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Biomedical subjects

L Lands

Publications and source records attributed to L Lands.

9 recordsLinked to original sources
PubMed2000

Monitoring of 25-OH vitamin D levels in children with cystic fibrosis.

BACKGROUND: Patients with cystic fibrosis are at risk for malabsorption of fat-soluble vitamins, and those with low 25-OH vitamin D levels have a higher risk of low bone mineral density and long-term skeletal complications. It is currently recommended that vitamins A and E be monitored yearly; however, no recommendations exist for 25-OH vitamin D. Because all three vitamins are fat-soluble, the hypothesis in the current study was that low levels of vitamins A and E could identify patients at risk for low 25-OH vitamin D, so that 25-OH vitamin D measurements could be obtained in only selected circumstances. METHODS: Forty (21 girls) patients with CF, age 10.5 +/- 3.9 (SD) years, were assessed in a cross-sectional survey for ideal weight for height (percentage of predicted), spirometry (percentage of predicted FEV1, 33/40 patients), and serum levels of vitamins A, E, 25-OH vitamin D, and cholesterol (37/40 patients). RESULTS: Nine (22.5%) of 40 patients were malnourished (percentage of predicted ideal weight for height <85%), 7 (21.2%) of 33 had moderate to severe lung disease (FEV1 <60%), 4 (10%) of 40 had low levels of vitamin A, 3 (7.5%) of 40 had low vitamin E levels, 4 (10.8%) of 37 low vitamin E/cholesterol levels, and 4 (10%) of 40 had marginal or low levels of 25-OH vitamin D (<40 mmol/l). The patients with low 25-OH vitamin D were older, with no child < 12 years of age having a 25-OH vitamin D level less than 40 mmol/l. They also had lower vitamin E and vitamin E/cholesterol levels than those with normal 25-OH vitamin D levels. The groups did not differ in percentage of predicted ideal weight for height, lung function, or vitamin A levels. The best positive predictor for 25-OH vitamin D less than 40 mmol/l was low vitamin E (66.7%), with a negative predictive value of 94.6%. 25-OH vitamin D levels correlated with vitamin E/cholesterol levels (r = 0.41, P < 0.01) and weakly with vitamin E levels (r = 0.28, P < 0.08), but not with vitamin A levels. CONCLUSIONS: These results suggest that children aged less than 12 years and older children with normal vitamin E levels are especially unlikely to have low 25-OH vitamin D levels, and this measure can therefore be omitted. In contrast, those children with low vitamin E levels may warrant monitoring.

Adolescent↗
PubMed1992

Cardiopulmonary response to exercise in anorexia nervosa.

Malnutrition is associated with a number of systemic diseases that are often accompanied by severe exercise limitation. Anorexia nervosa (AN) is a disease characterized by malnutrition due to psychological factors rather than systemic disease. Diminished exercise capacity in AN has been attributed to a loss of muscle mass, dysfunction of remaining muscle, and impaired cardiovascular responses. In order to evaluate the role of malnutrition in the cardiopulmonary response to exercise, nine adolescent girls with AN were evaluated during progressive and steady-state exercise testing using a cycle ergometer. Nutritional status was assessed by body mass percentile (BMP) and percent ideal weight (PIWT). Cardiac output was measured by the indirect (CO2 rebreathing) Fick method. Maximum work capacity (Wmax) was expressed as a percent of predicted for sex and height, and cardiac output as a percent of predicted for oxygen consumption. To ensure that the laboratory values were comparable to the predicted values, a control group consisting of ten adolescents was studied concurrently. Wmax was below the 95% confidence interval in six of nine of the AN group (mean +/- SD: 70 +/- 22% predicted), whereas two of ten controls were below and one above this interval (112 +/- 37%). Wmax correlated with nutritional status (BMP: r = 0.75; P less than 0.001; PIWT: r = 0.8, P less than 0.001). Ventilatory responses for CO2 production at steady state and for Wmax were appropriate in both groups. Cardiac output was appropriate in both the controls (103 +/- 12%) and the AN group (104 +/- 14%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

The effects of nutritional status and hyperinflation on respiratory muscle strength in children and young adults.

