Association between age-related macular degeneration and 25(OH) vitamin D levels in the Turkish population / Associação entre degeneração macular relacionada à idade e níveis de vitamina D 25(OH) na população turca

ABSTRACT Purpose: Age-related macular degeneration is the most common cause of blindness in developed countries, and several factors have been attributed for its etiology. This study was conducted to explore the relationship between serum vitamin D levels and age-related macular degeneration. Methods: We retrospectively analyzed the data of 114 patients with age-related macular degeneration. A total of 102 patients who did not have any other diseases than refractive error were allocated to the control group. The best-corrected visual acuity, fundus findings, and spectral domain optical coherence tomography findings were analyzed. Patients were allocated to groups based on the Age-related Eye Disease Study classification. Serum 25(OH) vitamin D levels were measured. The central foveal thickness and the subfoveal choroidal thickness were measured by optical coherence tomography. Results: The 25(OH) vitamin D levels in age- and gender-matched patients with age-related macular degeneration and in healthy subjects were 14.6 ± 9.8 and 29.14 ± 15.1 ng/ml, respectively. The age-related macular degeneration group had significantly lower vitamin D levels than the control group (p>0.001). The subfoveal choroidal thickness was lower in patients with age-related macular degeneration (p>0.001). The 25(OH) vitamin D level showed a weak positive correlation with choroidal thickness (r=0.357, p=0.01). When the level of 25(OH) vitamin D was evaluated according to the stages of age-related macular degeneration, it was found to be lower in the advanced-stage disease (p=0.01). The risk for the development of choroid neovascular membrane and subretinal fibrosis was found to increase with decreased vitamin D levels. Conclusions: Significantly decreased levels of 25(OH) vitamin D in advanced-stage age-related macular degeneration suggest a significant correlation existing between vitamin D deficiency and age-related macular degeneration development. Further studies are required to examine whether vitamin D supplementation has an effect on the development and progression of age-related macular degeneration.

RESUMO Objetivo: A degeneração macular relacionada à idade é a causa mais comum de cegueira em países desenvolvidos e muitos fatores etiológicos têm-lhe sido atribuídos. O objetivo do presente estudo foi investigar a relação entre os níveis séricos de vitamina D e a degeneração macular relacionada à idade. Métodos: Os dados de 114 pacientes com degeneração macular relacionada à idade foram analisados retrospectivamente. Foram alocados no Grupo Controle 102 pacientes sem registro de outras doenças além do erro refrativo. A acuidade visual melhor corrigida, os achados do exame de fundo de olho e os da tomografia de coerência óptica de domínio espectral foram analisados. Os pacientes foram alocados em grupos de acordo com a classificação do Age-Related Eye Disease Study (Estudo da Doença Ocular Relacionada à Idade). Os níveis séricos de vitamina D 25(OH) foram medidos. A espessura foveal central e a espessura da coroide subfoveal foram medidas com tomografia de coerência óptica. Resultados: Os níveis de vitamina D 25(OH) em pacientes com degeneração macular relacionada à idade e em indivíduos saudáveis pareados por idade e sexo foram 14,6 ± 9,8 ng/mL e 29,14 ± 15,1 ng/mL, respectivamente. Os níveis de vitamina D foram significativamente menores no Grupo da Degeneração Macular relacionada à idade em comparação com o Grupo Controle (p>0,001). O valor da espessura da coroide subfoveal foi menor em pacientes com degeneração macular relacionada à idade (p>0,001). Foi encontrada uma fraca correlação positiva entre o nível de vitamina D 25(OH) e a espessura da coroide (r=0,357, p=0,01). O nível de vitamina D 25(OH), quando avaliado de acordo com os estágios da degeneração macular relacionada à idade, revelou ser menor na doença em estágio avançado (p=0,01). Constatou-se um risco aumentado de desenvolvimento de membrana neovascular da coroide e de fibrose sub-retiniana com a diminuição dos níveis de vitamina D. Conclusões: A diminuição significativa dos níveis de vitamina D 25(OH) na degeneração macular relacionada à idade em estágio avançado sugere a presença de uma correlação significativa entre a deficiência de vitamina D e o desenvolvimento dessa patologia. Mais estudos são necessários para investigar se a suplementação de vitamina D tem ou não influência no desenvolvimento e progressão da degeneração macular relacionada à idade.

Association between age-related macular degeneration and 25(OH) vitamin D levels in the Turkish population.

