RSV-related hospitalization and outpatient palivizumab use in very preterm (born at <29 wGA) infants: 2003-2020

Respiratory syncytial virus (RSV) is a leading cause of bronchiolitis and pneumonia in children under one year and a leading cause of infant hospitalization. Palivizumab was approved by the FDA in 1998 as RSV immunoprophylaxis to prevent severe RSV disease in children with specific health conditions and those born at <35 weeks gestational age (wGA). This study compared RSV-related hospitalization (RSVH) and RSVH characteristics in very preterm (<29 wGA) and term (>37 wGA) infants. Using the MarketScan Commercial and Multi-State Medicaid administrative claims databases, infants born between 7/1/2003 and 6/30/2020 were identified and classified as very preterm or term. Infants with evidence of health conditions, such as congenital heart disease and cystic fibrosis, were excluded. During 2003-2020 RSV seasons (November to March), claims incurred by infants while they were <12 months old were evaluated for outpatient administration of palivizumab and RSVH. The study included 40,123 very preterm infants and 4,421,942 term infants. Rate of RSVH in very preterm infants ranged 1.5-3.8 per 100 infant-seasons in commercially insured infants and 3.5-8.4 in Medicaid insured infants and were inversely related to wGA at birth. Relative risk of RSVH in very preterm was 3-4 times higher, and ICU admissions and mechanical ventilation were more common during RSVH in very preterm infants relative to term infants. However, these outcomes were less common or less severe in very preterm infants who received outpatient palivizumab administration, despite evidence of higher baseline risk of RSVH in these infants.

NICU discharge preparation and transition planning: introduction

The National Perinatal Association (NPA) coordinated a multidisciplinary work group to develop guidelines and recommendations for Neonatal Intensive Care Unit (NICU) discharge preparation and thus the transition from NICU to home for infants admitted to the NICU and their families. In this section, we explore the concepts of NICU discharge readiness as well as transition planning and preparation. We describe the process that was used to develop the guidelines and recommendations as well as the timeline for the work. NPA hopes that the readers will find the Interdisciplinary Guidelines and Recommendations for NICU Discharge Preparation and Transition Planning to be beneficial, useful, and pertinent.

Discharge planning considerations for the neonatal intensive care unit

Neonatal intensive care unit (NICU) discharge readiness is the primary caregivers' masterful attainment of technical care skills and knowledge, emotional comfort and confidence with infant care by the time of discharge. NICU discharge preparation is the process of facilitating discharge readiness. Discharge preparation is the process with discharge readiness as the goal. Our previous work described the importance of NICU discharge readiness and strategies for discharge preparation from an American medical system perspective. NICU discharge planning is, however, of international relevance as challenges in relation to hospital discharge are a recurring global theme. In this manuscript, we conceptualise NICU discharge preparation with international perspective.

Psychosocial Stress and Adversity: Effects from the Perinatal Period to Adulthood

Early exposure to stress and adversity can have both immediate and lasting effects on physical and psychological health. Critical periods have been identified in infancy, during which the presence or absence of experiences can alter developmental trajectories. There are multiple explanations for how exposure to psychosocial stress, before conception or early in life, has an impact on later increased risk for developmental delays, mental health, and chronic metabolic diseases. Through both epidemiologic and animal models, the mechanisms by which experiences are transmitted across generations are being identified. Because psychosocial stress has multiple components that can act as stress mediators, a comprehensive understanding of the complex interactions between multiple adverse or beneficial experiences and their ultimate effects on health is essential to best identify interventions that will improve health and outcomes. This review outlines what is known about the biology, transfer, and effects of psychosocial stress and early life adversity from the perinatal period to adulthood. This information can be used to identify potential areas in which clinicians in neonatal medicine could intervene to improve outcomes.

Preparing for Discharge From the Neonatal Intensive Care Unit

BACKGROUND

Discharge readiness is a key determinant of outcomes for families in the NICU. Since 2003, using a broad set of outcome and process measures, we have conducted an ongoing quality improvement initiative to improve the discharge preparation process in our NICU and readiness of families being discharged from the NICU.

METHODS

Iterative improvements to the discharge preparation process were made by a multidisciplinary committee. Discharge readiness was measured by using a parental and nurse survey for all families discharged from our NICU. Primary outcome measures included parental self-assessment of discharge readiness and nurse assessment of the family's emotional and technical discharge readiness. Secondary outcome measures included assessment of specific technical skills and emotional factors. Process measures included nursing familiarity with family at discharge. Improvement over time was analyzed by using statistical process control charts.

RESULTS

Significant improvement was seen in all primary outcome measures. Family self-assessment of discharge readiness increased from 85.1% to 89.1%; nurse assessment of the family's emotional discharge readiness increased from 81.2% to 90.5%, and technical discharge readiness increased from 81.4% to 87.7%. Several secondary outcome measures revealed significant improvement, whereas most remained stable. Nurse familiarity with the family at discharge increased over time.

CONCLUSIONS

Quality improvement methodology can be used to measure and improve discharge readiness of families with an infant in the NICU. This model can provide the necessary framework for a structured approach to systematically evaluating and improving the discharge preparation process in a NICU.

Epidemiology of perinatal substance use: Exploring trends in maternal substance use

Over the last two decades, the prevalence of substance use among women of childbearing age has risen dramatically in the United States making substance use during pregnancy a significant public health concern. This article offers a general overview of the epidemiology of perinatal substance use focusing primarily on the United States but when available international trends will be presented as well.

Biocompatible Soft Fluidic Strain and Force Sensors for Wearable Devices

Fluidic soft sensors have been widely used in wearable devices for human motion capturing. However, thus far, the biocompatibility of the conductive liquid, the linearity of the sensing signal, and the hysteresis between the loading and release processes have limited the sensing quality as well as the applications of these sensors. In this paper, silicone based strain and force sensors composed of a novel biocompatible conductive liquid (potassium iodide and glycerol solution) are introduced. The strain sensors exhibit negligible hysteresis up to 5 Hz, with a gauge factor of 2.2 at 1 Hz. The force sensors feature a novel multi-functional layered structure, with micro-cylinder-filled channels to achieve high linearity, low hysteresis (5.3% hysteresis at 1 Hz), and good sensitivity (100% resistance increase at a 5 N load). The sensors' gauge factors are stable at various temperatures and humidity levels. These bio-compatible, low hysteresis, and high linearity sensors are promising for safe and reliable diagnostic devices, wearable motion capture, and compliant human-computer interfaces.

