Physiological and pathological changes in the redox state of human serum albumin critically influence its binding properties

Implications of chronic moderate protein-deficiency malnutrition on doxorubicin pharmacokinetics and cardiotoxicity in early post-weaning stage

BACKGROUND

Malnutrition is a common problem in developing countries, and the impact of severe malnutrition on optimal treatment outcomes of chemotherapy in pediatric cancer patients is well documented. However, despite being a more prevalent and distinct entity, moderate malnutrition is until now unexplored for its effects on treatment outcomes.

AIMS

In this study we aimed to investigate the molecular basis of altered pharmacokinetics and cardiotoxicity of doxorubicin observed in early-life chronic moderate protein deficiency malnutrition.

MATERIALS AND METHODS

We developed an animal model of early-life moderate protein-deficiency malnutrition and validated it using clinical samples. This model was used to study pharmacokinetic and toxicity changes and was further utilized to study the molecular changes in liver and heart to get mechanistic insights.

KEY FINDINGS

Here we show that moderate protein-deficiency malnutrition in weanling rats causes changes in drug disposition in the liver by modification of hepatic ABCC3 and MRP2 transporters through the TNFα signalling axis. Furthermore, malnourished rats in repeat-dose doxorubicin toxicity study showed higher toxicity and mortality. A higher accumulation of doxorubicin in the heart was observed which was associated with alterations in cardiac metabolic pathways and increased cardiotoxicity.

SIGNIFICANCE

Our findings indicate that moderate malnutrition causes increased susceptibility towards toxic side effects of chemotherapy. These results may necessitate further investigations and new guidelines on the dosing of chemotherapy in moderately malnourished pediatric cancer patients.

Is serum albumin a pivotal biomarker in anticipating acute pancreatitis outcomes?

This study aimed to assess the significance of serum albumin levels within 24 h of patient admission in correlation with the incidence of outcomes and mortality in patients diagnosed with acute pancreatitis. A retrospective study was conducted over a 5-year period, from January 2018 to December 2023, at the Mohammed VI University Hospital in Oujda, Morocco. The study included 371 patients diagnosed with acute pancreatitis. Hypoalbuminemia (≤ 30 g/L) was observed in 124 patients (33.4% of cases), and these patients had a higher mean age compared to those with normal albumin levels (P = 0.003). Hypoalbuminemia was significantly associated with persistent Systemic Inflammatory Response Syndrome (SIRS) (70.8% vs. 29.2%, P = 0.000), a higher BISAP score (66.7% vs. 33.3%, P = 0.000), and a higher CTSI score (51.7% vs. 48.3%, P = 0.000). Hypoalbuminemia was also associated with the presence of pleural effusion (P = 0.000). The mortality in the sample was 4.6%, and it was significantly associated with hypoalbuminemia (76.5%, P = 0.000). In conclusion, serum albumin levels within 24 h of patient admission appear to be a significant prognostic biomarker in acute pancreatitis, particularly in anticipating persistent organ failure and mortality.

Pitfalls in the diagnosis and management of acid-base disorders in humans: a laboratory medicine perspective

Diagnostic errors affect patient management, and as blood gas analysis is mainly performed without the laboratory, users must be aware of the potential pitfalls. The aim was to provide a summary of common issues users should be aware of.A narrative review was performed using online databases such as PubMed, Google Scholar and reference lists of identified papers. Language was limited to English.Errors can be pre-analytical, analytical or post-analytical. Samples should be analysed within 15 min and kept at room temperature and taken at least 15-30 min after changes to inspired oxygen and ventilator settings, for accurate oxygen measurement. Plastic syringes are more oxygen permeable if chilled. Currently, analysers run arterial, venous, capillary and intraosseous samples, but variations in reference intervals may not be appreciated or reported. Analytical issues can arise from interference secondary to drugs, such as spurious hyperchloraemia with salicylate and hyperlactataemia with ethylene glycol, or pathology, such as spurious hypoxaemia with leucocytosis and alkalosis in hypoalbuminaemia. Interpretation is complicated by result adjustment, for example, temperature (alpha-stat adjustment may overestimate partial pressure of carbon dioxide (pCO2) in hypothermia, for example), and inappropriate reference intervals, for example, in pregnancy bicarbonate, and pCO2 ranges should be lowered.Lack of appreciation for patient-specific and circumstance-specific reference intervals, including extremes of age and altitude, and transformation of measurements to standard conditions can lead to inappropriate assumptions. It is vitally important for users to optimise specimen collection, appreciate the analytical methods and understand when reference intervals are applicable to their specimen type, clinical question or patient.

Elevated Fibrinogen-to-Albumin Ratio Correlates with Incident Stroke in Cerebral Small Vessel Disease

Purpose

We aimed to explore the association between fibrinogen-to-albumin ratio (FAR) and the risk of incident stroke (IS) in a cohort of cerebral small vessel disease (CSVD) patients.

Patients and Methods

Participants were screened from a prospective CSVD database. Clinical data, hematologic measures and imaging findings were collected. The primary outcome was IS during follow-up, with a secondary outcome of composite vascular events (CVE) including IS, myocardial infarction (MI), and vascular deaths. Univariate and multivariate COX proportional risk models, along with competing risk models, were employed to identify factors associated with outcomes. Restricted cubic spline (RCS) and subgroup analyses were conducted to assess the association between FAR and the risk of IS and CVE in CSVD patients.

Results

In the final analysis of 682 CSVD patients over a median observation period of 34.0 [24.0-53.0] months, there were 33 cases of IS (4.84%, 1.55/100 person-years), 4 incidents of MI (0.59%, 0.19/100 person-years), 15 non-vascular deaths (2.20%, 0.70/100 person-years), and 37 occurrences of CVE (5.43%, 1.74/100 person-years). Multivariate Cox regression analysis revealed a significant positive correlation between elevated FAR and both IS (HR 1.146; 95% CI 1.043-1.259; P=0.004) and CVE (HR 1.156; 95% CI 1.063-1.257; P=0.001) in CSVD patients. Multivariate competing risk model showed the similar results (IS: HR 1.16; 95% CI 1.06-1.27; P=0.001, CVE: HR 1.15; 95% CI 1.05-1.26; P=0.003). RCS analysis indicated a linear relationship between FAR and the risks of both IS (P for non-linearity =0.7016) and CVE (P for non-linearity =0.6475), with an optimal cutoff value of 8.69, particularly in individuals over 60 years of age.

Conclusion

Elevated FAR demonstrated an independent and linear association with IS and the development of CVE in CSVD patients.

Albumin levels in malaria patients: a systematic review and meta-analysis of their association with disease severity

Albumin, a key protein in human blood plasma, has been linked to various health conditions. However, its association with malaria, particularly in assessing disease severity, remains inadequately understood. This comprehensive systematic review and meta-analysis aimed to elucidate the relationship between albumin levels and malaria severity. A comprehensive literature search was conducted across multiple databases, including Embase, Scopus, PubMed, MEDLINE, Ovid, and Google Scholar, to identify studies examining albumin levels in malaria patients. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Data were pooled using a random-effects model, and heterogeneity was assessed using I2 statistics. Subgroup and meta-regression analyses were performed based on publication year, study location, and Plasmodium species. A total of 37 studies were included in this review. The thematic synthesis indicated that albumin levels in malaria patients varied significantly based on geographical location. A meta-analysis of 28 studies found that albumin levels were significantly lower in malaria patients compared with non-malarial controls (P < 0.001, standardized mean differences [SMD] = -2.23, 95% CI - 3.25 to - 1.20, I2: 98%, random effects model, 28 studies). Additionally, subgroup analysis revealed variations in albumin levels based on geographical location and Plasmodium species. Regarding the association with disease severity, thematic synthesis showed that severe malaria cases generally had decreased albumin levels across various regions. However, one Brazilian study reported higher albumin levels in severe cases. A separate meta-analysis of five studies found significantly lower albumin levels in patients experiencing severe malaria relative to those with less severe forms of the disease (P < 0.001, SMD = -0.66, 95% CI - 1.07 to - 0.25), I2: 73%, random effects model, 5 studies). This study underscores the clinical significance of albumin as a potential biomarker for Plasmodium infection and the severity of malaria. The findings suggest that albumin level monitoring could be crucial in managing malaria patients, especially in assessing disease severity and tailoring treatment approaches. Additional studies are required to investigate the underlying mechanisms driving these associations and validate the clinical utility of albumin levels in malaria patient management.

