I2-catalyzed synthesis of 3-aminopyrrole with homopropargylic amines and nitrosoarenes.

The synthesis of 3-aminopyrrole using the amination reagent nitrosoarenes and homopropargylic amines catalyzed by I2 through cyclization and amination has been developed. This protocol features excellent functional group tolerance and mild reaction conditions, yielding 3-aminopyrroles in moderate to good yields without a metal catalyst. This method realizes the construction and amination of the 3-aminopyrroles in which nitrosoarenes serve as the amine source and oxidant.

Mechanical and microstructural properties of recycling granite residual soil reinforced with glass fiber and liquid-modified polyvinyl alcohol polymer.

Glass fiber and liquid-modified polyvinyl alcohol polymer (SH Polymer) are used to reinforce granite residual soil. In this paper, scanning electron microscopy (SEM) tests and drop-weight tests were used to study the microscopic interaction mechanism and impact resistance of granite residual soil specimens reinforced by glass fiber and SH Polymer. Combined with the equivalent confining pressure theory, Mohr-Coulomb intensity lines were used to quantitatively analyze the reinforcement effect of glass fiber. The SEM results showed that the granite residual soil solidified by a 3.5 % SH polymer had a tighter bond between the flake clay particles. In addition, with the incorporation of glass fiber, these flake clay particles were cemented on the glass fiber along the long axis, forming a cementing system of flake clay particles and glass fiber. When the glass fiber content was 3.0 %, the impact resistance of the specimen reached its maximum, 32.16 kN. Using the equivalent confining pressure theory, the reinforcement effect of glass fiber on soil could be quantified by Δσ3.

Cu-Catalyzed Tandem Aerobic Oxidative Cyclization for the Synthesis of 3,3'-Bipyrroles from the Homopropargylic Amines.

A Cu-catalyzed method for the synthesis of 3,3'-bipyrroles from homopropargylic amines through tandem aerobic oxidative cyclization involving the formation of C-C bond has been developed. The features of this reaction are a small number of Cu catalysis and simple starting substrates. Moreover, this procedure exhibits good functional group tolerance and a series of 3,3'-bipyrroles derivatives are obtained in moderate to good yields.

AgNO2 as the NO Source for the Synthesis of Substituted Pyrazole N-Oxides from N-Propargylamines.

A straightforward method for synthesizing the pyrazole N-oxides from N-propargylamines and AgNO2 through oxidation/cyclization reaction had been developed. AgNO2 was used as the NO source for the first time to synthesize pyrazole N-oxides. Various substituted groups on N-propargylamines proceeded smoothly, and the desired products were obtained in good yields.

Protamine zinc insulin combined with sodium selenite improves glycometabolism in the diabetic KKAy mice.

Long-term, high dosage protamine zinc insulin (PZI) treatments produce adverse reactions. The trace element selenium (Se) is a candidate for the prevention of diabetes due to anti-oxidative stress activity and the regulation of glycometabolism. In this study, we aimed to investigate the anti-diabetic effects of a combination of PZI and Se on type 2 diabetes. Diabetic KKAy mice were randomized into the following groups: model group and groups that were subcutaneously injected with PZI, Se, high or low dose PZI + Se for 6 weeks. PZI combined with Se decreased the body weight and fasting blood glucose levels. Moreover, this treatment also improved insulin tolerance, as determined by the reduced values from the oral glucose tolerance test and insulin tolerance test, and increased insulin levels and insulin sensitivity index. PZI combined with Se ameliorated skeletal muscle and ß-cell damage and the impaired mitochondrial morphology. Oxidative stress was also reduced. Furthermore, PZI combined with Se upregulated phosphatidylinositol 3-kinase (PI3K) and downregulated protein tyrosine phosphatase 1B (PTP1B). Importantly, the low dosage combination produced effects similar to PZI alone. In conclusion, PZI combined with Se improved glycometabolism and ameliorated the tissue and mitochondrial damage, which might be associated with the PI3K and PTP1B pathways.

Liraglutide Exerts Antidiabetic Effect via PTP1B and PI3K/Akt2 Signaling Pathway in Skeletal Muscle of KKAy Mice.

