Cytokines and chemokines production by mononuclear cells from parturient women after stimulation with live Toxoplasma gondii

AbstractToxoplasma gondii is an obligate intracellular parasite that can cause variable clinical symptoms or can even be asymptomatic in immunocompetent individuals. More severe symptoms are observed in immunocompromised patients and congenital transmission of the parasite has been reported. The objective of this study was to evaluate the response of peripheral blood mononuclear cells (PBMC) in parturient and non-pregnant women exposed to live tachyzoites of T. gondii strain RH or ME49. PBMC were isolated from parturient and non-pregnant women with negative or positive serology for toxoplasmosis and cultured with live tachyzoites of the two T. gondii strains for 24 h. Next, the cell culture supernatants were collected and levels of CCL2, CCL5, IL-6, IL-10, IL-12, and TNF-α produced by PBMC after tachyzoite exposure were measured. Live tachyzoite forms of T. gondii significantly inhibited the synthesis of CCL2 in seropositive parturient women, whereas a stimulatory effect on CCL5 was observed in seronegative parturient women. Cells from T. gondii-seronegative non-pregnant women produced significantly higher levels of TNF-α and IL-12, demonstrating the proinflammatory profile induced by the presence of the parasite in culture. The results suggest that the immunomodulation seen during pregnancy contributes to the development of an environment that facilitates escape of the parasite from the immune response

A probabilistic compressive sensing framework with applications to ultrasound signal processing

The field of Compressive Sensing (CS) has provided algorithms to reconstruct signals from a much lower number of measurements than specified by the Nyquist-Shannon theorem. There are two fundamental concepts underpinning the field of CS. The first is the use of random transformations to project high-dimensional measurements onto a much lower-dimensional domain. The second is the use of sparse regression to reconstruct the original signal. This assumes that a sparse representation exists for this signal in some known domain, manifested by a dictionary. The original formulation for CS specifies the use of an penalised regression method, the Lasso. Whilst this has worked well in literature, it suffers from two main drawbacks. First, the level of sparsity must be specified by the user, or tuned using sub-optimal approaches. Secondly, and most importantly, the Lasso is not probabilistic; it cannot quantify uncertainty in the signal reconstruction. This paper aims to address these two issues; it presents a framework for performing compressive sensing based on sparse Bayesian learning. Specifically, the proposed framework introduces the use of the Relevance Vector Machine (RVM), an established sparse kernel regression method, as the signal reconstruction step within the standard CS methodology. This framework is developed within the context of ultrasound signal processing in mind, and so examples and results of compression and reconstruction of ultrasound pulses are presented. The dictionary learning strategy is key to the successful application of any CS framework and even more so in the probabilistic setting used here. Therefore, a detailed discussion of this step is also included in the paper. The key contributions of this paper are a framework for a Bayesian approach to compressive sensing which is computationally efficient, alongside a discussion of uncertainty quantification in CS and different strategies for dictionary learning. The methods are demonstrated on an example dataset from collected from an aerospace composite panel. Being able to quantify uncertainty on signal reconstruction reveals that this grows as the level of compression increases. This is key when deciding appropriate compression levels, or whether to trust a reconstructed signal in applications of engineering and scientific interest

Toxoplasmosis serology: an efficient hemagglutination procedure to detect IgG and IgM antibodies

In search of an efficient but simple, low cost procedure for the serodiagnosis of Toxoplasmosis, especially suited for routine laboratories facing technical and budget limitations as in less developed countries, the diagnostic capability of Hematoxo® , an hemagglutination test for toxoplasmosis, was evaluated in relation to a battery of tests including IgG- and IgM-immunofluorescence tests, hemagglutination and an IgM-capture enzymatic assay. Detecting a little as 5 I.U. of IgG antitoxoplasma antibodies, Hematoxo® showed a straight agreement as to reactivity and non-reactivity for the 443 non-reactive and the 387 reactive serum samples, included in this study. In 23 cases presenting a serological pattern of acute toxoplasmosis and showing IgM antibodies, Hematoxo® could detect IgM antibodies in 18, indicated by negativation or a significant decrease in titers as a result of treating samples with 2-mercapto-ethanol. However, a neat increase in sensitivity for IgM specific antibodies could be achieved by previously removing IgG from the sample, as demonstrated in a series of acute toxoplasmosis sera. A simple procedure was developed for this purpose, by reconstituting a lyophilized suspension of Protein A - rich Staphylococcus with the lowest serum dilution to be tested. Of low cost and easy to perform, Hematoxo® affords not only a practical qualitative procedure for screening reactors and non-reactors, as in prenatal services, but also quantitative assays that permit to titrate antibodies as well as to identify IgM antibodies

Special Libraries, April 1933

Volume 24, Issue 3https://scholarworks.sjsu.edu/sla_sl_1933/1002/thumbnail.jp

Detecção pelo teste imunoenzimático ELISA de anticorpos IgM anti-Cysticercus cellulosae no líquido cefalorraqueano na neurocisticercose

Demonstrou-se a presença de anticorpos da classe IgM anti-C. cellulosaeem amostras de LCR de pacientes com neurocisticercose, pelo teste imunoenzimático ELISA. Este foi realizado em placas plásticas sensibilizadas com uma fração glicoproteica de cisticercos. Das 41 amostras de LCR estudadas, 26 pertenciam a pacientes com neurocisticercose, 5 a pacientes com neurossífilis e 10 a pessoas aparentemente normais. Nas 5 amostras de LCR de pacientes com neurossífilis e nas 10 de pessoas aparentemente normais foi negativo o teste ELISA-IgM. Dos 26 LCR de pacientes com neurocisticercose 12 (46,2%) apresentaram anticorpos IgM anti-C. cellulosaecom títulos que variaram de 4 a 32. Essas 12 amostras de LCR quando submetidas ao tratamento com 2-mercaptoetanol tornaram-se negativas no teste ELISA-IgM. Compararam-se os níveis de anticorpos IgM e IgG anti-C. cellulosaedetectados pelos respectivos testes imunoenzimáticos para todas as amostras estudadas e observou-se que, dos 12 LCR de pacientes com neurocisticercose reagentes pelos dois testes, dois apresentaram níveis de IgM mais elevados que de IgG. Paralelamente compararam-se os resultados dos testes ELISA com as reações de fixação do complemento, imunofluorescência e hemaglutinação para neurocisticercose