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The practice of delayed cord clamping (DCC) in premature infants has proven benefit to the neonate. In a community-based perinatal centre, the practice of DCC for more than 60 s for premature infants with gestational age of

Introduction We sought to reduce the incidence of necrotizing enterocolitis (NEC) in premature infants (PI) by fostering the postnatal establishment of protective intestinal bacteria through early administration of human milk (HM) and probiotics. Methods A multidisciplinary team implemented an initiative to support breastfeeding (BF) and provide early postnatal supplemental donor human milk (DHM) and probiotics to PI. Interventions included process improvements in milk preparation, storage, and fortification. PI admitted to our NICU between 2006 and 2015 were monitored for feeding of HM, DHM, and preterm formula (PF), frequency of early feedings, and incidence of NEC. Results Retrospective review of 2557 cases revealed post-initiative increases in the percentage of PI receiving HM (91.5% to 96.1%), HM within 48 hours of birth (75% to 90.6%), and DHM (17.7% to 71.9%). The percentage of infants receiving feedings on day one increased from 23.9% to 44.6% while the percentage receiving PF within the first 72 hours declined (31.2% to 10.3%). The NEC rate declined from 4.1% to 0.4%. Reduction in NEC occurred despite a simultaneous increase in perinatal antibiotic exposure and the universal but late administration of bovine HM fortifier. The improvement associated with the decrease in NEC included initiation of probiotic administration, a reduction in PF feeding, and improvements in milk preparation, storage, and fortification processes. Conclusions Early exclusive feedings of HM and avoidance of PF together with probiotics and milkhygiene may decrease NEC in PI. Neither brief perinatal antibiotic exposure nor late introduction of bovine fortifiers appears detrimental in this context.

OBJECTIVE. The purpose of this work was to assess a quality improvement initiative to implement a potentially better practice, bubble continuous positive airway pressure, to reduce bronchopulmonary dysplasia and improve other pulmonary outcomes among very low birth weight infants with respiratory distress syndrome.METHODS. An initiative to implement the use of bubble continuous positive airway pressure is described that was based on the adoption of habits for change, collaborative learning, evidence-based practice, and process development. To assess the efficacy of this intervention, very low birth weight infants with respiratory distress syndrome born after implementation of bubble continuous positive airway pressure use (period 2: March 1, 2005, to October 4, 2007; N = 126) were compared with historical controls born during a previous period of ventilator use (period 1: January 1, 2003, to February 28, 2005; N = 88). Infants at both time periods were similar with respect to characteristics and aspects of perinatal care. Pulmonary outcomes compared for the 2 time periods included receipt of mechanical ventilation, duration of mechanical ventilation, pneumothoraces, and incidence of bronchopulmonary dysplasia. Nonpulmonary outcomes were also compared.RESULTS. The use of mechanical ventilation declined during period 2. The mean duration (+ SD) of conventional ventilation during period 2 was shorter than during period 1 (3.08 + 6.17 vs 5.25 + 8.16 days), and fewer infants during period 2 required conventional ventilation for >6 days compared with those in period 1 (13.6% vs 26.3%). In regression models, the effect of period 2 persisted after controlling for other predictors of duration of conventional ventilation. There were no significant differences in other pulmonary or nonpulmonary outcomes, with the exception of mild retinopathy of prematurity (stage I or II), which was more common during period 2. The enhanced odds of retinopathy of prematurity persisted after controlling for other known predictors of this condition.CONCLUSION. Among very low birth weight infants with respiratory distress syndrome, the use of bubble continuous positive airway pressure is a potentially better practice that may reduce the use of mechanical ventilation. Although an increase in retinopathy of prematurity was observed in our population, carefully designed randomized, controlled trials will be required to more accurately address the potential risks and benefits of this therapy.

To test the hypothesis that mothers with high self-concept will be more likely to breastfeed their infants than those with lower self-concept, 2 cohorts of mothers of term newborns were assessed by different forms of the Tennessee Self-Concept Scale. In study 1, mothers exclusively breastfeeding at 1 month postpartum had significantly higher self-concept than those exclusively formula feeding. In study 2, exclusively breastfeeding mothers had higher scores for total self-concept compared with those exclusively formula feeding. Exclusively breastfeeding mothers also scored higher on several individual dimensions of self-concept, notably those reflecting self-satisfaction, behavior, moral worth, value as a family member, and physical appearance. Mothers partially breastfeeding had intermediate levels of self-concept in both studies. Even after controlling for demographic and social factors and for breastfeeding initiation in regression analyses, self-concept remained significantly associated with exclusive breastfeeding in both studies. Thus, compared with mothers who exclusively formula feed their infants, exclusively breastfeeding mothers have higher levels of self concept. J Hum Lact. 24(4):431-438.

