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PubMed2004

Detection of immunoglobulin M antibodies specific for Toxoplasma gondii with increased selectivity for recently acquired infections.

Toxoplasma gondii infections can cause serious complications in pregnant women, leading to miscarriage, stillbirth, and birth defects. Definitive diagnosis of T. gondii acute infection is therefore critical for the clinical management of a mother and her fetus. Positive immunoglobulin M (IgM) results are not sufficient as evidence of recent infection, as these antibodies are often present for many months. Further, IgG avidity and differential agglutination tests, two tests used by reference laboratories to distinguish between recent and past infections, are not always in agreement, and both methods yield a significant number of indeterminate results. We report the development of a new toxoplasma IgM immunoassay that is performed by using a bead-based immunoassay on an automated analyzer (BioPlex 2200). Initial validation included 204 samples from pregnant women and 198 samples from asymptomatic healthy adults. An overall specificity of 99% was observed. Further, 100% sensitivity for acute infections was observed for 10 well-characterized seroconversion panels. We then examined 50 samples from pregnant women, all of which were IgM positive by ELISA, which had been fully evaluated in a reference laboratory. Of the 50 samples, 34 (68%) tested positive in the BioPlex 2200 toxoplasma IgM assay, of which 32 of 34 (94%) exhibited an acute or equivocal pattern by differential agglutination. Of the 16 negative samples, 15 (94%) showed high-IgG-avidity antibodies. Collectively, these results suggest that this new toxoplasma assay shows a preferential response to IgM antibodies produced by recent infections, reducing the number of positive results for pregnant women that will require extensive additional clinical evaluation.

Animals↗

PubMed2003

International Council for Standardization in Haematology (ICSH) recommendations for "surrogate reference" method for the packed cell volume.

The spun packed cell volume (PCV, hematocrit) is a key measurement on which are based hematology instrument calibration, reference range determination, and assignment of values to calibrators/controls. In 2001, the International Council for Standardization in Haematology (ICSH) recommended a Reference PCV method, which is fully traceable to the ICSH reference hemoglobin method. Because of its complexity, however, this method is impractical for occasional use in routine laboratories and is therefore intended primarily for use by manufacturers of capillary microhematocrit tubes, liquid calibrators, and multichannel analyzers. In response to the need for a simpler method--accessible to all routine laboratories--the ICSH offers this "Surrogate Reference" PCV procedure. It is traceable to the original ICSH Reference PCV method and is based on spun PCVs obtained using borosilicate capillary tubes with an already-known relationship to this reference procedure. This ICSH "Surrogate Reference" PCV method is substantially simpler, thus putting it within the reach of most routine hematology laboratories.

Blood Specimen Collection↗

PubMed2001

Race and the decision to refer for coronary revascularization: the effect of physician awareness of patient ethnicity.

OBJECTIVES: We sought to assess whether there were differences, relative to racial ethnicity, in coronary revascularization recommendations made by a panel that had no knowledge of the patients' ethnicity. BACKGROUND: Coronary revascularization is employed less frequently in African American than in white patients. It is unclear whether this utilization pattern is driven by clinical differences between the two populations or by nonclinical factors. METHODS: Data were reviewed from 938 (26.5% African American, 73.5% white) consecutive cardiac catheterizations done between 1993 and 1995. Revascularization recommendations were made by cardiologists and cardiothoracic surgeons provided with the patients' clinical and angiographic data, but without knowledge of their ethnicity. Revascularization recommendations were compared between African American and white patients and correlated with clinical characteristics. RESULTS: No difference was noted in the percentage of African American and white patients recommended for revascularization, without reference to whether the recommendation was for percutaneous transluminal coronary angioplasty (PTCA) or for coronary artery bypass graft surgery (CABG) 40 vs. 46%, p = NS). African Americans were recommended more frequently for PTCA (22 vs. 18%, p = NS), whereas CABG was recommended for more white patients (28 vs. 18%, p = 0.002). Significantly fewer African Americans had disease in the left main or left anterior descending coronary artery or in multiple arteries. After adjusting for age, co-morbidity, left ventricular dysfunction and the extent of coronary disease, African Americans were more likely to have a recommendation for PTCA (odds ratio [OR] 1.42, 95% confidence interval [CI] 0.96 to 2.11, p = 0.08) and less likely to have a recommendation for CABG (OR 0.59, 95% CI 0.37 to 0.94, p = 0.02). CONCLUSIONS: This study suggests that when only clinical factors are considered, the rates of recommendations for revascularization will be similar for white and African American patients; but the type of revascularization procedure may differ by ethnicity and may depend, in part, on clinical factors.

