Cross-calibration of dual-energy X-ray densitometers for a large, multi-center genetic study of osteoporosis

Osteoporosis is a common disease with a strong genetic component characterized by reduced bone mass and an increased risk of fragility fractures. Bone mineral density (BMD) is the most important determinant of osteoporotic fracture risk, but the genes responsible for BMD regulation and fracture are incompletely defined. To enable multi-center studies to examine the genetic influences on BMD there is a requirement to standardize measurements across different manufacturers of bone densitometers, different versions of machines and different normative ranges. This paper describes a method developed to allow near-identical subjects with low age-adjusted BMD (based on Z-scores) to be recruited in 17 centers using 27 different densitometers. Cross-calibration was based on measurements using a European spine phantom circulated to all centers and measured ten times on each individual machine. From theses values an individual exponential curve, based on nominal versus observed BMD, was derived for each machine. As expected, there were large and significant variations in nominal BMD values, not only between scanners from different manufacturers but also between different versions of scanners from the same manufacturer. Hologic scanners tended to underestimate the nominal BMD, while Lunar scanners overestimated the value. Norland scanners gave mixed values over estimating BMD at the lower nominal value (0.5 g/cm²) while underestimating the value at the higher value (1.5 g/cm²). The validity of the exponential equations was tested using hip and spine measurements on 991 non-proband women from a familial osteoporosis study (FAMOS). After cross-calibration there was a considerable reduction in variation between machines. This observation, coupled with the absence of a similar reduction in variation attributable to a linear regression on age, demonstrated the validity of the cross-calibration approach. Use of the cross-calibration curves along with a standard normative range (in the case of this study, the Hologic normative range) allowed age-specific Z-scores to be used as an inclusion criterion in this genetic study, a method that will be useful for other trials where age-specific BMD inclusion criteria are required.     

Kindergarten children's representation and understanding of written number symbols

Two samples of kindergarten children's representation and understanding of written number symbols were examined in two time points in one academic year. About 85% of Chinese five year olds (mean = 5 years 10 months) were able to use conventional number symbols to represent the quantity of 30 or larger. At the end of the kindergarten year, 94% of Chinese six year olds (mean = 6 years 4 months) were able to use conventional number symbols to represent the quantity of 100 or larger. Some Chinese six year olds had problems in representing written addition and subtraction tasks. Children's ability to represent written number symbols, ability to represent written addition and subtraction formula and their performance on written addition and subtraction were closely related. The performance of children in a university-affiliated childcare center was better than that of the center serving working-class families in Time 1, but the performance reversed at the end of the kindergarten year.     

V型斜视伴原发性下斜肌功能过强的治疗

目的 探讨Ⅴ型斜视伴原发性下斜肌功能过强的治疗效果。方法根据手术方式将49例Ⅴ型斜视伴下斜肌功能过强惠者分为四组，分别采用水平肌加强减弱术不联合下斜肌切断减弱术（Ⅰ组）、联合单侧下斜肌切断减弱术（Ⅱ组）、联合双侧下斜肌对等切断减弱术（Ⅲ组）及联合双侧下斜肌不对等切断并部分切除减弱术（Ⅳ组）治疗Ⅴ型斜视。结果Ⅴ型斜视伴原发性下斜肌功能过强采用四种方式治疗后，眼位正位，下斜肌功能亢进改善＋～＋＋，双侧下斜肌功能对等，术前术后原在位度数和上下注视25。斜视角之差的差异有非常显著性（P〈0．001）。结论根据单侧或双侧下斜肌功能过强的具体情况来选择不同的手术方式治疗Ⅴ型斜视伴原发性下斜肌功能过强，眼位矫正满意，同时手术方式简单、安全有效。     

Golgi study on brain of macular mutant mouse as a model of Menkes kinky hair disease

Summary This study was undertaken to elucidate, using the Golgi method, the neuropathological change in the brain of the macular mutant mouse, whose hemizygote (Ml/y) is considered to be a model of Menkes kinky hair disease (MKHD). The hemizygote mice gradually lost weight after 10 days of age and died with emaciation and seizure around day 15. The normal littermate (+/y) was well developed. In the cerebrum, the arborization of pyramidal neurons in the layer V of the Ml/y was the same as that in the +/y on day 10. However, development of arborization in the Ml/y was delayed in comparison with that in the +/y on days 12 and 14. Purkinje cells with several somal sprouts were observed in the cerebellum in both the Ml/y and +/y on day 7. The somal sprouts in the +/y had regressed gradually by day 12, while they were still in the anterior and middle lobes of the Ml/y on day 14. Additionally, the trunks of Ml/y stem dendrites became thicker and a cactus formation was recognized on the branching portion of the dendrites on day 14. Arborization of these abnormal Purkinje cells was distinctly poor compared with that in the +/y. These results suggest that the growth of the neurons is delayed in the Ml/y and simultaneously their cytoskeletal developments are disturbed, especially in the Purkinje cells. There is a close similarity in many respects to the neuropathological change in MKHD.     

