239 Decrease in Α- Adrenergic Binding Sites in Newborn Platelets: Cause of Abnormal Response to Epinephrine?

Abstract

RESULTS: From 9/74 t o 9/77 a t o t a l o f 637 f u l l t e r m IDDM weighi n g a t l e a s t 2268 g were d e l i v e r e d . U s i n g t h e c r i t e r i a p r e v i o u s l : r e p o r t e d , t h e s e v e r i t y o f n e o n a t a l d r u g w i t h d r a w a l was assessed: 89% (5641637) had minor t o m i l d (MM) and 12% (731637) moderate tl severe (MS) w i t h d r a w a l . Two p e r c e n t (141637) were l a t e r r e p o r t e d t o have d i e d o f SIDS. A s i g n i f i c a n t l y h i g h e r number o f i n f a n t s w i t h MS (6173) d i e d o f SIDS compared t o t h o s e w i t h MM w i t h d r a w a l (8/564), X2=9.060, pc0.01. Those who d i e d had no s i g n i f i c a n t med. i c a l problems d u r i n g t h e n e o n a t a l p e r i o d . A l l d i e d between 4-16 weeks of age: 57% i n Winter, 21% i n Summer and 21% i n t h e F a l l . CONCLUSION:1) The frequency o f SIDS i s h i g h e r among IDDM comp a r e d t o t h e g e n e r a l p o p u l a t i o n . 2) A s i g n i f i c a n t l y h i g h e r i n c idence o f i n f a n t s w i t h MS w i t h d r a w a l d i e d from SIDS compared t o t h o s e who had l e s s e r degrees o f w i t h d r a w a l . 3) Since t h e r e i s a c o r r e l a t i o n between m a t e r n a l methadone dose and s e v e r i t y o f neon a t a l w i t h d r a w a l ( J P e d i a t , A p r i 1 / 7 6 ) , t h e use of l o w methadone dosage d u r i n g pregnancy i s s t r o n g l y recommended. PHARMACOKINETICS OF AMIKACIN I N CHILDREN WITH MALIG-NANCIES. Thomas Cleary, L a r r y K. P i c k e r i n g , Steven J. C u l b e r t , W i l l i a m Kramer, Steve Kohl, S t u a r t F e l dEys (Spon. b y R. Rodney Howell). The Univ. o f Tex.Med. School, D e~t . I n f . D i s . & P e d i a t r . . The Univ. of Tex. Svstern Canc. ~t r .,' Dept. P e d i a t r . , The ~n i v . o f Houston, Dept. -Pharm., Houston, Texas. Amikacin i s an aminoglycoside a n t i b i o t i c t h a t i s e f f e c t i v e a g a i n s t gram n e g a t i v e b a c i l l i which a r e r e s i s t a n t t o o t h e r aminoglycoside a n t i b i o t i c s . S i x and 8 hour serum c o n c e n t r a t i o n s were 1.27f1.26 and 0.6420.92 ~g / m l , r e s p e c t i v e l y .The t% was +43.8 minutes and t h e t o t a l c l e a r a n c e was 133t43 ml/min/1.73The A 9% i n a c t i v a t i o n o f a m i k a c i n o c c u r r e d when i n c u b a t e d i n normaldonor s e r a a t 3 7 O~ f o r 72 hours w i t h v a r y i n g c o n c e n t r a t i o n s of t i c a r c i l l i n .Due t o t h e r a p i d r e n a l c l e a r a n c e and s h o r t h a l f l i f e o f a m i k a c i n i n these c h i l d r e n , t h e c u r r e n t l y recommended dose o f amikacin s h o u l d be i n c r e a s e d and t h e frequency of a d m i n i s t r a t i o n shortened.as a primary,drug-related effect of maternal to fetal t r a n s f e r o f morphine s u l f a t e ( M S ) o r whether fetal responses a r e r e l a t e d to a l t e r e d maternal physiology.Four non-pregnant and 4 pregnant ewes were studied. A continuous intravenous ( I V)i...

Deficient Collagen-Induced Activation in the Newborn Platelet

“…This suggests that the Ia/IIa complex is present on neonatal platelets in comparable number to those present on adult platelets. The possibility of decreased numbers of collagen receptors was considered a significant possibility since the number of a-adrenergic receptors on neonatal platelets is markedly decreased, accounting for their minimal response to epinephrine (33). This appears to be an isolated receptor deficiency because the amounts of G P IIb/IIIa and G P Ib have been reported to be normal on the surface of fetal platelets (1 8).…”

Differences in Thromboxane Production between Neonatal and Adult Platelets in Response to Arachidonic Acid and Epinephrine

“…This report is one of a series describing the long-term effects of early malnutrition on the behavioral development of Barbadian school children. The earlier reports in this series demonstrated a modest reduction in IQ among the previously malnourished group (4) and the increased frequency of impaired classroom behaviors, including attention deficit disorder, impaired social skills, emotional instability, and impaired physical appearance (5). These factors resulted in poor school achieve-…”

Arachidonic Acid-Induced Aggregation of Platelets from Human Cord Blood Compared with Platelets from Adults

“…Placental factors with such properties might also be involved [12]. It has also been proposed that receptor defects as well as storage-pool and aspirine-like defects may explain the generally decreased aggregability of platelets from neonates [9,13,14], For example, the high levels of catechol amines in the blood of newborn infants at birth [15] might block epinephrine receptors in the platelets, leading to decreased platelet reactivity. The high concentrations of AA in all lipid fractions in the serum of newborn infants might have a similar effect, prevent ing maximal aggregation from taking place.…”