Search Results (6)

Background: Carotid artery stenting (CAS) is a common revascularization approach for carotid artery stenosis. While its impact on the internal carotid artery (ICA) has been extensively studied, the effects on the external carotid artery (ECA)—a key collateral pathway for cerebral perfusion—remain insufficiently explored. This study aimed to assess structural changes in the ECA following CAS and their clinical significance. Methods: A retrospective observational cohort study of 963 patients treated with CAS between 2018 and 2024 was conducted. Demographic data, comorbidities, and procedural characteristics were collected. Pre- and postprocedural ICA and ECA diameters were measured via angiography. Spearman’s correlation, regression modeling, and receiver operating curver (ROC) analysis were used to identify predictors of ECA narrowing and occlusion and their relationship with neurological outcomes. Results: The median ECA diameter decreased post-CAS (from 4.7 mm to 3.8 mm, p < 0.001). ECA overstenting occurred in 96.4% of cases, with 71.7% exhibiting diameter reduction. De novo ECA occlusion occurred in 2.5% of patients and was associated with a higher incidence of stroke, transient ischemic attack, and in-stent restenosis (ISR). Multivariate analysis identified preoperative ECA diameter (p < 0.001), ICA diameter (p = 0.001), and second-generation stents (p = 0.02) as independent predictors of ECA narrowing. ROC analysis confirmed that a preoperative ECA diameter ≤ 3.05 mm strongly predicted occlusion (Area under the curve (AUC) = 0.93, p < 0.001). Conclusions: CAS frequently leads to ECA remodeling, including occlusion, compromising collateral perfusion and contributing to adverse ischemic incidences and ISR. Preprocedural ECA assessment may aid in optimizing patient selection and procedural planning. Full article

Under standard laboratory conditions, Synechococcus elongatus PCC 7942 lacks EcaA^Syn, a periplasmic carbonic anhydrase (CA). In this study, a S. elongatus transformant was created that expressed the homologous EcaA^Cya from Cyanothece sp. ATCC 51142. This additional external CA had no discernible effect on the adaptive responses and physiology of cells exposed to changes similar to those found in S. elongatus natural habitats, such as fluctuating CO₂ and HCO₃⁻ concentrations and ratios, oxidative or light stress, and high CO₂. The transformant had a disadvantage over wild-type cells under certain conditions (Na⁺ depletion, a reduction in CO₂). S. elongatus cells lacked their own EcaA^Syn in all experimental conditions. The results suggest the presence in S. elongatus of mechanisms that limit the appearance of EcaA^Syn in the periplasm. For the first time, we offer data on the expression pattern of CCM-associated genes during S. elongatus adaptation to CO₂ replacement with HCO₃⁻, as well as cell transfer to high CO₂ levels (up to 100%). An increase in CO₂ concentration coincides with the suppression of the NDH-1₄ system, which was previously thought to function constitutively. Full article

Monodisperse Pt nanoparticles supported on carbon (Pt/C) were prepared via an impregnation method. By changing the concentration of the platinum precursor in the initial reagent mixture, the average particle size (d) could be controlled to within a narrow range of less than 2 nm. The specific activity (SA) of these materials, when applied to the oxygen reduction reaction (ORR), increased rapidly with d in the range below 1.8 nm, with a maximum SA at d = 1.3 nm. This value is approximately four times that of a commercial Pt/CB catalyst. The electrochemical active area, ECAA (electrochemical surface area (ECSA)/specific surface area (SSA) × 100), decreased drastically from 100% with decreases in d below 1.3 nm. In this study, we present a correlation between SA and ECAA as a means of determining the appropriate d for polymer electrolyte fuel cells (PEFCs) and propose an optimal size. Full article

