Substances In Plasma Research Articles

Oxidative and Nitrosative Stress in Stable Renal Transplant Recipients with Respect to the Immunosuppression Protocol - Differences or Similarities?

SummaryBackgroundThe aim of the study was to evaluate parameters of oxidative and nitrosative stress as well as antioxidative parameters in a group of renal transplant recipients with stable graft function and no clinical signs of cardiovascular disease. We also aimed to determine the correlations among these parameters and to evaluate potential differences in all the biomarkers with regard to the immunosuppression protocol.MethodsWe enrolled 57 renal transplant recipients and 31 controls who were age and sex matched with the renal transplant recipients. All of the patients included in this study had post-renal transplant surgery at least 12 months earlier and were on standard immunosuppressive therapy. In this study, we determined thiobarbituric acid-reactive substances in plasma and red blood cells and advanced oxidation protein products, nitrosative stress parameters (asymmetric and symmetric dimethylarginine – ADMA and SDMA), and antioxidative parameters (total SH groups and catalase activity).ResultsThe results of our study demonstrated that the levels of oxidative and nitrosative stress were significantly increased compared to the healthy population (p<0.01 except for plasma catalase activity p<0.05). Correlation analysis showed significant positive correlations between: ADMA and SDMA (p<0.01); ADMA and nitrates (p<0.05); SDMA and nitrates (p<0.05); between OS parameters in the experimental group; AOPP and SH groups (p<0.05) and TBARS in plasma and SH groups (p<0.01), SDMA and AOPP (p< 0.05); SDMA and TBARS in plasma (p<0.05); SDMA and SH groups (p<0.01); nitrates and SH groups (p<0.05).ConclusionThere was no significant difference in oxidative and nitrosative stress parameters with respect to the immunosuppressive protocol.

Reliability of perfluoroalkyl substances in plasma of 100 women in two consecutive pregnancies

The potential toxicity of background exposure to perfluoroalkyl substances (PFASs) is currently under active investigation. Such investigations typically rely on a single measure of PFAS concentration, yet the longer-term reliability of a single measure has not been well characterized, especially among reproductive-aged women. Our aim was to investigate the association between PFAS plasma concentrations of 100 women in two consecutive pregnancies and explore changes in plasma concentration related to reproductive factors. The women in our study were enrolled in the Norwegian Mother and Child Cohort Study (MoBa) from 2003 to 2009. About half of them breastfed exclusively for 6 months and the rest of the participants did not breastfeed between the two consecutive pregnancies (median time between pregnancies: 18 months). Maternal blood was collected at mid-pregnancy and plasma was analyzed for 10 PFASs. Statistical analyses were restricted to 6 PFASs that were quantifiable in more than 80% of the samples. We estimated the correlation between repeated PFAS measurements, the percentage change between pregnancies and the effect of several reproductive factors in multivariate linear regression models of PFAS concentrations in the second pregnancy. The Pearson correlation coefficient between repeated PFAS measurements was, for perfluorooctane sulfonate (PFOS), 0.80; perfluorooctanoate (PFOA), 0.50; perfluorohexane sulfonate (PFHxS), 0.74; perfluorononanoate (PFNA), 0.39; perfluoroundecanoate (PFUnDA), 0.71; and perfluorodecanoate (PFDA), 0.60. Adjustment for maternal age, delivery year, and time and breastfeeding between pregnancies did not substantially affect the observed correlations. We found 44–47% median reductions in the concentrations of PFOS, PFOA and PFHxS between pregnancies, while the change in concentrations between pregnancies was smaller and more variable for PFNA, PFUnDA and PFDA. The variation in plasma concentrations in the second pregnancy was mainly accounted for by the concentration in the first pregnancy; for PFOS, PFOA, and PFNA, breastfeeding also accounted for a substantial proportion. In conclusion, we found the reliability of PFAS measurements in maternal plasma to be moderate to high, and in these data, several factors, especially breastfeeding, were related to plasma concentrations.

