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Biodistribution of Tc-99m-creatinine in rats with ablation nephropathy
(Springer, 2008) Lambrecht, Fatma Yurt; Soylu, Alper; Yilmaz, Osman; Durkan, Kubra; Kavukcu, Salih
Biological investigation of I-131-labeled new water soluble Ru(II) polypyridyl complex
(Pergamon-Elsevier Science Ltd, 2008) Ocakoglu, Kasim; Yildrim, Yeliz; Lambrecht, Fatma Yurt; Ocal, Jale; Icli, Siddik
New [Ru(L1)(dcbpy)(NCS)(2)] complex was synthesized in a one-pot reaction starting from [RuCl2(p-cymene)](2), where the ligands (dcbpy = 4,4'-dicarboxy-2,2'-bipyridine, L1 = dipyrido[3,2-a:2',3'-c]phenazine-11-ylcarbonyl) -sodium) are introduced sequentially. The resulting complex was characterized by IR, NMR, and elemental analysis. The complex was labeled with I-131. Biodistribution study of the complex was carried out using I-131-labeled [Ru(L1)(dcbpy)(NCS)(2)] complex. The biodistribution study performed with albino Wistar male rats has shown that the complex has high uptake in the lung, small intestine, fat, and spleen. (C) 2007 Elsevier Ltd. All rights reserved.
Design and synthesis of Tc-99m-citro-folate for use as a tumor-targeted radiopharmaceutical
(Elsevier Science Bv, 2010) Altiparmak, Burcu; Lambrecht, Fatma Yurt; Bayrak, Elif; Durkan, Kubra
Folate conjugates exhibit high affinity for folate receptor (FR) positive cells and tissues, such as those in tumors, making them attractive candidates and of interest in diagnostic tumor imaging. The aim of study was to synthesize a novel radiopharmaceutical based folate conjugate, Tc-99m-citro-folate, and to evaluate its efficiency as a targeted agent for imaging tumors that over express FR. TLC, HPLC H-1 NMR and LC-MS/MS methods were used to check and confirm the synthesized citro-folate. Citro-folate was labeled with Tc-99m with high labeling efficiency (97 +/- 1.0%). Biodistribution of the radiolabeled conjugate Tc-99m-citro-folate was investigated in vivo using two groups of rats: FR saturated and unsaturated. These experiments showed high uptake of Tc-99m-citro-folate in FR rich tissues and demonstrated its sensitivity and specificity in imaging ovary and uterus. Based on the demonstrated good radiolabeling and biodistribution properties, the compound Tc-99m-citro-folate may potentially be used as a radiopharmaceutical agent for imaging the FR-positive tumors. (C) 2010 Elsevier B.V. All rights reserved.
Design of radiolabeled gelatinase inhibitor peptide (Tc-99m-CLP) and evaluation in rats
(Pergamon-Elsevier Science Ltd, 2014) Altiparmak, Burcu; Lambrecht, Fatma Yurt; Citak, Asli
In malignant tissues, MMP-9 (gelatinase B, 92 kDa type IV collagenase) and MMP-2 (gelatinase A, 72 kDa type IV collagenase) are the most prevalent matrix metalloproteinases related to the tumor aggressiveness and metastatic potential. Since elevated levels of gelatinases are associated with poor prognosis in cancer patients, these enzymes are potential targets for tumor imaging to possibly predict metastases. In the present study, a cyclic decapeptide, CLP (Cys-Leu-Pro-Gly-His-Trp-Gly-Phe-Pro-Ser-Cys), was selected as a basic peptide because of its selective inhibitory activity toward gelatinases. The peptide was labelled with Tc-99m with a radiolabelling efficiency of 94.6 +/- 4.1%. After determining the appropriate conditions for radiolabelling, a biodistribution study of radiolabelled peptide in Albino Wistar rats was done. According to biodistribution data, Tc-99m-CLP showed high uptake in the lung, liver, uterus and spleen. The amount of normal tissue MMPs enzymes is known to be lower than a tumor tissue. In this connection, our findings show that matrix metalloproteinases inhibitory peptide which is CLP is labeled with Tc-99m with high yield and radiolabeled peptide might be might be utilized for the imaging of gelatinase activity due to overexpression of MMP-2 and MMP-9 in tumor tissue. (C) 2014 Elsevier Ltd. All rights reserved.