The early course and antecedents of postpartum anxiety are unknown. This study sought to determine the course and antecedents of maternal anxiety during the first month postpartum and to develop a model to predict 1-month anxiety using information obtainable before perinatal hospital discharge. Two hundred and ninety-six mothers were screened before discharge with the State (SS) and Trait (TS) Scales of the State Trait Anxiety Inventory (STAI). Demographic characteristics were assessed by questionnaire and medical record review, and psychiatric history, measures of perinatal stress, and resilient factors were determined by focused questions and formal instruments. At 1-month postpartum, the SS was repeated. Scores on the SS were significantly higher at 1 month than immediately postpartum (35.30+/-0.68 versus 33.38+/-0.60, mean+/-standard error, P=.004), but only 58.6% of mothers with high pre-discharge anxiety had high anxiety at 1 month. One-month anxiety correlated with pre-discharge SS and TS scores, a history of psychiatric problems including depressed mood, medical and negative social life events, lack of pregnancy planning and prenatal class attendance, perceived peripartum stress, and duration of postpartum hospital stay. Inverse correlations were observed with education, household income, and resiliency factors. In multivariate modeling, anxiety trait, education, history >or=2 years of depression, and perception of peripartum stress accounted for 50% of the variance in the 1-month SS score. Maternal anxiety increases during the first postpartum month. Women with high trait anxiety, low education, a history of depressed mood, and a perception of high peripartum stress are at risk for experiencing anxiety at this time.

Objective: To explore the prevalence and correlates of maternal postpartum anxiety. Methods: 422 of 973 invited mothers (43%) were screened for anxiety before hospital discharge with the State-Trait Anxiety Inventory (STAI). Recent medical and social life events, stress, resiliency (mastery, social support, and marital satisfaction), length of stay, discharge readiness, anticipatory medical care, and history of psychiatric illness and depression were assessed by questionnaire and medical record review. Results: 24.9% of mothers had moderate and 1% severe anxiety. Higher anxiety was observed among young, unmarried, primiparous mothers with male infants, and anxiety correlated with medical and negative social life events, stress, history of depression, and duration of postpartum stay. Inverse correlations were observed with maternal education and household income, pregnancy planning, prenatal class attendance, infant healthcare provider identification, and with all resiliency factors. In multivariate models, pre-discharge anxiety was significantly associated with medical life events and the maternal perception of perinatal stress, and negatively associated with mastery, marital satisfaction, and choice of infant healthcare provider. Conclusion: Moderate maternal anxiety is common prior to perinatal hospital discharge, especially among women with low mastery and marital satisfaction, stressful perinatal courses, and failure to identify an infant healthcare provider.

OBJECTIVE. Our goal was to test the hypothesis that breastfeeding is associated with enhanced infant-mother attachment and its antecedent maternal sensitivity.METHODS. Breastfeeding intent and practice were assessed by questionnaires administered to 152 mothers between 32 weeks of gestation and 12 months postpartum. Early maternal sensitivity was measured by the Sensitivity to Cues subscale of the Nursing Child Assessment Satellite Training Feeding Scale at 3 months, and quality of the mother-infant interaction was measured by the Nursing Child Assessment Satellite Training Feeding Scale at 6 months. Security of attachment was evaluated by the Ainsworth Strange Situation at 12 months.RESULTS. A direct relationship between attachment security and breastfeeding practice was not identified. The quality of the mother-infant interaction at 6 months, rather than the type of feeding, predicted security of attachment. However, mothers who chose to breastfeed displayed greater sensitivity in dyadic interactions with their infants 3 months postnatally than those who chose to bottle feed, and intended breastfeeding duration prenatally correlated with sensitivity 3 months postpartum. Although a path analysis failed to demonstrate contributions of early breastfeeding duration to either sensitivity or security, it did substantiate a significant path between prenatal breastfeeding intent and attachment security mediated by sensitivity. In addition, multivariate analyses revealed that early sensitivity among breastfeeding mothers was an independent predictor of the duration of any and exclusive breastfeeding during the first year.CONCLUSIONS. Although the quality of the dyadic interaction in infancy, rather than feeding type, is predictive of attachment security, mothers who choose to breastfeed display enhanced sensitivity during early infancy that, in turn, may foster secure attachment. Among breastfeeding mothers, higher sensitivity is associated with longer duration of breastfeeding during the first postpartum year. These findings suggest a link between attachment security and breastfeeding.

