Withdrawn: Comparative in vitro Studies on Isolated Smooth Muscles Contractions from Different Anatomical Sites of the Same Animal under Same Experimental Conditions

2015 ◽  
Vol 10 (2) ◽  
pp. 71-78
Author(s):  
Peter I. Aziba
Keyword(s):  
Smooth Muscles ◽  
In Vitro Studies ◽  
Experimental Conditions

scholarly journals Temozolomide sensitivity of malignant glioma cell lines – a systematic review assessing consistencies between in vitro studies

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Michael T. C. Poon ◽  
Morgan Bruce ◽  
Joanne E. Simpson ◽  
Cathal J. Hannan ◽  
Paul M. Brennan
Keyword(s):  
Cell Viability ◽  
Malignant Glioma ◽  
Cell Line ◽  
Cell Lines ◽  
Glioma Cell ◽  
Glioma Cell Line ◽  
In Vitro Studies ◽  
Experimental Conditions ◽  
Glioma Cell Lines

Abstract Background Malignant glioma cell line models are integral to pre-clinical testing of novel potential therapies. Accurate prediction of likely efficacy in the clinic requires that these models are reliable and consistent. We assessed this by examining the reporting of experimental conditions and sensitivity to temozolomide in glioma cells lines. Methods We searched Medline and Embase (Jan 1994-Jan 2021) for studies evaluating the effect of temozolomide monotherapy on cell viability of at least one malignant glioma cell line. Key data items included type of cell lines, temozolomide exposure duration in hours (hr), and cell viability measure (IC50). Results We included 212 studies from 2789 non-duplicate records that reported 248 distinct cell lines. The commonest cell line was U87 (60.4%). Only 10.4% studies used a patient-derived cell line. The proportion of studies not reporting each experimental condition ranged from 8.0–27.4%, including base medium (8.0%), serum supplementation (9.9%) and number of replicates (27.4%). In studies reporting IC50, the median value for U87 at 24 h, 48 h and 72 h was 123.9 μM (IQR 75.3–277.7 μM), 223.1 μM (IQR 92.0–590.1 μM) and 230.0 μM (IQR 34.1–650.0 μM), respectively. The median IC50 at 72 h for patient-derived cell lines was 220 μM (IQR 81.1–800.0 μM). Conclusion Temozolomide sensitivity reported in comparable studies was not consistent between or within malignant glioma cell lines. Drug discovery science performed on these models cannot reliably inform clinical translation. A consensus model of reporting can maximise reproducibility and consistency among in vitro studies.

scholarly journals IN VITRO STUDIES ON THE INTERACTION BETWEEN MOUSE PERITONEAL MACROPHAGES AND STRAINS OF SALMONELLA AND ESCHERICHIA COLI

1960 ◽  
Vol 112 (2) ◽  
pp. 403-417 ◽  
Author(s):  
Charles Jenkin ◽  
Baruj Benacerraf
Keyword(s):  
Escherichia Coli ◽  
Normal Mouse ◽  
Peritoneal Macrophages ◽  
In Vitro Studies ◽  
Experimental Conditions ◽  
Mouse Plasma ◽  
Virulent Strains ◽  
Mouse Macrophages ◽  
Mouse Peritoneal Macrophages

Virulent strains of Salmonella opsonized with normal mouse plasma are never phagocytosed as well as avirulent strains. The virulent strains of Salmonella phagocytosed after opsonization with normal mouse plasma are able to multiply within normal mouse peritoneal macrophages, whereas under similar experimental conditions the avirulent strains are killed. When virulent strains of Salmonella are opsonized with specific antiserum or plasma from BCG-infected mice, they are treated by normal mouse macrophages as if they were avirulent. Virulent bacteria opsonized with BCG plasma are phagocytosed and killed better by peritoneal macrophages from BCG-infected mice, than peritoneal macrophages from normal mice.

scholarly journals Time-dependent and force-dependent vasoreactivity of isolated human umbilical arteries

