Papers by Ali Rıza Şişman
Journal of Artificial Intelligence in Health Sciences
İç Kalite Kontrol (İKK), hasta numunelerini çalıştırmadan önce bir laboratuvar testinin güvenilir... more İç Kalite Kontrol (İKK), hasta numunelerini çalıştırmadan önce bir laboratuvar testinin güvenilirliğini değerlendirme ve kontrol etme sürecidir. Mevcut İKK süreci, kural tabanlı yaklaşımlar kullanarak Toplam Analitik Hatanın (TAE) yönetimine odaklanmaktadır. Toplam İzin Verilebilir Hata (TEa) ihlallerinin zamanlamasını tam olarak tahmin edemez. Çalışmada, Tahmine Dayalı Kalite Kontrol Algoritması (PQCA) için Gaussian Process for Machine Learning (GPML) yöntemini kullanarak İKK sürecini değerlendirmede tahmine dayalı bir hesaplama yaklaşımı önerildi. Python ve Scikit-learn kütüphanesinde yürütülen yazılım uygulaması, Windows tabanlı standart bir PC üzerinde çalıştırıldı. PQCA'ya dayalı bir dijital kontrol tablosu oluşturuldu. Gözlemlerin, PQCA tarafından üretilen karşılık gelen tahminlerinin %95 güven aralığı içinde kaldığı gösterildi. Ayrıca, klasik formül kullanılarak hesaplanan TAE'nin tüm TEa ihlallerini yakalayamadığı da ortaya konuldu. PQCA, ham kontrol verilerini doğru...
The International Arab Journal of Information Technology
Various studies use numerous probabilistic methods to establish a cause-effect relationship betwe... more Various studies use numerous probabilistic methods to establish a cause-effect relationship between a drug and a disease. However, only a limited number of machine learning studies on establishing cause-effect relationships can be found on the internet. In this study, we explore machine learning approaches for interpreting large quantities of multivariate patient-based laboratory data for establishing cause-effect relationships for critically ill patients. We adopt principal component analysis as a primary method to capture daily patient changes after a medical intervention so that the causal relationship between the medical treatments and the outcomes can be established. Model validity and stability are evaluated using bootstrap testing. The model exhibits an acceptable significance level with a two-tailed test. Moreover, results show that the approach provides promising results in interpreting large quantities of patient data and establishing cause-effect relationships for making ...
Journal of Anesthesia, Analgesia and Critical Care
Background Levosimendan has been reported to have a positive effect on ischemia–reperfusion injur... more Background Levosimendan has been reported to have a positive effect on ischemia–reperfusion injury. Herein, we aimed to evaluate the effects of levosimendan applied after reperfusion in an experimental intestinal injury-reperfusion (IR) model. Methods Twenty-one Wistar-albino male rats were separated into three groups: Sham group (n = 7): solely superior mesenteric artery (SMA) was dissected after laparotomy; intestinal ischemia–reperfusion group (IIR, n = 7): SMA was clamped for 60 min and unclamped for 120 min to cause ischemia–reperfusion; IIR + levosimendan group (IIR + L, n = 7): levosimendan was administered in ischemia–reperfusion model. The mean arterial pressures (MAP) were measured in all groups. MAP measurements were performed at the end of stabilization, at the 15th, 30th, and 60th minute of ischemia; at the 15th, 30th, 60th, and 120th minute of reperfusion; and at the end of levosimendan bolus application and when levosimendan infusion concluded. Reperfusion injury was ...
Balkan Journal of Electrical and Computer Engineering
Medical doctors of today are challenged with increasingly large volumes of high-dimensional, hete... more Medical doctors of today are challenged with increasingly large volumes of high-dimensional, heterogeneous and unstructured data from various sources that pose significant challenges for manual analysis. However, this unstructured data is mainly vital for decision making but there exists shortage of intelligent tools to extract the hidden knowledge. In view of these facts, application of machine learning methods in healthcare is a growing phenomenon. This paper explores machine learning approaches for interpreting large quantities of continuously acquired, multivariate patient based laboratory data, in intensive care unit (ICU) settings. The research hypothesizes that principal component analysis (PCA) can be able to capture the changes in the outcomes of applying medical interventions. We adopted PCA as a main method, to observe and capture the daily changes for intensive care unit patients. The approach will be able to inform the physicians, which laboratory tests are exhibiting v...
