Validation of the Rome III criteria and alarm symptoms for recurrent abdominal pain in children.

OBJECTIVES: Rome criteria were formulated to define functional gastrointestinal disorders (Rome III criteria, 2006) excluding organic diagnoses when alarm symptoms were absent. The aims of the study were to validate the Rome III criteria as to their capacity to differentiate between organic and functional abdominal pain and to assess the role of alarm symptoms in this differentiation. METHODS: During 2 years all of the patients (ages 4-16 years) presenting with recurrent abdominal pain (Apley criteria) and referred to secondary care were included. Clinical diagnoses were based on protocolized evaluation and intervention with 6-month follow-up. Alarm symptoms were registered. Rome III criteria for functional pain syndromes were assigned independently. Descriptive statistical analyses were performed. RESULTS: In 200 patients (87 boys, mean age 8.8 years), organic (17%), functional (40%), combined organic and functional (9%), spontaneous recovery (27%), and other (8%) clinical diagnoses were established. Alarm symptoms were found in 57.5% (organic causes 56%, functional causes 61%). The evaluation for Rome symptom clusters revealed symptoms of irritable bowel syndrome in 27%, functional dyspepsia in 15%, functional abdominal pain in 28%, functional abdominal pain syndrome in 14.5%, and no pain syndrome in 15.5%. Rome diagnoses, based on symptoms and absence of alarm symptoms, predicted functional clinical diagnosis with sensitivity 0.35 (95% confidence interval 0.27-0.43), specificity 0.60 (0.46-0.73), positive predictive value 0.71 (0.61-0.82), and negative predictive value of 0.24 (0.17-0.32). CONCLUSIONS: The Rome III criteria for abdominal pain are not specific enough to rule out organic causes. Alarm symptoms do not differentiate between organic and functional abdominal pain.

Occult constipation: faecal retention as a cause of recurrent abdominal pain in children.

UNLABELLED: Recurrent abdominal pain (RAP) in children is generally believed to be functional. In practice, many children with RAP become pain-free with laxative therapy. The aims of the study were to establish the role of (occult) constipation in RAP and to investigate whether patients diagnosed with (occult) constipation could be identified by history and physical examination. During 2 years, all patients (age 4-16 years, secondary referral) fulfilling Apley criteria of RAP were included. After exclusion of gastrointestinal infections and food intolerance, laxatives were advised when pain persisted. (Occult) constipation was defined as 'abdominal pain disappearing with laxative treatment and not reappearing within a 6 month follow up period'; 'occult constipation' was diagnosed in patients who did not fulfil the Rome criteria of constipation. Two hundred children (87 M; median age 8.8 years) were evaluated. (Occult) constipation was found in 92 patients (46 %). Of these, 18 had considerable relief of pain when treated for a somatic cause but experienced complete relief only after laxative measures; they were considered to have two diagnoses. Using multivariate analysis, a simple model was developed with cystitis in past history, early satiety and flatulence as predictors for (occult) constipation. The risk of (occult) constipation ranged from 18/58 if no predictor was present to 4/4 if all three were present. CONCLUSION: Laxatives played a pivotal role in the recovery of patients with RAP. We developed a simple model to identify patients at risk of having (occult) constipation.

Protozoa as a cause of recurrent abdominal pain in children.

OBJECTIVES: The aim of this study was to investigate whether protozoa can be identified as a cause of recurrent abdominal pain (RAP), and whether protozoan infections can be recognized by a specific clinical presentation. METHODS: For 2 years, all patients (ages 4-16 years) fulfilling the Apley criteria of RAP referred to secondary care were prospectively evaluated for protozoa (Giardia lamblia, Dientamoeba fragilis, Blastocystis hominis) and treated if positive. Re-examination followed at least 10 days after treatment. Disappearance of pain with eradication and a pain-free follow-up of at least 6 months were considered to be indicative of a causal relation with RAP. The predictive value of the characteristics of the pain for protozoan infections was calculated. RESULTS: Of 220 included patients (92 boys, mean age 8.8 years), 215 brought a stool sample; 73 (34%) carried parasites, 10 of whom had 2 parasites, 2 had 3 parasites. Sixty-five patients were treated. Twenty-five (11%) were pain-free after eradication (21 had D fragilis, 8 B hominis, 4 G lamblia), of whom 11 had another infection (2) or constipation (9) as second diagnosis for the pain. Five had recurrence of infection with D fragilis and were again pain-free with eradication. Patients with protozoa as cause of their pain did not show differences with respect to their presentation when compared with patients with an asymptomatic infection and patients without protozoa. CONCLUSIONS: Protozoa were found as the cause of pain in 6% to 11% of children with RAP. These patients did not show a characteristic presentation when compared with patients with other causes of abdominal pain.

