Where Did the Blood Go?: A Meckel's Diverticulum Bleed Without Hematochezia or Melena.

A 2-year-old patient with chronic abdominal pain presented with acutely worsening abdominal pain and acute anemia. The patient had no stigmata of bleeding including no hematemesis, melena or hematochezia, but had falling hemoglobin and hematocrit over the course of 24 hours. Abdominal ultrasound and computerized tomography showed a large cystic, fluid filled mass in the right midabdomen.

Pediatric Collagenous Gastritis: Clinical and Histologic Outcomes in a Large Pediatric Cohort.

Objective: The aim of the study was to present the clinical characteristics, treatment, and outcomes of pediatric collagenous gastritis (CG).

Method: This is a retrospective cohort study. Patients were identified via query of the institutional pathology database.

Pediatric Collagenous Gastroenterocolitis Successfully Treated with Methotrexate.

A two-and-one-half-year-old previously healthy female presented with a ten-week history of watery diarrhea, nonbilious and nonbloody emesis, and low-grade fevers. She was found to have severe hypoalbuminemia and hypogammaglobulinemia. Her symptoms persisted, and she became dependent on parenteral nutrition.

Fatal Central Nervous System Disease Following First Infliximab Infusion in a Child With Inflammatory Bowel Disease.

Background: Infliximab is used in the treatment of inflammatory bowel disease. Previously reported neurological complications include central and peripheral demyelinating disorders and neuropathies occurring months into therapy.

Patient Description: A seven-year-old boy diagnosed with ulcerative colitis and primary sclerosing cholangitis received infliximab.

Risk factors, morbidity, and treatment of thrombosis in children and young adults with active inflammatory bowel disease.

Objectives: Pediatric inpatients with inflammatory bowel disease (IBD) are rarely considered for thromboprophylaxis because of concerns about safety and underappreciation of thrombotic risk. We characterized thromboembolism (TE) in children and young adults with inflammatory bowel disease (IBD) at a single tertiary care hospital.

Methods: We performed a retrospective review of an inpatient billing database for all IBD admissions with colonic involvement and an anticoagulation database for thrombotic complications from 2006 to 2011.

Thrombosis and inflammatory bowel disease: a call for improved awareness and prevention.

Thrombotic complications in patients with inflammatory bowel disease (IBD) are common and require improved awareness and prevention. In this review the interface between IBD and thrombosis is discussed, with emphasis on risk assessment and data to aid clinical decision making. Thromboembolic complications are 3-fold more likely in IBD patients than controls and the relative risk exceeds 15 during disease flares.

Regulatory regions in the rat lactase-phlorizin hydrolase gene that control cell-specific expression.

Objectives: Lactase-phlorizin hydrolase (LPH) is an enterocyte-specific gene whose expression has been well-characterized, not only developmentally but also along the crypt-villus axis and along the length of the small bowel. Previous studies from the authors' laboratory have demonstrated that 2 kb of the 5'-flanking region of the rat LPH gene control the correct tissue, cell, and crypt-villus expression in transgenic animals.

Methods: To examine further the regulation conferred by this region, protein-DNA interactions were studied using DNase I footprint analyses in LPH-expressing and nonexpressing cell lines.

Three distinct messenger RNA distribution patterns in human jejunal enterocytes.

Background & Aims: The importance of messenger RNA (mRNA) localization in human enterocytes is poorly understood. Previous studies from our laboratory have indicated that mRNAs are asymmetrically distributed in human intestinal epithelial cells, but in general colocalized with their encoded proteins. The aim of this study was to characterize, in human enterocytes, mRNA localization patterns of three genes with distinctly different functions.

Asymmetrical localization of mRNAs in enterocytes of human jejunum.

Intracellular localization of specific mRNAs is known to be a mechanism for targeting proteins to specific sites within the cell. Previous studies from this laboratory have demonstrated co-localization of mRNAs and proteins for a number of genes in absorptive enterocytes of fetal rat intestine. The present study was undertaken to examine in human enterocytes the intracellular localization patterns of mRNAs for the microvillous membrane proteins lactase-phlorizin hydrolase (LPH), sucrase-isomaltase (SI), and intestinal alkaline phosphatase (IAP), and the cytoskeletal protein beta-actin.

Rat lactase-phlorizin hydrolase/human growth hormone transgene is expressed on small intestinal villi in transgenic mice.

Background & Aims: Lactase-phlorizin hydrolase (LPH) is an absorptive enterocyte-specific gene that is expressed in a well-characterized pattern along the cryptvillus (vertical), proximal-distal (horizontal), and developmental (temporal) gradients. The aim of this study was to characterize the capacity of regulatory elements within the rat LPH gene to direct appropriate cell lineage and topographical patterns of expression in vivo in transgenic mice.

Methods: Transgenic mouse lines were established using a construction containing bases -2038 to +15 of the rat LPH gene fused to a human growth hormone reporter gene.

Combined use of cyclosporine and azathioprine or 6-mercaptopurine in pediatric inflammatory bowel disease.

