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The development and application of ambient ionization and miniature mass spectrometry have become the current research hotpot, which is capable of rapid, sensitive, on-site and real-time analysis of samples without complex sample pretreatment. In this study, a rapid on-site method using dielectric barrier discharge ionization (DBDI) and a miniature mass spectrometer was developed for the screening of prohibited substances in spray cosmetics. Helium gas was used as the discharge gas and 1 mm thick quartz glass was used as the dielectric barrier in a custom-made DBDI ion source. The two brass electrodes were 10 mm apart, both mounted outside the quartz glass. The inner diameter of the glass tube at the gas inlet and outlet was 1 mm. When the experiment was carried out, the DBDI ion source was placed 3 cm in front of the discontinuous atmospheric pressure interface (DAPI) of the miniature mass spectrometer. The spray cosmetic sample was placed 8 cm directly above the plasma beam generated by the DBDI. Without any sample pretreatment, once the sample spray valve was pressed, the sample microdroplets generated in the vertical direction collided with the plasma beam generated in the horizontal direction. In the region between the DBDI and the miniature mass spectrometer, the target substances were ionized by energy and charge transfer with the plasma beam, and then detected by the miniature mass spectrometer. The helium flow rate was set at an optimum value of 220 mL/min by a gas mass flow controller. Coupled with the miniature mass spectrometer, four prohibited colorants in disposable hair dye spray and four prohibited fragrances in spray lotion were screened. Based on the observed signal-to-noise ratio (S/N) of the most intense MS/MS fragment peaks and using S/N=3 as a criterion, the limits of detection (LODs) were estimated between 10 and 50 μg/kg for the eight prohibited substances. The entire analysis procedure could be completed within 1 min. The simplified analytical protocol can effectively solve the disadvantages of traditional analytical methods that are cumbersome and time-consuming. The proposed method is simple, rapid, sensitive, efficient, and suitable for rapid on-site screening of prohibited substances in spray cosmetics.

Hyperbolic electrode linear ion trap is a good choice as the mass analyzer of miniaturized ion trap mass spectrometer for the reason that it has a compact size and excellent performance. However, ions are ejected from both opposite directions along the x-axis for existing hyperbolic electrode linear ion trap, which means that the ion detection efficiency could not be higher than 50% if only one ion detector is employed in the miniaturized ion trap mass spectrometer. This symmetrical structure significantly influences the analysis performance of hyperbolic electrode linear ion trap and limits the application at miniaturized ion trap mass spectrometer. Therefore, in order to further improve the ion detection efficiency of the ion trap, an asymmetric hyperboloid linear ion trap structure was proposed. By optimizing the unidirectional stretching distance Δra of the x-axis electrode in the direction of ion ejection after the optimization to the stretching distances Δrx of both x axis electrodes, a reasonable asymmetric radio frequency electric field was introduced for improving ion unidirectional ejection efficiency. The samples used in the simulation experiments were ions with m/z 609, 610 and 611. The internal electric field distribution, ion motion trajectory and simulated mass spectra peak of the asymmetric hyperboloid linear ion trap for different electrode structures were analyzed by simulation software SIMION and AXSIM. Then the ion unidirectional ejection efficiency and mass resolution were calculated, and the data were drawn as line charts. The simulation results showed that on the basis of the optimized symmetrical hyperboloid ion trap structure, whose x-axis electrodes were both stretched by Δrx=0.9 mm, an ion unidirectional ejection efficiency of over 90% and a mass resolution over 5 100 for m/z 610 were achieved by optimizing the parameters such as AC frequency and scanning rate, when one of the x-axis electrodes was unidirectionally stretched by Δra=0.8 mm. In addition, under the condition of ions with large m/z 1 890, a mass resolution up to 10 590 and an ion unidirectional ejection efficiency of 93.3% were achieved when Δra=0.7 mm. It proved that the asymmetric hyperboloid linear ion trap with the optimized geometric structure could greatly improve the ion detection efficiency with only one ion detector under the guarantee of high mass resolution, which had a significant advantage for developing miniaturized ion trap mass spectrometer in the future. On the whole, the research could provide a theoretical foundation for further investigations, but there were still some problems to be solved, such as the actual processing, assembly and experiment.

