Predictive value of admission neutrophil/lymphocyte ratio in symptomatic intracranial hemorrhage after stroke thrombolysis.

BACKGROUND: Stroke is one of the most common causes of morbidity and mortality. The need for additional objective parameters as well as the existing criteria continues for eligible patients. The objective of this study is to determine whether the baseline neutrophil/lymphocyte ratio (NLR) predicts symptomatic intracranial hemorrhage (SICH) due to intravenous thrombolytic therapy. MATERIAL AND METHODS: One hundred thirty-three consecutive patients aged 18 years and over who were admitted to the emergency department of a training and research hospital for acute ischemic stroke and underwent intravenous thrombolytic therapy were retrospectively analyzed. For the definition of SICH, European Cooperative Acute Stroke Study III (ECASS III) classification was accepted. RESULTS: When the groups with and without intracranial hemorrhage were compared, there was a significant difference in terms of the initial National Institutes of Health Stroke Scale (NIHSS) score (p < 0.006), glucose level (p < 0.018), and systolic blood pressure (SBP) (p < 0.050). The NLR value of the patients ranged from 0.47 to 13.74. In the group with SICH, NLR was found to be higher but not statistically significant. (p = 0.125). CONCLUSION: For predicting SICH, NLR did not provide strong specificity and sensitivity. A precise cut-off value could not be found to predict the hemorrhagic transformation.

Thiol/disulfide homeostasis in patients treated with normobaric or hyperbaric oxygen for carbon monoxide poisoning.

OBJECTIVES: We aimed to determine the value of thiol/disulfide homeostasis (TDH) as an oxidative stress marker in hyperbaric oxygen therapy (HBOT) and normobaric oxygen therapy (NBOT) patients presenting with carbon monoxide poisoning. In addition, we compared the effect of HBOT and NBOT on thiol/disulfide parameters. METHODS: This prospective study included 66 patients and 67 healthy individuals who presented to the emergency department. We evaluated serum native thiol, disulfide, and total thiol levels in 8 patients who received HBOT and 58 who received NBOT. We also compared pre- and post-treatment levels of disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol. RESULTS: There was a statistically significant difference between the case and control groups in native thiol and total thiol before NBOT (p < 0.006, p < 0.006). We also found a statistically significant difference between the groups in pre- and post-NBOT levels of native thiol and total thiol (p < 0.002, p < 0.003). However, our comparison of HBOT and NBOT showed no significant difference in the levels of native thiol, total thiol, disulfide, disulfide/native thiol, disulfide/total thiol, or native thiol/total thiol (p < 0.544, p < 0.860, p < 0.644, p < 0.409, p < 0.409, p < 0.409, respectively). CONCLUSIONS: Although thiol/disulfide parameters increased in patients receiving HBOT or NBOT, changes in antioxidant levels did not differ significantly between NBOT and HBOT patients. This suggests that NBOT and HBOT have similar effects on thiol/disulfide parameters. NBOT alone may be effective in centers that do not have HBOT facilities.

Relationship of platelet counts, platelet volumes, and Curb-65 scores in the prognosis of COVID-19 patients.

OBJECTIVES: This study investigated the relationship between 28-day mortality in patients with COVID-19 pneumonia and the CURB-65 score, platelet count (PLT), mean platelet volume (MPV), and MPV/PLT ratio (MPR). METHODS: A total of 247 patients with COVID-19 pneumonia who presented to the emergency department between March 15, 2020 and May 15, 2020 were retrospectively analyzed. The age, gender, clinical presentation, history of chronic disease, thoracic computed tomography findings, MPV, PLT, MPR, CURB-65 scores, and 28-day mortality of patients were recorded. RESULTS: The patients had a mean age of 51 years (IQR: 39-63 years) and 55.5% were females. The most common symptom was cough (30.4% of patients). The most common comorbidity was hypertension (13.4%), 49.8% of the cases showed intermediate involvement, and 7.7% of patients died within the first 28 days. The mean MPV was 9.71 ± 1.15, the mean PLT was 226.68 ± 83.82, and the mean MPR was 0.056 ± 0.12. There were significant correlations of 28-day mortality with the CURB-65 score, MPV, and MPR levels (p = 0.000, p = 0.034, and p = 0.034, respectively). No significant correlation was found between the PLT count and 28-day mortality (p = 0.105). CONCLUSIONS: In addition to the CURB-65 score, MPV and MPR values can be used to predict 28-day mortality in patients with COVID-19 pneumonia.

