Leptin activates the JAK/STAT pathway to promote angiogenesis in RF/6A cells in vitro.

AIM: To investigate the effect of leptin on the angiogenesis of RF/6A cells (monkey retinal choroidal endothelial cells) in vitro and test the cellular signaling in the mechanism. METHODS: RF/6A cells were cultured in vitro and randomly divided into four groups: normal control, with leptin at 50, 100, 200 ng/mL for cell counting kit-8 (CCK8). RF/6A cell proliferation and migration were examined by Transwell assays, while RF/6A cell tube formation by Matrigel assay. JAK2, p-JAK2, STAT3, and p-STAT3 protein expression was measured by Western blotting. Cells were then divided into the following treatment groups: control, 100 ng/mL leptin and AG-490 (100 ng/mL leptin+10 µmol/L AG-490) for examinations of RF/6A cellular behaviour again. Analysis of differences was carried out using one-way ANOVA and least significant difference (LSD). RESULTS: RF/6A cell proliferation, migration and cell tube formation were promoted significantly by leptin in a dose-dependent manner (P<0.05). Western blotting showed that leptin up-regulated p-JAK2 and p-STAT3 expression levels. Treatment with the JAK/STAT pathway inhibitor, AG-490, decreased leptin-induced p-JAK2 and p-STAT3 expression, and inhibited cell proliferation, migration and cell tube formation induced by leptin (P<0.05). CONCLUSION: Leptin can promote RF/6A cell angiogenesis in vitro via activation of the JAK2/STAT3 signaling pathway.

Band Tunable Microcavity Perovskite Artificial Human Photoreceptors.

Electronic device versions of the neural functions of the human retina have high potential for use in artificial vision. This study demonstrates halide perovskite artificial human photoreceptors with specific photoresponses to red, green, and blue colors, which are consistent with human retinal photoreceiving cones and rods. In contrast to the current programmable spectral-response technologies, a novel microcavity structure is combined in this study with a perovskite absorber to achieve a targeted spectrum without using external optical filters. The fabricated artificial photoreceptors exhibit excellent performance including a high detectivity of more than 1013 Jones, a large linear dynamic range of 154 dB, and a short response time of 580 ns. These values are equal to or better than those of the natural human retina. These devices can easily be monolithically integrated on a single flexible substrate by using vacuum deposition, and a true proof-of-concept full-color image reconstruction is demonstrated.

Prediction of protein-protein interactions by label propagation with protein evolutionary and chemical information derived from heterogeneous network.

Prediction of protein-protein interactions (PPIs) is of great significance. To achieve this, we propose a novel computational method for PPIs prediction based on a similarity network fusion (SNF) model for integrating the physical and chemical properties of proteins. Specifically, the physical and chemical properties of protein are the protein amino acid mutation rate and its hydrophobicity, respectively. The amino acid mutation rate is extracted using a BLOSUM62 matrix, which puts the protein sequence into block substitution matrix. The SNF model is exploited to fuse protein physical and chemical features of multiple data by iteratively updating each original network. Finally, the complementary features from the fused network are fed into a label propagation algorithm (LPA) for PPIs prediction. The experimental results show that the proposed method achieves promising performance and outperforms the traditional methods for the public dataset of H. pylori, Human, and Yeast. In addition, our proposed method achieves average accuracy of 76.65%, 81.98%, 84.56%, 84.01% and 84.38% on E. coli, C. elegans, H. sapien, H. pylori and M. musculus datasets, respectively. Comparison results demonstrate that the proposed method is very promising and provides a cost-effective alternative for predicting PPIs. The source code and all datasets are available at http://pan.baidu.com/s/1dF7rp7N.

[PEGylation of polyamidoamine dendrimer and the properties for gene vectors].

Polyamidoamine-polyethylene glycol (PAMAM-PEG) copolymers were synthesized using IPDI as coupling reagent by two-step method. The copolymers were characterized by IR spectrum and 1H NMR spectrum, and the PEG conjugating ratios of the copolymers were calculated equal to 10% and 30% separately. MTT assay indicated that after PEGylation a lower cytotoxicity of the copolymers could be found, and with increasing PEG conjugating ratio the cytotoxicity decreased obviously. Agarose gel retardation assay demonstrated that PAMAM-PEG copolymers could be combined with DNA and PAMAM-PEG/DNA complexes were prepared by self-assembly. DLS measurement showed that when N/P > or = 50, the particle size of copolymer/ gene complexes was in a range of 150-200 nm, and the zeta potential was in a range of 10-25 mV. In vitro gene transfection illustrated that when N/P < or = 50, the gene transfection efficiency of PAMAM-PEG copolymers was a little less than that of PAMAM-G5, but the transfection efficiency can be raised by increasing N/P ratio or transfection time. Considering both cytotoxicity and transfection efficiency aspects PAMAM-PEG-13 was more effect than PAMAM-PEG-39 in PEGylation.

[Evaluation of the galactomannan assay for the diagnosis of invasive aspergillosis in patients].

