Functional Characterization of the MeSSIII-1 Gene and Its Promoter from Cassava.

Soluble starch synthases (SSs) play important roles in the synthesis of cassava starch. However, the expression characteristics of the cassava SSs genes have not been elucidated. In this study, the MeSSIII-1 gene and its promoter, from SC8 cassava cultivars, were respectively isolated by PCR amplification. MeSSIII-1 protein was localized to the chloroplasts. qRT-PCR analysis revealed that the MeSSIII-1 gene was expressed in almost all tissues tested, and the expression in mature leaves was 18.9 times more than that in tuber roots. MeSSIII-1 expression was induced by methyljasmonate (MeJA), abscisic acid (ABA), and ethylene (ET) hormones in cassava. MeSSIII-1 expression patterns were further confirmed in proMeSSIII-1 transgenic cassava. The promoter deletion analysis showed that the -264 bp to -1 bp MeSSIII-1 promoter has basal activity. The range from -1228 bp to -987 bp and -488 bp to -264 bp significantly enhance promoter activity. The regions from -987 bp to -747 bp and -747 bp to -488 bp have repressive activity. These findings will provide an important reference for research on the potential function and transcriptional regulation mechanisms of the MeSSIII-1 gene and for further in-depth exploration of the regulatory network of its internal functional elements.

Pain Sensitivity and Acute Postoperative Pain in Patients Undergoing Abdominal Surgery: The Mediating Roles of Pain Self-Efficacy and Pain Catastrophizing.

BACKGROUND: Inadequately managed postoperative pain remains a common issue. Examining factors like pain sensitivity, pain catastrophizing, and pain self-efficacy can help improve postoperative pain management. While these factors have been identified as potential predictors of acute postoperative pain, their effects have been inconsistent. Few studies have explored the interactions between these factors. AIM: To investigate the influence of preoperative pain sensitivity, pain catastrophizing, and pain self-efficacy on acute postoperative pain in abdominal surgery patients and to determine the mediating roles of pain catastrophizing and pain self-efficacy in the relationship between pain sensitivity and acute postoperative pain, as per the gate control theory. METHODS: A total of 246 patients were enrolled in this study. General information was collected before surgery, and the Pain Sensitivity Questionnaire (PSQ), Pain Catastrophizing Scale (PCS), and Pain Self-Efficacy Questionnaire (PSEQ) were administered. After surgery, patients' average pain scores over the 24 hours were reported using the Numerical Rating Scale (NRS). Correlation analyses and a structural equation model were used to examine the relationships among these variables. RESULTS: NRS scores over 3 during the 24 hours post-surgery were reported by 21.54% of patients. Postoperative acute pain was found to be associated with pain sensitivity (rs = 0.463, p < .001), pain catastrophizing (rs = 0.328, p < .001), and pain self-efficacy (rs = -0.558, p < .001). A direct effect on postoperative acute pain was exerted by pain sensitivity (effect = 0.250, p = .001), along with indirect effects through: (A) pain catastrophizing (effect = 0.028, p = .001); (B) pain self-efficacy (effect = 0.132, p = .001); and (C) the chain mediation of pain self-efficacy and pain catastrophizing (effect = 0.021, p = .008). CONCLUSIONS: The severity of postoperative acute pain can be predicted by pain self-efficacy and pain catastrophizing, and the connection between moderate pain sensitivity and postoperative acute pain severity is mediated by them. Therefore, intervention programs aimed at boosting pain self-efficacy and reducing pain catastrophizing can enhance postoperative pain outcomes for abdominal surgery patients.

A Transformation and Genome Editing System for Cassava Cultivar SC8.

