The first International Standard anti-Brucella melitensis Serum

The World Organisation for Animal Health (OIE) requested an International Standard anti-Brucella melitensis Serum (ISaBmS) to standardise diagnostic tests and reagents for sheep and goats. The agreed criteria were the highest dilution (in negative serum) of the standard which must give a positive result and the lowest dilution (in negative serum) which must simultaneously give a negative result. The two dilutions for each assay were, respectively: indirect enzyme-linked immunosorbent assay (iELISA) 1/64 and 1/750, competitive ELISA (cELISA) 1/8 and 1/300, fluorescent polarisation assay (FPA) 1/16 and 1/200, Rose Bengal test (RBT) 1/16 and 1/200. The OIE International Standard Serum (OIEISS) will remain the primary standard for the RBT; the ISaBmS is an additional standard. It was impossible to set criteria for the complement fixation test, therefore the OIEISS will remain the primary standard. The ISaBmS can be used to standardise iELISA, cELISA and FPA to diagnose sheep and goat brucellosis. This standard should facilitate harmonisation of tests used for brucellosis surveillance and international trade in these species.

Prehospital treatment of opioid overdose in Copenhagen--is it safe to discharge on-scene?

INTRODUCTION

In the prehospital setting opioid overdose is often treated with naloxone. In our physician-based medical emergency care unit (MECU) we have adopted a discharge-on-scene policy, where patients are released on scene if no residual signs of opioid intoxication are found after treatment. The aim of this study was to describe our experience with the discharge-on-scene policy used during a 10-year-period with focus on the frequency of rebound opioid toxicity.

METHODS

Data were prospectively recorded in our MECU database and we reviewed all cases of opioid overdose between 1994 and 2003. The MECU database was cross-referenced with the Central Personal Registry. For patients who died within 48 h of MECU contact we reviewed the forensic autopsy reports to establish whether rebound opioid toxicity was likely.

RESULTS

We found 4762 cases of acute opioid overdose. In 3245 cases positive identification was obtained. Over this ten year period fourteen patients who were released on-scene after having been treated with naloxone died within 48 h, but only in 3 of these we found a rebound opioid toxicity to be the likely cause of death, corresponding to 0.13% of those 2241 released on scene who were identified.

CONCLUSION

Prehospital discharge-on-scene after naloxone treatment is associated with a low risk of death due to rebound toxicity.

Universal indirect enzyme-linked immunosorbent assay for monitoring of human and animal brucellosis in Kazakhstan

Combinations of conventional serological methods and new ELISA procedures were evaluated to develop the most efficient and effective diagnostics for the detection of brucellosis in humans and animals. Sera from humans (n=249) and animals (n=99) were collected from brucellosis endemic areas (Zhambyl district and Enbekshi-Kazakh district of Almaty region in Kazakhstan) for serologic analysis. Sera from the humans reacted positively in the RBT (38.5%), SAT (43.3%), iELISA (42.5%) while sera from the animals reacted positively in RBT (79.8%), SAT (89.9%), CF (87.8%), iELISA (100%). Greater seropositivity was detected in animals as compared to human samples. All positive sera were also evaluated on an indirect ELISA (iELISA). Bacterial isolation was attempted on seropositive human sera. Our data indicate that the combination of conventional serological tests (SAT and CF), combined with the iELISA is optimal for the processing of large numbers of samples and the most efficient detection of human and animal brucellosis.

Reference equations for specific airway resistance in children: the Asthma UK initiative

Plethysmographic specific airway resistance (sR(aw)) is a useful research method for discriminating lung disease in young children. Its use in clinical management has, however, been limited by lack of consensus regarding equipment, methodology and reference data. The aim of our study was to collate reference data from healthy children (3-10 yrs), document methodological differences, explore the impact of these differences and construct reference equations from the collated dataset. Centres were approached to contribute sR(aw) data as part of the Asthma UK initiative. A random selection of pressure-flow plots were assessed for quality and site visits elucidated data collection and analysis protocols. Five centres contributed 2,872 measurements. Marked variation in methodology and analysis excluded two centres. sR(aw) over-read sheets were developed for quality control. Reference equations and recommendations for recording and reporting both specific effective and total airway resistance (sR(eff) and sR(tot), respectively) were developed for White European children from 1,908 measurements made under similar conditions. Reference sR(aw) data collected from a single centre may be misleading, as methodological differences exist between centres. These preliminary reference equations can only be applied under similar measurement conditions. Given the potential clinical usefulness of sR(aw), particularly with respect to sR(eff), methodological guidelines need to be established and used in prospective data collection.

