High 1-h glucose in youths with obesity as marker of prediabetes and cardiovascular risk.

PURPOSE: Testing 1-h glucose (1HG) concentration during oral glucose tolerance test is cost-effective to identify individuals at risk of incident type 2 diabetes. Aim of the study was to define 1HG cutoffs diagnostic of incident impaired glucose tolerance (IGT) in youths with obesity, and to evaluate prevalence and association of cutoffs identified in the cohort and from the literature (133 and 155 mg/dl) to cardiovascular disease (CVD) in a population of youths with obesity. METHODS: This is a longitudinal study of 154 youths to identify 1HG cutoffs, and cross-sectional study of 2295 youths to estimate prevalence of high 1HG and association to CVD. Receiver-operating characteristic curves (ROC) were used to establish 1HG cutoffs, and univariate regression analyses to test association of 1HG to blood pressure, lipids and aminotransferases. RESULTS: ROC analysis identified the 1HG cutoff of 159 mg/dl as having diagnostic accuracy of IGT with area under the ROC 0.82 (95% CI 0.66-0.98), sensitivity 0.86% and specificity 0.79%. In the cross-sectional population, prevalence of high 1HG was 36% and 15% for 133 and 155 mg/dl cutoffs, respectively, and 17% for the 159 mg/dl value. All the examined cutoffs were significantly associated with worse lipid profile, liver function test, reduced insulin sensitivity, secretion and disposition index. CONCLUSION: High 1HG is marker of persistent IGT and increased risk of metabolic abnormalities in youths. The 155 mg/dl cutoff is a convenient estimate in young people but longitudinal studies with retinopathy and overt diabetes as end points are advised to verify the 1HG cutoff with the best diagnostic accuracy.

CPAP by helmet for treatment of acute respiratory failure after pediatric liver transplantation.

ARF after pediatric liver transplantation accounts for high rate of morbidity and mortality associated with this procedure. The role of CPAP in postoperative period is still unknown. The aim of the study was to describe current practice and risk factors associated with the application of helmet CPAP. In this retrospective observational cohort study, 119 recipients were divided into two groups based on indication to CPAP after extubation. Perioperative variables were studied, and determinants of CPAP application were analyzed in a multivariate logistic model. Sixty patients (60/114) developed ARF and were included in the CPAP group. No differences were found between the two groups for primary disease, graft type, and blood product transfused. At multivariate analysis, weight <11 kg (OR = 2.9; 95% CI = 1.1-7.3; P = .026), PaO2 /FiO2 <380 before extubation (OR = 5.4; 95% CI = 2.1-13.6; P < .001), need of vasopressors (OR = 2.6; 95% CI = 1.1-6.4; P = .038), and positive fluid balance >148 mL/kg (OR = 4.0; 95% CI = 1.6-10.1; P = .004) were the main determinants of CPAP application. In the CPAP group, five patients (8.4%) needed reintubation. Pediatric liver recipients with lower weight, higher need of inotropes/vasopressors, higher positive fluid balance after surgery, and lower PaO2 /FiO2 before extubation were at higher odds of developing ARF needing CPAP application.

A comparison between linguistic skills and socio-communicative abilities in Williams syndrome.

BACKGROUND: Individuals with Williams syndrome (WS) show a disharmonic linguistic profile with a clear pattern of strengths and weaknesses. Despite their sociable nature, atypical socio-communicative abilities and deficits in communication and relationship with others have been found. AIM: The aim of the present study was to investigate whether linguistic skills (LS) were in line with the pragmatic and social use of language and the cognitive development of 32 individuals with WS (18 boys and 14 girls) with a mean chronological age of 12.3 (±4.4) years. To examine the relationship between language and mental age (MA) at different ages, the issue was investigated in children and adolescents/young adults with WS. METHOD: Measures of LS, including lexical and morphosyntactic competences, and adaptive socio-communicative abilities (ASCA), pertaining to the use of language in daily living social context, were compared with the MA of participants. In a second step, participants with WS were split into two subgroups based on age, and the relationship between LS, ASCA and MA was studied. RESULTS: Although expressive and receptive LS were generally found to be in line with or better than would be expected for MA, specific deficits in receptive ASCA were documented. LS and ASCA appeared to have a different evolution during the different time windows considered. CONCLUSIONS: Our results underlined the importance of assessing linguistic abilities in the context of adaptive functioning, to guide educational and rehabilitative strategies for individuals with WS.

