Developmental characteristics and accuracy of autism screening among two-year-old toddlers in the ECHO program

BACKGROUND

The Modified Checklist for Autism in Toddlers (M-CHAT) is a common pediatric screening tool with mixed accuracy findings. Prior evidence supports M-CHAT screening for developmental concerns, especially in toddlers born preterm. This study examined M-CHAT accuracy in a large, nationwide sample.

METHODS

3393 participants from the Environmental influences on Child Health Outcomes (ECHO) program were included. Harmonized M-CHAT (M-CHAT-H) results were compared with parent-reported autism diagnosis and autism-related characteristics to assess accuracy for term and preterm children, together and separately. Generalized estimating equations, clustering for ECHO cohort and controlling for demographic covariates, were used to examine associations between developmental and behavioral characteristics with M-CHAT-H accuracy.

RESULTS

Sensitivity of the M-CHAT-H ranged from 36 to 60%; specificity ranged from 88 to 99%. Positive M-CHAT-H was associated with more developmental delays and behavior problems. Children with severe motor delays and more autism-related problems were more likely to have a false-negative M-CHAT-H. Children with fewer behavior problems and fewer autism-related concerns were more likely to have a false-positive screen.

CONCLUSION

The M-CHAT-H accurately detects children at low risk for autism and children at increased risk with moderate accuracy. These findings support use of the M-CHAT-H in assessing autism risk and developmental and behavioral concerns in children.

IMPACT

Previous literature regarding accuracy of the Modified Checklist for Autism in Toddlers (M-CHAT) is mixed but this study provides evidence that the M-CHAT performs well in detecting children at low risk for autism and consistently detects children with developmental delays and behavioral problems. The M-CHAT moderately detects children at increased risk for autism and remains a useful screening tool. This study examines M-CHAT accuracy in a large-scale, nationwide sample, examining associations between screening accuracy and developmental outcomes. These findings impact pediatric screening for autism, supporting continued use of the M-CHAT while further elucidating the factors associated with inaccurate screens.

Depressive Symptoms, Body Mass Index, and Physical Activity Self-Efficacy in African American Children

In recent decades, the prevalence of childhood depression and obesity has increased worldwide. African American (AA) children are more obese than White peers and experience many factors that can influence the onset of depressive symptoms. While depression and obesity have been examined in adolescents, there is a paucity of research in AA children. This study examined the relationships among depressive symptoms, obesity, and physical activity self-efficacy in AA children. A community sample of 65 AA children completed questionnaires for depressive symptoms and physical activity self-efficacy and also had body mass index (BMI) and BMI Z-scores calculated. Correlational statistics were used to examine associations between variables. Clinically significant total depression scores were present in 22% of children, while 48% were overweight or obese. Overall, children reported high physical activity self-efficacy. Higher depressive symptoms were associated with higher BMI Z-scores. Results also indicated significant correlations between the children's physical activity self-efficacy and depressive symptoms. Findings suggest that the associations between depressive symptoms, BMI, and physical activity self-efficacy in AA children merit additional examination. Early identification of depression in children may inform future approaches to treatment of psychological and physiological problems within the clinical setting. Screening for childhood depressive symptoms in primary care settings, especially those that specifically treat childhood obesity, can be instrumental in early identification of children with depression. Healthcare providers should be knowledgeable of the clinical presentation of depression and engaged in depression screening.

Socio-demographic, maternal, and child indicators of socioemotional problems in 2-year-old children: A cohort study

Throughout infancy and early childhood, stable and secure relationships with caregivers are needed to promote optimal socioemotional (SE) and cognitive development.The objective is to examine socio-demographic, maternal, and child indicators of SE problems in 2-year-olds living in an urban-suburban community in the southern United States.Mother-infant pairs enrolled in a prospective pregnancy cohort study.Shelby County (Memphis), Tennessee.One thousand five hundred three women were recruited during their second trimester and followed with their children through the child's age of 2 years.Child SE development was measured by the Brief Infant-Toddler Social Emotional Assessment at 2 years of age. Mothers reported their own behavioral and mental health, temperament, parenting stress, and potential for child abuse during gestation and/or when their child was 1 year of age. Examiners measured maternal IQ during data collection at the child's age of 1 year. Child communication, cognitive development, and risk for autism spectrum disorder were assessed at 1 and 2 years of age. Multivariable regression models were developed to predict mother-reported SE problems.In bivariate analyses, multiple maternal behavioral and mental health indicators and child cognitive skills were associated with reported child SE problems at 2 years of age. Regression analyses, controlling for socio-demographic, maternal, and child variables, showed the following factors were independently associated with mother-reported child SE problems: maternal education of high school or less, lower maternal IQ, higher maternal cyclothymic temperament score, greater parenting stress, greater maternal psychological distress, lower child expressive communication score, and child risk for autism spectrum disorder. Socio-demographic variables accounted for the variance often attributed to race.Since mothers in the study were medically low-risk, generalizing these findings to medically high-risk mothers is unwarranted. In addition, these SE outcomes in 2-year-old children do not reflect the trajectory of SE development throughout early childhood.Attention to independent indicators of future SE problems in children may help identify individual children and families needing intervention and target public prevention/treatment programs in communities.

Child rearing in the new independent states: a review of the literature

Child rearing in the New Independent States (NIS) is explored through a literature review examining child rearing practices in the former Union of Soviet Socialist Republics and the NIS. As exchanges between the NIS and other countries are underway, this information will help nurses understand issues faced by citizens of the NIS, families immigrating from the NIS, and health care professionals visiting the NIS. This review raises questions about NIS child rearing practices and may serve as a stimulus for further exploration of issues related to the health of children and families living in or emigrating from the NIS.

Guidelines for working with students having special health care needs

Students with special health care needs present challenges to persons involved with their education, but school staff are accepting the challenge to create safe, nurturing, and stimulating environments for these students. This article proposes guidelines for school staff working with students having special health care needs. The guidelines evolved from the authors' experiences and are child-related, family-related, and school-related. Discussion of each guideline includes illustrations of issues arising from them. Considerations for implementing the guidelines are presented and include discussion of school policies and procedures and state laws and regulations related to school staff working with students having special health care needs.

Facilitated transport of 6-mercaptopurine and 6-thioguanine and non-mediated permeation of 8-azaguanine in Novikoff rat hepatoma cells and relationship to intracellular phosphoribosylation

6-Mercaptopurine and 6-thioguanine strongly inhibited the zero-trans entry of hypoxanthine into Novikoff rat hepatoma cells which lacked hypoxanthine/guanine phosphoribosyltransferase, whereas 8-azaguanine had no significant effect. 6-Mercaptopurine was transported by the hypoxanthine carrier with about the same efficiency as its natural substrates (Michaelis-Menten constant = 372 +/- 23 microM; maximum velocity = 30 +/- 0.7 pmol/microl cell H2O per s). 8-Azaguanine entry into the cells, on the other hand, showed no sign of saturability and was not significantly affected by substrates of the hypoxanthine/guanine carrier. The rate of entry of 8-azaguanine at 10-100 microM amounted to only about 5% of that of hypoxanthine transport and was related to its lipid solubility in the same manner as observed for various substances whose permeation through the plasma membrane is believed to be non-mediated. Only the non-ionized form of 8-azaguanine (pKa = 6.6) permeated the cell membrane. Studies with wild type Novikoff cells showed that permeation into the cell was the main rate-determining step in the conversion of extracellular 8-azaguanine to intracellular aza-GTP and its incorporation into nucleic acids. In contrast, 6-mercaptopurine was rapidly transported into cells and phosphoribosylated; the main rate-determining step in its incorporation into nucleic acids was the further conversion of 6-mercaptopurine riboside 5'-monophosphate.

Hexose transport in Novikoff rat hepatoma cells. A simple carrier with directional symmetry, but variable relative mobilities of loaded and empty carrier

The kinetics of transport of the non-metabolizable hexose, 3-O-methyl-D-glucose, have been measured in Novikoff rat hepatoma cells by both zero-trans entry and equilibrium exchange procedures. Transport conformed to a simple carrier model which operates symmetrically with respect to direction, but with greater mobility of the loaded than of the empty carrier. Although a complete kinetic description of the transporter can, in theory, be obtained by application of integrated equations describing the time course of substrate equilibrium across the membrane beginning from the zero-trans situation, statistical analysis of hypothetical data indicated that directional asymmetry or differential mobilities of loaded and empty carrier cannot be discerned reliably from such data alone. The difference in mobility of loaded and empty carrier, apparent in a comparison of zero-trans entry and exchange data, ranged from 1.5--7-fold in different batches of cells. It is concluded that the magnitude of the difference is not an inherent property of the transporter, but is determined physiologically, and may be involved in regulation of hexose transport.

Deoxyglucose and 3-O-methylglucose transport in untreated and ATP-depleted Novikoff rat hepatoma cells. Analysis by a rapid kinetic technique, relationship to phosphorylation and effects of inhibitors

Detailed time courses of uptake of labeled 3-O-methyl-D-glucose and 2-deoxy-D-glycose by untreated and ATP-depleted Novikoff rat hepatoma cells were determined as function of concentration (0.2-10 mM) by a rapid mixing/sampling technique which allows uptake measurements in time intervals as short as 1.5 seconds. Intracellular accumulation of 3-O-methylglucose in untreated and ATP-depleted cells and of deoxyglucose in ATP-depleted cells to equilibrium followed pseudo-first order kinetics and initial velocities were computed from overall time courses of substrate accumulation. Initial velocity was a Michaelis-Menten function of exogenous substrate concentration. The estimated kinetic constants for zero-trans transport of 3-O-methylglucose were about the same for untreated and ATP-depleted cells (Kztm = 1.73 +/- 0.24 mM; Vztmax = 28.8 +/- 3.6 pmoles/microliter cell H2O. sec) and were similar to those for deoxyglucose transport in ATP-depleted cells (Kztm = 0.65 +/- 0.1 mM; Vztmax = 19.6 +/- 1.6 pmoles/microliter cell H2O. sec). Similar kinetic parameters were obtained for the transport of D-glucose and D-galactose in ATP-depleted cells. The transport of 3-O-methylglucose and deoxyglucose were inhibited by each other in a simple competitive manner with apparent Ki's similar to their transport Km's. In untreated cells, in which deoxyglucose was phosphorylated, intracellular steady-state levels of free deoxyglucose accumulated within 10 to 20 seconds of incubation regardless of its concentration in the medium. Thereafter, the rate of deoxyglucose incorporation into total cell material reflected the rate of phosphorylation rather than the transport rate. The rate of deoxyglucose transport exceeded the initial rate of its phosphorylation by 20-40 %. The intracellular steady-state-levels observed during the first 2 minutes of incubation decreased from about 40% of equilibrium level at 0.2 mM deoxyglucose to about 8% at 10 mM. Computer fits of a kinetic equation describing transport and phosphorylation as independent processes operating in tandem to these data are consistent with the observed kinetic constants for hexose transport and hexokinase activity with deoxyglucose as substrate. Upon longer incubation (2-10 minutes) the rate of deoxyglucose uptake by the phosphorylating cells decreased progressively, concomitant with a decrease in intracellular ATP and an increase in intracellular deoxyglucose to equilibrium levels. It is demonstrated that the rate of deoxyglucose uptake, measured at two or more minutes, seriously underestimates the hexose transport rate and yields misleading conclusions regarding the extent and type of inhibition by transport inhibitors, such as persantin or cytochalasin B. Persantin inhibited hexose transport in a simple non-competitive manner (Ki = 20 muM) indicating that the drug affects the function of the hexose carrier.

