Preoperative Serum Albumin Levels and Postoperative Acute Kidney Injury in Off-Pump Coronary Artery Bypass Surgery: A Single-Center Study in Bangladesh

Background: Serum albumin, a vital plasma protein, helps maintain intravascular colloidal osmotic pressure, cardiac output, and renal function. Low preoperative serum albumin is linked to poor outcomes, including acute kidney injury (AKI), after off-pump coronary artery bypass (OPCAB) surgery. This study aimed to assess the relationship between preoperative serum albumin levels and early postoperative renal injury. Methods: This prospective comparative cross-sectional study was conducted from August 2019 to February 2021 at the National Heart Foundation Hospital & Research Institute, Bangladesh. It included 160 adult patients with normal preoperative renal function undergoing OPCAB. Patients were divided into two groups: Group A (serum albumin ≥ 4.0 gm/dl) and Group B (serum albumin Results: Preoperative serum albumin was significantly different between groups (Group A: 4.21 ± 0.05 gm/dl, Group B: 3.69 ± 0.04 gm/dl, p = 0.028). Group B had a higher incidence of hypertension (71.25% vs. 51.25%, p st and 3rd postoperative days were higher in Group B (p th day. Postoperative AKI occurred in 18.75% of Group A and 36.25% of Group B. Multivariate regression indicated that low preoperative serum albumin is an independent risk factor for postoperative AKI (p = 0.012, OR = 1.815, CI: 0.675 - 1.162). Conclusion: Preoperative serum albumin level is a valuable predictor of postoperative renal function. Ensuring high normal serum albumin levels before surgery can help minimize the risk of postoperative AKI.

Studies on Interactions of Antibiotics with Serum Albumin by Surface Plasmon Resonance Biosensor

Characterizing how chemical compounds binding to serum albumin is essential in evaluating drug candidates and is the focus of this study. A surface plasmon resonance biosenser developed in this laboratory was used to determine the binding constants of antibiotics with serum albumin. The binding constants of five antibiotics（asithromycin, spectinomycin, gentamycin, metacycline and kanamycin） with serum albumins were obtained.

Interaction Between Gatifloxacin and Bovine Serum Albumin

Aim To study the reaction mechanism between gatifloxacin and bovine serumalbumin (BSA) at different pHs. Methods Fluorescence spectra and UV absorbance spectra were used.Results The binding constants were determined from a double reciprocal Lineweaver-Burk curves atdifferent pHs. The binding distance r under normal physiological condition was obtained according toFoster theory of non-radiative energy transfer. The binding force between gatifloxacin and BSA wasinferred by thermody-namical coordination. Conclusion The interaction between gatifloxacin and BSAseems to be strong and the main binding force is electrostatic force.

(E)-2-Benzylidenecycloalkanones XII.*Kinetic Measurement of Bovine and Human Serum Albumine Interaction with Selected Chalcones and Their Cyclic Chalcone Analogues by UV Spectrophotometry

UV-VIS spectroscopic investigations of interaction of bovine and human serum albumin with selected chalcones (1) and their cyclic chalcone analogues: (E)-2-(4’-X-benzylidene-1-tetralones (3), benzosuberones (4) with dimethylamino and methoxy substituents and (E)-2-(2’,4’-dimethox- ybenzylidene)-1-indanone (2) were performed in polar respiration medium. Absorption maxima of the tested compounds were investigated in the presence of bovine and human serum albumin at the 0, 10, 30 and 60 minute timepoints of the interaction. The absorbance of all studied compounds in the presence of proteins decreased after one hour of the reaction. Molecule 4a showed the strongest and fastest kinet initial interaction with both albumins.

