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Biomedical subjects

M E Ament

Publications and source records attributed to M E Ament.

At least 19 recordsLinked to original sources
PubMed1996

Malabsorption of apple juice and pear nectar in infants and children: clinical implications.

Ingestion of fruit juices in which there is an imbalance between glucose and fructose (apple, pear nectar) and the presence of sorbitol is one of the major causes of the syndrome of chronic, nonspecific diarrhea of infancy and childhood. Stools in the condition at time of symptoms are acidic with a pH < 5.5, Clinitest positive, but free of blood and white cells. Lactose and sucrose breath hydrogen tests are normal but breath hydrogen is elevated if measured between 60-120 minutes after the offending juice is taken in sufficient quantity to elicit symptoms. Elimination of the offending juices immediately stopped the diarrhea in all of the cases. Three cases are presented documenting the variability of symptoms including one adolescent who became symptomatic while on a fruit and juice diet.

Beverages↗
PubMed1996

Chronic liver disease in children on long-term parenteral nutrition.

Use of long-term total parenteral nutrition (TPN) is often presumed to be associated with serious hepatic dysfunction. In this retrospective study, we reviewed the complete charts of patients who had received TPN for more than 2.5 years, starting in infancy or childhood, for evidence of liver dysfunction. There were 16 male and 10 female patients with a total of 254.5 patient years on TPN. Seventeen patients have been on TPN since birth or early infancy. Thirteen of 26 patients derive > or = 90% of their calorie intake from TPN. Six patients had hepatomegaly; two of them also had splenomegaly. Twenty-one patients had normal transaminases, nine have had past episodes of raised enzymes ranging from 2.5 to 7.5 times normal. Seventeen patients always had normal bilirubin levels, five had past episodes of hyperbilirubinaemia, while four patients had persistently raised bilirubin levels (range 1.5-20.7 g/dl). Alkaline phosphatase was normal for age in all patients except two. Hepatic synthetic function, as measured by albumin, pre-albumin levels and prothrombin time, was within the normal range in all patients except one. Liver biopsies were performed in eight patients. Two biopsies showed cirrhosis, one showed chronic active hepatitis (CAH) with cholestasis, two patients had fibrosis, one showed cholestasis and two biopsies were normal. One patient with cirrhosis and one with CAH were positive for hepatitis C antibody. Another asymptomatic patient was positive for hepatitis B. Only the patient with CAH had hepatic decompensation. We conclude that clinical hepatic failure is uncommon in our group of patients on long-term TPN for 2.5 years or more. Cirrhosis and fibrosis, when found, could not be solely attributed to TPN.

Adolescent↗
PubMed1996

Gastroesophageal reflux in childhood.

Gastroesophageal reflux (GER) is one of the most frequent symptomatic clinical disorders affecting the gastrointestinal tract of infants and children. During the past 2 decades, GER has been recognized more frequently because of an increased awareness of the condition and also because of the more sophisticated diagnostic techniques that have been developed for both identifying and quantifying the disorder. Gastroesophageal fundoplication is currently one of the three most common major operations performed on infants and children by pediatric surgeons in the United States. Normal gastroesophageal function is a complex mechanism that depends on effective esophageal motility, timely relaxation and contractility of the lower esophageal sphincter, the mean intraluminal pressure in the stomach, the effectiveness of contractility in emptying of the stomach, and the ease of gastric outflow. More than one of these factors are often abnormal in the same child with symptomatic GER. In addition, in patients with GER disease, and particularly in those patients with neurologic disorders, there appears to be a high prevalence of autonomic neuropathy in which esophagogastric transit and gastric emptying are frequently delayed, producing a somewhat complex foregut motility disorder. GER has a different course and prognosis depending on the age of onset. The incompetent lower esophageal sphincter mechanism present in most newborn infants combined with the increased intraabdominal pressure from crying or straining commonly becomes much less frequent as a cause of vomiting after the age of 4 months. Chalasia and rumination of infancy are self-limited and should be carefully separated from symptomatic GER, which requires treatment. The most frequent complications of recurrent GER in childhood are failure to thrive as a result of caloric deprivation and recurrent bronchitis or pneumonia caused by repeated pulmonary aspiration of gastric fluid. Children with GER disease commonly have more refluxing episodes when in the supine position, particularly during sleep. The reflux of acid into the mid or upper esophagus may stimulate vagal reflexes and produce reflex laryngospasm, bronchospasm, or both, which may accentuate the symptoms of asthma. Reflux may also be a cause of obstructive apnea in infants and possibly a cause of recurrent stridor, acute hypoxia, and even the sudden infant death syndrome. Premature infants with respiratory distress syndrome have a high incidence of GER. Esophagitis and severe dental carries are common manifestations of GER in childhood. Barrett's columnar mucosal changes in the lower esophagus are not infrequent in adolescent children with chronic GER, particularly when Heliobacter pylori is present in the gastric mucosa. Associated disorders include esophageal dysmotility, which has been recognized in approximately one third of children with severe GER. Symptomatic GER is estimated to occur in 30% to 80% of infants who have undergone repair of esophageal atresia malformations. Neurologically impaired children are at high risk for having symptomatic GER, particularly if nasogastric or gastrostomy feedings are necessary. Delayed gastric emptying (DGE) has been documented with increasing frequency in infants and children who have symptoms of GER, particularly those with neurologic disorders. DGE may also be a cause of gas bloat, gagging, and breakdown or slippage of a well-constructed gastroesophageal fundoplication. The most helpful test for diagnosing and quantifying GER in childhood is the 24-hour esophageal pH monitoring study. Miniaturized probes that are small enough to use easily in the newborn infant are available. This study is 100% accurate in diagnosing reflux when the esophageal pH is less than 4.0 for more than 5% of the total monitored time.

