[Research progress of optical coherence tomography in the airway]

Optical coherence tomography (OCT) is a specialized optical imaging technique with a history of more than 30 years, known as'optical biopsy' because of its high resolution and high sensitivity. OCT has been used in the airway for more than 20 years, and researchers have explored and improved the imaging methods of OCT in the airway, focusing mainly on expanding the imaging site and enriching the imaging content. In terms of broadening the imaging site, it covers the airway from generation 0 to 9. In terms of enriching imaging content, additional assessment of airway wall blood vessels, airway smooth muscle, fibrous tissue, and airway compliance can be performed. It plays an important role in the study of various respiratory diseases. Therefore, this paper mainly summarized the exploration of the imaging site and content of airway OCT as follows.

Measurement of Hyperfine Structure and the Zemach Radius in ^{6}Li^{+} Using Optical Ramsey Technique

We investigate the 2^{3}S_{1}-2^{3}P_{J} (J=0, 1, 2) transitions in ^{6}Li^{+} using the optical Ramsey technique and achieve the most precise values of the hyperfine splittings of the 2^{3}S_{1} and 2^{3}P_{J} states, with smallest uncertainty of about 10 kHz. The present results reduce the uncertainties of previous experiments by a factor of 5 for the 2^{3}S_{1} state and a factor of 50 for the 2^{3}P_{J} states, and are in better agreement with theoretical values. Combining our measured hyperfine intervals of the 2^{3}S_{1} state with the latest quantum electrodynamic (QED) calculations, the improved Zemach radius of the ^{6}Li nucleus is determined to be 2.44(2) fm, with the uncertainty entirely due to the uncalculated QED effects of order mα^{7}. The result is in sharp disagreement with the value 3.71(16) fm determined from simple models of the nuclear charge and magnetization distribution. We call for a more definitive nuclear physics value of the ^{6}Li Zemach radius.

Contribution of activating lateral hypothalamus-lateral habenula circuit to nerve trauma-induced neuropathic pain in mice

Neuropathic pain, a severe clinical symptom, significantly affects the quality of life in the patients. The molecular mechanisms underlying neuropathic pain have been the focus of research in recent decades; however, the neuronal circuit-mediated mechanisms associated with this disorder remain poorly understood. Here, we report that a projection from the lateral hypothalamus (LH) glutamatergic neurons to the lateral habenula (LHb), an excitatory LH-LHb neuronal circuit, participates in nerve injury-induced nociceptive hypersensitivity. LH glutamatergic neurons are activated and display enhanced responses to normally non-noxious stimuli following chronic constriction injury. Chemogenetic inhibition of LH glutamatergic neurons or excitatory LH-LHb circuit blocked CCI-induced nociceptive hypersensitivity. Activation of the LH-LHb circuit led to augmented responses to mechanical and thermal stimuli in mice without nerve injury. These findings suggest that LH neurons and their triggered LH-LHb circuit participate in central mechanisms underlying neuropathic pain and may be the targets for the treatment of this disorder.

A role of GABAA receptor α1 subunit in the hippocampus for rapid-acting antidepressant-like effects of ketamine

Ketamine can produce rapid-acting antidepressant effects in treatment-resistant patients with depression. Although alterations in glutamatergic and GABAergic neurotransmission in the brain play a role in depression, the precise molecular mechanisms in these neurotransmission underlying ketamine's antidepressant actions remain largely unknown. Mice exposed to FSS (forced swimming stress) showed depression-like behavior and decreased levels of GABA (γ-aminobutyric acid), but not glutamate, in the hippocampus. Ketamine increased GABA levels and decreased glutamate levels in the hippocampus of mice exposed to FSS. There was a correlation between GABA levels and depression-like behavior. Furthermore, ketamine increased the levels of enzymes and transporters on the GABAergic neurons (SAT1, GAD67, GAD65, VGAT and GAT1) and astrocytes (EAAT2 and GAT3), without affecting the levels of enzymes and transporters (SAT2, VGluT1 and GABA_AR γ2) on glutamatergic neurons. Moreover, ketamine caused a decreased expression of GABA_AR α1 subunit, which was specifically expressed on GABAergic neurons and astrocytes, an increased GABA synthesis and metabolism in GABAergic neurons, a plasticity change in astrocytes, and an increase in ATP (adenosine triphosphate) contents. Finally, GABA_AR antagonist bicuculline or ATP exerted a rapid antidepressant-like effect whereas pretreatment with GABA_AR agonist muscimol blocked the antidepressant-like effects of ketamine. In addition, pharmacological activation and inhibition of GABA_AR modulated the synthesis and metabolism of GABA, and the plasticity of astrocytes in the hippocampus. The present data suggest that ketamine could increase GABA synthesis and astrocyte plasticity through downregulation of GABA_AR α1, increases in GABA, and conversion of GABA into ATP, resulting in a rapid-acting antidepressant-like action. This article is part of the Special Issue on 'Ketamine and its Metabolites'.

[Development and clinical application of an adjustable digital cannulated nail guide based on Mimics software]

OBJECTIVE

To evaluate effectiveness of self-designed adjustable cannulated screw guide, and to provide an effective auxiliary tool for inverted triangular arrangement of compression cannulated screws in clinical treatment for transcervical femoral neck fractures.

METHODS

The sketch of instrument was drawn with Solidworks software, and physical product was obtained after production. The data were obtained by Mimics software. Combined with the guide, it was first used on 22 cadaveric bones, 22 dry cadaveric bones, including 12 males and 10 females. Then the distribution of guide pins was evaluated by X-ray film. The anatomical size and screw distance of femoral head and neck were measured in different ways, and statistically compared. From January 2018 to June 2020, 45 hospitalized patients with femoral neck fracture were selected and divided into new guide group (22 patients) and free hand nail group (23 patients) according to whether the instrument was used or not. The clinical data and operation conditions between two groups were recorded and compared.

RESULTS

The anatomical data of X-ray, three-dimensional and physical measurement were basically the same, whlie had no difference (P>0.05). There was no significant difference between physical measurement and three-dimensional measurement (P>0.05). The distance between screws and needle entry point was designed as an isosceles triangle(r=0.992 8, P<0.000 1), but due to the existence of femoral anteversion and torsion angle, it was an approximate isosceles triangle in the femoral neck (r=0.824 1, P<0.000 1). The patients between two groups were followed up for an average of 2 years. There was no significant difference in the number of fluoroscopy and puncture between new guide group and free hand nail group(P>0.05). The screw parallelism was better and operation time was shorter which had statistically difference(P<0.05). However, there was no significant difference in final Harris score and incidence of complications between two groups(P>0.05).

CONCLUSION

Self-made femoral neck cannulated screw guide combined with preoperative planning of Mimics software is conducive to placement of inverted triangular arrangement of cannulated screws, but it still needs to be improved and followed up in the later large-scale use.

[Effectiveness and safety of robotic assisted-bronchoscopy system in locating and removing spring coils placed in the peripheral lung of beagle dogs: a pilot study]

Objective: To evaluate the effectiveness and safety of the robotic assisted bronchoscope system for localizing and removing the spring coils that placed in the peripheral lung of beagle dogs. Methods: The study was conducted from June 18th to June 20th, 2021. Metallic lung coils were placed as the simulated lesions to the periphery of the lungs of two adult male beagle dogs using a bronchoscope under general anesthesia. The navigation path was planned by the navigation function that built in the robotic bronchoscope system. After training, the doctors operated the robotic bronchoscope system to locate and remove the coils from the lung. The navigation success rate, sampling success rate, position of the coil, navigation time, sampling time, and operation time were evaluated. The damage to the airway mucosa during the operation and the vital signs of the beagles during and post-operation were accessed. Chest computerized tomography (CT) was performed post-operation to detect if there were complications such as pneumothorax and bleeding. Results: A total of 12 spring coils were successfully inserted into the two beagles. All the navigation paths of the simulated lesions were successfully planned. The navigation success rate was 12/12. The navigation time was (43.9±19.8) seconds. The distance between the tip of the flexible endoscope arm and the target point measured by the navigation system was (6.93±2.15) mm. The locations of the simulated lesions were distributed in the 6th-8th generation of bronchi. The sampling success rate was 12/12. The sampling time was (42.4±11.3) seconds. There was no pneumothorax or mediastinal emphysema after the placement of the coil. The vital signs of the beagle dogs were stable throughout the operation, and no operation-related or postoperative complications occurred. Conclusions: The robotic bronchoscope system can be used to locate and remove the spring coils from the peripheral lung of beagle dogs, and the procedure is simple and safe. It suggests that the robotic bronchoscopy system has great clinical significance in the sampling and diagnosis of peripheral lung lesions.

