Isospin Effects: Nuclear Fragmentation as a Probe

2020 ◽  
pp. 51-64
Author(s):  
Preeti Bansal ◽  
Sakshi Gautam ◽  
Rajeev K. Puri
Keyword(s):  
Nuclear Fragmentation

Critical phenomena in nuclear fragmentation

2000 ◽  
Vol 23 (2) ◽  
pp. 1-101
Author(s):  
A. Bonasera ◽  
M. Bruno ◽  
C. O. Dorso ◽  
P. F. Mastinu
Keyword(s):  
Critical Phenomena ◽  
Nuclear Fragmentation

Collective flow in nuclear fragmentation induced by 4.4 GeV deuteron on gold target

2011 ◽  
Vol 8 (1) ◽  
pp. 19-22 ◽  
Author(s):  
V. A. Karnaukhov ◽  
S. P. Avdeyev ◽  
H. Oeschler ◽  
V. V. Kirakosyan ◽  
P. A. Rukoyatkin ◽  
...  
Keyword(s):  
Collective Flow ◽  
Nuclear Fragmentation ◽  
Gold Target

Increased cell death in osteopontin-deficient cardiac fibroblasts occurs by a caspase-3-independent pathway

2004 ◽  
Vol 287 (4) ◽  
pp. H1730-H1739 ◽  
Author(s):  
Ron Zohar ◽  
Baoqian Zhu ◽  
Peter Liu ◽  
Jaro Sodek ◽  
C. A. McCulloch
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Cardiac Fibroblasts ◽  
Chromatin Condensation ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tunel Staining ◽  
Wild Type ◽  
Nuclear Fragmentation ◽  
A Cell

Reperfusion-induced oxidative injury to the myocardium promotes activation and proliferation of cardiac fibroblasts and repair by scar formation. Osteopontin (OPN) is a proinflammatory cytokine that is upregulated after reperfusion. To determine whether OPN enhances fibroblast survival after exposure to oxidants, cardiac fibroblasts from wild-type (WT) or OPN-null (OPN−/−) mice were treated in vitro with H2O2to model reperfusion injury. Within 1 h, membrane permeability to propidium iodide (PI) was increased from 5 to 60% in OPN−/−cells but was increased to only 20% in WT cells. In contrast, after 1–8 h of treatment with H2O2, the percent of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-stained cells was more than twofold higher in WT than OPN−/−cells. Electron microscopy of WT cells treated with H2O2showed chromatin condensation, nuclear fragmentation, and cytoplasmic and nuclear shrinkage, which are consistent with apoptosis. In contrast, H2O2-treated OPN−/−cardiac fibroblasts exhibited cell and nuclear swelling and membrane disruption that are indicative of cell necrosis. Treatment of OPN−/−and WT cells with a cell-permeable caspase-3 inhibitor reduced the percentage of TUNEL staining by more than fourfold in WT cells but decreased staining in OPN−/−cells by ∼30%. Although the percentage of PI-permeable WT cells was reduced threefold, the percent of PI-permeable OPN−/−cells was not altered. Restoration of OPN expression in OPN−/−fibroblasts reduced the percentage of PI-permeable cells but not TUNEL staining after H2O2treatment. Thus H2O2-induced cell death in OPN-deficient cardiac fibroblasts is mediated by a caspase-3-independent, necrotic pathway. We suggest that the increased expression of OPN in the myocardium after reperfusion may promote fibrosis by protecting cardiac fibroblasts from cell death.

Description of (Hyper-)Fragments in Hadron-Induced Reactions

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1887
Author(s):  
Theodoros Gaitanos
Keyword(s):  
Nuclear Reactions ◽  
Heavy Ion ◽  
Nuclear Fragmentation ◽  
Equilibrium Dynamics ◽  
Ion Collisions ◽  
Light Ions ◽  
Classical Transport ◽  
Nuclear Targets ◽  
Fragmentation Processes

In this article we review the important role of non-equilibrium dynamics in reactions induced by ions and hadron beams to understand the fragmentation processes inside hadronic media. We discuss the single-particle dynamics in specific sources such as spectators in heavy-ion collisions and residual nuclear targets in hadron-induced reactions. Particular attention is given to the dynamics of hyperons. We further discuss the question regarding the onset of local instabilities, which are relevant for the appearance of fragmentation phenomena in nuclear reactions. We apply the theoretical formalism, that is, semi-classical transport embedded with statistical methods of nuclear fragmentation, to reactions induced by light ions and hadron beams. We discuss the results of nuclear fragmentation and, in particular, examine the formation of hypernuclei. Such studies are important for obtaining a deeper understanding of the equation of state in fragmenting matter and are relevant for forthcoming experiments, such as PANDA at FAIR and J-PARC in Japan.

