End-user verification results of two serum separator tubes for clinical chemistry analytes according to CLSI GP34-A and CLSI GP41-A6.

Tube manufacturers use different composition of gels and blood clot activator formulations in serum tube production. Our aim was to investigate the within-tube (repeatability) and between-tube variation, concordance between comparison results of BD and VacuSEL tubes. Blood samples were collected from control subjects (n = 20) and patients (n = 30) in accordance with the CLSI GP41-A6 and CLSI GP34-A guidelines. Twenty-three clinical chemistry parameters were analysed via Roche Cobas C702 Chemistry Analyzer on T0 (0 hour) and T24 (24 hour). Mean differences % were compared with Wilcoxon matched pair test. Clinical significance was evaluated based on desirable bias according to total allowable error (TEa). VacuSEL tubes demonstrated acceptable performance for the results of 20 parameters with regards to desirable bias % limits. Lactate dehydrogenase (LD) [mean difference % (%95 confidence intervals (CI) values of BD and VacuSEL tubes at T0 [6.41% (4.80-8.01%)]; sodium (Na) and total protein (TP) at T24 [-0.27% (-0.46 to -0.07%) and -1.39% (-1.87 to -0.91), respectively] were over the desirable bias limits (LD: 4.3%, Na: 0.23% and TP: 1.36%, respectively) but not exceeding total biological variation CV % [Na: 0.5 (0.0-1.0) % and TP: 2.6 (2.3-2.7) %). %95 confidence intervals (CI) of T0 LD values overlap with within-subject biological variation % (CI) limits (LD: 5.2 (4.9-5.4) %). The differences between two tubes were not medically significant and necessarily conclusive. VacuSEL serum tubes presented comparable performance with BD serum tubes.

Evaluation of Bone Turnover Markers Such as Osteoprotegerin, Sclerostin and Dickkopf-1 in Subclinical Hyperthyroidism.

In this study, it was aimed to assess effects of subclinical hyperthyroidism (SH) on bone metabolism using osteoprotegerin (OPG), sclerostin, Dickkopf-1 (DKK1) and biochemical parameters. This cross-sectional prospective study included 40 patients with SH and 40 euthyroid controls. Serum OPG, sclerostin, DKK-1, type-1 procollagen, C-terminal polypeptide (CTx) and 24-hours urine N-terminal telopeptide (NTx) were measures using ELISA kit. Bone mineral density measurements were performed using dual energy X-ray absorptiometry (DEXA). Risk for 10-years hip and major fracture was estimated by Turkish version of FRAX. No significant difference was detected in age, gender, body mass index, smoking and menopause rates between SH and control groups. The risk for 10-years hip fracture and major osteoporotic fracture were estimated as 4.45% and 0.55% in SH group, respectively. The OPG levels were significantly lower in patients with SH than controls (P = 0.017). No significant difference was detected in other bone formation and degradation parameters. No significant correlation was detected between OPG level and risk for major osteoporotic fracture (P > 0.05); however, a negative correlation was detected between OPG level and risk for hip fracture (rho = 0.233; P = 0.038). Serum OPG is markedly affected in patients with SH. In addition, OPG seemed to be associated with osteoporotic fracture risk. Available data show that SH is significantly associated with risk for fracture; thus, it is important to assess risk for fracture in patients with SH.

Comparison of scoring systems for predicting short- and long-term type 2 diabetes remission after bariatric surgery.