Postoperative decrease of serum albumin predicts shortterm complications in patients undergoing gastric cancer resection

AIM To find an accurate and simple predictor for postoperative short-term complications after gastrectomy. METHODS Two hundred and twenty-three patients undergoing gastric cancer resection between October 1,2015 and September 30,2016 were enrolled in this study. Univariate and multivariate analyses were used toidentify risk factors for complications after gastrectomy. The cutoff values and diagnostic accuracy were examined by receiver operating characteristic curves.RESULTS Sixty-two(27.8%) patients had short-term complications after gastric cancer resection. The postoperative decrease in serum albumin(?ALB) was an independent risk factor for complications(OR = 17.957,95%CI: 6.073-53.095,P < 0.001). The cutoff value was 14.0% and the area under the curve was higher than that of C-reactive protein on postoperative day 3(area under the curve: 0.806 vs 0.709). Patients with ?ALB ≥ 14.0% were more likely to have short-term complications after gastrectomy(46.7% vs 5.0%,P < 0.001),prolonged hospital stay(17.2 ± 10.8 d vs 14.1 ± 4.2 d,P = 0.007) and higher comprehensive complication index(P < 0.001) than those with ?ALB < 14.0%.CONCLUSION Postoperative ?ALB with a cutoff of 14.0% can be used to recognize patients who have high risk of short-term complications following gastric cancer resection.

Spectroscopic analysis on the binding interaction of biologically active pyrimidine derivative with bovine serum albumin

A biologically active antibacterial reagent, 2-amino-6-hydroxy-4-（4-N, N-dimethylaminophenyl）-pyr- imidine-5-carbonitrile （AHDMAPPC）, was synthesized. It was employed to investigate the binding in- teraction with the bovine serum albumin （BSA） in detail using different spectroscopic methods. It ex- hibited antibacterial activity against Escherichia cali and Staphylococcus aureus which are common food poisoning bacteria. The experimental results showed that the fluorescence quenching of model carrier protein BSA by AHDMAPPC was due to static quenching. The site binding constants and number of binding sites （n ≈ 1） were determined at three different temperatures based on fluorescence quenching results. The thermodynamic parameters, enthalpy change （AH）, free energy （AG） and entropy change （AS） for the reaction were calculated to be 15.15 kJ/mol, -36.11 kJ/mol and 51.26J/mol K according to van＇t Hoff equation, respectively. The results indicated that the reaction was an endothermic and spontaneous process, and hydrophobic interactions played a major role in the binding between drug and BSA. The distance between donor and acceptor is 2.79 nm according to Forster＇s theory. The alterations of the BSA secondary structure in the presence of AHDMAPPC were confirmed by UV-visible, synchronous fluorescence, circular dichroism （CD） and three-dimensional fluorescence spectra. All these results in- dicated that AHDMAPPC can bind to BSA and be effectively transported and eliminated in the body. It can be a useful guideline for further drug design.

Significance of functional hepatic resection rate calculated using 3D CT/^(99m)Tc-galactosyl human serum albumin singlephoton emission computed tomography fusion imaging

AIM: To evaluate the usefulness of the functional hepatic resection rate (FHRR) calculated using 3D computed tomography (CT)/99mTc-galactosyl-human serum albumin (GSA) single-photon emission computed tomography (SPECT) fusion imaging for surgical decision making.METHODS: We enrolled 57 patients who underwent bi- or trisectionectomy at our institution between October 2013 and March 2015. Of these, 26 patients presented with hepatocellular carcinoma, 12 with hilar cholangiocarcinoma, six with intrahepatic cholangiocarcinoma, four with liver metastasis, and nine with other diseases. All patients preoperatively underwent three-phase dynamic multidetector CT and 99mTc-GSA scintigraphy. We compared the parenchymal hepatic resection rate (PHRR) with the FHRR, which was defined as the resection volume counts per total liver volume counts on 3D CT/99mTc-GSA SPECT fusion images.RESULTS: In total, 50 patients underwent bisectionectomy and seven underwent trisectionectomy. Biliary reconstruction was performed in 15 patients, including hepatopancreatoduodenectomy in two. FHRR and PHRR were 38.6 ± 19.9 and 44.5 ± 16.0, respectively; FHRR was strongly correlated with PHRR. The regression coefficient for FHRR on PHRR was 1.16 (P < 0.0001). The ratio of FHRR to PHRR for patients with preoperative therapies (transcatheter arterial chemoembolization, radiation, radiofrequency ablation, etc.), large tumors with a volume of > 1000 mL, and/or macroscopic vascular invasion was significantly smaller than that for patients without these factors (0.73 ± 0.19 vs 0.82 ± 0.18, P < 0.05). Postoperative hyperbilirubinemia was observed in six patients. Major morbidities (Clavien-Dindo grade ≥ 3) occurred in 17 patients (29.8%). There was no case of surgery-related death.CONCLUSION: Our results suggest that FHRR is an important deciding factor for major hepatectomy, because FHRR and PHRR may be discrepant owing to insufficient hepatic inflow and congestion in patients with preoperative therapies, macroscopic vascular invasion, and/or a tumor volume of > 1000 mL.

