1. Development of Esophageal Peristalsis in Preterm and Term Neonates
Annamaria Staiano, Gabriella Boccia, Gennaro Salvia, Donato Zappulli, Ray E. Clouse 
Gastroenterology 
Volume 132, Issue 5, Pages (May 2007)
DOI: /j.gastro
Copyright © 2007 AGA Institute Terms and Conditions

2. Figure 1
Demonstration of the typical peristaltic pressure segments in a term infant (left panel) and a preterm infant (30 weeks gestational age at examination; right panel). Isobaric contour lines begin 5 mm Hg above gastric baseline pressure in this and other Figures. In the left panel, the catheter is in the proximal position, and only the upper esophageal sphincter and part of the esophageal body are visualized. The first pressure trough (1) separating the first segment (striated muscle) from the second segment (upper portion of the smooth muscle esophagus) and the second pressure trough (2) separating the smooth muscle segments are seen. Locations of these troughs were verified when the catheter was moved to the distal position. In the right panel, the esophagus was sufficiently short to visualize all pressure troughs (1–3) and segments in one catheter position. (Sphincter locations were verified by catheter movement.) Lengths of the individual segments relative to total esophageal body length are shown for the right panel as calculated for this swallow.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions

3. Figure 2
Two swallows from a term neonate demonstrating presence of the first segment in one swallow and absence in another. The second segment is well seen on both swallows with the catheter in a proximal recording position.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions

4. Figure 3
This swallow from a preterm neonate (35 weeks gestational age at examination) shows the entire esophageal body with the catheter in one position. The first segment is not observed at its usual location extending distal to the UES, the second segment is well developed, and the third segment is missing. Location of the second trough was identified from other swallows that contained the second and third segments.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions

5. Figure 4
Presence of the first and second segments in a preterm (left panel) and term neonate (right panel) with absence of the third segment above the LES. The second segment overlaps into the region of the absent third segment in each case. The location of the second pressure trough (2) is derived from its average location on remaining swallows in which the trough could be identified. Swallow onset was determined by distinctive electromyographic deflections when the UES was not present on the map.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions

6. Figure 5
Percentage of subjects in each group demonstrating pressure segments following at least 50% of swallows (grade 2 or 3; solid bars) or following at least 80% of swallows (grade 3 only; open bars). The second segment was more commonly observed than either the first or third segment in preterm and term neonates. *P < .01 compared with the first and third segments in the same subject group. **P < .05 compared with the third segment in the same subject group.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions