Human interleukin 4 receptor confers biological responsiveness and defines a novel receptor superfamily

IL-4, a pleiotropic cytokine produced by T lymphocytes, plays an important role in immune responsiveness by regulating proliferation and differentiation of a variety of lymphoid and myeloid cells via binding to high affinity receptors. In this report we describe the isolation and functional expression of a human IL-4-R cDNA. When transfected into COS-7 cells, the cDNA encodes a 140-kD cell-surface protein. After transfection into a murine T cell line, the cDNA encodes a protein that binds human IL-4 with high affinity and can confer responsiveness to human IL-4. The predicted extracellular domain of the IL-4-R exhibits significant amino acid sequence homology with the beta subunit of the IL-2-R (p75), and the receptors for IL-6, erythropoietin, and prolactin. These receptors comprise a novel superfamily with extracellular domains characterized by four conserved cysteine residues and a double tryptophan-serine (WSXWS) motif located proximal to the transmembrane region.     

Changes in circulating leptin,leptin receptor,and gonadal hormones from infancy until advanced age in humans

We determined developmental changes in circulating levels of the soluble leptin receptor (sOB-R), leptin, and gonadal hormones in human subjects. In both sexes the rise in leptin with age was associated with a decline in sOB-R, and age-related changes in both parameters preceded the pubertal rise in gonadal hormones. Leptin levels above 10 ng/ml were a strong predictor of sOB-R concentrations, but this predictive value decreased as leptin declined. In young subjects there were no gender differences in serum leptin, but boys had higher sOB-R levels. In adults neither leptin nor sOB-R changed with age, but serum leptin was higher and sOB-R was lower in women than men. There was a significant negative correlation between sOB-R and leptin in women, but not men. The data suggest that bioavailable leptin in the circulation may be increasing more rapidly during development than indicated by total leptin levels, and that these changes may serve as one of the signals to the central nervous system that metabolic conditions are adequate to support pubertal development. Furthermore, the study provides suggestive evidence that leptin regulates the secretion of its own binding protein, but it also appears that an additional gender-specific, leptin-independent, regulatory mechanism is functional before puberty.     

Cell genetic studies on propionyl-CoA carboxylase deficient cell lines

Thirteen propionyl-CoA carboxylase (PCC)-deficient fibroblast lines were analysed for complementation by examining the incorporation of [¹⁴C]propionate into trichloroacetic-acid insoluble cellular macromolecules of polyethylene-glycol-dimethyl-sulphoxide induced heterokaryons formed by fusion of mutant cell lines. Corrections for variations in the rate of protein synthesis of the heterokaryons and individual cell lines was made by measuring the incorporation of [³H]lysine, added simultaneously with the labelled propionate.Two distinct complementation groups were found in this sample of PCC-deficient cell lines. Evidence for intragenic complementation was not obtained.     

Maternal report of attention deficit hyperactivity disorder symptoms in preschool children

Two hundred and fifty-three mothers were surveyed regarding attention deficit hyperactivity disorder (ADHD) symptoms in their preschool children (aged 2-6 years). Twenty-four children (9.5%) met DSM-IV criteria (criterion A only) for ADHD based solely on parent report. Mean ratings of the three core symptoms of ADHD (hyperactivity, impulsivity, and inattentiveness) were in the mid-range on a 1-7 point scale, with mothers indicating their children were most likely to be impulsive. Positive parental endorsement of the 18 individual DSM-IV symptoms of ADHD ranged from 4% for 'loses things necessary for tasks', to 28.4% for 'is on the go or acts as if driven by a motor'. Males and children of less-educated parents were more likely to receive endorsement of ADHD symptoms. There were no differences with respect to age of the child or birth order (first vs later born). Global ratings of hyperactivity and inattentiveness predicted overall ratings of ADHD but when classification rates were examined, high global ratings were not predictive of diagnosis. These results lend support to the notion that relying solely on parents' verbal reports of isolated ADHD symptoms may lead to over-identification of the disorder. Thus, using full DSM-IV diagnostic criteria and including standardized behaviour rating scales across multiple informants and settings, is recommended.     

Cortical gray and white brain tissue volume in adolescents and adults with autism.

BACKGROUND: A number of studies have found brain enlargement in autism, but there is disagreement as to whether this enlargement is limited to early development or continues into adulthood. In this study, cortical gray and white tissue volumes were examined in a sample of adolescents and adults with autism who had demonstrated total brain enlargement in a previous magnetic resonance imaging (MRI) study. METHODS: An automated tissue segmentation program was applied to structural MRI scans to obtain volumes of gray, white, and cerebrospinal fluid (CSF) tissue on a sample of adolescent and adult males ages 13-29 with autism (n = 23) and controls (n = 15). Regional differences for brain lobes and brain hemispheres were also examined. RESULTS: Significant enlargement in gray matter volume was found for the individuals with autism, with a disproportionate increase in left-sided gray matter volume. Lobe volume enlargements were detected for frontal and temporal, but not parietal or occipital lobes, in the subjects with autism. Age and nonverbal IQ effects on tissue volume were also observed. CONCLUSIONS: These findings give evidence for left-lateralized gray tissue enlargement in adolescents and adults with autism, and demonstrate a regional pattern of cortical lobe volumes underlying this effect.     

Health Literacy, Health Information Seeking Behaviors and Internet Use Among Patients Attending a Private and Public Clinic in the Same Geographic Area

Despite the growing body of health information available online, patients with limited health literacy may lack either internet access or skills necessary to utilize this information. Nonetheless, patients at all health literacy levels may prefer other primary sources to obtain health information. We conducted a cross-sectional study to measure health literacy of patients attending two clinics in Dallas, TX and determine associations between health literacy, health information access and internet usage before and after controlling for confounders. Patients from both clinics (county N = 265; private N = 233) completed a brief survey which included sociodemographics, internet patterns, confidence in filling out medical forms and a self-administered Newest Vital Sign to measure health literacy. In the county clinic, most patients (61.5 %) were Hispanic, had low income (<$19,000/year), limited education (<11th grade) and a high likelihood or possibility of limited health literacy (68.5 %). In the private clinic, participants were mostly black (40.4 %) or white (38.6 %), had higher incomes (≥$46,000), higher education (technical college or college) and adequate health literacy (75.1 %). The primary source of obtaining health information in both clinics was their health care professional (50.6 % county; 40.1 % private). In multivariate analyses to determine differences by health literacy level, there were no statistically significant differences between patients with limited and adequate health literacy and their primary information source. Regardless of health literacy, patients rely on their health care providers to obtain health information. These results showcase the importance of providers’ effective communication with patients to make shared decisions about their health regardless of other factors.     

Expression cloning of a human Fc receptor for IgA

IgA, the predominant isotype in secretions, mediates the neutralization and removal of environmental antigens from mucosal sites. Although cell surface receptors for the Fc region of IgA (Fc alpha R) have been implicated in a variety of immune effector mechanisms, the molecular features of Fc alpha R remain only marginally characterized. In this report, we describe the isolation of a clone from a myeloid cell line cDNA library that directs the expression of a cell surface molecule with IgA binding specificity. The cDNA encodes a peptide of Mr 30,000 including a putative transmembrane region with features atypical of conventional membrane-anchored proteins. Databank searches indicate that the human myeloid cell Fc alpha R sequence is unique, is a member of the immunoglobulin gene superfamily, and is related to Fc receptors for IgG (Fc gamma RI, II, and III) and IgE (Fc epsilon RI).