Antioxidative Effects and Mechanism Study of Bioactive Peptides from Defatted Walnut ( Juglans regia L.) Meal Hydrolysate

The peptide components of defatted walnut ( Juglans regia L.) meal hydrolysate (DWMH) remain unclear, hindering the investigation of biological mechanisms and exploitation of bioactive peptides. The present study aims to identify the peptide composition of DWMH, followed by to evaluate in vitro antioxidant effects of selected peptides and investigate mechanisms of antioxidative effect. First, more than 1 000 peptides were identified by de novo sequencing in DWMH. Subsequently, a scoring method was established to select promising bioactive peptides by structure based screening. Eight brand new peptides were selected due to their highest scores in two different batches of DWMH. All of them showed potent in vitro antioxidant effects on H₂O₂-injured nerve cells. Four of them even possessed significantly stronger effects than DWMH, making the selected bioactive peptides useful for further research as new bioactive entities. Two mechanisms of hydroxyl radical scavenging and ROS reduction were involved in their antioxidative effects at different degrees. The results showed peptides possessing similar capacity of hydroxyl radical scavenging or ROS reduction may have significantly different in vitro antioxidative effects. Therefore, comprehensive consideration of different antioxidative mechanisms were suggested in selecting antioxidative peptides from DWMH.

Research Status of New Designer Drug Methcathinone in Forensic Toxicology

Methcathinone, a new cathinone designer drug, which is structurally similar to amphetamine analogs, is a central nervous stimulant. Recently, there has been a worldwide rise in its popularity and abuse, and a growing number of cases with disability or even death is reported in several countries, resulting in public concern. The typical symptoms include accelerated heartbeat, high temperature, anxiety, depression, etc. Forensic studies on its toxicity mechanism are rare. This article reviews its toxicological effects, poisoning symptoms, poisoning and addiction mechanisms, and detection methods, to provide theoretical reference for future studies and guidance for related forensic identification.

Highly efficient InGaN green mini-size flip-chip light-emitting diodes with AlGaN insertion layer

We demonstrate highly efficient InGaN-based mini-size green light-emitting diodes (mLEDs) with AlGaN insertion layer in InGaN/GaN multiple quantum wells (MQWs) using metal organic chemical vapor deposition (MOCVD). High resolution transmission electron microscopy (HRTEM) results reveal that 'V' defects within active region can be effectively reduced by AlGaN insertion layer. Photoluminescence (PL) and time resolved photoluminescence (TRPL) results indicate an increase of radiative recombination efficiency. Very high performance 523 nm InGaN green flip-chip mLEDs (0.025 mm²) with distributed Bragg reflector (DBR) show a high external quantum efficiency (EQE) of 38.0%, a high wall-plug efficiency (WPE) of 32.1% and a low forward voltage of 2.8 V at a working current density of 20 A cm^-2, which are very promising for display application.

Notch signaling in bone marrow-derived FSP-1 cells initiates neointima formation in arteriovenous fistulas

Neointima formation is a major contributor to arteriovenous fistula (AVF) failure. We have previously shown that activation of the Notch signaling pathway contributes to neointima formation by promoting the migration of vascular smooth muscle cells (VSMCs) into the venous anastomosis. In the current study we investigated the mechanisms underlying the dedifferentiation and migration of VSMCs, and in particular the role of bone marrow-derived fibroblast specific protein 1 (FSP-1)⁺ cells, another cell type found in models of vascular injury. Using VSMC-specific reporter mice, we found that most of the VSMCs participating in AVF neointima formation originated from dedifferentiated VSMCs. We also observed infiltration of bone marrow-derived FSP-1+ cells into the arterial anastomosis where they could interact with VSMCs. In vitro, conditioned media from FSP-1+ cells stimulated VSMC proliferation and phenotype switching. Activated Notch signaling transformed FSP-1⁺ cells into type I macrophages and stimulated secretion of cytokines and growth factors. Pretreatment with a Notch inhibitor or knockout of the canonical downstream factor RBP-Jκ in bone marrow-derived FSP1⁺ cells decreased FSP1⁺ cell infiltration into murine AVFs, attenuating VSMC dedifferentiation and neointima formation. Our results suggest that targeting Notch signaling could provide a new therapeutic strategy to improve AVF patency.

Ultrafine ternary metal oxide particles with carbon nanotubes: a metal–organic-framework-based approach and superior lithium-storage performance

A metal–organic-framework template approach was used to fabricate ultrafine ternary metal oxide nanoparticles embedded in CNTs, which exhibit larger-than-theoretical reversible capacities for lithium-ion batteries.

