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Techniques to Evaluate Damage and Pain on Injection
Published in Sandeep Nema, John D. Ludwig, Parenteral Medications, 2019
Srinidi Mohan, Gayle A. Brazeau, Pramod Gupta
Silva and colleagues reported a tissue reactivity model that can be useful to look at biocompatibility or toxicity of biomaterials, parenteral formulations, or delivery systems [33]. In this experimental system, L-929 cells are grown to near-confluent monolayers followed by removal of the culture medium which is replaced with agar-containing medium and neutral red vital stain (marker of cell viability). Following solidification of the agar, the treatment is placed on the cells with control treatments (on filter paper), and the cells are then incubated for 24 h at 37°C. The culture can be evaluated microscopically around the treatments, and toxicity is measured by the loss of the vital stain. The investigator is able to evaluate the biological reactivity (cellular degeneration, lysis, malformation, and sloughing) by calculating a zone index with a range of reactivity of the treatment ranging from 0 with no detectable zone around the sample to 5, which involves the entire dish (as the numerator), and a lysis index ranging from none to severe (80% of the zone affected) as the denominator for the controls and treatments. It is critical to include the appropriate positive and negative control treatments in this system [30].
Biomedical Applications V: Influence of Carbon Nanotubes in Neuronal Living Networks
Published in Giorgia Pastorin, carbon nanotubes, 2019
SWNTs were functionalised with either PABS11 or polyethylene glycol (PEG, n ≈ 13)15 to form the corresponding graft copolymers (Scheme 6.1, paths B and D). Each polymer imparted water solubility to the SWNTs. The methodology used for the functionalisation was based on amidation of the COOH functions located at the nanotube ends. Hippocampal neuronal cells were cultured on the water-soluble SWNT substrates. The neurons accumulated the vital stain calcein, which is indicative of cell viability and of the biocompatibility of the functionalised SWNTs. The copolymers were found to modulate neurite outgrowth by increasing their length, while reducing the number of neuntes and growth cones (Scheme 6.2c). Hence, the neurons treated with the water- soluble SWNTs exhibited sparser, but longer neuntes.
Applications
Published in Raj P. Chhabra, CRC Handbook of Thermal Engineering Second Edition, 2017
Joshua D. Ramsey, Ken Bell, Ramesh K. Shah, Bengt Sundén, Zan Wu, Clement Kleinstreuer, Zelin Xu, D. Ian Wilson, Graham T. Polley, John A. Pearce, Kenneth R. Diller, Jonathan W. Valvano, David W. Yarbrough, Moncef Krarti, John Zhai, Jan Kośny, Christian K. Bach, Ian H. Bell, Craig R. Bradshaw, Eckhard A. Groll, Abhinav Krishna, Orkan Kurtulus, Margaret M. Mathison, Bryce Shaffer, Bin Yang, Xinye Zhang, Davide Ziviani, Robert F. Boehm, Anthony F. Mills, Santanu Bandyopadhyay, Shankar Narasimhan, Donald L. Fenton, Raj M. Manglik, Sameer Khandekar, Mario F. Trujillo, Rolf D. Reitz, Milind A. Jog, Prabhat Kumar, K.P. Sandeep, Sanjiv Sinha, Krishna Valavala, Jun Ma, Pradeep Lall, Harold R. Jacobs, Mangesh Chaudhari, Amit Agrawal, Robert J. Moffat, Tadhg O’Donovan, Jungho Kim, S.A. Sherif, Alan T. McDonald, Arturo Pacheco-Vega, Gerardo Diaz, Mihir Sen, K.T. Yang, Martine Rueff, Evelyne Mauret, Pawel Wawrzyniak, Ireneusz Zbicinski, Mariia Sobulska, P.S. Ghoshdastidar, Naveen Tiwari, Rajappa Tadepalli, Raj Ganesh S. Pala, Desh Bandhu Singh, G. N. Tiwari
Exposure to temperatures above normal physiologic ranges (>42°C) over time can result in measurable irreversible changes in tissue structure or function. Cell death or tissue alterations may be detrimental—for example, skin burns—or beneficial, as in vessel sealing or tumor destruction. Tissues of the central nervous system are the most thermally sensitive, exhibiting irreversible changes for long-term exposures above about 42°C. The specific pathologic end point may be evaluated histologically, histochemically, and/or physiologically. Most assays of thermal alterations are qualitative in nature; however, several end points that are inherently quantitative lend themselves well to rate process descriptions of their thermal kinetics. Examples of quantitative assays99 include loss of birefringence, vital stain uptake, fluorescent stains, gene expression, apoptosis, necroptosis, traumatic necrosis, and loss of clonogenicity (in cancer cells). Even for qualitative processes, thermal kinetic models often provide useful descriptions and so provide helpful insights into the underlying principles of tissue thermal damage.