Background. Liraglutide (a glucagon-like peptide 1 analog) was used for the treatment of type 2 diabetes (T2DM) which could produce glucose-dependent insulin secretion. Aim. The aim was to investigate whether liraglutide could improve myofibril and mitochondria injury in skeletal muscle and the mechanisms in diabetic KKAy mice. Method. We divided the male KKAy mice into 2 groups: liraglutide group (250 µg/kg/day liraglutide subcutaneous injection) and model group; meanwhile, the male C57BL/6J mice were considered as the control. After 6 weeks, the ultrastructure of skeletal muscle was observed by electron microscope. The gene expressions of protein tyrosine phosphatase 1B (PTP1B), phosphatidylinositol 3-kinase (PI3K), and glucose transporter type 4 (GLUT4) were determined by real-time PCR. The protein levels of the above molecules and phospho-Akt2 (p-Akt2) were measured by Western blot. Results. Liraglutide significantly ameliorated the injury of mitochondria by increasing the number (+441%) and the area (+113%) of mitochondria and mitochondrial area/100 µm(2) (+396%) in skeletal muscle of KKAy mice. The results of real-time PCR and Western blot showed that liraglutide downregulated PTP1B while it upregulated PI3K and GLUT4 (P < 0.01). The protein level of p-Akt2/Akt2 was also increased (P < 0.01). Conclusion. These results revealed that liraglutide could improve myofibril and mitochondria injury in skeletal muscle against T2DM via PTP1B and PI3K/Akt2 signaling pathway.

Effect of passive pile on 3D ground deformation and on active pile response.

Using a series of model tests, this study investigated the effect of a passive pile on 3D ground deformation around a laterally loaded pile and on that laterally loaded pile's response in sand. The active pile head was subjected to lateral loads, and the passive pile was arranged in front of the active pile. In the model tests, the distance between the two pile centers was set to zero (i.e., a single pile test), 2.5, 4, and 6 times the pile width (B). The 3D ground surface deformations around the active and passive piles were obtained using a newly developed Stereo-PIV technique. The experimental results showed that the ground surface movements were restrained by the passive pile when the pile spacing was less than 6B. The response of the active pile was affected by the passive pile when the pile spacing was less than 4B. This study combined the response of the active pile and surrounding 3D ground deformation to investigate the effect of the passive pile, which is useful to further understand the pile-soil-pile interactions and to enhance pile foundation design in engineering practice.

Liraglutide ameliorates glycometabolism and insulin resistance through the upregulation of GLUT4 in diabetic KKAy mice.

Liraglutide, a long-lasting glucagon­like peptide­1 analogue, has been used for the treatment of patients with type 2 diabetes mellitus since 2009. In this study, we investigated the anti-diabetic effects and mechanisms of action of liraglutide in a spontaneous diabetic animal model, using KK/Upj-Ay/J (KKAy) mice. The KKAy mice were divided into 2 groups, the liraglutide group (mice were treated with 250 µg/kg/day liraglutide) and the model group (treated with an equivalent amount of normal saline). C57BL/6J mice were used as the controls (treated with an equivalent amount of normal saline). The treatment period lasted 6 weeks. During this treatment period, fasting blood glucose (FBG) levels and the body weight of the mice were measured on a weekly basis. Our results revealed that liraglutide significantly decreased FBG levels, the area under the curve following a oral glucose tolerance test and insulin tolerance test, increased serum insulin levels, reduced homeostasis model assessment of insulin resistance and increased the insulin sensitivity index. Furthermore, liraglutide ameliorated glycometabolism dysfunction by increasing glycolysis via hexokinase and glycogenesis via pyruvate kinase activation. An ultrastructural examination of the pancreas revealed that liraglutide improved the damaged state of islet ß cells and increased the number of insulin secretory granules. The real-time PCR results revealed that the gene expression of glucose transporter 4 (GLUT4) increased following treatment with liraglutide. Liraglutide also upregulated the protein expression of GLUT4 in liver tissue and skeletal muscle. Our results suggest that liraglutide ameliorates glycometabolism and insulin resistance in diabetic KKAy mice by stimulating insulin secretion, increasing glycogenesis and glycolysis and upregulating the expression of GLUT4.

