scholarly journals EFEK GENOTOKSISITAS PADA BAHAN DENTAL ADHESIF

2021 ◽  
Vol 11 (2) ◽  
pp. 67
Author(s):  
Andi Izham ◽  
Elza Ibrahim Auerkari
Keyword(s):  
Tissue Repair ◽  
Morphological Changes ◽  
Biological Effects ◽  
Adhesive System ◽  
Dental Tissue ◽  
Adhesive Material ◽  
Dental Adhesive ◽  
Considerable Research ◽  
Adhesive Materials

The use of dental adhesive materials in dental practice everyday has raised questions about the biological effects on tissues. Adhesive system has attracted considerable research interest in recent years, dental adhesive will succeed depends on the chemical adhesive, on the appropriate clinical management of materials and the knowledge of morphological changes in dental tissue caused by different bonding procedures. Some studies suggest that the dental adhesive material Genotoxicity have any effect on the network. Genotoxic effects may significantly reduce the potential for tissue repair or cause the development of neoplasia in the long term.  

Adaptive hypersensitivity to estrogen: mechanism for superiority of aromatase inhibitors over selective estrogen receptor modulators for breast cancer treatment and prevention.

2003 ◽  
pp. 111-130 ◽  
Author(s):  
R J Santen ◽  
R X Song ◽  
Z Zhang ◽  
R Kumar ◽  
M-H Jeng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Estrogen Receptor ◽  
Cell Membrane ◽  
Map Kinase ◽  
Aromatase Inhibitors ◽  
Morphological Changes ◽  
Biological Effects ◽  
Genomic Effects

Clinical observations suggest that human breast tumors can adapt to endocrine therapy by developing hypersensitivity to estradiol (E(2)). To understand the mechanisms responsible, we examined estrogenic stimulation of cell proliferation in a model system and provided in vitro and in vivo evidence that long-term E(2) deprivation (LTED) causes "adaptive hypersensitivity". The enhanced responses to E(2) do not involve mechanisms acting at the level of transcription of estrogen-regulated genes. We found no evidence of hypersensitivity when examining the effects of E(2) on regulation of c-myc, pS2, progesterone receptor, several estrogen receptor (ER) reporter genes, or c-myb in hypersensitive cells. Estrogen deprivation of breast cells long-term does up-regulate both the MAP kinase and phosphatidyl-inositol 3-kinase pathways. As a potential explanation for up-regulation of these signaling pathways, we found that ERalpha is 4- to 10-fold up-regulated and co-opts a classic growth factor pathway using Shc, Grb-2 and Sos. This induces rapid non-genomic effects which are enhanced in LTED cells. E(2) binds to cell membrane-associated ERalpha, physically associates with the adapter protein SHC, and induces its phosphorylation. In turn, Shc binds Grb-2 and Sos, which results in the rapid activation of MAP kinase. These non-genomic effects of E(2) produce biological effects as evidenced by Elk activation and by morphological changes in cell membranes. Further proof of the non-genomic effects of E(2) involved use of cells which selectively expressed ERalpha in the nucleus, cytosol and cell membrane. We created these COS-1 "designer cells" by transfecting ERalpha lacking a nuclear localization signal and containing a membrane localizing signal. The concept of "adaptive hypersensitivity" and the mechanisms responsible for this phenomenon have important clinical implications. Adaptive hypersensitivity would explain the superiority of aromatase inhibitors over the selective ER modulators (SERMs) for treatment of breast cancer. The development of highly potent third-generation aromatase inhibitors allows reduction of breast tissue E2 to very low levels and circumvents the enhanced sensitivity of these cells to the proliferative effects of E(2). Clinical trials in the adjuvant, neoadjuvant and advanced disease settings demonstrate the greater clinical efficacy of the aromatase inhibitors over the SERMs. More recent observations indicate that the aromatase inhibitors are superior for the prevention of breast cancer as well. These observations may be explained by the hypothesis that estrogens induce breast cancer both by stimulating cell proliferation and by their metabolism to genotoxic products. The SERMs block ER-mediated proliferation only, whereas the aromatase inhibitors exert dual effects on proliferation and genotoxic metabolite formation.

