Researcher:
Kulaç, İbrahim

Profile Picture
ORCID

Job Title

Faculty Member

First Name

İbrahim

Last Name

Kulaç

Name

Name Variants

Kulaç, İbrahim

Email Address

Birth Date

Filters

2019 - 201932020 - 202318

Advanced Search

Filter by

Settings

Researcher Of Publications: search.filters.isAuthorOfPublication.7415cf93-0d20-4a8b-a6ac-357dcae30168

Search Results

Now showing 1 - 10 of 22
  • Placeholder
    PublicationMetadata only
    The past, present, and future statuses of formerly classified "atypical pituitary adenomas": a clinicopathological assessment of 101 cases in a cohort of more than 1,000 pure endoscopically treated patients in single center
    (Thieme Medical Publ Inc, 2021) Bal, Ercan; Ayhan, Selim; Soylemezoglu, Figen; Berker, Mustafa; N/A; Kulaç, İbrahim; Faculty Member; School of Medicine; Koç University Hospital; 170305
    Objective This study was aimed to assess the clinical aggressiveness of pituitary neoplasms that were previously defined as atypical adenomas. Methods A total of 1,042 pituitary adenomas were included in the study and 101 of them were diagnosed as atypical adenoma. Demographic characteristics, radiological evaluations, and clinical information were obtained from a computer-based patient database. Cases were categorized as atypical or typical using the criteria listed in 2004 Classification of Tumors of Endocrine Organs. Results The cure and reoperation rates did not show any statistically significant difference between the typical and atypical adenomas. However, a higher K (i) -67 labeling index was found to be associated with a higher rate of reoperation ( p =0.008) in atypical adenomas. of note, cavernous sinus invasion or parasellar extension was found to be associated with lower cure rates in patients with atypical pituitary adenomas ( p <0.001 and p =0.001, respectively). Conclusion Although atypical pituitary adenomas are known to be more invasive, this study demonstrated that the reoperation and cure rates are the same for typical and atypical adenomas. Our findings advocate for omitting the use of atypical adenoma terminology based solely on pathological evaluation. As stated in the 4th edition of the World Health Organization (WHO) classification, accurate tumor subtyping, evaluation of proliferation by means of mitotic count and K (i) -67 labeling index, and radiological and intraoperative assessments of tumor invasion should be taken into consideration in the management of such neoplasms.
  • Placeholder
    PublicationMetadata only
    Fluorescence-guided extended pelvic lymphadenectomy during robotic radical prostatectomy
    (Springernature) N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; Özkan, Arif; Köseoğlu, Ersin; Canda, Abdullah Erdem; Çil, Barbaros Erhan; Aykanat, İbrahim Can; Sarıkaya, Ahmet Furkan; Tarım, Kayhan; Armutlu, Ayşe; Kulaç, İbrahim; Barçın, Erinç; Falay, Fikri Okan; Kordan, Yakup; Baydar, Dilek Ertoy; Balbay, Mevlana Derya; Esen, Tarık; Doctor; Faculty Member; Faculty Member; Faculty Member; Doctor; Researcher; Researcher; Teaching Faculty; Faculty Member; Undergraduate Student; Teaching Faculty; Faculty Member; Faculty Member; Faculty Member; Faculty Member; N/A; School of Medicine; School of Medicine; School of Medicine; N/A; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; Koç University Hospital; N/A; N/A; N/A; Koç University Hospital; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; 350876; 116202; 169993; N/A; 327615; 327605; 133567; 170305; N/A; 246484; 157552; 8025; 153320; 50536
    We evaluated and described the impact of prostatic indocyanine green (ICG) injection on extended pelvic lymph node (LN) dissection (ePLND) in robotic-assisted radical prostatectomy (RARP). Between January 2019 and December 2021, we included consecutive 50 PCa patients who underwent ePLND during RARP with (n = 25) or without (n = 25) prostatic ICG injection. ICG injection was performed during abdominal port placement and robot docking. Pelvic LNs reflecting green color were initially excised and then the template was completed. The outcomes of two groups were compared. Overall, nine (36%) and five (20%) of the patients had metastatic LN involvement in the ICG and non-ICG groups, respectively. Of the 509 dissected LNs in the ICG group, 122 (23.9%) were fluorescence active. 20 LNs (3.9%) were metastatic in this group, 9 (45%) of which were ICG+. 408 LNs were resected on the non-ICG group with 8(1.9%) being metastatic. Eight (88.9%) of nine pN+ patients were florescent positive in the ICG group. Out of six patients with pN+ disease, Ga68 PSMA-PET/CT detected positive LNs preoperatively. In addition to preoperative Ga68 PSMA-PET/CT investigation, ICG-guided ePLND might increase identification and removal of metastatic LNs duirng RARP. Improvements in staging and oncologic outcomes may also be seen in intermediate- and high-risk patients.
