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Biomedical subjects

S Brown

Publications and source records attributed to S Brown.

At least 127 records · Page 7Linked to original sources

Home healthcare and client outcomes.

This study examined the outcome measures of readmission to the hospital and change in functional status/quality of life. Patients were admitted to the hospital most commonly by the 15th visit indicating complications arise soon after home care initiation. Implications for more specific data related to acuity, family support, and outcomes are suggested to develop and evaluate strategies for cost-effective care. The potential for preventing hospitalizations may be diminished due to the cost containment strategies currently used by agencies in response to PPS.

Activities of Daily Living↗

Are African-American nuclear workers at lower mortality risk than Caucasians?

This study investigated disparities in worker mortality across race at the Savannah River site (SRS) nuclear facility in Aiken, South Carolina. Standardized mortality ratios were calculated stratified by race (Caucasian, African-American) and gender for specific causes of death, and by race, gender, duration of employment, and follow-up for overall mortality. Race-specific standardized mortality ratios for African-American male workers generally were lower than those for Caucasian male workers, although both groups showed strong healthy worker effects. Nevertheless, African-American male workers generally had higher absolute mortality rates. Understanding why SRS African-American male workers are substantially healthier than their reference population as compared with Caucasian male workers but are less healthy in absolute terms than the SRS Caucasian male workers may provide clues for prevention or intervention. Further, the standardized mortality ratios at the SRS were lower than at the Hanford and Oak Ridge nuclear facilities, which warrants investigation.

Adult↗

Expression and stability of Arabidopsis CDC6 are associated with endoreplication.

Studies on the CDC6 protein, which is crucial to the control of DNA replication in yeast and animal cells, are lacking in plants. We have isolated an Arabidopsis cDNA encoding the AtCDC6 protein and studied its possible connection to the occurrence of developmentally regulated endoreplication cycles. The AtCDC6 gene is expressed maximally in early S-phase, and its promoter contains an E2F consensus site that mediates the binding of a plant E2F/DP complex. Transgenic plants carrying an AtCDC6 promoter-beta-glucuronidase fusion revealed that it is active in proliferating cells and, interestingly, in endoreplicating cells. In particular, the extra endoreplication cycle that occurs in dark-grown hypocotyl cells is associated with upregulation of the AtCDC6 gene. This was corroborated using ctr1 Arabidopsis mutants altered in their endoreplication pattern. The ectopic expression of AtCDC6 in transgenic plants induced endoreplication and produced a change in the somatic ploidy level. AtCDC6 was degraded in a ubiquitin- and proteosome-dependent manner by extracts from proliferating cells, but it was degraded poorly by extracts from dark-grown hypocotyl endoreplicating cells. Our results indicate that endoreplication is associated with expression of the AtCDC6 gene and, most likely, the stability of its product; it also apparently requires activation of the retinoblastoma/E2F/DP pathway. These conclusions may apply to endoreplicating cells in other tissues of the plant and to endoreplicating cells in other eukaryotes.

Amino Acid Sequence↗

Team midwife care: maternal and infant outcomes.

The aim of this study was to add additional information on intervention rates and maternal and infant outcomes of team midwife care to previous reports which have suggested this model of care can be associated with a reduction in medical interventions during labour and birth with no statistically significant influence on maternal and infant outcomes. The study was designed as a randomised controlled trial, with 495 women randomised to team midwife care being compared to 505 women randomsed to standard care. The study revealed no statistical differences between team midwife care and standard care in medical interventions, maternal health and infant health. These findings suggest that team midwifery as it is practised in this study is a safe alternative for women.

Delivery, Obstetric↗

Resolution of viable and membrane-compromised bacteria in freshwater and marine waters based on analytical flow cytometry and nucleic acid double staining.

The membrane integrity of a cell is a well-accepted criterion for characterizing viable (active or inactive) cells and distinguishing them from damaged and membrane-compromised cells. This information is of major importance in studies of the function of microbial assemblages in natural environments, in order to assign bulk activities measured by various methods to the very active cells that are effectively responsible for the observations. To achieve this task for bacteria in freshwater and marine waters, we propose a nucleic acid double-staining assay based on analytical flow cytometry, which allows us to distinguish viable from damaged and membrane-compromised bacteria and to sort out noise and detritus. This method is derived from the work of S. Barbesti et al. (Cytometry 40:214-218, 2000) which was conducted on cultured bacteria. The principle of this approach is to use simultaneously a permeant (SYBR Green; Molecular Probes) and an impermeant (propidium iodide) probe and to take advantage of the energy transfer which occurs between them when both probes are staining nucleic acids. A full quenching of the permeant probe fluorescence by the impermeant probe will point to cells with a compromised membrane, a partial quenching will indicate cells with a slightly damaged membrane, and a lack of quenching will characterize intact membrane cells identified as viable. In the present study, this approach has been adapted to bacteria in freshwater and marine waters of the Mediterranean region. It is fast and easy to use and shows that a large fraction of bacteria with low DNA content can be composed of viable cells. Admittedly, limitations stem from the unknown behavior of unidentified species present in natural environments which may depart from the established permeability properties with respect to the fluorescing dyes.

