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Fralick M, Bouganim N, Kremer R, Kekre N, Robertson S, Vandermeer L, Kuchuk I, Li J, Murshed M, Clemons M. Histomorphometric and microarchitectural analyses using the 2 mm bone marrow trephine in metastatic breast cancer patients-preliminary results. J Bone Oncol 2012; 1:69-73. [PMID: 26909259 PMCID: PMC4723346 DOI: 10.1016/j.jbo.2012.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 10/31/2012] [Accepted: 10/31/2012] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Bone-targeted agents are widely used for the treatment of osteoporosis, the prevention of cancer-therapy induced bone loss, and for reducing the risk of skeletal related events in patients with metastatic disease. Despite widespread use, relatively little is known about the in vivo effect of these agents on bone homeostasis, bone quality, and bone architecture in humans. Traditionally bone quality has been assessed using a transiliac bone biopsy with a 7 mm "Bordier" core needle. We examined the possibility of using a 2 mm "Jamshidi" core needle as a more practical and less invasive method to assess bone turnover and potentially other tumor effects. METHODS A pilot study on the feasibility of assessing bone quality and microarchitecture and tumor invasion using a 2 mm bone marrow trephine was conducted. Patients underwent a posterior trans-iliac trephine biopsy and bone marrow aspirate. Samples were analyzed for bone microarchitecture, bone density, and histomorphometry. The study plan was to accrue three patients with advanced breast cancer to assess the feasibility of the study before enrolling more patients. RESULTS The procedure was well tolerated. The sample quality was excellent to analyze bone trabecular microarchitecture using both microCT and histomorphometry. Intense osteoclastic activity was observed in a patient with extensive tumor burden in bone despite intravenous bisphosphonate therapy. DISCUSSION Given the success of this study for assessing bone microarchitecture, bone density, and histomorphometry assessment using a 2 mm needle the study will be expanded beyond these initial three patients for longitudinal assessment of bone-targeted therapy.
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Broza YY, Kremer R, Tisch U, Gevorkyan A, Shiban A, Best LA, Haick H. A nanomaterial-based breath test for short-term follow-up after lung tumor resection. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2012; 9:15-21. [PMID: 22967910 DOI: 10.1016/j.nano.2012.07.009] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 07/24/2012] [Accepted: 07/31/2012] [Indexed: 12/17/2022]
Abstract
UNLABELLED In this case study, we demonstrate the feasibility of nanomaterial-based sensors for identifying the breath-print of early-stage lung cancer (LC) and for short-term follow-up after LC-resection. Breath samples were collected from a small patient cohort prior to and after lung resection. Gas-chromatography/mass-spectrometry showed that five volatile organic compounds were significantly reduced after LC surgery. A nanomaterial-based sensor-array distinguished between pre-surgery and post-surgery LC states, as well as between pre-surgery LC and benign states. In contrast, the same sensor-array could neither distinguish between pre-surgery and post-surgery benign states, nor between LC and benign states after surgery. This indicates that the observed pattern is associated with the presence of malignant lung tumors. The proof-of-concept presented here has initiated a large-scale clinical study for post-surgery follow-up of LC patients. FROM THE CLINICAL EDITOR Monitoring for tumor recurrence remains very challenging due to post-surgical and radiation therapy induced changes in target organs, which often renders standard radiological identification of recurrent malignancies inaccurate. In this paper a novel nanotechnology-based sensor array is used for identification of volatile organic compounds in exhaled air that enable identification of benign vs. malignant states.