Short-term neurodevelopmental outcome of babies operated on for low-risk esophageal atresia: a pilot study.

Data on the neurodevelopmental outcome of esophageal atresia (EA) survivors are scarce, controversial, and based on small samples. This is an observational prospective longitudinal study on a selected cohort of low-risk EA survivors. We considered a low-risk EA survivor a patient with the following characteristics: gestational age >32 weeks, no long gap, no genetic or chromosomic anomaly associated with neurodevelopmental delay, and no further major surgical congenital anomalies. Infants were evaluated with scales derived from the Bayley Scales of Infant and Toddler Development - 3rd Edition at 6 and 12 months, with a score of 100 considered normal for each scale. Analysis of variance was used to assess differences of cognitive and motor development. Linear regression was used to assess the impact of the following clinical and sociodemographic variables: gender, birthweight, gestational age, length of hospital stay, number of surgeries and number of esophageal dilatations during first hospitalization, days of mechanical ventilation, weight at follow up, number of surgeries and esophageal dilatations at follow up, parental age, educational level, and socioeconomic status. Thirty children form the object of the study. The mean (standard deviation [SD]) cognitive scale's score was 93.7 (7.5) and 98.2 (9.6) at 6 and 12 months, respectively (P < 0.05). The mean (SD) motor scale's score was 97.6 (9.3) and 98.0 (12.1) at 6 and 12 months, respectively (P = n.s.). Children with a body weight <5° percentile at 12 months showed a mean (SD) cognitive score significantly lower when compared with those with a body weight >5° percentile: 88.8 (6.3) and 100.5 (8.9), respectively. At 12 months, children with unemployed mothers had a mean (SD) motor score significantly lower when compared with those in the other socioeconomic classes: 87.7 (9.8) and 100.6 (12.4), respectively. In conclusion, parents of babies operated on for low-risk EA can be reassured about neurodevelopmental outcome at least up to 1 year of age. When offering a multidisciplinary follow-up program, underweight patients should deserve particular attention to promote their quality of life and support their global development.

Incidence and risk factors of bacterial sepsis and invasive fungal infection in neonates and infants requiring major surgery: an Italian multicentre prospective study.

BACKGROUND: Limited data are currently available on the incidence rates and risk factors for bacterial sepsis and invasive fungal infections (IFIs) among neonates and infants undergoing major surgery. AIM: To assess the incidence of bacterial sepsis and IFI, fungal colonization, risk factors for sepsis, and mortality in neonates and infants aged <3 months undergoing major surgery. METHODS: A multicentre prospective study was conducted involving 13 level-3 neonatal intensive care units in Italy, enrolling all infants aged ≤3 months undergoing major surgery. FINDINGS: From 2018 to 2021, 541 patients were enrolled. During hospitalization, 248 patients had a bacterial infection, and 23 patients had a fungal infection. Eighty-four patients were colonized by fungal strains. Overall, in-hospital mortality was 2.8%, but this was higher in infected than in uninfected infants (P = 0.034). In multivariate analysis, antibiotic exposure before surgery, ultrasound-guided or surgical placement of vascular catheters, vascular catheterization duration, and gestational age ≤28 weeks were all associated with bacterial sepsis. The risk of IFI was markedly higher in colonized infants (odds ratio (OR): 8.20; P < 0.001) and was linearly associated with the duration of vascular catheterization. Fungal colonization in infants with abdominal surgery increased the probability of IFI 11-fold (OR: 11.1; P < 0.001). CONCLUSION: Preventive strategies such as early removal of vascular catheters and the fluconazole prophylaxis should be considered to prevent bacterial and fungal sepsis in infants undergoing abdominal surgery, and even more so in those with fungal colonization.

