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Biomedical subjects

J Doyle

Publications and source records attributed to J Doyle.

At least 55 records · Page 3Linked to original sources
PubMed1999

Effect of pulsed dexamethasone therapy on tolerance of intravenously administered lipids in extremely low birth weight infants.

We investigated the effect of dexamethasone on parenteral lipid tolerance in 7-day-old extremely low birth weight infants (n = 28) in a randomized, double-blind trial. Serum triglycerides were measured before and after 3 days of dexamethasone or placebo treatment. Infants treated with dexamethasone responded with higher triglyceride concentrations and greater sensitivity to incremental increases in the intravenous lipid dose.

Dexamethasone↗
PubMed1999

The effect of induced mood states on performance profile areas of perceived need.

The performance profile technique is now widely used by a range of sports scientists, usually as the first step in implementing a training programme. The aim of this study was to examine the effect of altered mood states on areas of perceived need for an individual identified by the performance profile. Sixty-seven university sports science students (30 females, 37 males) participated in the study. They completed their performance profile and a shortened version of the Bi-polar Profile of Mood States before and after four separate mood manipulation treatments (happy, sad, neutral, control). The participants were allocated at random to one of four groups and completed the treatments in a counterbalanced order. Mood manipulation checks identified that both the happy and sad manipulations were successful. Profile areas of perceived need, identified through discrepancies in an individual's perceptions of ideal and current state, were not affected by the sad and neutral manipulations or by the control condition. However, areas of perceived need were significantly lower after the happy mood manipulation than before the treatment. Our results show that asking individuals to complete their profiles when in a happy mood state is likely to affect judgements and result in an underestimation of perceived need for improvement.

Adult↗
PubMed1999

Highly optimized tolerance: a mechanism for power laws in designed systems.

We introduce a mechanism for generating power law distributions, referred to as highly optimized tolerance (HOT), which is motivated by biological organisms and advanced engineering technologies. Our focus is on systems which are optimized, either through natural selection or engineering design, to provide robust performance despite uncertain environments. We suggest that power laws in these systems are due to tradeoffs between yield, cost of resources, and tolerance to risks. These tradeoffs lead to highly optimized designs that allow for occasional large events. We investigate the mechanism in the context of percolation and sand pile models in order to emphasize the sharp contrasts between HOT and self-organized criticality (SOC), which has been widely suggested as the origin for power laws in complex systems. Like SOC, HOT produces power laws. However, compared to SOC, HOT states exist for densities which are higher than the critical density, and the power laws are not restricted to special values of the density. The characteristic features of HOT systems include: (1) high efficiency, performance, and robustness to designed-for uncertainties; (2) hypersensitivity to design flaws and unanticipated perturbations; (3) nongeneric, specialized, structured configurations; and (4) power laws. The first three of these are in contrast to the traditional hallmarks of criticality, and are obtained by simply adding the element of design to percolation and sand pile models, which completely changes their characteristics.

Journal Article↗
PubMed1999

The influence of training on tinnitus perception: an evaluation 12 months after tinnitus management training.

Sixty-five subjects were reviewed 12 months after tinnitus management training, which had been comprised variously of information, relaxation training and a therapeutic noise strategy. Seventy-four per cent of subjects reported increased habituation to tinnitus (n = 48), 65% reported reduced tinnitus annoyance (n = 42), and 52% reported an increased ability to cope with tinnitus (n = 34). Twenty-five per cent of subjects reported deterioration in coping ability (n = 16), 23% reported reduced habituation to tinnitus (n = 15) and 8% reported increased tinnitus-related annoyance (n = 5). None of the management strategies were found to be significantly more effective than others in facilitating improved coping or habituation to tinnitus. Subjects who reported reduced coping and habituation to tinnitus experienced greater levels of general life stress than subjects who reported increased habituation and coping ability. The use of relaxation therapies as applied in this study did not appear to influence the level of tinnitus distress or the level of life stress. Thirty-seven per cent of subjects given long-term low-level white noise (LTWN) stimulation reported benefit. However, LTWN stimulation did not significantly alter tinnitus awareness or the minimum masking level (MML) of tinnitus. Long-term low-level white noise stimulation appeared to influence cognitive reaction to tinnitus rather than its physical perception. Subjects who initially had low ability to cope with tinnitus and preferred a more active coping style reported significantly greater benefit from LTWN stimulation than subjects whose primary approach to coping was to regulate the emotional impact of tinnitus.

