Effects of predictive nursing interventions on pressure ulcer in older bedridden patients: A meta-analysis.

To evaluate the effect of predictive nursing interventions on pressure ulcers in elderly bedridden patients by meta-analysis. Applied computer searches of PubMed, Embase, Google Scholar, Cochrane Library, China National Knowledge Infrastructure and Wanfang databases for randomised controlled trials (RCTs) on the effect of predictive nursing in preventing pressure ulcers in elderly bedridden patients from the database inception to November 2023. Two researchers independently screened the literature, extracted data and performed quality assessment based on inclusion and exclusion criteria. Stata 17.0 software was utilised for data analysis. Eighteen RCTs involving 6504 patients were finally included. The analysis revealed the implementation of predictive nursing interventions had a significant advantage in reducing the incidence of pressure ulcers in elderly bedridden patients compared with conventional nursing (odds ratio [OR] = 0.20, 95% confidence interval [CI]: 0.15-0.28, p < 0.001), while the patients' satisfaction with nursing care was higher (OR = 3.70, 95% CI: 2.99-4.57, p < 0.001). This study shows that the implementation of a predictive nursing interventions for elderly bedridden patients can effectively reduce the occurrence of pressure ulcers and significantly improve patients' satisfaction with nursing care, which is worthy of clinical promotion and application.

SDF-1 inhibits the dedifferentiation of islet ß cells in hyperglycaemia by up-regulating FoxO1 via binding to CXCR4.

Islet ß cell dedifferentiation is one of the most important mechanisms in the occurrence and development of diabetes. We studied the possible effects of chemokine stromal cell-derived factor-1 (SDF-1) in the dedifferentiation of islet ß cells. It was noted that the number of dedifferentiated islet ß cells and the expression of SDF-1 in pancreatic tissues significantly increased with diabetes. In islet ß cell experiments, inhibition of SDF-1 expression resulted in an increase in the number of dedifferentiated cells, while overexpression of SDF-1 resulted in a decrease. This seemed to be contradicted by the effect of diabetes on the expression of SDF-1 in pancreatic tissue, but it was concluded that this may be related to the loss of SDF-1 activity. SDF-1 binds to CXCR4 to form a complex, which activates and phosphorylates AKT, subsequently increases the expression of forkhead box O1 (FOXO1), and inhibits the dedifferentiation of islet ß cells. This suggests that SDF-1 may be a novel target in the treatment of diabetes.

Impact of the COVID-19 pandemic on congenital diaphragmatic hernia patients: a single-center retrospective study.

PURPOSE: To investigate the impact of COVID-19 on the treatment of children with congenital diaphragmatic hernia (CDH). METHODS: We retrospectively collected and compared the data of patients with CDH admitted between January 1, 2020 and December 31, 2021(study group) with the CDH patients admitted before the pandemic between January 1, 2018 and December 31, 2019 (control group). RESULTS: During the pandemic, 41 patients with CDH diagnosed prenatally were transferred to our hospital, and 40 underwent surgical repair. The number of patients treated in our hospital increased by 24.2% compared with the 33 patients before the pandemic. During the pandemic, the overall survival rate, postoperative survival rate and recurrence rate were 85.4%, 87.5% and 7.3%, respectively, and there were no significant differences compared with the control group (75.8%, 83.3% and 9.1%, respectively). The average length of hospital stay in patients admitted during the pandemic was longer than that in the control group (31 days vs. 16 days, P < 0.001), and the incidence of nosocomial infection was higher than that in the control group (19.5% vs. 3%, P = 0.037). CONCLUSIONS: CDH patients confirmed to be SARS-CoV-2 infection-free can receive routine treatment. Our data indicate that the implementation of protective measures during the COVID-19 pandemic, along with appropriate screening and case evaluation, do not have a negative impact on the prognosis of children.

Visceral fat area to appendicular muscle mass ratio as a predictor for nonalcoholic fatty liver disease independent of obesity.

