Automated cell counting of astrocytes on patterned substrates containing aliphatic and charged properties

Author(s):  
W. Shain ◽  
H. Ancin ◽  
H.C. Craighead ◽  
M. Isaacson ◽  
L. Kam ◽  
...  

Neural protheses have potential to restore nervous system functions lost by trauma or disease. Nanofabrication extends this approach to implants for stimulating and recording from single or small groups of neurons in the spinal cord and brain; however, tissue compatibility is a major limitation to their practical application. We are using a cell culture method for quantitatively measuring cell attachment to surfaces designed for nanofabricated neural prostheses.Silicon wafer test surfaces composed of 50-μm bars separated by aliphatic regions were fabricated using methods similar to a procedure described by Kleinfeld et al. Test surfaces contained either a single or double positive charge/residue. Cyanine dyes (diIC18(3)) stained the background and cell membranes (Fig 1); however, identification of individual cells at higher densities was difficult (Fig 2). Nuclear staining with acriflavine allowed discrimination of individual cells and permitted automated counting of nuclei using 3-D data sets from the confocal microscope (Fig 3). For cell attachment assays, LRM5 5 astroglial cells and astrocytes in primary cell culture were plated at increasing cell densities on test substrates, incubated for 24 hr, fixed, stained, mounted on coverslips, and imaged with a 10x objective.

2014 ◽  
Vol 89 (2) ◽  
pp. 1419-1427 ◽  
Author(s):  
Dongsheng Zhang ◽  
Pengwei Huang ◽  
Lu Zou ◽  
Todd L. Lowary ◽  
Ming Tan ◽  
...  

ABSTRACTTulane virus (TV), the prototype of theRecovirusgenus in the calicivirus family, was isolated from the stools of rhesus monkeys and can be cultivatedin vitroin monkey kidney cells. TV is genetically closely related to the genusNorovirusand recognizes the histo-blood group antigens (HBGAs), similarly to human noroviruses (NoVs), making it a valuable surrogate for human NoVs. However, the precise structures of HBGAs recognized by TV remain elusive. In this study, we performed binding and blocking experiments on TV with extended HBGA types and showed that, while TV binds all four types (types 1 to 4) of the B antigens, it recognizes only the A type 3 antigen among four types of A antigens tested. The requirements for HBGAs in TV replication were demonstrated by blocking of TV replication in cell culture using the A type 3/4 and B saliva samples. Similar results were also observed in oligosaccharide-based blocking assays. Importantly, the previously reported, unexplained increase in TV replication by oligosaccharide in cell-based blocking assays has been clarified, which will facilitate the application of TV as a surrogate for human NoVs.IMPORTANCEOur understanding of the role of HBGAs in NoV infection has been significantly advanced in the past decade, but direct evidence for HBGAs as receptors for human NoVs remains lacking due to a lack of a cell culture method. TV recognizes HBGAs and can replicatein vitro, providing a valuable surrogate for human NoVs. However, TV binds to some but not all saliva samples from A-positive individuals, and an unexplained observation of synthetic oligosaccharide blocking of TV binding has been reported. These issues have been resolved in this study.


2016 ◽  
Vol 82 (14) ◽  
pp. 4225-4231 ◽  
Author(s):  
Reimar Johne ◽  
Eva Trojnar ◽  
Matthias Filter ◽  
Jörg Hofmann

ABSTRACTHepatitis E virus (HEV) is an increasingly recognized zoonotic pathogen. Transmission is suspected to occur from infected pigs or wild boars to humans through direct contact, environmental pathways, or contaminated food. However, the physical and chemical stability of HEV is largely unknown, because suitable cell culture methods for infectivity measurement are missing. Here, we developed a titration method using infection of the cell line A549/D3 with HEV genotype 3 strain 47832c and subsequent counting of focus-forming units by immunofluorescence, which allowed HEV infectivity measurements within a 4-log-dilution range. Long-term storage of HEV in cell culture medium at different temperatures indicated a phase of rapid virus inactivation, followed by a slower progression of virus inactivation. Infective HEV was detected up to 21 days at 37°C, up to 28 days at room temperature, and until the end of the experiment (56 days) with a 2.7-log decrease of infectious virus at 4°C. Heat treatment for 1 min resulted in moderate decreases of infectivity up to 60°C, 2- to 3.5-log decreases between 65°C and 75°C, and no remaining virus was detected at temperatures of ≥80°C. Heating for 70°C resulted in a 3.6-log decrease after 1.5 min and the absence of detectable virus (>3.9-log decrease) after 2 min. The data were used to calculate predictive heat inactivation models for HEV. The results may help estimate HEV stability in the environment or food. The established method may be used to study other aspects of HEV stability in the future.IMPORTANCEIn this study, a cell culture method was developed which allows the measurement of hepatitis E virus (HEV) infectivity. Using this system, the stability of HEV at different time-temperature combinations was assessed, and a predictive model was established. The obtained data may help estimate HEV stability in the environment or food, thus enabling an assessment of the relative risks of HEV infection through distinct routes and by distinct types of food in the future.