Design of Radiolabeled Gelatinase Inhibitor Peptide with for Imaging of Gelatinase Activity in Tumors
(Springer, 2012) Altiparmak, B.; Altiparmak, Burcu; Lambrecht, Fatma Yurt
Dual Nuclear/Fluorescence Imaging Potantial of Zinc(II) Phthalocyanine in MIA PaCa-2 Cell Line
(Bentham Science Publ Ltd, 2016) Lambrecht, Fatma Yurt; Ince, Mine; Er, Ozge; Ocakoglu, Kasim; Sari, Fatma Aslihan; Kayabasi, Cagla; Gunduz, Cumhur
Background and Objective: Pancreatic cancer is very common and difficult to diagnose in early stage. Imaging systems for diagnosing cancer have many disadvantages. However, combining different imaging modalities offers synergistic advantages. Optical imaging is the most multidirectional and widely used imaging modality in both clinical practice and research. Methods: In present study, Zinc(II) phthalocyanine [Zn(II) Pc] was synthesized, labeled with iodine-131 and in vitro study was carried out. The intracellular uptake studies of radiolabeled Zn(II) Pc were performed in WI-38 [ATCC CCL-75 (TM), tissue: human fibroblast lung] and MIA PaCa-2 [ATCC CRL-1420 (TM), tissue: human epithelial pancreas carcinoma] cell lines. Results: The intracellular uptake efficiency of radiolabeled Zn(II) Pc in MIA PaCa-2 cells was determined two times higher than WI-38 cells. Also, fluorescence imaging (FI) efficiency of synthesized Zn(II) Pc was investigated in MIA PaCa-2 cells and significant uptake was observed. Conclusion: Zn(II) Pc might be used as a new agent for dual fluorescence/nuclear imaging for pancreatic cancer.
Effect of adenine on bacterial translocation using technetium-99m labeled E. coli in an intestinal obstruction model in rats
(Springer, 2013) Oflaz, Ugur; Lambrecht, Fatma Yurt; Yilmaz, Osman; Pekcetin, Cetin
This study aims to investigate effects of adenine on bacterial translocation (BT) using Tc-99m-labeled E. coli in an intestinal obstruction rat model. In the study twenty-one rats were used. The rats were divided into three groups according to different feeding patterns. The control group (CG) was fed with a standard chow diet for 7 days. Group A1 and group A2 were fed with adenine supplemented chow diet for 7 days. At the end of the feeding period, after all groups was submitted intestinal obstruction. Tc-99m-E. coli was injected into the rats' terminal ileum under anesthetic. The rats were sacrificed under aseptic conditions at 24th h after the surgery. The uptake of Tc-99m-E. coli was determined in organs such as the liver, mesenteric lymph nodes, spleen and ileum. Group A1 and group A2 results show that the uptake of Tc-99m-E. coli decreased in the blood and organs comparing to the CG. As a result, it was observed that adenine reduced the level of BT when compared with CG. The beneficial effect of adenine on BT in intestinal obstruction was observed. However, further studies are needed to more clearly assess how this benefit can be achieved.
Effect of adenine on bacterial translocation using technetium-99m labeled E. coli in an intestinal obstruction model in rats
(Springer, 2013) Oflaz, Ugur; Lambrecht, Fatma Yurt; Yilmaz, Osman; Pekcetin, Cetin
This study aims to investigate effects of adenine on bacterial translocation (BT) using Tc-99m-labeled E. coli in an intestinal obstruction rat model. In the study twenty-one rats were used. The rats were divided into three groups according to different feeding patterns. The control group (CG) was fed with a standard chow diet for 7 days. Group A1 and group A2 were fed with adenine supplemented chow diet for 7 days. At the end of the feeding period, after all groups was submitted intestinal obstruction. Tc-99m-E. coli was injected into the rats' terminal ileum under anesthetic. The rats were sacrificed under aseptic conditions at 24th h after the surgery. The uptake of Tc-99m-E. coli was determined in organs such as the liver, mesenteric lymph nodes, spleen and ileum. Group A1 and group A2 results show that the uptake of Tc-99m-E. coli decreased in the blood and organs comparing to the CG. As a result, it was observed that adenine reduced the level of BT when compared with CG. The beneficial effect of adenine on BT in intestinal obstruction was observed. However, further studies are needed to more clearly assess how this benefit can be achieved.
