Fabrication of Coffee-ring Nanostructured Membranes for Organic Solvent Nanofiltration.

Organic solvent nanofiltration (OSN) plays important roles in pharmaceutical ingredients purification and solvent recovery. However, the low organic solvent permeance under cross-flow operation of OSN membrane hampers their industrial applications. Herein, we report the construction of coffee-ring structured membrane featuring high OSN permeance. A water-insoluble crystal monomer that dissolved in EtOH/H2O mixed solvent was designed to react with trimesoyl chloride via interfacial polymerization. Owing to the diffusion of EtOH to n-hexane, coffee-ring nanostructure on the support membrane appeared, which served as the template for construction of coffee-ring structured membrane. The optimal nanostructured membrane demonstrated 2.6-fold enhancement in the effective surface area with reduced membrane thickness. Resultantly, the membrane afforded a 2.7-fold enhancement in organic solvent permeance, e.g., ~ 13 LMH/bar for MeOH, without sacrificing the rejection ability. Moreover, due to the rigid monomer structure, the fabricated membrane shows distinctive running stability in active pharmaceutical ingredients purification and the ability for concentration of medicines.

Tailored Polypyrrole Nanofibers as Ion-to-Electron Transduction Membranes for Wearable K+ Sensors.

Conductive polymers are recognized as ideal candidates for the development of noninvasive and wearable sensors for real-time monitoring of potassium ions (K+ ) in sweat to ensure the health of life. However, the low ion-to-electron transduction efficiency and limited active surface area hamper the development of high-performance sensors for low-concentration K+ detection in the sweat. Herein, a wearable K+ sensor is developed by tailoring the nanostructure of polypyrrole (PPy), serving as an ion-to-electron transduction layer, for accurately and stably tracing the K+ fluctuation in human sweat. The PPy nanostructures can be tailored from nanospheres to nanofibers by controlling the supramolecular assembly process during PPy polymerization. Resultantly, the ion-to-electron transduction efficiency (17-fold increase in conductivity) and active surface area (1.3-fold enhancement) are significantly enhanced, accompanied by minimized water layer formation. The optimal PPy nanofibers-based K+ sensor achieved a high sensitivity of 62 mV decade-1 , good selectivity, and solid stability. After being integrated with a temperature sensor, the manufactured wearable sensor realized accurate monitoring of K+ fluctuation in the human sweat.

Micro/Nano-Fabrication of Flexible Poly(3,4-Ethylenedioxythiophene)-Based Conductive Films for High-Performance Microdevices.

With the increasing demands for novel flexible organic electronic devices, conductive polymers are now becoming the rising star for reaching such targets, which has witnessed significant breakthroughs in the fields of thermoelectric devices, solar cells, sensors, and hydrogels during the past decade due to their outstanding conductivity, solution-processing ability, as well as tailorability. However, the commercialization of those devices still lags markedly behind the corresponding research advances, arising from the not high enough performance and limited manufacturing techniques. The conductivity and micro/nano-structure of conductive polymer films are two critical factors for achieving high-performance microdevices. In this review, the state-of-the-art technologies for developing organic devices by using conductive polymers are comprehensively summarized, which will begin with a description of the commonly used synthesis methods and mechanisms for conductive polymers. Next, the current techniques for the fabrication of conductive polymer films will be proffered and discussed. Subsequently, approaches for tailoring the nanostructures and microstructures of conductive polymer films are summarized and discussed. Then, the applications of micro/nano-fabricated conductive films-based devices in various fields are given and the role of the micro/nano-structures on the device performances is highlighted. Finally, the perspectives on future directions in this exciting field are presented.

Acid-Resistance and Self-Repairing Supramolecular Nanoparticle Membranes via Hydrogen-Bonding for Sustainable Molecules Separation.