Optimizing the parameters of vagus nerve stimulation by uniform design in rats with acute myocardial infarction.

Vagus nerve stimulation (VNS) has been shown to improve left ventricular function and survival in rats with acute myocardial infarction (AMI), and this maneuver has also been adopted clinically for the treatment of patients with chronic heart failure (CHF). Recent in vitro and in vivo studies have suggested that VNS can modulate the level of pro-inflammatory factors. Despite the beneficial effects of VNS, the stimulation parameters for obtaining favorable outcomes appear highly variable. To optimize VNS parameters, we set up different stimulation protocols with different pulse width (1-2 ms), frequency (1-6 Hz), voltage (1-6 V) and duration (40-240 min) of VNS by uniform design (UD). Rats were divided into seven groups with (Group1-Group6) or without VNS (MI group). Our results demonstrate that (1) the parameter sets in Group1, Group2 and Group3 yield the best post-MI protection by VNS, while the protective role were not observed in Group4, Group5 and Group6; (2) baroreflex sensitivity and the α7 nicotinic acetylcholine receptor level were also increased in Group1, Group2 and Group3. (3) the parameter set in Group1 (G1:1 ms, 2 Hz, 3 V, 240 min) is judged the most optimal parameter in this study as rats in this group not only showed a reduced myocardial injury with better-preserved cardiac function compared with other groups, more important, but also exhibited minimal heart rate (HR) reduction. (4) the duration of VNS plays an important role in determining the protection effect of VNS. In conclusion, VNS displays a beneficial role in Group1, Group2 and Group3. Of note, the parameter set in Group1 provides the most optimal cardioprotective effect. These results may provide insight into development of novel treatment for ischemic heart diseases.

[Effect of combination of insulin and selenium on insulin signal transduction in cardiac muscle of STZ-induced diabetic rats].

This study is to investigate the effect of low doses of insulin (1 u x kg(-1)) and selenium (180 microg x kg(-1)) in combination on general physiological parameters and insulin signal molecules in cardiac muscle of STZ-induced diabetic rats. The levels of blood glucose were estimated using One Touch SureStep Blood Glucose meter. HbA1c levels were estimated using microcolumn assay. TG and TC were estimated using enzymatic assay. The levels of PI3K and GLUT4 in cardiac muscle were examined by immunoblotting and immunohistochemistry. The result showed that insulin in combination with selenium could significantly lower blood glucose and blood lipid levels and markedly restored the PI3K and GLUT4 levels in cardiac muscle. It could be concluded that there was cooperation between insulin and selenium, and that treatment of diabetic rats with combined doses of insulin and selenium increased cardiac glucose uptake by upregulating the level of PI3K-mediated GLUT4 in cardiac muscle, eventually ameliorating myocardial dysfunction.

Transfusion of autologous late-outgrowth endothelial cells reduces arterial neointima formation after injury.

AIMS: Late-outgrowth endothelial cells (OECs) exist in blood and other organs. We aimed to explore whether and how OECs participate in re-endothelialization and prevent vascular neointima formation after injury. METHODS AND RESULTS: Rabbit bone marrow OECs were cultured for 4 weeks to increase their numbers. Transfusion of autologous OECs (2 × 106-1 × 107/kg) soon after rabbit ear central artery injury reduced the increase in intima area and the decrease in lumen area observed at days 14 and 28. Transfusion of autologous OECs (1 × 107/kg) ameliorated some early (days 2 and 7) inflammatory and angiogenic responses (local and systemic) to the injury. Red fluorescence was seen within 7 days after transfusion of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine-labelled acetylated low-density lipoprotein (Dil-acLDL)-incorporated OECs, and 1 h after perfusion of the isolated rabbit ear with Ringer-Locke solution containing Dil-acLDL-incorporated OECs, in the injured rabbit ear central artery. After transfusion of 5-bromo-2'-deoxyuridine (BrdU) incorporated autologous OECs, BrdU-positive cells appeared in the injured artery intima at day 3 and were present in the rescued artery endothelium at day 28. The OECs, ranging from 5%-15% of vascular smooth muscle cells (VSMCs), and the OEC-conditioned medium (5-15%) both inhibited VSMC proliferation and migration in vitro and regulated the arrangement of VSMCs. The VSMCs were helpful for OECs to form tubes in vitro. CONCLUSION: Circulating OECs participate in re-endothelialization directly and inhibit VSMC migration and proliferation by a paracrine pathway; transfusion of large numbers of autologous OECs soon after vascular injury may prevent neointima formation.