High-concentration bovine serum albumin enhances fertilization ability of cold-stored rat sperm

Cold transport of the cauda epididymides is a useful technique for shipping laboratory rat sperm. Cold transport of rat sperm avoids potential risks of microbiological infection, animal escape or death, and animal welfare issues. Previously, we reported that a cold-storage solution containing dimethyl sulfoxide and quercetin maintained the fertility of cold-stored rat sperm. However, cold-stored rat sperm exhibited a decreased fertilization rate after 24-h storage. To recover the fertility of cold-stored sperm, we focused on the effects of bovine serum albumin (BSA), a cholesterol acceptor that induces sperm capacitation. We sought to determine the optimal concentration of BSA in fertilization medium based on the fertility of cold-stored rat sperm. High concentrations of BSA (40 mg/ml) enhanced the fertilization rate of cold-stored rat sperm and maintained sperm fertility for 144 h. Embryos derived from cold-stored and BSA-treated sperm normally developed into pups after embryo transfer. In summary, high BSA concentrations enhanced the fertility of cold-stored rat sperm and prolonged the storage period to 144 h, thereby expanding the transportable region for genetically engineered rats.

Unlocking Potential: Low Bovine Serum Albumin Enhances the Chondrogenicity of Human Adipose-Derived Stromal Cells in Pellet Cultures

Bovine serum albumin (BSA) plays a crucial role in cell culture media, influencing cellular processes such as proliferation and differentiation. Although it is commonly included in chondrogenic differentiation media, its specific function remains unclear. This study explores the effect of different BSA concentrations on the chondrogenic differentiation of human adipose-derived stromal/stem cells (hASCs). hASC pellets from six donors were cultured under chondrogenic conditions with three BSA concentrations. Surprisingly, a lower BSA concentration led to enhanced chondrogenesis. The degree of this effect was donor-dependent, classifying them into two groups: (1) high responders, forming at least 35% larger, differentiated pellets with low BSA in comparison to high BSA; (2) low responders, which benefitted only slightly from low BSA doses with a decrease in pellet size and marginal differentiation, indicative of low intrinsic differentiation potential. In all cases, increased chondrogenesis was accompanied by hypertrophy under low BSA concentrations. To the best of our knowledge, this is the first study showing improved chondrogenicity and the tendency for hypertrophy with low BSA concentration compared to standard levels. Once the tendency for hypertrophy is understood, the determination of BSA concentration might be used to tune hASC chondrogenic or osteogenic differentiation.

Effect of albumin infusion on oxidative albumin modification and albumin binding capacity in chronic liver failure

Oxidative albumin modification and impaired albumin binding function have been described both in chronic liver failure and for therapeutic albumin solutions. The aim of the present study was to evaluate the effect of albumin infusion on redox state and binding function of circulating albumin. We studied 20 patients with cirrhosis who routinely received albumin infusions for prevention of post-paracentesis circulatory dysfunction or treatment of hepatorenal syndrome. We measured albumin fractions by redox state of cysteine-34 and albumin binding properties using dansylsarcosine as site II ligand. Therapeutic albumin solutions showed high contents of human nonmercaptalbumin-1 and human nonmercaptalbumin-2, exceeding the respective values in our patients with decompensated cirrhosis. An initial protocol for the first nine patients sampled at baseline, 24 h and 48 h after albumin infusion revealed no significant changes of oxidized albumin species or albumin binding properties. However, a modified protocol for the remaining 11 patients sampled at baseline, <1 h after and 24 h after albumin infusion revealed short-lived changes of oxidized albumin species while no changes in albumin binding properties were observed. In conclusion, therapeutic albumin infusion transiently changed albumin redox state but did not improve binding function of circulating albumin in chronic liver failure.

Albumin, an interesting and functionally diverse protein, varies from 'native' to 'effective' (Review)

Human serum albumins (HSAs) are synthesized in the liver and are the most abundant proteins in plasma of healthy human. They play an important role in the pathophysiological processes of the liver and even the whole organism. Previous studies have mainly focused on the regulation of HSAs' expression. However, with the progress of research in recent years, it has been found that the content of circulating albumin cannot fully reflect the biological function of albumin itself. Given the aforementioned fact, the concept of serum 'effective albumin concentration' has been proposed. It refers to the content of albumin that is structurally and functionally intact. Alterations in the molecular structure and function of albumin have been reported in a variety of diseases, including liver disease. Moreover, these changes have been verified to affect the progression of oxidative stress‑related diseases. However, the link between albumin structure and function has not been fully elaborated, and the mechanisms by which different forms of albumin affect disease also need to be further investigated. In this context, the present review mainly expounded the biological characteristics and functions of albumin, summarized the different types of post‑translational modification of albumin, and discussed their functional changes and possible mechanisms in non‑alcoholic fatty liver disease, alcoholic hepatitis, viral hepatitis and different stages of cirrhosis. This will help to improve understanding of the role of albumin in disease development and provide a more comprehensive physiological basis for it in disease treatment.

Albumin Redox Modifications Promote Cell Calcification Reflecting the Impact of Oxidative Status on Aortic Valve Disease and Atherosclerosis

Calcific aortic valve disease (CAVD) and coronary artery disease (CAD) are related cardiovascular diseases in which common mechanisms lead to tissue calcification. Oxidative stress plays a key role in these diseases and there is also evidence that the redox state of serum albumin exerts a significant influence on these conditions. To further explore this issue, we used multimarker scores (OxyScore and AntioxyScore) to assess the global oxidative status in patients with CAVD, with and without CAD, also evaluating their plasma thiol levels. In addition, valvular interstitial cells were treated with reduced, oxidized, and native albumin to study how this protein and its modifications affect cell calcification. The differences we found suggest that oxidative status is distinct in CAVD and CAD, with differences in redox markers and thiol levels. Importantly, the in vitro interstitial cell model revealed that modified albumin affects cell calcification, accelerating this process. Hence, we show here the importance of the redox system in the development of CAVD, emphasizing the relevance of multimarker scores, while also offering evidence of how the redox state of albumin influences vascular calcification. These data highlight the relevance of understanding the overall redox processes involved in these diseases, opening the door to new studies on antioxidants as potential therapies for these patients.

Serum Albumin for Short-Term Poor Prognosis in Patients With Acute Pulmonary Embolism: A Clinical Study Based on a Database

The relationship between serum albumin (ALB) and short-term prognosis in patients with acute pulmonary embolism (APE) remains unclear. We investigated the predictive value of ALB for short-term prognosis in APE patients using our hospital pulmonary embolism (PE) database (384 patients consecutively collected). Logistic regression analysis and nomograms were applied to construct the predictive model, and validation was assessed. A total of 340 APE patients were included, with a 30-day all-cause mortality rate of 8.5%. The incidence of hypoalbuminemia was 15.9%. The odds ratio (OR) for short-term mortality in patients with high ALB was 0.89 (0.886, 95% CI: 0.812-0.967). Additionally, we created a nomogram for individualized mortality risk prediction. Receiver operating characteristic (ROC) curve analysis showed that the diagnostic area under the curve (AUC) of ALB was 0.758 (95% CI 0.683-0.833), and the best cut-off value was 33.85 g/L. Optimal simplified Pulmonary Embolism Severity Index (sPESI) (ALB combined sPESI) AUC was 0.835 (95% CI 0.775-0.896). Baseline hypoalbuminemia may be an independent prognostic indicator of short-term mortality in patients with APE.

Association between fibrinogen-to-albumin ratio and functional prognosis of 3 months in patients with acute ischemic stroke after intravenous thrombolysis

BACKGROUND

The presence of high fibrinogen and low albumin levels in serum is associated with a negative prognosis in acute ischemic stroke (AIS). Fibrinogen-to-albumin ratio (FAR), a new inflammatory biomarker, may provide better prognostic insights in patients with AIS than separate evaluation of fibrinogen or albumin. The objective of this investigation is to examine the correlation between FAR and 3-month functional prognosis after intravenous thrombolysis (IVT) in AIS patients.

METHODS

The retrospective study recruited AIS patients who received IVT from June 2014 to December 2021. The 3-month functional prognosis was assessed using the Modified Rankin Scale (mRS). A mRS score of ≤2 indicated a good outcome, whereas a mRS score of >2 suggested a poor outcome.

RESULTS

A total of 591 AIS patients who underwent IVT were included and 147 patients (24.9 %) had a poor outcome. Among the 102 pairs of patients after propensity score matching, there was a significant association between FAR and 3-month prognosis (adjusted OR, 1.19; 95% CI, 1.03-1.38; p = .020). The optimal FAR cutoff value was found to be 7.57, and even after stratifying patients based on this value, we still observed a significant correlation between high FAR level and poor outcome (adjusted OR, 2.08; 95% CI, 1.28-3.40; p = .003).

CONCLUSIONS

FAR may serve as a prospective biomarker of predicting 3-month prognosis in AIS patients after IVT.

Evaluation of the dynamic thiol/disulfide homeostasis in patients with chronic venous insufficiency

OBJECTIVE

There is no study in the literature evaluating the dynamic thiol/disulfide homeostasis in patients with chronic venous insufficiency. Thus, we designed this study to evaluate the dynamic thiol/disulfide homeostasis as a novel indicator of oxidative stress in patients with chronic venous insufficiency.