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Arad T, Levi-Faber D, Nir RR, Kremer R. [The learning curve of video-assisted thoracoscopic surgery (VATS) for lung lobectomy--a single Israeli center experience]. HAREFUAH 2012; 151:261-320. [PMID: 22844727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND Video-assisted thoracoscopic surgery (VATS) is a method of lung lobe resection that has been implemented in medical centers worldwide since 1992. This procedure utilizes video equipment to assist in performing lobectomies without the need to open the chest wall As of 2009, VATS has been performed in the generaL thoracic surgery department of Rambam HeaLthcare Campus, Haifa. Since then, more than 200 patients were successfully operated on using this method. This study analyzed the Learning curve experienced by its surgeons and departmental staff since VATS implementation. METHODS Patient files for all cases which underwent VATS in the department from January 2009 to June 2010 were retrospectively evaluated. The patients were divided into three groups based on their operation date; each group included patients that were operated on during a half-year interval. Data was collected and compared between the groups in regard to the percentage of surgeries that used VATS versus procedures which involved opening the chest wall, procedure time, duration of hospital stay, conversion ratios for closed to open operations, and intra and post-operative complications. Subsequent results were then compared to those reported from other countries around the world. RESULTS VATS Lobectomies comprised the smallest percentage of the total Lobectomies performed in the department during the first 6 months of analysis (January 2009 - June 2009] as compared to the following year of analysis (July 2009 - June 2010), that involved a much more extensive use of VATS. The first 6 months of VATS implementation also involved fewer intra-operative complications and shorter operation times as compared to the following year. The length of stay and the number of post-operative complications were similar in each time interval analyzed. CONCLUSIONS VATS lobectomy requires surgeons and departmental staff to face a steep learning curve. Operators should invest 6-12 months usage of VATS and perform 30-60 operations in order to achieve constant results that are consistent with those reported from other medical centers worldwide.
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Faber DL, Best LA, Orlovsky M, Lapidot M, Nir RR, Kremer R. Streptokinase fibrinolysis protocol: the advantages of a non-operative treatment for stage II pediatric empyema patients. THE ISRAEL MEDICAL ASSOCIATION JOURNAL : IMAJ 2012; 14:157-161. [PMID: 22675854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND Pediatric empyema necessitates prompt resolution and early hospital discharge with minimal morbidity. However, the most effective treatment approach is not yet established. OBJECTIVES To assess the efficacy of an intrapleural streptokinase washing protocol as a non-operative treatment for stage II pediatric empyema as compared to operative decortications, by the number of pediatric intensive care unit (PICU) admissions, length of PICU stay, and hospitalization duration. METHODS We retrospectively evaluated 75 consecutive pediatric empyema cases for the period January 2006 to December 2009. Since July 2007 we have used repeated streptokinase-based pleural washing for stage II patients whose condition did not improve with chest drainage RESULTS Before July 2007, 17 of 23 stage II empyema patients underwent decortication, compared to only 1 of 21 after July 2007. Non-operated children were admitted to the PICU less frequently than those who were operated (83% vs. 31%, p = 0.0006) and spent less time in the PICU (2.56 +/- 1.92 vs. 1.04 +/- 1.9 days, P= 0.0148); there was no significant statistical difference in overall hospitalization (13.33 +/- 3.69 vs.11.70 +/- 5.74 days, P= 0.301). CONCLUSIONS Using intrapleural streptokinase washing as a non-operative treatment for stage II pediatric empyema yielded comparable success rates to the operative approach, with less morbidity.
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Mihalcioiu C, Lian J, Bertos N, Omeroglu A, Sebag M, DiBattista J, Li J, Chughtai N, Park M, Kremer R. P4-07-02: Detection, Enrichment, Characterization and Propagation of Circulating Tumour Cells from Patients with Advanced Metastatic Breast Cancer. Cancer Res 2011. [DOI: 10.1158/0008-5472.sabcs11-p4-07-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Circulating tumour cells (CTCs) have attracted much attention lately due to their potential utility in diagnostic, therapeutic and prognostic applications. Characterization of these cells may indeed permit more targeted and individualized therapeutic approaches, as well as provide a means to monitor treatment response. Although detection of CTCs in peripheral blood (PB) is relatively easy using current methodologies, characterization of the CTC pool has proven more challenging due to their low abundance. Furthermore, in-vitro expansion of this elusive cell pool in mammosphere cultures has not yet been reported. In order to achieve a more complete characterization of CTCs and attempt to obtain live cells in sufficient quantity for in vitro expansion, we have used aphaeresis as a means to collect a large initial cell fraction from which to enrich CTCs from peripheral blood.
Methods: A cohort (n=17) of late stage breast cancer patients were first screened using 10ml PB. Peripheral blood mononuclear cells (PBMCs) were isolated using a Ficoll gradient and then enriched for CTCs by anti-CD45 negative selection using an automated system (RoboSep) based on magnetic bead separation. CTCs were detected by immunocytochemistry (ICC) for cytokeratin expression and patients classified as CTC-positive were selected for the aphaeresis procedure. Following collection of aphaeresis material (APM), PBMCs were isolated using a Ficoll gradient, enriched by automated anti-CD45 negative selection and characterized for a variety of markers by ICC, immunofluorescence and flow cytometry. CTCs were then cultured in serum-free medium as monolayers and suspensions. Recovery at the various steps of the isolation process was determined using PB from healthy subjects spiked with MCF-7 breast cancer cells and processed using the same approach.