Functional membranes generally wear out when applying in harsh conditions such as a strong acidic environment. In this work, high acid-resistance, long-lasting, and low-cost functional membranes are prepared from engineered hydrogen-bonding and pH-responsive supramolecular nanoparticle materials. As a proof of concept, the prepared membranes for dehydration of alcohols are utilized. The synthesized membranes have achieved a separation factor of 3000 when changing the feed solution pH from 7 to 1. No previous reports have demonstrated such unprecedentedly high-record separation performance (pervaporation separation index is around 1.1 × 107  g m-2  h-1 ). More importantly, the engineered smart membrane possesses fast self-repairing ability (48 h) that is inherited from the dynamic hydrogen bonds between the hydroxyl groups of polyacrylic acid and carbonyl groups of polyvinylpyrrolidone. To this end, the designed supramolecular materials offer the membrane community a new material type for preparing high acid resistance and long-lasting membranes for harsh environmental cleaning applications.

Graphene oxide membranes with stable porous structure for ultrafast water transport.

The robustness of carbon nanomaterials and their potential for ultrahigh permeability has drawn substantial interest for separation processes. However, graphene oxide membranes (GOms) have demonstrated limited viability due to instabilities in their microstructure that lead to failure under cross-flow conditions and applied hydraulic pressure. Here we present a highly stable and ultrapermeable zeolitic imidazolate framework-8 (ZIF-8)-nanocrystal-hybridized GOm that is prepared by ice templating and subsequent in situ crystallization of ZIF-8 at the nanosheet edges. The selective growth of ZIF-8 in the microporous defects enlarges the interlayer spacings while also imparting mechanical integrity to the laminate framework, thus producing a stable microstructure capable of maintaining a water permeability of 60 l m-2 h-1 bar-1 (30-fold higher than GOm) for 180 h. Furthermore, the mitigation of microporous defects via ZIF-8 growth increased the permselectivity of methyl blue molecules sixfold. Low-field nuclear magnetic resonance was employed to characterize the porous structure of our membranes and confirm the tailored growth of ZIF-8. Our technique for tuning the membrane microstructure opens opportunities for developing next-generation nanofiltration membranes.

Phosphonium Modification Leads to Ultrapermeable Antibacterial Polyamide Composite Membranes with Unreduced Thickness.

Water transport rate in network membranes is inversely correlated to thickness, thus superior permeance is achievable with ultrathin membranes prepared by complicated methods circumventing nanofilm weakness and defects. Conferring ultrahigh permeance to easily prepared thicker membranes remains challenging. Here, a tetrakis(hydroxymethyl) phosphonium chloride (THPC) monomer is discovered that enables straightforward modification of polyamide composite membranes. Water permeance of the modified membrane is ≈6 times improved, give rising to permeability (permeance × thickness) one magnitude higher than state-of-the-art polymer nanofiltration membranes. Meanwhile, the membrane exhibits good rejection (RNa2SO4 = 98%) and antibacterial properties under crossflow conditions. THPC modification not only improves membrane hydrophilicity, but also creates additional angstrom-scale channels in polyamide membranes for unimpeded transport of water. This unique mechanism provides a paradigm shift in facile preparation of ultrapermeable membranes with unreduced thickness for clean water and desalination.

[Preparation of BiOCl-(NH4)3PW12O40 Photocatalyst and a Mechanism for Photocatalytic Degradation of Organic Pollutants].

The separation efficiency of photogenerated electrons and holes is the key to photocatalytic performance. Layered BiOCl is a kind of newly exploited efficient photocatalyst, but its wide-spread practical application is hindered by the rapid recombination of photogenerated electron-hole pairs and low quantum efficiency. In this study, we prepared a composite photocatalyst via a hydrothermal method in which (NH4)3PW12O40 (NH4PTA) is the acceptor of photoelectrons from BiOCl. The photocatalytic performance of variants of BiOCl-NH4PTA was evaluated by the removal efficiency of methyl orange (MO). The experimental results showed that the BiOCl-NH4PTA[n (Bi):n (W)=1:1] had the best photocatalytic activity under the irradiation of sunlight simulated by xenon light. The photocatalytic mechanism was investigated using the reactive species trapping experiments. It was found that MO could be photodegraded by,·OH, and holes over BiOCl. Differently, and·OH were the dominant reactive species for the reactions over the composite photocatalyst. It was proved that NH4PTA was the acceptor of photoelectrons by the XPS on the photocatalyst before and after reaction. The photocurrent test verified the superior photocatalysis of BiOCl-NH4PTA which was attributed to the efficient separation of electron-hole pairs.

