Biomedical subjects

Susan Sullivan

Publications and source records attributed to Susan Sullivan.

8 recordsLinked to original sources

PubMed2006

Differences in the way older and younger adults rate threat in faces but not situations.

We compared young and healthy older adults' ability to rate photos of faces and situations (e.g., sporting activities) for the degree of threat they posed. Older adults did not distinguish between more and less dangerous faces to the same extent as younger adults did. In contrast, we found no significant age differences in young and older adults' ability to distinguish between high- and low-danger situations. The differences between young and older adults on the face task were independent of age differences in older adults' fluid IQ. We discuss results in relation to differences between young and older adults on emotion-recognition tasks; we also discuss sociocognitive and neuropsychological (e.g., amygdala) theories of aging.

Adolescent↗

PubMed2006

CD8+ T-Cell responses to Trypanosoma cruzi are highly focused on strain-variant trans-sialidase epitopes.

CD8+ T cells are crucial for control of a number of medically important protozoan parasites, including Trypanosoma cruzi, the agent of human Chagas disease. Yet, in contrast to the wealth of information from viral and bacterial infections, little is known about the antigen specificity or the general development of effector and memory T-cell responses in hosts infected with protozoans. In this study we report on a wide-scale screen for the dominant parasite peptides recognized by CD8+ T cells in T. cruzi-infected mice and humans. This analysis demonstrates that in both hosts the CD8+ T-cell response is highly focused on epitopes encoded by members of the large trans-sialidase family of genes. Responses to a restricted set of immunodominant peptides were especially pronounced in T. cruzi-infected mice, with more than 30% of the CD8+ T-cell response at the peak of infection specific for two major groups of trans-sialidase peptides. Experimental models also demonstrated that the dominance patterns vary depending on the infective strain of T. cruzi, suggesting that immune evasion may be occurring at a population rather than single-parasite level.

Adult↗

PubMed2005

The TEAM project: the effectiveness of smoking cessation intervention with hospital patients.

BACKGROUND: This study evaluated the effectiveness of three smoking cessation interventions for this population: (1) modified usual care (UC); (2) brief advice (A); and (3) brief advice plus more extended counseling during and after hospitalization (A + C). METHODS: Smokers (2,095) who were in-patients in four hospitals were randomly assigned to condition. Smoking status was ascertained via phone interview 7 days and 12 months post-discharge. At 12 months, reports of abstinence were validated by analysis of saliva cotinine. Intent to treat analyses were performed. RESULTS: At 7-day follow-up, 24.2% of participants reported abstinence in the previous 7 days. There were no differences between conditions. At 12-month follow-up, self-reported abstinence was significantly higher in the A + C condition (UC (15.0%) vs. A (15.2%) vs. A + C (19.8%)). There was no significant difference among conditions in cotinine-validated abstinence, however (UC (8.8%) vs. A (10.0%) vs. A + C (9.9%)). CONCLUSIONS: These interventions for hospital in-patients did not increase abstinence rates. Features of the study that might have contributed to this finding were the inclusiveness of the participation criteria, the fact that pharmacological aids were not provided, and a stage-matching approach that resulted in less intensive counseling for participants unwilling to set a quit date.

Adolescent↗

PubMed2005

Evolving risk for thromboembolism in spinal cord injury (SPIRATE Study).

OBJECTIVE: To compare the frequency of venous thromboembolism (VTE) in patients examined during 1992-1995 with those examined during 1999-2003. DESIGN: A comprehensive review of the charts of all patients admitted between late 1999 and early 2003 for rehabilitation after spinal cord injury. Only records, including evidence for objective testing for VTE (ultrasound, venography, lung scanning) were included, and patients having inferior vena cava filter placement or previous VTE were excluded. Analysis variables included type and location of spinal cord injury, American Spinal Injury Association classification, concomitant injuries, surgical procedures, complications, preexisting illnesses, and use of antithrombotic prophylaxis. Using univariate optimal discriminant analysis, data from the current group of patients were compared with a previous study of 243 subjects examined between 1992 and 1995. RESULTS: The current sample consisted of 76 persons with acute spinal cord injury, of whom six had VTE (7.9%). As compared with the frequency of VTE in the previous patient sample (21%), this represented a significant decrease (P<0.01). The major differences between the current and previous patient samples were a decrease in the use of unfractionated heparin (15.8% vs. 56.8%, P<0.0001) and an increase in the use of low molecular weight heparin (81.6% vs. 59.7%, P<0.0001). CONCLUSIONS: VTE has been a common and occasionally lethal complication in persons with spinal cord injury. The recent switch from unfractionated heparin to low molecular weight heparin for the prevention of VTE has coincided with a decrease in the frequency of this complication in patients with spinal cord injury.

Adult↗

PubMed2004

Emotion recognition deficits in the elderly.

