scholarly journals Optimal Halbach Configuration for Flow-through Immunomagnetic CTC Enrichment

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1020
Author(s):  
Michiel Stevens ◽  
Peng Liu ◽  
Tom Niessink ◽  
Anouk Mentink ◽  
Leon Abelmann ◽  
...  
Keyword(s):  
Cell Lines ◽  
Low Frequency ◽  
Antigen Expression ◽  
Element Size ◽  
Halbach Array ◽  
Immunomagnetic Enrichment ◽  
Flow Through ◽  
Flow Configurations ◽  
Magnetophoretic Separation ◽  
Enrichment Process

Due to the low frequency of circulating tumor cells (CTC), the standard CellSearch method of enumeration and isolation using a single tube of blood is insufficient to measure treatment effects consistently, or to steer personalized therapy. Using diagnostic leukapheresis this sample size can be increased; however, this also calls for a suitable new method to process larger sample inputs. In order to achieve this, we have optimized the immunomagnetic enrichment process using a flow-through magnetophoretic system. An overview of the major forces involved in magnetophoretic separation is provided and the model used for optimizing the magnetic configuration in flow through immunomagnetic enrichment is presented. The optimal Halbach array element size was calculated and both optimal and non-optimal arrays were built and tested using anti-EpCAM ferrofluid in combination with cell lines of varying EpCAM antigen expression. Experimentally measured distributions of the magnetic moment of the cell lines used for comparison were combined with predicted recoveries and fit to the experimental data. Resulting predictions agree with measured data within measurement uncertainty. The presented method can be used not only to optimize magnetophoretic separation using a variety of flow configurations but could also be adapted to optimize other (static) magnetic separation techniques.

H-2 class I antigen expression on mouse teratocarcinoma cell lines

1985 ◽  
Vol 22 (6) ◽  
pp. 543-552 ◽  
Author(s):  
P. D�mant ◽  
M. Oudshoorn-Snoek
Keyword(s):  
Cell Lines ◽  
Antigen Expression ◽  
Class I ◽  
Teratocarcinoma Cell ◽  
Mouse Teratocarcinoma

scholarly journals The Influence of the Extremely Low Frequency Electromagnetic Field on Clear Cell Renal Carcinoma

2021 ◽  
Vol 22 (3) ◽  
pp. 1342
Author(s):  
Aleksandra Cios ◽  
Martyna Ciepielak ◽  
Wanda Stankiewicz ◽  
Łukasz Szymański
Keyword(s):  
Electromagnetic Field ◽  
Cancer Cells ◽  
Cell Lines ◽  
Renal Carcinoma ◽  
Clear Cell ◽  
Low Frequency ◽  
Inhibitory Effect ◽  
Hek293 Cells ◽  
Clear Cell Renal Carcinoma ◽  
Cell Renal Carcinoma

The development of new technologies and industry is conducive to the increase in the number and variety of electromagnetic field (EMF) sources in our environment. The main sources of EMF are high-voltage lines, household appliances, audio/video devices, mobile phones, radio stations, and radar devices. In the growing use of electronic devices, scientists are increasingly interested in the effects of EMF on human health. Even though many studies on the effects of EMF have already been carried out, none of them has shown a significant effect on mammals, including humans. Moreover, it is not entirely clear how EMF influences cell behavior. The International Agency for Research on Cancer on 31 May 2011, classified PEM as a possible carcinogenic factor. This study aimed to investigate the effect of the electromagnetic field on morphological and functional changes in clear cell renal carcinoma. The research was carried out on in vitro cultures of four cell lines: HEK293, 786-O 769-P, and Caki1. The results of the research showed that the EMF of low frequency had a slight effect on the viability of cells. EMF, which induced cell arrest in the G1 phase, increased the number of early apoptotic cells and decreased the number of viable cells in the 786-O line. EMF did not affect the proliferation and viability of HEK293 cells. Extreme low-frequency EMF (ELF-EMF) also showed an inhibitory effect on the migration and metastatic properties of clear cell kidney cancer cells. Moreover, shortly after the end of ELF-EMF exposure, significant increases in ROS levels were observed in all tested cell lines. As part of the work, it was shown that low-frequency EMF shows an inhibitory effect on the proliferation of primary cancer cells, diminishing their migratory, invasive, and metastatic abilities. It also increases the apoptosis of cancer cells and the amount of reactive oxygen species. Based on the results of our research, we want to point up that the effect of ELF-EMF depends on a specific metabolic state or at a specific stage in the cell cycle of the cells under study.