[Preparation of ZnTiO3/TiO2 Photocatalyst and Its Mechanism on Photocatalytic Degradation of Organic Pollutants].

TiO2 is a promising photocatalysis for degradation of organic pollutants due to its innocuity. However, its widespread practical application was hindered by the fast combination speed of photogenerated electron-hole pairs and low quantum efficiency. In this study, we prepared ZnTiO3-TiO2 using the Sol-Gel method to get heterojunctions, which exhibit efficient separation of photogenerated electron-hole pairs. The photocatalytic performances of various ZnTiO3-TiO2 were evaluated by the removal efficiency of Methyl orange. The experimental results showed that the ZnTiO3-TiO2(ZnTiO3:TiO2=0.3), which was calcinated under 600℃, had the best photocatalytic activity under ultraviolet light. The photocatalyst was stable under a wide range of pH (2.5-12.5). The photocurrent and ESR analysis verified the superior photocatalysis of ZnTiO3-TiO2, which was attributed to the efficient separation of electron-hole pairs induced by the heterojunctions.

Circulating microRNA-451 as a predictor of resistance to neoadjuvant chemotherapy in breast cancer.

OBJECTIVE: We aimed to explore the potential application of circulating microRNA-451 (miR-451) in serum in predicting the resistance to neoadjuvant chemotherapy (NACT) in breast cancer (BC). METHODS: Eighty-two BC patients who underwent NACT were recruited in our study, including 41 NACT-sensitive patients (NACT-sensitive group) and 41 NACT-resistant patients (NACT-resistant group). Additionally, 60 healthy subjects were selected as normal controls. Epirubicin-resistant MCF-7 BC cell line (MCF-7/EPI) and docetaxel-resistant MCF-7 BC cell line (MCF-7/DOC) were cultured in our study. MTT assay was applied to calculate the survival rates of MCF-7 cells, MCF-7/DOC cells and MCF-7/EPI cells. The expression levels of miR-451 in normal controls, NACT-sensitive group, NACT-resistant group, MCF-7 cells, MCF-7/DOC cells and MCF-7/EPI cells were measured by qRT-PCR method. RESULTS: The proliferation rates of both the MCF-7/DOC and MCF-7/EPI cells were significantly restrained at the drug concentration of 10 ng/ml, 50 ng/ml, 100 ng/ml and 200 ng/ml. However, the proliferation rates of MCF-7/DOC and MCF-7/EPI cells both increased significantly at the drug concentration of 500ng/ml. Furthermore, the IC50 of MCF-7/DOC cells was 23.603 ng/ml and the IC50 of MCF-7/EPI cells was 3.209 ng/ml. The relative expression of miR-451 was significantly lower in both the NACT-resistant group and the NACT-sensitive group than the normal control group. We also found that the relative expression level of miR-451 was significantly lower in the NACT-resistant group than that in the NACT-sensitive group. The expression of miR-451 in the MCF-7/EPI and the MCF-7/DOC cell lines was significantly lower than that in the MCF-7 cell lines. CONCLUSION: We supported the view that the relative expression level of miR-451 was lower in the NACT-resistant BC patients, suggesting the circulating miR-451 may have a functional significance in predicting the resistance to NACT in BC patients. We laid a foundation for further research on the resistance to NACT in BC treatment.

Influence of MiR-451 on Drug Resistances of Paclitaxel-Resistant Breast Cancer Cell Line.

