Response to Cadmium Toxicity: Orchestration of Polyamines and microRNAs in Maize Plant.

Cadmium (Cd) is a heavy metal that is widely contaminating the environment due to its uses in industries as corrosive reagents, paints, batteries, etc. Cd can easily be absorbed through plant roots and may have serious negative impacts on plant growth. To investigate the mechanisms utilized by plants to cope with Cd toxicity, an experiment was conducted on maize seedlings. We observed that the plant growth and photosynthetic mechanism were negatively influenced during 20 days of Cd stress. The expression levels of ornithine decarboxylase (ORDC) increased in the six seedlings under Cd exposure compared to the control. However, Cd toxicity led to an increase in putrescine (Put) content only on day 15 when compared to the control plants. In fact, with the exception of day 15, the increases in the ORDC transcript levels did not show a direct correlation with the observed increases in Put content. Spermidine and Spermine levels were reduced on day 6 by Cd application, which was parallel with suppressed Spermidine synthase gene. However, an increase in Spermidine and Spermine levels was observed on day 12 along with a significant elevation in Spermidine synthase expression. On day 6, Cd was observed to start accumulating in the root with an increase in the expression of microRNA 528; while on day 15, Cd started to be observed in the shoot part with an increase in microRNA 390 and microRNA 168. These results imply that different miRNAs may regulate polyamines (PAs) in maize under Cd toxicity, suggesting a plant-derived strategy to commit a PAs/miRNA-regulated mechanism/s in different developmental stages (time points) in response to Cd exposure.

Quantification of mitochondrial DNA damage and copy number in circulating blood of patients with systemic sclerosis by a qPCR-based assay

Abstract Background: Although not fully understood, oxidative stress has been implicated in the pathogenesis of different autoimmune diseases such as systemic sclerosis. Accumulating evidence indicates that oxidative stress can induce mitochondrial DNA (mtDNA) damage and variations in mtDNA copy number (mtDNAcn). Objective: The aim of this study was to explore mtDNAcn and oxidative DNA damage byproducts in peripheral blood of patients with systemic sclerosis and healthy controls. Methods: Forty six patients with systemic sclerosis and forty nine healthy subjects were studied. Quantitative real-time PCR used to measure the relative mtDNAcn and the oxidative damage (oxidized purines) of each sample. Results: The mean mtDNAcn was lower in patients with systemic sclerosis than in healthy controls whereas the degree of mtDNA damage was significantly higher in cases as compared to controls. Moreover, there was a negative correlation between mtDNAcn and oxidative DNA damage. Study limitations: The lack of simultaneous analysis and quantification of DNA oxidative damage markers in serum or urine of patients with systemic sclerosis and healthy controls. Conclusion: These data suggest that alteration in mtDNAcn and increased oxidative DNA damage may be involved in the pathogenesis of systemic sclerosis.

High-frequency (20 to 40 MHz) acoustic response of liquid-filled nanocapsules.

Liquid-core nanoparticles are promising candidates for targeted ultrasound-controlled therapy, but their acoustic detection remains challenging. High-frequency (20 to 40 MHz) tone burst sequences were implemented with a programmable ultrasound biomicroscope to characterize acoustic response from perfluorooctyl bromide-core nanoparticles with thick poly(lactide-coglycolide) (PLGA) shells. Radio-frequency signals were acquired from flowing solutions of nanoparticles with two different shell-thickness-to-particle-radius ratios, solid PLGA nanoparticles, and latex nanobeads (linear controls). Normalized fundamental (20 MHz) and second-harmonic power spectral density (PSD) increased with particle concentration and was highest for the thinnest shelled particles. The second- harmonic PSD was detectable from the nanoparticles for peak rarefactional pressures (PRP) from 0.97 to 2.01 MPa at 23 cycles and for tone bursts from 11 to 23 cycles at 2.01 MPa. Their second-harmonic¿to¿fundamental ratio increased as a function of PRP and number of cycles. Within the same PRP and cycle ranges, the second-harmonic¿to¿fundamental ratios from matched concentration solutions of latex nanobeads and solid PLGA nanoparticles was more weakly detectable but also increased with PRP and number of cycles. Nanoparticles were detectable under flow conditions in vitro using the contrast agent mode of a high-frequency commercial scanner. These results characterize linear acoustic response from the nanoparticles (20 to 40 MHz) and demonstrate potential for their highfrequency detection.

Clinical trial of adjunctive celecoxib treatment in patients with major depression: a double blind and placebo controlled trial.

BACKGROUND: The pathophysiology of depression is associated with the hyperactivity of immune inflammatory responses. Cyclooxygenase-2 inhibitors such as celecoxib reduce the production of pro-inflammatory cytokines. The purpose of the present investigation was to assess the efficacy of celecoxib as an adjuvant agent in the treatment of major depression in a six-week double blind and placebo controlled trial. METHODS: Forty adult outpatients who met the DSM-IV-TR criteria for major depression participated in the trial. Patients have a baseline Hamilton Rating Scale for Depression score of at least 18. Patients were allocated in a random fashion: 20 to fluoxetine 40 mg/day plus celecoxib 400 mg/day (200 mg bid) (morning and evening) and 20 to fluoxetine 40 mg/day plus placebo. Patients were assessed by a psychiatrist at baseline and after 1, 2, 4, and 6 weeks after the medication started. RESULTS: Although both protocols significantly decreased the score of Hamilton Rating Scale for Depression over the trial period, the combination of fluoxetine and celecoxib showed a significant superiority over fluoxetine alone in the treatment of symptoms of major depression. There were no significant differences in the two groups in terms of observed side effects. CONCLUSION: The results of this study suggest that celecoxib may be an effective adjuvant agent in the management of patients with major depression and anti-inflammatory therapies should be further investigated.