Medial Septal Glutamatergic Neurons Modulate States of Consciousness during Sevoflurane Anesthesia in Mice.

BACKGROUND: Multiple neural structures involved in maintaining wakefulness have been found to promote arousal from general anesthesia. The medial septum is a critical region that modulates arousal behavior. This study hypothesized that glutamatergic neurons in the medial septum play a crucial role in regulating states of consciousness during sevoflurane general anesthesia. METHODS: Adult male mice were used in this study. The effects of sevoflurane anesthesia on neuronal activity were determined by fiber photometry. Lesions and chemogenetic manipulations were used to study the effects of the altered activity of medial septal glutamatergic neurons on anesthesia induction, emergence, and sensitivity to sevoflurane. Optogenetic stimulation was used to observe the role of acute activation of medial septal glutamatergic neurons on cortical activity and behavioral changes during sevoflurane-induced continuous steady state of general anesthesia and burst suppression state. RESULTS: The authors found that medial septal glutamatergic neuronal activity decreased during sevoflurane anesthesia induction and recovered in the early period of emergence. Chemogenetic activation of medial septal glutamatergic neurons prolonged the induction time (mean ± SD, hM3Dq-clozapine N-oxide vs. hM3Dq-saline, 297.5 ± 60.1 s vs. 229.4 ± 29.9 s, P < 0.001, n = 11) and decreased the emergence time (53.2 ± 11.8 s vs. 77.5 ± 33.5 s, P = 0.025, n = 11). Lesions or chemogenetic inhibition of these neurons produced the opposite effects. During steady state of general anesthesia and deep anesthesia-induced burst suppression state, acute optogenetic activation of medial septal glutamatergic neurons induced cortical activation and behavioral emergence. CONCLUSIONS: The study findings reveal that activation of medial septal glutamatergic neurons has arousal-promoting effects during sevoflurane anesthesia in male mice. The activation of these neurons prolongs the induction and accelerates the emergence of anesthesia.

Comparison of different weight-based scalars of remimazolam tosylate for anesthesia induction in obese patients: study protocol for a prospective, controlled trial.

BACKGROUND: The physiologic and anthropometric characteristics changes associated with obesity may result in the alternation of pharmacologic management. Remimazolam tosylate is a new type of ultra-short-acting benzodiazepine with stable context-sensitive half-time (CSHT) and no lipid accumulation after long-time infusion. Although remimazolam tosylate has potential advantages for the induction and maintenance of anesthesia in obese patients, the appropriate induction dosing scalars among obese patients are unknown. Therefore, we aim to compare the different weight-based scalars for dosing remimazolam tosylate of anesthesia induction among obese patients. METHODS/DESIGN: The study will be performed as a prospective, single-center, double-blind, controlled clinical trial. The study design is a comparison of remimazolam tosylate requirements based on total body weight (TBW) or lean body weight (LBW) to reach a Modified Observer's Assessment of Alertness and Sedation (MOAA/S) score of 0 among obese subjects (BMI ≥ 35 kg/m2). Another twenty normal-weight subjects (18.5 kg/m2 ≤ BMI < 25 kg/m2) will be enrolled as a control group, whose induction dose is scaled based on TBW. The infusion rate of remimazolam tosylate during induction is 12 mg/kg/h in all groups. DISCUSSION: Results of the present study will provide evidence of dose scalar of remimazolam tosylate to guide the clinical practice of anesthesia induction in obese patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR220005664. Registered on 9 February 2022, https://www.chictr.org.cn/showproj.aspx?proj=151150 .

A Predictive Model of Major Postoperative Respiratory Adverse Events in Pediatric Patients Undergoing Rigid Bronchoscopy for Exploration and Foreign Body Removal.

Background: No nomogram has been established to predict the incidence of major postoperative respiratory adverse events (mPRAEs) in children undergoing rigid bronchoscopy for airway foreign bodies (AFB) removal and exploration of the airway, though some studies have confirmed the risk factors. Methods: 1214 pediatric patients (≤3 years old) undergoing rigid bronchoscopy for AFB from June 2014 to December 2020 were enrolled in this study. The primary outcome was the occurrence of mPRAEs, including laryngospasm and bronchospasm. Following that, a nomogram prediction model for the mPRAEs was developed. Results: The incidence of mPRAEs was 84 (6.9%) among 1214 subjects. American Society of Anesthesiologists physical status (ASA-PS), intraoperative desaturation (SpO2 < 90%), procedural duration and ventilatory approach were all independent risk factors of mPRAEs. The area under the receiver operating characteristic curve (AUC) value of the nomogram for predicting mPRAEs was 0.815 (95% CI: 0.770-0.861), and the average AUC for ten-fold cross-validation was 0.799. These nomograms were well calibrated by Hosmer-Lemshow (p = 0.607). Decision curve analysis showed that the nomogram prediction model is effective in clinical settings. Conclusions: Combining ASA-PS, intraoperative desaturation, procedural duration, and ventilatory approach, the nomogram model is adequate for predicting the risk of developing mPRAEs, followed by rigid bronchoscopy for AFB removal and exploration.

