Biomedical subjects

Muhittin A Serdar

Publications and source records attributed to Muhittin A Serdar.

10 recordsLinked to original sources

PubMed2005

Effect of macro-creatine kinase and increased creatine kinase BB on the rapid diagnosis of patients with suspected acute myocardial infarction in the emergency department.

Although there are more sensitive and earlier diagnostic markers for the diagnosis of acute myocardial infarction (AMI), measurement of creatine kinase (CK) MB isoenzyme (CKMB) using the immunoinhibition method is still widely used in stat laboratories. In this study, 3,290 patients with the prediagnosis of AMI underwent physical examinations, electrocardiography, and repetitive measurements of CK, CKMB activity, and CKMB mass, and 304 of them were diagnosed as having AMI. Electrophoresis of CK and CKMB mass was performed for the samples from 415 patients whose CKMB activity values were found to be increased and were not correlated with total CK levels. According to CKMB activity, CK electrophoresis, and CKMB index (100 x CKMB activity/CK) values, macro-CK (MCK) and/or increased CKBB levels were detected in 27 cases (MCK-I in 10 cases, MCK-II in 9, increased CKBB in 5, and both MCK-II and increased CKBB in 3). CKMB activity was found to be increased for all except one patient (96.3%), and the CKMB index was >25% in 25 (92.5%) of 27 cases. CKMB mass values were within the normal range in 25 of the cases with MCK. Two patients with MCK-I were diagnosed as having AMI because of increased CKMB mass and positive electrocardiography findings. The incidence of MCK and/or high CKBB levels (0.82%) in the whole group was similar to that reported for a normal population. MCK existence and increased CKBB levels may cause misleading diagnoses if CKMB mass measurements and/or CKMB index values are not used together for patients with suspected AMI.

Adult↗

PubMed2004

Exogenously administered and endogenously produced melatonin reduce hyperbaric oxygen-induced oxidative stress in rat lung.

Hyperbaric oxygen (HBO) is a widely used treatment modality in many diseases. A known side effect of HBO is the production of reactive oxygen species. Many antioxidants such as vitamins C and E, riboflavin and selenium have been used successfully to scavenge the reactive oxygen species caused by HBO administration. In this study, we aimed to see if melatonin, a newly discovered antioxidant, has a protective effect against the overproduction of reactive oxygen species produced by HBO in rat lung tissue. Sixty male Sprague-Dawley rats were divided into 5 groups as follows: control, daytime HBO (3 ATA, 120 min), daytime HBO plus melatonin (10 mg/kg), nighttime HBO and nighttime HBO (under light exposure). The MDA, SOD and CAT levels of daytime and nighttime HBO (under light exposure) increased significantly. This significance was not found in the daytime HBO plus melatonin and nighttime HBO groups when compared with the control. In this study, HBO caused oxidant stress, and melatonin decreased the levels of MDA, SOD and CAT. Moreover, endogenous melatonin was found to be a more effective antioxidant than exogenous 10 mg/kg melatonin.

Animals↗

PubMed2004

Plasma ionized magnesium levels in neonatal respiratory distress syndrome.

Measurement of ionized magnesium (IMg) provides an accurate assessment of the free form of Mg, which is the physiologically active form and is most reflective of the biologically active and not easily measurable intracellular Mg fraction. Plasma levels of IMg were measured by ion-selective electrode method in premature newborns with respiratory distress syndrome (RDS), and relationships and correlations between IMg levels and various demographic, prognostic and laboratory characteristics were investigated by comparing the premature newborns with (study group; n = 19) and without RDS (control group; n = 20) in the present study. The values of the postnatal arterial pH and base excess and plasma IMg levels were significantly different between the study and control groups, and the number of newborns with any morbidity was significantly higher in the study group. Within the study group there were significant negative correlations between the plasma IMg levels and the values of the umbilical cord arterial pH (r = -0.621, p = 0.005) and base excess (r = -0.746, p = 0.001), and the value of the postnatal arterial base excess (r = -0.585, p = 0.008). The newborns who died later had higher plasma IMg levels than those who survived (0.89 +/- 0.45 vs. 0.63 +/- 0.24 mmol/l, p = 0.026). These findings suggest that increase of plasma IMg may be due to extracellular movement of Mg, which is a principally intracellular ion, as a result of acidosis, hypoxia and probable cellular injury during the early course of RDS. The exact pathophysiological mechanism responsible for IMg increase, and whether determination of plasma IMg level, including umbilical cord blood IMg measurement, can be used as an early or predictive indicator of RDS in the diagnosis remain to be determined in further large-scale studies.