The Ets-related transcription factor PU.1 immortalizes erythroblasts

1993 ◽  
Vol 13 (9) ◽  
pp. 5670-5678
Author(s):  
S Schuetze ◽  
P E Stenberg ◽  
D Kabat
Keyword(s):  
Bone Marrow ◽  
Transcription Factor ◽  
Cell Lines ◽  
Cultured Cells ◽  
Low Frequency ◽  
In Vivo Studies ◽  
Bone Marrow Cultures ◽  
Clonal Cell Lines ◽  
Related Transcription Factor

In vivo studies of Friend virus erythroleukemia have implied that proviral integrations adjacent to the gene for the Ets-related transcription factor PU.1 may inhibit the commitment of erythroblasts to differentiate and cause their capability for indefinite transplantation (C. Spiro, B. Gliniak, and D. Kabat, J. Virol. 62:4129-4135, 1988; R. Paul, S. Schuetze, S. L. Kozak, C. Kozak, and D. Kabat, J. Virol. 65:464-467, 1991). To test this hypothesis, we ligated PU.1 cDNA into a retroviral vector and studied its effects on cultured cells. Infection of fibroblasts with PU.1-encoding retrovirus resulted in PU.1 synthesis followed by nuclear pyknosis, cell rounding, and degeneration. In contrast, in long-term bone marrow cultures, erythroblasts were efficiently and rapidly immortalized. The resulting cell lines were polyclonal populations that contained PU.1, were morphologically blast-like, required erythropoietin and bone marrow stromal cells for survival and proliferation, and spontaneously differentiated at low frequency to synthesize hemoglobin. After 9 months in culture, erythroblasts became stroma independent, and they then grew as clonal cell lines. We conclude that PU.1 perturbs the pathway(s) that controls potential for indefinite proliferation and that it can be used to generate permanent erythroblast cell lines.

Mutation at autosomal loci of Chinese hamster ovary cells: involvement of a high-frequency event silencing two linked alleles

1983 ◽  
Vol 3 (7) ◽  
pp. 1172-1181
Author(s):  
W E Bradley
Keyword(s):  
Cell Lines ◽  
Chinese Hamster Ovary ◽  
High Frequency ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Low Frequency ◽  
Class Ii ◽  
Class I ◽  
Wild Type ◽  
Ovary Cells

Two classes of cell lines heterozygous at the galactokinase (glk) locus have been isolated from Chinese hamster ovary cells. Class I, selected by plating nonmutagenized wild-type cells at low density in medium containing 2-deoxygalactose at a partially selective concentration, underwent subsequent mutation to the glk-/- genotype at a low frequency (approximately 10(-6) per cell), which was increased by mutagenesis. Class II heterozygotes, isolated by sib selection from mutagenized wild-type cells, had a higher spontaneous frequency of mutation to the homozygous state (approximately 10(-4) per cell), which was not affected by mutagenesis. About half of the glk-/- mutants derived from a class II heterozygote, but not the heterozygote itself, were functionally hemizygous at the syntenic thymidine kinase (tk) locus. Similarly, a tk+/- heterozygote with characteristics analogous to the class II glk+/- cell lines underwent high-frequency mutation to tk-/-, and most of these mutants, but not the tk+/- heterozygote, were functionally hemizygous at the glk locus. A model is proposed, similar to that for the mutational events at the adenine phosphoribosyl transferase locus (W. E. C. Bradley and D. Letovanec, Somatic Cell Genet. 8:51-66, 1982), of two different events, high and low frequency, being responsible for mutation at either of the linked loci tk and glk. The low-frequency event may be a point mutation, but the high-frequency event, in many instances, involves coordinated inactivation of a portion of a chromosome carrying the two linked alleles. Class II heterozygotes would be generated as a result of a low-frequency event at one allele, and class I heterozygotes would be generated by a high-frequency event. Supporting this model was the demonstration that all class I glk+/- lines examined were functionally hemizygous at tk.

scholarly journals Electrically stimulated acupuncture increases renal blood flow through exosome-carried miR-181

