Prediction of Human Acute Toxicity by the Hep G2/24-hour/Total Protein Assay, with Protein Measurement by the CBQCA Method

2005 ◽  
Vol 33 (3) ◽  
pp. 207-213 ◽  
Author(s):  
Paul J. Dierickx

In our previously described Hep G2/24-hour/total protein assay, protein levels were measured by using the Lowry method. This assay was the best acute in vitro assay for the prediction of human toxicity within the Multicentre Evaluation of In Vitro Cytotoxicity (MEIC) study. In order to increase the MEIC data-base with a wider range of chemicals, we were interested in introducing the more practical 3-(4-carboxybenzoyl)-quinoline-2-carboxaldehyde (CBQCA) method for the quantification of the total protein content. Therefore, we investigated whether the same good results for the prediction of acute human toxicity would be obtained with the CBQCA method. The cells were treated for 24 hours, then cytotoxicity was determined by measuring the total protein content with CBQCA. The results were quantified by using the PI50c: the concentration (in mM) of test compound required to reduce the total protein content measured with the CBQCA-method by 50% as compared to the control cells. The results were compared with the PI50, the corresponding value when the Lowry method was used. A relatively low correlation was observed between PI50 and PI50c, reflecting the large and unexpected, differences when using the two protein assays. However, when comparing the log PI50c with the human toxicity, a correlation coefficient of r2 = 0.761 ( n = 44) was obtained for exactly the same series of MEIC chemicals. This value is clearly higher than that for the Lowry method ( r2 = 0.695). Compared to the Lowry method originally used, the Hep G2/24-hour/CBQCA total protein assay has the additional important advantage that it can be very easily adapted for large-scale analyses with robotic systems, including the on-line calculation of the results.

2020 ◽  
Vol 987 ◽  
pp. 118-123
Author(s):  
Nurul Syafiqa Izyan ◽  
Dg Nurdayana Azman ◽  
Nur Amalina Mohd Saad ◽  
Suhaila Mohd Sauid ◽  
Fazlena Hamzah

The study was done to determine the effect of Tacca starch loading on production of amylolytic enzyme from Ragi Tapai. In this study, Ragi Tapai was used as a starter to produce amylolytic enzyme. The fermentation was done in a solid state fermentation with the presence of Tacca leontopetaloides starch as the carbon source. The analysis of total sugar was conducted using DNS method and amylolytic enzyme was determined using Lowry method. The mixture was fermented and incubated for 24, 48, 72 and 96h. The result revealed that the optimum production of amylase was found at 48 h of incubation with amylase activity of 1.91 U/ml/min and 1.42 mg/ml for total protein. The study shows that increment amount of the Tacca starch in cultivation medium, increase the production of the amylase and total protein content. The highest enzyme activity was obtained at 4% of Tacca starch loading with amylase activity and total protein content of 2.14 U/ml/min and 1.42 mg/ml respectively. The study indicated that growth promoters in Tacca starch capable to enhance the activity of microbial consortium in Ragi Tapai for production of the amylolytic enzyme.


1995 ◽  
Vol 198 (5) ◽  
pp. 1071-1077 ◽  
Author(s):  
T Gomi ◽  
T Okuda ◽  
S Tanaka

The development and degeneration of the flight muscles in adult crickets, Gryllus bimaculatus, were studied (1) by determination of the total protein content, (2) by SDS one-dimensional polyacrylamide gel electrophoresis (SDS­PAGE) of muscle protein and (3) by in vitro culturing of the muscle. The total protein content of the dorso-longitudinal muscle (DLM) and metathoracic dorso-ventral muscle (DVM) increased during the early days of adult life in both sexes. This high protein content was maintained for at least a further 10 days in some individuals, while in others it declined to a low level. Mesothoracic DVMs in males also showed an increase in protein content after adult emergence but did not undergo histolysis, whereas those in females showed no significant temporal change in protein content. Removal of hind wings or artificial de-alation was found to be useful in inducing degeneration of DLMs and metathoracic DVMs. This treatment also stimulated ovarian development in females. An analysis by SDS­PAGE provided no evidence for new protein synthesis prior to or during flight muscle degeneration. A high rate of [3H]- or [35S]methionine incorporation was observed in DLMs taken from newly emerged adults, but, in intact crickets, the rate declined rapidly during the first 3 days of adult life, a pattern consistent with that obtained from the measurement of total protein content. Compared with DLMs removed from intact crickets, DLMs taken from de-alated crickets showed reduced rates of protein synthesis during in vitro culturing. This, together with the onset of protein degradation, appears to cause the rapid decrease in total protein content of the muscle in de-alated crickets.


2011 ◽  
Vol 54 (6) ◽  
pp. 1135-1146 ◽  
Author(s):  
Rodrigo Netto Costa ◽  
Clarice Lima do Canto Abreu ◽  
Rosaura Farias Presgrave ◽  
Eloisa Nunes Alves ◽  
Octavio Augusto França Presgrave ◽  
...  

