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Biomedical subjects

C Ecker

Publications and source records attributed to C Ecker.

14 recordsLinked to original sources
PubMed2006

Neural responses to dynamic expressions of fear in schizophrenia.

Abnormalities in social functioning are a significant feature of schizophrenia. One critical aspect of these abnormalities is the difficulty these individuals have with the recognition of facial emotions, particularly negative expressions such as fear. The present work focuses on fear perception and its relationship to the paranoid symptoms of schizophrenia, specifically, how underlying limbic system structures (i.e. the amygdala) react when probed with dynamic fearful facial expressions. Seven paranoid and eight non-paranoid subjects (all males) with a diagnosis of schizophrenia took part in functional magnetic resonance imaging study (1.5T) examining neural responses to emerging fearful expressions contrasted with dissipating fearful expressions. Subjects viewed emerging and dissipating expressions while completing a gender discrimination task. Their brain activation was compared to that of 10 healthy male subjects. Increased hippocampal activation was seen in the non-paranoid group, while abnormalities in the bilateral amygdalae were observed only in the paranoid individuals. These patterns may represent trait-related hippocampal dysfunction, coupled with state (specifically paranoia) related amygdala abnormalities. The findings are discussed in light of models of paranoia in schizophrenia.

Adolescent↗
PubMed2006

Blowing DNA bubbles.

We report here experimental observations which indicate that topologically or covalently formed polymer loops embedded in an ultrathin liquid film on a solid substrate can be "blown" into circular "bubbles" during scanning force microscopy (SFM) imaging. In particular, supercoiled vector DNA has been unraveled, moved, stretched, and overstretched to two times its B-form length and then torn apart. We attribute the blowing of the DNA bubbles to the interaction of the tapping SFM tip with the ultrathin liquid film.

DNA↗
PubMed1997

Topography and dipole analysis of reafferent electrical brain activity following the Bereitschaftspotential.

The cerebral events related to limb movements can be studied noninvasively with the method of evoked potentials. In this study, a brain potential is analysed that follows the onset of a simple finger movement. Because this potential occurred after active as well as after passive movements, its previously alleged reafferent somatosensory nature is confirmed in this study. Detailed topographic analysis revealed that this potential has the same polarity and merges with the preceeding Bereitschaftspotential (BP; in the active movement) at central electrodes, whereas at parietal electrodes polarity is opposite to the BP. In individual subjects, the maximum of the BP and the peak of the reafferent potential are separated by a small gap, previously described as pre-motion positivity. A comparison with the N20 potential of the electrically evoked somatosensory potential showed similar potential topography, albeit opposite polarity. The dipole analysis supported the view that the reafferent and the electrically evoked potentials are likely to arise from the same cortical area, namely the primary somatosensory cortex.

Adult↗
PubMed1996

Risk factors for relinquishment of dogs to an animal shelter.

OBJECTIVE: To identify canine and household characteristics associated with relinquishment of a pet dog to an animal shelter. DESIGN: Case-control study. SAMPLE POPULATION: Households that relinquished dogs for adoption (case households) and a random sample of current dog-owning households in the same community (control households). RESULTS: Potentially modifiable factors that explained the highest proportion of relinquishment were owners not participating in dog obedience classes after acquisition, lack of veterinary care, owning a sexually intact dog, inappropriate care expectations, and dogs having daily or weekly inappropriate elimination. Dogs obtained from shelters, kept in crates, or acquired at > or = 6 months of age were at increased risk of relinquishment. Greater purchase price was associated with decreased risk of relinquishment, but relinquishment was not associated with the degree of planning to acquire the dog. Dogs with behavioral problems and little veterinary care were at greater risk of relinquishment than were dogs with regular veterinary care, and behavioral problems were associated with inappropriate care expectations. CLINICAL IMPLICATIONS: Risk factors identified in this study can be modified by dog owners and veterinarians to decrease the estimated 2 million dogs euthanatized annually in animal shelters. Veterinarians should educate owners about typical dog behavior, routine care requirements and training, and the importance of regular veterinary visits; should incorporate wellness concepts in their practice; and should focus on preventive medicine and behavioral consultation.

Age Factors↗
PubMed1996

Risk factors for relinquishment of cats to an animal shelter.

OBJECTIVE: To identify feline and household characteristics associated with relinquishment of a pet cat to an animal shelter. DESIGN: Case-control study. SAMPLE POPULATION: Households that relinquished cats for adoption (case households) and a random sample of current cat-owning households in the same community (control households). RESULTS: Potentially modifiable risk factors with the highest population attributable risk for relinquishment were owners having specific expectations about the cat's role in the household, allowing the cat outdoors, owning a sexually intact cat, never having read a book about cat behavior, cats having daily or weekly inappropriate elimination, and inappropriate care expectations. Frequency of inappropriate elimination and aggression toward people were not associated with declaw status, but these behaviors were more common among sexually intact cats, compared with sterilized cats. Owners of cats in case households were more likely than owners in control households to cite cost of sterilization as a reason a cat was sexually intact. Cats found as strays and cats acquired with minimal planning were at decreased risk of relinquishment. CLINICAL IMPLICATIONS: The identified risk factors can be modified by cat owners and veterinarians to decrease the estimated 4 million cats euthanatized annually in animal shelters. Owner education programs are needed as well as increased awareness on the part of cat owners and veterinarians of the importance of resolving feline inappropriate elimination problems.

Age Factors↗
PubMed1990

Autonomic reactivity and personality.

In 28 male and 42 female college students, rs between scores for Psychoticism, Neuroticism, Extraversion, and Lying from the Eysenck Personality Inventory and a measure of sympathetic dominance were of low magnitude, failing to support Eysenck's hypothesis that neuroticism is associated with imbalance in the autonomic nervous system.

Adult↗
PubMedDate not supplied

Spiral CT evaluation of coronary artery bypass graft patency.

Spiral CT (SCT) differs from conventional CT in that the entire heart can be rapidly imaged in the axial plane following the peripheral infusion of small quantities of contrast material. As contrast material travels through coronary artery bypass graft segments, good image detail is achieved, allowing visualization of entire coronary artery graft segments during a single injection. The patency of 43 coronary artery bypass grafts in 14 patients on contrast enhanced SCT, with timing tailored to patient-specific transit times, was compared with that obtained by selective graft angiography. With use of 5 or 8 mm/s table feed and 24 s volumetric acquisitions, SCT established graft patency with 85.7% sensitivity and 100% specificity compared to angiographic examination (96.4% sensitivity and 100% specificity). The mean time between angiography and SCT was 2.1 days, with 86% of SCT studies done within 24 h after angiography. The utilization of dynamic scanning to establish the patient-specific time delay prior to initiation of SCT proved crucial in improving the quality and reliability of SCT bypass graft patency assessment. The paired McNemar test indicates no significant difference between angiography and SCT in establishing patency rates.

Aged↗