bluuebunny/crossref_metadata_2025 huggingface dataset:
Operant Conditioning of Gill Withdrawal inAplysia
Authors: Hawkins Robert D. , Clark Gregory A. , Kandel Eric R.
Published: March 2006

A basic question in neuroscience is how different forms of learning are related. To further address that question, we examined whether gill withdrawal inAplysia, which has already been studied extensively for neuronal mechanisms contributing to habituation, sensitization, and classical conditioning, also undergoes operant conditioning. Animals were run in pairs. During the initial training period, the contingent (experimental) animal received a siphon shock each time its gill relaxed below a criterion level, and the yoked control animal received a shock whenever the experimental animal did, regardless of its own gill position. This was followed by an extinction period when there was no shock, a retraining period when both animals were contingent, and another extinction period. The experimental animals spent more time with their gills contracted above the criterion level than did the control animals during each period, demonstrating operant conditioning. The type of gill behavior modified by learning shifted over time: the experimental animals had a larger increase in the frequency and duration of spontaneous contractions than did the control animals during the first but not the last extinction period and a larger increase in the level of tonic contraction during the last but not the first extinction period. Because many of the neurons controlling spontaneous and tonic gill withdrawal have already been identified, it should now be possible to examine the cellular locus and mechanism of operant conditioning and compare them with those for other forms of learning of the same behavior.
Neuronal Basis of the Slow (<1 Hz) Oscillation in Neurons of the Nucleus Reticularis ThalamiIn Vitro
Authors: Blethyn Kate L. , Hughes Stuart W. , Tóth Tibor I. , Cope David W. , Crunelli Vincenzo
Published: March 2006

During deep sleep and anesthesia, the EEG of humans and animals exhibits a distinctive slow (<1 Hz) rhythm. In inhibitory neurons of the nucleus reticularis thalami (NRT), this rhythm is reflected as a slow (<1 Hz) oscillation of the membrane potential comprising stereotypical, recurring “up” and “down” states. Here we show that reducing the leak current through the activation of group I metabotropic glutamate receptors (mGluRs) with eithertrans-ACPD [(+/−)-1-aminocyclopentane-trans-1,3-dicarboxylic acid] (50–100 μm) or DHPG [(S)-3,5-dihydroxyphenylglycine] (100 μm) instates an intrinsic slow oscillation in NRT neuronsin vitrothat is qualitatively equivalent to that observedin vivo. A slow oscillation could also be evoked by synaptically activating mGluRs on NRT neurons via the tetanic stimulation of corticothalamic fibers. Through a combination of experiments and computational modeling we show that the up state of the slow oscillation is predominantly generated by the “window” component of the T-type Ca2+current, with an additional supportive role for a Ca2+-activated nonselective cation current. The slow oscillation is also fundamentally reliant on anIhcurrent and is extensively shaped by both Ca2+- and Na+-activated K+currents. In combination with previous work in thalamocortical neurons, this study suggests that the thalamus plays an important and active role in shaping the slow (<1 Hz) rhythm during deep sleep.
Fragile X Mental Retardation Protein Shifts between Polyribosomes and Stress Granules after Neuronal Injury by Arsenite Stress orIn VivoHippocampal Electrode Insertion
Authors: Kim Soong Ho , Dong Willie K. , Weiler Ivan Jeanne , Greenough William T.
Published: March 2006

Fragile X mental retardation protein (FMRP), the lack of which causes fragile X syndrome, is an RNA-binding protein encoded by theFMR1gene. FMRP accompanies mRNAs from the nucleus to dendritic regions and is thought to regulate their translation at synapses. It has been shown that FMRP moves into nontranslating stress granules (SGs) during heat stress of cultured fibroblasts (Mazroui et al., 2002). We used a novel method to isolate SGs from neurons by virtue of their TIA-1 (T-cell intracellular antigen 1) protein component, and found that FMRP moved out of polyribosomes and into SGs subsequent to oxidative stress. We then examined FMRP changes in subcellular localization resulting from mechanically induced neuronal injury by placement of electrodes into the dentate gyrus and the perforant path of the hippocampusin vivo. During the first 10 min after electrode insertion into one hippocampus, FMRP shifted into SGs and away from polyribosomes, in both hippocampi. Although the injury discharge subsided beyond 10 s, FMRP levels in polyribosomes and stress granules did not return to basal levels until 30 min after electrode penetration. Our findings suggest that procedures forin vivoinduction of long-term potentiation or long-term depression should incorporate a 30 min rest period after electrode insertion, and indicate that the contralateral hippocampus cannot be considered an unstimulated control tissue.
A Role for the Periaqueductal Gray in Switching Adaptive Behavioral Responses
Authors: Sukikara M. H. , Mota-Ortiz S. R. , Baldo M. V. , Felício L. F. , Canteras N. S.
Published: March 2006

