An activatable azophenyl fluorescent probe for hypoxic fluorescence imaging in living cells.

Cellular hypoxia is a common pathological process in various diseases. Detecting cellular hypoxia is of great scientific significance for early diagnosis of tumors. The hypoxia fluorescence probe analysis method can efficiently and conveniently evaluate the hypoxia status in tumor cells. These probes are covalently linked by hypoxic recognition groups and organic fluorescent molecules. Currently, the fluorescent molecules used in these probes often exhibit the aggregation-caused quenching effect, which is not conducive to fluorescence imaging in water. Herein, an activatable hypoxia fluorescence probe was constructed by covalently linking aggregation-induced emission luminogens to the hypoxic recognition group azobenzene. It does not emit fluorescence in solution and in solid state under light excitation due to the presence of photosensitive azo bonds. It can be cleaved by intracellular azoreductase into fluorescent amino derivatives with aggregation-induced emission characteristic. As the concentration of oxygen in cells decreases, its fluorescence intensity increases, making it suitable for fluorescence imaging to detect hypoxic environment in live cancer cells. This work broadens the molecular design approach for activatable hypoxia fluorescent probes.

Hypoxia-Responsive Photosensitizer Targeting Dual Organelles for Photodynamic Therapy of Tumors.

Developing safe and precise image-guided photodynamic therapy is a challenge. In this study, the hypoxic properties of solid tumors are exploited to construct a hypoxia-responsive photosensitizer, TPA-Azo. Introducing the azo group into the photosensitizer TPA-BN with aggregation-induced emission quenches its fluorescence. When the nonfluorescent TPA-Azo enters hypoxic tumors, it is reduced by the overexpressed azoreductase to generate a fluorescent photosensitizer TPA-BN with an amino group that exhibits fluorescence-activatable image-guided photodynamic therapy with dual-organelle (lipid droplets and lysosomes) targeting. This design strategy provides a basis for the development of fluorescence-activatable photosensitizers.

Ketamine contributes to the alteration of Ca2+ transient evoked by behavioral tests in the prelimbic area of mPFC: A study on chronic CORT-induced depressive mice.

Recent studies have showed that ketamine is a rapid and efficient antidepressant, but the mechanism of its antidepressant effect is not fully clear. It is still lack of the research investigating the relation between depressive-like behaviors and neuronal activities in specific brain area after administration of ketamine in vivo. Medial prefrontal cortex (mPFC) involved in the pathogenesis of depression. As a result of effective assessments after behavioral test, most studies lack of direct evidence of the relation between efficacy and the activity of specific brain area. Therefore, we used fiber photometry to explore the alteration of Ca2+ transient in the prelimbic (PrL) area of mPFC during behavioral tests in freely moving mice. Our results showed that the chronic corticosterone (CORT) protocol induced depressive-like behaviors. Administration of ketamine reversed these effects. The activation of Ca2+ transients was associated with some behaviors during behavioral tests. Struggling, rearing and exploring evoked strong Ca2+ transients, but moving and grooming did not. The Ca2+ transients amplitude reductions of struggling, rearing and exploring induced by CORT were reversed by ketamine. The results indicated that ketamine ameliorated depressive-like behaviors via mediating neural activation in PrL.

Heterologous prime-boost: an important candidate immunization strategy against Tembusu virus.

BACKGROUND: Tembusu virus (TMUV), a newly emerging pathogenic flavivirus, spreads rapidly between ducks, causing massive economic losses in the Chinese duck industry. Vaccination is the most effective method to prevent TMUV. Therefore, it is urgent to look for an effective vaccine strategy against TMUV. Heterologous prime-boost regimens priming with vaccines and boosting with recombinant adenovirus vaccines have been proven to be successful strategies for protecting against viruses in experimental animal models. METHODS: In this study, heterologous and homologous prime-boost strategies using an attenuated salmonella vaccine and a recombinant adenovirus vaccine expressing prM-E or the E gene of TMUV were evaluated to protect ducks against TMUV infection for the first time, including priming and boosting with the attenuated salmonella vaccine, priming and boosting with the recombinant adenovirus vaccine, and priming with the attenuated salmonella vaccine and boosting with the recombinant adenovirus vaccine. Humoral and cellular immune responses were detected and evaluated. We then challenged the ducks with TMUV at 12 days after boosting to assay for clinical symptoms, mortality, viral loads and histopathological lesions after these different strategies. RESULTS: Compared with the homologous prime-boost strategies, the heterologous prime-boost regimen produced higher levels of neutralizing antibodies and IgG antibodies against TMUV. Additionally, it could induce higher levels of IFN-γ than homologous prime-boost strategies in the later stage. Interestingly, the heterologous prime-boost strategy induced higher levels of IL-4 in the early stage, but the IL-4 levels gradually decreased and were even lower than those induced by the homologous prime-boost strategy in the later stage. Moreover, the heterologous prime-boost strategy could efficiently protect ducks, with low viral titres, no clinical symptoms and histopathological lesions in this experiment after challenge with TMUV, while slight clinical symptoms and histopathological lesions were observed with the homologous prime-boost strategies. CONCLUSIONS: Our results indicated that the heterologous prime-boost strategy induced higher levels of humoral and cellular immune responses and better protection against TMUV infection in ducks than the homologous prime-boost strategies, suggesting that the heterologous prime-boost strategy is an important candidate for the design of a novel vaccine strategy against TMUV.

