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Biomedical subjects

M Horan

Publications and source records attributed to M Horan.

At least 37 records · Page 2Linked to original sources
PubMed1991

Monocyte responses to sulfatide from Mycobacterium tuberculosis: inhibition of priming for enhanced release of superoxide, associated with increased secretion of interleukin-1 and tumor necrosis factor alpha, and altered protein phosphorylation.

In monocytes, sulfatide, a lipid from Mycobacterium tuberculosis, blocked priming for enhanced release of superoxide (O2-) by the macrophage activating factors lipopolysaccharide, gamma interferon, interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha), and muramyl dipeptide. Sulfatide, in the presence of lipopolysaccharide, also caused increased secretion of IL-1 beta and TNF-alpha into monocyte culture medium. Sulfatide altered the pattern of phosphorylation of monocyte proteins. Cell lysates prepared from monocytes treated with sulfatide showed decreased activity of protein kinase C, but sulfatide did not directly inhibit protein kinase C activity when added to lysates. A known inhibitor of protein kinase C, staurosporine, also inhibited O2- release and caused increased secretion of IL-1 beta. Thus, sulfatide appeared to indirectly affect protein kinase C, implicating protein kinase C as part of the mechanism of priming. Because sulfatide blocked priming for enhanced release of O2-, which could interfere with monocyte bactericidal activity, while causing enhanced secretion of IL-1 beta and TNF-alpha, which could promote formation of granulomata, sulfatide might be an important factor in the pathogenesis of M. tuberculosis.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1990

Dipyridamole inhibits O2- release and expression of tissue factor activity by peripheral blood monocytes stimulated with lipopolysaccharide.

Monocytes can be induced to synthesize and express tissue factor procoagulant activity. They can also be stimulated to release a broad spectrum of inflammatory agents including superoxide anion (O2-) that are thought to contribute to the pathogenesis of inflammatory diseases. Dipyridamole, an inhibitor of platelet aggregation blocks the lipopolysaccharide (LPS)-induced increase in monocyte-associated tissue factor activity and phorbol myristate acetate (PMA) stimulated O2- release from monocytes and polymorphonuclear leukocytes (PMN). Dipyridamole inhibition of O2- release can be reversed by increased glucose in the culture media, whereas dipyridamole inhibition of tissue factor can not be reversed by increased glucose in the culture media. These results reveal that dipyridamole influences monocytes by at least two distinct mechanisms. Further, it may serve as an anti-thrombotic agent by virtue of its effect on both platelet aggregation and monocyte tissue factor activity.

Biological Transport↗
PubMed1988

Nurses' beliefs about cause and prevention of occupational back pain.

Nurses' beliefs and attitudes about causes and prevention of occupational back pain of nurses (OBPN) were studied by interviewing 68 nurses using a semi-structured format. Direct patient contact activities, particularly patient transfers, were most frequently mentioned as causes of OBPN. Attitudes and beliefs about preventive methods focused upon personal work practices and personal behavior such as choice of clothing and personal exercise. The findings of this study suggest that the causes of and preventive methods for OBPN identified by nurses differ from the actual work tasks performed and possibly associated with OBPN as determined by other studies. The authors postulate that nurse training and attitudes lead to a narrow focus; avoiding preconceived concepts is necessary for preventing OBPN.

Adult↗
PubMed1987

Epidemiologic considerations in defining hypertension.

Definitions of hypertension have historically been based on at least one of three concepts. The first approach identifies thresholds of hypertension based on the frequency of occurrence in the population. The statistical approach designates a point in the distribution (e.g., the 95th percentile), as the threshold for hypertension. This distribution method identifies different limits for hypertension depending on the age, sex, and race, of the population, all of which affect the average pressure. Although distribution curves do not by themselves identify thresholds for intervention, they are useful for examining changes in population groups over time. The second approach to defining hypertension relates pressures to the risk of morbidity and mortality and is characterized by a continuously graded curve with no clear categorical thresholds. Studies correlating both diastolic and systolic pressures with cardiovascular complications demonstrate continuous risks from lowest to highest values for both sexes, all ages, and both blacks and whites in the United States. The blood pressure-risk relationship provides a compelling rationale for treatment but does not by itself define thresholds for the initiation of therapy. The third approach uses data from clinical intervention trials to identify thresholds where the benefits of therapy outweigh the costs and side effects of long-term treatment. Although results of large randomized trials have clearly demonstrated reductions in morbidity and mortality by lowering blood pressures, consensus on the lowest threshold within the mild range for which antihypertensive drug treatment is recommended has not been reached. Because an optimal definition of hypertension must encompass all three approaches and the resultant classification scheme must be sufficient for all purposes, attempts to refine and improve upon the presently recommended thresholds will undoubtedly continue.

Age Factors↗
PubMed1987

Importance of non-patient transfer activities in nursing-related back pain: I. Questionnaire survey.

