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Biomedical subjects

Sarah Parsons

Publications and source records attributed to Sarah Parsons.

8 recordsLinked to original sources
PubMed2007

Using virtual environments for teaching social understanding to 6 adolescents with autistic spectrum disorders.

Six teenagers with Autistic Spectrum Disorders (ASDs) experienced a Virtual Environment (VE) of a café. They also watched three sets of videos of real cafés and buses and judged where they would sit and explained why. Half of the participants received their VE experience between the first and second sets of videos, and half experienced it between the second and third. Ten naïve raters independently coded participants' judgments and reasoning. In direct relation to the timing of VE use, there were several instances of significant improvement in judgments and explanations about where to sit, both in a video of a café and a bus. The results demonstrate the potential of Virtual Reality for teaching social skills.

Adolescent↗
PubMed2006

Surgical repair of a syphilitic aneurysm of the distal arch and descending aorta.

Cardiovascular syphilis, which used to be a well-recognized manifestation of tertiary syphilis, has become a rarity. In this report we describe a 47-year-old man presenting with an aneurysm of the distal arch and proximal descending aorta, a somewhat unusual presentation for a syphilitic aneurysm, and discuss the clinical features of cardiovascular syphilis.

Aneurysm, Infected↗
PubMed2005

Development of rationally designed affinity-based drug delivery systems.

Many drug delivery systems have been developed to provide sustained release of proteins in vivo. However, the ability to predict and control the rate of release from delivery systems is still a challenge. Toward this goal, we screened a random drug-binding peptide library (12 amino acids) to identify peptides of varying (i.e. low, moderate, and high) affinity for a model polysaccharide drug (heparin). Peptide domains of varying affinity for heparin identified from the library were synthesized using standard solid phase chemistry. A mathematical model of drug release from a biomaterial scaffold containing drug-binding peptide domains identified from the library was developed. This model describes the binding kinetics of drugs to the peptides, the diffusion of free drug, and the kinetics of enzymatic matrix degradation. The effect of the ratio of binding sites to drug, the effect of varying the binding kinetics and the rate of enzymatic matrix degradation on the rate of drug release was examined. The in vitro release of the model drug from scaffold containing the peptide drug-binding domains was measured. The ability of this system to deliver and modulate the biological activity of protein drugs was also assessed using nerve growth factor (NGF) in a chick dorsal root ganglia (DRG) neurite extension model. These studies demonstrate that our rational approach to drug delivery system design can be used to control drug release from tissue-engineered scaffolds and may be useful for promoting tissue regeneration in vivo.

Affinity Labels↗
PubMed2005

Adenovirus tubulointerstitial nephritis presenting as a renal allograft space occupying lesion.

This report describes a case of adenovirus infection in a renal allograft 36 days after transplantation that presented with transient macroscopic hematuria, prominent systemic features and acute renal dysfunction. The patient had persistent high fevers despite broad antibiotic cover. A CT scan demonstrated a new discrete space occupying lesion in the allograft, which was devoid of blood flow on Doppler sonography. A targeted renal biopsy showed florid and focal necrotizing interstitial nephritis with intranuclear tubular viral inclusions. Treatment with ganciclovir and reduction in immunosuppression resulted in a rapid improvement. Immunohistochemistry and electron microscopy confirmed adenovirus infection. This case demonstrates an uncommon presentation of necrotizing adenoviral nephropathy, which should be considered in cases of renal allograft mass lesions.

Adenoviridae↗
PubMed2005

Do adolescents with autistic spectrum disorders adhere to social conventions in virtual environments?

The potential for using virtual environments (VEs) in educational contexts for people with autistic spectrum disorders (ASDs) has been recognized. However, very little is known about how people with ASDs interpret and understand VEs. This study aimed to investigate this directly with a group of 12 adolescents with ASDs, each individually matched with comparison participants. Participants were presented with VEs to assess whether they adhered to particular social conventions, such as not walking across grass and flowerbeds en route to a café, or not walking between two people (ostensibly involved in conversation) en route to the bar. Whilst a significant minority of the ASD group adhered to the social conventions, others displayed substantial 'off-task' behaviour and a limited understanding of the VE. It is suggested that some individuals with an ASD, low verbal IQ and weak executive ability require the most support to complete tasks successfully in the VE.

Adolescent↗
PubMed2004

The use and understanding of virtual environments by adolescents with autistic spectrum disorders.

The potential of virtual environments for teaching people with autism has been positively promoted in recent years. The present study aimed to systematically investigate this potential with 12 participants with autistic spectrum disorders (ASDs), each individually matched with comparison participants according to either verbal IQ or performance IQ, as well as gender and chronological age. Participants practised using a desktop 'training' virtual environment, before completing a number of tasks in a virtual café. We examined time spent completing tasks, errors made, basic understanding of the representational quality of virtual environments and the social appropriateness of performance. The use of the environments by the participants with ASDs was on a par with their PIQ-matched counterparts, and the majority of the group seemed to have a basic understanding of the virtual environment as a representation of reality. However, some participants in the ASD group were significantly more likely to be judged as bumping into, or walking between, other people in the virtual scene, compared to their paired matches. This tendency could not be explained by executive dysfunction or a general motor difficulty. This might be a sign that understanding personal space is impaired in autism. Virtual environments might offer a useful tool for social skills training, and this would be a valuable topic for future research.

Adolescent↗
PubMed2003

Spontaneous activation and signaling by overexpressed epidermal growth factor receptors in glioblastoma cells.

Overexpressed epidermal growth receptor factor receptors (EGFRs) are thought to contribute to the malignant phenotype of human glioblastomas (GBMs), but the mechanism is not well understood. We found that SKMG-3 cells, a rare GBM cell line that maintains EGFR gene amplification in vitro, produced high levels of EGFR protein. The cells also expressed the related receptors HER2/neu and HER4, but not HER3. Immunoblots and tryptic phosphopeptide maps showed that the SKMG-3 EGFRs were intact and functional and that a subset of these receptors were spontaneously autophosphorylated. EGF treatment stimulated phosphorylation of the EGFRs as well as the downstream effectors Erk, AKT1, stat3 and c-Cbl. Under minimal growth conditions, the unstimulated SKMG-3 cells contained constitutively phosphorylated Erk and AKTI but no detectable stat3 DNA-binding complexes. The EGFR kinase inhibitor PD158780 reduced the constitutive phosphorylation of the receptor and Erk but not that of AKT1. In contrast, inhibition of phosphatidylinositol-3-kinase (PI3K) blocked the constitutive phosphorylation of Erk and AKT-1 but not the EGFR. We conclude that the SKMG-3 cells represent the subset of GBMs with amplified EGFR genes that overexpress intact receptors. The results also suggest that in some GBMs, signals from overexpressed EGFRs contribute to the constitutive phosphorylation of Erk, but these signals may not required for the constitutive activation of PI3K or AKT1.

Breast Neoplasms↗