Development of pyridine-containing macrocyclic copper(II) complexes: potential role in the redox modulation of oxaliplatin toxicity in human breast cells

The unique redox and catalytic chemistry of Cu has justified the development of novel Cu complexes for different therapeutic uses including cancer therapy. In this work, four pyridine-containing aza-macrocyclic copper(II) complexes were prepared (CuL1-CuL4) varying in ring size and/or substituents and their superoxide scavenging activity evaluated. CuL3, the most active superoxide scavenger, was further studied as a modulator of the cytotoxicity of oxaliplatin in epithelial breast MCF10A cells and in MCF7 breast cancer cells. Our results show that CuL3 enhances the therapeutic window of oxaliplatin, by both protecting non-tumour cells and increasing its cytotoxic effect in breast carcinoma cells. CuL3 is thus a promising complex to be further studied and to be used as a lead compound for the optimization of novel chemotherapy sensitizers.     

Essential role of the czc determinant for cadmium, cobalt and zinc resistance in Gluconacetobacter diazotrophicus PAl 5

The mechanisms of cadmium, cobalt and zinc resistance were characterized in the plant-growth-promoting bacterium Gluconacetobacter diazotrophicus PAl 5. The resistance level of the wild-type strain was evaluated through the establishment of minimum inhibitory concentrations (MIC) of the soluble compounds CdCl2·H2O, CoCl2·6H2O and ZnCl2. Gluconacetobacter diazotrophicus PAl 5 was resistant to high concentrations of Cd, Co and Zn, with MICs of 1.2, 20 and 20 mM, respectively. Screening of an insertion library from transposon EZ-Tn5 in the presence of ZnO revealed that the mutant GDP30H3 was unable to grow in the presence of the compound. This mutant was also highly sensitive to CdCl2·H2O, CoCl2·6H2O and ZnCl2. Molecular characterization established that the mutation affected the czcA gene, which encodes a protein involved in metal efflux. In silico analysis showed that czcA is a component of the czcCBARS operon together with four other genes. This work provides evidence of the high tolerance of G. diazotrophicus PAl 5 to heavy metals and that czc is a determinant for metal resistance in this bacterium.     

Chromosome Numbers and Karyotypes of Species of Vernonia sect. Lepidaploa (Asteraceae: Vernonieae)

Vernonia is the largest genus of the tribe Vernonieae (Asteraceae) and comprises more than 1,000 species. In the present study we explore chromosome number and karyotype variation of eight species treated within different subsections of the section Vernonia sect. Lepidaploa. We aimed to explore if these data support the recognition of a single large genus (sensu Baker) or favor its splitting into 22 small genera (sensu Robinson). The species were collected in ??cerrado??, rupicolous and disturbed areas in the states of S?o Paulo and Minas Gerais, Brazil. Chromosome numbers varied from 2n?=?32 to 60. Most chromosomes were small, and the karyotype analysis revealed a predominance of metacentric and some submetacentric chromosomes. The karyotype symmetry in Vernonia was moderate (TF% 32.2 to 45.9), with the most symmetrical karyotype observed in V. rubriramea. The results obtained here did not conclusively support any of the taxonomic proposals for Vernonia due to the absence of distinctive or characteristic karyotype patterns for any of the taxonomic groupings, i.e., sections and subsections (sensu Baker) or new genera (sensu Robinson). Nevertheless, a tenuous relationship was observed between the chromosome numbers reported in the literature, those recorded here, and the taxonomic alterations suggested by Robinson for the genera Lessingianthus, Chrysolaena, and Vernonanthura that were originally part of Vernonia sensu Baker.     

Frequency and aetiology of dermatophytosis in children age 12 and under in the state of Amazonas,Brazil

BackgroundFew scientific studies have evaluated dermatophytosis among children in the state of Amazonas or in the greater northern region of Brazil.AimsThe aim of this study was to research the frequency and aetiology of dermatophytosis in children age 12 and under, who were seen between March 1996 and November 2005 at the Mycology Laboratory of the National Institute of Amazonian Research.MethodsFor mycological diagnoses, epidermal scales and/or hairs were used. A portion of this material was treated with potassium hydroxide for direct examination, and another portion was cultivated in Mycobiotic Agar for the isolation of dermatophytes.ResultsOf the 590 samples analysed, 210 showed positive diagnoses by direct examination and cultivation. Tinea capitis (153 cases) was the most frequent type of dermatophytosis, and Trichophyton tonsurans (121 cases) was the most frequently isolated fungal agent. Tinea corporis was observed in 48 cases where the most frequently isolated fungal agent was also T. tonsurans (17 cases), and the corporal regions most affected were the face, arms and trunk. The laboratory confirmed tinea pedis in 6 cases, and the principal fungal agents isolated were Trichophyton rubrum (3) and Trichophyton mentagrophytes (3). The presence of tinea cruris was confirmed in 3 cases, and T. rubrum, T. tonsurans and Epidermophyton floccosum were isolated from these cases.ConclusionsThe children examined were primarily affected by tinea capitis, and the main fungal agent for this dermatophytosis was T. tonsurans.     