PURPOSE: Age-related macular degeneration is the most common cause of blindness in developed countries, and several factors have been attributed for its etiology. This study was conducted to explore the relationship between serum vitamin D levels and age-related macular degeneration. METHODS: We retrospectively analyzed the data of 114 patients with age-related macular degeneration. A total of 102 patients who did not have any other diseases than refractive error were allocated to the control group. The best-corrected visual acuity, fundus findings, and spectral domain optical coherence tomography findings were analyzed. Patients were allocated to groups based on the Age-related Eye Disease Study classification. Serum 25(OH) vitamin D levels were measured. The central foveal thickness and the subfoveal choroidal thickness were measured by optical coherence tomography. RESULTS: The 25(OH) vitamin D levels in age- and gender-matched patients with age-related macular degeneration and in healthy subjects were 14.6 ± 9.8 and 29.14 ± 15.1 ng/ml, respectively. The age-related macular degeneration group had significantly lower vitamin D levels than the control group (p>0.001). The subfoveal choroidal thickness was lower in patients with age-related macular degeneration (p>0.001). The 25(OH) vitamin D level showed a weak positive correlation with choroidal thickness (r=0.357, p=0.01). When the level of 25(OH) vitamin D was evaluated according to the stages of age-related macular degeneration, it was found to be lower in the advanced-stage disease (p=0.01). The risk for the development of choroid neovascular membrane and subretinal fibrosis was found to increase with decreased vitamin D levels. CONCLUSIONS: Significantly decreased levels of 25(OH) vitamin D in advanced-stage age-related macular degeneration suggest a significant correlation existing between vitamin D deficiency and age-related macular degeneration development. Further studies are required to examine whether vitamin D supplementation has an effect on the development and progression of age-related macular degeneration.

Utilization of biological variation data in the interpretation of laboratory test results - survey about clinicians' opinion and knowledge.

INTRODUCTION: To interpret test results correctly, understanding of the variations that affect test results is essential. The aim of this study is: 1) to evaluate the clinicians' knowledge and opinion concerning biological variation (BV), and 2) to investigate if clinicians use BV in the interpretation of test results. MATERIALS AND METHODS: This study uses a questionnaire comprising open-ended and close-ended questions. Questions were selected from the real-life numerical examples of interpretation of test results, the knowledge about main sources of variations in laboratories and the opinion of clinicians on BV. A total of 399 clinicians were interviewed, and the answers were evaluated using a scoring system ranked from A (clinician has the highest level of knowledge and the ability of using BV data) to D (clinician has no knowledge about variations in laboratory). The results were presented as number (N) and percentage (%). RESULTS: Altogether, 60.4% of clinicians have knowledge of pre-analytical and analytical variations; but only 3.5% of them have knowledge related to BV. The number of clinicians using BV data or reference change value (RCV) to interpret measurements results was zero, while 79.4% of clinicians accepted that the difference between two measurements results located within the reference interval may be significant. CONCLUSIONS: Clinicians do not use BV data or tools derived from BV such as RCV to interpret test results. It is recommended that BV should be included in the medical school curriculum, and clinicians should be encouraged to use BV data for safe and valid interpretation of test results.

Relationship between right ventricular dilatation and blood copeptin levels in patients with acute pulmonary embolism.

PURPOSE: In this study, we aimed to investigate the importance of copeptin in the diagnosis of acute pulmonary embolism, detection of right ventricular dilatation and clinical severity and prognosis of pulmonary embolism. MATERIALS AND METHODS: In the study three groups were created; Group 1: Pulmonary embolism patients with right ventricular dilatation in echocardiography, Group 2: Pulmonary embolism patients without right ventricular dilatation in echocardiography, Group 3: Healthy people. Five mL of venous blood was collected for the measurement of serum copeptin from the patients and control group. D-dimer and troponin were studied with routine blood samples. Complaints, symptom and physical examination findings, tomography and echocardiography results, laboratory results of patients and treatments they received were recorded for the statistical analysis. RESULTS: Copeptin levels of acute pulmonary embolism patients were significantly higher than healthy individuals (P < 0.001). Copeptin values of Group 1 patients were significantly higher than Group 2 patients and Group 3 patients (P < 0.001). There was a statistically significant difference the levels of copeptin, D-dimer and troponin between patients with right ventricular dilatation and patients without right ventricular dilatation (P < 0.05). AUC value in detecting right ventricular dilatation of copeptin was found to be 0.82, while specificity was 83.3% and sensitivity was 69.6%. Copeptin, D-dimer and troponin levels of patients with increased pulmonary artery pressure were statistically significantly higher than patients with normal pulmonary artery pressure (P < 0.05). CONCLUSION: Copeptin can be used in the diagnosis of acute pulmonary embolism and in the detection of right ventricular dilatation in pulmonary embolism.