Effect of adenine on bacterial translocation using Technetium-99m labeled E. Coli in an intestinal obstruction model in rats
(2013) Oflaz, U; Lambrecht, Fatma Yurt; Yılmaz, O; Pekçetin, Ç
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The effects of plasma immersion ion implantation and deposition (PIII&D) process voltages on the morphology, phase formation and E. coli adhesion of Ag coatings obtained on the surface of Ti6Al4V orthopedic implant material in nitrogen plasma
(Gazi Univ, Fac Engineering Architecture, 2017) Gencer, G. Mehmet; Karadeniz, Suleyman; Lambrecht, Fatma Yurt; Havitcioglu, Hasan; Ozkal, Sermin; Baskin, Huseyin
In order to combine the antimicrobial effect of silver with mechanical and chemical properties of titanium nitrate, Ag was deposited on the surface of Ti6Al4V (orthopedic implant material) in N-2 plasma by using plasma immersion ion implantation and deposition (PIII&D) method. The coatings were formed by using varied negative pulsed high voltage and magnetron sputtering voltage values of PIII&D process. Surface morphologies of coatings were determined with atomic force microscopy (AFM), while cross-section morphologies were determined with field emission scanning electron microscopy (FE-SEM). The phases and chemical compositions of coatings were investigated by using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. XPS depth profile analysis were done to reveal the penetration of Ag+ ions into the surface of specimen. In in vitro anti-bacterial effectiveness experiments, the adhesion of E. coli (Escherichia coli) microorganism, which were marked with Tc-99m radioisotope, on surfaces of specimens was investigated. It was consequently determined that Ag was dominant in the coatings obtained by applying 8 kV negative pulsed high voltage, while Ag decreased on the surface depending on the increase in the voltage.
Evaluation of 131I-Pentamidine for scintigraphy of experimentally Leishmania tropica infected hamsters
(2014) İnceboz, T; Lambrecht, Fatma Yurt; Eren, M Şencan; Girginkardeşler, N; Bekiş, R; Yılmaz, O; Er, O
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Evaluation of cancer imaging potential and photodynamic therapy efficacy of copper (II) benzyloxypheophorbide-a
(Taylor & Francis Ltd, 2015) Ocakoglu, Kasim; Er, Ozge; Lambrecht, Fatma Yurt; Susluer, Sunde Yilmaz; Kayabasi, Cagla; Gunduz, Cumhur; Yilmaz, Osman
The biological potential of a synthetic copper chlorophyll derivative was investigated via in vivo and in vitro experiments. The Cu-chlorophyll derivative photosensitizer (Cu-PH-A) was labeled with I-131 with high efficiency (92.9 +/- 4.2%) using the iodogen method. Cell culture studies were performed with the MCF-7 and MDAH-2774 cell lines after radiolabeling. The photosensitizing activity of Cu-PH-A was more effective in MDAH-2774 cells than in MCF-7 cells at a concentration of 50 mu M. When the biodistribution in female Albino Wistar rats was examined, uptake of the radiolabeled photosensitizer was maximal in the liver and ovaries after 60 min. It is concluded that radiolabeled Cu-chlorophyll derivative photosensitizer has high uptake in ovaries in normal rats. In addition, the intercellular uptake and PDT efficacy of the Cu-PH-A in MDAH-2774 were good compared with MCF-7 cells. This photosensitizer could be useful for both ovary tumour imaging and PDT.
