Wound Healing and Scar Patterning After Addition of Autologous Skin Cell Suspension to Meshed Grafts.

INTRODUCTION: A common treatment for large deep-to-full-thickness burns is excision and grafting with a widely meshed split-thickness skin graft (mSTSG). Due to the differential healing of the interstices and adhered split-thickness skin graft, wound patterning and delayed wound healing are common outcomes of this treatment. Delayed healing may increase infection rates and wound care requirements, while wound patterning may be psychologically and aesthetically consequential for patients. Autologous skin cell suspension (ASCS) can be used to "over spray" a meshed autograft. It was hypothesized that the use of ASCS combined with mSTSG would increase the rate of wound healing and decrease patterning in healed burn wounds. METHODS: Full-thickness burns or excisional wounds (n = 8 each) were created in red Duroc pigs and received 4:1 mSTSGs after wound bed preparation. Half of the wounds received ASCS and half did not at the time of grafting. Percent re-epithelialization, patterning, rete ridge ratio, cellularity, dermal and epidermal thickness, immunofluorescent S100ß staining, and melanin index were assessed for each scar. RESULTS: Wounds that received ASCS exhibited increased rates of re-epithelialization (burn +ACSC versus burn-ASCS; day 3 (53.9 ± 3.1 versus 34.3 ± 3.3, P = 0.009): day 5 (68.1 ± 1.6 versus 40.8 ± 3.2, P < 0.001)). Excision +ASCS versus excision-ASCS; day 7 (98.1 ± 1.2 versus 86.4 ± 2.0, day 7 P = 0.022) compared to wounds not treated with ASCS. There was no difference in rete ridge ratio, cellularity, dermal thickness, epidermal thickness, S100ß staining, melanin index, or patterning was measured between wounds that received ASCS and those that did not. CONCLUSIONS: The addition of ASCS to 4:1 mSTSGs leads to increased rate of wound healing but does not impact the degree of patterning in this model, suggesting that ASCS application likely robustly transfers keratinocytes but not functioning melanocytes at acute timepoints.

Laser-assisted drug delivery of synthetic alpha melanocyte stimulating hormone and L-tyrosine leads to increased pigmentation area and expression of melanogenesis genes in a porcine hypertrophic scar model.

OBJECTIVES: One symptom of hypertrophic scar (HTS) that can develop after burn injury is dyschromia with hyper- and hypopigmentation. There are limited treatments for these conditions. Previously, we showed there is no expression of alpha melanocyte stimulating hormone (α-MSH) in hypopigmented scars, and if these melanocytes are treated with synthetic α-MSH in vitro, they respond by repigmenting. The current study tested the same hypothesis in the in vivo environment using laser-assisted drug delivery (LADD). METHODS: HTSs were created in red Duroc pigs. At Day 77 (pre), they were treated with CO2 fractional ablative laser (FLSR). Synthetic α-MSH was delivered as a topical solution dissolved in  l-tyrosine (n = 6, treated). Control scars received LADD of  l-tyrosine only (n = 2, control). Scars were treated and examined weekly through Week 4. Digital images and punch biopsies of hyper, hypo-, and normally pigmented scar and skin were collected. Digital pictures were analyzed with ImageJ by tracing the area of hyperpigmentation. Epidermal sheets were obtained from punch biopsies through dispase separation and RNA was isolated. qRT-PCR was run for melanogenesis-related genes: tyrosinase (TYR), tyrosinase-related protein-1 (TYRP1), and dopachrome tautomerase (DCT). Two-way ANOVA with multiple comparisons and Dunnett's correction compared the groups. RESULTS: The areas of hyperpigmentation were variable before treatment. Therefore, data is represented as fold-change where each scar was normalized to its own pre value. Within the LADD of NDP α-MSH + l-tyrosine group, hyperpigmented areas gradually increased each week, reaching 1.3-fold over pre by Week 4. At each timepoint, area of hyperpigmentation was greater in the treated versus the control (1.04 ± 0.05 vs. 0.89 ± 0.08, 1.21 ± 0.07 vs. 0.98 ± 0.24, 1.21 ± 0.08 vs. 1.04 ± 0.11, 1.28 ± 0.11 vs. 0.94 ± 0.25; fold-change from pre-). Within the treatment group, pretreatment, levels of TYR were decreased -17.76 ± 4.52 below the level of normal skin in hypopigmented scars. After 1 treatment, potentially due to laser fractionation, the levels decreased to -43.49 ± 5.52. After 2, 3, and 4 treatments, there was ever increasing levels of TYR to almost the level of normally pigmented skin (-35.74 ± 15.72, -23.25 ± 6.80, -5.52 ± 2.22 [p < 0.01, Week 4]). This pattern was also observed for TYRP1 (pre = -12.94 ± 1.82, Week 1 = -48.85 ± 13.25 [p < 0.01], Weeks 2, 3, and 4 = -34.45 ± 14.64, -28.19 ± 4.98, -6.93 ± 3.05 [p < 0.01, Week 4]) and DCT (pre = -214.95 ± 89.42, Week 1 = -487.93 ± 126.32 [p < 0.05], Weeks 2, 3, and 4 = -219.06 ± 79.33, -72.91 ± 20.45 [p < 0.001], -76.00 ± 24.26 [p < 0.001]). Similar patterns were observed for scars treated with LADD of  l-tyrosine alone without NDP α-MSH. For each gene, in hyperpigmented scar, levels increased at Week 4 of treatment compared to Week 1 (p < 0.01). CONCLUSIONS: A clinically-relevant FLSR treatment method can be combined with topical delivery of synthetic α-MSH and l-tyrosine to increase the area of pigmentation and expression of melanogenesis genes in hypopigmented HTS. LADD of  l-tyrosine alone leads to increased expression of melanogenesis genes. Future studies will aim to optimize drug delivery, timing, and dosing.

