scholarly journals Culture Medium Geometry: The Dominant Factor Affecting In Vitro RF Exposure Dosimetry

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Alessandra Paffi ◽  
Francesca Apollonio ◽  
Micaela Liberti ◽  
Asher Sheppard ◽  
Giorgi Bit-Babik ◽  
...  

Biological experiments that expose living cells or tissues to RF energy must have an aqueous medium to provide essential water, ions, nutrients, and growth factors. However, as we show here, the medium inherently functions as a receiving antenna that conveys RF energy to the biological entity in a manner entirely determined by exposure vessel geometry, orientation to the incident RF flux, frequency, and dielectric properties of the medium. We show for two common experimental arrangements that basic antenna theory can predict electromagnetic energy patterns that agree well with those otherwise obtained by computationally intensive methods that require specialized resources.

1993 ◽  
Vol 294 (3) ◽  
pp. 885-891 ◽  
Author(s):  
A Nègre-Salvayre ◽  
A Dagan ◽  
S Gatt ◽  
R Salvayre

Pyrenemethyl laurate (PMLes), a fluorogenic substrate for determining in vitro lipase activity [Nègre, Salvayre, Dagan and Gatt (1989) Biochim. Biophys. Acta 1006, 84-88], has been administered to cultured lymphoblastoid cells from normal subjects and from a patient affected with Wolman disease, which is characterized by a deficiency of lysosomal acid lipase. The intracellular degradation of PMLes was dependent on the mode of administration of the substrate into the cells, and occurred by two separate pathways involving lysosomal and extra-lysosomal hydrolases. PMLes incorporated into LDL was taken up by normal lymphoblastoid cells through the apolipoprotein-B/E-receptor-mediated pathway and degraded in the lysosomal compartment, as suggested by the degradation block in Wolman cells. In contrast, when PMLes dissolved in 2% dimethyl sulphoxide was added directly to the culture medium, its hydrolysis was similar in lymphoblastoid cells from controls and from patients affected with Wolman disease, neutral lipid storage disease or familial hypercholesterolaemia. This suggested that the administered PMLes was degraded by a non-lysosomal enzyme which is not deficient in Wolman cells. This enzyme also differs from the neutral lipase system which is deficient in lymphoblastoid cells from patients with neutral lipid storage disease. When pyrenemethanol was administered directly to the cell culture, it was only poorly acylated and was rapidly released into the culture medium. These results and the fluorescence properties of PMLes (‘monomeric’ emission in a hydrophobic environment and ‘excimeric’ emission in a hydrophilic environment) and pyrenemethanol (‘monomeric’ emission in a hydrophilic environment) allowed us to design a ‘direct reading’ procedure by monitoring (without any lipid extraction) the fluorescence of intact living cells and that of the culture medium during pulse-chase experiments. This method allowed the direct evaluation of the time course of in situ degradation of PMLes. In pulse-chase experiments with LDL-PMLes, the fluorescence of normal cells decreased relatively rapidly with time whereas the fluorescence of the culture medium increased concomitantly. With Wolman cells, the cellular fluorescence decreased only very slightly, whereas that of the culture medium remained at the basal level; this demonstrates the catabolic block in intact living cells from patients with Wolman disease. In vitro degradation of PMLes indicated the existence of two PMLes-degrading enzymes in lymphoblastoid cell homogenates: one is the acid lipase which is involved in PMLes degradation in the lysosomal compartment (and is deficient in Wolman cells), while the second is a cytoplasmic enzyme (not deficient in Wolman cells).


1991 ◽  
Vol 125 (3) ◽  
pp. 280-285 ◽  
Author(s):  
J. Alan Talbot ◽  
Ann Lambert ◽  
Robert Mitchell ◽  
Marek Grabinski ◽  
David C. Anderson ◽  
...  

