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Biomedical subjects

A E Williams

Publications and source records attributed to A E Williams.

At least 19 recordsLinked to original sources
PubMed2005

Enhanced immunopathology induced by very virulent infectious bursal disease virus.

Immunohistochemical and flow cytometric analyses of the bursa, spleen and thymus following infection with the very virulent infectious bursal disease virus (vvIBDV) strain UK661 revealed discrete differences from classical virulent infectious bursal disease virus strains. Bu-1+, immunoglobulin (Ig)M+ and IgG+ cells were all depleted from the bursa, spleen and thymus, suggesting loss of both immature and mature B lymphocytes. Small numbers of Bu-1+ cells repopulated the bursa 14 days post-infection but few of these expressed IgM or IgG. A transient increase in macrophages at 3 to 5 days post-infection was followed by a later influx of CD4+ and CD8+ T cells into the bursa. Loss of cortical thymocytes during the acute phase of infection suggested disruption of the T-cell system. The results showed that vvIBDV strain UK661 caused earlier and more severe pathology than classical virulent strains of infectious bursal disease virus. The marked influx of T cells into the infected bursa indicates that cell-mediated immunity is likely to be important in the clearance of vvIBDV.

Animals↗
PubMed2005

Are outcomes the same with all dry powder inhalers?

Most clinicians and patients would intuitively say that the inhaler device used influences the outcome achieved in asthma. However, it is important to have objective evidence to support or refute this view. Systematic reviews have suggested that there is no difference in clinical effectiveness between dry powder inhalers and metered-dose inhalers. However, the studies included in the review were randomised clinical trials and not studies based on real-life clinical practice. In the real world, the efficacy of products as determined in a specified and well-monitored population is only one aspect of product performance--patient characteristics and behaviour are critical. Observational studies in real-world primary care settings suggest that the choice of inhaler device has an important impact on asthma outcomes. The IMS Mediplus database has now been used to compare outcomes among patients receiving initial maintenance therapy with beclometasone dipropionate administered via different dry powder inhalers. Patients using the DISKHALER dry powder inhaler used significantly less short-acting beta(2)-agonist than those using the ROTAHALER dry powder inhaler. This suggests a difference in the level of asthma control with the different devices, even when the same chemical entity is delivered. Real-world studies suggest, therefore, that outcomes are not always the same with all dry powder inhalers. This indicates the need for further studies to investigate the impact of inhaler device choice and the impact of switching between devices.

Administration, Inhalation↗
PubMed2005

Unscheduled healthcare resource use among asthma patients receiving low-dose inhaled corticosteroids maintenance treatment.

This survey describes asthma control and unscheduled healthcare resource use (HCRU) among patients receiving low-dose inhaled corticosteroids (ICS) alone in five European countries and the USA. Physicians and patients completed forms collecting data on asthma symptoms, sudden increase in chest/respiratory symptoms, asthma-related HCRU, quality of life (QoL) and drug therapy. Fifty-seven per cent of patients on low-dose ICS alone had physician-rated moderate or severe asthma. Only 13% of patients receiving low-dose ICS alone achieved asthma control; 36% reported nocturnal wakening and 22% reported unscheduled healthcare services in the past year. Gender, symptom frequency, episodes of sudden increase in chest/respiratory symptoms and impaired QoL were all related to unscheduled healthcare resource utilisation. Many patients receiving low-dose ICS alone do not have adequate asthma control. Some patient characteristics were found to be significantly different, but not exclusive, between unscheduled healthcare resource users and non-users.

Adolescent↗
PubMed2004

Nutritional changes among premenopausal women undertaking a soya based dietary intervention study in Hawaii.