Acute kidney injury is associated with bronchopulmonary dysplasia/mortality in premature infants.

BACKGROUND: Acute kidney injury (AKI) impairs electrolyte balance, alters fluid homeostasis and decreases toxin excretion. More recent data suggest it also affects the physiology of distant organs. METHODS: We performed a prospective cohort study which invloved 122 premature infants [birth weight (BW) ≤1200 g and/or gestational age (GA) <31 weeks] to determine relationships between AKI and bronchopulmonary dysplasia (BPD)/mortality. Days until oxygen discontinuation was compared between those with and without AKI in survivors who received oxygen for ≥24 h. RESULTS: Acute kidney disease, defined by a rise in serum creatinine (SCr) of ≥0.3 mg/dl or an increase in SCr of ≥150%, occurred in 36/122 (30%) of the premature infants. Those with AKI had a 70% higher risk of oxygen requirement or of dying at 28 days of life [relative risk (RR) 1.71, 95% confidence interval (CI) 1.22-2.39; p < 0.002]. This association remained after controlling for GA, pre-eclampsia, 5 min Apgar score and percentage maximum weight change (max % weight Δ) in the first 4 days (RR 1.45, 95% CI 1.07-1.97); p < 0.02). Similar findings were noted for receipt of mechanical ventilation/death by day 28 (adjusted RR 1.53, 95% CI 1.05-2.22; p < 0.03). Those without AKI were 2.5-fold more likely to come off oxygen [hazard ratio (HR) 1.3-5; p < 0.02) than those with AKI, even when controlling for GA, pre-eclampsia, 5 min Apgar and max % weight Δ (multivariate HR 2.0, 95% CI 0.9-4.0; p < 0.06). CONCLUSIONS: In premature infants, AKI is associated with BPD/mortality. As AKI could lead to altered lung physiology, interventions to ameliorate AKI could improve long-term BPD.

Early-Onset Neonatal Sepsis 2015 to 2017, the Rise of Escherichia coli, and the Need for Novel Prevention Strategies.