Previous studies suggested a role for the rostral lateral periaqueductal gray (PAG) in the inhibition of maternal behavior induced by low doses of morphine in dams with previous morphine experience. In the present study, we first showed that unilateral NMDA lesions placed in this particular PAG region prevented the morphine-induced inhibition of maternal behavior in previously morphine-sensitized dams. As suggested by previous Fos data on the PAG, predatory hunting appears as a likely candidate to replace maternal behavior in the morphine-treated dams. By testing saline- and morphine-treated dams with live cockroaches only, we have presently shown that morphine challenge increased insect hunting. Moreover, morphine- and saline-treated dams were also observed in an environment containing pups and roaches. Although most of the saline-treated animals displayed active nursing and only occasionally presented insect hunting, all of the morphine-treated animals ignored the pups and avidly pursued and caught the roaches. We next questioned whether the rostral lateral PAG would be involved in this behavioral switch. Our results showed that unilateral lesions of the rostral lateral PAG, but not other parts of the PAG, partially impaired predatory hunting and restored part of the maternal response. Moreover, bilateral lesions of the rostral lateral PAG produced even more dramatic effects in inhibiting insect hunting and restoring maternal behavior. The present findings indisputably show that the rostral lateral PAG influences switching from maternal to hunting behavior in morphine-treated dams, thus supporting a previously unsuspected role for the PAG in selecting adaptive behavioral responses.
Dissociable Roles for the Nucleus Accumbens Core and Shell in Regulating Set Shifting
Authors: Floresco Stan B. , Ghods-Sharifi Sarvin , Vexelman Claudia , Magyar Orsolya
Published: March 2006

The ability to behave in a flexible manner is an executive function mediated in part by different regions of the prefrontal cortex. The present study investigated the role of two major efferents of the prefrontal cortex, the nucleus accumbens (NAc) core and shell, in behavioral flexibility using a maze-based strategy set-shifting task. During initial discrimination training, rats learned to use either an egocentric response or a visual-cue discrimination strategy to obtain food reward. During the set shift, animals had to shift from the previously acquired response or visual-cue-based strategy and learn the alternate discrimination. Inactivation of the NAc core, induced by infusion of the GABA agonists baclofen and muscimol, did not impair initial acquisition of either a response or visual-cue discrimination but severely disrupted shifting from one strategy to another. Analysis of the type of errors revealed that impairments in set shifting were not attributable to increased perseveration but to a disruption of the acquisition and maintenance of a new strategy. In contrast, inactivation of the NAc shell did not impair acquisition of either a response or a visual-cue discrimination, or shifting from one strategy to another. However, inactivation of the NAc shell before initial discrimination training improved performance during the set shift relative to control animals. These data indicate that the NAc core and shell make dissociable contributions to behavioral flexibility during set shifting. The NAc core facilitates the acquisition and maintenance of novel behavioral strategies and elimination of inappropriate response options, whereas the shell may mediate learning about irrelevant stimuli.
Cortical and Subcortical Contributions to Stop Signal Response Inhibition: Role of the Subthalamic Nucleus
Authors: Aron Adam R. , Poldrack Russell A.
Published: March 2006

Suppressing an already initiated manual response depends critically on the right inferior frontal cortex (IFC), yet it is unclear how this inhibitory function is implemented in the motor system. It has been suggested that the subthalamic nucleus (STN), which is a part of the basal ganglia, may play a role because it is well placed to suppress the “direct” fronto-striatal pathway that is activated by response initiation. In two experiments, we investigated this hypothesis with functional magnetic resonance imaging and a Stop-signal task. Subjects responded to Go signals and attempted to inhibit the initiated response to occasional Stop signals. In experiment 1, Going significantly activated frontal, striatal, pallidal, and motor cortical regions, consistent with the direct pathway, whereas Stopping significantly activated right IFC and STN. In addition, Stopping-related activation was significantly greater for fast inhibitors than slow ones in both IFC and STN, and activity in these regions was correlated across subjects. In experiment 2, high-resolution functional and structural imaging confirmed the location of Stopping activation within the vicinity of the STN. We propose that the role of the STN is to suppress thalamocortical output, thereby blocking Go response execution. These results provide convergent data for a role for the STN in Stop-signal response inhibition. They also suggest that the speed of Go and Stop processes could relate to the relative activation of different neural pathways. Future research is required to establish whether Stop-signal inhibition could be implemented via a direct functional neuroanatomic projection between IFC and STN (a “hyperdirect” pathway).
Amygdala Activity Is Associated with the Successful Encoding of Item, But Not Source, Information for Positive and Negative Stimuli
Authors: Kensinger Elizabeth A. , Schacter Daniel L.
Published: March 2006