Cassava starch is a widely used raw material for industrial production. South Chinese cassava cultivar 8 (Manihot esculenta Crantz cv. SC8) is one of the main locally planted cultivars. In this study, an efficient transformation system for cassava SC8 mediated with Agrobacterium strain LBA4404 was presented for the first time. Cassava friable embryogenic calli (FECs) were transformed through the binary vector pCAMBIA1304 harboring GUS- and GFP-fused genes driven by the CaMV35S promoter. The transformation efficiency was increased in the conditions of Agrobacterium strain cell infection density (OD600 = 0.65), 250 µM acetosyringone induction, and agro-cultivation with wet FECs for 3 days in dark. Based on the optimized transformation protocol, approximately 120-140 independent transgenic lines per mL settled cell volume (SCV) of FECs were created by gene transformation in approximately 5 months, and 45.83% homozygous mono-allelic mutations of the MePDS gene with a YAO promoter-driven CRISPR/Cas9 system were generated. This study will open a more functional avenue for the genetic improvement of cassava SC8.

The Unique Contribution of Past Bullying Experiences to the Presence of Psychosis-Like Experiences in University Students.

Objectives: Both bullying and psychosis-like experiences (PLEs) have gained much attention in recent years, but their interactions are not fully unraveled. The aim of the current study was to validate the Chinese version of Bullying Scale for Adults (C-BSA), and to investigate whether past bullying experiences independently predict the presence of PLEs in university students. Methods: The validity and reliability of the C-BSA were determined in two independent samples. A battery of psychological inventories was also administered to assess the presence of PLEs, maltreatment history in the family, and current depression and anxiety, including the 15-item positive subscale of the community assessment of psychic experiences (CAPE-p15), the Chinese version of the Childhood Trauma Questionnaire (CTQ), Self-Rating Depression Scale (SDS), and Self-Rating Anxiety Scale (SAS). Results: In the construction sample (N = 629), a Cronbach's α of 0.921 indicated a good internal consistency of C-BSA. The exploratory factor analysis (EFA) yielded a four-factor model and a three-factor model, and both were verified by using the confirmatory factorial analysis (CFA) in the validation sample (N = 629). The total scores of C-BSA were significantly correlated with that of CTQ, CAPE-p15, SDS, and SAS. Multivariate logistic regression revealed that bullying was associated with 2.0 or 3.7 times of risk for the presence of PLEs (numbers of bullying types < = 3 or > 3, respectively) after controlling for CTQ, SDS, and SAS scores. Conclusions: C-BSA has shown good psychometric properties in college students. The contribution of past bullying experiences to the present PLEs seems to be independent of other childhood trauma, current depression, and anxiety.

Non-invasive assessment of early stage diabetic nephropathy by DTI and BOLD MRI.

OBJECTIVE: Patients with diabetes mellitus, diabetic nephropathy (DN) and healthy donor were analyzed to test whether the early DN patients can be detected using both blood oxygenation level dependent (BOLD) and diffusion tensor imaging. METHODS: This study was approved by the Ethics Committee of our hospital. MR images were acquired on a 3.0-Tesla MR system (Discovery MR750, General Electric, Milwaukee, WI). 30 diabetic patients were divided into NAU (normal to mildly increased albuminuria, N = 15) and MAU (moderately increased albuminuria, N = 15) group based on the absence or presence of microalbuminuria. 15 controls with sex- and age-matched were enrolled in the study. Prior to MRI scan, all participants were instructed to collect their fresh morning urine samples for quantitative measurement of urinary microalbumin and urinary creatinine. Then, the estimations of serum creatinine, serum uric acid, HbAlc and fasting plasma glucose as well as fundus examinations were performed in all subjects. Then, the values of albumin-creatinine ratio (ACR) and estimated glomerular filtration rate were also calculated. All subjects underwent renal diffusion tensor imaging (DTI) and BOLD acquisition after fasting for 4 h. Regions of interest were placed in renal medulla and cortex for evaluating apparent diffusion coefficient (ADC), fractional anisotropy (FA) and R2* values by two experienced radiologists. The consistency between the two observations was estimated using intragroup correlation coefficients. To test differences in ADC, FA and R2* values across the three groups, the data were analyzed using separate one-way ANOVAs. Post-hoc pair wise comparisons were then performed using t-test. To investigate the clinical relevance of imaging parameters in both regions across the three groups, the correlations of values of the ACR/estimated glomerular filtration rate and of the ADC/FA/R2* were calculated. RESULTS: There was a high level of consistency of those ADC, FA and R2* values across the three groups on both renal cortex and medulla measured by the two doctors. The FA value of medulla in MAU group was lower than that in control (p < 0.01). The R2* value of medulla in the NAU group was higher than that in the control (p < 0.01), and the R2* value of medulla in the MAU group was lower than that in the control (p = 0.009) . Moreover, the current study revealed a decreasing trend in FA values of the renal medulla from the control group to NAU and MAU groups. Finally, a weak negatively correlation between medullary R2* and ACR was found in current study. CONCLUSION: Medullary R2* value might be a new more sensitive predictor of early DN. Meanwhile, BOLD imaging detected the medullary hypoxia at the simply diabetic stage, while DTI didn't identify the medullary directional diffusion changes at this stage. Based on our assumption mentioned above, it's presumable that BOLD imaging may be more sensitive for assessment of the early renal function changes than DTI. These imaging techniques are more accurate and practical than conventional tests. ADVANCES IN KNOWLEDGE: Non-invasive MRI was used to detect renal function changes at early DN stage.