WOS: 000242863800001Blood levels of cadmium and lead as well as iron, copper, zinc, magnesium, ca... more WOS: 000242863800001Blood levels of cadmium and lead as well as iron, copper, zinc, magnesium, calcium, and phosphorus were determined in 87 workers of the tobacco industry and 35 healthy and unexposed control persons. The concentrations of cadmium and lead were measured by Graphite Furnace Atomic Absorption Spectrometry (GFAAS), whereas copper, zinc and magnesium were analyzed by Flame Atomic Absorption Spectrometry (FAAS). Iron, calcium and phosphorus were determined using colorimetric methods. Blood cadmium levels were significantly higher in workers than in controls, median concentrations being, 1.10 mu g/L and 0.50 mu g/L, respectively, (p=0.011). When the groups were further evaluated according to smoking habits, a significant difference was observed between the nonsmokers of the workers and the control group (p=0.05). Blood lead levels showed no significant difference between workers and controls. Serum calcium and zinc concentrations were significantly higher in the workers (p=0.002 and p=0.015, respectively), while no significant differences were observed with respect to concentrations of the other non-toxic elements
European review for medical and pharmacological sciences, 2016
OBJECTIVE Ischemia/reperfusion (I/R) injury is a major cause of acute organ dysfunction and I/R r... more OBJECTIVE Ischemia/reperfusion (I/R) injury is a major cause of acute organ dysfunction and I/R related acute renal failure is a common clinical problem. Diabetes mellitus is defined as a risk factor for the development of acute renal injury as diabetic nephropathy compromises the renal tolerance to ischemia. The aim of this study was to investigate the protective effect of magnesium sulfate in a diabetic rat renal I/R injury model. MATERIALS AND METHODS Diabetes mellitus was induced using streptozotocin. Thirty-five rats were divided into five groups: Group I: Nondiabetic sham group; Group II: Diabetic sham group; Group III: Diabetic I/R group; Group IV: Diabetic I/R + prophylactic (preischemic) MgSO4; and Group V: Diabetic I/R + therapeutic (following reperfusion) MgSO4 group. MgSO4 was administered 200 mg/kg intraperitoneally. Renal I/R (45 min ischemia + 4 h reperfusion) was induced in both kidneys. Histomorphological, immunohistochemical (caspase-3 and iNOS) and biochemical (BU...
American Journal of Clinical Pathology, 2016
Objectives: In the field of laboratory medicine, minimizing errors and establishing standardizati... more Objectives: In the field of laboratory medicine, minimizing errors and establishing standardization is only possible by predefined processes. The aim of this study was to build an experimental decision algorithm model open to improvement that would efficiently and rapidly evaluate the results of biochemical tests with critical values by evaluating multiple factors concurrently. Methods: The experimental model was built by Weka software (Weka, Waikato, New Zealand) based on the artificial neural network method. Data were received from Dokuz Eylül University Central Laboratory. "Training sets" were developed for our experimental model to teach the evaluation criteria. After training the system, "test sets" developed for different conditions were used to statistically assess the validity of the model. Results: After developing the decision algorithm with three iterations of training, no result was verified that was refused by the laboratory specialist. The sensitivity of the model was 91% and specificity was 100%. The estimated j score was 0.950. Conclusions: This is the first study based on an artificial neural network to build an experimental assessment and decision algorithm model. By integrating our trained algorithm model into a laboratory information system, it may be possible to reduce employees' workload without compromising patient safety.
