Solitary rectal ulcer: a rare cause of gastrointestinal bleeding in an adolescent with hemophilia A.

Solitary rectal ulcer syndrome (SRUS) is a rarely reported condition in children. The typical presentation is one of anorectal pain with passage of blood and mucus per rectum in the setting of defecation abnormalities. Diagnosis is made via endoscopy and biopsy. Solitary rectal ulcer syndrome alone is usually a benign condition; however, significant morbidity can occur if complicated by underlying disease states. We report an adolescent with hemophilia A and SRUS who presented with a rectal bleed that required blood transfusion.

Colonic chicken skin mucosa: association with juvenile polyps in children.

OBJECTIVES: Chicken skin mucosa is a newly described endoscopic finding associated with colonic neoplasms in adults. Chicken skin mucosa was sought in children with juvenile polyps to determine the prevalence, endoscopic features, and location. An alternative theory is proposed for the pathogenic mechanism of this finding. METHODS: Children having colonoscopy and polypectomy were prospectively evaluated for the presence of chicken skin mucosa. The location of the polyps was determined at colonoscopy; the size of removed polyps was measured during processing of samples in pathology. Biopsies from colonic chicken skin mucosa were stained with hematoxylin and eosin and mucicarmine. RESULTS: Over a 1-yr period, 27 juvenile polyps were removed from 15 children at colonoscopy. Eleven of 15 children (73%) were found to have polyps with chicken skin mucosa; overall, 43% of the polyps had associated chicken skin mucosa. Chicken skin mucosa-positive polyps were larger than chicken skin mucosa-negative polyps and were only found in the rectosigmoid colon. Lipid-laden macrophages were found in all samples of chicken skin mucosa tested. CONCLUSIONS: Chicken skin mucosa is a common finding in children with juvenile polyps. It probably is the result of local mucosal trauma, rather than a preneoplastic lesion.

Gastroesophageal reflux in children.

Gastroesophageal reflux (GER) is a common disorder in infants and children with a high rate of spontaneous resolution. Some children, however, will continue to have problems and progress from functional GER to pathogenic GER. In children with functional GER, diagnostic testing and pharmacologic treatment is unnecessary. In more involved cases, there are a number of tests available that help to quantify and qualify the extent of disease. Treatment begins with conservative measures and progresses to acid neutralization/supression and medications to enhance motility. Should medical management fail to control the consequences of reflux disease, surgical intervention is warranted.

Antiinflammatory effects of human milk on chemically induced colitis in rats.

We examined the effects of a human milk diet on rats with chemical colitis induced with a 4% acetic acid enema. Colonic myeloperoxidase activity was used as a surrogate marker for neutrophil infiltration. Control rats fed rat chow had little colonic myeloperoxidase activity; geometric mean, 0.27 U/g of tissue. Rats with colitis fed rat chow had significantly increased colonic myeloperoxidase activity (geometric mean, 6.76 U/g, p < 0.01 versus no colitis), as did rats with colitis fed infant formula or Pedialyte (geometric mean, 6.92 and 8.13 U/g, respectively, both p < 0.01 versus no colitis). Animals with colitis fed human milk had significantly lower colonic myeloperoxidase activity (geometric mean, 2.34 U/g) than did animals with colitis fed either chow or infant formula (p < 0.001). Similar effects were seen in rats with colitis fed infant formula supplemented with recombinant human IL-1 receptor antagonist (geometric mean, 1.95 U/g). These data show that orally administered human milk has an antiinflammatory effect on chemically induced colitis in rats, which may be mediated in part by IL-1 receptor antagonist contained in human milk.

Transforming growth factor alpha regulation of two zinc finger-containing immediate early response genes in intestine.