Adult↗
PubMed1996

Orofacial lesions in Crohn's disease.

We describe a female patient with Crohn's disease who presented with longstanding gingival swelling. She went into remission after surgery, but had labial involvement while in remission. A review of the literature is presented with special reference to the clinical characteristics of orofacial Crohn's disease and Melkersson-Rosenthal syndrome, which can mimic such presentation of Crohn's disease.

Adult↗
PubMed1995

Overinterpretation of gastroduodenal motility studies: two cases involving Munchausen syndrome by proxy.

Two children were thought to have an atypical gastroduodenal motility disorder because of the history and clinical course; both had received parenteral alimentation because of claims of inability to tolerate enteral feedings, and both continued to have unusual medical problems during parenteral alimentation. Both children had motility studies that were interpreted by a pediatric gastroenterologist to be "abnormal" and "diagnostic" of a motility disorder, but each was eventually shown to have a behavioral abnormality related to Munchausen syndrome by proxy.

Child, Preschool↗
PubMed1995

Excessive urinary oxalate excretion occurs in long-term TPN patients both with and without ileostomies.

OBJECTIVE: To determine if excessive oxalate and deficient citrate excretion were associated with TPN-associated nephropathy. DESIGN: Crossectional cohort. SETTING: Outpatient clinic. SUBJECTS: Twenty-five patients (15 males, 10 females) aged 51 +/- 17 (mean +/- SD) years who had received home total parenteral nutrition (TPN) for 10 +/- 4 years. Fifteen subjects had ileostomies (Group A) and 10 had functional colons (Group B). OUTCOME MEASURES: Glomerular filtration rate (GFR), tubular reabsorption of phosphate (TRP), urinary oxalate and citrate excretion. RESULTS: The mean GFR was 68.1 +/- 34.5 ml/minute/1.73 m2 and did not differ between Groups A and B. The mean TRP was 65.0 +/- 32.2% for Group A and 80.5 +/- 16.0% for Group B. The difference was not statistically significant. Urinary oxalate and citrate excretion were 40.2 +/- 30.2 and 324.4 +/- 239.0 mg/day respectively for Group A, and 63.2 +/- 34.2 and 474.8 +/- 936.3 respectively for Group B. The differences were not statistically significant. Thirty-eight percent (38%) of patients with ileostomies and 78% of patients without ileostomies had excessive urinary oxalate excretion (> 40 mg/day). Fifteen percent (15%) of patients with ileostomies and 50% of patients without ileostomies had decreased urinary citrate excretion (< 140 mg/day). CONCLUSIONS: Increased endogenous oxalate production may occur in patients receiving long-term TPN.

Absorption↗
PubMed1995

Metabolic alterations of zinc and prostaglandins in both human and animal colonic tumor cells.