METHODS

This was a prospective case-control study performed at the department of cardiovascular surgery of a tertiary referral hospital in Turkey. A total of 80 (CEAP C3-C6) patients with lower extremity chronic venous insufficiency (as the study group) and 80 healthy subjects (as the control group) were enrolled to the study. The participants' basic demographic and clinical characteristics as well as serum levels of some laboratory parameters including albumin, ferroxidase, myeloperoxidase, native thiol, total thiol, disulphide, native thiol/total thiol, disulphide/native thiol, and disulphide/total thiol were determined, and then compared between the groups.

RESULTS

In terms of basic demographic and clinical characteristics, both groups were statistically similar, and there were no significant differences between the groups. When the laboratory parameters were considered, serum ferroxidase and myeloperoxidase levels were detected to be significantly higher, whereas albumin, native thiol, total thiol, and disulphide levels were detected to be significantly lower in the study group than in the control group.

CONCLUSIONS

Dynamic thiol/disulphide homeostasis could be considered as an indicator reflecting the oxidative stress status in patients with chronic venous insufficiency.

Association of Ischemia-Modified Albumin (IMA) in Saliva, Serum, and Urine with Diagnosis of Chronic Kidney Disease (CKD) in Children: A Case-Control Study

BACKGROUND Ischemia-modified albumin (IMA) is a secreted biomarker for ischemic oxidative stress. This case-control study aimed to evaluate the association of ischemia-modified albumin (IMA) in saliva, serum, and urine with diagnosis of chronic kidney disease (CKD) in 24 children. MATERIAL AND METHODS The study involved 24 children with CKD. CKD was defined according to the Kidney Disease Improving Global Outcomes (KDIGO) diagnostic criteria. The control group consisted of 24 healthy children who were matched for age and gender to the experimental group. The concentration of IMA was determined by the colorimetric method in non-stimulated whole saliva (NWS), stimulated whole saliva (SWS), serum, and urine of children with CKD. The Mann-Whitney U test was used for inter-group comparisons. RESULTS IMA levels were significantly higher in NWS (P=0.0082) and SWS (P=0.0014) of children with CKD than in the control group. The concentration of IMA in NWS was correlated with standard indicators of kidney function, including the estimated glomerular filtration rate (r=-0.798, P≤0.0001), stage of CKD (r=0.814, P≤0.0001), and serum creatinine (r=0.711, P≤0.0001) and urea levels (r=0.738, P≤0.0001). CONCLUSIONS Salivary IMA concentration depends on renal function in children. Salivary IMA discriminates children with end-stage kidney disease from children with mild and moderate CKD and healthy children with high sensitivity and specificity. Further research is required, including assessment of the diagnostic usefulness and validation of the biomarker in a clinical diagnostic study.

Albumin Retains Its Transport Function after Interaction with Cerium Dioxide Nanoparticles

The interaction of inorganic nanomaterials with biological fluids containing proteins can lead not only to the formation of a protein corona and thereby to a change in the biological activity of nanoparticles but also to a significant effect on the structural and functional properties of the biomolecules themselves. This work studied the interaction of nanoscale CeO2, the most versatile nanozyme, with human serum albumin (HSA). Fourier transform infrared spectroscopy, MALDI-TOF mass spectrometry, UV-vis spectroscopy, and fluorescence spectroscopy confirmed the formation of HSA-CeO2 nanoparticle conjugates. Changes in protein conformation, which depend on the concentration of both citrate-stabilized CeO2 nanoparticles and pristine CeO2 nanoparticles, did not affect albumin drug-binding sites and, accordingly, did not impair the HSA transport function. The results obtained shed light on the biological consequences of the CeO2 nanoparticles' entrance into the body, which should be taken into account when engineering nanobiomaterials to increase their efficiency and reduce the side effects.

Potential effects of spirulina and date palm pollens on zinc oxide nanoparticles -induced hepatoxicity, oxidative stress, and inflammation in male albino rats

INTRODUCTION

The application of Zinc oxide nanoparticles (ZnO NPs) is substantially growing in industrial products. Therefore, humans are increasingly exposed to ZnO NPs daily due to their extensive range of applications, raising worries about their possible toxicity.

AIM

In this study, the ameliorative effects of raw Phoenix dactylifera L. (date palm) pollens (DPP) and Spirulina platensis (SP) independently against ZnO NPS-induced hepatoxicity in male albino rats were examined.

METHODS

Six groups (6/group) of adult male albino rats received oral treatment using distilled water (control), SP (1000 mg/kg b. wt.), DPP (100 mg/kg b. wt.), ZnO NPs (100 mg/kg b. wt.), ZnO NPs +SP, and ZnO NPs + DPP respectively for 15 days.

RESULTS

The results of the biochemical investigation indicated that the administration of ZnO NPs substantially upregulated (p < 0.05) transaminases, alkaline phosphatase, and bilirubin serum levels. Malondialdehyde and pro-inflammatory cytokine serum levels were also elevated after ZnO NPs administration. Simultaneously, the downregulated catalase and glutathione peroxidase serum activities were significantly suppressed in ZnO NPs treated rats. Moreover, exposure to ZnO NPs induced liver histopathological alterations. The administration of SP and DPP ameliorated the aforementioned effects caused by ZnO NPs. This result can be attributable to the downregulation of hepatic transaminases, alkaline phosphatase, and bilirubin in the serum and the antioxidation system's equilibration, thus alleviating the accumulation of reactive oxygen species.

CONCLUSION

SP and DPP are natural antioxidants with the potential to eliminate inflammation as well as oxidative damage caused by ZnO NPs in hepatic tissue.

Albumin Thiolation and Oxidative Stress Status in Patients with Aortic Valve Stenosis

Recent evidence indicates that reactive oxygen species play an important causative role in the onset and progression of valvular diseases. Here, we analyzed the oxidative modifications of albumin (HSA) occurring on Cysteine 34 and the antioxidant capacity of the serum in 44 patients with severe aortic stenosis (36 patients underwent aortic valve replacement and 8 underwent a second aortic valve substitution due to a degenerated bioprosthetic valve), and in 10 healthy donors (controls). Before surgical intervention, patients showed an increase in the oxidized form of albumin (HSA-Cys), a decrease in the native reduced form (HSA-SH), and a significant reduction in serum free sulfhydryl groups and in the total serum antioxidant activity. Patients undergoing a second valve replacement showed levels of HSA-Cys, free sulfhydryl groups, and total antioxidant activity similar to those of controls. In vitro incubation of whole blood with aspirin (ASA) significantly increased the free sulfhydryl groups, suggesting that the in vivo treatment with ASA may contribute to reducing oxidative stress. We also found that N-acetylcysteine and its amide derivative were able to regenerate HSA-SH. In conclusion, the systemic oxidative stress reflected by high levels of HSA-Cys is increased in patients with aortic valve stenosis. Thiol-disulfide breaking agents regenerate HSA-SH, thus paving the way to the use these compounds to mitigate the oxidative stress occurring in the disease.

Unraveling the versatility of human serum albumin - A comprehensive review of its biological significance and therapeutic potential

Human serum albumin (HSA) is a multi-domain macromolecule with diverse ligand binding capability because of its ability to allow allosteric modulation despite being a monomeric protein. Physiologically, HSA act as the primary carrier for various exogenous and endogenous compounds and fatty acids, and alter the pharmacokinetic properties of several drugs. It has antioxidant properties and is utilized therapeutically to improve the drug delivery of pharmacological agents for the treatment of several disorders. The flexibility of albumin in holding various types of drugs coupled with a variety of modifications makes this protein a versatile drug carrier with incalculable potential in therapeutics. This review provides a brief outline of the different structural properties of HSA, and its various binding sites, moreover, an overview of the genetic, biomedical, and allosteric modulation of drugs and drug delivery aspects of HSA is also included, which may be helpful in guiding advanced clinical applications and further research on the therapeutic potential of this extraordinary protein.

Highly oxidized albumin is cleared by liver sinusoidal endothelial cells via the receptors stabilin-1 and -2

Oxidized albumin (oxHSA) is elevated in several pathological conditions, such as decompensated cirrhosis, acute on chronic liver failure and liver mediated renal failure. Patient derived oxidized albumin was previously shown to be an inflammatory mediator, and in normal serum levels of oxHSA are low. The removal from circulation of oxidized albumins is therefore likely required for maintenance of homeostasis. Liver sinusoidal endothelial cells (LSEC) are prominent scavenger cells specialized in removal of macromolecular waste. Given that oxidized albumin is mainly cleared by the liver, we hypothesized the LSEC are the site of uptake in the liver. In vivo oxHSA was cleared rapidly by the liver and distributed to mainly the LSEC. In in vitro studies LSEC endocytosed oxHSA much more than other cell populations isolated from the liver. Furthermore, it was shown that the uptake was mediated by the stabilins, by affinity chromatography-mass spectrometry, inhibiting uptake in LSEC with other stabilin ligands and showing uptake in HEK cells overexpressing stabilin-1 or -2. oxHSA also inhibited the uptake of other stabilin ligands, and a 2-h challenge with 100 µg/mL oxHSA reduced LSEC endocytosis by 60% up to 12 h after. Thus the LSEC and their stabilins mediate clearance of highly oxidized albumin, and oxidized albumin can downregulate their endocytic capacity in turn.

