Results of the treatment of pediatric osteosarcoma in the Hungarian population

The objective of this report was to estimate long-term outcome and prognostic factors in children and adolescents with osteosarcoma. To evaluate the efficacy of surgery and multiagent chemotherapy for treating osteosarcoma, we reviewed 122 cases (65 males, 57 females, mean age 13.8 ± 3.6 years) treated at the Second Department of Pediatrics in Budapest between 1988 and 2006. Demographic parameters, tumor-related and treatment-related variables, response, overall survival (OS) and event-free survival (EFS) were analyzed. The 5-year OS and EFS were 68% and 61.5%, respectively. OS of patients without metastasis was 79%, while OS with early metastasis was 17%. Survival of patients with amputation (n=30) was not significantly different from that of patients with limb-salvage surgery (n=82), but all patients without radical surgery died. Gender and histological classification had no prognostic significance. Patients with localized tumors in extremities had increased survival compared to those with axial skeleton tumors (p=0.013). Poor histological response to neoadjuvant chemotherapy (rate of survivor tumor cells >10%) was associated with decreased survival (p=0.018). Patients under 14 years had better EFS than patients over 14 years (p=0.008). Our results demonstrate that younger patients with localized osteosarcoma of the extremities who receive limb-salvage surgery and chemotherapy have an excellent survival.     

A neuropsychological perspective on the link between language and praxis in modern humans

Hypotheses about the emergence of human cognitive abilities postulate strong evolutionary links between language and praxis, including the possibility that language was originally gestural. The present review considers functional and neuroanatomical links between language and praxis in brain-damaged patients with aphasia and/or apraxia. The neural systems supporting these functions are predominantly located in the left hemisphere. There are many parallels between action and language for recognition, imitation and gestural communication suggesting that they rely partially on large, common networks, differentially recruited depending on the nature of the task. However, this relationship is not unequivocal and the production and understanding of gestural communication are dependent on the context in apraxic patients and remains to be clarified in aphasic patients. The phonological, semantic and syntactic levels of language seem to share some common cognitive resources with the praxic system. In conclusion, neuropsychological observations do not allow support or rejection of the hypothesis that gestural communication may have constituted an evolutionary link between tool use and language. Rather they suggest that the complexity of human behaviour is based on large interconnected networks and on the evolution of specific properties within strategic areas of the left cerebral hemisphere.     

Accounting for biological variation in differential display two-dimensional electrophoresis experiments

Variation of protein expression levels was investigated in the heart, lung and liver from an inbred (C57/BL6) and an outbred (CD-1) mouse line. Based on the measured inter-individual variation, optimal sample sizes for two-dimensional electrophoresis experiments were determined by means of power analysis. For both lines, the level of protein expression variation was in the range of technical variation. Thus, although the differences in protein expression variation were significant between organs and mouse lines, optimal sample sizes were very similar (between 8 for heart proteins from C57/BL6 and 10 for liver proteins of the same line). Proteins with organ expression bias (higher expression in one organ as compared to the other two organs) exhibited higher variation of expression and the proportion of these proteins in each organ explained at least partly inter-organ differences in protein expression variation. The results suggest that proteomic experiments using more heterogeneous mouse samples would not require much larger sample sizes than those using narrowly standardized samples. Experiment designs encompassing a broader genetic variation and thus affording increased relevance of the results can be accessible to proteomics researchers at still affordable sample sizes.     

Validation study of existing gene expression signatures for anti-TNF treatment in patients with rheumatoid arthritis

So far, there are no means of identifying rheumatoid arthritis (RA) patients who will fail to respond to tumour necrosis factor blocking agents (anti-TNF), prior to treatment. We set out to validate eight previously reported gene expression signatures predicting therapy outcome. Genome-wide expression profiling using Affymetrix GeneChip Exon 1.0 ST arrays was performed on RNA isolated from whole blood of 42 RA patients starting treatment with infliximab or adalimumab. Clinical response according to EULAR criteria was determined at week 14 of therapy. Genes that have been reported to be associated with anti-TNF treatment were extracted from our dataset. K-means partition clustering was performed to assess the predictive value of the gene-sets. We performed a hypothesis-driven analysis of the dataset using eight existing gene sets predictive of anti-TNF treatment outcome. The set that performed best reached a sensitivity of 71% and a specificity of 61%, for classifying the patients in the current study. We successfully validated one of eight previously reported predictive expression profile. This replicated expression signature is a good starting point for developing a prediction model for anti-TNF treatment outcome that can be used in a daily clinical setting. Our results confirm that gene expression profiling prior to treatment is a useful tool to predict anti-TNF (non) response.     

First Initial community-acquired meningitis due to extended-spectrum beta-lactamase producing Escherichia coli complicated with multiple aortic mycotic aneurysms

We report the first case of extended-spectrum beta-lactamase producing E. coli community-acquired meningitis complicated with multiple aortic mycotic aneurysms. Because of the acute aneurysm expansion with possible impending rupture on 2 abdominal CT scan, the patient underwent prompt vascular surgery and broad spectrum antibiotic therapy but he died of a hemorrhagic shock. Extended-spectrum beta-lactamase producing E. coli was identified from both blood and cerebrospinal fluid culture before vascular treatment. The present case report does not however change the guidelines of Gram negative bacteria meningitis in adults.     

