Association of TP53 gene polymorphisms with the risk of acute lymphoblastic leukemia in Moroccan children

Molecular Biology Reports - TP53 gene plays a pivotal role in maintaining genetic stability and prevention of malignancies. Alterations of this gene are implicated in more than half of human...     

Biochemical and genetic alterations of oxidant/antioxidant status of the brain in rats treated with dexamethasone: protective roles of melatonin and acetyl-<Emphasis Type="SmallCaps">l</Emphasis>-carnitine

The current study was undertaken to investigate the protective role of melatonin (MEL) and acetyl-l-carnitine (ALC) against dexamethasone (DM)-induced neurotoxicity. Adult female rats (60) were divided into: (1) control group, (2) DM-treated group, (3) MEL-treated group, (4) ALC-treated group, (5) MEL- and DM-treated, and (6) ALC- and DM-treated group. Serum acetylcholinesterase (AchE) activity, malondialdehyde (MDA), nitric oxide (NO) level, catalase (CAT), superoxide dismutase (SOD) and glutathione-S-transferase (GST) activities were estimated. Gene expression of the prooxidants (NO synthases NOS-1, NOS-2 and heme oxygenases HO-1, HO-2) and antioxidant enzyme (GST-P1) as well as deoxyribonucleic acid (DNA) fragmentation analysis of brain tissue were investigated. Histological examination of the brain tissue was carried out. DM administration caused significant increase in serum AchE activity, MDA and NO levels accompanied with significant decrease in the antioxidant enzymes activity. Pretreatment with MEL or ALC prior DM has been found to reverse all the former parameters. On the genetic level, DM administration significantly increased the expression level of NOS-1, NOS-2, HO-1, and HO-2 messenger ribonucleic acids (mRNAs) and decreased that GST-P1-mRNA in brain tissue. Also, DM produced DNA fragmentation in brain tissue. Treatment with MEL or ALC prior DM administration tend to normalize the above mentioned parameters. These results were documented by the histological examination of brain tissue. The present study suggests that oxidative stress is involved in the pathogenesis of DM-induced neurotoxicity. The inhibition of oxidative stress via stimulation of the antioxidant enzymes by MEL and ALC pretreatment plays a central protective role in modulation of neurotoxicity induced by DM.     

Rapid UPLC-MS/MS method for routine analysis of plasma pristanic, phytanic, and very long chain fatty acid markers of peroxisomal disorders

Quantification of pristanic acid, phytanic acid, and very long chain fatty acids (i.e., hexacosanoic, tetracosanoic, and docosanoic acids) in plasma is the primary method for investigateing a multitude of peroxisomal disorders (PDs). Typically based on GC-MS, existing methods are time-consuming and laborious. In this paper, we present a rapid and specific liquid chromatography tandem mass spectrometric method based on derivatization with 4-[2-(N,N-dimethylamino)ethylaminosulfonyl]-7-(2-aminoethylamino)-2,1,3-benzoxadiazole (DAABD-AE). Derivatization was undertaken to improve the poor mass spectrometric properties of these fatty acids. Analytes in plasma (20 mul) were hydrolyzed, extracted, and derivatized with DAABD-AE in approximately 2 h. Derivatives were separated on a reverse-phase column and detected by positive-ion electrospray ionization tandem mass spectrometry with a 5 min injection-to-injection time. Calibration plots were linear over ranges that cover physiological and pathological concentrations. Intraday (n = 12) and interday (n = 10) variations at low and high concentrations were less than 9.2%. Reference intervals in normal plasma (n = 250) were established for each compound and were in agreement with the literature. Using specimens from patients with established diagnosis (n = 20), various PDs were reliably detected. In conclusion, this method allows for the detection of at least nine PDs in a 5 min analytical run. Furthermore, this derivatization approach is potentially applicable to other disease markers carrying the carboxylic group.     

Dietary Lactobacillus acidophilus ATCC 4356 Relieves the Impacts of Aflatoxin B1 Toxicity on the Growth Performance,Hepatorenal Functions,and Antioxidative Capacity of Thinlip Grey Mullet (Liza ramada) (Risso 1826)

Probiotics and Antimicrobial Proteins - Dietary Lactobacillus acidophilus ATCC 4356 was used to relieve the impacts of aflatoxin B1 toxicity on the performances of Liza ramada. The control diet was...     

