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Biomedical subjects

M K Foley

Publications and source records attributed to M K Foley.

12 recordsLinked to original sources

School-based management of the child with an acute asthma episode.

Asthma is a chronic inflammatory disorder of the airways that affects 5 million American children. In the past decade, asthma morbidity has dramatically increased. This increase is particularly apparent in poor minority inner-city children. School-based health centers offer a conveniently located setting for the acute treatment and long-term management of childhood asthma. Treatment of asthma using the most recent management guidelines offered in a school setting should result in a decrease in the morbidity and mortality associated with pediatric asthma.

Anti-Asthmatic Agents↗

Extrinsic innervation modulates canine jejunal transport of glutamine, alanine, leucine, and glucose.

BACKGROUND: We previously showed a decrease in ileal glutamine transport in vitro and net absorption in vivo after extrinsic denervation of the canine jejunoileum. The aim was to determine whether extrinsic innervation modulates in vivo net absorption and in vitro transport of glutamine and other nutrients in canine jejunum. METHODS: In vivo net jejunal uptakes of glutamine, alanine, leucine, and glucose were measured in five dogs before and 2 and 8 weeks after a model neurally isolating in situ the jejunoileum (extrinsic denervation, intestinal transection). To assess mechanisms, carrier-mediated uptakes were quantitated in jejunal brush border membrane vesicles from six dogs before and at 2 and 8 weeks after neural isolation of the jejunoileum and compared with six control dogs with fully intact extrinsic innervation. RESULTS: In vivo net absorption of glutamine decreased at 2 weeks (p < 0.05) and returned to normal values at 8 weeks; net absorptions of leucine, alanine, and glucose were decreased at both 2 and 8 weeks. In vitro brush border membrane vesicles transport of glutamine, leucine, and alanine followed the patterns of in vivo absorption, but glucose transport did not differ at any time point. Decreased glutamine uptake at 2 weeks resulted from a decrease in Vmax rather than a change in K(m) in sodium-dependent carrier-mediated transport. CONCLUSIONS: Extrinsic denervation down-regulated carrier-mediated transport of amino acids but not glucose. Decreased in vitro glutamine transport was mediated in part by a decrease in number rather than affinity of sodium-dependent transporters.

Alanine↗

In situ neural isolation of the entire canine upper gut: effects on fasting and fed motility patterns.

BACKGROUND: Multiorgan upper gut transplantation is becoming clinically feasible; however, the effects of multivisceral transplantations on gastrointestinal motility are unknown. Our aim was to determine the neural and hormonal mechanisms controlling motility patterns after complete extrinsic denervation of the upper gut as a model of multivisceral upper gut autotransplantation. METHODS: Seven dogs successfully underwent in situ neural isolation of the stomach, entire small intestine, proximal colon, liver, and pancreas by transecting all connections (distal esophagus, midcolon, all nerves, lymphatics) to this multivisceral complex except the celiac artery, superior mesenteric artery, and the suprahepatic and infrahepatic vena cava; these vessels were meticulously stripped of adventitia under optical magnification. Blood flow was not disrupted to prevent confounding effects of ischemia-reperfusion injury. After 1- to 2-week recovery, myoelectric and manometric recordings of stomach and myoelectric recordings of small bowel were obtained from conscious animals. RESULTS: During fasting the characteristic cycling migrating motor complex (MMC) was observed in the stomach and small intestine. The gastric component of the MMC was absent in one of the seven dogs. Regular cycling of the MMC during fasting, however, was intermittently disrupted and replaced by a noncyclic pattern of intermittent contractions in two of seven dogs 43% of the recording time. A small meal (50 gm liver) did not abolish the MMC as occurs in normal dogs; in contrast, a large meal (500 gm liver) did abolish the MMC. CONCLUSIONS: Extrinsic innervation to the upper gut modulates but is not requisite for interdigestive and postprandial motility of the stomach. Because relatively normal global motility patterns are preserved, multivisceral upper gut transplantation should be a viable option in selected patients.

Animals↗

Role of extrinsic innervation in carbohydrate-induced ileal modulation of pancreatic secretion and upper gut function.

