Cyclic vomiting syndrome: a pediatric Rorschach test.
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Child↗
Biomedical subjects
B U Li
Publications and source records attributed to B U Li.
Lactose flux occurs by differing mechanisms in the colon and jejunum of newborn piglets.
The unidirectional flux of 10- and 40-mM lactose was studied in newborn porcine jejunum and colon mounted in Ussing chambers. Polyethylene glycol 400 was used to measure passive paracellular permeability. The mucosal-to-serosal flux and the tissue accumulation of labeled lactose from the colon was similar to that of lactose-derived glucose from the jejunum. However, only jejunum showed a lactose-stimulated increase in short-circuit current. In jejunum, glucose was the sole sugar identified in the serosal bath, whereas in colon, only intact lactose was identified. Despite colonic lactose flux, polyethylene glycol oligomers were not found in the serosal bath, suggesting that they do not share the same route of absorption. Colonic lactose transport was nonsaturable between 1 and 40 mM. Under nongradient conditions, no net colonic lactose transport was observed. Cumulatively, these data suggest that the colon, unlike the jejunum, does not contain a glucose-galactose sodium cotransporter. The colon of the newborn piglet transports intact lactose at a flux equal to that of lactose-derived glucose by the small intestine, but by a different mechanism that is as yet undefined.
Animals↗
Is combination therapy for encopresis nutritionally safe?
Chronic constipation accounts for 3% to 5% of pediatric primary care outpatient visits. The most severely affected of this group develop a flaccid colon insensitive to distention, and encopresis. Laxatives and lubricants have been the standard therapeutic agents during the bowel decompression phase of encopretic therapy. Fiber has been the cornerstone of maintenance programs. Each of these agents is accompanied by considerable anxiety in the lay literature. This study evaluates the safety of combined high-fiber, laxative, and lubricant therapy on bowel movement frequency, fecal soiling, and nutritional status over a 6-month period. Blood chemistry values, dietary fiber intake, defecation pattern, and psychological profile were evaluated before and after the 6-month study. Biochemical and anthropometric indicators of nutritional status were not adversely affected by the therapy. Seventy-five percent of the children were able to remain free of soiling and the remaining 4 of 16 had soiling episodes reduced to a frequency of less than once a week. This study confirms that children with encopresis can respond to a combined program of increased fiber intake, laxatives, and mineral oil following a complete bowel cleanout, without experiencing deleterious effects.
Cathartics↗
Rice-induced anaphylactoid reaction.
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Anaphylaxis↗
Urinary medium-chain acylcarnitines in medium-chain acyl-CoA dehydrogenase deficiency, medium-chain triglyceride feeding and valproic acid therapy: sensitivity and specificity of the radioisotopic exchange/high performance liquid chromatography method.
To determine the sensitivity and specificity of detecting urinary medium-chain acylcarnitines for the diagnosis of MCAD deficiency, 114 urine specimens from 75 children with metabolic diseases and controls were analyzed in a blinded fashion using a radioisotopic exchange/HPLC method. All 47 patients with MCAD deficiency were correctly diagnosed using the criterion hexanoylcarnitine or octanoylcarnitine peak areas larger than those of other medium-chain acylcarnitines. The majority of them were tested during the asymptomatic state without L-carnitine loading. Four patients with other defects of fatty acid oxidation and three patients receiving valproic acid had a similar acylcarnitine excretion pattern. To further examine the specificity of the method, eight infants receiving a diet enriched with medium-chain triglycerides and 13 additional patients receiving valproic acid were studied. Most of these also tested positive for MCAD deficiency by the above criterion. Analysis by a new gas chromatographic-mass spectrometric procedure revealed that octanoylcarnitine, not valproylcarnitine, was the most abundant medium-chain carnitine ester excreted by a patient treated with valproic acid. Quantitation of urinary hexanoylcarnitine and octanoylcarnitine showed considerable overlap among patients with MCAD deficiency and those receiving valproic acid or a medium-chain triglyceride-enriched diet. MCAD deficiency can be reliably detected in urine specimens by this method without the need for prior carnitine loading. However, other defects in fatty acid oxidation must be differentiated from MCAD deficiency, and a history of medium-chain triglyceride or valproic acid administration must be considered if the diagnosis of MCAD deficiency is sought through analysis of urinary acylcarnitines.
