Search PubMed⌕ Search

Biomedical subjects

A Doyle

Publications and source records attributed to A Doyle.

At least 19 recordsLinked to original sources
PubMed1999

Progressive maturation resistance to microcystin-LR cytotoxicity in two different hepatospheroidal models.

To develop three-dimensional (3D) cytotoxicity models further, microcystin-induced cytoskeletal disruption was tested in two different models of multicellular hepatocyte aggregate formation (hepatospheroids). Rat hepatocyte suspensions were seeded either onto poly(2-hydroxyethylmethacrylate)-treated culture wells (poly-HEMA) or in a rotating wall vessel (RWV) device which provides minimal shear forces and enhances differentiated 3D growth. Ninety percent of spheroids forming on poly-HEMA tended to fuse and form nonhomogeneous multilobular structures by day 4 of incubation. In contrast, spheroids cultured in the low-shear environment formed homogeneous aggregates that averaged 126 + 10 microm diameter in size at day 7. Microcystin-LR (10(-6) mol/L) was put into contact (90 min in serum-free medium) with hepatocyte suspensions and spheroids formed in both systems for 1, 4 or 7 days. As already described, microcystin-LR (after 90 min), induced cytoskeletal disruptions (blebs) in 98% of the isolated primary hepatocytes maintained in suspension. In 3D cultures, blebs were detected only on poly-HEMA nonhomogeneous early prespheroids. All other mature spheroids (poly-HEMA or RWV) exposed to the toxin did not exhibit obvious morphological signs of toxicity. Moreover, microcystin-LR pre-incubation with hepatocyte suspension prevented the formation of conventional spheroids. In conclusion, the low-shear, simulated-microgravity environment generated high yields of regularly engineered spheroids. In both models, progressive resistance of mature spheroids to microcystin-LR-induced cell deformation developed with time in culture. Microcystin-LR inhibition of the formation of rat hepatospheroids in isolated hepatocyte suspension could be used as a complementary biological assay for detection of the presence of biologically active microcystin-LR in water samples.

Animals↗
PubMed1999

Folic acid knowledge and use among expectant mothers in 1997: a comparison with 1996.

This study examined changes in folic acid knowledge and use among antenatal women in Dublin maternity hospitals between 1996 and 1997, following a campaign to improve the very low uptake of peri-conceptional folic acid. The results showed significant improvements between the two years. Almost 76% of respondents had heard of folic acid in 1997 compared with 54% in 1996 (p < 0.01), with a shift in the proportion of people hearing of folic acid from hospital doctors to general practitioners (GP). Almost 43% of respondents in 1997 knew that folic acid can prevent spina bifida compared with 21% in 1996 (p < 0.01). A higher proportion was taking folic acid prior to conception in 1997 (16% vs 6%, p < 0.01). We conclude that the improvements may have been in part due to the promotional campaign among health professionals, women's groups and the media. However, less than a fifth of women were taking folic acid peri-conceptionally in 1997 and there is still scope for much improvement.

Adult↗
PubMed1998

Regional and molecular separation of the four bioactivities of 'tribulin'.

The endocoid tribulin has four known bioactivities: monoamine oxidase A and B inhibitory activities (MAO-AI and MAO-BI) and peripheral and central benzodiazepine receptor binding inhibitory activities (PBR-I and CBR-I). Analysis of the four bioactivities in rat tissue reveals regional dissociation. Most notably liver was particularly rich in PBR-I yet contained no detectable MAO-AI. In addition we have succeeded in separating the four activities from human urine. MAO-AI and MAO-BI have greater retention on charcoal than PBR-I and CBR-I when eluted step-wise with aqueous methanol. MAO-AI can be separated from MAO-BI and in addition PBR-I can be separated from CBR-I by step aqueous methanol elution from Amberlite XAD-4. Hence we present two lines of evidence that, contrary to the original view, tribulin is composed of a number of distinct molecular components.

Adrenal Glands↗
PubMed1998

Endogenous monoamine oxidase A inhibitory activity (tribulin), measured in saliva, is related to cardiovascular reactivity in normal individuals.

Salivary monoamine oxidase A inhibitory activity (MAO-AI), mean arterial blood pressure (MAP) and heart rate (HR) were determined simultaneously in healthy male students (n = 13) at rest, before a mild psychological stressor, twice during the task and 18 minutes after the end of the task. The sample as a whole showed significant differences in MAP and HR across occasions (respectively, p < 0.001 for both). Salivary MAO-AI could distinguish novice and experienced game players (p < 0.02) and was consistently positively correlated with MAP (r = 0.58, p < 0.05 on occasion 2). Pre-task measures of MAO-AI for an increased sample (n = 18) were associated with higher MAP (but not HR) throughout the experiment (p < 0.05). Those subject with falling MAO-AI profiles from task to recovery showed significantly greater simultaneous decline in HR than those with a rising MAO-AI profile (p < 0.05).

Adult↗
PubMed1997

Managed care for the elderly in the United States: outcomes to-date and potential for future growth.

With the growth in frail elderly populations, health providers and policymakers are exploring new models of caring for and financing the care of disabled elders. This paper reviews innovative care programs directed toward maintaining elders with dependency-producing physical and mental disabilities in home and community-based programs, and toward minimizing the use of acute and long-term institutional care. These programs represent improvements over the traditional fragmented care and financing mechanisms by integrating patient management responsibilities into one provider organization. Some programs integrate only primary and acute care, while others integrate only the continuum of long-term care services. A third set of programs, the key focus of this paper, integrate the full continuum of care from primary through acute and long-term care services. Coupled with service integration is financial consolidation, with control over all sources of funds transferred to the managing provider along with some level of financial risk. Outcomes in terms of lowered acute care utilization and successful site duplication are described, and future prospects for program adoption on a national scale are addressed.