INTRODUCTION: Our study aimed to compare the short- and particularly long-term type 2 diabetes mellitus (T2DM) remission prediction abilities of ABCD, individualised metabolic surgery (IMS), DiaRem2, Ad-DiaRem and DiaBetter scoring systems in Turkish adult type 2 diabetic morbidly obese patients who underwent bariatric surgery. PATIENTS AND METHODS: Our study was planned as a retrospective cohort study. A total of 137 patients with T2DM, including 78 sleeve gastrectomy (SG) and 59 Roux-en-Y gastric bypass (RYGB) patients, were included in the 1st-year evaluation after bariatric surgery, and a total of 115 patients with T2DM, including 64 SG and 51 RYGB patients, were included in the evaluation at the end of the 5th year. RESULTS: In the 1st year after bariatric surgery, area under the ROC curve (AUC) values for diabetes remission scores were 0.863 for Ad-DiaRem, 0.896 for DiaBetter, 0.840 for DiaRem2, 0.727 for ABCD and 0.836 for IMS. At 5 years after bariatric surgery, the AUC values for diabetes remission were 0.834 for Ad-DiaRem, 0.888 for DiaBetter, 0.794 for DiaRem2, 0.730 for ABCD and 0.878 for IMS. CONCLUSIONS: According to our study, the DiaBetter score provided a better AUC value than the other scores both in the short and long term but showed similar predictive performance to Ad-DiaRem in the short term and IMS in the long term. We believe that DiaBetter and Ad-DiaRem scores might be more appropriate for short-term assessment and DiaBetter and IMS scores for long-term remission assessment.

Comparison of three chatbots as an assistant for problem-solving in clinical laboratory.

OBJECTIVES: Data generation in clinical settings is ongoing and perpetually increasing. Artificial intelligence (AI) software may help detect data-related errors or facilitate process management. The aim of the present study was to test the extent to which the frequently encountered pre-analytical, analytical, and postanalytical errors in clinical laboratories, and likely clinical diagnoses can be detected through the use of a chatbot. METHODS: A total of 20 case scenarios, 20 multiple-choice, and 20 direct questions related to errors observed in pre-analytical, analytical, and postanalytical processes were developed in English. Difficulty assessment was performed for the 60 questions. Responses by 4 chatbots to the questions were scored in a blinded manner by 3 independent laboratory experts for accuracy, usefulness, and completeness. RESULTS: According to Chi-squared test, accuracy score of ChatGPT-3.5 (54.4 %) was significantly lower than CopyAI (86.7 %) (p=0.0269) and ChatGPT v4.0. (88.9 %) (p=0.0168), respectively in cases. In direct questions, there was no significant difference between ChatGPT-3.5 (67.8 %) and WriteSonic (69.4 %), ChatGPT v4.0. (78.9 %) and CopyAI (73.9 %) (p=0.914, p=0.433 and p=0.675, respectively) accuracy scores. CopyAI (90.6 %) presented significantly better performance compared to ChatGPT-3.5 (62.2 %) (p=0.036) in multiple choice questions. CONCLUSIONS: These applications presented considerable performance to find out the cases and reply to questions. In the future, the use of AI applications is likely to increase in clinical settings if trained and validated by technical and medical experts within a structural framework.

Elevated serum levels of kynurenine pathway metabolites in patients with Behçet disease.

Behçet disease (BD) is an inflammatory, multisystemic vasculitis of unknown etiopathogenesis. However, innate and adaptive immune system involvement and immune-mediated networks play a vital role in the inflammatory cascade. Indoleamine 2,3-dioxygenase 1 (IDO1) is activated in chronic inflammatory states and catalyzes the first and rate-limiting step of tryptophan (TRP) metabolism along the kynurenine pathway (KP). The study aimed to measure KP metabolites levels in patients with BD and investigate the relationship between disease activity and clinical findings with these metabolites. The study included 120 patients with BD and 120 healthy volunteers. Serum TRP, kynurenine (KYN), kynurenic acid (KYNA), 3-hydroxyanthranilic acid (3HAA), 3-hydroxykynurenine (3HK), and quinolinic acid (QUIN) levels were measured with the tandem mass spectrometric method. Demographic data, clinical manifestations, and disease activity score (BDCAF) were recorded. Serum KYN, KYNA, 3HK, 3HAA, QUIN levels, and KYN/TRP ratio were higher (p < 0.05) in patients with BD compared to the control group, while TRP levels were lower (p < 0.05). KYN/TRP ratio and QUIN levels were significantly higher in the presence of neuro-Behçet, while serum KYN levels were significantly higher in the presence of arthritis (p < 0.05). In addition, serum QUIN levels were significantly higher in the presence of thrombosis (p < 0.05). BDCAF score positively correlated with KYN/TRP ratio. Our findings showed that serum KP metabolite levels were elevated in patients with BD, and there is a relationship between these metabolites with disease activity, clinical findings, and inflammatory burden.