Adaptation, Psychological↗
PubMed1999

Transient myeloproliferative disorder (transient leukemia) and hematologic manifestations of Down syndrome.

Transient Myeloproliferative Disorder (Transient Leukemia) is found in approximately 10% of newborn infants with Down Syndrome. It is characterized by the large numbers of megakaryoblasts in the peripheral blood, variable thrombocytopenia and, in a minority of cases, by a lethal course with hydrops fetalis or progressive hepatic fibrosis. Evidence is presented that this disease is truly leukemia, which, in most cases, recovers spontaneously. There is evidence that hematopoiesis is abnormal in Down Syndrome children who do not have leukemia. These abnormalities of red cells, platelets, and granulocytes are reviewed.

Child, Preschool↗
PubMed1998

A high-throughput, microtiter plate assay for paralytic shellfish poisons using the saxitoxin-specific receptor, saxiphilin.

An isoform of the paralytic shellfish poison (PSP)-specific receptor saxiphilin, from the tropical centipede Ethmostigmus rubripes, was used as the basis for a radiometric, high-throughput, microtiter plate assay for this group of toxins. Characterization of the assay revealed that it was able to detect several representatives from the various structural PSP subgroups and yet was insensitive toward tetrodotoxin. To test the utility of the assay as a seafood toxin-monitoring tool, the assay was subjected to a variety of marine organism extracts, some of which were known to contain PSPs, and whole extract toxicity expressed as STX equivalents (STXeq) was measured by two methods: First, by comparison of values from a screening assay with a standard STX inhibition curve and, second, for highly active extracts, by calculation using the IC50 from a full inhibition curve of the extract. For extracts which could be quantified by both methods, there was almost 100% correlation between the derived values. STXeq derived by both methods from the bioassay highly correlated with absolute toxin quantities from HPLC analysis.

Amphibian Proteins↗
PubMed1998

The effect of ongoing litigation on outcome scores following open reduction and internal fixation of the calcaneum.

All sixteen patients who had undergone open reduction and internal fixation (ORIF) of the calcaneum by the senior author between April 1993 and August 1996 were included in the study. Two had died from unrelated illnesses and one had failed to attend any follow-up following discharge. The remaining 13 were reviewed by the main author. As part of a complete clinical, radiological and functional assessment, Buckley and Meek (B&M) and Kerr and Atkins (K&A) outcome scores were calculated as well as a satisfaction score obtained by a visual analogue scale (VAS). Statistical analysis of the results using Wilcoxen's paired and unpaired ranking scores showed that the initial grade of the fracture, degree of operative reduction, correction of width of the heel and post-operative ranges of motion had no significant correlation to either B&M or K&A outcome scores or to the VAS score. However, the presence of ongoing litigation was significantly correlated to the scores (VAS < 0.01, B&M < 0.05, K&A < 0.05). These findings cast doubt on the validity of post operative scoring for fracture of the calcaneum in the presence of ongoing litigation.

Calcaneus↗
PubMed1998

Pre-operative planning in orthopaedics: a study of surgeons' opinions.

Pre-operative planning is important in orthopaedic surgery in both trauma and elective orthopaedic surgery. We know of no study into surgeons attitudes to pre-operative planning. A postal questionnaire was used to ascertain attitudes to planning. 94% of consultants and 100% of trainees felt that planning was important but half, respectively, routinely planned fracture treatment. Only 24% of trainees and 44% consultants traced fracture configurations from radiographs. 88% of trainees and 91% of consultants felt that planning should be undertaken more often with 94% of consultants expressing a view that trainees should do more planning. Pre-operative planning is good practice and from our study we have shown both trainees and consultants feel it should be undertaken more often.

