Immunomagnetic Method Research Articles

Rapid and Quantitative Detection of Hepatitis A Virus from Green Onion and Strawberry Rinses by Use of Real-Time Reverse Transcription-PCR

In this study, an immunomagnetic capture method and a real-time reverse transcription-PCR assay were used to quantify hepatitis A virus (HAV) in green onion and strawberry rinses. This combined protocol detected as low as 0.5 PFU HAV in produce rinses and concentrated HAV levels up to 20-fold.

A comparative study of immunomagnetic methods used for separation of human natural killer cells from peripheral blood

Immunomagnetic sorting of natural killer (NK) cells from the peripheral blood of healthy donors has been evaluated in a comparative study of composition, yield and activation of target cells obtained by positive (Dynabeads, Microbeads) and negative (Microbeads) sorting procedures. Positively sorted target cells were selected by expression of the NK cell marker CD56, whereas NK cells obtained by negative sorting were those remaining after steps to remove all non-NK cell leukocyte populations were accomplished. In positive sorting, both CD56 +CD3 − NK cells and CD56 +CD3 + natural killer T (NKT) cells were included. The NKT cell fraction differed between individuals, but not between the positive sorting methods. Whereas 20–30% of positively sorted target cells were NKT cells, only ∼ 3% of negatively sorted cells were CD3 +. Contamination with monocytes and B cells was low (1–3%) in all methods studied. Sorting with Microbeads (both positive and negative) gave higher cell yields than those obtained with Dynabeads (14% vs. 5% of total leukocyte numbers). A higher CD56 fluorescence intensity of NK cells and a better discrimination between the CD56 bright and CD56 dim NK cell subpopulations was obtained after negative sorting. Dynabeads-separated cells had, shortly after separation, a significantly higher expression (∼ 30%) of the early activation marker CD69 than cells either positively or negatively separated by Microbeads (∼ 8%). CD56 + cells positively sorted by Microbeads demonstrated a significantly higher production of TNF-α and IFN-γ after IL-2 stimulation than Dynabeads-sorted cells. However, the cytotoxicity of cells obtained by the two positive sorting procedures did not differ. In conclusion, positive selection of CD56 + cells by Microbeads is better than Dynabeads, as determined from cell yield and procedure-associated cell activation and should be chosen for in vitro studies of NK/NKT cells. However, when pure NK cells and phenotypic subtypes are to be studied, negative sorting seems most appropriate.

Hematogenous Micrometastases in Osteosarcoma Patients

Bone marrow and peripheral blood samples from 60 patients with suspected bone sarcoma were examined for the presence and number of micrometastatic osteosarcoma cells by a sensitive immunomagnetic detection assay, using in parallel two osteosarcoma-associated antibodies. Forty-nine of the patients had osteosarcoma, and of these, as many as 31 (63%) had tumor cells in bone marrow, in many cases with a high number of cells. Only four (8%) were positive also in blood. None of 38 control bone marrow samples were positive, including 11 from patients with suspected bone sarcoma at time of sampling who later were found not to have osteosarcoma. Fifteen of 28 patients without overt metastases at primary diagnosis (54%) were positive, 12 of whom had localized high-grade primary tumors in the extremity. Four of these have relapsed compared with none of 10 negative patients. In the group of 22 patients with extremity localized nonmetastatic osteosarcoma, information was available on the histologic response to preoperative chemotherapy in 15 patients. None of the three patients in the bone marrow-negative group who had a poor response to chemotherapy have relapsed, whereas two of the four poor responders in the bone marrow-positive cohort are dead of disease. Among 12 patients with overt metastasis at primary diagnosis, 11 (92%) were positive in bone marrow with a very high number of osteosarcoma cells. The immunomagnetically isolated cells were further characterized by the use of fluorescent latex microparticles with surface-bound antibodies targeting different membrane markers. Moreover, in cases with numerous osteosarcoma cells in bone marrow attempts to grow the selected cells in vitro were successful in two of eight attempts, and in two of five cases, isolated cells produced tumors with osteosarcoma characteristics in nude mice. In conclusion, already at primary diagnosis, a very high fraction of osteosarcoma patients had malignant cells in bone marrow, and a correlation between the presence of tumor cells, clinical stage, and disease progression was found. The data show the clinical potential of this immunomagnetic method. Attempts to subgroup osteosarcoma patients for more individualized treatment based on the presence of micrometastatic cells should be studied in a larger cohort of patients.