A study on relationship between androgenetic alopecia and cardiovascular risk using high sensitivity C-reactive protein and galectin-3 in men with early onset baldness.

OBJECTIVE: In this study, the objective was to evaluate the cardiovascular and metabolic effects in men with male pattern alopecia beginning before 30 years of age. METHODS: Total of 81 people (41 androgenetic alopecia (AGA) and 40 healthy individuals) were included in the study. Twenty-four-hour ambulatory blood pressure (ABP) measurement, high sensitive C-reactive protein (hsCRP), galectin-3 were studied. Hamilton-Norwood scale (HNS) was used to determine the AGA types of the cases. RESULTS: The mean age in the AGA and control groups was 30.3 ± 7.5 and 30.8 ± 6.0, respectively. Twenty-four-hour ABP measurements, hsCRP, and galectin-3 were similar in both groups. There was a positive correlation between HNS grade with age, BMI, triglyceride levels and fasting blood glucose levels in individuals with AGA. Similarly, there was a positive correlation between HNS grade with daytime pulse wave velocity and night-time reflection magnitude. A significant positive correlation was determined between hsCRP with BMI and waist circumference, and between galectin-3 with BMI, waist circumference, hip circumference, HOMA-IR in individuals with AGA. CONCLUSIONS: This study shows that AGA patients are similar to the normal population in terms of insulin resistance or metabolic syndrome components. However, hsCRP and galectin-3 appear to be associated with cardiovascular disease risk factors in individuals with AGA.

Assessment of the diagnostic performance of the 1 mg dexamethasone suppression test in class 3 obese patients.

Objective. This study was aimed to evaluate the prevalence of Cushing's syndrome and the diagnostic performance of the 1 mg dexamethasone suppression test in class 3 obese patients. Methods. Anthropometric measurements and other laboratory data, including 1 mg dexamethasone suppression test of 753 class 3 obese patients, who applied to the Endocrinology and Metabolism Outpatient Clinic for the pre-bariatric surgery evaluation between 2011 and 2020, were evaluated retrospectively. Results. An abnormal response to the 1 mg dexamethasone suppression test (cortisol ≥1.8 mcg/dl) was observed in 24 patients and the presence of Cushing's syndrome was confirmed by additional tests in 6 patients. The prevalence of abnormal dexamethasone suppression test was 3.18% and the prevalence of Cushing's syndrome 0.79%. The specificity value was determined as 97.5% for 1 mg dexamethasone suppression test with cortisol threshold value ≥1.8 mcg/dl. Conclusions. The prevalence of Cushing's syndrome was found to be low in class 3 obese patients and 1 mg of dexamethasone suppression test had a very sufficient performance for Cushing's syndrome screening in this patient group.

New steps in acute coronary syndrome and antihyperlipidemic treatment: Determination of statins and metabolites by liquid chromatography tandem mass spectrometry.

Our aim in this study was to develop a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the measurement of atorvastatin, rosuvastatin and their major metabolites, and furthermore to evaluate patients' adherence to statin therapy and to investigate the effect of statin therapy on various hematological and biochemical parameters. A simple protein precipitation was performed for the extraction of analytes and the extracted samples were injected directly. The levels of drugs and their metabolites were measured by the validated method in a total of 210 patients diagnosed with unstable angina pectoris (USAP), ST-elevation myocardial infarction (STEMI) or non-ST-elevation myocardial infarction (NSTEMI). Various biochemical and hematological parameters were measured. The linearity ranges for atorvastatin and rosuvastatin were 1.22-2,500 and 0.97-2000 ng/ml, respectively. The inter-assay coefficient of variation for all analytes was ≤ 6%. In patients diagnosed with USAP, STEMI and NSTEMI, treatment compliance rates were 22.1, 23.5 and 41.2% for atorvastatin and 36.1, 40.2 and 67.1% for rosuvastatin, respectively. An economical, simple and reliable measurement method has been developed. Our findings support the poor patient compliance with statin therapy in the included population. It was observed that 6 months of statin treatment caused slight changes in biochemical and hematological parameters.