Malnutrition affects cholesterol paradox in coronary artery disease: a 41,229 Chinese cohort study

Background

Several studies found that baseline low LDL-C concentration was associated with poor prognosis in patients with acute coronary syndrome (ACS), which was called “cholesterol paradox”. Low LDL-C concentration may reflect underlying malnutrition, which was strongly associated with increased mortality. We objected to investigate the cholesterol paradox in patients with CAD and the effects of malnutrition.

Method

A total of 41,229 CAD patients admitted to Guangdong Provincial People's Hospital in China were included in this study from January 2007 to December 2018, and divided into two groups (LDL-C &lt;1.8 mmol/L, n=4,863; LDL-C ≥1.8 mmol/L, n=36,366). We used Kaplan-Meier method and Cox regression analyses to assess the association between LDL-C levels and long-term all-cause mortality and the effect of malnutrition.

Result

In this real-world cohort (mean age 62.94 years; 74.94% male), there were 5257 incidents of all-cause death during a median follow-up of 5.20 years [Inter-quartile range (IQR): 3.05–7.78 years]. Kaplan–Meier analysis showed that low LDL-C levels were associated with worse prognosis. After adjusting for baseline confounders (e.g., age, sex and comorbidities, etc.), multivariate Cox regression analysis revealed that low LDL-C level (&lt;1.8mmol/L) was not significantly associated with all-cause mortality (adjusted HR, 1.04; 95% CI, 0.96–1.24). After adjustment of nutritional status, risk of all-cause mortality of patients with low LDL-C level decreased (adjusted HR, 0.90; 95% CI, 0.83–0.98). In the final multivariate Cox model, low LDL-C level was related to better prognosis (adjusted HR, 0.91; 95% CI, 0.84–0.99).

Conclusion

Our results demonstrate that the cholesterol paradox persisted in CAD patients, but disappeared after accounting for the effects of malnutrition.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): the National Natural Science Foundation of China (Grant No. 81670339 and Grant No. 81970311), Cardiovascular Research Foundation Project of the Chinese Medical Doctor Association (SCRFCMDA201216)

Effect of Cedrus deodara extract on the physiochemical and sensory properties of salted meat and its action mechanism

The effect of pine needle extract from Cedrus deodara (PNE) on the quality of salted meat was reported, and its action mechanism was further investigated. With the treatment of PNE, the physicochemical properties of salted meat were improved. The peroxide value decreased from 16.18 to 6.78 mmol O₂ /kg, while the thiobarbituric acid value decreased from 0.79 to 0.40 mg MDA/kg. Moreover, the salted meat with PNE also had the better texture, color, and volatile compositions. The 0.2% PNE group showed the highest ΔE value (63.16 ± 0.56), hardness (813.5 ± 48.7 g), and volatility (45.86 ± 0.39), while the control group showed the lowest ΔE value (43.92 ± 2.13), hardness (515.8 ± 17.3 g) and volatility (29.97 ± 0.56). In addition, with the analysis of fluorescence and circular dichroism spectroscopy, the spatial structures of myofibrillar protein (MP) in salted meat were obviously changed by PNE. Meanwhile, methylconiferin, 1-O-feruloyl-β-D-glucose, nortrachelogenin, secoxyloganin, 1-O-(4-coumaroyl)-β-D-glucose and pelargonidin-3-O-glucoside were identified from PNE. Furthermore, according to the analysis of molecular docking, hydrogen bond, hydrophobic force, and electrostatic force were obtained as the main molecular forces between MP and the phenolic compounds of PNE, while arginine, glutamic acid, and glycine residues were the main binding sites. All results suggested that PNE might be a potential candidate to improve the quality of salted meat in the food industry. PRACTICAL APPLICATION: The quality deterioration of meat may not only affect its further processing and consumption but also may lead to some food safety problems. In present study, PNE exhibited the fine capability to inhibit the oxidation of meat, while it could ameliorate the texture, color, and physicochemical properties of meat due to its tightly interaction with myofibrillar protein. All result suggested that PNE could be potentially utilized to improve the quality of meat in food industry.

Abnormal theta oscillation aggravated by chronic stress in the CA1 may mediate the deterioration of fear memory impairment induced by lipopolysaccharide

Both environmental stress and immune challenge can induce abnormal neurobehavior. However, the impact of chronic stress on immune challenge-related neurobehavioral abnormalities is still controversial. Hence, we aimed to investigate the effects of chronic stress on immune challenge-related neurobehavioral abnormalities and explore the possible underlying mechanisms. During the first set of experiments, mice were reared under normal condition (NC) or chronic stress (CS) for 4 consecutive weeks. They were allocated to the following four groups: NC + normal saline (NS) group, CS + NS group, NC + lipopolysaccharide (LPS) group, and CS + LPS group. Open field, elevated plus maze, fear conditioning, novel object recognition, and forced swimming tests were performed, and their tissues were harvested. During the second set of experiments, after rearing the mice under the above conditions for 3 weeks, microelectrodes were implanted into the CA1 of the hippocampus. After recovery for 1 week under the respective environmental conditions, the mice were allocated to four groups, as in the first experiments. The basal (home cage) and task (fear conditioning)-related local field potential (LFP) were recorded. In the present study, LPS significantly induced a decrease in the freezing to context and discrimination ratio. However, only the freezing to context was further reduced by prior chronic stress. This suggested that chronic stress worsened fear memory impairment induced by acute LPS challenge. Consistent with the change in fear memory, LPS significantly decreased the expression of PV in the CA1, which was further downregulated by prior chronic stress. On the other hand, LPS inhibited the power of both basal and task-related θ oscillations in the CA1. Only the task-related θ power was further decreased by chronic stress. In conclusion, our study showed that the phenotypic loss of PV interneurons and the decrease in the power of the θ oscillation in the CA1 aggravated by chronic stress may mediate, at least in part, the deterioration of fear memory impairment induced by LPS.

Extrasynaptic CaMKIIα is involved in the antidepressant effects of ketamine by downregulating GluN2B receptors in an LPS-induced depression model

Background

A subanesthetic dose of ketamine provides rapid and effective antidepressant effects, but the molecular mechanism remains elusive. It has been reported that overactivation of extrasynaptic GluN2B receptors is associated with the antidepressant effects of ketamine and the interaction between GluN2B and calcium/calmodulin-dependent protein kinase IIα (CaMKIIα) is important for GluN2B localization and activity. Here, we tested whether changes of CaMKIIα and GluN2B are involved in the antidepressant effects of ketamine.

Methods

Lipopolysaccharide (LPS) was injected intraperitoneally (i.p.) into male C57BL/6 mice. For the interventional study, mice were administrated with ketamine (10 mg/kg, i.p.) or a CaMKIIα inhibitor KN93. Behavioral alterations were evaluated by open-field, novelty-suppressed feeding, and forced-swimming tests. Physiological functions were evaluated by the body weight and fur coat state of mice. The levels of p-CaMKIIα, CaMKIIα, p-GluN2B, GluN2B, p-CREB, CREB, BDNF, GluR1, and GluR2 in the hippocampus were detected by western blotting. The interaction between GluN2B and CaMKIIα was studied using immunoprecipitation assay and small interfering RNA (siRNA) assays. The colocalizations of GluN2B/PSD95 and p-GluN2B/PSD95 were detected by immunofluorescence. The long-term potentiation (LTP) in SC-CA1 of the hippocampus was detected by electrophysiology.

Results

LPS injection induced depression-like behaviors, which were accompanied by significant increases in extrasynaptic p-CaMKIIα expression, extrasynaptic GluN2B localization, and phosphorylation and decreases in p-CREB, BDNF, and GluR1 expressions and LTP impairment. These changes were prevented by ketamine administration. Immunoprecipitation assay revealed that LPS induced an increase in the p-CaMKIIα–GluN2B interaction, which was attenuated by ketamine administration. SiRNA assay revealed that CaMKIIα knockdown reduced the level and number of clusters of GluN2B in the cultured hippocampal neurons. KN93 administration also reduced extrasynaptic p-CaMKIIα expression, extrasynaptic GluN2B localization, and phosphorylation and exerted antidepressant effects.