Results: Recovery of spiked MCF-7 cells was about 40% after Ficoll and magnetic bead separation. Using this negative selection procedure 17/17 (100%) of subjects tested were positive at screening. Most patients (14/17) underwent aphaeresis and a large number (9,600 to 108,000) of enriched CTCs was recovered from APM in all patients tested, either as individual cells or as CTC clusters. Using dual immunofluorescence labelling, co-localization of the epithelial cell marker CK8 and the chemokine receptor CXCR4 was observed within CTCs. Furthermore, over 20% of CTCs were positive for both CK8 and ALDH1, indicative of a stem-like phenotype. APM-derived CTCs from all patients (14/14) could be propagated, both as attached cells and in suspension culture. They formed colonies in monolayer culture, and clusters in mammosphere culture, indicating stem cell-like properties. They replicated for at least three passages in mammosphere culture.
Conclusion: Our CTC detection and enrichment method using negative selection offers a distinct advantage over current methodologies, including collection of clusters, and the ability to grow and expand CTCs in serum-free culture conditions. Furthermore, these cells demonstrate breast cancer stem cell-like characteristics, the ability to replicate for multiple passages as mammospheres in suspensions and a metastatic signature.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-02.
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Brauner E, Lapidot M, Kremer R, Best LA, Kluger Y. Aberrant right subclavian artery- suggested mechanism for esophageal foreign body impaction: Case report. World J Emerg Surg 2011; 6:12. [PMID: 21477337 PMCID: PMC3089779 DOI: 10.1186/1749-7922-6-12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2011] [Accepted: 04/09/2011] [Indexed: 11/10/2022] Open
Abstract
Aberrant right subclavian artery (ARSA) is asymptomatic in most cases. This variant anatomy can cause dysphagia in elderly patients. Impaction of foreign body in the esophagus is rarely the presenting symptom of ARSA. We present an eighty four years old patient who first presented with esophageal foreign body impaction and was diagnosed with an aberrant right subclavian artery compressing the esophagus just below the site of impaction. We assume that the exact place of impaction was not incidental and that a relative narrowing of the esophagus caused by the vascular anomaly is responsible for this specific presentation.
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Faber DL, Kremer R, Orlovsky M, Lapidot M, Guralnik L, Kagna O, Wollner M, Nir R, Yigla M, Best L. 65P DOES PET-CT BASED CLINICAL STAGING OF NON-SMALL CELL LUNG CANCER OBVIATE INVASIVE PROCEDURES? Lung Cancer 2011. [DOI: 10.1016/s0169-5002(11)70202-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Sienra I, Neimaur K, Kremer R, Urioste JI. Medullated fibres and fleece characteristics in Corriedale hoggets from two flocks in Uruguay. ANIMAL PRODUCTION SCIENCE 2011. [DOI: 10.1071/an11031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The incidence of medullation in 549 Corriedale hoggets from two experimental flocks, its association with other characteristics of the fleece, and the sire effect were evaluated. The investigation was carried out during 2005–06 in hoggets from the Faculty of Agriculture and Faculty of Veterinary Science experimental flocks. Fleeces were weighed and samples were taken at shearing by picking 104 staples from fleeces to measure medullation. A mid-side wool sample was taken to determine wool characteristics (fleece weight, wool yield, mean fibre diameter, staple strength and length). A Dark Fibre Detector was used to identify total medullated fibres and fibre type: medullated fibres (med) and kemp, which were confirmed by light microscope. Mean total medullated fibres, med and kemp content per 10 g of clean wool were 4.2 ± 11.2; 2.0 ± 8.9 and 2.3 ± 4.9, and median values were 0.9, 0.0 and 0.7, respectively, in 549 fleeces. A high variability between samples and a higher proportion of hoggets with kemp fibres than those with med were observed. There were significant differences between sire families for total medullated fibre content/10 g, med fibre content/10 g and kemp fibre content/10 g, but there were no significant effects between flocks, years or interaction between them. Phenotypic correlations between medullated fibre content and wool characteristics were generally low (less than 0.19). In conclusion, medullated fibre content was highly variable between samples and was not strongly correlated with other fleece characteristics. Medullation varied between sire groups, suggesting genetic variation, which could be exploited to improve wool quality.