Malnutrition and hyperinflation may both lead to respiratory muscle weakness. To assess separately the effects of chronic hyperinflation and malnutrition on respiratory muscle strength (RMS), 22 subjects with cystic fibrosis (CF) with both hyperinflation and malnutrition were compared to 10 asthmatic patients, a group with hyperinflation without malnutrition, 9 subjects with anorexia nervosa (AN), a group with malnutrition without lung disease, and 14(6 males and 8 females) control subjects with neither compromise. Nutritional status was assessed by body mass percentile (BMP) and percentage ideal weight (PIWT). RMS was diminished in the AN and CF groups (PImax 90 +/- 27, 88 +/- 31 versus 124 +/- 40 cm H2O, p less than 0.05; PEmax 87 +/- 12, 93 +/- 39 versus 121 +/- 32 cm H2O, p less than 0.05), but no difference was found when the AN group was compared with only the female controls. The decrease in PImax in the CF group was primarily due to the mechanical disadvantage placed on the diaphragm by their marked hyperinflation, a mean RV/TLC ratio of 50 +/- 23%. As older CF subjects had previously been shown to have decreased RMS when malnourished, a CF subgroup in the same age range as the controls was evaluated. RMS in this group did not differ from controls despite the presence of malnutrition and hyperinflation. RMS is mildly influenced by nutritional status as assessed by BMP and PIWT but not to any degree of clinical significance.

Adolescent↗
PubMed1988

Childhood asthma: prevention of attacks with short-term corticosteroid treatment of upper respiratory tract infection.

In this study, the potential for short courses of glucocorticoids to prevent or reduce the severity of asthma induced by viral respiratory infections in preschool children was investigated. Two groups of children with a mean age of 36.4 +/- 3.9 months and 40.4 +/- 4.9 months were monitored during a 2-year period. Group 1, considered as the control group, received theophylline preparations and orciprenaline either on a continuous basis or during attacks. During severe attacks, albuterol was administered by nebulization, with corticosteroids occasionally added for seven to 14 days in cases of poor response to albuterol. Group 2 received the same treatment during the first year. During the second year, however, a short-term course of prednisone (1 mg/kg) was given as soon as the first symptoms of an upper respiratory tract infection appeared, prior to any signs of wheezing. Results indicate that, whereas morbidity remained constant in the control group during the 2-year observation period, a significant decrease in the number of wheezing days (65%), attacks (56%), visits to the emergency room (61%), and hospitalizations (90%) occurred in group 2. It was concluded that preschool children who suffer from repeated asthma attacks related to upper respiratory tract infections may benefit greatly from the preventive administration of corticosteroids.

Albuterol↗
PubMed1986

Maximal static pressures and lung volumes in a child with Guillain-Barré syndrome ventilated by a cuirass respirator.

Serial maximal static pressure and lung volume measurements were made in a child with Guillain-Barré syndrome and respiratory failure. The patient received successfully ventilatory support for seven weeks with the use of a cycled negative-pressure cuirass-type respirator obviating prolonged intubation and tracheostomy. The fall in VC preceded the loss of respiratory muscle strength (RMS) and lagged behind RMS in the return towards normal values. There was a disproportionate loss of lung volume (lowest VC, 220 to 250 ml, 11 to 12 percent of normal) as compared to maximal static pressures (lowest PImax, 60 cm H2O, lowest PEmax, 47 cm H2O). The disproportion was greater than that previously reported in adults. The greater loss in lung volume may be due to greater chest wall compliance in the child, resulting in less outward recoil of the chest wall and subsequently more microatelectasis with denervation of the chest wall musculature. Loss of lung volume resulted in a smaller surface area over which the respiratory muscles exerted their force. Thus, pressure being equal to force divided by surface area, could be relatively maintained and not reflect the extent of the loss of muscle force.

Child↗
PubMedDate not supplied

Pancreatic function testing in meconium disease in CF: two case reports.

We report two infants with cystic fibrosis (CF), presenting with meconium ileus and meconium plug, who had no clinical or biochemical evidence of pancreatic insufficiency during infancy. They underwent pancreatic secretory function testing at 11 and 9 months of age, respectively. Both patients had sufficient lipase and colipase secretion to maintain normal digestion of fat, confirming that meconium disease in CF does not necessarily imply pancreatic insufficiency and the need for enzyme supplementation in infancy. Nonetheless, we documented markedly reduced enzyme secretion in both patients, implying a potential role for the pancreas in the pathogenesis of meconium disease, even when clinical pancreatic insufficiency is absent. In addition, our patient with meconium ileus had a severely limited fluid secretory capacity (10.3% of mean normal values). In contrast, the patient with the milder presentation of meconium plug had a far greater ability to secrete fluid (75% of mean normal), but had poorer pancreatic proteolytic activity. We suggest that impaired fluid secretion may be a very significant factor in the pathogenesis of meconium ileus, and we speculate that an inability to maintain sufficient intraluminal fluid relative to the degree of pancreatic proteolytic deficiency may more adequately explain the risk of occurrence and the severity of intestinal obstruction in CF than either factor alone.

Age Factors↗