No abstract
San Francisco Endogenous o p i a t e s a r e involved i n a d u l t c i r c u l a t o r y responses t o s t r e s s and may function by decreasing s e n s i t i v i t y of n i c o t i n i c receptors (Nature 283:489, 1980). To examine t h e i r r o l e i n the f e t u s , we studied the h e a r t r a t e (HR) and mean a o r t i c pressure (MAP) responses t o maternal hypoxemia i n 5 nonnoxic (N:pO2>2OmmHg, pH27.38) and 5 chronically s t r e s s e d f e t u s e s (S:pOe2OmmHg spantaneously f o r > 24 hours) a t 120-130 days g e s t a t i o n . and were s i m i l a r during c o n t r o l recordings i n both groups. H R decreased (p<0.001, ANOV) and MAP increased (p<0.001, ANOV) i n response t o hypoxia i n a l l animals. I n N f e t u s e s during hypoxia, naloxone (Nx: 1 mgfkg) increased MAP from 55f4 t o 61f4 (~~s E M , p<0.001, ANOV) i n the 5 minutes following i t ; but H R did not c h a n g e . I n t h e s t r e s s e d f e t u s e s during hypoxia, Nx did not change MAP but decreased from 161f12 t o 140213 (p<0.001, ANOV). . Blood pH f e l l 0.09f0.03 and 0.1f0.02 u n i t s following Nx i n t h e N and S f e t u s e s respectively (p<0.005, paired t -t e s t ) .The Nxinduced r i s e i n i n t h e N f e t u s e s i s consistent with increased vasoconstriction due t o p o t e n t i a t i o n of sympathetico-adrenala c t i v i t y and a balanced parasympathetic-sympathetic e f f e c t on HR. The lack of a response t o Nx i n the S f e t u s e s suggests exhaustion of s y m p a t h e t i c~~a d r e n a l output which unmasks the parasympathetic e f f e c t on HR. These data i n d i c a t e t h a t endogenous o p i a t e s a r e involved i n HR and MAP c o n t r o l i n utero, and a r e c o n s i s t e n t with a Nx f a c i l i t a t e d increase i n ganglionic transmission. (Supported i n p a r t by NIH grant HL00756-01.) IS THERE REALLY A GENTAMICIN DOSE SCHEDULE FOR 344 NEONATES? M. Leitner, L. Steddum, A. Sola, C. Kapadia, J. Gershanik, (Spon. by G. Gregory), Southern B a p t i s t Hospital, Department of Neonatology, New Orleans Recent evidence suggests t h e need t o modify t h e gentamicin (G) dose regimen f o r neonates. To determine t h e appropriate drug schedule we measured 587 gentamicin serum l e v e l s (G.S.L.) on 150 neonates, (G.A. 25-43 wks. and B. W. 680-4820 qms.) admitted t o our NICU. When we used t h e standard dose of 2.5 mg/kg q 12 H our r e s u l t s during t h e f i r s t 2 days of l i f e revealed trough l e v e l s 7 2 ug/ml i n 53.6% (42/78), suggesting possible G accumul a t i o n , and peak 1evels)E ug/ml i n 18% (14/78) a n d L 4 ug/ml i n 10% (8/78). W e then modified t h e i n i t i a l dose regimen according t o g e s t a t i o n a l age:(30 wks., 1.5-2.0 mg/kg q 24 H; 30-37 wks., 2.0-2.5 mg/kg q 18 H; a n d 2 3 7 wks., 2.0-2.5 mg/kg q 12 H. Subsequent r e s u l t s showed a marked decrease i n babies withe e l evated trough l e v e l s (~2 ug/ml) t o 16.6% (12/72). Peak l e v e l s 7 8 ug/ml decreased t o 6.8% (5/72). However, peak l e v e l s 4 4 ug/ m l increased t o 27% (20...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.