Prospective Randomized Study on the Effects of Improved Sleep Quality After Craniotomy on Melatonin Concentrations and Inflammatory Response in Neurosurgical Intensive Care Patients.

OBJECTIVE: Sleep disorders in intensive care units after a craniotomy can decrease melatonin secretion and increase the inflammatory stress response. The aim of this study was to investigate the influence of improving sleep quality via eye patches and earplugs on melatonin secretion and inflammatory mediator release. METHODS: The study enrolled 41 patients who underwent craniotomy. Patients were randomized into 2 groups. "Group Intervention" received a sleep-promoting intervention with eye patches and earplugs to provide light and noise isolation, while "Group Control" received standard care. Blood levels of C-reactive protein and interleukin 1 and interleukin 6 along with urine levels of 6-sulphatoxymelatonin (aMT6) were measured preoperatively (baseline) and on postoperative days 1 and 3. Sleep quality was assessed with the Richards-Campbell Sleep Questionnaire. RESULTS: Sleep quality was higher in the intervention group (Richards-Campbell score:80.61 ± 11.96 vs. 33.50 ± 16.32; P < 0.001). Urine aMT6 levels increased significantly in the intervention group in spot urine samples from 10.15 (5.38-14.40) ng/mL at baseline to 14.52 (6.24-29.11) and 11.51 (7.88-29.05) ng/mL on postoperative days 1 and 3. They also increased in 24-hour urine samples from 25.73 (8.24-52.73) ng/mL at baseline to 35.38 (11.48-95.65) and 39.18 (2.36-125.23) ng/mL on postoperative days 1 and 3 (P = 0.001 and P = 0.005, respectively). The aMT6 concentration did not change significantly in the control group. The C-reactive protein concentrations increased postoperatively compared with baseline concentrations in both groups (P = 0.001 and P < 0.001). CONCLUSIONS: Melatonin secretion significantly increased as a result of improving postoperative sleep quality by noise and light isolation in neurosurgical intensive care unit patients after craniotomy.

Adiponectin levels decrease independently of body mass index and diabetes type after the normalization of hyperglycemia

Background/aim: Acute hyperglycemia is generally a frequently encountered condition in the emergency department (ED), because it is seen as a complication of diabetes mellitus (DM). In this study, we aimed to detect the change in adiponectin levels during acute hyperglycemic states and after normalization of blood glucose with insulin treatment. Materials and methods: Forty-eight patients over the age of 18 years who were admitted to the ED with acute hyperglycemia were included in the study. Serum samples were taken from patients on admission and 6 h after the normalization of blood glucose with insulin treatment, and adiponectin levels were measured in both samples. Results: There were 21 female and 27 male patients with a median age of 58.7 ± 18 years. All patients' blood glucose levels were normalized with insulin treatment according to international recommendations. Serum adiponectin levels decreased significantly after the normalization of blood glucose in the whole group. Adiponectin levels decreased from 28.9 ± 16.5 to 12.1 ± 10.9 µg/mL (P < 0.0001) in the whole group. This decrease was independent of diabetes type and body mass index. Conclusion: Normalization of blood glucose in patients with hyperglycemia caused a decrease in adiponectin levels, independent of diabetes type and/or body weight in an acute emergency setting. Inhibited upregulation of adiponectin secretion and/or blunted suppressive effect of insulin due to hyperglycemia or exogenous insulin administration may have caused the decrease in adiponectin levels.

Investigation of dynamic thiol-disulphide homoeostasis in age-related cataract patients with a novel and automated assay.