It has been debated whether the link between amygdala activity and subsequent memory is equally strong for positive and negative information. Moreover, it has been unclear whether amygdala activity at encoding corresponds with enhanced memory for all contextual aspects of the presentation of an emotional item, or whether amygdala activity primarily enhances memory for the emotional item itself. In the present functional magnetic resonance imaging study, participants encoded positive and negative stimuli while performing one of two tasks (judgment of animacy or commonness). Amygdala activity at encoding was related to subsequent memory for the positive and negative items but not to subsequent memory for the task performed. Amygdala activity showed no relationship to subsequent-memory performance for the neutral items. Regardless of the emotional content of the items, activity in the entorhinal cortex corresponded with subsequent memory for the item but not with memory for the task performed, whereas hippocampal activity corresponded with subsequent memory for the task performed. These results are the first to demonstrate that the amygdala can be equally engaged during the successful encoding of positive and negative items but that its activity does not facilitate the encoding of all contextual elements present during an encoding episode. The results further suggest that dissociations within the medial temporal lobe sometimes noted for nonemotional information (i.e., activity in the hippocampus proper leading to later memory for context, and activity in the entorhinal cortex leading to later memory for an item but not its context) also hold for emotional information.
Protein Kinase A Regulates the Sensitivity of Spinal Commissural Axon Turning to Netrin-1 But Does Not Switch between Chemoattraction and Chemorepulsion
Authors: Moore Simon W. , Kennedy Timothy E.
Published: March 2006

Bifunctional axon guidance cues have been grouped into two classes depending on whether changes in intracellular cAMP or cGMP switch the response of the growth cone between attraction and repulsion. According to this model, axons respond to netrin-1, a group I guidance cue, as a chemoattractant when cAMP levels are high in the growth cone but switch and are repelled when the intraneuronal concentration of cAMP is low. The model is complicated by the proposal that cAMP-dependent kinase, protein kinase A (PKA), functions as a downstream effector for several guidance cues, including netrin-1, suggesting a close inter-relationship between guidance cue signal transduction and mechanisms regulating the switch between attraction and repulsion. Here, we examine possible interactions between netrin-1-mediated axon guidance and cAMP signaling in embryonic rat spinal commissural neurons. We report that netrin-1 does not alter the concentration of cAMP or PKA activity in these neurons across a wide range of netrin-1 concentrations and time points after application, leading us to conclude that netrin-1 does not regulate PKA in these cells. In contrast to the cyclic nucleotide switch model, we report that, despite inhibiting PKA, embryonic spinal commissural axons were always attracted to netrin-1 and never repelled. Instead, manipulating PKA regulated the sensitivity of chemoattraction to netrin-1: PKA inhibition reduced, and PKA activation increased, the distance over which axons turn toward a source of netrin-1. These findings indicate that the mechanisms underlying cyclic nucleotide-regulated switching are separable from the signal transduction mechanisms required for chemoattraction to netrin-1.
The Oyster's French Revolution: Testing a Nation's Reaction to a Lab-Produced Delicacy
Authors: merdji mohamed , debucquet gervaise , taylor andrew
Published: March 2006

The French produce 80 percent of Europe's oyster crop and eat almost one hundred thousand tons of the delicacy a year, but the country's love affair with this bivalve mollusk is being tested by a recent scientific development. By crossing a natural oyster with a laboratory-produced variety, scientists have created a sterile version known as a tetraploid. As a result, the new oyster does not reproduce which allows it to have the same taste and aspect all year round so defying the old adage that one should eat oysters only during the months that have an r in their names.

This break with tradition raises a host of questions concerning how consumers will react to such a development. Those who are against the new, year-round mollusk feel that it sacrifices the noble oyster on the altar of convenience foods while those in favour believe the development could breathe new life into a market that risks stagnating.

With this in mind, a research team from Audencia Nantes, one of France's top business schools, set out to gauge French oyster eaters' reaction to the tetraploid. Using an approach involving psychology, marketing, sociology, and anthropology, the researchers carried out in-depth individual interviews and group meetings based on tasting sessions which give an insight into what makes the oyster consumer tick.
““Pure”” Maple Syrup?
Authors: holmes matthew
Published: March 2006

This article examines the organic maple syrup industry in Canada, providing personal anecdote, a brief history of maple production and the underlying practice and philosophy of the organic movement as it applies to maple products. Often thought as inherently organic, modern, industrial maple syrup production includes a number of ways in which concerns may be raised for environment, sustainable farming practices or human health. Through interviews and research, the article presents some possible responses organic practices can make to such concerns, while also questioning whether organic maple production is everything it claims to be. The troubling and continued use of paraformaldehyde by the maple industry, though outlawed in both the U.S. and Canada, is raised, as are the accountability and inspection standards of regulatory bodies, both in conventional and organic maple production. The article concludes with the efforts at sustainability and diversity as practiced by an organic maple farm in New Brunswick and offers the author's personal views on the subject of sustainability and the merits of traditional methods of maple production.
Health, Neurologic, and Cognitive Status of HIV-Infected, Long-Surviving, and Antiretroviral-Naive Ugandan Children
Authors: Bagenda Danstan , Nassali Annette , Kalyesubula Israel , Sherman Becky , Drotar Dennis , Boivin Michael J. , Olness Karen
Published: March 2006

OBJECTIVE. The purpose of this study was to assess the health status and school-age neurodevelopmental progress of antiretroviral treatment (ARVT)–naive, HIV-infected Ugandan children who had been followed as part of cohorts of children born to HIV-infected and -noninfected mothers between 1989 and 1993.

METHODS. Twenty-eight children, aged 6 to 12 years, vertically infected with HIV-1 and never treated with ARVT were evaluated in terms of health status, neurologic, and psychometric testing. A randomly selected group of 42 seroreverters and 37 HIV-1 negative children who were age- and gender-matched and who had been followed in the same cohorts were evaluated also. The families studied were homogenous in their socioeconomic status. None of the mothers or children had received ARVT or been exposed to illicit drugs.

