Age-Related Progression of Microvascular Dysfunction in Cystic Fibrosis: New Detection Ways and Clinical Outcomes

There are concerns about altered vascular functions that could play an important role in the pathogenesis and influence the severity of chronic disease, however, increased cardiovascular risk in paediatric cystic fibrosis (CF) has not been yet fully understood. Aim was to analyse vascular disease risk and investigate changes over times in CF and controls. We prospectively enrolled 22 CF subjects (a median age of 16.07 years), and 22 healthy demographically matched controls (a median age of 17.28 years) and determined endothelial function. We utilised a combined diagnostic approach by measuring the plethysmographic Reactive Hyperemia Index (RHI) as the post-to preocclusive endothelium-dependent changes of vascular tone, and biomarkers that are known to be related to endothelial dysfunction (ED): asymmetric dimethyl arginine (ADMA), high-sensitive CRP (hsCRP), VCAM-1 and E-selectin. RHI values were significantly lower in CF young adults (p<0.005). HsCRP (p<0.005), E-selectin (p<0.001) and VCAM-1 (p<0.001) were significantly increased in CF patients since childhood. The findings have provided a detailed account of the ongoing process of microvascular dysfunction with gradual progression with the age of CF patients, making them further at risk of advanced vascular disease. Elevations of biomarkers in CF children with not yet demonstrated RHI changes but with significantly reduced RHI in adulthood and lipid profile changes indicate the possible occurrence of ED with CF-related specific risk factors over time and will enable us to provide the best possible support.

Asymmetric Dimethyl Arginine Level in Children with Sickle Cell Disease: A Cross Sectional Study

Background: Sickle cell disease (SCD) consists of a group of hemoglobinopathies in which individuals inherit hemoglobin variants derived from single point mutations. Asymmetric dimethylarginine (ADMA) contributes to limiting Nitric Oxide (NO) bioavailability in SCD. The aim of the present study was to assess the level of the Asymmetric Dimethyl Arginine in children with sickle cell. Methods: This cohort cross-sectional study was carried out on 60 children which were divided in to 3 equal groups. Group I: SCD children with sickle retinopathy. Group II: SCD children without retinopathy. Group III: healthy control children who were selected from the outpatient clinic. Results: There was a significant increase in ADMA level among participants withSCD. There was a positive significant correlation between ADMA level and family history as well as the incidence of hepatomegaly. There was no significant correlation between ADMA level and demographic and laboratory parameters except LDH. Conclusions: The level of ADMA is elevated in children with sickle cell anemia. High plasma ADMA level is a risk for hepatomegaly in children with sickle cell anemia.

Altered methylarginine levels after surgery in subjects with multinodular goiter

Objectives Thyroid disorders are important risk factor for cardiovascular diseases. Levels of methylarginines such as asymmetric dimethyl arginine (ADMA), L-monomethyl arginine (L-NMMA), symmetric dimethyl arginine (SDMA) are increase in cardiovascular diseases. Multinodular goiter (MNG) is the most common type of goiter in adults. To date, no study has been conducted to determine the levels of methylarginine in euthyroid MNG patients. Our aim in this study is to compare levels of methylarginines and related metabolites in the preoperative, postoperative MNG patients and controls. Methods Serum ADMA, SDMA, L-NMMA, homoarginine (hArg), arginine and citrulline concentrations were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results ADMA (p<0.001), L-NMMA (p=0.002), l-arginine (p=0.006) and citrulline (p<0.001) levels were statistically significantly higher in preop group than postop group. ADMA (p=0.003), L-NMMA (p=0.003) levels were statistically significantly higher and SDMA/ADMA (p<0.001), hArg/ADMA (p<0.001) levels were statistically significantly lower in preop group than control group. Conclusions The levels of methylarginines and related metabolites altered in the euthyroid MNG patients compared to the control group, and more importantly, there were significant differences between the preop and postop groups. Therefore, these metabolites can be useful in the diagnosis and prognosis of thyroid disorders, even if thyroid hormone levels are normal.

A Review of Specific Biomarkers of Chronic Renal Injury and Their Potential Application in Nonclinical Safety Assessment Studies

A host of novel renal biomarkers have been developed over the past few decades which have enhanced monitoring of renal disease and drug-induced kidney injury in both preclinical studies and in humans. Since chronic kidney disease (CKD) and acute kidney injury (AKI) share similar underlying mechanisms and the tubulointerstitial compartment has a functional role in the progression of CKD, urinary biomarkers of AKI may provide predictive information in chronic renal disease. Numerous studies have explored whether the recent AKI biomarkers could improve upon the standard clinical biomarkers, estimated glomerular filtration rate (eGFR), and urinary albumin to creatinine ratio, for predicting outcomes in CKD patients. This review is an introduction to alternative assays that can be utilized in chronic (>3 months duration) nonclinical safety studies to provide information on renal dysfunction and to demonstrate specific situations where these assays could be utilized in nonclinical drug development. Novel biomarkers such as symmetrical dimethyl arginine, dickkopf homolog 3, and cystatin C predict chronic renal injury in animals, act as surrogates for GFR, and may predict changes in GFR in patients over time, ultimately providing a bridge from preclinical to clinical renal monitoring.

