Determining and Managing Fetal Radiation Dose from Diagnostic Radiology Procedures in Turkey

Mustafa Ozbayrak,Iffet Cavdar,Mehmet Seven,Lebriz Uslu,Nami Yeyin,Handan Tanyildizi,Mohammad Abuqbeitah,A. Serdar Acikgoz,Abdullah Tuten,Mustafa Demir 대한영상의학회 2015 Korean Journal of Radiology Vol.16 No.6

We intended to calculate approximate fetal doses in pregnant women who underwent diagnostic radiology procedures and to evaluate the safety of their pregnancies. We contacted hospitals in different cities in Turkey where requests for fetal dose calculation are usually sent. Fetal radiation exposure was calculated for 304 cases in 218 pregnant women with gestational ages ranging from 5 days to 19 weeks, 2 days. FetDose software (ver. 4.0) was used in fetal dose calculations for radiographic and computed tomography (CT) procedures. The body was divided into three zones according to distance from the fetus. The first zone consisted of the head area, the lower extremities below the knee, and the upper extremities; the second consisted of the cervicothoracic region and upper thighs; and the third consisted of the abdominopelvic area. Fetal doses from radiologic procedures between zones were compared using the Kruskal-Wallis test and a Bonferroni-corrected Mann-Whitney U-test. The average fetal doses from radiography and CT in the first zone were 0.05 ± 0.01 mGy and 0.81 ± 0.04 mGy, respectively; 0.21 ± 0.05 mGy and 1.77 ± 0.22 mGy, respectively, in the second zone; and 6.42 ± 0.82 mGy and 22.94 ± 1.28 mGy, respectively, in the third zone (p < 0.001). Our results showed that fetal radiation exposures in our group of pregnant women did not reach the level (50 mGy) that is known to increase risk for congenital anomalies. Fetal radiation exposure in the diagnostic radiology procedures in our study did not reach risk levels that might have indicated abortion.

Effects of 1-Methylcyclopropene (1-MCP) and Modified Atmosphere Packaging (MAP) on Storage Life of Avocado Fruit

Mustafa Pekmezci,Mustafa Erkan,Isilay Karasahin,Aliye Demirkol,Huseyin Uslu 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

New Elastoplastic Analysis of Two-Dimensional Frames When Some Plastic Hinges Unload Elastically

Fethullah Uslu,Mehmet Tevfik Bayer,Mustafa Haluk Saraçoğlu 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.2

Two-dimensional frames are made of elastic and perfectly plastic materials. Frames are analized by using the step by step elastoplastic analysis method where the applied loads are gradually increased at each step until a plastic hinge is developed. Then an equivalent frame model is generated by placing a mechanical hinge at the location of the plastic hinge and the increased external loads and the reduced plastic moments acting at the plastic hinge sections are applied to this model and elastoplastic analysis is performed. This elastoplastic analysis is repeated by incrementally increasing the external loads and applying the new reduced plastic moments, until the next plastic hinge is developed. Then a new equivalent frame model is generated to search for the following plastic hinge. This step by step elastoplastic analysis continues until the frame partially or totally collapses. When a plastic hinge is developed, it means that the section is at a fully plastic stress state. In the following small load increment: if this fully plastic stress state moves to another fully plastic stress state then this movement is called plastic fl ow. But if this fully plastic stress state moves to an elastic–plastic stress state then this movement is called elastic unloading. During the search of the next plastic hinge if one of the plastic hinges begins to unload elastically then the current equivalent frame model must be revised. For this the frame member which contains the elastically unloading plastic hinge is replaced by the equivalent frame member carrying balancing loads.

