Briefly explain what cystic fibrosis is and how dornase alfa acts to solve the problem

Cystic fibrosis is genetic metabolic disease (↓ DNase 1, not have enough lead to decreased secretions in various organs especially airways) which leads to decreased secretions in various organs. Dornase alfa (rhDNase I) hydrolyses extra-cellular DNA from the neutrophils in the bronchial mucus, increasing its liquidity drastically. It is related to the natural enzyme deoxyribonuclease I (DNase I) which is normally produced by the pancreas and salivary glands. Hydrolyses proteins in bronchial mucus to improve fluidity

Briefly explain what neonatal respiratory distress syndrome is, what the general treatment strategies involve and how cortisone and exogenous surfactants solve the problem. 

Also known as hyaline membrane disease, occurs in premature babies. Surface active agent (surfactant, which covers airways and is essential for gaseous exchange), is only formed shortly before birth, disrupted gas exchange, lungs may therefore collapse and can result in death. The surfactants are administered exogenously at room temperature (by means of a catheter into the lungs), prophylactically, or during acute respiratory distress syndrome to the neonate to augment lung surfactant. Eventually, the mortality and long-term oxygen requirement are lowered.

What is the role of oxygen therapy in neonatal respiratory distress syndrome?  What do the dangers of oxygen toxicity involve?

Oxygen (mixed with air at room temperature) is administered in order to ensure oxygenation. A continuous positive pressure (as obtained with a ventilator) improves respiration and keeps the alveoli open to prevent collapse. It is critically important that the arterial partial oxygen pressure is continuously monitored. Sufficient oxygen is a basic requirement for normal respiration. Therapeutically it is administered generally to prevent or reverse hypoxia (of various causes)

BUT increased oxygen for long-term leads to retinal damage and blindness. When oxygen is inhaled in excessive quantities and/or over too long a period of time, it has toxic effects. Paradoxically, oxygen toxicity causes, inter alia, reduced gas exchange, hypoxia and, in extreme cases, death. In neonates it can cause retinal damage and blindness.

Briefly explain what neonatal apnoea is and how the methylxanthines solve the problem.  Which methylxanthine is used?

New-born and premature babies: Respiratory centre in brain not yet fully developed to stimulate continuous breathing. Apnoea with bradycardia lasts longer than 15 seconds and occurs repeatedly. May lead to hypoxia and neural damage. Methylxanthine is used to stimulate the CNS, theophylline is used