The extracellular polysaccharide of Porphyridium sp.: an NMR study of lithium-resistant oligosaccharidic fragments

This study deals with the chemical characterization of an extracellular polysaccharide produced by the unicellular red alga Porphyridium sp. The sugar moiety of this polymer is composed of three neutral monosaccharides (Xyl, Glc, and Gal) and one uronic acid (GlcA). Proteins represent 5.5% of the dry weight of the polymer. Uronic degradation of this exopolysaccharide with lithium in ethylenediamine yielded two different oligosaccharides. The absolute configuration of the constitutive monosaccharides was chemically determined and revealed the presence of D-Xyl, D-Glc, D-, and L-Gal. The following oligosaccharide structures were established by NMR spectroscopy: [carbohydrate structure: see text].     

Plasmodial Aspartyl-tRNA Synthetases and Peculiarities in Plasmodium falciparum

Distinctive features of aspartyl-transfer RNA (tRNA) synthetases (AspRS) from the protozoan Plasmodium genus are described. These apicomplexan AspRSs contain 29–31 amino acid insertions in their anticodon binding domains, a remarkably long N-terminal appendix that varies in size from 110 to 165 amino acids and two potential initiation codons. This article focuses on the atypical functional and structural properties of Plasmodium falciparum cytosolic AspRS, the causative parasite of human malaria. This species encodes a 626 or 577 amino acids AspRS depending on whether initiation starts on the first or second in-frame initiation codon. The longer protein has poor solubility and a propensity to aggregate. Production of the short version was favored as shown by the comparison of the recombinant protein with endogenous AspRS. Comparison of the tRNA aminoacylation activity of wild-type and mutant parasite AspRSs with those of yeast and human AspRSs revealed unique properties. The N-terminal extension contains a motif that provides unexpectedly strong RNA binding to plasmodial AspRS. Furthermore, experiments demonstrated the requirement of the plasmodial insertion for AspRS dimerization and, therefore, tRNA aminoacylation and other putative functions. Implications for the parasite biology are proposed. These data provide a robust background for unraveling the precise functional properties of the parasite AspRS and for developing novel lead compounds against malaria, targeting its idiosyncratic domains.Aminoacyl-tRNA synthetases (aaRSs)² are ubiquitous enzymes that attach amino acids to their cognate transfer RNAs (tRNAs) during protein synthesis. In ensuring high fidelity of tRNA aminoacylation, they maintain the genetic code and consequently contribute to cell viability in all forms of life. aaRSs are divided into two classes depending on the architectural organization of their catalytic domains and the way that they recognize their tRNA substrates. They have modular architectures which exhibit overall evolutionary conservation but also idiosyncratic features that indicate their phylogenetic origins (1). Such features are potential targets for aaRS inhibitors and, thus, for antipathogenic compounds. In addition to their important role in protein synthesis, aaRSs have developed a large panel of new functions during their evolutionary history that impact cell physiology and dysfunctions in ways that are not well understood (2, 3).Within the aaRS family, aspartyl-tRNA synthetases (AspRS) are among the most thoroughly investigated for both structural and functional aspects (4–11). AspRSs are dimeric proteins that belong to class IIb synthetases. Their subunits have a conserved modular architecture in the three kingdoms of life with a C-terminal catalytic module linked by a short hinge domain to an N-terminal anticodon binding module. An additional domain is found on the N-terminal module of eukaryotic AspRSs that has been shown in the case of the Saccharomyces cerevisiae enzyme to help anchor the tRNA to the enzyme core (12) (see Fig. 1A). However, despite the large amount of data collected, our understanding of AspRSs is incomplete as enzymes originating from entire classes in the tree of life have not been studied. This is the case with eukaryotic AspRSs and, among them, those of the genus Plasmodium.Open in a separate windowFIGURE 1.Overall organization of plasmodial AspRS sequences (numbering is according to P. falciparum protein or gene sequence). A, modular arrangement of AspRSs with features important to structure and function indicated. The three modules of the AspRS core are shown in heavy lines together with the eukaryotic and prokaryotic N and C-terminal extensions (and the N-terminal organellar signals) in light lines. Novel domains in Plasmodium AspRSs are in black; domains strictly present in all AspRSs are in gray (motifs 1, 2, 3 are class II aaRS-specific, flipping loop is AspRS-specific, and RNA binding motif is specific of eukaryotic AspRSs except those from mammals and birds). B, sequence alignment of Plasmodium AspRSs with the RNA binding motif and plasmodial insertion boxed and predicted secondary structure elements in the N-terminal eukaryotic extension indicated. Large numbers delineate structural modules; dots indicate the two methionine residues coded by in-frame ATG codons. Protein sequences are from PlasmoDB: P. reichenowi (Partial Genome Shotgun, join reich314f03.plk and reich249e05.plk), P. falciparum (PFA0145c), P. vivax (Pv081610), P. knowlesi (PKH_021050), P. berghei (PB000914.03.0), and P. yoelii (PY01511). C, sequence alignment of mRNA 5′-ends from Plasmodium AspRSs. Only sequences surrounding the two in-frame ATG codons are displayed and compared with the Kozak consensus sequence. The untranslated region (UTR) sequences preceding the first ATG are in italics. Notice the better fit of sequences around the second ATG with the Kozak consensus.To date nothing is known about plasmodia AspRSs; in fact, all aaRSs (and translation in general) in the Plasmodium genus remain unstudied despite the acute medical importance of these parasites that cause malaria. Plasmodia belong to the Apicomplexa, a phylum of the alveolates (unicellular protists) (13) close to fungi and plants (14). Among the several species that infect humans, Plasmodium falciparum causes the most deadly form of malaria. Each year it infects 600 million people and causes three million deaths (see the Malaria Foundation International website). Plasmodia contain three genomes; in their nuclei, in their mitochondria, and in their apicoplasts, a secondary plastid. The three complete genomes of P. falciparum have been sequenced, namely a 23-megabase nuclear genome divided between 14 chromosomes (15), a 6-kilobase mitochondrial genome (16) and a 35-kilobase apicoplastic genome (17). Altogether 5300 protein genes were predicted, including ∼35 aaRS genes of the highly conserved genes coding for proteins involved in translation (cytosolic and apicoplastic), all encoded in the nuclear genome. The nuclear genome also contains 43 tRNA genes (Genomic tRNA Database) (18). Noticeably, the small mitochondrial genome is devoid of both aaRS and tRNA genes, whereas the apicoplastic genome codes only tRNAs (19, 20). Thus, for translation to occur in the organelles implies the import of tRNA and aaRSs.Based on known genomic sequences, this work analyzes the structure of plasmodial AspRSs and demonstrates their similarity to S. cerevisiae and Homo sapiens homologs. Interestingly, it also reveals peculiarities not previously observed in other AspRSs, in particular an insertion in the anticodon binding domain and an extra long N-terminal extension. The AspRS from P. falciparum was chosen for more thorough investigation. The protein was overexpressed in Escherichia coli and its distinctive physicochemical and biochemical properties were established and compared with those of its human host counterpart. The implications of these new findings are discussed.     

