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Biomedical subjects

K Ozdemir

Publications and source records attributed to K Ozdemir.

17 recordsLinked to original sources
PubMed2006

Investigation of direct toxic and teratogenic effects of anticoagulants on rat embryonic development using in vitro culture method and genotoxicity assay.

Heparin and low molecular weight heparins (LMWHs) are used to reduce the incidence of venous thromboembolism in pregnancy. Although, these agents have been shown to be safe when used during pregnancy, the studies about direct toxic and teratogenic effects of these drugs on embryonic development are limited. In this study, the effects of heparin and LMWHs on rat embryonic development were investigated by using in vitro embryo culture and micronucleus (MN) assay methods. Rat embryos were cultured in vitro in the presence of different concentrations of heparin (5-40 IU/ml), dalteparin (2.5-20 IU/ml), enoxaparin (25-100 microg/ml) and nadroparin (1-4 IU/ml). Effects of anticoagulants on embryonic developmental parameters were compared and embryos were evaluated for the presence of any malformations. After culturing the embryos, classic MN assay was performed. Anticoagulants significantly decreased all growth and developmental parameters dose-dependently. Dalteparin and enoxaparin were found to cause more developmental toxicity than heparin and nadroparin. Along with haematoma in general, heparin and nadroparin caused maxillary deformity, situs inversus and oedema most frequently, while neural tube defects were observed with dalteparin and enoxaparin. All agents also significantly induced MN formation in rat embryonic blood cells. These results indicate the possible genotoxic effects of anticoagulant agents on the developing rat embryo when applied directly.

Abnormalities, Drug-Induced↗
PubMed2001

Usefulness of peak mitral inflow velocity to predict severe mitral regurgitation in patients with normal or impaired left ventricular systolic function.

BACKGROUND: The aim of this study was to evaluate the reliability of peak mitral inflow (E-wave) velocity, which was thought to be easier and more practical than qualitative and quantitative methods used to grade mitral regurgitation (MR) in patients both with normal and low left ventricular (LV) ejection fraction (EF). It is known that peak E-wave velocity increases in MR. But correlation of this increase with regurgitant fraction (RF), its usefulness in grading MR, and the effect of EF on peak E-wave velocity have not been studied in detail. METHODS: We prospectively examined 135 consecutive patients with varying grades of MR with echocardiography. MR was evaluated both qualitatively and quantitatively, and concordance of these 2 methods was determined. Peak E-wave velocity, A-wave velocity, and E-wave deceleration time were measured and the E/A ratio was calculated. LV isovolumetric relaxation and contraction times were measured. Different MR groups classified by RF were compared with each other. RESULTS: Concordance of quantitative and qualitative evaluation was low in patients with low EF (kappa 0.37 vs 0.65). Peak E-wave velocity and E/A ratio showed significant differences between MR groups. Peak E-wave velocity correlated with the RF and EF (r = 0.47, r = 0.33, respectively, P <.001). Sensitivity, specificity, and negative predictive value of peak E-wave velocity >1.2 m/s suggesting severe MR were found to be different in patients with normal and low EF (96% vs 66%, 78% vs 83%, 97% vs 78%, respectively). E-wave deceleration, LV isovolumetric relaxation, and contraction time did not show a correlation with RF. CONCLUSION: Peak E-wave velocity is a screening method that could be used in common for determining severity of MR semiquantitatively, especially in patients with normal EF.

Adult↗
PubMed2001

Effect of the isolated left bundle branch block on systolic and diastolic functions of left ventricle.

