1.The slow S to M rise of chlorophyll a fluorescence reflects transition from state 2 to state 1 in the green alga Chlamydomonas reinhardtii.
Kodru S1, Malavath T, Devadasu E, Nellaepalli S, Stirbet A, Subramanyam R, Govindjee. Photosynth Res. 2015 Aug;125(1-2):219-31. doi: 10.1007/s11120-015-0084-2. Epub 2015 Feb 8.
The green alga Chlamydomonas (C.) reinhardtii is a model organism for photosynthesis research. State transitions regulate redistribution of excitation energy between photosystem I (PS I) and photosystem II (PS II) to provide balanced photosynthesis. Chlorophyll (Chl) a fluorescence induction (the so-called OJIPSMT transient) is a signature of several photosynthetic reactions. Here, we show that the slow (seconds to minutes) S to M fluorescence rise is reduced or absent in the stt7 mutant (which is locked in state 1) in C. reinhardtii. This suggests that the SM rise in wild type C. reinhardtii may be due to state 2 (low fluorescence state; larger antenna in PS I) to state 1 (high fluorescence state; larger antenna in PS II) transition, and thus, it can be used as an efficient and quick method to monitor state transitions in algae, as has already been shown in cyanobacteria (Papageorgiou et al. 1999, 2007; Kaňa et al. 2012). We also discuss our results on the effects of (1) 3-(3,4-dichlorophenyl)-1,4-dimethyl urea, an inhibitor of electron transport; (2) n-propyl gallate, an inhibitor of alternative oxidase (AOX) in mitochondria and of plastid terminal oxidase in chloroplasts; (3) salicylhydroxamic acid, an inhibitor of AOX in mitochondria; and (4) carbonyl cyanide p-trifluoromethoxyphenylhydrazone, an uncoupler of phosphorylation, which dissipates proton gradient across membranes.
2.Anti-androgenic activities of diuron and its metabolites in male Nile tilapia (Oreochromis niloticus).
Pereira TS1, Boscolo CN1, Silva DG2, Batlouni SR3, Schlenk D4, Almeida EA5. Aquat Toxicol. 2015 Jul;164:10-5. doi: 10.1016/j.aquatox.2015.04.013. Epub 2015 Apr 13.
Diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is a widely used herbicide which has been frequently detected in surface waters throughout the world. In vivo bioassay guided fractionation studies indicated that diuron may have estrogenic activity augmented by biotransformation. This study evaluated the effects of diuron and three of its metabolites on plasma hormone concentrations and spermatogenesis of the freshwater fish Nile tilapia (Oreochromis niloticus). Sexually mature male fish were exposed for 25 days to diuron, as well to its metabolites 3,4-dichloroaniline (DCA), 3,4-dichlorophenylurea (DCPU) and 3,4-dichlorophenyl-N-methylurea (DCPMU), at concentrations of 200ng/L. Testosterone levels were decreased by diuron, but had limited effects on gonadal histology. Diuron metabolites, however, caused significant decreases in testosterone and in 11-ketotestosterone, gonadosomatic index, diameter of seminiferous tubules and in the mean percentages of germ cells (spermatids and spermatozoa).
3.New urea and thiourea derivatives of piperazine doped with febuxostat: synthesis and evaluation of anti-TMV and antimicrobial activities.
Krishna Reddy RC1, Rasheed S1, Subba Rao D1, Adam S2, Venkata Rami Reddy Y1, Raju CN1. ScientificWorldJournal. 2013 Dec 26;2013:682603. doi: 10.1155/2013/682603. eCollection 2013.
A series of new 4-(5-(3-cyano-4-isobutoxyphenyl)-4-methylthiazole-2-carbonyl)-N-(substituted phenyl)piperazine-1-carboxamides 8(a-e)/carbothioamides 8(f-j) were accomplished for biological interest by the simple addition of active functionalized arylisocyanates 7(a-e)/arylisothiocyanates 7(f-j) with 2-isobutoxy-5-(4-methyl-2-(piperazine-1-carbonyl)thiazol-5-yl)benzonitrile (4). Compound 4 was synthesized in high yields (94%) by the condensation reaction of febuxostat (1) with piperazine using a selective reagent such as propylphosphonic anhydride (T3P). Antiviral activity against Tobacco mosaic virus (TMV) and antimicrobial activity of the synthesized compounds were evaluated. Biological data revealed that 4-nitrophenyl substituted urea 8d, and 3-bromophenyl substituted thiourea 8f exhibited promising antiviral activities. Moreover, 4-fluorophenyl substituted urea 8a, 4-nitrophenyl substituted urea 8d, 3-bromophenyl substituted thiourea 8f, and 2,4-dichlorophenyl substituted thiourea 8j exhibited potent antimicrobial activity.
4.Dose and temporal effects on gene expression profiles of urothelial cells from rats exposed to diuron.
Ihlaseh-Catalano SM1, Bailey KA2, Cardoso AP3, Ren H4, Fry RC5, de Camargo JL6, Wolf DC7. Toxicology. 2014 Nov 5;325:21-30. doi: 10.1016/j.tox.2014.08.005. Epub 2014 Aug 23.
Diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is a substituted urea herbicide that at high dietary levels (2500 ppm) induces rat urinary bladder hyperplasia after 20 weeks of exposure and neoplasia after 2 years. The effects on the urothelium after short-term exposure have not been described. The present 7-day study evaluated the dose-dependency of urothelial alterations in the urinary bladder using light microscopy, scanning electron microscopy, and genome-wide transcriptional profiling. Male Wistar rats were fed 0, 125, 500, 2500 ppm diuron for 7 days. The urinary bladder and isolated urothelial cells of these animals were processed for microscopic examination and gene expression profiling, respectively. No significant treatment-related morphologic effects were observed. The number of differentially expressed genes (DEGs) in the exposed groups increased with diuron levels. Diuron-altered genes involved in cell-to-cell interactions and tissue organization were identified in all treatment groups.