The Role of Stem Cells Derived From the Mesenchyme of the Umbilical Cord in Reducing Immunosuppressive Drug Doses Used in Allogenic Transplantations.

BACKGROUND: This study evaluated the potential of Wharton's jelly mesenchymal stem cells with high tolerogenic properties in reducing immunosuppressive dosage and related adverse effects. METHODS: A 4- to 6-week-old, 30-40 g weight, male inbred CD57BL/6 mice were used as skin allograft donors, whereas Balb/c mice with similar characteristics were used as recipients. Wharton's jelly stem cells were obtained from a commercial kit sourced from human umbilical cord. Skin allografts were performed from CD57Bl6 to Balb/c mice (day 0). Group 1 (control) received no treatment. Group 2 received 15 mg/kg cyclosporin A on days 0 to 30. Group 3 received 5.7 × 10 6 and 10.3 × 10 6 cell/kg Wharton's jelly stem cells on days 0 and 3, respectively. Groups 4, 5, and 6 received a combination of 15, 10, and 5 mg/kg per day cyclosporine A (days 0 to 30) with the same stem cell dose with group 3, respectively. Graft rejection was evaluated with digital photography and thermal imaging, histopathology (Banff grading, epithelialization scores, dermoepidermal dissociation), immunochemistry (Ki-67 and Bcl-2), and biochemical methods (interleukin 10, interleukin 2, interferon γ, tumor necrosis factor α) (day 10). Cumulative adverse effects of cyclosporin A occurring in the groups were revealed by histopathological evaluation of kidney and liver (a modified semiquantitative method of infiltration of inflammatory cells around the portal area and lobular region in liver; modification of the Banff rating of proximal tubules and hypertrophia of juxtaglomerular apparatus cells in kidney) (day 30). RESULTS: There was no rejection in groups 2, 4, and 5 until the end of study. These were statistically different versus groups 1 (day 10 ± 0.71), 3 (day 11 ± 0.82), and 6 (day 11 ± 0.58) (all P 's < 0.05). Groups 4 and 5 have exhibited statistically similar findings in histopathological (4 epithelization score: 3.7 ± 1.3; 5 epithelization score: 3.5 ± 0.5; 4 Banff grading score: 0.8 ± 0.6; 5 Banff grading score: 1.0 ± 0.5; both P 's = 1.00), immunohistochemical (4 Bcl-2 score: 3.5 ± 0.5, P = 0.618; 5 Bcl-2 score: 3.4 ± 0.5, P = 1.00; 4 Ki-67 score: 3.7 ± 0.4, P = 1.00; 5 Ki-67 score: 3.5 ± 0.5, both P 's = 1.00), and levels of cytokines (both P 's = 1.00) versus group 2. Adverse effects on kidneys and liver were lowest and statistically similar in groups 3, 5, and 6 (all P 's = 00) versus group 1. CONCLUSIONS: Wharton's jelly mesenchymal stem cells alter bioavailability of cyclosporine, albeit at much lower doses and with fewer systemic adverse effects.

Altered kynurenine pathway metabolite levels in toddlers and preschool children with autism spectrum disorder.

AIM: There are increasing reports about the potential role of kynurenine pathway metabolites in autism spectrum disorder (ASD). Early childhood is a very crucial period of time for the etiopathogenesis of ASD and previous studies reported an age-dependent alteration in kynurenine metabolism. However, no study specifically examined kynurenine metabolites in very young children with ASD. This study aimed to investigate kynurenine pathway metabolite levels, kynurenine pathway enzyme activities and neuroprotective index (kynurenic acid/3-hydroxykynurenine ratio) in toddlers and preschool children with ASD. MATERIALS AND METHODS: A total of 68 children with ASD and 44 healthy controls aged between 18 and 60 months were included in this study. Serum levels of kynurenine pathway metabolites were determined by liquid chromatography-mass spectrometry/mass spectrometry system. RESULTS: Serum 3-hydroxykynurenine and kynurenic acid concentrations were significantly higher in the ASD group than in the control group, whereas serum 3-hydroxyanthranilic acid concentrations were significantly lower. CONCLUSIONS: These findings showed that the kynurenine pathway may play a role in the etiopathogenesis of ASD in early childhood.