Acyl-CoA Dehydrogenase↗
Enterohepatic distribution of carnitine in developing piglets: relation to glucagon and insulin.
L-Carnitine plays a crucial role in the perinatal transition from carbohydrate to lipid-derived energy. To examine the potential contribution of assimilated dietary carnitine to the elevated hepatic concentrations in newborns, we measured carnitine concentrations in sow milk, jejunum, and liver, and in vitro jejunal carnitine transport in piglets aged 1-36 d. Hepatic and sow milk total carnitine concentrations peaked soon after birth and declined with age (p = 0.035 and 0.026, respectively). Although jejunal total carnitine concentrations remained stable, jejunal carnitine flux was higher at 2 d of age than in older piglets. To examine the possible signals that regulate hepatic carnitine, portal enteroinsular hormones were measured by RIA. Portal glucagon (p = 0.0006), insulin (p = 0.0001), and glucagon:insulin ratio (p = 0.037) were related to age. Portal glucagon was highest in newborns and during weaning, whereas insulin increased progressively with age; the portal glucagon:insulin ratio, like hepatic carnitine, peaked soon after birth and fell with age. A multiple regression analysis indicated a positive association between glucagon and hepatic carnitine and a negative one between insulin and hepatic carnitine (R = 0.802, p = 0.001). An overall pattern of elevated dietary carnitine levels and increased small intestinal absorption and hepatic accumulation of carnitine is noted in early development. The finding of a similar pattern in glucagon-to-insulin ratio suggests that both hormones may participate in the regulation of enterohepatic carnitine distribution in newborns.
Aging↗
Recurrent pancreatitis in three patients with chronic idiopathic intestinal pseudo-obstruction.
Chronic idiopathic intestinal pseudo-obstruction is a syndrome with substantial morbidity and mortality associated both with the syndrome and with its therapy. Standard therapy has included prokinetic agents and intravenous nutritional support when oral feedings are inadequate to maintain nutriture. We report three children with chronic intestinal pseudo-obstruction who experienced one or more attacks of pancreatitis. Two patients developed pseudocysts. One patient died. All three patients underwent cholecystectomy; one had stones, one had acalculous cholecystitis, and one had a normal gallbladder. All patients received prokinetic agents and total parenteral nutrition as therapy for their pseudo-obstruction. Candidate mechanisms to explain the etiology for pancreatitis in chronic intestinal pseudo-obstruction include biliary dysmotility associated with pseudo-obstruction and excessive cholinergic stimulation due to therapy with prokinetic agents.
Child↗
Absorption of lactose from colon of newborn piglet.
Piglets in three age groups (1-3, 9-11, and 16-25 days after birth) were used for in vivo colonic perfusions. Studies compared an isosmolar (312 mosM) with a high osmolar (551 mosM) solution and two equimolar substrates (with hexose concentrations of 73.1 mM), lactose and glucose-galactose. From the isosmolar perfusates, lactose absorption was 0.43 +/- 0.04 in the 18-20 day olds and 1.04 +/- 0.2 mumol.cm-1.min-1 in the 1-3 day olds; absorption from the glucose-galactose solution was negligible in all age groups (less than 0.05 +/- 0.05 mumol.cm-1.min-1). From the high osmolar perfusate, lactose absorption also exceeded that of glucose and galactose. In a third set of perfusion studies, the concentration of lactose was varied between 15 and 240 mM perfusate. Five-day-old animals absorbed 67% more lactose than 18-day-old animals; the right colon absorbed 57% more than the left. Lactose absorption, correlated with its concentration in the perfusate (r = 0.99), was nonsaturable at concentrations up to 240 mM, and was correlated with the uptake both of sodium (r2 = 0.59 for young and 0.64 for older neonates) and of chloride (r2 = 0.55 for young and 0.31 for older neonates). The results suggest that lactose may be removed from the colon without apparent cleavage by beta-galactosidase.
