Therapeutic potential of statins and the induction of heme oxygenase-1 in preeclampsia

Heme oxygenase (Hmox) is an endogenous system that offers protection against placental cytotoxic damage associated with preeclampsia. The Hmox1/carbon monoxide (CO) pathway inhibits soluble Flt-1 (sFlt-1) and soluble Endoglin (sEng). More importantly, statins induce Hmox1 and suppress the release of sFlt-1 and sEng; thus, statins and Hmox1 activators are potential novel therapeutic agents for treating preeclampsia. The contribution of the Hmox system to the pathogenesis of preeclampsia has been further indicated by the incidence of preeclampsia being reduced by a third in smokers, who had reduced levels of circulating sFlt-1. Interestingly, preeclamptic women exhale less CO compared with women with healthy pregnancies. Hmox1 is reduced prior to the increase in sFlt-1 as Hmox1 mRNA expression in the trophoblast is decreased in the first trimester in women who go on to develop preeclampsia. Induction of Hmox1 or exposure to CO or bilirubin has been shown to inhibit the release of sFlt-1 and sEng in animal models of preeclampsia. The functional benefit of statins and Hmox1 induction in women with preeclampsia is valid not only because they inhibit sFlt-1 release, but also because statins and Hmox1 are associated with anti-apoptotic, anti-inflammatory, and anti-oxidant properties. The StAmP trial is the first randomized control trial (RCT) evaluating the use of pravastatin to ameliorate severe preeclampsia. This proof-of-concept study will pave the way for future global RCT, the success of which will greatly contribute to achieving the United Nations Millennium Development Goals (MDG4 and MDG5) and offering an affordable and easily accessible therapy for preeclampsia. © 2014 The Authors.

Carbon nanotube-supported metal catalysts for NOx reduction using hydrocarbon reductants. Part 1:catalyst preparation, characterization and NOx reduction characteristics

A dual catalyst system for the Selective Catalytic Reduction of NOx with hydrocarbons (HC-SCR), including distinct low and high temperature formulations, is proposed as a means to abate NOx emissions from diesel engines. Given that satisfactory high temperature HC-SCR catalysts are already available, this work focuses on the development of an improved low temperature formulation. Pt supported on multiwalled carbon nantubes (MWCNTs) was found to exhibit superior NOx reduction activity in comparison with Pt/Al2O3, while the MWCNT support displayed a higher resistance to oxidation than activated carbon. Refluxing the MWCNT support in a 1:1 mixture of H2SO4 and HNO3 prior to the metal deposition step proved to be beneficial for the metal dispersion and the NOx reduction performance of the resulting catalysts. This support effect is ascribed to the increased Brønsted acidity of the acid-treated MWCNTs, which in turn enhances the partial oxidation of the hydrocarbon reductant. Further improvements in the HC-SCR performance of MWCNT-based formulations were achieved using a 3:1 Pt–Rh alloy as the supported phase.

On the active site in H3PW12O40/SiO2 catalysts for fine chemical synthesis

The surface environment and structural evolution of silica supported phosphotungstic acid (H3PW12O40) catalysts have been investigated as a function of acid loading. H3PW12O40 clusters are deposited intact upon the silica surface, adopting a Stranksi-Krastanov growth mode forming a two-dimensional adlayer which saturates at 45wt% acid. Intimate contact with the silica support perturbs the local chemical environment of three tungstate centres, which become inequivalent with those in the remaining cluster, suggesting an adsorption mode involving three terminal W==O groups. Above the monolayer, H3PW12O40 clusters form three-dimensional crystallites with physico-chemical properties indistinguishable from those in the bulk heteropoly acid. These H3PW12O40/SiO2 materials are efficient for the solventless isomerisation of α-pinene under mild reaction conditions. Activity scales directly with the number of accessible perturbed tungstate sites at the silica interface; these are the active species.

A comparison of the apoptotic and cytotoxic effects of hexanedione derivatives on human non-neuronal lines and the neuroblastoma line SH-SY5Y

The effects of the alpha-diketone derivatives 2,3- and 3,4-hexanediones were investigated in three non-neuronal cell lines (MCF7, HepG2 and CaCo-2) as well as in the neuroblastoma line, SH-SY5Y. The MTT reduction assay was employed to determine the necrotic effects of the alpha-diketones and the neurotoxin 2,5-hexanedione over 4, 24 and 48 hr exposures. Flow cytometry was also used to study the effects of the three isomers on the cell cycle of the SH-SY5Y line only. With 2,5-hexanedione, the mean MTT IC50 decreased more than 10-fold from 4 to 48 hr. The toxicities of both alpha-diketones were similar, with a more than 18-fold increase in sensitivity of the SH-SY5Y at 24 hr compared to that of 4 hr. With flow cytometry at 48 hr, SH-SY5Y apoptosis with 2,5-hexanedione rose throughout the concentration range evaluated (0-30 mM) while 2,3- and 3,4-hexanediones showed apoptosis over the concentration range 1-1.6 mM, with 3,4-hexanedione being the more potent compared to the 2,3-isomer. At 1.6 mM nearly all the cells had entered apoptosis in the presence of the 3,4-isomer, (94.9 ± 1.4%) but only 57.5 ±4.1% of the 2,3-isomer-treated cells had reached that stage. The 2,3-and 3,4-isomers in diets alone may not pose a serious threat to human health. Further studies may be necessary to evaluate the effects of other dietary components on their toxicity. These alpha-diketones also display a degree of toxic selectivity towards neuroblastoma cells, which may have therapeutic implications.