1996 ◽  
Vol 24 (5) ◽  
pp. 715-725
Author(s):  
Katarina Ruppová ◽  
Darina Slameñová ◽  
Ladislave Wsølová ◽  
Alena Gábelová ◽  
Maria Vargová

The cytotoxic effects of short-term and long-term exposure of HeLa cells to paracetamol (acetaminophen) were assayed by total protein content reduction (microprotein assay) and by [14C]-L-leucine incorporation into macromolecular acid-insoluble cell fraction. The level of total protein content was followed over 72 hours and the level of [14C]-L-leucine incorporation over 24 hours, after paracetamol treatment. Statistical evaluation did not show a significant difference between results obtained by these two methods. In addition, the influence of S9 fraction on [14C]-L-leucine incorporation and the growth activity of paracetamol-treated HeLa cells were assayed. In these experiments, short-term paracetamol treatments (2 hours in phosphate buffered saline), were used. Statistical analysis of the data did not show an increase in paracetamol-induced cytotoxicity in the presence of the S9 fraction; on the contrary, a protective effect of S9 fraction on paracetamol-treated cells was found.


2013 ◽  
Vol 24 (2) ◽  
pp. 128-135 ◽  
Author(s):  
Camila Bonvicino Pelegrini ◽  
Luciana Prado Maia ◽  
Sérgio Luís Scombatti de Souza ◽  
Mário Taba Jr ◽  
Daniela Bazan Palioto

As dogs are good models for in vivo studies, it is interesting to evaluate the behavior of canine gingival fibroblasts (CGF) in vitro, so that these cells could be seeded on a matrix and later studied in vivo. The aim of this study was to perform a morphological, functional and biochemical analysis of CGF, comparing it with human gingival fibroblasts (HGF), as well as to evaluate the change of their characteristics over several passages. Using gingival fibroblasts from 3 dogs and 3 humans in the subculture (Sub), first (P1), third (P3), fifth (P5) and seventh (P7) passages, the following parameters were assessed: cell morphology, spreading, adhesion, viability and total protein content. The results showed no major differences between the passages in terms of morphology and spreading, and a tendency of greater adhesion and viability for HGF when compared with CGF. The total protein content was significantly higher for HGF. HGF exhibited greater functional and biochemical activity in vitro compared to CGF. Higher numbers at Sub were observed for both CGF and HGF in all evaluated parameters. The differences do not prevent the use of CGF for tissue engineering, but its use seems to be more appropriate in the subculture or first passage.


1990 ◽  
Vol 17 (4) ◽  
pp. 401-406
Author(s):  
Isabella Mazziotti ◽  
Anna-Laura Stammati ◽  
Flavia Zucco

Twenty-six chemicals supplied coded by FRAME, were tested on HEp-2 cells. Three endpoints were used to measure the cytotoxicity of these compounds: total protein content, LDH release and total acid phosphatase content. The sensitivity of these parameters is discussed. The results are compared with those obtained by other groups participating in the validation scheme organised by FRAME.


Author(s):  
J.G. Thompson ◽  
A.N.M. Sherman ◽  
N.W. Allen ◽  
L.T. McGowan ◽  
H.R. Tervit

2002 ◽  
Vol 16 (3) ◽  
pp. 209-215 ◽  
Author(s):  
Adalberto Luiz Rosa ◽  
Márcio Mateus Beloti ◽  
Richard van Noort ◽  
Paul Vincent Hatton ◽  
Anne Jane Devlin

Hydroxyapatite (HA) has been used in orthopedic, dental, and maxillofacial surgery as a bone substitute. The aim of this investigation was to study the effect of surface topography produced by the presence of microporosity on cell response, evaluating: cell attachment, cell morphology, cell proliferation, total protein content, and alkaline phosphatase (ALP) activity. HA discs with different percentages of microporosity (< 5%, 15%, and 30%) were confected by means of the combination of uniaxial powder pressing and different sintering conditions. ROS17/2.8 cells were cultured on HA discs. For the evaluation of attachment, cells were cultured for two hours. Cell morphology was evaluated after seven days. After seven and fourteen days, cell proliferation, total protein content, and ALP activity were measured. Data were compared by means of ANOVA and Duncan’s multiple range test, when appropriate. Cell attachment (p = 0.11) and total protein content (p = 0.31) were not affected by surface topography. Proliferation after 7 and 14 days (p = 0.0007 and p = 0.003, respectively), and ALP activity (p = 0.0007) were both significantly decreased by the most irregular surface (HA30). These results suggest that initial cell events were not affected by surface topography, while surfaces with more regular topography, as those present in HA with 15% or less of microporosity, favored intermediary and final events such as cell proliferation and ALP activity.


1979 ◽  
Vol 236 (2) ◽  
pp. H268-H272 ◽  
Author(s):  
R. C. Hickson ◽  
G. T. Hammons ◽  
J. O. Holoszy

Adult female rats were exercised by daily swimming. All the increase in heart weight induced by the exercise occurred within 14 days and averaged 30%. The half times of the increases in heart weight and total protein content were about 4.5 days, whereas that of cytochrome c, which was used as a mitochondrial marker, was 6.5 days. The total amounts of DNA and of hydroxyproline in the heart, which were used to evaluate the degree of connective tissue hyperplasia, increased only slightly (8% and 10%, respectively). Other animals were subjected to the same swimming program for 21 days. Groups of rats were killed at various time intervals after stopping exercise. Heart weight, total protein content, and total cytochrome c content decreased rapidly initially, with 60% of the total regression of hypertrophy occurring during the first week. Thereafter, heart weight fell more gradually toward the sedentary control value. The hydroxyproline content of the heart, which was increased 10%, did not decrease during the regression of the hypertrophy.


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