Carbon Dots Doped with N and S towards Controlling Emitting.

N-doped carbon dots (N-Cdots) were prepared via a solvothermal process in different solvents including water, acetone, and N,N-dimethylformamide (DMF). The red-shifted photoluminescence (PL) peaks and prolonged lifetimes were observed in the three excitation-independent samples. Considering that the similar size distribution, these variations of PL properties were mainly attributed to surface states of Cdots. The crucial effect of acetone and DMF as aprotic solvents were proposed because they can not provided hydrogen during the whole reaction process like H2O, and thus the dehydration reaction was accelerated. Much more N elements were introduced into N-Cdots. Except for N-doping, similar reaction were conducted when N and S were introduced into Cdots at the same time. Similar PL behaviour of N,S-co-doped carbon dots (N,S-Cdots) further confirmed above assumption. This work provided a simple method to control the PL behaviour of Cdots, which will have a promising future in the application of bioimaging and other fields.

Self-Assembly and Stability of Aqueous CdTe Quantum Dots in Buffer Components.

The stability of quantum dots (QDs) in phosphate buffered saline (PBS) solutions plays an important role in the bio-applications. Red-emitting CdTe QDs with high PL efficiency were prepared using thiogliycolic acid as a capping agent. The assembly of the QDs in various buffer components was investigated. Using buffer components such as NaCl, KCl, and phosphate salts as scaffolds, the assembly of CdTe QDs occurred on a slide glass in the re-crystalline process of buffer components. The QDs were homogeneously assembled into the composites with leaf or flake shapes. The result is utilizable for pattern manufacture in applications and domain growth was developed to test the change of photoluminescence (PL) properties and self-assembly of the QDs to form fractal structures. Compared with initial CdTe QD solutions, the PL spectrum of the QDs in the composite is narrowed. The stability test indicated that H2PO-4 and HPO2-4 ions play important roles to decrease the PL of the QDs in PBS buffer solvents.

The Role of HINT1 in Methamphetamine-Induced Conditioned Place Preference.

Drug addiction is a chronically relapsing disorder in humans; yet, the underlying mechanism remained unclear. Recent studies suggested that the histidine triad nucleotide binding protein 1 (HINT1) may play significant roles in diverse neuropsychiatric diseases including drug addiction. In our present study, we used different batches of mice to establish the different stages of methamphetamine (METH)-induced conditioned place preference (CPP) to explore the dynamic changes throughout the process of addiction in different brain regions, including prefrontal cortex (PFC), nucleus accumbens (NAc), corpus striatum (CPu), and hippocampus (Hip). We found that in NAc of the METH group mice, the HINT1 expression level initially increased after acquisition phases, and then dropped to the normal level after extinction phase, and again increased after reinstatement phase. However, there was no statistical difference in the HINT1 expression level in other three encephalic regions (PFC, CPu, and Hip). Therefore, the HINT1 protein, particularly in the NAc, plays a vital role in the METH-induced CPP. However, the precise mechanisms will require further investigation.

[Informed consent right of the appraised individuals in forensic clinical examination].

Informed consent right is not just for basic ethical consideration, but is important for protecting patient's right by law, which is expressed through informed consent contract. The appraised individuals of forensic clinical examination have the similar legal status as the patients in medical system. However, the law does not require informed consent right for the appraised individuals. I recommend giving certain informed consent right to the appraised individuals in the forensic clinical examination. Under the contracted relationship with the institution, the appraised individuals could participate in the examination process, know the necessary information, and make a selected consent on the examination results, which can assure the justice and fairness of judicial examination procedure.

The dopamine D3 receptor regulates the effects of methamphetamine on LPS-induced cytokine production in murine mast cells.

