Rheology, physicochemical properties, and microstructure of fish gelatin emulsion gel modified by γ-polyglutamic acid.

In this work, the effect of the addition of γ-polyglutamic acid (γ-PGA) on the rheology, physicochemical properties, and microstructure of fish gelatin (FG) emulsion gel was investigated. Samples of the emulsion gel were evaluated for rheological behavior and stability prior to gelation. The mechanical properties and water-holding capacity (WHC) of the emulsion were determined after gelation. The microstructure of the emulsion gel was further examined using confocal laser scanning microscopy (CLSM). The results indicated a gradual increase in the apparent viscosity and gelation temperature of the emulsion at a higher concentration of γ-PGA. Additionally, frequency scan results revealed that on the addition of γ-PGA, FG emulsion exhibited a stronger structure. The emulsion containing 0.1% γ-PGA exhibited higher stability than that of the control samples. The WHC and gel strength of the emulsion gel increased on increasing the γ-PGA concentration. CLSM images showed that the addition of γ-PGA modified the structure of the emulsion gel, and the droplets containing 0.1% γ-PGA were evenly distributed. Moreover, γ-PGA could regulate the droplet size of the FG emulsion and its size distribution. These findings suggest that the viscoelasticity and structure of FG emulsion gels could be regulated by adjusting the γ-PGA concentration. The γ-PGA-modified FG emulsion gel also exhibited improved rheology and physicochemical properties. The results showed that γ-PGA-modified FG emulsion gel may find potential applications in food, medicine, cosmetics, and other industries.

A peptide selectively recognizes Gram-negative bacteria and forms a bacterial extracellular trap (BET) through interfacial self-assembly.

An innate immune system intricately leverages unique mechanisms to inhibit colonization of external invasive Bacteria, for example human defensin-6, through responsive encapsulation of bacteria. Infection and accompanying antibiotic resistance stemming from Gram-negative bacteria aggregation represent an emerging public health crisis, which calls for research into novel anti-bacterial therapeutics. Herein, inspired by naturally found host-defense peptides, we design a defensin-like peptide ligand, bacteria extracellular trap (BET) peptide, with modular design composed of targeting, assembly, and hydrophobic motifs with an aggregation-induced emission feature. The ligand specifically recognizes Gram-negative bacteria via targeting cell wall conserved lipopolysaccharides (LPS) and transforms from nanoparticles to nanofibrous networks in situ to trap bacteria and induce aggregation. Importantly, treatment of the BET peptide was found to have an antibacterial effect on the Pseudomonas aeruginosa strain, which is comparable to neomycin. Animal studies further demonstrate its ability to trigger aggregation of bacteria in vivo. This biomimetic self-assembling BET peptide provides a novel approach to fight against pathogenic Gram-negative bacteria.

A self-assembling peptide inhibits the growth and function of fungi via a wrapping strategy.

Fungal infections contribute substantially to human morbidity and mortality. A particular concern is the high rate of mortality associated with invasive fungal infections, which often exceeds 50.0% despite the availability of several antifungal drugs. Herein, we show a self-assembling antifungal peptide (AFP), which is able to bind to chitin on the fungal cell wall and in situ form AFP nanofibers, wrapping fungi. As a result, AFP limits the proliferation of fungi, slows down the morphological transformation of biphasic fungi, and inhibits the adhesion of fungi to host cells and the formation of biofilms. Compared to the broad-spectrum antifungal fluconazole, AFP achieved a comparable inhibitory effect (MIC50 = 3.5 µM) on fungal proliferation. In addition, AFP significantly inhibited the formation of fungal biofilms with the inhibition rate of 69.6% at 1 µM, better than fluconazole (17.2% at 1 µM). In a skin infection model of mice, it was demonstrated that AFP showed significantly superior efficacy to fluconazole. In the systemic candidiasis mouse model, AFP showed similar efficacy to first-line antifungal amphotericin B (AmpB) and anidulafungin (AFG). This study provides a promising wrapping strategy for anti-fungal infection.

Ultrasound-assisted extraction and characterization of Penthorum chinense polysaccharide with anti-inflammatory effects.

