Silver-coated magnetic nanoparticles as an efficient delivery system for the antibiotics trimethoprim and sulfamethoxazole against E. Coli and S. aureus: release kinetics and antimicrobial activity

BioMetals - Trimethoprim and sulfamethoxazole are prescribed for a broad spectrum of bacteria. However, the use of these medicines is restricted due to the risk of microbial resistance in the body....     

A novel copper (II) complex activated both extrinsic and intrinsic apoptotic pathways in liver cancerous cells

Recent advances have put fundamental focus on the application of copper (II) (Cu [II]) complexes as agents for fighting against cancer. To determine whether [Cu(L)(2imi)] complex as a novel Cu complex can induce apoptosis in HepG2 as cancerous cells and L929 as normal cells via extrinsic or intrinsic apoptotic pathways, both cell lines were treated for 24 and 48 hours at IC₅₀ concentrations of [Cu(L)(2imi)] complex. Then, the expression of some apoptosis-related genes including p53, caspase-8, bcl-2, and bax were assayed by real-time polymerase chain reaction. The [Cu(L)(2imi)] complex seems to inhibit the expression of bcl-2 in complex-treated HepG2 cancerous cells following the 24- and 48-hour treatment. The complex upregulated the p53, bax, and caspase-8 genes, therefore treatment of HepG2 cancerous cells with [Cu(L)(2imi)] complex induces programmed cell death via the upregulation of relative bax/bcl-2 ratio. Finally, this copper complex triggered apoptosis in HepG2 cells via both intrinsic and extrinsic pathway, whereas treatment of normal L929 cells with this complex induce apoptosis only via intrinsic pathway with the upregulation of relative bax/bcl-2 ratio and does not affect the expression level of caspase-8 gene and does not trigger the extrinsic pathway. Finally, these results obtained from present study confirm the role of a novel Cu complex on the induction of apoptosis process in HepG2 and L929 cells by overexpression of bax, inhibition of bcl-2 and increase of the relative bax/bcl-2 ratio. These results support that the [Cu(L)(2imi)] complex is able to induce apoptosis in cancerous cells, therefore, it has a potential for development as a novel anticancer drug.     

Cladistic analysis of anuran POMC sequences

Procedures for performing cladistic analyses can provide powerful tools for understanding the evolution of neuropeptide and polypeptide hormone coding genes. These analyses can be done on either amino acid data sets or nucleotide data sets and can utilize several different algorithms that are dependent on distinct sets of operating assumptions and constraints. In some cases, the results of these analyses can be used to gauge phylogenetic relationships between taxa. Selecting the proper cladistic analysis strategy is dependent on the taxonomic level of analysis and the rate of evolution within the orthologous genes being evaluated. For example, previous studies have shown that the amino acid sequence of proopiomelanocortin (POMC), the common precursor for the melanocortins and beta-endorphin, can be used to resolve phylogenetic relationships at the class and order level. This study tested the hypothesis that POMC sequences could be used to resolve phylogenetic relationships at the family taxonomic level. Cladistic analyses were performed on amphibian POMC sequences characterized from the marine toad, Bufo marinus (family Bufonidae; this study), the spadefoot toad, Spea multiplicatus (family Pelobatidae), the African clawed frog, Xenopus laevis (family Pipidae) and the laughing frog, Rana ridibunda (family Ranidae). In these analyses the sequence of Australian lungfish POMC was used as the outgroup. The analyses were done at the amino acid level using the maximum parsimony algorithm and at the nucleotide level using the maximum likelihood algorithm. For the anuran POMC genes, analysis at the nucleotide level using the maximum likelihood algorithm generated a cladogram with higher bootstrap values than the maximum parsimony analysis of the POMC amino acid data set. For anuran POMC sequences, analysis of nucleotide sequences using the maximum likelihood algorithm would appear to be the preferred strategy for resolving phylogenetic relationships at the family taxonomic level.     

