Evaluation of Percutaneous Unilateral Kyphoplasty Results in Osteoporotic Vertebral Compression Fractures Using Individual 3D Printed Guide Template Support.

AIM: To compare the clinical and radiological outcomes of unilateral percutaneous kyphoplasty (PKP) surgeries performed using 3D printing technology in patients with osteoporotic compression fractures to conventional unilateral PKP surgeries. MATERIAL AND METHODS: Patients with acute painful single-level osteoporotic vertebral compression fracture (OVCF) who need surgical treatment were divided into two groups: group A (patients who had 3D template-guided PKP) and group B (patients who conventional PKP). To compare the two surgical procedures, Total Absorbed Radiation Dose (TARD), pre- and postoperative visual analog scale (VAS) scores, and Total Surgery Time (TST) were calculated and compared between groups in both surgical groups. RESULTS: A total of 44 patients with single-level OVCF who were experiencing acute pain were successfully operated on, with 22 patients in each group. TARD (2.6 ± 0.4 mGy vs. 6.1 ± 1.9 mGy, p < 0.05) and TST (12.4 ± 2.6 min vs. 20.2 ± 3.2 min, p < 0.05) differed significantly different between groups A and B. There was no statistically significant difference between the patient groups in preoperative and postoperative VAS values (p > 0.05). Cement leakage was lower in group A (3/22, 13.6%) than in group B (6/22, 27.3%) (p > 0.05). There were no neurological complications or infections in either group. CONCLUSION: When compared to the conventional procedure, the unilateral percutaneous kyphoplasty method was supported by a 3D printing guide template. By reducing operative time and radiation exposure, tt has resulted in a more effective surgical procedure for patients and a safer surgical procedure for surgeons and anaesthesiologists.

The effect of music on menopausal symptoms, sleep quality,and depression: a randomized controlled trial.

OBJECTIVE: This study aimed to determine the effect of music on menopausal symptoms, sleep quality, and depression levels in menopausal women. METHODS: This randomized controlled study was carried out between August and December 2022. The study sample consisted of 61 menopausal women (intervention: 30 and control: 31). The intervention group listened to music twice a day for 5 weeks, with a total of 70 sessions. The control group received only routine care. Menopause symptoms, depression levels, and sleep quality were evaluated at the beginning and the end of the study using the Menopausal Symptoms Rating Scale, Beck Depression Inventory, and Pittsburg Sleep Quality Index. RESULTS: The post-test Menopausal Symptoms Rating Scale, Beck Depression Inventory, and Pittsburg Sleep Quality Index scores of the menopausal women were found to be lower in the intervention group than in the control group (p=0.011, p=0.001, and p=0.006, respectively). When the pre-test and post-test mean scores were compared, the mean menopausal symptoms and depression levels decreased, and sleep quality increased significantly in the intervention group. No significant difference was observed in the control group. CONCLUSION: This study shows that music may have an effect on reducing the level of menopausal symptoms and depression levels and also increasing the sleep quality of menopausal women.

Neurochemical Research of LOXBlock-1 and ZnSO4 against Neurodegenerative Damage Induced by Amyloid Beta(1-42).