Investigation of the binding behavior of human serum albumin and phosphorothioate oligodeoxynucleotide

Aim To study the binding behavior between human serum albumin （HSA） and phosphorothioate oligodeoxynucleotide （PS- ODN） and the effects of bivalent cations on the interaction. Methods Surface plasma resonance, circular dichroism and fluorescence experiments were conducted. Results （ 1 ） the binding ability was decreased along with the increase of pH; （2） Zn^2＋and Ni^2＋ enhanced the interaction between PS-ODN and HSA; （3） Upon PS-ODN binding, the conformation of HSA was changed with an increase of β - sheet. Conclusion The results provide experimental evidences to the hypothesis that PS-ODN binds with HSA in the positive potential region, and histidine residues located in the region play a crucial rule in the interaction.

Combined fluorescence and electrochemical investigation on the binding interaction between organic acid and human serum albumin

Human serum albumin （HSA） is a plasma protein responsible for the binding and transport of fatty acids and a variety of exogenous chemicals such as drugs and environmental pollutants. Such binding plays a crucial role in determining the ADME （absorption, distribution, metabolism, and excretion） and bioavailability of the pollutants. The binding interaction between HSA and acetic acid （C2）, octanoic acid （C8） and dodecanoic acid （C12） has been investigated by the combination of site-specific fluorescent probe, tryptophan intrinsic fluorescence and tyrosine electrochemistry. For the study of the fatty acid interaction with the two drug-binding sites on HSA, two fluorescent probes, dansylamide and dansyl-L-proline were employed in the displacement measurements. Intrinsic fluorescence of tryptophan in HSA was monitored upon addition of the fatty acids into HSA. Electrocatalyzed response of the tyrosine residues in HSA by a redox mediator was used to investigate the binding interaction. Qualitatively, observations from these three approaches were very similar. HSA did not show any change in the fluorescence and electrochemical experiments after mixing with C2, suggesting there is no significant interaction with the short-chain fatty acid. For C8, the measured signal dropped in a single-exponential mode, indicating an independent and non-cooperative binding. The calculated association constant and binding ratio were 3.1 × 10^6 L/mol and 1 with drug binding Site Ⅰ, 1.1 × 107 L/mol and 1 with Site Ⅱ, and 7.0× 0^4 L/mol and 4 with the tryptophan site, respectively. The measurements with C12 displayed multiple phases of fluorescence change, suggesting cooperativity and allosteric effect of the C12 binding. These results correlate well with those obtained by the established methods, and validate the new approach as a viable tool to study the interactions of environmental pollutants with biological molecules.

Investigation of the interaction between indigotin and two serum albumins by spectroscopic approaches

The binding characteristics of indigotin with human serum albumin （HSA） and bovine serum albumin （BSA） have been investigated by various spectroscopic techniques. Spectroscopic analysis revealed that the quenching mechanism between indigotin and HSA/BSA belonged to the static quenching. The displacement experiments suggested that indigotin primarily bound to tryptophan residues on proteins within site I. The thermodynamic parameters indicated that the binding of indigoti^HSA/BSA mainly depended on the hydrophobic interaction. The binding distance of indigotin to HSA/BSA was evaluated. The results by synchronous fluorescence, three- dimensional fluorescence, Fourier Transform Infrared spectroscopy （FT-IR） and circular dichroism （CD） spectra showed that the conformation of proteins altered in the presence of indigotin.

Immobilization of Bovine Serum Albumin on Poly(ether ether ketone) for Surface Biocompatibility Improvement

UV-induced graft polymerization of acrylic acid（AA） on poly（ether ether ketone）（PEEK） films was carried out to introduce ―COOH for the subsequent immobilization of bovine serum albumin（BSA）.BSA was introduced on PEEK surface based on the condensation reaction between ―NH 2 and ―COOH.The modified surface（PEEK-BSA） was characterized by energy-disperse spectrometry（EDS）,X-ray photoelectron spectroscopy（XPS）,water contact angle measurement and UV spectrum analysis.The contact angle was found to decrease from 104° for the virgin PEEK films to 63° for the BSA-immobilized PEEK films,demonstrating a significant improvement of surface hydrophilicity.Moreover,the appearance of nitrogen on PEEK film confirmed by XPS and EDS indicates the immobilization of BSA on PEEK surface.