2018 ◽  
Vol 315 (6) ◽  
pp. F1542-F1549 ◽  
Author(s):  
Janet D. Klein ◽  
Xiaonan H. Wang
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Culture Medium ◽  
Gastrocnemius Muscle ◽  
Muscle Wasting ◽  
Muscle Protein ◽  
Low Frequency ◽  
Luciferase Reporter ◽  
Mouse Serum ◽  
Flow Through

Acupuncture with low-frequency electrical stimulation (Acu/LFES) can prevent muscle atrophy by increasing muscle protein anabolism in mouse models of chronic kidney disease. During the treatment of muscle wasting, we found that Acu/LFES on the gastrocnemius muscle of the leg enhances renal blood flow. We also found that Acu/LFES increases exosome abundance and alters exosome-associated microRNA expression in the circulation. When exosome secretion was blocked using GW4869, the Acu/LFES-induced increase in renal blood flow was limited. This provided evidence that the increased renal blood flow is exosome mediated. To identify how exosomes regulate renal blood flow, we performed microRNA deep sequencing in exosomes isolated from treated and untreated mouse serum and found that the 34 microRNAs are altered by Acu/LFES. In particular, miR-181d-5p is increased in the serum exosome of Acu/LFES-treated mice. In silico searching suggested that miR-181d-5p could target angiotensinogen. Using a luciferase reporter assay, we demonstrated that miR-181 directly inhibits angiotensinogen. When Acu/LFES-treated muscle was excised and incubated in culture medium, we found that the amount of exosomes and miR-181d-5p was increased in the medium providing evidence that Acu/LFES can increase miR-181 secretion. We conclude that Acu/LFES on leg hindlimb increases miR-181 in serum exosome leading to increased renal blood flow. This study provides important new insights about the mechanism(s) by which acupuncture may regulation of muscle-organ cross talk through exosome-derived microRNA.

Analysis of Magnetoelectric Conversion Performance of Low Frequency Halbach Array Energy Harvesting Structure

2021 ◽  
pp. 668-681
Author(s):  
Zhang Xiangyong ◽  
Liu Haipeng ◽  
Peng Tingrui ◽  
Su Bin ◽  
Guan Huiyuan
Keyword(s):  
Energy Harvesting ◽  
Low Frequency ◽  
Halbach Array ◽  
Conversion Performance

Latent Infection and Reactivation of Human Herpesvirus 6 in Two Novel Myeloid Cell Lines

Blood ◽  
1999 ◽  
Vol 93 (3) ◽  
pp. 991-999 ◽  
Author(s):  
Masaki Yasukawa ◽  
Hideki Ohminami ◽  
Eiji Sada ◽  
Yoshihiro Yakushijin ◽  
Masahiko Kaneko ◽  
...  
Keyword(s):  
Cell Lines ◽  
Philadelphia Chromosome ◽  
Human Herpesvirus ◽  
Myeloid Cell ◽  
Antigen Expression ◽  
Cell Lysis ◽  
Myelogenous Leukemia ◽  
Human Herpesvirus 6 ◽  
Latently Infected ◽  
Herpesvirus 6

Abstract It has been reported that reactivation of human herpesvirus-6 (HHV-6) causes a failure of hematopoiesis. To clarify the mechanisms of bone marrow suppression induced by HHV-6 infection, it is necessary to establish an in vitro model of HHV-6 infection in hematopoietic progenitor cells. We have established two novel Philadelphia chromosome–positive myeloid cell lines, SAS413 and SAS527, which possess different hematologic characteristics and show distinct susceptibility to infection by HHV-6, from a patient with blast crisis of chronic myelogenous leukemia (CML). HHV-6 subgroup A (HHV-6A) showed marked replication in SAS413, forming syncytia and inducing cell lysis in short-term culture. On the other hand, HHV-6A–inoculated SAS527 continued to proliferate without cell lysis and only a few cells showed HHV-6 antigen expression. In contrast to HHV-6A infection, inoculation with HHV-6 subgroup B (HHV-6B) did not induce any cytopathic effect (CPE) or viral antigen expression in either of the cell lines. Although HHV-6B replication was undetectable, the presence of the HHV-6 genome in both cell lines was shown by polymerase chain reaction (PCR) during culture for more than 10 months, suggesting that HHV-6B latently infected SAS413 and SAS527. Phorbol ester treatment of SAS527 latently infected with HHV-6B resulted in reactivation of HHV-6, as shown by the appearance of a CPE, positive reactivity for the HHV-6 antigen, and isolation of infectious HHV-6. These novel cell lines should be useful for studying the mechanisms of HHV-6–induced hematopoietic failure and HHV-6 latency and reactivation, as well as differentiation, of the myeloid cell lineage.