Conclusion

These results indicate that extrasynaptic CaMKIIα plays a key role in the cellular mechanism of ketamine’s antidepressant effect and it is related to the downregulation of extrasynaptic GluN2B localization and phosphorylation.

Rapid ratiometric detection of Cd2+ based on the formation of ZnSe/CdS quantum dots

Developing simple and sensitive non-aggregation strategy for detecting Cd²⁺ is necessary for improving the selectivity and sensitivity of probe. Here, we establish a simple, rapid and ratiometric strategy for the recognition of Cd²⁺ based on the formation of core-shell ZnSe/CdS structure using ZnSe quantum dots (QDs). The transformation from binary ZnSe QDs to core-shell ZnSe/CdS QDs both change the elemental composition and structure of ZnSe QDs, leading to the changes in band gap of ZnSe QDs, which could be observed in the UV-vis spectra. In the detection process, ZnSe QDs only possess absorption peak at 343 nm, the formation of ZnSe/CdS after the addition of Cd²⁺ leads to the appearance of the new peak at 397 nm, while other heavy metal ions could not cause the appearance of new absorption peak. Therefore, this strategy shows good selectivity for Cd²⁺ detection. Based on this strategy, the limit of detection (LOD) for Cd²⁺ is 11 nM by UV-vis spectroscopy with a desirable relation of linearity (R² = 0.999) between A₃₉₇/A₃₄₃ and Cd²⁺ contents, which is superior to the LOD of most reported nanomaterials. The response time for Cd²⁺ detection is as short as 60 s, which is suitable for rapid detection. This ratiometric probe has also been applied to the detection of Cd²⁺ in tap water samples, the recovery of Cd²⁺ was between 94.9% and 105.6% for tap water samples, indicating the high accuracy of our ratiometric assay. Our strategy not only provided a new method for detecting Cd²⁺, but also put forward an implication that the band energy changes of QDs caused by heavy metal ions can be applied in the selective and sensitive detection of heavy metal ions.

Two new iridoid glycosides from Callicarpa nudiflora

Two new iridoid glycosides, callicoside E (1) and callicoside F (2), were isolated from the leaves of Callicarpa nudiflora. Their structures were established by one- and two-dimensional NMR spectroscopy and mass spectrometry. In an in vitro bioassay, compounds 1 and 2 showed an pronounced hepatoprotective activity against d-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.[Formula: see text].

Dysregulation of BDNF/TrkB signaling mediated by NMDAR/Ca2+/calpain might contribute to postoperative cognitive dysfunction in aging mice

Background

Postoperative cognitive decline (POCD) is a recognized clinical phenomenon characterized by cognitive impairments in patients following anesthesia and surgery, yet its underlying mechanism remains unclear. Brain-derived neurotrophic factor (BDNF) plays an important role in neuronal plasticity, learning, and memory via activation of TrkB-full length (TrkB-FL) receptors. It has been reported that an abnormal truncation of TrkB mediated by calpain results in dysregulation of BDNF/TrkB signaling and is associated with cognitive impairments in several neurodegenerative disorders. Calpains are Ca²⁺-dependent proteases, and overactivation of calpain is linked to neuronal death. Since one source of intracellular Ca²⁺ is N-methyl-d-aspartate receptors (NMDARs) related and the function of NMDARs can be regulated by neuroinflammation, we therefore hypothesized that dysregulation of BDNF/TrkB signaling mediated by NMDAR/Ca²⁺/calpain might be involved in the pathogenesis of POCD.

Methods

In the present study, 16-month-old C57BL/6 mice were subjected to exploratory laparotomy with isoflurane anesthesia to establish the POCD animal model. For the interventional study, mice were treated with either NMDAR antagonist memantine or calpain inhibitor MDL-28170. Behavioral tests were performed by open field, Y maze, and fear conditioning tests from 5 to 8 days post-surgery. The levels of Iba-1, GFAP, interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), NMDARs, calpain, BDNF, TrkB, bax, bcl-2, caspase-3, and dendritic spine density were determined in the hippocampus.

Results

Anesthesia and surgery-induced neuroinflammation overactivated NMDARs and then triggered overactivation of calpain, which subsequently led to the truncation of TrkB-FL, BDNF/TrkB signaling dysregulation, dendritic spine loss, and cell apoptosis, contributing to cognitive impairments in aging mice. These abnormities were prevented by memantine or MDL-28170 treatment.

Conclusion

Collectively, our study supports the notion that NMDAR/Ca2+/calpain is mechanistically involved in anesthesia and surgery-induced BDNF/TrkB signaling disruption and cognitive impairments in aging mice, which provides one possible therapeutic target for POCD.

[Study advances in regulation effect of Tripterygium wilfordii and its extracts on innate immune system in rheumatoid arthritis cases]

Rheumatoid arthritis( RA) is an autoimmune disease characterized by chronic and aggressive polyarthritis. The innate immunity mechanism plays a key role in the pathogenesis of RA. Tripterygium wilfordii and its extracts have regulatory effects on innate immune cells including macrophages,dendritic cells,neutrophils,mast cells,NK cells,NKT cells,etc.,as well as a variety of innate immune molecules including cytokines,adhesion molecules,patterns recognition receptor( PRR) and the complement molecules,showing a regulatory effect in the pathogenesis of RA innate immunity. In this paper,the recent domestic and foreign researches on the pathogenesis of RA with innate immunity involved were reviewed and the research status of T. wilfordii and its extracts on the regulation of innate immunity involved in RA was summarized.

Activation of β2-Adrenoceptor Attenuates Sepsis-Induced Hippocampus-Dependent Cognitive Impairments by Reversing Neuroinflammation and Synaptic Abnormalities

Sepsis-associated encephalopathy induces cognitive dysfunction via mechanisms that commonly involve neuroinflammation and synaptic plasticity impairment of the hippocampus. The β2-adrenoceptor (β2-AR) is a G-protein coupled receptor that regulates immune response and synaptic plasticity, whereas its dysfunction has been implicated in various neurodegenerative diseases. Thus, we hypothesized abnormal β2-AR signaling is involved in sepsis-induced cognitive impairment. In the present study, C57BL/6 mice were subjected to cecal ligation and puncture (CLP) to mimic the clinical human sepsis-associated encephalopathy. The levels of hippocampal β2-AR, proinflammatory cytokines tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), IL-6, cAMP-response element binding protein (CREB), brain derived neurotrophic factor (BDNF), post-synaptic density protein 95 (PSD95), and NMDA receptor 2 B subtypes (GluN2B) were determined at 6, 12, 24 h and 7 and 16 days after CLP. For the interventional study, mice were treated with β2-AR agonist clenbuterol in two ways: early treatment (immediately following CLP) and delayed treatment (on the 8th day following CLP). Neurobehavioral performances were assessed by open field and fear conditioning tests. Here, we found that hippocampal β2-AR expression was significantly decreased starting from 12 h and persisted until 16 days following CLP. Besides, sepsis mice also exhibited increasing neuroinflammation, down-regulated CREB/BDNF, decreasing PSD95 and GluN2B expression, and displayed hippocampus-dependent cognitive impairments. Notably, early clenbuterol treatment alleviated sepsis-induced cognitive deficits by polarizing microglia toward an anti-inflammatory phenotype, reducing proinflammatory cytokines including IL-1β, TNF-α, and up-regulating CREB/BDNF, PSD95, and GluN2B. Intriguingly, delayed clenbuterol treatment also improved cognitive impairments by normalization of hippocampal CREB/BDNF, PSD95, and GluN2B. In summary, our results support the beneficial effects of both early and delayed clenbuterol treatment, which suggests that activation of β2-AR has a translational value in sepsis-associated organ dysfunction including cognitive impairments.