True Collapse Mechanisms of Two Dimensional Frames Determined from True Nonlinear Yield Surfaces

Fethullah Uslu,Mehmet Tevfik Bayer,Mustafa Haluk Saraçoğlu 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.1

In this work, collapse mechanisms and collapse load factors of two-dimensional frames which are subject to point loads and uniformly distributed loads are determined by employing new elastoplastic analysis method. In this new iterative method as the applied loads on frames are gradually increased, plastic hinges begin to develop at frame member sections and this continues until the partial or total collapse occurrence. If a plastic hinge develops at a section of a frame member, then a mechanical hinge is defined at this location and at each iteration reduced plastic moments are also applied as external loads. This is a new approach to search for the next plastic hinge where a series of linear elastoplastic analyses are executed. For each analysis the revised reduced plastic moments are used in the calculations. For elastoplastic calculations of two-dimensional frames, yield surface definitions of frame member sections are needed, and for I sections, yield surfaces are defined by two curves. In order to simplify collapse load factor calculations these yield surfaces are generally approximated by two lines. In this work the influences of the approximations on the elastoplastic behaviour of two-dimensional frames are examined by comparing the solutions of four example frames. When their solutions are compared, it is observed that almost equal collapse load factors are determined when true and approximate yield surfaces are used in the elastoplastic calculations but true collapse mechanisms are obtained only when true nonlinear yield surfaces are used.

Comparison of the cyclic fatigue resistance of VDW.ROTATE, TruNatomy, 2Shape, and HyFlex CM nickel-titanium rotary files at body temperature

Gundogar, Mustafa,Uslu, Gulsah,Ozyurek, Taha,Plotino, Gianluca The Korean Academy of Conservative Dentistry 2020 Restorative Dentistry & Endodontics Vol.45 No.3

Objectives: This study aims to compare the cyclic fatigue resistance of VDW.ROTATE, TruNatomy, 2Shape, and HyFlex CM nickel-titanium (NiTi) rotary files at body temperature. Materials and Methods: In total, 80 VDW.ROTATE (25/0.04), TruNatomy (26/0.04), 2Shape (25/0.04), and HyFlex CM (25/0.04) NiTi rotary files (n = 20 in each group) were subjected to static cyclic fatigue testing at body temperature (37℃) in stainless-steel artificial canals prepared according to the size and taper of the instruments until fracture occurred. The number of cycles to fracture (NCF) was calculated, and the lengths of the fractured fragments were measured. The data were statistically analyzed using a 1-way analysis of variance and post hoc Tamhane tests at the 5% significance level (p < 0.05). Results: There were significant differences in the cyclic fatigue resistance among the groups (p < 0.05), with the highest to lowest NCF values of the files as follows: VDW.ROTATE, HyFlex CM, 2Shape, and TruNatomy. There was no significant difference in the lengths of the fractured fragments among the groups. The scanning electron microscope images of the files revealed typical characteristics of fracture due to cyclic fatigue. Conclusions: The VDW.ROTATE files had the highest cyclic fatigue resistance, and the TruNatomy and 2Shape files had the lowest cyclic fatigue resistance in artificial canals at body temperature.

Effects of Epinephrine and Cortisol on the Analgesic Activity of Metyrosine in Rats

Yavuz Albayrak,Mustafa Bahadir Saglam,Kadir Yildirim,Saliha Karatay,Beyzagul Polat,Turan Uslu,Fatih Akcay,Halis Suleyman 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.9

Some endogenous hormones (epinephrine and cortisol) can change an individual’s pain threshold. Propranolol is a non-selective β adrenergic receptor blocker which antagonises the antiinflammatory effect of non-steroidal anti-inflammatory drugs via the β1 and β2 adrenergic receptors. The roles of epinephrine and cortisol were investigated in the analgesic activity of metyrosine in rats with reduced epinephrine levels induced by metyrosine. Pain threshold measurement was performed using an analgesimeter with different doses and the single or combined usage of metyrosine, prednisolone, metyrapone and propranolol in rats. Epinephrine and corticosterone levels were measured by high-performance liquid chromatography in metyrosine-administered rats. Metyrosine reduces the epinephrine levels without affecting the corticosterone levels, thereby creating an analgesic effect. It was determined that prednisolone did not have an analgesic effect in rats with normal epinephrine levels, but its analgesic activity increased with a parallel decrease in the epinephrine levels. Similarly, the combined use of prednisolone and metyrosine provided a stronger analgesic effect than that rendered by metyrosine alone. The strongest analgesic effect, however, was observed in the group of rats with the lowest epinephrine level in whom the metyrosine + prednisolone combination was administered. The findings of this study may be useful in severe pain cases in which the available analgesics are unable to relieve the individual’s pain.

