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Limited information is available on the metabolic fate of medium-chain triacylglycerols (triglycerides) after intestinal absorption and on their influence on essential fatty acid metabolism. We studied in preterm infants the effect of two infant formulas, one with a high (HMCT) and one with a low (LMCT) medium-chain triacylglycerol content, on plasma fatty acids. The HMCT formula contained 46 mol% 8:0+10:0 and the LMCT formula (4.8 mol% 8:0+10:0) had approximately twice the amount of long-chain saturated and monounsaturated fatty acids as the HMCT. Both formulas had similar contents of linoleic and linolenic acids. Plasma lipids and fatty acids were determined at birth and on day 24 of life in 20 infants fed the LMCT (n = 12) or HMCT (n = 8) formula. Significant amounts of medium-chain fatty acids were found in the systemic circulation of the-infants fed the HMCT formula, mainly in plasma fatty acids and triacylglycerols. Despite striking dietary differences, palmitic and stearic acids were not different between groups, indicating de novo synthesis of long-chain fatty acids with the HMCT formula. Plasma phospholipid docosahexaenoic acid was significantly lower in the HMCT group than in the LMCT infants (1.38 [+ or -] 0.07 compared with 1.73 + 0.07 mol%, P = 0.002). Our data indicate that a high MCT intake in preterm infants increases lipogenesis, and dietary nonessential fatty acids interfere with the metabolism of docosahexaenoic acid.

The purpose of this study is to evaluate the effect of disodium cromoglycate (DSCG) on gas exchange and ventilation during incremental exercise in asthmatic children with an [FEV.sub.1] fall less [...]

Anemia is a major complication of kidney failure and is responsible for reduced exercise tolerance and prolonged bleeding time, and may also contribute to abnormalities of the nervous system and other tissues. This has usually been treated by repeated transfusions, which has associated risks. However, recombinant erythropoietin (EPO), a protein made by the kidney that stimulates red blood cell synthesis, has been successfully used to treat anemia in both adults and children who were on dialysis because of kidney failure. However, some children have developed high blood pressure, possibly because the dose of EPO used was too high. EPO treatment in children has not been optimized, nor have the benefits or side effects been well studied. Ten anemic children with end-stage kidney failure, aged two to 18 years, were given increasing doses of EPO in order to establish the best treatment regimen. The treatment was aimed at achieving a target concentration of hemoglobin (the oxygen-carrying protein in red blood cells) at the low end of normal range, adjusted for age and gender. The study used hemoglobin values after dialysis, which are likely to be more stable than predialysis values, which have been used in previous studies. EPO increased hemoglobin to target values within eight to nine weeks for most subjects, and none required transfusions. Bleeding time decreased, probably because synthesis of platelets as well as red blood cells increased. Five of the nine children had detectable brain abnormalities but no symptoms, and these improved to normal levels after correcting the anemia. Abnormalities of peripheral nerves did not improve. Improved energy and well-being were described by families or patients, and exercise tolerance improved greatly. No changes in heart function were found, and the only case of severe high blood pressure appeared to be unrelated to EPO treatment. The study suggests that EPO given under conditions described in the study is a safe and effective treatment of anemic children with severe kidney disease. (Consumer Summary produced by Reliance Medical Information, Inc.)

The accumulation of T cells in the synovial membrane is the crucial step in the pathophysiology of the inflammatory processes characterizing juvenile idiopathic arthritis (JIA). In this study, we evaluated the expression and the pathogenetic role in oligoarticular JIA of a CXC chemokine involved in the directional migration of activated T cells, i.e. IFNγ-inducible protein 10 (CXCL10) and its receptor, CXCR3. Immunochemistry with an antihuman CXCL10 showed that synovial macrophages, epithelial cells, and endothelial cells bear the chemokine. By flow cytometry and immunochemistry, it has been shown that CXCR3 is expressed at high density by virtually all T lymphocytes isolated from synovial fluid (SF) and infiltrating the synovial membrane. Particularly strongly stained CXCR3+ T cells can be observed close to the luminal space and in the perivascular area. Furthermore, densitometric analysis has revealed that the mRNA levels for CXCR3 are significantly higher in JIA patients than in controls. T cells purified from SF exhibit a definite migratory capability in response to CXCL10. Furthermore, SF exerts significant chemotactic activity on the CXCR3+ T-cell line, and this activity is inhibited by the addition of an anti-CXCL10 neutralizing antibody. Taken together, these data suggest that CXCR3/CXCL10 interactions are involved in the pathophysiology of JIA-associated inflammatory processes, regulating both the activation of T cells and their recruitment into the inflamed synovium.