Synaptosomes offer an intriguing ex vivo model system for investigating the molecular mechanisms of neurodegenerative processes. Lipoxygenases significantly affect the course of neurodegenerative diseases. Homeostasis of trace elements such as zinc is necessary for the continuity of brain functions. In this study, we purpose to determine whether LOXBlock-1, a 12/15 lipoxygenase inhibitor, and zinc sulfate (ZnSO4) provide any biochemical protection during neurodegenerative damage in synaptosomes induced by amyloid beta 1-42 (Aß1-42). In this study, animals (30 Wistar Albino male rats 30) were divided into 5 groups (6 animals in each group): Control, 10µM Aß1-42, 10µM Aß1-42+25mM LOXBlock-1, 10µM Aß1-42+10µM ZnSO4, and 10µM Aß1-42+25mM LOXBlock-1+10µM ZnSO4. Synaptosomes were isolated from the rat cerebral cortex. Following, 8-hydroxy-2-deoxyguanosine (8-OHdG) levels, malondialdehyde (MDA) levels, adenosine deaminase (ADA) levels, reduced-glutathione (GSH) levels, neuronal nitric oxide synthase (nNOS) levels, acetylcholinesterase (AChE) activity, catalase (CAT) activity, and 8-OHdG levels in synaptosomes were detected according to the ELISA method. ADA and AChE expression and protein levels were analyzed. MDA, nNOS, AChE, and 8-OHdG levels in synaptosomes treated with Aß1-42 resulted in an increase, while there was a decrease in ADA, GSH, and CAT levels (p<0.001 vs. control). Conversely, LOXBlock-1 and ZnSO4 treatments in synaptosomes treated with Aß1-42 decreased MDA, nNOS, AChE, and 8-OHdG levels, while ADA, GSH, and CAT levels increased. Moreover, the most effective improvement was seen in the co-treatment group of LOXBlock-1 and ZnSO4. Our data showed that LOXBlock-1 and ZnSO4 co-treatment may protect against Aß1-42 exposure in rat brain synaptosomes.

Investigation of the Anticancer Effect of S-Allyl-L Cysteine on the C6 Rat Glioma Cell Line in vitro in 2D- and 3D-Cell Culture Models.

AIM: To investigate the antiproliferative and apoptotic effects of S-allyl cysteine (SAC) on C6 glioblastoma cells using two- and three-dimensional (2D and 3D) cell culture systems. MATERIAL AND METHODS: Three groups of rat glioma cell line C6 were prepared: 2D-Control, 2D-SAC, 3D-CMC-Control, and 3D-CMC-SAC. The control cells were incubated under standard culture conditions, the SAC cells were incubated in a culture medium supplemented with the IC50 dose (50 ?M for both the 2D-SAC C6 and 3D-CMC-SAC groups) of SAC for 24 and 48 h. All experimental cells were stained with antibodies recognizing NOTCH1 and JAGGED1, and the mRNA expression levels of NOTCH1 and JAGGED1 were evaluated by qRT-PCR. RESULTS: Increasing doses of SAC were administered for 24 h to the C6 glioma cell line. The concentration of 50 ?M was selected as the most suitable dose for administration. The gene expression profiles differed between these two cell culture types. We found that the expression levels of NOTCH1 receptor mRNA were lower in cells exposed to 50-?M SAC for 24 h than those of control cells in both 2D and 3D cell cultures. The immunoreactivities of both the biomarkers JAGGED1 and NOTCH1 in the glioma cells decreased significantly in the SAC group. CONCLUSION: These findings indicate that SAC is a potential drug candidate for human use, as indicated by its nontoxic nature. In addition, SAC was found to exert an anticancer effect, which is associated with the modulation of JAGGED1 and NOTCH1 signaling pathways in glioma cancer cells.

Vitamin-based radiopharmaceuticals for tumor imaging.

Advances in nuclear medicine, such as single photon emission computed tomography (SPECT) and positron emission tomography (PET), are among the most sensitive methods that can be used in diagnostic imaging and radionuclide therapy with higher efficiency and reduced toxicity benefits. In order to improve the success of treatment, it is also important to develop methods that can be used when lesions can be detected at the earliest stages. Vitamins are macromolecules that play a crucial role in numerous biological processes in both animals and humans. Escalating development of vitamin-based radiopharmaceuticals for application in the diagnosis and treatment of cancers. In this review, we aimed to discuss about recent research utilizing radio-labeled vitamins for targeted tumor imaging.

Spine and spinal cord injuries in Syria war: treatment and outcome.

