Forensic analysis of soman exposure using characteristic fragment ions from protein adducts

The verification of exposure to nerve agents is a serious challenge, especially in cases of soman (GD) poisoning. Protein adducts are reliable biomarkers, that provide forensic information and evidence during incidents of terrorism or sporadic poisoning. Mass spectrometry, coupled with a proteomics approach, was established for the forensic analysis of GD-based protein adducts. The fragmentation pathways of GD-based protein adducts were investigated for the first time using electrospray ionization tandem mass spectrometry. Three abundant natural loss product ions, [M+2H-54]²⁺ (loss of two carbon cations), [M+2H-72]²⁺ (loss of tert-butyl and methyl moieties), and [M+2H-84]²⁺ (loss of the pinacolyl moieties), were observed in each of the GD-labeled adducts, and the product ions were independent of protein structure and exposure route. A unique mechanism for the formation of product ions involving GD-protein adducts is proposed here. These findings support the development of a simple and precise forensic analysis technique to rapidly verify GD poisoning using these three GD-related product ions.

Altered functional connectivity density in primary angle-closure glaucoma patients at resting-state

Background

Primary angle-closure glaucoma (PACG) is a neurodegenerative disease. Previous structural and functional studies of functional magnetic resonance imaging (fMRI) have demonstrated widespread dysfunction of spontaneous activity in the PACG brain. In this study, we applied a data-driven graph theory approach of functional connectivity density (FCD) mapping to investigate the altered local and global functional connectivity (FC) of the cortex in PACG.

Methods

Forty-five PACG patients (53.28±10.79 years, 17 males/28 females) and 46 well-matched healthy controls (HCs) (52.67±11.01 years,18 males/28 females) received resting-state fMRI scans. All PACG patients finished complete ophthalmologic examinations, including retinal nerve fiber layer thickness (RNFLT), intraocular pressure (IOP), average cup to disc ratio (A-C/D), and vertical cup to disc ratio (V-C/D). We calculated the between-group FCD difference for short-range and long-range in each voxel. Then, we generated the intrinsic FC of the seed region with the whole brain. Finally, correlations were investigated between FCD value of the altered regions and clinical variables.

Results

PACG patients showed increased short-range FCD in the left inferior frontal gyrus (IFG)/insula/parahippocampal gyrus and right IFG/insula (P<0.05, corrected), compared with the HCs. Simultaneously, the decreased regions in short-range FCD map were the occipital/cuneus/precuneus/superior parietal/postcentral lobe (P<0.05, corrected). In the PACG groups, decreased long-range FCD was observed in the left middle frontal gyrus compared to the HC (P<0.05, corrected). RNFLT was positively correlated with decreased short-range FCD value of the occipital/cuneus/precuneus/superior parietal/postcentral lobes, and the A-C/D was negatively correlated with the increased short-range FCD value of the left IFG/insula/parahippocampal gyrus, and the right IFG/insula.

Conclusions

Our findings suggest that PACG can induce extensive brain dysfunction, and showed different spatial distribution in short- and long-range FCD.

Erlotinib has tumor inhibitory effect in human retinoblastoma cells

AIM

In this study, we explored the effect of erlotinib on the development of retinoblastoma (RB) cells both in vitro and in vivo.

METHOD

RB cell lines, Y79 and WERI cells were treated with various concentrations of erlotinib in vitro to assess their cytotoxic profiles. In vitro proliferation, cell-cycle transition and migration were compared between RB cells treated with erlotinib and cells without erlotinib treatment. In in vivo tumorigenicity assay, mice were injected with Y79 cells and orally fed with erlotinib for 28days. The effect of erlotinib on in vivo tumor grafts was then assessed. Western blot analysis on EGFR, ERK, AKT proteins and their phosphorylated proteins was also performed to assess molecular signaling pathways of associated with erlotinib in RB cells.