Work and personal factors associated with occupational back pain were investigated based upon responses to questionnaires administered to hospital nurses. Factor analysis of outcome measures developed two indices of occupational back pain: "pain factor" and "impact factor." Factor analysis also separated reported work activities into five groups. By logistic regression, frequency of "carrying and pushing" and "patient care activity" were associated with occupational back pain. These findings suggest that research and training should not focus on patient transfers only, but must emphasize nonpatient contact activities performed by nurses.

Back Pain↗
PubMed1986

[Detection, evaluation and treatment of arterial hypertension].

Hypertension, or high blood pressure, is a clinical disorder, which if left untreated, results in premature cardiovascular morbidity and mortality. Its prevalence in industrialized countries is of such a magnitude as to warrant its designation as a public health problem. There are documented efficacious interventions which when implemented, significantly reduce morbidity and mortality. It is, therefore, reasonable to establish guidelines for the detection, evaluation and treatment of high blood pressure so that susceptible population groups can have care for their hypertension provided in a standardized fashion.

Adolescent↗
PubMed1980

Using ECT to study hemispheric specialization for sequential processes.

Two studies are reported, citing the effects of unilateral versus bilateral electroconvulsive shock therapy on the performance of short cognitive tests. In Study 1, seven tets were administered before and after three treatment sessions. The most interesting finding was that performance improved significantly on the Knox Cube Imitation test following right unilateral shock. Study 2 replicated this unexpected finding. These results were interpreted as demonstrating that the left cerebral hemisphere is specialized for the processing of sequential time-dependent information.

Adult↗
PubMed1977

A method for producing synchronized audio signals.

An examination of the work dealing with dichotic listening reveals that technical problems prevent clear interpretation of the data. One of the most crucial problems is that of achieving simultaneity of output so that dichotic (simultaneous but different) material is introduced into the auditory system. A simple method for achieving such synchrony on stereotape is described together with a method for testing for degree of simultaneity, if possible.

Acoustic Stimulation↗
PubMedDate not supplied

How tutors assist adults with learning disabilities to use virtual environments.

PURPOSE: To describe strategies used by tutors teaching adults with learning disabilities to use desktop virtual environments and to investigate their effectiveness by examining changes over time in tutor and learner behaviour. METHOD: Twenty adults with learning disabilities spent 12 sessions with one of four non-disabled tutors learning to use desktop virtual environments designed to teach independent living skills. Sessions were recorded on videotape, categories of behaviour were described and tapes analysed for frequency of tutor behaviours and goals achieved by learners. RESULTS: Tutor strategies were described in terms of whether they aimed to help the learner master the interaction devices or to navigate and achieve goals in the virtual environments and how directive they were. There were some differences between tutors but this did not relate to whether tutors were experienced users themselves of the environments or were initially unfamiliar with them. Goal achievement was maintained at a constant level while help with the interaction devices and specific information about the environment decreased over repeated sessions. Rates of non-specific information did not change. CONCLUSIONS: Pretraining with the interaction devices would free both tutor and learner to concentrate on achieving goals in the environments. Much of the specific help given by the tutor could be incorporated into the software.

Adult↗
PubMedDate not supplied

Delusions induced by procaine penicillin: case report and review of the syndrome.

A patient manifesting an acute psychosis after receiving an injection of procaine penicillin is reported. The psychosis began immediately after drug administration and gradually abated over a forty-eight-hour period. The clinical presentation was dominated by paranoid delusions and a Capgras-like syndrome. Sixty-six previously reported cases were identified and reviewed. Patients manifested combinations of fear, auditory hallucinations, somatic hallucinations, visual hallucinations, and paranoid or religious delusions. The syndrome may occur with inadvertent intravenous injection of procaine and most likely reflects the action of procaine on limbic system structures.

Delusions↗
PubMedDate not supplied

Maternal employment effects on family and preterm infants at three months.

The purpose of this study was to investigate the effects of maternal employment status and the mother's degree of choice and satisfaction regarding her employment status on family functioning and on the preterm infant's development at three months chronologic age. Families with preterm infants (N = 110) were categorized as employed, nonemployed, and on leave of absence based on the mother's employment status at three months postpartum. There were no significant differences across employment groups on family functioning and child development. The infant's motor development was positively correlated with number of hours employed per week and degree of choice for the employed mother families, but negatively correlated with choice for the nonemployed mother families. These results suggest that maternal employment may not be detrimental for infants born prior to term. Indeed, it may be beneficial, especially if the mother has a choice in the matter.

Employment↗
PubMedDate not supplied

Data management issues in longitudinal research.

Much of the existing literature about the research process has neglected data management. While design, instrumentation, sampling, and analysis are important parts of the process, paying attention to the issues surrounding data management is crucial to the success of the study. Data entry and analysis are facilitated when the details of data structure and management are decided before data collection begins.

Database Management Systems↗