Essential role for cathepsin D in bleomycin-induced apoptosis of alveolar epithelial cells

2004 ◽  
Vol 287 (1) ◽  
pp. L46-L51 ◽  
Author(s):  
Xiaopeng Li ◽  
Heather Rayford ◽  
Ruijie Shu ◽  
Jiaju Zhuang ◽  
Bruce D. Uhal
Keyword(s):  
Enzymatic Activity ◽  
Cathepsin D ◽  
Alveolar Epithelial Cells ◽  
Type Ii ◽  
Ang Ii ◽  
Nuclear Fragmentation ◽  
Alveolar Epithelial ◽  
Induced Apoptosis ◽  
Pepstatin A

Our earlier studies showed that bleomycin-induced apoptosis of type II alveolar epithelial cells (AECs) requires the autocrine synthesis and proteolytic processing of angiotensinogen into ANG II and that inhibitors of ANG-converting enzyme (ACEis) block bleomycin-induced apoptosis (Li X, Zhang H, Soledad-Conrad V, Zhuang J, and Uhal BD. Am J Physiol Lung Cell Mol Physiol 284: L501–L507, 2003). Given the documented role of cathepsin D (CatD) in apoptosis of other cell types, we hypothesized that CatD might be the AEC enzyme responsible for the conversion of angiotensinogen into ANG I, the substrate for ACE. Primary cultures of rat type II AECs challenged with bleomycin in vitro showed upregulation and secretion of CatD enzymatic activity and immunoreactive protein but no increases in CatD mRNA. The aspartyl protease inhibitor pepstatin A, which completely blocked CatD enzymatic activity, inhibited bleomycin-induced nuclear fragmentation by 76% and reduced bleomycin-induced caspase-3 activation by 47%. Antisense oligonucleotides against CatD mRNA reduced CatD-immunoreactive protein and inhibited bleomycin-induced nuclear fragmentation by 48%. A purified fragment of angiotensinogen (F1–14) containing the CatD and ACE cleavage sites, when applied to unchallenged AEC in vitro, yielded mature ANG II peptide and induced apoptosis. The apoptosis induced by F1–14 was inhibited 96% by pepstatin A and 77% by neutralizing antibodies specific for CatD (both P < 0.001). These data indicate a critical role for CatD in bleomycin-induced apoptosis of cultured AEC and suggest that the role(s) of CatD in AEC apoptosis include the conversion of newly synthesized angiotensinogen to ANG II.

Selective targeting of cyclooxygenase-2 reveals its role in renal medullary interstitial cell survival

1999 ◽  
Vol 277 (3) ◽  
pp. F352-F359 ◽  
Author(s):  
Chuan-Ming Hao ◽  
Martin Kömhoff ◽  
Youfei Guan ◽  
Reyadh Redha ◽  
Matthew D. Breyer
Keyword(s):  
Cell Survival ◽  
Interstitial Cell ◽  
Renal Medulla ◽  
Selective Inhibitor ◽  
Nuclear Fragmentation ◽  
Major Site ◽  
Associated Injury ◽  
Selective Targeting ◽  
Inflammatory Drugs

Renal medullary interstitial cells (MICs) are a major site of cyclooxygenase (COX)-mediated PG synthesis. These studies examined the role of COX in MIC survival. Immunoblot and nuclease protection demonstrate that cultured MICs constitutively express COX2, with little constitutive COX1 expression. SC-58236, a COX2-selective inhibitor, but not SC-58560, a COX1 inhibitor, preferentially blocks PGE2 synthesis in MICs. Transduction with a COX2 antisense adenovirus reduced MIC COX2 protein expression and also decreased PGE2production. Antisense downregulation of COX2 was associated with MIC death, whereas a control adenovirus was without effect. Similarly, the COX2-selective inhibitor SC-58236 (30 μM) and several nonselective COX-inhibiting nonsteroidal anti-inflammatory drugs (NSAIDs), including sulindac, ibuprofen, and indomethacin, all caused MIC death. In contrast, SC-58560, a COX1-selective inhibitor, was 100-fold less potent for inducing MIC death than its structural congener SC-58236. NSAID-induced MIC death was associated with DNA laddering and nuclear fragmentation, consistent with apoptosis. These results suggest that COX2 plays an important role in MIC survival. COX2 inhibition may contribute to NSAID-associated injury of the renal medulla.

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