Animals↗
Glucose flux from dietary disaccharides: all sugars are not absorbed at equal rates.
Considerable discrepancies exist in the literature regarding the rates of glucose absorption from the common dietary disaccharides, lactose, maltose, and sucrose. This study compared the unidirectional flux of glucose derived from dietary disaccharides with that of their constituent monosaccharides in vitro. Lactose-stimulated short-circuit current (Isc) and mucosal-to-serosal flux (Jm----s) were lower than that of an equimolar glucose-galactose mixture and were phlorizin inhibitable. Maltose- and glucose-stimulated Isc were similar, but Jm----s of glucose derived from the hydrolysis of maltose was lower than that of free glucose. Sucrose-stimulated Isc and Jm----s were similar to that of an equimolar glucose-fructose mixture. Isc and Jm----s of glucose from both maltose and sucrose were phlorizin and acarbose inhibitable. We conclude that the rate of glucose uptake from disaccharides is less than or equal to that of free glucose and is dependent on the glucose source. We speculate that regulation of glucose uptake from disaccharides can occur at three sites: the hydrolytic enzyme, the glucose transporter, and the tight junctions.
Absorption↗
Failure to conserve lactose and glucose polymers during frozen storage of fecal specimens: methods for preservation.
Freezing is often used to retard bacterial enzymatic activity in fecal specimens collected to quantify specific carbohydrates. The effectiveness of freezer storage on preservation of lactose and glucose polymers was assessed. The data showed that more than 50% of lactose that was added to fecal supernatants that were stored without treatment for more than 50 days at -20 degrees C was lost. Adjustment of pH with HCl (pH 4.9), with HgCl2 (pH 6.3 or 5.85), or with NaOH (pH 10) improved carbohydrate preservation (P less than 0.0004). Storage of the supernatants of fecal homogenates lessened the loss of carbohydrate compared with the total homogenates (P less than 0.001). In supernatants, degradation occurred via simple hydrolysis; in homogenates, degradation occurred by hydrolysis and fermentation to a variety of end-products. Unprocessed fecal specimens that were frozen for months, then retrieved and incubated with lactose or glucose polymers showed extensive fermentative capacity. Cumulatively, the data indicate that enzymatic activity in feces is not halted by storage in the freezer, even if bacteria have been filtered from the stool.
Animals↗
Uptake of L-carnitine by rat jejunal brush border microvillous membrane vesicles. Evidence of passive diffusion.
We have previously described apparent active transport of carnitine into rat intestinal mucosa with intracellular accumulation against a concentration gradient in a process dependent upon the presence of sodium ions, oxygen, and energy. In the work described here, we sought to define the interaction between carnitine and the brush border membrane, which we presumed contained the transport mechanism. Using isolated rat jejunal brush border microvillous membrane vesicles, we found evidence of passive diffusion alone. We found no evidence of carrier-mediated transport--in particular no saturation over a concentration range, inhibition by structural analogs, transstimulation phenomenon, and no influence of sodium ions, potential difference or proton gradients. We conclude that a carnitine transporter does not exist in the brush border membrane of enterocytes and that other cellular mechanisms are responsible for the apparent active transport observed.
Animals↗
Efficacy and safety of a diazepam and meperidine combination for pediatric gastrointestinal procedures.
