Cognitive aspects of MELAS and CARASAL.

Monogenic diseases, although rare, should be always considered in the diagnostic work up of vascular dementia (VaD), particularly in patients with early onset and a familial history of dementia or cerebrovascular disease. They include, other than CADASIL, Fabry disease, Col4A1-A2 related disorders, which are well recognized causes of VaD, other heritable diseases such as mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) and cathepsin-A related arteriopathy strokes and leukoencephalopathy (CARASAL). MELAS, caused by mtDNA (80% of adult cases m.3243A>G mutations) and more rarely POLG1 mutations, has minimum prevalence of 3.5/100,000. CARASAL, which is caused by mutations in the CTSA gene, has been described in about 19 patients so far. In both these two disorders cognitive features have not been fully explored and are described only in case series or families. This review paper is aimed at providing an update on the clinical manifestations, with particular focus on cognitive aspects, but also neuroradiological and genetic features of these less frequent monogenic diseases associated with VaD.

Combining elemental and immunochemical analyses to characterize diagenetic alteration patterns in ancient skeletal remains.

Bones and teeth are biological archives, but their structure and composition are subjected to alteration overtime due to biological and chemical degradation postmortem, influenced by burial environment and conditions. Nevertheless, organic fraction preservation is mandatory for several archeometric analyses and applications. The mutual protection between biomineral and organic fractions in bones and teeth may lead to a limited diagenetic alteration, promoting a better conservation of the organic fraction. However, the correlation between elemental variations and the presence of organic materials (e.g., collagen) in the same specimen is still unclear. To fill this gap, chemiluminescent (CL) immunochemical imaging analysis has been applied for the first time for collagen localization. Then, Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) and CL imaging were combined to investigate the correlation between elemental (i.e., REE, U, Sr, Ba) and collagen distribution. Teeth and bones from various archeological contexts, chronological periods, and characterized by different collagen content were analyzed. Immunochemical analysis revealed a heterogeneous distribution of collagen, especially in highly degraded samples. Subsequently, LA-ICP-MS showed a correlation between the presence of uranium and rare earth elements and areas with low amount of collagen. The innovative integration between the two methods permitted to clarify the mutual relation between elemental variation and collagen preservation overtime, thus contributing to unravel the effects of diagenetic alteration in bones and teeth.

Acute pulmonary edema in a dog with severe pulmonary valve stenosis: A rare complication after balloon valvuloplasty.

Pulmonic stenosis is a frequent congenital heart disease in dogs, and the treatment of choice is balloon valvuloplasty which is usually safe and successful. The authors describe for the first time a severe complication after balloon valvuloplasty in a five-month-old dog. After effective treatment, with a considerable drop in right ventricular pressures, the dog developed hypoxemia and dyspnea due to pulmonary edema. The dog underwent intensive care and symptoms improved after a few hours of oxygen therapy, continuous positive airway pressure, and furosemide. Although this event is rare, it could have a large impact on patient survival and should be considered in the treatment of severe pulmonary valve stenosis in the future.

Near-infrared hyperspectral imaging (NIR-HSI) and normalized difference image (NDI) data processing: An advanced method to map collagen in archaeological bones.

In the present study, an innovative and highly efficient near-infrared hyperspectral imaging (NIR-HSI) method is proposed to provide spectral maps able to reveal collagen distribution in large-size bones, also offering semi-quantitative estimations. A recently introduced method for the construction of chemical maps, based on Normalized Difference Images (NDI), is declined in an innovative approach, through the exploitation of the NDI values computed for each pixel of the hyperspectral image to localize collagen and to extract information on its content by a direct comparison with known reference samples. The developed approach addresses an urgent issue of the analytical chemistry applied to bioarcheology researches, which rely on well-preserved collagen in bones to obtain key information on chronology, paleoecology and taxonomy. Indeed, the high demand for large-sample datasets and the consequent application of a wide variety of destructive analytical methods led to the considerable destruction of precious bone samples. NIR-HSI pre-screening allows researchers to properly select the sampling points for subsequent specific analyses, to minimize costs and time and to preserve integrity of archaeological bones (which are available in a very limited amount), providing further opportunities to understand our past.

Drought sensitivity of Amazonian carbon balance revealed by atmospheric measurements.