Serological diagnosis of brucellosis

AIM

To present a review and to describe the most widely used laboratory tests for serology diagnosis of brucellosis along with their pros and cons.

METHODS

Review the recent literature on brucellosis serology diagnostic tests. The choice of the testing strategy depends on the prevailing brucellosis epidemiological situation and the goal of testing.

RESULTS

The 'gold standard' for the diagnosis of brucellosis is isolation and identification of the causative bacterium, a member of Brucella sp. Isolation of Brucella sp. requires high security laboratory facilities (biological containment level 3), highly skilled personnel, an extended turnaround time for results and it is considered a hazardous procedure. Hence brucellosis is generally diagnosed by detection of an elevated level of antibody in serum or other body fluid. This is a presumptive diagnosis as other microorganisms and perhaps environmental factors can also cause increased antibody levels.

CONCLUSION

A large number of serological tests for brucellosis have been devised over the 100+ years since its initial isolation, starting with a simple agglutination test and progressing to sophisticated primary binding assays available today. However, no test devised to date is 100% accurate so generally serological diagnosis consists of testing sera by several tests, usually a screening test of high sensitivity, followed by a confirmatory test of high specificity.

Aberrations of HER2 and TOP2A Genes in Breast Cancer

Copy number changes in TOP2A are frequently observed in HER2 amplified breast cancers, and amplification of a whole amplicon containing both genes has been suggested as the underling mechanism. Here, we describe copy number changes of HER2 and TOP2A in two cell lines; one characterized by having amplification of both genes and the other by having amplification of HER2 and deletion of TOP2A. The characteristics are compared to findings in patients with invasive breast cancer.Material and methods: Fluorescence in situ hybridization (FISH) with HER2, TOP2A and centromere 17 (CEN-17) probes was performed on metaphases, interphases and cut sections from breast cancer cell lines. Paired HER2/CEN-17 and TOP2A/CEN-17 data was available from 649 patients from a previously published biomarker study (Knoop et al. J Clin Oncol 2005;23:7483-90).Results: The physical localization of FISH signals in metaphase spreads from cell lines showed that simultaneous amplification is not a simple co-amplification of a whole amplicon containing both genes. HER2 and TOP2A aberrations seem to be due to different mechanisms of amplifications. Most gene signals are translocated to abnormal marker chromosomes. HER2 genes but not TOP2A genes are present in tandem amplicons, leading to a higher HER2 ratio. This observation was confirmed by patient FISH data: 373 tumors (57%) had normal status for both genes. Among the 276 abnormal tumors, 67% had different HER2 and TOP2A status. Simultaneous amplification of both genes was found in 28% of the abnormal tumors (12% of all patients) while deletion of both genes was observed in 5% of the cases (2% of all patients). The average gene/reference ratio was significantly different: 5.0 for TOP2A but 7.2 for HER2 in the amplified tumors (P<0.001; χ2-test). In the HER2 assay 398 (61%) of the 649 tumors had more than 4 gene signals per nucleus while only 96 (15%) of the tumors had more than 4 TOP2A signals per nucleus.Conclusion: In the majority of breast cancer patients, simultaneous aberration of HER2 and TOP2A is not explained by simple co-amplification. Amplification of the two genes may be caused by different mechanisms, leading to higher level of amplification for HER2 compared to TOP2A.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2119.