RESULTS. The HIV-infected children showed significantly more evidence of acute malnutrition. They also had more illness, especially parotitis, otitis media, upper respiratory infections, and lymphadenopathy. However, they did not differ significantly in neurologic and cognitive assessments when compared with age- and gender-matched seroreverter and HIV-negative children. They were in the normal range with respect to neurologic and psychometric development measures.

CONCLUSIONS.These children seem to represent a significant subgroup of HIV-infected child survivors for whom the progress of the disease is less aggressive throughout early life. Given the fact that many infants, especially in developing countries, continue to be born without the benefit of perinatal ARVT, there will likely continue to be many older HIV-infected children in the same situation as those described in this follow-up study. They will not have been recognized as being HIV-infected. It is important that such children be identified and offered access to ARVT and other appropriate support services.
Variation in the Diagnosis of Child Abuse in Severely Injured Infants
Authors: Trokel Matthew , Waddimba Anthony , Griffith John , Sege Robert
Published: March 2006

OBJECTIVE. Diagnosis of child abuse is difficult and may reflect patient, practitioner, and system factors. Previous studies have demonstrated potential lethal consequences if cases of abuse are missed and suggested a role for continuing medical education in improving the accuracy of diagnosis of suspected abuse. Although the majority of injured American children are treated at general hospitals, most published studies of severe injury resulting from child abuse have been conducted at children’s hospitals. The objective of this study was to evaluate the role of hospital type in observed variations in the frequency of diagnosis of child physical abuse among children with high-risk injuries.

METHODS. Hospital discharge data were evaluated, and adjusted rates of abuse diagnosis were reported according to hospital type. A regression model estimated the number of cases of abuse that would have been diagnosed if all hospitals identified abuse as frequently as observed at pediatric specialty hospitals. This study consisted of children who were <1 year old and admitted to US hospitals in 1997 for treatment of traumatic brain injury or femur fracture, excluding penetrating trauma or motor-vehicle–related injury. A total of 2253 weighted cases were analyzed.

RESULTS. The proportion of patients with a medical diagnosis of child abuse varied widely between hospital types: 29% of the cases were diagnosed as abuse at children’s hospitals compared with 13% at general hospitals. An estimated 178 infants (39% of total) with these specific injuries would have been identified as abused had they been treated at children’s rather than general hospitals.

CONCLUSIONS. Hospital type was associated with large variations in the frequency of diagnosis of child abuse. This variation was not related to observed differences in the patients or their injuries and may result from systematic underdiagnosis in general hospitals. This result has implications for quality-improvement programs at general hospitals, where the majority of injured children in the United States receive emergent medical care.
Cerebral Palsy Among Very Preterm Children in Relation to Gestational Age and Neonatal Ultrasound Abnormalities: The EPIPAGE Cohort Study
Authors: Ancel Pierre-Yves , Livinec Florence , Larroque Béatrice , Marret Stéphane , Arnaud Catherine , Pierrat Véronique , Dehan Michel , N′Guyen Sylvie , Escande Benoît , Burguet Antoine , Thiriez Gérard , Picaud Jean-Charles , André Monique , Bréart Gérard , Kaminski Monique ,   and the EPIPAGE Study Group
Published: March 2006

OBJECTIVE. To estimate the prevalence of cerebral palsy at 2 years of age among children born very preterm, according to gestational age, infant gender, plurality, and neonatal cranial ultrasound abnormalities.

METHODS. All infants born between 22 and 32 weeks of gestation in 9 regions of France in 1997 were included in this prospective, population-based, cohort study. The main outcome measure was cerebral palsy prevalence at 2 years. Of the 2364 survivors eligible for follow-up evaluation, 1954 (83%) were assessed at 2 years of age.

RESULTS. Among the 1954 children assessed at 2 years, 8.2% had cerebral palsy. Bilateral spastic cerebral palsy, hemiplegia, and monoplegia accounted for 72%, 9%, and 10% of cases, respectively. Fifty percent of the children with cerebral palsy walked independently at the age of 2, 31% were unable to walk but could sit independently, and 19% could not sit (unable to maintain head and trunk control). The prevalence of cerebral palsy was 20% at 24 to 26 weeks of gestation, compared with 4% at 32 weeks. On the basis of ultrasound findings in the neonatal period, we found that 17% of children with isolated grade III intraventricular hemorrhage and 25% of children with white matter damage (ie, ventricular dilation, persistent echodensities, or cystic periventricular leukomalacia) had cerebral palsy, compared with 4% of children with normal ultrasound scans.