Feedbacks between land carbon pools and climate provide one of the largest sources of uncertainty in our predictions of global climate. Estimates of the sensitivity of the terrestrial carbon budget to climate anomalies in the tropics and the identification of the mechanisms responsible for feedback effects remain uncertain. The Amazon basin stores a vast amount of carbon, and has experienced increasingly higher temperatures and more frequent floods and droughts over the past two decades. Here we report seasonal and annual carbon balances across the Amazon basin, based on carbon dioxide and carbon monoxide measurements for the anomalously dry and wet years 2010 and 2011, respectively. We find that the Amazon basin lost 0.48 ± 0.18 petagrams of carbon per year (Pg C yr(-1)) during the dry year but was carbon neutral (0.06 ± 0.1 Pg C yr(-1)) during the wet year. Taking into account carbon losses from fire by using carbon monoxide measurements, we derived the basin net biome exchange (that is, the carbon flux between the non-burned forest and the atmosphere) revealing that during the dry year, vegetation was carbon neutral. During the wet year, vegetation was a net carbon sink of 0.25 ± 0.14 Pg C yr(-1), which is roughly consistent with the mean long-term intact-forest biomass sink of 0.39 ± 0.10 Pg C yr(-1) previously estimated from forest censuses. Observations from Amazonian forest plots suggest the suppression of photosynthesis during drought as the primary cause for the 2010 sink neutralization. Overall, our results suggest that moisture has an important role in determining the Amazonian carbon balance. If the recent trend of increasing precipitation extremes persists, the Amazon may become an increasing carbon source as a result of both emissions from fires and the suppression of net biome exchange by drought.

Improved apoptotic cell death in drug-resistant non-small-cell lung cancer cells by tumor necrosis factor-related apoptosis-inducing ligand-based treatment.

Since response to platinum-based therapy in non-small-cell lung cancer (NSCLC) is poor, the present study was designed to rationally identify novel drug combinations in cell models including the A549 cell line and the cisplatin-resistant subline A549/Pt, characterized by reduced sensitivity to cisplatin-induced apoptosis and by upregulation of efflux transporters of the ATP binding cassette (ABC) superfamily. Given the molecular features of these cells, we focused on compounds triggering apoptosis through different mechanisms, such as the mitochondria-targeting drug arsenic trioxide and the phenanthridine analog sanguinarine, which induce apoptosis through the extrinsic pathway. Sanguinarine, not recognized by ABC transporters, could overcome cisplatin resistance and, when used in combination with arsenic trioxide, was synergistic in A549 and A549/Pt cells. The arsenic trioxide/sanguinarine cotreatment upregulated genes implicated in apoptosis activation through the extrinsic pathway. Drug combination experiments indicated that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) treatment improved arsenic trioxide/sanguinarine efficacy, a feature associated with a striking apoptosis induction, particularly in the cisplatin-resistant variant. Thus, a synergistic interaction between sanguinarine and arsenic trioxide could be obtained independent of relative cell sensitivity to arsenic trioxide, and an enhanced apoptosis induction could be achieved in combination with TRAIL through modulation of the extrinsic apoptotic pathway. Antitumor activity studies supported the interest of drug combinations including TRAIL in NSCLC, indicating that drug-resistant NSCLC cells can efficiently be killed by the combination of proapoptotic agents. Our results suggest that the molecular changes occurring in treated cells may be exploited to rationally hit surviving cells.

Camptothecin resistance in cancer: insights into the molecular mechanisms of a DNA-damaging drug.

Poisoning of DNA topoisomerase I is the mechanism by which camptothecins interfere with tumor growth. Although the clinical use of camptothecins has had a significant impact on cancer therapy, de novo or acquired clinical resistance to these drugs is common. Clinical resistance to camptothecins is still a poorly understood phenomenon, likely involving pharmacological and tumor-related factors. Experimental models including yeast and mammalian cell cultures suggest three general mechanisms of camptothecin resistance: i) reduced cellular accumulation of drugs, ii) alteration in the structure/expression of topoisomerase I, and iii) alterations in the cellular response to camptothecin-DNA-ternary complex formation. Some lines of evidence have also suggested links between cellular camptothecin resistance, the existence of a subset of tumor-initiating cells and miRNA deregulation. In this regard, a better definition of the molecular events clarifying the regulation of tumorigenesis and gene expression might contribute to gain insight into the molecular mechanisms on the basis of camptothecin resistance of tumors and to identify new molecular tools for targeting cancer cells. The relevance of these mechanisms to clinical drug resistance has not yet been completely defined, but their evaluation in clinical specimens should help to define personalized treatments including camptothecins as single agents or in combination with other cytotoxic and target-specific anticancer agents. The present review focuses on the cellular/ molecular aspects involved in resistance of tumor cells to camptothecins, including the potential role of cancer stem cells and deregulated miRNAs, and on the approaches proposed for overcoming resistance.