Black or African American↗

PubMed2000

Should assisted suicide be only physician assisted? University of Pennsylvania Center for Bioethics Assisted Suicide Consensus Panel.

Discussions in the media, courts, legislatures, and professional societies generally assume assistance with suicide to be a physician's task; in these venues it is commonly referred to as "physician-assisted suicide." This paper defines both the necessity and the limits of the physician's role in assisted suicide by asking the question: Should assisted suicide be only physician assisted? Although physician involvement is necessary, we argue that it is not sufficient to ensure that patients requesting assisted suicide receive the best care. Assisted suicide requires physician involvement, but physicians' limited competence in performing the full range of tasks, the competencies of other professions, and the possibility that other professions could expand their authority in this area suggest that physician-assisted suicide is a far too narrow construct of the task. The willingness of other professionals--including nurses, social workers, and clergy--to participate and even take the lead in assisting suicides is critical to meet society's interest that assisted suicide should be humane, effective, and confined to appropriate cases. As long as legislation and guidelines focus exclusively on the physician's role, our laws and regulations will fall short of meeting societal expectations.

Ethics, Medical↗

PubMed2001

Preimplantation genetic diagnosis of the fragile X syndrome by use of linked polymorphic markers.

Fragile X syndrome is the most common cause of familial mental retardation. The most common mutation is expansion of a triplet (CGG)(n) repeat in the 5' untranslated region of the FMR1 gene on Xq27.3. The expansion is refractory to PCR due to preferential amplification of the smaller allele in heterozygous cells and the high GC content of the repeat and surrounding sequences. Direct detection of the normal parental alleles in preimplantation embryos has been used for preimplantation genetic diagnosis (PGD) of this disorder. However, this approach is only suitable for approximately 63% of couples due to the heterozygosity of the repeat in the normal population. As an alternative we investigated the use of polymorphic markers flanking the mutation to track the normal and premutation carrying maternal chromosomes in preimplantation embryos. Using a panel of 11 polymorphisms, six (CA)(n) repeats and five single nucleotide polymorphisms, diagnosis was developed for 90% of referred couples. Multiplex amplification of informative markers was tested in 300 single buccal cells from interested couples with efficiency and allele drop out (ADO) rates ranging from 69% to 96% and 6% to 18%, respectively. Use of this approach is accurate and applicable to a larger number of patients at risk of transmitting fragile X to their offspring.

Adult↗

PubMed1991

A somatic cell hybrid panel and DNA probes for physical mapping of human chromosome 7p.

To identify by reverse genetics genes on the short arm of human chromosome 7 expected to be involved in the regulation of human craniofacial and limb development, we have set up a human mouse somatic cell hybrid panel that divides 7p into 9 fragments. The breakpoints are defined by deletions or translocations involving one chromosome 7 in the cells of the human cell fusion partners. Particularly densely covered with these cytogenetic anchor points is the proximal area of 7p within and around 7p13. The number of cytogenetic mapping points within proximal 7p could be increased by four, using two diploid human cell lines with small interstitial deletions in this region for dosage studies. We used Southern blots of this panel to assign to 7q or subregions of 7p more than 300 arbitrary DNA probes or genes that provide reference points for physical mapping of 7p. Three reciprocal translocations with one of the breakpoints in 7p13 mark the location of a gene involved in Greig cephalopolysyndactyly syndrome. To define an area in which we could identify candidates for this developmental gene, we established a macrorestriction map using probes flanking the putative gene region. The Greig translocations were found to be located within a 630-kb NotI restriction fragment.

Animals↗

PubMed2004

Synthesis and antiproliferative activity of 3-aryl-2-[1H(2H)-benzotriazol-1(2)-yl]acrylonitriles variously substituted: Part 4.

A new series of variously substituted 3-aryl-2-[1H(2H)-benzotriazol-1(2)-yl]acrylonitriles was synthesized and tested for antiproliferative and antitubercular activity as part of our continuing research program in the antimicrobial and antitumor fields. The most cytotoxic derivatives (5a,g,i,j,l and 7b) (CC50 < 3.0 microM against MT-4 cells) were evaluated against a panel of human cell lines derived from hematological and solid tumors, using 6-mercaptopurine (6-MP) and etoposide as reference drugs. In particular, E-2-(5,6-dimethyl-1H-benzotriazol-1-yl)-3-(3-nitrophenyl)acrylonitrile (5g) resulted more potent than 6-MP on all cell lines, even if 2-14-fold less potent than etoposide. In the antitubercular screening, the derivatives 5i,j and 7e showed moderate activity against some resistant strains of Mycobacterium tested.