Journal of Clinical Laboratory Analysis, 2017
BackgroundThe aim of this study is to evaluate and compare the analytical performance characteris... more BackgroundThe aim of this study is to evaluate and compare the analytical performance characteristics of the two creatinine methods based on the Jaffe and enzymatic methods.MethodsTwo original creatinine methods, Jaffe and enzymatic, were evaluated on Architect c16000 automated analyzer via limit of detection (LOD) and limit of quantitation (LOQ), linearity, intra‐assay and inter‐assay precision, and comparability in serum and urine samples. The method comparison and bias estimation using patient samples according to CLSI guideline were performed on 230 serum and 141 urine samples by analyzing on the same auto‐analyzer.ResultsThe LODs were determined as 0.1 mg/dL for both serum methods and as 0.25 and 0.07 mg/dL for the Jaffe and the enzymatic urine method respectively. The LOQs were similar with 0.05 mg/dL value for both serum methods, and enzymatic urine method had a lower LOQ than Jaffe urine method, values at 0.5 and 2 mg/dL respectively. Both methods were linear up to 65 mg/dL ...
The Kaohsiung journal of medical sciences, 2016
Cerebral ischemia may cause permanent brain damage and behavioral dysfunction. The efficacy and m... more Cerebral ischemia may cause permanent brain damage and behavioral dysfunction. The efficacy and mechanisms of pharmacological treatments administered immediately after cerebral damage are not fully known. Sugammadex is a licensed medication. As other cyclodextrins have not passed the necessary phase tests, trade preparations are not available, whereas sugammadex is frequently used in clinical anesthetic practice. Previous studies have not clearly described the effects of the cyclodextrin family on cerebral ischemia/reperfusion (I/R) damage. The aim of this study was to determine whether sugammadex had a neuroprotective effect against transient global cerebral ischemia. Animals were assigned to control, sham-operated, S 16 and S 100 groups. Transient global cerebral ischemia was induced by 10-minute occlusion of the bilateral common carotid artery, followed by 24-hour reperfusion. At the end of the experiment, neurological behavior scoring was performed on the rats, followed by evalu...
International Journal of Gynecology & Obstetrics, 2016
To investigate the relationship between thyroid function status and bone mineral density (BMD) am... more To investigate the relationship between thyroid function status and bone mineral density (BMD) among women with postmenopausal osteoporosis. A retrospective study was performed among 1217 women aged 45-80years who attended the Department of Obstetrics and Gynecology at Dokuz Eylul University, Izmir, Turkey, between August 1, 2009, and June 1, 2013. Eligible participants were grouped according to the presence or absence of osteoporosis as defined by BMD measurements at the lumbar vertebrae (L1-L4), femoral neck, or trochanter of the femur. Serum levels of free tri-iodothyronine, free tetraiodothyronine, and thyroid-stimulating hormone (TSH) were assessed. The 303 women with osteoporosis had a lower mean TSH level (1.8mIU/L) than did the 914 women without osteoporosis (1.9mIU/L; P=0.01). A positive correlation between TSH level and measures of BMD was observed (P=0.01). The TSH level was associated with a protective effect in a regression model for development of osteoporosis; the odds ratio was 0.68 (95% confidence interval 0.53-0.86). Osteoporosis appeared to be independently associated with serum TSH level. Maintaining TSH levels within the upper limit of the reference range during treatment of hypothyroidism could be important to prevent osteoporosis among postmenopausal women.
Journal of Korean Medical Science, 2015
fever (FMF) is an auto-inflammatory disease characterised by periodic inflammatory attacks. We in... more fever (FMF) is an auto-inflammatory disease characterised by periodic inflammatory attacks. We investigated changes in monocyte-granulocyte derived S10012A and chitotriosidase in both the attack and silent period of FMF for better estimation of inflammation. Endogenous resolvin was determined for utility to restrict inflammation. This study included 29 FMF patients (15 M/14 F) and 30 healthy controls (15 M/15 F). Serum levels of highly sensitive C-reactive protein, serum amiloid A (SAA), S100A12, chitotriosidase, and resolvin D1 were measured. Age, sex, body mass indexes, and lipids were similar between patients and controls. Biomarkers including hs-CRP, SAA, S100A12, chitotriosidase, and resolvin D1 were higher in the attack period of FMF patients compared to controls (P < 0.001). When FMF patients in the silent period were compared with their attack period, hs-CRP, SAA, and chitotriosidase were found elevated in the attack period (P < 0.001, P < 0.001, and P = 0.02 respectively). Serum levels of SAA, S100A12, chitotriosidase, and resolvin D1 in the silent period of FMF patients were still found elevated compared to healthy controls, indicating subclinical inflammation (P < 0.001, P < 0.001, P = 0.009, and P < 0.001 respectively). In subgroup analysis, patients with M694V homozygote and heterozygote mutations had higher S10012A and hs-CRP compared to other mutation carriers. Our findings indicate that chitotriosidase and S10012A are useful in diagnosis and detection of subclinical inflammation and/or assessment of disease activity in FMF patients. They could be more informative for inflammation in various disease states compared to hsCRP and SAA. Resolvin D1 is elevated in both the attack and silent periods of FMF. It may be helpful to restrict inflammation.
