Leman Tomak

An analytic approach to better understanding and management of coronary surgeries

Demand for high-quality, affordable healthcare services increasing with the aging population in the US. In order to cope with this situation, decision makers in healthcare (managerial, administrative and/or clinical) need to be increasingly more effective and efficient at what they do. Along with expertise, information and knowledge are the other key sources for better decisions. Data mining techniques are becoming a popular tool for extracting information/knowledge hidden deep into large healthcare databases. In this study, using a large, feature-rich, nationwide inpatient databases along with four popular machine learning techniques, we developed predictive models; and using an information fusion based sensitivity analysis on these models, we explained the surgical outcome of a patient undergoing a coronary artery bypass grafting. In this study, support vector machines produced the best prediction results (87.74%) followed by decision trees and neural networks. Studies like this illustrate the fact that accurate prediction and better understanding of such complex medical interventions can potentially lead to more favorable outcomes and optimal use of limited healthcare resources.

The management of cubitus varus and valgus using the Ilizarov method

Cubitus varus and valgus are the most common complications of supracondylar and lateral condylar fractures. Various combinations of osteotomy and fixation have been described to correct these deformities but each is associated with significant complications. In this study, we used distraction osteogenesis and Ilizarov frame fixation to treat 24 elbows in 23 patients with cubitus varus or valgus. Their clinical outcome was evaluated using the protocol of Bellemore et al. The mean time to follow-up was 18.3 months (10 to 36) and the mean time to frame removal was 13.5 weeks (8 to 20). The mean carrying angle was corrected from -18.7 degrees (-10 degrees to -30 degrees ) to 6.1 degrees (2 degrees to 10 degrees ) in patients with cubitus varus and from 36.5 degrees (25 degrees to 45 degrees ) to 9.4 degrees (4 degrees to 15 degrees ) in patients with cubitus valgus. There were 18 excellent and six good results. The Ilizarov method with gradual distraction is a safe, stable, adjustable and versatile method of treating deformities at the elbow without the problems of an unsightly scar or limited range of movement, and gives a good clinical and radiological outcome. Tardy ulnar nerve palsy should be treated first by anterior transposition.

Association between osteoporosis and polymorphisms of the bone Gla protein, estrogen receptor 1, collagen 1-A1 and calcitonin receptor genes in Turkish postmenopausal women.

In this study, we have investigated the association between osteoporosis and osteocalcin (BGLAP) -298 C>T, estrogen receptor 1 (ER1) 397 T>C, collagen type1 alpha 1 (Col1A1) 2046 G>T and calcitonin receptor (CALCR) 1340 T>C polymorphisms. Genomic DNA was obtained from 266 persons (158 osteoporotic and 108 healthy controls). Genomic DNA was extracted from EDTA-preserved peripheral venous blood of patients and controls by a salting-out method and analyzed by PCR-RFLP. As a result, there was no statistically significant difference in the genotype and allele frequencies of patients and controls for BGLAP -298 C>T, Col1A1 2046 G>T, ER1 397 T>C and CALCR 1340 T>C polymorphisms. However, ER1 CC genotype compared with TT+TC genotypes was found to increase the two fold the risk of osteoporosis [p=0.039, OR=2.156, 95% CI (1.083-4.293)] and CALCR CC genotype compared with TT+TC genotypes was found to have protective effect against osteoporosis [p=0.045, OR=0.471, 95% CI (0.237-0.9372)]. In the combined genotype analysis, ER1/CALCR TCCC combined genotype was estimated to have protective effect against osteoporosis [p=0.0125, OR=0.323, 95% CI (0.1383-0.755)] whereas BGLAP/Col1A1 CCTT and ER1/CALCR CCTT combined genotypes were estimated as risk factors for osteoporosis in Turkish population (p=0.027, p=0.009 respectively).

Treatment of U-shaped Bone Ankylosis of the Knee with the Ilizarov Method: A Case Report

Osseous ankylosis following thermal burns is an uncommon but disabling problem1,2. There are two different types of bone ankylosis. The first type is due to extra-articular bridging heterotopic ossification with preservation of the underlying joint. This type typically responds to physical therapy and other treatment modalities, including surgical excision. The second type of bone ankylosis is intraarticular and occurs most commonly at the interphalangeal joints, resulting in serious functional and cosmetic problems2. There are several alternatives for treatment, including arthrodesis, osteotomy, arthroplasty, and amputation. However, treatment is always very difficult and the outcomes can be discouraging2,3. We present the case of a patient who had intra-articular bone ankylosis of the right knee joint in full flexion that was treated with the Ilizarov method4,5. To our knowledge, this is the first time that such a case, in terms of both the clinical presentation and the method with which it was treated, has been reported in the literature. Our patient was informed that data from the case would be submitted for publication. Aforty-seven-year-old woman presented with a 160° fixed flexion deformity of the right knee that was very disabling. She had sustained a third-degree thermal burn involving the right lower extremity when she was seven years old. There was circumferential scarring of the skin about the knee, and the right thigh appeared to be adhered to the leg. She required the use of crutches for mobility. A lateral radiograph showed that the right femur and tibia were almost parallel to each other and the knee was ankylosed (Fig. 1). We …

