Research into Neospora caninum-What Have We Learnt in the Last Thirty Years?

BACKGROUND:Neospora caninum has been recognised world-wide, first as a disease of dogs, then as an important cause of abortions in cattle for the past thirty years. Over that time period, there have been improvements in the diagnosis of infection and abortion, new tests have been developed and validated, and it is timely to review progress to date. METHODS:Bibliometric methods were used to identify major trends and research topics present in the published literature on N. caninum. The tools used were SWIFT-Review, VOSviewer and SciMAT, along with the published papers found in the MEDLINE, Dimensions and Web of Science databases. A systematic review of the published Neospora literature (n = 2933) was also carried out via MEDLINE and systematically appraised for publications relevant to the pathogenesis, pathology and diagnosis of Neospora abortions. RESULTS:A total of 92 publications were included in the final analysis and grouped into four main time periods. In these four different time periods, the main research themes were "dogs", "abortion", "seroprevalence" and "infection". Diagnostics, including PCR, dominated the first two time periods, with an increased focus on transmission and abortions, and its risk factors in cattle. CONCLUSIONS:Longitudinal analyses indicated that the main themes were consistently investigated over the last 30 years through a wide range of studies, with evolving emphasis initially on dogs and diagnostic test development, followed by application to cattle, the identification of the risk factors leading to abortion, and in the latter time periods, an understanding of the immunity and a search for vaccines

The development and evaluation of a nested PCR assay for detection of Neospora caninum and Hammondia heydorni in feral mouse tissues

The development of a novel nested polymerase chain reaction is described and used for detecting the presence of Neospora caninum and Hammondia heydorni DNA in DNA extracted from feral rodent tissues. A unique strategy was used for design of an assay that could be adapted for detecting DNA from more than one member of Toxoplasmatinae simultaneously with a minimal number of additional steps. The level of sensitivity described for this assay is comparable to real time-PCR and other nested PCR assays. Twenty-eight of 104 feral mice tested positive for N. caninum in at least one tissue (the brain, heart or liver) studied. In this study, eight instances are reported where the brain tested negative to N. caninum while at least one other tissue was positive. This suggests that prior studies, which screened only the brain, describe prevalence levels that are under-represented. None of 54 mouse brains tested positive for H. heydorni DNA. This suggests that mice are rarely infected by H. heydorni although this hypothesis needs to be explored further. Data obtained in the current study suggest that N. caninum is a common parasite of feral rodents which may be important in the epidemiology of the disease. © 2008 Elsevier Ltd. All rights reserved

Hollow Fiber Bioreactors for In Vivo-like Mammalian Tissue Culture

Tissue culture has been used for over 100 years to study cells and responses ex vivo. The convention of this technique is the growth of anchorage dependent cells on the 2-dimensional surface of tissue culture plastic. More recently, there is a growing body of data demonstrating more in vivo-like behaviors of cells grown in 3-dimensional culture systems. This manuscript describes in detail the set-up and operation of a hollow fiber bioreactor system for the in vivo-like culture of mammalian cells. The hollow fiber bioreactor system delivers media to the cells in a manner akin to the delivery of blood through the capillary networks in vivo. The system is designed to fit onto the shelf of a standard CO2 incubator and is simple enough to be set-up by any competent cell biologist with a good understanding of aseptic technique. The systems utility is demonstrated by culturing the hepatocarcinoma cell line HepG2/C3A for 7 days. Further to this and in line with other published reports on the functionality of cells grown in 3-dimensional culture systems the cells are shown to possess increased albumin production (an important hepatic function) when compared to standard 2-dimensional tissue culture

Evaluation of recombinant proteins of Neospora caninum as vaccine candidates (in a mouse model)