The Role of Integrated Care in a Medical Home for Patients With a Fetal Alcohol Spectrum Disorder

Fetal alcohol spectrum disorder (FASD) is an umbrella term used to describe preventable birth defects and intellectual and/or developmental disabilities resulting from prenatal alcohol exposure. The American Academy of Pediatrics has a previous clinical report in which diagnostic criteria for a child with an FASD are discussed and tools to assist pediatricians with its management can be found. This clinical report is intended to foster pediatrician awareness of approaches for screening for prenatal alcohol exposure in clinical practice, to guide management of a child with an FASD after the diagnosis is made, and to summarize available resources for FASD management.

Fetal Alcohol Research Caring for Patients with Prenatal Alcohol Exposure: A Needs Assessment

BACKGROUND

Prenatal alcohol exposure (PAE) is the United States' most common preventable cause of birth defects and intellectual and developmental disabilities collectively referred to as Fetal Alcohol Spectrum Disorders (FASD).

OBJECTIVES

This study was designed to identify gaps in pediatric providers' knowledge and practices regarding FASD patient identification, diagnosis, management and referral, and to inform needs-based FASD resource development.

METHODS

Pediatric providers (pediatricians, trainees, nurse practitioners) were exposed to survey links embedded in newsletters electronically distributed to the membership of two national professional societies. Survey responses were compiled and analyzed using descriptive statistics.

RESULTS

Of the 436 respondents, 71% were pediatricians and 88.2% suspected that a child in their practice could have an FASD. Only 29.2% of respondents felt "very comfortable" diagnosing or referring an individual with suspected FASD. Merely 11.5% were satisfied with their current FASD knowledge base and practice behaviour. Most respondents (89.6%) indicated online continuing education courses as preferred learning method and suggested their knowledge and practices would be best enhanced through FASD-specific diagnostic and referral checklists or algorithms, and patient education brochures and fact sheets.

CONCLUSIONS

This study showed that few respondents were satisfied with their current FASD knowledge or practice behaviours. Continuing FASD education, particularly through online courses, was strongly desired. To maximize FASD recognition and optimize care for patients with FASDs, pediatric care providers must ensure that their FASD knowledge base, practice skills and provision of medical home care remain current.

Supine sleep positioning in preterm and term infants after hospital discharge from 2000 to 2011

OBJECTIVE

Supine sleep positioning (SSP) has been shown to reduce the risk of sudden infant death syndrome (SIDS) and preterm infants are at higher risk for SIDS. Population-based estimates of SSP are lacking for the preterm population. The objectives of this study are: (1) compare the prevalence of SSP after hospital discharge for preterm and term infants in the United States; and (2) assess racial/ethnic disparities in SSP for preterm and term infants.

STUDY DESIGN

We analyzed the 2000 to 2011 data from the Pregnancy Risk Assessment Monitoring System of Centers for Disease Control and Prevention from 35 states. We measured prevalence of SSP by preterm and term gestational age (GA) categories. We calculated adjusted prevalence ratios (APR) to evaluate the likelihood of SSP for each GA category compared with term infants and the likelihood of SSP for non-Hispanic black (NHB) and Hispanic infants compared with non-Hispanic white (NHW) infants.

RESULTS

Prevalence of SSP varied by GA: ⩽27, 59.7%; 28 0/7 to 33 6/7, 63.7%; 34 0/7 to 36 6/7 (late preterm), 63.6%; and 37 0/7 to 42 6/7 (term) weeks, 66.8% (P<0.001). In the adjusted analyses, late preterm infants were slightly less likely to be placed in SSP compared with term infants (APR: 0.96, confidence interval: 0.95 to 0.98). There were racial/ethnic disparities in SSP for all GA categories when NHB and Hispanic infants were compared with NHW infants.

CONCLUSIONS

All infants had suboptimal adherence to SSP indicating a continued need to better engage families about SSP. Parents of late preterm infants and families of NHB and Hispanic infants will also require greater attention given their decreased likelihood of SSP.

Families Affected by Parental Substance Use

Children whose parents or caregivers use drugs or alcohol are at increased risk of short- and long-term sequelae ranging from medical problems to psychosocial and behavioral challenges. In the course of providing health care services to children, pediatricians are likely to encounter families affected by parental substance use and are in a unique position to intervene. Therefore, pediatricians need to know how to assess a child's risk in the context of a parent's substance use. The purposes of this clinical report are to review some of the short-term effects of maternal substance use during pregnancy and long-term implications of fetal exposure; describe typical medical, psychiatric, and behavioral symptoms of children and adolescents in families affected by substance use; and suggest proficiencies for pediatricians involved in the care of children and adolescents of families affected by substance use, including screening families, mandated reporting requirements, and directing families to community, regional, and state resources that can address needs and problems.

Treatment options for apnoea of prematurity

Apnoea of prematurity (AOP) affects almost all infants born at <28 weeks gestation or with birth weight <1000 g. When untreated, AOP may be associated with negative outcomes. Because of these negative outcomes, effective treatment for AOP is an important part of optimising care of preterm infants. Standard treatment usually involves xanthine therapy and respiratory support. Cutting-edge work with stochastic vibrotactile stimulation and new pharmaceutical agents continues to expand therapeutic options. In this article, we review the pathophysiology of AOP, associated conditions and treatment options.

Stochastic Resonance Effects on Apnea, Bradycardia, and Oxygenation: A Randomized Controlled Trial

OBJECTIVE

To evaluate the effect of stochastic resonance (SR) stimulation on preterm infant oxygen desaturation, bradycardia, and apnea events. We hypothesized that SR stimulation will reduce these events.

METHODS

This was a randomized crossover study conducted from April 2012 to July 2014. Eligible preterm infants were not receiving ventilation support and had at least 1 clinically documented apnea, bradycardia, and/or oxygen desaturation event. The 3 outcome variables were as follows: oxygen desaturation, bradycardia, and apnea events. Infants received up to two 3- or 4-hour intervention periods of 30-minute alternating intervals of SR stimulation and no SR stimulation. The first intervention period was randomly assigned to begin with SR stimulation either on or off, whereas the next intervention period automatically began with the opposite on/off state. We compared the SR stimulation "on" periods with the SR stimulation "off" periods with each infant serving as his or her own control.

RESULTS

The sample consisted of 36 infants with a mean (±SD) gestational age of 30.5 ± 3 weeks and a birth weight of 1409 ± 450 g. SR stimulation decreased the number of apneic events by 50%. SR stimulation ameliorated every aspect of clinically significant oxygen desaturation events, with a 20% to 35% decrease in the number, duration, and intensity of oxygen desaturation events when SR stimulation was on. Also, SR stimulation produced a nearly 20% reduction in the intensity of bradycardia events.