Reduced Interhemispheric White Matter Asymmetries in Medial Temporal Lobe Epilepsy With Hippocampal Sclerosis

Mesial temporal lobe epilepsy (MTLE), one of the most common types of refractory focal epilepsy, has shown white matter abnormalities both within and beyond the temporal lobe. In particular, the white matter abnormalities in the ipsilateral hemisphere are more obvious than those in the contralateral hemisphere in MTLE, that is, the abnormalities present asymmetrical characteristics. However, very few studies have characterized the white matter microstructure asymmetry in MTLE patients specifically. Thus, we performed diffusion tensor imaging (DTI) to investigate the white matter microstructure asymmetries of patients with MTLE with unilateral hippocampal sclerosis (MTLE-HS). We enrolled 25 MTLE-HS (left MTLE-HS group, n = 13; right MTLE-HS group, n = 12) and 26 healthy controls (HC). DTI data were analyzed by tract-based spatial statistics (TBSS) to test the hemispheric differences across the entire white matter skeleton. We also conducted a two-sample paired t-test for 21 paired region of interests (ROIs) parceled on the basis of the ICBM-DTI-81 white-matter label atlas of bilateral hemispheres to test the hemispheric differences. An asymmetry index (AI) was calculated to further quantify the differences between the left and right paired-ROIs. It was found that the asymmetries of white matter skeletons were significantly lower in the MTLE-HS groups than in the HC group. In particular, the asymmetry traits were moderately reduced in the RMTLE-HS group and obviously reduced in the LMTLE-HS group. In addition, AI was significantly different in the RMTLE-HS group from the LMTLE-HS or HC group in the limbic system and superior longitudinal fasciculus (SLF). The current study found that the interhemispheric white matter asymmetries were significantly reduced in the MTLE-HS groups than in the HC group. The interhemispheric white matter asymmetries are distinctly affected in left and right MTLE-HS groups. The differences in AI among RMTLE-HS, LMTLE-HS, and HC involved the limbic system and SLF, which may have some pragmatic implications for the diagnosis of MTLE and differentiating LMTLE-HS from RMTLE-HS.

Primary vs myocutaneous flap closure of perineal defects following abdominoperineal resection for colorectal disease: a systematic review and meta-analysis

AIM

Perineal wound complications after abdominoperineal resection (APR) have become a major clinical challenge. Myocutaneous flap closure has been proposed in place of primary closure to improve wound healing. We conducted this comprehensive meta-analysis to evaluate the current scientific evidence of primary closure vs myocutaneous flap closure of perineal defects following APR for colorectal disease.

METHODS

We systematically searched the MEDLINE, Embase, PubMed, Web of Science and Cochrane Library databases to identify all relevant studies. After data extraction from the included studies, meta-analysis was performed to compare perioperative outcomes of primary closure and myocutaneous flap closure.

RESULTS

Eighteen studies with a total of 17 913 patients (16 346 primary closure vs 1567 myocutaneous flap closure) were included. We found that primary closure was significantly associated with higher total perineal wound complications (P = 0.007), major perineal wound complications (P < 0.001) and perineal wound infection (P = 0.001). On the other hand, myocutaneous flap closure takes more operation time (P < 0.001) and increases the risk of perineal wound dehiscence (P = 0.01), deep surgical site infection (P < 0.001), enterocutaneous fistulas (P = 0.03) and return to the operating room (P = 0.0005). There were no significant differences between the two groups for other outcomes.

CONCLUSIONS

This is the first systematic review with meta-analysis comparing primary closure with myocutaneous flap closure of perineal defects after APR for colorectal disease. Although taking more operation time and an increased risk of specific complications, the pooled results have validated the use of myocutaneous flaps for reducing total/major perineal wound complications. More investigations are needed to draw definitive conclusions on this dilemma.

Adipose extracellular matrix promotes skin wound healing by inducing the differentiation of adipose‑derived stem cells into fibroblasts

Fibroblasts are the major effector cells of skin wound healing. Adipose-derived stem cells can differentiate into fibroblasts under certain conditions. In the present study, it was hypothesized that adipose-derived stem cells (ADSCs) could be induced by the adipose extracellular matrix (ECM) to differentiate into fibroblasts in order to promote skin wound healing. First, flow cytometry was used to detect the ratio of fibroblasts and relative expression of the fibroblast markers cytokeratin 19 (CK19) and vimentin in ADSCs. Then, the effect of the adipose ECM during the differentiation of ADSCs into fibroblasts was investigated by detecting the total amount of collagen fibers and degree of fibrosis, and the proliferation and cell cycle of differentiated fibroblasts, using the MTT assay and flow cytometry analysis respectively. Finally, a mouse skin wound model was established and treated with PBS, ADSC suspension or ECM + ADSCs to compare wound healing rate and expression of collagen I and collagen III by immunohistochemistry. Following induction of ADSCs with the adipose ECM, more fibroblasts were found, expression of CK19 and vimentin increased, and a greater degree of fibrosis occurred, which revealed the positive effect of the adipose ECM on the differentiation of ADSCs into fibroblasts. In addition, the induced fibroblasts had enhanced proliferation activity, with more cells in the S phase and fewer in the G2/M phase. The in vivo experiment indicated that the ECM produced by the ADSCs had a faster wound healing rate and increased expression of collagen I and collagen III compared with mice injected with PBS or ADSCs alone, which verified that ADSCs induced by the adipose ECM had a positive effect on skin wound healing. The present study demonstrated that the adipose ECM in combination with ADSCs may be a novel therapeutic target for the repair of skin injury, due to the ability of the adipose ECM to induce the differentiation of ADSCs into fibroblasts and to facilitate the wound healing process.

Two new noroleanane-type triterpenoid saponins from the stems of Stauntonia chinensis

Two new noroleanane-type triterpenoid saponins, 3β,20α,24-trihydroxy-29-norolean-12-en-28-oic acid 24-O-β-L-fucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranoside (1) and 3β,20α,24-trihydroxy-29-norolean-12-en-28-oic acid 24-O-β-D-glucopyranosyl-(1→2)-[α-L-arabinopyranosyl-(1→3)]-β-D-glucopyranoside (2) were isolated from the stems of Stauntonia chinensis DC., together with three known compounds, brachyantheraoside B₂ (3), eupteleasaponin Ⅷ (4) and fargoside B (5). Their structures were elucidated by spectroscopic and chemical methods. The cytotoxic activities of compounds 1 and 2 were evaluated against five human tumor cell lines (HCT-116, HepG2, BGC-823, NCI-H1650, and A2780). Compounds 1 and 2 showed moderate cytotoxic activities toward the tested cell lines with IC₅₀ values ranging from 12.71 to 32.04 μM.

Awake tracheal intubation using combination of an Airtraq® optical laryngoscope with smartphone and video flexible endoscope: a case report

A patient with obvious difficult airway who was received awake tracheal intubation using combination of an Airtraq^® optical laryngoscope with smartphone and video flexible endoscope posted for elective surgery of tonsillectomy for OSAHS was reported. Our experiences strongly indicate that fully communication with patients, detailed preoperative assessment of airways and perfect plan, appropriate endotracheal intubation approach and devices play important roles in awake tracheal intubation in difficult airway.

Supplemented Organic and Inorganic Selenium Affects Milk Performance and Selenium Concentration in Milk and Tissues in the Guanzhong Dairy Goat

Trace amounts of selenium (Se) are essential for several organisms, and deficiencies therein have adverse effects on growth, development, and reproduction; this is particularly significant in animals raised for milk and livestock production. To study the effect of Se on Guanzhong dairy goats, their diets were supplemented with different sources (inorganic or organic) and Se concentrations (0.2 or 0.4 mg Se/kg). A non-Se-fortified basal diet served as a negative control, and a sixth treatment group received both inorganic and organic Se sources (0.2 mg Se/kg diet each). Dietary Se supplementation increased milk production, with organic Se being more effective than inorganic Se. Selenium supplementation also increased Se concentration and glutathione peroxidase activity in whole blood, with organic Se more effective than inorganic Se at the same Se concentration. With increasing Se in diets, the Se content in milk increased markedly, reaching a plateau value at day 30 in all groups, and organic Se (0.4 mg/kg diet) had the best effect. In addition, dietary Se sources and concentrations markedly affected Se concentrations in different tissues and organs. Thus, organic Se supplementation of a basal diet at 0.4 mg/kg is practically applicable for Se-enriched milk and meat production in Guanzhong dairy goats.