2020 ◽  
Vol 51 (3) ◽  
pp. 134-140
Author(s):  
Đorđe Đukanović ◽  
Milica Gajić ◽  
Ranko Škrbić
Keyword(s):  
Incubation Period ◽  
Cold Storage ◽  
Dose Response ◽  
In Vitro Studies ◽  
Time Dependent ◽  
Response Curves ◽  
Experimental Conditions ◽  
Umbilical Arteries ◽  
The Impact

Background/Aim: There have been different experimental conditions for in vitro studies on human umbilical arteries (HUA) in tissue bath system. This diversity was mainly reflected in variables such as stretching tension, incubation period and initial constriction challenging with potassium (KCl). The aim of the study was to establish optimal experimental conditions which will provide better responsiveness of HUA preparations, as well as to examine the impact of 24 h cold storage on viability and responsiveness of HUA to KCl and serotonin. Methods: The KCl-induced constrictions at different stretching tensions (0.5 g, 1.0 g, 2.0 g, 4.0 g), incubation times (30 min, 60 min, 120 min), and after multiple initial constriction challenging were compared. Dose response curves for serotonin were obtained under different conditions (1.0 g and 60 min vs. 2.0 g and 120 min). The influence of 24 h cold storage on KCland serotonininduced vasoconstriction of HUA preparations was examined as well. Results: The strongest constrictions induced by serotonin or KCl were obtained when preparations were adjusted at 2.0 g and incubated for 120 min. The KCl-induced constrictions observed after 120 min were statistically higher (p < 0.05) when preparations were challenged three times (30 min, 60 min, 120 min), compared to those challenged only once. The preparations that were stored at 4 ⁰C for 24 h showed significantly stronger serotonin-induced constrictions (p < 0.01). The cold storage had no influence on KCl-induced constriction. Conclusion: For performing in vitro studies on HUA preparations in tissue bath, we propose stretching tension of 2.0 g, incubation period of 120 min and multiple initial constriction challenging with KCl as optimal experimental condition. We also showed that HUA preparations retained functional viability even after 24 h of cold storage.

scholarly journals Temozolomide sensitivity of malignant glioma cell lines: a systematic review assessing consistencies between in vitro studies

2021 ◽  
Author(s):  
Michael TC Poon ◽  
Morgan Bruce ◽  
Joanne Simpson ◽  
Cathal J Hannan ◽  
Paul M Brennan
Keyword(s):  
Cell Viability ◽  
Malignant Glioma ◽  
Cell Line ◽  
Cell Lines ◽  
Glioma Cell ◽  
Glioma Cell Line ◽  
In Vitro Studies ◽  
Experimental Conditions ◽  
Glioma Cell Lines

Background: Malignant glioma cell line models are integral to pre-clinical testing of novel potential therapies. Accurate prediction of likely efficacy in the clinic requires that these models are reliable and consistent. We assessed this by examining the reporting of experimental conditions and sensitivity to temozolomide in glioma cells lines. Methods: We searched Medline and Embase (Jan 1994-Jan 2021) for studies that evaluated the effect of temozolomide monotherapy on cell viability of at least one malignant glioma cell line. Studies using a drug-resistant cell line or a modified preparation of temozolomide were excluded. Key data items included type of cell lines, temozolomide exposure duration, and cell viability measure (IC50). Results: We included 212 eligible studies from 2,789 non-duplicate records that reported 248 distinct cell lines. The commonest cell line was U87 (60.4%). Only 10.4% studies used a patient-derived cell line. The proportion of studies not reporting each experimental condition ranged from 8.0-27.4%, including base medium (8.0%), serum supplementation (9.9%) and number of replicates (27.4%). In studies reporting IC50 the median value for U87 cell line at 24 hours, 48 hours and 72 hours was 123.9μM (IQR 75.3-277.7μM), 223.1μM (IQR 92.0-590.1μM) and 230.0μM (IQR 34.1-650.0μM), respectively (Figure 2A). The median IC50 at 72 hours for patient-derived cell lines was 220μM (IQR 81.1-800.0μM). Conclusions: Temozolomide sensitivity reported in comparable studies was not consistent between and within individual malignant glioma cell lines. Drug discovery science performed on these models cannot reliably inform clinical translation. A consensus model of reporting can maximise reproducibility and consistency among in vitro studies.