Cell tracking velocimetry as a tool for defining saturation binding of magnetically conjugated antibodies

Continuous flow immunomagnetic separation is an attractive alternative to current batch mode immunomagnetic separation methods because it is capable of high sorting speeds at mild cell conditions, and grants the operator better control of separation process. The control of the separation is dependent on knowledge of the amount of magnetic label attached to the cell (magnetic labeling intensity), however. Determination of the magnetic labeling is accomplished by measuring cell magnetophoretic mobility using a newly developed technique of Cell Tracking Velocimetry (CTV). Flow cytometry was used to define the antibody binding characteristics of a fluorescently tagged primary antibody. Subsequently, CTV was used to measure antibody-binding characteristics of a magnetically tagged secondary antibody. The results of this study show that CTV is capable of providing valuable information concerning the cell labeling by magnetically tagged antibodies. It was demonstrated that the magnetically conjugated antibody binding curve exhibits the same exponential increase to saturation characteristics as that seen with the fluorescently tagged antibody. Further, it was shown that the intensity of the secondary magnetic labeling is directly proportional to the intensity of the primary fluorescent label. CTV is an accurate tool for evaluation of magnetically conjugated antibodies. The ability to determine the intensity of magnetic labeling is necessary for the development of continuous flow immunomagnetic separations based on cell magnetophoresis.

The use of a panel of monoclonal antibodies to enrich circulating breast cancer cells facilitates their detection

Objective. Metastatic relapse due to early dissemination of tumor cells is associated with poor prognosis for epithelial cancer. The molecular characterization of these single cells or cell clusters that have evaded the tumor is indispensable in order to evaluate their biological behavior and metastatic potential. In this study, we established a sensitive immunomagnetic method to isolate rare cancer cells from peripheral blood based on their expression of epithelial- or tumor-cell-specific markers. Methods. Low numbers of cells of breast cancer cell lines – ZR-75-1, MCF-7, HBL-100 – were spiked into peripheral blood specimens of healthy volunteers. Enrichment of tumor cells was performed using either pre-coupled HEA and/or ErbB2 microbeads or a mixture of three monoclonal antibodies against HEA, ErbB2 and EGFR. Results. The recovery rate of spiked tumor cells correlated with the expression of the corresponding antigens. ZR-75-1 cells high expressing all three genes could be isolated to 60–71%. MCF-7 cells, which hardly express EGFR, showed a significant better recovery by using two specific antibodies in combination (50–68%) than one pre-coupled bead alone (31–42%). HBL-100 cells little expressing HEA could not be isolated with HEA microbeads and only to 27% in combination with ErbB2 beads —in contrast the use of an antibody cocktail achieved 38%. Conclusion. As tumor and epithelial specific cell marker antigens are expressed differently in disseminated tumor cells, the immunomagnetic enrichment from peripheral blood is most robust and reliable when using a combination of specific antibodies compared to single antibodies.

Fluctuations in the occurrence of Escherichia coli O157:H7 on a Norwegian farm*

To describe the distribution of Escherichia coli O157:H7 on a sporadically positive dairy farm and on possible contact farms over a one-year period. Environmental and faecal samples from all animals at the farm, and faecal samples from animals at contact farms were analysed for E. coli O157:H7 by immunomagnetic separation methods or VIDAS. Confirmed isolates were tested for cytotoxicity in the Vero cell assay and typed by PFGE. Escherichia coli O157:H7 (stx2 and eae) of the same PFGE type were isolated from cattle, sheep, hens and environmental samples at variable levels during summer and fall 2002, but were not detected in 2003. Escherichia coli O157:H7 had a widespread distribution on the farm investigated, but the original source of contamination could not be identified. The occurrence of this bacterium on the farm did not result in any detectable increase in gastrointestinal disease in the associated population. Despite a low endemic level of E. coli O157:H7 in the Norwegian cattle population, the growth and spread of this potentially important bacterium may occur.