To evaluate the stability of global maternal satisfaction with perinatal hospital care during the post-partum period and its relationship to anxiety, depression, and stressful medical events, a cohort study of 300 mothers delivering at a university hospital was performed during the first month postpartum. Satisfaction, measured on a 4-point Likert scale (0-3), declined from 2.75 +/- 0.03 (mean +/- standard error) before hospital discharge to 2.48 +/- 0.04 at 1 month postpartum (P = .000), and only 69.5% of mothers very much satisfied predischarge remained so at 1 month (P = .000). Predischarge satisfaction declined with greater medical events (adjusted odds ratio [AOR] = 0.85, 95% confidence interval [CI] = 0.74, 0.97, P < .05) and with concomitant anxiety (AOR= 0.92, CI= 0.89, 0.95, P< .001); reduced satisfaction at 1 month was associated with high anxiety (AOR = 0.97, CI = 0.95, 0.98) and depression (AOR = 0.96, CI = 0.93, 0.99) at that time. Thus, perinatal satisfaction may be time-dependent and associated with contemporaneous medical and psychological changes.

Although evaluation of psychosocial risk factors prior to perinatal hospital discharge has been advocated, the means for accomplishing such an evaluation are not well established. This article reviews several major psychosocial risk factors together with instruments that have been utilized to assess them during the perinatal period. Formal constructs reviewed include anxiety, depression, self-concept, general attitudes, life events, stress, adaptation, social support, marital and family functioning, and the home environment. Ongoing assessment of psychosocial status using formal instruments during routine perinatal care may provide a more complete picture of the psychosocial needs of the individual mother and her family, allowing for more appropriate, timely intervention and utilization of social and health care resources.

With shorter postnatal hospital stays, concern has arisen that many infants may be discharged prior to completion of the transition to extrauterine life, a time of dynamic physiologic change when many neonatal problems may present. This article reviews the physiology of the neonatal transition together with common transitional disorders. Most disorders of transition present at typical postnatal time periods, permitting their timely anticipation and treatment. Moreover, many are associated with factors that may further aid the clinician in defining those infants at highest risk.

Introduction: Neonatal nurse practitioner (NNP) and physician (NCP) use in a community hospital was evaluated to test the hypothesis that NNP avallability would result in changing patterns of NCP attendance at newborn resuscitations. Method: Records were reviewed for consecutive years before (pre-NNP) and after (post-NNP) NNP employment for frequency of NNP and NCP attendance at moderate-, high-, and very high-risk deliveries, together with rates of low Apgar scores and resuscitation guideline compliance. Results: Pre-NNP, NCPs attended 39.5‰ of moderate-risk and 91.6% of high-risk deliveries; these figures fell to 2.1% and 6.0%, respectively, during post-NNP (chi square: df = 1, p < .0001). Post-NNP, NNP attendance at moderate- and high-risk deliveries was 88.6% and 99.2%, higher than NCP attendance during pre-NNP (chi square: df = 1, p < .01). No difference was observed between periods in rates of Apgar scores less than 7 at 5 minutes or the percentage of resuscitations that complied with current guidelines. Discussion: In community hospitals NNPs may be used instead of NCPs for moderate- and high-risk deliveries. They may also be used more than NCPs in the absence of NNPs.

Objective. To provide the pediatric practitioner with a summary of available data regarding the appropriate time of hospital discharge of the term newborn. Methodology. Published series on early discharge were critically reviewed. Results. Heterogeneity and limitations of methodology and study design substantially limit conclusions that may be drawn from published studies. Conclusion. Early discharge recommendations of the American Academy of Pediatrics remain appropriate, and decisions regarding the timing of discharge of the well term newborn should be individualized and made by the practitioner based upon the medical, social, and economic aspects of each case.

Although the Institute of Medicine of the USA has recommended elements for healthcare reform, the optimal means for incorporation of these elements into a healthcare setting remain undefined. A process for the implementation of potentially better practices is described that incorporates a computerized medical record into an evidence-based, multidisciplinary continuous quality improvement effort. Steps in the process include the following: fostering a culture change that incorporates key habits for improvement; identification of a potentially better practice; review of existing evidence and analysis of local experience; delineation of proposed outcomes and potential confounders; guideline formulation and implementation; monitoring of change effectiveness; ongoing multivariate data analyses; and policy formulation. Trainee education and family participation characterize all steps in the process. Consequently, the process incorporates all of the elements recommended by the Institute of Medicine of the USA for healthcare reform and may be adapted to any healthcare setting.