Penthorum chinense has been used in both food and medication for many years, and polysaccharide of which was considered as one of the bioactive compounds. However, the extraction process of polysaccharide from P. chinense (PCP) was not well optimized. Ultrasound-assisted extractionhas been widely employed in the extraction of natural products for its compliance with the concept of green and economic chemistry. To better investigate the structure and biology activity of PCP, response surface methodology was employed to optimize the ultrasound-assisted extraction conditions of PCP. The optimum extraction for the ultrasound-assisted extraction of PCP were obtained as ratio of solvent to material 40 mL/g, ultrasonic power 380 W, and extraction time of 50 min. The yield of PCP reached 8.71% under these optimized conditions. PCP was further purified by using anion exchange chromatography and gel filtration, an acidic fraction PCP-AP-1 was hereby obtained. The results of structural elucidation indicated that PCP-AP-1 was a typical pectic polysaccharide with a molecular weight of 66360 Da, mainly composed of galacturonic acid (68.5 mol%), followed by arabinose (9.8 mol%), rhamnose (9.4 mol%), glucose (7.7 mol%), with homogalacturonan region and rhamnogalacturonan I regions. In vitro study showed that PCP-AP-1 could improve the inflammation induced by lipopolysaccharide in intestinal epithelial cells, which was probably performed through the inhibition of multiple signaling pathways including the inhibition of TLR4, NOD1/2 and NF-κB pathway, as well as the reduction of NLRP3 inflammasome. This study defined the type of polysaccharide present in P. chinense and revealed a potential of application this plant in the prevention of intestinal inflammatory diseases.

Ultrasonic treatment regulates the properties of gelatin emulsion to obtain high-quality gelatin film.

Gelatin emulsion was an important process for preparing gelatin films. A gelatin film with water resistance and ductility could be prepared using gelatin emulsion, whereas the prepared gelatin film has several defects (e.g., low tensile strength and poor thermal stability). This study aimed to modify gelatin emulsion through ultrasonic treatment, then gelatin film was prepared by the modified gelatin emulsion. The results showed that: under the condition of ultrasonic treatment for 12 min at 400 w, zeta potential and viscosity of gelatin emulsion were the largest; thickness, water vapor permeability (WVP) and water solubility (WS) of corresponding gelatin film were the lowest, and the tensile strength (TS), elongation at break (EAB), denaturation temperature (Tm) and enthalpy value (ΔH) of corresponding gelatin film were the highest. The above result suggested that ultrasonic treatment can be used to prepare a gelatin film with better quality by regulating the properties of gelatin emulsion, and a certain correlation was found between the properties of gelatin emulsion and the properties of gelatin film.

Fabrication and Assembly Techniques for Sub-mm Battery-Free Epicortical Implants.

Over the past three decades, we have seen significant advances in the field of wireless implantable medical devices (IMDs) that can interact with the nervous system. To further improve the stability, safety, and distribution of these interfaces, a new class of implantable devices is being developed: single-channel, sub-mm scale, and wireless microelectronic devices. In this research, we describe a new and simple technique for fabricating and assembling a sub-mm, wirelessly powered stimulating implant. The implant consists of an ASIC measuring 900 × 450 × 80 µm3, two PEDOT-coated microelectrodes, an SMD inductor, and a SU-8 coating. The microelectrodes and SMD are directly mounted onto the ASIC. The ultra-small device is powered using electromagnetic (EM) waves in the near-field using a two-coil inductive link and demonstrates a maximum achievable power transfer efficiency (PTE) of 0.17% in the air with a coil separation of 0.5 cm. In vivo experiments conducted on an anesthetized rat verified the efficiency of stimulation.

Trophoblastic mitochondrial DNA induces endothelial dysfunction and NLRP3 inflammasome activation: Implications for preeclampsia.

