Early Experiences of Serbian Surgeons Using No-Touch Technique for Vein Conduits in CABG Patients: A Follow-Up Study with Multi-Slice CT Angiography.

Background and Objectives: The saphenous vein graft (SVG) remains the most frequently used conduit worldwide, despite its common disadvantage of early graft failure. To solve the problem and reduce the SVG damage, Souza implemented a new technique where a vein is harvested with surrounding fascia and fat tissue (the so-called no-touch technique). Materials and Methods. A prospective study conducted from February 2019 to June 2024 included 23 patients who underwent myocardial revascularization using a no-touch vein, with follow-up control examinations using computed tomographic angiography to detect graft stenosis or occlusion. Results. Of the entire patient group, 17 (73.9%) were male, with a mean age of 67.39 ± 7.71 years. The mean follow-up period was 25 months. There were no major adverse cardiovascular or cerebrovascular events (MACCEs) during hospitalization, although one patient died in the hospital. Another patient died due to malignancy, but no MACCEs occurred during the follow-up period. According to multi-slice CT coronary angiography, the results were impeccable, with an astonishing 100% patency observed in all 20 IMA grafts and 58 no-touch SVGs examined. Conclusions. The excellent patency rate during the early follow-up period confirmed that the no-touch technique is a good option for surgical revascularization.

Kinetic characterization of amino acid activation by aminoacyl-tRNA synthetases using radiolabelled γ-[32P]ATP.

Aminoacyl-tRNA synthetases (AARSs) are fundamental enzymes that pair amino acids and tRNAs for protein synthesis. Aminoacylation occurs in two discrete steps. The amino acid is first activated by ATP, leading to an aminoacyl-adenylate intermediate and pyrophosphate (PPi) formation. In a subsequent step, the aminoacyl moiety is transferred to the tRNA. Kinetic assays were developed to follow each of these steps independently, as well as cumulative two-step aminoacylation. The main advantage of following the activation step over two-step aminoacylation is that most AARSs can activate amino acids in the absence of the tRNA, the production of which is laborious. Hence, the activation step is often tested first in the kinetic analysis, including large screens exploring AARS-targeting inhibitors. Since the 1960s, the activation reaction has been routinely followed by the standard ATP/[32P]PPi exchange assay, which relies on the equilibrium exchange of radiolabel between PPi and ATP using [32P]PPi as a labelled compound. However, this method became much less convenient when [32P]PPi was discontinued in 2022. As a solution, we developed a modified assay that uses easily attainable γ-[32P]ATP as a labelled compound in the equilibrium-based assay. Using this assay, herein named the [32P]ATP/PPi assay, we followed the activation step of several AARSs. The obtained data are in good agreement with the previously published kinetic constants obtained with the standard ATP/[32P]PPi exchange assay.

Calcified amorphous tumor of the posterior mitral annulus.

A 73-year-old male with a history of hypertension, congenital kidney aplasia, status post-myocardial infarction, stroke, and chronic renal insufficiency was admitted to our institute due to coronary artery bypass grafting. Preoperative echocardiogram revealed a 15 × 7 mm mass arising near the posterior mitral annulus. Following the coronary artery bypass grafting, the left atrial cavity was explored using a 30° endoscope. The irregular peduncular calcified tumorous mass was revealed on the annulus of the posterior cusp, near the posteromedial commissure. The mass protruded into the left ventricle. The tumor mass was totally resected, and intraoperative transesophageal echocardiography did not register any residual tumor mass. Supplementary Information: The online version contains supplementary material available at 10.1007/s12055-024-01688-8.

Environmental implications of dental restorative materials on the zebrafish Danio rerio: Are dental chair drainage systems an emerging environmental threat?

This study aimed to evaluate the environmental impact of dental materials: commercial composite Tetric EvoCeram®, glass ionomer Equia Forte® HT Fil, laboratory-prepared composite, alkasite Cention® Forte, amalgam Amalcap® Plus, and samples from dental chair drainage systems (DCDS). Methacrylate monomers were detected in the eluates of experimental and commercials composites, and alkasite. In DCDS samples solely mercury was found at concentrations of 0.08-1.86 µg/L. The experimental composite (48 h incubation) exhibited the highest toxicity on zebrafish Danio rerio (LC50=0.70 g/L), followed by amalgam (LC50=8.27 g/L) < Tetric EvoCeram® (LC50=10.94 g/L) < Equia Forte® HT Fil (LC50=24.84 g/L) < Cention® Forte (LC50=32.22 g/L). Exposure of zebrafish to DCDS samples resulted in decreased larval body length and increased occurrences of edema and blood accumulation. The results obtained highlight the need for additional monitoring and further research on the release of unreacted monomers and mercury from dental materials and their environmental impact.