Translation of rare disease research into orphan drug development: disease matters.

More than 25 years of orphan drug regulations have yielded several new treatments for patients with rare diseases. Here, we show that successful translation of rare disease research into an orphan drug discovery and development programme is dependent on the disease class, its prevalence and the disease-specific scientific output. Our findings indicate that current orphan drug legislation alone is not sufficient to stimulate orphan drug development for diseases with a very low prevalence. Consequently, additional incentives should focus on stimulating the specific needs of rare disease research at disease class level.

Orphan drug development across Europe: bottlenecks and opportunities.

With the assignment of the 500th European Union orphan drug designation in 2007, the Regulation on Orphan Medicinal Products truly begins to show its potential for delivering new medicines to patients with rare diseases. Here, we analysed European orphan drug development at a national level and unveil a strong relationship between orphan drug development and pharmaceutical innovation performance in Europe. Moreover, we identify gaps in transition from science into orphan drug development as important bottlenecks that exist in several European countries. Our findings underline the importance of innovation-based policies to enhance the development of orphan drugs in Europe.

Combined defects in epithelial and immunoregulatory factors exacerbate the pathogenesis of inflammation: mucin 2-interleukin 10-deficient mice.

Expression of the mucin MUC2, the structural component of the colonic mucus layer, is lowered in ulcerative colitis. Furthermore, interleukin (IL)-10 knockout (IL-10-/-) mice develop colitis and have reduced Muc2 levels. Our aim was to obtain insight into the role of Muc2 and IL-10 in epithelial protection. Muc2-IL-10 double-knockout (Muc2/IL-10(DKO)) mice were characterized and compared to Muc2 knockout (Muc2-/-), IL-10-/- and wild-type (WT) mice. Clinical symptoms, intestinal morphology and differences in epithelial-specific protein levels were analyzed. In addition, levels of the pro-inflammatory cytokines in colonic tissue and serum were determined. IL-10-/- mice were indistinguishable from WT mice throughout this experiment and showed no clinical or histological signs of colitis. Muc2/IL-10(DKO) and Muc2-/- mice showed significant growth retardation and clinical signs of colitis at 4 and 5 weeks, respectively. Muc2/IL-10(DKO) mice had a high mortality rate (50% survival/5 weeks) compared to the other types of mice (100% survival). Microscopic analysis of the colon of Muc2/IL-10(DKO) mice showed mucosal thickening, increased proliferation, superficial erosions and a diminished Muc4 expression. Furthermore, pro-inflammatory cytokines were significantly upregulated, both in tissue (mRNA) and systemically in Muc2/IL-10(DKO) mice. In conclusion, Muc2/IL-10(DKO) mice develop colitis, which is more severe in every aspect compared to Muc2-/- and IL-10-/- mice. These data indicate that (i) in case of Muc2 deficiency, the anti-inflammatory cytokine IL-10 can control epithelial damage, though to a limited extent and (ii) the mucus layer is most likely a key factor determining colitis.

20 years of scientific training of Dutch medical students in an American academic division for pediatric gastroenterology and nutrition: impact on career development.