The interactions of CdTe quantum dots with serum albumin and subsequent cytotoxicity: the influence of homologous ligands

With spreading applications of fluorescent quantum dots (QDs) in biomedical fields in recent years, there is increasing concern over their toxicity. Among various factors, surface ligands play critical roles. Previous studies usually employed QDs with different kinds of surface ligands, but general principles were difficult to be obtained since it was hard to compare these surface ligands with varied chemical structures without common features. Herein, the physicochemical properties of two types of CdTe QDs were kept very similar, but different in the surface ligands with mercaptoacetic acid (TGA) and 3-mercaptopropionic acid (MPA), respectively. These two types of homologous ligands only had a difference in one methylene group (-CH2-). The interactions of the two types of CdTe QDs with bovine serum albumin (BSA), which was one of the main components of cell culture, were studied by fluorescence, UV-vis absorption, and circular dichroism spectroscopy. It was found that the fluorescence quenching of BSA by CdTe QDs followed a static quenching mechanism, and there was no obvious difference in the Stern-Volmer quenching constants and binding constants. The thermodynamic parameters of the two types of QDs were similar. BSA underwent conformational changes upon association with these QDs. By comparing the cytotoxicity of these two types of QDs, TGA-capped QDs were found to be less cytotoxic than MPA-capped QDs. Besides, in the presence of serum proteins, the cytotoxicity of the QDs was reduced. QDs in the absence of serum proteins had a higher internalization efficiency, compared with those in the medium with serum. To the best of our knowledge, this is a rare study focusing on surface ligands with such small variations at the biomolecular and cellular levels. These findings can provide new insights for the design and applications of QDs in complex biological media.

Impact of multiple quaternary ammonium salts on dynamic properties of BSA adsorption layer at different pH values

The interaction mechanism of multiple quaternary ammonium salts (MQAS) with bovine serum albumin (BSA) was examined by the fluorescence quenching method and circular dichroism (CD) spectra. Moreover, the effects of MQAS on the dynamic properties of BSA adsorption layers at different pH values were investigated using dilational interfacial rheology. Results show that the quenching constants increase with an increase in pH values and decrease with an increase in the experiment temperature at pH 5.3. The quenching mechanism is static quenching, and the electrostatic force dominates the interaction between MQAS and BSA at pH 5.3. Due to three positive head groups, MQAS can significantly affect the dynamic interfacial activity of BSA molecules at a relatively low concentration. At pH 4.3, the electrostatic repulsion is unfavorable for the formation of MQAS/BSA complexes. Consequently, MQAS molecules will replace BSA molecules from the interface by competitive adsorption. At the pH value above the isoelectric point of BSA, the electrostatic attraction is better for the formation of MQAS/BSA complexes, which exhibit a rapid adsorption rate and an enhanced interfacial activity. Moreover, the kinetic dependencies of interfacial dilational elasticity for the MQAS/BSA mixtures become nonmonotonous. The appearance of the maximum interfacial elasticity values can be attributed to the formation of tails and loops, which suggests that the addition of MQAS destroys the secondary and tertiary structure of protein in the bulk phase. In addition, the effects of MQAS on the secondary structure of protein were demonstrated by CD spectra.

Mechanisms of vasorelaxation induced by total flavonoids of Euphorbia humifusa in rat aorta

Euphorbia humifusa Willd. (EH), rich in flavonoids, has long been used for the treatment of bacillary dysentery and enteritis in China, and is known to have antioxidant, hypotensive and hypolipidemic properties. However, the vasorelaxant effect of total flavonoids of EH (TFEH) and action mechanisms are not clearly defined yet. The aim of the present study was to investigate the effects of TFEH on the vascular tension and its underlying mechanisms. Experiments were performed in rat thoracic aorta using the organ bath system. TFEH (0.01 - 100 μg/ml) caused a concentration-dependent vasorelaxation, which was dependent on a functional endothelium, and were significantly attenuated by inhibitors of endothelial NO synthase, its upstream signaling pathway, PI3K/Akt, and soluble guanylate cyclase, but not by blockade of K_Ca channel, K_ATP channel, cyclooxygenase, muscarinic and β-adrenergic receptors. Extracellular Ca²⁺ depletion, and pre-treatment with modulators of the store-operated Ca²⁺ entry channels, Gd³⁺ and 2-aminoethyl diphenylborinate, significantly attenuated the TFEH-induced vasorelaxation. Our findings suggest that TFEH elicit vasorelaxation via endothelium-dependent NO-cGMP pathway through activation of PI3K/Akt- and Ca²⁺-eNOS-NO signaling. Further, it is suggested that TFEH-induced activation of the NO-soluble guanylate cyclase-cGMP-protein kinase G signaling relaxes vascular smooth muscle cells through an inhibition of the L-type Ca²⁺ channel activity.

One case with dexmedetomidine-induced stuporous state in epileptic patient undergoing abdominal surgery

A 56-year-old epileptic patient underwent right hemicolectomy and cholecystectomy surgery under general endotracheal anesthesia. Anesthesia was maintained with sevoflurane, and sufentanil, rocuronium, and dexmedetomidine infusions. After the operation and confirmation of neuromuscular recovery, the patient woke from anesthesia within 15 min and successfully extubated. After the vital signs of patient were stable, the patient was transported to post anesthesia care unit (PACU). 6 h after the surgery, he fell into a stuporous state for lasting 14 h and EEG showed no epileptiform discharges. Stupor did re-occur in 2 days after operation. 36 hours after operation, all signs of the stuporous state resolved spontaneously. Apparent dexmedetomidine-induced stuporous state has not been reported in the human literature.

Enantioselective degradation of alpha-cypermethrin and detection of its metabolites in bullfrog (rana catesbeiana)

Bullfrog, as a kind of amphibians, can be easily exposed to varied pollutants in the environment for the reason of its habitats and highly permeable skin. We investigated the degradation kinetics and residues of α-cypermethrin in bullfrog by two different methods of administration for the environmental monitoring the behavior of one of the most used pesticides in the amphibians. The oral administration and water exposure of α-cypermethrin on bullfrog was studied in this work. α-Cypermethrin and its main metabolites of cis-3-(2',2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (cis-DCCA) and 3-phenoxybenzoic acid (3-PBA), which have been determined that having correlation with a number of epidemic diseases, were detected simultaneously. The method for residue analysis in the bullfrog's organs was validated. The average recoveries for α-cypermethrin were ranged from 71.7% to 100.3% and the limit of quantification was 0.005mg/kg. The average recoveries of its metabolites at levels between 0.002 and 0.5mg/kg ranged between 77.9% and 102.4% with a limit of quantification of 0.002mg/kg. Furthermore, the enantiomers of α-cypermethrin were separated on gas chromatograph (GC) equipped with a chiral column of BGB-172 and the metabolites were detected by gas chromatography (GC) after derivatization. After exposure of α-cypermethrin on bullfrog, the enantioselective degradation behavior was observed and its metabolites were detected in bullfrog tissues. The dynamic trends of α-cypermethrin and its metabolites were fitted to a two-compartment model except 3-PBA fitting to one-compartment model in skin. Concentration of α-cypermethrin and its metabolites in bullfrog's organs increased and reached an equilibrium state during water exposure of α-cypermethrin. Liver and kidney were the major organs for α-cypermethrin and its metabolites retention in both experiments.

Alterations in the inflammatory cytokines and brain-derived neurotrophic factor contribute to depression-like phenotype after spared nerve injury: improvement by ketamine

Although pain is frequently accompanied with depression, little is known about the risk factors contributing to individual differences to the comorbidity of pain and depression. In this study, we examined whether cytokines and brain-derived neurotrophic factor (BDNF) might contribute to the individual differences in the development of neuropathic pain-induced depression. Rats were randomly subjected to spared nerved ligation (SNI) or sham surgery. The SNI rats were divided into two groups by the data from depression-related behavioral tests. Rats with depression-like phenotype displayed higher levels of pro-inflammatory cytokines (e.g., interleukin (IL)-1β, IL-6) as well as imbalance of pro/anti-inflammatory cytokines compared with rats without depression-like phenotype and sham-operated rats. Levels of BDNF in the prefrontal cortex of rats with depression-like phenotype were lower than those of rats without depression-like phenotype and sham-operated rats. A single dose of ketamine ameliorated depression-like behaviors in the rats with depression-like phenotype. Interestingly, higher serum levels of IL-1β and IL-6 in the rat with depression-like phenotype were normalized after a single dose of ketamine. These findings suggest that alterations in the inflammatory cytokines and BDNF might contribute to neuropathic pain-induced depression, and that serum cytokines may be predictable biomarkers for ketamine’s antidepressant actions.

