The quality of soil organic matter, accessed by 13C solid state nuclear magnetic resonance, is just as important as its content concerning pesticide sorption.

The global increase of food production has been achieved mainly through the intensive use of inputs such as pesticides. Once released to the soil, sorption (which could be represented by Freundlich solid-water distribution coefficients - KF) and degradation are two governing processes that determine the distribution and persistence of pesticides in the environment. In spite of the huge dataset, the only apparent generalisation is the high correlation between KF and soil organic matter (SOM) content. However, in this work no correlation was observed between KF and organic C content (OC) and so the obtained KOC (KF normalised by OC) spread out in a wide range: 1100 to 11,400 mL g-1 for abamectin; and 30-150 mL g-1 for atrazine, both ranges corroborate with data from literature. These high variabilities indicate that other soil components or SOM quality strongly interfere in the pesticide sorption in addition to SOM content. Seeking to estimate the influence of SOM quality in the abamectin and atrazine KOC values, the humic acids, a fraction of the SOM, was analysed by 13C nuclear magnetic resonance spectroscopy (13C NMR) and Principal Component (PC) Regression. The first PC of 13C NMR spectra presented negative loadings for aliphatic compounds and positive loadings for aryl C, typical of partially oxidised pyrogenic C. Their scores showed strong correlation with the abamectin KOC values (R2 = 0.91, p < 5 10-8) and weaker with atrazine KOC (R2 = 0.63, p < 0.0001), in addition to a smaller standardised slope: 1.01 for abamectin and 0.76 for atrazine. These results could be explained by the higher hydrophobicity of abamectin, being thus more prone to interact with the polycondensed aryl groups from the pyrogenic C. It is also important to highlight that humic acids are useful proxies for understanding the paramount interaction of SOM with pesticides.

Effect of postnatal malnutrition on hyperoxia-induced newborn lung development.

Several factors are associated with bronchopulmonary dysplasia. Among them, hyperoxia and lung immaturity are considered to be fundamental; however, the effect of malnutrition is unknown. Our objective was to evaluate the effects of 7 days of postnatal malnutrition and hyperoxia on lung weight, volume, water content, and pulmonary morphometry of premature rabbits. After c-section, 28-day-old New Zealand white rabbits were randomized into four groups: control diet and room air (CA, N = 17), control diet and > or = 95% O2 (CH, N = 17), malnutrition and room air (MA, N = 18), and malnutrition and > or = 95% O2 (MH, N = 18). Malnutrition was defined as a 30% reduction of all the nutrients provided in the control diet. Treatments were maintained for 7 days, after which histological and morphometric analyses were conducted. Lung slices were stained with hematoxylin-eosin, modified orcein-resorcin or picrosirius. The results of morphometric analysis indicated that postnatal malnutrition decreased lung weight (CA: 0.83 +/- 0.19; CH: 0.96 +/- 0.28; MA: 0.65 +/- 0.17; MH: 0.79 +/- 0.22 g) and water content, as well as the number of alveoli (CA: 12.43 +/- 3.07; CH: 8.85 +/- 1.46; MA: 7.33 +/- 0.88; MH: 6.36 +/- 1.53 x 10-3/mm) and elastic and collagen fibers. Hyperoxia reduced the number of alveoli and increased septal thickening and the mean linear intercept. The reduction of alveolar number, collagen and elastic fibers was intensified when malnutrition and hyperoxia were associated. These data suggest that dietary restriction enhances the magnitude of hyperoxia-induced alveolar growth arrest and lung parenchymal remodeling. It is interesting to consider the important influence of postnatal nutrition upon lung development and bronchopulmonary dysplasia.

