SP1 transcriptionally activates HTR2B to aggravate traumatic spinal cord injury by shifting microglial M1/M2 polarization.

BACKGROUND: Spinal cord injury (SCI) can result in structural and functional damage to the spinal cord, which may lead to loss of limb movement and sensation, loss of bowel and bladder control, and other complications. Previous studies have revealed the critical influence of trans-acting transcription factor 1 (SP1) in neurological pathologies, however, its role and mechanism in SCI have not been fully studied. METHODS: The study was performed using mouse microglia BV2 stimulated using lipopolysaccharide (LPS) and male adult mice subjected to spinal hitting. Western blotting was performed to detect protein expression of SP1, 5-hydroxytryptamine (serotonin) receptor 2B (HTR2B), BCL2-associated x protein (Bax), B-cell lymphoma-2 (Bcl-2), inducible nitric oxide synthase (iNOS), clusters of differentiation 86 (CD86), Arginase 1 (Arg-1) and clusters of differentiation 206 (CD206). Cell viability and apoptosis were analyzed by MTT assay and TUNEL assay. mRNA levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-4 (IL-4) and tumor necrosis factor-ß (TNF-ß) were quantified by quantitative real-time polymerase chain reaction. The association of SP1 and HTR2B was identified by chromatin immunoprecipitation assay and dual-luciferase reporter assay. HE staining assay was performed to analyze the pathological conditions of spinal cord tissues. RESULTS: LPS treatment induced cell apoptosis and inhibited microglia polarization from M1 to M2 phenotype, accompanied by an increase of Bax protein expression and a decrease of Bcl-2 protein expression, however, these effects were relieved after SP1 silencing. Mechanism assays revealed that SP1 transcriptionally activated HTR2B in BV2 cells, and HTR2B knockdown rescued LPS-induced effects on BV2 cell apoptosis and microglial M1/M2 polarization. Moreover, SP1 absence inhibited BV2 cell apoptosis and promoted microglia polarization from M1 to M2 phenotype by decreasing HTR2B expression. SCI mouse model assay further showed that SP1 downregulation could attenuate spinal hitting-induced promoting effects on cell apoptosis of spinal cord tissues and microglial M1 polarization. CONCLUSION: SP1 transcriptionally activated HTR2B to aggravate traumatic SCI by shifting microglial M1/M2 polarization.

Automatic detection of pulmonary embolism in computed tomography pulmonary angiography using Scaled-YOLOv4.

BACKGROUND: Pulmonary embolism (PE) is a common but fatal clinical condition and the gold standard of diagnosis is computed tomography pulmonary angiography (CTPA). Prompt diagnosis and rapid treatment can dramatically reduce mortality in patients. However, the diagnosis of PE is often delayed and missed. METHODS: In this study, we identified a deep learning model Scaled-YOLOv4 that enables end-to-end automated detection of PE to help solve these problems. A total of 307 CTPA data (Tianjin 142 cases, Linyi 133 cases, and FUMPE 32 cases) were included in this study. The Tianjin dataset was divided 10 times in the ratio of training set: validation set: test set = 7:2:1 for model tuning, and both the Linyi and FUMPE datasets were used as independent external test sets to evaluate the generalization of the model. RESULTS: Scaled-YOLOv4 was able to process one patient in average 3.55 s [95% CI: 3.51-3.59 s]. It also achieved an average precision (AP) of 83.04 [95% CI: 79.36-86.72] for PE detection on the Tianjin test set, and 75.86 [95% CI: 75.48-76.24] and 72.74 [95% CI: 72.10-73.38] on Linyi and FUMPE, respectively. CONCLUSIONS: This deep learning algorithm helps detect PE in real time, providing radiologists with aided diagnostic evidence without increasing their workload, and can effectively reduce the probability of delayed patient diagnosis.

Carminic acid mitigates fructose-triggered hepatic steatosis by inhibition of oxidative stress and inflammatory reaction.