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Nash E, Coonar A, Kremer R, Tullis E, Hutcheon M, Singer L, Keshavjee S, Chaparro C. Survival of Burkholderia cepacia sepsis following lung transplantation in recipients with cystic fibrosis. Transpl Infect Dis 2010; 12:551-4. [DOI: 10.1111/j.1399-3062.2010.00525.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kremer R, Best LA, Savulescu D, Gavish M, Nagler RM. Pleural fluid analysis of lung cancer vs benign inflammatory disease patients. Br J Cancer 2010; 102:1180-4. [PMID: 20216542 PMCID: PMC2853096 DOI: 10.1038/sj.bjc.6605607] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Correct diagnosis of pleural effusion (PE) as either benign or malignant is crucial, although conventional cytological evaluation is of limited diagnostic accuracy, with relatively low sensitivity rates. METHODS We identified biological markers accurately detected in a simple PE examination. We analysed data from 19 patients diagnosed with lung cancer (nine adeno-Ca, five non-small-cell Ca (not specified), four squamous-cell Ca, one large-cell Ca) and 22 patients with benign inflammatory pathologies: secondary to trauma, pneumonia or TB. RESULTS Pleural effusion concentrations of seven analysed biological markers were significantly lower in lung cancer patients than in benign inflammatory patients, especially in matrix metalloproteinase (MMP)-9, MMP-3 and CycD1 (lower by 65% (P<0.000003), 40% (P<0.0007) and 34% (P<0.0001), respectively), and in Ki67, ImAnOx, carbonyls and p27. High rates of sensitivity and specificity values were found for MMP-9, MMP-3 and CycD1: 80 and 100%; 87 and 73%; and 87 and 82%, respectively. CONCLUSION Although our results are of significant merit in both the clinical and pathogenetic aspects of lung cancer, further research aimed at defining the best combination for marker analysis is warranted. The relative simplicity in analysing these markers in any routine hospital laboratory may result in its acceptance as a new diagnostic tool.
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Kremer R. Die Veränderung der Religiosität durch die Krisensituation „Schlaganfall”. AKTUELLE NEUROLOGIE 2009. [DOI: 10.1055/s-0028-1090227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Levy-Faber D, Kremer R, Orlovsky M, Barak M, Best LA. [Surgical management of esophageal pathology: 6 years of experience in a single surgical department]. HAREFUAH 2009; 148:149-212. [PMID: 19485270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
BACKGROUND Esophageal diseases vary in relation to geographic and behavioral factors. Whether benign or malignant, these diseases interfere with food swallowing. Surgical treatment is variable and aims at restoring the alimentary tract continuity. In this research the authors retrospectively studied esophageal pathologies and their surgical treatment in their department over a 6 year period. PATIENTS AND METHODS The records of all patients who underwent surgery for esophageal pathology in a single surgical department at a referral center between January 2002 and December 2007 were reviewed. Data that was collected included patient age, gender, type of pathology, staging, type and length of surgery, length of hospital stay, post-operative morbidity and mortality. RESULTS During the study period, 186 patients were operated for esophageal pathology, 154 (83%) had malignant disease and 32 (17%) had benign disease. The distribution of malignancy types was: adenocarcinoma 57%, squamous cell carcinoma 27%, signet ring cell carcinoma 8%, and other 8%. Median length of post-operative hospital stay was 27 days. Thirty two percent of the patients experienced complications, including anastomotic leak (10%), respiratory (9.5%) or cardiac (2%) complications, and infection (7.5%), while 3% required re-operation. Postoperative mortality rate in the hospital was 6.5%. CONCLUSIONS The majority of patients undergoing esophageal surgery suffer malignancy, mainly adenocarcinoma. The surgery is extensive and is followed by a long recovery period, during which the patient is subject to a variety of complications. Mortality rate is significant yet comparable to centers around the world with high volume of esophageal operations.