Protective effects of tenuifolin isolated from Polygala tenuifolia Willd roots on neuronal apoptosis and learning and memory deficits in mice with Alzheimer's disease.

The roots of Polygala tenuifolia Willd have a long history of being used as a traditional Chinese medicine for the treatment of insomnia, forgetfulness, sorrow and depression. Tenuifolin (TEN) has been isolated from Polygala tenuifolia Willd roots, and this study was carried out to investigate the potential beneficial effects of TEN on neuronal apoptosis and memory deficits in a mouse model of Alzheimer's disease (AD). TEN treatment reversed spatial learning and memory deficits, as well as neuronal apoptosis in hippocampal areas, in APP/PS1 transgenic AD mice. TEN treatment protected against Aß25-35-induced apoptosis, loss of mitochondria-membrane potential, and activation of caspases-3 and -9 in SH-SY5Y cells. TEN has potential benefit in treating learning and memory deficits in APP/PS1 transgenic AD mice, and its effects may be associated with reversing AD pathology-induced neuronal apoptosis. These insights pave the way for further analysis of the potential of TEN as an AD therapeutic agent.

The extract from Agkistrodon halys venom protects against lipopolysaccharide (LPS)-induced myocardial injury.

BACKGROUND: Snake venoms contain various bioactive constituents which possess potential therapeutic effects. The aim of this work was to investigate the effect of the extract from Agkistrodon halys venom on lipopolysaccharide (LPS)-induced myocardial injury. METHODS: Thirty male Sprague-Dawley rats were randomly assigned to three groups (10 rats per group): control group, LPS group and LPS + extract group. Rats in control and the LPS groups were intravenously injected with sterile saline solution, and rats in the LPS + extract group with the extract. After 2 h, rats of the control group were intraperitoneally injected sterile saline solution, and rats in the LPS and the LPS + extract groups were treated with LPS (20 mg per kg body weight). Levels of creatine kinase (CK) and lactate dehydrogenase (LDH) in serum were determined. Anti-inflammation of the extract was analyzed via determination of TNF-α and IL-6 in serum, and expression of TNF-α, IL-6, COX-2 and p-ERK protein in hearts. Heme oxygenase-1 (HO-1) and p-NF-κB protein expression in hearts, superoxide dismutase (SOD) activity and malondialdehyde (MDA) level in serum were used to evaluate the anti-oxidative properties of the extract. RESULTS: Extract pretreatment significantly decreased the level of serum CK and LDH, reduced the generation of inflammatory cytokines such as TNF-α and IL-6, and also reduced serum level of MDA in the LPS + extract group compared with the LPS group. In addition, the extract increased SOD activity in serum, HO-1 protein expression in hearts, and decreased TNF-α, IL-6, COX-2, p-NF-κB and p-ERK1/2 protein expression. CONCLUSION: Our results suggested that beneficial effect of this extract might be associated with an improved anti-oxidation and anti-inflammatory effect via downregulation of NF-κB/COX-2 signaling by activating HO-1/CO in hearts.