AIMS: Preeclampsia (PE) is characterised by systemic vascular endothelium dysfunction. Circulating trophoblastic secretions contribute to endothelial dysfunction, resulting in PE; however, the underlying mechanisms remain unclear. Herein, we aimed to determine the potential correlation between the release of trophoblastic mitochondrial deoxyribonucleic acid (DNA) (mtDNA) and endothelium damage in PE. MATERIALS AND METHODS: Umbilical cord sera and tissues from patients with PE were investigated for inflammasome activation. Following this, trophoblastic mitochondria were isolated from HTR-8/SVneo trophoblasts under 21 % oxygen (O2) or hypoxic conditions (1 % O2 for 48 h) for subsequent treatments. Primary human umbilical veinendothelial cells (HUVECs) were isolated from the human umbilical cord and then exposed to a vehicle (phosphate-buffered saline [PBS]), mtDNA, hypo-mtDNA, or hypo-mtDNA with INF39 (nucleotide oligomerisation domain-like receptor family pyrin domain containing 3 [NLRP3]-specific inhibitor) for 12 h before flow cytometry and immunoblotting. The effects of trophoblastic mtDNA on the endothelium were further analysed in vivo using enzyme-linked immunosorbent assay (ELISA) and vascular reactivity assay. The effects of mtDNA on vascular phenotypes were also tested on NLRP3 knockout mice. RESULTS: Elevated interleukin (IL)-1ß in PE sera was accompanied by NLRP3 inflammasome activation in cord tissues. In vitro and in vivo experiments revealed that the release of trophoblastic mtDNA could damage the endothelium via NLRP3 activation, resulting in the overexpression of NLRP3, caspase-1 p20, IL-1ß p17, and gasdermin D (GSDMD); reduced endothelial nitric oxide synthase (eNOS) levels; and impaired vascular relaxation. Flow cytometric analysis confirmed that extensive cell death was induced by mtDNA, and simultaneously, a more pronounced pro-apoptotic effect was caused by hypoxia-treated trophoblastic mtDNA. The NLRP3 knockout or pharmacologic NLRP3 inhibition partially reversed tumour necrosis factor-α (TNF-α) and IL-1ß levels and endothelium-dependent vasodilation in mice. CONCLUSION: These findings demonstrate that trophoblastic mtDNA induced NLRP3/caspase-1/IL-1ß signalling activation, eNOS-related endothelial injury, and vasodilation dysfunction in PE.

Traceability and identification of fish gelatin from seven cyprinid fishes by high performance liquid chromatography and high-resolution mass spectrometry.

The broad application prospect of fish gelatin makes the traceability and identification of fish gelatin imminent. High performance liquid chromatography and high-resolution mass spectrometry (HPLC-MS/MS) was used to identify fish gelatins in seven commercial cyprinid fishes, namely, black carp, grass carp, silver carp, bighead carp, common carp, crucian carp, and Wuchang bream. By comparison with theoretical mammalian collagen (bovine and porcine collagen), the common and unique theoretical peptides were found in the collagen of grass carp, silver carp, and crucian carp, respectively. HPLC-MS/MS results showed that 7 common characteristic peptides were obtained from seven cyprinid fish gelatins. Moreover, 44, 36, and 42 unique characteristic peptides were detected in the gelatins of grass carp, silver carp, and crucian carp, respectively. The combined use of common and unique characteristic peptides could improve the accuracy and authenticity of traceability and identification of fish gelatin in comparison with mammalian gelatin.

Who Wants to Shop With You: Joint Product-Participant Recommendation for Group-Buying Service.

Recent years have witnessed the great success of group buying (GB) in social e-commerce, opening up a new way of online shopping. In this business model, a user can launch a GB as an initiator to share her interested product with social friends. The GB is clinched once enough friends join in as participants to copurchase the shared product. As such, a successful GB depends on not only whether the initiator can find her interested product but also whether the friends are willing to join in as participants. Most existing recommenders are incompetent in such complex scenario, as they merely seek to help users find their preferred products and cannot help identify potential participants to join in a GB. To this end, we propose a novel joint product-participant recommendation (J2PRec) framework, which recommends both candidate products and participants for maximizing the success rate of a GB. Specifically, J2PRec first designs a relational graph embedding module, which effectively encodes the various relations in GB for learning enhanced user and product embeddings. It then jointly learns the product and participant recommendation tasks under a probabilistic framework to maximize the GB likelihood, i.e., boost the success rate of a GB. Extensive experiments on three real-world datasets demonstrate the superiority of J2PRec for GB recommendation.

From Fish Scale Gelatin to Tyrosinase Inhibitor: A Novel Peptides Screening Approach Application.

