A Comparative 3D Finite Element Computational Study of Stress Distribution and Stress Transfer in Small-Diameter Conical Dental Implants

The implant design is one of the main factors in implant stability because it affects the contact area between the bone and the implant surface and the stress-strain distribution at the bone-implant interface. In this study, the effect of different groove geometries on stress-strain distributions in small-diameter conical implants is investigated using the finite element method (FEM). Four different thread models (rectangular, buttressed, reverse buttressed, and symmetrical profile) are created by changing the groove geometry on the one-piece implants, and the obtained results are compared. The stress shielding effect is investigated through the dimensionless numbers that characterize the load-sharing between the bone-implant. It is determined that the lowest stress distribution is observed with rectangular profiled groove geometry. Besides, it is obtained that the buttressed groove geometry minimizes the stress effects transmitted to the periphery of the implant. The symmetrical profiles had better performance than rectangular profiles in stress transfer

Investigation of relationship between IL-6 gene variants and hypertension in Turkish population

Hypertension (HT) is a common and life threating health problem worldwide leading to stroke, heart attack and renal failure. It is characterized by elevated blood pressure forced heart load. Human interleukin-6 (IL-6) and C- reactive protein (CRP) are known to be involved in inflammatory processes. IL-6 gene is a polymorphic gene which -174 G/C is a common and -572 G/C is a rare polymorphisms identified in promoter region. Publications on IL-6 gene polymorphisms raised the question whether this gene polymorphisms lead to susceptibility to HT or not. To investigate the effects of IL-6 gene -174 G/C (rs 1800795) and -572 G/C (rs1800796) polymorphisms on plasma IL-6 and CRP levels and their associations with hypertension disease in Turkish population we analyzed -174 G/C and -572 G/C polymorphisms and plasma IL-6 and CRP levels in 111 healthy controls and 108 hypertension patients from Adyaman, Turkey. We determined the genotypes using polymerase chain reaction-restriction fragment length polymorphism and analyzed plasma levels of IL-6 by ELISA and CRP by automated standard biochemical methods. We have found no statistically significant differences between IL-6 gene -174 G/C and -572 G/C genotypes and allelic frequencies and IL-6 and CRP plasma levels and HT (p > 0.05). No CC genotype was found in control subjects for -572 G/C polymorphism. In conclusion, we found relation to -174 G/C and -572 G/C gene variants between neither IL-6 and CRP levels nor hypertension. The -572 G allele and GG genotype are predominant in Turkish population in Adyaman, Turkey whereas the CC genotype is very rare.This study was supported by a grant of the Research Foundation of Adiyaman University (FEFYL/2012-0002), Turkey

High prevalence of NDM metallo-β-lactamase among ESBL-producing Escherichia coli İsolates

Resistance to β-lactams in Enterobacteriaceae has been increasing worldwide. This study aimed to determine the frequency of β-lactamase genes and antibiotic resistance rates of 140 extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates obtained from urinary tract infection in Ordu Province, Turkey. Isolates were identified by classic methods and by automated system. ESBL production was confirmed by double disk synergy test and antimicrobial susceptibility was investigated by disk diffusion method. All isolates were screened for β-lactamase coding genes from three groups (A, B, and D) by polymerase chain reaction. The highest rate of susceptible isolates was observed for imipenem (IPM, 99.3%) and ertapenem (ETP, 97.9%), and the highest rate of resistant isolates was observed for cefuroxime (97.9%), ceftriaxone (97.2%), and cefazolin (90.7%). In our study, blaCTX-M1-like group was the most prevalent β-lactamase (n = 109), followed by blaTEM (n = 68), blaCTX-M2 (n = 22), and blaSHV (n = 2). By contrast to low resistance rate to IPM and ETP, we determined blaNDM in 31 isolates (22.1%). In co-prevalence of blaNDM-1 and ESBL-coding genes, a low carbapenem resistance was determined. We can confirm that blaCTX-M1-types are still the most frequent β-lactamase coding gene in Turkey. Our study showed the highest prevalence of blaNDM-1 metallo-β-lactamase coding gene in ESBL-producing E. coli

Talyum sintigrafisi sonrası hipokalemiye bağlı ventriküler fibrilasyon gelişen bir olgu

