Rapid antimicrobial susceptibility testing of isolates from blood cultures by direct inoculation and early reading of disk diffusion tests

Disk diffusion tests, inoculated directly from positive blood cultures, were evaluated for accuracy of reading zone diameters after 4- and 6-h and overnight incubation. In comparisons with results from standard disk diffusion tests, the 4-h results were in agreement for 83% of tests with gram-positive organisms and 64% of tests with gram-negative organisms. When minor discrepancies were ignored, the 4-h readings were in agreement for 98% of the tests with gram-positive organisms and 95% of the tests with gram-negative organisms. After 6 h of incubation, 91% of the tests with gram-positive organisms and 86% of the tests with gram-negative organisms agreed with standard results. The agreement was 99% for tests with both gram-positive and gram-negative organisms when minor discrepancies were excluded. Very major discrepancies occurred in two tests (0.1%) with gram-positive organisms and were not observed in tests with gram-negative organisms. The frequencies of major discrepancies were 3.5% after 4 h, 0.6% after 6 h, and 0.7% after overnight incubation. Ampicillin and cephalothin tests with Escherichia coli and Klebsiella spp. accounted for 81% of the major discrepancies in tests with gram-negative organisms. Oxacillin tests accounted for more than half of the major discrepancies in tests with staphylococci. The results of this study, which did not include the newer antibiotics, indicate that direct susceptibility tests from blood cultures read after 6 h of incubation are more reliable than 4-h results and produce less than 1% major errors in comparisons with standard susceptibility tests.     

Competitive enzyme-linked immunosorbent assay for Treponema pallidum antibodies

A competitive enzyme-linked Treponema pallidum immunosorbent assay (CETPIA) was compared with the standard serological tests for syphilis. Of 3081 serum samples submitted, 2883 gave negative results in the CETPIA and the routine screening tests. Positive results were obtained in the CETPIA and in one or more of the specific treponemal tests with 115 samples. Discrepancies in the results of the CETPIA and standard serological tests were found with 83 serum samples, most of these were attributed to biological false positive reactions in the Venereal Disease Research Laboratory (VDRL) test. CETPIA may have a role in the serological diagnosis of syphilis.     

Utilization and access to antiretroviral genotypic resistance testing and results within the US Department of Veterans Affairs

OBJECTIVE: We sought to characterize variation in the use of HIV genotypic resistance tests and how results were reported. METHODS: Clinicians and laboratory managers at all Veterans Affairs (VA) medical centers were asked to complete a survey in March 2003 regarding HIV resistance testing practices. RESULTS: Surveys from 131 of 150 sites were returned. Forty-eight percent of HIV clinicians indicated that US Department of Health and Human Services guidelines were the usual basis for ordering tests. Although between 12% and 31% of respondents indicated that they always, sometimes, seldom, or never ordered resistance tests in patients with acute or chronic HIV infection, >70% ordered tests in adherent patients with treatment failure. Among the 32 centers with >200 patients in care, 13 +/- 8 (mean +/- standard deviation) tests were performed per 100 patients in care during 2002. Forty-nine percent of clinicians said that tests were helpful, but only 33% expressed confidence in using test results. Only 40% of sites entered results in the VA electronic medical record. CONCLUSION: Ordering patterns for HIV resistance tests differed significantly among VA sites. A minority of clinicians indicated confidence in the use of test results. A consistent system to capture and present complete results was absent.     

Evaluation of candida precipitin and agglutinin tests for the diagnosis of systemic candidiasis in burn patients.

Candida agglutinin and precipitin tests were performed on a group of burned patients without evidence of systemic candidiasis to determine whether tests could be used to distinguish between colonization and systemic disease, as has recently been reported. There were considerable numbers of false-positive results using both tests. These false-positive results occurred regardless of the candida colonization status of the patient. We conclude that these tests are of little diagnostic value in burn patients.     

The haemagglutination inhibition and the Hogben test in pregnancy

Haemagglutination inhibition tests are easy to perform and easy to read. The results are reproducible and are not subject to the vagaries of supply and temperament inherent in tests using living creatures. In a series of tests with Prepuerin done in parallel with the Hogben test the former has shown a higher sensitivity. There have been three false positive results with Prepuerin tests in the series but it was not established on general grounds that pregnancy was not in fact present.     