PURPOSE: The aim of this study was to determine plasma thiol-disulphide homoeostasis in patients with age-related cataract (ARC) and compare the results of the patients with healthy subjects. Plasma malondialdehyde (MDA) levels and catalase (CAT) activity were also investigated. METHODS: The study included 53 cataract patients and 52 healthy volunteers. Native thiol-disulphide exchanges were determined using a novel and automated method. CAT activity was determined using the method described by Aebi, and MDA levels were calculated using the thiobarbituric acid method. RESULT: Native thiol and total thiol levels were significantly lower in the cataract patients compared with the controls (p < 0.001, p = 0.002, respectively). The disulphide levels of the cataract patients were significantly higher than the controls (p = 0.002). The ratios of disulphide/native thiol and disulphide/total thiol were statistically higher in the cataract patients compared with the control group (p < 0.001, p < 0.001, respectively). Furthermore, CAT activity was significantly lower in the cataract patient group compared with the control group (p < 0.001), and MDA levels were insignificantly higher in the patient group (p = 0.581). CONCLUSIONS: Our study showed that dynamic thiol-disulphide homoeostasis has shifted towards disulphide formation, as a result of thiol oxidation in ARC patients. The present study is the first to measure thiol-disulphide homoeostasis in ARC patients with a novel automated assay. This study supports the hypothesis that cataract is an oxidative disorder. Further studies are required in order to examine the relationship between oxidative stress and the development of cataract formation.

Suppressed Adiponectin Levels and Increased Adiponectin Response to Oral Glucose Load in Lean Women with Severe Acne Normalizes after Isotretinoin Treatment.

BACKGROUND/AIM: Isotretinoin, the drug of choice for severe acne, might be associated with a decrease in insulin sensitivity. Adiponectin is an adipose tissue-derived protein that increases insulin sensitivity. In this study, we aimed to investigate adiponectin levels in postadolescent severe acne and the effect of isotretinoin on adiponectin levels. METHODS: Participants included 18 female patients with severe acne and 18 healthy women matched for age and body mass index (BMI). Acne patients completed a 6-month isotretinoin treatment. Anthropometric measurements, serum adiponectin, lipids, fasting glucose, fasting insulin, and homeostatic model assessment for insulin resistance (HOMA-IR) were determined, and a standard 2-h oral glucose tolerance test (OGTT) was performed in healthy women once and in patients with acne before and after treatment. RESULTS: At baseline, patients with acne had significantly lower serum adiponectin levels than controls. Isotretinoin treatment resulted in a significant increase in weight, BMI, and triglyceride and adiponectin levels. Glucose metabolism markers in patients with acne and controls were similar at baseline and did not change after treatment. Baseline OGTT in acne patients revealed an increased adiponectin response at 2 h, which was not present in healthy controls. Remarkably, this OGTT-induced adiponectin increment in acne patients was diminished after isotretinoin treatment. CONCLUSION: Adiponectin levels are differently regulated in women with severe acne and healthy controls in that circulating basal levels in patients are suppressed and show an increase in response to oral glucose load. Suppression of baseline adiponectin ameliorates after 6 months of isotretinoin treatment, reaching levels similar to those of healthy controls.

Dynamic thiol/disulfide homeostasis in patients with age-related macular degeneration.

PURPOSE:: We evaluated dynamic thiol/disulfide homeostasis (TDH), malondialdehyde (MDA) levels, and catalase (CAT) activity in patients with age-related macular degeneration (AMD). All analyzes were conducted on plasma samples. METHODS:: Thirty-two patients with AMD and 38 age-matched healthy controls were included. Native thiol, total thiol, and disulfide levels and TDH status were determined using a novel, automated assay. MDA levels and CAT activity were determined. Percentages were compared using the chi-squared test. The Student's t-test and Mann-Whitney U-test were used to compare quantitative variables. RESULTS:: Native thiol levels were significantly lower (p=0.004) in patients with AMD (272.02 ± 52.41 µmol/l) than in healthy individuals (307.82 ± 47.18 µmol/l), whereas disulfide levels were significantly higher (p<0.001) in patients with AMD than in controls (21.64 ± 5.59 vs. 14.48 ± 5.37 µmol/L). Dynamic TDH was also significantly lower (p<0.001) in patients with AMD than in controls (13.41 ± 4.3 vs. 25.41 ± 14.52 µmol/l). No significant differences were evident in total thiol or MDA levels. Mean CAT activity was significantly higher (p=0.043) in patients with AMD compared with controls (0.035 vs. 0.018 k/ml). CONCLUSIONS:: The antioxidant/oxidant balance demonstrated by dynamic TDH is shifted to the oxidative side in patients with AMD.

