BACKGROUND: In this study we aimed to describe the morphological and pathogenetic differences between tracheal agenesis and tracheal atresia, which are not clearly distinguished from each other in the literature, and to contribute thereby to the understanding and management of these conditions. Both tracheal agenesis and tracheal atresia represent rare disorders of still unknown aetiology that cannot be detected by prenatal ultrasound. If the affected foetuses survive until birth these conditions result in respiratory failure and in futile attempts to rescue the infant\'s life.
RESULTS: Autopsies and genetic analyses, including singleton or trio exome sequencing, were performed on five neonates/foetuses with tracheal agenesis and three foetuses with tracheal atresia. Tracheal agenesis was characterized by absence of the sublaryngeal trachea and presence of a bronchooesophageal fistula and by pulmonary isomerism and occurred as an isolated malformation complex or as part of a VACTERL association. Special findings were an additional so-called \'pig bronchus\' and a first case of tracheal agenesis with sirenomelia. Tracheal atresia presenting with partial obliteration of its lumen and persistence of a fibromuscular streak resulted in CHAOS. This condition was associated with normal lung lobulation and single, non-VACTERL type malformations. Trio ES revealed a novel variant of MAPK11 in one tracheal agenesis case. Its involvement in tracheooesophageal malformation is herein discussed, but remains hypothetical.
CONCLUSIONS: Tracheal agenesis and tracheal atresia represent different disease entities in terms of morphology, pathogenesis and accompanying anomalies due to a primary developmental and secondary disruptive possibly vascular disturbance, respectively.

OBJECTIVE: To evaluate the effects of intrathecal administration p38β antisense oligonucleotide on the development of bone cancer pain rats.
METHODS: Forty female SD rats weighing 180~220 g were randomly divided into 4 groups (n = 10 each): Group A (control group): intra-tibial injection of 3 μl Hank\'s solution; group B (model group): intra-tibial injection of 3 μl MADB-106 mammary gland carcinoma cells of rats (4.8 × 10(3)/μl); group C (p38β-SODN 20 μg); group D (p38β-ASODN 20 μg). The model procedures in group C and D were same to those in the group B. From the 14th day after operation, p38β-SODN 20 μg and p38β-ASODN 20 μg were respectively intrathecally administrated in group C and D once daily for 6 days whereas normal saline was for group A and B. Mechanical withdrawal threshold and radiant heat threshold of rat hind paws were measured before operation and every other day until 22 d of post-operation. The lumbar 4-6 spinal cord was removed on the 22(nd) day. The expression of spinal p38β protein was determined by Western blot.
RESULTS: No significant differences in mechanical withdrawal threshold and radiant heat threshold were found at all time points in control group. During the first 6 days after operation there were obvious differences in radiant heat stimulus between control group between the other groups (P < 0.05); During 14-22 days after operation, mechanical pain threshold and radiant heat threshold between p38β-SODN group and Model group were significantly changed compared with that in control group (P < 0.05). However, the differences were not remarkable between control group and p38β-ASODN group (P > 0.05). The expression of p38β protein in lumbar spinal cord was significantly higher between p38β-SODN group and Model group than that in control group (P < 0.05). There was no significant difference in p38β protein expression between p38β-ASODN group and control group (P > 0.05).
CONCLUSIONS: Hyperalgesia induced by bone cancer can be inhibited by intrathecal administration of p38β antisense oligonucleotide, which is achieved by reducing expression of p38β protein.