Dynamic Behaviors and Morphology Change of Anionic Phospholipid DPPG Monolayer Caused by Bovine Serum Albumin at Air-Water Interface

The interaction between bovine serum albumin （BSA） and the anionic 1.2-dipalmitoyl-snglycero- 3-（phospho-rac-（1-glycerol）） （sodium salt） （DPPG） phospholipid at different subphase pH values was investigated at air-water interface through surface pressure measurements and atomic force microscopy （AFM） observation. By analyzing surface pressure-mean molecular area （π-A） isotherms, the limiting molecular area in the closed packing state-the concentration of BSA （Alim-[BSA]） curves, the compressibility coefficient-surface pressure （CS-1-π） curves and the difference value of mean molecular area-the concentration of BSA （ΔA-[BSA]） curves, we obtained that the mean molecular area of DPPG monolayer became much larger when the concentration of BSA in the subphase increased at pH=3 and 5. But the isotherms had no significant change at different amount of BSA at pH=10. In addition, the amount of BSA molecules adsorbed onto the lipid monolayer reached a threshold value when [BSA]〉5×10-8 mol/L for all pHs. From the surface pressure-time （π-t） data, we obtained that desorption and adsorption processes occurred at pH=3, however, there was only desorption process occurring at pH=5 and 10. These results showed that the interaction mechanism between DPPG and BSA molecules was affected by the pH of subphase. BSA molecules were adsorbed onto the DPPG monolayers mainly through the hydrophobic interaction at pH=3 and 5, and the strength of hydrophobic interaction at pH=3 was stronger than the case of pH=5. At pH=10, a weaker hydrophobic interaction and a stronger electrostatic repulsion existed between DPPG and BSA molecules. AFM images revealed that the pH of subphase and [BSA] could affect the morphology features of the monolayers, which was consistent with these curves. The study provides an important experimental basis and theoretical support to understand the interaction between lipid and BSA at the air-water interface.

Sonocatalytic Damage of Bovine Serum Albumin (BSA) in the Presence of Nanometer Titanium Dioxide (TiO_2) Catalyst

The sonocatalytic damage of bovine serum albumin （BSA） was studied in the presence of nanometer titanium dioxide （TiO2） powders by low frequency （80 kHz） ultrasound. The destruction of secondary structure and change of α-helical structure of BSA were reflected by ultraviolet （UV） and circular dichroism （CD） spectroscopies.

Synthesis of Metal Porphyrins Tailed with Salicylic Acid and their Interaction with Bovine Serum Albumin

A synthetic method of porphyrins tailed with salicylic substituents is described. Reaction of bromoalkoxyphenyl porphyrin 1 with salicylic acid gave porphyrins 2~5. These new compounds were confirmed by 1H NMR, IR, UV-vis, MS and elemental analysis, and observed their interaction with bovine serum albumin (BSA) in fluorescence spectrum.

Antioxidant activity of bovine serum albumin binding amino acid Schiff-bases metal complexes

Glutamic acid-salicylaldehyde Schiff-base metal complexes are bound into bovine serum albumin （BSA）, which afforded BSA binding Schiff-base metal complexes （BSA-SalGluM, M=Cu, Co, Ni, Zn）. The BSA binding metal complexes were characterized by UV-vis spectra and Native PAGE. It showed that the protein structures of BSA kept after coordinating amino acid Schiff-bases metal complexes. The effect of the antioxidant activity was investigated. The results indicate that the antioxidant capacity of BSA increased more than 10 times after binding Schiff-base metal complexes.

Determination of Enantiomeric Compositions of Tryptophan by Chemometric Analysis of the Fluorescence Spectra of Bovine Serum Albumin Receptor-ligand Mixtures

In this work, a novel method was constructed to determine the enantiomeric composition of tryptophan （Trp） by bovine serum albumin （BSA） based on the fluorescence spectra of the receptor-ligand mixtures coupled with partial least squares （PLS-1） analysis. As a result the enantiomeric composition of Trp was accurately determined.