In Situ Bioconjugation of a Maleimide-Functionalized Ruthenium-Based Photosensitizer to Albumin for Photodynamic Therapy

Maleimide-containing prodrugs can quickly and selectively react with circulating serum albumin following their injection in the bloodstream. The drug-albumin complex then benefits from longer blood circulation times and better tumor accumulation. Herein, we have applied this strategy to a previously reported highly phototoxic Ru polypyridyl complex-based photosensitizer to increase its accumulation at the tumor, reduce off-target cytotoxicity, and therefore improve its pharmacological profile. Specifically, two complexes were synthesized bearing a maleimide group: one complex with the maleimide directly incorporated into the bipyridyl ligand, and the other has a hydrophilic linker between the ligand and the maleimide group. Their interaction with albumin was studied in-depth, revealing their ability to efficiently bind both covalently and noncovalently to the plasma protein. A crucial finding is that the maleimide-functionalized complexes exhibited significantly lower cytotoxicity in noncancerous cells under dark conditions compared to the nonfunctionalized complex, which is a highly desirable property for a photosensitizer. The binding to albumin also led to a decrease in the phototoxicity of the Ru bioconjugates in comparison to the nonfunctionalized complex, probably due to a decreased cellular uptake. Unfortunately, this decrease in phototoxicity was not compensated by a dramatic increase in tumor accumulation, as was demonstrated in a tumor-bearing mouse model using inductively coupled plasma mass spectrometry (ICP-MS) studies. Consequently, this study provides valuable insight into the future design of in situ albumin-binding complexes for photodynamic therapy in order to maximize their effectiveness and realize their full potential.

Differential Spectrum of Albumin Glycation, Oxidation, and Truncation in Type 2 and Type 1 Diabetes: Clinical and Biological Implications

Background: Albumin, the most abundant and physiologically vital serum protein, accumulates a range of chemical modifications, as consequence of encounters with large number of reactive molecules whose concentrations increase in serum under pathological conditions. Methods: In a "proof of concept" study, mass spectrometric analysis was utilized to quantitate albumin post-translational modifications (glycation, oxidation, and truncation; individual isoforms and total) in four informative subject groups [type 1 diabetes (T1DM), type 2 diabetes (T2DM), prediabetes-obesity and healthy; all with estimated glomerular filtration rate ≥60 mL/(min·m2)]. Besides glycated albumin (GA/mass spectrometry), glycated serum protein (GSP/nitro blue tetrazolium colorimetry), and glycated hemoglobin (HbA1c/high-performance liquid chromatography) were also measured. Results: A wide spectrum of albumin molecular modifications was identified in diabetes, with significant differences between T2DM and T1DM. Albumin glycation: GA correlated more strongly with HbA1c in T1DM, compared to T2DM. Higher albumin glycation isoforms (human serum albumin +3G/2G) were more stable and discriminative markers of mean glycemia. Albumin oxidation: T2DM, in comparison with T1DM, showed enhanced oxidative and dual (glycation plus oxidation) modifications, representing extreme molecular pathology. Albumin truncation: There was dramatic reduction ("deficiency") of truncated albumin isoforms in T2DM, and significant reduction in T1DM. Albumin truncation negatively correlated with severity of albumin glycation (mean glycemia) and albumin oxidation (cysteinylation). Possible mechanisms of insulin resistance, with associated increased free fatty acids binding to albumin, in stimulating albumin oxidation and inhibiting albumin glycation ("metabolic cross talks") are reviewed. Conclusions: Albumin molecular modifications in diabetes, together with significant differences between T2DM and T1DM, suggest possible role for insulin resistance in their genesis and consequent cell, tissue, and vascular dysfunction/damage. Albumin molecular fingerprinting can provide valuable insights into pathogenesis, diagnosis, monitoring, and future therapies for diabetes. Identification of biomarker battery ("albuminomics," "diabetomics") driven diverse "healthy," prediabetes, obesity, and T2DM phenotypes represents additional novel step toward precision medicine in diabetes and related disorders.

Association between serum trace elements and sleep disturbance in patients with decompensated cirrhosis

Background

Sleep disturbance and trace elements imbalance are common features in patients with decompensated cirrhosis, partially sharing similar mechanistic contributors and linking to adverse outcomes. However, there is a paucity of data concerning their relationship.

Objectives

To investigate the association between serum trace elements levels and sleep quality in the context of cirrhosis.

Design

Cross-sectional study.

Methods

We consecutively enrolled 160 patients with decompensated cirrhosis. The sleep disturbance was determined by the Pittsburgh Sleep Quality Index (PSQI > 5). Serum trace elements [magnesium, calcium, iron, copper (Cu), zinc (Zn), lead, and manganese] was measured by inductively coupled plasma mass spectrometry. Association of examined trace elements levels and sleep disturbance was analyzed by multiple linear (global PSQI scores) and multivariate logistic (dichotomized PSQI categories) regression models, respectively.

Results

In total, 91 patients (56.88%) represented PSQI-defined sleep disturbance, characterized by female preponderance, lower body mass index levels, and higher serum Cu levels (all p < 0.05). Looking into its clinical relevance with debilitating conditions, we showed that Cu/Zn ratio (CZr) is significantly higher in cirrhosis with poor sleep quality (1.77 versus 1.48, p = 0.003). Diagnostic performance analysis indicated CZr > 1.62 to exhibit better discrimination relative to respective Cu. Both multiple linear (β = 0.355, p < 0.001) and multivariate logistic regression (odds ratio = 2.364, p = 0.019) identified higher CZr as an independent risk factor associated with sleep disturbance.

Conclusion

Our findings implied an association between higher CZr and the presence of sleep disturbance in patients with decompensated cirrhosis.

Determination of binding characteristics as a measure for effective albumin using different methods

BACKGROUND & AIMS

Transport functions of albumin are of clinical and pharmacological interest and are determined by albumin's properties like posttranslational modifications or bound ligands. Both are affected in pathological conditions and in therapeutic grade albumin solutions. The term effective albumin concentration was introduced as a measure of functionally intact albumin. Our aim was to evaluate the impact of ligands and modifications with different approaches as a measure of effective albumin.

APPROACH & RESULTS

We used a spin labelled fatty acid and dansylsarcosine to characterize binding properties of albumin i) prepared from plasma of patients and healthy control donors, ii) measured directly out of plasma, iii) research grade albumin, iv) in vitro modified albumin, and v) therapeutic infusion solutions before and after removal of stabilizers. Bilirubin is the main determinant for binding function in patients' albumin. In in vitro prepared albumin bound fatty acids correlated with impaired binding. Human nonmercaptalbumin1, not human nonmercaptalbumin2, showed reduced binding properties. Binding and transport function of therapeutic albumin was severely impaired and restored by filtration. Glycation of research grade albumin had no effect on the binding of dansylsarcosine and only a minor effect on fatty acid binding.

CONCLUSIONS

Our results suggest that effective albumin -in terms of binding properties- is primarily determined by bound ligands and only to a minor extent by posttranslational modifications. Characterizing albumin directly from plasma better reflects the physiological situation whereas in the case of therapeutic grade albumin stabilizers should be removed to make its binding properties accessible.

Bioimaging of glutathione variation for early diagnosis of hepatocellular carcinoma using a liver-targeting ratiometric near-infrared fluorescent probe

Reliable biomarkers are crucial for early diagnosis of diseases and precise therapy. Biological thiols (represented by glutathione, GSH) play vital roles in the antioxidant defense system for maintaining intracellular redox homeostasis in organisms. However, the aberrant variation in the cellular concentration of GSH correlates with diverse diseases including cancer. Here, a ratiometric near-infrared fluorescent probe CyO-Disu is constructed for the specific sensing of GSH variation in live cells and mice models of hepatic carcinoma (HCC). CyO-Disu features three key elements, a response moiety of bis(2-hydroxyethyl) disulfide, a near-infrared fluorescence signal transducer of heptamethine ketone cyanine, and a targeting moiety of D-galactose. By virtue of its liver-targeting capability, CyO-Disu was utilized for evaluating GSH fluctuations in primary and metastatic hepatoma living cells. To evaluate the efficacy of CyO-Disuin vivo, orthotopic HCC and pulmonary metastatic hepatoma mice models were employed for GSH imaging using two-dimensional and three-dimensional fluorescence molecular tomographic imaging systems. The bioimaging results offered direct evidence that GSH displayed varied concentrations during the progression of HCC. Therefore, the as-synthesized probe CyO-Disu could serve as a potential powerful tool for the early diagnosis and precise treatment of HCC using GSH as a reliable biomarker.