[Clinical efficacy observation on combination of narrow-spectrum medium-wave ultraviolet, red light, and low power He-Ne laser in treating post-burn eczema]

Objective: To investigate the clinical effects of combined utilization of narrow-spectrum medium-wave ultraviolet, red light, and low power He-Ne laser on treatment of post-burn eczema. Methods: From July 2014 to July 2017, 80 patients with post-burn eczema who met the study inclusion criteria were treated in our burn rehabilitation center, and their clinical data were analyzed retrospectively. Patients were divided into ultraviolet treatment group, red light treatment group, laser treatment group, and combination treatment group according to the utilized treatment methods, with 20 cases in each group. Patients in ultraviolet treatment group were treated with narrow-spectrum medium-wave ultraviolet once every other day for 10 minutes each time. Patients in red light treatment group and laser treatment group were treated with red-light and low power He-Ne laser respectively once a day for 10 minutes each time. Patients in combination treatment group were treated with combination of the above three methods without sequence or interval time, and the treatment time and interval time were the same as the previously described. All patients were treated for four weeks since the time of admission. The itching degree, surface area of the affected body, degree of keratosis, and degree of cracking of target tissue were evaluated using Eczema Area and Severity Index (EASI) scoring method after each treatment. Eczema improvement rate was calculated according to the total score of EASI to determine the curative effect. The therapeutic effective time was recorded. The therapeutic effective rate was calculated according to the total scores of EASI before treatment for the first time and 4 weeks after treatment. Besides, the adverse reactions of patients were also observed and recorded. Data were analyzed by Chi-square test, Kruskal-Wallis rank sum test, Wilcoxon signed rank sum test, one-way analysis of variance, Least Significant Difference-t test, and Bonferroni correction. Results: Therapeutic effective times of eczema of patients in ultraviolet treatment group, red light treatment group, and laser treatment group were similar, respectively (13.7±1.3), (16.4±1.6), and (15.1±1.7) d (t=0.32, 0.58, 0.74, P>0.05). The therapeutic effective time of combination treatment group was (6.3±0.9) d, significantly shorter than that of ultraviolet treatment group, red light treatment group, or laser treatment group (t=5.62, 4.72, 4.61, P<0.05 or P<0.01). Compared with those before treatment for the first time, eczema itching degree, surface area of affected body, degree of keratosis, degree of cracking, and total score of EASI of patients in ultraviolet treatment group, red light treatment group, laser treatment group, and combination treatment group showed obvious improvement in 4 weeks after treatment (Z=5.372, 4.392, 4.284, 3.998, 4.092, 3.904, 4.042, 4.216, 3.684, 3.890, 5.081, 4.794, 4.094, 3.493, 3.995, 5.084, 4.903, 4.384, 3.995, 4.063, P<0.05 or P<0.01). Each item score and total score of EASI of eczema of patients in the first three groups were close (P>0.05), while each item score and total score of EASI of eczema of patients in combination treatment group was significantly better than those of ultraviolet treatment group, red light treatment group, and laser treatment group (H=2.482, 2.491, 3.583, 3.462, 6.025, 2.492, 3.693, 3.085, 3.482, 6.042, 5.831, 5.831, 4.893, 4.092, 6.931, P<0.05). Therapeutic effective rates of eczema of patients in ultraviolet treatment group, red light treatment group, and laser treatment group were close, respectively 60%, 60%, and 55% (χ(2)=1.46, 1.63, 0.97, P>0.05). The therapeutic effective rate of eczema of patients in combination treatment group was 90%, significantly higher than that of ultraviolet treatment group, red light treatment group, or laser treatment group (χ(2)=3.43, 4.15, 2.97, P<0.05 or P<0.01). There were no serious adverse reactions appeared in patients of all the four groups after treatment. Three patients in ultraviolet treatment group had local skin erythema, which was alleviated after symptomatic treatment. Conclusions: Combination of narrow-spectrum medium-wave ultraviolet, red light, and low power He-Ne laser in treating post-burn eczema is superior to single therapy in terms of clinical effective time and efficacy, which has no obvious adverse reaction and is worthy of promotion.

