Encapsulation of α-Particle-Emitting 225Ac3+ Ions Within Carbon Nanotubes.

UNLABELLED: (225)Ac(3+) is a generator of α-particle-emitting radionuclides with 4 net α-particle decays that can be used therapeutically. Targeting (225)Ac(3+) by use of ligands conjugated to traditional bifunctional chelates limits the amount of (225)Ac(3+) that can be delivered. Ultrashort, single-walled carbon nanotubes (US-tubes), previously demonstrated as sequestering agents of trivalent lanthanide ions and small molecules, also successfully incorporate (225)Ac(3+). METHODS: Aqueous loading of both (225)Ac(3+) ions and Gd(3+) ions via bath sonication was used to construct (225)Ac@gadonanotubes ((225)Ac@GNTs). The (225)Ac@GNTs were subsequently challenged with heat, time, and human serum. RESULTS: US-tubes internally loaded with both (225)Ac(3+) ions and Gd(3+) ions show 2 distinct populations of (225)Ac(3+) ions: one rapidly lost in human serum and one that remains bound to the US-tubes despite additional challenge with heat, time, and serum. The presence of the latter population depended on cosequestration of Gd(3+) and (225)Ac(3+) ions. CONCLUSION: US-tubes successfully sequester (225)Ac(3+) ions in the presence of Gd(3+) ions and retain them after a human serum challenge, rendering (225)Ac@GNTs candidates for radioimmunotherapy for delivery of (225)Ac(3+) ions at higher concentrations than is currently possible for traditional ligand carriers.

Stable confinement of positron emission tomography and magnetic resonance agents within carbon nanotubes for bimodal imaging.

AIMS: Simultaneous positron emission tomography/MRI has recently been introduced to the clinic and dual positron emission tomography/MRI probes are rare and of growing interest. We have developed a strategy for producing multimodal probes based on a carbon nanotube platform without the use of chelating ligands. MATERIALS & METHODS: Gd(3+) and (64)Cu(2+) ions were loaded into ultra-short single-walled carbon nanotubes by sonication. Normal, tumor-free athymic nude mice were injected intravenously with the probe and imaged over 48 h. RESULTS & CONCLUSION: The probe was stable for up to 24 h when challenged with phosphate-buffered saline and mouse serum. Positron emission tomography imaging also confirmed the stability of the probe in vivo for up to 48 h. The probe was quickly cleared from circulation, with enhanced accumulation in the lungs. Stable encapsulation of contrast agents within ultra-short single-walled carbon nanotubes represents a new strategy for the design of advanced imaging probes with variable multimodal imaging capabilities.

Pica in persons with developmental disabilities: approaches to treatment.

Pica is a very serious problem in which an individual ingests substances without nutrition value, such as paper and paint. As this behavior is often life-threatening resulting in surgery, pica has received attention from researchers for several decades. During that time, a number of interventions have been devised, such as behavioral methods (e.g., aversive stimuli, overcorrection, time-out, reinforcement) and biological interventions (e.g., pharmacotherapy, nutritional supplements). This paper is a broad review of the research on treatment studies for this problem, with a focus on persons with autism and/or intellectual disability (ID), which constitutes almost all of the published treatment papers. In addition, strengths and weaknesses of different pica treatments are discussed. Upon review, applied behavior analysis (ABA) was found to have the most robust empirical support to treat this behavior. Most clinicians are drifting away from aversive techniques and relying on more positive procedures to guide their treatment plans. The implications of current status and future directions for research are also addressed.

Scaling methods to measure psychopathology in persons with intellectual disabilities.

Psychopathology prior to the last four decades was generally viewed as a set of problems and disorders that did not occur in persons with intellectual disabilities (ID). That notion now seems very antiquated. In no small part, a revolutionary development of scales worldwide has occurred for the assessment of emotional problems in persons with ID. The first standardized test to emerge was the Psychopathology Instrument for Mentally Retarded Adults (PIMRA) in 1984. Since that time, an impressive number of measures of general psychopathology have emerged for adults and children as well as for persons across the full range of levels of ID. The purpose of this review was to provide a description of available measures, to review papers published on these measures, and to discuss emerging trends in test development. The trends in this body of information for enhancing differential diagnosis of psychopathology in persons with ID are discussed.

Comorbidity of physical and motor problems in children with autism.

