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PubMed2004

The value of crossmatch tests and panel tests as a screening tool to predict the outcome of platelet transfusion in a non-selected haematological population of patients.

BACKGROUND AND OBJECTIVES: Alloantibodies against platelets can be detected by using different laboratory tests. Most of these tests, which use panel cells or antigens as a target, perform poorly in non-selected haematological patients. In relation to these tests, a crossmatch test of transfused platelets and patient's serum may be viewed as the standard and may be superior in predicting donor platelet destruction by alloimmunization. MATERIALS AND METHODS: In 95 randomly selected thrombocytopenic patients with haematological malignancies, who were receiving leucodepleted blood products, 184 serum samples were studied in an in vitro crossmatch test by using the technique of the platelet immunofluorescence test (crossmatch-PIFT), in an in vivo crossmatch test detecting in vivo binding of immunoglobulins to transfused platelets according to the PIFT technique (in vivo-PIFT), in the indirect PIFT using five random donors as a target (panel-PIFT) and in an enzyme linked immunosorbent assay using immobilized human leucocyte antigens (HLAs) of 100 standardized donors (ELIHLA). The results of all these methods were related to the recovery at 1 and 16 h post-transfusion. RESULTS: The results of the crossmatch-PIFT were not associated with platelet recovery at 1 and 16 h after transfusion. Even in a subgroup of patients, in whom predefined clinical factors were excluded, no association with platelet recovery was found. The results of the crossmatch-PIFT correlated with those of the in vivo-PIFT (P = 0.02); however, 35 (19%) discrepant results were identified between these tests. The results of the crossmatch-PIFT were not related to the panel-PIFT (P = 0.25), but did relate to those of the ELIHLA (P = 0.02), still revealing 36 (20%) discrepant results. None of the in vivo-PIFT, the panel-PIFT or the ELIHLA was associated with platelet recovery after 1 h, whilst only a positive panel-PIFT was associated with poor platelet recovery at 16 h after transfusion (P = 0.03). CONCLUSIONS: In a population at low risk for alloimmunization, the correlation of test outcome and platelet recovery is poor. None of these crossmatch tests or screening tests was identified as superior to any other in this population.

Antigen-Antibody Reactions↗

PubMed2003

Evaluating the response of patients undergoing both allergy skin testing and in vitro allergy testing with the ImmunoCAP Technology System.

PURPOSE: To evaluate the response of patients who underwent both skin and in vitro allergy testing, both of which are accepted methods. DATA SOURCES: Retrospective review of the case notes of 100 patients evaluated by both testing methods for allergic disease. CONCLUSIONS: A total of 62 patients (62%) tested positive to at least one of the tested allergens via the in vitro method. A total of 65 patients (65%) tested positive to at least one allergen via the skin-testing method. The most frequently elicited allergic response from the in vitro method was to white oak. Indoor mold and dust most frequently elicited response via skin testing. IMPLICATIONS FOR PRACTICE: Both in vitro and in vivo allergy testing have limitations. Practitioners should be aware of these when establishing a treatment plan based on the results of differing allergy testing methods. Due to differing responses to skin and in vitro testing methods, it may be prudent to perform both tests to obtain a definitive diagnosis for the allergic patient.

Allergens↗

PubMed1983

The effect of test difficulty on the sensitivity of speech discrimination tests.

The sensitivity of speech discrimination tests is defined as being large if a small change in experimental conditions causes a large and repeatable change in test score. The aim of this paper is to investigate ways by which test sensitivity can be maximized. The effect of test difficulty on sensitivity is examined by the use of a model based on signal detection theory and subjective similarity rating concepts. For several sets of assumptions about the parameters underlying the perceptual processes, the model indicates that test difficulty should be in the range 73% to 87% to achieve the maximum sensitivity with speech tests using between four and eight response foils. The model results also indicate that the sensitivity increases with the number of response foils. When the variation of test reliability with test difficulty is taken into account, the test difficulty which maximizes the sensitivity/reliability trade-off lies in the range 85% to 90%. It is argued that irrespective of the optimum test difficulty, a maximally sensitive test will contain items equal to one another in difficulty.

Humans↗

PubMed1991

Evaluation of the E test for quantitative antimicrobial susceptibility testing of Helicobacter pylori.