OBJECTIVE: Obesity and sarcopenia are known to be closely related to nonalcoholic fatty liver disease (NAFLD). We attempted to explore the combined influence of fat and muscle tissue on NAFLD by using visceral fat area to appendicular muscle mass ratio (VAR) as a novel parameter. MATERIAL AND METHODS: In this cross-sectional study, a total of 3255 adults (1399 men and 1856 women) coming for a health examination were enrolled. NAFLD was diagnosed using ultrasound and VAR was measured by bioelectrical impedance analyzer. RESULTS: The prevalence of NAFLD was 46.5% in men and 26.6% in women. VAR differed significantly between subjects with and without NAFLD (4.27 vs. 3.26 in men, 7.89 vs. 5.01 in women, respectively, p < .001). Logistic regression analysis determined VAR as a risk factor for NAFLD, and the multivariable-adjusted odds ratios in the highest VAR quartile was 9.57 (95%CI: 5.98-15.30) for men and 12.37 (95%CI: 6.37-24.05) for women. From the receiver operating characteristic analysis, the area under the curve was 0.767 and 0.834, with the suitable cut-off VAR value of 3.469 and 6.357 for men and women, respectively. To control the influence of obesity, all subjects were stratified according to their BMI. For each BMI group, individuals with VAR above the cut-off value had significant higher prevalence and risk of NAFLD, with odds ratios ranging from 1.76 to 4.75. CONCLUSIONS: Increased VAR is strongly associated with higher risk of NAFLD in both sexes independent of obesity and can serve as a screening reference for NAFLD.

Screening the Key Region of Sunlight Regulating the Flavonoid Profiles of Young Shoots in Tea Plants (Camellia sinensis L.) Based on a Field Experiment.

Both UV and blue light have been reported to regulate the biosynthesis of flavonoids in tea plants; however, the respective contributions of the corresponding regions of sunlight are unclear. Additionally, different tea cultivars may respond differently to altered light conditions. We investigated the responses of different cultivars ('Longjing 43', 'Zhongming 192', 'Wanghai 1', 'Jingning 1' and 'Zhonghuang 2') to the shade treatments (black and colored nets) regarding the biosynthesis of flavonoids. For all cultivars, flavonol glycosides showed higher sensitivity to light conditions compared with catechins. The levels of total flavonol glycosides in the young shoots of different tea cultivars decreased with the shade percentages of polyethylene nets increasing from 70% to 95%. Myricetin glycosides and quercetin glycosides were more sensitive to light conditions than kaempferol glycosides. The principal component analysis (PCA) result indicated that shade treatment greatly impacted the profiles of flavonoids in different tea samples based on the cultivar characteristics. UV is the crucial region of sunlight enhancing flavonol glycoside biosynthesis in tea shoots, which is also slight impacted by light quality according to the results of the weighted correlation network analysis (WGCNA). This study clarified the contributions of different wavelength regions of sunlight in a field experiment, providing a potential direction for slightly bitter and astringent tea cultivar breeding and instructive guidance for practical field production of premium teas based on light regimes.

Exogenous activation of cannabinoid-2 receptor modulates TLR4/MMP9 expression in a spinal cord ischemia reperfusion rat model.

BACKGROUND: Cannabinoid-2 receptor (CB2R) plays an important role in the cascading inflammation following ischemic injury. The toll-like receptors 4 (TLR4)/matrix metalloproteinase 9 (MMP9) signal pathway is involved in blood-brain barrier dysfunction induced by ischemia stroke. The aim of this study is to investigate the roles of exogenous activation of CB2R on attenuating neurological deficit and blood-spinal cord barrier (BSCB) disruption during rat spinal cord ischemia reperfusion (I/R) injury, through modulation of the TLR4/MMP9 axis. METHODS: Animals were intraperitoneally pretreated with TLR4 inhibitor TAK-242, CB2R agonist JWH-133 with or without CB2R antagonist AM630, or equivalent volume of vehicle 1 h before undergoing 14-min occlusion of descending aorta or sham operation. One, two, three, and 7 days after reperfusion, hindlimb locomotor function was evaluated with Basso, Beattie, and Bresnahan (BBB) Locomotor Scale, BSCB integrity was detected by measurement of Evans blue (EB) extravasation and spinal cord edema. The protein expression levels of CB2R, tight junction protein Zonula occluden-1 (ZO-1), TLR4, MMP9, MyD88, NF-κB p65, and NF-κB p-p65 were determined by western blot. The MMP9 activity was analyzed by gelatin zymography. Double immunofluorescence staining was used to identify the perivascular localization of CB2R, TLR4, MMP9, and reactive astrocytes, as well as the colocalization of CB2R, TLR4, and MMP9 with reactive astrocytes. RESULTS: JWH-133 pretreatment attenuated hindlimb motor functional deficit and BSCB leakage, along with preventing downregulation of ZO-1 and upregulation of TLR4/MMP9, similar to the effects of TAK-242 preconditioning. JWH-133 or TAK-242 pretreatment reduced the perivascular expression of TLR4/MMP9 and reactive astrocytes following injury. JWH-133 pretreatment also downregulated MyD88/NF-κB level, MMP9 activity, and the astrocytic TLR4/MMP9 after I/R injury. CONCLUSIONS: Exogenous activation of CB2R by JWH-133 attenuated neurological deficit and BSCB disruption after spinal cord I/R injury via inhibition of TLR4/MMP9 expression.