Acute toxic exposures in children: analysis of a three year registry managed by a Pediatric poison control Center in Italy.

INTRODUCTION: Acute pediatric poisoning is an emerging health and social problem. The aim of this study is to describe the characteristics of a large pediatric cohort exposed to xenobiotics, through the analysis of a Pediatric Poison Control Center (PPCc) registry. METHODS: This study, conducted in the Pediatric Hospital Bambino Gesù of Rome, a reference National Pediatric Hospital, collected data of children whose parents or caregivers contacted the PPCc by phone (group "P"), or who presented to the Emergency Department (group "ED"), during the three-year period 2014-2016. Data were prospectively and systematically collected in a pre-set electronic registry. Comparisons among age groups were performed and multivariable logistic regression models used to investigate associations with outcomes (hospital referral for "P", and hospital admission for "ED"group). RESULTS: We collected data of 1611 children on group P and 1075 on group ED. Both groups were exposed to both pharmaceutical and non-pharmaceutical agents. Pharmaceutical agent exposure increased with age and the most common route of exposure was oral. Only 10% among P group were symptomatic children, with gastrointestinal symptoms. Among the ED patients, 30% were symptomatic children mostly with gastrointestinal (55.4%) and neurologic symptoms (23.8%). Intentional exposure (abuse substance and suicide attempt), which involved 7.7% of patients, was associated with older age and Hospital admission. CONCLUSIONS: Our study describes the characteristics of xenobiotics exposures in different paediatric age groups, highlighting the impact of both pharmacological and intentional exposure. Furthermore, our study shows the utility of a specific PPCc, either through Phone support or by direct access to ED. PPCc phone counselling could avoid unnecessary access to the ED, a relevant achievement, particularly in the time of a pandemic.

Performance of a component-based allergen-microarray in the diagnosis of cow's milk and hen's egg allergy.

BACKGROUND: The food challenge test (FCT) is the gold standard for the diagnosis of food allergy. This procedure is time consuming, costly and can induce potentially severe symptoms. An ideal in vitro test should allow to avoid the FCT. Objective To assess the clinical performance of microarray for specific IgE (sIgE) detection in children with challenge-proven/excluded cow's milk (CM) or hen's egg (HE) allergy. METHODS: One-hundred and four children with suspected IgE-mediated hypersensitivity to CM or HE were studied. In all patients, skin prick test, ImmunoCAP, microarray and FCT were performed. RESULTS: The microarray components Bos d 8 for CM (27/58 patients) and Gal d 1 (20/46 patients) and Gal d 2 (24/46) for HE were the most frequently recognized allergens. Using the FCT results as the reference parameter, sIgE to Bos d 8 and Gal d 1 had the highest area under the curves. These were not significantly different from those obtained using the ImmunoCAP. Use of 95% clinical decision points (CDP) for sIgE to Bos d 8 and Gal d 1 resulted in higher negative predictive values (78% and 79%, respectively) than those obtained with the ImmunoCAP (57% and 59%). CONCLUSIONS: Our results show that in children with suspected CM or HE allergy, the microarray has a good ability to predict the FCT results. In a clinical application perspective, the microarray could be used as a second-level assay, if the ImmunoCAP sIgE is <95% CDP. This approach would lead to a decrease in the number of the FCT to be performed, as well as of positive FCTs with a subsequent decrease in severe reaction risk.

Ultrasonographic assessment of mediastinal shift angle (MSA) in isolated left congenital diaphragmatic hernia for the prediction of postnatal survival.

