Reductions in Heel Bone Quality Across Gestation Are Attenuated in Pregnant Adolescents With Higher Prepregnancy Weight and Greater Increases in PTH Across Gestation

Few studies have examined the effect of maternal calcium intake and vitamin D status on bone health across gestation in pregnant adolescents. This study aimed to characterize maternal bone quality and determinants of bone‐quality change across gestation in pregnant adolescents. Healthy pregnant adolescents (n = 156; aged 13 to 18 years) with singleton pregnancies and at 12 to 30 weeks gestation at enrollment were recruited from two urban maternity clinics in Baltimore, MD, and Rochester, NY, for this prospective longitudinal study. Maternal serum was collected at midgestation and at delivery for assessment of bone biomarkers and calcitropic hormones. Maternal bone quality (assessed by heel ultrasound) and sonographic fetal biometry were measured up to three times across pregnancy. Racially diverse teens (64.7% African American, 35.3% white) were followed from 21.0 (interquartile range [IQR] 17.3, 27.0) weeks of gestation until delivery at 40.0 (IQR 39.0, 40.7) weeks. Significant decreases in calcaneal speed of sound (SOS), broadband ultrasound attenuation (BUA), and quantitative ultrasound index (QUI) (–9.2 ± 16.1 m/s, –3.2 (–8.0, 2.1) dB/MHz and –5.3 ± 8.8, respectively) were evident across pregnancy. Multivariate analysis controlling for baseline measures and measurement intervals was used to identify independent predictors of normalized (per week) calcaneal bone loss. Weekly decreases in bone quality were not significantly associated with maternal calcium intake or 25(OH)D concentration. Greater weekly reductions in calcaneal bone quality were evident in teens with lower prepregnancy weight (BUA, p = 0.006 and QUI, p = 0.012) and among those with lower weekly increase in PTH (SOS, p = 0.046). Overall, significant decreases in calcaneal bone quality occurred across pregnancy in adolescents, but the magnitude of this loss was attenuated in those with greater prepregnancy weight and weekly increases in PTH. Further studies are needed to understand the role of elevated PTH and greater prepregnancy weight in preserving adolescent bone during pregnancy. © 2014 American Society for Bone and Mineral Research.     

育龄女性心瓣膜置换术后的抗凝治疗

目的：探讨心瓣膜置换术后抗凝治疗对妊娠分娩，月经量过多，避孕失败后人流产手术等的影响，调整抗凝方案，方法回顾我院1989年2月至1998年2月292例15－40岁育龄女性心瓣膜置换术后的抗凝治疗，术后随访时间0．5－9年，比较不同抗凝方案对育龄女性术后的生理影响，结果：调整育龄女性心瓣膜置换术后抗凝方案，减少华法林用量，调控凝血酶原时间比值（PTR）为1．3－1．5，国际正常比值(INR）为2－3（国际敏感指数ISI＝2．4校正），既能有效预防血栓栓塞，又能提高术后妊娠分娩的安全性。结论：调整抗凝方案，减少华法林用量，能有效改善心瓣膜置换术后育龄女性的生活质量。     

Muscle-Bone Interactions Across age in Men

This study examined the relationship of muscular strength and lean tissue with age-related patterns in bone mineral density (BMD) in men 20-81 years of age. Subjects were assigned to one of three age groups, Young Men (YM), (n = 25, 20-39 yrs), Middle-aged Men (MM) (n = 24, 40-59 yrs), and Older Men (OM) (n = 23, 60-81 yrs). Isotonic and isokinetic strength was assessed for the quadriceps and hamstrings muscle groups. DXA (Lunar DPX-IQ) was used to measure spine, hip, and total body BMD and body composition. OM had significantly lower (p < 0.05) total lean body mass (LBM) than MM and lower leg lean mass (LM) than YM and MM. OM had significantly lower (p < 0.01) BMD than YM and MM at the femoral neck and total hip sites and a higher proportion of OM were osteopenic and osteoporotic at the total hip site. Isotonic and isokinetic strength for both muscle groups was positively related (p < 0.05) with the hip BMD sites (r = 0.38-.67). Leg LM also was positively related to hip BMD (r = 0.37-.58). Multiple Regression analyses determined that age and lean mass (LBM or leg LM) were significant predictors (p < 0.05) of femoral neck, and total hip BMD, while lean mass (LBM or leg LM) was a significant predictor (p < 0.05) of BMD at the spine and trochanter sites. Isotonic and isokinetic leg strength variables were significant predictors (p < 0.05) of the total body, total hip and trochanter BMD. In conclusion, leg strength, leg LM, and total LBM were significant predictors of BMD in men, independent of age. These findings emphasize the importance of maintaining lean body mass for the bone health of aging men.