Effect of postnatal malnutrition on hyperoxia-induced newborn lung development

Several factors are associated with bronchopulmonary dysplasia. Among them, hyperoxia and lung immaturity are considered to be fundamental; however, the effect of malnutrition is unknown. Our objective was to evaluate the effects of 7 days of postnatal malnutrition and hyperoxia on lung weight, volume, water content, and pulmonary morphometry of premature rabbits. After csection, 28-day-old New Zealand white rabbits were randomized into four groups: control diet and room air (CA, N = 17), control diet and ¡Ý95% O2 (CH, N = 17), malnutrition and room air (MA, N = 18), and malnutrition and ¡Ý95% O2 (MH, N = 18). Malnutrition was defined as a 30% reduction of all the nutrients provided in the control diet. Treatments were maintained for 7 days, after which histological and morphometric analyses were conducted. Lung slices were stained with hematoxylin-eosin, modified orcein-resorcin or picrosirius. The results of morphometric analysis indicated that postnatal malnutrition decreased lung weight (CA: 0.83 ¡À 0.19; CH: 0.96 ¡À 0.28; MA: 0.65 ¡À 0.17; MH: 0.79 ¡À 0.22 g) and water content, as well as the number of alveoli (CA: 12.43 ¡À 3.07; CH: 8.85 ¡À 1.46; MA: 7.33 ¡À 0.88; MH: 6.36 ¡À 1.53 x 10-3/mm) and elastic and collagen fibers. Hyperoxia reduced the number of alveoli and increased septal thickening and the mean linear intercept. The reduction of alveolar number, collagen and elastic fibers was intensified when malnutrition and hyperoxia were associated. These data suggest that dietary restriction enhances the magnitude of hyperoxia-induced alveolar growth arrest and lung parenchymal remodeling. It is interesting to consider the important influence of postnatal nutrition upon lung development and ronchopulmonary dysplasia.

Prediction of length of hospital stay in neonatal units for very low birth weight infants.

OBJECTIVE: To develop models for estimating the length of hospital stay (LOS) of very low birth weight infants (VLBW), based on perinatal risk factors present during the first week of life and during the entire hospitalization period. STUDY DESIGN: The files of 155 VLBW were analyzed, and the influence of individual risk factors were initially evaluated by univariate analysis, using multiple-regression. Two mathematical models were built to estimate the LOS. RESULTS: The first model, using risk factors present during the first 3 days of life, is as follows: LOS = -0.074A + 22.06B + 22.85C - 16.78D - 2.07E + 10.51F + 203.12 (R2 = 0.63). (The letters are added to show what each number represents: A: birth weight; B: occurrence of respiratory distress syndrome; C: endotracheal intubation during resuscitation; D: 1-minute Apgar score; E: gestational age; F: presence of complications during delivery.) The second model, using factors present during the entire hospitalization period, is: LOS = 0.61G + 29.19H + 24.68I + 14.21J + 23.56K + 9.54L + 7.41M + 20.43 (R2 = 0.82). (G: age receiving nutritional support of > or = 120 kcal/kg per day; H: occurrence of systemic candidiasis; I: birth weight < 1000 gm; J: presence of delivery complication; K: occurrence of bronchopulmonary dysplasia; L: birth weight > or = 1000 gm and < or = 1249 gm; M: occurrence of anemia). CONCLUSION: Both models are applicable for estimating the hospitalization period, and the addition of variables present during the entire hospitalization period improved the accuracy of the model.

Effects of ventilation style on surfactant metabolism and treatment response in preterm lambs.

We investigated whether the style of ventilation would influence respiratory physiology or surfactant metabolism in surfactant-treated preterm lambs. Preterm lambs were delivered at 131 +/- 1 d gestation and treated with an organic solvent extract of sheep surfactant (100 mg/kg). The lambs were randomized to ventilation peiods of 2 h, 5 h, 10 h, or 24 h, and to ventilation with a low rate (15 breaths/min) and high VT (15 ml/kg), with a high rate (50 breaths/min) and low VT (8 ml/kg), or with high-frequency oscillatory ventilation (HFOV). Gas exchange and lung volumes were similar across time and for the different ventilation styles. Saturated phosphatidylcholine (SatPC) in alveolar lavage was lower for the HFOV group than for the other ventilation groups at 10 h and 24 h. The rate of loss of surfactant protein B (SP-B) from these preterm animals' lungs was slow and not influenced by ventilation style. The percentages of surfactants in large-aggregate forms were not changed by style of ventilation, and the large-aggregate surfactants had excellent function when tested in surfactant-deficient preterm rabbits. Alveolar lavage protein was low (30 ml/kg), and tissue hyaluronan did not change with time or ventilation style. In preterm lambs ventilated without causing injury, the extreme styles of ventilation examined in the study had minimal effects on lung function, surfactant function, or surfactant metabolism.