Objectives: To quantify mediastinal shift in isolated congenital diaphragmatic hernia (CDH), by the introduction of a new ultrasonographic (US) marker, defined as mediastinal shift angle (MSA) and to evaluate its ability in predicting postnatal survival at discharge.Methods: Twenty-four consecutive fetuses from singleton pregnancies with isolated left-sided CDH were included in the study group and then subdivided into group A (16 survivors) and group B (8 nonsurvivors). The study group was matched with a control group of 95 fetuses from singleton pregnancies free from structural and/or chromosomal anomalies. On the same US stored images commonly used for lung-to-head ratio (LHR) measurement, a landmark line was drawn from a point on the posterior face of the vertebral body, splitting it into two equal parts, to the mid-posterior surface of the sternum. Another landmark line was then traced from the same point of the vertebral body to touch tangentially the lateral wall of the right atrium. The angle between these two lines was used to quantify mediastinal shift and called "mediastinal shift angle" (MSA).Results: Median MSA was significantly different between group A (34.3° range 29.3-45.9°) and group B (42.7° range 34.1-58.9°) (p < .001) and between study group as a whole and the control group (19° range 13.8-25.9°) (p < .001). Statistical analysis confirmed an inverse correlation between MSA values and survival (p = .004). The best cutoff value for MSA was 43.7°, which demonstrated the highest discriminatory power (sensitivity 63%; specificity 93.75%).Conclusions: In fetuses with isolated CDH, the mediastinal shift may be quantified using mediastinal shift angle (MSA) and this US marker, similarly to the widely accepted and used US prenatal prognostic indicators (LHR and O/E LHR), seems to reliably predict survival.

Growth hormone response to physical exercise in growing patients with classic congenital adrenal hyperplasia.

Glucocorticoid over-treatment in children with congenital adrenal hyperplasia (CAH) may suppress GH secretion and growth. Aims of our study were: 1) to evaluate post-exercise GH response in patients affected by CAH due to 21-hydroxylase deficiency, in comparison with a group of healthy subjects; 2) to investigate the relationship between the hormonal markers of adequate steroid therapy and GH secretion. We evaluated GH secretion every 6 months in 20 young CAH patients (8 girls, 12 boys). Mean follow-up was 4.6+/-0.9 yr (107 tests performed, 5.35+/-2.05 repeated tests for each patient). Forty-four healthy subjects (25 boys, 19 girls) were selected as a control group. The range of post-exercise GH peak was very wide, but medians were not statistically different in cases and controls (p=0.570). Multivariate analysis showed that post-exercise GH peak was not related to age (p=0.743), gender (p=0.296) or pubertal status (p=0.440) in both groups. GH increase from baseline showed the same behavior (p=0.265, 0.639 and 0.105, respectively). In CAH patients, GH peak and GH increase were both directly related to 17-OH-progesterone levels [GH peak: p=0.032--95% confidence interval (CI): 0.01-0.34--beta=0.18; GH increase: p=0.008--95% CI: 0.06-0.35--beta=0.20]. The negative effect of glucocorticoid therapy on GH secretion seems to be dominant in CAH. The most effective approach to adjust treatment remains monitoring growth. Relying on hormonal markers to adequate steroid therapy may result in over-treatment, GH suppression, and finally poor linear growth.

Prevention of congenital rubella and congenital varicella in Europe.

Despite the availability of safe and efficacious vaccines, cases of congenital rubella and varicella syndrome still occur in Europe. As of 2004, several countries had high proportions of women of childbearing age that were susceptible to rubella and varicella virus infection.

Herpes Virus Infections During Treatment With Etanercept in Juvenile Idiopathic Arthritis.

Incidence rates for varicella and herpes zoster were similar in patients with juvenile idiopathic arthritis receiving etanercept/methotrexate (n = 85, 184.9 patient-years [PY]) or methotrexate alone (n = 71, 199.4 PY); no complicated varicella or herpes zoster cases were reported; herpes labialis incidence was higher in patients receiving etanercept/methotrexate versus methotrexate alone (0.38 vs. 0.24 PY).

Willingness of Patients with Breast Cancer in the Adjuvant and Metastatic Setting to Use Electronic Surveys (ePRO) Depends on Sociodemographic Factors, Health-related Quality of Life, Disease Status and Computer Skills.

