A miniaturized mesoscope for the large-scale single-neuron-resolved imaging of neuronal activity in freely behaving mice.

Exploring the relationship between neuronal dynamics and ethologically relevant behaviour involves recording neuronal-population activity using technologies that are compatible with unrestricted animal behaviour. However, head-mounted microscopes that accommodate weight limits to allow for free animal behaviour typically compromise field of view, resolution or depth range, and are susceptible to movement-induced artefacts. Here we report a miniaturized head-mounted fluorescent mesoscope that we systematically optimized for calcium imaging at single-neuron resolution, for increased fields of view and depth of field, and for robustness against motion-generated artefacts. Weighing less than 2.5 g, the mesoscope enabled recordings of neuronal-population activity at up to 16 Hz, with 4 µm resolution over 300 µm depth-of-field across a field of view of 3.6 × 3.6 mm2 in the cortex of freely moving mice. We used the mesoscope to record large-scale neuronal-population activity in socially interacting mice during free exploration and during fear-conditioning experiments, and to investigate neurovascular coupling across multiple cortical regions.

Can urinary excretion rate of 8-isoprostrane and malonaldehyde predict postoperative cognitive dysfunction in aging?

Oxidative stress has been associated with mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, little is known about oxidative stress in postoperative cognitive dysfunction (POCD) in aging. The aim of this study was to investigate urinary excretion rate of 8-isoprostane:creatinine (U8-isoPG:Cr) and malonaldehyde:creatinine (UMDA:Cr) to predict short-term POCD in elderly patients undergoing general and orthopedic surgery. 72 patients aged above 65 years were enrolled in this prospective observational study. Each patient underwent cognitive testing to determine POCD performed by an investigator before surgery and 1 week after surgery. Morning urine was collected at baseline, 1, 2, and 7 days postoperatively. U8-isoPG was performed using enzymelinked immunosorbent assay (ELISA), and UMDA levels were measured by chemiluminescence detection. Creatinine levels were also analyzed if differences in the oxidative biomarkers were observed in the urine creatinine concentration. (1). Of 72 patients who completed cognitive testing, postoperative cognitive dysfunction was detected in 29.2 % (n = 21) of patients in 7 days. (2) U8-isoPG:Cr levels in 7 days postoperatively were significantly higher in POCD patients compared with the non-POCD group (p = 0.01). When measuring change from baseline, U8-isoPG:Cr levels were higher than that of control groups (p = 0.01). (3) UMDA:Cr levels were significantly elevated in 1 and 2 days postoperatively in both groups (p < 0.05). U8-isoPG:Cr level seems to be a valuable marker to detect lipid peroxidation early in POCD patients. However, it will also be important to take into account or reduce potential confounders to improve the identification of changes in the status of oxidative stress as a marker for POCD.

Cerebral cortex and hippocampus neural interaction during vagus nerve stimulation under in vivo large-scale imaging.

Objective: The purpose of this study was to study mechanisms of VNS modulation from a single neuron perspective utilizing a practical observation platform with single neuron resolution and widefield, real-time imaging coupled with an animal model simultaneously exposing the cerebral cortex and the hippocampus. Methods: We utilized the observation platform characterized of widefield of view, real-time imaging, and high spatiotemporal resolution to obtain the neuronal activities in the cerebral cortex and the hippocampus during VNS in awake states and under anesthesia. Results: Some neurons in the hippocampus were tightly related to VNS modulation, and varied types of neurons showed distinct responses to VNS modulation. Conclusion: We utilized such an observation platform coupled with a novel animal model to obtain more information on neuron activities in the cerebral cortex and the hippocampus, providing an effective method to further study the mechanisms of therapeutic effects modulated by VNS.

[Construction of strains for bioconversion of steroid key intermediates and intelligent industrial production].

Steroidal hormone pharmaceuticals are the second largest class of medicines after antibiotics. At present, the initial materials of the steroidal industry have shifted from sapogenins, which were extracted from plants of the genus Dioscore to phytosterols. As a byproduct of soybean oil production, phytosterols are readily available and of low prices. Androstenedione (AD), androstadiendione (ADD), 9α-hydroxy-androstenedione (9α-OH-AD) and a series of key intermediates used in the synthesis of steroidal pharmaceuticals can be produced from phytosterols by microbial transformation. Nevertheless, due to the long metabolic pathways, the byproducts and the complex regulation, traditional microbial screening, mutagenizing methods and the oil-water biphasic transformation systems are no longer suitable for current industrial production. A new generation strains for the production of key steroidal pharmaceutical intermediates have been constructed and an intelligent production process has been jointly developed by us and Zhejiang Xianju Junye Pharmaceutical Co. Ltd.. Taking these products and processes as an example, this article reviews the improvement of strains for the production of steroidal pharmaceutical intermediates and the development of biotransformation process on an industrial scale. With the development of synthetic biology, it is expected to develop a new generation of intermediates which are more suitable for the synthesis of steroidal medicines. Moreover, de novo biosynthesis the steroidal active pharmaceutical ingredients from glucose is also expected. The application of these new-generation strains constructed by biotechnology (BT) in modern factories based on informatization and intelligent technology (IT) will be more efficient and greener, and create remarkable social and economic values.

Simultaneous Observation of Mouse Cortical and Hippocampal Neural Dynamics under Anesthesia through a Cranial Microprism Window.