Evaluation of I-131-Pentamidine for scintigraphy of experimentally Leishmania tropica-infected hamsters
(Informa Healthcare, 2014) Inceboz, Tonay; Lambrecht, Fatma Yurt; Eren, Mine Sencan; Girginkardesler, Nogay; Bekis, Recep; Yilmaz, Osman; Er, Ozge; Ozbilgin, Ahmet
We aimed to assess the ability of I-131-Pentamidine scintigraphy to detect the lesions of Leishmania tropica infection. An experimental model of cutaneous leishmaniasis was developed. The presence of cutaneous leishmaniasis was confirmed. Pentamidine was radioiodinated with I-131. The radiolabeled pentamidine was validated by the requisite quality control tests to check its radiolabeling efficiency, in vitro stability. I-131-Pentamidine (activity: 18.5 MBq/100 mu l) was injected intracardiacally into infected hamsters. Static whole body images of the hamsters were acquired under the gamma camera at 5 and 30 min, 2, 6 and 24 h following the administration. On the scintigrams, anatomically adjusted regions of interest (ROIs) were drawn over the right feet (target) and left feet (not-target) and various organs. Accumulation of I-131-Pentamidine at sites of infection is expressed as the target to non-target (T/NT) ratio. The results T/NT ratio decreased with time. In concluding the I-131-Pentamidine has poor sensitivity in detection of L. tropica infection.
Evaluation of nuclear imaging potential and photodynamic therapy efficacy of symmetrical and asymmetrical zinc phthalocyanines
(Elsevier Science Bv, 2016) Ocakoglu, Kasim; Er, Ozge; Ersoz, Onur Alp; Lambrecht, Fatma Yurt; Ince, Mine; Kayabasi, Cagla; Gunduz, Cumhur
Photodynamic therapy (PDT) is a medical treatment for the removal of target tissues involving the delivery of a photosensitizer agent followed by irradiation with visible light. In the present study, symmetric Zn(II)Pc 1 and asymmetrically substituted Zn(II)Pc 2 were synthesized and examined multifunctional agents for tumor nuclear imaging, and PDT potential. The Zn(II)Pc 1 and Zn(II)Pc 2 were radiolabeled with I-131 with high efficiency (93.4 +/- 1.6% and 91.4 +/- 1.6%, respectively). The results of the biodistribution study showed that radiolabeled Zn(II)Pc 1 had high uptake on lung, large intestine, ovary and pancreas. However, the uptake of radiolabeled Zn(II)Pc 2 was statically significant in pancreas and intestine. In PDT studies, EMT6/P (mouse mammary cell) and HeLa (cervical adenocarcinoma cell) with Zn(II)Pc 1 and Zn(II)Pc 2 were exposed to red light at the doses of 10-30 J/cm(2). Although PDT activity of Zn(II)Pc 2 in HeLa cell line was determined, Zn(II)Pc 1 showed no phototoxic effect in both cell lines. In conclusion, radiolabeled Zn(II)Pc 1 might be a promising imaging agent for the lung, the ovary pancreas, and the colon tumors. However, radiolabeled Zn(II)Pc 2 might be a promising nuclear imaging agent for the colon and the pancreas tumors and promising PDT agent for cervical tumors. (C) 2016 Elsevier B.V. All rights reserved.
Evaluation of Tc-99m-labeled antibiotics for infection detection
(Springer, 2011) Lambrecht, Fatma Yurt
One of the fields of research in nuclear medicine is the development of new radiopharmaceuticals for imaging infection and inflammation in humans. For this development, several antimicrobial peptides, antibiotics, antibiotic peptide and chemotactic peptides, etc., have been radiolabeled with different radionuclides (Ga-67, Tc-99m, In-111, F-18, I-131, etc.) and their imaging potentials studied. Actually, it is very important to distinguish between infection and inflammation. In this respect, radiolabeled antibiotics have advantages because many of the properties of the ideal infection-specific agent through antibiotics localizes in infection site. In this review, only Tc-99m-labeled antibiotics are evaluated and discussed.
Evaluation of Tc-99m-Pheophorbide-a use in infection imaging: A rat model
(Pergamon-Elsevier Science Ltd, 2011) Ocakoglu, Kasim; Bayrak, Elif; Onursal, Mehmet; Yilmaz, Osman; Lambrecht, Fatma Yurt; Holzwarth, Alfred R.