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Cohen E, Doweck I, Naroditsky I, Ben-Izhak O, Kremer R, Best LA, Vlodavsky I, Ilan N. Heparanase is overexpressed in lung cancer and correlates inversely with patient survival. Cancer 2008; 113:1004-11. [PMID: 18618498 DOI: 10.1002/cncr.23680] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Heparanase is an endo-beta-D-glucuronidase that is capable of cleaving heparan sulfate (HS) side chains at a limited number of sites, yielding HS fragments of still appreciable size (approximately 5-7 kDa). Heparanase activity has been detected frequently in several cell types and tissues. Heparanase activity correlates with the metastatic potential of tumor-derived cells, a correlation that has been attributed to enhanced cell dissemination as a consequence of HS cleavage and remodeling of the extracellular matrix barrier. METHODS In this study, the authors examined heparanase expression in 114 patients with lung cancer by means of immunohistochemistry and correlated clinical-pathologic data with heparanase immunostaining and cellular localization. RESULTS Heparanase was overexpressed in 75% of the study patients. Heparanase expression was correlated with lung cancer lymph node status and metastasis classification (P = .04 and P = .01, respectively) and was correlated inversely with patient survival (P = .007). It is noteworthy that this adverse effect depended largely on the cellular localization of heparanase. Thus, whereas cytoplasmic staining of heparanase is associated with a poor prognosis, nuclear heparanase predicts a favorable outcome for patients with lung cancer. CONCLUSIONS The current findings suggest that heparanase expression and cellular localization are decisive for lung cancer patients' prognosis, most likely because of heparanase-mediated tumor cell dissemination by blood and lymph vessels.
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Blum S, Asaf R, Guetta J, Miller-Lotan R, Asleh R, Kremer R, Levy NS, Berger FG, Aronson D, Fu X, Zhang R, Hazen SL, Levy AP. Haptoglobin Genotype Determines Myocardial Infarct Size in Diabetic Mice. J Am Coll Cardiol 2007; 49:82-7. [PMID: 17207726 DOI: 10.1016/j.jacc.2006.08.044] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2006] [Revised: 07/26/2006] [Accepted: 08/08/2006] [Indexed: 11/26/2022]
Abstract
OBJECTIVES We sought to understand the importance of oxidative stress in explaining why the haptoglobin (Hp) genotype determines myocardial infarction (MI) size in diabetes mellitus (DM). BACKGROUND Two common alleles (1 and 2) exist at the Hp locus in humans. The Hp 2 allele is associated with increased MI size in individuals with DM. In vitro, the Hp 2 protein is associated with increased generation of oxidatively active iron, whereas the Hp 1 protein is associated with increased production of the antioxidant cytokine interleukin (IL)-10. METHODS Myocardial infarction was produced by myocardial ischemia-reperfusion (IR) in DM C57BL/6 mice carrying the Hp 1 or Hp 2 allele. Myocardial oxidative stress after IR was assessed using electrospray ionization mass spectrometry. Redox active iron and IL-10 were measured in the serum after IR. RESULTS Myocardial infarction size was significantly larger in Hp 2 mice as compared with Hp 1 mice (44.3 +/- 9.3% vs. 21.0 +/- 4.0%, p = 0.03), and these larger infarctions were associated with a significant increase in a panel of hydroxyl-eicosatetraenoic acids. Redox active iron was greater in Hp 2 mice (0.45 +/- 0.11 micromol/l vs. 0.14 +/- 0.05 micromol/l, p = 0.02), whereas IL-10 was greater in Hp 1 mice (85.8 +/- 12.9 pg/microl vs. 46.7 +/- 10.8 pg/microl, p = 0.04) after IR. Administration of an antioxidant (BXT-51072) to Hp 2 mice reduced myocardial injury after IR by more than 80% (p = 0.003), but no myocardial protection was provided by the antioxidant to Hp 1 mice. CONCLUSIONS The increased MI size in DM Hp 2 mice occurring after IR may be due to increased oxidative stress.
