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Biomedical subjects

S Wilson

Publications and source records attributed to S Wilson.

At least 271 records · Page 15Linked to original sources
PubMed1997

Quantitating fetomaternal hemorrhages of D+ red cells using an FITC-conjugated IgG monoclonal anti-D by flow cytometry: a case report.

Several methods for quantitating fetomaternal hemorrhages (FMHs) have been described; these include the Kleihauer-Betke and red cell rosetting tests, and flow cytometry that uses an indirect antiglobulin technique, employing either FITC-conjugated IgG/unlabeled anti-D or streptavidin conjugates with biotinylated anti-D to enumerate D+ red cells in maternal blood. We have used a recently described directly conjugated FITC anti-D for direct flow cytometric (direct FC) quantitation of FMH in a patient who presented with a large fetal bleed (approx. 80 mL) as determined using the Kleihauer method. We compared the efficacy of the direct FC technique to the rosetting and Kleihauer tests in estimating the quantity of Rh immunoglobulin (RhIg) to be administered to the mother to suppress Rh alloimmunization. Both the Kleihauer and the direct FC gave precise estimates of 80 mL for the size of bleed, whereas the rosetting test failed to be as precise. The former tests predicted that a 10,000 iu dose (2,000 microg) of RhIg would be adequate; the lack of alloanti-D in a maternal follow-up sample obtained 9 months after delivery supported this prediction and underlined the reliability of the direct FC method as an alternative to the Kleihauer method for quantitating large FMHs.

Journal Article↗
PubMed1997

Health beliefs of blue collar workers. Increasing self efficacy and removing barriers.

The study compared the health beliefs of participants and non-participants in a blood pressure and cholesterol screening held at the worksite. A cross sectional, ex-post facto design was used. Questionnaires measuring health beliefs related to cardiac screening and prevention of cardiac problems were distributed to a convenience sample of 200 blue-collar workers in a large manufacturing plant in the Midwest. One hundred fifty-one (75.5%) completed questionnaires were returned, of which 45 had participated in cardiac worksite screening in the past month. A multivariate analysis of variance was used to analyze data. Participants perceived significantly fewer barriers to cardiac screening and scored significantly higher on self efficacy than non-participants. These findings concur with other studies identifying barriers and self efficacy as important predictors of health behavior. Occupational health nurses' efforts are warranted to reduce barriers and improve self efficacy by advertising screenings, scheduling them at convenient times and locations, assuring privacy, and keeping time inconvenience to a minimum.

Adult↗
PubMed1997

LTR retrotransposons and the evolution of eukaryotic enhancers.

Since LTR retrotransposons and retroviruses are especially prone to regional duplications and recombination events, these viral-like systems may be especially conducive to the evolution of closely spaced combinatorial regulatory motifs. Using the Drosophila copia LTR retrotransposon as a model, we show that a regulatory region contained within the element's untranslated leader region (ULR) consists of multiple copies of an 8 bp motif (TTGTGAAA) with similarity to the core sequence of the SV40 enhancer. Naturally occurring variation in the number of these motifs is correlated with the enhancer strength of the ULR. Our results indicate that inter-element selection may favor the evolution of more active enhancers within permissive genetic backgrounds. We propose that LTR retroelements and perhaps other retrotransposons constitute drive mechanisms for the evolution of eukaryotic enhancers which can be subsequently distributed throughout host genomes to play a role in regulatory evolution.

Animals↗
PubMed1997

A review of near patient testing in primary care.

