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Biomedical subjects

John Wilson

Publications and source records attributed to John Wilson.

At least 19 recordsLinked to original sources
PubMed2007

Estimation of oxygen uptake during fast running using accelerometry and heart rate.

UNLABELLED: Previous investigations have reported that accelerometer counts plateau during running at increasingly faster speeds. PURPOSE: To assess whether biomechanical and/or device limitations cause this phenomenon and the feasibility of generating oxygen uptake (.VO2) prediction equations from the combined use of accelerometry and heart rate during walking and running. METHODS: : Sixteen endurance-trained subjects completed two exercise tests on a treadmill. The first was a continuous incremental test to volitional exhaustion to determine ventilatory threshold and peak .VO2. The second was a discontinuous incremental exercise test while walking (3, 5, and 7 km.h(-1)) and running (8, 10, 12, 14, 16, 18, and 20 km.h(-1), or until volitional exhaustion). Subjects completed 3 min of exercise at each speed, followed by 3-5 min of recovery. Activity counts from uni- and triaxial accelerometers, heart rate, and gas exchange were measured throughout exercise. RESULTS: All accelerometer outputs rose linearly with speed during walking. During running, uniaxial accelerometer outputs plateaued, whereas triaxial output rose linearly with speed up to and including 20 km.h(-1). Prediction of .VO2 during walking and running using heart rate (R2 = 0.42 and 0.59, respectively), accelerometer counts (R2 = 0.48-0.83 and 0.76, respectively), the combined methodologies (R2 = 0.54-0.85 and 0.80, respectively), and the combined methodologies calibrated with individual data (R2 = 0.99-1.00 and 0.99, respectively) was completed by linear regression. CONCLUSIONS: Uni- and triaxial accelerometer outputs have a linear relationship with speed during walking. During running, uniaxial accelerometer outputs plateau because of the biomechanics of running, whereas triaxial accelerometer output has a linear relationship. The combined methodologies predict .VO2 better than either predictor alone; a subject's individually calibrated data further improves .VO2 estimation.

Acceleration↗
PubMed2006

Results of the 2004 Association of Residents in Radiation Oncology (ARRO) survey.

PURPOSE: The aim of this study was to document adequacy of training, career plans after residency, use of the in-service examination, and motivation for choice of radiation oncology as a specialty. METHODS AND MATERIALS: In 2004, the Association of Residents in Radiation Oncology (ARRO) conducted a nationwide survey of all radiation oncology residents in the United States. RESULTS: The survey was returned by 297 residents (response rate, 54%). Of the respondents, 29% were female and 71% male. The most popular career choice was joining an established private practice (38%), followed by a permanent academic career (29%). Residents for whom a permanent academic career was not their first choice were asked whether improvements in certain areas would have led them to be more likely to pursue an academic career. The most commonly chosen factors that would have had a strong or moderate influence included higher salary (81%), choice of geographic location (76%), faculty encouragement (68%), and less time commitment (68%). Of respondents in the first 3 years of training, 78% believed that they had received adequate training to proceed to the next level of training. Of those in their fourth year of training, 75% believed that they had received adequate training to enter practice. CONCLUSIONS: Multiple factors affect the educational environment of physicians in training. Data describing concerns unique to resident physicians in radiation oncology are limited. The current survey was designed to explore a variety of issues confronting radiation oncology residents. Training programs and the Residency Review Committee should consider these results when developing new policies to improve the educational experiences of residents in radiation oncology.

Attitude of Health Personnel↗
PubMed2006

Synthesis, structural characterization, experimental, and computational spectrophotometric studies of 8-quinolinyloxymethyphosphonate compounds.

