Alberto Orzali

Effect of Carnitine on Lipid Metabolism in the Newborn

The effect of carnitine administration on neonatal lipid metabolism was studied during endovenous loading with Intralipid (1 g/kg body weight over a 4-hour period). During a 6-hour period the plasma level of triglycerides, glycerol, free fatty acids (FFA), beta-hydroxybutyrate (beta-OHB), and acetoacetate were monitored in a group of newborns infused with carnitine and compared with a control group infused only with Intralipid. Carnitine administration caused an increased plasma concentration of ketone bodies, probably consequent to an increased rate of FFA mitochondrial beta-oxidation. An increased plasma level of glycerol and FFA was also observed, whereas the triglyceride plasma levels were not different between the two groups. Carnitine administration in the neonatal period seems to act by increasing ketogenesis and lipolysis.

Effect of carnitine on lipid metabolism in the neonate. II. Carnitine addition to lipid infusion during prolonged total parenteral nutrition

The effect of carnitine administration on lipid metabolism and carnitine and acylcarnitine plasma values of newborn infants, given total parenteral nutrition for the first 7 days of life, was studied during a 4-hour infusion of Intralipid. An increase in plasma concentrations of total carnitine, free carnitine, and short-chain and long-chain acylcarnitine was found, but no significant change in triglycerides, free fatty acids, glycerol, or beta-hydroxybutyrate plasma values was noted, as compared with values obtained without carnitine administration. Moreover, the low free carnitine and short-chain and long-chain acylcarnitine plasma levels found in newborn infants after 7 days of total parenteral nutrition did not seem to impair the utilization of infused lipids. The results support the concept that the relation between the carnitine pool and lipid metabolism can be influenced by intravenous glucose infusion. Low carnitine plasma concentrations do not necessarily signify a depletion of body carnitine, and sufficient tissue carnitine concentrations can probably maintain good lipid utilization for an extended period.

Simultaneous Measurement of the Rates of Appearance of Palmitic and Linoleic Acid in Critically Ill Infants

Lipolysis has been measured in humans by means of stable isotope techniques using labeled palmitic acid (PA) or glycerol as tracers. If other fatty acids(FA) such as linoleic acid (LLA) have the same rate of appearance(Ra) as PA and therefore contribute equally to oxidative and nonoxidative metabolism is unknown. We infused albumin-bound [U-13C]PA and [U-13C]LLA in seven critically ill infants (weight 3.6 ± 1.3 kg, age 57 ± 64 d) receiving 20.9 ± 5.4 kcal· kg-1·d-1 of i.v. glucose only, and measured simultaneously the Ra of PA and LLA from the isotopic enrichment of plasma FFA by mass spectrometry. A needle biopsy of the s.c. adipose tissue was obtained for FA composition. PA in adipose tissue was higher than LLA (40 ± 6.7 versus 5.4 ± 3.2 mol%,p < 0.001). The Ra values of PA and LLA were 5.73 ± 2.79 and 1.34 ± 0.92μmol·kg-1·min-1, respectively (p = 0.005). However, the ratio of the FAs Ra to their respective mol% values in adipose tissue was lower for PA than for LLA (0.15 ± 0.06 versus 0.25 ± 0.06, p = 0.02). TheRa of LLA acid was higher than could be expected from the FA composition of adipose tissue, thus indicating a preferential release of LLA during lipolysis. In critically ill infants receiving only i.v. glucose, the contribution of LLA to the oxidative and nonoxidative metabolism may be larger than what assumed from the FA composition of plasma and adipose tissue.

Carnitine and the Premature

After birth, the main energy fuel for the newborn is constituted by fat. Carnitine is necessary for the beta-oxidation of long chain fatty acids at the mitochondrial level, and seems also to have a role in the metabolism of the branched-chain amino acids, in ammonia detoxification, and in urea production. Colostrum is particularly rich in carnitine whereas semi-elemental formulae and soy-based formulae contain little or no carnitine. Since the newborn has a low capacity for carnitine biosynthesis, it seems useful to administer L-carnitine to infants on total parenteral nutrition, soy-based or semi-elemental formulae.

Bilateral diaphragmatic paralysis

Bilateral diaphragmatic paralysis is a rare condition in clinical practice due to different entities that can damage phrenic nerve. The resulting respiratory compromise requires medical special care. This is the first case reported in our medical literature caused by multiple cervical hernias. A 43 year-old patient having health history, high performance ex -athlete, admitted in the service with 5 -month evolution of dyspnea which progressively increased in i ntensity up to maintain him in permanent orthopnea, thorough studies were conducted to the definite diagnosis and he was transferred to Neurosurgery Service to a definite solution. A rare presentation of a bilateral diaphragmatic paralysis resulting from m ultiple cervical hernias gives importance to the topic. DeCS: Bilateral diaphragmatic paralysis, phrenic nerve, cervical hernias

Different Release of Palmitic (PA) and Linoleic (LA) Acid from Adipose Tissue(AT) in Infants with Sepsis 57

Different Release of Palmitic (PA) and Linoleic (LA) Acid from Adipose Tissue(AT) in Infants with Sepsis 57

624 GROWTH PROGRESS OF LOW BIRTH WEIGHT INFANTS FED WITH A SENIELEMEN- TAL, ADAPTED AND SPECIAL-FOR-PRETERN-INFANTS FORMULA

The ideal feeding for preterm infants, is not as yet a resolved problem. Our group has studied the variations of glucose, triglyceride, total protein, pH, BUN, osmolality plasma values, urine osmolality, growth and skinfold thickness of three groups of ten AGA premature newborns (e.g. from 30 to 33 week) alimented with the same caloric regimen of 120 Kcal/kg/day with an adapted foriula (NANRFl), a special-for-preterm-infants-formula (AlpremRF2) and a casein hydrolysate formula (PregestimilRF3). The biochemical and auxological parameters were weekly studied until the babies reached a weight of 2100 gm. The growth with Fl and F2 was respectively 29,4 and 33,4 gm/day, but only 22,9 gm/day with F3.Significant differences were found only between triglyceride plasma values of F3 in comparison with F2 and F1, probably due to the different lipidic composition of F3 formula (only vegetable lipids in addition to MCT).1 wk 57.8± 31.2 vs 75.5±22.6 (N.S.) and 111.3±35.3 (p < 0.05) mg/dl2 wk 40.8± 20.9 vs 96.5±51.9 (p < 0.05) and 105.8±37.3 (p < 0.005) mg/dl3 wk 40.0± 14.9 vs 111.3±52 (p < 0.025) and 138.8±27.9 (p < 0.001) mg/dl4 wk 51.0± 14.3 vs 120.5±36.4 (p < 0.01) and 135.4±57.8 (p < 0.02) mg/dlIn conclusion F3 formula should be used only when specific indications exist.