OBJECTIVE: To understand the relationship between zinc and prostaglandin (PG) metabolisms in inducing colon cancer incidence in human and animals. METHODS: Human colonic tumor and normal cells were obtained from Departments of Surgery and Pathology at the Kaiser Permanente Medical Center, Los Angeles, CA and US VA Medical Center, North Hills, CA. Rat colonic tumor and normal cells were isolated from the rats that received two injections of 50 mg/kg of Azoxymethan (AOM) in 2 weeks and then kept 30 weeks in the animal facility. Then, the effects of zinc on the PGE2 synthesis and PGE2 on zinc metabolism in tumor and normal cells were determined. RESULTS: PGE2 concentrations in both human and AOM-induced rat colonic tumor cells increased compared to those in adjacent normal colonocytes, whereas PGF2 alpha concentrations did not change. Gene expression of inducible form of prostaglandin synthase (PGS-2) is stimulated in rat colonocytes by epidermal growth factor and by tetradecanoyl 13-phorbol acetate (a tumor promoter and mitogen) only in the presence of zinc. PGE2 binding activity of rat enterocytes was maximum at 15 microM of zinc (normal plasma zinc concentration), but PGE2 synthesis activity increased for the first 15 minutes when extracellular zinc concentrations were either higher or lower than the normal extracellular zinc concentration. However, variations in extracellular zinc concentrations did not change the rate of PGF2 alpha synthesis in the normal rat enterocytes. PGE2 significantly increased zinc uptake rates of colonic tumor cells but PGF2 alpha showed only moderate effect. CONCLUSIONS: These results suggest that zinc is required for PGS-2 gene expression, that maintaining an optimal zinc nutriture is important for normal PG synthesis of intestinal cells, and that only PGE2 synthesis mechanisms rather than PGS-2 gene expression are altered in colonic tumor cells resulting in the abnormal zinc nutriture of these cells.

Animals↗
PubMed1995

Intestinal immune function is unaffected by parenteral nutrition in man.

BACKGROUND: Animal studies have demonstrated intestinal immunoglobulin production is decreased when luminal nutrition is withheld and nutrition is provided solely on the basis of total parenteral nutrition (TPN). METHODS: Eight normal volunteers were hospitalized in the Clinical Research Center for three weeks. The subjects received TPN as an exclusive means of nutritional support for 14 days followed by 5 days of enteral feeding with either standard or a glutamine- and arginine-supplemented formula in which the protein source was primarily free amino acids and peptides. Endoscopic jejunal biopsies obtained before and after TPN and following enteral refeeding were evaluated by immunofluorescence for the number of IgA, IgM and IgG-producing cells; T and B cells as well as intraepithelial and lamina propria lymphocytes were also counted. Serum immunoglobulins and the molecular forms of serum IgA were determined at the same intervals. RESULTS: The number of intestinal IgA-, IgM- and IgG-producing cells was unaffected by TPN (676 +/- 58 vs. 643 +/- 38, 101 +/- 14 vs. 98 +/- 18, 10 +/- 1 vs. 11 +/- 2 per low power field). The total number of intestinal lymphocytes, and CD3+ lymphocytes in the intraepithelial area was unaffected by TPN (10.4 +/- 0.4 vs. 10.2 +/- 1.3, 7.3 +/- 0.8 vs. 8.6 +/- 1.6 per 100 epithelial cells). Similarly, the total number of lymphocytes and CD3+ lymphocytes in the intestinal lamina propria was unaffected by TPN (4.4 +/- 0.2 vs. 6.2 +/- 0.8, 3.3 +/- 0.7 vs. 4.5 +/- 0.8). A small, but statistically significant increase in serum IgA and IgM was seen with TPN 314 +/- 11 vs. 342 +/- 16 mg/dL and 154 +/- 25 vs. 226 +/- 47 mg/dL, although IgG remained unchanged (1262 +/- 69 vs. 1207 +/- 57 mg/dL). The proportion of polymeric and monomeric serum IgA remained unchanged after TPN (19.2 vs. 22.1% polymeric). CONCLUSIONS: The use of TPN is not associated with intestinal immune dysfunction in man. A small, but statistically significant increase in serum IgM, and a borderline statistically significant increase in serum IgM were associated with TPN. The etiology and clinical significance of these observations is unclear.

Adult↗
PubMed1995

The treatment of intractable rejection with tacrolimus (FK506) in pediatric liver transplant recipients.

