Effects of PEEP and tolazoline infusion on respiratory and inert gas exchange in experimental meconium aspiration

Meconium aspiration syndrome often produces respiratory failure in the neonate. We utilized the multiple inert gas elimination technique to study the effects on respiratory and inert gas exchange of the application of positive end expiratory pressure or continuous infusion of tolazoline HCl. The application of PEEP, with the optimal level of PEEP defined for each animal, produced a decrease in AaDO2 and pulmonary shunt, without an increase in blood flow to low VA/Q areas, or an increase in dead space. Tolazoline infusion, at 2 mg/kg/hour, had no apparent effect on AaDO2 or shunt, or magnitude of low VA/Q regions. Tolazoline therapy was associated with an increase in heart rate and a decrease in systemic blood pressure. We conclude that immediate postaspiration application of PEEP, but not of tolazoline, will diminish pulmonary shunt without creating low VA/Q areas, and therefore will improve gas exchange in MAS.     

肾母细胞瘤69例临床分析

目的探讨肾母细胞瘤的诊断和治疗方案,以提高患儿存活率。方法回顾性分析1995年1月～2005年8月我院69例肾母细胞瘤病例的诊治过程。Ⅰ期25例,Ⅱ期23例,Ⅲ期17例,Ⅳ期4例。术前均经彩超,静脉尿路造影,CT及增强检查。均行手术治疗,完整切除瘤体肾60例,部分切除瘤体2例,7例行组织活检。术前化疗30例,所有病例术后均予化疗。结果本组病例2年存活率为81%。结论根治性切除是治疗肾母细胞瘤的关键,术前化疗有利于提高手术成功率,术后化疗可提高存活率。     

Congenital diaphragmatic hernia associated with homolateral upper limb malformation: a study of possible pathogenesis in four cases

Four cases of congenital diaphragmatic hernia associated with homolateral upper limb reduction deformities are presented and are analyzed in terms of their pathogenesis. Diaphragm and upper limb are supplied by adjacent segments of cervical neural crest, and the sensitive period for upper limb formation occurs during early neural crest development. The evidence supports the possibility of cervical neural crest injury as the underlying pathogenesis.     

Early versus delayed initiation of continuous negative pressure in infants with hyaline membrane disease.

Twenty-three infants with HMD of similar severity, who were less than 24 hours of age and who were breathing spontaneously, were divided by random numbers into early and delayed CNP groups. The infants who were treated with CNP before their PaO2 was less than 50 mm Hg while breathing 70% oxygen experienced a significantly greater increase in PaO2 in response to the initiation of CNP, required less time with O2 therapy, required no mechanical ventilation, and had fewer complications. Based on these results, it is suggested that CNP be initiated in infants with HMD, who are less than 24 hours of age and are breathing spontaneously, before the PaO2 becomes less than 50 mm Hg on 70% O2.     

SEM-dissection of a human embryo derived from an ectopic pregnancy

A 6.5-week-old human embryo with an approximate crown-rump length of 13.2 mm was obtained from a tubal pregnancy. Two hours before surgical removal, the embryo was imaged with real time ultrasound and was noted to have rhythmic cardiac motion. Subsequent to surgical removal, the embryo was dissected free from the placenta and prepared for routine scanning electron microscopic (SEM) studies. Progressive stages of dissection with microsurgical instruments followed by SEM photography elucidated the three-dimensional aspects of embryonic development of many structures, including the lens placode, tongue bud, Rathke's pouch, atrial and ventricular foramina, primitive intestinal loop and undifferentiated external genitalia. Almost certainly, such clear views of dissected structures can contribute to our understanding of human embryonic development.