Verification studies of tryptophan and kynurenine determination using HPLC and evaluation of the kynurenine pathway and neopterin levels in human colostrum samples.

Colostrum, the first breast fluid produced by mammals after giving birth, is followed by breast milk, which serves as the sole source of nutrients for breastfed newborns and infants. Tryptophan, an essential amino acid, plays a crucial role in the development and maturation of the central nervous system in infants. Tryptophan is primarily degraded through the kynurenine pathway. Owing to its sensitivity to dietary intake, immune-mediated tryptophan degradation is assessed by the kynurenine-to-tryptophan ratio, with a focus on one of the rate-limiting enzymes in the pathway. This study involved the validation of the simultaneous determination of tryptophan and kynurenine using HPLC. The validated method was then used to detect levels of tryptophan and kynurenine, as well as to calculate the kynurenine-to-tryptophan ratio in colostrum samples. Simultaneously, these results were compared with colostrum neopterin levels measured using commercial enzyme-linked immunosorbent assay kits. The mean levels for tryptophan, kynurenine, and neopterin were 17.3 ± 62.4 µM, 0.45 ± 0.03 µM, and 28.9 ± 2.6 nM, respectively. This study is among the few that have evaluated these parameters in colostrum samples. Neopterin levels secreted by the mammary gland were found not to be correlated with tryptophan degradation, a process influenced by the mother's nutritional status.

Synthesis and Tyrosinase Inhibitory Activity of Novel Benzimidazole/Thiazolidin-4-one Hybrid Derivatives.

In this study, novel 3-(phenylamino)thiazolidin-4-one 2 a-d and 3-(phenyl)thiazolidin-4-one 3 a-g derivatives which are having benzimidazole moiety were synthesized and their tyrosinase inhibitory activity were investigated. The structures of the target compounds were elucidated using 1 H/13 C-NMR, IR and MS. The structure of 2 b was also characterized using HSQC NMR technique. Among the target compounds, 3 b-g demonstrated stronger tyrosinase inhibitory activity (IC50 values for 3 b-g ranged from 80.93 to 119.20 µM), compared to the positive control kojic acid (IC50 : 125.08 µM). With IC50 value of 80.93 µM, 5-(2-(4-(1H-benzimidazol-1-yl)phenyl)-4-oxothiazolidin-3-yl)-2-methylbenzenesulfonamide 3 g was found to be the most active derivative of the series. Molecular docking studies were conducted to elucidate the binding interactions between compounds and tyrosinase. The MTT assay studies used to determine the cytotoxicity of 3 b-g showed that 3 c, 3 d, 3 f and 3 g were not cytotoxic in the range of 0-200 µM. Considering its tyrosinase inhibitory activity and cytotoxic effect, 3 g exhibits promising potential for further research and development as a novel tyrosinase inhibitor.

Evaluation of neopterin levels and kynurenine pathway in patients with acute coronary syndrome.

BACKGROUND: Coronary atherosclerosis is the leading cause of coronary artery disease. Several investigations have indicated that tear-sensitive plaques contain macrophages and T cells. Neopterin is an essential cellular immune response biomarker. The main goal of this study was to see if there were any changes in biomarkers like unconjugated pteridines, neopterin, and biopterin, as well as kynurenine pathway enzymes like indoleamine 2,3-dioxygenase (IDO), which catalyzes the rate-limiting step in tryptophan degradation, in patients with the acute coronary syndrome (ACS) caused by angiographic atherosclerosis. METHODS: High-performance liquid chromatography was used to determine the amounts of neopterin, biopterin, and creatinine in urine samples, as well as tryptophan and kynurenine in serum samples. The enzyme-linked immunosorbent assay was used to assess the amounts of neopterin in serum samples. The measured parameters were evaluated between ACS patients and controls. RESULTS: The measured levels of neopterin, biopterin and the kynurenine to tryptophan ratio reflecting IDO activity, and the specifically known biomarkers such as cardiac troponin, creatine kinase, myoglobin, and natriuretic peptides are statistically higher in ACS patients compared to control subjects. On the other hand, the measured parameters are inadequate to classify the conventional kinds of ACS, ST-elevation- and non-ST-elevation- myocardial infarction. CONCLUSIONS: The study found that determining and using neopterin and IDO parameters as biomarkers in individuals with the ACS can support traditional biomarkers. However, it can be concluded that evaluating pteridine biomarkers solely have no privilege to clinical findings in ACS diagnosis and classification.