Characterization of fullerenol-protein interactions and an extended investigation on cytotoxicity

Fullerenols, known as polyhydroxylated derivatives of fullerene, have attracted great attention due to their distinctive material properties and potential applications in biology and medicine. As a step toward the elucidation of basic behavior in biological systems, a variety of spectroscopic measurements as well as isothermal titration calorimetry (ITC) were applied to study the interaction between fullerenol (C₆₀(OH)₄₄) and serum proteins (bovine serum albumin (BSA) and γ-globulins). The results of fluorescence spectra indicated that the intrinsic fluorescence of proteins could be effectively quenched by the dynamic mechanism. The affinity values of both proteins bound to fullerenol were of the same order of magnitude. Meanwhile, ITC results showed that the interaction between fullerenol and BSA was enthalpy favorable, while the interaction with γ-globulins was enthalpy unfavorable. Furthermore, fullerenol had little influence on the secondary structure of both proteins. Additional cytotoxicity tests showed that the presence of proteins attenuated the toxic effect of fullerenol on human normal gastric epithelial cell line (GES-1). Thus, the interaction between fullerenol and proteins is indispensable to evaluate the biosafety of fullerenol, which may in turn promotes the development of its biological applications.

Spared Nerve Injury Increases the Expression of Microglia M1 Markers in the Prefrontal Cortex of Rats and Provokes Depression-Like Behaviors

Pain and depression are frequently co-existent in clinical practice, yet the underlying mechanisms remain largely to be determined. Microglia activation and subsequent pro-inflammatory responses play a crucial role in the development of neuropathic pain and depression. The process of microglia polarization to the pro-inflammatory M1 or anti-inflammatory M2 phenotypes often occurs during neuroinflammation. However, it remains unclear whether M1/M2 microglia polarization is involved in the neuropathic pain induced by spared nerve injury (SNI). In the present study, the mechanical withdrawal threshold, forced swim test, sucrose preference test, and open field test were performed. The levels of microglia markers including ionized calcium-binding adaptor molecule 1 (Iba1), cluster of differentiation 11b (CD11b), M1 markers including CD68, inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β), IL-6, tumor necrosis factor-a (TNF-α), 8-hydroxy-2-deoxyguanosine (8-OH-dG), and M2 markers including CD206, arginase 1 (Arg1), IL-4 in the prefrontal cortex were determined on day 14 after SNI. The results showed that SNI produced mechanical allodynia and depressive-like behaviors, and also increased the expressions of microglia markers (Iba1, CD11b) and M1 markers (CD68, iNOS, IL-1β, TNF-α, and 8-OH-dG) in the prefrontal cortex. Notably, minocycline administration reversed these abnormalities. In addition, minocycline also promoted M2 microglia polarization as evidenced by up-regulation of CD206 and Arg1. In conclusion, data from our study suggest that SNI can lead to depression-like behaviors, while M1 polarization and consequent overproduction of pro-inflammatory cytokines plays a key role in the pathogenesis of neuropathic pain. The data furthermore indicate that modulation of inflammation by inhibition of M1 polarization could be a strategy for treatment of neuropathic pain, and might prevent the induction of neuropathic pain-induced depression symptoms.

Mn-Doped ZnSe quantum dots initiated mild and rapid cation exchange for tailoring the composition and optical properties of colloid nanocrystals: novel template, new applications

Although cation exchange (CE) has been studied for many years and some mechanisms were proposed, there is still a knowledge gap in CE and problems such as the need for high temperature and it being time-consuming are still unaddressed. We developed a new mild strategy for CE by introducing a new ideal template and first applied this doping strategy to detect Cd²⁺ and Hg²⁺. This strategy adopted Mn-doped ZnSe quantum dots (QDs) as the template and the introduction occurs via a two-step CE reaction: first Zn²⁺ was partially substituted by X (X = Cd²⁺, Hg²⁺, Cu²⁺, Ag⁺ or Pb²⁺), later Mn²⁺ (in the deep structure of QDs) was substituted by X. Remarkably, Mn²⁺ in the lattice can be easily substituted by a dopant and its replacement by a dopant helps to bury the metal ions. The ultra-fast introduction of Cd²⁺ and Hg²⁺ (70 minutes for Cd²⁺ and 19 minutes for Hg²⁺) was realized at room temperature; other metal ions such as Ag⁺, Cu²⁺ and Pb²⁺ can be buried at 50 °C. This mild reaction temperature offers a solution for introducing impurities without sacrificing the interfacial structure of nanocrystals. HRTEM, XPS and ICP measurements were applied to analyze the introduction process. Furthermore, the spectroscopic method was employed to analyze the introduction, migration and distribution of metal ions. Then, we proposed a mechanism for the chemical conversion of nanocrystals by CE. Through this strategy, full-color light-emitting doped QDs were fabricated. Strikingly, a new turn-on probe for the detection of Cd²⁺ and Hg²⁺ with improved selectivity was developed by adopting this doping strategy. The detection limit is 36 nM for Cd²⁺ and 20 nM for Hg²⁺, which is competitive with the limit of detection reported by other groups using QDs as sensors.

Environmental behavior of the chiral insecticide fipronil: Enantioselective toxicity, distribution and transformation in aquatic ecosystem

The enantioselective environmental behaviors of the chiral insecticide fipronil and its metabolites in lab-scale aquatic ecosystems were studied and the toxicity of fipronil enantiomers and the metabolites to non-target organisms Lemna minor (L. minor) and Anodonta woodiana (A. woodiana) was also investigated in this work. Water-sediment, water-L. minor, water-A. woodiana, and water-sediment-L. minor-A. woodiana ecosystems were set up and exposed to fipronil through a 90-day period. The results showed fipronil could be degraded significantly faster (half-life of 4.6 days) in the complex water-sediment-L. minor-A. woodiana ecosystem. A. woodiana played a crucial role in the dissipation of fipronil, and the microorganisms in the sediment also made great contribution to the degradation of fipronil in aquatic ecosystems. All the three metabolites fipronil desulfinyl, fipronil sulfide and fipronil sulfone were detected in the ecosystems and were more persistent than fipronil. Enantioselective degradation of fipronil was observed with S-fipronil being preferentially degraded in sediment and L. minor, while R-fipronil was metabolized preferentially in A. woodiana. EC₅₀ for L. minor was obtained using 7-day exposure, and for A. woodiana was obtained using 72-h exposure. S-fipronil was more toxic to A. woodiana, while R-fipronil showed higher toxicity to L. minor. Moreover, the three metabolites were found more toxic than fipronil indicating significant environment risks due to their persistence. The present study might have important implications for the risk assessment of fipronil and its metabolites in real aquatic environment.

The toxicity, bioaccumulation, elimination, conversion of the enantiomers of fipronil in Anodonta woodiana

The enantioselective bioaccumulation and elimination of fipronil in Anodonta woodiana (A. woodiana) were studied and the main metabolites fipronil desulfinyl, fipronil sulfide and fipronil sulfone were determined. The acute toxicity of the enantiomers of fipronil and the three metabolites were also investigated. In the bioaccumulation process, fipronil in A. woodiana reached equilibrium after 11days with BCF value of 0.2, and the enantiomeric fraction (EF) values showed that the bioaccumulation was enantioselective with enantioenrichment of S-fipronil. The degradation of fipronil in A. woodiana fitted first-order kinetics model with half-lives of the enantiomers were 5.8 d for R-fipronil and 7.6 d for S-fipronil, and the EF values decreasing from 0.5 gradually indicating the R-enantiomer was preferentially degraded. The degradation of single enantiomers was also performed and the results revealed a fast conversion of R-fipronil to S-fipronil by A. woodiana. The three metabolites were all detected in A. woodiana-water system, in which fipronil sulfone and fipronil sulfide had higher concentration levels. According to the 72-h LC50 values, S-fipronil was much more toxic than the racemate and R-fipronil. Moreover, the metabolites were more toxic than the parent fipronil. The results suggested the individual enantiomers of chiral pollutants and the metabolites should be considered in the risk assessments.

Mesenchymal Stem Cell Modulates T Follicular Helper Cell to Induce Immunotolerance of Islet Allograft

OBJECTIVE

To verify whether mesenchymal stem cells protected the islet allograft via modulating follicular B helper T cells (Tfh) cells.

