Research Outputs

Permanent URI for this communityhttps://hdl.handle.net/20.500.14288/2

Browse

Search Results

Now showing 1 - 10 of 446
  • Placeholder
    Publication
    18F-FDG PET/CT mean suv and metabolic tumor volume for mean survival time in non-small cell lung cancer
    (Lippincott Williams and Wilkins, 2015) Kurtipek, Ercan; Çaycı, Mustafa; Düzgün, Nuri; Esme, Hıdır; Terzi, Yüksel; Bakdık, Süleyman; Ünlü, Yaşar; Burnik, Cengiz; Bekçi, Taha Tahir; N/A; Aygün, Murat Serhat; Teaching Faculty; School of Medicine; Koç University Hospital; 291692
    Objective: The study was designed to determine the relationship between survival time of standardized uptake value (SUVmax and SUVmean) and metabolic tumor volume (MTV) in patients with non-small cell lung cancer (NSCLC), and examine the impact of demographic, clinical, and radiological data of these patients on survival. Materials and Methods: We performed a retrospective analysis of the records of 79 patients with NSCLC who presented to our hospital between May 2010 and March 2013, received a final diagnosis, and underwent 18F-FDG PET/CT for staging. Clinical, radiological, and 18F-FDG PET/CT parameters with an impact on prognosis such as the SUVmax of the primary tumor as calculated by the volumetric region of interest in the 18F-FDG PET/CT scans during initial diagnosis, mean SUV of the tumor, and MTV obtained with a threshold of SUVmax greater than 2.5 were recorded and statistically analyzed. A statistical analysis was carried out based on the clinical, radiological, and PET/CT findings of the patients who were divided into 2 groups: survivors and nonsurvivors. Results: Seventy patients (88.6%) were men, and 9 (11.4%) were women. The mean age was 63.65 ± 11.51 years in the nonsurvivor group (n = 40) versus 62.74 ± 10.60 years in the survivor group (n = 39) (Table 1). The mean survival time from diagnosis was 7.9 ± 6.52 months in the nonsurvivor group versus 14.09 ± 7.41 months in the survivor group. The mean survival time was 12.9 ± 7.9 months for those aged 60 or younger, whereas it was 9.9 ± 7.2 years for those aged 60 or older. According to the Cox regression analysis, higher MTV [relative risk (RR), 1.006; P = 0.03] and mean SUVmax (mSUV) (RR, 1.302; P = 0.03) had a significant impact on shortening of the mean survival time. However, no statistical significance was reached for SUVmax measurements (RR, 0.970; P = 0.39). Furthermore, there was a significant relationship between increased tumor size (andlt;2 cm, 2-4 cm, and ≥4 cm) and shortened mean survival time (P = 0.03). Conclusion: The present study showed that MTV and mSUV of FDG PET/CT scans of the tumor, but not SUVmax, had a significant impact on survival time of patients with NSCLC. Based on this result, we believe that we might have more accurate information about the survival time of our patients if we also evaluate mSUV and MTV in combination with mSUV, which is frequently used for diagnosis and monitoring of patients with NSCLC during our daily practice. © 2015 Wolters Kluwer Health, Inc. All rights reserved.