OBJECTIVES: To evaluate the impact on career development of a program for scientific training of Dutch medical students in an American academic division for pediatric gastroenterology and nutrition. MATERIALS AND METHODS: A survey was undertaken of medical students who were trained in the division of pediatric gastroenterology and nutrition at Tufts University and later at Children's Hospital, Harvard Medical School, Boston, MA. Characteristics of the students, the training period, the scientific output, and their career development were evaluated. RESULTS: A questionnaire was sent to 54 students, of which 39 (72%) responded. The mean time of their rotation was 12.2 +/- 12.1 months. Twenty-five students published 33 scientific manuscripts. Fifteen students obtained a doctorate degree and 4 are involved in a doctorate program. Six theses were directly related to the scientific content of the rotation and were performed under the supervision of American mentors. A total of 59% of the students hold a position as medical specialist, which is a substantially higher percentage than the national average of all graduated medical doctors. Thirty-five percent of them practice pediatrics (of whom 38% practice pediatric gastroenterology) and 22% practice gastroenterology. Seventy-eight percent of the medical specialists hold an academic position. CONCLUSIONS: Dutch medical students who are scientifically trained in a US academic division for pediatric gastroenterology and nutrition--where specialists approached all of the students with a special program to involve them in biomedical research--have a great chance to establish a scientific career track and to become a medical specialist.

Predictors of orphan drug approval in the European Union.

OBJECTIVE: To encourage the development of drugs for rare diseases, orphan drug legislation has been introduced in the USA (1983) and in the EU (2000). Recent literature discusses factors that may influence the development of new orphan medicinal products in the EU. This study aims to identify predictors for successful marketing authorisation of potential orphan drugs in the EU. METHODS: A comparison between randomly selected authorised and a matched sample of not-yet-authorised orphan drug designations has been performed. Determinants in the study included characteristics of the indication, of the product and of the sponsor. Data were collected from the public domain only. RESULTS: Orphan drug approval was strongly associated with previous experience of the sponsor in obtaining approval for another orphan drug (OR = 17.3, 95% CI = 5.6-53.1). Furthermore, existing synthetic entities compared to biotechnology products tended to have a higher likelihood of reaching approval status (OR = 3.9, 95% CI = 0.9-16.6). CONCLUSION: This study showed that experience of a company in developing orphan drugs is an important predictor for subsequent authorisation of other orphan drugs. The same applies for existing (synthetic) molecules, for which much knowledge is available. Further research should be directed towards studying the quality of the clinical development program of those designated orphan medicinal products not reaching approval status.

Cyclooxygenase activity is important for efficient replication of mouse hepatitis virus at an early stage of infection.

Cyclooxygenases (COXs) play a significant role in many different viral infections with respect to replication and pathogenesis. Here we investigated the role of COXs in the mouse hepatitis coronavirus (MHV) infection cycle. Blocking COX activity by different inhibitors or by RNA interference affected MHV infection in different cells. The COX inhibitors reduced MHV infection at a post-binding step, but early in the replication cycle. Both viral RNA and viral protein synthesis were affected with subsequent loss of progeny virus production. Thus, COX activity appears to be required for efficient MHV replication, providing a potential target for anti-coronaviral therapy.

Alterations in epithelial and mesenchymal intestinal gene expression during doxorubicin-induced mucositis in mice.

In the current study we aimed to gain insight into epithelial-mesenchymal cross-talk and progenitor compartment modulation during doxorubicin (DOX)-induced mucositis in mice. Intestinal segments were collected on various days after DOX treatment. DOX-induced damage at day 1-2 was characterized by increased epithelial proliferation and apoptosis and a decrease in the expression of epithelial differentiation markers. Concurrently, T-cell factor-4 (TCF4) levels increased and the epithelial differentiation enhancing factor, bone morphogenic protein-4 (BMP4), decreased. During severe damage (day 3), BMP4 levels were significantly increased, which inversely correlated with epithelial proliferation. At the same time, the expression of the epithelial differentiation markers was increasing again. At day 7, BMP4 levels were down-regulated, while the levels of the epithelial differentiation markers and TCF4 were normalized again. These data suggest that in response to DOX-induced damage, BMP4 and TCF4 are modulated in such a way that homeostasis of the progenitor compartment is partly preserved.

Methotrexate-induced mucositis in mucin 2-deficient mice.