Abstract We have investigated the role of Ca2+ in the control of FSH-induced estradiol secretion by Sertoli cells isolated from 8-10 days old rats. Exogenous Ca2+ (4-8 mmol/1) inhibited FSH-stimulated E2 secretion such that, with 8 mmol/l Ca2+ and FSH (8 IU/l) E2 secretion decreased from 2091±322 to 1480±84 pmol/l (p<0.002), whilst chelation of Ca2+ in the culture medium with EGTA (3 mmol/l) increased E2 secretion from 360±45 to 1242±133 pmol/l) in the absence of FSH. Further, EGTA (3 mmol/l) markedly potentiated FSH (8 IU/l), forskolin (1 μmol/l) and dibutyryl cAMP (1 mmol/l)-stimulated E2 secretion. Addition of the Ca2+ ionophores, ionomycin (2-5 μmol/l) and A23187 (2 μmol/l), inhibited FSH (8 IU/l)-stimulated E2 secretion by >80%. The effect of ionomycin was totally reversible, whereas that of A23187 was irreversible. Ionomycin (5 μmol/l) had no effect on EGTA-induced E2 secretion in the absence of FSH, but reduced EGTA-provoked E2 secretion by 59% in the presence of FSH (8 IU/l). Similarly, forskolin- and dibutyryl cAMP-provoked E2 production was inhibited 46-50% by ionomycin (5 μmol/l). We conclude that FSH-induced E2 secretion from immature rat Sertoli cells is modulated by intra- and extracellular Ca2+.


Reproduction ◽  
2000 ◽  
pp. 391-396 ◽  
Author(s):  
AH Duittoz ◽  
M Batailler

The aim of this study was to investigate the development of pulsatile GnRH secretion by GnRH neurones in primary cultures of olfactory placodes from ovine embryos. Culture medium was collected every 10 min for 8 h to detect pulsatile secretion. In the first experiment, pulsatile secretion was studied in two different sets of cultures after 17 and 24 days in vitro. In the second experiment, a set of cultures was tested after 10, 17 and 24 days in vitro to investigate the development of pulsatile GnRH secretion in each individual culture. This study demonstrated that (i) primary cultures of GnRH neurones from olfactory explants secreted GnRH in a pulsatile manner and that the frequency and mean interpulse duration were similar to those reported in castrated ewes, and (ii) pulsatile secretion was not present at the beginning of the culture but was observed between 17 and 24 days in vitro, indicating the maturation of individual neurones and the development of their synchronization.


Author(s):  
С.В. Калиш ◽  
С.В. Лямина ◽  
А.А. Раецкая ◽  
И.Ю. Малышев

Цель исследования. Репрограммирование М1 фенотипа макрофагов с ингибированными факторами транскрипции М2 фенотипа STAT3, STAТ6 и SMAD и оценка их влияния на развитие карциномы Эрлиха (КЭ) in vitro и in vivo. Методика. Рост опухоли иницировали in vitro путем добавления клеток КЭ в среду культивирования RPMI-1640 и in vivo путем внутрибрюшинной инъекции клеток КЭ мышам. Результаты. Установлено, что M1макрофаги и in vitro, и in vivo оказывают выраженный противоопухолевый эффект, который превосходит антиопухолевые эффекты М1, M1, M1 макрофагов и цисплатина. Заключение. М1 макрофаги с ингибированными STAT3, STAT6 и/или SMAD3 эффективно ограничивают рост опухоли. Полученные данные обосновывают разработку новой технологии противоопухолевой клеточной терапии. Objective. Reprogramming of M1 macrophage phenotype with inhibited M2 phenotype transcription factors, such as STAT3, STAT6 and SMAD and assess their impact on the development of Ehrlich carcinoma (EC) in vitro and in vivo . Methods. Tumor growth in vitro was initiated by addition of EC cells in RPMI-1640 culture medium and in vivo by intraperitoneal of EC cell injection into mice. Results. It was found that M1 macrophages have a pronounced anti-tumor effect in vitro , and in vivo , which was greater than anti-tumor effects of M1, M1, M1 macrophages and cisplatin. Conclusion. M1 macrophages with inhibited STAT3, STAT6 and/or SMAD3 effectively restrict tumor growth. The findings justify the development of new anti-tumor cell therapy technology.


Agrologia ◽  
2018 ◽  
Vol 1 (1) ◽  
Author(s):  
S. Tuhuteru ◽  
Meity L Hehanussa ◽  
Simon H.T Raharjo

Dendrobium anosmum is one of natural orchids in Indonesia. Optimization of medium composition for orchid propagation through in vitro culture is necessary to enhance propagule multiplication capabilities and quality. This study was aimed to study the influence of concentration of coconut water in culture medium on in vitro growth and development of D. anosmum orchid species and to determine the optimal coconut water concentration in culture media.  The experiment were arranged in a Completely Randomized Design with four treatments and eight replications. The treatments consisted of the addition of coconut water with concentrations: 0 ml•l -1 (control), 50 ml•l-1, 100 ml•l-1 and 150 ml•l-1. The results showed that addition of coconut water in culture medium gave different effect on shoot growth and multiplication of D. anosmum orchids.  Coconut water concentration of 100 ml•l-1 was the best concentration for growth and multiplication of D. anosmum orchids, based on both shoots and roots growth, plantlet height and wet weight.