Extracting keyframes of breast ultrasound video using deep reinforcement learning.

Ultrasound (US) plays a vital role in breast cancer screening, especially for women with dense breasts. Common practice requires a sonographer to recognize key diagnostic features of a lesion and record a single or several representative frames during the dynamic scanning before performing the diagnosis. However, existing computer-aided diagnosis tools often focus on the final diagnosis process while neglecting the influence of the keyframe selection. Moreover, the lesions could have highly-irregular shapes, varying sizes, and locations during the scanning. The recognition of diagnostic characteristics associated with the lesions is challenging and also faces severe class imbalance. To address these, we proposed a reinforcement learning-based framework that can automatically extract keyframes from breast US videos of unfixed length. It is equipped with a detection-based nodule filtering module and a novel reward mechanism that can integrate anatomical and diagnostic features of the lesions into keyframe searching. A simple yet effective loss function was also designed to alleviate the class imbalance issue. Extensive experiments illustrate that the proposed framework can benefit from both innovations and is able to generate representative keyframe sequences in various screening conditions.

Photodynamic effects on Fonsecaea monophora conidia and RAW264.7 in vitro.

Chromoblastomycosis (CBM), one of the neglected tropical diseases, is hard to cure and easy to be recurrent. Many studies suggest that macrophage is involved in the pathogenesis of chromoblastomycosis and the fungicidal effect of 5-Aminolaevulinic Acid-Based Photodynamic Therapy (ALA-PDT) against F. monophora (one of the main causative agent of chromoblastomycosis) has shown great promise. However, the fungicidal ability of ALA-PDT to F. monophora is still controversial and the molecular mechanism and immune mechanism of ALA-PDT against F. monophora remains poorly documented. In the present work, ALA (5-Aminolaevulinic Acid) was employed as photosensitizer and a LED device was served as light source to investigate photodynamic effect on F. monophora conidia under different ALA-PDT conditions in a direct way. RAW264.7 was stimulated by conidia treated with ALA-PDT to study the photodynamic effect on F. monophora conidia in an indirect way. It was observed that ALA-PDT can inactivate F. monophora conidia directly in a concentration-dependent and dose-dependent manner. RAW264.7 was activated indirectly by photodynamically treated conidia. ALA-PDT can enhance the fungicidal ability of RAW264.7 and protect it from Infection-induced apoptosis in an indirect way. ROS generated by photodynamic treated conidia is associated with mitochondrial-related apoptosis in RAW264.7.The results of this investigation demonstrated that ALA-PDT inactivate F. monophora through two way: directly killing F. monophora conidia through ROS-dependent Oxidative damage; activating RAW264.7 in an indirect way.

Genetic transformation of fungi.

Transferring DNA into cells is an essential research method for molecular cloning and gene function studies. As molecular biology and materials physics develop, more and more new transformation methods have been applied to mammalian cells. Some techniques have been successfully developed for several types of fungi, but their efficiencies are extremely low. To better study the functional genes of fungi, and to improve the characteristics of fungi in an easy, safe and reliable way, many investigations have been conducted to effectively develop such technologies for a wide variety of species and to increase the efficiency and reproducibility of genetic transformation. The objective of this paper is to review the latest development of transformation methods used for the genetic transformation of fungi, including several promising transformation approaches, together with their advantages and drawbacks, which may open up novel methods for fungi research.

Sevoflurane inhibits embryonic stem cell self-renewal and subsequent neural differentiation by modulating the let-7a-Lin28 signaling pathway.