BACKGROUND: We conducted a 2-year nutritional intervention among premenopausal women. The goal was to incorporate two daily servings of soya into the regular diet. This report describes the dietary modifications and assesses their nutritional adequacy with regard to major nutrients. METHODS: In this analysis of 100 intervention and 106 control subjects, women completed a validated food-frequency questionnaire at baseline; throughout the study, they participated in at least three unannounced 24-h recalls. RESULTS: At randomization, both groups were similar in age and body weight, reported low soya intake, and did not differ by intake of major nutrients and foods. According to the 24-h recalls, women in the intervention group consumed nearly two servings of soya per day, while the control women remained at 0.2 servings. In comparison with the control group, the intervention group consumed fewer dairy products, primarily milk, but also less meat, nuts and seeds. As a result of the dietary modification, the intervention women consumed less-saturated fat and cholesterol and more protein, dietary fibre, calcium and vitamins than the control group. CONCLUSION: These results suggest that women in the intervention group improved the overall quality of their diet by adding two servings of soya per day.

Adult↗
PubMed2003

Mammographic densities in a one-year isoflavone intervention.

The estrogenic and antiestrogenic effects of isoflavones, phytoestrogens contained in soy foods, have been proposed as mechanisms for the possible involvement of soy products in the development of breast cancer. We investigated the hypothesis that isoflavones reduce mammographic density, a predictor of breast cancer risk. We conducted a double-blind randomized trial in premenopausal women who received a daily 100 mg isoflavone supplement or a placebo over 12 months. Compliance with the study regimen was confirmed by urinary isoflavones and tablet counts. We used a computer-assisted method to measure mammographic density and paired t-tests to assess changes in mammographic characteristics from baseline to follow-up mammogram. Complete sets of mammograms were available for 30 women. The two groups differed by age and mammographic density at baseline, but were similar in body weight and nutritional intakes. We detected no significant changes either in the size of the dense areas or in the per cent densities. A non-significant decrease in breast area among intervention group subjects was probably the result of methodological issues in comparing mammograms taken under different conditions. In conclusion, our findings do not support the hypothesis that isoflavones decrease mammographic density during a one-year intervention. Although this exploratory study had limited power, it appears that isoflavones do not exert an estrogenic effect similar to hormone replacement therapy on mammographic density.

Adult↗
PubMed2001

Prevalence, donation practices, and risk assessment of blood donors with hemochromatosis.

CONTEXT: Despite changes in eligibility policies, practical barriers limit blood donations from individuals with hemochromatosis. Increased knowledge of hemochromatosis donor characteristics may help foster further changes that will promote more donations. OBJECTIVES: To estimate the prevalence of donors diagnosed as having hemochromatosis and to compare rates of unreported deferrable risks for transfusion-transmissible viral infections (TTVIs), positive screening test results for TTVIs, and donation patterns between hemochromatosis patient donors and donors reporting no medical conditions necessitating phlebotomy (non-health-related donors). DESIGN: An anonymous mail survey conducted in 1998 as part of the ongoing Retrovirus Epidemiology Donor Study. SETTING AND PARTICIPANTS: Among a stratified probability sample of 92 581 blood donors from 8 geographically diverse US blood centers, 52 650 (57%) responded. MAIN OUTCOME MEASURES: Prevalence of hemochromatosis among blood donors; prevalence of unreported deferrable risks and positive screening test results for TTVIs among hemochromatosis patient donors vs non-health-related donors. RESULTS: One hundred ninety-seven respondents (0.4%) identified themselves as hemochromatosis patients and 50 079 (95.1%) as non-health-related donors. An estimated 0.8% of all donations were from hemochromatosis patients, 45.8% of whom reported that they had donated blood to treat their illness. The proportion of repeat donors was higher in hemochromatosis patients than in non-health-related donors (83.5% vs 76.5%; P =.03). Among repeat donors, 68.7% of hemochromatosis patients reported donating at least 3 times in the past year compared with 49.1% of non-health-related donors (P<.001). The prevalence of unreported deferrable risks for TTVIs was similar in hemochromatosis patients (2.0%) and non-health-related donors(3.1%) as was the overall prevalence of positive screening test results (1.3% of hemochromatosis patients vs 1.6% of non-health-related donors). CONCLUSIONS: Although significant numbers of hemochromatosis patients reported donating blood for therapeutic reasons, our findings suggest that this population does not present a greater risk to blood safety than other donors.