STUDY DESIGN: This was a retrospective, comparative 6-year study. OBJECTIVES: This study aimed to retrospectively analyze patients who were treated at Kilis State Hospital for spine and spinal cord injuries during the Syrian civil war and to compare the treatment results with the literature. SETTING: Kilis State Hospital, Kilis, Turkey. METHODS: In our study, 84 patients who were treated for spine and spinal cord injuries between December 2011 and May 2017 were examined. Patient age, sex, injury type, injury region, neurological status, time from injury to treatment, treatment methods, surgical methods applied, and complications were evaluated. RESULTS: Of the patients, 72 were male, and 12 were female. The mean age of the patients was 23.2 ± 7.3 years. Fifty-two patients were treated surgically. Surgical treatment was applied to 44 patients with neurological deficits. At least 1-grade neurological improvement was observed in 77.3% (n = 34) of patients with neurological deficits who underwent surgical treatment. Surgical treatment was performed on 18 (34.6%) patients in the first 24 h, 27 (51.9%) patients within 24-72 h, and 7 patients (13.5%) between 72 h and 5 days. Neurological improvement was observed in all patients with neurological deficits who underwent surgical treatment in the first 24 h. CONCLUSIONS: Early surgery (in the first 24 h) had a positive effect on the neurological recovery of the patients in our study. Thus, patients with spine and spinal cord injuries rendered a surgical-treatment decision should be operated on in a timely manner, particularly within the first 24 h.

Corrosion, ion release, and surface hardness of Ti-6Al-4V and cobalt-chromium alloys produced by CAD-CAM milling and laser sintering.

STATEMENT OF PROBLEM: How the corrosion properties of cobalt-chromium (Co-Cr) and Ti (Ti-6Al-4V) alloys, frequently used in dental prostheses, are affected by different production methods is unclear. PURPOSE: The purpose of this in vitro study was to compare Co-Cr and Ti-6Al-4V alloys produced by computer-aided design and computer-aided manufacturing (CAD-CAM) milling or laser sintering in terms of corrosion, ion release, and surface hardness. MATERIAL AND METHODS: Co-Cr and Ti-6Al-4V specimens were produced by CAD-CAM milling and direct metal laser sintering/selective laser sintering techniques. Testing included Vickers hardness and then open circuit potential (OCP), Tafel extrapolation, and static immersion to determine the corrosion behavior. The study used an inductively coupled plasma mass spectrometer to measure ion release. The data were analyzed by using the Kruskal-Wallis and Mann-Whitney U tests, with Bonferroni correction (α=.05). RESULTS: The Ti-6Al-4V laser-sintered group showed the highest Vickers hardness value (P<.008), the lowest OCP value (P<.008), and the lowest corrosion potential (Vcorr) value (P<.008). The corrosion current density (Icorr) level of the Co-Cr CAD-CAM milling group was statistically significantly lower than that of the Ti-6Al-4V CAD-CAM milling and the Ti-6Al-4V laser-sintered groups (P<.008). The highest weight change was observed in the Ti-6Al-4V laser-sintered group. The Co, Cr, and Ti ion emissions were higher in specimens produced by laser sintering (P<.05), and no statistically significant difference in terms of Al and V oscillations was found among the groups (P>.05). CONCLUSIONS: Ti-6Al-4V alloys may be a good alternative for patients with Co-Cr allergies, but as per the results of this study, Co-Cr still seems more suitable for clinical use.

Pediatric cranial injuries: the Syrian civil war.