Arteries↗

PubMed2004

Incidence, course, and prediction of hyperbilirubinemia in near-term and term newborns.

OBJECTIVE: In this study, we investigated prospectively the incidence of significant hyperbilirubinemia and demographic and laboratory characteristics and pattern of serum bilirubin levels of near-term newborns (35-37 weeks' [245-265 days'] gestation) by comparing them with those of term newborns (38-42 weeks' [266-294 days'] gestation) longitudinally in the first 7 days of life; we also aimed to determine the value of an early (6th-hour) serum bilirubin measurement in predicting the development of significant hyperbilirubinemia later during the first week of life in near-term newborns. METHODS: Serum total bilirubin measurements were initially made at the 6th hour of life and repeated daily for the next 4 days, and a last measurement was performed on the 7th day (150th hour) in 219 term newborns (term group) and 146 near-term newborns (near-term group). Newborns with serum total bilirubin levels of > or =8 and > or =12 mg/dL on day 2, > or =12 and > or 15 mg/dL on day 3, and > or =14 and > or =17 mg/dL on days 4, 5, and 7 for birth weights 2000 to 2500 g and >2500 g, respectively, were defined to have significant hyperbilirubinemia, and phototherapy treatment was started. The predictive ability of the 6th-hour serum total bilirubin value in determining the development of significant hyperbilirubinemia in the near-term group was assessed on the basis of the placement of any of the first week's serum bilirubin measurements in the > or =95th percentile of the study population. A Gaussian distribution curve, the 5th, 30th, 60th, and 95th percentiles, and 4 percentile tracks were obtained from mean serum total bilirubin values. On the basis of the percentile tracks with various sensitivity, specificity, and negative and positive predictive values, a nomogram demonstrating the 4 percentile tracks as risk-zone demarcators with divided risk zones was produced. RESULTS: Twenty-three newborns (10.5%) in the term group and 37 newborns (25.3%) in the near-term group had significant hyperbilirubinemia and required phototherapy. When the daily mean serum bilirubin levels of the 2 groups were compared, the first 4 days' values did not significantly differ between the 2 groups, whereas the 5th and 7th days' values were significantly higher in the near-term group. There were significant differences between the 2 groups with respect to the incidence of significant hyperbilirubinemia, hematocrit, Apgar score, and mode of delivery. On the age-specific nomogram, the zone >95th percentile was labeled as high risk, and that <5th percentile was labeled as low risk. Serum total bilirubin values between the 5th and 30th, 30th and 60th, and 60th and 95th percentiles were designated as being in the low-intermediate, intermediate, and high-intermediate risk zones, respectively. The 5th and 95th percentiles on the nomogram had the highest sensitivity (100%) and specificity (98.2%), respectively, in predicting the subsequent development of significant hyperbilirubinemia. CONCLUSIONS: Near-term newborns should not be treated as term newborns in the approach to management of hyperbilirubinemia, because infants of 35 to 37 weeks' gestation had significantly lower birth weights, significantly higher serum total bilirubin levels on days 5 and 7, and were 2.4 times more likely to develop significant hyperbilirubinemia than those of 38 to 42 weeks' gestation in the present study. In near-term newborns of 35 to 37 weeks' (245 to 265 days') gestation, the decision to diagnose and treat significant hyperbilirubinemia should be made on the basis of risk status (percentile distribution of the serum bilirubin values on postnatal age) rather than using birth-weight-based thresholds. A nomogram constructed from daily serum bilirubin values of each population, as we present herein, can be used in assessing the age (hour)-specific jaundice risk (high, intermediate, or low) of each near-term newborn.

Birth Weight↗

PubMed2003

Evaluation of plasma ionized magnesium levels in neonatal hyperbilirubinemia.