Elevated RBP4 plasma levels were associated with diabetic retinopathy in type 2 diabetes.

The retinol-binding protein 4 (RBP4) has been postulated to play a role in glucose homeostasis, insulin resistance, and diabetes mellitus in human and animal studies. The aim of the present study was to evaluate the role of RBP4 in Chinese patients with type 2 diabetes mellitus with and without diabetic retinopathy (DR). Plasma RBP4 concentrations were tested in 287 patients with type 2 diabetes. At baseline, demographic and clinical information including presence of DR and vision-threatening DR (VTDR) was collected. The relationship between RBP4 and DR (VTDR) was investigated using logistic regression. Patients with DR or VTDR had significantly higher plasma levels of RBP4 on admission (P<0.0001). Receiver operating characteristics (ROCs) to predict DR and VDTR demonstrated areas under the curve for RBP4 of 0.79 (95% confidence interval (CI): 0.73-0.85) and 0.90 (95% CI: 0.85-0.94), respectively, which were superior to other factors. For each 1 µg/ml increase in plasma level of RBP4, the unadjusted and adjusted risk of DR would be increased by 8% (with the odds ratio (OR) of 1.08 (95% CI: 1.05-1.13), P<0.001) and 5% (1.05 (1.02-1.11), P=0.001), respectively. It was 12% (with the OR of 1.12 (95% CI: 1.07-1.18), P<0.001) and 9% (1.09 (1.05-1.15), P<0.001) for VTDR. The present study shows that elevated plasma levels of RBP4 were associated with DR and VDTR in Chinese patients with type 2 diabetes, suggesting a possible role of RBP4 in the pathogenesis of DR complications. Lowering RBP4 could be a new strategy for treating type 2 diabetes with DR.

[Eating Frequency and Gestational Weight Gain and Its Association with Birth Body Mass of Neonates: a Birth Cohort Study].

OBJECTIVE: To determine the association of eating frequency (EF) and gestational weight gain (GWG) with birth body mass of neonates. METHODS: A prospective cohort study was conducted on 578 healthy pregnant women from April to October 2015. Dietary intake and physical activity data per trimester were collected using a questionnaire. Data in relation to gestational body mass,gestational stage and birth body mass of neonates were obtained from clinical records. Multiple logistic regression models were established to test the impacts of EF and GWG on appropriate for gestational age (AGA). Multiple linear regression analyses were performed to determine the association between EF and birth body mass of neonates. RESULTS: A final sample of 503 eligible pregnant women (87.02%) was included in data analyses. Higher EF [odds ratio (OR)=2.03; 95% confidence interval (CI): 1.18-3.47] and snacks (OR=1.84; 95%CI: 1.08-3.15) in the first trimester were associated with increased risk of excessive GWG,after controlling for maternal age,education,average household income,physicalactivity,numbers of pregnancy,numbers of delivery,and dietary intake (protein,fat,carbohydrate). A meal frequency greater (OR=2.83; 95%CI: 1.07-4.58) or less (OR=1.92; 95%CI: 1.08-3.61) than three in the first trimester was also associated with increased risk of large or small for gestational age. Meal frequency in the first trimester was positively correlated with birth body mass of neonates (ß=236.17; P<0.01). CONCLUSION: Frequent eating and snacks in the first trimester are associated with increased risks of excessive GWG. Meal frequency in the first trimester is also positively correlated with birth body mass of neonates: three meals per day is a protective factor of AGA.

Identification, Expression, and Functional Analysis of the Fructokinase Gene Family in Cassava.

