The distance between P680 and QA in Photosystem II determined by ESEEM spectroscopy

AbstractLight induced spin-polarized P680+Q−A radical pairs were studied by two pulse electron spin echo envelope modulation (ESEEM) spectroscopy in the cyanide-treated and Zn-substituted Photosystem II core complexes and in the isolated D1-D2-cyt b559 reaction center complexes reconstituted with dibromoisopropyl-p-benzoquinone. The observed strong out-of phase ESEEM signals were identified as those of the P680+Q−A radical pairs based on the time variation of the transient CW EPR spectra. The shapes of ESEEM spectra were attributed to dipolar D and spin exchange J interactions in the radical pairs. The values of D and J were derived from a sine Fourier transformation and the center-to-center distance between P680 and QA was determined to be 27.2±1.0Å for all three preparations

primary prevention of cardiovascular disease and type 2 diabetes in patients at metabolic risk an endocrine society clinical practice guideline

Objective: The objective was to develop clinical practice guidelines for the primary prevention of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) in patients at metabolic risk. Conclusions: Healthcare providers should incorporate into their practice concrete measures to reduce the risk of developing CVD and T2DM. These include the regular screening and identification of patients at metabolic risk (at higher risk for both CVD and T2DM) with measurement of blood pressure, waist circumference, fasting lipid profile, and fasting glucose. All patients identified as having metabolic risk should undergo 10-yr global risk assessment for either CVD or coronary heart disease. This scoring will determine the targets of therapy for reduction of apolipoprotein B-containing lipoproteins. Careful attention should be given to the treatment of elevated blood pressure to the targets outlined in this guideline. The prothrombotic state associated with metabolic risk should be treated with lifestyle modification measures and in appropriate individuals with low-dose aspirin prophylaxis. Patients with prediabetes (impaired glucose tolerance or impaired fasting glucose) should be screened at 1- to 2-yr intervals for the development of diabetes with either measurement of fasting plasma glucose or a 2-h oral glucose tolerance test. For the prevention of CVD and T2DM, we recommend that priority be given to lifestyle management.Thisincludesantiatherogenicdietarymodification,aprogramofincreasedphysicalactivity, andweightreduction.Effortstopromotelifestylemodificationshouldbeconsideredanimportant component of the medical management of patients to reduce the risk of both CVD and T2DM. (J Clin Endocrinol Metab 93: 3671–3689, 2008

Comparative effectiveness of dipeptidyl peptidase-4 (DPP-4) inhibitors and human glucagon-like peptide-1 (GLP-1) analogue as add-on therapies to sulphonylurea among diabetes patients in the Asia-Pacific region: a systematic review

The prevalence of diabetes mellitus is rising globally, and it induces a substantial public health burden to the healthcare systems. Its optimal control is one of the most significant challenges faced by physicians and policy-makers. Whereas some of the established oral hypoglycaemic drug classes like biguanide, sulphonylureas, thiazolidinediones have been extensively used, the newer agents like dipeptidyl peptidase-4 (DPP-4) inhibitors and the human glucagon-like peptide-1 (GLP-1) analogues have recently emerged as suitable options due to their similar efficacy and favorable side effect profiles. These agents are widely recognized alternatives to the traditional oral hypoglycaemic agents or insulin, especially in conditions where they are contraindicated or unacceptable to patients. Many studies which evaluated their clinical effects, either alone or as add-on agents, were conducted in Western countries. There exist few reviews on their effectiveness in the Asia-Pacific region. The purpose of this systematic review is to address the comparative effectiveness of these new classes of medications as add-on therapies to sulphonylurea drugs among diabetic patients in the Asia-Pacific countries. We conducted a thorough literature search of the MEDLINE and EMBASE from the inception of these databases to August 2013, supplemented by an additional manual search using reference lists from research studies, meta-analyses and review articles as retrieved by the electronic databases. A total of nine randomized controlled trials were identified and described in this article. It was found that DPP-4 inhibitors and GLP-1 analogues were in general effective as add-on therapies to existing sulphonylurea therapies, achieving HbA1c reductions by a magnitude of 0.59–0.90% and 0.77–1.62%, respectively. Few adverse events including hypoglycaemic attacks were reported. Therefore, these two new drug classes represent novel therapies with great potential to be major therapeutic options. Future larger-scale research should be conducted among other Asia-Pacific region to evaluate their efficacy in other ethnic groups

Dynamics of Endoreplication during Drosophila Posterior Scutellar Macrochaete Development

Endoreplication is a variant type of DNA replication, consisting only of alternating G1 and S phases. Many types of Drosophila tissues undergo endoreplication. However, the timing and the extent to which a single endocycling macrochaete undergoes temporally programmed endoreplication during development are unclear. Here, we focused on the dynamics of endoreplication during posterior scutellar (pSC) macrochaete development. Quantitative analyses of C values in shaft cells and socket cells revealed a gradual rise from 8C and 4C at 8 hours after pupal formation (APF) to 72C and 24C at 29 hours APF, respectively. The validity of the values was further confirmed by the measurement of DNA content with a confocal laser microscope. BrdU incorporation assays demonstrated that shaft cells undergo four rounds of endoreplication from 18 to 29.5 hours APF. In contrast, socket cells undergo two rounds of endoreplication during the same period. Statistical analyses showed that the theoretical C values, based on BrdU assays, nearly coincide with the actually measured C values in socket cells, but not in shaft cells after 22 hours APF. These analyses suggest that socket cells undergo two rounds of endoreplication. However, the mechanism of endoreplication in the shaft cells may change from 22 hours APF, suggesting the possibility that shaft cells undergo two or four rounds of endoreplication during the periods. We also found that the timing of endoreplication differs, depending on the type of macrochaete. Moreover, endocycling in shaft cells of both the left and right sides of pSC bristle lineages occurs in the same pattern, indicating that the process is synchronized for specific types of macrochaete. Our findings suggest that endocycling in macrochaete cell lineages can be a model for understanding mechanisms of endoreplication at the single-cell level

The chemopreventive polyphenol Curcumin prevents hematogenous breast cancer metastases in immunodeficient mice

Dissemination of metastatic cells probably occurs long before diagnosis of the primary tumor. Metastasis during early phases of carcinogenesis in high risk patients is therefore a potential prevention target. The plant polyphenol Curcumin has been proposed for dietary prevention of cancer. We therefore examined its effects on the human breast cancer cell line MDA-MB-231 in vitro and in a mouse metastasis model. Curcumin strongly induces apoptosis in MDA- MB- 231 cells in correlation with reduced activation of the survival pathway NF kappa B, as a consequence of diminished I kappa B and p65 phosphorylation. Curcumin also reduces the expression of major matrix metalloproteinases (MMPs) due to reduced NF kappa B activity and transcriptional downregulation of AP-1. NF kappa B/p65 silencing is sufficient to downregulate c-jun and MMP expression. Reduced NF kappa B/AP-1 activity and MMP expression lead to diminished invasion through a reconstituted basement membrane and to a significantly lower number of lung metastases in immunodeficient mice after intercardiac injection of 231 cells (p=0.0035). 68% of Curcumin treated but only 17% of untreated animals showed no or very few lung metastases, most likely as a consequence of down-regulation of NF kappa B/AP-1 dependent MMP expression and direct apoptotic effects on circulating tumor cells but not on established metastases. Dietary chemoprevention of metastases appears therefore feasible. Copyright (c) 2007 S. Karger AG, Basel