Although difficult infant temperament has been associated with maternal postpartum anxiety and depressed mood in later infancy, the emergence of this association in the early postpartum period has not been explored. In a survey study of 296 mothers of healthy term newborns during the first postpartum month, the relationship of infant temperament with maternal anxiety and depressed mood was explored. Maternal ratings of infant temperament were measured by the Early Infancy Temperament Questionnaire. Postpartum anxiety was measured by the State Scale of the State-Trait Anxiety Inventory and depressed mood by the Beck Depression Inventory. The State Scale and Beck Depression Inventory correlated positively with ratings of infant activity, rhythmicity, approach, distractibility, and overall temperamental difficulty. In addition, the State Scale correlated positively with ratings of adaptability and intensity. In regression analyses, controlling for other factors, ratings of overall temperamental difficulty were independently associated with both State Scale and Beck Depression Inventory scores. Associations of difficult infant temperament with maternal postpartum anxiety and depressive symptoms emerge early in the postpartum period. These associations are independent of other known contributors to postpartum mood.

Background and purpose Femoral impaction grafting requires vigorous impaction to obtain adequate stability without risk of fracture, but the force of impaction has not been determined. We determined this threshold force in a preliminary study using animal femurs. Methods Adult sow femurs were used because of their morphological similarity to human femurs in revision hip arthroplasty. 35 sow femurs were impacted with morselized bone chips and an increasing force was applied until the femur fractured. This allowed a threshold force to be established. 5 other femurs were impacted to this force and an Exeter stem was cemented into the neomedullary canal. A 28-mm Exeter head was attached and loaded by direct contact with a hydraulic testing machine. Axial cyclic loading was performed and the position sensor of the hydraulic testing machine measured the prosthetic head subsidence. Results 29 tests were completed successfully. The threshold force was found to be 4 kN. There was no statistically significant correlation between the load at fracture and the cortex-to-canal ratio or the bone mineral density. Following impaction with a maximum force of 4 kN, the average axial subsidence was 0.28 mm. Interpretation We achieved a stable construct without fracture. Further studies using human cadaveric femurs should be done to determine the threshold force required for femoral impaction grafting in revision hip surgery.

We report the cases of neonatal lupus erythematosus associated with significant hepatic involvement in three living infants and in one infant who died 3 hours after delivery. The three living infants had neonatal cholestasis as a major component of their clinical findings. Pathologic changes included giant cell transformation, ductal obstruction, and extramedullary hematopoiesis. Liver involvement has been noted incidentally in children with neonatal lupus erythematosus, but it has generally been attributed to hemodynamic compromise as a result of congenital heart block or systemic toxic reactions. We speculate that neonatal hepatitis proceeding to hepatic fibrosis may occur in neonatal lupus erythematosus, analogous to the occurrence of "idiopathic" congenital heart block. The neonatal hepatitis associated with neonatal lupus erythematosus is a form distinguishable from the "idiopathic" group. Liver involvement may be more common than was previously recognized, and prospective studies to look for maternal autoantibodies in idiopathic neonatal liver disease should be undertaken.

To evaluate the relationship between postpartum anxiety and lactation experience, knowledge, confidence and performance.State anxiety was measured among breast-feeding women by the State Trait Anxiety Inventory before hospital discharge and at 1 month postpartum. Breast-feeding experience and knowledge were assessed by focused questions and confidence by the Breastfeeding Confidence Scale. Breast-feeding performance measures included breast-feeding immediately after delivery; formula supplementation in the hospital; full, exclusive breast-feeding; and breast-feeding termination at 1 month postpartum.Predischarge anxiety correlated inversely with breast-feeding confidence (r [339] = -0.27, p = 0.000) but not with experience or knowledge. As compared to low-anxiety mothers, those with high anxiety were less likely to breast-feed after delivery (53.0% vs. 65.1%, p = 0.049) and more likely to give their infants formula (43.9% vs. 29.1%, p = 0.022). In logistic regression models adjusting for demographic and social factors, high-anxiety mothers were less likely to practice full, exclusive breast-feeding (AOR = 0.39; 95% CI 0.20, 0.74; p0.005) and more likely to have terminated breastfeeding at 1 month (AOR = 4.40; 95% CI 1.70, 11.33; p0.005).Postpartum anxiety may be associated with reduced breast-feeding confidence and lactation performance. Awareness of this association may be helpful in identifying women at risk for lactation failure and targeting efforts to promote breast-feeding.