Previous studies have demonstrated that methamphetamine (METH) alter inflammatory and anti-inflammatory cytokine production in the periphery. However, the effect of METH on lipopolysaccharide (LPS)-induced immune responses and its underlying mechanism of action remains unclear. The dopamine D3 receptor (D3R) plays an important role in METH addiction, indicating that the D3R may regulate METH-mediated immune responses. In this study, we examined the effect of METH on mast cell released cytokines in the lungs and thymi of mice stimulated by LPS, and on LPS-induced murine bone marrow-derived mast cells (BMMCs). Moreover, we used D3R-deficient mice to investigate the effect of this receptor on LPS-stimulated mast cell released cytokine production after METH treatment in the lungs and thymi. The effects of a D3R agonist and antagonist on LPS-induced cytokine production after METH treatment in murine BMMCs were also evaluated. METH suppressed LPS-induced cytokine production in the lungs and thymi of wild-type (WT) mice and BMMCs. However, METH did not alter LPS-induced cytokine production in the lungs and thymi of D3R-deficient mice. When BMMCs were treated with the D3R receptor antagonist, NGB2904 hydrochloride (NGB-2904), METH did not alter LPS-induced cytokine production. However, treatment with the D3R agonist, 7-hydroxy-(di-n-propylamino) tetralin (7-OH-DPAT), significantly enhanced the effects of METH on LPS-induced cytokine production. Our results suggest that METH regulates mast cell released cytokines production in an LPS-induced mouse model via the D3R.

Age estimation in northern Chinese children by measurement of open apices in tooth roots.

The aim of this study was to assess the accuracy of Cameriere's methods on dental age estimation in the northern Chinese population. A sample of orthopantomographs of 785 healthy children (397 girls and 388 boys) aged between 5 and 15 years was collected. The seven left permanent mandibular teeth were evaluated with Cameriere's method. The sample was split into a training set to develop a Chinese-specific prediction formula and a test set to validate this novel developed formula. Following the training dataset study, the variables gender (g), x 3 (canine teeth), x 4 (first premolar), x 7 (second molar), N 0, and the first-order interaction between s and N 0 contributed significantly to the fit, yielding the following linear regression formula: Age = 10.202 + 0.826 g - 4.068x 3 - 1.536x 4 - 1.959x 7 + 0.536 N 0 - 0.219 s [Symbol: see text] N 0, where g is a variable, 1 for boys and 0 for girls. The equation explained 91.2 % (R (2) = 0.912) of the total deviance. By analyzing the test dataset, the accuracy of the European formula and Chinese formula was determined by the difference between the estimated dental age (DA) and chronological age (CA). The European formula verified on the collected Chinese children underestimated chronological age with a mean difference of around -0.23 year, while the Chinese formula underestimated the chronological age with a mean difference of -0.04 year. Significant differences in mean differences in years (DA - CA) and absolute difference (AD) between the Chinese-specific prediction formula and Cameriere's European formula were observed. In conclusion, a Chinese-specific prediction formula based on a large Chinese reference sample could ameliorate the age prediction accuracy in the age group of children.

PE­induced apoptosis in SMMC­7721 cells: involvement of Erk and Stat signalling pathways.

Emerging evidence indicates that the redistribution of phosphatidylethanolamine (PE) across the bilayer of the plasma membrane is an important molecular marker for apoptosis. However, the effect of PE on apoptosis and the underlying mechanism of PE remain unclear. In the current study, MTT and flow cytometric assays were used to examine the effects of PE on apoptosis in SMMC­7721 cells. The level of mitochondrial membrane potential (ΔΨm) and the expression of Bax, Bcl­2, caspase­3, phospho­Erk and phospho­Stat1/2 in SMMC­7721 cells that were exposed to PE were also investigated. The results showed that PE inhibited proliferation, caused G0/G1 phase cell cycle arrest and induced apoptosis in SMMC­7721 cells in a dose­dependent manner. Rhodamine 123 staining showed that the treatment of SMMC­7721 cells with different concentrations of PE for 24 h significantly decreased the level of ΔΨm and exerted dose­dependent effects. Using immunofluorescence and western blotting, we found that the expression of Bax was upregulated, whereas that of Bcl­2 was downregulated in PE­induced apoptotic cells. In addition, these events were accompanied by an increase in caspase­3 expression in a dose­dependent manner following PE treatment. PE­induced apoptosis was accompanied by a decrease in Erk phospho-rylation and by the activation of Stat1/2 phosphorylation in SMMC­7721 cells. In conclusion, the results suggested that PE­induced apoptosis is involved in upregulating the Bax/Bcl­2 protein ratio and decreasing the ΔΨm. Moreover, the results showed that the Erk and Stat1/2 signalling pathways may be involved in the process of PE­induced apoptosis.