Meconium obstruction of prematurity is a distinct clinical condition that occurs in very low birth weight infants, predisposing them to intestinal perforation and a prolonged hospitalization if not diagnosed and treated promptly. We report a series of 21 infants, including 2 detailed case reports, whose clinical course is indicative of meconium obstruction of prematurity. Specific risk factors are identified along with descriptions of clinical and radiologic findings, disease course, treatment, and outcome. Meconium obstruction of prematurity was more common in infants with a maternal history of pregnancy-induced or chronic hypertension, suggesting the possibility of decreased intestinal perfusion prenatally. Inspissated meconium was located most frequently in the distal ileum, making this disease process difficult to treat. Gastrografin enemas were safe, diagnostic, and therapeutic. Delay in diagnosis and treatment was associated with perforation and delay in institution of enteral feeds.

BACKGROUND. Spontaneous intestinal perforation of the extremely low birth weight infant (Յ1000 g) is associated with a high incidence of Candida and coagulasenegative Staphylococcus sepsis. Little is known about prenatal risk factors, and histopathologic examination of placentas in infants with spontaneous intestinal perforation has not been reported.

Holder pasteurization greatly decreased concentrations of EPO and IL-10 in human milk. These decreases may impact the ability of human milk to protect against necrotizing enterocolitis. Evidence of possible binding of IL-10 to other proteins in human milk was also found. Experiments to test whether Holder pasteurization affects the function of IL-10 in human milk produced evidence for an agent in human milk other than IL-10 that inhibits T-cell proliferation and resists Holder pasteurization.

Human milk neutrophils and macrophages were examined by flow cytometry to determine whether they displayed phenotypic markers of activation. The markers were CD11b and L-selectin, which are increased or shed, respectively, from the surface of activated neutrophils. Phenotypic features of milk neutrophils and macrophages were similar to blood neutrophils stimulated with fMLP: plasma membrane expression of CD11b was increased and L-selectin was decreased. After blood neutrophils were incubated in acellular milk, their expression of CD11b increased and L-selectin decreased. The activation was not affected by trypsin but was significantly decreased by treating acellular milk with chloroform or ether. Sedimentation studies suggested that particulate fractions of milk were active. Further, the activation was partly blocked by treating target blood neutrophils with cytochalasin B. Thus, human milk neutrophils are activated, and the activation may be due partly to phagocytosis of membranous structures in milk.

Significantly more animals survived AVCO2R than LTV. In experiment 2, Lung MPO was significantly lower for AVCO2R, compared with LTV (P < 0.05). This finding taken together with the TUNEL and neutrophil apoptosis results, suggested that disposition of neutrophils 72 hours post-ARDS criteria was different among the ventilatory strategies with neutrophils from AVCO2R-treated animals removed chiefly through apoptosis, but in the cases of HFPV and LTV, dying by necrosis in lung tissue.