Background:Fractional exhaled nitric oxide (FENO) and exhaled carbon monoxide (ECO) have been proposed as markers of airway inflammation and oxidative stress. Objective:The aim of this study was to assess the effect of oral prednisone treatment on FENOand ECO levels in a group of 30 asthmatic children with asthma exacerbation. Methods:Thirty asthmatic children with asthma exacerbation were treated with oral prednisone for 5 days (1 mg/kg/day). Before and after prednisone therapy, ECO was measured by means of a chemical analyzer and FENOwas measured by means of a chemiluminescence analyzer. ECO and FENOwere also measured in a group of healthy nonatopic children. Results:Before therapy, both ECO values and FENOvalues were higher in asthmatic children (ECO, 3.2 ± 0.2 ppm; FENOonline, 74.9 ± 6.2 ppb; FENOoffline, 20.2 ± 1.4 ppb) than in healthy controls (ECO, 2.0 ± 0.2 ppm [P< .01]; FENOonline, 10.1 ± 0.8 [P< .0001]; FENOoffline, 5.9 ± 0.4 ppb [P< .0001]). An overlap in ECO values was found between healthy controls and asthmatic children. After prednisone therapy, there was a significant reduction in FENOvalues (FENOonline, 40.6 ± 4.6 ppb [P< .0001]; FENOoffline, 11.1 ± 0.8 ppb [P< 0.0001]) and a slight but nonsignificant decrease in ECO values (2.7 ± 0.2 ppm [P= not significant]) in the asthmatic group. No significant correlation between ECO values and FENOvalues was found in either the asthmatic children or the controls. Conclusions:After a course of prednisone therapy, in children with asthma exacerbation there is a significant decrease in FENObut no significant change in ECO levels. This possibly suggests that ECO is less sensitive than FENOto inhibition by corticosteroids. (J Allergy Clin Immunol 2002;109:440-5.)

Little is known about endogenous surfactant metabolism in infants, because radioactive isotopes used for this purpose in animals cannot be used in humans. We developed a novel and safe method to measure the endogenous surfactant kinetics in vivoin humans by using stable isotope labeled fatty acids. We infused albumin-bound [U-13C]palmitic acid (PA) and [U-13C]linoleic acid (LLA) for 24 h in eight critically ill infants (mean ± SD; weight: 3.7 ± 1.3 kg; age: 51.3 ± 61.6 d) who required mechanical ventilation. The 13C enrichment of PA and LLA in surfactant phosphatidylcholine (PC), obtained from tracheal aspirates, was measured by gas chromatography combustion interface-isotope ratio mass spectrometry. We measured a significant incorporation of both 13C-PA and 13C-LLA into surfactant PC. PC-PA and PC-LLA became enriched after 8.7 ± 4.9 h (range: 3.4-17.3) and 10.0 ± 7.2 h (range: 3.0-22.4), respectively; the times at maximum enrichment were 49.2 ± 8.9 and 45.6 ± 19.3 h, respectively. The fractional synthesis rate of surfactant PC-PA ranged from 0.4 to 3.4% per h, whereas the fractional synthesis rate of PC-LLA ranged from 0.5 to 3.8% per h. The surfactant PC-PA and PC-LLA half-lives ranged from 16.8 to 177.7 and 23.8 to 144.4 h, respectively. This method provides new data on surfactant metabolism in infants requiring mechanical ventilation. We found that synthesis of surfactant from plasma PA and LLA is a slow process and that there were marked differences in PC kinetics among infants. This variability could be related to differences in lung disease and could affect the clinical course of the respiratory failure.