Identification of 5-15 kDa substances in carp seminal plasma using mass spectrometry

The objective of this study was to detect substances of 5–15 kDa in carp seminal plasma using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and to compare mass spectrometry profiles between two common carp lines. Resolved were seminal plasma proteins using tris – tricine SDS – PAGE. Also found were 19 mass spectra peaks of carp seminal plasma. A few low-molecular mass proteins were identified, including parvalbumin, apolipoprotein, histone H4 and H2A, and one hypothetical protein. Mass spectrometry was not useful for molecular profiling of carp breeding lines, but are potentially useful for comparative studies of cyprinids.

산약이 흰쥐의 급성 위궤양에 의한 위장 장애에 미치는 효과

In order to verify the effects of Dioscorea Rhizoma on gastrointestinal damages, we investigated the protective role of the crude extracts on induced gastric ulceration in rats. Rats administered of Dioscorea Rhizoma extracts showed gradually decreased congestion and hemorrhage, but control group did not show any symptom in gastric tissue. Moreover, Dioscorea Rhizoma extract had a role in lowering gastrin and histamine levels in gastric ulcer rats, thereby inhibiting the gastric tissue damages. Excessive production of malondialdehyde shown in gastric ulcer rats was declined in all rats administered with Dioscorea Rhizoma extract as well as the levels of SOD and GPX surged by acute gastric ulcer. Also, the increased activity of CAT showed an effect in activation of antioxidant enzyme to normal state. All data suggest that Dioscorea Rhizoma extract was verified to be highly effective resource in improving the gastrointestinal function of rats by preventing from gastric tissue damage in acute gastric ulcer and restoring the activities of plasma substances and antioxidant enzymes.

Perfluoroalkyl substances detected in the world's southernmost marine mammal, the Weddell seal (Leptonychotes weddellii)

This study investigates concentrations of 18 perfluoroalkyl substances (PFAS) in blood plasma of adult lactating Weddell seals (Leptonychotes weddellii) (n = 10) from McMurdo Sound, Antarctica. Perfluoroundecanoic acid (PFUnDA) was detected in all samples at concentrations ranging from 0.08 to 0.23 ng/ml. Perfluorooctane sulfonate (PFOS), perfluorohexanoate (PFHxA) and perfluorotridecanoate (PFTriDA) were sporadically detected, while the remaining compounds were below the limit of detection. This is the first report of detectible concentrations of PFASs in an endemic Antarctic marine mammal species. We suggest that the pollutants have been subjected to long range atmospheric transportation and/or derive from a local source. A review of these and published data indicate that perfluoroalkyl carboxylates (PFCAs) dominate in biotic PFAS patterns in species feeding south of the Antarctic Circumpolar Current (ACC), whereas PFOS was the major PFAS detected in species feeding predominantly north of the current.

High throughput quantification of prohibited substances in plasma using thin film solid phase microextraction

Simple, fast and efficient sample preparation approaches that allow high-throughput isolation of various compounds from complex matrices are highly desired in bioanalysis. Particularly sought are methods that can, without sacrificing time, easily remove matrix interferences capable of inducing ionization suppression/enhancement, or causing detrimental effects in instrumental performance. In this work, an automated high-throughput sample preparation method using thin film solid phase microextraction (SPME) for the analysis of multiple prohibited substances in plasma is proposed. A biocompatible SPME extraction phase made of hydrophilic–lipophilic balance particles immobilized with polyacrylonitrile (PAN) demonstrated satisfactory extraction capabilities for 25 compounds of a wide range of polarities (logP from −2 to 6.8). Due to the well-known biocompatible characteristics of PAN-based SPME coatings, minimum sample handling was required. Experimental conditions for pre-conditioning, extraction, wash and desorption were carefully optimized for the proposed method. By taking full advantage of the 96 thin film handling capability of the automated system, a preparation time of approximately 1.5min per sample can be achieved. Satisfactory results in terms of absolute matrix effects were found for the majority of the studied analytes, given that 24 out of 25 compounds exhibited values in the range of 100 and 120%. The method was validated in terms of linearity (R2>0.99), inter and intra-day accuracy (85–130%) and precision (<20%) and limits of quantitation (0.25–10ngmL−1 for most compounds).