CONCLUSIONS

SR stimulation may be a noninvasive and nonpharmacologic treatment option for apnea, oxygen desaturation, and some aspects of bradycardia in premature infants.

Fetal Alcohol Spectrum Disorders

Prenatal exposure to alcohol can damage the developing fetus and is the leading preventable cause of birth defects and intellectual and neurodevelopmental disabilities. In 1973, fetal alcohol syndrome was first described as a specific cluster of birth defects resulting from alcohol exposure in utero. Subsequently, research unequivocally revealed that prenatal alcohol exposure causes a broad range of adverse developmental effects. Fetal alcohol spectrum disorder (FASD) is the general term that encompasses the range of adverse effects associated with prenatal alcohol exposure. The diagnostic criteria for fetal alcohol syndrome are specific, and comprehensive efforts are ongoing to establish definitive criteria for diagnosing the other FASDs. A large and growing body of research has led to evidence-based FASD education of professionals and the public, broader prevention initiatives, and recommended treatment approaches based on the following premises:▪ Alcohol-related birth defects and developmental disabilities are completely preventable when pregnant women abstain from alcohol use.▪ Neurocognitive and behavioral problems resulting from prenatal alcohol exposure are lifelong.▪ Early recognition, diagnosis, and therapy for any condition along the FASD continuum can result in improved outcomes.▪ During pregnancy:◦no amount of alcohol intake should be considered safe;◦there is no safe trimester to drink alcohol;◦all forms of alcohol, such as beer, wine, and liquor, pose similar risk; and◦binge drinking poses dose-related risk to the developing fetus.

Binge Drinking

Alcohol is the substance most frequently abused by children and adolescents in the United States, and its use is associated with the leading causes of death and serious injury at this age (ie, motor vehicle accidents, homicides, and suicides). Among youth who drink, the proportion who drink heavily is higher than among adult drinkers, increasing from approximately 50% in those 12 to 14 years of age to 72% among those 18 to 20 years of age. In this clinical report, the definition, epidemiology, and risk factors for binge drinking; the neurobiology of intoxication, blackouts, and hangovers; genetic considerations;and adverse outcomes are discussed. The report offers guidance for the pediatrician. As with any high-risk behavior, prevention plays a more important role than later intervention and has been shown to be more effective. In the pediatric office setting, it is important to ask every adolescent about alcohol use.

Late Preterm Infants and Neurodevelopmental Outcomes at Kindergarten

BACKGROUND AND OBJECTIVE

Late preterm infants (LPIs) (gestation 34 weeks and 0 days to 36 weeks and 6 days) compared with full-term infants (FTIs) are at increased risk for mortality and short- and long-term morbidity. The objective of this study was to assess the neurodevelopmental outcomes in a longitudinal cohort study of LPIs from infancy to school age and determine predictive values of earlier developmental testing compared with school-age testing.

METHODS

We used general estimating equations to calculate the odds of school readiness in a nationally representative cohort of 4900 full-term and 950 late preterm infants. We generated positive and negative predictive values of the ability of the 24-month Mental Developmental Index (MDI) scores of the Bayley Short Form, Research Edition, to predict Total School Readiness Score (TSRS) at kindergarten age.

RESULTS

In multivariable analysis, late preterm infants had higher odds of worse TSRSs (adjusted odds ratio 1.52 [95% confidence interval 1.06-2.18], P = .0215). The positive predictive value of a child having an MDI of <70 at 24 months and a TSRS <5% at kindergarten was 10.4%. The negative predictive value of having an MDI of >70 at 24 months and a TSRS >5% was 96.8%. Most infants improved score ranking over the study interval.

CONCLUSIONS

LPIs continue to be delayed at kindergarten compared with FTIs. The predictive validity of having a TSRS in the bottom 5% given a MDI <70 at 24 months was poor. A child who tested within the normal range (>85) at 24 months had an excellent chance of testing in the normal range at kindergarten.

Early Levallois technology and the Lower to Middle Paleolithic transition in the Southern Caucasus

The Lower to Middle Paleolithic transition (~400,000 to 200,000 years ago) is marked by technical, behavioral, and anatomical changes among hominin populations throughout Africa and Eurasia. The replacement of bifacial stone tools, such as handaxes, by tools made on flakes detached from Levallois cores documents the most important conceptual shift in stone tool production strategies since the advent of bifacial technology more than one million years earlier and has been argued to result from the expansion of archaic Homo sapiens out of Africa. Our data from Nor Geghi 1, Armenia, record the earliest synchronic use of bifacial and Levallois technology outside Africa and are consistent with the hypothesis that this transition occurred independently within geographically dispersed, technologically precocious hominin populations with a shared technological ancestry.

Testing for drugs of abuse in children and adolescents

Drug testing is often used as part of an assessment for substance use in children and adolescents. However, the indications for drug testing and guidance on how to use this procedure effectively are not clear. The complexity and invasiveness of the procedure and limitations to the information derived from drug testing all affect its utility. The objective of this clinical report is to provide guidance to pediatricians and other clinicians on the efficacy and efficient use of drug testing on the basis of a review of the nascent scientific literature, policy guidelines, and published clinical recommendations.

Discharge timing, outpatient follow-up, and home care of late-preterm and early-term infants

OBJECTIVE

To compare the timing of hospital discharge, time to outpatient follow-up, and home care practices (breastfeeding initiation and continuation, tobacco smoke exposure, supine sleep position) for late-preterm (LPT; 34 0/7-36 6/7 weeks) and early-term (ET; 37 0/7-38/6/7 weeks) infants with term infants.

METHODS

We analyzed 2000-2008 data from the Centers for Disease Control and Prevention's Pregnancy Risk Assessment Monitoring System. χ(2) Analyses were used to measure differences in maternal and infant characteristics, hospital discharge, outpatient care, and home care among LPT, ET, and term infants. We calculated adjusted risk ratios for the risk of adverse care outcomes among LPT and ET infants compared with term infants.