The mucin Muc2 or Mycin2 (Muc2), which is the main structural component of the protective mucus layer, has shown to be upregulated during chemotherapy-induced mucositis. As Muc2 has shown to have protective capacities, upregulation of Muc2 may be a counter reaction of the intestine protecting against mucositis. Therefore, increasing Muc2 protein levels could be a therapeutic target in mucositis prevention or reduction. Our aim was to determine the role of Muc2 in chemotherapy-induced mucositis. Mucositis was induced in Muc2 knockout (Muc2(-/-)) and wild type (Muc2(+/+)) mice by injecting methotrexate (MTX). Animals were weighed and sacrificed on Days 2-6 after MTX treatment and jejunal segments were analyzed. Before MTX treatment, the small intestine of Muc2(+/+) and Muc2(-/-) mice were similar with respect to epithelial morphology and proliferation. Moreover, sucrase-isomaltase and trefoil factor-3 protein expression levels were comparable between Muc2(+/+) and Muc2(-/-) mice. Up to Day 3 after MTX treatment, percentages of weight-loss did not differ. Thereafter, Muc2(+/+) mice showed a trend towards regaining weight, whereas Muc2(-/-) mice continued to lose weight. Surprisingly, MTX-induced intestinal damage of Muc2(-/-) and Muc2(+/+) mice was comparable. Prior to MTX-injection, tumor necrosis factor-alpha and interleukin-10 mRNAs were upregulated in Muc2(-/-) mice, probably due to continuous exposure of the intestine to luminal antigens. Muc2 deficiency does not lead to an increase in chemotherapy-induced mucositis. A possible explanation is the mechanism by which Muc2 deficiency may trigger the immune system to release interleukin-10, an anti-inflammatory cytokine before MTX-treatment.

Protection against chemotherapy induced mucositis by TGF-beta(2) in childhood cancer patients: results from a randomized cross-over study.

BACKGROUND: Mucositis is one of the most frequent and severe side-effect of chemotherapy in childhood-cancer patients for which there is no prophylaxis available. The efficacy and feasibility of a TGF-beta(2)-enriched feeding for preventing oral and gastro-intestinal-mucositis in childhood-cancer patients were studied. PROCEDURE: The study was designed as a two-period cross-over, randomized, double-blinded, placebo, controlled trial. Patients who had a high risk for developing mucositis and who would receive two comparable cycles of chemotherapy were eligible for the study. During one cycle of chemotherapy, TGF-beta(2)-enriched feeding was administered; during the other, a "placebo" (not enriched) feeding was used. WHO toxicity scales of diarrhea, oral mucositis, fever, anal lesions and nausea/vomiting were scored daily. In addition, the incidence of occurrence of blood cultures, antibiotic therapy, and interventions or diagnostics related to mucositis were measured. RESULTS: The feasibility of the study was good: 83% of the patients completed two cycles and 86% of the study-feeding was effectively consumed. Administration of TGF-beta(2) was safe as serum TGF-beta(2) did not increase, and renal and liver function were not affected during TGF-beta(2) consumption compared to normal feeding. Differences in toxicity, scored during the whole observation period and the number of days with WHO 3/4 toxicity, were not significantly different between cycles with TGF-beta(2) enriched and normal feeding. CONCLUSIONS: TGF-beta(2) administration via feeding is well tolerated and safe. Although this study might have had limitations to show potential benefit of TGF-beta(2), it does not provide evidence that TGF-beta(2) decreases the incidence or degree of mucositis induced by combination chemotherapy in childhood-cancer patients.

Muc2-deficient mice spontaneously develop colitis, indicating that MUC2 is critical for colonic protection.