Proteome analysis of stratum corneum from atopic dermatitis patients by hybrid quadrupole-orbitrap mass spectrometer

Proteome analysis of stratum corneum from atopic dermatitis patients by hybrid quadrupole-orbitrap mass spectrometer

Contaminant levels in the world’s northernmost harbor seals (Phoca vitulina)

The world’s northernmost harbor seal (Phoca vitulina) population, which inhabits Svalbard, Norway, constitutes a genetically distinct population. The present study reports concentrations of 14 PCBs, 5 chlordanes, p,p′-DDT, p,p′-DDE, hexachlorobenzene (HCB), mirex, and, α-, β-and γ-hexachlorocyclohexane (HCH) in blubber, and pentachlorophenol, 4-OH-heptachlorostyrene, 10 OH-PCBs and 14 perfluoroalkyl substances in plasma of live-captured harbor seals from this population (4 males, 4 females, 4 juveniles), sampled in 2009–2010. Concentrations of PCB 153, p,p′-DDE, oxychlordane, α-HCH and mirex and perfluoroalkyl sulfonates in Svalbard harbor seals were considerably lower than harbor seal from more southerly populations, while concentrations of HCB, OH-PCBs and perfluoroalkyl carboxylates were similar for harbor seals from Svalbard and southern areas. Concentrations of PCBs and pesticides in the Svalbard harbor seals were 60–90% lower than levels determined a decade ago in this same population. Current concentrations of legacy POPs are not considered a health risk to the harbor seals from Svalbard.

Simultaneous determination of oxiracetam and its degraded substance in rat plasma by HPLC-MS/MS and its application to pharmacokinetic study after a single high-dose intravenous administration.

A simple, rapid and sensitive reversed-phase ultra-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed and validated for the simultaneous quantitative determination of oxiracetam and its degraded substance 4-hydroxy-2-oxo-1-pyrrolidine acetic acid (HOPAA) in rat plasma. After plasma samples were deproteinized with acetonitrile, the post-treatment samples were analyzed on a C18 column interfaced with a triple quadrupole tandem mass spectrometer in the positive electrospray ionization mode at a flow rate of 0.35ml/min. Piracetam was used as internal standard (IS). Multiple selected reaction monitoring was performed using the transitions m/z 159.00→141.94, 159.95→113.98 and 142.98→125.97 to quantify oxiracetam, HOPAA and IS, respectively. This method was validated over the concentration range of 25-2250μg/ml for oxiracetam (r(2)≥0.99) and 0.5-250μg/ml (r(2)≥0.99) for HOPAA. Intra-run and inter-run precision values of oxiracetam and HOPAA were less than 15% and accuracy was within 85-115% at all quality control levels. The average extraction recovery was 93.9% for oxiracetam and 95.6% for HOPAA, respectively. In conclusion, a simple, sensitive and specific HPLC-MS/MS method was successfully applied to the pharmacokinetic study in rats after an intravenous administration at a high dose of 2g/kg.

Development of a microchip Europium nanoparticle immunoassay for sensitive point-of-care HIV detection

Rapid, sensitive and specific diagnostic assays play an indispensable role in determination of HIV infection stages and evaluation of efficacy of antiretroviral therapy. Recently, our laboratory developed a sensitive Europium nanoparticle-based microtiter-plate immunoassay capable of detecting target analytes at subpicogram per milliliter levels without the use of catalytic enzymes and signal amplification processes. Encouraged by its sensitivity and simplicity, we continued to miniaturize this assay to a microchip platform for the purpose of converting the benchtop assay technique to a point-of-care test. It was found that detection capability of the microchip platform could be readily improved using Europium nanoparticle probes. We were able to routinely detect 5pg/mL (4.6 attomoles) of HIV-1 p24 antigen at a signal-to-blank ratio of 1.5, a sensitivity level reasonably close to that of microtiter-plate Europium nanoparticle assay. Meanwhile, use of the microchip platform effectively reduced sample/reagent consumption 4.5 fold and shortened total assay time 2 fold in comparison with microtiter plate assays. Complex matrix substance in plasma negatively affected the microchip assays and the effects could be minimized by diluting the samples before loading. With further improvements in sensitivity, reproducibility, usability, assay process simplification, and incorporation of portable time-resolved fluorescence reader, Europium nanoparticle immunoassay technology could be adapted to meet the challenges of point-of-care diagnosis of HIV or other health-threatening pathogens at bedside or in resource-limited settings.