Quantification of serum homoarginine, methylated arginine and inhibin-A levels in a high-risk pregnancy.

The plasma levels of homoarginine (h-Arg) and methylated arginine have proven to be an independent cardiovascular risk factor. We aimed to determine the h-Arg and methyl arginine levels in serums of high-risk pregnancy causing potential complications. These participants were divided into four groups as the control group with quadruple test, the high-risk group quadruple test the control group with binary test, the high-risk group with quadruple test that have a positive result from second-trimester screening with a cut-off value of 1 in 300. The serum methyl arginine and homoarginine levels were analysed with liquid chromatography-tandem mass spectrometry. Serum h-Arg levels were found to be higher in high-risk groups compared to control groups and it was also detected higher in the groups with quadruple test than the groups with binary test (p < .05). H-Arg levels in the groups showed strong negative correlation with age and serum inhibin-A levels (r = -0.288, p < .001). Also, there was a strong negative correlation between serum asymmetric dimethylarginine (ADMA) and serum inhibin-A levels (r = -0.352, p < .001). H-Arg may be a new risk marker to detect high-risk pregnancies in early pregnancy. In addition to, methylated arginine such as ADMA has a key regulator in a physiological concentration of h-Arg.IMPACT STATEMENTWhat is already known on this subject? H-Arg levels decrease may be associated with preeclampsia, GDM, macrosomia, low birth weight, and preterm delivery in pregnancy.What do the results of this study add? Serum h-Arg levels were found to be higher in high-risk groups. Additionally, h-Arg levels and ADAM, one of the methylated arginines in the groups showed a strong negative correlation with serum inhibin-A levelsWhat are the implications of these findings for clinical practice and/or further research? H-Arg may be a new risk marker to detect high-risk pregnancies.

Determination of serum methylarginine levels by tandem mass spectrometric method in patients with ankylosing spondylitis.

Our aim in this study was to measure serum levels of methylarginines and related metabolites in patients with ankylosing spondylitis (AS), moreover, to investigate the relationship between these parameters and various clinical and laboratory parameters of patients with AS. The study included 60 patients with AS and 60 healthy volunteers. Serum asymmetric dimethylarginine (ADMA), L-N monomethylarginine (L-NMMA), symmetric dimethylarginine (SDMA), arginine (Arg), homoarginine (hArg), ornithine, and citrulline concentrations were measured with tandem mass spectrometry. In addition, participants were divided into three groups according to the treatment regimen: TNF-α inhibitor group (n = 25), conventional therapy group (n = 35), and control group (n = 60). These groups were compared in terms of serum levels of methylarginine pathway metabolites and various biochemical parameters. It was found that total methylated arginine load significantly increased in patients with AS (p < 0.001), and the Arg/ADMA ratio was positively correlated with HDL levels and negatively correlated with glucose, ESR, total cholesterol, triglyceride, and LDL levels. In addition, serum ADMA, SDMA, total methylated arginine load, and CRP levels were lower (p < 0.05) in the TNF-α group compared to the conventional treatment group. To the best of our knowledge, this is the first study to comprehensively investigate serum methylarginine levels in patients with AS. Elevated total methylated arginine load and decreased global arginine bioavailability ratio (GABR) indicate that NO metabolism is impaired in patients with AS. Therefore, the increased cardiovascular risk in patients with AS may be related to the decreased NO production or bioavailability due to the elevated total methylarginine load.

Effects of hydroxychloroquine and its metabolites in patients with connective tissue diseases.