CONCLUSIONS. Despite recent improvements in survival rates, cerebral palsy remains highly prevalent among very preterm children. Severe cranial ultrasound abnormalities predict motor disability strongly, but one third of infants with cerebral palsy had no ultrasound abnormalities.
Psychiatric Morbidity in Children With Medically Unexplained Chronic Pain: Diagnosis From the Pediatrician's Perspective
Authors: Konijnenberg Antoinette Y. , de Graeff-Meeder Elisabeth R. , van der Hoeven Joost , Kimpen Jan L. L. , Buitelaar Jan K. , Uiterwaal Cuno S.P.M. ,   and the Pain of Unknown Origin in Children Study Group
Published: March 2006

CONTEXT. There is very little general evidence to support the clinical management, particularly diagnosis, of medically unexplained chronic pain (UCP) in children.

OBJECTIVE. We sought to assess in children with UCP if clinical characteristics held important by general pediatricians help to accurately diagnose psychiatric morbidity and, alternatively, if the same can be achieved using dedicated questionnaires.

METHODS. We used a cross-sectional diagnostic study in a pediatric outpatient clinic of a university hospital. Our participants were 134 patients, aged 8 to 18 years, who were referred for UCP. Performed were (1) diagnostic test reflecting the pediatricians’ choice of clinical characteristics and (2) selected questionnaires. Classification was performed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, by a child psychiatrist using the Diagnostic Interview Schedule for Children-Parent Version IV and the Semi-structured Clinical Interview for Children and Adolescents. Results were analyzed by logistic regression.

RESULTS. Psychiatric morbidity was present in 80 of the children. A minority had a medical explanation for the pain (15% definite, 17% probable). The clinical diagnostic model included age, social-problem indicators, family structure, parental somatization, and school problems. In the quintile of children in whom this model predicted the highest risk, 93% indeed had psychiatric morbidity at reference testing. In the quintile with the lowest predicted risk, indeed only 27% had psychiatric morbidity. The Dutch Personality Inventory for Youth and the Child Behavior Checklist matched the pediatricians' choice of clinical characteristics. In the quintile of children with the highest predicted risk based on these questionnaires, 89% had psychiatric morbidity. In the quintile with the lowest predicted risk, only 15% had psychiatric morbidity.

CONCLUSIONS. A pediatrician-chosen set of clinical characteristics of children with UCP proves useful in diagnosing psychiatric morbidity. Using selected questionnaire screening yields similar results.
Local Anesthetic and Stylet Styles: Factors Associated With Resident Lumbar Puncture Success
Authors: Baxter Amy L. , Fisher Randall G. , Burke Bonnie L. , Goldblatt Sidney S. , Isaacman Daniel J. , Lawson M. Louise
Published: March 2006

OBJECTIVE. To assess the effects of procedural techniques, local anesthetic use, and postgraduate training level on lumbar puncture (LP) success rates.

METHODS. In this prospective observational study, medical students and residents (“trainees”) reported techniques used for infant LPs in an urban teaching emergency department. Data on postgraduate year, patient position, draping, total and trainee numbers of attempts, local anesthetic use, and timing of stylet removal were collected. Logistic regression analysis was used to identify predictors of successful LP, with success defined as the trainee obtaining cerebrospinal fluid with <1000 red blood cells per mm3.

RESULTS. We collected data on 428 (72%) of 594 infant LPs performed during the study period. Of 377 performed by trainees, 279 (74%) were successful. Local anesthesia was used for 280 (74%), and 225 (60%) were performed with early stylet removal. Controlling for the total number of attempts, LPs were 3 times more likely to be successful among infants >12 weeks of age than among younger infants (odds ratio [OR]: 3.1; 95% confidence interval [CI]: 1.2–8.5). Controlling for attempts and age, LPs performed with local anesthetic were twice as likely to be successful (OR: 2.2; 95% CI: 1.04–4.6). For infants ≤12 weeks of age, early stylet removal improved success rates (OR: 2.4; 95% CI: 1.1–5.2). Position, drape use, and year of training were not significant predictors of success.

CONCLUSIONS. Patient age, use of local anesthetic, and trainee stylet techniques were associated with LP success rates. This offers an additional rationale for pain control. Predictors identified in this study should be considered in the training of physicians, to maximize their success with this important procedure.
Dimensions of the Local Health Care Environment and Use of Care by Uninsured Children in Rural and Urban Areas
Authors: Gresenz Carole Roan , Rogowski Jeannette , Escarce José J.
Published: March 2006

OBJECTIVE. Despite concerted policy efforts, a sizeable percentage of children lack health insurance coverage. This article examines the impact of the health care safety net and health care market structure on the use of health care by uninsured children.

METHODS. We used the Medical Expenditure Panel Survey linked with data from multiple sources to analyze health care utilization among uninsured children. We ran analyses separately for children who lived in rural and urban areas and assessed the effects on utilization of the availability of safety net providers, safety net funding, supply of primary care physicians, health maintenance organization penetration, and the percentage of people who are uninsured, controlling for other factors that influence use.

RESULTS. Fewer than half of uninsured children had office-based visits to health care providers during the year, 8% of rural and 10% of urban children visited the emergency department at least once, and just over half of children had medical expenditures or charges during the year. Among uninsured children in rural areas, living closer to a safety net provider and living in an area with a higher supply of primary care physicians were positively associated with higher use and medical expenditures. In urban areas, the supply of primary care physicians and the level of safety net funding were positively associated with uninsured children's medical expenditures, whereas the percentage of the population that was uninsured was negatively associated with use of the emergency department.