Measurement of Atmospheric Mercury: Current Limitations and Suggestions for Paths Forward.

Mercury (Hg) researchers have made progress in understanding atmospheric Hg, especially with respect to oxidized Hg (HgII) that can represent 2 to 20% of Hg in the atmosphere. Knowledge developed over the past ∼10 years has pointed to existing challenges with current methods for measuring atmospheric Hg concentrations and the chemical composition of HgII compounds. Because of these challenges, atmospheric Hg experts met to discuss limitations of current methods and paths to overcome them considering ongoing research. Major conclusions included that current methods to measure gaseous oxidized and particulate-bound Hg have limitations, and new methods need to be developed to make these measurements more accurate. Developing analytical methods for measurement of HgII chemistry is challenging. While the ultimate goal is the development of ultrasensitive methods for online detection of HgII directly from ambient air, in the meantime, new surfaces are needed on which HgII can be quantitatively collected and from which it can be reversibly desorbed to determine HgII chemistry. Discussion and identification of current limitations, described here, provide a basis for paths forward. Since the atmosphere is the means by which Hg is globally distributed, accurately calibrated measurements are critical to understanding the Hg biogeochemical cycle.

Exploring mechanisms of mupirocin resistance and hyper-resistance.

Mupirocin is a broad-spectrum antibiotic that acts predominantly against Gram-positive bacteria. It is produced by Pseudomonas fluorescens NCIMB 10586 and has been clinically used to treat primary and secondary skin infections and to eradicate nasal colonisation of methicillin-resistant Staphylococcus aureus strains. Mupirocin inhibits protein synthesis by blocking the active site of isoleucyl-tRNA synthetase (IleRS), which prevents the enzyme from binding isoleucine and ATP for Ile-tRNAIle synthesis. Two types of IleRS are found in bacteria - while IleRS1 is susceptible to mupirocin inhibition, IleRS2 provides resistance to cells. These two types belong to distinct evolutionary clades which likely emerged from an early gene duplication in bacteria. Resistance in IleRS2 is based on the loss of interactions that govern mupirocin binding to IleRS1, such as hydrogen bonding to the carboxylate moiety of mupirocin. IleRS2 enzymes with Ki in the millimolar range have recently been discovered. These hyper-resistant IleRS2 variants surprisingly have a non-canonical version of the catalytic motif, which serves as a signature motif of class I aminoacyl-tRNA synthetases to which IleRS belongs. The non-canonical motif, in which the 1st and 3rd positions are swapped, is key for hyper-resistance and can be accommodated without abolishing enzyme activity in IleRS2 but not in IleRS1. Clinical use of mupirocin led to the emergence of resistance in S. aureus. Low-level resistance arises by mutations of the housekeeping IleRS1, while high-level resistance develops by the acquisition of the resistant IleRS2 on a plasmid. There is no evidence that hyper-resistant variants have been found in clinical isolates.

Traceable Calibration of Atmospheric Oxidized Mercury Measurements.

Most previous measurements of oxidized mercury were collected using a method now known to be biased low. In this study, a dual-channel system with an oxidized mercury detection limit of 6-12 pg m-3 was deployed alongside a permeation tube-based automated calibrator at a mountain top site in Steamboat Springs Colorado, USA, in 2021 and 2022. Permeation tubes containing elemental mercury and mercury halides were characterized via an International System of Units (SI)-traceable gravimetric method and gas chromatography/mass spectrometry before deployment in the calibrator. The dual-channel system recovered 97 ± 4 and 100 ± 8% (±standard deviation) of injected elemental mercury and HgBr2, respectively. Total Hg permeation rates and Hg speciation from the gravimetric method, the chromatography system, the dual-channel system, and an independent SI-traceable measurement method performed at the Jozef Stefan Institute laboratory were all comparable within the respective uncertainties of each method. These are the first measurements of oxidized mercury at low environmental concentrations that have been verified against an SI-traceable calibration system in field conditions while sampling ambient air, and they show that accurate, routinely calibrated oxidized mercury measurements are achievable.

Fatal hyperacute left main thrombosis after aortic root surgery.