RESULTS

In the adjusted analysis, LPT infants were less likely to be discharged early compared with term infants, whereas there was no difference for ET infants (risk ratio [RR; 95% confidence interval (CI)]: 0.65 [0.54-0.79]; 0.95 [0.88-1.02]). [corrected]. LPT and ET infants were more likely to have timely outpatient follow-up (1.07 [1.06-1.08]; 1.02 [1.02-1.03]), more likely to experience maternal tobacco smoke exposure (1.09 [1.05-1.14]; 1.08 [1.06-1.11]), less likely to be initially breastfed (0.95 [0.94-0.97]; 0.98 [0.97-0.98]), less likely to be breastfed for ≥10 weeks (0.88 [0.86-0.90]; 0.94 [0.93-0.96]), and less likely to be placed in a supine sleep position (0.95 [0.93-0.97]; 0.97 [0.96-0.98]).

CONCLUSIONS

Given that LPT and ET infants bear an increased risk of morbidity and mortality, greater efforts are needed to ensure safe and healthy posthospitalization and home care practices for these vulnerable infants.

Neonatal intensive care unit discharge preparation, family readiness and infant outcomes: connecting the dots

Neonatal intensive care unit (NICU) discharge readiness is defined as the masterful attainment of technical skills and knowledge, emotional comfort, and confidence with infant care by the primary caregivers at the time of discharge. NICU discharge preparation is the process of facilitating comfort and confidence as well as the acquisition of knowledge and skills to successfully make the transition from the NICU to home. In this paper, we first review the literature about discharge readiness as it relates to the NICU population. Understanding that discharge readiness is achieved, in part, through successful discharge preparation, we then outline an approach to NICU discharge preparation.

Prenatal substance abuse: short- and long-term effects on the exposed fetus

Prenatal substance abuse continues to be a significant problem in this country and poses important health risks for the developing fetus. The primary care pediatrician's role in addressing prenatal substance exposure includes prevention, identification of exposure, recognition of medical issues for the exposed newborn infant, protection of the infant, and follow-up of the exposed infant. This report will provide information for the most common drugs involved in prenatal exposure: nicotine, alcohol, marijuana, opiates, cocaine, and methamphetamine.

The role of pulmonary follow-up in reducing health care utilization in infants with bronchopulmonary dysplasia

OBJECTIVE

To determine whether pulmonary follow-up affects rates of rehospitalization and visitations to emergency departments (EDs) in preterm infants with bronchopulmonary dysplasia (BPD).

METHODS

In this retrospective cohort study, the authors identified all preterm infants born at ≤ 32 weeks' gestation with at least one outpatient visit to a pulmonary follow-up clinic at Children's Hospital Boston or a high-risk primary neurodevelopmental follow-up clinic for preterm infants. ED visits and rehospitalizations were identified through electronic medical records.

RESULTS

Infants with pulmonary follow-up compared with infants without pulmonary follow-up were, respectively, younger (mean gestational age 26.3 ± 2.3 vs 28.3 ± 2.3 weeks, P < .0001), smaller at birth (birth weight <1200 g, 87.6% vs 57.2%, P < .0001), and needed more supplemental oxygen (55.7% vs 2.6%, P < .0001) and diuretics (65.8% vs 4.7%, P < .001) at the time of discharge from the neonatal intensive care unit. Although rates of rehospitalization were higher in infants with pulmonary follow-up, rates of visits to an ED for respiratory causes were not statistically significant. After controlling for baseline differences in both groups, the rates of rehospitalization or ED visits were the same for both groups.

CONCLUSIONS

Despite differences in lung disease status in infants with and without pulmonary follow-up, the rates of health care utilization were the same in both groups. Pulmonary follow-up may decrease the expected higher rates of ED visits and hospitalizations in preterm infants with more severe lung disease.

Neonatal intensive care unit discharge preparedness: primary care implications

OBJECTIVE

To investigate specific post-neonatal intensive care unit (NICU) discharge outcomes and issues for families.

STUDY DESIGN

The authors prospectively surveyed family's discharge preparedness at the infant's NICU discharge. In the weeks after the infant was discharged, families were interviewed by telephone for self-reported utilization of health services as well as any infant-associated problems or issues.

RESULTS

At discharge, 35 of 287 (12%) families were "unprepared" as defined by a Likert response of less than 7 by either the family member or nursing assessment. Unprepared families were more likely to report that their pediatrician could not access the infant's NICU hospital discharge summary, problems with the infant's milk/formula, and an inability to obtain needed feeding supplies.

CONCLUSIONS

Although most of the families are "prepared" for discharge at the time of discharge, this study highlights several issues that primary care providers accepting care and NICU staff discharging infants/families should be aware.

Prematurity: an overview and public health implications

The high rate of premature births in the United States remains a public health concern. These infants experience substantial morbidity and mortality in the newborn period, which translate into significant medical costs. In early childhood, survivors are characterized by a variety of health problems, including motor delay and/or cerebral palsy, lower IQs, behavior problems, and respiratory illness, especially asthma. Many experience difficulty with school work, lower health-related quality of life, and family stress. Emerging information in adolescence and young adulthood paints a more optimistic picture, with persistence of many problems but with better adaptation and more positive expectations by the young adults. Few opportunities for prevention have been identified; therefore, public health approaches to prematurity include assurance of delivery in a facility capable of managing neonatal complications, quality improvement to minimize interinstitutional variations, early developmental support for such infants, and attention to related family health issues.

Late preterm infants have worse 24-month neurodevelopmental outcomes than term infants

BACKGROUND

Late preterm infants (34-37 weeks' gestation) are often perceived at similar risks for morbidity and mortality as term infants.

OBJECTIVE

To compare the neurodevelopmental outcomes of late preterm to term infants.

METHODS

Our study sample of 6300 term and 1200 late preterm infants came from the Early Childhood Longitudinal Study-Birth Cohort. We used general estimating equations to get weighted odds of having developmental delay, mental index scores (MDI) or psychomotor index scores (PDI) < 70, at 24 months of age.

RESULTS

Late preterm infants compared with term infants had lower MDI (85 vs 89) and PDI (88 vs 92), both P < .0001, respectively. A higher proportion of late preterm infants compared with term infants had an MDI <70 (21% vs 16%; P < .0001). An equal number had PDIs <70 (6.1% vs 6.5%). After controlling for statistically significant and clinically relevant descriptive characteristics, late preterm infants still had higher odds of mental (odds ratio: 1.52 [95% confidence interval: 1.26-1.82] P < .0001) or physical (odds ratio: 1.56 [95% confidence interval: 1.30-1.89] P < .0001) developmental delay.

CONCLUSIONS

Late preterm infants have poorer neurodevelopmental outcomes than term infants and have increased odds to have a mental and/or physical developmental delay.