Mechanism of action of inosine dialdehyde (NSC 118994) in the inhibition of proliferation of tumor cells in culture

Inosine dialdehyde (INOX), the periodate oxidation product of inosine, inhibited the proliferation of various tumor cell lines in suspension culture in a concentration-dependent manner. A concentration of about 1 mM was required to completely inhibit the proliferation of Novikoff rat hepatoma and mouse L-cells, whereas about 0.1 mM completely inhibited the proliferation of L1210 and P388 mouse leukemia and Chinese hamster ovary cells. INOX inhibited in a similar time- and concentration-dependent manner the synthesis of protein, RNA, and DNA, as measured by the incorporation of labeled amino acid, uridine, and thymidine, into acid-insoluble material, without significantly affecting the incorporation of these precursors into the acid-soluble pool. Flow microfluorometric analyses showed that many of the INOX-treated cells became arrested in G2 + M. The results are consistent with the view that INOX affects multiple metabolic steps. The effects of INOX were quite different from those caused by typical inhibitors of ribonucleotide reductase, hydroxyurea, and 2,3-dihydro-1H-pyrazolo(2,3-a)imidazole, which very rapidly inhibited DNA synthesis and caused arrest of the cells in G1, with minimal effects on RNA and protein synthesis.

Effect of temperature and of cytochalasin B and persantin on the nonmediated permeation of non-electrolytes into cultured Novikoff rat hepatoma cells

The nonmediated permeation of L-glucose, cytosine, and prednisolone into Novikoff rat hepatoma cells followed first order kinetics with rate constants of 0.00404, 0.173, and 2.4 min-1, respectively. The constants were estimated from a nonlinear least squares fit of the integrated first order rate equation. The rate constants were independent of substrate concentration and correlated with the partition coefficients of the substances in octanol-balanced salt solution (0.00158, 0.0352, and 17.8, respectively) and olive oil-balanced salt solution mixtures which were between 10- and 100-fold lower. Arrhenius plots for the permeation of L-glucose, cytosine, and prednisolone were linear and indicated activation energies of 24.2, 28.0, and 19.6 kcal/mol, respectively. The permeation of L-glucose and cytosine, but not of prednisolone, was impeded in a concentration-dependent manner by the presence of cytochalasin B and Persantin, heretofore thought of as specific inhibitors of facilitated diffusion processes. The relative degree of decrease of the permeation rates of L-glucose and cytosine, however, differed for cytochalasin B and Persantin.

The application of rapid kinetic techniques to the transport of thymidine and 3-O-Methylglucose into Mammalian cells in suspension culture

Techniques are described by which the transport of nutrients into mammalian cells in suspension can be measured at intervals of 1.5 seconds. By application of these techniques, the existence of a saturable (Km = 85 muM), non-concentrative, transport system for thymidine was demonstrated in Novikoff rat hepatoma cells depleted of ATP. At concentrations of thymidine less than the Km, this system operated at velocities sufficient to nearly completely equilibrate intra- and extra-cellular thymidine pools within 8 seconds. In phosphorylating cells, the transport system operated with similar rapidity, so that intracellular phosphorylation was rate-limiting for the incorporation of thymidine into nucleotides. Uptake of 3-O-methylglucose occurred at comparable velocities, attaining 90% of equilibrium between internal and external pools within 25 seconds. Uptake of cytosine by simple diffusion was 100 times slower.

Alanosine toxicity in Novikoff rat hepatoma cells due to inhibition of the conversion of inosine monophosphate to adenosine monophosphate

2-Amino-3-(hydroxynitrosoamino)propionic acid (alanosine), at a concentration as low as 2.7 muM, completely inhibits the incorporation of hypoxanthine into adenosine triphosphate by cultured Novikoff rat hepatoma cells. Alanosine inhibits the first step in the conversion of inosine monophosphate to adenosine monophosphate because inosine monophosphate, but not adenylosuccinate, accumulates in treated cells. However, the alanosine inhibition is not prevented by aspartic acid, even at a concentration of 1 mM. Alanosine treatment results in the inhibition of cell division, DNA synthesis, RNA and protein synthesis (in this order), and a depletion of the cells of adenosine triphosphate. Some of the cells accumulate in late G2 or M, but the remainder become arrested in other stages of the cell cycle. All effects are due to the inhibition of adenosine monophosphate synthesis and the consequent depletion of the adenosine triphosphate pool since they are completely prevented or reversed by addition of adenine, but not hypoxanthine, to the medium. Pyrimidine nucleotide synthesis is not significantly inhibited by alanosine, since the uridine triphosphate pool is not affected and uridine fails to reverse the cytotoxicity of alanosine. Alanosine also inhibits the transport of aspartic acid, but has a much lower affinity for this transport system than aspartic acid.