The synthesis of diethyl-8-quinolinyloxymethylphosphonate 1 and 8-quinolinyloxymethylphosphonic acid hemihydroiodide 2 is reported along with their spectroscopic and analytical characteristics (NMR, infrared, mass spectra, and elemental analysis). The single-crystal X-ray structure of 2 is described. Solutions of the disodium phosphonate 3, from 2 and sodium hydroxide, were prepared and used in situ. The coordination complex between 1 and zinc chloride 4 is described according to its single-crystal X-ray structure. The spectrophotometric features (absorption and emission) of 1, 2, 3, and 4 are reported along with the fluorescence response and affinity of 3 to some metal cations. The origin of the fluorescence from compounds 1 and 4 is investigated using density functional theory and the oscillator strength for each transition is computed. Two deactivation pathways, one of which is only weakly emissive, are identified in 4. In contrast to 4, which is only moderately more emissive than 1 a strong zinc-activated fluorescence response is observed from aqueous solutions of 3.

Hydrogen Bonding↗
PubMed2006

Neuroimmunology of dancing eye syndrome in children.

Clinical, histopathological, and laboratory evidence suggest that dancing eye syndrome/opsoclonus-mycoclonus syndrome is an immune-mediated and probably autoimmune disorder. There is a clear, but not invariable, association with neuroblastoma or ganglioneuroma in children, and with a miscellany of neoplasms in adults. Direct support, i.e. the identification of antibodies against cell-surface antigens in neurons, is lacking but the nature of other evidence is such that the case for use of immunomodulatory therapeutic strategies is compelling. Because at least 85% of children affected by the condition are left with permanent cognitive deficits, notwithstanding a favourable initial neurological response to, say, steroid or adrenocorticotrophic hormone, therapeutic stakes are high. There is an urgent need for controlled therapeutic trials which, because of the comparative rarity of the condition in children, will require international collaboration to expedite studies.

Brain Diseases↗
PubMed2006

A multi-institutional analysis of the socioeconomic determinants of breast reconstruction: a study of the National Comprehensive Cancer Network.

OBJECTIVE: To determine the rate of postmastectomy reconstruction and investigate the impact of socioeconomic status on the receipt of reconstruction. SUMMARY BACKGROUND DATA: The National Comprehensive Cancer Network (NCCN) Outcomes Project is a prospective, multi-institutional database that contains data on all newly diagnosed breast cancer patients treated at one of the participating comprehensive cancer centers. METHODS: The study cohort consisted of 2174 patients with DCIS and stage I, II, and III invasive breast cancer who underwent mastectomy at one of 8 NCCN centers. Rates of reconstruction were determined. Logistic regression analyses were used to evaluate whether socioeconomic characteristics are associated with breast reconstruction. RESULTS: Overall, 42% of patients had breast reconstruction following mastectomy. Patients with Medicaid and Medicare were less likely to undergo reconstruction than those with managed care insurance; however, there was no difference for indemnity versus managed care insurance. Homemakers and retired patients had fewer reconstructions than those employed outside the home. Patients with a high school education or less were less likely to have reconstruction than those with more education. Race and ethnicity were not significant predictors of reconstruction. CONCLUSIONS: The reconstruction rate in this study (42%) is markedly higher than those previously reported. The type of insurance, education level, and employment status of a patient, but not her race or ethnicity, appear to influence the use of breast reconstruction. Because all patients were treated at an NCCN institution, these socioeconomic differences cannot be explained by access to care.

Adult↗
PubMed2006

Oxygen uptake and muscle desaturation kinetics during intermittent cycling.

