Epstein-Barr virus induces an oxidative stress during the early stages of infection in B lymphocytes, epithelial, and lymphoblastoid cell lines

The study investigates the direct effect of Epstein-Barr virus infection on the oxidative profile of in vitro cultivated human cells. For this purpose, a panel of human EBV target cells presenting heterogeneity in their cellular and culture types (epithelial cells or lymphocytes; primary culture or continuous cell culture) was selected. These cells are purified human B lymphocytes, DG75, 293, and HepG2 cell lines. The oxidative stress was evaluated during the early stages of infection (2, 12, and 24 h) by measuring malondialdehyde, the end product of the lipid peroxidation, as well as the activities of two antioxidant enzymes: catalase and superoxide dismutase. The obtained results were compared with those of the untreated cells and the K562 cell line which has no interaction with EBV. The incubation of the different target cells with EBV induced an oxidative stress in the purified B lymphocytes, DG75, and 293, but not in HepG2 and K562. This oxidative stress was highlighted by an increase in MDA level (P < 0.05), which began 2 h after the addition of the virus and persisted after 12 and 24 h. Simultaneously, a decrease in catalase and superoxide dismutase activities was observed (P < 0.05), suggesting an alteration of the molecular mechanisms promoting cellular resistance to reactive oxygen species (ROS). The efficiency of EBV infection, assessed by viral DNA PCR amplification, was confirmed in 293 and DG75 but not in HepG2, which was in total concordance with their oxidative profiles. In conclusion, the EBV infection of B and epithelial cells leads to the establishment of an oxidative stress which can play a key role during the viral transformation.     

Masson’s tumor of the kidney: a case report

Background

Intravascular papillary endothelial hyperplasia (known also as Masson’s tumor) is a benign vascular lesion that commonly occurs in the skin and is rarely found in solid organs, especially in the kidney. In what follows, we will look into the first case of an unexpectedly diagnosed Masson’s tumor of the kidney presenting as a suspicious renal cyst.

Case presentation

A 61-year-old Arab man presented with a left renal cyst, incidentally revealed by ultrasonography. The laboratory values were unremarkable. Computed tomography and magnetic resonance imaging demonstrated a 38 mm left renal midportion Bosniak IV cyst. Our patient underwent a radical nephrectomy. Histopathology revealed the diagnosis of intravascular papillary endothelial hyperplasia. There was no recurrence detected after 9 years of follow-up.

Conclusions

Renal intravascular papillary endothelial hyperplasia is a rare benign tumor which can mimic a suspicious renal mass on radiological findings. Thus, this entity should be considered more often in the thick of the diagnostic possibilities in order to avoid unnecessary nephrectomies.

     

When Color Really Matters: Horticultural Performance and Functional Quality of High-Lycopene Tomatoes

Introgression of spontaneous or induced mutations has been used to increase the levels and diversify the profile of antioxidants in many fruits including tomato. The high-pigment (hp) and old-gold (og) alleles exemplify this approach as attractive genetic resources suitable to inbred elite high-lycopene (HLY) tomato lines with improved color and nutritional attributes. Although several studies have been published on HLY tomatoes, a systematic analysis of the information on their agronomic performances, processing features, and functional quality is lacking, leaving room for the assumption of their poor competitiveness with conventional tomato cultivars and limiting their agricultural diffusion. Therefore, the aim of this study is to critically review the most important agronomic, horticultural, and functional traits of HLY tomatoes, as well as the advances in some emerging (pre)industrial applications. Field experiments performed in different countries showed that most available HLY lines are productive, vigorous, with excellent foliage cover and with morphologically acceptable fruit. Tomato yield of HLY genotypes ranged from ～30 to ～178 t/ha exceeding, in some trials, that of highly productive cultivars. Red-ripe fruits of most HLY lines showed commercially suitable soluble solids and titratable acidity, in addition to increased levels of lycopene (up to 440 mg/kg fw) and other bioactive phytochemicals (mainly flavonoids and vitamin C) compared to their near isogenic conventional counterparts. Innovative (pre)industrial uses of HLY tomato include the following: (1) production of HLY sauces, juices, and powders; (2) supercritical-CO₂ extraction of lycopene containing oleoresins; and (3) preparation of lycopene rich micro- and nano-carriers with improved stability and specific tissue delivery. In turn, the use of these innovative high-quality ingredients in the formulation of lycopene fortified foods, cosmetic products, nutraceuticals, and pharmaceuticals has been proposed as the basis of a novel highly profitable tomato product chain.     