Reduction of Escherichia coli O157 in Finishing Beef Cattle by Various Doses of Lactobacillus acidophilus in Direct-Fed Microbials

Our objective was to evaluate the effects of three doses of Lactobacillus acidophilus strain NP51 and a combination treatment of strains NP51 and NP45 on prevalence of Escherichia coli O157 in cattle. Three hundred steers were assigned randomly to 60 pens (five steers per pen) and received one of five treatments: (i) control, no added direct-fed microbial; (ii) HNP51, high dose of NP51 at 109 CFU per steer daily; (iii) MNP51, NP51 at 108 CFU per steer daily; (iv) LNP51, low dose of NP51 at 107 CFU per steer daily; and (v) NP51+45, NP51 at 109 CFU per steer daily and NP45 at 106 CFU per steer daily. All direct-fed microbial treatments included Propionibacterium freudenreichii at 109 CFU per steer. Individual rectal fecal samples were collected on arrival and every 28 days throughout the feeding period. Fecal and hide samples were collected on the day of harvest. Samples were analyzed for presence of E. coli O157 using immunomagnetic separation methods. Cattle receiving HNP51, MNP51, and LNP51 had a lower prevalence (P < 0.01) of E. coli O157 throughout the feeding period compared with the controls, and the dose response for NP51 was a linear decrease in prevalence with increasing dose (P < 0.01). No decrease in prevalence for cattle receiving the combination NP51+45 was detected compared with controls (P = 0.15). E. coli O157 prevalences averaged across collection times were 23.9, 10.5, 9.9, 6.8, and 17.3% for cattle in the control, LNP51, MNP51, HNP51, and NP51+45 groups, respectively. Least squares mean estimates of fecal prevalence at harvest of E. coli O157 were 31.7, 12.5, 17.4, 8.2, and 41.6% among cattle in the control, LNP51, MNP51, HNP51, and NP51+45 groups, respectively. Least squares mean estimates of the percentage of positive hide samples at harvest were 8.7, 5.9, 4.8, 3.4, and 8.6% among cattle in the control, LNP51, MNP51, HNP51, and NP51+45 groups, respectively. The greatest decrease in E. coli O157 carriage was achieved using NP51 at 109 CFU per steer.

Detection of Giardia cysts in sewage and estimations of giardiasis prevalence among inhabitants in Hyogo Prefecture, Japan

We recovered Giardia cysts from sewage and estimated the prevalence of giardiasis among inhabitants in Hyogo Prefecture, western Japan. Two 200-ml sewage samples were collected once a month from two different sewage plants (A and B) during a one-year period. After pretreating the samples by filtration and centrifugation in the presence of alcohol and diethyl ether, an immunomagnetic separation method was applied to isolate Giardia cysts. The mean number of cysts recovered from plants A and B were 880⁄L and 2,000⁄L, respectively. Circadian rhythms in the number of cysts detected on each of two examination days were observed with a peak at 10:00 a.m., and seasonal variations in cyst numbers were also observed with two peaks in May and December. By using the data obtained from this survey, we estimated that the prevalence of Giardia infection in habitants in the areas serviced by plants A and B were 0.1-1.1 and 0.1-1.3%, respectively.

