Nutritional Management in Children and Adolescents with Severe Neurological Impairment-Who Cares? A Web-Based Survey Among Pediatric Specialists in Germany.

BACKGROUND: Nutritional management of children and adolescents with severe neurological impairment (SNI) is challenging. A web-based survey was distributed to identify the present situation and the knowledge of the involved medical professionals in Germany. METHODS: The survey was created with LimeSurvey, and access data were distributed by several medical societies. Eighty-three questions covered four topics: "general information," "gastro- and jejunostomy procedure," "handling of gastrostomies and feeding tubes," and "nutritional management and follow-up of children and adolescents with SNI." A descriptive analysis was performed with Microsoft Excel. RESULTS: A total of 156 participated (65 completed and 91 partially), 27% being pediatric gastroenterologists, 23% pediatric neurologists, and 10% pediatric surgeons. The most common indications for gastrostomy and tube feeding were oropharyngeal dysfunction and failure to thrive. Many patients were still underweight after some months of enteral feeding. The procedure of gastrostomy and handling recommendations varied broadly. Frequently, standard operating procedures (SOPs) and written local guidelines did not exist, and there was a considerable request for training. Only 53% of participants were aware of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition position paper published in 2017, even fewer (38%) followed the guidelines. The recommended measures to assess a nutritional status were often not respected. CONCLUSION: Nutritional management of children and adolescents with SNI in Germany is still strongly deficient. Despite the international guideline of 2017, few colleagues are aware of and adhere to the recommendations. This could be improved by interdisciplinary teaching and evaluation of the reasons for noncompliance. The procedure of gastrostomy and the patients' follow-up vary widely. Therefore, modified SOPs should be developed.

Fructose malabsorption in children with recurrent abdominal pain: positive effects of dietary treatment.

OBJECTIVE: The objective of this study was to analyze the effect of a fructose-restricted diet in otherwise healthy children with abdominal pain and pathologic fructose hydrogen breath test. SUBJECTS AND METHODS: 75 children (aging 3-14 years) with recurrent abdominal pain without gastrointestinal disease and fructose malabsorption followed a fructose restricted diet for 4 weeks. RESULTS: A median decline of weekly pain frequency from 4 (mean 3.64+1.6) before diet to 1 (mean 1.46+1.4; p<0.001) under fructose restriction was documented. The intensity of pain decreased from median 6 (mean 5.83+2.0) before intervention to median 3 (mean 3.4+2.5; p<0.001) with diet. Several additional life quality-influencing parameters such as daily stool frequency, nausea, problems to fall asleep, missed school days also improved significantly. CONCLUSIONS: Our study provides evidence that dietary fructose restriction represents a useful approach to address recurrent abdominal symptoms in children with fructose malabsorption.

Stem cell factor influences neuro-immune interactions: the response of mast cells to pituitary adenylate cyclase activating polypeptide is altered by stem cell factor.

Mast cells degranulation can be elicited by a number of biologically important neuropeptides, but the mechanisms involved in mast cell-neuropeptide interactions have not been fully elucidated. Stem cell factor (SCF), also known as c-kit or kit ligand, induces multiple effects on mast cells, including proliferation, differentiation, maturation, and prevents apoptosis. We investigated the ability of SCF to affect mast cell responsiveness to the neuropeptides pituitary adenylate cyclase activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP). PACAP 1-27, PACAP1-38, or VIP failed to induced preformed mediator release from mouse bone-marrow-cultured mast cells (BMCMC) derived in concanavalin A-stimulated spleen conditioned medium (CM). By contrast, BMCMC grown in SCF-containing medium or freshly isolated peritoneal mast cells exhibited significant 3H-hydroxytrypamine (5-HT) release in response to PACAP peptides or VIP. Deoxyglucose and the mitochondrial inhibitor antimycin significantly inhibited PACAP-induced 5-HT release indicating that the central event induced by PACAP peptides was exocytosis. The G(alpha)i inhibitor, pertussis toxin, significantly diminished PACAP-induced 5-HT release from BMCMCs in SCF suggesting the involvement of heterotrimeric G-proteins. Western blot analysis using antibodies directed against the human VIP type I/PACAP type II receptor demonstrated a 70-72 kD immunoreactive protein expressed in greater amounts in BMCMC grown in SCF compared with BMCMC in CM. We conclude that SCF induces a mast cell population that is responsive to PACAPs and VIP involving a heterotrimeric G-protein-dependent mechanism.

Mast cells contribute to PACAP-induced dermal oedema in mice.

In the present study the effect of intradermal PACAP-injection on dermal oedema in mice was investigated and the contribution of mast cells to this response was assessed. The injection of PACAP 1-38 into the ears of C57BL/6 mice evoked a dose-dependent response, which, after higher doses of PACAP 1-38, lasted at least 24 h. Histological examination showed significant mast cell degranulation induced by PACAP. Using mast cell-deficient WBB6F1-Kit(W)/Kit(W-v) mice and the congenic mice, we demonstrated that the the early phase (30 min to 6 h) of PACAP-induced ear swelling response was significantly diminished in mast cell-deficient mice, suggesting that mast cell degranulation contributes to this phase of the response. When mast cell-deficient WBB6F1-Kit(W)/Kit(W-v) mice were locally and selectively reconstituted by adoptive mast cell transfer, the dermal oedema was almost equal to that of control animals in the early phase of PACAP injection. These results show that mast cell degranulation contributes to PACAP-induced dermal oedema in mice.