An Analysis of the Postgastrula Differentiation of the Hypomere

Development ◽  
1961 ◽  
Vol 9 (4) ◽  
pp. 609-617
Author(s):  
Cyril V. Finnegan
Keyword(s):  
In Vitro Studies ◽  
Experimental Conditions ◽  
Initial Report ◽  
Taricha Torosa

The initial report in this series (Finnegan, 1961) emphasized the role of the endoderm in the postgastrula differentiation of the hypomeric mesoderm in Ambystoma punctatum. The effect of the endoderm appeared to be modified when the mass of mesoderm involved was increased and, under the in vitro experimental conditions employed, the endoderm did not influence the splanchnic layer of the hypomere into new types of histogenesis (induction). Thus it was concluded that the endoderm aided the histogenesis of the splanchnic mesoderm in its vicinity in a synergistic manner rather than as an inductive tissue. Further evidence of the mechanism of this assistance by the endoderm of the postgastrula development of the mesoderm has been obtained from similar in vitro studies with tissues from Taricha torosa neurulae. This report is concerned with results which substantiate the previously derived conclusions and, further, indicate at least one manner in which the endoderm effects its synergistic role.

scholarly journals Molecular Mechanisms of Mitotane Action in Adrenocortical Cancer Based on In Vitro Studies

Cancers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 5255
Author(s):  
Marco Lo Iacono ◽  
Soraya Puglisi ◽  
Paola Perotti ◽  
Laura Saba ◽  
Jessica Petiti ◽  
...  
Keyword(s):  
Cell Lines ◽  
Mechanism Of Action ◽  
Molecular Mechanisms ◽  
Cytochromes P450 ◽  
Culture Conditions ◽  
In Vitro Studies ◽  
Adrenocortical Cancer ◽  
Experimental Conditions ◽  
Cell Strains

Mitotane is the only approved drug for the treatment of advanced adrenocortical carcinoma and is increasingly used for postoperative adjuvant therapy. Mitotane action involves the deregulation of cytochromes P450 enzymes, depolarization of mitochondrial membranes, and accumulation of free cholesterol, leading to cell death. Although it is known that mitotane destroys the adrenal cortex and impairs steroidogenesis, its exact mechanism of action is still unclear. The most used cell models are H295-derived cell strains and SW13 cell lines. The diverging results obtained in presumably identical cell lines highlight the need for a stable in vitro model and/or a standard methodology to perform experiments on H295 strains. The presence of several enzymatic targets responsive to mitotane in mitochondria and mitochondria-associated membranes causes progressive alteration in mitochondrial structure when cells were exposed to mitotane. Confounding factors of culture affecting in vitro experiments could reduce the significance of any molecular mechanism identified in vitro. To ensure experimental reproducibility, particular care should be taken in the choice of culture conditions: aspects such as cell strains, culture serum, lipoproteins concentration, and culture passages should be carefully considered and explicated in the presentation of results. We aimed to review in vitro studies on mitotane effects, highlighting how different experimental conditions might contribute to the controversial findings. If the concerns pointed out in this review will be overcome, the new insights into mitotane mechanism of action observed in-vitro could allow the identification of novel pharmacological molecular pathways to be used to implement personalized therapy.

In Vitro Studies of the Phenomenon of Tetracycline Incorporation into Enamel

1977 ◽  
Vol 56 (12) ◽  
pp. 1527-1532 ◽  
Author(s):  
D.B. Lambrou ◽  
B.S. Tahos ◽  
K.D. Lambrou
Keyword(s):  
Dental Enamel ◽  
In Vitro Studies ◽  
Experimental Conditions

Incorporation of tetracycline into dental enamel was studied by exposing presoftened enamel slabs to tetracycline-containing mineralizing solutions. Tetracycline was incorporated only when remineralization (assessed by hardness) occurred and the experimental conditions favored the formation of a soluble tetracycline-Ca complex. The fluorescence induced by tetracycline incorporation into the enamel slabs was comparable to that reported under in vivo conditions.