The epithelium lining the intestine undergoes rapid and continuous renewal. Growth factors play a role in intestinal epithelial growth regulation in vitro and in vivo. In this study, transforming growth factor alpha (TGF alpha) is shown to act as a mitogen and induce the expression of two zinc finger-containing immediate early genes [Zif268 (zinc finger protein 268) and Nup475 (nuclear protein 475)] in rat intestinal epithelial (RIE-1) cells in culture. These two gene products were initially isolated from serum-treated fibroblasts and represent growth-stimulated transcription factors. In TGF alpha-treated RIE-1 cells, nuclear run-on experiments demonstrate that TGF alpha induction of these two genes is regulated predominantly at the level of gene transcription. Utilizing in situ hybridization techniques, we show that systemic administration of TGF alpha induces expression of these two genes in the rat intestine. The predominant expression of zif268 is observed in the proliferative crypt compartment, whereas nup475 expression is concentrated in the postmitotic luminal compartment. These studies demonstrate that two immediate early genes, Nup475 and Zif268, are induced in intestinal epithelium in vitro and in vivo and thus may play a role in intestinal epithelial growth and/or differentiation.

Auto- and cross-induction within the mammalian epidermal growth factor-related peptide family.

Several polypeptide growth factors related to epidermal growth factor (EGF) have been identified recently, including transforming growth factor-alpha (TGF-alpha), amphiregulin (AR), heparin-binding EGF-like growth factor (HB-EGF), and betacellulin (BTC). These peptides all bind to the EGF receptor (EGFr). In an effort to understand redundancy within this peptide family and interactions among these related peptides, we compared the biological activities of EGF, TGF-alpha, AR, and HB-EGF in an EGF-responsive, nontransformed intestinal epithelial line (RIE-1) and also determined the effect of individual EGF-related peptides on the expression of related family members in these cells. TGF-alpha, AR, HB-EGF, and EGF were equipotent in stimulating [3H]thymidine incorporation by RIE-1 cells and bound the EGFr with equivalent affinity. Each EGF-related peptide induced the mRNA expression of the remaining family members, including BTC. HB-EGF and AR mRNAs were induced rapidly (within 30 min) and to a greater extent than TGF-alpha and BTC mRNAs, suggesting heterogeneity in the molecular mechanisms for induction. This same pattern was observed for all EGF-related peptides tested. A similar pattern of mRNA induction was observed in secondary cultures of human keratinocytes and in LIM1215 colon adenocarcinoma cells. Nuclear run-on analysis showed that induction of AR and HB-EGF is, at least in part, regulated at the level of gene transcription. Concurrent treatment with HB-EGF and cycloheximide resulted in superinduction of HB-EGF and AR, suggesting that these peptides are immediate early genes in RIE-1 cells. Our results demonstrate an equivalent biological response to EGF-related peptides in RIE-1 cells and further indicate that extensive auto-induction and cross-induction occur within the EGF-related peptide family in several EGF-responsive epithelial cell types.

Regulation of eicosanoid production and mitogenesis in rat intestinal epithelial cells by transforming growth factor-alpha and phorbol ester.

Growth factors and tumor promoters have been shown to play a role in intestinal epithelial growth regulation and transformation. In this study, transforming growth factor-alpha (TGF alpha) and the tumor promoter, tetradecanoyl phorbol acetate (TPA), are shown to stimulate the production of eicosanoids by rat intestinal epithelial (RIE-1) cells in culture. A 4.5-kb mRNA, which hybridizes to the mouse cyclooxygenase-2 cDNA probe, is elevated 18-fold within 30 min after TGF alpha or TPA treatment. Stimulation of RIE-1 cells with TGF alpha leads to the increase of a protein (M(r) approximately 69,000), which binds a monospecific antibody to the mouse cyclooxygenase-2 protein. Dexamethasone markedly inhibits the increase of the 4.5-kb mRNA. Pretreatment of TGF alpha or TPA-stimulated RIE-1 cells with dexamethasone or cyclooxygenase inhibitors prevents the increase in eicosanoid production by these cells. Treatment of quiescent RIE-1 cells with TGF alpha stimulates mitogenesis. This mitogenic activity is blocked by pretreating the cells with dexamethasone or cyclooxygenase inhibitors. A mitogen-inducible cyclooxygenase gene is thus shown to be regulated by TGF alpha and TPA in rat intestinal epithelial cells. We suggest that products of an intestinal growth factor-inducible cyclooxygenase may play a role in the regulation of mitogenesis.