Dynamic thiol/disulfide homeostasis in patients with age-related macular degeneration / Homeostase dinâmica de tiol/dissulfureto em pacientes com degeneração macular relacionada à idade

ABSTRACT Purpose: We evaluated dynamic thiol/disulfide homeostasis (TDH), malondialdehyde (MDA) levels, and catalase (CAT) activity in patients with age-related macular degeneration (AMD). All analyzes were conducted on plasma samples. Methods: Thirty-two patients with AMD and 38 age-matched healthy controls were included. Native thiol, total thiol, and disulfide levels and TDH status were determined using a novel, automated assay. MDA levels and CAT activity were determined. Percentages were compared using the chi-squared test. The Student's t-test and Mann-Whitney U-test were used to compare quantitative variables. Results: Native thiol levels were significantly lower (p=0.004) in patients with AMD (272.02 ± 52.41 µmol/l) than in healthy individuals (307.82 ± 47.18 µmol/l), whereas disulfide levels were significantly higher (p<0.001) in patients with AMD than in controls (21.64 ± 5.59 vs. 14.48 ± 5.37 µmol/L). Dynamic TDH was also significantly lower (p<0.001) in patients with AMD than in controls (13.41 ± 4.3 vs. 25.41 ± 14.52 µmol/l). No significant differences were evident in total thiol or MDA levels. Mean CAT activity was significantly higher (p=0.043) in patients with AMD compared with controls (0.035 vs. 0.018 k/ml). Conclusions: The antioxidant/oxidant balance demonstrated by dynamic TDH is shifted to the oxidative side in patients with AMD.

RESUMO Objetivo: Avaliar a homeostase dinâmica de tiol/dissulfureto e os níveis de malon dialdeído (MDA) e catalase (CAT) em pacientes com degeneração macular relacionada à idade (DMRI). Todas as análises foram realizadas em amostras de plasma. Métodos: Foram incluídos 32 pacientes com degeneração macular relacionada à idade e 38 controles saudáveis de idade similar. Os níveis de tiol, tiol total, dissulfureto e estado de homeostase de tiol/dissulfureto foram determinados utilizando um novo ensaio automatizado. Os níveis de atividade de MDA e CAT foram também determinados. As porcentagens foram comparadas pelo teste do qui-quadrado. O teste t de Student e o teste U de Mann Whitney foram utilizados para comparar variáveis quantitativas. Resultados: Os níveis de tiol nativo foram significativamente menores (p=0,004) nos pacientes com degeneração macular relacionada à idade (272,02 ± 52,41 µmol/l) do que nos indivíduos saudáveis (307,82 ± 47,18 µmol/l), enquan to os dissulfetos foram significativamente maiores em pacientes com degeneração macular relacionada à idade (21,64 ± 5,59 µmol/l versus 14,48 ± 5,37 µmol/l, respectivamente, p<0,001). A homeostase dinâmica de tiol/dissulfureto também foi significativamente menor nos pacientes com degeneração macular re la cionada à idade (13,41 ± 4,3 µmol/l) versus os controles (versus 25,41 ± 14,52 µmol/l, p<0,001). Não foram observadas diferenças significativas nos níveis de tiol total ou MDA. A atividade média de CAT foi significativamente mais elevada (p=0,043) em doentes com degeneração macular relacionada à idade (0,035 k/ml vs. 0,018 k/ml). Conclusões: O equilíbrio antioxidante/oxidante demonstrado pela homeostase dinâmica de tiol/dissulfeto é deslocado para o lado oxidativo em pacientes com de generação macular relacionada à idade.

Thiol Disulfide Homeostasis in Pseudoexfoliation Syndrome.

PURPOSE: To determine the serum thiol disulfide homeostasis in patients with pseudoexfoliation (PEX) syndrome. METHOD: Thirty-five patients with PEX syndrome and forty healthy subjects were included in this observational case-control study. Serum native thiol, total thiol, disulfide, and native thiol/disulfide ratio were determined using a novel and automated assay. RESULTS: The mean serum total thiol and native thiol levels were significantly lower in patients with PEX syndrome compared to healthy controls (p = 0.001). The mean serum disulfide level was significantly higher in patients with PEX syndrome compared to healthy controls (p = 0.023). The serum native thiol/disulfide ratio was lower in patients with PEX syndrome compared to healthy subjects (16 ± 10.1 vs 22.3 ± 11.5, respectively, p = 0.014). CONCLUSION: Our findings provide evidence that the dynamic native thiol/disulfide ratio is lower in PEX syndrome, which shows a reduction in the natural cell reductive capacity reservoir.