Importance: Early-onset sepsis (EOS) remains a potentially fatal newborn condition. Ongoing surveillance is critical to optimize prevention and treatment strategies. Objective: To describe the current incidence, microbiology, morbidity, and mortality of EOS among a cohort of term and preterm infants. Design, Setting, and Participants: This prospective surveillance study included a cohort of infants born at a gestational age (GA) of at least 22 weeks and birth weight of greater than 400 g from 18 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network from April 1, 2015, to March 31, 2017. Data were analyzed from June 14, 2019, to January 28, 2020. Main Outcomes and Measures: Early-onset sepsis defined by isolation of pathogenic species from blood or cerebrospinal fluid culture within 72 hours of birth and antibiotic treatment for at least 5 days or until death. Results: A total of 235 EOS cases (127 male [54.0%]) were identified among 217 480 newborns (1.08 [95% CI, 0.95-1.23] cases per 1000 live births). Incidence varied significantly by GA and was highest among infants with a GA of 22 to 28 weeks (18.47 [95% CI, 14.57-23.38] cases per 1000). No significant differences in EOS incidence were observed by sex, race, or ethnicity. The most frequent pathogens were Escherichia coli (86 [36.6%]) and group B streptococcus (GBS; 71 [30.2%]). E coli disease primarily occurred among preterm infants (68 of 131 [51.9%]); GBS disease primarily occurred among term infants (54 of 104 [51.9%]), with 24 of 45 GBS cases (53.3%) seen in infants born to mothers with negative GBS screening test results. Intrapartum antibiotics were administered to 162 mothers (68.9%; 110 of 131 [84.0%] preterm and 52 of 104 [50.0%] term), most commonly for suspected chorioamnionitis. Neonatal empirical antibiotic treatment most frequently included ampicillin and gentamicin. All GBS isolates were tested, but only 18 of 81 (22.2%) E coli isolates tested were susceptible to ampicillin; 6 of 77 E coli isolates (7.8%) were resistant to both ampicillin and gentamicin. Nearly all newborns with EOS (220 of 235 [93.6%]) displayed signs of illness within 72 hours of birth. Death occurred in 38 of 131 infected infants with GA of less than 37 weeks (29.0%); no term infants died. Compared with earlier surveillance (2006-2009), the rate of E coli infection increased among very low-birth-weight (401-1500 g) infants (8.68 [95% CI, 6.50-11.60] vs 5.07 [95% CI, 3.93-6.53] per 1000 live births; P = .008). Conclusions and Relevance: In this study, EOS incidence and associated mortality disproportionately occurred in preterm infants. Contemporary cases have demonstrated the limitations of current GBS prevention strategies. The increase in E coli infections among very low-birth-weight infants warrants continued study. Ampicillin and gentamicin remained effective antibiotics in most cases, but ongoing surveillance should monitor antibiotic susceptibilities of EOS pathogens.

Racial/Ethnic Disparities Among Extremely Preterm Infants in the United States From 2002 to 2016.

