Prenatal Sonography in Suspected Proximal Gastrointestinal Obstructions: Diagnostic Accuracy and Neonatal Outcomes

BackgroundThe purpose of this study was to assess diagnostic accuracy and neonatal outcomes in fetuses with a suspected proximal gastrointestinal obstruction (GIO).MethodsAfter IRB approval, a retrospective chart review was conducted on prenatally suspected and/or postnatally confirmed cases of proximal GIO at a tertiary care facility (2012–2022). Maternal-fetal records were queried for presence of a double bubble ± polyhydramnios, and neonatal outcomes were assessed to calculate the diagnostic accuracy of fetal sonography.ResultsAmong 56 confirmed cases, the median birthweight and gestational age at birth were 2550 g [interquartile range (IQR) 2028–3012] and 37 weeks (IQR 34–38), respectively. There was one (2%) false-positive and three (6%) false-negatives by ultrasound. Double bubble had a sensitivity, specificity, positive predictive value, and negative predictive value for proximal GIO of 85%, 98%, 98%, and 83%, respectively. Pathologies included 49 (88%) with duodenal obstruction/annular pancreas, three (5%) with malrotation, and three (5%) with jejunal atresia. The median postoperative length of stay was 27 days (IQR 19–42). Cardiac anomalies were associated with significantly higher complications (45% vs 17%, p = 0.030).ConclusionsIn this contemporary series, fetal sonography has high diagnostic accuracy for detecting proximal gastrointestinal obstruction. These data are informative for pediatric surgeons in prenatal counseling and preoperative discussions with families.Level of EvidenceDiagnostic Study, Level III.     

Visumax飞秒激光辅助制瓣LASIK术中不透明气泡层及相关因素

目的：研究Visumax飞秒激光辅助的准分子激光原位角膜磨镶术（LASIK）术中不透明气泡层（OBL）产生的类型、相关影响因素及其临床意义。方法：回顾性分析。收集2016 年7 月1 日至8 月20 日在南京医科大学附属眼科医院行飞秒LASIK的患者154 例（300 眼）的临床资料，等效球镜度为（-5.88±1.51）D。飞秒激光采用Zeiss公司 Visumax飞秒激光仪，将术中产生的OBL分为瓣外OBL、瓣内快速OBL和瓣内慢速OBL。300 眼按角膜曲率平均K值分为A组（<42 D）、B组（42～46 D）和C组（>46 D）；按角膜瓣的厚度分为D组（100 μm）、E组（110 μm）和F组（120 μm）；按角膜厚度分为G组（<500 μm）、H组（500～540 μm）和I组（>540 μm）。统计不同角膜曲率、角膜瓣厚度、角膜厚度情况下3 种OBL产生的比例，并采用多元Logistic回归模型进行统计分析。结果：300 眼均发生OBL。以瓣外OBL作为参照，角膜瓣越薄，越容易出现瓣内快速OBL（r=-0.719，P=0.034）和瓣内慢速OBL（r=-0.875，P=0.044）。以瓣内慢速OBL作为参照，角膜曲率越高，越容易出现瓣内快速OBL（r=0.923，P=0.046）；角膜瓣越厚，越容易出现瓣外OBL（r=0.897，P=0.044）。结论：OBL的产生与角膜曲率、角膜瓣厚度、角膜厚度均存在一定的相关性，但瓣外OBL、瓣内快速OBL和瓣内慢速OBL对Visumax飞秒激光辅助的LASIK术后视觉质量的影响及远期疗效仍有待进一步观察研究。     

钛瓷瓷裂的临床研究和原因分析

目的：分析钛-瓷修复体失败的原因。方法：对38例瓷裂的钛-瓷修复体进行分析：①肉眼观察烤瓷崩瓷部铸件的表面颜色并用便携式厚度测试仪测量其厚度，与未发生瓷裂的正常镰铬合金烤瓷比较；②观察烤瓷崩瓷的部位；③X-ray检测铸件内部气孔。结果：本组崩瓷的钛-瓷修复体，其断层或有气泡，或金属表面氧化层明显增厚（P〈0．05）。而且，所有发生崩瓷的部位均在受力点或因技工本身操作不当引起。结论：钛-瓷修复体失败的原因与加工过程中工艺、瓷的受力点以及与钛元素化学性能有关。     

去势后大鼠海马结构一氧化氮合酶阳性神经元的变化

目的：观察去势后大鼠海马结构一氧化氮合酶（NOS）阳性神经元的变化。方法：用黄递酶组织化学染色方法观察切除双侧卵巢后雌后SD大鼠海马结构NOS阳性神经元的形态，分布的变化，并进行计算机图像分析。结果：去势后海马结构NOS阳性神经元分布变化有区域差异性；NOS阳性神经元在下托、海马（CA）一区邻近下托的部分、CA三区、CA四区（CA4）和齿状回（DG）数目明显减少，而在CA二区数目明显明显增多，CA4和DG的NOS阳性神经元平均密度降低，胞体的平均周长和平均截面积都明显减少。结论：雌激素可能通过影响海马结构NOS的表达来影响学习和记忆。     

Development of the blood-testis barrier in the domestic fowl (Gallus domesticus)

The formation of the blood-testis barrier (BTB) in the domestic fowl was studied at the electronmicroscopic level employing lanthanum as a tracer. No effective barrier could be demonstrated in testes before puberty, although several components of the Sertoli junctional complex such as focal tight junctions and desmosomes were already existent. The time of onset of meiosis after hatching showed great individual variation and meiosis did not occur synchronously in the tubules of a given testis. An effective barrier could first be detected in tubules containing early spermatids, and in which spermatogonia and primary spermatocytes at the leptotene stage were still within the open compartment. Thus, barrier formation was correlated with the occurrence of haploid germ cells. Complete compartmentation of seminiferous tubules, leaving only spermatogonia within the open compartment, was attained in tubules containing elongated spermatids of the maturation phase. In these tubules, primary spermatocytes at the leptotene stage were situated in an intermediate compartment.     