RESULTS

In vitro erlotinib treatment induced cytotoxicity in Y79 and WERI cells in dose-dependent manner. While Y79 and WERI cells were treated with erlotinib close to EC₅₀ concentrations for 3days, RB proliferation, cell-cycle transition and migration were all significantly inhibited. In in vivo tumorigenicity assay, oral induction of erlotinib also dramatically reduced the growth of Y79 tumor grafts. Western blot demonstrated that, in in vitro RB cells, erlotinib did not alter the protein expression levels of EGFR, ERK or AKT, but significantly reduced the expressions of phosphorylated EGFR, ERK and AKT proteins.

CONCLUSION

Erlotinib was shown to have tumor suppressive effect on RB growth in vitro and in vivo, possibly through the inhibition on EGFR, ERG/AKT signaling pathways.

[The expression of transcription factors Snail and Slug in epithelial-mesenchymal transition of human lens epithelial cells induced by transforming growth factor-β2]

OBJECTIVE

To investigate the expression of transcription factors snail and slug in epithelial mesenchymal transition (EMT) of human lens epithelial cells (HLEC) induced by transforming growth factor-β2 (TGF-β2).

METHODS

Experimental research. HLEC were treated with different concentrations of TGF-β2 (1.0 and 10.0 μg/L) for different time. The morphological changes were observed under inverted microscope. The expression and cellular localization of snail and slug were evaluated by immunofluorescence. Expressions of snail, slug, E-Cadherin and α-SMA were further determined by Western blot analysis. Single factor analysis of variance, rank sum test and Pearson correlation were used for statistical analysis.

RESULTS

Cultured HLEC were polygonal monolayer cells with tight intercellular adhesion closely and patchy distribution. After treatment of different doses of TGF-β2 for 24 h, HLEC became isolated, exhibited long spindle-like shape as fibroblastic phenotype. The immunofluorescence staining indicated that snail and slug were localized in the nuclei. The expressions of snail and slug appeared to be positive correlative to TGF-β2 dose (snail protein expression: 0.74±0.16, 1.13±0.03, 1.54±0.18 and slug protein expression: 1.96±0.02, 3.12±0.09, 4.07±0.12 in HLEC treated with 0.1, 1.0 and 10 μg/L TGF-β2 respectively) (χ(2)=9.62,P=0.022;F=241.10,P<0.01). In addition, the expression of α-SMA and E-Cadherin showed the similar form (α-SMA protein expression: 0.87±0.04, 1.42±0.11, 2.17±0.36 and E-Cadherin protein expression: 2.50±0.36, 1.65±0.32, 0.41±0.14 in HLEC treated with 0.1, 1.0 and 10.0 μg/L TGF-β2 respectively) (χ(2)=9.97,P=0.019;F=19.99,P<0.01). All Pearson correlation coefficient were close to 1. The expression of snail and slug in HLEC were also increased with extending duration of TGF-β2 (1.0 μg/L). The expression levels of both proteins were modestly up-regulated at 8 hours, robustly increased at 24 h, reached peak at 48h and began to decline at 72 h (snail protein expression: 0.90±0.13, 1.43±0.14, 1.96±0.27, 1.57±0.16 and slug protein expression: 0.91±0.36, 1.24±0.16, 2.44±0.26, 1.43±0.16 in HLEC treated with 1.0 μg/L TGF-β2 for 8 h, 24 h, 48 h and 72 h respectively) (F=12.49,P=0.001;F=14.03,P<0.01).

CONCLUSION

Transcription factors snail and slug might be time and dose-dependently involved in in-vitro TGF-β2-induced EMT of HLEC. (Chin J Ophthalmol, 2016, 52: 285-290).

Synergistic effect of quercetin and 6-gingerol treatment in streptozotocin induced type 2 diabetic rats and poloxamer P-407 induced hyperlipidemia

Ginger and quercetin have been reported to have significant antidiabetic effects.