Excessive fructose (Fru) consumption has been reported to favor nonalcoholic fatty liver disease (NAFLD). However, the molecular mechanism is still elusive, lacking effective therapeutic strategies. Carminic acid (CA), a glucosylated anthraquinone found in scale insects like Dactylopius coccus, exerts anti-tumor and anti-oxidant activities. Nevertheless, its regulatory role in Fru-induced NAFLD is still obscure. Here, the effects of CA on NAFLD in Fru-challenged mice and the underlying molecular mechanisms were explored. We found that Fru intake significantly led to insulin resistance and dyslipidemia in liver of mice, which were considerably attenuated by CA treatment through repressing endoplasmic reticulum (ER) stress. Additionally, inflammatory response induced by Fru was also attenuated by CA via the blockage of nuclear factor-κB (NF-κB), mitogen-activated protein kinases (MAPKs) and tumor necrosis factor α/TNF-α receptor (TNF-α/TNFRs) signaling pathways. Moreover, Fru-provoked oxidative stress in liver tissues was remarkably attenuated by CA mainly through improving the activation of nuclear factor erythroid 2-related factor 2 (Nrf-2). These anti-dyslipidemias, anti-inflammatory and anti-oxidant activities regulated by CA were confirmed in the isolated primary hepatocytes with Fru stimulation. Importantly, the in vitro experiments demonstrated that Fru-induced lipid accumulation was closely associated with inflammatory response and reactive oxygen species (ROS) production regulated by TNF-α and Nrf-2 signaling pathways, respectively. In conclusion, these results demonstrated that CA could be considered as a potential therapeutic strategy to attenuate metabolic disorder and NAFLD in Fru-challenged mice mainly through suppressing inflammatory response and oxidative stress.

Carminic acid supplementation protects against fructose-induced kidney injury mainly through suppressing inflammation and oxidative stress via improving Nrf-2 signaling.

Excessive fructose (Fru) intake has become an increased risk for chronic kidney disease progression. Despite extensive researches that have been performed to develop effective treatments against Fru-induced renal injury, the outcome has achieved limited success. In this study, we attempted to explore whether carminic acid (CA) could influence the progression of Fru-induced kidney injury, and the underlying molecular mechanism. At first, our in vitro results showed that CA significantly reduced inflammation in mouse tubular epithelial cells and human tubule epithelial cells stimulated by Fru. The anti-inflammatory effects of CA were associated with the blockage of nuclear factor-κB (NF-κB) signaling. In addition, Fru-exposed cells showed higher oxidative stress, which was effectively restrained by CA treatment through improving nuclear factor (erythroid-derived 2)-like 2 (Nrf-2) nuclear translocation. Importantly, we found that Fru-induced inflammation and oxidative stress were accelerated in cells with Nrf-2 knockdown. What's more, in Fru-stimulated cells, CA-alleviated inflammatory response and reactive oxygen species (ROS) production were evidently abolished by Nrf-2 knockdown. The in vivo analysis demonstrated that Fru led to metabolic disorder, excessive albuminuria and histologic changes in renal tissues, which were effectively reversed by CA supplementation. We confirmed that CA significantly reduced inflammation and oxidative stress in the kidneys of mice through regulating NF-κB and Nrf-2 signaling pathways, eventually alleviating the progression of chronic kidney injury. Taken together, these results identified CA as a potential therapeutic strategy for metabolic stress-induced renal injury through restraining inflammation and oxidative stress via the improvement of Nrf-2 signaling.

Research on the Gravity Disturbance Compensation Terminal for High-Precision Position and Orientation System.

The Position and Orientation System (POS) is the core device of high-resolution aerial remote sensing systems, which can obtain the real-time object position and collect target attitude information. The goal of exceeding 0.015°/0.003° of its real-time heading/attitude measurement accuracy is unlikely to be achieved without gravity disturbance compensation. In this paper, a high-precision gravity data architecture for gravity disturbance compensation technology is proposed, and a gravity database with accuracy better than 1 mGal is constructed in the test area. Based on the "Block-Time Variation" Markov Model (B-TV-MM), a gravity disturbance compensation device is developed. The gravity disturbance compensation technology is applied to POS products for the first time, and is applied in the field of aerial remote sensing. Flight test results show that the heading accuracy and attitude accuracy of POS products are improved by at least 6% and 16%, respectively. The device can be used for the gravity disturbance compensation of various inertial technology products.

[Clinical application of percutaneous iliosacral screws combined with pubic ramus screws in Tile B pelvic fracture].