This study aims to prepare (99m)Technetium Pheophorbide-a (Tc-99m-PH-A) complex and evaluate its efficiency as an infection imaging agent. First, PH-A was obtained from Spirulina maxima algae, and the product compound was confirmed using H-1 NMR and MS (ESI) methods. The PH-A was then labeled with Tc-99m using the tin chloride method and its biological efficacy as a potential radiotracer for Staphylococcus aureus (S. aureus) infection was evaluated in bacterially infected and sterile inflamed rats. The radiochemical stability of the Tc-99m-PH-A in human serum was determined by thin-layer radiochromatography (TLRC). The radiochemical purity was 87 +/- 3.2% and remained constant at more than 80 +/- 0.1% even in serum for 120 min after radiolabeling. These experiments indicated that the ratio of Tc-99m-PH-A uptake in bacterially infected muscle, as compared to normal muscle, [target/non-target (T/NT)=5.6 at 1 h] was over four times higher than that in sterile inflamed muscle (T/NT=1.29 at 1 h). Disappearance of activity from the kidney and liver indicated that the urinary and hepatobiliary systems were the normal routes of excretion of the complex. (99m)Technetium Pheophorbide prepared with high yield is able to localize well in the bacterially infected muscle of the rats and Tc-99m-PH-A may be developed as a radiopharmaceutical agent to distinguish infection from inflammation by nuclear imaging. (C) 2011 Elsevier Ltd. All rights reserved.
Evaluation of the efficacy of Tc-99m-labeled ascorbic acid on common cold-cough drugs in rats
(Springer Birkhauser, 2007) Lambrecht, Fatma Yurt; Kayaalp, Erhan; Unak, Perihan; Enginar, Hueseyin; Muftuler, F. Zuemruet Biber; Medine, E. Ilker; Cetinkaya, Berkan
Multiple-drug therapy is common in current clinical practice. Because of this, people have been ready to embrace simplistic approaches to cold treatment, such as vitamin C and zinc. Ascorbic acid (vitamin C) is mostly administrated together with cough-cold drugs. The aim of this study was to investigate the effect of cough-cold drugs on the uptake of ascorbic acid using Tc-99m-ascorbic acid (Tc-99m-AA) in male albino Wistar rats. Ascorbic acid was labeled with Tc-99m and the distribution of Tc-99m-AA was investigated. The uptake of Tc-99m-AA was evaluated when administrated alone (group I), with chlorpheniramine maleate (CPR) (group II), with phenylpropanolamine hydrochloride (PPA) (group III), and with acetaminophen (APAP) (group IV). In some organs (apart from kidneys, intestinal system, and stomach) the uptake of Tc-99m-AA was not significantly affected by the administration of Tc-99m with CPR or Tc-99m with APAP at 120 min. On the other hand, there was significant difference in the uptake of Tc-99m-AA between groups I and III. The administration of Tc-99m-AA with PPA in rats caused an increase of the uptake of Tc-99m-AA at 120 min in the investigated organs compared to the administration of Tc-99m-AA alone. The present data show that vitamin C might be more effective for the treatment of common cold when coad-ministered with PPA compared to with CPR, with APAP, or alone.
Extraction, radiolabeling and in vivo biological evaluation of I-131 labeled egonol glycosides extract
(Walter De Gruyter Gmbh, 2015) Akgul, Yurdanur; Pazar, Erdinc; Yilmaz, Habibe; Lambrecht, Fatma Yurt; Yilmaz, Osman; Sanlier, Senay Hamarat
Crude extract of S. officinalis L. was found to have suspending agent, hemolytic, antitumor, antioxidant and antimicrobial activities. Its major components benzofurans and benzofuran glycosides have antifungal, anticancer, antibacterial and anticomplement activities and display acetylcholinesterase-cyclooxygenase inhibitory and cytotoxic properties. Recently, it has been reported that egonolgentiobioside is a valuable target for structural modification and warrants further investigation for its potential as a novel pharmaceutical tool for the prevention of estrogen deficiency induced diseases. The aim of the current study is to perform in vivo biological evaluation of a glycosides extract, which was isolated from the fruits endocarp of Styrax officinalis L, identified as egonolgentiobioside and homoegonolgentiobioside and labeled with I-131. The radiolabeled glycosides extract was labeled with I-131 with high yield. The labeled obtained radiolabeled compound was found to be quite stable and lipophilic. In order to determine its tissue distribution, an in vivo study was performed using healthy female Albino Wistar rats injected by I-131-glycosides. The biodistribution results showed that clearance of the radiolabeled compound is through the hepatobiliary pathway. The experimental study indicated that the radiolabeled glycosides extract accumulated in the large intestine. Therefore, the potential of I-131-glycosidesmight be evaluated in colon cancer cell lines and this might be a promising of tumor-imaging agent.
