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。     

Effect of memantine on cue-induced alcohol craving in recovering alcohol-dependent patients

OBJECTIVE: Ethanol blocks N-methyl-d-aspartic acid (NMDA) glutamate receptors. Increased NMDA receptor function may contribute to motivational disturbances that contribute to alcoholism. The authors assessed whether the NMDA receptor antagonist memantine reduces cue-induced alcohol craving and produces ethanol-like subjective effects. METHOD: Thirty-eight alcohol-dependent inpatients participated in three daylong testing sessions in a randomized order under double-blind conditions. On each test day, subjects received 20 mg of memantine, 40 mg of memantine, or placebo, and subjective responses to treatment were assessed. The level of alcohol craving was assessed before and after exposure to an alcohol cue. RESULTS: Memantine did not stimulate alcohol craving before exposure to an alcohol cue, and it attenuated alcohol cue-induced craving in a dose-related fashion. It produced dose-related ethanol-like effects without adverse cognitive or behavioral effects. CONCLUSIONS: These data support further exploration of whether well-tolerated NMDA receptor antagonists might have a role in the treatment of alcoholism.     

Co-morbidity of infectious and addictive diseases in St. Petersburg and the Leningrad Region, Russia

The Russian health care system is organized around specific diseases, with relatively little focus on integration across specialties to address co-morbidities. This organizational structure presents new challenges in the context of the recent epidemics of injection drug use (IDU) and HIV. This paper uses existing and new data to examine the prevalence of reported new cases of drug dependence (heroin) and HIV over time as well as associations between drug dependence and alcoholism, hepatitis B and C, and tuberculosis in the City of St. Petersburg and the Leningrad region. We found a sharp rise in reported cases of IDU beginning in 1991 and continuing until 2002/2003, followed by a sharp rise in newly reported cases of HIV. These rises were followed by a drop in new cases of HIV and drug addiction in 2002/2003 and a drop in the proportion of HIV-positive individuals with IDU as a risk factor. Infection with hepatitis B and C were common, especially among injection drug users (38 and 85%, respectively), but also in alcoholics (7 and 14%). Tuberculosis was more common in alcoholics (53%) than in persons with alcoholism and drug dependence (10%), or with drug dependence alone (4%). Though these data have many limitations, they clearly demonstrate that drug dependence and/or alcoholism, HIV, hepatitis, and tuberculosis frequently co-occur in St. Petersburg and the Leningrad Region. Prevention and treatment services across medical specialties should be integrated to address the wide range of issues that are associated with these co-morbidities.     

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.     

Antitumor activity of the new gestagen 17alpha-acetoxy-3beta-butanoyloxy-6-methyl-pregna-4,6-dien-20-one

Antitumor activity of a new highly active promising gestagen 17alpha-acetoxy-3beta-butanoyloxy-6-methyl-pregna-4,6-dien-20-one (butagest) was studied in mice with model cervical carcinoma (RShM-5). The reference drug was medroxyprogesteron acetate (MPA, Depo Provera) used in clinics. The new preparation introduced perorally in a dose of 1 mg per mice inhibited the model tumor growth by 73%, which was 18% (p < 0.01) more effective than the action of the reference drug MPA. The effect of the new gestagen was also studied in vitro with respect to human breast carcinoma of the MCF-7 line and human cervical carcinoma HeLa. The viability of the tumor cells was studied during a 6-day incubation with the drug at a concentration of 10(-7)-10(-5) M (MTT test). The reference compounds were progesterone and MPA. These drugs suppressed the growth of both MCF-7 and, in higher concentrations, of HeLa. Butagest inhibited the growth of HeLa in all concentrations. Thus, the new gestagen 17alpha-acetoxy-3beta-butanoyloxy-6-methyl-pregna-4,6-dien-20-one is capable of suppressing the viability of human breast carcinoma and human cervical carcinoma, being comparable or even more effective than the reference drugs.     

Detection, identification, and comparison of Capnocytophaga, Bacteroides ochraceus, and DF-1.

Working independently, three laboratories had recognized considerable similarity among certain strains of dysgonic, fermentative, capnophilic, surface translocating, gram-negative bacilli referred to as Capnocytophaga, Bacteroides ochraceus, and Center for Disease Control biogroup DF-1. To determine the relationship among these groups, 21 strains were exchanged and independently characterized by the three laboratories. Additionally, a fourth laboratory examined the deoxyribonucleic acid homologies of the same strains. Using methods common to dental microbiology, eight of the strains had been isolated from the gingival sulcus and periodontal lesions and identified as Capnocytophaga. Three strains isolated from blood and transtracheal aspirate had been characterized by conventional anaerobic methods and recorded as B. ochraceus. Ten strains isolated from sputum, blood, throat, spinal fluid, and tracheal aspirate had been identified as DF-1 with the methods of E. O. King and a buffered single-substrate technique. All strains were similar in respect to colonial and microscopic morphology, surface translocation, biochemical features, gas-liquid chromatograms of metabolic end products, and deoxyribonucleic acid composition. We conclude that these biogroups should be termed Capnocytophaga species.     

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.