Abortion, resulting from infections by the parasite Neospora caninum, is a major cause of economic loss to both the dairy and beef industries of cattle-producing countries of the world. Vaccination as a means of preventing abortion and/or infection represents a viable control strategy; indeed a commercial vaccine is available in some countries, albeit of unknown efficacy. The commercial vaccine is based on inactivated tachyzoites of N. caninum but other approaches based on lysates and recombinant antigens of N. caninum may also be feasible. In this study we have used an immunisation/challenge model of transplacental transmission, based on the Qs mouse with an Nc-Liverpool challenge, to investigate the vaccine potential of a number of formulations based on four recombinant proteins of N. caninum (GRA1, GRA2, MIC10, and p24B). All formulations studied were immunogenic in the mouse when assessed by ELISA using sonicated tachyzoite antigen as the target antigen. In one experiment, a mixture of MIC10 and p24B produced partial protection against transplacental transmission of N. caninum in this mouse model; in contrast a live infection of tachyzoites of NC-Nowra given before pregnancy always induces very high levels of protective immunity. The field of vaccines against Neospora-associated abortion in cattle is discussed. © 2008 Elsevier Ltd. All rights reserved

A live vaccine against Neospora caninum abortions in cattle

CommentaryMichael P. Reichel, Dadín P. Moore, Andrew Hemphill, Luis M. Ortega-Mora, J.P. Dubey, John T. Elli

Hollow Fiber Bioreactors for In Vivo-like Mammalian Tissue Culture

Tissue culture has been used for over 100 years to study cells and responses ex vivo. The convention of this technique is the growth of anchorage dependent cells on the 2-dimensional surface of tissue culture plastic. More recently, there is a growing body of data demonstrating more in vivo-like behaviors of cells grown in 3-dimensional culture systems. This manuscript describes in detail the set-up and operation of a hollow fiber bioreactor system for the in vivo-like culture of mammalian cells. The hollow fiber bioreactor system delivers media to the cells in a manner akin to the delivery of blood through the capillary networks in vivo. The system is designed to fit onto the shelf of a standard CO2 incubator and is simple enough to be set-up by any competent cell biologist with a good understanding of aseptic technique. The systems utility is demonstrated by culturing the hepatocarcinoma cell line HepG2/C3A for 7 days. Further to this and in line with other published reports on the functionality of cells grown in 3-dimensional culture systems the cells are shown to possess increased albumin production (an important hepatic function) when compared to standard 2-dimensional tissue culture

A Multi-Armed Bandit to Smartly Select a Training Set from Big Medical Data

With the availability of big medical image data, the selection of an adequate training set is becoming more important to address the heterogeneity of different datasets. Simply including all the data does not only incur high processing costs but can even harm the prediction. We formulate the smart and efficient selection of a training dataset from big medical image data as a multi-armed bandit problem, solved by Thompson sampling. Our method assumes that image features are not available at the time of the selection of the samples, and therefore relies only on meta information associated with the images. Our strategy simultaneously exploits data sources with high chances of yielding useful samples and explores new data regions. For our evaluation, we focus on the application of estimating the age from a brain MRI. Our results on 7,250 subjects from 10 datasets show that our approach leads to higher accuracy while only requiring a fraction of the training data.Comment: MICCAI 2017 Proceeding

Mathematical modelling of a liver hollow fibre bioreactor

A mathematical model has been developed to assist with the development of a hollow fibre bioreactor (HFB) for hepatotoxicity testing of xenobiotics; specifically, to inform the HFB operating set-up, interpret data from HFB outputs and aid in optimizing HFB design to mimic certain hepatic physiological conditions. Additionally, the mathematical model has been used to identify the key HFB and compound parameters that will affect xenobiotic clearance. The analysis of this model has produced novel results that allow the operating set-up to be calculated, and predictions of compound clearance to be generated. The mathematical model predicts the inlet oxygen concentration and volumetric flow rate that gives a physiological oxygen gradient in the HFB to mimic a liver sinusoid. It has also been used to predict the concentration gradients and clearance of a test drug and paradigm hepatotoxin, paracetamol (APAP). The effect of altering the HFB dimensions and fibre properties on APAP clearance under the condition of a physiological oxygen gradient is analysed. These theoretical predictions can be used to design the most appropriate experimental set up and data analysis to quantitatively compare the functionality of cell types that are cultured within the HFB to those in other systems