-37/38-108 complex.

A rapid method for detection of flavivirus antigens: staphylococcal co-agglutination test using monoclonal antibodies to Japanese encephalitis virus

Staphylococcus aureus rich in protein A when coated with monoclonal antibodies (MoAb) to Japanese encephalitis virus (JEV) gave a highly specific reaction with flavivirus antigens. The bacteria coated with JEV species-specific MoAb gave a strong co-agglutination with fifty-six JEV isolates from various parts of China, but no co-agglutination with Murray Valley encephalitis (MVE) and Kunjin (Kun) virus antigens. The flavivirus- and subgroup-specific MoAbs were reactive with MVE and Kun, as well as with the majority of the JEV strains. Blocking test with homologous MoAbs abolished co-agglutination further confirming its specificity. Numerous virus particles were observed on the surface of MoAb-coated staphylococci under the electron microscope after co-agglutination. The test appeared rapid, specific, simple to perform, and useful for rapid detection and identification of flaviviruses.

A simplified new method for the identification of arboviruses: virus detection using enzyme immunoassay on cultured cells

A simple new method is reported for the identification of arbovirus isolates and the titration of arboviruses. Horseradish peroxidase conjugated Staphylococcus aureus protein A was used for the indirect staining of virus antigens grown in an Aedes albopictus cell line, C6/36 cells. Thirty-five isolates from Culex tritaeniorhynchus mosquitoes were examined by this method and 20 of these were identified as Japanese encephalitis virus (JEV). These results were confirmed by immunofluorescent assay and plaque neutralization test. Comparative titration of JEV, Murray Valley encephalitis (MVE) and Kunjin viruses showed that this method was as sensitive as the chick embryo plaque assay. Specific enzymatic reactions on these virus-infected cells began to appear before day 3 and reached the end-point on day 5 post-infection of C6/36 cells, whereas the cytopathic effect (CPE) appeared about 2 days later than the positive enzymatic reactions. Fixation with 10% formalin for 0.5-8 h did not damage the positive reaction in infected cells and did not increase the background colour of uninfected cells.