Concentrations of prealbumin and some appetite-controlling hormones in pregnancies associated with hyperemesis gravidarium.

Background Hyperemesis gravidarum, which affects 0.3-2.3% of pregnancies, is defined as excessive vomiting during pregnancy and usually starts in week 4 or 5 of gestation. Symptoms include weight loss, dehydration, ketonaemia, ketonuria, fasting acidosis, alkalosis due to hydrochloric acid loss and hypokalaemia and its exact cause is unknown. The present study was undertaken to investigate the relationship between prealbumin, ghrelin, nesfatin-1 and obestatin concentrations in pregnancies associated with hyperemesis gravidarum. Methods A total of 40 pregnant females with hyperemesis gravidarum and 38 pregnant females without hyperemesis gravidarum as controls were included in this study. Serum concentrations of prealbumin, ghrelin, obestatin and nesfatin-1 were measured. Results There were no significant differences in age, gestational week, gravidity and parity between the two groups. Body mass index was significantly lower in cases than in controls. Serum ghrelin and prealbumin concentrations were significantly lower in cases than in controls ( P <0.05 and P < 0.001, respectively). There was no significant difference in serum concentrations of obestatin and nesfatin-1 between the two groups. There was no significant association between body mass index and serum ghrelin, nesfatin-1, obestatin or prealbumin concentrations in patients with hyperemesis gravidarum. Conclusions Decreased serum concentrations of ghrelin and prealbumin in patients with hyperemesis gravidarum are independent of body mass index. Based on our results, we believe that ghrelin may be considered to play a role in the aetiopathogenesis of hyperemesis gravidarum and that hyperemesis gravidarum may result in disruption of the relationship between nesfatin-1 and ghrelin. In addition, we believe that the measurement of serum prealbumin may be used for assessing nutritional status in pregnancy.

Evaluation of the Tosoh G8 Analyzer and Comparison with the Trinity Biotech Premier Hb9210 Analyzer for the Measurement of HbA1c.

BACKGROUND: The aim of our study was to assess the analytical performance of the Tosoh HLC-723G8 automated analyzer and to compare it with the Trinity Biotech Premier Hb9210 analyzer for the measurement of hemoglobin A1c (HbA1c). METHODS: A total of 101 patients with pre-diabetes or diabetes mellitus were included in the study. HbA1c, was measured by both an ion-exchange high-performance liquid chromatography (IE-HPLC) method and a boronate affinity chromatography method. Statistical analysis was performed using Deming regression. Bland-Altman plots were used to calculate mean difference (bias). RESULTS: The CV% values of IE-HPLC and boronate affinity methods for within run and between days were lower than 2.0%. High correlation was found (y = 1.0045x + 0.2111; r = 0.9941) between the two methods. The method shows no interference from carbamylated hemoglobin. CONCLUSIONS: Both systems showed acceptable performance and are suitable for clinical application in the analysis of HbA1c. However, laboratories should be aware of the limitations of their methods and the availability of more accurate and precise HbA1c, determination methods.

Serum prolidase activity and oxidative stress in patients with pseudoexfoliation syndrome.

PURPOSE: We aimed to evaluate the serum prolidase activity (SPA), malondialdehyde (MDA), and catalase levels in patients with pseudoexfoliation (PEX) syndrome. METHOD: Thirty-four patients with PEX syndrome and thirty-eight age- and gender-matched healthy subjects were included in this prospective clinical study. Each participant underwent full ophthalmologic examination. The SPA, serum MDA, and catalase levels were measured and compared between the patients with PEX syndrome and healthy subjects. RESULTS: The SPA was significantly lower in patients with PEX syndrome compared to healthy controls (14.1 ± 7.1 vs. 30.1 ± 4.3 ng/ml; p = 0.001). The mean serum MDA values the of PEX syndrome and control groups were comparable (28.7 ± 5.7 vs. 30.4 ± 5.3 nmol/ml, respectively; p = 0.185). The mean serum catalase level tended to be lower in the PEX group compared to healthy controls (0.12 ± 0.02 vs. 0.21 ± 0.05 k/ml, respectively; p = 0.077). CONCLUSION: Our findings suggest that the SPA was significantly lower in patients with PEX syndrome compared to healthy controls. Thus, prolidase may have a role in the pathogenesis of the PEX syndrome.