Challenges of the glomerular filtration rate

The important physiologic measures in a variety of organ systems (think tidal volume for pulmonologists or ejection fraction for cardiologists) are routinely measured directly. In contrast, the most commonly used measure of kidney function, the glomerular filtration rate (GFR), is rarely ever measured outside of research settings. Instead, we rely upon the concentration of various plasma substances, which are cleared by the kidneys, as surrogates for GFR. Of these, creatinine is probably the most common.

Superoxide dismutase: a predicting factor for boar semen characteristics for short-term preservation.

Superoxide dismutase (SOD), total antioxidant capacity (TAC), and thiobarbituric acid reactive substances (TBARS) in seminal plasma were evaluated on the basis of receiver operating characteristics (ROC) analysis as predictors for distinguishing satisfactory from unsatisfactory boar semen samples after storage. SOD on day 0 correlated significantly with progressive motility (r = −0.686; P < 0.05) and viability (r = −0.513; P < 0.05) after storage; TBARS correlated only with motility (r = −0.480; P < 0.05). Semen samples that, after 3 days of storage, fulfilled all criteria for semen characteristics (viability > 85%, motility > 70%, progressive motility > 25%, and normal morphology > 50%) had significantly lower SOD levels on the day 0 than those with at least one criterion not fulfilled (P < 0.05) following storage. SOD levels of less than 1.05 U/mL predicted with 87.5% accuracy that fresh semen will suit the requirements for satisfactory semen characteristics after storage, while semen with SOD levels higher than 1.05 U/mL will not fulfill with 100% accuracy at least one semen characteristic after storage. These results support the proposal that SOD in fresh boar semen can be used as a predictor of semen quality after storage.

Disturbance of antioxidant protection and natural resistance factors in rats with different availabilities of trivalent chromium

The aim of this study was to examine the influence of trivalent chromium ions (Cr^{3+}) supplementation on antioxidant status and immune defense of rats. During the 30 days of the experiment, the male rats (n = 10 per group) were supplemented with CrCl_3, dissolved in distilled drinking water in doses of 0, 70, or 140 µg Cr^{3+}/dm^3. Next, the contents of hydroperoxides of lipids (HPL) and thiobarbituric acid reactive substances (TBARS) in plasma were determined, as well as the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and reduced glutathione (GSH) in erythrocytes. Lysozymic and bactericidal activities of blood serum were also determined. Results of the experiment indicated that 140 µg Cr^{3+}/dm^3 increased HPL concentration by 22.1%, while the dose of 70 µg Cr^{3+}/dm^3 decreased concentration of TBARS by 20.3% (P =< 0.05) in comparison with the control. Activity of SOD in rats supplied with both doses of Cr^{3+} significantly decreased, whereas activity of CAT, GPx, and GR significantly increased, similar to lysozymic and bactericidal activity. In general, the obtained results showed that a diet with chromium supplementation can strengthen the main mechanisms of lipid peroxidation defense by stimulation of enzyme activity of the antioxidant system and natural resistance factors.

Concordance between self-reported substance use and toxicology among HIV-infected and uninfected at risk youth

BackgroundSubstance use by youth living with HIV (YLWH) is a concern, given potential interactions with virus-associated immune suppression and adverse effects on risk behaviors, neurocognition, and adherence. Self-report substance use measures provide efficient cost-effective assessments. Analyses describe self-reported substance use among YLWH and examine agreement with toxicology assays. MethodsSeventy-eight youth age 18–24 years (87% male, 71% African–American) with behaviorally acquired HIV-1 infection and 55 uninfected youth completed the Alcohol, Smoking, and Substance Involvement Screening Test to assess drug use frequency, including tobacco, marijuana, cocaine, and alcohol, over the prior three months. Elisa-based toxicology assays were used to detect 27 substances in plasma. Chi-square tests compared substance use between YLWH and uninfected youth; Kappa statistics compared agreement between self-report and toxicology. ResultsYLWH reported marijuana (49%), tobacco (56%), and alcohol (87%) use, with 20%, 28% and 3% reporting daily use of each substance, respectively; other substance use was uncommon. Uninfected youth reported less tobacco use but otherwise similar substance use. All youth who reported daily use of marijuana or tobacco had positive plasma toxicology results, while concordance decreased with less frequent self-reported use. Among youth reporting no substance use, few tested positive (4% YLWH, 2% uninfected youth for cannabis; 8%YLWH for tobacco). ConclusionsYouth report high rates of marijuana, tobacco, and alcohol use. Concordance between self-report and toxicology for marijuana and tobacco use, particularly for daily users, supports self-report as a valid indicator of substance use in research studies of youth with or without HIV-1 infection.