Identification of virulence factors in Vibrio cholerae isolated from Iraq during the 2007-2009 outbreak

Thousands of people were infected with Vibrio cholerae during the outbreak in Iraq in 2007-2009. Vibrio cholerae was shown to be variable in its content of virulence determinants and in its antibiotic sensitivity. This study was designed to isolate and characterize clinical and environmental V.?cholerae isolates and to determine antibiotic sensitivity, enzyme and toxin production, and the presence of virulence genes. Eighty clinical and five environmental bacterial isolates were collected and diagnosed by subjecting them to microscopic, biochemical, serological, and molecular analysis. The results revealed that 55% of clinical isolates belonged to the Inaba serotype, 32.5% to the Ogawa serotypes, and 12.5% to the Non-O1 serotype. All environmental V.?cholerae isolates belonged to the Non-O1 serotype. All environmental isolates were sensitive to all examined antimicrobial agents, while all clinical isolates showed a high sensitivity (100%) to ampicillin, gentamicin, cephalothin, tetracycline, erythromycin, and ciprofloxacin, and a high resistance (97.5%) to co-trimoxazole, nalidixic acid, and chloramphenicol. It was found that all V.?cholerae (O1) isolates were resistant to the Vibrio static O129 and all Non-O1 V.?cholerae isolates were sensitive to the Vibrio static O129. All clinical and environmental isolates produced hemolysin (100%) and lecithinase (100%), while they showed various production rates of protease (90% of clinical and 60% of environmental) and lipase (50% of clinical and 20% of environmental). The ompW gene was amplified in all the clinical and environmental V.?cholerae isolates, but not in other related and nonrelated bacteria. Multiplex PCR analysis showed that the toxR gene was amplified in all clinical and environmental isolates, while ctxA, ctxB, tcpA genes were amplified only in clinical (O1) isolates. This study indicates the differences in the production of some enzymes and toxins and in the content of virulence genes between clinical and environmental isolates in Iraq during the outbreak (2007-2009).     

Is Time to Reach EDSS 6.0 Faster in Patients with Late-Onset versus Young-Onset Multiple Sclerosis?

MethodsThis cross-sectional cohort study was conducted to identify LOMS and YOMS patients’ with relapsing remitting course at MS diagnosis. Time (years) to reach sustained EDSS 6.0 was compared between LOMS and AOMS patients. Cox proportional hazards model was used to evaluate the demographic and clinical predictors of time to EDSS 6.0 in these cohorts.ResultsLOMS and YOMS cohorts comprised 99 (10.7%) and 804 (89.3%) patients respectively. Spinal cord presentation at MS onset was more common among LOMS patients (46.5% vs. 32.3%). The proportions of LOMS and YOMS patients reaching EDSS 6.0 during the follow-up period were 19.2% and 15.7% respectively. In multivariable Cox proportional hazards model, older age at MS onset (adjusted hazard ratio (aHR) = 3.96; 95% CI: 2.14–7.32; p < 0.001), male gender (aHR = 1.85; 95% CI: 1.22–2.81; p = 0.004) and spinal cord presentation at onset (aHR = 1.47; 95% CI: 0.98–2.21; p = 0.062) were significantly associated with shorter time to EDSS 6.0.ConclusionsLOMS patients attained EDSS 6.0 in a significantly shorter period that was influenced by male gender and spinal cord presentation at MS onset.     

Cloning of a neoteleost (Oreochromis mossambicus) pro-opiomelanocortin (POMC) cDNA reveals a deletion of the γ-melanotropin region and most of the joining peptide region: implications for POMC processing

A signature feature of tetrapod pro-opiomelanocortin (POMC) is the presence of three melantropin (MSH) coding regions (α-MSH, β-MSH, γ-MSH). The MSH duplication events occurred early during the radiation of the jawed vertebrates well over 400 million years ago. However, in at least one order of modern bony fish (subdivision Teleostei; order Salmoniformes; i.e. salmon and trout) the γ-MSH sequence has been deleted from POMC. To determine whether the γ-MSH deletion has occurred in other teleost orders, a POMC cDNA was cloned from the pituitary of the neoteleost Oreochromis mossambicus (order Perciformes). In O. mossambicus POMC, the deletion is more extensive and includes the γ-MSH sequence and most of the joining peptide region. Because the salmoniform and perciform teleosts do not share a direct common ancestor, the γ-MSH deletion event must have occurred early in the evolution of the neoteleost fishes. The post-translational processing of O. mossambicus POMC occurs despite the fact that the proteolytic recognition sequence, (R/K)-X_n-(R/K) where n can be 0, 2, 4, or 6, a common feature in mammalian neuropeptide and polypeptide hormone precursors, is not present at several cleavage sites in O. mossambicus POMC. These observations would indicate that either the prohormone convertases in teleost fish use distinct recognition sequences or vertebrate prohormone convertases are capable of recognizing a greater number of primary sequence motifs around proteolytic cleavage sites.     