Acute aortic root thrombosis is a potentially lethal condition due to the possibility of thrombosis into the ascending aorta branches, resulting in various clinical manifestations. A 29-year-old male patient was admitted to our center with hyperacute left main thrombosis after elective Bentall procedure. Due to massive left ventricular infarction, the patient was supported by extracorporeal membrane oxygenation, but without success to recovery. The patient's blood analyses revealed a high level of the Factor VIII. In conclusion, Factor VIII levels in the blood are elevated by genetic abnormalities, infectious diseases such as severe acute respiratory syndrome-coronavirus 2 infection, and vascular inflammation. This pathological condition may be a reason for hyperacute thrombosis.

Case Report: Giant cholesterol granuloma in the anterior mediastinum.

Cholesterol granuloma is a rare entity, which can develop in many regions of the body, accounting at most 1% of all mediastinal tumors. Etiology of this granuloma is still not clearly understood. The gold standard choice of treatment for cholesterol granuloma is total surgical resection. Symptomatic mediastinum granuloma can be easily diagnosed, but if mass effect is not evident then diagnosis of this tumor is really challenging. We present a rare case of huge cholesterol granuloma in the anterior mediastinum of the patient who underwent on elective coronary artery graft bypass surgery.

Comparison of active measurements, lichen biomonitoring, and passive sampling for atmospheric mercury monitoring.

The number of atmospheric mercury (Hg) monitoring stations is growing globally. However, there are still many regions and locations where Hg monitoring is limited or non-existent. Expansion of the atmospheric Hg monitoring network could be facilitated by the use of cost-effective monitoring methods. As such, biomonitoring and passive monitoring offer a unique alternative to well-established monitoring by active measurements, since they do not require a power supply and require minimal workload to operate. The use of biomonitoring (lichens and mosses) and passive air samplers (PASs) (various designs with synthetic materials) has been reported in the literature, and comparisons with active measurement methods have also been made. However, these studies compared either biomonitoring or PASs (not both) to only one type of active measurement. In our work, we used transplanted (7 sampling sites) and in situ lichens (8 sampling sites) for biomonitoring, two PASs from different producers (3 sampling sites), and two different active measurement types (continuous and discontinuous active measurements, 1 and 8 sampling sites, respectively) to evaluate their effectiveness as monitoring methods. In the 9-month sampling campaign, 3 sampling locations with different characteristics (unpolluted, vicinity of a cement plant, and vicinity of a former Hg mine) were used. The results obtained with lichens and PASs clearly distinguished between sampling locations with different Hg concentrations; using both PASs and lichens together increased the confidence of our observations. The present work shows that biomonitoring and passive sampling can be effectively used to identify areas with elevated atmospheric Hg concentrations. The same can be said for discontinuous active measurements; however, the discrepancy between atmospheric Hg concentrations derived from PASs and discontinuous active measurements should be further investigated in the future.

Surgical treatment of a left ventricular pseudoaneurysm with an extracellular matrix patch.

Left ventricle pseudoaneurysm is a rare and life-threatening complication of myocardial infarction that is formed as a result of left ventricle free wall rupture contained by the overlying pericardium. Urgent surgical repair is crucial, and in most reports, left ventricle was reconstructed with a Dacron or bovine pericardial patch. We present a case of a 66-year-old female with left ventricle pseudoaneurysm which was successfully repaired with an extracellular matrix patch. Supplementary Information: The online version contains supplementary material available at 10.1007/s12055-023-01669-3.

Optimization of a pre-concentration method for the analysis of mercury isotopes in low-concentration foliar samples.

Hg isotope analysis in samples from background regions is constrained by the presence of low Hg concentration and therefore requires a pre-concentration method. Existing Hg pre-concentration methods are constrained by long sample processing time and limited sample loading capacity. Using foliar samples as a test case, an optimized Hg pre-concentration method is presented that involves the microwave-assisted digestion of samples for Hg isotope analysis with the addition of a pre-digestion step. Microwave-digested foliar samples and CRMs were transferred to an impinger, reduced with SnCl2, and collected in a 2.25 mL concentrated inverse aqua regia (3:1 HNO3:HCl, v/v). This resulted in an optimal acid concentration in the solution ideal for analysis on MC-ICP-MS. The time for purging with Hg-free N2 was optimized to 30 min and the efficiency of the pre-concentration method was tested using a combination of approaches. Tests performed on pure reagents and matrix of foliar samples spiked with 197Hg radiotracer showed recoveries averaging 99 ± 1.7% and 100 ± 3.0%, respectively. Mercury at concentrations as low as 1.83 ng g-1 was pre-concentrated by digesting aliquots of foliage samples in individual digestion vessels. Recoveries following their pre-concentration averaged 99 ± 6.0%, whereas recoveries of 95 ± 4.7% and 95 ± 2.5% were achieved for NIST SRM 1575a (pine needle) and reagents spiked with NIST SRM 3133, respectively. Analysis using multicollector-ICP-MS showed low fractionation of δ202Hg during sample pre-concentration with no significant mass-independent fractionation. The proposed method is a relatively simple and robust way to prepare Hg samples for Hg isotopic analysis and is suitable even for complex biological matrices.

