Ahmad, Shakil

[["dc.bibliographiccitation.firstpage","321"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Radiation and Environmental Biophysics"],["dc.bibliographiccitation.lastpage","338"],["dc.bibliographiccitation.volume","52"],["dc.contributor.author","Rave-Fraenk, Margret"],["dc.contributor.author","Malik, Ihtzaz Ahmed"],["dc.contributor.author","Christiansen, Hans"],["dc.contributor.author","Naz, Naila"],["dc.contributor.author","Sultan, Sadaf"],["dc.contributor.author","Amanzada, Ahmad"],["dc.contributor.author","Blaschke, Martina"],["dc.contributor.author","Cameron, Silke"],["dc.contributor.author","Ahmad, Shakil"],["dc.contributor.author","Hess, Clemens Friedrich"],["dc.contributor.author","Ramadori, Giuliano"],["dc.contributor.author","Moriconi, Federico"],["dc.date.accessioned","2018-11-07T09:22:03Z"],["dc.date.available","2018-11-07T09:22:03Z"],["dc.date.issued","2013"],["dc.description.abstract","The liver is considered a radiosensitive organ. However, in rats, high single-dose irradiation (HDI) showed only mild effects. Consequences of fractionated irradiation (FI) in such an animal model have not been studied so far. Rats were exposed to selective liver FI (total dose 60 Gy, 2 Gy/day) or HDI (25 Gy) and were killed three months after the end of irradiation. To study acute effects, HDI-treated rats were additionally killed at several time points between 1 and 48 h. Three months after irradiation, no differences between FI and HDI treatment were found for macroscopically detectable small \"scars\" on the liver surface and for an increased number of neutrophil granulocytes distributed in the portal fields and through the liver parenchyma. As well, no changes in HE-stained tissues or clear signs of fibrosis were found around the portal vessels. Differences were seen for the number of bile ducts being increased in FI- but not in HDI-treated livers. Serum levels indicative of liver damage were determined for alkaline phosphatase (AP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (gamma GT) and lactate dehydrogenase (LDH). A significant increase of AP was detected only after FI while HDI led to the significant increases of AST and LDH serum levels. By performing RT-PCR, we detected up-regulation of matrix metalloproteinases, MMP-2, MMP-9, MMP-14, and of their inhibitors, TIMP-1, TIMP-2 and TIMP-3, shortly after HDI, but not at 3 month after FI or HDI. Overall, we saw punctual differences after FI and HDI, and a diffuse formation of small scars at the liver surface. Lack of \"provisional clot\"-formation and absence of recruitment of mononuclear phagocytes could be one explanation for scar formation as incomplete repair response to irradiation."],["dc.identifier.doi","10.1007/s00411-013-0468-7"],["dc.identifier.isi","000322033000004"],["dc.identifier.pmid","23595725"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/29250"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0301-634X"],["dc.title","Rat model of fractionated (2 Gy/day) 60 Gy irradiation of the liver: long-term effects"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","337"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Shock"],["dc.bibliographiccitation.lastpage","345"],["dc.bibliographiccitation.volume","41"],["dc.contributor.author","Ahmad, Shakil"],["dc.contributor.author","Sultan, Sadaf"],["dc.contributor.author","Naz, Naila"],["dc.contributor.author","Ahmad, Ghayyor"],["dc.contributor.author","Alwahsh, Salamah Mohammad"],["dc.contributor.author","Cameron, Silke"],["dc.contributor.author","Moriconi, Federico"],["dc.contributor.author","Ramadori, Giuliano"],["dc.contributor.author","Malik, Ihtzaz Ahmed"],["dc.date.accessioned","2018-11-07T09:41:37Z"],["dc.date.available","2018-11-07T09:41:37Z"],["dc.date.issued","2014"],["dc.description.abstract","Decreased serum and increased hepatic iron uptake is the hallmark of acute-phase (AP) response. Iron uptake is controlled by iron transport proteins such as transferrin receptors (TfRs) and lipocalin 2 (LCN-2). The current study aimed to understand the regulation of iron uptake in primary culture hepatocytes in the presence/absence of AP mediators. Rat hepatocytes were stimulated with different concentrations of iron alone (0.01, 0.1, 0.5 mM) and AP cytokines (interleukin 6 [IL-6], IL-1, tumor necrosis factor ) in the presence/absence of iron (FeCl3: 0.1 mM). Hepatocytes were harvested at different time points (0, 6, 12, 24 h). Total mRNA and