Aged↗
PubMed1997

Social problem solving in hyperactive-aggressive children: how and what they think in conditions of automatic and controlled processing.

Examined how and what children think under conditions of automatic and controlled processing within the context of social problem solving. In a condition that elicited automatic processing, hyperactive-aggressive children did not differ in being able to identify the components of a problem or in the number of solutions generated to solve a problem, but were more aggressive in the types of solutions generated, as compared to nonhyperactive-nonaggressive children. Furthermore, in a condition eliciting controlled processing, hyperactive-aggressive children did not differ in identifying problem components, generating solutions, or in anticipating outcomes for solutions, but were less able to anticipate consequences, and were more aggressive in choosing a best solution to solve a problem, as compared to nonhyperactive-nonaggressive children. The study demonstrated a relation between problem-solving codes that discriminated between groups, and overall child adjustment. Implications for social problem-solving interventions are discussed.

Adult↗
PubMed1997

Convergent and criterion-related validity of the Behavior Assessment System for Children-Parent Rating Scale.

Examined aspects of the validity of the Behavior Assessment System for Children (BASC; Reynolds & Kamphaus, 1992) Parent Rating Scale (BASC-PRS) in 156 children with cross-setting disruptive behavior. The BASC-PRS is a recently published multidimensional measure composed of conceptually derived scales created for use in conjunction with psychiatric and educational classification systems. Convergent validity was assessed through correlations of BASC-PRS scale scores with scale scores on the Child Behavior Checklist/4-18 (CBCL/4-18; Achenbach, 1991b). Criterion-related validity was evaluated as the ability of BASC-PRS and CBCL/4-18 scales to predict membership in diagnostic groupings (no diagnosis, attention deficit hyperactivity disorder [ADHD] only, and ADHD with a comorbid externalizing disorder) derived via structured interviews based on the third, revised edition of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1987). Results showed the validity of the BASC-PRS to be comparable to that of the CBCL/4-18. Given its conceptually derived scales, the BASC-PRS may prove to be a useful-tool for assessing childhood disruptive behavior.

Attention Deficit Disorder with Hyperactivity↗
PubMed1996

Urinary output of endogenous monoamine oxidase inhibitory activity is related to everyday stress.

The MAO A and B inhibitory components of urinary tribulin were investigated in normal individuals (11 males and 24 females, mean age +/- SD; 27.1 +/- 4.5 years) in relation to everyday stress. Volunteers collected a urine sample at the same time (late evening) on five days over a single week. On each occasion subjects also completed a mood adjective checklist which measured perceived stress levels over the day in question. For each subject all daily measures were aggregated. Mean individual urinary MAO A and B inhibitory activity was found to be positively correlated with stress scores both before (r = 0.38, p < 0.05 and r = 0.37, p < 0.05 respectively, n = 35) and after (r = 0.35, p < 0.05 and r = 0.33, p < 0.05 respectively, n = 35) correction for the effects of urinary volume. These results suggest that in normal healthy individuals high endogenous MAO inhibitory activity in the urine is indicative of a relatively enduring state of everyday stress.

Adult↗
PubMed1996

Salivary monoamine oxidase A and B inhibitory activities correlate with stress.

MAO A and B inhibitory activities were determined, for the first time, in saliva samples. Saliva was collected on 4 occasions from 11 normal subjects (students) before and after delivering an important assessed oral presentation, a naturalistic stress inducing procedure. The first sample was collected 30 minutes before the presentation and 3 more within 40 minutes of finishing the presentation. At each collection a mood adjective checklist was completed. Mean MAO A inhibitory activity correlated with mean MAO B inhibitory activity (r = 0.872, p < 0.001, n = 11). Within subject analysis revealed a positive correlation between MAO A and B inhibitory activity and stress (r = 0.400, p < 0.01, n = 44 and r = 0.255, NS, n = 38 respectively). Mean MAO A and B inhibitory activity correlated with mean stress (r = 0.535, NS, n = 11 and r = 0.673, p < 0.05, n = 11 respectively). Peak MAO A and B inhibitory activities correlated with peak stress (r = 0.636, p < 0.05, n = 11 and r = 0.754, p < 0.01, n = 11, respectively). Salivary MAO A and B inhibitory activities were independent of salivary flow rate. We conclude that measurement of MAO A and B inhibitory activities in saliva is preferable to traditional urinary measures as sampling is less invasive and also supports a clear relationship to stress in normal individuals.

Female↗
PubMed1995

Molecular immunobiology of macrophages: recent progress.

Macrophage molecules involved in adhesion, signalling, secretion and interactions with pathogens and T-helper lymphocytes have been cloned and defined using monoclonal antibodies and genetic disruption. Studies of the regulation of macrophage differentiation and activation by cytokines have yielded insights into the heterogeneity of their functions in natural and acquired immunity, including immunity to infections by mycobacteria and HIV.

Animals↗
PubMed1995

Spinal anaesthesia for transurethral surgery: comparison of 2% lignocaine with hyperbaric 0.5% bupivacaine.

We have compared 2% lignocaine 3.5 ml with 0.5% hyperbaric bupivacaine 3 ml in a randomized, double-blind study in 30 patients undergoing subarachnoid anaesthesia for transurethral surgery. A sensory level of T10 was produced more quickly (P = 0.0001) and maximum height reached sooner (P = 0.0002) with lignocaine, although there was a greater reduction in systolic arterial pressure (P = 0.03) and a trend towards slower heart rates (P = 0.056). Return of full sensory and motor function occurred earlier with lignocaine (P = 0.00005 and P = 0.02).

Aged↗