PURPOSE: To investigate the kinetics of O2 uptake (VO2) and m. vastus lateralis [deoxyhemoglobin] ([Hb]) (near-infrared spectroscopy) for supramaximal intermittent cycling. METHODS: Six males performed a ramp test for determination of VO2peak and lactate threshold. On different days, they completed four intermittent "work:recovery" tests (10 s:20 s, 30 s:60 s, 60 s:120 s, 90 s:180 s) for 30 min or to the tolerable limit; "work" = 120% peak work rate (WRpeak) attained on the ramp, "recovery" = 20 W. RESULTS: Arterialized capillary [lactate] ([L]c) profiles were dependent on duty-cycle length and resembled those for constant-load exercise classically used to assign exercise intensity: 10 s:20 s-no increase (i.e., "moderate", with first-order VO2 kinetics); 30 s:60 s-increased but stable (i.e., "heavy," with first-order VO2 kinetics supplemented by a slow component (VO2 sc) that stabilizes); 60s:120s-progressive increase that was more marked for 90 s:180 s (i.e., "very heavy" or "severe," with first-order VO2 kinetics supplemented by a VO2 sc projecting to VO2peak). VO2 and Delta[Hb] oscillated with WR, the ensemble-averaged single-cycle oscillation amplitudes (peak-to-nadir) for each individual subject increasing with WR duty-cycle duration. In the 30-s:60-s test, with [L]c being elevated, there was also a tendency towards a modest VO2 sc, with an increase in individual VO2 peak values early in the test and VO2 not fully recovering back to baseline in recovery. This was more marked for the 60-s:120-s duty cycle: VO2 failed to recover completely back to baseline, and the peaks of the VO2 oscillations increased significantly with time (F = 30.7, P < 0.001); in some cases, VO2peak was attained and exhaustion rapidly ensued. CONCLUSION: VO2 kinetics in intermittent exercise over a range of duty-cycle durations tended to associate with blood [lactate] profiles, similarly to previous demonstrations for sustained constant-load exercise.

Adult↗
PubMed2005

Phagocytosis stimulates mobilization and shedding of intracellular CD16A in human monocytes and macrophages: inhibition by HIV-1 infection.

Surface and intracellular staining coupled with flow cytometric analysis was used to show for the first time that human macrophages and a minor subset of peripheral blood monocytes have an internal pool of CD16A, which is mobilized and shed during Fc receptor for immunoglobulin G-mediated phagocytosis. Human immunodeficiency virus type 1 (HIV-1) infection of monocyte-derived macrophages in vitro led to a reduction in the phagocytosis-induced up-regulation in CD16A shedding. These results suggest that monocytes and macrophages may be a source of soluble CD16A, which is elevated in the serum of patients in a variety of disease states and that the mobilization and shedding of CD16A in response to phagocytosis are disrupted by HIV-1 infection.

Cells, Cultured↗
PubMed2005

Body composition assessment in adults with cystic fibrosis: comparison of dual-energy X-ray absorptiometry with skinfolds and bioelectrical impedance analysis.

OBJECTIVE: We compared body composition measurement in adults with cystic fibrosis (CF) by using non-invasive methods (skinfold thicknesses and bioelectrical impedance analysis [BIA]) with dual-energy X-ray absorptiometry (DXA). METHODS: Seventy-six adults with CF (mean age 29.9 +/- 7.9 y, mean body mass index 21.5 +/- 2.5 kg/m(2)) were studied. Body composition was measured to calculate fat-free mass (FFM) using DXA, the sum of four skinfold thicknesses, and BIA (predictive equations of Lukaski and of Segal). RESULTS: Mean FFM values +/- standard deviation measured using DXA were 54.8 +/- 7.3 kg in men and 41.2 +/- 3.9 kg in women. Mean FFM values measured using BIA/Lukaski were 51.5 +/- 7.8 kg in men and 40.4 +/- 4.9 kg in women (P < 0.0005 for men, not significant for women for comparison with DXA). Mean FFM values measured using BIA/Segal were 54.2 +/- 7.5 kg for men and 44.1 +/- 5.9 kg for women (not significant for men, P < 0.0005 for women for comparison with DXA). Mean FFM values measured using skinfolds were significantly higher than those for FFM with DXA (57.2 +/- 7.2 kg in men, 43.3 +/- 4.3 kg in women, P < 0.0005 for comparison with DXA). The 95% limits of agreement with FFM using DXA were, for men and women, respectively, -8.3 to 1.7 kg and -6.4 to 4.8 kg for BIA/Lukaski, -4.8 to 3.6 kg and -3.1 to 8.9 kg for BIA/Segal, and -2.8 to 7.3 kg and -1.5 to 5.7 kg for skinfolds. CONCLUSION: This study suggests that skinfold thickness measurements and BIA will incorrectly estimate FFM in many adults with CF compared with DXA measurements of FFM. These methods have limited application in the assessment of body composition in individual adult patients with CF.

