Study on Autolytic Mechanism and Self-Healing Properties of Autolytic Clinker Microsphere in Alkaline Environment

In this study, the autolytic clinker microsphere with clinker as core and polyvinyl pyrrolidone (PVP) as coating film was prepared. Pretreatment of clinker with silane coupling agent was firstly processed during the preparation. To investigate the autolytic mechanism, the microstructures of the autolytic clinker microsphere at different curing ages were observed using environmental scanning electron microscopy (ESEM), equipped with an energy dispersive spectrometer (EDS). The autolytic stages were also identified based on the microstructural evolution. The influence of pretreatment degree on autolytic behavior was also studied by measurements of micro-morphology and isothermal calorimetry. Experimental results indicated that the compressive strength recovery of specimens was increased by 15–19% due to the addition of autolytic clinker microspheres. The recovery of compressive strength was also improved with the increase of pH value. The improvements in compressive strength recovery of specimens with microspheres were in the range of 15–19%, 15–31%, 25–36%, and 29–50% with the pH value of 7, 8, 10, and 12, respectively. It was also found that inner damage of cement-based matrix had greater recovery when pre-cracked specimens were cured in alkaline environments.     

Astrocytes in the damaged brain: Molecular and cellular insights into their reactive response and healing potential

Long considered merely a trophic and mechanical support to neurons, astrocytes have progressively taken the center stage as their ability to react to acute and chronic neurodegenerative situations became increasingly clear. Reactive astrogliosis starts when trigger molecules produced at the injury site drive astrocytes to leave their quiescent state and become activated. Distinctive morphological and biochemical features characterize this process (cell hypertrophy, upregulation of intermediate filaments, and increased cell proliferation). Moreover, reactive astrocytes migrate towards the injured area to constitute the glial scar, and release factors mediating the tissue inflammatory response and remodeling after lesion. A novel view of astrogliosis derives from the finding that subsets of reactive astrocytes can recapitulate stem cell/progenitor features after damage, fostering the concept of astroglia as a promising target for reparative therapies. But which biochemical/signaling pathways modulate astrogliosis with respect to both the time after injury and the type of damage? Are reactive astrocytes overall beneficial or detrimental for neuroprotection and tissue regeneration? This debate has been animating this research field for several years now, and an integrated view on the results obtained and the possible future perspectives is needed. With this Commentary article we have attempted to answer the above-mentioned questions by reviewing the current knowledge on the molecular mechanisms controlling and sustaining the reaction of astroglia to injury and its stem cell-like properties. Moreover, the cellular/molecular mechanisms supporting the detrimental or beneficial features of astrogliosis have been scrutinized to gain insights on possible pharmacological approaches to enhance astrocyte neuroprotective activities.     

Anisomycin induces glioma cell death via down-regulation of PP2A catalytic subunit in vitro

Aim:

To examine the effects of anisomycin on glioma cells and the related mechanisms in vitro.

Methods:

The U251 and U87 human glioblastoma cell lines were tested. The growth of the cells was analyzed using a CCK-8 cell viability assay. Apoptosis was detected using a flow cytometry assay. The expression of proteins and phosphorylated kinases was detected using Western blotting.

Results:

Treatment of U251 and U87 cells with anisomycin (0.01–8 μmol/L) inhibited the cell growth in time- and concentration-dependent manners (the IC₅₀ values at 48 h were 0.233±0.021 and 0.192±0.018 μmol/L, respectively). Anisomycin (4 μmol/L) caused 21.5%±2.2% and 25.3%±3.1% of apoptosis proportion, respectively, in U251 and U87 cells. In the two cell lines, anisomycin (4 μmol/L) activated p38 MAPK and JNK, and inactivated ERK1/2. However, neither the p38 MAPK inhibitor SB203580 (10 μmol/L) nor the JNK inhibitor SP600125 (10 μmol/L) prevented anisomycin-induced cell death. On the other hand, anisomycin (4 μmol/L) reduced the level of PP2A/C subunit (catalytic subunit) in a time-dependent manner in the two cell lines. Treatment of the two cell lines with the PP2A inhibitor okadaic acid (100 nmol/L) caused marked cell death.

Conclusion:

Anisomycin induces glioma cell death via down-regulation of PP2A catalytic subunit. The regulation of PP2A/C exression by anisomycin provides a clue to further study on its role in glioma therapy.     