Polysomy of Chromosome 17 in Breast Cancer

Purpose: Polysomy of chromosome 17 is frequently described in breast cancer, but firm definition of polysomy is lacking. We have used normal breast tissue to define the ploidy levels in the truncated nuclei of cut sections based on standard cytogenetic definition of ploidy in whole nuclei. Data from patients with invasive breast cancer enrolled in a randomized clinical trial was used to investigate the effect of polysomy of centromere 17 on patient survival. (Ejlertsen B et al., Eur J Cancer 2007:43:877-84).Material and methods: Fluorescence in situ hybridization (FISH) with TOP2A/CEN-17 was performed on 120 normal breast specimens. Centromere 17 (CEN-17) measurements from matching HER2/CEN-17 and TOP2A/CEN-17 FISH data was available from 649 patients from a previously published biomarker study (Knoop A et. al., J Clin Oncol 2005;23:7483-90).Results: Two thirds of the tumors had an average number of CEN-17 signals below two and 10% had more than three average CEN-17 signals. Monosomy (<1.25 CEN-17/nucleus) of centromere 17 was observed in 8% of the tumors, 60% of the samples were diploid (1.26-2.09 CEN-17/nucleus), 22% triploid (2.10-2.93 CEN-17/nucleus), 5% tetraploid (2.94-3.77 CEN-17/nucleus) and 5% of the tumors had higher ploidy level (>3.78 CEN-17/nucleus). In the aneuploid tumors and especially in the highly polyploidy tumors, amplification is the most frequent event in the HER2 assay whereas deletions increased with the ploidy level in TOP2A assay. Increasing ploidy was associated with decreased overall survival (P=0.0001), but multivariate analysis showed that polyploidy was not an independent prognostic factor neither predictive for treatment outcome.Conclusion: Polysomy 17 is a rare event in tumor samples from patients, but correlate to HER2 amplification and TOP2A deletion. However, inclusion of a reference probe is necessary if deletions are to be revealed and to avoid false positive amplified cases with a high proportion of dividing cells or a doubling of the DNA content. Very high polyploidy is associated with poor survival but is not an independent prognostic factor when other prognostic factor are included in a multivariate analysis. In this large clinical study, polysomy 17 was neither an independent prognostic nor predictive marker.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4035.

Validation and field assessment of a rapid lateral flow assay for detection of bovine antibody to Anaplasma marginale

The lateral flow assay (LFA) is a rapid diagnostic test which may be performed under most conditions and is especially useful for field applications. This type of assay was applied to the detection of antibody to bovine Anaplasma marginale using sera from endemic areas and from areas which have been free from infection for more than 25 years. Briefly, the test uses recombinant A. marginale major surface protein 5 peptide (Msp5), immobilized on a cellulose acetate membrane. A serum sample is added to a pad containing a monoclonal antibody specific for bovine IgG(1), conjugated with colloidal gold, located at one end of the strip. The sample and gold conjugate are wicked along the membrane and if antibody is present in the serum, a visible line will form between the Msp5-antibody-conjugate immune complex in minutes. An additional band of recombinant protein A/G was added to the membrane as a positive control reaction of the monoclonal antibody conjugate. For comparison, direct examination of blood smears and a nested polymerase chain reaction (PCR) were performed on some of the samples. Using samples from herds in one endemic area, the PCR gave a sensitivity value of 9.2% while a commercial competitive enzyme immunoassay (CELISA) gave a sensitivity value of 17.2% and the LFA values of 20.5%. In a second endemic area, selected samples, all positive by direct examination gave a 71.7% sensitivity values with the PCR, 94.5% with the CELISA and 95.5% with the LFA. Using sera from a disease-free area, the specificity values were 100% for the PCR (testing a proportion of randomly selected samples), 99.5% for the CELISA and 98.0% for the LFA. It is envisaged that the validated LFA will be a useful tool for screening cattle moving from an area with infection to a disease-free area.

A proficiency testing method for detecting antibodies against Brucella abortus in quantitative and qualitative serological tests

A proficiency testing panel for detecting antibodies against Brucella abortus was developed and evaluated by both primary binding and conventional serological tests, using the guidelines of the World Organisation for Animal Health and the International Organization for Standardization Guide 43-1. All serological tests were judged satisfactory. Among the primary binding tests, the competitive enzyme-linked immunosorbent assay (ELISA 2) and the indirect enzyme-linked immunosorbent assay (ELISA 1), with standard deviation indices (z-scores) of -0.06 and 0.10, respectively, performed best. Similarly, E(n) numbers (i.e. a way of comparing different measurements of performance) of 0 for both the competitive ELISA 2 and the indirect ELISA 1 indicated that these tests performed best in the initial round of proficiency testing. The conventional serological tests all passed the panel. Comparing data from both the quantitative and qualitative tests demonstrated that this proficiency testing scheme was fit for the purpose for which it was designed.

