Search PubMed⌕ Search

Biomedical subjects

D L Antonson

Publications and source records attributed to D L Antonson.

At least 37 records · Page 2Linked to original sources
PubMed1986

Effects of isolated zinc deficiency on the composition of skeletal muscle, liver and bone during growth in rats.

We investigated the effects of zinc deficiency on body composition by using intragastric force-feeding to obviate decreased food intake and altered eating patterns. Weanling male Sprague-Dawley rats were fed a purified zinc-deficient diet: the ad libitum-fed control group (AL; eight rats) was given powdered diet and water containing 25 ppm zinc; the zinc-replete group (ZN; nine rats) was force-fed a diet blended with water containing zinc in an amount of equal caloric intake to the AL group and allowed access to water containing zinc. The zinc intake of ZN rats was approximately twice that of AL rats based on water intake. The zinc-deficient group (ZD; 13 rats) was fed similarly to the ZN group except deionized water was used for diet preparation and drinking water. After 8 d, body and muscle weight were lower in the ZD group than in the ZN group. Femur weights were similar in the two groups. Serum, liver and femur zinc concentrations were 85, 22 and 42% lower, respectively, in the ZD group than in the ZN group. Serum glucose, relative liver weight, liver glycogen and liver lipids were higher, but muscle and liver DNA were lower in the ZD group than in control groups.

Animals↗
PubMed1985

Intestinal tapering and lengthening for short bowel syndrome.

Intestinal tapering and lengthening were performed in a child with short bowel syndrome to prevent the need for home parenteral nutrition. The intestinal lengthening was not successful, presumably because the vascular anatomy was not favorable. Significant clinical improvement and avoidance of home parenteral nutrition resulted from the tapering procedure. These procedures have a role in the treatment of selected patients with short bowel syndrome.

Female↗
PubMed1985

Effects of short-term isolated zinc deficiency on intestinal growth and activities of several brush border enzymes in weaning rats.

To determine whether zinc has a specific role on intestinal growth and function, three groups of male weanling Sprague-Dawley rats were fed a semipurified zinc-deficient diet: ad libitum fed group received powdered diet and water containing 25 ppm of zinc; force fed (ZN, ZD) groups were fed identical amounts of diet to the ad libitum fed group by intragastric infusion three times per day. The diets were aqueous suspensions made with either deionized water (ZD) or water containing 25 ppm of zinc (ZN), and additional drinking water with (ZN) or without zinc (ZD) was offered ad libitum. Rats were sacrificed after 8 days of feeding. The ZD group showed growth arrest, perioral and periorbital dermal lesions, and abdominal distention within 8 days of feeding. Mucosal DNA, protein, sucrase, maltase, lactase, leucine aminopeptidase, and alkaline phosphatase were significantly decreased in the ZD group, whereas intestinal length, weight, and mucosal weight were unaltered. These results suggest that short-term isolated zinc deficiency impairs growth, digestion, and absorption in the rat small intestine, even in the absence of associated protein calorie malnutrition.

Alkaline Phosphatase↗
PubMed1984

Comparison of techniques for growing small bowel neomucosa.

Small bowel neomucosa has been grown on a variety of surfaces. The purpose of this study was to compare the rate of growth and function of neomucosa on colon serosa (CS) and abdominal wall muscle (AM) in New Zealand white rabbits. The terminal ileum was incised for 5 cm and patched with either adjacent CS (23 animals) or AM (19 animals) to create a 2 X 5-cm defect. Gross and histologic examinations of the specimens at 1, 2, 4, and 8 weeks revealed that the rate of growth was similar in both groups. There was minimal lateral ingrowth at 2 weeks, nearly complete coverage of the defects at 4 weeks, and complete coverage of the defect at 8 weeks in more than 85% of animals with mature villi and muscularis mucosae. The ileal diameter at the site of patching increased in both groups from 11.9 +/- 2.6 to 16.3 +/- 3.2 mm in the CS group and 11.3 +/- 2.5 to 15.1 +/- 1.8 mm in the AM group (P less than 0.01). Glucose uptake was similar in both groups being 65.4 +/- 24.1% of control in the CS group and 73.9 +/- 29.8% in the AM group. Brush border enzyme activity of sucrase, maltase, and lactase was similar to controls in the AM group but in the CS group activity of sucrase and maltase were significantly less than controls (P less than 0.01). Average body weight was increased postoperatively in both groups. There was one anastomotic leak in each group and two cases of partial intestinal obstruction in the abdominal wall group.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Muscles↗
PubMed1984

Effect of casein versus casein hydrolysate on mucosal adaptation following massive bowel resection in infant rats.

