快速成型骨组织工程支架的结构及力学仿生性能特征

目的:利用显微CT的成像技术及材料力学测试,观察多孔双相磷酸钙陶瓷支架的三维结构和力学仿生性能特征。方法:实验于2004-06/2005-12在清华大学新型陶瓷与精细工艺国家重点实验室、香港中文大学威尔士亲王医院骨与关节肌肉研究室和解放军总医院骨科研究所完成。利用三维凝胶叠层成型技术和发泡法复合的方法,制备仿骨多孔双相磷酸钙陶瓷支架,经显微CT扫描得到分辨率为20μm的断层图像,并按骨形态计量方法计算三维计量参数,并与急性脑死亡年轻人股骨头(由解放军总医院骨组织库提供,已签署捐献同意书)标本负重区松质骨样本的三维参数进行统计比较。最后对双相磷酸钙陶瓷支架两个互相垂直方向和松质骨样本的长轴方向进行压缩强度试验,计算压缩强度和弹性模量,并进行统计分析。结果:①双相磷酸钙陶瓷支架的小梁平均宽度和间距低于松质骨小梁(P<0.05);支架的小梁数目和各项异性程度高于松质骨样本(P<0.05);说明支架小梁在排列上呈现更为明显的各向异性特征。②双相磷酸钙陶瓷支架的体积分数、表面积体积比及结构模型指数与松质骨样本相比差异无显著性(P>0.05),两组样本均呈明显的板层结构。③力学测试结果显示双相磷酸钙陶瓷支架材料长轴方向的强度和弹性模量高于垂直方向(P<0.05),说明支架材料具有明显的方向性。长轴方向的强度低于正常松质骨样本,但弹性模量仅比松质骨样本弹性模量高20%(P<0.05)。结论:支架材料在空隙率和表面积方面具有很好的仿生性,利于细胞的黏附和长入。同时具有明显的方向性,提高了其在排列方向上的强度。弹性模量接近股骨头松质骨,具有较好的应力顺应性。     

Surgery in patients with haemophilia and high responding inhibitors: Izmir experience

Summary. This report evaluates the haemostatic efficacy of recombinant factor VIIa (rFVIIa) and activated prothrombin complex concentrate (APCC) in patients with haemophilia and high responding inhibitors who underwent major and minor surgery. Data pertaining to surgeries from 2001 to 2009 at a single centre were retrospectively analysed. During this period, 53 surgical procedures were performed in 30 haemophiliacs with high responding inhibitors. Mean age was 16.2 ± 9.4 years. Eleven major surgeries in 4 patients, 41 radioisotope synovectomies (RS) and one circumcision classified as minor surgery in 28 patients were performed. Among the major surgery procedures, four were treated with rFVIIa, five with APCC and two with sequential use of APCC and rFVIIa. We used rFVIIa at the dosage of 80–120 μg kg^?1 every 2 h and APCC 100 IU kg^?1 every 12 h for the major surgery. When performing RS, we used rFVIIa in 18 patients with 26 target joints and APCC in 9 patients with 15 target joints. Three consecutive doses of rFVIIa (90 μg kg^?1) were used at 2‐h intervals followed by additional three doses at 6‐h intervals. The initial dose of APCC was 75 IU kg^?1 followed by a second and third dose of 50 IU kg^?1 at 12‐h intervals. APCC and rFVIIa demonstrated excellent efficacy in our major and minor surgical interventions [100% (22/22) and 94% (31/33), respectively]. We had only two bleeding complications with rFVIIa. There were no thromboembolic complications. APCC and rFVIIa provide an effective and safe first line haemostatic therapy for inhibitor‐positive haemophiliacs, allowing both major and minor surgery to be successfully performed.     

