1,513 research outputs found

    Drugs Behaviour and the Brain Chemistry

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    Drugs affect the hundreds of billions of molecules that make up our brains, our 'universe within'. Molecules serve as chemical 'messengers' which circulate through the body until they encounter other molecules on the surface of the cells which fit their specific configuration. The molecules carrying information- are called 'neurotransmitters'. They react with other molecules called 'neuroreceptors', which modify the response to the information in the neurotransmitters by interacting the way a key fits into a lock. Thus, information is passed from cell to cell. Molecular'recognition sites' integrate the individual cells of the body, and together they make the person a unique individua

    Estudos radiométricos sobre a oxidação de (U-14C) L-aminoácidos por micobactérias sensíveis e resistentes a drogas

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    A radiometric assay system has been used to study oxidation patterns of (U-14C) L-amino acids by drug-susceptible and drug-resistant mycobacteria. Drug-susceptible M. tuberculosis (H37Rv TMC 102 and Erdman) along with the drug-resistant organism M. tuberculosis (H37 Rv TMC 303), M. bovis, M. avium, M. intracellulare, M. kansasii and M. chelonei were used. The organisms were inoculated into a sterile reaction system with liquid 7H9 medium and one of the (U-14C) L-amino acids. Each organism displayed a different pattern of amino acid oxidation, but these patterns were not distinctive enough for identification of the organism. Complex amino acids such as proline, phenylalanine and tyrosine were of no use in identification of mycobacteria, since virtually all organisms failed to oxidize them. There was no combination of substrates able to separate susceptible from resistant organisms.Um sistema radiométrico foi utilizado para estudar os padrões de oxidação dos (U-14C) L-aminoácidos por micobactérias sensíveis e resis tentes a drogas. Foram usadas duas cepas do M. tuberculosis sensíveis a todas as drogas, H37Rv e Erdman. As micobactérias resistentes foram M. tuberculosis H37Rv resistente a 5 ug/ml de hidrazida, M. bovis, M. avium, M. intracellulare, M. kansasii e M. chelonei. As micobac térias foram inoculadas em frascos estéreis contendo o meio líquido 7H9 e um dos (U-14C) L-aminoácidos. Cada micobactéria apresentou um padrão de oxidação de aminoácidos, mas estes padrões não foram suficientemente diferentes para identificá-la. Aminoácidos complexos como a prolina, fenilalanina e tirosina não tiveram utilidade na identificação das micobactérias, pois praticamente todos os microorganismos foram incapazes de oxidá-los. Nenhuma combinação de aminoácidos foi capaz de separar as micobactérias sensíveis das resistentes a drogas

    Imaging-guided chest biopsies: techniques and clinical results

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    Background This article aims to comprehensively describe indications, contraindications, technical aspects, diagnostic accuracy and complications of percutaneous lung biopsy. Methods Imaging-guided biopsy currently represents one of the predominant methods for obtaining tissue specimens in patients with lung nodules; in many cases treatment protocols are based on histological information; thus, biopsy is frequently performed, when technically feasible, or in case other techniques (such as bronchoscopy with lavage) are inconclusive. Results Although a coaxial system is suitable in any case, two categories of needles can be used: fine-needle aspiration biopsy (FNAB) and core-needle biopsy (CNB), with the latter demonstrated to have a slightly higher overall sensitivity, specificity and accuracy. Conclusion Percutaneous lung biopsy is a safe procedure even though a few complications are possible: pneumothorax, pulmonary haemorrhage and haemoptysis are common complications, while air embolism and seeding are rare, but potentially fatal complications

    A Comparison of Bilateral Breast Cancers in <i>BRCA</i> Carriers

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    Abstract Background: Women with breast cancer and a BRCA mutation have a high risk of developing a contralateral breast cancer. It is generally believed that the two cancers represent independent events. However, the extent of concordance between the first and second tumors with respect to hormone receptor expression and other pathologic features is unknown. Purpose: To determine the degree of concordance of estrogen receptor (ER) status, tumor grade, and histology in tumors from women with bilateral breast cancer and a BRCA mutation. Subjects and Methods: Women with a history of bilateral invasive breast cancers were selected from an international registry of women with BRCA1 or BRCA2 mutations. Medical records were reviewed to document the characteristics of each cancer and the treatments received. Results: Data were available for 286 women with bilateral breast cancer and a BRCA mutation (211 BRCA1; 75 BRCA2). The mean interval between first and second tumor was 5.1 years. The two tumors were concordant more often than expected for ER status (P &lt; 0.0001) and for grade (P &lt; 0.0001), but not for histology (P = 0.55). The ER status of the first tumor was highly predictive of the ER status of the second tumor (odds ratio, 8.7; 95% confidence interval, 3.5-21.5; P &lt; 0.0001). Neither age, menopausal status, oophorectomy nor tamoxifen use was predictive of the ER status of the second tumor. Conclusions: There is strong concordance in ER status and tumor grade between independent primary breast tumors in women with a BRCA mutation. The excess concordance may be due to common risk factors, genetic variation, or the existence of a preneoplastic lesion that is common to both tumors