BACKGROUND: We planned this study to evaluate the effects of left bundle branch block (LBBB) on systolic and diastolic functions of left ventricle (LV) that have not previously been investigated in detail. MATERIAL AND METHODS: Forty-five cases diagnosed as isolated LBBB according to the standard electrocardiographic criteria (group I, mean age: 60 +/- 12 years) were taken as the case group and 65 cases with normal conduction system (group II, mean age 58 +/- 14 years) were taken as the control group. Echocardiography was performed to all patients and coronary angiography was performed to 21 patients in group I and 35 patients in group II. In addition to standard systolic and diastolic function parameters, isovolumetric relaxation time (IRT), isovolumetric contraction time (ICT), and ejection time (ET) were measured by echocardiography, and the myocardial performance index (MPI) [(IRT+ICT)/ET] was calculated. LV end-diastolic pressure was calculated for the patients undergoing coronary angiography. RESULTS: In group I, LV end-systolic diameter was greater (3.1 +/- 0.4 cm vs 2.8 +/- 0.4 cm, P <.001) and ejection fraction was lower (64% +/- 6% vs 68% +/- 6%, P <.001) than those of group II. Rapid filling deceleration time and rate was markedly different in group I (respectively, 133 +/- 50 ms vs 166 +/- 24 ms, P <.001; 608 +/- 291 cm/s(2) vs 383 +/- 116 cm/s(2), P <.001). In addition, it was found that LBBB caused shortening of LV diastolic period and ET markedly (respectively, 347 +/- 116 ms vs 394 +/- 106 ms, P =.03; 255 +/- 40 ms vs 294 +/- 21 ms, P <.001) and prolongation of IRT and ICT (respectively; 124 +/- 36 ms vs 91 +/- 16 ms, 96 +/- 35 ms vs 38 +/- 9 ms, P <.001). The MPI was predominantly higher in group I (0.89 +/- 0.29 vs 0.40 +/- 0.06, P <.001). Invasively determined LV end-diastolic pressure was found higher in group I (14 +/- 3 mm Hg vs 10 +/- 3 mm Hg, P <.001). CONCLUSION: A marked elevation of the LV MPI and end-diastolic pressure, parallel to changes of conventional echocardiographic parameters, in patients with isolated LBBB points out that LBBB causes marked deterioration on LV systolic and diastolic functions.

Adult↗
PubMed2001

Importance of left anterior hemiblock development in inferior wall acute myocardial infarction.

The aim of this study was to investigate the clinical and angiographic importance of left anterior hemiblock (LAHB) during acute inferior myocardial infarction (AIMI) by comparing patient groups with and without LAHB after AIMI. One hundred seventy-two patients (141 men and 31 women) between 28 and 84 years of age (mean 55 +/-10 years) with AIMI were included in the study. Patients were divided into 2 groups according to electrocardiogram (ECG) criteria: group I comprised 25 patients in whom ECG pattern characteristic of LAHB developed, group II comprised 147 patients without this pattern. According to the electrocardiogram, patients were placed in group I if the mean QRS axis was deviated to the left < 30 degrees in the frontal plane with the following pattern: increased S-wave voltage and decreased R-wave voltage in leads II, the appearance of a deep S-wave in lead II, and a terminal positive R-wave in lead aVR. Coronary angiography was performed within 2 weeks. A coronary stenosis was considered if the vessel diameter was narrowed by > 50%. The dominant coronary artery was classified as right or left or balanced. The left ventricular ejection fraction (LVEF) was calculated from left ventriculography. The mean age of the patients in group I was significantly higher (58 vs 54 years, p = 0.007), while the risk factors were similar in both groups. Left anterior descending (LAD) and multi-vessel coronary artery disease (CAD) were found to be significantly higher in group I compared with group 11 (80% vs 38%, p=0.0001; 84% vs 52%, p=0.001, respectively). The mean LVEF was found to be lower in group I (51% vs 56%, p=0.04). Peak creatine phosphokinase MB (CKMB) values were not different (216 vs 162 IU/L, p = 0.09). The frequency of left dominant or balanced coronary artery was determined to be higher in group I (44% vs 17%, p = 0.018). LAHB development during AIMI can be an indicator of LAD lesions, multivessel coronary artery disease, and impaired left ventricular systolic function.

Adult↗
PubMed2001

Usefulness of coronary angiography for assessing left ventricular systolic function.