The Turkish journal of pediatrics
The differences in growth patterns in breast-fed (BF) and formula-fed (FF) infants remain poorly ... more The differences in growth patterns in breast-fed (BF) and formula-fed (FF) infants remain poorly understood. The aim of this study was to examine the relation of serum ghrelin and leptin concentrations to the different growth patterns between the formula-fed and breast-fed babies. Feeding behaviors and anthropometric data were noted at the 3rd and 6th months of age. Serum ghrelin and leptin levels in both groups and breast-milk ghrelin and leptin levels in the mothers of the BF group were determined at the 3rd month of age. Body weight, length, TSF (triceps skin fold thickness), postnatal weight gain, and serum ghrelin levels were higher in BF babies than in the FF group. In BF babies, serum ghrelin was correlated to TSF, and serum leptin was correlated to weight, TSF and weight gain at three months of age. As the serum leptin increased, energy intake from supplemental foods decreased in the BF group at the 6th month. Higher serum ghrelin in BF babies might have played a role in the...
Journal of Atherosclerosis and Thrombosis, 2011
Paraoxanase 1 (PON 1) has been shown to protect against atherosclerosis by modifying lipoproteins... more Paraoxanase 1 (PON 1) has been shown to protect against atherosclerosis by modifying lipoproteins. Its activity decreases in dialysis patients but is restored after transplantation. Whether it affects arterial stiffness is unclear. In this study we aimed to investigate the effects of PON 1 on arterial stiffness in renal transplant patients. Methods: Seventy renal transplant recipients were enrolled. Arterial stiffness was measured using a Syphmocor device. PON-1 activity was assessed from the rate of enzymatic hydrolysis of paraoxon to p-nitrophenol. Results: Mean age was 39.0 9.6 years and 5.7% of the patients were diabetic. Post-transplant follow-up time was 46.7 37.9 months. Eighty-five percent received anti-hypertensive and 12.9% antihyperlipidemic medication. Mean PON1 activity was 75.9 52.4 U/L. PON1 activity was negatively correlated with systolic and diastolic blood pressure, mean arterial pressure, LDL-cholesterol and carotid-femoral pulse wave velocity (cf-PWV). Mean c-f PWV was 8.10 1.39 m/s. Cf-PWV was positively correlated with age, systolic and diastolic blood pressure, mean arterial pressure, proteinuria and negatively correlated with PON1, PON1/HDL ratio and creatinine clearance. In linear regression analysis, PON1 was a predictor of cf-PWV in a model that included age, gender, diabetes, mean arterial pressure, urine protein level, creatinine clearance and PON 1. Conclusions: Reduced PON1 activity is significantly associated with increased arterial stiffness. The results of this study show the possible role of PON1 for arterial stiffening in renal transplant recipients.