  • Placeholder
    Publication
    3D printed kombucha biomaterial as a tissue scaffold and L929 cell cytotoxicity assay
    (Wiley, 2024) Yanbakan, Edaguel; Tuncel, Tugba; Kocak Sezgin, Ayse; Bozoglan, Emirhan; Berikten, Derya; Kar, Fatih; Department of Molecular Biology and Genetics; Bağlan, İlkyaz; Department of Molecular Biology and Genetics; College of Sciences
    Tissue engineering includes the construction of tissue-organ scaffold. The advantage of three-dimensional scaffolds over two-dimensional scaffolds is that they provide homeostasis for a longer time. The microbial community in Symbiotic culture of bacteria and yeast (SCOBY) can be a source for kombucha (kombu tea) production. In this study, it was aimed to investigate the usage of SCOBY, which produces bacterial cellulose, as a biomaterial and 3D scaffold material. 3D printable biomaterial was obtained by partial hydrolysis of oolong tea and black tea kombucha biofilms. In order to investigate the usage of 3D kombucha biomaterial as a tissue scaffold, "L929 cell line 3D cell culture" was created and cell viability was tested in the biomaterial. At the end of the 21st day, black tea showed 51% and oolong tea 73% viability. The cytotoxicity of the materials prepared by lyophilizing oolong and black tea kombucha beverages in fibroblast cell culture was determined. Black tea IC50 value: 7.53 mg, oolong tea IC50 value is found as 6.05 mg. Fibroblast viability in 3D biomaterial + lyophilized oolong and black tea kombucha beverages, which were created using the amounts determined to these values, were investigated by cell culture Fibroblasts in lyophilized and 3D biomaterial showed viability of 58% in black tea and 78% in oolong tea at the end of the 7th day. In SEM analysis, it was concluded that fibroblast cells created adhesion to the biomaterial. 3D biomaterial from kombucha mushroom culture can be used as tissue scaffold and biomaterial.
  • Placeholder
    Publication
    A case of left testicular artery with high origin passing through a left renal vein fenestration
    (Via Medica Medical Publishers, 2024) Yılmaz, Ebru; Tatar, Cem; Keskin, Aleyna; Yalçın, Büşra; Gürses, İlke Ali; Graduate School of Health Sciences; School of Medicine
    Background: Fenestrations of are extremely rare in the venous system, especially renal veins. This paper aims to present a case of left renal vein fenestration where a high origin testicular artery passes through it. Materials and Methods The variation was observed incidentally in a 74-year-old Caucasian male cadaver during routine retroperitoneal dissections for second year medical students. Results: A fenestration in the mid portion of the left renal vein was observed. The length and height of the fenestration was 23 and 3.6 millimeters, respectively. The left testicular artery passed through the fenestration and followed a normal course distal to the fenestration. Posterior to the left renal vein, the testicular artery originated from the lateral aspect of abdominal aorta, just caudal to the left renal artery. On the right side, the testicular artery had a similar high origin, and two renal arteries were present. No venous variations were observed on the right side. Conclusions: The long course of the left renal vein is a factor of preference for donor kidney selection. Uncommon variations of the left renal veins, such as fenestrations, might result in a change in surgical technique and would put the left donor kidney at risk of prolonged anastomosis time and lower survival rates.
  • Placeholder
    Publication
    A common genetic variation of melanoma inhibitory activity-2 labels a subtype of pancreatic adenocarcinoma with high endoplasmic reticulum stress levels
    (Nature, 2015) Kong, Bo; Wu, Weiwei; Valkovska, Nataliya; Jäger, Carsten; Hong, Xin; Nitsche, Ulrich; Friess, Helmut; Esposito, Irene; Kleeff, Jörg; Michalski, Christoph W.; N/A; Erkan, Murat Mert; Faculty Member; School of Medicine; 214689
    HNF1 homeobox A (HNF1A)-mediated gene expression constitutes an essential component of the secretory pathway in the exocrine pancreas. Melanoma inhibitory activity 2 (MIA2), a protein facilitating protein secretion, is an HNF1A target. Protein secretion is precisely coordinated by the endoplasmic reticulum (ER) stress/unfolded protein response (UPR) system. Here, we demonstrate that HNFA and MIA2 are expressed in a subset of human PDAC tissues and that HNF1A induced MIA2 in vitro. We identified a common germline variant of MIA2 (c.A617G: p.I141M) associated with a secretory defect of the MIA2 protein in PDAC cells. Patients carrying MIA2I141M survived longer after tumor resection but the survival benefit was restricted to those patients who received adjuvant chemotherapy. The MIA2I141M variant was associated with high expression of ER stress/UPR genes – in particular those of the ERN1/XBP arm – in human PDAC samples. Accordingly, PDAC cell lines expressing the MIA2I141M variant expressed high levels of ERN1 and were more sensitive to gemcitabine. These findings define an interaction between the common MIA2I141M variant and the ER stress/UPR system and specify a subgroup of PDAC patients who are more likely to benefit from adjuvant chemotherapy. © 2015, Nature Research. All rights reserved.