To explore the prevalence and correlates of maternal postpartum anxiety.422 of 973 invited mothers (43%) were screened for anxiety before hospital discharge with the State-Trait Anxiety Inventory (STAI). Recent medical and social life events, stress, resiliency (mastery, social support, and marital satisfaction), length of stay, discharge readiness, anticipatory medical care, and history of psychiatric illness and depression were assessed by questionnaire and medical record review.24.9% of mothers had moderate and 1% severe anxiety. Higher anxiety was observed among young, unmarried, primiparous mothers with male infants, and anxiety correlated with medical and negative social life events, stress, history of depression, and duration of postpartum stay. Inverse correlations were observed with maternal education and household income, pregnancy planning, prenatal class attendance, infant healthcare provider identification, and with all resiliency factors. In multivariate models, pre-discharge anxiety was significantly associated with medical life events and the maternal perception of perinatal stress, and negatively associated with mastery, marital satisfaction, and choice of infant healthcare provider.Moderate maternal anxiety is common prior to perinatal hospital discharge, especially among women with low mastery and marital satisfaction, stressful perinatal courses, and failure to identify an infant healthcare provider.

To assess the hypothesis that maternal postpartum behaviors toward the newborn may predict the quality of the maternal-infant relationship during the first year.Prospective, non-randomized, longitudinal cohort study of 174 maternal-infant dyads.A Postpartum Parenting Behavior Scale (PPBS) was formulated to measure clearly defined observed maternal behaviors toward the infant shortly after birth. The quality of the maternal-infant relationship was assessed at 6 months after birth with the Nursing Child Assessment Satellite Training (NCAST) Feeding Scale and at 12 months after birth with the NCAST Teaching Scale and Ainsworth Strange Situation.The PPBS score correlated significantly with the Feeding Scale score (r =.27, P.005) and with the Teaching Scale score (r =.23, P.01). Mothers whose infants were later classified as securely attached in the Ainsworth Strange Situation had higher PPBS scores than mothers of infants classified as insecurely attached (mean +/- SD: 5.18 +/- 1.51 vs 4.63 +/- 1.69, respectively, P.05). In regression models adjusting for social and demographic factors, the PPBS remained a significant predictor of the Feeding Scale score, the Teaching Scale score, and security of attachment.Maternal behaviors in the immediate postpartum period may aid in predicting quality of the maternal-infant relationship during the subsequent 12 months, suggesting the potential for early identification of suboptimal parenting.

Objective. To evaluate the relationship between early perinatal hospital discharge and several parenting outcomes during infancy, including breastfeeding, mother–infant interaction, and mother–infant attachment. Study Design. A prospective, longitudinal, nonrandomized study of mother–infant dyads discharged ≤36 hours after birth (early discharge), compared with those discharged >36 hours after birth (late discharge). Methods. Demographic, perinatal, and psychosocial factors were determined from medical record review and maternal questionnaires. Questionnaires also assessed maternal perceptions of the hospital stay and breastfeeding rates. Mother–infant interaction was assessed at 3 months after birth using the NCAST Feeding Scale and at 9 months after birth using the NCAST Teaching Scale. Security of attachment was measured in the Ainsworth Strange Situation at 12 months after birth. Results. Early and late discharge groups were similar with respect to major demographic, perinatal, and psychosocial characteristics and perceptions of the hospital stay. Even after adjusting for these factors in regression analyses, no significant association was found between early discharge and breastfeeding at 3 months, NCAST scores at 3 and 9 months, and security of attachment at 12 months. Conclusion. Parenting outcomes, such as breastfeeding, mother–infant interaction, and attachment, are not influenced by early perinatal hospital discharge.

Background:Although official guidelines and recent legislation have addressed early postpartum hospital discharge and follow-up, little is known about the practices of obstetricians in Canada and the United States on this issue. Methods: Questionnaires were mailed to two separate random samples of 2000 Fellows of the American College of Obstetricians and Gynecologists (ACOG) in the United States and all Canadian Fellows. Practices and perceptions were compared with those recommended in the literature, recent legislation, and guidelines of ACOG and American Academy of Pediatrics (AAP). Results: In contrast to concerns expressed in the medical literature and official AAP/ACOG guidelines, many physicians considered potential psychosocial and demographic risk factors relatively unimportant in making early discharge decisions, preferring to emphasize aspects of the patient's medical condition, hospital course, and social support. Although the official guidelines encourage follow-up for all patients discharged early, additional visits are routinely advised by only 39 percent of obstetricians after vaginal delivery and by 68 percent after cesarean section. After vaginal delivery 39 percent of obstetricians used telephone follow-up and 37 percent after cesarean delivery. Moreover, although the official guidelines recommend follow-up within 48 hours of discharge, only one-half of the obstetricians surveyed advised follow-up at this time. In contrast to the guidelines, most obstetricians defined early discharge as that occuring within 24 hours after vaginal delivery and 72 hours after cesarean delivery; most defined optimal lengths of stay within the 48-hour (after vaginal delivery) and 96-hour (after cesarean delivery) periods considered short by the guidelines. Conclusions:Current postpartum early discharge and follow-up practices emphasize the physical health of the mother and place little emphasis on social risk. They appear to be influenced by perceptions of the appropriateness of the length of stay and are not in agreement with professional guidelines. (BIRTH 25:3 September 1998)

Many biologically active polypeptides have been described in the milk of several species. Various functions for these polypeptides in addition to nutrition have been proposed in the maternal body and in the breast-fed infant. These polypeptides are derived from several sources and multiple factors control their secretion into milk as well as their fate in the mother and infant. An increasing body of evidence supports the concept that they may function physiologically.