Balkan Medical Journal, 2012
Objective: Seroma is the most common complication after breast surgery. Several methods have been... more Objective: Seroma is the most common complication after breast surgery. Several methods have been proposed to prevent seroma, but none of these provided a significant effect. A prolonged wound healing process is the most important cause of seroma. Microporous polysaccharide hemospheres (MPH) are used to achieve hemostasis. They may also accelerate wound healing. In this study, the effects of MPH on seroma formation were investigated. Material and Methods: Female Wistar rats weighing between 200 g and 250 g were used. There were eight rats in each of the control and study groups. Right breast mastectomy and axillary dissection were performed in all rats. While no application was performed after the operation in the control group, MPH was locally applied to the surgical site in the study group. Ten days after the operation, seroma fluid was aspirated and the total volume was recorded. The aspirates were analyzed and tissue samples were obtained from the surgical site. Results: Seroma was significantly lower in the study group (p=0.001). The mean albumin and lactate dehydrogenase levels were significantly lower in the study group (p=0.003). Pathological examination revealed that increase in fibrous tissue was significantly greater in the control group (p=0.032). Conclusion: MPH may reduce seroma after mastectomy.
Turkish Neurosurgery, 2012
AIm: Traumatic brain injury (TBI) may cause neuropsychiatric disorders such as anxiety disorder w... more AIm: Traumatic brain injury (TBI) may cause neuropsychiatric disorders such as anxiety disorder which has negative effects on cognitive functions and behavior. The aim of this study is to investigate the effects of TBI on anxiety and vascular endothelial growth factor (VEGF) immunoreactivity on the prefrontal cortex of immature rats, which is one of the anxiety-related regions of the brain in 7-day-old immature rats subjected to contusion injury. mATeRIAL and meTHods: Rats were divided into three groups: Control (n=7), Sham (n=7) and TBI (n=7). Anxiety levels were assessed with open field activity and elevated plus maze in postnatal 27 days. Prefrontal cortex damage related to TBI was examined by cresyl violet staining and VEGF immunostaining. Prefrontal cortex neuronal density was calculated. Serum corticosterone levels were determined. ResuLTs: The anxiety level in the TBI group was significantly greater than the control and sham groups. The prefrontal cortex VEGF immunostaining score and neuron density were decreased in the TBI group compared to control and sham group. Serum corticosterone levels were significantly increased in the TBI group. CoNCLusIoN: These results indicate that TBI decreases VEGF immunoreactivity in prefrontal cortex neurons and increases the anxiety levels of immature rats.
Clinical Chemistry and Laboratory Medicine (CCLM), 2014
A nationwide multicenter study was organized to establish reference intervals (RIs) in the Turkis... more A nationwide multicenter study was organized to establish reference intervals (RIs) in the Turkish population for 25 commonly tested biochemical analytes and to explore sources of variation in reference values, including regionality.Blood samples were collected nationwide in 28 laboratories from the seven regions (≥400 samples/region, 3066 in all). The sera were collectively analyzed in Uludag University in Bursa using Abbott reagents and analyzer. Reference materials were used for standardization of test results. After secondary exclusion using the latent abnormal values exclusion method, RIs were derived by a parametric method employing the modified Box-Cox formula and compared with the RIs by the non-parametric method. Three-level nested ANOVA was used to evaluate variations among sexes, ages and regions. Associations between test results and age, body mass index (BMI) and region were determined by multiple regression analysis (MRA).By ANOVA, differences of reference values among...
Neuroscience Letters, 2013
It is already known that regular aerobic exercise during adolescent period improves learning and ... more It is already known that regular aerobic exercise during adolescent period improves learning and memory in rats. In this study, we investigated the effects of regular aerobic exercise on learning, memory functioning and IGF-1 levels. IGF-1 is known to have positive effects on cognitive functions in adolescent rats. Exercise group was separated into two different groups. First half was run on a treadmill for 30 min per session at a speed of 8m/min and 0° slope, five times a week for 6 weeks. The second half was given free access to a running wheel (diameter 11.5 cm) which was connected to a digital counter and run on a treadmill for 6 weeks. Learning and memory functioning were found to be positively correlated with the exercise activity. Findings suggest increased neuron density in CA1 hippocampal region and dentate gyrus. Increased IGF-1 level was detected in hippocampus and blood serum, while IGF-1 level in liver tissue did not change with exercise activity. In conclusion, our findings indicate that learning and memory functioning were positively affected by voluntary and involuntary physical exercise which correlated increased hippocampal activity and elevated IGF-1 levels in adolescent rats.