BACKGROUND & AIMS: Expression of mucin MUC2, the structural component of the colonic mucus layer, is lowered in inflammatory bowel disease. Our aim was to obtain insight in the role of Muc2 in epithelial protection. METHODS: Muc2 knockout (Muc2(-/-)) and Muc2 heterozygous (Muc2(+/-)) mice were characterized and challenged by a colitis-inducing agent, dextran sulfate sodium (DSS). We monitored clinical symptoms, intestinal morphology, and differences in intestine-specific protein and messenger RNA levels. RESULTS: The Muc2(-/-) mice showed clinical signs of colitis (as of 5 weeks), aggravating as the mice aged. Microscopic analysis of the colon of Muc2(-/-) mice showed mucosal thickening, increased proliferation, and superficial erosions. Colonic goblet cells in the Muc2(-/-) mice were negative for Muc2, but trefoil factor 3 was still detectable. In Muc2(-/-) mice, transient de novo expression of Muc6 messenger RNA was observed in the distal colon. On day 2 of DSS treatment, the histologic damage was more severe in Muc2(+/-) versus wild-type (Muc2(+/+)) mice, but the disease activity index was not yet different. By day 7, the disease activity index and histologic score were significantly elevated in Muc2(+/-) versus Muc2(+/+) mice. The disease activity index of the Muc2(-/-) mice was higher (versus both Muc2(+/+) and Muc2(+/-) mice) throughout DSS treatment. The histologic damage in the DSS-treated Muc2(-/-) mice was different compared with Muc2(+/+) and Muc2(+/-) mice, with many crypt abscesses instead of mucosal ulcerations. CONCLUSIONS: This study shows that Muc2 deficiency leads to inflammation of the colon and contributes to the onset and perpetuation of experimental colitis.

Chemokine production by buccal epithelium as a distinctive feature of pediatric Crohn disease.

OBJECTIVES: Inflammatory bowel diseases (IBD) represent an aberrant immune response by the mucosal immune system to luminal bacteria. Because the oral mucosa harbors the first epithelial cells that interact with microorganisms, we assessed the immunologic activity of buccal epithelium in children with IBD and adults with Crohn disease. METHODS: Buccal epithelial cells were obtained from 17 children and 14 adults with Crohn disease, 18 children with ulcerative colitis, and 40 controls. Cells were cultured with and without microbial stimulation. Chemokine levels were determined in culture supernatants by cytometric bead array and enzyme-linked immunoabsorbent assay. CXCL-8 production was studied by immunohistochemical analysis of these cells. CXCL-8 production by lipopolysaccharide stimulated monocyte-derived dendritic cells from these patients was determined. RESULTS: Compared with controls, pediatric ulcerative colitis patients, and adult Crohn disease patients, only in children with Crohn disease did buccal epithelial cells exhibit enhanced production of CXCL-8, CXCL-9, and CXCL-10. In vitro stimulation with lipopolysaccharide or zymosan resulted in a further increase of chemokine levels only in cells from pediatric Crohn disease patients. CXCL-8 production by stimulated monocyte-derived dendritic cells from children with Crohn disease was equal to that of children with ulcerative colitis. CONCLUSIONS: Buccal epithelium of children with Crohn disease is immunologically active, even in the absence of oral lesions. The enhanced chemokine production is associated with pediatric Crohn disease and appears restricted to cells derived from the epithelial barrier. Assessment of chemokine production by buccal epithelial cells may become a new, rapid, noninvasive test for screening and classification of IBD in children.

Longitudinal follow-up of children with functional nonretentive fecal incontinence.

BACKGROUND & AIMS: Functional nonretentive fecal incontinence (FNRFI), incontinence in the absence of signs of fecal retention, is a frustrating phenomenon in children. No data on long-term outcome are available. The aim was to investigate the long-term outcome of FNRFI patients after intensive medical treatment. METHODS: Between 1990 and 1999, 119 patients (96 boys) with FNRFI were enrolled in 2 prospective, randomized trials investigating the effect of biofeedback training and/or laxative treatment. Follow-up (FU) was performed at 6 months, 1 year, and thereafter annually until September 2004. A standardized questionnaire was used to evaluate symptoms. Success was defined as a fecal incontinence frequency <1 per 2 weeks. RESULTS: Median age (25th-75th percentiles) was 9.2 years (range, 7.9-11.6 years). A 90% FU was achieved at all stages of the study. After 2 years of intensive therapy, 33 of 112 (29.5%) patients were successfully treated. The cumulative success percentage after 7 years of FU was 80%. At the biologic ages of 12 and 18 years, 49.4% (40/81) and 15.5% (9/58), respectively, of the patients still had fecal incontinence. Duration of fecal incontinence, with 4 years of age as the starting age for fecal incontinence (when a child should be toilet trained), was not related to successful outcome or relapse. Relapse occurred in 37% of patients. CONCLUSIONS: Only 29% of the patients with FNRFI were successfully treated after 2 years of intensive treatment. Despite recovery in the majority of patients beyond puberty, at age 18 years, 15% continued to have fecal incontinence.