Introduction: Because of the often unfavorable prognosis, particularly for patients with metastases, health-related quality of life is extremely important for breast cancer patients. In recent years, data on patient-relevant endpoints is being increasingly collected electronically; however, knowledge on the acceptance and practicability of, and barriers to, this form of data collection remains limited. Material and Methods: A questionnaire was completed by 96 patients to determine to what extent existing computer skills, disease status, health-related quality of life and sociodemographic factors affect patients' potential willingness to use electronics methods of data collection (ePRO). Results: 52 of 96 (55 %) patients reported a priori that they could envisage using ePRO. Patients who a priori preferred a paper-based survey (pPRO) tended to be older (ePRO 53 years vs. pPRO 62 years; p = 0.0014) and typically had lower levels of education (p = 0.0002), were in poorer health (p = 0.0327) and had fewer computer skills (p = 0.0003). Conclusion: Barriers to the prospective use of ePRO were identified in older patients and patients with a lower quality of life. Given the appropriate conditions with regard to age, education and current health status, opportunities to participate should be provided to encourage patients' willingness to take part and ensure the validity of survey results. Focusing on ease of use of ePRO applications and making applications more patient-oriented and straightforward appears to be the way forward.

Short antibiotic prophylaxis for bacterial infections in a neonatal intensive care unit: a randomized controlled trial.

We compared the effectiveness of a single dose and a three-day course of antibiotic prophylaxis in preventing bacterial infections in high-risk neonates. The study was a prospective, randomized controlled trial conducted in a 20-bed tertiary referral neonatal intensive care unit (NICU). A series of 130 neonates admitted consecutively to the NICU, fulfilling risk factors for infection, were assigned at random to receive intravenous antibiotic prophylaxis with ampicillin and netilmicin either in two daily doses for 72 h (three-day-administration group, 67 infants) or in a single bolus injection on admission (bolus group, 63 infants). Hospital-acquired infection, the main outcome measure, was defined as infection that developed at least 48 h after admission, and vertical infection (maternally transmitted) was considered to be present when clinical symptoms and abnormal laboratory findings became evident within 48 h of birth. Infections were considered as suspected when clinical and laboratory findings of infection were present, without positive cultures, and as confirmed when positive cultures were also present. No significant differences were found between the two groups of neonates studied in mean birth weight, gestational age or postnatal age on admission. The incidence of vertical infection was similar in the two groups (16/67, 23.9% vs. 14/63, 22.2%). Of the 130 newborns studied, 29 (22.3%) acquired at least one nosocomial infection during their NICU stay; total hospital-acquired infections, calculated as the incidence density of infection (the number of infective episodes divided by the number of days in the NICU), were less frequent among newborns who received the three-day course than the bolus (relative risk 0.69). This difference, although not statistically significant, depended on the different incidence density of confirmed nosocomial infections rather than on suspected infections (relative risk 0.59; 95% confidence interval 0.32-1.09; P=0.1). There were no significant differences between the two groups in overall mortality. A single bolus administration on admission is therefore likely to be as effective as a three-day course of antibiotic prophylaxis in preventing bacterial infection in high-risk infants admitted to an NICU.

Size at birth by gestational age and hospital mortality in very preterm infants: results of the area-based ACTION project.

BACKGROUND: Size at birth is an important predictor of neonatal outcomes, but there are inconsistencies on the definitions and optimal cut-offs. AIMS: The aim of this study is to compute birth size percentiles for Italian very preterm singleton infants and assess relationship with hospital mortality. STUDY DESIGN: Prospective area-based cohort study. SUBJECTS: All singleton Italian infants with gestational age 22-31 weeks admitted to neonatal care in 6 Italian regions (Friuli Venezia-Giulia, Lombardia, Marche, Tuscany, Lazio and Calabria) (n. 1605). OUTCOME MEASURE: Hospital mortality. METHODS: Anthropometric reference charts were derived, separately for males and females, using the lambda (λ) mu (µ) and sigma (σ) method (LMS). Logistic regression analysis was used to estimate mortality rates by gestational age and birth weight centile class, adjusting for sex, congenital anomalies and region. RESULTS: At any gestational age, mortality decreased as birth weight centile increased, with lowest values observed between the 50th and the 89th centiles interval. Using the 75th-89th centile class as reference, adjusted mortality odds ratios were 7.94 (95% CI 4.18-15.08) below 10th centile; 3.04 (95% CI 1.63-5.65) between the 10th and 24th; 1.96 (95% CI 1.07-3.62) between the 25th and the 49th; 1.25 (95% CI 0.68-2.30) between the 50(h) and the 74th; and 2.07 (95% CI 1.01-4.25) at the 90th and above. CONCLUSIONS: Compared to the reference, we found significantly increasing adjusted risk of death up to the 49th centile, challenging the usual 10th centile criterion as risk indicator. Continuous measures such as the birthweight z-score may be more appropriate to explore the relationship between growth retardation and adverse perinatal outcomes.