The ecological validity of traditional memory evaluation in relation with controlled memory processes and routinization

The neuropsychological evaluation of memory by traditional tests raises questions about their ecological validity, as the results on these tests often have little relation to the memory complaints. In an attempt to explain this lack of relationship, the present study had two objectives: (1) explore the ecological superiority of the Process Dissociation Procedure (PDP) over traditional memory tests and (2) explore the effects of routinization on the relationship between memory complaints and memory tests. Thirty-three participants aged 55-86 years were given the PDP (memory evaluation), two questionnaires evaluating daily memory complaints (QAM and CDS) and a questionnaire evaluating routinization (EPR). The results indicate that the PDP, with its measure of controlled processes, is more ecological than traditional memory tests for elderly people. As well, the participants' lifestyle (routinized versus non-routinized) influenced their results on memory tests. The results are discussed in relation to neuropsychological evaluation and rehabilitation.     

Role of intradermal skin tests in the evaluation of clinically relevant respiratory allergy assessed using patient history and nasal challenges.

BACKGROUND: Skin testing, correlated with patient history, is the accepted method of identifying clinically relevant aeroallergen sensitivity. Traditionally, intradermal tests are believed to be more sensitive in identifying aeroallergen sensitivity than the epicutaneous and percutaneous methods. Therefore, many allergy practitioners use the epicutaneous or percutaneous method first and, if the results are negative, follow up with intradermal tests. OBJECTIVES: To compare the epicutaneous, percutaneous, and intradermal methods to determine their sensitivity to patient history and to evaluate the value of intradermal tests when epicutaneous and percutaneous test results are negative. METHODS: Participants were evaluated for rhinoconjunctivitis symptoms and then were skin tested using the prick and Multi-Test II (MTII) methods. Intradermal tests were performed when prick and MTII test results were negative to an aeroallergen. Participants with negative prick and MTII test results and corresponding positive intradermal test results underwent nasal challenges with evaluation by anterior rhinomanometry. RESULTS: Compared with patient history, average sensitivity for MTII was 77% and for the prick method was 62%. When MTII results were negative, 17% of intradermal tests corresponded with probable patient histories of allergy but none with positive nasal challenge results. Nasal challenge results were similar to those of the negative control group and significantly different from those of the positive control group (P < .001). CONCLUSIONS: The MTII tests are more sensitive and equally specific compared with the prick method. When MTII results are negative, positive intradermal test results are unlikely to identify clinically relevant aeroallergen sensitivity. Routine performance of intradermal tests when MTII results are negative is likely to be of low clinical yield.     

Bench Tests of an Implantable Axial Blood Pump

Methods and results of tests of biomedical parameters of a new accessory circulation apparatus based on implantable axial blood pump are discussed in this work. Bench tests were directed toward determining energy parameters and pump-induced injury of blood cells. The results of the tests allowed efficiency of the developed system to be evaluated within a wide range of working load.     

Usefulness of "essential laboratory tests" for the establishment of the initial diagnosis in new outpatients]

"Essential laboratory tests" advocated by Japan Society of Clinical Pathology were simultaneously performed with the history taking of the present illness and the physical examination in 1,026 new patients visited the outpatient unit of Comprehensive Medicine, National Defense Medical College. We have analyzed the usefulness of the "essential laboratory tests" for the establishment of the initial diagnosis in evaluable 750 patients by comparing the diagnosis made only by the history taking and the physical examination (tentative initial diagnosis) with that included the results of these laboratory tests. The "essential laboratory tests" had contributed to remarkably increased incidences of metabolic and endocrine diseases, liver or biliary tract diseases, renal and urinary tract diseases and anemia after the application of these tests. The initial diagnoses of 61 patients were successfully established by the addition of the "essential laboratory tests" among 157 cases of which tentative initial diagnoses remained undetermined. These tests confirmed the tentative diagnoses in 78 patients, while 78 tentative diagnoses were negated and corrected after evaluation of the results of these tests. Furthermore, the diagnostic tests such as CRP and leukocyte count were useful for the estimation of the nature or degree of seriousness of the disease in 57 patients. In addition, other diseases not related to the patient's chief complaint could be detected in 238 patients (303 total number of diseases) by these tests. These results indicate the usefulness of the "essential laboratory tests" not only for the establishment of more accurate initial diagnosis but also for the screening of the "hidden" diseases such as hyperlipidemia and liver dysfunction.     

Comparison of measurements of serum venom-specific IgG by radioimmunoassay and enzyme immunoassay

Honeybee venom (BV)-, yellow jacket venom (YJV)- and honeybee venom phospholipase A (PLA)-specific IgG were measured by radioimmunoassay (RIA) and enzyme immunoassay (RIA) in 54 sera of insect-allergic patients. In the majority of sera, results of the two tests were similar. Discordant results were found in 1 of 21 sera in tests with PLA, 4 of 23 sera in tests with BV, and 1 of 16 sera in tests with YJV. The RIA measured higher antibody titers in 5 of these 'outlier' sera. The results suggest that with a few exceptions, the two assays are similar for detection of venom- and PLA-specific IgG.     

