Flow Cytometry

Conventional methods to detect and assess the viability of plant pathogenic bacteria are usually based on plating assays or serological techniques. Plating assays provide information about the number of viable cells, expressed as colony-forming units, but are time-consuming and laborious. Serological methods, such as the enzyme-linked immunosorbent assay (ELISA) and immunofluorescence microscopy (IF), can be performed in a shorter timespan than most plating assays, but they do not discriminate between live and dead cells. Flow cytometry (FCM) in combination with fluorescent probe technology is a rapid, sensitive, and quantitative technique to detect microorganisms and assess their viability. Quantitative information on the presence and viability of plant pathogenic microorganisms is valuable for risk assessment regarding disease transmission and disease development. FCM has been applied successfully in the fields of food microbiology, veterinary science, and medical research to dete...

Aloe-emodin has shown anti-neoplastic activity against some human cancer cell lines. This study aimed to explore the effects of aloe-emodin on the phagocytosis of macrophages, the activity of natural killer (NK) cells and the expression of cytokines in leukocytes from Sprague-Dawley rats. Leukocytes were collected, placed into culture plates and the functions of macrophages and NK cells and the percentage of viable cells were determined by flow cytometric analysis. Incubation of leukocytes with various concentrations of aloe-emodin caused a dose-dependent decrease of viable cells, a decrease of phagocytosis by macrophages, and a decrease of the activity of NK cells. Evaluation of cytokines in leukocytes by ELISA indicated that aloe-emodin increased the levels of interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha. The results were also confirmed by PCR assay for the mRNA expression of the examined cytokines.

To evaluate the EasyCD4 assay, a less expensive method to enumerate CD4+ lymphocytes, in resource-limited settings. Cross-sectional study conducted in the United States and Uganda. We compared CD4+ cell counts obtained on replicate samples from HIV-infected patients by the EasyCD4 assay, a microcapillary flow-based system, and by standard flow cytometry or FACSCount with linear regression and the Bland-Altman method. Two hundred eighteen samples were analyzed (77 in the United States and 141 in Uganda). In the United States, mean +/- SD CD4 was 697 +/- 438 cells/microL by standard flow cytometry and 688 +/- 451 cells/microL by EasyCD4. In Uganda, the mean +/- SD CD4 was 335 +/- 331 cells/microL by FACSCount and 340 +/- 327 cells/microL by EasyCD4. The 2 methods were highly correlated (US cohort, r2 = 0.97, slope = 1.0, intercept = -18; Ugandan cohort, r2 = 0.92; slope = 0.95; intercept = 23). The mean differences in CD4 cell counts were 9.0 and -4.6 cells/microL for the US and Ugandan cohorts, respectively, and they were not significant in either cohort. In the Ugandan cohort, sensitivity and specificity of the EasyCD4 for CD4 below 200 cells/microL were 90% and 98%, respectively. Positive predictive value was 96%; negative predictive value was 93%. Our results suggest that EasyCD4 may be used with high positive and negative predictive value in resource-limited settings.

In this paper we consider the question of uncertainty of detected patterns in data mining. In particular, we develop statistical tests for patterns found in continuous data, indicating the significance of these patterns in terms of the probability that they have occurred by chance. We examine the performance of these tests on patterns detected in several large data sets, including

Special AT-rich sequence binding protein 1 (SATB1) is a genome organizer that is expressed by T cells. T cell development is severely impaired in SATB1 null mice; however, because SATB1 null mice die by 3 wk of age, the roles of SATB1 in T cell development have not been well clarified. In this study, we generated and analyzed SATB1 conditional knockout (cKO) mice, in which the SATB1 gene was deleted from all hematopoietic cells. T cell numbers were reduced in these mice, mainly because of a deficiency in positive selection at the CD4(+)CD8(+) double-positive stage during T cell development in the thymus. We also found that SATB1 cKO mice developed autoimmune diseases within 16 wk after birth. In SATB1 cKO mice, the numbers of Foxp3(+) regulatory T (Treg) cells were significantly reduced at 2 wk of age compared with wild-type littermates. Although the numbers gradually increased upon aging, Treg cells in SATB1 cKO mice were still less than those in wild-type littermates at adulthood....

Immunophenotyping, as suggested by WHO, may improve diagnosis of childhood leukemia since it offers a better classification of the hematopoietic lineage of malignant cells as compared to morphology. Therefore, we aimed to determine the proportion of the immunophenotypic subtypes of acute leukemia in Indonesian children. Samples were obtained from patients (0-14 years of age) in 4 hospitals in Indonesia. We analyzed 541 suspected leukemia samples presented over a 4-year period (March 2006 - July 2010) by flow cytometry. Immunophenotyping allowed classification into acute myeloid leukemia (AML) and ALL (B-lineage and T-lineage ALL). Of 541 samples, 136 were tested using a single color method and 405 with a three-color method. Concordance with morphology was very good (?=0.82) using the three-color method with a panel of 15 monoclonal antibodies (n=387). A relatively high percentage of acute leukemia was classified as AML (23%). Of the ALL samples 83% were B-lineage ALL and 17% T- line...

... The role of major histocompatibility complex class I antigens in tumorigenesis: future applications in cancer therapy. Auteur(s) / Author(s). NAPOLITANO L. (1) ; VOGEL J. ; JAY G. ; Affiliation(s) du ou des auteurs / Author(s) Affiliation(s). ... Tumor. ; Antígeno histocompatibilidad clase ...