Analogues of the frog skin peptide alyteserin‐2a with enhanced antimicrobial activities against Gram‐negative bacteria

The emergence of strains of multidrug‐resistant Gram‐negative bacteria mandates a search for new types of antimicrobial agents. Alyteserin‐2a (ILGKLLSTAAGLLSNL.NH₂) is a cationic, α‐helical peptide, first isolated from skin secretions of the midwife toad, Alytes obstetricans, which displays relatively weak antimicrobial and haemolytic activities. Increasing the cationicity of alyteserin‐2a while maintaining amphipathicity by the substitution Gly¹¹→ Lys enhanced the potency against both Gram‐negative and Gram‐positive bacteria by between fourfold and 16‐fold but concomitantly increased cytotoxic activity against human erythrocytes by sixfold (mean concentration of peptide producing 50% cell death; LC₅₀ = 24 µm ). Antimicrobial potency was increased further by the additional substitution Ser⁷→Lys, but the resulting analogue remained cytotoxic to erythrocytes (LC₅₀ = 38 µm ). However, the peptide containing d ‐lysine at positions 7 and 11 showed high potency against a range of Gram‐negative bacteria, including multidrug‐resistant strains of Acinetobacter baumannii and Stenotrophomonas maltophilia (minimum inhibitory concentration = 8 µm ) but appreciably lower haemolytic activity (LC₅₀ = 185 µm ) and cytotoxicity against A549 human alveolar basal epithelial cells (LC₅₀ = 65 µm ). The analogue shows potential for treatment of nosocomial pulmonary infections caused by bacteria that have developed resistance to commonly used antibiotics. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.     

Conveniently Pre-Tagged and Pre-Packaged: Extended Molecular Identification and Metagenomics Using Complete Metazoan Mitochondrial Genomes

Background

Researchers sorely need markers and approaches for biodiversity exploration (both specimen linked and metagenomics) using the full potential of next generation sequencing technologies (NGST). Currently, most studies rely on expensive multiple tagging, PCR primer universality and/or the use of few markers, sometimes with insufficient variability.

Methodology/Principal Findings

We propose a novel approach for the isolation and sequencing of a universal, useful and popular marker across distant, non-model metazoans: the complete mitochondrial genome. It relies on the properties of metazoan mitogenomes for enrichment, on careful choice of the organisms to multiplex, as well as on the wide collection of accumulated mitochondrial reference datasets for post-sequencing sorting and identification instead of individual tagging. Multiple divergent organisms can be sequenced simultaneously, and their complete mitogenome obtained at a very low cost. We provide in silico testing of dataset assembly for a selected set of example datasets.

Conclusions/Significance

This approach generates large mitogenome datasets. These sequences are useful for phylogenetics, molecular identification and molecular ecology studies, and are compatible with all existing projects or available datasets based on mitochondrial sequences, such as the Barcode of Life project. Our method can yield sequences both from identified samples and metagenomic samples. The use of the same datasets for both kinds of studies makes for a powerful approach, especially since the datasets have a high variability even at species level, and would be a useful complement to the less variable 18S rDNA currently prevailing in metagenomic studies.     

In planta production of the highly potent resveratrol analogue pterostilbene via stilbene synthase and O-methyltransferase co-expression

Resveratrol and related stilbenes are thought to play important roles in defence responses in several plant species and have also generated considerable interest as nutraceuticals owing to their diverse health-promoting properties. Pterostilbene, a 3,5-dimethylether derivative of resveratrol, possesses properties similar to its parent compound and, additionally, exhibits significantly higher fungicidal activity in vitro and superior pharmacokinetic properties in vivo. Recombinant enzyme studies carried out using a previously characterized O-methyltransferase sequence from Sorghum bicolor (SbOMT3) demonstrated its ability to catalyse the A ring-specific 3,5-bis-O-methylation of resveratrol, yielding pterostilbene. A binary vector was constructed for the constitutive co-expression of SbOMT3 with a stilbene synthase sequence from peanut (AhSTS3) and used for the generation of stably transformed tobacco and Arabidopsis plants, resulting in the accumulation of pterostilbene in both species. A reduced floral pigmentation phenotype observed in multiple tobacco transformants was further investigated by reversed-phase HPLC analysis, revealing substantial decreases in both dihydroquercetin-derived flavonoids and phenylpropanoid-conjugated polyamines in pterostilbene-producing SbOMT3/AhSTS3 events. These results demonstrate the potential utility of this strategy for the generation of pterostilbene-producing crops and also underscore the need for the development of additional approaches for minimizing concomitant reductions in key phenylpropanoid-derived metabolites.     

Design, synthesis and evaluation of the inhibitory selectivity of novel trans-resveratrol analogues on human recombinant CYP1A1, CYP1A2 and CYP1B1

A series of trans-stilbene derivatives containing 4'-methylthio substituent were synthesized and evaluated for inhibitory activities on human recombinant cytochrome P450(s): CYP1A1, CYP1A2, and CYP1B1. CYP1A2-related metabolism of stilbene derivatives was estimated by using NADPH oxidation assay. Additionally, for CYP1A2 and CYP1B1 molecular docking analysis was carried out to provide information on enzyme-ligand interactions and putative site of metabolism. 3,4,5-Trimethoxy-4'-methylthio-trans-stilbene, an analogue of DMU-212 (3,4,5,4'-tetramethoxy-trans-stilbene) was an effective inhibitor of all CYP1 enzymes. On the other hand, 2,3,4-trimethoxy-4'-methylthio-trans-stilbene, appeared to be the most selective inhibitor of the isozymes CYP1A1 and CYP1B1, displaying extremely low affinity towards CYP1A2. Molecular modeling suggested that the most probable binding poses of the methylthiostilbene derivatives in CYP1A2 active sites are those with the methylthio substituent directed towards the heme iron. Products of CYP1A2-catalyzed oxidation of 2,4,5-trimethoxy-4'-methylthiostilbene and 3,4,5-trimethoxy-4'-methylthiostilbene were identified as monohydroxylated compounds. Other studied derivatives appeared to be poor substrates of CYP1A2. Structure-activity relationship analysis rendered better understanding of the mechanism of action of xenobiotic-metabolizing enzymes crucial at the early stage of carcinogenesis.