The effect of cytostatic drug treatment on intestine-specific transcription factors Cdx2, GATA-4 and HNF-1alpha in mice.

Chemotherapy-induced intestinal damage is a very important dose-limiting side effect for which there is no definitive prophylaxis or treatment. This is in part due to the lack of understanding of its pathophysiology and impact on intestinal differentiation. The objective of this study was to investigate the gene expression of the small intestinal transcription factors HNF-1alpha, Cdx2, GATA-4 in an experimental model of methotrexate (MTX)-induced intestinal damage, and to correlate these alterations with histological damage, epithelial proliferation and differentiation. HNF-1alpha, Cdx2 and GATA-4 are critical transcription factors in epithelial differentiation, and in combination they act as promoting factors of the sucrase-isomaltase (SI) gene, an enterocyte-specific differentiation marker which is distinctly downregulated after MTX treatment. Mice received two doses of MTX i.v. on two consecutive days and were sacrificed 1, 3 and 7 or 9 days after final injection. Segments of the jejunum were taken for morphological, immunohistochemical and quantitative analyses. Intestinal damage was most severe at day 3 and was associated with decreased expression of the transcriptional factors HNF-1alpha, Cdx2 and GATA-4, which correlated well with decreased expression of SI, and seemed inversely correlated with enhanced proliferation of epithelial crypt cells. During severe damage, the epithelium was preferentially concerned with proliferation rather than differentiation, most likely in order to restore the small intestinal barrier function rather than maintaining its absorptive function. Since HNF-1alpha, Cdx2 and GATA-4 are critical for intestine-specific gene expression and therefore crucial in epithelial differentiation, these results may explain, at least in part, why intestinal differentiation is compromised during MTX treatment.

Infection with Helicobacter pylori affects all major secretory cell populations in the human antrum.

We have investigated how gastric H. pylori infection affects antrum secretory cell types by studying the expression of secretory proteins in antrum epithelium. Antrum biopsy specimens were prospectively collected from 102 individuals (49 H. pylori-infected). Immunohistochemistry was performed for secretory mucins (MUC5AC, MUC5B, MUC6), Trefoil factor family (TFF)-peptides (TFF1, TFF2), endocrine peptides (gastrin, chromogranin A), and proliferating cells (Ki-67). Protein expression was quantified morphometrically. H. pylori infection was significantly correlated to mucosal inflammation and to epithelial atrophy and proliferation. In H. pylori-infected patients the number of proliferating cells increased significantly, and the zone of proliferating cells shifted toward the surface epithelium of the antral glands. Infection was correlated with decreased MUC5AC, TFF1, and TFF2 expression and increased MUC6 and MUC5B expression. Endocrine cells expressing chromagranin A and gastrin shifted toward the surface epithelium of the antral glands in H. pylori-infected patients. H. pylori infection and concomitant inflammation induced increased epithelial proliferation and triggered coordinate deregulation of secretory cell populations in the antrum. In particular, infection led to a coordinated increase in cells expressing MUC6 and MUC5B at the expense of MUC5AC-producing cells.

Homeostasis and function of goblet cells during rotavirus infection in mice.