Author(s):  
Bruna O. S. Câmara ◽  
Bruno M. Bertassoli ◽  
Natália M. Ocarino ◽  
Rogéria Serakides

The use of stem cells in cell therapies has shown promising results in the treatment of several diseases, including diabetes mellitus, in both humans and animals. Mesenchymal stem cells (MSCs) can be isolated from various locations, including bone marrow, adipose tissues, synovia, muscles, dental pulp, umbilical cords, and the placenta. In vitro, by manipulating the composition of the culture medium or transfection, MSCs can differentiate into several cell lineages, including insulin-producing cells (IPCs). Unlike osteogenic, chondrogenic, and adipogenic differentiation, for which the culture medium and time are similar between studies, studies involving the induction of MSC differentiation in IPCs differ greatly. This divergence is usually evident in relation to the differentiation technique used, the composition of the culture medium, the cultivation time, which can vary from a few hours to several months, and the number of steps to complete differentiation. However, although there is no “gold standard” differentiation medium composition, most prominent studies mention the use of nicotinamide, exedin-4, ß-mercaptoethanol, fibroblast growth factor b (FGFb), and glucose in the culture medium to promote the differentiation of MSCs into IPCs. Therefore, the purpose of this review is to investigate the stages of MSC differentiation into IPCs both in vivo and in vitro, as well as address differentiation techniques and molecular actions and mechanisms by which some substances, such as nicotinamide, exedin-4, ßmercaptoethanol, FGFb, and glucose, participate in the differentiation process.


1971 ◽  
Vol 24 ◽  
Author(s):  
W. H. Verstraete

Some  factors affecting the L-asparaginase activity of E.  aroideae were investigated. Increasing  concentrations of glucose in the culture medium had an inhibiting effect on  the production of L-asparaginase by this microorganism. Buffering of the  culture medium in order to stabilize the pH during growth resulted in a decrease  of the L-asparaginase activity. From the different nitrogen sources examined,  tryptone, proteose peptone nr 2 and nr 3 stimulated the L-asparaginase  production. Toluene treatment of the cells practically destroyed the  L-asparaginase. Acetone dried cells showed an L-asparaginase activity  comparable with the activity of living cells.


2021 ◽  
Author(s):  
Lijuan Liu ◽  
Shengting Zhang ◽  
Xiaodan Zheng ◽  
Hongmei Li ◽  
Qi Chen ◽  
...  

Fusobacterium nucleatum has been employed for the first time to synthesize fluorescent carbon dots which could be applied for the determination of Fe3+ ions in living cells and bioimaging in vitro and in vivo with excellent biocompatibility.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Ved ◽  
F. Sharouf ◽  
B. Harari ◽  
M. Muzaffar ◽  
S. Manivannan ◽  
...  

AbstractTraumatic brain injury (TBI) is associated with poor clinical outcomes; autopsy studies of TBI victims demonstrate significant oligodendrocyte progenitor cell (OPC) death post TBI; an observation, which may explain the lack of meaningful repair of injured axons. Whilst high-mobility group box-1 (HMGB1) and its key receptors TLR2/4 are identified as key initiators of neuroinflammation post-TBI, they have been identified as attractive targets for development of novel therapeutic approaches to improve post-TBI clinical outcomes. In this report we establish unequivocal evidence that HMGB1 released in vitro impairs OPC response to mechanical injury; an effect that is pharmacologically reversible. We show that needle scratch injury hyper-acutely induced microglial HMGB1 nucleus-to-cytoplasm translocation and subsequent release into culture medium. Application of injury-conditioned media resulted in significant decreases in OPC number through anti-proliferative effects. This effect was reversed by co-treatment with the TLR2/4 receptor antagonist BoxA. Furthermore, whilst injury conditioned medium drove OPCs towards an activated reactive morphology, this was also abolished after BoxA co-treatment. We conclude that HMGB1, through TLR2/4 dependant mechanisms, may be detrimental to OPC proliferation following injury in vitro, negatively affecting the potential for restoring a mature oligodendrocyte population, and subsequent axonal remyelination. Further study is required to assess how HMGB1-TLR signalling influences OPC maturation and myelination capacity.


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