The Progressive Diagnostics Manufacturers epsilometer test (E test; AB Biodisk, Solna, Sweden), a quantitative variant of the disk diffusion technique, was evaluated comparatively to an agar dilution method for the antimicrobial susceptibility testing of Helicobacter pylori. A collection of 79 H. pylori clinical strains, including isolates with known resistance to various antimicrobial agents, was tested against 12 different antimicrobial agents. All strains were tested on Columbia agar supplemented with 10% horse blood. Plates were incubated at 37 degrees C in microaerobic atmosphere (5% O2, 10% CO2), and readings were done after 3 days of incubation. In general, E test MICs were easy to interpret and the correlation between MICs by the agar dilution method and the E test was good, with 86 and 99.5% of results being within, respectively, 1 and 2 log2 dilution steps in a total of 936 tests. All strains of H. pylori with documented resistance to the tested agents were detected by the E test. Thus, the E test appears to be an easy and reliable method for determination of MICs of antibiotics for H. pylori, and it may offer an interesting alternative to MIC determination by the agar dilution technique.

Drug Resistance, Microbial↗

PubMed1992

Detection of enterotoxigenicity of Staphylococcus aureus strains: a comparative use of the modified Ouchterlony precipitation test, reversed passive latex agglutination test, and avidin-biotin ELISA.

The avidin-biotin enzyme-linked immunosorbent assay (ELISA), reversed passive latex agglutination (RPLA) test, and the modified Ouchterlony precipitation test (MOPT) were compared in detecting enterotoxin production by Staphylococcus aureus strains. A total of 1015 strains isolated from human beings, animals, and foods were tested for staphylococcal enterotoxins A (SEA), B (SEB), and C (SEC). Of these, 495 (48.8%), 467 (46.0%), and 204 (20.1%) were classified as enterotoxigenic by the ELISA, RPLA test, and MOPT, respectively. The difference in the number of strains classified as enterotoxigenic by the ELISA and RPLA test was not significant (P > or = 0.05; chi 2), but both tests detected significantly (P < 0.001; chi 2) more enterotoxigenic strains than the MOPT. The combined use of the three assay systems classified 258 (25.4%), 278 (27.4%), and 263 (25.9%) of 1015 strains tested as positive for SEA, SEB, and SEC, respectively. However, the three systems were all positive in only 29.1% of SEA-producing strains, 32.0% of SEB-producing strains, and 25.1% of SEC-producing strains. The MOPT was negative when the corresponding ELISA and RPLA test were positive (46.9% for SEA, 43.5% for SEB, and 40% for SEC); the RPLA test was negative when the corresponding ELISA was positive (10.5% for SEA, 15.5% for SEB, and 25.5% for SEC); and the ELISA was negative when the RPLA test was positive (13.6% for SEA, 9.0% for SEB, and 9.5% for SEC). All factors considered, the RPLA test appears most suitable for quantitatively screening large numbers of strains for staphylococcal enterotoxins.

Animals↗

PubMed2000

Prediction accuracy and financial savings of four screening tests for a sequential test of clinical performance.

BACKGROUND: Sequential testing of clinical performance is an effective strategy to reduce cost of testing. PURPOSE: To evaluate prediction accuracy and financial savings of 4 screening tests of clinical performance. METHODS: Screening tests were created from a 13-case examination taken by 434 medical students at 4 schools. Regression analysis determined prediction accuracy for 2 test outcomes. Financial savings were computed from published estimates. RESULTS: Zero false passes were obtained with the "Total Number of Cases Passed" screening test, but it saved only 27%. Sixty-two percent savings with 5% false passes occurred with the "Classification" screening test. The "Scale" and "Mini Test" screening tests would have excused 79% and 67% examinees with 5% and 1% false passes, respectively. CONCLUSIONS: Prediction accuracy varies with screening test and outcome measure. Sequential testing of clinical performance can save 40% to 60% with low false pass rates. However, programs need to consider loss of information for curriculum and individual feedback relative to financial savings.

Clinical Competence↗

PubMed2005

Comparison of adrenal function tests in children--the glucagon stimulation test allows the simultaneous assessment of adrenal function and growth hormone response in children.

