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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Surfactant has led to a significant reduction in neonatal mortality for premature infants with lung immaturity and respiratory distress. However, surfactant therapy has been shown to be effective in the treatment of a number of other neonatal respiratory disorders and the evidence for surfactant use in such circumstances is presented. Meconium aspiration is characterised by severe atelectasis, the influx of neutrophils, edema, and hyaline membranes, with decreased levels of SP-A and SP-B and the large aggregate fraction of lung surfactant, and altered surfactant surface morphology. Meconium contains cholesterol, free fatty acids and bilirubin all of which can interfere with surfactant function in a dose-dependent fashion. Providing larger amounts of surfactant can overcome some of this inhibition. Animal models of meconium aspiration treated with surfactant have improved histology, lung mechanics and gas exchange. Studies in human infants with meconium aspiration have found elevated concentrations of total protein, albumin, and membrane-derived phospholipid in lung lavage fluid, and haemorrhagic pulmonary edema. Clinical studies in such neonates have reported improved gas exchange and clinical outcomes following surfactant treatment. More recently surfactant lavage has been shown to be a potentially efficacious therapy for such infants. The inflammatory exudate containing plasma proteins and cytokines which accompanies neonatal pneumonia may inactivate surfactant. Surfactant treatment given to animals following the tracheal instillation of group B Streptococcal resulted in significantly less bacterial growth and improved lung function. Small clinical experiences have demonstrated the benefit of surfactant to infants with pneumonia/sepsis. Pulmonary haemorrhage, which some consider a complication of surfactant therapy, has also been effectively managed using surfactant instillation. The hemoglobin and red blood cell lipids may act to inhibit natural surfactant and treatment with surfactant has been shown to improve outcome for infants with pulmonary haemorrhage. Animal models of congenital diaphragmatic hernia (CDH) have hypoplastic lungs with evidence of decreased lamellar bodies in their type II pneumocytes and resultant surfactant deficiency, and respond to surfactant replacement with improved gas exchange and lung mechanics. The lungs of human infants with CDH contain less phospholipids and phosphatidylcholine per milligram of DNA than control infants. Case reports have reported a benefit of surfactant for infants with CDH. In the near-term infants with severe respiratory distress, surfactant is one of the therapies along with inhaled nitric oxide and high frequency ventilations, that have resulted in improved outcomes. Surfactant treatment may be of significant benefit in newborn infants with respiratory compromise secondary to a number of insults, and further prospective evidence of its efficacy in such disorders is needed.
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PMID:Surfactant use for neonatal lung injury: beyond respiratory distress syndrome. 1498 Feb 86

Respiratory distress syndrome (RDS) is a multifactorial developmental disease caused by lung immaturity and presenting as high-permeability lung edema ("hyaline membrane disease"). It is characterized by a transient deficiency of alveolar surfactant during the first week of life. During the first few days of life, the alveolar surfactant pool size increases up to that in the controls. The allelic variants of the genes encoding the surfactant proteins (SP) SP-A1, SP-A2, SP-B, and SP-C have been associated with RDS. The main SP-A haplotype, interactively with the SP-B Ile131Thr polymorphism and with constitutional and environmental factors, influence the risk. Case reports on mutations with partially functional SP-B have been published. The genetic susceptibility factors depend on the degree of prematurity at birth, consistent with sequential differentiation of the lung and gestation-dependent differences in clinical presentation. The preferentially type 2 cell expressed genes involved in critical functions (such as ATP-binding cassette transporter, ABCA3), those involved in susceptibility to acute lung damage, and those with known susceptibility to other severe lung diseases (such as G protein-coupled receptor for asthma susceptibility, GPR154 alias GPRA) will possibly serve as candidate genes in future studies. RDS associated with near-term and term births may have a different genetic predisposition and pathogenesis compared to RDS after very preterm birth. As we learn more about the molecular consequences of allelic variation, new therapies based on a new generation of surfactant diagnostics and individualized therapies may follow.
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PMID:Genetic basis of respiratory distress syndrome. 1712 71

The generalized anatomic and physiologic immaturity of preterm infants of very low birth weight (VLBW) (<or=1,500 g) and extremely low birth weight (ELBW) (<or=1,000 g) places them at high risk for death or associated negative sequelae, including chronic lung disease of infancy (CLDI). The standard treatment for pulmonary immaturity, mechanical ventilation (MV) at birth, can lead to barotrauma, volutrauma, pulmonary edema, infection, and inflammation. To minimize these negative outcomes, multiple treatment strategies have been proposed and evaluated as to their subsequent clinical course. This article compares, contrasts, and integrates the use of MV, nasal continuous positive airway pressure (NCPAP), and surfactant administration to encourage and support consideration of their use in the VLBW and ELBW population. Supporting a reduction of the use of MV in favor of NCPAP is safe and recommended because this practice is likely to decrease the probable sequelae of CLDI while permitting an individualized approach.
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PMID:Techniques of early respiratory management of very low and extremely low birth weight infants. 2047 32


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