Induction of epstein-barr virus (EBV) lytic cycle in vitro causes lipid peroxidation, protein oxidation and DNA damage in lymphoblastoid B cell lines

<p>Abstract</p> <p>Background</p> <p>We investigated the oxidative modifications of lipids, proteins and DNA, potential molecular targets of oxidative stress, in two lymphoblastoid cell lines: B95-8 and Raji, after EBV lytic cycle induction. Conjugated dienes level was measured as biomarker of lipid peroxidation. Malondialdehyde adduct and protein carbonyl levels, as well as protein thiol levels were measured as biomarkers of protein oxidation. DNA fragmentation was evaluated as biomarker of DNA oxidation.</p> <p>Results</p> <p>After 48 h (peak of lytic cycle), a significant increase in conjugated dienes level was observed in B95-8 and Raji cell lines (p = 0.0001 and p = 0.019 respectively). Malondialdehyde adduct, protein carbonyl levels were increased in B95-8 and Raji cell lines after EBV lytic cycle induction as compared to controls (MDA-adduct: p = 0.008 and p = 0.006 respectively; Carbonyl: p = 0.003 and p = 0.0039 respectively). Proteins thiol levels were decreased by induction in B95-8 and Raji cell lines (p = 0.046; p = 0.002 respectively). DNA fragmentation was also detected in B95-8 and Raji cell lines after EBV lytic cycle induction as compared to controls.</p> <p>Conclusion</p> <p>The results of this study demonstrate the presence of increased combined oxidative modifications in lipids, proteins in B95-8 and Raji cells lines after EBV lytic cycle induction. These results suggest that lipid peroxidation, protein oxidation and DNA fragmentation are generally induced during EBV lytic cycle induction and probably contribute to the cytopathic effect of EBV.</p

How does serum brain natriuretic peptide level change under nasal continuous positive airway pressure in obstructive sleep apnea-hypopnea syndrome?

Background: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is associated with cardiovascular morbidity and mortality, which can be improved by using continuous positive airway pressure (CPAP) therapy. However, the pathophysiological links between the two kinds of disease and the mechanism of the CPAP effect remain incompletely understood. We aimed to inquire into the myocardial involvement in this relationship. We suggested that serum brain natriuretic peptide (BNP) is sensitive enough to detect myocardial stress caused by OSAHS.Design and methods: Sixty-four subjects without cardiovascular disease (21 controls, 24 normotensive OSAHS patients, and 19 hypertensive OSAHS patients) were analyzed for serum BNP at baseline and serially over 6 months. CPAP was applied to 23 patients with severe OSAHS.Results: At baseline, the serum BNP levels were significantly higher (p0.0001) in the OSAHS group (22.3914.79 pg/ml) than in the control group (9.296.75 pg/ml). Increased serum BNP levels were significantly associated with mean transcutaneous oxygen saturation (SpO2) (pB0.0001), minimal SpO2 (p0.002), oxygen desaturation index (p0.001), and total sleep time spent with SpO2 lower than 90% (p0.002). All patients with elevated BNP levels (]37 pg/ml) had moderate or severe OSAHS (11/43 OSAHS patients). The more severe the OSAHS, the higher the BNP levels were. However, only the difference between severe and mild OSAHS was statistically significant (p0.029). Hypertensive OSAHS patients had the highest baseline BNP levels (27.7916.74 pg/ml). They were significantly higher (p0.001) than in normotensive OSAHS patients (18911.72 pg/ml) (p0.039) and the controls (9.296.75 pg/ml). As compared with baseline, treatment with CPAP significantly decreased BNP levels in both hypertensive and normotensive OSAHS patients (respectively, from 36916.10 to 29.7914.29 pg/ml, pB0.001, and from 20910.09 to 1698.98 pg/ml, pB0.001). In contrast, the BNP levels slightly increased in the controls (from 9.296.75 to 9.597.02 pg/ml, p0.029), but there was no statistically significant difference in comparison with the baseline value. The effect of CPAP on BNP levels was more marked in patients with higher baseline BNP levels and those with the most prolonged nocturnal desaturation (p0.001, r0.65). It was also more marked in hypertensive OSHAS patients (p0.015, r0.72) in comparison with normotensive OSAHS patients (p0.03, r0.62).Conclusion: BNP seems to be sensitive enough to detect myocardial stress caused by OSAHS. As such, it is a potential marker for screening of preclinical cardiovascular damage in patients with untreated OSAHS. Application of CPAP decreases levels significantly in normotensive and particularly in hypertensive OSAHS. These findings are consistent with previous results suggesting the potential benefits of CPAP on cardiovascular outcome in OSAHS patients.Keywords: sleep apnea; brain natriuretic peptide; positive airway pressure therapy; myocardial stress; hypertensio

