http://www.radio.cuci.udg.mx/bch/EN/Manuals/Techniques/Compare-LDH-NRU-MTT-Bradford_ToxLett_2006-v160-p171.pdf

In vitro cytotoxicity assays: comparison of LDH, neutral red, MTT and protein assay in hepatoma cell lines following exposure to cadmium chloride.

We describe the application of a simple, rapid, semi-automated assay to the sensitivity testing of cytotoxic drugs in 23 patients with acute myeloid leukaemia (AML). The survival of blast cells from the bone marrow was measured by the MTT assay after 48 h continuous exposure to drugs both singly and in combination. There was a linear relationship between the number of leukaemic cells and the optical density of the formazan produced. The assay demonstrated a variation in drug sensitivity between patients. The technique was reproducible and there was no significant difference in response between blast cells obtained from bone marrow or from peripheral blood. Preliminary results show a correlation between in vitro and in vivo data. The test can be repeated throughout the course of the disease to help identify any change in tumour sensitivity. This technique appears to give useful information to assist in the management of acute myeloid leukaemia.

Appraisal of the MTT assay as a rapid test of chemosensitivity in acute myeloid leukaemia.

The entomopathogenic fungus Neozygites parvispora (Entomophthorales: Zygomycetes) grows in vitro as irregularly rod-shaped hyphal bodies in a complex medium. In order to simplify the medium composition and determine growth-promoting compounds for the cultivation of this fungus, we were looking for a rapid and quantitative method to estimate the number of living cells in small volumes of liquid culture. A colorimetric method for the determination of cell densities using MTT [3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] proved to be more accurate and timesaving than conventional hemocytometer counting.

The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay is a fast and reliable method for colorimetric determination of fungal cell densities.

The amyloid precursor protein (APP) is a transmembrane protein expressed in several cell types. In the nervous system, APP is expressed by glial and neuronal cells, and several lines of evidence suggest that it plays a role in normal and pathological phenomena. To address the question of the actual function of APP in normal developing neurons, we undertook a study aimed at blocking APP expression using antisense oligonucleotides. Oligonucleotide internalization was achieved by linking them to a vector peptide that translocates through biological membranes. This original technique, which is very efficient and gives direct access to the cell cytosol and nucleus, allowed us to work with extracellular oligonucleotide concentrations between 40 and 200 nM. Internalization of antisense oligonucleotides overlapping the origin of translation resulted in a marked but transient decrease in APP neosynthesis that was not observed with the vector peptide alone, or with sense oligonucleotides. Although transient, the decrease in APP neosynthesis was sufficient to provoke a distinct decrease in axon and dendrite outgrowth by embryonic cortical neurons developing in vitro. The latter decrease was not accompanied by changes in the spreading of the cell bodies. A single exposure to coupled antisense oligonucleotides at the onset of the culture was sufficient to produce significant morphological effects 6, 18, and 24 h later, but by 42 h, there were no remaining significant morphologic changes. This report thus demonstrates that amyloid precursor protein plays an important function in the morphological differentiation of cortical neurons in primary culture.

/pdf/downregulation-of-amyloid-precursor-protein-inhibits-neurite-3e9hs4z4c0.pdf

Downregulation of Amyloid Precursor Protein Inhibits Neurite Outgrowth In Vitro

Tumor necrosis factor/cachectin (TNF/C) is the principal mediator of bacterial endotoxin-induced shock and death. We found that the C3H/HeJ mouse, which is less able to produce TNF/C in response to endotoxin, has a 1,000-fold greater susceptibility to lethal infection with Escherichia coli than the TNF-responsive congenic mouse, C3H/HeN. This surprising finding suggested that this lethal peptide may also be involved in host protection. To test this hypothesis we pretreated the C3H/HeJ mouse with a combination of recombinant murine TNF/C-alpha and IL-1 alpha. This combination protected these mice against an intraperitoneal bacterial challenge of greater than 20 LD50S (nearly 2 x 10(2) CFU) that grew to a level of greater than 10(7) CFU/ml of blood and per gram of liver in untreated mice. This suggests a significant role for these cytokines in host defenses against invasive infections that require bacterial replication within the host. These protective mechanisms may not be important for less virulent organisms. These findings may have important implications for the proposed use of anti-TNF/C agents in the treatment of septic shock.

https://rupress.org/jem/article-pdf/169/6/2021/1394474/2021.pdf

Pretreatment with recombinant murine tumor necrosis factor alpha/cachectin and murine interleukin 1 alpha protects mice from lethal bacterial infection.

B. Xue

Papers

Rapid colorimetric assay for cell growth and survival in application of immunotoxicology

Toxicity and detoxification of T-2 toxin in poultry.