Fructokinase (FRK) proteins play important roles in catalyzing fructose phosphorylation and participate in the carbohydrate metabolism of storage organs in plants. To investigate the roles of FRKs in cassava tuber root development, seven FRK genes (MeFRK1-7) were identified, and MeFRK1-6 were isolated. Phylogenetic analysis revealed that the MeFRK family genes can be divided into α (MeFRK1, 2, 6, 7) and ß (MeFRK3, 4, 5) groups. All the MeFRK proteins have typical conserved regions and substrate binding residues similar to those of the FRKs. The overall predicted three-dimensional structures of MeFRK1-6 were similar, folding into a catalytic domain and a ß-sheet ''lid" region, forming a substrate binding cleft, which contains many residues involved in the binding to fructose. The gene and the predicted three-dimensional structures of MeFRK3 and MeFRK4 were the most similar. MeFRK1-6 displayed different expression patterns across different tissues, including leaves, stems, tuber roots, flowers, and fruits. In tuber roots, the expressions of MeFRK3 and MeFRK4 were much higher compared to those of the other genes. Notably, the expression of MeFRK3 and MeFRK4 as well as the enzymatic activity of FRK were higher at the initial and early expanding tuber stages and were lower at the later expanding and mature tuber stages. The FRK activity of MeFRK3 and MeFRK4 was identified by the functional complementation of triple mutant yeast cells that were unable to phosphorylate either glucose or fructose. The gene expression and enzymatic activity of MeFRK3 and MeFRK4 suggest that they might be the main enzymes in fructose phosphorylation for regulating the formation of tuber roots and starch accumulation at the tuber root initial and expanding stages.

Knockdown of Expression of Cdk5 or p35 (a Cdk5 Activator) Results in Podocyte Apoptosis.

Podocytes are terminally differentiated glomerular epithelial cells. Podocyte loss has been found in many renal diseases. Cdk5 is a cyclin-dependent protein kinase which is predominantly regulated by p35. To study the role of Cdk5/p35 in podocyte survival, we first applied western blotting (WB) analysis to confirm the time-course expression of Cdk5 and p35 during kidney development and in cultured immortalized mouse podocytes. We also demonstrated that p35 plays an important role in promoting podocyte differentiation by overexpression of p35 in podocytes. To deregulate the expression of Cdk5 or p35 in mouse podocytes, we used RNAi and analyzed cell function and apoptosis assaying for podocyte specific marker Wilms Tumor 1 (WT1) and cleaved caspase 3, respectively. We also counted viable cells using cell counting kit-8. We found that depletion of Cdk5 causes decreased expression of WT1 and apoptosis. It is noteworthy, however, that downregulation of p35 reduced Cdk5 activity, but had no effect on cleaved caspase 3 expression. It did, however, reduce expression of WT1, a transcription factor, and produced podocyte dysmorphism. On the other hand increased apoptosis could be detected in p35-deregulated podocytes using the TUNEL analysis and immunofluorescent staining with cleaved caspase3 antibody. Viability of podocytes was decreased in both Cdk5 and p35 knockdown cells. Knocking down Cdk5 or p35 gene by RNAi does not affect the cycline I expression, another Cdk5 activator in podocyes. We conclude that Cdk5 and p35 play a crucial role in maintaining podocyte differentiation and survival, and suggest these proteins as targets for therapeutic intervention in podocyte-damaged kidney diseases.

Heme Oxygenase-1 Promotes Delayed Wound Healing in Diabetic Rats.

Diabetic ulcers are one of the most serious and costly chronic complications for diabetic patients. Hyperglycemia-induced oxidative stress may play an important role in diabetes and its complications. The aim of the study was to explore the effect of heme oxygenase-1 on wound closure in diabetic rats. Diabetic wound model was prepared by making an incision with full thickness in STZ-induced diabetic rats. Wounds from diabetic rats were treated with 10% hemin ointment for 21 days. Increase of HO-1 protein expression enhanced anti-inflammation and antioxidant in diabetic rats. Furthermore, HO-1 increased the levels of VEGF and ICAM-1 and expressions of CBS and CSE protein. In summary, HO-1 promoted the wound closure by augmenting anti-inflammation, antioxidant, and angiogenesis in diabetic rats.

[Adsorption Behavior of Pb(â ¡) Ion Imprinted Magnetic Composite Adsorbent in Aqueous Solution by FAAS].

