Neutrophil recruitment as a factor limiting injury or promoting recovery from acute lung injury.

We studied 1) neutrophil mobilization in sheep given endotoxin (10 ng.kg-1.min-1, n = 5) for 4 h, 2) surviving (n = 17) and nonsurviving sheep (n = 8) during a 12-h infusion of endotoxin, and 3) adult sheep (n = 8) or lambs (n = 8) infused with endotoxin for 12 h. Bone marrow cells of sheep declined from a baseline value of 10,533 +/- 1,784 to 5,966 +/- 1,980 cells/microliter (P < 0.05) 4 h after endotoxin. After 12 h of endotoxin infusion, circulating neutrophils remained reduced from baseline values of 2,000-4,000 cells/microliter to 343 +/- 70 in lambs and 484 +/- 236 in nonsurviving sheep, while beginning to recover in surviving sheep to 1,838 +/- 467 cells/microliter. In lambs and nonsurviving sheep, a 12-h infusion of endotoxin increased lung lymph protein clearance tenfold compared with a fivefold increase in surviving sheep. Neutrophils cultured from sheep bone marrow exposed to lamb postendotoxin plasma failed to increase in cell number (609 +/- 229 to 610 +/- 182 cells/microliter), whereas similar cells exposed to adult sheep postendotoxic plasma showed a significant increase in cell number (1,069 +/- 101 to 2,293 +/- 448 cells/microliter, P < 0.05). Our results are consistent with the hypothesis that the ability to recruit neutrophils to the circulation during periods of inflammation is important in limiting the severity of acute lung injury.

The timing of SIDS deaths in premature infants in an urban population.

Previous reports have demonstrated that premature infants are at greatly increased risk for sudden infant death syndrome (SIDS). Although only 9% of infants are born at less than 36 weeks' gestation, 20% of SIDS victims are former premature infants. The objective of this study was to characterize the time course of SIDS in premature infants and to determine why SIDS occurs at such a high rate in this patient population. A database of all cases of SIDS in Philadelphia from 1987 through 1991 was used to establish the time course for SIDS deaths in term and preterm infants. Gestational age was established by Dubowitz exam. To evaluate distinctly different age groups, infants from 32-36 weeks were excluded from analysis. Age at death and postconceptional age of death were compared for both groups. Data are described in weeks (mean +/- SEM), and analyzed using unpaired t-test and log-rank test to compare survival rate between term and preterm infants. A significant difference (P < 0.01) was noted in age at death of term versus preterm infants. No difference was found in postconceptional age of death. The survival rates were also different (P < 0.001). Preterm infants showed a much wider distribution in age of death from SIDS. The term infants followed the classic SIDS curve. By 32 weeks' postnatal age, 95% of all SIDS had taken place in the term group, but only 75% in the preterm group. The age at death for SIDS differs in the preterm infant.(ABSTRACT TRUNCATED AT 250 WORDS)

Recent advances in parenteral nutrition.

With the modifications described in this article, some of the precise elements in parenteral nutrition have been elucidated. With these changes, this form of nutrition has provided the essential calories and trace elements necessary for very-low-birthweight infants, as well as infants who have required surgery. As further research is done in this area, it is anticipated that even more adjustments to parenteral nutrition will be made, in order to provide optimal caloric vitamin, and trace element intake and establish the optimal manner in which these are administered.

Sugar and fat: sensory and hedonic evaluation of liquid and solid foods.

Twenty-five subjects evaluated the sweetness, creaminess and fat content of liquid and solid dairy products containing between 0.1 and 52 g fat/100 g and sweetened with 0-20% sucrose weight/weight. Liquid stimuli included skim milk, whole milk, half and half, and heavy cream, while the solids included cottage cheese and cream cheese, blended and spread "jelly-roll" fashion on slices of white bread. The subjects' ratings of stimulus sweetness, creaminess, and fat content differed sharply between liquids and solids, and the assessment of fat content of solid foods appeared to be impaired. In contrast, acceptability ratings for both sets of stimuli were not substantially different: the subjects optimally preferred equivalent levels of sugar in both liquids and solids, but selected higher fat levels in solid than in liquid foods. Sensory preferences for fat in liquid stimuli may not always be indicative of preferences for fat in solid foods.