Attitude of Health Personnel↗
PubMed1998

New indications for radical prostatectomy.

PURPOSE: Radical prostatectomy is considered the gold standard for treatment of localized prostate cancer, either as primary or salvage therapy. Recently with the advent of increased organ transplantation, use of prostatic specific antigen for cancer detection and cryoablation as an alternative treatment, more men with prostate cancer can be considered for radical surgery. We review these new indications. MATERIALS AND METHODS: Clinically localized untreated prostate cancers were identified in 3 men being considered for cardiac or lung transplantation (group 1), and 4 men originally treated with transperineal cryoablation had local relapse (group 2). All 7 men underwent radical prostatectomy. RESULTS: Organ confined cancer (pT2C) was found in all 3 patients in group 1. All 3 men underwent successful cardiac or lung transplantation 1 to 12 months after radical prostatectomy, and they are disease-free at short-term followup. Of the group 2 patients 2 had organ confined disease (pT2b and c) and 2 had extensive extraprostatic disease (pT3cN1 and pT3cN0). Only 2 patients remain disease-free and do not require adjuvant endocrine therapy. Major perioperative complications of rectotomy and total incontinence occurred only in group 2 patients. CONCLUSIONS: Patients being considered for heart and lung transplantation need to be free of concurrent malignancy because of immunosuppressive therapy. Radical prostatectomy can achieve this goal in select patients. Cases of failed cryoablation can be salvaged with radical prostatectomy but with less chance of success and with greater risk of complications.

Aged↗
PubMed1998

Psychobiology and the athlete with anterior cruciate ligament (ACL) injury.

Over the past decade, research has increasingly highlighted the need for psychological aspects associated with sporting injury to be considered in treatment programmes. However, contemporary practice continues to focus on the treatment of the physical injury. The purpose of this article is to summarise research and contemporary thoughts on the psychological aspects associated with sporting injury. The potential for incorporating both physical and psychological aspects into the treatment of injury is discussed with special reference to the anterior cruciate ligament (ACL) injury. Specifically, the potential importance of athlete involvement throughout the treatment programme is discussed. Additionally, the physical and psychological measures that are available to the sports medicine team to measure rehabilitation outcome are critically evaluated. The limitations of psychological measures of the athlete's perception of outcome are outlined. Evidence for the utility of the performance profile technique is critically evaluated. The technique provides valid and reliable measures of the idiosyncratic responses of athletes to injury to provide a framework for effective treatment for optimised outcome.

Anterior Cruciate Ligament Injuries↗
PubMed1998

Prisoners as patients. The experience of delivering mental health nursing care in an Australian prison.

Correctional or prison mental health nursing is a highly specialized area of practice that has undergone substantive role development in recent years. However, little research has explored aspects of prison-based nursing practice or practice arrangements. The experience of delivering mental health nursing care in prison can be disempowering, resulting in feelings of frustration, isolation, and stigma. In developed nations, prison mental health nurses face the rewarding challenge of gaining greater recognition for the specialized nature of their practice and their key role in the correctional and criminal justice continuum.

Female↗
PubMed1997

Mutations in the Cacnl1a4 calcium channel gene are associated with seizures, cerebellar degeneration, and ataxia in tottering and leaner mutant mice.

Tottering and leaner, two mutations of the mouse tottering locus, have been studied extensively as models for human epilepsy. Here we describe the isolation, mapping, and expression analysis of Cacnl1a4, a gene encoding the alpha subunit of a proposed P-type calcium channel, and also report the physical mapping and expression patterns of the orthologous human gene. DNA sequencing and gene expression data demonstrate that Cacnl1a4 mutations are the primary cause of seizures and ataxia in tottering and leaner mutant mice, and suggest that tottering locus mutations and human diseases, episodic ataxia 2 and familial hemiplegic migraine, represent mutations in mouse and human versions of the same channel-encoding gene.

Amino Acid Sequence↗
PubMed1997

Platelet and immune responses to oral cyclic dexamethasone therapy in childhood chronic immune thrombocytopenic purpura.