Pituitary adenylate cyclase activating polypeptide induces multiple signaling pathways in rat peritoneal mast cells.

Pituitary adenylate cyclase activating polypeptide (PACAP) is a high-affinity ligand for at least two types of G-protein coupled receptors, the PACAP type 1 and type 2 receptor. In this study it is demonstrated that the C-terminal PACAP-fragment PACAP(6-27) stimulates serotonin release from rat peritoneal mast cells with higher potency (EC50: 0.2 vs. 2.0 microM) than the PACAP receptor ligand PACAP(1-27). PACAP-induced degranulation of rat peritoneal mast cells was abolished by pertussis toxin and by benzalkonium chloride (IC50: 9.1 microg/ml) indicating the involvement of heterotrimeric G-proteins of the Gi-type. The PACAP effect was also reduced by inhibitors of the phosphatidylinositol specific phospholipase C ((U73122), IC50: 4 microM; (ET-18-O-CH3), IC50: 18 microM), by D609, a specific inhibitor of the phosphatidylcholine specific phospholipase C (IC50: 41 microM), by the protein kinase C-inhibitor staurosporine (IC50: 0.6 microM) and by the lipoxygenase inhibitor nordihydroguaiaretic acid (NGDA) but not by indomethacin. It is concluded that PACAP peptides stimulate secretion in rat peritoneal mast cells in a PACAP receptor-independent manner, probably via direct activation of heterotrimeric G-proteins of the Gi-type; these G-proteins may lead to a sequential activation of different signaling cascades (see above), which may converge at the level of one or more staurosporine-sensitive protein kinase.

Pituitary adenylate cyclase activating polypeptide induces degranulation of rat peritoneal mast cells via high-affinity PACAP receptor-independent activation of G proteins.

In this study, the secretory effects of PACAP and PACAP analogues on [3H]serotonin-loaded purified rat peritoneal mast cells (RPMCs) were investigated. PACAP(1-27) and PACAP(6-27) stimulated [3H]serotonin release with low potency (ED50: 2 x 10(-6) M) but high efficacy. The N-terminally truncated PACAP form, PACAP(6-27), stimulated tracer release with an ED50 of 0.2 x 10(-6) M, indicating a high-affinity PACAP receptor-independent mechanism of action. The secretory response to PACAP(1-27) could be inhibited by 60-min preincubation with pertussis toxin (ptx), which inhibits G proteins. U73122, a cell-permeable phospholipase C inhibitor, dose-dependently inhibited the secretory effect of 5 microM PACAP(1-27) with an IC50 value of 4 microM (N = 4; p < 0.006). We conclude that PACAP exerts a secretory effect in RPMCs by high-affinity PACAP receptor-independent direct activation of one or more G proteins, which may then activate the PLC-dependent signal-transduction pathway.

Mast cell-dependent tumor necrosis factor alpha production participates in allergic gastric inflammation in mice.

BACKGROUND & AIMS: Immunoglobulin E-dependent gastric inflammation is characterized by neutrophil infiltration, and mast cells are required for this response. The aim of this study was to examine whether mast cell production of tumor necrosis factor (TNF)-alpha participates in the recruitment of neutrophils during this response. METHODS: The levels of TNF-alpha messenger RNA (mRNA) and protein in gastric tissues were assessed by Northern blot analysis and enzyme-linked immunosorbent assay. In situ hybridization and histochemical staining were performed to identify the cells expressing TNF-alpha transcripts. Anti-TNF-alpha antibodies or cyclosporine A were used in an attempt to inhibit neutrophil infiltration. RESULTS: TNF-alpha mRNA and protein were increased in gastric tissues undergoing immunoglobulin E-dependent inflammation. Mast cells were required for the development of cells expressing TNF-alpha transcripts in the stomach. Seventy-nine percent of the cells in the mucosa and 100% of the cells in the submucosa expressing TNF-alpha mRNA were identified as mast cells. Anti-TNF-alpha antibodies inhibited neutrophil infiltration in the submucosa, and cyclosporine A inhibited the tissue expression of TNF-alpha mRNA and the influx of neutrophils into the submucosa and muscularis propria. CONCLUSIONS: These findings show that mast cell-derived TNF-alpha is at least one of the mediators involved in the recruitment of neutrophils during immunoglobulin E-dependent gastric inflammation in the mouse.

The regulation of tumor necrosis factor-alpha production in murine mast cells: pentoxifylline or dexamethasone inhibits IgE-dependent production of TNF-alpha by distinct mechanisms.

Mast cells activated via high-affinity receptors for IgE can produce a variety of multifunctional cytokines, including TNF-alpha, which is thought to be involved in the pathophysiology of allergic diseases and other inflammatory disorders. We investigated the regulation of Fc Fc epsilon RI-dependent TNF-alpha production by mouse mast cells using dexamethasone and pentoxifylline, pharmacological agents which are known to suppress TNF-alpha production by macrophages. We now report that either dexamethasone or pentoxifylline can inhibit IgE-dependent mouse mast cell production of TNF-alpha; however, the major site of action of these agents was different. Pentoxifylline inhibited mast cell TNF-alpha gene transcription, while dexamethasone inhibited TNF-alpha production predominantly by a post-transcriptional mechanism. These results demonstrate that the synthesis of mast cell TNF-alpha can be regulated pharmacologically at either the transcriptional or the translational level and that pentoxifylline and dexamethasone, two agents that are used to treat inflammatory disorders, can modulate mast cell TNF-alpha production at different points in the synthetic pathway of this cytokine.