Abstract Background While great attention has been paid to motor and cognitive impairments in children with neonatal Hypoxic-Ischemic Encephalopathy (HIE), sleep related circadian rhythm problems, although commonly present, are often neglected. Subsequently, no early clinical indicators have been reported to correlate with sleep-related circadian dysfunction during development. Methods In this study, we first analyzed patterns of the amplitude integrated electroencephalogram (aEEG) in a cohort of newborns with various degrees of HIE. Next, during follow-ups, we collected information of sleep and circadian related problems in these patients and performed correlation analysis between aEEG parameters and different sleep/circadian disorders. Results A total of 101 neonates were included. Our results demonstrated that abnormal aEEG background pattern is significantly correlated with circadian rhythmic (r = 0.289, P = 0.01) and breathing issues during sleep (r = 0.237, P = 0.037). In contrast, the establishment of sleep–wake cycle (SWC) showed no correlation with sleep/circadian problems. Detailed analysis showed that summation of aEEG score, along with low base voltage (r = 0.272, P = 0.017 and r = -0.228, P = 0.048, respectively), correlates with sleep circadian problems. In contrast, background pattern (BP) score highly correlates with sleep breathing problem (r = 0.319, P = 0.004). Conclusion Abnormal neonatal aEEG pattern is correlated with circadian related sleep problems. Our study thus provides novel insights into predictive values of aEEG in sleep-related circadian problems in children with HIE.

Our previous studies have demonstrated that TP53-induced glycolysis and apoptosis regulator (TIGAR) can protect neurons after cerebral ischemia/reperfusion. However, the role of TIGAR in neonatal hypoxic-ischemic brain damage (HIBD) remains unknown. In the present study, 7-day-old Sprague-Dawley rat models of HIBD were established by permanent occlusion of the left common carotid artery followed by 2-hour hypoxia. At 6 days before induction of HIBD, a lentiviral vector containing short hairpin RNA of either TIGAR or gasdermin D (LV-sh_TIGAR or LV-sh_GSDMD) was injected into the left lateral ventricle and striatum. Highly aggressively proliferating immortalized (HAPI) microglial cell models of in vitro HIBD were established by 2-hour oxygen/glucose deprivation followed by 24-hour reoxygenation. Three days before in vitro HIBD induction, HAPI microglial cells were transfected with LV-sh_TIGAR or LV-sh_GSDMD. Our results showed that TIGAR expression was increased in the neonatal rat cortex after HIBD and in HAPI microglial cells after oxygen/glucose deprivation/reoxygenation. Lentivirus-mediated TIGAR knockdown in rats markedly worsened pyroptosis and brain damage after hypoxia/ischemia in vivo and in vitro. Application of exogenous nicotinamide adenine dinucleotide phosphate (NADPH) increased the NADPH level and the glutathione/oxidized glutathione ratio and decreased reactive oxygen species levels in HAPI microglial cells after oxygen/glucose deprivation/reoxygenation. Additionally, exogenous NADPH blocked the effects of TIGAR knockdown in neonatal HIBD in vivo and in vitro. These findings show that TIGAR can inhibit microglial pyroptosis and play a protective role in neonatal HIBD. The study was approved by the Animal Ethics Committee of Soochow University of China (approval No. 2017LW003) in 2017.