Polycyclic aromatic hydrocarbons in soil of the backfilled region in the Wuda coal fire area, Inner Mongolia, China

The Wuda coal fire area in Inner Mongolia, China, has existed for 50 years and been controlled by digging and backfilling for many years. However, few studies have focused on its impact on the local environmental and ecological systems due to emission of organic contaminants from the backfilled region. In the study, topsoil samples were collected at a 0-5 cm depth from the backfilled region of the Wuda coal fire area, which has existed for five years. The samples were analyzed for 16 priority control contaminants, namely polycyclic aromatic hydrocarbons (PAHs), with a standard operation procedure and high-performance liquid chromatograph (HPLC). The results showed that the total mass contentration of 16 PAHs (∑₁₆PAHs) ranged from 279 to 8258 μg kg^-1, with an average value of 2853 ± 2948 µg kg^-1, which exceeded the stipulated limit for heavily contaminated soil (1000 μg kg^-1). Among the 16 PAHs, 2- and 3-ring compounds accounted for more than half of ∑₁₆PAHs. Furthermore, the results show that the main contaminants were the naphthalene (Nap), phenanthrene (Phe), pyrene (Pyr), chrysene (Chr), and benzo[b]fluoranthene (BbF) in this area (24.8%, 51.1%, 3.9%, 4.5%, and 5.7% of ∑₁₆PAHs, respectively). The diagnostic ratio of FLA/(FLA + PYR) exceeded 0.4 and IcdP/(IcdP + BghiP) was less than 0.5, indicating gentle smoldering or spontaneous combustion of coal fire, which differs from traditional coal burning. The environmental health risk or specifically the cancer risk (CR), calculated using the surface soil of the backfilled region, was 2.84 × 10^-6 for adults and 1.01 × 10^-6 for children, thus indicating potential cancer risks. Therefore, PAHs pollution in the surface soil of the backfilled region in the studied coal fire area is an issue that deserves urgent attention.

Very high external quantum efficiency and wall-plug efficiency 527 nm InGaN green LEDs by MOCVD

We demonstrate very high luminous efficacy InGaN-based green light-emitting diodes (LEDs) grown on c-plane patterned sapphire substrates (PSS) using metal organic chemical vapor deposition (MOCVD). The 527 nm green LEDs show a peak external quantum efficiency (EQE) of 53.3%, a peak wall-plug efficiency (WPE) of 54.1% and a peak luminous efficacy of 329 lm/W, respectively. A high EQE of 38.4%, a WPE of 32.1% and a very low forward voltage of 2.86 V were obtained at a typical working current density of 20 A/cm². By operating low cost green LEDs at a low current density, our devices (0.5 mm²) demonstrating an EQE and a WPE higher than 50% and an efficacy of 259 lm/W at 4 A/cm² with an output power of 24 mW. High crystal quality of the InGaN/GaN MQWs was characterized by X-ray diffraction (XRD) and the advantage of the epitaxy design was investigated by APSYS software simulation. These results provide a simple way to achieve very high efficiency InGaN green LEDs.

Spectrum-Effect Relationships between High-Performance Liquid Chromatography (HPLC) Fingerprints and the Antioxidant and Anti-Inflammatory Activities of Collagen Peptides

A total of 13 batches of collagen peptide samples were extracted, isolated, and purified from chicken sternal cartilage under various process parameters. The fingerprint profiles of 13 batches of collagen peptides were established by high-performance liquid chromatography (HPLC). In addition, the amino acid profiles and molecular weight distributions of collagen peptides were investigated. The in vitro antioxidant activities of the peptide samples were measured using the 2,2'-Azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) assay, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, the ferric-reducing antioxidant power (FRAP) assay and an assay of the oxidative damage induced by hydrogen peroxide (H₂O₂) in the degenerative cartilage cells from the knee joint of rat C518 (C518 cell line). The anti-inflammatory activities of the peptide samples were assessed by measuring the inflammatory responses induced by lipopolysaccharides (LPSes) in C518 cells. Subsequently, the spectrum-effect relationships between HPLC fingerprints and the antioxidant and anti-inflammatory activities of collagen peptides were investigated using grey relational analysis (GRA). Fifteen common peaks were obtained from the HPLC fingerprints of collagen peptides. Each collagen peptide sample had a characteristic set of amino acid types and contents. All of the hydrolysates of the collagen peptides were primarily composed of fractions II (500⁻1000 Da) and III (1000⁻3000 Da). Collagen peptides exhibited good scavenging activity on ABTS radical, DPPH radical, and ferric-reducing antioxidant power. Collagen peptides were also effective against H₂O₂-induced cellular oxidative damage in C518 cells. The antioxidant activity of collagen peptides was due to the low molecular weight and the presence of antioxidant and hydrophobic amino acid residues within its sequence. Collagen peptides significantly inhibited the secretion of inflammatory cytokines IL-1β, TNF-α, and PGE2 in C518 cells. The anti-inflammatory activity of collagen peptides may include increased synthesis of the key components of extracellular matrix (ECM) and inhibited apoptosis of chondrocytes. The GRA results showed that peaks 2, 3, and 8 were the main components contributing to the antioxidant activity of the collagen peptides, whereas peaks 11 and 14 were the main components contributing to the anti-inflammatory activity of the collagen peptides. The components of peaks 8 and 14 were identified as GPRGPPGPVGP and VAIQAVLSLYASGR by UPLC-MS/MS. Those identified collagen peptides offer a potential therapeutic strategy for the treatment of osteoarthritis (OA) due to their antioxidative stress and due to them disturbing the catabolism and anabolism processes in arthrodial cartilage.

