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RDS is associated with a decrease in pulmonary PL including dipalmitoyl phosphatidyl choline(DPPC) and dipalmitoyl phosphatidyl glycerol (DPPG). In vitro studies have shown these compounds to fuse readily with biologic membranes after the compounds aremixed and extensively sonicated. Previous studies using aerosolized a u r factsnts for treatment of RDS may have been unsuccessful because of failure to add anionic PL to DPPC, failure to sonicate the PL. or failure to administer the material with CPAP.In a pilot study, sonicated DPPCIDPPG(9:l) was nebulized to 13 infants on respirators. In general, the mean changes in A-aDO2 in out'^^ treatment. ahowed a I I1 1208 Alan Jobe and Louis cluck. university of California, San Diego, Department of Pediatrics, La Jolla. Premature and term newborn and adult rabbit lungs were pulse labeled in vivo with leclthin precursors chol ine, palmltic acid, and phosphate. Lecithin was isolated from parenchyma, alveolar wash, lamellar bodies and microsomes from the lungs of each group of animals. Time of appearance and biological half-life of lecithin in each fractlon was monitored bv chanaes in lecithin specific activity with time. All animais rapidly incorporated isotopic precursors into microsomal lecithin. Radioactive leclthln appeared after a 3 hour delay in premature and term newborn lamellar bodies; no delay was noted in appearance of labeled lecithin in lamellar bodies Isolated from adult lung.Ibximal specific activity in alveolar leclthin was reached by 6 hours in adult rabbits and in about 20 hours in premature and term newborns. Biological half-1 ife values for lecithin in the lung fractions of premature and term newborn rabbits were greater than 3 times longer than comparable half-life values determlned for the adult. The long delay (3 hours) before de novo synthesized lecithin begins to reach the alveolar s p a c h s G s t s that synthesis does not contribute to alveolar stability until many hours after blrth. Slgnlficant lecithin synthesized & novo is not present at the alveolar space of the newborn for at least 20 hours. Premature and term newborn rabbits must rely on lecithin stored in anticipation of birth to maintain alveolar stability at birth. The prolonged half-life argues against lecithin degradation contributing to RDS. They improved thei r VM endurance 51.6i 18.8 % (Pc 0.02). Seven CF subjects, with mean FEVl 67i13 % predicted, participated in a 4-week physical activity training program consisting of It hours/day of swimming and canoeing, without specific VM training. They increased their VH endurance 56.7i26.7 $ (P <0.005). However, four normal subjects, on the same specific VM training program, increased their VM endurance only 22.1i7.3 % (P<0.005).The increased response of the CF subjects to training suggests el ther that they had reduced VM endurance initially, or that the training program superimposed on their increased respiratory load was a greater training stress. We conclude from these results that VM endurance can be rapidly improved in CF patients.Fur...

Although delayed micturition in the immediate newborn period is ofter a normal physiologic variation it may be associated with pathological states leading to a decrease in urine formation or reduction of urine flow. Recently, 5 newborns subjected to severe perinatal stress were seen, who exhibited delayed micturition despite adequate urine formation and no evidence of gross anatomic abnormalities. These patients presented with distended bladders that could be maneuvered easily by Credé's method. We believe that these cases represent a heretofore undescribed asphyxiated bladder syndrome and suggest consideration of such a diagnosis when bladder distension occurs subsequent to an asphyxial event. In male newborns it is important to differentiate this syndrome from posterior urethral valves and if urine is not expressed easily one should consider early intervention with diagnostic studies and, perhaps, suprapubic drainage.

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We treated s i x 120-day gestational age lambs w i t h 100 mglkg o f Dosages o f I . V . gentamicin (G) seek t o maintain peak serum AS, a 9:l mixture o f '"C-labeled saturated phosphatidylchol i n e l e v e l s o f 4-12 mcqlml. Recommendations are t h a t pre-dose (PrD) (SPC) and phosphatidylqlycerol, minimal surface tension (ST) 3.6 l e v e l s remain below 2 mcqlml t o avoid n e~h r o t o x i c i t v . We obtained i.1.3 dyneslcm. I n the-1st h r o f l i f e , pH and pCO2 i n AS lambs were s i m i l a r t o those of untreated lambs (UL), while p02=60?9 f o r AS lambs vs p02=25+2 f o r UL (pc.01). A l l lambs were treated w i t h 3H-labeled sheep natural surfactant (NS), ST=O. At treatment a l l 1 ambs had : pH=6.92+0.03; pC02=109k6 mmHg . The 1 ambs responded s i m i l a r l y t o NS; pH, >7.25 and pC02, <55 mmHg. However, p02 remained >I00 mmHg f o r 2.5i.5 h r i n lambs previously treated w i t h AS vs 0.9k.3 h r i n the other lambs (p<.01). The changes i n the 3H and I 4 C s p e c i f i c a c t i v i t i e s (CPMl~mole SPC) recovered by alveolar wash a t s a c r i f i c e suggest t h a t more than 50% o f the AS was no longer associated w i t h the airways. Airway samples taken from AS lambs before treatment w i t h NS had ST=32+2.9, while reisolated material from these samples by c e n t r i f u g a t i o n had ST=O. Usinq an ST increase t o >lo, AS i s 10 times more sensitive t o i n h i b i t i o n by f e t a l lung f l u i d than NS (pc.01).AS restored the pressure volume curves (PV) o f surfactant depleted a d u l t r a t lungs, but AS d i d not improve the PV o f premature lamb lung while NS caused l a r g e PV changes (pi.01).I n summar,y: 1) AS a f f e c t s the p02 r esponse o f lambs. 2) AS seems t o be r a p i d l y cleared from the a i rways. 3) AS i s more s e n s i t i v e than NS t o i n h i b i t o r s o f ST. 4) Premature 1 unas respond d i f f e r e n t 1 y t o AS than a d u l t lungs. Recent studies suggest that dry S promotes lung expansion in preterm rabbits. We tested 75% dipalmitoyl phosphatidyl choline/ 25% dipalmitoyl phosphatidyl glycerol in lambs with RDS ventilated by a pressure-limited respirator at 25 cm peak airway pressure, 5 cm PEEP, 30 breaths per minute, 1:l inspiratory :expiratory ratio and Fi02 0.8. Group I (n=10) received 12 mgslkg dry S into the trachea during a constant inflation pressure of 50 cm for 60 seconds. Group I1 (n=6) was treated with constant pressure and no S, and a control group (1134) N. Ireland. Many s t a t i s t i c a l parameters have been used t o quantify NHRV, b u t l i t t l e comparison has been made of t h e i r r e l a t i v e a b i l i t y t o p r e d i c t the i n f a n t ' s c l i n i c a l course. I n t h i s study seven previously described parameters o f short term v a r i a b i l i t y (STV) and f i v e o f long term v a r i a b i l i t y (LTV) were computed from 2225 hrs o f electrocardiogram from 101 i n f a n t s aged 1-72 hours. ADMINISTRATION OF DRY SURFACTANT(S) UNDER PRESSURE TO PRETERM LAMBS WITH RESPIRATORY DISTRESS SYNDROME ...