Effect of Low-Dose Line-Spectrum and Full-Spectrum UV on Major Humoral Components of Human Blood

Ultraviolet blood irradiation (UVBI) is an alternative approach to the treatment of infectious diseases of various pathogeneses. Recently, UVBI has attracted particular interest as a new immunomodulatory method. Experimental studies available in the literature demonstrate the absence of precise mechanisms of the effect of ultraviolet radiation (UV) on blood. Here, we investigated the effect of UV radiation of line-spectrum mercury lamp (doses up to 500 mJ/cm²) traditionally used in UVBI on the major humoral blood components: albumin, globulins and uric acid. Preliminary data on the effect of various doses of UV radiation of full-spectrum flash xenon lamp (doses up to 136 mJ/cm²), a new promising source for UVBI, on the major blood plasma protein, albumin, are presented. The research methodology included spectrofluorimetric analysis of the oxidative modification of proteins and analysis of the antioxidant activity of humoral blood components by chemiluminometry. The effect of UV radiation on albumin caused its oxidative modification and, accordingly, an impairment of the transport properties of the protein. At the same time, UV-modified albumin and γ-globulins acquired pronounced antioxidant properties compared to native samples. Uric acid mixed with albumin did not protect the protein against UV-induced oxidation. The flash full-spectrum UV qualitatively had the same effect on albumin as line-spectrum UV did, but an order of magnitude lower doses were required to achieve comparable effects. The suggested protocol can be used for selecting a safe individual dose for UV therapy.

Case report: therapeutic monitoring of vancomycin in an acute liver failure patient with anuria under high-flow continuous hemodiafiltration

BACKGROUND

High-flow continuous hemodiafiltration (HF-CHDF) combines diffusive and convective solute removal and is employed for artificial liver adjuvant therapy. However, there is no report on dosage planning of vancomycin (VCM) in patients with acute liver failure under HF-CHDF.

CASE PRESENTATION

A 20-year-old woman (154 cm tall, weighing 50 kg) was transferred to the intensive care unit (ICU) with acute liver failure associated with autoimmune liver disease. On the following day, HF-CHDF was started due to elevated plasma ammonia concentration. On ICU day 8, VCM was started for suspected pneumonia and meningitis (30 mg/kg loading dose, then 20 mg/kg every 12 hrs). However, on ICU day 10, VCM blood concentration was under the limit of detection (< 3.0 μg/mL) and the patient developed anuria. The VCM dose was increased to 20 mg/kg every 6 hrs. Calculation with a one-compartment model using the HF-CHDF blood flow rate as a surrogate for VCM clearance, together with hematocrit and protein binding ratio, predicted a trough VCM blood concentration of 15 μg/mL. The observed concentration was about 12 μg/mL. The difference may represent non-HF-CHDF clearance. Finally, living donor liver transplantation was performed.

CONCLUSION

We report an acute liver failure patient with anuria under HF-CHDF in whom VCM administration failed to produce an effective blood concentration, likely due to HF-CHDF-enhanced clearance. VCM dosage adjustment proved successful, and was confirmed by calculation using a one-compartment model.

Agomelatine's antiglycoxidative action-In vitro and in silico research and systematic literature review

Introduction

Agomelatine is an atypical antidepressant drug enhancing norepinephrine and dopamine liberation; nevertheless, additional mechanisms are considered for the drug's pharmacological action. Since protein glycoxidation plays a crucial role in depression pathogenesis, agomelatine's impact on carbonyl/oxidative stress was the research purpose.

Methods

Reactive oxygen species scavenging (hydroxyl radical, hydrogen peroxide, and nitrogen oxide) and antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl radical and ferrous ion chelating assays) of agomelatine were marked. Agomelatine's antiglycoxidation properties were assayed in sugars (glucose, fructose, and galactose) and aldehydes- (glyoxal and methylglyoxal) glycated bovine serum albumin (BSA). Aminoguanidine and α-lipoic acid were used as standard glycation/oxidation inhibitors.

Results

Agomelatine did not show meaningful scavenging/antioxidant capacity vs. standards. Sugars/aldehydes increased glycation (↑kynurenine, ↑N-formylkynurenine, ↑dityrosine, ↑advanced glycation end products, and ↑β-amyloid) and oxidation (↑protein carbonyls and ↑advanced oxidation protein products) parameters in addition to BSA. Standards restored BSA baselines of glycation and oxidation markers, unlike agomelatine which sometimes even intensifies glycation above BSA + glycators levels. Molecular docking analysis of agomelatine in BSA demonstrated its very weak binding affinity.

Discussion

Agomelatine's very low affinity to the BSA could proclaim non-specific bonding and simplify attachment of glycation factors. Thereby, the drug may stimulate brain adaptation to carbonyl/oxidative stress as the systematic review indicates. Moreover, the drug's active metabolites could exert an antiglycoxidative effect.

Association between fibrinogen-to-albumin ratio and hemorrhagic transformation after intravenous thrombolysis in ischemic stroke patients

BACKGROUND AND PURPOSE

Hemorrhagic transformation (HT) is the most serious complication of intravenous thrombolysis in ischemic stroke patients. Inflammation plays a critical role in the pathological progression of HT. This study was to explore the relationship between fibrinogen-to-albumin ratio (FAR), a novel systemic inflammation biomarker, and HT after intravenous thrombolysis in patients with ischemic stroke.

METHODS

This retrospective study enrolled ischemic stroke patients who underwent intravenous thrombolysis between Jan 2017 to May 2022. The characteristic data of all patients at admission were retrospectively collected. The univariate and multivariate logistic regression analyses were performed to evaluate the correlation between FAR and HT after intravenous thrombolysis. The optimal cut-off value of FAR for predicting HT was determined by the receiver operating characteristic curve.

RESULTS

A total of 363 ischemic stroke patients were enrolled in the present study. Sixty-two patients had HT after intravenous thrombolysis. In multivariate regression analysis, FAR was significantly associated with HT (odds ratio [OR], 1.105; 95% confidential interval [CI], 1.029-1.186, P = 0.006). The receiver operating characteristic curve analysis indicated FAR predicts HT after intravenous thrombolysis with an AUC of 0.613 (95%CI, 0.530-0.695; P = 0.005) and an optimal cut-off value of 0.101. The correlation between FAR and HT after intravenous thrombolysis was still observed when patients were stratified according to FAR levels. A higher FAR level was independently related to the occurrence of HT after adjusting for the potential confounding factors.

CONCLUSION

Higher FAR level was independently associated with HT after intravenous thrombolysis in patients with ischemic stroke.

Food Antioxidants and Their Interaction with Human Proteins

Common to all biological systems and living organisms are molecular interactions, which may lead to specific physiological events. Most often, a cascade of events occurs, establishing an equilibrium between possibly competing and/or synergistic processes. Biochemical pathways that sustain life depend on multiple intrinsic and extrinsic factors contributing to aging and/or diseases. This article deals with food antioxidants and human proteins from the circulation, their interaction, their effect on the structure, properties, and function of antioxidant-bound proteins, and the possible impact of complex formation on antioxidants. An overview of studies examining interactions between individual antioxidant compounds and major blood proteins is presented with findings. Investigating antioxidant/protein interactions at the level of the human organism and determining antioxidant distribution between proteins and involvement in the particular physiological role is a very complex and challenging task. However, by knowing the role of a particular protein in certain pathology or aging, and the effect exerted by a particular antioxidant bound to it, it is possible to recommend specific food intake or resistance to it to improve the condition or slow down the process.

Relationship between human serum albumin and in-hospital mortality in critical care patients with chronic obstructive pulmonary disease

Background

The relationship between human serum albumin levels and the prognosis of critical care patients with chronic obstructive pulmonary disease (COPD) remains controversial.

Objective

To investigate the relationship between serum albumin levels and in-hospital mortality in critical care patients with COPD. METHODS: This study used a retrospective observational cohort from the Medical Information in Intensive Care database (MIMIC-IV) in the United States. Multivariate Cox regression analysis was used to assess the relationship between serum albumin levels and in-hospital mortality. A restricted cubic spline line was also used to explore nonlinear relationship.

Results

A total of 3,398 critical care patients with COPD were included. The overall in-hospital mortality was 12.4%. We found a negative relationship between human serum albumin and in-hospital mortality (HR = 0.97, 95% CI 0.96-0.99, p = 0.002).

Conclusion

In critical care patients with COPD, there was a negative association between human serum albumin and in-hospital mortality.