Pb(Ⅱ) Ion Imprinted Magnetic Composite Adsorbent (Pb(Ⅱ)-MICA) was prepared for the quick separation of Pb(Ⅱ) from aqueous solutions by bulk polymenrization with chitosan as the functional monomer, the magnetic iron oxide nano-particles as carrier and epichlorohydrin as the cross-link agent. The Pb(Ⅱ)-MICA and MNICA were characterized by FTIR. The Effects of the adsorption process including pH, contact time, initial concentration and temperature were investigated by FAAS. It was found that with the increasing of PH value, the adsorption capacity of Pb(Ⅱ)-MICA for Pb(Ⅱ) reached the peak in the range of pH 5.0～6.0. The maximum adsorption capacity was 32.48 mg·g-1 when the adsorption time was up to 120 min. The relative selectivity coefficient of Pb(Ⅱ) and other metal ion on Pb(Ⅱ) -MICA were 28.11, 91.14, 76.54, 33.06 times compared with MNICA. The results show that the Pb(Ⅱ)-MICA displayed strong affinity for Pb(Ⅱ) in the solution and exhibited selectivity for Pb(Ⅱ) ion in the presence of Cu2+，Cd2+，Ni2+ and Zn2+. The Langmuir adsorption isotherm models were fit to the adsorption equilibrium data well (r2=1, the saturation adsorption capacities were 33.87 mg·g-1). The adsorption dynamics and thermodynamics of Pb(Ⅱ) -MICA for Pb(Ⅱ) were investigated, the results indicated a Langmuir mono-layer mode process of Pb(Ⅱ) on the Pb(Ⅱ)-MICA was dominated by chemical action. An exothermic and spontaneous adsorption process of Pb(Ⅱ) on the Pb(Ⅱ)-MICA was driven by enthalpy.

[Stabilization of Cadmium Contaminated Soils by Ferric Ion Modified Attapulgite (Fe/ATP)--Characterizations and Stabilization Mechanism].

Ferric ion modified attapulgite (Fe/ATP) was prepared by impregnation and its structure and morphology were characterized. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effect of Cadmium( Cd) stabilization in soil with the addition of attapulgite (ATP) and Fe/ATP. The stabilization mechanism of Cd was further elucidated by comparing the morphologies and structure of ATP and Fe/ATP before and after Cd adsorption. Fe/ATP exhibited much better adsorption capacity than ATP, suggesting different adsorption mechanisms occurred between ATP and Fe/ATP. The leaching concentrations of Cd in soil decreased by 45% and 91% respectively, with the addition of wt. 20% ATP and Fe/ATP. The former was attributed to the interaction between Cd2 and --OH groups by chemical binding to form inner-sphere complexes in ATP and the attachment between Cd2+ and the defect sites in ATP framework. Whereas Cd stabilization with Fe/ATP was resulted from the fact that the active centers (--OH bonds or O- sites) on ATP could react with Fe3+ giving Fe--O--Cd-- bridges, which helped stabilize Cd in surface soil. What'more, the ferric oxides and metal hydroxides on the surface of ATP could interact with Cd, probably by the formation of cadmium ferrite. In conclusion, Fe/ATP, which can be easily prepared, holds promise as a potential low-cost and environmental friendly stabilizing agent for remediation of soil contaminated with heavy metals.

Ginkgolide B increases hydrogen sulfide and protects against endothelial dysfunction in diabetic rats.