In adult mammals, epidermal growth factor (EGF) is produced mainly in the submandibular and Brunner’s glands1–3. The production of EGF in suckling mammals is considered to be very low. Popliker et a1.4 reported absence of EGF mRNA in suckling mice; others described only very small amounts of EGF to be present in submandibular glands of suckling rodents1,5–7. EGF is known to play an important regulatory role in the mammals; many studies suggest that EGF is a trophic factor for various regions of the developing gastrointestinal tract8–17 and liver18,19.

Lactoferrin, a milk iron-binding protein, may play antimicrobial, iron-absorptive and growth-promoting roles in the developing gastrointestinal tract. To perform such functions, lactoferrin must survive digestive processes in the gut lumen in an active form. We investigated the gastric digestion of lactoferrin in addition to that of the other milk proteins, transferrin and casein, in preterm infants by measuring their degradation during incubation in vitro at 37 degrees C with gastric fluid at pH 1.8, 3.2 and 5.8. Fluid was obtained 1 h after a milk feeding, a time of maximum peptic activity, from 12 infants with a mean gestational age of 29.7 +/- 0.8 weeks at birth and a postnatal age of 24.7 +/- 3.2 days at sampling. Hydrolysis of all three proteins as indicated by generation of trichloroacetic acid soluble material from iodinated substrate was maximal at acid pH and declined by greater than 75% at pH 5.8, lactoferrin was less rapidly degraded than casein at low pH and transferrin breakdown was intermediate. Analysis of reaction mixtures by SDS-polyacrylamide gel electrophoresis showed degradation of lactoferrin and transferrin to low molecular weight products at pH 3.2 but minimal breakdown at pH 5.8. Several discrete fragments were generated at low pH, including species with molecular weights of 41,000-42,000 which may represent half-molecules. We conclude that dietary lactoferrin and transferrin may be degraded by preterm infant gastric fluid to discrete species, but that hydrolysis may be minimal at the prevailing postprandial pH. Consequently they may be rendered available for possible subsequent biological action within the infant.

Milk from several species contains a variety of biologically-important polypeptides which may function either within the developing gastrointestinal tract or at distant body sites following absorption from the gut. Because the capacity to perform such funtions may be dependent in part upon the nature of luminal digestion of the peptide, a method for estimating digestive susceptibility and for preparing generated degradation products for further study is desirable. A method is described in which a radiolabelled peptide is incubated in vitro with fluid flushed from the intestinal lumen of rats, followed by detection of degradation products soluble in acid. Using casein as substrate, rat small intestinal proteolysis was shown to be optimal at pH 7.4 in the presence of 5–10 mM CaCl 2 . In contrast to previous reports of gastrointestinal deiodination in vivo , no generation of inorganic iodine occurs during the in vitro reaction with luminal fluid. Using this assay, the substantially greater digestibility of bovine casein compared to lactoferrin was demonstrated. The method is simple, reproducible, inexpensive, and requires only small amounts of luminal fluid. Application to any dietary polypeptide and gastrointestinal fluid should be possible.

An increasing body of evidence suggests that human milk proteins may vary in their digestibility within the gastrointestinal tract. Secretory IgA, lactoferrin, and lysozyme have all been detected in substantial quantities in the stool of breast-fed infants and in vitro these proteins possess various degrees of stability at low pH and resistance to hydrolysis by pancreatic proteases. We have evaluated the ontogeny of differential milk protein digestibility in a heterologous system by incubating human milk with luminal fluid flushed from the small intestine of 12-day old suckling and 31-day old weanling rats, followed by analysis of protein profiles by electrophoresis in polyacrylamide gels containing SDS. Luminal fluid from the weanling degraded beta-casein most extensively, followed by lactalbumin, lysozyme, and lactoferrin, respectively. Little or no degradation of immunoglobulin could be detected. By contrast, luminal fluid from suckling rats degraded primarily beta-casein, which it hydrolyzed to a lesser extent than did weanling fluid. Other major milk-proteins were minimally digested. Incubation of luminal fluid with 125 I human casein followed by measurement of radioactivity in trichloroacetic acid-soluble material demonstrated that weanling hydrolytic capacity was approximately 25-fold greater than that of the suckling for this substrate. These preliminary findings in a heterologous system suggest that differential luminal digestibility of human milk proteins may occur in the small intestine and that the susceptibility of individual protein species to hydrolysis may vary during postnatal development.