  • Placeholder
    Publication
    A family from Turkey with congenital myasthenia and hereditary
    (Wiley, 2023) Tezen, D.; Gündüz, A.; Demirbilek, V.; Khojakulov, Zakhiriddin; Başak, Ayşe Nazlı; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); Graduate School of Health Sciences; School of Medicine
  • Placeholder
    Publication
    A fatal progeroid syndrome caused by a recessive RAF1 loss-of-function mutation
    (Springernature, 2023) Wong, Samantha; Tan, Yu Xuan; Tan, Kiat Yi; Loh, Abigail; Ozkan, Engin; Kayserili, Hülya; Reversade, Bruno; Beillard, Nathalie Sonia Escande; School of Medicine; Koç University Hospital
  • Placeholder
    Publication
    A late preterm infant with progressive respiratory distress
    (Marmara Univ, Fac Medicine, 2017) N/A; Gürsoy, Tuğba; Faculty Member; School of Medicine; Koç University Hospital; 214691
    A 2300 g female baby was born at 36+4 gestational age via caesarean section. Prenatal history was unremarkable. At 2 hours of age the baby was transferred to neonatal intensive care unit due to progressive respiratory distress and received poractant alfa as intubation-surfactant-extubation therapy after which FiO2 requirement decreased from 0.50 to 0.25. At 34 hours of age, while she was still on nasal continuous positive airway pressure (CPAP), she had sudden deterioration with retractions, desaturation and bradycardia. The infant was immediately intubated and put on high frequency oscillatory ventilation (HFOV) after which her oxygen saturations and heart rate stabilized.
  • Placeholder
    Publication
    A low cost training phantom model for radio-guided localization techniques in occult breast lesions
    (Wiley, 2015) Aydoğan, Fatih; Mallory, Melissa Anne; Tükenmez, Mustafa; Sagara, Yasuaki; Özturk, Erkan; Çelik, Varol; Akça, Tamer; Golshan, Mehra; N/A; İnce, Hüseyin Yavuz; Faculty Member; School of Medicine; N/A
    Radio-guided localization (RGL) for identifying occult breast lesions has been widely accepted as an alternative technique to other localization methods, including those using wire guidance. An appropriate phantom model would be an invaluable tool for practitioners interested in learning the technique of RGL prior to clinical application. The aim of this study was to devise an inexpensive and reproducible training phantom model for RGL. We developed a simple RGL phantom model imitating an occult breast lesion from inexpensive supplies including a pimento olive, a green pea and a Turkey breast. The phantom was constructed for a total cost of less than $20 and prepared in approximately 10 min. After the first model's construction, we constructed approximately 25 additional models and demonstrated that the model design was easily reproducible. The RGL phantom is a time- and cost-effective model that accurately simulates the RGL technique for non-palpable breast lesions. Future studies are warranted to further validate this model as an effective teaching tool. J. Surg. Oncol. 2015; 112:449-451. © 2015 Wiley Periodicals, Inc.