Previously we showed that carbohydrate (CHO) in the ileum slowed gastric emptying and increased pancreatic amylase secretion relative to that of other enzymes. Our aim here was to determine if extrinsic innervation of the jejunoileum participates in the CHO-induced ileal modulation of postprandial upper gut function. Six dogs were studied before and 2-3 weeks after in situ neural isolation of the jejunoileum (complete extrinsic denervation). Gastric emptying (GE) and pancreatic amylase secretion were quantitated for 4 h after a 300-ml meal containing 3H-PEH (liquid marker) and 99mTc sulfur colloid cooked with eggs (solid marker). Coincident with feeding, we started a distal ileal infusion of 150 mM NaCl or 40 mg.min-1 CHO. Extrinsic denervation abolished the slowing of GE of liquids and solids and the augmented increase in amylase and trypsin in relation to solid emptying seen in the neurally intact dogs prior to denervation. Denervation also abolished the decrease in total pancreatic exocrine secretion in response to ileal CHO. Increases in plasma concentrations of peptide YY (PYY) were correlated temporally with decreased GE of solids and increased exocrine secretion during ileal CHO in neurally intact dogs, but no increases in PYY release occurred after extrinsic denervation. Extrinsic denervation of the jejunoileum abolished the effect of ileal CHO on GE of liquids and solids, the decrease in total amylase secretion during ileal CHO, and the relative increase in enzyme secretion expressed as total enzyme output per percentage solid marker emptied. Extrinsic innervation of the jejunoileum mediates ileal modulation of GE and the relationship of amylase secretion to GE of solids. The mechanism of this effect may be via neurally mediated release of PYY.

Amylases↗

Role of the vagal branches to the proximal stomach in mediating gastric distention-induced disruption of canine interdigestive upper gut motility.

Previous experiments from our laboratory have shown that the vagus nerves mediate proximal gastric distention-induced disruption of interdigestive motor patterns in the upper gut of dogs. Our aim was to determine the role of vagal innervation of the proximal stomach in mediating the response to nonnutrient proximal gastric distention. Five dogs underwent proximal gastric vagotomy (PGV) and placement of electrodes and manometry catheters on the antrum and the upper small intestine. Proximal gastric distention for 5 hr was achieved by inflating a thin, compliant bag in the proximal stomach. Four volumes of distention stimulus (0, 1.5, 12.5, and 25 ml/kg) were tested. As with total abdominal vagotomy, intragastric stimulus volumes of 12.5 and 25 ml/kg after PGV no longer inhibited cycling of the migrating motor complex in the stomach, duodenum, proximal jejunum, and distal jejunum. Volumes of 12.5 and 25 ml/kg did, however, on occasion, lead to the absence of phase III activity in the stomach or the duodenum when it would have been expected to precede phase III activity in the jejunum; this effect did not occur in the jejunum. These findings with a nonnutrient stimulus suggest that vagal branches to the proximal stomach might mediate, in part, the postprandial changes in upper gut motility in response to gastric distention by ingestion of a meal.

Animals↗

A surgical model for studying biliary bile acid and cholesterol metabolism in swine.

Techniques were developed in young growing pigs to simultaneously collect and reinfuse bile. Silastic cannulae were designed and surgically implanted in the common bile duct and the duodenum. Direct sampling of the hepatic bile was achieved by bypassing the gallbladder. The techniques allowed for steady-state studies of hepatic function to be conducted in conscious swine in two different studies. Pigs, thus surgically modified, can serve as an appropriate model for physiologic, pharmacologic, and nutritional research that involves bile sampling.

Animals↗

Influence of dietary calcium and cholecalciferol on composition of plasma lipids in young pigs.