Autism and the related pervasive developmental disorders are a heavily researched group of neurodevelopmental conditions. In addition to core symptoms, there are a number of other physical and motor conditions that co-occur at high rates. This paper provides a review of factors and behaviors that correlate highly with disorders on the autism spectrum. Among these conditions are premature birth, birth defects, gross and fine motor skills, and obesity. Each of these topics is addressed, and what researchers have found are presented. These data have important implications for the types of collateral behaviors that should be assessed and treated, along with the core symptoms of autism.

Nanotechnology and MRI contrast enhancement.

Technical advances in nanotechnology are creating novel classes of MRI contrast-enhancing agents. These nanomaterials offer much higher relaxivities than most current clinical contrast agents, which translates into greater MRI contrast enhancement. These nanoscale agents also have the potential to revolutionize in vivo applications of contrast-enhanced MRI since they offer the multiple advantages of low toxicities, extremely high relaxivities and cell internalization capabilities. In this review, we discuss three types of such contrast agents currently in use or under development for medical imaging: small particles of iron oxide, fullerenes encapsulating Gd(3+) ions (gadofullerenes) and single-walled carbon nanotube nanocapsules encapsulating Gd(3+) ion clusters (gadonanotubes). The latest developments and projected future applications of these nanotechnology-inspired contrast agents in the field of medical imaging are also discussed.

Social-skills treatments for children with autism spectrum disorders: an overview.

Marked advances in the treatment of children with autism spectrum disorders (ASDs) has occurred in the past few decades, primarily using applied behavior analysis. However, reviews of trends in social skills treatment for children with ASDs have been scant, despite a robust and growing empirical literature on the topic. In this selective review of 79 treatment studies, the authors note that the research has been particularly marked by fragmented development, using a range of intervention approaches and definitions of the construct. Modeling and reinforcement treatments have been the most popular model from the outset, with most studies conducted in school settings by teachers or psychologists. Investigators have been particularly attentive to issues of generalization and follow-up. However, large-scale group studies and comparisons of different training strategies are almost nonexistent. These trends and their implications for future research aimed at filling gaps in the existing literature are discussed.

Classifying mental retardation and specific strength and deficit areas in severe and profoundly mentally retarded persons with the MESSIER.

The MESSIER, a measure of social and communication skills and the Vineland Social Maturity Scale were administered to 618 severe and profoundly mentally retarded adults. The goal of the study was to establish the potential utility of the MESSIER for classifying level of intellectual disability in this group. Comparing MESSIER scores to previously established DSM-IV-TR diagnosis, 86% of the severe and 80% of the profoundly mentally retarded persons were correctly classified. The implications of these data in using the MESSIER for classification and treatment planning are discussed.

The development and factor structure of the Functional Assessment for multiple causaliTy (FACT).

Since behavioral intervention is linked to the findings of a functional assessment, the reality of behaviors maintained by multiple functions is a frequent and troublesome issue for clinicians and researchers. Current methods of functional assessment provide little help in the way of providing information useful for prioritizing intervention strategies for problematic behaviors maintained by multiple functions. In an effort to account for this deficiency, we developed the Functional Assessment for multiple CausaliTy (FACT). The FACT is an informant-based, forced-choice measure designed to identify the most prominent function associated with the occurrence of problem behaviors. In the present study, we describe the factor structure and internal consistency of the FACT. Suggestions are provided for future validation strategies.

Psychopharmacology research for individuals with mental retardation: methodological issues and suggestions.

Psychotropic medications are frequently prescribed for behavior problems and/or psychopathology among individuals with mental retardation (MR). Unfortunately, the methodological integrity of scientific studies that support the use of medications among this population is often lacking. A recent review of the literature revealed that many of the studies that have assessed the efficacy of psychotropic medications for individuals with MR are methodologically flawed. Thus, we have detailed suggestions to improve the quality of future medication studies and avoid the methodological problems that prevent the scientific advancement of psychopharmacological research among individuals with MR.

Representation of international authorship across prominent journals in the field of mental retardation.

This article is a reflection of international publication trends across prominent journals in the field of mental retardation. Journals reviewed were the Journal of Applied Behavior Analysis, Journal of Intellectual Disability Research, Mental Retardation, and Research in Developmental Disabilities. Percentage of authors from the United States (US) and other countries were evaluated. US authors represented 84-91% in US journals, while US representation in foreign journals was much lower at 21%. The implications of these findings are discussed.