The accurate assessment of adrenal function is necessary in many children with suspicion of pituitary insufficiency. The objective of this study was to evaluate the adrenal response during the glucagon stimulation test (GST) and its diagnostic utility in children. A total of 290 children, aged 10.1 +/- 5.0 years, were evaluated for adrenal function using the corticotrophin releasing hormone (CRH) test, the GST, and/or the insulin tolerance test (ITT). Glucagon stimulation provoked a substantial rise in cortisol and adrenocorticotropin (ACTH) that was independent of gender, age, or underlying growth hormone deficiency. There were no differences in peak cortisol levels in the GST compared to the CRH test in pair-wise intra-individual analyses in children with both tests performed within one year (615.4 +/- 30.5 vs 602.8 +/- 22.4 nmol/l, n=52). Similarly, there were no differences in the cortisol response between the ITT and CRH test. Peak cortisol levels in the CRH test correlated with the GST and the ITT. The magnitude of ACTH response, in contrast, was highest in the ITT with a 9.8-fold increase over baseline, while the increase in the GST (3.1-fold) and CRH test (1.6-fold) were more subtle. Since there is controversy concerning reliable cut-off values for adrenal function tests in children, we analyzed cut off levels in 186 children, including 26 children with adrenal insufficiency, using the CRH test. A peak cortisol level of 450 nmol/l provided the best balance of sensitivity (88.5%) and specificity (86.8%), while higher cut-off levels did not increase sensitivity but lost in specificity. In summary, the GST constitutes an1 equally sensitive test for the assessment of adrenal function in children that is not confounded by anthropometric parameters and is generally not accompanied by major side effects. It allows the simultaneous assessment of corticotroph and somatotroph function and may thus constitute a valuable alternative to the ITT.

Adolescent↗

PubMed1997

Test of visual-motor integration:: construct validity in a comparison with the Beery-Buktenica Developmental Test of Visual-Motor Integration.

The 1996 Test of Visual-Motor Integration manual states that an adjusted correlation of .95 was obtained between this test and the Beery-Buktenica Developmental Test of Visual-Motor Integration for 49 children with an average age of 9 years and that the adjusted .95 suggests equivalency of the tests. In the present study, for 103 children whose average age was 9 years, there was a correlation of .33 between the tests. Scores on the Beery-Buktenica test correlated more strongly than the Test of Visual-Motor Integration with both chronological age and academic achievement. Standard scorers for the latter test were high compared to those of the Beery-Buktenica test and the Comprehensive Test of Basic Skills. Interscorer agreement was significantly lower, and more time was required to score the protocols. This study indicates that the 1996 version is not a substitute for the Beery-Buktenica test.

Achievement↗

PubMed2002

Relation of test-specific motivation and anxiety to test performance.

The relations between consequence of test scores and motivation, anxiety, and test performance were studied with 112 persons in four undergraduate educational psychology courses. Students were given two versions of an hourly course examination that varied in consequence, with one counting for part of their grade and the other not counting. Each student completed the Learning and Study Strategies Inventory prior to taking the examination. Afterwards students completed a measure of test anxiety and test motivation specific to the examination they had just taken. Significant main effects were found for consequence of test with scores for test anxiety, test performance, and test motivation. Also, the subscales showed a consistent pattern of relations with test performance and test anxiety across the two conditions, but not for test motivation for which few relations were found under the condition with no consequence.

Adult↗

PubMed1991

Comparative study of computerized trapezoid rotation test and sinusoidal harmonic acceleration test.

By using the Contraves computerized rotary chair system, trapezoid rotation (TR) test and sinusoidal harmonic acceleration (SHA) test were performed on each subject on the same day. The results in 25 normal volunteers and 145 patients with peripheral vestibular disorders were as follows: 1) As regards directional preponderance, the results of two rotation tests agreed in 75.9% of all patients, but a discrepancy was found in the rest. Abnormality was detected by TR test in 57.2% of all patients, and, less frequently, in 45.5% by SHA test. 2) In normal subjects, the maximum slow phase velocity of nystagmus provoked by TR test was greater than that of nystagmus provoked by SHA test using angular acceleration of a magnitude comparable to that in TR test. 3) As to the detection of abnormal VOR gain, the results of two rotation tests agreed in 100% of patients with bilateral vestibular disorders. However, in patients with unilateral vestibular disorders, the detection rate was higher for SHA test than that for TR test.

