Management of Multiple Head and Neck Paragangliomas With Assistance of a 3-D Model.

INTRODUCTION: Extirpation of multiple head and neck paragangliomas carries challenge due to close anatomic relationships with critical neurovascular bundles. OBJECTIVES: This study aims to assess whether the application of 3-D models can assist with surgical planning and treatment of these paragangliomas, decrease surgically related morbidity and mortality. METHODS: Fourteen patients undergoing surgical resection of multiple head and neck paragangliomas were enrolled in this study. A preoperative 3-D model was created based on radiologic data, and relevant critical anatomic relationships were preoperatively assessed and intraoperatively validated. RESULTS: All 14 patients presented with multiple head and neck paragangliomas, including bilateral carotid body tumors (CBT, n = 9), concurrent CBT with glomus jugulare tumors (GJT, n = 4), and multiple vagal paragangliomas (n = 1). Ten patients underwent genomic analysis and all harbored succinate dehydrogenase complex subunit D (SDHD) mutations. Under guidance of the 3-D model, the internal carotid artery (ICA) was circumferentially encased by tumor on 5 of the operated sides, in 4 (80%) of which the tumor was successfully dissected out from the ICA, whereas ICA reconstruction was required on one side (20%). Following removal of CBT, anterior rerouting of the facial nerve was avoided in 3 (75%) of 4 patients during the extirpation of GJT with assistance of a 3-D model. Two patients developed permanent postoperative vocal cord paralysis. There was no vessel rupture or mortality in this study cohort. CONCLUSION: The 3-D model is beneficial for establishment of a preoperative strategy, as well as planning and guiding the intraoperative procedure for resection of multiple head and neck paragangliomas.

Characteristics of dissolved organic matter in urban road runoff under different traffic densities in Beijing, China.

The characteristics of dissolved organic matter (DOM) in road runoff under different traffic densities were compared using resin fractionation, molecular weight distribution analysis, three-dimensional excitation-emission matrix fluorescence spectroscopy, and UV-visible spectroscopy. Heavy traffic density strongly increased the concentration of DOM in road runoff, resulting in higher dissolved organic carbon. The distribution of molecular weights in DOM was not influenced by the traffic. DOM was dominated by colloidal organic matter with molecular weight in the 1 kDa to 0.45 µm size range. Hydrophobic fractions accounted for a large proportion than hydrophilic fractions in DOM, and hydrophobic acids increased with higher traffic density. Traffic density did not alter the fluorescent substances in DOM, including fulvic-like UV fluorescent substances and protein-like substances. However, more tryptophan-like protein substances were found in DOM from road runoff with heavy traffic. Moreover, the aromatization degree of DOM was not affected by heavy traffic, while the degree of humification decreased.

Novel label-free electrochemical strategy for sensitive determination of ten-eleven translocation protein 1.

A label-free electrochemical method was developed for sensitive determination of ten-eleven translocation protein 1 (TET1) which can mediate the demethylation of DNA. This strategy is mainly based on MspI-mediated restriction endonuclease reaction. Current response difference of the biosensor before and after cleavage by MspI was dependent on the activity and concentration of TET1. With the aid of Au nanoparticles, this method shows a good linear range from 0.0042 µg µL-1 to 0.0210 µg µL -1 with a correlation coefficient of 0.9350 and a low limit of detection 0.00098 µg µL -1. Finally, this method was used to investigate the effects of n-oxalylglycine (NOG) and taxol on activity of TET1. The results indicated that NOG could inhibit TET1 activity but taxol could not. So this electrochemical biosensor could be applied to TET activity evaluation and inhibitor screening in field of biomedicine and clinical diagnosis.

[Characteristics of Chemical Fractions of Dissolved Organic Matter in Road Runoff in Beijing].

The characteristics of DOM chemical fractions in road runoff with different traffic density were analyzed using excitation emission matrix spectroscopy (EEMs) technology, UV-vis spectra, and FTIR spectroscopy. The results showed that hydrophobic organics were the dominant components in DOM of road runoff, and hydrophobic neutral organics was the most abundant fraction. The hydrophilic organics in DOM of road runoff were mainly composed of protein-like substances. Both protein-like substances and fulvic-like acid substances were found in the hydrophobic organic matters. A high degree of aromatization and a low degree of humification were detected in hydrophobic organics, whereas the characteristics of hydrophilic organics were opposite. Some functional groups such as isomerized carboxyl and unsaturated C=C bonds were featured in acidic organics, and ether and ester groups, phenol, and alcohol were detected in alkaline and neutral organics. The substance composition and characteristics of DOM chemical fractions in road runoff were not affected by the traffic density. Traffic density influenced the quantity of substances in each chemical fraction only. With traffic density increasing, the matter content and the aromatization degree of DOM chemical fractions in road runoff increased, whereas the degree of humification decreased.

The influence of traffic density on heavy metals distribution in urban road runoff in Beijing, China.

The concentrations, potential risk, and distributions of heavy metals in urban road runoff from different traffic density were determined and compared in Beijing, China. It showed that the concentrations of heavy metals in road runoff were strongly influenced by traffic density, resulting in total concentrations of Cu, Zn, Fe, Mn, and Pb in the runoff from highway higher than those from the road nearby campus. The potential ecological risk of heavy metals in the runoff from highway was higher than those from the road nearby campus. The distributions of heavy metals were not influenced by the traffic density. Cu, Zn, Cr, Cd, Pb, and Mn in road runoff transported predominantly in particulate-bound form and the dissolved form mainly distributed in colloidal fraction (1 kDa to 0.45 µm). Traffic density did not change the speciation of heavy metals in the road runoff, in which Cr and Zn mainly expressed in organic colloidal fraction while Fe, Mn, Cd, Pb, and Cu expressed in inorganic colloidal fraction. The traffic activities would contribute to the strong correlations between Fe, Zn, Mn, Cr, and Pb because of the similar sources.