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Biomedical subjects

A L Olson

Publications and source records attributed to A L Olson.

53 records · Page 3Linked to original sources
PubMed1989

Renal conservation of carnitine by infants and adults: no evidence of developmental regulation.

To determine the efficiency of renal conservation of carnitine in infants, urinary carnitine excretion was measured at intervals in 10 infants while plasma carnitine concentration was manipulated by supplementing carnitine-free formula with 0 microM, 140 microM and 280 microM L-carnitine. As carnitine supplementation increased from 0 microM to 280 microM, fractional excretion of free carnitine increased tenfold from 0.6% to 6.0%; fractional excretion of acylcarnitine esters increased to a lesser degree (10.5-15.6%). At all supplementation levels fractional excretion of acylcarnitine esters was significantly greater than fractional excretion of free carnitine. We conclude that free and esterified carnitine are handled differently in the infant kidney. Results in infants were compared to previously reported data for adults. Mean fractional excretions of total, free and esterified carnitine by infants (7.2%, 5.4% and 12.7%, respectively) were similar to those by adults (6.5%, 5.0% and 15.0%). Thus, renal losses of carnitine apparently do not account for the low plasma carnitine concentrations observed in infants fed carnitine-free formulas.

Adult↗
PubMed1989

Low carnitine intake and altered lipid metabolism in infants.

We examined the effect of dietary carnitine on variables of lipid metabolism in human infants. Normal male full-term infants were fed an isolated soy-protein-based formula with or without added carnitine from age 6-9 d to age 112 d. Growth and food intake were measured throughout the study. At ages 56 and 112 d serum concentrations of carnitine, free fatty acids, and triglycerides and urinary excretion of carnitine and medium-chain dicarboxylic acids were measured. Serum carnitine concentrations were lower in all infants fed unsupplemented formula. There was no difference in growth or food intake between the two groups of infants. Serum free fatty acid concentrations were significantly higher in the infants not receiving dietary carnitine. Moreover, excretion of all three medium-chain dicarboxylic acids was significantly higher in infants not receiving dietary carnitine. We conclude that lack of dietary carnitine affects lipid metabolism of infants during the first 4 mo of life.

Carnitine↗
PubMed1989

Carnitine status of lactoovovegetarians and strict vegetarian adults and children.

Because carnitine is contained primarily in meats and dairy products, vegetarian diets provide a model for assessing the impact of prolonged low carnitine intake on carnitine status. Plasma carnitine concentrations and urinary carnitine excretion were measured in adults and children consuming a strict vegetarian, lactoovovegetarian, or mixed diet. In adults plasma carnitine concentration and urinary carnitine excretion of strict vegetarians and lactoovovegetarians were significantly lower than those in the mixed-diet group but were not different from each other. In children significant differences were found between all three diet groups for both plasma carnitine concentration and urinary carnitine excretion. The differences in plasma carnitine concentrations were greater in children than in adults, possibly reflecting the effects of growth and tissue deposition. Small differences between diet groups in adults do not suggest a nutritionally significant difference in carnitine status. Whether vegetarian children are at greater risk for overt deficiency is not answered.

Adolescent↗
PubMed1987

Measurement of epsilon-N-trimethyllysine in human blood plasma and urine.

A method for measurement of epsilon-N-trimethyllysine in human blood plasma and urine is described. An internal standard, delta-N-trimethylornithine, was added to plasma and urine specimens and the mixtures were deproteinized and/or hydrolyzed. Preliminary purification of epsilon-N-trimethyllysine and delta-N-trimethylornithine was achieved by sequential cation-exchange--anion-exchange chromatography. Amino acids in the column eluates were derivatized with o-phthalaldehyde and mercaptoethanol, and were separated by isocratic reversed-phase high-performance liquid chromatography in the presence of an ion-pairing reagent. Quantitation was achieved by post-column fluorometry. The limit of detection was 5 pmol of epsilon-N-trimethyllysine injected into the chromatograph. The procedure was suitable for determination of epsilon-N-trimethyllysine in 1 ml of plasma or 0.2-0.4 ml of urine. The method was applied to measurements of epsilon-N-trimethyllysine in plasma and urine of four systemic carnitine deficiency patients and six normal subjects. Plasma epsilon-N-trimethyllysine concentration was significantly lower in systemic carnitine deficiency patients compared to normal individuals, but no significant difference in urinary epsilon-N-trimethyllysine excretion was observed between the two groups.

Amino Acids↗
PubMed1987

gamma-Butyrobetaine hydroxylase activity is not rate limiting for carnitine biosynthesis in the human infant.