Little is known concerning the effects of elemental diets on bowel adaptation following massive resection. Fourteen of 28 Sprague-Dawley rats (40-45 g) were subjected to a 60% jejunoileal resection. Seven of the resected animals and seven sham-operated controls were then placed on a diet containing all protein in the form of casein hydrolysate. The remaining seven resected animals and seven sham-operated controls were placed on a comparable diet in which all the protein was casein. Each control animal was paired with a resected animal. After 2 weeks, unidirectional glucose and leucine transport was determined from intestinal sacs made from the proximal 3 cm and distal 3 cm of the remaining bowel. The midportion was used for the determination of mucosal weight and protein and sucrase content. When expressed as a percent increase over control values per centimeter of bowel, only sucrase levels were significantly elevated in the distal bowel in casein hydrolysate-versus casein-fed animals. The mucosal protein level, mucosal weight, and glucose uptake did not differ from control values when expressed as a percent change. Leucine uptake was significantly decreased in casein hydrolysate-fed animals when compared to that in casein-fed animals in both the proximal and distal bowel, again when expressed as a percent change from the control values. The administration of protein in the form of casein hydrolysate following massive bowel resection does not adversely affect mucosal hyperplasia occurring after resection but may have an adverse effect on the enhancement of amino acid absorption.

Adaptation, Physiological↗
PubMed1983

Effect of chronic ethanol ingestion on zinc absorption in rat small intestine.

The effect of chronic ethanol ingestion on the ability of the small intestine to absorb zinc was examined in male Sprague-Dawley rats. Six rats were fed the Lieber-Decarli liquid rat diet for 1 month during which 36% of their total calories were provided as ethanol, while their pair fed controls received these calories as carbohydrate. Zinc absorption was then examined simultaneously in duodenal and ileal segments by in vivo perfusion. Net absorption of zinc in the ileum was reduced by 16% following chronic ethanol feeding. Duodenal absorption of zinc was significantly less than in the ileum and was unaffected by chronic ethanol ingestion. These results demonstrate that chronic ethanol ingestion significantly impairs net zinc absorption in the ileum of the rat, the most active area of zinc uptake as measured by in vivo perfusion, and suggest that malabsorption of zinc may contribute to the zinc deficiency seen following chronic ethanol ingestion.

Animals↗
PubMed1983

Hair and plasma zinc levels following exclusion of biliopancreatic secretions from functioning gastrointestinal tract in humans.

Pancreatic secretions have been shown to be important in zinc absorption in experimental animals. Recently, complete surgical diversion of biliary and pancreatic secretions from the functioning small intestine has been utilized in Europe to treat morbid obesity. To determine the importance of pancreatic secretions in zinc absorption in the human, we measured hair and serum zinc levels in 14 patients having undergone complete biliopancreatic bypass 12-56 months earlier and compared these values with those obtained from 11 patients subjected to only partial biliopancreatic bypass as well as to six morbidly obese controls. No differences were observed in either hair or serum zinc levels between any of these groups of patients. Pancreatic secretions do not appear to be necessary for adequate zinc absorption in humans.

Adult↗
PubMed1983

Stability of vitamin and mineral concentrations of a low-birth-weight infant formula during continuous enteral feeding.

The stability of several vitamins and minerals of a new formula for premature infants, Similac Special Care, was examined following passage through a simulated continuous infusion apparatus designed to duplicate that used for continuous enteral feeding in infants. The concentrations of calcium, iron, zinc, copper, magnesium, vitamin A, vitamin C, and vitamin E were measured before and after infusion at rates appropriate for delivering 120 calories/kg to infants weighing 733 and 1,000 g. Following passage through this apparatus, significant reductions were noted for calcium (44-54%), iron (23-34%), and zinc (18-32%). Concentrations of copper, magnesium, and vitamins A, C, and E remained stable. When another formula commonly used for premature infants, Similac 24LBW, was subjected to similar analysis, the concentrations of all vitamins and minerals studied remained stable. Our study demonstrates that infants fed Similac Special Care by continuous infusion may not receive the quantity of calcium, iron, and zinc implied by the product label.

Calcium↗
PubMed1983

Potential for mucosal adaptation following massive small bowel resection in 3-week-old versus 8-week-old rats.

In order to determine the relative capacity for bowel adaptation in young versus older rats, 60% bowel resections were performed in seven 3-week-old and seven 8-week-old rats. These animals were then pair-fed with control animals that had undergone sham operations, and after 2 weeks, all animals were killed. Segments of remaining jejunum, midileum, and distal ileum were removed, and mucosa was scraped free using a glass slide. Mucosal wet weight, protein, RNA, DNA, and sucrase content were measured. Data were expressed as percent increase of each mucosal parameter in resected as opposed to control animals, and the two age groups were compared by unpaired t test. When data were examined per centimeter of bowel, increases in all parameters in each segment were substantially greater in the older animals, suggesting that older animals have a greater capacity for mucosal adaptation following massive bowel resection than do young animals. These findings correlate well with clinical experience which suggests that infants with massive bowel resection may require years of parenteral nutrition before total enteral nutrition is possible.

Adaptation, Physiological↗
PubMed1983

Bilateral Toxocara optic neuropathy.

A 14-year-old girl had loss of vision in the right eye and bilateral optic disc swelling. After treatment with oral prednisone, the neuropathy resolved. An extensive evaluation led to a probable diagnosis of Toxocara optic neuropathy.