Lipolysis has been measured in humans by means of stable isotope techniques using labeled palmitic acid (PA) or glycerol as tracers. If other fatty acids(FA) such as linoleic acid (LLA) have the same rate of appearance(Ra) as PA and therefore contribute equally to oxidative and nonoxidative metabolism is unknown. We infused albumin-bound [U-13C]PA and [U-13C]LLA in seven critically ill infants (weight 3.6 ± 1.3 kg, age 57 ± 64 d) receiving 20.9 ± 5.4 kcal· kg-1·d-1of i.v. glucose only, and measured simultaneously the Raof PA and LLA from the isotopic enrichment of plasma FFA by mass spectrometry. A needle biopsy of the s.c. adipose tissue was obtained for FA composition. PA in adipose tissue was higher than LLA (40 ± 6.7 versus 5.4 ± 3.2 mol%,p < 0.001). The Ravalues of PA and LLA were 5.73 ± 2.79 and 1.34 ± 0.92µmol·kg-1·min-1, respectively (p = 0.005). However, the ratio of the FA's Rato their respective mol% values in adipose tissue was lower for PA than for LLA (0.15 ± 0.06 versus 0.25 ± 0.06, p = 0.02). TheRaof LLA acid was higher than could be expected from the FA composition of adipose tissue, thus indicating a preferential release of LLA during lipolysis. In critically ill infants receiving only i.v. glucose, the contribution of LLA to the oxidative and nonoxidative metabolism may be larger than what assumed from the FA composition of plasma and adipose tissue.

The aim of this study was to evaluate the effect of correction of chronic anaemia on the physical performance and the cardiovascular response to effort in children with end-stage renal disease (ESRD) maintained by haemodialysis. Seven patients (mean age 13.9 years) underwent triangular-type treadmill exercise testing before [haemoglobin (Hb) 6.3±0.9 g/dl] and after (Hb 11.2±1.2 g/dl) anaemia correction with recombinant human erythropoietin (rHuEPO). After treatment, the work-load reached, the peak oxygen uptake and average ventilatory anaerobic threshold (VAT) values were significantly increased (P<0.01,P<0.001,P<0.05 respectively). VAT values, expressed as a percentage of normal values, increased from 55.7±16.6% to 82.4±21%. This improvement correlated well with the increase in Hb (r=0.79). Oxygen pulse also increased significantly, when tested after anacmia correction. In conclusion, these data demonstrate that when the anaemia of children with ESRD is corrected with rHuEPO, there is a clear improvement in acrobic work capacity and effort tolerance.

A novel application of Collisionally Activated Decomposition Mass analysed Ion Kinetic Energy (CAD MIKE) spectrometry to separation and positive structural identification of urinary methylmalonic acid (MMA) (the pathognomonic compound for the diagnosis of methylmalonic acidurias) is presented. CAD MIKES scans of EI ionic species at m/z119 ([M + H]+) and m/z101 ([M – OH]+) have been obtained from a pure standard of MMA and from crude urinary acid fractions. With reference to the procedures employed so far, the advantages of the proposed method lie in fast and simplified sample pretreatment and in a quick non-controversial response to a clinical suspicion of serious, life-threatening inherited metabolic diseases.

Summary The authors report the results of a genetic analysis performed in 34 neurofibromatosis type 1 (NF1) Italian families using five loci tightly linked to NF1: D17S33, D17S82, D17S83, D17S37, and D17S36. A twopoint linkage analysis was performed with the LINKAGE and the CRI-MAP programs. The map of the region was contructed using the MAP90 program. Data from the present study lend further support to evidence that all NF1 mutations are allelic and that the NF1 locus resides in the proximal region of chromosome 17q. Close linkage of NF1 to all the markers was found. Two of them, namely D17S82 and D17S83, showed the highest linkage with a value of 0 recombination frequency and lod scores of 3.77 and 4.02, respectively. The best map found is D17S33-D17S82-NF1-D17S83-D17S37-D17S36. The authors stress that knowledge of precise order is essential; if D17S82 and D17S83 are proved to flank the NF1 gene, they allow an acceptable presymptomatic diagnosis in informative families.

