Efficacy of Phenylalanine- and Tyrosine-Restricted Diet in Alkaptonuria Patients on Nitisinone Treatment: Case Series and Review of Literature.

INTRODUCTION: Nitisinone used in alkaptonuria (AKU) can result in keratopathy due to strongly increased tyrosine levels. METHODS: This study aimed to investigate nutritional status and changes in plasma tyrosine and phenylalanine and urinary homogentisic acid (u-HGA) levels in 8 adult AKU patients (mean age, 56.3 ± 4.7 years) who were on tyrosine/phenylalanine-restricted diet together with 2 mg/day nitisinone. RESULTS: The treatment period was 23.4 ± 6.9 months. Daily dietary protein intake was restricted to 0.8-1.0 g/kg/day. Daily tyrosine intake was restricted to 260-450 mg/day for females and 330-550 mg/day for males. Tyrosine/phenylalanine-free amino acid supplements accounted for an average of 56.1% of daily protein intake. The following assessments were performed: anthropometric and plasma tyrosine level measurements every 2 months; ophthalmological examination every 6 months, and nutritional laboratory analyses and measurements of plasma amino acids and u-HGA once in a year. It was targeted to keep the plasma tyrosine level <500 µmol/L. The plasma tyrosine level was <100 µmol/L before the treatment in all patients and around a mean of 582.5 ± 194.8 µmol/L during the treatment. The diet was rearranged if a plasma tyrosine level of >700 µmol/L was detected. The u-HGA level before and after the 1st year of treatment was 1,429.3 ± 1,073.4 mmol/mol creatinine and 33.6 ± 9.5 mmol/mol creatinine, respectively. None of the patients developed keratopathy or experienced weight loss and protein or micronutrient deficiency. CONCLUSION: AKU patients should receive tyrosine/phenylalanine-restricted diet for reducing plasma tyrosine level to the safe range. Tyrosine/phenylalanine-free amino acid supplements can be safely used to enhance dietary compliance. Keratopathy and nutrient deficiency should be frequently monitored.

Validation of an In-House-Developed GC-MS Method for 5α-Cholestanol According to ISO 15189:2012 Requirements.

OBJECTIVE: The aim of this study was to validate a gas chromatography-mass spectrometry (GC-MS) method for the measurement of 5α-cholestanol in the clinical laboratory in agreement with ISO 15189:2012. MATERIALS AND METHODS: The GC-MS performance was evaluated and proficiency testing data were used to estimate the measurement uncertainty of the method considering the recommendations of international guidelines. RESULTS: The calibration curves were linear from 6 to 50 µmol/L, with r2 >.99. The limit of detection and limit of quantitation were determined to be 0.36 and 2.58 µmol/L, respectively. The bias ranged from -18.9% to 15.2% for 6.5, 18.3, and 66 µmol/L. The intra- and interassay reproducibility was <20% at the various concentrations studied. The expanded uncertainty was determined to be 50.9%. CONCLUSION: The GC-MS method for the measurement of 5α-cholestanol has proved to have acceptable analytical performance for use in the clinical laboratory.

Associations Between Bioavailable Vitamin D and Remnant Cholesterol in Patients With Type 2 Diabetes Mellitus.

Introduction In circulation, 99% vitamin D is transported by binding to vitamin D binding protein (VDBP) and albumin. Vitamin D at free form and vitamin D binding to albumin are defined as bioavailable vitamin D. Vitamin D deficiency is associated with atherogenic lipid profile and insulin resistance. Remnant cholesterol is defined as the cholesterol component of triglyceride-rich lipoproteins and contributes to the atherosclerotic burden. The aim of this study was to investigate the association between bioavailable vitamin D and remnant cholesterol in patients with type 2 diabetes mellitus (T2DM). Methods A total of 198 T2DM patients and 208 non-diabetic subjects underwent biochemical measurements of lipid profiles, 25(OH)D, VDBP, CRP and albumin levels. Their demographic characteristics (age, sex) were questioned. Subjects with thyroid, kidney and liver dysfunction and using lipid-lowering therapy were not included in the study. The diagnosis of T2DM was made according to the American Diabetes Association ADA 2016 criteria. Classification of vitamin D levels was done according to the Endocrine Society. Bioavailable vitamin D concentrations were calculated. Results High-density lipoprotein cholesterol (HDL), 25(OH)D, free vitamin D and bioavailable vitamin D levels were significantly lower in diabetic patients than in non-diabetic patients while triglyceride, remnant cholesterol and CRP levels were found to be significantly higher. VDBP was positively correlated with CRP and remnant cholesterol in diabetic patients, but not in non-diabetic patients. Cut-off values were determined from non-diabetics as 3.56 ng/mL for bioavailable vitamin D and 26.56 mg/dL for remnant cholesterol. Logistic regression analysis in the control group showed that the odds ratio for increasing remnant cholesterol above the cut-off value was determined as 2.01 for low bioavailable vitamin D and 1.1 for elevated CRP. However, in T2DM there was no significant relationship. In all subjects, low bioavailable vitamin D increased the remnant cholesterol above the cut-off by 2.18-fold independent of the presence of T2DM. However, there was no significant risk to increase remnant cholesterol, considering a total 25(OH) D deficiency in all groups. Conclusions Low bioavailable vitamin D was found to be a risk factor for elevated remnant cholesterol. This relationship was not detected in patients with T2DM. We believe that the inflammation observed in Diabetes Mellitus may increase the concentrations of VDBP and a decrease in bioavailable vitamin D levels. Therefore, measuring VDBP and calculating the bioavailable vitamin D may provide additional information about the actual vitamin D status.