BACKGROUND: This study aimed to investigate the potential influence of microRNA-451 (miR-451) in drug resistances of the Paclitaxel-resistant breast cancer cell line by transfecting miR-451 mimics and miR-451 inhibitors to MCE-7, MCF-7/EPI, and MCF-7/DOC. MATERIAL AND METHODS: Real-time quantitative PCR (qRT-PCR) was performed for detecting whether transfected miR-451 mimics and miR-451 inhibitors could regulate the expression of miR-451 effectively. The apoptosis of the 3 cell lines was measured by applying Annexin V-APC/PI staining. Western blot was used for the detection of the protein expression of Bcl-2 and Caspase 3 after the transfection of miR-451 mimics /inhibitors. Bioinformatics analysis demonstrated that Bcl-2 protein is a potential target gene for miR-451. RESULTS: In comparison to the control group, after transfection with miR-451 mimics, there was a significant increase in miR-451 expression in MCF-7, MCF-7/EPI, and MCF-7/DOC. Cells in the three cell lines had increased apoptosis, Bcl-2 protein expression decreased significantly, and Caspase protein expression increased obviously. After the transfection with miR-451 inhibitors, miR-451 expression was significantly decreased and apoptosis in the 3 cell lines had no significant decrease compared with the control group. CONCLUSIONS: Increased miR-451 expression may negatively regulate Bcl-2 mRNA and protein expression, followed by affecting the protein expression of caspase 3, and accelerate the apoptosis in breast cancer, indicating that miR-451 might influence the drug resistances of the Paclitaxel-resistant breast cancer cell line.

Neoadjuvant chemotherapy of breast cancer with pirarubicin versus epirubicin in combination with cyclophosphamide and docetaxel.

Breast cancers (BC) are treated with surgery, radiotherapy, and chemotherapy. Neoadjuvant chemotherapy (NACT) is an emerging treatment option in many cancers and is given before primary therapy to shrink tumor size. The efficacy of NACT in varied settings of BC, such as inoperable tumors, borderline resectable tumors, and breast-conserving surgery, has been debated extensively in literature, and the results remain unclear and depended on a wide variety of factors such as cancer type, disease extent, and the specific combination of chemotherapy drugs. This study was performed to examine the efficacy, toxicity, and tolerability of pirarubicin (THP) and epirubicin (EPI) in combination with docetaxel and cyclophosphamide in a NACT setting for BC. A total of 48 patients with stage II or III breast cancers were randomly divided into two groups: THP group and EPI group. The patients in THP group received 2-4 cycles of neoadjuvant chemotherapy with DTC regimen (docetaxel, THP, cyclophosphamide), while patients in the EPI group received 2-4 cycles of DEC regimen (docetaxel, EPI, cyclophosphamide) before surgery. The incidence of adverse reactions and the efficacy of the treatment regimen were compared between the two groups. Prognostic evaluation indexes were estimated by Kaplan-Meier survival analysis, including the 5-year disease-free survival (DFS) and overall survival (OS). The overall response rate in THP group was 83.3 %, and the EPI group showed a response rate of 79.2 %, with no statistically significant difference in response rate between the two groups. The incidence of cardiac toxicity, myelosuppression, nausea, and vomiting in the THP group was significantly lower than the EPI group (all P < 0.05). The incidence of hepatic toxicity, alopecia, and diarrhea in the THP group was also lower than the EPI group, but these differences were not statistically significant. The 5-year DFS and OS in THP versus EPI groups were 80 versus 76 % (DFS) and 86 versus 81 % (OS), respectively. Our study found that NACT with DTC regimen and DEC regimen were both very effective in treatment of BC. However, THP-based combination therapy was associated with significantly lower incidence of cardiac toxicity, myelosuppression, nausea, and vomiting.

Efficacy of neo-adjuvant chemotherapy with TEC regimen on breast cancer.

OBJECTIVE: This study aims to investigate the efficacy of neo-adjuvant chemotherapy with TEC regimen (taxotere-epirubicin-cyclophosphamide) in the treatment of breast cancer (BC) patients. METHOD: Total of 118 BC patients were recruited from the Department of Breast Surgery in Shengjing Hospital of China Medical University from January 1, 2010 to December 31, 2012, in this study. The clinical data and serum samples were collected from each patient prior to the study. All patients were given four cycles of TEC chemotherapy before surgery. RESULTS: The overall response rate of TEC regimen in the treatment of BC was 67.8% (80/118), clinical complete response rate was 3.4% (4/118), and clinical partial response rate was 64.4% (76/118). Furthermore, we found that age, tumor size, lymph node metastasis and clinical stages of patients had no statistically significant difference (all P > 0.05). Both negative ER status and negative PR status were statistically related to better response (P = 0.033 and P = 0.024, respectively) when compared with the positive ER status and positive PR status, while such association was not observed between the negative HER-2 status and positive HER-2 status (P > 0.05). In addition, the efficacy of triple-negative breast cancer was significantly better than that of luminal A, luminal B and HER-2+ cancers (all P < 0.05), but there was no significant difference among the HER-2+, luminal A, luminal B groups (all P > 0.05). CONCLUSION: Our study support the view that BC cases under the TEC chemotherapy were related to higher overall response rates; and the chemotherapy with the TEC regimen could be served as an effective therapy in the treatment of BC.

