Mode of Delivery and the Survival of Macrosomic Infants in the United States, 1995–1999

ABSTRACT: Background: Although increases in perinatal mortality risk associated with fetal macrosomia are well documented, the optimal route of delivery for fetuses with suspected macrosomia remains controversial. The objective of this investigation was to assess the risk of neonatal death among macrosomic infants delivered vaginally compared with those delivered by cesarean section. Methods: Data were derived from the U.S. 1995–1999 Linked Live Birth‐Infant Death Cohort files and term (37–44 wk), single live births to United States resident mothers selected. A proportional hazards model was used to analyze the risk of neonatal death associated with cesarean delivery among 3 categories of macrosomic infants (infants weighing 4,000–4,499 g; 4,500–4,999 g; and 5,000+ g). Results: After controlling for maternal characteristics and complications, the adjusted hazard ratio for neonatal death associated with cesarean delivery among the 3 categories of macrosomic infants was 1.40, 1.30, and 0.85. Conclusions: Although cesarean delivery may reduce the risk of death for the heaviest infants (5,000+ g), the relative benefit of this intervention for macrosomic infants weighing 4,000–4,999 g remains debatable. Thus, policies in support of prophylactic cesarean delivery for suspected fetal macrosomia may need to be reevaluated. (BIRTH 33:4 December 2006)     

人体蠕形螨的生物学研究

用透明胶带法观察蠕形螨在人体面部的寄生、逸出及其在体外的存活能力。结果表明：毛囊蠕形螨（Ｄｅｍｏｄ－ｅｘｆｏｌｉｃｕｌｏｒｕｍ，Ｄ．ｆ．）主要以颚体朝向毛囊底部寄生，且常常有多条群居现象，而皮脂蠕形螨，（Ｄｅｍｏｄｅｘｂｒｅｖｉｓ，Ｄ．ｂ．）一般为单条独居生活。两种人体蠕形螨昼夜均可主动爬出毛囊口出现在皮肤表面，Ｄ．ｆ．以白天１０００～１８００为逸出高峰；Ｄ．ｂ．则以夜间２２００～２００逸出最多。此外，蠕形螨在体外有较强的活动力和存活力。透明胶带法在人体蠕形螨的流行病学调查和生物学研究方面具有较高的应用价值     

The relationship between jaw deformity and scoliosis

Objectives To analyze the relationship between lateral displacement of the mandible and scoliosis. Methods From April 2002 through July 2003, we examined posteroanterior cephalometric radiographs and chest X-rays from 85 patients with jaw deformities and a control group of 20 patients with no jaw deformities. To measure the lateral shift of the mandible, we drew a horizontal baseline (X axis) on the cephalogram connecting the intersection of the external margins of the orbits and the most lateral points of the greater wings of the sphenoid. A vertical baseline (Y axis) was then marked perpendicular to the X axis, intersecting the ethmoid crista galli. Then, we measured the lateral displacement of the mandibular mentum from the Y axis. Displacement to the right was designated positive; that to the left was designated negative. Cobb's method was used to measure scoliosis curves on chest X-rays; the direction of the curve was designated similarly. Results Of the 85 patients with jaw deformity, 23 (27.1%) had a Cobb angle exceeding 10°. None of the control group had scoliosis exceeding 10°. No correlation was found between the direction of mandibular displacement and the direction of scoliosis. Conclusion This study suggests a relationship between jaw deformities and scoliosis, as scoliosis was found in 27.1% of the patients with a main complaint of jaw deformity.     

Fat and water separation in balanced steady-state free precession using the Dixon method.

In this work the feasibility of separating fat and water signals using the balanced steady-state free precession (SSFP) technique is demonstrated. The technique is based on the observation (Scheffler and Hennig, Magnetic Resonance in Medicine 2003;49:395-397) that at the nominal values of TE = TR/2 in SSFP imaging, phase coherence can be achieved at essentially only two orientations (0 degrees and 180 degrees ) relative to the RF pulses in the rotating frame, under the assumption of TR < T2, and independently of the SSFP angle. This property allows in-phase and out-of-phase SSFP images to be obtained by proper choices of the center frequency offset, and thus allows the Dixon subtraction method to be utilized for effective fat-water separation. The TR and frequency offset for optimal fat-water separation are derived from theories. Experimental results from healthy subjects, using a 3.0 Tesla system, show that nearly complete fat suppression can be accomplished.     