Carnitine biosynthesis was assessed in human infants by measuring changes in plasma carnitine concentration and rates of urinary carnitine excretion after infants were fed carnitine-free formulas with and without added epsilon-N-trimethyl-L-lysine or gamma-butyrobetaine. This study was undertaken to test the hypothesis that carnitine biosynthesis in the human infant is regulated by substrate availability rather than activity of gamma-butyrobetaine hydroxylase, the final enzyme in the carnitine biosynthetic pathway. Ten infants were fed carnitine-free formula supplemented with either 500 microM epsilon-N-trimethyl-L-lysine or 500 microM gamma-butyrobetaine for 14 d. Plasma carnitine concentration and rate of urinary carnitine excretion were measured in infants before and after this period. Plasma carnitine concentration increased twofold when infants were fed either epsilon-N-trimethyl-L-lysine and increased threefold when infants were fed gamma-butyrobetaine. The rate of carnitine excretion doubled when infants were fed epsilon-N-trimethyl-L-lysine and increased 30-fold when infants were fed gamma-butyrobetaine. Absorption of epsilon-N-trimethyl-L-lysine was verified by demonstrating increased urinary excretion of epsilon-N-trimethyl-L-lysine in infants fed this substrate. We conclude that gamma-butyrobetaine hydroxylase activity is not rate limiting for carnitine biosynthesis in the human infant. Development of renal and hepatic gamma-butyrobetaine hydroxylase activity was determined in necropsy tissue from individuals of various ages. It was verified that gamma-butyrobetaine hydroxylase activity is developmentally regulated in the liver, but not in the kidney. The clinical relevance of this observation is diminished in view of the results of the in vivo studies of carnitine biosynthesis in infants.

Adolescent↗
PubMed1986

Congenital liver cyst presenting as congenital diaphragmatic hernia.

A 5-day-old infant was found to have an unusual presentation of a congenital liver cyst. The cyst arose from the left lobe of the liver and herniated into the left thoracic cavity through a congenital defect at the central tendinous portion of the diaphragm. The association between a congenital liver cyst and the location of the diaphragmatic hernia suggests that the abnormality occurred during very early embryonic development when the liver rapidly expands and extends into the septum transversum at the base of the heart. A small amount of liver tissue might well have perforated through the thinnest central portion of the septum transversum and underwent cystic degeneration due to incarceration.

Cysts↗
PubMed1982

Orcein stain.

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Hepatitis B↗
PubMed1980

Prevention and treatment of serous otitis media with an oral antihistamine. A double-blind study in pediatric practice.

Serous otitis media (SOM) is a common and troublesome disease in childhood. Although antihistamines are commonly prescribed to prevent or treat SOM, there have been no controlled clinical trials to determine the efficacy of such interventions. This study was designed to determine if antihistamines are of value in the prevention or treatment of SOM. Using a randomized double-blind method, 206 children with acute otitis media were treated with antibiotics and either brompheniramine maleate or placebo. The children were evaluated two weeks later by tympanometry and, independently, by combined pneumatoscopy and otoscopy. There were no significant differences overall between the treatment and control groups in terms of preventing SOM: 44% of those on antihistamine and 41% of those on placebo had SOM after two weeks of therapy. However, children with a history of serous otitis media did significantly better on placebo than did those on antihistamine, and children without a history of serous otitis media did significantly better on antihistamine than did those on placebo. One hundred children continued to use antihistamine or placebo for four more weeks. There were no significant differences between the treatment and control groups in terms of resolution of SOM (64% versus 68%).

Adolescent↗
PubMed1978

Prevention and therapy of serous otitis media by oral decongestant: a double-blind study in pediatric practice.

We studied the efficacy of (1) preventing the development of serous otitis media (SOM) by using an oral decongestant in children with acute otitis media and (2) treating SOM with an oral decongestant. In a randomized double-blind study, 190 children were treated for acute otitis media with antibiotics and either pseudoephedrine hydrochloride (Sudafed) or placebo. They were evaluated two weeks later by tympanometry and (independently) by clinical evaluation and pneumotoscopy. There were no significant differences between the two groups, except that males developed SOM significantly more often than did females. Use of decongestant and placebo was continued in 78 patients with SOM for up to four more weeks. Again, there were no siginificant differences between the treatment groups except that patients with an allergic history did significantly worse using a decongestant. Overall there was no benefit from pseudoephedrine in either the prevention or treatment of SOM.

Acute Disease↗
PubMed1971

Vasitis nodosa.

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Adult↗
PubMedDate not supplied

Reversal of flow in the left pulmonary artery after cavopulmonary connection.

The postoperative course of a 15-month-old girl who underwent a bilateral bidirectional cavopulmonary connection was complicated by a left chylothorax and left hemidiaphragm paralysis. Two-dimensional and Doppler echocardiography revealed complete flow reversal in the left pulmonary artery. This flow abnormality was confirmed by angiography. Multiple aortopulmonary collaterals had also developed and were coil embolized at the time of catheterization. Coil embolization of the collaterals, combined with relief of the chylothorax and diaphragmatic plication, reestablished forward flow in the left pulmonary artery.