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Mechiakh R, Meriche F, Gheriani R, Bensaha R, Kremer R, Boudrioua A. Analysis of structural electrical and optical properties of sol–gel titanium oxide (TiO 2) thin films. Acta Crystallogr A 2006. [DOI: 10.1107/s0108767306095249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Kremer R, Barbato G, Castro L, Rista L, Rosés L, Herrera V, Neirotti V. Effect of sire breed, year, sex and weight on carcass characteristics of lambs. Small Rumin Res 2004. [DOI: 10.1016/j.smallrumres.2003.09.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Kremer R. Der Einfluss von soziodemografischen Merkmalen auf die Bewältigung funktionaler Selbständigkeit. AKTUELLE NEUROLOGIE 2003. [DOI: 10.1055/s-2003-39109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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von Schnering HG, Türck R, Hönle W, Peters K, Peters EM, Kremer R, Chang JH. CsMn2P2, ein Mangan(II, III)-phosphid mit der BaZn2P2-Struktur. Mit einem Beitrag zum BaAl4-Strukturtyp. Z Anorg Allg Chem 2002. [DOI: 10.1002/1521-3749(200212)628:12<2772::aid-zaac2772>3.0.co;2-g] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Urland W, Kremer R. Electron spin resonance spectra of low-symmetry rare-earth complexes: tetraphenylarsonium pentakis(nitrato)ytterbate(III). Inorg Chem 2002. [DOI: 10.1021/ic00179a017] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kremer R, Quednau K. Der Einfluss von Bewältigungsstrategien auf die „Aktivitäten des täglichen Lebens” - Eine Quer- und Längsschnittuntersuchung an Schlaganfallpatienten -. AKTUELLE NEUROLOGIE 2002. [DOI: 10.1055/s-2002-19997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Zimmerman DR, Reinhardt TA, Kremer R, Beitz DC, Reddy GS, Horst RL. Calcitroic acid is a major catabolic metabolite in the metabolism of 1 alpha-dihydroxyvitamin D(2). Arch Biochem Biophys 2001; 392:14-22. [PMID: 11469789 DOI: 10.1006/abbi.2001.2419] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Calcitroic acid (1 alpha-hydroxy-23 carboxy-24,25,26,27-tetranorvitamin D(3)) is known to be the major water-soluble metabolite produced during the deactivation of 1 alpha,25-dihydroxyvitamin D(3). This deactivation process involves a series of oxidation reactions at C(24) and C(23) leading to side-chain cleavage and, ultimately, formation of the calcitroic acid. Like 1 alpha,25-dihydroxyvitamin D(3), 1 alpha,25-dihydroxyvitamin D(2) is also known to undergo side-chain oxidation; however, to date there has been no evidence suggesting that 1 alpha,25-dihydroxyvitamin D(2) undergoes side-chain cleavage. To investigate this possibility, we studied 1 alpha,25-dihydroxyvitamin D(2) metabolism in HPK1A-ras cells as well as the well characterized perfused rat kidney system. Lipid and aqueous-soluble metabolites were prepared for characterization. Aqueous-soluble metabolites were subjected to reverse-phase HPLC analysis. The major aqueous-soluble metabolite from both the kidney and cell incubations comigrated with authentic calcitroic acid on two reverse-phase HPLC columns of different chemistry. The putative calcitroic acid from the cell and kidney incubations was methylated and found to comigrate with methylated authentic standard on straight-phase and reverse-phase HPLC columns. The identity of the methylated metabolite from cell incubations was also confirmed by mass spectral analysis. These data show, for the first time, that calcitroic acid is a major terminal product for the deactivation of 1 alpha,25-dihydroxyvitamin D(2). Intermediates leading to the formation of the calcitroic acid in the 1 alpha,25-dihydroxyvitamin D(2) metabolism pathway are currently being studied.
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Aruta C, Zegenhagen J, Cowie B, Balestrino G, Pasquini G, Medaglia P, Ricci F, Luebbert D, Baumbach T, Riedo E, Ortega L, Kremer R, Albrecht J. Structure of Superconducting [BaCuOx]2/[CaCuO2]n Superlattices on SrTiO3(001) Investigated by X-ray Scattering. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/1521-396x(200102)183:2<353::aid-pssa353>3.0.co;2-v] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Solomon C, Macoritto M, Gao XL, White JH, Kremer R. The unique tryptophan residue of the vitamin D receptor is critical for ligand binding and transcriptional activation. J Bone Miner Res 2001; 16:39-45. [PMID: 11149488 DOI: 10.1359/jbmr.2001.16.1.39] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The human vitamin D receptor (hVDR) is a member of the nuclear receptor superfamily of transcriptional regulators. Here we show that tryptophan 286 of the hVDR is critical for ligand binding and transactivation of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] target genes. Two mutants of the hVDR were produced, W286A and W286F, in which the tryptophan was replaced with an alanine or a phenylalanine, respectively. The W286A mutant did not bind 1,25(OH)2D3, interact with steroid receptor coactivator 1 (SRC-1) in vitro, or activate transcription. Moreover, the W286A receptor did not heterodimerize in a ligand-dependent manner with the human retinoid X receptor alpha (hRXRalpha). Although the W286F receptor heterodimerized with hRXRalpha, interacted with SRC-1, and bound 1,25(OH)2D3, its capacity to transactivate was attenuated severely. Thus, tryptophan 286 of hVDR plays an important role in specific 1,25(OH)2D3 ligand interaction and subsequently in hVDR/RXR interaction, SRC-1 binding, and ligand-dependent transactivation of 1,25(OH)2D3 target genes. These results identify the first amino acid that is absolutely required for ligand binding in the VDR and further define the structure-function relationship of 1,25(OH)2D3 interaction with its receptor.