Acrylonitrile↗

PubMed2005

Studying individual aging in an interindividual context: typical paths of age-related, dementia-related, and mortality-related cognitive development in old age.

This study has 2 objectives: (a) to explore typical paths of cognitive development associated with aging, terminal decline, and dementia and (b) to promote and illustrate an individual-oriented approach to the study of cognitive aging based on longitudinal panel data from a population-based sample (N = 500; age range-sub(T1)= 60-80, where T refers to time) tested at 3 occasions 5 years apart. Results document interindividual differences in multivariate patterns of change. Although cognitive changes generally covary, the present study indicates that subgroups of individuals develop along different paths characterized by selective changes in subsets of cognitive functions. Typical progression of dementia followed a developmental cascade from low declarative memory, via low functioning across all observed cognitive measures, to dementia diagnosis, and finally, death.

Aged↗

PubMed2002

Detection of antibodies to human immunodeficiency virus (HIV) that recognize conformational epitopes of glycoproteins 160 and 41 often allows for early diagnosis of HIV infection.

On the basis of human immunodeficiency virus (HIV) needlestick studies, the time to seroconversion for anti-HIV antibodies is 1-9 months (mean, approximately 2-3 months). However, an earlier marker of an immune response to HIV often occurs-serum anti-HIV antibodies reactive with live HIV-infected cells, termed "early HIV antibodies." The specificities of these antibodies are characterized by the recognition of type-specific conformational epitopes of the HIV envelope glycoprotein (gp) 160 and gp41. By use of a third-generation native HIV(IIIB) gp160 enzyme immunoassay (EIA), detection of HIV antibodies occurred, on average, 33 days earlier than did detection by commercial EIA and 25 days earlier than did detection by the reference antigen and reverse-transcription polymerase chain reaction (RT-PCR) assays in 3 of 5 HIV seroconversion panels. A fourth panel possessed early HIV antibodies that reacted with HIV(213) but not with HIV(IIIB), allowing for detection of HIV antibodies approximately 3 weeks earlier than by RT-PCR or other current tests.

Blotting, Western↗

PubMed1988

A new second-generation anti-HIV-1 enzyme immunoassay using recombinant envelope and core proteins.

In a multicenter collaborative study a new second-generation HIV-1 antibody enzyme immunoassay (Abbott recombinant HIV-1 EIA) using Escherichia coli-expressed recombinant p24 and p41 proteins as solid-phase antigens was compared with the first-generation H9 cell-line-based Abbott HIV-1 EIA. The results of the confirmatory assays (Western blot, immunofluorescence), combined with clinical information, were used as the reference standard for the detection of HIV-1 antibodies in 10,676 random blood donor serum specimens, in a panel of 840 specimens from symptomatic and asymptomatic patients and a total of 63 serial blood specimens from 23 people at risk. With fresh blood donor sera, the specificity of the first-generation assay ranged between 99.54 and 99.76% (95% confidence limits, CL) compared with 99.81-99.95% (95% CL) for the second-generation EIA. With panel specimens the recombinant HIV-1 EIA achieved an overall sensitivity of 100% and a specificity range of 98.3-99.7% (95% CL); the corresponding sensitivity and specificity ranges observed for the first-generation EIA were 98.0-99.5% (95% CL) and 94.3-96.8% (95% CL), respectively. The improved sensitivity for the second-generation assay was confirmed by testing serial samples from seroconverting patients. The use of recombinant proteins eliminated non-specific reactions due to class II human leukocyte antigen (HLA)-directed antibodies.

Blood Donors↗

PubMedDate not supplied

Good research practices for cost-effectiveness analysis alongside clinical trials: the ISPOR RCT-CEA Task Force report.