Rotaviruses are the leading cause of severe viral gastroenteritis in young children. To gain insight in goblet cell homeostasis and intestinal mucin expression during rotavirus infection, 6-day-old mice were inoculated with murine rotavirus. To determine epithelial cell migration, mice were injected with BrdU just before inoculation. Small intestines were isolated at different days postinfection (dpi) and evaluated for rotavirus and goblet cell-specific gene expression. Small intestinal mucins of control and infected animals at 1, 2, and 4 dpi were isolated and tested for their capability to neutralize rotavirus infection in vitro. After inoculation, two peaks of viral replication were observed at 1 and 4 dpi. During infection, the number of goblet cells in infected mice was decreased in duodenum and jejunum, but was unaffected in the ileum. Goblet cells in infected animals accumulated at the tips of the villi. Muc2 mRNA levels were increased during the peak of viral replication at 1 dpi, whereas at other time points Muc2 and Tff3 mRNA levels were maintained at control levels. Muc2 protein levels in the tissue were also maintained, however Tff3 protein levels were strongly decreased. The number of goblet cells containing sulfated mucins was reduced during the two peaks of infection. Mucins isolated at 1 and 2 dpi from control and infected mice efficiently neutralized rotavirus infection in vitro. Moreover, mucins isolated from infected mice at 4 dpi were more potent in inhibiting rotavirus infection than mucins from control mice at 4 dpi. In conclusion, these data show that during rotavirus infection, goblet cells, in contrast to enterocytes, are relatively spared from apoptosis especially in the ileum. Goblet cell-specific Muc2 expression is increased and mucin structure is modified in the course of infection. This suggests that goblet cells and mucins play a role in the active defense against rotavirus infection and that age-dependent differences in mucin quantities, composition, and/or structure alter the anti-viral capabilities of small intestinal mucins.

Adequate feeding and the usefulness of the respiratory quotient in critically ill children.

OBJECTIVE: We determined incidences of underfeeding and overfeeding in children who were admitted to a multidisciplinary tertiary pediatric intensive care and evaluated the usefulness of the respiratory quotient (RQ) obtained from indirect calorimetry to assess feeding adequacy. METHODS: Children 18 y and younger who fulfilled the criteria for indirect calorimetry entered our prospective, observational study and were studied until day 14. Actual energy intake was recorded, compared with required energy intake (measured energy expenditure plus 10%), and classified as underfeeding (<90% of required), adequate feeding (90% to 110% of required), or overfeeding (>110% of required). We also evaluated the adequacy of a measured RQ lower than 0.85 to identify underfeeding, and an RQ higher than 1.0 to identify overfeeding. RESULTS: Ninety-eight children underwent 195 calorimetric measurements. Underfeeding, adequate feeding, and overfeeding occurred on 21%, 10%, and 69% of days, respectively. An RQ lower than 0.85 to identify underfeeding showed low sensitivity (63%), high specificity (89%), and high negative predictive value (90%). An RQ higher than 1.0 to indicate overfeeding showed poor sensitivity (21%), but a high specificity (97%) and a high positive predictive value (93%). Food composition, notably high-carbohydrate intake, was responsible for an RQ exceeding 1.0 in the overfed group. CONCLUSION: Children admitted to the intensive care unit receive adequate feeding on only 10% of measurement days during the first 2 wk of admission. The usefulness of RQ to monitor feeding adequacy is limited to identifying (carbohydrate) overfeeding and excluding underfeeding.

The murine Muc2 mucin gene is transcriptionally regulated by the zinc-finger GATA-4 transcription factor in intestinal cells.

MUC2, the major mucin in the intestine, is expressed early during development and shows an altered expression pattern in intestinal bowel diseases. However, the mechanisms responsible for MUC2 expression in the intestine during these events are largely unknown. Having found putative GATA binding sites in the murine Muc2 promoter and that GATA-4 is expressed in Muc2-expressing goblet cells of the mouse small intestine, we undertook to study its regulation by this transcription factor. A panel of deletion mutants made in pGL3 vector and covering 2.2kb of the promoter were used to transfect the murine CMT-93 colorectal cancer cell line. The role of GATA-4 on Muc2 gene regulation was investigated by RT-PCR and co-transfections in the presence of expression vectors encoding either wild-type or mutated GATA-4 or by mutating the GATA-4 site identified within Muc2 promoter. Four GATA-4 cis-elements were identified in the promoter by EMSA and Muc2 promoter was efficiently activated when GATA-4 was overexpressed in the cells with a loss of transactivation when those sites were either mutated or a mutated form of GATA-4 was used. Altogether, these results identify Muc2, a goblet cell marker, as a new target gene of GATA-4 and point out an important role for this factor in Muc2 expression in the intestine.