URNet: System for recommending referrals for community screening of diabetic retinopathy based on deep learning.

Diabetic retinopathy (DR) will cause blindness if the detection and treatment are not carried out in the early stages. To create an effective treatment strategy, the severity of the disease must first be divided into referral-warranted diabetic retinopathy (RWDR) and non-referral diabetic retinopathy (NRDR). However, there are usually no sufficient fundus examinations due to lack of professional service in the communities, particularly in the developing countries. In this study, we introduce UGAN_Resnet_CBAM (URNet; UGAN is a generative adversarial network that uses Unet for feature extraction), a two-stage end-to-end deep learning technique for the automatic detection of diabetic retinopathy. The characteristics of DDR fundus data set were used to design an adaptive image preprocessing module in the first stage. Gradient-weighted Class Activation Mapping (Grad-CAM) and t-distribution and stochastic neighbor embedding (t-SNE) were used as the evaluation indices to analyze the preprocessing results. In the second stage, we enhanced the performance of the Resnet50 network by integrating the convolutional block attention module (CBAM). The outcomes demonstrate that our proposed solution outperformed other current structures, achieving 94.5% and 94.4% precisions, and 96.2% and 91.9% recall for NRDR and RWDR, respectively.

Comprehensive climatic suitability evaluation of peanut in Huang-Huai-Hai region under the background of climate change.

The climate changes influence the growing suitability of peanut, an important oil crop. Climatic suitability evaluation in the Huang-Huai-Hai region, the main peanut producing region of China, which can optimize peanut planting structure and provide basis for increasing output. In this study, the temperature, precipitation, sunshine and comprehensive suitability models were established by using the climatic suitability function in different growth periods of peanut. In this study, the climate suitability function of peanut in different growth periods was used to establish the temperature, precipitation, sunshine and comprehensive suitability model. Combined with the meteorological data after Anusplin interpolation, the spatial distribution and chronological change of peanut climate suitability were analyzed. The results show that with climate change, the overall climate becomes warmer and drier and the temperature and precipitation suitability increase, but the sunshine suitability decreases. Based on the comprehensive suitability model, the suitability evaluation results are divided into four levels: the most suitable, suitable, sub-suitable and unsuitable. Among them, the most suitable peanut planting areas in the Huang-Huai-Hai region are concentrated in the west of the Haihe River Basin and the Huaihe River Basin. The data from the next 30 years show that both the most suitable and suitable areas have been expanded. Through the verification of yield correlation analysis and spatial distribution of disaster frequency, it can be seen that the evaluation results have high accuracy, which can be used to guide and optimize peanut production practices.

Ketorolac Administration After Colorectal Surgery Increases Anastomotic Leak Rate: A Meta-Analysis and Systematic Review.

OBJECTIVE: This meta-analysis aimed to evaluate whether ketorolac administration is associated with an increased anastomotic leak rate after colorectal surgery. METHODS: The literature was searched using the Web of Science, Embase, and PubMed databases, and the search ended on May 31, 2020. The Newcastle-Ottawa Scale was used to assess methodological quality. Statistical heterogeneity was assessed using the Chi-square Q test and I 2 statistics. Subgroup analysis was performed, and Egger's test was used to assess publication bias. RESULTS: This meta-analysis included seven studies with 400,822 patients. Our results demonstrated that ketorolac administration after surgery increases the risk of anastomotic leak [OR = 1.41, 95% CI: 0.81-2.49, Z = 1.21, P = 0.23]. Low heterogeneity was observed across these studies (I 2 = 0%, P = 0.51). The results of subgroup analysis showed that the use of ketorolac in case-control and retrospective cohort studies significantly increased the risk of anastomotic leak (P < 0.05). Furthermore, the subgroup analysis revealed that ketorolac use increased anastomotic leak rate in patients in the United States and Canada, and ketorolac plus morphine use did not increase anastomotic leak rate in Taiwanese patients (P < 0.05). No significant publication bias was observed (P = 0.126). Moreover, the analysis of risk factors related to anastomotic leak rate indicated that the total use of ketorolac did not increase the risk of anastomotic leak similar to the control group (P > 0.05). CONCLUSION: The meta-analysis indicates that the use of ketorolac increases the risk of anastomotic leak after colorectal surgery. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, identifier CRD42020195724.