The aim of this study was to assess whether in steroid-resistant patients with pediatric inflammatory bowel disease (IBD) a combination of cyclosporine and azathioprine (or 6-mercaptopurine) could induce remission and subsequently permit maintenance on azathioprine/6-mercaptopurine as the sole immunosuppressive agent. Two boys and six girls (six with ulcerative colitis and two with Crohn's disease; ages 3-17 years) received 100-200 micrograms/kg/day cyclosporine intravenously and then 4-10 mg/kg/day orally. Doses were adjusted to achieve trough serum cyclosporine levels of 100-200 mu/L (Abbott's TDX assay).

Verification of the lactase site of rat lactase-phlorizin hydrolase by site-directed mutagenesis.

Background & Aims: Lactase-phlorizin hydrolase (LPH) is an intestinal microvillus membrane glycoprotein that hydrolyzes lactose and phlorizin. These enzymatic activities have been assigned to glutamic acid (E) residues 1271 and 1747 in rabbit LPH. The aim of this study was to determine directly if this assignment was correct and if these two amino acids are the only nucleophiles required for LPH enzyme activity.

Further characterization of the 5'-flanking region of the rat lactase-phlorizin hydrolase gene.

The lactase-phlorizin hydrolase gene is widely used as a marker of intestinal differentiation. Recent evidence demonstrating that transcription plays a major role in the regulation of this gene suggests that study of the 5'-flanking region will allow an understanding of how the expression of this gene is controlled. However, sequence, restriction, and primer extension analysis of a rat genomic clone has revealed that previously published data are incomplete.

Transcriptional regulation of intestinal hydrolase biosynthesis during postnatal development in rats.

Lactase-phlorizin hydrolase (LPH) and sucrase-isomaltase (SI) are intestine-specific microvillus membrane hydrolases whose specific activities demonstrate reciprocal regulation during development but whose mechanisms of regulation have not been fully defined. To investigate transcriptional control of these two proteins, the rat LPH and SI genes were cloned, and antisense probes for preprocessed mRNAs (pre-mRNAs) were developed from intron sequence. LPH mRNA, as measured by quantitative ribonuclease (RNase) protection assays, was abundant before weaning and decreased two- to fourfold during weaning, whereas SI mRNA was first detected 14 days after birth and increased rapidly to abundant levels by age 28 days.

Identification of nonsteroidal antiinflammatory drug-induced gastroduodenal injury in children with juvenile rheumatoid arthritis.

In a cohort of children with juvenile rheumatoid arthritis treated with nonsteroidal antiinflammatory drugs and referred for gastrointestinal complaints, more than 75% had gastritis, antral erosions, or ulcers. Epigastric pain strongly correlated with documented gastroduodenal injury. Therapy with ranitidine or misoprostol led to clinical improvement.

Cyclic AMP- and phorbol ester-induced transcriptional activation are mediated by the same enhancer element in the human vasoactive intestinal peptide gene.

Transcription of the human vasoactive intestinal peptide (VIP) gene is regulated by both cyclic AMP and phorbol esters. A 17-nucleotide enhancer element within the human VIP gene mediates transcriptional activation by both phorbol esters and forskolin. Mutations of this element decrease responses to both agents, suggesting that the trans-acting proteins that mediate both modes of transcriptional regulation have similar DNA-binding characteristics.

Azathioprine in the treatment of children with inflammatory bowel disease.

During a 6-year period, we treated 21 patients with azathioprine, 2 mg/kg/day, as an adjunct to their customary regimen. Nine patients had ulcerative colitis and 12 patients had Crohn disease; the patients' ages ranged from 3 to 17 years. The median duration of disease before the start of azathioprine therapy was 2 years, and median follow-up was 2 years.

Somatostatin gene regulation: an overview.

The somatostatinergic system has proven to be one of the best models of neuropeptide biology. Originally characterized as a hypothalamic regulator of growth hormone secretion, somatostatin also regulates the secretion of several other pituitary, pancreatic, and gastrointestinal (GI) hormones including thyrotropin-stimulating hormone, insulin, glucagon, and gastrin. Disorders in somatostatin metabolism have been proposed to contribute to the pathogenesis of Alzheimer's disease, epilepsy, GI motility disorders, and diabetes.

The CGTCA sequence motif is essential for biological activity of the vasoactive intestinal peptide gene cAMP-regulated enhancer.

cAMP-regulated transcription of the human vasoactive intestinal peptide gene is dependent upon a 17-base-pair DNA element located 70 base pairs upstream from the transcriptional initiation site. This element is similar to sequences in other genes known to be regulated by cAMP and to sequences in several viral enhancers. We have demonstrated that the vasoactive intestinal peptide regulatory element is an enhancer that depends upon the integrity of two CGTCA sequence motifs for biological activity.

An evaluation of two antigen nonspecific assays for circulating immune complexes using a model system.

Two methods of detecting circulating immune complexes (CIC) in serum, the Protein A-glass fiber filter assay (PA-GFF) and the polyethylene glycol (PEG) insolubilization assay, were compared using a model system of BSA/anti-BSA. Supernatants of the quantitative precipitin curve from extreme antigen excess through antibody excess were tested by both methods. The PEG assay detected soluble CIC in all areas where expected by comparison with the Farr Test; the filter assay did not, although it did detect aggregated globulins quantitatively.