Patient resources in the therapeutic education of haemophiliacs in France: their skills and roles as defined by consensus of a working group

Summary. The activities of ‘expert patients’ or ‘patient tutors’, who help educate their peers, are gaining recognition in the health care system. This study investigates the role played by such patients in therapeutic education programmes organized by caregivers to validate the role of patients in implementing the therapeutic education of haemophilic patients and to define the skills required for such activities. This study employs the consensus methodology recommended by France’s National Authority for Health. The working group includes seven caregivers from Hemophiliac Treatment Centers (HTCs) and three patients from the French Association of Hemophiliacs (FAH). The role of patients in haemophilia education is recognized. Patients participating in the education of their peers are referred to as ‘patient resources’. A patient resource should be an adult, a volunteer and live in the same region as his peers. Candidates are chosen by the FAH and the HTCs to serve based on their motivation to facilitate the education of other patients as well as on their psychological and pedagogical aptitudes. A patient resource participates in the conception and administration of therapeutic education programmes. He also mediates between the caregivers and the patients. He ensures that the patients understand the material and are able to apply their knowledge in daily life. His activities are governed by professional ethics. Seven categories of skills were defined, permitting the group to determine precisely which skills are required to function as a patient resource. Supervision of the patients is planned to reinforce reflexive practices in the patients. Evolution of the health care system has led patients to become involved in therapeutic education. This phenomenon calls for a framework to be developed and an evaluation of its eventual effects.     

Post-COVID syndrome: pulmonary complications

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected millions of people worlwide and caused a pandemic that is still ongoing. The virus can cause a disease named as COVID-19, which is composed of multi systemic manifestations with a pulmonary system predominance. As the time passes, we are dealing more and more with a wide variety of effects and complications of the disease in survivors as far as with concerns about the clinical outcome and the timeline of symptoms in different patients. Since the lungs are the most involved organs and the post-COVID prolonged and persistent effects are mainly related to the pulmonary system, it is crucial to define and predict the outcome and to determine the individuals that can progress to fibrosis and loss of function of lungs. This review summarizes the current literature regarding the pulmonary complications in post-COVID syndrome and the management of these conditions.     

Measurement of family impact of skin disease: further validation of the Family Dermatology Life Quality Index (FDLQI)

Aim To adapt the Impact on Family scale (IOF), originally developed for families of children with chronic illnesses, for use in families of adult patients and to examine the convergent validity of the Family Dermatology Life Quality Index (FDLQI) by comparing it with the adapted version of the IOF scale. Methods Adult family members of patients with different skin diseases attending the out‐patients clinic of a secondary referral centre completed the FDLQI and the adapted version of the IOF scale, whereas patients completed the Dermatology Life Quality Index (DLQI). Results A total of 50 patients and 50 family members/partners participated in the study. The mean scores for the three instruments were as follows: FDLQI = 6.0 (SD = 6.4, median = 4); IOF scale = 27.9 (SD = 8.2, median = 29); DLQI = 5.4 (SD = 5.6, median = 3). There was no difference between male and female participants in the mean scores of any of the three instruments. The FDLQI demonstrated high internal consistency (Cronbach's α = 0.91). Factor analysis revealed the presence of one factor structure underlying the items of the FDLQI, which explained 55.8% of the total variance. The IOF scale also showed a high internal consistency (Cronbach's α = 0.89). The results of factor analysis revealed one dominant factor and three weaker factors, which together explained 72% of the total variance. The convergent validity of the FDLQI was demonstrated by a highly significant positive correlation between the mean FDLQI and the IOF scale scores (r_s = 0.61, P < 0.0001). All the items of the FDLQI also had significant correlations with the mean total IOF scale scores (P < 0.05). Conclusions The results of this study have demonstrated that with minor modifications IOF scale, which was originally developed for families of children suffering from chronic illnesses, can also be used in families of adult dermatology patients. The study has also provided further evidence of the validity of the newly developed FDLQI.     

THE ‘VASOVAGAL EFFECT’ OF NITRATES: AN UNDER-RECOGNISED COMPLICATION OF NITRATE USE

SUMMARY Nitrates are useful drugs in cardiovascular medicine. They have a presumed vasovagal effect, which is a rare but often under-recognised complication that is partly caused by central inhibition of the sympathetic nervous system. However, no consistent variable associated with the presumed vasovagal effects following nitrate administration can be identified, and there are only limited reports of the phenomenon in the literature. In fact, the true prevalence of such a complication is unknown, because no data from observational studies exist, although it would seem likely to be a rare event. A greater awareness and recognition of this unusual effect of nitrate use is necessary in view of the increasing use of nitrates. Fortunately, recovery is generally the rule with supportive management.