Premature ovarian failure

Premature ovarian failure (POF) causing hypergonadotrophic hypogonadism occurs in 1% of women. In majority of cases the underlying cause is not identified. The known causes include: (a) Genetic aberrations, which could involve the X chromosome or autosomes. A large number of genes have been screened as candidates for causing POF; however, few clear causal mutations have been identified. (b) Autoimmune ovarian damage, as suggested by the observed association of POF with other autoimmune disorders. Anti-ovarian antibodies are reported in POF by several studies, but their specificity and pathogenic role are questionable. (c) Iatrogenic following surgical, radiotherapeutic or chemotherapeutic interventions as in malignancies. (d) Environmental factors like viral infections and toxins for whom no clear mechanism is known. The diagnosis is based on finding of amenorrhoea before age 40 associated with FSH levels in the menopausal range. Screening for associated autoimmune disorders and karyotyping, particularly in early onset disease, constitute part of the diagnostic work-up. There is no role of ovarian biopsy or ultrasound in making the diagnosis. Management essentially involves hormone replacement and infertility treatment, the only proven means for the latter being assisted conception with donated oocytes. Embryo cryopreservation, ovarian tissue cryopreservation and oocyte cryopreservation hold promise in cases where ovarian failure is foreseeable as in women undergoing cancer treatments.     

PET脑显像及其他显像技术在放射性脑损伤诊断的对比性研究

目的 探讨^18F－脱氧葡萄糖（FDG）正电子发射型计算机断层显影（PET）脑显像和其他医学影像方法对早期诊断放射性脑损伤的价值，以达到预防、减少脑放射损伤的目的。方法 静脉注射^18F-FDG后行脑显像，获得横断面、冠状面、矢状面断层显像。所有病人均进行CT检查。结果 20例正常人脑PET显像图像可见大脑皮质各叶、基底神经节、丘脑及小脑放射性分布均匀对称。12例完成头颈部恶性肿瘤放疗后有临床症状者均检出不同程度局灶性脑组织葡萄糖代谢下降，显像阳性率100％；其中10例鼻咽癌放疗后PET结果提示放射脑损伤病灶共23处，最常见于颞叶病灶13处、脑干4处、小脑4处以及顶叶2处。2例脑胶质细胞瘤放疗病人，PET结果提示病灶：顶叶2处、颞叶1处、枕叶1处。12例放疗后病人CT检查仅10例提示放射性脑损伤。结论 PET脑显像能准确、早期诊断脑放射损伤，是头颈部恶性肿瘤肿瘤放疗后的非常重要的监测手段。     

Case of postradiation osteosarcoma with a short latency period of 3 years

Osteosarcoma is one of the neoplasms that may occur following exposure to radiation. A case of osteosarcoma arising in the craniofacial bone with a short latency period of 3 years after radiotherapy for maxillary squamous cell carcinoma is described. A 64-year-old-man underwent right partial maxillectomy and chemoradiotherapy due to squamous cell carcinoma of his right maxillary sinus. Histologically, the tumor was composed of moderately differentiated squamous cell carcinoma with a component of spindle cell carcinoma. Three years later, osteosarcoma developed in the craniofacial bone within the irradiation field of the first tumor. Detailed histological examination demonstrated that there was no component of osteosarcoma in the first tumor or squamous cell carcinoma in the second tumor. Radiation-induced osteosarcoma usually occurs after a long latency period of more than 10 years after the radiotherapy. In this case, osteosarcoma was possibly a radiation-induced osteosarcoma with a short latency period of 3 years.     

Chromosome neighborhood composition determines translocation outcomes after exposure to high-dose radiation in primary cells

Radiation exposure is an occupational hazard for military personnel, some health care professionals, airport security screeners, and medical patients, with some individuals at risk for acute, high-dose exposures. Therefore, the biological effects of radiation, especially the potential for chromosome damage, are major occupational and health concerns. However, the biophysical mechanisms of chromosome instability subsequent to radiation-induced DNA damage are poorly understood. It is clear that interphase chromosomes occupy discrete structural and functional subnuclear domains, termed chromosome territories (CT), which may be organized into ‘neighborhoods’ comprising groups of specific CTs. We directly evaluated the relationship between chromosome positioning, neighborhood composition, and translocation partner choice in primary lymphocytes, using a cell-based system in which we could induce multiple, concentrated DNA breaks via high-dose irradiation. We critically evaluated mis-rejoining profiles and tested whether breaks occurring nearby were more likely to fuse than breaks occurring at a distance. We show that CT neighborhoods comprise heterologous chromosomes, within which inter-CT distances directly relate to translocation partner choice. These findings demonstrate that interphase chromosome arrangement is a principal factor in genomic instability outcomes in primary lymphocytes, providing a structural context for understanding the biological effects of radiation exposure, and the molecular etiology of tumor-specific translocation patterns.     

Repeatability of measuring knee flexion angles with wearable inertial sensors

Background

As assessment with inertial-measurement-units (IMUs) increases in research and in clinics, it is important to be aware of the repeatability of these sensors. The objectives of this experiment were to evaluate the measurement repeatability of IMU joint angles using a repeatable robot controller and an anthropomorphic leg phantom and to determine effects of joint speed and sensor positioning on the angles collected by these sensors. Comparisons to an electro-goniometer and three-dimensional (3D) motion capture cameras were also completed.

多气阀数字血压计的研制

本文研制的袖套式数字血压计，基于示波法原理，通过采用多通道、多气阀以及软件上的改进，改善了目前一般数字血压计的不足，与一般袖套式数字血压计相比，具有重复性好、测量范围大（成人和儿童都可测量）等优点。     

Direct blood-pressure measurements: risks,technological evolution and some current problems

The direct measurement of blood pressure has found widespread use in intensive care units, operating rooms, and in emergency departments. Infection, air embolism and thrombosis are some of the risks to patients associated with both the cannulation procedure and with the apparatus used in the blood-pressure measuring process. Although there is constant revision in an attempt to reduce these risks, they cannot be completely eliminated. The need for direct blood-pressure measurements and the physiological effects of air embolism and thrombosis are reviewed. Infection and problems related to the techniques used to insert the catheters are not discussed.     

利用脉搏波特征参数连续测量血压的方法研究

通过研究血压与脉搏波特征参数的关系，提出了一个选择多个与血压相关的脉搏波特征参数,通过回归分析建立适合不同人的特征方程，进行血压的连续测量的新方法，为了验证测量结果的准确性；研制了张力计。实验结果表明：该方法具有较高的测量精度，可以应用于临床危重病人的血压监护和一般医学研究中，经过进一步地改进和完善后可应用于载人航天和日常动态环境。     

耳穴静态电测量中的瞬变响应

耳穴电参数时变关系实验表明，在测量起始ｔ＜２τ时，因瞬变作用，电位Ｅ（ｔ）和压降Ｕ（ｔ）为瞬态响应，响应函数呈指数关系，特征参数为弛豫时间τ，τ≈ＲＣ；ｔ＞２τ时，为时变间期。电路分析给出数学描述，并与耳穴和模拟实验结果较相符。提示，时变特征应以ｔ＞２τ后提取，静态电测量时，采样应避开瞬变期，可提高准确性。该工作对正确鉴别时变性和特征提取，全面认识耳穴电特性具有重要意义。