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Biomedical subjects

K McLaughlin

Publications and source records attributed to K McLaughlin.

At least 55 records · Page 3Linked to original sources
PubMed1995

Implicit and explicit memory bias in anxiety: a conceptual replication.

Williams, Watts, MacLeod and Mathews' (1988) [Cognitive psychology and the emotional disorders. Chichester, Wiley] model of anxiety and cognition leads to the prediction that anxious subjects will show an implicit, but not an explicit, memory advantage for threat-related information. Mathews, Mogg, May and Eysenck (1989) [Journal of Abnormal Psychology, 98, 401-407] obtained marginally significant support for this prediction in an experiment that tested memory using word stem completion tasks following a self-referent encoding procedure. However, neither the reliability nor generality of these findings have been established. The current experiment was designed to provide a conceptual replication of Mathews et al.'s study, using different tests of implicit memory (i.e. tachistoscopic identification) and explicit memory (i.e. recognition) and an alternative type of encoding task (i.e. colour naming stimulus words). 16 generalised anxiety disorder patients, and 16 non-anxious control subjects were tested. As predicted, the anxiety patients showed a relative implicit memory advantage for threat-related stimulus words, while the two subject groups did not differ in their pattern of explicit memory performance. These results support the predictions generated by Williams et al.'s model of anxiety and cognition.

Adult↗
PubMed1993

Binding activities of cis-platin-damage-recognition proteins in human tumour cell lines.

Proteins can be detected by South-western analyses of human tumour-cell extracts binding to double-stranded oligonucleotide DNA treated in vitro with the chemotherapeutic drug cis-diamminedichloroplatinum (II) (CDDP), but not to untreated DNA. The relative molecular masses of proteins binding to the CDDP-treated double-stranded oligonucleotide are 25, 48 and 97 kDa. The binding activity of 2 of the CDDP-damage-recognition proteins, of relative molecular mass 48 and 97 kDa, is greater in a CDDP-resistant human ovarian tumour cell line than in the parental sensitive line. South-western analysis of a panel of human bladder cell lines and CDDP-sensitive testicular cell lines show consistent patterns of CDDP-damage-recognition proteins within each cell type, however with differences between the 2 cell types. Binding of the proteins to CDDP-damaged DNA and the altered binding activity detected in tumour cell lines suggests that alteration in damage-recognition proteins could play a role in tumour response to CDDP.

Base Sequence↗
PubMed1993

Cisplatin-DNA damage recognition proteins in human tumour extracts.

Enhanced repair of DNA adducts may be a cause of cis-diamminedichloroplatinum(II) resistance in solid malignancies. Binding of specific damage recognition proteins to the sites of DNA damage may be involved in the initial steps of DNA repair, or alternatively may block access of repair proteins to damaged DNA. Proteins which bind specifically to CDDP-modified DNA were identified in cell extracts from human ovarian carcinoma cell lines by two assays, the gel mobility shift assay and the southwestern blot. In the first assay, proteins complexed with CDDP-modified oligonucleotide and produced two retarded bands, B1 and B2. The B2 complex was partially purified from an ovarian cell extract by anion exchange FPLC, and was shown to bind to DNA damaged by CDDP but not by transDDP or UV irradiation. Using the southwestern blot, proteins of 97, 48, and 25 kD were identified; each of these bound to CDDP-modified but not undamaged oligonucleotide. The partially purified B2 protein fraction contained both the 97 and the 25 kD damage recognition proteins. A human ovarian carcinoma cell line selected in vitro for CDDP-resistance (OV1P/DDP), which is 5-fold more resistant to CDDP than the parental line (OV1P), showed an increase in binding of the 97 and 48 kD damage recognition proteins compared with the parental line. Twelve ovarian cell lines differed by up to 3-fold in their expression of these proteins, but there was no correlation between the amount of damage recognition protein in a cell extract and the cellular sensitivity to CDDP. Damage recognition proteins were also demonstrated in extracts prepared from biopsies of human ovarian, cervical, and testicular malignancies, but there was no apparent difference in the binding activity in extracts from tumours of different CDDP-sensitivity. The functional role of these damage recognition proteins remains to be established.

Base Sequence↗
PubMed1992

Binding of human single-stranded DNA binding protein to DNA damaged by the anticancer drug cis-diamminedichloroplatinum (II).

