Biomedical subjects
J Kaye
Publications and source records attributed to J Kaye.
Anatomical and physiological simulation for respiratory mechanics.
Injuries in trauma affect anatomical structures, indirectly affecting physiological systems through mechanical behavior and physical proximity. This paper describes the theory for and preliminary results from our approach to couple a three-dimensional (3-D) anatomical model of the chest with a physiological model of respiratory mechanics. In particular, we investigated behavior in quiet, normal breathing and in an open, sucking chest wound. We envision that our integrated simulation of respiratory anatomy and respiratory mechanics could assist students in visualizing and predicting relationships between structural-anatomical and functional-physiological changes in an interactive, 3-D environment.
Contrast between class I and class II MHC-mediated differentiation of a CD4+CD8+ T cell line: implications for lineage commitment.
Experiments in transgenic mice have demonstrated that thymocyte differentiation into the mature CD4+ helper or CD8+ cytotoxic T cell lineage is ultimately dependent upon the specificity of the TCR for class II or class I MHC molecules respectively. However, the initial mechanistic events involved in this process remain unclear. To address this issue, we have expressed a TCR specific for an ovalbumin peptide and the Kb class I MHC molecule in the DPK CD4+CD8+ precursor T cell line. This cell line originally expressed a TCR specific for a pigeon cytochrome c peptide and class II MHC molecules and has been shown previously to differentiate into CD4+CD8- cells upon recognition of antigen in vitro or thymic epithelial cells in vivo. Surprisingly, we find that recognition of either class I or class II MHC by these cells initiates differentiation into the CD4+ lineage and induces down-regulation of recombination associated genes. Unlike recognition of class II MHC, however, recognition of class I MHC does not induce full maturation. These results support a model in which (i) commitment to the CD4 lineage occurs prior to positive selection and (ii) CD4 lineage commitment is associated with a requirement for activation by a class II MHC-specific TCR in order to complete differentiation.
Genetic anticipation in Parkinson's disease.
We studied age at onset and family history of 137 patients (probands) with the diagnosis of idiopathic Parkinson's disease (PD). Probands (N = 21) who had an affected parent, aunt, or uncle were younger (p = 0.0001) at the onset of PD (47.7 +/- 8.8 years) than were probands (N = 11) who had an affected sib only (60.3 +/- 12.9 years) and probands (N = 105) who had no affected sib, parent, aunt, or uncle (59.2 +/- 11.4 years). Age at onset of affected family members differed significantly between generations (p = 0.0001). Age at onset was earlier, by an average of 17 years, in the proband generation than in the parental generation. The intrafamily variation in the calendar year of onset was too great to suggest a common point of exposure. Our data are most compatible with genetic anticipation, which could suggest involvement of an unstable trinucleotide repeat.
Generating penetration path hypotheses for decision support in multiple trauma.
We present a 3D graphical system that allows users to visualize different penetration path hypotheses for (multiple) gunshot or stab wounds, using a 3D graphical model of a human body with appropriate anatomical structures. The system also identifies the anatomical structures associated with each hypothesis. The various penetration path hypotheses follow from a combinatorial analysis of the set of surface wounds. The affected structures are determined by performing a detailed interpenetration analysis between 3D models of a penetration path and each anatomical structure within the body.
Modeling respiratory anatomy and physiology in VR.
In trauma, many injuries impact anatomical structures, which may in turn affect physiological processes--not only those processes within the structures, but ones occurring in physical proximity to them as well. Our goal is to endow a 3D anatomical model with physiological mechanisms to demonstrate such effects. Our approach couples deformable object simulation for organs with physiological modeling, in a way that supports three-dimensional animated simulation. We demonstrate our approach through our current model of respiratory mechanics in a virtual 3D environment. Anatomical models that can capture physiological and pathophysiological changes can serve as an infrastructure for more detailed modeling, as well as benefiting surgical planning, surgical training, and general medical education.
Quantitative analysis of hand radiographs in rheumatoid arthritis: time course of radiographic changes, relation to joint examination measures, and comparison of different scoring methods.