scholarly journals Siglec-15 recognition of sialoglycans on tumor cell lines can occur independently of sialyl Tn antigen expression

Glycobiology ◽  
2020 ◽  
Author(s):  
Gavuthami Murugesan ◽  
Viviana G Correia ◽  
Angelina S Palma ◽  
Wengang Chai ◽  
Chunxia Li ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Cell Lines ◽  
Antigen Expression ◽  
Mapk Signaling ◽  
Breast Cancer Cell Lines ◽  
Cross Linking ◽  
Monocytic Cell ◽  
Immunosuppressive Microenvironment ◽  
Sialyl Tn Antigen ◽  
Sialyl Tn

Abstract Siglec-15 is a conserved sialic acid-binding Ig-like lectin expressed on osteoclast progenitors, which plays an important role in osteoclast development and function. It is also expressed by tumor-associated macrophages and by some tumors, where it is thought to contribute to the immunosuppressive microenvironment. It was shown previously that engagement of macrophage-expressed Siglec-15 with tumor cells expressing its ligand, sialyl Tn (sTn), triggered production of TGF-β. In the present study, we have further investigated the interaction between Siglec-15 and sTn on tumor cells and its functional consequences. Based on binding assays with lung and breast cancer cell lines and glycan-modified cells, we failed to see evidence for recognition of sTn by Siglec-15. However, using a microarray of diverse, structurally defined glycans, we show that Siglec-15 binds with higher avidity to sialylated glycans other than sTn or related antigen sequences. In addition, we were unable to demonstrate enhanced TGF-β secretion following co-culture of Siglec-15-expressing monocytic cell lines with tumor cells expressing sTn or following Siglec-15 cross-linking with monoclonal antibodies. However, we did observe activation of the SYK/MAPK signaling pathway following antibody cross-linking of Siglec-15 that may modulate the functional activity of macrophages.

Fas/APO-1 (CD95)–Mediated Apoptosis Is Activated by Interferon-γ and Interferon- in Interleukin-6 (IL-6)–Dependent and IL-6–Independent Multiple Myeloma Cell Lines

Blood ◽  
1998 ◽  
Vol 92 (8) ◽  
pp. 2914-2923 ◽  
Author(s):  
Helena Spets ◽  
Patrik Georgii-Hemming ◽  
Jan Siljason ◽  
Kenneth Nilsson ◽  
Helena Jernberg-Wiklund
Keyword(s):  
Multiple Myeloma ◽  
Cell Lines ◽  
Poor Response ◽  
Antigen Expression ◽  
Myeloma Cell ◽  
Interferon Γ ◽  
Dependent Manner ◽  
Multiple Myeloma Cell ◽  
Ifn Γ ◽  
Induced Apoptosis

Abstract A poor response to Fas-induced apoptosis is evident in some multiple myeloma (MM) cell lines and primary cells. In this study, we have examined the possibility to increase the sensitivity to Fas-induced apoptosis by pretreatment of MM cells with interferon-γ (IFN-γ) or interferon- (IFN-). Both IFN-γ and IFN- markedly increased the Fas-induced apoptosis in all cell lines tested (U-266-1970, U-266-1984, and U-1958). In the U-266-1970 and U-1958 cell lines, pretreatment with either IFN-γ or IFN- also inhibited proliferation in a dose-dependent manner. In contrast, IFN-γ activation of the Fas death pathway in the U-266-1984 cells was not accompanied by growth inhibition. Incubation with the IFNs increased the Fas antigen expression in one of three cell lines but did not alter the expression of Bcl-2 or Bax. The IFNs are important regulators of growth and survival in MM cells. Our results suggest that activation of Fas-mediated apoptosis is a novel mechanism by which the IFNs exert inhibitory effects on MM cells. © 1998 by The American Society of Hematology.

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