Combined Tracheal Resection and Coronary Artery Bypass With ECMO Support.

In patients with critical tracheal stenosis, extracorporeal membrane oxygenation support provides an additional level of safety over conventional approaches to secure an airway. This brings operations with exquisite complexity into the realm of routine feasibility. Here we describe a case of combined tracheal resection with 4-vessel coronary artery bypass grafting in a patient with critical tracheal stenosis, occluded coronary arteries, and severely reduced ejection fraction. Postoperatively, the patient made an excellent recovery. This case exemplifies a trend where multidisciplinary cooperation, refinements in surgical techniques, and technological advances allow ever more complex cardiothoracic operations to be performed safely.

Characterization of the interaction between human serum albumin and diazinon via spectroscopic and molecular docking methods.

Human serum albumin (HSA) is a soluble blood protein which binds to small molecules (such as drugs and toxins) and transfers them within the blood circulation. In this research, the interaction of diazinon, as a toxic organophosphate, with HSA was investigated. Various biophysical methods such as fluorescence, ultraviolet-visible (UV-vis), Fourier transform infrared spectroscopy, and molecular docking were utilized to characterize the binding properties of diazinon to HSA under physiological-like condition. The UV-vis spectroscopy showed that the absorption increased and the fluorescence intensity of HSA decreased regularly with regard to the gradual increases of the concentrations of diazinon. Due to the binding constant of ( ka = 3.367 × 10+4 M-1), the α-helix structure for the first day and 35 days of incubation were obtained 66.09-55.4% and 59.99-46.48%, respectively, and their amounts in other secondary structures (ß-sheet, ß-anti, and random (r) coils) were increased. The molecular docking revealed a good binding site in HSA (Trp-214) for diazinon which was related to the considerable alterations in HSA secondary and tertiary structures. There is a close relationship between the secondary structure of protein and its biological activity and after 35 days of incubation, the high toxic concentrations of diazinon can make HSA to be partially unfolded and lose its structure.

Antiamyloidogenic Effects of Ellagic Acid on Human Serum Albumin Fibril Formation Induced by Potassium Sorbate and Glucose.

Oxidative stress has the main role in protein conformational changes and consequent direct involvement in different kind of diseases. Potassium sorbate as a widespread industrial preservative and glucose are two important oxidants that can be involved in oxidative stress. In this study the effect of ellagic acid as a phenolic antioxidant on amyloid fibril formation of human serum albumin upon incubation of potassium sorbate and glucose was studied using thioflavin T assay, surface tension, atomic force microscopy, Amadori product, and carbonyl content assays. The thioflavin T assay and atomic force microscopy micrographs demonstrated the antiamyloidogenic effect of ellagic acid on the human serum albumin fibril formation. This antioxidant also had the repair effect on surface tension of the modified human serum albumin (amyloid intermediates), which was destructed, caused by potassium sorbate and glucose. This mechanism takes place because of potent carbonyl stress suppression effect of ellagic acid, which was strengthening by potassium sorbate in the presence and absence of glucose.

Inhibition of fluorescent advanced glycation end products (AGEs) of human serum albumin upon incubation with 3-ß-hydroxybutyrate.

Advanced glycation end products (AGEs), which are the final products of glycation, have a major role in diabetic complication and neurodegenerative disorders. The 3-ß-hydroxybutyrate (3BHB), a ketone body which is produced by the liver, can be detected in increased concentrations in individuals post fasting and prolonged exercises and in diabetic (type I) patients. In this study, the inhibitory effect of 3BHB on AGEs formation by glucose from the human serum albumin (HSA) was studied at physiological conditions after 35 days of incubation, using physical techniques such as circular dichroism and fluorescence spectroscopy, as well as differential scanning calorimetry (DSC). The fluorescence intensity measurements of glycated HSA by glucose (GHSA) in the presence of 3BHB indicate a decrease in AGEs formation. The DSC deconvolution profile results also confirm the protective role of 3BHB on incubated with glucose by preventing the enthalpy reduction of the HSA tail segment, compared with the deconvolution profile seen for incubated with glucose alone. The concentration of 3BHB used in this study is in accordance with the concentration detected in the body of individuals post fasting and prolonged exercises.

Energetic domains and conformational analysis of human serum albumin upon co-incubation with sodium benzoate and glucose.

Sodium benzoate (SB), a powerful inhibitor of microbial growth, is one of the most commonly used food preservative. Here, we determined the effects of SB on human serum albumin (HSA) structure in the presence or absence of glucose after 35 days of incubation under physiological conditions. The biochemical, biophysical, and molecular approaches including free amine content assay (TNBSA assay), fluorescence, and circular dichroism spectroscopy (CD), differential scanning calorimetry (DSC), and molecular docking and LIGPLOT studies were utilized for structural studies. The TNBSA results indicated that SB has the ability to bind Lys residues in HSA through covalent bonds. The docking and LIGPLOT studies also determined another specific site via hydrophobic interactions. The CD results showed more structural helicity for HSA incubated with SB, while HSA incubated with glucose had the least, and HSA incubated with glucose + SB had medium helicity. Fluorescence spectrophotometry results demonstrated partial unfolding of HSA incubated with SB in the presence or absence of glucose, while maximum partial unfolding was observed in HSA incubated with glucose. These results were confirmed by DSC and its deconvoluted thermograms. The DSC results also showed significant changes in HSA energetic structural domains due to HSA incubation with SB in the presence or absence of glucose. Together, our studies showed the formation of three different intermediates and indicate that biomolecular investigation are effective in providing new insight into safety determinations especially in health-related conditions including diabetes.