proteins were extracted for reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot. A significant iron uptake was detected with 0.1 mM iron administration with a maximum (133.37 +/- 4.82 mu g/g of protein) at 24 h compared with control and other iron concentrations. This uptake was further enhanced in the presence of AP cytokines with a maximum iron uptake (481 +/- 25.81 mu g/g of protein) after concomitant administration of IL-6 + iron to cultured hepatocytes. Concomitantly, gene expression of LCN-2 and ferritin subunits (light- and heavy-chain ferritin subunits) was upregulated by iron or/and AP cytokines with a maximum at 24 h both at mRNA and protein levels. In contrast, a decreased TfR1 level was detected by IL-6 and iron alone, whereas combination of iron and AP cytokines (mainly IL-6) abrogated the downregulation of TfR1. An increase in LCN-2 release into the supernatant of cultured hepatocytes was observed after addition of iron/AP cytokines into the medium. This increase in secretion was further enhanced by combination of IL-6 + iron. In conclusion, iron uptake is tightly controlled by already present iron concentration in the culture. This uptake can be further enhanced by AP cytokines, mainly by IL-6."],["dc.identifier.doi","10.1097/SHK.0000000000000107"],["dc.identifier.isi","000335648600011"],["dc.identifier.pmid","24365882"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33775"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Lippincott Williams & Wilkins"],["dc.relation.issn","1540-0514"],["dc.relation.issn","1073-2322"],["dc.title","REGULATION OF IRON UPTAKE IN PRIMARY CULTURE RAT HEPATOCYTES: THE ROLE OF ACUTE-PHASE CYTOKINES"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","11471"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","International journal of clinical and experimental pathology"],["dc.bibliographiccitation.lastpage","11479"],["dc.bibliographiccitation.volume","10"],["dc.contributor.author","Ahmad, Shakil"],["dc.contributor.author","Cameron, Silke"],["dc.contributor.author","Naz, Naila"],["dc.contributor.author","Moriconi, Federico"],["dc.date.accessioned","2019-07-10T08:12:06Z"],["dc.date.available","2019-07-10T08:12:06Z"],["dc.date.issued","2017"],["dc.description.abstract","Background: The liver plays a key role in iron homeostasis during injury and hypoxia. Methods: For induction of liver injury, thioacetamide (TAA) was administered intraperitoneally to male Sprague Dawley rats. Animals were sacrificed at 0, 1, 3, 6, 12, 24, 48, 72 and 96 h. Serum, liver, spleen and heart tissues were collected from control and TAA-treated rats. Tissue sections were prepared for immunohistochemical studies. Nuclear and cytoplasmic proteins were isolated for Western blot analysis. Results: Hypoxia inducible factor (HIF)-1α and ED1 positive cells accumulated around the portal field and the interlobular space within 12 hours after TAA administration. Accordingly, Western blot analysis of liver tissue showed an early increase of HIF1α followed by a decrease at 48 h to 96 h. For Erythropoietin (EPO), as well as for HIF1- and -2α, a time-dependent translocation was observed from the cytoplasmic to the nuclear compartment. Conclusion: Our data suggest that the TAA-induced acute liver damage generates HIF-1α dependent rescue mechanisms with translocation of EPO from the cytoplasmic to the nuclear compartment. Enhanced iron transport into the liver could be necessary for increased metabolic activities during repair processes."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2017"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15018"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/60864"],["dc.language.iso","en"],["dc.notes.intern","Migrated from goescholar"],["dc.relation.issn","1936-2625"],["dc.rights.access","openAccess"],["dc.subject","Thioacetamide (TAA); acute phase injury; hypoxia inducible factor (HIF); erythropoietin (EPO)"],["dc.subject.ddc","610"],["dc.title","Mediators of hypoxia in a rat model of sterile-induced acute liver injury"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","459"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Liver International"],["dc.bibliographiccitation.lastpage","468"],["dc.bibliographiccitation.volume","33"],["dc.contributor.author","Sultan, Sadaf"],["dc.contributor.author","Cameron, Silke"],["dc.contributor.author","Ahmad, Shakil"],["dc.contributor.author","Malik, Ihtzaz