Urine neopterin in childhood acute demyelinating diseases: Potential for differential diagnosis.

Inflammatory demyelinating diseases of the central nervous system (CNS) in childhood include clinically and radiologically defined diseases such as acute disseminated encephalomyelitis (ADEM), multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disorder (MOGAD). Differentiation between these phenotypes can be difficult and cases not meeting established diagnostic criteria may remain without any specific diagnosis for months. Laboratory markers can assist in the diagnosis and management of these diseases. Previous studies suggest serum kynurenine-tryptophan pathway products and serum neopterin as biomarkers for CNS autoimmune diseases. Because urine is a reliable and repeatable source for analysis of these products with the additional advantage of easy sampling, we measured neopterin concentrations in serum and urine samples, urinary biopterin and serum kynurenine-tryptophan levels in autoimmune demyelinating diseases of CNS: pediatric multiple sclerosis (pMS, n = 27), MOGAD (n = 10), NMOSD (n = 5) patients and a control group consisting of healthy children or children with non-inflammatory diseases (n = 13), total 55 children. Methods were high performance liquid chromatography (HPLC) for neopterin, biopterin and creatinine in urine and kynurenine and tryptophan in serum; ELISA was used for serum neopterin. Comparison for biomarkers between all diagnostic groups showed urinary neopterin values were significantly higher in the pMS group (p = 0.002). The cut-off point determined by ROC analysis indicated urinary neopterin >167.75 µmol/mol creatinine could distinguish the patients from the controls with a sensitivity of 71% and specificity of 90%. The most significant difference was between the pMS and control groups (p = 0.002) while no difference was observed between pMS patients who were in relapse or stable state. Therefore, urinary neopterin appeared as a potential marker that could differentiate pMS from other demyelinating patient groups MOGAD and NMOSD as well as from controls. The fact that pteridine pathway products had not been studied in urine and serum in children with demyelinating disease before highlights the novelty of this study. If further research in larger samples confirm the present results, these molecules might assist the differential diagnosis of pMS from other demyelinating CNS diseases.

Neopterin and biopterin levels and tryptophan degradation in patients with diabetes.

This study aimed to evaluate the possible changes of neopterin, biopterin levels and tryptophan degradation in diabetes and to compare the results within diabetes groups and with healthy subjects. Diabetes mellitus patients and healthy controls were recruited the study. Patients were further subgrouped according to their drug therapy. Serum neopterin concentrations were detected by ELISA. Urinary neopterin, biopterin, serum tryptophan (Trp) and kynurenine (Kyn) levels were detected by HPLC. There was no difference between controls and diabetes patients in serum neopterin, urinary neopterin and biopterin levels (p > 0.05, all). Serum Trp and Kyn levels were significantly different in type 1 diabetes (T1DM) patients compared to controls (p < 0.05, both). Serum neopterin levels were significantly higher in type 2 diabetes patients (T2DM) compared to T1DM (p < 0.05). Urinary biopterin levels of T2DM patients using both metformin and vildagliptin were significantly higher than T1DM patients (p < 0.05). The correlations between serum neopterin and urinary neopterin, Kyn and Kyn/Trp were statistically significant in control and patient groups (p < 0.05, all). The study showed that Kyn/Trp was altered in diabetes patients due to immune modulation. On the other hand, although xenobiotic exposure may change pteridine levels, metformin and/or vildagliptin use in T2DM patients did not have any effect on the measured parameters.

Evaluation of isoindole derivatives: Antioxidant potential and cytotoxicity in the HT-29 colon cancer cells.

