对芸香科芦荟不会发生接触性过敏

芦荟自古就被用作化妆品和药物添加剂，近来更受喜爱。虽应用广泛，但过敏反应罕有报道。作者用芦荟叶的油性提取物、来自整个植株的芦荟粉及浓缩的芦荟凝胶，对相继就诊的702例患者做斑贴试验。设计专门的问卷调查芦荟的使用、使用原因、使用部位、不良反应、患者职业、个人爱好及是否为遗传性过敏体质。患者均未对任一制剂发生任何反应。需对芦荟所含的两种成分加以鉴别：即芦荟叶皮含有的具有促进肠蠕动、潜在抗菌及抗癌特性的蒽醌类物质。     

Radiation dose reduction during hysterosalpingography: an application of scanning-beam digital radiography

Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.     

Clustering of Ca2+ channels and Ca(2+)-activated K+ channels at fluorescently labeled presynaptic active zones of hair cells.

Electrical resonance, which in some hair cells provides a mechanism for frequency tuning, is mediated by clusters of Ca2+ channels and Ca(2+)-activated K+ channels that have been proposed to occur at presynaptic active zones. To localize Ca2+ channels on the cellular surface, we loaded hair cells from the frog's sacculus with the Ca2+ indicator fluo-3 and imaged them by fluorescence confocal microscopy. When a cell was depolarized, we observed on its basolateral surface several foci of transiently enhanced fluorescence due to local Ca2+ influx. After protracted recording, each cell displayed on average 18 brightly and permanently fluorescent spots at the same positions. We mapped these spots in four hair cells and compared their locations with those of presynaptic active zones, as determined from transmission electron micrographs of serial sections through the same cells. The results demonstrated that enhanced fluo-3 fluorescence marks active zones. Measurement of currents through membrane patches at fluorescently labeled active zones demonstrated that both voltage-activated Ca2+ channels and Ca(2+)-activated K+ channels occur there. These results confirm that the ion channels involved in electrical tuning and synaptic transmission by hair cells cluster together at presynaptic active zones.     

Solitary bronchioloalveolar carcinoma: CT criteria

The computed tomographic (CT) scans of 30 patients with solitary bronchioloalveolar carcinoma were reviewed. Common features at CT included the peripheral or subpleural location of a pulmonary mass (25 cases), pseudocavitation (18 cases), heterogeneous attenuation (17 cases), irregular margins forming a star pattern (22 cases), and pleural tags (21 cases). Using these CT criteria, four independent observers attempted to identify cases of bronchioloalveolar carcinoma from a larger sample of lung cancers and benign lesions by categorizing a series of test cases into four probability categories. Although the bronchioloalveolar carcinomas were correctly ranked in the two highest probability categories 75% of the time (in 45 of 60 cases), there was considerable overlap with other lung lesions, particularly with adenocarcinoma and large cell undifferentiated carcinoma. However, even though the typical features of bronchioloalveolar carcinoma are not invariable or highly specific, they are characteristic enough to suggest the diagnosis.