OBJECTIVE: Kilis, Turkey, a city near Aleppo, Afrin and Azez, Syria, where conflicts are intense, is one of the cities that provides initial emergency treatment. The aim in this study was to analyze the clinical and radiological characteristics of and treatment methods and results in pediatric patients admitted to Kilis State Hospital with cranial gunshot wounds obtained during the Syrian war. MATERIALS AND METHODS: In this study, 62 pediatric patients treated for cranial gunshot wounds obtained during the civil war in Syria between December 2011 and May 2017 at the Neurosurgery Clinic of Kilis State Hospital on the Turkish side of the Turkey-Syria border were retrospectively analyzed. RESULTS: A total of 62 patients were evaluated. Forty-six (74.2%) patients were male and 16 (25.8%) were female. The mean age of the patients was 11.4 ± 6.3 (range: 1 month to 18 years) years. The mean Glasgow coma scale (GCS) score was 7.2 ± 3.8. Surgical treatment was performed in 36 patients (58.1%). Six (16.7%) of the surgically treated patients and 15 (57.7%) of the conservatively treated patients died (p < 0.001). While good clinical results (GOS4-5) were obtained in 24 (66.7%) patients who underwent surgical treatment, only 8 (30.8%) patients who underwent conservative treatment had good clinical results (GOS 4-5). The treatment results in patients with a GCS score of between 9 and 15 who were treated with both methods were significantly better (GOS score of 4-5) (p < 0.05) than those in patients with a GCS score of 8 or lower. The treatment results of the patients aged 10-18 years were significantly better than those of patients aged 0-9 years (GOS 4-5) (p < 0.05). CONCLUSION: In this study, the GCS score on admission was a significant predictive factor for survival in pediatric patients with cranial gunshot wounds. The outcomes of patients aged 0-9 years with severe neurological damage were worse than those in patients aged 10-18 years. On the basis of the analyses of the treatment methods and GCS and GOS scores of the patients in our study, we conclude that surgical treatment should be performed immediately in all patients with radiological indications and a GCS score higher than 3. Additionally, we conclude that child soldiers exist in Syria.

Comparison of cerebral AVMs in patients undergoing surgical resection with and without prior endovascular embolization.

AIM: Brain arteriovenous malformations (AVMs) are congenital anomalies that present as intracranial hemorrhage or epilepsy. AVMs often remain clinically silent for extended periods. Although AVM treatment methods are controversial, three treatment strategies are usually combined or applied alone: surgical removal, embolization and stereotactic radiosurgery. We compared clinical and radiological outcomes in intracranial AVM patients treated via surgical resection with and without prior embolization. MATERIALS AND METHODS: Patients who did (30 patients) and did not (30 patients) undergo endovascular embolization before surgical resection at the Izmir Katip Çelebi University Atatürk Training and Research Hospital Neurosurgery Clinic from 2011 to 2019 were included in this retrospective, cohort study. Symptoms at diagnosis, comorbidities and clinical (AVM and Spetzler-Martin grade) and morphological characteristics were assessed. RESULTS: A mean one-year follow-up assessed outcomes using the modified Rankin score, and imaging studies assessed AVM obliteration post-procedure. Mean operation times for surgical resection with and without embolization were 166.50 ± 32.02 and 204.47 ± 26.66 min, respectively. Mean patient hospitalization periods for surgical resection with and without embolization were 8.43 ± 3.60 and 12.00 ± 5.51 days, respectively. CONCLUSION: Among patients who underwent surgical resection, significant operation time and hospitalization time differences were observed in favor of patients who underwent embolization, indicating that preoperative embolization is a safe and beneficial method for treating ruptured and non-ruptured AVMs.

Effect of the "Time to Surgery" on Civil Cranial Gunshot Injuries: Syria War.

ABSTRACT: Studies on cranial gunshot injuries in the Syrian war are present in the literature. However, the effect of surgical timing on the clinical outcomes of patients undergoing surgical treatment has not been discussed extensively. In this study, the time from injury to surgery is called "time to surgery." Kilis, a city close to Aleppo, Afrin, and Azez, where the conflicts in Syria are intense, is one of the cities where the first emergency treatments were administered. This study aimed to evaluate patients who underwent surgery in Kilis State Hospital due to cranial gunshot injury in the Syrian war and to investigate the effect of surgical timing on mortality and Glasgow Outcome Score.Surgical treatment was applied to 42 (32.8%) patients in the first 4 hours, 64 (50%) patients within 4 to 24 hours, and 22 (17.2%) patients between 24 hours and 3 days. As the time to surgery decreased, the good Glasgow Outcome Score (GOS) (4-5) outcome rates increased. The differences in surgical timing and GOS results of patients with Glasgow Coma Score (GCS) <8 and >8 were found to be significant for good GOS results. As the time to surgery decreased for patients with a GCS <8 and >8, mortality rates decreased equally. This result was statistically significant.Our study showed that surgical timing is as important as early intubation, aggressive resuscitation, and admission GCS for both survey and GOS.

