Neurochemical correlates of autistic disorder: A review of the literature

Review of neurochemical investigations in autistic disorder revealed that a wide array of transmitter systems have been studied, including serotonin, dopamine, norepinephrine, acetylcholine, oxytocin, endogenous opioids, cortisol, glutamate, and gamma-aminobutyric acid (GABA). These studies have been complicated by the fact that autism is a very heterogeneous disorder which often presents with comorbid behavioral problems. In addition, many of these studies employed very small samples and inappropriate control groups, making it difficult to draw conclusions with confidence. Overall, serotonin appears to have the most empirical evidence for a role in autism, but this requires further investigation and replication. There is little support for the notion that a dysfunction of norepinephrine or the endogenous opioids are related to autism. The role of dopaminergic functioning has not been compelling thus far, though conflicting findings on central dopamine turnover require further study. Promising new areas of study may include possible dysfunction of the cholinergic system, oxytocin, and amino acid neurotransmitters. Implications for pharmacotherapy are briefly discussed for each neurotransmitter system with brief research examples. Review of this work emphasizes the need for future studies to control for subject variables, such as race, sex, pubertal status, and distress associated with blood draws, which can affect measures of neurochemical function. In addition, research in neurochemistry must continue to work in concert with other subspecialties to form a more comprehensive and theory-based approach to the neurobiological correlates of autistic disorder

Evidence for three subtypes of repetitive behavior in autism that differ in familiality and association with other symptoms

Restricted repetitive behaviors (RRBs) are a core feature of autism and consist of a variety of behaviors, ranging from motor stereotypies to complex circumscribed interests. The objective of the current study was to examine the structure of RRBs in autism using relevant items from the Autism Diagnostic Interview-Revised in a sample of 316 individuals with autistic disorder

High glucose represses β-klotho expression and impairs fibroblast growth factor 21 action in mouse pancreatic islets: involvement of peroxisome proliferator-activated receptor γ signaling

Circulating fibroblast growth factor 21 (FGF21) levels are elevated in diabetic subjects and correlate directly with abnormal glucose metabolism, while pharmacologically administered FGF21 can ameliorate hyperglycemia. The pancreatic islet is an FGF21 target, yet the actions of FGF21 in the islet under normal and diabetic conditions are not fully understood. This study investigated the effects of high glucose on islet FGF21 actions in a diabetic mouse model by investigating db/db mouse islet responses to exogenous FGF21, the direct effects of glucose on FGF21 signaling, and the involvement of peroxisome proliferator-activated receptor γ (PPARγ) in FGF21 pathway activation. Results showed that both adult db/db mouse islets and normal islets treated with high glucose ex vivo displayed reduced β-klotho expression, resistance to FGF21, and decreased PPARγ expression. Rosiglitazone, an antidiabetic PPARγ ligand, ameliorated these effects. Our data indicate that hyperglycemia in type 2 diabetes mellitus may lead to FGF21 resistance in pancreatic islets, probably through reduction of PPARγ expression, which provides a novel mechanism for glucose-mediated islet dysfunction

A Nonparametric Method for the Derivation of α/β Ratios from the Effect of Fractionated Irradiations

Multifractionation isoeffect data are commonly analysed under the assumption that cell survival determines the observed tissue or tumour response, and that it follows a linear-quadratic dose dependence. The analysis is employed to derive the α/β ratios of the linear-quadratic dose dependence, and different methods have been developed for this purpose. A common method uses the so-called Fe plot. A more complex but also more rigorous method has been introduced by Lam et al. (1979). Their method, which is based on numerical optimization procedures, is generalized and somewhat simplified in the present study. Tumour-regrowth data are used to explain the nonparametric procedure which provides α/β ratios without the need to postulate analytical expressions for the relationship between cell survival and regrowth delay

Association Between Raised Blood Pressure and Dysglycemia in Hong Kong Chinese

OBJECTIVE—To investigate the association between raised blood pressure and dysglycemia

Age-Related Differences in Restricted Repetitive Behaviors in Autism Spectrum Disorders

Restricted repetitive behaviors (RRBs) were examined in a large group of children, adolescents and adults with ASD in order to describe age-related patterns of symptom change and association with specific contextual factors, and to examine if the patterns of change are different for the various types of RRBs. Over 700 individuals with ASD were rated on the Repetitive Behavior Scale – Revised. RRBs were less frequent and less severe among older than younger individuals, corroborating that autism symptoms abate with age. Our findings further suggest that repetitive behaviors are a heterogeneous group of behaviors, with the subtypes of RRBs having their own individual patterns across the lifespan, and in some cases, a differential association with age depending on intellectual functioning

Circulating Levels of Adipocyte and Epidermal Fatty Acid–Binding Proteins in Relation to Nephropathy Staging and Macrovascular Complications in Type 2 Diabetic Patients

OBJECTIVE—To investigate the relationships of serum adipocyte fatty acid–binding protein (A-FABP) and epidermal fatty acid–binding protein (E-FABP) with renal dysfunction and macrovascular complications in type 2 diabetic patients