Plasma oxidative-stress parameters and prolidase activity in patients with various causes of abdominal pain.

PURPOSE: We aimed to investigate the predictive power of plasma prolidase activity and oxidative-stress parameters for distinguishing in patients with various causes of non-traumatic abdominal pain who presented to the emergency department. METHODS: This study enrolled 100 consecutive adult patients and 100 age- and sex-matched healthy controls. The patients were divided into surgically treated patients (STP); medically treated patients (MTP) and nonspecific abdominal pain (NSAP) patients. As predictors of early oxidative changes, the plasma prolidase activity, total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) were assessed using a novel automated method. RESULTS: No significant difference was observed between the patients and the controls with respect to age or sex (p = 0.837 and 0.188, respectively). The plasma TOS, OSI value, and prolidase activity were significantly higher in the patients with abdominal pain than in the controls (p < 0.001, p = 0.001, and p < 0.001, respectively); however, there was no significant difference in the TAS (p = 0.211). The mean plasma TOS, OSI value, and prolidase activity differed significantly among the three groups (p < 0.001, p = 0.001, and p < 0.001, respectively). The STP had the highest TOS and prolidase activity. However, there was no significant difference in the mean plasma TAS in either group of patients (p = 0.419). CONCLUSION: The plasma prolidase activity and TOS level, as biomarkers of oxidative stress, enable discrimination of patients with NSAP from those with surgical abdominal pain that requires emergent surgical treatment.

Probiotic characteristics of Lactobacillus fermentum strains isolated from tulum cheese.

The aim of this study was to characterize the probiotic characteristics of Lactobacillus fermentum strains isolated from Tulum cheese. Seven L. fermentum strains were selected among the isolated and identified lactobacillus strains due to their abundance. When the gastric condition was considered, L. fermentum LP3 and LP4 were able to tolerate pH 2.5 and 1% bile salt. All L. fermentum strains had similar enzymatic activity and antibiotic resistance pattern but the highest antagonistic effect was detected within LP3, LP4 and LP6. Cholesterol assimilation amount of L. fermentum strains ranged between 12.1 and 45.3% in MRS and 20.7-71.1% in MRS with bile. The highest cholesterol assimilation in MRS and MRS with bile was occurred by LP3 and LP4, respectively. L. fermentum LP2 adhered to caco-2 cells more than Lactobacillus rhamnosus LGG where LP3, LP4 and LP5 adhered at similar level. In conclusion, L. fermentum LP3 and LP4 fulfilled sufficient criteria to be probiotics for use as a starter culture in the production of tulum cheese or other dairy products. Also this study indicated that some food-associated Lactobacillus strains non-predominant for gut biota have significant probiotic potential.

N-Acetyl cysteine and erdosteine treatment in acetaminophen-induced liver damage.

OBJECTIVE: This study is aimed to investigate the efficacy of erdosteine usage in acetaminophen-induced liver damage and to compare it with N-acetyl cysteine (NAC) in the treatment and prevention of liver toxicity due to overdose of acetaminophen. METHODS: The rats were separated into the following six groups of seven rats each: control group; acetaminophen (1 g/kg, orally); acetaminophen (1 g/kg, orally) + erdosteine (150 mg/kg/day, orally); acetaminophen (1 g/kg, orally) + NAC (140 mg/kg loading dose, followed by 70 mg/kg, orally); NAC (140 mg/kg loading dose, followed by 70 mg/kg, orally); erdosteine (150 mg/kg/kg, orally), subsequently. In all the groups, potential liver injuries were evaluated using biochemical and hematological analyses, oxidant-antioxidant parameters and histopathological parameters. RESULTS: In acetaminophen-treated group, levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total oxidant status (TOS) in the blood, prothrombin time (PT) and international normalized ratio (INR) were significantly increased when compared with controls. However, total antioxidant capacity (TAC) and glutathione (GSH) levels were decreased in group treated with acetaminophen, when compared with control group. Levels of AST, ALT and TOS, PT and INR were decreased in groups treated with NAC and erdosteine after acetaminophen administration, but the levels of TAC and GSH were increased. Histopathological improvements were observed in the groups treated with NAC and erdosteine after acetaminophen administration. CONCLUSION: The present study demonstrated that, in the prevention of liver damage induced by acetaminophen intoxication, an early treatment with a single dose of erdosteine was beneficial instead of NAC administration.