Bioaffinity ultrafiltration combined with LC-Orbitrap-MS/MS was applied for the first time to achieve rapid screening and identification of tyrosinase inhibitory peptides (TYIPs) from grass carp scale gelatin hydrolysates. The binding mode of TYIPs with tyrosinase was investigated by molecular docking technology. The whitening effect of TYIPs was further studied by evaluating the tyrosinase activity and melanin content in mouse B16F10 cells. Four new TYIPs were screened from hydrolysates, among which DLGFLARGF showed the strongest tyrosinase inhibition with an IC50 value of 3.09 mM. Molecular docking showed that hydrogen bonds were the main driving force in the interaction between the peptide DLGFLARGF and tyrosinase. The addition of DLGFLARGF significantly inhibited the tyrosinase activity and melanin production of B16F10 melanoma cells. These results suggest that DLGFLARGF is a promising skin whitening agent for the treatment of potential pigment-related diseases.

Flavor, antimicrobial activity and physical properties of gelatin film incorporated with of ginger essential oil.

Adding essential oil into the gelatin-based film can enhance the antibacterial activity of the film, but excessive amounts of addition will bring the film an unpleasant flavor and reduce its mechanical performance. Hence, we prepared functional gelatin-based films by incorporating low content of ginger essential oil (GEO). The flavor of GEO was not detected from the films containing less than 1% GEO. The antimicrobial activity of films was found to be proportional to GEO content. As GEO content increased from 0 to 1%, the value of water vapor permeability (WVP) and elongation at break (EAB) increased, whereas the value of tensile strength (TS) of film decreased. The Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy analysis revealed the vibration of gelatin film was affected by adding low content of essential oil. Surface morphologies demonstrated oil droplets and a discontinuous structure, and cross-section morphologies proved the formation of a loose structure as GEO was incorporated in the film through SEM. Sensory evaluation revealed that composite films incorporated with 0.5% GEO exhibited the best performance. The resulting films can be used as antimicrobial packaging materials with good physical properties and sensory performance.

[Characteristics of soil anti-scouribility in gully head wall of grass-covering on the gullied Loess Plateau, Northwest China]. / 黄土高塬沟壑区草地沟头立壁土壤抗冲性特征.

Vegetation restoration in the Chinese Loess Plateau has significantly changed soil erosion process of gully head wall. In order to investigate the characteristics and controlling factors of soil anti-scour properties of gully head covered by grasses, we carried out indoor undamaged soil trench scouring tests. By using barren gully head as the control, the physical and chemical properties and anti-scouring characteristics of soil in different soil layers (0-10, 10-20, 20-40, 40-60, 60-80, 80-100 cm) of the vertical wall of gully with grass cover were analyzed. The results showed that water-stable aggregate content and cohesion in barren and grass-covering gully head decreased with soil depth. Soil organic matter content and soil anti-scouribility coefficient in barren gully head decreased with soil depth, while the two indicators for gully head covered by grass increased firstly and then decreased with soil depth, with the maximum value (24.30 g·kg-1 and 58.86 L·g-1) in 10-20 cm soil layer. Meanwhile, the soil anti-scouring coefficient in each soil layer of grass-covering gully head was 1.7-9.3 times of that in soil layer of barren gully head. Soil organic matter content, water-stable aggregate content, cohesion and root length density all presented significantly positive correlation with soil anti-scouribility, among which soil organic matter content had the highest coefficient (r=0.98). Results of this study might provide basic data for the study of headcut erosion mechanism in Loess Plateau gully region, and scientific basis for effective control of soil and water loss in this region.

Knockdown of rno_circRNA_009194 Improves Outcomes in Traumatic Brain Injury Rats through Inhibiting Voltage-Gated Sodium Channel Nav1.3.

