830 research outputs found

    Differences in the Cognitive Skills of Bonobos and Chimpanzees

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    While bonobos and chimpanzees are both genetically and behaviorally very similar, they also differ in significant ways. Bonobos are more cautious and socially tolerant while chimpanzees are more dependent on extractive foraging, which requires tools. The similarities suggest the two species should be cognitively similar while the behavioral differences predict where the two species should differ cognitively. We compared both species on a wide range of cognitive problems testing their understanding of the physical and social world. Bonobos were more skilled at solving tasks related to theory of mind or an understanding of social causality, while chimpanzees were more skilled at tasks requiring the use of tools and an understanding of physical causality. These species differences support the role of ecological and socio-ecological pressures in shaping cognitive skills over relatively short periods of evolutionary time

    The plight of the sense-making ape

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    This is a selective review of the published literature on object-choice tasks, where participants use directional cues to find hidden objects. This literature comprises the efforts of researchers to make sense of the sense-making capacities of our nearest living relatives. This chapter is written to highlight some nonsensical conclusions that frequently emerge from this research. The data suggest that when apes are given approximately the same sense-making opportunities as we provide our children, then they will easily make sense of our social signals. The ubiquity of nonsensical contemporary scientific claims to the effect that humans are essentially--or inherently--more capable than other great apes in the understanding of simple directional cues is, itself, a testament to the power of preconceived ideas on human perception

    Sensorineural hearing loss after concurrent chemoradiotherapy in nasopharyngeal cancer patients

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    <p>Abstract</p> <p>Background</p> <p>Sensorineural hearing loss (SNHL) is one of the major long term side effects from radiation therapy (RT) in nasopharyngeal cancer (NPC) patients. This study aims to review the incidences of SNHL when treating with different radiation techniques. The additional objective is to determine the relationship of the SNHL with the radiation doses delivered to the inner ear.</p> <p>Methods</p> <p>A retrospective cohort study of 134 individual ears from 68 NPC patients, treated with conventional RT and IMRT in combination with chemotherapy from 2004-2008 was performed. Dosimetric data of the cochlea were analyzed. Significant SNHL was defined as > 15 dB increase in bone conduction threshold at 4 kHz and PTA (pure tone average of 0.5, 1, 2 kHz). Relative risk (RR) was used to determine the associated factors with the hearing threshold changes at 4 kHz and PTA.</p> <p>Results</p> <p>Median audiological follow up time was 14 months. The incidence of high frequency (4 kHz) SNHL was 44% for the whole group (48.75% in the conventional RT, 37% with IMRT). Internal auditory canal mean dose of > 50 Gy had shown a trend to increase the risk of high frequency SNHL (RR 2.02 with 95% CI 1.01-4.03, p = 0.047).</p> <p>Conclusion</p> <p>IMRT and radiation dose limitation to the inner ear appeared to decrease SNHL.</p

    The PRMT1 gene expression pattern in colon cancer

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    The methylation of arginine has been implicated in many cellular processes, such as regulation of transcription, mRNA splicing, RNA metabolism and transport. The enzymes responsible for this modification are the protein arginine methyltransferases. The most abundant methyltransferase in human cells is protein arginine methyltransferase 1. Methylation processes appear to interfere in the emergence of several diseases, including cancer. During our study, we examined the expression pattern of protein arginine methyltransferase 1 gene in colon cancer patients. The emerging results showed that the expression of one of the gene variants is associated with statistical significant probability to clinical and histological parameters, such as nodal status and stage. This is a first attempt to acquire an insight on the possible relation of the expression pattern of protein arginine methyltransferase 1 and colon cancer progression

    Clinical course and prognosis of the lymphoproliferative disease of granular lymphocytes. A multicenter study.

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    Lymphoproliferative disease of granular lymphocytes (LDGL) is a recently recognized, relatively rare atypical lymphocytosis characterized by the presence of over 2000 lymphocytes with cytoplasmic azurophilic granules/mm3 in the peripheral blood. The clinical course is heterogeneous, varying from spontaneous regression to progressive, malignant disease. As a consequence, clinical intervention is not standardized. In a worldwide multicenter study, the authors observed 151 patients with LDGL for a mean follow-up time of 29 months. Forty-three patients were asymptomatic at the time of diagnosis. In the remaining cases, clinical symptoms included fever (41 cases), infections (58), neutropenia (47), anemia (17), and thrombocytopenia (12). In 69 cases, LDGL coexisted with an associated disease. Most patients had a nonprogressive clinical course despite the presence of severe symptoms. In 19 patients, death related to LDGL occurred within 48 months. The authors investigated which features at diagnosis were significantly associated with increased mortality. In the univariate analysis, lymph node and liver enlargement, fever at presentation, skin infiltration, a low (less than or equal to 5000/mm3) or high (greater than 20,000/mm3) peripheral leukocyte count, relatively low (less than or equal to 3000) or high (greater than 7000/mm3) absolute peripheral granular lymphocyte (GL) count, and a low (less than or equal to 15%) percentage of HNK-1-positive cells were found to be predictors of increased mortality. In the multivariate analysis, significant independent predictors were fever at diagnosis, a low (less than or equal to 15%) percentage of HNK-1-positive peripheral blood mononuclear cells (PBMC) and a relatively low (less than or equal to 3000) GL count. These results showed that about 25% of the patients with LDGL were diagnosed after a routine blood count and had no clinical symptoms. The remaining patients were symptomatic, with some experiencing a fatal clinical course. The author's analysis of the significant prognostic features of LDGL may help in understanding the heterogeneous nature of this syndrom