CONCLUSIONS. Uninsured children had low levels of utilization over a range of different health care provider types and settings. The availability of safety net providers in the local area and the safety net's capacity to serve the uninsured influence access to care among children. Possible measures for ensuring access to health care among uninsured children include increasing the density of safety net providers in rural areas, enhancing funding for the safety net, and policies to increase primary care physician supply.
Prospective Evaluation of Postnatal Steroid Administration: A 1-Year Experience From the California Perinatal Quality Care Collaborative
Authors: Finer Neil N. , Powers Richard J. , Ou Chia-hao Simon , Durand David , Wirtschafter David , Gould Jeffrey B. ,   for the California Perinatal Quality Care Collaborative Executive Committee
Published: March 2006

OBJECTIVE. Postnatal steroids (PNSs) are used frequently to prevent or treat chronic lung disease (CLD) in the very low birth weight (VLBW) infant, and their use continues despite concerns regarding an increased incidence of longer-term neurodevelopmental abnormalities in such infants. More recently, there has been a suggestion that corticosteroids may be a useful alternative therapy for hypotension in VLBW infants, but there have been no prospective reports of such use for a current cohort of VLBW infants.

METHODS. The California Perinatal Quality Care Collaborative (CPQCC) requested members to supplement their routine Vermont Oxford Network data collection with additional information on any VLBW infant treated during their hospital course with PNS, for any indication. The indication, actual agent used, total initial daily dose, age at treatment, type of respiratory support, mean airway pressure, fraction of inspired oxygen, and duration of first dosing were recorded.

RESULTS. From April 2002 to March 2003 in California, 22 of the 62 CPQCC hospitals reported supplemental data, if applicable, from a cohort of 1401 VLBW infants (expanded data group [EDG]), representing 33.2% of the VLBW infants registered with the CPQCC during the 12-month period. PNSs for CLD were administered to 8.2% of all VLBW infants in 2003, 8.6% of infants in the 42 hospitals that did not submit supplemental data (routine data-set group, compared with 7.6% in EDG hospitals). Of the 1401 VLBW infants in the EDG, 19.3% received PNSs; 3.6% received PNSs for only CLD, 11.8% for only non-CLD indications, and 4.0% for both indications. At all birth weight categories, non-CLD use was significantly greater than CLD use. The most common non-CLD indication was hypotension, followed by extubation stridor, for which 36 (16.3%) infants were treated. For hypotension, medications used were hydrocortisone followed by dexamethasone. Infants treated with PNSs exclusively for hypotension had a significantly higher incidence of intraventricular hemorrhage, periventricular leukomalacia, and death when compared with infants treated only for CLD or those who did not receive PNSs.

CONCLUSIONS. The common early use of hydrocortisone for hypotension and the high morbidity and mortality in children receiving such treatment has not been recognized previously and prospective trials evaluating the short- and long-term risk/benefit of such treatment are urgently required.
Effects of Perinatal HIV Infection and Associated Risk Factors on Cognitive Development Among Young Children
Authors: Smith Renee , Malee Kathleen , Leighty Robert , Brouwers Pim , Mellins Claude , Hittelman Joan , Chase Cynthia , Blasini Ileana ,   for the Women and Infants Transmission Study Group
Published: March 2006

OBJECTIVE. We examined the effect of HIV, in combination with other important health and social factors, on the development of cognitive abilities of children perinatally exposed to HIV.

METHODS. Serial cognitive assessments were performed for 117 children who were infected vertically and 422 children who were exposed to but not infected with HIV, in a multicenter, natural history, longitudinal study. Repeated-measures analyses were used to evaluate the neurocognitive development of children between the ages of 3 and 7 years, as measured by the McCarthy Scales of Children’s Abilities (MSCA).

RESULTS. Children with HIV infection and class C status scored significantly lower in all domains of cognitive development, across all time points, than did those who were HIV infected without an AIDS-defining illness and those who were HIV exposed but not infected. There were no significant differences between the 2 latter groups in General Cognitive Index or specific domain scores. Rates of change in cognitive development were comparable (parallel) among all 3 groups over a period of 4 years. Factors that were associated consistently and significantly with lower mean scores were HIV status, number of times an examination had been completed previously, primary language, maternal education, and gender. No factors were related to rate of change of any mean domain score.

CONCLUSIONS. An early AIDS-defining illness increased the risk of chronic static encephalopathy during the preschool and early school age years. Children with HIV infection but no class C event performed as well as noninfected children in measures of general cognitive ability. No significantly different profiles of strengths and weaknesses for verbal, perceptual-performance, quantitative, or memory functioning were observed among children with or without HIV infection. A number of factors were found to have significant effects on the mean scores of children in all 3 groups; however, they were not related to the rate at which learning occurred.
Cumulative Effective Doses Delivered by Radiographs to Preterm Infants in a Neonatal Intensive Care Unit
Authors: Donadieu Jean , Zeghnoun Abdelkrim , Roudier Candice , Maccia Carlo , Pirard Phillipe , André Christine , Adamsbaum Catherine , Kalifa Gabriel , Legmann Paul , Jarreau Pierre-Henri
Published: March 2006

OBJECTIVE. We sought to determine the number and distribution of radiographs and the cumulative effective radiograph doses (cED) received by a population of preterm infants (PIs) hospitalized in an NICU.