[Respiratory distress in low birth weight: influence of intrauterine growth retardation]. / Insuficiência respiratória em recém-nascidos de baixo peso: influência do retardo de crescimento intra-uterino.

The aim of this study is to evaluate the influence of intra-uterine growth retardation (IUGR), as well as it's types and severity on the development of respiratory distress among low-birth-weight infants. A total of 673 neonates were studied, the small-for-dates infants (SFD), 40% of total, were divided according to the type of IUGR, in proportionate and disproportionate, and according to the severity, in birth weight below 3rd and between 3rd and 10th percentile. Respiratory distress was more frequent among the appropriate for gestational age (57.3%) compared to the SFD infants (33.7%), (p < 0.0001), and among males (52.6%) compared to females (47.4%) (p = 0.01). There was an inverse relationship between gestational age, as well as birth weight and respiratory distress. It occurred in 90.6% of very-low-birth-weight infants and in 39% of the others, with a predominance among the appropriate for gestational age newborns. Respiratory distress occurred in 80% of neonates below 34 weeks of gestational age and in 26% of the neonates above it (p < 0.0001). Regarding to the small-for-dates infants, respiratory distress occurred more frequently among the disproportionate (42.5%), when compared to proportionate infants (28.1%) (p = 0.03). The severity of IUGR had no influence on these results. The authors concluded that among low birth weight infants, the groups with increased risk for respiratory distress are the appropriate for gestational age and, among small-for-dates and disproportionate infants, those weighing less than 1500 g.

Postnatal lung function and protein permeability after fetal or maternal corticosteroids in preterm lambs.

We evaluated postnatal lung function and intravascular albumin loss to tissues of 123-days-gestation preterm surfactant-treated and ventilated lambs 15 h after direct fetal (n = 8) or maternal (n = 9) betamethasone treatment or saline placebo (n = 9). The betamethasone-treated groups had similar increases in dynamic compliances, ventilatory efficiency indexes, and lung volumes relative to controls (P < 0.05). The losses of 125I-labeled albumin from blood, a marker of intravascular integrity, and the recoveries of 125I-albumin in muscle and brain were similar for control and betamethasone-exposed lambs. Betamethasone-treated lambs had lower recoveries of 125I-albumin in lung tissues and in alveolar washes than did controls (P < 0.01). Although blood pressures were higher for the treated groups (P < 0.05), all groups had similar blood volumes, cardiac outputs, and organ blood flows. Maternal or fetal treatment with betamethasone 15 h before preterm delivery equivalently improved postnatal lung function, reduced albumin recoveries in lungs, and increased blood pressures. However, prenatal betamethasone had no effects on the systemic intravascular losses of albumin or did not change blood volumes.

Surfactant protein-B and lung function in surfactant-treated preterm lambs.

We asked if the amount of SP-B (range 37-410 micrograms/ml) in surfactants used to treat preterm lambs at 123 days of gestation correlated with postnatal lung function or the SP-B content of surfactant recovered by alveolar washes after 10 h ventilation. Ventilation was initiated using a low tidal volume strategy to minimize early lung injury. There were small increases in compliance for the lambs treated with surfactants containing more than 37 micrograms/ml SP-B and an increased lung volume for lambs treated with a surfactant containing 385 micrograms/ml/ml relative to the surfactant containing 37 micrograms/ml SP-B. The amount of SP-B in the surfactant used for treatment correlated linearly with the amount of SP-B in the surfactant recovered from the lambs (r = 0.95, p < 0.001). Albumin leak from the vasculature to the airspace was low as was total protein in alveolar washes, indicating minimal lung injury. The SP-B content of surfactant (from 37 to 410 micrograms/ml) had minimal effects on postnatal lung function over a 10-hour study period in lambs ventilated in a manner to minimize lung injury.

