Yuksel Terzi

Comparison of a Newly Developed Automated and Quantitative Hepatitis C Virus (HCV) Core Antigen Test with the HCV RNA Assay for Clinical Usefulness in Confirming Anti-HCV Results

ABSTRACT Hepatitis C virus (HCV) is a global health care problem. Diagnosis of HCV infection is mainly based on the detection of anti-HCV antibodies as a screening test with serum samples. Recombinant immunoblot assays are used as supplemental tests and for the final detection and quantification of HCV RNA in confirmatory tests. In this study, we aimed to compare the HCV core antigen test with the HCV RNA assay for confirming anti-HCV results to determine whether the HCV core antigen test may be used as an alternative confirmatory test to the HCV RNA test and to assess the diagnostic values of the total HCV core antigen test by determining the diagnostic specificity and sensitivity rates compared with the HCV RNA test. Sera from a total of 212 treatment-naive patients were analyzed for anti-HCV and HCV core antigen both with the Abbott Architect test and with the molecular HCV RNA assay consisting of a reverse transcription-PCR method as a confirmatory test. The diagnostic sensitivity, specificity, and positive and negative predictive values of the HCV core antigen assay compared to the HCV RNA test were 96.3%, 100%, 100%, and 89.7%, respectively. The levels of HCV core antigen showed a good correlation with those from the HCV RNA quantification (r = 0.907). In conclusion, the Architect HCV antigen assay is highly specific, sensitive, reliable, easy to perform, reproducible, cost-effective, and applicable as a screening, supplemental, and preconfirmatory test for anti-HCV assays used in laboratory procedures for the diagnosis of hepatitis C virus infection.

Comparison of the Diagnostic Accuracy of Five Different Stool Antigen Tests for the Diagnosis of Helicobacter pylori Infection

Several noninvasive diagnostic tests based on the detection of Helicobacter pylori stool antigen (HpSA) have been developed. The aim of the study was to compare the diagnostic accuracy of 5 HpSA tests—2 monoclonal enzyme immunoassay tests (EIAs: the Premier Platinum HpSA Plus test and Helicobacter pylori Antigen (Hp Ag) test) and 3 rapid immunochromatographic assay (ICA) tests (the ImmunoCard STAT! HpSA test, one step HpSA test, and H. pylori fecal antigen test)—for diagnosing H. pylori infection in adult patients with dyspeptic symptoms before eradication therapy.

Reliability and validity of the Turkish version of the Falls Efficacy Scale International (FES-I) in community-dwelling older persons.

The FES-I is a questionnaire which was developed to assess fear of falling. The aim of this study was to evaluate validity and reliability of a Turkish language version of the FES-I in Turkish older people. The study sample included 70 volunteers with an age range of 65-81. To assess the test-retest reliability of the Turkish FES-I, questionnaire was applied again 10-15 days after the first interview (interclass correlation: ICC). FES-I was compared with The Modified Barthel Index (MBI), the timed up and go test (TUG), and The Berg Balance Scale (BBS) for construct validity. Cronbachs alpha (α) was used to evaluate the internal consistency. The internal structure of the FES-I was examined by factor analysis. ROC plots were used to define cut-point for the FES-I scales. Cronbachs α of the Turkish FES-I was 0.94 and the individual item ICC ranged from 0.97 to 0.99. The Turkish FES-I total scores were correlated with TUG positively, and MBI, and BBS negatively. The cut-off score to differentiate between persons with fear of falling and persons without fear of falling was 24 points. It was found that the Turkish version of the FES-I was a reliable and valid measure of fear of falling in Turkish older people.

INVESTIGATION OF THE RELATION BETWEEN ANAEROBIC BACTERIA GENUS CLOSTRIDIUM AND LATE-ONSET AUTISM ETIOLOGY IN CHILDREN

The aim of this study was to investigate the relation between the etiology of late-onset childhood autism and anaerobic bacteria. Thirty children diagnosed with autistic disorder and control group have been included in the study. 3-(3-hydroxy phenyl)-3-hydroxypropionic acid (HPHPA) excretion rates which is a metabolic product of the genus Clostridium, were measured via mass spectrometry-gas chromatography (MS-GC) method from urine samples. When the assayed average HPHPA values compared with each group, a statistically significant difference was found (p < 0.05). Data obtained from this study support the existence of a significant correlation between autism etiology and anaerobic bacteria.

Comparison of the Diagnostic Values of the 3 Different Stool Antigen Tests for the Noninvasive Diagnosis of Helicobacter pylori Infection

The aim of the study was to compare 3 stool antigen tests for diagnosis of Helicobacter pylori infection in adult patients with dyspeptic complaints before eradication therapy. We compared 2 enzyme immunoassays (EIAs: Premier Platinum Helicobacter pylori Stool Antigen [HpSA] Plus and Helicobacter pylori Antigen [Hp Ag]) and one immunochromatographic assay (H. pylori fecal antigen test-lateral-flow chromatography) in detecting H. pylori. All the investigated stool antigen tests were made of monoclonal antibodies. We evaluated 168 adult patients with H. pylori infection by using 2 criterion standard methods (histological and rapid urease tests) together. The sensitivity and specificity were 90% and 91%, respectively, for the Premier Platinum HpSA Plus, 77% and 91%, respectively, for the Hp Ag, and 81% and 92%, respectively, for the H. pylori fecal antigen test, respectively. The best agreement between the criterion standard tests and the stool antigen tests used in the study was with the Premier Platinum HpSA Plus. Immunochromatographic assay-based stool antigen test (H. pylori fecal antigen test) was found to be more sensitive than the EIA-based test (Hp Ag). One of the 2 important conclusions obtained from the study was that the Premier Platinum HpSA Plus was found to be the most accurate test for the diagnosis of H. pylori infection in adult dyspeptic patients before eradication therapy, and the other was that monoclonal and high-quality, reliable immunochromatographic assay tests are a good option especially for small hospital laboratories that do not have appropriate equipment for performing the EIA and working on few samples.