OBJECTIVE: To examine the effectiveness of cyclic oral high-dose (HD) dexamethasone therapy in pediatric patients with chronic immune thrombocytopenic purpura (ITP), which has been reported to cause complete remission in adults with chronic ITP. STUDY DESIGN: Eleven children with primary chronic ITP, with a median disease duration of 28 months (range, 6 to 120 months), were treated with cycles of HD dexamethasone therapy. RESULTS: Excellent short-term responses (initial platelet counts < or = 50 x 10(9)/L, increasing to > 100 x 10(9)/L within 72 hours of completion of an HD dexamethasone cycle) were observed in 78% of 41 cycles. Long-term effects include one complete response (platelet count > or = 150 x 10(9)/L) and three partial responses (platelet count > or = 50 and < 150 x 10(9)/L) in 11 children followed for 6 or more months after completing cyclic HD dexamethasone therapy. Because side effects were substantial, three children did not complete their sixth treatment cycle. At day 6 of treatment, B lymphocytes were significantly increased (p = 0.005). CONCLUSIONS: Dexamethasone, given orally in high doses, is an effective drug in achieving short-term platelet responses, but it induced long-term remissions in fewer than half of the children with well-established chronic ITP. Its effect on B lymphocytes requires further elucidation. A prospective, controlled study will be needed to establish whether cyclic HD dexamethasone therapy can alter the natural history of children with early chronic ITP and thus avoid splenectomy.

Administration, Oral↗
PubMed1997

Does vitamin C cause hemolysis in premature newborn infants? Results of a multicenter double-blind, randomized, controlled trial.

OBJECTIVE: We tested the hypothesis that vitamin C supplementation of premature neonates is associated with hemolysis. STUDY DESIGN: A double-blind, randomized, controlled trial of vitamin C supplementation (50 mg/day) was undertaken in premature neonates (birth weight, 1000 to 1500 gm). Infants were randomly assigned to receive vitamin C (Ce-Vi-Sol) (n = 32) or placebo (n = 24) for 14 days. Twenty-three subjects per group were required to detect a difference of 1 SD in corrected carboxyhemoglobin values (alpha = 0.05, beta = 0.10). RESULTS: Day 14 vitamin C levels were lower in control subjects than in supplemented neonates (62 +/- 24 vs 125 +/- 62 micromol/L, p = 0.005). There was no difference in corrected blood carboxyhemoglogin concentrations (0.72 +/- 0.44 vs 0.72 +/- 0.23%; p = 0.95), other parameters of hemolysis, weight gain, blood sampled, presumed septic episodes, necrotizing enterocolitis, feeding intolerance, or transfusion. On day 14, bilirubin values were higher in control subjects than in the supplemented group (77 +/- 37 vs 55 +/- 33 micromol/L; p = 0.04). When a distant outlier in the nonsupplemented group was excluded (163 micromol/L), statistical significance was lost (73 +/- 32 vs 55 +/- 33 micromol/L; p = 0.09). CONCLUSION: Oral supplementation of premature infants with vitamin C is not associated with evidence of increased erythrocyte destruction, hyperbilirubinemia, or other morbidity.

Anemia, Hemolytic↗
PubMed1997

Leukemia and/or myeloproliferative syndrome in neonates with Down syndrome.

Approximately 10% of newborn infants with Down Syndrome develop a form of megakaryoblastic leukemia which usually disappears spontaneously during the first months of life. The evidence that this "Transient Leukemia" is truly leukemia includes the following: it is clonal proliferation, it can be fatal and tissue infiltration of leukemic cells occurs. Also in approximately 25% of cases that recover, Acute Megakaryoblastic Leukemia will develop in the first four years of life, which, if not treated, is fatal. Evidence regarding the megakaryoblastic nature of the leukemic cells is presented as well as a description of the lethal forms of the disease. The study of Transient Leukemia is of considerable importance because it can provide insight into both the nature of leukemia and its relation to trisomy 21.

Biopsy↗