Adolescent↗
PubMed1982

Osmolality of carbohydrate solutions and gastric emptying in the newborn.

Gastric emptying in normal newborns was studied with use of a double marker technique. The volume of 200 to 400 mOsm carbohydrate solutions emptied from the stomach in 30 minutes was determined. To evaluate isocaloric solutions of different osmolalities, the osmolality of a 400-mOsm glucose solution was decreased to 300 and 200 mOsm/L by replacing a portion of the glucose with glucose oligosaccharides (GOSs). Because GOSs could be rapidly hydrolyzed in the duodenum, the effect of osmolality alone was studied by adding xylose to a 200-mOsm glucose solution to increase the osmolality to 300 and 400 mOsm/L. The volumes of the various solutions emptied in 30 minutes were not significantly different. These findings suggest that decreasing formula osmolality from 400 to 200 mOsm offers no intrinsic advantage with regard to gastric emptying.

Carbohydrates↗
PubMed1982

Zinc absorption following massive small-bowel resection in the rat.

Zinc absorption was evaluated six weeks after massive small-bowel resection in rats. Forty rats were divided into four groups. Ten were subjected to proximal small-bowel resection, 10 to distal resection, and 20 served as pair-fed controls. Intestinal perfusion studies were performed using a recirculation technique. Twenty ml of a solution containing 10 microgram/ml of zinc as zinc sulfate, isotonic sodium chloride, and polyethylene glycol 5 g/liter was perfused for 2 hr through 10 cm of remaining bowel in resected animals and comparable segments in control animals. Zinc uptake was determined and expressed per 0.1 g mucosal dry weight. In control animals, zinc absorption was greatest in the ileum. Animals undergoing distal bowel resection had a compensatory increase in zinc absorption in the proximal small intestine. However, animals undergoing proximal resection did not demonstrate an increase in zinc absorption in the distal bowel. The proximal small intestine appears capable of increasing its capacity for zinc absorption in the response to distal small-bowel resection.

Animals↗
PubMed1982

Effect of antibiotics in the prevention of jejunoileal bypass-induced liver dysfunction.

Administration of antibiotics has been reported to prevent or minimize liver dysfunction in experimental animals having been subjected to jejunoileal bypass, suggesting that jejunoileal bypass-induced liver dysfunction results from production of toxic substances by bacteria in the defunctionalized bowel. However, improved absorption will also prevent bypass-induced liver injury. We studied the effects of tetracycline on the development of bypass-induced liver dysfunction and compared it to the mucosal adaptation of the intact bowel after bypass. After 6 weeks, rats subjected to bypass but not given antibiotics had decreased levels of serum triglycerides, hepatic cytochrome P-450, and hepatic pentobarbital hydroxylase. Evaluation of intestinal mucosal hyperplasia after bypass indicated that animals given antibiotics after bypass developed greater increases in mucosal DNA content, mucosal protein, and mucosal weight than bypassed animals not receiving antibiotics. We speculate that the beneficial effects of antibiotic administration on liver function after bypass may be a result of improved absorption.

Animals↗
PubMed1982

Continuous enteral feedings. An important adjunct to the management of complex congenital heart disease.

Eleven infants with complex congenital heart lesions were given continuous enteral infusions after failure to gain weight adequately despite use of hypercaloric formulas and nutritional supplementation. Formulas used before institution of enteral feedings were continued. Dietary and caloric intake and weight measurements were obtained at weekly or monthly intervals. Both mean daily caloric intake and mean daily weight gain were greater after initiation of continuous enteral feedings. Rate of weight gain improved in all 11 children after institution of enteral feedings. Continuous enteral feeding increases weight gain in babies with complex congenital heart disease, allowing earlier and safer surgical intervention.

Body Weight↗
PubMed1981

Etiology of jejunoileal bypass-induced liver dysfunction in rats.

Several recent studies suggest that jejunoileal bypass-induced liver disease results from malabsorption of essential nutrients. However, in experimental animals, resection of the defunctionalized bowel substantially reduces bypass-induced liver injury. Such models are often used to support the theory that bacteria in the defunctionalized bowel produce toxic substances which result in liver damage. We used a rat model to first explore the effects of intestinal bypass vs resection on various parameters of liver injury, and subsequently compared these findings to the effect of both bypass and resection on mucosal adaptation in the remaining intact bowel after each procedure. Bypassed animals had lower levels of hepatic cytochrome P-450, glucose-6-phosphatase, pentobarbital hydroxylase, and serum triglycerides than did animals undergoing resection of defunctionalized bowel. Concurrently, resected animals had much greater increases in mucosal weight, DNA content, and protein content in the intact bowel than did bypassed animals. We speculate that the beneficial effects of resection of bypassed bowel on liver function may be a result of increased mucosal hyperplasia in resected animals, rather than elimination of production of toxic substances in the defunctionalized bowel.

Animals↗