Sympathectomy Effects on Intra-Abdominal Organ Catecholamine Levels in a Streptozotocin-Induced Diabetic Rat Model

Diabetes mellitus (DM) is a metabolic disorder whose prevalence has continuously increased worldwide and is associated with dysfunction of the autonomic nervous system and, in particular, that of the sympathetic nervous system (SNS). The objective of this study was to analyze the interaction of DM and the SNS, building a model of sympathectomized diabetic rats to determine alterations in the content of CA (catecholamines) in different intra-abdominal organs. Sympathectomy was conducted with guanethidine (GNT). Additionally, DM was induced with STZ (Streptozotocin). Treatment with GNT decreased norepinephrine (NE) content in all analyzed tissues, with significant differences found in the paraganglia, liver, pancreas, duodenum, and heart compared to the control group. With respect to epinephrine (E), which was only found in the liver, pancreas, and heart, presenting significant differences (p < 0.05) in the heart, a decrease in its concentration was observed for all of the experimental groups with respect to the control. The decrease in dopamine (DA) content due to the GNT−STZ treatment was 30.1% in the heart with respect to the diabetic (STZ) group. The amount of CA in the adrenal medulla indicates the effect of sympathectomy on the GNT group where there was a significant reduction (p < 0.05) of DA. These findings suggest that the elimination of the sympathetic nervous system in diabetic organisms contributed to a decrease in blood glucose; likewise, an alteration in the levels of CA was observed in the different selected organs, possibly attributed to the severity, duration, and pathogenesis of the complications of acute and chronic DM.

Redox State of Human Serum Albumin in Multiple Sclerosis: A Pilot Study

Like in many other pathologies, oxidative stress is involved in the development of neurodegenerative disorders. Human serum albumin (HSA) is the main protein in different body fluids including cerebrospinal fluid (CSF). By its redox state in terms of cysteine-34, albumin serves as marker for oxidative burden. We aimed to evaluate the redox state of HSA in patients with multiple sclerosis in serum and CSF in comparison to controls to identify possible correlations with disease activity and severity. Samples were stored at -70 °C until analysis by HPLC for the determination of albumin redox state in terms of the fractions of human mercaptalbumin (HMA), human nonmercaptalbumin1 (HNA1), and human nonmercaptalbumin2 (HNA2). Albumin in CSF showed significantly higher fractions of the reduced form HMA and decreased HNA1 and HNA2. There was no difference between albumin redox states in serum of patients and controls. In CSF of patients HNA2 showed a trend to higher fractions compared to controls. Albumin redox state in serum was associated with physical disability in remission while albumin redox state in CSF was related to disease activity. Thus, albumin redox state in serum and CSF of patients in relation to disease condition merits further investigation.

Albumin as a Biomaterial and Therapeutic Agent in Regenerative Medicine

Albumin is a constitutional plasma protein, with well-known biological functions, e.g., a nutrient for stem cells in culture. However, albumin is underutilized as a biomaterial in regenerative medicine. This review summarizes the advanced therapeutic uses of albumin, focusing on novel compositions that take advantage of the excellent regenerative potential of this protein. Albumin coating can be used for enhancing the biocompatibility of various types of implants, such as bone grafts or sutures. Albumin is mainly known as an anti-attachment protein; however, using it on implantable surfaces is just the opposite: it enhances stem cell adhesion and proliferation. The anticoagulant, antimicrobial and anti-inflammatory properties of albumin allow fine-tuning of the biological reaction to implantable tissue-engineering constructs. Another potential use is combining albumin with natural or synthetic materials that results in novel composites suitable for cardiac, neural, hard and soft tissue engineering. Recent advances in materials have made it possible to electrospin the globular albumin protein, opening up new possibilities for albumin-based scaffolds for cell therapy. Several described technologies have already entered the clinical phase, making good use of the excellent biological, but also regulatory, manufacturing and clinical features of serum albumin.

Binding of temocillin to plasma proteins in vitro and in vivo: the importance of plasma protein levels in different populations and of co-medications

BACKGROUND

Temocillin plasma protein binding (PPB) in healthy individuals is reported to be ∼85% but had not been studied in patients.

OBJECTIVES

To obtain normative data on temocillin PPB in patients in relation to infection and impact of co-medications widely used in ICU.

METHODS

Plasma was obtained from healthy individuals (Group #1), non-ICU patients with UTI (Group #2), ICU patients with suspected/confirmed ventriculitis (Group #3) or with sepsis/septic shock (Group #4). Total and unbound temocillin concentrations were measured in spiked samples from temocillin-naive donors (in vitro) or in plasma from temocillin-treated subjects (in vivo). The impact of diluting plasma, using pharmaceutical albumin, or adding drugs potentially competing for PPB was tested in spiked samples. Data were analysed using a modified Hill-Langmuir equation taking ligand depletion into account.

RESULTS

Temocillin PPB was saturable in all groups, both in vitro and in vivo. Maximal binding capacity (Bmax) was 1.2-2-fold lower in patients. At 20 and 200 mg/L (total concentrations), the unbound fraction reached 12%-29%, 23%-42% and 32%-52% in Groups #2, #3, #4. The unbound fraction was inversely correlated with albumin and C-reactive protein concentrations. Binding to albumin was 2-3-fold lower than in plasma and non-saturable. Drugs with high PPB but active at lower molar concentrations than temocillin caused minimal displacement, while fluconazole (low PPB but similar plasma concentrations to temocillin) increased up to 2-fold its unbound fraction.

CONCLUSIONS

Temocillin PPB is saturable, 2-4-fold lowered in infected patients in relation to disease severity (ICU admission, hypoalbuminaemia, inflammation) and only partially reproducible with albumin. Competition with other drugs must be considered for therapeutic concentrations to be meaningful.

Analysis of routine blood parameters in patients with amyotrophic lateral sclerosis and evaluation of a possible correlation with disease progression—a multicenter study

Objective

Amyotrophic lateral sclerosis (ALS) pathogenesis is still unclear, its course is considerably variable, and prognosis is hard to determine. Despite much research, there is still a lack of easily accessible markers predicting prognosis. We investigated routine blood parameters in ALS patients regarding correlations with disease severity, progression rate, and survival. Additionally, we analyzed disease and patients' characteristics relating to baseline blood parameter levels.

Methods

We analyzed creatine kinase (CK), albumin (ALB), creatinine (CREA), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), and triglycerides (TG) levels around time of diagnosis in 1,084 ALS patients. We carried out linear regression analyses including disease and patients' characteristics with each blood parameter to detect correlations with them. Linear regression models were performed for ALSFRS-R at study entry, its retrospectively defined rate of decay and prospectively collected progression rate. Different survival analysis methods were used to examine associations between blood parameters and survival.

Results

We found higher CK (p-value 0.001), ALB (p-value <0.001), CREA (p-value <0.001), and HDL levels (p-value 0.044) at time of diagnosis being associated with better functional status according to ALSFRS-R scores at study entry. Additionally, higher CREA levels were associated with lower risk of death (p-value 0.003).

Conclusions

Our results indicate potential of CK, ALB, CREA, and HDL as disease severity or progression markers, and may also provide clues to ALS pathogenesis. However, these values are highly dependent on other variables, and further careful, longitudinal analyses will be necessary to prove the relevance of our findings.

Albumin at the intersection between antioxidant and pro-oxidant in patients on peritoneal dialysis

Albumin (HSA) is a multifunctional protein and due to its free Cys34 thiol group, represents a main source of free thiols in the circulation. This property of HSA, combined with its ability to sequester redox active Cu(II) ions, makes HSA a dominant circulatory antioxidant. End stage kidney disease (ESRD) is a condition accompanied by elevated oxidative stress. The aim of the present study was to examine changes in the antioxidative capacity of HSA and Cu(II) binding affinity in patients on peritoneal dialysis (PD), and relate it to the Cys34 thiol group content and other structural changes of this molecule. HSA molecules are modified in ESRD patients subjected to PD, having significantly lower thiol group and bound Cu(II) content, reduced antioxidant capacity, an increased content of advanced glycation end-products and altered conformation. Also, Cu(II) binding capacity of HSA in these patients is impaired, since a significant portion of the high-affinity metal-binding site is unable to interact with Cu(II). Taking into account that the concentration of Cu(II) in the circulation of ESRD patients is much higher than in healthy persons and that Cu(II) binding capacity of HSA in these patients is significantly impaired, HSA may be considered as a novel circulatory pro-oxidant, thus exacerbating oxidative stress.

Clinical Significance of Serum Albumin and Implications of FcRn Inhibitor Treatment in IgG-Mediated Autoimmune Disorders

Serum albumin (SA), the most abundant soluble protein in the body, maintains plasma oncotic pressure and regulates the distribution of vascular fluid and has a range of other important functions. The goals of this review are to expand clinical knowledge regarding the functions of SA, elucidate effects of dysregulated SA concentration, and discuss the clinical relevance of hypoalbuminemia resulting from various diseases. We discuss potential repercussions of SA dysregulation on cholesterol levels, liver function, and other processes that rely on its homeostasis, as decreased SA concentration has been shown to be associated with increased risk for cardiovascular disease, hyperlipidemia, and mortality. We describe the anti-inflammatory and antioxidant properties of SA, as well as its ability to bind and transport a plethora of endogenous and exogenous molecules. SA is the primary serum protein involved in binding and transport of drugs and as such has the potential to affect, or be affected by, certain medications. Of current relevance are antibody-based inhibitors of the neonatal Fc receptor (FcRn), several of which are under clinical development to treat immunoglobulin G (IgG)-mediated autoimmune disorders; some have been shown to decrease SA concentration. FcRn acts as a homeostatic regulator of SA by rescuing it, as well as IgG, from intracellular degradation via a common cellular recycling mechanism. Greater clinical understanding of the multifunctional nature of SA and the potential clinical impact of decreased SA are needed; in particular, the potential for certain treatments to reduce SA concentration, which may affect efficacy and toxicity of medications and disease progression.