Plasma levels of ionized magnesium (IMg) measured by ion-selective electrode were investigated in neonatal hyperbilirubinemia by comparing the newborns with (> or =205 microM) and without (<205 microM) significant hyperbilirubinemia (groups of severe and moderate hyperbilirubinemia, respectively). Serum bilirubin, plasma IMg, and ionized calcium (ICa) levels were determined in 165 healthy term newborns with nonhemolytic indirect hyperbilirubinemia during the first 10 d of life. Mean serum bilirubin, plasma IMg, and ICa levels were 200.1 +/- 126.5 microM, 0.54 +/- 0.12 mM, and 1.15 +/- 0.12 mM, respectively, in 165 newborns whose mean postnatal age was 156.1 +/- 46.5 h, and there was a significant positive correlation between the mean serum bilirubin and plasma IMg levels (r = 0.535, p < 0.001). Serum bilirubin levels (304.4 +/- 83.8 microM versus 94.1 +/- 54.7 microM) and plasma IMg levels (0.6 +/- 0.12 mM versus 0.49 +/- 0.1 mM) were significantly higher and plasma ICa levels (1.13 +/- 0.12 mM versus 1.18 +/- 0.12 mM) were significantly lower in the group of severe hyperbilirubinemia (n = 83) when compared with the group with moderate hyperbilirubinemia (n = 82). Seventeen of the 83 cases of severe hyperbilirubinemia had IMg levels above the normal range (> or =0.69 mM), whereas none of the 82 cases of moderate hyperbilirubinemia had elevated IMg levels. Fifteen of the 17 with high IMg levels had bilirubin levels >290 microM. Results of the present study suggest that increase in plasma IMg may be due to extracellular movement of Mg, a principally intracellular ion, resulting from generalized cellular injury including neurons and erythrocytes. Considering neuroprotective functions and beneficial effects of Mg ion in improving neurologic outcome, we also may speculate the possibility of a neuroprotective role or a compensatory mechanism in IMg increase against emerging toxicity risk of increasing serum bilirubin levels.

Bilirubin↗

PubMed2003

BHK cell attachment and growth on EDA-plasma-modified poly(L-lactide/epsilon-caprolactone) biodegradable films.

In this study, attachment and growth of Baby Hamster Kidney (BHK) cells on ethylene diamine (EDA)-plasma-treated poly(L-lactide/epsilon-caprolactone) biodegradable copolymer films were investigated. The co-polymer (Mw: 58000; Mn: 35000 and PI 1.60) was synthesised by ring-opening polymerization of the respective dimers with using stannous octoate as the catalyst. The final ratio of L-lactide to epsilon-caprolactone obtained by 1H-NMR was 87:13. The co-polymer films were treated with the EDA-plasma in a glow-discharge apparatus. The BHK-30 cell line was cultured on plain and EDA-plasma-treated films and their pre-wetted forms (with ethanol and/or cell culture medium before use). Cell attachment and growth were followed. Alkaline phosphatase (ALP) activity and glucose uptake in cell culture medium were also investigated. There was no attachment in the first 12 h. Glow-discharge treatment increased significantly the attachment and growth. Pre-wetting with ethanol and cell culture medium was also increase significantly both the attachment and growth.

Alkaline Phosphatase↗

PubMed2002

Oxidative phosphorylation enzyme complexes in caloric restriction.

Free radicals, generated especially by electron leakage from mitochondrial electron transport chain (ETC), are accepted as one of the possible causes of aging. Long-term caloric restriction (CR) is known to increase the species specific average and maximum life spans. Thus it provides a means for investigating mechanisms of aging. There is evidence suggesting a decrease in the free radical production with CR. In this study, Blue-Native PAGE (BN-PAGE) technique was used to investigate the effect of CR on the oxidative phosphorylation enzyme complexes. Of the total 30 female Swiss Albino balb/c mice, 15 were used as control and the other 15 as CR group. Alternate day feeding regimen was used in the CR group for 66 weeks beginning at the end of 3rd month. In the control group, 5 (33.3%) mice died, 3 (20%) of them of breast cancer, 2 (13.3%) of unknown causes and no death cases were observed in the CR group during the study. BN-PAGE was performed on the extracts from brain mitochondrial fractions. Complexes II and V were excluded from the study due to some analytical limitations. No difference was found in the levels of complexes I and III between the groups. In the CR group, complex IV level was found increased and the ratio of complex III-IV decreased compared with the control group. Since there is a slight increase (108%) in the level of complex IV in the CR group, our results could suggest possible partial compensation of electron leakage in the upstream complexes in ETC, and the decrease of free radical production with CR.