Factors affecting the clinical outcome of low-voltage electrical injuries in children.

PURPOSE: This study evaluated the clinical features of low-voltage (220-240 V) electrical injuries and their mortality in children. METHODS: This cross-sectional study evaluated 36 patients younger than 18 years who suffered a low-voltage electrical shock and presented to the emergency department between January 2009 and October 2011. For statistical analysis, Fisher exact test was used for categorical variables, and the Mann-Whitney U test for continuous variables. RESULTS: In the 34-month period, 36 patients (27 boys [75%] and 9 girls [25%]) were injured. The mean patient age was 9.19 ± 4.10 years (range, 2-17 years). Of the 36 patients, 5 (13.9%) died. Significant relationships were found between mortality and age (P =0.004), unconscious at the time of admission to the emergency department (P =0.013), the presence of clinical shock (P = 0.005), sinus tachycardia (P = 0.003), and high lactate dehydrogenase levels (P = 0.001). There were also significant relationships between mortality and hospital stay (P = 0.005), intensive care unit stay (P = 0.002), and detection of bacterial growth in blood culture (P = 0.024). By contrast, sex, the presence of an electrical exit wound, degree of the burn, surface area of the burn (%), accompanying flash burn, time elapsed transferring the patient from the accident scene to hospital, incomplete bundle-branch block or ST-wave changes on the electrocardiogram, increased troponin T, and creatine phosphokinase myocardial bundle did not affect mortality. CONCLUSIONS: Complications such as sepsis and electrolyte imbalance lead to mortality rather than low-voltage electrical injury itself.

Efficacy of aprotinin treatment on bilateral blunt chest trauma created in rabbits.

OBJECTIVES: To investigate the effects of aprotinin, on blood gasses, oxidant-antioxidant status, and lung histopathology in an experimental bilateral blunt chest trauma model. METHODS: Conducted at the Experimental Animal Laboratory of Meram Medical School at Selcuk University, Konya, Turkey, the study comprised 21 New Zealand female albino rabbits who were divided into three groups.Trauma was applied on the sham and aprotinin groups, which was administered intravenous Aprotinin 20.000 U/kg. Arterial blood samples were obtained from all rabbits at hours 0, 3, 24, and 96. At hour 96 after trauma, all rabbits were sacrificed using the decapitation method, and then blood and lung tissue samples were obtained. Blood nitric oxide, malondialdehyde and blood gas measurements were made. Histopathological changes in the lung were examined with a light microscope. RESULTS: While no positive effect of aprotinin was observed on nitric oxide malondialdehyde and partial pressure of carbon dioxide values, it was seen to have an increasing effect on partial oxygen pressure level. Aprotinin had a partial effect on lung histopathology. CONCLUSION: Aprotinin was determined to have a positive effect on PO2 levels. We could not find any positive effects especially on alveolar haemorrhage.

The role of deep learning for periapical lesion detection on panoramic radiographs.

OBJECTIVE: This work aimed to detect automatically periapical lesion on panoramic radiographs (PRs) using deep learning. METHODS: 454 objects in 357 PRs were anonymized and manually labeled. They are then pre-processed to improve image quality and enhancement purposes. The data were randomly assigned into the training, validation, and test folders with ratios of 0.8, 0.1, and 0.1, respectively. The state-of-art 10 different deep learning-based detection frameworks including various backbones were applied to periapical lesion detection problem. Model performances were evaluated by mean average precision, accuracy, precision, recall, F1 score, precision-recall curves, area under curve and several other Common Objects in Context detection evaluation metrics. RESULTS: Deep learning-based detection frameworks were generally successful in detecting periapical lesions on PRs. Detection performance, mean average precision, varied between 0.832 and 0.953 while accuracy was between 0.673 and 0.812 for all models. F1 score was between 0.8 and 0.895. RetinaNet performed the best detection performance, similarly Adaptive Training Sample Selection provided F1 score of 0.895 as highest value. Testing with external data supported our findings. CONCLUSION: This work showed that deep learning models can reliably detect periapical lesions on PRs. Artificial intelligence-based on deep learning tools are revolutionizing dental healthcare and can help both clinicians and dental healthcare system.

A prospective study of wake-up stroke patients presenting to the emergency department: a single-center cohort study.