Greater Efficiency Observed 12 Months Post-Implementation of an Automatic Tube Sorting and Registration System in a Core Laboratory.

BACKGROUND: Sample classification and registration have been recognized as important and time-consuming processes in laboratories. There is increasing pressure on laboratories to automate processes due to intense workload and reduce manual procedures and errors. The aim of the present study was to evaluate the positive effects of an automatic tube registration and sorting system on specimen processing. METHODS: An automatic tube registration and sorting system (HCTS2000 MK2, m-u-t AG, Wedel, Germany) was evaluated. Turnaround time (TAT), rate of sample rejection and unrealized tests were examined 12 months pre- and post-implementation of the automatic tube sorting and registration system. RESULTS: The mean TAT of routine chemistry immunoassay, complete blood cell count (CBC) and coagulation samples were significantly improved (P<0.001). The number of rejected samples and unrealized tests was insignificantly decreased post-implementation of the system (0.4% to 0.2% and 4.5% to 1.4%, respectively) (P>0.05). CONCLUSIONS: By reducing delays and errors in the preanalytical processing and sorting of samples, significant improvements in specimen processing were observed after implementation of the system. These results suggest that an automatic tube registration and sorting system may also be used to improve specimen processing in a higher-volume core laboratory.

First data on the biological variation and quality specifications for plasma ammonia concentrations in healthy subjects.

BACKGROUND: Most of the factors causing preanalytical and analytical variation in ammonia measurement have been identified. Biological variation data for ammonia is still lacking. We therefore estimated the components of biological variation (within-subject=CVI and between-subject=CVG), reference change value (RCV) and quality specifications for ammonia in a group of healthy individuals using fresh and frozen plasma samples. METHODS: Blood samples from 20 healthy subjects were collected in K2EDTA tubes daily over a period of 4 consecutive days from each subject. Each plasma sample was split into two aliquots; one was immediately analyzed as the samples were collected and the other was stored -80 °C until testing at the end of the collection period and analyzed at once in one analytical run. All samples were analyzed in duplicate. Estimations were calculated according to Fraser and Harris methods. RESULTS: CVI value for fresh samples (13.78%) was significantly lower than that in frozen samples (18.91%) (p<0.001). However, there was no statistically significant difference in CVG values between fresh (16.91%) and frozen (18.43%) samples (p=0.570). The index of individuality did not exceed 1.4 for fresh and frozen samples. The estimated RCVs were high for both fresh and frozen samples (43.37% and 56.85%, respectively). Quality specifications were established. CONCLUSIONS: The present study for the first time described the components of biological variation for ammonia in healthy individuals. These data regarding biological variation of ammonia could be useful for a better evaluation of ammonia test results in clinical interpretation and for determining quality specifications based on biological variation.

Serum vaspin and adiponectin levels in patients with prolactinoma.

BACKGROUND: Studies investigating serum vaspin and adiponectin levels in patients with prolactinoma are inconclusive. The aim of this study was to evaluate serum vaspin and adiponectin levels in patients with prolactinoma and healthy controls. METHODS: A total of 42 prolactinoma patients (Group 1, 21 patients; Group 2, 21 patients) and 30 healthy controls were enrolled in the study. Group 1 consisted of newly diagnosed patients who were never treated or had not received a dopamine agonist (DA) within 6 months prior to screening. Group 2 consisted of prolactinoma patients who were on DA treatment for at least 6 months at the time of screening. The control group (group 3) consisted of healthy controls. RESULTS: Patients with prolactinoma had higher homeostasis model assessment of insulin resistance and lower quantitative insulin sensitivity check index values in comparison to healthy controls (p < 0.001 for both). Serum levels of adiponectin and vaspin were also significantly lower in prolactinoma patients when compared to the control group (p < 0.01 and p < 0.001, respectively). Following adjustment for confounding factors, the respective odds ratios for prolactinoma in patients in the lower subgroup compared with those in the higher subgroup for adiponectin and vaspin were 2.733 (0.621-12.035; p > 0.05) and 5.041 (1.191-21.339; p < 0.05). CONCLUSION: This is the first study to demonstrate the presence of low vaspin levels in patients with prolactinomas. Further studies are needed to help establish the roles of vaspin and adiponectin in prolactinoma patients.