The commonly used inhalational anesthetic, sevoflurane, can cause toxicity to the central nervous system of the developing fetus. Lin28 has been reported to regulate let-7a, thereby modulating embryo development, neurodegeneration, and even neuron-related tumorigenesis. We demonstrate that pregnant mice receiving sevoflurane treatment during the early stage of pregnancy give birth to fewer offspring presenting a lower birth weight. We have also treated mouse embryonic stem cells (mESCs) with sevoflurane for 6 h and determined that mESCs self-renewal is repressed, and that differentiation is initiated earlier than in controls. We have induced neural differentiation in the treated mESCs and determined that their neurogenesis is weakened. Furthermore, sevoflurane upregulates the level of let-7a, which might repress mESC self-renewal by directly targeting the Lin28 3'-untranslated region. Lin28 overexpression attenuates the influence of sevoflurane or of let-7a on the self-renewal of mESCs and their subsequent neural differentiation. The let-7a inhibitor also abolishes the influence of sevoflurane. Thus, the let-7a-Lin28 pathway is involved in the sevoflurane-induced inhibition of ESC self-renewal and subsequent neurogenesis. Our study demonstrates the molecular mechanism underlying the side effects of sevoflurane during early development, laying the foundation for studies on the safe and reasonable usage of other inhalational anesthetics.

Detection of Talaromyces marneffei from Fresh Tissue of an Inhalational Murine Pulmonary Model Using Nested PCR.

Penicilliosis marneffei, often consecutive to the aspiration of Talaromyces marneffei (Penicillium marneffei), continues to be one of the significant causes of morbidity and mortality in immunocompromised patients in endemic regions such as Southeast Asia. Improving the accuracy of diagnosing this disease would aid in reducing the mortality of associated infections. In this study, we developed a stable and reproducible murine pulmonary model that mimics human penicilliosis marneffei using a nebulizer to deliver Talaromyces marneffei (SUMS0152) conidia to the lungs of BALB/c nude mice housed in exposure chamber. Using this model, we further revealed that nested PCR was sensitive and specific for detecting Talaromyces marneffei in bronchoalveolar lavage fluid and fresh tissues. This inhalation model may provide a more representative analysis tool for studying the development of penicilliosis marneffei, in addition to revealing that nested PCR has a predictive value in reflecting pulmonary infection.

Isoflurane Damages the Developing Brain of Mice and Induces Subsequent Learning and Memory Deficits through FASL-FAS Signaling.

Background. Isoflurane disrupts brain development of neonatal mice, but its mechanism is unclear. We explored whether isoflurane damaged developing hippocampi through FASL-FAS signaling pathway, which is a well-known pathway of apoptosis. Method. Wild type and FAS- or FASL-gene-knockout mice aged 7 days were exposed to either isoflurane or pure oxygen. We used western blotting to study expressions of caspase-3, FAS (CD95), and FAS ligand (FASL or CD95L) proteins, TUNEL staining to count apoptotic cells in hippocampus, and Morris water maze (MWM) to evaluate learning and memory. Result. Isoflurane increased expression of FAS and FASL proteins in wild type mice. Compared to isoflurane-treated FAS- and FASL-knockout mice, isoflurane-treated wild type mice had higher expression of caspase-3 and more TUNEL-positive hippocampal cells. Expression of caspase-3 in wild isoflurane group, wild control group, FAS/FASL-gene-knockout control group, and FAS/FASL-gene-knockout isoflurane group showed FAS or FASL gene knockout might attenuate increase of caspase-3 caused by isoflurane. MWM showed isoflurane treatment of wild type mice significantly prolonged escape latency and reduced platform crossing times compared with gene-knockout isoflurane-treated groups. Conclusion. Isoflurane induces apoptosis in developing hippocampi of wild type mice but not in FAS- and FASL-knockout mice and damages brain development through FASL-FAS signaling.

The miR-29b-Sirt1 axis regulates self-renewal of mouse embryonic stem cells in response to reactive oxygen species.

Endogenous reactive oxygen species (ROS) control is important for the maintenance of self-renewal of embryonic stem (ES) cells. Although miRNAs have been found to be critically involved in the regulation of the self-renewal, whether miRNAs can regulate the signaling axis to control ROS in ES cells is unclear. Here we show that miR-29b specifically regulates the self-renewal of mouse ES cells in response to ROS generated by antioxidant-free culture. Sirt1 is the direct target of miR-29b and can also make mES cells sensitive to ROS and regulate the self-renewal of mES cells during the response of ROS. We further found that Sirt1 could attenuate the miR-29b function in regulating mES cells' self-renewal in response to ROS. Our results determined that miR-29b-Sirt1 axis regulates self-renewal of mES cells in response to ROS.