Vitamin D Measurement in the Intensive Care Unit: Methodology, Clinical Relevance and Interpretation of a Random Value

Vitamin D deficiency, as measured by a random level of 25-hydroxyvitamin D is very prevalent in critically ill patients admitted to the ICU and is associated with adverse outcomes. Both 25(OH)vitamin D and 1α,25(OH)2D3 are difficult to analyse because of their lipophilic nature, affinity for VDBP and small concentrations. Also, the various tests used to estimate vitamin D levels show significant inter- and intra-assay variability, which significantly affect the veracity of the results obtained and confound their interpretation. The two main types of assays include those that directly estimate vitamin D levels (HPLC, LC-MS/MS) and competitive binding assays (RIA, EIA). The former methods require skilled operators, with prolonged assay times and increased cost, whereas the latter are cheaper and easy to perform, but with decreased accuracy. The direct assays are not affected by lipophilic substances in plasma and heterophile antibodies, but may overestimate vitamin D levels by measuring the 3-epimers. These problems can be eliminated by adequate standardization of the test using SRMs provided by NIST, as well as participating in proficiency schemes like DEQAS. It is therefore important to consider the test employed as well as laboratory quality control, while interpreting vitamin D results. A single random measurement may not be reflective of the vitamin D status in ICU patients because of changes with fluid administration, and intra-day variation in 25-hydroxyvitamin D levels. 1α,25(OH)2D3 may behave differently to 25-hydroxyvitamin D, both in plasma and at tissue level, in inflammatory states. Measurement of tissue 1α,25(OH)2D3 levels may provide the true estimate of vitamin D activity.

Discordant CD34+ cell results in peripheral blood and hematopoietic progenitor cell–apheresis product: implications for clinical decisions and impact on patient treatment

A 50-year-old male with T-cell lymphoma presented for autologous peripheral blood stem cell transplantation. After granulocyte-colony-stimulating factor (G-CSF) mobilization, his peripheral blood CD34+ cell count was 166 × 10(6) /L on the day before collection, which predicted a high yield of CD34+ cells in the apheresis product. The first two collections had yields much lower than expected, triggering an investigation and changes to the apheresis collection methods since mobilization appeared adequate from the peripheral CD34+ values. Changes to the apheresis collection variables and instrumentation did not improve the yields in the next three collections. The laboratory investigation demonstrated that there was an interfering substance in the patient's plasma that was causing falsely high peripheral blood CD34+ cell values and that the low CD34+ cell yields in the collections were consistent with the actual peripheral blood CD34+ cell value. Based on this finding and after discussion with the clinical service, the patient then received plerixafor to increase the number of circulating CD34+ cells before Collections 6 and 7. The patient went on to achieve the target CD34+ cell dose and subsequently underwent a successful autologous transplant with full hematopoietic engraftment. This case demonstrates the importance of timely and critical review of laboratory results in the context of the specific patient. This case exemplifies how diligent review of laboratory results and open communication among the various teams can positively affect patient outcomes.

Antioxidant Action of Solid Preparation of Xingnaojing in SHRSP

We investigated the antioxidant action of a solid preparation of Xingnaojing (XNJ) and ascorbic acid (AA) in stroke-prone spontaneously hypertensive rats (SHRSP). The total antioxidant states in the plasma, systolic blood pressure, and heart rate were measured every 2 weeks, and lipid peroxidation, expressed as thiobarbituric acid-reactive substances in plasma, was measured in the 6th week. The results showed that AA and XNJ significantly increased the total antioxidant status in plasma and reduced malondialdehyde in the plasma. These data suggest that during 6-week administration, XNJ has antioxidant action on SHRSP, which may relate to its generalized inhibition of lipid peroxidation and promotion of the total antioxidant state. These results demonstrated that orally treated XNJ has an antioxidant effect on SHRSP plasma.

