Synthesis of Five-Membered Cyclic Guanidines via Cascade [3 + 2] Cycloaddition of α-Haloamides with Organo-cyanamides.

The convenient preparation of N2-unprotected five-membered cyclic guanidines was achieved through a cascade [3 + 2] cycloaddition between organo-cyanamides and α-haloamides under mild conditions in good to excellent yields (up to 99%). The corresponding cyclic guanidines could be easily transformed into hydantoins via hydrolysis.

T-2 toxin cytotoxicity mediated by directly perturbing mitochondria in human gastric epithelium GES-1 cells.

T-2 toxin is one of the most toxic trichothecenes and harmful to human health and animal husbandry. The mechanism underlying its growth suppression remains unclear, especially for mitochondrial damage in human gastric epithelial cells. In the present study, we investigated cell death caused by T-2 toxin in a human gastric epithelial cell line (GES-1) and the possible mechanism of T-2-induced cytotoxicity. T-2 strongly reduced the viability of GES-1 cells in a time- and dose-dependent manner within a small range of concentrations. However, when the concentrations of T-2 were >40 nM, there was no concentration dependence, only time dependence. Moreover, T-2 induced apoptosis, with the activation of caspase-3 in GES-1 and mitochondrial membrane potential (MMP) decrease and cytochrome c release. T-2 also resulted in the accumulation of reactive oxygen species (ROS) and DNA damage with a positive signal of p-H2A.X in GES-1 cells. While T-2 caused a MMP decrease, DNA damage and cell death were not blocked by pretreatment with 3 mM glutathione (GSH), a typical scavenger of ROS. The induction of mitochondrial permeability transition pore (mPTP) regulators voltage-dependent anion channel (VDAC1) and cyclophilin D (CypD) were also observed in T-2-treated cells. Interestingly, cyclosporine A (CsA), a CypD inhibitor, significantly reversed the drop in MMP and the DNA damage, as well as ROS accumulation caused by T-2. Additionally, GES-1 cell death could also be protected to some extent by 4, 4'-diisothiocyanatostilbene-2, 2'-disulfonic acid (DIDS), an inhibitor of VDAC1, especially the combination of CsA and DIDS, and 3 mM GSH could further enhance the effect of CsA + DIDS on cell viability. In conclusion, our present findings indicate that the T-2 induced MMP decrease, DNA damage and cell death, as well as ROS accumulation in GES-1 cells, starts with T-2 directly perturbing the mitochondria triggering ROS generation by acting on CypD and VDAC1. This study presents a new viewpoint for evaluating the toxicity of T-2 toxin.

Synthesis of Sulfamate-Fused 2-Aminopyrroles via an Isocyanide-Based Three Component [1+2+2] Annulation.

An efficient preparation of sulfamate-fused 2-aminopyrroles was achieved through an isocyanide-based three-component [1+2+2] annulation of isocyanides, dialkyl acetylenedicarboxylates, and sulfamate-derived cyclic imines in good to excellent yields (up to 99 %). This reaction proceeds smoothly without any activation or modification of substances under neutral and metal-free conditions. The reaction could also be conveniently performed on a gram scale.

Synthesis of spirobarbiturate-pyrrolidinones via a domino aza-Michael/SN2 cyclization of barbiturate-derived alkenes with N-alkoxy α-haloamides.

A highly efficient domino aza-MIRC (Michael Induced Ring Closure) reaction between barbiturate-derived alkenes and N-alkoxy α-haloamides has been achieved in moderate to excellent yields. This reaction proceeds smoothly under mild conditions via a domino aza-Michael addition/intramolecular SN2 sequence, providing a practical tool in the synthesis of bioactive molecules spirobarbiturate-3-pyrrolidinones.

Curcumin ameliorates insulin signalling pathway in brain of Alzheimer's disease transgenic mice.