OBJECTIVES: A growing number of prospective clinical trials include economic end points. Recognizing the variation in methodology and reporting of these studies, the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) chartered the Task Force on Good Research Practices: Randomized Clinical Trials-Cost-Effectiveness Analysis. Its goal was to develop a guidance document for designing, conducting, and reporting cost-effectiveness analyses conducted as a part of clinical trials. METHODS: Task force cochairs were selected by the ISPOR Board of Directors. Cochairs invited panel members to participate. Panel members included representatives from academia, the pharmaceutical industry, and health insurance plans. An outline and a draft report developed by the panel were presented at the 2004 International and European ISPOR meetings, respectively. The manuscript was then submitted to a reference group for review and comment. RESULTS: The report addresses issues related to trial design, selecting data elements, database design and management, analysis, and reporting of results. Task force members agreed that trials should be designed to evaluate effectiveness (rather than efficacy), should include clinical outcome measures, and should obtain health resource use and health state utilities directly from study subjects. Collection of economic data should be fully integrated into the study. Analyses should be guided by an analysis plan and hypotheses. An incremental analysis should be conducted with an intention-to-treat approach. Uncertainty should be characterized. Manuscripts should adhere to established standards for reporting results of cost-effectiveness analyses. CONCLUSIONS: Trial-based cost-effectiveness studies have appeal because of their high internal validity and timeliness. Improving the quality and uniformity of these studies will increase their value to decision makers who consider evidence of economic value along with clinical efficacy when making resource allocation decisions.

Advisory Committees↗

PubMedDate not supplied

Genetic analysis of Giardia from hoofed farm animals reveals artiodactyl-specific and potentially zoonotic genotypes.

Thirty one Giardia isolates, established from six species of hoofed livestock by axenic culture or growth in suckling mice, were compared genetically by analysis of DNA amplified from loci encoding variant surface proteins or the enzyme glutamate dehydrogenase and by allozyme analysis. The isolates were heterogeneous, but all showed affinity with genetic Assemblage A--one of two major assemblages defined previously by analysis of Giardia from humans. Three distinct genotypes were evident. Ten isolates (eight axenic and two established in suckling mice) from an alpaca, pig, horse, cattle and sheep were indistinguishable from human-derived G. intestinalis belonging to a previously designated genetic group (Group I). This genotype seems to have broad host specificity, including a zoonotic potential for humans. Five isolates (two axenic and three established in suckling mice) from an alpaca, a horse and sheep had close affinity with human-derived Group I and Group II G. intestinalis genotypes. The other 16 isolates (comprising both axenic and suckling mouse-propagated cultures derived from cattle, sheep, alpaca, a goat and pigs in Australia and Europe) differed from all other Giardia with "duodenalis" morphology that have been examined by these methods and they segregated as a highly distinct sublineage (referred to herein as 'Novel livestock') within genetic Assemblage A. The predominance of 'Novel livestock' genotypes in the test panel and their apparent exclusive association with artiodactyl hosts indicates that they may be confined to this group of mammals. Assemblage B genotypes, which are prevalent in humans and some other animal species, were not detected.

Animals↗

PubMed1992

Comparison of relative uses of commercial assays for Toxoplasma gondii IgM antibodies.

AIMS: To compare the sensitivity and user friendliness of seven commercially available enzyme linked immunoabsorbent assay (ELISA) kits for toxoplasma specific IgM. METHODS: Five antibody capture assays supplied by Abbott, Mercia, Northumbria, Organon and Sorin, and two indirect ELISA assays from Biostat and Mast, were assessed. Using defined dilutions of Toxoplasma gondii specific IgM, the performance and sensitivity of each assay was established. They were further assessed on a panel of 27 sera with a range of dye test and IgM results (as determined by the Scottish Toxoplasma Reference Laboratory). All of the assays were performed by three experienced operators and assessed for user satisfaction. RESULTS: The Mast, Organon, and Abbott assays were of low sensitivity; the Mercia and Northumbria were of high sensitivity; and the Biostat and Sorin assays produced too many false positive results. The Mercia kit provided most user satisfaction; the Mast and Abbott assays were most difficult to use. CONCLUSIONS: Local laboratories investigating toxoplasma infection should have three tests: one IgG and two IgM (high and low sensitivity) to help in the timing of infection. Alternatively, one sensitive IgM assay, such as that of Mercia, could be used by selecting appropriate high and low thresholds.

Animals↗

PubMedDate not supplied

Mapping the SF-12 to the EuroQol EQ-5D Index in a national US sample.

BACKGROUND: Preference scores for the Medical Outcomes Study (MOS) SF-12 would enable its use in cost-effectiveness analyses. Previous mapping studies of MOS instruments top reference-based instruments have not examined performance in national samples. PARTICIPANTS: 15,000 adults in the 2000 Medical Expenditure Panel Survey annual survey including the SF-12 and EQ-5D Index. METHODS: Regression of the EQ-5D Index scores onto the physical and mental component summary scores of the SF-12, testing 2nd-4th degree polynomial and spline models, including and excluding sociodemographics. RESULTS: A 2nd degree polynomial model explained 63% of the variance in EQ-5D scores, with robust internal and external validation. More complex mod-els explained minimally additional variance. Compared with EQ-5D valuations, prediction models overestimated the lowest health states (6% of the population). CONCLUSIONS: The mapped SF-12 yields usable preference-scaled scores, with some caution for the lowest health states.