Rhaponticum acaule (L) DC essential oil: chemical composition, in vitro antioxidant and enzyme inhibition properties

Background: α-glucosidase is a therapeutic target for diabetes mellitus (DM) and α-glucosidase inhibitors play a vital role in the treatments for the disease. Furthermore, xanthine oxidase (XO) is a key enzyme that catalyzes hypoxanthine and xanthine to uric acid which at high levels can lead to hyperuricemia which is an important cause of gout. Pancreatic lipase (PL) secreted into the duodenum plays a key role in the digestion and absorption of fats. For its importance in lipid digestion, PL represents an attractive target for obesity prevention. Methods: The flowers essential oil of Rhaponticum acaule (L) DC (R. acaule) was characterized using gas chromatography-mass spectrometry (GC-MS). The antioxidant activities of R. acaule essential oil (RaEO) were also determined using 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), reducing power, phosphomolybdenum, and DNA nicking assays. The inhibitory power of RaEO against α-glucosidase, xanthine oxidase and pancreatic lipase was evaluated. Enzyme kinetic studies using Michaelis-Menten and the derived Lineweaver-Burk (LB) plots were performed to understand the possible mechanism of inhibition exercised by the components of this essential oil. Results: The result revealed the presence of 26 compounds (97.4%). The main constituents include germacrene D (49.2%), methyl eugenol (8.3%), (E)-β-ionone (6.2%), β-caryophyllene (5.7%), (E,E)-α-farnesene (4.2%), bicyclogermacrene (4.1%) and (Z)-α-bisabolene (3.7%). The kinetic inhibition study showed that the essential oil demonstrated a strong α-glucosidase inhibiton and it was a mixed inhibitor. On the other hand, our results evidenced that this oil exhibited important xanthine oxidase inhibitory effect, behaving as a non-competitive inhibitor. The essential oil inhibited the turkey pancreatic lipase, with maximum inhibition of 80% achieved at 2 mg/mL. Furthermore, the inhibition of turkey pancreatic lipase by RaEO was an irreversible one. Conclusion: The results revealed that the RaEO is a new promising potential source of antioxidant compounds, endowed with good practical applications for human health. Keywords: α-glucosidase, Antioxidant activity, Chemical composition, Pancreatic lipase inhibition, Rhaponticum acaule essential oil, Xanthine oxidase

Protocol for transmission and archiving of medical images (wavREPro.JPEG)

International audienceThe transmission and archiving of medical images are among the most important operations in telemedicine. Indeed, the collaboration platforms have to ensure video conferencing, medical images and patient data transfer and archiving. However, the big volume of this kind of images represents a major obstacle for the work of a tele-staff. In order to overcome this problem, we suggest a new archiving and transmission protocol that we call "wavREPro.JPEG". Its process consists of two phases. In fact, before the information broadcast, this protocol reduces images by Discrete Wavelet Transforms and compresses them by the classic JPEG. At the reception step, it enlarges images after their decompression. Experimental results have demonstrated that our proposed method is more efficient than the classic JPEG compression. Effectively, it offers more minimisation in terms of network bandwidth consumption and storage space