Infant weight gain and school-age blood pressure and cognition in former preterm infants

OBJECTIVES

More rapid infant weight gain may be associated with better neurodevelopment but also with higher blood pressure (BP). The objective of this study was to determine the extent to which infant weight gain is associated with systolic BP (SBP) and IQ at school age in former preterm, low birth weight infants.

METHODS

We studied 911 participants in the Infant Health and Development Program, an 8-center longitudinal study of children born at < or = 37 weeks' gestation and < or = 2500 g. Study staff weighed participants at term and at 4 and 12 months' corrected ages; measured BP 3 times at 6.5 years; and administered the Wechsler Intelligence Scale for Children, Third Edition (WISC-III), an IQ test, at 8 years. In linear regression, we modeled our exposure "infant weight gain" as the 12-month weight z score adjusted for the term weight z score.

RESULTS

Median (interquartile range) weight z score was -0.7 (-1.5 to -0.0) at 12 months. Mean + or - SD SBP at 6.5 years was 104.2 + or - 8.4 mmHg, and mean + or - SD WISC-III total score at 8 years was 91 + or - 18. Adjusting for child gender, age, and race and maternal education, income, age, IQ, and smoking, for each z score additional weight gain from term to 12 months, SBP was 0.7 mmHg higher and WISC-III total score was 1.9 points higher.

CONCLUSIONS

In preterm infants, there seem to be modest neurodevelopmental advantages of more rapid weight gain in the first year of life and only small BP-related effects.

Hypothyroidism in a breast-fed preterm infant resulting from maternal topical iodine exposure

Hypothyroidism developed in a preterm infant, whose initial screening thyroid function test results were normal, at 2 weeks of life. The infant's mother was packing her Caesarian incision with iodine soaked gauze, resulting in a markedly increased breast milk iodine concentration. Treatment with oral L-thyroxine normalized thyroid function tests.

Computerized color-vision test based upon postreceptoral channel sensitivities

An automated, computerized color-vision test was designed to diagnose congenital red–green color-vision defects. The observer viewed a yellow appearing CRT screen. The principle was to measure increment thresholds for three different chromaticities, the background yellow, a red, and a green chromaticity. Spatial and temporal parameters were chosen to favor parvocellular pathway mediation of thresholds. Thresholds for the three test stimuli were estimated by four-alternative forced-choice (4AFC), randomly interleaved staircases. Four 1.5-deg, 4.2 cd/m2square pedestals were arranged as a 2 × 2 matrix around the center of the display with 15-minute separations. A trial incremented all four squares by 1.0 cd/m2for 133 ms. One randomly chosen square included an extra increment of a test chromaticity. The observer identified the different appearing square using the cursor. Administration time was ∼5 minutes. Normal trichromats showed clear Sloan notch as defined by log (ΔY/ΔR), whereas red–green color defectives generally showed little or no Sloan notch, indicating that their thresholds were mediated by their luminance system, not by the chromatic system. Data from 107 normal trichromats showed a mean Sloan notch of 0.654 (SD = 0.123). Among 16 color-vision defectives tested (2 protanopes, 1 protanomal, 6 deuteranopes, & 7 deuteranomals), the Sloan notch was between −0.062 and 0.353 for deutans and was <−0.10 for protans. A sufficient number of color-defective observers have not yet been tested to determine whether the test can reliably discriminate between protans and deutans. Nevertheless, the current data show that the test can work as a quick diagnostic procedure (functional trichromatism or dichromatism) of red–green color-vision defect.

Trends in severe bronchopulmonary dysplasia rates between 1994 and 2002

OBJECTIVE

To examine temporal trends in the rates of severe bronchopulmonary dysplasia (BPD) between 1994 and 2002.

STUDY DESIGN

In a retrospective cohort study, all infants with a gestational age (GA) <33 weeks in a large managed care organization were identified. Annual rates of BPD (defined as an oxygen requirement at 36 weeks corrected GA), severe BPD (defined as respiratory support at 36 weeks corrected GA), and death before 36 weeks corrected GA were examined.

RESULTS

Of the 5115 infants in the study cohort, 603 (12%) had BPD, including 246 (4.9%) who had severe BPD. There were 481 (9.5%) deaths before 36 weeks corrected GA. Although the decline in BPD in this period was not significant, the rates of severe BPD declined from 9.7% in 1994 to 3.7% in 2002. Controlling for gestational age, the odds ratio (95% CI) for annual rate of decline in severe BPD was 0.890 (0.841-0.941). Controlling for gestational age, deaths before 36 weeks corrected GA also declined, with the odds ratio (CI) for the annual decline being 0.944 (0.896-0.996).

CONCLUSIONS

In this study population, the odds of having of BPD remained constant after controlling for GA. However, the odds of having severe BPD declined on average 11% per year between 1994 and 2002.

Rehospitalization in the first year of life among infants with bronchopulmonary dysplasia

OBJECTIVE

To describe rates and identify risk factors for rehospitalization during the first year of life among infants with bronchopulmonary dysplasia (BPD).

STUDY DESIGN

This was a retrospective cohort study of infants born at a gestational age (GA) <33 weeks, between 1995 and 1999. BPD was defined as requirement of supplemental oxygen and/or mechanical ventilation at 36 weeks' corrected GA. The outcome was rehospitalization for any reason before first birthday.

RESULTS

In the first year of life, 118 of 238 (49%) infants with BPD were rehospitalized, more than twice the rate of rehospitalization of the non-BPD population, which was 309 of 1359 (23%) (P=<.0001). No measured factor discriminated between those infants with BPD who were and were not rehospitalized, even when only rehospitalizations for respiratory diagnoses were considered.

CONCLUSIONS

Among premature infants, BPD substantially increases the risk of rehospitalization during the first year of life. Neither demographic nor physiologic factors predicted rehospitalization among the infants with BPD. Other factors, such as air quality of home environment, passive smoking exposure, respiratory syncytial virus prophylaxis, breast-feeding status, and/or parenting and primary care management styles, should be examined in future studies.

Brightness induction from rods

Rod modulation of an annular surround can produce brightness contrast in a test field centered at 100 from the fovea. In our research, stimuli originated from a colorimeter that provided 4 primaries in both the circular test and the annular surround fields, and allowed independent modulation of the rods and each of the short (S)-, middle (M)-, and long (L)-wavelength-sensitive cone types. The chromaticity was set so fields had the same appearance as the equal energy spectrum. At 1 photopic troland (td), rod-induced modulation in the test field could be cancelled by either a rod- or a cone-nulling modulation added to the test field. The best cone nulling of rod induction showed residual flicker. Nulling was more effective, though still imperfect, with a cone-nulling stimulus of higher S-cone modulation contrast. Rod induction with square-wave, on-pulse, and off-pulse temporal profiles was closely similar. At higher light levels, 10 and 100 td, rod contrast could not be nulled by rod or cone modulation. The failure to achieve nulls may have been caused by either or both of the following hypotheses: (1) there is a mismatch between the rod and cone temporal waveforms; (2) there is strong rod input to the magnocellular pathway, but negligible rod input to the parvocellular pathway, as shown by single-unit electrophysiological data.