Excessive activation of voltage-gated sodium channel Nav1.3 has been recently reported in secondary traumatic brain injury (TBI). However, the molecular mechanisms underlying regulating voltage-gated sodium channel (Nav1.3) have not been well understood. The present study used a TBI rat model induced by a fluid percussion device and performed a circular RNA (circRNA) microarray (n = 3) to profile the altered circRNAs in the hippocampus after TBI. After polymerase chain reaction (PCR) validation, certain circRNAs were selected to investigate the function and mechanism in regulating Nav1.3 in the TBI rat model by intracerebroventricular injection with lentivirus. The neurological outcome was evaluated by Morris water maze test, modified Neurological Severity Score (mNSS), brain water content measurement, and hematoxylin and eosin staining. The related molecular mechanisms were explored with PCR, Western blotting, luciferase reporter, chromatin immunoprecipitation assay, and electrophoretic mobility shift assay (EMSA). A total of 347 circRNAs were observed to be differentially expressed (fold change [FC] ≥ 1.2 and p < 0.05) after TBI, including 234 up-regulated and 113 down-regulated circRNAs. Among 10 validated circRNAs, we selected circRNA_009194 with the maximized up-regulated fold change (n = 5, FC = 4.45, p < 0.001) for the in vivo functional experiments. Down-regulation of circRNA_009194 resulted in a 27.5% reduced mNSS in rat brain (n = 6, p < 0.01) after TBI and regulated the expression levels of miR-145-3p, Sp1, and Nav1.3, which was reversed by sh-miR-145-3p or Sp1/Nav1.3 overexpression (n = 5, p < 0.05). Mechanistically, circRNA_009194 might act as a sponge for miR-145-3p to regulate Sp1-mediated Nav1.3. This study demonstrated that circRNA_009194 knockdown could improve neurological outcomes in TBI in vivo by inhibiting Nav1.3, directly or indirectly.

Epidemiological and clinical characteristics of melioidosis in Haikou City in 2000 - 2020 / 中华地方病学杂志

Objective:To understand the epidemiological and clinical characteristics of melioidosis in Haikou City, to rise the people's awareness of melioidosis and to provide basis for prevention and control of the disease.Methods:The clinical data of 254 patients with melioidosis treated in 4 Class A tertiary hospitals in Haikou City from January 2000 to September 2020 were collected, and the epidemiological characteristics, clinical manifestations, infection site, prognosis and drug sensitivity were retrospectively analyzed.Results:Among 254 patients with melioidosis, 226 males (88.98%) and 28 females (11.02%), and the gender ratio was 8.07 ∶ 1.00. Farmers were the main occupation, accounting for 37.80% (96/254). The median age was 53 years old, mainly in 41 - 80 years old, accounting for 83.46% (212/254). Han nationality was the most, accounting for 89.76% (228/254). The onset season was mainly in summer and autumn, and the peak was from August to October (117 cases). Patients were mainly distributed in coastal areas, among which Haikou City (49 cases) was the most, followed by Dongfang City (46 cases), Danzhou City (23 cases) and Wenchang City (21 cases). Totally 196 cases (77.17%) had basic diseases, diabetes was the most common (162 cases). The main symptoms of admission were fever (211 cases), followed by cough (108 cases) and expectoration (88 cases). The infection sites were mainly blood (104 cases, 40.94%), lung (60 cases, 23.62%), liver and spleen (32 cases, 12.60%). Totally 195 patients were treated with sensitive antibiotics, at discharge, 37 cases (18.97%) were cured, 129 cases (66.15%) improved, 18 cases (9.23%) did not heal, 7 cases (3.59%) died and 4 cases (2.05%) were discharged voluntarily. Results of drug sensitivity tests from 2010 to 2020 showed that the sensitivity rates of Burkholderia pseudomallei to imipenem (142 cases), meropenem (16 cases) and ceftazidime (141 cases) were all 100.00%, and the sensitivity rates of doxycycline (25 cases) and compound sulfamethoxazole (142 cases) were 92.00% (23/25) and 99.30% (141/142), respectively. Conclusions:Males, farmers, middle-aged and elderly people and people with diabetes and other basic diseases are the high incidence population of melioidosis in Haikou City. The incidence peak is in summer and autumn. The common clinical manifestations are fever, pulmonary infection, abscess of liver and spleen, etc. In the treatment, Burkholderia pseudomallei is more sensitive to imipenem, meropenem and ceftazidime.

[Exosomal microRNAs: an emerging player in systemic lupus erythematosus].