AIM: To evaluate the effect of ginkgolide B treatment on vascular endothelial function in diabetic rats. METHODS: The study included four groups with 15 male Sprague-Dawley rats: control group; control group treated with ginkgolide B; diabetic group; and diabetic treated with ginkgolide B. The activity of superoxide dismutase (SOD), malondialdehyde content, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits, and glutathione peroxidase 1 (GPX1) protein expression were determined in aortic tissues. Vasoconstriction to phenylephrine (PHE) and vasorelaxation to acetylcholine (Ach) and sodium nitroprusside (SNP) were assessed in aortic rings. Nitric oxide (NO) and hydrogen sulfide (H2S) were measured, as well as cystathionine γ lyase (CSE) and cystathionine ß synthetase (CBS) protein expression, and endothelial nitric oxide synthase (eNOS) activity. RESULTS: Diabetes significantly impaired PHE-induced vasoconstriction and Ach-induced vasorelaxation (P<0.001), reduced NO bioavailability and H2S production (P<0.001), SOD activity, and GPX1 protein expression (P<0.001), and increased malondialdehyde content and NADPH oxidase subunits, and CSE and CBS protein expression (P<0.001). Ginkgolide B treatment improved PHE vasoconstriction and Ach vasorelaxation (P<0.001), restored SOD (P=0.005) and eNOS (P<0.001) activities, H2S production (P=0.044) and decreased malondialdehyde content (P=0.014). Vasorelaxation to SNP was not significantly different in control and diabetic rats with or without ginkgolide B treatment. Besides, ginkgolide B increased GPX1 protein expression and reduced NADPH oxidase subunits, CBS and CSE protein expression. CONCLUSION: Ginkgolide B alleviates endothelial dysfunction by reducing oxidative stress and elevating NO bioavailability and H2S production in diabetic rats.

Insights into the effects of 2:1 "sandwich-type" crown-ether/metal-ion complexes in responsive host-guest systems.

In-depth investigations of the specific ion-responsive characteristics based on 2:1 "sandwich" structures and effects of crown ether cavity sizes on the metal-ion/crown-ether complexation are systematically performed with a series of PNIPAM-based responsive copolymers containing similar contents of crown ether units with different cavity dimensions (12-crown-4 (12C4), 15-crown-5 (15C5), 18-crown-6 (18C6)). The lower critical solution temperature (LCST) values of copolymers in deionized water shift to lower temperatures gradually when the crown ether contents increase or the ring sizes decrease from 18C6 to 12C4. With increasing the concentrations of alkali metal ions (Na(+), K(+), Cs(+)) or the contents of pendent crown ether groups, the copolymers with different crown ether cavity sizes exhibit higher selectivity and sensitivity to corresponding cations. Importantly, the ion sensitivities of the copolymers in response to corresponding alkali metal ions increase dramatically with an increase in the crown ether cavity size. Interestingly, a linear relationship between the crown ether cavity size and the diameter of corresponding cation for the formation of stable 2:1 "sandwich" complexes is found for the first time, from which the size of metal ions or other guests that able to form 2:1 "sandwich" complexes with crown ethers can be deduced. The results in this work are valuable and useful for further developments and practical applications of various crown-ether-based smart materials.

Cdk5 inhibitory peptide (CIP) inhibits Cdk5/p25 activity induced by high glucose in pancreatic beta cells and recovers insulin secretion from p25 damage.

Cdk5/p25 hyperactivity has been demonstrated to lead to neuron apoptosis and degenerations. Chronic exposure to high glucose (HG) results in hyperactivity of Cdk5 and reduced insulin secretion. Here, we set out to determine whether abnormal upregulation of Cdk5/p25 activity may be induced in a pancreatic beta cell line, Min6 cells. We first confirmed that p25 were induced in overexpressed p35 cells treated with HG and increased time course dependence. Next, we showed that no p25 was detected under short time HG stimulation (4-12 hrs), however was detectable in the long exposure in HG cells (24 hrs and 48 hrs). Cdk5 activity in the above cells was much higher than low glucose treated cells and resulted in more than 50% inhibition of insulin secretion. We confirmed these results by overexpression of p25 in Min6 cells. As in cortical neurons, CIP, a small peptide, inhibited Cdk5/p25 activity and restored insulin secretion. The same results were detected in co-infection of dominant negative Cdk5 (DNCdk5) with p25. CIP also reduced beta cells apoptosis induced by Cdk5/p25. These studies indicate that Cdk5/p25 hyperactivation deregulates insulin secretion and induces cell death in pancreatic beta cells and suggests that CIP may serve as a therapeutic agent for type 2 diabetes.

Taurine attenuates oxidative stress and alleviates cardiac failure in type I diabetic rats.