Decreased premotor cortex volume in victims of urban violence with posttraumatic stress disorder

Background

Studies addressing posttraumatic stress disorder (PTSD) have demonstrated that PTSD patients exhibit structural abnormalities in brain regions that relate to stress regulation and fear responses, such as the hippocampus, amygdala, anterior cingulate cortex, and ventromedial prefrontal cortex. Premotor cortical areas are involved in preparing to respond to a threatening situation and in representing the peripersonal space. Urban violence is an important and pervasive cause of human suffering, especially in large urban centers in the developing world. Violent events, such as armed robbery, are very frequent in certain cities, and these episodes increase the risk of PTSD. Assaultive trauma is characterized by forceful invasion of the peripersonal space; therefore, could this traumatic event be associated with structural alteration of premotor areas in PTSD?

Methodology/Principal Findings

Structural magnetic resonance imaging scans were acquired from a sample of individuals that had been exposed to urban violence. This sample consisted of 16 PTSD patients and 16 age- and gender-matched controls. Psychometric questionnaires differentiated PTSD patients from trauma-exposed controls with regard to PTSD symptoms, affective, and resilience predispositions. Voxel-based morphometric analysis revealed that, compared with controls, the PTSD patients presented significant reductions in gray matter volume in the ventral premotor cortex and in the pregenual anterior cingulate cortex.

Conclusions

Volume reduction in the premotor cortex that is observed in victims of urban violence with PTSD may be associated with a disruption in the dynamical modulation of the safe space around the body. The finding that PTSD patients presented a smaller volume of pregenual anterior cingulate cortex is consistent with the results of other PTSD neuroimaging studies that investigated different types of traumatic events.     

Sexual Dimorphism in Sturnira lilium (Chiroptera,Phyllostomidae): Can Pregnancy and Pup Carrying Be Responsible for Differences in Wing Shape?

Competition is one of the most cited mechanisms to explain secondary sexual dimorphism in animals. Nonetheless, it has been proposed that sexual dimorphism in bat wings is also a result of adaptive pressures to compensate additional weight caused by fetus or pup carrying during the reproductive period of females. The main objective of this study is to verify the existence of sexual dimorphism in Sturnira lilium wings. We employed geometric morphometrics techniques using anatomical landmarks superimposition to obtain size (Centroid Size) and shape variables of wings, which were reduced by Linear Discriminant Analysis (LDA). We also employed classical morphometrics using wing length measurements to compare efficiency between these two morphometric approaches and make comparisons using wing area measurements. LDA indicated significant differences between wing shapes of males and females, with 91% (stepwise classification) and 80% (leave-one-out cross validation) of correct classification. However, the size variable obtained did not contribute to such classifications. We have observed larger areas in female wings, but we found no differences in wing length measurements and no allometric effects in wing length, shape and area measurements. Interestingly, our study has provided evidences of morphological differences where classical morphometrics have failed. LDA and area measurements analyses revealed that females have a different area distribution in distinct portions of the wing, with wider dactylopatagia and plagiopatagia, and wingtips more triangular than males. No differences in body length or relative wing length were observed between the sexes, but pregnant females have more body weight than non-pregnant females and males. Our findings suggest that sexual dimorphism in the wing shape of S. lilium is probably related to the increase in flight efficiency of females during reproductive period. It decreases wing loading in specific portions of the wing and reduces energy cost to maintain a faster and maneuverable flight.     

Performance of LBSap Vaccine after Intradermal Challenge with L. infantum and Saliva of Lu. longipalpis: Immunogenicity and Parasitological Evaluation

In the last decade, the search for new vaccines against canine visceral leishmaniasis has intensified. However, the pattern related to immune protection during long periods after experimental infection in vaccine trials is still not fully understood. Herein, we investigated the immunogenicity and parasitological levels after intradermal challenge with Leishmania infantum plus salivary gland extract in dogs immunized with a vaccine composed of L. braziliensis antigens plus saponin as an adjuvant (LBSap vaccine). The LBSap vaccine elicited higher levels of total anti-Leishmania IgG as well as both IgG1 and IgG2. Furthermore, dogs vaccinated had increased levels of lymphocytes, particularly circulating B cells (CD21⁺) and both CD4⁺ and CD8⁺ T lymphocytes. LBSap also elicited an intense in vitro cell proliferation associated with higher levels of CD4⁺ T lymphocytes specific for vaccine soluble antigen and soluble lysate of L. infantum antigen even 885 days after experimental challenge. Furthermore, LBSap vaccinated dogs presented high IFN-γ and low IL-10 and TGF-β1 expression in spleen with significant reduction of parasite load in this tissue. Overall, our results validate the potential of LBSap vaccine to protect against L. infantum experimental infection and strongly support further evaluation of efficiency of LBSap against CVL in natural infection conditions.     