Cyclosporine A, FK-506, 40-0-[2-hydroxyethyl]rapamycin and mycophenolate mofetil inhibit proliferation of human intrahepatic biliary epithelial cellsin vitro

To investigate the effect of cyclosporine A (CsA), FK-506, and mycophenolate mofetil (MMF) and 40-0-[2-hydroxyethyl]rapamycin (RAD) on proliferation of human intrahepatic biliary epithelial cells (BECs) in vitro. BECs were isolated from six human liver tissuespecimens with the immunomagnetic separation method and treated with different concentrations of CsA, FK-506, RAD, and MMF in vitro. Proliferation of the cells was measured by MTT assay at 24 and 48 h after treatment, respectively. One-way analysis of variance was used to analyze the results. Expression of CK 19 in BECs was monitored by flow cytometry and Western blot. Six lines of BECs were established. They survived for 4-18 wk in vitro. Flow cytometry analysis showed that these cells always expressed CK19. CsA, FK-506, RAD, and MMF inhibited proliferation of BECs in a dose-dependent manner. The lowest concentration of CsA, FK-506, RAD, and MMF to inhibit proliferation of BECs (P<0.05) was 500, 100, 0.25, and 100 mug/L, respectively. However, the expression of CK19 by BECs was not changed. CsA, FK-506, RAD, and MMF have an antiproliferative effect on human intrahepatic BECs in vitro, while RAD has the strongest growth-inhibitory effect. Their possible effects on liver regeneration and bile duct injury in transplant patients should be further investigated.

Human ???? T Cells From G-CSF-Mobilized Donors Retain Strong Tumoricidal Activity and Produce Immunomodulatory Cytokines After Clinical-Scale Isolation

Human gammadelta T cells are a small fraction of T cells that have been shown to exert major histocompatibility (MHC)-unrestricted natural cytotoxicity against a variety of solid tumors and some subsets of leukemias and lymphomas. They are also involved in the immune response to certain bacterial, viral, and parasitic infections and expand significantly in CMV- or HSV-infected organ allografts. They are able to mediate antibody-dependent cytotoxicity and are not alloreactive, which makes them attractive candidates for cell-based immunotherapy. However, their frequency in peripheral blood is low and ex vivo expansion of gammadelta T cells is labor-extensive, does not always yield cells with full innate cytotoxic power, and has the potential for microbial contamination. Therefore, the authors developed a clinical-scale, automated cell purification method for the efficient enrichment of gammadelta T cells from leukapheresis products. Six leukapheresis products were purified for gammadelta T cells using a single-step immunomagnetic method. Purity and phenotype were assessed by flow cytometry. A standard Europium release assay was performed to determine the cytotoxic capacity of the cells. Cytokine production was measured using a multiplex sandwich immunoassay. The mean percentage of gammadelta T cells in the final product was 91%, with an average recovery of 63%. The cells showed a high co-expression of CD8, CD56, CD28, and CD11b/CD18. In some products an unusually high proportion of Vgamma9Vdelta1 T cells was found. The isolated cells were cytotoxic against the neuroblastoma cell line NB1691 and the erythroleukemic line K562 in vitro. They were able to produce a variety of immunomodulatory cytokines such as IFNgamma, TNFalpha, and MIP-1beta, but also GM-CSF and G-CSF when co-incubated in culture with and without various stimuli. In summary, the authors describe a rapid, automated, and efficient method for the large-scale enrichment of human gammadelta T cells. The cytotoxic properties of the cells were preserved. This method yields sufficient purified gammadelta T cells for use in adoptive immunotherapy as well as laboratory investigations and animal studies.