Although stress during the perinatal period may influence a number of enzymes in the gastrointestinal tract, the resulting effects on digestive processes are not completely understood. In suckling rats, corticosteroid administration increases levels of proteases in gastric mucosa and pancreas, but previous studies of unstimulated luminal fluid proteolytic activity suggest no effect. To re-evaluate this phenomenon, we injected suckling rats with cortisone acetate (5 mg/l00 g body weight) subcutaneously daily on days 9-11 followed by sacrifice on day 12; littermates served as controls. Luminal fluid from stomach and small intestine was analyzed for proteolytic activity by a sensitive assay in which incubation in vitro with 125I-bovine casein was followed by measurement of radioactivity soluble in trichloroacetic acid. Cortisone acetate produced significant increases in luminal proteolytic activity in all gastrointestinal segments with the most dramatic effect observed in the ileum; this segment showed a more than 10-fold enhancement of proteolysis with steroid treatment. Analysis of acid-precipitable reaction products by electrophoresis in polyacrylamide gels containing sodium dodecyl sulfate also revealed enhancement of casein degradation by luminal fluid in all segments from steroid-treated animals. We conclude that corticosteroid increases luminal proteolysis in the gastrointestinal tract of the suckling rat. This phenomenon may have implications for steroid-induced premature closure to macromolecular absorption and protein digestive capacity during the perinatal period.

Because reports comparing the nitrogen content of breast milk from mothers delivering prematurely and at term have conflicted, the present study sought to compare these milks during the first month of lactation with respect to total protein and the distribution of protein among individual protein species and amino acids. No significant differences in total protein concentration were established. However, immunoglobulin comprised a greater proportion of protein in preterm milk than in term milk. The major component of the milk casein fraction, beta-casein, was present in similar proportions in early term and preterm milk, yet increased with time in term milk but not preterm milk. Lactoferrin and lactalbumin were similar in both milks. Differences in amino acid composition were found for serine, arginine, and tyrosine. With respect to protein composition, preterm milk and term milk thus differ during the first month of lactation, and the different patterns of change in individual components suggest that factors other than milk volume contribute to protein content.

Prostaglandins are present in breast milk and may protect and maintain intestinal epithelial cell integrity in developing mammals. In view of their very short half-life in other body tissues and fluids, studies were performed to determine prostaglandin stability in milk and gastric fluid. Tritiated prostaglandins E2 and F2α were incubated for 30 min in whole milk, milk cells, and milk plasma obtained from mothers delivering at term and prematurely, and in preterm infant gastric fluid. Radioactivity chromatographic analysis revealed minimal degradation of PG in milk preparations and gastric fluid. Thus, milk may serve as an effective natural medium for PG delivery to the gastrointestinal tract. The cytoprotective effect of prostaglandins on the gastrointestinal tract may be related to their stability and lack of degradation in milk and gastric digestive juices.

The abortive development of bacteriophage T7 in Escherichia coli cells carrying F′ factors has previously been attributed to lack of virus-directed modification of ribosomes in such cells. However, we find that 6–8 min after T7 infection of male bacteria there is an overall cessation of macromolecular synthesis, resulting in reduced production of DNA, late messenger RNA, and both early and late T7 proteins. Processing of an early viral protein has been detected in F − hosts; this processing is incomplete in F′ infection. The overall paralysis of macromolecular metabolism is correlated in time with a permeability change resulting in loss of the entire acid-soluble pool of phosphorus-containing compounds from the cells ( Britton and Haselkorn, 1975 ). Thus T7 development in F′ cells appears to be arrested at a particular time without regard to the developmental stage reached by T7 at that time.

The abortive development of bacteriophage T7 in E. coli cells carrying F factors has previously been attributed to a lack of virus-directed modification of ribosomes in such cells. We find it unnecessary to postulate such translational control to explain the failure of T7 development. Instead, there is a general cessation of macromolecular syntheses around 8 min after T7 infection of F' cells. This cessation is correlated with a sudden outflow of the entire acid-soluble pool of phosphorus-containing compounds and loss of the ability to accumulate amino acids. Manifestation of these defects requires expression of at least one T7 gene and one episomal gene.

Perinatal asphyxia may occur prior to or at the time of birth, leading to hypoxia and acidosis with persistence of the fetal circulatory pattern. Resuscitation facilitates transition to the adult circulatory pattern by restoring normal oxygenation, ventilation, and perfusion. Assessment of the degree of asphyxia should utilize the Apgar score, and resuscitation should proceed in a stepwise fashion to an extent determined by the degree of depression. Aspects of resuscitation unique to the newborn are reviewed, in addition to situations requiring specific intervention.