Recovery of kidney function following delayed use of theralite™ dialyzer in a patient with myeloma cast nephropathy

We report the case of a 60- year- old man who presented with newly diagnosed multiple myeloma complicated by biopsy-proven acute cast nephropathy, requiring hemodialysis, plasmapheresis and chemotherapy. After remaining dialysis dependent for 5 weeks, a high cut-off (HCO) dialyzer, intended to use for the removal of plasma substances with a molecular weight of up to 45 kDa such as free light chains, was introduced to his outpatient 4-hour hemodialysis regimen with an increase in treatment frequency to 4 sessions per week. Following 6 weeks of dialysis with the HCO dialyzer, serum levels of free κ light chains declined by more than 75%. Concurrently, he recovered kidney function and discontinued dialysis. He subsequently received a successful autologous stem-cell transplant. We discuss the potential merit of using the HCO dialyzer late in the course of the care of patients with myeloma cast nephropathy who are dialysis dependent.

Role of Fibrinogen in Traumatic Brain Injury

Elevated level of fibrinogen (Fg) ‐ hyperfibrinogenemia (HFg) exacerbates circulatory complications during inflammatory diseases such as stroke, hypertension, traumatic brain injury (TBI). We already showed that HFg alters vascular reactivity and compromises endothelial cell layer integrity causing a leakage of plasma substances into the interstitium. We tested the hypothesis that TBI increases Fg deposition and cerebrovascular permeability in injury penumbra through activation of matrix metalloproteinase‐ 9 (MMP‐9).Permeability of pial venules and Fg deposition in injury penumbra formed after a mild cortical contusion injury (CCI) were studied in wild type (WT, C57BL/6J) and MMP‐9 gene knockout (MMP9−/−) mice. Fg deposition and formation of caveolae, examined by the extent of co‐localization of caveolin‐1 and plasmalemma vesicle‐associate protein‐1 were assessed in brain cryo‐sections. In each group, BSA leakage, caveolae formation, and Fg deposition were increased after CCI compared to those in respective sham‐operated mice. However, they were greater in WT than in MMP9−/− mice.These data suggest that blood level of Fg is elevated after TBI and its increased deposition intensifies cerebrovascular protein leakage mainly through caveolar transcytosis via activation of MMP‐9. The results of our study point to a new therapeutic targets that can be used to assist the post‐TBI healing process.

Supplementation of a grape seed and grape marc meal extract decreases activities of the oxidative stress-responsive transcription factors NF-κB and Nrf2 in the duodenal mucosa of pigs

BackgroundIn pigs, enteric infections and the development of gut disorders such as diarrhoea are commonly observed, particularly after weaning. The present study investigated the hypothesis that feeding a grape seed and grape marc extract (GSGME) as a dietary supplement has the potential to suppress the inflammatory process in the small intestine of pigs by modulating the activities of NF-κB and Nrf2 due to its high content of flavonoids.MethodsTwenty-four crossbred, 6 weeks old pigs were randomly assigned to 2 groups of 12 animals each and fed nutritionally adequate diets without or with 1% GSGME for 4 weeks.ResultsPigs administered GSGME had a lower transactivation of NF-κB and Nrf2 and a lower expression of various target genes of these transcription factors in the duodenal mucosa than control pigs (P < 0.05). Concentrations of α-tocopherol and thiobarbituric acid reactive substances (TBARS) in liver and plasma and total antioxidant capacity of plasma and relative mRNA abundances of NF-κB and Nrf2 target genes in the liver did not differ between the two groups. However, the ratio of villus height:crypt depth and the gain:feed ratio was higher in the pigs fed GSGME than in control pigs (P < 0.05).ConclusionsThis study shows that dietary supplementation of a polyphenol rich GSGME suppresses the activity of NF-κB in the duodenal mucosa of pigs and thus might provide a useful dietary strategy to inhibit inflammation in the gut frequently occurring in pigs. Feeding GSGME did not influence vitamin E status and the antioxidant system of the pigs but improved the gain:feed ratio. In overall, the study suggests that polyphenol-rich plant extracts such GSGME could be useful feed supplements in pig nutrition, in order to maintain animal health and improve performance.