Key Points

• Osteoporosis is an important health problem for men.
• Bone mineral density for the hip was lower in older men compared to their younger and middle-age counterparts. There were age group differences in the prevalence of osteopenia and osteoporosis for the total hip BMD site.
• Muscular strength and bone-free lean body mass were significant predictors of hip BMD, independent of age, thus reinforcing the importance of contractile forces on skeletal health.
• Maintenance of muscle mass and strength should be encouraged in aging men for the reduction of osteoporosis risk.

Key words: Lean body mass, osteopenia, osteoporosis, muscle strength, bone density     

跨ABO血型肾移植

ABO血型障碍是抑制肾移植发展的主要因素,通过各种措施来控制和避免跨ABO血型肾移植术后的排斥反应,延长移植肾的存活时间,保护移植肾功能,有利于解决移植肾供体短缺的状况.本文就跨ABO血型肾移植的历史、抗排斥策略、优越性、存在问题和发展方向进行综述.     

Laparoscopic Removal of Abdominal Cerclage at 19 Weeks' Gestation

We discuss laparoscopic removal of an abdominal cerclage in a 39-year-old woman, gravida 4, para 0, abortus 3, who presented at 19 weeks'' gestation with ruptured membranes. This patient had a failed previous vaginal cerclage. An abdominal cerclage was performed at the time of abdominal myomectomy. A subsequent pregnancy was diagnosed, with ruptured membranes at 19 weeks'' gestation, and the patient opted for pregnancy termination. After laparoscopic removal of the cerclage, cervical laminaria were placed, and the patient underwent an uncomplicated dilation and curettage procedure the following day.     

Successful Treatment of a Gravida with Acute A Type Aortic Dissection in Late Gestation

Abstract This case report describes a woman at 35 weeks gestation, who presented with an acute type A aortic dissection involving the total aortic arch and descending aorta. She underwent a successful ascending aorta replacement, total arch replacement, and stented elephant trunk implantation at the time of cesarean section with favorable maternal and fetal outcomes . (J Card Surg 2012;27:728‐730)     

Gas Supply Across Membranes in Bioreactors for Hepatocyte Culture

The conditions required for hepatocyte cultures is a main topic in the development of bioreactors for hybrid liver support systems. The detoxification of ammonia and the synthesis of urea due to primary isolated hepatocytes was measured in order to compare two different models of gas supply in bioreactors: (a) indirect medium oxygenation and (b) direct membrane-contact oxygenation of the hepatocytes using polypropylene membranes. Increasing oxygen pressure promoted cell function. At day 6 of culture, urea synthesis was 0.8 +/- 0.3 mM in 21% of O2 cultures and 1.5 +/- 0.1 mM in oxygenated cultures. Alkalosis due to CO2 loss decreased ammonia metabolism. The direct membrane-contact oxygenation resulted in enhanced cell metabolism in comparison to medium oxygenation: urea synthesis at day six was 1.42 +/- 0.2 mM in 21% O2 cultures. Polypropylene oxygenation membranes proved to be sufficient for hepatocyte adhesion. Two functions can be integrated in one element in liver support systems using the investigated polypropylene membrane and the direct membrane-contact oxygenation: oxygenation with physiological oxygen pressure in bioreactors due to gas supply across the membrane and adhesion of hepatocytes in bioreactors on the membrane.