OBJECTIVE: To investigate the application and effect of minimally invasive percutaneous anterior pelvic pubic ramus screw fixation in Tile B fractures. METHODS: A retrospective review was conducted on 56 patients with posterior pelvic ring injury combined with fractures of anterior pubic and ischiadic ramus treated between May 2010 and August 2015, including 31 males and 25 females with an average age of 36.8 years old ranging from 35 to 65 years old. Based on the Tile classification, there were 13 cases of Tile B1 type, 28 cases of Tile B2 type and 15 cases of Tile B3 type. Among them, 26 patients were treated with sacroiliac screws combined with external fixation (external fixator group) and the other 30 patients underwent sacroiliac screw fixation combined with anterior screw fixation (pubic ramus screw group). Postoperative complications, postoperative ambulation time, fracture healing, blood loss, Majeed pelvic function score and visual analogue scale(VAS) were compared between two groups. RESULTS: Fifty-four patients were followed up from 3 to 24 months with a mean of 12 months. There were no significant difference in the peri-operative bleeding and operation time between two groups(P>0.05). The postoperative activity time and fracture healing time of pubic ramus screw group were shorter than those of the external fixator group, the differences were statistically significant(P<0.05). The Majeed score, VAS score of pubic ramus screw group were higher than those of the external fixator group, the differences were statistically significant(P<0.05). The incidence of postoperative complications of pubic ramus screw was lower than that of the external fixator group, the difference was statistically significant (P<0.05). CONCLUSIONS: Percutaneous iliosacral screws fixation combined with the pubic ramus screw is an effective and safty treatment method to the Tile B pelvic fracture. It has advantages of early ambulation, relief of the pain and few complications.

Investigation on potential enzyme toxicity of clenbuterol to trypsin.

Clenbuterol (CLB) is a kind of ß2-adrenergic agonists which was illegally used as feed additives nowadays. The toxic interaction of CLB with trypsin, an important digestive enzyme, was studied in vitro using multi-spectroscopic methods and molecular modeling methods. CLB was proved to bind with trypsin in S1 pocket, forming a complex driven by the dominant force of H-bond. The binding constant was calculated to be 1.79887×10(5) L mol(-1) at 289 K and 0.32584×10(5) L mol(-1) at 310 K, respectively. The skeleton of trypsin became loosened and unfolded with the amino residues microenvironment changed. The secondary and tertiary structure of trypsin also varied. Molecular modeling studies illustrated specific display of the binding information and explained most of the experiment phenomena. The binding site of CLB induced the fluorescence quenching as well as inhibition of enzyme activity of trypsin. The study confirmed that CLB had potential toxicity on both the structure and function of trypsin and the effects enhanced with the increasing concentration of CLB.

Insights into the binding of 2-aminobenzothiazole with human serum albumin (HSA): spectroscopic investigation and molecular modeling studies.

As one of the important thiazole derivatives, 2-aminobenzothiazole (2-ABT) has been widely used as a structural unit in the synthesis of anti-oxidants, anti-inflammatories, herbicides, antibiotics, and thermoplastic polymers. In this study, the interaction of 2-ABT with human serum albumin (HSA) was investigated in vitro under simulated physiological conditions, using multi-spectroscopic techniques and a molecular modeling study. The binding constant and binding sites were determined through fluorescence quenching spectra. The site-competitive replacement experiments revealed that the precise binding site of 2-ABT on HSA was site II (subdomain IIIA). Moreover, molecular docking results illustrated the electrostatic interaction between Glu 450 and 2-ABT, in accordance with the conclusions from the calculated thermodynamic parameters and the effect of ionic strength. The effect of 2-ABT on the conformational changes of HSA were evaluated by ultraviolet-visible (UV-Vis) absorption, three-dimensional (3D) fluorescence, synchronous fluorescence, and circular dichroism (CD) spectroscopy. This work facilitates comprehensive understanding of the binding of 2-ABT with HSA, contributing to evaluate the molecular transportation mechanism and biotoxicity of 2-aminobenzothiazole derivatives in vivo.

Multi-spectroscopic methods combined with molecular modeling dissect the interaction mechanisms of ractopamine and calf thymus DNA.