Dietary supplementation with whey protein and ginseng extract counteracts oxidative stress and DNA damage in rats fed an aflatoxin-contaminated diet

Aflatoxins (AF) are among the most potent naturally occurring carcinogens and aflatoxin-B1 (AFB(1)) is classified as a group-1 carcinogen. Since the ingestion of aflatoxins-contaminated food is associated with several liver diseases, the aim of the present study was to evaluate whether AF-induced damage in rats can be counteracted by feeding with whey-protein concentrates (WPC) and Korean ginseng extract (KGE). Eighty male Sprague-Dawley rats were divided into eight equal groups and treated daily for 30 days as follows: a control group (fed an AF-free diet), a group fed ad libitum an AF-contaminated diet (2.5mg/kg diet), a group treated orally with WPC (0.5ml/rat/day), a group treated orally with KGE (20mg/kg body weight), a group treated orally with WPC+KGE, and three groups that were fed the AF-contaminated diet and were treated orally with WPC, KGE or WPC+KGE, respectively. Throughout the experimental period, animals received WPC or KGE during the consumption of their respective diet. Bone-marrow micronucleus formation, DNA fragmentation, fatty-acid synthesis (FAS) and phospholipid-hydroperoxide-glutathione-peroxidase (PHGPx) mRNA expression, and oxidative stress were assayed in liver and testis. The results indicated that ingestion of aflatoxin resulted in a significant increase in micronucleated normochromatic erythrocytes (Mn-NCE) in bone marrow, DNA fragmentation, FAS mRNA expression and lipid peroxidation in both organs, and a significant decrease in micronucleated polychromatic erythrocytes/micronucleated normochromatic erythrocytes (PCE/NCE) ratio in bone marrow, PHGPx gene expression and GSH in liver and testis. Treatments with WPC and/or KGE had a significant effect on Mn-NCE or the PCE/NCE ratio in bone marrow. However, KGE or KGE+WPC increased PHGPx gene expression and GSH in testis accompanied with a significant decrease in lipid peroxidation in liver and testis and FAS-mRNA expression in liver. WPC, KGE or WPC+KGE treatments combined with exposure to an AF-contaminated diet restored all the test parameters towards control values, although they did not fully reverse the effects of the aflatoxins. It is suggested that the genotoxicity of aflatoxins can be in part prevented by dietary supplementation with WPC, KGE or their combination.     