Lipid soluble smoke particles upregulate endothelin receptors in rat basilar artery.

The present study examines the effect of dimethylsulphoxide-soluble particles (DSP) from cigarette smoke on endothelin (ET) receptors in the basilar artery. The contractile responses to ET-1 (ET(A) and ET(B) receptors agonist) and sarafotoxin 6c (ET(B) receptor agonist) were studied using a sensitive myograph. The mRNA levels of ET receptors were determined with real-time PCR, while the protein level was evaluated by immunohistochemistry. The results showed that a DSP concentration of 0.4 microl/ml increased the contractile responses induced by sarafotoxin 6c and ET-1 and the mRNA and protein levels of the ET receptors. Inhibitor SB203580 (a p38 inhibitor), staurosporine (a PKC inhibitor) or wedelolactone (a NF-kappaB inhibitor) attenuated the elevated sarafotoxin 6c-induced contraction, the increased mRNA expression and protein levels of the ET(B) receptor induced by DSP. The effects on the ET(A) receptor induced by DSP 0.4 microl/ml were inhibited by co-incubation with PD98059 (an ERK1/2 inhibitor) or SP600125 (a JNK inhibitor) and were further enhanced by SB203580. The results indicate that DSP 0.4 microl/ml upregulates the ET(B) receptor of basilar arterial smooth muscle cells via activation of the p38 pathway and transcriptional factor NF-kappaB, while also upregulating the ET(A) receptor via activation of the ERK1/2 and JNK pathways. Additionally, the p38 pathway seems to be involved in the feedback regulation of the ET(A) receptor.

Experimental diabetes mellitus down-regulates large-conductance Ca2+-activated K+ channels in cerebral artery smooth muscle and alters functional conductance.

Cerebral vascular dysfunction and associated vascular complications often develop over time in type-2 diabetes, but the underlying mechanisms are not wholly understood. The aim of the present study was to investigate whether large-conductance Ca(2+)-activated K(+) (BKCa) channels in cerebral artery smooth muscle cells (CASMCs) were impaired in experimental model of type-2 diabetes, and the changes could account for cerebral vascular complication in type-2 diabetes. Sprague-Dawley rats were fed with high fat and glucose diet for 8 weeks and then injected with streptozotocin (STZ/30 mg/kg i.p.). Three months after injection of STZ, the alterations of BKCa channels were assessed by using multi-myograph system, patch-clamp, RT-PCR and Western blot. Our results show that the model is characterized by insulin resistance, hyperglycaemia, hyperlipidemia and moderate hypertension, which resembles the clinical manifestation of patients with typre-2 diabetes. Inhibition of BKCa channels with 1 mM tetraethylammonium (TEA) or 1 microM paxilline (PAX) causes smaller constriction in type-2 diabetic cerebral basilar arteries than control arteries. The contractile efficacy of 5-Hydroxytryptamine (5-HT) is substantially reduced by TEA or PAX pretreatment in control > diabetic basilar artery rings. The response to 5-HT in diabetic basilar artery rings is higher than that of control artery rings after activation of BKCa channels with NS1619. The whole-cell K(+) currents are significantly decreased in type-2 diabetic CASMCs compared to control, and the sensitivity of BKCa channels to voltage, the specific inhibitor and opener are all diminished in diabetic CASMCs. The expression of BKCa channel beta1, but not alpha-subunits is markedly reduced at both of mRNA and protein levels in endothelial-denudated cerebral arteries. In conclusion, type-2 diabetes downregulates BKCa channel beta1-subunits in CASMCs, resulting in reduced activity of BKCa channel, increased vascular tone and blood pressure, thereby contributing to cerebral vascular complication in type-2 diabetes.