Absorptiometry, Photon↗
PubMed2005

Endothelial activation and increased heparan sulfate expression in cystic fibrosis.

RATIONALE: Pulmonary disease in cystic fibrosis (CF) is characterized by an exaggerated interleukin (IL)-8-driven, neutrophilic, inflammatory response to infection. Binding of IL-8 to heparan sulfate (HS)-containing proteoglycans (HSPG) facilitates binding of the chemokine to its specific receptor, stabilizes and prolongs IL-8 activity, and protects it from proteolysis. We hypothesized that increased expression of HSPG contributes to the sustained inflammatory response in CF bronchial tissue. OBJECTIVES: Our objectives were to analyze the distribution and abundance of IL-8 and HS, in intact and cleaved forms, in bronchial tissue from adult patients with CF or chronic obstructive pulmonary disease (COPD) and a control group without inflammatory airway disease. METHODS: Immunostaining and quantitative image analysis were applied to ethanol-fixed and paraffin-embedded tissue obtained at transplant in patients with CF or COPD, or postmortem in the control group. MEASUREMENTS AND MAIN RESULTS: Quantitative immunohistochemical analysis demonstrated significant disease-related differences. Intact HS was significantly more abundant in epithelial and endothelial basement membranes in CF than in COPD or the control group. Conversely, cleaved HS was significantly more abundant in COPD than the other groups. More IL-8-positive blood vessels were observed in CF and COPD compared with the control group, whereas more extensive IL-8 expression in the epithelium was observed in CF compared with COPD. CONCLUSIONS: Sustained neutrophil recruitment in the CF airway may therefore be related not only to increased IL-8 expression but also to the increased stability and prolonged activity and retention of IL-8 when it is bound to HSPG in bronchial tissue.

Adult↗
PubMed2005

Practice parameter: utility of electrodiagnostic techniques in evaluating patients with suspected peroneal neuropathy: an evidence-based review.

An evidence-based review of electrodiagnostic (EDX) techniques in the evaluation of peroneal neuropathy was conducted to determine whether these techniques are useful for diagnosis and prognostication in this disorder. A Medline search and a review of relevant sources were performed in 1999 and updated through July 2003 to identify articles describing the use of EDX in patients suspected to have peroneal neuropathy. From the 499 articles identified, 112 articles describing motor and sensory nerve conduction studies and needle electromyography in peroneal neuropathy were reviewed in detail; 11 articles met the predetermined literature inclusion criteria for the adequacy of EDX techniques employed. Six articles provided Class III evidence in support of a role for nerve conduction studies in making the diagnosis of peroneal neuropathy; five articles provided Class IV evidence. Implicit in making the diagnosis were normal EDX findings outside the distribution of the peroneal nerve. The current literature supports the use of EDX in patients with suspected peroneal neuropathy (Level C recommendation).

Electrodiagnosis↗
PubMed2005

The potential importance of nut removal by rodents from Australian macadamia orchards.