INTRODUCTION: This study aims to prospectively examine patients with ischemic wake-up stroke (WUS) presenting to the emergency department, to investigate the risk factors affecting the mortality occurring within 28, 90, and 180 days, and to create a new scoring system for the prediction of 28-day mortality. MATERIALS AND METHOD: Patients who presented to the emergency department with WUS findings between 01.07.2019 and 30.06.2020 were prospectively analyzed. Logistic regression analysis was performed to determine the factors affecting mortality and the modified Rankin scale (mRS). RESULTS: A total of 161 patients were included. Of the patients, 22.4% died within 28 days and 40.4% within 180 days. The presence of coronary artery disease (CAD) increased the 28-day mortality risk (p = 0.009) 3.57 times, 90-day mortality risk 2.15 times (p = 0.033), and 180-day mortality risk 2.18 times (p = 0.045). In order to be used in the prediction of 28-day mortality in patients with WUS, we developed the ischemic WUS mortality score (IWUSMOS), which consists of the middle cerebral artery (45 points), internal carotid artery (60 points), basilar artery (39 points), superior cerebellar artery (66 points) occlusion, hypertension (33 points), CAD (28 points), malignancy (100 points), and arrhythmia (23 points). With this scoring system, the 28-day mortality risk was determined as 0.05% when the total score was "43" whereas the mortality risk was found to be 95.0% when the total score was "187." CONCLUSION: We propose that IWUSMOS, a new scoring system, can be used to predict the 28-day mortality risk of patients with WUS.

The effect of heart failure on gut microbial richness and diversity.

INTRODUCTION AND OBJECTIVE: With recent advances in genome sequencing technology, a large body of evidence has accumulated over the last few years linking alterations in microbiota with cardiovascular disease. In this study, we aimed to compare gut microbial composition using 16S ribosomal DNA (rDNA) sequencing techniques in patients with coronary artery disease (CAD) and stable heart failure (HF) with reduced ejection fraction and patients with CAD but with normal ejection fraction. We also studied the relationship between systemic inflammatory markers and microbial richness and diversity. METHODS: A total of 40 patients (19 with HF and CAD, 21 with CAD but without HF) were included in the study. HF was defined as left ventricular ejection fraction <40%. Only stable ambulatory patients were included in the study. Gut microbiota were assessed from the participants' fecal samples. The diversity and richness of microbial populations in each sample were assessed by the Chao1-estimated OTU number and the Shannon index. RESULTS: The Chao1-estimated OTU number and Shannon index were similar between HF and control groups. There was no statistically significant relationship between inflammatory marker levels (tumor necrosis factor-alpha, interleukin 1-beta, endotoxin, C-reactive protein, galectin-3, interleukin 6, and lipopolysaccharide-binding protein) and microbial richness and diversity when analyzed at the phylum level. CONCLUSION: In the current study, compared to patients with CAD but without HF, stable HF patients with CAD did not show changes in gut microbial richness and diversity. At the genus level Enterococcus sp. was more commonly identified in HF patients, in addition to certain changes in species levels, including increased Lactobacillus letivazi.

Investigating the effects of the COVID-19 pandemic on the reasons for application to the emergency department in patients with neurological symptoms.

OBJECTIVE: To investigate whether the COVID-19 pandemic had an effect on the emergency department admission complaints of patients with neurological symptoms. METHODS: A total of 976 patients admitted to the emergency department of our hospital and had undergone neurology consultation during a 6-month period were evaluated. The reasons for consultation, the number of patients consulted, hospitalization counts, and imaging studies for neurological assessment including computerized tomography (CT) and magnetic resonance imaging (MRI), were recorded and compared. RESULTS: Compared to the pre-pandemic period, there were significant decreases in the number of neurological consultations requested by the emergency department (overall and related to stroke, seizure and other reasons) and the number of patients hospitalized in the neurology department. We also found that the number of orders for cranial CT and MRI images during the pandemic period had decreased significantly. CONCLUSION: Restrictions, social isolation measures and patients' reluctance to apply to hospitals to avoid contact with possibly infected people may have led to a decrease in the number of patients with neurological symptoms admitted to the emergency department and the number of hospitalized patients.

The effect of the shock index and scoring systems for predicting mortality among geriatric patients with upper gastrointestinal bleeding: a prospective cohort study.

