Amelioration of doxorubicin-induced cardiotoxicity by deferiprone in rats

The therapeutic usefulness of doxorubicin (Dox), an anthracycline antibiotic used as an anticancer agent, is limited by its cardiotoxicity. Dox-induced cardiotoxicity is mainly attributed to accumulation of reactive oxygen species and interaction of Dox with cellular iron metabolism. The present study investigated the effects of the iron chelator deferiprone (Def) against Dox-induced cardiotoxicity in rats. Dox (15?mg/kg) was injected intraperitoneally as a single dose, and Def (10?mg/kg) was administered orally for 10?days. Dox showed cardiotoxicity as evidenced by increased heart rate, elevated ST segment, prolonged QTc interval, and increased T wave amplitude. In addition, Dox enhanced aconitine cardiotoxicity by decreasing its dose, producing ventricular tachycardia. Administration of Def significantly attenuated Dox-induced electrocardiographic changes. Cardiotoxicity of Dox was confirmed biochemically by a significant elevation in serum creatine kinase-MB and lactate dehydrogenase activities as well as by myocardial malondialdehyde and reduced glutathione contents. Moreover, Dox caused a significant decrease in myocardial superoxide dismutase activity. Administration of Def significantly attenuated the biochemical changes. These results suggest that Def might be a potential cardioprotective agent against Dox-induced cardiotoxicity.     

Gamma proteobacteria can nodulate legumes of the genus Hedysarum

The bacteria hosted in the root nodules of the three Mediterranean wild legume species Hedysarum carnosum, Hedysarum spinosissimum subsp. capitatum, and Hedysarum pallidum, growing in native stands in different habitats in Algeria were isolated. Bacteria were recovered on yeast-mannitol-agar or on minimal media from a total of 52 nodules. Isolates were analyzed by Amplified Ribosomal DNA Restriction Analysis (ARDRA) using the enzyme CfoI, and further sorted by RAPD fingerprinting. A total of ten different types were found and their amplified 16S rDNA was sequenced and compared to databases. The BLAST alignment indicates that all the species whose sequences share 98 to 100% identity to the bacteria found in these nodules belong to the class Gammaproteobacteria and include Pantoea agglomerans, Enterobacter kobei, Enterobacter cloacae, Leclercia adecarboxylata, Escherichia vulneris, and Pseudomonas sp. No evidence of any rhizobial-like sequence was found even upon amplifying from the bulk of microbial cells obtained from the squashed nodules, suggesting that the exclusive occupants of the nodules formed by the three plants tested are members of the orders Enterobacteriales or Pseudomonadales. This is the first report of Gammaproteobacteria associated with legume nodules. Despite the presence of the related crop plant Hedysarum coronarium, specifically nodulated by Rhizobium sullae, these three Hedysarum species demonstrate to have undergone a separate path in terms of endophytic interactions with bacteria. An hypothesis to account for differences between the symbiotic relationships engaged by man-managed legumes, and those found in plants whose ecology is independent from human action, is discussed.     

Testosterone Trajectories and Reference Ranges in a Large Longitudinal Sample of Male Adolescents

Purpose

Pubertal dynamics plays an important role in physical and psychological development of children and adolescents. We aim to provide reference ranges of plasma testosterone in a large longitudinal sample. Furthermore, we describe a measure of testosterone trajectories during adolescence that can be used in future investigations of development.

Methods

We carried out longitudinal measurements of plasma testosterone in 2,216 samples obtained from 513 males (9 to 17 years of age) from the Avon Longitudinal Study of Parents and Children. We used integration of a model fitted to each participant’s testosterone trajectory to calculate a measure of average exposure to testosterone over adolescence. We pooled these data with corresponding values reported in the literature to provide a reference range of testosterone levels in males between the ages of 6 and 19 years.

Results

The average values of total testosterone in the ALSPAC sample range from 0.82 nmol/L (Standard Deviation [SD]: 0.09) at 9 years of age to 16.5 (SD: 2.65) nmol/L at 17 years of age; these values are congruent with other reports in the literature. The average exposure to testosterone is associated with different features of testosterone trajectories such as Peak Testosterone Change, Age at Peak Testosterone Change, and Testosterone at 17 years of age as well as the timing of the growth spurt during puberty.

Conclusions

The average exposure to testosterone is a useful measure for future investigations using testosterone trajectories to examine pubertal dynamics.     