Effect of low-temperature vacuum heating on physicochemical properties of sturgeon (Acipenser gueldenstaedti) fillets.

BACKGROUND: Sturgeon is popular for its nutritious value and its taste. However, sturgeon fillets are traditionally heated in 100 °C boiling water, resulting in unfavorable taste and with a negative effect on the quality. This study considered the effect of combinations of vacuum and low-temperature treatments (LTVH groups) on sturgeon fillets compared with the traditional heat treatment (TC groups). RESULTS: The results show that the LTVH groups had lower cooking-loss rates. All LTVH fillets were changed to a white color, and appeared 'done', as did the TC fillets. The LTVH and TC methods gave rise to significant differences in texture: the springiness of the LTVH groups decreased with heating time, and decreased rapidly in the TC groups (P < 0.05); hardness and chewiness increased with time and temperature in the LTVH groups, but decreased in the TC groups. More compact and denser gaps were observed in LTVH70 groups and TC groups. Less protein and lipid oxidation was evident in LTVH groups, including more myofibril protein solubility; there was less protein aggregation, fewer thiobarbituric acid reactive substance, and Schiff base. CONCLUSION: Vacuum and low-temperature treated sturgeon fillets can be served as a good alternative. This treatment caused slight tissue damage and less proteolysis and lipid oxidation, which is beneficial for the quality of aquatic products.

A sclerocornea-associated RAD21 variant induces corneal stroma disorganization.

Sclerocornea is a cornea opacification disorder. Disorganized corneal stroma fibrils are observed in patients' cornea. Previously we identified a RAD21C1348T variant that is associated with a peripheral sclerocornea pedigree. To explore whether this RAD21 variant can induce sclerocornea-related phenotype, and to investigate the possible mechanisms of such phenotype, the orthologous rad21 wild-type and variant mRNAs were injected into Xenopus laevis embryos and the developed eyes were subjected for histological examination. Transmission electron microscopy was applied for corneal stroma organization check. rad21 is highly expressed in the eye region during X. laevis development. Disrupted eye development was observed in the rad21 variant injected embryos. Disorganized corneal stroma and decreased diameters of collagen fibrils were observed in the rad21 variant injected X. laevis eyes. These eye defects can be rescued by overexpression of the wild-type rad21. Histological examination found stroma attracting center, a key structure in X. laevis corneal development, was impaired in rad21 variant injected embryos. Our results suggest a key role of RAD21 during corneal development. Our data indicates the RAD21R450C variant contributes to peripheral sclerocornea by disturbing collagen fibril organization in the corneal stroma.

rTMS combined with motor training changed the inter-hemispheric lateralization.

Repetitive transcranial magnetic stimulation combined with motor training (rTMS-MT) can be an effective method for enhancing motor function. However, the effects of rTMS-MT on inter-hemispheric lateralization remain unclear. Nineteen healthy volunteers were recruited. The volunteers were randomized to receive 2 weeks of rTMS-MT or MT to improve the motor function of the nondominant hand. Hand dexterity was tested by the Nine-Hole Peg Test. Resting motor threshold (RMT), motor evoked potentials (MEP) and electroencephalography (EEG) in the resting state with eyes closed were recorded, to calculate inter-hemispheric lateralization before and after rTMS-MT or MT. rTMS-MT and MT improved the dexterity and MEP amplitude of the nondominant hand. Furthermore, there were significant changes in the lateralization of not only power spectral density, but also information transmission efficiency between regions following rTMS-MT, especially between the central cortices of both hemispheres. However, although the lateralization change of the power spectral density between the central cortices was observed following MT, there was no such change for information transmission efficiency between any cortices. These results suggested that rTMS-MT could modulate inter-hemispheric lateralization. Changes in inter-hemispheric lateralization might be an important neural mechanism by which rTMS-MT improves motor function. These results could be helpful for understanding the brain mechanism of rTMS-MT.