Extraction, radiolabeling and in vivo biological evaluation of I-131 labeled egonol glycosides extract
(Walter De Gruyter Gmbh, 2015) Akgul, Yurdanur; Pazar, Erdinc; Yilmaz, Habibe; Lambrecht, Fatma Yurt; Yilmaz, Osman; Sanlier, Senay Hamarat
Crude extract of S. officinalis L. was found to have suspending agent, hemolytic, antitumor, antioxidant and antimicrobial activities. Its major components benzofurans and benzofuran glycosides have antifungal, anticancer, antibacterial and anticomplement activities and display acetylcholinesterase-cyclooxygenase inhibitory and cytotoxic properties. Recently, it has been reported that egonolgentiobioside is a valuable target for structural modification and warrants further investigation for its potential as a novel pharmaceutical tool for the prevention of estrogen deficiency induced diseases. The aim of the current study is to perform in vivo biological evaluation of a glycosides extract, which was isolated from the fruits endocarp of Styrax officinalis L, identified as egonolgentiobioside and homoegonolgentiobioside and labeled with I-131. The radiolabeled glycosides extract was labeled with I-131 with high yield. The labeled obtained radiolabeled compound was found to be quite stable and lipophilic. In order to determine its tissue distribution, an in vivo study was performed using healthy female Albino Wistar rats injected by I-131-glycosides. The biodistribution results showed that clearance of the radiolabeled compound is through the hepatobiliary pathway. The experimental study indicated that the radiolabeled glycosides extract accumulated in the large intestine. Therefore, the potential of I-131-glycosidesmight be evaluated in colon cancer cell lines and this might be a promising of tumor-imaging agent.
Extraction, radiolabeling and in vivo biological evaluation of I-131 labeled egonol glycosides extract
(Walter De Gruyter Gmbh, 2015) Akgul, Yurdanur; Pazar, Erdinc; Yilmaz, Habibe; Lambrecht, Fatma Yurt; Yilmaz, Osman; Sanlier, Senay Hamarat
Crude extract of S. officinalis L. was found to have suspending agent, hemolytic, antitumor, antioxidant and antimicrobial activities. Its major components benzofurans and benzofuran glycosides have antifungal, anticancer, antibacterial and anticomplement activities and display acetylcholinesterase-cyclooxygenase inhibitory and cytotoxic properties. Recently, it has been reported that egonolgentiobioside is a valuable target for structural modification and warrants further investigation for its potential as a novel pharmaceutical tool for the prevention of estrogen deficiency induced diseases. The aim of the current study is to perform in vivo biological evaluation of a glycosides extract, which was isolated from the fruits endocarp of Styrax officinalis L, identified as egonolgentiobioside and homoegonolgentiobioside and labeled with I-131. The radiolabeled glycosides extract was labeled with I-131 with high yield. The labeled obtained radiolabeled compound was found to be quite stable and lipophilic. In order to determine its tissue distribution, an in vivo study was performed using healthy female Albino Wistar rats injected by I-131-glycosides. The biodistribution results showed that clearance of the radiolabeled compound is through the hepatobiliary pathway. The experimental study indicated that the radiolabeled glycosides extract accumulated in the large intestine. Therefore, the potential of I-131-glycosidesmight be evaluated in colon cancer cell lines and this might be a promising of tumor-imaging agent.

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