[Fate of Antibiotic Resistance Genes and Virulence Genes in Enterococci During Anaerobic Digestion Process of Thermal Hydrolyzed Sludge].

Municipal sludge contains large amounts of enterococci, which can harbor antibiotic resistance genes (ARGs) and virulence genes (VGs). ARG- and VG-containing enterococci therefore present potential resistance and virulence and, as a consequence, represent a significant health risk to humans. Therefore, the resistance phenotype of enterococci and the prevalence of ARGs and VGs in the enterococci isolated from the mesophilic (40℃) and thermophilic (55℃) anaerobic digestion of thermal hydrolyzed sludge was investigated. Results showed that the enterococci isolated from thermal hydrolyzed sludge showed significantly higher resistance to azithromycin than that to spiramycin and tetracycline. Thermophilic anaerobic digestion resulted in a greater reduction of enterococci abundance (by two orders of magnitude and one order of magnitude, respectively), and a greater reduction in the antibiotic resistance rates of the enterococci. However, thermophilic digestion can promote the expression of tetracycline resistance genes in the enterococci. Furthermore, both mesophilic and thermophilic digestion can facilitate horizontal genes transfer (HGT) between enterococci, which might result in an increase in the occurrence of double- or multiple-resistance. Mesophilic digestion reduced the prevalence of co-occurring ARGs and VGs in enterococci, while thermophilic digestion had the opposite effect. This research improves understanding of the occurrence and fate of ARGs and VGs in potential pathogens during the treatment of municipal sludge.

Dual-Responsive Molecular Probe for Tumor Targeted Imaging and Photodynamic Therapy.

The precision oncology significantly relies on the development of multifunctional agents to integrate tumor targeting, imaging and therapeutics. In this study, a first small-molecule theranostic probe, RhoSSCy is constructed by conjugating 5'-carboxyrhodamines (Rho) and heptamethine cyanine IR765 (Cy) using a reducible disulfide linker and pH tunable amino-group to realize thiols/pH dual sensing. In vitro experiments verify that RhoSSCy is highly sensitive for quantitative analysis and imaging intracellular pH gradient and biothiols. Furthermore, RhoSSCy shows superb tumor targeted dual-modal imaging via near-infrared fluorescence (NIRF) and photoacoustic (PA). Importantly, RhoSSCy also induces strongly reactive oxygen species for tumor photodynamic therapy (PDT) with robust antitumor activity both in vitro and in vivo. Such versatile small-molecule theranostic probe may be promising for tumor targeted imaging and precision therapy.

Clusterin/Akt Up-Regulation Is Critical for GATA-4 Mediated Cytoprotection of Mesenchymal Stem Cells against Ischemia Injury.

BACKGROUND: Clusterin (Clu) is a stress-responding protein with multiple biological functions. Our preliminary microarray studies show that clusterin was prominently upregulated in mesenchymal stem cells (MSCs) overexpressing GATA-4 (MSCGATA-4). We hypothesized that the upregulation of clusterin is involved in overexpression of GATA-4 mediated cytoprotection. METHODS: MSCs harvested from bone marrow of rats were transduced with GATA-4. The expression of clusterin in MSCs was further confirmed by real-time PCR and western blotting. Simulation of ischemia was achieved by exposure of MSCs to a hypoxic environment. Lactate dehydrogenase (LDH) released from MSCs was served as a biomarker of cell injury and MTs uptake was used to estimate cell viability. Mitochondrial function was evaluated by measuring mitochondrial membrane potential (ΔΨm) and caspase 3/7 activity. RESULTS: (1) Clusterin expression was up-regulated in MSCGATA-4 compared to control MSCs transfected with empty-vector (MSCNull). MSCGATA-4 were tolerant to 72 h hypoxia exposure as shown by reduced LDH release and higher MTs uptake. This protection was abrogated by transfecting Clu-siRNA into MSCGATA-4. (2) Exogenous clusterin significantly decreased LDH release and increased MSC survival in hypoxic environment. Moreover, ΔΨm was maintained and caspase 3/7 activity was reduced by clusterin in a concentration-dependent manner. (3) p-Akt expression in MSCs was upregulated following pre-treatment with clusterin, with no change in total Akt. Moreover, cytoprotection mediated by clusterin was partially abrogated by Akt inhibitor LY294002. CONCLUSIONS: Clusterin/Akt signaling pathway is involved in GATA-4 mediated cytoprotection against hypoxia stress. It is suggested that clusterin may be therapeutically exploited in MSC based therapy for cardiovascular diseases.

