Comparison of neuropeptide Y, protein gene product 9.5, and acetylcholinesterase in the diagnosis of Hirschsprung's disease.

We compared the results of acetylcholinesterase (AChE) staining of mucosal rectal biopsy specimens with those using neuropeptide Y (NPY) and protein gene product 9.5 (PGP9.5) in biopsies from 68 patients. Thirty-three did not have Hirschsprung's disease (HD), 28 had proven HD, and biopsies from 7 patients had shown a slight increase in AChE stain but the patients did not have HD. In our hands, AChE stain was superior to the other two; it was easier to read and gave the most accurate results with no false-positive cases and only two instances in which the findings were suggestive but not diagnostic. Neuropeptide Y and PGP9.5 have the advantage that they can be used in paraffin-embedded material. With NPY, the results are closer than with PGP9.5 to those obtained with the AChE. Protein gene product 9.5 had the highest incidence of false-positive and false-negative results, but it stains nerve fibers and all neurons intensely and may be useful in the assessment of increased or decreased amounts of neural elements in the bowel.

Microdissection study of the myenteric plexus in acardia, ataxia-telangiectasia, cystic fibrosis, extrahepatic biliary atresia, pediatric AIDS and Werdnig-Hoffmann disease.

Microdissection-point count morphometric study of the myenteric (Auerbach) plexus or esophagus, small intestine, and colon was done for infants and children with acardia (2), ataxia-telangiectasia (5), cystic fibrosis of the pancreas (CFP) (25), extrahepatic biliary atresia (EBA) (17), pediatric AIDS (10), and Werdnig-Hoffmann disease (WHD) (8). Values for fractional area of neural tissue in the plane of the plexus were compared to those of control patients in same age range as those in each disease category by t-test. Statistically abnormal values included low values for small intestine and colon in Werdnig-Hoffmann disease, high values for small intestine and colon in biliary atresia, and high value for colon but a low value for small intestine in cystic fibrosis. Values for all three loci were within the normal range for ataxia telangiectasia and pediatric AIDS. The mechanisms of the low value for small and large intestines in WHD, which causes chronic constipation as a result of skeletal muscle weakness, and of the high values for colon in CFP and EBA, both causing malabsorption with bulky stools, are unclear. The value for small intestine in acardia was normal for term but lower than expected for fetal bowel of the same size, possibly because of reduced neural crest inflow to the fetal bowel.

Diagnostic aspects and syndromal associations of short trachea with bronchial intubation.

Conditions with disproportionately short trachea, with a reduced number of tracheal cartilage rings and a high level of tracheal bifurcation, have been reported. We have seen accidental bronchial intubation in nine patients with short trachea. This risk can be reduced by recognition of conditions associated with short trachea, by awareness that methods for calculating endotracheal tube length from body length can overpredict tube length for patients with short trachea, and when feasible, by use of preintubation chest roentgenograms showing air bronchograms to establish the thoracic level of tracheal bifurcation. Twelve patients with short trachea, four with bronchial intubation, and six conditions not previously associated with short trachea, are reported. Three of the patients also had laryngeal hypoplasia.

Short trachea, a hazard in tracheal intubation of neonates and infants: syndromal associations.

Short trachea results from reduction in number of tracheal cartilage rings to 15 or fewer from normal mean of 17 rings in infants. In a review of radiologic and pathologic data, the thoracic vertebral level of tracheal bifurcation as seen in anteroposterior chest radiographs of infants with congenital malformations, cardiovascular anomalies, and skeletal dysplasias, was compared with numbers of tracheal cartilage rings demonstrated in postmortem specimens. Increased frequency of short trachea was seen in patients with DiGeorge anomaly (77%), skeletal dysplasias (55%), brevicollis (57%), diaplacental rubella (40%), and patients with congenital heart disease who did not have DiGeorge anomaly (36%, with range 25-83% for different types, the highest, 83%, being interrupted aortic arch). Preintubation high kilovoltage chest radiographs to establish the level of tracheal bifurcation in patients with increased risk of short trachea can be helpful in avoiding bronchial intubation and its complications. Postintubation chest films to assure the level of the endotracheal tube tip should be considered for such patients. Growth in length of the trachea with age is accomplished both by increase in size of tracheal cartilage rings and interring membranes, and by increase in ring number.

Demonstration of myenteric plexus abnormalities in genetic diseases by a microdissection technique: preliminary studies.

Eighty-eight specimens of esophagus, small intestine, or colon from 45 patients, predominantly infants and children, with 30 different genetic diseases were analyzed by a microdissection technique for the following abnormalities of the Auerbach (myenteric) plexus: (1) abnormality of the pattern of the nervous network of the plexus, (2) abnormal fraction of neural tissue in the plane of the plexus, (3) abnormal size or appearance of the cytoplasm of the neurons of the plexus, and (4) abnormal number of neurons in the ganglia of the plexus. Seven of 8 specimens of esophagus from patients with neuronal storage diseases (infantile Niemann-Pick disease, Jansky-Bielschowsky disease, etc.) showed an increased fraction of neural tissue in the plane of the plexus, whereas 2 of 3 patients with Cockayne syndrome showed a reduced fraction, with abnormally slender interganglionic fibers. The fraction of neural tissue in the plane of the plexus was also abnormal at one or more levels in patients with adrenoleukodystrophy, ataxia telangiectasia, Krabbe disease, and juvenile metachromatic leukodystrophy. Abnormality of neuron size and cytology was seen in several neuronal lipidoses, including Jansky-Bielschowsky and Sandhoff diseases and juvenile GM2 gangliosidosis, with the most striking neuronal enlargement noted in infantile Niemann-Pick disease. Abnormalities of plexus mass or pattern, as well as those of neuronal cytoplasm and neuron number, offer improved insight into possible mechanisms producing gastrointestinal tract dysfunction (swallowing difficulty, gastroesophageal reflux, constipation, etc) in patients with genetic disorders.