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451.
Objectives:
The purpose of this study was to determine the potential of high-resolution ultrasonography for the detection of temporomandibular joint (TMJ) changes in children with juvenile idiopathic arthritis (JIA).Methods:
We investigated prospectively 20 children (17 female and 3 male; mean age 11.06 years, standard deviation 3.43 years) with TMJ disorders caused by JIA, over a period of 16 months. Using a 12 MHz array transducer, four images in each TMJ (160 images) were acquired. Each image was analysed with regard to five different aspects (condylar erosion, thickness of the condylar disc, synovial thickness, joint effusion and enlargement of the intra-articular space).Results:
Diagnosis of JIA was ensured for every child and involvement of the TMJ was proven by MRI. Overall 287 changes (35.9%) were detected by using high-resolution ultrasonography. On 124 images (77.5%) condylar erosions were diagnosed; on 55 images (34.4%) synovial thickness was abnormal; on 48 images (30%) we could see higher thickness of the condylar disc; on 40 images (25%) irregularities of the bony surface were detected; and on 20 images (12.5%) we found joint effusion.Conclusion:
High-resolution ultrasonography could be a sufficient diagnostic method, especially for the detection of condylar involvement in children with JIA, even if not all parts of the TMJ are visible for ultrasonography. High-resolution ultrasonography is a valuable tool in particular situations: (i) when MRI examination is not available; (ii) when children fear MRI examination; (iii) in more advanced stages of JIA; and (iv) for monitoring the progression of TMJ involvement and response of therapy. 相似文献452.
The impact of heterosexual transmission of the human immunodeficiency virus (HIV) on the United States blood supply was assessed, and deferral criteria that may exclude potential donors who are at high risk for heterosexually acquired HIV infection were evaluated. Interviews were conducted with 508 HIV-seropositive blood donors from May 1, 1988, to August 31, 1989 (Phase 1), and with 472 donors from January 1, 1990, to May 31, 1991 (Phase 2), at 20 blood centers. From Phase 1 to Phase 2, the overall HIV prevalence decreased from 0.021 to 0.018 percent (p < 0.001). HIV risk factors among HIV-1-seropositive donors were similar during both study phases. Eleven percent of the men and 56 percent of the women reported as their only risk that they had a heterosexual partner who was at increased risk for HIV or was known to have HIV. These percentages were similar during both study periods. During Phase 2, 13 percent of the men and 17 percent of the women with heterosexual transmission risk had a positive serologic test for syphilis, hepatitis B core antibody, or hepatitis C antibody. Among HIV- 1-seropositive donors reporting heterosexual risk, the median numbers of previous-year and lifetime sex partners for men were 2 and 30, respectively; for women, those numbers were 1 and 7, respectively. Thirty-one percent of the men and 6 percent of the women reporting heterosexual transmission risk also reported having had syphilis or gonorrhea within 3 years of donation. It is concluded that the impact of heterosexual transmission of HIV infection on transfusion safety is not worsening at this time.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
453.
载溶菌酶聚乳酸-聚羟基乙酸共聚物微球的形成机制 总被引:5,自引:2,他引:5
目的:分析载溶菌酶聚乳酸-聚羟基乙酸共聚物微球的形成机制.
方法:实验于2005-03/07在暨南大学生物材料研究室完成.采用双乳液法(W/O/W法)制备聚乳酸-聚羟基乙酸共聚物微球.通过改变微球的制备条件[初乳时间(15,30,45,60,120 s)、初乳速度(6 000,10 000,14 000,18 000,22 000 r/min)、聚乙烯醇质量浓度(0,5,25,50,100 g/L)、复乳时间(0.5,2.5,5,8,11.5 h)、复乳速度(200,400,600,800,1 000 r/min)、初始药物质量浓度(0,20,40,60,80,100 g/L)、内/外水相添加剂(吐温-80、葡聚糖、蔗糖、氯化钠)、油相潜溶剂(丙酮、甲醇、乙醇、二甲基亚砜)],制备不同表面结构和内部结构的聚乳酸-聚羟基乙酸共聚物微球,扫描电镜下观察微球内/外部结构.
结果:制备出不同表面结构和内部结构的聚乳酸-聚羟基乙酸共聚物微球.微球表面主要呈3种状态:光滑致密、光滑多孔或粗糙多孔.微球的内部呈多孔洞或核壳结构.①初乳速度较低时(<10 000 r/min),微球表面以光滑为主,内部多孔,中间有一大的核心;初乳速度较高时(> 18 000 r/min),微球表面较为粗糙,内部孔洞致密,呈蜂巢状.②不同初乳时间制备的微球仍以表面平滑为主,有的微球表面有孔洞,大小在几个微米左右,微球内部仍然是蜂巢状结构.③聚乙烯醇质量浓度影响复乳的稳定性,从而对微球的形成过程影响很大.④复乳时间对微球形成过程的影响较为明显,反应时间过短(<0.5 h),微球未充分固化,增加反应时间,球形度相对提高.⑤复乳速度直接影响到复乳体系的稳定.速度较低时(200 r/min),形成的微粒体积较大,易形成不规整的大块聚集体.随着搅拌速度的增加,微粒球形度也相应提高.但是当速度过大时(1 000 r/min),微粒容易破裂形成碎散的不规则聚集体.⑥初始药物质量浓度对微球形成过程的影响很大,药物质量浓度高时(100 g/L),微球表面粗糙,碎片较多;药物质量浓度为60 g/L时,微球表面光滑,球形度很好.⑦不同的内水相添加剂(吐温-80、葡聚糖、蔗糖、氯化钠)制备的微球球形度均较好,微球表面平滑,但是存在部分微球相互粘连的情况.外水相添加蔗糖和氯化钠,微球的球形度较好,微球之间无粘连.但外水相添加吐温-80,形成的产物体积较大且形成许多不规则的聚集体.外水相添加葡聚糖形成的微球表面粗糙且含较多碎屑.⑧选用不同的油相潜溶剂(丙酮、甲醇、乙醇、二甲基亚砜)均存在部分的微球融合现象.
结论:从多角度系统阐述了载溶菌酶聚乳酸-聚羟基乙酸共聚物微球的形成机制.不同的制备条件对微球的结构影响各异,微球的尺寸分布及形态性能是初乳与复乳过程中各种影响因素综合作用的结果. 相似文献
454.
小百部的甾体皂甙成分 总被引:2,自引:0,他引:2
从云南产小百部(Asparagus filicinus Buch.-Ham)的根中分离到四个甾体皂甙,经光谱分析和化学降解,确定了结构,其中三个为新化合物,分别命名为小百部甙A(Ⅰ),小百部甙B(Ⅱ)和小百部甙C(Ⅲ)。另一个为已知皂甙Asp-Ⅳ的22-甲氧基化物(Ⅳ)。此外还分离到β-蜕皮甾酮(β-ecdysone,Ⅴ)。 相似文献
455.