Are 3D Printing Templates an Advantage in Upper Thoracic Pedicle Screw Fixation?

Background This study aims to compare the clinical results of patients with upper thoracic vertebral fractures treated with pedicle screw and posterior spinal fusion with preoperative surgical planning and 3-dimensional (3D) modeling and patients treated with freehand screws. Methods Fifty patients who underwent pedicle screw placement with a diagnosis of upper thoracic fracture between June 2018 and October 2020 were included in our study. Pedicle screws were used in 25 patients (group 1) after the planning was completed with the help of 3D preoperative printing and modeling. Pedicle screws were applied in 25 patients in the control group (group 2) using the freehand technique. Intraoperative bleeding amount, operation time, and correct screw placement data in both groups were recorded. Results The operation time was 134 ± 22 minutes for group 1 and 152 ± 38 minutes for group 2. The difference in operation times was found to be statistically significant (p < 0.05). Based on axial and sagittal reconstruction images, the accuracy rate of pedicle screw placement (grades 0 and 1) in group I was 96.6% compared to 83.6% in group II. The minor perforation rate (grade 1, <2 mm) was 5.8% in group I compared to 11.8% in group II. The moderate perforation rate (grade 2, 2-4 mm) was 3.4% in group I compared to 14% in group II. The severe perforation rate (grade 3, >4 mm) was 2.3% in group II; however, misplaced screws were not associated with neurological deficits. The difference in overall accuracy rates between the two groups was significant (p < 0.05). Conclusions For 3D models of upper thoracic pedicle screw insertion, guide plates can be produced inexpensively and individually. It provides a new method for the accurate placement of upper thoracic pedicle screws with high accuracy and secure use in screw insertion.

Investigation of the Effects of Three-Dimensional Modeling Techniques on Degenerative Rotoscoliosis Surgery.

Objectives The present study aimed to compare patients in whom an operation plan was prepared before surgery using the three-dimensional (3D) modeling technology with the application of freehand screws using magnetic resonance imaging (MRI) and computed tomography (CT) scan images. Methods The printings and modelings were established in the Training and Research Center. Of 40 patients, 20 underwent surgery with 3D printing (Group 1) and 20 with the freehand technique (Group 2). The surgeries were performed by the same surgeons. Moreover, 5-mm pedicle screws were located in 122 vertebrae in 20 patients in whom 3D modeling was used and in 124 vertebrae in 20 patients in whom this modeling technique was not used. Results The mean time of screw insertion was 2.9 ± 1.2 minutes in the experimental group and 4.7 ± 2.3 minutes in the control group. While the mean amount of bleeding was 7.4 ± 4.1 ml in the experimental group, it was found to be 39.6 ± 14.2 ml in the control group. When the locations of the screws in the experimental group were evaluated, it was seen that 106 (86.9%) screws were 'excellent' and 16 (13.1%) screws were 'good.' When the placement of 124 pedicle screws in the control group was evaluated, it was found that 100 (80.6%) screws were 'excellent,' 20 (17.8%) screws were 'good,' and two (1.6%) screws were 'poor.' Conclusion The use of the improved 3D technology in the neurosurgery field is advantageous for surgeons, as it decreases the preoperative preparation phase, length of operation, and risk of complications.

Edema-mass Ratio Based On Magnetic Resonance Imaging As A Preoperative Diagnostic Factor For Posterior Fossa Metastasis.