Norcantharimides have an isoindole skeleton structure, and some isoindoline derivatives have positive effects on inflammatory pathologies, including cancers. The present study aims to evaluate the antioxidant and cytotoxic potential of four synthesized isoindoline derivatives (NCTD1-4). HT-29 cells exposed to 10, 50, 100, and 200 µM doses of each derivative were incubated for 24 and 48 h, respectively. The cytotoxicity of the new derivatives was analyzed using the cell growth inhibition assay and the cell membrane damage test. In vitro antioxidant activity studies showed that the derivatives have free radical-scavenging effects in a dose-dependent manner. NCTD3 and NCTD4 apparently have antioxidant effects when compared with the control group treated with dimethyl sulfoxide. Furthermore, NCTD4 inhibited the growth of the HT-29 cells due to membrane damage and exhibited a dose-dependent cytotoxic effect on colon adenocarcinoma cells. The findings suggest that NDTD4 has the highest potential for colon cancer treatment and may be interpreted as a candidate anticancer agent.

The increased neopterin content in turkish pediatric patients with sickle cell anemia.

In the present study, the possible activation of cellular immunity in SCD patients was investigated. As immune activation parameters, neopterin concentrations and kynurenine/tryptophan ratio for tryptophan degradation in 35 pediatric patients with sickle cell disease (31 HbSS and 4 HbSß) were determined. Our results have shown that neopterin levels (both urinary and serum) are increased in pediatric patients with sickle cell disease. The increase in neopterin concentration was accompanied by significantly increased biopterin, kynurenine concentration and kynurenine/tryptophan ratio. The mechanism of immune activation and the effects of inflammatory mediators in sickle cell disease are poorly understood, especially in terms of cell-mediated immunity. Further in-vivo and in-vitro studies are required to illuminate the association between neopterin levels and neutrophil activation in sickle cell disease.

Mycotoxin Detection in Maize, Commercial Feed, and Raw Dairy Milk Samples from Assiut City, Egypt.

This survey was conducted to investigate the contamination by multiple mycotoxins, aflatoxins (AFB1, AFB2, AFG1, and AFG2), ochratoxin A (OTA), and zearalenone (ZEA) in 61 samples of maize and 17 commercial animal feed samples, and of aflatoxin M1 (AFM1) in raw dairy milk samples (n = 20) collected from Assiut City in Upper Egypt. Multi-mycotoxin immunoaffinity columns were used for samples cleanup and mycotoxin purification. An HPLC-FLD system with an on-line post-column photochemical derivatization was used for the detection of the target toxins. AFB1 was detected in both maize (n = 15) and feed (n = 8), with only one maize sample presenting a concentration above the maximum permissible level set by the Egyptian authorities. AFB2 was observed in six maize samples and in one feed sample, with a maximum value of 0.5 µg/kg. ZEA was detected only in feed samples (n = 4), with a maximum value of 3.5 µg/kg, while OTA, AFG1, and AFG2 were under the limits of detection. For milk, all the analyzed samples (100%) were contaminated with AFM1, and 14 samples (70%) presented concentrations above the maximum permissible level in the European Union (EU) (0.05 µg/kg). The concentrations ranged from 0.02 µg/kg to 0.19 µg/kg, except that of one sample, which was under the limit of quantification. The contamination rates in maize and animal feeds are not alarming. In contrast, the consumption of dairy milk samples in Assiut City may pose public health hazards, as AFM1 levels were found to exceed the international permissible limits. Further surveys are highly recommended in order to establish a database for mycotoxin occurrence in Egypt to minimize the possible health risks in animals and humans.

Neopterin Levels and Indoleamine 2,3-Dioxygenase Activity as Biomarkers of Immune System Activation and Childhood Allergic Diseases.