We report our experience in 17 pediatric orthotopic liver transplant (OLT) patients converted from cyclosporine (CsA) to FK506 for intractable acute and chronic rejection. FK506 was initiated orally at a dose of 0.3 mg/kg/day in most patients; the dose was then adjusted to achieve serum levels of 0.5-1.5 ng/ml. Azathioprine was discontinued and low-dose prednisone maintained. The median time between liver transplantation and FK506 conversion was 41 months. Patients have been treated for an average of 14.8 +/- 9.6 months. Six patients were converted for acute rejection and 11 for chronic rejection, i.e., vanishing bile duct syndrome (VBDS). After FK506 conversion, the actual patient and graft survival was 88% and 82%, respectively, in the group as a whole. Two patients died, one of chronic active hepatitis C and the other of lymphoma. Three patients, all with VBDS, did not respond to FK506 and therefore required retransplantation. The serum bilirubin is currently normal in 14 patients and the serum transaminases < 100 IU/ml in 12. The mean bilirubin pre-FK506 of patients successfully converted to FK506 was 4.2 mg/dl compared to 11.8 mg/dl in patients who failed conversion. Major complications included nephrotoxicity, neurotoxicity, and lymphoma. The mean glomerular filtration rate (GFR) of 97 +/- 29 mls/min/1.73m2 prior to FK506 conversion dropped to 51 +/- 20 mls/min/1.73m2 (p = 0.0001) after a mean of 13.6 months of FK506 therapy. Three patients have developed B-cell lymphomas; two of them responded to decreased immunosuppression and one died. We conclude that intractable liver graft rejection in children is most successfully reversed if FK506 is instituted before cholestasis becomes pronounced.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1995

Choline deficiency: a cause of hepatic steatosis during parenteral nutrition that can be reversed with intravenous choline supplementation.

Patients receiving long-term total parenteral nutrition (TPN) develop hepatic steatosis as a complication. Our previous studies have shown this to be caused, at least in part, by choline deficiency. We studied four patients (1 man, 3 women) aged 50 +/- 13 years who had low plasma-free choline concentrations 4.8 +/- 1.7 (normal, 11.4 +/- 3.7 nmol/mL). The patients had received TPN for 9.7 +/- 4.7 years. They received parenteral nutrition solutions containing choline chloride (1 to 4 g/d) for 6 weeks. Abdominal computed tomography (CT) was performed at baseline, biweekly during the choline supplementation, and 4 weeks after discontinuation of choline. During choline administration, the plasma-free choline concentration increased into the normal range within 1 week in all four patients and remained at or above the normal range for all 6 weeks, but decreased back to baseline when choline supplementation was discontinued. Hepatic steatosis resolved completely, as estimated by CT. Liver density increased from -14.2 +/- 22.3 Hounsfield units (HU) to 8.4 +/- 10.3 HU at week 2 (P = .002); 9.6 +/- 10.7 HU at week 4 and 13.1 +/- 7.3 HU at week 6, as determined by the liver-spleen CT number difference obtained by the subtraction of the average spleen CT number (in HU) from the average liver CT number. This improvement continued up to 4 weeks after choline supplementation (13.8 +/- 2.8 HU). Hepatic steatosis was shown to have recurred in one patient after 10 weeks of return to choline-free parenteral nutrition. The hepatic steatosis associated with parenteral nutrition can be ameliorated, and possibly prevented, with choline supplementation. Therefore, choline may be an essential nutrient for patients who require long-term parenteral nutrition.

Adult↗
PubMed1995

Diagnosis of coeliac sprue in 1994.

The first accurate clinical description of coeliac sprue was made more than a century ago. This disease entity could be defined and objectively diagnosed only after its relationship to gluten intake was discovered and jejunal biopsy techniques were developed to demonstrate the typical "flat" small intestinal mucosa. Since then clinical and histopathologic improvement on gluten-free diet has remained a cornerstone for the diagnosis of coeliac sprue; however, controversies regarding the diagnostic criteria had existed. This article presents the clinical features and the major categories of investigation for the diagnosis of coeliac sprue.

Antibodies↗
PubMed1994

Reversal of megaduodenum and duodenal dysmotility associated with improvement in nutritional status in primary anorexia nervosa.