Exosomes are nanometer-sized membranous extracellular vesicles that can be secreted by almost all types of cells in the body. Exosomes are involved in cell-to-cell communication through autocrine and paracrine forms. Exosomal microRNAs (miRNAs) are stable in plasma, urine and other body fluids, and have various biological functions. They play an irreplaceable role in the occurrence, development, immune regulation of systemic lupus erythematosus (SLE). Recent studies have proposed that exosomal miRNAs have promising application prospects in the pathogenesis, early diagnosis, and treatment of SLE. Therefore, this review aims to introduce the current research progress on exosomal miRNAs in SLE and analyze their potential application value.

Short-term efficacy of superficial X-ray treatment for infantile maxillofacial hemangioma.

OBJECTIVES: This study aimed to explore the short-term clinical efficacy and factors influencing low-dose superficial X-ray for treating infantile maxillofacial hemangioma. METHODS: Retrospective analysis was conducted on 161 cases of infants with maxillofacial hemangioma treated with superficial X-ray in the Laser Center of Dermatology Department of Sichuan Provincial People's Hospital from January 2015 to December 2017. Clinical efficacy was analyzed by comparing the photos before and after treatment. Patients were further divided into groups according to different genders, age at the start of treatment, preterm birth or low birth weight, hemangioma site, longest diameter of hemangioma, and type of hemangioma to analyze whether differences existed in clinical efficacy and therapeutic dose between different groups. RESULTS: Twelve months after the end of treatment, the overall cure rate was 93.8%, and the significant efficiency was 97.5%. The clinical efficacy was related to the age of children at the beginning of treatment and the type of hemangioma (P<0.05). The clinical efficacy of children aged less than or equal to 12 months and superficial hemangioma group was better than that of children aged more than 12 months and deep subtype or mixed hemangioma group, respectively. Therapeutic doses associa-ted with hemangioma treatment with diameter, category, age (P<0.05), diameter greater than or equal to 4 cm hemangioma group, the mixed type or deep in the group, the children older than 12 months hemangioma group, respectively, the dia-meter is less than 4 cm hemangioma, superficial hemangioma group and age less than or equal to 12 months hemangioma total treatment group exposure dose is greater. CONCLUSIONS: Low-dose superficial X-ray is safe and effective for the treatment of infantile maxillofacial hemangioma. Age and type of hemangioma at the time of treatment are the factors influencing therapeutic dose and clinical efficacy.

Update on the management of fungal keratitis.

PURPOSE: The aim of this article is to introduce the recent advance on the studies of fungal keratitis published over past 5 years. METHODS: We performed literature review of articles published on PubMed, Google Scholar, CNKI and Web of Science relevant to the diagnosis, pathogenesis and novel treatment of fungal keratitis. RESULTS: Excessive inflammation can lead to stromal damage and corneal opacification, hence the research on immune mechanism provides many potential therapeutic targets for fungal keratitis. Many researchers discussed the importance of earlier definitive diagnosis and were trying to find rapid and accurate diagnostic methods of pathogens. Develop new drug delivery systems and new routes of administration with better corneal penetration, prolonged ocular residence time, and better mucoadhesive properties is also one of the research hotspots. Additionally, many novel therapeutic agents and methods have been gradually applied in clinical ophthalmology. CONCLUSION: The diagnosis and treatment of fungal keratitis are still a challenge for ophthalmologist, and many researches provide new methods to conquer these problems.

Protective effects of human umbilical cord mesenchymal stem cells on retinal ganglion cells in mice with acute ocular hypertension.

AIM: To observe the protective effect of human umbilical cord mesenchymal stem cells (hucMSCs) on retinal ganglion cells (RGCs) injury in mice with acute ocular hypertension (AOH). METHODS: Fifty-six adult male C57BL/6 mice were randomly divided into four groups: normal group, AOH group, hucMSCs group, normal saline (NS) group. Left eye of mice was induced by 90 mm Hg intraocular pressure for 1h to establish AOH model. hucMSCs 1×105/µL, 1 µL or NS 1 µL was injected into the vitreous body the next day. CM-Dil fluorescent dye was used to label the 3rd generation of hucMSCs, for tracing the cells in the vitreous cavity of mice. Seven days after the model established, hematoxylin-eosin (HE) staining was used to observe the thickness of the inner retina layer in four groups. Numbers and loss rate of RGCs were evaluated by counting Brn-3a positive cells stained by immunofluorescencein. RESULTS: On the 7th day after AOH established, labeled hucMSCs were found in the vitreous cavity. HE staining showed that the thickness of retinal inner layer in AOH group was significantly lower than that in normal group and hucMSCs group (P<0.05), same as that in NS group (P>0.05). Compared with AOH group, the RGCs in normal group was significantly higher; RGCs number increased in hucMSCs group and the loss rate was lower (P<0.05). Injection of NS had no protective effect on RGCs. CONCLUSION: In AOH mouse model, vitreous injection of hucMSCs have shown a protection for RGCs.