OBJECTIVE: In previous echocardiographic studies, a correlation between ejection fraction of the left ventricle and change in the movement of the mitral annular ring was found. In the light of these studies, we planned to investigate the relationship between systolic shortening (SS) and percent of systolic shortening (PSS), calculated from the long axis frame in coronary angiography and left ventricular systolic function. METHODS AND RESULTS: One hundred and thirty-eight patients (40 men and 98 women; mean age 58 +/- 10 years) who had been referred for coronary angiography and left ventriculography were included in the study. Ejection fraction (EF) was calculated from left ventriculography obtained from 30 degrees right anterior oblique projection. Distance from the lower border of the ostium of the left coronary artery to the most apical border of the left anterior descending (LAD) artery was measured at end-systole (ES) and end-diastole (ED) using coronary angiography obtained from the same projection. SS as ED-ES and PSS as SS/ED were calculated. Correlation of SS and PSS with EF was calculated (EF = 13.7 + 4.8 x SS, r = 0.91, p < 0.001 and EF = 14.2 + 6.5 x PSS, r = 0.90, p < 0.01). SS < 7 mm (criterion A) and PSS < 6% (criterion B) suggested that left ventricle EF was less than 50%, with a sensitivity, specificity and diagnostic accuracy of 83%, 100%, 95%; 95%, 86% and 88%, respectively. CONCLUSION: SS and PSS highly significantly correlate with left ventricular EF. Therefore, left ventriculography could be omitted in selected patients undergoing coronary angiography if it is not necessary to define the anatomic structure of the left ventricle.

Adult↗
PubMed2001

A unique double right coronary artery abnormality.

Double right coronary artery is a very rare coronary artery abnormality. Two cases have been reported so far. In these cases, both right coronary arteries were giving the same branches, and originated from the same orifice. In our case, both right coronary arteries were giving different branches. We could not find such a case in the literature. Therefore, we consider our case a unique double right coronary artery abnormality.

Adult↗
PubMed2000

Complications associated with percutaneous placement of intra-aortic balloon counterpulsation: can unsheathed insertion reduce limb ischaemia?

Complications related to percutaneous placement of intra-aortic balloon pump counterpulsation are still high despite major refinements in catheter design and techniques. One hundred and forty-eight patients in whom intra-aortic balloon pumping was inserted were classified into two groups on the basis of the insertion technique. Group I included 103 patients in whom the conventional percutaneous insertion was used. A sheathless insertion technique was used in group II (n = 45). The overall complication rate was 16.6% (25 of 150), in which lower limb ischaemia was the most common complication. The limb ischaemia was noted in 12 patients (11.5%) in group I and 4 patients (8.9%) in group II (statistically not significant). Peripheral vascular disease, diabetes mellitus and female gender were found to be significant predictors of limb ischaemia (p = 0.01, p = 0.02 and p = 0.03, respectively). In conclusion, sheathless insertion of intra-aortic balloon pump catheters does not reduce the incidence of limb ischaemia.

Adult↗
PubMed1999

UHL's anomaly.

Uhl's anomaly is a rare congenital hypoplasia of the right ventricular (RV) myocardium. It can be seen together with some other congenital anomalies. Here we first report a 16-year-old male patient with Uhl's anomaly which appears with cardiac tamponade.

Adolescent↗
PubMed1999

Comparison of exercise stress testing with dobutamine stress echocardiography and radionuclide ventriculography for diagnosis of coronary artery disease.

Dobutamine stress echocardiography, Tc-99m radionuclide ventriculography (RNVG), and exercise stress testing were performed prospectively in 63 patients with suspected coronary artery disease to compare the values of exercise testing, dobutamine stress echocardiography and RNVG in the non-invasive diagnosis of coronary artery disease. The sensitivities of dobutamine stress echocardiography and RNVG were found to be higher than that of exercise testing (93-62%, p < 0.001; 83-62%, p < 0.05). The sensitivities of dobutamine stress echocardiography and RNVG were similar (p > 0.05). There were no differences between the sensitivities of the three techniques in multiple vessel disease (p > 0.05). The specificities of dobutamine stress echocardiography and RNVG were higher than that of exercise testing (for both of the tests 86-62%, p < 0.05). The diagnostic accuracy of dobutamine stress echocardiography and RNVG were similar (p > 0.05). The results of dobutamine stress echocardiography RNVG were concordant with each other in 46 patients (76%, kappa = 65%) in sectional analysis. Dobutamine stress echocardiography and RNVG tests were comparable with each other in 85% of the 189 segments (kappa = 64%). The expected 5% decrease at peak doses of dobutamine was not detected in stress echocardiography in 25 patients and in RNVG in 26 of the patients. Dobutamine stress echocardiography and RNVG are superior to exercise testing in the diagnosis of single vessel disease and there is no significant difference between the two techniques. When the ejection fraction is considered in dobutamine stress echocardiography and RNVG, it does not make an additional contribution to the diagnosis of coronary artery disease.