Back-calculation by birth cohort, incorporating age- specific disease progression, pre-AIDS mortality and change in European AIDS case definition. European Union Concerted Action on Multinational AIDS Scenarios.

OBJECTIVES: To adapt and improve methodology for back-calculation of AIDS in Europe and to examine the feasibility of estimating past HIV incidence by birth cohort. METHODS: Empirical Bayesian back-calculation (EBBC) used Markov disease progression models, modified to allow for three diseases added to the AIDS case definition in 1993 and for pre-AIDS mortality, and estimation by penalized maximum likelihood with a neighbour prior. EBBC by 5-year birth cohort assumed a minimum age at infection and age-dependent progression rates; three versions, with varying age effects, were investigated using AIDS cases diagnosed prior to the introduction of highly active antiretroviral therapies (HAART). RESULTS: Compared with the no age-effect version, EBBC by birth cohort tended to produce flattened HIV incidence curves in country-exposure groups with < 1000 AIDS cases, reflecting effects of the neighbour prior when data become sparse. Otherwise, birth cohort analysis, with moderate effects of age on progression, gave initially increasing incidence curves and consistent patterns across countries, with the 1960-1964 cohort most affected. In the European Union, incidence is estimated to have peaked in 1983 among homosexual men and in 1988 among injecting drug users; 460000 persons were estimated to be living with HIV/AIDS at the end of 1995. CONCLUSIONS: Our improved methodology deals effectively with the change in AIDS case definition and has allowed quantitative assessments of the HIV epidemic by birth cohort using all AIDS cases diagnosed before 1996, thus providing a sound basis for public health policy at a time when estimation of more recent prevalence is compromised by the effects of HAART.

Anatomic distribution of the growth-associated protein GAP-43 in the developing human brainstem.

GAP-43 is a membrane phosphoprotein whose expression is high in neurons undergoing development or remodeling of axonal connections. This study used a monospecific antibody to GAP-43 to investigate the sequences of fiber tract elongation and synaptic development in the human brainstem. Immunocytochemistry was performed in 14 fetal and infant brainstems; two child and adult cases were also examined for comparison. At midgestation, GAP-43 immunostaining was moderately intense across nuclei and fiber tracts, except for the corticospinal tract, where levels were higher, and cranial nerve nucleus VII, superior olive, inferior colliculus, inferior olivary hilum, inferior cerebellar peduncle, medial lemniscus, and medial longitudinal fasciculus, where staining was nearly absent. By the end of the neonatal period, the relative distribution of GAP-43 immunostaining appeared well-established and similar, although not identical, to that in the child and adult brainstem. Immunostaining was absent or negligible in almost all the cranial nerve somato- and branchiomotor nuclei, auditory-relay nuclei, and vestibular nuclei, while remaining intense in visceral-related nuclei, reticular formation, cochlear nucleus, and periaqueductal gray. Staining was also virtually absent in all fiber tracts at birth, except for the corticospinal tract and central tegmental tract. Persistence of GAP-43 staining in the corticospinal tract past the fetal period suggests that this tract remains in a plastic state beyond initial axonal elongation. Intense immunostaining in visceral-related nuclei into adulthood suggests that these regions may continue to undergo synaptic reorganization. This study provides baseline information relevant to understanding developmental brainstem disorders in early human life.

Decreased serotonergic receptor binding in rhombic lip-derived regions of the medulla oblongata in the sudden infant death syndrome.