Relationship between Helicobacter pylori detection and an increased risk of infection in childhood

The risk of developing gastric cancer is believed to be related to differences among Helicobacter pylori strains and the inflammatory responses mediated by host genetic factors. H. pylori infection is acquired at an early age and in the absence of appropriate antibiotic therapy, it generally persists for life. Tp53 gene regulates the transcription of several cytokines and chemokines involved in innate immunity and its action may be influenced by the presence of different H. pylori strains. The present study aimed to detect H. pylori in pediatric patients, to access Tp53 polymorphism at codon 72 and to correlate such findings with age and histopathological results. Three hundred and forty-two patients were analyzed. DNA from their gastric biopsies was extracted and the detection of H. pylori was performed through polymerase chain reaction assays, urease test and histopathologic examination. Allelic discrimination of SNP rs1042522 (Tp53) was performed by real-time polymerase chain reaction. Our results suggest a possible relationship between the presence of H. pylori and chronic gastritis in children and young patients, and showed a significant association between ageing and positivity for H. pylori. It was verified that patients aged < 10 years were 1.3 times more likely to have infection by H. pylori when compared with those aged > 10 years. Finally, no association was found between Tp53 polymorphisms and the presence of H. pylori.

Novel insights into targeting ATP-binding cassette transporters for antitumor therapy.

ATP-binding cassette (ABC) transporters are a large family of proteins implicated in physiological cellular functions. Selected components of the family play a well-recognized role in extruding conventional cytotoxic antitumor agents and molecularly targeted drugs from cells. Some lines of evidence also suggest links between transporters and tumor cell survival, in part unrelated to efflux. However, the study of the precise mechanisms regulating the function of drug transporters (e.g., posttranslational modifications such as glycosylation) is still in its infancy. A better definition of the molecular events clarifying the regulation of transporter levels including regulation by microRNAs may contribute to provide new molecular tools to target such a family of transporters. The present review focuses on the biological aspects that implicate ABC transporters in resistance of tumor cells, including cancer stem cells. Molecular analysis of well-known preclinical systems as well as of cancer stem cell models supports the notion that ABC transporters represent amenable targets for modulation of the efficacy of antitumor agents endowed with different molecular features. Recent achievements regarding tumor cell biology are expected to provide a rationale for developing novel inhibitors that target ABC transporters implicated in drug resistance.

Predicting prostate cancer at rebiopsies in patients with high-grade prostatic intraepithelial neoplasia: a study on 546 patients.

The aim of this study was to analyse the factors that predict the diagnosis of prostate cancer (PCa) after high-grade prostatic intraepithelial neoplasia (HGPIN). Data from 546 patients with HGPIN submitted up to a 6-month series of three rebiopsies, according to an institutional protocol, were reviewed. PCa has been found in 174 cases (31.8%), in 116 cases at the first and in 58 cases at a further rebiopsy. The risk of finding PCa at the first rebiopsy was correlated with the PSA value and with an anomalous digital rectal examination (DRE) at the time of the initial biopsy; the risk at a subsequent rebiopsy was correlated to the number of cores with HGPIN, with a cutoff of four, and to the ratio with the total number of cores ('PIN density'), with a cutoff of 50%, at the time of initial biopsy. A tailored protocol of controls can be suggested: (a) higher PSA value and/or anomalous DRE: early extended or saturation rebiopsy; (b) number of cores with HGPIN ≥4 and/or PIN density ≥50%: delayed rebiopsy; and (c) no risk factors: PSA and DRE controls.

Tyrosyl-DNA phosphodiesterase 1 targeting for modulation of camptothecin-based treatment.

The targeting of specific DNA repair mechanisms may be a promising strategy to improve the efficacy of antitumor therapy. The cytotoxic effects of the clinically relevant topoisomerase 1 (Top1) poison camptothecins are related to the generation of DNA lesions and tumor cells may be resistant to DNA damaging agents due to increased repair. Tyrosyl- DNA phosphodiesterase 1 (TDP1) is implicated in the repair of strand breaks by removing abortive Top1/DNA complexes. Thus, a role for TDP1 in counteracting DNA damage induced by camptothecins has been proposed. Here, we review the role of TDP1 in DNA repair with particular reference to TDP1 function, its cooperation with other pathways and the development of pharmacological inhibitors.

ABC transporters as potential targets for modulation of drug resistance.