  • Placeholder
    Publication
    A multicenter, retrospective archive study of radiological and clinical features of ALK-positive non-small cell lung cancer patients and crizotinib efficacy
    (Lippincott Williams and Wilkins, 2024) Kilickap, Saadettin; Ozturk, Akin; Karadurmus, Nuri; Korkmaz, Taner; Cicin, Irfan; Paydas, Semra; Cilbir, Ebru; Sakalar, Teoman; Uysal, Mukremin; Yesil Cinkir, Havva; Uskent, Necdet; Demir, Necla; Sakin, Abdullah; Dursun, Oldac Uras; Aver, Birkan; Turhal, Nazim Serdar; Keskin, Serkan; Tural, Deniz; Eralp, Yesim; Bugdayci Basal, Fatma; Yasar, Hatime Arzu; Sendur, Mehmet Ali Nahit; Demirci, Umut; Cubukcu, Erdem; Karaagac, Mustafa; Cakar, Burcu; Tatli, Ali Murat; Yetisyigit, Tarkan; Urvay, Semiha; Gursoy, Pinar; Oyan, Basak; Turna, Zeynep Hande; Isikdogan, Abdurrahman; Olmez, Omer Fatih; Yazici, Ozan; Cabuk, Devrim; Seker, Mehmet Metin; Unal, Olcun Umit; Meydan, Nezih; Okutur, Sadi Kerem; Erman, Mustafa; Yumuk, Perran Fulden; Tunalı, Didem; School of Medicine
    To evaluate radiological and clinical features in metastatic anaplastic lymphoma kinase+ non-small cell lung cancer patients and crizotinib efficacy in different lines. This national, non-interventional, multicenter, retrospective archive screening study evaluated demographic, clinical, and radiological imaging features, and treatment approaches in patients treated between 2013-2017. Totally 367 patients (54.8% males, median age at diagnosis 54 years) were included. Of them, 45.4% were smokers, and 8.7% had a family history of lung cancer. On radiological findings, 55.9% of the tumors were located peripherally, 7.7% of the patients had cavitary lesions, and 42.9% presented with pleural effusion. Pleural effusion was higher in nonsmokers than in smokers (37.3% vs. 25.3%, P = .018). About 47.4% of cases developed distant metastases during treatment, most frequently to the brain (26.2%). Chemotherapy was the first line treatment in 55.0%. Objective response rate was 61.9% (complete response: 7.6%; partial response: 54.2%). The highest complete and partial response rates were observed in patients who received crizotinib as the 2nd line treatment. The median progression-free survival was 14 months (standard error: 1.4, 95% confidence interval: 11.2-16.8 months). Crizotinib treatment lines yielded similar progression-free survival (P = .078). The most frequent treatment-related adverse event was fatigue (14.7%). Adrenal gland metastasis was significantly higher in males and smokers, and pleural involvement and effusion were significantly higher in nonsmokers-a novel finding that has not been reported previously. The radiological and histological characteristics were consistent with the literature data, but several differences in clinical characteristics might be related to population characteristics.
  • Placeholder
    Publication
    A new option for the reconstruction of orbital floor defects with heterologous cortical bone
    (Churchill Livingstone, 2015) Ozel, Bora; Findikcioglu, Kemal; Guney, Kirdar; Barut, Ismail; Ozmen, Selahattin; N/A; Sezgin, Billur; Faculty Member; School of Medicine; 133762
    Background: The orbital floor is one of the most frequently injured areas of the maxillofacial skeleton during facial trauma. A retrospective analysis of patients who have undergone treatment of orbital floor fractures with heterologous cortical bone is presented. Methods: This retrospective study was carried out with 21 patients over a period of 4 years between 2010 and 2014. All patients with a traumatic orbital floor defect who underwent reconstruction with heterologous cortical bone were included. The operations were carried out under general anesthesia for all patients. A subciliary incision was used in 20 patients and an infraorbital approach was used in one patient. All patients underwent follow-up examinations clinically as well as radiologically, at 1, 3, 6 and 12 months postoperatively. Computed tomographic scans were taken at the postoperative 6th month, and at the first postoperative year if needed. Results: Preoperatively, the physical examination revealed diplopia in 17 patients (80.9%), gaze restriction in 14 patients (66.6%), enophthalmos in six patients (28.5%), and infraorbital nerve paresthesia in two patients (9.5%). None of the patients showed impaired visual acuity preoperatively or postoperatively. Diplopia and gaze restriction resolved postoperatively in all of the patients. All patients had a negative intraoperative forced duction test demonstrating free globe movement. Enophthalmos showed complete resolution in the postoperative period. In one of the two patients with preoperative infraorbital nerve paresthesia, this resolved at the postoperative fifth month. Scleral show appeared in six patients but resolved completely within 3-8 weeks with massage. There was no graft extrusion, resorption or displacement during the follow-up period. Conclusions: Tecnoss Semi Soft Lamina is a good alternative for the reconstruction of blowout fractures due to its plasticity and biocompatible structure. Without donor site morbidity, it is a safe and appropriate heterologous bone graft material for maxillofacial applications such as orbital floor reconstruction. We cannot recommend its use for near-total, wide orbital floor defects as it may not provide enough support in such circumstances.