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J Bryant

Publications and source records attributed to J Bryant.

At least 55 records · Page 3Linked to original sources
PubMed2000

Which pneumococcal serogroups cause the most invasive disease: implications for conjugate vaccine formulation and use, part I.

We analyzed >70 recent data sets to compare the serogroups causing invasive pneumococcal disease (IPD) with those represented in conjugate vaccine formulations. Five to 8 and 10-11 serogroups comprise at least 75% of pneumococcal isolates from young children and older children/adults, respectively, in each geographic region. Serogroups in the 7-valent formulation (4, 6, 9, 14, 18, 19, and 23) cause 70%-88% of IPD in young children in the United States and Canada, Oceania, Africa, and Europe, and <65% in Latin America and Asia. Serogroups in the 9-valent formulation (7-valent+1, 5) cause 80%-90% of IPD in each region except Asia (66%). Serogroup 1 accounts for >6% of IPD in each region, including Europe, except the United States and Canada and Oceania. In contrast, several serogroups not found in 7-, 9-, and 11-valent conjugate formulations are significant causes of disease in older children/adults. Nevertheless, each conjugate formulation could prevent a substantial IPD burden in each region and age group.

Adolescent↗
PubMed2000

The contribution of specific pneumococcal serogroups to different disease manifestations: implications for conjugate vaccine formulation and use, part II.

To assess whether certain serogroups of Streptococcus pneumoniae are preferentially associated with specific disease manifestations, we analyzed all recent pneumococcal disease studies and assessed the relative frequency of isolation of each serogroup by clinical site (as a proxy for different disease states). In all age groups, serogroups 1 and 14 were more often isolated from blood, and serogroups 6, 10, and 23 were more often isolated from cerebrospinal fluid (CSF); in young children, serogroups 3, 19, and 23 were more often isolated from middle ear fluid (MEF). Serogroups represented in conjugate vaccines were isolated slightly less frequently from CSF than from blood or MEF. Nonetheless, serogroups in the 9-valent conjugate vaccine formulation still comprised approximately 75% of pneumococcal isolates from the CSF of young children in Europe and in the United States and Canada. These analyses indicate that pneumococcal conjugate vaccines could potentially prevent a substantial proportion of episodes of bacteremic disease, pneumonia, meningitis, and otitis media, especially in young children.

Adolescent↗
PubMed2000

Efficacy of a new cream formulation of mupirocin: comparison with oral and topical agents in experimental skin infections.

A new cream formulation of mupirocin developed to improve patient compliance was compared with systemic and topical antibiotics commonly used to treat primary and secondary skin infections. A mouse surgical wound model infected with Staphylococcus aureus or Streptococcus pyogenes was used. Topical treatment was applied at 4 and 10 h postinfection or oral treatment at a clinically relevant dose was administered 4, 8, and 12 h postinfection; treatments were continued three times daily for a further 3 days. Mupirocin cream was significantly more effective than (P < 0.01; two of eight studies) or not significantly different from (six of eight studies) mupirocin ointment in reducing bacterial numbers. Mupirocin cream was similar in efficacy to oral flucloxacillin but significantly more effective (P < 0.001) than oral erythromycin. It was also similar in efficacy to cephalexin against S. pyogenes but superior against S. aureus (P < 0.01). Mupirocin cream had a similar efficacy to fusidic acid cream against S. aureus but was significantly superior against S. pyogenes (P < 0.01). A hamster impetigo model infected with S. aureus was also used. Topical or oral treatment was administered at 24 and 30 h postinfection (also 36 h postinfection for oral therapy) and then three times daily for a further 2 days. On day 5, mupirocin cream was significantly more effective than mupirocin ointment in one study (P < 0.01) and of similar efficacy in the other two studies. Mupirocin cream was not significantly different from fusidic acid cream or neomycin-bacitracin cream, but it was significantly superior (P < 0.01) to oral erythromycin and cephalexin. Mupirocin cream was as effective as, or superior to, oral and other topical agents commonly used for skin infections.

Administration, Oral↗
PubMed2000

Plant enzymes but not Agrobacterium VirD2 mediate T-DNA ligation in vitro.