BACKGROUND: Although Th2 immune activation is predominant in allergic diseases, neopterinlevels and indoleamine 2,3-dioxygenase (IDO)-1 activity (kynurenine:tryptophan ratio), which reflect Th1 immune activity, increase with interferon-gamma (IFN-γ) stimulation. We investigated neopterin, tryptophan, and kynurenine levels as biomarkersof the Th1 immune system activation and changes in IDO-1 activityin children with asthma, allergic rhinitis, and atopic dermatitis, as well as the relationship between these biomarkers and the total IgE level, age, and disease severity. METHODS: We divided 205 children (80 girls and 125 boys, four months to 17 years old) into four groups: controls, patients with asthma, patients with allergic rhinitis, and patients with atopic dermatitis. Peripheral venous blood samples were collected. Neopterin levels were determined by an enzyme immunoassay. Tryptophan and kynurenine levels were analyzed using HPLC. IDO-1 enzyme activity was calculated using tryptophan and kynurenine levels. IgE levels were measured. The Mann-Whitney U test, Kruskal-Wallis test, and Conover post-hoc method were used for statistical analysis. RESULTS: Neopterin, tryptophan, and kynurenine levels were higher and IgE levels and IDO-1 enzyme activity were lower in patients with asthma and allergic rhinitis than in controls (P<0.05). Patients with atopic dermatitis showed higher neopterin, tryptophan, and kynurenine levels, higher IDO-1 activity, and lower IgE levels thancontrols (P<0.05). CONCLUSIONS: The Th1/Th2 balance is disrupted in children with allergic diseases, concomitant with increased Th1-mediated immune response activation and reduced IgEproduction, which is promoted by Th2-type cytokines.

Male infertility in Sertoli cell-only syndrome: An investigation of autosomal gene defects.

OBJECTIVES: To detect autosomal genetic defects and to determine candidate genes in Sertoli cell-only syndrome infertile men. METHODS: Single-nucleotide polymorphism + comparative genomic hybridization microarray technology was carried out on 39 Sertoli cell-only syndrome infertile patients in the present study. Array comparative genomic hybridization compares the patient's genome against a reference genome, and identifies uncover deletions, amplifications and loss of heterozygosity. RESULTS: A link between defective spermatogenesis genes and infertility was examined, and amplifications and deletions in several genes were detected, including homeobox gene; synaptonemal complex element protein 1; collagen, type I, alpha 1; imprinted maternally expressed transcript; and potassium voltage-gated channel subfamily Q member 1. CONCLUSIONS: The present data suggest that several genes can play an important role in spermatogenesis and progression of Sertoli cell-only syndrome.

Tryptophan Degradation and Antioxidant Status in Patients With Thyroid Disorders.

BACKGROUND: The aim of this study was to evaluate the degradation of tryptophan (Trp), neopterin production and antioxidant capacity in patients with benign and malignant thyroid disease. METHODS: For this reason, the levels of tryptophan, kynurenine (Kyn) and neopterin, and superoxide dismutase (SOD) and catalase (CAT) enzyme activities in 67 thyroid patients were evaluated in our study and the results were compared with 30 healthy controls. RESULTS: Tryptophan and kynurenine levels in thyroid patients decreased compared to the control group. Patients with thyroid disease had lower CAT activity than the control group. The neopterin and tryptophan levels in malignant and benign patients were also significantly different. CONCLUSION: The results of the present study suggest that thyroid disorders may lead to changes in tryptophan degradation, neopterin production and CAT enzyme activities.

Possible changes of New-Generation inflammation markers with occupational lead exposure.