Treatment-Interval Changes in Serum Levels of Albumin and Histidine Correlated with Treatment Interruption in Patients with Locally Advanced Head and Neck Squamous Cell Carcinoma Completing Chemoradiotherapy under Recommended Calorie and Protein Provision

We investigated risk factors for treatment interruption (TI) in patients with locally advanced head and neck squamous-cell carcinoma (LAHNSCC) following concurrent chemoradiotherapy (CCRT), under the provision of recommended calorie and protein intake; we also evaluated the associations between clinicopathological variables, calorie and protein supply, nutrition–inflammation biomarkers (NIBs), total body composition change (TBC), and a four-serum-amino-acid metabolite panel (histidine, leucine, ornithine, and phenylalanine) among these patients. Patients with LAHNSCC who completed the entire planned CCRT course and received at least 25 kcal/kg/day and 1 g of protein/kg/day during CCRT were prospectively recruited. Clinicopathological variables, anthropometric data, blood NIBs, CCRT-related factors, TBC data, and metabolite panels before and after treatment were collected; 44 patients with LAHNSCC were enrolled. Nine patients (20.4%) experienced TIs. Patients with TIs experienced greater reductions in hemoglobin, serum levels of albumin, uric acid, histidine, and appendicular skeletal mass, and suffered from more grade 3/4 toxicities than those with no TI. Neither increased daily calorie supply (≥30 kcal/kg/day) nor feeding tube placement was correlated with TI. Multivariate analysis showed that treatment-interval changes in serum albumin and histidine levels, but not treatment toxicity, were independently associated with TI. Thus, changes in serum levels of albumin and histidine over the treatment course could cause TI in patients with LAHNSCC following CCRT.

In Vitro Reactivity of the Glucose Degradation Product 3,4-Dideoxyglucosone-3-ene (3,4-DGE) towards Abundant Components of the Human Blood Circulatory System

3,4-Dideoxyglucosone-3-ene (3,4-DGE) is a glucose degradation product present in processed foods and medicinal products. Additionally, its constant formation from 3-deoxyglucosone in plasma has been suggested. Due to its α,β-unsaturated dicarbonyl moiety, 3,4-DGE is highly reactive and has shown harmful effects in vitro. Here, we investigated the impact of major components of the human blood circulatory system on 3,4-DGE in vitro. Under physiological conditions, plasma concentrations of human serum albumin (HSA) reacted efficiently with 3,4-DGE, resulting in only 8.5% of the initial 3,4-DGE concentration after seven hours (vs. 83.4% without HSA, p < 0.001). Thereby, accessible thiol groups were reduced from 0.121 to 0.064 mol/mol HSA, whereas ketoprofen binding and esterase-like activity of HSA were not affected. Plasma concentrations of glutathione (GSH) reacted immediately and completely with 3,4-DGE, leading to two stereoisomeric adducts. Plasma concentrations of immunoglobulin G (IgG) bound to 3,4-DGE to a lower extent, resulting in 62.6% 3,4-DGE after seven hours (vs. 82.2% in the control, p < 0.01). Immobilized human collagen type IV did not alter 3,4-DGE concentrations. The results indicated that particularly HSA, GSH, and IgG readily scavenge 3,4-DGE after its appearance in the blood stream, which may be associated with a reduced antioxidative and cytoprotective activity for the living cells and, thus, the human organism by blocking free thiol groups.

Albumin Uptake and Processing by the Proximal Tubule: Physiologic, Pathologic and Therapeutic Implications

For nearly 50 years the proximal tubule (PT) has been known to reabsorb, process, and either catabolize or transcytose albumin from the glomerular filtrate. Innovative techniques and approaches have provided insights into these processes. Several genetic diseases, nonselective PT cell defects, chronic kidney disease (CKD), and acute PT injury lead to significant albuminuria, reaching nephrotic range. Albumin is also known to stimulate PT injury cascades. Thus, the mechanisms of albumin reabsorption, catabolism, and transcytosis are being reexamined with the use of techniques that allow for novel molecular and cellular discoveries. Megalin, a scavenger receptor, cubilin, amnionless, and Dab2 form a nonselective multireceptor complex that mediates albumin binding and uptake and directs proteins for lysosomal degradation after endocytosis. Albumin transcytosis is mediated by a pH-dependent binding affinity to the neonatal Fc receptor (FcRn) in the endosomal compartments. This reclamation pathway rescues albumin from urinary losses and cellular catabolism, extending its serum half-life. Albumin that has been altered by oxidation, glycation, or carbamylation or because of other bound ligands that do not bind to FcRn traffics to the lysosome. This molecular sorting mechanism reclaims physiological albumin and eliminates potentially toxic albumin. The clinical importance of PT albumin metabolism has also increased as albumin is now being used to bind therapeutic agents to extend their half-life and minimize filtration and kidney injury. The purpose of this review is to update and integrate evolving information regarding the reabsorption and processing of albumin by proximal tubule cells including discussion of genetic disorders and therapeutic considerations.

High fibrinogen-to-albumin ratio with type 2 diabetes mellitus is associated with poor prognosis in patients undergoing percutaneous coronary intervention: 5-year findings from a large cohort

BACKGROUND

Inflammation plays a crucial role in coronary atherosclerosis progression, and growing evidence has demonstrated that the fibrinogen-to-albumin ratio (FAR), as a novel inflammation biomarker, is associated with the severity of coronary artery disease (CAD). However, the long-term risk of cardiovascular events remains indistinct in patients with different level of FAR and different glycemic metabolism status. This study was to assess 5-year clinical outcomes of diabetic and non-diabetic patients who underwent percutaneous coronary intervention (PCI) with different level of FAR.

METHODS

We consecutively enrolled 10,724 patients with CAD hospitalized for PCI and followed up for the major adverse cardiac and cerebrovascular events (MACCE) covering all-cause mortality, cardiac mortality, non-fatal myocardial infarction, non-fatal ischemic stroke, and unplanned coronary revascularization. FAR was computed using the following formula: Fibrinogen (g/L)/Albumin (g/L). According to the optimal cut-off value of FAR for MACCE prediction, patients were divided into higher level of FAR (FAR-H) and lower level of FAR (FAR-L) subgroups, and were further categorized into four groups as FAR-H with DM and non-DM, and FAR-L with DM and non-DM.

RESULTS

5298 patients (58.36 ± 10.36 years, 77.7% male) were ultimately enrolled in the present study. A total of 1099 (20.7%) MACCEs were documented during the 5-year follow-up. The optimal cut-off value of FAR was 0.0783 by the surv_cutpoint function. Compared to ones with FAR-H and DM, patients with FAR-L and non-DM, FAR-H and non-DM, FAR-L and DM had decreased risk of MACCEs [adjusted hazard ratio (HR): 0.75, 95% confidence interval (CI) 0.64-0.89, P = 0.001; HR: 0.78, 95% CI 0.66-0.93, P = 0.006; HR: 0.81, 95% CI 0.68-0.97, P = 0.019; respectively]. Notably, non-diabetic patients with lower level of FAR also had lower all-cause mortality and cardiac mortality risk than those in the FAR-H/DM group (HR: 0.41, 95% CI 0.27-0.63, P < 0.001; HR: 0.30, 95% CI 0.17-0.53, P < 0.001; respectively). Multivariate Cox proportional hazards regression analysis also indicated the highest risk of MACCEs in patients with FAR-H and DM than others (P for trend = 0.005). In addition, post-hoc analysis revealed consistent effects on 5-year MACCE across various subgroups.

CONCLUSION

In this real-world cohort study, higher level of FAR combined with DM was associated with worse 5-year outcomes among patients with CAD undergoing PCI. The level of FAR may help to identify high-risk individuals in this specific population, where more precise risk assessment should be performed.

Blood Thiol Redox State in Chronic Kidney Disease

Thiols (sulfhydryl groups) are effective antioxidants that can preserve the correct structure of proteins, and can protect cells and tissues from damage induced by oxidative stress. Abnormal levels of thiols have been measured in the blood of patients with moderate-to-severe chronic kidney disease (CKD) compared to healthy subjects, as well as in end-stage renal disease (ESRD) patients on haemodialysis or peritoneal dialysis. The levels of protein thiols (a measure of the endogenous antioxidant capacity inversely related to protein oxidation) and S-thiolated proteins (mixed disulphides of protein thiols and low molecular mass thiols), and the protein thiolation index (the molar ratio of the S-thiolated proteins to free protein thiols in plasma) have been investigated in the plasma or red blood cells of CKD and ESRD patients as possible biomarkers of oxidative stress. This type of minimally invasive analysis provides valuable information on the redox status of the less-easily accessible tissues and organs, and of the whole organism. This review provides an overview of reversible modifications in protein thiols in the setting of CKD and renal replacement therapy. The evidence suggests that protein thiols, S-thiolated proteins, and the protein thiolation index are promising biomarkers of reversible oxidative stress that could be included in the routine monitoring of CKD and ESRD patients.

