Cerebrospinal nematodiasis caused by Parelaphostrongylus tenuis in Angora goats in Texas

A natural infection of meningeal worm (Parelaphostrongylus tenuis) accounted for the death of 11 of 17 (65%) Angora goats in a study in South Texas during 1975. Clinical signs, gross pathology and histopathology in Angoras were similar to other abnormal hosts.

Structural basis for aconitase activity inactivation by butanedione and binding of substrates and inhibitors

Aconitase (citrate(isocitrate)hydro-lyase, EC 4.2.1.3) prior to activation demonstrates a single binding site for substrates and inhibitors. On the basis of kinetic experiments, at pH 8.5 and 37 degrees C, with monomeric butanedione in borate, this binding site was found to contain a single arginine residue. Dissociation constants at pH 8.5 and 37 degrees C, determined from inhibitory effects on butanedione inactivation rates are: citrate, 0.74 mM; D-isocitrate, 0.33 mM: cis-aconitate, 0.52 mM; tricarballytate, 0.42 mM; trans-aconitate, 0.025 mM. Corresponding dissociation constants for the active enzyme are: tricarballylate, 0.39 mM; trans-aconitate, 0.14 mM. Active site Fe2+ added to the enzyme on activation is therefore not required for binding. Km values are: citrate, 0.23 mM and cis-aconitate 0.012 mM. Binding to active enzyme is considered to be transition state binding.

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.

A reappraisal of the role of splenectomy in children receiving renal allografts

Four renal allograft recipients between 8 and 14 years of age died of acute fulminating infections less than 72 hours after the onset of symptoms. These patients all had undergone splenectomy at the time of related donor renal transplantation. Because the therapeutic value of splenectomy in renal transplantation has not been established, the role of adjunctive splenectomy is evaluated, and the relationship between splenectomy and overwhelming infection is discussed. As a result of these acute deaths in 4 of 62 children undergoing renal transplantation at this institution (6.4%), splenectomy in conjunction with renal transplantation in children has been discontinued.

Gibberellic acid and the fine structure of barley aleurone cells : III. Vacuolation of the Aleurone cell during the phase of ribonuclease release

Ultrastructural changes in barley aleurone, cells treated with gibberellic acid (GA3) for 24-36 hr are described. Many large vacuoles are seen in the ground cytoplasm; the coalasce to form one large central vacuole. Evidence is presented indicating that the vacuoles are formed from the aleurone grains. The dictyosomes of aleurone cells treated with GA3 for 24 hr or longer proliferate many vesicles. This proliferation of dictyosome vesicles is associated with the phase of rapid ribonuclease release from the aleurone cell. Estimates indicate that microbodies are considerably reduced in number with GA3 treatment from 24-36, hr while the number of mitochondria is not substantially affected relative to controls. P-Protein-like material is seen in the cytoplasm of these cells often in close proximity to endoplasmic reticulum and spiny vesicles.