Agrobacterium tumefaciens, a gram-negative soil bacterium, transfers DNA to many plant species. In the plant cell, the transferred DNA (T-DNA) is integrated into the genome. An in vitro ligation-integration assay has been designed to investigate the mechanism of T-DNA ligation and the factors involved in this process. The VirD2 protein, which is produced in Agrobacterium and is covalently attached to T-DNA, did not, under our assay conditions, ligate T-DNA to a model target sequence in vitro. We tested whether plant extracts could ligate T-DNA to target oligonucleotides in our test system. The in vitro ligation-integration reaction did indeed take place in the presence of plant extracts. This reaction was inhibited by dTTP, indicating involvement of a plant DNA ligase. We found that prokaryotic DNA ligases could substitute for plant extracts in this reaction. Ligation of the VirD2-bound oligonucleotide to the target sequence mediated by T4 DNA ligase was less efficient than ligation of a free oligonucleotide to the target. T-DNA ligation mediated by a plant enzyme(s) or T4 DNA ligase requires ATP.

Adenosine Triphosphate↗
PubMed2000

Microbiological conditions of sheep carcasses from conventional or inverted dressing processes.

At a small abattoir, 25 sheep carcasses were dressed conventionally, with the carcass suspended by the rear legs, and 25 carcasses were dressed while inverted, with the carcasses suspended by the forelegs. Two swab samples were obtained from randomly selected sites on each carcass, and total aerobic, coliform, and Escherichia coli counts were enumerated for each sample. Each type of count was arranged in two sets of 25 counts for each type of dressing process, and a log mean number and/or log total number recovered was calculated for each set of counts. The log mean number of total aerobic counts for one set of counts from carcasses dressed while inverted was less than the corresponding log mean numbers for both sets from the conventionally dressed carcasses and the other set from the carcasses dressed while inverted, and differed from them by about 0.7 log units. The coliforms recovered from carcasses were largely E. coli. The log total numbers of coliform or E. coli counts recovered from carcasses dressed while inverted were about 1.5 log units less than the corresponding log total numbers recovered from conventionally dressed carcasses. Those data indicate that the substitution of inverted for conventional dressing might serve to reduce the numbers of E. coli on sheep carcasses by reducing the microbiological contamination of the hindquarters but that the general microbiological condition of the carcasses would be little improved unless some means of preventing or removing contamination of the forequarters was also used.

Abattoirs↗
PubMed2000

Benchmarks of fairness for health care reform: a policy tool for developing countries.

Teams of collaborators from Colombia, Mexico, Pakistan, and Thailand have adapted a policy tool originally developed for evaluating health insurance reforms in the United States into "benchmarks of fairness" for assessing health system reform in developing countries. We describe briefly the history of the benchmark approach, the tool itself, and the uses to which it may be put. Fairness is a wide term that includes exposure to risk factors, access to all forms of care, and to financing. It also includes efficiency of management and resource allocation, accountability, and patient and provider autonomy. The benchmarks standardize the criteria for fairness. Reforms are then evaluated by scoring according to the degree to which they improve the situation, i.e. on a scale of -5 to 5, with zero representing the status quo. The object is to promote discussion about fairness across the disciplinary divisions that keep policy analysts and the public from understanding how trade-offs between different effects of reforms can affect the overall fairness of the reform. The benchmarks can be used at both national and provincial or district levels, and we describe plans for such uses in the collaborating sites. A striking feature of the adaptation process is that there was wide agreement on this ethical framework among the collaborating sites despite their large historical, political and cultural differences.

Benchmarking↗
PubMed2000

Implantable cardioverter defibrillators: arrhythmias. A rapid and systematic review.