Rod-cone interactions assessed in inferred magnocellular and parvocellular postreceptoral pathways

Interactions between receptor-isolating rod and long (L)- or middle (M)-wavelength-sensitive cone modulations at 2 Hz and 10 Hz were analyzed in terms of underlying inferred magnocellular (MC) and parvocellular (PC) postreceptoral pathways. Stimuli originated from a colorimeter with 4 primaries in both the center and surround fields. The first experiment employed a phase paradigm in which the thresholds for mixed rod and cone modulations were measured as a function of relative phase. The amplitudes of the rod and cone modulations, equated in threshold units, were varied in tandem. In the second experiment, thresholds for mixed rod and cone modulations were measured as a function of the ratio of the rod and cone modulation amplitudes for 2 fixed phase offsets. Both experiments yielded similar interpretations of rod and L- (or M-) cone interactions. At 1 and 10 troland (td), rod and L- (or M-) cone interactions varied depending on the postreceptoral pathways underlying the detection. When cone thresholds were mediated by the inferred MC pathway, rod and cone thresholds showed almost linear summation. When cone thresholds were mediated by the inferred PC pathway, rod and cone thresholds showed probability summation. Assuming that signals within the same pathway follow linear summation, and signals traveling in different pathways follow probability summation, we concluded that the rod thresholds were mediated by the inferred MC pathway for both the 2-Hz and 10-Hz conditions.

The effects of air flow and stem flexure on the mechanical and hydraulic properties of the stems of sunflowers Helianthus annuus L

Many studies have shown that wind affects plant development, causing them to develop shorter and usually stronger stems. Many of these effects have been shown to be due to a response to mechanical flexing of the stem which is known as thigmomorphogenesis. However, it is not known how wind affects the hydraulic properties of stems, nor have the effects of air flow past leaves been examined in isolation from mechanical flexing. This study, therefore, used a factorial experiment to distinguish between the effects of stem flexing and air flow, and examined the morphology, hydraulics and mechanics of developing sunflowers Helianthus annuus. It was found that flexure and air flow had opposite effects on several aspects of development; air flow increased plant height and length-specific stem hydraulic conductivity, k(h), and reduced stem rigidity and strength, while flexing did the reverse. There was also a clear trade-off between hydraulic and mechanical capability: as one increased the other decreased. A plant's response to wind must, therefore, be a complex response to at least two different stimuli and this might help explain why it varies with species and environment.

Reactive stroma in human prostate cancer: induction of myofibroblast phenotype and extracellular matrix remodeling

PURPOSE

Generation of a reactive stroma environment occurs in many human cancers and is likely to promote tumorigenesis. However, reactive stroma in human prostate cancer has not been defined. We examined stromal cell phenotype and expression of extracellular matrix components in an effort to define the reactive stroma environment and to determine its ontogeny during prostate cancer progression.

EXPERIMENTAL DESIGN

Normal prostate, prostatic intraepithelial neoplasia (PIN), and prostate cancer were examined by immunohistochemistry. Tissue samples included radical prostatectomy specimens, frozen biopsy specimens, and a prostate cancer tissue microarray. A human prostate stromal cell line was used to determine whether transforming growth factor beta1 (TGF-beta1) regulates reactive stroma.

RESULTS

Compared with normal prostate tissue, reactive stroma in Gleason 3 prostate cancer showed increased vimentin staining and decreased calponin staining (P < 0.001). Double-label immunohistochemistry revealed that reactive stromal cells were vimentin and smooth muscle alpha-actin positive, indicating the myofibroblast phenotype. In addition, reactive stroma cells exhibited elevated collagen I synthesis and expression of tenascin and fibroblast activation protein. Increased vimentin expression and collagen I synthesis were first observed in activated periacinar fibroblasts adjacent to PIN. Similar to previous observations in prostate cancer, TGF-beta1-staining intensity was elevated in PIN. In vitro, TGF-beta1 stimulated human prostatic fibroblasts to switch to the myofibroblast phenotype and to express tenascin.

CONCLUSIONS

The stromal microenvironment in human prostate cancer is altered compared with normal stroma and exhibits features of a wound repair stroma. Reactive stroma is composed of myofibroblasts and fibroblasts stimulated to express extracellular matrix components. Reactive stroma appears to be initiated during PIN and evolve with cancer progression to effectively displace the normal fibromuscular stroma. These studies and others suggest that TGF-beta1 is a candidate regulator of reactive stroma during prostate cancer progression.

The innervation of the human antro-pyloric region: Organization and composition

Although the composition of the gastric innervation has been determined in animal models, relatively little known about the innervation of the human antro-pyloric region. We used immunocytochemical techniques to establish the localization and co-expression of neuropeptides and nitric oxide in the human antrum and upper duodenum. Our results demonstrate the existence of a clearly defined submucosal plexus in the antral region that is absent in rats and guinea pigs. The abundant innervation of the lamina propria contains 3 major nerve populations: VIP- and NOS-, SP- and CGRP-, and GRP-immunoreactive. For the first time, NOS-containing nerve fibers were observed throughout the length of the antral glands. Within the antrum somatostatin was confined to endocrine cells, however, at the pyloric sphincter both enteric plexi contained immunoreactive neurons and nerve fibres. Within the pyloric sphincter CGRP- and SP-immunoreactive fibres were significantly increased, correlating with the presence of large ganglia in the submucosal plexus. In conclusion, the organization and composition of the innervation of human antro-pylorus differed substantially from that reported in other mammals. The presence of an abundant mucosal innervation paralled by a well-defined submucosal plexus indicates that the functional regulation of the gastric–pyloric region will be distinct from that of smaller animal models.Key words: gastric innervation, pyloric sphincter, neuropeptides, nitric oxide, somatostatin.