    Risk-shifting Through Issuer Liability and Corporate Monitoring

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    This article explores how issuer liability re-allocates fraud risk and how risk allocation may reduce the incidence of fraud. In the US, the apparent absence of individual liability of officeholders and insufficient monitoring by insurers under-mine the potential deterrent effect of securities litigation. The underlying reasons why both mechanisms remain ineffective are collective action problems under the prevailing dispersed ownership structure, which eliminates the incentives to moni-tor set by issuer liability. This article suggests that issuer liability could potentially have a stronger deterrent effect when it shifts risk to individuals or entities holding a larger financial stake. Thus, it would enlist large shareholders in monitoring in much of Europe. The same risk-shifting effect also has implications for the debate about the relationship between securities litigation and creditor interests. Credi-tors’ claims should not be given precedence over claims of defrauded investors (e.g., because of the capital maintenance principle), since bearing some of the fraud risk will more strongly incentivise large creditors, such as banks, to monitor the firm in jurisdictions where corporate debt is relatively concentrated

    Genetic Variants in HSD17B3, SMAD3, and IPO11 Impact Circulating Lipids in Response to Fenofibrate in Individuals With Type 2 Diabetes

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    Individuals with type 2 diabetes (T2D) and dyslipidemia are at an increased risk of cardiovascular disease. Fibrates are a class of drugs prescribed to treat dyslipidemia, but variation in response has been observed. To evaluate common and rare genetic variants that impact lipid responses to fenofibrate in statin-treated patients with T2D, we examined lipid changes in response to fenofibrate therapy using a genomewide association study (GWAS). Associations were followed-up using gene expression studies in mice. Common variants in SMAD3 and IPO11 were marginally associated with lipid changes in black subjects (P < 5 x 10(-6)). Rare variant and gene expression changes were assessed using a false discovery rate approach. AKR7A3 and HSD17B13 were associated with lipid changes in white subjects (q < 0.2). Mice fed fenofibrate displayed reductions in Hsd17b13 gene expression (q < 0.1). Associations of variants in SMAD3, IPO11, and HSD17B13, with gene expression changes in mice indicate that transforming growth factor-beta (TGF-) and NRF2 signaling pathways may influence fenofibrate effects on dyslipidemia in patients with T2D

    Circularly polarized electroluminescence from silicon nanostructures heavily doped with boron

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    The circularly polarized electroluminescence (CPEL) from silicon nanostructures which are the p-type ultra-narrow silicon quantum well (Si-QW) confined by {\delta}-barriers heavily doped with boron, 5 10^21 cm^-3, is under study as a function of temperature and excitation levels. The CPEL dependences on the forward current and temperature show the circularly polarized light emission which appears to be caused by the exciton recombination through the negative-U dipole boron centers at the Si-QW {\delta}-barriers interface

    Genetic Variants in \u3cem\u3eHSD17B3\u3c/em\u3e, \u3cem\u3eSMAD3\u3c/em\u3e, and \u3cem\u3eIPO11\u3c/em\u3e Impact Circulating Lipids in Response to Fenofibrate in Individuals With Type 2 Diabetes

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    Individuals with type 2 diabetes (T2D) and dyslipidemia are at an increased risk of cardiovascular disease. Fibrates are a class of drugs prescribed to treat dyslipidemia, but variation in response has been observed. To evaluate common and rare genetic variants that impact lipid responses to fenofibrate in statin‐treated patients with T2D, we examined lipid changes in response to fenofibrate therapy using a genomewide association study (GWAS). Associations were followed‐up using gene expression studies in mice. Common variants in SMAD3 and IPO11 were marginally associated with lipid changes in black subjects (P \u3c 5 × 10‐6). Rare variant and gene expression changes were assessed using a false discovery rate approach. AKR7A3 and HSD17B13 were associated with lipid changes in white subjects (q \u3c 0.2). Mice fed fenofibrate displayed reductions in Hsd17b13 gene expression (q \u3c 0.1). Associations of variants in SMAD3, IPO11, and HSD17B13, with gene expression changes in mice indicate that transforming growth factor‐beta (TGF‐β) and NRF2 signaling pathways may influence fenofibrate effects on dyslipidemia in patients with T2D
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