Cyanobacteria mostly rely on the active uptake of hydrated CO₂ (i.e., bicarbonate ions) from the surrounding media to fuel their inorganic carbon assimilation. The dehydration of bicarbonate in close vicinity of RuBisCO is achieved through the activity of carboxysomal carbonic anhydrase (CA) enzymes. Simultaneously, many cyanobacterial genomes encode extracellular α- and β-class CAs (EcaA, EcaB) whose exact physiological role remains largely unknown. To date, the CahB1 enzyme of Sodalinema gerasimenkoae (formerly Microcoleus/Coleofasciculus chthonoplastes) remains the sole described active extracellular β-CA in cyanobacteria, but its molecular features strongly suggest it to be a carboxysomal rather than a secreted protein. Upon expression of CahB1 in Synechocystis sp. PCC6803, we found that its expression complemented the loss of endogenous CcaA. Moreover, CahB1 was found to localize to a carboxysome-harboring and CA-active cell fraction. Our data suggest that CahB1 retains all crucial properties of a cellular carboxysomal CA and that the secretion mechanism and/or the machinations of the Sodalinema gerasimenkoae carboxysome are different from those of Synechocystis. Full article

High rates of thrombosis are present in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Deeper insight into the prothrombotic state is essential to provide the best thromboprophylaxis care. Here, we aimed to explore associations among platelet indices, conventional hemostasis parameters, and viscoelastometry data. This pilot study included patients with severe COVID-19 (n = 21) and age-matched controls (n = 21). Each patient received 100 mg aspirin therapy at the time of blood sampling. Total platelet count, high immature platelet fraction (H-IPF), fibrinogen, D-dimer, Activated Partial Thromboplastin Time, von Willebrand factor antigen and von Willebrand factor ristocetin cofactor activity, plasminogen, and alpha2-antiplasmin were measured. To monitor the aspirin therapy, a platelet function test from hirudin anticoagulated whole blood was performed using the ASPI test by Multiplate analyser. High on-aspirin platelet reactivity (n = 8) was defined with an AUC > 40 cut-off value by ASPI tests. In addition, in vitro viscoelastometric tests were carried out using a ClotPro analyser in COVID-associated thromboembolic events (n = 8) (p = 0.071) nor the survival rate (p = 0.854) showed associations with high on-aspirin platelet reactivity status. The platelet count (p = 0.03), all subjects. COVID-19 patients presented with higher levels of inflammatory markers, compared with the controls, along with evidence of hypercoagulability by ClotPro. H-IPF (%) was significantly higher among non-survivors (n = 18) compared to survivors (p = 0.011), and a negative correlation (p = 0.002) was found between H-IPF and plasminogen level in the total population. The platelet count was significantly higher among patients with high on-aspirin platelet reactivity (p = 0.03). Neither the ECA-A10 (p = 0.008), and ECA-MCF (p = 0.016) were significantly higher, while the tPA-CFT (p < 0.001) was significantly lower among patients with high on-aspirin platelet reactivity. However, only fibrinogen proved to be an independent predictor of hypofibrinolysis in severe COVID-19 patients. In conclusion, a faster developing, more solid clot formation was observed in aspirin ‘non-responder’ COVID-19 patients. Therefore, an individually tailored thromboprophylaxis is needed to prevent thrombotic complications, particularly in the hypofibrinolytic cluster. Full article

Antimicrobial resistance is one of today’s major public health challenges. Infections caused by multidrug-resistant bacteria have been responsible for an increasing number of deaths in recent decades. These resistant bacteria are also a concern in the food chain, as bacteria can resist common biocides used in the food industry and reach consumers. As a consequence, the search for alternatives to common antimicrobials by the scientific community has intensified. Substances obtained from nature have shown great potential as new sources of antimicrobial activity. The aim of this study was to evaluate the antimicrobial activity of five bee venoms, also called apitoxins, against two common foodborne pathogens. A total of 50 strains of the Gram-negative pathogen Salmonella enterica and 8 strains of the Gram-positive pathogen Listeria monocytogenes were tested. The results show that the minimum inhibitory concentration (MIC) values were highly influenced by the bacterial genus. The MIC values ranged from 256 to 1024 µg/mL in S. enterica and from 16 to 32 µg/mL in L. monocytogenes. The results of this study demonstrate that apitoxin is a potential alternative agent against common foodborne pathogens, and it can be included in the development of new models to inhibit the growth of pathogenic bacteria in the food chain. Full article