Extensive crop damage due to rodents, predominantly the black rat (Rattus rattus) is a major concern to both the Hawaiian and Australian macadamia industries. Within Australian systems, indicated the importance of adjacent non-crop habitats in the damage process with damage being directly related to the size and temporal stability of these habitats. It was also suggested that the current estimates of crop loss might be underestimates as R. rattus may remove nuts into adjacent non-crop habitats, however, the economic significance of nut removal was not investigated. This study has determined that the crop loss due to nut removal is equivalent to the crop loss due to in-crop feeding within the first row of the orchard, with nuts being removed and consumed under the cover provided by weedy adjacent habitats. Previous studies (White et al.,1997; Horskins et al.,1998; White et al.,1998) investigating the impact of rodents on crop damage have ignored the nut removal component of the damage process and hence rodents have a far greater impact on the Australian macadamia industry than previously suggested. This study also indicates that the cost-benefit of habitat manipulation as a rodent management strategy is much greater than that suggested by . Habitat manipulation is not only a cost-effective means of damage control but is also sustainable, having none of the potentially adverse public health and environmental effects of continual rodenticide use.

Agriculture↗
PubMed2004

Contralateral breast cancer and thromboembolic events in African American women treated with tamoxifen.

BACKGROUND: Information about breast cancer treatment and prevention in African American women is scant, and recommendations for therapy from clinical trials for breast cancer are based primarily on data obtained from white women. METHODS: We compared the effects of tamoxifen on risk of contralateral breast cancer and thromboembolic events in African American women and white women with a history of primary breast cancer. Data from 13 National Surgical Adjuvant Breast and Bowel Project clinical trials were pooled for analyses of time to contralateral breast cancer as a first event (eight trials and 10,619 patients) and of time to any thromboembolic phenomenon as a first event (all 13 trials and 20,878 patients). Risk factors for contralateral breast cancer and thromboembolic events among all women were determined using univariate proportional hazards models. (For each racial group, the rate of events associated with tamoxifen use was calculated as the ratio of the incidence rate with tamoxifen to that without tamoxifen.) Proportional hazards regression models were used to calculate 95% confidence intervals (CIs) and risk ratios. All statistical tests were two-sided. RESULTS: Risk factors for contralateral breast cancer were body mass index (BMI) and lymph node positivity; those for thromboembolic events were BMI and age. In women of both ethnicities with estrogen receptor-positive breast cancer, those who took tamoxifen experienced a similar reduction in contralateral breast cancer (risk ratio for African American women = 0.74, 95% CI = 0.46 to 1.17, n = 690; risk ratio for white women = 0.76, 95% CI = 0.59 to 0.98, n = 9929; P = .92). Tamoxifen was also associated with an increase in thromboembolic events. The relative risk for thromboembolic events was higher in both African American and white women treated with tamoxifen and chemotherapy than in those who were treated with tamoxifen alone (risk ratio for African American women = 10.70, 95% CI = 5.94 to 19.28 versus 2.16, 95% CI = 1.26 to 3.71; n = 1842; risk ratio for white women = 15.49, 95% CI = 9.53 to 25.17 versus 3.13, 95% CI = 2.04 to 4.79, n = 19,036), and this effect was similar between the races (P = .10). CONCLUSIONS: African American and white women appear to have the same risks of contralateral breast cancer and thromboembolic events in response to tamoxifen treatment.

Adult↗
PubMed2004

A new method for defining and managing process alarms and for correcting process operation when an alarm occurs.

A new mathematical treatment of alarms that considers them as multi-variable interactions between process variables has provided the first-ever method to calculate values for alarm limits. This has resulted in substantial reductions in false alarms and hence in alarm annunciation rates in field trials. It has also unified alarm management, process control and product quality control into a single mathematical framework so that operations improvement and hence economic benefits are obtained at the same time as increased process safety. Additionally, an algorithm has been developed that advises what changes should be made to Manipulable process variables to clear an alarm. The multi-variable Best Operating Zone at the heart of the method is derived from existing historical data using equation-free methods. It does not require a first-principles process model or an expensive series of process identification experiments. Integral with the method is a new format Process Operator Display that uses only existing variables to fully describe the multi-variable operating space. This combination of features makes it an affordable and maintainable solution for small plants and single items of equipment as well as for the largest plants. In many cases, it also provides the justification for the investments about to be made or already made in process historian systems. Field Trials have been and are being conducted at IneosChlor and Mallinckrodt Chemicals, both in the UK, of the new geometric process control (GPC) method for improving the quality of both process operations and product by providing Process Alarms and Alerts of much high quality than ever before. The paper describes the methods used, including a simple visual method for Alarm Rationalisation that quickly delivers large sets of Consistent Alarm Limits, and the extension to full Alert Management with highlights from the Field Trials to indicate the overall effectiveness of the method in practice.