Bacteria↗

Role of genetic resistance in invasive pneumococcal infection: identification and study of susceptibility and resistance in inbred mouse strains.

From a panel of nine inbred mice strains intranasally infected with Streptococcus pneumoniae type 2 strain, BALB/c mice were resistant and CBA/Ca and SJL mice were susceptible to infection. Further investigation revealed that BALB/c mice were able to prevent proliferation of pneumococci in the lungs and blood, whereas CBA/Ca mice showed no bacterial clearance. Rapidly increasing numbers of bacteria in the blood was a feature of CBA/Ca but not BALB/c mice. In the lungs, BALB/c mice recruited significantly more neutrophils than CBA/Ca mice at 12 and 24 h postinfection. Inflammatory lesions in BALB/c mice were visible much earlier than in CBA/Ca mice, and there was a greater cellular infiltration into the lung tissue of BALB/c mice at the earlier time points. Our data suggest that resistance or susceptibility to intranasal pneumococci may have an association with recruitment and/or function of neutrophils.

Animals↗

How many chaplains per 100 inpatients? Benchmarks of health care chaplaincy departments.

Reports the results of a questionnaire survey of a sample of chaplaincy departments directors (N = 370) designed to answer the following questions: How many chaplains do various types of hospitals employ per 100 inpatients? What is the relationship between the number of employed chaplains and departmental Clinical Pastoral Education (CPE) programs? How much effort do departments give to outpatient ministry? What percentage of ministry do volunteer chaplains provide? Provides tentative answers to inform the strategic planning processes of chaplains and administrators.

Benchmarking↗

A common regulatory locus affects both HNF4/HNF1alpha pathway activation and sensitivity to LPS-mediated apoptosis in rat hepatoma cells.

Lipopolysaccharide (LPS) has been shown to protect certain cultured mammalian cells from undergoing programmed cell death (apoptosis) when exposed to tumor necrosis factor (TNF). However, LPS has also been reported to induce apoptosis in cultured endothelial cells, suggesting that apoptotic response mechanisms may be dependent upon cell type. In order to understand the influence of tissue-specific gene expression on apoptosis, we compared LPS-induced apoptosis in hepatoma cells with dedifferentiated hepatoma variant cells that have been selected for the loss of the liver-enriched HNF4/HNF1alpha transcriptional activation pathway. We report here that while human, rat and mouse hepatoma cell lines are resistant to LPS-mediated cell death, the HNF4-/HNF1alpha- rat hepatoma variant cells undergo rapid apoptosis (as determined by morphological analysis, DNA laddering and the TUNEL assay) upon exposure to LPS. Genetic rescue experiments show that restoration of the HNF4/HNF1alpha pathway via chromosome transfer render the hepatoma variant cells resistant to LPS-mediated apoptosis. However, the introduction of HNF1alpha alone failed to alter the apoptotic phenotype, suggesting that the defect(s) in the hepatoma variant cells that influence apoptotic responses lies upstream of HNF4/HNF1alpha expression. This study provides for the first time direct evidence of a common regulatory locus involved in activation of hepatic gene expression and sensitivity to LPS-mediated apoptosis.

Animals↗

Delirium in the terminally-ill cancer patient: aetiology, symptoms and management.

Delirium is a frequent and serious clinical problem in the terminally ill cancer patient. Multiple dimensions of delirium make definition, measurement, and assessment of it challenging in clinical nursing practice. Assessment and management of delirium requires knowledge of the diagnostic criteria for it, aetiology, signs and symptoms, and nursing interventions. Four delirium assessment scales determined to be useful in assessing patients with terminal illness are reviewed. The use of a delirium assessment instrument in routine nursing assessments would be important for the nurse's early detection of delirium so that interventions to reverse the causes of delirium could immediately be implemented.

Delirium↗

Assessment of adult stereopsis using the Lang 1 Stereotest: a pilot study.

BACKGROUND AND PURPOSE: To assess the use of the Lang 1 Stereotest as a vision-screening test for adults, for which little is known or reported. METHOD: The Lang 1 Stereotest was administered to 292 consecutive participants of the Visual Impairment Project (VIP) five year followup study, which is a population based study of eye disease in Melbourne, Australia. 56.9% were female. The mean age was 59.4 years, range 44-90 years. A "positive" stereoscopic response was recorded where the stereoscopic target image was correctly named; a "partial positive" response where depth was appreciated but the shape could not be named; and a "negative" response where there was no appreciation of a stereo effect. The responses were further categorized so that the test was either "passed" or "failed". A "pass" score was 3/3 positive responses; 3/3 partial positive responses or 2/3 positive and/or partial positive responses where the negative response was at the 550" of arc stereoacuity level. "Failure" was 3/3 negative responses and 2/3 negative responses where the positive or partial positive response as at the 1200" level. RESULTS: Of the 292 participants tested, 19 (6.5%) participants "failed" the test. In addition to strabismus and anisometropia, failure was associated significantly (p<0.001) with reduced distance visual acuity (<6/12) irrespective of the ocular morbidity. CONCLUSION: The Lang 1 Stereotest correctly identified people with vision defects associated with reduced stereopsis. This suggests the Lang 1 Stereotest is an appropriate for the vision screening of adults as it is for children.