Diagnostic value of glycemic markers HbA1c, 1,5-anhydroglucitol and glycated albumin in evaluating gestational diabetes mellitus.

BACKGROUND: The oral glucose tolerance test (OGTT) is the current established method performed worldwide to diagnose gestational diabetes mellitus (GDM). The purpose of this study was to assess the utility of the use of long- and short-term markers of glycemic status. METHODS: The study group was composed of 80 pregnant women, 40 with GDM and 40 with normal glucose tolerance. GDM was diagnosed with the American Diabetes Association criteria. Glycemic markers were measured in the OGTT blood samples of women at 24-28 weeks of gestation. RESULTS: HbA1c was significantly higher in the GDM group when compared with the controls, whereas 1,5-anhydroglucitol (1,5-AG) levels were significantly lower. There was not a significant difference between the groups for glycated albumin. Whereas HbA1c levels were correlated with fasting and 1 h glucose and negatively correlated with mean corpuscular volume, 1,5-AG was only negatively correlated with the first hour glucose. No difference was found for the diagnostic performances of HbA1c and 1,5-AG (receiver operating characteristic of the area under the concentration curve values were 0.756 and 0.722, respectively). CONCLUSION: HbA1c and 1,5-AG alone does not have sufficient diagnostic accuracy to diagnose GDM. 1,5-AG values were correlated with post-load glucose values in pregnant women so will improve the GDM management and be useful to predict complications.

Adiponectin levels in gestational diabetes mellitus and in pregnant women without glucose intolerance.

OBJECTIVES: The aim of the study was to determine serum adiponectin levels among patients with gestational diabetes mellitus (GDM) and normal pregnant women without glucose intolerance, and to investigate the relationship between these levels and clinical factors at the time of the diagnosis, at delivery and in the post-partum period. MATERIAL AND METHODS: The subjects' serum adiponectin concentration was measured using the enzyme-linked immunosorbent assay (ELISA) method at 24th-28th week of gestation, at delivery (in maternal circulation and the umbilical cord) and 24 h after delivery. The relationship between these groups' measurements and other established clinical-laboratory factors were investigated. RESULTS: Serum adiponectin concentrations were significantly lower (p = 0.02) in GDM patients compared with patients with normal glucose tolerance at 24th-28th week of gestation. During delivery, maternal serum adiponectin concentrations were significantly lower (p = 0.03) in GDM patients compared with patients with normal glucose tolerance. In the post-partum period, serum adiponectin concentrations were significantly higher (p = 0.009) in GDM patients compared with patients with normal glucose tolerance. Umbilical cord adiponectin concentrations were significantly lower (p = 0.005) in GDM patients compared with patients with normal glucose tolerance. CONCLUSIONS: Adiponectin concentrations in GDM patients' circulation were regulated by changes in glucose and insulin metabolism. A reduction in serum adiponectin levels seems to play a role in GDM patients' insulin resistance.

The cooling effect on proinflammatory cytokines interferon-gamma, tumor necrosis factor-alpha, and nitric oxide in patients with multiple sclerosis.

Multiple sclerosis (MS) is the most common inflammatory demyelinating disease of the central nervous system (CNS) in young adults. The proinflammatory cytokines such as interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and nitric oxide (NO) which are known to be produced by inflammatory cells play a key role in the pathogenesis of MS. Some metabolic changes may have an effect on axonal transmission, and white blood cells NO and other inflammatory mediators such as cytokines may be affected from cooling process. In this study, we evaluated the effects of body cooling procedure on proinflammatory cytokines such as TNF-α, IFN-γ, and NO levels. Twenty patients with MS were evaluated. Thirteen of the patients were women, 7 were men (mean age: 33.6 ± 7.5 yrs.). Body temperature was reduced by an average of 1°C approximately in 1 hour with using the "Medivance Arctic Sun Temperature Management System" device. In our study, the decrease in TNF-α, IFN-γ levels after the cooling procedure has no statistical significance, whereas the decrease in the mean level of NO level after the cooling procedure is 4.63 ± 7.4 µmol/L which has statistical significance (P = 0.002). These results suggested that the decrease in NO level improves conduction block in demyelinated axonal segments after cooling procedure in multiple sclerosis.