The role of zinc in the anti-tumour and anti-cachectic activity of D-myo-inositol 1,2,6-triphosphate

Background: D-myo-inositol-1,2,6-triphosphate (a-trinositol, AT) is a polyanionic molecule capable of chelating divalent metal ions with anti-tumour and anti-cachectic activity in a murine model. Methods: To investigate the role of zinc in this process, mice bearing cachexia-inducing MAC16 tumour were treated with AT, with or without concomitant administration of ZnSO4. Results: At a dose of 40mgkg-1, AT effectively attenuated both weight loss and growth of the MAC16 tumour, and both effects were attenuated by co-administration of Zn2+. The concentration of zinc in gastrocnemius muscle increased with increasing weight loss, whereas administration of AT decreased the levels of zinc in plasma, skeletal muscle and tumour, which were restored back to control values after administration of ZnSO4. Conclusion: These results suggest that zinc is important in both tumour growth and cachexia in this animal model.

Dapagliflozin add-on to metformin in type 2 diabetes inadequately controlled with metformin:a randomized, double-blind, placebo-controlled 102-week trial

Background: Management of type 2 diabetes with metformin often does not provide adequate glycemic control, thereby necessitating add-on treatment. In a 24-week clinical trial, dapagliflozin, an investigational sodium glucose cotransporter 2 inhibitor, improved glycemic control in patients inadequately controlled with metformin. The present study is an extension that was undertaken to evaluate dapagliflozin as long-term therapy in this population.Methods: This was a long-term extension (total 102 weeks) of a 24-week phase 3, multicenter, randomized, placebo-controlled, double-blind, parallel-group trial. Patients were randomly assigned (1:1:1:1) to blinded daily treatment (placebo, or dapagliflozin 2.5 to 5, or 10 mg) plus open-label metformin (=1,500 mg). The previously published primary endpoint was change from baseline in glycated hemoglobin (HbA1c) at 24 weeks. This paper reports the follow-up to week 102, with analysis of covariance model performed at 24 weeks with last observation carried forward; a repeated measures analysis was utilized to evaluate changes from baseline in HbA1c, fasting plasma glucose (FPG), and weight.Results: A total of 546 patients were randomized to 1 of the 4 treatments. The completion rate for the 78-week double-blind extension period was lower for the placebo group (63.5%) than for the dapagliflozin groups (68.3% to 79.8%). At week 102, mean changes from baseline HbA1c (8.06%) were +0.02% for placebo compared with -0.48% (P = 0.0008), -0.58% (P

Efficacy and safety of dapagliflozin monotherapy in people with Type 2 diabetes:a randomized double-blind placebo-controlled 102-week trial

Aims: To assess initial pharmacotherapy of Type 2 diabetes with the sodium-glucose cotransporter-2 inhibitor dapagliflozin. Methods: This double-blind, placebo-controlled trial, randomly allocated people with Type 2 diabetes aged 18-77 years and inadequate glycaemic control on diet and exercise [HbA1c 53-86 mmol/mol (7.0-10.0%)] to receive placebo (n = 75) or dapagliflozin monotherapy 2.5 mg (n = 65), 5 mg (n = 64) or 10 mg (n = 70) once daily in the morning. After 24 weeks, low-dose double-blind metformin 500 mg/day was added to the placebo group regimen (placebo+low-dose metformin group). Changes in HbA1c level, fasting plasma glucose and body weight, as well as adverse events, were assessed over 102 weeks. Results: Of the 274 participants randomized, 167 completed the study (60.9%). At 102 weeks, significant differences vs placebo+low-dose metformin with dapagliflozin 5 and 10 mg were observed for HbA1c (-5.8 mmol/mol [-0.53%], P = 0.018; and -4.8 mmol/mol [-0.44%], P = 0.048), respectively); and for FPG (-0.69 mmol/L, P = 0.044; and -1.12 mmol/l, P = 0.001, respectively). For body weight, the difference between the dapagliflozin 10-mg group and the placebo+low-dose metformin group was significant (-2.60 kg; P = 0.016). Hypoglycaemic events were uncommon, with rates of 5.3% for placebo+low-dose metformin group and 0-4.6% for the dapagliflozin groups. Genital infections and urinary tract infections were more common in the dapagliflozin groups than in the placebo+low-dose metformin group. Conclusions: Dapagliflozin as monotherapy in treatment-naïve people with early Type 2 diabetes improved glycaemic control and reduced weight without increasing hypoglycaemia over 102 weeks. Dapagliflozin may provide an alternative initial pharmacotherapy in such people.