Inhibition of chlorophyll synthesis inHordeum vulgare by 3-amino 2,3-dihydrobenzoic acid (gabaculin)

Gabaculin (3-amino 2,3-dihydrobenzoic acid) is shown to be a very potent inhibitor of chlorophyll formation inHordeum vulgate. Exposure of leaf segments to 30/M gabaculin results in an 80% inhibition of chlorophyll synthesis, and this is paralleled by a decrease in carotenoid. Dual-inhibitor studies with dioxoheptanoic acid, which is an inhibitor of inolaevulinic acid dehydratase, show that gabaculin inhibits an earlier step than dioxoheptanoic acid and affects -aminolaevulinic acid synthesis rather than its subsequent metabolism.     

Discovery of 7-(3-(piperazin-1-yl)phenyl)pyrrolo[2,1-f][1,2,4]triazin-4-amine derivatives as highly potent and selective PI3Kδ inhibitors

As demonstrated in preclinical animal models, the disruption of PI3Kδ expression or its activity leads to a decrease in inflammatory and immune responses. Therefore, inhibition of PI3Kδ may provide an alternative treatment for autoimmune diseases, such as RA, SLE, and respiratory ailments. Herein, we disclose the identification of 7-(3-(piperazin-1-yl)phenyl)pyrrolo[2,1-f][1,2,4]triazin-4-amine derivatives as highly potent, selective and orally bioavailable PI3Kδ inhibitors. The lead compound demonstrated efficacy in an in vivo mouse KLH model.     

Effects of DDT on photosynthetic electron flow in Secale species

Following a survey of a range of varieties of rye, mainly Secale cereale, for reaction to DDT, the mode of action of the pesticide in a susceptible variety was studied. Two sites of interaction of DDT with the photosynthetic electron transport chain were demonstrated. The first site of inhibition was on the oxidizing side of photosystem 2, between the sites of electron donation from diphenylcarbazide at pH 6.0 and pH 8.0 in Tris-washed chloroplasts. The second site of DDT inhibition was in the intermediate electron transport chain, and was demonstrated by using dichlorophenol-indophenol and phenyldiamines as electron donors in chloroplasts where electron flow from photosystem 2 was inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea. The sites are distinct from those characteristic of herbicides which affect photosynthetic electron flow.     

Methylation of HOXA9 and ISL1 Predicts Patient Outcome in High-Grade Non-Invasive Bladder Cancer

Introduction

Inappropriate DNA methylation is frequently associated with human tumour development, and in specific cases, is associated with clinical outcomes. Previous reports of DNA methylation in low/intermediate grade non-muscle invasive bladder cancer (NMIBC) have suggested that specific patterns of DNA methylation may have a role as diagnostic or prognostic biomarkers. In view of the aggressive and clinically unpredictable nature of high-grade (HG) NMIBC, and the current shortage of the preferred treatment option (Bacillus:Calmette-Guerin), novel methylation analyses may similarly reveal biomarkers of disease outcome that could risk-stratify patients and guide clinical management at initial diagnosis.

Methods

Promoter-associated CpG island methylation was determined in primary tumour tissue of 36 initial presentation high-grade NMIBCs, 12 low/intermediate-grade NMIBCs and 3 normal bladder controls. The genes HOXA9, ISL1, NKX6-2, SPAG6, ZIC1 and ZNF154 were selected for investigation on the basis of previous reports and/or prognostic utility in low/intermediate-grade NMIBC. Methylation was determined by Pyrosequencing of sodium-bisulphite converted DNA, and then correlated with gene expression using RT-qPCR. Methylation was additionally correlated with tumour behaviour, including tumour recurrence and progression to muscle invasive bladder cancer or metastases.

Results

The ISL1 genes’ promoter-associated island was more frequently methylated in recurrent and progressive high-grade tumours than their non-recurrent counterparts (60.0% vs. 18.2%, p = 0.008). ISL1 and HOXA9 showed significantly higher mean methylation in recurrent and progressive tumours compared to non-recurrent tumours (43.3% vs. 20.9%, p = 0.016 and 34.5% vs 17.6%, p = 0.017, respectively). Concurrent ISL1/HOXA9 methylation in HG-NMIBC reliably predicted tumour recurrence and progression within one year (Positive Predictive Value 91.7%), and was associated with disease-specific mortality (DSM).

Conclusions

In this study we report methylation differences and similarities between clinical sub-types of high-grade NMIBC. We report the potential ability of methylation biomarkers, at initial diagnosis, to predict tumour recurrence and progression within one year of diagnosis. We found that specific biomarkers reliably predict disease outcome and therefore may help guide patient treatment despite the unpredictable clinical course and heterogeneity of high-grade NMIBC. Further investigation is required, including validation in a larger patient cohort, to confirm the clinical utility of methylation biomarkers in high-grade NMIBC.     

What do changes in prematch vs. postmatch, 1, 2, and 3 days postmatch body weight tell us about fluid status in English Premiership rugby union players?