Author(s):  
Giuseppe Guerrisi ◽  
Deborah Giordano ◽  
Anna Marabotti ◽  
Giancarlo Raiconi ◽  
Roberto Tagliaferri

Motivation: The term “cell culture” is generally referred to the process by which some cells, often derived from multicellular organisms or tissues, or tumoral cell lines, are grown under controlled conditions outside of their natural environment. This system is very useful for different applications, for example to study physiological phenomena, or for the production of some useful molecules, or for testing the toxicity of some compounds. The life of the cells in culture is conditioned by many elements. Apart from physical factors such as pH and temperature, the growth of a cell culture is conditioned by its density: cells compete for the nutrients and growth factors available and die when they are exhausted. Moreover, dead cells release in the medium some toxic factors that, in their turn, can lead the surrounding cells to death. Additionally, the presence of exogenous toxic factors in the medium can induce cell death We present a cellular automata developed in order to reproduce the growth of a cell culture of a particular human cell line, Caco-2, derived from human colorectal adenocarcinoma cells. The cellular automata has been developed in order to reproduce the phenotype of Caco-2 cells, their cell cycle with all phases, and the influence of 4-nonylphenol (4-NP), an environmental pollutant, on this model system. Methods: The cellular automata developed is a grid whose dimensions reproduce a cell counting Burker chamber. Two matrices have been used to take into account, respectively, the global duration of the cellular growth and the phase of the cell cycle for each cell. Two vectors are also introduced to take into account the length of each phase and their variability range. A shuffling algorithm is used to distribute the starting cells on the chamber, then the algorithm starts by assigning a variable lag phase before reproducing the start of the cell cycle with the entering of the cells in G1 phase. All the following phases of the cell cycle are characterized by a fixed length (in minutes) + 10% variability. The cell death is described by a logarithmic function that is influenced by different factors: culture density, cellular senescence, presence of dead cells in the environment of each cell, introduction of a toxic substance. The application was developed in a stand-alone manner and has been written in Java using the OpenGL library integrated in Java. Results The application is made by an intuitive GUI to set several parameters useful for the simulation (see Figure, panel A). In order to highlight the different cell cycle phases, different colors were attributed to each phase. The cellular automata is evolving in the space and in the time reproducing the four steps of the cell cycle (G1, S, G2, M). The evolution of the simulated cell growth reproduces the phenomena present in a real Caco-2 cell culture. (Abstract truncated at 3,000 characters - the full version is available in the pdf file)


1968 ◽  
Vol 1 (3) ◽  
pp. 255-261
Author(s):  
S. Abrahams ◽  
J. E. Till ◽  
E. A. McCulloch ◽  
L. Siminovitch

2020 ◽  
Vol 11 (2) ◽  
pp. 35-44
Author(s):  
Stephanie Tornberg-Belanger ◽  
Jonathan Sreter ◽  
Aaron Margolin

Enteroviruses are a public health threat due to the high incidence of infections and potential for serious illness or death. Some laboratories in high-income countries detect enteroviruses in water by integrating cell culture and PCR (ICC/PCR). This combined method carries a high financial burden, due in part to specialized cell culture equipment. Therefore, we expanded upon a pilot study to reduce the cost by using common laboratory polypropylene tubes to create a cell culture in suspension. We optimized the protocol by determining minimal incubation periods post-infection as a function of the initial virus concentration. Cells in suspension and traditional monolayers were inoculated with poliovirus and incubated in 8-hour intervals up to 48 hours prior to extraction. Quantitative PCR (qPCR) was used to detect viral nucleic acid targets. Treated and raw water samples were seeded with virus and the suspension ICC/qPCR protocol used to ascertain whether the protocol performed similar to directly seeding cells. No variation in virus detection occurred using the suspension ICC/qPCR or monolayer ICC/qPCR (p = 0.95). In surface water samples, viral nucleic acid was successfully detected, with no significant increase after 32 h (p > 0.05). Suspension ICC/qPCR is as effective as monolayer ICC/qPCR in detecting enteroviruses in surface waters. Materials used in the suspension ICC/qPCR have a lower monetary cost than traditional cell culture materials without loss of sensitivity. More accessible testing of waters for enterovirus contamination through cost reduction has the potential to reduce human exposure and disease.