Aberrant promoter methylation of the CHD1 gene may contribute to the pathogenesis of breast cancer: a meta-analysis.

Cadherin-1 (CHD1), as an invasion suppressor gene, could suppress tumor cell invasion and metastasis in various tumors, but reduced CHD1 levels, resulting from epigenetic silencing, are common in poorly differentiated, advanced stage carcinomas. This meta-analysis was performed to evaluate the relationships between promoter methylation of CHD1 and breast cancer. Relevant studies were retrieved from the Web of Science (1945 ~ 2013), the Cochrane Library (Issue 12, 2013), PubMed (1966 ~ 2013), EMBASE (1980 ~ 2013), CINAHL (1982 ~ 2013), and the Chinese Biomedical Database (CBM) (1982 ~ 2013) using a systematic literature search. Results were summarized by meta-analyses, conducted using the STATA software (version 12.0, Stata Corporation, College Station, TX, USA). Odds ratios (ORs) and 95 % confidence intervals (95 % CIs) were calculated. In the present meta-analysis, 9 cohort studies with a total of 425 patients with breast cancer were included. Our meta-analysis results demonstrated that the frequency of CHD1 promoter methylation in cancer tissues was significantly higher than that in normal tissues, adjacent tissues, and benign tissues (cancer tissue vs. normal tissue OR = 30.87, 95 % CI = 16.76 ~ 56.86, P < 0.001; cancer tissue vs. adjacent tissue OR = 23.30, 95 % CI = 12.85 ~ 42.26, P < 0.001; cancer tissue vs. benign tissue OR = 2.94, 95 % CI = 1.60 ~ 5.40, P < 0.001; respectively). Ethnicity-stratified analysis indicated that aberrant CHD1 promoter methylation was strongly correlated with breast cancer among both Asians and Caucasians in the majority of subgroups. Our results suggest that aberrant promoter methylation of the CHD1 gene may have a high frequency in breast cancer tissues. Thus, CHD1 methylation could be correlated with the pathogenesis of breast cancer.

Differential distribution of microRNAs in breast cancer grouped by clinicopathological subtypes.

BACKGROUND: microRNAs (miRNAs) that regulate proliferation, invasion and metastasis are considered to be the principal molecular basis of tumor heterogeneity. Breast cancer is not a homogeneous tissue. Thus, it is very important to perform microarray-based miRNA screening of tumors at different sites. METHODS: Breast tissue samples from the centers and edges of tumors of 30 patients were classified into 5 clinicopathological subtypes. In each group, 6 specimens were examined by microRNA array. All differential miRNAs were analyzed between the edges and centers of the tumors. RESULTS: Seventeen kinds of miRNAs were heterogeneously distributed in the tumors from different clinicopathological subtypes that included 1 kind of miRNA in Luminal A and Luminal B Her2+ subtypes, 4 kinds in Luminal A and Her2 overexpression subtypes, 6 kinds in Luminal B Ki67+ and Luminal B Her2+ subtypes, 2 kinds between Luminal B Ki67+ and triple-negative breast cancer (TNBC) subtypes, 2 kinds between Luminal B Her2+ and TNBC subtypes, and 2 kinds between Luminal B Ki67+, Luminal B Her2+, and TNBC subtypes. Twenty kinds of miRNAs were homogenously distributed in the tumors from different clinicopathological subtypes that included 6 kinds of miRNAs in Luminal B Ki67+ and Luminal B Her2+ subtypes, 1 kind in Luminal B Ki67+ and Her2 overexpression subtypes, 10 kinds between Luminal B Ki67+ and TNBC subtypes, 2 kinds in Luminal B Her2+ and TNBC subtypes, and 1 kind between Luminal B Ki67+, Luminal B Her2+, and TNBC subtypes. CONCLUSIONS: A total of 37 miRNAs were significantly distributed in tumors from the centers to edges, and in all clinicopathological subtypes.