AIMS AND OBJECTIVES: The aim was to identify publications relating to near patient testing (NPT), the use of alternative delivery systems between laboratory and general practice, including electronic data interchange (EDI), and computerised diagnostic decision support (CDDS), in the primary care setting to answer the following questions. What is the availability of NPT for primary care? What evidence is available to support the clinical effectiveness of NPT? What evidence is available on the accuracy and reliability of NPT within primary care? What evidence is available on the cost-effectiveness of different NPTs? How may CDDS improve the effectiveness of NPT? What evidence is available that compares NPT and existing laboratory services? What evidence is available on the cost-effectiveness of EDI or alternative delivery systems? HOW THE RESEARCH WAS CONDUCTED: Eight databases were searched, and the bibliographies from relevant publications checked for completeness. Unpublished work and publications not included in the databases were obtained by personal contact with collaborators, and from a postal survey sent to heads of academic departments of general practice and clinical chemistry and to researchers active or interested in the field worldwide. Questionnaires were also sent to 150 commercial organisations. Publications that met agreed definitions and reported original data were included in the systematic review. Of the 1057 publications identified, 102 (92 related to NPT, eight to CDDS, and two to EDI) were passed to the reviewers for appraisal of validity. The limited amount of published research relating to any particular NPT prohibited meta-analysis. Scoring systems to assess the validity of evaluations were also difficult to apply. RESEARCH FINDINGS: A wide variety of NPT systems have been developed. In general, the quality of the methods reported in the literature was poor. The issue of patient convenience and acceptability has not been adequately addressed. No evaluations of alternative delivery systems met the review criteria. No studies have evaluated the telephone or fax machine as a means of reporting results. For EDI, the majority of papers were descriptive. EDI and alternative delivery systems are not a replacement for NPT when the provision of an immediate result might have an impact on the quality of care. EDI may have clinical and cost advantages over traditional means of communication, but this has not been evaluated. The advisory role of the laboratory can be supported by CDDS. The use of CDDS and NPT has not, however, been fully evaluated. Few economic analyses have been conducted, and most were simple cost analyses. There are insufficient data for conclusions to be drawn on the cost-effectiveness of NPT in primary care. RECOMMENDATIONS: FURTHER SYSTEMATIC REVIEWS: Subject-specific systematic reviews are required that include laboratory and secondary care studies, and consider the potential for altering current management and patient acceptability. Priority topics include: biochemistry profiles on desktop analysers; cholesterol testing; urinalysis for the diagnosis of urinary tract infection; anticoagulation control; NPTs for the identification of acute infection. (ABSTRACT TRUNCATED)

Cost-Benefit Analysis↗
PubMed1997

The comforting interaction: developing a model of nurse-patient relationship.

In this article we argue that the separate literatures on the nurse-patient interaction and the nurse-patient relationship artificially fragment a unified process, and a model incorporating both interaction and relationship is critically needed. The Comforting Interaction-Relationship Model, in which the nurse-patient interaction is proposed as a means for the nurse and the patient to negotiate and establish a desired therapeutic relationship is presented. Nursing actions are described as three interrelated levels: 1) comforting strategies, or separate discrete actions which together form nurses' styles of care, 2) styles of care, or sets of comforting strategies, and 3) patterns of relating, or normative, professional behaviors. These three processes are provided in response to patient signals of distress, indices of discomfort, and patterns of relating that form patient actions. It is through this interaction of nursing actions and patient actions that the nurse-patient relationship is negotiated. This model is patient-led, dynamic, interactive, and context dependent. Even though the model is driven by the patient's behavioral state, actions, and reactions, both the nurse and the patient maintain control--the nurse selects the strategy or style to be used, and the patient, in negotiating, relinquishing, and accepting care, maintains control. Suggestions for future research are presented.

Disease↗
PubMed1996

Cardiac Na+ pump current-voltage relationships at various transmembrane gradients of the pumped cations.

Thermodynamic considerations predict changes of the Na+ pump current (Ip)-voltage (V) relationship of animal cells upon variations of the electrochemical gradients against which cations must be pumped. Experimental data in support of the predictions are sparse. Therefore, the effect on the Ip-V relationship of various electrochemical gradients for pumped Na+ and Cs+ was studied at constant deltaGATP (approximately -39kJ/mol in cardioballs from sheep Purkinje fibres. Control of the subsarcolemmal ionic concentrations during whole-cell recording was ensured by activation of Ip below its half maximal activity or by measuring the initial Ip following reactivation of the Na+/K+ pump. With gradients close to physiological conditions Ip was outward over the entire voltage range and the Ip-V relationship showed a maximum near zero potential. Steepening the ionic gradients diminished the Ip amplitude and outward pump current was no longer detectable between -65 mV and -110 mV. Flattened ionic gradients increased the Ip amplitude and shifted apparently the reversal potential Erev to more negative values. These changes are in line with theoretical considerations. The measured Ip-V relationships were fitted by curves computed on the basis of a simplified Post-Albers scheme of Na+/Cs+ pumping. The increased Ip amplitude at flat ionic gradients was due to a decrease of [Cs+]o for half maximal Ip activation. The maximal Ip amplitude remained unaffected

Animals↗
PubMed1996

Gap-junction disassembly and connexin 43 dephosphorylation induced by 18 beta-glycyrrhetinic acid.