2019 ◽  
Author(s):  
Ekasit Sonpho ◽  
Chanida Wootthichairangsan ◽  
Miyuki Ishida ◽  
Takeshi Inoue ◽  
Kiyokazu Agata ◽  
...  

AbstractExtracellular matrix (ECM) plays key roles in shaping fates of stem cells, not only by providing suitable niche but also by mediating physical and biochemical cues. Despite intensive investigations on regeneration, the roles of ECM on fate determination of stem cells in animal with great regenerative potency, such as planarian, remained unclear. Here, we developed a method to decellularizing and isolating extracellular matrix from planarians. Although the isolated scaffold appears translucent, it contains all the internal features, resembling the structure of intact planarian, and which we thus called “ECM-body”. Nuclear staining demonstrated that ECM-body contains very little or no cell remained. Histological sections displayed a well-preserved morphological integrity of the specimen. Scanning electron microscope showed porous surface on ECM-body, potentially suitable for housing cells. Furthermore, our preliminary experiment suggested that ECM-body can be utilized as biomimetic scaffold for cell culture as it may support survival of injected neoblasts.


Author(s):  
Giuseppe Guerrisi ◽  
Deborah Giordano ◽  
Anna Marabotti ◽  
Giancarlo Raiconi ◽  
Roberto Tagliaferri

Motivation: The term “cell culture” is generally referred to the process by which some cells, often derived from multicellular organisms or tissues, or tumoral cell lines, are grown under controlled conditions outside of their natural environment. This system is very useful for different applications, for example to study physiological phenomena, or for the production of some useful molecules, or for testing the toxicity of some compounds. The life of the cells in culture is conditioned by many elements. Apart from physical factors such as pH and temperature, the growth of a cell culture is conditioned by its density: cells compete for the nutrients and growth factors available and die when they are exhausted. Moreover, dead cells release in the medium some toxic factors that, in their turn, can lead the surrounding cells to death. Additionally, the presence of exogenous toxic factors in the medium can induce cell death We present a cellular automata developed in order to reproduce the growth of a cell culture of a particular human cell line, Caco-2, derived from human colorectal adenocarcinoma cells. The cellular automata has been developed in order to reproduce the phenotype of Caco-2 cells, their cell cycle with all phases, and the influence of 4-nonylphenol (4-NP), an environmental pollutant, on this model system. Methods: The cellular automata developed is a grid whose dimensions reproduce a cell counting Burker chamber. Two matrices have been used to take into account, respectively, the global duration of the cellular growth and the phase of the cell cycle for each cell. Two vectors are also introduced to take into account the length of each phase and their variability range. A shuffling algorithm is used to distribute the starting cells on the chamber, then the algorithm starts by assigning a variable lag phase before reproducing the start of the cell cycle with the entering of the cells in G1 phase. All the following phases of the cell cycle are characterized by a fixed length (in minutes) + 10% variability. The cell death is described by a logarithmic function that is influenced by different factors: culture density, cellular senescence, presence of dead cells in the environment of each cell, introduction of a toxic substance. The application was developed in a stand-alone manner and has been written in Java using the OpenGL library integrated in Java. Results The application is made by an intuitive GUI to set several parameters useful for the simulation (see Figure, panel A). In order to highlight the different cell cycle phases, different colors were attributed to each phase. The cellular automata is evolving in the space and in the time reproducing the four steps of the cell cycle (G1, S, G2, M). The evolution of the simulated cell growth reproduces the phenomena present in a real Caco-2 cell culture. (Abstract truncated at 3,000 characters - the full version is available in the pdf file)


Author(s):  
Parag A Pathade ◽  
Vinod A Bairagi ◽  
Yogesh S. Ahire ◽  
Neela M Bhatia

‘‘Proteomics’’, is the emerging technology leading to high-throughput identification and understanding of proteins. Proteomics is the protein equivalent of genomics and has captured the imagination of biomolecular scientists, worldwide. Because proteome reveals more accurately the dynamic state of a cell, tissue, or organism, much is expected from proteomics to indicate better disease markers for diagnosis and therapy monitoring. Proteomics is expected to play a major role in biomedical research, and it will have a significant impact on the development of diagnostics and therapeutics for cancer, heart ailments and infectious diseases, in future. Proteomics research leads to the identification of new protein markers for diagnostic purposes and novel molecular targets for drug discovery.  Though the potential is great, many challenges and issues remain to be solved, such as gene expression, peptides, generation of low abundant proteins, analytical tools, drug target discovery and cost. A systematic and efficient analysis of vast genomic and proteomic data sets is a major challenge for researchers, today. Nevertheless, proteomics is the groundwork for constructing and extracting useful comprehension to biomedical research. This review article covers some opportunities and challenges offered by proteomics.   


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