Quantitative studies of hand radiographs in patients with rheumatoid arthritis (RA) indicate that radiographic joint space narrowing and erosion are seen in more than 67% of patients within the 1st 2 years of disease, and progresses most rapidly during the 1st 5 years of disease, according to currently used scoring methods. Radiographic malalignment is rarely seen until after 5 years of disease. In cross sectional studies, correlations of radiographic scores with physical examination scores are minimally significant for joint tenderness, modestly significant for joint swelling, and highly significant for joint deformity and limited motion. In cross sectional studies, 3 quantitative methods, the Steinbrocker radiographic stage, modified Sharp method, and Larsen method, are highly significantly correlated and yield similar results in comparisons with other clinical measures.
T cells and suppression in vitro.
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Discrimination between thymic epithelial cells and peripheral antigen-presenting cells in the induction of immature T cell differentiation.
During their intrathymic migration, immature CD4+ CD8+ thymocytes that express a TCR able to recognize the expressed MHC molecules are positively selected, i.e., complete their differentiation program and become mature T cells. Using the immature CD4+CD8+ T cell line DPK, which can be induced to differentiate in culture, we show here that a subset of isolated thymic epithelial cells, but not peripheral antigen-presenting cells, can induce differentiation, suggesting a unique function of these cells in T cell development. In addition, analysis of activation markers induced by thymic epithelial cells versus specific antigen gives the first direct evidence that positive selection is associated with low level cell activation. In contrast with strict affinity-avidity models of thymic selection, we propose that a specialized antigen-presenting cell environment is an essential contributor to TCR-mediated differentiation in the thymus.
Changes in students' attitudes following a course on death and dying: a controlled comparison.
This study evaluated the effect of a death-education course on the death-related anxiety and attitudes toward death of 71 medical students not yet exposed to clinical rotations and four health care professionals. The Collect-Lester Fear of Death Scale and a semantic differential technique measuring attitudes toward the dying patient and his or her family were administered to course attendees before and after the course and to freshman students not taking the course. The 75 course attendees and the 93 controls completed the baseline measures, and 71 course attendees and 46 controls responded to the post-course evaluation. The course did not produce significant changes on the four Collett-Lester subscales, although there was an overall decline in anxiety when the two groups were combined (p = 0.035). Semantic differential scales showed no change for controls but a marked improvement in attitudes toward "treating the dying patient" and "dealing with the dying patient's family" for attendees (p < 0.001 for both). In summary, course participation resulted in improvement in students' attitudes toward dealing with death.
Cancer associated human papillomaviruses: perinatal transmission and persistence.
OBJECTIVE: To demonstrate the perinatal transmission and persistence of the cancer associated human papillomavirus types 16, 18, 31 and 33. DESIGN: Cervical swabs were taken from pregnant women between 20 and 38 weeks of gestation. Buccal and genital swabs were taken from infants at 24 h and at six weeks after delivery and examined for HPV-16, -18, -31 and -33 DNA by the polymerase chain reaction. SETTING: Maternity Unit at St Thomas's Hospital, London. SUBJECTS: Thirty-one pregnant women, 16 with a previous history of cervical intraepithelial neoplasia or genital warts, or both, and their 32 infants (one set of twins). RESULTS: Twenty of the 31 (65%) women were positive for HPV-DNA prior to delivery. Twelve of 32 (38%) and eight of 31 (26%) infants were HPV-DNA positive at 24 h and six weeks respectively. Swabs taken at 24 h demonstrated HPV type 16 in five mother-infant pairs and HPV type 18 in two mother-infant pairs. Dual infections with HPV types 16 and 18 were demonstrated in swabs from three mother-infant pairs. At six weeks, HPV-16 was demonstrated in swabs from six infants and HPV-18 in swabs from two infants. CONCLUSIONS: Perinatal transmission of human papillomavirus types 16 and 18 occurred in 55% cases. Persistent human papillomavirus infection was demonstrated at six weeks of age. Whether acquisition of human papillomavirus during the perinatal period predisposes to an increased risk of cervical intraepithelial neoplasia among female infants in later life remains to be established. Information on the persistence of perinatally acquired human papillomavirus is required before rational vaccination programmes can be considered.
Spirituality among caregivers.
The spiritual perspectives of 17 caregiver wives of dementia victims and 23 noncaregiving wives of healthy adults were compared in a pilot study using a convenience sample. Caregiver wives used symbols such as God, and spiritual behaviors such as prayer and forgiveness as coping mechanisms. Caregivers tended to share the problems and joys of living according to their spiritual belief more often than the noncaregiver wives of healthy adults. Caregivers also engaged in private prayer and sought spiritual guidance in making decisions in their everyday life more often. The findings suggest that nursing interventions with churches as a natural network for caregivers may be useful. Prayer, forgiveness, and spiritual reading materials are resources that may be helpful to some caregivers.