In an attempt to investigate the relationship between respiratory mechanics and pulmonary hemodynamics, we evaluated pulmonary function in 31 infants with left-to-right shunts and subsequent high pulmonary blood flow, undergoing cardiac surgery. Measurements were performed 1 d before and repeated 10 d and 4–5 wk after correction. The age of the patients ranged from 4 d to 24 mo, body weight from 2.7 to 11.8 kg. Pulmonary artery-pressure, assessed by Doppler echocardiography, was preoperatively elevated in 23 patients (group 1), whereas it was within normal values in eight infants (group 2). Respiratory mechanics were measured using the single-breath occlusion technique in sedated infants. To evaluate specific compliance, functional residual capacity was determined by using an open circuit nitrogen washout technique. A reduced preoperative compliance value (mean with 95 confidence interval) was found in group 1: 34.8 (26.5–43.1) mL. kPa−1. After hemodynamic correction, a progressive significant (p< 0.01) improvement was demonstrated at 10 d and 1 mo with values of 47.5 (39.2–55.8) mL. kPa−1and 56.5 (45.6–67.4) mL. kPa−1, respectively. A similar trend was noted evaluating specific compliance with values of 0.27 (0.24–0.30) kPa−1and 0.44 (0.42–0.46) kPa−1, respectively before and after surgery. Preoperative functional residual capacity value was 130 (100–160) mL. In group 2, normal preoperative compliance values were obtained, without significant changes after surgery. In both groups, resistance was within the normal range both before and after surgical correction, and functional residual capacity did not change either. No correlations were found between compliance and pulmonary artery pressure and pulmonary blood flow values. In conclusion, these results show that infants with left-to-right shunts and pulmonary hypertension present with reduced compliance of the respiratory system that rapidly improves after cardiac surgery.

ABSTRACT: In an attempt to investigate the relationship between respiratory mechanics and pulmonary hemodynamics, we evaluated pulmonary function in 31 infants with left-to-right shunts and subsequent high pulmonary blood flow, undergoing cardiac surgery. Measurements were performed 1 d before and repeated 10 d and 4–5 wk after correction. The age of the patients ranged from 4 d to 24 mo, body weight from 2.7 to 11.8 kg. Pulmonary artery-pressure, assessed by Doppler echocardiography, was preoperatively elevated in 23 patients (group 1), whereas it was within normal values in eight infants (group 2). Respiratory mechanics were measured using the single-breath occlusion technique in sedated infants. To evaluate specific compliance, functional residual capacity was determined by using an open circuit nitrogen washout technique. A reduced preoperative compliance value (mean with 95% confidence interval) was found in group 1: 34.8 (26.5–43.1) mL. kPa-1. After hemodynamic correction, a progressive significant (p < 0.01) improvement was demonstrated at 10 d and 1 mo with values of 47.5 (39.2–55.8) mL. kPa-1and 56.5 (45.6–67.4) mL. kPa-1, respectively. A similar trend was noted evaluating specific compliance with values of 0.27 (0.24–0.30) kPa-1and 0.44 (0.42–0.46) kPa-1, respectively before and after surgery. Preoperative functional residual capacity value was 130 (100–160) mL. In group 2, normal preoperative compliance values were obtained, without significant changes after surgery. In both groups, resistance was within the normal range both before and after surgical correction, and functional residual capacity did not change either. No correlations were found between compliance and pulmonary artery pressure and pulmonary blood flow values. In conclusion, these results show that infants with left-to-right shunts and pulmonary hypertension present with reduced compliance of the respiratory system that rapidly improves after cardiac surgery.

We have developed a simple rapid DNA screening test that allows us simultaneously to analyze seven CF mutations (deltaF508, R347P, S549N, G551D, R553X, R334W, 444delA) that together account for about 60% of all CF mutations in the Italian population. It consists of three steps: multiplex polymerase chain reaction (PCR) amplification of exons 4, 7, 10 and 11; restriction endonuclease digestion of the PCR products; and vertical polyacrylamide gel electrophoresis analysis. We have used our multiplex assay for analyzing 15 CF chromosomes (non delta F508) and have found 3 cases of the R553X mutation; the latter have been confirmed by amplification and digestion of exon 11.