Importance: Racial/ethnic disparities in quality of care among extremely preterm infants are associated with adverse outcomes. Objective: To assess whether racial/ethnic disparities in major outcomes and key care practices were changing over time among extremely preterm infants. Design, Setting, and Participants: This observational cohort study used prospectively collected data from 25 US academic medical centers. Participants included 20 092 infants of 22 to 27 weeks' gestation with a birth weight of 401 to 1500 g born at centers participating in the National Institute of Child Health and Human Development Neonatal Research Network from 2002 to 2016. Of these infants, 9316 born from 2006 to 2014 were eligible for follow-up at 18 to 26 months' postmenstrual age (excluding 5871 infants born before 2006, 2594 infants born after 2014, and 2311 ineligible infants including 64 with birth weight >1000 g and 2247 infants with gestational age >26 6/7 weeks), of whom 745 (8.0%) did not have known follow-up outcomes at 18 to 26 months. Main Outcomes and Measures: Rates of mortality, major morbidities, and care practice use over time were evaluated using models adjusted for baseline characteristics, center, and birth year. Data analyses were conducted from 2018 to 2019. Results: In total, 20 092 infants with a mean (SD) gestational age of 25.1 (1.5) weeks met the inclusion criteria and were available for the primary outcome: 8331 (41.5%) black infants, 3701 (18.4%) Hispanic infants, and 8060 (40.1%) white infants. Hospital mortality decreased over time in all groups. The rate of improvement in hospital mortality over time did not differ among black and Hispanic infants compared with white infants (black infants went from 35% to 24%, Hispanic infants went from 32% to 27%, and white infants went from 30% to 22%; P = .59 for race × year interaction). The rates of late-onset sepsis among black infants (went from 37% to 24%) and Hispanic infants (went from 45% to 23%) were initially higher than for white infants (went from 36% to 25%) but decreased more rapidly and converged during the most recent years (P = .02 for race × year interaction). Changes in rates of other major morbidities did not differ by race/ethnicity. Death before follow-up decreased over time (from 2006 to 2014: black infants, 14%; Hispanic infants, 39%, white infants, 15%), but moderate-severe neurodevelopmental impairment increased over time in all racial/ethnic groups (increase from 2006 to 2014: black infants, 70%; Hispanic infants, 123%; white infants, 130%). Rates of antenatal corticosteroid exposure (black infants went from 72% to 90%, Hispanic infants went from 73% to 83%, and white infants went from 86% to 90%; P = .01 for race × year interaction) and of cesarean delivery (black infants went from 45% to 59%, Hispanic infants went from 49% to 59%, and white infants went from 62% to 63%; P = .03 for race × year interaction) were initially lower among black and Hispanic infants compared with white infants, but these differences decreased over time. Conclusions and Relevance: Among extremely preterm infants, improvements in adjusted rates of mortality and most major morbidities did not differ by race/ethnicity, but rates of neurodevelopmental impairment increased in all groups. There were narrowing racial/ethnic disparities in important care practices, including the use of antenatal corticosteroids and cesarean delivery.

The role of patent ductus arteriosus ligation in bronchopulmonary dysplasia: reexamining a randomized controlled trial.

OBJECTIVE: To reexamine data from a randomized controlled trial of prophylactic ductus ligation to determine whether ligation contributes directly to the development of bronchopulmonary dysplasia (BPD) in extremely low birth weight infants. STUDY DESIGN: The control group underwent ligation only if they had development of a symptomatic patent ductus arteriosus (PDA). The Prophylactic Ligation group underwent ligation within 24 hours of birth regardless of the presence or absence of symptoms of a PDA. We hypothesized that the incidence of BPD would be higher in the prophylactic ligation group because more ligations were performed than in the control group. RESULTS: Prophylactic ligation significantly increased the incidence of BPD (defined as a supplemental oxygen requirement at 36 weeks postmenstrual age) and the incidence of mechanical ventilation at 36 weeks. The groups were statistically similar in gestation, sex, race, fluid administration, intraventricular hemorrhage, pulmonary air leaks, and survival to 36 weeks. The lower incidence of BPD in the control group occurred despite the fact that the incidence of necrotizing enterocolitis (a known risk factor for BPD) was significantly elevated in the control group. Only infants who had previously undergone a PDA ligation had development of BPD in the control group. CONCLUSION: Prophylactic ligation, while eliminating the PDA, increases the risk for BPD.

Educational impact of the neonatal resuscitation program in low-risk delivery centers in a developing country.

OBJECTIVE: To evaluate the effectiveness of the American Academy of Pediatrics Neonatal Resuscitation Program (NRP) in improving knowledge, skills, and self-efficacy of nurse midwives in low-risk delivery clinics in a developing country. STUDY DESIGN: We used the content specifications of the NRP material applicable to college-educated nurse midwives working in low-risk clinics in Zambia to develop performance and self-efficacy evaluations focused on principles of resuscitation, initial steps, ventilation, and chest compressions. These evaluations were administered to 127 nurse midwives before and after NRP training and 6-months later. RESULTS: After training, written scores (knowledge evaluation) improved from 57%+/-14% to 80%+/-12% (mean+/-SD; P< .0001); performance scores (skills evaluation) improved the most from 43%+/-21% to 88%+/-9% (P< .0001); self-efficacy scores improved from 74%+/-14% to 90%+/-10% (P< .0001). Written and performance scores decreased significantly 6 months after training, but self-efficacy scores remained high. CONCLUSIONS: As conducted, the NRP training improved educational outcomes in college-educated practicing nurse midwives. Pre-training knowledge and skills scores were relatively low despite the advanced formal education and experience of the participants, whereas the self-efficacy scores were high. NRP training has the potential to substantially improve knowledge and skills of neonatal resuscitation.