The sudden infant death syndrome (SIDS) is postulated to result from a failure of homeostatic responses to life-threatening challenges (e.g. asphyxia, hypercapnia) during sleep. The ventral medulla participates in sleep-related homeostatic responses, including chemoreception, arousal, airway reflex control, thermoregulation, respiratory drive, and blood pressure regulation, in part via serotonin and its receptors. The ventral medulla in humans contains the arcuate nucleus, in which we have shown isolated defects in muscarinic and kainate receptor binding in SIDS victims. We also have demonstrated that the arcuate nucleus is anatomically linked to the nucleus raphé obscurus, a medullary region with serotonergic neurons. We tested the hypothesis that serotonergic receptor binding is decreased in both the arcuate nucleus and nucleus raphé obscurus in SIDS victims. Using quantitative autoradiography, 3H-lysergic acid diethylamide (3H-LSD binding) to serotonergic receptors (5-HT1A-D and 5-HT2 subtypes) was measured blinded in 19 brainstem nuclei. Cases were classified as SIDS (n = 52), acute controls (infants who died suddenly and in whom a complete autopsy established a cause of death) (n = 15), or chronic cases with oxygenation disorders (n = 17). Serotonergic binding was significantly lowered in the SIDS victims compared with controls in the arcuate nucleus (SIDS, 6 +/- 1 fmol/mg tissue; acutes, 19 +/- 1; and chronics, 16 +/- 1; p = 0.0001) and n. raphé obscurus (SIDS, 28 +/- 3 fmol/mg tissue; acutes, 66 +/- 6; and chronics, 59 +/- 1; p = 0.0001). Binding, however, was also significantly lower (p < 0.05) in 4 other regions that are integral parts of the medullary raphé/serotonergic system, and/or are derived, like the arcuate nucleus and nucleus raphé obscurus, from the same embryonic anlage (rhombic lip). These data suggest that a larger neuronal network than the arcuate nucleus alone is involved in the pathogenesis of SIDS, that is, a network composed of inter-related serotonergic nuclei of the ventral medulla that are involved in homeostatic mechanisms, and/or are derived from a common embryonic anlage.

Decreased kainate receptor binding in the arcuate nucleus of the sudden infant death syndrome.

The human arcuate nucleus is postulated to be homologous to ventral medullary surface cells in animals that participate in ventilatory and blood pressure responses to hypercarbia and asphyxia. Recently, we reported a significant decrease in muscarinic cholinergic receptor binding in the arcuate nucleus in victims of the sudden infant death syndrome compared with control patients that died of acute causes. To test the specificity of the deficit to muscarinic cholinergic binding, we examined kainate binding in the arcuate nucleus in the same database. We assessed 3H-kainate binding to kainate receptors with tissue receptor autoradiography in 17 brainstem nuclei. Analysis of covariance was used to examine differences in binding by diagnosis, adjusted for postconceptional age (the covariate). Cases were classified as SIDS, 47; acute control, 15; and chronic group with oxygenation disorder, 17. (Acute controls are infants who died suddenly and unexpectedly and in whom a complete autopsy established a cause of death). The arcuate nucleus was the only region in which there was a significant difference in the age-adjusted mean kainate binding between the SIDS group (37+/-2 fmol/mg tissue) and both the acute controls (77+/-4 fmol/mg tissue) (p < 0.0001) and the chronic group (69+/-4 fmol/mg tissue) (p < 0.0001). There was a positive correlation between the density of muscarinic cholinergic and kainate binding in the SIDS cases only (R = 0.460; p = 0.003). The neurotransmitter deficit in the arcuate nucleus in SIDS victims involves more than one receptor type relevant to carbon dioxide and blood pressure responses at the ventral medullary surface.

Three-dimensional distribution of [3H]quinuclidinyl benzilate binding to muscarinic cholinergic receptors in the developing human brainstem.