The role of high mobility group box 1 (HMGB-1) in the diabetic retinopathy inflammation and apoptosis

Diabetic Retinopathy (DR) is one of the most common complications of the late phase diabetes, and also a common cause of blindness. High mobility group box 1 (HMGB-1) is considered to be an inflammatory mediator in the late phase that promotes inflammation and neovascularization in diabetes. Therefore, this paper discussed the role of HMGB-1 in diabetic retinopathy inflammation and neovascularization. 96 adult SD rats were randomly divided into control and diabetes group. The diabetic rat model was established by intraperitoneal injection of streptomycin (0.1 mol/L). Western blot was applied to determine HMGB-1 and its receptor RAGE and TLR2 protein expression in the serum. TUNEL was used to detect retinal apoptosis. Immunofluorescence was performed to test HMGB1 protein expression in retina. HBGM-1 and RAGE expression in diabetic rat retina was significantly higher than the control (P < 0.05), while TLR2 expression was lower (P < 0.05). TUNEL detection showed that diabetic rat retinal cells presented obviously higher apoptosis rate (P < 0.05). Immunofluorescence test revealed that HMGB1 largely expressed in the diabetic rat retinal cells (P < 0.05). HMGB1 may involve in the pathogenesis of diabetic retinopathy by binding with RAGE receptor to accelerate rat retinal cells apoptosis.

[Biomechanic and biological activity assessment of concavity-convex amniotic membrane]

This paper conducted research on biomechanical characteristics and biological activity of concavity-convex amniotic membrane (CCAM) and discussed its superiority as ocular surface repair material. Folding and compression with vacuum of fresh amniotic membrane were used to prepare CCAM. After cutting the striga of CCAM, sixteen CCAM tissue section were chosen at random to test their tensile strength using electronic universal testing machine. The bilayer amniotic membrane (BAM), the double-deck amniotic membrane (DAM) and the monolayer amniotic membrane (MAM) were as controls. The test parameters included yield strength, tensile strength, elongation at break, elastic modulus and so on. The cytokines of fresh amniotic membrane (FAM), MAM and CCAM were analyzed by radioimmunoassay method. The CCAM was obviously thicker than MAM and DAM. After 15 min in PBS, the CCAM tissue can recover the normal shape. The tensile strength and the elongation at break of CCAM were higher than those of the MAM and the DAM (P < 0.05). The elastic modulus of the CCAM was smaller than that of the MAM and the DAM (P < 0.05). The content of 10 cytokines [epidermal growth factor (EGF), fibroblast growth factor (FGF), b-fibroblast growth factor b-FGF, hepatocyte growth factor (HGF), transforming growth factor-beta (TGF-beta), insulin-like growth factor (IGF), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), nerve growth factor (NGF), brain-derived nellrotrophic factor (BDNF), ciliary neurotrophic factor (CNTF)] of CCAM decreased significantly compared with the FAM and increased significantly compared with MAM and DAM in 6 cytokines (EGF, FGF, HGF, TGF-betap, PDGF, NGF; P < 0.05). The CCAM composites is thinner and has higher cytokine content than MAM, and better biomechanical properties than the MAM and the DAM, showing the superiority as ocular surface repair material.

Neurobehavioral study of prenatal exposure to hyperthermia combined with irradiation in mice

Thirty-two pregnant adult LACA mice were randomly assigned to one of five exposure groups: control, 38 degrees C, 42 degrees C, irradiation, and 42 degrees C + irradiation. Animals were exposed on gestation day 9 to either 38 degrees C waterbath for 5 min, 42 degrees C waterbath for 5 min, treatment with 0.5 Gy of 60Co gamma irradiation, or pretreatment at 42 degrees C waterbath for 5 min following by 0.5 Gy of 60CO gamma irradiation. On postnatal day 7, litters were reduced to a maximum of eight pups per litter, with equal members of male and female offspring whenever possible. A total of 216 pups were observed for the age of acquisition of four physiological landmarks (pinna detachment, incisor eruption, eye opening, testes descent), six developmental reflexes (surface righting, cliff avoidance, auditory startle, air righting, visual placing, hindlimb splaying), and examination of learning and memory function. These studies, at threshold exposure levels to hyperthermia and ionizing radiation, indicate there is no consistent significant additional postnatal effect when pregnant mice are exposed to both of these agents. These studies are important for our understanding of the relative long-range effects of prenatal exposure to hyperthermia and acute dose irradiation early in gestation on neurobehavioral teratogenesis.