  • Placeholder
    PublicationMetadata only
    Senior moments are never-ending times when you are old (are they?): first step of turquoise project
    (Türk Nöropsikiyatri Derneği, 2022) Oz, Didem; Yildirim, Zerrin; Kiyi, Ilayda; Ozbek, Yagmur; Gurvit, Ibrahim Hakan; Yener, Gorsev; N/A; Kulaç, İbrahim; Tihan, Tarık; Erkol, Gökhan; Faculty Member; Other; Doctor; School of Medicine; School of Medicine; N/A; N/A; N/A; Koç University Hospital; 170305; 307927; N/A
    Introduction: The number of dementia patients is increasing in Turkey,, as well as all over the world. However, we do not know how much the society knows about dementia. The aim of this study is to evaluate people's concept of dementia, their awareness of dementia research and treatment, whether dementia and forgetfulness are considered normal in old age, and whether having dementia is associated with a lack of mental abilities. Methods: A Dementia Awareness Questionnaire was created in the form of a self-report questionnaire, consisting of 20 questions and using a five-point Likert-type answering method in order to question participants' information about dementia. In addition, we asked for demographic information such as age, gender, occupation, education level of the participants, as well as whether they have had relatives diagnosed with a neurodegenerative disease. The surveys were administered online. Results: A total of 1551 participants from 53 cities were included in the study. Approximately half of the participants did not know the definition of dementia, 20.9% thought that dementia and Alzheimer's disease were the same; 50.4% considered forgetfulness, and 55.2% considered dementia as a natural consequence of aging. While 34.5% of the participants thought that dementia patients could be dangerous, 10.3% thought they could not continue living as a part of society. While 38.5% of healthcare professionals do not know the definition of dementia, 18.5% of them say that dementia and Alzheimer's disease are the same, 58.5% think that dementia patients are not fit to make their own decisions, 40.6% believe that dementia patients have criminal liability. 15.8% of healthcare professionals thought that dementia is only seen in elderly people; 21.4% thought that dementia, and 49.2% thought that forgetfulness was a result of normal aging. Conclusion: Our study confirms that dementia is still an unknown concept in society and among healthcare professionals. It is widely believed that forgetfulness and dementia are part of normal aging, and there is no cure for dementia. This study, which we have done in order to understand the level of dementia awareness in Turkish society, reveals the necessity for research on dementia and studies on how to increase dementia awareness.
  • Placeholder
    PublicationMetadata only
    High extratumoral mast cell counts are associated with a higher risk of adverse prostate cancer outcomes
    (American Association for Cancer Research Inc., 2020) Sullivan, Heidi Hempel; Heaphy, Christopher M.; Cuka, Nathan; Lu, Jiayun; Barber, John R.; de Marzo, Angelo M.; Lotan, Tamara L.; Joshu, Corinne E.; Sfanos, Karen S.; N/A; Kulaç, İbrahim; Faculty Member; School of Medicine; 170305
    Background: Given our previous findings that low intratumoral and high extratumoral mast cell numbers are associated with higher risk of biochemical recurrence after radical prostatectomy, we now assessed this relationship with race and the development of metastases. Methods: We stained for mast cell tryptase via IHC and fluorescent immunolabeling in 885 men across multiple tissue microarray sets designed to assess biomarkers in association with race and prostate cancer outcomes (median follow-up, 7.0 years). Results: Intratumoral and extratumoral mast cell counts were significantly lower in tissues from African-American compared with European-American men, but not within strata of cancer grade. There was no association between mast cell counts and ERG positivity, PTEN loss, or TP53 missense mutation. Higher minimum extratumoral mast cells were associated with an increased risk of biochemical recurrence [comparing highest with lowest tertiles: HR, 1.61; 95% confidence interval (CI), 1.12-2.29; P trend ¼ 0.01]; this pattern was similar among European-American and African-American