OBJECTIVES: Occupational lead (Pb) exposure is still an important health problem in the world. Long-term Pb exposure causes several adverse effects. The aim of this study was to investigate the changes of inflammation markers with chronic Pb exposure by analyzing neopterin levels and kynurenine (Kyn) to tryptophan (Trp) ratio that reflects indolamine 2,3-dioxygenase activity and to compare with healthy volunteers' parameters. METHODS: Blood lead levels (BLLs) were analyzed by atomic absorption spectrometry. Urinary neopterin and serum Kyn and Trp levels were analyzed by high-performance liquid chromatography. RESULTS: According to our results, mean BLL of the 29 workers was 20.4±9.6 µg/dl. Urinary neopterin levels, serum Kyn levels, and Kyn/Trp of Pb workers (188±52 µmol/mol creatinine, 2.70±0.66 µM, and 43.19±10.38 µmol/mmol, respectively) were significantly higher than controls (144±35 µmol/mol creatinine, 2.08±0.34 µM, and 32.24±7.69 µmol/mmol, respectively). Pb-exposed workers were divided into further three groups according to their BLLs: as 10-19 µg/dl (n=18), 20-29 µg/dl (n=8), and 30-49 µg/dl (n=3). Neopterin levels of the workers with BLL of 30-49 µg/dl were significantly higher than those of BLL with 10-29 µg/dl, while Trp levels decreased. Kyn/Trp of workers with BLL of 30-49 µg/dl were elevated significantly compared with the workers with BLL<30 µg/dl. In addition to neopterin, Kyn and Kyn/Trp levels were positively influenced by Pb exposure. CONCLUSIONS: Increased level of inflammation markers confirms the adverse effects of Pb even low BLLs, and we suggest that monitoring BLLs with inflammation markers could help to prevent serious occupational health problems.

A New Diagnostic and Prognostic Marker in Endometrial Cancer: Neopterin.

OBJECTIVE: In this study, we investigated the correlation between serum and urinary neopterin levels as well as the stage of the disease in women with endometrial cancer.Increased neopterin concentrations are reported in patients with activation of macrophages by interferon-γ, which includes the following: viral infections, autoimmune disorders, allograft rejection, and various malignant tumors. In patients with several types of cancer, high-neopterin concentrations in body fluids like serum/plasma, urine, ascites, and cerebrospinal fluid indicate the course of the disease, and it is associated with poor prognosis. In the light of foregoing, we aimed to investigate the role of neopterin as a prognostic biomarker in endometrial cancer. MATERIALS AND METHODS: Serum neopterin concentrations were determined by enzyme-linked immunosorbent assay and urinary neopterin by high-performance liquid chromatography in 41 patients with endometrial cancer (group 2) and 41 healthy women (group 1). RESULTS: Increased urinary neopterin levels were observed in patients with endometrial cancer (P < 0.001), and the difference in the urinary neopterin levels between low and high stages of endometrial cancer was significant (P < 0.01; stage I-II vs stage III-IV, respectively). Serum neopterin levels did not show a significant difference in each group. CONCLUSIONS: This study suggests that urinary neopterin levels are relevant in evaluating the endometrial cancer stage and follow-up of the disease. As a result, using neopterin and cancer antigen 125 together would be useful in determining the prognosis of endometrial cancer and its posttreatment progression.

Occurrence of multiple mycotoxins and other fungal metabolites in animal feed and maize samples from Egypt using LC-MS/MS.

BACKGROUND: The present study aimed to investigate the occurrence of multiple toxic fungal and bacterial metabolites in 156 animal feed (n = 77) and maize (n = 79) samples collected from three regions in Upper Egypt. The target analytes were quantified using the 'dilute and shoot' approach, followed by a liquid chromatography tandem mass spectrometry analysis. RESULTS: In total, 115 fungal and bacterial metabolites were detected in both matrices, including the regulated mycotoxins in the European Union, in addition to the modified forms such as deoxynivalenol-3-glucosid. Furthermore, some Fusarium, Alternaria, Aspergillus and Penicillum metabolites beside other fungal and bacterial metabolites were detected for the first time in Egypt. All of the samples were contaminated with at least four toxins. On average, 26 different metabolites were detected per sample with a trend of more metabolites in feed than in maize. The maximum number of analytes observed per samples was 54 analytes at maximum concentrations ranging from 0.04 µg kg-1 for tentoxin to 25 040 µg kg-1 for kojic acid. CONCLUSION: According to the international standards, the contamination rates in the investigated regions were not alarming, except for AFB1 in maize. The necessity of further and continuous monitoring is highly recommended to establish a database for mycotoxin occurrence. © 2017 Society of Chemical Industry.