Adult↗
PubMed2001

The potential impact of incentives on future blood donation behavior.

BACKGROUND: It is important to assess the potential efficacy and safety of offering donation incentives as part of recruitment and retention programs. STUDY DESIGN AND METHODS: In 1995, 7489 allogeneic donors responded to an anonymous mail survey that inquired about demographics, donation history, infectious disease risks, and the potential appeal of incentives. RESULTS: The projected net effect of offering blood credits and medical testing would be to motivate, respectively, 58 percent and 46 percent of donors to return, whereas offering an item of limited value would motivate 20 percent to do so. First-time and younger donors reported more frequently than repeat or older donors that incentives would appeal to them. Donors attracted by cash were 60 percent more likely to have a risk for transfusion-transmissible infections (p = 0.03). Although not statistically significant, the odds of being an at-risk donor were higher among individuals attracted by tickets to events (OR 1.5) and extra time off work (OR 1.2). CONCLUSION: These findings suggest that offering blood credits and (though to a lesser extent) items of limited value could be safe and effective strategies for retaining donors. Although medical tests were found to have broad appeal, studies are needed to identify tests in which donors would be most interested.

Behavior↗
PubMed2001

Repeat whole-blood and plateletpheresis donors:unreported deferrable risks, reactive screening tests, andresponse to incentive programs.

BACKGROUND: Evaluating plateletpheresis (PPH) and repeat community whole-blood (RWB) donors' responses to donation incentive programs is essential for developing effective donor retention programs. STUDY DESIGN AND METHODS: Using data from a 1998 anonymous questionnaire sent to 92,581 US blood donors, the prevalence of unreported deferrable risks, screening test reactivity, and response to incentives were compared in RWB and PPH donors by the use of weighted chi-square tests and logistic regression analyses. RESULTS: From 52,650 respondents, 38,884 RWB and 2,028 PPH donors were identified. Levels of screening test reactivity (1%) and unreported deferrable risks (UDRs, 2-3%) were similar in RWB and PPH donors. RWB and PPH donors were strongly encouraged or discouraged by similar incentives. Of the incentives that would encourage a higher proportion of UDR-free RWB donors to return, cholesterol screening and earning a blood credit appealed to >50 percent. Similar results were obtained for cholesterol screening in PPH donors. Community service or education credits, premarital screening, and cash had limited appeal for PPH and RWB donors, respectively, and would be more likely to differentially encourage donors with a UDR to return. CONCLUSION: Incentives that were associated with the greatest donor appeal and that minimized the potential recruitment of more risky donors were identified.

Adult↗
PubMed2001

Absence of risk factors for false-positive test results in blood donors with a reactive test result in an automated treponemal test (PK-TP) for syphilis.

BACKGROUND: Screening and confirmatory serologic tests for syphilis are known to generate false-positive results in low-risk populations, which include blood donors. This study assessed whether conditions previously reported to cause biological false-positive (BFP) test results for syphilis are relevant to contemporary syphilis testing of blood donors and the extent to which seropositive donors report a history of syphilis. STUDY DESIGN AND METHODS: A history of conditions reported to be associated with BFP syphilis tests or a history of syphilis infection was assessed by a case-control study of donors with reactive and nonreactive automated treponemal test results, using an anonymous mail survey. Analysis of cases was stratified by fluorescent treponemal antibody absorption (FTA-ABS) result. RESULTS: Adjusted ORs (95% CIs) for reported BFP-associated conditions were 1.3 (0.8-2.1) for FTA-ABS-positive cases and 0.8 (0.3-1.9) for FTA-ABS-negative cases. Among responding blood donors, syphilis history was reported in 78 (51%) of 153 FTA-ABS-positive cases, 0 of 142 FTA-ABS-negative cases, and 3 (0.4%) of 716 automated treponemal test (PK-TP)-negative controls. CONCLUSION: Approximately half of donors with FTA-ABS-positive test results reported a syphilis history. There was no difference between reported BFP conditions for FTA-ABS-positive or FTA-ABS-negative cases and controls. This information may be useful when providing donors with better predonation or post-test counseling information about syphilis testing.