Hydroxychloroquine has attracted attention in the treatment of COVID-19. Many conflicting findings have been reported regarding the efficacy and safety of this drug, which has been used safely in the rheumatological diseases for years. However, these studies lacked measurement methods that allow accurate assessment of hydroxychloroquine and its metabolite levels. The aim of this study was to measure hydroxychloroquine and its metabolite levels in whole blood samples of patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), Sjogren's syndrome (SS) and scleroderma (Scl) by a robust, simple and accurate validated tandem mass spectrometric method, and to investigate the relationship between these levels with drug-related adverse effects and disease activity scores. The validated LC-MS/MS method was applied to measure blood hydroxychloroquine and its metabolite levels of patients with RA, SLE, SS, Scl. Various haematological and biochemical parameters were measured with Beckman-Coulter AU 5800 and Beckman Coulter LH 780 analyzers, respectively. QTc intervals were calculated with Bazett's formula, and the patients were followed up by clinicians in terms of clinical findings and adverse effects. Hydroxychloroquine levels of patients were similar to previous studies. There was a negative correlation between disease activity scores and hydroxychloroquine levels, while the highest correlation was between QTc interval, creatinine and GFR levels with desethylchloroquine. Bidetylchloroquine had the highest correlation with RBC count and liver function tests. Our findings showed that hydroxychloroquine and its metabolite levels were associated with disease activity scores, renal, hepatic function, QTc prolongation, and hematological parameters.

Association of depressive symptoms with 25(OH) vitamin D in hemodialysis patients and effect of gender.

BACKGROUND: Depression is common in chronic kidney disease (CKD) patients and associated with significant increase in morbidity and mortality. In recent years, a relationship between vitamin D deficiency and depression has been shown. The aim of this study is to investigate the relationship between 25-hydroxy (OH) vitamin D and depression in hemodialysis patients. METHODS: A total of 140 patients were included in the study. Hamilton depression scale (HAM-D) was completed by all patients. 25(OH) vitamin D levels were compared between patients with and without depressive symptoms. RESULTS: Patients who had depressive symptoms had significantly lower 25(OH) vitamin D levels (13.70 [24.3-8.25] vs. 18.20 [29.2-11.7] ng/mL, p = 0.016). HAM-D score showed significant association with gender (p = 0.011) and 25(OH) vitamin D level (p = 0.011). Univariate logistic regression analysis showed that males had lower risk of depression by a ratio of 61.1% (OR 0.389, p = 0.012) and vitamin D-deficient patients had 2.88 times greater risk of depression compared to non-deficient patients (OR 2.885, p = 0.013). Multivariate logistic regression analysis showed that males had 53.7% less risk of depression (OR 0.463, p = 0.046) and vitamin D-deficient patients had 2.39 times greater risk of depression (OR 2.397, p = 0.047). When evaluated by gender, univariate logistic regression analysis showed that 25(OH) vitamin D and other variables were not associated with depression in females (p > 0.05), while only vitamin D level had a significant effect on depression in males (OR 8.207, p = 0.008). CONCLUSIONS: We found a significant association between vitamin D level and depressive symptoms in hemodialysis patients. When analyzed according to gender, this association was found to stand independent of other variables only in males.

Total methylated arginine load as a risk parameter in subjects with masked hypertension.

Asymmetric dimethylarginine, symmetric dimethylarginine, and L-monomethylarginine are originated from the subsequent proteolytic catalysis of methylated arginine residues on different proteins and inhibit the endogenous nitric oxide generation. The changes in total methylarginine load (Asymmetric dimethylarginine plus symmetric dimethylarginine plus L-monomethylarginine) may contribute to hypertension. The aim of this study was to determine serum methylarginine concentrations in patients with masked hypertension and determine the association between these biomarkers and blood pressure measurements. Control group, masked hypertension and hypertension groups consisted of 40 subjects (11 males, 28 females, mean age 48.6 ± 13.1), 28 subjects (14 males, 14 females, mean age 50.9 ± 11.0) and 36 subjects (15 males, 21 females, mean age 54.4 ± 12.3 years), respectively (P= 0.149). Serum total methylarginine load was significantly higher in hypertension group (0.63 ± 0.23) compared to masked hypertension (0.49 ± 0.16) and control groups (0.38 ± 0.13) (P= 0.008 and P< 0.001). While there was no statistically significant difference between healthy control groups [0.147 (0.03-0.29)] and masked hypertension patients [0.144 (0.05-0.42)] for serum symmetric dimethylarginine levels (P= 0.970), it was markedly elevated in hypertension group [0.25 (0.07-0.54)] compared to masked hypertension group [0.14 (0.05-0.42)] (P= 0.001). Serum total methylarginine load was positively correlated with night-time SBP (r = 0.214, P= 0.029). Serum methylarginine levels might be a useful marker for determining the courses of clinical hypertension.