men and by grade of disease. There was no significant association between minimum intratumoral mast cell count and biochemical recurrence, overall or within strata of race and grade. Finally, high minimum number of extratumoral mast cells was associated with prostate cancer metastases (comparing highest with lowest tertiles: HR, 2.12; 95% CI, 1.24-3.63; P trend ¼ 0.01). Conclusions: High extratumoral mast cell numbers are associated with biochemical recurrence and the development of metastases after radical prostatectomy. Impact: Higher numbers of benign tissue mast cells are associated with a higher risk of adverse outcomes after radical prostatectomy, including metastatic prostate cancer.
  • Placeholder
    PublicationMetadata only
    Pilomyxoid astrocytomas: a short review
    (Springer Japan Kk, 2019) Tihan, Tarık; N/A; Kulaç, İbrahim; Faculty Member; School of Medicine; 170305
    Pilomyxoid astrocytoma is a variant of pilocytic astrocytoma and the clinical, histological and molecular data point to a very close relationship as well as a more aggressive biological behavior for the former. WHO 2016 classification does not provide a specific grade for these neoplasms, but there is sufficient evidence in the literature that pilomyxoid astrocytoma has slightly worse prognosis than typical pilocytic astrocytoma. There is increasing evidence that in addition to the MAPK pathway alterations, pilomyxoid astrocytomas harbor genetic alterations that distinguish them from typical pilocytic astrocytoma
  • Placeholder
    PublicationMetadata only
    Molecular pathology of prostate cancer
    (2021) Roudier, Martine P.; Haffner, Michael C.; N/A; Kulaç, İbrahim; Faculty Member; School of Medicine; 170305
    N/A
  • Placeholder
    PublicationMetadata only
    Reproducibility of morphologic parameters of the international endocervical adenocarcinoma criteria and classification system and correlation with clinicopathologic parameters: a multi-institutional study
    (Lippincott Williams and Wilkins, 2022) Erdem, Özlem; Zeren, Emine Handan; Haberal, Nihan; Özen, Özlem; Ayhan, Ali; N/A; N/A; N/A; N/A; N/A; Bulutay, Pınar; Kulaç, İbrahim; Taşkıran, Çağatay; Vatansever, Doğan; Kapucuoğlu, Fatma Nilgün; Teaching Faculty; Faculty Member; Faculty Member; Faculty Member; Faculty Member; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; 133565; 170305; 134190; 193687; 7421
    Endocervical adenocarcinomas (ECAs) have been recently reclassified according to their morphologic features linked to etiology by the International Endocervical Adenocarcinoma Criteria and Classification (IECC) and this system is adopted by WHO 2020. This classification separates the ECAs as human papillomavirus (HPV)-associated (HPVA) and HPV-independent (HPVI) subtypes. According to WHO 2020, high risk (HR)-HPV association can be histologically recognized by the presence of luminal mitoses and apoptosis. Therefore, investigating the reproducibility of the morphologic criteria of this new classification will be important in observing the recognizability of tumor types. Full slide sets of 94 ECAs were collected from 4 institutions in Turkey and reclassified on the basis of IECC/WHO 2020 criteria and the presence or absence of HR-HPV. HR-HPV presence was confirmed by HPV DNA in situ hybridization, p16 immunohistochemistry and in conflicted cases with real time-polymerase chain reaction. The final diagnoses were given based on the combination of the histologic evaluation and ancillary test results. Our cohort consisted of 73.4% HPVA and 26.6% HPVI cases. According to the WHO 2020 criteria 92.7% of HPVAs and 88% of HPVIs were easily classified. HPV DNA in situ hybridization was positive in 91.3% of the HPVAs and p16 was positive in all HPVAs, and also positive in 8% of the HPVIs. In conclusion, most of the ECAs can be diagnosed by their characteristic morphologic features by the WHO 2020 criteria. However, we want to emphasize that mitosis/apoptosis criteria may not be helpful especially in mucinous ECAs and ancillary tests for HR-HPV should be used in challenging cases.
  • Placeholder
    PublicationMetadata only
    Comparative analysis of autophagy in drug responses and aggressive behavior of adult versus pediatric glioma cell lines