METHODS

The recipient mice were divided into 5 groups. Group A: the diabetic group (n = 12); Group B: islets alone group (n = 12); Group C: MSCs and islets co-transplanted group (n = 12, MSCs = 0.5 × 10(6)); Group D: MSCs and islets co-transplanted group (n = 12, MSCs = 1 × 10(6)); Group E: MSCs and islets co-transplanted group (n = 12, MSCs = 2 × 10(6)); One control group of normal NOD mice was set as well. ELISA was used to examine the autoantibody level of GAD65 Ab, insulin autoantibodies, and insulin. The Tfh count was determined by fluorescence-activated cell sorting. The insulin expression of islet grafts, the infiltration of lymphocytes, and the Tfh cells were observed via hematoxylin and eosin staining and immunohistochemical staining.

RESULTS

There was significant prolonged graft survival and more insulin expression of islet grafts observed in the co-transplant group. A lower level of the Tfh cells and autoantibody GAD65 Ab, insulin autoantibodies were also presented in the co-transplant group (P < .01). The infiltration of lymphocytes in the co-transplant group was notably less than in the islet-alone group (P < .01).

CONCLUSIONS

Mesenchymal stem cells were able to protect the islet allograft by regulating the follicular helper T cells.

Regulation of glutamate transporter 1 via BDNF-TrkB signaling plays a role in the anti-apoptotic and antidepressant effects of ketamine in chronic unpredictable stress model of depression

RATIONALE

Growing evidence suggests that downregulated clearance of glutamate and signaling pathways involving brain-derived neurotrophic factor (BDNF) and its receptor TrkB play a role in morphological changes in the hippocampus of depressed patients. The N-methyl-D-aspartate (NMDA) receptor antagonist ketamine is the most attractive antidepressant, although precise mechanisms are unknown.

OBJECTIVE

In this study, we examined whether hippocampal BDNF-TrkB signaling underlies the antidepressant effects of ketamine via upregulating glutamate transporter 1 (GLT-1) in rats, subjected to the chronic unpredictable stress (CUS) for 42 days. The rats received a single injection of ketamine (10 mg/kg, i.p.) and/or a TrkB inhibitor, K252a (1 μl, 2 mM, intracerebroventicular (i.c.v.)) on day 43. Behavioral tests and brain sample collection were evaluated 24 h later.

RESULTS

The CUS-exposed rats exhibited depression- and anxiety-like behaviors; decreased number of glial fibrillary acidic protein (GFAP)-positive (but not NeuN-positive) cells in the dentate gyrus (DG), CA1, and CA3 areas; increased number of cleaved caspase-3-positive astrocytes; reduced spine density; lower ratio of Bcl2 to Bax; and decreased levels of BDNF, phosphorylated cAMP response element binging protein (CREB), GLT-1, and postsynaptic density 95 (PSD95) proteins in the hippocampus. Ketamine alleviated the CUS-induced abnormalities. The effects of ketamine were antagonized by pretreatment with K252a.

CONCLUSIONS

Our findings suggest that regulation of GLT-1 on astrocytes, responsible for 90 % of glutamate reuptake from the synapse, through BDNF-TrkB signaling is involved in mediation of the therapeutic effects of ketamine on behavioral abnormalities and morphological changes in the hippocampus of the CUS-exposed rats.

Carbon dots reduced and stabilized silver nanoclusters: synthesis and formation mechanisms

Red emitting silver nanoclusters (AgNCs) have been synthesized by using carbon nanodots (CDs) as reductants and stabilizer at a high temperature of 80 °C in ethanol.

Rumex acetosa L. induces vasorelaxation in rat aorta via activation of PI3-kinase/Akt- AND Ca(2+)-eNOS-NO signaling in endothelial cells

Rumex acetosa L. (RA) (Polygonaceae) is an important traditional Chinese medicine (TCM) commonly used in clinic for a long history in China and the aerial parts of RA has a wide variety of pharmacological actions such as diuretic, anti-hypertensive, anti-oxidative, and anti-cancer effects. However, the mechanisms involved are to be defined. The purpose of the present study was to evaluate the vasorelaxant effect and define the mechanism of action of the ethanol extract of Rumex acetosa L. (ERA) in rat aorta. ERA was examined for its vascular relaxant effect in isolated phenylephrine-precontracted rat thoracic aorta and its acute effects on arterial blood pressure. In addition, the roles of the nitric oxide synthase (NOS)-nitric oxide (NO) signaling in the ERA-induced effects were tested in human umbilical vein endothelial cells (HUVECs). The phosphorylation levels of Akt and eNOS were assessed by Western blot analysis in the cultured HUVECs. ERA induced endothelium-dependent vasorelaxation. The ERA-induced vasorelaxation was abolished by L-NAME (an NOS inhibitor) or ODQ (a sGC inhibitor), but not by indomethacin. Inhibition of PI3-kinase/Akt signaling pathway markedly reduced the ERA-induced vasorelaxation. In HUVECs, ERA increased NO formation in a dose-dependent manner, which was inhibited by L-NAME and by removing extracellular Ca(2+). In addition, ERA promoted phosphorylation of Akt and eNOS, which was prevented by wortmannin and LY294002, indicating that ERA induces eNOS phosphorylation through the PI3-kinase/Akt pathway. Further, in anesthetized rats, intravenously administered ERA decreased arterial blood pressure in a dose-dependent manner through an activation of the NOS-NO system. In summary, the ERA- induced vasorelaxation was dependent on endothelial integrity and NO production, and was mediated by activation of both the endothelial PI3-kinase/Akt- and Ca(2+)-eNOS-NO signaling and muscular NO-sGC-cGMP signaling.

Enantioselective toxicity and degradation of the chiral insecticide fipronil in Scenedesmus obliguus suspension system

Fipronil is an effective insecticide, but it presents highly toxic effects in nontarget aquatic organisms. The present study examined the enantioselective toxicity and degradation of fipronil enantiomers in a freshwater algae Scenedesmus obliguus suspension. There was a substantial difference in the acute toxicity of the enantiomers to S. obliguus, with 72-h median effective concentrations (EC50s) of 0.29 mg L(-1) and 1.50 mg L(-1) for the R-fipronil and S-fipronil, respectively. The influences on the concentration of chlorophyll a, chlorophyll b, and carotenoids were determined, and the effects of fipronil on the concentration of chlorophyll a and chlorophyll b were also enantioselective. The degradation of fipronil in algae suspension was enantioselective, with half-lives for R-fipronil and S-fipronil of 2.9 d and 3.2 d, respectively, and the enantiomer fraction reaching 0.65 at the day 17. The enantiomeric differences should be taken into consideration for fipronil risk assessment.

The potential signaling pathway between peroxisome proliferator-activated receptor gamma and retinoic acid receptor alpha in renal interstitial fibrosis disease

Peroxisome proliferator-activated receptorγ (PPARγ) can regulate the process of cell apoptosis and is related to the progression of renal disorders. Retinoic acid receptor alpha (RARα) is one of the nuclear receptors involved in a variety of kidney diseases. Renal interstitial fibrosis (RIF) is a common denominator of chronic kidney disease (CKD). This study investigated whether a potential signaling pathway existed between PPARγ and RARα in RIF rats with unilateral ureteral obstruction (UUO). The rats were randomly divided into four groups: a model group subjected to UUO (GU), and three other groups treated with rosiglitazone sodium (GRS), GW9662 and dimethyl sulfoxide (DMSO), n = 40, respectively. Renal tissues were collected two and four weeks after post-surgery. The relevant indicators were detected. In comparison with the GU group, the expressions of PPARγ and RARα (protein and mRNA) were increased in the GRS group, and decreased in the GW9662 group (all p < 0.01). The RIF index, mRNA and protein expression of transforming growth factor-β1 (TGF-β1), and the protein expressions of collagen-IV (Col-IV) and fibronectin (FN) in the GRS group were more markedly reduced than those in the GU group; their levels in the GW9662 group were elevated (all p < 0.01). PPARγ or RARα was negatively correlated to the RIF index, TGF-β1, Col-IV and FN. PPARγ was positively correlated with RARα (all p < 0.01). In conclusion, PPARγ agonist can elevate the expression of PPARγ or RARα in RIF rats. There might be a potential signaling pathway between PPARγ and RARα in RIF disease.