Butterfly Cartilage Tympanoplasty Long-term Results: Excellent Treatment Method in Small and Medium Sized Perforations

Isa Kaya,Murat Benzer,Mustafa Uslu,Cem Bilgen,Tayfun Kirazli 대한이비인후과학회 2018 Clinical and Experimental Otorhinolaryngology Vol.11 No.1

Objectives. The aim of this study was to evaluate and report the long-term results of the butterfly cartilage tympanoplasty. Short-term and long-term hearing outcomes were compared according to age and perforation location as well. Methods. Ninety-three patients who were diagnosed with noncomplicated chronic otitis media and underwent microscopic transcanal butterfly cartilage tympanoplasty due to anterior, posterior, and central tympanic membrane perforation were included. Age, gender, follow-up time, pre- and postoperative pure tone audiometry thresholds (both air and bone conduction), pre- and postoperative air-bone gaps (ABGs), if any residual perforation was noted. Results. At the end of the follow-up period, successful closure occurred in 88 of 93 patients and success rate is 94.6%. In all patients, including those with residual perforations, the mean preoperative bone conduction threshold was 15.9 dB (range, 5 to 50 dB) among all groups whereas mean air conduction threshold was 36.4±15.1 dB (range, 10 to 90 dB) preoperatively and 28.8±14.3 dB in 6th month follow-up and 24.9±14.1 dB 24th month follow-up. Preoperative mean ABG was 22.1±7.1 dB (range, 5 to 40 dB) whereas 13.3±5.9 dB 6 months after surgery and 11.9±5.5 dB 24 months after surgery. There was a significant difference between pre- and postoperative ABG in both 6th and 24th month follow-up (P6 mo–24 mo<0.05). Furthermore, preoperative mean air conduction differed significantly from postoperative 6th and 24th month follow-up mean air conduction thresholds (P<0.05). Conclusion. We suggested that butterfly cartilage tympanoplasty can be safely performed in small, moderate, and even large perforations, as the hearing outcomes and successful closure rate are similar to those of other surgical methods. Moreover, it can be performed under local anaesthesia and it has low complication rates.

Poster Session:PS 0481 ; Nephrology : Analgesic Nephropathy Associated with Total Anuria

( Yaloin Onem ),( Ali Kutlu ),( Seyit Ahmet Uslu ),( Barbaros Basbug ),( Muslum Sagir ),( Yusuf Hazcerli ),( Mustafa Hatipoglu ),( Kemal Kara ),( Ramazan Arikan ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Introduction and Aim:While ischemia and nefrotoxins account for almost 45 % of all acute renal failure cases, prerenal (caused by congestive cardiac failure, liquid insuffi - ciency, sepsis and medication) azotemia accounts for around 20%. Among nefrotoxins, nonstereoid anti-infiammatory drugs (NSAII) may affect kidneys through multiple mechanisms (causing hemodynamic, acute allergic interstitial nephritis, papillary necrosis or glomerular nephritis). Herein, we present a patient who developed analgesic nephropathy associated with total anuria. Case: A patient with a medical history of benign prostatic hyperplasia, coronary artery disease, hypertension and tuberculosis was admitted to our department of emergency with complaints of dyspnea and headache. Laboratory examination revealed the following Results: urea: 138 mg/dL, kreatinin: 5,20 mg/dL, BK: 19300, ALT: 319 U/L AST: 324 U/ L LDH: 1947 U/L. The patient was diagnosed with total anuria. Because the patient had a history of analgesic usage, he was scheduled to undergo hemodialysis 3 times per week with a prediagnosis of analgesic nephropathy. Although initially renal function tests demonstrated a slight deterioration (urea: 177 mg/dL and creatinine: 8 mg/dL) they displayed a gradual decrease following ongoing hemodialysis sessions and consequently returned to normal (urea: 48 mg/dL and creatinine: 1, 25 mg/dL). The patient also received piperacillin/tazobactam 3x 2, 25 gr/day due to a concern for aspiration pneumonia. Diagnostic bronchoscopy results were in compliance with fi brosis at microscopic level. Conclusion/Recommendations: Analgesic nefropathy should be investigated when inquiring for the etiology of acute renal failure. Patients with total anuria should receive comprehensive treatment comprising renal replacement therapy such as hemodialysis. Additionally, interstitial lung disease and overlapping aspiration pneumonia may complicate the condition. Therefore, they also should be considered. Even patients with total anuria may return to normal life following a comprehensive and rigorous approach.