Gap-junction channels connect the interiors of adjacent cells and can be arranged into aggregates or plaques consisting of hundreds to thousands of channel particles. The mechanism of channel aggregation into plaques and whether plaques can disaggregate are not known. Many carcinogenic and tumor-promoting chemicals have been identified that inhibit cell-cell gap-junctional coupling. Here, we provide morphological evidence that 18 beta-glycyrrhetinic acid (18 beta-GA), a saponin isolated from licorice root that is an inhibitor of gap-junctional communication, caused the disassembly of gap-junction plaques in WB-F344 rat liver epithelial cells. This effect was dose (5-40 microM) and time dependent (1-4 h treatment). Gap-junction channels in WB-F344 cells are comprised of connexin 43 (Cx43), and the protein is phosphorylated to a species known as Cx43-P2 coincident with the assembly of channels into plaques. Consistent with this, the disassembly of plaques induced by 18 beta-GA was correlated with decreases in Cx43-P2 levels and increases in nonphosphorylated Cx43. Biochemical evidence indicated that these changes in the P2 and NP forms of Cx43 represented 18 beta-GA-induced dephosphorylation of Cx43-P2 and not its degradation or the inhibition of Cx43-NP phosphorylation. Okadaic acid and calyculin A, which are inhibitors of type 1 and type 2A protein phosphatases, prevented the dephosphorylation of Cx43, suggesting that one or both of these phosphatases were involved in Cx43 dephosphorylation. These data indicate that 18 beta-GA causes type 1 or type 2A protein phosphatase-mediated Cx43 dephosphorylation coincident with the disassembly of gap-junction plaques.

Animals↗
PubMed1996

Memory for Relevant and Irrelevant Information: Evidence for Deficient Inhibitory Processes in Language/ Learning Disabled Children

The present study examined whether language/learning disabled children have greater difficulty than nondisabled children suppressing information that becomes irrelevant during a sentence processing and memory task. During study trials, children were asked to predict and remember the terminal nouns for a series of sentences that highly constrained a terminal noun. For half of the study trials (fillers) the child's prediction was confirmed by presenting the child with the expected ending (e.g., "Butterflies fly by flapping their . . . wings."). For the remaining study trials (critical trials), however, the sentence ending expected by the child was disconfirmed with a low-probability ending (target noun). Thus, when presented with the sentence, "We made a sandwich with peanut butter and . . . ," the child's prediction ("jelly") was disconfirmed with a different ending ("bananas"). Memory for the disconfirmed and target nouns of critical study trials were subsequently tested implicitly with a new sentence-completion task. In this case, memory for disconfirmed and target nouns that had been associated with individual study sentences were measured in terms of priming effects. The analysis of priming effects indicated that language/learning disabled children experienced greater difficulty than nondisabled children inhibiting the activation of irrelevant information (disconfirmed nouns) and sustaining the activation of relevant information (target nouns) during a verbal memory task. These results were discussed in terms of their implications for some of the memory and language difficulties of language/learning disabled children.

Journal Article↗
PubMed1996

Increased pituitary activation following metyrapone administration in post-traumatic stress disorder.

Our previous findings have demonstrated that individuals with post-traumatic stress disorder (PTSD) show lower basal cortisol levels, a larger number of lymphocyte glucocorticoid receptors, and an enhanced suppression of cortisol following the administration of dexamethasone compared to normals and patients with major depression. We have previously suggested that these alterations reflect an enhanced negative feedback inhibition of the hypothalamic-pituitary-adrenal (HPA) axis in PTSD. However, in the absence of direct knowledge of pituitary capability in this disorder, it has been equally likely that the alterations observed reflected either pituitary or adrenal insufficiency. In the present study, we examined ACTH release from the pituitary gland in PTSD following the administration of metyrapone. Metyrapone resulted in a significantly greater increase of ACTH and 11-deoxycortisol in combat veterans with PTSD (n = 11) compared with normal male volunteers (n = 8). When seen in the context of other abnormalities observed in PTSD, the present demonstration of increased pituitary activity in the absence of negative feedback provides unequivocal support for the hypothesis of enhanced negative feedback.

Adrenocorticotropic Hormone↗
PubMed1996

Human papillomavirus infection and risk of progression of epithelial abnormalities of the cervix.

The polymerase chain reaction has been used to determine the presence of human papillomavirus (HPV) 16 and HPV 18 DNA sequences in archival histological material removed from a cohort of untreated women with cervical epithelial abnormalities. The detection of HPV 16 or HPV 18 DNA sequences in the initial biopsy specimen was associated with a significantly increased risk of subsequent disease progression.

Cervix Uteri↗