Neopterin Release and Tryptophan Degradation in Patients with Uveitis.

PURPOSE: Uveitis is an intraocular inflammation affecting the highly vascularized uveal tissue. Early recognition and appropriate therapeutic intervention of uveitis are important since the condition may be associated with systemic disease and untreated uveitis may lead to blindness. Neopterin, an unconjugated pteridine, is an important biomarker of cell-mediated immunity and has a potential function in the process of inflammation. In addition to neopterin release, cellular immune activation also induces indoleamine 2,3-dioxygenase (IDO). In this study, the aim was to investigate possible immune changes in uveitis by determination of neopterin concentrations and tryptophan (Trp) degradation. MATERIALS AND METHODS: The participants who attended to the ophthalmology clinic with uveitis were divided into two groups: active (n = 63) and remission (n = 41). Additionally 30 healthy subjects were recruited as a control group. RESULTS: In total, in 104 uveitis patients, urinary and serum neopterin, kynurenine (Kyn), and Kyn/Trp were found to be statistically higher than the 30 controls (all, p < 0.05). It was observed that all of the measured parameters did not differ between active and remission uveitis groups (all, p > 0.05), except for the Kyn/Trp ratio (p < 0.05). Urinary and serum neopterin levels were positively correlated with Kyn/Trp in the uveitis patients (both p < 0.05). CONCLUSIONS: From these results, it can be concluded that uveitis can cause alterations in neopterin levels and the Kyn pathway. It seems that the measured parameters can be useful markers of cellular immune response in uveitis, although they might not be used to differentiate active or remission uveitis.

The effects of a small-dose ketamine-propofol combination on tourniquet-induced ischemia-reperfusion injury during arthroscopic knee surgery.

STUDY OBJECTIVE: To determine the effects of a small-dose ketamine-propofol combination used for sedation during spinal anesthesia on tourniquet-induced ischemia-reperfusion injury. STUDY DESIGN: Prospective randomized study. SETTING: Training and research hospital. PATIENTS: 60 adult, ASA physical status 1 and 2 patients, ages 20-60 years, scheduled for elective arthroscopic knee surgery for meniscal and chondral lesions. INTERVENTIONS: The initial hemodynamic parameters were recorded and blood samples were collected at baseline (T1); then spinal anesthesia was performed. In Group I (n=30), a combination of 0.5 mg/kg/hr of ketamine and 2 mg/kg/hr of propofol was administered; Group II (n=30) received an equivalent volume of saline as an infusion. A pneumatic tourniquet was applied. MEASUREMENTS: Malondialdehyde (MDA), superoxide dismutase (SOD), and catalase levels were measured one minute before tournique deflation in the ischemic period (T2), then 5 (T3) and 30 (T4) minutes following tourniquet deflation in the reperfusion period. MAIN RESULTS: No differences were noted between groups in hemodynamic data (P > 0.05) or SOD levels (P > 0.05). In Group I, MDA levels at T2 were lower than in Group II (P < 0.05). In Group I, catalase levels were lower at T2 and T4 than they were in Group II (P < 0.05). CONCLUSION: Small-dose ketamine-propofol combination may be useful in reducing tourniquet-induced ischemia-reperfusion injury in arthroscopic knee surgery.

Immunomodulation and oxidative stress in denim sandblasting workers: changes caused by silica exposure.