Epidermal growth factor (EGF), present in high concentrations in milk, may play a role in growth of the gastrointestinal tract. Resistance to proteolytic degradation in the stomach is necessary if ingested EGF is to function within the gastrointestinal tract. Although EGF stability to low pH and proteases predicts gastric survival, the extent of digestion in the stomach remains to be defined. Consequently, we measured gastric degradation of 125I-human recombinant EGF in preterm infants with an in vitro method in which EGF was incubated at 37 degrees C with stomach fluid at pH 1.8, 3.2, and 5.8 followed by analysis of degradation products. As maximal acid proteolytic activity is present one hour after feeding in preterm infants, fluid was obtained at that time from 18 infants with a mean gestational age at birth of 30.4 (3.0) (SD) weeks and a postnatal age of 26.3 (12.7) days at sampling. Incubations for up to 60 minutes revealed minimal loss of trichloroacetic acid precipitable radioactivity, in contrast to the substantial hydrolysis of iodinated casein which occurred under the same conditions. Chromatography of reaction mixtures on Sephadex G-25 showed a single major peak of radioactivity which coeluted with EGF. Epidermal growth factor also retained greater than 75% of its ability to bind to anti-EGF affinity columns and placental membrane receptors after incubation with gastric fluid. These data support the concept of substantial gastric survival of ingested EGF in a potentially biologically active form in preterm infants.

Campomelic dysplasia is a generalized disorder of cartilaginous growth and development, leading to early death from pulmonary insufficiency. We describe the airway dynamics as observed bronchoscopically in two affected infants. Both infants demonstrated anatomic compromise of the upper airway and diffuse laryngotracheobronchomalacia. Additionally, both had a characteristically small, bell-shaped thoracic cage. The abnormal airway dynamics produced serious inspiratory and expiratory obstruction in these infants and, in combination with the restrictive chest wall defect, led rapidly to the development of respiratory failure. While palliative procedures such as tracheostomy may temporarily improve airway dynamics, future respiratory tract insults may prove fatal. Pediatr Pulmonol 1987; 3:364–367.

Epidermal growth factor (EGF), present in high concentrations in the milk of various species, is biologically active following oral administration to young animals. Although in vivo studies show gastrointestinal processing of dietary EGF during early postnatal development, the relative importance of luminal and mucosal digestion in such processing is undefined. To characterize the luminal metabolism of dietary EGF in the developing gastrointestinal tract, we incubated human recombinant 125I-EGF in vitro at 37 degrees with luminal fluid from the stomach and various segments of the small intestine of 12 day old suckling and 31 day old weanling rats and analyzed the resulting reaction products. The rate of EGF hydrolysis as determined by generation of acid soluble material was greater in weanling small intestine than in suckling, with maximal hydrolytic capacity observed in the mid-jejunum and ileum. Minimal hydrolysis was observed with stomach fluid from both age groups, and EGF retained its ability to elute as a single species on Sephadex G-25 columns and to bind to monospecific affinity columns and placental membrane receptors. Incubation with suckling small intestinal fluid produced little change in the chromatographic profile on Sephadex G-25, but a reduction in antibody and receptor binding was observed. In contrast, incubation with weanling small intestinal fluid yielded both a more pronounced loss of EGF-like material on G-25 columns and a greater reduction in receptor and antibody binding. We conclude that little luminal EGF degradation occurs in the rat stomach during the suckling and weanling periods, but that in the lumen of the small intestine breakdown increases during postnatal development.

Epidermal growth factor (EGF), present in the milk of a number of species, may be trophic for the gastrointestinal tract in the perinatal period. Previous studies from our laboratory have demonstrated intact luminal survival of enterally-administered EGF in suckling rats with subsequent absorption from the gut. Since the capacity for survival and absorption may be influenced by digestive processes within the gastrointestinal lumen, we evaluated the development of EGF degradative activity by measuring the release of trichloroacetic acid soluble radioactivity from human 124I-EGF incubated in vitro with fluid flushed from the lumen of the stomach and small intestine of 12-day old suckling and 31-day old weanling rats. In the stomach at pH 3.2, minimal luminal degradation of EGF was demonstrable in both suckling and weanling rats. By contrast, fluid from all small intestinal segments at both ages showed EGF degradative capacity at neutral pH, although hydrolytic activity of the weanling was twice that of the suckling. We conclude that EGF may be degraded in the lumen of the small intestine of the rat and that luminal digestive capacity toward this growth factor increases after weaning.