Ulas Kumbasar

Dr. Ulas Kumbasar


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2022 in TURKISH JOURNAL OF MEDICAL SCIENCES
Verified
Journal Article
Open access
PDF file
BABurcu Ancin
Burcu Ancin
MÖMesut Meli̇h Özercan
Mesut Meli̇h Özercan
YYYi̇ğİt Yilmaz
Yi̇ğİt Yilmaz
SUSerkan Uysal
Serkan Uysal
UKUlas Kumbasar
Ulas Kumbasar
MDMeti̇n Demi̇rCi̇n
Meti̇n Demi̇rCi̇n
Background/aim: Significant advances have been achieved in immunotherapy for the treatment of lung cancer. It is known that tumor cells and cells in the tumor microenvironment express high amounts of programmed cell death ligand 1 (PD-L1). These PD-L1s interact with programmed cell death protein 1 (PD-1), causing immunosuppression. The aim of our study is to examine the correlation between the serum sPD-1 and sPD-L1 levels and clinicopathological characteristics in patients with nonsmall cell lung cancer. We also compared our results with the healthy population (control group). Materials and methods: Thirthy-seven nonsmall cell lung cancer (NSCLC) patients who were operated in our clinic were included in our study. The control group included fifteen healthy patients. The sPD-1 and sPD-L1 levels were measured in serum samples by using the ELISA method. Results: The preoperative sPD-1 and sPD-L1 levels were significantly higher in the study group compared to the control group (44.12 ± 22.25 pg/mL vs. 18.54 ± 6.56 pg/mL; p = 0.001 and 26.15 ± 18.03 pg/mL vs. 10.29 ± 3.08 pg/mL; p = 0.001, respectively). There was a statistically significant decline in serum sPD-1 and sPD-L1 levels at the preoperative and postoperative 1st, 7th, and 30th days following surgical resection (44.12 ± 22.25 pg/mL, 37.86 ± 18.02 pg/mL, 36.33 ± 18.36 pg/mL, 34.14 ± 13.71 pg/mL; p = 0.007 and 26.15 ± 18.03 pg/mL, 20.60 ± 15.50 pg/mL, 18.31 ± 14.04 pg/mL, 13.64 ± 10.60 pg/mL; p = 0.001, respectively).There was a positive correlation between the preoperative and postoperative 30th day serum sPD-1 levels and the tumor size (p = 0.031, r = 0.352; p = 0.024, r = 0.371; respectively). We also found a positive correlation between the preoperative and postoperative 30th day serum sPD-L1 levels and pleural invasion (p = 0.001, p = 0.001; respectively), and the N category (p = 0.015, p = 0.013; respectively). Conclusion: We think that sPD-1 and sPD-L1 levels may be used as a potential biomarker for lung cancer screening, prediction of the stage, and besides to detect recurrences and/or metastases following resection in NSCLC following validation with multicenter and larger-scale prospective trials.

25 October 2018 in The Turkish Journal of Pediatrics
Verified
Journal Article
Open access
UKUlas Kumbasar
Ulas Kumbasar
EAEbru Aypar
Ebru Aypar
TKTevfik Karagöz
Tevfik Karagöz
MDMetin Demircin
Metin Demircin
RDRıza Doğan
Rıza Doğan
Chronic thromboembolic pulmonary hypertension (CTEPH), which occurs due to impartial resolution of the pulmonary thrombus, is a rare type of pulmonary hypertension. However, most patients have an excellent long-term survival following pulmonary thromboendarterectomy (PTE). Pulmonary emboli and associated CTEPH is unusual in the pediatric population and is mostly reveals an underlying thrombophilic state. PTE is also recognized as the best therapeutic option in this subgroup of patients. In this case series, we report three young patients who had successfully undergone PTE due to pulmonary emboli and associated CTEPH.

31 January 2018 in Turkish Journal of Thoracic and Cardiovascular Surgery
Verified
Journal Article
Closed access
UKUlas Kumbasar
Ulas Kumbasar
HDHarun Demirci
Harun Demirci
GEGökçen Emmez
Gökçen Emmez
ZYZuhal Yıldırım
Zuhal Yıldırım
IGİpek Işık Gönül
İpek Işık Gönül
MKMemduh Kaymaz
Memduh Kaymaz
This study aims to investigate whether preconditioning with alpha-lipoic acid has any protective effect in neuronal damage in an experimental spinal cord ischemia-reperfusion injury model. Eighteen adult male New Zealand rabbits (2.4-3.5 kg) were equally divided into sham, control and treatment groups. The abdominal aorta was occluded for 30 min proximally 1 cm below the renal artery and distally 1 cm above the bifurcation using aneurysm clips in control and treatment groups. Treatment group received intraperitoneal 100 mg/kg lipoic acid 20 min before aortic cross-clamping. The animals were sacrificed 48 hours after the operation and spinal cord segments between L2 and L5 were removed for biochemical and histopathological analysis. Levels of glutathione, malondialdehyde, total nitrate/nitrite, advanced oxidation protein products, catalase, superoxide dismutase, and glutathione peroxidase were examined in spinal cord. Preconditioning with alpha-lipoic acid demonstrated significantly favorable effects in all measured parameters of oxidative stress. Histopathological evaluation of the tissues also demonstrated significantly decreased neuronal degeneration, axonal damage, and microglial and astrocytic infiltration in the treatment group compared to the control group. The results of this study indicate that alpha-lipoic acid administration before aortic cross-clamping has significant neuroprotective effect on spinal cord injury in rabbits.