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Solomon C, Kremer R, White JH, Rhim JS. Vitamin D resistance in RAS-transformed keratinocytes: mechanism and reversal strategies. Radiat Res 2001; 155:156-162. [PMID: 11121228 DOI: 10.1667/0033-7587(2001)155[0156:vdrirt]2.0.co;2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Human retinoid X receptor alpha (hRXRalpha) plays a critical role in DNA binding and transcriptional activity through its heterodimeric association with several members of the nuclear receptor superfamily, including the vitamin D receptor (VDR). Several cancer cell lines derived from different tissues have been shown to be resistant to the growth-inhibitory action of 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], the biologically active metabolite of vitamin D(3). Here we show that in RAS-transformed keratinocytes, Ser260 of hRXRalpha is phosphorylated through the RAS-RAF-MAP kinase cascade. This phosphorylation event results in the inhibition of vitamin D signaling via VDR/hRXRalpha heterodimers. Strategies to reverse this resistance include the use of the MAP kinase inhibitor, PD098059, and a non-phosphorylatable hRXRalpha mutant, Ala260, which completely abolishes RXR phosphorylation and restores the function of both 1,25(OH)(2)D(3) and a specific RXR ligand, LG1069 (4-[1-(5,6,7,8-tetrahydro-3,5,5,8,8-pentamethyl-2-naphtalenyl)ethenyl]-benzoic acid). In addition, we show that a vitamin D analog with low calcemic activity (EB1089) is more potent than 1,25(OH)(2)D(3) in inhibiting cancer cell growth in this system. Targeted therapy with selective analogs such as EB1089, in combination with the inhibition of phosphorylation of the RXR, could play a critical role in the development of strategies for cancer treatment.
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MESH Headings
- Cell Division/drug effects
- Cell Transformation, Neoplastic
- Dimerization
- Drug Resistance
- Genes, ras
- Humans
- Keratinocytes/drug effects
- Keratinocytes/enzymology
- Keratinocytes/metabolism
- MAP Kinase Signaling System/physiology
- Mitogen-Activated Protein Kinases/metabolism
- Phosphorylation
- Receptors, Calcitriol/genetics
- Receptors, Calcitriol/metabolism
- Receptors, Calcitriol/physiology
- Receptors, Cell Surface/metabolism
- Receptors, Cell Surface/physiology
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Cytoplasmic and Nuclear/physiology
- Receptors, Melatonin
- Signal Transduction/physiology
- Vitamin D/antagonists & inhibitors
- Vitamin D/pharmacology
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Goltzman D, White J, Kremer R. Studies of the effects of 1,25-dihydroxyvitamin D on skeletal and calcium homeostasis and on inhibition of tumor cell growth. J Steroid Biochem Mol Biol 2001; 76:43-7. [PMID: 11384862 DOI: 10.1016/s0960-0760(00)00146-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Vitamin D, parathyroid hormone (PTH), and parathyroid hormone-related peptide (PTHrP) are major regulators of calcium metabolism and vitamin D can also reduce the growth of normal cells and tumor cells. PTHrP and PTH act via a common membrane receptor (PTHR). The mouse PTHR is regulated by a kidney-selective upstream promoter P(1) and ubiquitous downstream promoter P(2). In vitro and in vivo 1,25(OH)(2)D can inhibit PTHR expression in bone but not cartilage by downregulating transcription via P(2). Gene transcription of PTHrP per se can also be downregulated by 1,25(OH)(2)D and by low calcemic vitamin D analogs. This inhibitory effect may reduce the hypercalcemia caused by overproduction of PTHrP by tumor cells. In a malignant keratinoctye cell line, phosphorylation of the retinoid X receptor alpha occurs through the activated Ras-MAP kinase pathway and results in attenuated trans-activation by the vitamin D receptor, its heterodimeric partner. This decreases the growth-inhibitory efficacy of 1,25(OH)(2)D. Studies of the capacity of vitamin D to alter PTHrP production and action and of its anti-proliferative effects can, therefore, shed important light on basic mechanisms controlling these events, and may also have major implications for clinical medicine and therapeutics.
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