Adiponectin Prevents Diabetic Premature Senescence of Endothelial Progenitor Cells and Promotes Endothelial Repair by Suppressing the p38 MAP Kinase/p16INK4A Signaling Pathway

OBJECTIVE - A reduced number of circulating endothelial progenitor cells (EPCs) are casually associated with the cardiovascular complication of diabetes. Adiponectin exerts multiple protective effects against cardiovascular disease, independent of its insulin-sensitizing activity. The objective of this study was to investigate whether adiponectin plays a role in modulating the bioavailability of circulating EPCs and endothelial repair. RESEARCH DESIGN AND METHODS - Adiponectin knockout mice were crossed with db+/- mice to produce db/db diabetic mice without adiponectin. Circulating number of EPCs were analyzed by flow cytometry. Reendothelialization was evaluated by staining with Evans blue after wire-induced carotid injury. RESULTS - In adiponectin knockout mice, the number of circulating EPCs decreased in an age-dependent manner compared with the wild-type controls, and this difference was reversed by the chronic infusion of recombinant adiponectin. In db/db diabetic mice, the lack of adiponectin aggravated the hyperglycemia-induced decrease in circulating EPCs and also diminished the stimulatory effects of the PPARγ agonist rosiglitazone on EPC production and reendothelialization. In EPCs isolated from both human peripheral blood and mouse bone marrow, treatment with adiponectin prevented high glucose-induced premature senescence. At the molecular level, adiponectin decreased high glucose-induced accumulation of intracellular reactive oxygen species and consequently suppressed activation of p38 MAP kinase (MAPK) and expression of the senescence marker p16INK4A. CONCLUSIONS - Adiponectin prevents EPC senescence by inhibiting the ROS/p38 MAPK/p16 INK4A signaling cascade. The protective effects of adiponectin against diabetes vascular complications are attributed in part to its ability to counteract hyperglycemia-mediated decrease in the number of circulating EPCs. © 2010 by the American Diabetes Association.published_or_final_versio

Respiratory symptoms of Swiss people with primary ciliary dyskinesia.

Background Mostly derived from chart reviews, where symptoms are recorded in a nonstandardised manner, clinical data about primary ciliary dyskinesia (PCD) are inconsistent, which leads to missing and unreliable information. We assessed the prevalence and frequency of respiratory and ear symptoms and studied differences by age and sex among an unselected population of Swiss people with PCD. Methods We sent a questionnaire that included items from the FOLLOW-PCD standardised questionnaire to all Swiss PCD registry participants. Results We received questionnaires from 74 (86%) out of 86 invited persons or their caregivers (median age 23 years, range 3-73 years), including 68% adults (≥18 years) and 51% females. Among participants, 70 (94%) reported chronic nasal symptoms; most frequently runny nose (65%), blocked nose (55%) or anosmia (38%). Ear pain and hearing problems were reported by 58% of the participants. Almost all (99%) reported cough and sputum production. The most common chronic cough complications were gastro-oesophageal reflux (n=11; 15%), vomiting (n=8; 11%) and urinary incontinence (n=6; 8%). Only nine (12%) participants reported frequent wheeze, which occurred mainly during infection or exercise, while 49 (66%) reported shortness of breath, and 9% even at rest or during daily activities. Older patients reported more frequent nasal symptoms and shortness of breath. We found no difference by sex or ultrastructural ciliary defect. Conclusion This is the first study to describe patient-reported PCD symptoms. The consistent collection of standardised clinical data will allow us to better characterise the phenotypic variability of the disease and study disease course and prognosis

Children with autism demonstrate circumscribed attention during passive viewing of complex social and nonsocial picture arrays

Although circumscribed interests are a hallmark characteristic of autism spectrum disorders, providing a means for quantifying their functional impairment has proven difficult. We developed a passive viewing task to measure aspects of visual attention in children with autism spectrum disorders and typically developing controls. Task stimuli included picture arrays that were matched for social and nonsocial content. Nonsocial content was balanced to include items related to circumscribed interests (e.g., trains) as well as more commonplace items (e.g., furniture). Discrete aspects of gaze behavior were quantified using eye-tracking technology. Results indicate that visual attention in the autism group was more circumscribed (as indicated by the exploration of fewer images), more perseverative (as indicated by longer fixation times per image explored), and more detail oriented (as indicated by a greater number of discrete fixations on explored images). This pattern of results was similar for both social and object arrays. Within the autism group, overall severity of repetitive behavior symptoms correlated positively with exploration of object pictures and negatively with perseveration on social pictures. Results suggest that children with autism have a domain-general pattern of atypical visual attention that may represent an exaggeration of a typical attentional process and is related to a tendency to perseverate on images of interest and explore them in a more detail-oriented manner. Discrete measures of visual attention may therefore provide a reasonable means of quantifying aspects of the repetitive behavior phenotype in autism