The innervation of the human antro-pyloric region: organization and composition

Although the composition of the gastric innervation has been determined in animal models, relatively little known about the innervation of the human antro-pyloric region. We used immunocytochemical techniques to establish the localization and co-expression of neuropeptides and nitric oxide in the human antrum and upper duodenum. Our results demonstrate the existence of a clearly defined submucosal plexus in the antral region that is absent in rats and guinea pigs. The abundant innervation of the lamina propria contains 3 major nerve populations: VIP- and NOS-, SP- and CGRP-, and GRP-immunoreactive. For the first time, NOS-containing nerve fibers were observed throughout the length of the antral glands. Within the antrum somatostatin was confined to endocrine cells, however, at the pyloric sphincter both enteric plexi contained immunoreactive neurons and nerve fibres. Within the pyloric sphincter CGRP- and SP-immunoreactive fibres were significantly increased, correlating with the presence of large ganglia in the submucosal plexus. In conclusion, the organization and composition of the innervation of human antro-pylorus differed substantially from that reported in other mammals. The presence of an abundant mucosal innervation paralled by a well-defined submucosal plexus indicates that the functional regulation of the gastric-pyloric region will be distinct from that of smaller animal models.

Pulse and steady-pedestal contrast discrimination: effect of spatial parameters

The goal of this study was to establish the spatial summation properties associated with inferred PC- and MC-pathway mediated psychophysical contrast discrimination. Previous work has established two paradigms that reveal characteristic signatures of these pathways. In the pulse paradigm, a four-square array was pulsed briefly, on a constant background. In the steady-pedestal paradigm, the stimulus array was presented continuously as a steady-pedestal within a constant surround. In both paradigms, one square differed from the others, giving the observer a forced choice spatial discrimination task. Area summation functions derived for the pulse paradigm decreased with area, with a slope of -0.25 on a log-log axis. Area summation functions derived for the steady-pedestal paradigm decreased as a power function of area, approaching an asymptote above one square degree. The latter are consistent with the classical data of threshold spatial summation.

The role of spatial frequency in color induction

Color induction was measured for test and inducing chromaticities presented in spatial square-wave alternation, with spatial frequencies of 0.7, 4.0, 6.0 and 9.0 cpd. Observers matched the test chromaticities to a rectangular matching field using haploscopic presentation. Data were collected and analyzed within the framework of a cone chromaticity space, allowing analysis of spatial frequency effects on post-receptoral spectral opponent pathways. Assimilation, a shift of chromaticity toward the inducing chromaticity, was found at the highest spatial frequency (9.0 cpd). Contrast, a shift of chromaticity away from the inducing chromaticity, occurred at the lowest spatial frequency (0.7 cpd). The spatial frequency at the transition point from assimilation to contrast was near 4 cpd, independent of the cone axis. Assimilation was unaffected by the presence of a neutral surround and could be described by a spread light model. Contrast was reduced in the presence of a neutral surround. The data suggested that retinal contrast signals are important determinants in the perception of chromatic contrast.

Contrast discrimination deficits in retinitis pigmentosa are greater for stimuli that favor the magnocellular pathway

Luminance contrast discrimination was measured in 14 patients with retinitis pigmentosa (RP) and 14 control observers with normal vision, using steady-pedestal and pulsed-pedestal paradigms [Pokorny, J., & Smith, V. C. (1997). Psychophysical signatures associated with magnocellular and parvocellular pathway contrast gain. Journal of the Optical Society of America A, 14, 2477-2486] to bias performance toward the magnocellular (MC) or parvocellular (PC) pathway, respectively. The aim was to determine the relative effects of retinal degeneration on MC- and PC-pathway function in RP. For five of the RP patients, contrast discrimination thresholds were within normal limits for both the steady-pedestal and pulsed-pedestal paradigms. The other nine RP patients showed threshold elevations for the steady-pedestal paradigm (presumed magnocellular mediation), whereas their thresholds for the pulsed-pedestal paradigm (presumed parvocellular mediation) were within normal limits for all but the two patients who had the most extreme threshold elevations using the steady-pedestal paradigm. A control experiment on four of the RP patients, using a greater number of pedestal contrasts, verified that the patients' thresholds for the pulsed-pedestal paradigm showed the pattern expected for contrast discrimination mediated by the PC pathway. The higher threshold elevations for the steady-pedestal paradigm than for the pulsed-pedestal paradigm indicate that the retinal degeneration that occurs in RP predominantly disrupts contrast discrimination under stimulus conditions that favor the MC pathway.

The consequences of opponent rectification: the effect of surround size and luminance on color appearance

Smith and Pokorny (Vision Res. 36 (1996) 3087.) described conditions under which chromatic contrast induction can reveal a hiatus, a region of chromaticity space which appears neither reddish nor greenish when presented in a chromatic equiluminant surround. The current study investigated the effect of varying the size and the luminance of the inducing surround. The color appearance of test stimuli in chromatic surrounds was assessed by asymmetric color matching to a comparison display. Equiluminant (12 cd/m(2)), 1 degrees square stimuli were generated on a CRT display and presented haploscopically. Ten test fields varied in their L-cone excitation along a constant S-cone line. The chromatic surrounds were of either high (red) or low (green) L-cone excitation on a constant S-cone line. In Experiment 1, surrounds were 1.1 degrees, 1.5 degrees, 2.0 degrees, or 3.0 degrees square (surround widths of 3', 15', 30', 1 degrees ). In Experiment 2, the test and comparison surrounds were at higher (16.7 cd/m(2)) or lower (8.3 cd/m(2)) retinal illuminance than the test field. Contrast induction reached an asymptote for surround widths of 30' or larger. The amount of induction decreased for the surround widths of 15' and 3'. The hiatus was present for the larger surrounds and decreased as surround size decreased. The use of a higher or lower surround luminance did not affect the magnitude of induction or the size of the hiatus.

