Invalidation of antiglobulin tests by a high thermal amplitude cryoglobulin

A multiply transfused patient was referred for evaluation of a transfusion reaction. The direct and indirect antiglobulin tests (DAT, IAT) for alloantibody were negative. However, IgG-coated control cells failed to agglutinate in the negative reactions, casting doubt on their validity. At 4 degrees C, the patient's serum exhibited a large cryoprecipitate (2.9 mg/mL), made up predominantly of an IgG kappa paraprotein and having trace amounts of IgM and C3. Clear serum separated at 37 degrees C became cloudy within 10 minutes at room temperature (RT); within 4 hours, approximately 60 percent of the total precipitable cryoprotein had precipitated. Red cells (RBCs) incubated in fresh serum that had cooled to RT or RBCs obtained from RT or refrigerated samples contained cryoprecipitate that sedimented with the RBCs during washing with RT saline. On resuspension, enough IgG cryoglobulin redissolved to neutralize completely the commercial anti-IgG reagents. If the patient's samples were maintained at 37 degrees C, cryoprecipitate did not form, and RBCs washed four times at 37 degrees C gave valid DAT and IAT reactions. The removal of all cryoprecipitate from the patient's serum by centrifugation after overnight incubation at 4 degrees C also made possible valid antibody screening and compatibility tests.     

Transgenic mice expressing human sickle hemoglobin are partially resistant to rodent malaria

The polymorphic frequency of the gene for beta s-globin involved in the generation of sickle trait and sickle cell anemia in the human population is caused by the enhanced resistance of sickle trait individuals to Plasmodium falciparum malaria, as supported by epidemiologic and in vitro studies. However, the mechanism for the protective effect of sickle hemoglobin in vivo has not been fully defined. The generation of transgenic mice expressing high levels of human beta s- and alpha-chains has allowed us to study this phenomenon in vivo in an experimental model. We infected the transgenic beta s mice with two species of rodent malaria and found a diminished and delayed increase in parasitemia as compared with controls. This is in contrast to our previous studies involving the introduction of a beta A transgene, which does not alter the infection. The use of this model allowed us to address the question of the mechanism of protection against malaria in mice expressing sickle hemoglobin. We find that splenectomy of transgenic mice completely reverses the protection against Plasmodium chabaudi adami infection. The results reported have shown a relationship between the presence of the beta s gene product and partial resistance to malaria in an experimental model in vivo and shows that the spleen plays an important role in this protection.     

肥厚型心肌病患者肌球蛋白结合蛋白C基因筛查及其相应的临床特征

目的 研究国人肥厚型心肌病(HCM)患者的致病基因一肌球蛋白结合蛋白C基因(myosin binding protein C gene,MYBPC3)的突变位点,分析基因突变类型与临床表型的相互关系.方法对66例HCM患者的MYBPC3基因进行扫描,聚合酶链反应扩增其外显子及剪接部位的基因组DNA片段,直接测序分析.分析各突变患者相应的临床表型特点.结果经测序分析,发现Lys30lfs移码突变、Asp463stop无义突变、Gly523Arg错义突变和Tyr847His错义突变.MYBPC3导致的HCM为3例,占病例总数的4.5%.其临床表型各异,患者H30(Lys301fs)47岁发病,活动后胸闷、气短,超声显示室间隔肥厚达18.7 mm,左心室后壁14.7 mm.患者H48(Asp463stop)为25岁男性,24岁发病,室问隔肥厚达15.4 mm.患者H53(Gly523Arg和Tyr847His)发病年龄36岁,活动后胸闷、憋气,伴心前区疼痛,室间隔肥厚达27 min.结论 MYBPC3突变为HCM主要致病原因之一.MYBPC3突变基因携带者临床表型差异大.国人MYBPC3突变患者多在青壮年期发病,不同于国外报道的多发病较晚.     

Periprosthetic Fracture Torque for Short Versus Standard Cemented Hip Stems: An Experimental In Vitro Study

In an attempt to preserve proximal femoral bone stock and achieve a better fit in smaller femora, especially in the Asian population, several new shorter stem designs have become available. We investigated the torque to periprosthetic femoral fracture of the Exeter short stem compared with the conventional length Exeter stem in a Sawbone model. Forty-two stems; 21 shorter and 21 conventional stems both with three different offsets were cemented in a composite Sawbone model and torqued to fracture. Results showed that Sawbone femurs break at a statistically significantly lower torque to failure with a shorter compared to conventional-length Exeter stem of the same offset. Both standard and short-stem designs are safe to use as the torque to failure is 7–10 times that seen in activities of daily living.     