This study investigated changes in body weight pre and postmatch and 1, 2, and 3 days postmatch. Thirty-six players contracted to an English Premiership rugby union club had their pre and postmatch body weight and 1, 2, and 3 day postmatch body weight recorded across 14 matches played (10 at home and 4 away) during the official 2003-2004 professional rugby union season, representing a total of 262 player appearances. Body weight was recorded using a set of calibrated Seca digital scales with players wearing underwear only and toweled dry of all sweat (postmatch). Players were allowed to ingest fluid ad libitum throughout each match. A number of players recorded pre to postmatch reductions of body weight of >2% with some as high as 4.9%. Significant position-specific mean reductions in prematch to postmatch body weight (±SD) were found for both forwards (1.94 ± 0.14 kg) and backs (1.04 ± 0.17 kg). The mean gain in postmatch to 1-day postmatch body weight was significant for forwards (1.40 ± 0.27 kg) but not for backs (0.76 ± 0.30 kg). There were no significant mean differences between prematch and 2 or 3 days postmatch body weight for either forwards or backs. Forwards on average lost a significantly greater proportion of their weight pre to postmatch than backs (p = 0.005). Forwards were on average 99.5% of the prematch weight at 1 day postmatch, whereas backs were 99.7% (p = 0.598). Forwards were 99.6% of their prematch weight at 3 days postmatch, whereas backs were 100.4% (p = 0.035). Changes in fluid status can be effectively monitored by recording changes in body weight and is useful where players are undertaking training sessions within 1, 2, or 3 days after their last match as a measure of rehydration status.     

Amino acid sequence of a ferredoxin from Rhodymenia palmata, a red alga in the florideophyceae

The amino acid sequence of a [2Fe-2S] ferredoxin from a red alga, Rhodymenia palmata in the family Florideophyceae, was determined by conventional methods. The ferredoxin is composed of 97 amino acid residues having five cysteines, but lacking methionine and tryptophan. It possesses a number of structural features of particular interest. The amino acid sequence is compared with those previously determined for ferredoxins from two red algae in the family Bangiophyceae. Conclusions from a comparison of the structures, by noting features such as the presence of gaps in the sequences and by constructing a phylogenetic tree, were consistent with the proposed taxonomic relationship among these algae.     

Plasma lipid profiling across species for the identification of optimal animal models of human dyslipidemia

In an attempt to understand the applicability of various animal models to dyslipidemia in humans and to identify improved preclinical models for target discovery and validation for dyslipidemia, we measured comprehensive plasma lipid profiles in 24 models. These included five mouse strains, six other nonprimate species, and four nonhuman primate (NHP) species, and both healthy animals and animals with metabolic disorders. Dyslipidemic humans were assessed by the same measures. Plasma lipoprotein profiles, eight major plasma lipid fractions, and FA compositions within these lipid fractions were compared both qualitatively and quantitatively across the species. Given the importance of statins in decreasing plasma low-density lipoprotein cholesterol for treatment of dyslipidemia in humans, the responses of these measures to simvastatin treatment were also assessed for each species and compared with dyslipidemic humans. NHPs, followed by dog, were the models that demonstrated closest overall match to dyslipidemic humans. For the subset of the dyslipidemic population with high plasma triglyceride levels, the data also pointed to hamster and db/db mouse as representative models for practical use in target validation. Most traditional models, including rabbit, Zucker diabetic fatty rat, and the majority of mouse models, did not demonstrate overall similarity to dyslipidemic humans in this study.     

In Vitro and In Vivo Prostate Cancer Metastasis and Chemoresistance Can Be Modulated by Expression of either CD44 or CD147

CD44 and CD147 are associated with cancer metastasis and progression. Our purpose in the study was to investigate the effects of down-regulation of CD44 or CD147 on the metastatic ability of prostate cancer (CaP) cells, their docetaxel (DTX) responsiveness and potential mechanisms involved in vitro and in vivo. CD44 and CD147 were knocked down (KD) in PC-3M-luc CaP cells using short hairpin RNA (shRNA). Expression of CD44, CD147, MRP2 (multi-drug resistance protein-2) and MCT4 (monocarboxylate tranporter-4) was evaluated using immunofluorescence and Western blotting. The DTX dose-response and proliferation was measured by MTT and colony assays, respectively. The invasive potential was assessed using a matrigel chamber assay. Signal transduction proteins in PI3K/Akt and MAPK/Erk pathways were assessed by Western blotting. An in vivo subcutaneous (s.c.) xenograft model was established to assess CaP tumorigenecity, lymph node metastases and DTX response. Our results indicated that KD of CD44 or CD147 decreased MCT4 and MRP2 expression, reduced CaP proliferation and invasive potential and enhanced DTX sensitivity; and KD of CD44 or CD147 down-regulated p-Akt and p-Erk, the main signal modulators associated with cell growth and survival. In vivo, CD44 or CD147-KD PC-3M-luc xenografts displayed suppressed tumor growth with increased DTX responsiveness compared to control xenografts. Both CD44 and CD147 enhance metastatic capacity and chemoresistance of CaP cells, potentially mediated by activation of the PI3K and MAPK pathways. Selective targeting of CD44/CD147 alone or combined with DTX may limit CaP metastasis and increase chemosensitivity, with promise for future CaP treatment.