Adult↗

Ethoxyresorufin-O-deethylase induction in trout exposed to mixtures of polycyclic aromatic hydrocarbons.

This study investigated whether ethoxyresorufin-O-deethylase (EROD) activity in rainbow trout exposed to mixtures of polycyclic aromatic hydrocarbons (PAHs) could be predicted from induction equivalency factors (IEF). The test PAHs were classified into strong and weak inducers on the basis of similar exposure-response curves. Induction equivalency factors of strong inducers, based on benzo[k]fluoranthene (BkF) as the reference compound, ranged from 0.03 to 0.16. Trout exposed to mixtures of strong inducers (2, 4, and 6 equipotent parts) at 0.32-, 1.0-, or 3.2-nM BkF-equivalents showed exposure-dependent increases in EROD activity, consistent with an additive interaction. The extent of activity did not vary greatly among mixtures and single PAHs at a given induction equivalent quantity (IEQ). Induction equivalency factors could not be calculated for weak inducers because the range of induction was too low. Hence, each weak inducer was added to mixtures at concentrations that induced EROD activity fivefold. These mixtures appeared additive because binary and quaternary mixtures caused about 10- and 20-fold induction, respectively. Strong inducers mixed the same way also showed additivity. In contrast, EROD induction by mixtures containing both strong and weak PAHs was 800 to 900% greater than expected, suggesting synergistic interactions. Therefore, if mixtures are composed of PAHs that behave similarly, IEFs may be a suitable approach for assessing risk. However, for mixtures that contain PAHs of differing potency and efficacy, bioassays will be a more reliable measure of risk than IEFs.

Animals↗

Nuclear DNA content and base composition in 28 taxa of Musa.

The nuclear DNA content of 28 taxa of Musa was assessed by flow cytometry, using line PxPC6 of Petunia hybrida as an internal standard. The 2C DNA value of Musa balbisiana (BB genome) was 1.16 pg, whereas Musa acuminata (AA genome) had an average 2C DNA value of 1.27 pg, with a difference of 11% between its subspecies. The two haploid (IC) genomes, A and B, comprising most of the edible bananas, are therefore of similar size, 0.63 pg (610 million bp) and 0.58 pg (560 million bp), respectively. The genome of diploid Musa is thus threefold that of Arabidopsis thaliana. The genome sizes in a set of triploid Musa cultivars or clones were quite different, with 2C DNA values ranging from 1.61 to 2.23 pg. Likewise, the genome sizes of tetraploid cultivars ranged from 1.94 to 2.37 pg (2C). Apparently, tetraploids (for instance, accession I.C.2) can have a genome size that falls within the range of triploid genome sizes, and vice versa (as in the case of accession Simili Radjah). The 2C values estimated for organs such as leaf, leaf sheath, rhizome, and flower were consistent, whereas root material gave atypical results, owing to browning. The genomic base composition of these Musa taxa had a median value of 40.8% GC (SD = 0.43%).

Algorithms↗

Humic acids enhanced removal of aromatic hydrocarbons from contaminated aquifers: developing a sustainable technology.

Contamination by gasoline and diesel fuels is a threat to groundwater resources. Polynuclear aromatic hydrocarbons (PAHs) which can represent up to 60% of volume in diesel fuels are of particular concern because many of them are carcinogenic and they are persistent, especially in oxygen-limited environment. Despite the development of alternative approaches, pump and treat continues to be the leading technology for the remediation of groundwater contaminated by gasoline and diesel fuels. The efficiency of this technology is however limited by the low solubility of the aromatic hydrocarbons. The objective of this study was to investigate the influence of humic acids on the removal of aromatic hydrocarbons from petroleum products in groundwater aquifers and to evaluate the potential use of humic acids, as a cost effective additive, in groundwater and soil remediation. In order to prove the feasibility of using humic acid in the field, a pilot scale experiment was conducted in a model aquifer with a very dense monitoring network, providing controlled conditions only possible in a semi-artificial system. In addition, different sources of humic acids were compared with surfactants for their ability to bind PAHs.

Chromatography, High Pressure Liquid↗

Consumer health informatics: a consensus description and commentary from American Medical Informatics Association members.

BACKGROUND: Although interest in Consumer Health Informatics (CHI) has increased, a consensus definition of CHI does not yet exist. PURPOSE: To conduct a hypothesis-generating survey of AMIA members regarding definition and research agenda for CHI. METHODS: We solicited participation among AMIA members in an Internet-based survey focusing on issues related to a definition of CHI. RESULTS: One hundred thirty-five AMIA members responded. Participants indicated a broad spectrum of topics important to CHI including "self-help for disease management" and "patient access to their own medical records." CHI research was felt to rely heavily on public health methods such as epidemiology and outcomes research, a paradigm shift from traditional medical informatics. Responses indicated a perceived lack of funding and need for further research in CHI. CONCLUSIONS: A working definition should emphasize the multidisciplinary nature of CHI, include consumer input into CHI design, and focus on public health approaches to evaluation.

Community Participation↗