Role of low placental share in twin-twin transfusion syndrome complicated by intrauterine growth restriction

Objectives

Prior studies have demonstrated that donor twin survival following treatment of twin-twin transfusion syndrome (TTTS) was highly associated with donor intrauterine growth restriction (IUGR). Here, we hypothesized that donor IUGR may be attributed in part to low placental share.

Study design

The study population consisted of all patients who underwent laser treatment for TTTS at a single institution between 2006-2010. Only those pregnancies with dual survival at birth were included so that placental share information could be interpreted. We examined the relationships between Quintero Stage (with separate analysis of Stage III patients with critically abnormal donor Doppler findings) and low placental share (defined as ≤ 30%) with IUGR (<10th percentile) using chi-square analysis and multivariable logistic regression modeling.

Results

Of 210 patients treated, 159 (75.7%) had dual survivors at birth. Of these, placental share was documented in 90 cases (56.6%). Twenty-seven (30.0%) had low placental share, and 37 (41.1%) had IUGR. IUGR was associated with low placental share (63.0% vs. 31.7%, P = 0.0116). IUGR was also associated with Stage III patients (57.4% vs. 23.3%, P = 0.0021), and in particular with Stage III patients with donor involvement (77.8% vs. 25.4%, P < 0.0001). In logistic regression modeling, both low placental share and Stage III with donor involvement were independent risk factors for IUGR (OR = 3.5 [1.2-10.3], P = 0.0206, and OR = 10.1 [3.3-30.6], P < 0.0001, respectively).

Conclusions

Donor IUGR in TTTS pregnancies appears to be associated, in part, with low placental share.     

Airborne particles of the california central valley alter the lungs of healthy adult rats

Epidemiologic studies have shown that airborne particulate matter (PM) with a mass median aerodynamic diameter < 10 microm (PM10) is associated with an increase in respiratory-related disease. However, there is a growing consensus that particles < 2.5 microm (PM2.5), including many in the ultrafine (< 0.1 microm) size range, may elicit greater adverse effects. PM is a complex mixture of organic and inorganic compounds; however, those components or properties responsible for biologic effects on the respiratory system have yet to be determined. During the fall and winter of 2000-2001, healthy adult Sprague-Dawley rats were exposed in six separate experiments to filtered air or combined fine (PM2.5) and ultrafine portions of ambient PM in Fresno, California, enhanced approximately 20-fold above outdoor levels. The intent of these studies was to determine if concentrated fine/ultrafine fractions of PM are cytotoxic and/or proinflammatory in the lungs of healthy adult rats. Exposures were for 4 hr/day for 3 consecutive days. The mean mass concentration of particles ranged from 190 to 847 microg/m3. PM was enriched primarily with ammonium nitrate, organic and elemental carbon, and metals. Viability of cells recovered by bronchoalveolar lavage (BAL) from rats exposed to concentrated PM was significantly decreased during 4 of 6 weeks, compared with rats exposed to filtered air (p< 0.05). Total numbers of BAL cells were increased during 1 week, and neutrophil numbers were increased during 2 weeks. These observations strongly suggest exposure to enhanced concentrations of ambient fine/ultrafine particles in Fresno is associated with mild, but significant, cellular effects in the lungs of healthy adult rats.     

游离足趾移植术中Ⅱ趾血供系统的特点

目的：游离足趾移植是拇指Ⅱ类以上缺损再造术的首选。分析与Ⅱ趾移植相关的足部供血系统的血管走行、分支情况及变异程度，并提出临床应用中为保证手术成功而采取的相应对策。方法：对1978—03/2007—06天津医院手、显微外科收治的91例Ⅱ趾移植再造拇（手）指患者进行回顾性分析，所有病例均为ⅡB-ⅢB类型拇指缺损，均为择期手术，对治疗方案知情同意。术中遇第一跖背动脉纤细型，采取足背动脉-足底深支-第一跖底动脉的第2套供血系统。当第一跖背动脉走行不定而误伤时，手术继续进行，完整切取Ⅱ趾后，进行第一跖背动脉吻合修复。注意第一跖背动脉至足趾的分支解剖特点，辨清与Ⅱ趾的关系，采取不同的手术对策。结果：91例拇指缺损患者获得了97．8％的成活率及优良的外形与功能恢复，移植术中Ⅱ趾的使用率是100％。Ⅱ趾的血供系统特点：①由足背动脉发出的第二跖背动脉很少见，足背动脉的弓状动脉分支也很少见。②第一跖背动脉起始、走行、口径虽不恒定，但是有章可循。③第一跖背动脉终末交通支及至Ⅱ趾的分支情况分为3型，各型对Ⅱ趾的血供也有其不同特点。结论：全面掌握与Ⅱ趾移植相关的足部供血系统的解剖特点，术中仔细游离并采取相应的处理方法，是保证手术成功的关键。     

Physicians' perspectives on the uncertainties and implications of chromosomal microarray testing of children and families

Chromosomal microarray analysis (CMA) has improved the diagnostic rate of genomic disorders in pediatric populations, but can produce uncertain and unexpected findings. This article explores clinicians' perspectives and identifies challenges in effectively interpreting results and communicating with families about CMA. Responses to an online survey were obtained from 40 clinicians who had ordered CMA. Content included practice characteristics and perceptions, and queries about a hypothetical case involving uncertain and incidental findings. Data were analyzed using nonparametric statistical tests. Clinicians' comfort levels differed significantly for explaining uncertain, abnormal, and normal CMA results, with lowest levels for uncertain results. Despite clinical guidelines recommending informed consent, many clinicians did not consider it pertinent to discuss the potential for CMA to reveal information concerning biological parentage or predisposition to late‐onset disease, in a hypothetical case. Many non‐genetics professionals ordering CMA did not feel equipped to interpret the results for patients, and articulated needs for education and access to genetics professionals. This exploratory study highlights key challenges in the practice of genomic medicine, and identifies needs for education, disseminated practice guidelines, and access to genetics professionals, especially when dealing with uncertain or unexpected findings.