Comparison of Immunoassay and Liquid Chromatography-Tandem Mass Spectrometry Methods in the Measurement of Serum Androstenedione Levels.

BACKGROUND: Recent reports have described inherent problems with androgen immunoassays compared with mass spectrometry analyses. In this study, a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed according to CLSI rules. The developed method was compared with two immunoassay methods, the enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA). METHODS: After liquid-liquid extraction, a Shimadzu Prominence LC unit coupled to an ABSCIEX API 3200 mass spectrometer with atmospheric pressure chemical ionization was used to quantify serum androstenedione levels. Serum androstenedione results taken from tandem mass spectrometry were compared with the immunoassays. RESULTS: The androstenedione assay was linear up to 50 ng/mL. Lower limit of quantitation and lower limit of detection were 0.195 ng/mL and 0.097 ng/mL, respectively. This method was not affected by matrix effect and other steroid hormone interferences. In this study, the obtained recovery was 69 - 99%, carryover value was determined as 0.026 ng/mL. According to the results of an interference study, androstenedione bias % did not exceed the limit of allowable bias % and 88.7% recovery was acquired for androstenedione. In the LC-MS/MS and ELISA comparison study, the slope value was found as 18.412, intercept -22.87, and r2 value as 0.1033. In the LC-MS/MS and RIA comparison study, slope value was found as 1.085, intercept 0.4541, and r2 value as 0.3712. In the RIA and ELISA comparison study, slope value was found as 9.57, intercept -15.5, and r2 value as 0.19. CONCLUSIONS: The LC-MS/MS provides agreement with the results of radioimmunoassay but not with ELISA. This method offers better selectivity compared to immunoassay systems.

Serum levels of neopterin in gestational diabetes mellitus: the relationship with Apgar scores.

PURPOSE: This study was designed to evaluate neopterin levels and low Apgar scores in pregnancies with gestational diabetes mellitus (GDM) vs. normal control pregnancies. METHODS: We carried out a cross-sectional study by enrolling 81 pregnant women with GDM and 38 pregnant women without GDM. RESULTS: Maternal and cord blood neopterin levels were higher in women with GDM. There was a significant positive association between fasting blood glucose levels and maternal serum neopterin levels. The results of 50-g oral glucose challenge tests revealed a correlation between maternal and cord neopterin levels. Pregnancies complicated by GDM exhibited lower fetal Apgar scores than those of control subjects. The levels of cord blood neopterin were inversely correlated with an fetal Apgar score of 1 min in patients with GDM. CONCLUSIONS: Patients with GDM had higher maternal and cord blood neopterin levels, and the cord blood neopterin levels are inversely associated with lower Apgar scores in women with GDM. The neopterin levels might be potential predictors of low fetal Apgar scores in women with GDM.

Prolactin levels in manganese-exposed male welders.

PURPOSE: Early studies on manganese (Mn) exposure have demonstrated that this transition metal affects dopamine neurotransmission. Dopamine serves as a tonic inhibitor of prolactin release in the anterior hypophysis. Our aim was to determine the relation between serum prolactin levels and manganese-exposure. METHODS: Whole blood was collected from 95 non-exposed control subjects and 179 manganese-exposed male welders. Whole blood manganese was analyzed by Inductively Coupled Plasma--Mass Spectrometer on Agilent 7700 (Agilent Technologies, USA). Serum prolactin levels (PRL), aspartate transaminase (AST), alanine transaminase (ALT), urea, creatinine, soduim (Na), potassium (K) were analyzed by immunological and spectrophotometric methods on Roche E170 Modular System (Roche Diagnostics, Mannheim, Germany). RESULTS: The mean ages for control and manganese-exposed group were 40.5 ± 7.8 and 39.5 ± 8.7, respectively (p = 0.258). The mean working period (years) for control and manganese-exposed group were 17.4 ± 9.8 and 18.2 ± 7.7 years, respectively (p = 0.581). Serum AST and potassium levels were significantly higher in control group than manganese-exposed group (p = 0.002 and p = 0.048, respectively) and body-mass index (BMI) was significantly lower in control group than manganese-exposed group (p = 0.033). There was a significantly positive correlation between whole blood manganese levels and serum prolactin (r = 0.860, p < 0.001). Serum ALT levels were positively correlated with serum AST, urea and sodium (r = 0.315, p < 0.001; r = 0.121, p = 0.046; r = 0.130, p = 0.031). CONCLUSIONS: Serum prolactin level is a diagnostic marker for determining the effect of manganese-exposure.