Effects of differential distribution of microvessel density, possibly regulated by miR-374a, on breast cancer prognosis.

BACKGROUND: The discovery that microRNAs (miRNAs) regulate proliferation, invasion and metastasis provides a principal molecular basis of tumor heterogeneity. Microvessel distribution is an important characteristic of solid tumors, with significant hypoxia occurring in the center of tumors with low blood flow. The distribution of miR-374a in breast tumors was examined as a factor likely to be important in breast cancer progression. METHODS: Breast tissue samples from 40 patients with breast cancer were classified into two groups: a highly invasive and metastatic group (HIMG) and a low-invasive and metastatic Group (LIMG). Samples were collected from the center and edge of each tumor. In each group, six specimens were examined by microRNA array, and the remaining 14 specimens were used for real-time RT-qPCR, Western blot and immunohistochemical analyses. Correlation analysis was performed for the miRNAs and target proteins. Follow-up was carried out during 28 months to 68 months after surgery, and survival data were analyzed. RESULTS: In the LIMG, the relative content of miR-374a was lower in the center of the tumor than at its edge; in the HIMG, it was lower at the edge of the tumor, and miR-374a levels were lower in breast cancer tissues than in normal tissues. There was no difference between VEGF-A and VCAM-1 mRNA levels at the edge and center of the tumor; however, we observed a significant difference between VEGF-A and VCAM-1 protein expression levels in these two regions. There was a negative correlation between miR-374a and target protein levels. The microvessel density (MVD) was lower in the center of the tumor than at its edge in HIMG, but the LIMG vessels were uniformly distributed. There was a significant positive correlation between MVD and the number of lymph node metastases (Pearson correlation, r=0.912, P<0.01). The median follow-up time was 48.5 months. LIMG had higher rate of disease-free survival (100%, P=0.013) and longer median survival time (66 months) than HIMG, which had a lower rate of 75% and shorter median survival time (54 months). CONCLUSIONS: Our data demonstrated miR-374a to be differentially distributed in breast cancer; VEGF-A and VCAM-1 mRNA had coincident distribution, and the distribution of teh respective proteins was uneven and opposite to that for the miR-374a. These data might explain the differences in the distribution of MVD in breast cancer and variation in breast cancer prognosis.

Differential distribution of miR-20a and miR-20b may underly metastatic heterogeneity of breast cancers.

BACKGROUND: The discovery that microRNA (miRNA) regulates metastasis provide a principal molecular basis for tumor heterogeneity. A characteristic of solid tumors is their heterogenous distribution of blood vessels, with significant hypoxia occurring in regions (centers of tumor) of low blood flow. It is necessary to discover the mechanism of breast cancer metastasis in relation to the fact that there is a differential distribution of crucial microRNA in tumors from centers to edges. METHODS: Breast tissues from 48 patients (32 patients with breast cancer) were classified into the high invasive and metastatic group (HIMG), low invasive and metastatic group (LIMG), and normal group. Samples were collected from both the centers and edges of all tumors. The first six specimens were detected by microRNA array, and the second ten specimens were detected by real-time qRT- PCR and Western blot analyses. Correlation analysis was performed between the miRNAs and target proteins. RESULTS: The relative content of miR-20a and miR-20b was lower in the center of the tumor than at the edge in the LIMG, lower at the edge of the tumor than in the center in the HIMG, and lower in breast cancer tissues than in normal tissues. VEGF-A and HIF-1alpha mRNA levels were higher in the HIMG than in the LIMG, and levels were higher in both groups than in the normal group; there was no difference in mRNA levels between the edge and center of the tumor. VEGF-A and HIF-1alpha protein levels were higher in the HIMG than in the LIMG, and protein levels in both groups were higher than in the normal group; there was a significant difference in protein expression between the edge and center of the tumor. Correlation analysis showed that the key miRNAs (miR-20a and miR-20b) negatively correlated with the target proteins (VEGF-A and HIF-1alpha). CONCLUSIONS: Our data suggest that miR-20a and miR-20b are differentially distributed in breast cancer, while VEGF-A and HIF-1alpha mRNA had coincident distributions, and VEGF-A and HIF-1alpha proteins had uneven and opposing distributions to the miRNAs. It appears that one of the most important facets underlying metastatic heterogeneity is the differential distribution of miR-20a and miR-20b and their regulation of target proteins.