    Conventional and molecular cytogenetics of human non-medullary thyroid carcinoma: characterization of eight cell line models and review of the literature on clinical samples

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    <p>Abstract</p> <p>Background</p> <p>Cell lines are often poorly characterized from a genetic point of view, reducing their usefulness as tumor models. Our purpose was to assess the genetic background of eight commonly used human thyroid carcinoma models and to compare the findings with those reported for primary tumors of the gland.</p> <p>Methods</p> <p>We used chromosome banding analysis and comparative genomic hybridization to profile eight non-medullary thyroid carcinoma cell lines of papillary (TPC-1, FB2, K1 and B-CPAP), follicular (XTC-1) or anaplastic origin (8505C, C643 and HTH74). To assess the representativeness of the findings, we additionally performed a thorough review of cytogenetic (n = 125) and DNA copy number information (n = 270) available in the literature on clinical samples of thyroid carcinoma.</p> <p>Results</p> <p>The detailed characterization of chromosomal markers specific for each cell line revealed two cases of mistaken identities: FB2 was shown to derive from TPC-1 cells, whereas K1 cells have their origin in cell line GLAG-66. All cellular models displayed genomic aberrations of varying complexity, and recurrent gains at 5p, 5q, 8q, and 20q (6/7 cell lines) and losses at 8p, 13q, 18q, and Xp (4/7 cell lines) were seen. Importantly, the genomic profiles were compatible with those of the respective primary tumors, as seen in the meta-analysis of the existing literature data.</p> <p>Conclusion</p> <p>We provide the genomic background of seven independent thyroid carcinoma models representative of the clinical tumors of the corresponding histotypes, and highlight regions of recurrent aberrations that may guide future studies aimed at identifying target genes. Our findings further support the importance of routinely performing cytogenetic studies on cell lines, to detect cross-contamination mishaps such as those identified here.</p

    Insights on the Evolution of Prolyl 3-Hydroxylation Sites from Comparative Analysis of Chicken and Xenopus Fibrillar Collagens

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    Recessive mutations that prevent 3-hydroxyproline formation in type I collagen have been shown to cause forms of osteogenesis imperfecta. In mammals, all A-clade collagen chains with a GPP sequence at the A1 site (P986), except α1(III), have 3Hyp at residue P986. Available avian, amphibian and reptilian type III collagen sequences from the genomic database (Ensembl) all differ in sequence motif from mammals at the A1 site. This suggests a potential evolutionary distinction in prolyl 3-hydroxylation between mammals and earlier vertebrates. Using peptide mass spectrometry, we confirmed that this 3Hyp site is fully occupied in α1(III) from an amphibian, Xenopus laevis, as it is in chicken. A thorough characterization of all predicted 3Hyp sites in collagen types I, II, III and V from chicken and xenopus revealed further differences in the pattern of occupancy of the A3 site (P707). In mammals only α2(I) and α2(V) chains had any 3Hyp at the A3 site, whereas in chicken all α-chains except α1(III) had A3 at least partially 3-hydroxylated. The A3 site was also partially 3-hydroxylated in xenopus α1(I). Minor differences in covalent cross-linking between chicken, xenopus and mammal type I and III collagens were also found as a potential index of evolving functional differences. The function of 3Hyp is still unknown but observed differences in site occupancy during vertebrate evolution are likely to give important clues

    Structures of Helicobacter pylori Shikimate Kinase Reveal a Selective Inhibitor-Induced-Fit Mechanism

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    Shikimate kinase (SK), which catalyzes the specific phosphorylation of the 3-hydroxyl group of shikimic acid in the presence of ATP, is the enzyme in the fifth step of the shikimate pathway for biosynthesis of aromatic amino acids. This pathway is present in bacteria, fungi, and plants but absent in mammals and therefore represents an attractive target pathway for the development of new antimicrobial agents, herbicides, and antiparasitic agents. Here we investigated the detailed structure–activity relationship of SK from Helicobacter pylori (HpSK). Site-directed mutagenesis and isothermal titration calorimetry studies revealed critical conserved residues (D33, F48, R57, R116, and R132) that interact with shikimate and are therefore involved in catalysis. Crystal structures of HpSK·SO4, R57A, and HpSK•shikimate-3-phosphate•ADP show a characteristic three-layer architecture and a conformationally elastic region consisting of F48, R57, R116, and R132, occupied by shikimate. The structure of the inhibitor complex, E114A•162535, was also determined, which revealed a dramatic shift in the elastic LID region and resulted in conformational locking into a distinctive form. These results reveal considerable insight into the active-site chemistry of SKs and a selective inhibitor-induced-fit mechanism
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