Functional Analysis of the Soybean GmCDPK3 Gene Responding to Drought and Salt Stresses.

Plants have a series of response mechanisms to adapt when they are subjected to external stress. Calcium-dependent protein kinases (CDPKs) in plants function against a variety of abiotic stresses. We screened 17 CDPKs from drought- and salt-induced soybean transcriptome sequences. The phylogenetic tree divided CDPKs of rice, Arabidopsis and soybean into five groups (I-V). Cis-acting element analysis showed that the 17 CDPKs contained some elements associated with drought and salt stresses. Quantitative real-time PCR (qRT-PCR) analysis indicated that the 17 CDPKs were responsive after different degrees of induction under drought and salt stresses. GmCDPK3 was selected as a further research target due to its high relative expression. The subcellular localization experiment showed that GmCDPK3 was located on the membrane of Arabidopsis mesophyll protoplasts. Overexpression of GmCDPK3 improved drought and salt resistance in Arabidopsis. In the soybean hairy roots experiment, the leaves of GmCDPK3 hairy roots with RNA interference (GmCDPK3-RNAi) soybean lines were more wilted than those of GmCDPK3 overexpression (GmCDPK3-OE) soybean lines after drought and salt stresses. The trypan blue staining experiment further confirmed that cell membrane damage of GmCDPK3-RNAi soybean leaves was more severe than in GmCDPK3-OE soybean lines. In addition, proline (Pro) and chlorophyll contents were increased and malondialdehyde (MDA) content was decreased in GmCDPK3-OE soybean lines. On the contrary, GmCDPK3-RNAi soybean lines had decreased Pro and chlorophyll content and increased MDA. The results indicate that GmCDPK3 is essential in resisting drought and salt stresses.

Production of soluble bioactive mouse leukemia inhibitory factor from Escherichia coli using MBP tag.

Embryonic stem cells and induced pluripotent stem cells depend on one of cytokines called leukemia inhibitory factor (LIF) to retain their undifferentiated state and pluripotency. Nevertheless, further progresses of stem cell scientific investigation and its possible application are limited owing to the expense of commercial LIF. Here we introduced a simple, practical and high level expression of MBP-mouse LIF through Escherichia coli system which was bioactive. The mLIF cDNA was inserted into vector of pMAL-C2X in order to generate N-terminal MBP-mLIF recombinant proteins in the cytoplasm of Escherichia coli. MBP-mLIF as a soluble form was expressed. One-step purification through gravitational affinity chromatography was accomplished to acquire high purity (>92%) MBP-mLIF. The MBP-mLIF products specifically suppressed the growth of M1cells in a dose-dependent pattern. MBP-mLIF also was proved the ability to maintain the pluripotency of iPSCs. These outcomes revealed that the N-end MBP tags of the MBP-mLIF did not obstruct mLIF bioactivity. This method to generate recombinant MBP-mLIF is a simple, practical, economical and user-friendly protocol.

The Maize WRKY Transcription Factor ZmWRKY40 Confers Drought Resistance in Transgenic Arabidopsis.

Abiotic stresses restrict the growth and yield of crops. Plants have developed a number of regulatory mechanisms to respond to these stresses. WRKY transcription factors (TFs) are plant-specific transcription factors that play essential roles in multiple plant processes, including abiotic stress response. At present, little information regarding drought-related WRKY genes in maize is available. In this study, we identified a WRKY transcription factor gene from maize, named ZmWRKY40. ZmWRKY40 is a member of WRKY group II, localized in the nucleus of mesophyll protoplasts. Several stress-related transcriptional regulatory elements existed in the promoter region of ZmWRKY40. ZmWRKY40 was induced by drought, high salinity, high temperature, and abscisic acid (ABA). ZmWRKY40 could rapidly respond to drought with peak levels (more than 10-fold) at 1 h after treatment. Overexpression of ZmWRKY40 improved drought tolerance in transgenic Arabidopsis by regulating stress-related genes, and the reactive oxygen species (ROS) content in transgenic lines was reduced by enhancing the activities of peroxide dismutase (POD) and catalase (CAT) under drought stress. According to the results, the present study may provide a candidate gene involved in the drought stress response and a theoretical basis to understand the mechanisms of ZmWRKY40 in response to abiotic stresses in maize.

Maize WRKY Transcription Factor ZmWRKY106 Confers Drought and Heat Tolerance in Transgenic Plants.