Comparative assessment of morphological mechanisms of maintaining structural liver homeostasis in the dynamics of exposure to coal-rock dust and sodium fluoride on the body

2020 ◽  
pp. 189-194
Author(s):  
M. S. Bugaeva ◽  
O. I. Bondarev ◽  
N. N. Mikhailova ◽  
L. G. Gorokhova
Keyword(s):  
Sodium Fluoride ◽  
Morphological Changes ◽  
The Body ◽  
System Level ◽  
Production Factor ◽  
Coal Rock ◽  
The Impact ◽  
Structural Homeostasis ◽  
Rock Dust

Introduction. The impact on the body of such factors of the production environment as coal-rock dust and fluorine compounds leads to certain shift s in strict indicators of homeostasis at the system level. Maintaining the relative constancy of the internal environment of the body is provided by the functional consistency of all organs and systems, the leading of which is the liver. Organ repair plays a crucial role in restoring the structure of genetic material and maintaining normal cell viability. When this mechanism is damaged, the compensatory capabilities of the organ are disrupted, homeostasis is disrupted at the cellular and organizational levels, and the development of the main pathological processes is noted.The aim of the study is to compare the morphological mechanisms of maintaining structural homeostasis of the liver in the dynamics of the impact on the body of coal-rock dust and sodium fluoride.Materials and methods. Experimental studies were conducted on adult white male laboratory rats. Features of morphological mechanisms for maintaining structural homeostasis of the liver in the dynamics of exposure to coal-rock dust and sodium fluoride were studied on experimental models of pneumoconiosis and fluoride intoxication. For histological examination in experimental animals, liver sampling was performed after 1, 3, 6, 9, 12 weeks of the experiment.Results. The specificity of morphological changes in the liver depending on the harmful production factor was revealed. It is shown that chronic exposure to coal-rock dust and sodium fluoride is characterized by the development of similar morphological changes in the liver and its vessels from the predominance of the initial compensatory-adaptive to pronounced violations of the stromal and parenchymal components. Long-term inhalation of coal-rock dust at 1–3 weeks of seeding triggers adaptive mechanisms in the liver in the form of increased functional activity of cells, formation of double-core hepatocytes, activation of immunocompetent cells and endotheliocytes, ensuring the preservation of the parenchyma and the general morphostructure of the organ until the 12th week of the experiment. Exposure to sodium fluoride leads to early disruption of liver compensatory mechanisms and the development of dystrophic changes in the parenchyma with the formation of necrosis foci as early as the 6th week of the experiment.Conclusions. The study of mechanisms for compensating the liver structure in conditions of long-term exposure to coal-rock dust and sodium fluoride, as well as processes that indicate their failure, and the timing of their occurrence, is of theoretical and practical importance for developing recommendations for the timely prevention and correction of pathological conditions developing in employees of the aluminum and coal industry.The authors declare no conflict of interests.

The mechanistic role of thymoquinone in Parkinson's disease: focus on neuroprotection in pre-clinical studies

2021 ◽  
Vol 14 ◽  
Author(s):  
Mohammad Najim Uddin ◽  
Mohammad Injamul Hoq ◽  
Israt Jahan ◽  
Shafayet Ahmed Siddiqui ◽  
Chayan Dhar Clinton ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Clinical Studies ◽  
Nigella Sativa ◽  
Biological Effects ◽  
Neuroprotective Activity ◽  
Substantia Nigra Pars Compacta ◽  
Movement Difficulties

: Thymoquinone (TQ) is one of the leading phytochemicals, which is abundantly found in Nigella sativa L. seeds. TQ exhibited various biological effects such as antioxidant, anti-inflammatory, antimicrobial, and anti-tumoral in several pre-clinical studies. Parkinson's disease (PD) is a long-term neurodegenerative disease with movement difficulties, and the common feature of neurodegeneration in PD patients is caused by dopaminergic neural damage in the substantia nigra pars compacta. The neuroprotective activity of TQ has been studied in various neurological disorders. TQ-mediated neuroprotection against PD yet to be reported in a single frame; therefore, this review is intended to narrate the potentiality of TQ in the therapy of PD. TQ has been shown to protect against neurotoxins via amelioration of neuroinflammation, oxidative stress, apoptosis, thereby protects neurodegeneration in PD models. TQ could be an emerging therapeutic intervention in PD management, but mechanistic studies have been remained to be investigated to clarify its neuroprotective role.

scholarly journals Cardiac Cell Therapy: Insights into the Mechanisms of Tissue Repair

2021 ◽  
Vol 22 (3) ◽  
pp. 1201
Author(s):  
Hsuan Peng ◽  
Kazuhiro Shindo ◽  
Renée R. Donahue ◽  
Ahmed Abdel-Latif
Keyword(s):  
Stem Cell ◽  
Immune Responses ◽  
Tissue Repair ◽  
Molecular Mechanisms ◽  
Clinical Evidence ◽  
Current Knowledge ◽  
Cell Delivery ◽  
Cardiac Cell Therapy ◽  
Stem Cell Treatment

Stem cell-based cardiac therapies have been extensively studied in recent years. However, the efficacy of cell delivery, engraftment, and differentiation post-transplant remain continuous challenges and represent opportunities to further refine our current strategies. Despite limited long-term cardiac retention, stem cell treatment leads to sustained cardiac benefit following myocardial infarction (MI). This review summarizes the current knowledge on stem cell based cardiac immunomodulation by highlighting the cellular and molecular mechanisms of different immune responses to mesenchymal stem cells (MSCs) and their secretory factors. This review also addresses the clinical evidence in the field.