Adenosine Triphosphatases↗

PubMed2002

An early (sixth-hour) serum bilirubin measurement is useful in predicting the development of significant hyperbilirubinemia and severe ABO hemolytic disease in a selective high-risk population of newborns with ABO incompatibility.

OBJECTIVE: In the era of early discharge of newborns from the hospital, newborns with ABO incompatibility are at especially greater risk for developing a subsequent significant hyperbilirubinemia because some of these infants also may present with some degree of ABO isoimmune disease. In this study, we aimed to determine prospectively the critical serum total bilirubin level to predict significant hyperbilirubinemia and severe hemolytic disease in healthy term newborns with ABO incompatibility based on a serum bilirubin measurement made at a postnatal age at which all newborns are at the hospital before discharge and at which any therapeutic intervention, if necessary, could be started as early as possible. METHODS: A total of 136 healthy term newborns with ABO (O-A or O-B) blood group incompatibility were followed prospectively with daily serum total bilirubin measurements for the first 5 days of life. Newborns with serum total bilirubin levels of > or =5 mg/dL and an increase in serum total bilirubin concentration of >0.5 mg/dL/h in the first 24 hours, > or =12 mg/dL on day 2, > or =15 mg/dL on day 3, and > or =17 mg/dL on days 4 and 5 were defined to have significant hyperbilirubinemia and were started on phototherapy treatment. Additional treatment modalities, including intense phototherapy, intravenous immunoglobulin treatment, and exchange transfusion, were used when serum bilirubin concentrations exceeded 20 mg/dL or increased by >1 mg/dL/h despite a phototherapy treatment of at least 4 hours. The additional assessment of the predictive ability of the sixth-hour serum total bilirubin value in determining the development of significant hyperbilirubinemia was made on the basis of the placement of any of the first 5 days' serum bilirubin measurements in the > or =90th percentile of the study population. On the basis of the percentile tracks constructed from the 10th, 35th, 50th, 60th, and 90th percentiles of serum total bilirubin values, a nomogram demonstrating the 3 percentile tracks as risk zone demarcators with divided risk zones was produced. RESULTS: Twenty-nine newborns (21.3%) had significant hyperbilirubinemia. There were significant differences between the newborns who did and the newborns who did not develop significant hyperbilirubinemia with respect to the reticulocyte count (4.39 +/- 3.46% vs 2.95 +/- 1.63) and the presence of a direct antiglobulin test positivity (6 of 23 vs 0 of 107) and a sibling with neonatal jaundice (6 of 23 vs 5 of 102). A mean serum bilirubin level of > or =4 mg/dL at the sixth hour of life was determined to have the highest sensitivity (86.2%) and negative predictive value (94.5%) and a positive predictive value of 39.7% to predict the newborns who would develop significant hyperbilirubinemia. At the mean serum bilirubin level of 6 mg/dL, the sensitivity, specificity, and negative and positive predictive values were 100%, 91.5%, 100%, and 35.3%, respectively, in diagnosing 6 cases of severe ABO hemolytic disease. On the hour (age)-specific percentile-based nomogram, the zone above the 90th percentile was determined as high risk and that below the 35th percentile as low risk. CONCLUSIONS: The reticulocyte count, a positive direct antiglobulin test, and the presence of a sibling with neonatal jaundice were determined to be the good predictors for the development of significant hyperbilirubinemia and severe hemolytic disease of the newborn. A serum bilirubin measurement and the use of the critical bilirubin levels of 4 mg/dL and 6 mg/dL at the sixth hour of life will predict nearly all newborns who will have significant hyperbilirubinemia and those who will develop severe hemolytic disease of the newborn, respectively. An hour (age)-specific percentile-based nomogram can be used to predict which newborn is at high risk (> or =90th percentile), intermediate risk (35th-90th percentiles), and low risk (<35th percentile) for developing significant hyperbilirubinemia. The 35th and 90th percentile tracks, approximating the serum bilirubin levels of 3.3 mg/dL and 6.5 mg/dL at the sixth hour of life, respectively, can be used as safe risk demarcators in deciding about the time of discharge of ABO-incompatible newborns from the hospital.