Adult↗
PubMed1999

Chlamydia trachomatis and male infertility: chlamydia-IgA antibodies in seminal plasma are C. trachomatis specific and associated with an inflammatory response.

BACKGROUND: There is controversy over the role of asymptomatic genital tract infection by Chlamydia trachomatis, its optimal diagnosis, and its place in the etiology of male infertility. OBJECTIVE: Comparison of direct detection of Chlamydia trachomatis in semen with the presence of chlamydia-antibodies in seminal plasma and serum, together with parameters of the spermatogram, in men of infertile relationships. STUDY DESIGN: Prospective clinical study. SETTING: University hospital tertiary referral center. SUBJECTS AND METHODS: Two groups of consecutive andrological patients (n = 89 and n = 36) were investigated as follows: semen analysis, including concentration of granulocyte-elastase; detection of C. trachomatis in semen samples and first void urine by polymerase chain reaction (PCR) and antigen-ELISA (Celisa); detection of chlamydia antibodies in serum and seminal plasma by recombinant antibody-enzyme-linked immunosorbent assay (rELISA) and of Chlamydia trachomatis specific antibodies by the ImmunoComb-Chlamydia-Bivalent test. RESULTS: In 2/125 (1.6%) semen samples Chlamydia trachomatis DNA was detected by PCR. Genus specific anti-chlamydia-IgA was found in 12/122 (9%) of the seminal plasmas. This IgA appeared to be specific for C. trachomatis. Seminal plasmas with chlamydia-IgA antibodies showed higher PMN-elastase levels than IgA negative samples (P < 0.04). Chlamydia-IgG antibodies were present in 27/89 (30%) of the sera, but in only five of these 27 sera (19%) were the antibodies detected specific for C. trachomatis. There were no associations between any of these variables and the parameters of the routine semen analysis. CONCLUSION: IgA-chlamydial antibodies in seminal plasma appeared to be specific against C. trachomatis and were associated with an inflammatory response in the male genital tract.

Adult↗
PubMed1997

Comparison of exercise stress testing with dobutamine stress echocardiography and exercise technetium-99m isonitrile single photon emission computerized tomography for diagnosis of coronary artery disease.

To compare the value of exercise electrocardiography with dobutamine stress echocardiography and exercise technetium-99m isonitrile single-photon emission computed tomography for coronary artery disease, 70 patients with either suspected or proven coronary artery disease underwent dobutamine stress echocardiography, exercise technetium-99m isonitrile single-photon emission computed tomography (mibi-SPECT) and treadmill exercise electrocardiography (ECG). Dobutamine echocardiography and exercise mibi-SPECT revealed a higher overall sensitivity than exercise testing (90 vs 57%, p < 0.001; 96 vs 57%, p < 0.001, respectively). Dobutamine stress echocardiography showed a higher specificity than both exercise mibi-SPECT and treadmill exercise electrocardiography (90 vs 71%, p > 0.05; 90 and 62% p < 0.05, respectively) but the difference between dobutamine stress echocardiography and exercise mibi-SPECT was not statistically significant. Diagnostic accuracy of dobutamine stress echocardiography and exercise mibi-SPECT was higher than that of exercise testing (90 vs 59%, p < 0.001; 89 vs 59%, p < 0.001, respectively). Dobutamine stress echocardiography and exercise mibi-SPECT have superiority over exercise testing in the diagnosis of coronary artery disease and dobutamine stress echocardiography is an alternative for exercise mibi-SPECT.

Adult↗
PubMed1996

Comparison of exercise stress testing with simultaneous dobutamine stress echocardiography and technetium-99m isonitrile single-photon emission computerized tomography for diagnosis of coronary artery disease.