Algorithms↗
PubMed2004

Immunisation against Helicobacter felis infection protects against the development of gastric MALT Lymphoma.

UNLABELLED: The formation of mucosa-associated lymphoid tissue (MALT) in response to Helicobacter pylori infection is closely associated with the development of primary gastric MALT lymphoma. AIM: To examine whether immunisation against Helicobacter felis can protect against development of MALT lymphoma. RESULTS: The majority of control infected mice demonstrated MALT formation (13/15) and five developed lymphoma. Fifteen immunised mice were protected against bacterial challenge, of which only five had evidence of MALT formation and none developed lymphoma. Interestingly, of the four mice in which immunisation failed, all developed MALT and two of these had lymphoma. CONCLUSION: Effective immunisation against Helicobacter infection can protect against gastric MALT lymphoma. To our knowledge this is the first demonstration of vaccination protecting against a bacteria-induced malignancy.

Animals↗
PubMed2004

Molecular mechanism for distinct neurological phenotypes conveyed by allelic truncating mutations.

The molecular mechanisms by which different mutations in the same gene can result in distinct disease phenotypes remain largely unknown. Truncating mutations of SOX10 cause either a complex neurocristopathy designated PCWH or a more restricted phenotype known as Waardenburg-Shah syndrome (WS4; OMIM 277580). Here we report that although all nonsense and frameshift mutations that cause premature termination of translation generate truncated SOX10 proteins with potent dominant-negative activity, the more severe disease phenotype, PCWH, is realized only when the mutant mRNAs escape the nonsense-mediated decay (NMD) pathway. We observe similar results for truncating mutations of MPZ that convey distinct myelinopathies. Our experiments show that triggering NMD and escaping NMD may cause distinct neurological phenotypes.

Alleles↗
PubMed2004

Cyclin F disruption compromises placental development and affects normal cell cycle execution.

Human cyclin F was originally isolated as a cDNA capable of suppressing the temperature sensitivity of a Saccharomyces cerevisiae cdc4-1 mutant. Its tightly regulated expression and high conservation in the evolutionary progression from amphibians to mammals suggest that it coordinates the timing of a critical cell cycle event. The fact that it contains an F box and can form an SCF (Skp1-Cul1/Cdc53-F-box) complex in vivo further suggests that it may also function in proteolysis. To investigate the role of cyclin F in vivo, we generated mice deficient for cyclin F and conditionally deficient mice as well as mouse embryonic fibroblasts (MEFs) conditionally deficient for cyclin F. Heterozygous animals are normal and fertile, but CycF(-/-) animals, with a myriad of developmental anomalies due in large part to failures in yolk sac and chorioallantoic placentation, die around embryonic day 10.5. Tissue-specific deletion of cyclin F revealed that it was not required for the development and function of a number of different embryonic and adult tissues. In contrast, MEFs lacking cyclin F, while viable, do exhibit cell cycle defects, including reduced population-doubling time and a delay in cell cycle reentry from quiescence, indicating that cyclin F plays a role in cell cycle regulation.

Animals↗
PubMed2004

Craniopagus: second Brisbane case. Case report.

Craniopagus is a rare and intriguing condition with an incidence of one in 2.5 million births. The chance of a neurosurgeon seeing a case in a working lifetime is unlikely. The chances of two cases from the same community within 12 months are remote in the extreme. The authors present a second case of craniopagus born and separated in Brisbane, Australia, in 2001 and discuss the intricacies of surgical separation and the lessons learned.

Australia↗