Combined use of an immunomagnetic separation method and immunoblotting for the enumeration and isolation of Escherichia coli O157 in wastewaters

The detection of Escherichia coli O157:H7 in environmental samples is a human concern. The high persistence of this serotype in the environment suggests that contaminated animal wastewater could act as a potential reservoir. Nevertheless, the high levels of background microflora and cell damage because of environmental stress hamper the isolation of this pathogen without using enrichment methods. This study develops a method for the detection of E. coli and investigates its prevalence in animal and human wastewaters. Incubation of the sample for 1 h 30 min at 37 degrees C in peptone water supplemented with vancomycin and cefsulodin, enhanced the recovery of bacteria whilst ensuring that no growth occurred. Subsequently, a combination of immunomagnetic separation, cefixime-tellurite-sorbitol MacConkey (CT-SMAC) plating and immunoblotting with specific O157 antibodies allowed the detection, enumeration and isolation of E. coli O157 strains in human, swine and cattle wastewaters, which presented values of 0.2, 0.4, and 1.0 log10 ml(-1) units, respectively. Some of the isolates carried genes coding for Shiga toxins, intimin and enterohemolysin. Escherichia coli O157 is commonly present in animal and human wastewaters. The developed method reduced the high rate of false positives reported for other technical approaches. The confirmation of serotype by specific immunomethods is necessary to prevent false-positive detection and incorrect enumeration.

Further Studies of Galectin-1 (Gal-1) on CD34+ Umbilical Cord Blood Cells.

The galectins are a family of carbohydrate-binding proteins that are distributed widely in vertebrate organisms. Each galectin exhibits a specific pattern of expression in various cells and tissues. Although these proteins are found mainly in the cytoplasm, some of them are secreted from cells and interact with other glycosylated molecules at the cell surface or with the extracellular matrix. There is no information about the interaction of Gal-1 and hematopoietic progenitor cells (HPC). We studied the effect of rat recombinant galectin-1 (rGal-1) on the clonogenic capability and the morphologic differentiation of the human umbilical cord blood HPC in methylcellulose cultures. The quantification of total anti-Gal-1 binding capability (total receptors) was also determined by flow citometry. First, the cells of 10 human cord blood units were collected and CD34+ selected using an indirect immunomagnetic method (MidiMACS, Miltenyi, Biotec). Ten thousand events were acquired in a flow cytometer (FACScan, Becton Dickinson), employing 105 CD34+ cells, rabbit anti Gal-1 antiserum and anti-rabbit IgG FITC antibody. Finally the CD34+ cells were cultured in a semisolid methylcellulose medium (Methocult GF+ H4435, StemCell) by triplicate at 37°C, 5% CO2 and 100% humidity during 14 days, employing 24 wells culture plates (Nunc) in presence or not of different concentrations of rGal-1 (2, 4, 6 and 20 μg/ml). We analyzed the number of GEMM-CFU (mix colonies), GM-CFU (granulocyte- macrophage colonies), BFU-E (erythroid colonies) and the presence of signals of abnormal morphologic differentiation. Control of inhibition with thiodigalactoside (TDG) and lactose (Lac) 100 mM was done in every case to determine the assay specificity. Histograms show a total receptor mean expression (mean+/−SEM) in CD34+ cells of 18.2+/−2.44% which was significantly inhibited (p<0.05) with TDG (8.8+/−0.98%) and Lac (13.5+/−3.70%). A statistically significant increase in the number of GEMM-CFU, GM-CFU and BFU-E was seen. These increases were directly proportional to the rGal-1 concentration added (p<0.05) and it was stronger for GM-CFU. This effect was partially inhibited by TDG and Lac. We observed an abnormal increase in the mesenchymal, fibroblastic-like cell growth in methylcellulose cultures. These results showed the expression of Gal-1 in CD34+ human umbilical blood cells membranes. The addition of rGal-1 to cultures would increase the proliferation of HPC and the differentiation to stromal-like cells would partially occur. The mechanism and functional meaning of this activation and differentiation must still been elucidated.

The detection of Cryptosporidium parvum and Escherichia coli O157 in UK bivalve shellfish

Optimised immunomagnetic separation methods to detect Cryptosporidium parvum and Escherichia coli O157 in UK shellfish are described. Whole tissue homogenates gave the best recoveries for C. parvum oocysts compared with gill or haemolymph extracts. The sensitivity of recovery from spiked samples was comparable to that achieved when processing water and varied from 12–34% in mussels, 48–69.5% in oysters and 30–65% in scallops. Maximum recovery of E. coli O157 was achieved by enriching in buffered peptone water supplemented with vancomycin at 42 °C. Increasing enrichment temperatures from 37 to 42 °C gave a significant increase in target number recovery. Implementation of these methods into monitoring programmes and end-product testing will enable shellfish producers to better assess product safety.