Polypeptide micelles with dual pH activatable dyes for sensing cells and cancer imaging.

pH is an important control parameter for maintenance of cell viability and tissue functions. pH monitoring provides valuable information on cell metabolic processes and the living environment. In this study, we prepared dual pH-sensitive, fluorescent dye-loaded polypeptide nanoparticles (DPNs) for ratiometric sensing of pH changes in living cells. DPNs contain two types of dyes: N-(rhodamine B) lactam cystamine (RBLC), an acid activatable fluorescent dye with increased fluorescence in an acidic environment, and fluorescein isothiocyanate (FITC), a base activatable fluorescent dye with enhanced fluorescence in an alkaline environment. Hence, DPNs exhibited a dual response signal with strong red fluorescence and weak green fluorescence under acidic conditions; in contrast, they showed strong green fluorescence and almost no red fluorescence under alkaline and neutral conditions. The favorable inverse pH responses of the two fluorescent dyes resulted in ratiometric pH determination for DPNs with an optimized pH-sensitive range of pH 4.5-7.5. Quantitative analysis of the intracellular pH of intact MCF-7 cells has been successfully demonstrated with our nanosensor. Moreover, single acid activatable fluorescent dye doped polypeptide nanoparticles that only contained RBLC can distinguish tumor tissue from normal tissue by monitoring the acidic extracellular environment.

Cardiomyocyte protection by GATA-4 gene engineered mesenchymal stem cells is partially mediated by translocation of miR-221 in microvesicles.

INTRODUCTION: microRNAs (miRs), a novel class of small non-coding RNAs, are involved in cell proliferation, differentiation, development, and death. In this study, we found that miR-221 translocation by microvesicles (MVs) plays an important role in cardioprotection mediated by GATA-4 overexpressed mesenchymal stem cells (MSC). METHODS AND RESULTS: Adult rat bone marrow MSC and neonatal rat ventricle cardiomyocytes (CM) were harvested as primary cultures. MSC were transduced with GATA-4 (MSC(GATA-4)) using the murine stem cell virus (pMSCV) retroviral expression system. Empty vector transfection was used as a control (MSC(Null)). The expression of miRs was assessed by real-time PCR and localized using in situ hybridization (ISH). MVs collected from MSC cultures were characterized by expression of CD9, CD63, and HSP70, and photographed with electron microscopy. Cardioprotection during hypoxia afforded by conditioned medium (CdM) from MSC cultures was evaluated by lactate dehydrogenase (LDH) release, MTS uptake by CM, and caspase 3/7 activity. Expression of miR-221/222 was significantly higher in MSC than in CM and miR-221 was upregulated in MSC(GATA-4). MSC overexpression of miR-221 significantly enhanced cardioprotection by reducing the expression of p53 upregulated modulator of apoptosis (PUMA). Moreover, expression of PUMA was significantly decreased in CM co-cultured with MSC. MVs derived from MSC expressed high levels of miR-221, and were internalized quickly by CM as documented in images obtained from a Time-Lapse Imaging System. CONCLUSIONS: Our results demonstrate that cardioprotection by MSC(GATA-4) may be regulated in part by a transfer of anti-apoptotic miRs contained within MVs.

A unique class of near-infrared functional fluorescent dyes with carboxylic-acid-modulated fluorescence ON/OFF switching: rational design, synthesis, optical properties, theoretical calculations, and applications for fluorescence imaging in living animals.