STUDY DESIGN. We reviewed the files of all preterm infants (gestational age: <34 weeks) who were admitted to an NICU during an 18-month period and were discharged alive. A generalized additive model was used to study the relationship between cED and patient characteristics.

RESULTS. Four hundred fifty files were analyzed. The median gestational age was 30.1 weeks (range: 24.1–33.9 weeks), and the median birth weight was 1250 g (range: 520–2760 g). The median number of radiographs per infant was 10.6 (range: 0–95), and the median cED was 138 μSv (range: 0–1450 μSv). The cumulative dose exceeded 500 μSv in 7.6% of the cases. Factors that influenced the cumulative effective dose were gestational age, birth weight, care procedures, and clinical adverse events.

CONCLUSIONS. Given the potentially life-threatening complications of PIs, cumulative radiograph doses received in the ICU seem low with regard to environmental exposure and international recommendations. Additional studies are needed to evaluate the possible lifetime consequences of exposure to ionizing radiation at this age.
Diagnosis and Management of Pharyngitis in a Pediatric Population Based on Cost-Effectiveness and Projected Health Outcomes
Authors: Van Howe Robert S. , Kusnier Louis P.
Published: March 2006

BACKGROUND. Pharyngitis is a common childhood complaint. Current management for children and adolescents includes 1 of 6 strategies, ie, (1) observe without testing or treatment, (2) treat all suspected cases with an antibiotic, (3) treat those with positive throat cultures, (4) treat those with positive rapid tests, (5) treat those with positive rapid tests and those with positive throat cultures after negative rapid tests, or (6) use a clinical scoring measure to determine the diagnosis/treatment strategy. The sequelae of untreated group A hemolytic streptococcal (GAS) pharyngitis are rare, whereas antibiotic treatment may result in side effects ranging from rash to death. The cost-utility of these strategies for children has not been reported previously.

METHODS. A decision tree analysis incorporating the total cost and health impact of each management strategy was used to determine cost per quality-adjusted life-year ratios. Sensitivity analyses and Monte Carlo simulations assessed the accuracy of the estimates.

RESULTS. From a societal perspective with current Medicaid reimbursements for testing, performing a throat culture for all patients had the best cost-utility. For private insurance reimbursements, rapid antigen testing had the best cost-utility. Observing without testing or treatment had the lowest morbidity rate and highest cost from a societal perspective but the lowest cost from a payer perspective. The model was most sensitive to the incidence of acute rheumatic fever and peritonsillar abscess after untreated GAS pharyngitis. Monte Carlo simulations demonstrated considerable overlap among all of the options except for treating all patients and observing all patients.

CONCLUSIONS. Observing patients with pharyngitis had the lowest morbidity rate. The costs of this option were primarily from parental time lost from work. Before recommending observation rather than treatment of GAS pharyngitis, accurate estimates of the risk of developing acute rheumatic fever and peritonsillar abscess after GAS pharyngitis are needed.
Effect of Combined Pneumococcal Conjugate and Polysaccharide Vaccination on Recurrent Otitis Media With Effusion
Authors: van Heerbeek Niels , Straetemans Masja , Wiertsema Selma P. , Ingels Koen J.A.O. , Rijkers Ger T. , Schilder Anne G.M. , Sanders Elisabeth A.M. , Zielhuis Gerhard A.
Published: March 2006

BACKGROUND. Otitis media with effusion (OME) is very common during childhood. Because Streptococcus pneumoniae is one of the most common bacterial pathogens involved in OME, pneumococcal vaccines may have a role in the prevention of recurrent OME.

OBJECTIVE. We sought to assess the effect of combined pneumococcal conjugate and polysaccharide vaccinations on the recurrence of OME.

METHODS. A randomized, controlled trial was performed with 161 children, 2 to 8 years of age, with documented persistent bilateral OME. All subjects were treated with tympanostomy tubes (TTs). One half of the subjects were assigned randomly to additional vaccination with a 7-valent pneumococcal conjugate vaccine 3 to 4 weeks before and a 23-valent pneumococcal polysaccharide vaccine 3 months after tube insertion. Blood samples were drawn at the first vaccination, at the time of TT placement, and 1 and 3 months after the second vaccination. Levels of IgA and IgG serum antibody against the 7-valent pneumococcal conjugate vaccine serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F were measured with enzyme-linked immunosorbent assays. All children were monitored for recurrence of OME for 6 months after spontaneous extrusion of the TTs.

RESULTS. The overall recurrence rate of bilateral OME was 50%. Pneumococcal vaccinations induced significant 4.6- to 24.4-fold increases in the geometric means of all conjugate vaccine serotype antibody titers but did not affect recurrence of OME.