The role of Self-Defined Race/Ethnicity in Population Structure Control

Population-based association studies are powerful tools for the genetic mapping of complex diseases. However, this method is sensitive to potential confounding by population structure. While statistical methods that use genetic markers to detect and control for population structure have been the focus of current literature, the utility of self-defined race/ethnicity in controlling for population structure has been controversial. In this study of 1334 individuals, who self-identified as either African American, European American or Hispanic, we demonstrated that when the true underlying genetic structure and the self-defined racial/ethnic groups were roughly in agreement with each other, the self-defined race/ethnicity information was useful in the control of population structure.     

Female alcoholics. V: The relationship between family history of alcoholism and outcome 3-10 years after treatment

In a long-term follow-up study of 44 female alcoholics, a family history of alcoholism was related to younger age of onset of problem drinking, but did not necessarily imply a poorer outcome within this highly selected group of individuals. Alcoholism in father and his family was not related to either antisocial or borderline personality disorder nor outcome. However, alcoholism in mother and her family correlated with both borderline personality disorder and a significantly poorer outcome. The findings are discussed within different frames of reference, considering genetic mechanisms, psychodynamic factors and family systems theory.     

Bone growth patterns in Chinese children and adolescents: a 6-year follow-up study provides evidence for sexual dimorphism and tracking

Summary We prospectively examined bone growth patterns in 894 children aged 6–17 years at the baseline visit, with a 6-year follow-up. Results show bone “tracking” over a six-year interval and sexual dimorphism of bone attained levels and timing of peak bone growth. Our findings underscore childhood and adolescence as critical periods for building bone and developing gender differences. Introduction Bone growth patterns were prospectively examined in 894 Chinese children (496 males), aged 6–17 yrs, from a population-based twin cohort. Whole-body bone area (BA), bone mineral content (BMC), and bone mineral density (BMD) were measured by DEXA at baseline and a 6-yr follow-up. Methods Graphic smoothing plots and generalized estimating equations were used to model bone attained levels, growth, and “tracking”. Results Attained levels of BMC and BA increased curvilinearly with age. Male attained levels were higher than females after age ∼15 yr, but BMD was lower between 13–17 yrs (Tanner stage I to IV). In both genders, peak BMC and BMD growth lagged ∼2 yrs behind peak BA growth, which lagged 2 yrs behind peak height growth. Peak bone growth occurred 1–3 yrs later in males. Over the 6-yr follow-up, all bone measurements “tracked”, but “shifting” across ranks also occurred, and baseline tertile ranking influenced bone growth. Females with early menarche had higher attained levels than females with late menarche at age 12–13 yrs. Conclusion Our findings confirm and expand previous studies on peak bone growth conducted in Caucasian cohorts, particularly sexually dimorphic and maturational effects. The significant “tracking” of bone measurements in this 6-yr follow-up study underscores the importance that osteoporosis prevention should begin in childhood and adolescence. Fengxiu Ouyang and Binyan Wang contributed equally to this article. Source(s) of support: This study is supported in part by grant R01 HD049059, R01 HL0864619 and R01 AR045651 from the National Institute of Health and by the Food Allergy Project.     

子宫内膜萎缩疗法治疗青春期功血362例临床研究

目的：探讨子宫内膜萎缩疗法治疗青春期功血（DUB）的止血效果。方法：将362例平均分为观察组（采用炔诺酮、戊酸雌二醇联合疗法止血）和对照组（单用炔诺酮子宫内膜萎缩疗法止血），两组各181例，比较两组的止血效果。结果：观察组和对照组止血有效率分别为96．13％（174／181）和92．27％（167／181），两组比较差异无统计学意义（踟105）；观察组和对照组控制出血时间分别为（28．69±14．87）h和（29．72±15．34）h，两组比较差异无统计学意义（踟．05）。观察组和对照组的完全止血时间分别为（32．80±19．10）h和（47．30±18．60）h，两组比较差异有统计学意义（／9〈0．05）。观察组和对照组的住院天数平均为（6．10±2．80）d和（6．9±2．60）d，观察组住院时间短于对照组（P〈0．01）。结论：炔诺酮止血疗法和炔诺酮、戊酸雌二醇联合疗法治疗青春期功血效果均较好，但炔诺酮、戊酸雌二醇联合疗法治疗效果更佳。     

社区人群痛风危险因素的病例对照研究

目的 探讨社区人群(20岁以上)痛风的危险因素。方法 采用1：3病例对照研究方法，进行单因素与多因素与多因素logistic回归分析。结果 经单因素筛选和多因素分析，在P=0．05水平，高尿酸(OR=8．601)、肥胖(OR=2．910)、伴有高血压病史(OR=2．330)是痛风的独立危险因素。结论 痛风是一种在遗传基础上的与环境和生活方式有关的疾病，改变生活方式、控制相关疾病可能预防或减少高尿酸血症的发生，进而减少痛风的发生。