Fluorescence imaging is one of the most powerful techniques for monitoring biomolecules in living systems. Fluorescent sensors with absorption and emission in the near-infrared (NIR) region are favorable for biological imaging applications in living animals, as NIR light leads to minimum photodamage, deep tissue penetration, and minimum background autofluorescence interference. Herein, we have introduced a new strategy to design NIR functional dyes with the carboxylic-acid-controlled fluorescence on-off switching mechanism by the spirocyclization. Based on the design strategy, we have developed a series of Changsha (CS1-6) NIR fluorophores, a unique new class of NIR functional fluorescent dyes, bearing excellent photophysical properties including large absorption extinction coefficients, high fluorescence quantum yields, high brightness, good photostability, and sufficient chemical stability. Significantly, the new CS1-6 NIR dyes are superior to the traditional rhodamine dyes with both absorption and emission in the NIR region while retaining the rhodamine-like fluorescence ON-OFF switching mechanism. In addition, we have performed quantum chemical calculations with the B3LYP exchange functional employing 6-31G* basis sets to shed light on the structure-optical properties of the new CS1-6 NIR dyes. Furthermore, using CS2 as a platform, we further constructed the novel NIR fluorescent TURN-ON sensor 7, which is capable of imaging endogenously produced HClO in the living animals, demonstrating the value of our new CS NIR functional fluorescent dyes. We expect that the design strategy may be extended for development of a wide variety of NIR functional dyes with a suitable fluorescence-controlled mechanism for many useful applications in biological studies.

Paracrine effect of Wnt11-overexpressing mesenchymal stem cells on ischemic injury.

Our previous studies have suggested that transduction of Wnt11 directly increases bone marrow-derived mesenchymal stem cells (MSCs) differentiation into cardiac phenotypes. In this study, we investigated whether Wnt11 enhances MSC-mediated cardioprotection via paracrine fashion after acute ischemia. MSCs were harvested from male rat bone marrow and transduced with Wnt11 (MSC(Wnt11)). An acute myocardial infarction model in rats was developed by ligation of the left anterior descending coronary artery. MSC(Wnt11) were transplanted into the peri-infarct region after acute myocardial infarction. To mimic ischemic injury, cultured cardiomyocytes (CMs) isolated from neonatal ventricles were exposed to hypoxia. ELISA studies indicated that the release of Wnt11 (3.45-fold) as well as transforming growth factor-ß2 (TGFß2) (1.5-fold) was significantly increased from MSC(Wnt11) compared with transduced control MSC (MSC(Null)). Hypoxia-induced apoptosis and cell death was significantly reduced when CM were co-cultured with MSC(Wnt11) in a dual chamber system. The cell protection mediated by MSC(Wnt11) was mimicked by treating CM with conditioned medium obtained from MSC(Wnt11) and abrogated by Wnt11- and TGFß2 neutralizing antibodies. Further, animals receiving MSC(Wnt11) showed a significant improvement in cardiac contractile function as assessed by echocardiography. Masson trichrome and TUNEL staining showed a significant reduction in infarct size and apoptosis of CM in MSC(Wnt11)-treated animals. Transplantation of MSC(Wnt11) improved cardiac function. The release of Wnt11 and other factors from transplanted MSC(Wnt11) is more likely responsible for protection of native CM at risk.

Development of an ICT-based ratiometric fluorescent hypochlorite probe suitable for living cell imaging.

We have judiciously constructed a novel ICT-based ratiometric OCl(-) probe capable of ratiometric imaging in the live cells based on the new OCl(-)-promoted de-diaminomaleonitrile reaction.

Rational design of a highly reactive ratiometric fluorescent probe for cyanide.

A novel highly reactive ratiometric fluorescent cyanide probe was judiciously designed based on 2-formylacrylonitrile moiety as a new cyanide reaction site. A DFT study was conducted to rationalize the extremely high reactivity nature of the ratiometric fluorescent cyanide probe.

A ratiometric fluorescent probe for specific detection of cysteine over homocysteine and glutathione based on the drastic distinction in the kinetic profiles.