Acceleration↗

PubMed1976

Quantitative cell culture biocompatibility testing of medical devices and correlation to animal tests.

The biocompatibility of a wide variety of biomaterials was quantitatively assessed, in a physiologically normal environment" as to cytotoxicity induced in WI-38 cells by cell culture medium extracts. Materials tested included PVC plastic, rubber, silicone rubber, polyethylene, polypropylene, acetal, polyurethane, Teflon, nylon, epoxy, and polystyrene. Cell culture test results were correlated to U.S.P. animal tests. Potential test artifacts, lead, barium, cadmium, and endotoxin were tested for cytotoxicity in WI-38 cells. Cell culture methods yielded more positive tests, particularly rubber, PVC plastic and silicone rubber compounds, than observed in U.S.P. animal tests. Positivity in animal tests did not correlate quantitatively to cytotoxic titers in cell culture. Discrepancies between cell cultures tests and animal tests, specifically rubber compounds, were attributable, in some instances, to differentials in elution efficiency between saline, cottonseed oil, and complete MEM cell culture medium. In other instances, particularly PVC plastics, differences between cell culture and animal test results were due to an inherent difference in the two indicator systems to respond to specific toxic moieties.

Acetals↗

PubMedDate not supplied

A case-control study evaluating occult blood screening for colorectal cancer with hemoccult test and an immunochemical hemagglutination test.

A case control study to evaluate the occult blood screening for colorectal cancer was conducted in a town where colorectal cancer screening had been performed by Hemoccult test during the early years and subsequently by an immunochemical hemagglutination test. All residents aged >/=40 years had been offered the annual screening. Case series consisted of 51 subjects with fatal colorectal cancer. Three controls per case were selected from the list of residents who were alive at the time of diagnosis of the corresponding case and had been living in the town, matched by gender and by age. The odds ratio (OR) of dying of colorectal cancer for those having their most recent screening histories with Hemoccult test or the immunochemical test during the preceding 1 year and 1-2 year segment before case diagnosis were 0.20 [95% confidence interval (CI): 0.08-0.49] and 0. 17 (95% CI: 0.04-0.75), respectively. The OR increased towards 1.0 as the number of years since the most recent screening increased. The OR of dying of colorectal cancer was calculated to be 0.19 (95% CI: 0.05-0.70) for those screened with the immunochemical test alone during the preceding 1 year after adjustment for previous screening histories with the Hemoccult test. Corresponding OR was 0.36 (95% CI: 0.11-1.17) for those screened with Hemoccult test during the preceding 1 year. These results suggest that screening for colorectal cancer by fecal occult blood testings or immunochemical test alone would reduce mortality and that efficacy of the screening would be higher for the immunochemical test than for Hemoccult test.

Case-Control Studies↗

PubMedDate not supplied

Comparison of the clock test and a questionnaire-based test for screening for cognitive impairment in Nigerians.

BACKGROUND: Since it is projected that by 2020 seventy percent of the elderly will reside in developing countries, a reliable screening method for dementia and cognitive impairment in general in populations with diverse languages, culture, education and literacy will be needed. We sought to determine if the Clock Test, a screening test for dementia, was suitable for use in a Nigerian population. STUDY DESIGN: Cross-sectional survey of 54 men and 12 women from Northern Nigeria. Researchers administered two dementia screening tools: a questionnaire-based test adapted for use in a Nigerian population and the Clock Test. RESULTS: Overall, 53.0% of the subjects had an abnormal Clock Test whereas 10.6% of the subjects had an abnormal questionnaire score. Only 9.1% of the subjects had abnormal scores on both tests. Subjects with more schooling had a greater probability of having a positive clock concept (understanding that a circle represented a clock). Of those with more than 6 years of schooling, 91.0% had a positive clock concept. Subjects with a negative clock concept were more likely to have an abnormal Clock Test (93.3%) than a questionnaire (26.6%). CONCLUSIONS: The main finding of our study was the discrepancy between the results of the Clock Test and the questionnaire. Performance on the Clock Test appeared to have been heavily influenced by education level, indicating the test is not universally applicable across cultures. The questionnaire-based test appears to reduce the effects of illiteracy on assessing dementia in a Nigerian population. Larger studies should be done to control for how education affects the assessment of dementia.