WRKY transcription factors constitute one of the largest transcription factor families in plants, and play crucial roles in plant growth and development, defense regulation and stress responses. However, knowledge about this family in maize is limited. In the present study, we identified a drought-induced WRKY gene, ZmWRKY106, based on the maize drought de novo transcriptome sequencing data. ZmWRKY106 was identified as part of the WRKYII group, and a phylogenetic tree analysis showed that ZmWRKY106 was closer to OsWRKY13. The subcellular localization of ZmWRKY106 was only observed in the nucleus. The promoter region of ZmWRKY106 included the C-repeat/dehydration responsive element (DRE), low-temperature responsive element (LTR), MBS, and TCA-elements, which possibly participate in drought, cold, and salicylic acid (SA) stress responses. The expression of ZmWRKY106 was induced significantly by drought, high temperature, and exogenous abscisic acid (ABA), but was weakly induced by salt. Overexpression of ZmWRKY106 improved the tolerance to drought and heat in transgenic Arabidopsis by regulating stress-related genes through the ABA-signaling pathway, and the reactive oxygen species (ROS) content in transgenic lines was reduced by enhancing the activities of superoxide dismutase (SOD), peroxide dismutase (POD), and catalase (CAT) under drought stress. This suggested that ZmWRKY106 was involved in multiple abiotic stress response pathways and acted as a positive factor under drought and heat stress.

Exploration micromechanism of VP35 IID interaction and recognition dsRNA: A molecular dynamics simulation.

Multifunctional viral protein (VP35) encoded by the highly pathogenic Ebola viruses (EBOVs) can antagonize host double-stranded RNA (dsRNA) sensors and immune response because of the simultaneous recognition of dsRNA backbone and blunt ends. Mutation of select hydrophobic conserved basic residues within the VP35 inhibitory domain (IID) abrogates its dsRNA-binding activity, and impairs VP35-mediated interferon (IFN) antagonism. Herein the detailed binding mechanism between dsRNA and WT, single mutant, and double mutant were investigated by all-atom molecular dynamics (MD) simulation and binding energy calculation. R312A/R322A double mutations results in a completely different binding site and orientation upon the structure analyses. The calculated binding free energy results reveal that R312A, R322A, and K339A single mutations decrease the binding free energies by 17.82, 13.18, and 13.68 kcal mol-1 , respectively. The binding energy decomposition indicates that the strong binding affinity of the key residues is mainly due to the contributions of electrostatic interactions in the gas phase, where come from the positively charged side chain and the negatively charged dsRNA backbone. R312A, R322A, and K339A single mutations have no significant effect on VP35 IID conformation, but the mutations influence the contributions of electrostatic interactions in the gas phase. The calculated results reveal that end-cap residues which mainly contribute VDW interactions can recognize and capture dsRNA blunt ends, and the central basic residues (R312, R322, and K339) which mainly contribute favorable electrostatic interactions with dsRNA backbone can fix dsRNA binding site and orientation. Proteins 2017; 85:1008-1023. © 2017 Wiley Periodicals, Inc.

Remote Ischemia Preconditioning Attenuates Blood-Spinal Cord Barrier Breakdown in Rats Undergoing Spinal Cord Ischemia Reperfusion Injury: Associated with Activation and Upregulation of CB1 and CB2 Receptors.

BACKGROUND/AIMS: Remote ischemic preconditioning (RIPC) has protective effects on spinal cord ischemia reperfusion (I/R) injury, but the potential mechanisms remain unclear. In our study, the effects and underlying mechanisms of RIPC on blood-spinal cord barrier (BSCB) breakdown following I/R injury were investigated. METHODS: animals underwent intraperitoneal administration with cannabinoid-1 (CB1) receptor antagonist AM251, cannabinoid-2 (CB2) receptor antagonist AM630 or vehicle 15 minutes before three 3-minute occlusion-reperfusion cycles on the right femoral artery or a sham operation. 30 minutes after the preconditioning, aortic arch was exposed with or without 14-minute occlusion. Neurological function was assessed with Tarlov scoring system. The disruption of BSCB was assessed by measuring Evans Blue (EB) extravasation. The expression of tight junction protein occludin was determined by western blot analyses. The expression and localization of CB1 and CB2 receptors were assessed by western blot and immunofluorescence. RESULTS: RIPC attenuated the motor dysfunction, BSCB disruption and downregulation of occludin after I/R injury, which were impaired by blocking CB1 and CB2 receptors. Moreover, RIPC upregulated the elevated perivascular expression of CB1 and CB2 receptors following I/R injury. CONCLUSIONS: These results indicated that RIPC, through activation and upregulation of CB1 and CB2 receptors, was involved in preserving the integrity of BSCB after spinal cord I/R injury.

