ISSN:0277-2116    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0277-2116    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0277-2116    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0277-2116    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundIn patients with intact renal function and low dietary nitrate intake, plasma nitrate concentrations reflect endogenous nitric oxide production and are shown to be increased during inflammatory processes. The aim of this study was to compare plasma nitrate concentrations and hence endogenous nitric oxide production in children with infectious and noninfectious diarrhea and to determine whether plasma nitrate concentrations could serve as a discriminant test between acute and chronic diarrhea in children.MethodsThree groups of patients were identified: 14 patients with acute gastroenteritis, 13 patients with chronic noninfectious diarrhea, and 14 patients with no evidence of gastrointestinal pathology and no underlying infectious process, who served as control subjects. Plasma nitrate concentrations were determined spectrophotometrically using the Greiss reaction before reduction to nitrite with a copper-coated cadmium column.ResultsMean plasma nitrate concentrations were 405.3 &mgr;mol/L ± 281.6 &mgr;mol/L (standard deviation) in patients with infectious diarrhea, 134.7 &mgr;mol/L ± 77.0 &mgr;mol/L in patients with chronic diarrhea, and 54.1 &mgr;mol/L ± 20.1 &mgr;mol/L in control subjects (F = 42.6,P< 0.0001; analysis of variance). Plasma nitrate concentrations were significantly higher in the infectious diarrhea group compared with the noninfectious diarrhea and control groups (Student–Newman–Keuls test,P< 0.5).ConclusionsAlthough an optimal cutoff concentration cannot be defined, plasma nitrate concentrations in excess of 300 &mgr;mol/L are suggestive of an infectious process whereas values less than 100 &mgr;mol/L are indicative of noninfectious diarrhea.

ISSN:0277-2116    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundHistologic studies of rectosigmoidal mucosal biopsies of infants with isolated blood-streaked stool have shown many eosinophils and revealed aggregates of small dark granules (nuclear dust). However, no description of the nuclear dust has been made for this condition and the nature of the nuclear dust has not been thoroughly investigated. We determined the characteristics of these particles in biopsies from infants with streaked rectal bleeding.MethodsNineteen infants who were younger than 6 months old and had isolated rectal bleeding were studied, as were six age-matched control infants. Rectosigmoidal mucosal biopsies were immunohistochemically assessed using anticarcinoembryonic antigen and macrophage-associated antibodies and examined for apoptotic cells by modified in situ TdT-mediated dUTP-biotin nick-end labelling. The number of apoptotic epithelial cells was compared between rectal bleeding and control groups.ResultsImmunohistochemistry showed that at least some of the nuclear dust consisted of apoptotic epithelial cells. Infants with rectal bleeding also showed nodular lymphoid hyperplasia (n = 16), abundant eosinophils (>20/high power field, n = 14) in the mucosa, and a significantly high number of apoptotic epithelial cells relative to the control group. Rectal bleeding disappeared at 6-month follow-up in 14 of 18 infants (one was lost to follow-up) who were fed a different milk formula or breast-fed (their mothers were restricted from having cow's milk and eggs).ConclusionsThe high number of apoptotic epithelial cells in rectosigmoidal mucosal biopsies of infants with streaked rectal bleeding is probably caused by accelerated epithelial cell turnover and apoptosis.

ISSN:0277-2116    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundTo determine hepatic drug metabolism in patients with cystic fibrosis, as measured by monoethylglycinexylidide formation after lidocaine injection and indocyanine green (ICG) clearance.MethodsThe following study is a case–control study, which included 19 patients with cystic fibrosis and 13 control subjects. Serum monoethylglycinexylidide concentration was measured after intravenous injection of 1 mg/kg (maximum, 50 mg) lidocaine. Indocyanine green (0.5 mg/kg) was injected concomitantly, and absorbance (805 nm) of serum was measured over time to determine its volume of distribution, serum half-life, and hepatic blood flow.ResultsMonoethylglycinexylidide formation was decreased in patients with cystic fibrosis compared with controls (39.4 ± 16.9 &mgr;g/L versus 70.3 ± 45.7 &mgr;g/L, mean ± SD , respectively,P< 0.02). Indocyanine green half-life (4.6 ± 2.7 min versus 3.0 ± 1.0 min), volume of distribution (8.6 ± 5.5 L versus 8.3 ± 3.4 L), and hepatic blood flow (10.9 ± 5.9 ml · kg−1· min−1versus 7.4 ± 2.0 ml · kg−1· min−1) were similar in both groups.ConclusionMonoethylglycinexylidide formation after lidocaine injection is impaired in patients with cystic fibrosis. This impairment may have clinical implications when using hepatically metabolized medications in patients with cystic fibrosis.