The first ratiometric fluorescent probe for specific detection of cysteine over homocysteine and glutathione was developed based on the drastic distinction in the kinetic profiles.

A fast-responsive fluorescent probe for detection of gold ions in water and synthetic products.

We have constructed a fast-responsive fluorescent gold ion probe based on the unexpected gold ion-mediated hydrolysis of acylsemicarbazides to carboxylic acids. The probe has been applied for sensing gold ions in the living cells and detecting residual gold content in gold-catalyzed synthetic samples for the first time.

Transduction of Wnt11 promotes mesenchymal stem cell transdifferentiation into cardiac phenotypes.

Transplantation of mesenchymal stem cells (MSCs) has emerged as a potential treatment for ischemic heart repair. Previous studies have suggested that Wnt11 plays a critical role in cardiac specification and morphogenesis. In this study, we examined whether transduction of Wnt11 directly increases MSC differentiation into cardiac phenotypes. MSCs harvested from rat bone marrow were transduced with both Wnt11 and green fluorescent protein (GFP) (MSC(Wnt11)) using the murine stem cell virus (pMSCV) retroviral expression system; control cells were only GFP-transfected (MSC(Null)). Compared with control cells, MSC(Wnt11) was shown to have higher expression of Wnt11 by immunofluorescence, real-time polymerase chain reaction, and western blotting. MSC(Wnt11) shows a higher expression of cardiac-specific genes, including GATA-4, brain natriuretic peptide (BNP), islet-1, and α-actinin, after being cultured with cardiomyocytes (CMs) isolated from ventricles of neonatal (1-3 day) SD rats. Some MSC(Wnt11) were positive for α-actinin when MSCs were cocultured with native CMs for 7 days. Electron microscopy further confirmed the appearance of sarcomeres in MSC(Wnt11). Connexin 43 was found between GFP-positive MSCs and neonatal rat CMs labeled with red fluorescent probe PKH26. The transdifferentiation rate was significantly higher in MSC(Wnt11) than in MSC(Null), as assessed by flow cytometry. Functional studies indicated that the differentiation of MSC(Wnt11) was diminished by knockdown of GATA-4 with GATA-4-siRNA. Transduction of Wnt11 into MSCs increases their differentiation into CMs by upregulating GATA-4.

Paracrine factors released by GATA-4 overexpressed mesenchymal stem cells increase angiogenesis and cell survival.

Transplanted mesenchymal stem cells (MSC) release soluble factors that contribute to cardiac repair and vascular regeneration. We hypothesized that overexpression of GATA-4 enhances the MSC secretome, thereby increasing cell survival and promoting postinfarction cardiac angiogenesis. MSCs harvested from male rat bone marrow were transduced with GATA-4 (MSC(GATA-4)) using the murine stem cell virus retroviral expression system; control cells were either nontransduced (MSC(bas)) or transduced with empty vector (MSC(Null)). Compared with these control cells, MSC(GATA-4) were shown by immunofluorescence, real-time PCR, and Western blotting to have higher expression of GATA-4. An increased expression of angiogenic factors in MSC(GATA-4) and higher MSC resistance against hypoxia were observed. Human umbilical vein endothelial cells (HUVEC) treated with MSC(GATA-4) conditioned medium exhibited increased formation of capillary-like structures and promoted migration, compared with HUVECs treated with MSC(Null) conditioned medium. MSC(GATA-4) were injected into the peri-infarct region in an acute myocardial infarction model in Sprague-Dawley rats developed by ligation of the left anterior descending coronary artery. Survival of MSC(GATA-4), determined by Sry expression, was increased at 4 days postengraftment. MSC(GATA-4)-treated animals showed significantly improved cardiac function as assessed by echocardiography. Furthermore, fluorescent microsphere and histological studies revealed increased blood flow and blood vessel density and reduced infarction size in MSC(GATA-4)-treated animals. We conclude that GATA-4 overexpression in MSCs increased both MSC survival and angiogenic potential in ischemic myocardium and may therefore represent a novel and efficient therapeutic approach for postinfarct remodeling.