The chemotherapeutic drug cis-diamminedichloroplatinum (II) covalently binds to DNA resulting in a variety of adducts and cross-links which are thought to be responsible for the toxicity of the drug. We have used the gel mobility shift assay to detect proteins which bind to DNA treated in vitro with cis-diamminedichloroplatinum (II) and have identified two complexes which bind with increased affinity to cis-diamminedichloroplatinum (II)-damaged DNA. Using monoclonal antibodies we have shown that one complex, B1, contains human single-stranded DNA binding protein, a protein known to be involved in the in vitro repair synthesis assay of mammalian excision repair.

Antibodies, Monoclonal↗
PubMed1992

Nursing theory as a base for a computerized nursing information system.

This article illustrates how nursing theory can be used in a computerized nursing information system (CNIS). Before development of such a system can begin, data relationships must be specified so that: (a) the relationships are specific enough to support a computerized relational base and (b) the resultant information can support nursing science. Both goals were achieved through three interrelated processes: (a) validation of a practice model based on Orem's self-care deficit nursing theory, (b) classification of clinical data into theory-related categories, and (c) establishment of data relationships to yield meaningful information.

Databases, Factual↗
PubMed1992

Blood pressure lowering and cerebral blood flow: a comparison of the effects of carvedilol and propranolol on the cerebral circulation in hypertensive patients.

The first part of this article concerns the general relation between blood pressure lowering and cerebral blood flow. Factors known to affect cerebral blood flow are reviewed, and recent advances in the field of innervation of cerebral blood vessels are outlined. Special emphasis is placed on the importance of the phenomenon of autoregulation and how this is disturbed in patients with hypertension. Not all antihypertensive drugs exert the same action on the cerebral circulation to produce the same blood pressure-lowering effect. In addition, the actions exerted by common antihypertensive drugs on the cerebral circulation are described. The second part of the article provides a comparison between the effect of carvedilol and that of propranolol on blood pressure reduction and cerebral blood flow. In a double-blind, crossover study involving 14 patients with mild-to-moderate hypertension, carvedilol was shown to have no effect on cerebral blood flow, whereas there was a slight tendency for lower flows to occur with the use of propranolol. Because of the small sample size, statistical significance was not reached. These results are consistent with other recently published findings.

Adolescent↗
PubMed1991

Single step selection of cis-diamminedichloroplatinum(II) resistant mutants from a human ovarian carcinoma cell line.

We have shown that cis diamminedichloroplatinum-(II) (DDP) resistant mutants can be isolated from the human ovarian carcinoma cell line A2780 using a single-step selection protocol with DDP. DDP resistant colonies were calculated to be present at a frequency of 1.7 x 10(-6)/viable cell using a fluctuation analysis. The mutational origin of these surviving colonies is inferred by the fact that their frequency is increased by treatment of the A2780 cells with the chemical mutagen ethyl methane-sulfonate, with a maximum frequency observed after a 3-day expression time. Independently isolated clones maintain, in the absence of selection, a DDP resistant phenotype up to 7-fold more resistant than the parental A2780 cells. The resistance modifiers aphidicolin and buthionine sulfoximine have no effect on the frequency of DDP resistant mutants. Therefore neither of these drugs appears to have an effect on increasing the sensitivity of DDP resistant mutants existing in a cell population prior to DDP exposure.

Aphidicolin↗
PubMed1991

Orem's general theory of nursing and community nursing.

The purpose of this article is to examine the way in which theoretical concepts of community articulate with Orem's theory. Philosophical and theoretical perspectives of community are presented as the basis for developing a model for community nursing. The development of nursing theory and science related to the concept of community proceeds from an understanding of community and its articulations with nursing. Three basic models of community are identified and described: (a) atomistic/contractarian, (b) organic/functional, and (c) mutual/personal. Orem's theory can be legitimately viewed as having meaning for nursing when the community is viewed from any of the three models. It is not limited to the use of "aggregate" models. The distinction comes in the view of community consistent with the underlying philosophical view of the nature of person expressed or inherent in the nursing theory. A general model for the community as a unit of service, congruent with Orem's theory, is presented.

Community Health Nursing↗
PubMed1990

Determination of selenium in blood plasma and serum by flow injection hydride generation atomic absorption spectrometry.

