Potent Phototoxicity of Marine Bunker Oil to Translucent Herring Embryos after Prolonged Weathering

Pacific herring embryos (Clupea pallasi) spawned three months following the Cosco Busan bunker oil spill in San Francisco Bay showed high rates of late embryonic mortality in the intertidal zone at oiled sites. Dead embryos developed to the hatching stage (e.g. fully pigmented eyes) before suffering extensive tissue deterioration. In contrast, embryos incubated subtidally at oiled sites showed evidence of sublethal oil exposure (petroleum-induced cardiac toxicity) with very low rates of mortality. These field findings suggested an enhancement of oil toxicity through an interaction between oil and another environmental stressor in the intertidal zone, such as higher levels of sunlight-derived ultraviolet (UV) radiation. We tested this hypothesis by exposing herring embryos to both trace levels of weathered Cosco Busan bunker oil and sunlight, with and without protection from UV radiation. Cosco Busan oil and UV co-exposure were both necessary and sufficient to induce an acutely lethal necrotic syndrome in hatching stage embryos that closely mimicked the condition of dead embryos sampled from oiled sites. Tissue levels of known phototoxic polycyclic aromatic compounds were too low to explain the observed degree of phototoxicity, indicating the presence of other unidentified or unmeasured phototoxic compounds derived from bunker oil. These findings provide a parsimonious explanation for the unexpectedly high losses of intertidal herring spawn following the Cosco Busan spill. The chemical composition and associated toxicity of bunker oils should be more thoroughly evaluated to better understand and anticipate the ecological impacts of vessel-derived spills associated with an expanding global transportation network

Spectrophotometric determination of tizanidine and orphenadrine via ion pair complex formation using eosin Y

A simple, sensitive and rapid spectrophotometric method was developed and validated for the determination of two skeletal muscle relaxants namely, tizanidine hydrochloride (I) and orphenadrine citrate (II) in pharmaceutical formulations. The proposed method is based on the formation of a binary complex between the studied drugs and eosin Y in aqueous buffered medium (pH 3.5). Under the optimum conditions, the binary complex showed absorption maxima at 545 nm for tizanidine and 542 nm for orphenadrine. The calibration plots were rectilinear over concentration range of 0.5-8 μg/mL and 1-12 μg/mL with limits of detection of 0.1 μg/mL and 0.3 μg/mL for tizanidine and orphenadrine respectively. The different experimental parameters affecting the development and stability of the complex were studied and optimized. The method was successfully applied for determination of the studied drugs in their dosage forms; and to the content uniformity test of tizanidine in tablets

ICAR: endoscopic skull‐base surgery

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Periodontal bone loss and risk of epithelial ovarian cancer

PURPOSE: Periodontitis, a chronic inflammatory response to pathogenic bacteria in the oral microbiome, is common among adults. It is associated with several medical conditions, including cardiovascular diseases, and potentially with esophageal, lung, oral and pancreatic cancer. One of the proposed mechanisms behind these associations is systemic inflammation, which has also been implicated in ovarian cancer etiology. The aim of this study was to evaluate association between ovarian cancer and periodontal bone loss. METHODS: The association between periodontal bone loss, a marker of periodontitis, and risk of epithelial ovarian cancer was estimated among 60,560 participants of the prospective Nurses’ Health Study using Cox proportional hazards analysis. Competing risks analysis was used to estimate association by histological subtype. RESULTS: We did not observe an increased risk of ovarian cancer among participants with periodontal bone loss (HR=0.86, 95% CI: 0.64–1.15). Among women younger than 69 years, periodontal bone loss was associated with a 40% (HR=0.60, 95% CI: 0.36–0.98) decreased ovarian cancer risk, while there was no association in women older than 69 (HR=1.09, 95% CI: 0.75–1.58), although this difference did not reach statistical significance (p-heterogeneity=0.06). We observed a suggestive decreased risk for serous tumors (HR=0.76, 95% CI: 0.53–1.09). The number of natural teeth and root canals, other metrics of oral health, were not associated with ovarian cancer risk. CONCLUSION: Our results do not support an increased ovarian cancer risk in women with periodontal bone loss, however there was a significant decrease in risk in women younger than 69. Given the unexpected association between periodontal bone loss and ovarian cancer risk in younger women, further research is warranted