BACKGROUND: Peritumoral edema of primary brain tumors is an important cause of morbidity and mortality. The number of studies currently available on the prognostic role of peritumoral brain edema in the posterior fossa is extremely limited. OBJECTIVE: Based on the known importance of magnetic resonance imaging in diagnosing supratentorial metastases, this study aimed to investigate the effects of peritumoral edema on survival of patients with posterior fossa metastases and the preoperative diagnostic value of MRI. METHODS: Edema and mass volumes of 49 patients with posterior fossa metastasis, who underwent surgery during 2012-2016, were measured using magnetic resonance imaging. The edema/mass indices were retrospectively calculated and interpreted by evaluating the demographic, clinical, and survival data. RESULTS: The study consisted of 32 (65.3%) male and 17 (34.7%) female participants, with the mean age ± standard deviation of 47.25±29.25 (17-81) years. Among the 49 patients with posterior fossa metastases, 34 (69.4%) had carcinoma, while 15 (30.6%) had non-carcinoma metastases. The edema/mass indices of patients with carcinoma and non-carcinoma metastases were found to be 14.55±9.64 and 1.34±1.08, respectively, and the difference was statistically significant (p<0.001). The mean survival of patients with carcinoma and non-carcinoma metastases was found to be 642±11.52 days and 726±9.32 days, respectively; however, this difference was not statistically significant (p=0.787). CONCLUSION: The edema/mass ratio was found to be a significant diagnostic factor for the prediction of posterior fossa metastases. Further detailed studies are warranted to investigate the effect of edema/mass ratio on survival rate.

Detection of Lung Cancer on Computed Tomography Using Artificial Intelligence Applications Developed by Deep Learning Methods and the Contribution of Deep Learning to the Classification of Lung Carcinoma.

BACKGROUND: Every year, lung cancer contributes to a high percentage deaths in the world. Early detection of lung cancer is important for its effective treatment, and non-invasive rapid methods are usually used for diagnosis. INTRODUCTION: In this study, we aimed to detect lung cancer using deep learning methods and determine the contribution of deep learning to the classification of lung carcinoma using a convolutional neural network (CNN). METHODS: A total of 301 patients diagnosed with lung carcinoma pathologies in our hospital were included in the study. In the thorax, Computed Tomography (CT) was performed for diagnostic purposes prior to the treatment. After tagging the section images, tumor detection, small and non-small cell lung carcinoma differentiation, adenocarcinoma-squamous cell lung carcinoma differentiation, and adenocarcinoma-squamous cell-small cell lung carcinoma differentiation were sequentially performed using deep CNN methods. RESULTS: In total, 301 lung carcinoma images were used to detect tumors, and the model obtained with the deep CNN system exhibited 0.93 sensitivity, 0.82 precision, and 0.87 F1 score in detecting lung carcinoma. In the differentiation of small cell-non-small cell lung carcinoma, the sensitivity, precision and F1 score of the CNN model at the test stage were 0.92, 0.65, and 0.76, respectively. In the adenocarcinoma-squamous cancer differentiation, the sensitivity, precision, and F1 score were 0.95, 0.80, and 0.86, respectively. The patients were finally grouped as small cell lung carcinoma, adenocarcinoma, and squamous cell lung carcinoma, and the CNN model was used to determine whether it could differentiate these groups. The sensitivity, specificity, and F1 score of this model were 0.90, 0.44, and 0.59, respectively, in this differentiation. CONCLUSION: In this study, we successfully detected tumors and differentiated between adenocarcinoma- squamous cell carcinoma groups with the deep learning method using the CNN model. Due to their non-invasive nature and the success of the deep learning methods, they should be integrated into radiology to diagnose lung carcinoma.

Transformation of SH-SY5Y cell line into neuron-like cells: Investigation of electrophysiological and biomechanical changes.

SH-SY5Y human neuroblastoma cells are commonly used as neuronal models. Here, we examined different aspects of SH-SY5Y cell differentiation. Various differentiation protocols have been proposed previously, including treatments with retinoic acid, brain-derived neurotrophic factor (BDNF), cholesterol and oestradiol. We examined undifferentiated SH-SY5Y cells (UNDIFF); cells differentiated by the treatment with retinoic acid (RA); retinoic acid + BDNF (RB); and retinoic acid + BDNF + cholesterol + oestradiol (RBCE). We performed whole-cell patch-clamp recordings from these cells and nanomechanically characterised them by using atomic force microscopy (AFM). Our results indicated that Na+ currents become most pronounced in the differentiated RB cells, whereas UNDIFF SH-SY5Y cells had significantly larger K+ currents, which is a characteristic feature of cancer cells. AFM observations of these two groups showed that Young's moduli of SH-SY5Y cells increased threefold with differentiation. Furthermore, we showed a direct relationship between Na+ channel activity and elasticity in these cells. We conclude that SH-SY5Y human neuroblastoma cells should be used as a neuronal model only when they are differentiated by the treatment with retinoic acid and BDNF.