Application of traceable calibration for gaseous oxidized mercury in air.

BACKGROUND: The current speciation methods for mercury (Hg) measurements are fraught with considerable uncertainty, from sample collection to calibration. High reactivity of gaseous oxidized Hg (GOM) species and their ultra-trace level presence makes them difficult to sample and calibrate. Given that improper calibration may lead to measurement biases, reliable and metrologically traceable calibration methods are required for accurately quantifying GOM in air. In the present study, we applied the recently developed calibration method based on non-thermal plasma oxidation of elemental Hg, to a commercially available Hg air speciation system for actual environmental measurements of GOM for the first time. RESULTS: Hg species such as HgO, HgCl2, and HgBr2 were produced with trace amounts of reactant gases (oxygen and electrolytically produced chlorine and bromine) and the production was driven by plasma-assisted oxidation. The plasma oxidation efficiency of elemental Hg with oxygen was 98.5 ± 7.5 % (k = 2), while that for chlorine and bromine was 96.8 ± 6.9 % (k = 2) and 97.4 ± 9.6 % (k = 2), respectively. The calibration method was tested against the internal permeation (Hg0) source of the Tekran 2537B Hg analyzer on-field by loading HgO to different KCl-coated denuders using the plasma. GOM concentrations were measured using the Tekran speciation system. With internal calibration, concentrations were up to 9.1 % lower than those in plasma calibration, thereby emphasizing the importance of the calibration strategy. Measurement uncertainty (k = 2) further emphasizes this distinction. Internal calibration measurement uncertainty was 36.8 %, while plasma calibration boasted lower uncertainty at 13.8 %. SIGNIFICANCE: The non-thermal plasma calibration strategy, as a unique and discrete calibration method traceable to the NIST SRM 3133 for ambient air GOM measurements, provide a higher level of confidence in the accuracy of GOM measurements with several advantages over other methods. Calibrations at extreme low concentrations (<100 pg) are possible with this method relevant to ambient air GOM concentrations.

Clinical Impact of Patient-Prosthesis Mismatch After Aortic Valve Replacement With a Mechanical or Biological Prosthesis.

BACKGROUND: Patient-prosthesis mismatch (PPM) may impair functional capacity and survival after aortic valve replacement. This study aimed to investigate the impact of PPM on long-term survival and quality of life after mechanical and biological aortic valve replacement. METHODS: This study included 595 consecutive patients who had undergone isolated aortic valve replacement. Patients were divided into 2 groups according to prosthesis type. The baseline and operative characteristics, survival rates, complications, and quality of life of the groups with and without PPM were compared for up to 6 years. The PPM calculation was performed using the effective orifice area value provided by the manufacturer divided by the patient's body surface area. RESULTS: The moderate to severe PPM rates were 69.8% and 3.7% after biological and mechanical prosthesis implantation, respectively. Mean survival for patients in the biological group who had PPM was statistically significantly shorter (50.2 months [95% CI, 45.2-55.3]) than for patients in the biological group without PPM (60.1 months [95% CI, 55.7-64.4]; P = .04). In the mechanical prosthesis group, there was no difference in mean survival between the subgroup with PPM (66.6 months [95% CI, 58.3-74.9]) and the subgroup without PPM (64.9 months [95% CI, 62.6-67.2]; P = .50). A quality-of-life questionnaire's scores did not differ between the groups. CONCLUSION: Mismatch is common after biological valve implantation and statistically significantly affects long-term survival and quality of life. If the risk of PPM after implantation of a biological prosthesis is suspected, adopting strategies to avoid PPM at the time of surgery is warranted.

Assessing comparability and uncertainty of analytical methods for methylated mercury species in seawater.

