Establishment and application of cricothyrotomy in vivo.

BACKGROUND: Cricothyrotomy is a procedure performed to establish an airway in critical airway events. It is performed only rarely and anesthesiologists are often unprepared when called upon to perform it. This study aimed to simulate cricothyrotomy using pig larynx and trachea models to help anesthesiologists master cricothyrotomy and improve the ability to establish cricothyrotomy quickly. METHODS: The porcine larynx and trachea were dissected and covered with pigskin to simulate the structure of the anterior neck of a human patient. An animal model of cricothyrotomy was established. Forty anesthesiologists were randomly divided into four groups. Each physician performed three rounds of cricothyrotomy, and recorded the time to accomplish each successful operation. After training the cricothyrotomy procedure, a questionnaire survey was conducted for the participating residents using a Likert scale. The participants were asked to score the utility of the training course on a scale of 1 ((minimum) to 5 ((maximum). RESULTS: Through repeated practice, compared with the time spent in the first round of the operation (67 ± 29 s), the time spent in the second round of the operation (47 ± 21 s) and the time spent in the third round of the operation (36 ± 11 s) were significantly shortened (P < 0.05). Results of the survey after training were quite satisfied, reflecting increased the ability of proficiency in locating the cricothyroid membrane and performing a surgical cricothyrotomy. CONCLUSION: The porcine larynx and trachea model is an excellent animal model for simulating and practicing cricothyrotomy, helping anesthesiologists to master cricothyrotomy and to perform it proficiently when required.

Selective fluorescence quenching of papain-Au nanoclusters by self-polymerization of dopamine.

In this paper, we synthesized a papain-stabilized fluorescent Au nanocluster (NC) probe and studied its interaction with dopamine. As fluorescence of papain-Au NCs is quenched in the presence of dopamine under alkaline conditions, we were able to establish a simple, selective analytical method for dopamine determination. By studying the fluorescence lifetime and dynamic light scattering of the NCs before and after interaction with dopamine, we found that this fluorescence quenching mechanism was possibly due to dopamine self-polymerization that produced polydopamine that cross-linked papain-Au NCs. Based on this new phenomenon, we proposed a highly selective analytical method for dopamine detection. Other small organic molecules, such as amino acids, ascorbic acid and uric acid did not interfere with dopamine detection. Dopamine in the range 20-100 µM can be linearly detected by the fluorescence quenching ratio of gold nanoclusters. Dopamine detection could be visually realized by watching color changes of papain-Au NCs under UV light or daylight, as both fluorescence and absorption of the papain-Au NCs changed during dopamine polymerization.

Propofol Regulates the TLR4/NF-κB Pathway Through miRNA-155 to Protect Colorectal Cancer Intestinal Barrier.

Surgery for colorectal cancer (CRC) can cause damage to the intestinal mucosal barrier and lead to bacterial invasion. This study mainly analyzed whether propofol (PPF) could protect the intestinal mucosal barrier damage caused by CRC surgery, and explored its molecular mechanism. A mouse CRC model was constructed using azomethane and dextran sulfate sodium. During anesthesia, continuous intravenous injection of PPF was used for intervention. The influences of PPF on intestinal mucosal permeability and bacterial invasion were detected. The levels of microRNA (miR)-155, Toll-like receptor 4 (TLR4)/NF-κB in the intestinal mucosa, and the location of miR-155 were detected by fluorescence in situ hybridization (FISH). Mouse macrophages were used to analyze the regulation of miR-155 on the secretion of inflammatory cytokines through the TLR4/NF-κB pathway. PPF treatment promoted the expression of tight junction protein in the intestinal mucosa, protected the intestinal barrier, inhibited the translocation of intestinal bacteria, and increased the level of the beneficial bacterium Lactobacillus on the mucosal surface. In addition, PPF treatment could inhibit the expression of miR-155, TLR4/NF-KB, and reverse inflammatory response. miR-155 was expressed in macrophages of intestinal mucosa tissue. Overexpression of miR-155 promoted the nuclear translocation of NF-κB and the expression of inflammatory cytokines in macrophages. The use of VIPER to inhibit TLR4 reversed the pro-inflammatory effects of miR-155. PPF might inhibit the activation of the NF-κB pathway by downregulating miR-155 expression, thereby reducing the secretion of inflammatory cytokines. This might be the mechanism by which PPF protected the intestinal barrier of CRC surgical model mice.

Chicken Egg White-stabilized Au Nanoclusters for Selective and Sensitive Detection of Hg(II).

In this paper, chicken egg white purchased from a local market without further purification was directly used to prepare fluorescent gold nanoclusters through a one-step, simple, fast and green synthesis approach for analytical purposes. The as-prepared chicken egg white stabilized gold nanocluster probe has strong red fluorescence emission, which can be quenched by mercury ions and copper ions sensitively. By using an ethylenediaminetetraacetate (EDTA) masking method, mercury ions in the range from 0.60 to 10 µM can be linearly detected with the limit of detection (LOD, 3σ) of 0.510 µM in the presence of equivalent copper ions. Since the preparation of a chicken egg white stabilized gold nanocluster probe is fast, easy and cheap, this selective analytical method for mercury pollution monitoring in environmental waters may be widely used in daily life by ordinary people.