Responses of Arabidopsis thaliana to bicarbonate-induced iron deficiency

Morpho-physiological and biochemical responses of Arabidopsis thaliana (accession N1438) to bicarbonate-induced iron deficiency were investigated. Plants were grown in cabinet under controlled conditions, in a nutrient solution containing 5 μM Fe, added or not with 10 mM NaHCO₃. After 30 days, bicarbonate-treated plants displayed significantly lower biomass, leaf number and leaf surface area as compared to control plants, and slight yellowing of their younger leaves was observed. Potassium (K⁺) content was not modified by bicarbonate treatment in roots, whereas it was significantly diminished in shoots. Their content in ferrous iron (Fe²⁺) and in leaf total chlorophylls was noticeably lower than in control plants. Root Fe(III)-chelate reductase and phosphoenolpyruvate carboxylase (PEPC) activities were significantly enhanced, but leaf ribulose 1.5-bisphosphate carboxylase (Rubisco) activity was decreased.     

Quantum chemical studies for oxidation of morpholine by Cytochrome P450

Since morpholine oxidation has recently been shown to involve Cytochrome P450, the study on its mechanism at molecular level using quantum chemical calculations for the model of cytochrome active site is reported here. The reaction pathway is investigated for two electronic states, the doublet and the quartet, by means of density functional theory. The results show that morpholine hydroxylation occurs through hydrogen atom abstraction and rebound mechanism. However, in the low spin state, the reaction is concerted and hydrogen atom abstraction yields directly ferric-hydroxy morpholine complex without a distinct rebound step while in quartet state the reaction is stepwise. The presence of nitrogen in a morpholine heterocycle is postulated to greatly facilitate hydrogen abstraction. The hydroxylated product undergoes intramolecular hydrogen atom transfer from hydroxy group to nitrogen, leading to the cleavage of the C-N bond and the formation of 2-(2-aminoethoxy) acetaldehyde. The cleavage of the C-N bond is indicated as the rate-determining step for the studied reaction. The assistance of explicit water molecule is shown to lower the energy barrier for the C-N bond cleavage in enzymatic environment whereas solvent effects mimicked by COSMO solvent model have minor influence on relative energies along the pathway.     

Bacteriocinogenic properties and in vitro probiotic potential of enterococci from Tunisian dairy products

The aim of this study was to isolate new bacteriocinogenic strains with putative probiotic potential from various Tunisian fermented milks. A total of 44 Gram-positive catalase-negative isolates were colony-purified and screened for antimicrobial activity. Of inhibitory isolates, four were identified as Enterococcus durans and one as Enterococcus faecalis using 16S rRNA gene sequence. The five strains were sensitive to penicillin G, all aminoglycosides tested, to the vancomycin, tetracycline, and chloramphenicol, and E. durans 42G and E. faecalis 61B were resistant to erythromycin. The antimicrobial substances were sensitive to proteolytic enzymes and had good biochemical stability. E. durans 61A showed a good resistance to gastric and small intestinal secretions, but were more sensitive to the duodenal conditions. Considering the safety and the stability under simulated gastrointestinal tract, it appears that the bacteriocinogenic strain E. durans 61A is a good candidate for its application as novel probiotic strain in the food industry.     