Dealing with initial inconclusive serological results for chronic Chagas disease in clinical practice

Most guidelines for Chagas disease recommend the performance of two serological tests in order to detect it. However, inconclusive results may arise from this strategy. The aim was to describe whether serological follow-up together with the patient’s clinical characteristics could clarify the outcome of patients with initial inconclusive test results. In this retrospective case series, all results of Chagas disease serological tests and outpatient visits recorded from 2004 to 2008 were screened for inclusion. The inclusion criterion was clinical suspicion of chronic Chagas disease and the exclusion criteria were previous diagnosis of Chagas disease, suspicion of acute Chagas disease, and serological tests with no corresponding medical evaluation. A total of 1,732 patients were analyzed. Chronic Chagas disease prevalence was 21.1%. After the initial set of serological tests, 2.9% of patients had inconclusive test results. Most of these patients had definite diagnosis after clinical follow-up and the repetition of serological tests in a new blood sample. Loss to follow-up while partaking in the diagnostic investigation reached 17.7%. The prevalence of initial inconclusive serological tests for chronic Chagas disease is low. Clinical evaluations and follow-up clarify the definite diagnosis. Noncompliance to follow-up is a frequent problem. Strategies to reduce inconclusive results and noncompliance are discussed.     

Public awareness and use of direct-to-consumer personal genomic tests from four state population-based surveys,and implications for clinical and public health practice

PurposeDirect-to-consumer personal genomic tests are widely available, but population-based data are limited on awareness and use of these tests among the general public in the United States.MethodsWe assessed awareness and use of direct-to-consumer personal genomic tests in Connecticut, Michigan, Oregon, and Utah using the 2009 Behavioral Risk Factor Surveillance System and compared the state results to the 2008 national HealthStyles survey results.ResultsAwareness was the highest in Oregon (29.1%) and the lowest in Michigan (15.8%). Factors associated with awareness across all states and nationally were higher education, higher income, and increasing age, except among those 75 years or older. Less than 1% of respondents had used the tests, with about one-half to three-quarters of those sharing the results with a health-care provider.ConclusionsAwareness of direct-to-consumer genetic tests is greater in this study as compared with a related study conducted in 2006, whereas use is similarly low in both studies. The few respondents who reported using the tests often reported sharing their results with their health-care provider, indicating an important opportunity for health-care providers to offer patient education regarding these tests. Public health agencies have important roles in surveillance, education, and policy development on direct-to-consumer genomic tests.Genet Med 2012:14(10):860–867     

In vitro and in vivo biological responses to some dental alloys tested separately and in combinations

Biocompatibility of dental alloys has been tested both in vivo and in vitro. In addition, combinations of dissimilar alloys were investigated in relation to possible enhanced corrosion by galvanic effects. Implantation tests, cytotoxicity tests on epithelial cells, macrophages and erythrocytes were performed, and the results compared. The severity of tissue response in implantation tests corresponded to the nobleness of the casting alloys joined to amalgam. Similar results were obtained in the in vitro macrophage test. All the alloys except the high-gold alloy (LM-Hard) had a toxic effect on epithelial cells. The combination of the casting alloys with amalgam diminished the toxic effect. Three of the alloys (amalgam, LM-Hard and Midi low-gold alloy) caused a slight haemolysis. Poor correlation was obtained between the agarose overlay tests, the haemolysis tests and the implantation tests.     

Detection of Aspergillus fumigatus precipitins: a comparison of counter immunoelectrophoresis and double diffusion.

A counter immunoelectrophoresis method was compared with a double diffusion test for detecting Aspergillus fumigatus antibodies. Of 70 patients, 23 gave positive results in both tests and the remainder gave negative results. Fifteen patients with proven aspergillosis gave positive results in both tests.     

Comparison of diagnostic tests for hymenoptera sting allergy

The authors examined correlations among individual Hymenoptera venom skin tests, venom radioallergosorbent tests (RAST), venom-induced leukocyte histamine release (LHR) assays and individual Hymenoptera whole body extract (WBE) skin tests in 37 patients with histories of systemic reactions to Hymenoptera stings. Significant positive correlations were seen between the venom skin test results and results from either the venom RAST or the LHR assay for most venoms. There was a relatively high frequency of positive WBE skin tests in association with other negative tests. The ultimate diagnostic test for stinging insect sensitivity is a deliberate sting challenge; in lieu of such a sting the clinical history and the venom skin test appear to provide the best estimate of clinical Hymenoptera sting sensitivity.     

