PubMed · 14219213
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N L CHAYET. 1965-01-07. MALPRACTICE--A RECENT CASE.. https://doi.org/10.1056/nejm196501072720109
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The occurrence of polycyclic aromatic hydrocarbons (PAHs) in five samples of olive pomace oil has been studied to determine the contamination degree of this type of oil and to evaluate if specific purification steps must be introduced during its manufacture. The PAHs present have been determined by gas chromatography-mass spectrometry. A high number of PAHs, with a wide range of molecular weights and in very high concentrations, have been found in four of the samples studied. A very high number of alkyl derivatives and, in many cases, in higher concentrations than their respective parent PAHs, have also been identified. One of the samples, however, presents a more reduced number of PAHs and in significantly lower concentrations than the others. These findings reveal that it is necessary to introduce adequate cleanup steps in the manufacturing process of olive pomace oil, which can give rise to oils with a relatively low content of PAHs. Some carcinogenic PAHs have also been identified, both unalkylated and alkylated.
The neutrophil-attracting chemokine interleukin 8 (IL-8) is stored in the Weibel-Palade body (WPB) of endothelial cells (ECs) from which it can be rapidly released after exposure to the secretagogues histamine or thrombin. In this manner, IL-8 may enable rapid recruitment of leukocytes to inflammatory sites. To explore the possible storage of EC-derived chemokines that may attract other subsets of leukocytes, we examined the intracellular localization and secretagogue responsiveness of growth-related oncogene alpha (GROalpha), monocyte chemoattractant protein-1 (MCP-1), eotaxin-3, interferon-gamma-inducible protein 10 (IP-10), and regulated on activation, normal T-cell expressed and secreted (RANTES). While eotaxin-3, GROalpha, and MCP-1 were rapidly released from ECs, the release of the T-cell attractors RANTES and IP-10 was not sensitive to the secretagogues. Moreover, of the 3 former chemokines, only eotaxin-3 was stored in WPBs. GROalpha and MCP-1 resided mainly in smaller vesicles compatible with sorting to a different, histamine-responsive compartment, which has been described in ECs although not reported to contain chemokines. In conclusion, we propose that rapid release of chemokines is restricted to those primarily recruiting leukocytes of the innate immune system, and that their storage in ECs is not restricted to the WPB compartment.
CONTEXT: Sunlight is the main environmental cause of most cutaneous melanomas. Exposure to intense bursts of ultraviolet radiation, especially in childhood, starts the transformation of benign melanocytes into a malignant phenotype. Paradoxically, outdoor workers have a decreased risk of melanoma compared with indoor workers, suggesting that chronic sunlight exposure can have a protective effect. Further, some melanomas form on sun-exposed regions; others do not. Although some melanomas arise from pre-existing melanocytic naevi (moles), many arise de novo. These observations suggest that melanoma arises from multiple pathways, with initiating and promoting factors differing for each. STARTING POINT: Janet Maldonado and colleagues recently studied the distribution of BRAF gene mutations in 115 patients with invasive primary melanomas (J Natl Cancer Inst 2003; 95: 1878-80). These researchers found that BRAF mutations were statistically significantly more common in melanomas occurring on intermittently sun-exposed skin than elsewhere. By contrast, BRAF mutations in melanomas on chronically sun-damaged skin were rare. These findings strongly suggest that distinct genetic pathways lead to melanoma. WHERE NEXT? The study of gene-environment interactions is clearly the next arena for epidemiological research into melanoma. The recent identification of polymorphisms in the melanocortin-1 receptor could open up an avenue of investigation into a molecular distinction between those individuals whose melanomas arise on chronic sun-exposed skin from those in whom tumours will develop on sun-protected skin or from melanocytic naevi. If a dual pathway for melanoma is supported by other investigations, public-health messages can be tailored to the population at risk.