Phenotype and function of human natural killer cells purified by using a clinical-scale immunomagnetic method.

Infection, disease relapse, graft failure, and graft-versus-host disease (GVHD) are significant adverse events associated with allogeneic bone marrow transplantation. Donor natural killer (NK) cells may be an ideal cell type for prevention or treatment of all these adverse events. Therefore, we investigated the phenotype and function of human NK cells purified by using a clinical-scale immunomagnetic method. We found that the NK cell purification procedures did not adversely affect the expression of killer cell immunoglobulin-like receptors, adhesion molecules, intracellular cytokines, perforin, and granzyme B. Purified NK cells had extensive proliferative capacity and potent antitumor activity when assessed using an immunodeficient mouse model. While all mice transplanted with unpurified mononuclear cells developed GVHD, none of the mice transplanted with purified NK cells did. NK cells were highly susceptible to lysis by antithymocyte globulin (ATG), whereas G-CSF had a minimal effect on their natural cytotoxicity. These results support future clinical investigation of the use of purified NK cells for adoptive immunotherapy in the absence of ATG.

Acetaldehyde Induces Histamine Release from Human Airway Mast Cells to Cause Bronchoconstriction

Backgrounds: Approximately half of the Japanese asthmatics experience exacerbation of asthma after alcohol consumption. We previously reported that this phenomenon is probably caused by histamine release from mast cells by acetaldehyde stimulation. However, no reports have described the effects of acetaldehyde on human airway mast cells. The purpose of the present study was to demonstrate acetaldehyde-induced histamine release from human airway mast cells with subsequent airway smooth muscle contraction and to investigate the ensuing mechanisms. Methods: Human tissue samples were prepared from the lungs resected from patients with lung cancer. The effect of acetaldehyde on airway muscle tone and the concentration of chemical mediators released in the organ bath were measured before and after acetaldehyde stimulation. Mast cells were prepared from lung parenchyma by the immunomagnetic method and then stimulated with acetaldehyde to determine the chemical mediators released. Results: Acetaldehyde (>3 × 10^–4M) increased airway muscle tone, which was associated with a significant increase in the release of histamine, but not thromboxane B₂ or cysteinyl-leukotrienes. A histamine (H₁ receptor) antagonist completely inhibited acetaldehyde-induced bronchial smooth muscle contraction. Acetaldehyde also induced a significant histamine release from human lung mast cells and degranulation of mast cells. Conclusions: The present results strongly suggest that acetaldehyde stimulates human airway mast cells to release histamine, which may be involved in bronchial smooth muscle contraction following alcohol consumption.

Immunomagnetic detection and clinical significance of micrometastatic tumor cells in malignant melanoma patients.

Positive associations between the presence of micrometastatic tumor cells and disease aggressiveness have been reported in several tumor types, but the clinical implications are still not established. We wanted to test a new, sensitive immunomagnetic detection method on bone marrow (BM) and peripheral blood (PB) samples from patients with malignant melanoma and relate the findings to clinical outcome. Samples from 210 patients admitted for relapse of cutaneous melanoma were examined. Mononuclear cell fractions isolated from BM and PB were incubated with superparamagnetic particles coated with antimelanoma antibodies. Live tumor cells with bound beads were isolated with a magnet and identified in a microscope as cell-bead rosettes. Beads without antibody or with an irrelevant antibody were used as controls. The whole procedure was completed within 2-3 h. The identity of the cells was confirmed with a new double labeling procedure with fluorescent microparticles. Rosetted melanoma cells were found in BM aspirates of 35 of 186 (19%) patients, but in only 2 of 208 (1%) PB samples. The controls were all negative. After a median observation time of 1.1 year (range, 0-6.8 years), patients with tumor cells in BM showed a significantly shorter overall survival from time of BM aspiration (P = 0.009). In multiple regression analysis, a positive BM test was a strong indicator of overall survival (P = 0.021), associated with disease stage (American Joint Committee on Cancer) and with the number of metastatic sites, but not with the primary (Breslow) tumor depth and morphology. The results demonstrate the prognostic significance of detecting BM micrometastasis in melanoma patients. The results strengthen the validity of the immunobead technique. In contrast to other techniques, the method identifies intact, live tumor cells that can be further characterized, making the assay attractive for extended use.