Mortality and morbidity of VLBW infants with trisomy 13 or trisomy 18.

OBJECTIVE: Little is known about how very low birth weight (VLBW) affects survival and morbidities among infants with trisomy 13 (T13) or trisomy 18 (T18). We examined the care plans for VLBW infants with T13 or T18 and compared their risks of mortality and neonatal morbidities with VLBW infants with trisomy 21 and VLBW infants without birth defects. METHODS: Infants with birth weight 401 to 1500 g born or cared for at a participating center of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network during the period 1994-2009 were studied. Poisson regression models were used to examine risk of death and neonatal morbidities among infants with T13 or T18. RESULTS: Of 52,262 VLBW infants, 38 (0.07%) had T13 and 128 (0.24%) had T18. Intensity of care in the delivery room varied depending on whether the trisomy was diagnosed before or after birth. The plan for subsequent care for the majority of the infants was to withdraw care or to provide comfort care. Eleven percent of infants with T13 and 9% of infants with T18 survived to hospital discharge. Survivors with T13 or T18 had significantly increased risk of patent ductus arteriosus and respiratory distress syndrome compared with infants without birth defects. No infant with T13 or T18 developed necrotizing enterocolitis. CONCLUSIONS: In this cohort of liveborn VLBW infants with T13 or T18, the timing of trisomy diagnosis affected the plan for care, survival was poor, and death usually occurred early.

Impact of a physiologic definition on bronchopulmonary dysplasia rates.

OBJECTIVE: Bronchopulmonary dysplasia (BPD) is the endpoint of many intervention trials in neonatology, yet the outcome measure when based solely on oxygen administration may be confounded by differing criteria for oxygen administration between physicians. We previously reported a technique to standardize the definition of BPD between sites by using a timed room-air challenge in selected infants. We hypothesized that a physiologic definition of BPD would reduce the variation in observed rates of BPD among different neonatal centers. Methodology. A total of 1598 consecutive inborn premature infants (501-1249 g birth weight) who remained hospitalized at 36 weeks' postmenstrual age were prospectively assessed and assigned an outcome with both a clinical definition and physiologic definition of BPD. The clinical definition of BPD was oxygen supplementation at exactly 36 weeks' postmenstrual age. The physiologic definition of BPD was assigned at 36 +/- 1 weeks' postmenstrual age and included 2 distinct subpopulations. First, neonates on positive pressure support or receiving >30% supplemental oxygen with saturations between 90% and 96% were assigned the outcome BPD and not tested further. Second, those receiving < or =30% oxygen or effective oxygen >30% with saturations >96% underwent a room-air challenge with continuous observation and oxygen-saturation monitoring. Outcomes of the room-air challenge were "no BPD" (saturations > or =90% during weaning and in room air for 30 minutes) or "BPD" (saturation <90%). At the conclusion of the room-air challenge, all infants were returned to their baseline oxygen levels. Safety (apnea, bradycardia, increased oxygen use) and outcomes of the physiologic definition versus the clinical definition were assessed. RESULTS: A total of 560 (35.0%) neonates were diagnosed with BPD by the clinical definition of oxygen use at 36 weeks' postmenstrual age. The physiologic definition diagnosed BPD in 398 (25.0%) neonates in the cohort. All infants were safely studied. There were marked differences in the impact of the definition on BPD rates between centers (mean reduction: 10%; range: 0-44%). Sixteen centers had a decrease in their BPD rate, and 1 center had no change in their rate. CONCLUSIONS: The physiologic definition of BPD reduced the overall rate of BPD and reduced the variation among centers. Significant center differences in the impact of the physiologic definition were seen, and differences remained even with the use of this standardized definition. The magnitude of the change in BPD rate is comparable to the magnitude of treatment effects seen in some clinical trials in BPD. The physiologic definition of BPD facilitates the measurement of BPD as an outcome in clinical trials and the comparison between and within centers over time.