BACKGROUND: The relative distribution and importance of monomethylmercury (MMHg) and dimethylmercury (DMHg) in seawater is still under debate. A lack of comparability between measurements at sub-picomolar levels hampered the further understanding of the biogeochemical Hg cycle. To overcome this, we assessed the relative standard measurement uncertainties (Uex,r) for direct measurements of MMHg and DMHg by species-specific isotope dilution ICP-MS and cryo-focusing GC-ICP-MS at femtomolar concentrations. Furthermore, Uex,r was determined for the indirect determination of DMHg (DMHgcalc = MeHg - MMHg) and MeHg (MeHgcalc = MMHg + DMHg) to compare the two methodologies. RESULTS: Expanded Uex,r (confidence interval of 95%) for cryo-focusing GC-ICP-MS was 14.4 (<50 fM) and 14.2% (>50 fM) and for SS-ID GC-ICP-MS 5.6 (<50 fM) and 3.7% (>50 fM). For concentrations above 50 fM, Uex,r for DMHgcalc was always lower than for direct measurements (14.2%). For MeHgcalc, on the other hand, Uex,r was always higher for concentrations above 115 fM (range: 3.7-13.9%) than for direct measurements (3.7%). We evaluated the comparability of directly measured and calculated DMHg and MeHg concentrations based on Hg speciation measurements for two vertical profiles in the Mediterranean Sea. We show that directly measured and indirectly determined DMHg and MeHg concentrations yield comparable results. SIGNIFICANCE: Our results validate the application of the indirect method for the determination of DMHg if a direct measurement method with a low Uex,r such as isotope dilution is used for MMHg and MeHg measurements. The validation of the indirect measurement approach opens new possibilities to generate more precise and accurate DMHg data in the global ocean.

Optimisation of distillation as an isolation method for the determination of low methylmercury concentrations in urine samples.

Methylmercury (MeHg) speciation in urine requires a robust, reproducible and sensitive technique that enables reliable measurements in limited sample volumes. Conventional MeHg extraction by acid digestion allows for processing of only small amounts of urine digest, making accurate MeHg determination in low-concentration samples virtually impossible. Distillation has been proven as an efficient isolation method with very low detection limits for measuring MeHg in water samples; therefore, in this study, it was optimised for urine samples. Combined with aqueous phase ethylation, purging with nitrogen, preconcentration on Tenax trap, isothermal gas chromatography and cold vapour atomic fluorescence detection, distillation achieved high and repeatable urine spike recoveries of 94% ± 7%. Larger measured aliquot volume led to a significantly lower limit of detection (LOD) for distillation compared with acid digestion (1.1 versus 5.5 pg g-1 urine). Thirty-two general population urine samples were analysed using both methods, and the results were compared. Distillation led to better separation of MeHg from inorganic Hg and the matrix. Good correlation was observed between the results obtained by the two methods for samples with MeHg concentrations above 10 pg g-1 urine (slope = 0.9492, R2 = 0.9879). For samples below this MeHg concentration, distillation was superior, enabling the measurement of MeHg in 9 out of 12 urine samples that were below the LOD of acid digestion. Distillation had significantly lower measurement uncertainty, particularly in the low-concentration samples, where the expanded combined standard uncertainty of the acid digestion method reached as high as 43.2% (k = 2), predominantly owing to poor sample repeatability.

Surgical treatment of right ventricle thrombus in a patient with iron-deficiency anaemia.

Right ventricle organized thrombus is a rare pathological condition diagnosed in patients with a risk factor. The most common are right ventricle (RV) failure, autoimmune disease (Behcet disease), hypercoagulable disorder, anaemia, RV pacing leads, pulmonary artery catheters, RV infarction, and ventricular arrhythmogenic cardiomyopathy. The literature describes the impact of iron-deficiency anaemia on thrombosis. We described surgical extirpation of the organized right ventricle outflow tract (RVOT) thrombus in a patient with iron-deficiency anaemia. Supplementary Information: The online version contains supplementary material available at 10.1007/s12055-022-01460-w.

First-in-Human µCAB™ Coronary Revascularization Surgery.

Less invasive coronary artery bypass grafting surgery is underused despite more than 25 years of interest from surgeons and growing patient demands for less pain and rapid full recovery. New approaches may offer surgeons additional options to provide enhanced clinical results through reliable subxiphoid bilateral internal thoracic artery harvesting and the creation of durable anastomoses through very small thoracotomy incisions. This first-in-human case report describes 2 patients who received surgical coronary revascularization using the µCAB™ technology and techniques. The encouraging early results indicate that the µCAB™ approach may offer a new ergonomic, affordable method for coronary revascularization with less surgical trauma.

Surgical Reconstruction of the Anomalous Left Coronary Artery From the Pulmonary Artery.

The anomalous left coronary artery from the pulmonary artery is a rare congenital disease. Early surgical reconstruction is mandatory to prevent adverse cardiac events. Direct coronary button transfer, vein graft interposition, ligation, and coronary artery bypass construction are the most commonly used techniques. This case report presents a modified technique of Dacron graft interposition and reimplantation anomalous left coronary artery from the pulmonary artery on the ascending aorta.