Spectral analysis and biological activity assessment of silver doped hydroxyapatite
Published in Journal of Asian Ceramic Societies, 2021
Umit Erdem, Busra Moran Bozer, Mustafa B. Turkoz, Aysegul U. Metin, Gurcan Yıldırım, Mustafa Turk, Saffet Nezir
For the test method, L929 fibroblast cells and osteoblast cells stained with neutral red were used. This method was used for testing the nonspecific cytotoxicity of leachable components belonging to the test substances after diffusion through agar or agarose (ISO 7405) using permanent cell lines red vital stain dye coated with an agar layer on the cell. All the cell lines (2 × 105 cells/well) were seeded into the sterile flat-bottomed 6-well plates (each well is 34.8 mm) containing DMEM with 10% FBS supplemented with 1% PS and %1 l-glutamine and incubated overnight at 37°C and 5% CO2-humidified atmosphere for 24 h. After discarding the medium, the agar medium was prepared on the cells for applying the samples. Here, the agar medium was composed of 50% agar and 50% DMEM allowed to gel at room temperature for 30 min. Neutral red was applied to the gelled agar medium, protected from light, and left for staining for 15 min. Neutral rejection was removed from the medium, and the extracts of 2, 5, and 10% Ag-doped HAp were applied to a concentration of 1/1 (100%) on the discs obtained from a 5 mm pre-filter and new systems were exposed to the incubation process for 24 h. In this experiment, the presence of leachable toxic substances is manifested by a change in the color of the dye (a type of membrane integrity test) during the lysis of cells (a type of membrane integrity test) as a result of the fact that both the concentrations of diffusing agents and cytotoxicity are high enough. Thus, it can be revealed that it is simple and inexpensive to use as a cytotoxicity determination method.
Springtails (Collembola, Hexapoda) from Montebello Lakes, Chiapas, Mexico
Published in Inland Waters, 2018
José G. Palacios-Vargas, Daniela Cortés-Guzmán, Javier Alcocer
Finally, the bottom of the lakes does not seem to be attractive for collembolan colonization. At first glance, one could conclude that our results may be due to sample contamination, as has been reported by Deharveng and Lek (1995) for riparian collembolans, but our sampling methodology allows us to reject this assumption. In all cases, the samples were taken at vegetation-free sites, and most of the specimens (29,≈67%) were collected from the deepest stations in the lakes, which were ~100–500 m offshore. In addition, contamination was unlikely during the displacement of the dredge along the water column, and the samples were screened away from vegetation and immediately stored in containers. Finally, the organisms were in good condition and showed no signs of decay; based on Bengal Rose (a vital stain) staining, they were alive at the time of collection. The samples were composed of mature (17) as well as immature (26) individuals; their guts ranged from totally filled to totally emptied, and the items we could identify in the gut content were hyphae and conidia of Cladosporium sp. (Fungi: Ascomycota: Davidiellaceae).
Giardia spp. cysts and Cryptosporidium spp. oocysts in drinking water treatment residues: comparison of recovery methods for quantity assessment
Published in Environmental Technology, 2021
Kamila Jessie Sammarro Silva, Lyda Patricia Sabogal-Paz
Detection method by the immunofluorescence assay (IFA) coupled to PI staining in dried slides may have also affected membrane integrity, as described in Robertson et al. [37], who compared an increase in PI uptake when this vital stain was added to (oo)cysts after drying samples. In the present research, this effect is incorporated into the entire procedure of recovering and visualizing microorganisms. Nevertheless, PI staining in suspension and its possible correlation to excystation or infectivity is recommended for further research with the aims of investigating viability.