Molecular dynamics exploration of the binding mechanism and properties of single-walled carbon nanotube to WT and mutant VP35 FBP region of Ebola virus.

VP35 of Ebola viruses (EBOVs) is an attractive potential target because of its multifunction. All-atom molecular dynamics (MD) simulations and Molecular Mechanics Generalized Born surface area (MM/GBSA) energy calculations are performed to investigate the single-walled carbon nanotube (SWCNT) as an inhibitor in wild-type (WT) VP35 as well as in three primary mutants (K248A, I295A, and K248A/I295A) through docking the SWCNT in the first basic patch (FBP) of VP35. The SWCNTs of all the four systems effectively bind to the FBP. Interestingly, the sites and orientations of the SWCNT binding to the I295A mutant and K248A/I295A double mutants change significantly to accommodate the variation of the VP35 conformation. Moreover, the VDW can provide the major forces for affinity binding in all four systems.

[Effects of isovitexin on transient outward potassium current of ventricular myocytes in rats].

To investigate the effects of isovitexin Ⅳ on transient outward potassium current in rat ventricular myocytes. In this study, MTT assay was used to investigate the safe range of isovitexin. The results showed that the IC50 of the drug was in the range of 10-30 µmol•L⁻¹, and the drug concentration of 1-3 µmol•L⁻¹ for the patch clamp test was within the safe range. In addition, the single ventricular myocytes were obtained by single-enzymatic hydrolysis through aortic retrograde perfusion. The transient outward potassium current (Ito) of rat ventricular myocytes was guided and measured by whole-cell patch-clamp technique and the changes of current characteristics were recorded after isovite was applied. When the concentration of IV was less than 0.1 µmol•L⁻¹, there was no significant effect on Ito. However, with the increase in the concentration of IV (≥0.3 µmol•L⁻¹), the peak of Ito was decreased gradually, from (32.32±2.9) pA/pF to （25.83±4.3） pA/pF, 1 µmol•L⁻¹ IV and (19.51±3.5) pA/pF, 3 µmol•L⁻¹ IV respectively, with an inhibition effect in a concentration-dependent manner. In the range of 1-3 µmol•L⁻¹, IV down-regulated the I-V curve of Ito significantly. The activation curve showed that IV can enable the maximum half activation potential (V1/2) to move to the positive direction, and the V1/2 was increased from (19.59±1.6) mV to (22.81±1.7) mV and (28.86±1.4) mV at concentration of 1, 3 µmol•L⁻¹, meanwhile the activation curve moved to the right. However, the maximum half inactivating potential (V1/2) of the steady-state inactivation curve of Ito was significantly decreased from (－51.43±0.99) mV to (－61.81±1.3) mV with concentration of 1 µmol•L⁻¹ and (－71.50±1.4) mV with concentration of 3 µmol•L⁻¹. The inactivation time constant of recovery from inactivation (τ) was up-regulated significantly from (94.89±0.73) ms to (118.5±1.5) ms and (162.4±1.4) ms at concentration of 1, 3 µmol•L⁻¹ respectively. Meanwhile IV could enable the inactivation recovery curve to move to the right, which suggested that it can prolong the recovery time from inactivation of the transient outward potassium channel. In conclusion, isovitexin had a high inhibitory effect on Ito in rat ventricular myocytes.

Increased Vitreous Chemerin Levels Are Associated with Proliferative Diabetic Retinopathy.