BACKGROUND: Gastrointestinal (GI) bleeding is an important cause of mortality and morbidity among geriatric patients. OBJECTIVE: To investigate whether the shock index and other scoring systems are effective predictors of mortality and prognosis among geriatric patients presenting to the emergency department with complaints of upper GI bleeding. DESIGN AND SETTING: Prospective cohort study in an emergency department in Bursa, Turkey. METHODS: Patients over 65 years admitted to a single-center, tertiary emergency service between May 8, 2019, and April 30, 2020, and diagnosed with upper GI bleeding were analyzed. 30, 180 and 360-day mortality prediction performances of the shock index and the Rockall, Glasgow-Blatchford and AIMS-65 scores were evaluated. RESULTS: A total of 111 patients who met the criteria were included in the study. The shock index (P < 0.001) and AIMS-65 score (P < 0.05) of the patients who died within the 30-day period were found to be significantly different, while the shock index (P < 0.001), Rockall score (P < 0.001) and AIMS-65 score (P < 0.05) of patients who died within the 180-day and 360-day periods were statistically different. In the receiver operating characteristic (ROC) analysis for predicting 360-day mortality, the area under the curve (AUC) value was found to be 0.988 (95% confidence interval, CI, 0.971-1.000; P < 0.001). CONCLUSION: The shock index measured among geriatric patients with upper GI bleeding at admission seems to be a more effective predictor of prognosis than other scoring systems.

Pneumomediastinum and subcutaneous emphysema due to blunt neck injury: a case report and review of the literature.

Minor blunt neck injury from childhood trauma is a relatively common condition which can be potentially life-threatening in only rare circumstances. Pneumomediastinum may develop in up to 10% patients who have sustained blunt cervical or thoracic trauma and may be a significant cause of morbidity and mortality in affected individuals because of the associated damage to the oesophagus, larynx or trachea. Management of this condition varies from conservative approach with close observation and antibiotherapy to surgical interventions, depending on the extent and severity of aerodigestive injuries. We present a paediatric blunt neck trauma accompanied by subcutaneous emphysema and pneumomediastinum secondary to a bicycle accident (neck striking the handlebar). Its radiologic appearance, clinical presentation, and the options for initial management in the emergency department (ED) are reviewed.

Measuring Optic Nerve Sheath Diameter with Bedside Ocular Ultrasonography in Patients with Carbon Monoxide Poisoning.

OBJECTIVE: To investigate the relationship between optic nerve sheath diameter (ONSD) and clinical and carboxyhemoglobin levels in patients with carbon monoxide poisoning. MATERIAL AND METHODS: This prospective cross-sectional study enrolled 55 consecutive adult patients with carbon monoxide poisoning. The demographic and clinical characteristics of the patients and the diameters of the optic nerve sheaths of both eyes of those patients at the time of admission and at the 6th hour after receiving 100% oxygen therapy and/or hyperbaric oxygen therapy were determined. The ages, genders, arterial blood pressure values, symptoms, carboxyhemoglobin levels, and bilateral ONSD values (measured sonographically before and after the oxygen therapy) of the patients were recorded in a data collection form. RESULTS: Measurements of ONSD before and after treatment were observed significantly (P = .01). Significant decreases were observed in ONSDs after treatment (P < .05). However, no significant difference was observed between ONSDs at the time of admission and after the treatment of patients receiving 2-hour single-session hyperbaric oxygen therapy and 100% oxygen therapy with a reservoir mask (P > .05). CONCLUSION: The changing of ONSD, which is an indirect indicator of increased intracranial pressure, is a promising method to use at emergency service for patients with carbon monoxide poisoning.

Evaluation of Syrian refugees' emergency service admissions in the western region of Turkey.

Immigration increases physical, mental, and social health problems. Emergency departments constitute resources that refugees can easily access and where they frequently present. Physicians from every specialty (chest diseases, thoracic surgery, internal diseases, etc.) may be consulted if needed. We aimed to compare demographic data and clinical characteristics of Syrian refugees and Turkish citizens in our emergency department. This study was an observational cross-sectional study. It included patients who presented to the Adult Emergency Department between April 1 and July 1, 2018. The patients were grouped into Syrian refugee and Turkish citizen groups. Patient age, gender, International Statistical Classification of Disease and Related Health Problems (ICD-10) diagnostic codes, and judicial case status were recorded from physician-patient outpatient clinic data records. Disease diagnoses and judicial cases were statistically compared between the two groups. A total of 30,749 patients presented to the emergency department during the study period. Of these, 999 were Syrian refugees. The mean ages of the Syrian refugees and Turkish citizens were significantly different. There were also differences between the two groups in the top five diagnostic codes (M79-Soft tissue disorders, J39-Other disorders of the upper respiratory tract; R51-Headache; R10-Abdominal and pelvic pain; M54-Dorsalgia). A comparison of the judicial cases also revealed a difference in mean age between the groups. Fewer specific disease diagnoses were identified among Syrian refugees. This may be explained by difficulties related to language barriers between the refugees and healthcare personnel.