New quinoxaline 1,4-di-N-oxides. Part 1: Hypoxia-selective cytotoxins and anticancer agents derived from quinoxaline 1,4-di-N-oxides

Hypoxic cells which are common feature of solid tumors are resistant to both anticancer drugs and radiation therapy. Thus, the identification of drugs with the selective toxicity toward hypoxic cells is an important target in anticancer chemotherapy. Tirapazamine has been shown to be an efficient and selective cytotoxin after bioreductive activation in hypoxic cells which is thought to be due to the presence of the 1,4-di-N-oxide. A new series of quinoxaline 1,4-di-N-oxides and fused quinoxaline di-N-oxides were synthesized and evaluated for hypoxic-cytotoxic activity on EAC cell line. Compound 10a was the most potent cytotoxin IC(50) 0.9 microg/mL, potency 75 microg/mL, and was approximately 15 times more selective cytotoxin (HCR>111) than 3-aminoquinoxaline-2-carbonitrile which has been used as a standard (HCR>7.5). Compounds 4 and 3a,b were more selective than the standard. In addition, antitumor activity against Hepg2 (liver) and U251 (brain) human cell lines was evaluated, compounds 9c and 8a were the most active against Hepg2 with IC(50) values 1.9 and 2.9 microg/mL, respectively, however, all the tested compounds were nontoxic against U251 cell line.     

Lipoplex size determines lipofection efficiency with or without serum

In order to identify factors affecting cationic liposome-mediated gene transfer, the relationships were examined among cationic liposome/DNA complex (lipoplex)-cell interactions, lipoplex size and lipoplex-mediated transfection (lipofection) efficiency. It was found that lipofection efficiency was determined mainly by lipoplex size, but not by the extent of lipoplex-cell interactions including binding, uptake or fusion. In addition, it was found that serum affected mainly lipoplex size, but not lipoplex-cell interactions, which effect was the major reason behind the inhibitory effect of serum on lipofection efficiency. It was concluded that, in the presence or absence of serum, lipoplex size is a major factor determining lipofection efficiency. Moreover, in the presence or absence of serum, lipoplex size was found to affect lipofection efficiency by controlling the size of the intracellular vesicles containing lipoplexes after internalization, but not by affecting lipoplex-cell interactions. In addition, large lipoplex particles showed, in general, higher lipofection efficiency than small particles. These results imply that, by controlling lipoplex size, an efficient lipid delivery system may be achieved for in vitro and in vivo gene therapy.     

MaGIC: a program to generate targeted marker sets for genome-wide association studies

High-throughput genotyping technologies such as DNA pooling and DNA microarrays mean that whole-genome screens are now practical for complex disease gene discovery using association studies. Because it is currently impractical to use all available markers, a subset is typically selected on the basis of required saturation density. Restricting markers to those within annotated genomic features of interest (e.g., genes or exons) or within feature-rich regions, reduces workload and cost while retaining much information. We have designed a program (MaGIC) that exploits genome assembly data to create lists of markers correlated with other genomic features. Marker lists are generated at a user-defined spacing and can target features with a user-defined density. Maps are in base pairs or linkage disequilibrium units (LDUs) as derived from the International HapMap data, which is useful for association studies and fine-mapping. Markers may be selected on the basis of heterozygosity and source database, and single nucleotide polymorphism (SNP) markers may additionally be selected on the basis of validation status. The import function means the method can be used for any genomic features such as housekeeping genes, long interspersed elements (LINES), or Alu repeats in humans, and is also functional for other species with equivalent data. The program and source code is freely available at http://cogent.iop.kcl.ac.uk/MaGIC.cogx.     

TIMP-1 Inhibits Apoptosis in Lung Adenocarcinoma Cells via Interaction with Bcl-2