Ahmed"],["dc.contributor.author","Schultze, Frank Christian"],["dc.contributor.author","Hielscher, Ruth"],["dc.contributor.author","Rave-Fraenk, Margret"],["dc.contributor.author","Hess, Clemens Friedrich"],["dc.contributor.author","Ramadori, Giuliano"],["dc.contributor.author","Christiansen, Hans"],["dc.date.accessioned","2018-11-07T09:27:53Z"],["dc.date.available","2018-11-07T09:27:53Z"],["dc.date.issued","2013"],["dc.description.abstract","Background/Aim IL-6 IL-1 lipocalin2 (LCN2) liver irradiation oxidative stress TNF-a Lipocalin2 (LCN2) is an acute phase protein. The source of its increased serum level in oxidative stress conditions (ROS) remains still unknown. We prospectively evaluate the serum LCN2 increase after single dose liver irradiation along with hepatic LCN2 gene and protein expression. Methods A single dose of 25 Gray was administered percutaneously to the liver of randomly paired rats after a planning CT scan. Male Wistar rats were sacrificed 1, 3, 6, 12, 24 and 48h after irradiation along with sham-irradiated controls. ELISA, RT-PCR, Western blot and immunofluorescence staining was performed. Furthermore, hepatocytes, myofibroblasts and Kupffer cells were isolated from the liver of healthy rats and irradiated ex-vivo. Results After liver irradiation, LCN2 serum levels increased significantly up to 2.7g/ml within 6h and stayed elevated over 24h. LCN2 specific transcripts increased significantly up to 552 +/- 109-fold at 24h after liver irradiation, which was further confirmed at protein level. 2-macroglobulin and hemoxygenase-1 also showed an increase, but the magnitude was less as compared to LCN2. LCN2+ granulocytes were detected within 1h after irradiation around central and portal fields and remained high during the course of study. Ex-vivo irradiated hepatocytes (2.4 +/- 0.6-fold) showed a higher LCN2 gene expression as compared to myofibroblasts and Kupffer cells. IL-1 treatment further increased LCN2 gene expression in cultured hepatocytes. Conclusions Single dose liver irradiation induces a significant increase in LCN2 serum levels, comparable to the induction of acute phase proteins. We suggest LCN2 as marker for the early phase of radiation-induced tissue damage."],["dc.description.sponsorship","Deutsche Krebshilfe [108774]"],["dc.identifier.doi","10.1111/liv.12073"],["dc.identifier.isi","000314984200016"],["dc.identifier.pmid","23331620"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/30644"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1478-3223"],["dc.title","Serum Lipocalin2 is a potential biomarker of liver irradiation damage"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","637"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","International Journal of Molecular Sciences"],["dc.bibliographiccitation.volume","17"],["dc.contributor.author","Sultan, Sadaf"],["dc.contributor.author","Ahmad, Shakil"],["dc.contributor.author","Rave-Fraenk, Margret"],["dc.contributor.author","Malik, Ihtzaz Ahmed"],["dc.contributor.author","Hess, Clemens Friedrich"],["dc.contributor.author","Christiansen, Hans"],["dc.contributor.author","Cameron, Silke"],["dc.date.accessioned","2018-11-07T10:14:35Z"],["dc.date.available","2018-11-07T10:14:35Z"],["dc.date.issued","2016"],["dc.description.abstract","Previously, we showed that lipocalin2 (LCN2) serum levels increased after liver irradiation and during acute-phase conditions. Here, we evaluate LCN2 expression and serum levels after single-dose lung irradiation with 25 Gy, percutaneously administered to the lung of randomly-paired male Wistar rats. Due to the concave anatomy of the lung recesses, the irradiation field included the upper part of the liver. No rat died due to irradiation. In control tissue, lung immunohistochemistry showed a high constitutive expression of LCN2+ granulocytes. LCN2 mRNA levels in lung tissue increased up to 24 h (9 +/- 2.3-fold) after irradiation. However, serum LCN2 levels remained undetectable after lung irradiation. LCN2 expression in the upper part of the liver increased up to 4.2-fold after lung irradiation, but the lower liver showed an early decrease. Acute-phase cytokines (IL-1 beta and TNF-beta) showed a significant increase on transcript level in both lung and upper liver, whilst the lower liver did not show any considerable increase. In conclusion, constitutive expression of LCN2 in local immune cells demonstrates its local role during stress conditions in the lung. The absence of LCN2 in