Emerging Roles of Human Prostatic Acid Phosphatase

Prostate cancer is one of the most prevalent non-skin related cancers. It is the second leading cause of cancer deaths among males in most Western countries. If prostate cancer is diagnosed in its early stages, there is a higher probability that it will be completely cured. Prostatic acid phosphatase (PAP) is a non-specific phosphomonoesterase synthesized in prostate epithelial cells and its level proportionally increases with prostate cancer progression. PAP was the biochemical diagnostic mainstay for prostate cancer until the introduction of prostate-specific antigen (PSA) which improved the detection of early-stage prostate cancer and largely displaced PAP. Recently, however, there is a renewed interest in PAP because of its usefulness in prognosticating intermediate to high-risk prostate cancers and its success in the immunotherapy of prostate cancer. Although PAP is believed to be a key regulator of prostate cell growth, its exact role in normal prostate as well as detailed molecular mechanism of PAP regulation is still unclear. Here, many different aspects of PAP in prostate cancer are revisited and its emerging roles in other environment are discussed.     

Glycosmis arborea extract as a hepatoprotective agent

Glycosmis arborea is a plant possessing various medicinal properties. The aim of the present study was to investigate the hepatoprotective efficacy of the butanol extract obtained from the aerial parts of the plant. The test sample was prepared by extracting the material through different steps. The extract thus obtained was dissolved in normal saline. Albino rats were prophylactically treated with the extract (i.p.) for 3 weeks. At the end of 3rd week all the groups were injected with hepatotoxic agents. After 48 h of injection, blood was collected and livers were taken out. Different enzymes in the serum were assayed and histopathological study was performed with liver. Glycosmis arborea extract was able to overcome the toxic effects of hepatotoxic agents in terms of lowering the levels of serum GPT, alkaline phosphatase and increased level of SOD in serum. TBARS generation in liver was also altered. Moreover, necrosis of liver produced by carbon tetrachloride was reversed by the extract.     

BERH-2肝癌大鼠红细胞膜K~+依赖性磷酸酶的活性

BERH-2肝癌大鼠红细胞膜K~+依赖性磷酸酶活性与正常大鼠无显著差异。但是,K~+对酶的变构激活及F~-对酶的变构抑制却差别显著,其Hill系数不同于正常大鼠。此差别在0.10mg/ml Triton X-100存在时消失,因此,Hill系数的差异可能由于BERH-2肝癌大鼠红细胞膜中脂质成分与正常的不同所致。     

Studies of Selective Recovery of Zinc and Manganese from Alkaline Batteries Scrap by Leaching and Precipitation

Recovery of zinc and manganese from scrapped alkaline batteries were carried out in the following way: leaching in H₂SO₄ and selective precipitation of zinc and manganese by alkalization/neutralization. As a result of non-selective leaching, 95.6–99.7% Zn was leached and 83.7–99.3% Mn was leached. A critical technological parameter is the liquid/solid treatment (l/s) ratio, which should be at least 20 mL∙g⁻¹. Selective leaching, which allows the leaching of zinc only, takes place with a leaching yield of 84.8–98.5% Zn, with minimal manganese co-leaching, 0.7–12.3%. The optimal H₂SO₄ concentration is 0.25 mol∙L⁻¹. Precipitation of zinc and manganese from the solution after non-selective leaching, with the use of NaOH at pH = 13, and then with H₂SO₄ to pH = 9, turned out to be ineffective: the manganese concentrate contained 19.9 wt.% Zn and zinc concentrate, and 21.46 wt.% Mn. Better selectivity results were obtained if zinc was precipitated from the solution after selective leaching: at pH = 6.5, 90% of Zn precipitated, and only 2% manganese. Moreover, the obtained concentrate contained over 90% of ZnO. The precipitation of zinc with sodium phosphate and sodium carbonate is non-selective, despite its relatively high efficiency: up to 93.70% of Zn and 4.48–93.18% of Mn and up to 95.22% of Zn and 19.55–99.71% Mn, respectively for Na₃PO₄ and Na₂CO₃. Recovered zinc and manganese compounds could have commercial values with suitable refining processes.     

Extraction of Alkalis from Silicate Materials Part 1—Amorphous Silicate Materials

The main building materials widely used worldwide are those based on cement, glass, and ceramics. Taking into account the fact that the raw material base for the production of these materials is narrowing, and the quality of raw materials is declining, methods are being used to modify the structure of silicate materials in order to improve their properties when using cheaper raw materials and industrial waste, which should help reduce the energy intensity of their production. One of the ways to reduce energy consumption is the use of alkaline components in the chemical composition of silicate materials, which makes it possible to reduce the temperature of their synthesis. However, the presence of alkalis in the material at the stage of the operation is undesirable since it contributes, for example, to a decrease in the chemical resistance of silicate glasses or leads to the phenomenon of alkaline corrosion in cement products. In this regard, in order to reduce the negative impact of alkalis, it is necessary to extract them from the surface layers of the silicate material. There are various methods for extracting alkalis from silicate materials, some of which are presented in this article.