The toxic interaction of ractopamine (RAC) with calf thymus DNA (ct DNA) was studied in vitro using multi-spectroscopic methods and molecular modeling methods. The hypochromic effect without a noticeable shift in UV-vis absorption indicated that the minor groove binding mode existed in the interaction between RAC and DNA. The fluorescence quenching of RAC was observed with the increasing addition of DNA and was proved to be the static quenching. The binding constant and the binding site sizes were 4.13 × 10(3) and 0.97, respectively. The thermodynamic calculation demonstrated that the hydrogen bond and van der Waals were main acting forces. This result further confirmed the existence of groove binding mode. Afterwards, we found another interaction mode, electrostatic binding mode through the fluorescence polarization, ionic effects and denatured DNA experiments. Circular dichroism spectroscopy (CD) was then employed to monitor the conformation changes of DNA. Molecular modeling studies illustrated the visual display of the binding mode and the detailed information of the H-bond.

The use of outer filter effects for Cu(2+) quantitation: a unique example for monitoring nonfluorescent molecule with fluorescence.

This article concerns a new and precise strategy for the determination of Cu(2+) based on a color reaction and outer filter effects (OFEs). Cu(2+) can react with sodium diethyldithiocarbamate trihydrate (DDTC) to form a DDTC-Cu(2+) complex with a significant absorption at 447 nm. Being positively correlated with Cu(2+), the absorption could be treated as the basis for the determination of Cu(2+). When cuvettes containing the complex were fixed in the light path of a fluorescence spectrophotometer, the excitation/emitted light were absorbed by the OFEs, similar to absorption mechanisms of inner filter effects. Under suitable conditions, OFEs from the complex could quantitatively reduce the fluorescence intensities of quinine sulfate and acridine yellow by absorbing the excitation or emission light. Compared with traditional absorption spectroscopy (with a detection limit at 0.9 µmol/L), indirect OEF techniques showed increased sensitivities by about 1 order of magnitude. The strategy could be extended to many different systems where components absorb the excitation wavelength and/or emission wavelength of fluorescers.

[Adaptive regularized super-resolution reconstruction for magnetic resonance images].

OBJECTIVE: To increase the resolution and signal-to-noise ratio (SNR) of magnetic resonance (MR) images, an adaptively regularized super-resolution reconstruction algorithm was proposed and applied to acquire high resolution MR images from 4 subpixel-shifted low resolution images on the same anatomical slice. The new regularization parameter, which allowed the cost function of the new algorithm to be locally convex within the definition region, was introduced by the piori information to enhance detail restoration of the image with a high frequency. The experiment results proved that the proposed algorithm was superior to other counterparts in achieving the reconstruction of low-resolution MR images.

The charge ratio between O and N on amide bonds: a new approach to the mobile proton model.

The influence of charge distribution on the cleavage of the peptides was investigated by fragmentation efficiency curves and quantum chemical calculations in order to clarify the fragmentation mechanism in this paper. The peptide Arg-Gly-Asp-Cys (RGDC) was oxidized to change the charge distribution, but its main sequence was retained. Under this study, it was illustrated that the fragmentation of the peptide RGDC became easier with each addition of an O atom to the Cys hydrosulfide group and the relative charge ratios between O and N (QO/QN) in the amide bonds had much to do with the cleavage of the peptide RGDC. For each amide bond, the situations coincided with overall conclusion: the increase of the QO/QN values results in a higher fragmentation efficiency and vice versa. The methods which combined fragmentation efficiency curves with the charge distribution of peptides provided a way to refine the mobile proton model for peptide fragmentation and to probe the discrepant fragmentation of peptides in peptide/protein identification.

Influence of charge distribution on the discrepant MS/MS fragmentation of the native and oxidized FMRF: evidence for the mobile proton model.

Using the mobile proton model as a framework, the influence of charge distribution on the discrepant fragmentation of peptides FMRF, FM(O)RF and FM(O(2))RF (with united peptide sequence) was explored by mass spectrometry experiments and quantum chemical calculations. With the added O atoms, more negative charges were prompted to deposit in the main protonation sites of the oxidation products. Consequently, the solvated proton to the oxidized peptides could flow to the amide bonds in an easier manner and made these bonds fragment easily. Oxidation also induced the discrepant fragmentation of these bonds in a predictable manner: the more negative charges deposited in an amide bond, the more daughter ions (a(n), b(n), y(n) ions and their derivatives) were produced. The combined methods proposed here refined the mobile proton model for peptide fragmentation and opened the way to probe the discrepant fragmentation of peptides in peptide/protein identification.