Effect of laparoscopic excision of endometriomas on ovarian reserve: serial changes in the serum antimüllerian hormone levels.

OBJECTIVE: To investigate the effect of laparoscopic endometrioma stripping on serum antimüllerian hormone (AMH) and the correlation between the clinicopathologic factors. DESIGN: Prospective study. SETTING: University hospital. PATIENT(S): Sixty-five women with endometriomas. INTERVENTION(S): All patients underwent laparoscopic cystectomy. Serum AMH, FSH, LH, E(2), and antral follicle count (AFC) were measured preoperatively, at 6 weeks, and at 6 months postoperatively. Specimens were analyzed histopathologically. MAIN OUTCOME MEASURE(S): The primary end point was to assess the ovarian reserve damage based on alterations of AMH and the secondary end point was to detect the changes in FSH, LH, E(2), and AFC. RESULT(S): Serum AMH decreased significantly at the sixth month (61%) postoperatively. The FSH level increased significantly at the sixth week, but returned to normal at the sixth month. The AFC increased significantly at the sixth week and at the sixth month. The AMH level decrease was more evident in patients with the cyst <5 cm (65.7% vs. 41.3%). The AMH decrease was more in bilateral compared with unilateral endometriomas (67% versus 57%, respectively). No correlation was detected between the histopathologic analyses and tAMH level. Initially the AMH level was the only independent factor affecting the AMH decrease (odds ratio, 3.68; 95% confidence interval 1.66-8.14). CONCLUSION(S): Laparoscopic cystectomy of ovarian endometriomas causes a significant and progressive decline in serum AMH levels.

The relation of serum ghrelin, leptin and insulin levels to the growth patterns and feeding characteristics in breast-fed versus formula-fed infants.

The differences in growth patterns in breast-fed (BF) and formula-fed (FF) infants remain poorly understood. The aim of this study was to examine the relation of serum ghrelin and leptin concentrations to the different growth patterns between the formula-fed and breast-fed babies. Feeding behaviors and anthropometric data were noted at the 3rd and 6th months of age. Serum ghrelin and leptin levels in both groups and breast-milk ghrelin and leptin levels in the mothers of the BF group were determined at the 3rd month of age. Body weight, length, TSF (triceps skin fold thickness), postnatal weight gain, and serum ghrelin levels were higher in BF babies than in the FF group. In BF babies, serum ghrelin was correlated to TSF, and serum leptin was correlated to weight, TSF and weight gain at three months of age. As the serum leptin increased, energy intake from supplemental foods decreased in the BF group at the 6th month. Higher serum ghrelin in BF babies might have played a role in their faster growth rate during the first three months of age. On the other hand, lower energy intake from supplemental foods in correlation with higher serum leptin in BF babies may explain why these babies show marked decline in growth rate compared to FF babies after three months of age.

Health profiles of methyl bromide applicators in greenhouses in Turkey

<p><b>INTRODUCTION</b>Methyl bromide is a toxic substance that has hazardous effects on human health with acute and chronic exposure. Our previous study showed that methyl bromide applicators frequently use large amounts of methyl bromide haphazardly in greenhouses in the prefectures of Narlidere and Balcova in the Aegean city of Izmir. This study aims to evaluate the health conditions of these workers.</p><p><b>MATERIALS AND METHODS</b>Our previous study showed that there are 38 methyl bromide applicators in our study area. After the informed consent of methyl bromide applicators was obtained, a questionnaire was used for a survey of demography and symptoms. Each subject was examined before and after application of the compound. Blood and urine samples were collected and stored. Blood samples were analysed for methyl bromide and bromide ion, kidney and liver function tests and lipid profile.</p><p><b>RESULTS</b>The age range of subjects was 19 to 53 years (mean age: 41 +/- 8.57). This study showed that methyl bromide applicators use large amounts of methyl bromide disregarding legal regulations and that some of them had nonspecific complaints. Subjects had been working as methyl bromide applicators for approximately 9.7 +/- 4.15 years. A total of 69.7% of methyl bromide applicators reported that they did not use protective equipment while 33.3% of them had a history of acute methyl bromide intoxication. A statistically significant relationship was found between the usage of protective equipment and the level of blood bromide ion in the blood (P <0.05).</p><p><b>CONCLUSION</b>Usage of methyl bromide, training, screening and follow-up of applicators must be rigorously controlled in accordance with national legal arrangements and international protocols. Greater efforts are required in the implementation of controls to achieve the targets set by the legal regulations and to ensure continual improvement in the limitation of the risks of this environmental hazard.</p>

Fate of abstracts presented at the 2002 IFCC meeting.