GdCl3 abates hepatic ischemia-reperfusion injury by inhibiting apoptosis in rats.

BACKGROUND: Gadolinium chloride (GdCl(3)) is a specific inhibitor of Kupffer cells (KCs), which are important promoters of various liver injuries. It is therefore of interest to explore the role of KCs in liver ischemia-reperfusion injury and their relations with apoptosis caused by ischemia-reperfusion injury. METHODS: One hundred male Wistar rats (190-210 g, 6-7 weeks old) were divided into two groups at random, GdCl(3) group and control group. Samples were collected at 0.5, 1, 6, 12, and 24 hours from each group after reperfusion. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured by an automatic biochemical analyzer. TNF-alpha in serum was measured by enzyme-linked immunosorbent assay (ELISA). Malondialdehyde (MDA) in the liver mitochondria was measured by a colorimetric method. Pathological changes in the liver and immunohistochemical staining for caspase-3 were observed under an optical microscope. The ratio of apoptotic cells was measured by TdT-mediated dUTP nick-end labeling (TUNEL), and ultrastructural features of apoptosis were observed with a transmission electron microscope (TEM). RESULTS: The levels of ALT in the GdCl(3) group were lower than those in the control group after reperfusion for 0.5, 1, 6 and 12 hours (P<0.05); and the levels of AST in the GdCl(3) group were lower than those in the control group after reperfusion for 6 and 12 hours (P<0.05). The levels of TNF-alpha in the GdCl(3) group were lower than those in the control group after reperfusion for each time (P<0.05). The concentrations of MDA after reperfusion in the GdCl(3) group were lower than those in the control group after reperfusion for 6, 12 and 24 hours (P<0.05). After reperfusion for 0.5, 1, 6 and 12 hours, the integral optical density (IOD) of caspase-3-positive cells was lower in the GdCl(3) group than in the control group (P<0.05). After reperfusion for 1, 6, and 12 hours, the IOD of cells stained by TUNEL in the GdCl(3) group was lower than that in the control group (P<0.05). CONCLUSIONS: GdCl(3) inhibits the activity of ALT, AST and TNF-alpha, decreases the accumulation of MDA in mitochondria, and depresses the expression of caspase-3 in liver after ischemia-reperfusion. This may be an important protective mechanism by depressing KCs and indirectly inhibiting liver cell apoptosis.

Protective effect of ischemic preconditioning on hepatic ischemia-reperfusion injury by advancing the expressive phase of survivin in rats.

BACKGROUND: Survivin is a new and important gene in the regulation of apoptosis. It is very important to explore the effect of the expression of survivin protein caused by ischemia-reperfusion (IR) injury. The effect of IR injury caused by ischemic preconditioning (IP) on the liver in rats and the relation between the protective effect of IP and the expression of survivin are unclear. METHODS: One hundred and fifty male Wistar rats (weighing 190-210 g, aged 6-7 weeks) were divided into three groups at random: ischemic preconditioning (IP), ischemia-reperfusion (IR) and sham-operation (SO). Sample specimens were collected from each group at 6, 12, 24, 48, and 72 hours after reperfusion. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured by an automatic biochemical analyzer. Malondialdehyde (MDA) in liver tissue was measured. Pathological changes in the liver and immunohistochemical staining for survivin were determined with an optical microscope. RESULTS: The ALT levels in the IP and IR groups after reperfusion at each time were higher than those in the SO group (P<0.05), whereas after reperfusion for 6 and 12 hours, the ALT levels in the IP group were lower than those in the IR group (P<0.05). The AST levels in all IP and IR groups were higher than those in the SO group (P<0.05), whereas after reperfusion for 12, 24, 48 and 72 hours, the AST levels in the IP group were lower than those in the IR group (P<0.05). The MDA concentrations after reperfusion in the IP group were lower than those in the IR group (P<0.05), though the MDA concentrations in the IP and IR groups increased in contrast to those in the SO group after reperfusion at each time (P<0.05). After reperfusion for 12, 24, 48 and 72 hours, the number of survivin-positive cells was larger in the IP and IR groups than in the SO group (P<0.05). After reperfusion for 12, 24, and 48 hours the number of survivin-positive cells in the IP group increased compared with that in the IR group (P<0.05). CONCLUSIONS: IR increases the protein expression of survivin in liver tissue. IP inhibits the accumulation of MDA, advances the expressive phase of survivin protein in hepatic tissue, and improves liver function.