Cardiac Catheterization↗
PubMedDate not supplied

Primary care pediatricians' roles and perceived responsibilities in the identification and management of depression in children and adolescents.

OBJECTIVE: To describe primary care pediatricians' 1) approach to the identification and management of childhood and adolescent depression and 2) perception of their skills, responsibilities, and barriers in recognizing and managing depression in children and adolescents. DESIGN AND METHODS: National cross-sectional survey of randomly selected primary care pediatricians that assessed the management of recalled last case of child or adolescent depression, attitudes, limitations to care from barriers and skills, and willingness to implement new educational or intervention strategies to improve care. RESULTS: There were 280 completed surveys about child and adolescent depression (63% response rate). Pediatricians overwhelmingly reported it was their responsibility to recognize depression in both children and adolescents (90%) but were unlikely to feel responsible for treating children or adolescents (26%-27%). Those with most of their practice in capitated managed care were less likely to feel responsible for recognizing depression in either children or adolescents. Forty-six percent of pediatricians lacked confidence in their skills to recognize depression in children, and few of them (10%-14%) had confidence in their skills in different aspects of treatment with children or adolescents. Diagnostic, assessment, and management details for their last recalled case of depression in a child or adolescent were provided by 248 of these pediatricians. In addition to referring 78%-79% of the cases to mental health care professionals, 77% of pediatricians provided a wide range of brief interventions. Only 19%-20% prescribed medication. Major factors cited that limited their diagnosis or management were time (56%-68%) and training or knowledge of issues (38%-56%). Fewer pediatricians noted limitations due to insurer or financial issues (8%-39%) or patient issues (19%-31%). The 35% of pediatricians who were motivated to change their recognition and management of suspected depression were significantly more interested in implementing in the future a variety of new strategies to improve care. CONCLUSION: Primary care pediatricians felt responsible for recognizing but not for treating child and adolescent depression. Although the lack of confidence and lack of knowledge and/or skills and time issues are major barriers that limit pediatricians in their treatment of childhood and adolescent depression, pediatricians varied in their readiness to change, with some being more willing to implement new strategies to care for depression. Educational and practice interventions need to focus on how to assist all pediatricians in diagnosis and to prepare these motivated pediatricians to manage depression in primary care settings.

Adolescent↗
PubMedDate not supplied

Model system of ongoing care for native Americans--a 5-year followup.

In 1979, continuing care from a personal physician was identified as a priority at the Indian Health Service site in Zuni, NM, a rural hospital and ambulatory care center serving 7,000 Zuni people. To encourage such care, a system was established that assigned each patient to a regular physician and organized physicians into teams. Three teams, each consisting of three clinicians and other support personnel, served specific geographic regions of the village. Five years later, the ongoing care provided for active randomly selected prenatal, diabetic, and general clinic patients was evaluated. The physician staff of the site had gone through a complete turnover during the previous five years. Based on a chart review for the year prior to patient identification, patients saw their regular physician from 48 to 61 percent of the time in all their visits, and their regular physician or his or her team colleague from 71 to 82 percent of the time in all their visits. Ongoing care from a personal physician or close colleague can be achieved in the Indian Health Service. Organization of physicians into teams appeared to be the critical element in promoting ongoing care at this site where physician turnover is high. Team physicians seldom all leave at once, and ongoing care as a priority is passed on by the attitude of other team physicians, by transfer of specific patients, and by patient expectation. Given the established benefits, ongoing care from a personal provider should be encouraged in the Indian Health Service as in other primary care settings.

Adult↗
PubMedDate not supplied

Political and cultural factors in achieving continuity with a primary health care provider at an Indian Health Service hospital.

A primary care system was established at Zuni-Ramah Indian Health Service Hospital and clinic in New Mexico. Continuity and coordination of care were added to a health care system that was already accountable, accessible, and comprehensive. The new system offered each patient a personal health care provider who worked as a member of a multidisciplinary team. In changing the health care system, special attention was given to its cultural and political setting, the village of Zuni. After thorough discussion with community and staff, community members' concerns about patients' privacy and free choice were better understood, and special efforts were made to safeguard them. Ongoing evaluation is essential to maintain continuity. Eight months after the primary care system was begun, 64 percent of patients who came for care had established a personal relationship with a health care provider. For 59 percent of the visits during the 1-month evaluation period, patients saw their regular provider and, for 82 percent, patients saw their provider or one of his or her team colleagues. These percentages include night and walk-in visits. The system required no extra funding or staff. The political process of planning and consultation helped anticipate and alleviate the community's concerns, but resistance from physician's assistants and some physicians was unexpected. A flexible approach has led to a gradual acceptance of this voluntary system. This experience with the people of Zuni village shows that a primary care system can be started in a rural Indian Health Service facility with minimal outside help. Apparent improvements in quality of care make the continuity of primary care worthy of further consideration in the IHS and similar health services systems.

Continuity of Patient Care↗