CONCLUSIONS. Combined pneumococcal conjugate and polysaccharide vaccination does not prevent recurrence of OME among children 2 to 8 years of age previously known to have persistent OME. Therefore, pneumococcal vaccines are not indicated for the treatment of children suffering from recurrent OME.
Does Clinical Presentation Explain Practice Variability in the Treatment of Febrile Infants?
Authors: Bergman David A. , Mayer Michelle L. , Pantell Robert H. , Finch Stacia A. , Wasserman Richard C.
Published: March 2006

BACKGROUND. Previous studies documented considerable variability in the treatment of febrile infants, despite the existence of practice guidelines for this condition. None of those studies documented the extent to which this variability is accounted for by differences in clinical severity.

OBJECTIVE. To quantify the individual effects of the patient's clinical presentation, demographic, provider, and practice characteristics, and regional variables on practice variability in the evaluation and treatment of febrile infants.

METHODS. With data collected through the Pediatric Research in Office Settings network, we analyzed data on the treatment of 2712 febrile infants examined by 484 pediatricians located in 194 practices. We analyzed hospitalization, lumbar puncture, urinalysis and/or urine culture, blood work, and initial antibiotic administration. We obtained a summary score for evaluation and treatment intensity (ranging from no tests or treatments to comprehensive testing, hospitalization, and antibiotic therapy) by performing principal-components analysis with these 5 variables. This summary score was regressed with respect to patients' clinical presentation, demographic and practice/practitioner features, and geographic region. Provider fixed effects were also included in the model.

RESULTS. Although the overall model explained 46.5% of the variance, the clinical characteristics of the patient alone explained 29.7% of the overall variance. Practice site fixed effects explained nearly 15% of the overall variance. Provider and practitioner characteristics and geographic region had minimal explanatory power.

CONCLUSIONS. Our results show that measures of the patient's clinical presentation account for nearly one third of the variability that our model explains. This suggests that differences in clinical presentation and severity of illness underlie much of the observed practice variability among pediatricians evaluating and treating febrile infants. These findings demonstrate that the management of this common and potentially serious condition depends more on the clinical presentation of the patient than on the characteristics of the provider/practice and the residential region.
Benefits and Costs ofChannel Onein a Middle School Setting and the Role of Media-Literacy Training
Authors: Austin Erica Weintraub , Chen Yi-Chun “Yvonnes” , Pinkleton Bruce E. , Johnson Jessie Quintero
Published: March 2006

OBJECTIVES. Channel One is a public-affairs program that includes 10 minutes of news and 2 minutes of paid product advertising or public service announcements. Advocates assert that it increases public-affairs knowledge, but critics charge that it garners a captive audience for teen-targeted advertising. This experiment analyzed the differential effects of Channel One depending on whether early-adolescent viewers received a media-literacy lesson in conjunction with viewing the program. Outcomes included perceptions of Channel One news programming, recall of program content and advertising, materialism, and political efficacy.

METHODS. Researchers used a posttest-only field experiment (N = 240) of seventh- and eighth-grade students using random assignment to conditions. Conditions included a control group, a group that received a fact-based lesson, and a group that received the same lesson content using a more emotive teaching style. It was expected that the emotion-added lesson condition would be more effective than the logic-only lesson condition because of its motivational component.

RESULTS. On average, students remembered more ads from Channel One than news stories. Participants in the control group remembered fewer news stories than did the groups that received the lessons. Students reported having purchased during the preceding 3 months an average of 2.5 items advertised on the program. Both fact-based and affect-added training increased student skepticism toward advertisers. As expected, student liking of the program enhanced their learning from it and was associated with higher levels of political efficacy. Students held misconceptions about the role of their school in the production of Channel One.

CONCLUSIONS. The use of Channel One by schools can have benefits, but these come with risk that some may consider unacceptable. On the positive side, student liking of the program was associated with their political efficacy. Although those who responded positively to program content and presentation style learned more from it, they also tended to want things that they saw in the advertisements. The data therefore show that the program can provide some benefits to young adolescents, but the results also provide justification for concerns about the commercialization of the classroom.
Difficulty in Recognizing Multiple Sulfatase Deficiency in an Infant
Authors: Santos Roberto P. , Hoo Joe J.
Published: March 2006

We describe the difficulty in recognizing multiple sulfatase deficiency (MSD; Online Mendelian Inheritance in Man [OMIM] database No. 272200) in an infant. MSD is a rare autosomal recessive disorder that affects the posttranslational activation of various sulfatase enzymes. It is both biochemically and clinically variable. Currently, there are 12 known sulfatases in humans, and the clinical presentation of MSD is a unique composite of those individual enzyme defects. Here we report a black girl who presented with bilateral broad thumbs and great toes, both with angulation deformities at birth. Rubinstein-Taybi syndrome (OMIM No. 180849) was considered initially. The detection of inclusion bodies in her white blood cells at 37 months of age led to the appropriate diagnostic workups for lysosomal storage diseases. Elevation of urine mucopolysaccharides provided additional clues, and the fibroblast enzyme assays finally established the diagnosis. Broad thumbs and great toes are rare features of MSD, and to the best of our knowledge such a bilateral congenital anomaly with angulation deformities has never been reported before to be associated with MSD.