Deficits in glucose, impaired insulin signalling and brain insulin resistance are common in the pathogenesis of Alzheimer's disease (AD); therefore, some scholars even called AD type 3 diabetes mellitus. Curcumin can reduce the amyloid pathology in AD. Moreover, it is a well-known fact that curcumin has anti-oxidant and anti-inflammatory properties. However, whether or not curcumin could regulate the insulin signal transduction pathway in AD remains unclear. In this study, we used APPswe/PS1dE9 double transgenic mice as the AD model to investigate the mechanisms and the effects of curcumin on AD. Immunohistochemical (IHC) staining and a western blot analysis were used to test the major proteins in the insulin signal transduction pathway. After the administration of curcumin for 6 months, the results showed that the expression of an insulin receptor (InR) and insulin receptor substrate (IRS)-1 decreased in the hippocampal CA1 area of the APPswe/PS1dE9 double transgenic mice, while the expression of phosphatidylinositol-3 kinase (PI3K), phosphorylated PI3K (p-PI3K), serine-threonine kinase (AKT) and phosphorylated AKT (p-AKT) increased. Among the curcumin groups, the medium-dose group was the most effective one. Thus, we believe that curcumin may be a potential therapeutic agent that can regulate the critical molecules in brain insulin signalling pathways. Furthermore, curcumin could be adopted as one of the AD treatments to improve a patient's learning and memory ability.

[Neuroprotective effect of curcumin to Aß of double transgenic mice with Alzheimer's disease].

OBJECTIVE: To observe the changes in Aß40, Aß42 and ADDLs in brains of 3 month-old APPswe/PS1dE9 double transgenic mice after six-month intervention with curcumin, in order to discuss the neuroprotective effect of curcumin. METHOD: APPswe/PS1dE9dtg mice were randomly divided into the model group, the Rosiglitazone group (10 mg x kg(-1) x d(-1)) and curcumin high (400 mg x kg9-1) x d(-1)), medium (200 mg x kg(-1) x d(-1)) and low (100 mg x kg(-1) x d(-1)) dosage groups, with C57/BL6J mice of the same age and the same background in the normal control group. After 6 months, the immunohistochemical staining (IHC) and the Western blot method were used to observe the changes in positive cell of Aß40, Aß42 and ADDLs in hippocampal CA1 area, their distribution and protein expressions. RESULT: Both of the immunohistochemical staining and the Western blot method showed more positive cell of Aß40, Aß42 and ADDLs in hippocampal CA1 area and higher protein expressions in the model group than the normal group (P < 0.01). IHC showed a lower result in the Rosiglitazone group than the model group (P < 0.05), while Western blot showed a much lower result (P < 0.01). The number of Aß40, Aß42 and ADDLs positive cells and the protein expressions decreased in the curcumin high group, the medium group showed a significant decrease (P < 0.01), and the low dose group also showed reductions in the protein expressions of Aß40 and Aß42. CONCLUSION: The six-month intervention with curcumin can significantly reduce the expressions of hippocampal Aß40, Aß42 and ADDLs in brains of APPswe/PS1dE9 double transgenic mice. Whether curcumin can impact Aß cascade reaction by down-regulating expressions of Aß40, Aß42 and ADDLs and show the neuroprotective effect needs further studies.

[Dynamic effect of curcumin on urine concentration of neuronal thread protein in AD mice].

OBJECTIVE: Through the dynamic detection of the concentration change of the urine Alzheimer-associated neuronal thread protein (AD7C-NTP) in the curcumin treated Alzheimer's disease (AD) model (APP/PS1 double transgenic) mice, the therapeutic effect of curcumin in AD was determined. METHOD: Thirty three-month-old APP /PS1 double transgenic mice were randomly divided into 5 groups, 6 in each group, the model group, rosiglitazone group(10 mg . kg-1 . d-1) , high(400 mg . kg -1 . d-1) , medium(200 mg . kg-1. d-1) and low(100 mg . kg-1 . d-1) dose curcumin groups. Six C57BL/6J mice in the same age and genetic background were used as normal control group. All the 6 groups of mice were intragastrically administered for 6 months. Urine samples were collected on 4 month, 5 month and 6 month after intragastric administration, respectively. The changes of urinary AD7C-NTP concentration were detected by enzyme-linked immunosorbent assay (ELISA). RESULT: The concentration of AD7C-NTP of each group was compared at the same time point, the concentration of model group is higher than normal control group (P <0.05) ; the concentration of other groups is lower than model group. The concentration of high curcumin dose group with 4 months treatment, has no statistical difference compared with model group. The AD7C-NTP concentration of each group was elevated with the age growth, and all concentrations of the treatment groups were lower than the model group at the same period. With the treatment of 4, 5 and 6 months, the concentration of the normal control group has significant difference with the treatment groups(P <0. 01). There have no statistical difference between all the groups with the treatment of 6 months compared with 5 months. CONCLUSION: With the progression of the disease in AD mice, there are fluctuations in urinary AD7C-NTP concentration, the compound curcumin from traditional Chinese medicine can delay the progression of AD.

Spinal cord stimulation for patients with inoperable chronic critical leg ischemia.