PROPOSED SERVICE: The service proposed is the use of implantable cardioverter defibrillators (ICDs) in the management of risk factors leading to sudden cardiac death (SCD). ICDs are similar in size to a pacemaker and are intended to prevent death due to life-threatening ventricular tachyarrhythmias. EPIDEMIOLOGY AND BACKGROUND: SCD occurs in approximately 100,000 people annually in the UK and is usually due to ventricular tachyarrhythmia. Increasing numbers of people are surviving a first episode of ventricular tachyarrhythmia and are at high risk of further episodes. Standard treatments for those at high risk have been anti-arrhythmic drugs, catheter ablation or surgery and, increasingly, vasodilating beta-blockers. METHODS: Electronic databases were searched for the period 1980-99. In addition, bibliographies of related papers were assessed for relevant studies, and experts were contacted to identify additional published and unpublished references. Studies were included if they were systematic reviews, meta-analyses or randomised controlled trials (RCTs) comparing ICDs with conventional therapy in people at high risk of SCD. NUMBER AND QUALITY OF STUDIES AND DIRECTION OF EVIDENCE: Seven RCTs on effectiveness the majority of which were of good quality, eight cost-effectiveness analyses most of which were older studies and based on non-UK data, and two good-quality literature reviews one of which was a critical appraisal of the literature of effectiveness and cost-effectiveness of ICD therapy, and the other a review of the cost-effectiveness of ICD therapy. These showed changes in absolute risk of total mortality ranging from an increase of 1.7% to a reduction of 22.8% (relative risk reductions of -7% to +54%). SUMMARY OF BENEFITS: Estimated benefits from RCT data are 0.23-0.8 additional years of life with ICD therapy compared with anti-arrhythmic drug therapy. COSTS: Unit cost of ICDs (based on 1999/2000 prices), ranges from pound 12,500 to pound 22,000. Total discounted costs for 3 years range from pound 20,000 to pound 29,000. COST-EFFECTIVENESS: Cost-effectiveness estimates in the literature identified range from $11,000 to $146,000 per life-year saved. Using UK cost data from three hospitals and trial survival data from one RCT, the estimate of cost-effectiveness from this review ranges between pound 20,250 and pound 87,000 per life-year saved. COST-UTILITY: Cost per quality-adjusted life-year is estimated by the authors of this review at pound 21,300 to pound 108,800 (using survival data from one trial and quality-of-life indices derived from clinical opinion). These figures remain speculative until quality-of-life data from ongoing trials are available to inform future UK cost-effectiveness/utility analyses. IMPLICATIONS: If implemented for indications supported by evidence from RCTs, ICDs may cost the NHS in excess of pound 24 million per annum. FUTURE RESEARCH: Future research should include the use of British Pacing and Electrophysiological Group registries to assess the use of different types of ICD and current service provision.

Anti-Arrhythmia Agents↗
PubMed1999

Weighing the risks and benefits of tamoxifen treatment for preventing breast cancer.

BACKGROUND: In response to findings from the Breast Cancer Prevention Trial that tamoxifen treatment produced a 49% reduction in the risk of invasive breast cancer in a population of women at elevated risk, the National Cancer Institute sponsored a workshop on July 7 and 8, 1998, to develop information to assist in counseling and in weighing the risks and benefits of tamoxifen. Our study was undertaken to develop tools to identify women for whom the benefits outweigh the risks. METHODS: Information was reviewed on the incidence of invasive breast cancer and of in situ lesions, as well as on several other health outcomes, in the absence of tamoxifen treatment. Data on the effects of tamoxifen on these outcomes were also reviewed, and methods were developed to compare the risks and benefits of tamoxifen. RESULTS: The risks and benefits of tamoxifen depend on age and race, as well as on a woman's specific risk factors for breast cancer. In particular, the absolute risks from tamoxifen of endometrial cancer, stroke, pulmonary embolism, and deep vein thrombosis increase with age, and these absolute risks differ between white and black women, as does the protective effect of tamoxifen on fractures. Tables and aids are developed to describe the risks and benefits of tamoxifen and to identify classes of women for whom the benefits outweigh the risks. CONCLUSIONS: Tamoxifen is most beneficial for younger women with an elevated risk of breast cancer. The quantitative analyses presented can assist health care providers and women in weighing the risks and benefits of tamoxifen for reducing breast cancer risk.

Age Factors↗
PubMed1999

Ligand-dependent conformational equilibria of serum albumin revealed by tryptophan fluorescence quenching.