In two studies, healthy elderly adults were poor at recognizing certain emotions. In study one, an emotion face morphed to express a new emotion. The elderly were impaired when recognizing anger and sadness, whereas no differences were found between the two age groups in recognizing fear or happiness, or in a task requiring reasoning about non=emotion stimuli. In study two, the elderly were impaired when judging which of two faces was more angry, sad, or fearful, but they were not impaired when judging other emotions or when judging which of two beakers was more full. The elderly were also impaired when matching emotion sounds to angry, sad, and disgusted faces, but not to other emotions and not when matching non-emotion (e.g., machine) sounds to machines. Elderly deficits were independent of performance on a task requiring basic face processing (gender recognition). Overall, the results provide support for an age-related decline in the recognition of some emotions that is independent of changes in perceptual abilities, processing speed, fluid IQ, basic face processing abilities, and reasoning about non face stimuli. Recognition of emotion stimuli might be mediated by regions of the brain that are independent from those associated with a more general cognitive decline.

Adult↗

PubMed2004

Bone morphogenetic proteins regulate ionotropic glutamate receptors in human retina.

Bone morphogenetic proteins (BMPs) are required for the development of retina, but their role in the mature eye is unknown. We therefore examined the expression of BMP-7 in adult human retina and assessed its effects on horizontal cells cultured from adult human retina. BMP-7 expression was detected in all retinal layers, with high levels of expression being present in the inner and outer nuclear layers. Human horizontal cells, found in the inner nuclear layer, possess both AMPA and kainate receptors, and glutamatergic agonists that activate these receptors induce prominent inward currents. Exposure to BMP-7 suppresses the kainate receptor current but enhances the AMPA receptor current. BMP-6, activin, and cartilage-derived morphogenic protein-2 (CDMP-2) have similar effects to BMP-7 and act just as rapidly (< 1 s). In contrast BMP-2 and transforming growth factor-beta2 are inactive. The actions of BMP-7 on both AMPA and kainate receptors were blocked by the nonselective kinase inhibitor, staurosporine. In contrast, the serine/threonine kinase inhibitors blocked only the effects of BMP-7 on the AMPA current. Thus, BMPs rapidly and differentially regulate two ionotropic glutamate receptors through distinct pathways, neither of which involves nuclear regulatory activity. These observations suggest that BMPs might modify synaptic function in the mature nervous system.

Adolescent↗

PubMed2004

Social understanding: How does it fare with advancing years?

Until recently, theory of mind abilities have received little attention beyond the childhood years. However, pioneering work carried out by Happé, Winner, and Brownell (1998) has opened the doors on a new and exciting area of research that examines theory of mind abilities in later years. Happé et al. reported that theory of mind performance was superior in the elderly. Yet, in direct contrast to these findings, Maylor, Moulson, Muncer, and Taylor (2002) report a decline in theory of mind abilities with advancing years. We used Happé et al.'s task and, like Maylor et al., found a decline in theory of mind abilities in the elderly. Yet this deficit was related to a decline in fluid abilities. We then examined whether deficits in social understanding in the elderly could also be independent of fluid abilities. We used two new tasks; identifying emotions from still photos and identifying emotions and cognitions from video clips. Again we found a decline in social understanding in the elderly, and in this case, the decline was independent of changes in fluid abilities.

Aged↗

PubMed2003

Human corneal stem cells display functional neuronal properties.

PURPOSE: Human corneal limbal stem cells mature and repopulate the superficial layers of the cornea throughout life. In this study, we tested the hypothesis that human corneal stem cells, derived from neural ectoderm, can exhibit functional neuronal properties. METHODS: Human corneal limbal tissue (donor age 6 weeks to 92 years) was obtained from Upstate New York Transplant Services. Tissues were grown as explants on coverslips in DMEM with 10% calf serum. After 7-14 days in vitro, tissues on coverslips were double-immunostained for the stem cell marker, p63, along with nestin and neurotransmitter receptors GABA, dopamine, serotonin, glycine or acetylcholine. We also carried out whole cell current clamp and voltage clamp recordings on corneal stem cell cultures in order to determine their functional neurophysiological properties. RESULTS: Co-localization of p63 with nestin, GABA receptor, glycine receptor, and serotonin receptor immunoreactivity was seen in a small number of cells in the corneal stem cell cultures. The resting potential of corneal stem cells was relatively low, approximately -13+/-8 mV (n=13; range -6 mV to -40 mV) measured in current clamp. No action potentials or voltage sensitive Na+ and K+ currents were detected. However, in a small number of cells, kainic acid (0.5 mM), a non-NMDA glutamate receptor agonist, and GABA induced a small inward current. Glutamate receptor antagonist, CNQX, and GABA receptor antagonist, bicuculline and CGP-35348 blocked the agonist response. CONCLUSIONS: A subpopulation of human corneal stem cells exhibit neuronal properties in vitro, as evidenced by immunoreactivity to nestin, GABA receptor, glycine receptor, and serotonin receptor, as well as functional neurophysiological responses to GABA and kainic acid. Human corneal stem cells may represent a potential source of non-embryonic, autologous, surgically-accessible graft material with neuronal potential.

Adolescent↗