The influence of chirality, physicochemical properties, and permeation enhancers on the transdermal permeation of amlodipine across rat skin.

PURPOSE: This study was aimed at investigating the possible relationship between the physical properties and the permeation of S-amlodipine and RS-amlodipine and studying the possible enantioselectivity of permeation of amlodipine in the presence and absence of enhancers, such as terpene enhancers and ethanol. METHOD: The solubility of S-amlodipine and RS-amlodipine was measured using the shake-flask method. The thermodynamic properties were investigated by differential scanning calorimetry (DSC). The type of racemate amlodipine was investigated by DSC and Fourier transform infrared spectroscopy (FTIR). The permeability of racemate and enantiomers of amlodipine through rat epidermis in vitro was investigated using the modified Franz diffusion cell. RESULTS: The aqueous solubility of S-amlodipine was higher than that of RS-amlodipine. The melting temperature and enthalpy of fusion of S-amlodipine were lower than those of RS-amlodipine. RS-amlodipine was a racemic compound. The permeation of the enantiomers of amlodipine from RS-amlodipine reservoir showed no significant differences in the presence and absence of enhancers, but the permeation of S-amlodipine from S-amlodipine reservoir was significantly higher than that of RS-amlodipine from RS-amlodipine reservoir 30% ethanol, 50% ethanol, and terpene enhancers could not influence the difference in permeation between S-amlodipine and RS-amlodipine, but 75% ethanol could reduce the difference. CONCLUSION: These results suggested that there was no enantioselectivity of the enantiomers of amlodipine from RS-amlodipine reservoir in the presence and absence of enhancers, but the differences in physical properties between S-amlodipine and RS-amlodipine led to the difference in permeation across rat skins.

The effect of insulin in combination with selenium on blood glucose and GLUT4 expression in the cardiac muscle of streptozotocin-induced diabetic rats.

We evaluated the effect of a combination of low doses of insulin (1 U/kg/day) and selenium (180 microg/kg/day) on general physiological parameters and the level of glucose transporter (GLUT4) in the cardiac muscle of streptozotocin-induced diabetic rats. Diabetic rats were treated with insulin, selenium and a combination of insulin and selenium for 4 weeks. The levels of blood glucose and hemoglobin A1c were estimated; the level of the GLUT4 in the cardiac muscle was examined by immunoblotting and immunohistochemistry. Insulin in combination with selenium could significantly lower blood glucose and HbA1c levels and could restore disturbances in GLUT4 level in the cardiac muscle. The treatment with insulin was only partially effective in the restoration of diabetic alterations. We conclude that there was cooperation between insulin and selenium, and that the treatment of diabetic rats with combined doses of insulin and selenium was effective in the control of blood glucose and correction of altered GLUT4 distribution in diabetic rat hearts.

[A method for improving the accuracy and sensitivity of cell membrane chromatography].

OBJECTIVE: To improve the accuracy and sensitivity of cell membrane chromatography (CMC) and evaluate the feasibility of CMC in the study of subtype receptors. METHODS: Plasmids were used to transfer alpha(1B)-AR cDNA into human embryonic kidney 293 (HEK293) cell lines to obtain cell lines stably overexpressing the subtype receptors. HEK293 alpha(1B) cell membrane stationary phase (CMSP) was prepared by immobilizing the cell membrane on silica. The retention time of 9 alpha(1)-adrenoceptor ligands and capacity factors(kappa'(HEK293 alpha1B)) were calculated. The capacity factors of rat liver tissue and primary cultured rat hepatocytes were also calculated for a correlation analysis. RESULTS: The calculated capacity factors (kappa') were positively correlated to the published pKi values. The affinity rank orders were identical. The longest retention of the 9 alpha(1)-adrenoceptor ligands occurred on CMSP prepared with HEK293 alpha(1B) cell lines, while CMSP obtained from rat liver tissue showed the shortest retention of the ligands. CONCLUSION: CMC proves practical in the study of the subtype adrenoceptors. The accuracy and sensitivity of CMC can be improved using HEK293 alpha(1B) cell membrane.