The relationship between spiritual perspective, social support, and depression in caregiving and noncaregiving wives.
The purpose of this study was to compare the relationships between spiritual perspective, social support, and depression in two groups of adults: caregiving wives of dementia victims and noncaregiving wives of healthy adults. Hypotheses predicted that increased spiritual perspective would be associated with increased social support and decreased depression in caregiving wives. Hypotheses also predicted that spiritual perspective would be more strongly associated with these variables in caregiving wives. Spiritual perspective was not significantly related to social support or depression in the caregivers. The relationships between these variables, however, were noted to be stronger in caregiving wives than in noncaregivers. Employment and increased availability of support were associated with decreased depression in caregivers.
Sexual harassment of critical care nurses: a costly workplace issue.
BACKGROUND: Sexual harassment in the workplace is a prevalent form of impermissible sex discrimination in employment. The high profile of this issue in the media, together with laws prohibiting sexual harassment, have not prevented this problem for working nurses. OBJECTIVES: To describe and determine the extent of sexual harassment incidents experienced by nurses working in critical care areas, and to determine attitudes about, and presence of policies regarding, sexual harassment in hospitals. METHODS: For this descriptive study the federal government's definition of sexual harassment and a list of sexually harassing behaviors was mailed with a survey to 188 critical care nurses. RESULTS: Findings indicated that 46% of the respondents had been harassed. Offensive sexual remarks (56%), unwanted physical contact (53%), unwanted nonverbal attention (27%), requests for dates (16%), and sexual propositions (9%) were types of sexual harassment experienced. Sexual assault was experienced by one woman. Harassers were physicians (82%), coworkers (20%), or immediate supervisors (7%). A majority of the incidents (69%) were not reported. Most nurses (80%) had not received training, nor were there policies and procedures to follow in most cases for reporting harassment. CONCLUSIONS: These results suggest that many critical care nurses are harassed and that relatively few hospitals have sexual harassment policies known to employees. They also indicate that sexual harassment training, policies, and procedures are needed to provide a safe, healthy work environment for critical care nurses.
On-line decision support for emergency trauma management.
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Evidence for familial factors that protect against dementia and outweigh the effect of increasing age.
A positive family history is associated with increased risk for dementia. It is not known whether a negative family history with long-lived relatives predicts a reduced risk for dementia. We studied the survival rate and the occurrence of dementia in 232 parents and siblings of 43 optimally healthy individuals > or = 84 years of age and compared them with 233 parents and siblings of 51 random controls and 499 parents and siblings of 88 Alzheimer disease (AD) patients. Prevalence of dementia after age 60 years was .031 for the relatives of healthy elderly, .066 for the relatives of random controls, and .217 for the relatives of AD patients. The cumulative incidence of dementia by age 85 years was estimated as .041 (+/- .019) for the relatives of healthy elderly individuals, .102 (+/- .038) for the relatives of random controls, and .360 (+/- .037) for the relatives of AD patients. Hazard-ratio estimates suggest that the risk of dementia for the relatives of healthy elderly is 3 times lower than the risk for the relatives of random controls (P < .03) and is 11 times lower than the risk for the relatives of AD patients (P < .00005). An analysis of age at death indicated that the relatives of healthy elderly and the relatives of AD patients had a longer life span than did the relatives of random controls.(ABSTRACT TRUNCATED AT 250 WORDS)
Apolipoprotein E genotype and Alzheimer's disease.
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Differentiation of an immature T cell line: a model of thymic positive selection.
Thymocyte differentiation is dependent upon recognition of major histocompatibility complex (MHC) molecules on thymic stroma, a process called positive selection. Here we describe an immature CD4+8+ T cell line derived from a TCR transgenic mouse that differentiates into CD4+8- cells in response to antigen and nonthymic antigen-presenting cells. When injected intrathymically, these cells differentiate in the absence of antigen. The ability of immature T cells to recognize MHC molecules in the absence of foreign antigen in the thymus can thus be attributed to a unique property of thymic antigen-presenting cells. These studies also demonstrate the phenotypic and functional changes associated with TCR-mediated T cell maturation and establish an in vitro model system of positive selection.