Potassium sorbate as an AGE activator for human serum albumin in the presence and absence of glucose.

Advanced glycation end products (AGEs) are the predominant intermediates of glycation process, and mediate oxidative stress and complications of diabetes. Potassium sorbate (PS) as a widespread preservative is an oxidative agent and used in different dairy and drug products, which can readily enter biological matrices. Here we studied the PS interference with glycation of human serum albumin (HSA) in the presence of glucose (Glc) using various techniques. These included TNBSA assay, circular dichroism, fluorescence spectroscopy, differential scanning calorimetry (DSC), Th T assay, and atomic force microscopy. Our results indicated that HSA glycation was accelerated in the presence of PS. Furthermore, PS produced AGEs in the absence of glucose. Secondary and tertiary structural changes were also observed in HSA incubated with glucose in the presence or absence of PS through beta-sheet inducing effects. Th T assay demonstrated the role of PS in HSA fibril formation in the presence or absence of glucose. Atomic force microscopy determined different amyloid fibril formation in HSA incubated with PS in the presence or absence of glucose. Together our results indicated that PS has a stimulatory effect on glycation and fibrillation of HSA in the presence or absence of glucose, and could exacerbate complication of diabetes.

Investigation of thermal reversibility and stability of glycated human serum albumin.

Protein glycation, the process by which carbohydrates attach to proteins upon covalent binding, can alter protein thermal reversibility and stability. Protein stability and reversibility have important role in protein behavior and function. Also they are benefit properties for drug produce and protein industrial applications. In this research the thermal reversibility and stability changes in human serum albumin (HSA) were studied upon incubation with glucose (GHSA) under physiological conditions for 21 and 35 days. The thermal reversibility and stability changes in GHSA were evaluated using circular dichroism (CD), UV-vis spectroscopy, fluorescence spectroscopy and differential scanning calorimetry (DSC). Our results showed that the glycation of HSA increased its thermal reversibility and stability, but decreased its conformational entropy compared to fresh native HSA and untreated HSA. Free lysine content assay (TNBSA test) indicated glucose can bind to protein covalently. These alterations were mainly attributed to the formation of crosslink between the lysine residues of HSA upon incubation with glucose.

Thermodynamics of a molten globule state of human serum albumin by 3-ß-hydroxybutyrate as a ketone body.

The molten globule (MG) state is an intermediate which is considered as the third thermodynamic state of protein molecules. In this work the effect of incubating human serum albumin (HSA) at physiological condition in the presence of 3-ß-hydroxybutyrate for 7, 14, 21 and 35 days were studied by different techniques such as UV/vis, fluorescence and circular dichroism (CD) spectroscopy, differential scanning calorimetry (DSC) and dynamic light scattering (DLS). In this paper, we introduce the MG state for HSA upon 21 days incubation with 3-ß-hydroxybutyrate as a ketone body at physiological condition. The results from the HSA sample incubated for 21 days shows a similar secondary structure by CD, more surface hydrophobicity and a little change on tertiary structure by fluorescence, and a larger size by DLS as compared to the native sample or other incubated samples. These results were also confirmed by calculated parameters and DSC deconvoluted thermograms.

Occlusal recording components for dental implant-supported prostheses.

In this article, three techniques for maxillo-mandibular relationship for Replace-Select implants are described. The use of healing abutments, planning abutments, and Impression copings are presented, and the advantages and disadvantages are discussed.

The impact of off-pump coronary artery bypass surgery on postoperative renal function.

OBJECTIVES: A number of risk factors have been recognised for postoperative renal dysfunction following on-pump coronary artery bypass surgery (CABG). There are, however, few studies that have evaluated the potential reno-protective effects of off-pump CABG in the presence of other confounding risk factors. The aim of this study was to determine if off-pump CABG reduces the risk of renal injury. METHODS: Serum creatinine values (preoperatively and day 1, 2 and 4 postoperatively) and other clinical data were prospectively collected on 1580 consecutive patients who underwent first-time CABG from 2002 to 2005. Creatinine clearance was calculated using the Cockcroft and Gault equation. The effect of on-pump vs. off-pump CABG on renal function was analysed, adjusting for age, gender, diabetes mellitus, left ventricular (LV) function and preoperative creatinine clearance, using multiple regression analysis. RESULTS: One thousand one hundred and forty-five (73%) patients underwent on-pump CABG and 435 (27%) underwent off-pump CABG. The two groups were similar with respect to age, gender and diabetes. Two hundred and seventy-four (17%) patients were females and 274 (17%) patients had diabetes. Multivariate analysis demonstrated significantly lower creatinine clearance postoperatively in patients with diabetes (P<0.001) and advanced age (P<0.001). The on-pump group had significantly lower postoperative creatinine clearance in comparison to the off-pump group (P= 0.01). The effect remained consistent after adjusting for potential risk factors (age, diabetes, gender, LV function and preoperative creatinine clearance) in the multivariate analysis. CONCLUSION: Off-pump surgery is associated with a reduction in postoperative renal injury.