Thermodynamic study on the interaction between anti-tumor drug tegafur and human serum albumin

The changes of thermodynamic properties of the system on interaction between tegafur and human serum albumin （HSA） and the changes of secondary structure units of HSA in the system at 298.15 K have been investigated by the Nano-Watt-Scale isothermal titration calorimetry （ITC）, the Langmuirs binding model and the circular dichroism （CD） spectrometry.

Characterization of Interaction Between Raltitrexed and Bovine Serum Albumin by Optical Spectroscopic Techniques

The interaction of raltitrexed（RTX） with bovine serum albumin（BSA） was investigated by steady state/lifetime fluorescence spectroscopy and circular dichroism（CD） spectroscopy under the simulative physiological conditions.The results of fluorescence titration reveal that RTX could strongly quench the intrinsic fluorescence of BSA via a static quenching procedure.The obtained binding constant K A of RTX with BSA was 478630 and 44259 L/mol at 298 and 310 K,respectively.According to van＇t Hoff equation,the thermodynamic parameters ΔH,ΔG and ΔS were calculated,indicating that hydrophobic forces were the predominant intermolecular forces in stabilizing the complex.The binding process was a spontaneous process,in which Gibbs free energy change was negative.According to F rster＇s non-radioactive energy transfer theory,the distance r between donor（BSA） and acceptor（RTX） was 3.82 nm,suggesting that the energy transfer from BSA to RTX occurred with high probability.Displacement experiment and the number of binding sites calculation confirmed that RTX could bind to the site-I of BSA.Furthermore,the effects of pH and some metal ions on the interaction of RTX with BSA were also investigated.The results of synchronous fluorescence and CD spectra show that the RTX-BSA binding induced conformational changes in BSA.

Investigation on the differences of four flavonoids with similar structure binding to human serum albumin

Flavonoids are structurally diverse and the most ubiquitous groups of polyphenols distributed in the various plants,which possess intensive biological activities.In this study,the interaction mechanisms between four flavonoids containing one glucose unit with similar molecular weight isolated from the Tibetan medicinal herb Pyrethrum tatsienense,namely.apigenin-7-O-β-D-glucoside（1）,luteolin-7-O-β-D-glucoside（2）.quercetin-7-O-β-D-glucoside（3）.quercetin-3-O-β-D-glycoside（4）.and human serum albumin（HSA）,were investigated by fluorescence.UV-vis absorbance,circular dichroism,and molecular modeling.The effects of biological metal ions Mg2＋,Zn2＋,and Cu2＋ on the binding affinity between flavonoids and HSA were further examined.Structure-activity relationships of four flavonoids binding to HSA were discussed in depth and some meaningful conclusions have been drawn by the experiment data and theoretical simulation.In addition,an interesting phenomenon was observed that the microenvironment of the binding site I in HSA has hardly changed in the presence of 4 differentiating from the other three flavonoids on the basis of conformation investigations.

Preparation and evaluation of mixed-mode resins with tryptophan analogues as functional ligands for human serum albumin separation

Five tryptophan analogues with a hydrophobic indole ring and an amino group on each molecule were used as functional ligands of mixed-mode resins for human serum albumin(HSA) purification. Their adsorption performance was evaluated and the effects of p H and salt addition on HSA adsorption were studied. The resins prepared showed typical p H-dependent adsorption and the highest adsorption capacity and affinity were found at pH 5.0for all the resins tested. The saturated adsorption capacity was 138.02 mg·g^(-1)with the tryptaminefunctionalized resin, which significantly decreased at p H below 4.0 due to electrostatic repulsion between ligands and HSA. Moreover, the addition of Na Cl or(NH_4)_2SO_4in media reduced HSA adsorption capacity, although the two salts showed different affecting profiles. The tryptamine-functionalized resin showed the best salt-tolerant performance, and its high adsorption capacity was maintained under high salt concentrations. In addition, the five resins prepared showed good adsorption selectivity for recombinant HSA from Pichia pastoris broth. Molecular docking results between tryptamine and HSA indicated that tryptamine was favorable to bind on Site II(indole-binding site) of HSA.