Intelligent Cell Profiling and Precision Release: Multimolecular Marker-Activated Transmembrane DNA Computing Nanosystem.

Accurate classification of tumor cells is of importance for cancer diagnosis and further therapy. In this study, we develop multimolecular marker-activated transmembrane DNA computing systems (MTD). Employing the cell membrane as a native gate, the MTD system enables direct signal output following simple spatial events of "transmembrane" and "in-cell target encounter", bypassing the need of multistep signal conversion. The MTD system comprises two intelligent nanorobots capable of independently sensing three molecular markers (MUC1, EpCAM, and miR-21), resulting in comprehensive analysis. Our AND-AND logic-gated system (MTDAND-AND) demonstrates exceptional specificity, allowing targeted release of drug-DNA specifically in MCF-7 cells. Furthermore, the transformed OR-AND logic-gated system (MTDOR-AND) exhibits broader adaptability, facilitating the release of drug-DNA in three positive cancer cell lines (MCF-7, HeLa, and HepG2). Importantly, MTDAND-AND and MTDOR-AND, while possessing distinct personalized therapeutic potential, share the ability of outputting three imaging signals without any intermediate conversion steps. This feature ensures precise classification cross diverse cells (MCF-7, HeLa, HepG2, and MCF-10A), even in mixed populations. This study provides a straightforward yet effective solution to augment the versatility and precision of DNA computing systems, advancing their potential applications in biomedical diagnostic and therapeutic research.

Lack of alternative: Chinese first-time mothers' construction of social support network of online secondary groups.

Background: As a result of rapid modernization and the long-term implementation of One Child Policy, Chinese first-time mothers' primary child-raising social support network is gradually shrinking. At the same time, the social support system for child raising is still very incomplete. Therefore, Chinese first-time mothers generally face great pressure. Objective: This paper aims to understand Chinese first-time mothers' construction of social support network of online secondary groups. Methods: This paper employs a qualitative research method, with semi-structured interviews with 23 participants, two focus groups and observations conducted in nine online child-raising communities. Results: Based on the principle of instrumental rationality first-time mothers use various strategies to join different types of online communities and their online social support network is always the dynamic changing. The online social support network is a supplementary channel in which first-time mothers can obtain both instrumental and emotional support. But communication risks and ethical issues remain, such as information exchange interfered by commercial capital, widespread anxiety and superficial social relationships. Conclusions: Online social support network is an alternative for Chinese first-time mothers and they urgently need a more well-rounded social support network system with government leading and multiple subjects participating in it.

Antioxidant properties of two gallotannins isolated from the leaves of Pistacia weinmannifolia.

Pistacia weinmannifolia J. Poisson ex Franch (Anacardiaceae) is a shrub or arbor widely found in Yunnan province of China and its leaves are used as traditional Chinese medicine by herbalists. The leaves of P. weinmannifolia are rich in phenolic compounds, among which two novel gallotannins, Pistafolin A and Pistafolin B, are identified. In the present investigation, the antioxidant efficiency of Pistafolin A and Pistafolin B in preventing lipid, protein and DNA from reactive oxygen species-mediated damage was studied. Both Pistafolin A and Pistafolin B inhibited the peroxyl-radical induced lipid peroxidation of l-alpha-phosphatidylcholine liposomes dose-dependently and prevented the bovine serum albumin from peroxyl-induced oxidative damage. Pistafolin A and Pistafolin B also inhibited copper (II)-1,10-phenanthroline complex-induced DNA oxidative damage. Both Pistafolin A and Pistafolin B scavenged the hydrophilic 2,2'-azinobis(3-ethylbenzothiozoline-6-sulphonic acid) diammonium salt-free radicals and the hydrophobic 1,1-dipheny-2-picrylhydrazyl radicals effectively, suggesting they may act as hydrogen donating antioxidants. The protective effects of the two gallotannins against oxidative damage of biomacromolecules were due to their strong free radical scavenging ability. Pistafolin A with three galloyl moieties showed stronger antioxidant ability than Pistafolin B with two galloyl moieties.

The antioxidant ESeroS-GS inhibits NO production and prevents oxidative stress in astrocytes.