Evaluation of a gp63–PCR Based Assay as a Molecular Diagnosis Tool in Canine Leishmaniasis in Tunisia

A gp63PCR method was evaluated for the detection and characterization of Leishmania (Leishmania) (L.) parasites in canine lymph node aspirates. This tool was tested and compared to other PCRs based on the amplification of 18S ribosomal genes, a L. infantum specific repetitive sequence and kinetoplastic DNA minicircles, and to classical parasitological (smear examination and/or culture) or serological (IFAT) techniques on a sample of 40 dogs, originating from different L. infantum endemic regions in Tunisia. Sensitivity and specificity of all the PCR assays were evaluated on parasitologically confirmed dogs within this sample (N = 18) and control dogs (N = 45) originating from non–endemic countries in northern Europe and Australia. The gp63 PCR had 83.5% sensitivity and 100% specificity, a performance comparable to the kinetoplast PCR assay and better than the other assays. These assays had comparable results when the gels were southern transferred and hybridized with a radioactive probe. As different infection rates were found according to the technique, concordance of the results was estimated by (κ) test. Best concordance values were between the gp63PCR and parasitological methods (74.6%, 95% confidence intervals CI: 58.8–95.4%) or serology IFAT technique (47.4%, 95% CI: 23.5–71.3%). However, taken together Gp63 and Rib assays covered most of the samples found positive making of them a good alternative for determination of infection rates. Potential of the gp63PCR-RFLP assay for analysis of parasite genetic diversity within samples was also evaluated using 5 restriction enzymes. RFLP analysis confirmed assignment of the parasites infecting the dogs to L. infantum species and illustrated occurrence of multiple variants in the different endemic foci. Gp63 PCR assay thus constitutes a useful tool in molecular diagnosis of L. infantum infections in dogs in Tunisia.     

BACTIBASE second release: a database and tool platform for bacteriocin characterization

Background  

BACTIBASE is an integrated open-access database designed for the characterization of bacterial antimicrobial peptides, commonly known as bacteriocins.     

Biological activities of the essential oils and methanol extract of tow cultivated mint species (<Emphasis Type="Italic">Mentha longifolia</Emphasis> and <Emphasis Type="Italic">Mentha pulegium</Emphasis>) used in the Tunisian folkloric medicine

The composition of the essential oils and methanolic extracts of two cultivated mint species (M. longifolia and M. pulegium), as well as the in vitro antimicrobial and antioxidant activities of the essential oil and methanol extract of Mentha longifolia and Mentha pulegium were compared. GC-MS analysis of the essential oil identified 41 compounds constituting 96.66 and 96.13% of the total oil from M. longifolia and M. pulegium, respectively. The later oils were rich on pulegone (47.15 and 61.11%, respectively). Moreover, 1,8 cineole (11.54%), menthone (10.7%), α-pinene (3.57%), α-terpineol (3.17%) and d-cadinene (3.53%) were only present in M. longifolia oil, while isomenthone (17.02%), and piperitone (2.63%), were characteristic of M. pulegium oil. Shoot extract of the two species showed significantly different contents in total polyphenols (89.1 and 37.41 mg GAE/g DW), flavonoids (63.93 and 33.83 mg CE/g DW) and tannins (1.47 and 3.07 mg CE/g DW), respectively in M. longifolia and M. pulegium. The essential oils showed strong antimicrobial activity against all 16 microorganisms tested, whereas the methanol extracts were inactive. Moreover, the essential oils showed higher antioxidant activity than the methanolic extracts against the DPPH and superoxide radical scavenging. In fact, antioxidant activities of the oils were the same for both M. longifolia and M. pulegium against DPPH (IC₅₀ = 9 and 10 μg/ml, respectively) and 2-fold and 4-fold higher than shoot extracts (IC₅₀ = 20 and 48 μg/ml, respectively). Moreover, both oils showed the same antioxidative abilities as compared to the positive control (butylated hydroxytoluene). In the same way, the capacity to inhibit superoxide anion was very significant for the two oils (0.1 μg/ml for M. longifolia and 0.11 μg/ml for M. pulegium).