109 research outputs found

    Evidence for different mechanisms of 'unhooking' for melphalan and cisplatin-induced DNA interstrand cross-links in vitro and in clinical acquired resistant tumour samples

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    DNA interstrand cross-links (ICLs) are critical lesions produced by several cancer chemotherapy agents including platinum drugs and nitrogen mustards. We have previously shown in haematological (multiple myeloma) and solid tumours (ovarian cancer) that clinical sensitivity to such agents can result from a defect in DNA ICL processing leading to their persistence. Conversely, enhanced repair can result in clinical acquired resistance following chemotherapy. The repair of ICLs is complex but it is assumed that the 'unhooking' step is common to all ICLs

    A Database of Wing Diversity in the Hawaiian Drosophila

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    Background. Within genus Drosophila, the endemic Hawaiian species offer some of the most dramatic examples of morphological and behavioral evolution. The advent of the Drosophila grimshawi genome sequence permits genes of interest to be readily cloned from any of the hundreds of species of Hawaiian Drosophila, offering a powerful comparative approach to defining molecular mechanisms of species evolution. A key step in this process is to survey the Hawaiian flies for characters whose variation can be associated with specific candidate genes. The wings provide an attractive target for such studies: Wings are essentially two dimensional, and genes controlling wing shape, vein specification, pigment production, and pigment pattern evolution have all been identified in Drosophila. Methodology/Principal Findings. We present a photographic database of over 180 mounted, adult wings from 73 species of Hawaiian Drosophila. The image collection, available at FlyBase.org, includes 53 of the 112 known species of picture wing\u27\u27 Drosophila, and several species from each of the other major Hawaiian groups, including the modified mouthparts, modified tarsus, antopocerus, and haleakalae (fungus feeder) groups. Direct image comparisons show that major wing shape changes can occur even between closely related species, and that pigment pattern elements can vary independently of each other. Among the 30 species closest to grimshawi, diverse visual effects are achieved by altering a basic pattern of seven wing spots. Finally, we document major pattern variations within species, which appear to result from reduced diffusion of pigment precursors through the wing blade. Conclusions/Significance. The database highlights the striking variation in size, shape, venation, and pigmentation in Hawaiian Drosophila, despite their generally low levels of DNA sequence divergence. In several independent lineages, highly complex patterns are derived from simple ones. These lineages offer a promising model system to study the evolution of complexity

    Portuguese validation of FACES-IV in adult children caregivers facing parental cancer

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    The purpose of the present study was to examine the psychometric properties of the FACES-IV in Portuguese caregivers of cancer patients. In this cross-sectional study, a sample of 214 adult children caregivers of cancer patients receiving chemotherapy, completed FACES-IV, Family Communication Scale (FCS), Family Satisfaction Scale (FSS), and Satisfaction with Social Support Scale (SSSS). Internal consistencies above .70 were found for all FACES-IV scales, except for Enmeshed and Rigid scales, as well as for the FCS, FSS, and SSSS (except for Intimacy). Strong correlations between FACES-IV and the validation scales FCS and FSS were found except for the Enmeshed and Rigid scales. Confirmatory analysis yielded an acceptable model for the six theoretical subscales. The discriminant analysis between problematic and non-problematic family systems showed results similar to the original study. These findings suggest that FACES-IV is a valid measure of family functioning in oncological family caregiving’s contexts.Acknowledgments This study was funded by a grant from the Portuguese Foundation for Science and Technology (reference SFRH/BD/43275/2008)

    Dental therapy before and after radiotherapy–an evaluation on patients with head and neck malignancies

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    The present investigation evaluates the dental care situation of patients with head and neck cancer before and after radiotherapy. The situations of these patients in 1993 and 2005 were compared to detect similarities, differences and developments. In the years 1993 and 2005, 37 and 36 patients, respectively, with head and neck cancer treated by the local departments of otorhinolaryngology and of radiotherapy were examined consecutively according to their aftercare appointments. Time points of radiotherapy treatment of the patients evaluated in 1993 varied from 1984 to 1993. The patients evaluated in 2005 had received radiotherapy between 1998 and 2005. Therefore the applied radiotherapeutic regimen differed not only between the two groups of patients, but also within each group. The information for these investigations was provided anonymously. It was evaluated with descriptive statistics. The evaluation of the data shows distinct differences with respect to preventive and therapeutic dental care measures. In 2005, 35 out of 36 patients (97.2%) had a dental consultation before radiotherapy (1993, 65%). All 27 dentate patients (100%) obtained a splint for fluoride application (1993, none). 29% fewer edentulous patients were seen than in 1993. The number of teeth destroyed decreased from 19.2% (1993) to 7.8% in 2005. Mycoses due to Candida spp. and chronic failures in wound healing were rare (5.5%). In the course of the 12 years, prophylactic measures, such as the application of splints for fluoride treatment, were intensified. However, concepts for the dental care of patients undergoing radiotherapy, especially following the radiation, should be widened to avoid ruined teeth and long delayed wound healings

