妊娠8~11周两胚胎长度差异对双胎反向动脉灌注序列征的预测价值

目的 探讨妊娠8~11周两胚胎长度差异对双胎反向动脉灌注序列征(TRAPS)的预测价值。方法 选取我院行产前超声诊断并经引产或产后病理证实的TRAPS病例37例(TRAPS组),另选同期产前超声检查及产后随访未见明显结构异常的早孕期单绒毛膜双胎妊娠42例(对照组);比较两组妊娠8~11周两胚胎相差长度及超声孕周相差天数。绘制受试者工作特征(ROC)曲线分析两胚胎相差长度及超声孕周相差天数在早孕期预测TRAPS的诊断效能。结果 TRAPS组与对照组两胚胎超声孕周相差天数分别为(9.1±6.9)d、(1.6±1.5)d,两胚胎相差长度分别为7.9(3.8,17.2)mm、0.9(0.1,3.4)mm,两组比较差异均有统计学意义(均P<0.05)。ROC曲线分析显示,当两胚胎超声孕周相差天数≥5 d、两胚胎相差长度≥4.5 mm时预测TRAPS的曲线下面积、灵敏度、特异度、阳性预测值、阴性预测值分别为0.65、67.6%、97.6%、92.3%、77.3%和0.66、75.7%、97.5%、87.8%、82.2%。结论 妊娠8~11周胚胎长度差异对早期预测TRAPS有一定的临床价值。

鸽子种蛋孵化过程胚胎生长发育特点及失重率变化规律

为了研究种鸽蛋人工孵化过程胚胎生长发育的特点和失重率的变化规律,试验选择了500枚温氏王鸽种蛋进行人工孵化,每日测量胚胎重量、胚胎长度和气室直径,计算失重率。结果表明:15胚龄转盘时失重率为12.7%。气室直径变化呈现三个阶段,即1~6天为快速上升期,7~11天为平台期,12~13天为二次快速上升期。胚胎重量生长呈现三个阶段,即8胚龄之前胚胎重量增加缓慢,8~14胚龄胚胎重量增长迅速,14胚龄之后胚胎快速生长,经过1 d时间,体重几乎再次翻倍,基本达到出壳体重水平。胚胎长度生长呈现三个阶段,即第1个生长阶段为8胚龄之前,该阶段胚胎持续匀速生长;第2阶段为9~11胚龄,该阶段胚胎长度生长几乎停滞;第3阶段为11胚龄之后,胚胎持续快速生长至70 mm。说明在孵化过程中种鸽蛋的失重率呈现线性变化规律。

Effects of Salinity on Embryonic Development, Survival, and Growth of Crassostrea hongkongensis

This study examined the effects of salinity on embryonic development, survival, and growth of the Hong Kong oyster Crassostrea hongkongensis. The embryos, larvae, and juveniles of C. hongkongensis were held in artificial seawater at three different salinities(low, 15; medium, 23; and high, 30) to determine the optimum hatchery and nursery conditions for mass production of the seeds. Results showed that the percentage production of straight-hinged larvae from fertilized eggs was significantly lower at the high salinity than at the low- and medium-salinities(P < 0.05). The survival rates of larvae and juveniles differed significantly among the three salinity trials, with the highest survival rate observed at the low salinity(P < 0.05). The shell height of larvae was significantly larger at the low salinity than at the high and medium salinities from days 9 to 15(P < 0.05), whereas that of juveniles was significantly larger at the low salinity than at the high and medium salinities on day 70(P < 0.05). These results indicate that the larvae and juveniles of C. hongkongensis are tolerant to a wide range of salinities(15 to 30), but show better growth and survival at relatively low salinities. Thus, it is recommended to use relatively low salinities in hatchery and nursery systems for improved yields of C. hongkongensis.