The analysis of oral air using selected ion flow tube mass spectrometry in persons with and without a history of oral malodour

Abstract: Objectives: Oral malodour is a common disorder predominantly caused by bacterial metabolism of food stuffs in the mouth. It is routinely diagnosed and monitored by either the subjective rating or the measurement of oral volatile sulphur compound (VSC) levels. Non‐sulphur compounds are also believed to contribute significantly to the condition although there is currently no direct means to assess their levels. In this study, we utilized selective flow tube mass spectrometry (SIFT‐MS) to measure, in real time, a range of sulphur and non‐sulphur containing compounds in oral air to determine whether the technique can be used to objectively monitor oral malodour. Methods: Oral malodour was assessed using organoleptic scores in subjects with and without a history of oral malodour (n = 18) by a trained rater, while the chemical composition of oral air was analysed by both VSC sensor and SIFT‐MS. Results: Total VSC levels were significantly correlated with levels of hydrogen sulphide and methylmercaptan measured by SIFT‐MS, but not with organoleptic scores. In subjects with elevated organoleptic score, only levels of methylmercaptan were significantly elevated. In three subjects with elevated tongue organoleptic scores but normal total VSC levels, SIFT‐MS suggested that one subject possessed high levels of oral acetone while another had high oral levels of acetic acid. Conclusions: Our data suggest that SIFT‐MS can be used to assess a wide range of compounds in oral air in addition to VSC to provide a clearer picture of the chemical nature of malodour. This may assist in the diagnosis and monitoring of the condition.     

儿童输注ABO主侧不合血小板的效果弱于输注血型相合的血小板

由于血小板只有5天的保存期,库存压力导致经常输注ABO血型不合的血小板.为了避免血小板过期,首先输注的是库存时间最长的血小板,包括输注ABO血型不合的血小板.AABB和英国血液学标准委员会建议,输注红细胞时必须要求ABO主侧相合,而输注血小板并没有要求ABO血型匹配.     

盐酸放线瑞香宁的紫外二阶导数光谱法测定及在兔体内的药代动力学

盐酸放线瑞香宁(actinodaphine-HCl)系从莲叶桐科青藤属植物黑吹风(Illigera khasiana C.B Clarke)中分离提取而得的有效成分,结构式如图1。药理试验证明有解热、镇痛、解痉等作用。本文报告用紫外二阶导数光谱法研究盐酸放线瑞香宁在兔体内的药代动力学结果。家兔4只,体重2.8±0.6kg。盐酸放线瑞香宁由本所植化室提供。氯仿、乙醇均为A.R。Perkin-Elmer型紫外—可见光分光光度计系美国产品。     

Gastrointestinal teratomas: CT and US appearance with pathologic correlation

Gastrointestinal teratomas are uncommon, benign neoplasms that occur primarily in children. A retrospective review of five cases (two gastric, one pancreatic, one mesenteric, and one in the lesser omentum) is presented with emphasis on the computed tomographic and ultrasonographic appearances. Principal findings are a well-defined mass with separate cystic and solid components of varying proportions, discrete areas with densities similar to that of fat, or coarse, globular calcifications within the solid component. Recognition of these findings may allow the radiologist to make a correct preoperative diagnosis of teratoma.