Comparison of neuropsychological data in the diagnosis of brain impairment with computerized tomography and other neurological procedures.

Discussed the problem of criterion validation of neuropsychological tests. Computerized tomography (CT) is suggested as an approach in providing a criterion of focal structural lesions for evaluating predictability of neuropsychological tests. Neuropsychological tests on 62 patients were compared with CT scans, electroencephalographic results, and routine neurological examination. Results of the neuropsychology evaluation produced overall better agreement with CT scan results than did the other procedures. Diagnostic limitations of CT scanning and the unique diagnostic contribution of neuropsychological test results are discussed.     

Field performance of the INSTI HIV-1/-2 antibody test in two South African antenatal clinics

This was a prospective study that assessed field performance of the INSTI HIV-1/-2 antibody test (INSTI test) in two antenatal clinics in South Africa (SA). INSTI test was evaluated against rapid tests used at these clinics, and pooled nucleic acid amplification testing (NAAT) performed for individuals with negative rapid tests. Three hundred and eighty-six pregnant women were enrolled; 334 (86.5%) with negative results on the screening rapid test, and 52 (13.5%; 95% confidence interval [CI]: 10.2–17.3%) with positive results on screening and confirmatory rapid tests. INSTI test yielded the same results as other rapid tests in all participants, thus showing a 100% sensitivity (95% CI: 93.2–100.0%) and specificity (95% CI: 98.9–100.0%). Pooled NAAT was performed for 290 participants who had negative rapid tests, and yielded negative results in all pools. These data show excellent field performance of the INSTI test, and highlight that this test can be implementedat SA clinics.     

Antigenic characteristics of Marek's disease tumour cells

Surface antigens of Marek's disease lymphoblastoid cells were studied by indirect immunofluorescence (FA) tests and by cytotoxic antibody tests. The results of FA tests revealed genetic differences between cell lines of different sources with respect to their histocompatibility antigens. JMV and MSB-1 cells shared one of their alloantigens detectable by B blood group antisera. Differences between the cell lines were more pronounced when the respective hyperimmune sera were examined by cytotoxicity tests rather than by FA tests. The results of cross-absorptions of cell line antisera with cells of the different lines suggested that no identical common tumour-specific cell surface antigen was detectable serologically in addition to histocompatibility antigens or other normal cell surface antigens. The results of vaccination experiments with chicken embryo fibroblasts and with cells from various lymphoid tissues indicated that resistance against JMV lymphoblastic leukaemia could be induced by a number of different antigens which were not specific to Marek's disease.     

Relationships between skin prick test, radioallergosorbent test, and chemiluminescent assays in allergic children

The results of skin prick tests (SPT), radioallergosorbent tests (RAST), and multiple chemiluminescent tests (DHS-CLA) to grass mix, parietaria, D. farinae, and D. pteronyssinus were evaluated in 43 allergic children. All CLA tests had valid positive and negative control threads. Chemiluminescent assays class 4 matched with RAST class 3 and/or 4 and CLA class 3 with RAST class 2. The D. farinae, D. pteronyssinus, and grass results obtained with CLA, RAST, and SPT were investigated by principal components analysis that showed a good association between different methods of measuring allergenicity. The results of the present study confirm that DHS-CLA is an effective "in vitro" method for the detection of IgE-allergen specific antibody.     

Measles antibodies detected by platelet aggregation and gel precipitation in patients with subacute sclerosing panencephalitis

Summary Two serological techniques previously developed in our laboratories, platelet aggregation (PA) and gel precipitation (GP), are introduced as methods for detecting measles antibodies in patients with subacute sclerosing panencephalitis (SSPE). In PA tests of 11 SSPE patients high serum titers and moderate cerebrospinal fluid (CSF) titers were found. In GP tests all the sera formed 3 to 6 lines and CSF 1 to 2 lines against measles antigens. In 6 out of 50 post-measles sera positive PA reactions were found and only weak GP reactions with 1 to 3 lines were seen in tests on 37 sera studied.In post-measles sera the greatest number of positive reactions in both tests were obtained when more than one month had elapsed from the onset of the disease. The results of PA and GP tests correlated well with the results of complement fixation tests in sera and CSF of patients with SSPE, but no clear correlation was observed in post-measles sera.