Middle Cerebral Artery Stroke in a Neonate With a Congenital Hypercoagulable Condition Following Repair of an H-type Tracheoesophageal Fistula.

We report a case of middle cerebral artery stroke with heterozygosity for 2 separate hypercoagulable conditions following repair of an H-type tracheoesophageal fistula (TEF) in an infant. Neonatal stroke is rare, occurring in 1 in 4000 births annually in the United States. Stroke after pediatric surgery occurs in approximately 0.05% of patients. Etiologies of stroke in neonates include cardiac, hematologic, vascular, traumatic, metabolic, pharmacologic, infectious, and hypoxemic insults. Thrombophilia has been described in 42% to 78% of neonates with neonatal stroke. Stroke after repair of an H-type TEF has not been reported as a postoperative complication. Manipulation of the carotid artery during this operation is presumed to have contributed to a thromboembolic event in this infant with a hypercoagulable state. Whereas preoperative workup may not be indicated due to the low prevalence of neonatal stroke, workup for a congenital hypercoaguable condition may be considered in infants with stroke as a postoperative complication. This report provides a concise review of the etiology and treatment of stroke and hypercoagulable states in neonates as well as presents the case of a previously undescribed complication of repair of an H-type TEF.

Chemoselective amide formation using O-(4-nitrophenyl)hydroxylamines and pyruvic acid derivatives.

A series of O-(4-nitrophenyl)hydroxylamines were synthesized from their respective oximes using a pulsed addition of excess NaBH(3)CN at pH 3 in 65-75% yield. Steric hindrance near the oxime functional group played a key role in both the ease by which the oxime could be reduced and the subsequent reactivity of the respective hydroxylamine. Reaction of the respective hydroxylamines with pyruvic acid derivatives generated the desired amides in good yields. A comparison of phenethylamine systems bearing different leaving groups revealed significant differences in the rates of these systems and suggested that the leaving group ability of the N-OR substituent plays an important role in determining their reactivity with pyruvic acid. Competition experiments (in 68% DMSO/phosphate buffered saline) using 1 equiv of N-phenethyl-O-(4-nitrophenyl)hydroxylamine and 2 equiv of pyruvic acid in the presence of other nucleophiles such as glycine, cysteine, phenol, hexanoic acid, and lysine demonstrated that significant chemoselectivity is present in this reaction. The results suggest that this chemoselective reaction can occur in the presence of excess α-amino acids, phenols, acids, thiols, and amines.