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Biomedical subjects

J A Lemons

Publications and source records attributed to J A Lemons.

At least 91 records · Page 5Linked to original sources
PubMed1982

The relative efficacy of four methods of human milk expression.

In view of the current trend toward increased breast-feeding, both of normal term infants as well as sick or premature infants, a successful means for milk expression in order to establish and maintain lactation is of major importance to the mother. The present study was designed to evaluate four methods of milk expression, measuring the amount as well s the fat content of milk expressed by each method during a 10-min period. The four methods included the Egnell electric pump, the Loyd B pump, the Evenflo system, and manual expression. The electric pump enabled mothers to express significantly more milk with adequate fat content during the expression period than any of the other methods tested. No significant differences were found between the other three methods. The Egnell or similar electric pump may be a preferred method for milk expression for some mothers, particularly those anticipating a prolonged need for pumping.

Dietary Fats↗
PubMed1982

The energy content of infant formulas.

The reported energy content of infant formulas will vary, depending upon the method used to calculate or measure the caloric value. Manufacturers' specifications regarding the energy content of milk formulas reflects the 'metabolizable' energy. i.e., the amount of energy which is digested and absorbed by the infant. However, estimates of absorptive efficiency are based primarily upon studies in young adult subjects fed mixed diets and therefore may not be generally applicable to all neonates. The actual caloric content of formulas may be determined accurately by bomb calorimetry which is not influenced by the relative metabolic efficiency of the infant who may utilize the formula. Therefore, it may be preferable to express the caloric value of milk base formulas in terms of absolute combustible energy.

Calorimetry↗
PubMed1982

Evaluation of a system for continuous neonatal blood pressure monitoring.

The purpose of this study was to determine the effects of varying infusion rates as well as different catheter sizes and types on the mean arterial pressure as measured by a system in which the pressure transducer is connected in series to the line of fluids being administered through the catheter. The results of this study show that, under most circumstances, errors in mean blood pressure measured by this system are minimal and clinically insignificant.

Blood Pressure Determination↗
PubMed1982

Effects of exogenous glucagon on concentrations of glucose, fructose and insulin in plasma of sheep fetus.

Exogenous glucagon infused into the fetal sheep resulted in an increase in the concentration of glucose and insulin in fetal arterial plasma without a significant change in the concentration of fructose. Lack of any significant changes in glucagon, insulin, glucose and fructose concentrations in maternal plasma suggests that the alterations in the fetus are secondary to fetal metabolic and hormonal mechanisms rather than reflecting effects of maternal metabolism.

Animals↗
PubMed1982

Differences in the composition of preterm and term human milk during early lactation.

The composition of human milk from mothers delivering prematurely (PT) and at term (T) was studied over the first weeks of lactation. Complete 24 h milk expressions were obtained by electric pump at weekly or biweekly intervals through 44 wk conceptual age (120 samples from 20 PT mothers and 28 samples from 7 T mothers). PT milk was found to contain significantly higher concentrations than T milk of the following nutrients: total nitrogen, protein nitrogen, sodium, chloride, magnesium and iron. No differences were found between T and PT milk for nonprotein nitrogen, volume, solids, total calories, lactose, fat, fatty acids, potassium or calcium. The nutrients supplied to a 33 wk preterm infant fed 200 ml/kg/day of "average" PT milk were in excess of theoretic intrauterine requirements for all substrates except calcium and phosphorus. PT human milk is theoretically more suitable for the premature infant than either mature or term human milk, but may be deficient in specific nutrients for the very low birth weight baby.

Calcium↗
PubMed1982

Formulas and human milk for premature infants: a review and update.

New methods of feeding low-birth-weight infants have been developed as a result of improved knowledge concerning the nutritional requirements of the premature infant. Breast milk may offer certain nutritional and non-nutritional advantages for immature babies. Preterm milk is theoretically more appropriate than term or pooled mature breast milk. However, some nutrients may be inadequate to support intrauterine rates of growth in small premature infants. New formulas specifically designed for preterm babies appear to be safe and to promote improved weight gain, fat absorption, bone mineralization, and nitrogen retention. Nutritional needs of growing preterm infants are better met by preamture formulas than by formulas designed for term babies.

Cystine↗
PubMed1982

Nutritional outcome of 207 very low-birth-weight infants in an intensive care unit.

Growth and feeding outcomes during the first weeks of life were prospectively evaluated in 207 critically ill, very low-birth-weight (VLBW) infants (birth weight less than 1,500 gm). Maximal weight loss occurrd by day 9, averaging 13 percent of birth weight, while birth weight was regained by day 18. Energy intake during initial weight gain (19 gm. per day) averaged 100 kcal per kilogram. Feeding and growth outcome were highly correlated (p of less than 0.001) with severity of illness but were not significantly related to sex, birth weight, or appropriateness of weight for gestational age.

Female↗
PubMed1981

Metabolic and hormonal response to chronic maternal fasting in the ewe.

The purpose of this study was to investigate the metabolic adaptations of the fetus during maternal starvation and to determine the changes of plasma insulin and glucagon concentrations in the fed state and during severe maternal fasting in the chronic fetal sheep preparation. Maternal fasting resulted in a decrease in maternal and fetal plasma glucose as well as a decrease in fetal plasma fructose. Fetal-maternal arterial urea concentration differences increased with maternal fasting, suggesting increased fetal amino acid catabolism. Both maternal anf fetal plasma insulin decreased parallel to the decrease in plasma glucose concentration. Maternal glucagon did not change significantly during fasting and with a short-term fast there was no change in fetal glucagon concentration. However, by 6 days of fasting, the fetal glucagon concentration tended to increase.