The object of our study was to compare the value of exercise stress testing with simultaneous dobutamine stress echocardiography and technetium-99m isonitrile single-photon emission computed tomography for the diagnosis of coronary artery disease. Sixty-nine patients with either suspected or proven coronary artery disease underwent simultaneous dobutamine technetium-99m isonitrile single-photon emission computed tomography and stress echocardiography, and treadmill exercise electrocardiography. Dobutamine echocardiography and technetium-99m isonitrile single-photon emission computed tomography revealed a higher overall sensitivity than exercise testing (94 vs 60%, P < 0.001), but dobutamine stress echocardiography showed a higher specificity than both technetium-99m isonitrile single-photon emission computed tomography and exercise testing (86 vs 64%, P < 0.05, for both tests). In addition, the diagnostic accuracy of dobutamine stress echocardiography and technetium-99m isonitrile single-photon emission computed tomography was higher than that of exercise testing (91 vs 61%, P < 0.001; 86 vs 61%, P < 0.001, respectively). Dobutamine stress echocardiography and technetium-99m isonitrile single-photon emission computed tomography are superior to exercise testing in the diagnosis of coronary artery disease, and dobutamine stress echocardiography can act as an alternative to technetium-99m isonitrile single-photon emission computed tomography.

Adult↗
PubMed1991

The validation of a computerized system for the interpretation of the antepartum fetal heart rate tracings (version 89/2.34).

We have developed a knowledge-based system for the interpretation of the antepartum fetal heart rate tracings. This study consists of four groups of patient: (1) 49 normal pregnancies with a normal perinatal outcome; (2) 13 normal pregnancies with abnormal perinatal outcome; (3) 33 high-risk pregnancies with abnormal perinatal outcome; and (4) 16 high-risk pregnancies with normal perinatal outcome. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of our expert system (version 89/2.34) were estimated to be 60.0, 85.7, 75.0 and 75.0%, respectively. When the normal pregnancies with abnormal outcome and the high-risk pregnancies with normal outcome were excluded from the population, sensitivity, specificity, PPV and NPV were calculated to be 57.7, 82.9, 68.2 and 75.6%, respectively (corrected values). The prevalance of abnormal outcome for this study was 41.7%.

Cardiotocography↗
PubMed1990

Computerized analysis of antepartum fetal heart rate tracings in normal pregnancies (version 88/2.29).

A computerized system is developed for the interpretation of antepartum fetal heart-rate monitoring. Various parameters are described to define the cardiotocograms. The pattern of the tracing is defined as saltatory, undulatory, reduced undulatory or silent according to the results of the spectrum analysis. Three different baselines including simple average baseline, real baseline and basecurve are described for each tracing. Spontaneous and fetal movement related accelerations and decelerations are also defined. Tracings from 33 normal pregnancies with normal outcome were studied and the distribution of parameters for each gestational week (28th to 40th) was defined. The real baseline of fetal heart rate was 141.5 +/- 8.5 between the 28th and 40th gestational week. 75% of the cardiotocograms were found to obtain fetal movement. It has also been observed that in normal pregnancies the general pattern of the tracings is undulatory or undulatory/saltatory.

Female↗
PubMed1990

Development and application of a simple expert system for the interpretation of the antepartum fetal heart rate tracings (version 88/2.29).

A simple expert system is developed for the interpretation of antepartum fetal heart rate tracings. The perinatal expert chose to use the phrase 'Fetal Reserve' to describe what the cardiotocogram is indirectly measuring. Our analysis program gives numerical values to each CTG such as 5, 4, 3, 2.5, 2 and 1 corresponding to the fetal reserve conditions of good, satisfactory, probably satisfactory with uncertainty, borderline, decreased, and critical respectively. This study consists of 33 normal pregnancies with normal outcome. Each patient is followed by our computerized system biweekly from the 28th to the 38th gestational week and weekly there after. The expert system's decision for 28th, 30th, 32nd, 34th, 36th, 38th, 39th and 40th gestational weeks were 3.3 +/- 1.0, 3.8 +/- 0.7, 3.8 +/- 1.0, 4.1 +/- 0.9, 4.1 +/- 0.7, 3.6 +/- 1.0, 4.2 +/- 1.0, 3.8 +/- 0.9 and 3.4 +/- 1.2, respectively. In this study, we have used confusion matrix to determine the normal, security, and danger zones according to the perinatal expert and the expert system and the discriminatory power of the system is found to be highly significant statistically (Q = 221). We also showed that the passive test (non-stress test) in normal pregnancies has demonstrated false positive results in 4.2 and 9.3% of the cases according to the evaluations of the perinatal expert and the expert system, respectively.

Expert Systems↗