AIM: To investigate cardioprotective effect of taurine in diabetic rats. METHODS: Male Sprague-Dawley rats were assigned randomly into four groups of 15 rats: control group, control+taurine group, streptozotocin (STZ) group, and STZ + taurine group. Rats in STZ and STZ+ taurine groups were treated by a single injection of STZ (70 mg kg-1, intraperitoneally) dissolved in 0.01 M citrate buffer (pH 4.5) for induction of diabetes, and rats in control and control+taurine groups were treated with the same volume citrate buffer. Taurine was orally administered to rats in control+taurine and STZ + taurine groups daily for 8 weeks. Rats were examined for diabetic cardiomyopathy by left ventricular (LV) hemodynamic analysis. Myocardial oxidative stress was assessed by measuring the activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA). Myocardial protein kinase B (Akt/PKB) phosphorylation and heme oxygenase-1 (HO-1) protein levels were measured by Western blot in all rats at the end of the study. RESULTS: In untreated diabetic rats, LV systolic pressure, rate of pressure rise, and rate of pressure fall were decreased, while LV end-diastolic pressure was increased, indicating reduced LV contractility and slowing of LV relaxation. The levels of Akt/PKB phosphorylation and SOD activity were decreased and HO-1 protein expression and MDA content increased. Taurine treatment significantly improved LV systolic and diastolic function, and there were persistent increases in activities of Akt/PKB and SOD, and the level of HO-1 protein. CONCLUSION: Taurine treatment ameliorates myocardial function and heart oxidant status, while increasing myocardial Akt/PKB phosphorylation, and HO-1 levels have beneficial effects on diabetic cardiomyopathy.

[Spatial distribution of perfluorooctanoic acids and perfluorinate sulphonates in surface water of East Lake].

Concentrations and spatial distribution of PFOS and PFOA in surface water from East Lake in Wuhan, Hubei, China were studied. The total concentration of PFCs ranged from 31.1 to 237 ng x L(-1), and the mean value was 115 ng x L(-1), revealing lake-wide contamination in East Lake. PFOS and PFOA were detected in all samples with maximum values of 132 ng x L(-1) and 158 ng x L(-1), respectively, whereas the mean values of PFOS and PFOA were 60.4 and 55.0 ng x L(-1), respectively. The highest concentrations of PFOS and PFOA were found in the eastern area of lake, followed by the southern area of lake, and the western and northern areas of East Lake were the least contaminated regions. The specific distribution and composition profile of PFOS and PFOA, and the lack of significant correlation between PFOS and PFOA, suggested that there were various sources of PFCs. The PFOS concentrations at 30 sample sites (63%) were greater than 43 ng x L(-1), which was used to estimate an avian wildlife value for PFOS. The PFOA concentrations at 20 sample sites (42%) were greater than 40 ng x L(-1), which was a health-based guidance level recommended by the State of New Jersey for PFOA.

[Degradation of 2, 4-dichlorophenol in aqueous solution by ZVI/EDDS/air system].

A new oxidation system of Fenton-like system (ZVI/EDDS/Air) has been developed to degrade 2,4-chlorophenols (2,4-DCP) in aqueous solution. The influences of initial conditions, i. e., EDDS concentration, iron dosage, aeration rate, 2,4-DCP concentration and pH as well as reaction temperature on the degradation of 2,4-DCP were studied. The results demonstrated that this ZVI/EDDS/Air system was able to effectively degrade 2,4-DCP in aqueous solution, and the degradation of 2,4-DCP conforms to the pseudo-first-order reaction kinetics equation. Removal of above 99% 2,4-DCP was achieved in ZVI/EDDS/Air system at room temperature and pressure after 1 h reaction when the initial conditions were 2,4-DCP 100 mg x L(-1), EDDS 0.80 mmo x L(-1), ZVI 20 g x L(-1), aeration rate 2 L x (min x L)(-1). Compared with ZVI/EDTA/Air system, ZVI/EDDS/Air system showed higher efficiency in the degradation of 2,4-DCP at ambient circumstance and was more environmentally benign.