Adult↗

PubMed2006

Fatigue in frail elderly people.

Many frail older people are likely to suffer from fatigue, but tools to measure fatigue in this population are lacking. Stage one of this study explored and described the experiences of fatigue of 12 older people from Australian residential aged care facilities. Themes identified were pacing yourself, battling on, hitting rock bottom, feeling safe, and moving on. Findings indicated that, with support, frail elders may be able to manage fatigue effects themselves. A measure of fatigue was developed from stage one findings, with reference to the literature. In stage two of the study, the Frail Elder Fatigue Assessment Tool was subjected to panel review, piloting, and refinement. The refined tool comprises 20 items in three subscales: fatigue effects; fatigue resources; and adaptation to fatigue. Further work is required to establish the tool's psychometric properties, but it should then be useful for both research and clinical assessment purposes.

Activities of Daily Living↗

PubMed1992

Why does the injured drunk driver escape arrest and conviction? A case presentation and discussion by health care and law enforcement professionals.

Serious injury protects the drunk driver from prosecution and conviction for driving drunk. This escape from liability occurs despite the fact that almost half of all traffic fatalities are attributable to alcohol. Consequently, the drunk driver who is injured may resume driving as soon as he is physically able to do so, thereby becoming a renewed threat to himself and others. On the other hand, a conviction for driving while impaired (DWI) results in loss of the driving privilege, reducing exposure of other drivers to a public health hazard. A DWI conviction may also stimulate the drunk driver to seek treatment for alcoholism. Unless they are prosecuted, even seriously injured drunk drivers are seldom referred for alcoholism counseling or treatment. To explore the reasons for this continuing cycle of impairment and injury, a panel of experts from the fields of health care and law enforcement was convened on October 30, 1991, during the Third Annual North Carolina Conference on Injury Control. The panel considered the hypothetical case of an alcohol-related motor vehicle crash in which a passenger was killed. We present here an edited transcript from that conference.

Accidents, Traffic↗

PubMed2004

Performance of blood tests in diagnosis of inflammatory bowel disease in a specialist clinic.

AIMS: To determine the reliability of a panel of blood tests in screening for ulcerative colitis and Crohn's disease. METHODS: The subjects were 153 children referred to a paediatric gastroenterology department with possible inflammatory bowel disease (IBD). Of these, 103 were found to have IBD (Crohn's disease 60, ulcerative colitis 37, indeterminate colitis 6). The 50 without IBD formed the controls. Blood tests evaluated included haemoglobin, platelet count, ESR, CRP, and albumin. Receiver operating characteristic curves were used where possible to determine optimal threshold values. Binary logistic regression analysis was used to investigate the five screening tests in combination, and a stepwise method was used to find the best test combination. RESULTS: The optimal screening strategy used a combination of haemoglobin and platelet count and "1 of 2 abnormal" as the criterion for positivity. This was associated with a sensitivity of 90.8% (95% CI 83.3 to 95.7%), a specificity of 80.0% (95% CI 65.7 to 89.8%), and positive and negative predictive values of 94.4% and 75.9% respectively. CONCLUSIONS: Haemoglobin and platelet count provide a useful screening test combination for patients with suspected IBD. These tests are not completely reliable however. If clinical suspicion is high further investigations are required.

Adolescent↗

PubMed1995

Population norms for serum ferritin.

The purpose of this study was to establish norms for the serum ferritin determination. Analyses of blood samples submitted for a panel of 29 laboratory tests in 964,325 individuals of a random population of all races in 10 centers in the United States were used. A subgroup of 59,914 ferritin values was constituted from panels that showed the values of the 28 other laboratory tests inside prescribed limits that approached the conventionally used reference ranges. The selected group was taken to be more representative of normal ferritin values than the total group, because in the former group the accompanying 28 other test parameters approached normalcy. Although both groups showed a log-normal distribution of serum ferritin values, the values of the selected group were somewhat lower than those of the total population group. The percentile distribution for men and women of different ages is portrayed. In males, the median ferritin level increased from 23 micrograms/L at ages 12 through 16 years to reach a plateau in the 120s after age 32. Values in females remained in the 30s until menopause, after which values rose to about 80 micrograms/L. The validity of these data and their clinical significance are discussed.

Adolescent↗