Medical Image Compression Approach Based on Image Resizing, Digital Watermarking and Lossless Compression

International audienceThe computerization of images have been important for different medical applications. Nevertheless, the huge volume of medical images can rapidly saturate transmission especially in telemedicine field and may encumber storage systems in case of local saving. Data compression represents the most used solution to deal with this problem. Indeed, it can minimize the data space and may reduce both the time of data transfer and bandwidth consumption. In this context, we have proposed new approaches, which combined image reduction and expansion techniques, digital watermarking and lossless compression standards such as JPEG-LS (JLS) and TIFF formats. We named these compression methods wREPro.TIFF (watermarked Reduction/Expansion Protocol combined with TIFF format) and wREPro.JLS (wREPro combined with JPEG-LS format). The results of comparative experiments show that we have provided significant improvements over the well-known JPEG image compression standard. Indeed, our proposed compression algorithms have ensured a better preservation of the image quality notably for high compression ratios

Discrete Wavelet Transforms for PET Image Reduction/Expansion (wavREPro)

International audienceThe large volume of medical images remains a major problem for their archiving and transmission. In this context, we propose a novel protocol wavREPro that aims to minimize the image size before its storage and then to enlarge it at reception. This process has been achieved by exploiting the Discrete Wavelet Transforms (DWT) namely Haar, Le Gall (5/3) and Daubechies (9/7) wavelets. These tools represent the image in the multi-resolution domain that follows the human psycho-visual system. Therefore, the reduced image is none other than the approximation of the image. Its magnification is carried out by either cancelling the details (wavREProZ) or estimating them (wavREProED) using the DWT−1 on the reduced image. Our experiments have been conducted on a PET (Positron Emission Tomography) medical image database and the results have been presented for the three well-known color spaces RGB, HSV and YCbCr. The reported results have promoted the wavREProZ application with the Haar wavelets on RGB images since it achieved maximum fidelity between the original and reduced then enlarged images. The good performance of this approach encourages its adoption to display images on screens having different sizes

Lipid peroxidation, proteins modifications, anti-oxidant enzymes activities and selenium deficiency in the plasma of hashitoxicosis patients

Objectives: The aim of this study was to explore the oxidative stress profile in hashitoxicosis (HTX) and to compare it with that of healthy subjects. Patients and methods: Spectrophotometric methods were used to evaluate the oxidative stress markers. The selenium level was investigated by atomic absorption. Results: High levels of thiobarbituric acid reactive species (TBARS) and conjugated dienes were found in HTX patients ( p = 0.034 and p = 0.043, respectively) compared with healthy controls. For antioxidant enzymes, superoxide dismutase (SOD) and catalase activities increased, whereas that of glutathione peroxidase (GPx) decreased ( p = 0.000, p = 0.014, p = 0.000, respectively) compared with controls. A reduction in the level of selenium ( p = 0.029) and thiol groups ( p = 0.008) were shown in patients; however, levels of carbonyl group and malondialdehyde (MDA) protein adducts decreased ( p = 0.000) compared with controls. Positive correlation was shown between levels of free thyroxine (FT4) and TBARS ( r = 0.711, p = 0.048) and between FT4 level and SOD activity ( r = 0.713, p = 0.047). Conversely, GPx activity presented a negative correlation with FT4 and free triiodothyronine (FT3) levels ( r = –0.934, p = 0.001; r = –0.993, p = 0.000, respectively). In addition, GPx activity showed positive correlation with selenium level ( r = 0.981, p = 0.019) and the FT3 level correlated negatively with the level of thiol groups ( r = –0.892, p = 0.017). Conclusions: This study shows the presence of an oxidative stress and selenium deficiency in HTX patients and suggests that the hyperthyroid state is strongly implicated in the establishment of this disturbed oxidative profile