ATP binding cassette transporters are implicated in multidrug resistant phenotypes of tumor cells and may be cancer stem cell markers. Inhibitors of drug efflux pumps represent an emerging group of potentially useful agents for the improvement of antitumor therapy. Here we provide an overview of drug transporter functions and modulation.

Small molecules targeting p53 to improve antitumor therapy.

Small molecules targeting p53 represent an emerging group of potentially useful agents for the improvement of antitumor therapy. These modulators include agents that activate wild-type p53 or reactivate mutant p53 and inhibitors of p53 functions. Preclinical evidences support the interest of combination strategies with conventional antitumor agents.

Exposure to volatile organic compounds in an ethanol and gasoline service station.

The present study was conducted to determine the VOCs concentrations in a service station located in a residential and commercial area in the city of Rio de Janeiro. This is, to our knowledge, the first published determination in Brazil, where both ethanol and ethanol-blended gasoline are used. Electro polished, stainless steel, evacuated canisters were used for sampling. The analysis was performed by gaschromatography with flame ionization detection (CG-FID) and by gas chromatography-mass spectrometry (CG-MS). A total of 80 and 56 compounds were determined in samples collected at the service station and control location, respectively. The most abundant compounds at the service station were in order of decreasing concentration (units: microg m(-3)): 2-methylbutane (1,715.7), 2-methylbut-1-ene (1,043.2), isobutene (758.8), 2-methylprop-1-ene (703.7), 2-methylpentane (492.1), pentadi-1,3-ene (189.7), toluene (157.0), benzene (144.5), but-2-ene (126.3) and m,p-xylene (123.2). A mean concentration of 144.5 microg m(-3) was determined for benzene, this value is about ten times the concentration determined in the control location in this work and about 70 times the value determined in other locations of Rio de Janeiro using charcoal cartridges for the sampling. The mean benzene/toluene ratios are 0.92 and 0.31 in the service station and control location, respectively. Since in Brazil service station workers are employed to fill customer's cars (self-service is not commonly used) the possible risk of cancer of these workers should be evaluated in a future study.

Cellular sensitivity to beta-diketonato complexes of ruthenium(III), chromium(III) and rhodium(III).

The aim of this study was to investigate cellular response to several ruthenium(III), chromium(III) and rhodium(III) compounds carrying bidentate beta-diketonato ligands: [(acac)--acetylacetonate ligand, (tfac)--trifluoroacetylacetonate ligand]. Cell sensitivity studies were performed on several cell lines (A2780, cisplatin-sensitive and -resistant U2-OS and U2-OS/Pt, HeLa, B16) using growth-inhibition assay. Effect of intracellular GSH depletion on cell sensitivity to the agents was analyzed in A2780 cells. Flow cytometry was used to assess apoptosis by Annexin-V-FITC/PI staining, and to analyze induction of caspase-3 activity. Possible DNA binding/damaging affinity was investigated, by inductively coupled mass spectrometry, and by 14C-thymidine / 3H-uridine incorporation assay. Cell sensitivity studies showed that the pattern of sensitivity to Ru(tfac)3 complex of the two cisplatin-sensitive/-resistant osteosarcoma cell lines, U2-OS and U2-OS/Pt, was similar to that of A2780 cells (72 h exposure), with the IC50 being around 40 microM. The growth-inhibitory effect of Ru(acac)3 ranged over 100 microM, while Cr(III) and Rh(III) complexes were completely devoid of antitumor action in vitro. Ru(tfac)3 exhibited strong potential for apoptosis induction on A2780 cells (up to 40%) and caused cell cycle arrest in the S phase as well as decrease of the percent of G1 and G2 cells. Ru(acac)3-induced apoptosis was slightly higher than 10%, whereas activation of caspase-3 in HeLa cells was moderate. DNA binding study revealed that only Cr(acac)3 was capable of binding DNA, while Cr(III) and Ru(III) compounds possess potential to inhibit DNA/RNA synthesis. In conclusion, only Ru(III) complexes showed potential for antitumor action.

Polymorphisms of the TP53 codon 72 and WRN codon 1367 in individuals from Northern Brazil with gastric adenocarcinoma.