Anorexia nervosa is considered one type of eating disorder that may result in severe malnutrition. Patients with this disorder commonly complain of postprandial nausea, abdominal pain, and distension. We describe the radiologic and motility abnormalities associated with anorexia nervosa in a 21-year-old female. Barium gastrointestinal series demonstrated marked dilation of the duodenum, with prolongation of intestinal transit. A 4-hr fasting gastroduodenal motility study showed no propagating migrating motor complexes (MMC). Prolonged, but nonpropagating, bursts of high-amplitude phasic and tonic contractions were seen in the duodenum. In contrast, antral contractions were of low amplitude and esophageal motor function was normal. Metoclopramide and edrophonium caused an increase in gastroduodenal motor activity, but increased contractions were not associated with symptoms. Following a renutrition program that raised the patient's weight from 64 to 80% of her ideal body weight, the radiographic abnormalities and gastrointestinal dysmotility resolved completely. These observations suggest that anorexia-associated gastrointestinal motor dysfunctions are a consequence, not the cause of the generalized protein-calorie malnutrition associated with anorexia nervosa. The facts that motility in different parts of the gut is affected to different degrees and that gastric and duodenal muscle responds normally to exogenous stimulation argue against a generalized myogenic dysfunction and, rather, point to a reversible dysfunction of neural regulation.

Adult↗
PubMed1994

230 patient years of experience with home long-term parenteral nutrition in childhood: natural history and life of central venous catheters.

The records of 27 pediatric patients who required parenteral nutrition (PN) for 5 to 14.5 years (mean +/- SD, 8.5 +/- 3.8) were analyzed to determine the frequency of complications with their central venous catheters (CVC). This represents a 230 patient-year experience. Patients with short bowel syndrome and chronic intestinal pseudoobstruction syndrome (CIPS) accounted for all but two of the patients. Unsuccessful medical management of the exit site or CVC infection was responsible for removal of 62% of the 123 CVCs. Ninety-five episodes of line infection occurred in 24 patients. Fifty (52%) were successfully treated without catheter removal. The organisms responsible for catheter removal were fungal (14), mycobacterium species (5), gram-positive cocci (22), or gram-negative bacilli (19). The CVCs were infected an average of once every 884 days. The life of the second CVC (23.5 +/- 17.9 months) was significantly longer than that of the first (P < .05). Clotting of the CVC with unsuccessful lysis of the clot was responsible for removal of 24%, and breakage or unsuccessful repair was responsible for 14%. In no patient were all possible venous sites for CVC placement exhausted. Patients with CIPS had substantially fewer catheter complications (P < .05) than did those with short bowel syndrome. In conclusion, CVCs can "survive" without major complications for more than a decade. Numerous factors contribute to the increased rate of CVC survival over time, including improvement in PN self-care with greater experience, improvement in teaching, regular follow-up of patients, better management of infection, and better ability to treat CVC thrombosis or breakage.

Adolescent↗
PubMed1994

Choline pharmacokinetics during intermittent intravenous choline infusion in human subjects.

A study of choline pharmacokinetics was undertaken in four patients receiving long-term total parenteral nutrition. On consecutive days, 7, 14, 28, and 56 mmol choline chloride were intravenously infused over a 12-hour period in each subject. The choline concentration was determined in plasma at baseline, 1/4, 1, 3, 6, and 12 hours, and 3 and 12 hours after the infusion ended, and in daily 24-hour urine collections. Analysis of variance showed the data fit a two-compartment model in which elimination from the central compartment was saturable significantly better than a one-compartment model in all four subjects (p < 10(-8) in all cases), and significantly better than a nonsaturating model in three of the four subjects (p = 1.0 x 10(-9), 7.5 x 10(-6), 9.4 x 10(-11), respectively). The model allowed estimates of the rate constant for choline elimination at ambient levels, first-order rate constants for transfer between central and peripheral compartments, the dissociation constant for the saturable elimination process, the apparent volume of distribution in the central compartment, the steady-state volume of distribution, and the quantities of choline in the central compartment and in the readily exchangeable pool.

Adult↗
PubMed1994

Medical therapy for ulcerative colitis in childhood.

Corticosteroids remain the primary therapeutic agent to induce remission in moderate to severe ulcerative colitis (UC) and Crohn's disease because of their rapidity of action in comparison to other agents. Mild UC and/or Crohn's disease of the colon and terminal small bowel may be treated with azulfidine first. However, if patients are intolerant of these medications, dipentum or asacol may be used. Occasionally, patients with Crohn's colitis but not UC may respond to metronidazole. Immunosuppressive agents such as 6-mercaptopurine are very useful for steroid-dependent inflammatory bowel disease, as a substitute for long-term corticosteroids. Cyclosporine, although it has been proposed as an alternative to other antimetabolite or immunosuppressive therapy, is of benefit in fewer than 25% of cases of UC or Crohn's disease. Rowasa enemas are useful for left-sided disease in UC or Crohn's disease of the colon; however, use in children may be difficult in view of psychosocial issues that must be considered.

Adrenal Cortex Hormones↗