Dexter S.Y. Seto

Role of lower esophageal sphincter incompetence in recurrent pneumonia after repair of esophageal atresia

The etiology of recurrent aspiration pneumonitis after the successful repair of esophageal atresia has not been defined. In order to explain this occurrence, we performed esophageal manometric examinations on eight patients who had undergone repair of EA and tracheoesophageal fistula. Two patients who had had recurrent pneumonia had subnormal pressure of the lower esophageal sphincter; they also had a history of severe regurgitation, and a barium esophagram demonstrated free gastroesophageal reflux. The LES incompetence in these patients was apparently corrected by administration of bethanechol.

Interferon production and action in mouse, hamster and somatic hybrid mouse-hamster cells.

A hybrid mouse-hamster cell line was developed from a mouse cell line which produces a high titer of interferon and is sensitive to its action, and a hamster cell line which produces little interferon and is relatively insensitive to its action. Parental cell lines demonstrated complete species specificity with respect to interferon production and action. The hybrid cells produced interferon (or interferons) effective when tested on the mouse cell line and primary hamster cells; the hybrids were sensitive to the action of both mouse and hamster interferons. Hybrid cells produced ten times more hamster interferon than the parent hamster cell line and were eight times more sensitive to hamster interferon than the parent hamster cell line.

Hepatitis A and B

Viral hepatitis acquired after the neonatal period has been of two types, distinguished generally by their different incubation periods. Now better designated hepatitis A and hepatitis B, the history, clinical picture, differential diagnosis, and therapy of these disorders are discussed.

Conjunctivitis and Keratoconjunctivitis Associated with Primary Immunodeficiency Diseases

Nineteen patients with a variety of well-defined primary immunodeficiency diseases were examined for ocular abnormalities. Eight patients with low levels, or absence, of all the major serum immunoglobulins had conjunctivitis or keratoconjunctivitis associated with bacterial infection. The remaining 11 patients, who had at least one immunoglobulin class present in normal concentration in the serum, showed no inflammatory ocular lesion. Absence of only IgA, the major tear immunoglobulin, did not predispose the eye to these lesions.

Circulating Interferon in Sudden Infant Death Syndrome

Summary Circulating interferon, which may be indirect evidence of viral infections, was searched for in the Sudden Infant Death Syndrome (SIDS). A viral inhibitor with the properties of inteferon was detected in the serum of three out of 44 cases of SIDS, and in one out of 22 control cases. These results show that circulating interferon is not frequently detected in SIDS, and suggest that if viruses do play a role in the final common pathway of SIDS, they may possibly function in a local manner, rather than in a disseminated type of infection.

Acute Respiratory Infections

The radiographic and clinical features of a variety of pneumonias provide helpful clues in the diagnosis and therapy of these infections which, although they are relatively rare, constitute a potential serious problem because of the complications that may develop.

The Effect of Cell Density on the Production of Interferon

Summary L-929 cells growing under different conditions of spinner and monolayer cultures were compared according to cell counts, NDV replication, interferon production, and incorporation of radioactive precursors. With equal numbers of cells and NDV replication, the monolayer culture produced 4-32-fold more interferon than that from the respective spinner culture. The spinner and monolayer cultures were also different regarding their metabolic activity as measured by the incorporation of 3H-thymidine and 14C-leucine. DNA and protein synthesis were increased in the spinner culture in contrast to the minimal activity of the monolayer culture. The data shows that the monolayer culture possessed a larger capacity for the induction of interferon than that of the spinner culture, which provides further evidence that the density of cells and their metabolic state influence their production of interferon. We thank Mrs. Jean Simkins and Miss Kathy Lambdin for excellent technical assistance, and Dr. David H. Carver for critical suggestions.