A point mutation (W70A) in the rod PDE-gamma gene desensitizing and delaying murine rod photoreceptors

PURPOSE: To examine the corneal electroretinogram (ERG) of transgenic mice (W70A mice) carrying a point mutation (W70A) in the gene encoding for the gamma-subunit of rod cGMP phosphodiesterase (PDEgamma). METHODS: The ERG of W70A mice was compared with that of normal mice. Cone responses were separated from rod responses by light adaptation, whereas rod sensitivity was assessed by threshold stimulation with dim light. Spectral sensitivity curves of the ERG were obtained using a constant response criterion. RESULTS: The ERG of the W70A mouse has a desensitized, delayed rod b-wave at threshold, and a prolonged rod b-wave at higher flash intensities. The a-wave is absent even at maximal stimulation. The cone ERG of the W70A mouse is indistinguishable from that of normal mice. The spectral sensitivity of the W70A mouse is maximal in the UV spectrum, in contrast to the normal mouse, which is most sensitive in the green region of the spectrum. This supports the interpretation of the results as normal cone and abnormal rod function in the W70A mouse. CONCLUSIONS: The W70A mouse represents new model of stationary nyctalopia that can be recognized by its unusual ERG features.     

High-affinity autoreactive plasma cells disseminate through multiple organs in patients with immune thrombocytopenic purpura

The major therapeutic goal for immune thrombocytopenic purpura (ITP) is to restore normal platelet counts using drugs to promote platelet production or by interfering with mechanisms responsible for platelet destruction. Eighty percent of patients with ITP possess anti–integrin αIIbβ3 IgG autoantibodies that cause platelet opsonization and phagocytosis. The spleen is considered the primary site of autoantibody production by autoreactive B cells and platelet destruction. The immediate failure in approximately 50% of patients to recover a normal platelet count after anti-CD20 rituximab-mediated B cell depletion and splenectomy suggests that autoreactive, rituximab-resistant, IgG-secreting B cells (IgG-SCs) reside in other anatomical compartments. We analyzed more than 3,300 single IgG-SCs from spleen, bone marrow, and/or blood of 27 patients with ITP, revealing high interindividual variability in affinity for αIIbβ3, with variations over 3 logs. IgG-SC dissemination and range of affinities were, however, similar for each patient. Longitudinal analysis of autoreactive IgG-SCs upon treatment with the anti-CD38 mAb daratumumab demonstrated variable outcomes, from complete remission to failure with persistence of high-affinity anti–αIIbβ3 IgG-SCs in the bone marrow. This study demonstrates the existence and dissemination of high-affinity autoreactive plasma cells in multiple anatomical compartments of patients with ITP that may cause the failure of current therapies.     

液基细胞学结合阴道镜检查在北京市社区妇女宫颈病变筛查中的意义

目的探讨宫颈液基细胞学及阴道镜检查在北京市社区妇女宫颈病变筛查中的临床意义。方法2006年6月至2007年6月对北京市展览路社区的795位20～54岁有性生活的妇女进行筛查。筛查对象接受妇科检查时,留取宫颈超柏氏薄层液基细胞学检测标本,并对宫颈细胞学异常者行阴道镜检查及活组织检查。结果宫颈细胞学阳性[≥ASC-US（不能明确意义的不典型鳞状细胞）]45例,占5．7％（45／795）。其中ASC-US33例,占73．3％（33／45）;低度鳞状上皮内病变8例;高度鳞状上皮内病变3例;不典型腺细胞1例。细胞学阴性750例,占94．3％（750／795）。宫颈细胞学阳性的45例中,5例拒绝行阴道镜检查,占11．1％（5／45）。在行阴道镜活组织病理检查的40例中,慢性宫颈炎11例（27．5％）;宫颈湿疣14例（35．0％）;宫颈上皮内瘤样病变（CIN）1为7例（17．5％）;CIN2为3例（7．5％）;CIN3为4例（10．0％）;早期浸润癌1例（2．5％）。细胞学阴性的750例中,宫颈湿疣2例（0．3％）;CIN1为5例（0．7％）;宫颈低级别腺上皮内病变1例（0．1％）。宫颈液基细胞学筛查CIN1及以上宫颈病变和宫颈癌的敏感度71．4％,特异度94．2％,阳性预测值37．5％,阴性预测值99．2％;筛查CIN2及以上宫颈病变和宫颈癌的敏感度100．0％,特异度96．0％,阳性预测值20．5％,阴性预测值100．0％。结论应重视并及时进行北京市社区人群宫颈病变的早期筛查,薄层液基细胞学结合阴道镜活组织检查及病理学检查,对提高早期宫颈癌筛查的准确性效果明显。