Within the central nervous system uncontrolled production of large amounts of nitric oxide (NO) by activated glial cells might be the common pathogenesis of several neurodegenerative disorders, including Alzheimer's disease and Parkinson's disease. In the present investigation, we measured the effect of a novel antioxidant gamma-L-glutamyl-S-[2-[[[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-yl]oxy]carbonyl]-3-[[2-(1H-indol-3-yl)ethyl]amino]-3-oxopropyl]-L-cysteinyl-glycine sodium salt (ESeroS-GS) on NO production in cultured rat astrocytes. Upon stimulation with 1 microg/mL lipopolysaccharide plus 100 U/mL interferon-gamma which induced the expression of inducible nitric oxide synthase, cultured astrocytes generated large amounts of NO as measured by nitrite assay and ESR technique. The endogenous NO caused oxidative damage in astrocytes, which was confirmed by the accumulation of both cytosolic and extracellular peroxides, the decrease in the cellular glutathione level, and the formation of thiobarbituric acid reactive substrates. Production of endogenous NO resulted in cell death finally. Pretreatment with the novel antioxidant ESeroS-GS effectively decreased the expression of iNOS gene, inhibited the formation of endogenous NO, and prevented NO-induced oxidative damage and cell death in astrocytes. The results suggest that ESeroS-GS might be used as a potential agent for the prevention and therapy of diseases associated with the overproduction of NO by activated astrocytes.

Iron-induced oxidative damage and apoptosis in cerebellar granule cells: attenuation by tetramethylpyrazine and ferulic acid.

Tetramethylpyrazine and ferulic acid are two active ingredients of a Chinese herbal medicine Ligusticum wallichi Franchat. In the present investigation, iron-induced oxidative neuronal damage and the protective effects of tetramethylpyrazine and ferulic acid against this induction were studied in primary cultures of rat cerebellar granule cells. When neurons were treated with 200 microM of FeSO(4) for 1 h, lipid peroxidation in neurons increased time dependently, as measured with the thiobarbituric acid assay. Thirty-six hours after iron treatment, the cell viability decreased to 43.6% and the percentage of apoptotic cells increased to 50.6%. Transmission electron microscopic examination showed a disrupted nuclear envelope and condensed chromatin in iron-treated neurons. Analysis of DNA extracted from iron-treated cells by agarose gel electrophoresis showed the typical "ladder pattern", which indicated the formation of mono- and oligonucleosomes. After iron treatment, caspase 3 activity increased significantly, as measured in a fluoregenic assay. The results above suggested that iron treatment triggered oxidative stress and apoptosis in neurons. Western blot revealed that iron treatment up-regulated the apoptosis-related gene p53 as well as its effector gene p21(waf1/cip1). Pretreatment of the cells with 100 microM of tetramethylpyrazine or ferulic acid effectively decreased the activation of caspase 3 as well as the expression of p53 and p21(waf1/cip1), and attenuated iron-induced oxidative damage and apoptosis. The results suggest that tetramethylpyrazine and ferulic acid might be used as preventive agents against neuronal diseases associated with oxidative stress.

Tetramethylpyrazine scavenges superoxide anion and decreases nitric oxide production in human polymorphonuclear leukocytes.

Tetramethylpyrazine is one of the active ingredients of the Chinese herb Ligusticum wallichii Franchat. By electron spin resonance spin trapping methods, effects of tetramethylpyrazine on superoxide anion and nitric oxide generated by human polymorphonuclear leukocytes were studied. During the respiratory burst of polymorphonuclear leukocytes induced by N-formylmethionyl-leucyl-phenylalanine, tetramethylpyrazine scavenges superoxide anion dose-dependently, and decreases the production of nitric oxide significantly, but shows no influence on oxygen consumption. These results suggest that the effective protection of tetramethylpyrazine against ischemic brain injury might be due to its scavenging of reactive oxygen species and regulation on nitric oxide production, and consequent prevention of peroxynitrite formation.

Sodium tanshinone IIA sulfonate mediates electron transfer reaction in rat heart mitochondria.