The purpose of this study is to evaluate the effect of disodium cromoglycate (DSCG) on gas exchange and ventilation during incremental exercise in asthmatic children with an FEV1fall less than 15 percent from the baseline after the exercise. Seventeen children (aged 8 to 14 years) with a history of mild to moderate asthma but no clinical and spirometric evidence of exercise-induced asthma (EIA) underwent two maximal exercise tests in a randomized order: test A without premedication and test B after inhalation of DSCG, 40 mg. To evaluate the effect of DSCG on normal airways, nine healthy children performed the same exercise protocol. Pulmonary function was normal at rest and after treadmill exercise test (the mean postexercise fall in FEV1was 5.9 percent in test A and 1.5 percent in test B). Gas exchange, minute ventilation ( V˙e) and heart rate (HR) were monitored during running in both tests. In the asthmatic subjects, there were no differences in oxygen uptake ( V˙o2), carbon dioxide output ( V˙co2), and V˙eat rest between the two tests. During exercise, V˙e, V˙o2, V˙co2, and energy cost (EC [O2ml · kg−1· m−1]) of running in the asthmatic subjects were significantly lower in test B than in test A (analysis of variance, p<0.01) for comparable work rates. Maximal minute ventilation (VEmax) was significantly higher in test A (46.9±14.6[±SD] L · min−1) than in test B (43.2±14 L · min−1; p<0.05). We found no significant effect of DSCG on gas exchange and ventilation during exercise in the healthy children ( V˙emax 47.8±25 and 48.4±25 L · min−1in test A and B, respectively). In conclusion, premedication with DSCG appears to decrease the ventilatory cost of exercise in asthmatic children who do not present a substantial fall in FEV1after an exercise test without pretreatment.

Recurrent rejection is an uncommon, severe complication after heart transplantation that is associated with a poor long-term prognosis. Photopheresis (ECP), a new form of extracorporeal photo-chemotherapy used for the treatment of cutaneous T cell lymphoma and several autoimmune diseases, has also been used for prevention and treatment of acute rejection in heart transplant recipients. It seems to induce specific suppression of both cellular and humoral rejection. In this study, we evaluated whether ECP added to standard therapies allowed better control of rejection and reduction of conventional immunosuppressive drugs in patients with repeated rejection episodes. Eight heart transplant recipients (6 men and 2 women, mean age 48 yr), with recurrent rejection were treated with ECP for 6 months. Endomyocardial biopsies (EMB) were performed monthly. As a result of treatment, 7 patients on ECP experienced a reduction of the number and severity of rejection episodes. The fraction of EMB negative for rejection increased from 13 to 41, whereas the fraction of specimens with multifocal and/or diffuse moderate lymphocytes infiltration (grades 3A and 3B) decreased from 41 to 21. ECP allowed reductions of daily immunosuppressive therapy prednisone by 44 (16.9 vs. 9.4 mg), cyclosporine by 21 (366 vs. 291 mg), and azathioprine by 29 (137 vs. 97 mg). No major side effects were observed. We conclude that, although the number of patients is small, the use of ECP was safe and associated with improved control of recurrent rejection. This allowed tapering of immunosuppressive drugs, which was particularly useful in two patients with insulin-dependent diabetes and one with sternal wound osteomyelitis.

Following cystic fibrosis (CF) neonatal screening implementation, a high frequency of heterozygotes has been reported among neonates with elevated immunoreactive trypsinogen (IRT) and normal sweat chloride levels. We studied the relationship between normal IRT values and CF heterozygosity: 10,000 neonates were screened for CF by IRT measurement and tested for 40 CF mutations; the 294 carriers detected were coupled with newborns negative to the same genetic testing, and the two groups' IRT levels compared. Heterozygotes had higher IRT levels than their controls (mean 35.32 vs. 27.58 μg/L, P < 0.001). Even within normal trypsinogen range, the probability of being a CF carrier increases with neonatal IRT concentration. © 2005 Wiley‐Liss, Inc.