ANALYSIS OF BURIED BUMPER SYNDROME AFTER PERCUTANEOUS ENDOSCOPIC GASTROSTOMY DUE TO USE OF A BUTTON‐TYPE KIT

Background: Buried bumper syndrome (BBS) is a rare complication of percutaneous endoscopic gastrostomy (PEG). Along with the widespread use of the button‐type kit, BBS is encountered frequently. Methods: In the present study, we examined causes and treatments for BBS among 1400 patients who had undergone PEG. Results: The causes of BBS after PEG were classified into two categories: early causes consisted of wound infection, inappropriate size of kit and severe lordosis, while late causes were inappropriate exchange of kit, rough management or weight gain. The treatments for BBS could be determined by the degree of wound infection, fistula and burial of the bumper. Conclusion: We prepared a flowchart for replacement, by which BBS can be managed safely and quickly without surgical or endoscopic intervention.     

A simple and reliable method for rapidly harvesting split skin grafts in rats

A technique is presented which allows the rapid precise harvesting of split-skin grafts in rats. This technique uses the skin which would have been discarded in the formation of an open wound as a donor site thus reducing the overall assault on the animal.     

人工晶体植入屈光度的术前预选法：眼科超声仪36例对比研究

根据公认的眼科解剖学数据，提出后房型人工晶体植入屈光度的术前预测方法：IOL（D）=1．02（＋21D＋2X）。经人工晶体专用眼科A超36眼实测对比，无显著差异，认为在地市级医院和县级医院后房型人工晶体植入术推广中具有积极意义。     

Ontogenesis of the pyramidal cell of the mammalian neocortex and developmental cytoarchitectonics: a unifying theory.

The prenatal development of the mammalian neocortex has been analyzed, with the rapid Golgi method, in a variety of experimental animals (hamster, mouse, rat, and cat) and in humans. A new developmental conception of the structural organization of the mammalian neocortex is discussed. Neocortical development begins with the establishment of the primordial plexiform layer (PPL) which precedes and is a prerequisite for the subsequent formation of the cortical plate (CP). The formation of the CP occurs, in its entirety, within the PPL. During its development, three fundamental neuronal events occur: migration, early differentiation, and late maturation. All migrating neurons, travelling on radial glial fibers, reach layer I, develop an apical dendrite, and establish contacts with its elements. These newly differentiated neurons assume similar morphology resembling embryonic pyramidal cells. As such, an early differentiation stage common to all neurons of the CP is established. During the late maturation stage, all CP neurons acquire their specific phenotypic structural and functional features. Only pyramidal neurons retain and expand their original connections with layer I while other neuronal types lose these connections. The pyramidal cell is redefined in developmental terms: the neocortex's pyramidal cell is both structurally and functionally locked into position between layer I and the cortical depth of its soma. During mammalian evolution pyramidal cells are forced to structurally and functionally elongate their apical dendrite outwardly to accommodate an increasing amount of information without losing either their original anchorage to layer I or their cortical depth. This unique property of pyramidal neurons is considered to be a mammalian innovation. Based on these observations, a unifying developmental cytoarchitectonic theory applicable to all mammals is proposed. The theory considers the CP to be a mammalian innovation and to represent a single, stratified, and expanding telencephalic nucleus. The theory envisions the mammalian neocortex as an open biological system capable of progressive expansion by the recruitment and transformation of primitive neurons from upper layer II into pyramidal cells. Hence, the number of pyramidal cell strata increases over the course of mammalian phylogeny. The developmental roles of layer I in the migration of neurons, formation of the CP, unique morphology of pyramidal cells, and overall structural organization of the mammalian neocortex are emphasized.     

Path analysis and sib-pair linkage

When the distance between linked loci is expressed in terms of the correlation between the identity-by-descent (idb) values of the loci, then a path model may be used to order loci with data on sib-pairs and their parents. The relationship between the recombination fraction and the correlation coefficient is developed and a method for fitting a covariance matrix predicted by a specific ordering of loci to an observed covariance matrix is proposed. © 1993 Wiley-Liss. Inc.