Circadian rhythm disorder is a common, but often neglected, consequence of neonatal hypoxic-ischemic brain damage (HIBD). However, the underlying molecular mechanisms remain largely unknown. We previously showed that, in a rat model of HIBD, up-regulation of microRNA-325 (miR-325) in the pineal gland is responsible for the suppression of Aanat, a key enzyme involved in melatonin synthesis and circadian rhythm regulation. To better understand the mechanism by which miR-325 affects circadian rhythms in neonates with HIBD, we compared clinical samples from neonates with HIBD and samples from healthy neonates recruited from the First Affiliated Hospital of Soochow University (Dushuhu Branch) in 2019. We found that circulating miR-325 levels correlated positively with the severity of sleep and circadian rhythm disorders in neonates with HIBD. Furthermore, a luciferase reporter gene assay revealed that LIM homeobox 3 (LHX3) is a novel downstream target of miR-325. In addition, in miR-325 knock-down mice, the transcription factor LHX3 exhibited an miR-325-dependent circadian pattern of expression in the pineal gland. We established a neonatal mouse model of HIBD by performing double-layer ligation of the left common carotid artery and exposing the pups to a low-oxygen environment for 2 hours. Lhx3 mRNA expression was significantly down-regulated in these mice and partially rescued in miR-325 knockout mice subjected to the same conditions. Finally, we showed that improvement in circadian rhythm-related behaviors in animals with HIBD was dependent on both miR-325 and LHX3. Taken together, our findings suggest that the miR-325-LHX3 axis is responsible for regulating circadian rhythms and provide novel insights into the identification of potential therapeutic targets for circadian rhythm disorders in patients with neonatal HIBD. The clinical trial was approved by Institutional Review Board of Children’s Hospital of Soochow University (approval No. 2015028) on July 20, 2015. Animal experiments were approved by Animal Care and Use Committee, School of Medicine, Soochow University, China (approval No. XD-2016-1) on January 15, 2016.

Objective To explore the characteristics, risk factors of postoperative infections for patients with growth hormone (GH)⁃secreting pituitary adenoma after endoscopic transsphenoidal surgery, and to share the experience of diagnosis and treatment of these patients. Methods A total of 122 patients with GH⁃secreting pituitary adenoma who underwent endoscopic transsphenoidal surgery were included from January 2016 to October 2019, and the data of postoperative body temperature, postoperative infection and related possible risk factors were analyzed. Results The incidence of postoperative infections in patients with acromegaly was significantly higher than that with other types of pituitary adenomas [9.84% (12/122) vs. 3.77% (8/212), P=0.025]. Central nervous system infection (7 cases) and bacteremia (4 cases) were the most common types of infections. Gram ⁃ negative bacilli were predominant (10 cases). The postoperative peak body temperature of patients with infections (12 cases) was significantly higher (P = 0.000) and appeared later than non ⁃infectious group (110 cases, P= 0.000). Multivariate Logistic analysis showed that intraoperative cerebrospinal fluid leakage (OR = 5.520, 95% CI:1.193-25.551; P = 0.029) and female (OR = 7.804, 95% CI: 1.088 - 55.948;P = 0.041) patients were major risk factors for postoperative infections. Conclusions For patients with GH ⁃ secreting pituitary adenoma who underwent endoscopic surgery, postoperative infections were uncommon but serious complication, especially for females, for those who experienced intraoperative cerebrospinal fluid leakage and postoperative peak body temperature delayed. Early identification and timely treatment are very important. Empirical anti ⁃ infective treatment should cover Gram ⁃ negative bacteria. Repair using autologous fat fascia and nasoseptal flap may reduce the incidence of postoperative infections in patients who suffered severe cerebrospinal fluid leakage. DOI：10.3969/j.issn.1672⁃6731.2020.03.013