PURPOSE: To investigate chemerin in the vitreous bodies of patients with proliferative diabetic retinopathy (PDR) and determine the correlation between the levels of vitreous chemerin and vascular endothelial growth factor (VEGF). METHODS: This study included 17 patients suffering from PDR and vitreous hemorrhage (VH) (group A), 21 patients with PDR and tractional retinal detachment (TRD) (group B) and 25 patients with idiopathic macular holes or preretinal membranes (control group). All vitreous samples were obtained through pars plana vitrectomy. Enzyme-linked immunosorbent assay and Western blot analysis were performed to evaluate the levels of vitreous chemerin and VEGF. RESULTS: Vitreous concentrations of chemerin were significantly higher in PDR patients with VH and TRD than those in the controls [4.82 ng/ml (3.91-6.13) vs. 5.03 ng/ml (4.01-6.15) vs. 2.53 ng/ml (1.53-5.66), p = 0.025]. The ratio of vitreous chemerin to plasma chemerin concentration significantly differed between groups A and B and the control group [4.93% (4.69-5.34) vs. 4.98% (4.63-5.19) vs. 2.58% (1.78-4.58), p < 0.001]. Western blot results indicated that the levels of vitreous chemerin protein in PDR patients significantly increased compared with those in the controls. Spearman correlation analysis further showed that vitreous chemerin levels in patients with PDR were positively correlated with vitreous VEGF levels (r = -0.542, p < 0.001). CONCLUSIONS: Increased vitreous chemerin levels are associated with the development of PDR.

Exploring interaction mechanisms of the inhibitor binding to the VP35 IID region of Ebola virus by all atom molecular dynamics simulation method.

Ebola viruses (EBOVs) cause an acute and serious illness which is often fatal if untreated, and there is no effective vaccine until now. Multifunctional VP35 is critical for viral replication, RNA silencing suppression and nucleocapsid formation, and it is considered as a future target for the molecular biology technique. In the present work, the binding of inhibitor pyrrole-based compounds (GA017) to wild-type (WT), single (K248A, K251A, and I295A), and double (K248A/I295A) mutant VP35 were investigated by all-atom molecular dynamic (MD) simulations and Molecular Mechanics Generalized Born surface area (MM/GBSA) energy calculation. The calculated results indicate that the binding with GA017 makes the binding pocket more stable and reduces the space of the binding pocket. Moreover, the electrostatic interactions (ΔEele) and VDW energy (ΔEvdw) provide the major forces for affinity binding, and single mutation I295A and double mutation K248A/I295A have great influence on the conformation of the VP35 binding pocket. Interestingly, the residues R300-G301-D302 of I295A form a new helix and the sheet formed by the residues V294-I295-H296-I297 disappears in the double mutation K248A/I295A as compared with WT. Moreover, the binding free energy calculations show that I295A and K248A/I295A mutations decrease of absolute binding free energies while K248A and K251A mutations increase absolute binding free energy. Our calculated results are in good agreement with the experimental results that K248A/I295A double mutant results in near-complete loss of compound binding. The obtained information will be useful for design effective inhibitors for treating Ebola virus.

Insights into resistance mechanism of the macrolide biosensor protein MphR(A) binding to macrolide antibiotic erythromycin by molecular dynamics simulation.

Macrolide biosensor protein MphR(A) has been known as a key regulatory protein in metabolite sensing and genetic expression regulating. MphR(A) protein binds to macrolide antibiotic erythromycin (Ery) and releases the gene operon, thus activates expression of the mphA gene and initiates Ery resistance. The two mutant amino acid residues (V66L and V126L) might potentially disrupt Ery binding to MphR(A). In these studies, the binding of macrolide antibiotic Ery to wild type (Wt) MphR(A) and double mutant (V66L/V126L) MphR(A) are explored by molecular dynamics simulations. Compared to the Apo-MphR(A) protein and Wt-MphR(A)-Ery complex, many interesting effects owing to the double mutant (V66L/V126L) are discovered. In the case of Ery, Helix I which plays an important role in transcription shows itself a right-hand α helix in Wt-MphR(A)-Ery, whereas the activated helix is broken down in double mutant-V66L/V126L-MphR(A)-Ery. The calculated results exhibit that the double mutant V66L/V126L reduces the binding affinity of the V66L/V126L-MphR(A) to Ery, resulting in the block of Ery resistance. The binding free energy decomposition analysis reveals that the decrease of the binding affinity for the variant V66L/V126L-MphR(A)-Ery is mainly attributed to the gas phase electrostatic energies. The residue Leu66, Thr154, and Arg122 enhance the binding affinity of V66L/V126L-MphR(A) to Ery. The residues Tyr103 and His147 contributes mainly to binding energies in the Wt-MphR(A)-Ery complex, whereas the two residues have no contribution to the binding free energy inV66L/V126L-MphR(A)-Ery complex. Our study gives useful insights into the nature of amino acids mutation effect, the mechanism of blocking drug resistance at the atomic level and the characteristics in binding affinity for Ery to double mutant (V66L/V126L) MphR(A), which will contribute to the design of more effective macrolide antibiotics.