Characterization of Pediococcus acidilactici PFC69 and Lactococcus lactis PFC77 Bacteriocins and Their Antimicrobial Activities in Tarhana Fermentation.

Tarhana is a traditional cereal product fermented by lactic acid bacteria (LAB) and yeast strains that has gained special interest recently as an infant nutrition. Tarhana contains wheat flour, yogurt, and various vegetables that might create a microbiological toxicological risk, especially for Bacillus cereus and Staphylococcus aureus. In this study, characterization of the metabolites responsible for antibacterial activity of Pediococcus acidilactici PFC69 and Lactococcus lactis PFC77 strains obtained from tarhana was performed, and antibacterial effects were detected against B. cereus ATCC 11778 and S. aureus ATCC 29213 during the fermentation. A total of 12,800 AU/mL antibacterial activity was observed for the supernatants of the PFC69 and PFC77 strains that were found to be stable at high temperature and in low pH conditions and sensitive to proteases, suggesting the antimicrobial metabolite is a bacteriocin. These bacteriocins were further purified and their molecular sizes were determined as 4.5 and 3.5 kDa, respectively. Importantly, inoculation of PFC69 and PFC77 to tarhana dough significantly decreased B. cereus ATCC 11778 and S. aureus ATCC 29213 amounts from the fifth day of fermentation compared to the control dough samples. P. acidilactici PFC69 and L. lactis PFC77 strains were concluded as bioprotective cultures for tarhana and these strains were offered for other cereal-based fermentations.

What is the emergency application differences concerning diseases pertinent to the chest between Turkish citizens and Syrian refugees: A cross-sectional study.

AIM: Millions of Syrians were displaced after the Syrian civil war broke in 2011. Turkey hosts the largest number of refugees. This study aimed to describe the disease patterns of Syrian refugees applying to an emergency department. MATERIAL AND METHODS: The study included patients who presented to an emergency department between 2017 and 2018. Study data were retrieved from the hospital's electronic medical records registry. The main study outcome was the ICD-10 codes pertinent to "chest diseases." Additionally, analyzed data were nationality, age, sex, triage status on admission, hospitalization status, and examination date. RESULTS: The number of emergency department admissions included in the study period was 378 487 persons, of which 14 262 (3.8%) were Syrian refugees. A total of 62 345 diagnoses (16.5%) were related to the respiratory system. Turkish patients had a significantly higher median age than Syrian refugees. Also, there were significantly more women among Syrian applicants, and acute bronchitis and asthma were more common among Syrian patients. However, the hospitalization rates were similar between the two groups. Moreover, Syrian patients had more applications during the summer seasons and had higher "Yellow" labels in the emergency triage. CONCLUSION: There are differences in the disease patterns of Syrian refugees and Turkish citizens applying to the emergency department. This may be explained by the difficulty in communication which, to our opinion, may be reversed as language barriers are overcome and adaptation to the society is completed over time.

Distraction osteogenesis is inhibited by cancer radiotherapy with Co 60.

AIM: To investigate the effects of radiotherapy on distraction osteogenesis performed on the same bone in an area that has not received radiation. Radiotherapy (Co60) was carried out in a region where tumors may develop, and then, on the assumption that the tumoral region had been removed, distraction osteogenesis was carried out, and the effects were investigated. METHOD: Thirty New Zealand rabbits were randomized into two groups, a study group (15 rabbits) and a control group (15 rabbits). In the study group, Co60 was administered by teletherapy to the distal half of the left tibia. Rabbits in the control group were kept in the same environment for the same period, but were not subjected to radiotherapy. Four weeks after radiotherapy, osteotomy was performed on the proximal part of the left tibia of all subjects, and distraction was carried out until 10mm. After distraction was completed, the outcomes were evaluated radiologically, scintigraphically, and histopathologically, and the results were compared. RESULTS: New bone formation achieved through distraction osteogenesis in the study group animals was inadequate, while new bone tissue achieved in the control group was superior (P < 0.001). CONCLUSION: Radiotherapy has a negative effect on distraction osteogenesis, even if performed on a different part of the bone.