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Biomedical subjects

J N Udall

Publications and source records attributed to J N Udall.

At least 37 records · Page 2Linked to original sources
PubMed1996

Secretory diarrhea in children: newly recognized toxins and hormone-secreting tumors.

This review of bacterial toxins and hormones that stimulate diarrhea shows that we have learned much concerning the pathophysiology of these diarrheal states; however, we have much yet to learn. It is hoped that research will continue to enlighten us with regard to the pathophysiology, diagnosis, and treatment for these disease processes.

Bacterial Infections↗
PubMed1996

Neonatal gastrointestinal mucosal immunity.

The gastrointestinal mucosal immune system is a complex system with multiple interacting cells, which express different markers and elaborate a variety of mediators in response to noxious stimuli and pathogens. At birth this system is quite immature, putting the newborn mammal at risk for a variety of infectious and noninfectious diseases. With age and antigenic stimulation, maturation occurs and intestinal host defense then functions quite effectively to protect the host from ingested noxious substances and microorganisms.

Aging↗
PubMed1992

Vitamin update.

Explore the source record for details and available documents.

Anorexia↗
PubMed1992

Treatment of infants with acute diarrhea: what's recommended and what's practiced.

In 1985, the American Academy of Pediatrics (AAP) published a policy statement on the treatment of infants with acute diarrhea complicated by mild to moderate dehydration. To determine how closely physicians in the United States follow the AAP's treatment guidelines, a questionnaire was sent to 457 pediatricians and 360 family practitioners. The questionnaire presented a hypothetical infant with acute diarrhea complicated by mild to moderate dehydration and included questions regarding the number of such patients seen yearly, length of time used to rehydrate the infant, and how formula or solids are introduced following rehydration. Complete responses were received from 53% of pediatricians and 40% of family practitioners. The number of patients with acute diarrhea seen per year did not affect physician's treatment. Pediatricians and family practitioners responded similarly to most questions. Contrary to the AAP's guidelines to rehydrate in 4 to 6 hours, 62% of responding physicians extend the rehydration period to 12 to 24 hours. Also contrary to the AAP's recommendations, 62% of pediatricians and family practitioners use a lactose-free formula. The majority of responding physicians do follow the AAP's treatment guidelines to initiate feedings with diluted formula. Significantly more pediatricians than family practitioners advance to a full-strength formula within 1 day (P = .011). Fewer than 50% of physicians polled started solids within 24 hours as suggested by the AAP. Overall, the findings suggest that very few pediatricians and family practitioners follow all aspects of the AAP's treatment guidelines for infants with acute diarrhea complicated by mild to moderate dehydration.

Acute Disease↗
PubMed1991

Calcified thrombus in the right atrium: a rare complication of long-term parenteral nutrition in a child.

A 5-year-old boy with short-bowel syndrome who receives home parenteral nutrition developed a calcified thrombus that involved the inferior vena cava (IVC) and the right atrium. Symptoms included 3 to 4 months of intermittent fever and 2 months of vague chest pain. Blood could not be aspirated from the IVC catheter and an IVC contrast study demonstrated the calcified thrombus. The intracardiac portion of the mass was removed surgically, but the IVC mass could not be completely excised. The boy developed a pericardial effusion 6 weeks after surgery. He was treated for this and 6 months after the initial surgery the patient was asymptomatic.

Calcinosis↗
PubMed1991

Lovastatin therapy for cholesterol ester storage disease in two sisters.

We administered lovastatin to two sisters, aged 4 and 17 years, who had cholesterol ester storage disease, an autosomal recessive disorder manifested by hypercholesterolemia and hypertriglyceridemia. The drug, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, was taken orally for 6 months. Serum lipid concentrations were determined monthly. Computed tomography of the liver was performed before and during therapy to evaluate liver fat content. The younger sister had liver biopsies before and after 6 months of lovastatin therapy to assess hepatic cholesterol stores. Both patients had marked decreases in serum levels of cholesterol, triglycerides, and low-density lipoprotein-cholesterol; high-density lipoprotein-cholesterol levels increased. Computed tomography during treatment demonstrated a significant increase in linear attenuation, suggesting a decreased liver fat content. Liver tissue obtained 6 months after lovastatin therapy was initiated had 13% less esterified cholesterol than the liver sample obtained before treatment. We conclude that lovastatin may be effective in treating children with cholesterol ester storage disease.

Adolescent↗
PubMed1990

Intestinal permeability to intact lactose in newborns and adults.