Hepatitis B and C Seroprevalence in Solid Tumors - Necessity for Screening During Chemotherapy

Oguz, Arzu,Aykas, Fatma,Unal, Dilek,Karahan, Samet,Uslu, Emine,Basak, Mustafa,Karaman, Ahmet Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.3

Background: Hepatitis B and C are the leading causes of liver diseases worldwide. For hematological and solid malignancy patients undergoing chemotherapy, increases in HBV DNA and HCV RNA levels can be detected which may result in reactivation and hepatitis-related morbidity and mortality. The aim of this study was to determine the seroprevalence of Hbs ag and Anti HCV positivity in patients with solid malignancies undergoing chemotherapy and consequences during follow-up. Materials and Methods: The files of 914 patients with solid malignancies whose hepatitis markers were determined serologically at diagnosis were reviewed retrospectively. All underwent adjuvant/palliative chemotherapy. For the cases with HBV and/or HCV positivity, HBV DNA and HCV RNA levels, liver function tests at diagnosis and during follow-up and the treatment modalities that were chosen were determined. Results: Of 914 cases, Hbs Ag, anti Hbs and anti HCV positivity were detected in 40 (4.4%), 336 (36.8%) and 26 (2.8%) of the cases respectively. All of the Hbs ag positive patients received prophylactic lamuvidine before the start of chemotherapy. In the Hbs ag and anti HCV positive cases, liver failure was not detected during chemotherapy and a delay in chemotherapy courses because of hepatitis was not encountered. Conclusions: Just as with hematological malignancies, screening for HBV and HCV should also be considered for patients with solid tumors undergoing chemotherapy. Prophylactic antiviral therapy for HBV reduces both the reactivation rates and HBV related mortality and morbidity. The clinical impact of HCV infection on patients undergoing chemotherapy is still not well characterized.

First-Line Mono-Chemotherapy in Frail Elderly Patients with Metastatic Colorectal Cancer

Varol, Umut,Dirican, Ahmet,Yildiz, Ibrahim,Oktay, Esin,Degirmenci, Mustafa,Alacacioglu, Ahmet,Barutca, Sabri,Karabulut, Bulent,Uslu, Ruchan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.7

Background: Unlike for fit elderly metastatic colorectal cancer (mCRC) patients, general approaches to initial treatment for the frail older mCRC patients are not clear. Our aim was to evaluate the efficiency and safety of first-line single-agent treatment in one such group. Materials and Methods: We retrospectively evaluated mCRC patients aged 70 or older with an Eastern Cooperative Oncology Group performance score of 2. They had no prior treatment and underwent first-line single-agent capecitabine or other monotherapies until disease progression or unacceptable toxicity. Results: Thirty-six patients were included. Most (n:28, 77.8%) were treated with capecitabine. One patient achieved a complete response and 5 patients had a partial response for an overall response rate of 16.6%. Twelve patients (33.3%) remained stable. Median progression free survival was 5 months (confidence interval (CI), %; 3.59-6.40) and median overall survival was 10 months (95 CI%; 8.1-11.8). Grade 3-4 toxicity was found in 6 patients (16.6%). Febrile neutropenia was not observed and there were no toxicity-associated deaths. Conclusions: Capecitabine is a safe chemotherapeutic agent with moderate activity for first-line treatment of older metastatic colorectal cancer patients with limited performance status.