Evaluation of three different antigens in an indirect enzyme-linked immunoassay for the detection of antibodies against Brucella abortus SRB51 in vaccinated heifers

The live attenuated Brucella abortus SRB51 (SRB51) is a partial O-chain-deprived mutant. The relative lack of the polysaccharide prevents it from inducing antibodies detectable by most of the serological tests used for the diagnosis of bovine brucellosis. The performance of three antigens used in an indirect enzyme-linked immunoassay test for detecting SRB51 antibodies were evaluated. A homogeneous group of twenty-five 10-month-old Hereford heifers was used. The animals were bled on day 0 and then subcutaneously vaccinated with 2 ml of a commercially available SRB51 vaccine (Schering-Plough) containing 1x10(7) to 3.4x10(7) viable cells. Blood samples without anticoagulant for sera obtaining were then collected at days 30, 90, 210 and 360 post-vaccination. To detect the SRB51 antibodies, Brucella ovis hot saline extract, B. ovis RLPS (RLPS), and SRB51-RLPS were used. The buffered antigen plate agglutination test and an indirect enzyme-linked immunoassay (I-ELISA) using the smooth LPS (SLPS) antigen from B. abortus were used as control tests. All the sera samples were negative in the BPA test and in the standard I-ELISA using the SLPS. The SRB51-RLPS and the B. ovis RLPS antigens performed better than the B. ovis hot saline extract antigen.

Comparison of five DNA quantification methods

Six commercial preparations of human genomic DNA were quantified using five quantification methods: UV spectrometry, SYBR-Green dye staining, slot blot hybridization with the probe D17Z1, Quantifiler Human DNA Quantification kit and RB1 rt-PCR. All methods measured higher DNA concentrations than expected based on the information by the manufacturers. UV spectrometry, SYBR-Green dye staining, slot blot and RB1 rt-PCR gave 39, 27, 11 and 12%, respectively, higher concentrations than expected based on the manufacturers' information. The DNA preparations were quantified using the Quantifiler Human DNA Quantification kit in two experiments. The measured DNA concentrations with Quantifiler were 125 and 160% higher than expected based on the manufacturers' information. When the Quantifiler human DNA standard (Raji cell line) was replaced by the commercial human DNA preparation G147A (Promega) to generate the DNA standard curve in the Quantifiler Human DNA Quantification kit, the DNA quantification results of the human DNA preparations were 31% higher than expected based on the manufacturers' information. The results indicate a calibration problem with the Quantifiler human DNA standard for its use with the Quantifiler Human DNA Quantification kit. The possible reasons for the problem are discussed and a solution is suggested. The results emphasise the need for standard reference DNA material and standard methods for DNA quantification.

Development of a lateral flow assay for rapid detection of bovine antibody to Anaplasma marginale

A rapid lateral flow assay for detection of bovine antibody to Anaplasma marginale was developed. The assay used a recombinant peptide of major surface protein 5 as the antigen and a monoclonal antibody specific for bovine IgG(1) conjugated with colloidal gold beads for detection. Serum and anticoagulated blood samples were obtained from cattle in an area where anaplasmosis was endemic. The samples were selected based on positive identification of the organism in blood smears. The unclotted blood samples were used for PCR determination of the presence of A. marginale while the sera were tested by a commercial competitive enzyme immunoassay (CELISA) and by the lateral flow assay (LFA). Similar samples, collected at a Canadian sales barn, were tested by the CELISA and LFA and 10% were tested by PCR for the presence of A. marginale nucleic acid. In addition, stored serum samples from a second endemic area were tested by CELISA and LFA. Of the 114 smear positive samples, all were positive by CELISA and LFA. All samples were also positive by PCR. Samples from Canadian sources (n=524) were negative in the CELISA but 11 sera gave false positive reactions in the LFA. All samples tested were PCR negative. Of 113 samples from herds with anaplasmosis, 53 were positive in the CELISA and 50 were LFA positive.