Neonatal hypoxic-ischemic brain damage (HIBD) often results in various neurological deficits. Among them, a common, yet often neglected, symptom is circadian rhythm disorders. Previous studies revealed that the occurrence of cysts in the pineal gland, an organ known to regulate circadian rhythm, is associated with circadian problems in children with HIBD. However, the underlying mechanisms of pineal dependent dysfunctions post HIBD remain largely elusive. Here, by performing 10x single cell RNA sequencing, we firstly molecularly identified distinct pineal cell types and explored their transcriptome changes at single cell level at 24 and 72 h post neonatal HIBD. Bioinformatic analysis of cell prioritization showed that both subtypes of pinealocytes, the predominant component of the pineal gland, were mostly affected. We then went further to investigate how distinct pineal cell types responded to neonatal HIBD. Within pinealocytes, we revealed a molecularly defined β to α subtype conversion induced by neonatal HIBD. Within astrocytes, we discovered that all three subtypes responded to neonatal HIBD, with differential expression of reactive astrocytes markers. Two subtypes of microglia cells were both activated by HIBD, marked by up-regulation of Ccl3. Notably, microglia cells showed substantial reduction at 72 h post HIBD. Further investigation revealed that pyroptosis preferentially occurred in pineal microglia through NLRP3-Caspase-1-GSDMD signaling pathway. Taken together, our results delineated temporal changes of molecular and cellular events occurring in the pineal gland following neonatal HIBD. By revealing pyroptosis in the pineal gland, our study also provided potential therapeutic targets for preventing extravasation of pineal pathology and thus improving circadian rhythm dysfunction in neonates with HIBD.

Transient receptor potential melastatin 2 (TRPM2) is an important ion channel that represents a potential target for treating injury caused by cerebral ischemia. However, it is unclear whether reducing TRPM2 expression can help repair cerebral injury, and if so what the mechanism underlying this process involves. This study investigated the protective effect of reducing TRPM2 expression on pheochromocytoma (PC12) cells injured by oxygen-glucose deprivation (OGD). PC12 cells were transfected with plasmid encoding TRPM2 shRNAS, then subjected to OGD by incubation in glucose-free medium under hypoxic conditions for 8 hours, after which the cells were allowed to reoxygenate for 24 hours. Apoptotic cells, mitochondrial membrane potentials, reactive oxygen species levels, and cellular calcium levels were detected using flow cytometry. The relative expression of C-X-C motif chemokine ligand 2 (CXCL2), NACHT, LRR, and PYD domain–containing protein 3 (NALP3), and caspase-1 were detected using fluorescence-based quantitative reverse transcription-polymerase chain reaction and western blotting. The rates of apoptosis, mitochondrial membrane potentials, reactive oxygen species levels, and cellular calcium levels in the TRPM2-shRNA + OGD group were lower than those observed in the OGD group. Taken together, these results suggest that TRPM2 knockdown reduces OGD-induced neuronal injury, potentially by inhibiting apoptosis and reducing oxidative stress levels, mitochondrial membrane potentials, intracellular calcium concentrations, and NLRP3 inflammasome activation.

Vascular dementia (VD) a heterogenous group of brain disorders in which cognitive impairment is attributable to vascular risk factors and cerebrovascular disease. A common phenomenon in VD is a dysfunctional cerebral regulatory mechanism associated with insufficient cerebral blood flow, ischemia and hypoxia. Under hypoxic conditions oxygen supply to the brain results in neuronal death leading to neurodegenerative diseases including Alzheimer's (AD) and VD. In conditions of hypoxia and low oxygen perfusion, expression of hypoxia-inducible factor 1 alpha (HIF-1α) increases under conditions of low oxygen and low perfusion associated with upregulation of expression of hypoxia-upregulated mitochondrial movement regulator (HUMMR), which promotes anterograde mitochondrial transport by binding with trafficking protein kinesin 2 (TRAK2). Schisandrin B (Sch B) an active component derived from Chinese herb Wuweizi prevented β-amyloid protein induced morphological alterations and cell death using a SH-SY5Y neuronal cells considered an AD model. It was thus of interest to determine whether Sch B might also alleviate VD using a rat bilateral common carotid artery occlusion (BCAO) dementia model. The aim of this study was to examine the effects of Sch B in BCAO on cognitive functions such as Morris water maze test and underlying mechanisms involving expression of HIF-1α, TRAK2, and HUMMR levels. The results showed that Sch B improved learning and memory function of rats with VD and exerted a protective effect on the hippocampus by inhibition of protein expression of HIF-1α, TRAK2, and HUMMR factors. Evidence indicates that Sch B may be considered as an alternative in VD treatment. [ABSTRACT FROM AUTHOR]