Is there a relation between serum methylarginine levels and infertility?

Objectives Infertility is defined as the absence of pregnancy within the reproductive period despite regular sexual intercourse. Methylarginines are formed as a result of methylation of arginine residues in proteins and formed in three forms as asymmetric dimethyl arginine (ADMA), symmetrical dimethyl arginine (SDMA) and monomethylarginine (L-NMMA). So, here, we aimed to evaluate arginine and their derivatives levels in fertile and infertile individuals. Methods Present study were consist of 30 oligozoospermia patients (proven by spermiogram analysis) and 30 healthy individuals with normozoospermia group who were applied to the urology department. With blood samples taken from individuals, serum methylarginine and its derivatives levels were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Clinic data and demographic characteristics of individuals were also recorded at the same time. Results The serum ADMA level (0.38 ± 0.07) of the oligozoospermia group was found to be significantly higher than the normozoospermia group (0.35 ± 0.05) (p=0.046). A positive correlation were observed between ADMA and SDMA (r=0.686, p=0.000), HArg and SDMA (r=0.611, p=0.001), citrulline and L-NMMA (r=0.595, p=0.001) in patients with oligosospermia. The increase in SDMA, arginine and HArg levels and a decrease in L-NMMA and citrulline levels were not significant as statistically. Also, the ADMA level was found to be high in individuals with low sperm concentration. Conclusions Consequently, serum ADMA levels of individuals with oligozoospermia were statistically significantly higher than those with normozoospermia. As proposal, determination of ADMA levels may be a potential biomarker parameter in terms of early diagnosis of fertility and infertility.

Effect of Vitamin D supplementation on symmetric dimethyl arginine, asymmetric dimethyl arginine, homocysteine levels in rats being exposed to gamma radiation

Background: Radiation causes to damage on endothelial cells by increasing oxidative stress. Vitamin D is also a potent anti-oxidant that facilitates balanced mitochondrial activities, preventing oxidative stress-related protein oxidation, lipid peroxidation, and DNA damage. Aims and Objective: We aimed to investigate the potential effect of vitamin D supplementation on levels of Hcy (homocysteine), ADMA (Asymmetric Dimethyl Arginine), and SDMA (Symmetrical Dimethyl Arginine) which are admitted as endothelial dysfunction markers in rat models that are exposed to gamma radiation. Materials and Methods: Twentyfour female Wistar Albino rats were selected for the study. The mean weight of these rats were between 200 and 250 grams. Rats were fed with standard light (12 hours day light /12 hours dark), enough water (ad-libitum) at temperature (25ºC) for a total of 4 weeks. The rats were divided into 4 different groups and each group consisted of 6 rats. controlgroup (group I) did not receive any supplementation and not expose to gamma radiation), Group II was merely exposed to gamma radiation, Group III was exposed to gamma radiation and received vitamin D supplementation, and Group IV merely received vitamin D supplementation. Groups that are given vitamin D supplementation were fed by oral gavage at the same time and every day for one week. Finally, Group II and Group III were exposed to gammaradiation at the 8th day. After the completion of all processes, Vitamin D, ADMA, SDMA and Hcy levels were measured by HPLC (High-performance liquid chromatography) method. Results: When the results of Group II and Group III were compared with each other, we achieved merely statistical significance in vitamin D results (p=0.04) but did not other parameters (p>0.05). Conclusion: We observed that vitamin D supplementation did not any effect on SDMA, ADMA, and Hcy that accompany possible endothelial dysfunction after gamma radiation exposure.

LC–MS/MS quantification of asymmetric dimethyl arginine and symmetric dimethyl arginine in plasma using surrogate matrix and derivatization with fluorescamine

Aim: A novel LC–MS/MS method using a surrogate matrix and derivatization with fluorescamine was developed and validated for simultaneous quantification of asymmetric dimethyl arginine and symmetric dimethyl arginine. Methods & results: Asymmetric dimethyl arginine, symmetric dimethyl arginine and corresponding internal standards were extracted using protein precipitation and derivatization with fluorescamine followed by SPE. Derivatives were analyzed by turbo ion spray LC–MS/MS in the positive ion mode. Methodology was successfully transferred across multiple preclinical species and utilized in the support of several investigative studies. Conclusion: A new LC–MS/MS analytical methodology that utilizes a surrogate matrix and derivatization with fluorescamine was successfully developed and validated.