Animals↗
PubMed1981

Effect of acute nonsurgical stress on fetal and maternal plasma glucose, glucagon and insulin concentration in sheep.

The purpose of this study was to investigate the effect of nonsurgical stress on plasma glucose, insulin and glucagon in the ewe and fetus. Plasma glucose, insulin and glucagon were measured before and after a 2 min period of verbal and physical startling of much greater magnitude than that to which we ewe is exposed during routine blood drawing. Studies were completed on 5 fed ewes, 5 fasted ewes and on 4 fetuses of fasted ewes. There were no significant differences after a startling compared to the control values. Thus, there appears no need to allow the ewe a prolonged period (more than 1-2 weeks) to become accustomed to handling by humans before chronic metabolic studies involving serum glucose, insulin and glucagon are undertaken.

Animals↗
PubMed1981

Controlled study of transpyloric and intermittent gavage feeding in the small preterm infant.

There were 53 appropriate for gestational age infants with a birth weight of less than 1,700 gm admitted to the Children's Hospital in Denver who were randomly assigned to two groups for gavage or transpyloric (nasojejunal) feedings. The two groups were not significantly different in terms of gestational age, birth weight, and morbidity. No significant differences were observed for caloric intake after 4 days of age, growth parameters (weight, length, and head circumference), serum total protein levels, feeding-related complications, duration of intravenous fluid supplementation, and length of hospitalization. The results indicate that intermittent gastric gavage feedings are as efficacious as transpyloric feedings in supplying nutrition to the low birth-weight infant. Because of inherently greater risks, costs, radiation, and requisite personnel expertise, transpyloric feedings cannot be recommended as a routine method of feeding for the low birth-weight infant.

Birth Weight↗
PubMed1981

Infant of the diabetic mother: review of 225 cases.

The maternal and neonatal data on 225 infants of diabetic mothers (IDM) are presented. The incidence of maternal and neonatal complications confirms previous reports, indicating improved survival rates and decreasing neonatal morbidity for the IDM. The observed incidence of hyaline membrane disease was 2.8%, perhaps reflecting attempts to prolong pregnancy when possible to 39 weeks' gestation with judicious use of primary cesarean section. Further, from analysis of neonatal growth, the head circumference of the large-for-gestational-age infant was found to be significantly increased after 37 weeks' gestation. Whether or not this observation represents increased brain growth in these infants is not known.

Birth Weight↗
PubMed1980

An analysis of tolazoline therapy in the critically-ill neonate.

There were 47 seriously-ill neonates with medical causes of respiratory distress and 10 infants with severe respiratory distress secondary to a congenital diaphragmatic hernia treated with tolazoline according to a strict protocol designed to manage persistent fetal circulation (PFC). Of the 47 infants, 28 (60%) had a positive response defined as an increase in the pO2 greater than or equal to 24 mm Hg within 4 hr of beginning the drug. Of 7 infants, 4 with congenital diaphragmatic hernia had a positive response. The mean increase in the pO2 for the 47 infants was statistically significant (p less than .05). Of the 47 infants with medical disorders, 27 survived (survival 57%), whereas only 2 of the 10 infants with congenital diaphragmatic hernia and severe persistent fetal circulation survived (survival 28%). Erythema (60%), hematest positive gastric aspirates (55%), thrombocytopenia (45%), hyponatremia (40%) and increased gastric aspirates (36%) were the most common adverse effects occurring during tolazoline infusion. Hypotension occurred in nine cases, but was transient. Of the 27 survivors, 20 with medical causes of persistent fetal circulation were evaluated at age 1 yr. Eighty percent of these infants studied were considered normal as defined by an MDI and PI of the Bayley Scales of greater than or equal to 70. These data suggest that tolazoline is a useful adjunct in the management of neonates with PFC. In addition, tolazoline was more effective in mechanically ventilated neonates treated with respiratory paralytic agents. Although tolazoline resulted in a significant improvement in the paO2 in 4 infants with congenital diaphragmatic hernia, it did not appear to improve mortality in these infants.

Erythema↗
PubMed1980

Acute small animal preparation--suitable for fetal metabolic studies?

To determine the immediate effects of the "acute" experimental preparation, 11 near-term pregnant rabbits and 20 fetuses were studied. Blood samples were obtained from the maternal auricular artery, the fetal umbilical vein, and the fetal heart within 90 s of exposure of the uterus by laparotomy. Samples were assayed for pH, O2 and CO2 tension, O2 content, blood urea nitrogen, and plasma glucose. Results indicated that a pronounced fetal acidosis (primarily respiratory) had developed by the time samples were obtained. Further, fetal cardiac glucose levels were significantly elevated above umbilical vein concentrations in 7 of the 20 fetuses. In addition, maternal arterial O2 tension under light pentobarbital anesthesia was significantly less than that found in 35 unanesthetized does (52 vs. 79 Torr, P less than 0.01). All parameters measured varied over a wide range between animals. The results raise serious questions concerning the feasibility of performing and interpreting certain metabolic or cardiorespiratory studies in the acute small animal preparation.

Animals↗