Genetically different clonal isolates of Trichomonas gallinae, obtained from the same bird, can vary in their drug susceptibility, an in vitro evidence

Trichomonas gallinae is a flagellated protozoon which parasitizes in the upper digestive tract of different birds, especially columbiformes (doves and pigeons) and falconiformes. The parasite is also a common inhabitant of the crop of psittacine birds and is frequently detected in budgerigars. The lesions associated with T. gallinae infection of the upper digestive tract range from mild inflammation of the mucosa to large caseous lesions that block the lumen of the oesophagus. Nitroimidazoles are considered to be the drugs of choice for the treatment of trichomonosis. However, only a few studies report the existence of resistant strains of T. gallinae to these drugs. Thus, in the present investigation cloned cultures of T. gallinae obtained from budgerigars and pigeons were analysed for the first time for their in vitro susceptibilities against four 5′-nitroimidazole derivates, including metronidazole, dimetridazole, ronidazole and ornidazole. Significantly different minimal lethal concentrations (MLCs) were observed for them against all four drugs. The lowest MLCs revealed the Trichomonas isolates obtained from two budgerigars, ranging from 2.0 ± 0.3 to 3.0 ± 0.7 μg/ml for metronidazole and dimetridazole, and from 2.0 ± 0.6 to 6.7 ± 1.7 μg/ml for ornidazole and ronidazole. Contrary to this, the highest MLCs were recorded for one Trichomonas isolate obtained from a pigeon, ranging from 83.3 ± 6.7 (for dimetridazole and ronidazole) to 103.3 ± 3.3 μg/ml (for metronidazole and ornidazole). The data obtained for the resistance testing were further compared with already available genetic data of the small subunit rRNA gene sequences and ITS-1, 5.8S rRNA and ITS-2 sequences, indicating a certain correlation between in vitro results and strain relationships.     

Investigation of the significance of Oil Red O‐positive macrophage excess in bronchoalveolar lavage fluid during HIV infection

L. Lacoste‐Collin, G. Martin‐Blondel, C. Basset‐Léobon, V. Lauwers‐Cancès, D. d’Aure, J. Aziza, A. Berry, B Marchou, M.B. Delisle and M. Courtade‐Saïdi Investigation of the significance of Oil Red O‐positive macrophage excess in bronchoalveolar lavage fluid during HIV infection Objective: To assess the significance of increased levels of Oil Red O‐positive macrophages (ORO‐PM) in bronchoalveolar lavage fluids (BALFs) from HIV‐positive patients. Methods: Cytological data for seventy BALF samples from 66 consecutive HIV‐infected patients were analysed according to antiretroviral therapy regimen, presence of Pneumocystis jiroveci infection, blood CD4⁺T cell count, HIV‐1 viral load and plasma lipid levels. Non‐parametric tests were used to compare the values between groups. Results: The percentages of ORO‐PM were high in this group: 40% [6–80] (median [interquartile range]). They were positively correlated with the BALF total cell count, 21% [5–48.5] for <300 cells/mm³ and 60% [26.5–80] for >300 cells/mm³ (P < 0.01) but inversely correlated with the percentage of BALF lymphocytes, 50% [20–80] for <15% lymphocytes and 11.5% [2–47] for ≥15% lymphocytes (P < 0.01). Antiretroviral therapy with or without protease inhibitors, plasma lipid levels, HIV‐1 viral load, blood CD4⁺T cell count or presence of a Pneumocystis jiroveci infection were not correlated with the ORO‐PM status. Conclusion: Significantly increased numbers of ORO‐PM were correlated with high total cell counts and low lymphocyte counts in BALF, irrespective of disease activity or treatment. Extended work on a larger series of patients needs to be conducted.