Primate horizontal cell dynamics: an analysis of sensitivity regulation in the outer retina

The human cone visual system maintains sensitivity over a broad range of illumination, from below 1 troland to 1,000,000 trolands. While the cone photoreceptors themselves are an important locus for sensitivity regulation-or light adaptation-the degree to which they contribute in primates remains unclear. To determine the range of sensitivity regulation in the outer retina, the temporal dynamics, neural gain control, and response range compression were measured in second-order neurons, the H1 horizontal cells, of the macaque retina. Situated at the first synapse in the retina, H1 cells receive input from a large population of cones. Lee et al. have previously shown that sensitivity regulation in H1 cells is both cone type-specific and spatially restricted. The sensitivity regulation seen in H1 cells at moderate illuminances thus takes place before the summation of cone signals in these cells, and the data establish the H1 cell as a convenient locus for analyzing cone signals. In the present study, cone-driven responses of primate H1 cells to temporally modulated sine-wave stimuli and to increment pulses were measured at steady levels of 1-1,000 trolands. The H1 cell gave a modulated response to sine-wave stimuli and hyperpolarized to increment pulses with overshoots at stimulus onset and offset. The temporal amplitude sensitivity function was primarily low-pass in shape, with a small degree of low-frequency roll off and a resonance shoulder near 40 Hz. A model incorporating a cascade of first-order filters together with an underdamped second-order filter could describe both temporal sinusoidal and pulse hyperpolarizations. Amplitude sensitivity was estimated from both pulse and sine-wave data as a function of the steady adaptation level. Sensitivity at low light levels (1 troland) showed a slowing in temporal dynamics, indicating time-dependent sensitivity regulation. Sensitivity was reduced at light levels above approximately 10 trolands, reflecting both response range compression and neural gain control. Thus the outer retina is a major locus for sensitivity regulation in primates.

Characteristics of Helicobacter pylori attachment to human primary antral epithelial cells

Conventional cell lines are commonly used to study infection characteristics of the human gastric pathogen Helicobacter pylori. We sought to investigate bacterial attachment to human antral primary epithelial cells, a cell model that more closely resembles the human stomach than transformed cell lines. Primary cells were infected for 24 and 48 h with H. pylori. Morphological appearance of both the pathogen and the cells as well as features of colonization, attachment and internalization were evaluated by electron microscopy and compared to features observed with cultured AGS cells. H. pylori exhibited various shapes during colonization including the spiral, U-shaped, donut, and coccoid forms. The prevalence of each form seemed to be dependent on the infected donor tissue but, in general, changed with time to the coccoid form. Bacterial cell membranes progressively enlarged and appeared at times to be connected with microvilli. Bacterial attachment occurred to cells that were either unchanged, or had formed cup-like structures. Simultaneously, outer membrane vesicles were increasingly secreted from the bacteria, coinciding with increased cellular damage. We conclude that bacterial shape conversion, adherence and secretion of outer membrane vesicles are features of H. pylori infection. Primary gastric cell cultures closely imitate the antral environment and present an appropriate and useful model to study H. pylori pathogenesis.

Role of Helicobacter pylori gastritis in gastric atrophy, intestinal metaplasia, and gastric neoplasia

Helicobacter pylori is the major cause of chronic gastritis worldwide. With an estimated rate of infection of over one half of the world's population, it is responsible for extensive morbidity and mortality. Infection with this organism does not appear to spontaneously resolve. Instead it reaches a chronic stage from which a number of outcomes are possible. This article reviews those outcomes that have been linked to H. pylori and explores the pathogenesis while attempting to resolve the discrepant paths infection can take. The associations include duodenal and gastric ulcers and the majority of gastric lymphomas of B-cell type derived from the mucosa-associated lymphoid tissue (MALT). Chronic gastritis has also been shown to evolve into atrophy with intestinal metaplasia in certain populations. This change in the gastric epithelium has been linked with an increased risk of gastric adenocarcinoma. Microsc. Res. Tech. 48:313-320, 2000. Published 2000 Wiley-Liss, Inc.

Unilocular retroperitoneal cyst of mesothelial origin presenting as a renal mass

We report the first 2 cases, to our knowledge, of retroperitoneal cysts with features of mesothelial differentiation that clinically mimic renal masses. The first lesion occurred in a 71-year-old man who presented with flank pain. Ultrasound and magnetic resonance imaging studies showed a unilocular cystic structure arising from the upper pole of the left kidney. The second lesion was in a 44-year-old woman who presented with left flank pain. Imaging studies revealed an 8-cm hemorrhagic cyst at the lower pole of the left kidney. Histologic examination of the nephrectomy specimens in each case revealed a unilocular cyst with intracystic and pericystic hemorrhage. In each case, the cyst was lined by a single layer of cells with ample eosinophilic cytoplasm and benign nuclear features without mucinous or müllerian differentiation. Histochemical staining showed Alcian blue positivity on the cell surface, which was sensitive to hyaluronidase digestion. Intracytoplasmic mucin, however, was not detected. Immunostaining showed that the cyst lining cells were positive for keratin, vimentin, HBME-1, WT1, and thrombomodulin but negative for carcinoembryonic antigen, B72.3, Leu-M1, and BerEP4. The first case was positive for calretinin, whereas the second was negative. These findings support the mesothelial nature of the cysts.

Role of Helicobacter pylori gastritis in gastric atrophy, intestinal metaplasia, and gastric neoplasia

Helicobacter pylori is the major cause of chronic gastritis worldwide. With an estimated rate of infection of over one half of the world's population, it is responsible for extensive morbidity and mortality. Infection with this organism does not appear to spontaneously resolve. Instead it reaches a chronic stage from which a number of outcomes are possible. This article reviews those outcomes that have been linked to H. pylori and explores the pathogenesis while attempting to resolve the discrepant paths infection can take. The associations include duodenal and gastric ulcers and the majority of gastric lymphomas of B-cell type derived from the mucosa-associated lymphoid tissue (MALT). Chronic gastritis has also been shown to evolve into atrophy with intestinal metaplasia in certain populations. This change in the gastric epithelium has been linked with an increased risk of gastric adenocarcinoma. Microsc. Res. Tech. 48:313-320, 2000. Published 2000 Wiley-Liss, Inc.

Cellular expression of the neurokinin 1 receptor in the human antrum

The localization of the neurokinin 1 receptor in rat and guinea pig gastrointestinal tract has been extensively studied but not in human tissues. The present study used antibodies to characterize the cellular expression of neurokinin 1 receptors in human antrum. Cryostat sections (40-80 microm) were immunostained for the neurokinin 1 receptor double labeled with substance P, von Willebrand's factor, c-kit, fibronectin, S-100, serotonin, gastrin and somatostatin. Neurokinin 1 receptor-immunoreactivity was observed on neurons within the myenteric and submucosal plexuses surrounded by substance P-immunoreactive fibers and on von Willebrand's factor-immunoreactive endothelial cells lining blood vessels throughout the antral wall. c-Kit-immunoreactive interstitial cells of Cajal and gastrin cells were co-stained by the monoclonal neurokinin 1 receptor antibody. Finally, there was no evidence for the presence of the neurokinin 1 receptor on fibroblasts, Schwann, somatostatin, serotonin or smooth muscle cells. This study clearly demonstrates an expanded cellular expression of the neurokinin 1 receptor in the human antrum.