BACKGROUND: Because of the prevalence of diabetes, the treatment of diabetic foot is still challenging. Even an exactly proved effective and practical method can't be listed except vascular surgery which is not a long-term way for it. Spinal cord stimulation (SCS) is a very promising option in the treatment algorithm of inoperable chronic critical leg ischemia (CLI). DATA SOURCES: We searched Pubmed database with key words or terms such as "spinal cord stimulation", "ischemic pain" and "limb ischemia" appeared in the last five years. RESULTS: The mechanism of SCS is unclear. Two theories have emerged to interpret the benefits of SCS. Pain relief from SCS can be confirmed by a majority of the studies, while limb salvage and other more ambitious improvements have not come to an agreement. The complications of SCS are not fatal, but most of them are lead migration, lead connection failure, and local infection. CONCLUSIONS: SCS is a safe, promising treatment for patients with inoperable CLI. It is effective in pain reduction compared with traditional medical treatment.

[Comparison of total body irradiation-cyclophosphamide versus busulphan-cyclophosphamide as conditioning regimens for myelogenous leukemia: a meta-analysis].

Total body irradiation combined with cyclophosphamide (TBI/CY) and busulphan combined with cyclophosphamide (BU/CY) are standard conditioning regimens in hematological stem cell transplantation for patients with myelogenous leukemia. This study was aimed to compare the therapeutic efficacy of TBI/CY and BU/CY as conditioning regiment for acute or chronic myelogenous leukemia. The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, CNKI, CBM (Chinese Bio-medicine Database) had been searched for all relevant articles (1999-2007). Comparative studies were carried out on clinical therapeutic effects of TBI/CY and BU/CY including stem cell engraftment, relapse, complications, transplant-related mortality, and disease-free survival. A meta-analysis was performed using Review Manager 4.2 software and funnel plot regression was adopted to assess the publication bias. The results indicated that 2149 articles in English and 46 articles in Chinese were got, and finally 9 clinical trials with total 3039 patients have been assessed. No significantly difference was found in engraftment failure and transplant-related mortality resulting from TBI/CY and BU/CY conditioning regimens, but the incidence of veno-occlusion of liver and hemorrhagic cystitis obviously increased in BU/CY group after transplantation, the acute GVHD, interstitial pneumonia and cataract significantly increased in TBI/CY group. The relapse rate of AML in TBI/CY group was lower than that in BU/CY group, and the rate of long-term disease-free survival of AML patients in TBI/CY group also significantly lower than that in BU/CY group, but the relapse rate of CML in TBI/CY group after transplantation was obviously higher than that in BU/CY group, but there was no difference in longterm disease-free survival rate between the two conditioning regimens mentioned above. It is concluded that the meta-analysis confirms different effects of TBI/CY and BU/CY regimens on myelogenous leukemia transplantation. This result is useful for physicians to select treatment regimens.

[Inducing-apoptosis effect of bortezomib on acute monocytic leukemia cell SHI-1 and its influence on expressions of Bcl2l12, Bcl-2 and Bax genes].

This study was aimed to explore the effect of bortezomib on proliferation and apoptosis of acute monocytic leukemic cells SHI-1 and the function of Bcl-2 gene family including Bcl2l12, Bcl-2 and Bax in its apoptosis. SHI-1 cells were cultured and treated with bortezomib of different concentrations for different time. MTT assay was used to detect the proliferation and apoptosis, Annexin-V staining, mitochondrial transmembrane potential (DeltaPsim) and DNA aga-rose gel electrophoresis were used to investigate apoptosis of SHI-1 cells. RT-PCR was used to analyze the levels of Bcl2l12, Bcl-2 and bax mRNA in SHI-1 cells treated with bortezomib for 0, 6, 12 and 24 hours. The results showed that bortezomib inhibited the proliferation of SHI-1 cells in time-and doze-dependent manners, the IC(50) at 24 and 48 hours were 54.13 nmol/L and 5.45 nmol/L respectively. Bortezomib could induce apoptosis of SHI-1 cells in time-dependent manner, increase expression of Annexin-V positive cells, decrease DeltaPsim of SHI-1 cells and result in DNA fragmentation and morphologic changes of apoptosis. RT-PCR showed that Bcl2l12 mRNA expression was up-regulated, bcl-2 mRNA expression was down-regulated and bax mRNA expression was not changed obviously. It is concluded that bortezomib inhibits the proliferation of SHI-1 and induces apoptosis in which Bcl2l12 and Bcl-2 gene can be ones of the main genes taking part in.