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Biomedical subjects

A Wells

Publications and source records attributed to A Wells.

At least 181 records · Page 10Linked to original sources
PubMed1981

Epstein-Barr virus receptor expression is correlated to cell cycle phase.

Epstein-Barr virus (EBV) receptor positive cells absorbed FITC-conjugated virions and were subsequently stained for DNA content with propidium iodide. These cells were analyzed by flow cytometry to determine the relationship between cell cycle and EBV receptor (EBVR) expression on single cells. EBVR was present throughout the entire cell cycle. The level of expression, however, varied; increasing in G1 and G2/M while remaining approximately constant in S phase. Analysis of receptor density in terms of cell size demonstrated that smaller cells, in early G1, have a greater density of receptors per unit membrane than larger G2/M and S phase cells.

Animals↗
PubMed1980

Effects of sighs and different tidal volumes on compliance, functional residual capacity and arterial oxygen tension in normal and hypoxemic dogs.

In order to assess the usefulness of sighs in preventing deterioration of arterial PO2 (PaO2), functional residual capacity (FRC), and compliance in hypoxemic patients, the authors studied 20 anesthetized and paralyzed dogs. The dogs were ventilated with either normal (11.5 ml/kg) or large (23 ml/kg) tidal volumes and their lungs were either normal or made edematous with oleic acid injection. Sighs (46 ml/kg) were administered periodically and PaO2, FRC, and compliance were measured at intervals between sighs. In dogs with normal lungs, regardless of tidal volume, sighs produced a transient increase in compliance and FRC but PaO2 was not significantly affected. In dogs with pulmonary edema, sighs produced inconsistent effects on FRC and compliance and, interestingly, PaO2 decreased after the sighs may be unnecessary in patients with pulmonary edema, especially when they are already receiving large tidal volumes.

Animals↗
PubMedDate not supplied

Modelling cognition in emotional disorder: the S-REF model.

Cognitive therapy techniques are applied to an ever-increasing range of psychological disorders. However, both basic methods and general theory of therapy have evolved more slowly. Although cognitive therapy is based on experimentally testable concepts derived from cognitive psychology, an integration of these areas capable of explaining cognitive-attentional phenomena and offering treatment Implications remains to be achieved. In this paper, we outline the Self-Regulatory Executive Function (S-REF) model of emotional disorder, which integrates information processing research with Beck's schema theory. The model advances understanding of the roles of stimulus-driven and voluntary control of cognition, procedural knowledge (beliefs), and of the interactions between different levels of information-processing. It also accounts for cognitive bias effects demonstrated in the experimental psychopathology literature. The model presents implications concerning not only what should be done in cognitive therapy, but how cognitive change may be most effectively accomplished.

Affective Symptoms↗
PubMedDate not supplied

Beliefs about worry and intrusions: the Meta-Cognitions Questionnaire and its correlates.

This report describes the development of the Meta-Cognitions Questionnaire to measure beliefs about worry and intrusive thoughts. Factor analyses of the scale demonstrated five empirically distinct and relatively stable dimensions of meta-cognition. Four of the factors representing beliefs were: Positive Beliefs About Worry: Negative Beliefs About the Controllability of Thoughts and Corresponding Danger; Cognitive Confidence; and Negative Beliefs about Thoughts in General, including Themes of Superstition, Punishment and Responsibility. The fifth factor represented Meta-Cognitive processes-Cognitive Self-Consciousness-a tendency to be aware of and monitor thinking. The measure showed good psychometric properties on a range of indices of reliability and validity. Scores on the questionnaire subscales predicted measures of worry proneness, proneness to obsessional symptoms, and anxiety. Regression analyses showed that the independent predictors of worry were: Positive Beliefs about Worry; Negative Beliefs About the Controllability of Thoughts and Corresponding Danger: and Cognitive Confidence. Significant differences in particular MCQ subscales were demonstrated between patients with intrusive thoughts, clinical controls and normals. The implications of these findings for models of worry and intrusive thoughts are discussed.

Adolescent↗
PubMedDate not supplied

Proliferative response of fibroblasts expressing internalization-deficient epidermal growth factor (EGF) receptors is altered via differential EGF depletion effect.

We describe experiments comparing the proliferation responses to epidermal growth factor (EGF) by NR6 fibroblasts expressing genetically engineered epidermal growth factor receptors (EGFRs). These cells present either wild-type (WT) EGFR or a cytoplasmic domain-truncated (c'973) EGFR that exhibits a decreased ligand-induced internalization rate constant. In two distinct in vitro proliferation assays, with or without medium replenishment, we measured the specific cell proliferation rate constants and EGF depletion kinetics for both WT and c'973 cells. When EGF depletion is minimized by replenishment, the EGF concentration dependencies of the two cell types are similar, whereas when EGF depletion is not prevented, maximal proliferation of WT cells requires an initial EGF concentration that is approximately 10x that required by c'973 cells. However, when EGF depletion is accounted for, the dependencies of growth rate for the two cell types on the current EGF concentration in both assays are essentially identical. Our results demonstrate that diminished depletion of EGF from the extracellular medium is a major reason for increased mitogenic sensitivity to EGF by cells possessing internalization-deficient receptors.

3T3 Cells↗
PubMedDate not supplied

Youth homicide.

Explore the source record for details and available documents.

Adolescent↗
PubMedDate not supplied

Differential in vitro effects of chemotherapeutic agents on primary cultures of human ovarian carcinoma.

The treatment of ovarian cancer principally relies on the use of platinum and taxane chemotherapeutic agents. Short-term clinical results have been encouraging, but long-term responses remain limited. In this report, an in vitro assay system that utilizes cells grown from human tumor explants has been used to quantitatively evaluate responses to relevant concentrations of alternative chemotherapeutic agents. The results suggest that there are significant differences in the responses of explant-derived cultured cells to the different agents tested. In an evaluation of 276 primary ovarian cancer specimens, five nonstandard drugs were tested in 51 cases. Of these 51 cases, cyclophosphamide had the highest rate of response at 67%, followed by doxorubicin at 61%, gemcitabine at 49%, etoposide at 48%, and topotecan at 14%. Venn diagrams, representing the in vitro responses to the platins and taxanes, as well as the responses to the nonstandard drugs, illustrate that there clearly are distinct differences among patients in a given population. These data underscore the potential importance of evaluating each patient's response to a number of different drugs to optimize the therapeutic decision-making process.

Antineoplastic Agents↗
PubMedDate not supplied

Progression-free interval in ovarian cancer and predictive value of an ex vivo chemoresponse assay.

The study objective was to determine the effectiveness of a phenotypic chemoresponse assay in predicting response to chemotherapy measured by progression-free interval (PFI) in a retrospective series of ovarian cancer patients whose tumor specimens had been tested with the ChemoFx assay. A statistically significant correlation between assay prediction of response and PFI was observed in 256 cases with an exact or partial match between drug(s) assayed and received. In 135 cases with an exact match, the hazard ratio for progression of the resistant group was 2.9 (confidence interval [CI]: 1.4-6.3; P < 0.01) compared to the sensitive group and 1.7 (CI: 1.2-2.5) for the intermediate compared to the sensitive group. The median PFI for patients treated with drugs assayed as resistant was 9 months, 14 months for those with drugs assayed as intermediately sensitive, and PFI had not been achieved for those with drugs assayed as sensitive. These data indicate that the ChemoFx assay is predictive of PFI in ovarian cancer. As the majority of ovarian cancers display different degrees of response to different chemotherapy agents ex vivo, the incorporation of assay information into treatment selection has the potential to improve clinical outcomes in ovarian cancer patients.

Adult↗