Moniliophthora perniciosa Necrosis- and Ethylene-Inducing Protein 2 (MpNep2) as a Metastable Dimer in Solution: Structural and Functional Implications

Understanding how Nep-like proteins (NLPs) behave during the cell cycle and disease progression of plant pathogenic oomycetes, fungi and bacteria is crucial in light of compelling evidence that these proteins play a role in Witches` Broom Disease (WBD) of Theobroma cacao, one of the most important phytopathological problems to afflict the Southern Hemisphere. The crystal structure of MpNep2, a member of the NLP family and the causal agent of WBD, revealed the key elements for its activity. This protein has the ability to refold after heating and was believed to act as a monomer in solution, in contrast to the related homologs MpNep1 and NPP from the oomyceteous fungus Phytophthora parasitica. Here, we identify and characterize a metastable MpNep2 dimer upon over-expression in Escherichia coli using different biochemical and structural approaches. We found using ultra-fast liquid chromatography that the MpNep2 dimer can be dissociated by heating but not by dilution, oxidation or high ionic strength. Small-angle X-ray scattering revealed a possible tail-to-tail interaction between monomers, and nuclear magnetic resonance measurements identified perturbed residues involved in the putative interface of interaction. We also explored the ability of the MpNep2 monomer to refold after heating or chemical denaturation. We observed that MpNep2 has a low stability and cooperative fold that could be an explanation for its structure and activity recovery after stress. These results can provide new insights into the mechanism for MpNep2′s action in dicot plants during the progression of WBD and may open new avenues for the involvement of NLP- oligomeric species in phytopathological disorders.     

Scaling-up of dental pulp stem cells isolated from multiple niches

Dental pulp (DP) can be extracted from child's primary teeth (deciduous), whose loss occurs spontaneously by about 5 to 12 years. Thus, DP presents an easy accessible source of stem cells without ethical concerns. Substantial quantities of stem cells of an excellent quality and at early (2-5) passages are necessary for clinical use, which currently is a problem for use of adult stem cells. Herein, DPs were cultured generating stem cells at least during six months through multiple mechanical transfers into a new culture dish every 3-4 days. We compared stem cells isolated from the same DP before (early population, EP) and six months after several mechanical transfers (late population, LP). No changes, in both EP and LP, were observed in morphology, expression of stem cells markers (nestin, vimentin, fibronectin, SH2, SH3 and Oct3/4), chondrogenic and myogenic differentiation potential, even after cryopreservation. Six hours after DP extraction and in vitro plating, rare 5-bromo-2'-deoxyuridine (BrdU) positive cells were observed in pulp central part. After 72 hours, BrdU positive cells increased in number and were found in DP periphery, thus originating a multicellular population of stem cells of high purity. Multiple stem cell niches were identified in different zones of DP, because abundant expression of nestin, vimentin and Oct3/4 proteins was observed, while STRO-1 protein localization was restricted to perivascular niche. Our finding is of importance for the future of stem cell therapies, providing scaling-up of stem cells at early passages with minimum risk of losing their "stemness".     

Long-term occupational exposure to organic solvents affects color vision, contrast sensitivity and visual fields

The purpose of this study was to evaluate the visual outcome of chronic occupational exposure to a mixture of organic solvents by measuring color discrimination, achromatic contrast sensitivity and visual fields in a group of gas station workers. We tested 25 workers (20 males) and 25 controls with no history of chronic exposure to solvents (10 males). All participants had normal ophthalmologic exams. Subjects had worked in gas stations on an average of 9.6±6.2 years. Color vision was evaluated with the Lanthony D15d and Cambridge Colour Test (CCT). Visual field assessment consisted of white-on-white 24–2 automatic perimetry (Humphrey II-750i). Contrast sensitivity was measured for sinusoidal gratings of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 and 20.0 cycles per degree (cpd). Results from both groups were compared using the Mann–Whitney U test. The number of errors in the D15d was higher for workers relative to controls (p<0.01). Their CCT color discrimination thresholds were elevated compared to the control group along the protan, deutan and tritan confusion axes (p<0.01), and their ellipse area and ellipticity were higher (p<0.01). Genetic analysis of subjects with very elevated color discrimination thresholds excluded congenital causes for the visual losses. Automated perimetry thresholds showed elevation in the 9°, 15° and 21° of eccentricity (p<0.01) and in MD and PSD indexes (p<0.01). Contrast sensitivity losses were found for all spatial frequencies measured (p<0.01) except for 0.5 cpd. Significant correlation was found between previous working years and deutan axis thresholds (rho = 0.59; p<0.05), indexes of the Lanthony D15d (rho = 0.52; p<0.05), perimetry results in the fovea (rho = −0.51; p<0.05) and at 3, 9 and 15 degrees of eccentricity (rho = −0.46; p<0.05). Extensive and diffuse visual changes were found, suggesting that specific occupational limits should be created.