    (Wiley, 2022) Aygun, Bera; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; Yenidoğan, İrem; Peker, Nesibe; Deveci, Gamze; Kırmızı, Döndü; Asarcıklı, Fikret; Sözmen, Banu Oflaz; Akyoldaş, Göktuğ; Kulaç, İbrahim; Solaroğlu, İhsan; Erbey, Mehmet Fatih; Gözüaçık, Devrim; Researcher; Researcher; PhD Student; Other; Doctor; Faculty Member; Faculty Member; Faculty Member; Faculty Member; Faculty Member; Faculty Member; N/A; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; School of Medicine; N/A; Graduate School of Health Sciences; N/A; N/A; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; N/A; N/A; N/A; N/A; Koç University Hospital; N/A; N/A; N/A; N/A; N/A; 327591; N/A; N/A; N/A; N/A; 198711; 203677; 102059; 206213; 40248
    Central nervous system tumors are the most common solid cancer and a leading cause of cancer-related deaths in children. Glioma is the most challenging pediatric CNS tumor with therapy resistance and poor prognosis in pediatric patients. Although histopathological analyses revealed similarities with adult brain glioma, emerging evidence suggests that the deregulated molecular pathways in pediatric glioma (p-GM) are different from that of adults. Autophagy, a cellular clearance system and a drug resistance mechanism, has been implicated in glioma progression, invasion, and relapse, yet its role in pediatric patients is not well documented. In this study, we compared the autophagic capacity of adult versus p-GM cell lines and evaluated the effect of autophagy manipulation on drug responses. In addition, migration, extracellular matrix invasion ability, and the metabolism of pediatric and adult gliomas were compared and the contribution of autophagy to the aggressive phenotype was evaluated.
  • Placeholder
    PublicationMetadata only
    [Ga-68]Ga-PSMA-11 and [F-18]FDG uptake of venous tumor thrombus in inferior vena cava and left common iliac vein from prostate cancer on positron emission tomography
    (Springer, 2023) Kabaoğlu, Zeynep Ünal; N/A; Seymen, Hülya; Esen, Barış; Kulaç, İbrahim; Aksoy, Murat; Demirkol, Mehmet Onur; Kordan, Yakup; Teaching Faculty; Teaching Faculty; Faculty Member; Other; Faculty Member; Faculty Member; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; 350778; 199167; 170305; N/A; 196946; 157552
    N/A
  • Placeholder
    PublicationMetadata only
    Machine learning-based approach to identify formalin-fixed paraffin-embedded glioblastoma and healthy brain tissues
    (Spie-Int Soc Optical Engineering, 2022) N/A; Department of Electrical and Electronics Engineering; N/A; N/A; N/A; N/A; N/A; Department of Electrical and Electronics Engineering; Torun, Hülya; Batur, Numan; Bilgin, Buse; Esengür, Ömer Tarık; Baysal, Kemal; Kulaç, İbrahim; Solaroğlu, İhsan; Onbaşlı, Mehmet Cengiz; PhD Student; Undergraduate Student; PhD Student; Undergraduate Student; Faculty Member; Faculty Member; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; Graduate School of Sciences and Engineering; School of Medicine; School of Medicine; School of Medicine; School of Medicine; College of Engineering; N/A; N/A; N/A; N/A; 119184; 170305; 102059; 258783
    Glioblastoma is the most malignant and common high-grade brain tumor with a 14-month overall survival length. According to recent World Health Organization Central Nervous System tumor classification (2021), the diagnosis of glioblastoma requires extensive molecular genetic tests in addition to the traditional histopathological analysis of Formalin-Fixed Paraffin-Embedded (FFPE) tissues. Time-consuming and expensive molecular tests as well as the need for clinical neuropathology expertise are the challenges in the diagnosis of glioblastoma. Hence, an automated and rapid analytical detection technique for identifying brain tumors from healthy tissues is needed to aid pathologists in achieving an error-free diagnosis of glioblastoma in clinics. Here, we report on our clinical test results of Raman spectroscopy and machine learning-based glioblastoma identification methodology for a cohort of 20 glioblastoma and 18 white matter tissue samples. We used Raman spectroscopy to distinguish FFPE glioblastoma and white matter tissues applying our previously reported protocols about optimized FFPE sample preparation and Raman measurement parameters. One may analyze the composition and identify the subtype of brain tumors using Raman spectroscopy since this technique yields detailed molecule-specific information from tissues. We measured and classified the Raman spectra of neoplastic and non-neoplastic tissue sections using machine learning classifiers including support vector machine and random forest with 86.6% and 83.3% accuracies, respectively. These proof-of-concept results demonstrate that this technique might be eventually used in the clinics to assist pathologists once validated with a larger and more diverse glioblastoma cohort and improved detection accuracies.