Acetylcholine has been implicated in brainstem mechanisms of cardiac and ventilatory control, arousal, rapid eye movement (REM) sleep, and cranial nerve motor activity. Virtually nothing is known about the developmental profiles of cholinergic perikarya, fibers, terminals, and/or receptors in the brainstems of human fetuses and infants. This study provides baseline information about the quantitative distribution of muscarinic cholinergic receptors in fetal and infant brainstems. Brainstem sections were analyzed from 6 fetuses (median age: 21.5 postconceptional weeks), 4 premature infants (median age: 26 postconceptional weeks), and 11 infants (median age: 53 postconceptional weeks). One child and three adult brainstems were examined as indices of maturity for comparison. The postmortem interval in all cases was less than or equal to 24 hours (median: 10 hours). Muscarinic receptors were localized by autoradiographic methods with the radiolabeled antagonist [3H]quinuclidinyl benzilate ([3H]QNB). Computer-based methods permitted quantitation of [3H]QNB binding in specific nuclei and three-dimensional reconstructions of binding patterns. By midgestation, muscarinic cholinergic receptor binding is already present and regionally distributed, with the highest binding levels in the interpeduncular nucleus, inferior colliculus, griseum pontis, nucleus of the solitary tract, motor cranial nerve nuclei, and reticular formation. During the last half of gestation, [3H]QNB binding decreases in most, but not all of the nuclei sampled. The most substantial decline occurs in the reticular formation of the medulla and pons, a change that is not fully explained by progressive myelination and lipid quenching. Binding levels remain essentially constant in the inferior olive and griseum pontis. Around the time of birth or shortly thereafter, the relative distribution of binding becomes similar to that in the adult, with the highest levels in the interpeduncular nucleus and griseum pontis, although binding levels are higher overall in the infant. In the rostral pontine reticular formation, paramedian bands of high muscarinic binding are present which do not correspond to a cytoarchitectonically defined nucleus. By analogy to animal studies, these bands may comprise a major cholinoreceptive region of the human rostral pontine reticular formation involved in REM sleep. In the human interpeduncular nucleus in all age periods examined, muscarinic binding localizes to the lateral portions bilaterally, indicative of a heterogeneous chemoarchitecture. Muscarinic binding is high in the arcuate nucleus, a component of the putative respiratory chemosensitive fields along the ventral surface of the infant medulla. This observation is consistent with the known effects of muscarinic agents on chemosensitivity and ventilatory responses applied to the ventral medullary surface in animal models. The nonuniform distribution of muscarinic binding in the caudorostral plane in individual brainstem nuclei, as illustrated by three-dimensional reconstructions, underscores the need for rigorous sampling at precisely matched levels in quantitative studies. This study provides basic information toward understanding the neurochemical basis of brainstem disorders involving dysfunction of autonomic and ventilatory control, arousal, and REM sleep in preterm and full-term newborns and infants and for developing cholinergic drugs for such disorders in the pediatric population.

Developmental changes in heterogeneous patterns of neurotransmitter receptor binding in the human interpeduncular nucleus.

The interpeduncular nucleus (IPN) exhibits many complex features, including multiple subnuclei, widespread projections with the forebrain and brainstem, and neurotransmitter heterogeneity. Despite the putative importance of this nucleus, very little is known about its neurochemical development in the human. The human IPN is cytoarchitectonically simple, unlike the rat IPN, which displays considerable heterogeneity. In the following study, we hypothesized that the developing human IPN is neurochemically heterogeneous despite its cytological simplicity. The chemoarchitecture in this study was defined by neurotransmitter receptor binding patterns by using quantitative tissue autoradiography for the muscarinic, nicotinic, serotoninergic, opioid, and kainate receptors. We examined neurotransmitter receptor binding in the developing human IPN in a total of 15 cases. The midbrains of five midgestational fetuses (19-26 gestational weeks) and six infants (38-74 postconceptional weeks) were examined. The midbrain of one child (4 years) and three adults (20-68 years) were analyzed as indices of maturity. At all ages examined, high muscarinic binding was localized to the lateral subdivision of the IPN, high serotoninergic binding was localized to the dorsal IPN, and high opioid receptor binding was localized to the medial IPN. The developmental profile was unique for each radioligand. We report a heterogenous distribution of neurotransmitter receptor binding in the developing human IPN, which supports a complex role for it in human brain function.