[Effect of pyrrolidine dithiocarbamate on oxidative stress and mitochondrial function of lung tissue in mice with acute lung injury]

OBJECTIVE

To investigate the effects of pyrrolidine dithiocarbamate (PDTC) on oxidative stress and mitochondrial function of lung tissue in mice with acute lung injury (ALI) induced by lipopolysaccharide (LPS).

METHODS

Forty female Balb/c mice were randomly divided into normal saline (NS) control group, LPS model group, PDTC group, and PDTC+LPS group, with 10 mice in each group. The model of mice with ALI was reproduced by intraperitoneal injection of 15 mg/kg LPS. PDTC was administered intraperitoneally with 50 mg/kg PDTC 1 hour before LPS treatment in the PDTC+LPS group. The mice in NS control group was given intraperitoneal injection of 0.1 mL NS only, and those in PDTC group was given intraperitoneal injection of 50 mg/kg PDTC only. The mice were sacrificed at 24 hours after model reproduction, and the lung tissues were harvested. The total antioxidant capacity (T-AOC) of lung tissue was measured by spectrophotometric kits. The content of malondialdehyde (MDA) was determined by thiobarbituric acid reactive substances assay. The protein expressions of superoxide dismutases (SOD1, SOD2) and catalase (CAT) in lung tissue were determined by Western Blot. Mitochondria from mouse lungs were isolated, and adenosine triphosphate (ATP) synthesis was measured with a luciferase/luciferin-based approach. The mitochondrial membrane potential (ΔΨm) was estimated by using Rhodamine. The mRNA expressions of mitochondrial uncoupling proteins (UCPs) were determined by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

LPS stimulation could significantly increase oxidative stress in lung tissue of mice and lead to mitochondrial dysfunction. The results showed that the protein expressions of T-AOC and SOD1 were decreased, the level of MDA was increased, the ATP synthesis was decreased in the mitochondrial, the ΔΨm was decreased, and the mRNA expression of UCP2 was decreased. However, there was no significant change in the expressions of SOD2, CAT in lung tissue and UCP1, UCP3 in the mitochondria. Pretreatment with PDTC could obviously alleviate the increase in LPS-induced oxidative stress in lung tissue and mitigate mitochondrial dysfunction. Compared with the LPS model group, T-AOC in lung tissue of PDTC+LPS group was significantly increased (U/g: 0.35±0.08 vs. 0.31±0.07), the level of MDA was significantly decreased (μmol/mg: 13.29±1.13 vs. 17.54±1.72), the protein expression of SOD1 was significantly upregulated (SOD1 protein: 1.13±0.11 vs. 0.71±0.09), ATP synthesis was significantly increased in the mitochondrial (μmol/mg: 49.23±5.42 vs. 36.92±2.21), ΔΨm was significantly increased (mV: 226.03±11.69 vs. 194.86±7.79), and the mRNA expression of UCP2 was significantly increased (2^-ΔΔCt: 0.88±0.06 vs. 0.73±0.04). The differences were statistically significant (all P < 0.05). In lung tissue of normal mice, PDTC treatment also had the effect of anti-oxidizing, reducing oxidative stress and promoting ATP synthesis in the mitochondrial. Compared with the NS control group, the level of T-AOC (U/g: 0.49±0.09 vs. 0.43±0.06) and the protein expressions of SOD2 and CAT (SOD2 protein: 1.33±0.08 vs. 1.00±0.11, CAT protein: 1.39±0.08 vs. 1.00±0.11), and ATP synthesis in the mitochondrial of PDTC group was significantly increased (μmol/mg: 61.53±4.92 vs. 53.33±3.20), MDA was significantly decreased (μmol/mg: 10.27±1.25 vs. 12.27±1.36), with statistical differences, but had no effect on the protein expression of SOD1 in lung tissue and ΔΨm and UCPs mRNA expressions in mitochondrion.