Growth cones and axon trajectories of a sensory pathway in the amphibian spinal cord

Central axons of sensory ganglion (SG) neurons of the Xenopus tail enter the spinal cord via the ventral roots and travel dorsally and rostrally following a diagonal course within the lateral marginal zone (LMZ) to reach the dorsolateral fasciculus (DLF) (Nordlander et al.: Brain Res., 440:391-395, 1988). Axons are dispersed as they cross the cord. At the DLF they turn and travel together rostrally, sharing the fascicle with axons of primary sensory neurons (Rohon-Beard cells) already present in the tract. In this paper we analyze the growth patterns of the central projections of SG axons in the tail by using HRP applied to proximal branches of tail spinal nerves. Growth cones of the diagonal route are variable in configuration, often bearing processes that spread within the LMZ. Once the DLF, growth cones change shape, becoming distinctly linear. While growth cones navigating the diagonal part of the route never contact or fasciculate with other diagonal SG axons, SG growth cones and axons of the DLF are more closely associated with their fellows. Measurements of the slopes of SG axons in the diagonal route indicated a limited range with a mean of 23 degrees with respect to the cord axis. On the basis of these observations, we conclude that 1) navigational patterns for growth cones of this pathway differ for the diagonal versus the DLF part of its course, and 2) fasciculation is not a mechanism used by SG axons to reach the DLF, but that instead, each axon is able to find its way independently.     

Angular bundle kindling is accelerated in rats with a genetic predisposition to acoustic stimulus-induced seizures

Limbic kindling was examined in genetically epilepsy-prone (GEPR) and non-epileptic control rats. The early stage of kindling development was accelerated in both groups of GEPR rats compared to controls. Later stages of kindling were accelerated in GEPR-9 but not GEPR-3 rats. These results indicate that GEPR rats have an enhanced susceptibility to limbic kindling and suggest that limbic brain alterations may contribute to acceleration of the early stage kindling development in GEPR rats.     

复合干细胞生物陶瓷在裸鼠异位成骨中的评价

目的 研究h-BMP-2基因转染骨髓间充质干细胞(BMSCs)在复合煅烧骨、β-TCP或直接植入裸鼠股部后的成骨能力。方法 通过影像学、组织学和形态计量学等方法,观察未经诱导、OS液诱导和h-BMP-2基因转染BMSCs在复合煅烧骨,或多孔β-TCP后植入裸鼠皮下,或直接制成细胞悬液注入,在4、8、12周诱导成骨和材料降解情况。结果 在裸鼠皮下,单纯生物陶瓷不能诱导成骨,而复合了未诱导、OS液诱导和h-BMP-2基因转染BMSCs的生物陶瓷均能成骨,成骨量为h-BMP-2基因转染组>OS液诱导组>未经诱导组(P<0.05),B-TCP可随骨长入而降解;注入裸鼠肌肉的OS液诱导的和h-BMP-2转染的BMSCs均能诱导成骨,而未经诱导MSCs则不能成骨。结论 复合人BMP基因转染BMSCs的β-TCP是一种理想的骨修复材料。     

Distinct osteogenic mechanisms of bones of distinct origins

Mammalian bones have three distinct origins (paraxial mesoderm, lateral plate mesoderm, and neural crest) and undergo two different modes of formation (intra-membranous and endochondral). Bones derived from the paraxial mesoderm and lateral plate mesoderm mainly form through the endochondral process. During this process, hypertrophic chondrocytes play a vital role in inducing both osteogenesis and angiogenesis. One of the essential osteogenic factors secreted from hypertrophic chondrocytes is Indian hedgehog (Ihh). In contrast, bones derived from the neural crest mainly form through the intramembranous pro-cess and do not require Ihh. Thus, depending on their origin, bones have distinct signaling properties, which need to be considered in the research and application of bone biology.Presented at the 18th Annual Research Meeting of the Japanese Orthopaedic Association, Kitakyushu, Japan, October 17, 2003     

胆碱酯酶重活化剂PAM类构型、构象问题

本文参考X-衍射数据,采用MNDO程序计算了不同构型、构象PAM类的生成热,结合核磁共振数据讨论了PAM类构象等问题.结果表明,PAM类在水溶液中:顺式体肟基可以自由旋转,任何一种构象都可能成为药效构象;反式体肟基本不可能存在稳定的平面构象,其药效构象只能是优势构象.用MNDO程序中反应途径的计算法,还计算了顺、反式肟基构型相互转变的势垒,为探讨PAM类重活化机理提供了一定的参考.