Influence of sodium dodecyl sulfate on swelling, erosion and release behavior of HPMC matrix tablets containing a poorly water-soluble drug.

The effect of sodium dodecyl sulfate (SDS) on the swelling, erosion and release behavior of HPMC matrix tablets was examined. Swelling and erosion of HPMC matrix tablets were determined by measuring the wet and subsequent dry weights of matrices. The rate of uptake of the dissolution medium by the matrix was quantified using a square root relationship whilst the erosion of the polymer was described using the cube root law. The extent of swelling decreased with increasing SDS concentrations in the dissolution medium but the rate of erosion was found to follow a reverse trend. Such phenomena might have been caused by the attractive hydrophobic interaction between HPMC and SDS as demonstrated by the cloud points of the solutions containing both the surfactant and polymer. Release profiles of nimodipine from HPMC tablets in aqueous media containing different concentrations of SDS were finally studied. Increasing SDS concentrations in the medium was shown to accelerate the release of nimodipine from the tablets, possibly due to increasing nimodipine solubility and increasing rate of erosion by increasing SDS concentrations in the dissolution medium.

Frontal analysis of cell-membrane chromatography for determination of drug-alpha(1D) adrenergic receptor affinity.

The aim of the present study was to determine drug-alpha(1D) adrenergic receptor (AR) affinity by frontal analysis of cell-membrane chromatography (CMC). The cell-membrane stationary phase (CMSP) was prepared by immobilizing rat aorta cell membranes on porous silica, and the resulting CMSP was used to determine drug binding affinity to alpha(1D)-AR by frontal analysis. The CMSP of rat aorta was stable and reproducible. Relative binding affinities (dissociation constant, K(d)) were determined by frontal chromatography for prazosin (166.13+/-18.36 nmol), BMY7378 (537.40+/-30.84 nmol), phentolamine (646.92+/-23.17 nmol), 5-methylurapidil (725.66+/-25.48 nmol), oxymetazoline (910.56+/-40.62 nmol) and methoxamine (1299.27+/-51.73 nmol). These results were consistent with the affinity rank order and showed a good correlation with the affinity of the same compounds for the cloned alpha(1D)-AR subtype obtained from radioligand-binding assay. The study demonstrates that frontal analysis of CMC may be used for direct determination of drug-receptor binding interactions, and that CMC is an alternative reliable method to quantitatively study ligand-receptor interactions.

Characterization of calcium signaling pathways in human preadipocytes.

Intracellular free Ca2+ (Ca(i)2+) is an important regulator of many cellular activities; however, Ca2+ signaling is not well studied in human preadipocytes. The purpose of the present study was to characterize Ca2+ signal pathways using a confocal scanning technique and RT-PCR. It was found that spontaneous Ca(i)2+ oscillations were observed in 12.1% preadipocytes, and number of cells with Ca2+ oscillations was increased to 47.9% by 1% fetal bovine serum. Ca(i)2+ oscillations were dependent on Ca2+ entry mainly via stored-operated Ca2+ (SOC) entry. They were suppressed by the SOC entry channel blocker La3+, the phospholipase C (PLC) inhibitor U73122, the inositol trisphosphate receptor (IP3R) blocker 2-amino-ethoxydiphenyl borate, or the sarcoplasmic/endoplasmic reticulum Ca2+ pump (SERCA) inhibitors thapsigargin and cyclopiazonic acid, but not by ryanodine. The IP3R activator thimerosal increased Ca(i)2+ oscillations. In addition, the plasma membrane Ca2+ pump (PMCA) inhibitor carboxyeosin and Na+--Ca2+ exchanger (NCX) inhibitor Ni2+ both suppressed Ca2+ oscillations. RT-PCR revealed that the mRNAs for IP3R1-3, SERCA1,2, NCX3 and PMCA1,3,4, Ca(V)1.2, and TRPC1,4,6, STIM1 and Orai1 (for SOC entry channels) were significant in human preadipocytes. The present study demonstrates that multiple Ca2+ signal pathways are present in human preadipocytes, and provides a basis for investigating how Ca2+ signals regulate biological and physiological activities of human preadipocytes.