Microbial transglutaminase (MTGase) modified fish gelatin-γ-polyglutamic acid (γ-PGA): Rheological behavior, gelling properties, and structure.

Fish gelatin (FG) has been extensively studied as a potential substitute for mammal gelatin. However, FG often requires different modification methods to change its physical and chemical properties due to its low gelling properties. Here, γ-polyglutamic acid (γ-PGA) and microbial transglutaminase (MTGase) were combined to modify FG to improve its gelling properties. The γ-PGA at 0.04% (w/v) and MTGase of different concentrations (0.02-0.08%, w/v) were used to modify FG, and the effects of complex modification on the gelling properties and structure of FG were studied. When the MTGase content was 0.08% (w/v), FG had the best gelling properties. In addition, the complex modification of MTGase and γ-PGA hindered the formation of the triple helix during the FG gel process. This reduced the gel rate, but significantly increased its viscosity. A schematic model was also proposed to illustrate the complex modifications of FG by MTGase and γ-PGA.

Lung injury induced by short-term mechanical ventilation with hyperoxia and its mitigation by deferoxamine in rats.

BACKGROUND: Long-term mechanical ventilation with hyperoxia can induce lung injury. General anesthesia is associated with a very high incidence of hyperoxaemia, despite it usually lasts for a relatively short period of time. It remains unclear whether short-term mechanical ventilation with hyperoxia has an adverse impact on or cause injury to the lungs. The present study aimed to assess whether short-term mechanical ventilation with hyperoxia may cause lung injury in rats and whether deferoxamine (DFO), a ferrous ion chelator, could mitigate such injury to the lungs and explore the possible mechanism. METHODS: Twenty-four SD rats were randomly divided into 3 groups (n = 8/group): mechanical ventilated with normoxia group (MV group, FiO2 = 21%), with hyperoxia group (HMV group, FiO2 = 90%), or with hyperoxia + DFO group (HMV + DFO group, FiO2 = 90%). Mechanical ventilation under different oxygen concentrations was given for 4 h, and ECG was monitored. The HMV + DFO group received continuous intravenous infusion of DFO at 50 mg•kg- 1•h- 1, while the MV and HMV groups received an equal volume of normal saline. Carotid artery cannulation was carried out to monitor the blood gas parameters under mechanical ventilation for 2 and 4 h, respectively, and the PaO2/FiO2 ratio was calculated. After 4 h ventilation, the right anterior lobe of the lung and bronchoalveolar lavage fluid from the right lung was sampled for pathological and biochemical assays. RESULTS: PaO2 in the HMV and HMV + DFO groups were significantly higher, but the PaO2/FiO2 ratio were significantly lower than those of the MV group (all p < 0.01), while PaO2 and PaO2/FiO2 ratio between HMV + DFO and HMV groups did not differ significantly. The lung pathological scores and the wet-to-dry weight ratio (W/D) in the HMV and HMV + DFO groups were significantly higher than those of the MV group, but the lung pathological score and the W/D ratio were reduced by DFO (p < 0.05, HMV + DFO vs. HMV). Biochemically, HMV resulted in significant reductions in Surfactant protein C (SP-C), Surfactant protein D (SP-D), and Glutathion reductase (GR) levels and elevation of xanthine oxidase (XOD) in both the Bronchoalveolar lavage fluid and the lung tissue homogenate, and all these changes were prevented or significantly reverted by DFO. CONCLUSIONS: Mechanical ventilation with hyperoxia for 4 h induced oxidative injury of the lungs, accompanied by a dramatic reduction in the concentrations of SP-C and SP-D. DFO could mitigate such injury by lowering XOD activity and elevating GR activity.