Abstract Background Previous studies have indicated edema may be involved in the pathophysiology following hypoxic-ischemic encephalopathy (HIE), and melatonin may exhibit neuro-protection against brain insults. However, little is known regarding the mechanisms that involve the protective effects of melatonin in the brain and peripheral tissues after HIE. The present study aimed to examine the effects of melatonin on multiple organs, and the expression of edema related proteins in a neonatal rat model of hypoxic-ischemic brain damage (HIBD). Methods One hundred ninety-two neonatal rats were randomly divided into three subgroups that underwent a sham surgery or HIBD. After the HIBD or sham-injury, the rats received an intraperitoneal injection of melatonin or an equal volume vehicle, respectively. We investigated the effects of melatonin on brain, kidney, and colon edema via histological examination and the expression of edema related proteins, including AQP-4, ZO-1 and occludin, via qPCR and western blot. Results Our data indicated (1) Melatonin reduced the histological injury in the brain and peripheral organs induced by HIBD as assessed via H-E staining and transmission electron microscopy. (2) Melatonin alleviated the HIBD-induced cerebral edema characterized by increased brain water content. (3) HIBD induced significant changes of edema related proteins, such as AQP-4, ZO-1 and occludin, and these changes were partially reversed by melatonin treatment. Conclusions These findings provide substantial evidence that melatonin treatment has protective effects on the brain and peripheral organs after HIBD, and the edema related proteins, AQP4, ZO-1, and occludin, may indirectly contribute tothe mechanism of the edema protection by melatonin.

Autophagy has been suggested to participate in the pathology of hypoxic-ischemic brain damage (HIBD). However, its regulatory role in HIBD remains unclear and was thus examined here using a rat model. To induce HIBD, the left common carotid artery was ligated in neonatal rats, and the rats were subjected to hypoxia for 2 hours. Some of these rats were intraperitoneally pretreated with the autophagy inhibitor 3-methyladenine (10 mM in 10 μL) or the autophagy stimulator rapamycin (1 g/kg) 1 hour before artery ligation. Our findings demonstrated that hypoxia-ischemia-induced hippocampal injury in neonatal rats was accompanied by increased expression levels of the autophagy-related proteins light chain 3 and Beclin-1 as well as of the AMPA receptor subunit GluR1, but by reduced expression of GluR2. Pretreatment with the autophagy inhibitor 3-methyladenine blocked hypoxia-ischemia-induced hippocampal injury, whereas pretreatment with the autophagy stimulator rapamycin significantly augmented hippocampal injury. Additionally, 3-methyladenine pretreatment blocked the hypoxia-ischemia-induced upregulation of GluR1 and downregulation of GluR2 in the hippocampus. By contrast, rapamycin further elevated hippocampal GluR1 levels and exacerbated decreased GluR2 expression levels in neonates with HIBD. Our results indicate that autophagy inhibition favors the prevention of HIBD in neonatal rats, at least in part, through normalizing GluR1 and GluR2 expression.

Rationale: Improving the analytical performance of linear ion traps (LITs) is crucial for the advancement of high‐performance LIT mass spectrometers. In this study, a double resonant excitation method was employed in an asymmetric LIT to achieve high ion unidirectional ejection efficiency and enhanced mass resolution. Methods: The asymmetric trapping field was generated by stretching one x electrode with a distance α. The double resonant excitation was achieved by applying an alternating voltage out of phase and a supplementary alternating voltage in phase to the x and y electrode pairs of the LIT, respectively. Numerical simulations of ion trajectories were performed to validate the effectiveness of this method. Results: The mass resolution of the asymmetric LIT with double resonant excitation could be improved to ~3800, which was over two times compared to that with only dipolar resonant excitation, while both reached ~90% in ion unidirectional ejection efficiency. Conclusions: By employing the double resonant excitation method, the mass resolution could be improved significantly in the asymmetric LIT, while maintaining a considerably high ion unidirectional ejection efficiency. This method might provide a general solution for enhancing ion detection efficiency and mass resolution of LIT mass spectrometers. [ABSTRACT FROM AUTHOR]