Enantioselective toxicity, bioaccumulation and degradation of the chiral insecticide fipronil in earthworms (Eisenia feotida)

The enantioselective acute toxicity to earthworms of racemic fipronil and its individual enantiomers was studied. R-(-)-fipronil was approximately 1.5 times more toxic than the racemate and approximately 2 times more toxic than S-(+)-fipronil after 72 and 96 h of exposure, respectively. Assays of fipronil enantiomer bioaccumulation and degradation in earthworms were conducted. The bio-concentration factors (BCFs) were slightly different between the two enantiomers. The enantiomeric fraction (EF) values in earthworms in the bioaccumulation period were approximately 0.5, which indicated there was no enantioselective bioaccumulation. In contrast, the degradation of fipronil in earthworms was enantioselective: the t1/2 values for R- and S-fipronil were 3.3 and 2.5 days, respectively, in natural soil, and 2.1 and 1.4 days, respectively, in artificial soil. The results of soil analyses showed that the degradation of fipronil was not enantioselective, which suggested that the enantioselectivity of fipronil in earthworms results from the organism's metabolism. The study also demonstrated that the presence of earthworms could accelerate the degradation of fipronil in soil.

Effect of equivalent doses of fentanyl, sufentanil, and remifentanil on the incidence and severity of cough in patients undergoing abdominal surgery: A prospective, randomized, double-blind study

BACKGROUND

Fentanyl congeners have been found to induce cough during induction of general anesthesia. Studies of fentanyl and sufentanil have found incidence rates of 28% to 65% and 15%, respectively. However, no study has assessed the occurrence of cough induced by remifentanil.

OBJECTIVE

The aim of this study was to assess the effect of equivalent doses of fentanyl, sufentanil, and remifentanil on cough.

METHODS

Patients rated American Society of Anesthesiologists class I or II of either sex, aged 18 to 60 years, who were scheduled for elective abdominal surgery with general anesthesia were randomly and equally assigned to 3 groups using a computer-generated table of random numbers. The patients received equivalent doses of fentanyl 2 μg/kg, sufentanil 0.2 μg/kg, or remifentanil 2 μg/kg via IV push. Vital signs (systolic blood pressure [SBP], heart rate [HR], and oxygen saturation via pulse oximetry [SpO2]) and the occurrence and severity of cough were recorded for 2 minutes after drug administration by an anesthesiologist who was blinded to the drug treatment. The severity of cough was graded as none (0), mild (1-2), moderate (3-5), or severe (>5).

RESULTS

A total of 315 Chinese patients (197 women, 118 men; mean [SD] age, 37.9 [10.4] years) were approached for enrollment and assigned to 3 groups of 105 patients each; all patients completed the study protocol. The 3 treatment groups were similar in terms of demographic characteristics and type of abdominal surgery. The incidence of cough was significantly greater in the remifentanil group (57 [54.3%] patients) than in the fentanyl group (35 [33.3%]; P < 0.01) or the sufentanil group (32 [30.5%]; P < 0.01). The severity of cough was significantly greater in the remifentanil group (severe, moderate, mild, none: 24, 7, 26, 48) than in the fentanyl (7, 9, 19, 70; P < 0.01) or sufentanil group (4, 2, 26, 73; P < 0.01). In all 3 groups, when the patients coughed, significant increases were observed in their SBP (128 [12]-139 [16] mm Hg; P < 0.01) and HR (74 [10]-87 [16] beats/min; P < 0.01). Within 2 minutes after drug administration, 62 patients (59%) in the remifentanil group experienced hypoxemia (SpO2 <90%) necessitating manually assisted mask ventilation, while no patients experienced hypoxemia in the fentanyl or sufentanil group. Three patients (2.9%) in the remifentanil group experienced muscle rigidity and deterioration of SBP, HR, and SpO2. No other adverse events were recorded. Cunclusion: Remifentanil was associated with a significantly greater incidence and severity of cough than equivalent doses of fentanyl or sufentanil. Fentanyl and sufentanil appeared comparable in these Chinese patients undergoing abdominal surgery.

Mitochondrial dysfunction induced by different concentrations of gadolinium ion

Gadolinium-based compounds are the most widely used paramagnetic contrast agents in magnetic resonance imaging on the world. But the tricationic gadolinium ion (Gd(3+)) could induce cell apoptosis probably because of its effects on mitochondria. Until now, the mechanism about how Gd(3+) interacts with mitochondria is not well elucidated. In this work, mitochondrial swelling, collapsed transmembrane potential and decreased membrane fluidity were observed to be important factors for mitochondrial permeability transition pore (mtPTP) opening induced by Gd(3+). The protection effect of CsA (Cyclosporin A) could confirm high concentration of Gd(3+) (500 μM) would trigger mtPTP opening. Moreover, mitochondrial outer membrane breakdown and volume expansion observed clearly by transmission electron microscopy and the release of Cyt c (Cytochrome c) could explain the mtPTP opening from another aspect. In addition, MBM(+) (monobromobimane(+)) and DTT (dithiothreitol) could protect thiol (-SH) groups from oxidation so that the toxicity of Gd(3+) might be resulted from the chelation of -SH of membrane proteins by free Gd(3+). Gd(3+) could inhibit the initiation of mitochondrial membrane lipid peroxidation, so it might interact with anionic lipids too. These findings will highly contribute to the safe applications of Gd-based agents.

High concentration of gadolinium ion modifying isolated rice mitochondrial biogenesis

Mitochondria play an important role in plant growth and development, cooperating with the endoplasmic reticulum and nucleus. Gadolinium, one of the rare earth elements, is an inhibitor of stretch-activated calcium channels located on the endoplasmic reticulum and plasma membrane and has no effect on nuclear calcium variation in plant cells. We analyzed the effects of Gd3+ on mitochondria function by monitoring mitochondrial swelling, changes of membrane fluidity, and transmembrane potential collapse and by observing mitochondrial ultrastructure. We found that high concentration of Gd3+ induces rice mitochondrial dysfunction through mitochondrial permeability transition (MPT). The protection of DTT and EDTA demonstrate that Gd3+ blocks the inner membrane ion channel through thiol chelation.

Process of aerenchyma formation and reactive oxygen species induced by waterlogging in wheat seminal roots

The development and regulation of aerenchyma in waterlogged conditions were studied in the seminal roots of wheat. Evans blue staining and the first cell death position indicated that the cortical cell death began at the root mid-cortex cells in flooding conditions. Continuous waterlogging treatment caused the spread of cell death from the mid-cortex to the neighboring cells and well-developed aerenchyma was formed after 72 h. Meanwhile, the formation of radial oxygen loss barrier was observed in the exodermis owing to the induction of Casparian bands and lignin deposition. Analysis of aerenchyma along the wheat root revealed that aerenchyma formed at 10 mm from the root tip, significantly increased toward the center of the roots, and decreased toward the basal region of the root. In situ detection of radial oxygen species (ROS) showed that ROS accumulation started in the mid-cortex cells, where cell death began indicating that cell death was probably accompanied by ROS production. Further waterlogging treatments resulted in the accumulation of ROS in the cortical cells, which were the zone for aerenchyma development. Accumulation and distribution of H₂O₂ at the subcellular level were revealed by ultracytochemical localization, which further verified the involvement of ROS in the cortical cell death process (i.e., aerenchyma formation). Furthermore, gene expression analysis indicated that ROS production might be the result of up-regulation of genes encoding for ROS-producing enzymes and the down-regulation of genes encoding for ROS-detoxifying enzymes. These results suggest that aerenchyma development in wheat roots starts in the mid-cortex cells and its formation is regulated by ROS.

Cell wall degradation and the dynamic changes of Ca2+ and related enzymes in the developing aerenchyma of wheat (Triticum aestivum L.) under waterlogging

This research was aimed to study the cell wall degradation and the dynamic changes of Ca2+ and related enzymes in developing aerenchyma of wheat root under waterlogging. An examination of morphological development by light and electron microscope revealed that the structure of cell wall in middle cortical cells remained intact after 12 h of waterlogging and turned thinner after waterlogging for 24 h. At 48 h, the aerenchyma has been formed. The cellulase activity gradually increased in middle cortical cells within 24 h of waterlogging, and decreased with the formation of aerenchyma. Fluorescence detection and subcellular localization of Ca2+ showed the dynamic changing of Ca2+ at the cellular and subcellular levels during the development of aerenchyma. The activity of Ca2+-ATPase enhanced markedly in intercellular space, plasma membrane and tonoplast of some middle cortical cells after 8 h of waterlogging and remained high after 24 h, but it decreased after 48 h of waterlogging. All these suggests that cellulase, Ca2+ and Ca2+-ATPase show a dynamic distribution during the aerenchyma development which associated with the cell wall degradation of middle cortical cells. Moreover, there is a feedback regulation between Ca2+ and Ca2+-ATPase.