A Transient Survival Model of Alteration of Electrophysiological Properties Due to Amyloid Beta Toxicity Based on SH-SY5Y Cell Line.

BACKGROUND: Accumulation of toxic strands of amyloid beta (AB), which cause neurofibrillary tangles and, ultimately, cell death, is suspected to be the main culprit behind clinical symptoms of Alzheimer's disease. Although the mechanism of cell death due to AB accumulation is well known, the intermediate phase between the start of accumulation and cell death is less known and investigated, partially due to technical challenges in identifying partially affected cells. OBJECTIVE: First, we aimed to establish an in vitro model that would show resilience against AB toxicity. Then we used morphological, molecular and electrophysiological assays to investigate how the characteristics of the surviving cells changed after AB toxicity. METHODS: To investigate this phase, we used differentiation of SH-SY5Y neuroblastoma stem cells by Retinoic Acid (RA) and Brain Derived Neurotrophic Factor (BDNF) to establish an in vitro model which would be able to demonstrate various levels of resistance to AB toxicity. We utilized fluorescent microscopy and whole cell patch clamp recordings to investigate behavior of the model. RESULTS: We observed significantly higher morphological resilience against AB toxicity in cells which were differentiated by both Retinoic Acid and Brain Derived Neurotrophic Factor compared to Retinoic Acid only. However, the electrophysiological properties of the Retinoic Acid + Brain-Derived Neurotrophic Factor differentiated cells were significantly altered after AB treatment. CONCLUSION: We established a transient survival model for AB toxicity and observed the effects of AB on transmembrane currents of differentiated neurons.

Three Dimensional Printing and Biomaterials in the Repairment of Bone Defects; Hydroxyapatite PLA Filaments

Background/aim: Application fields of bone tissue engineering studies continue to expand. New biocompatible materials aimed to improve bone repairment and regeneration of implants are being discovered everyday by scientists, engineers, and surgeons. Our objective in this study is to combine polylactic acid which is a polymer with hydroxyapatite in the repairment of bone defects considering the increased need by medical application fields. Materials and methods: After 750 g of PLA with a diameter of 2.85 mm was granulated into minimum particles, these particles were homogenously mixed with hydroxyapatite prepared in laboratory environment. Using this mixture, HA-PLA filament with a diameter of 2.85 mm was prepared in the extrusion device in Kütahya Medical Sciences University Innovative Technology Laboratory. The temperature was 250 °C and the gearmotor speed was 9 rpm during extrusion. X-ray diffraction (XRD) analysis was made for crystal phase analyses of the produced hydroxyapatite powder, to determine the produced main phase and examine whether a minor phase occurred. Vickers microhardness test was applied on both samples to measure the endurance levels of the samples prepared with HA-PLA filament. A loading force of 10 kg was applied on the samples for 10 s. Results: Hydroxyapatite peaks in XRD spectrum of the sample presented in figures are concordant with Joint Committee on Powder Diffraction Standards, JCPDS - File Card No. 01-075-9526 and no significant minor phase was observed. For both samples, hardness value was observed to increase between 3 and 5 mm. Conclusion: Surfacing hydroxyapatite on metallic materials is possible. By similar logic, to increase durability with low cost, characteristics of biomaterials can be improved with combinations such as hydroxyapatite PLA. Thus, we found that while these materials have usage limitations due to present disadvantages when used alone, it is possible to increase their efficiency and availability through different combinations.