Recalcitrant Abdominal Wall Hernias: Long-Term Superiority of Autologous Tissue Repair

2003 ◽  
Vol 112 (1) ◽  
pp. 106-114 ◽  
Author(s):  
John A. Girotto ◽  
Michael Chiaramonte ◽  
Nathan G. Menon ◽  
Navin Singh ◽  
Ron Silverman ◽  
...  
Keyword(s):  
Abdominal Wall ◽  
Tissue Repair ◽  
Autologous Tissue

Apatite Remineralization: In Vivo Long Term Study in Dental Tissue

2003 ◽  
Vol 254-256 ◽  
pp. 695-698
Author(s):  
R.L. Mourão ◽  
Herman S. Mansur ◽  
F.R. Tay ◽  
L. Dlanza
Keyword(s):  
Dental Tissue ◽  
Term Study ◽  
Long Term Study

scholarly journals Effects of Manganese Porphyrins on Cellular Sulfur Metabolism

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 980 ◽  
Author(s):  
Kenneth R. Olson ◽  
Yan Gao ◽  
Andrea K. Steiger ◽  
Michael D. Pluth ◽  
Charles R. Tessier ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Biological Effects ◽  
Sulfur Metabolism ◽  
Hek293 Cells ◽  
Redox Cycle ◽  
Major Site ◽  
Manganese Porphyrins ◽  
Short And Long Term ◽  
H2s Production

Manganese porphyrins (MnPs), MnTE-2-PyP5+, MnTnHex-2-PyP5+ and MnTnBuOE-2-PyP5+, are superoxide dismutase (SOD) mimetics and form a redox cycle between O2 and reductants, including ascorbic acid, ultimately producing hydrogen peroxide (H2O2). We previously found that MnPs oxidize hydrogen sulfide (H2S) to polysulfides (PS; H2Sn, n = 2–6) in buffer. Here, we examine the effects of MnPs for 24 h on H2S metabolism and PS production in HEK293, A549, HT29 and bone marrow derived stem cells (BMDSC) using H2S (AzMC, MeRho-AZ) and PS (SSP4) fluorophores. All MnPs decreased intracellular H2S production and increased intracellular PS. H2S metabolism and PS production were unaffected by cellular O2 (5% versus 21% O2), H2O2 or ascorbic acid. We observed with confocal microscopy that mitochondria are a major site of H2S production in HEK293 cells and that MnPs decrease mitochondrial H2S production and increase PS in what appeared to be nucleoli and cytosolic fibrillary elements. This supports a role for MnPs in the metabolism of H2S to PS, the latter serving as both short- and long-term antioxidants, and suggests that some of the biological effects of MnPs may be attributable to sulfur metabolism.

scholarly journals Protein kinase D promotes plasticity-induced F-actin stabilization in dendritic spines and regulates memory formation

2015 ◽  
Vol 210 (5) ◽  
pp. 771-783 ◽  
Author(s):  
Norbert Bencsik ◽  
Zsófia Szíber ◽  
Hanna Liliom ◽  
Krisztián Tárnok ◽  
Sándor Borbély ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Protein Kinase ◽  
Dendritic Spines ◽  
Morphological Changes ◽  
Long Term Potentiation ◽  
Memory Formation ◽  
Protein Kinase D

Actin turnover in dendritic spines influences spine development, morphology, and plasticity, with functional consequences on learning and memory formation. In nonneuronal cells, protein kinase D (PKD) has an important role in stabilizing F-actin via multiple molecular pathways. Using in vitro models of neuronal plasticity, such as glycine-induced chemical long-term potentiation (LTP), known to evoke synaptic plasticity, or long-term depolarization block by KCl, leading to homeostatic morphological changes, we show that actin stabilization needed for the enlargement of dendritic spines is dependent on PKD activity. Consequently, impaired PKD functions attenuate activity-dependent changes in hippocampal dendritic spines, including LTP formation, cause morphological alterations in vivo, and have deleterious consequences on spatial memory formation. We thus provide compelling evidence that PKD controls synaptic plasticity and learning by regulating actin stability in dendritic spines.

Long-term release of chlorhexidine from dental adhesive resin system using human serum albumin nanoparticles

2014 ◽  
Vol 71 (4) ◽  
pp. 875-886 ◽  
Author(s):  
Hyun-Jin Kim ◽  
Tae-Yub Kwon ◽  
Kyo-Han Kim ◽  
Soon-Taek Kwon ◽  
Dae-Hyun Cho ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Resin System ◽  
Adhesive Resin ◽  
Dental Adhesive ◽  
Albumin Nanoparticles
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