Resistance of wheat lines to Rhopalosiphum padi (Hemiptera: Aphididae) under laboratory conditions

Bird cherry-oat aphid, Rhopalosiphum padi (L.), a polyphagous species with a nearly worldwide distribution, is an important pest of wheat as well as the main vector of barley yellow dwarf virus. We evaluated the resistance categories of eight wheat lines including antibiosis, antixenosis, and tolerance against R. padi under laboratory conditions. The wheat lines tested were ERWYT 88-8, ERWYT 87-6, and ERWYT 87-4 (resistant); ERWYT 87-1, ERWYT 87-20, and ERWYT 88-11 (susceptible); ERWYT 88-12 and ERWYT 88-13 (intermediate). In the antibiosis experiment, R. padi produced fewest progeny on ERWYT 88-8, ERWYT 87-6, and ERWYT 87-4 in reproduction period. In the antixenosis test, R. padi performed best on ERWYT 87-1, ERWYT 87-20, and ERWYT 88-11. Fewer apterous aphids selected ERWYT 88-8, ERWYT 87-4, and ERWYT 87-6 lines indicating antixenosis of these lines to R. padi. In tolerance experiments, however growth parameters differed between treated and untreated seedlings of wheat lines with 10 aphids per day infestation during 21-d period, but not among eight wheat lines. The plant resistance index values were greatest for ERWYT 88-8 (9.71), followed by ERWYT 87-4 (7.04) and ERWYT 87-6 (4.76). ERWYT 88-8, ERWYT 87-6, and ERWYT 87-4 may be important sources of R. padi resistance for small grain breeding and integrated pest management programs.     

Benzo(a)pyrene exposure induces CYP1A1 activity and expression in human endometrial cells

Estrogen is a major risk factor for endometrial cancer and it has been well-established that smokers have a significantly reduced risk of endometrial cancer. Localized levels of estrogen within the uterus may determine the estrogenic response. The objective of this research was to investigate effects of cigarette smoke related hydrocarbons (benzo(a)pyrene, BP) on uterine CYP1A1/2 and 1B1, enzymes involved in estrogen metabolism. Human endometrium epithelial cells (RL95-2) were incubated with various concentrations (0.05, 0.1, 0.5, 1, and 10mM) of BP for 48h. CYP1 catalytic activity, protein and mRNA levels were determined. Selective chemical and immuno-inhibitors were used to determine the contribution of individual CYP1 isoenzymes. Cells expressing CYP1A1, CYP1A2 and CYP1B1 were used for comparisons. CYP1A1/2 protein and mRNA levels were significantly elevated by BP. Low level of constitutive CYP1 activity was observed in RL95-2 cells, which was significantly induced by BP exposure (12-fold at 1mM). CYP1 activity in BP-induced cells was significantly inhibited by specific anti-CYP1A1 and high concentration of alpha-naphthoflavone (ANF, 100nM), but not by selective CYP1A2 (furafylline) and CYP1B1 (homoeriodictoyl) inhibitors and low concentration of ANF (5nM). These studies suggest that CYP1A2 and CYP1B1 are not induced by BP in the endometrial cells. It also appears that CYP1A1 is one of the major CYP450 enzymes induced by BP.     

Baeyer-Villiger monooxygenases from microorganisms

Abstract The oxidation of bicyclo[3.2.0]hept-2-en-6-one and 7- endo propylbicyclo[3.2.0]hept-2-en-one was investigated using whole cells of Pseudomonas putida NCIMB 10007 and Xanthobacter autotrophicus NCIMB 10811. The bacteria demonstrated both regio- and enantioselective oxidation of the substrates. P. putida gave 'mirror image' with both substrates when the products of these oxidations were compared with cells grown on the different enantiomers of camphor. The regio- and enantioselectivity of the oxidation of the substrates by X. autotrophicus were enhanced by the 7- endo propyl substitution of bicyclo[3.2.0]hept-2-en-6-one.