Small amounts of lactose have been shown to be absorbed intact across the intestine and excreted unchanged in the urine of newborns and adults. We designed a study to quantitate the intestinal uptake and urinary excretion of this disaccharide in these age groups. Similar amounts of lactose were given orally to 17 term newborns (age: 24.8 +/- 3.0 h) as a standard infant formula, and to 15 adult lactose absorbers (age: 28.1 +/- 2.6 years) and 11 adult lactose malabsorbers (age: 24.7 +/- 2.9 years) as a 20% water solution. Following lactose ingestion, breath was collected every 30 or 60 min for 3 h and analyzed for hydrogen concentration. Urine was also collected, and lactose and creatinine concentrations were determined. Peak hydrogen concentration was less than 20 ppm above baseline in newborns and adult lactose absorbers and 85 +/- 14 ppm in adult lactose malabsorbers. Urinary lactose excretion, expressed as a function of body weight (mg/ml/kg b.w.), was substantially greater in newborns (4.2 +/- 0.82) than in adult lactose absorbers (0.29 +/- 0.07; p less than 0.001) and adult lactose malabsorbers (0.55 +/- 0.04; p less than 0.01). Similarly, urinary lactose excretion expressed as a ratio of urinary lactose to urinary creatinine (mg/mg) was increased (p less than 0.001) in newborns (2.05 +/- 0.26) when compared to adult lactose absorbers (0.11 +/- 0.02) and adult lactose malabsorbers (0.20 +/- 0.02). Our data demonstrate that the intestinal uptake and urinary excretion of intact lactose is significantly increased in newborns compared to adult subjects.

Adult↗
PubMed1989

Assessment of lactose absorption by measurement of urinary galactose.

Individuals with sufficient intestinal lactase hydrolyze ingested lactose to galactose and glucose and these monosaccharides are absorbed. Lactose is not digested completely when intestinal lactase activity is low and the disaccharide is malabsorbed. Breath hydrogen excretion after lactose ingestion is used commonly to diagnose lactose malabsorption. However, no direct tests are currently used to assess lactose absorption. We tested a new method of assessing lactose absorption in 26 healthy individuals. Each subject ingested 50 g of lactose. Participants were evaluated for lactose malabsorption using a standard 3-h breath hydrogen test. In addition, the urinary excretions of galactose, lactose, and creatinine were quantitated for 3-5 h after lactose ingestion. On the basis of breath hydrogen analysis after lactose ingestion, 12 individuals were lactose malabsorbers (defined as a rise in the breath hydrogen concentration of greater than 20 parts per million above the baseline value). The 14 subjects who did not malabsorb lactose by breath hydrogen testing (defined as a rise in the breath hydrogen concentration of less than or equal to 20 parts per million above the baseline value), had significantly more galactose in their urine 1, 2, and 3 h after lactose ingestion than lactose malabsorbers. The ratio of excreted lactose to excreted galactose was significantly decreased in lactose absorbers compared with lactose malabsorbers (p less than 0.001). Determination of the ratio of urinary galactose to urinary creatinine separated lactose absorbers from lactose malabsorbers completely (p less than 0.001). We conclude from this study that the determination of urinary galactose, urinary lactose/galactose ratio, and urinary galactose/creatinine ratio may be used to assess lactose digestion and absorption in healthy adults.

Adolescent↗
PubMed1989

Nutritional support for pediatric patients with inflammatory bowel disease.

Pediatric patients with ulcerative colitis and Crohn's disease often suffer from malnutrition and growth failure. This is particularly true in pubertal children. Chronic insufficient nutrient intake is most often the cause of growth failure. Both parenteral nutrition and defined enteral formulas are available to rehabilitate patients with malnutrition and growth failure. Assessment of nutritional status and growth and the use of parenteral nutrition and defined enteral formulas to reverse malnutrition, growth failure, and inflammation in pediatric patients with inflammatory bowel disease are discussed.

Adolescent↗
PubMed1989

Minimal hydrolysis of epidermal growth factor by gastric fluid of preterm infants.

Epidermal growth factor (EGF), present in high concentrations in milk, may play a role in growth of the gastrointestinal tract. Resistance to proteolytic degradation in the stomach is necessary if ingested EGF is to function within the gastrointestinal tract. Although EGF stability to low pH and proteases predicts gastric survival, the extent of digestion in the stomach remains to be defined. Consequently, we measured gastric degradation of 125I-human recombinant EGF in preterm infants with an in vitro method in which EGF was incubated at 37 degrees C with stomach fluid at pH 1.8, 3.2, and 5.8 followed by analysis of degradation products. As maximal acid proteolytic activity is present one hour after feeding in preterm infants, fluid was obtained at that time from 18 infants with a mean gestational age at birth of 30.4 (3.0) (SD) weeks and a postnatal age of 26.3 (12.7) days at sampling. Incubations for up to 60 minutes revealed minimal loss of trichloroacetic acid precipitable radioactivity, in contrast to the substantial hydrolysis of iodinated casein which occurred under the same conditions. Chromatography of reaction mixtures on Sephadex G-25 showed a single major peak of radioactivity which coeluted with EGF. Epidermal growth factor also retained greater than 75% of its ability to bind to anti-EGF affinity columns and placental membrane receptors after incubation with gastric fluid. These data support the concept of substantial gastric survival of ingested EGF in a potentially biologically active form in preterm infants.

Epidermal Growth Factor↗