Little information is available on the ventilatory and gas exchange changes occurring during exercise in children with exercise induced asthma (EIA).The purpose of this study is to evaluate the pattern of gas exchange during exercise and the energy cost of running in asthmatic children with and without premedication. 12 children (7.1-15.5 years) with a history of mild-moderate bronchial asthma and EIA performed two maximal exercise tests on treadmill on separate days: 1) test A = without premedication; 2) test B = disodium cromoglycate (DSCG) (40 mg) was inhaled 30 min before exercise. After a 3-min resting evaluation, the sceed of the belt was set at 6.5 km/h and the inclination was increased stepwise by 2%. every minute until exhaustion. Oxygen uptake (VO2). carbon dioxide outoufc (VCO2), ventilation (VE), respiratory rate (RR) and heart rate (HR) were measured every 4 seconds. The nertent post-exercise fall in FEV1 was calculated. The energy cost (CE) of running, defined as the amount of energy (above pre-exercise resting} spent oer unit distance, was calculated as a function of the incline of the belt at each minute of exercise. None of the children was limited by dyspnoea during the run; the postexercise fall in FEV1 after test A was =20% for each child, the mean fall being 32.8±11.6% in comparison with 12.6±8.9% after test 8 to (p<0.001). The run time increased from 8.0±2.6 min in test A to 9.1±2.1 min in test S (p<0.01). Baseline VO2 was not different between the two tests, VO2max decreased from 43,9±7.7 ml/min/kg in test A to 37,7±6.0 lower in test B (p<0.01). VE (l/min) and CE of running (ml 027/kg/m) were significantly lower in test B from the second to the last minute of exercise. In conclusion children with post-exercise bronchcsoasm snow which level of ventilation which causes secondary increased O2 cost of oreathinc during exercise, when they are asymptomatic. Our results, that surprisingly demonstrate a decrease of VO2max with premedication, suggest that the energy cost of running is a is more reliable parameter than tne VO2max in the evaluation of exercise response in diseases, such as asthma, in which high values of oxygen uptake are not coupled to high values of external work.

We assessed the effectiveness of inhaled nitric oxide (NO) in two patients, of six and two months of age, who developed severe pulmonary hypertension after corrective cardiac surgery for a complete atrioventricular canal. In the post-op period, attempts to wean the patients from ventilatory support resulted in marked increase of pulmonary arterial pressure (PAP) to suprasystemic levels, with severe desaturation and metabolic acidosis. Two life-threatening episodes did need cardiac resuscitation in the second patient. Short administrations of inhaled NO, at 30 parts per million (ppm), dramatically reduced the PAP to about half the systemic values in the first patient (systemic arterial pressure (SAP)=35/24 and PAP=44/33 before NO, and SAP=58/38 with PAP=31/19 after five minutes of NO treatment), while in the second patient NO showed a slower effect on PAP, but an immediate improvement of hemodynamics. Thus, continuous inhaled NO, at 10-50 ppm, was administered through the ventilator, with good clinical response. Electrochemical analysis provided on line monitoring of NO and nitrogen dioxide (NO2) concentrations. NO2did not exceed 1.6 ppm. Inhaled NO was tapered to the minimal effective concentration able to maintain low pulmonary pressures and normal oxygenation. Treatment with NO was stopped after 55 and 62 hours, respectively. No complications were noted. Met hemoglobin levels ranged between 0.7-1.2% in case 1, and 0.1-5.1% in case 2. In the latter case, methemoglobin was directly correlated with NO concentration levels. Weaning was successful in both cases, with extubation performed on day 29 and day 17 post-op, respectively.CONCLUSIONS: Inhaled nitric oxide at concentrations of 10-50 ppm exerts a potent dilatory effect on pulmonary vascular bed in children with congenital heart disease who present pulmonary hypertension after surgical correction. Although toxicity by NO and NO2seems to be negligible at these dosages, continuous on-line gas monitoring is recommended.