Humoral induction of pyloric rhythmic output in lobster stomatogastric ganglion: in vivo and in vitro studies

1992 ◽  
Vol 163 (1) ◽  
pp. 209-230
Author(s):  
E. Rezer ◽  
M. Moulins
Keyword(s):  
Blood Serum ◽  
Stomatogastric Ganglion ◽  
In Vitro Studies ◽  
In Vitro Experiments ◽  
Experimental Conditions ◽  
Pyloric Network ◽  
Pyloric Rhythm

In the lobster Jasus lalandii, 14 neurones of the stomatogastric ganglion (STG) are organized in a network that produces rhythmic pyloric outputs. In vitro experiments have shown that the STG neurones receive, via the stomatogastric nerve (stn), neuromodulatory inputs that influence the expression of the bursting properties of the neurones and the ability of the network to produce its rhythmic output. In contrast to these in vitro observations, in vivo transection of the stn does not abolish the pyloric rhythm. Rhythmic output can be recorded by electromyography immediately after stn transection and for up to 2 years afterwards. We have shown that, under these experimental conditions, the STG appears to be isolated from any neuronal input that might account for the maintenance of the rhythmic output. Experiments carried out in the 2 days after stn transection showed that an in vitro preparation of the isolated STG was unable to produce any rhythmic output, but blood serum added to the system could restore the pyloric output. These results suggest strongly that the pyloric network receives neural and humoral modulatory influences in parallel and that each type of influence alone is able to maintain the bursting capability of the pyloric neurones.

Observations of Frozen-Hydrated Microtubules

1990 ◽  
Vol 48 (1) ◽  
pp. 504-505
Author(s):  
D. Chrétien ◽  
D. Job ◽  
R.H. Wade
Keyword(s):  
Fourier Transforms ◽  
Structural Complexity ◽  
Image Contrast ◽  
Phase Behaviour ◽  
Experimental Conditions ◽  
Thin Sections ◽  
Surface Lattice ◽  
Cilia And Flagella ◽  
Outstanding Question

Microtubules are filamentary structures found in the cytoplasm of eukaryotic cells, where, together with actin and intermediate filaments, they form the components of the cytoskeleton. They have many functions and show various levels of structural complexity as witnessed by the singlet, doublet and triplet structures involved in the architecture of centrioles, basal bodies, cilia and flagella. The accepted microtubule model consists of a 25 nm diameter hollow tube with a wall made up of 13 paraxial protofilaments (pf). Each pf is a string of aligned tubulin dimers. Some results have suggested that the pfs follow a superhelix. To understand how microtubules function in the cell an accurate model of the surface lattice is one of the requirements. For example the 9x2 architecture of the axoneme will depend on the organisation of its component microtubules. We should also note that microtubules with different numbers of pfs have been observed in thin sections of cellular and of in-vitro material. An outstanding question is how does the surface lattice adjust to these different pf numbers?We have been using cryo-electron microscopy of frozen-hydrated samples to study in-vitro assembled microtubules. The experimental conditions are described in detail in this reference. The results obtained in conjunction with thin sections of similar specimens and with axoneme outer doublet fragments have already allowed us to characterise the image contrast of 13, 14 and 15 pf microtubules on the basis of the measured image widths, of the the image contrast symmetry and of the amplitude and phase behaviour along the equator in the computed Fourier transforms. The contrast variations along individual microtubule images can be interpreted in terms of the geometry of the microtubule surface lattice. We can extend these results and make some reasonable predictions about the probable surface lattices in the case of other pf numbers, see Table 1. Figure 1 shows observed images with which these predictions can be compared.

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