Workers in denim sandblasting are at a high risk of developing silicosis, an occupational lung disease caused by inhaling crystalline silica dust. The development and progress of silicosis is associated with the activation of the immune system and oxidative stress. In the former, interferon-gamma induces both neopterin release and the enzyme indoleamine [2, 3]-dioxygenase (IDO) in various cells. The determination of the kynurenine-to-tryptophan ratio and neopterin concentration has proven to be an efficient method to monitor the activation status of IDO and cellular immunity. The present study aimed to investigate whether occupational silica exposure leads to any alterations in neopterin levels, tryptophan degradation, and activities of superoxide dismutase (SOD) and catalase (CAT), agents in the antioxidant defense system. Fifty-five male denim sandblasting workers and twenty-two healthy men as controls were included. Mean neopterin and kynurenine levels, kynurenine-to-tryptophan ratio, and SOD activity were higher in subjects with silicosis compared to non-exposed controls (all, p<0.05). Neopterin levels and kynurenine-totryptophan ratios were positively correlated (p<0.05); however, no correlation was observed between length of employment and the measured parameters. Some of the measured parameters were significantly affected by the severity of the pathology. Our results suggest that silica exposure activates the cellular immune response. The increased neopterin levels and tryptophan degradation confirm the possibility of their use as an indicator of cellular immune response.

A pilot study on neopterin levels and tryptophan degradation in zinc-exposed galvanization workers.

Hot-dip galvanization is a zinc-coating process to protect the metal items from corrosion. Zinc oxide nanoaerosol fume rising from hot metal bath surface in nano dimensions contains the greatest risk for workers in galvanization process. In the present study, it was evaluated whether inhalation of zinc causes any alteration in cellular immunity and tryptophan degradation by measuring neopterin, tryptophan, kynurenine, and zinc levels in 63 male galvanization workers and 23 male office personnel as controls. Serum and urinary zinc levels were found as 102.43 ± 4.74 and 0.66 ± 0.05 µg/dL in workers while 75.45 ± 4.24 and 0.80 ± 0.08 µg/dL [corrected] in controls, respectively (both, p < 0.05). Similarly, the mean urinary neopterin levels and serum neopterin and kynurenine levels were found to be statistically higher in galvanization workers than the controls (all, p < 0.05). Significant correlations were found between urinary neopterin levels and kynurenine to tryptophan ratio or serum zinc levels. The results indicated cellular immune activation by occupational zinc exposure. It was estimated that neopterin, in parallel with kynurenine pathway, could reflect occupational exposure to zinc nanoaerosols and might be useful in early diagnosis of immune alterations due to nano-scale exposures.

Evaluation of tetrahydrobiopterin pathway in operating room workers: changes in biopterin status and tryptophan metabolism.

The aim of the study was to evaluate the effect of anesthetics as operating room contaminants on tetrahydrobiopterin pathway in 40 operating room personnel and 30 healthy controls by measuring biopterin, dihydrobiopterin reductase, tryptophan, kynurenine and serotonin. Biopterin concentrations were 124 ± 12.3 µmol/mol creatinine in workers and 88 ± 5.7 µmol/mol creatinine in controls whereas kynurenine concentrations were 1.75 ± 0.09 µM and 1.95 ± 0.06 µM, respectively (both, p < 0.05). It can be claimed that enhanced biopterin and diminished kynurenine levels may play a triggering role in disruption of metabolic events in operating room personnel.

Toxic metals in breast milk samples from Ankara, Turkey: assessment of lead, cadmium, nickel, and arsenic levels.

Toxic metals are one of the significant groups of chemical contaminants that humans are exposed to by oral, inhalation, and dermal routes. Exposure to these chemicals begins with intrauterine life and continues during lactation period at the first years of life. Breastfeeding has a much more special place than other nutrition options for infants. However, when possibility of contaminant transfer by breast milk is considered, its safety and quality is essential. Regarding infant and mother health and limited number of information on this field in Turkey, measuring contamination levels in breast milk is important. Therefore, in the present study, lead (Pb), cadmium (Cd), nickel (Ni), and arsenic (As) levels were measured by atomic absorption spectrometry in 64 breast milk samples obtained from mothers from Ankara, Turkey. Pb and Ni levels in breast milk samples were found to be 391.45±269.01 µg/l and 43.94±33.82 µg/l (mean ± SD), respectively. Cd was found only in one of 64 samples, and the level was 4.62 µg/l. As level was below the limit of quantification (LOQ, 7.6 µg/l) in all samples. These findings will accurately direct strategies and solutions of protection against contaminants in order to reduce their levels in biological fluids.