Reliability of Stool Antigen Tests: Investigation of the Diagnostic Value of a New Immunochromatographic Helicobacter pylori Approach in Dyspeptic Patients

BACKGROUND A diagnosis of H. pylori infection can be made by invasive or non-invasive methods. Several noninvasive diagnostic tests based on the detection of H. pylori stool antigen (HpSA) have been developed. The Genx H. pylori stool antigen card test is a new rapid, non-invasive test that is based on monoclonal immunochromatographic assay. The aim of this study was to determine its sensitivity, specificity, and diagnostic accuracy for diagnosing H. pylori infection in adult patients. MATERIALS AND METHODS A total of 162 patients were included in the study. A gastric biopsy was collected for histopathology and rapid urease testing. Stool specimens for HpSA testing were also collected. Patients were considered H. pylori positive if two invasive tests (histological and rapid urease tests) were positive. RESULTS Using the reference test, 50.6% of the samples were positive for H. pylori infection. The Genx H. pylori antigen test was positive in 19.7% of patients. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the Genx H. pylori antigen test were 51.6%, 96.0%, 88.8%, 76.1%, and 79.0%, respectively. CONCLUSIONS The Genx H. pylori stool antigen card test is a new non-invasive method that is fast and simple to perform but provides less reliable results.

Plasma‐soluble urokinase plasminogen activator receptor (suPAR) levels in Behçet's disease and correlation with disease activity

Soluble urokinase plasminogen activator receptor (suPAR), a new biomarker, is a soluble form of membrane‐bound receptors secreted from different immune cells. The aim of the present study is to determine plasma suPAR levels in Behçets disease and their correlation with disease activity.

Is the Mean Platelet Volume in Patients with Acute Cholecystitis an Inflammatory Marker

INTRODUCTION Acute cholecystitis is an inflammatory disease of the gallbladder. Ultrasonography (US) is the initial and the most valuable method in the diagnosis of acute cholecystitis. Also, laboratory findings are used to support the diagnosis. The aim of the present study was to evaluate the diagnostic value of mean platelet volume (MPV) and platelet (PLT) counts in patients with acute cholecystitis. MATERIALS AND METHODS From January to August 2014, the medical records of patients were reviewed for the diagnosis of acute cholecystitis. The study included 60 age-matched patients with acute cholecystitis and 60 healthy individuals as a control group. Patients with a chronic disease were excluded from the study. Over all, patients with acute cholecystitis and patients in the control group were evaluated for their MPV, PLT count, platelet distribution width (PDW), platelet crit (PCT) and erythrocyte sedimentation rate (ESR) in a complete blood count (CBC). RESULTS The MPV values were found to be significantly lower in the acute cholecystitis group when compared to the control group. The PDW and PCT were found to be significantly higher in the acute cholecystitis group when compered to the control group. When a correlation test was performed, MPV was negatively correlated with PLT and PCT counts. CONCLUSION US is the initial and the most important imaging method for diagnosing and evaluating the biliary system. Also, laboratory findings such as WBC, ESR and CRP support the diagnosis but may have some undesirable limitations. However, MPV is an acute phase reactant that does not require an additional cost because it is already worked in the CBC. Therefore, MPV can be used as a marker in diagnosing inflammatory diseases.

Use of biplot technique for the comparison of the missing value imputation methods

This study was performed to assess the effects of different imputation methods on the performance of a biplot technique. We selected the Fishers iris data as our reference dataset. Some elements of the Iris data were deleted in different rates under missing at random MAR assumption to generate incomplete datasets which had 3.5%, 7%, 15%, 20% missing value. Datasets with missing values were completed by four imputation methods [mean imputation, regression imputation, expectation maximisation EM algorithm, multiple imputation MI]. The new imputed datasets were analysed by biplot technique and their results were compared with original complete biplot of the data. The results of biplot analysis were similar in all the imputation methods when missing rate is low under MAR assumption. Even when the missing rate was greater than 10%, results of EM and MI methods were similar to real values and graphical representation of original data. For multivariate methods, we also propose filling in the missing value with the arithmetic mean of the imputed estimates which are obtained with multiple imputation. This paper also indicates that the use of biplot technique for the comparison of the missing value imputation methods provides a useful visual tool.

Radiological, clinical and audiological evaluation of jugular bulb–vestibular aqueduct dehiscence

Abstract Objective: The aim of this study is to determine the prevalence of jugular bulb–vestibular aqueduct dehiscence (JBVAD) in patients undergoing temporal bone multidetector computed tomography (MDCT) and assess the relationship between JBVAD and hearing loss with the findings of audiometry. Methods: About 1503 temporal bone MDCT scans were evaluated for the prevalence of JBVAD. Correlation of the imaging findings and audiometric data was performed. Patients were divided into two groups, those with and those without hearing loss, and were statistically compared. Results: Jugular bulb–vestibular aqueduct dehiscence was detected in 124 of the 1503 patients with a prevalence of 8.2%. MDCT images of 56 of the 124 patients were normal except for JBVAD (n = 38) and close proximity of the jugular bulb (JB) and vestibular aqueduct (VA) (n = 18). A total of 23 of 38 patients with JBVAD and 7 of 18 patients with close proximity of the JB and VA had hearing loss detected by audiometric evaluation. Conclusions: The most common hearing loss was detected as sensorineural hearing loss in patients with JBVAD. Also, median air and bone conduction and air bone gap values were found statistically higher in patients with hearing loss versus those without hearing loss.