Aged↗

PubMed2002

[Fecal elastase-1 test: clinical evaluation of a new noninvasive pancreatic function test].

UNLABELLED: We evaluated clinical significance of fecal elastase-1(FE-1) in patients with pancreatic diseases and pancreatic dysfunction, in comparison with other tubeless test and secretin test. PATIENTS AND METHODS: FE-1 was determined in healthy controls(n = 131), chronic pancreatitis(CP) (n = 52), acute pancreatitis(AP) (n = 14), pancreatic cyst(Pcyst) (n = 20), pancreatic cancer(Pca) (n = 12), post pancreatic surgery(post P) (n = 28), biliary diseases(B) (n = 6), and gastro-duodenal ulcer(G) (n = 6). Fecal chymotrypsin(FCT) and BT-PABA test were performed in those patients digestive diseases. Secretin test collecting duodenal juice through a duodenal tube was performed in only 65 patients described above. RESULTS: FE-1 was 1504 +/- 100 micrograms/g(M +/- SE) in healthy controls. Using a cut off of 200 micrograms/g, 94.6% for healthy controls had FE-1 above this limit. FE-1 was 517 +/- 106 micrograms/g in CP, 1802 +/- 437 micrograms/g in AP, 525 +/- 109 micrograms/g in Pcyst, 528 +/- 126 micrograms/g in Pca, 135 +/- 36 micrograms/g in post P, 1435 +/- 506 micrograms/g in B, and 1115 +/- 325 micrograms/g in G, respectively. Sensitivity in the diagnosis of CP was 51.9%, 46.2% and 54.8% for FE-1, FCT, and BT-PABA test, respectively. Specificity of FE-1 and FCT was 81.3% and 78.7%, while that of BT-PABA test was 44.4%. Significant correlation was observed between FE-1 and secretory data including juice volume, maximum HCO3- concentration, and amylase output obtained form secretin test. In diagnosis of severe pancreatic dysfunction classified based on secretin test, the sensitivity was 86.7% for FE-1, 66.7% for FCT, and 66.7% for BT-PABA test. The specificity was also 70.0%, 80.0%, and 54.3%, for FE-1, FCT, and BT-PABA test, respectively. CONCLUSION: These results indicate that FE-1 may be recommended as a new, noninvasive tubeless test of pancreatic function.

Adult↗

PubMed2005

Towards an alternative for the acute fish LC(50) test in chemical assessment: the fish embryo toxicity test goes multi-species -- an update.

After its standardisation at the national level in Germany (DIN 38415-6, 2001, 2001), the 48 h sewage testing assay with zebrafish (Danio rerio) embryos has been submitted for standardisation to ISO. As an alternative to the conventional acute (96 h) fish test, a modified fish embryo test will be submitted to the OECD for chemical testing in late 2005. For this, a protocol originally designed for zebrafish was adapted to fit also the requirements of other OECD species, namely medaka (Oryzias latipes) and fathead minnow (Pimephales promelas). Results document that the transfer of the protocol is possible with only minor modifications. Data obtained from embryo tests with the three species are comparable. Statistical analysis of existing zebrafish embryo toxicity data resulted in the conclusions (1) that there is a reliable correlation between the fish embryo test and the acute fish test, (2) that the confidence belt of the regression line was relatively small, but that the prediction range was relatively wide. The regression thus seems appropriate to describe the relationship between acute fish and embryo LC(50) with good confidence, but is less appropriate as a prediction model. Investigations into oxygen requirements of zebrafish embryos reveal that they adapt to a broad range of oxygen levels and survive at concentrations of 2 mg/l without malformations. Zebrafish embryos can thus be exposed in very small toxicant volumes (100 microl), which is of particular interest for the testing of metabolites. Dechorionation studies with 48 h old zebrafish embryos indicate that the barrier function of the chorion increases with the lipophilicity of the test compound. Finally, examples are given as to how additional endpoints can be incorporated into the fish embryo test protocol to extend its scope, e.g. to sediment toxicity assessment or genotoxicity and mutagenicity testing.