ABO Blood-Group System↗

PubMed2002

Evaluation of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 levels in gingival fibroblasts of cyclosporin A-treated patients.

BACKGROUND: Cyclosporin A (CsA) is a potent immunosuppressant used to prevent organ transplant rejection and to treat various autoimmune diseases. CsA-induced gingival overgrowth (CsA GO) is the most widely seen side effect of this drug; its pathogenesis is not completely understood. The aim of this study was to identify and compare matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels in gingival fibroblast cultures of tissues derived from renal transplant patients receiving CsA and exhibiting gingival overgrowth and from periodontally healthy control subjects. METHODS: Gingival overgrowth samples were obtained from patients undergoing therapy with CsA, and control tissues were obtained from systemically healthy donors. Gingival fibroblasts were grown using explant cultures. Three different study groups were identified: 1) CsA GO fibroblast culture; 2) CsA-treated healthy gingival fibroblast culture (H+CsA); and 3) healthy gingival fibroblast culture (H). The levels of MMP-1 and TIMP-1 in these groups of gingival fibroblasts were analyzed by enzyme-linked immunoabsorbent assay (ELISA). RESULTS: The levels of TIMP-1 were significantly lower in CsA GO than H (P < 0.05). There was no statistically significant difference in the levels of MMP-1 between H and CsA GO (P = 0.505). The ratio of MMP-1 to TIMP-1 was significantly higher in CsA GO than H (P < 0.05). CONCLUSIONS: The results of this study indicate that CsA therapy does not have a significant effect on MMP-1 levels. However, low TIMP-1 levels can be an important factor in the pathogenesis of CsA GO, since the balance between MMP-1 and TIMP-1 levels was changed by CsA.

Adult↗

PubMed2002

Diagnostic approach to prostate cancer using total prostate specific antigen-based parameters together.

This prospective study investigated the value of serum total prostate specific antigen (tPSA)-based parameters in the diagnosis of prostate cancer (PCa). Serum tPSA, free to tPSA ratio (f/tPSA), PSA density (PSAD), and PSA transition zone (PSAT) were evaluated in 110 patients with histologically confirmed benign prostate hyperplasia (BPH) and 98 patients with PCa. Once the serum tPSA was elevated (greater than 4 ng/ml) or digital rectal examination (DRE) was suspicious, transrectal ultrasound-guided biopsies were recommended. The tPSA, f/tPSA, PSAD, and PSAT levels were significantly different between the BPH and PCa groups. In patients with a tPSA level of 4.1-9.9 ng/ml or an abnormal DRE finding, only PSAT was found to have discriminating power. The cut-off values were 0.15 for f/tPSA, 0.30 for PSAT, and 0.15 for PSAD. The diagnostic sensitivity of a positive result for one of these parameters in the whole group was 84%, but 75% in patients with a tPSA of 4.1-9.9 ng/ml or an abnormal DRE finding. The diagnostic specificity of positive results for 3 parameters was 92% in the whole group and 93% in patients with a tPSA of 4.1-9.9 ng/ml or an abnormal DRE finding. All parameters were influenced by the histological grades. Histological grades showed a negative correlation (r = -0.56) with f/t PSA and a positive correlation (r = 0.44) with PSAT. No diagnostic marker investigated heretofore was able to rule out or detect early PCa in patients with a PSA level of 4.1-9.9 ng/ml. Using the PSA-based parameters together can be helpful in management of these patients. If all of the PSA-based parameters are negative, biopsy might be postponed; patients who have three positive PSA-based parameters should be biopsied. In case of one or two of the parameters, the patient's age and race should be considered in clinical decision-making.

Aged↗