the serum strengthens our previous findings that the liver is the key player in secreting LCN2 during stress conditions with liver involvement."],["dc.description.sponsorship","Open-Access Publikationsfonds 2016"],["dc.identifier.doi","10.3390/ijms17050637"],["dc.identifier.isi","000378791400031"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/13241"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/40644"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Mdpi Ag"],["dc.relation.issn","1422-0067"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","Induction of Lipocalin2 in a Rat Model of Lung Irradiation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","15"],["dc.bibliographiccitation.journal","Journal of Clinical Oncology"],["dc.bibliographiccitation.volume","30"],["dc.contributor.author","Sultan, Sadaf"],["dc.contributor.author","Ramadori, Giuliano"],["dc.contributor.author","Ahmad, Shakil"],["dc.contributor.author","Rave-Fraenk, Margret"],["dc.contributor.author","Christiansen, Hans"],["dc.contributor.author","Cameron, Silke"],["dc.date.accessioned","2018-11-07T09:10:23Z"],["dc.date.available","2018-11-07T09:10:23Z"],["dc.date.issued","2012"],["dc.identifier.isi","000318009801647"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/26476"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Soc Clinical Oncology"],["dc.publisher.place","Alexandria"],["dc.relation.conference","48th Annual Meeting of the American-Society-of-Clinical-Oncology (ASCO)"],["dc.relation.eventlocation","Chicago, IL"],["dc.relation.issn","0732-183X"],["dc.title","Serum lipocalin-2 as a potential biomarker of liver irradiation."],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","353106"],["dc.bibliographiccitation.journal","BioMed Research International"],["dc.contributor.author","Naz, Naila"],["dc.contributor.author","Ahmad, Shakil"],["dc.contributor.author","Cameron, Silke"],["dc.contributor.author","Moriconi, Federico"],["dc.contributor.author","Rave-Fraenk, Margret"],["dc.contributor.author","Christiansen, Hans"],["dc.contributor.author","Hess, Clemens Friedrich"],["dc.contributor.author","Ramadori, Giuliano"],["dc.contributor.author","Malik, Ihtzaz Ahmed"],["dc.date.accessioned","2018-11-07T09:29:26Z"],["dc.date.available","2018-11-07T09:29:26Z"],["dc.date.issued","2013"],["dc.description.abstract","The current study aimed to investigate radiation-induced regulation of iron proteins including ferritin subunits in rats. Rat livers were selectively irradiated in vivo at 25 Gy. This dose can be used to model radiation effects to the liver without inducing overt radiation-induced liver disease. Sham-irradiated rats served as controls. Isolated hepatocytes were irradiated at 8 Gy. Ferritin light polypeptide (FTL) was detectable in the serum of sham-irradiated rats with an increase after irradiation. Liver irradiation increased hepatic protein expression of both ferritin subunits. A rather early increase (3 h) was observed for hepatic TfR1 and Fpn-1 followed by a decrease at 12 h. The increase in TfR2 persisted over the observed time. Parallel to the elevation of AST levels, a significant increase (24 h) in hepatic iron content was measured. Complete blood count analysis showed a significant decrease in leukocyte number with an early increase in neutrophil granulocytes and a decrease in lymphocytes. In vitro, a significant increase in ferritin subunits at mRNA level was detected after irradiation which was further induced with a combination treatment of irradiation and acute phase cytokine. Irradiation can directly alter the expression of ferritin subunits and this response can be strongly influenced by radiation-induced proinflammatory cytokines. FTL can be used as a serum marker for early phase radiation-induced liver damage."],["dc.description.sponsorship","DFG [MA-5488/2-1]"],["dc.identifier.doi","10.1155/2013/353106"],["dc.identifier.isi","000328832300001"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10734"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/31028"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Hindawi Publishing Corporation"],["dc.relation.issn","2314-6141"],["dc.relation.issn","2314-6133"],["dc.rights","CC BY 3.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/3.0"],["dc.title","Differential Regulation of Ferritin Subunits and Iron Transport Proteins: An Effect of Targeted Hepatic X-Irradiation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]