1 December 2020 in Indian Journal of Medical Research
Verified
Journal Article
Open access
HTHale Hatice Temel
Hale Hatice Temel
UKUlas Kumbasar
Ulas Kumbasar
EBEsra Büber
Esra Büber
YAYasemin Aksoy
Yasemin Aksoy
SCSabanur Cavdar
Sabanur Cavdar
IPİlHan Pasaoglu
İlHan Pasaoglu
Background & objectives: Oxidative stress can cause many diseases and increases the risk of post-operative complications in children with congenital heart disease. For these reasons, this study was aimed to investigate the differences between cyanotic and acyanotic paediatric patients who underwent heart surgery with markers of oxidative stress. Methods: Eighty five patients were included in the study. The samples taken before the surgery and within the first 24 h after the surgery were evaluated for haemoglobin (Hb), leukocytes, uric acid, glutathione (GSH), malondialdehyde and total antioxidant capacity. Cyanotic, acyanotic, hyperoxygenated, normo-oxygenated, cardiac surgery with or without cardiopulmonary bypass (CPB) comparisons were made. Results: Positive correlation was found between age and pre-operative total antioxidant status values. Cyanotic and acyanotic patients did not have different antioxidant reserve capacities preoperatively. Although pre-operative thiobarbituric acid reactive substances (TBARS) levels were significantly lower in cyanotic patients, post-operative levels were higher. TBARS levels increased and GSH levels reduced postoperatively. The level of oxygenation did not cause a significant difference on markers of oxidative stress. The duration of CPB did not have negative effects on oxidative stress. Interpretation & conclusions: Cyanotic and younger patients were found to be more vulnerable to oxidative stress. The increased levels of TBARS and the decreased levels of GSH could be the indicators of oxidative damage depending on many factors such as surgery, CPB, ischaemia/reperfusion, inflammation, iron overload and oxygenation. The level of oxygenation does not cause a noticeable difference in oxidative stress. CPB causes oxidative stress, but if it is conducted appropriately, the duration of CPB does not cause a significant negative impact on oxidative stress.

28 April 2024 in Annals of Surgical Oncology
Verified
Journal Article
Open access
PDF file
FSFunda Sirakaya
Funda Sirakaya
EÇEBRU ÇALIK
EBRU ÇALIK
MOMehmet Ruhi Onur
Mehmet Ruhi Onur
EDErkan Dikmen
Erkan Dikmen
UKUlas Kumbasar
Ulas Kumbasar
RDRiza Dogan
Riza Dogan
Background: The most common surgery for non-small cell lung cancer is lobectomy, which can be performed through either thoracotomy or video-assisted thoracic surgery (VATS). Insufficient research has examined respiratory muscle function and exercise capacity in lobectomy performed using conventional thoracotomy (CT), muscle-sparing thoracotomy (MST), or VATS. This study aimed to assess and compare respiratory muscle strength, diaphragm thickness, and exercise capacity in lobectomy using CT, MST, and VATS. Methods: The primary outcomes were changes in respiratory muscle strength, diaphragm thickness, and exercise capacity. Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were recorded for respiratory muscle strength. The 6-min walk test (6MWT) was used to assess functional exercise capacity. Diaphragm thickness was measured using B-mode ultrasound. Results: The study included 42 individuals with lung cancer who underwent lobectomy via CT (n = 14), MST (n = 14), or VATS (n = 14). Assessments were performed on the day before surgery and on postoperative day 20 (range 17–25 days). The decrease in MIP (p < 0.001), MEP (p = 0.003), 6MWT (p < 0.001) values were lower in the VATS group than in the CT group. The decrease in 6MWT distance was lower in the MST group than in the CT group (p = 0.012). No significant differences were found among the groups in terms of diaphragmatic muscle thickness (p > 0.05). Conclusion: The VATS technique appears superior to the CT technique in terms of preserving respiratory muscle strength and functional exercise capacity. Thoracic surgeons should refer patients to physiotherapists before lobectomy, especially patients undergoing CT. If lobectomy with VATS will be technically difficult, MST may be an option preferable to CT because of its impact on exercise capacity.

5 February 2024 in Turkish Journal of Thoracic and Cardiovascular Surgery
Verified
Journal Article
Open access
PDF file
UKUlas Kumbasar
Ulas Kumbasar
There are many congenital anomalies of the lung, some of which have no clinical symptoms and are detected incidentally, while others, particularly in the neonatal and infant period, are recognized by their typical signs, symptoms, and radiological appearance. Some congenital lung anomalies are so important that they can cause the death of the patient if not diagnosed and treated early. Classification of congenital lung anomalies is difficult since these anomalies may be related to the airway, arterial and venous vascular system, pulmonary parenchyma, and primitive anterior intestinal anomalies from which the lung originates, and some anomalies may have several etiologic origins. In this review, all subgroups of congenital pulmonary malformations will be discussed.