Little has been published about outpatient sedation for pediatric patients. We designed a study to evaluate the efficacy and adverse effects of diazepam and meperidine in combination for sedation in ambulatory pediatric patients undergoing endoscopy, colonoscopy, or liver biopsy. Thirty patients (7 months-20 years) were observed. Each patient received a single combined dose of intravenous diazepam and meperidine. The standard dose was 0.1 mg/kg for diazepam and 2.0 mg/kg for meperidine. In patients weighing greater than 100 lb, set doses of meperidine (100 mg) and diazepam (5 mg) were used. The time to achieve sedation and the vital signs were measured; cooperation, emotional state, and drowsiness were rated before, during, and after procedures. The amnesic effect was noted, as were any adverse effects. Diazepam and meperidine were effective in 26 of 30 patients, with sedation generally produced within 2-3 min. Cooperation and emotional state improved significantly following drug administration (p less than 0.05). When a prospective 24-h telephone follow-up study was instituted in 40 consecutive patients receiving diazepam and meperidine no significant adverse effects were noted. Only 20% of patients old enough to be questioned remembered the procedure. Diazepam and meperidine in combination appear to be effective and safe in pediatric patients undergoing gastrointestinal procedures. Prolonged monitoring of patients does not appear necessary in this patient population.
Adolescent↗
Cisapride for intractable constipation in children: observations from an open trial.
Twelve patients with chronic constipation refractory to the vigorous use of emollients, enemas, and/or laxatives were chosen for study of the investigational prokinetic agent, Cisapride. The patients included 8 boys and 4 girls with diagnoses of functional constipation. Ages ranged from 2 to 13 years; duration of symptoms before Cisapride use ranged from 1.5 to 9.75 years; duration of previous treatment ranged from 0.75 to 6 years. The mean number of doses of anticonstipation agents employed per week was 14. Of the 12 patients, 10 had persistent encopresis, while 11 required hospitalization for disimpaction an average of 1.6 times in the year prior to Cisapride use. Three had chronic urinary tract complaints. Anal manometry suggested a sensory deficit in 8 of 10 patients tested. Ganglion cells were identified by rectal biopsy in all 12 patients. Cisapride treatment (0.14-0.3 mg/kg/dose) spanned 26-72 weeks (61 +/- 12). Stool frequency per week was not significantly changed, but five of seven patients who had reported hard stools had softer stools on the drug (p less than 0.05). Encopresis ceased in 8 of 10 cases, while the number of episodes decreased substantially in the other 2 cases (p less than 0.05). All alternate forms of anticonstipation therapy were withdrawn in 8 of 12 cases (p less than 0.001). Urinary problems improved in two of the three patients reporting symptoms. One patient showed no improvement in any parameter while on the agent, despite 26 weeks of administration. Side effects were infrequent, generally occurred early, and were limited to cramping, nausea, mild vomiting, anorexia, and headaches. One patient ceased use of the drug for persistent headaches.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Stimulatory effects of short-chain fatty acids on colonic absorption in newborn piglets in vivo.
This study examined the absorption of short-chain fatty acids (SCFA) and their effects on colonic conservation of water and sodium. Newborn York piglets, 2-23 days of age and exclusively suckled, were studied comparing absorption from a control/electrolyte solution with that from a SCFA solution. The results indicated that SCFA absorption is highest at birth, with a rapid decline over 72 h to a lower and relatively stable level. During the control perfusions, water and sodium absorption increased with age. The addition of SCFA to the perfusate stimulated both water and sodium uptake in the first 2 weeks. After the 14th day, sodium absorption continued to be enhanced by SCFA, but water movement remained unchanged from control levels. Right and left colon responses were similar. The results suggest that although luminal SCFA levels may be limited early in life, the presence of SCFA has stimulatory effects on the absorption of sodium and water from the colon in newborns.
Animals↗
Sulfasalazine-induced hepatotoxicity in children with inflammatory bowel disease.