Computer administration of a school-based adolescent health survey

Objective : To examine the utility of notebook computers in the collection of data in large scale surveys.
Methodology : A notebook computer administered survey of health in adolescents was conducted in 1992 using a multi-instrument questionnaire. Students in school years 7,9 and 11 in private and government schools in Melbourne and rural Victoria participated.
Results : Parental consent was obtained with an 83% response rate. Each student answered questions directly onto the computer taking an average of 68 min to complete the highly branched confidential but not anonymous questionnaire. Students were presented with on average 33% of the 897 possible questions. Over 90% of students reported enjoying using the computer. Those who reported answering the questions honestly all the time ranged from 68 to 85%, increasing with grade level.
Conclusions : The use of computers in survey research provides many advantages in data collection including exposure only to relevant questions and the opportunity of asking sensitive questions.     

跨专业团队合作式自我管理教育对体检高血压患者的干预效果研究

目的 探讨跨专业团队合作式自我管理教育在体检高血压患者干预中的应用效果。方法 选取2019年4—6月在武汉某三级综合性教学医院的100名体检的高血压患者为研究对象,实施跨专业团队合作式自我管理教育。分别在干预前、干预3个月末、干预6个月末评估患者低密度脂蛋白胆固醇控制达标率、高血压治疗态度与信念评分、高血压治疗依从性评分、血压控制达标率。结果 干预前、干预3个月末、干预6个月末高血压患者低密度脂蛋白胆固醇及血压控制达标率比较差异具有统计学意义（P<0.001）。干预前、干预3个月末、干预6个月末高血压患者坚持治疗态度与信念、服药治疗态度与信念、治疗性生活方式态度与信念、持续治疗困扰与顾虑得分比较差异有统计学意义（P<0.001）。干预前、干预3个月末、干预6个月末高血压患者遵医服药行为、不良服药行为、日常生活管理行为、烟酒嗜好管理行为得分比较差异有统计学意义（P<0.001）。结论 跨专业团队合作式自我管理教育对体检高血压患者进行健康管理,可提高患者治疗的态度与信念及治疗依从性,从而提高患者血压及低密度脂蛋白胆固醇控制达标率。     

磁共振检查患者负性情绪的预防和疏导

MR设备磁体孔径狭长,扫描间相对封闭,加之扫描时间较长,梯度噪声较大,以及快速交变梯度场引起的生物效应,使患者产生了不同程度的心理压力和恐惧,即医学上称之幽闭恐惧症。在人们日益对健康关注的今天,如何消除患者这种负性情绪,以获得满意的检查效果,值得我们更进一步的探讨。1患者检查前的心理特点分析初检的患者,依其年龄、性格、文化修养及病情轻重多存在有担心、恐惧,尤其担心检查结果。由于长期以来人们对“核磁共振”的错误理解所产生的“核”畏惧,担心作此项检查会给自己身体带来辐射损害,另外担心检查的结果。大多数患者到医院来就诊大都存在身心不适,希望能查明自己不适的病因;但有部分患者担心花了高昂的检查费用,检查未发现异常,进而对医院产生不信任;另有一部分患者担心查出自己身患癌症,此类患者心理活动极其复杂。而对那些再次磁共振检查或多次检查的患者,更多的担心是自己病情的好转情况,或者是对设备噪声的恐惧。2检查前的磁共振知识宣讲、解释和交流沟通针对不同患者不同的心理特点,检查前通过对磁共振知识的宣讲,让患者从心理上消除对“核”辐射的恐惧;纠正患者对医院的偏见和误解,耐心解释患者提出的关于病情、费用、检查的不良作用等问题,与患者建立...     

Length-dependent gametic CAG repeat instability in the Huntington's disease knock-in mouse

The CAG repeats in the human Huntington's disease (HD) gene exhibit striking length-dependent intergenerational instability, typically small size increases or decreases of one to a few CAGs, but little variation in somatic tissues. In a subset of male transmissions, larger size increases occur to produce extreme HD alleles that display somatic instability and cause juvenile onset of the disorder. Initial efforts to reproduce these features in a mouse model transgenic for HD exon 1 with 48 CAG repeats revealed only mild intergenerational instability ( approximately 2% of meioses). A similar pattern was obtained when this repeat was inserted into exon 1 of the mouse Hdh gene. However, lengthening the repeats in Hdh to 90 and 109 units produced a graded increase in the mutation frequency to >70%, with instability being more evident in female transmissions. No large jumps in CAG length were detected in either male or female transmissions. Instead, size changes were modest increases and decreases, with expansions typically emanating from males and contractions from females. Limited CAG variation in the somatic tissues gave way to marked mosaicism in liver and striatum for the longest repeats in older mice. These results indicate that gametogenesis is the primary source of inherited instability in the Hdh knock-in mouse, as it is in man, but that the underlying repeat length-dependent mechanism, which may or may not be related in the two species, operates at higher CAG numbers. Moreover, the large CAG repeat increases seen in a subset of male HD transmissions are not reproduced in the mouse, suggesting that these arise by a different fundamental mechanism than the small size fluctuations that are frequent during gametogenesis in both species.