In this paper, an electron transfer reaction mediated by sodium tanshinone IIA sulfonate (STS) was studied in rat heart mitochondria. It was found that STS could stimulate mitochondrial NADH oxidation dose-dependently and partly restore NADH oxidation in the presence of respiratory inhibitor (rotenone or antimycin A or KCN). It was likely that STS could accept electrons from complex I similar to ferricyanide and could be converted to its semiquinone form that could then reduce oxygen molecule. The data also showed that cytochrome c (Cyt c) could be reduced by STS in the presence of KCN, or STS could transfer the electron to oxygen directly. Free radicals were involved in the process. The results suggest that STS may protect ischemia-reperfusion injury through an electron transfer reaction in mitochondria against forming reactive oxygen radicals.

Nitric oxide and oxygen radicals induced apoptosis via bcl-2 and p53 pathway in hypoxia-reoxygenated cardiomyocytes.

Neonatal rat cardiomyocytes were subjected to 24 h of hypoxia 95%N2/5%CO2 and 24 h of hypoxia plus 4 h of reoxygenation 95%O2/5%CO2. 24 h of hypoxia increased the levels of NO, NO2-/NO3-, TBARS and LDH. 24 h of hypoxia plus 4 h of reoxygenation decreased the levels of NO, NO2-/NO3-, but further increased TBARS and LDH. The hypoxia up-regulated the expression of bcl-2, p53 and p21/waf1/cip1 but the reoxygenation down-regulated the expression of bcl-2, and further up-regulated p53 and p21/waf1/cip1. The hypoxia increased cell apoptosis and reoxygenation further increased both apoptotic and necrotic cell death. NO, NO2-/NO3- TBARS, DNA fragmentation and cell apoptosis were enhanced by SNP and inhibited by L-NAME respectively. In addition, SOD/catalase down-regulated the expression of p53, p21/wafl/cipl and TBARS but up-regulated bcl-2 and increased indirectly the level of NO, NO2-/NO3-, and inhibited DNA fragmentation. The results suggest that hypoxia-induced cell death is associated with the activation of NO, bcl-2 and p53 pathway, while hypoxia-reoxygenation induced cell death via the generation of reactive oxygen species and activation of p53 pathway. The present study clarified that NO may be an initiative signal to apoptotic cell death and the activation of bcl-2, p53 and p21/waf1/cip1 pathway in hypoxic and hypoxia-reoxygenated cardiomyocytes.

Scavenging of reactive oxygen species and prevention of oxidative neuronal cell damage by a novel gallotannin, pistafolia A.

Pistafolia A is a novel gallotannin isolated from the leaf extract of Pistacia weinmannifolia. In the present investigation, the ability of Pistafolia A to scavenge reactive oxygen species including hydroxyl radicals and superoxide anion was measured by ESR spin trapping technique. The inhibition effect on iron-induced lipid peroxidaiton in liposomes was studied. The protective effects of Pistafolia A against oxidative neuronal cell damage and apoptosis induced by peroxynitrite were also assessed. The results showed that Pistafolia A could scavenge both hydroxyl radicals and superoxide anion dose-dependently and inhibit lipid peroxidation effectively. In cerebellar granule cells pretreated with Pistafolia A, peroxynitrite-induced oxidative neuronal damage and apoptosis were prevented markedly. The antioxidant capacity of Pistafolia A was much more potent then that of the water-soluble analog of vitamin E, Trolox. The results suggested that Pistafolia A might be used as an effective natural antioxidant for the prevention and cure of neuronal diseases associated with the production of peroxynitrite and related reactive oxygen species.

EPC-K1 Prevents ONOO(-)-induced Apoptosis in Cerebellar Granule Neurons.

The cytotoxic effect of peroxynitrite on cerebellar granule neurons was studied. Exposure of cerebellar granule neurons to 10 &mgr;mol/L peroxynitrite triggered apoptosis in vitro, which was confirmed by both morphological (nuclear morphology observed by fluorescence microscopy) and biochemical evidence (DNA fragmentation detected by ELISA). Using ESR spin labeling technique, the alteration of biophysical characteristics of neuronal cell membrane during the apoptotic process was studied. The results indicate that after treatment with peroxynitrite, the fluidity of both the surface layer and the deep layer of the neuronal cell membrane decreased markedly, and the S/W ratio of the membrane protein thiol groups increased significantly. Pre-treating cerebellar granule neurons with antioxidant EPC-K1, a novel water-soluble derivative of vitamin C and vitamin E, alleviated the oxidative injury and prevented cells from apoptosis.