Diagnostic performance of diffusion-weighted MRI in the diagnosis of ovarian torsion: comparison of torsed and nonaffected ovaries

INTRODUCTION The aim of this study was to evaluate the role of diffusion-weighted magnetic resonance imaging (MRI) in the diagnosis of ovarian torsion. METHODS We retrospectively identified 84 patients with surgically confirmed ovarian torsion. Seventeen patients with unclear ultrasound findings underwent MRI examination with two different magnetic resonance (MR) systems. RESULTS In ovarian torsion, the mean apparent diffusion coefficient (ADC) value of the torsed ovary was significantly lower than that of the nonaffected ovary in both MR systems (n=17; 0.898±0.539 vs. 1.615±0.469×10(-3)mm(2)/s; P<.001). CONCLUSIONS ADC comparisons were useful for detecting ovarian torsion.

ErbB receptor tyrosine kinase family expression levels in urothelial bladder carcinoma

ErbB receptor tyrosine kinases family plays an important role in cell cycle regulation. Overexpression of ErbB receptors has been described in several solid tumors. The aim of this study was to investigate the levels of ErbB1, ErbB2, ErbB3, and ErbB4 expression in bladder cancer. Urinary bladder tumor samples were obtained from 33 bladder cancers and 7 non-cancerous bladder biopsies. The levels of ErbB1, ErbB2, ErbB3, and ErbB4 genes expression in bladder cancer were determined by real-time PCR. The presence of protein was confirmed by immunostaining. Expression of ErbB1, ErbB2, ErbB3, and ErbB4 genes increased 0.67, 4.72, 2.89, and 2.65-fold, respectively, in bladder tumors as compared with normal tissue. There was a significant difference between immunostaining results of ErbB4 protein in bladder tumors and normal bladder tissue (P<0.01). The present data suggest that ErbB2, ErbB3, and ErbB4 genes may have a role in bladder cancer tumorigenesis.

Subtrochanteric Derotation Osteotomy Using a Bent Dynamic Compression Plate in Children With Medial Femoral Torsion

Subtrochanteric osteotomy of the femur using a bent dynamic compression plate is a simple, safe, and stable technique for correction of severe medial femoral torsion.

Contribution of 3-T Susceptibility-Weighted MRI to Detection of Intraarticular Hemosiderin Accumulation in Patients With Hemophilia

OBJECTIVE The purpose of this study was to assess the feasibility of 3-T susceptibility-weighted imaging (SWI) for detecting intraarticular hemosiderin accumulation in patients with hemophilia. SUBJECTS AND METHODS Forty-one joints in 24 patients with hemophilia were imaged with conventional MRI and SWI sequences. Two experienced musculoskeletal radiologists and one general radiologist (reader 3) interpreted the images for hemosiderin accumulation. The final decision was determined in consensus by readers 1 and 2 using both conventional MRI and SWI sequences. The diagnostic consistencies of each MRI sequence with the reference and pairwise agreements between interpreters were assessed. RESULTS For conventional MRI sequences, the diagnostic consistencies of the two experienced musculoskeletal radiologists with the reference were substantial (κ = 0.63 and 0.62), whereas the consistency of the general radiologist with the reference was moderate (κ = 0.47). The SWI interpretations of all readers had almost perfect agreement with the reference (κ = 1, κ = 1, κ = 0.97). Interobserver agreement also improved at SWI interpretations. CONCLUSION SWI contributes to more accurate grading of intraarticular hemosiderin accumulation than is achieved with conventional MRI sequences.

Serum human epididymis protein 4 levels in colorectal cancer patients

Tumour markers are widely used for the diagnosis, staging and monitoring of colorectal cancer (CRC) patients in clinical practice. Carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) are the most frequently used biomarkers in CRC patients. A number of studies have recently investigated the presence of human epididymis protein 4 (HE4) overexpression in certain cancer types. Its significance in ovarian and endometrial cancer has been well-demonstrated. The aim of the present study was to evaluate the significance of serum HE4 levels in CRC patients. A total of 46 newly diagnosed CRC patients and 36 age- and gender-matched healthy subjects were included in the study. The concentrations of CEA and CA19-9 were also determined and compared according to HE4 levels. HE4 positivity was determined in 13 of the 46 cases (28.3%) in the CRC group, but no HE4-positive subjects were identified in the control group (0%; P=0.009). The area under the receiver operating characteristic curve for HE4 positivity was 0.641 (95% CI: 0.523-0.760). HE4 was statistically significantly positive in patients with stage III-IV disease and in those with high CA 19-9 levels (all P<0.01). To the best of our knowledge, this is the first study to investigate HE4 expression in CRC patients, and the findings suggest that it may be a useful biomarker, particularly in stage III-IV patients.

Evaluation of Renal Parenchyma Elasticity With Acoustic Radiation Force Impulse Quantification in Nutcracker Syndrome and Comparisons With Grayscale Doppler Sonography and Laboratory Findings

We sought to evaluate renal parenchymal elasticity with Virtual Touch quantification of acoustic radiation force impulse imaging in nutcracker syndrome and to compare shear‐wave velocity (SWV) values with grayscale Doppler sonography and laboratory findings.