Young growing pigs were fed diets containing either 1 or 3 times the daily requirement of calcium and 1, 5 or 25 times the daily requirement of vitamin D (as cholecalciferol) in a completely randomized design with treatments in a 2 X 3 factorial arrangement. Excess dietary calcium increased the phospholipid concentration in the plasma, but not its partitioning among plasma lipoproteins. The level of dietary calcium had no effect on cholesterol, triacylglycerol or protein concentrations in plasma or their partitioning among plasma lipoproteins. Excess dietary calcium decreased body weight gains of pigs. The level of dietary cholecalciferol had no effect on body weight gain or on the concentrations of cholesterol, phospholipid, triacylglycerol or protein in plasma, or on their partitioning among plasma lipoproteins. Increased vitamin D intake resulted in increased plasma 25-hydroxycholecalciferol, whereas high dietary calcium decreased concentrations of 1,25-dihydroxy-vitamin D. Increased dietary calcium also increased plasma calcium concentrations of only plasma phospholipids and decreased growth rate, whereas excess dietary vitamin D had no effect on growth or lipid composition of plasma in growing pigs.

Animals↗

Effect of dietary fat source on lipoprotein composition and plasma lipid concentrations in pigs.

Most studies of the effects of dietary fat sources on plasma lipid components have used diets with extreme fat compositions; the current study was designed to more nearly mimic human dietary fat intake. Young growing pigs were fed diets containing either 20 or 40% of energy as soy oil, beef tallow or a 50/50 blend of soy oil and tallow. Different dietary fats did not affect concentrations of cholesterol, triacylglycerol or protein in plasma or major lipoprotein fractions. The concentration of phospholipid was less in plasma and in very low density lipoproteins with soy oil feeding than with tallow feeding. The weight percentage of cholesteryl ester in the low density lipoprotein fraction tended to be greater with 40% than with 20% tallow and tended to be less with 40% than with 20% soy oil. Phospholipid as a weight percentage of low density lipoprotein was least in pigs fed soy oil. Tallow feeding increased the percentage of myristic, palmitic, palmitoleic and oleic acids in plasma, relative to both other groups. Soy oil feeding increased the percentage of linoleic and linolenic acids. These moderate diets were not hypercholesterolemic, but they did alter plasma fatty acid composition and phospholipid concentrations in plasma and very low density lipoprotein.

Animals↗

Children with cancer: ethical dilemmas.

Ethical dilemmas have been called the "dark side of medical progress." However, ethical dilemmas can enlighten health care professionals. Nurses are examining these dilemmas to better resolve similar situations in the future. The role of the pediatric oncology nurse is important in the successful resolution of dilemmas related to the child with cancer. Pediatric oncology nurses are involved in all aspects of the process of informing the child and family about disease, and treatment, and they can encourage communication between the health care team and family. Finally, it is important that nurses keep abreast of landmark legal and ethical decisions affecting children and young adults. The controversy over parental rights v government-imposed choices will continue. "Baby Doe" and religious freedom struggles are two contemporary dilemmas. AIDS will set legal and ethical precedents. The outcome of these arguments will undoubtedly affect the care of the child with cancer.

Adolescent↗

Interrelationships between serum levels of amiodarone, desethylamiodarone, reverse T3 and the QT interval during long-term amiodarone treatment.

The interrelationships between serum levels of amiodarone, desethylamiodarone, and reverse T3, and changes in the corrected QT interval (delta QTc) were examined in 22 patients during long-term treatment with amiodarone. At 1, 3, and 6 months of follow-up, the correlation coefficient between serum levels of amiodarone or desethylamiodarone and reverse T3 ranged from 0.01 to -0.2 (p greater than 0.4). At the same time intervals, the correlation coefficient between both amiodarone and desethylamiodarone levels and delta QTc ranged from 0.1 to -0.1 (p greater than 0.6), and the correlation coefficient between reverse T3 and delta QTc also ranged between 0.1 to -0.1 (p greater than 0.5). Substituting percent delta QTc for delta QTc also did not reveal a significant correlation. These data demonstrate that serum levels of reverse T3 cannot be used as a substitute for serum levels of amiodarone in monitoring patients being treated with amiodarone. The absence of a correlation between serum reverse T3 levels and delta QTc suggests that the delay in repolarization which occurs during amiodarone therapy is not secondary to an amiodarone-induced abnormality in thyroid hormone metabolism.

Adult↗