CONCLUSIONS

LPS can induce ALI in mice, increased oxidative stress in lung tissue, and induce mitochondrial dysfunction by inhibiting ATP synthesis. PDTC pretreatment has anti-oxidative effect on LPS-induced ALI, and can mitigate mitochondrial dysfunction.

GLI-1 facilitates the EMT induced by TGF-β1 in gastric cancer

OBJECTIVE

To explore how GLI-1 affects the EMT induced by TGF-β1 in gastric cancer.

MATERIALS AND METHODS

Following 24 hours of culture of SGC-7901 cells in presence of TGF-β1, we observed the changes in morphology as well as mRNA and protein expressions of GLI-1, E-cadherin and Vimentin by RT-PCR and Western blot. Transwell assay was conducted to evaluate the changes in invasion ability of SGC-7901 cells. Then, SGC-7901 cells were co-treated with TGF-β1 and GANT 61, and changes of the above indexes were also detected using the corresponding methods.

RESULTS

In presence of TGF-β1, EMT was initiated in SGC-7901 cells EMT with increased cell invasion ability, and the mRNA and protein expressions of E-cadherin were downregulated, while those of the GLI-1 and Vimentin were upregulated. Conversely, the co-treatment of TGF-β1 and GANT 61 suppressed the increased cell invasion ability induced only by TGF-β1, and the changes in mRNA and protein expressions of these factors were abolished.

CONCLUSIONS

We found that GLI-1 facilitates the EMT induced by TGF-β1 in SGC-7901 cells, which may serve as a potential target in developing the clinical treatment of gastric cancer.

The Probiotic Effectiveness in Preventing Experimental Colitis Is Correlated With Host Gut Microbiota

Current evidence to support extensive use of probiotics in inflammatory bowel disease is limited and factors that contribute to the inconsistent effectiveness of clinical probiotic therapy are not completely known. Here, we used Bifidobacterium longum JDM 301 as a model probiotic to study potential factors that may influence the effect of probiotics in experimental colitis. We found that the effect of B. longum JDM 301 in tempering experimental colitis varied across individual mice even with the same genetic background. The probiotic efficacy was highly correlated with the host gut microbial community features. Consumption of a diet rich in fat could exacerbate mucosal injury-induced colitis but could not change the host responsiveness to B. longum JDM 301 treatment, suggesting of potential mechanistic differences between regulating colitis pathogenesis, and modulating probiotic efficacies by the gut microbiota. Together, our results suggest that personalized microbiome features may modify the probiotic therapeutic effect and support the idea of personalized probiotic medicine in inflammatory bowel disease.

The moderate predictive value of serial serum CRP and PCT levels for the prognosis of hospitalized community-acquired pneumonia

BACKGROUND

To predict the prognosis by observing the dynamic change of C-reactive protein (CRP) and procalcitonin (PCT) for hospitalized community-acquired pneumonia (CAP).

METHODS

The data were collected from January to December 2017 from the first affiliated Hospital of Zhengzhou University. Demographic and clinical patient information including age, length of hospital stay and Charlson Comorbidity Index (CCI) were recorded. Blood samples were taken for CRP, PCT, and white blood cell count (WBC). Receiver Operating Characteristic (ROC) curve was used to verify each biomarker's association with the prognosis of pneumonia.

RESULTS

A total of 350 patients were enrolled in the study. The 30-day mortality was 10.86%. Serial serum CRP3, CRP5, PCT3, PCT5 and PCT5c levels were statistically lower in CAP survivors than non-survivors. CRP3c < 0, CRP5c < 0 and PCT5c < 0 were observed with a statistically lower frequency in patients with 30-day mortality and initial treatment failure. The AUC for 30-day mortality for serial CRP levels combined with CRP clearances was 0.85 (95% CI 0.77-0.92), as compared to an AUC of 0.81 (95% CI 0.73-0.9) for serial PCT levels combined with PCT clearances.

CONCLUSIONS

Serum serial CRP and PCT levels had moderate predictive value for hospitalized CAP prognosis. The dynamic CRP and PCT changes may potentially be used in the future to predict hospitalized CAP prognosis.