Tissue inhibitors of metalloproteinases (TIMPs) are multifaceted molecules that exhibit properties beyond their classical proteinase inhibitory function. Although TIMP-1 is a known inhibitor of apoptosis in mammalian cells, the mechanisms by which it exerts its effects are not well-established. Our earlier studies using H2009 lung adenocarcinoma cells, implanted in the CNS, showed that TIMP-1 overexpressing H2009 cells (HB-1), resulted in more aggressive tumor kinetics and increased vasculature. The present study was undertaken to elucidate the role of TIMP-1 in the context of apoptosis, using the same lung cancer cell lines. Overexpressing TIMP-1 in a lung adenocarcinoma cell line H2009 resulted in an approximately 3-fold increased expression of Bcl-2, with a marked reduction in apoptosis upon staurosporine treatment. This was an MMP-independent function as a clone expressing TIMP-1 mutant T2G, lacking MMP inhibition activity, inhibited apoptosis as strongly as TIMP1 overexpressing clones, as determined by inhibition of PARP cleavage. Immunoprecipitation of Bcl-2 from cell lysates also co-immunoprecipitated TIMP-1, indicative of an interaction between these two proteins. This interaction was specific for TIMP-1 as TIMP-2 was not present in the Bcl-2 pull-down. Additionally, we show a co-dependency of TIMP-1 and Bcl-2 RNA and protein levels, such that abrogating Bcl-2 causes a downregulation of TIMP-1 but not TIMP-2. Finally, we demonstrate that TIMP-1 dependent inhibition of apoptosis occurs through p90RSK, with phosphorylation of the pro-apoptotic protein BAD at serine 112, ultimately reducing Bax levels and increasing mitochondrial permeability. Together, these studies define TIMP-1 as an important cancer biomarker and demonstrate the potential TIMP-1 as a crucial therapeutic target.     

Nanostructured lipid carriers as semisolid topical delivery formulations for diflucortolone valerate

Context: Topical treatment of skin disease needs to be strategic to ensure high drug concentration in the skin with minimum systemic absorption.

Objective: The aim of this study was to produce semisolid nanostructured lipid carrier (NLC) formulations, for topical delivery of the corticosteroid drug, diflucortolone valerate (DFV), with minimum systemic absorption.

Method: NLC formulations were developed using a high shear homogenization combined with sonication, using Precirol® ATO5 or Tristearin® as the solid lipid, Capryol? or isopropyl myristate as the liquid lipid and Poloxamer® 407 as surfactant. The present study addresses the influence of different formulations composition as solid lipid, liquid lipid types and concentrations on the physicochemical properties and drug release profile from NLCs.

Results and discussion: DFV-loaded NLC formulations possessed average particle size ranging from 160.40?nm to 743.7?nm with narrow polydispersity index. The encapsulation efficiency was improved by adding the lipid-based surfactants (Labrasol® and Labrafil® M1944CS) to reach 68%. The drug release from the investigated NLC formulations showed a prolonged release up to 12?h. The dermatopharmacokinetic study revealed an improvement in drug deposition in the skin with the optimized DFV-loaded NLC formulation, in contrast to a commercial formulation.

Conclusion: NLC provides a promising nanocarrier system that work as reservoir for targeting topical delivery of DFV.     

First report of molecular diagnosis of Tunisian hemophiliacs A: identification of 8 novel causative mutations

ABSTRACT: INTRODUCTION: Hemophilia A is an X linked recessive hemorrhagic disorder caused by mutations in the F8 gene that lead to qualitative and/or quantitative deficiencies of coagulation factor VIII (FVIII). Molecular diagnosis of hemophilia A is challenging because of the high number of different causative mutations that are distributed throughout the large F8 gene. Molecular studies of these mutations are essential in order to reinforce our understanding of their pathogenic effect responsible for the disorder. Aim In this study we have performed molecular analysis of 28 Tunisian hemophilia A patients and analyzed the F8 mutation spectrum. METHODS: We screened the presence of intron 22 and intron 1 inversion in severe hemophilia A patients by southern blotting and polymerase chain reaction (PCR). Detection of point mutations was performed by dHPLC/sequencing of the coding F8 gene region. We predict the potential functional consequences of novel missense mutations with bioinformatics approaches and mapping of their spatial positions on the available FVIII 3D structure. RESULTS: We identified 23 different mutations in 28 Tunisian hemophilia A patients belonging to 22 unrelated families. The identified mutations included 5 intron 22 inversions, 7 insertions, 4 deletions and 7 substitutions. In total 18 point mutations were identified, of which 9 are located in exon 14, the most mutated exonic sequence in the F8 gene. Among the 23 mutations, 8 are novel and not deposited in the HAMSTeRS database nor described in recently published articles. CONCLUSION: The mutation spectrum of Tunisian hemophilia A patients is heterogeneous with the presence of some characteristic features. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1693269827490715.