Animal Testing Alternatives↗

PubMed1992

Effect of skin test with M. leprae soluble antigen on reaction to a subsequent test with the same antigen.

Soluble skin-test antigens (STA), produced from armadillo-derived Mycobacterium leprae by Drs. Rees and Convit, were expected to meet the long-felt need of a test for leprosy infection and also to serve as tests for measuring postvaccination sensitization induced by vaccine preparations against leprosy. The present paper reports results from two studies examining the influence, if any, of skin testing with Rees' STA on reaction to a subsequent test with the same antigen. In the first study, 2168 persons from households of leprosy patients and from neighboring households were skin tested with Rees' STA twice at an interval of 6 months. In the second study, 1700 persons, free from leprosy, received either Rees' STA or normal saline by random allocation. A random subset of 850 persons was tested with Rees' STA after 3 months. The remaining 850 persons were tested with Rees' STA after 6 months. In addition, 242 leprosy patients were given Rees' STA or normal saline by random allocation, and all of these patients were tested with Rees' STA after 6 months. The results of the two studies showed that among persons reacting with a small size of reaction to Rees' STA, the size of the reaction to the repeat test was significantly larger. However, from the results of the second study, which included a control group, it was clearly seen that the quantum of boosting or sensitizing effect of the first test as well as that of new sensitization was small over a period of 3-6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1986

Admission test: a screening test for fetal distress in labor.

The usefulness of a short electronic fetal heart rate recording at admission of patients in labor (admission test) was investigated in low-risk patients in two prospective studies. The admission test was done in a concealed manner, and the result of the test was evaluated after delivery so as not to influence the clinical management. In part I of the investigation, the test was performed in 130 patients monitored during labor with pH determinations in scalp blood and in cord blood at birth. Patients with reactive admission tests had a low rate of intrauterine asphyxia in labor (0.9%), whereas half of the patients with ominous traces had intrauterine fetal asphyxia with a low scalp blood pH and neonatal depression. Similar results were obtained in part II, when the admission test was used as a screening procedure involving 1041 patients. The test was reactive in 94.3%, and in this group fetal distress (cesarean section, or forceps on that indication, or an Apgar score less than 7 at five minutes) occurred in 1.3%. Ten patients (1.0%) had ominous tests; four of these had fetal distress, and one of these fetuses died in utero three hours after admission, during which time stethoscopic auscultation failed to detect the fetal compromise. It is concluded that the admission test can detect fetal distress already present at admission and unnecessary delay in intervention can be avoided in such a case. The test seems also to have some predictive value for the fetal well-being for the next few hours of labor. The test is simple and convenient for screening purposes.

Delivery, Obstetric↗

PubMedDate not supplied

The photometric latex test for rheumatoid factors in patients with rheumatoid arthritis. I. correlation with other serologic tests.

The photometric latex test (PLT) for the detection of rheumatoid factors (RF) has been correlated with the sensitized sheep cell test (SSC) and the latex slide test (LST). A total of 377 sera from patients with rheumatoid arthritis (RA) and 120 sera from control subjects were examined. When the PLT was carried out on the native sera at a lower buffer ionic strength (0.05 M), agglutination was noted in over 99% of cases, indicating interaction of complement with human immunoglobulin bound to the latex particle surface. Although thermal inactivation eliminated most of the complement agglutination, an increase in ionic strength (0.5 M) was found to be essential for measuring only RF agglutination. The serologic data were analysed statistically by computer. A highly significant correlation was found between all serologic tests and RA sera, but there was no such correlation with the control sera. The specificity of all tests was generally over 90% and did not vary significantly, but the sensitivity varied from 52.0% to 71.1%, confirming that about one-third of all RA patients are seronegative. The tests were analysed for their total diagnostic capability. The PLT with native sera at higher ionic strenght proved to be the most sensitive, but with thermally inactivated sera it had a better diagnostic capacity. The SSC test appeared to be less sensitive and of lower diagnostic validity. Rapid LST tests were clearly inferior to PLT tests. The PLT can be used as a reliable and straightforward serologic method of diagnosis in RA, especially when carried out at a higher ionic strength and with thermally inactivated sera. It should be given preference over other serologic tests for RF and could well become standard practice in rheumatologic serology as a substitute for the SSC test.

Arthritis, Rheumatoid↗