Gastric cancer is the second most frequent type of neoplasia and also the second most common cause of death in the world. TP53 codon 72, which produces variant proteins with an arginine (Arg) or proline (Pro), has been reported to be associated with cancers of the lung, oesophagus, stomach and cervix. Werner's syndrome (WS) is a premature ageing disease caused by a mutation in the WRN gene. The WRN protein acts as a DNA helicase and as an exonuclease. WRN codon 1367 produces variant proteins with an Arg or cysteine (Cys). This polymorphism has been studied, in order to understand the clinical impact of the molecular variants in WS and in age-related disorders. In the present study, the TP53 codon 72 and the WRN codon 1367 polymorphisms were investigated in 54 gastric adenocarcinoma patients (31 diffuse-type and 25 intestinal-type) and 54 controls. DNA samples were extracted, and PCR-RFLP was utilised for genotyping TP53 codon 72 and WRN codon 1367. The allele frequencies of the TP53 polymorphism were: Arg=0.74 and Pro=0.26. The allele frequencies of the WRN polymorphism were: Cys=0.73 and Arg=0.27. The crude genotypic frequencies in gastric cancer patients were similar to those of the controls, but in the WRN codon 1367 polymorphisms the mean age tended to be higher in the Arg/Arg genotypes. There also was an association, although not statistically significant, between the presence of Helicobacter pylori and the genotypes Cys/Cys and Cys/Arg and a higher percentage of cardia cancer among the Arg/Arg genotypes, and of non-cardia cancer among genotypes Cys/Cys and Cys/Arg. These findings may be a reflection of differences in the interaction between WRN codon 1367 polymorphisms and local factors in the stomach. To our knowledge, this is the first study to examine a genetic polymorphism of the WRN gene in cancer. The precise mechanisms of action of the TP53 and WRN polymorphisms involved in the aetiopathogeny of this disease need further investigation.

Interleukin-6 polymorphism and Helicobacter pylori infection in Brazilian adult patients with chronic gastritis.

Helicobacter pylori is recognised as the most common cause of chronic active gastritis and this bacterium is also an important pathogenic factor in peptic ulcer disease. The biological factors that influence clinical outcome in H. pylori infection have been extensively studied. In addition to immunological factors in the host, bacterial virulence determinants in H. pylori strains are likely to play a crucial role in gastric cancer development. Singlenucleotide polymorphisms at the 5' flanking region of the interleukin (IL)-6 gene promoter (G or C at -174 base) have been identified and individuals with the G allele at position -174 have been shown to produce higher levels of IL-6 than those with the C/C genotype. The mucosal levels of IL-6 were reported to be increased in H. pylori-associated gastritis. The present study was conducted to examine any relationship between inflammatory cytokine polymorphisms and the inflammatory process in mucosa infected by H. pylori. In our study we did not find any association between the C and G alleles in adult patients with chronic gastritis and inflammatory process in gastric mucosa.

Global gene expression of fission yeast in response to cisplatin.

The cellular response to the antitumor drug cisplatin is complex, and resistance is widespread. To gain insights into the global transcriptional response and mechanisms of resistance, we used microarrays to examine the fission yeast cell response to cisplatin. In two isogenic strains with differing drug sensitivity, cisplatin activated a stress response involving glutathione-S-transferase, heat shock, and recombinational repair genes. Genes required for proteasome-mediated protein degradation were up-regulated in the sensitive strain, whereas genes for DNA damage recognition/repair and for mitotic progression were induced in the resistant strain. The response to cisplatin overlaps in part with the responses to cadmium and the DNA-damaging agent methylmethane sulfonate. The different gene groups involved in the cellular response to cisplatin help the cells to tolerate and repair DNA damage and to overcome cell cycle blocks. These findings are discussed with respect to known cisplatin response pathways in human cells.

Gene expression profiles in the cellular response to a multinuclear platinum complex.

We used cDNA arrays to monitor modulation of mRNA expression after exposure to a multinuclear platinum complex (BBR3464) in a human cervix squamous cell carcinoma cell line (A431) and in a cisplatin-resistant subline (A431/Pt) exhibiting collateral sensitivity to BBR3464. In parental A431cells, the drug induced at least twofold up-regulation of 15 genes including cell cycle and growth regulators, tumor suppressors and signal transduction genes. In cisplatin-resistant A431/Pt cells, BBR3464increased the expression of 15 genes such as apoptosis regulators and genes involved in the DNA damage response. Interestingly, BBR3464induced up-regulation of anti-metastatic factors together with down-regulation of several pro-metastatic factors. Cell cycle analysis indicated a marked G2arrest in treated A431cells, whereas an apoptotic response was documented in A431/Pt cells. These differential patterns of transcriptional profile in sensitive and resistant cells are consistent with a role for cell cycle regulation in the response to BBR3464.