Comparison of Labsan Tricell-1000 and Dirui FUS-2000 automated urine analyzers with manual microscopy.

Objectives: Urinalysis is a first-line test for screening for urinary tract infection. Several devices performing strip and sediment analysis have been introduced. The aim of this study was to compare the performance of Labsan Tricell-1000 and Dirui FUS-2000 automated urine analyzers with manual microscopy. Methods: 463 urine samples were analyzed. Digital image processing and particle recognition automatically display the cells in a flowing sheath fluid mixed monolayer urine sample, take the pictures of particles via digital camera, analyse these pics with a particle recognition software, transfer images of the formed elements to the screen and allow well-trained personnel to select, reclassify or remove them. Manual microscopy was used for comparison. Results: Agreement between Tricell-100 and manual microscopy was very good for RBC (Ï° = 0.80), and WBC (Ï° = 0.83); good for CaOx (Ï° = 0.69), SEC (Ï° = 0.80), YLC (Ï° = 0.72), HC (0.69) and LC (Ï° = 0.64); moderate for BAC (Ï° = 0.51), APC (Ï° = 0.43) and MT (Ï° = 0.55); fair for GC (Ï° = 0.39) and RTEC (Ï° = 0.32). Conclusions: Labsan Trion TriCell-1000 demonstrated satisfactory performance and can be used in routine urinalysis. In the case of low counts of RBC, presence of yeast, crystal, casts or cell clumping in urine sediment, characterization of urine particles should be performed by manual microscopy.

Measurement of kynurenine pathway metabolites by tandem mass spectrometry.

Objectives: Recent studies have shown that derangements in kynurenine pathway metabolite levels are associated with various pathologies such as neurodegenerative diseases, schizophrenia, depression, bipolar disorder, rheumatoid arthritis, and cancer. Therefore, reliable, accurate, fast, and multiplex measurement methods for kynurenines have become increasingly important. This study aimed to validate a new mass spectrometric method for analyzing tryptophan metabolites. Methods: A tandem mass spectrometric method, including protein precipitation and evaporation steps, was developed to measure serum levels of tryptophan, kynurenine, kynurenic acid, 3-hydroxykynurenine, and 3-hydroxyanthranilic acid. Samples were separated using a Phenomenex Luna C18 reversed-phase column. The kynurenine pathway metabolites were detected by tandem mass spectrometry. The developed method was validated according to Clinical & Laboratory Standards Institute (CLSI) guidelines and applied to hemodialysis samples. Results: The developed method was linear at the concentrations of 48.8 - 25,000, 0.98 - 500, 1.2-5000, 1.2-5000, and 0.98-250 ng/mL for tryptophan, kynurenic acid, kynurenine, 3-hydroxyanthranilic acid, and 3-hydroxykynurenine, respectively. The imprecisions were less than 12 %. The median serum concentrations of tryptophan, kynurenine, kynurenic acid, 3-hydroxykynurenine, and 3-hydroxyanthranilic acid were 10530, 1100, 218, 17.6, and 25.4 ng/mL in pre-dialysis blood samples, respectively. They were 4560, 664, 135, 7.4, and 12.8 ng/mL in post-dialysis blood samples, respectively. Conclusions: A fast, simple, cost-effective, accurate, robust, and validated tandem mass spectrometric method was developed, and the method was successfully used for the quantitation of kynurenine pathway metabolite concentrations in hemodialysis patients.