The fluorescence microscope has been widely used to explore dynamic processes in vivo in mouse brains, with advantages of a large field-of-view and high spatiotemporal resolution. However, owing to background light and tissue scattering, the single-photon wide-field microscope fails to record dynamic neural activities in the deep brain. To achieve simultaneous imaging of deep-brain regions and the superficial cortex, we combined the extended-field-of-view microscopy previously proposed with a novel prism-based cranial window to provide a longitudinal view. As well as a right-angle microprism for imaging above 1 mm, we also designed a new rectangular-trapezoidal microprism cranial window to extend the depth of observation to 1.5 mm and to reduce brain injury. We validated our method with structural imaging of microglia cells in the superficial cortex and deep-brain regions. We also recorded neuronal activity from the mouse brains in awake and anesthesitized states. The results highlight the great potential of our methods for simultaneous dynamic imaging in the superficial and deep layers of mouse brains.

Real-time brain-wide multi-planar microscopy for simultaneous cortex and hippocampus imaging at the cellular resolution in mice.

Interactions between the cerebral cortex and the deep cerebellar nuclei play important roles in cognitive processes. However, conventional microscopes fail to dynamically record cellular structures in distinct brain regions and at different depths, which requires high resolution, large field of view (FOV), and depth of field (DOF). Here we propose a single-photon excited fluorescence microscopy technique that performs simultaneous cortex and hippocampus imaging, enabled by a customized microscope and a chronic optical window. After we implant a glass microwindow above the hippocampus, the surface of the hippocampus is shifted to the superficial plane. We demonstrate that the proposed technique is able to image cellular structures and blood vessel dynamics in the cortex and the hippocampus in in vivo experiments, and is compatible with various mesoscopic systems.

Effect of Acute Hypercapnia on Outcomes and Predictive Risk Factors for Complications among Patients Receiving Bronchoscopic Interventions under General Anesthesia.

BACKGROUND: The aim of this study is to investigate the effect of acute hypercapnia on surgery outcomes among patients receiving bronchoscopic interventions under general anesthesia. Furthermore, independent predictive factors for surgery complications were analyzed. METHOD: A total of 323 patients with airway stenosis were enrolled in this retrospective study. Each patient underwent interventional rigid bronchoscopy under general anesthesia. Arterial blood gas (ABG) was measured intraoperatively. In light of PaCO2 levels in ABG, patients were divided into three groups: Group C (control) (PaCO2:≤ 60 mmHg), Group M (moderate) (PaCO2:61-100 mmHg), and Group S (severe) (PaCO2: >100 mmHg). Parameters, including PaO2 levels and recovery delays, were compared across three groups. Complications among patients receiving bronchoscopic interventions were evaluated as well. Independent predictive factors for surgery related complications were analyzed by multivariable regression method. RESULTS: Significant differences in weight (p=0.04), ASA IV (p=0.008), dyspnea index (p=0.003),COPD (p=0.02), dynamic airway collapse (p=0.002), severe stenosis severity (p=0.02), and stenosis locations among three groups were observed. Mild (PaCO2:~60 mmHg) to moderate (PaCO2:60-100 mmHg) hypercapnia was not associated with delayed recovery, whereas severe hypercapnia (PaCO2:>100 mmHg) was associated with delayed recovery, as well as declined PaO2 (p=0.00) and elevated blood glucose levels (p=0.00). The complications of bronchoscopic interventions included postoperative congestive heart failure (14 cases, 4.3%), tracheorrhagia (8 cases, 2.5%), delayed recovery (19 cases, 5.9%), and transfers to ICU after surgery (10 cases, 3.1%). The multivariable regression analysis showed that procedure duration (p=0.003), lobectomy (p=0.007), dynamic airway collapse (p=0.01), severe bronchial stenosis (p=0.01) and hypercapnia (p=0.02) were independent predictive factors for surgery related complications. CONCLUSIONS: Acute hypercapnia lower than 100 mmHg was not associated with detrimental consequences, whereas severe hypercapnia (PaCO2: >100 mmHg) was associated with lower levels of PaO2. Hypercapnia was an independent predictive factor for bronchoscopic intervention complication, which may help physicians to optimize the therapeutic choices.

[Optimization of hydroxylating DHEA to 7alpha,15alpha-diOH-DHEA by compound mutation and fermentation optimization].

Combined with method of ketoconazole resistance screening, a 7alpha,15alpha-diOH-DHEA high-producing mutant Colletotrichum lini ST-1 was obtained by compound mutation of NTG and low energy N+ ion beam implantation. With the substrate concentration of 10 g/L DHEA, the molar yield of 7alpha,15alpha-diOH-DHEA reached 34.2%, increased by 46.2% than that of the original strain. Then we optimized the medium. First, Plackett-Burman design was used to evaluate the effects of medium components on molar yield of the product. Results show that glucose, yeast extract and MgSO4 x 7H2O were the important parameters for the biotransformation process. Subsequently, the path of steepest ascent was used to approach the optimal levels. To obtain the optimal levels, central composite design and response surface analysis were carried out. The optimal medium was as follows (g/L): glucose 26.34, yeast extract 12.15, corn flour 3.00, FeSO4 x 7H2O 0.015, MgSO4 x 7H2O 0.14, KH2PO4 0.90. Under the optimal conditions, the molar yield of 7alpha,15alpha-diOH-DHEA reached 49.3%, which was 44.2% higher than that of using the medium before optimization.