Neuroscience Letters, 2012
It is well known that diabetes mellitus may cause neuropsychiatric disorders such as anxiety diso... more It is well known that diabetes mellitus may cause neuropsychiatric disorders such as anxiety disorders. Diabetes may also cause reduced IGF-1 (insulin like growth factor-1) levels in brain and blood. The purpose of the present study was to investigate the relationship between diabetes induced anxiety and IGF-1 levels in diabetic rats. The anxiety levels of rats were assessed 2 weeks after intraperitoneal injection of streptozotocin. Diabetic rats had higher levels of anxiety, as they spent more time in closed branches in elevated-plus-maze-test and less time in the center cells of openfield-arena. Prefrontal cortex (PFC) IGF-1 levels and neuron numbers were decreased and apoptosis was increased in diabetic rats. Blood IGF-1 levels decreased in a time dependent fashion following streptozotocin injection while blood corticosterone levels increased. They had higher malondialdehyde levels and lower superoxide dismutase enzyme activity. Oxidative stress may negatively affect blood and PFC tissue IGF-1 levels. Reduction in IGF-1 may cause PFC damage, which may eventually trigger anxiety in diabetic rats. Therapeutic strategies that increase blood and brain tissue IGF-1 levels may be promising to prevent psychiatric sequelae of diabetes mellitus.
European Journal of Pediatric Surgery, 2002
In gastroschisis, contact with amniotic fluid (AF) causes intestinal damage. Intraamniotic meconi... more In gastroschisis, contact with amniotic fluid (AF) causes intestinal damage. Intraamniotic meconium has been shown to be responsible for the intestinal damage, and intestinal damage has been shown to correlate with intraamniotic meconium concentrations. Intraamniotic meconium below a threshold level does not cause intestinal damage. Intraamniotic meconium concentrations can be lowered by AF exchange. Can induction of foetal diuresis by an intraamniotic injection of furosemide be used as an alternative method for the same purpose? Pregnant rabbits on the 23rd - 25th gestational days (normal gestation time: 31 - 33 days) were divided into two groups, the control group and the furosemide group. Initial AF samples were taken, then either 5 mg/kg furosemide or a placebo was injected into the amniotic cavity. Final AF samples were obtained 6 hours later. AF urea nitrogen, creatinine, amylase, alkaline phosphatase and bilirubin levels were determined. There was no significant difference between the initial and final levels of AF urea nitrogen, creatinine, bilirubin, amylase, and alkaline phosphatase in the control group, while the final AF urea nitrogen and creatinine levels of the furosemide group were not significantly different from the initial levels (p &gt; 0.05). Final AF bilirubin, amylase and alkaline phosphatase levels of the furosemide group were significantly decreased compared with initial levels (p &lt; 0.01). Induction of foetal diuresis with intraamniotic furosemide is effective for the removal of intestinal waste products from amniotic fluid.
Disease Markers, 2014
Background. It is well known that diabetes mellitus may cause testicular damage. Vascular endothe... more Background. It is well known that diabetes mellitus may cause testicular damage. Vascular endothelial growth factor (VEGF) and nerve growth factor beta (NGF-β) are important neurotrophic factors for male reproductive system.Objective. We aimed to investigate the correlation between testicular damage and testicular VEGF and NGF-βlevels in diabetic rats.Methods. Diabetes was induced by streptozotocin (STZ, 45 mg/kg/i.p.) in adult rats. Five weeks later testicular tissue was removed; testicular VEGF and NGF-βlevels were measured by ELISA. Testicular damage was detected by using hematoxylin and eosin staining and periodic acid-Schiff staining, and apoptosis was identified by terminal-deoxynucleotidyl-transferase-mediated dUTP nick end labeling (TUNEL). Seminiferous tubular sperm formation was evaluated using Johnsen’s score.Results. In diabetic rats, seminiferous tubule diameter was found to be decreased; basement membrane was found to be thickened in seminiferous tubules and degenerate...
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Papers by Ali Rıza Şişman