Melatonin protects liver from intestine ischemia reperfusion injury in rats.

AIM: To investigate the protective effect of melatonin on liver after intestinal ischemia-reperfusion injury in rats. METHODS: One hundred and fifty male Wistar rats, weighing 190-210 g, aged 7 wk, were randomly divided into melatonin exposure group, alcohol solvent control group and normal saline control group. Rats in the melatonin exposure group received intraperitoneal (IP) melatonin (20 mg/kg) 30 min before intestinal ischemia-reperfusion (IR), rats in the alcohol solvent control group received the same concentration and volume of alcohol, and rats in the normal saline control group received the same volume of normal saline. Serum samples were collected from each group 0.5, 1, 6, 12, and 24 h after intestinal IR. Levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured with an auto-biochemical analyzer. Serum TNF-alpha was tested by enzyme-linked immunosorbent assay (ELISA). Malondialdehyde (MDA) in liver was detected by colorimetric assay. Pathological changes in liver and immunohistochemical straining of ICAM-1 were observed under an optical microscope. RESULTS: The levels of ALT measured at various time points after intestinal IR in the melatonin exposure group were significantly lower than those in the other two control groups (P < 0.05). The serum AST levels 12 and 24 h after intestinal IR and the ICAM-1 levels (%) 6, 12 and 24 h after intestinal IR in the melatonin exposure group were also significantly lower than those in the other two control groups (P < 0.05). CONCLUSION: Exotic melatonin can inhibit the activity of ALT, AST and TNF-alpha, decrease the accumulation of MDA, and depress the expression of ICAM-1 in liver after intestinal IR injury, thus improving the liver function.

Melatonin abates liver ischemia/reperfusion injury by improving the balance between nitric oxide and endothelin.

BACKGROUND: Melatonin exerts complex physiological and pharmacological effects on multiple systems and organs. We hypothesized that melatonin might abate ischemia/reperfusion (I/R) injury in the liver by inhibiting excessive oxidative stress and keeping nitric oxide (NO) from being scavenged by free radicals. The aim of the present study was to investigate whether melatonin protects the liver from I/R injury and, if so, by what underlying mechanism. METHODS: Under anesthesia, Wistar rats were intraperitoneally injected with 20 mg/kg melatonin (dissolved in physiological saline containing 4% ethanol, Mel group), 4% alcohol (Alc group), or physiological saline (NS group). The artery, portal vein and bile duct of the left lobe of the liver were clamped for 60 minutes and then released. At different time points after I/R, the rats were sacrificed and blood samples were collected to measure the levels of serum alanine aminotransferase (ALT), lactic dehydrogenase (LDH), and NO. Hepatic tissue samples were collected for measuring endothelin expression by immunohistochemical staining and for routine morphological and histological examination. RESULTS: The levels of both ALT and LDH in the Mel group were significantly reduced for up to 24 hours after I/R compared with the Alc and NS groups (P<0.05). The levels of NO in the Mel group were significantly elevated for up to 12 hours after I/R relative to the NS group (P<0.05). The NO levels were also elevated at 0.5 and 6 hours after I/R in the Alc group (P<0.05). The immunohistochemical staining of hepatic tissue showed that endothelin-positive cells were significantly fewer in the Mel group than in the Alc and NS groups at 6 hours after I/R (P<0.01). The necrosis of hepatocytes and the destruction of hepatic cords in the Alc and NS groups were greatly improved in Mel-treated rats, which is in concert with our functional data. CONCLUSIONS: Pretreatment with melatonin increased NO bioavailability and decreased endothelin expression, and consequently played a protective role in preserving both liver function and structure during ischemia and reperfusion injury.