Micronucleus induction in human B and T lymphocytes separated by an immunomagnetic technique.

Micronuclei were induced in human lymphocytes by mitomycin C or gamma radiation. After the incubation the cells were separated in B- and T-cells by an immunomagnetic method, i.e., Dynabeads. The cultures were stimulated by PHA. The effect of different incubation times (60-110 h) as well as different doses of mitomycin C (0-100 nmol/l) and gamma radiation (0-2 Gy) at an incubation time of 72 h were studied. There were significantly higher frequencies of micronuclei in B- than in T-cells, when micronuclei were induced by mitomycin C. This was not found with gamma radiation, probably because of a cytotoxic effect of this agent on the B-cells.

Pathogenesis of jumping translocations: a molecular cytogenetics study

Background/ aims: Jumping translocations are rare cytogenetic aberrations in haematological malignancies, the pathogenesis of which remains to be fully characterised. We investigated the mechanism of formation of jumping translocations in a case of adult common acute lymphoblastic leukaemia (ALL) positive for the Ph translocation. Methods: Interphase and metaphase fluorescence in situ hybridisation (FISH) was performed using several probe systems. Results were correlated with findings on conventional cytogenetics. Granulocytes, T-cells and leukaemic B-cells in peripheral blood were sorted by immunomagnetic method and the terminal restriction fragment (TRF) length of these cellular populations was determined by Southern blot analysis. Results: Duplicated BCR–ABL fusion signals were found on a dic(14;22)der(22)t(9;22) chromosome. Clonal jumping translocations, existing as evolutionary changes, involved the donor chromosomal segment distal to 1q12 jumping onto the telomere ends of 11q, 15p, 19p and 20p. Telomere length was decreased in the neoplastic B-cell population and contributed to the formation of the dicentric chromosome that showed absence of telomere repeats at fusion ends. Subsequent pericentromeric heterochromatin decondensation of chromosome 1q occurred, and this donor segment was randomly fused to the shortened telomere ends of non-homologous chromosomes. Conclusions: Both telomere shortening and pericentromeric heterochromatin decondensation contribute to the formation of jumping translocations, which is most probably a multi-stage process.

Evaluation of an automated immunomagnetic separation method for the rapid detection of Salmonella species in poultry environmental samples

Automated immunomagnetic separation (AIMS), using Dynabeads™ anti- Salmonella (Dynal, Oslo), was evaluated for its ability to detect Salmonella spp. in poultry environmental samples in comparison with standard, culture-based method (Health Canada, Health Protection Branch, MFHPB-20). AIMS was found to be more reliable in detecting Salmonella from artificially inoculated enrichment broths at low levels and exhibited a 15.5% higher sensitivity value than the culture method.

Evaluation of an automated immunomagnetic separation method for the rapid detection of Salmonella species in poultry environmental samples

Automated immunomagnetic separation (AIMS), using Dynabeads™ anti-Salmonella (Dynal, Oslo), was evaluated for its ability to detect Salmonella spp. in poultry environmental samples in comparison with standard, culture-based method (Health Canada, Health Protection Branch, MFHPB-20). AIMS was found to be more reliable in detecting Salmonella from artificially inoculated enrichment broths at low levels and exhibited a 15.5% higher sensitivity value than the culture method.