Adolescent↗
PubMed2001

Seroprevalence of known and putative hepatitis markers in United States blood donors with ALT levels at least 120 IU per L.

BACKGROUND: ALT testing of blood donors was initiated as a surrogate marker for non-A, non-B hepatitis. Increased sensitivity of subsequent HBV and HCV tests used for standard donor screening make any residual value of ALT testing questionable. STUDY DESIGN AND METHODS: A prospective study was conducted in 166 of 645 eligible blood donors from three American Red Cross regions whose ALT was > or =120 IU per L and whose standard donor screening tests were negative. Of these enrolled donors, 124 (75%) completed follow-up. Samples obtained from the index donation, at enrollment (1 month), and at follow-up (6 months) underwent the standard donor screening tests, as well as those for HCV RNA and HGV RNA (RT-PCR), antibodies to the virus envelope E2 protein of GB virus type C (GBV-C E2 antibody), and IgM antibody for CMV, parvovirus B19, EBV VCA, and HAV. Participants completed a brief demographic and exposure history questionnaire at follow-up. RESULTS: All study samples were negative in standard donor-screening tests. ALT levels were variable at return visits, with 80 to 86 percent <120 IU per L. No participants were positive for HCV RNA; 4 percent were positive for HGV RNA, and 10 percent were positive for GBV-C E2 antibody. Results of CMV, parvovirus B19, EBV VCA, and HAV testing were similar to published background rates. No demographic or exposure history variables had significant correlation with ALT or other testing results. CONCLUSION: These data suggest that an ALT > or =120 IU per L in blood donors with negative standard screening tests has questionable value as a surrogate marker for seronegative HBV or HCV infection. Continued ALT testing may contribute little, if anything, to the safety of blood components or plasma for further manufacture.

Adolescent↗
PubMed2001

Knowledge of HIV/AIDS transmission and screening in United States blood donors.

BACKGROUND: Increased knowledge of HIV transmission and behavioral and test screening may encourage high-risk blood donors to self-defer. STUDY DESIGN AND METHODS: Knowledge of HIV transmission and screening and the association with demographics, screening test reactivity, and unreported deferrable risks (UDRs) was assessed by a 1998 anonymous mail survey sent to 92,581 blood donors, of whom 57 percent responded. Groups were compared by using weighted chi-square tests and logistic regression analysis. RESULTS: Four percent of the donors thought that it was very likely or somewhat likely for a person to contract HIV from donating blood, and 20 percent perceived a similar risk from blood transfusion. Only 60 percent of the donors knew that the available screening tests may not detect a recent infection. Thirty-seven percent either did not know or felt it was acceptable to donate blood to obtain HIV testing. Those most likely to answer knowledge questions incorrectly were more likely to have a higher prevalence of test reactivity or UDRs and to be <or=25 years old, members of a minority, less educated, non-US-born, or first-time donors. CONCLUSION: Innovative ways to increase donor understanding of the implications of risk behaviors and the limitations of current screening procedures should be developed. They might prevent high-risk individuals from donating blood.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Aortic body chemodectoma causing pulmonary oedema in a cat.

A seven-year-old male domestic shorthaired cat was presented with persistent dyspnoea. Thoracic radiography and echocardiography revealed pulmonary oedema and a mass at the base of the heart. At necropsy the mass was found to be an aortic body chemodectoma that had metastasised to the sternal lymph node. This is a rare tumour in the cat, the third reported case where there was evidence of metastasis, and only the second reported case where there was evidence of lymphocytic infiltration of the primary tumour. Pulmonary oedema is an unusual presentation of this tumour in the cat.

Animals↗