Evaluation of the analytical performance of Unicel DXI 800 for the Total 25 (OH) Vitamin D measurements.

OBJECTIVES: We assessed the analytical performance of newly developed Access 25(OH) Vitamin D Total assay with Beckman Coulter Unicel DXI 800 and evaluated the agreement between a reference method liquid chromatography/tandem mass spectrometry (LC-MS/MS) and a chemiluminescence method (LIAISON, DiaSorin). DESIGN AND METHODS: 160 serum samples were included. Deming Regression analysis and Bland-Altman plots were used. The concordance correlation coefficient (CCC) was used to assess the degree of agreement between assays and the reference method. RESULTS: The CV% values of Unicel DXI 800 for within-run, between-run and between-day were lower than 6%. When compared to LC-MS/MS, the Access 25(OH) Vitamin D Total assay demonstrated an R value of 0.9444 (intercept -0.089, slope 0.951), with an average bias of -2.9%, and the LIAISON 25(OH) Vitamin D Total assay an R value of 0.9405 (intercept -0605, slope 0.924), with an average bias of -13.6%. In comparison with the LIAISON 25(OH) Vitamin D Total assay, the Access 25(OH) Vitamin D Total assay demonstrated an R value of 0.9498 (intercept 0.528, slope 1.029), with an average bias of 1.2%. The agreement with the LC-MS/MS method, based on values of the CCC, was moderate for the Unicel DXI 800 and LIAISON method (0.95, 0.94 respectively). CONCLUSIONS: The new, automated Access 25(OH) Vitamin D Total assay showed an acceptable correlation with LC-MS/MS and LIAISON. Both methods moderately achieved to classify the patients according to their vitamin D status. However, we need further standardization of vitamin D assays to enhance the accuracy and comparability.

YKL-40: may be use as a new inflammatory biomarker in obstructive sleep apnea syndrome?

INTRODUCTION: YKL-40 [chitinase-3 like-1 (CHI3L1)] is a glycoprotein, has been implicated in inflammation, endothelial dysfunction, tissue remodelling and it is accepted as a noninvasive prognostic biomarker for inflammation. In this study, we aimed to underline usability of serum YKL-40 as an inflammatory biomarker in patients with obstructive sleep apnea syndrome (OSAS). PATIENTS AND METHODS: Two groups OSAS patients [Group I: Mild-moderate OSAS, n:43; median apnea-hypopnea index: AHI, /hour:18], Group II: Severe OSAS, n: 25; AHI:41.6] and healthy control group [n:25, AHI: 3.6] were included in the study. Serum YKL-40 level was tested in serum samples taken after polysomnography in OSAS patients and control group. In addition, the association of serum YKL-40 level with age, body mass index and polysomnografic parameters were analyzed in the OSAS patient groups. RESULTS: Median serum YKL-40 level was 20.30 ng/mL (range 8.01-73 ng/mL) in mild-moderate OSAS patients, and 22.58 ng/mL (9.17-99 ng/mL in severe OSAS patients, 18 ng/mL (range 7.36-88 ng/mL) in control group (p< 0.05). Serum YKL-40 level was found to be correlated with AHI in patient with mild-moderate OSAS patients (p< 0.05) and serum YKL-40 level was found to be correlated with age, total hypopnea time (minutes) in severe OSAS patients (p< 0.05). There was no relationship serum YKL-40 level with other studied variables (p> 0.05). CONCLUSION: At the end of this study, we found that serum YKL-40 level increase with severity of OSAS. The findings suggest that YKL-40 may be a useful biomarker for inflammation in patients with OSAS.

The role of reactive oxygen species and oxidative stress in carbon monoxide toxicity: an in-depth analysis.

The underlying mechanism of the central nervous system (CNS) injury after acute carbon monoxide (CO) poisoning is interlaced with multiple factors including apoptosis, abnormal inflammatory responses, hypoxia, and ischemia/reperfusion-like problems. One of the current hypotheses with regard to the molecular mechanism of CO poisoning is the oxidative injury induced by reactive oxygen species, free radicals, and neuronal nitric oxide. Up to now, the relevant mechanism of this injury remains poorly understood. The weakening of antioxidant systems and the increase of lipid peroxidation in the CNS have been implicated, however. Accordingly, in this review, we will highlight the relationship between oxidative stress and CO poisoning from the perspective of forensic toxicology and molecular toxicology.