Surfactant inhibition by plasma: gestational age and surfactant treatment effects in preterm lambs.

The preterm infant with respiratory distress syndrome has edematous lungs and small amounts of surfactant that do not function normally. We reported that surfactant recovered from preterm lambs after surfactant treatment can have decreased sensitivity to inhibition of surface tension by plasma. We asked whether this augmented resistance to inhibition was dependent on lung development (gestational age) by testing sensitivity to plasma inhibition of 1) endogenous surfactant from preterm lambs and 2) surfactant from preterm lambs after treatment with an organic solvent-extracted natural sheep surfactant. Surfactant recovered after surfactant treatment of 121- or 128-days-gestation lambs had the same sensitivity to plasma inhibition as did the surfactant used to treat the lambs. Surfactant recovered from 134-days-gestation lambs had decreased sensitivity to inhibition. Lung maturation is a variable influencing surfactant inhibition by plasma.

Alveolar and tissue surfactant pool sizes in humans.

The amounts of surfactant in human lung tissue and in the alveolar pool have not been extensively reported. We used 24 human lungs from persons over the age range of 13 mo to 80 yr to investigate whether the amount of saturated phosphatidylcholine (Sat-PC) in the human lung changed with age. Lung lavages also were obtained from 10 lungs at autopsy for measurements of the alveolar Sat-PC and surfactant protein-A (SP-A) concentrations. We found that (mean +/- SEM) lung Sat-PC/body weight (28.4 +/- 2.2 mumol/kg), Sat-PC/lung protein (0.060 +/- 0.005 mumol/mg), and Sat-PC/lung deoxyribonucleic acid (DNA) (0.23 +/- 0.01 mumol/mg) did not vary significantly with age. The amounts of alveolar Sat-PC (1.9 +/- 0.2 mumol/kg) and SP-A (105 +/- 15 micrograms/kg) were lower than previous estimates in other species. The relatively small surfactant pools in the human may make the lung more susceptible to injuries that interfere with surfactant function.

Preterm betamethasone treatment of fetal sheep: outcome after term delivery.

OBJECTIVES: Although antenatal corticosteroids improve outcomes for preterm newborns, negative effects could result if preterm delivery does not occur. We investigated whether betamethasone treatment of preterm fetal sheep would alter cardiovascular, renal, and lung function after delivery at term. METHODS: Preterm fetal lambs were randomized at 126-128 days' gestation to receive single doses of saline (n = 6) or 0.5 mg/kg betamethasone (n = 7) by ultrasound-guided fetal intramuscular injection. The lambs were delivered by cesarean at term, 20 days after fetal treatment, then ventilated for 4 hours to evaluate lung, cardiovascular, renal, and endocrine newborn adaptive responses, as well as responses to mild hypoxia. RESULTS: Body and organ weights (brain, lung, heart, kidney, adrenal) were similar in the two groups. Values for blood gases and pH, mean arterial pressures, heart rates, glomerular filtration rates, renal osmolar clearance, and plasma cortisol, angiotensin II, epinephrine, and norepinephrine levels were similar between groups for 3 hours after delivery and before hypoxia. A 20-minute period of mild hypoxia resulted in increases in catecholamines, arginine vasopressin, and atrial natruretic factor in both betamethasone-treated and control lambs. However, hypoxia did not alter cardiovascular or lung function in either group. After reversal of hypoxia, measured physiologic parameters did not differ between groups. Kidney Na, K-adenosine triphosphatase activity was significantly higher for the betamethasone-treated lambs. CONCLUSION: Preterm fetal betamethasone administration does not alter neonatal pulmonary, cardiovascular, renal, or endocrine physiology after term delivery or in response to mild hypoxia.

Ultrasonic nebulized in comparison with instilled surfactant treatment of preterm lambs.