Stereologic estimation of the total numbers, the composition and the anatomic distribution of lymphocytes in cone biopsies from patients with stage I squamous cell carcinoma of the cervix uteri

The aim of this study was to present a method to obtain basic biological data on the in situ cellular immune response towards cancer. Using stereology, we estimated the density and frequency of immune cells of 10 different phenotypes in cone biopsies from 20 patients with FIGO stage I cervical squamous cell carcinoma. The anatomic distribution of immune cells with respect to intraepithelial, periepithelial or stromal compartments was recorded in normal epithelium, dysplastic epithelium and carcinoma. We estimated the number of immune cells per cancer cell, and the 3D total number of immune cells, inside cancer tissue. The tumor volume was estimated in 3D and corrected for shrinkage occurring during tissue processing. We found more immune cells in cancer compared to dysplasia and normal epithelia. A median total number of 278 . 10(3) CD3+, 69.1 . 10(3) CD4+ and 113 . 10(3) CD8+ cells were present in the cancers. A median number of 63 CD3+, 11 CD4+ and 29 CD8+ cells were present per cancer cell. The average volume of tumors in stage IA was significantly smaller than that of stage IB. This method was found to be usable and of potential value in clinical pathology research, and for development and evaluation of immunotherapy.

Validation of a second generation competitive enzyme immunoassay (CELISA) for the diagnosis of brucellosis in various species of domestic animals

A second generation competitive enzyme immunoassay (CELISA) for detection of bovine antibody to Brucella abortus was developed to eliminate reagent variables in the assay. This assay was different from earlier CELISA formats in that it used recombinant protein A and protein G immunoglobulin receptors (PAG), labelled with horseradish peroxidase, thus eliminating the requirement for polyclonal anti-mouse-enzyme conjugate for detection. This allowed standardization of the assay. The CELISA uses a monoclonal antibody specific for a common epitope of the O-polysaccharide (OPS) of smooth lipopolysaccharide (SLPS) derived from B. abortus S1119.3. This antibody did not react with PAG. This monoclonal antibody was used to compete with antibody in the bovine test serum to the smooth lipopolysaccharide (SLPS) antigen. Reaction of bovine antibody was then measured directly with the PAG enzyme conjugate. In this case, development of colour in the reaction indicated a positive reaction. The performance characteristics of the new CELISA, sensitivity, specificity and exclusion of antibody of B. abortus S19 vaccinated animals, were very similar to those of the classical CELISA and to the indirect enzyme immunoassay (IELISA) when using sera deemed positive by isolation of the bacterium, either from individual animals or from some animals on the premises. All sera were tested by the buffered antigen plate agglutination test (BPAT) and the complement fixation test (CFT). Only samples positive on both BPAT and CFT were considered as positive and only samples negative on both tests were used considered negative. Sufficient samples from cattle, swine, sheep and goats to validate the test were included based on OIE guidelines suggesting inclusion of a minimum of 300 positive and 1000 negative samples.

Virtual reality training for radiotherapy becomes a reality

A report in 2007 to the UK Government identified a crisis in England for training staff and students for the radiotherapy treatment of cancer. The Hull authors have developed an immersive life size virtual environment of a radiotherapy treatment room, known as VERT, to address this problem. VERT provides the trainee with models, simulation, enhanced visualization and training aids for treatment of virtual patients in a virtual treatment room. In 2007 immersive VERT systems for radiotherapy training were established for training purposes at the University Aarhus Hospital (Denmark) and the Birmingham City University (UK). This paper reports on early evaluations of VERT by these two institutions.

Prototype single step lateral flow technology for detection of avian influenza virus and chicken antibody to avian influenza virus

A rapid and effective lateral flow assay (LFA) for detection of avian influenza virus (AIV) was developed. For antigen capture, the assay used monoclonal antibody specific for a conserved nuclear protein (NP) epitope, immobilized on a cellulose acetate matrix, in conjunction with a second NP monoclonal antibody chemically linked to either coloured latex beads or colloidal gold particles contained in a sample pad for detection. Virus sample added to the sample pad flowed into the trapping antibody to form a visible band as well as a second, control band further along the acetate strip. The control band consisted of recombinant protein A/G, also immobilized on the matrix. A second LFA for detection of chicken antibody to AIV was developed where NP antigen was immobilized on the matrix with recombinant protein A/G immobilized as a control band. Latex beads or colloidal gold particles to which monoclonal anti-chicken antibody was attached, were used as the indicator system.