ISSN:0277-2116    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundZinc is important for metabolism, cell growth, immunity, and defense against oxygen radicals. Extremely low-birth-weight (< 1000 g) infants have higher nutritional needs, but information on zinc is scarce. The authors performed nutritional balances in 10 infants with birth weights of 500 to 999 g and who were fed with fortified human milk.MethodsThe authors collected infant feces, urine, and blood and human milk samples during 72 hours at 7 and 12 weeks of age. Zinc concentration was measured by inductively coupled plasma–mass spectrophotometry, atomic emission spectro-photometry, and instrumental neutron activation analysis.ResultsMean (SD) intake via human milk was 379 (± 373) &mgr;g · kg−1· d−1during both balances. Urinary excretion was high at 7 weeks of age, decreased to half at 12 week, and was negatively correlated (P< 0.01) with weight gain. Mean absorption was slightly positive at 7 weeks of age but zero or negative in most infants at 12 weeks of age. Retention was negative in all infants at both observation periods, except in one infant during the second balance. Clinical zinc deficiency developed in one infant at 12 weeks of age.ConclusionsZinc balances in extremely low-birth-weight infants are highly variable and usually negative. Controlled trials are needed to assess need for and benefits and risks of zinc supplementation.

ISSN:0277-2116    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundUpper gastrointestinal endoscopic biopsies often show histologic abnormalities in Crohn disease. Consequently, it has been proposed that routine endoscopy could help to distinguish Crohn disease from ulcerative colitis. Surprisingly, however, recent case reports and an uncontrolled study suggested that similar abnormalities may occur in ulcerative colitis. Therefore, a blinded, controlled study was performed.MethodsEsophageal, gastric antral, and duodenal biopsies from children with Crohn disease (n = 28) and ulcerative colitis (n = 14) were compared with those from controls undergoing endoscopy for suspected reflux esophagitis (n = 22). Two pathologists, unaware of patient identity and diagnosis, agreed on a consensus report. Severity of inflammation was scored semiquantitatively.Helicobacter pyloricolonization was an exclusion criterion.ResultsInflammation was reported as follows: esophagitis: controls 91%; Crohn disease: 72%; ulcerative colitis: 50%; gastritis: controls: 27%; Crohn disease: 92% (P< 0.001); ulcerative colitis: 69%; duodenitis: controls: 9%; Crohn disease: 33%; ulcerative colitis: 23%. In Crohn disease, granulomas were noted in 40% of patients (P= 0.001). Duodenal cryptitis was noted in 26% of patients with Crohn disease but not ulcerative colitis. In one patient with ulcerative colitis, neutrophilic infiltration of gastric glands was seen. Abnormalities seen in Crohn disease and ulcerative colitis included gastroduodenal ulceration (Crohn disease, 7%; ulcerative colitis, 8%), villus atrophy (Crohn disease, 11%; ulcerative colitis, 15%), and increased intraepithelial lymphocytes (Crohn disease, 15%; ulcerative colitis, 31% [P< 0.05]). None of these abnormalities was noted in the controls.ConclusionAlthough the presence of granulomas can support a diagnosis of Crohn disease, severe inflammation and other abnormalities occur in the proximal gastrointestinal tract in Crohn disease and ulcerative colitis.

ISSN:0277-2116    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundThe Toll protein inDrosophilaregulates dorsal ventral patterning during embryogenesis, and participates in antibacterial and antifungal host defense. Mammalian homologues are termed Toll-like receptors and, to date, nine have been cloned (TLR1–9) in humans. They are characterized by extracellular leucine-rich repeats and a cytoplasmic domain similar to the interleukin 1 receptor. Both TLR2 and TLR4 recognize various bacterial cell wall components including lipopolysaccharide (LPS). This results in the activation of the NF&kgr;B pathway. Peripheral blood mononuclear cells (PBMCs) express both TLR2 and TLR4. The authors hypothesized that the expression of TLR 2 and TLR4 in human intestinal epithelial cells differs from PBMCs because of the abundance of LPS in the intestinal lumen.MethodsEpithelial cells were isolated from Caco-2 cells, fetal gut explants, and small bowel resection specimens using Hanks/ethylenediamine tetraacetic acid solution. PBMCs were used as positive controls. Ribonucleic acid (RNA) was isolated using the TRIzol method. Standard reverse transcription–polymerase chain reaction examined TLR2 and TLR4 messenger RNA (mRNA) expression. NF&kgr;B expression was determined using a luciferase reporter assay.ResultsTLR2 mRNA was highly expressed in PBMCs and was present in all human intestinal epithelial cells. TLR4 mRNA was detected only in PBMCs. TLR4 is not present in epithelium from children with inflammatory bowel disease. In Caco-2 cells, significant NF&kgr;B activation in response to LPS occurred only in the presence of TLR4 introduced by complementary deoxyribonucleic acid transfection.ConclusionAbsence of TLR4 is associated with endotoxin hyporesponsiveness of intestinal epithelial cells. TLR4 is not directly involved in inflammation of the intestinal epithelium. Although TLR2 is normally present in the epithelial cell, it plays a limited role in inflammation. It may be activated during conditions in which bacterial cell wall concentrations within the intestine are pathologically high.

ISSN:0277-2116    

出版商:OVID    

年代:2001

数据来源: OVID