The Interplay between Uremic Toxins and Albumin, Membrane Transporters and Drug Interaction

Uremic toxins are a heterogeneous group of molecules that accumulate in the body due to the progression of chronic kidney disease (CKD). These toxins are associated with kidney dysfunction and the development of comorbidities in patients with CKD, being only partially eliminated by dialysis therapies. Importantly, drugs used in clinical treatments may affect the levels of uremic toxins, their tissue disposition, and even their elimination through the interaction of both with proteins such as albumin and cell membrane transporters. In this context, protein-bound uremic toxins (PBUTs) are highlighted for their high affinity for albumin, the most abundant serum protein with multiple binding sites and an ability to interact with drugs. Membrane transporters mediate the cellular influx and efflux of various uremic toxins, which may also compete with drugs as substrates, and both may alter transporter activity or expression. Therefore, this review explores the interaction mechanisms between uremic toxins and albumin, as well as membrane transporters, considering their potential relationship with drugs used in clinical practice.

The lipid components of high-density lipoproteins (HDL) are essential for the binding and transportation of antimicrobial peptides in human serum

Antimicrobial peptides (AMPs) have been developed for the treatment of bacterial infections, but their applications are limited to topical infections since they are sequestered and inhibited in serum. Here we have discovered that the inhibition of AMPs by human serum was mediated through high-density lipoproteins (HDL) which are known to remove cholesterol from peripheral tissues. The susceptibility of AMPs to HDL varied depending on the degree of hydrophobicity of AMPs and their binding affinities to HDL. The phospholipids, such as phosphatidylcholine, of HDL were essential for AMP-binding. The dynamic binding interactions between AMPs and HDL were mediated through the hydrophobic interactions rather than by ionic strength. Interestingly, some AMPs, such as SMAP29, dissociated from the AMP-HDL complex and translocated to bacteria upon contact, while some AMPs, such as LL37, remained in complex with HDL. These results suggest that HDL binds AMPs and facilitates the translocation of them to the bacteria.

Why Intermolecular Nitric Oxide (NO) Transfer? Exploring the Factors and Mechanistic Aspects of NO Transfer Reaction

Small molecule activation & their transfer reactions in biological or catalytic reactions are greatly influenced by the metal-centers and the ligand frameworks. Here, we report the metal-directed nitric oxide (NO)...

ADS Score as a Novel Predictor of Outcomes in Patients Who Underwent Percutaneous Coronary Intervention

Objectives: A novel AFR– albumin-derived neutrophil to lymphocyte ratio (dNLR) score (ADS) were reported to associate with clinical outcome in various malignancies, However, the relation between the ADS score and outcomes in coronary artery disease (CAD) patients after percutaneous coronary intervention (PCI) has not been investigated.

Methods: Three thousand five hundred and sixty-one patients were divided into two groups according to ADS score: low group (ADS score <2; n = 2,682) and high group (ADS score ≥ 2; n = 879). Overall, there were 133 all-cause mortality (ACM) during the following up. The incidence of ACM in the low group is 2.7% (72/2,682) and high group is 6.9% (61/879). The ACM incidence was significantly higher in high group compared to that in the low group (P < 0.001). Cardiac mortality (CM) occurred in 82 patients: 44(1.6%) in the low group and 38 (4.3%) in the high group. There was significant difference in the CM incidence between the low group and high group (P < 0.001). Major adverse cardiac and cerebrovascular events (MACCE) occurred in 520 patients: 366 (13.6%) in the low group and 154 (17.5%) in the high group. There was significant difference in the MACCE incidence between the low group and high group (P = 0.005). Major adverse cardiac and events (MACE) occurred in 395 patients: 281(10.5%) in the low group and 114 (13.0%) in the high group. There was significant difference in the MACE incidence between the low group and high group (P = 0.041). The multivariate Cox proportional hazards model showed that ADS score was independently correlated with the ACM [adjusted HR = 2.031 (1.357–3.039), P = 0.001]; CM [adjusted HR = 1.883 (1.127–3.147), P = 0.016]; MACCE [adjusted HR = 1.352 (1.096–1.668), P = 0.005], and MACE [adjusted HR = 1.260 (0.987–1.608), P = 0.063].

Conclusion: The present study indicated that the ADS score was associated with long-term mortality, the MACCE, and the MACE in CAD patients underwent PCI.

Hypoalbuminemia affects one third of acute pancreatitis patients and is independently associated with severity and mortality

The incidence and medical costs of acute pancreatitis (AP) are on the rise, and severe cases still have a 30% mortality rate. We aimed to evaluate hypoalbuminemia as a risk factor and the prognostic value of human serum albumin in AP. Data from 2461 patients were extracted from the international, prospective, multicentre AP registry operated by the Hungarian Pancreatic Study Group. Data from patients with albumin measurement in the first 48 h (n = 1149) and anytime during hospitalization (n = 1272) were analysed. Multivariate binary logistic regression and Receiver Operator Characteristic curve analysis were used. The prevalence of hypoalbuminemia (< 35 g/L) was 19% on admission and 35.7% during hospitalization. Hypoalbuminemia dose-dependently increased the risk of severity, mortality, local complications and organ failure and is associated with longer hospital stay. The predictive value of hypoalbuminemia on admission was poor for severity and mortality. Severe hypoalbuminemia (< 25 g/L) represented an independent risk factor for severity (OR 48.761; CI 25.276–98.908) and mortality (OR 16.83; CI 8.32–35.13). Albumin loss during AP was strongly associated with severity (p < 0.001) and mortality (p = 0.002). Hypoalbuminemia represents an independent risk factor for severity and mortality in AP, and it shows a dose-dependent relationship with local complications, organ failure and length of stay.

Serum Albumin Level as a Predictor of Outcome in Patients Admitted to Pediatric Intensive Care Units

OBJECTIVE

The aim of this study was to assess serum albumin level on admission to the pediatric intensive care unit (PICU) as a prognostic indicator.

METHODS

A prospective study was conducted in Fayoum University Children's Hospital. The study subjects' demographics and clinical and laboratory data were recorded. Pediatric Risk of Mortality III (PRISM-III) score was calculated. Serum albumin level was assessed within 24 hours from admission. Outcomes included mortality, PICU and hospital stay, need and duration of mechanical ventilation, and inotrope use.

RESULTS

The incidence of admission hypoalbuminemia was 26%. The study subjects had a significantly higher mortality rate than subjects with normal albumin levels (42.3% vs 17.6%, respectively, P = 0.011). Each unit of increase in serum albumin decreased the risk of mortality by 28.9% (odds ratio, 0.289; confidence interval, 0.136-0.615, P = 0.001). Serum albumin showed a fair discriminatory power (area under the curve, 0.738). At a cutoff point of ≤3.7 g/dL, albumin had a 79.2% sensitivity, 67.1% specificity, 43.2% positive predictive value, and 91.1% negative predictive value. Incorporation of serum albumin with PRISM-III score was more predictive of mortality than either predictors alone (area under the curve, 0.802). No significant difference was found between the 2 groups regarding either PICU and hospital stay as well as the need and duration of ventilation.

CONCLUSIONS

In PICUs, admission hypoalbuminemia is a good predictor of mortality. Further studies to confirm the value of adding serum albumin to PRISM-III score are recommended.

Antioxidants Associated With Oncogenic Human Papillomavirus Infection in Women

BACKGROUND

Human papillomavirus (HPV) infection is a major cause of cervical cancer. Studies showed the onset of HPV carcinogenesis may be induced by oxidative stress affecting the host immune system. The association between antioxidants and oncogenic HPV remains unclear. In this study, we aim to identify antioxidants associated with vaginal HPV infection in women.

METHODS

The associations between the 15 antioxidants and vaginal HPV infection status (no, low-risk [LR], and high-risk [HR] HPV) were evaluated using 11 070 women who participated in the 2003-2016 National Health and Nutrition Examination Survey (NHANES).

RESULTS

We identified serum albumin and 4 dietary antioxidants (vitamin A, B2, E, and folate) inversely associated with HR-HPV infection. Women with a low level of albumin (≤39 g/L) have a significantly higher risk of HR-HPV (odds ratio [OR] = 1.4, P = .009 vs >44 g/L). A Nutritional Antioxidant Score (NAS) was developed based on these 4 dietary antioxidants. The women with the lowest quartile NAS had a higher chance of HR-HPV (OR = 1.3, P = .030) and LR-HPV (OR = 1.4, P = .002) compared with the women with the highest quartile NAS.

CONCLUSIONS

We identified 5 antioxidants negatively associated with vaginal HR-HPV infection in women. Our findings provide valuable insights into understanding antioxidants' impact on HPV carcinogenesis.