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.

Continental breakup and the ordinal diversification of birds and mammals.

The classical hypothesis for the diversification of birds and mammals proposes that most of the orders diverged rapidly in adaptive radiations after the Cretaceous/Tertiary (K/T) extinction event 65 million years ago. Evidence is provided by the near-absence of fossils representing modern orders before the K/T boundary. However, fossil-based estimates of divergence time are known to be conservative because of sampling biases, and some molecular/time estimates point to earlier divergences among orders. In an attempt to resolve this controversy, we have estimated times of divergence among avian and mammalian orders with a comprehensive set of genes that exhibit a constant rate of substitution. Here we report molecular estimates of divergence times that average about 50-90% earlier than those predicted by the classical hypothesis, and show that the timing of these divergences coincides with the Mesozoic fragmentation of emergent land areas. This suggests that continental breakup may have been an important mechanism in the ordinal diversification of birds and mammals.

Rapid ethanol elimination in patients with type I glycogen storage disease is an adaptive change resulting from recurrent hypoglycemia.

Patients with deficient activity of hepatic glucose-6-phosphatase (glycogen storage disease type I [GSD-I]) have fasting-induced hypoglycemia, lactic acidemia, hyperuricemia, hyperlipidemia, and a markedly increased capacity for ethanol elimination. The mechanism(s) responsible for the rapid ethanol elimination is not known but has been thought to be directly related to the enzyme defect. We postulated however, that the increased elimination of ethanol was an adaptive phenomenon that would revert toward normal with correction of other blood abnormalities by long-term maintenance of normal blood glucose concentration. Six patients were observed before treatment (group A), and four of the six were observed again 3 to 6 months after dietary treatment had normalized all blood abnormalities (group B). Patients received 16 ml/m2 absolute ethanol as a 5% solution in 0.9% sodium chloride over a 20-minute period. The rate of ethanol elimination was significantly greater (P less than 0.03) in group A than in group B (55.1 +/- 11.1 vs. 37.5 +/- 8.6 mg/dl/hr). Changes in lactate level after ethanol were also significant between the two groups (P less than 0.005). Group A showed a decrease from 9.4 +/- 0.5 to 6.4 +/- 0.4 mEq/L, whereas group B showed an increase in lactate level from 2.7 +/- 0.2 to 4.4 +/- 0.64 mEq/L. Ethanol induced no significant change in blood glucose concentration in group A, whereas there was a significant increase (P less than 0.03) in group B from 93 +/- 6 to 123 +/- 9 mg/dl.(ABSTRACT TRUNCATED AT 250 WORDS)

Intestinal maturation: effect of luminal osmolality on net mineral secretion.

We investigated with an in vivo single-pass perfusion technique net secretion of calcium, magnesium, and zinc from proximal and distal small intestinal segments and from the cecum plus colon segments of suckling, weanling, and adolescent rats during perfusion with either isotonic (300 mOsm/kg) or hypertonic (500 mOsm/kg) mineral-free solutions. There was not secretion of calcium, magnesium, and zinc in all segments perfused at all age periods. During isotonic perfusion, rates of net secretion of calcium and zinc were severalfold greater in the proximal and distal segments of the suckling rats compared with the corresponding segments of the adolescent rats. Net magnesium secretion was similar in the sucking and adolescent rats. Net secretion rates for the weanling rats tended to be intermediate. During hypertonic perfusion, net secretion rates for calcium, magnesium, and zinc were severalfold greater from all segments of the suckling rats compared with the corresponding segments of the adolescent rats. During either isotonic or hypertonic perfusions, rates of net secretion of calcium and magnesium in general were greater from the proximal and distal segments than from the cecum plus colon in the suckling and weanling rats. In contrast, for the adolescent rats, net secretions from all segments in general were similar. For zinc, rates of net secretion were somewhat greater in the cecum plus colon of rats in all age groups. Our findings suggest a greater permeability of the intestinal epithelium, not only to water and electrolytes but also to certain minerals (calcium and magnesium) and trace elements (Zn) in suckling rats compared with adolescent rats. The implication is that during periods of osmotic diarrhea, infant animals appear to be at risk for losing excessive amounts of minerals and trace elements. These findings may have clinical relevance to human infants suffering from recurrent diarrheal diseases.

Recurrent pancreatitis induced by valproic acid. A case report and review of the literature.

Valproic acid represents a new class of anticonvulsants that are widely employed in the management of many types of seizure disorders. Compared with other anticonvulsants, it has been considered relatively free of adverse effects. Recently, acute hepatic failure has been ascribed to valproic acid. Now experience is accumulating that implicates this agent in causing pancreatitis. Contributing to this evidence, the patient described herein had well-documented, recurrent pancreatitis while he was taking valproic acid. Nonspecific vomiting and abdominal pain frequently occur with valproic acid; however, pancreatitis must be considered whenever these symptoms are severe or protracted.