BACKGROUND: Poster presentations at major meetings serve to rapidly present and share study results with the scientific community. On the other hand, full-text publication of abstracts in peer-reviewed journals provides dissemination of knowledge. The purpose of this study was to evaluate the publication rate of abstracts presented at the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Meeting, to assess the factors influencing publication and determine the impact factor of these journals. METHODS: All poster abstracts presented at the 2002 IFCC Meeting were included in the study. A Medline search was performed to identify a matching journal article. Topics, country of origin, study type, study center and publication year were tabulated. Journals and impact factors of publication were noted. RESULTS: Out of 900 presented abstracts, 125 (13.9%) were published as full-text articles. Publication rates according to topics of the meeting, country of origin and university affiliation demonstrated significant differences. Abstracts from multi-centered studies had higher publication rates, and the journals they were published in had higher impact factors than single center studies. The median impact factor of the journals was 2.093. According to regression analysis, the major predictors for publication were interventional research and university affiliation (odds ratios 2.916 and 1.782, respectively; p < 0.05). CONCLUSIONS: The publication rate for abstracts of this clinical chemistry meeting was lower than rates from other fields of medicine. Factors leading to failure require elucidation. Encouraging authors to submit their presentations for full-text publication might improve the rate of publication.

Effects of oral L-arginine supplementation on blood pressure and asymmetric dimethylarginine in stress-induced preeclamptic rats.

This study was carried out to elucidate the role of asymmetric dimethylarginine (ADMA) and nitric oxide (NO) in preeclampsia development, and to investigate the effect of L-arginine supplementation in rats. Preeclampsia was induced in pregnant rats using a stress model. L-arginine was administered orally and ADMA, urinary nitrate, and protein levels were measured on the 20th day of pregnancy. Compared with the group of rats that are normally pregnant, the levels of blood pressure (BP), protein excretion, and ADMA were significantly increased in preeclampsia which returned to normal levels following the supplementation of L-arginine. Both group of rats had similar urine nitrate levels. Arginine-ADMA-NO pathway is affected in preeclampsia. L-arginine supplementation decreased hypertension (HT), proteinuria, and ADMA levels indicating that taking L-arginine may be beneficial in preeclampsia treatment.

Effect of intravenous iron sucrose on oxidative stress in peritoneal dialysis patients.

AIM: Intravenous iron therapy is an accepted treatment for patients receiving hemodialysis and continuous ambulatory peritoneal dialysis (CAPD). Studies have found enhanced oxidative stress in hemodialysis patients receiving intravenous iron, but there are no clinical data for CAPD patients. The aim of the current study was to investigate the effect of 100 mg of intravenous iron-sucrose on the erythrocyte (RBC) antioxidant enzymes (namely, superoxide dismutase [SOD], catalase [CAT], and glutathione peroxidase [GSHPx]) and plasma malondialdehyde (MDA), an oxidant molecule, in CAPD patients. METHODS: Twelve CAPD patients receiving maintenance intravenous iron-sucrose were recruited. After a 12-hour fast, blood samples were taken for hemoglobin, iron, ferritin, and high-sensitivity C-reactive protein (hsCRP), and for baseline activities of erythrocyte antioxidant enzymes (i.e., SOD, CAT, GSHPx) and the plasma oxidant molecule, MDA. 100 mg iron-sucrose was infused over 30 minutes. Blood samples taken during (i.e., 15 minutes after commencement of infusion) and after (i.e., at 30 minutes, 60 minutes, and 6 hours after commencement) the infusion were taken for measurement of plasma iron, ferritin, TSAT, RBC SOD, CAT, GSHPx, and plasma MDA. RESULTS: Plasma iron and transferrin saturation elevated significantly during infusion (p < 0.05). There was no significant change in erythrocyte SOD, CAT, GSHPx, or in MDA activities. There was a reduction of GSHPx activity at the 30th minute (from 153.69 +/- 66.69 to 123.68 +/- 25.50 mU/mL), but it was not statistically significant. The patients were grouped according to baseline ferritin (100-400 and 400-800 ng/mL); 60th-minute MDA was significantly higher in the latter group (p < 0.05). There was no correlation between hsCRP and oxidant-antioxidant balance. No correlation was noted between RBC antioxidant enzymes or plasma oxidant molecule and ferritin levels. CONCLUSION: There are no acute deteriorating effects from a 100 mg of intravenous iron-sucrose in CAPD patients with optimal iron stores. This dose may be applied safely in CAPD patients.