Folding and oxidation of recombinant human granulocyte colony stimulating factor produced in Escherichia coli. Characterization of the disulfide-reduced intermediates and cysteine----serine analogs.

The folding and oxidation of recombinant human granulocyte colony-stimulating factor solubilized from Escherichia coli inclusion bodies was investigated. During the folding process, two intermediates, I1 and I2, were detected by kinetic studies using high performance liquid chromatography. I1 exists transiently and disappears quickly with the concomitant formation of I2. In contrast, I2 requires a longer time to fold into the final oxidized form, N. CuSO4 catalysis increases the folding rate of I2 from I1, while CuSO4 and elevated temperature (37 degrees C) have a dramatic effect on the folding rate of N from I2. These observations suggest the following sequential oxidative folding pathway. [sequence: see text] Peptide map analysis of the iodoacetate-labeled intermediates revealed that I1 represents the fully reduced granulocyte colony-stimulating factor containing 5 free cysteines; I2 is the partially oxidized species containing a single Cys36-Cys42 disulfide bond; and N, the final folded form, has two disulfide bonds. The physicochemical properties and biological activities of I1, I2, N, and several Cys----Ser analogs made by site-directed mutagenesis were further investigated. In guanidine hydrochloride-induced denaturation studies, the disulfide-reduced intermediates and the analogs missing either of the disulfide bonds are conformationally less stable than those of the wild type molecule or the analog with the free Cys at position 17 changed to Ser. Recombinant human granulocyte colony stimulating factor lacking either disulfide bond or both has overall secondary and tertiary structures different from those of the wild type molecule and exhibits lower biological activity. These studies show that disulfide bond formation is crucial for maintaining the molecule in a properly folded and biologically active form.

Single arterial trunk arising from the aortic arch. Evidence that the fifth branchial arch can persist as the definitive aortic arch.

A seven month old female having a single arterial trunk arising from the aortic arch is presented. The baby also had severe coarctation of the aorta and a patent ductus arteriosus. This anomaly cannot be explained by Edwards' embryonic double aortic arch model. However, it can be explained by persistence of the fifth branchial arch as the definitive aortic arch.

Cardiovascular effects of adolescent drug abuse.

Adolescent drug abuse has been shown to be highly prevalent. Similarly, chest pain is a frequent complaint among adolescents. The cardiovascular effects of adolescent drug abuse, however, are infrequently considered. We present a case report of a 17-year-old drug abuser who presented with a myocardial infarction. The potential cardiovascular complications of the commonly abused drugs are discussed. When dealing with an adolescent with potential cardiovascular symptoms, we stress an awareness of the potential cardiovascular effects of drug abuse and that such cardiovascular effects are not unique to the habitual or intravenous drug abuser.

Infantile polyarteritis nodosa with mucocutaneous lymph node syndrome treated with long-term corticosteroids.

Clinical and pathologic similarities between infantile polyarteritis nodosa (IPN) and mucocutaneous lymph node syndrome (MLNS, or Kawasaki disease) have suggested that these entities may be different manifestations of the same basic disease process. We have described a boy with IPN/MLNS treated with long-term corticosteroids for more than eight years after the appearance of multiple aneurysms at 11 months of age. Corticosteroid therapy may be appropriate in the treatment of selected patients with IPN/MLNS if based on age and the presence of aneurysms.

Total anomalous systemic venous return.

We have described an 18-year-old boy who is asymptomatic nine years after surgical correction of total anomalous systemic venous return. His clinical course and anatomy are compared to the eight previously reported patients.

"Dome and dart" P waves.

P waves with a "dome and dart" configuration have been observed in patients with congenital and acquired heart disease while having arrhythmias of left atrial origin. This report describes a patient who has dome and dart P waves that appear to be neither ectopic nor associated with structural heart disease.

Booster vaccination with further live attenuated measles vaccine.

Revaccination with live attenuated measles vaccine was evaluated in a large group of children to determine (1) if protective antibody to measles infection could be augmented and (2) after what interval will the revaccination yield optimal results. The rate of decline in measles hemagglutination-inhibition (HI) antibody was observed to be directly related to the time interval since the previous vaccination, and individuals with declining titers became increasingly responsive to revaccination with a maximal response approximately four to six years after previous vaccination. Six-month follow-up studies demonstrated sustained elevations in measles HI antibody titers. Measles-neutralizing antibody showed less tendency to sustain a titer increase with revaccination. The observations suggest that revaccination with live, further attenuated measles vaccine is safe and may augment immunity.