To evaluate the efficiency and distribution of ultrasonic nebulized versus instilled surfactant in the treatment of surfactant deficiency at varying degrees of maturation, twin or triplet lamb fetuses were delivered at 125 to 137 d gestational age and received nebulized natural surfactant (Neb Only), instilled surfactant followed by a second instilled dose (Inst/Inst), instilled surfactant followed by nebulized surfactant (Inst/Neb), or no surfactant (Control). The lambs were ventilated for 6 h. Twenty-eight lambs were categorized into two groups (low compliance versus moderate compliance) based on initial physiologic lung characteristics. Efficiency of deposition of nebulized surfactant directly correlated with the compliances and ventilatory efficiency indices measured at 15 min of age. The low-compliance group (Low Comp) had significantly lower efficiency of surfactant deposition (7.6 +/- 1.6%) than did the moderate-compliance group (Mod Comp) (23.4 +/- 2.5%) (p < 0.01). Overall, instilled surfactant had a reasonably homogeneous distribution, whereas nebulized surfactant had a less homogeneous distribution, except for the Low Comp, Inst/Neb group, which had a distribution pattern similar to that for instilled surfactant. The potential for nebulized surfactant therapy for respiratory distress syndrome (RDS) may be limited by the nonhomogeneous nature of ventilation in the preterm lung.

Postnatal lung responses and surfactant function after fetal or maternal corticosteroid treatment.

To evaluate the effect of dose and route of administration of betamethasone on subsequent postnatal lung function, pregnant ewes were randomized at 127 days gestation to receive maternal or fetal intramuscular doses of 0.2 or 0.5 mg/kg body wt betamethasone or saline. At delivery 24 h later, preterm lambs were treated with surfactant and ventilated for 4 h. The lambs exposed to 0.5 mg/kg betamethasone by either the maternal or fetal route had higher Po2 values, lung volumes, dynamic compliances, and ventilatory efficiency indexes, as well as lower ventilatory pressure requirements, than did control animals (P < 0.05). There were no consistent improvements in postnatal lung function for the 0.2 mg/kg dose given to the fetus or ewe. However, measurements of radiolabeled protein in the total lung were decreased in all treatment groups (P < 0.01). Surfactant that was recovered from all groups of lambs and fractionated to isolate the large-aggregate fraction improved lung volumes in preterm rabbits to a greater degree than the surfactant used to treat the lambs (P < 0.05). Surfactant recovered from both groups treated with 0.5 mg/kg betamethasone was less sensitive to inactivation by plasma than was surfactant from the 0.2 mg/kg groups or the controls (P < 0.01). Fetal or maternal treatment with 0.5 mg/kg betamethasone improved postnatal lung function and increased the resistance of surfactant to inactivation.

[Ceftriaxione associated biliary lithiasis in newborns-report of two cases]. / Calculose biliar associada com o uso de ceftriaxone em recém-nascidos. Relato de dois casos.

The occurrence of biliary calculosis as a complication of the use of ceftriaxone was first described in an 18-year-old patient with chronic granulomatosis. Since then many reports have been published on this type of complication both in children and in adults, but until the present moment, this complication had never been reported in pre-term neonates.The authors describe two cases of biliary calculosis associated with the use of ceftriaxone in preterm-newborns, emphasizing that due to the frequent use of this type of antibiotic in neonatal I.C.U., routine ultrasonographic control exams should be performed to diagnose this possible complication in all neonates receiving ceftriaxone.

Sindrome da brida amniotica / Amniotic band syndrome

Os autores descrevem um caso de sindrome da brida amniotica com comprometimento facial, cranial e pe torto congenito. As manifestacoes clinicas principais e a etiologia da sindrome sao discutidas, ressaltando o cuidado com o amniocentese no primeiro trimestre. A sindrome da brida amniotica (S.B.A.) tem varias sinonimias: constricao anular congenita, bandas amniogenicas, banda de tecido aberrante "adam complex" ("amniotic deformaty, adhesions, mutilations") e sequencia da brida amniotica. Ela e constituida por uma serie de anomalias anatomicas do recem-nascido, associadas a estrangulamento de partes feitas "in utero" levando a deformacoes, malformacoes ou roturas. A apresentacao deste caso clinico tem o objetivo de alertar os pediatras e obstetras para esta patologia pouco frequente e cujo diagnostico e muitas vezes feito erroneamente, em vista das multiplas caracteristicas que a sindrome da brida amniotica pode assumir.