A flow injection hydride generation atomic absorption spectrometric (AAS) method has been used to determine the selenium concentrations of human serum and plasma samples following digestion with nitric, sulphuric and perchloric acids. In the hydride generation process, reduction was carried out by sodium tetrahydroborate to produce a hydride that was atomized in a flame-heated atomisation cell. The method had a detection limit of 1.2 ng ml-1 and a sensitivity of 2.1 ng ml-1. Within-run precisions of 5.8% at 20 ng ml-1 and 4.5% at 80 ng ml-1, and between-run precisions of 4.8% at 69 ng ml-1 and 3.4% at 80 ng ml-1 were obtained. An inter-laboratory comparison study with a graphite furnace AAS method was carried out and the results showed excellent agreement. The flow injection method of sample introduction allowed the use of a sample volume of 330 microliters with an injection rate of 90 injections per hour.

Borohydrides↗
PubMed1990

Validating nursing theory for use within a computerized nursing information system.

Computerized nursing information systems (CNISs) exemplify the application of computer science to nursing knowledge. For nursing knowledge to be a basis for CNIS development, variable relationships must be clearly defined, thus allowing transformation of data into knowledge. Nursing theories define variable relationships; these definitions, however, often are not specific enough on which to base data-based nursing information systems. This article describes how a nursing process model was derived from Self-Care Deficit Nursing Theory, the process model validated, and data relationships established within the model prior to its use as a structure for a CNIS.

Computer Simulation↗
PubMed1987

Allergic interstitial nephritis due to diazepam.

A 56-year-old man developed allergic interstitial nephritis and deterioration of preexisting chronic renal failure after receiving diazepam. On discontinuation of diazepam, kidney function returned to the baseline level and itching, eosinophilia, and eosinophiluria subsided. A causative correlation between allergic interstitial nephritis and diazepam is suggested.

Diazepam↗
PubMed1987

Vascular damage and factor-VIII-related antigen in the rheumatic diseases.

Factor-VIII-Related antigen (VIII R:Ag) is known to be produced by the blood vessel wall. Noxious stimuli increase endothelial release of VIII R:Ag. It might be expected that the development of vasculitis would be associated with increased levels of VIII R:Ag. To investigate this, eight different groups of subjects were studied: 25 patients with systemic sclerosis, 19 with systemic lupus erythematosus, 15 with rheumatoid arthritis (RA) plus vasculitis, 19 with systemic vasculitis and 14 with atherosclerosis. These groups were compared to 29 patients with primary Raynaud's disease, 15 with RA without vasculitis and 50 controls. Results showed that where there was evidence of vascular disease, then VIII R:Ag was elevated. VIII R:Ag appeared to be a more specific marker for vascular damage than erythrocyte sedimentation rate or C-reactive protein. Longitudinal studies in 11 patients showed good correlation between progression of vascular disease and VIII R:Ag.

Adult↗
PubMed1987

Platelet changes after a saturated fat meal and their prevention by Dazmegrel, a thromboxane synthetase inhibitor.

A saturated fat meal was given to 10 normal males both before and after pretreatment with UK38,485, a thromboxane synthetase inhibitor (Dazmegrel, Pfizer Central Research, Sandwich, Kent, United Kingdom). Following the fat meal at 2 and 4 hr there was laboratory evidence of platelet activation. Dazmegrel lowered baseline platelet activity and lessened platelet activation following the fat meal. This drug should be investigated further as a potential antithrombotic agent.

Adult↗
PubMed1987

Fibrinolysis in systemic lupus erythematosus: effect of desamino D-arginine vasopressin infusion.

In systemic lupus erythematosus (SLE) the lupus anticoagulant is known to be associated with thrombosis. However, this anticoagulant only occurs in a small percentage of patients. Histopathological studies suggest a more generalized thrombotic tendency with platelets and fibrin within the microvasculature. Fibrinogen is elevated in SLE and this may lead to the fibrin deposition described. We wondered if decreased fibrinolysis contributed to this and we infused desamino D-arginine vasopressin (DDAVP) into ten patients with SLE and eight controls. DDAVP stimulates endothelial production of plasminogen activator (PA) and factor VIII. Baseline results showed a significant decrease in PA activity with a concomitant increase in fibrinogen in SLE. The t-PA and inhibitor levels were normal but factor VIII was increased. After infusion of DDAVP, results indicated that, despite baseline results, SLE patients were able to respond to stimulation and the increase in PA activity produced a decrease in plasma fibrinogen levels. These findings may have therapeutic implications.

Adult↗