The relative charge ratio between C and N atoms in amide bond acts as a key factor to determine peptide fragment efficiency in different charge states.

The influence of charge state on the peptide dissociation behavior in tandem mass spectrometry (MS/MS) is worthy of discussion. Comparative studies of singly- and doubly-protonated peptide molecules are performed to explore the effect and mechanism of charge state on peptide fragmentation. In view of the charge-directed cleavage of protonated peptides described in the mobile proton model, radiolytic oxidation was applied to change the charge distribution of peptides but retain the sequence. Experimental studies of collision energy-dependent fragmentation efficiencies coupled with quantum chemical calculations indicated that the cleavage of ARRA and its side-chain oxidation products with oxygen atoms added followed a trend that doubly-protonated peptides fragment more easily than singly-protonated forms, while the oxidation product with the guanidine group deleted showed the opposite trend. By analyzing the charge distribution around the amide bonds, we found that the relative charge ratios between C and N atoms (Q(C)/Q(N)) in the amide bonds provided a reasonable explanation for peptide fragmentation efficiencies. An increase of the Q(C)/Q(N) value of the amide bond means that a peptide fragments more easily, and vice versa. The results described in this paper provide an experimental and calculation strategy for predicting peptide fragmentation efficiency.

[Repair of radius bone defect with the nano-hydroxyapatite/collagen/calcium alginate].

OBJECTIVE: To explore the osteogenic potential of the nano-hydroxyapatite/collagen/calcium alginate composite implanted in animals. METHODS: Eighteen 3-month-old New Zealand white rabbits were adopted to prepare 15 mm segmental defect model at the middle part of radius. Rabbit models were randomly divided into experimental group and blank control group. Nano-hydroxyapatite/collagen/calcium alginate was implanted into the defects of experimental group. Four, 8, and 12 weeks after operation, all specimens were examined by X-ray and histological methods. RESULTS: All the 18 rabbit models entered the final analysis. X-ray showed that osteotylus was seen in the whole defect area in the experimental group 12 weeks after operation, during which osteogenesis was more obvious than in weeks 4 and 8 and the bridge grafting of defect area was obviously visible. In the blank control group, osteotylus was only observed at the two ends of the defects, and no osteogenesis was found in the central part of the defect area. Histological examination showed that new osteoid formation was seen in internal porous zone in the experimental group in weeks 4 and 8; in week 12, more woven bone-like tissues were visible and trabecular-like structure was formed. CONCLUSION: The nano-hydroxyapatite/ collagen/calcium alginate has good osteogenic potential.

[Adaptive super resolution algorithm for under-sampled images].

OBJECTIVE: A new algorithm of adaptive super-resolution (SR) reconstruction based on the regularization parameter is proposed to reconstruct a high-resolution (HR) image from the low-resolution (LR) image sequence, which takes into full account the inaccurate estimates of motion error, point spread function (PSF) and the additive Gaussian noise in the LR image sequence. We established a novel nonlinear adaptive regularization function and analyzed experimentally its convexity to obtain the adaptive step size. This novel algorithm can effectively improve the spatial resolution of the image and the rate of convergence, which is verified by the experiment on optical images.

[Use of L-shaped silicone prosthesis and expanded polytetrafluoraethylene to repair the nasal deformities after repair of unilateral cleft lip: report of 17 cases].

PURPOSE: To evaluate the effect of using L-shaped silicone prosthesis and expanded polytetrafluoraethylene (ePTFE) to correct the nasal deformities after repair of unilateral cleft lip in 17 cases. METHODS: After correction of the malposed nasal cartilages, a chip of ePTFE was added to the tip of the L-shaped silicone prosthesis, and sutured with 5-0 nylon thread, to consolidate and mold the nasal dorsum, tip, ala and nasal columella. RESULTS: Simultaneous use of L-shaped silicone prosthesis and expanded polytetrafluoraethylene could elevate the flat nasal dorsum, tip, ala and nasal columella, which improved the nasal contour significantly. 11 patients achieved excellent esthetic results, and 6 had improvement. CONCLUSION: Use of L-shaped silicone prosthesis and ePTFE to repair the nasal deformities after repair of unilateral cleft lip is a simple and effective method.