A case of severe sulfasalazine-induced hepatotoxicity is reported in a 14-year-old girl with Crohn's disease. Fourteen days after beginning sulfasalazine, she developed a systemic reaction characterized by high fever, maculopapular rash, lymphadenopathy, abdominal pain, and malaise, with tender hepatomegaly and elevated liver functions, leukemoid reaction, with eosinophilia, and immune complexes. She responded promptly to high-dose intravenous steroids with complete recovery. This case was compared to the three similar pediatric cases in the literature. The latent period was 11-19 days between sulfasalazine therapy and the onset of high fever, generalized lymphadenopathy, and pruritic maculopapular rash that spared palms and soles and resolved with desquamation. All children had hepatotoxicity indicated by tender hepatomegaly, elevated liver enzymes, and histologic inflammation on liver biopsy. The similarity between these features and those of other sulfa-induced hepatotoxic reactions suggests that the sulfapyridine moiety is the etiologic agent in these hypersensitivity reactions. Those children with circulating immune complexes responded well to steroids. Proper therapy for this rare but severe idiosyncratic reaction includes prompt recognition and discontinuation of sulfasalazine, and high-dose corticosteroid therapy.
Adolescent↗
Digestion, absorption, and fermentation of carbohydrates.
Newborn infants born after a term gestation appear to have an adequate capacity for small intestinal digestion and absorption of carbohydrate. Premature infants do not have a mature level of intestinal lactase activity. Apparently, in the premature infant, colonic fermentation serves an important, if not the only major route, for lactose carbon absorption, and it also appears that signs of fermentation activity such as increased BH2 are not indicative of disease. Important questions remaining in the premature infant relate to developmental aspects of colonic fermentative activity, effects of systemic antibiotic treatment on colonic salvage, the effects of various fermentation pathways on energy balance, the capacity for absorption of sugars, SCFA, and electrolytes by colonic epithelia, and the effects of fermentation products on metabolism and on the mucosal cells of the intestine or colon. Research addressing these questions may have relevance in the following areas: further development of formula diets for healthy premature infants and for patients of all ages with intestinal or colon dysfunction; the effects of colonic disease or surgical resection; the nutritional or clinical effects of dietary fiber; and the effects of antibiotic therapy on intestinal and colon function.
Animals↗
Short-chain fatty acid profile in the colon of newborn piglets using fecal water analysis.
Short-chain fatty acid production and assimilation is unlikely to occur at significant levels in the newborn because the colon at birth is sterile, and only gradually acquires an anaerobic flora. This study profiled short-chain fatty acid levels in the colon lumen over the initial 21 days of life. Fecal samples were removed surgically from the cecum, right, and left colon from 36 York piglets, 0-21 days of life. Samples were subjected to in vitro dialysis and centrifugation methods to quantitate fecal water short-chain fatty acids, electrolytes, osmolality, and pH. A three-way analysis of variance examined piglet age, colon site of fecal samples, and method of fecal water analysis, for each variable. No differences were found between techniques of fecal water collection. Newborns showed production of short-chain fatty acids as early as the 1st day of life in limited amounts. Levels were stable between days 5 and 14, and then abruptly accumulated in the lumen. Acetate was predominant early, with propionate and butyrate responsible for late peaks. The production and assimilation of short-chain fatty acids was nearly complete proximal to the left colon. Age and colon site showed significant interactions for each fatty acid (p less than 0.001). The combined osmolar contributions of short-chain fatty acids and electrolytes accounted completely for the luminal osmolality after the 2nd wk of life. Previously there was an "osmolar gap" suggesting that lactose or its breakdown products were present in the lumen and were being removed by pathways other than through short-chain fatty acid production.
Anaerobiosis↗
Recurrent abdominal pain in childhood: an approach to common disorders.
Recurrent abdominal pain is a challenging clinical problem for which the rewards are the return of the ill or disabled child to an active life. I hope that the approach outlined here will hasten recovery, reduce iatrogenesis, and potentially lessen lifelong pain in these children.
Abdomen↗