OBJECTIVE: To assess the value of Aspergillus galactomannan (GM) double-direct sandwich enzyme-linked immunosorbent assay (ELISA) in the diagnosis of invasive aspergillosis (IA). METHODS: Forty nine patients were divided into IA group (n = 11), other invasive fungal infection group (n = 20) and Aspergillus colonization group (n = 18). The serum samples of all patients and 6 patients with IA after 7 day treatment were used for GM detection. A double-direct sandwich ELISA was employed to detect GM optical density index (ODI) in the serum samples. Measurement data followed the Gaussian distribution were expressed as x +/- s. Differences among groups were tested using a one factor analysis of variance. The significance of variation before and after therapy was tested with paired t test. P < 0.05 were considered to represent a significant difference. Statistical analyses were performed by SPSS statistical package. RESULTS: The serum GM ODI in IA patients was higher (1.63 +/- 0.29) than that in other IFI patients (0.96 +/- 0.49) and Aspergillus colonization patients (0.83 +/- 0.43) , F = 12.681, P < 0.05. The serum GM ODI of 6 patients with IA before and after treatment were 1.67 +/- 0.24 and 1.62 +/- 0.28 (t = 0.475, P > 0.05), respectively. If the cutoff GM ODI was 1.5, the sensitivity, specificity, positive predictive value and negative predictive value for diagnosis of IA in the patients were 72.7% , 84.2%, 57.1% and 94.1%, respectively. CONCLUSIONS: The serum GM detection has diagnostic value for IA and could distinguish Aspergillus infection from other invasive fungal infections and Aspergillus colonization. A cutoff GM ODI of 1.5 showed the best sensitivity and specificity for IA in the patients.

[The diagnostic value of detecting plasma 1, 3-beta-D-glucan for invasive fungal infections].

OBJECTIVE: To evaluate the diagnostic value of the detection of plasma 1, 3-beta-D-glucan for invasive fungal infections (IFI). METHODS: Plasma of patients with IFI, bacterial pneumonia, and oral pharyngeal fungal colonization, and healthy controls were collected from January 2005 to February 2006 in Nanjing General Hospital of Nanjing Military Command of PLA. G-test was used to measure the concentration of 1, 3-beta-D-glucan in the plasma. RESULTS: The concentration of 1, 3-beta-D-glucan in plasma of patients with IFI [(29.5+/-11.5) ng/L] was significantly higher than that of patients with bacterial pneumonia [(13.1+/-5.2) ng/L], fungal colonization [(12.7+/-5.1) ng/L], and healthy controls [(11.7+/-3.5) ng/L], P<0.01. The concentration of 1, 3-beta-D-glucan in patients with bacterial pneumonia was not different as compared to that of patients with fungal colonization, and healthy controls, P>0.05. The concentration of 1, 3-beta-D-glucan in plasma of patients with invasive aspergillosis and invasive candidiasis were (24.7+/-5.8) ng/L and (33.3+/-11.4) ng/L, respectively, the difference being not significant, P>0.05. The concentration of 1, 3-beta-D-glucan in plasma of a patients with invasive pulmonary Cryptococcus neoformans infection and a patient with histoplasmosis were 13.6 ng/L and 25.7 ng/L, respectively. If 20 ng/L was taken as the cut-off value, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 1, 3-beta-D-glucan were 84%, 91%, 84% and 91% respectively. CONCLUSION: The concentration of 1, 3-beta-D-glucan in plasma of patients with IFI increases markedly, which indicates that the detection of 1, 3-beta-D-glucan in plasma is a useful method to diagnose IFI, but can not be used to differentiate aspergillosis from yeast fungus infection. If Fungitec-G kit is used to detect 1, 3-beta-D-glucan and 20 ng/L is used as the cut-off value, the sensitivity and specificity for IFI are high.

[Evaluation of the galactomannan assay for the diagnosis of invasive aspergillosis in an animal model].

OBJECTIVE: To assess the value of Aspergillus galactomannan (GM) double-direct sandwich enzyme-linked immunosorbent assay (ELISA) in the diagnosis of invasive pulmonary aspergillosis (IPA). METHODS: Ninety adult SD rats were randomly divided into 5 groups, including 4 groups of pulmonary infection by Aspergillus fumigatus (A. fumigatus), Candida albicans, mucor, and Streptococcus pneumoniae, respectively, and a colonization group by A. fumigatus in the pharynx oralis (n = 18 each). For the infection models, suspensions of pathogenic bacteria and fungi were instilled into the lungs of the rats by tracheal intubation. For the colonization model, the suspension of A. fumigatus was applied to the nasal cavity and pharynx oralis of the rats. The animals were sacrificed on days 3, 7, and 12 after inoculation, and blood samples were obtained by cardiac puncture and used for GM detection. The lung tissues were prepared for routine pathology examination, and hexamethylene tetramine silver staining was used to detect the fungi. A double-direct sandwich ELISA was employed to detect GM optical density index in the serum samples. RESULTS: The lung tissues of rats infected with A. fumigatus, Candida albicans, mucor and Streptococcus pneumoniae all showed remarkable inflammatory reactions, and hyphae were observed in rats with fungal infection (including A. fumigatus and mucor), and spores in rats infected with Candida albicans. The lung tissues of the A. fumigatus colonization rats showed no inflammatory reactions. The serum GM optical density index of the groups infected with A. fumigatus, Candida albicans, mucor and Streptococcus pneumoniae, and the A. fumigatus colonization group were 1.69 +/- 0.29, 0.89 +/- 0.46, 0.87 +/- 0.39, 0.77 +/- 0.34 and 0.90 +/- 0.49, respectively. The serum GM optical density index of the IPA group was higher than those of the other 4 groups (P < 0.05). If the cutoff ODI was 1.5, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for diagnosis of IPA in the rats were 78.6%, 87.5%, 57.9% and 94.9%, respectively. The sensitivity for A. fumigatus infection on days 3, 7, and 12 was 60.0%, 80% and 100%, and the specificity was 95.5%, 81.0% and 85.7%, respectively. CONCLUSION: GM detection could distinguish Aspergillus infection from Candida albicans, mucor, Streptococcus pneumoniae infection and Aspergillus colonization. The sensitivity of the test for the diagnosis of IPA tended to be higher with longer duration of infection. A cutoff ODI of 1.5 showed the best sensitivity and specificity for IPA in this rat model.