    Lack of cortico-limbic coupling in bipolar disorder and schizophrenia during emotion regulation

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    Bipolar disorder (BD) and schizophrenia (Sz) share dysfunction in prefrontal inhibitory brain systems, yet exhibit distinct forms of affective disturbance. We aimed to distinguish these disorders on the basis of differential activation in cortico-limbic pathways during voluntary emotion regulation. Patients with DSM-IV diagnosed Sz (12) or BD-I (13) and 15 healthy control (HC) participants performed a well-established emotion regulation task while undergoing functional magnetic resonance imaging. The task required participants to voluntarily upregulate or downregulate their subjective affect while viewing emotionally negative images or maintain their affective response as a comparison condition. In BD, abnormal overactivity (hyperactivation) occurred in the right ventrolateral prefrontal cortex (VLPFC) during up- and downregulation of negative affect, relative to HC. Among Sz, prefrontal hypoactivation of the right VLPFC occurred during downregulation (opposite to BD), whereas upregulation elicited hyperactivity in the right VLPFC similar to BD. Amygdala activity was significantly related to subjective negative affect in HC and BD, but not Sz. Furthermore, amygdala activity was inversely coupled with the activity in the left PFC during downregulation in HC (r=−0.76), while such coupling did not occur in BD or Sz. These preliminary results indicate that differential cortico-limbic activation can distinguish the clinical groups in line with affective disturbance: BD is characterized by ineffective cortical control over limbic regions during emotion regulation, while Sz is characterized by an apparent failure to engage cortical (hypofrontality) and limbic regions during downregulation

    Sequential morphological characteristics of murine fetal liver hematopoietic microenvironment in Swiss Webster mice

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    Embryonic hematopoiesis occurs via dynamic development with cells migrating into various organs. Fetal liver is the main hematopoietic organ responsible for hematopoietic cell expansion during embryologic development. We describe the morphological sequential characteristics of murine fetal liver niches that favor the settlement and migration of hematopoietic cells from 12 days post-coitum (dpc) to 0 day post-partum. Liver sections were stained with hematoxylin and eosin, Lennert’s Giemsa, Sirius Red pH 10.2, Gomori’s Reticulin, and Periodic Acid Schiff/Alcian Blue pH 1.0 and pH 2.5 and were analyzed by bright-field microscopy. Indirect imunohistochemistry for fibronectin, matrix metalloproteinase-1 (MMP-1), and MMP-9 and histochemistry for naphthol AS-D chloroacetate esterase (NCAE) were analyzed by confocal microscopy. The results showed that fibronectin was related to the promotion of hepatocyte and trabecular differentiation; reticular fibers did not appear to participate in fetal hematopoiesis but contributed to the physical support of the liver after 18 dpc. During the immature phase, hepatocytes acted as the fundamental stroma for the erythroid lineage. The appearance of myeloid cells in the liver was related to perivascular and subcapsular collagen, and NCAE preceded MMP-1 expression in neutrophils, an occurrence that appeared to contribute to their liver evasion. Thus, the murine fetal liver during ontogenesis shows two different phases: one immature and mainly endodermic (<14 dpc) and the other more developed (endodermic-mesenchymal; >15 dpc) with the maturation of hepatocytes, a better definition of trabecular pattern, and an increase in the connective tissue in the capsule, portal spaces, and liver parenchyma. The decrease of hepatic hematopoiesis (migration) coincides with hepatic maturation

    Genome-Wide Association Study SNPs in the Human Genome Diversity Project Populations: Does Selection Affect Unlinked SNPs with Shared Trait Associations?

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    Genome-wide association studies (GWAS) have identified more than 2,000 trait-SNP associations, and the number continues to increase. GWAS have focused on traits with potential consequences for human fitness, including many immunological, metabolic, cardiovascular, and behavioral phenotypes. Given the polygenic nature of complex traits, selection may exert its influence on them by altering allele frequencies at many associated loci, a possibility which has yet to be explored empirically. Here we use 38 different measures of allele frequency variation and 8 iHS scores to characterize over 1,300 GWAS SNPs in 53 globally distributed human populations. We apply these same techniques to evaluate SNPs grouped by trait association. We find that groups of SNPs associated with pigmentation, blood pressure, infectious disease, and autoimmune disease traits exhibit unusual allele frequency patterns and elevated iHS scores in certain geographical locations. We also find that GWAS SNPs have generally elevated scores for measures of allele frequency variation and for iHS in Eurasia and East Asia. Overall, we believe that our results provide evidence for selection on several complex traits that has caused changes in allele frequencies and/or elevated iHS scores at a number of associated loci. Since GWAS SNPs collectively exhibit elevated allele frequency measures and iHS scores, selection on complex traits may be quite widespread. Our findings are most consistent with this selection being either positive or negative, although the relative contributions of the two are difficult to discern. Our results also suggest that trait-SNP associations identified in Eurasian samples may not be present in Africa, Oceania, and the Americas, possibly due to differences in linkage disequilibrium patterns. This observation suggests that non-Eurasian and non-East Asian sample populations should be included in future GWAS
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