A 44 year old man who had kidney transplantation was hospitalized to orthopedia clinic for total hip prosthesis due to his coxarthrosis. In his preoperative evaluation, he had diarrhea for three days, and he had a chest pain that lasted less than 20 minutes which was not related with effort. According to cardiology consultation the patient was applied myocard perfussion scintigraphy with thallium. After the scintigraphy, a sudden cardiac arrest occured. He was monitorized after having orotracheal intubation. Since he was in ventricular fibrillation, he was defibrillated. According to the ERC criteria cardiac compressions were continued. Because of resistant ventricular fibrillation and hypokalemia at the 15th minute of cardiac resusitation, 20 mmol l -1 KCl and 12 mmol l -1 magnesium were administered within five minutes. After these applications sinus rythm was achieved and the patient was transfered to the cardiology service and he was followed up there. Hypokalemia exists in the electrolyte imbalances that cause ventricular dysrhythmias. Occurance of hypokalemia in patients with diarrhea and gastrointestinal disorders should be kept in mind during the anesthetic evaluation. In addition, hypokalemia can become deeper as a consequence of thallium scintigraphy that can result with resistant ventricular dysrhythmias.Olgu, (44 yaşında, erkek) böbrek transplantlı, koksartroz tanısıyla total kalça protezi planlanarak ortopedi kliniğine yatırıldı. Hastanın preoperatif anestezi değerlendirilmesinde üç gündür devam eden diyare ve son birkaç gündür 20 dakikadan kısa süren eforla ilişkisiz göğüs ağrısı mevcuttu. Kardiyoloji konsültasyonu doğrultusunda hastaya talyumlu miyokard perfüzyon sintigrafisi çekildi. Sintigrafi sonrası hastada hipokalemiye bağlı ani kardiyak arrest gelişti. Hasta orotrakeal entübe edilerek monitorize edildi. Hastanın ritminin ventriküler fibrilasyon olması üzerine defibrile edilerek, ERC kriterlerine göre kardiyak kompresyonlara devam edildi. Dirençli ventriküler fibrilasyonlar ve kan potasyum düzeyinin düşük olması nedeniyle resüsitasyonun 15. dakikasında20 mmol l-1 KCl ve 12 mmol l-1 Magnezyum 5 dakikada infüze edildi. Sinüs ritmi sağlanan hasta kardiyoloji servisinde izlendi.Hipokalemi ventriküler disritmilere neden olan elektrolit bozuklukları arasında yer alır. Preanestezik muayanede diüretik kullanan ve gasrointestinal bozuklukları olan hastalarda hipokalemi gelişebileceği akılda tutulmalıdır. Ayrıca hipokalemisi olan hastaların talyum miyokard sintigrafisi sonrası hipokalemileri daha da derinleşebilir ve bunun sonucunda dirençli ventriküler disritmiler gelişebilir

ANESTHETIC MANAGEMENT OF A PATIENT WITH A FEMUR FRACTURE AND VENTRICULAR ASSIST DEVICE

Mekanik kalp desteği, hemodinamik bozukluğu, kronik konjestif kalp yetmezliği olan hastalarda tıbbi tedaviye bir alternatiftir. Mekanik ventrikül destek cihazları; bozulmuş ventrikül fonksiyonunu destekleyerek yeterli kardiyak debi sağlarlar ve uç organ fonksiyonlarının düzelmesine yardımcı olurlar. Bu cihazların miyokardit gelişen veya miyokard fonksiyonları olmayan kalp transplantasyonuna aday son dönem kardiyomiyopatili hastalarda miyokard fonksiyonunu artırması beklenir. Bu olguda 67 yaşında femur fraktürü gelişen ve kalp tranplant adayı olan, dilate kardiyomiyopatisi nedeniyle pulsatil olmayan sol ventrikül destek cihazı uygulanan hastamızda uyguladığımız non kardiyak anestezi uygulamamızı sunmayı amaçladık. Kanama diyatezi ve pulsatil olmayan ventriküler cihazı olması nedeniyle hastamıza radyal arter kateteri, juguler santral venöz kateter ve analjezi amacıyla femoral sinir bloğu ile lateral femoral kutanöz sinir bloğu ultrasonografi rehberliğinde uygulandı.Mechanical cardiac support is an alternative to medical treatment in hemodynamic disturbances in patients with chronic congestive heart failure. Mechanical ventricular assist devices are used to provide support for impaired ventricular functions and they help to regulate end-organ functions by providing sufficient cardiac output. Ventricular assist devices are used to improve myocardial functions of patients with myocarditis, or they are used for patients who are candidates for cardiac transplantation whose myocardial functions are not expected to improve such as patients with end-stage cardiomyopathy. In this case, we present the anesthetic management of a 67-year-old patient with a left ventricular assist device who was a candidate for cardiac transplantation because of dilated cardiomyopathy and who underwent noncardiac surgery due to femur fracture. As the patient had a non-pulsatile ventricular assist device and bleeding diathesis, a radial artery catheter and a jugular central venous catheter were placed with ultrasound guidance. Besides, femoral nerve block and lateral femoral cutaneous nerve block were performed with ultrasound guidance for intraoperative and postoperative analgesia