Ligand-dependent structural changes in serum albumin are suggested to underlie its role in physiological solute transport and receptor-mediated cellular selection. Evidence of ligand-induced (oleic acid) structural changes in serum albumin are shown in both time-resolved and steady-state fluorescence quenching and anisotropy measurements of tryptophan 214 (Trp214). These studies were augmented with column chromatography separations. It was found that both the steady-state and time-resolved Stern-Volmer collisional quenching studies of Trp214 with acrylamide pointed to the existence of an oleate-dependent structural transformation. The bimolecular quenching rate constant of defatted human serum albumin, 1.96 x 10(9) M-1 s-1, decreased to 0.94 x 10(9) M-1 s-1 after incubation with oleic acid (9:1). Furthermore, Stern-Volmer quenching studies following fractionation of the structural forms by hydrophobic interaction chromatography were in accordance with this interpretation. Time-resolved fluorescence anisotropy measurements of the Trp214 residue yielded information of motion within the protein together with the whole protein molecule. Characteristic changes in these motions were observed after the binding of oleate to albumin. The addition of oleate was accompanied by an increase in the rotational diffusion time of the albumin molecule from approximately 22 to 33.6 ns. Within the body of the protein, however, the rotational diffusion time for Trp214 exhibited a slight decrease from 191 to 182 ps and was accompanied by a decrease in the extent of the angular motion of Trp214, indicating a transition after oleate binding to a more spatially restricted but less viscous environment.

Acrylamide↗
PubMed1999

Radiotherapy review on national surgical adjuvant breast and bowel project (NSABP) phase III breast cancer clinical trials: is there a need for submission of portal/simulation films?

In all National Surgical Adjuvant Breast and Bowel Project (NSABP) breast cancer trials in which patients are treated with lumpectomy and postoperative breast irradiation, the quality assurance requirements dictate submission of a completed radiotherapy data form with the stated administered doses, the volumes treated, treatment prescription and daily treatment record sheets, dosimetry and calculation sheets, isodose distributions on the breast contour, photos of the patient in the treatment position, and portal or simulation films. A review of radiotherapy data on 1,982 patients who had lumpectomies accrued to seven recent NSABP breast cancer studies revealed only 2 patients who were judged to have inadequate fields. In both cases, a very small portion of the breast tissue was not included in the irradiated volume as demonstrated by the submitted films. On this basis, it was argued that submission of portal or simulation films for patients receiving postlumpectomy breast irradiation is not necessary. However, there was concern as to the incidence of patients with a possible excess amount of lung tissue included in the irradiated volume. To address this concern, the amount of irradiated lung was determined for the first 208 patients who had lumpectomies, with submitted data entered into the recent NSABP pathologic node-positive protocol B-28. Current NSABP radiation therapy guidelines suggest limiting the thickness of the irradiated lung in the portal beams to < or =3 cm. Only two patients (<1%) were found to have >3 cm of irradiated lung tissue in the treatment volume. Portal film submission is a considerable inconvenience to the individual institutions and is costly in terms of shipping, handling, and storage. These results indicate that submission of portal films is not a necessary part of quality assurance in NSABP breast cancer protocols. The NSABP has therefore eliminated the requirement for routine submission of portal films in protocols for which radiotherapy is not part of the test question.

Breast↗
PubMed1999

Doppler velocimetry in the fetus with a single umbilical artery.

OBJECTIVE: To study Doppler velocimetry in fetuses with a single umbilical artery (SUA) as compared to normal. STUDY DESIGN: Private and clinic patients were referred to a perinatal center: 45 with SUA and 124 randomly selected fetuses with a three-vessel cord were studied from 18 to 41 weeks' gestation. Color Doppler flow and energy were utilized to evaluate the umbilical arteries at the fetal abdominal wall as well as the course around the bladder. In addition to Doppler velocimetry, an anatomic survey, estimated fetal weight (EFW) and amniotic fluid index (AFI) were assessed at each examination. RESULTS: Doppler velocimetry in SUA demonstrated indices in the normal range but lower than in normal cords from 26 weeks until near term. Anatomic anomalies were found in 8.9% of SUA as compared to 4.8% for three-vessel cords. Intrauterine growth restriction (IUGR) was seen in four cases of SUA and none in the control group. EFW and AFI for both groups were virtually identical. CONCLUSION: SUA cords theoretically carry a normal blood volume, and the decreased resistance to flow and larger arterial diameter allow this to occur. Anomalies and IUGR are elevated in infants with SUA. Overall, EFW and AFI were the same in both groups of patients.

Abnormalities, Multiple↗
PubMed1999

The electronic learning zone in health informatics.

This paper outlines developments in health informatics education arising from the rapid development of the Internet and the growing importance of lifelong learning. The drivers for change in educational delivery are examined and examples of related uses of the Internet are given. The development of the Electronic Learning Zone at the University of Surrey is described and the paper concludes with the probable future extensions to support lifelong learning.

Computer-Assisted Instruction↗